Release paper EB curing coating for automotive trim leather and preparation method of release paper EB curing coating

Abstract

The invention belongs to the technical field of coatings, and provides a release paper EB curing coating for automotive trim leather and a preparation method of the release paper EB curing coating. The coating mainly comprises modified polyurethane, modified acrylic resin, rosin, an ultraviolet light absorber, an antioxidant and a plasticizer. The modified polyurethane is prepared by modifying polyol through a graft polymer, firstly, the polyol is subjected to graft acrylic acid modification, so that more polar functional groups are introduced, the reactivity and compatibility with isocyanate are enhanced, and the crosslinking density and weather resistance of the polyurethane are further improved through amination modification; according to the modified acrylic resin, functional groups are introduced to improve the crosslinking density, low-molecular-weight acrylic monomers are adopted for chemical modification, the physical and chemical characteristics of the resin are optimized, rosin added into the coating serves as a natural toughening agent, the adhesive force and the wear resistance of a coating are enhanced, and the coating has a good anti-corrosion effect. And an effective solution is provided for the surface treatment of the automotive trim leather.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings and relates to a release paper EB curing coating for automobile interior leather and a preparation method thereof. Background Art

[0002] Although traditional coatings and curing technologies have achieved some success in history, they have gradually exposed many shortcomings in meeting modern needs. Traditional curing technologies, including thermal curing and UV curing, have performed well in previous applications, but thermal curing requires higher temperatures to achieve coating curing, resulting in high energy consumption and increased production costs, while UV curing is highly dependent on light sources, affecting the uniformity and applicability of the coating. In addition, many traditional coatings contain volatile organic compounds (VOCs) during production and use. These harmful substances not only pollute the environment, but may also have a negative impact on the health of workers. In addition, the limitations of traditional curing coatings in wear resistance make it difficult to meet the needs of modern automotive interiors. Therefore, the development of new coatings to improve performance and shorten production cycles has become an important direction for the development of the industry.

[0003] In response to the above problems, electron beam (EB) curing technology, as an emerging curing method, has gradually begun to attract attention. EB curing technology uses high-energy electron beams to irradiate coatings containing unsaturated double bonds, thereby initiating the polymerization of the coating and achieving the purpose of coating curing. This rapid curing feature greatly improves production efficiency, reduces energy consumption in traditional methods, and also reduces environmental impact. Compared with traditional coatings, EB-cured coatings generally provide better weather resistance, making them perform better under various environmental conditions. Therefore, there is an urgent need to develop an EB-cured coating for release paper for automotive interior leather with good wear resistance and environmental protection. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an EB-cured coating for release paper for automotive interior leather and a preparation method thereof. The present invention adopts a graft copolymer modification method and amination to modify acrylic monomers, which not only improves the crosslinking density of polyurethane, but also enhances the mechanical strength of the coating. By introducing low molecular weight acrylic monomers, the crosslinking ability of acrylic resin is improved, thereby meeting the needs of actual production.

[0005] To achieve this object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing a release paper EB curing coating for automotive interior leather, the preparation method comprising: Step S1, after uniformly mixing the polyol and acrylic acid at a first stirring speed, heating to a first temperature, adding a first catalyst, and cooling to room temperature after sufficient reaction under the protection of an inert gas to obtain a graft-modified polyol; Step S2, heating the grafted modified polyol to a second temperature, adding an amination agent and a second catalyst in sequence, stirring at a second stirring speed, and cooling to room temperature after sufficient reaction under the protection of an inert gas to obtain an amination polyol; Step S3, mixing the amino polyol and the isocyanate uniformly, heating to a third temperature, adding a third catalyst, and cooling to room temperature after sufficient reaction under the protection of an inert gas to obtain a modified polyurethane; Step S4, after the acrylic acid monomer and the hydroxy acrylic resin are uniformly mixed at a first stirring speed, an amination reagent is added, and the mixture is heated to a second temperature. After sufficient reaction, a fourth catalyst is added, and the mixture is heated to a third temperature under the protection of an inert gas. After sufficient reaction, the mixture is cooled to room temperature to obtain a modified acrylic resin; Step S5, mixing the modified polyurethane and the modified acrylic resin, adding rosin and stirring at a second stirring speed, then adding an ultraviolet absorber, an antioxidant and a plasticizer, stirring evenly at the second stirring speed, and then coating the mixture on the surface of the release paper, and curing the mixture using an electron beam device to obtain an EB-cured coating for release paper for automotive interior leather.

[0006] By grafting active acrylic monomers, double bonds and polar groups are introduced into the molecular structure of polyols. These groups not only increase the reaction sites of the molecular chain, but also improve the subsequent reactivity with substances such as isocyanates, and promote the formation of higher crosslinking density. After the grafting reaction, branches will be formed in the molecular chain of the polyol, which can adjust the flexibility of the material and the compatibility with other components, avoid phase separation problems, enhance the uniformity and stability of the coating, and at the same time, the branches can provide more reaction sites, thereby participating in further crosslinking reactions during the curing process of the coating. These branches and reactive sites introduced by grafting make the molecular structure of the polyol more complex and more reactive. Free radicals are generated under the action of the initiator, and the free radicals attack the acrylic monomers, causing them to open double bonds to generate new active centers, and then react with hydroxyl groups or other functional groups on the polyols to form graft copolymers. The acrylic segments in the graft copolymers are reactive and can further react with isocyanate groups in the subsequent polyurethane synthesis process to generate a ternary system of polyol-acrylic acid-isocyanate. This multifunctional structure improves the crosslinking density and physical strength of the system.

