A deep-sewing coated polyurethane seat leather and preparation method thereof

Abstract

The present application relates to the field of artificial leather, and specifically discloses a deep-sewn and coated polyurethane seat leather and a preparation method thereof. A deep-sewn and coated polyurethane seat leather comprises polyurethane leather and a reinforcing cloth, wherein the polyurethane leather and the reinforcing cloth are bonded with glue, and the polyurethane leather comprises a surface layer, a solvent-free adhesive layer, a base cloth and a finishing layer; the surface layer and the base cloth are bonded with a solvent-free polyurethane adhesive, and the glue comprises polyurethane glue. A deep-sewn and coated polyurethane seat leather prepared by the present application uses polyurethane glue to bond and adhere the reinforcing cloth to the polyurethane leather, and the polyurethane leather is compounded and reinforced, thereby improving the stiffness of the polyurethane leather, reducing the excessive stretching of the polyurethane leather, and solving the wrinkle phenomenon caused by the deep sewing and coating of the polyurethane seat leather.

Description

Technical Field

[0001] The present application relates to the field of artificial leather, and more specifically, to a deep-sewn coated polyurethane seat leather and a preparation method thereof. Background Art

[0002] Artificial leather is a plastic product that looks and feels like leather and can be used instead of leather. It is usually made of fabric as the base, coated with synthetic resin and various plastics. There are two main types: PVC artificial leather and polyurethane synthetic leather. PVC artificial leather is made by adding plasticizers and other additives to the base material by calendering or compounding. The advantages are low price, rich colors and various patterns. The disadvantage is that it is easy to harden and become brittle.

[0003] Polyurethane synthetic leather is a material used to replace PVC, but its price is higher than PVC. In terms of chemical structure, polyurethane synthetic leather is closer to leather, feels comfortable, and can be soft without adding plasticizers. It also has good heat and low temperature resistance and will not become hard or brittle. Polyurethane leather has been widely used in automotive interiors such as seats, door panels, dashboards, gear shifts, C-pillars, etc. Performance design should be carried out according to the interior requirements of different parts.

[0004] However, faced with the increasingly diverse car seat sewing styles on the market, the sewing styles are also different, especially the deep sewing styles involving deep concave and convex designs. Due to its softness, polyurethane leather has relatively poor support in the deep sewing covering area, which easily causes wrinkles in the sewing area. Summary of the invention

[0005] In order to improve the problem of wrinkles easily generated at the sewing parts of polyurethane leather, the present application provides a deep-sewing coated polyurethane seat leather.

[0006] In the first aspect, the present application provides a deep-sewn and coated polyurethane seat leather, which adopts the following technical scheme: a deep-sewn and coated polyurethane seat leather, comprising polyurethane leather and a reinforcing cloth, the polyurethane leather comprising a surface layer, a solvent-free adhesive layer, a base cloth and a finishing layer, the surface layer being arranged between the base cloth and the finishing layer, the reinforcing leather being arranged on the side of the base cloth away from the surface layer, the polyurethane leather and the reinforcing cloth being bonded by glue, the surface layer and the base cloth being bonded by a solvent-free adhesive layer, the solvent-free adhesive layer comprising a solvent-free polyurethane adhesive; the glue raw material comprises polyurethane glue, and the surface layer comprises the following raw materials in parts by weight: 95-105 parts of polyurethane resin, 55-75 parts of N,N-dimethylformamide, and 15-25 parts of ethyl acetate.

[0007] By adopting the above technical solution, the reinforcing cloth and the polyurethane leather are bonded and compounded by polyurethane glue, which can well reinforce the polyurethane leather, improve the stiffness of the polyurethane seat leather, and reduce the excessive stretching of the polyurethane seat leather, and reduce the wrinkle problem caused by the sewing and covering of the polyurethane seat leather. The surface layer made by the polyurethane resin system has excellent air permeability and flexibility, better stability, and improves the comfort of the polyurethane seat leather. The solvent-free polyurethane adhesive can better combine with the polyurethane resin and polyurethane glue, improve the bonding strength between the surface layer and the base fabric, and further improve the stiffness of the polyurethane seat leather.

[0008] Preferably, the reinforcing fabric is a non-woven fabric.

[0009] By adopting the above technical solution, the non-woven fabric can reduce the excessive stretching of the polyurethane leather, and at the same time can strengthen the polyurethane leather, thereby improving the stiffness of the polyurethane seat leather.

