High-flatness air layer polyurethane leather for coating and preparation method of high-flatness air layer polyurethane leather

Abstract

The invention relates to the field of polyurethane leather materials, and particularly discloses high-flatness air layer polyurethane leather for coating and a preparation method of the high-flatness air layer polyurethane leather. The high-flatness air layer polyurethane leather for coating comprises an air cloth layer, a bonding layer, a polyurethane composite film layer and a coating layer are sequentially compounded on the surface of the air cloth layer, the air cloth layer comprises two layers of base cloth and polyester fibers, the polyester fibers are located between the two layers of base cloth, the corresponding sides of the two layers of base cloth are connected with the polyester fibers, and the coating layer is arranged between the two layers of base cloth. An air structure of 0.1-1mm is formed between the two layers of base cloth, and the air cloth layer is subjected to water repellent treatment. According to the high-flatness air layer polyurethane leather for coating, the unevenness of an automobile interior framework can be absorbed through an air structure between the air cloth layers, and the polyurethane leather coating surface is made to have the flat and smooth effect.

Description

Technical Field

[0001] The present application relates to the field of polyurethane leather materials, and more specifically, to an air layer polyurethane leather for high-flatness coating and a preparation method thereof. Background Art

[0002] In order to improve the beauty and comfort of car interiors, plain interior leather is used in car seats, door panels, etc. Interior leather can improve the durability and cleanability of car interiors. Interior leather can also improve the personalization and customization of car interiors. Different plain designs can be selected according to different styles and preferences, making the car interior more unique and personalized.

[0003] However, the application of plain interior leather in automobiles usually requires professional covering technology and maintenance. Due to the uneven glue of the automobile interior frame, it is very easy to highlight the imprint defects on the surface of the flat interior leather during the covering and pressing process, causing the interior leather to deform and affect the appearance and comfort of the interior leather. Summary of the invention

[0004] In order to improve the influence of the unevenness of the traditional automobile interior frame on the automobile interior leather, the present application provides an air layer polyurethane leather for high-flatness coating and a preparation method thereof.

[0005] In the first aspect, the present application provides an air layer polyurethane leather for high flatness coating, which adopts the following technical solution: A high-flatness air layer polyurethane leather for coating comprises an air cloth layer, wherein the surface of the air cloth layer is compounded with an adhesive layer, a polyurethane composite film layer and a finishing layer in sequence, wherein the air cloth layer comprises two layers of base cloth and polyester fiber, wherein the polyester fiber is located between the two layers of base cloth, and the corresponding sides of the two layers of base cloth are connected to the polyester fiber, and an air structure of 0.1-1 mm is formed between the two layers of base cloth, wherein the air cloth layer is treated with water repellency, and the water repellent finishing agent comprises the following raw materials in parts by weight: 20-30 parts of dodecafluoroheptyl methacrylate, 30-40 parts of methyl methacrylate, 20-30 parts of acrylic acid, 10-15 parts of vinyl silicone oil, 15-18 parts of functional silicone monomer, 0.8-1 part of initiator, 1-3 parts of water repellent crosslinking agent, 1-3 parts of emulsifier, 5-10 parts of tetraethyl orthosilicate, and 0.3-0.5 parts of ammonia water.

[0006] By adopting the above technical solution, the two layers of base fabric are connected by polyester fibers in the middle to form an air structure at a certain distance, achieving a spatial effect similar to 3D fabric. When polyurethane leather is used to cover automotive interior parts, the slight unevenness of the bottom can be absorbed by the spatial structure, thereby promoting the polyurethane leather covering surface to have a flat and smooth appearance, improving the flatness and comfort of the polyurethane leather covering. The air cloth layer is subjected to water-repellent finishing, which can reduce the erosion of the polyurethane leather surface by the humid environment, reduce the liquid from entering the polyurethane leather through the air cloth layer, reduce the deformation, fading, and aging of the polyurethane leather caused by the humid environment, and thus improve the comfort and appearance of the polyurethane leather covering.

