Preparation method of high-wear-resistance water-based polyurethane double-napped microfiber leather

Abstract

The application belongs to the technical field of water-based polyurethane suede microfiber synthetic leather, and discloses a preparation method of high-wear-resistance water-based polyurethane double-suede microfiber leather. The preparation method is as follows: first, island fiber non-woven fabric is immersed in water-based polyurethane slurry; then, the immersed island fiber non-woven fabric is heat treated to obtain an intermediate product; subsequently, the temperature of the intermediate product is adjusted to a proper temperature; then, the intermediate product is extruded on a roller; after the extrusion, the intermediate product is dried and solidified; after the solidification, a solvent capable of dissolving the non-woven fabric sea phase material is used to open the fibers to obtain a microfiber base cloth; finally, the microfiber base cloth is raised to obtain the high-wear-resistance water-based polyurethane double-suede microfiber leather. The water-based polyurethane is gathered in the middle part of the non-woven fabric to form a base layer to realize tight covering of the fibers, thereby avoiding the problem that the water-based polyurethane is accumulated in the raised layer to affect the raising effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water-based polyurethane suede microfiber synthetic leather, and relates to a preparation method of high-wear-resistance water-based polyurethane double-suede microfiber leather. BACKGROUND

[0002] Polyurethane suede microfiber leather has been widely used as a high-quality substitute for suede leather due to its unique performance advantages. In the process of preparing polyurethane suede microfiber leather, traditional technologies mostly use solvent-based polyurethane. During production using this process, the solvent-based polyurethane fills the space between the fibers in the non-woven fabric during impregnation and is coagulated by replacing DMF with water, finally forming a continuous polyurethane resin structure that tightly wraps around the fibers.

[0003] However, with the improvement of environmental awareness and the emphasis on safe production, water-based polyurethane has attracted more and more attention in the microfiber leather industry due to its safer and more environmentally friendly characteristics. However, after water-based polyurethane is impregnated into non-woven fabric, the particles move and accumulate during the heating and curing process, and are unevenly adhered and solidified on the surface of the fibers, forming a discontinuous resin film and poor fiber wrapping, resulting in weak fiber grip and poor wear resistance, and easy shedding.

[0004] To solve the above problems, there are currently two common methods for water-based polyurethane suede. One method is to control the directional migration of water-based polyurethane to both sides of the non-woven fabric, forming a fiber layer without resin accumulation in the middle, and then dividing it into two pieces using a sheeting process to serve as the suede raising layer. However, although this method has good suede raising effect, it destroys the fiber structure in the non-woven fabric, resulting in reduced mechanical properties of the finished product, and does not solve the problems of discontinuous water-based polyurethane resin film and poor fiber wrapping.

[0005] The other method is to control the directional movement and accumulation of water-based polyurethane to one side of the non-woven fabric, and use the fiber layer on the other side without resin as the suede raising layer. However, this method also fails to avoid the problem of uneven accumulation of water-based polyurethane in the non-woven fabric, so the fiber wrapping effect is still not ideal.

[0006] Patent CN115613371A discloses a preparation method of high-wear-resistance water-based polyurethane microfiber base fabric, mainly by using water-soluble polyester as the sea phase of the island-in-sea fiber and a two-time impregnation and curing process of water-based polyurethane to improve the Martin wear resistance of the water-based polyurethane base fabric. This method is suitable for specific island-in-sea fibers and has a narrow application range. At the same time, this method fails to solve the problem of accumulation and entanglement of water-based polyurethane between the fibers on the surface layer of the non-woven fabric, mainly by forming the suede layer of the finished product on the part of the non-woven fabric where the fibers tend to stand upright on the surface of the non-woven fabric. The suede of the product is not dense, and the two-time impregnation and curing process has high requirements for equipment and process control, and the processing cost is also high.

[0007] Therefore, it is necessary to provide a preparation method of high wear-resistant waterborne polyurethane double-napped microfiber leather to solve the above problems, which has very important significance. SUMMARY

[0008] The purpose of the present application is to solve the problems existing in the prior art and provide a preparation method of high wear-resistant waterborne polyurethane double-napped microfiber leather.

