High flatness air layer polyurethane leather for covering and its preparation method

Abstract

The application relates to the field of polyurethane leather materials, and particularly discloses an air-layer polyurethane leather for high-flatness coating and a preparation method thereof. The air-layer polyurethane leather for high-flatness coating comprises an air cloth layer, the surface of the air cloth layer is sequentially compounded with an adhesive layer, a polyurethane composite film layer and a finishing layer, the air cloth layer comprises two base cloths and polyester fibers, the polyester fibers are located in the middle of the two base cloths, one side of the two base cloths is connected with the polyester fibers, an air structure with a thickness of 0.1-1 mm is formed between the two base cloths, and the air cloth layer is subjected to water-repellent treatment. The air-layer polyurethane leather for high-flatness coating can absorb the unevenness of an automobile interior framework through the air structure between the air cloth layers, so that the polyurethane leather coating surface has a flat and smooth effect.

Description

TECHNICAL FIELD

[0001] The application relates to the field of polyurethane leather materials, in particular to an air layer polyurethane leather for high flatness coating and a preparation method thereof. BACKGROUND

[0002] In order to improve the aesthetics and comfort of automobile interiors, plain leather is applied to automobile seats, door panels and the like, the interior leather can improve the durability and easy cleaning of the automobile interior, and the interior leather can improve the personalization and customization of the automobile interior, different plain designs can be selected according to different styles and preferences, so as to make the automobile interior more unique and personalized.

[0003] However, the plain interior leather usually needs professional coating process and maintenance in the application of the automobile, and due to the unevenness of the automobile interior skeleton glue, the printing marks are easily highlighted on the surface of the plain interior leather in the coating and pressing process, which causes the deformation of the interior leather and affects the appearance and comfort of the interior leather. SUMMARY

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

[0005] In a first aspect, the application provides an air layer polyurethane leather for high flatness coating, which adopts the following technical scheme:

[0006] An air layer polyurethane leather for high flatness coating, comprising an air cloth layer, the surface of the air cloth layer is sequentially compounded with an adhesive layer, a polyurethane composite film layer and a finishing layer, the air cloth layer comprises two base cloths and polyester fibers, the polyester fibers are located in the middle of the two base cloths, one side of the two base cloths corresponding to the polyester fibers is connected, an air structure of 0.1-1mm is formed between the two base cloths, the air cloth layer is subjected to water repellent treatment, the water repellent finishing agent comprises the following raw materials by weight: methyl methacrylate 20-30 parts, methyl methacrylate 30-40 parts, acrylic acid 20-30 parts, vinyl silicone oil 10-15 parts, functional organic silicon monomer 15-18 parts, initiator 0.8-1 part, water repellent crosslinking agent 1-3 parts, emulsifier 1-3 parts, ethyl silicate 5-10 parts, and ammonia 0.3-0.5 parts.

[0007] By adopting this technical solution, the two layers of base fabric are connected by polyester fibers, forming 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, slight unevenness on the bottom can be absorbed by the air structure, thereby giving the polyurethane leather covering a flat and smooth appearance, improving the flatness and comfort of the polyurethane leather covering. The air layer of fabric is treated with a water-repellent finish to reduce the erosion of the polyurethane leather surface in a humid environment, reduce the ingress of liquids through the air layer, and reduce the deformation, fading, and aging of the polyurethane leather caused by humid environments, thereby improving the comfort and appearance of the polyurethane leather covering.

[0008] The water-repellent finish comprises a 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 on the surface of the silicone monomer, while simultaneously bonding with the silicone monomer to form a stable core-shell structure. Dodecafluoroheptyl methacrylate, containing fluorine, exhibits strong hydrophobic and oleophilic properties, forming a lubricant-like water-repellent protective film on the base fabric surface. This prevents liquid penetration, acts as a water repellent and anti-fouling agent, and enhances the water repellency of the air layer, thereby reducing liquid corrosion on polyurethane leather. The high silane-oxygen bond energy and low surface tension of the functional silicone monomer enhance the durability of the water-repellent protective film on the air layer, allowing the water-repellent finish to firmly bond to the base fabric fibers, increasing the film's density and thermal stability. The vinyl silicone oil enhances the softness and smoothness of the base fabric fiber surface, further enhancing the water repellency and softness of the air layer, reducing liquid penetration through the air layer into the polyurethane leather interior, and improving the polyurethane leather's water and water repellency. Nano-silica particles are formed in a water-repellent finishing agent system by using ethyl 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 formation 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 later high-temperature processing.

