Preparation method of high-wear-resistance waterborne polyurethane double-suede microfiber leather

Abstract

The invention belongs to the technical field of waterborne polyurethane suede superfine fiber synthetic leather, and discloses a preparation method of high-wear-resistance waterborne polyurethane double-suede superfine fiber leather, which comprises the following steps: dipping a sea-island fiber non-woven fabric in waterborne polyurethane slurry, carrying out heat treatment on the dipped sea-island fiber non-woven fabric to obtain an intermediate product, and drying the intermediate product to obtain the high-wear-resistance waterborne polyurethane double-suede superfine fiber leather. Adjusting the temperature of the intermediate product to a proper temperature, carrying out roller extrusion on the intermediate product on a roller, drying and curing the intermediate product subjected to roller extrusion, splitting the cured intermediate product by adopting a solvent capable of dissolving and removing the non-woven fabric marine phase material to obtain microfiber base cloth, and finally raising the microfiber base cloth, so as to obtain the non-woven fabric marine phase material. The high-wear-resistance waterborne polyurethane double-suede microfiber leather is obtained. The waterborne polyurethane gathers in the middle of the non-woven fabric to form the substrate layer so as to tightly wrap the fibers, and the problem that the raising effect is affected due to accumulation of the waterborne polyurethane on the raising layer is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of waterborne polyurethane suede superfine fiber synthetic leather and relates to a preparation method of highly wear-resistant waterborne polyurethane double suede superfine fiber leather. Background Art

[0002] Polyurethane suede microfiber leather has been widely used as a high-quality substitute for suede suede leather due to its unique performance advantages. In the process of preparing polyurethane suede microfiber leather, traditional technology mostly uses solvent-based polyurethane. In the process of production using this process, when the solvent-based polyurethane is impregnated, it will fill the space between the fibers in the non-woven fabric, and solidify the polyurethane through the replacement of DMF and water, and finally form a continuous polyurethane resin structure that is tightly wrapped around the fibers.

[0003] However, with the improvement of environmental awareness and the emphasis on safe production, water-based polyurethane has been increasingly valued in the microfiber leather industry due to its safer, more reliable and green characteristics. However, after water-based polyurethane is impregnated into non-woven fabrics, during the heating and curing process, the particles will move and accumulate with the evaporation of water, and will adhere and solidify unevenly on the fiber surface. The formed resin film is discontinuous, and the fiber coating is poor, resulting in weak fiber grip, insufficient wear resistance, and easy hair loss.

[0004] In order to solve the above problems, there are currently two common methods for water-based polyurethane suede. One 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 split it into two by a skinning process to serve as the suede raising layer. However, although this method has a good raising effect, it destroys the fiber structure in the non-woven fabric, resulting in reduced mechanical properties of the finished product, and cannot solve the problem of discontinuous water-based polyurethane resin film and poor fiber coating.

[0005] Another method is to control the directional movement and accumulation of waterborne polyurethane toward one side of the non-woven fabric, and use the fiber layer on the resin-free side as the nap layer. However, this method also fails to avoid the problem of uneven accumulation of waterborne polyurethane in the non-woven fabric, so the coating effect on the fiber is still not ideal.

[0006] Patent CN115613371A discloses a method for preparing a highly wear-resistant waterborne polyurethane microfiber base fabric, which mainly improves the Martin wear resistance of the waterborne polyurethane base fabric by using water-soluble polyester as the sea-island fiber of the sea phase and the waterborne polyurethane double impregnation curing process. This method is targeted at specific sea-island fibers and has a narrow scope of application. At the same time, this method fails to solve the problem of accumulation and entanglement of waterborne polyurethane between the fibers of the surface layer of the non-woven fabric. The velvet layer of the finished product is mainly formed by the fibers that tend to stand upright in the non-woven fabric on the surface of the non-woven fabric. The velvet feel of the product is not dense, and the double impregnation curing process has high requirements for the control of equipment and process, and the processing cost is also high.

