Environment-friendly water-based release agent, water-based release film and implementation method of water-based release film

Abstract

The invention relates to the field of thin film materials, and particularly discloses an environment-friendly water-based release agent, a water-based release film and an implementation method of the water-based release film. The environment-friendly water-based release agent comprises modified acrylic resin and a coating composition which are matched with each other for use, the modified acrylic resin is prepared from the following raw materials: self-crosslinking acrylic resin, an acrylate copolymer and an antioxidant; the coating composition comprises the following raw materials: a hydroxyl acrylic acid copolymer dispersion, a water-based slipping wear-resistant agent, a curing agent, a water-based drier and deionized water. According to the water-based release film, the modified acrylic resin is used for prime coat, the acrylic resin is modified, the surface strength and the stability of the release film can be improved by matching the modified acrylic resin with the hydroxyl acrylic acid copolymer dispersion, and the parameters such as stripping force, fastness and stability of the water-based release film can reach the standards of an existing organic silicon release film; and meanwhile, only a very small amount of VOC waste gas is generated, so that the method is environment-friendly and low in cost.

Description

Technical Field

[0001] The present application relates to the field of film materials, and more specifically, to an environmentally friendly water-based release agent, a water-based release film and an implementation method thereof. Background Art

[0002] As an important functional film material, release film is widely used in electronics, packaging, printing, medical and other fields. Its main function is to provide an easy-to-peel surface without damaging the substrate to protect the surface quality of the product during processing, transportation and storage. Traditional release films mainly use silicone release agents and fluorine-containing release agents.

[0003] Silicone release agents dominate the release film field due to their excellent release properties and chemical stability. However, they produce volatile organic compounds (VOCs) during the production process, which not only pollute the environment but also increase the environmental protection costs of enterprises. In order to comply with increasingly stringent environmental regulations, enterprises need to invest a lot of money in the construction and operation of waste gas treatment facilities, which undoubtedly increases production costs and also puts higher requirements on production equipment and workshop environment.

[0004] Although fluorinated release agents are superior to silicone release agents in some aspects, such as lower surface energy and better chemical resistance, their high price limits their application in a wider range of fields. Fluorinated release agents are mainly used in high-end markets with extremely high performance requirements, such as the manufacture of high-end electronic products. However, their high cost and potential environmental problems (such as fluoride emissions) have also become factors restricting their development.

[0005] In view of the above problems, the development of a new release film that is environmentally friendly, cost-effective and has excellent performance has become an urgent need in the industry. Summary of the invention

[0006] In order to solve the above technical problems, the present application provides an environmentally friendly water-based release agent, a water-based release film and an implementation method thereof.

[0007] This application adopts the following technical solutions: In a first aspect, the present application provides an environmentally friendly water-based release agent, which includes a modified acrylic resin and a coating composition used in conjunction with each other; The raw materials of the modified acrylic resin include: self-crosslinking acrylic resin, acrylate copolymer, and antioxidant; The raw materials of the coating composition include hydroxy acrylic copolymer dispersion, water-based slip and wear resistance agent, curing agent, water-based drying agent and deionized water; The mass ratio of the modified acrylic resin to the coating composition is (75-104):(40-60).

[0008] Furthermore, the raw materials of the modified acrylic resin include, by weight: 30-50 parts of self-crosslinking acrylic resin, 1-4 parts of acrylate copolymer, and 1-3 parts of antioxidant.

[0009] Preferably, the composition comprises, by weight: 35-45 parts of self-crosslinking acrylic resin, 2-3 parts of acrylate copolymer, and 2-3 parts of antioxidant.

[0010] Furthermore, the modified acrylic resin is obtained by the following method: According to weight percentage, the self-crosslinking acrylic resin and the acrylate copolymer are mixed and stirred evenly, and then the antioxidant is added and mixed and stirred.

[0011] The modified acrylic resin obtained by the above method has the characteristic of spontaneously forming a cross-linked network structure, which can give the release film a higher cohesive strength and solvent resistance, thereby improving the stability and surface fastness of the release film. At the same time, the introduction of the acrylic ester copolymer helps to adjust the surface energy of the release film, so that it can effectively prevent the adhesion between the adhesive and the substrate while ensuring a good release effect.

[0012] Furthermore, the coating composition comprises, by weight: 70-90 parts of hydroxy acrylic copolymer dispersion; 1-3 parts of water-based slip and wear resistance agent; 1-3 parts of curing agent; 1-5 parts of water-based drying agent; 1-3 parts of water.

