Anti-fogging master batch suitable for two-way stretching process and preparation method of anti-fogging master batch

Abstract

The invention is applicable to the field of antifogging, and discloses an antifogging master batch applicable to a two-way stretching process and a preparation method thereof.The antifogging master batch is prepared from, by weight, 4-5 parts of methacrylic resin, 2-4 parts of acrylic acid, 1-3 parts of 1, 2-propylene glycol, 1-3 parts of 1, 3-propylene glycol and 1-3 parts of a coupling agent. The adhesive comprises the following components in parts by weight: 1-2 parts of 1, 4-butanediol dimethacrylate, 1-2 parts of methacrylic acid 2-(dimethylamino) ethyl ester, 0.05-0.1 part of an initiator and 8-12 parts of a first solvent. According to the anti-fog master batch disclosed by the invention, through synergistic cooperation of hydrophilic groups and hydrophobic groups, a condensation and tumbling cycle is formed, a good long-time anti-fog effect is realized, VOC emission in the production process is low, low polymers are difficult to accumulate on a film die lip, and the stability and environmental protection property of film processing are ensured. Meanwhile, the binding force between the ink layer and the packaging film is enhanced through the special polymerization structure and molecular chain design of the anti-fog master batch, so that the finished film is remarkable in anti-fog effect and suitable for oil-based ink printing, and the application range of the product is expanded.

Description

Technical Field

[0001] The present application relates to the field of anti-fog, and in particular to an anti-fog masterbatch suitable for a biaxial stretching process and a preparation method thereof. Background Art

[0002] Currently, the anti-fog masterbatches used in the biaxially oriented anti-fog films based on polypropylene on the market are divided into two categories. The first category is mainly based on hydrophilic groups, that is, amino groups and hydroxyl groups, which achieve the anti-fog effect by absorbing water. Once the groups of the anti-fog masterbatch reach saturation with water, the anti-fog effect will drop significantly, so this anti-fog effect is not permanent; the second category is anti-fog masterbatch containing silicon and fluorine, which achieves the anti-fog effect through hydrophobic effect. This type of anti-fog effect is permanent, but because it contains more non-polar materials, the anti-fog film produced using this type of anti-fog masterbatch cannot be printed, and the product needs to be labeled separately, which increases the production cost. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes an anti-fog masterbatch suitable for a biaxial stretching process. The anti-fog masterbatch of the present application is different from the existing anti-fog masterbatch. The anti-fog mechanism of the present application is that through the synergistic cooperation of hydrophilic groups and hydrophobic groups, when steam contacts the material of the present application, the hydrophilic groups condense the steam to form droplets, and then the hydrophobicity of the hydrophobic groups causes the droplets to roll off. After the droplets roll off, the hydrophilic groups continue to condense the steam into droplets, forming a cycle of condensation and rolling off, achieving an anti-fog effect, while not affecting the penetration of organic solvents. Therefore, the anti-fog masterbatch of the application can prevent fog while not affecting oil-based ink printing.

[0004] The anti-fog masterbatch is calculated in parts by weight and includes the following components: 4-5 parts of methacrylic resin, 2-4 parts of acrylic acid, 1-2 parts of 1,4-butanediol dimethacrylate, 1-2 parts of 2-(dimethylamino)ethyl methacrylate, 0.05-0.1 parts of initiator and 8-12 parts of the first solvent.

[0005] To be more specific, in the above technical solution, the anti-fog masterbatch, calculated in parts by weight, includes the following components: 5 parts of methacrylic resin, 2 parts of acrylic acid, 2 parts of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of initiator and 10 parts of the first solvent.

[0006] To be more specific, in the above technical solution, the anti-fog masterbatch, calculated in parts by weight, includes the following components: 4 parts of methacrylic resin, 4 parts of acrylic acid, 1 part of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of di-tert-butyl peroxide and 10 parts of the first solvent.

[0007] More specifically, in the above technical solution, the anti-fog masterbatch comprises the following components, calculated by weight: 0.5-3 parts of modified fluorocarbon resin.

[0008] More specifically, in the above technical solution, the modified fluorocarbon resin includes, by weight percentage, 50-60% of a fluorocarbon resin matrix, 18-22% of methyl methacrylate, 4-6% of glycidyl methacrylate, 0.8-1.2% of azobisisobutyronitrile, and the remainder, a second solvent.

[0009] More specifically, in the above technical solution, the preparation method of the modified fluorocarbon resin includes: uniformly mixing the raw materials of the modified fluorocarbon resin in proportion, stirring at a speed of 100-200 rpm at 110-130°C for 6-10 hours, and cooling, washing, and drying in sequence.

[0010] More specifically, in the above technical solution, the anti-fog masterbatch comprises the following components, calculated in parts by weight: 0.8-2 parts of vinyltriethoxysilane.

[0011] More specifically, in the above technical solution, the initiator includes at least one of di-tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane, di-tert-butyl peroxide, dicumyl peroxide and benzoyl peroxide.

[0012] More specifically, in the above technical solution, the first solvent is ethyl acetate.