[0009] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0010] A preparation method of high wear-resistant waterborne polyurethane double-napped microfiber leather, comprising the following steps:

[0011] (1) Raw material preparation;

[0012] The raw materials of the high wear-resistant waterborne polyurethane double-napped microfiber leather include island fiber non-woven fabric and waterborne polyurethane slurry;

[0013] The density of the island fiber non-woven fabric is 0.23-0.38 g / cm 3 ; If the density is too low, the distance between the non-woven fabric fibers is too far, and more waterborne polyurethane is needed to coat the fibers, which is high in cost and the finished product is hard in hand feeling; If the apparent density of the non-woven fabric is too high, the fibers are tightly packed, which is not conducive to the waterborne polyurethane gel being extruded into the middle part of the non-woven fabric to form a base layer to realize the tight coating of the fibers;

[0014] The waterborne polyurethane slurry is composed of waterborne polyurethane emulsion and electrolyte aqueous solution, so that the waterborne polyurethane slurry has the property of heat-induced gel; For example, 0.7-2.3% of electrolyte aqueous solution is added to the waterborne polyurethane emulsion, and the mass fraction of the electrolyte aqueous solution in the waterborne polyurethane slurry is 33-57wt%, so that the prepared waterborne polyurethane slurry has the property of heat-induced gel, and the waterborne polyurethane slurry can change from liquid state to gel state; The gel state waterborne polyurethane does not migrate with the volatilization of water, and is accumulated in the middle part of the non-woven fabric under the extrusion of the roller, so that the water is volatilized and accumulated in the middle part of the non-woven fabric during subsequent drying and curing; If the mass fraction of the electrolyte aqueous solution in the waterborne polyurethane slurry is too low, the waterborne polyurethane slurry cannot be gelled, and if the mass fraction is too high, the waterborne polyurethane emulsion will be broken; The electrolyte is, for example, common Na2SO4, NaCl, KCl, K2SO4, etc.;

[0015] (2) Impregnation;

[0016] The island fiber non-woven fabric is immersed in the water-based polyurethane slurry, and the liquid rate is controlled to be at least 160%; the slurry immersed in the non-woven fabric is distributed in the non-woven fabric in the following step (4), and if the liquid rate is less than 160%, it is difficult to achieve the ideal coating effect due to the too low liquid rate, regardless of the adjustment of the extrusion strength;

[0017] (3) heat treatment;

[0018] The treatment at a heat treatment temperature of 90-120°C makes the water-based polyurethane completely gel, and the intermediate product is obtained, and the water evaporation degree in the heat treatment process is controlled, so that the water content of the gelled water-based polyurethane in the intermediate product is ≥48%;

[0019] If the heat treatment temperature is too low, it is not conducive to the complete gelation of the water-based polyurethane slurry, and there is part of the liquid slurry in the non-woven fabric, which will be sucked back to the surface of the non-woven fabric and entangled with the fibers during the roller extrusion treatment, affecting the raising; if the heat treatment temperature is too high, the polyurethane gel close to the surface of the non-woven fabric will be seriously cross-linked and solidified when the polyurethane slurry is completely gelled, and even form a film, which cannot be extruded into the non-woven fabric during the roller extrusion treatment and remains on the surface of the non-woven fabric, affecting the raising;

[0020] The water content of the water-based polyurethane slurry during the gelation process is controlled by adjusting the treatment time at the heat treatment temperature, and when the complete gelation is achieved, the treatment time should not be too long, otherwise the water loss will be serious; when the water content of the gelled water-based polyurethane is too low, the polyurethane slurry gel will be seriously solidified, which has been hardened during the roller extrusion, which is not conducive to the following step (4) roller extrusion of the water-based polyurethane gel to make it gather in the middle part of the non-woven fabric;

[0021] (4) roller extrusion treatment;