[0013] Preferably, the hydroxy acrylic copolymer dispersion comprises 75-85 parts; the aqueous slip and wear resistance agent comprises 1.5-2.5 parts; the curing agent comprises 1.5-2.5 parts; the aqueous drying agent comprises 1.5-2.5 parts; and the water comprises 1.5-2.5 parts.

[0014] Furthermore, the above-mentioned water-based slip and wear-resistant agent includes any one of polydimethylsiloxane, polyphenylmethylsiloxane and polyether-modified polydimethylsiloxane.

[0015] By selecting a suitable water-based slip and anti-wear agent, the wear resistance and anti-sticking effect of the release film surface can be increased, and in combination with the hydroxy acrylic copolymer dispersion, the release film has a lower release force. Preferably, the water-based slip and anti-wear agent is polydimethylsiloxane or polyphenylmethylsiloxane.

[0016] Furthermore, the curing agent is a low-volatile aliphatic polyisocyanate, and the isocyanate group value is 20-30%. By selecting a suitable curing agent, the bonding effect between the molecules of the hydroxy acrylic copolymer dispersion can be improved, thereby improving the stability of the release film under extreme conditions. Preferably, the isocyanate group value is 22-28%, and more preferably 24-27%; Furthermore, the aqueous drying agent is butyl acrylate or isobutyl acrylate.

[0017] By selecting a suitable water-based drying agent, the drying speed of the release film during production can be accelerated, so that the product can be produced on a coating machine or a printing press with a shorter drying tunnel, thereby improving the compatibility of the product on the equipment. It can also undergo copolymerization reaction with the hydroxylated acrylic copolymer dispersion at a temperature of 70-90°C in the drying tunnel, thereby improving the mechanical properties of the release film.

[0018] In a second aspect, the present application provides an environmentally friendly water-based release film, comprising a substrate and a release layer located on at least one side of the substrate, wherein the release layer comprises an adhesion layer and a curing layer; The adhesion layer is formed by coating the modified acrylic resin on the surface of the substrate and drying it; the curing layer is formed by mixing and stirring the raw materials of the coating composition and coating it on the adhesion layer; The modified acrylic resin and the coating composition are as shown in the environmentally friendly water-based release agent according to any one of claims 1 to 8.

[0019] In a third aspect, the present application provides a method for implementing the above-mentioned environmentally friendly water-based release film, which comprises: (1) mixing a self-crosslinking acrylic resin and an acrylic ester copolymer and adding an antioxidant, mixing and stirring the mixture to obtain a modified acrylic resin, and coating the modified acrylic resin on a substrate to form an adhesion layer; (2) The hydroxy acrylic copolymer dispersion, water-based slip and wear-resistant agent, curing agent, water-based drying agent and deionized water are uniformly mixed to obtain a coating liquid, and the coating liquid is applied to the surface of the adhesion layer to form a cured layer.

[0020] In the implementation process of the water-based release film in the above technical solution, the modified acrylic resin is first used as a primer and applied alone to the surface of the substrate to form an adhesion layer, which helps to improve the adhesion of the coating on the surface of the release film. After the adhesion layer is dried, a coating liquid formed by mixing specific components and proportions is applied on its surface, and after curing, an environmentally friendly water-based release film is formed.

[0021] In summary, this application has the following beneficial effects: The environmentally friendly water-based release agent provided by the present application is composed of a modified acrylic resin and a coating composition used in combination with each other. The hydroxy acrylic copolymer dispersion in the coating composition is used as a two-component water-based varnish to give the base film a release effect; by using the hydroxy acrylic copolymer dispersion in combination with other water-based components (such as water-based slip and wear-resistant agents, water-based drying agents), the release film does not produce a large amount of volatile organic compounds during the production process, and is pollution-free and environmentally friendly, and the production cost is greatly reduced. At the same time, by modifying the acrylic resin and combining it with the hydroxy acrylic copolymer dispersion, the surface strength and stability of the release film can be increased.

[0022] In the process of modifying acrylic resin, self-crosslinking acrylic resin and acrylate copolymer are mixed and stirred. The combination of the two makes the molecular chain relax at the molecular level to form a network structure, enhance the connection strength between small molecules, and thus improve the surface fastness of the release film.

