An anti-uv high-barrier composite film and a preparation method thereof

Abstract

The application relates to the technical field of polymer films, in particular to an anti-UV high-barrier composite film and a preparation method thereof. The anti-UV high-barrier composite film comprises a polymer film and an anti-UV high-barrier coating liquid coated on the polymer film, the thickness of the polymer film is 50-80 mu m; the anti-UV high-barrier coating liquid comprises the following raw materials in mass fractions: 50-55 parts of polyvinyl alcohol, 1015 parts of ethanol, 1-3 parts of a reaction precursor, 90-100 parts of deionized water, 3-5 parts of rutile titanium dioxide additives, 1-3 parts of dispersible graphene, 0.5-0.8 parts of urea and 0.5-1 part of a coupling agent. The anti-UV high-barrier composite film has excellent oxygen resistance, water resistance and anti-UV performance, and can be widely applied to fields requiring oxygen, moisture and ultraviolet blocking, such as food packaging, photoelectric products and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-molecular films, in particular to an anti-UV high-barrier composite film and a preparation method thereof. BACKGROUND

[0002] In recent years, with the improvement of living standards and the increasing variety of food, people have higher and higher requirements for food packaging materials, the main purpose of which is to prolong the shelf life of food, and thus the packaging materials are required to have high barrier properties. The application of high-barrier packaging materials not only reduces food waste, but also guarantees health and safety.

[0003] Polyvinyl alcohol (PVA) is a water-soluble polymer, has biodegradability, good film-forming property, good brightness, mechanical property, gas barrier property and other advantages. The oxygen barrier property of PVA is even better than that of ethylene / vinyl alcohol copolymer, but the barrier property and anti-UV property of pure PVA film still cannot meet the requirements of high-performance packaging products, which limits the application of PVA to a certain extent. SUMMARY

[0004] The application aims at the deficiencies of the current technology, and provides an anti-UV high-barrier composite film and a preparation method thereof.

[0005] In a first aspect, the application provides an anti-UV high-barrier composite film, as shown in the following technical solution.

[0006] The anti-UV high-barrier composite film comprises a high-molecular film and an anti-UV high-barrier coating liquid coated on the high-molecular film, the thickness of the high-molecular film is 50-80 mu m, and the anti-UV high-barrier coating liquid comprises the following raw materials in mass fraction: 50-55 parts of polyvinyl alcohol, 10-15 parts of ethanol, 1-3 parts of reaction precursor, 90-100 parts of deionized water, 3-5 parts of rutile titanium dioxide additive, 1-3 parts of dispersible graphene, 0.5-0.8 parts of urea and 0.5-1 part of coupling agent.

[0007] By adopting the above technical scheme, in the present application, the components play different roles and have synergies with each other to improve the performance of the anti-UV high-barrier composite film. Polyvinyl alcohol (PVA): as one of the main components of the polymer film, it has good water resistance and mechanical strength, forming the basic skeleton of the film. Ethanol: as a solvent, it is used to dissolve PVA and other raw materials to form a coating liquid. Reaction precursor: the active silicon hydroxyl group of the hydrolysis product of the reaction precursor condenses and crosslinks with the hydroxyl group of PVA during the drying process, improving the barrier performance and anti-UV performance of the coating. Deionized water: as a solvent, it provides the environment required by the reaction precursor. Rutile titanium dioxide additive: through surface chemical design, it effectively combines with dispersible graphene to form a dense structure, improving the oxygen barrier performance and anti-UV performance. Dispersible graphene: it reacts and adsorbs with the rutile titanium dioxide additive and assembles to form a dense structure, improving the oxygen barrier performance and anti-UV performance. Urea and coupling agent: they play a role in adjusting the viscosity and enhancing the adhesion of the coating liquid. Through the above components and their synergies, the anti-UV high-barrier composite film exhibits excellent performance in terms of oxygen barrier, water resistance, and anti-UV performance.

[0008] Preferably, the polymer film is one of a polyester film, a polyurethane film, and a PET film.

[0009] Preferably, the reaction precursor is one of tetraethyl orthosilicate and tetramethyl orthosilicate.