[0010] Preferably, the solvent-free polyurethane adhesive comprises the following raw materials in parts by weight: 95-105 parts of solvent-free adhesive A material, 105-115 parts of solvent-free adhesive B material, 0.03-0.08 parts of accelerator, 0.3-9 parts of curing agent, 0.25-0.55 parts of leveling agent, and 35-55 parts of flame retardant; the solvent-free adhesive A material is polyester polyol, and the solvent-free adhesive B material is isocyanate.

[0011] By adopting the above technical scheme, the prepared solvent-free polyurethane adhesive reduces the pollution problems of solvent residue and migration, saves energy consumption, and is safer to operate. At the same time, polyester polyols and isocyanates can better combine with the surface layer, strengthen the combination of the surface layer and the base fabric, thereby strengthening the polyurethane seat leather and further improving the stiffness of the polyurethane seat leather.

[0012] Preferably, the finishing layer comprises the following raw materials in parts by weight: 50-90 parts of matting agent, 10-50 parts of brightener, 5-8 parts of crosslinking agent, 3-6 parts of wear-resistant agent, 0.5-2 parts of leveling agent, 0.1-0.5 parts of defoaming agent, 0.1-3 parts of thickener, and 10-40 parts of water.

[0013] By adopting the above technical solution, the texture and gloss of the polyurethane seat leather are improved, and the wear resistance and scratch resistance of the polyurethane seat leather are improved.

[0014] Preferably, the glue raw material includes 40-60 parts of polyurethane glue, 5-12 parts of polytetrafluoroethylene, 0.5-1 part of graphene oxide, and 1-3 parts of silane coupling agent.

[0015] By adopting the above technical scheme, polytetrafluoroethylene can improve the water resistance and high temperature resistance of polyurethane glue, improve the stability of polyurethane glue, reduce the phenomenon of easy hydrolysis and high-temperature aging of polyurethane glue, thereby enhancing the bonding force between polyurethane leather and reinforcing cloth, and further improving the strength and stiffness of polyurethane seat leather. Graphene oxide combines with polytetrafluoroethylene through intermolecular forces, thereby improving the strength of polyurethane glue, thereby improving the strength and stiffness of polyurethane seat leather, and further reducing the problem of wrinkles caused by excessive stretching and sewing and covering of polyurethane seat leather.

[0016] On the one hand, the silane coupling agent can react with the hydroxyl groups on graphene oxide. On the other hand, the silane coupling agent can bind to the polytetrafluoroethylene molecular chain through the van der Waals force between polytetrafluoroethylene molecules, thereby increasing the intermolecular force between graphene oxide and polytetrafluoroethylene, thereby improving the strength, water resistance and high temperature resistance of the polyurethane glue, improving the stability of the polyurethane glue, further improving the strength and stiffness of the polyurethane seat leather, and reducing the wrinkle problem caused by excessive stretching and deep sewing and covering of the polyurethane seat leather. At the same time, the silane coupling agent molecules bind to the hydroxyl groups of the polyurethane glue, improving the binding of the polyurethane glue with graphene oxide and polytetrafluoroethylene, thereby further improving the water resistance and strength of the polyurethane glue, improving the stability of the polyurethane glue, and further improving the strength and stiffness of the polyurethane seat leather.

[0017] At the same time, the oxygen-containing functional groups of graphene oxide are adsorbed on the active sites of the reinforcing cloth, strengthening the bonding between the polyurethane leather and the reinforcing cloth, thereby further improving the stiffness of the polyurethane seat leather and reducing the wrinkle problem caused by excessive stretching and deep sewing and wrapping of the polyurethane seat leather.

[0018] Preferably, the raw materials of the polyurethane seat leather include 2-hydroxysuccinic acid and sodium hypophosphite, and the 2-hydroxysuccinic acid and sodium hypophosphite are used to modify non-woven fabrics.

[0019] By adopting the above technical solution, 2-hydroxysuccinic acid can be grafted with non-woven fabrics under the catalytic action of sodium hypophosphite, thereby improving the wrinkle resistance and deformation recovery ability of the non-woven fabrics, thereby improving the stiffness of the polyurethane seat leather and reducing the wrinkle problem of the polyurethane seat leather. At the same time, the hydroxyl group of 2-hydroxysuccinic acid can also combine with the -NCO group of the polyurethane glue, thereby increasing the interaction between the polyurethane glue and the non-woven fabric, promoting the combination of the polyurethane leather and the non-woven fabric, thereby strengthening the compounding of the polyurethane seat leather and reducing the wrinkle problem caused by deep sewing of the polyurethane seat leather.

