High-toughness, stain-resistant and mildew-proof decorative film and preparation method thereof

Abstract

The invention discloses a high-toughness, stain-resistant and mildew-proof decorative film and a preparation method thereof, and belongs to the technical field of decorative films. The polyvinyl chloride base film is prepared from the following components in parts by mass: 77 to 89 parts of polyvinyl chloride resin, 21 to 29 parts of chlorinated polyethylene resin, 4 to 12 parts of toughening mildew preventive and 4 to 8 parts of additive. Wherein the chlorinated polyethylene resin can improve the impact resistance of the base film; wherein the toughening mildew preventive molecules contain a plurality of functional groups, so that the mildew resistance and impact resistance of the decorative film can be improved; the stain-resistant coating has super-hydrophobicity, self-cleaning can be realized, and the daily cleaning difficulty is reduced; in conclusion, the impact resistance, the mildew resistance and the stain resistance of the prepared decorative film are remarkably improved, the problems of a traditional PVC decorative film are solved, and the decorative film is particularly suitable for places such as kitchens and bathrooms which need to be cleaned frequently or are possibly impacted accidentally, and has important application value in the technical field of decorative films.

Description

Technical Field

[0001] The present invention belongs to the technical field of decorative films, and specifically, relates to a high-toughness stain-resistant and mildew-proof decorative film and a preparation method thereof. Background Art

[0002] With the rapid development of the modern architectural decoration industry, people's requirements for the performance of interior decoration materials are increasing day by day. Among them, decorative films are a kind of functional materials widely used in the fields of architecture, furniture, household appliances, etc. Their main function is to provide protection, beautification and special functions for the substrates. Currently, common decorative films on the market mostly use substrates such as polyvinyl chloride (PVC), polypropylene (PP) or polyester (PET). Among them, polyvinyl chloride has low chromaticity, is easy to process, has a low price and stable chemical properties, and is the most widely used in the field of decorative films.

[0003] Although traditional polyvinyl chloride decorative films can meet certain requirements in terms of aesthetics and basic protection functions, there are still many deficiencies in actual use. For example, the texture of polyvinyl chloride is relatively brittle and is prone to problems such as cracking and tearing due to external force impact or long-term use. This low-toughness characteristic makes polyvinyl chloride decorative films vulnerable to damage during transportation, installation and daily use, thereby reducing their overall service life. Especially in some places that need to be frequently cleaned or may be accidentally impacted, such as kitchens and bathrooms, the low-toughness problem of decorative films is particularly prominent. Secondly, stain resistance is another key performance index of decorative films. Traditional polyvinyl chloride decorative films are easily contaminated with dirt such as oil stains and dust during daily use, resulting in a deteriorated appearance and increased cleaning difficulty. Thirdly, mildew-proof performance is also crucial for decorative films, especially in environments with high humidity, such as bathrooms and basements. The growth of mildew not only damages the appearance of decorative films but also releases harmful substances, posing a threat to the health of occupants.

[0004] The above problems limit the application scope of polyvinyl chloride decorative films in humid environments or highly polluted areas. Therefore, it is urgent to develop a polyvinyl chloride decorative film with high toughness, stain resistance and mildew-proof performance to meet the higher application requirements in the technical field of decorative films. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a high-toughness stain-resistant and mildew-proof decorative film and a preparation method thereof.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A high-toughness stain-resistant and mildew-proof decorative film is composed of a polyvinyl chloride base film and a stain-resistant coating. The polyvinyl chloride base film is composed of the following components in parts by mass: 77 - 89 parts of polyvinyl chloride resin, 21 - 29 parts of chlorinated polyethylene resin, 4 - 12 parts of a toughening and mildew-proof agent, and 4 - 8 parts of an additive.

[0007] Further, the additive is composed of an antioxidant and a lubricant in a mass ratio of 1:3.

[0008] Furthermore, the antioxidant is a hindered phenol antioxidant.

[0009] Furthermore, the lubricant is one of oleamide, butyl stearate and stearic acid.

[0010] Chlorinated polyethylene is added to the raw materials. It has good compatibility with polyvinyl chloride and can be evenly dispersed in the polyvinyl chloride matrix to form a "sea-island structure", absorb impact energy and improve the toughness of the base film.

