CN114230839B

CN114230839B - Rapidly degradable polyvinyl alcohol packaging film

Info

Publication number: CN114230839B
Application number: CN202210104011.9A
Authority: CN
Inventors: 孙琇芳
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-01-28
Filing date: 2022-01-28
Publication date: 2023-11-17
Anticipated expiration: 2042-01-28
Also published as: CN114230839A

Abstract

The invention provides a quick degradable polyvinyl alcohol packaging film, which is formed by printing a polyurethane resin layer which can be slowly dissolved after absorbing water in water on two sides of a low molecular weight polyvinyl alcohol film with the alcoholysis degree of 89-90%. The properties of moisture absorption or water absorption, no stickiness, no hand adhesion and no rupture of the surface of the polyvinyl alcohol film are obtained. Therefore, the plastic packaging bag can be widely applied to the manufacture of various packaging bags, shopping bags, convenient bags and garbage bags in daily life, and can also be applied to the packaging materials of shoe industry, clothing industry, cultural industry, daily necessities, industrial parts and various dry matters. The waste after the quick degradable polyvinyl alcohol packaging film is used can be directly dissolved by cold water or hot water and then directly discharged, and can also be kneaded into particles for recycling after being soaked by hot water. After being discharged, the dissolved substances in the water can be quickly absorbed by microorganisms to be biodegraded, and the degraded substances are nontoxic, odorless and pollution-free, so that the white pollution of the waste is eliminated.

Description

Rapidly degradable polyvinyl alcohol packaging film

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a rapidly degradable polyvinyl alcohol packaging film.

Background

With the great abundance of social development and materials, packaging films of various products and shopping bags of various daily living goods, packaging convenience bags and various plastic packages are increasingly demanded. In recent years, among garbage streams, waste plastic packages and plastic packaging bags have been the fastest growing. It is counted that the garbage accounts for 14% -28% of the volume of the solid garbage, accounts for about 9% -12% of the volume of the solid garbage landfill, and only a small part of the garbage is recycled.

Most of the existing packaging films are made of polyolefin and polyvinyl chloride, can not be dissolved in water in a short time, can not be dissolved in water at normal temperature, can not be degraded, and even a very small number of packaging films are made of degradable materials, can not be dissolved in water in 24 hours, so that wastes are caused, and the packaging films drift along with wind in the nature, pollute urban environment and natural ecological environment, and cause serious white pollution. Even in the natural rivers, lakes, seas, serious "white pollution" is caused. The pollution problem of the waste plastic packaging film is needed to be solved.

Disclosure of Invention

The invention aims to provide a quick degradable polyvinyl alcohol packaging film so as to solve the problems.

The invention is realized by the following technical scheme: a kind of quick degradable polyvinyl alcohol packaging film, characterized by: respectively printing a layer of water-soluble polyurethane resin printing liquid on two sides of the water-soluble polyvinyl alcohol film;

the water-soluble polyurethane resin layer printing liquid comprises the following components in percentage by mass:

60% -70% of aqueous polyurethane resin liquid; 0.5% -1.5% of hydroxyethyl cellulose; 0.5% -1% of di (dioctyl phosphoryloxy) ethylene titanate; 1% -3% of ethylene glycol; 0.5 to 3 percent of film forming agent; 0.2 to 0.8 percent of alkyl dimethyl quaternary ammonium salt; 1% -5% of polyvinylpyrrolidone; 0.3 to 0.8 percent of polyoxypropylene ethylene oxide glycerol ether; 0.5 to 1.5 percent of neutralizer; 3% -10% of carbohydrate aqueous solution; 5% -15% of cosolvent; the balance of water.

Further: the alcoholysis degree of the water-soluble polyvinyl alcohol film is 89% -90%; the molecular weight is 10000-50000; the elongation at break is 50% -600%, the tensile strength is 200 mpa.s-300 mpa.s, and the thickness is 25um-40um.

Further: the water solubility of the polyvinyl alcohol film is that cold water and hot water are both soluble or cold water is slowly soluble.

Further: the water-soluble polyurethane resin layer is prepared by printing aqueous polyurethane resin printing liquid.

Further: the polyurethane in the water-soluble polyurethane resin printing liquid is single-component self-emulsifying water-soluble polyurethane, and the molecular weight is 25000-35000; the solid content of the resin liquid is 20% -50%, and the grain size is 0.01um-3um; is transparent after infinitely diluted with water.

