Preparation method of sandwich rainbow structure water-based leather base cloth

Abstract

The application provides a preparation method of sandwich rainbow structure water-based leather base cloth, comprising the following steps: sandwich sandwich non-woven fabric is prepared through needle punching composite process, and the thickness and gram weight of the sandwich sandwich non-woven fabric are shaped; the sandwich sandwich non-woven fabric comprises an upper random island and sea fiber layer, a polyester mesh layer and a lower random island and sea fiber layer from top to bottom; the sandwich sandwich non-woven fabric is sequentially subjected to impregnation of water-based polyurethane slurry, coagulation drying, toluene reduction, oiling, skin rubbing, skin grinding and dyeing and finishing process of acidic dyeing liquid, and the required sandwich rainbow structure water-based leather base cloth is obtained. The prepared sandwich rainbow structure water-based leather base cloth has bright cross-section color and complete sense of level, can meet market demand and has the advantages of high mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of synthetic leather, in particular to a preparation method of sandwich rainbow structure water-based microfiber leather base cloth. BACKGROUND

[0002] Water-based microfiber synthetic leather is a kind of leather product developed from microfiber synthetic leather. It is prepared through a series of processes such as needling, heat setting, impregnation, toluene reduction, oiling, kneading, buffing, dyeing, etc. to obtain a microfiber leather base cloth, and then the microfiber leather base cloth is subjected to a lamination process to obtain a finished water-based microfiber synthetic leather. It has the characteristics of soft and elastic hand feeling and green environmental protection. With the rapid development of economy, a variety of synthetic leather products have emerged in an endless stream. People often pay more attention to products with unique and novel style, bright colors, and health and environmental protection.

[0003] Due to the process requirements of water-based microfiber synthetic leather, no harmful substances such as DMF are added during the processing, and under the halo of green environmental protection, the conventional water-based microfiber synthetic leather still has the defects of low tensile strength and poor tear resistance. In addition, the high fastness dyeing process deepens these defects. Therefore, it is also a challenge to produce a water-based product with bright color, high color fastness and high physical properties.

[0004] In view of this, the present inventors have conducted in-depth research on the above problems, and thus the present application is produced. SUMMARY

[0005] The present application provides a preparation method of sandwich rainbow structure water-based microfiber leather base cloth. The cross-section of the prepared sandwich rainbow structure water-based microfiber leather base cloth is bright in color and has a full sense of hierarchy, which can meet the market demand. The sandwich rainbow structure water-based microfiber leather base cloth has the advantage of high mechanical properties.

[0006] The present application is implemented as follows: a preparation method of sandwich rainbow structure water-based microfiber leather base cloth, comprising the following steps:

[0007] Step one: a sandwich core non-woven fabric is prepared by needling composite process, and the thickness and grammage of the sandwich core non-woven fabric are set; the sandwich core non-woven fabric comprises an upper random island and sea fiber layer, a polyester mesh layer, and a lower random island and sea fiber layer from top to bottom;

[0008] Step two: the sandwich core non-woven fabric is sequentially subjected to impregnation of water-based polyurethane slurry, coagulation drying, toluene reduction, oiling, kneading, buffing, and dyeing with acid dye liquor, to obtain the required sandwich rainbow structure water-based microfiber leather base cloth.

[0009] Further, the upper and lower island-in-sea fiber layers are made of non-woven fabric prepared by mixing 45%-55% PA chip as island phase and 45%-55% PE chip as sea phase and using needle punching process.

[0010] Further, the upper and lower island-in-sea fiber layers have a grammage of 180-250 g / m 2 and a needle punching thickness of 1.2-1.5 mm; the polyester mesh layer has a grammage of 70-100 g / m 2 and a needle punching thickness of 0.6-0.8 mm.

[0011] Further, the needle punching process in step one is a two-time needle punching process, in which the polyester mesh layer is placed below the upper island-in-sea fiber layer, and the two layers are cross-linked by the set needle punching process to obtain a non-woven fabric with the upper island-in-sea fiber layer and the polyester mesh layer compounded; then the lower island-in-sea fiber layer is placed below the compounded polyester mesh layer, and the two layers are cross-linked by the set needle punching process to obtain a sandwich non-woven fabric; the needle punching process uses R-100 single-hook needles; the needle punching density in the needle punching process is 1500-1850 C / cm 2 .

