Printable OPP (Oriented Polypropylene) glazing film and preparation process thereof

Abstract

The invention relates to the technical field of glazing films, in particular to a printable OPP glazing film and a preparation process thereof. The preparation method comprises the following steps: preparing an isocyanato-terminated polyurethane prepolymer, copolymerizing with methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and double-bond-containing silicon dioxide to form an interpenetrating network structure, adding triethylamine for neutralization, and preparing a coating solution by combining the effects of a plurality of assistants; carrying out corona treatment on the polypropylene film to obtain a corona polypropylene film; and coating a corona surface of a corona polypropylene film with the coating liquid, and drying to obtain the printable OPP glazing film. The printable OPP glazing film prepared by the invention has excellent hydrophobic performance, the adhesive force between ink and a coating layer is remarkably improved, and meanwhile, the firmness between the coating layer and a polypropylene film layer is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of glazing films, in particular to a printable OPP glazing film and a preparation process thereof. Background Art

[0002] OPP varnishing film is made primarily from polypropylene through uniaxial or biaxial stretching processes. It boasts high transparency, gloss, mechanical strength, heat resistance, and chemical stability. Printable OPP varnishing film is a special surface treatment or coating process applied to ordinary OPP film, resulting in excellent printability and the ability to withstand ink printing while maintaining the film's original properties.

[0003] In the traditional OPP glazing process, the coating typically contains large amounts of organic solvents, such as toluene and xylene, which evaporate into the air during the production process, causing environmental pollution and posing a risk to human health. Furthermore, some OPP glazing films lack ideal abrasion and scratch resistance, leading to surface wear and scratching during the use of printed materials, affecting their appearance and lifespan. Furthermore, some glazing films lack sufficient water and chemical resistance, causing fading, discoloration, and blistering when exposed to water, oil, acids, and alkalis, resulting in a decrease in the quality of printed materials.

[0004] Therefore, we propose a printable OPP glazing film and its preparation process. Summary of the Invention

[0005] The object of the present invention is to provide a printable OPP glazing film and a preparation process thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions: A process for preparing a printable OPP glazing film comprises the following steps: Step S1: vacuum dehydrating the polyether polyol at 110-120° C. for 2-3 hours, cooling to 60-70° C., adding isophorone diisocyanate and dibutyltin dilaurate under nitrogen protection, mixing uniformly, reacting for 1-3 hours, adding 2,2-dihydroxymethylbutyric acid and modified hyperbranched fluoropolymer, and reacting for 3-5 hours to obtain a polyurethane prepolymer; Mix the emulsifier and deionized water evenly, add methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and double-bonded silica and mix evenly, add pre-emulsification for 0.5-1.5h to obtain pre-emulsified monomer; Step S2: Mix the polyurethane prepolymer, pre-emulsified monomer and deionized water, heat to 70-80°C, add ammonium persulfate aqueous solution dropwise for 1-2 hours, react for 2-4 hours, continue to heat to 85-90°C, add hydroxypropyl methacrylate, react for 1-3 hours; cool to 30-40°C, add triethylamine for neutralization, add defoamer, leveling agent and adhesion promoter, mix well, and obtain a coating solution; Step S3: performing corona treatment on the polypropylene film to obtain a corona polypropylene film; coating the coating liquid on the corona surface of the corona polypropylene film, and drying it to obtain a printable OPP varnishing film.

[0007] Furthermore, the coating liquid includes the following raw materials in parts by weight: 30-40 parts of polyurethane prepolymer, 60-80 parts of pre-emulsified monomer, 400-500 parts of deionized water, 8-12 parts of ammonium persulfate aqueous solution, 1-3 parts of hydroxypropyl methacrylate, 3-8 parts of triethylamine, 0.3-0.6 parts of leveling agent, 0.1-0.5 parts of defoaming agent, and 1-3 parts of adhesion promoter.

[0008] Furthermore, the concentration of the ammonium persulfate aqueous solution is 3 wt %.