[0011] Further, the toughening and mildew-proof agent is prepared through the following steps: Step A1: Weigh 2-aminothiazole and 3,5-dihydroxybenzoic acid as reaction raw materials, and add them together with N,N-dimethylformamide into a 300 mL three-necked flask equipped with a magnetic stirrer. After magnetic stirring, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the system. At room temperature, stir and react for 8 h. After the reaction is completed, filter, remove part of the solvent by reduced pressure distillation, and purify by column chromatography to obtain reaction product 1; The reaction principle of Step A1 is: under the catalysis of 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), the amino group in the 2-aminothiazole molecule reacts with the carboxyl group on 3,5-dihydroxybenzoic acid to undergo an amidation reaction; the reaction formula is as follows:

[0012] Step A2: Weigh pyridine and 1,10-dichlorodecane as reaction raw materials, add them into a 300 mL three-necked flask equipped with a thermometer, a condenser and a magnetic stirrer. After magnetic stirring, heat the device until the temperature stabilizes at 70 °C. Stir and react at this temperature for 6 h. After the reaction is completed, filter, remove part of the solvent by reduced pressure distillation, and purify by column chromatography to obtain reaction product 2; The reaction principle of Step A2 is: this reaction is a solvent-free reaction. The nitrogen atom of pyridine acts as a strong nucleophile and undergoes a nucleophilic substitution reaction (SN2) with 1,10-dichlorodecane. Control the molar ratio of the two at 1:1, and 1,10-dichlorodecane is slightly in excess to reduce side reactions; the reaction formula is as follows:

[0013] Step A3: Weigh reaction product 1 and reaction product 2 as reaction raw materials, and add them together with anhydrous toluene into a 300 mL three-necked flask equipped with a thermometer, a constant pressure dropping funnel, a condenser and a magnetic stirrer. At room temperature, under stirring, slowly add sodium hydroxide solution (mass fraction 20%) through the constant pressure dropping funnel. After the addition is complete, heat the device until the temperature stabilizes at 75 °C. Stir and react at this temperature for 5 h. After the reaction is completed, filter, remove part of the solvent by vacuum distillation, purify by column chromatography, and dry under vacuum to obtain the toughening and mildew-proof agent; The reaction principle of Step A3 is as follows: Sodium hydroxide can react with the hydroxyl group in the molecule of reaction product 1 to form a phenolate with stronger nucleophilicity, and react with the chloro group in the molecule of reaction product 2; control the molar ratio of the two at 1:2, and make reaction product 2 slightly in excess to reduce side reactions.

[0014] Furthermore, in Step A1, the dosage ratio of 2-aminothiazole, 3,5-dihydroxybenzoic acid, N,N-dimethylformamide, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide is 9.9 g: 15.4 g: 100 mL: 15.5 g.

[0015] Furthermore, in Step A2, the dosage ratio of pyridine and 1,10-dichlorodecane is 7.9 g: 23.7 g.

[0016] Furthermore, in Step A3, the dosage ratio of reaction product 1, reaction product 2, anhydrous toluene, and sodium hydroxide solution is 23.6 g: 52.3 g: 150 mL: 40 mL.

[0017] The toughening and mildew-proof agent is prepared through three-step reactions. The experimental principle is not complicated, the raw materials are clear, and the operation is clear. The prepared toughening and mildew-proof agent molecule contains two long-chain alkyl structures. This structure has high flexibility, can increase the free volume of the molecular chain, reduce the packing density between molecular chains, and the long-chain alkyl can be embedded in the polymer macromolecule to absorb energy and disperse stress when the matrix is under external force, prevent local stress concentration, improve the impact resistance of the polyvinyl chloride matrix, and also improve the migration resistance of the toughening and mildew-proof agent and the stability of the small molecule toughening and mildew-proof agent; Moreover, the toughening and mildew-proof agent also contains pyridinium quaternary salt and thiazole groups. The N of the pyridinium quaternary salt + can strongly bind to the negatively charged surface of the mold cell membrane (such as the phosphate group of the phospholipid head group and the carboxyl group of the protein), destroy the cell structure of the mold, and has a long persistence and a fast action speed, improving the mildew-proof performance of the matrix; while the thiazole group belongs to a sulfur-containing group, can bind to the key enzymes of the mold (such as sulfhydryl enzymes), inhibit their activity, and thus interfere with the metabolic process of the mold, further improving the mildew-proof performance of the matrix; it should be emphasized that the mildew-proof mechanisms of the pyridinium quaternary salt and the thiazole group are different. Therefore, the two can play a synergistic role and greatly improve the mildew-proof performance of the matrix.

[0018] Further, the stain-resistant coating is prepared through the following steps: Add hydrophobic silica into absolute ethanol, ultrasonically disperse for 15 - 30 min, then mix with methyltrimethoxysilane, tridecafluorooctyltriethoxysilane and tetraethyl orthosilicate. After stirring evenly, slowly dropwise add hydrochloric acid solution and continuously stir to promote the hydrolysis reaction of siloxane. After stirring for 2 - 3 h, stop stirring to obtain the stain-resistant coating.

