Anti-cracking leather fabric and production process thereof

Abstract

The application relates to the technical field of leather materials, and discloses an anti-cracking leather fabric and a production process thereof, wherein the anti-cracking leather fabric comprises, from top to bottom, a surface leather layer, a middle foaming layer and a bottom base cloth layer; the surface leather layer comprises the following components in parts by weight: polyurethane resin 45-65 parts, dimethylformamide 40-50 parts, wood powder 20-30 parts, antioxidant 0.5-1.5 parts and plasticizer 1-3 parts; the middle foaming layer comprises the following components in parts by weight: water-based polyurethane resin 46-67 parts, polyetherimide 20-35 parts, glass fiber 1-2 parts, tackifier 4-14 parts and foaming agent 8-16 parts; and the tackifier comprises carboxymethylhydroxyethyl cellulose and carboxymethyl cellulose. Through the technical scheme, the problem of poor anti-cracking performance of the leather fabric in the related art is solved.

Description

Technical Field

[0001] This invention relates to the field of leather materials technology, specifically to a crack-resistant leather fabric and its manufacturing process. Background Technology

[0002] Leather is a classic clothing material, highly favored for its unique texture, natural grain, and luster. Leather fabrics typically possess good elasticity, durability, breathability, and sweat absorption, as well as good shape retention and formability, making them widely used in clothing and decorative applications such as furniture. Based on processing techniques and raw materials, leather fabrics can be divided into three main categories: natural leather, recycled leather, and synthetic leather.

[0003] Artificial leather is typically made from various polymers and is a material that mimics natural leather. Its relatively low cost compared to natural leather makes it more economical, giving it a significant advantage in large-scale production and widespread application. However, artificial leather also has some drawbacks. Besides lacking the texture and softness of natural leather, it is also prone to cracking, affecting its usability. Therefore, developing a crack-resistant leather fabric is of great importance. Summary of the Invention

[0004] This invention proposes a crack-resistant leather fabric and its production process, which solves the problem of poor crack resistance of leather fabrics in related technologies.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes an anti-cracking leather fabric, comprising a surface leather layer, an intermediate foam layer, and a bottom base fabric layer arranged sequentially from top to bottom. The surface leather layer comprises the following components in parts by weight: 45-65 parts polyurethane resin, 40-50 parts dimethylformamide, 20-30 parts wood flour, 0.5-1.5 parts antioxidant, and 1-3 parts plasticizer.

[0007] The intermediate foaming layer comprises the following components in parts by weight: 46-67 parts of waterborne polyurethane resin, 20-35 parts of polyetherimide, 1-2 parts of glass fiber, 4-14 parts of tackifier, and 8-16 parts of foaming agent.

[0008] The thickeners include carboxymethyl hydroxyethyl cellulose and carboxymethyl cellulose.

[0009] As a further technical solution, the weight ratio of the waterborne polyurethane resin to the tackifier is 8~11:1.

[0010] When the weight ratio of waterborne polyurethane resin to tackifier is 8~11:1, the crack resistance of leather fabric can be improved.

[0011] As a further technical solution, the weight ratio of carboxymethyl hydroxyethyl cellulose to carboxymethyl cellulose is 1~3:1.

[0012] When the weight ratio of carboxymethyl hydroxyethyl cellulose to carboxymethyl cellulose is 1~3:1, the crack resistance of leather fabric can be improved.

[0013] As a further technical solution, the wood flour is modified wood flour, which is obtained by modifying wood flour with diatomaceous earth and styrene-maleic anhydride copolymer.

[0014] As a further technical solution, the raw materials for the modified wood flour include wood flour, diatomaceous earth, and styrene-maleic anhydride copolymer.

[0015] By modifying wood flour with diatomaceous earth and styrene-maleic anhydride copolymer, the interfacial bonding force between wood flour and other components is improved. While filling the defects in the surface leather layer, diatomaceous earth can increase the internal structural porosity of the material and increase the air permeability of the leather fabric. Meanwhile, the styrene-maleic anhydride copolymer improves the dispersibility of wood flour and diatomaceous earth and can interact with the intermediate foaming layer, thereby improving the overall crack resistance of the leather fabric.