[0023] The environmentally friendly water-based release film provided by the present application is primed with modified acrylic resin to improve the adhesion of the coating on the surface of the release film. The release film can be simply mixed and coated on the surface of the release film using a printing machine. The obtained environmentally friendly water-based release film can meet the standards of existing silicone release films in terms of peeling force, fastness, stability and other parameters, while greatly reducing the production cost and only requiring the treatment of a very small amount of VOC waste gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a photo 1 of the preparation process of the environmentally friendly water-based release film provided by the present application; Figure 2 This is a second photo of the preparation process of the environmentally friendly water-based release film provided by the present application; DETAILED DESCRIPTION

[0025] The embodiments of the present invention will be described in detail below in conjunction with examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. The specific conditions not specified in the examples are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0026] Some of the raw materials and their sources used in the implementation of this application are shown in Table 1: Table 1. Some raw materials and their sources The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0027] Example of preparation of raw materials This preparation example provides a modified acrylic resin, and the preparation method thereof is as follows: pour the self-crosslinking acrylic resin and the acrylic ester copolymer into a mixing container, stir them with a stirrer at 30-40 revolutions per minute for 10-15 minutes to fully stir them, and place them under normal atmospheric pressure and a temperature of 5-30 degrees Celsius for 24 hours.

[0028] Pour the antioxidant into the mixture of the self-crosslinking acrylic resin and the acrylic ester copolymer, stir the mixture for 5-10 minutes at 20-30 revolutions per minute using a stirrer to fully stir the mixture to obtain a modified acrylic resin.

[0029] Table 2. Raw material ratio of modified acrylic resin Comparative Preparation Example The preparation method of this comparative preparation example is consistent with the above preparation example, except that the raw material ratios of the components are as shown in Table 3: Table 3. Raw material ratio of modified acrylic resin Raw material (kg) Comparative Preparation Example 1 Comparative Preparation Example 2 Self-crosslinking acrylic resin 49 0 Acrylate copolymer 0 49 Antioxidants 2 2 Example

[0030] The first set of embodiments This group of embodiments provides an environmentally friendly water-based release film, which includes a substrate and a release layer located on at least one side of the substrate, wherein the release layer includes an adhesion layer and a curing layer; The preparation method comprises: 1. Material preparation: Prepare the materials according to the raw materials shown in Table 4, and use polyethylene film as the substrate; 2. Implementing the adhesion layer: dilute the modified acrylic resin obtained in the above embodiment with deionized water to a suitable viscosity, apply it on the substrate, and dry it; 3. Implement the curing layer: pour the water-based slip and wear-resistant agent, curing agent, water-based drying agent and deionized water into a mixing container, stir with a stirrer at 10 revolutions per minute for 5-10 minutes to mix them evenly, then slowly pour in the hydroxylated acrylic copolymer dispersion, speed up to 10-20 revolutions per minute and stir for 5-10 minutes to obtain a coating liquid; then apply the coating liquid to the surface of the adhesion layer by a coater or a printer, and dry in a drying oven at 70-90°C to obtain an environmentally friendly water-based release film.

[0031] Table 4. Raw material ratio of water-based release film The curing agent is a low-volatile aliphatic polyisocyanate with an isocyanate group value of 24%; the water-based drying agent is butyl acrylate; the water-based slip and wear-resistant agent is polydimethylsiloxane; and the modified acrylic resin is provided by Preparation Example 2.

[0032] Second Group of Embodiments The raw material ratio of this group of examples is consistent with that of Example 2, except that this group of examples uses modified acrylic resins provided by different preparation examples, as shown in Table 5: Table 5. Raw material ratio of water-based release film Embodiment 13 This embodiment provides an environmentally friendly water-based release film, and its preparation method is consistent with that of Example 2, except for the selection of raw materials, as shown in Table 6: Table 6. Components and ratios of raw materials Embodiment 14 This embodiment provides an environmentally friendly water-based release film, and its preparation method is consistent with that of Example 2, except for the selection of raw materials, as shown in Table 7: Table 7. Components and ratios of raw materials Embodiment 15 This embodiment provides an environmentally friendly water-based release film, and its preparation method is consistent with that of Example 2, except that the selection and proportion of raw materials are as shown in Table 8: Table 8. Components and ratios of raw materials Comparative Example The preparation method of this comparative example is consistent with that of the first group of examples, except for the selection and proportion of raw materials, as shown in Table 9: Table 9. Selection and proportion of raw materials The curing agent is a low-volatile aliphatic polyisocyanate with an isocyanate group value of 24%; the water-based drying agent is butyl acrylate; and the water-based slip and wear-resistant agent is polydimethylsiloxane.

[0033] Performance testing 1. Detection method The performance parameters of the water-based release films prepared in Examples 1-7 and Comparative Examples 1-5 were measured using the following methods.

