Velvet-feeling plain leather PU leather in automobile field and preparation method of velvet-feeling plain leather PU leather

Abstract

The invention relates to the field of PU (polyurethane), and particularly discloses velvet-feeling plain leather automotive field PU leather and a preparation method thereof.The velvet-feeling plain leather automotive field PU leather comprises a surface layer, a texture layer, a solvent-free layer and a base cloth layer, the texture layer further comprises plasma-treated zeolite, and the solvent-free layer further comprises potassium neodecanoate-loaded zeolite. The PU leather prepared by the invention has relatively high strength and breathable effect, is suitable for relatively high-grade automobile skin, and has relatively high value in the aspects of realizing light weight of an automobile, improving the use feeling of a customer and the like.

Description

Technical Field

[0001] This application relates to the field of PU materials, and more specifically, it relates to a PU leather for the automotive field with a suede-like texture and its preparation method. Background Art

[0002] The conventional products of existing automotive covering materials are limited to traditional PVC and wet-process PU. The wet-process PU leather uses aqueous PU slurry and does not contain harmful solvents (such as DMF) in traditional solvent-based PU leather, reducing environmental pollution and meeting modern environmental protection requirements. At the same time, it has good flex resistance and softness, and can achieve various surface effects, such as embossing, printing, and graining, through different coating and curing processes to meet the design requirements of different products. However, compared with natural leather, it has many disadvantages in terms of physical properties and cannot meet requirements such as odor and breathability.

[0003] At present, the general improvement methods for the breathability of PU leather include setting diamond-shaped ventilation openings on the surface and adding functional fillers such as silica or alumina to increase the porosity. However, this will result in poor handfeel of the PU leather, and at the same time, it will cause a decrease in the compatibility with the substrate and the interlayer adhesion, and the service life is relatively low. Another common method to increase breathability is to add a foaming agent to increase the foaming effect. However, the foaming efficiency depends on appropriate reaction temperature and mixing ratio. If the temperature is too low or the mixing ratio is improper, it will directly affect the foaming rate and foam structure. If used in excess, it may lead to excessive foaming and too much early foaming, which will not only affect the physical properties of the product but also may cause instability in the production process, indicating that its applicability in different material systems may have limitations.

[0004] In order to provide a PU leather material for the automotive field that can make up for the market, can be adjacent to the antique suede handfeel style of genuine leather, can endow the suede effect by itself and meet market demands and experiences, can be upgraded to a high-end leather material for automotive interiors for use in high-end models, a super-fine suede-like strength leather material that can completely replace the disadvantages of traditional PVC and genuine leather in the past is developed, which has the effects of being skin-friendly and having excellent breathability, and has high value for realizing the lightweight of the vehicle itself and enhancing the feelings of customers during use. Summary of the Invention

[0005] In order to solve the problem of the PU leather for the automotive field with a suede-like texture for automotive interiors having both breathability and strength, this application provides a PU leather for the automotive field with a suede-like texture and its preparation method.

[0006] In a first aspect, the present application provides a PU leather with a velvety artificial leather feel for the automotive field, which includes a surface layer, a texture layer, a solvent-free layer, and a base fabric layer. The surface layer contains the following raw materials in parts by weight: 50-90 parts of a semi-bright and matte surface treatment agent, 45-60 parts of a brightening surface treatment agent, 5-8 parts of a cross-linking agent, 3-6 parts of an abrasion-resistant agent, 0.5-2.0 parts of a leveling agent, 0.1-3.0 parts of a wetting agent, 0.1-3.0 parts of a skin feel agent, and 10-40 parts of water. The texture layer contains the following raw materials in parts by mass: 95-105 parts of a PU polycarbonate resin, 55-75 parts of DMF, 15-25 parts of ethyl acetate, and 7-28 parts of a color paste. The solvent-free layer contains the following raw materials in parts by weight: 90-110 parts of a solvent-free adhesive A material, 100-120 parts of a solvent-free adhesive B material, 0.2-0.8 parts of a gel catalyst, 0.05-0.15 parts of a foaming catalyst, 0.15-0.25 parts of a leveling agent, and 40-60 parts of a flame retardant.