[0016] As a further technical solution, the weight ratio of the wood flour, diatomaceous earth and styrene-maleic anhydride copolymer is 7~11:0.5:0.5.

[0017] When the weight ratio of wood flour, diatomaceous earth, and styrene-maleic anhydride copolymer is 7~11:0.5:0.5, the crack resistance of leather fabric can be further improved.

[0018] As a further technical solution, the preparation method of the modified wood flour includes the following steps: dissolving the styrene-maleic anhydride copolymer in ethyl acetate to obtain a styrene-maleic anhydride copolymer solution, adding wood flour and diatomaceous earth to the styrene-maleic anhydride copolymer solution, stirring, concentrating, and obtaining modified wood flour.

[0019] As a further technical solution, the mass fraction of the styrene-maleic anhydride copolymer solution is 5%~10%.

[0020] As a further technical solution, the antioxidant is one or more of antioxidant 168, antioxidant 1010, and antioxidant 1076.

[0021] As a further technical solution, the plasticizer is one or both of dioctyl phthalate and dioctyl adipate.

[0022] As a further technical solution, the foaming agent is one or more of azobisisobutyronitrile, diisopropyl azodicarbonate, and diethyl azodicarbonate.

[0023] This invention also proposes a production process for the aforementioned crack-resistant leather fabric, comprising the following steps:

[0024] S1. The components in the surface leather layer are blended by weight and calendered to obtain the surface leather layer;

[0025] S2. After mixing and grinding the water-based polyurethane resin, polyetherimide, and glass fiber in the intermediate foaming layer, add a tackifier and a foaming agent to obtain a mixed slurry. Coat the mixed slurry on the lower surface of the surface leather layer and foam it to obtain the intermediate foaming layer.

[0026] S3. Bond the intermediate foam layer and the bottom base fabric layer to obtain the crack-resistant leather fabric.

[0027] As a further technical solution, in step S1, the temperature during blending is 130~140℃.

[0028] The working principle and beneficial effects of this invention are as follows:

[0029] In this invention, the intermediate foam layer comprises waterborne polyurethane resin and a tackifier, including carboxymethyl hydroxyethyl cellulose and carboxymethyl cellulose. The combined use of these three components increases the overall viscosity of the intermediate foam layer while improving the uniformity and density of the waterborne polyurethane resin film, thereby enhancing the crack resistance of the leather fabric. Furthermore, the addition of wood flour to the surface leather layer also improves the crack resistance of the leather fabric. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] In the following examples and comparative examples, the polyurethane resin is model S-395A; the wood flour is pine wood flour with a particle size of 325 mesh; the waterborne polyurethane resin is model RL8303; the polyetherimide is model HU1010; the glass fiber is model 988A; the ethylene-maleic anhydride copolymer is model AC 573P; the diatomaceous earth has a particle size of 400 mesh; and the bottom base fabric is non-woven fabric.

[0032] Example 1

[0033] A crack-resistant leather fabric includes a surface leather layer, an intermediate foam layer and a bottom base fabric layer arranged sequentially from top to bottom. The surface leather layer includes the following components in parts by weight: 45 parts polyurethane resin, 40 parts dimethylformamide, 20 parts wood flour, 0.5 parts antioxidant 1010 and 1 part dioctyl phthalate.

[0034] The intermediate foam layer comprises the following components in parts by weight: 46 parts waterborne polyurethane resin, 20 parts polyetherimide, 1 part glass fiber, 4 parts tackifier, and 8 parts diisopropyl azodicarbonate.

[0035] The thickener consists of 1 part carboxymethyl hydroxyethyl cellulose and 3 parts carboxymethyl cellulose;

[0036] Its production process includes the following steps:

[0037] S1. The components in the surface leather layer by weight are blended at 130°C and calendered to obtain the surface leather layer.

