A synthetic leather surface coating material and a construction process for reverse coating treatment thereof

Abstract

The present application belongs to the field of synthetic leather and its manufacturing, and more specifically, to a synthetic leather surface coating material and a construction process for reverse coating treatment thereof. A synthetic leather surface coating material comprises the following components in parts by weight: 70-90 parts of a polyurethane composition, 8-10 parts of modified bamboo charcoal fibers, 1-4 parts of a curing agent, 0.5-1.5 parts of a defoaming agent, and 3-7 parts of an auxiliary agent, wherein the auxiliary agent comprises sodium methacrylate, sodium hydroxymethylcellulose, and dodecafluoroheptyl methacrylate. A synthetic leather surface coating material of the present application and a construction process for reverse coating treatment thereof improve the problem that the existing material loading is prone to poor leveling of the processing material on the surface, making it impossible to apply it evenly, causing the coating quality of the surface to decline rapidly, and the chemical resistance and wear resistance, etc. cannot meet the coating performance requirements of the surface of the automotive interior skin, so that the obtained synthetic leather surface coating material has good leveling and mechanical properties and ensures that only one loading is required, and the mechanical properties and wear resistance and comfortable and smooth appearance meet the automotive interior requirements.

Description

Technical Field

[0001] The present application belongs to the field of synthetic leather and its manufacturing, and more specifically, to a synthetic leather surface coating material and a construction process for reverse coating treatment thereof. Background Art

[0002] Natural leather is widely used in the production of daily necessities and industrial products due to its excellent natural properties. However, with the growth of the world's population, human demand for leather has doubled, and the limited amount of natural leather has long been unable to meet this demand. In order to resolve this contradiction, scientists began to research and develop artificial leather and synthetic leather decades ago to make up for the shortcomings of natural leather. In practice, the excellent properties of synthetic leather cannot be replaced by natural leather. From the analysis of domestic and foreign markets, synthetic leather has also largely replaced the scarce natural leather.

[0003] In the process of synthetic leather processing, workers usually spray the treatment agent on the synthetic leather surface coating material manually, and use a coating roller to perform 2-3 layers of gravure rolling printing on the treatment agent on the synthetic leather surface coating material. However, this method of loading materials is prone to poor leveling of the treatment material on the surface, making it impossible to apply it evenly, causing the coating quality of the surface to decline rapidly, and the chemical resistance and wear resistance cannot meet the coating performance requirements of the automotive interior surface. In addition, the single-plate loading is small and the process is difficult to master, which seriously affects the processing efficiency and also causes a waste of human resources. Summary of the invention

[0004] In view of the problem that in the existing synthetic leather processing process, the leveling of the treated material on the surface is poor and the single-plate material is small, resulting in a decrease in the coating quality of the surface and seriously affecting the processing efficiency, the present application provides a synthetic leather surface coating material and a construction process for reverse coating treatment thereof.

[0005] In a first aspect, the present application provides a synthetic leather surface coating material, which adopts the following technical solution: A synthetic leather surface coating material comprises the following components in parts by weight: 70-90 parts of a polyurethane composition, 8-10 parts of modified bamboo charcoal fibers, 1-4 parts of a curing agent, 0.5-1.5 parts of a defoaming agent, and 3-7 parts of an auxiliary agent, wherein the auxiliary agent comprises sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate.

[0006] By adopting the above technical scheme, the main material of the epidermal coating is formed by the polyurethane composition and the modified bamboo charcoal fiber, so that the epidermal coating has better stability, chemical resistance, resilience and other mechanical properties; the modified bamboo charcoal fiber makes the coating material have smaller compression deformation, better wear resistance, and both environmental protection and comfort; combined with the mixing effect of the auxiliary agents sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate, the leveling performance of the overall coating material can be improved, and the problem of wrinkles after coating can be avoided, so that the coating surface is smooth; sodium methacrylate and sodium hydroxymethyl cellulose have considerable polarity and hydrophilicity, which can reduce the tension of the surface coating, which is conducive to the flow and uniform distribution of the wet coating, and sodium hydroxymethyl cellulose can make the coating surface soft and comfortable, and then dodecafluoroheptyl methacrylate is mixed. Since dodecafluoroheptyl methacrylate contains multiple fluorine atoms, the coating film powdering, cracking, gloss reduction and other phenomena are further reduced, so that the coating surface has good permeability and good stain resistance, and also improves the anti-adhesion and anti-damage properties, thereby improving the comfort and service life of the synthetic leather surface.