[0013] The present application also proposes a method for preparing an anti-fog masterbatch suitable for a biaxial stretching process, comprising heating and stirring the raw material components of any of the above-mentioned anti-fog masterbatches in proportion, recovering the solvent to obtain a polymer, and putting the polymer, polypropylene pellets and sodium dicyclohexyl sulfosuccinate into an extruder, extruding, water-cooling and then pelletizing to obtain the anti-fog masterbatch.

[0014] Compared with the prior art, the embodiments of the present application have the following beneficial effects: First, the present application overcomes the defect of non-permanent anti-fog effect of traditional hydrophilic group anti-fog masterbatch, and achieves long-lasting anti-fog performance through the synergistic cooperation of hydrophilic groups and hydrophobic groups; secondly, the anti-fog masterbatch of the present application solves the problem that silicon- and fluorine-containing anti-fog masterbatch cannot be printed. The anti-fog masterbatch of the present application has excellent printability and does not require additional labeling, thereby reducing production costs; thirdly, the anti-fog masterbatch of the present application has low VOC emissions and excellent environmental protection performance during the production process, while avoiding the accumulation of oligomers on the die lip, thereby improving the stability and quality of film processing; more importantly, the polymer structure and molecular chain designed in the present application significantly enhance the bonding force between the ink layer and the packaging film, so that the anti-fog film has good printing adaptability while maintaining excellent anti-fog effect, greatly broadening the application field and market prospects of the product. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0017] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present invention. Thus, the phrase "in some embodiments" appearing in different places in this specification does not necessarily refer to the same embodiment, but rather means "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0018] The materials and reagents in this application can be purchased from the market.

[0019] This application proposes an anti-fog masterbatch suitable for biaxial stretching processes. This anti-fog masterbatch is suitable for PET, BOPET, CPP, BOPP, CPE, or BOPE films and can be used as a matte layer material for cast, uniaxially stretched, or biaxially stretched films. The anti-fog masterbatch comprises the following components, calculated by weight: 4-5 parts methacrylic resin, 2-4 parts acrylic acid, 1-2 parts 1,4-butanediol dimethacrylate, 1-2 parts 2-(dimethylamino)ethyl methacrylate, 0.05-0.1 parts initiator, and 8-12 parts first solvent.

[0020] First, the present application overcomes the defect of non-permanent anti-fog effect of traditional hydrophilic group anti-fog masterbatch, and achieves long-lasting anti-fog performance through the synergistic cooperation of hydrophilic groups and hydrophobic groups; secondly, the anti-fog masterbatch of the present application solves the problem that silicon- and fluorine-containing anti-fog masterbatch cannot be printed. The anti-fog masterbatch of the present application has excellent printability and does not require additional labeling, thereby reducing production costs; thirdly, the anti-fog masterbatch of the present application has low VOC emissions and excellent environmental protection performance during the production process, while avoiding the accumulation of oligomers on the die lip, thereby improving the stability and quality of film processing; more importantly, the polymer structure and molecular chain designed in the present application significantly enhance the bonding force between the ink layer and the packaging film, so that the anti-fog film has good printing adaptability while maintaining excellent anti-fog effect, greatly broadening the application field and market prospects of the product.

[0021] On the other hand, the anti-fog masterbatch of the present application also does not contain amide polymerization monomers. In the prior art CN113088131A, due to the presence of amide polymers, the VOC emissions during the extrusion process may be high. After film formation, the polymers, such as oleamide and erucamide, will migrate to the surface of the film, resulting in a decrease in the bonding strength between the ink layer and the packaging film.

[0022] The anti-fog layer of the present application is formed by polymerization of monomers. The oligomers can be reduced by extending the polymerization time or by reducing the titration rate of the polymerization process. Therefore, the VOC emissions during the extrusion film forming process are low, and after film formation, there are almost no migratable oligomers that affect the bonding strength between the ink layer and the packaging film. In addition, in the anti-fog masterbatch of the present application, methacrylic resin, acrylic acid, 1,4-butanediol dimethacrylate and 2-(dimethylamino)ethyl methacrylate can provide bonding strength with the dispersed phase in the oil-based ink (currently in the printing industry, the dispersed phase of the oil-based ink is mainly ethyl acetate and butyl acetate). The principle is the electrical interaction between polar molecules. Microscopically, the compatibility between carboxyl groups, hydroxyl groups and ester groups is high, which is reflected in the improved bonding strength between the ink layer and the packaging film on a macroscopic level. Anti-fog principle: After the polymerization of methacrylate resin, acrylic acid, 1,4-butanediol dimethacrylate and 2-(dimethylamino)ethyl methacrylate, the methyl, ethyl and other alkane branches on the molecular side chains have water repellency. The interaction of the four components and the control of the polymerization ratio can indirectly control the number and relative position of the methyl and ethyl groups on the side chains, thereby adjusting the spatial steric hindrance of the molecular chain to prevent water vapor from forming water mist and only forming larger droplets that roll down.