[0010] By adopting the above technical scheme, tetraethyl orthosilicate or tetramethyl orthosilicate is hydrolyzed to produce nanosilica, and the active silicon hydroxyl group of the hydrolysis product of the reaction precursor condenses and crosslinks with the hydroxyl group of PVA during the drying process, improving the barrier performance and anti-UV performance of the coating.

[0011] Preferably, the preparation method of the rutile titanium dioxide additive includes: adding deionized water, mannitol, and modified rutile titanium dioxide into a reactor, ultrasonic dispersion for 25 min, transferring the reactor to a stand with mechanical stirring for stirring, adding sodium ethylenediaminetetraacetate and ethylenediamine into the reactor, increasing the temperature of the reactor to 150-160℃, reacting for 3-5 h, then reducing the temperature to room temperature, transferring the reaction system to a dialysis bag, dialysis for 24 h, transferring the liquid in the dialysis bag to a rotary evaporator, setting the water bath temperature to 75℃, and distilling under reduced pressure until no liquid flows out to obtain the rutile titanium dioxide additive.

[0012] Preferably, the amount ratio of the deionized water, mannitol, modified rutile titanium dioxide, sodium ethylenediaminetetraacetate, and ethylenediamine is 60 mL:90 mL:25 g:15 g:10 mL.

[0013] Preferably, the preparation method of the modified rutile titanium dioxide comprises: adding 25 g of nano-rutile titanium dioxide, 120 mL of ethanol and 25 mL of water into a reactor, ultrasonic dispersion for 50 min, transferring the reactor to a stand with mechanical stirring for stirring, increasing the temperature of the reactor to 55℃, adding 2 g of 3-aminopropyl triethoxysilane into a three-necked flask dropwise, reacting for 2-3 h after the dropwise addition is completed, then filtering, washing the filter cake with ethanol and purified water, and then transferring the filter cake to a drying box with a temperature of 70℃ for vacuum drying to a constant weight before processing to obtain the modified rutile titanium dioxide.

[0014] By adopting the above technical scheme, the 3-aminopropyl triethoxysilane is grafted and modified on the surface of the nano-rutile titanium dioxide by reacting the nano-rutile titanium dioxide with the 3-aminopropyl triethoxysilane to obtain modified silica, and the sodium ethylenediaminetetraacetate and ethylenediamine are reacted with the modified silica to form imino, hydroxyl and carbonyl functional groups on the titanium quantum dots on the surface of the modified rutile titanium dioxide, thereby improving the UV absorption characteristics of the titanium quantum dots, and further improving the anti-UV performance of the anti-UV high-barrier composite film. Moreover, the dispersion and compatibility of the rutile titanium dioxide particles in polyvinyl alcohol are improved by the modification treatment, thereby improving the barrier performance and anti-UV performance of the anti-UV high-barrier composite film.

[0015] Preferably, the preparation method of the dispersible graphene comprises: dissolving 10 g of graphene oxide in 100 g of an ethanol-water solution with a volume ratio of 1:1, adding zirconium balls with a diameter of 0.1 mm, adjusting the pH value of the solution to 9, dropwise adding 30 mL of 3-ureidopropyl trimethoxysilane with a concentration of 10 g / L, ball milling for 120 min, then centrifuging to obtain a precipitate, washing the precipitate with ethanol for three times, and drying to obtain the dispersible graphene.

[0016] By adopting the above technical scheme, the modified rutile titanium dioxide additive is effectively combined with the dispersible graphene through surface chemical design, and a dense "brick-wall" structure is formed through reaction adsorption and assembly, so that the small molecule penetration path is extremely tortuous, and the prepared anti-UV high-barrier composite film has excellent oxygen barrier performance, water resistance and anti-ultraviolet performance.

[0017] Preferably, the coupling agent is a combination of vinyl trimethoxysilane, γ-glycidoxypropyl trimethoxysilane and 3-ureidopropyl trimethoxysilane in a mass ratio of 5:1-3:3-5.

