PVP application

The application of PVP in binder

PVP has special adhesion to glass, metal and plastic, paper, fabric surface; Coupled with its characteristics of hydrophilicity, dispersion stability, non-thixotropy, thickening, etc., it is widely used in various binder formulations. There are two types of applications. Class is to PVP as the main component of the adhesive, the other is to use the binding properties of PVP in other products that need binder components, such as coatings, inks, glazing agents, various tablets, granules, sintered materials glaze and so on.

Application in adhesives

As the main component of adhesives, PVP is the most widely used in industry, such as solid glue sticks, pressure sensitive adhesives and rewet adhesives.

Solid glue stick is a new type of office (including school students) glue, because of its easy to use coating, strong initial adhesion, suitable for all kinds of paper, flat and wrinkly after bonding, to overcome the shortcomings of liquid glue, so nearly 30 years to become the world’s popular office supplies. As a solid glue stick binder should have strong bonding ability, especially good initial adhesion; Good coating, thin and uniform coating; Solid shape, no deformation when the coating is stressed, and can adapt to various climatic conditions; Long storage period, non-toxic. It has been proved that PVP is one of the few varieties that can meet all the above requirements among various water-soluble polymers. There are also solid glues on the market with PVA as the main bonding component, but they are generally difficult to overcome the gelling tendency of PVA, short shelf life, and eventually lose the bonding force. Table 56 compares the adhesion strength of several commercially available solid glue products using PVP as raw material.

Table 56 Comparison of adhesion strength of solid glue

sample	Zhehua	TOMBO	UHU	PEPI
Adhesion strength (N/ 25mm)	4.6	3.2	2.9	3.9

The application test proves that the solid glue is suitable for all kinds of writing paper, waxing paper, copy paper, adhesive paper, letterpress printing paper, wrinkle paper, photographic paper, especially for small paper products can operate freely, that is, paste and write; It can also paste fabrics and polystyrene materials such as decorative foam paper. As a result, it has spread rapidly around the world. In the past ten years, China and South Korea have become the main production and export bases of global solid glue. The main raw material PVP K90 purchased by the two countries for the production of solid glue reached about 2,000 tons. For example, China’s Jiangsu Xingda Stationery Group Company purchases 500-700 tons of PVP K90 from home and abroad every year, producing 200-300 million pieces of various types of solid glue, becoming a global solid glue manufacturer.

Another adhesive with NVP polymer as the main bonding component is a pressure sensitive adhesive. Adding PVP to the pressure-sensitive adhesive formula can improve the initial adhesion, strength and hardness of the tape. The copolymer of acrylate and NVP can be used as a protective film of fine materials, with repeated adhesion and stripping properties. Water-soluble polymers including PVP are widely used as adhesive components for medical skin pressure sensitive adhesives. Especially in the skin drug delivery film, this is a new controlled release drug delivery method. The drug film itself contains the drug that can be absorbed through the skin, and the NVP polymer acts as a binder, becoming a gel-like drug matrix that promotes the diffusion of the drug. The glyceryl nitrate used to treat heart attacks can be used to make such a film. For example, the copolymer of NVP and acrylic ester can be used as a carrier of bactericide iodine, which is fixed on the skin through its pressure sensitive adhesion, and becomes a local anti-infection skin drug administration film. Another type of medical pressure sensitive adhesive is to fix the electrode of the medical device on the skin, it is often a pressure sensitive adhesive can be used repeatedly, and can adsorb the electrolyte solution of the hydrogel, PVP can increase the strength of the hydrogel, improve its stability in the electrolyte.

The third binder with NVP polymer as the main component is the rewet adhesive, the so-called rewet adhesive refers to the dry state does not have bonding, and can play a bonding role in the state of water absorption. PVP, especially PVP/VA, is the main component of this class of binders due to its adjustable hygroscopic properties. The adhesive used for hot melt coating and re-wetting is composed of PVP/VA and polyethylene glycol, and its formula is as follows:

Table 57 Rehumidifying binder formulations

	PVP/VA	Castor wax	PEG 4000	PEG 20M	Antioxygen	Saccharin
Weight (parts)	1000	40	25	15	14	1.2

​Selecting the appropriate molecular weight of PVP/VA and the ratio of VP to VA in the molecule can improve the flow temperature of the adhesive, the caking

resistance at 75% relative humidity and the sensitivity to water. From the aspects of thermal stability, caking resistance, adhesion, viscosity, mechanical

properties, hygroscopic speed, hygroscopic viscosity and so on, it can meet the requirements of coating, use and storage.

In other products processing, production as a binder application

Because PVP has excellent adhesion to glass, it is used as a glazing agent for glass fibers to make the surface of glass fibers smoother, reduce wear during stretching, and increase the holding force of fiber bundles. Phenolic resin, saturated polyester resin cellulose derivatives, vinyl acetate/methyl methacrylate resin can be combined with PVP to form glass fiber glazing agent. Some formulations have been applied in some large glass fiber factories in China.

According to the same reason, PVP can also be used for the preparation and processing of many inorganic fibers such as carbon fiber, Al2O3 fiber, magnesium titanate fiber, and increase the bonding force of fiber and resin composite.

When glass, ceramics, quartz, asbestos, mica and other inorganic materials are used to prepare highly flexible and special paper, PVP can often disperse and bond the fibers and improve the strength of the paper.

PVP in fine ceramic processing, high dimensional precision sintered ceramics, controlled magnetic sintered ceramics, flexible ceramics, ceramic surface coating, ceramic, glass printing ink, porcelain glaze, nickel plated steel enamel glaze can be used as slurry, pigment dispersant, binder and has been widely paid attention to and applied. In ceramic processing, PVP can be completely burned during sintering. Therefore, there is no effect on the ceramic itself. PVPK90 also prevents the cracking of ceramic products before sintering. In glazes and inks, PVP’s affinity for pigments and dyes ensures uniform, stable and high adhesion of glazes and inks.

PVP is a forming binder for all types of industrial or domestic tablets and granules, such as cleaning tablets for dentures, painting paint tablets for children, sheet and block cleaning agents for household or industrial use.

PVPK30 and PVPK90 are good binders for the manufacture of gypsum bandages. PVP is dissolved in organic solvent such as methanol to generate methanol-pvp solution, the gypsum is dispersed in it, and then the suspension is applied to the bandage. After drying, the gypsum bandages with good plasticity and uniformity can be obtained, which reduces pulverized powder and increases elasticity and fastness.

PVPKl7 can be used as a binder for photographic paper.

All kinds of binder products have their special requirements and conditions of use, as long as the full understanding of the various properties of PVP and their relationships, you can play the bonding role of PVP in the development of many new products.

The global PVP used to produce binders is about 3,300 tons, accounting for more than 7% of the total consumption of PVP. As for the use in the production of various other products, the demand for PVP, which mainly plays a bonding role, is not included in the above data, and it is difficult to correctly count.
The application of PVP in medicine

Using PVP’s good solubility, solubilization, physiological compatibility, bonding ability and complexation ability, it can be used as binder, excipient, coating agent, release agent, co-solvent, germicidal disinfectant, solubilizer, sustained-release agent, capsule shell, dispersion stabilizer, film forming agent and so on in the field of medicine and health. In some developed countries, such as the United States, Germany, Japan, etc., the application of PVP in the field of medicine and health accounts for about 40% to 55% of the total consumption of PVP. Currently, PVP is in medical medicine
The application of PVP in medicine

Dosage form	Including PVP components	PVP content (% mass)	Main function
troche	PVP-K30	0.5～5	Bonding, solubilizing, forming
particle	PVP-K30	0.5～5	Bonding, solubilizing, forming
coating materials	PVP-K30	0.5～2	Tablet (pill) coating, film forming agent
capsule	PVP-K30	1～2	Granulation aid, protectant, release agent
coprecipitator	PVP-K15 ，K17	——	Increase dissolution rate
injection	PVP-K15 ，K17	5～15	Help dissolve, disperse
oral liquid	PVP-K15 ， K60	——	Disperse and thicken
Take a pill	PVP-K30 ， K90	2～10	Increase potency and reduce irritation
Germicidal disinfectant	PVP-I	——	Sterilization, disinfection, reduce toxicity, irritation
lozenge	PVP-K30 ， K60	0.5～5	Give shape, slow release

​The application of PVP in medicine and health
PVP has good bonding properties and strong dissolution ability. The tablets formed by PVP, after being taken in the digestive tract, dissolve quickly at first, so that the tablets locally expand and disintegrate, release drug fragments, and then accelerate the dissolution and absorption of the drugs, and play a rapid role in the efficacy of the drug. PVP is soluble in water and most organic solvents. For these reasons, PVP has been widely used in pharmaceutical tablets, especially in foreign countries. Examples of common drugs that use PVP for tablet bonding are as follows:
Compound sulfamethoxazole, aspirin, compound aspirin, paracetamol, vitamin C, dipyridamine, dimethyltetracycline, clonidine, benzene sulfonamide, compound analgesic, chewable tablets are illustrated as examples, and their formulations are as follows:

