A release paper eb curing coating for automotive interior leather and a preparation method thereof

Abstract

The application belongs to the technical field of paint, and provides a release paper EB curing paint for automotive interior leather and a preparation method thereof. Main components of the paint include modified polyurethane, modified acrylic resin, rosin, ultraviolet absorber, antioxidant and plasticizer. The modified polyurethane is prepared by grafting polymer modification of polyol. First, the polyol is modified by grafting acrylic acid to introduce more polar functional groups, enhance the reactivity and compatibility with isocyanate, and further improve the crosslinking density and weather resistance of the polyurethane through amination modification. The modified acrylic resin improves the crosslinking density by introducing functional functional groups, and the physical and chemical properties of the resin are optimized by chemical modification of low molecular weight acrylic monomer. The added rosin in the paint serves as a natural toughening agent, enhances the adhesion and wear resistance of the coating, and provides an effective solution for the surface treatment of automotive interior leather.

Description

Technical Field

[0001] This invention belongs to the field of coating technology and relates to an EB curing coating for release paper used in automotive interior leather and its preparation method. Background Technology

[0002] While traditional coatings and curing technologies have achieved some success historically, they have gradually revealed numerous shortcomings in meeting modern demands. Traditional curing technologies, including thermosetting and UV curing, have performed well in past applications. However, thermosetting requires high temperatures for curing, leading to high energy consumption and increased production costs. UV curing, on the other hand, is highly dependent on the light source, affecting the uniformity and applicability of the coating. Furthermore, many traditional coatings contain volatile organic compounds (VOCs) during production and use. These harmful substances not only pollute the environment but may also negatively impact worker health. Additionally, the limitations of traditionally cured coatings in terms of abrasion resistance make them unsuitable for the demands of modern automotive interiors. Therefore, developing new coatings to improve performance and shorten production cycles has become an important direction for industry development.

[0003] To address the above issues, electron beam (EB) curing technology, as an emerging curing method, is gradually gaining attention. EB curing technology uses a high-energy electron beam to irradiate coatings containing unsaturated double bonds, initiating polymerization and achieving coating curing. This rapid curing characteristic significantly improves production efficiency, reduces energy consumption compared to traditional methods, and also reduces environmental impact. Compared to traditional coatings, EB-cured coatings typically offer better weather resistance, performing superiorly under various environmental conditions. Therefore, there is an urgent need to develop an EB-cured coating for release paper used in automotive interior leather that possesses excellent abrasion resistance and environmental friendliness. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an EB-cured release paper coating for automotive interior leather and its preparation method. The present invention employs a graft copolymer modification method and amylation to modify acrylic monomers, which not only increases 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 objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing EB curable coating for release paper used in automotive interior leather, wherein the preparation method comprises:

[0007] Step S1: After the polyol and acrylic acid are mixed evenly at the first stirring speed, the mixture is heated to the first temperature, the first catalyst is added, and after the reaction is fully carried out under the protection of an inert gas, the mixture is cooled to room temperature to obtain the grafted modified polyol.

[0008] Step S2: The grafted modified polyol is heated to a second temperature, and the aminated reagent and the second catalyst are added sequentially. The mixture is stirred at a second stirring speed. Under the protection of an inert gas, the mixture is allowed to react fully and then cooled to room temperature to obtain the aminated polyol.

[0009] Step S3: After the aminated polyol and isocyanate are mixed evenly, the mixture is heated to a third temperature, a third catalyst is added, and the mixture is allowed to react fully under the protection of an inert gas and then cooled to room temperature to obtain the modified polyurethane.

[0010] Step S4: After the acrylic monomer and hydroxy acrylic resin are mixed evenly at the first stirring speed, an amination agent is added, the mixture is heated to the second temperature, and after the reaction is complete, a fourth catalyst is added, and the mixture is heated to the third temperature under inert gas protection. After the reaction is complete, the mixture is cooled to room temperature to obtain the modified acrylic resin.

[0011] Step S5: Mix the modified polyurethane and modified acrylic resin, add rosin and stir at the second stirring speed, then add ultraviolet absorber, antioxidant and plasticizer, stir evenly at the second stirring speed and then coat it on the surface of release paper, and use an electron beam device to cure it to obtain an EB curing coating for release paper of automotive interior leather.

[0012] By grafting reactive acrylic monomers, double bonds and polar groups are introduced into the polyol molecular structure. These groups not only increase the reaction sites of the molecular chain but also enhance the subsequent reactivity with substances such as isocyanates, promoting higher crosslinking density. After the grafting reaction, branches are formed in the polyol molecular chain, which can regulate the flexibility and compatibility with other components, avoid phase separation problems, and enhance the uniformity and stability of the coating. At the same time, the branches provide more reaction sites, thus participating in further crosslinking reactions during the curing process of the coating. These branches and reactive sites introduced through grafting make the polyol molecular structure more complex and its reactivity stronger. Under the action of an initiator, free radicals are generated. These free radicals attack the acrylic monomers, causing them to open double bonds and generate new active centers, which then react with hydroxyl groups or other functional groups on the polyol 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.

