CN1294189C - Reaction liquid for modifying polymer film and modifying method - Google Patents

Abstract

The invention provides a reaction solution and a modification method for polymer film modification, which are used to improve the hydrophilicity of the polymer film surface. The components of the reaction solution include acrylic acid and its derivatives, acrylamide and its derivatives, acrylic acid Esters, polar monomers such as N-vinylpyrrolidone and acrylonitrile, hydrogen abstraction photoinitiators such as benzophenone, thioxanthone and its derivatives, anthraquinone and coumarone, and water and alcohols, A mixed solvent composed of organic solvents such as ketones. When performing ultraviolet light grafting treatment, the prepared reaction solution is coated on the film to be treated, irradiated under ultraviolet light, and the treated film is cleaned and dried to obtain a highly hydrophilic modified polymer film. This surface grafting modification method has the advantages of obtaining a uniformly modified polymer surface at a low grafting rate, a long-lasting modification effect, and a simple and easy post-treatment procedure.

Description

A kind of reaction solution and modification method for polymer film modification

Technical field:

The present invention relates to a reaction solution for high-hydrophilicity modification on the surface of polymer film, and also relates to a method for high-hydrophilization modification on the surface of polymer film. Graft polymerization of monomers is a modification method for obtaining high hydrophilicity.

Background technique:

Plastic films are widely used in today's society. The surface properties of organic polymer materials play a vital role in determining their end use, but due to their chemical structure, there are generally problems of low surface energy and poor hydrophilicity. , resulting in difficulty in printing, bonding, dyeing, and wetting by polar solvents such as water, etc., which are not suitable for certain application requirements. The evaluation of surface hydrophilicity is usually indicated by the contact angle formed by water and the surface of the material: the smaller the contact angle, the better the hydrophilicity. For a fully wettable hydrophilic surface, the value of the water contact angle is generally around 20°.

In order to obtain the hydrophilicity of the plastic surface, the current solutions in industrial production include:

1. Add surfactants internally, such as non-drip agricultural plastic greenhouse film, etc. In this method, there are problems of compatibility between the added ingredients and the plastic substrate, which are difficult to overcome, and the added ingredients are continuously precipitated, and the modification effect is difficult to last, and the precipitated ingredients Will cause a certain degree of pollution and other problems;

2. The surface is coated with hydrophilic coatings, such as gelatin coatings used on the surface of the film. This method is only suitable for polymer materials with certain polarity such as polyester. For most non-polar or small polar polymers The base material, generally the adhesion of the coating is poor;

3. Wet surface chemical corrosion method, such as using strong oxidizing reagents such as chromic acid to treat plastics, etc. This method needs to use a lot of chemical reagents, which is inconvenient to operate and causes great pollution;

4. Corona treatment and combined with practical plasma treatment can cause a certain degree of oxidation on the surface of the material. The main disadvantage of corona treatment is that the degree of modification is limited. For example, the surface of biaxially oriented polypropylene after corona treatment The energy is usually 38-40 dynes, the water contact angle is above 85°, and the process conditions are not easy to control. Although plasma treatment can achieve a good degree of modification, it requires expensive processing equipment and vacuum conditions, and the operating cost is high. Continuous surface treatment;

5. Surface graft polymerization modification, this kind of method is through the graft polymerization of small molecular monomers on the surface of the polymer, so that the graft polymer with polar structure is connected to the surface through covalent chemical bonds, so as to achieve improvement For the purpose of surface hydrophilicity, the modification effect is obvious and long-lasting.

The above-mentioned surface grafting modification methods can be divided into:

a. Chemical initiation method, the surface of the polymer reacts with ozone, hydrogen peroxide, etc. to generate peroxyl groups, and then heats to generate surface free radicals. After contacting with modified monomers, graft polymerization occurs to achieve the purpose of modification. This method is a two-step method, which is not easy to improve production efficiency;

b. The high-energy radiation initiation method uses high-energy rays such as gamma-rays or high-energy electron beams to initiate. This method has high implementation costs and low safety and reliability;

c. Ultraviolet light initiation method, using ultraviolet light to initiate grafting reaction, this method has the advantages of simple equipment, less investment, convenient operation, and safety. However, in general, the reaction solution of UV-induced grafting reaction remains homogeneous during the polymerization process, and the solvent used is a good solvent for both the grafted monomer and the polymer, and the grafted polymer is easy to form longer chain molecules and then form entanglements The clump structure of the grafted polymer will cause uneven distribution on the surface of the substrate (see Figures 2, 4, and 6 of Comparative Examples 1, 4, and 5), which will eventually make the surface modification uneven. Satisfactory modification effects can only be obtained when a high grafting rate is achieved so that the grafted polymer covers the surface of the substrate.