[0009] Preferably, the functional silicone monomer is at least one of vinyltrimethoxysilane, γ-methacryloxypropyltris(trimethylsiloxy)silane and γ-glycidyloxypropyltrimethoxysilane.

[0010] By adopting the above technical solution, vinyltrimethoxysilane, tris(γ-aminopropyl)trimethoxysilane and γ-glycidoxypropyltrimethoxysilane 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 polyurethane leather.

[0011] 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.

[0012] By adopting the above technical solution, the use of a double-layer polyurethane surface layer can fill minor depressions and unevenness on the polyurethane leather surface, making the prepared polyurethane leather more flat and smooth after coating. The first polyurethane surface layer forms a base layer on the surface of the air cloth layer, filling the tiny pores and unevenness caused by the vehicle interior frame. The second polyurethane surface layer can form a more flat and delicate surface layer based on the first polyurethane surface layer, forming a strong protective layer on the surface of the air cloth layer, making the surface of the polyurethane leather more flat and smooth after coating. The use of a double polyurethane surface layer can also enhance the wear resistance, durability, and wrinkle resistance of the polyurethane leather, extending the service life of the polyurethane leather.

[0013] 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.

[0014] 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 crosslinking agent, and 25-40 parts of water.

[0015] 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 solution and includes the following specific steps:

[0016] On the corresponding sides of the two base fabrics, polyester fibers are connected between the two base fabrics by weft knitting to form an air fabric layer, which is then subjected to water-repellent finishing.

[0017] 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.

[0018] 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.

[0019] Preferably, the step-by-step temperature increase range is 135-145° C., and the drying time is 12-10 minutes.

[0020] 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 heated to react to form a water-repellent finishing agent;

[0021] Then mix the water-repellent finishing agent with water to form a water-repellent finishing liquid, immerse the air-through cloth in the water-repellent finishing liquid, take out the air-through cloth after two immersions and two rollings, and perform pre-baking and baking in sequence to complete the water-repellent finishing of the air-through cloth.

[0022] By adopting the above technical solution, 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 automotive interiors.

[0023] In summary, this application has the following beneficial effects:

[0024] 1. This application utilizes the air structure of the air layer to achieve a 3D spatial effect, absorbing the flatness caused by the bottom of the vehicle interior frame. This ensures that the polyurethane leather achieves the required flatness and smoothness during wrapping, improving the flatness and comfort of polyurethane leather used in vehicle interiors. Furthermore, the air layer is treated with a water-repellent finish to reduce liquid corrosion on the polyurethane leather, and mitigate deformation and fading caused by humid environments.

[0025] 2. In this application, under the synergistic effect of various components, a silicone-containing acrylic water-repellent finishing agent with a stable core-shell structure is formed, which can firmly bond 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

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

[0027] The initiator is a conventional initiator for acrylate polymerization reaction, and in this embodiment, it is potassium persulfate.

[0028] The water-repellent crosslinking agent is glycidyl methacrylate.

[0029] The emulsifier is alkylphenol polyoxyethylene ether.

[0030] The polyester polyol was selected from BASF 100C-A.

[0031] The isocyanate prepolymer was selected from BASF 100C-B.

[0032] The accelerator is stannous 2-ethylhexanoate.

[0033] BYK9565 is selected as the leveling agent.

[0034] Sodium ammonium phosphate is selected as the flame retardant.

[0035] For semi-bright matte surface treatment agent, choose Degussa model TS-100.

[0036] Degussa OK-412 was selected as the matte surface treatment agent.

[0037] For the anti-wear agent, choose DOW-FBL-3289.

[0038] The defoamer selected is BYK-054.

[0039] The crosslinker selected was Stahl XR-5580.

[0040] The color paste is aniline black.

[0041] BASF Luwax AF31 was selected as the polyurethane resin.

[0042] Preparation Example 1

[0043] The water-repellent finish includes the following raw materials 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 crosslinker, and 2 kg of emulsifier. The functional silicone monomer is γ-methacryloyloxypropyl tris(trimethylsiloxy)silane.

[0044] The preparation method of the water-repellent finishing agent comprises the following specific steps:

[0045] S1: Methyl methacrylate, acrylic acid, a crosslinker, half the mass of an emulsifier, and half the mass of an initiator are mixed to form a mixed solution A. The mixed solution A is then 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.

[0046] S2: Dodecafluoroheptyl methacrylate, vinyl silicone oil, functional silicone monomer, remaining emulsifier and remaining initiator were 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 was mixed with water in a mass ratio of water to mixed solution B of 4:1 to form a pre-emulsion B.

[0047] S3: Then heat half the mass of pre-emulsion A to 65°C for reaction. After the reaction system turns blue and stabilizes, add the remaining pre-emulsion A, 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.