[0013] The amino functional group is a highly reactive nucleophilic group that can rapidly 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 its abrasion resistance. As a strong nucleophile, the introduction of the amino functional group enables the formation of strong chemical bonds between polyols and isocyanates, making the coating less prone to decomposition upon contact with chemicals. Therefore, amine modification can improve the chemical corrosion resistance of the coating. During the coating curing process, the presence of the amino functional group accelerates the crosslinking reaction, improving the crosslinking efficiency and overall performance of the coating.

[0014] Introducing acrylic acid segments through graft copolymerization increases the reaction sites of polyols, while amination modification introduces highly reactive amino groups, enabling the material to react more rapidly and effectively with isocyanates during polyurethane synthesis. Chemically, the acrylic acid monomers in the graft copolymer possess unsaturated double bonds, allowing them to continue participating in crosslinking in subsequent reactions. The amination-modified polyol provides more amino groups, accelerating the reaction with -NCO groups and further increasing the degree of crosslinking. The combination of these two methods significantly improves the crosslinking efficiency of the system, resulting in faster reaction rates and a more compact crosslinked network.

[0015] As a preferred technical solution of the present invention, in step S1, the amount of polyol fed is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] In some optional instances, the amount of acrylic acid fed is 10-30% of the amount of polyol fed, 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 this range are also applicable.

[0017] In some optional instances, the first stirring speed is 300-400 rpm, for example, it can be 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm, 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm or 400 rpm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0018] In some alternative instances, the first temperature is 120-150°C, such as 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; other unlisted values ​​within this range are also applicable.

[0019] In some optional instances, the amount of the first catalyst is 1-5% of the amount of 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, other unlisted values ​​within this range are also applicable.

[0020] In some alternative instances, the inert gas flow rate 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, other unlisted values ​​within this range are also applicable.

[0021] In some alternative instances, the reaction time at the first temperature is 1-2 hours, for example, 1.0 hours, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, or 2.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0022] As a preferred technical solution of the present invention, in step S2, the amount of grafted modified polyol is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0023] In some alternative instances, the second temperature is 120-140°C, such as 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; other unlisted values ​​within this range are also applicable.

[0024] In some optional instances, the amount of the amination reagent is 5-15% of the amount of the grafted 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 this range are also applicable.

[0025] In some optional instances, the amount of the second catalyst is 0.1-1% of the amount of the grafted 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, other unlisted values ​​within this range are also applicable.

[0026] In some optional instances, the second stirring speed is 200-300 rpm, for example, 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 this range are also applicable.

[0027] In some alternative instances, the inert gas flow rate 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, other unlisted values ​​within this range are also applicable.

[0028] In some alternative instances, the reaction time at the second temperature is 2-3 hours, for example, 2.0 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.7 hours, 2.8 hours, 2.9 hours, or 3.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0029] As a preferred technical solution of the present invention, in step S3, the amount of the aminated polyol is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] In some optional instances, the amount of isocyanate fed is 80-90% of the amount of aminated polyol fed, 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 this range are also applicable.

[0031] 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, other unlisted values ​​within this range are also applicable.

[0032] In some optional instances, the amount of the third catalyst is 0.1-1% of the amount of the aminated 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, other unlisted values ​​within this range are also applicable.

[0033] In some alternative instances, the inert gas flow rate 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, other unlisted values ​​within this range are also applicable.

[0034] In some optional instances, the reaction time at the third temperature is 1-2 hours, for example, 1.0 hours, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, or 2.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0035] As a preferred technical solution of the present invention, in step S4, the amount of acrylic monomer fed is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] In some optional examples, the amount of hydroxy acrylic resin fed is 10-30% of the amount of acrylic monomer fed, 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 this range are also applicable.

[0037] In some optional instances, the first stirring speed is 300-400 rpm, for example, it can be 300 rpm, 310 rpm, 320 rpm, 330 rpm, 340 rpm, 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm or 400 rpm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0038] In some optional instances, the amount of the amination reagent is 3-5% of the amount of acrylic acid monomer, for example, it can be 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, other unlisted values ​​within this range are also applicable.

[0039] In some alternative instances, the second temperature is 120-140°C, such as 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; other unlisted values ​​within this range are also applicable.

[0040] In some alternative instances, the reaction time at the second temperature is 2-4 hours, for example, 2.0 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, or 4.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0041] In some optional instances, the amount of the fourth catalyst is 1-2% of the amount of 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, other unlisted values ​​within this range are also applicable.

[0042] In some alternative instances, the inert gas flow rate 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, other unlisted values ​​within this range are also applicable.