Aluminum hydroxide dry glue 0.4g
Magnesium hydroxide fine powder 0.08g
Powdered sugar 0.02g
Mannitol fine powder 0.2g
10%PVP ethanol (50%) solution 0.03g
Magnesium stearate 0.015g
Peppermint oil 0.0005g
As a drug tablet adhesive PVP is mainly PVP-K30, its dosage depends on the requirements of the mechanical strength of the drug tablet and the nature of the drug itself, generally 0.5% ~ 5%.
Another important use of PVP as drug excipients is co-precipitation agent, some drugs have good efficacy, but its fatal disadvantage is that the solubility in water is very small, resulting in its bioavailability is greatly reduced, the use of some water-soluble substances with these drugs co-precipitation, and then improve the solubility and dissolution rate of drugs, to reduce the dose, improve the efficacy of the effect. As a co-precipitant of insoluble drugs, PVP is being widely used.
The main reason why PVP is used as a drug coprecipitator is that carbonyl O in PVP molecules can be combined with active hydrogen bonds in insoluble drug molecules, which on the one hand makes relatively small drug molecules enter into PVP macromolecules in an amorphous state; on the other hand, hydrogen bonds do not change the water-soluble nature of PVP. As a result, insoluble drug molecules are dispersed in PVP macromolecules through hydrogen bonds, making them easily soluble. The solubility changes of some insoluble drugs after forming coprecipitates with PVP are as follows:
The solubility ratio of drug name to PVP coprecipitate was increased by multiple
Phenytoin 1:52.3
Morpholine 1:538
Reserpine (297-420um) 1:3 15
The increase of solubility of insoluble drugs in human body also correspondingly improves the bioavailability of drugs. For example, the bioavailability of drugs increased by 1.55 times after phenytoin co-precipitation with PVP, and the increase of solubility after co-precipitation of insoluble drugs was related to the molecular weight of PVP and the amount of PVP. In the case of the same amount (quality) of PVP, the increase of drug solubility decreases in the order of PVP-K15>PVPK30>PVPK90, because the solubification of PVP itself changes in the order of PVP-K15>PVPK30>PVPK90. In general, PVP-K15 is used more.
The solubility of insoluble drugs and PVP coprecipitates increases in a complex manner with the amount of PVP. For PVP with a certain molecular weight, each PVP molecule can bind to a certain number of drug molecules, and insoluble drugs often have a certain crystal state. When the amount of PVP is not enough to bind a certain amount of drug and make it in the amorphous dispersion state, the drug is still mainly in the crystalline state, and the solubility changes little. When PVP must reach a certain content, the drug appears as an amorphous dispersion system, and its solubility can be significantly increased to achieve the purpose of rapid dissolution and absorption. For different drugs, the content of amorphous dispersed PVP is different when it reaches the coprecipitate with PVP, such as 70% of cyclohexamine acetate. Drugs that can increase their solubility and bioavailability in humans by PVP co-precipitation include B-carotene, chloramphenicol, dexamethasone, hydroprednisone, streptomycin, tetracycline, and testosterone.
Similarly, the use of hydrogen bond association between PVP molecules and drug molecules can play the opposite effect of solution-increasing and quick-acting, slow release effect, control the degree of association between PVP molecules and drug molecules, and enable drug molecules to be slowly released in the human body after association, delay the dissolution rate, and prolong the effect of drug efficacy. PVP has prolongation effect on penicillin, chloramphenicol, insulin, sodium salicylate, procaine, cortione and other drugs.
In solid drugs, PVP can be used as a binder, solubilizer, disintegrator and delay agent, as well as a drug film coating, drug capsule shell and controlled release film. The drug film coat and capsule shell made of PVP are not easy to break in a dry environment, and the appropriate amount of PVP and other insoluble polymers together make permeable films of different thickness and different pore sizes, which can adjust the rate of drug passing through the film, and then achieve the effect of controlled release.
The application of PVP in liquid drugs
In addition to the many applications of PVP in solid drugs, PVP also plays an important role in injection and ophthalmic medicine. For example, PVP is used in some injections, because of the association between it and drugs, so that one side plays a role in solubility, on the other hand, for some agents that will crystallize or precipitate after too long, PVP can play a role in dispersion and stability. PVP used in ophthalmology can reduce the irritation to the eyes and prolong the action time of ophthalmology.
The application of PVP in medical hygiene, food and beverage hygiene, aquaculture sterilization and disinfection

1. Application of PVP-I in medical and health care:
The application of PVP in sterilization and disinfectant is one of the most successful examples. PVP unique excellent small molecule complexation ability can be generated between the complex povidone iodine (PVP-I), has been collected by the United States Pharmacopoeia, British Pharmacopoeia, Japanese pharmacopoeia, Chinese pharmacopoeia, Martin Pharmacopoeia, and approved in the medical health, human body direct use of disinfection and fungicide. Povidone-iodine suppository, solution, ointment and other dosage forms are collected in Chinese pharmacopoeia. Povidone iodine has become an internationally recognized high efficiency, broad spectrum, non-toxic fungicide, it has a strong bactericidal power and a wide range of bactericidal spectrum.
Mechanism of action: PVP is a hydrophilic polymer, itself has no antibacterial effect, but because of its affinity to the cell membrane, it can directly lead iodine to the bacterial cell surface, which is of great significance to improve the antibacterial activity of iodine. Iodine targets the bacterial cytoplasm and cytoplasmic membrane, killing bacteria instantly within seconds. When the molecules necessary for the survival of organisms such as hydrophobic compounds, peptides, proteins, lipids and cytosine come into contact with PVP-I, they are immediately iodized or iodized to lose their activity and achieve a longer bactericidal effect. PVP-I can kill bacteria, fungi, viruses and protozoa. In vitro experiments on clinically common bacteria, almost no bacteria can not be killed.
Antibacterial spectrum: POvidone iodine can kill a variety of gram-positive and negative bacteria, spores, fungi, Escherichia coli, dysentery bacillus, tetracococcus, Bacillus subtilis, Proteus, Pseudomonas aeruginosa, gonococcus, Pseudomonas maltophilus, citrobacter, Bacillus diphtheriae, Bacillus papiformis, Bacillus anthracis, Candida albicans, flagellates, chlamydia.
Application: It is mainly used for gynecological inflammation, skin inflammation of acne, oral inflammation, oral ulcer, burn, scald, various trauma, surgical operation, skin disinfection before injection and disinfection of medical instruments.
Use concentration and method: POvidone iodine solution can be diluted with water, and the corresponding concentration is prepared according to the disinfection object. The concentration and disinfection method are shown in the attached table: extracted from the Clinical Manual of the National Essential Drugs List.

Object of disinfection	Drug concentration (%)	Usage and dosage
skin degerming	0.2～0.5	Soak, scrub and apply with effective iodine solution containing 2000 ~ 5000mg/L
wound	0.05～0.1	Apply with effective iodine solution containing 500 ~ 1000mg/L
mucosa	0.1～0.5	Apply with 1000 ~ 5000mg/L effective iodine solution
Oral disinfection	0.02～0.05	Gargle with effective iodine solution containing 200 ~ 500mg/L
Vaginal sterilization	0.02～0.05	Apply and rinse with 200 ~ 500mg/L effective iodine solution

2. Application of PVP-I in food and catering hygiene
PVPI’s excellent sterilization ability and physiological compatibility show that it has no irritant and allergic reaction to the human body, so that it also has a wide range of uses in food preservation, disinfection of the catering industry, etc., in some aspects, it shows unique advantages, such as once a week with 0.1%PVP-I solution spray refrigerator, can ensure that there is no odor in the refrigerator for a long time. The usage concentration and usage method of PVP-I in food and catering hygiene industry are shown in the following table:

Object of disinfection	drug concentration (%)	method of application
table-ware disinfection	0.01～0.05	elution
Sanitary ware disinfection	0.01～0.05	spray
Preservation of litchi	0.01	spray
vegetable preservation	0.01	spray
Refrigerator treatment	0.05	spray
Disinfection of food processing machinery	0.005～0.01	elution
drinking water disinfection	1～ 3g /m 3	Place in water and mix well
Swimming pool disinfection	0.01～0.05	Spray or put in water at a concentration of 1-5 g/m3 after discharge
Slaughterhouse disinfection	0.01～0.05	spray
Food and beverage packaging equipment	0.01～0.05	Spray, spray

3. Application of PVP-I in aquaculture industry
The application of PVP-I in aquaculture industry is developed in recent years, and the scope of use is being further expanded. With the further development of aquaculture industry in China, PVP-I as a disinfectant in aquaculture industry has broad prospects. PVP-I is a broad-spectrum disinfectant, which can kill most bacteria, fungi and viruses to varying degrees, and is used for the prevention and treatment of diseases of fish, shellfish, shrimp and crabs. In livestock breeding disinfection and disease treatment also have obvious effects. The concentration and method of PVPI use in the aquaculture industry are shown in the following table (POvidone iodine solution with 1% concentration) :

Object of disinfection	drug concentration (%)	Usage and dosage
Fish, crab, shrimp disease prevention	100～ 200g / mu	The whole pool is sprayed once every 10 days
Fish, crab, shrimp disease prevention	200～ 300g / mu	Sprinkle the whole pool once a day until recovery (additional dose for severe cases)
feed disinfection	1:1000 proportion	Spray or stir evenly
Egg disinfection	use50g /M 3	Water eggs 30-60 seconds (pre-test)
Disinfection of livestock and poultry houses	1:1000 proportion	Dilute and sprinkle evenly

The application of PVP in cosmetics and care products

Due to its excellent surface activity, film forming properties, no irritation to skin and no allergic reaction, PVP has broad prospects for application in the daily chemical industry, especially in cosmetics, skin care products, hair care products and washing products.