[0020] Preferably, the modification method of the non-woven fabric comprises the following steps: pre-mixing 2-hydroxysuccinic acid, sodium hypophosphite and water to form an impregnation solution, then immersing the non-woven fabric in the impregnation solution, drying, and then calcining at 160-170°C for 5-7 minutes to obtain a modified non-woven fabric; the mass ratio of water, 2-hydroxysuccinic acid and sodium hypophosphite is 100:5-8:1-3.

[0021] By adopting the above technical solution, the non-woven fabric is modified by 2-hydroxysuccinic acid under high temperature roasting, thereby improving the wrinkle resistance and deformation recovery ability of the non-woven fabric, thereby improving the stiffness of the polyurethane seat leather and reducing the wrinkle problem of the polyurethane seat leather. At the same time, it also promotes the combination of 2-hydroxysuccinic acid and polyurethane adhesive molecules, thereby enhancing the bonding force between the polyurethane leather and the non-woven fabric, reducing the wrinkle problem caused by excessive stretching of the polyurethane seat leather, further improving the stiffness and rigidity of the polyurethane seat leather, and reducing the wrinkle problem caused by deep sewing of the polyurethane seat leather.

[0022] In a second aspect, the present application provides a method for preparing a deep-sewing coated polyurethane seat leather, which adopts the following technical solution:

[0023] A method for preparing a deep-sewing coated polyurethane seat leather comprises the following steps:

[0024] The polyurethane resin, N,N-dimethylformamide, ethyl acetate and color paste are mixed and coated on the release paper, and heated and dried to obtain a surface layer;

[0025] The solvent-free polyurethane adhesive is coated on the surface layer to form a solvent-free adhesive layer, and the base fabric is laminated after heating, and then the release paper is separated by drying to obtain a polyurethane leather primary product;

[0026] The matting agent, brightening agent, cross-linking agent, wear-resistant agent, leveling agent, defoaming agent, thickener and water are mixed, and then coated on the side of the polyurethane leather product away from the base fabric, and heated and dried to form a coating layer, and finally the polyurethane leather is obtained;

[0027] The glue is applied to the side of the polyurethane leather close to the base fabric, and then laminated with the reinforcing fabric, and heated and dried at 120°C-130°C to obtain the deep-sewing coated polyurethane seat leather.

[0028] By adopting the above technical solution, the prepared polyurethane seat leather has excellent comfort and rigidity, and reduces the wrinkle problem caused by excessive stretching and deep sewing and covering of the polyurethane seat leather.

[0029] Preferably, the silane coupling agent and graphene oxide are mixed in advance to form a mixed liquid, and then polytetrafluoroethylene is added to the mixed liquid and ultrasonically dispersed to obtain a composite liquid; the composite liquid is then mixed and stirred with polyurethane glue to obtain a composite glue; the composite glue is then bonded to a reinforcing cloth on the side of the polyurethane leather away from the coating layer, and then heated and dried at 120°C-130°C to obtain a deep-sewing coated polyurethane seat leather.

[0030] By adopting the above technical solution, graphene oxide is combined with polytetrafluoroethylene and then combined with polyurethane glue through a silane coupling agent, which improves the stability and strength of the polyurethane glue, thereby enhancing the bonding strength between the polyurethane leather and the reinforcing cloth, further improving the strength and stiffness of the polyurethane seat leather, and reducing the wrinkle problem caused by excessive stretching and deep sewing and covering of the polyurethane seat leather.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. Since the present application uses polyurethane glue to bond the reinforcing cloth to the polyurethane leather, the polyurethane leather is compounded and reinforced, thereby improving the stiffness of the polyurethane leather, reducing excessive stretching of the polyurethane leather, and reducing the wrinkle problem caused by deep sewing and covering of the polyurethane seat leather.

[0033] 2. In the present application, polytetrafluoroethylene and graphene oxide are preferably added to the polyurethane adhesive system, which improves the stability and strength of the polyurethane adhesive, further enhances the bonding force between the polyurethane leather and the reinforcing cloth, thereby improving the strength and stiffness of the polyurethane seat leather.