[0018] By adopting the technical scheme, in the application, the coupling agents vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane have the following effects and synergies in a mass ratio of 5:1-3:3-5: the vinyltrimethoxysilane is a coupling agent, which can improve the compatibility and adhesion between the modified silica and the polymer film and other components, thereby enhancing the overall performance of the composite film. The γ-glycidoxypropyltrimethoxysilane has good hydrophilicity and the ability to improve the dispersibility of the nanorutile titanium dioxide and the dispersible graphene, which can enhance the compatibility between the modified silica and the dispersible graphene and the water-soluble components, and improve the stability of the coating liquid. The 3-ureidopropyltrimethoxysilane can interact with the nanorutile titanium dioxide and the dispersible graphene in the reaction to form a stable interface structure, thereby improving the compatibility and dispersibility of the modified silica, the nanorutile titanium dioxide and the dispersible graphene. Through the above effects and synergies of the coupling agents, the compatibility and adhesion between the nanosilica and the polymer film, the modified rutile titanium dioxide, the dispersible graphene, polyvinyl alcohol and other components can be enhanced, and the overall performance and UV resistance of the UV-resistant high-barrier composite film can be improved.

[0019] Preferably, the preparation method of the UV-resistant high-barrier coating liquid adopts the raw materials of the above-mentioned UV-resistant high-barrier composite film, and includes the following steps: adding polyvinyl alcohol, ethanol, reaction precursors, deionized water, rutile titanium dioxide additives, dispersible graphene, urea and coupling agents into a reactor in the order of mass fraction, stirring at a stirring speed of 600 rpm, then heating to 95℃, and then refluxing for 2 hours, and then naturally cooling to 50℃, and then continuing to reflux for 5 hours, and then naturally cooling to room temperature, to obtain the UV-resistant high-barrier coating liquid.

[0020] In a second aspect, the application provides a preparation method of a UV-resistant high-barrier composite film, as shown in the following technical scheme:

[0021] The preparation method of the UV-resistant high-barrier composite film adopts the raw materials of the above-mentioned UV-resistant high-barrier composite film, and the preparation method includes the following steps:

[0022] S1: subjecting the polymer film to be coated to plasma treatment, and the process conditions of the plasma treatment are as follows: oxygen pressure of 50 Pa, plasma power of 3000 W, and time of 0.3-0.5 min;

[0023] S2: After the anti-UV high-barrier coating solution is coated on the plasma-treated polymer film, the coating is cured by first increasing the temperature in a gradient and then decreasing the temperature in a gradient, to obtain an anti-UV high-barrier composite film, the coating speed is 150-180 m / min; the thickness of the anti-UV high-barrier coating solution layer after curing is 10-20 μm; when the temperature is increased in a gradient and then decreased in a gradient for curing, the temperature settings are 70±2℃, 85±2℃, 105±2℃, 120±2℃, 90±2℃, 80±2℃.

[0024] In summary, the beneficial technical effects of the present application are:

[0025] 1. Excellent oxygen barrier property: By adding modified titanium dioxide and dispersible graphene to the polymer film, a dense "brick-wall" structure is formed, effectively preventing the penetration of oxygen and improving the oxygen barrier performance of the film.

[0026] 2. Excellent water barrier property: By condensation cross-linking reaction of the reaction precursor and addition of modified titanium dioxide, the water barrier property of the coating is improved, effectively preventing the penetration of water.

[0027] 3. Improved anti-UV performance: By modifying titanium quantum dots on the surface of nano-titanium dioxide, the UV absorption properties of titanium quantum dots are enhanced, thereby improving the anti-UV performance of the anti-UV high-barrier composite film.

[0028] 4. Good dispersibility and compatibility: By modifying titanium dioxide particles, the dispersibility and compatibility of the particles in polyvinyl alcohol are improved, thereby further improving the barrier performance and anti-UV performance of the anti-UV high-barrier composite film.

[0029] 5. Excellent anti-UV performance: By combining modified titanium dioxide additives and dispersible graphene, the small molecule penetration path of the film becomes extremely tortuous, effectively blocking the penetration of ultraviolet light, and improving the anti-UV performance of the anti-UV high-barrier composite film. DETAILED DESCRIPTION

[0030] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0031] Example 1

[0032] The application discloses an anti-UV high-barrier composite film, which comprises a high polymer film and an anti-UV high-barrier coating liquid coated on the high polymer film, wherein the thickness of the high polymer film is 50 microns; the anti-UV high-barrier coating liquid comprises the following raw materials in mass fraction: 50 parts of polyvinyl alcohol, 10 parts of ethanol, 1 part of ethyl silicate, 90 parts of deionized water, 3 parts of rutile titanium dioxide additive, 1 part of dispersible graphene, 0.5 part of urea and 0.5 part of coupling agent; the high polymer film is a polyester film; and the coupling agent is a composition of vinyl trimethoxysilane, gamma-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:1:3.