[0007] By organically mixing the above components, the coating material has comprehensive properties such as low surface energy, high mechanical properties, corrosion resistance, and chemical resistance.

[0008] The mass ratio of the sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate is (3-5):(1-3):1.

[0009] By adopting the above technical scheme, sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate are mixed within a certain mass ratio range, the wear resistance, corrosion resistance and softness of the coating material are improved while also having excellent leveling performance.

[0010] In a specific embodiment, the preparation method of the modified bamboo charcoal fiber includes: immersing the bamboo charcoal fiber in a NaOH aqueous solution for 5-8 hours, taking it out and drying it to obtain passivated bamboo charcoal fiber; adding dopamine and mica powder to Tris-hydrochloric acid buffer, adding them to the passivated bamboo charcoal fiber after ultrasonic dispersion, and stirring the reaction at 35-50°C to obtain modified bamboo charcoal fiber.

[0011] By adopting the above technical scheme, the bamboo charcoal fiber is immersed in an alkaline solution for surface passivation treatment, and then dopamine, mica powder, etc. are added to make the bamboo charcoal fiber grafted with dopamine. The mica powder is attached to the gaps and surface of the bamboo charcoal fiber to play a barrier role, and the corrosion resistance effect can also be improved, and the wear resistance is further improved. The stability of the material is improved, the tensile strength is increased, the impact resistance and deformation resistance are enhanced, and the material has anti-ultraviolet and infrared properties, etc., which work together to reduce the surface polarity of the bamboo charcoal fiber, and can better improve the compatibility and adhesion between the modified bamboo charcoal fiber and the polyurethane composition, thereby further improving the durability of the coating material.

[0012] In a specific implementation manner, the mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber is (0.3-0.6):(0.1-0.4):1.

[0013] By adopting the above technical scheme, dopamine, mica powder and passivated bamboo charcoal fiber are mixed within a certain mass ratio range, so that the modified bamboo charcoal fiber has considerable mechanical properties, surface compatibility and adhesion. If the dopamine content is too high, the mechanical properties and wear resistance of the coating material will be reduced. If the mica powder content is too low, the integrity of the material will be reduced, the elasticity, comfort and anti-wrinkle performance will be weakened, and the adhesion ability of the coating will be reduced.

[0014] In a specific embodiment, the polyurethane composition includes polycarbonate polyurethane and epoxy-modified polyurethane.

[0015] The mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is (2-5):1.

[0016] By adopting the above technical scheme, polycarbonate polyurethane and epoxy modified polyurethane are mixed in a certain proportion, so that the material is guaranteed to have excellent elasticity, wear resistance, chemical resistance and mechanical properties, and the epoxy modified polyurethane can also interact with the modified bamboo charcoal fiber to improve the adhesion, integrity and durability of the overall material.

[0017] In the second aspect, the present application provides a construction process for reverse coating treatment of synthetic leather surface coating materials, adopting the following technical scheme: a multi-roller reverse spraying equipment is used to spray the coating material on the synthetic leather surface, the multi-roller reverse spraying equipment includes a wall panel, a main drive rubber roller is arranged on the wall panel, a letterpress coating roller is installed parallel to the main drive rubber roller directly below the main drive rubber roller, the letterpress coating roller is installed on the wall panel, there is a surface coating film between the main drive rubber roller and the letterpress coating roller, and the letterpress coating roller and the surface coating film move in reverse directions; a scraper is installed on one side of the letterpress coating roller, and the scraper is connected to a storage box through a pipe.