[0009] Furthermore, the polyurethane prepolymer comprises the following raw materials in parts by weight: 40-50 parts of polyether polyol, 70-90 parts of isophorone diisocyanate, 1-3 parts of dibutyltin dilaurate, 2-4 parts of 2,2-dihydroxymethylbutyric acid, and 5-15 parts of modified hyperbranched fluorine-containing polymer.

[0010] Furthermore, the preparation method of the modified hyperbranched fluoropolymer comprises the following steps: Under nitrogen protection, dodecafluoroheptyl methacrylate, diethanolamine and acetonitrile are mixed evenly and reacted at 75-85°C for 8-10 hours to obtain a fluorinated diol; under nitrogen protection, the fluorinated diol is condensed with vinyltrimethoxysilane. After the reaction, vacuum drying is performed to obtain a modified hyperbranched fluorinated polymer.

[0011] Furthermore, the molar ratio of dodecafluoroheptyl methacrylate to diethanolamine is 1:(1-1.2).

[0012] Furthermore, the molar ratio of the fluorinated diol to vinyltrimethoxysilane is (1-2):1.

[0013] Furthermore, the condensation reaction is carried out in three stages, namely the first reaction stage, the second reaction stage and the third reaction stage.

[0014] Furthermore, the reaction temperature of the first reaction stage is 80-90° C., and the reaction time is 2-3 h.

[0015] Furthermore, the reaction temperature of the second reaction stage is 150-170°C and the reaction time is 0.5-2h. Furthermore, the third reaction stage is carried out under natural cooling conditions, and the reaction temperature is reduced from 150-170°C to 70-90°C.

[0016] Furthermore, the condensation reaction is carried out in the presence of a catalyst, and the molar amount of the catalyst is 0.005-0.01% based on the total molar amount of the vinyltrimethoxysilane and the fluorinated diol as 100%; the catalyst includes at least one of p-toluenesulfonic acid, sulfuric acid, tetramethylammonium hydroxide or sodium hydroxide.

[0017] Furthermore, the pre-emulsified monomer includes the following raw materials in parts by weight: 30-40 parts of methyl methacrylate, 40-50 parts of butyl acrylate, 10-20 parts of hydroxyethyl acrylate, 5-15 parts of double-bonded silica, 3-6 parts of emulsifier, and 150-300 parts of deionized water.

[0018] Furthermore, the emulsifier is one or more of sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), ethoxylated alkyl sulfate sodium salt (CM30), isomeric tridecyl alcohol sulfate sodium salt (2030S), and rhamnolipid.

[0019] Furthermore, the preparation method of the double bond-containing silicon dioxide is as follows: Step A: Ultrasonic dispersion of silica in a mixed solution of anhydrous ethanol and deionized water, adding γ-aminopropyltriethoxysilane and mixing evenly, reacting at 70-80° C. for 3-5 hours, centrifuging, washing, and drying to obtain amino silica; Step B: Under nitrogen protection, amino silica, linoleic acid and dimethyl sulfoxide are mixed evenly, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine are added, and the mixture is stirred at room temperature for 22-24 hours. After filtering, washing and drying, silica containing double bonds is obtained.

[0020] Furthermore, in step A, the mass ratio of silicon dioxide to anhydrous ethanol, deionized water, and 3-aminopropyltrimethoxysilane is 1:(10-12):(2-4):(0.3-0.5).

[0021] Furthermore, in the step B, the mass ratio of amino silicon dioxide, linoleic acid and dimethyl sulfoxide is 1: (2-4): (5-10).

[0022] Furthermore, the mass ratio of the amino-silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride diimide and 4-dimethylaminopyridine is 1:(0.1-0.2):(0.08-0.10).