[0023] The methacrylic acid resin in this application can be a homopolymer of methacrylic acid, also known as polymethacrylic acid, purchased from Shanghai Maclean Biochemical Technology Co., Ltd., and acrylic acid is purchased from BASF AG of Germany; 1,4-butanediol dimethacrylate is purchased from Celanese Corporation of the United States or Shanghai Maclean Biochemical Technology Co., Ltd.; 2-(dimethylamino)ethyl methacrylate is purchased from Qingdao Reinars Polymer Materials Co., Ltd.

[0024] In some embodiments, the anti-fog masterbatch includes the following components, calculated by weight: 5 parts of methacrylic resin, 2 parts of acrylic acid, 2 parts of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of initiator and 10 parts of the first solvent.

[0025] The specific combination of methacrylic resin, acrylic acid, 1,4-butanediol dimethacrylate and 2-(dimethylamino)ethyl methacrylate achieves the best distribution of alkane side chains such as methyl and ethyl on the molecular chain by controlling the above-mentioned polymerization ratio, thereby ensuring that the polymer has hydrophilic groups while also having hydrophobic groups, and the hydrophilic groups and hydrophobic groups can cooperate with each other. The hydrophilic groups condense water vapor into droplets, and when saturation is reached, the droplets roll down due to the presence of the hydrophobic groups, effectively preventing water vapor from condensing into fog on the surface of the film. Only larger droplets can roll down, ensuring a long-term and stable anti-fog effect.

[0026] In some embodiments, the anti-fog masterbatch includes the following components, calculated in parts by weight: 4 parts of methacrylic resin, 4 parts of acrylic acid, 1 part of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of di-tert-butyl peroxide, and 10 parts of the first solvent.

[0027] In some specifically optimized embodiments, the ratio of the anti-fog masterbatch has been carefully adjusted to show unique advantages. Specifically, the anti-fog masterbatch is based on 4 parts of methacrylic resin and supplemented with 4 parts of acrylic acid. This combination not only enhances the stability of the material, but also improves its overall performance. At the same time, the addition of 1 part of 1,4-butanediol dimethacrylate and 1 part of 2-(dimethylamino)ethyl methacrylate effectively regulates the molecular structure of the polymer, giving it better hydrophobicity and anti-fog effect. In addition, a trace amount of initiator ensures the smooth progress of the polymerization reaction, and its high efficiency reduces the formation of by-products, further improving the purity of the product.

[0028] In some embodiments, the anti-fog masterbatch comprises the following components, calculated in parts by weight: 0.5-3 parts of modified fluorocarbon resin.

[0029] Fluorocarbon resins have extremely low surface energy, making them ideal for preparing water-repellent materials. This application modifies fluorocarbon resins to ensure they maintain water-repellency while maintaining good compatibility with oil-based inks and substrates. Specifically, the modified fluorocarbon resins of this application, due to their unique chemical structure and low surface energy, can effectively prevent water vapor from condensing into fog on the film surface, thereby further enhancing the durability of the anti-fog effect. Compared with traditional hydrophilic group anti-fog masterbatches, their anti-fog effect is more stable and less susceptible to changes in ambient humidity.

[0030] In some embodiments, the modified fluorocarbon resin comprises, by weight percentage, 50-60% fluorocarbon resin matrix, 18-22% methyl methacrylate, 4-6% glycidyl methacrylate, 0.8-1.2% azobisisobutyronitrile, and the remainder, a second solvent. Preferably, the fluorocarbon resin matrix is polychlorotrifluoroethylene, and the second solvent is isopropyl alcohol.

[0031] By introducing methyl methacrylate (MMA, 18-22%) and glycidyl methacrylate (GMA, 4-6%) as modifying monomers, the modified fluorocarbon resin achieves high compatibility with the dispersed phase in oil-based inks. The polar groups formed during the polymerization process enhance the bonding strength with the ink layer, resulting in an anti-fog film that not only exhibits excellent anti-fog properties but also meets various printing requirements, eliminating the need for additional labeling and reducing production costs.

[0032] In some embodiments, the preparation method of the modified fluorocarbon resin includes: uniformly mixing the raw materials of the modified fluorocarbon resin in proportion, stirring at 100-200 rpm at 110-130° C. for 6-10 hours, and sequentially cooling, washing, and drying.

[0033] Specifically, a method for preparing a modified fluorocarbon resin comprises: adding, by weight, 55% polytrifluorochloroethylene, 18% methyl methacrylate (MMA), 4% glycidyl methacrylate (GMA), 1% azobisisobutyronitrile (AIBN), and 22% isopropyl alcohol to the modified fluorocarbon resin; stirring the mixture at 120°C and 150 rpm for 8 hours; cooling the reaction mixture to room temperature; and removing unreacted monomers and solvent by filtration, washing, and drying to obtain a pure modified fluorocarbon resin. The modified fluorocarbon resins described in the examples were prepared using this method.

[0034] In some embodiments, the anti-fog masterbatch comprises the following components, calculated in parts by weight: 0.8-2 parts of vinyltriethoxysilane.