Invention content:

In order to overcome the shortcomings of the existing ultraviolet light-induced surface grafting technology that needs to achieve a relatively high grafting rate to obtain a relatively satisfactory treatment effect, the grafting is not easy to be uniform, and the post-treatment is complicated, the present invention provides a method for surface modification of polymer films. properties to obtain a highly hydrophilic reaction solution, this composition is used in the UV-induced grafting process, the solvent is a poor solvent for grafted polymers and homopolymers, and when the grafting reaction is carried out to a certain extent, the generated The homopolymer is precipitated from the system, the system changes from a homogeneous phase to a heterogeneous phase, and the molecular chain of the graft is in a contracted state. The grafting rate of the polymer film substrate is low but the grafting is uniform (see Figures 1, 3, 5 ), a better modification effect can be obtained, and the homopolymer has low adhesion firmness, which can simplify the post-processing procedure.

A kind of reaction solution that is used for the highly hydrophilic modification of polymer film surface among the present invention comprises following components:

1) Polar monomers, selected from at least one of acrylic acid and its derivatives, acrylamide and its derivatives, acrylates, N-vinylpyrrolidone or acrylonitrile, and its weight percentage concentration is 1% of the reaction solution 5-30%;

2) hydrogen abstraction type photoinitiator, at least one selected from benzophenone, thioxanthone and its derivatives, anthraquinone or coumarone, its weight percent concentration is 0.1-3 of the reaction solution %;

3) The balance is a mixed solvent, and the mixed solvent is composed of water with a concentration of 10%-60% by weight and alcohols and/or ketone organic solvents.

Using this reaction solution, since the solvent is a poor solvent for the graft polymer and the homopolymer, the homopolymer will precipitate from the system when it grows to a certain extent, that is, the initial reaction system is a homogeneous system, and when the reaction progresses to a certain extent, the system becomes Heterogeneous phase system; at the same time, the insolubility of the grafted polymer makes the molecular chain difficult to grow long, the chain is short and takes a curled shape, forming a small granular structure that is evenly distributed on the surface of the substrate (see Figures 1, 3, 5), that is, in relatively Uniformly modified polymer surfaces are obtained at low grafting ratios. The homopolymer precipitated from the reaction system generally has a small molecular weight, does not adhere firmly to the surface of the substrate, and is easy to clean and remove. The post-treatment procedure is simple, and it is easy to adopt continuous treatment.

Acrylic acid and its derivatives described in the present invention are selected from acrylic acid, methacrylic acid, etc.; acrylamide and its derivatives are selected from acrylamide, N-methylolacrylamide, etc.; acrylates are selected from methyl acrylate, methyl Methyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, etc.

The alcohols in the present invention are selected from methanol, ethanol, isopropanol, butanol, ethylene glycol, butylene glycol, etc.; the ketones are selected from acetone, butanone, pentanone, cyclohexanone, etc.

The invention also provides a simple, feasible and efficient method for modifying polymer film, so that the polymer film products with low surface energy can obtain long-term high surface hydrophilicity.

The present invention can adopt batch or continuous method to carry out, and batch method comprises the following steps:

1) Preparation of reaction solution: according to the above-mentioned reaction solution component ratio for polymer film modification, polar monomers and hydrogen abstraction photoinitiators are dissolved in a mixed solvent to form a reaction solution;

2) Intermittent treatment of ultraviolet light grafting: use a coating wire rod to evenly coat the prepared reaction solution on the film to be treated, the coating amount of the reaction solution is 5-20g/m ² , and then place it under ultraviolet light ;

3) The photografted film is cleaned with a solvent, and dried to obtain a finished polymer film with a highly hydrophilic surface modification.

The irradiation light source used in the method of the present invention is the irradiation light source commonly used in the ultraviolet photopolymerization technology, as mercury arc lamp (comprising low pressure mercury lamp, medium pressure mercury lamp and high pressure mercury lamp), electrodeless lamp, xenon lamp or metal halide lamp etc. . The suitable wavelength of the light used is 200-400 nm, and the irradiation intensity is 10-100 W/m ² .

The ultraviolet light grafting treatment has no special requirements for the coated wire rods, and what is commonly used in this field is enough.