Further: the film forming agent is as follows: one of ethylene glycol, propylene glycol, diethylene glycol and methoxypropanol; the neutralizer is as follows: one of monoethanolamine, diethylamine, triethylamine and ammonia water; the cosolvent is as follows: ethanol, isopropanol, or n-butanol.

Further: the solid content of the polyurethane resin printing liquid is 25-35%, the viscosity is 12s-15s/3 # cup, and the PH value is 7-7.5.

Further: the thickness of the polyurethane resin layer is 5-15um.

The invention has the advantages that: the water solubility of the rapidly degradable polyvinyl alcohol packaging film provided by the invention is as follows: insoluble in normal temperature water for 1h, gradually dissolving in water for 2h-26h, completely dissolving in water in hot water for 20h, and completely dissolving in water in normal temperature seawater for 40 h. Can be completely degraded in 17-30 days in the ground illumination environment.

The rapidly degradable polyvinyl alcohol packaging film provided by the invention can obtain different water-soluble time and degradation speed of the polyvinyl alcohol film by adjusting the thickness of the polyurethane resin printing layer. The thinner the polyurethane print layer, the faster the water dissolution rate, and the thicker the polyurethane print layer, the slower the water dissolution rate.

The rapidly degradable polyvinyl alcohol packaging film provided by the invention can be immersed in water at any time after being used, and wastes such as shopping bags and the like of the waste packaging film are dissolved in water after 26 hours, can be directly discharged, can also be immersed in hot water at 50-60 ℃ at any time, and can be taken out, kneaded into a ball shape, naturally dried and recycled after absorbing water. The white pollution of the plastic film is eliminated.

The rapidly degradable polyvinyl alcohol packaging film provided by the invention can rapidly degrade wastes in natural environment, has no toxicity, no smell and no environmental pollution, has complexation and water retention effects on soil, and is beneficial to plant growth.

The quick degradable polyvinyl alcohol packaging film provided by the invention adopts water-soluble polyurethane resin in the production process, takes water as a solvent, has no harmful gas release in the production process, has no harm to equipment, environment, production personnel and users, and belongs to an environment-friendly product.

Detailed Description

The invention provides a quick degradable polyvinyl alcohol packaging film, which is characterized in that two sides of a water-soluble polyvinyl alcohol film are respectively printed with a water-soluble polyurethane resin layer.

In the invention, the alcoholysis degree of the water-soluble polyvinyl alcohol film is 89% -90%; the molecular weight is 10000-50000; the elongation at break is 50% -60%; the tensile strength is 200 MPa.s-300 MPa.s; the thickness of the film is 25-40 um, and the water solubility of the polyvinyl alcohol is that cold water and hot water are both soluble.

In the embodiment of the invention, the alcoholysis degree is preferably 89.5%; the molecular weight is 15000, the elongation at break is 450%, and the tensile strength is 250 MPa.s; the thickness of the film is 30-35 um, and the water solubility is that both cold water and hot water are soluble.

In the invention, the polyurethane resin layer is prepared by printing water-soluble polyurethane printing liquid, and the water-soluble polyurethane resin layer printing liquid comprises the following components in percentage by mass: 60% -70% of aqueous polyurethane resin liquid; 0.5% -1.5% of hydroxyethyl cellulose; 0.5% -1% of di (dioctyl phosphoryloxy) ethylene titanate; 1% -3% of ethylene glycol; 0.5 to 3 percent of film forming agent; 0.2 to 0.8 percent of alkyl dimethyl quaternary ammonium salt; 1% -5% of polyvinylpyrrolidone; 0.3 to 0.8 percent of polyoxypropylene ethylene oxide glycerol ether; 0.5 to 1.5 percent of neutralizer; 3% -10% of carbohydrate aqueous solution (concentration is 2% -5%); 5% -15% of cosolvent; the balance of water.

In the invention, the water-soluble polyurethane resin printing liquid comprises 60-70% of water-based polyurethane resin liquid, preferably 62-68%; more preferably 65% -66%; the polyurethane is single-component self-emulsifying polyurethane, and the molecular weight is 25000-35000, preferably 28000; the solids content is 20% to 50%, preferably 25% to 48%, more preferably 35% to 45%. The grain size is 0.01um-3um, preferably 1um-2.8um, more preferably 2.5um, and the resin liquid is transparent after infinitely dilution with water.

In this example, the aqueous polyurethane resin solution is purchased from the ink product of Tianjin Japan and may be other commercial products.