[0048] Preparation Example 2

[0049] 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.

[0050] Preparation Example 3

[0051] 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.

[0052] Preparation Example 4

[0053] Preparation Example 4 differs from Preparation Example 1 in that the functional organosilicon monomer in the water repellent finish raw material is vinyl trimethoxysilane.

[0054] Preparation Example 5

[0055] Preparation Example 5 differs from Preparation Example 1 in that the functional organosilicon monomer in the water repellent finish raw material is γ-glycidoxypropyl trimethoxysilane.

[0056] Preparation Example 6

[0057] Preparation Example 6 differs from Preparation Example 1 in that no functional organosilicon monomer is used in the water repellent finish raw material.

[0058] Preparation Example 7

[0059] Preparation Example 7 differs from Preparation Example 1 in that no functional organosilicon monomer and vinyl silicone oil are used in the water repellent finish raw material.

[0060] A method for preparing a water repellent finish, comprising the following specific steps:

[0061] 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, then the mixed solution is mixed with water, the mass ratio of water to the mixed solution is 4:1, stirring at a speed of 500 r / min for 0.5 h to form a pre-emulsion, then half the mass of the pre-emulsion is heated to 65°C for reaction, after the reaction system turns blue and stabilizes, the remaining pre-emulsion is added, and the reaction is maintained for 1 h, then the temperature is lowered to 40°C, the product is discharged and filtered to obtain the water repellent finish.

[0062] Preparation Example 8

[0063] Preparation Example 8 differs from Preparation Example 1 in that the water repellent finish raw material further includes 8 kg of tetraethyl orthosilicate and 0.4 kg of ammonia.

[0064] A method for preparing a water repellent finish, comprising the following specific steps:

[0065] 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, then the mixed solution A is mixed with water, the mass ratio of water to the mixed solution A is 4:1, stirring at a speed of 500 r / min for 0.5 h to form a pre-emulsion A, then tetraethyl orthosilicate is added dropwise to the pre-emulsion A, then ammonia is added, and the temperature is raised to 35°C for reaction for 6 h to obtain a composite solution A.

[0066] S2: Dodecafluoroheptyl methacrylate, vinyl silicone oil, functional silicone monomer, remaining emulsifier and remaining initiator were 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 was mixed with water in a mass ratio of water to mixed solution B of 4:1 to form a pre-emulsion B.

[0067] S3: Then heat half the mass of composite liquid A to 65°C for reaction. After the reaction system turns blue and stabilizes, add the remaining composite liquid A, then add 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.

[0068] Preparation Example 9

[0069] 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 materials is 5 kg, and the amount of ammonia water used is 0.3 kg.

[0070] Preparation Example 10

[0071] 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 materials is 10 kg, and the amount of ammonia water used is 0.5 kg.

[0072] Preparation Example 11

[0073] The difference between Preparation Example 11 and Preparation Example 8 is that no functional silicone monomer is used in the raw materials of the water-repellent finishing agent. Example Example

[0074] This embodiment provides an air layer polyurethane leather for high-flatness covering, 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 is derived from Preparation Example 1.

[0075] The bonding 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; solvent-free adhesive A is polyester polyol, and solvent-free adhesive B is isocyanate prepolymer.

[0076] 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.

[0077] 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-feeling and 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.

[0078] The preparation method of air layer polyurethane leather for high flatness coating comprises the following specific steps:

[0079] S1: The polyester fibers are connected to the middle of the two base fabrics by weft knitting on the corresponding sides of the two base fabrics, forming a space structure with a width of 0.1-1mm between the two base fabrics, and the weight is 250g / m 2 The air cloth layer is prepared, and then the water-repellent finishing agent is 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, and 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.

[0080] 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 temperature is increased in a step-by-step manner, the temperatures are 70 / 80 / 100 / 110 / 125 / 125℃, and the drying time is 4 minutes in total to obtain the polyurethane second surface layer; then apply the same weight portion of the polyurethane surface layer mixture on the surface of the polyurethane first 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 temperature is increased in a step-by-step manner, the temperatures are 70 / 80 / 100 / 110 / 125 / 125℃, and the drying time is 4 minutes in total to obtain the first polyurethane surface layer, that is, the polyurethane composite film layer.

[0081] 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, controlling the coating thickness to 0.25±0.01mm, and the vehicle speed to (10±1)m / min. Heat and dry, and use the oven to increase the temperature in a step-by-step manner, the temperature is 100 / 100 / 100 / 110 / 125 / 125℃, and bake for 2min. The adhesive layer is semi-dry, and then the air cloth layer is attached and dried. 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℃, and the drying time is 12min. Then separate the release paper to form a polyurethane leather semi-finished product.

