Preparation method of high-insulation polyurethane synthetic leather

Abstract

This invention discloses a method for preparing high-insulation polyurethane synthetic leather. The method includes: immersing nonwoven fabric in an insulating impregnation slurry containing graphene aerogel, hollow ceramic microspheres, and vacuum glass microspheres; after extrusion, coating the surface with a wet-process insulating coating slurry containing the same ternary composite system; and obtaining an insulating wet-process base layer after coagulation, washing, and drying. Then, an adhesive layer slurry, a middle layer insulating slurry containing insulating pigments, and a top layer abrasion-resistant slurry are sequentially coated onto release paper. After drying, these are laminated with the wet-process base layer, hot-pressed for shaping, and cooled for peeling to obtain the final product. This invention, through the dual insulating structure design of base fabric impregnation + wet-process insulating coating and the synergistic effect of the ternary composite system of graphene aerogel + hollow ceramic microspheres + vacuum glass microspheres, produces synthetic leather with a thermal conductivity ≤0.025W / (m·K), a tensile strength ≥400N / 3cm, and a tear strength ≥40N / 3cm. It possesses excellent thermal insulation, mechanical properties, and abrasion resistance, making it suitable for automotive interiors, outdoor equipment, and other fields.

Description

Technical Field

[0001] This invention relates to the field of synthetic leather technology, specifically to a method for preparing high-thermal-insulation polyurethane synthetic leather, applicable to fields such as automotive interiors, outdoor equipment, footwear, and home furnishings where high thermal comfort is required. Background Technology

[0002] Polyurethane synthetic leather is widely used in automotive interiors, outdoor equipment, footwear, apparel, and home furnishings due to its excellent physical properties and feel. However, traditional polyurethane synthetic leather has a high thermal conductivity, easily accumulating heat under direct sunlight, severely impacting the user experience. To improve its thermal insulation, existing technologies mainly employ two methods: one is to add low thermal conductivity fillers such as aerogels to wet or dry resins; the other is to use thermally insulating fillers with infrared reflective properties in the surface layer. However, these existing technologies have the following drawbacks: First: The problem of filler dispersion: fillers such as aerogel are prone to agglomeration, which leads to a decrease in mechanical properties; Second: The insulation structure is simple: the insulation filler is concentrated in the surface layer, and the insulation structure of the base fabric and the intermediate layer is not systematically designed, so the improvement in insulation is limited. Third: Synthetic leather cannot simultaneously achieve the comprehensive properties of high heat insulation, high strength, and high wear resistance.

[0003] Therefore, how to achieve ultra-low thermal conductivity while maintaining mechanical and abrasion resistance through the synergistic design of wet and dry processes remains a technical problem that synthetic leather products urgently need to solve. Summary of the Invention

[0004] To address the problem that existing synthetic leathers cannot simultaneously achieve both thermal insulation and mechanical properties, this invention provides a method for preparing high-thermal-insulation polyurethane synthetic leather, resulting in synthetic leather that possesses comprehensive properties of high thermal insulation, high strength, and high wear resistance.

[0005] To achieve the above objectives, the present invention provides a method for preparing high-heat-insulating polyurethane synthetic leather, comprising the following steps: S1. Impregnate the nonwoven fabric with the heat-insulating impregnation slurry to obtain the impregnated base fabric; the preparation process of the heat-insulating impregnation slurry is as follows: mix 100 parts of wet polyurethane resin, 200-300 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, and 3-5 parts of color paste, stir at 1500-2000 rpm for 15-20 min, let stand for degassing for 20-30 min, and obtain a heat-insulating impregnation slurry with a viscosity of 100-300 cps; S2. After extrusion, the impregnated base fabric is coated with a wet thermal insulation coating slurry. The preparation process of the wet thermal insulation coating slurry is as follows: 100 parts of wet polyurethane resin, 40-50 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, 1-2 parts of water-repellent agent, 0.5-0.8 parts of pore regulator, 0.5-0.8 parts of penetrant, and 1-3 parts of color paste are mixed and stirred at 1500-2000 rpm for 20-40 min, and then vacuum degassed for 60-70 min to obtain a wet thermal insulation coating slurry with a viscosity of 11000-14000 cps. S3. The base fabric after impregnation and coating is coagulated, washed, and dried to obtain a heat-insulating wet-process base. S4. Coat the release paper with adhesive layer slurry, middle layer heat insulation slurry and top layer abrasion slurry in sequence, and after drying, combine with the heat insulation wet process base to form a composite; S5. After drying, hot pressing and shaping, cooling, and peeling off the release paper, high heat insulation polyurethane synthetic leather is obtained.