The film materials that can be processed by the present invention are general-purpose polymer film materials such as polyethylene, polypropylene, polyester, polyvinyl chloride film, etc., with a general thickness of 10 microns to 5 mm. The film to be treated can be compounded with a cover film to remove air from the layer interval, or not compounded with a cover film. The cover film is generally made of polypropylene film, polyethylene film, etc. The transmittance of ultraviolet light is required to be higher than 75%. After the photopolymerization is completed, the treated film needs to be separated from the cover film and then cleaned and dried to obtain a highly hydrophilic surface modification. finished polymer film. The cleaning solvent is generally water.

In the continuous processing process, the second step of continuous UV grafting process is as follows: the film to be treated is continuously carried out on the UV curing machine at a linear speed of 0.1m/min to 50m/min, the reaction solution is placed in a storage tank and Apply evenly on the film to be treated by doctor blade or coating roller, and then irradiate under ultraviolet lamp.

The present invention has no special requirements on the ultraviolet light curing machine, which is commonly used in the field. The grafting rate (G _y ) of the sample is measured by weighing method for the processed sample:

${\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 100</span>}<span\; class="notranslate">\; \%</span>$

Wherein, W _g is the weight of the grafted membrane after treatment, and _W is the weight of the blank membrane before grafting.

The surface hydrophilicity of the treated sample was characterized by water contact angle measurement:

Use a contact angle analyzer (OCA20 type, Germany) to measure the water static contact angle (CA) at different positions on the treated film surface under ambient humidity and temperature. When the water contact angle is measured, the surface of ^the sample film is selected to be at least 10 Measured at different positions to examine the uniformity of modification.

The water contact angle of the surface of the sample treated by the modification method of the present invention is determined to be 20-35 degrees, and the difference of the water contact angles at different positions is not more than 2 degrees.

Compared with the general homogeneous surface graft polymerization system, the method of the present invention realizes the surface modification of the polymer film material by selecting an appropriate reaction solution to carry out heterogeneous ultraviolet light graft polymerization, and its advantages are:

1) A uniformly modified polymer surface can be obtained at a low grafting rate;

2) The modification effect is long-acting;

3) A continuous post-processing method can be adopted, and the processing procedure is simple and easy.

The present invention will be further described below in conjunction with embodiment.

Description of drawings:

Fig. 1 is the scanning electron micrograph of embodiment 1 graft film surface;

Fig. 2 is comparative example 1 graft film surface scanning electron micrograph;

Fig. 3 is embodiment 4 graft film surface scanning electron micrographs;

Fig. 4 is comparative example 4 graft film surface scanning electron micrographs;

Fig. 5 is the surface scanning electron micrograph of embodiment 5 grafted film;

Fig. 6 is comparative example 5 graft film surface scanning electron micrographs;

For the contents represented in the above drawings, please refer to the specific implementation details.

Detailed ways:

Example 1

The hydrogen abstraction photoinitiator benzophenone is dissolved in ethanol, the polar monomer acrylamide is dissolved in water, and then the above two are mixed to form a reaction solution. The concentration of the polar monomer in the reaction solution is 25wt%. The concentration of the hydrogen abstraction initiator is 0.8wt%, and the ratio of ethanol/water in the mixed solvent is 1:1wt%. Use a coated wire rod to evenly coat the prepared reaction solution on the biaxially oriented polypropylene (BOPP) film, the coating amount is 15g/m ² , cover the polyethylene film with a thickness of 0.1mm, and then place it in a 1000W high-pressure mercury Under the lamp, irradiate for 20 seconds. The distance between the BOPP film to be treated and the 1000W high-pressure mercury lamp is 20cm, and the light intensity is 65W/m ² (λ=365nm). The cover film and the treatment film were separated, and the treatment film was washed with water and dried. The grafting rate of the treated BOPP film was determined to be 0.11%, and the water contact angle of 10 test points on the surface of the 5× ^5cm2 film was 25±2 degrees. The surface water contact angle of the treated surface did not change after being exposed to the air for 8 months.