[0022] Before the extrusion treatment, the temperature of the intermediate product is adjusted to reach the hardening temperature of the non-woven fabric in the intermediate product, and is higher than 20°C, to avoid difficulty in extrusion; the hardening temperature is determined according to the following method: take the intermediate product after the heat treatment in step (3), adjust its temperature to the target temperature, and after extrusion by the target roller extrusion process, the total thickness loss is not more than 7%, which is considered as the hardening temperature of the intermediate product under the target roller process; for example, the hardening temperature of LDPE / PA is lower than 70°C, the hardening temperature of LDPE / PET is lower than 75°C, the hardening temperature of COPET / PA is lower than 125°C, the hardening temperature of COPET / PET is lower than 130°C, the hardening temperature of SWPET / PA is lower than 70°C, and the hardening temperature of SWPET / PET is lower than 75°C; the intermediate product in step (3) has a hardening effect, and the specific value will deviate from the raw material and process, which can be determined according to the method;

[0023] The target roll pressure is 0.20-0.30 MPa, and when the upper and lower rolls are extruded, the extrusion effect is too weak, the water-based polyurethane gel moves weakly into the non-woven fabric, a certain amount of fibers in the surface pile layer are wrapped by the polyurethane, and the pile layer is thin, the pile effect is poor, and if the extrusion effect is too strong, the polyurethane gel will be extruded out of the non-woven fabric, so that the polyurethane gel is mainly concentrated in the middle narrow part, the base layer is thin, and the wrapping effect on the fibers is not strong;

[0024] The intermediate product is roll extruded 3-5 times, if the number is less than 3 times, the resin is not sufficient in the intermediate part of the non-woven fabric, and the fiber wrapping cannot form sufficient wrapping; and if the number is greater than 5 times, it is difficult to obtain a hardening temperature meeting the requirements;

[0025] (5) drying and curing;

[0026] The intermediate product after roll extrusion is dried and cured; after drying and curing, the water-based polyurethane is concentrated in the middle part of the non-woven fabric to tightly wrap the fibers to form a base layer, and the surface layer is distributed as a pile layer;

[0027] (6) fiber opening;

[0028] The solvent capable of dissolving the non-woven fabric marine material is used for fiber opening to obtain a superfine base cloth; the selection of the solvent for fiber opening is a prior art, for example, toluene is used for LDPE, alkali is used for COPET, and water is used for SWPET (water-soluble polyester);

[0029] (7) pile raising;

[0030] The superfine base cloth is pile raised to obtain a high-wear-resistant water-based polyurethane double-pile superfine leather.

[0031] As a preferred technical solution:

[0032] The preparation method of the high-wear-resistant water-based polyurethane double-pile superfine leather as described above, the polyurethane solid content of the water-based polyurethane slurry in step (1) is 23-36%. It is appropriate that the slurry controls the polyurethane solid content to be 23-36%, the gel state water-based polyurethane gathered in the middle part of the non-woven fabric is volatilized to form voids, and the base cloth is soft. If the solid content is too low, the voids are too large, the hand feeling is empty and soft; and if the solid content is too high, the voids are small, the hand feeling is empty and hard.

[0033] The preparation method of the high-wear-resistant water-based polyurethane double-pile superfine leather as described above, the liquid retention rate is controlled to be within 240% in step (2), and the liquid retention rate that is too high will be extruded out in step (4).

[0034] As described above, the preparation method of a high wear-resistant waterborne polyurethane double-suede microfiber leather, the drying and curing in step (5) refers to drying at a temperature of 120~140℃ until the moisture content of the intermediate product is ≤0.02%, that is, the moisture evaporation rate is ≥99.8%.

[0035] The method for preparing a high abrasion-resistant waterborne polyurethane double-suede microfiber leather as described in any of the preceding claims, wherein the abrasion loss of the high abrasion-resistant waterborne polyurethane double-suede microfiber leather is 6~11mg.

[0036] Beneficial effects:

[0037] This invention utilizes materials with a density of 0.23~0.38 g / cm³. 3 The nonwoven fabric made of island-type fiber and the addition of an electrolyte solution to the waterborne polyurethane slurry to give it thermotropic gel properties allow the gel-state waterborne polyurethane to aggregate in the middle of the nonwoven fabric under the extrusion of the rollers, forming a base layer to achieve tight coating of the fibers. Furthermore, since the gel-state waterborne polyurethane does not migrate with the evaporation of water, the water will only accumulate in the middle of the nonwoven fabric during subsequent drying and curing, thus avoiding the problem of waterborne polyurethane accumulating in the napping layer and affecting the napping effect. Detailed Implementation

[0038] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0039] To ensure that the performance of the substances used in each embodiment and comparative example is fully disclosed, the manufacturers and brands of some substances are specified. Other products from other manufacturers and brands that conform to the limitations of this invention are also feasible.