[0006] Furthermore, the graphene aerogel has a three-dimensional porous network structure with a thermal conductivity ≤0.02 W / (m·K) and a specific surface area ≥800m² / g.

[0007] Furthermore, the hollow ceramic microspheres are alumina or zirconia-based hollow microspheres with a particle size of 10-80 μm and a wall thickness of 1-5 μm.

[0008] Furthermore, the vacuum glass microspheres are glass microspheres that are internally vacuum sealed, with a particle size of 20-100μm.

[0009] Furthermore, in step S2, the impregnated base fabric is squeezed by an extrusion roller to remove 80±5% of the slurry, and the doctor blade coating amount is 1.4±0.1kg / y.

[0010] Furthermore, in step S3, the coagulation and washing process uses a 15-30% DMF aqueous solution at a temperature of 25-35℃ for 10-15 minutes; the washing water temperature is 50-60℃ until the DMF residue is ≤0.1%.

[0011] Furthermore, in step S4, the adhesive layer slurry comprises, by weight: 100 parts of adhesive polyurethane resin, 10-30 parts of DMF, and 10-20 parts of MEK, with a viscosity of 8000-10000 cps at 25°C.

[0012] Furthermore, in step S4, the intermediate layer insulation slurry comprises, by weight: 100 parts of dry polyurethane resin, 30-80 parts of DMF, 10-40 parts of MEK, and 8-15 parts of insulation pigment, with a viscosity of 1800-2500 cps at 25°C.

[0013] Furthermore, in step S4, the surface wear-resistant slurry comprises, by weight: 100 parts of dry polyurethane resin, 30-80 parts of DMF, 10-40 parts of MEK, 8-15 parts of heat-insulating pigment, 2-4 parts of wear-resistant additive, and 0.2-0.5 parts of antioxidant, with a viscosity of 1800-2500 cps at 25°C.

[0014] Furthermore, the initial nonwoven fabric has a thickness of 0.65-0.75 mm, the impregnated base fabric has a thickness of 0.71-0.81 mm, the wet-process thermal insulation coating slurry has a coating thickness of 1.8-2.2 mm, the adhesive layer slurry has a coating thickness of 0.18-0.22 mm, the intermediate thermal insulation slurry has a coating thickness of 0.15-0.18 mm, and the surface abrasion-resistant slurry has a coating thickness of 0.12-0.15 mm.

[0015] This invention provides a method for preparing high-insulation polyurethane synthetic leather: through the dual structural design of wet impregnation + wet heat-insulating coating and the synergistic effect of a ternary composite system of graphene aerogel, hollow ceramic microspheres and vacuum glass microspheres, a high-insulation polyurethane synthetic leather with thermal conductivity ≤0.025 W / (m·K), tensile strength ≥400N / 3cm and tear strength ≥40N / 3cm was successfully prepared, achieving significant effects in terms of heat insulation performance, mechanical properties and wear resistance. Detailed Implementation

[0016] The technical solution of the present invention will be clearly and completely described below. The described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention provides a method for preparing high-insulation polyurethane synthetic leather, comprising the following steps: S1. Impregnate the nonwoven fabric with the heat-insulating impregnation slurry to obtain the impregnated base fabric; the preparation process of the heat-insulating impregnation slurry is as follows: mix 100 parts of wet polyurethane resin, 200-300 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, and 3-5 parts of color paste, stir at 1500-2000 rpm for 15-20 min, let stand for degassing for 20-30 min, and obtain a heat-insulating impregnation slurry with a viscosity of 100-300 cps; S2. After extrusion, the impregnated base fabric is coated with a wet thermal insulation coating slurry. The preparation process of the wet thermal insulation coating slurry is as follows: 100 parts of wet polyurethane resin, 40-50 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, 1-2 parts of water-repellent agent, 0.5-0.8 parts of pore regulator, 0.5-0.8 parts of penetrant, and 1-3 parts of color paste are mixed and stirred at 1500-2000 rpm for 20-40 min, and then vacuum degassed for 60-70 min to obtain a wet thermal insulation coating slurry with a viscosity of 11000-14000 cps. S3. The base fabric after impregnation and coating is coagulated, washed, and dried to obtain a heat-insulating wet-process base. S4. Coat the release paper with adhesive layer slurry, middle layer heat insulation slurry and top layer abrasion slurry in sequence, and after drying, combine with the heat insulation wet process base to form a composite; S5. After drying, hot pressing and shaping, cooling, and peeling off the release paper, high heat insulation polyurethane synthetic leather is obtained.