The application of PVP in cosmetics:
The research on the application of PVP in cosmetics began in the 1960s, and now it has been widely used in hair care products, skin care products, ornaments and other aspects, among which the most prominent is the application in hair care products. As an excellent surfactant, adding PVP to shampoo can make the foam stable. Because of its physiological compatibility, it will not cause irritation and allergic reactions to the skin, long-term use will not damage the hair, and the hair after washing is smooth and shiny and easy to comb. Hair spray and mousse with PVP have long-lasting styling, good luster, and because PVP has certain water absorption, it makes hair smooth and smooth without appearing dry. PVP for hair care products can be used through the selection and proportion of copolymer monomer types. PVP, which regulates its water absorption and is suitable for dry, neutral and oily hair as a hair conditioner, has unique advantages. The main component of hair is protein, and the molecular structure of PVP is also similar to protein, so it can be used as a supplement for hair nutrients. Long-term use of shampoo and hair care products containing PVP can make hair black and shiny. Reduce split ends,

First illustrate the formula of PVP used in hair care and shampoo products:

Hair spray:

ingredient	Ratio (mass percentage %)
PVP Ethanol (95%) glycerol Purified water Acetylated lanolin essence pigment	4.0 70 2.0 20 2.0 appropriate amount appropriate amount

The role of PVP in other cosmetics is mainly to stabilize the dispersion system such as emulsion and suspension, moisturizing and film-forming role in skin care products, such as PVP in sunscreen, not only moistens, but more importantly, isolates the skin from the sun by forming a film, which plays a role in protecting the skin. In addition, PVP has special uses in other aspects, such as pigment stabilizer, deodorant, deodorant, toothpaste, shaving cream and many other cosmetics. The application ingredients and functions of PVP in cosmetics are listed in the following table:

The application of PVP and its copolymers in cosmetics

application product	Application PVP types	mass fraction（ % ）	main function
hair spray	PVP/PVP quaternary ammonium salt	1～8	finalize the design
mousse	PVP ， PVP/VA polyomer	0.5～5	Setting, moisturizing, forming film
conditioner	PVP ， PVP polyomer， PVP/ styrol copolymer	0.5～3	Hair care, nutrition supplements
shampoo	PVP ， PVP polyomer，	0.1～2.0	Hair care, foam stabilization
hair color	PVP ， PVP polyomer，	—	Dispersants, softeners and pigment stabilizers
perm lotion	PVP PVPQ	0.1～2.0	Disperse and finalize
toilet cream	PVP Copolymer quaternary ammonium salt	0.5～1.0	Wet and lubricate
sun cream	PVP	0.1～1.0	Moisten, lubricate and block sunlight
mask	PVP	0.1～1.0	filmogen
Chilblain cream	PVP/VA	0.2～2.0	Moist, frost proof
shaving cream	PVP Copolymer quaternary ammonium salt	0.1～1.0	Foam stabilizers, softeners and lubricants
Hair removal agents	PVP Copolymer quaternary ammonium salt	0.1～1.0	Wetting agent, lubricant
toothpaste	PVP	0.1～1.0	Tartar removal and stain prevention
deodorant	PVP	0.1～1.0	Spice fixatives, analgesics
Filling adhesive	PVP 、 PVP/VA	1～4	adhesive
mascara	PVP	0.1～1.0	adhesive
nail polish	PVP	0.1～1.0	Binder, crack prevention, film formation
lipstick	PVP	0.1～1.0	moist
late frost	PVPP	1～5	Lubricate and prevent stinging

The application of PVP in washing products

The excellent surface activity of PVP makes it also have a good effect as an ingredient in some washing products. PVPP crosslinked polymer PVPP is used as the ingredient of toothpaste, which can not only remove dirt and antifouling, but also have anti-inflammatory and analgesic effects. The toothpaste formula containing PVPP is as follows:

ingredient	Ratio (mass percentage %)
Superfine calcium carbonate White carbon black Saccharin solution (10% menthol PVPP methylcellulose Calcium hydrogen phosphate glycerin Distilled water	28 2.5 3.5 2.0 3.5 1.2 7 16 36 ． 3

PVP acrylic copolymer used in bath not only has the role of dispersion stabilizer, detergent, and sterilization and disinfection function, especially as a medicated soap, soap ingredients used in the summer has a good effect, PVP both oil and water wet properties make it in the cleaning of clothing, especially in the cleaning of hotels, restaurants with tablecloth cleaning agent has a special effect. For example, Guangzhou Jinyuan Detergent products factory with BASF production of “table cloth net” for washing tablecloth, not only washing time is short, washed tablecloth white and soft, there is a light fragrance smell, and both sterilization and disinfection effect.

In summary, the function of PVP in daily chemical products is mainly manifested in the following aspects:

Dispersion stability function, common skin care products, creams and other cosmetics are mostly lotions and suspensions, to make it can be placed for a long time without precipitation deterioration, so that it is dispersed into a uniform system and has a certain stability time is very important, PVP in cosmetics an important function is dispersion stability function.
Decontamination washing function, PVP and its copolymer due to its specific molecular structure, on the one hand has a lipophilic, can remove clothing, hair and skin oil, sweat stains, etc., on the other hand has a good hydrophilicity, so it is easy to wash clothes and skin stains.
Film forming, moisturizing function, which is the most common function of PVP in cosmetics, widely used in hair care products, skin care products and so on.
Sterilization, disinfection function, mainly used in washing products.

The application of pvp in ink and ink

Writing pen ink and jet printing ink must have good stability and adhesion, so as to ensure that the writing is firm and does not fade, the ink does not precipitate and block the pen, and the printer does not block the nozzle when it runs jet printing for a long time. In addition, it is also required that when spraying or printing is stopped, there is no phenomenon of blocking the nozzle due to the drying and hardening of the ink remaining in the nozzle, which does not hinder repeated spraying, does not affect the direction of injection, and can maintain a smooth re-spraying state. In order to meet these requirements, polyols such as ethylene glycol, diethylene glycol, and glycerol have been used in the past as the wetting agent components of ink and ink, which can control the drying and curing in the nozzle when the injection is stopped to a certain extent. However, if it runs for a long time or stops for a long time (about a week), there is still residue deposition at the nozzle exit, which changes the spray direction or makes the writing line thickness uneven, or even completely blocks the nozzle, so that it can not get satisfactory results.

PVP has good adhesion properties, can be used as a binder, used in ink, ink can make writing and printing handwriting firmly attached to the paper and not easy to fall off and fade. Moreover, PVP has a good dispersion and stability effect on inorganic pigments and organic pigments dispersions, which can be used for ink and ink to obtain a uniform dispersion system, which is not easy to precipitate, does not block pens and various nozzles, and the depth of writing is uniform. And PVP is non-volatile, its role and function lasting. In particular, the printing or printing equipment will not block the nozzle if it stops running for a long time, and it has smooth and repeated spray writing performance. PVP for inks and inks are generally PVP-K12 to PVP-30 products with lower molecular weight.

As a printed matter, such as stamps, printer ribbon used in printing ink, due to the need for long-term use, so the need for light and water resistance excellent pigment as the ink coloring components, required as the main component of the pigment particles can be evenly dispersed, to avoid the dispersion of bad caused by agglutination, printing ink in the dispersion stability and viscosity and other aspects of performance if not good, It will make the painting and handwriting unsatisfactory. In addition, because the long-term use of printing equipment will lead to local temperature rise, the ink is also required to have a certain temperature stability.

Pv-k30 is added to the ink and ink to protect the colloid, thicken and increase viscosity, so that the writing is fluent, does not overflow, does not fade, can also reduce the wear of the ball and extend its service life.

Japan 9-59 554 gives some PVP in ink, ink application formula and production methods. Here are two examples:

Formula one: Carbon ink

Component number

Carbon black 10

NVP/ acrylic copolymer
(Molecular weight 10000) 7.0

Water 33.0

Disperse the above components in a paint oscillator to obtain a carbon black dispersion solution, and then add the following components to the said dispersion solution:

Glycerin 25 (parts)

2-pyrrolidone 25

Water 150

After mixing and stirring, centrifugal separation removes coarse particles and obtains ink for printing.

Formula two: Ink for ballpoint pens

Component number

Carbon Black 8.0

PVP-K30 8.0

Diethylene glycol 20

2-pyrrolidone 5.0

Water 59.8

Preservative 0.2

The above components are mixed and dispersed in the ball mill, and the coarse particles are removed by centrifugal separation to obtain black ink for ballpoint pens.

Id cards and other kinds of documents such special objects are identified by the bar code above, in order to make the documents do not make mistakes, resulting in misunderstandings or serious errors, the production of bar codes must be sophisticated, accurate, and the use of time sometimes more than decades. In order to meet these requirements, the production of the document is achieved through a special magnetic ink, the main components of this ink are magnetic powder, adhesive and organic solvent, as a binder component added to the PVP can increase the adhesion stability of the bar code, and as a bar code substrate synthetic paper, artificial film to form a uniform bar code film. Make the bar code edge neat and firm, not easy to damage. The combination of PVP and polyethylene glycol has better effect. The formula of a magnetic recording ink is as follows:

Component number

Gamma Fe2O3 25

Polyethylene glycol (400) 8

Polyethylene isoamyl alcohol ether 1.8

Polyvinylpyrrolidone (PVP-K30) 2

Dispersant 3

Toluene 20

26

Methyl ethyl ketone 35

The modulation method is to mix each component and process it in the ball mill for 24h, so that it is dispersed evenly, and the magnetic ink with an average particle size below 10μm is obtained after centrifugal separation to remove the coarse particles. A magnetic ink film with a thickness of 15μm was obtained by applying 25g/m2 coating on the surface of fine paper, synthetic paper (polystyrene), synthetic film (polyvinyl chloride), etc. The adhesive stability on the three substrates was very good. The adhesion stability is determined by the following methods: In the marketed viscosity of various magnetic ink samples, the adhesive is removed with a stripping speed of 1cm /s and a stripping Angle of 180°, so that the more adhesive is transferred to the adhesive, indicating that the adhesion stability of the magnetic ink skin film is poor; On the contrary, it indicates that the magnetic ink skin film has good adhesion stability to the corresponding substrate surface.

As the two main components of magnetic ink, magnetic powder and polyethylene are responsible for magnetic recording properties and adhesive functions respectively. In the above formulation, the ratio between γ-Fe2O3 and polyethylene (polyethylene glycol, polyethylene isoamyl alcohol ether, polyethylene pyrrolidone) can be adjusted to obtain magnetic inks suitable for different uses. For example, to increase the adhesion stability of magnetic inks on the substrate, it is necessary to increase the proportion of PVP-K30 or polyethylene glycol, by increasing the proportion of polyethylene glycol in magnetic inks used in general, and by increasing the proportion of PVP in more advanced magnetic inks. Adhesion stability can also be achieved by pressurizing the magnetic ink skin film on the substrate during the production process. The proportion of PVP in magnetic ink is generally between 1% and 5% according to the requirements of use.

The application of PVP in pigments and coatings
one. Application of PVP in the preparation of organic pigments

The surface treatment of pigments is a method of pigmentation, and the organic pigment particles obtained by chemical synthesis have a large surface energy, with a surface ratio of 8 ~ 100m2 /g. If the finished pigment is mechanically crushed, its particle size can only reach 70 ~ 100 μ. It can not be used directly. Therefore, people are interested in particle surface treatment technology with good dispersion performance. Because the surface treatment can change some properties of the pigment. Such as: thermal stability, resistance to strong dissolution, dispersion, color retention, chemical inertness and optical solid properties.