[0007] Therefore, a method for preparing a highly wear-resistant water-based polyurethane double-suede microfiber leather is needed to solve the above problems, which is of great significance. Summary of the invention

[0008] The purpose of the invention is to solve the problems existing in the prior art and to provide a method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather comprises the following steps:

[0011] (1) Raw material preparation;

[0012] The raw materials of the highly wear-resistant water-based polyurethane double-suede microfiber leather include sea-island fiber non-woven fabric and water-based polyurethane slurry;

[0013] The density of the sea-island fiber nonwoven fabric is 0.23-0.38 g / cm 3 ; The density is too low, and the distance between the non-woven fabric fibers is too far, so more water-based polyurethane needs to be filled to cover the fibers, which is costly and the finished product feels harder than a board; The apparent density of the non-woven fabric is too high, and the fibers are tightly packed, which is not conducive to the water-based polyurethane gel being squeezed into the middle part of the non-woven fabric to form a base layer to achieve tight coverage of the fibers;

[0014] The aqueous polyurethane slurry is composed of an aqueous polyurethane emulsion and an electrolyte aqueous solution, so that the aqueous polyurethane slurry has the property of thermo-induced gelation; for example, if an electrolyte aqueous solution with a mass concentration of 0.7-2.3% is added to the aqueous polyurethane emulsion, and the mass proportion of the electrolyte aqueous solution in the aqueous polyurethane slurry is 33-57wt%, the prepared aqueous polyurethane slurry can have the property of thermo-induced gelation, so that the aqueous polyurethane slurry can be changed from liquid to gel, and the gel-state aqueous polyurethane will not migrate with the volatilization of water, but will gather in the middle part of the non-woven fabric under the extrusion of the roller, so that the water evaporates and accumulates in the middle part of the non-woven fabric during subsequent drying and curing; if the mass proportion of the electrolyte aqueous solution in the aqueous polyurethane slurry is too low, gelation cannot occur, and if the proportion is too high, the aqueous polyurethane emulsion will be demulsified; the electrolyte is, for example, common Na2SO4, NaCl, KCl, K2SO4, etc.;

[0015] (2) Impregnation;

[0016] The sea-island fiber nonwoven fabric is immersed in the aqueous polyurethane slurry, and the liquid carrying rate is controlled to be at least 160%; the slurry immersed in the nonwoven fabric is distributed in the nonwoven fabric in the following step (4), and if the liquid carrying rate is lower than 160%, it is difficult to achieve an ideal coating effect no matter how the extrusion strength is adjusted because the liquid carrying rate is too low;

[0017] (3) Heat treatment;

[0018] Treating the waterborne polyurethane at a heat treatment temperature of 90 to 120° C. to completely gelate the waterborne polyurethane to obtain an intermediate product, and controlling the degree of water volatilization during the heat treatment process to ensure that the water content of the gelled waterborne 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. There is part of the liquid slurry inside the non-woven fabric, which will be absorbed to the surface of the non-woven fabric and entangled with the fibers during the roller extrusion process, affecting the napping. If the heat treatment temperature is too high, the polyurethane gel near the surface of the non-woven fabric will be severely cross-linked and cured when the polyurethane slurry is completely gelled, and even film-formed. During the roller extrusion process, it cannot be squeezed into the non-woven fabric and remains on the surface of the non-woven fabric, affecting the napping.

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

[0021] (4) Roller extrusion treatment;

[0022] Before 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 extrusion difficulties; the hardening temperature is determined according to the following method: the intermediate after heat treatment in the sampling step (3) is adjusted to the target temperature, and after extrusion by the target roller extrusion process, the total thickness loss does not exceed 7%, that is, the temperature is considered to be the hardening temperature of the intermediate under the target roller process; for example, the sea island fiber LDPE / PA is lower than 70°C, LDPE / PET is lower than 75°C, COPET / PA is lower than 125°C, COPET / PET is lower than 130°C, SWPET / PA is lower than 70°C, and SWPET / PET is lower than 75°C. The intermediate product in step (3) has a hardening effect, and the specific value may deviate from the raw materials and process, and can be determined according to this method;

[0023] The target roller pressure is 0.20-0.30 MPa. When the upper and lower rollers are squeezed, the squeezing effect is too weak, and the water-based polyurethane gel moves weakly into the non-woven fabric, resulting in a certain amount of surface fleece layer fibers being wrapped by polyurethane and the fleece layer being thin, resulting in poor fleece effect. If the squeezing effect is too strong, the polyurethane gel will be squeezed out of the non-woven fabric, resulting in the polyurethane gel being mainly concentrated in the middle narrow part, the base layer being thin, and the fiber coating effect being weak.