[0038] S2. After mixing and grinding the water-based polyurethane resin, polyetherimide, and glass fiber in the intermediate foaming layer, add tackifier and foaming agent to obtain a mixed slurry. Coat the mixed slurry on the lower surface of the surface leather layer and foam to obtain the intermediate foaming layer.

[0039] S3. Bond the middle foam layer and the bottom base fabric layer together to obtain crack-resistant leather fabric.

[0040] Example 2

[0041] A crack-resistant leather fabric includes a surface leather layer, an intermediate foam layer and a bottom base fabric layer arranged sequentially from top to bottom. The surface leather layer includes the following components in parts by weight: 55 parts polyurethane resin, 45 parts dimethylformamide, 24 parts wood flour, 1 part antioxidant 1010, and 2 parts dioctyl phthalate.

[0042] The intermediate foam layer comprises the following components in parts by weight: 62 parts waterborne polyurethane resin, 27 parts polyetherimide, 1.5 parts glass fiber, 10 parts tackifier, and 12 parts diisopropyl azodicarbonate.

[0043] The thickener consists of 4 parts carboxymethyl hydroxyethyl cellulose and 6 parts carboxymethyl cellulose;

[0044] Its production process includes the following steps:

[0045] S1. The components in the surface leather layer by weight are blended at 135°C and calendered to obtain the surface leather layer.

[0046] S2. After mixing and grinding the water-based polyurethane resin, polyetherimide, and glass fiber in the intermediate foaming layer, add tackifier and foaming agent to obtain a mixed slurry. Coat the mixed slurry on the lower surface of the surface leather layer and foam to obtain the intermediate foaming layer.

[0047] S3. Bond the middle foam layer and the bottom base fabric layer together to obtain crack-resistant leather fabric.

[0048] Example 3

[0049] A crack-resistant leather fabric includes a surface leather layer, an intermediate foam layer and a bottom base fabric layer arranged sequentially from top to bottom. The surface leather layer includes the following components in parts by weight: 65 parts polyurethane resin, 50 parts dimethylformamide, 30 parts wood flour, 1.5 parts antioxidant 1010 and 3 parts dioctyl phthalate.

[0050] The intermediate foam layer comprises the following components in parts by weight: 67 parts waterborne polyurethane resin, 35 parts polyetherimide, 2 parts glass fiber, 14 parts tackifier, and 16 parts diisopropyl azodicarbonate.

[0051] The thickener consists of 6 parts carboxymethyl hydroxyethyl cellulose and 8 parts carboxymethyl cellulose;

[0052] Its production process includes the following steps:

[0053] S1. The components in the surface leather layer by weight are blended at 140°C and calendered to obtain the surface leather layer.

[0054] S2. After mixing and grinding the water-based polyurethane resin, polyetherimide, and glass fiber in the intermediate foaming layer, add tackifier and foaming agent to obtain a mixed slurry. Coat the mixed slurry on the lower surface of the surface leather layer and foam to obtain the intermediate foaming layer.

[0055] S3. Bond the middle foam layer and the bottom base fabric layer together to obtain crack-resistant leather fabric.

[0056] Example 4

[0057] The only difference between this embodiment and Embodiment 2 is that the amount of waterborne polyurethane resin added to the intermediate foaming layer is 67 parts, and the amount of tackifier added is 5 parts, wherein the tackifier includes 2 parts of carboxymethyl hydroxyethyl cellulose and 3 parts of carboxymethyl cellulose.

[0058] Example 5

[0059] The only difference between this embodiment and Embodiment 2 is that the amount of waterborne polyurethane resin added to the intermediate foaming layer is 66 parts, and the amount of tackifier added is 6 parts, wherein the tackifier includes 2 parts of carboxymethyl hydroxyethyl cellulose and 4 parts of carboxymethyl cellulose.

[0060] Example 6

[0061] The only difference between this embodiment and Embodiment 2 is that the amount of waterborne polyurethane resin added to the intermediate foaming layer is 64 parts, and the amount of tackifier added is 8 parts, wherein the tackifier includes 3 parts of carboxymethyl hydroxyethyl cellulose and 5 parts of carboxymethyl cellulose.