[0007] By adopting the above technical solution, the raw materials in the formula have appropriate viscosities, have a relatively comfortable hand feeling, and the adhesion of each layer is uniform and tight. Using a PU polycarbonate resin to prepare the texture layer has both strength and elasticity, and realizes a uniform texture effect in the system. The solvent-free layer has fine foaming, and has good air permeability and support effect.

[0008] Preferably, the adhesive A material is a polyether polyol, the adhesive B material is an isocyanate prepolymer, and the foaming catalyst includes potassium neodecanoate.

[0009] By the above technical solution, using potassium neodecanoate as the foaming catalyst can quickly catalyze the reaction of isocyanate and polyether polyol, especially the trimerization reaction in which two -NCO groups combine with one -OH group to form a cyclic structure, thereby improving the reaction rate and production efficiency. It can also effectively control the open-cell structure of the foam, making the density uniformity, surface smoothness and strength of the foam significantly improved, and the physical properties of the foam are significantly enhanced. The artificial leather prepared after curing has good performance in air permeability, mechanical strength, thermal stability and dimensional stability.

[0010] In a specific feasible embodiment, the texture layer further includes 5-20 parts by mass of plasma-treated zeolite, and the solvent-free layer further includes 5-20 parts by mass of potassium neodecanoate-loaded zeolite.

[0011] The structure of zeolite is mainly composed of tetrahedral units consisting of silicon and aluminum. These tetrahedrons form a three-dimensional network framework by sharing oxygen atoms. This framework structure endows zeolite with a highly ordered pore and channel system. By adding a certain mass of zeolite to the texture layer, the texture layer forms a more natural natural texture, higher strength, and better air permeability. By subjecting zeolite to plasma modification, the zeolite achieves better compatibility in the texture layer, and at the same time, more active hydroxyl groups are introduced on the zeolite surface. During the preparation of PU leather, after loading the texture layer raw materials on the solvent-free layer, the active hydroxyl groups on the plasma-treated zeolite may participate in the trimerization reaction catalyzed by potassium neodecanoate in the solvent-free layer, further enhancing the interlayer connection strength and air permeability effect. By adding a certain mass of zeolite to the solvent-free layer, the air permeability and strength of the solvent-free layer are improved. By loading potassium neodecanoate on the zeolite, during the curing process of the solvent-free layer, the potassium neodecanoate on the zeolite can have a certain slow-release effect. Since the catalytic effect of potassium neodecanoate is relatively dependent on an appropriate mixing ratio, the addition amount directly affects the foaming rate and foam structure. Excessive use leads to over-foaming, which affects the density and strength of the foam, resulting in the substandard strength of the prepared artificial leather. If the addition amount is too small, the catalytic effect will be insufficient. By loading potassium neodecanoate on the zeolite, the foaming structure and curing speed of the artificial leather are adjusted. Potassium neodecanoate can achieve a good catalytic effect on both the solvent-free layer and the plasma-treated zeolite in contact with the subsequent coating. The prepared artificial leather has uniform and sufficient foaming, a large bonding strength between the texture layer and the solvent-free layer, and greatly improves the service performance of the prepared PU artificial leather.

[0012] Preferably, the treatment power of the plasma-treated zeolite is 200 - 300 W, and the treatment time is 1.5 - 2.5 minutes.

[0013] By adopting the above technical solution, the zeolite is fully modified, and more active groups are formed on the surface, significantly improving the roughness and polarity of the zeolite surface. At the same time, the modification effect will not be reduced due to excessive power, and the surface hydroxyl groups can react well with the isocyanate prepolymer.

[0014] Preferably, the preparation steps of potassium neodecanoate-loaded zeolite include: dropping potassium neodecanoate into zeolite, stirring, and performing negative pressure treatment to obtain potassium neodecanoate-loaded zeolite. The mass ratio of potassium neodecanoate to zeolite is (0.01 - 0.15):10.

[0015] By adopting the above technical solution, the preparation steps are simple, the slow-release effect of the prepared potassium neodecanoate-loaded zeolite is appropriate, which is suitable for the component setting and preparation process of the multi-layer structure artificial leather of this application, and can achieve a strong connection between layers.

[0016] Preferably, the mass ratio of the plasma-treated zeolite to the potassium neodecanoate-loaded zeolite is (1.5 - 2.5):1.