[0024] The intermediate product is subjected to roller extrusion for 3 to 5 times. If the number of times is less than 3 times, the resin is not sufficiently gathered in the middle part of the non-woven fabric, and the fiber coating cannot be fully wrapped; if the number of times is more than 5 times, it is difficult to obtain a curing temperature that meets the requirements;

[0025] (5) drying and curing;

[0026] The intermediate product after roller extrusion is dried and solidified; after drying and solidification, the water-based polyurethane gathers in the middle part of the non-woven fabric and tightly covers the fibers to form a base layer, and the surface layer without polyurethane distribution is a fleece layer;

[0027] (6) Fiber opening;

[0028] A solvent capable of dissolving the sea phase material of the non-woven fabric is used for fiber opening to obtain an ultra-fine fiber base fabric; the solvent used for fiber opening is selected according to the existing technology, such as toluene reduction for LDPE, alkali reduction for COPET, and water reduction for SWPET (water-soluble polyester);

[0029] (7) raising;

[0030] The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0031] As the preferred technical solution:

[0032] In the method for preparing a highly wear-resistant water-based polyurethane double-suede microfiber leather as described above, the water-based polyurethane slurry in step (1) has a polyurethane solid content of 23-36%. The slurry preferably controls the polyurethane solid content to be 23-36%, and the gel-state water-based polyurethane water accumulated in the middle part of the non-woven fabric forms gaps after evaporation, giving the base fabric a soft feel. If the solid content is too low, the gaps are too large, and the fabric feels hollow and soft; if the solid content is too high, the gaps are smaller, and the fabric feels hollow and hard.

[0033] In the method for preparing a highly wear-resistant water-based polyurethane double-suede microfiber leather as described above, the liquid carrying rate is controlled within 240% in step (2), and a liquid carrying rate that is too high will be squeezed out in step (4).

[0034] In the method for preparing a highly wear-resistant water-based polyurethane double-suede microfiber leather as described above, the drying and curing in step (5) refers to drying at a temperature of 120-140° C. until the moisture content of the intermediate product is ≤0.02%, that is, the moisture volatilization rate is ≥99.8%.

[0035] A method for preparing a highly wear-resistant water-based polyurethane double-suede microfiber leather as described in any of the above items, wherein the wear loss of the highly wear-resistant water-based polyurethane double-suede microfiber leather is 6 to 11 mg.

[0036] Beneficial effects:

[0037] The present invention adopts a density of 0.23 to 0.38 g / cm 3 The sea-island fiber non-woven fabric and the electrolyte solution are added to the water-based polyurethane slurry to make it have the property of thermo-gelling, so that the gel-state water-based polyurethane gathers in the middle part of the non-woven fabric under the extrusion of the roller to form a base layer to achieve tight coating of the fibers, and because the gel-state water-based polyurethane will not migrate with the evaporation of water, the evaporation of water will only accumulate in the middle part of the non-woven fabric during the subsequent drying and curing, thereby avoiding the problem of the accumulation of water-based polyurethane in the raising layer affecting the raising effect. DETAILED DESCRIPTION

[0038] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0039] In order to ensure that the properties of the materials used in the embodiments and comparative examples are fully disclosed, the manufacturers and brands of some materials are specified, and products of other manufacturers and brands that meet the requirements of the present invention are also feasible.

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

[0041] Abrasion loss: The highly wear-resistant water-based polyurethane double-suede microfiber leather prepared in each embodiment and the water-based polyurethane double-suede microfiber leather prepared in each comparative example are used as samples, and then the mass loss after rubbing the samples 35,000 times is tested according to GB / T 21196.3-2007 standard, which is the abrasion loss.

[0042] The fiber opening and raising described in the following embodiments and comparative examples are conventional technologies in the field. The solvent used in fiber opening can be selected according to the components in the sea island fiber non-woven fabric, such as toluene reduction for LDPE, alkali reduction for COPET, and water reduction for SWPET; the raising is performed by using a grinding roller, and after fiber opening, the surface layer of the microfiber base cloth is repeatedly polished with sandpaper to form a velvet layer. This process is to break up the fibers of the velvet layer after the fibers are completely opened, and grind the surface to present the texture of suede. The process used for raising the velvet is a conventional process, and technicians in this field can make corresponding adjustments according to needs.