[0023] Furthermore, the corona treatment process is as follows: the power of the corona machine is 4-8KW, and the speed of the corona machine is 80-120m / min.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention discloses a printable OPP glazing film and its preparation process. A polyurethane prepolymer terminated with isocyanate groups is first prepared, which is then copolymerized with an acrylate monomer and double-bonded silica to form an interpenetrating network structure. The polyurethane segments provide flexibility and water resistance, while the acrylates impart hardness and quick-drying properties, significantly improving the adhesion of the coating solution. Specifically, the scheme uses dodecafluoroheptyl methacrylate (DFHMA) and diethanolamine (DEOA) to prepare a fluorinated diol. The fluorinated diol is then reacted with vinyltrimethoxysilane as raw materials to produce an A2+B3 type modified hyperbranched fluorinated polymer. By introducing the modified hyperbranched fluorinated polymer into the polyurethane prepolymer, the fluorine element compensates for the deficiencies in water resistance, oil resistance, and weather resistance. The hyperbranched structure and the introduction of fluorinated and siloxane segments effectively reduce surface viscosity, resulting in excellent anti-stick properties and preventing adhesion during film winding. The introduction of vinyl groups provides reaction sites for subsequent chemical reactions, allowing the polyurethane material to be further modified or cross-linked.

[0025] 2. A printable OPP glazing film and its preparation process of the present invention, the preparation of pre-emulsified monomers adopts methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and double-bonded silica. The hydroxyl group of hydroxyethyl acrylate can form hydrogen bonds with the corona surface to enhance adhesion. The double-bonded silica can be used as an anti-sticking agent. By grafting linoleic acid, double bonds and hydrophobic long chains are introduced, so that it can participate in the copolymerization reaction of acrylate and be firmly anchored in the polymer network to avoid migration. At the same time, roughness is formed on the coating surface, the smoothness is reduced, the printability is significantly improved, and printability is achieved. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] In this embodiment, the polyether polyol: brand CP450, sourced from Dow Chemical; leveling agent: model KYC-615 of Keying; defoaming agent: model BYK-028; adhesion promoter: model TEGO AddBond DS1300; silica: hydroxy silica microsphere powder, particle size 5-10 μm; polypropylene film: thickness 50-100 μm, sourced from Foshan Yitong Packaging Products Co., Ltd.

[0028] The following parts are by mass unless otherwise specified.

[0029] Example 1: A process for preparing a printable OPP glazing film, comprising the following steps: Step S1: 40 parts of polyether polyol were vacuum dehydrated at 110° C. for 2 hours, cooled to 60° C., and under nitrogen protection, 70 parts of isophorone diisocyanate and 1 part of dibutyltin dilaurate were added, mixed evenly, and reacted for 1 hour. 2 parts of 2,2-dihydroxymethylbutyric acid and 5 parts of modified hyperbranched fluoropolymer were added, and reacted for 3 hours to obtain a polyurethane prepolymer; Mix 3 parts of sodium lauryl sulfate and 150 parts of deionized water, add 30 parts of methyl methacrylate, 40 parts of butyl acrylate, 10 parts of hydroxyethyl acrylate and 5 parts of double-bonded silica, mix well, add pre-emulsification for 0.5h, and obtain pre-emulsified monomer; Step S2: 30 parts of polyurethane prepolymer, 60 parts of pre-emulsified monomer and 400 parts of deionized water were mixed, the temperature was raised to 70°C, 8 parts of 3wt% ammonium persulfate aqueous solution were added dropwise, the temperature was completely added for 1 hour, the reaction was continued for 2 hours, the temperature was further raised to 85°C, 1 part of hydroxypropyl methacrylate was added, and the reaction was continued for 1 hour; the temperature was lowered to 30°C, 3 parts of triethylamine were added for neutralization, 0.1 parts of defoaming agent, 0.3 parts of leveling agent and 1 part of adhesion promoter were added, and the mixture was mixed uniformly to obtain a coating solution; Step S3: corona treatment of the polypropylene film (corona machine power 4KW, corona machine speed 80m / min) to obtain a corona polypropylene film; coating the coating liquid on the corona surface of the corona polypropylene film (coating amount 1.8g / m 2 ), after drying, a printable OPP varnishing film is obtained; The preparation method of the modified hyperbranched fluoropolymer comprises the following steps: Under nitrogen protection, dodecafluoroheptyl methacrylate, diethanolamine and acetonitrile were uniformly mixed and reacted at 75°C for 8 hours to obtain a fluorinated diol; under nitrogen protection, the fluorinated diol was mixed with vinyltrimethoxysilane and condensed in the presence of p-toluenesulfonic acid (the reaction temperature of the first reaction stage was 80°C and the reaction time was 2 hours; the reaction temperature of the second reaction stage was 150°C and the reaction time was 0.5 hours; the third reaction stage was carried out under natural cooling conditions, with the reaction temperature dropping from 150°C to 70°C). After the reaction, the mixture was vacuum dried to obtain a modified hyperbranched fluorinated polymer; the molar ratio of dodecafluoroheptyl methacrylate to diethanolamine was 1:1; the molar ratio of the fluorinated diol to vinyltrimethoxysilane was 1:1; and the molar amount of p-toluenesulfonic acid was 0.005% of the total molar amount of vinyltrimethoxysilane and the fluorinated diol; The preparation method of double bond-containing silica is as follows: Step A: 5 parts of silica were ultrasonically dispersed in a mixed solution of 50 parts of anhydrous ethanol and 10 parts of deionized water, 1.5 parts of γ-aminopropyltriethoxysilane were added and mixed evenly, and the mixture was reacted at 70° C. for 3 hours. After centrifugation, washing, and drying, amino-modified silica was obtained; Step B: Under nitrogen protection, 5 parts of amino silica, 10 parts of linoleic acid and 25 parts of dimethyl sulfoxide were mixed evenly, 0.5 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.4 parts of 4-dimethylaminopyridine were added, and the mixture was stirred at room temperature for 22 hours. After filtering, washing and drying, silica containing double bonds was obtained.