[0012] Further, in the dyeing and finishing process in step two, the sanded sandwich leather base cloth is dyed and finished using an acid dyeing solution based on the characteristic that polyester does not adhere to acid dyeing solution; the acid dyeing solution comprises 5-10% organic sulfonate dye, 1-3% acetic acid, 0.2-0.5% amine compound leveling agent, 2-4% color fixing agent, and 82.5-91.8% water.

[0013] Further, the dyeing and finishing process comprises the following steps: the sanded sandwich leather base cloth is dyed in an acid dyeing solution at room temperature for 65-130 min, the dyeing is heated to 70-105℃ at a rate of 2℃ / min and kept for 30-40 min after the dyeing is complete, the temperature is lowered to 55℃, the leather base cloth is washed for 2-3 times, the color fixing is heated to 70-105℃ at a rate of 2℃ / min and kept for 30-40 min, the temperature is lowered to room temperature, the leather base cloth is washed for 2-3 times, and a sandwich rainbow structure water-based leather base cloth is obtained.

[0014] Further, in the impregnation of water-based polyurethane sizing paste process in step two, the impregnation paste preparation process is as follows: 100 parts of water-based polyurethane, 0.5-1.5 parts of polyurethane thickening agent, and 50-80 parts of pure water are added to a reaction kettle for stirring, the stirring speed of the stirrer is 2200-3800 r / min, the stirring time is 30-40 min, and the viscosity is controlled at 1800-2500 cps.

[0015] Further, in the toluene reduction process of step two, there are a total of 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86 DEG C, and tanks 8-10 are water washing tanks with a temperature of 99-101 DEG C; the vehicle speed is 7.5-9.5 m / min, and the opened island sandwich super-fiber base fabric is prepared.

[0016] The preparation method of the sandwich rainbow structure water-based leather base fabric has the following advantages: the sandwich core non-woven fabric has a three-layer structure, and the tensile strength and tear resistance are greatly improved, and the sandwich core non-woven fabric has high mechanical properties; the polyester mesh fabric is used as the core layer of the non-woven fabric, and based on the characteristic that the polyester material does not adhere to the acid dye, the color of the polyester mesh fabric layer after dyeing and finishing is different from that of the upper and lower island-sea fiber layers, the cross section of the leather base fabric forms a sandwich structure, the cross section has bright colors and clear levels, and the leather base fabric can be applied to prepare sofa leather, furniture leather, luggage leather, shoe leather and the like, and meet the market needs.

DETAILED DESCRIPTION

[0017] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0018] The present application provides a preparation method of a sandwich rainbow structure water-based leather base fabric, comprising the following steps:

[0019] Step one: a sandwich core non-woven fabric is prepared by a needle punching composite process, and the thickness and gram weight of the sandwich core non-woven fabric are determined; the sandwich core non-woven fabric comprises, from top to bottom, an upper island-sea fiber layer, a polyester mesh fabric layer and a lower island-sea fiber layer; the polyester mesh fabric layer is a colored polyester mesh fabric layer, and the color thereof can be arbitrarily selected according to actual needs.

[0020] Step two: the sandwich core non-woven fabric sequentially passes through impregnation of water-based polyurethane slurry, coagulation drying, toluene reduction, oiling, skin rubbing, skin grinding and acid dyeing and finishing processes to obtain the required sandwich rainbow structure water-based leather base fabric.

[0021] Step three: the sandwich rainbow structure water-based leather base fabric is subjected to dry lamination to obtain a sandwich rainbow structure rainbow water-based super-fiber synthetic leather.

[0022] In the preparation method of the sandwich rainbow structure water-based leather base fabric, the sandwich core non-woven fabric has a three-layer structure, and the tensile strength and tear resistance are greatly improved, and the sandwich core non-woven fabric has high mechanical properties; the polyester mesh fabric is used as the core layer of the non-woven fabric, and based on the characteristic that the polyester material does not adhere to the acid dye, the color of the polyester mesh fabric layer after dyeing and finishing is different from that of the upper and lower island-sea fiber layers, the cross section of the leather base fabric forms a sandwich structure, the cross section has bright colors and clear levels, and the leather base fabric can be applied to prepare sofa leather, furniture leather, luggage leather, shoe leather and the like, and meet the market needs.