[0007] The amino functional group is a very active nucleophilic group that can quickly react with the -NCO group of isocyanate to form a urea bond. This urea bond structure not only enhances the mechanical strength of the coating, but also increases the wear resistance of the coating. As a strong nucleophilic group, the introduction of the amino functional group can form a strong chemical bond between the polyol and the isocyanate, making the coating less likely to decompose when in contact with chemicals. Therefore, amino modification can improve the chemical corrosion resistance of the coating. During the curing process of the coating, the presence of the amino functional group can accelerate the cross-linking reaction and improve the cross-linking efficiency and overall performance of the coating.

[0008] The introduction of acrylic acid segments through graft copolymer modification can increase the reaction sites of polyols, while amination modification introduces highly reactive amino groups, allowing the material to react with isocyanates more quickly and effectively during the polyurethane synthesis process. On a chemical level, the acrylic acid monomer in the graft copolymer has an unsaturated double bond structure and can continue to participate in cross-linking in subsequent reactions. The amination polyol provides more amino groups, accelerating the reaction with the -NCO group, thereby further increasing the degree of cross-linking. The combination of the two greatly improves the cross-linking efficiency of the system, with faster reaction speeds and a tighter cross-linking network.

[0009] As a preferred technical solution of the present invention, in step S1, the feeding amount of the polyol is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0010] In some optional examples, the feeding amount of acrylic acid is 10-30% of the feeding amount of polyol, for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0011] In some optional examples, the first stirring speed is 300-400rpm, for example, it can be 300rpm, 310rpm, 320rpm, 330rpm, 340rpm, 350rpm, 360rpm, 370rpm, 380rpm, 390rpm or 400rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] In some optional instances, the first temperature is 120-150°C, for example, it can be 120°C, 123°C, 126°C, 129°C, 132°C, 135°C, 138°C, 141°C, 144°C, 147°C or 150°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] In some optional examples, the dosage of the first catalyst is 1-5% of the dosage of the polyol, for example, it can be 1.0%, 1.4%, 1.8%, 2.2%, 2.6%, 3.0%, 3.4%, 3.8%, 4.2%, 4.6% or 5.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] In some optional examples, the gas flow rate of the inert gas is 4-6 mL / min, for example, it can be 4.0 mL / min, 4.2 mL / min, 4.4 mL / min, 4.6 mL / min, 4.8 mL / min, 5.0 mL / min, 5.2 mL / min, 5.4 mL / min, 5.6 mL / min or 6.0 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] In some optional examples, the reaction time at the first temperature is 1-2h, for example, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] As a preferred technical solution of the present invention, in step S2, the feeding amount of the grafted modified polyol is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In some optional instances, the second temperature is 120-140°C, for example, it can be 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, 132°C, 134°C, 136°C, 138°C or 140°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In some optional examples, the amount of the aminating agent is 5-15% of the amount of the graft-modified polyol, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In some optional examples, the dosage of the second catalyst is 0.1-1% of the dosage of the graft-modified polyol, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In some optional examples, the second stirring speed is 200-300 rpm, for example, it can be 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm or 300 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In some optional examples, the gas flow rate of the inert gas is 4-6 mL / min, for example, it can be 4.0 mL / min, 4.2 mL / min, 4.4 mL / min, 4.6 mL / min, 4.8 mL / min, 5.0 mL / min, 5.2 mL / min, 5.4 mL / min, 5.6 mL / min or 6.0 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In some optional examples, the reaction time at the second temperature is 2-3h, for example, it can be 2.0h, 2.1h, 2.2h, 2.3h, 2.4h, 2.5h, 2.6h, 2.7h, 2.8h, 2.9h or 3.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] As a preferred technical solution of the present invention, in step S3, the feeding amount of the amino polyol is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] In some optional examples, the amount of isocyanate added is 80-90% of the amount of amino polyol added, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% or 90%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In some optional instances, the third temperature is 70-80°C, for example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] In some optional examples, the dosage of the third catalyst is 0.1-1% of the dosage of the amino polyol, for example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In some optional examples, the gas flow rate of the inert gas is 4-6 mL / min, for example, it can be 4.0 mL / min, 4.2 mL / min, 4.4 mL / min, 4.6 mL / min, 4.8 mL / min, 5.0 mL / min, 5.2 mL / min, 5.4 mL / min, 5.6 mL / min or 6.0 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] In some optional examples, the reaction time at the third temperature is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] As a preferred technical solution of the present invention, in step S4, the feeding amount of the acrylic acid monomer is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In some optional examples, the amount of the hydroxyl acrylic resin is 10-30% of the amount of the acrylic monomer, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] In some optional examples, the first stirring speed is 300-400rpm, for example, it can be 300rpm, 310rpm, 320rpm, 330rpm, 340rpm, 350rpm, 360rpm, 370rpm, 380rpm, 390rpm or 400rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] In some optional examples, the amount of the amination agent is 3-5% of the amount of the acrylic acid monomer, for example, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8% or 5.