[0007] With functional silicone monomer, dodecafluoroheptyl methacrylate, and vinyl silicone oil as the shell structure, and methyl methacrylate and acrylic acid as the core structure, the acrylate monomer undergoes polymerization reaction on the surface of the silicone monomer, and at the same time, the acrylate monomer and the silicone monomer undergo bonding reaction, thereby forming a water-repellent finishing agent with a stable core-shell structure. Dodecafluoroheptyl methacrylate contains fluorine elements, has strong hydrophobicity and lipophilicity, and can form a water-repellent protective film similar to a lubricant on the surface of the base fabric, preventing the penetration of liquids, playing a role in water repellency and anti-fouling, improving the water-repellent effect of the air cloth layer, and thereby reducing the erosion of liquids on polyurethane leather. The larger silicon-oxygen bond energy and lower surface tension of the functional silicone monomer are used to improve the durability of the water-repellent protective film on the surface of the air cloth layer, so that the water-repellent finishing agent can be firmly combined with the base fabric fibers, and the density of the water-repellent protective film and the thermal stability of the protective film are enhanced. Vinyl silicone oil can enhance the softness and smoothness of the surface of the base fabric fibers, thereby enhancing the water-repellent effect and softness of the air cloth layer, reducing the liquid from entering the interior of the polyurethane leather through the air cloth layer, and improving the water-repellent and waterproof effects of the polyurethane leather. Nano-silica particles are formed in a water-repellent finishing agent system by using tetraethyl orthosilicate and ammonia water. The surface modification effect of the silica particles by functional silicone monomers is utilized to introduce the nano-silica particles into the polymerization reaction of acrylate monomers, thereby promoting covalent bond between the nano-silica particles and the acrylate monomers, thereby improving the water-repellent effect and thermal stability of the water-repellent finishing agent, enhancing the thermal stability of polyurethane leather, and reducing the deformation of polyurethane leather during high-temperature processing in the later stage.

[0008] Preferably, the functional silicone monomer is at least one of vinyl trimethoxy silane, γ-methacryloxypropyl tri(trimethylsiloxy)silane and γ-glycidyloxypropyl trimethoxy silane.

[0009] By adopting the above technical scheme, vinyl trimethoxysilane, tri(γ-aminopropyl) trimethoxysilane and γ-glycidyloxypropyl trimethoxysilane are added to the water-repellent finishing agent, which can reduce the surface free energy and surface tension of the water-repellent finishing agent, enable the water-repellent finishing agent to be firmly bonded to the surface of the fabric, further enhance the water-repellent effect of the air cloth layer, and reduce the erosion of external liquids on the polyurethane leather.

[0010] Preferably, the polyurethane composite film layer includes a first polyurethane surface layer and a second polyurethane surface layer, the first polyurethane surface layer is located between the adhesive layer and the second polyurethane surface layer, the first polyurethane surface layer and the second polyurethane surface layer are both made of a polyurethane surface layer mixture, and the polyurethane surface layer mixture includes the following raw materials in parts by weight: 95-105 parts of polyurethane resin, 60-65 parts of N,N-dimethylformamide, 10-15 parts of ethyl acetate, and 19-25 parts of color paste.

[0011] By adopting the above technical solution, the use of a double-layer polyurethane surface layer can fill the tiny depressions and unevenness on the surface of the polyurethane leather, making the prepared polyurethane leather flatter and smoother after coating. The first polyurethane surface layer forms a base layer on the surface of the air cloth layer to fill the tiny pores and unevenness caused by the car interior frame. The second polyurethane surface layer can form a flatter and more delicate surface layer on the basis of the first polyurethane surface layer, and form a solid protective layer on the surface of the air cloth layer, making the surface of the polyurethane leather flatter and smoother after coating. At the same time, the use of a double-layer polyurethane surface layer can enhance the wear resistance, durability and wrinkle resistance of the polyurethane leather, and extend the service life of the polyurethane leather.

[0012] Preferably, the adhesive layer comprises the following raw materials in parts by weight: 95-105 parts of solvent-free adhesive A, 48-70 parts of solvent-free adhesive B, 0.04-0.06 parts of accelerator, 0.18-0.3 parts of curing agent, 0.15-0.25 parts of leveling agent, and 35-50 parts of flame retardant; wherein the solvent-free adhesive A is polyester polyol, and the solvent-free adhesive B is isocyanate prepolymer.

[0013] Preferably, the finishing layer comprises the following raw materials in parts by weight: 40-60 parts of semi-bright matte surface treatment agent, 45-60 parts of matte surface treatment agent, 8-16 parts of hand feel and wear resistance agent, 0.2-0.3 parts of defoaming agent, 0.8-1 parts of leveling agent, 5-7 parts of cross-linking agent, and 25-40 parts of water.