[0023] In step one, the upper and lower indefinite island-sea fiber layers are first made into indefinite island fibers by mixing 45%-55% PA chips as island phase and 45%-55% PE chips as sea phase, and then made into non-woven fabric by needle punching process.

[0024] In step one, the upper and lower indefinite island-sea fiber layers have a grammage of 180-250 g / m 2 , and a needle punching thickness of 1.2-1.5 mm; the polyester mesh layer has a grammage of 70-100 g / m 2 , and a needle punching thickness of 0.6-0.8 mm.

[0025] In step one, the sandwich non-woven fabric is heated by a 7-stage oven with the temperature set at 90℃, 95℃, 115℃, 125℃, 135℃, 135℃ and 140℃ respectively, and the production speed is controlled at 7.5 m / min. The sandwich non-woven fabric after heat setting is cooled by a cooling roller with a temperature of 5-15℃, so as to realize the setting of the thickness and grammage of the sandwich non-woven fabric.

[0026] In step one, the needle punching composite process is a two-time needle punching composite process. The polyester mesh layer is placed below the upper indefinite island-sea fiber layer, and then needle punched and cross-linked according to the set needle punching process, so as to obtain the non-woven fabric with the upper indefinite island-sea fiber layer and the polyester mesh layer compounded; then the lower indefinite island-sea fiber layer is placed below the compounded polyester mesh layer, and then needle punched and cross-linked according to the set needle punching process, so as to obtain the sandwich non-woven fabric; the needle punching process uses R-100 single-hook needle; the needle punching density in the needle punching process is 1500-1850 C / cm 2 . Preferably, the needle punching density is 1680 C / cm

[0027] In step two, based on the characteristic that the polyester does not adhere to the acid dyeing liquid, the sandwich leather base fabric after buffing is dyed and finished by using acid dyeing liquid; the acid dyeing liquid comprises: organic sulfonate dye 5-10%, acetic acid 1-3%, amine compound leveling agent 0.2-0.5%, fixing agent 2-4%, and water 82.5-91.8%.

[0028] Preferably, the organic sulfonate dye is Meilan Red HDG type organic sulfonate dye produced by Shanghai Xingkang Chemical Co., Ltd.

[0029] Preferably, the fixing agent is a polyester acid fixing agent, and is Clausfix HF type polyester acid fixing agent produced by Shanghai Xingkang Chemical Co., Ltd.

[0030] Preferably, the amine compound leveling agent is Clauscolor B type amine compound leveling agent produced by Shanghai Xingkang Chemical Co., Ltd.

[0031] The dyeing and finishing process includes the following steps: the sanding leather base cloth is put into an acidic dyeing solution for dyeing at room temperature for 65-130 min, after dyeing, the temperature is increased to 70-105℃ at a rate of 2℃ / min and kept for 30-40 min, the temperature is decreased to 55℃, washed with water for 2-3 times, the temperature is increased to 70-105℃ at a rate of 2℃ / min and kept for 30-40 min, the temperature is decreased to room temperature, and washed with water for 2-3 times, thereby obtaining a sandwich rainbow structure water-based fiber leather base cloth. The temperature increase is helpful for the adsorption of the dye on the leather material and the color fixation; the temperature decrease is because the high washing temperature will affect the dyeing effect and part of the dye and the fixing agent will be separated. The two temperature increases, temperature decreases and washing operations in the dyeing and finishing process are helpful for improving the dyeing and finishing effect and quality.

[0032] In step two, the impregnation water-based polyurethane sizing process includes the following steps: 100 parts of water-based polyurethane, 0.5-1.5 parts of polyurethane thickening agent and 50-80 parts of pure water are added into a reaction kettle for stirring, the stirring speed is 2200-3800 r / min, the stirring time is 30-40 min, and the viscosity is controlled to be 1800-2500 cps.