[0043] Example 1

[0044] A method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather, comprising the following steps:

[0045] (1) Raw material preparation;

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

[0047] Waterborne polyurethane slurry: It is prepared by mixing waterborne polyurethane emulsion (producer: Dow Chemical, brand: YS-3000, solid content of polyurethane resin in the emulsion: 54%) and Na2SO4 aqueous solution with a mass concentration of 0.7wt%. During the mixing 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) Impregnation;

[0049] The sea-island fiber nonwoven fabric was immersed in the aqueous polyurethane slurry, and the liquid carrying rate was controlled to be 210%;

[0050] (3) Heat treatment;

[0051] The impregnated sea-island fiber nonwoven fabric is treated at a heat treatment temperature of 105° C. to completely gel the water-based polyurethane to obtain an intermediate product, and the degree of water volatilization during the heat treatment process is controlled so that the water content of the gelled water-based polyurethane in the intermediate product is 60%;

[0052] (4) Roller extrusion treatment;

[0053] First, the temperature of the intermediate product is adjusted to 25°C, and then the intermediate product is rolled three times on a roller with a pressure of 0.2MPa. The total thickness loss after rolling is 5%.

[0054] (5) drying and curing;

[0055] The intermediate product after roller extrusion is dried at 120°C until the moisture volatilization rate is 99.8%;

[0056] (6) Fiber opening;

[0057] A solvent capable of dissolving the sea-phase material of the non-woven fabric is used to open the fibers to obtain an ultra-fine fiber base fabric;

[0058] (7) raising;

[0059] The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0060] The wear loss of the highly wear-resistant water-based polyurethane double-suede microfiber leather finally obtained is 6 mg.

[0061] Comparative Example 1

[0062] A method for preparing waterborne polyurethane double suede microfiber leather is basically the same as that in Example 1, except that the liquid carrying rate in step (2) is controlled to be 140%.

[0063] The wear loss of the finally prepared waterborne polyurethane double suede microfiber leather was 27 mg.

[0064] By comparing Comparative Example 1 and Example 1, it can be seen that the wear amount of the water-based polyurethane double-suede microfiber leather prepared in Comparative Example 1 is larger. This is because when the liquid carrying rate is too low, the polyurethane slurry is insufficiently filled in the fiber gaps, and it is difficult to achieve the ideal coating effect, resulting in reduced wear resistance of the water-based polyurethane double-suede microfiber leather.

[0065] Comparative Example 2

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

[0067] The wear loss of the finally prepared waterborne polyurethane double suede microfiber leather was 18 mg.

[0068] By comparing Comparative Example 2 with Example 1, it can be seen that the high wear-resistant water-based polyurethane double-suede microfiber leather prepared in Comparative Example 2 has a larger wear amount. This is because when the water content of the gelled water-based polyurethane is too low, the polyurethane slurry gel solidifies severely and has hardened during roller extrusion. The water-based polyurethane gel cannot be squeezed by the roller to gather in the middle part of the non-woven fabric, resulting in poor fiber coating effect of the polyurethane slurry and reduced wear resistance. At the same time, it will also cause the surface fibers to be wrapped by the polyurethane, making it difficult to raise the nap, resulting in sparse fibers and poor velvet feel and appearance.

[0069] Comparative Example 3

[0070] A method for preparing waterborne polyurethane double suede microfiber leather is basically the same as that in Example 1, except that: in step (4), the temperature is not adjusted and roller extrusion is directly performed, and the total thickness loss after extrusion is 40%.

[0071] The wear loss of the finally prepared waterborne polyurethane double suede microfiber leather is 32 mg.