[0017] By adopting the above technical solution, the mass ratio of the plasma-treated zeolite to the potassium neodecanoate-loaded zeolite is defined, further improving the compatibility between the slow-release effect of potassium neodecanoate and the surface active groups of the modified zeolite. The interlayer bonding strength and foaming effect are good, and it will not cause internal curing and insufficient cohesion in the solvent-free layer due to excessive reaction between the modified zeolite and the isocyanate prepolymer in the solvent-free layer, nor will it cause over-catalysis due to excessive potassium neodecanoate-loaded zeolite.

[0018] Preferably, the mass ratio of the isocyanate prepolymer, potassium neodecanoate, and potassium neodecanoate in the potassium neodecanoate-loaded zeolite is: 100:(0.04 - 0.07):0.10.

[0019] By adopting the above technical solution, the mixing ratio of potassium neodecanoate and potassium neodecanoate in the potassium neodecanoate-loaded zeolite to the isocyanate prepolymer is appropriate. First, the potassium neodecanoate in the system can catalyze the reaction between the isocyanate and the polyether polyol in the solvent-free layer, and then the potassium neodecanoate in the system and the potassium neodecanoate in the potassium neodecanoate-loaded zeolite can jointly catalyze the isocyanate, polyether polyol, and plasma-modified zeolite in the system, which is suitable for the remaining -NCO concentration in the system and effectively regulates the generation of pores. The pores in the prepared PU leather are more uniform and dense, the foam structure is stable, and the prepared PU leather has both good air permeability and strength.

[0020] Preferably, the average particle size of the zeolite is 0.30 - 0.80 nm.

[0021] By adopting the above technical solution, the average particle size of the zeolite is suitable for the texture layer, the viscosity of the base fabric layer, and the raw material settings of the present application, enabling relatively uniform dispersion, compatibility, and good air permeability. At the same time, the prepared PU leather has a relatively soft hand feeling.

[0022] In the second aspect, the present application provides a method for preparing a PU leather with a suede-like texture for the automotive field, including the following steps: S1: According to the proportion of parts by weight of the formula, mix the raw materials of the texture layer evenly and coat them on the release paper. Control the coating thickness at (0.15 ± 0.01) mm and the vehicle speed at (10 ± 1) m / min, and heat to obtain a semi-finished texture layer. S2: According to the proportion of parts by weight of the formula, mix the raw materials of the solvent-free layer evenly and coat them on the surface of the semi-finished texture layer. The coating thickness is (0.30 ± 0.01) mm, the vehicle speed is controlled at (10 ± 1) m / min, and heat to obtain a PU middle layer. S3: Add the base fabric layer: Bond the solvent-free layer side of the PU middle layer to the base fabric, heat, and then separate the release paper. The side where the release paper is separated is the texture surface to make a PU semi-finished product. S4: According to the proportion of parts by weight of the formula, stir the surface layer raw materials evenly, and then roll-coat them on one side of the textured surface of the PU semi-finished product. Control the vehicle speed at (8±1) m / min, heat and dry, and then curl to obtain the PU leather with a suede-like finish for the automotive field.

[0023] By adopting the above technical solution, the preparation method is simple, the process requirements are low, good bonding can be achieved between layers, and the plasma-treated zeolite, potassium neodecanoate, and potassium neodecanoate-loaded zeolite in the texture layer and the solvent-free layer can have good contact and play their roles.

[0024] In a specific feasible embodiment, the heating in S1 is carried out successively at 70 / 80 / 100 / 110 / 120 °C, and the total heating time is 2 - 2.5 minutes. The heating in S2 is carried out successively at 135 / 140 / 145 °C, and the total heating time is 12 - 14 minutes. The heating in S4 is carried out successively at 120 / 125 / 130 °C, and the total heating time is 2 - 3 minutes.

[0025] By adopting the above technical solution, the curing is uniform, the stress of each layer can be fully released during the heating process, the structure of the obtained PU is more stable. The texture layer has a semi-dried effect, and a certain polymerization occurs inside the solvent-free layer raw materials first, and then it is coated on the surface of the semi-dried texture layer semi-finished product. The zeolite protruding slightly on the interface where the two are in contact realizes a closer combination through mechanical bonding and chemical cross-linking between layers, and the obtained PU leather has better strength performance.