Because PVP has good film forming properties, soluble in water, insoluble in some organic media, and transparent film forming, does not affect the color, and can improve the luster and dispersion of the pigment, it is often used as a surface coating agent of organic azo pigments. The molecular weight Mw of the PVP polymer used for cladding must be greater than 300,000, its thickness is generally 0.001 ~ 1.6μ, the pigment particle size is about 0.1 ~ 10μ, 5 ~ 100 polymers per 100 pigments are required, and the polymer accounts for 20 ~ 50% of the pigment core weight in general. NVP can also be used to copolymerize with a small amount of ethylene unsaturated compounds, especially acrylates, such as acrylic stearate, acrylic hydroxyl substituting alkyl ester and other copolymers as coating agents.

The coated organic pigment has the following advantages:

a) Because the coating is insoluble in organic media, there will be no color diffusion during use.

b) After coating the surface of the pigment with a layer of molecular polymer, the contact between the azo group of the organic pigment and the external medium is cut off, thus preventing the photochemical reduction reaction between the azo group and the external medium triggered by ultraviolet light, which greatly improves the light fastness.

c) Increase the gloss of the paint film to avoid rough cracks.

d) Easy to crush, improve the coloring ability.

We chose 10G fast yellow (filter cake) as raw material and treated it with PVP K90. After mixing, grinding and spray drying, the obtained samples were tested, and the results were shown in Table 46.

Table 46 Test results of 10G fast yellow surface treatment

test number	Pigment to PVP K90 weight ratio	fineness(u)	tinting strength	gloss	light resistance
1	2：1	<2.0	difference	ordinary	6～7grade
2	4：1	<2.0	ordinary	ordinary	6～7grade
3	10：1	<2.0	fine	fine	6～7grade
4	20：1	<2.0	difference	difference	6～7grade

It can be seen from the above test results that when the weight ratio of pigment to PVP K90 is 10:1, the surface treated pigment has excellent coloring power and luster.

Organic pigments covered by PVP can be used in: (1) protective and decorative coatings, such as: lacquer, varnish, paint, etc. (2) aqueous dispersion system. (3) emulsions. (4) printing ink, fabric coloring and plastic coloring.

When the color material is added to the base material of the paint and pigment, because the base material will consume a part of the dispersant and surfactant, this effect is until the equilibrium is established. When there are enough dispersants and surfactants in the paint and pigment, the color is stable and uniform coating can be obtained. When the amount of dispersant and surfactant is not enough, the pigment system composed of color material and TiO2 filler will either flocculate or coalescence, which will reduce the coloring force, cause the viscosity to rise, and the pigment will caking. The usual solution is to add nonionic surfactants, but this creates a more serious foam problem. Therefore, how to improve the dispersion stability of coatings and pigments without reducing their coloring power is one of the important criteria for evaluating dispersants, and it is also a problem that the domestic coatings and pigments industry has been trying to solve. The application of PVP K30 in the preparation of lake blue pigment in Wuhan Fine Art Pigment Factory achieved good results. When 0.20/0 PVP K30 was added to the pigment formula, the coloring power was increased by 205/0 compared with the formula without PVP, as shown in Table 47:

Table 47 Experimental application of PVP K30 to pigments

recipe	Paint lake blue	PVP	red oil	chalk	tinting strength％
1number	1	0.02	3	5	120
2number	1	0	3	5	100

PVP has excellent dispersion effect on carbon black, phthalocyanine pigment, titanium dioxide, etc. For example, the dispersion prepared with carbon black and PVP is not easy to gelate during ball milling and is easy to filter. Fine particles, low viscosity, stable storage; The problem that carbon black color paste is easy to flocculate, precipitate and caking is solved. In the presence of the dispersion, the polyester reaction can be used as the substrate of multi-layer photographic film, and the optical density of the film is more than 12, and there is no transparent needle eye. The pigment dispersion made of phthalocyanine blue or titanium dioxide and cellulose acetobutyrate, PVP pinched and crushed is stable, and is not flocculated or panchromatic when used for the coloring of polyurethane solution, and is suitable for fabric treatment.

The color, color strength and color depth of pigment dispersions prepared from carbon black, blue pigment, PVP and cationic soap are good and stable. The presence of PVP prevents blue pigment from panting due to solvent action. Easy to disperse in paste, ink, resin, suitable for wax-free carbon paper, typing ribbon, printing ink and synthetic resin (such as polyvinyl chloride, polyethylene, polypropylene) coloring.

Luminous pigments such as bismuth oxychloride, ichthyoguanine, colored mica sheet, Berlin blue, etc. are coated with PVP in solvent, and powder pigments can be obtained after drying, with good dispersion and luster, and easy to use.

The wetting effect, dispersion ability and synergistic action of 20 kinds of commercial dispersants on carbon black were investigated. A three-component composite dispersant PCM with PVP as the main component was selected. The color paste prepared by dispersing carbon black with the PCM dispersant was measured by Coulter counter, and the particle size distribution was close to the black paste sample used for filament dyeing by SANDOS, Switzerland, as shown in Table 48. Moreover, the color paste has good storage stability, as shown in sample 1 in Table 49. After half a year of storage, the viscosity of the system only increases slightly. (See Table 49)

Table 48 Particle size distribution of carbon black dispersion

specimen	particle size range
	0.63～2.0μm		2.0～5.04μm		5.05～20.16μm
	volume(％)	particle number(％)	volume(％)	particle number(％)	volume(％)	particle number(％)
SANDOS	79.15	98.25	10-35	1.71	10.50	0.05
Self-made sample	79.15	98_37	25.55	3.60	2.50	0.03

Table 49 Influence of storage time on viscosity of color paste

serial number	The amount of dispersant added			initial value		After half a year		Viscosity increment
	PLD (%)	DM (%)	DC (%)	solid content(%)	viscosity(Pa.s水100)	solid content(%)	viscosity(Pa.s* 100)
1	1.0	1.5	1.5	27.0	2.6	27.6	3.3	27.0%
2	3.0	0.5	0.5	28.0	2.0	28.6	4.4	117.5%

Compared with commercial dispersants, PCM has a very good effect on improving the grinding effect of carbon black, increasing the carbon black content in the color paste, and improving the fluidity of the color paste (see Table 50).

Table 50 Comparison of the effect of PCM and commercial dispersants.

dispersing agent	Carbon black content (%)	Grinding time (hours)	Liquidity class	fineness
PCM	9	8	1	qualified
Factory use	9	8	1	qualified
PCM	16	16	1	qualified
Factory use	16	16	2	qualified
PCM	22	24	2	qualified
Factory use	22	24	3	unmeasured
PCM	27	24	3	unmeasured
Factory use	27	non-abrasive	disqualification	unmeasured

Under the premise of maintaining good fluidity when grinding (that is, level 1), the content of carbon black can be increased by about 78%, which has an obvious effect on increasing the production capacity of the equipment and saving power.

The coloring of chemical fiber stock solution is a new process of spinning by mixing colorant and viscose stock solution evenly. The coloring agent of black viscose filament stock solution using carbon black as pigment is easy to flocculate in viscose stock solution and clog nozzle, resulting in broken head, poor spinnability and poor color light of finished silk. Therefore, although several domestic factories have introduced pre-spinning injection equipment, no one can normally produce black colored silk. It has been proved that the carbon black paste made with ‘PCM’ has good dispersibility, low viscosity and stable storage. The dyeability evaluation test of self-made black color paste was carried out in Baoding Chemical fiber factory. The experimental results showed that the front breakage rate of No. 1 and No. 3 samples containing PVP was significantly lower than that of No. 2 samples without PCM, indicating that PVP had a significant effect on the dispersion of carbon black paste, which was basically close to the spinnability level of Swiss Ciba one-base black paste samples. The luster of the finished silk spun by the color paste containing PVP is greatly improved.

2. The application of PVP in waterborne coatings

In water-based coatings such as emulsion coatings and water-soluble resin coatings containing pigments, the coloring effect is reduced due to the poor dispersion of pigments and the condensation and precipitation during storage, and the undesirable phenomena such as floating color and poor luster appear. For this purpose, a suitable dispersant is needed, however, the general low molecular weight surfactants have poor film formation, unstable rheological properties, and great limitations on the binder used. The polymer dispersant has the advantages of high stability, good rheology, good adsorption on pigment surface, improving coloring power and improving luster, etc., which is the development direction of pigment dispersant.

Japan believes that the use of (1) synthetic or natural saturated fatty acid modified acrylate, (2)NVP, (3)α, β-vinyl unsaturated acid, etc., according to a certain proportion of the synthetic dispersant, can make the pigment good dispersion, but also has good film formation, can improve the performance of water-based coatings, suitable for many organic, inorganic pigments and water-based resins.

In the emulsion coatings with styrene and methacrylate as the main body, due to the low viscosity of emulsion, water-soluble polymer addition method, solvent addition method, alkaline thickening method, evaporation and concentration method were used to thicken. The disadvantage is that the viscosity of the latex is difficult to control, changes with time, and the water resistance of the coating is reduced. If polyvinyl alcohol is used as a thickener, it has a strong tendency to coagulate or gelate, and can not obtain stable high-viscosity latex. In the presence of PVP, the low viscosity synthetic resin emulsion with a viscosity below 1000cp can be changed into a stable high viscosity synthetic resin emulsion with a viscosity above 10000cp by evaporation and concentration. The coating prepared by the emulsion with this method has the advantages of no hanging, good water resistance, hard skin film, no discoloration, no shedding and dirt resistance.

When the content of the substrate pigment is high, the thixotropy is obvious, the fluidity is poor, and the film is easy to protruding. However, if PVP and other leveling agents are added to the styrene acrylic emulsion, a coating with high pigment content (non-volatile content of more than 70%), high viscosity, good leveling and smooth film can be obtained, and a smooth coating can be obtained by pressing, and the paint amount is less, the luster is good, and the pollution resistance.