[0034] Determination of the peeling force of release films Test standard GB / T27731 180° room temperature peeling force (20min) requirement: <0.45N / 25mm Determination of residual adhesion of release films Test standard GB / T27731 Residual adhesion requirement ≥90% Determination of the stability of release films Test standard GB / T27731 70° aging 180° room temperature peeling force (24h) requirement <0.6N / 25mm Determination of surface dynamic friction of release film Test standard GB / T1006 Non-coated surface dynamic friction coefficient COF requirement> 0.35 2. Test results The test results are shown in Table 10: Table 10. Performance test results As can be seen from Table 10, the release agents provided in Examples 1-7 of the present application all exhibit excellent peeling degree, residual adhesion, stability and surface dynamic friction coefficient, reaching the standards of existing silicone release films, while the amount of VOC waste gas in the production process is greatly reduced. Among them, Example 2 has the best effect.

[0035] By comparing Example 2 with Comparative Examples 1-4, it can be found that the modification method and content of the modified acrylic resin have a great influence on the peelability and stability of the release film. When the self-crosslinking acrylic resin is not added to the modified acrylic resin (Comparative Example 2), the residual adhesion and stability of the release film are significantly reduced; at the same time, when the acrylate copolymer is not added to the modified acrylic resin (Comparative Example 1), the release film also shows a reduction in residual adhesion and stability. This is mainly because the self-crosslinking acrylic resin and the acrylate copolymer can relax the molecular chain at the molecular level, form a network structure, and enhance the connection strength between small molecules; and when the amount of modified acrylic resin added is too much or too little (Comparative Examples 3-4), it will also affect the peelability, residual adhesion and stability of the release film.

[0036] By comparing Example 2 with Comparative Examples 5-7, it can be found that when the content of the hydroxylated acrylic copolymer dispersion is too much or too little (Comparative Examples 5-6), the COF performance of the release film is poor.

[0037] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An environmentally friendly water-based release agent, characterized in that: It includes a modified acrylic resin and a coating composition used in conjunction with each other; The raw materials of the modified acrylic resin include: self-crosslinking acrylic resin, acrylic ester copolymer, antioxidant; The raw materials of the coating composition include hydroxy acrylic copolymer dispersion, water-based slip and wear resistance agent, curing agent, water-based drying agent and deionized water; The mass ratio of the modified acrylic resin to the coating composition is (75-104):(40-60).

2. The environmentally friendly water-based release agent according to claim 1, characterized in that: The raw materials of the modified acrylic resin include, by weight: 30-50 parts of self-crosslinking acrylic resin, 1-4 parts of acrylate copolymer, and 1-3 parts of antioxidant.

3. The environmentally friendly water-based release agent according to claim 2, characterized in that: The modified acrylic resin is obtained by the following method: According to weight percentage, the self-crosslinking acrylic resin and the acrylate copolymer are mixed and stirred evenly, and then the antioxidant is added and mixed and stirred.

4. The environmentally friendly water-based release agent according to claim 1, characterized in that: The coating composition comprises, by weight: 70-90 parts of hydroxy acrylic copolymer dispersion; 1-3 parts of water-based slip and wear resistance agent; 1-3 parts of curing agent; 1-5 parts of water-based drying agent; 1-3 parts of water.

5. The environmentally friendly water-based release agent according to claim 4, characterized in that: The water-based slip-enhancing and wear-resistant agent includes any one of polydimethylsiloxane, polyphenylmethylsiloxane and polyether-modified polydimethylsiloxane.

6. The environmentally friendly water-based release agent according to claim 4, characterized in that: The curing agent is a low-volatile aliphatic polyisocyanate with an isocyanate value of 20-30%.

7. The environmentally friendly water-based release agent according to claim 4, characterized in that: The aqueous drying agent is butyl acrylate or isobutyl acrylate.

8. An environmentally friendly water-based release film, characterized in that: It includes a substrate and a release layer located on at least one side of the substrate, wherein the release layer includes an adhesion layer and a curing layer; The adhesion layer is formed by coating the modified acrylic resin on the surface of the substrate and drying it; the curing layer is formed by mixing and stirring the raw materials of the coating composition and coating it on the adhesion layer; The modified acrylic resin and the coating composition are as shown in the environmentally friendly water-based release agent according to any one of claims 1 to 7.

9. A method for implementing the environmentally friendly water-based release film according to claim 8, characterized in that: It includes: The self-crosslinking acrylic resin and the acrylic ester copolymer are mixed and stirred, and then an antioxidant is added, and the mixture is mixed and stirred evenly to obtain a modified acrylic resin, and the modified acrylic resin is coated on a substrate to form an adhesion layer; The hydroxy acrylic copolymer dispersion, water-based slip and wear-resistant agent, curing agent, water-based drying agent and deionized water are uniformly mixed to obtain a coating liquid, and the coating liquid is coated on the surface of the adhesion layer to form a cured layer.

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