In the invention, the aqueous polyurethane resin printing solution comprises 0.5-1.5% of hydroxyethyl cellulose, preferably 0.8-1.3%, and more preferably 1-1.2%.

In the invention, the aqueous polyurethane resin printing solution comprises 0.5-1% of di (dioctyl phosphoryloxy) ethylene titanate, preferably 0.8-0.9%, more preferably 0.8-0.85%.

In the invention, the aqueous polyurethane resin printing solution comprises 1-3% of glycol, preferably 1.5-2.8%, and more preferably 2-2.5%.

In the invention, the aqueous polyurethane resin printing solution comprises 0.5-3% of film forming agent, preferably 1-2.8%, more preferably 1.5-2.5%. In this embodiment, the film former is preferably ethylene glycol.

In the invention, the aqueous polyurethane resin printing solution comprises 0.2-0.8% of alkyl dimethyl quaternary ammonium salt, preferably 0.3-0.7%, more preferably 0.4-0.6%.

In the invention, the aqueous polyurethane resin printing solution comprises 1-5% of polyvinylpyrrolidone, preferably 2-4%, more preferably 3-3.5%.

In the invention, the aqueous polyurethane resin printing solution comprises 0.3 to 0.8 percent of polyoxypropylene ethylene oxide glycerol ether, preferably 0.4 to 0.7 percent, and more preferably 0.5 to 0.6 percent.

In the invention, the water-based polyurethane resin printing solution comprises 0.5-1.5% of neutralizer, preferably 0.8-1.3%, and more preferably 1-1.1%. The neutralizer comprises: monoethanolamine, diethylamine, triethylamine and aqueous ammonia. One of them. In this embodiment, the neutralizing agent is preferably monoethanolamine.

In the invention, the aqueous polyurethane resin printing solution comprises 3-10% of carbohydrate (2-5% concentration) aqueous solution, preferably 5-8%, more preferably 6-7%.

In the invention, the aqueous polyurethane resin printing solution comprises 5-15% of cosolvent, preferably 8-13%, more preferably 10-12%. The cosolvent comprises: ethanol, isopropanol, n-butanol, one of them. In this embodiment, the cosolvent is preferably n-butanol.

In the invention, the water-based polyurethane printing resin liquid comprises a proper amount of water, and the water is drinking water.

In the invention, the polyurethane resin printing liquid is prepared by adopting a gravure water-based printing ink preparation method, the solid content of the printing liquid is 25% -35%, preferably 30% -32%, and the viscosity of the printing liquid is 12s-15s (No. 3 cup), preferably 13s-14s (No. 3 cup).

In the invention, the rapidly degradable polyvinyl alcohol packaging film is prepared by adopting a gravure printing process.

In the invention, the depth of the ink containing holes of the gravure printing plate roller is 2um-15um, preferably 4um-12um, and the distance between the printing plate roller and the oven is 150mm-200mm, preferably 180mm; the printing line speed is 20-30 m/min, preferably 25-26 m/min, the printing drying temperature is 50-55deg.C, preferably 25-26 m/min, and the printing drying temperature is 50-55deg.C, preferably 52 deg.C. The ambient temperature is normal temperature, the ambient humidity is 45% -55%, and preferably 50%.

In the invention, water is a diluent of printing ink, the water is deionized water, and when the viscosity of printing liquid is more than 15s (No. 3 cup) in the printing process, the printing liquid is required to be supplemented with solvent for dilution, and the proportion is as follows: water + co-solvent = 95:5, adding the mixture into the printing liquid after uniformly mixing, wherein the adding amount is not more than 5% each time, slowly adding the mixture for three times, and uniformly stirring the mixture while adding the mixture.

In the invention, in order to improve the drying speed of the water-based printing liquid, two plate rollers are selected for synchronous superposition printing, the total thickness of superposition printing of the two plate rollers is 5um-15um, the second surface is printed after one surface is printed, rewinding and drying are carried out after all the surfaces are printed, the drying temperature is 50+/-3 ℃, and the drying linear speed is 20m/min-30m/min, preferably 25 m/min.

In the invention, the rapidly degradable polyvinyl alcohol film is rolled after printing, trimmed, and placed for 72 hours before packaging, wherein the inner layer of the package is wax-coated moisture-proof kraft paper, and the outer layer of the package is PP film.