[0043] 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 this range are also applicable.

[0044] In some alternative instances, the reaction time at the third temperature is 3-6 hours, for example, 3.0 hours, 3.3 hours, 3.6 hours, 3.9 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5.1 hours, 5.4 hours, 5.7 hours, or 6.0 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0045] As a preferred technical solution of the present invention, in step S5, the amount of modified polyurethane fed is 50-70g, for example, it can be 50g, 52g, 54g, 56g, 58g, 60g, 62g, 64g, 66g, 68g or 70g, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] In some optional instances, the amount of modified acrylic resin fed is 40-60g, for example, 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 this range are also applicable.

[0047] In some alternative instances, 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 this range are also applicable.

[0048] In some optional instances, the second stirring speed is 200-300 rpm, for example, 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 this range are also applicable.

[0049] In some alternative examples, the amount of the ultraviolet absorber is 1-3g, for example, 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 this range are also applicable.

[0050] In some alternative examples, the amount of antioxidant is 0.5-2g, for example, 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 this range are also applicable.

[0051] In some alternative instances, the amount of 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 this range are also applicable.

[0052] In some optional instances, 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, other unlisted values ​​within this range are also applicable.

[0053] In some alternative instances, the irradiation dose of the electron beam device is 20-50 kGy, for example, 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; other unlisted values ​​within this range are also applicable.

[0054] In some alternative instances, the irradiation rate 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, other unlisted values ​​within this range are also applicable.

[0055] In some alternative instances, the accelerating voltage of the electron beam device is 150-300kV, for example, 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 this range are also applicable.

[0056] Secondly, the present invention provides an EB-cured release paper coating for automotive interior leather obtained by the preparation method described in the first aspect.

[0057] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0058] (1) In the process of synthesizing modified polyurethane, isocyanate reacts with polyol to form linear or cross-linked polymer chains. Introducing additional groups can increase the degree of cross-linking, thereby forming a more stable three-dimensional network structure. The flexibility of urethane allows the coating to deform under friction, thereby reducing wear, while the hardness of acrylic resin provides better surface protection, enabling the coating to maintain good friction characteristics under wear conditions and improve wear resistance.

[0059] (2) Electron beam curing technology generates a large number of free radicals through electron beam irradiation. These free radicals can initiate the polymerization of unsaturated double bonds in modified acrylic resins. Modified acrylic resins typically contain a variety of functional groups, especially unsaturated acrylic monomers. Through electron beam irradiation, these monomers rapidly polymerize into a polymer network. By grafting copolymers and amylation, the reactivity of polyurethane and acrylic resins is enhanced, enabling them to react and crosslink rapidly under EB irradiation. Attached Figure Description

[0060] Figure 1 This is a flowchart illustrating a method for preparing an EB-cured release paper coating for automotive interior leather, as provided in Examples 1-8 of this invention.

[0061] Figure 2 SEM image (scale bar: 10 μm) of an EB-cured coating for automotive interior leather release paper prepared in Example 1 of the present invention.

[0062] Figure 3 This is a SEM image (scale bar: 2μm) of an EB-cured coating for automotive interior leather release paper prepared in Example 1 of the present invention. Detailed Implementation

[0063] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0064] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products, and their brand names, specifications, and manufacturer information are as follows:

[0065] Poly(1,4-butanediol adipate), purity ≥99%, Hubei Yongkuo Technology Co., Ltd.

[0066] Acrylic acid, purity ≥99%, Shandong Leli New Materials Co., Ltd.

[0067] Benzoyl peroxide, purity ≥99%, Hubei Lingyan Biotechnology Co., Ltd.

[0068] Nitrogen, purity ≥99%, provided by China Shipbuilding (Handan) Parex Special Gases Co., Ltd.

[0069] Triethanolamine, purity ≥99%, Shanghai Puzhen Biotechnology Co., Ltd.;

[0070] Triethylamine, purity ≥99%, Beijing Tianyu Kanghong Chemical Technology Co., Ltd.;

[0071] Hexamethylene diisocyanate trimer, purity ≥99%, Hebei Yanxi Chemical Co., Ltd.

[0072] Diphenylmethane diisocyanate, purity ≥99%, Wuhan Xinzhongke Chemical Technology Co., Ltd.;

[0073] Ethyl methacrylate, purity ≥99%, Shanghai Yi'en Chemical Technology Co., Ltd.

[0074] Hydroxyacrylate resin, purity ≥99%, Baoji Didu Pharmaceutical Chemical Co., Ltd.

[0075] Azobisisobutyronitrile (AIBN), purity ≥99%, Wuhan Jiyesheng Chemical Co., Ltd.

[0076] Rosin, purity ≥99%, Shenyang Elepx Chemical Co., Ltd.;

[0077] UV-0, purity ≥99%, Hubei Henglvyuan Technology Co., Ltd.