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In some optional instances, the second temperature is 120-140°C, for example, it can be 120°C, 122°C, 124°C, 126°C, 128°C, 130°C, 132°C, 134°C, 136°C, 138°C or 140°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In some optional examples, the reaction time at the second temperature is 2-4h, for example, it can be 2.0h, 2.2h, 2.4h, 2.6h, 2.8h, 3.0h, 3.2h, 3.4h, 3.6h, 3.8h or 4.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In some optional examples, the dosage of the fourth catalyst is 1-2% of the dosage of the acrylic acid monomer, for example, it can be 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In some optional examples, the gas flow rate of the inert gas is 4-6 mL / min, for example, it can be 4.0 mL / min, 4.2 mL / min, 4.4 mL / min, 4.6 mL / min, 4.8 mL / min, 5.0 mL / min, 5.2 mL / min, 5.4 mL / min, 5.6 mL / min or 6.0 mL / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In some optional instances, the third temperature is 70-80°C; for example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In some optional examples, the reaction time at the third temperature is 3-6h, for example, 3.0h, 3.3h, 3.6h, 3.9h, 4.2h, 4.5h, 4.8h, 5.1h, 5.4h, 5.7h or 6.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] As a preferred technical solution of the present invention, in step S5, the feeding amount of the modified polyurethane is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In some optional examples, the feeding amount of the modified acrylic resin is 40-60g, for example, it can be 40g, 42g, 44g, 46g, 48g, 50g, 52g, 54g, 56g, 58g or 60g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] In some optional examples, the amount of rosin added is 5-10g, for example, 5.0g, 5.5g, 6.0g, 6.5g, 7.0g, 7.5g, 8.0g, 8.5g, 9.0g, 9.5g or 10g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In some optional examples, the second stirring speed is 200-300 rpm, for example, it can be 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, 250 rpm, 260 rpm, 270 rpm, 280 rpm, 290 rpm or 300 rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In some optional examples, the dosage of the ultraviolet absorber is 1-3g, for example, it can be 1.0g, 1.2g, 1.4g, 1.6g, 1.8g, 2.0g, 2.2g, 2.4g, 2.6g, 2.8g or 3.0g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] In some optional examples, the dosage of the antioxidant is 0.5-2g, for example, it can be 0.5g, 0.6g, 0.7g, 0.8g, 0.9g, 1.0g, 1.1g, 1.2g, 1.3g, 1.4g, 1.5g, 1.6g, 1.7g, 1.8g, 1.9g or 2.0g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] In some optional examples, the amount of the plasticizer added is 5-10g, for example, 5.0g, 5.5g, 6.0g, 6.5g, 7.0g, 7.5g, 8.0g, 8.5g, 9.0g, 9.5g or 10g, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] In some optional examples, the coating thickness is 30-50 μm, for example, it can be 30 μm, 32 μm, 34 μm, 36 μm, 38 μm, 40 μm, 42 μm, 44 μm, 46 μm, 48 μm or 50 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In some optional instances, the irradiation dose of the electron beam device is 20-50 kGy, for example, it can be 20 kGy, 23 kGy, 26 kGy, 29 kGy, 32 kGy, 35 kGy, 38 kGy, 41 kGy, 44 kGy, 47 kGy or 50 kGy, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0048] In some optional instances, the irradiation speed of the electron beam device is 5-20 m / min, for example, it can be 5 m / min, 6 m / min, 7 m / min, 8 m / min, 9 m / min, 10 m / min, 11 m / min, 12 m / min, 13 m / min, 14 m / min, 15 m / min, 16 m / min, 17 m / min, 18 m / min, 19 m / min or 20 m / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] In some optional instances, the acceleration voltage of the electron beam device is 150-300kV, for example, it can be 150kV, 165kV, 180kV, 195kV, 210kV, 225kV, 240kV, 255kV, 270kV, 285kV or 300kV, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0050] In a second aspect, the present invention provides an EB-cured coating of release paper for automotive interior leather obtained by the preparation method described in the first aspect.

[0051] Compared with the prior art, the present invention has the following beneficial effects: (1) During the synthesis of modified polyurethane, isocyanate reacts with polyol to form linear or cross-linked polymer chains. The introduction of additional groups can increase the degree of cross-linking, thereby forming a more stable three-dimensional network structure. The flexibility of urethane enables the coating to deform under friction, thereby reducing wear, while the hardness of acrylic resin provides better surface protection, allowing the coating to maintain good friction properties under wear conditions and improve wear resistance; (2) EB curing technology generates a large number of free radicals through electron beam radiation, which can initiate the polymerization of unsaturated double bonds in modified acrylic resin. Modified acrylic resin usually contains a variety of functional groups, especially unsaturated acrylic monomers. Through electron beam irradiation, these monomers are rapidly polymerized into a polymer network. Through graft copolymerization and amination, the reactivity of polyurethane and acrylic resin is enhanced, allowing them to react and crosslink rapidly under EB irradiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A flow chart of a method for preparing an EB-curing coating of release paper for automotive interior leather provided in Examples 1-8 of the present invention; Figure 2 This is a SEM image of an EB-cured coating of a release paper for automotive interior leather prepared in Example 1 of the present invention (scale: 10 μm); Figure 3This is a SEM image of the EB-cured coating of release paper for automotive interior leather prepared in Example 1 of the present invention (scale: 2 μm). DETAILED DESCRIPTION