[0014] In a second aspect, the present application provides a method for preparing an air layer polyurethane leather for high flatness coating, which adopts the following technical scheme and includes the following specific steps: On the corresponding side of the two layers of base fabric, polyester fibers are connected between the two layers of base fabric by weft knitting to form an air fabric layer, and then the air fabric layer is subjected to water-repellent finishing; The polyurethane composite film layer is compounded with the release paper and then bonded with the adhesive layer. The side of the adhesive layer facing away from the polyurethane composite film layer is then bonded with the air cloth layer. After step-by-step heating and drying, the release paper is separated and a coating layer is compounded on the surface of the polyurethane composite film layer to form a high-flatness air layer polyurethane leather for covering.

[0015] By adopting the above technical solution, the prepared polyurethane leather covering surface has good flatness and comfort, can absorb the unevenness of the automobile interior frame, and improve the flatness and comfort of the plain interior leather.

[0016] Preferably, the step-wise temperature increase range is 135-145° C., and the drying time is 12-10 min.

[0017] Preferably, methyl methacrylate, acrylic acid, a crosslinking agent, an emulsifier, tetraethyl orthosilicate, ammonia water and an initiator are mixed and dissolved in water to form a pre-emulsion, dodecafluoroheptyl methacrylate, vinyl silicone oil and a functional silicone monomer are added to the pre-emulsion and mixed evenly, and the water-repellent finishing agent is formed after heating and reaction; Then the water-repellent finishing agent is mixed with water to form a water-repellent finishing liquid, the air-through cloth is immersed in the water-repellent finishing liquid, the air-through cloth is taken out after two immersions and two rollings, and pre-baking and baking are performed in sequence to complete the water-repellent finishing of the air-through cloth.

[0018] By adopting the above technical scheme, the prepared water-repellent finishing agent can be firmly bonded to the surface of the fabric under the synergistic effect of various components, forming a strong water-repellent protective film on the air cloth layer, reducing the erosion of liquid on polyurethane leather, reducing the deformation of polyurethane leather caused by humid environment, and improving the durability of polyurethane leather used in automobile interiors.

[0019] In summary, this application has the following beneficial effects: 1. Since the present application utilizes the air structure of the air cloth layer to achieve a 3D spatial effect, it absorbs the flatness caused by the bottom of the car interior frame, and promotes the polyurethane leather to meet the requirements of flatness and smoothness when wrapped, thereby improving the flatness and comfort of the polyurethane leather used in the car interior. At the same time, the air cloth layer is treated with water-repellent finishing to reduce the erosion of liquid on the polyurethane leather, and reduce the deformation and fading of the polyurethane leather caused by the humid environment.

[0020] 2. In this application, under the synergistic effect of various components, a silicon-containing acrylic water-repellent finishing agent with a stable core-shell structure is formed, which can be firmly combined with the air cloth layer to form a stable and dense water-repellent protective film on the surface of the air cloth layer, thereby reducing the erosion of the air cloth layer by external liquids and enhancing the water resistance and durability of the polyurethane leather. DETAILED DESCRIPTION

[0021] The present application is further described in detail below with reference to the embodiments.

[0022] The initiator is a conventional initiator for acrylate polymerization reaction, and in this embodiment, it is potassium persulfate.

[0023] The water-repellent crosslinking agent is glycidyl methacrylate.

[0024] The emulsifier is alkylphenol polyoxyethylene ether.

[0025] The polyester polyol was selected from BASF 100C-A.

[0026] The isocyanate prepolymer was selected from BASF 100C-B.

[0027] The accelerator is stannous 2-ethylhexanoate.

[0028] The leveling agent is BYK9565.

[0029] Sodium ammonium phosphate is selected as the flame retardant.

[0030] The semi-bright matte surface treatment agent is Degussa model TS-100.

[0031] The matte surface treatment agent is Degussa OK-412.

[0032] For the anti-wear agent, choose DOW-FBL-3289.

[0033] The defoamer selected is BYK-054.

[0034] The crosslinker selected was Stahl XR-5580.

[0035] The color paste is aniline black.

[0036] BASF Luwax AF31 was selected as the polyurethane resin.