[0078] Antioxidant 1010, purity ≥99%, Qingdao Zhenguang Functional Materials Technology Co., Ltd.;

[0079] All other raw materials can be purchased on the market.

[0080] Example 1

[0081] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0082] Step S1: 60g of poly(1,4-butanediol adipate) and 12.0g of acrylic acid were mixed evenly at 320rpm, heated to 130℃, and 1.1g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 4.3mL / min, the mixture was allowed to react completely for 1.1h and then cooled to room temperature to obtain the grafted modified polyol.

[0083] In step S2, 57g of grafted modified polyol was heated to 125℃, and 5.2g of triethanolamine and 0.39g of triethylamine were added sequentially. The mixture was stirred at 240rpm and reacted completely for 2.6h under N2 protection at a flow rate of 4.3mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0084] Step S3: Mix 60g of aminated polyol with 50.4g of hexamethylene diisocyanate trimer evenly and heat to 77°C. Add 0.38g of dibutyltin dilaurate and react fully for 1.6h under N2 protection at a flow rate of 4.3mL / min. Then cool to room temperature to obtain modified polyurethane.

[0085] Step S4: Mix 59g of ethyl methacrylate and 8.8g of hydroxyl acrylic resin at 330rpm until homogeneous, add 2.2g of triethanolamine, heat to 126℃, and react for 2.6h. Then add 0.8g of benzoyl peroxide, and under N2 protection at a flow rate of 4.3mL / min, heat to 73℃ and react for 3.8h. Then cool to room temperature to obtain modified acrylic resin.

[0086] In step S5, 58g of modified polyurethane and 44g of modified acrylic resin are mixed, 5.9g of rosin is added and stirred at 220rpm, then 1.6g of UV-0, 0.8g of antioxidant 1010 and 6.2g of phthalate are added and stirred evenly at 220rpm. The mixture is then coated onto the surface of release paper with a thickness of 36μm and cured using an electron beam device with an irradiation dose of 28kGy, an irradiation rate of 10m / min and an accelerating voltage of 150kV to obtain the EB curable coating for release paper used in automotive interior leather.

[0087] Figure 2 , Figure 3 An EB-cured release paper coating for automotive interior leather prepared for this embodiment shows that the surface of the prepared coating is tight and smooth.

[0088] Example 2

[0089] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0090] Step S1: Mix 55g of poly(1,4-butanediol adipate) and 12.1g of acrylic acid at 350rpm until homogeneous, heat to 141℃, add 1.4g of p-toluenesulfonic acid, and react fully for 1.5h under N2 protection at a flow rate of 4.8mL / min, then cool to room temperature to obtain grafted modified polyol.

[0091] In step S2, 61g of grafted modified polyol was heated to 128℃, and 5.1g of triethanolamine and 0.33g of triethylamine were added sequentially. The mixture was stirred at 260rpm and reacted completely for 2.2h under N2 protection at a flow rate of 4.8mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0092] Step S3: Mix 64g of aminated polyol with 51.2g of diphenylmethane diisocyanate and heat to 76°C. Add 0.35g of dibutyltin dilaurate and react for 1.3h under N2 protection at a flow rate of 4.8mL / min. Then cool to room temperature to obtain modified polyurethane.

[0093] In step S4, 56g of ethyl methacrylate and 12.6g of hydroxyl acrylic resin were mixed evenly at 360rpm, 2.3g of triethanolamine was added, and the mixture was heated to 122℃ and reacted completely for 3.1h. Then, 0.67g of azobisisobutyronitrile was added, and the mixture was heated to 71℃ under N2 protection at a flow rate of 4.8mL / min and reacted completely for 4.5h. The mixture was then cooled to room temperature to obtain the modified acrylic resin.

[0094] In step S5, 62g of modified polyurethane and 49g of modified acrylic resin are mixed, 6.3g of rosin is added and stirred at 260rpm, then 2.2g of UV-0, 1.3g of antioxidant 1010 and 7.4g of phthalate are added and stirred evenly at 260rpm. The mixture is then coated onto the surface of release paper with a thickness of 32μm and cured using an electron beam device with an irradiation dose of 30kGy, an irradiation rate of 15m / min and an accelerating voltage of 200kV to obtain the EB curable coating for release paper used in automotive interior leather.

[0095] Example 3

[0096] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0097] Step S1: 62g of poly(1,4-butanediol adipate) and 12.4g of acrylic acid were mixed evenly at 360 rpm, heated to 139°C, and 2.1g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 5.2 mL / min, the mixture was allowed to react for 1.7 h and then cooled to room temperature to obtain the grafted modified polyol.