Comparative Example 1

Dissolve the hydrogen abstraction photoinitiator benzophenone in a small amount of ethanol, dissolve the polar monomer acrylamide in water, and then add the photoinitiator solution to the monomer solution to form a reaction solution. The ethanol content in the solvent is 1 wt%. The polar monomer concentration in the reaction solution is 25%, and the hydrogen abstraction type initiator concentration is 0.8wt%. The prepared reaction solution is evenly coated on the biaxially oriented polypropylene (BOPP) film by using a coating wire rod, and the The amount of cloth is 15g/m ² , covered with a polyethylene film with a thickness of 0.1 mm, and then placed under a 1000W high-pressure mercury lamp for 20 seconds of irradiation. The distance between the BOPP film to be treated and the 1000W high-pressure mercury lamp is 20cm, and the light intensity is 65W/m ² (λ=365nm). The cover film and the treatment film were separated, and the treatment film was washed with water and dried. The grafting rate of the treated BOPP film was determined to be 0.6%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 45±25 degrees. The scanning electron micrographs of the surface of the grafted film obtained in Example 1 and Comparative Example 1 are shown in FIG. 1 .

Example 2

The method for preparing hydroxyethyl acrylate and thioxanthone butanol, water (butanol/water is 2: 1wt%) mixed solution according to the method of Example 1, the polar monomer concentration in the reaction solution is 23wt%, hydrogen abstraction type The initiator concentration was 2.3 wt%. Use a coating wire rod to evenly coat the prepared reaction solution on a polyethylene terephthalate (PET) film (without using a cover film), the coating amount is 10g/ ^m2 , and then place it under 1000W high pressure Irradiate for 20 seconds under a mercury lamp. The distance between the PET film to be treated and the high-pressure mercury lamp is 25 cm, the light intensity is 59 W/m ² (λ=365 nm), and the treated film is washed with water and dried. The grafting rate of the treated PET film was determined to be 0.1%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 22±1°, and the surface water contact angle did not change after the treated surface was exposed to the air for 10 months.

Example 3

The method for preparing N-vinylpyrrolidone and benzophenone in acetone, water (acetone/water is 3: 2wt%) mixed solution according to the method of Example 1, the concentration of polar monomers in the reaction solution is 15wt%, hydrogen abstraction type trigger The agent concentration is 0.75wt%. Use a coating wire rod to evenly coat the prepared reaction solution on a polyethylene terephthalate (PET) film, the coating amount is 12g/ ^m2 , and cover the biaxially oriented polypropylene film with a thickness of 0.02 mm , and then placed under a 20W low-pressure mercury lamp for 1 minute. The distance between the PET film to be treated and the low-pressure mercury lamp is 1 cm, and the light intensity is 10 W/m ² (λ=254 nm). The cover film and the treatment film were separated, and the treatment film was washed with water and dried. The grafting rate of the treated PET film was determined to be 0.18%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 24±2 degrees. The treated surface was exposed to the air for 12 months, and the surface water contact angle did not change.

Example 4

The method for preparing acrylonitrile and thioxanthone butanone, water (butanone/water is 4: 1wt%) mixed solution according to the method of Example 1, the polar monomer concentration in the reaction solution is 8wt%, hydrogen abstraction type initiator The concentration is 0.3 wt%. The prepared reaction solution was uniformly coated on polyethylene (PE) film (without covering film) by using a coating wire rod, the coating amount was 8g/m ² ; and then placed under a 1000W high-pressure mercury lamp for 50 seconds of irradiation. The distance between the PE film to be treated and the high-pressure mercury lamp is 30 cm, and the light intensity is 45 W/m ² (λ=365 nm). The treated PE film was washed with water and dried. The grafting rate of the PE film was determined to be 0.05%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 26±1°, and the surface water contact angle did not change after the treated surface was exposed to the air for 6 months.

Comparative Example 4

Dissolve the hydrogen abstraction photoinitiator thioxanthone in a small amount of butanone, dissolve the polar monomer acrylonitrile in water, then add the photoinitiator solution to the monomer solution to form a reaction solution, and the butanone in the solvent The content is 3wt%. The concentration of the polar monomer in the reaction liquid is 8wt%, and the concentration of the hydrogen abstraction type initiator is 0.3wt%. The prepared reaction solution was uniformly coated on polyethylene (PE) film (without cover film) with a coating wire rod, the coating amount was 8g/m ² , and then placed under a 1000W high pressure mercury lamp for 50 seconds irradiation. The distance between the PE film to be treated and the high-pressure mercury lamp is 30 cm, and the light intensity is 45 W/m ² (λ=365 nm). The treated PE film was washed with water and dried. The grafting rate of the PE film after the measurement was 0.5%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 35±15 degrees. The scanning electron micrographs of the surface of the grafted film obtained in Example 4 and Comparative Example 4 are shown in FIG. 2 .