[0040] The test methods for the relevant performance indicators in the following embodiments and comparative examples are as follows:

[0041] Abrasion loss: The high abrasion-resistant waterborne polyurethane double-suede microfiber leather prepared in each embodiment and the waterborne polyurethane double-suede microfiber leather prepared in each comparative example were used as samples. Then, the mass loss of the samples after 35,000 rubs was tested according to GB / T 21196.3-2007 standard, which is the abrasion loss.

[0042] The opening and the raising in each of the following examples and each of the comparative examples are conventional techniques in the art. The solvent used in the opening is selected according to the components in the island fiber nonwoven fabric, for example, toluene is used for the reduction of LDPE, alkali is used for the reduction of COPET, and water is used for the reduction of SWPET; the raising is performed by using a skin roller, and the surface layer of the microfiber base cloth is repeatedly polished by using sandpaper after the opening to form a pile surface layer. This process is to scatter the fibers after the pile surface layer is completely opened, and the surface is polished to be flat, so as to present the texture of suede. The process for the raising is a conventional process, and a person skilled in the art can make corresponding adjustments according to the requirements.

[0043] Example 1

[0044] A preparation method of a high-wear-resistance waterborne polyurethane double-pile microfiber leather is as follows:

[0045] (1) Preparation of raw materials;

[0046] Island fiber nonwoven fabric: LDPE / PA nonwoven fabric (the mass ratio of LDPE and PA is 70:30), and the apparent density of the LDPE / PA nonwoven fabric is 0.33 g / cm 3 ;

[0047] Waterborne polyurethane slurry: prepared by jointly adjusting waterborne polyurethane emulsion (the manufacturer is Dow Chemical, the model is YS-3000, and the solid content of polyurethane resin in the emulsion is 54%) and a 0.7wt% Na2SO4 aqueous solution. In the adjusting process, the Na2SO4 aqueous solution is added to the waterborne polyurethane emulsion until the solid content of polyurethane in the waterborne polyurethane slurry reaches 30%, and the mass proportion of the Na2SO4 aqueous solution in the waterborne polyurethane slurry is 44%;

[0048] (2) Immersion;

[0049] The island fiber nonwoven fabric is immersed in the waterborne polyurethane slurry, and the liquid rate is controlled to be 210%;

[0050] (3) Heat treatment;

[0051] The immersed island fiber nonwoven fabric is treated at a heat treatment temperature of 105℃, so that the waterborne polyurethane is completely gelled, and an intermediate product is obtained. The degree of water evaporation in the heat treatment process is controlled, so that the water content of the gelled waterborne polyurethane in the intermediate product is 60%;

[0052] (4) Roller extrusion treatment;

[0053] First, the temperature of the intermediate product is adjusted to 25℃, and then the intermediate product is subjected to three times of roller extrusion on a roller with a pressure of 0.2 MPa. After the extrusion, the total thickness loss is 5%;

[0054] (5) Drying and curing;

[0055] The intermediate product after roller extrusion is dried at a temperature of 120℃ until the moisture evaporation rate is 99.8%;

[0056] (6) Opening;

[0057] The opening is performed by using a solvent capable of dissolving the non-woven sea material to obtain the microfiber base cloth;

[0058] (7) Napping;

[0059] The napping is performed on the microfiber base cloth to obtain the high wear-resistant water-based polyurethane double-napped microfiber leather.

[0060] The wear amount of the finally prepared high wear-resistant water-based polyurethane double-napped microfiber leather is 6mg.

[0061] Comparative Example 1

[0062] A preparation method of a water-based polyurethane double-napped microfiber leather, which is basically the same as Example 1, except that the liquid carrying rate in step (2) is controlled to be 140%.

[0063] The wear amount of the finally prepared water-based polyurethane double-napped microfiber leather is 27mg.