[0033] The preparation method of the rutile titanium dioxide additive comprises the following steps: adding 60 mL of deionized water, 90 mL of mannitol and 25 g of modified rutile titanium dioxide into a reactor, ultrasonic dispersing for 25 min, transferring the reactor to a stand with mechanical stirring to stir, adding 15 g of sodium ethylenediaminetetraacetate and 10 mL of ethylenediamine into the reactor, increasing the temperature of the reactor to 150 DEG C, reacting for 3 h, then reducing the temperature to room temperature, transferring the reaction system into a dialysis bag, dialyzing for 24 h, transferring the liquid in the dialysis bag into a rotary evaporator, setting the water bath temperature to 75 DEG C, and performing reduced pressure distillation until no liquid flows out to obtain the rutile titanium dioxide additive.

[0034] The preparation method of the modified rutile titanium dioxide comprises the following steps: adding 25 g of nano-rutile titanium dioxide, 120 mL of ethanol and 25 mL of water into a reactor, ultrasonic dispersing for 50 min, transferring the reactor to a stand with mechanical stirring to stir, increasing the temperature of the reactor to 55 DEG C, adding 2 g of 3-aminopropyltriethoxysilane dropwise into a three-necked flask, reacting for 2 h after the dropwise addition is completed, then performing suction filtration, washing the filter cake with ethanol and purified water, transferring the filter cake into a drying box with a temperature of 70 DEG C, vacuum drying the filter cake until the weight is constant, and then performing treatment to obtain the modified rutile titanium dioxide.

[0035] The preparation method of the dispersible graphene comprises the following steps: dissolving 10 g of graphene oxide in 100 g of an ethanol water solution with a volume ratio of 1:1, adding zirconium balls with a diameter of 0.1 mm, adjusting the pH value of the solution to 9, adding 30 mL of 3-ureidopropyltrimethoxysilane with a concentration of 10 g / L dropwise, performing ball milling for 120 min, then performing centrifugation to obtain a precipitate, washing the precipitate with ethanol for three times, and drying to obtain the dispersible graphene.

[0036] The preparation method of the anti-UV high-barrier coating solution comprises the following steps: adding polyvinyl alcohol, ethanol, tetraethyl orthosilicate, deionized water, rutile titanium dioxide additive, dispersible graphene, urea and coupling agent into a reactor in the order of mass fraction, stirring at a stirring speed of 600 rpm, then heating to 95 DEG C, and then naturally cooling to 50 DEG C, continuing to heat to reflux for 5 hours, and naturally cooling to room temperature to obtain the anti-UV high-barrier coating solution.

[0037] The preparation method of the anti-UV high-barrier composite film comprises the following steps:

[0038] S1: the high molecular film to be coated is subjected to plasma treatment, and the process conditions of the plasma treatment are as follows: oxygen pressure 50 Pa, plasma power 3000 W, and time 0.3 min;

[0039] S2: the anti-UV high-barrier coating solution is coated on the high molecular film subjected to plasma treatment, and then solidified by the way of gradient heating and then gradient cooling to obtain the anti-UV high-barrier composite film, wherein the coating speed is 150 m / min, the thickness of the anti-UV high-barrier coating solution layer after solidification is 10 microns, and the temperature setting during the solidification by the way of gradient heating and then gradient cooling is 68 DEG C, 83 DEG C, 103 DEG C, 118 DEG C, 90 DEG C ± 2 DEG C and 78 DEG C in sequence.

[0040] Example 2

[0041] An anti-UV high-barrier composite film comprises a high molecular film and an anti-UV high-barrier coating solution coated on the high molecular film, wherein the thickness of the high molecular film is 80 microns, the anti-UV high-barrier coating solution comprises the following mass fractions of raw materials: polyvinyl alcohol 55 parts, ethanol 15 parts, tetraethyl orthosilicate 3 parts, deionized water 100 parts, rutile titanium dioxide additive 5 parts, dispersible graphene 3 parts, urea 0.8 parts and coupling agent 1 part, the high molecular film is one of a polyester film, a polyurethane film and a PET film, and the coupling agent is a composition of vinyl trimethoxysilane, gamma-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:3:5.