[0082] S4: Mix a semi-bright matte surface treatment agent, a matte surface treatment agent, a hand-feel and wear-resistant agent, a defoaming agent, a leveling agent, a 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°C, respectively. Bake for 2 minutes, and curl after drying to obtain an air layer polyurethane leather for high-flatness coating. Example

[0083] The difference between Example 2 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 95 kg, the amount of solvent-free adhesive B used is 48 kg, the amount of accelerator used is 0.04 kg, the amount of curing agent used is 0.18 kg, the amount of leveling agent used is 0.15 kg, and the amount of flame retardant used is 35 kg. Example

[0084] 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 105 kg, the amount of solvent-free adhesive B used is 70 kg, the amount of accelerator used is 0.06 kg, the amount of curing agent used is 0.3 kg, the amount of leveling agent used is 0.25 kg, and the amount of flame retardant used is 50 kg. Example

[0085] The difference between Example 4 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 95 kg, the amount of N,N-dimethylformamide used is 60 kg, the amount of ethyl acetate used is 10 kg, and the amount of color paste used is 19 kg. Example

[0086] 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 105 kg, the amount of N,N-dimethylformamide used is 65 kg, the amount of ethyl acetate used is 15 kg, and the amount of color paste used is 25 kg. Example

[0087] The difference between Example 6 and Example 1 is that the amount of semi-bright matte surface treatment agent used in the raw materials of the coating layer of the air layer polyurethane leather for high flatness coating is 40 kg, the amount of matte surface treatment agent used is 60 kg, the amount of hand feel and wear-resistant agent used is 8 kg, the amount of defoaming agent used is 0.3 kg, the amount of leveling agent used is 1 kg, the amount of cross-linking agent used is 5 kg, and the amount of water used is 25 kg. Example

[0088] The difference between Example 7 and Example 1 is that the amount of semi-bright matte surface treatment agent used in the raw materials of the coating layer of the air layer polyurethane leather for high flatness coating is 60 kg, the amount of matte surface treatment agent used is 45 kg, the amount of hand feel and wear-resistant agent used is 16 kg, the amount of defoaming agent used is 0.2 kg, the amount of leveling agent used is 8 kg, the amount of cross-linking agent used is 7 kg, and the amount of water used is 40 kg. Example

[0089] 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 is derived from Preparation Example 2. Example

[0090] 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 is derived from Preparation Example 3. Example

[0091] 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 is derived from Preparation Example 4. Example

[0092] 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 is derived from Preparation Example 5. Example

[0093] 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 is derived from Preparation Example 6. Example

[0094] Example 13 differs from Example 1 in that the water repellent finish used for the air cloth layer in the high flatness air-layered polyurethane leather is derived from Preparation Example 7. Example

[0095] Example 14 differs from Example 1 in that the water repellent finish used for the air cloth layer in the high flatness air-layered polyurethane leather is derived from Preparation Example 8. Example

[0096] Example 15 differs from Example 1 in that the water repellent finish used for the air cloth layer in the high flatness air-layered polyurethane leather is derived from Preparation Example 9. Example

[0097] Example 16 differs from Example 1 in that the water repellent finish used for the air cloth layer in the high flatness air-layered polyurethane leather is derived from Preparation Example 10. Example

[0098] Example 17 differs from Example 1 in that the water repellent finish used for the air cloth layer in the high flatness air-layered polyurethane leather is derived from Preparation Example 11.

[0099] Comparative Example 1

[0100] Comparative Example 1 differs from Example 1 in that a single layer of nonwoven fabric is used instead of an air cloth layer in the high flatness air-layered polyurethane leather.

[0101] Comparative Example 2

[0102] Comparative Example 2 differs from Example 1 in that the air cloth layer in the high flatness air-layered polyurethane leather is not treated with a water repellent.

[0103] The high flatness air-layered polyurethane leather provided by Examples 1-17 and Comparative Examples 1-2 of the present application was subjected to the following performance tests, and the specific test results are shown in Table 1.

[0104] I. Water repellency

[0105] The water repellency of the polyurethane leather prepared in the present application was tested in accordance with the standard of GBT 4745-2012 "Determination and Evaluation of Water Resistance of Textiles - Water Drop Method".

[0106] II. Peel strength

[0107] The peel strength between the polyurethane leather prepared in the present application and the automobile spray adhesive covered portion was tested in accordance with the standard of GBT 8808-1988 "Peel Test Method for Soft Composite Plastic Materials", using B method sample size.