In recent years, the use of microencapsulation technology can further improve the dispersion stability of pigments, improve the covering ability and anti-fouling properties of coatings. United Carbon Company proposed the polymerization of vinylpyrrolidone in the suspension system composed of pigment and water, the solid phase particles were dispersed at the same time, and then vinyl acetate monomer and butyl acrylate were introduced to continue to polymerize on the surface of solid particles to form a film, and finally a stable coating dispersion was obtained. The coating obtained with the coating can prevent food contamination.

3. The application of PVP in special coatings

The surface of the printing paper is generally coated with an overlay. A transparent coating containing PVP allows the printing ink to dry quickly on it. The transparent layer has good ink absorbency, insoluble in water, and has good coagulability and diffusivity. And high-speed imaging due to transparency. Especially suitable for multi-color ink printing.

PVP can also be used in the preparation of conductive coatings. A conductive plastic film made to prevent electrostatic hazards is made by thinly coating the plastic film with a conductive transparent coating containing carbon black and a binder, and then coating it with a transparent protective layer. PVP is used here as a carbon black binder. In the past, water-soluble polyvinyl acetate alkalinates were used as binders, but satisfactory diluents could not be obtained, and there were problems such as drying difficulty and poor leveling. If PVP is used instead, a conductive coating with good conductivity and transparency, uniform coating and easy drying can be obtained. Generally, the molecular weight of PVP is 10000, because low molecular weight PVP is also beneficial to carbon black dispersion. In addition, if the coating content needs to be increased, it can be adjusted by adding polymer PVP.

Application of PVP in polymer industry

Polyvinylpyrrolidone is a kind of polymer surfactant because of its molecular structure with hydrophilic groups and oleophilic groups, as well as good adsorption ability to solid particles surface, so it can change the interface or solution state. In different dispersion systems, PVP with different molecular weight can be used as dispersant, stabilizer, emulsifier, thickener, leveling agent, particle size regulator, anti-reprecipitating agent, coagulant, co-solvent, and washing aid. In coatings, pigments, inks, polymer synthesis and processing, detergents, binders, photosensitive materials, drugs, cosmetics, food and other industrial processes or industrial products, PVP has been widely used for its excellent solubility, film formation, physiological inertia, complexing ability and other comprehensive characteristics.

The application of PVP in dispersion polymerization

PVP can be used as thickener, stabilizer and particle size regulator in polymer emulsion polymerization and suspension polymerization. Generally speaking, PVP with larger molecular weight (K>60) acts as a protective agent to prevent suspension precipitation, prevent the aggregation of larger particle size particles in the emulsion and dispersion solution, and make it stable. Low molecular PVP is more suitable for dispersing agents, especially for dispersing low density substances. Of course, the molecular weight and its distribution must be compatible with the particle size and distribution of the dispersion.

PVP and NVP copolymers can be used in styrene homopolymerization and copolymerization, suspension polymerization of vinyl chloride, methacrylate and polyurethane, emulsion polymerization of acrylic ester and vinyl carboxylate, which can play an excellent role in dispersion stability, particle size control, viscosity adjustment and resin performance improvement.

In the suspension polymerization of granular polyurethane urea, some of the previous technologies use organic solvents, and some can only get water dispersion or get large chunks after solidification, which brings inconvenience to the use and transportation, increases the processing cost, and affects the product quality. Therefore, it is urgent to develop a one-step synthesis technology of polyurethane urea with small particle size. In this one-step polymerization technique, the obtained solid phase polymer is not easily emulsified and can be separated by conventional separation methods. The particle size of polymer can be controlled by controlling the stirring speed and selecting dispersant. PVP is particularly suitable as a suspension stabilizer for this one-step polymerization. Its addition amount is about 2.5 ~ 5.0% of the water phase, and its molecular weight takes K value of 60. When the reaction is over, the toluene – water – is steamed

Azeotrope can be cooled, filtered, washed and dried to obtain powder urethane. When the amount of PVP K60 was 2.5%, the polymer particle size was 800 μ-1000 μ. The isocyanate content of the polymer is less than 0.5%, basically non-porous, and can be used in coatings, binkers, flocculants, laminate composites, to make films, with a thickness of 100 μ. As a coating, with a thickness of 10 μ.

It is well known that the type and concentration of suspension stabilizer has a decisive influence on the shape, size and morphology of the polymer. In some suspension polymerization, only the stability of PVP K90 and PVA can produce uniform particle size beads with porous shells. This proves that PVP has a good stabilizing effect.

When methyl methacrylate, vinyl acetate, polyethylene, chloroprene and other monomers are polymerized, the resulting products often have high elasticity only at the temperature of 120 ~ 150 ° C, and contain impurities such as unreacted initiators. However, when PVP K30 or PVP K15 was introduced as emulsifier, the high elastic temperature range of methyl methacrylate polymer was 120 ~ 280 ℃. When emulsion polymerization is performed at 50 ℃, the polymerization monomer can be completely transformed in 20 minutes to 100 minutes, and the resulting polymer flow temperature is 270 ~ 280 ℃.

In the suspension polymerization of vinyl chloride, if PVP is used as the dispersion stabilizer, the thermal stability of the polymer is good. When NVP copolymer is used as the stabilizer, the dispersion of PVC can be improved. By using a mixed suspension agent composed of NVP and vinyl acetate copolymer as one of the components, the thermal stability, oil absorption rate, particle size, fish eye and residual bill of the obtained polymer have been greatly improved. The results are shown in Table 43:

Table 43 Comparison of properties of PVC polymers with different suspension agents

suspending agent(1)	bulk weight g/1	oil absorption%	Hot mixing minutes · seconds	size distribution		Fisheye number Per cm2	Residual bill In 2 minutes ppm
				>250μ	<63μ
PVP/VA(2) Sorbitan ester not have PVP/VA PVP/IOA(3)	440 465 475 455	37 32 18 18	3’45” 4’30” 5’30” 5’30”	O 3 18 16	0 1 0 0	8 24 200 300	<1 6 78 24

(1) Mixed suspension, the remaining components are acetylated PVA or methylhydroxypropyl cellulose.

(2) The ratio of NVP to vinyl acetate was 3/7.

(3) NVP copolymer with isooctyl acrylate, NVP/IOA is 9/1.

In styrene butadiene emulsion polymerization, PVP and surfactant can play a co-stabilizing role, and finally get a low viscosity, high solid content of latex, and small particle size, good water resistance, drying speed, no foaming, solid content up to 60 ~ 65%. The product can be used in coating, carpet glue and many other places where polymer emulsions are used, and the amount of PVP is 0.5 ~ 1.0%. The carpet lamination coating was prepared with latex obtained with different matching surfactants and the molecular weight was PVP K15. The results were shown in Table 44.

Table 44 Comparison of adhesive properties of styrene butadiene latex with different surfactants

recipe	A	B	C	D	E	F	G
Surfactant for latex 1% SDS% Particle size Degree of cohesion Drying time (minutes)	PVP K15 1.0 little not have 10.5	K30 1.0   have 10.6	K60 1.0 centre have 10.7	not have 2.0 little not have	not have 1.0 big repeat 12.11	PVA 1.0   have	HEC 1.0   have

PVP K30, imported from GAF of the United States, has been used as a protective adhesive and thickener in the polymerization of vinegar-propylene emulsion in Beijing Dongfang Chemical Factory. The product quality is excellent and stable. The polymerization test of PVP K30 from Zhejiang Institute of Chemical Industry was carried out and compared with the imported PVP K30 under the same conditions. The results showed that the performance of the emulsion using domestic PVP K30 was basically the same as that using imported PVP. The test was carried out in a 2M3 reactor, and the quality of the product was compared with that of imported PVP as follows:

Table 45 Results of product performance test using domestic PVP

project	appearance	solid content %	PH	viscosity mPas	Residual bill%	grain size μ	film-forming property	Ca2+ stability
index	milky white	60±1	3.5～5.5	600～1200	<0.05	0.5～0.7	Uniform transparency	stabilization
900501	milky white	59.31	4.54	670	0.03	0.45	Uniform transparency	stabilization
900502	milky white	59.84	4.64	760	0.04	0.56	Uniform transparency	stabilization
900802	milky white	59.40	4.90	910		0.53	Uniform transparency	stabilization

The test results showed that the quality of domestic PVP K30 emulsion reached the standard completely, and the emulsion processing application confirmed that the coating’s water resistance, freeze-thaw resistance and other aspects of stability were improved compared with imported products.

The application of PVP in brewing and beverage industry
PVP and insoluble PVP can be used as a clarifying agent and stabilizer for beer, fruit wine and fruit juice in the brewing and beverage industry, and it has been legally permitted to be used in production in 38 countries in the world. A low-alcohol wine made from plant ingredients such as barley, rice or corn, and hops, rich in a variety of proteins and polyphenols. In addition to the turbidity caused by the rancid deterioration caused by biological factors, the colloidal particles will produce flocculation precipitation under certain conditions, resulting in the turbidity of the wine body. For example, beer will produce cold turbidity when it is refrigerated, and the turbidity will disappear when the temperature rises to more than 20 ° C, and if it does not disappear at 20 ° C, it is called turbidity. No matter what kind of turbidity is produced, it will affect the stability of the wine and make the quality worse. The turbidity caused by abiotic factors is a common problem in making wine from plant raw materials such as grains and fruits. It has great influence on the color, flavor, foam and shelf life of the wine. Among them, the abiotic stability of beer is the most concerned by the scientific and industrial circles.

The abiotic turbidity of beer and other alcoholic drinks is related to the variety and content of polyphenols it contains. Polyphenols can be roughly divided into three categories: anthocyanins, catechins, flavonoid polyhydroxyl derivatives and phenolic acid derivatives. These compounds are easily oxidized and polymerized to dimer in air, and can be further oxidized to quinone. The dimer produced by catechuic acid can also be further polymerized to produce polymers. Polyphenols form hydrogen bond complexation through the amide bond between phenol hydroxyl group and protein, and the complex precipitates to produce turbidity. The more protein and polyphenol content, the more likely to cause abiotic turbidity of beer. Studies have shown that unpolymerized polyphenols have little effect on the formation of turbidity. Once they have tannic properties after forming dimers or polymers, they tend to increase their complexation with proteins, first showing cold turbidity, and then further becoming sexual turbidity. Therefore, reducing the content of anthocyanins in beer can improve the color, flavor and abiotic stability of beer.
The application of PVP in textile printing and dyeing industry

PVP has been widely used in textile printing and dyeing industry because of its complexing ability and colloid protection.