[0035] Vinyltriethoxysilane can be used as a crosslinking agent in the anti-fog masterbatch of this application. The crosslinking agent makes the surface of the polymer generated by the reaction denser, greatly reducing the penetration path and attachment points of water molecules, effectively preventing the condensation of water vapor on the surface of the film, thereby significantly improving the anti-fog effect.

[0036] Furthermore, the resulting cross-linked structure increases the stability and durability of the anti-fog masterbatch, making the anti-fog effect more durable. This cross-linked structure effectively resists the adverse effects of fluctuations in environmental factors such as temperature and humidity, maintaining long-term stability in anti-fog performance.

[0037] In some embodiments, the initiator includes at least one of di-tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane, di-tert-butyl peroxide, dicumyl peroxide, and benzoyl peroxide. Preferably, the initiator is di-tert-butyl peroxide (CAS No.: 110-05-4).

[0038] As a highly efficient initiator, di-tert-butyl peroxide can accelerate the polymerization rate, effectively shorten the production cycle, and improve production efficiency. Compared with other initiators, di-tert-butyl peroxide produces fewer by-products during the polymerization reaction, which helps maintain the purity and quality stability of the product, reduces the complexity and cost of subsequent processing steps, and improves the market competitiveness of the product.

[0039] By using di-tert-butyl peroxide as a highly efficient initiator, the molecular structure and segment distribution of the polymer can be optimized, further enhancing the performance of the anti-fog masterbatch. For example, the number and position of alkane side chains, such as methyl and ethyl groups, in the polymer can be controlled, resulting in a more effective hydrophobic and anti-fog effect.

[0040] In some embodiments, the first solvent is ethyl acetate.

[0041] First, as a commonly used organic solvent, ethyl acetate has relatively low volatility, which helps reduce volatile organic compound (VOC) emissions during the preparation process, thereby complying with current environmentally friendly production requirements and reducing environmental pollution. Second, ethyl acetate has good solubility for raw materials such as methacrylate resin and acrylic acid, which helps to evenly disperse the raw materials in the solvent, allowing the subsequent polymerization reaction to be more complete and uniform, improving product quality and stability. Finally, because the dispersed phase of oil-based inks in the printing industry is mainly composed of ester solvents such as ethyl acetate, anti-fog masterbatches prepared using ethyl acetate as the solvent exhibit better compatibility with the ink layer during the subsequent printing process, improving ink adhesion and reducing printing defects.

[0042] The present application also proposes a method for preparing an anti-fog masterbatch suitable for a biaxial stretching process, comprising heating and stirring the raw material components of any of the above-mentioned anti-fog masterbatches in proportion, recovering the solvent to obtain a polymer, and putting the polymer, polypropylene pellets and sodium dicyclohexyl sulfosuccinate into an extruder, extruding, water-cooling and then pelletizing to obtain the anti-fog masterbatch.

[0043] The anti-fog masterbatch prepared by the method of the present application can significantly improve the anti-fog effect, printability and environmental performance of the film.

[0044] Unless otherwise specified, the raw materials and equipment used in this application are commonly used in this field; unless otherwise specified, the methods used in this invention are conventional methods in this field.

[0045] Unless otherwise specified, the meanings of the terms in this specification are the same as those generally understood by those skilled in the art. However, if there is any conflict, the definitions in this specification shall prevail.

[0046] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0047] Example 1: The anti-fog masterbatch, calculated by weight: 10 parts ethyl acetate, 5 parts methacrylic resin, 2 parts acrylic acid, 2 parts 1,4-butanediol dimethacrylate, 1 part 2-(dimethylamino)ethyl methacrylate, and 0.05 parts di-tert-butyl peroxide, was mixed thoroughly in a pre-mixer and then added to the reactor. The titration rate was 60 kg / h, and the reactor temperature was controlled at 85°C. After the titration was completed, the temperature was maintained at 90°C for 2 hours, and some ethyl acetate was recovered during the insulation process.

[0048] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0049] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts anti-fog masterbatch, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. These ingredients are fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0050] The obtained pellets are used as raw material additives for the anti-fog layer of the anti-fog film, with the surface layer addition accounting for 10% of the total proportion of the film. After undergoing conventional BOPP processing steps (extruder feeding section 35°C, melting section 220°C, homogenization section 220°C, shear rate 90rpm), the conventional BOPP processing steps are common knowledge in the field and will not be described in detail in this application. After processing, the anti-fog film is obtained by quenching and biaxial stretching.

[0051] Example 1 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip; VOC emissions from the extrusion zone reached a maximum of 20 mg / m³. The finished film achieved Level 1 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥47 N / 15 mm.

[0052] Note: Anti-fog Level 1: Completely transparent, no water droplets; the clarity of the eye chart remains the same as before the test. Anti-fog Level 2: Good transparency, with a small amount of uneven large water droplets; the clarity of more than 50% of the eye chart remains the same as before the test. Anti-fog Level 3: Basically transparent, with a large number of water droplets, and the font on the eye chart is distorted (the same below).