[0019] Furthermore, the dosage ratio of the hydrophobic silica, absolute ethanol, methyltrimethoxysilane, tridecafluorooctyltriethoxysilane, tetraethyl orthosilicate and hydrochloric acid solution is 8.7 g : 100 mL : 56.2 g : 3.6 g : 5.1 g : 5 mL.

[0020] Introducing fluorine-containing groups into the coating significantly reduces the surface energy and improves the hydrophobicity. The addition of hydrophobic silica makes the coating rougher, increases the contact angle between water droplets and the coating, and further improves the hydrophobic performance. Therefore, the prepared coating is a superhydrophobic coating, and the lotus leaf structure on the surface takes away dust and other pollutants, having a self-cleaning effect and can improve the stain resistance of the decorative film.

[0021] The present invention also provides a preparation method of a high-toughness stain-resistant and mildew-proof decorative film, including the following steps: Coat a layer of stain-resistant coating on the surface of the polyvinyl chloride base film using an intaglio printing roller, and then place it in an oven at 100 - 120 °C for drying and curing. After taking it out, a high-toughness stain-resistant and mildew-proof decorative film is obtained.

[0022] Advantages of the present invention: The decorative film prepared by the present invention is composed of a polyvinyl chloride base film and a stain-resistant coating; 1. Adding chlorinated polyethylene resin to the base film can effectively absorb impact energy, enhance the impact resistance of the base film, and solve the problem that traditional PVC decorative films are prone to brittle fracture; 2. The toughening and mildew-proof agent is prepared through three-step reactions. The toughening and mildew-proof agent molecule contains multiple functional groups, which can improve the mildew resistance and impact resistance of the decorative film; 3. Introducing hydrophobic silica and fluorosilane into the stain-resistant coating to form a superhydrophobic surface, greatly reducing the surface energy. The "lotus leaf effect" on the coating surface can achieve self-cleaning, reduce the adhesion of pollutants such as oil stains and dust, and reduce the difficulty of daily cleaning; Therefore, through the modification of chlorinated polyethylene, the preparation of the stain-resistant coating, and the introduction of the toughening and mildew-proof agent, the impact resistance, mildew resistance and stain resistance of the decorative film are significantly improved, solving the problems of traditional PVC decorative films, and are particularly suitable for places such as kitchens and bathrooms that require frequent cleaning or may be accidentally impacted. Specific embodiments

[0023] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0024] Example 1: Preparation of toughened mildew-proof agent: Step A1: Weigh 9.9 g of 2-aminothiazole and 15.4 g of 3,5-dihydroxybenzoic acid as reaction raw materials, and add them together with 100 mL of N,N-dimethylformamide into a 300 mL three-necked flask equipped with a magnetic stirrer. After magnetic stirring, add 15.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide to the system. At room temperature, stir and react for 8 h. After the reaction is completed, filter, remove part of the solvent by reduced pressure distillation, purify by column chromatography (the eluent is petroleum ether and ethyl acetate, and the volume ratio of the two is 3:1), and remove the eluent by rotary evaporation to obtain reaction product 1; Step A2: Weigh 7.9 g of pyridine and 23.7 g of 1,10-dichlorodecane as reaction raw materials, add them into a 300 mL three-necked flask equipped with a thermometer, a condenser and a magnetic stirrer. After magnetic stirring, heat the device until the temperature stabilizes at 70 °C, and stir and react at this temperature for 6 h. After the reaction is completed, filter, remove part of the solvent by reduced pressure distillation, purify by column chromatography (the eluent is petroleum ether and ethyl acetate, and the volume ratio of the two is 5:1), and remove the eluent by rotary evaporation to obtain reaction product 2; Step A3: Weigh 23.6 g of reaction product 1, 52.3 g of reaction product 2 and 150 mL of anhydrous toluene as reaction raw materials, add them into a 300 mL three-necked flask equipped with a thermometer, a constant pressure dropping funnel, a condenser and a magnetic stirrer. At room temperature, while stirring, slowly add 40 mL of sodium hydroxide solution (mass fraction 20%) through the constant pressure dropping funnel. After the addition is completed, heat the device until the temperature stabilizes at 75 °C, and stir and react at this temperature for 5 h. After the reaction is completed, filter, remove part of the solvent by reduced pressure distillation, purify by column chromatography (the eluent is petroleum ether and ethyl acetate, and the volume ratio of the two is 10:1), remove the eluent by rotary evaporation, and dry in vacuum to obtain the toughened mildew-proof agent.