[0030] Example 2: A process for preparing a printable OPP glazing film, comprising the following steps: Step S1: 45 parts of polyether polyol were vacuum dehydrated at 115° C. for 2.5 hours, cooled to 65° C., and under nitrogen protection, 80 parts of isophorone diisocyanate and 2 parts of dibutyltin dilaurate were added, mixed evenly, and reacted for 2 hours. 3 parts of 2,2-dihydroxymethylbutyric acid and 10 parts of modified hyperbranched fluoropolymer were added, and reacted for 4 hours to obtain a polyurethane prepolymer; Mix 5 parts of sodium lauryl sulfate and 250 parts of deionized water, add 35 parts of methyl methacrylate, 45 parts of butyl acrylate, 15 parts of hydroxyethyl acrylate and 10 parts of double-bonded silica, mix well, add pre-emulsification for 1 hour to obtain pre-emulsified monomer; Step S2: 35 parts of a polyurethane prepolymer, 70 parts of a pre-emulsified monomer, and 450 parts of deionized water were mixed, the temperature was raised to 75° C., 10 parts of a 3 wt% aqueous solution of ammonium persulfate were added dropwise, the mixture was dripped over 1.5 hours, the mixture was reacted for 3 hours, the temperature was further raised to 87° C., 2 parts of hydroxypropyl methacrylate were added, and the mixture was reacted for 2 hours; the temperature was lowered to 35° C., 5 parts of triethylamine were added for neutralization, 0.3 parts of a defoamer, 0.5 parts of a leveling agent, and 2 parts of an adhesion promoter were added, and the mixture was mixed uniformly to obtain a coating solution; Step S3: corona treatment of the polypropylene film (corona machine power of 5KW, corona machine speed of 100m / min) to obtain a corona polypropylene film; coating the coating liquid on the corona surface of the corona polypropylene film (coating amount of 2.5g / m 2 ), after drying, a printable OPP varnishing film is obtained; The preparation method of the modified hyperbranched fluoropolymer comprises the following steps: Under nitrogen protection, dodecafluoroheptyl methacrylate, diethanolamine and acetonitrile were uniformly mixed and reacted at 80°C for 9 hours to obtain a fluorinated diol. Under nitrogen protection, the fluorinated diol was mixed with vinyltrimethoxysilane and subjected to a condensation reaction in the presence of p-toluenesulfonic acid (the reaction temperature of the first reaction stage was 85°C and the reaction time was 2.5 hours; the reaction temperature of the second reaction stage was 160°C and the reaction time was 1 hour; the third reaction stage was carried out under natural cooling conditions, with the reaction temperature dropping from 160°C to 80°C). After the reaction, the mixture was vacuum dried to obtain a modified hyperbranched fluorinated polymer. The molar ratio of dodecafluoroheptyl methacrylate to diethanolamine was 1:1.1; the molar ratio of the fluorinated diol to vinyltrimethoxysilane was 1.5:1; and the molar amount of p-toluenesulfonic acid was 0.008% of the total molar amount of vinyltrimethoxysilane and the fluorinated diol. The preparation method of double bond-containing silica is as follows: Step A: 10 parts of silica were ultrasonically dispersed in a mixed solution of 110 parts of anhydrous ethanol and 30 parts of deionized water, 4 parts of γ-aminopropyltriethoxysilane were added and mixed evenly, and the mixture was reacted at 80° C. for 4 hours. After centrifugation, washing, and drying, amino-modified silica was obtained; Step B: Under nitrogen protection, 10 parts of amino silica, 30 parts of linoleic acid and 80 parts of dimethyl sulfoxide were mixed evenly, 1.5 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.9 parts of 4-dimethylaminopyridine were added, and the mixture was stirred at room temperature for 23 hours. After filtering, washing and drying, silica containing double bonds was obtained.