[0034] 3. The method of the present application improves the wrinkle resistance and deformation recovery ability of the non-woven fabric by pre-treating the non-woven fabric with 2-hydroxysuccinic acid, thereby improving the stiffness of the polyurethane seat leather and reducing the wrinkle problem of the polyurethane seat leather. At the same time, the combination of 2-hydroxysuccinic acid and polyurethane adhesive molecules enhances the bonding force between the polyurethane leather and the non-woven fabric, further reducing the wrinkle problem caused by deep sewing and covering of the polyurethane seat leather. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] In this specific embodiment, without other special circumstances, the components used are as follows:

[0037] The base fabric is SX57S from Jiangsu Songbai Textile Co., Ltd.

[0038] The color paste is RS-334 brown-red from Shanghai Riduo Polymer Materials Co., Ltd.

[0039] The polyurethane glue is a two-component polyurethane glue.

[0040] Polyester polyols are polyester diols.

[0041] The leveling agent is Levelol W-469.

[0042] The accelerator was purchased from Evonik Chemical Accelerator DS1300.

[0043] The curing agent was purchased from Shandong Dingke New Materials Co., Ltd. DK-SH1001.

[0044] The flame retardant is HF-FR polyurethane flame retardant.

[0045] The matting agent is HT3907.

[0046] The brightener is L-5521.

[0047] The cross-linking agent selected was aziridine cross-linking agent C9.

[0048] The anti-wear agent is LB-9735.

[0049] The defoamer selected is BYK-A535.

[0050] The thickener is HEC cellulose.

[0051] The weight of non-woven fabric is 30-50g / m 2 Commercially available non-woven fabrics.

[0052] Preparation example of composite glue

[0053] Preparation Example 1

[0054] The composite glue includes the following raw materials by weight: 50 kg of polyurethane glue, 8 kg of polytetrafluoroethylene, 0.75 kg of graphene oxide, and 2 kg of silane coupling agent. The silane coupling agent is γ-aminopropyltriethoxysilane.

[0055] The preparation method of the composite glue comprises the following steps:

[0056] The silane coupling agent and graphene oxide are mixed to form a mixed liquid, and polytetrafluoroethylene is added to the mixed liquid, and ultrasonic dispersion is performed for 15 minutes to obtain a composite liquid; the composite liquid is then mixed with polyurethane glue, and stirred at a speed of 300 r / min for 25 minutes to obtain a composite glue.

[0057] Preparation Example 2-3

[0058] The difference between Preparation Example 2-3 and Preparation Example 1 is that the contents of the components in the composite glue raw material are different, as shown in Table 1.

[0059] Table 1: Component contents of preparation examples 1-3

[0060]

[0061] Preparation Example 4

[0062] The difference between Preparation Example 4 and Preparation Example 1 is that the amount of polytetrafluoroethylene used in the composite glue raw material is 16 kg.

[0063] Preparation Example 5

[0064] The difference between Preparation Example 5 and Preparation Example 1 is that the amount of graphene oxide used in the composite glue raw material is 2 kg.

[0065] Preparation Example 6

[0066] The difference between Preparation Example 6 and Preparation Example 1 is that no silane coupling agent is used in the composite glue raw material.

[0067] The preparation method of the composite glue comprises the following steps:

[0068] Graphene oxide was mixed with polytetrafluoroethylene, and ultrasonically dispersed for 15 minutes to obtain a mixture. The mixture was then mixed with polyurethane glue, and stirred at a speed of 300 r / min for 25 minutes to obtain a composite glue.

[0069] Preparation Example 7

[0070] The difference between Preparation Example 7 and Preparation Example 1 is that the silane coupling agent in the composite glue raw material is replaced by an equal amount of 3-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0071] Preparation Example 8

[0072] The difference between Preparation Example 8 and Preparation Example 1 is that polytetrafluoroethylene is not used in the composite glue.

[0073] The preparation method of the composite glue comprises the following steps:

[0074] The silane coupling agent and graphene oxide are mixed to form a mixed liquid, and then the mixed liquid is mixed with polyurethane glue, and stirred at a speed of 300 r / min for 25 minutes to obtain a composite glue.

[0075] Preparation Example 9

[0076] The difference between Preparation Example 9 and Preparation Example 1 is that graphene oxide is not used in the composite glue.