[0053] Example 2: The anti-fog masterbatch, calculated by weight, consists of the following: 10 parts ethyl acetate, 4 parts methacrylic acid resin, 4 parts acrylic acid, 1 part 1,4-butanediol dimethacrylate, 1 part 2-(dimethylamino)ethyl methacrylate, and 0.05 parts di-tert-butyl peroxide. The mixture is then mixed thoroughly in a pre-mixer and added to the reactor. The titration rate is 60 kg / h, and the reactor temperature is controlled at 85°C. After the titration is complete, the temperature is maintained at 90°C for 2 hours, during which some ethyl acetate is recovered.

[0054] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0055] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts anti-fog masterbatch, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. These ingredients are fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0056] The resulting pellets are used as additives for the anti-fog layer of anti-fog films. The surface layer accounts for 10% of the total film. After conventional BOPP processing (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0057] Example 2 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip. VOC emissions from the extrusion zone reached a maximum of 45 mg / m³. The finished film achieved Level 2 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥47 N / 15 mm.

[0058] Example 3: The anti-fog masterbatch (by weight): 10 parts ethyl acetate, 5 parts methacrylic acid resin, 2 parts acrylic acid, 2 parts 1,4-butanediol dimethacrylate, 1 part 2-(dimethylamino)ethyl methacrylate, 0.05 parts di-tert-butyl peroxide, and 2.5 parts modified fluorocarbon resin were mixed in a pre-mixer and then added to the reactor. The titration rate was 60 kg / h, and the reactor temperature was controlled at 85°C. After the titration was completed, the temperature was maintained at 90°C for 2 hours, and some ethyl acetate was recovered during the insulation process.

[0059] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0060] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts anti-fog masterbatch, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. These ingredients are fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0061] The obtained pellets are used as raw material additives for the anti-fog layer of the anti-fog film, with the surface layer addition accounting for 10% of the total proportion of the film. After undergoing conventional BOPP processing steps (extruder feeding section 35°C, melting section 220°C, homogenization section 220°C, shear rate 90rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0062] Example 3 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip; VOC emissions from the extrusion zone reached a maximum of 15 mg / m³. The finished film achieved Level 1 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥52 N / 15 mm.

[0063] Example 3 includes a modified fluorocarbon resin, which further enhances anti-fog properties while also improving compatibility with oil-based inks. The polar groups formed during polymerization by monomers such as methyl methacrylate (MMA) and glycidyl methacrylate (GMA) in the modified fluorocarbon resin also help strengthen the bond between the ink layer and the packaging film.

[0064] Example 4: The anti-fog masterbatch, calculated by weight, consists of the following: 10 parts ethyl acetate, 4 parts methacrylic acid resin, 4 parts acrylic acid, 1 part 1,4-butanediol dimethacrylate, 1 part 2-(dimethylamino)ethyl methacrylate, 0.05 parts di-tert-butyl peroxide, and 1.6 parts vinyltriethoxysilane. The mixture is then mixed thoroughly in a pre-mixer and added to the reactor. The titration rate is 60 kg / h, and the reactor temperature is controlled at 85°C. After the titration is complete, the temperature is maintained at 90°C for 2 hours, during which some ethyl acetate is recovered.

[0065] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0066] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts anti-fog masterbatch, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. These ingredients are fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0067] The resulting pellets are used as additives for the anti-fog layer of anti-fog films. The surface layer accounts for 10% of the total film. After conventional BOPP processing (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0068] Example 4 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip. VOC emissions from the extrusion zone reached a maximum of 40 mg / m³. The finished film achieved Level 1 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥51 N / 15 mm.

[0069] Vinyltriethoxysilane can be used as a crosslinking agent in the anti-fog masterbatch of this application. The crosslinking agent makes the surface of the polymer generated by the reaction denser, greatly reducing the penetration path and attachment points of water molecules, effectively preventing the condensation of water vapor on the surface of the film, thereby significantly improving the anti-fog effect.

[0070] Furthermore, the resulting cross-linked structure increases the stability and durability of the anti-fog masterbatch, making the anti-fog effect more durable. This cross-linked structure effectively resists the adverse effects of fluctuations in environmental factors such as temperature and humidity, maintaining long-term stability in anti-fog performance.

[0071] Comparative Example 1: The anti-fog masterbatch, model Df-u-7-2, sold by Linyi Sujiang New Material Technology Co., Ltd., was used. The surface layer added accounted for 10% of the total film content. The film was processed through standard BOPP processing steps (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), followed by quenching and biaxial stretching to produce the anti-fog film.

[0072] Comparative Example 1 test results: After four hours of continuous production, a small amount of oil droplets of condensation were observed at the die lip. VOC emissions from the extrusion area reached a maximum of 80 mg / m³. The finished film achieved Level 1 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥42 N / 15 mm.