[0108] III. Wrapping effect

[0109] The polyurethane leather spray adhesive prepared in this application was coated on the skeleton of an automobile part, and the coating effect and flatness of the polyurethane leather surface were observed.

[0110] Table 1: Performance test data table

[0111] Example Water repellency grade (level) Peeling 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 / Example 11 4-5 1090 Smooth surface Example 12 4 1070 Smooth surface Example 13 3-4 1023 Smooth surface Example 14 5 1167 Smooth surface Example 15 5 1160 Smooth surface Example 16 5 1165 Smooth surface Example 17 4 1095 Smooth surface Comparative Example 1 2 856 Rough surface Comparative Example 2 1 915 Rough surface

[0112] It can be seen from the performance test results that the polyurethane leather prepared in this application can maintain a smooth and flat 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 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.

[0113] 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 repellency level of the prepared polyurethane leather is significantly reduced.

[0114] 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.

[0115] Comparison between Example 17 and Example 14 shows that Example 14 does not use a functional silicone monomer, possibly because the bonding force between silica and the air cloth layer is reduced, thereby resulting in a lower water repellency level of the polyurethane leather.

[0116] Comparing Comparative Examples 1 and 2 with Example 1, it can be seen that in Comparative Example 1, using a traditional nonwoven fabric instead of an air-seal fabric layer, the unevenness of the glue on the frame resulted in a noticeable uneven surface of the polyurethane leather coating when spray-coating the automotive part. This also reduced the peel strength between the polyurethane leather and the frame, which in turn easily caused the polyurethane leather to fall off and reduced the comfort of the polyurethane leather coating. In Comparative Example 2, the air-seal fabric layer was not treated with a water-repellent finish, resulting in reduced peel strength between the polyurethane leather and the automotive part, which in turn caused the polyurethane leather to easily deform and fall off due to moisture.

[0117] 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 non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

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 coating 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 cloth layer is treated with a water-repellent finishing agent. The water-repellent finishing agent comprises the following raw materials in parts by weight: 20-30 parts of dodecafluoroheptyl methacrylate, 30 parts of methyl methacrylate, and 10 parts of methyl methacrylate. -40 parts, acrylic acid 20-30 parts, vinyl silicone oil 10-15 parts, functional silicone monomer 15-18 parts, initiator 0.8-1 part, water-repellent crosslinking agent 1-3 parts, emulsifier 1-3 parts, ethyl orthosilicate 5-10 parts, ammonia water 0.3-0.5 parts; the functional silicone monomer is at least one of vinyl trimethoxysilane, γ-methacryloxypropyl tris(trimethylsiloxy)silane and γ-glycidyloxypropyl trimethoxysilane, and the water-repellent crosslinking agent is glycidyl methacrylate; The preparation method of the water-repellent finishing agent comprises the following specific steps: S1: Methyl methacrylate, acrylic acid, a water-repellent 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 solution A, and then ethyl orthosilicate is added dropwise to the pre-emulsion solution A, and then ammonia water is added, and the mixture is heated to 35°C for reaction for 6 h to obtain a composite solution A; S2: dodecafluoroheptyl methacrylate, vinyl silicone oil, functional silicone monomer, remaining emulsifier and remaining initiator were 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 was mixed with water in a mass ratio of water to mixed solution B of 4:1 to form a pre-emulsion solution B; S3: Then heat half the mass of composite liquid A to 65°C for reaction. After the reaction system turns blue and stabilizes, add the remaining composite liquid A, then add 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.

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, 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, 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.

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 finishing layer comprises the following raw materials in parts by weight: 40-60 parts of a semi-bright matte surface treatment agent, 45-60 parts of a matte surface treatment agent, 8-16 parts of a hand-feeling and wear-resistant agent, 0.2-0.3 parts of a defoaming agent, 0.8-1 parts of a leveling agent, 5-7 parts of a cross-linking agent, and 25-40 parts of water; the semi-bright matte surface treatment agent is Degussa model TS-100.

5. A method for preparing the high-flatness air layer polyurethane leather for coating according to any one of claims 1 to 4, characterized in that: The specific steps include: On the corresponding sides of the two base fabrics, polyester fibers are connected between the two base fabrics by weft knitting to form an air fabric layer, which is then 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.

6. The method for preparing the air layer polyurethane leather for high flatness coating according to claim 5, characterized in that: The step-by-step temperature increase 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: The water-repellent finishing agent is mixed with water to form a water-repellent finishing liquid. The air-cloth is immersed in the water-repellent finishing liquid. After two immersions and two rollings, the air-cloth is taken out and pre-baked and baked in sequence to complete the water-repellent finishing of the air-cloth layer.