[0064] Comparing Comparative Example 1 with Example 1, it can be seen that the wear amount of the water-based polyurethane double-napped microfiber leather prepared in Comparative Example 1 is larger, which is because when the liquid carrying rate is too low, the polyurethane slurry is not filled enough in the fiber gap, and it is difficult to achieve the ideal coating effect, thereby reducing the wear resistance of the water-based polyurethane double-napped microfiber leather.

[0065] Comparative Example 2

[0066] A preparation method of a water-based polyurethane double-napped microfiber leather, which is basically the same as Example 1, except that the water content of the gelatinized water-based polyurethane in the intermediate product of step (3) is 37%.

[0067] The wear amount of the finally prepared water-based polyurethane double-napped microfiber leather is 18mg.

[0068] Comparing Comparative Example 2 with Example 1, it can be seen that the wear amount of the high wear-resistant water-based polyurethane double-napped microfiber leather prepared in Comparative Example 2 is larger, which is because when the water content of the gelatinized water-based polyurethane is too low, the polyurethane slurry gelatinizes and solidifies seriously, and it is hardened during the roller extrusion, so that the water-based polyurethane gelatin cannot be gathered to the intermediate part of the non-woven cloth by the roller extrusion, thereby reducing the coating effect of the polyurethane slurry on the fiber and the wear resistance; at the same time, it also causes the fiber of the surface layer to be wrapped by the polyurethane, making the napping difficult, resulting in sparse fiber, poor napping feeling and appearance.

[0069] Comparative Example 3

[0070] A preparation method of water-based polyurethane double-napped microfiber leather, which is substantially the same as that of Example 1, except that in step (4), no temperature adjustment is performed and direct roller extrusion is performed, and the total thickness loss after extrusion is 40%.

[0071] The abrasion loss of the finally prepared water-based polyurethane double-napped microfiber leather is 32 mg.

[0072] Comparing Example 1 with Comparative Example 3, it can be seen that the abrasion loss of the high-wear-resistant water-based polyurethane double-napped microfiber leather prepared in Comparative Example 3 is greatly increased. This is because the intermediate product at high temperature does not have a hardening effect, and the intermediate product will collapse during extrusion without the support of hardening, thereby causing irreversible deformation and synchronous movement with the gelled water-based polyurethane, so that the gelled water-based polyurethane cannot be concentrated in the middle of the non-woven fabric. At the same time, part of the water-based polyurethane gel will be extruded out of the non-woven fabric under the action of the roller, thereby resulting in poor coating of the water-based polyurethane on the internal fibers. In addition, since the surface fibers of the non-woven fabric are wrapped by the polyurethane, it will also cause difficulty in raising during raising, fiber sparseness, poor napping and appearance.

[0073] Example 2

[0074] A preparation method of high-wear-resistant water-based polyurethane double-napped microfiber leather, the steps of which are as follows:

[0075] (1) Preparation of raw materials;

[0076] Island fiber non-woven fabric: LDPE / PA non-woven fabric (the mass ratio of LDPE and PA is 70:30), and the apparent density of the LDPE / PA non-woven fabric is 0.23 g / cm 3 ;

[0077] Water-based polyurethane slurry: prepared by jointly adjusting water-based polyurethane emulsion (manufacturer: Dow Chemical, brand: YS-3000, and the solid content of polyurethane resin in the emulsion is 54%) and a Na2SO4 aqueous solution with a mass concentration of 1.8 wt%; during the adjustment process, the Na2SO4 aqueous solution is added to the water-based polyurethane emulsion, until the solid content of polyurethane in the water-based polyurethane slurry reaches 23%, and the mass proportion of the Na2SO4 aqueous solution in the water-based polyurethane slurry is 57%;

[0078] (2) Immersion;

[0079] The island fiber non-woven fabric is immersed in the water-based polyurethane slurry, and the liquid retention rate is controlled to be 160%;

[0080] (3) Heat treatment;

[0081] The dipped island fiber nonwoven fabric is treated at a heat treatment temperature of 115°C to make the water-based polyurethane completely gelatinized to obtain an intermediate product, and the water evaporation degree in the heat treatment process is controlled to make the water content of the gelled water-based polyurethane in the intermediate product be 48%;