[0073] Comparative Example 2: AC2822, a silicone anti-fog additive sold by Guangdong Fangzhou Chemical Industry Co., Ltd., was used. The surface layer, which accounted for 10% of the total film, was processed through standard BOPP processing steps (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), followed by quenching and biaxial stretching to produce the anti-fog film.

[0074] Comparative Example 2 test results: After four hours of continuous production, a small amount of oil droplets of condensation were observed at the die lip. VOC emissions from the extrusion area reached a maximum of 10 mg / m³. The finished film's anti-fog performance met the Class 1 anti-fog requirement specified in GBT 31726-2015. However, the film's post-printing performance after electrode treatment was poor, with ink adhesion ≤18 N / 15 mm.

[0075] Comparative Example 3: The anti-fog masterbatch, calculated by weight: 10 parts ethyl acetate, 4 parts methacrylic resin, 3 parts 1,4-butanediol dimethacrylate, 3 parts 2-(dimethylamino)ethyl methacrylate, and 0.05 parts di-tert-butyl peroxide, was mixed thoroughly in a pre-mixer and then added to the reactor. The titration rate was 60 kg / h, and the reactor temperature was controlled at 85°C. After the titration was completed, the temperature was maintained at 90°C for 2 hours, and some ethyl acetate was recovered during the insulation process.

[0076] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0077] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts polymer, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. The mixture is fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0078] The resulting pellets are used as additives for the anti-fog layer of anti-fog films. The surface layer accounts for 10% of the total film. After conventional BOPP processing (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0079] Comparative Example 3 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip. Maximum VOC emissions from the extrusion zone were 45 mg / m³. The finished film's anti-fog performance met the Class 1 anti-fog requirement specified in GBT 31726-2015. However, the film's post-printing performance after electrode treatment was poor, with ink adhesion ≤25 N / 15 mm.

[0080] Comparative Example 3, in which acrylic acid was not added, showed no decrease in anti-fog effectiveness. However, the ink adhesion of Comparative Example 3 was significantly lower than that of Examples 1 and 2. This is understood to be because the carboxyl groups of acrylic acid are key sites for reaction with inks. Without the addition of acrylic acid, the interfacial chemical bonding capacity is significantly weakened, thus affecting the ink adhesion of the anti-fog masterbatch. Although the anti-fog effect of Comparative Example 3 was not reduced, the ink adhesion declined, failing to achieve the desired effect of the anti-fog masterbatch described in this application: maintaining an anti-fog effect while not affecting oil-based ink printing.

[0081] Comparative Example 4: The following anti-fog masterbatch (by weight): 10 parts ethyl acetate, 4 parts methacrylic resin, 3 parts acrylic acid, 3 parts 1,4-butanediol dimethacrylate, and 0.05 parts di-tert-butyl peroxide (CAS No. 110-05-4) were mixed thoroughly in a premixer and then added to the reactor. The titration rate was 60 kg / h, and the reactor temperature was controlled at 85°C. After the titration was complete, the temperature was maintained at 90°C for 2 hours, with some ethyl acetate recovered during the temperature retention period.

[0082] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0083] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts polymer, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. The mixture is fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0084] The resulting pellets are used as additives for the anti-fog layer of anti-fog films. The surface layer accounts for 10% of the total film. After conventional BOPP processing (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0085] Comparative Example 4 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip. VOC emissions from the extrusion zone reached a maximum of 25 mg / m³. The finished film achieved Level 3 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥40 N / 15 mm.

[0086] Comparative Example 4, in which 2-(dimethylamino)ethyl methacrylate was omitted, showed that the film's anti-fog durability deteriorated. 2-(dimethylamino)ethyl methacrylate, through its unique functional groups (such as the aminoethyl ester group), enhances its interaction with other components in the formulation and helps form a stable hydrophobic layer. Its absence destabilizes the hydrophobic layer, making the anti-fog effect less durable.

[0087] On the other hand, the absence of 2-(dimethylamino)ethyl methacrylate prevents the formation of sufficient crosslinking points between the molecular chains in the anti-fog masterbatch, which in turn reduces the penetration and anchoring of ink molecules on the film surface. The ink layer is more susceptible to peeling or shedding, reducing the overall printing quality and durability of the product. Therefore, the presence of 2-(dimethylamino)ethyl methacrylate in the formula is crucial to ensuring the long-lasting anti-fog effect and good ink adhesion of the anti-fog film.

[0088] Comparative Example 5: The anti-fog masterbatch (by weight): 10 parts ethyl acetate, 4 parts methacrylic resin, 3 parts acrylic acid, 3 parts 2-(dimethylamino)ethyl methacrylate, and 0.05 parts di-tert-butyl peroxide were mixed in a pre-mixer and then added to the reactor. The titration rate was 60 kg / h, and the reactor temperature was controlled at 85°C. After the titration was completed, the temperature was maintained at 90°C for 2 hours, and some ethyl acetate was recovered during the insulation process.

[0089] The desired anti-fog masterbatch is obtained after recovering the solvent ethyl acetate.