Application in textile industry

PVP has a strong affinity with general organic dyes, especially with direct, reduction, vulcanization, dispersion and other dyes. This is mainly caused by the binding force between the lactam structure in PVP molecules and the organic functional groups in dyes, such as hydroxyl, amino, carboxyl groups. This force often exceeds the binding force of dye and fiber under certain conditions, so PVP is called “liquid fiber”. This property of PVP can improve the dyeability of many hydrophobic synthetic fibers. PVP(or its copolymer) is introduced into synthetic fibers by grafting copolymerization, surface grafting, mixing with synthetic resin, wet spinning fiber impregnation, coating, etc., so that synthetic fibers can be dyed uniformly and the dyeing depth can be improved. For example, 5%-10% of PVPK30 is added to the spinning stock solution of polyacrylonitrile or its copolymer for mixing, and the dyeing depth of the fiber for the following dyes is increased as follows:

Celliton Fast Yellow GGLL 100%

Celliton Fast Pink RF 82%

Celltion Fast Blue FFRS 47%

For polypropylene fibers that are difficult to dye, such as the copolymer of 7.5% ~ 10% ethylene-vinylpyrrolidone added to the resin (containing 75% ~ 90% ethylene) for spinning, the fiber dyeing depth can be increased by nearly ten times for acid dyes and 3 ~ 7 times for dispersive dyes. Viscose, polyamide, polyvinyl chloride and other fibers have the same dyeing effect.

In addition to improving the dyeability of synthetic fibers, PVP can also improve other properties of synthetic fibers. For example, the graft copolymer of PVP and nylon 66 can not only be dyed dark with acidic direct reduction dyes, but also improve its hygroscopic property, wrinkle resistance, shape, easy washable property, strength and sun resistance after bleaching. Another example is the use of 10% PVP mixed viscose fiber, its moisture absorption from 3ml/g, increased to 5 ~ 6ml/g. For example, the copolymer fiber of acrylonitrile and vinyl chloride will produce permeability and loss of light when it meets water or water steam under heat conditions. After adding 3 ~ 5% PVP, the fiber does not have the above phenomenon.

Application in printing and dyeing industry

Because PVP has a strong ability to combine with many dyes, it was used as a stripping agent, bleach, and subtractive agent in the 1950s. More recently, it has been proposed to incorporate maleic anhydride-styrene copolymers into PVP bleach formulations to reduce the cost of bleaching fabrics.

In some special occasions, PVP can be used as levelling agent. For example, 1% PVP can make nylon 6, nylon 66 blended fiber fabrics dyed with acid dyes or metal complex dyes to get color difference. 2% PVP(wt) can be used as a leveller for modified polyester fiber dyeing with cationic dyes. The dyed fabric not only has uniform color, but also increases the sun fastness from the original two levels to eight levels, and its antistatic property is also increased (the specific impedance is increased from 1.1×106Ω-cm to 1012Ω-cm). When PVP is used as levelling agent, it can be dyed by one-bath method with uniform color and good color fastness.

The ability of PVP to combine with different dyes is different. Using this property, PVP can be used as anti-dye agent in anti-dye printing of animal fiber, polyamide fiber and polypropylene fiber. Adding 3% PVP to the coloring paste can effectively prevent the ground color dyeing (ground color with metal complex dye or disperse dye), and get a bright pattern and clear outline of the printed fabric.

When the ratio of PVP to the metal complex dye is increased (at least 1:2), the marking color – temporary printing dye can be made. After dyeing wool, acrylic, nylon, polyester, viscose fibers with this dye, its color is easy to wash off with water, still leaving white fibers.

Most water-soluble polymer compounds have colloid protection and solubilization, but PVP is particularly excellent in this respect, so it can be used as a structural levelling agent for high temperature dyeing of disperse dyes to improve the stability and dyeing speed of disperse dyes. This disperse dye is prepared by spray drying of PVP and dye together in solvent. The dye and PVP are in solid solution state with particle size < 0.1μ.

Dispersible dyes in solvent dyeing because the dyes are insoluble in solvents, usually need to use a lot of surfactants, solvent recovery is large, dyeing rate, color fastness is low. If PVP(often its derivatives) is used as a dispersant for dye processing, a stable storage disperse dye can be obtained. The solvent dyeing of polyester fiber with this dye can obtain uniform dyed fabrics that are resistant to moisture, wear, heat and light. 1% ~ 3% PVP can prevent thixotropy and degradation of VAT dyes and disperse dyes during storage, and still maintain the fluidity of dye paste after a few weeks. Adding < 3% PVP(measured by solid content) to the hydroxymethyl anti-wrinkle and anti-shrinkage finishing agent can improve the storage stability of such additives. After several months of storage, the remade aqueous solution will not precipitate after a week.

The transfer dyeing and finishing process has the advantages of fast speed, less amount of auxiliaries and good processing quality. The key is to need a kind of fiber affinity, good solvent compatibility, good film formation, suitable for coating paste; It is also required to have dispersion, stability and a certain cohesiveness for dyes and finishing AIDS; Easy preparation; Soluble in water, easy to wash off after dyeing and finishing. Because PVP meets the above requirements, PVP has a wide range of adaptability and good results in transfer dyeing, bleaching, cleaning, finishing (anti-wrinkle, waterproof, antistatic, Antisnag, etc.).

Generally, in fabric finishing, cationic finishing AIDS and anionic fluorescent whitening agents are incompatible and cannot be processed in the same bath. If 0.1 ~ 2% PVP is added to the bath, the fabric can be processed and finished with softener or antistatic agent, resin finishing agent and fluorescent whitening agent at the same time in one bath. The whiteness, fluorescence, softness, electrostatic charge and strength of the treated fabric all reach or exceed the performance index.

The application of PVP in cleaning agent and detergent
In the textile printing and dyeing industry, the fabric must be washed (or soap washed) after printing, the purpose is to wash off the unfixed dye and the finished slurry and other printing and dyeing additives on the fabric, in order to improve the color fastness, restore the hand feel, and get the printed fabric with bright and clear patterns. For this reason, a certain cleaning agent should be used in the process of washing and desizing. The general requirements for cleaning agents are that they can effectively wash away unfixed dyes and slurries without excessive stripping; No damage to the fabric; Use less, save water. However, with the unfixed dye gradually transferred from the fabric to the bath during the cleaning process, a dyeing bath condition with a certain dye concentration, a certain temperature and a certain time is formed, so that the dye transfers between different dyed parts of the cleaned fabric through the clean bath, especially the color transfer from the colored part to the colorless part, that is, the so-called white stain. Obviously, when the dye fastness is low (such as silk with direct dye, acid dye printing), the dye concentration in the residue is high; When plant starch is used as a slurry, it is difficult to desizing, so it is necessary to use a higher cleaning temperature and a longer cleaning time. In these cases, the color phenomenon is more serious, and the quality of the product is seriously decreased. On the contrary, such as reducing the temperature, increasing the bath ratio (relatively reducing the dye concentration in the residual liquid), increasing the desizing additives (thereby reducing the desizing time) and other measures to reduce the color transformation, staining phenomenon may cause floating color and the slurry is not drained, low color fastness, hard feel, increased water and energy consumption, decreased productivity and other shortcomings.

In daily life, when we wash fabrics, the same phenomenon exists. For example, when we use ordinary washing powder in the same bath to wash fabrics of different colors, especially colored fabrics and white fabrics, color transfer or white stain will occur. For easily faded fabrics, such as silk fabrics, in order to avoid white stains, we often have to wash colored fabrics and white fabrics in separate baths without or with less detergent. Therefore, developing and producing printing and dyeing detergents and household detergents that can prevent white soil contamination is the key to solve the above cleaning problems. Anti-white soil pollution agent must have a certain cleaning ability and anti-dyeing ability at the same time. This cleaning capacity should be adapted to the wet fastness of the dye; This resistance must be sufficient to inhibit the rate of contamination that occurs under such cleaning conditions.

Among all kinds of surfactants, it has long been found that the non-ionic surfactant of polyoxyethylene ether has excellent dispersion emulsification and cleaning properties, and also has a certain affinity for dyes. It can form a surfactant containing micellar structure with dyes – dye aggregates, which greatly increases the solubility of water to dyes. At the same time, because the particles of this aggregate are larger, the diffusion rate in the solution is slowed down, so as to achieve the purpose of slow dyeing and even anti-dyeing.

As mentioned above, PVP has excellent solubility (both soluble in water and soluble in alcohol, halogen and other organic solvents) and colloidal protection ability, and has strong complexing ability with dyes, inspiring people to apply PVP to the development of detergents and cleaning agents with anti-white ground pollution performance.

The first to use PVP for washing is the synthetic detergent industry. The well-known disadvantage of soap is that it is not resistant to hard water; The disadvantage of sodium alkyl benzene sulfonate is its poor ability to prevent the redeposition of dirt. For this purpose, carboxymethyl cellulose is usually added to laundry detergent. However, when the concentration of Ca++ in water is high, its ability to prevent dirt redeposition decreases. The experimental results showed that PVP with molecular weight of 15000-40000 had good anti-redeposition ability. When 0.1% carbon black is used as dirt and the hardness of water is 300ppm CaC03, under the same washing conditions, the reflectance of the white fabric tested by adding 0.01%PVP is 51(the reflectance of the original is 70%), and the reflectance obtained by adding 0.01% CMC is 18%. Therefore, in many detergents, PVP is used as a formula component.