[0053] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0054] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products, and their brands, specifications and manufacturer information are as follows: Polybutylene adipate, purity ≥99%, Hubei Yongkuo Technology Co., Ltd.; Acrylic acid, purity ≥99%, Shandong Leli New Materials Co., Ltd.; Benzoyl peroxide, purity ≥99%, Hubei Lingyan Biotechnology Co., Ltd.; Nitrogen, purity ≥99%, CSSC (Handan) Perri Special Gas Co., Ltd.; Triethanolamine, purity ≥99%, Shanghai Puzhen Biotechnology Co., Ltd.; Triethylamine, purity ≥99%, Beijing Tianyu Kanghong Chemical Technology Co., Ltd.; Hexamethylene diisocyanate trimer, purity ≥99%, Hebei Yanxi Chemical Co., Ltd.; Diphenylmethane diisocyanate, purity ≥99%, Wuhan Xinzhongke Chemical Technology Co., Ltd.; Ethyl methacrylate, purity ≥99%, Shanghai Eon Chemical Technology Co., Ltd.; Hydroxylated acrylic resin, purity ≥99%, Baoji Didu Pharmaceutical Chemical Co., Ltd.; Azobisisobutyronitrile, purity ≥99%, Wuhan Jiyesheng Chemical Co., Ltd.; Rosin, purity ≥99%, Shenyang Elex Chemical Co., Ltd.; UV-0, purity ≥99%, Hubei Henglvyuan Technology Co., Ltd.; Antioxidant 1010, purity ≥99%, Qingdao Zhenguang Functional Materials Technology Co., Ltd.; Other raw materials can be purchased from the market.

[0055] Example 1

[0056] This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 60 g of poly(1,4-butylene adipate) and 12.0 g of acrylic acid were mixed uniformly at a speed of 320 rpm, heated to 130° C., 1.1 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.1 h under the protection of N2 at a flow rate of 4.3 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 57g of graft-modified polyol to 125°C, adding 5.2g of triethanolamine and 0.39g of triethylamine in sequence, stirring at 240rpm, and reacting for 2.6h under N2 protection at a flow rate of 4.3mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 60 g of amino polyol and 50.4 g of hexamethylene diisocyanate trimer were mixed evenly and heated to 77° C., 0.38 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.6 h under the protection of N2 at a flow rate of 4.3 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 59 g of ethyl methacrylate and 8.8 g of hydroxy acrylic resin are uniformly mixed at a speed of 330 rpm, 2.2 g of triethanolamine is added, and the mixture is heated to 126° C. and fully reacted for 2.6 h. Then, 0.8 g of benzoyl peroxide is added, and the mixture is heated to 73° C. under the protection of N2 at a flow rate of 4.3 mL / min, and fully reacted for 3.8 h before being cooled to room temperature to obtain a modified acrylic resin; Step S5, 58g of modified polyurethane and 44g of modified acrylic resin are mixed, 5.9g of rosin is added and stirred at a speed of 220rpm, and then 1.6g of UV-0, 0.8g of antioxidant 1010 and 6.2g of phthalate are added, and the mixture is stirred evenly at a speed of 220rpm and then coated on the surface of the release paper with a thickness of 36μm. The mixture is cured using an electron beam device with an irradiation dose of 28kGy, an irradiation speed of 10m / min, and an acceleration voltage of 150kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0057] Figure 2 , Figure 3 A release paper EB-cured coating for automotive interior leather prepared in this embodiment can be seen to have a compact and smooth surface.

[0058] Example 2

[0059] This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 55 g of poly(1,4-butylene adipate) and 12.1 g of acrylic acid were mixed uniformly at a speed of 350 rpm, heated to 141° C., 1.4 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.5 h under the protection of N2 at a flow rate of 4.8 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 61g of graft-modified polyol to 128°C, adding 5.1g of triethanolamine and 0.33g of triethylamine in sequence, stirring at 260rpm, and reacting for 2.2h under the protection of N2 at a flow rate of 4.8mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 64 g of amino polyol and 51.2 g of diphenylmethane diisocyanate were mixed evenly and heated to 76° C., 0.35 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.3 h under the protection of N2 at a flow rate of 4.8 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 56g of ethyl methacrylate and 12.6g of hydroxy acrylic resin are mixed uniformly at a speed of 360rpm, 2.3g of triethanolamine is added, and the mixture is heated to 122°C. After fully reacting for 3.1h, 0.67g of azobisisobutyronitrile is added, and the mixture is heated to 71°C under the protection of N2 at a flow rate of 4.8mL / min. After fully reacting for 4.5h, the mixture is cooled to room temperature to obtain a modified acrylic resin; Step S5, mix 62g of modified polyurethane and 49g of modified acrylic resin, add 6.3g of rosin and stir at a speed of 260rpm, then add 2.2g UV-0, 1.3g of antioxidant 1010 and 7.4g of phthalate, stir evenly at a speed of 260rpm, and then apply it on the surface of release paper with a thickness of 32μm. Use electron beam equipment for curing, the irradiation dose is 30kGy, the irradiation speed is 15m / min, and the acceleration voltage is 200kV to obtain EB-cured coating for release paper for automotive interior leather.