[0062] Example 7

[0063] The only difference between this embodiment and Embodiment 6 is that the thickener includes 7 parts carboxymethyl hydroxyethyl cellulose and 1 part carboxymethyl cellulose.

[0064] Example 8

[0065] The only difference between this embodiment and Embodiment 6 is that the thickener includes 4 parts of carboxymethyl hydroxyethyl cellulose and 4 parts of carboxymethyl cellulose.

[0066] Example 9

[0067] The only difference between this embodiment and Embodiment 6 is that the thickener includes 6 parts of carboxymethyl hydroxyethyl cellulose and 2 parts of carboxymethyl cellulose.

[0068] Example 10

[0069] The only difference between this embodiment and Embodiment 9 is that the wood flour is modified wood flour, which is obtained by modifying wood flour with diatomaceous earth and styrene-maleic anhydride copolymer. The preparation method of modified wood flour includes the following steps: dissolving 2 parts of styrene-maleic anhydride copolymer in ethyl acetate to obtain a styrene-maleic anhydride copolymer solution with a mass fraction of 6%; adding 20 parts of wood flour and 2 parts of diatomaceous earth to the styrene-maleic anhydride copolymer solution with a mass fraction of 6%; stirring; concentrating; and obtaining modified wood flour.

[0070] Example 11

[0071] The only difference between this embodiment and Example 10 is that the modified wood flour is obtained by modifying 20 parts of wood flour with 1 part of diatomaceous earth and 3 parts of styrene-maleic anhydride copolymer.

[0072] Example 12

[0073] The only difference between this embodiment and Example 10 is that the modified wood flour is obtained by modifying 21 parts of wood flour with 1.5 parts of diatomaceous earth and 1.5 parts of styrene-maleic anhydride copolymer.

[0074] Example 13

[0075] The only difference between this embodiment and Example 10 is that the modified wood flour is obtained by modifying 22 parts of wood flour with 1 part of diatomaceous earth and 1 part of styrene-maleic anhydride copolymer.

[0076] Comparative Example 1

[0077] The only difference between this comparative example and Example 1 is that the tackifier consists of only 4 parts of carboxymethyl hydroxyethyl cellulose.

[0078] Comparative Example 2

[0079] The only difference between this comparative example and Example 1 is that the tackifier consists of only 4 parts of carboxymethyl cellulose.

[0080] Comparative Example 3

[0081] The only difference between this comparative example and Example 1 is that it does not include a thickener.

[0082] Comparative Example 4

[0083] The only difference between this comparative example and Example 1 is that it does not include wood flour.

[0084] The anti-cracking leather fabrics produced by the manufacturing processes of Examples 1-13 and Comparative Examples 1-4 were subjected to the following performance tests:

[0085] Folding fastness: The folding fastness of the leather fabric was tested according to QB / T 2714-2005 "Determination of folding fastness of leather physical and mechanical tests"; among which, the leather fabric was tested in a wet state, and the number of folding cycles was 25,000.

[0086] Tear strength: The tear strength of leather fabrics was tested according to QB / T 2711-2005 "Physical and Mechanical Tests of Leather: Determination of Tear Strength - Bilateral Tear".

[0087] The test results are shown in Table 1 below:

[0088] Table 1 Test Results

[0089]

[0090] Compared to Comparative Examples 1-3, the tear strength and folding strength of the crack-resistant leather fabric in Example 1 were significantly enhanced, indicating that the intermediate foam layer includes water-based polyurethane resin and a tackifier. When the tackifier includes carboxymethyl hydroxyethyl cellulose and carboxymethyl cellulose, the combined use of these three components can improve the crack resistance of the leather fabric. Compared to Comparative Example 4, the tear strength and folding strength of the crack-resistant leather fabric in Example 1 were significantly enhanced, indicating that the addition of wood flour to the surface leather layer can also improve the crack resistance of the leather fabric.