[0018] By adopting the above technical scheme and using the reverse coating process, the relief coating roller and the surface are moved in the opposite direction, and the coating material is evenly coated on the surface, further avoiding the problem of poor leveling of the coating material on the surface. At the same time, the scraper is connected to the material storage box, and the organic coordination of the relief coating roller, the main drive rubber roller and the scraper is adjusted, so as to avoid the problem of less material being loaded at one time and the need for multiple loadings.

[0019] In a specific embodiment, the scraper and the relief coating roller form an angle of about 30°-45°, and the scraper and the relief coating roller move in opposite directions.

[0020] By adopting the above technical solution, the angle and travel direction of the scraper and the relief coating roller are adjusted so that a certain thickness of sludge appears in the gap, which can achieve uniform coating, quantitative coating and eliminate foam.

[0021] In a specific implementation manner, the speed ratio between the main drive rubber roller and the relief coating roller is (1.25-1.8):1.

[0022] By adopting the above technical solution, the speed ratio is precisely controlled to make the tension between the main drive rubber roller and the relief coating roller, so as to ensure the flatness of the synthetic leather during the spraying process, improve the uniformity of the coating, reduce the coating defects such as stripes and wrinkles caused by the expansion and contraction of the synthetic leather material, and better meet the coating needs of the synthetic leather.

[0023] In summary, this application has the following beneficial effects: 1. The main material of the epidermal coating is formed by a polyurethane composition and modified bamboo charcoal fibers, so that the epidermal coating has better stability, chemical resistance, resilience and other mechanical properties; the modified bamboo charcoal fibers make the coating material have smaller compression deformation, better wear resistance, and both environmental protection and comfort. Combined with the auxiliary agents sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate, the leveling performance of the overall coating material can be improved, and the problem of wrinkles after coating can be avoided, so that the coating surface is smooth. Sodium methacrylate and sodium hydroxymethyl cellulose have considerable polarity and hydrophilicity, which can reduce the tension of the surface coating and facilitate the flow and uniform distribution of the wet coating. Sodium hydroxymethyl cellulose can make the coating surface soft and comfortable. Dodecafluoroheptyl methacrylate is mixed. Since dodecafluoroheptyl methacrylate contains multiple fluorine atoms, the coating film powdering, cracking, gloss reduction and other phenomena are further reduced, so that the coating surface has good permeability and good stain resistance, and also improves the anti-adhesion and anti-damage properties, thereby improving the comfort and service life of the synthetic leather surface.

[0024] 2. By mixing dopamine, mica powder and passivated bamboo charcoal fiber within a certain mass ratio range, the modified bamboo charcoal fiber has considerable mechanical properties, surface compatibility and adhesion. If the dopamine content is too high, the mechanical properties and wear resistance of the coating material will be reduced. If the mica powder content is too low, the integrity of the material will be reduced, and the elasticity, comfort and anti-wrinkle properties will be weakened, and the adhesion ability of the coating will be reduced.

[0025] 3. By using the reverse coating process, the relief coating roller and the skin move in the opposite direction, and the coating material is evenly coated on the skin, further avoiding the problem of poor leveling of the coating material on the skin. At the same time, the scraper is connected to the material storage box, and the organic coordination of the relief coating roller, the main drive rubber roller and the scraper is adjusted, so as to avoid the problem of less material loading at one time and the need for multiple loading. DETAILED DESCRIPTION

[0026] The present application is further described in detail below with reference to the embodiments.