[0031] Example 3: A process for preparing a printable OPP glazing film, comprising the following steps: Step S1: 50 parts of polyether polyol were vacuum dehydrated at 120° C. for 3 hours, cooled to 70° C., and under nitrogen protection, 90 parts of isophorone diisocyanate and 3 parts of dibutyltin dilaurate were added, mixed evenly, and reacted for 3 hours. 4 parts of 2,2-dihydroxymethylbutyric acid and 15 parts of modified hyperbranched fluoropolymer were added, and reacted for 5 hours to obtain a polyurethane prepolymer; Mix 6 parts of sodium lauryl sulfate and 300 parts of deionized water, add 40 parts of methyl methacrylate, 50 parts of butyl acrylate, 20 parts of hydroxyethyl acrylate and 15 parts of double-bonded silica, mix well, add pre-emulsification for 1.5 hours to obtain pre-emulsified monomer; Step S2: 40 parts of a polyurethane prepolymer, 80 parts of a pre-emulsified monomer, and 500 parts of deionized water were mixed, the temperature was raised to 80° C., 12 parts of a 3 wt% aqueous solution of ammonium persulfate were added dropwise, the mixture was dripped over 2 hours, the mixture was reacted for 4 hours, the temperature was further raised to 90° C., 3 parts of hydroxypropyl methacrylate were added, and the mixture was reacted for 3 hours; the temperature was lowered to 40° C., 8 parts of triethylamine were added for neutralization, 0.5 parts of a defoamer, 0.6 parts of a leveling agent, and 3 parts of an adhesion promoter were added, and the mixture was mixed uniformly to obtain a coating solution; Step S3: corona treatment of the polypropylene film (corona machine power 4-8KW, corona machine speed 120m / min) to obtain a corona polypropylene film; coating the coating liquid on the corona surface of the corona polypropylene film (coating amount 2.8g / m 2 ), after drying, a printable OPP varnishing film is obtained; The preparation method of the modified hyperbranched fluoropolymer comprises the following steps: Under nitrogen protection, dodecafluoroheptyl methacrylate, diethanolamine and acetonitrile are uniformly mixed and reacted at 85°C for 10 hours to obtain a fluorinated diol; under nitrogen protection, the fluorinated diol is mixed with vinyltrimethoxysilane and condensed in the presence of p-toluenesulfonic acid (the reaction temperature of the first reaction stage is 90°C and the reaction time is 3 hours; the reaction temperature of the second reaction stage is 170°C and the reaction time is 2 hours; the third reaction stage is carried out under natural cooling conditions, and the reaction temperature is reduced from 170°C to 90°C). After the reaction, vacuum drying is carried out to obtain a modified hyperbranched fluorinated polymer; the molar ratio of dodecafluoroheptyl methacrylate to diethanolamine is 1:1.2; the molar ratio of the fluorinated diol to vinyltrimethoxysilane is 2:1; the molar amount of p-toluenesulfonic acid is 0.01% of the total molar amount of vinyltrimethoxysilane and the fluorinated diol; The preparation method of double bond-containing silica is as follows: Step A: 15 parts of silica were ultrasonically dispersed in a mixed solution of 180 parts of anhydrous ethanol and 60 parts of deionized water, 7.5 parts of γ-aminopropyltriethoxysilane were added and mixed evenly, and the mixture was reacted at 80° C. for 5 hours. After centrifugation, washing, and drying, amino-modified silica was obtained; Step B: Under nitrogen protection, 15 parts of amino silica, 60 parts of linoleic acid and 150 parts of dimethyl sulfoxide were mixed evenly, 3 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.5 parts of 4-dimethylaminopyridine were added, and the mixture was stirred at room temperature for 24 hours. After filtering, washing and drying, silica containing double bonds was obtained.