[0037] Preparation Example 1 The water-repellent finishing agent includes the following raw materials in parts by weight: 25 kg of dodecafluoroheptyl methacrylate, 35 kg of methyl methacrylate, 25 kg of acrylic acid, 13 kg of vinyl silicone oil, 17 kg of functional silicone monomer, 0.9 kg of initiator, 2 kg of crosslinking agent, and 2 kg of emulsifier. The functional silicone monomer is γ-methacryloxypropyl tris(trimethylsiloxy)silane.

[0038] The preparation method of the water-repellent finishing agent comprises the following specific steps: S1: Methyl methacrylate, acrylic acid, a crosslinking agent, half the mass of an emulsifier and half the mass of an initiator are mixed to form a mixed solution A, and then the mixed solution A is mixed with water in a mass ratio of water to mixed solution A of 4:1, and stirred at a speed of 500 r / min for 0.5 h to form a pre-emulsion A.

[0039] S2: Dodecafluoroheptyl methacrylate, vinyl silicone oil, functional silicone monomer, remaining emulsifier and remaining initiator are mixed, and stirred at a speed of 500 r / min for 0.5 h to form a mixed solution B, and then the mixed solution B is mixed with water in a mass ratio of water to mixed solution B of 4:1 to form a pre-emulsion solution B.

[0040] S3: Then heat half the mass of pre-emulsion A to 65°C for reaction, add the remaining pre-emulsion A after the reaction system turns blue and stabilizes, then add pre-emulsion B, keep the temperature for reaction for 1 hour, cool to 40°C, filter the discharged material, and obtain a water-repellent finishing agent.

[0041] Preparation Example 2 The difference between Preparation Example 2 and Preparation Example 1 is that the amount of dodecafluoroheptyl methacrylate used in the water-repellent finishing agent raw materials is 20 kg, the amount of methyl methacrylate used is 30 kg, the amount of acrylic acid used is 30 kg, the amount of vinyl silicone oil used is 15 kg, the amount of functional silicone monomer used is 18 kg, the amount of initiator used is 0.8 kg, the amount of cross-linking agent used is 1 kg, and the amount of emulsifier used is 3 kg.

[0042] Preparation Example 3 The difference between Preparation Example 3 and Preparation Example 1 is that the amount of dodecafluoroheptyl methacrylate used in the water-repellent finishing agent raw materials is 30 kg, the amount of methyl methacrylate used is 40 kg, the amount of acrylic acid used is 20 kg, the amount of vinyl silicone oil used is 10 kg, the amount of functional silicone monomer used is 15 kg, the amount of initiator used is 1 kg, the amount of cross-linking agent used is 3 kg, and the amount of emulsifier used is 1 kg.

[0043] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that the functional silicone monomer in the raw material of the water-repellent finishing agent is vinyltrimethoxysilane.

[0044] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 1 is that the functional silicone monomer in the water-repellent finishing agent raw material is γ-glycidyloxypropyltrimethoxysilane.

[0045] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 1 is that no functional silicone monomer is used in the raw material of the water-repellent finishing agent.

[0046] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 1 is that no functional organic silicone monomer and vinyl silicone oil are used in the raw materials of the water-repellent finishing agent.

[0047] The preparation method of the water-repellent finishing agent comprises the following specific steps: Dodecafluoroheptyl methacrylate, methyl methacrylate, acrylic acid, a crosslinking agent, half the mass of an emulsifier and half the mass of an initiator are mixed to form a mixed solution, and then the mixed solution is mixed with water, the mass ratio of water to the mixed solution is 4:1, and stirred at a speed of 500r / min for 0.5h to form a pre-emulsion, and then half the mass of the pre-emulsion is heated to 65°C for reaction, and the remaining pre-emulsion is added after the reaction system turns blue and stable, and the reaction is kept warm for 1h, cooled to 40°C, and the material is filtered to obtain a water-repellent finishing agent.

[0048] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 1 is that the raw materials of the water-repellent finishing agent further include 8 kg of tetraethyl orthosilicate and 0.4 kg of ammonia water.

[0049] The preparation method of the water-repellent finishing agent comprises the following specific steps: S1: Methyl methacrylate, acrylic acid, a crosslinking agent, half the mass of an emulsifier and half the mass of an initiator are mixed to form a mixed solution A, and then the mixed solution A is mixed with water, the mass ratio of water to the mixed solution A is 4:1, and stirred at a speed of 500 r / min for 0.5 h to form a pre-emulsion liquid A, and then ethyl orthosilicate is added dropwise to the pre-emulsion liquid A, and then ammonia water is added, and the mixture is heated to 35°C for reaction for 6 h to obtain a composite liquid A.