[0042] The preparation method of the rutile titanium dioxide additive comprises the following steps: 60 mL of deionized water, 90 mL of mannitol and 25 g of modified rutile titanium dioxide are added into a reactor, ultrasonic dispersion is performed for 25 min, the reactor is transferred to a stand with mechanical stirring for stirring, 15 g of sodium ethylenediaminetetraacetate and 10 mL of ethylenediamine are added into the reactor, the temperature of the reactor is increased to 160 DEG C, reaction is performed for 5 h, then the temperature is decreased to room temperature, the reaction system is transferred to a dialysis bag, dialysis is performed for 24 h, the liquid in the dialysis bag is transferred to a rotary evaporator, the temperature of a water bath is set to 75 DEG C, and the liquid is distilled under reduced pressure until no liquid flows out, so that the rutile titanium dioxide additive is obtained.

[0043] The preparation method of the modified rutile titanium dioxide comprises the following steps: 25 g of nano-rutile titanium dioxide, 120 mL of ethanol and 25 mL of water are added into a reactor, ultrasonic dispersion is performed for 50 min, the reactor is transferred to a stand with mechanical stirring for stirring, the temperature of the reactor is increased to 55 DEG C, 2 g of 3-aminopropyltriethoxysilane is added dropwise into a three-necked flask, after the dropwise addition is completed, reaction is performed for 3 h, then filtration is performed, the filter cake is washed with ethanol and purified water, the filter cake is transferred into a drying box with a temperature of 70 DEG C, vacuum drying is performed until the weight is constant, and then the modified rutile titanium dioxide is obtained.

[0044] The preparation method of the dispersible graphene comprises the following steps: 10 g of graphene oxide is dissolved in 100 g of an ethanol water solution with a volume ratio of 1:1, zirconium balls with a diameter of 0.1 mm are added, the pH value of the solution is adjusted to 9, 30 mL of 3-ureidopropyltrimethoxysilane with a concentration of 10 g / L is added drop by drop, ball milling is performed for 120 min, then the precipitate is obtained through centrifugation, the precipitate is washed with ethanol for three times, and the dispersible graphene is obtained after drying.

[0045] The preparation method of the anti-UV high-barrier coating liquid comprises the following steps: according to mass fractions, polyvinyl alcohol, ethanol, methyl silicate, deionized water, rutile titanium dioxide additive, dispersible graphene, urea and a coupling agent are sequentially added into a reactor, stirring is performed, the stirring speed is 600 rpm, then heating is performed until the temperature reaches 95 DEG C, and then the solution is refluxed for 2 hours, then the temperature is naturally decreased to 50 DEG C, the solution is continuously refluxed for 5 hours, the temperature is naturally cooled to room temperature, and finally the anti-UV high-barrier coating liquid is obtained.

[0046] The preparation method of an anti-UV high-barrier composite film comprises the following steps: the raw materials of the anti-UV high-barrier composite film are used.

[0047] S1: the polymer film to be coated is subjected to plasma treatment, and the process conditions of the plasma treatment are as follows: the oxygen pressure is 50 Pa, the plasma power is 3000 W, and the time is 0.5 min;

[0048] S2: After the anti-UV high-barrier coating liquid is coated on the plasma-treated polymer film, the coating liquid is cured by the way of first gradient temperature rising and then gradient temperature falling, to obtain an anti-UV high-barrier composite film, the coating speed is 180 m / min; the thickness of the anti-UV high-barrier coating liquid after curing is 20 μm; when the coating liquid is cured by the way of first gradient temperature rising and then gradient temperature falling, the temperature setting is 72℃, 87℃, 107℃, 122℃, 92℃ and 82℃ in turn.

[0049] Example 3

[0050] An anti-UV high-barrier composite film, comprising a polymer film and an anti-UV high-barrier coating liquid coated on the polymer film, the thickness of the polymer film is 70 μm; the anti-UV high-barrier coating liquid comprises the following raw materials in mass fraction: polyvinyl alcohol 53 parts, ethanol 13 parts, tetraethyl orthosilicate 2 parts, deionized water 95 parts, rutile titanium dioxide additive 4 parts, dispersible graphene 2 parts, urea 0.6 parts, coupling agent 0.7 parts, the polymer film is one of a polyester film, a polyurethane film and a PET film, and the coupling agent is a composition of vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:2:4.