[0026] In summary, the present application has the following beneficial effects: By setting the raw material quality of the surface layer, texture layer, solvent-free layer, and base fabric layer in the present application, the obtained PU leather has good comprehensive performance. The binder A is specified as polyether polyol with a certain mass, the binder B is an isocyanate prepolymer, the foaming catalyst includes potassium neodecanoate, and further, the texture layer is specified to include plasma-treated zeolite, and the solvent-free layer includes potassium neodecanoate-loaded zeolite, optimizing the polymerization and foaming structure, enabling the plasma-treated zeolite on the interface between the texture layer and the solvent-free layer to participate in the polymerization of the solvent-free layer, and the obtained PU leather has both breathability and strength performance. Further, by limiting the mass ratio of the plasma-treated zeolite and the potassium neodecanoate-loaded zeolite, the mass ratio of potassium neodecanoate in the isocyanate prepolymer, potassium neodecanoate, and potassium neodecanoate-loaded zeolite, the average particle size of the zeolite, etc., the performance of the product is further improved.

[0027] By limiting the preparation sequence, heating temperature, and time during the preparation process, it is more suitable for the raw material setting of the present application, better mechanical bonding and chemical polymerization are achieved between layers, and the obtained PU leather has better breathability and strength performance. Description of the Drawings

[0028] Figure 1: Schematic diagram of the product structure of PU leather in the field of suede-like artificial leather for automobiles.

[0029] Explanation of reference numerals: 1, surface layer; 2, texture layer; 3, solvent-free layer; 4, base fabric. Specific implementation manners

[0030] The present application will be further described in detail below in conjunction with examples and comparative examples.

[0031] To further help understand the technical solution of the present invention, several specific examples are provided to describe the technical solution of the present invention more specifically. All these described examples are only partial examples of the present invention, not all; the examples can be combined with each other, and the same or similar concepts or processes may not be repeated in some examples. The following examples are further descriptions of the present invention, and the present invention is not limited thereto.

[0032] The chemical reagents in the examples and comparative examples are commercially available conventional reagents if not specified.

[0033] The particle size of the zeolite is 0.53 - 0.58 nm, purchased from Pioneer Nano XFF04; the semi-gloss and matte surface treatment agent is the 13-085 water-based polycarbonate aliphatic polyurethane from Jining Tangyi Chemical Co., Ltd.; the brightening surface treatment agent is Suractent 185S; the cross-linking agent is polycarbodiimide CDI cross-linking agent; the wear-resistant agent is 186 water-based silicone; the wetting agent is sodium dodecyl sulfate; the skin feel agent is LM-3033 silky hand feel agent; the solvent-free adhesive A component is polyether polyol; the solvent-free adhesive B component is isocyanate prepolymer; the gel catalyst is NT CAT 680; the filling flame retardant is aluminum hydroxide.

[0034] Preparation examples Preparation example 1: Plasma treatment of zeolite Put 10 g of zeolite into a plasma reactor, with a vacuum degree of 30 Pa, and introduce oxygen at a flow rate of 30 cm 3 / min, and perform plasma treatment for 60 seconds at 300 W to obtain plasma-treated zeolite.

[0035] Preparation example 2: Loading of potassium neodecanoate on zeolite Drop 0.10 g of potassium neodecanoate into 10 g of zeolite, stir at 2500 r / min for 5 minutes, and evacuate to a negative pressure of -0.1 MPa to obtain potassium neodecanoate-loaded zeolite.

[0036] Preparation example 3: Plasma treatment of zeolite Put 10 g of zeolite into a plasma reactor, with a vacuum degree of 30 Pa, and introduce oxygen at a flow rate of 30 cm 3Oxygen is introduced at a flow rate of / min, and the zeolite is treated with 100 W plasma for 60 seconds to obtain plasma-treated zeolite.

[0037] Preparation Example 4: Potassium neodecanoate-loaded zeolite 0.20 g of potassium neodecanoate was dropped into 10 g of zeolite, stirred at 2500 r / min for 5 minutes, and evacuated to a negative pressure of -0.1 MPa to obtain potassium neodecanoate-loaded zeolite. Examples

[0038] Example 1 The raw materials of this example are as follows: Surface layer: 50 g of semi-gloss matt surface treatment agent, 60 g of brightening surface treatment agent, 5 g of cross-linking agent, 6 g of wear-resistant agent, 0.5 g of leveling agent, 3.0 g of wetting agent, 0.1 g of skin feel agent, 40 g of water; Texture layer: 95 g of PU polycarbonate resin, 75 g of DMF, 15 g of ethyl acetate, 28 g of color paste; Solvent-free layer: 90 g of solvent-free adhesive A, 120 g of solvent-free adhesive B, 0.2 g of gel catalyst, 0.15 g of foaming catalyst, 0.15 g of leveling agent, 60 g of flame retardant.