[0082] (4) roller extrusion treatment;

[0083] The temperature of the intermediate product is first adjusted to 22°C, and then the intermediate product is subjected to 4 times of roller extrusion on a roller with a pressure of 0.25 MPa, and the total thickness loss after the extrusion is 6%;

[0084] (5) drying and curing;

[0085] The intermediate product after the roller extrusion is dried at a temperature of 130°C to a water evaporation rate of 99.8%;

[0086] (6) fiber opening;

[0087] The fiber opening is performed by using a solvent capable of dissolving the nonwoven fabric sea material to obtain a superfine base cloth;

[0088] (7) napping;

[0089] The superfine base cloth is napped to obtain a high-wear-resistant water-based polyurethane double-napped superfine leather.

[0090] The wear amount of the finally prepared high-wear-resistant water-based polyurethane double-napped superfine leather is 11 mg.

[0091] Example 3

[0092] A preparation method of a high-wear-resistant water-based polyurethane double-napped superfine leather, comprising the following steps:

[0093] (1) raw material preparation;

[0094] Island fiber nonwoven fabric: LDPE / PA nonwoven fabric (the mass ratio of LDPE and PA is 70:30), and the apparent density of the LDPE / PA nonwoven fabric is 0.3 g / cm 3 ;

[0095] Water-based polyurethane slurry: prepared by mixing a water-based polyurethane emulsion (the manufacturer is Dow Chemical, the model is YS-3000, and the solid content of the polyurethane resin in the emulsion is 54%) and a NaCl aqueous solution with a mass concentration of 2.3 wt%, and in the mixing process, the NaCl aqueous solution is added to the water-based polyurethane emulsion until the solid content of the polyurethane in the water-based polyurethane slurry reaches 36%, and the mass ratio of the NaCl aqueous solution in the water-based polyurethane slurry is 33%;

[0096] (2) dipping;

[0097] The island fiber non-woven fabric is immersed in the water-based polyurethane slurry, and the liquid rate is controlled to be 240%;

[0098] (3) heat treatment;

[0099] The immersed island fiber non-woven fabric is treated at a heat treatment temperature of 90°C, so that the water-based polyurethane is completely gelled, an intermediate product is obtained, and the water content of the gelled water-based polyurethane in the intermediate product is controlled to be 52% by controlling the degree of water evaporation during the heat treatment process;

[0100] (4) roller extrusion treatment;

[0101] The temperature of the intermediate product is first adjusted to 26°C, and then the intermediate product is subjected to 5 times of roller extrusion on a roller with a pressure of 0.3 MPa, and the total thickness loss after extrusion is 7%;

[0102] (5) drying and curing;

[0103] The intermediate product after roller extrusion is dried at a temperature of 140°C until the water evaporation rate is 99.9%;

[0104] (6) fiber opening;

[0105] A solvent capable of dissolving the non-woven fabric sea material is used for fiber opening to obtain a super fiber base cloth;

[0106] (7) napping;

[0107] The super fiber base cloth is napped to obtain a high wear-resistant water-based polyurethane double-napped super fiber leather.

[0108] The abrasion loss of the finally prepared high wear-resistant water-based polyurethane double-napped super fiber leather is 4 mg.

[0109] Example 4

[0110] A method for preparing a high wear-resistant water-based polyurethane double-napped super fiber leather, comprising the following steps:

[0111] (1) raw material preparation;

[0112] Island fiber non-woven fabric: LDPE / PA non-woven fabric (the mass ratio of LDPE and PA is 70:30), and the apparent density of the LDPE / PA non-woven fabric is 0.38 g / cm 3 ;

[0113] The water-based polyurethane slurry was prepared by mixing the water-based polyurethane emulsion (the manufacturer was Dow Chemical, the model was YS-3000, and the solid content of the polyurethane resin in the emulsion was 54%) and the 1wt% NaCl aqueous solution. During the mixing process, the NaCl aqueous solution was added to the water-based polyurethane emulsion until the solid content of the polyurethane in the water-based polyurethane slurry reached 25%, and the mass ratio of the NaCl aqueous solution in the water-based polyurethane slurry was 54%;

[0114] (2) impregnation;

[0115] The island fiber non-woven fabric was impregnated in the water-based polyurethane slurry, and the liquid retention rate was controlled to be 200%;

[0116] (3) heat treatment;

[0117] The impregnated island fiber non-woven fabric was treated at a heat treatment temperature of 120°C to make the water-based polyurethane completely gel, and an intermediate product was obtained. The water content of the gelled water-based polyurethane in the intermediate product was controlled to be 65% by controlling the degree of water evaporation during the heat treatment process.