[0033] Preferably, the polyurethane thickening agent is S-54 polyurethane thickening agent produced by Zhejiang Hongdeli New Material Co., Ltd.

[0034] In step two, after impregnation, the coagulation and drying process is carried out, and a 9-stage oven gradient heating drying is adopted, the temperatures are set to be 85-90℃, 95-100℃, 105-110℃, 110-115℃, 115-120℃, 125-130℃, 125-130℃, 135-140℃ and 135-140℃ respectively, and the vehicle speed is 7-9 m / min.

[0035] In step two, in the toluene reduction process, there are 10 tanks, the toluene tanks 1-7 have a temperature of 83-86℃, and the washing tanks 8-10 have a temperature of 99-101℃; the vehicle speed is 7.5-9.5 m / min, thereby obtaining the split sandwich super fiber base cloth with indefinite islands.

[0036] The beneficial effects of the sandwich rainbow structure water-based super fiber synthetic leather prepared by the preparation method of the present application are described below through several experimental groups and comparison groups.

[0037] Experimental group 1

[0038] A preparation method of a sandwich rainbow structure water-based fiber leather base cloth includes the following steps:

[0039] Step 1: using 55% PA chip as island phase and 45% PE chip as sea phase to blend the indefinite island fiber, and using needle punching process to prepare a non-woven fabric; a sandwich non-woven fabric is prepared by needle punching composite process, and the thickness and grammage of the sandwich non-woven fabric are fixed; the sandwich non-woven fabric comprises, from top to bottom, an upper indefinite island and sea fiber layer, a polyester mesh layer, and a lower indefinite island and sea fiber layer;

[0040] The needle punching composite process is a secondary needle punching composite process. The yellow polyester mesh layer is placed below the upper indefinite island and sea fiber layer, and is crosslinked by needle punching according to the set needle punching process, and the non-woven fabric with the upper indefinite island and sea fiber layer and the yellow polyester mesh layer is obtained by winding. The lower indefinite island and sea fiber layer is placed below the combined yellow polyester mesh layer, and is crosslinked by needle punching according to the set needle punching process, and the sandwich non-woven fabric is obtained. The needle is a single hook R-100 type during the needle punching process, and the needle density is 1680C / cm 2 ;

[0041] Step 2: the sandwich non-woven fabric is sequentially subjected to impregnation of water-based polyurethane sizing, coagulation drying, toluene reduction, oiling, rubbing, grinding, and dyeing and finishing process with acidic dye liquor to obtain the required sandwich rainbow structure water-based leather base cloth;

[0042] The impregnation sizing process comprises: adding 100 parts of water-based polyurethane, 0.5 parts of polyurethane thickening agent, and 80 parts of pure water into a reaction kettle for stirring, the stirring speed of the stirrer is 2800r / min, the stirring time is 30min, and the viscosity is controlled at 1800-2500cps;

[0043] In the coagulation drying process, a 9-stage oven gradient heating drying is used, the temperatures are set at 85℃, 95℃, 105℃, 110℃, 115℃, 125℃, 125℃, 135℃ and 135℃ respectively, and the vehicle speed is 7m / min, thereby preparing the impregnated sandwich base cloth;

[0044] In the toluene reduction process, there are 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86℃, and tanks 8-10 are water washing tanks with a temperature of 99-101℃; the vehicle speed is 7.5-9.5m / min, thereby preparing the indefinite island sandwich superfine base cloth after opening;

[0045] The acid dyeing liquid in the acid dyeing and finishing process comprises 7% of organic sulfonate red dye, 1.8% of acetic acid, 0.25% of amine homogenizing agent, 3% of fixing agent, and 87.95% of water; the dyeing and finishing process is that the sanded sandwich leather base cloth is put into the acid dyeing liquid for dyeing at room temperature for 90 minutes, after dyeing, the temperature is increased to 85 DEG C at a rate of 2 DEG C / min and kept for 30 minutes, then the temperature is decreased to 55 DEG C, washed with water for 3 times, the temperature is increased to 85 DEG C at a rate of 2 DEG C / min for fixing and kept for 30 minutes, then the temperature is decreased to room temperature, washed with water for 3 times, and a sandwich rainbow structure water-based fiber leather base cloth is prepared;

[0046] Step 3: the sandwich rainbow structure water-based fiber leather base cloth is subjected to dry lamination to obtain a sandwich rainbow structure water-based microfiber synthetic leather.