[0032] Comparative Example 1: A process for preparing a printable OPP glazing film, comprising the following processes: Compared with Example 2, Comparative Example 1 does not introduce the modified hyperbranched fluorine-containing polymer, and the other steps are the same as those of Example 2.

[0033] Comparative Example 2: A process for preparing a printable OPP glazing film, comprising the following processes: Compared with Example 2, Comparative Example 2 does not introduce double-bond silicon dioxide, and other steps are the same as Example 2.

[0034] Comparative Example 3: A process for preparing a printable OPP glazing film, comprising the following processes: Compared with Example 2, in Comparative Example 3, the pre-emulsified monomer was replaced with an acrylic water-based resin of the same mass (brand: Hanwha Soluryl-60L), and the other steps were the same as in Example 2.

[0035] Experiment: The printable OPP glazing films obtained in Examples 1-3 and Comparative Examples 1-3 were used to prepare samples, and their properties were tested and the test results were recorded: Water absorption test: Refer to GB / T 1733-1993 "Determination of water resistance of paint films". The sample size is 20mm×20mm×1mm. After weighing, it is immersed in deionized water. After 24 hours, it is taken out and the water on the surface of the cured film is quickly and gently wiped off and weighed to calculate the water absorption.

[0036] Coating fluid adhesion test: Adhesion was assessed using the cross-hatch method according to GB / T 9286-2021. The number of grids where the coating did not peel off was recorded, with 100 being the best, indicating no peeling at all, and 0 being the worst, indicating complete peeling.

[0037] Ink Adhesion Test: Adhesion was assessed using the cross-hatch method, referring to GB / T 9286-2021. The specific steps are as follows: A heat-curable ink (brand: Peters SD 2696 TSW, Germany) was applied to a printable OPP varnish. After drying, a 25μm thick ink coating was obtained. A crosshatch knife was used to score the ink coating. The sample was placed in boiling water for 20 minutes, then removed and air-dried to room temperature. Adhesion was then tested, and the number of squares where the ink layer remained intact was recorded.

[0038] The test results are shown in Table 1.

[0039] Table 1 Test results of printable OPP varnish performance

[0040] According to the data in the above table, we can clearly draw the following conclusions: 1. Compared with Examples 1-3, the water absorption and adhesion of the products obtained in Comparative Examples 1 and 2 are both reduced, indicating that the present invention significantly improves the water resistance and adhesion to ink of the coating by synergistically introducing modified hyperbranched fluoropolymer and double-bonded silica.

[0041] 2. Compared with Examples 1-3, the water absorption rate and adhesion of the product obtained in Comparative Example 3 are both reduced. Compared with commercially available acrylic water-based resins, the present invention significantly improves the crosslinking density and surface micro-roughness of the coating by introducing pre-emulsified monomers, thereby improving the hydrophobic properties and bonding strength of the material.