[0091] Compared to Examples 2 and 4, the tear strength of the crack-resistant leather fabrics in Examples 5 and 6 is enhanced, indicating that a weight ratio of waterborne polyurethane resin to tackifier of 8-11:1 can improve the crack resistance of the leather fabric. Compared to Examples 6 and 7, the tear strength of the crack-resistant leather fabrics in Examples 8 and 9 is enhanced, indicating that a weight ratio of carboxymethyl hydroxyethyl cellulose to carboxymethyl cellulose of 1-3:1 can improve the crack resistance of the leather fabric. Compared to Example 9, the tear strength of the crack-resistant leather fabrics in Examples 10-13 is enhanced, indicating that the wood flour is modified wood flour, and the modified wood flour obtained by modifying wood flour with diatomaceous earth and styrene-maleic anhydride copolymer can further improve the crack resistance of the leather fabric. In addition, compared with Examples 10-11, the tear strength of the crack-resistant leather fabrics in Examples 12-13 is enhanced, indicating that the crack resistance of the leather fabric can be further improved when the weight ratio of wood flour, diatomaceous earth and styrene-maleic anhydride copolymer is 7-11:0.5:0.5.

[0092] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A crack-resistant leather fabric, characterized in that, It includes a surface leather layer, an intermediate foam layer and a bottom base fabric layer arranged sequentially from top to bottom. The surface leather layer includes the following components in parts by weight: 45-65 parts polyurethane resin, 40-50 parts dimethylformamide, 20-30 parts wood flour, 0.5-1.5 parts antioxidant and 1-3 parts plasticizer. The intermediate foaming layer comprises the following components in parts by weight: 46-67 parts of waterborne polyurethane resin, 20-35 parts of polyetherimide, 1-2 parts of glass fiber, 4-14 parts of tackifier, and 8-16 parts of foaming agent. The thickener includes carboxymethyl hydroxyethyl cellulose and carboxymethyl cellulose; The weight ratio of the waterborne polyurethane resin to the tackifier is 8~11:1; The weight ratio of carboxymethyl hydroxyethyl cellulose to carboxymethyl cellulose is 1~3:

1.

2. The anti-cracking leather fabric according to claim 1, characterized in that, The wood flour is modified wood flour, which is obtained by modifying wood flour with diatomaceous earth and styrene-maleic anhydride copolymer.

3. The anti-cracking leather fabric according to claim 2, characterized in that, The modified wood flour is made from wood flour, diatomaceous earth, and styrene-maleic anhydride copolymer. The weight ratio of the wood flour, diatomaceous earth, and styrene-maleic anhydride copolymer is 7~11:0.5:0.

5.

4. The anti-cracking leather fabric according to claim 3, characterized in that, The method for preparing the modified wood flour includes the following steps: dissolving the styrene-maleic anhydride copolymer in ethyl acetate to obtain a styrene-maleic anhydride copolymer solution; adding wood flour and diatomaceous earth to the styrene-maleic anhydride copolymer solution; stirring; and concentrating to obtain the modified wood flour.

5. The anti-cracking leather fabric according to claim 1, characterized in that, The antioxidant is one or more of antioxidant 168, antioxidant 1010, and antioxidant 1076.

6. The anti-cracking leather fabric according to claim 1, characterized in that, The plasticizer is one or both of dioctyl phthalate and dioctyl adipate.

7. The anti-cracking leather fabric according to claim 1, characterized in that, The foaming agent is one or more of azobisisobutyronitrile, diisopropyl azodicarbonate, and diethyl azodicarbonate.

8. The manufacturing process of a crack-resistant leather fabric according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. The components in the surface leather layer are blended by weight and calendered to obtain the surface leather layer; S2. After mixing and grinding the water-based polyurethane resin, polyetherimide, and glass fiber in the intermediate foaming layer, add a tackifier and a foaming agent to obtain a mixed slurry. Coat the mixed slurry on the lower surface of the surface leather layer and foam it to obtain the intermediate foaming layer. S3. Bond the intermediate foam layer and the bottom base fabric layer to obtain the crack-resistant leather fabric.

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