[0060] Example 3

[0061] This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 62 g of poly(1,4-butylene adipate) and 12.4 g of acrylic acid were mixed uniformly at a speed of 360 rpm, heated to 139° C., 2.1 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.7 h under the protection of N2 at a flow rate of 5.2 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 67g of grafted modified polyol to 136°C, adding 5.7g of triethanolamine and 0.46g of triethylamine in sequence, stirring at 230rpm, and reacting for 2.7h under the protection of N2 at a flow rate of 5.2mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 58 g of amino polyol and 48.7 g of diphenylmethane diisocyanate were mixed evenly and heated to 70° C., 0.42 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.5 h under the protection of N2 at a flow rate of 5.2 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 62g of ethyl methacrylate and 13.1g of hydroxy acrylic resin are mixed uniformly at a speed of 320rpm, 2.5g of triethanolamine is added, and the mixture is heated to 133°C. After fully reacting for 3.4h, 0.84g of azobisisobutyronitrile is added, and the mixture is heated to 75°C under the protection of N2 at a flow rate of 5.2mL / min. After fully reacting for 4.8h, the mixture is cooled to room temperature to obtain a modified acrylic resin; Step S5, 60g of modified polyurethane and 48g of modified acrylic resin are mixed, 7.2g of rosin is added and stirred at a speed of 230rpm, and then 2.1g of UV-0, 1.5g of antioxidant 1010 and 7.9g of styrene-acrylate are added, and the mixture is stirred evenly at a speed of 230rpm and then coated on the surface of release paper with a thickness of 40μm. The mixture is cured using an electron beam device with an irradiation dose of 35kGy, an irradiation speed of 7m / min, and an acceleration voltage of 150kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0062] Example 4 This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 58 g of poly(1,4-butylene adipate) and 11.1 g of acrylic acid were stirred and mixed at a speed of 300 rpm, and then heated to 143° C., 1.9 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.8 h under the protection of N2 at a flow rate of 5.1 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 66 g of grafted modified polyol to 135° C., adding 7.3 g of triethanolamine and 0.48 g of triethylamine in sequence, stirring at 280 rpm, and reacting for 2.4 h under the protection of N2 at a flow rate of 5.1 mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 63 g of amino polyol and 54.1 g of hexamethylene diisocyanate trimer were mixed evenly and heated to 72° C., 0.32 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.7 h under the protection of N2 at a flow rate of 5.2 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 56 g of ethyl methacrylate and 11.7 g of hydroxy acrylic resin are mixed uniformly at a speed of 370 rpm, 2.4 g of triethanolamine is added, the mixture is heated to 124° C., and fully reacted for 3.1 h, 0.72 g of benzoyl peroxide is added, and the mixture is heated to 78° C. under the protection of N2 at a flow rate of 5.1 mL / min, and fully reacted for 5.1 h before being cooled to room temperature to obtain a modified acrylic resin; Step S5, mixing 63g of modified polyurethane and 54g of modified acrylic resin, adding 8.4g of rosin and stirring at a speed of 260rpm, then adding 1.9g of UV-0, 1.1g of antioxidant 1010 and 7.3g of styrene-acrylate, stirring evenly at a speed of 260rpm, and then coating on the surface of release paper with a thickness of 35μm, using electron beam equipment for curing, the irradiation dose is 25kGy, the irradiation speed is 12m / min, and the acceleration voltage is 250kV, to obtain EB-cured coating for release paper for automotive interior leather.