[0039] Base fabric: Non-woven fabric.

[0040] S1: According to the proportion of the formula by weight, the raw materials of the texture layer are mixed evenly and coated on the release paper, the coating thickness is controlled at (0.15 ± 0.01) mm, the vehicle speed is controlled at (10 ± 1) m / min, and heated at 70 / 80 / 100 / 110 / 120 °C in turn, and each temperature is maintained for 0.5 minutes to obtain the semi-finished texture layer; S2: According to the proportion of the formula by weight, the raw materials of the solvent-free layer are mixed evenly and coated on the surface of the semi-finished texture layer, the coating thickness is (0.30 ± 0.01) mm, the vehicle speed is controlled at (10 ± 1) m / min, and heated at 135 / 140 / 145 °C in turn, and each temperature is heated for 4 minutes to obtain the PU middle layer; S3: Add the base fabric layer: Bond the solvent-free layer side of the PU middle layer to the base fabric, heat at 140 °C until dried, and then separate the release paper. The side where the release paper is separated is the texture side to make the PU semi-finished product; S4: According to the proportion of the formula by weight, stir the raw materials of the surface layer evenly, and then roll-coat them on the texture side of the PU semi-finished product with a roll coater. The vehicle speed is controlled at (8 ± 1) m / min, and heated at 120 / 125 / 130 °C in turn, and each temperature is heated for 1 minute. After drying, it is curled to obtain the velvet-like artificial leather for the automotive field.

[0041] Example 2 The difference between this example and Example 1 is only that the raw materials of this example are as follows: Surface layer: 90 g of semi-gloss matte surface treatment agent, 45 g of brightening surface treatment agent, 8 g of crosslinking agent, 3 g of wear-resistant agent, 2.0 g of leveling agent, 0.1 g of wetting agent, 3.0 g of skin-friendly agent, 10 g of water; Texture layer: 105 g of PU polycarbonate resin, 55 g of DMF, 25 g of ethyl acetate, 7 g of color paste; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant.

[0042] Base fabric: Non-woven fabric.

[0043] Example 3 The difference between this example and Example 1 is only that the raw materials of this example are as follows: Surface layer: 70 g of semi-gloss matte surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin-friendly agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant.

[0044] Base fabric: Non-woven fabric.

[0045] Example 4 The difference between this example and Example 1 is only that the raw materials of this example are as follows: Surface layer: 70 g of semi-gloss matte surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin-friendly agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste, 10 g of plasma-treated zeolite prepared in Preparation Example 1; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant, 10 g of neodecanoate-loaded zeolite prepared in Preparation Example 2.

[0046] Base fabric: Non-woven fabric.

[0047] Example 5 The difference between this example and Example 1 is only that the raw materials of this example are as follows: Surface layer: 70 g of semi-gloss matt surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin-friendly agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste, 10 g of plasma-treated zeolite prepared in Preparation Example 3; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant, 10 g of neodecanoate-loaded zeolite prepared in Preparation Example 2.

[0048] Base fabric: Non-woven fabric.

[0049] Example 6 The difference between this example and Example 1 is only that the raw materials in this example are as follows: Surface layer: 70 g of semi-gloss matt surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin-friendly agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste, 10 g of plasma-treated zeolite prepared in Preparation Example 3; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant, 10 g of neodecanoate-loaded zeolite prepared in Preparation Example 4.

[0050] Base fabric: Non-woven fabric.

[0051] Example 7 The difference between this example and Example 1 is only that the raw materials in this example are as follows: Surface layer: 70 g of semi-gloss matt surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin-friendly agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste, 13 g of plasma-treated zeolite prepared in Preparation Example 1; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant, 7 g of neodecanoate-loaded zeolite prepared in Preparation Example 2.

[0052] Base fabric: Non-woven fabric.