[0072] By comparing Comparative Example 3 with Example 1, it can be seen that the wear amount of the highly wear-resistant water-based polyurethane double-suede 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. When extruded, the intermediate product will collapse and have no hardening support, thereby producing irreversible deformation and moving synchronously with the gelled water-based polyurethane, making it impossible for the gelled water-based polyurethane to be concentrated in the middle of the non-woven fabric. At the same time, under the extrusion of the roller, part of the water-based polyurethane gel will also be squeezed out of the non-woven fabric, resulting in poor internal fiber coating by the water-based polyurethane; in addition, since the surface fibers of the non-woven fabric are wrapped by polyurethane, it will also cause difficulty in raising the nap, the fibers are sparse, and the nap feeling and appearance are poor.

[0073] Example 2

[0074] A method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather, comprising the following steps:

[0075] (1) Raw material preparation;

[0076] Sea island fiber nonwoven fabric: LDPE / PA nonwoven fabric (the mass ratio of LDPE and PA is 70:30), the apparent density of LDPE / PA nonwoven fabric is 0.23g / cm 3 ;

[0077] Waterborne polyurethane slurry: prepared by mixing waterborne polyurethane emulsion (producer: Dow Chemical, brand: YS-3000, solid content of polyurethane resin in the emulsion: 54%) and Na2SO4 aqueous solution with a mass concentration of 1.8wt%. During the mixing process, Na2SO4 aqueous solution is added to the waterborne polyurethane emulsion until the solid content of polyurethane in the waterborne polyurethane slurry reaches 23%, and the mass proportion of Na2SO4 aqueous solution in the waterborne polyurethane slurry is 57%;

[0078] (2) Impregnation;

[0079] The sea-island fiber nonwoven fabric is immersed in the aqueous polyurethane slurry, and the liquid carrying rate is controlled to be 160%;

[0080] (3) Heat treatment;

[0081] The impregnated sea-island fiber nonwoven fabric is treated at a heat treatment temperature of 115° C. to completely gel the water-based polyurethane to obtain an intermediate product, and the degree of water volatilization during the heat treatment process is controlled so that the water content of the gelled water-based polyurethane in the intermediate product is 48%;

[0082] (4) Roller extrusion treatment;

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

[0084] (5) drying and curing;

[0085] The intermediate product after roller extrusion is dried at 130°C until the moisture volatilization rate is 99.8%;

[0086] (6) Fiber opening;

[0087] A solvent capable of dissolving the sea-phase material of the non-woven fabric is used to open the fibers to obtain an ultra-fine fiber base fabric;

[0088] (7) raising;

[0089] The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0090] The wear loss of the highly wear-resistant water-based polyurethane double-suede microfiber leather finally obtained is 11 mg.

[0091] Example 3

[0092] A method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather, comprising the following steps:

[0093] (1) Raw material preparation;

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

[0095] Waterborne polyurethane slurry: prepared by mixing waterborne polyurethane emulsion (producer: Dow Chemical, brand: YS-3000, polyurethane resin solid content in the emulsion: 54%) and NaCl aqueous solution with a mass concentration of 2.3wt%. During the mixing process, NaCl aqueous solution is added to the waterborne polyurethane emulsion until the polyurethane solid content in the waterborne polyurethane slurry reaches 36%, and the mass proportion of NaCl aqueous solution in the waterborne polyurethane slurry is 33%;

[0096] (2) Impregnation;

[0097] The sea-island fiber nonwoven fabric was immersed in the aqueous polyurethane slurry, and the liquid carrying rate was controlled to be 240%;

[0098] (3) Heat treatment;

[0099] The impregnated sea-island fiber nonwoven fabric is treated at a heat treatment temperature of 90° C. to completely gel the water-based polyurethane to obtain an intermediate product, and the degree of water volatilization during the heat treatment process is controlled so that the water content of the gelled water-based polyurethane in the intermediate product is 52%;

[0100] (4) Roller extrusion treatment;

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

[0102] (5) drying and curing;

[0103] The intermediate product after roller extrusion is dried at 140°C until the moisture volatilization rate is 99.9%;

[0104] (6) Fiber opening;

[0105] A solvent capable of dissolving the sea-phase material of the non-woven fabric is used to open the fibers to obtain an ultra-fine fiber base fabric;

[0106] (7) raising;

[0107] The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0108] The wear loss of the highly wear-resistant water-based polyurethane double-suede microfiber leather finally obtained is 4 mg.