[0077] The preparation method of the composite glue comprises the following steps:

[0078] The silane coupling agent and polytetrafluoroethylene were mixed, and ultrasonically dispersed for 15 minutes to obtain a mixed solution. The mixed solution was then mixed with polyurethane glue, and stirred at a speed of 300 r / min for 25 minutes to obtain a composite glue.

[0079] Preparation example of modified nonwoven fabric

[0080] Preparation Example 10

[0081] The modification method of non-woven fabric comprises the following steps: pre-mixing 2-hydroxysuccinic acid, sodium hypophosphite and water to form an impregnation solution, placing the non-woven fabric in the impregnation solution, impregnating at room temperature for 1 hour, drying at 80°C, then roasting at 170°C for 5 minutes, washing the non-woven fabric, and drying at 80°C to obtain a modified non-woven fabric. The mass ratio of water, 2-hydroxysuccinic acid and sodium hypophosphite is 100:7:2, and the non-woven fabric is a commercially available non-woven fabric.

[0082] Preparation Example 11

[0083] The difference between Preparation Example 11 and Preparation Example 10 is that the mass ratio of water, 2-hydroxysuccinic acid and sodium hypophosphite in the step of modifying the non-woven fabric is 100:5:1.

[0084] Preparation Example 12

[0085] The difference between Preparation Example 12 and Preparation Example 10 is that the mass ratio of water, 2-hydroxysuccinic acid and sodium hypophosphite in the step of modifying the non-woven fabric is 100:8:3.

[0086] Preparation Example 13

[0087] The difference between Preparation Example 13 and Preparation Example 10 is that the mass ratio of water, 2-hydroxysuccinic acid and sodium hypophosphite in the step of modifying the non-woven fabric is 100:10:5.

[0088] Preparation Example 14

[0089] The difference between Preparation Example 14 and Preparation Example 10 is that the 2-hydroxysuccinic acid in the step of modifying the non-woven fabric is replaced by an equal amount of oxalic acid.

[0090] Example of preparation of surface layer

[0091] Preparation Example 15

[0092] The surface layer comprises the following raw materials in parts by weight: 100 kg of polyurethane resin, 65 kg of N,N-dimethylformamide, 20 kg of ethyl acetate and 14 kg of color paste.

[0093] The method for preparing the surface layer comprises the following steps:

[0094] S1: Mixing polyurethane resin, N,N-dimethylformamide, ethyl acetate and color paste to form a polyurethane surface layer composite material, coating the polyurethane surface layer composite material on release paper, controlling the coating thickness to 0.20±0.01mm, heating and drying to obtain a surface layer semi-finished product;

[0095] S2: The polyurethane surface layer composite material is coated on the surface layer semi-finished product again, the coating thickness is controlled at 0.25±0.01mm, and the surface layer is finally obtained by heating and drying.

[0096] Preparation Examples 16-17

[0097] The difference between Preparation Example 16-17 and Preparation Example 15 is that the contents of the components in the surface layer raw materials are different, as shown in Table 2

[0098] Table 2: Component contents in Preparation Examples 15-17

[0099]

[0100] Preparation Example of Solvent-free Polyurethane Adhesive

[0101] Preparation Example 18

[0102] The solvent-free polyurethane adhesive comprises the following raw materials in parts by weight: 100 kg of solvent-free adhesive A material, 110 kg of solvent-free adhesive B material, 0.05 kg of accelerator, 4.5 kg of curing agent, 0.4 kg of leveling agent and 45 kg of flame retardant.

[0103] The preparation method of the solvent-free polyurethane adhesive comprises the following steps:

[0104] Solvent-free adhesive material A, solvent-free adhesive material B, accelerator, curing agent, leveling agent and flame retardant were mixed, and stirred at a speed of 500 r / min for 10 minutes to prepare a solvent-free polyurethane adhesive.

[0105] Preparation Examples 19-20

[0106] The difference between Preparation Examples 19-20 and Preparation Example 18 is that the contents of the components in the solvent-free polyurethane adhesive raw materials are different, as shown in Table 3.

[0107] Table 3: Component contents in Preparation Examples 18-20

[0108]

[0109] Preparation example of coating composite material

[0110] Preparation Example 21

[0111] The coating composite material includes the following raw materials in parts by weight: 70 kg of matting agent, 30 kg of brightening agent, 6.5 kg of cross-linking agent, 4.5 kg of wear-resistant agent, 1 kg of leveling agent, 0.3 kg of defoaming agent, 1 kg of thickener and 25 kg of water.