[0098] In step S2, 67g of grafted modified polyol was heated to 136℃, and 5.7g of triethanolamine and 0.46g of triethylamine were added sequentially. The mixture was stirred at 230rpm and reacted completely for 2.7h under N2 protection at a flow rate of 5.2mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0099] Step S3: Mix 58g of aminated polyol with 48.7g of diphenylmethane diisocyanate and heat to 70°C. Add 0.42g of dibutyltin dilaurate and react for 1.5h under N2 protection at a flow rate of 5.2mL / min. Then cool to room temperature to obtain modified polyurethane.

[0100] In step S4, 62g of ethyl methacrylate and 13.1g of hydroxyl acrylic resin were mixed evenly at 320rpm, 2.5g of triethanolamine was added, and the mixture was heated to 133℃ and reacted completely for 3.4h. Then, 0.84g of azobisisobutyronitrile was added, and the mixture was heated to 75℃ under N2 protection at a flow rate of 5.2mL / min and reacted completely for 4.8h. The mixture was then cooled to room temperature to obtain the modified acrylic resin.

[0101] Step S5: Mix 60g of modified polyurethane and 48g of modified acrylic resin, add 7.2g of rosin and stir at 230rpm, then add 2.1g of UV-0, 1.5g of antioxidant 1010 and 7.9g of styrene-acrylate, stir evenly at 230rpm and coat it on the surface of release paper with a thickness of 40μm. Curing is performed using an electron beam device with an irradiation dose of 35kGy, an irradiation rate of 7m / min and an accelerating voltage of 150kV to obtain the EB curing coating for release paper of automotive interior leather.

[0102] Example 4

[0103] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0104] Step S1: 58g of poly(1,4-butanediol adipate) and 11.1g of acrylic acid were stirred and mixed evenly at 300rpm, heated to 143℃, and 1.9g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 5.1mL / min, the mixture was reacted completely for 1.8h and then cooled to room temperature to obtain the grafted modified polyol.

[0105] In step S2, 66g of grafted modified polyol was heated to 135℃, and 7.3g of triethanolamine and 0.48g of triethylamine were added sequentially. The mixture was stirred at 280rpm and reacted completely for 2.4h under N2 protection at a flow rate of 5.1mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0106] Step S3: Mix 63g of aminated polyol with 54.1g of hexamethylene diisocyanate trimer and heat to 72°C. Add 0.32g of dibutyltin dilaurate and react for 1.7h under N2 protection at a flow rate of 5.2mL / min. Then cool to room temperature to obtain modified polyurethane.

[0107] In step S4, 56g of ethyl methacrylate and 11.7g of hydroxyl acrylic resin were mixed evenly at 370rpm, then 2.4g of triethanolamine was added, and the mixture was heated to 124℃ and reacted completely for 3.1h. Then, 0.72g of benzoyl peroxide was added, and the mixture was heated to 78℃ under N2 protection at a flow rate of 5.1mL / min and reacted completely for 5.1h. The mixture was then cooled to room temperature to obtain the modified acrylic resin.

[0108] Step S5: Mix 63g of modified polyurethane and 54g of modified acrylic resin, add 8.4g of rosin and stir at 260rpm, then add 1.9g of UV-0, 1.1g of antioxidant 1010 and 7.3g of styrene-acrylate, stir evenly at 260rpm and coat it on the surface of release paper with a thickness of 35μm. Curing is performed using an electron beam device with an irradiation dose of 25kGy, an irradiation rate of 12m / min and an accelerating voltage of 250kV to obtain the EB curing coating for release paper of automotive interior leather.

[0109] Example 5

[0110] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0111] Step S1: 67g of poly(1,4-butanediol adipate) and 12.7g of acrylic acid were mixed evenly at 370 rpm, heated to 126°C, and 2.1g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 5.6 mL / min, the mixture was allowed to react for 1.5 h and then cooled to room temperature to obtain the grafted modified polyol.

[0112] In step S2, 59g of grafted modified polyol was heated to 127℃, and 7.6g of triethanolamine and 0.37g of triethylamine were added sequentially. The mixture was stirred evenly at 240rpm and allowed to react completely for 2.8h under N2 protection at a flow rate of 5.6mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0113] Step S3: Mix 61g of aminated polyol with 53.7g of hexamethylene diisocyanate trimer evenly and heat to 76℃. Add 0.21g of dibutyltin dilaurate and react fully for 1.8h under N2 protection at a flow rate of 5.6mL / min. Then cool to room temperature to obtain modified polyurethane.

[0114] In step S4, 62g of ethyl methacrylate and 16.7g of hydroxyl acrylic resin were mixed evenly at 330rpm, 2.5g of triethanolamine was added, and the mixture was heated to 132℃ and reacted completely for 3.6h. Then, 0.86g of benzoyl peroxide was added, and the mixture was heated to 74℃ under N2 protection at a flow rate of 5.6mL / min and reacted completely for 5.3h. The mixture was then cooled to room temperature to obtain the modified acrylic resin.