[0051] The preparation method of the rutile titanium dioxide additive comprises the following steps: 60 mL of deionized water, 90 mL of mannitol and 25 g of modified rutile titanium dioxide are added into a reactor, ultrasonic dispersion is performed for 25 min, the reactor is transferred to a stand with mechanical stirring for stirring, 15 g of sodium ethylenediaminetetraacetate and 10 mL of ethylenediamine are added into the reactor, the temperature of the reactor is increased to 155℃, reaction is performed for 4 h, then the temperature is decreased to room temperature, the reaction system is transferred to a dialysis bag, dialysis is performed for 24 h, the liquid in the dialysis bag is transferred to a rotary evaporator, the temperature of a water bath is set to 75℃, and the liquid is distilled under reduced pressure until no liquid flows out, to obtain the rutile titanium dioxide additive.

[0052] The preparation method of the modified rutile titanium dioxide comprises the following steps: 25 g of nano-rutile titanium dioxide, 120 mL of ethanol and 25 mL of water are added into a reactor, ultrasonic dispersion is performed for 50 min, the reactor is transferred to a stand with mechanical stirring for stirring, the temperature of the reactor is increased to 55℃, 2 g of 3-aminopropyltriethoxysilane is added dropwise into a three-necked flask, after the dropwise addition is completed, reaction is performed for 2.5 h, then filtration is performed, the filter cake is washed with ethanol and purified water, the filter cake is transferred into a drying box with a temperature of 70℃ for vacuum drying until the weight is constant, and then the filter cake is treated, to obtain the modified rutile titanium dioxide.

[0053] The preparation method of the dispersible graphene comprises the following steps: 10g of graphene oxide is dissolved in 100g of an ethanol aqueous solution with a volume ratio of 1:1, 0.1mm-diameter zirconium balls are added, the pH value of the solution is adjusted to 9, 30mL of 3-ureidopropyl trimethoxysilane with a concentration of 10g / L is added drop by drop, ball milling is performed for 120min, then the precipitate is obtained through centrifugation, the precipitate is washed with ethanol for three times, and the dispersible graphene is obtained after drying.

[0054] The preparation method of the anti-UV high-barrier coating solution comprises the following steps: polyvinyl alcohol, ethanol, tetraethyl orthosilicate, deionized water, rutile titanium dioxide additive, dispersible graphene, urea and a coupling agent are sequentially added into a reactor according to mass fractions, stirring is performed at a stirring speed of 600rpm, then heating is performed to 95℃, and then the solution is kept in reflux for 2 hours, then the solution is naturally cooled to 50℃, and then the solution is kept in reflux for 5 hours, and then the solution is naturally cooled to room temperature, so that the anti-UV high-barrier coating solution is obtained.

[0055] The preparation method of the anti-UV high-barrier composite film comprises the following steps:

[0056] S1: the polymer film to be coated is subjected to plasma treatment, and the process conditions of the plasma treatment are as follows: the oxygen pressure is 50Pa, the plasma power is 3000W, and the time is 0.4min;

[0057] S2: the anti-UV high-barrier coating solution is coated on the polymer film subjected to the plasma treatment, and then the coating is subjected to solidification in the mode of gradient temperature rising and then gradient temperature falling, so that the anti-UV high-barrier composite film is obtained, the coating speed is 160m / min, the thickness of the anti-UV high-barrier coating solution layer after solidification is 15μm, and the temperature setting during the solidification in the mode of gradient temperature rising and then gradient temperature falling is as follows: 70℃, 85℃, 105℃, 120℃, 90℃ and 80℃.

[0058] Comparative Example 1

[0059] The same as in Example 3, except that an equal amount of polyvinyl alcohol is used instead of tetraethyl orthosilicate.

[0060] Comparative Example 2

[0061] The same as in Example 3, except that an equal amount of unmodified rutile titanium dioxide is used instead of the rutile titanium dioxide additive.