[0112] The preparation method of the coating composite material comprises the following steps:

[0113] The matting agent, brightening agent, cross-linking agent, wear-resistant agent, leveling agent, defoaming agent, thickening agent and water are mixed, and stirred at a speed of 500 r / min for 10 minutes to prepare a coating composite material.

[0114] Preparation Examples 22-23

[0115] The difference between Preparation Example 22-23 and Preparation Example 21 is that the contents of the components in the coating composite raw materials are different, as shown in Table 4 for details.

[0116] Table 4: Component contents in Preparation Examples 21-23

[0117]

[0118] Example

[0119] Example 1

[0120] The deep sewing and covering polyurethane seat leather comprises polyurethane leather and reinforcing cloth, wherein the polyurethane leather and the reinforcing cloth are bonded by glue, the polyurethane leather comprises a surface layer, a base cloth and a finishing layer, and the surface layer and the base cloth are bonded by a solvent-free polyurethane adhesive. The surface layer is prepared by Preparation Example 15, the solvent-free adhesive is prepared by Preparation Example 18, the glue is polyurethane glue, and the reinforcing cloth is a commercially available non-woven fabric.

[0121] A method for preparing deep-sewing coated polyurethane seat leather comprises the following steps:

[0122] S1: applying a solvent-free polyurethane adhesive on the surface layer to form a solvent-free adhesive layer with a coating thickness of 0.20±0.01 mm, heating, and when the adhesive is dried to half dry, laminating the base fabric, and then drying and separating the release paper to obtain a polyurethane leather product;

[0123] S4: applying the finishing composite material prepared in Preparation Example 21 on the side of the polyurethane leather product away from the base fabric, with a coating thickness of 0.20±0.01 mm, heating and drying to form a finishing layer, and finally obtaining polyurethane leather;

[0124] S5: Apply polyurethane glue to the side of the polyurethane leather close to the base fabric with a coating thickness of 0.20±0.01mm, and then laminate it with the reinforcing fabric. Heat and dry it at 125°C for 15s to obtain a deep-sewn and coated polyurethane seat leather.

[0125] Example 2

[0126] The difference between Example 2 and Example 1 is that the surface layer in the polyurethane seat leather raw material is prepared by Preparation Example 16, the solvent-free adhesive is prepared by Preparation Example 19, and the coating composite material is prepared by Preparation Example 22, wherein in step S5, the thickness of the polyurethane adhesive coating is 0.30±0.02 mm.

[0127] Example 3

[0128] The difference between Example 3 and Example 1 is that the surface layer in the polyurethane seat leather raw material is prepared by Preparation Example 17, the solvent-free adhesive is prepared by Preparation Example 20, and the coating composite material is prepared by Preparation Example 23, wherein in step S5, the thickness of the polyurethane adhesive coating is 0.40±0.02 mm.

[0129] Example 4

[0130] The difference between Example 4 and Example 1 is that the sources of the glue and the reinforcing cloth in the polyurethane seat leather raw materials are different, as shown in Table 5 for details.

[0131] Table 5: Component sources of Examples 4-18

[0132]

[0133]

[0134] Embodiment 19

[0135] The difference between Example 19 and Example 1 is that the reinforcing cloth in the polyurethane seat leather raw material is commercially available linen cloth.

[0136] Comparative Example

[0137] Comparative Example 1

[0138] The difference between Comparative Example 1 and Example 1 is that no reinforcing cloth and polyurethane glue are used in the polyurethane seat leather raw material.

[0139] A method for preparing deep-sewing coated polyurethane seat leather comprises the following steps:

[0140] S1: applying a solvent-free polyurethane adhesive on the surface layer to form a solvent-free adhesive layer with a coating thickness of 0.20±0.01 mm, heating, and when the adhesive is dried to half dry, laminating the base fabric, and then drying and separating the release paper to obtain a polyurethane leather product;

[0141] S4: Apply the coating composite material prepared in Preparation Example 21 on the side of the polyurethane leather product away from the base fabric, with a coating thickness of 0.20±0.01 mm, heat and dry to form a coating layer, and finally obtain the polyurethane seat leather.

[0142] Comparative Example 2

[0143] The difference between Comparative Example 2 and Example 1 is that the polyurethane glue in the polyurethane seat leather raw material is replaced by an equal amount of epoxy resin glue.