[0042] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A process for preparing a printable OPP glazing film, characterized by: The steps include: Step S1: vacuum dehydrating the polyether polyol at 110-120° C. for 2-3 hours, cooling to 60-70° C., adding isophorone diisocyanate and dibutyltin dilaurate under nitrogen protection, mixing uniformly, reacting for 1-3 hours, adding 2,2-dihydroxymethylbutyric acid and modified hyperbranched fluoropolymer, and reacting for 3-5 hours to obtain a polyurethane prepolymer; Mix the emulsifier and deionized water evenly, add methyl methacrylate, butyl acrylate, hydroxyethyl acrylate and double-bonded silica and mix evenly, add pre-emulsification for 0.5-1.5h to obtain pre-emulsified monomer; Step S2: Mix the polyurethane prepolymer, pre-emulsified monomer and deionized water, heat to 70-80°C, add ammonium persulfate aqueous solution dropwise for 1-2 hours, react for 2-4 hours, continue to heat to 85-90°C, add hydroxypropyl methacrylate, react for 1-3 hours; cool to 30-40°C, add triethylamine for neutralization, add defoamer, leveling agent and adhesion promoter, mix well, and obtain a coating solution; Step S3: performing corona treatment on the polypropylene film to obtain a corona polypropylene film; coating the coating liquid on the corona surface of the corona polypropylene film, and drying it to obtain a printable OPP varnishing film.

2. The process for preparing a printable OPP glazing film according to claim 1, characterized in that: The coating liquid includes the following raw materials in parts by weight: 30-40 parts of polyurethane prepolymer, 60-80 parts of pre-emulsified monomer, 400-500 parts of deionized water, 8-12 parts of ammonium persulfate aqueous solution, 1-3 parts of hydroxypropyl methacrylate, 3-8 parts of triethylamine, 0.3-0.6 parts of leveling agent, 0.1-0.5 parts of defoaming agent, and 1-3 parts of adhesion promoter.

3. The process for preparing a printable OPP glazing film according to claim 2, characterized in that: The polyurethane prepolymer comprises the following raw materials in parts by weight: 40-50 parts of polyether polyol, 70-90 parts of isophorone diisocyanate, 1-3 parts of dibutyltin dilaurate, 2-4 parts of 2,2-dihydroxymethylbutyric acid, and 5-15 parts of modified hyperbranched fluorine-containing polymer.

4. The process for preparing a printable OPP glazing film according to claim 3, characterized in that: The preparation method of the modified hyperbranched fluoropolymer comprises the following steps: Under nitrogen protection, dodecafluoroheptyl methacrylate, diethanolamine and acetonitrile are mixed evenly and reacted at 75-85°C for 8-10 hours to obtain a fluorinated diol; under nitrogen protection, the fluorinated diol is condensed with vinyltrimethoxysilane. After the reaction, vacuum drying is performed to obtain a modified hyperbranched fluorinated polymer.

5. The process for preparing a printable OPP glazing film according to claim 4, characterized in that: The molar ratio of dodecafluoroheptyl methacrylate to diethanolamine is 1:(1-1.2).

6. The process for preparing a printable OPP glazing film according to claim 3, characterized in that: The pre-emulsified monomer comprises the following raw materials in parts by weight: 30-40 parts of methyl methacrylate, 40-50 parts of butyl acrylate, 10-20 parts of hydroxyethyl acrylate, 5-15 parts of double-bonded silicon dioxide, 3-6 parts of emulsifier, and 150-300 parts of deionized water.

7. The process for preparing a printable OPP glazing film according to claim 6, characterized in that: The preparation method of the double bond-containing silicon dioxide is as follows: Step A: Ultrasonic dispersion of silica in a mixed solution of anhydrous ethanol and deionized water, adding γ-aminopropyltriethoxysilane and mixing evenly, reacting at 70-80° C. for 3-5 hours, centrifuging, washing, and drying to obtain amino silica; Step B: Under nitrogen protection, amino silica, linoleic acid and dimethyl sulfoxide are mixed evenly, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine are added, and the mixture is stirred at room temperature for 22-24 hours. After filtering, washing and drying, silica containing double bonds is obtained.

8. The process for preparing a printable OPP glazing film according to claim 6, characterized in that: The emulsifier is one or more of sodium lauryl sulfate, sodium dodecylbenzene sulfonate, ethoxylated alkyl sulfate sodium salt, isomeric tridecyl alcohol sulfate sodium salt, and rhamnolipid.

9. The process for preparing a printable OPP glazing film according to claim 1, characterized in that: The coating amount of the coating liquid is 1.8-2.8g / m 2 .

10. A printable OPP glazing film prepared according to the preparation process according to any one of claims 1 to 9.

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