In 1973, the Procter Gamble Company in the United States published a general. PVP is used as detergents to prevent color conversion. The results show that when < 3% PVP is added to the common detergent formula, the white soil stain degree of cotton ester blended (direct blue dye), wool (chromium dye), polyester (disperse and direct blue dye), copper ammonia acetate (disperse and direct dye) fiber fabric can be greatly reduced. In the test, the detergent concentration is 0.4%, of which the various types of surfactants are 5-15%, PVP is 0,1.5, 3% three grades. The whiteness of undyed samples is determined by visual inspection and color difference meter after washing. In the visual method, the standard grades of whiteness are -3, -2, -1, 0, 1, 2, 3. 0 means the whiteness of the sample is equal to that of the reference white sample, 1 means there is a slight difference, 2 means there is a moderate difference, and 3 means there is a large difference. Positive or negative values respectively indicate better or worse whiteness than the reference white sample.

The application of S-2, a cleaning agent for printing and dyeing industry containing PVP jointly developed by Zhejiang Institute of Chemical Industry and Zhejiang Institute of Silk Science, in silk printing process has been successful, and has been popularized in many domestic manufacturers. The German BASF company has been promoting the Sokolan series of anti-color agents for cleaning with PVP K17, PVP K30 and PVP/VA copolymers as the main components in the market for decades. Success has been achieved in both industrial and civilian areas.

From the above situation, we can know that the cleaning agent containing PVP can not only prevent the transfer of color or white dirt in the cleaning process, but also improve the cleaning ability, both of which are unified in the affinity of PVP and dyes. Improving the cleaning capacity of the cleaning agent is of great significance for saving water and energy. For many years, the textile printing and dyeing industry has been committed to strengthening the relative movement between the washing liquid and the fabric to improve the efficiency of the washing equipment. In 1980, Girmes Werke, a German company, proposed the foam cleaning process to achieve continuous washing with as little water and energy as possible. The key to this process is to provide a cleaning agent that produces foam, has no affinity with the fabric, and has a strong adsorption force with the substance being washed. The cleansing agent proposed by the company is composed of anionic surfactant and PVP. PVP is a substance with high adsorption capacity that meets the above requirements. PVP can interact with surfactants to generate surfactant-polymer-adsorption complexes, which have similar properties to micelles and dissolved dyes. The foam containing PVP in the foam liquid plays the role of adsorption and transport. The experiment was carried out on a velvet fabric with a water-soluble black dye solution. A tube with a moving nozzle was applied to the back of the fabric (suede down), and then through a suction roll, 80% of the foam with dye and slurry was absorbed, and then washed with water to remove the remaining foam. Measuring the color fastness of the washed fabric shows that, if the usual washing method is used, many stages of series equipment can be used to achieve the same effect. In this experiment, the liquid contained 20g /l anionic surfactant, 30g /l PVP, the ratio of liquid to foam was 1:8, the foam height was 1-10cm, and the temperature was 60-95 ℃.

In addition to the foam cleaning process, the transfer cleaning process that saves time and materials is also applied. PVP is the key component of cleaning agent. An article on dyeing both sides of cotton fabric to different depths in India also includes the use of a cleanser containing PVP.

In summary, due to its excellent colloidal protection properties and dye affinity, PVP is attractive as a cleaning agent in the printing and dyeing industry. It is combined with certain surfactants, bleach and other washing AIDS, can be prepared to meet certain requirements of efficient cleaning agent, anti-white soil stain agent or levelling agent, the specific formula should be determined by experiment according to the requirements.

Application of PVP in the field of new materials

First, the application of PVP in color picture tube photoresist

The water-soluble photosensitive adhesive used in the Black Matrix of color picture tube is the key material for the production of color tube. The substitution of dichromic acid-PVA by the mixture of aromatic azides, PVP and PAM is an important progress of color tube photosensitive adhesive. PVP plays an important role in improving the photosensitive properties, bonding properties and leveling properties of photosensitive adhesives. Many large color tube factories at home and abroad use PVP azide compound as an important component of water-soluble photosensitive adhesive. Due to the strict requirements for the black-and-white stripe interface heterogeneity (less than 0.01mm) after the development of the photosensitive adhesive, the quality requirements for the PVP K90 used for the photosensitive adhesive, especially the requirements for molecular weight, viscosity and impurities, are higher than the general industrial specification products. In order to ensure the stability of color tube production quality, polymerization system and polymerization process of PVP K90 should be studied and adjusted.

In addition to being used on color tubes, the photosensitive resist can also be used on circuit boards, printed boards and other occasions.

In addition to water-soluble photosensitive adhesives, PVP is also used in color tube shade coatings, conductive coatings and photosensitive materials for fluorescent screens. In these color tube materials, PVP is mainly used as the dispersant and binder of the active component.

Second, the application of PVP in other new materials

PVP can be used in the manufacture of various functional membrane materials to improve membrane selectivity. For example, by adding 1-4% PVP to cellulose acetate, a hemodialysis membrane can only pass through inulin but not plasma. The permeability of water vapor can be increased by increasing the content of PVP in hydroxypropyl cellulose. The membranes made of cellulose acetate phthalate and PVP can be used as reverse osmosis membranes to filter organic solvents. PVP can also be used to improve the reverse osmosis membrane for desalting seawater and increase its transmittance. In the process of preparing ultrafiltration and nanofiltration membranes with various polymer materials, PVP with different molecular weights is widely used as pore-causing agents, so as to obtain membrane separation materials with different separation accuracy and different adaptation properties, which are widely used in seawater desalination, water treatment, product concentration and purification. At present, the global PVP used for membrane material production is about 2000 tons/year, accounting for about 4% of the total consumption of PVP.

PVP can be used to stabilize photooxidation/reduction dyes in photocells or solar cells, and can also be used as a solid electrolyte binder in aluminum electrolytic capacitors or as a binder for flat glass and ionic electrodes. PVP and Cd2O3 can be used as battery electrodes when mixed under heating and pressurization. The electrodes of self-supporting porous Ni-CD and Ni-Fe alkaline batteries can be prepared by sintering 75-98% Ni powder and 2-2.5% PVP at 1700 ℃ for 10 minutes. PVP can also be used to fix magnesium powder on stainless steel fiberboard as a battery electrode. In these cases, PVP is used as a binder and dispersant for metal powders.

 

PVP can be used in diazo and silver halide emulsions, etching coatings and printing plates to form light-cured water-soluble colloid, which can increase the covering power, density, contrast and speed of the colloid. In metal sensitive plates, the use of PVP can eliminate deep etching, and ensure uniform viscosity, stable temperature, and strong adhesion in non-imaging areas. For silver halide emulsions, PVP is a very effective protective colloid. PVP can also be used as a processing aid in the development of silver halide colloid to remove the rust of dichromate salt.

In the field of new technologies such as drag reducing coatings, optical fiber and laser optic disc, the excellent properties of PVP have also been paid attention and studied.

The copolymer of NVP with hydroxyl (b) ethyl methacrylate or ethylene glycol ester or the graft polymer of the latter on PVP can be made into a highly absorbent soft contact lens. Its water absorption rate can be as high as 90%, with good water permeability, air permeability and mechanical strength.

The research of PVP and active metal complexes as hydrogenation catalysts has attracted much attention. For example, PVP-Palladium complex with silica as the carrier can catalyze the hydrogenation reduction reaction of aromatic nitro compounds at room temperature and pressure, and its catalytic activity is higher than that of conventional catalysts. The hydrogenation yield of p-nitrobenzene and dinitrobenzene can reach 100%. Adding an appropriate amount of acetic acid to the system can significantly improve its catalytic activity, and recycling hardly reduces the catalytic activity.

In short, the application of PVP in the high-tech field in recent decades is endless, too numerous to list, involving tens of thousands, but all the changes are inseparable, any new application is related to the excellent performance of PVP, and the most concerned is still its water solubility, film formation, adhesion, complexation, colloidal protection and low toxicity.

The use of PVP in other areas
PVP can be used as a slurry additive in the oil recovery industry to increase viscosity and cure time and reduce water loss. It is a very stable acid gel for acid cracking operations. Because it is less sensitive to the concentration of salt, it can be used as a tool for polymer flooding at high salt concentrations. In the area of surfactant flooding, such as the injection of PVP aqueous solution before surfactant injection, the loss of surfactant can be greatly reduced.

PVP is used in all types of papermaking technologies, regardless of the source of the papermaking material. It has a wide range of uses, including improving the wet strength, improving the solubility of dyes and the dispersion of pigments, and is an excellent auxiliary for deinking, beating and coloring. As an anti-caking agent and flow aid for coatings, PVP makes the final paper product smooth, oil proof and good printing performance. For those occasions where the paper is still wet after coating, PVP can prevent the paper from curling and wrinkling.

PVP is the main type of polymer quenching agent. Polymer quenching agent can improve the cooling characteristics of water, and its main advantages are (1) reduce the risk of fire: using PVP as quenching agent can avoid the fire easily caused by oil bath; (2) The operation can be flexible: by controlling the concentration, temperature and stirring of PVP solution, a series of cooling rates can be controlled accordingly, so that a series of substances can be better quench; (3) Reduce the cost of quenching: commercial PVP is generally a high-concentration solution, the price is higher than the oil used for quenching, but because the quenching only requires a very low concentration of PVP solution, the actual price is much lower than the oil; (4) Maintain a clean environment: ordinary heat treatment workshops pollute the environment due to oil residues, silt, and toxic gases released. After using PVP as quenching agent, only water vapor is released without the above pollution. In the United States, the Environmental Protection Commission has banned the use of oil hardening agents in many areas; (5) Reduce operating costs: Because of the reduction of the hidden danger of fire, in a sense, it is to reduce costs. In addition, the specific heat of PVP quenching solution is almost twice that of oil, so the temperature rise of PVP quenching agent is only half that of the same volume of oil, which can improve the quenching yield.

Meszaros in the United States first proposed that PVP aqueous solution could be used as a quenching agent in 1975, with an average molecular weight of 160,000(that is, PVPK-60) and a concentration of 10%, since then PVP products have been applied as a quenching agent in the United States, and have been promoted around the world. The global PVP used for metal heat treatment is about 400 tons/year, accounting for about 10% of PVP consumption.