Example 5

The method for preparing methacrylic acid, acrylonitrile, acrylamide (1: 3: 4wt%) and ethanol, butanol, water (2: 1:2wt%) mixed solution, the concentration of the polar monomer in the reaction solution is 15wt%, and the concentration of the hydrogen abstraction type initiator is 0.9wt%. Continuously and evenly coat the prepared reaction solution on the polyethylene (PE) film on the UV curing machine, the coating amount is 12g/m ² , and pass through 40 side-by-side 20W low-pressure mercury lamps at a line speed of 15m/min For irradiation, the distance between the PE film to be treated and the low-pressure mercury lamp is 1 cm, and the light intensity is 10 W/m ² (λ=254 nm). Continuous washing in-line with water and drying results in a continuous coiled product. The grafting rate of the treated PE film was determined to be 0.14%, and the water contact angle of 10 test points on the surface of the 5×5cm ^film was 30±2 degrees, and the surface water contact angle did not change after the treated surface was exposed to the air for 8 months.

Comparative Example 5

The hydrogen abstraction photoinitiator thioxanthone, benzophenone (1: 1wt%) was dissolved in a small amount of ethanol, and the polar monomer methacrylic acid, acrylonitrile, acrylamide (1: 3: 4wt%) It is dissolved in water, and then the photoinitiator solution is added into the monomer solution to form a reaction solution, and the content of ethanol in the solvent is 2wt%. The concentration of the polar monomer in the reaction solution is 15 wt%, and the weight usage of the hydrogen abstraction type initiator is 0.9 wt%. Continuously and evenly coat the prepared reaction solution on the polyethylene (PE) film on the UV curing machine, the coating amount is 12g/m ² , and pass through 40 side-by-side 20W low-pressure mercury lamps at a line speed of 15m/min For irradiation, the distance between the PE film to be treated and the low-pressure mercury lamp is 1 cm, and the light intensity is 10 W/m ² (λ=254 nm). Continuous washing in-line with water and drying results in a continuous coiled product. The grafting ratio of the treated PE film was determined to be 0.3%, and the water contact angle at 10 test points on the surface of the 5×5cm ^film was 55±25 degrees. The scanning electron micrographs of the surface of the grafted film obtained in Example 5 and Comparative Example 5 are shown in FIG. 3 .

Example 6

Prepare the mixed solution of acrylamide, hydroxypropyl acrylate (2: 1wt%) and benzophenone in ethanol, butanol, water (ethanol/butanol/water is 2: 1: 2wt%) according to the method of Example 1, The polar monomer concentration in the reaction solution is 9 wt%, and the hydrogen abstraction type initiator concentration is 1.35 wt%. The prepared reaction solution was continuously and uniformly coated on a polyethylene terephthalate (PET) film on a UV curing machine, and the coating amount was 10 g/m ² . Covered with 0.02 mm thick biaxially stretched polypropylene film, irradiated by 15 side-by-side 20W low-pressure mercury lamps at a linear speed of 1m/min, the distance between the PET film to be treated and the low-pressure mercury lamp is 1cm, and the light intensity is 10W/ m ² (λ=254nm). Continuous washing in-line with water and drying results in a continuous coiled product. The grafting rate of the treated PET film was determined to be 0.22%. The water contact angle of 10 test points on the surface of the 5× ^5cm2 film was 22±2 degrees. The treated surface was exposed to the air for more than 8 months, and the surface water contact angle did not change. .

Example 7

The hydrogen abstraction type initiator is the mixture of thioxanthone and benzophenone (2: 1wt%), and the concentration of the hydrogen abstraction type initiator in the reaction solution is 0.54wt%, and other is the same as embodiment 6, measures the PET film that has been processed. The grafting rate was 0.26%, and the water contact angle of 10 test points on the 5× ^5cm2 film surface was 21±2 degrees. The treated surface was exposed to the air for more than 8 months, and the surface water contact angle did not change.