[0090] Processing: Add the following additives (by weight) to the anti-fog film's anti-fog layer: 4 parts polymer, 6 parts polypropylene pellets, and 0.05 parts sodium dicyclohexyl sulfosuccinate. The mixture is fed into an extruder at a temperature of 40°C in the feeding section, 220°C in the melting section, 220°C in the homogenizing section, and 130 rpm. The extruded strips are then water-cooled at 20°C before being pelletized.

[0091] The resulting pellets are used as additives for the anti-fog layer of anti-fog films. The surface layer accounts for 10% of the total film. After conventional BOPP processing (extruder feeding section at 35°C, melting section at 220°C, homogenization section at 220°C, shear rate at 90 rpm), the anti-fog film is produced by quenching and biaxial stretching.

[0092] Comparative Example 5 test results: After 8 hours of continuous production, no oil droplets or condensation were observed at the die lip. VOC emissions from the extrusion zone reached a maximum of 10 mg / m³. The finished film achieved Level 3 anti-fog performance as specified in GBT 31726-2015. After electrode treatment, the film exhibited excellent printing results, with ink adhesion ≥35 N / 15 mm.

[0093] Comparative Example 5, in which 1,4-butanediol dimethacrylate was omitted, showed reduced hydrophobicity and anti-fog effectiveness. 1,4-Butanediol dimethacrylate, as a key crosslinking monomer, is crucial for regulating the polymer's molecular structure and improving its hydrophobic properties. Its absence reduced the degree of molecular chain branching and steric hindrance, thus compromising the anti-fog effect.

[0094] Furthermore, the absence of 1,4-butanediol dimethacrylate reduces the degree of molecular chain branching in the polymer, which in turn affects its surface morphology and the distribution of polar groups. This reduces the interaction between the polymer and the polar dispersed phase in the ink, thereby weakening the bonding between the ink layer and the packaging film. Because 1,4-butanediol dimethacrylate contributes to hydrophobicity, its absence also reduces the water contact angle on the film surface, increasing the film's surface wettability, hindering uniform ink adhesion and stable bonding during the drying process.

[0095] Furthermore, when conducting the anti-fog test, the present application carried out the cold mist method, rapid hot mist method and water bath hot mist method tests respectively according to the method in GB / T31726-2015. According to the test method in the standard, for the cold mist method, the specific operation is: inject (200±10)mL, (23±2)℃, grade 3 water that meets the requirements of GB / T 6682-2008 into a flat beaker.

[0096] Fix the sample with double-sided tape or rubber band so that the anti-fog test surface is placed on the beaker mouth. The test area should be flat.

[0097] Place the flat-mouth beaker with the sample fixed in it into a low-temperature constant temperature box or refrigerator at a temperature of (3±2)℃ and start timing.

[0098] After 5 minutes, remove the beaker containing the sample and place it on the standard logarithmic near vision chart in Appendix B of GB 11533-2011, with the center of the bottom of the beaker aligned with the 0.1 center line of the vision chart. Under natural light or a 40 W fluorescent lamp, observe the surface of the film sample from top to bottom perpendicular to the bottom of the beaker. The observation should be completed within 5 seconds.

[0099] In this application, when the cold mist method is carried out, for Example 1, Comparative Example 1 and Comparative Example 2, the contact time of the anti-fog material with water is extended to test the durability of its anti-fog effect; in actual operation, the refrigeration time of the sample is extended to 90 minutes, and the housing effect of Example 1 is still level 1; while for Comparative Example 1 and Comparative Example 2, they are both level 4.

[0100] For the rapid thermal fog method, the specific operation is to place a flat-mouthed beaker on the standard logarithmic near vision chart in Appendix B of GB 11533-2011, align the bottom center of the beaker with the 0.1 center line of the vision chart, and inject (200±10)mL, (85±2)℃, third-grade water that meets the requirements of GB / T 6682-2008.

[0101] Quickly secure the sample with double-sided tape or a rubber band, placing the anti-fog performance test surface against the beaker rim. The test area should be flat. Start timing at this point, and the test time is 60 seconds.

[0102] The total time to complete the sample fixation in the above steps shall not exceed 20s.

[0103] At 60 seconds, observe the surface of the film sample from top to bottom perpendicular to the bottom of the beaker under natural light or a 40W fluorescent lamp. The observation should be completed within 5 seconds.

[0104] In the present application, when performing the rapid hot fog method, for Example 1, Comparative Example 1 and Comparative Example 2, the contact time between the anti-fog material and water was extended to test the durability of its anti-fog effect; in actual operation, the refrigeration time of the sample was extended to 10 minutes, and the anti-fog effect of Example 1 was still level 1; while for Comparative Example 1 and Comparative Example 2, it was both level 4.

[0105] For the water bath hot mist method, the specific operation is: add tap water to the water tank, fix the standard logarithmic near vision chart in Appendix B of GB11533-2011 on the bottom plate of the water bath after waterproofing, and the clarity of the vision chart visible in the water is consistent with that in the natural state.

[0106] Pour (200±10)mL of (23±2)℃ grade tertiary water that meets the requirements of GB / T 6682-2008 into a flat-mouth beaker.