[0027] Some of the raw materials used in the preparation examples and embodiments: the curing agent is an isocyanate curing agent, purchased from Shanghai Kain Chemical Co., Ltd.; the defoaming agent is azodicarbonamide purchased from Jinan Yeqing Biotechnology Co., Ltd.; polycarbonate polyurethane; brand PPD95A; epoxy modified polyurethane purchased from Changsha Shuangzhou Anticorrosion Materials Co., Ltd.; bamboo charcoal fiber specification: 75D / 72f, purchased from Shaoxing Xineng Textile Technology Co., Ltd.; mica powder specification: particle size 40μm purchased from Lingshou County Huante Mineral Products Processing Plant; NaOH aqueous solution is a 10% NaOH aqueous solution prepared from sodium hydroxide and water; Tris-hydrochloric acid buffer pH pH7.0-9.0 was purchased from Isejiu (Jiangsu Lianyungang) Biotechnology Co., Ltd.

[0028] The raw materials used in the examples and comparative examples that are not otherwise specified are all conventional products that can be purchased from the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the multi-roller reverse spraying equipment provided in Example 1 of the present application.

[0030] Explanation of the reference numerals: 1. wall panel; 2. main drive rubber roller; 3. relief coating roller; 4. surface coating film; 5. scraper; 51. material storage box; 12. main drive motor; 222. main drive reducer; 13. coating motor, 33. coating reducer, 23. bearing.

[0031] Preparation Example Preparation Example 1 The bamboo charcoal fiber was immersed in a NaOH aqueous solution for 8 hours, taken out and dried to obtain the passivated bamboo charcoal fiber; dopamine and mica powder were added to 50 ml of Tris-hydrochloric acid buffer, and added to the passivated bamboo charcoal fiber after ultrasonic dispersion, and the mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber was controlled to be 0.3:0.1:1, and the reaction was stirred at 35°C for 24 hours. After washing with water, the modified bamboo charcoal fiber was dried in a vacuum at 60°C.

[0032] Preparation Example 2 Take bamboo charcoal fiber and immerse it in NaOH aqueous solution for 8 hours, take it out and dry it to obtain passivated bamboo charcoal fiber; add dopamine and mica powder into 50 ml of Tris-hydrochloric acid buffer, add it to the passivated bamboo charcoal fiber after ultrasonic dispersion, control the mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber to be 0.6:0.4:1, stir and react at 35°C for 24 hours, wash with water, and vacuum dry at 60°C to obtain modified bamboo charcoal fiber.

[0033] Preparation Example 3 Immerse the bamboo charcoal fiber in a NaOH aqueous solution for 8 hours, take it out and dry it to obtain passivated bamboo charcoal fiber; add dopamine and mica powder into 50 ml of Tris-hydrochloric acid buffer, add it to the passivated bamboo charcoal fiber after ultrasonic dispersion, control the mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber to be 1:0.4:1, stir and react at 35°C for 24 hours, wash with water, and dry it in vacuum at 60°C to obtain modified bamboo charcoal fiber.

[0034] Preparation Example 4 Take bamboo charcoal fiber and immerse it in NaOH aqueous solution for 8 hours, take it out and dry it to obtain passivated bamboo charcoal fiber; add dopamine and mica powder into 50 ml of Tris-hydrochloric acid buffer, add it to the passivated bamboo charcoal fiber after ultrasonic dispersion, control the mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber to be 0.6:0.8:1, stir and react at 35°C for 24 hours, wash with water, and dry it in vacuum at 60°C to obtain modified bamboo charcoal fiber.

[0035] Preparation Example 5 The bamboo charcoal fiber was immersed in a NaOH aqueous solution for 8 hours, taken out and dried to obtain the passivated bamboo charcoal fiber; dopamine was added to 50 ml of Tris-hydrochloric acid buffer, and added to the passivated bamboo charcoal fiber after ultrasonic dispersion, and the mass ratio of dopamine to passivated bamboo charcoal fiber was controlled to be 0.6:1, and the reaction was stirred at 35-50°C for 24 hours. After washing with water, the modified bamboo charcoal fiber was dried at 60°C in a vacuum to obtain the modified bamboo charcoal fiber. Example