[0050] S2: Dodecafluoroheptyl methacrylate, vinyl silicone oil, functional silicone monomer, remaining emulsifier and remaining initiator are mixed, and stirred at a speed of 500 r / min for 0.5 h to form a mixed solution B, and then the mixed solution B is mixed with water in a mass ratio of water to mixed solution B of 4:1 to form a pre-emulsion solution B.

[0051] S3: Then heat half of the mass of the composite liquid A to 65°C for reaction. After the reaction system turns blue and stabilizes, add the remaining composite liquid A, then add the pre-emulsified liquid B, keep the temperature for reaction for 1 hour, cool to 40°C, filter the discharged material, and obtain a water-repellent finishing agent.

[0052] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 8 is that the amount of ethyl orthosilicate used in the water-repellent finishing agent raw material is 5 kg, and the amount of ammonia water used is 0.3 kg.

[0053] Preparation Example 10 The difference between Preparation Example 10 and Preparation Example 8 is that the amount of ethyl orthosilicate used in the water-repellent finishing agent raw material is 10 kg, and the amount of ammonia water used is 0.5 kg.

[0054] Preparation Example 11 The difference between Preparation Example 11 and Preparation Example 8 is that no functional silicone monomer is used in the raw material of the water-repellent finishing agent. Example Example

[0055] The present embodiment provides an air layer polyurethane leather for high-flatness coating, including an air cloth layer, the surface of the air cloth layer is coated with an adhesive layer, a polyurethane composite film layer, and a coating layer in sequence, the air cloth layer includes two layers of base cloth and polyester fiber, the base cloth is an ordinary commercially available non-woven fabric, and the air cloth layer is treated with a water-repellent finishing agent, wherein the water-repellent finishing agent comes from Preparation Example 1.

[0056] The adhesive layer includes the following raw materials in parts by weight: 100 kg of solvent-free adhesive A, 59 kg of solvent-free adhesive B, 0.05 kg of accelerator, 0.24 kg of curing agent, 0.2 kg of leveling agent, and 43 kg of flame retardant; the solvent-free adhesive A is polyester polyol, and the solvent-free adhesive B is isocyanate prepolymer.

[0057] The polyurethane composite film layer includes a first polyurethane surface layer and a second polyurethane surface layer. The first polyurethane surface layer and the second polyurethane surface layer are both made of a polyurethane surface layer mixture. The polyurethane surface layer mixture includes the following raw materials in parts by weight: 100 kg of polyurethane resin, 63 kg of N,N-dimethylformamide, 13 kg of ethyl acetate, and 22 kg of color paste.

[0058] The finishing layer includes the following raw materials in parts by weight: 50 kg of semi-bright matte surface treatment agent, 53 kg of matte surface treatment agent, 12 kg of hand-feel wear-resistant agent, 0.25 kg of defoaming agent, 0.9 kg of leveling agent, 6 kg of cross-linking agent, and 33 kg of water.

[0059] The method for preparing air layer polyurethane leather for high flatness coating comprises the following specific steps: S1: The polyester fiber is connected in the middle of the two layers of base fabric by weft knitting on the corresponding side of the two layers of base fabric, forming a space structure with a width of 0.1-1mm between the two layers of base fabric, and the weight is 250g / m 2 The air cloth layer is then mixed with water to form a water-repellent finishing liquid with a water-repellent finishing agent mass concentration of 60g / L, the air cloth layer is immersed in the water-repellent finishing liquid, twice immersed and twice rolled, the rolling rate is 100%, the air cloth layer is taken out, pre-baked at 100℃ for 2min, and then baked at 120℃ for 3min to complete the water-repellent finishing of the air cloth layer.

[0060] S2: Mix polyurethane resin, N,N-dimethylformamide, ethyl acetate and color paste, stir evenly to form a polyurethane surface layer mixture, then take a plain release paper, apply the polyurethane surface layer mixture on the release paper, the coating thickness is controlled at 0.15±0.01mm, the vehicle speed is controlled at (11±1) m / min, heat and dry, the oven is heated in a step-by-step manner, the temperatures are 70 / 80 / 100 / 110 / 125 / 125°C, and the drying time is 4 minutes in total to obtain the polyurethane second surface layer; then apply the same weight of the polyurethane surface layer mixture on the surface of the first polyurethane surface layer, the coating thickness is 0.20±0.01mm, the vehicle speed is controlled at (11±1) m / min, heat and dry, the oven is heated in a step-by-step manner, the temperatures are 70 / 80 / 100 / 110 / 125 / 125°C, and the drying time is 4 minutes in total to obtain the first polyurethane surface layer, that is, the polyurethane composite film layer.