The invention tests the water solubility of the quick degradable polyvinyl alcohol film, which comprises the following steps:

1. the film of the invention is stuck on a nylon screen, immersed in warm water (the water is tap water), and the water-soluble speed is observed at regular time;

2. films with the same specification and thickness are stuck on a nylon net and immersed in hot water at 60 ℃ to observe the water dissolution rate at regular time;

3. films with the same specification and thickness are stuck on a nylon net and immersed into a seawater container at normal temperature, and the water dissolution speed is observed in a timing way.

Test results are shown in Table I and Table II

Experiments prove that:

the quick degradable polyvinyl alcohol packaging film disclosed by the invention comprises:

in fresh water, the film of 35um-75um is completely dissolved in water within 24h-26 h.

In seawater, the film of 35um-75um is totally dissolved in water within 40 h.

The invention tests the degradation performance of a rapidly degradable polyethylene film, and the testing method comprises the following steps:

four sides of the 35um-75um rapidly degradable polyvinyl alcohol packaging film are adhered to a nylon net, placed in the natural world or placed on the ground where illumination exists, degradation time is observed, and test results are shown in a table (III):

the invention tests the moisture absorption performance of the quick degradable polyvinyl alcohol film: the test method is that the film which can be rapidly degraded with 35um to 75um is put into the environment with 50 percent to 98 percent of humidity, and the hygroscopicity is observed as shown in the table (IV).

Table (III) experiments demonstrate that:

the rapidly degradable polyvinyl alcohol film of the invention can be completely degraded in 17-30 days in the ground illumination environment when the film thickness is 35-75 um.

Table (IV) experiments demonstrate that:

when the film thickness is 35um-75um, the moisture absorption is small in the environment with the temperature of 30 ℃ and the relative humidity of 50-98%, and the moisture absorption is little in the environment with the humidity of less than 85%.

The present solution is further described below by means of specific examples.

Example 1-example 3 formulation design: the polyurethane resin printing solution comprises the following components in percentage by mass:

formulation components	Example 1	Example 2	Example 3
				Aqueous polyurethane resin liquid	70%	65%	60%
Hydroxyethyl cellulose	1.5%	1%	0.5%
				Di (dioctyl phosphoryloxy) ethylene titanate	1%	0.8%	0.5%
Ethylene glycol	1.5%	3%	1%
				Film forming agent	0.5%	1.5%	3%
Alkyl dimethyl quaternary ammonium salt	0.2%	0.8%	0.5%
				Polyvinyl pyridone	5%	3%	1%
Polyoxypropylene ethylene oxide glycerol ether	0.8%	0.5%	0.3%
				Neutralizing agent	1%	1.5%	0.5%
Carbohydrate aqueous solution (concentration 2% -5%)	3%	10%	5%
				Cosolvent	10%	8%	5%
Water and its preparation method	Proper amount of	Proper amount of	Proper amount of

In the invention, the quick degradation type polyvinyl alcohol packaging film can be made into a transparent film, and also can be added with a proper amount of pigments with various colors to be made into films with different colors. The embodiment of the invention takes a transparent film as an example.

Example 1-example 3

The thickness of the polyvinyl alcohol film is selected: 20um; example 2:30um; example 3:40um. The neutralizing agent is monoethanolamine, the cosolvent is n-butanol, and the film forming agent is glycol.

Example 1

Example 1 preparation

The preparation method of the gravure printing aqueous ink is characterized in that an aqueous polyurethane resin layer is prepared into polyurethane resin layer printing liquid by adopting a gravure printing aqueous ink preparation method, and the preparation process comprises the following steps:

70 parts of the aqueous polyurethane resin solution in example 1, 1.5 parts of hydroxyethyl cellulose, 1 part of ethylene bis (dioctyl phosphoryloxy) titanate, 1.5 parts of ethylene glycol, 0.5 part of film forming agent, 0.2 part of alkyl dimethyl quaternary ammonium salt, 5 parts of polyvinylpyrrolidone and 3 parts of carbohydrate are sequentially placed into a mixer to be mixed for 60 minutes at a speed of 120r/min, and then 1 part of neutralizing agent is added to be mixed for 10 minutes continuously, so as to obtain a first mixed solution.

Adding 10 parts of cosolvent into a proper amount of water, uniformly mixing, slowly adding into the first mixed solution, continuously mixing at the same speed for 10min to adjust the solid content of the solution to be 30 percent, the viscosity to be 13 s/(25 ℃) (No. 3 cup), finally adding 0.8 part of polyoxypropylene ethylene oxide glycerol ether, continuously uniformly stirring, standing for 60min, and filtering to obtain the polyurethane printing resin liquid.