[0062] Comparative Example 3

[0063] The same as in Example 3, except that an equal amount of unmodified graphene oxide is used instead of the dispersible graphene.

[0064] Comparative Example 4

[0065] The same as example 3, except that equal amount of vinyltrimethoxysilane was used instead of the coupling agent being a composition of vinyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:2:4.

[0066] Comparative Example 5

[0067] The same as example 3, except that equal amount of gamma-glycidoxypropyltrimethoxysilane was used instead of the coupling agent being a composition of vinyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:2:4.

[0068] Comparative Example 6

[0069] The same as example 3, except that equal amount of 3-ureidopropyltrimethoxysilane was used instead of the coupling agent being a composition of vinyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane in a mass ratio of 5:2:4.

[0070] Performance Test

[0071] The UV resistant high barrier composite films prepared in example 1-3 and comparative example 1-6 were sampled respectively and tested, and the test results are shown in table 1.

[0072] UV resistant performance: yellowing value was tested by xenon lamp aging test for 2000h according to standard IEC TS 62788-2;

[0073] Oxygen transmission rate: tested according to the method of GB / T1038;

[0074] Water vapor transmission rate: tested according to the method of GB / T1037.

[0075] Table 1

[0076]

[0077]

[0078] From table 1, it can be seen that the UV resistant high barrier composite films prepared in example 1-3 have excellent oxygen barrier property, water barrier property and UV resistant performance.

[0079] From table 1, it can be seen that the performance comparison analysis of the UV resistant high barrier composite films prepared in example 3 and comparative example 1, it can be known that the application utilizes the active silicon hydroxyl of the hydrolysis product of the reaction precursor and the hydroxyl of PVA to condense and crosslink in the drying process, which improves the barrier property and UV resistant performance of the coating.

[0080] From the table 1, comparative analysis of the performance of the anti-UV high-barrier composite film prepared by example 3 and comparative example 2 can be known that, by reacting the nano-rutile titanium dioxide with 3-aminopropyl triethoxysilane, the 3-aminopropyl triethoxysilane is grafted and modified on the surface of the nano-rutile titanium dioxide, the modified silicon dioxide is obtained, the modified silicon dioxide is reacted with sodium ethylenediaminetetraacetate and ethylenediamine, and the imino, hydroxyl and carbonyl functional groups modified by the titanium quantum dots on the surface of the modified rutile titanium dioxide are formed on the rutile titanium dioxide, the UV absorption characteristics of the titanium quantum dots are improved, and then the anti-UV performance of the anti-UV high-barrier composite film is improved, and the dispersion and compatibility of the rutile titanium dioxide particles in the polyvinyl alcohol are improved, and then the barrier performance and anti-UV performance of the anti-UV high-barrier composite film are improved.

[0081] From the table 1, comparative analysis of the performance of the anti-UV high-barrier composite film prepared by example 3 and comparative example 3 can be known that, by modifying the graphene oxide and effectively combining the modified rutile titanium dioxide additive with the dispersible graphene through surface chemical design, a dense "brick-wall" structure is formed through reaction adsorption and assembly, the small molecule penetration path is extremely tortuous, and the prepared anti-UV high-barrier composite film has excellent oxygen barrier performance, water resistance and anti-ultraviolet performance.

[0082] From the table 1, comparative analysis of the performance of the anti-UV high-barrier composite film prepared by example 3 and comparative examples 4-6 can be known that, by using the coupling agent as vinyl trimethoxysilane, γ-glycidyl ether oxypropyl trimethoxysilane and 3-urea propyl trimethoxysilane in a mass ratio of 5:2:4, the synergistic effect among the vinyl trimethoxysilane, the γ-glycidyl ether oxypropyl trimethoxysilane and the 3-urea propyl trimethoxysilane is utilized, and the oxygen barrier performance, water resistance and anti-ultraviolet performance of the anti-UV high-barrier composite film are further improved.

[0083] The above examples are only used to explain the technical solutions of the present application but not to limit it, although the above examples have been specifically described, the related technicians should understand that the specific embodiments of the present application can be modified or replaced by the equivalent, without departing from the spirit and scope of the present application, any modification and equivalent replacement should be covered in the protection scope of the present application.