[0061] S3: Mix solvent-free adhesive A, solvent-free adhesive B, accelerator, curing agent, leveling agent and flame retardant evenly to form an adhesive layer mixture, and then apply the adhesive layer mixture on the surface of the first polyurethane surface layer, control the coating thickness to 0.25±0.01mm, control the vehicle speed to (10±1) m / min, heat and dry, use the oven to increase the temperature in a step-by-step manner, the temperature is 100 / 100 / 100 / 110 / 125 / 125℃, bake for 2min, the adhesive layer is semi-dry, then attach the air cloth layer, dry, use the oven to increase the temperature in a step-by-step manner, the temperature is 135 / 135 / 135 / 140 / 140 / 140 / 140 / 140 / 145 / 145 / 145 / 145℃, the drying time is 12min, and then separate the release paper to form a polyurethane leather semi-finished product.

[0062] S4: Mix semi-bright matte surface treatment agent, matte surface treatment agent, hand feel and wear-resistant agent, defoaming agent, leveling agent, cross-linking agent and water to form a coating layer mixture, and then apply the coating layer mixture on the surface of the second polyurethane surface layer of the polyurethane leather semi-finished product, control the coating thickness to 0.1±0.01mm, control the vehicle speed to (10±1) m / min, heat and dry, and increase the temperature in an oven in a step-by-step manner at temperatures of 125 / 130 / 130 / 130 / 130 / 130°C, bake for 2 minutes, and curl after drying to obtain an air layer polyurethane leather for high-flatness coating. Example

[0063] The difference between Example 2 and Example 1 is that the amount of solvent-free adhesive A in the bonding layer raw materials of the air layer polyurethane leather for high-flatness coating is 95 kg, the amount of solvent-free adhesive B is 48 kg, the amount of accelerator is 0.04 kg, the amount of curing agent is 0.18 kg, the amount of leveling agent is 0.15 kg, and the amount of flame retardant is 35 kg. Example

[0064] The difference between Example 3 and Example 1 is that the amount of solvent-free adhesive A used in the bonding layer raw materials of the air layer polyurethane leather for high-flatness coating is 105kg, the amount of solvent-free adhesive B used is 70kg, the amount of accelerator used is 0.06kg, the amount of curing agent used is 0.3kg, the amount of leveling agent used is 0.25kg, and the amount of flame retardant used is 50kg. Example

[0065] The difference between Example 4 and Example 1 is that the amount of polyurethane resin used in the polyurethane surface layer mixture raw materials in the air layer polyurethane leather for high flatness coating is 95kg, the amount of N,N-dimethylformamide used is 60kg, the amount of ethyl acetate used is 10kg, and the amount of color paste used is 19kg. Example

[0066] The difference between Example 5 and Example 1 is that the amount of polyurethane resin used in the polyurethane surface layer mixture raw materials of the air layer polyurethane leather for high flatness coating is 105kg, the amount of N,N-dimethylformamide used is 65kg, the amount of ethyl acetate used is 15kg, and the amount of color paste used is 25kg. Example

[0067] The difference between Example 6 and Example 1 is that the amount of semi-bright matte surface treatment agent used in the coating layer raw materials of the air layer polyurethane leather for high flatness coating is 40kg, the amount of matte surface treatment agent used is 60kg, the amount of hand feel and wear-resistant agent used is 8kg, the amount of defoaming agent used is 0.3kg, the amount of leveling agent used is 1kg, the amount of cross-linking agent used is 5kg, and the amount of water used is 25kg. Example

[0068] The difference between Example 7 and Example 1 is that the amount of semi-bright matte surface treatment agent used in the coating layer raw materials of the air layer polyurethane leather for high flatness coating is 60kg, the amount of matte surface treatment agent used is 45kg, the amount of hand feel and wear-resistant agent used is 16kg, the amount of defoaming agent used is 0.2kg, the amount of leveling agent used is 8kg, the amount of cross-linking agent used is 7kg, and the amount of water used is 40kg. Example

[0069] The difference between Example 8 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 2. Example

[0070] The difference between Example 9 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 3. Example

[0071] The difference between Example 10 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 4. Example

[0072] The difference between Example 11 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 5. Example

[0073] The difference between Example 12 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 6. Example

[0074] The difference between Example 13 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 7. Example

[0075] The difference between Example 14 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 8. Example

[0076] The difference between Example 15 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 9. Example

[0077] The difference between Example 16 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 10. Example

[0078] The difference between Example 17 and Example 1 is that the water-repellent finishing agent used in the air layer of the air layer polyurethane leather for high flatness coating comes from Preparation Example 11.