[0063] Example 5 This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 67 g of poly(1,4-butylene adipate) and 12.7 g of acrylic acid were mixed uniformly at a speed of 370 rpm, heated to 126° C., 2.1 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.5 h under the protection of N2 at a flow rate of 5.6 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 59g of graft-modified polyol to 127°C, adding 7.6g of triethanolamine and 0.37g of triethylamine in sequence, mixing at a speed of 240rpm, and reacting for 2.8h under the protection of N2 at a flow rate of 5.6mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 61 g of amino polyol and 53.7 g of hexamethylene diisocyanate trimer were mixed evenly and heated to 76° C., 0.21 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.8 h under the protection of N2 at a flow rate of 5.6 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 62 g of ethyl methacrylate and 16.7 g of hydroxy acrylic resin are uniformly mixed at a speed of 330 rpm, 2.5 g of triethanolamine is added, and the mixture is heated to 132° C. and fully reacted for 3.6 h. Then, 0.86 g of benzoyl peroxide is added, and the mixture is heated to 74° C. under the protection of N2 at a flow rate of 5.6 mL / min, and fully reacted for 5.3 h before being cooled to room temperature to obtain a modified acrylic resin; Step S5, 61g of modified polyurethane and 50g of modified acrylic resin are mixed evenly, 7.6g of rosin is added and stirred at a speed of 240rpm until dissolved, and then 2.4g of UV-0, 1.6g of antioxidant 1010 and 8.3g of phthalate are added, and the mixture is stirred evenly at a speed of 240rpm and then coated on the surface of the release paper with a thickness of 45μm. The mixture is cured using an electron beam device with an irradiation dose of 40kGy, an irradiation speed of 10m / min, and an acceleration voltage of 200kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0064] Example 6 This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 70 g of poly(1,4-butylene adipate) and 18.9 g of acrylic acid were stirred uniformly at 350 rpm, heated to 142° C., 2.9 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.3 h under the protection of N2 at a flow rate of 4.7 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 68g of graft-modified polyol to 125°C, adding 5.7g of triethanolamine and 0.39g of triethylamine in sequence, stirring at 280rpm, and reacting for 2.1h under the protection of N2 at a flow rate of 4.7mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 62 g of amino polyol and 53.9 g of diphenylmethane diisocyanate were mixed evenly and heated to 72° C., 0.24 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.7 h under the protection of N2 at a flow rate of 4.7 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 66g of ethyl methacrylate and 16.5g of hydroxy acrylic resin are mixed uniformly at a speed of 360rpm, 2.7g of triethanolamine is added, and the mixture is heated to 131°C. After fully reacting for 3.0h, 0.99g of azobisisobutyronitrile is added, and the mixture is heated to 72°C under the protection of N2 at a flow rate of 4.7mL / min. After fully reacting for 5.1h, the mixture is cooled to room temperature to obtain a modified acrylic resin; Step S5, 54g of modified polyurethane and 46g of modified acrylic resin are mixed, 7.1g of rosin is added and stirred at a speed of 270rpm, and then 2.6g of UV-0, 0.9g of antioxidant 1010 and 5.7g of phthalate are added, and the mixture is stirred evenly at a speed of 270rpm and then coated on the surface of the release paper with a thickness of 38μm. The mixture is cured using an electron beam device with an irradiation dose of 35kGy, an irradiation speed of 14m / min, and an acceleration voltage of 180kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0065] Example 7 This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 56 g of poly(1,4-butylene adipate) and 10.6 g of acrylic acid were mixed uniformly at a speed of 330 rpm, heated to 138° C., 1.9 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.7 h under the protection of N2 at a flow rate of 4.3 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 61g of grafted modified polyol to 127°C, adding 7.3g of triethanolamine and 0.41g of triethylamine in sequence, stirring at 210rpm, and reacting for 2.7h under N2 protection at a flow rate of 4.3mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 57 g of amino polyol and 47.9 g of hexamethylene diisocyanate trimer were mixed evenly and heated to 73° C., 0.40 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.4 h under the protection of N2 at a flow rate of 4.3 mL / min, and then cooled to room temperature to obtain a modified polyurethane; Step S4, after 59 g of ethyl methacrylate and 15.3 g of hydroxy acrylic resin are uniformly mixed at a speed of 320 rpm, 2.0 g of triethanolamine is added, and the mixture is heated to 129° C. and fully reacted for 3.3 h. Then, 1.06 g of benzoyl peroxide is added, and the mixture is heated to 74° C. under the protection of N2 at a flow rate of 4.3 mL / min, and fully reacted for 3.7 h before being cooled to room temperature to obtain a modified acrylic resin; Step S5, 62g of modified polyurethane and 51g of modified acrylic resin are mixed, 8.3g of rosin is added and stirred at a speed of 230rpm, and then 1.8g of UV-0, 1.7g of antioxidant 1010 and 6.4g of styrene-acrylate are added, and the mixture is stirred evenly at a speed of 230rpm and then coated on the surface of the release paper with a thickness of 30μm. The mixture is cured using an electron beam device with an irradiation dose of 40kGy, an irradiation speed of 10m / min, and an acceleration voltage of 200kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0066] Example 8 This embodiment provides a method for preparing a release paper EB curing coating for automotive interior leather, such as Figure 1 As shown, the preparation method specifically comprises the following steps: Step S1, 62 g of poly(1,4-butylene adipate) and 13.0 g of acrylic acid were mixed uniformly at a speed of 370 rpm, heated to 137° C., 2.3 g of p-toluenesulfonic acid was added, and the mixture was fully reacted for 1.4 h under the protection of N2 at a flow rate of 5.3 mL / min, and then cooled to room temperature to obtain a graft-modified polyol; Step S2, heating 67g of grafted modified polyol to 134°C, adding 5.8g of triethanolamine and 0.42g of triethylamine in sequence, stirring at 260rpm, and reacting for 2.1h under the protection of N2 at a flow rate of 5.3mL / min, then cooling to room temperature to obtain amino polyol; Step S3, 63 g of amino polyol and 56.7 g of diphenylmethane diisocyanate were mixed evenly and heated to 70° C., 0.31 g of dibutyltin dilaurate was added, and the mixture was fully reacted for 1.7 h under the protection of N2 at a flow rate of 5.3 mL / min, and then cooled to room temperature to obtain amino polyol; Step S4, after 64 g of ethyl methacrylate and 14.7 g of hydroxy acrylic resin are mixed uniformly at a speed of 370 rpm, 2.6 g of triethanolamine is added, the mixture is heated to 124° C., and fully reacted for 3.6 h, 1.00 g of azobisisobutyronitrile is added, and the mixture is heated to 77° C. under the protection of N2 at a flow rate of 5.3 mL / min, and fully reacted for 4.5 h before being cooled to room temperature to obtain a modified acrylic resin; Step S5, 64g of modified polyurethane and 47g of modified acrylic resin are mixed, 6.4g of rosin is added and stirred at a speed of 210rpm, and then 2.2g of UV-0, 1.3g of antioxidant 1010 and 8.3g of phthalate are added, and the mixture is stirred evenly at a speed of 210rpm and then coated on the surface of the release paper with a thickness of 38μm. The mixture is cured using an electron beam device with an irradiation dose of 40kGy, an irradiation speed of 12m / min, and an acceleration voltage of 250kV to obtain an EB-cured coating for release paper for automotive interior leather.