[0144] Performance Testing The following performance testing was performed on the polyurethane seat leathers provided in Examples 1-19 and Comparative Examples 1-2 of the present application. The test data results are shown in Table 6.

[0145] Detection Methods

[0146] 1. Rigidity and Softness

[0147] The Q / 320585RG 015-2021 "Deep Sewing Covered PU Seat Leather" test standard is adopted to test the stiffness and softness of polyurethane seat leather. Take 3 samples of 25mm×200mm in the longitudinal and transverse directions respectively, and place the sample on the horizontal platform indicated in the test standard with its short side aligned with the baseline of the ruler. Press it with a pressing plate of the same size as the sample, and slide it in the direction of the inclined surface at a speed of about 10mm / s. When one end of the sample touches the inclined surface, read the position of the other end with the ruler. The stiffness and softness are expressed as the displacement (mm) of the sample at the other end. Measure the front, back, left and right ends of the 3 samples in the longitudinal and transverse directions respectively, and take the average value.

[0148] 2. Tensile Strength

[0149] The test was carried out according to the standard GB / T1040.3-2006 "Determination of tensile properties of plastics", and three groups of samples were taken along the warp and weft directions. The sample size was 200mm×50mm, the standard length was 100mm, and the tensile speed was 200mm / min.

[0150] Table 6: Performance test data table

[0151]

[0152] It can be seen from Examples 1-3 that the polyurethane seat leather prepared in the present application has excellent stretchability and rigidity. The present application uses polyurethane glue to compositely reinforce the polyurethane leather and the reinforcing cloth, thereby ensuring the softness of the polyurethane leather while improving the stiffness of the polyurethane seat leather and reducing the phenomenon of excessive stretching and deep sewing and wrapping of the polyurethane seat leather to produce wrinkles. At the same time, by comparing the performance test results of Example 1 with those of Example 19, the non-woven fabric has a better composite reinforcement effect on the polyurethane leather.

[0153] It can be seen from Examples 4-6 that adding graphene oxide, polytetrafluoroethylene and silane coupling agent to the polyurethane adhesive system improves the strength and stability of the polyurethane adhesive, further enhances the bonding force between the polyurethane adhesive and the polyurethane leather and the reinforcing cloth, thereby improving the strength of the polyurethane seat leather. Through the interaction between the silane coupling agent, graphene oxide, polytetrafluoroethylene and polyurethane adhesive, and the mutual combination of graphene oxide and the reinforcing cloth, the composite reinforcing force of the reinforcing cloth on the polyurethane leather is further enhanced, thereby improving the stiffness of the polyurethane seat leather and further reducing the problem of the polyurethane seat leather being prone to wrinkles. The amounts of graphene oxide, polytetrafluoroethylene and silane coupling agent used in Examples 4-6 are different. From the test results, it can be seen that Example 4 has the best performance.

[0154] In Example 7, an excessive amount of polytetrafluoroethylene is used, and in Example 8, an excessive amount of graphene oxide is used. The test results show that the performance of the polyurethane seat leather is reduced, indicating that controlling the amount of polytetrafluoroethylene and graphene oxide is also crucial to the performance of the polyurethane seat leather. In Example 9, no silane coupling agent is used, and the rigidity and strength of the polyurethane seat leather are reduced, indicating that the silane coupling agent, on the one hand, combines with polytetrafluoroethylene and graphene oxide, and is added to the polyurethane adhesive system to improve the strength of the polyurethane adhesive system. On the other hand, it also acts with the polyurethane adhesive molecules, thereby enhancing the bonding effect between the polyurethane adhesive and the polyurethane leather and the reinforcing cloth, further improving the stiffness of the polyurethane seat leather, and reducing the phenomenon that the polyurethane seat leather is prone to wrinkles. In Example 10, other types of silane coupling agents are used. The test results show that the silane coupling agent used in Example 4 has better performance and stronger bonding with each component. While Example 11 does not use polytetrafluoroethylene, and Example 12 does not use graphene oxide, the performance of the polyurethane seat leather is reduced, which further illustrates the reinforcing effect of polytetrafluoroethylene and graphene oxide on the polyurethane seat leather.