[0079] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that a single layer of non-woven fabric is used instead of the air fabric layer in the air layer polyurethane leather for high flatness coating.

[0080] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the air fabric layer in the air layer polyurethane leather for high flatness coating is not subjected to water repellent treatment.

[0081] The following performance tests were conducted on the air layer polyurethane leather for high flatness coating provided by Examples 1-17 and Comparative Examples 1-2 of the present application. The specific test results are shown in Table 1.

[0082] 1. Water repellency The water repellency of the polyurethane leather prepared in this application was tested with reference to the standard of GBT4745-2012 "Testing and evaluating the waterproof performance of textiles - Water-impregnating method".

[0083] 2. Peel strength Referring to the standard of GBT8808-1988 "Peeling test method for soft composite plastic materials", the B method sample size was adopted to test the peeling strength between the polyurethane leather prepared in this application and the spray-coated part of the automobile.

[0084] 3. Package Effect The polyurethane leather spray adhesive prepared in the present application is coated on the frame of automobile parts, and the coating effect and flatness of the polyurethane leather surface are observed.

[0085] Table 1: Performance test data table Example Water repellency grade (level) Peel strength N / m Wrapping effect Example 1 4-5 1083 Smooth surface Example 2 / 1078 / Example 3 / 1089 / Example 4 / 1075 / Example 5 / 1086 / Example 6 / 1080 / Example 7 / 1086 / Example 8 4-5 1081 / Example 9 4-5 1082 / Example 10 4-5 1085 / Embodiment 11 4-5 1090 Smooth surface Example 12 Level 4 1070 Smooth surface Example 13 Level 3-4 1023 Smooth surface Embodiment 14 Level 5 1167 Smooth surface Embodiment 15 Level 5 1160 Smooth surface Example 16 Level 5 1165 Smooth surface Embodiment 17 Level 4 1095 Smooth surface Comparative Example 1 Level 2 856 The surface is bumpy Comparative Example 2 Level 1 915 The surface is bumpy It can be seen from the performance test results that the polyurethane leather prepared in the present application can maintain a smooth appearance when covering the car interior under the synergistic effect of various components. At the same time, through the water-repellent treatment of the air cloth layer, the water-repellent effect and peel strength of the polyurethane leather are enhanced, and the deformation and falling off of the polyurethane leather in a humid environment are reduced.

[0086] By comparing Example 12, Example 13 and Example 1, it can be seen that no functional silicone monomer is used in the water-repellent finishing agent of Example 12, and no functional silicone monomer is used in the water-repellent finishing agent of Example 13. From the performance test results, it can be seen that the water-repellent grade of the prepared polyurethane leather is significantly reduced.

[0087] It can be seen from Examples 14-16 that adding an appropriate amount of silicon dioxide to the water-repellent finishing agent can improve the water-repellent effect of polyurethane and enhance the strength of polyurethane.

[0088] By comparing Example 17 with Example 14, it can be seen that Example 14 does not use a functional silicone monomer, which may be because the bonding force between silica and the air cloth layer is reduced, thereby causing the water repellency level of the polyurethane leather to decrease.

[0089] By comparing Comparative Examples 1 and 2 with Example 1, it can be seen that in Comparative Example 1, conventional non-woven fabric is used instead of the air fabric layer. When the auto parts are spray-coated, the unevenness of the skeleton glue causes the surface of the polyurethane leather coating to be more concave and convex. At the same time, the peeling strength between the polyurethane leather and the skeleton is also reduced, which easily causes the polyurethane leather to fall off and the comfort of the polyurethane leather coating to decrease. In Comparative Example 2, the air fabric layer is not subjected to water-repellent finishing, which results in a decrease in the peeling strength between the polyurethane leather and the auto parts, which causes the polyurethane leather to be easily deformed and fall off due to moisture.