[0067] Comparative Example 1 This embodiment provides an EB curing coating for release paper for automotive interior leather, which is different from Example 1 in that the feeding amount of acrylic acid in step S1 is adjusted to 21 g, and compared with Example 1, the feeding amount of acrylic acid in this embodiment is increased by 9 g, and the increased feeding amount is deducted from the proportion of poly(1,4-butylene adipate) and p-toluenesulfonic acid, so that the proportions of other components except acrylic acid remain unchanged. Other process parameters and operating conditions are exactly the same as those in Example 1.

[0068] Comparative Example 2 This embodiment provides an EB curing coating for release paper for automotive interior leather, which is different from Example 1 in that the feeding amount of acrylic acid in step S1 is adjusted to 3 g, and compared with Example 1, the feeding amount of acrylic acid in this embodiment is reduced by 9 g, and the reduced feeding amount is added to poly(1,4-butylene adipate) and p-toluenesulfonic acid in equal proportion, so that the ratio between other components except acrylic acid remains unchanged. Other process parameters and operating conditions are exactly the same as those in Example 1.

[0069] Comparative Example 3 This embodiment provides an EB curing coating for release paper for automotive interior leather, which is different from Example 1 in that the feeding amount of triethanolamine in step S2 is adjusted to 9.2 g, and compared with Example 1, the feeding amount of triethanolamine in this embodiment is increased by 4 g, and the increased feeding amount is deducted from the proportion of grafted modified polyol and triethylamine, so that the proportions of other components except triethanolamine remain unchanged. Other process parameters and operating conditions are exactly the same as those in Example 1.

[0070] Comparative Example 4 This embodiment provides an EB curing coating for release paper for automotive interior leather, which is different from Example 1 in that the feeding amount of triethanolamine in step S2 is adjusted to 1.2 g, and compared with Example 1, the feeding amount of triethanolamine in this embodiment is reduced by 4 g, and the reduced feeding amount is added to the grafted modified polyol and triethylamine in equal proportion, so that the ratio between the other components except triethanolamine remains unchanged. Other process parameters and operating conditions are exactly the same as those in Example 1.

[0071] The adhesion of the coating was tested according to the national standard GB / T 9286-2021; the hardness of the coating was tested according to GB / T 6739-2022; according to GB / T 1733-1993, the coating was placed in an environment of 90°C and 90% RH for 72 hours to test the hydrolysis resistance of the coating, and adhesion ≤ Level 2 was qualified; the denatured alcohol resistance was tested by mixing 99% anhydrous ethanol with 1% butanone by mass, and rubbing it with a cotton ball 10 times; sunlight simulation: according to DIN75220 standard, it was irradiated for 240 hours, and the adhesion after irradiation was ≤ Level 2, which was qualified. The test results are shown in Table 1.

[0072] Table 1 Test results of EB curing coating of release paper for automobile interior leather of Examples 1-8 and Comparative Examples 1-4

[0073] It can be seen from the test data of Example 1, Comparative Example 1 and Comparative Example 2 that the adhesion and sunlight simulation test performance of Comparative Example 1 are lower than those of Example 1, and the hardness is higher than that of Example 1; the adhesion, hardness, hydrolysis resistance, denatured alcohol resistance and sunlight simulation test performance of Comparative Example 2 are all lower than those of Example 1. This is because the excessive acrylic acid in Comparative Example 1 makes the coating surface too rigid, reducing the adhesion of the coating; in Comparative Example 2, due to the low content of acrylic acid, the cross-linking reaction is incomplete, thereby reducing the adhesion of the coating and the hardness of the coating. At the same time, the loose cross-linking structure increases the possibility of water molecule penetration, reducing the hydrolysis resistance of the coating.