Example 8

Prepare the mixed solution of N-vinylpyrrolidone, hydroxyethyl acrylate (2: 1wt%) and benzophenone in acetone and water (acetone/water is 1: 1wt%) according to the method of Example 1, polarity in the reaction solution The monomer concentration is 12%, and the hydrogen abstraction initiator concentration is 0.6%. The prepared reaction solution was continuously and uniformly coated on a biaxially oriented polypropylene (BOPP) film on a UV curing machine, with a coating weight of 18 g/m ² . Cover the 0.02mm thick two-way stretched polypropylene film, irradiate through the 1000W high-pressure mercury lamp with the linear speed of 25m/min, the distance between the BOPP film to be treated and the high-pressure mercury lamp is 15cm, and the light intensity is 75W/m ² (λ= 365nm). Continuous washing in-line with water and drying results in a continuous coiled product. The grafting rate of the treated BOPP film was determined to be 0.15%. The water contact angle of 10 test points on the surface of the 5×5cm ^film was 28±2 degrees. The treated surface was exposed to the air for 12 months, and the surface water contact angle did not change.

Example 9

Acetone, butanone, ethanol, water (acetone/butanone/ethanol) of N-vinylpyrrolidone, hydroxyethyl acrylate, methacrylic acid (3: 2: 1wt%) and benzophenone are prepared according to the method of Example 1 /water (1:1:2:3wt%) mixed solution, the concentration of the polar monomer is 12%, and the concentration of the hydrogen abstraction type initiator is 0.4%. The prepared reaction solution was continuously and uniformly coated on a biaxially oriented polypropylene (BOPP) film on a UV curing machine, with a coating weight of 12g/m ² , and irradiated by a 2000W high-pressure mercury lamp at a line speed of 45m/min. The distance between the BOPP film to be treated and the high-pressure mercury lamp is 25 cm, and the light intensity is 63 W/m ² (λ=365 nm). Continuous washing in-line with water and drying results in a continuous coiled product. The grafting rate of the treated BOPP film was determined to be 0.16%, and the water contact angle of 10 test points on the surface of the 5× ^5cm2 film was 30±1 degrees. The treated surface was exposed to the air for 12 months, and the surface water contact angle did not change.

Claims (7)

1. A reaction solution for polymer film modification, comprising the following components: 1) Polar monomers, selected from at least one of acrylic acid and its derivatives, acrylamide and its derivatives, acrylates, N-vinylpyrrolidone or acrylonitrile, and its weight percentage concentration is 1% of the reaction solution 5-30%; 2) hydrogen abstraction type photoinitiator, at least one selected from benzophenone, thioxanthone and its derivatives, anthraquinone or coumarone, its weight percent concentration is 0.1-3 of the reaction solution %; 3) The balance is a mixed solvent, which is composed of water and alcohols and/or ketone organic solvents, wherein the weight percentage of water is 10-60%. 2. The reaction solution for polymer film modification according to claim 1, characterized in that: the acrylic acid and its derivatives described in component 1) are selected from acrylic acid, methacrylic acid; acrylamide and its derivatives The substances are selected from acrylamide, N-methylolacrylamide; the acrylates are selected from methyl acrylate, methyl methacrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate. 3. The reaction solution for polymer film modification according to claim 1, characterized in that: component 3) said alcohols are selected from the group consisting of methanol, ethanol, isopropanol, butanol, ethylene glycol, butanol Diols; ketones are selected from acetone, methyl ethyl ketone, pentanone, cyclohexanone. 4. A method for applying the polymer film modification reaction solution according to any one of claims 1 to 3, comprising the following steps: 1) Preparation of reaction solution: according to the above-mentioned reaction solution component ratio for polymer film modification, polar monomers and hydrogen abstraction photoinitiators are dissolved in a mixed solvent to form a reaction solution; 2) Intermittent treatment of ultraviolet light grafting: use a coating wire rod to evenly coat the prepared reaction solution on the film to be treated, the coating amount of the reaction solution is 5-20g/m ² , and then place it under ultraviolet light ; 3) The photografted film is cleaned with a solvent, and dried to obtain a finished polymer film with a highly hydrophilic surface modification. 5. The application method of polymer film modification reaction solution according to claim 4, characterized in that: step 2) is replaced by ultraviolet light grafting continuous treatment: the film to be treated is treated at a rate of 0.1m/min on the ultraviolet light curing machine The process is carried out continuously at a line speed of ~50m/min. The reaction solution is placed in a storage tank and evenly coated on the film to be treated by a doctor blade or a coating roller, and then irradiated under an ultraviolet lamp. 6. The application method of the polymer film modification reaction solution according to claim 4 or 5, characterized in that: In step 2), the film to be treated is compounded with a cover film with a UV light transmittance higher than 75%. 7. The application method of polymer film modification reaction liquid according to claim 6, characterized in that the covering film is selected from polypropylene film and polyethylene film.

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