Since PVP is non-phytotoxic, it can be used in plant protection sprays, fertilizers, and wettable pesticides. PVP film protects the leaves from wilting during transplantation and reduces the damage from wind and frost. PVP can reduce seed soaking damage and protect its physiological function. Pvp-iodine is an effective fungicide and insecticide with low toxicity to plants. Especially in aquaculture, the aquaculture water and aquaculture equipment can be sterilized and disinfected, greatly reducing the disease caused by bacteria to fish, bullfrog, shrimp and other aquatic products; In dairy farming, it can be used as a disinfectant for milk udders and milkers, which greatly reduces the occurrence of mastitis in dairy cows.

Due to the excellent performance of PVP, PVP has been found to have many new applications in recent decades. By using new polymerization technology and copolymerization method, the properties of NVP polymers can be further improved, thus opening up some new application fields.

The application of PVP in chemical reaction and analytical chemistry

1. Application of PVP in polymerization reaction
The viscosity and colloidal protection function of PVP make it have important applications in polymerization reactions, especially in emulsion polymerization and suspension polymerization, adding a small amount of PVP can play a role in dispersion stability, thickening and particle size control, such as suspension polymerization of methacrylate and polyamine ester. In the emulsion polymerization system of acrylate and vinyl acetate, appropriate amount of PVP-K60 or PVP and styrene copolymer was added to make the reaction system disperse uniformly and stably, and the viscosity, polymer particle size and particle size distribution could be adjusted by adjusting the molecular weight and dosage of PVP, and some properties of the resin could be improved. When ~3% PVPK60 was added to the suspension polymerization of polyurethane, the polymer powder size was uniform, the particle size was between 800~100 microns, and the residual monomer was less than 0.5%. Can be used in coatings, binder, laminate composite materials, made of film, thickness of up to 100 microns, as a coating, coating degree can be as small as 10 microns.
In some emulsion polymerization systems, PVP-K15 or PVP-K30 with lower molecular weight can make the reaction more complete, increase the polymerization rate and improve the mechanical properties of the polymer. For example, when PVP-K15 is added as an emulsifier, the polymerization of methyl methacrylate can be completed within half an hour at 50 degrees, and the resulting polymer elastic temperature range is 120 to 280 degrees, while the polymer elastic temperature range is relatively narrow, 120 to 150 degrees, without PVP. It also shows that the polymer obtained by using PVP as dispersion stabilizer has good thermal stability.
2.PVP can be used in analytical chemistry and catalysts
The aqueous solution of PVP can be divided into liquid-liquid or liquid-solid phases in the presence of different amounts of (NH4) 2SO4. This system is used for the extraction separation of metal ions by organic solvents, and a new extraction system can be obtained. The system has a good extraction effect for some metal ions, such as PVP- (NH4) 2SO4-H2O system containing PVP20%, using arsine azo (III) as the extraction agent to react in the solution containing Zr (IV), La (III) ions to form a complex, under certain conditions, The chelate of Zr (IV) and arsine azo has a high extraction rate in the PVP phase, while the extraction rate of La (III) is very low, so as to achieve the purpose of separating Zr (IV) and La (III). In addition, PVP has good complexation with some metals. For example, PVP and a small amount of Cd can be complexed to produce PVP-CD, using this property can successfully measure a small amount of cadmium. In addition, related studies have reported that for methanol gas phase carbonylation, the activity and selectivity of carbon-supported collolawrencium catalyst (PVP-RH /C) is much higher than that of simple carbon-supported rhodium catalyst, because the lawrencium collolawrencium catalyst formed with PVP has narrow particle size distribution, high dispersion and larger specific surface area. The selectivity of the reaction was improved as well as the catalytic activity.
PVPK30, PVPK17, PVPK90 in ultrafiltration membrane, microfiltration membrane, nanofiltration membrane, hollow fiber membrane application:

Due to the special requirements of the PVP resin series applied as a porer in membrane technology on its molecular weight distribution width, conventional PVP products are far from meeting its requirements, the narrower the molecular weight distribution, the more uniform the pore size distribution of the film made of it, the greater the water flux, and the longer the service life, while the domestic production of conventional PVP products are far from meeting its requirements. As a result, many PVP series applied in high-end water treatment films have to rely on imports (BASF,ISP). In order to meet the needs of the market, the company has cooperated with a number of research institutions to produce a pore-causing agent PVP resin (K17 K30 K90) specifically for the application of membrane technology, and the product quality is close to the requirements of BASF corresponding products.
Suitable for the use of hollow fiber membranes, polymeric pore-causing agent and non-solvent are added to the membrane forming polymer according to the membrane pores to form a spinning composition, wherein the melt spinning composition includes a film forming polymer: heating to the melting temperature of the film forming polymer, and then the melt is extruded in the spinning head, cooling into a film, and then the polymer pore-causing agent and non-solvent are removed; Among them, the film-forming polymer is polyethylpyrrolidone, a polymer pore-causing agent in polyvinylidene fluoride, polyperfluoroethylene, polyether and polyether sulfone, which requires the polymer distribution to be narrow, uniform and have a certain hydrophilicity. Improve the hydrophilicity of membrane materials, in the general water treatment of ultrafiltration, microfiltration can provide K17, K30, K90.

Application of polyvinylpyrrolidone PVP in chemical reaction and analytical chemistry

Application of PVP in polymerization reaction
The viscosity and colloidal protection function of PVP make it have important applications in polymerization reactions, especially in emulsion polymerization and suspension polymerization, adding a small amount of PVP can play a role in dispersion stability, thickening and particle size control, such as suspension polymerization of methacrylate and polyamine ester. In the emulsion polymerization system of acrylate and vinyl acetate, appropriate amount of PVP-K60 or PVP and styrene copolymer was added to make the reaction system disperse uniformly and stably, and the viscosity, polymer particle size and particle size distribution could be adjusted by adjusting the molecular weight and dosage of PVP, and some properties of the resin could be improved. When ~3% PVPK60 was added to the suspension polymerization of polyurethane, the polymer powder size was uniform, the particle size was between 800~100 microns, and the residual monomer was less than 0.5%. Can be used in coatings, binder, laminate composite materials, made of film, thickness of up to 100 microns, as a coating, coating degree can be as small as 10 microns.

In some emulsion polymerization systems, PVP-K15 or PVP-K30 with lower molecular weight can make the reaction more complete, increase the polymerization rate and improve the mechanical properties of the polymer. For example, when PVP-K15 is added as an emulsifier, the polymerization of methyl methacrylate can be completed within half an hour at 50 degrees, and the resulting polymer elastic temperature range is 120 to 280 degrees, while the polymer elastic temperature range is relatively narrow, 120 to 150 degrees, without PVP. It also shows that the polymer obtained by using PVP as dispersion stabilizer has good thermal stability.

PVP is used in analytical chemistry and catalysts

The aqueous solution of PVP can be divided into liquid-liquid or liquid-solid phases in the presence of different amounts of (NH4) 2SO4. This system is used for the extraction separation of metal ions by organic solvents, and a new extraction system can be obtained. The system has a good extraction effect for some metal ions, such as PVP- (NH4) 2SO4-H2O system containing PVP20%, using arsine azo (III) as the extraction agent to react in the solution containing Zr (IV), La (III) ions to form a complex, under certain conditions, The chelate of Zr (IV) and arsine azo has a high extraction rate in the PVP phase, while the extraction rate of La (III) is very low, so as to achieve the purpose of separating Zr (IV) and La (III). In addition, PVP has good complexation with some metals. For example, PVP and a small amount of Cd can be complexed to produce PVP-CD, using this property can successfully measure a small amount of cadmium. In addition, related studies have reported that for methanol gas phase carbonylation, the activity and selectivity of carbon-supported collolawrencium catalyst (PVP-RH /C) is much higher than that of simple carbon-supported rhodium catalyst, because the lawrencium collolawrencium catalyst formed with PVP has narrow particle size distribution, high dispersion and larger specific surface area. The selectivity of the reaction was improved as well as the catalytic activity.
Application of polyvinylpyrrolidone PVP in agriculture
PVP in agriculture application: PVP as a synthetic water-soluble polymer compounds, with the general properties of water-soluble polymer compounds, colloidal protection, film formation, adhesion, hygroscopic, solubilization or condensation, but its characteristics, so people pay attention to its excellent solubility and physiological compatibility. In synthetic polymers such as PVP both soluble in water, but also soluble in most organic solvents, very low toxicity, good physiological compatibility is rare, especially in medicine, food, cosmetics, which are closely related to people’s health in the field, with the reduction of the price of its raw material butyrolactone, will show its good prospects for development. In agriculture, adding a certain amount of PVP to pesticides not only plays the role of solubilization, but also improves the adhesion between pesticides and plants and improves the insecticidal effect. Adding appropriate amount of PVP to fertilizer can improve the utilization rate of active ingredients in fertilizer. Seed coating, prevent seeds frostbite, prevent the invasion of mold. As the country pays more and more attention to environmental protection and safety, PVP has a broader application space in agriculture.
The application and advantages of PVP in quenching agent
PVP is the main type of polymer quenching agent. Polymer quenching agent can improve the cooling characteristics of water, its main advantages are (1) reduce the risk of fire: PVP as quenching agent can avoid the fire easily caused by oil bath; (2) The operation can be flexible: by controlling the concentration, temperature and stirring of PVP solution, a series of cooling rates can be controlled accordingly, so that a series of substances can be better quench; (3) Reduce the cost of quenching: commercial PVP is generally a high-concentration solution, the price is higher than the oil used for quenching, but because the quenching only requires a very low concentration of PVP solution, the actual price is much lower than the oil; (4) Maintain a clean environment: ordinary heat treatment workshops pollute the environment due to oil residues, silt, and toxic gases released. After using PVP as quenching agent, only water vapor is released without the above pollution. In the United States, the Environmental Protection Commission has banned the use of oil hardening agents in many areas; (5) Reduce operating costs: Because of the reduction of the hidden danger of fire, in a sense, it is to reduce costs. In addition, the specific heat of PVP quenching solution is almost twice that of oil, so the temperature rise of PVP quenching agent is only half that of the same volume of oil, which can improve the quenching yield.