[0115] Step S5: Mix 61g of modified polyurethane and 50g of modified acrylic resin evenly, add 7.6g of rosin and stir at 240rpm until dissolved, then add 2.4g of UV-0, 1.6g of antioxidant 1010 and 8.3g of phthalate, stir evenly at 240rpm and coat it on the surface of release paper with a thickness of 45μm. Curing is performed using an electron beam device with an irradiation dose of 40kGy, an irradiation rate of 10m / min and an accelerating voltage of 200kV to obtain the EB curing coating for release paper of automotive interior leather.

[0116] Example 6

[0117] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0118] Step S1: 70g of poly(1,4-butanediol adipate) and 18.9g of acrylic acid were stirred at 350 rpm until homogeneous, heated to 142°C, and 2.9g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 4.7 mL / min, the mixture was allowed to react completely for 1.3 h and then cooled to room temperature to obtain the grafted modified polyol.

[0119] In step S2, 68g of grafted modified polyol was heated to 125℃, and 5.7g of triethanolamine and 0.39g of triethylamine were added sequentially. The mixture was stirred at 280rpm and reacted completely for 2.1h under N2 protection at a flow rate of 4.7mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0120] Step S3: Mix 62g of aminated polyol with 53.9g of diphenylmethane diisocyanate and heat to 72°C. Add 0.24g of dibutyltin dilaurate and react for 1.7h under N2 protection at a flow rate of 4.7mL / min. Then cool to room temperature to obtain modified polyurethane.

[0121] In step S4, 66g of ethyl methacrylate and 16.5g of hydroxyl acrylic resin were mixed evenly at 360rpm, 2.7g of triethanolamine was added, and the mixture was heated to 131℃ and reacted completely for 3.0h. Then, 0.99g of azobisisobutyronitrile was added, and the mixture was heated to 72℃ under N2 protection at a flow rate of 4.7mL / min and reacted completely for 5.1h. The mixture was then cooled to room temperature to obtain the modified acrylic resin.

[0122] In step S5, 54g of modified polyurethane and 46g of modified acrylic resin are mixed, 7.1g of rosin is added and stirred at 270rpm, then 2.6g of UV-0, 0.9g of antioxidant 1010 and 5.7g of phthalate are added and stirred evenly at 270rpm. The mixture is then coated onto the surface of release paper with a thickness of 38μm and cured using an electron beam device with an irradiation dose of 35kGy, an irradiation rate of 14m / min and an accelerating voltage of 180kV to obtain the EB curable coating for release paper used in automotive interior leather.

[0123] Example 7

[0124] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0125] Step S1: 56g of poly(1,4-butanediol adipate) and 10.6g of acrylic acid were mixed evenly at 330 rpm, heated to 138°C, and 1.9g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 4.3 mL / min, the mixture was allowed to react completely for 1.7 h and then cooled to room temperature to obtain the grafted modified polyol.

[0126] In step S2, 61g of grafted modified polyol was heated to 127°C, and 7.3g of triethanolamine and 0.41g of triethylamine were added sequentially. The mixture was stirred at 210 rpm and reacted completely for 2.7 h under N2 protection at a flow rate of 4.3 mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0127] Step S3: Mix 57g of aminated polyol with 47.9g of hexamethylene diisocyanate trimer and heat to 73°C. Add 0.40g of dibutyltin dilaurate and react for 1.4h under N2 protection at a flow rate of 4.3mL / min. Then cool to room temperature to obtain modified polyurethane.

[0128] Step S4: Mix 59g of ethyl methacrylate and 15.3g of hydroxyl acrylic resin at 320rpm until homogeneous, add 2.0g of triethanolamine, heat to 129℃, and react for 3.3h. Then add 1.06g of benzoyl peroxide, and under N2 protection at a flow rate of 4.3mL / min, heat to 74℃ and react for 3.7h. Then cool to room temperature to obtain modified acrylic resin.

[0129] Step S5: Mix 62g of modified polyurethane and 51g of modified acrylic resin, add 8.3g of rosin and stir at 230rpm, then add 1.8g of UV-0, 1.7g of antioxidant 1010 and 6.4g of styrene-acrylate, stir evenly at 230rpm and coat it on the surface of release paper with a thickness of 30μm. Curing is performed using an electron beam device with an irradiation dose of 40kGy, an irradiation rate of 10m / min and an accelerating voltage of 200kV to obtain EB curing coating for release paper of automotive interior leather.

[0130] Example 8

[0131] This embodiment provides a method for preparing EB-cured coatings for release paper used in automotive interior leather, such as... Figure 1 As shown, the preparation method specifically includes the following steps:

[0132] Step S1: 62g of poly(1,4-butanediol adipate) and 13.0g of acrylic acid were mixed evenly at 370rpm, heated to 137℃, and 2.3g of p-toluenesulfonic acid was added. Under N2 protection at a flow rate of 5.3mL / min, the mixture was allowed to react completely for 1.4h and then cooled to room temperature to obtain the grafted modified polyol.