[0025] Example 2: Preparation of stain-resistant coating: 8.7 g of hydrophobic silica (mix 1 g of nano-silica produced by Hangzhou Hengge Nano-Technology Co., Ltd., model HN-SP15, with 100 mL of ethanol aqueous solution, add it to a magnetic stirring device, add a magnet, turn on the stirring, and disperse for 30 min to make the nano-silica evenly dispersed in the ethanol aqueous solution. The device is evacuated and N2 Add gas, then add 7.3 g of KH-560, start oil bath heating, set at 50 °C, turn on the condenser water, set at 80 °C and react for 4 h, perform suction filtration, wash with ethanol, and then dry in a vacuum drying oven for 2 h to obtain hydrophobic nano-silica) Add it to 100 mL of anhydrous ethanol, ultrasonically disperse for 30 min, then mix it with 56.2 g of methyltrimethoxysilane, 3.6 g of trifluorooctyltriethoxysilane, and 5.1 g of tetraethyl orthosilicate, stir evenly, and then slowly dropwise add 5 mL of hydrochloric acid solution (mass fraction 12%), and continuously stir to promote the hydrolysis reaction of siloxane. After stirring for 3 h, stop stirring to obtain a stain-resistant coating.

[0026] Example 3: Preparation of a polyvinyl chloride-based film: Add 77 g of polyvinyl chloride resin (produced by Xinjiang Zhongtai Chemical Co., Ltd., model SG-3), 21 g of chlorinated polyethylene resin (produced by Weifang Yaxing Chemical Co., Ltd., model CPE 135A), 4 g of the toughening and mildew-proof agent prepared in Example 1, and 4 g of additives (1 g of antioxidant 1076 and 3 g of oleamide) into a mixer, mix at 1200 r / min, stir for 5 min, then add the mixed raw materials into an extruder, melt and blend, extrude, cast onto a cooling roll, form a film through cooling and shaping, with a thickness of 50 μm, and wind up to obtain a polyvinyl chloride-based film.

[0027] Example 4: Preparation of a polyvinyl chloride-based film: Add 83 g of polyvinyl chloride resin (produced by Xinjiang Zhongtai Chemical Co., Ltd., model SG-3), 25 g of chlorinated polyethylene resin (produced by Weifang Yaxing Chemical Co., Ltd., model CPE 135A), 8 g of the toughening and mildew-proof agent prepared in Example 1, and 6 g of additives (1.5 g of antioxidant 1076 and 4.5 g of butyl stearate) into a mixer, mix at 1200 r / min, stir for 5 min, then add the mixed raw materials into an extruder, melt and blend, extrude, cast onto a cooling roll, form a film through cooling and shaping, with a thickness of 50 μm, and wind up to obtain a polyvinyl chloride-based film.

[0028] Example 5: Preparation of a polyvinyl chloride-based film: 89 g of polyvinyl chloride resin (produced by Xinjiang Zhongtai Chemical Co., Ltd., model SG-3), 29 g of chlorinated polyethylene resin (produced by Weifang Yaxing Chemical Co., Ltd., model CPE 135A), 12 g of the toughening and mildew-proof agent prepared in Example 1, and 8 g of additives (composed of 2 g of antioxidant 1076 and 6 g of stearic acid) were added to a mixer and mixed at 1200 r / min. After stirring for 5 min, the mixed raw materials were added to an extruder for melt blending and extrusion, and then cast onto a cooling roll to form a film through cooling and shaping. The thickness of the film was 50 μm, and it was wound up to obtain a polyvinyl chloride base film.

[0029] Example 6: A layer of the stain-resistant coating prepared in Example 2 was coated on the surface of the polyvinyl chloride base film prepared in Example 5 using an intaglio printing roller, and then placed in an oven at 100 °C for drying and curing. After taking it out, a high-toughness stain-resistant and mildew-proof decorative film was obtained. The contact angle of the surface coating in Example 6 was measured with a contact angle measuring instrument to be 157.3°, and a coating with a contact angle greater than 150° is a superhydrophobic coating, which endows the decorative film with excellent stain-resistant performance.

[0030] Comparative Example 1: In the preparation process of Example 5, only the toughening and mildew-proof agent was replaced with an equal amount of octyl isothiazolinone mildew-proof agent, and the other conditions remained unchanged to prepare a base film.

[0031] Comparative Example 2: A commercially available toughened polyvinyl chloride material (produced by Shanghai Chlor-Alkali Chemical Co., Ltd., model SC-800T) was used to prepare a film with a thickness of 50 μm by the casting method.

[0032] Comparative Example 3: In the preparation process of Example 5, chlorinated polyethylene resin was not added, and the other steps were the same as those in Example 5.