[0074] It can be seen from the test data of Example 1, Comparative Example 3 and Comparative Example 4 that the adhesion and sunlight simulation test performance of Comparative Example 3 are lower than those of Example 1, and the hardness is higher than that of Example 1; the adhesion, hardness, hydrolysis resistance, denatured alcohol resistance and sunlight simulation test performance of Comparative Example 4 are all lower than those of Example 1. This is because the excessive amount of amination reagent in Comparative Example 3 increases the degree of crosslinking to form a denser network structure, increases the hardness of the coating and leads to reduced adhesion. In Comparative Example 4, due to the low content of amination reagent, the crosslinking reaction is insufficient, resulting in a loose structure of the coating, which reduces the adhesion, hardness and hydrolysis resistance of the coating.

[0075] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a release paper EB curing coating for automobile interior leather, characterized in that: The preparation method is: Step S1, after uniformly mixing the polyol and acrylic acid, heating to a first temperature, adding a first catalyst, and cooling to room temperature after sufficient reaction under the protection of an inert gas to obtain a graft-modified polyol; Step S2, heating the grafted modified polyol to a second temperature, adding an amination agent and a second catalyst in sequence, and cooling the temperature to room temperature after sufficient reaction under the protection of an inert gas to obtain an amination polyol; Step S3, mixing the amino polyol and the isocyanate uniformly, heating to a third temperature, adding a third catalyst, and cooling to room temperature after sufficient reaction under the protection of an inert gas to obtain a modified polyurethane; Step S4, after the acrylic acid monomer and the hydroxy acrylic resin are uniformly mixed, an amination reagent is added, and the mixture is heated to a second temperature. After sufficient reaction, a fourth catalyst is added, and the mixture is heated to a third temperature under the protection of an inert gas. After sufficient reaction, the mixture is cooled to room temperature to obtain a modified acrylic resin; Step S5, mixing the modified polyurethane and the modified acrylic resin, adding rosin and stirring, then adding an ultraviolet absorber, an antioxidant and a plasticizer, stirring evenly and coating them on the surface of the release paper, and curing them using an electron beam device to obtain an EB-cured coating for release paper for automotive interior leather.

2. The method for preparing a release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S1, The polyol is poly(1,4-butylene adipate), and the feeding amount is 50-70g; The feeding amount of the acrylic acid is 10-30% of the feeding amount of the polyol; The first temperature is 120-150° C. The first catalyst is p-toluenesulfonic acid, and the dosage is 1-5% of the polyol; The inert gas is N2, and the gas flow rate is 4-6 mL / min; The reaction time at the first temperature is 1-2h.

3. The method for preparing a release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S2, The feeding amount of the graft modified polyol is 50-70g; The second temperature is 120-140°C; The amination agent is triethanolamine, and the amount of the amination agent is 5-15% of the amount of the graft-modified polyol. The second catalyst is triethylamine, and the dosage is 0.1-1% of the dosage of the graft-modified polyol; The inert gas is N2, and the gas flow rate is 4-6 mL / min; The reaction time at the second temperature is 2-3h.

4. The method for preparing a release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S3, The feeding amount of the amino polyol is 50-70g; The isocyanate is hexamethylene diisocyanate trimer or diphenylmethane diisocyanate; The amount of the isocyanate is 80-90% of the amount of the amino polyol; The third temperature is 70-80°C; The third catalyst is dibutyltin dilaurate, and the dosage is 0.1-1% of the dosage of the amino polyol; The inert gas is N2, and the gas flow rate is 4-6 mL / min; The reaction time at the third temperature is 1-2h.

5. The method for preparing the release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S4, The acrylic acid monomer is ethyl methacrylate, and the feeding amount is 50-70g; The feed amount of the hydroxy acrylic resin is 10-30% of the feed amount of the acrylic acid monomer; The amination agent is triethanolamine, and the dosage is 3-5% of the dosage of acrylic acid monomer; The second temperature is 120-140°C; The reaction time at the second temperature is 2-4h.

6. The method for preparing the release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S4, The fourth catalyst is benzoyl peroxide or azobisisobutyronitrile, and the feed amount is 1-2% of the feed amount of acrylic acid monomer; The inert gas is N2, and the gas flow rate is 4-6 mL / min; The third temperature is 70-80°C; The reaction time at the third temperature is 3-6h.

7. The method for preparing the release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S5, The feeding amount of the modified polyurethane is 50-70g; The feeding amount of the modified acrylic resin is 40-60g; The feeding amount of the rosin is 5-10g.

8. The method for preparing the release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S5, The ultraviolet absorber is UV-0, and the dosage of the ultraviolet absorber is 1-3g; The antioxidant is antioxidant 1010, and the dosage is 0.5-2g; The plasticizer is phthalate or styrene-acrylate, and the dosage is 5-10g.

9. The method for preparing the release paper EB curing coating for automobile interior leather according to claim 1, characterized in that: In step S5, The coating thickness is 30-50 μm; The irradiation dose of the electron beam device is 20-50 kGy; The irradiation speed of the electron beam device is 5-20m / min; The accelerating voltage of the electron beam device is 150-300 kV.

10. An EB-curing coating for release paper for automobile interior leather prepared by the method for preparing an EB-curing coating for release paper for automobile interior leather according to any one of claims 1 to 9.

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