[0133] In step S2, 67g of grafted modified polyol was heated to 134℃, and 5.8g of triethanolamine and 0.42g of triethylamine were added sequentially. The mixture was stirred at 260rpm and reacted completely for 2.1h under N2 protection at a flow rate of 5.3mL / min. The mixture was then cooled to room temperature to obtain the aminated polyol.

[0134] Step S3: Mix 63g of aminated polyol with 56.7g of diphenylmethane diisocyanate and heat to 70°C. Add 0.31g of dibutyltin dilaurate and react for 1.7h under N2 protection at a flow rate of 5.3mL / min. Then cool to room temperature to obtain aminated polyol.

[0135] In step S4, 64g of ethyl methacrylate and 14.7g of hydroxyl acrylic resin were mixed evenly at 370rpm, 2.6g of triethanolamine was added, and the mixture was heated to 124℃ and reacted completely for 3.6h. Then, 1.00g of azobisisobutyronitrile was added, and the mixture was heated to 77℃ under N2 protection at a flow rate of 5.3mL / min and reacted completely for 4.5h before being cooled to room temperature to obtain the modified acrylic resin.

[0136] In step S5, 64g of modified polyurethane and 47g of modified acrylic resin are mixed, 6.4g of rosin is added and stirred at 210rpm, then 2.2g of UV-0, 1.3g of antioxidant 1010 and 8.3g of phthalate are added and stirred evenly at 210rpm. The mixture is then coated onto the surface of release paper with a thickness of 38μm and cured using an electron beam device with an irradiation dose of 40kGy, an irradiation rate of 12m / min and an accelerating voltage of 250kV to obtain the EB curable coating for release paper used in automotive interior leather.

[0137] Comparative Example 1

[0138] This embodiment provides an EB-cured release paper coating for automotive interior leather. The difference from Example 1 is that the amount of acrylic acid added in step S1 is adjusted to 21g. Compared to Example 1, the amount of acrylic acid added in this embodiment is increased by 9g. This increased amount is deducted from the equal proportions of poly(1,4-butanediol adipate) and p-toluenesulfonic acid, ensuring that the proportions of other components besides acrylic acid remain unchanged. Other process parameters and operating conditions are exactly the same as in Example 1.

[0139] Comparative Example 2

[0140] This embodiment provides an EB-cured release paper coating for automotive interior leather. The difference from Example 1 is that the amount of acrylic acid added in step S1 is adjusted to 3g. Compared to Example 1, the amount of acrylic acid added in this embodiment is reduced by 9g. The reduced amount is proportionally added to poly(1,4-butanediol adipate) and p-toluenesulfonic acid, ensuring that the proportions of all components except acrylic acid remain unchanged. Other process parameters and operating conditions are exactly the same as in Example 1.

[0141] Comparative Example 3

[0142] This embodiment provides an EB-cured release paper coating for automotive interior leather. The difference from Embodiment 1 is that the amount of triethanolamine added in step S2 is adjusted to 9.2g. Compared to Embodiment 1, the amount of triethanolamine added in this embodiment is increased by 4g. This increased amount is deducted from the proportions of the grafted modified polyol and triethylamine, ensuring that the proportions of other components besides triethanolamine remain unchanged. Other process parameters and operating conditions are exactly the same as in Embodiment 1.

[0143] Comparative Example 4

[0144] This embodiment provides an EB-cured release paper coating for automotive interior leather. The difference from Embodiment 1 is that the amount of triethanolamine added in step S2 is adjusted to 1.2g. Compared to Embodiment 1, the amount of triethanolamine added in this embodiment is reduced by 4g. The reduced amount is proportionally added to the grafted modified polyol and triethylamine, ensuring that the proportions of the other components, except for triethanolamine, remain unchanged. Other process parameters and operating conditions are exactly the same as in Embodiment 1.

[0145] 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; the hydrolysis resistance of the coating was tested after being placed in an environment of 90°C and 90% RH for 72 hours according to GB / T 1733-1993, and the adhesion was ≤2 grade to be considered qualified; the resistance to denatured alcohol was tested by mixing 99% anhydrous ethanol and 1% methyl ethyl ketone and rubbing it with a cotton ball 10 times; sunlight simulation: irradiated for 240 hours according to DIN75220 standard, the adhesion was ≤2 grade after irradiation to be considered qualified. The test results are shown in Table 1.

[0146] Table 1. Test results of EB-cured release paper coating for automotive interior leather in Examples 1-8 and Comparative Examples 1-4.