[0033] Examples 3, 4, and 5, and Comparative Examples 1, 2, and 3 were made into corresponding shapes according to different test standards for the following performance tests: The impact resistance was measured according to GB / T 9639-2008 "Test Method for Impact Resistance of Plastic Films and Sheets - Free Falling Dart Method"; The mildew-proof experiment was carried out according to the ASTM E1428-2015 standard and classified according to ISO 846-2019 "Evaluation of Plastics under the Action of Fungi and Bacteria"; the mildew-proof grade is 0-4, grade 0: no growth (no visible mold on the surface); grade 1: trace growth (mold coverage area < 10%); grade 2: medium growth (mold coverage area 10%-30%); grade 3: significant growth (mold coverage area 30%-60%); grade 4: severe growth (mold coverage area > 60%).

[0034] The measured results are shown in the following table:

[0035] As can be seen from the above table, the base film prepared in the embodiment of the present invention has higher impact resistance than the comparative example, which also reflects that the toughness of the embodiment is higher than that of the comparative example. Moreover, the base film of the embodiment has good mildew resistance. Using this base film and stain-resistant coating as raw materials for the decorative film can endow the decorative film with high toughness and mildew resistance. Therefore, the decorative film prepared by the present invention has important application value in the technical field of decorative films.

[0036] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0037] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology may make various modifications or supplements to the described specific embodiments or use similar ways to replace them, and all should fall within the protection scope of the present invention.

Claims

1. A high-toughness, stain-resistant and mildew-resistant decorative film, composed of a polyvinyl chloride-based film and a stain-resistant coating, characterized in that: The polyvinyl chloride film is composed of the following components in parts by weight: 77-89 parts of polyvinyl chloride resin, 21-29 parts of chlorinated polyethylene resin, 4-12 parts of toughening mildewproofing agent, and 4-8 parts of additives; Wherein, the toughened mildew inhibitor is prepared by the following steps: Step A1, add 2-aminothiazole, 3,5-dihydroxybenzoic acid and N,N-dimethylformamide into a flask, stir, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide, stir and react at room temperature for 8 hours, the reaction is completed, and a reaction product 1 is obtained; Step A2, pyridine and 1,10-dichlorodecane were added into a flask, stirred, and reacted at 70° C. for 6 h. The reaction was completed to obtain a reaction product 2; Step A3, add reaction product 1, reaction product 2 and anhydrous toluene into a flask, add sodium hydroxide solution dropwise at room temperature with stirring, and stir the mixture at 75°C for 5 hours. The reaction is completed to obtain a toughened mildew inhibitor.

2. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 1, characterized in that: In step A1, the ratio of 2-aminothiazole, 3,5-dihydroxybenzoic acid, N,N-dimethylformamide, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide is 9.9 g:15.4 g:100 mL:15.5 g.

3. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 1, characterized in that: In step A2, the ratio of pyridine to 1,10-dichlorodecane is 7.9 g:23.7 g.

4. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 1, characterized in that: In step A3, the ratio of reaction product 1, reaction product 2, anhydrous toluene and sodium hydroxide solution is 23.6 g: 52.3 g: 150 mL: 40 mL.

5. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 1, characterized in that: The additive is composed of an antioxidant and a lubricant in a mass ratio of 1:3; the antioxidant is a hindered phenol antioxidant; and the lubricant is one of oleamide, butyl stearate and stearic acid.

6. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 1, characterized in that: The anti-fouling coating is prepared by the following steps: Add hydrophobic silica to anhydrous ethanol, ultrasonically disperse for 15-30 minutes, and then mix with methyltrimethoxysilane, tridecafluorooctyltriethoxysilane and ethyl orthosilicate. After stirring evenly, slowly add hydrochloric acid solution and continue stirring. After stirring for 2-3 hours, a stain-resistant coating is obtained.

7. The high-toughness, stain-resistant and mildew-resistant decorative film according to claim 6, characterized in that: The usage ratio of the hydrophobic silica, anhydrous ethanol, methyltrimethoxysilane, tridecafluorooctyltriethoxysilane, ethyl orthosilicate and hydrochloric acid solution is 8.7 g:100 mL:56.2 g:3.6 g:5.1 g:5 mL.

8. The method for preparing a high-toughness, stain-resistant and mildew-resistant decorative film according to any one of claims 1 to 7, characterized in that: The following steps are involved: A layer of anti-fouling paint is coated on the surface of the polyvinyl chloride film using a gravure printing roller, and then placed in an oven at 100-120°C for drying and curing. After being taken out, a high-toughness, anti-fouling and anti-mildew decorative film is obtained.

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