[0018] This invention discloses a method for preparing high-insulation polyurethane synthetic leather, constructing a triple insulation structure of "base fabric impregnation insulation + wet coating reinforcement + dry surface functionalization". By introducing a composite insulation system of graphene aerogel, hollow ceramic microspheres, and vacuum glass microspheres into both the impregnation slurry and the wet coating slurry, both the base fabric and the intermediate layer possess excellent insulation capabilities, laying the foundation for the high insulation performance of the final synthesized product; the subsequent dry surface layer composite further enhances the surface functionality and overall performance.

[0019] In this invention, the graphene aerogel has a three-dimensional porous network structure with a thermal conductivity ≤0.02 W / (m·K) and a specific surface area ≥800 m² / g. The three-dimensional porous network structure of the graphene aerogel can form extremely long heat conduction paths within the polymer matrix, effectively blocking heat transfer, and is one of the core materials for achieving ultra-low thermal conductivity in synthetic leather in this invention. The high specific surface area facilitates bonding with resin and reduces interfacial thermal resistance.

[0020] In this invention, the hollow ceramic microspheres are alumina or zirconia-based hollow microspheres with a particle size of 10-80 μm and a wall thickness of 1-5 μm. The alumina or zirconia-based microspheres themselves have high hardness and low thermal conductivity, and the hollow structure further reduces the density and thermal conductivity.

[0021] In this invention, the vacuum glass microspheres are glass microspheres that are internally vacuum-sealed, with a particle size of 20-100 μm. The internal vacuum state is an excellent heat insulator, which can block heat conduction and convection to the greatest extent. Its tiny spherical size can fill the gaps formed by other materials, making the heat insulation structure more compact and further improving the heat insulation effect.

[0022] In this invention, the water-repellent agent is PA0121 to improve hydrolysis resistance. The cell regulator is S-8I to adjust the cell structure and slow down the surface solidification rate. The penetrant is S-11 to improve the penetration rate of the coating resin and enhance peel performance.

[0023] In step S2, the impregnated base fabric is pressed by an extrusion roller to remove 80±5% of the slurry, and the doctor blade coating amount is 1.4±0.1 kg / y. Precise control of the extrusion amount after impregnation ensures that the base fabric fibers are fully filled with the insulating slurry, while preventing excessive slurry from causing difficulties or wasting costs in subsequent processes. A precise coating amount ensures the uniformity and stability of the wet coating thickness, which is crucial for guaranteeing consistent product quality.

[0024] In step S3, the coagulation and washing process uses a 15-30% DMF aqueous solution at a temperature of 25-35℃ for 10-15 minutes; the washing water temperature is 50-60℃ until the DMF residue is ≤0.1%. The coagulation process forms a uniform and fine microporous structure, which helps reduce heat conduction and maintain good mechanical properties and breathability. Strict control of the DMF residue ensures the environmental friendliness and safety of the synthetic leather.

[0025] In step S4, the adhesive layer slurry comprises, by weight, 100 parts of adhesive polyurethane resin, 10-30 parts of DMF, and 10-20 parts of MEK, with a viscosity of 8000-10000 cps at 25°C. MEK can adjust the drying speed and improve the peelability with the release paper; the viscosity of 8000-10000 cps helps to form a thicker wet film during coating, enhancing the leveling and bonding effect on the wet-laid base and improving interlayer adhesion.

[0026] In step S4, the intermediate layer insulation slurry comprises, by weight, 100 parts dry-process polyurethane resin, 30-80 parts DMF, 10-40 parts MEK, and 8-15 parts insulation pigment, with a viscosity of 1800-2500 cps at 25°C. The insulation pigment, while maintaining color, provides auxiliary insulation by reflecting or blocking infrared heat radiation. The DMF / MEK mixed solvent system allows for controlled drying rates, resulting in uniform pores or a dense structure and avoiding defects such as pinholes.