[0036] like Figure 1As shown, a multi-roller reverse spraying device is used to spray the coating material on the surface of the synthetic leather. The multi-roller reverse spraying device includes a wall panel 1, a main drive motor 12 is arranged on the wall panel 1, a main drive reducer 222 is arranged on the main drive motor 12, the output shaft of the main drive motor 12 is connected to a main drive rubber roller 2, and a bearing 23 is arranged on the main drive rubber roller 2; a relief coating roller 3 is installed parallel to the main drive rubber roller 2, and a bearing 23 is arranged on the relief coating roller 3, and the bearing is connected to the coating motor 13, and the coating motor 1 3 is provided with a coating reducer 33, the relief coating roller 3 is installed on the wall panel 1, there is a skin coating film 4 between the main driving rubber roller 2 and the relief coating roller 3, and the relief coating roller 3 and the skin coating film 4 move in opposite directions; the scraper 5 forms an angle of about 30° with the relief coating roller 3, and the moving directions of the scraper 5 and the relief coating roller 3 are opposite, a scraper 5 is installed on one side of the relief coating roller 3, the scraper 5 is connected to a storage box 51 through a pipeline, and the speed ratio between the main driving rubber roller 2 and the relief coating roller 3 is 1.25:1.

[0037] Example 1 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0038] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0039] Example 2 A synthetic leather surface coating material comprises the following components in parts by weight: 900 g of a polyurethane composition, 80 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 4 g of a curing agent, 5 g of a defoaming agent, and 70 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0040] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0041] Example 3 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 5:1:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0042] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0043] Example 4 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 2:4:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0044] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0045] Example 5 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 5:1.

[0046] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0047] Example 6 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; and the polyurethane composition is polycarbonate polyurethane.

[0048] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0049] Example 7 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; and the polyurethane composition is epoxy-modified polyurethane.

[0050] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0051] Example 8 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 2, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0052] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0053] Example 9 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 3, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0054] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0055] Example 10 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 4, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0056] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0057] Embodiment 11 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 5, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0058] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0059] Comparative Example Comparative Example 1 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate; the polyurethane composition is polycarbonate polyurethane and epoxy modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is 2:1.

[0060] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0061] Comparative Example 2 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium hydroxymethyl cellulose; the polyurethane composition is polycarbonate polyurethane and epoxy modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is 2:1.

[0062] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0063] Comparative Example 3 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is dodecafluoroheptyl methacrylate; the polyurethane composition comprises polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0064] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0065] Comparative Example 4 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate and sodium hydroxymethyl cellulose in a mass ratio of 4:3; the polyurethane composition is polycarbonate polyurethane and epoxy modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is 2:1.

[0066] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0067] Comparative Example 5 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate and dodecafluoroheptyl methacrylate in a mass ratio of 6:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0068] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0069] Comparative Example 6 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of modified bamboo charcoal fiber obtained in Preparation Example 1, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate in a mass ratio of 6:1; the polyurethane composition is polycarbonate polyurethane and epoxy modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is 2:1.

[0070] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, modified bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed, and reacted by using an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by washing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, and the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0071] Comparative Example 7 A synthetic leather surface coating material comprises the following components in parts by weight: 700 g of a polyurethane composition, 100 g of bamboo charcoal fiber, 10 g of a curing agent, 1.5 g of a defoaming agent, and 30 g of an auxiliary agent, wherein the auxiliary agent is sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate in a mass ratio of 3:3:1; the polyurethane composition is polycarbonate polyurethane and epoxy-modified polyurethane, and the mass ratio of the polycarbonate polyurethane to the epoxy-modified polyurethane is 2:1.