And (3) placing a 20 um-thick polyvinyl alcohol film on a gravure printing frame, placing polyurethane resin printing liquid into an ink tank, starting up to adjust the printing speed to 25m/min, enabling the temperature of an oven to be 50 ℃, enabling the distance between a printing plate roller and the oven to be 100mm, enabling the ambient temperature to be normal temperature and the ambient humidity to be 40%, synchronously printing by adopting two plate rollers, synchronously overlapping and printing the total thickness of the two plate rollers to be 4um-12um, printing a second surface by using the same printing process strip after the printing of the first surface is finished, and enabling the total thickness of the film to be within 28um-44um after the whole printing is finished.

After the first surface is printed, the second surface is printed after rewinding and drying is carried out at the line speed of 35m/min and the air drying temperature of 50+/-3 ℃.

After all printing is finished, trimming, rolling and packaging are carried out, the inner layer is packaged by moistureproof paraffin-hanging kraft paper, the outer layer is packaged by PP packaging films, and the packaging is carried out after standing for 72 hours before packaging.

Example 2

65 parts of aqueous polyurethane resin solution, 1 part of hydroxyethyl cellulose, 0.8 part of diethyl (dioctyl phosphoryloxy) titanate, 3 parts of ethylene glycol, 1.5 parts of film forming agent, 0.8 part of alkyl dimethyl quaternary ammonium salt, 3 parts of polyvinylpyrrolidone and 10 parts of carbohydrate in the component of the example 2 are sequentially placed into a mixer to be mixed for 50 minutes at the speed of 150r/min, and then 1.5 parts of neutralizing agent is added to be continued to be mixed for 8 minutes, so that a first mixed solution is obtained.

Adding 8 parts of cosolvent into a proper amount of water, uniformly mixing, slowly adding the first mixed liquid, continuously mixing at the same speed for 8min to adjust the solid content of the solution to 31%, adjusting the viscosity to 13.5 s/(25 ℃) (No. 3 cup), finally adding 0.5 part of polyoxypropylene ethylene oxide glycerol ether, continuously uniformly stirring, standing for 60min, and filtering to obtain the polyurethane printing resin liquid.

The method comprises the steps of putting a 30um thick polyvinyl alcohol film on a shaft frame of a gravure printing machine, putting polyurethane resin printing liquid into an ink tank, starting up to adjust the printing speed to 20m/min, enabling the temperature of an oven to be 52 ℃, enabling the distance between a printing plate roller and the oven to be 150mm, enabling the ambient temperature to be normal temperature and the ambient humidity to be 40%, synchronously printing by adopting two plate rollers, enabling the total printing thickness of the two plate rollers to be 5um-12um, printing a second surface by the same printing process after the printing of the first surface is finished, and enabling the total thickness of the film to be 45um-54um after the whole printing is finished.

After the first surface is printed, the second surface is printed after rewinding and drying are carried out at the line speed of 35m/min and the air drying temperature of 50+/-3 ℃.

Trimming, rolling and packaging after all printing is finished, wherein the inner layer is made of moistureproof paraffin-hanging kraft paper, the outer layer is packaged by a PP packaging film, and the packaging is carried out after standing for 72 hours before packaging.

Example 3

60 parts of the aqueous polyurethane resin solution in example 3, 0.5 part of hydroxyethyl cellulose, 0.5 part of ethylene bis (dioctyl phosphoryloxy) titanate, 1 part of ethylene glycol, 3 parts of film forming agent, 0.5 part of alkyl dimethyl quaternary ammonium salt, 1 part of polyvinylpyrrolidone and 5 parts of carbohydrate are sequentially placed into a mixer to be mixed for 40min at a speed of 180r/min, and then 0.5 part of neutralizing agent is added to be mixed for 5min, so that a first mixed solution is obtained.

Adding 5 parts of cosolvent into a proper amount of water, uniformly mixing, slowly adding into the first mixed solution, continuously mixing for 5 minutes at the same speed, adjusting the viscosity to be 14 s/(25 ℃ C. (No. 3 cup), and finally adding 0.8 part of polyoxypropylene ethylene oxide glycerol ether, continuously stirring uniformly, standing for 60 minutes, and filtering to obtain the polyurethane printing resin liquid.