[0109] Example 4

[0110] A method for preparing highly wear-resistant water-based polyurethane double-suede microfiber leather, comprising the following steps:

[0111] (1) Raw material preparation;

[0112] Sea island fiber nonwoven fabric: LDPE / PA nonwoven fabric (the mass ratio of LDPE and PA is 70:30), the apparent density of LDPE / PA nonwoven fabric is 0.38g / cm 3 ;

[0113] Waterborne polyurethane slurry: prepared by mixing waterborne polyurethane emulsion (producer: Dow Chemical, brand: YS-3000, solid content of polyurethane resin in the emulsion: 54%) and NaCl aqueous solution with a mass concentration of 1wt%. During the mixing process, NaCl aqueous solution is added to the waterborne polyurethane emulsion until the solid content of polyurethane in the waterborne polyurethane slurry reaches 25%, and the mass proportion of NaCl aqueous solution in the waterborne polyurethane slurry is 54%;

[0114] (2) Impregnation;

[0115] The sea island fiber nonwoven fabric is immersed in the aqueous polyurethane slurry, and the liquid carrying rate is controlled to be 200%;

[0116] (3) Heat treatment;

[0117] The impregnated sea-island fiber nonwoven fabric is treated at a heat treatment temperature of 120° C. to completely gel the water-based polyurethane to obtain an intermediate product, and the degree of water volatilization during the heat treatment process is controlled so that the water content of the gelled water-based polyurethane in the intermediate product is 65%;

[0118] (4) Roller extrusion treatment;

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

[0120] (5) drying and curing;

[0121] The intermediate product after roller extrusion is dried at 140°C until the moisture volatilization rate is 99.9%;

[0122] (6) Fiber opening;

[0123] A solvent capable of dissolving the sea-phase material of the non-woven fabric is used to open the fibers to obtain an ultra-fine fiber base fabric;

[0124] (7) raising;

[0125] The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

[0126] The wear loss of the highly wear-resistant water-based polyurethane double-suede microfiber leather finally obtained is 8 mg.

Claims

1. A method for preparing highly wear-resistant waterborne polyurethane double suede microfiber leather, characterized in that The following steps are involved: (1) Raw material preparation; The raw materials of the highly wear-resistant water-based polyurethane double-suede microfiber leather include sea-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 aqueous polyurethane slurry is composed of aqueous polyurethane emulsion and electrolyte solution; (2) Impregnation; The sea-island fiber nonwoven fabric is immersed in the aqueous polyurethane slurry, and the liquid carrying rate is controlled to be at least 160%; (3) Heat treatment; Treating the waterborne polyurethane at a heat treatment temperature of 90 to 120° C. to completely gelate the waterborne polyurethane to obtain an intermediate product, and controlling the degree of water volatilization during the heat treatment process to ensure that the water content of the gelled waterborne polyurethane in the intermediate product is ≥48%; (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° C.; The target roll pressure is 0.20-0.30 MPa; Rolling the intermediate product 3 to 5 times; (5) drying and curing; Drying and curing the intermediate product after roller extrusion; (6) Fiber opening; A solvent capable of dissolving the sea-phase material of the non-woven fabric is used to open the fibers to obtain an ultra-fine fiber base fabric; (7) raising; The microfiber base fabric is raised to obtain highly wear-resistant water-based polyurethane double-suede microfiber leather.

2. The method for preparing a highly wear-resistant waterborne polyurethane double suede microfiber leather according to claim 1, characterized in that: The polyurethane solid content of the aqueous polyurethane slurry in step (1) is 23-36%.

3. The method for preparing a highly wear-resistant waterborne polyurethane double suede microfiber leather according to claim 1, characterized in that: In step (2), the liquid carrying rate is controlled within 240%.

4. The method for preparing a highly wear-resistant waterborne polyurethane double suede microfiber leather according to claim 1, characterized in that: The drying and curing in step (5) refers to drying at a temperature of 120-140° C. until the moisture content of the intermediate product is ≤0.02%.

5. The method for preparing a highly wear-resistant waterborne polyurethane double suede microfiber leather according to any one of claims 1 to 4, characterized in that: The wear loss of highly wear-resistant water-based polyurethane double suede microfiber leather is 6 to 11 mg.