[0147]

[0148] The test data from Example 1, Comparative Example 1, and Comparative Example 2 show that Comparative Example 1 has lower adhesion and sunlight simulation test performance than Example 1, but higher hardness. Comparative Example 2 has lower adhesion, hardness, hydrolysis resistance, resistance to denatured alcohol, and sunlight simulation test performance than Example 1. This is because the excessive acrylic acid in Comparative Example 1 results in an overly rigid coating surface, reducing adhesion. In Comparative Example 2, the lower acrylic acid content leads to incomplete cross-linking, reducing adhesion and hardness. Furthermore, the loose cross-linking structure increases the possibility of water molecule penetration, reducing hydrolysis resistance.

[0149] The test data from Examples 1, 3, and 4 show that Comparative Example 3 exhibits lower adhesion and sunlight simulation test performance compared to Example 1, but higher hardness. Comparative Example 4 shows lower adhesion, hardness, hydrolysis resistance, alcohol resistance, and sunlight simulation test performance compared to Example 1. This is because the excessive amination reagent in Comparative Example 3 increases the cross-linking degree, forming a denser network structure and increasing the coating hardness, leading to reduced adhesion. In Comparative Example 4, the lower content of the amination reagent results in insufficient cross-linking reaction, leading to a looser coating structure and reduced adhesion, hardness, and hydrolysis resistance.

[0150] The above description is only a specific embodiment 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 conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing an EB-cured release paper coating for automotive interior leather, characterized in that, The preparation method is as follows: Step S1: After the polyol and acrylic acid are mixed evenly, the mixture is heated to the first temperature, the first catalyst is added, and the mixture is allowed to react fully under the protection of an inert gas and then cooled to room temperature to obtain the grafted modified polyol. Step S2: The grafted modified polyol is heated to a second temperature, and the amination reagent and the second catalyst are added sequentially. Under the protection of an inert gas, the reaction is allowed to proceed until the temperature is lowered to room temperature to obtain the amination polyol. Step S3: After the aminated polyol and isocyanate are mixed evenly, the mixture is heated to a third temperature, a third catalyst is added, and the mixture is allowed to react fully under the protection of an inert gas and then cooled to room temperature to obtain the modified polyurethane. Step S4: After the acrylic monomer and hydroxy acrylic resin are mixed evenly, an amination agent is added, and the mixture is heated to a second temperature. After the reaction is complete, a fourth catalyst is added, and the mixture is heated to a third temperature under inert gas protection. After the reaction is complete, the mixture is cooled to room temperature to obtain the modified acrylic resin. Step S5: Mix the modified polyurethane and modified acrylic resin, add rosin and stir, then add ultraviolet absorber, antioxidant and plasticizer, stir evenly and coat it on the surface of release paper, and use electron beam equipment to cure it to obtain an EB curing coating for release paper of automotive interior leather. The polyol is poly(1,4-butanediol adipate), and the amount of feed is 50-70g. The amount of acrylic acid added is 10-30% of the amount of polyol added; The amination reagent is triethanolamine, and the amount added is 5-15% of the amount of grafted modified polyol. The amount of hydroxyl acrylic resin added is 10-30% of the amount of acrylic monomer added; The irradiation dose of the electron beam device is 20-50 kGy.

2. The method for preparing an EB-cured release paper coating for automotive interior leather according to claim 1, characterized in that, In step S1, The first temperature is 120-150℃; The first catalyst is p-toluenesulfonic acid, and the feed amount 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 1-2 hours.

3. The method for preparing an EB-cured release paper coating for automotive interior leather according to claim 1, characterized in that, In step S2, The amount of grafted modified polyol fed is 50-70g; The second temperature is 120-140℃; The second catalyst is triethylamine, and the feed amount is 0.1-1% of the feed amount of the grafted 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 2-3 hours.

4. The preparation method of the EB curable release paper coating for automotive interior leather according to claim 1, characterized in that, In step S3, The amount of the aminated polyol fed is 50-70g; The isocyanate is hexamethylene diisocyanate trimer or diphenylmethane diisocyanate; The amount of isocyanate fed is 80-90% of the amount of aminated polyol fed; The third temperature is 70-80℃; The third catalyst is dibutyltin dilaurate, and its feed amount is 0.1-1% of the feed amount of the aminated polyol; The inert gas is N2, and the gas flow rate is 4-6 mL / min; The reaction time at the third temperature is 1-2 hours.

5. The method for preparing an EB-cured release paper coating for automotive interior leather according to claim 1, characterized in that, In step S4, The acrylic monomer is ethyl methacrylate, and the feed amount is 50-70g; The amination reagent is triethanolamine, and the amount added is 3-5% of the amount of acrylic acid monomer added. The second temperature is 120-140℃; The reaction time at the second temperature is 2-4 hours.

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

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

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

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

10. An EB-cured release paper coating for automotive interior leather prepared by the method described in any one of claims 1 to 9.

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