[0107] Fix the sample with double-sided tape or rubber band so that the anti-fog performance test surface is buckled against the beaker mouth. The test area should be flat.

[0108] Place the flat-mouth beaker containing the sample in a constant temperature water bath at (60±2)℃, so that the bottom of the beaker is submerged in the water bath by (50±5)mm, and start timing.

[0109] After 15 minutes, observe the surface of the film sample from top to bottom perpendicular to the bottom of the beaker under natural light or a 40W fluorescent lamp, and complete the observation within 5 seconds.

[0110] In the present application, when performing the water bath hot mist method, for Example 1, Comparative Example 1 and Comparative Example 2, the contact time between the anti-fog material and water was extended to test the durability of its anti-fog effect; in actual operation, the refrigeration time of the sample was extended to 30 minutes, and the anti-fog effect of Example 1 was still level 1; while for Comparative Example 1 and Comparative Example 2, it was both level 4.

[0111] Based on the three tests described above, it can be seen that the anti-fog durability of the anti-fog material of the present application is superior to that of Comparative Examples 1 and 2. This is because the anti-fog masterbatch described in the present application, through the synergistic combination of hydrophilic and hydrophobic groups, allows steam to condense into droplets when it contacts the material of the present application through the hydrophilic groups. The hydrophobicity of the hydrophobic groups then causes the droplets to roll off. After the droplets roll off, the hydrophilic groups continue to condense the steam into droplets, forming a cycle of condensation and rolling off, achieving the anti-fog effect. Furthermore, due to the synergistic combination of hydrophilic and hydrophobic groups, the anti-fog material of the present application can continuously absorb water, condense the steam into droplets, and thus achieve long-lasting anti-fog effect.

[0112] The various technical features of the above-described embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The above-described embodiments merely represent several embodiments of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. An anti-fog masterbatch suitable for biaxial stretching process, characterized in that: The anti-fog masterbatch is calculated in parts by weight and includes the following components: 4-5 parts of methacrylic resin, 2-4 parts of acrylic acid, 1-2 parts of 1,4-butanediol dimethacrylate, 1-2 parts of 2-(dimethylamino)ethyl methacrylate, 0.05-0.1 parts of initiator and 8-12 parts of the first solvent.

2. The anti-fog masterbatch suitable for biaxial stretching process according to claim 1, characterized in that: The anti-fog masterbatch includes the following components, calculated by weight: 5 parts of methacrylic resin, 2 parts of acrylic acid, 2 parts of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of initiator and 10 parts of the first solvent.

3. The anti-fog masterbatch suitable for biaxial stretching process according to claim 1, characterized in that: The anti-fog masterbatch includes the following components, calculated by weight: 4 parts of methacrylic resin, 4 parts of acrylic acid, 1 part of 1,4-butanediol dimethacrylate, 1 part of 2-(dimethylamino)ethyl methacrylate, 0.05 parts of di-tert-butyl peroxide, and 10 parts of a first solvent.

4. The anti-fog masterbatch suitable for biaxial stretching process according to claim 1, characterized in that: The anti-fog masterbatch comprises the following components calculated by weight: 0.5-3 parts of modified fluorocarbon resin.

5. The anti-fog masterbatch suitable for biaxial stretching process according to claim 4, characterized in that: The modified fluorocarbon resin comprises, by weight percentage, 50-60% of a fluorocarbon resin matrix, 18-22% of methyl methacrylate, 4-6% of glycidyl methacrylate, 0.8-1.2% of azobisisobutyronitrile, and the balance being a second solvent.

6. The anti-fog masterbatch suitable for biaxial stretching process according to claim 5, characterized in that: The preparation method of the modified fluorocarbon resin comprises: uniformly mixing the raw materials of the modified fluorocarbon resin according to a certain proportion, stirring at a temperature of 110-130° C. and a rotation speed of 100-200 rpm for 6-10 hours, and sequentially cooling, washing, and drying.

7. The anti-fog masterbatch suitable for biaxial stretching process according to claim 1, characterized in that: The anti-fog masterbatch comprises the following components calculated in parts by weight: 0.8-2 parts of vinyltriethoxysilane.

8. The anti-fog masterbatch suitable for biaxial stretching process according to any one of claims 1 to 7, characterized in that: The initiator includes at least one of di-tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane, di-tert-butyl peroxide, dicumyl peroxide and benzoyl peroxide.

9. The anti-fog masterbatch suitable for biaxial stretching process according to any one of claims 1 to 7, characterized in that: The first solvent is ethyl acetate.

10. A method for preparing an anti-fog masterbatch suitable for a biaxial stretching process, characterized in that: The method comprises heating and stirring the raw material components of the anti-fog masterbatch according to any one of claims 1 to 9 in proportion, recovering the solvent to obtain a polymer, feeding the polymer, polypropylene pellets and sodium dicyclohexyl sulfosuccinate into an extruder, extruding, water-cooling and then pelletizing to obtain the anti-fog masterbatch.