And (3) feeding a polyvinyl alcohol film with the thickness of 40um into a machine, starting up and adjusting the linear speed to be 25m/min, controlling the temperature of an oven to be 55 ℃, enabling the distance between a printing plate roller and the oven to be 200mm, controlling the ambient temperature to be normal, controlling the ambient humidity to be 40%, adopting two plate rollers to synchronously print, printing the total thickness of the two plate rollers to be 8um-15um, printing a second surface by using the same printing process strip after the first surface is printed, and finishing all printing, wherein the total thickness of the film is within 56um-70 um.

After the first surface is printed, rewinding and drying are carried out at the line speed of 35m/min and the air drying temperature of 50+/-3 ℃ and then the second surface is printed.

After all printing is finished, trimming, rolling and packaging are carried out, wherein the inner layer is made of moistureproof kraft paper, the outer layer is packaged by plastic film, and the packaging is carried out after standing for 72 hours before packaging.

In this example 1-example 3, the rapidly degradable polyvinyl alcohol packaging film was subjected to water solubility and degradation performance test in the same manner as in the above technical scheme, and the test results are shown in table (one), table (two) and table (three).

The rapidly degradable polyvinyl alcohol packaging film can be dissolved in water at any time or dissolved in hot water (60 ℃) to be broken into pieces and then kneaded into a shape for recycling. Eliminates the environmental pollution and white pollution of the waste. "

The quick degradable polyvinyl alcohol packaging film takes water as a solvent in the production process, has no harmful gas release, is harmless to operators, has no harm to soil due to water soluble matters in the use process, and can be directly discharged. And has complexation to soil, which is beneficial to plant growth. The water-soluble substances are nontoxic and odorless, and are slowly absorbed and degraded by microorganisms in the nature.

The fast degradable polyvinyl alcohol packing film of the present invention is suitable for making various shopping bags and packing bags, and is suitable for packing various articles for daily use, and for disposable packing film for clothing, shoes, industry and agricultural products.

The foregoing is only illustrative of specific embodiments of the present invention. It will also be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.

Claims

1. A kind of quick degradable polyvinyl alcohol packaging film, characterized by: respectively printing a layer of water-soluble polyurethane resin layer on two sides of the water-soluble polyvinyl alcohol film; the water-soluble polyurethane resin layer printing liquid comprises the following components in percentage by mass:

60% -70% of aqueous polyurethane resin liquid;

0.5% -1.5% of hydroxyethyl cellulose;

0.5% -1% of di (dioctyl phosphoryloxy) ethylene titanate;

1% -3% of ethylene glycol;

0.5 to 3 percent of film forming agent;

0.2 to 0.8 percent of alkyl dimethyl quaternary ammonium salt;

1% -5% of polyvinylpyrrolidone;

0.3 to 0.8 percent of polyoxypropylene ethylene oxide glycerol ether;

0.5 to 1.5 percent of neutralizer;

3% -10% of carbohydrate aqueous solution;

5% -15% of cosolvent;

the balance of water;

the alcoholysis degree of the water-soluble polyvinyl alcohol film is 89% -90%; the molecular weight is 10000-50000; the elongation at break is 50% -600%, the tensile strength is 200 Mpa.s-300 Mpa.s, and the thickness is 25um-40um;

the polyurethane in the water-soluble polyurethane resin layer printing liquid is single-component self-emulsifying water-soluble polyurethane, and the molecular weight is 25000-35000; the solid content of the resin liquid is 20% -50%, and the grain size is 0.01um-3um; is transparent after infinitely diluted with water.

2. The rapidly degradable polyvinyl alcohol packaging film according to claim 1, characterized in that: the water-soluble polyvinyl alcohol film is soluble in both cold water and hot water.

3. The rapidly degradable polyvinyl alcohol packaging film according to claim 1, characterized in that: the film forming agent is as follows: one of ethylene glycol, propylene glycol, diethylene glycol and methoxypropanol; the neutralizer is as follows: one of monoethanolamine, diethylamine, triethylamine and ammonia water; the cosolvent is as follows: ethanol, isopropanol, or n-butanol.

4. The rapidly degradable polyvinyl alcohol packaging film according to claim 1, characterized in that: the solid content of the polyurethane resin layer printing liquid is 25-35%, the viscosity is 12s-15s/3 # cup, and the pH value is 7-7.5.

5. The rapidly degradable polyvinyl alcohol packaging film according to claim 1, characterized in that: the thickness of the polyurethane resin layer is 5-15um.