[0053] Example 8 The difference between this embodiment and Embodiment 1 is only that the raw materials of this embodiment are as follows: Surface layer: 70 g of semi-gloss matting surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin feel agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 65 g of DMF, 20 g of ethyl acetate, 20 g of color paste, 15 g of plasma-treated zeolite prepared in Preparation Example 1; Solvent-free layer: 110 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 0.25 g of leveling agent, 40 g of flame retardant, 5 g of neodecanoate-loaded zeolite prepared in Preparation Example 2.

[0054] Base fabric: non-woven fabric.

[0055] Comparative example Comparative Example 1: The difference between this comparative example and Embodiment 1 is only that the raw materials of this embodiment are as follows: Surface layer: 70 g of semi-gloss matting surface treatment agent, 50 g of brightening surface treatment agent, 7 g of crosslinking agent, 5 g of wear-resistant agent, 1.5 g of leveling agent, 2.0 g of wetting agent, 2.0 g of skin feel agent, 25 g of water; Texture layer: 100 g of PU polycarbonate resin, 85 g of DMF, 20 g of color paste; Solvent-free layer: 100 g of solvent-free adhesive A, 100 g of solvent-free adhesive B, 0.8 g of gel catalyst, 0.05 g of foaming catalyst, 40 g of flame retardant.

[0056] Base fabric: non-woven fabric.

[0057] Performance detection test Test 1: (1) Specimen preparation: Prepare a rectangular specimen with a length of 200 mm and a width of 50 mm.

[0058] (2) Test method: Pre-peel the PU layer and the substrate by 50 mm along the test length direction, and there should be no obvious damage to the peeled part. If the specimen is not easy to tear, one end of the specimen can be immersed in the solvent for treatment. After the solvent has completely evaporated, clamp the two ends of the peeled part of the specimen on the testing machine respectively, so that the longitudinal axis of the peeled part of the specimen coincides with the center line of the upper and lower clamps, and the tightness is appropriate. Conduct the test at a speed of 200 ± 50 mm / min. During the test, the unpeeled part forms a T shape with the stretching direction, and the peel strength is tested.

[0059] Test 2: Refer to the standard QB / T 2799-2006 to detect the air permeability of the PU leather.

[0060] The test results are shown in Table 1.

[0061] Table 1 Peeling strength / (N×mm) <![CDATA[Air permeability / mL / (cm 2 *h)]]> Example 1 26.11 891 Example 2 26.20 890 Example 3 26.32 900 Example 4 32.34 1286 Example 5 30.11 1277 Example 6 29.01 1019 Example 7 35.14 1294 Example 8 32.44 1280 Comparative Example 1 13.95 886 Combined with Examples 1-3, Comparative Example 1 and Table 1, in this application, by setting the surface layer, texture layer, solvent-free layer and base fabric at one time and making certain raw material limitations, the comprehensive performance of the prepared PU leather is relatively good.

[0062] Combined with Examples 3-5 and Table 1, in this application, by adding a certain mass of plasma-treated zeolite to the texture layer, adding a certain mass of potassium neodecanoate-loaded zeolite to the solvent-free layer, and limiting the power of plasma treatment, the number of active groups on the zeolite surface is adjusted. While the zeolite increases the air permeability, a certain amount of potassium neodecanoate exists in the system, and a part of potassium neodecanoate is slowly released from the zeolite, improving the foaming speed and structure, and enhancing the interlayer polymerization and mechanical bonding. The prepared PU leather has high peel strength and air permeability performance.

[0063] Combined with Examples 3-6 and Table 1, in this application, by limiting the concentration of zeolite in potassium neodecanoate-loaded zeolite, the polymerization and foaming states are further adjusted, and the prepared PU leather has higher strength performance.

[0064] Combined with Examples 4, 7-8 and Table 1, in this application, by limiting the mass ratio of plasma-treated zeolite in the texture layer to potassium neodecanoate-loaded zeolite in the solvent-free layer, the prepared PU leather has higher peel strength and air permeability performance.

[0065] The use of this specific embodiment in this application is only an explanation of this application, and it is not a limitation of this application. After reading this specification, those skilled in the art can make modifications that do not contribute creatively to this embodiment as needed, but as long as they are within the scope of the claims of this application, they are protected by the patent law.