[0155] In Examples 13-15, different amounts of 2-hydroxysuccinic acid and sodium hypophosphite were used to modify the non-woven fabric, which improved the wrinkle resistance and deformation recovery ability of the non-woven fabric, thereby improving the stiffness of the polyurethane seat leather and reducing the wrinkle problem of the polyurethane seat leather. Among them, the amount of 2-hydroxysuccinic acid and sodium hypophosphite used in Example 13 was the best. However, in Example 16, excessive amounts of 2-hydroxysuccinic acid and sodium hypophosphite were used, and the performance of the polyurethane seat leather decreased, indicating that the amount of 2-hydroxysuccinic acid and sodium hypophosphite is also crucial to the performance of the polyurethane seat leather. In Example 17, other compounds were used instead of 2-hydroxysuccinic acid, and the performance of the polyurethane seat leather decreased, indicating that 2-hydroxysuccinic acid has a better modification effect on non-woven fabrics.

[0156] It can be seen from the performance test results of Example 18 that by adding graphene oxide, polytetrafluoroethylene and silane coupling agent to the polyurethane seat leather, and using 2-hydroxysuccinic acid and sodium hypophosphite to modify the non-woven fabric, under the mutual action of the components, the polyurethane seat leather prepared in this application has excellent rigidity and strength, and reduces the phenomenon of excessive stretching of the polyurethane seat leather and wrinkles caused by deep sewing and wrapping.

[0157] Compared with Example 1, in Comparative Example 1, no reinforcing cloth and polyurethane glue are used to reinforce the polyurethane leather. The test results show that the rigidity and strength of the polyurethane seat leather are affected, and it is easy to cause wrinkles during use, which further illustrates that the reinforcing effect of reinforcing cloth and polyurethane glue on polyurethane leather can reduce the wrinkles of polyurethane seat leather. In Comparative Example 2, other types of adhesives are used instead of polyurethane glue. The test results show that the performance of the polyurethane seat leather is slightly reduced, indicating that the polyurethane glue has a better combination with polyurethane leather and non-woven fabric.

[0158] 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 deep sewing coated polyurethane seat leather, characterized in that: The invention comprises polyurethane leather and a reinforcing cloth, wherein the polyurethane leather comprises a surface layer, a solvent-free adhesive layer, a base cloth and a finishing layer, wherein the surface layer is arranged between the base cloth and the finishing layer, and the reinforcing cloth is arranged on a side of the base cloth away from the surface layer, the polyurethane leather and the reinforcing cloth are bonded by glue, and the surface layer and the base cloth are bonded by a solvent-free adhesive layer, wherein the solvent-free adhesive layer comprises a solvent-free polyurethane adhesive; the raw materials of the glue comprise 40-60 parts of polyurethane glue, 5-12 parts of polytetrafluoroethylene, 0.5-1 part of graphene oxide, and 1-3 parts of a silane coupling agent, and the surface layer comprises the following raw materials in parts by weight: 95-105 parts of polyurethane resin, 55-75 parts of N,N-dimethylformamide, and 15-25 parts of ethyl acetate.

2. The deep-sewing covered polyurethane seat leather according to claim 1, characterized in that: The reinforcing fabric is non-woven fabric.

3. The deep-sewing covered polyurethane seat leather according to claim 1, characterized in that: The solvent-free polyurethane adhesive comprises the following raw materials in parts by weight: 95-105 parts of solvent-free adhesive material A, 105-115 parts of solvent-free adhesive material B, 0.03-0.08 parts of accelerator, 0.3-9 parts of curing agent, 0.25-0.55 parts of leveling agent, and 35-55 parts of flame retardant; the solvent-free adhesive material A is polyester polyol, and the solvent-free adhesive material B is isocyanate.

4. The deep-sewing covered polyurethane seat leather according to claim 2, characterized in that: The raw materials of the polyurethane seat leather also include 2-hydroxysuccinic acid and sodium hypophosphite, and the 2-hydroxysuccinic acid and sodium hypophosphite are used to modify non-woven fabrics.

5. The deep-sewing covered polyurethane seat leather according to claim 4, characterized in that: The modification method of the non-woven fabric comprises the following steps: pre-mixing 2-hydroxysuccinic acid, sodium hypophosphite and water to form an impregnation solution, then immersing the non-woven fabric in the impregnation solution, drying, and then roasting at 160-170° C. for 5-7 minutes to obtain a modified non-woven fabric; the mass ratio of the water, 2-hydroxysuccinic acid and sodium hypophosphite is 100:5-8:1-3.

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