[0027] In step S4, the surface layer abrasion-resistant slurry comprises, by weight, 100 parts dry-process polyurethane resin, 30-80 parts DMF, 10-40 parts MEK, 8-15 parts heat-insulating pigment, 2-4 parts abrasion-resistant additive (BYK-370), and 0.2-0.5 parts antioxidant (pentaerythritol ester), with a viscosity of 1800-2500 cps at 25°C. This layer possesses triple functions of abrasion resistance, heat insulation, and aging resistance: the heat-insulating pigment ensures basic heat insulation of the surface; the abrasion-resistant additive enhances the surface's scratch resistance; and the antioxidant delays aging and yellowing. With a viscosity range of 1800-2500 cps, it is suitable for thin and uniform coating.

[0028] Preferably, the heat-insulating pigment is a high-temperature pigment produced by Guangdong Kaidelu New Material Technology Co., Ltd., and its models include, but are not limited to, CDL-BK805 (copper chrome black), CDL-Y905 (titanium yellow), CDL-Y501 (zinc iron yellow), CDL-A5311 (titanium nickel yellow), CDL-G726 (cobalt green), CDL-B5302 (cobalt blue), etc.

[0029] In this invention, the initial thickness of the nonwoven fabric is 0.65-0.75 mm, and the thickness of the impregnated base fabric is 0.71-0.81 mm. The wet-process thermal insulation coating slurry has a coating thickness of 1.8-2.2 mm, preferably 2 mm, and its thickness after drying is approximately 0.45 mm. The adhesive layer slurry has a coating thickness of 0.18-0.22 mm, preferably 0.2 mm, and its thickness after drying is approximately 0.07 mm. The intermediate thermal insulation slurry has a coating thickness of 0.15-0.18 mm, preferably 0.17 mm, and its thickness after drying is approximately 0.04 mm. The coating thickness of the surface wear-resistant slurry is 0.12-0.15mm, preferably 0.13mm. After drying, its thickness is about 0.03mm. The surface layer thickness is reduced to 0.12-0.15mm, which helps to maintain a soft feel while ensuring the surface wear resistance. The middle layer thickness of 0.15-0.18mm is sufficient to accommodate the heat-insulating pigment and form a heat-insulating barrier.

[0030] The beneficial technical effects of the synthetic leather obtained by the preparation method of the present invention are illustrated below through several examples and comparative examples. In the following examples and comparative examples, the graphene aerogel used has a thermal conductivity of 0.018 W / (m·K) and a specific surface area of ​​850 m² / g; the alumina hollow microspheres have a particle size of 50 μm; the vacuum glass microspheres have a particle size of 60 μm; and PA0121 water-repellent agent, S-8I pore regulator, and S-11 penetrant are used. The initial nonwoven fabric thickness is 0.7 mm, and the impregnated base fabric thickness is 0.73 mm. The wet-process heat insulation coating slurry has a coating thickness of 2 mm, and its thickness after drying is approximately 0.45 mm. The adhesive layer slurry has a coating thickness of 0.2 mm, and its thickness after drying is approximately 0.07 mm. The intermediate heat insulation slurry has a coating thickness of 0.17 mm, and its thickness after drying is approximately 0.04 mm. The coating thickness of the surface wear-resistant slurry is 0.13 mm, and its thickness after drying is approximately 0.03 mm. Example 1

[0031] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 3 parts of graphene aerogel, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0032] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 3 parts of graphene aerogel, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and vacuum degas for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0033] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0034] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0035] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather. Example 2

[0036] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 2 parts of graphene aerogel, 9 parts of alumina hollow microspheres, 2 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0037] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 2 parts of graphene aerogel, 9 parts of alumina hollow microspheres, 2 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0038] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0039] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0040] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather. Example 3

[0041] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 2 parts of graphene aerogel, 5 parts of alumina hollow microspheres, 6 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0042] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 2 parts of graphene aerogel, 5 parts of alumina hollow microspheres, 6 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0043] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0044] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0045] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather. Example 4