[0072] The construction process of reverse coating treatment of synthetic leather surface coating material is as follows: a polyurethane composition, bamboo charcoal fiber, a curing agent, a defoaming agent and an auxiliary agent are mixed and reacted by an extruder, wherein the reaction temperature is 120°C; the surface coating material is obtained by rinsing with acetone, filtering and drying at 40°C, and a multi-roller reverse spraying device is used to spray the coating material on the synthetic leather surface, the treated mixture is poured into a storage box 51, and the multi-roller reverse spraying device is started to coat the synthetic leather surface.

[0073] Comparative Example 8 The difference between this comparative example and Example 1 is that in the multi-roller reverse spraying equipment, the relief coating roller 3 and the epidermal coating film 4 move in the forward direction; the scraper 5 forms an angle of about 30° with the relief coating roller 3, and the scraper 5 and the relief coating roller 3 have the same moving direction, a scraper 5 is installed on one side of the relief coating roller 3, and the scraper 5 is connected to a storage box 51 through a pipeline, and the speed ratio between the main drive rubber roller 2 and the relief coating roller 3 is 1.25:1.

[0074] Performance Testing The performance test of the synthetic leather surface coating material obtained in the embodiment and the comparative example adopts the following method: a. Appearance performance test: The surface leveling and wrinkle resistance of the prepared synthetic leather surface coating material are tested by the appearance glossiness and hand comfort. The incident light projection angle of the gloss meter is set to 60 degrees. Three points are selected on the coating sample for testing. The error does not exceed 5%. The average value is the glossiness of the coating. The glossiness is less than 10% and is qualified. b. Elongation at break test: refer to GB / T528-2009, sample specification: type 1, test speed: 500mm / min; c. RCA. Paper tape wear test: The sample is placed in the wear tester. According to the evaluation criteria of wear degree and playback quality, the results are divided into 5 levels. The smaller the level, the better the wear resistance. The test results are shown in Table 1 below: Table 1 Performance test results As can be seen from Table 1, the synthetic leather surface coating material obtained in the above embodiment has good leveling and mechanical properties and can ensure only one-time loading. The mechanical properties, wear resistance, and comfortable appearance meet the requirements of automobile interior decoration.

[0075] Compared with Comparative Examples 1-6 and Example 1, it can be seen that after reverse coating, the appearance, comfort and wear resistance of the synthetic leather surface coating material prepared in Example 1 are better than those of Comparative Examples 1-2. It is analyzed that the surface coating main material is formed by the polyurethane composition and the modified bamboo charcoal fiber, so that the surface coating has better stability, chemical resistance, resilience and other mechanical properties; the mixing effect of the auxiliary agents sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate can improve the leveling performance of the overall coating material, avoid the problem of wrinkles after coating, and make The coating surface is smooth. Sodium methacrylate and sodium hydroxymethyl cellulose have considerable polarity and hydrophilicity, which can reduce the tension of the surface coating and are beneficial to the flow and uniform distribution of the wet coating. Sodium hydroxymethyl cellulose can make the coating surface soft and comfortable. Dodecafluoroheptyl methacrylate is mixed. Since dodecafluoroheptyl methacrylate contains multiple fluorine atoms, the coating film powdering, cracking, gloss reduction and other phenomena are further reduced, so that the coating surface has good permeability and good stain resistance, and also improves the anti-adhesion and anti-damage properties, thereby improving the comfort and service life of the synthetic leather surface.

[0076] By comparing Example 1 with Examples 9-11 and Comparative Example 7, it can be seen that after reverse coating, the appearance, comfort and wear resistance of the synthetic leather surface coating material prepared in Example 1 are better than those of Examples 9-11 and Comparative Example 7. Analysis shows that by invading the bamboo charcoal fiber in an alkaline solution for surface passivation treatment, and then mixing dopamine, mica powder and passivated bamboo charcoal fiber in a certain mass ratio range, the modified bamboo charcoal fiber has considerable mechanical properties, surface compatibility and adhesion. If the dopamine content is too high, the mechanical properties and wear resistance of the coating material will be reduced. If the mica powder content is too low, the integrity of the material will be reduced, the elasticity, comfort and wrinkle resistance will be weakened, and the adhesion ability of the coating will be reduced.