Claims

1. A velvety plain leather PU leather for automobiles, characterized in that: The invention comprises a surface layer, a texture layer, a solvent-free layer and a base fabric layer. The surface layer comprises the following raw materials in parts by weight: 50-90 parts of a semi-bright matte surface treatment agent, 45-60 parts of a brightening surface treatment agent, 5-8 parts of a cross-linking agent, 3-6 parts of an anti-wear agent, 0.5-2.0 parts of a leveling agent, 0.1-3.0 parts of a wetting agent, 0.1-3.0 parts of a skin feeling agent, and 10-40 parts of water. The texture layer comprises the following raw materials in parts by weight: PU polycarbonate 95-105 parts of resin, 55-75 parts of DMF, 15-25 parts of ethyl acetate, 7-28 parts of color paste, and the solvent-free layer contains the following raw materials in parts by weight: 90-110 parts of solvent-free adhesive A material, 100-120 parts of solvent-free adhesive B material, 0.2-0.8 parts of gel catalyst, 0.05-0.15 parts of foaming catalyst, 0.15-0.25 parts of leveling agent, and 40-60 parts of flame retardant.

2. The velvety plain leather automobile PU leather according to claim 1, characterized in that: The adhesive material A is polyether polyol, the adhesive material B is isocyanate prepolymer, and the foaming catalyst includes potassium neodecanoate.

3. The velvety plain leather automobile PU leather according to claim 2, characterized in that: The texture layer further comprises 5-20 parts by mass of plasma treated zeolite, and the solvent-free layer further comprises 5-20 parts by mass of potassium neodecanoate loaded zeolite.

4. The velvety plain leather automobile PU leather according to claim 3, characterized in that: The plasma treatment zeolite has a treatment power of 200-300W and a treatment time of 1.5-2.5 minutes.

5. The velvety plain leather for automobiles according to claim 3, characterized in that: The preparation steps of the potassium neodecanoate-loaded zeolite include: dropping potassium neodecanoate into zeolite, stirring, and treating under negative pressure to obtain the potassium neodecanoate-loaded zeolite, wherein the mass ratio of potassium neodecanoate to zeolite is (0.01-0.15):

10.

6. The velvety plain leather for automobiles according to claim 3, characterized in that: The mass ratio of the plasma treated zeolite to the potassium neodecanoate loaded zeolite is (1.5-2.5):

1.

7. The velvety plain leather for automobiles according to claim 3, characterized in that: The mass ratio of the isocyanate prepolymer, potassium neodecanoate and potassium neodecanoate in the potassium neodecanoate-loaded zeolite is: 100: (0.04-0.07): 0.

10.

8. The velvety plain leather automobile PU leather according to claim 3, characterized in that: The average particle size of the zeolite is 0.30-0.80 nm.

9. A method for preparing a velvety plain leather PU leather for automobiles according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: According to the weight ratio of the formula, the texture layer raw materials are mixed and evenly coated on the release paper, the coating thickness is controlled at (0.15±0.01) mm, the vehicle speed is controlled at (10±1) m / min, and heating is performed to obtain a texture layer semi-finished product; S2: According to the weight ratio of the formula, the raw materials of the solvent-free layer are mixed evenly, and applied to the surface of the texture layer semi-finished product, with a coating thickness of (0.30±0.01) mm, and the vehicle speed is controlled at (10±1) m / min, and heated to obtain a PU middle layer; S3: Adding a base fabric layer: Laminating one side of the solvent-free layer of the PU middle layer to the base fabric, heating it, and then separating the release paper, where one side of the separated release paper is a textured surface, to make a PU semi-finished product; S4: According to the weight ratio of the formula, the surface layer raw materials are mixed evenly, and then coated on the texture side of the PU semi-finished product with a roller coater, and the speed is controlled at (8±1) m / min. After heating and drying, curling is obtained to obtain velvety plain leather automotive PU leather.

10. The method for preparing velvety plain leather PU leather for automobiles according to claim 9, characterized in that: The heating in S1 is sequentially heated at 70 / 80 / 100 / 110 / 120°C for a total heating time of 2-2.5 minutes, the heating in S2 is sequentially heated at 135 / 140 / 145°C for a total heating time of 12-14 minutes, and the heating in S4 is sequentially heated at 120 / 125 / 130°C for a total heating time of 2-3 minutes.

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