[0046] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 1 part of graphene aerogel, 4 parts of alumina hollow microspheres, 2 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0047] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 1 part of graphene aerogel, 4 parts of alumina hollow microspheres, 2 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0048] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0049] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0050] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather. Example 5

[0051] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 5 parts of graphene aerogel, 4 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0052] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 5 parts of graphene aerogel, 4 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0053] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0054] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0055] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather. Example 6

[0056] S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 4 parts of graphene aerogel, 9 parts of alumina hollow microspheres, 5 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0057] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 4 parts of graphene aerogel, 9 parts of alumina hollow microspheres, 5 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0058] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0059] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0060] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0061] Comparative Example 1 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF and 4 parts of color paste, stir at 1800 rpm for 18 min, let stand to degas for 25 min, and obtain a slurry with a viscosity of 200 cps.

[0062] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0063] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0064] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30°C for 12 minutes, then wash in warm water at 55°C until the DMF residue is ≤0.1%, and dry to obtain wet base fabric.

[0065] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0066] Comparative Example 2 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 3 parts of graphene aerogel, and 4 parts of color paste, stir at 1800 rpm for 18 min, let stand to degas for 25 min, and obtain a slurry with a viscosity of 200 cps.

[0067] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 3 parts of graphene aerogel, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0068] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0069] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0070] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0071] Comparative Example 3 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 13 parts of alumina hollow microspheres and 4 parts of color paste, stir at 1800 rpm for 18 min, let stand to degas for 25 min, and obtain a slurry with a viscosity of 200 cps.

[0072] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 13 parts of alumina hollow microspheres, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0073] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0074] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0075] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0076] Comparative Example 4 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 13 parts of vacuum glass microspheres and 4 parts of color paste, stir at 1800 rpm for 18 min, let stand to degas for 25 min, and obtain a slurry with a viscosity of 200 cps.

[0077] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 13 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and vacuum degas for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0078] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0079] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0080] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0081] Comparative Example 5 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 5 parts of graphene aerogel, 8 parts of alumina hollow microspheres, and 4 parts of color paste, stir at 1800 rpm for 18 min, and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0082] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 5 parts of graphene aerogel, 8 parts of alumina hollow microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0083] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0084] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0085] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0086] Comparative Example 6 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 5 parts of graphene aerogel, 8 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0087] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 5 parts of graphene aerogel, 8 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and vacuum degas for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0088] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0089] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0090] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0091] Comparative Example 7 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 8 parts of alumina hollow microspheres, 5 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0092] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 8 parts of alumina hollow microspheres, 5 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of cell regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and vacuum degas for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0093] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0094] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0095] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0096] Comparative Example 8 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 3 parts of graphene aerogel, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0097] S2. Base fabric impregnation: The nonwoven fabric is immersed in the impregnation slurry and then squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry).

[0098] S3. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0099] S4. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0100] Comparative Example 9 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 3 parts of silica aerogel powder, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0101] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 3 parts of silica aerogel powder, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and degas under vacuum for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0102] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0103] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0104] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 12 parts insulation pigment, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 10 parts insulation pigment, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0105] Comparative Example 10 S1. Preparation of heat-insulating impregnation slurry: Mix 100 parts of wet polyurethane resin, 250 parts of DMF, 3 parts of graphene aerogel, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, and 4 parts of color paste. Stir at 1800 rpm for 18 min and let stand to degas for 25 min to obtain a slurry with a viscosity of 200 cps.

[0106] S2. Preparation of wet coating slurry: Mix 100 parts of wet polyurethane resin, 45 parts of DMF, 3 parts of graphene aerogel, 6 parts of alumina hollow microspheres, 4 parts of vacuum glass microspheres, 1.5 parts of water-repellent agent, 0.6 parts of pore regulator, 0.6 parts of penetrant, and 2 parts of color paste. Stir at 1800 rpm for 30 min and vacuum degas for 65 min to obtain a slurry with a viscosity of 12500 cps.

[0107] S3. Impregnation and coating of base fabric: The nonwoven fabric is impregnated with impregnation slurry, squeezed by a 6.5KG extrusion roller (removing about 80% of the slurry), and then wet coating slurry is applied using a doctor blade, with a coating amount of 1.4kg / y.

[0108] S4. Coagulation and washing: Immerse the base fabric in a 22% DMF aqueous solution, coagulate at 30℃ for 12 minutes, then wash in warm water at 55℃ until the DMF residue is ≤0.1%, and dry to obtain the heat-insulating wet-process base fabric.