[0077] By comparing Example 1 and Comparative Example 8, it can be seen that after the synthetic leather surface coating material prepared in Example 1 is reversely coated, the appearance, comfort and wear resistance are better than those of Comparative Example 8. It is analyzed that by using the reverse coating process, the relief coating roller and the surface of the skin are moved in the opposite direction, and the coating material is evenly coated on the surface of the skin, which further avoids the problem of poor leveling of the coating material on the surface of the skin. At the same time, the scraper is connected to the storage box, and the organic coordination of the relief coating roller, the main drive rubber roller and the scraper is adjusted to avoid the problem of less material being loaded at one time and the need for multiple loadings. The angle and travel direction of the scraper and the relief coating roller are adjusted so that a certain thickness of sludge appears in the gap, so as to achieve uniform coating, quantitative coating and the purpose of eliminating foam.

[0078] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A synthetic leather surface coating material, characterized in that: The invention comprises the following components in parts by weight: 70-90 parts of a polyurethane composition, 8-10 parts of modified bamboo charcoal fibers, 1-4 parts of a curing agent, 0.5-1.5 parts of a defoaming agent, and 3-7 parts of an auxiliary agent, wherein the auxiliary agent comprises sodium methacrylate, sodium hydroxymethyl cellulose, and dodecafluoroheptyl methacrylate.

2. The synthetic leather surface coating material according to claim 1, characterized in that: The mass ratio of the sodium methacrylate, sodium hydroxymethyl cellulose and dodecafluoroheptyl methacrylate is (3-5): (1-3):

1.

3. The synthetic leather surface coating material according to claim 1, characterized in that: The preparation method of the modified bamboo charcoal fiber comprises the following steps: immersing the bamboo charcoal fiber in a NaOH aqueous solution for 5-8 hours, taking it out and drying it to obtain the passivated bamboo charcoal fiber; adding dopamine and mica powder into a Tris-hydrochloric acid buffer, ultrasonically dispersing them, adding them into the passivated bamboo charcoal fiber, and reacting them by stirring at 35-50° C. to obtain the modified bamboo charcoal fiber.

4. The synthetic leather surface coating material according to claim 3, characterized in that: The mass ratio of dopamine, mica powder and passivated bamboo charcoal fiber is (0.3-0.6):(0.1-0.4):

1.

5. The synthetic leather surface coating material according to claim 1, characterized in that: The polyurethane composition comprises polycarbonate polyurethane and epoxy modified polyurethane.

6. The synthetic leather surface coating material according to claim 5, characterized in that: The mass ratio of the polycarbonate polyurethane to the epoxy modified polyurethane is (2-5):

1.

7. The construction process of reverse coating treatment of synthetic leather surface coating material according to claims 1-6, characterized in that: A multi-roller reverse spraying device is used to spray a coating material on the surface of synthetic leather. The multi-roller reverse spraying device comprises a wall panel (1). A main transmission rubber roller (2) is arranged on the wall panel (1). A relief coating roller (3) is installed in parallel directly below the main transmission rubber roller (2). The relief coating roller (3) is installed on the wall panel (1). A surface coating film (4) is arranged between the main transmission rubber roller (2) and the relief coating roller (3). The relief coating roller (3) and the surface coating film (4) move in opposite directions. A scraper (5) is installed on one side of the relief coating roller (3). The scraper (5) is connected to a material storage box (51) through a pipeline.

8. The construction process of reverse coating treatment of synthetic leather surface coating material according to claim 7, characterized in that: The scraper (5) and the relief coating roller (3) form an angle of about 30°-45°, and the scraper (5) and the relief coating roller (3) move in opposite directions.

9. The construction process of reverse coating treatment of synthetic leather surface coating material according to claim 7, characterized in that: The speed ratio between the main drive rubber roller (2) and the relief coating roller (3) is (1.25-1.8):1.

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