Claims

1. A UV-resistant high-barrier composite film, characterized in that, The invention comprises a polymer film and an anti-UV high-barrier coating solution coated on the polymer film, wherein the thickness of the polymer film is 50-80 μm; the anti-UV high-barrier coating solution comprises the following raw materials in parts by weight: 50-55 parts polyvinyl alcohol, 10-15 parts ethanol, 1-3 parts reaction precursor, 90-100 parts deionized water, 3-5 parts rutile titanium dioxide additive, 1-3 parts dispersible graphene, 0.5-0.8 parts urea, and 0.5-1 parts coupling agent; The reaction precursor is one of tetraethyl orthosilicate and methyl orthosilicate; The preparation method of the rutile titanium dioxide additive includes: adding deionized water, mannitol, and modified nano-rutile titanium dioxide into a reactor, ultrasonically dispersing for 25 min, transferring the reactor to an iron stand with mechanical stirring, adding sodium ethylenediaminetetraacetate and ethylenediamine to the reactor, raising the reactor temperature to 150-160℃, reacting for 3-5 h, then lowering the temperature to room temperature, transferring the reaction system to a dialysis bag, dialyzing for 24 h, transferring the liquid in the dialysis bag to a rotary evaporator, setting the water bath temperature to 75℃, and distilling under reduced pressure until no liquid is obtained. The liquid flows out, yielding rutile titanium dioxide additive; the ratio of deionized water, mannitol, modified rutile titanium dioxide, sodium ethylenediaminetetraacetate, and ethylenediamine is 60mL:90mL:25g:15g:10mL; the preparation method of the modified rutile titanium dioxide includes: adding 25g of nano-rutile titanium dioxide, 120mL of ethanol, and 25mL of water to a reactor, ultrasonically dispersing for 50min, transferring the reactor to an iron stand with mechanical stirring, stirring, raising the reactor temperature to 55℃, adding 2g of 3-aminopropyltriethoxysilane dropwise to a three-necked flask, reacting for 2-3h after the addition is complete, then filtering, washing the filter cake with ethanol and purified water, transferring the filter cake to a drying oven at 70℃ and vacuum drying to constant weight, and then processing to obtain modified rutile titanium dioxide; The method for preparing the dispersible graphene includes: dissolving 10g of graphene oxide in 100g of an ethanol aqueous solution with a volume ratio of 1:1, adding zirconium balls with a diameter of 0.1mm, adjusting the pH of the solution to 9, adding 30mL of 3-ureapropyltrimethoxysilane with a concentration of 10g / L dropwise, ball milling for 120min, then centrifuging to collect the precipitate, washing it three times with ethanol, and drying it to obtain the dispersible graphene. The coupling agent is a composition of vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and 3-ureapropyltrimethoxysilane in a mass ratio of 5:1-3:3-5.

2. The UV-resistant high-barrier composite film according to claim 1, characterized in that, The polymer film is one of polyester film, polyurethane film and PET film.

3. The UV-resistant high-barrier composite film according to claim 1, characterized in that, The preparation method of the UV-resistant high-barrier coating liquid includes: adding polyvinyl alcohol, ethanol, reaction precursor, deionized water, rutile titanium dioxide additive, dispersible graphene, urea and coupling agent into a reactor in the following proportions by mass: stirring at a stirring speed of 600 rpm; heating to 95°C and refluxing for 2 hours; then cooling naturally to 50°C and continuing to reflux for 5 hours; and finally cooling naturally to room temperature to obtain the UV-resistant high-barrier coating liquid.

4. A method for preparing a UV-resistant high-barrier composite film as described in any one of claims 1-2, characterized in that, Includes the following steps: S1: The polymer film to be coated is subjected to plasma treatment. The plasma treatment process conditions are: oxygen pressure 50Pa, plasma power supply power 3000W, and time 0.3-0.5min. S2: After coating the UV-resistant high-barrier coating liquid onto the plasma-treated polymer film, it is cured by first increasing the temperature and then decreasing the temperature to obtain a UV-resistant high-barrier composite film. The coating speed is 150-180 m / min. The thickness of the UV-resistant high-barrier coating liquid layer after curing is 10-20 μm. The temperature settings for the gradient heating and then gradient cooling curing are as follows: 70±2℃, 85±2℃, 105±2℃, 120±2℃, 90±2℃, and 80±2℃.

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