[0109] S5. Composite Functional Surface Layer: Adhesive Layer Slurry (9000cps): 100 parts adhesive polyurethane resin, 20 parts DMF, 15 parts MEK, coating thickness 0.15mm. Middle Layer Insulation Slurry (viscosity 2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, coating thickness 0.15mm. Surface Layer Abrasion-Resistant Slurry (2200cps): 100 parts dry polyurethane resin, 50 parts DMF, 25 parts MEK, 3 parts abrasion-resistant additive, 0.3 parts antioxidant, coating thickness 0.12mm. The above three slurries are sequentially coated onto the release paper, dried, and then laminated with the wet-process insulation base. The laminate is dried at 100℃ for 10 minutes, hot-pressed at 3.5MPa for setting, cooled, and the release paper is peeled off to obtain the finished synthetic leather.

[0110] Table 1. Performance test data of synthetic leather obtained from various embodiments and comparative examples. ; Note: Abrasion resistance rating - Excellent: No obvious damage; Good: Slight wear; Medium: Obvious wear.

[0111] in conclusion: 1. Example 1 (composite of the three materials) has a thermal conductivity of 0.022, which is much lower than that of Comparative Example 2 (aerogel only, 0.035), Comparative Example 3 (ceramic only, 0.050), and Comparative Example 4 (glass only, 0.042). Although the thermal conductivity of Comparative Examples 5-7 (0.028-0.038) is better than that of a single filler, it is still inferior to that of Example 1 with the three materials combined. The breaking strength of Example 1 is 460N, which is higher than that of Comparative Example 2 (350N) and Comparative Example 4 (380N), and comparable to that of Comparative Example 3 (430N) and Comparative Example 7 (440N), but with better thermal insulation. This shows that the composite filler combination of graphene aerogel (ultra-low thermal conductivity) + hollow ceramic microspheres (rigidity enhancement, interface modification) + vacuum glass microspheres (vacuum insulation) forms a synergistic structure of "thermal insulation network - mechanical skeleton - vacuum barrier", achieving effects that cannot be achieved by single or pairwise combinations.

[0112] 2. Example 1 has a thermal conductivity of 0.022, which is better than Comparative Example 8 (impregnation only, no wet-process thermal insulation coating, 0.031). This demonstrates that the dual structure of the base fabric impregnation + wet-process thermal insulation coating allows the thermal insulation layer to extend from the internal fibers of the base fabric to the surface coating, forming a continuous and complete thermal insulation barrier, neither of which can be omitted.

[0113] 3. Comparative Example 9 (using ordinary silica aerogel) showed an increase in thermal conductivity to 0.032 and a decrease in tensile strength to 420 N, demonstrating that the three-dimensional porous network structure and ultra-high specific surface area of ​​graphene aerogel have an irreplaceable thermal insulation and enhancement effect.

[0114] 4. Comparative Example 10 (dry process without heat-insulating pigment) has a thermal conductivity of 0.027, slightly higher than Example 1 (0.022). This indicates that adding heat-insulating pigment to the dry process layer has a further auxiliary enhancing effect on surface heat insulation. Because Comparative Example 10 lacks heat-insulating pigment, the resin continuity is better, resulting in a slight increase in tensile strength.

[0115] In summary, this invention, through the dual structural design of wet impregnation and wet thermal insulation coating, and the synergistic effect of a ternary composite system of graphene aerogel, hollow ceramic microspheres, and vacuum glass microspheres, successfully prepared a high-thermal-insulation polyurethane synthetic leather with a thermal conductivity ≤0.025W / (m·K), a tensile strength ≥400N / 3cm, and a tear strength ≥40N / 3cm. Significant effects were achieved in terms of thermal insulation performance, mechanical properties, and abrasion resistance.