[0090] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A high-flatness air layer polyurethane leather for coating, characterized in that: The invention comprises an air cloth layer, the surface of which is compounded with an adhesive layer, a polyurethane composite film layer and a finishing layer in sequence, the air cloth layer comprises two layers of base cloth and polyester fiber, the polyester fiber is located between the two layers of base cloth, the corresponding sides of the two layers of base cloth are connected to the polyester fiber, an air structure of 0.1-1 mm is formed between the two layers of base cloth, the air layer is water-repellent treated by a water-repellent finishing agent, and the water-repellent finishing agent comprises the following raw materials in parts by weight: 20-30 parts of dodecafluoroheptyl methacrylate, 30-40 parts of methyl methacrylate, 20-30 parts of acrylic acid, 10-15 parts of vinyl silicone oil, 15-18 parts of functional silicone monomer, 0.8-1 part of initiator, 1-3 parts of water-repellent crosslinking agent, 1-3 parts of emulsifier, 5-10 parts of tetraethyl orthosilicate and 0.3-0.5 parts of ammonia water.

2. The high-flatness air layer polyurethane leather for coating according to claim 1, characterized in that: The polyurethane composite film layer includes a first polyurethane surface layer and a second polyurethane surface layer, wherein the first polyurethane surface layer is located between the adhesive layer and the second polyurethane surface layer, and the first polyurethane surface layer and the second polyurethane surface layer are both made of a polyurethane surface layer mixture, wherein the polyurethane surface layer mixture includes the following raw materials in parts by weight: 95-105 parts of polyurethane resin, 60-65 parts of N,N-dimethylformamide, 10-15 parts of ethyl acetate, and 19-25 parts of color paste.

3. The high-flatness air layer polyurethane leather for coating according to claim 1, characterized in that: The adhesive layer comprises the following raw materials in parts by weight: 95-105 parts of solvent-free adhesive material A, 48-70 parts of solvent-free adhesive material B, 0.04-0.06 parts of accelerator, 0.18-0.3 parts of curing agent, 0.15-0.25 parts of leveling agent, and 35-50 parts of flame retardant; The solvent-free adhesive material A is polyester polyol, and the solvent-free adhesive material B is isocyanate prepolymer.

4. The high-flatness air layer polyurethane leather for coating according to claim 1, characterized in that: The coating layer comprises the following raw materials in parts by weight: 40-60 parts of semi-bright matte surface treatment agent, 45-60 parts of matte surface treatment agent, 8-16 parts of hand-feel wear-resistant agent, 0.2-0.3 parts of defoaming agent, 0.8-1 parts of leveling agent, 5-7 parts of cross-linking agent and 25-40 parts of water.

5. A method for preparing the air layer polyurethane leather for high flatness coating according to any one of claims 1 to 4, characterized in that: The specific steps include: On the corresponding side of the two layers of base fabric, polyester fibers are connected between the two layers of base fabric by weft knitting to form an air fabric layer, and then the air fabric layer is subjected to water-repellent finishing; The polyurethane composite film layer is compounded with the release paper and then bonded with the adhesive layer. The side of the adhesive layer facing away from the polyurethane composite film layer is bonded with the air cloth layer. After step-by-step heating and drying, the release paper is separated. A coating layer is compounded on the surface of the polyurethane composite film layer to form a high-flatness air layer polyurethane leather for covering.

6. The method for preparing the air layer polyurethane leather for high flatness coating according to claim 5, characterized in that: The step-wise temperature rise range is 135-145° C., and the drying time is 12-10 minutes.

7. The method for preparing the air layer polyurethane leather for high flatness coating according to claim 5, characterized in that: Methyl methacrylate, acrylic acid, a crosslinking agent, an emulsifier, tetraethyl orthosilicate, ammonia water and an initiator are mixed and dissolved in water to form a pre-emulsion, dodecafluoroheptyl methacrylate, vinyl silicone oil and a functional silicone monomer are added to the pre-emulsion and mixed evenly, and a water-repellent finishing agent is formed after heating and reaction; Then the water-repellent finishing agent is mixed with water to form a water-repellent finishing liquid, the air-through cloth is immersed in the water-repellent finishing liquid, the air-through cloth is taken out after two immersions and two rollings, and pre-baking and baking are performed in sequence to complete the water-repellent finishing of the air-through cloth.