[0118] (4) roller extrusion treatment;

[0119] The temperature of the intermediate product was first adjusted to 23°C, and then the intermediate product was subjected to 3 times of roller extrusion on the roller with a pressure of 0.25MPa. The total thickness loss after the extrusion was 5%;

[0120] (5) drying and curing;

[0121] The intermediate product after the roller extrusion was dried at a temperature of 140°C until the water evaporation rate was 99.9%;

[0122] (6) fiber opening;

[0123] The solvent capable of dissolving the non-woven fabric marine material was used for fiber opening to obtain a super fiber base cloth;

[0124] (7) napping;

[0125] The super fiber base cloth was napped to obtain a high wear-resistant water-based polyurethane double-napped super fiber leather.

[0126] The abrasion loss of the finally prepared high wear-resistant water-based polyurethane double-napped super fiber leather was 8mg.

Claims

1. A method for preparing high wear resistant waterborne polyurethane double suede microfiber leather, characterized by The method comprises the following steps: (1) raw material preparation; The raw material of the high-wear-resistance water-based polyurethane double-napped microfiber leather comprises island fiber non-woven fabric and water-based polyurethane slurry; The density of the sea-island fiber nonwoven fabric is 0.23-0.38 g / cm 3 ; The water-based polyurethane slurry is composed of water-based polyurethane emulsion and electrolyte solution, so that the water-based polyurethane slurry has the property of thermal-induced gelation; The polyurethane solid content of the water-based polyurethane slurry is 23-36%; (2) impregnation; The island fiber non-woven fabric is impregnated in the water-based polyurethane slurry, and the liquid retention rate is controlled to be at least 160%; (3) heat treatment; The heat treatment is performed at a heat treatment temperature of 90-120 DEG C, so that the water-based polyurethane is completely gelled, and an intermediate product is obtained, and the water content of the gelled water-based polyurethane in the intermediate product is controlled to be greater than or equal to 48% by controlling the degree of water evaporation during the heat treatment; (4) roller extrusion treatment; Before the extrusion treatment, the temperature of the intermediate product is adjusted to reach the hardening temperature of the non-woven fabric in the intermediate product, and is higher than 20 DEG C; The hardening temperature is determined as follows: the temperature of the intermediate product after the heat treatment in step (3) is adjusted to a target temperature, and after the target roller extrusion process, the total thickness loss is not more than 7%, and the target temperature is considered as the hardening temperature of the intermediate product under the target roller process; The target roller pressure is 0.20-0.30 MPa; The intermediate product is subjected to the roller extrusion for 3-5 times; (5) drying and curing; The intermediate product after the roller extrusion is subjected to drying and curing; (6) fiber opening; A solvent capable of dissolving the non-woven fabric sea material is used for fiber opening, and a microfiber base fabric is obtained; (7) napping; The microfiber base fabric is subjected to napping, and a high-wear-resistance water-based polyurethane double-napped microfiber leather is obtained.

2. The preparation method of the high-wear-resistant waterborne polyurethane double-napped microfiber leather according to claim 1, characterized in that, In step (2), the liquid retention rate is controlled to be within 240%.

3. The preparation method of the high-wear-resistance waterborne polyurethane double-napped microfiber leather according to claim 1, characterized in that, In step (5), the drying and curing refers to drying at a temperature of 120-140 DEG C until the water content of the intermediate product is less than or equal to 0.02%.

4. The preparation method of the high-wear-resistance waterborne polyurethane double-napped microfiber leather according to any one of claims 1-3, characterized in that, The abrasion loss of the high-wear-resistance water-based polyurethane double-napped microfiber leather is 6-11 mg.