[0116] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-insulation polyurethane synthetic leather, characterized in that: Includes the following steps: S1. Impregnate the nonwoven fabric with the heat-insulating impregnation slurry to obtain the impregnated base fabric; the preparation process of the heat-insulating impregnation slurry is as follows: mix 100 parts of wet polyurethane resin, 200-300 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, and 3-5 parts of color paste, stir at 1500-2000 rpm for 15-20 min, let stand for degassing for 20-30 min, and obtain a heat-insulating impregnation slurry with a viscosity of 100-300 cps; S2. After extrusion, the impregnated base fabric is coated with a wet thermal insulation coating slurry. The preparation process of the wet thermal insulation coating slurry is as follows: 100 parts of wet polyurethane resin, 40-50 parts of DMF, 0.5-5 parts of graphene aerogel, 3-10 parts of hollow ceramic microspheres, 1-5 parts of vacuum glass microspheres, 1-2 parts of water-repellent agent, 0.5-0.8 parts of pore regulator, 0.5-0.8 parts of penetrant, and 1-3 parts of color paste are mixed and stirred at 1500-2000 rpm for 20-40 min, and then vacuum degassed for 60-70 min to obtain a wet thermal insulation coating slurry with a viscosity of 11000-14000 cps. S3. The base fabric after impregnation and coating is coagulated, washed, and dried to obtain a heat-insulating wet-process base. S4. Coat the release paper with adhesive layer slurry, middle layer heat insulation slurry and top layer abrasion slurry in sequence, and after drying, combine with the heat insulation wet process base to form a composite; S5. After drying, hot pressing and shaping, cooling, and peeling off the release paper, high heat insulation polyurethane synthetic leather is obtained.

2. The method for preparing high-heat-insulating polyurethane synthetic leather according to claim 1, characterized in that: The graphene aerogel has a three-dimensional porous network structure with a thermal conductivity ≤0.02 W / (m·K) and a specific surface area ≥800m² / g.

3. The method for preparing high-heat-insulating polyurethane synthetic leather according to claim 2, characterized in that: The hollow ceramic microspheres are alumina or zirconia-based hollow microspheres with a particle size of 10-80 μm and a wall thickness of 1-5 μm.

4. The method for preparing high-heat-insulating polyurethane synthetic leather according to claim 3, characterized in that: The vacuum glass microspheres are glass microspheres that are internally vacuum sealed, with a particle size of 20-100μm.

5. The method for preparing high-insulation polyurethane synthetic leather according to any one of claims 1-4, characterized in that: In step S2, the impregnated base fabric is squeezed by an extrusion roller to remove 80±5% of the slurry, and the doctor blade coating amount is 1.4±0.1kg / y.

6. The method for preparing high-heat-insulating polyurethane synthetic leather according to claim 5, characterized in that: In step S3, the coagulation and washing process uses a 15-30% DMF aqueous solution at a temperature of 25-35℃ for 10-15 minutes; the washing water temperature is 50-60℃ until the DMF residue is ≤0.1%.

7. The method for preparing high-insulation polyurethane synthetic leather according to claim 6, characterized in that: In step S4, the adhesive layer slurry comprises, by weight: 100 parts of adhesive polyurethane resin, 10-30 parts of DMF, and 10-20 parts of MEK, with a viscosity of 8000-10000 cps at 25°C.

8. The method for preparing high-insulation polyurethane synthetic leather according to claim 7, characterized in that: In step S4, the intermediate layer insulation slurry comprises, by weight: 100 parts of dry polyurethane resin, 30-80 parts of DMF, 10-40 parts of MEK, and 8-15 parts of insulation pigment, with a viscosity of 1800-2500 cps at 25°C.

9. The method for preparing high-insulation polyurethane synthetic leather according to claim 8, characterized in that: In step S4, the surface wear-resistant slurry comprises, by weight: 100 parts of dry polyurethane resin, 30-80 parts of DMF, 10-40 parts of MEK, 8-15 parts of heat-insulating pigment, 2-4 parts of wear-resistant additive, and 0.2-0.5 parts of antioxidant, with a viscosity of 1800-2500 cps at 25°C.

10. The method for preparing high-insulation polyurethane synthetic leather according to claim 1, characterized in that: The initial nonwoven fabric has a thickness of 0.65-0.75 mm, the impregnated base fabric has a thickness of 0.71-0.81 mm, the wet-process thermal insulation coating slurry has a coating thickness of 1.8-2.2 mm, the adhesive layer slurry has a coating thickness of 0.18-0.22 mm, the intermediate thermal insulation slurry has a coating thickness of 0.15-0.18 mm, and the surface wear-resistant slurry has a coating thickness of 0.12-0.15 mm.