[0047] The prepared sandwich rainbow structure water-based microfiber synthetic leather has clear red and yellow levels in the cross section, and the yellow polyester core layer is not stained with red dye, and the color of the core layer is bright yellow.

[0048] Experimental group 2

[0049] A preparation method of a sandwich rainbow structure water-based fiber leather base cloth comprises the following steps:

[0050] Step 1: indefinite island fiber is prepared by mixing 55% PA chip as island phase and 45% PE chip as sea phase, and non-woven fabric is prepared by needle punching process; a sandwich core non-woven fabric is prepared by needle punching composite process, and the thickness and gram weight of the sandwich core non-woven fabric are set; the sandwich core non-woven fabric comprises, from top to bottom, an upper indefinite island and sea fiber layer, a polyester mesh cloth layer, and a lower indefinite island and sea fiber layer.

[0051] The needle punching composite process is a two-time needle punching composite process, the yellow polyester mesh cloth layer is placed below the upper indefinite island and sea fiber layer, and the needle punching and crosslinking are carried out according to the set needle punching process, and the non-woven fabric with the upper indefinite island and sea fiber layer and the yellow polyester mesh cloth layer is obtained; the lower indefinite island and sea fiber layer is placed below the combined yellow polyester mesh cloth layer, and the needle punching and crosslinking are carried out according to the set needle punching process, and the sandwich core non-woven fabric is obtained; the needle is a single hook R-100 type during the needle punching process, and the needle density is 1680C / cm 2 ;

[0052] Step 2: the sandwich core non-woven fabric is sequentially subjected to impregnation of water-based polyurethane sizing agent, coagulation and drying, toluene reduction, oiling, skin rubbing, sanding, and acid dyeing and finishing process to obtain the required sandwich rainbow structure water-based fiber leather base cloth.

[0053] The impregnation water-based polyurethane sizing process includes the following steps: 100 parts of water-based polyurethane, 1 part of polyurethane thickening agent, and 80 parts of pure water are added to a reaction kettle for stirring, the stirring speed is 2800 r / min, the stirring time is 30 min, and the viscosity is controlled at 1800-2500 cps;

[0054] In the solidification drying process, 9-stage ovens are used for gradient heating and drying, the temperatures are set at 85℃, 95℃, 105℃, 110℃, 115℃, 125℃, 125℃, 135℃ and 135℃ respectively, and the vehicle speed is 7 m / min, thereby obtaining the impregnated sandwich base cloth;

[0055] In the toluene reduction process, there are 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86℃, and tanks 8-10 are water washing tanks with a temperature of 99-101℃; the vehicle speed is 7.5-9.5 m / min, thereby obtaining the opened sandwich island sandwich super fiber base cloth;

[0056] In the acid dyeing process, the acid dyeing solution includes: 10% organic sulfonate red dye, 3% acetic acid, 0.5% amine compound leveling agent, 4% fixing agent, and 82.5% water; the dyeing process is as follows: the abraded sandwich leather base cloth is dyed in the acid dyeing solution at room temperature for 90 min, then the temperature is raised to 85℃ at a rate of 2℃ / min and kept for 30 min, then the temperature is lowered to 55℃, washed with water for 3 times, the temperature is raised to 85℃ at a rate of 2℃ / min and kept for 30 min for fixing, then the temperature is lowered to room temperature, washed with water for 3 times, thereby obtaining the sandwich rainbow structure water-based fiber leather base cloth;

[0057] Step 3: The sandwich rainbow structure water-based fiber leather base cloth is subjected to dry lamination to obtain the sandwich rainbow structure water-based super fiber synthetic leather.

[0058] The prepared sandwich rainbow structure water-based super fiber synthetic leather has clear red and yellow layers in the cross-section, and the yellow core polyester layer is not stained with red dye, and the core layer has bright yellow color.

[0059] Experimental group 3

[0060] A preparation method of a sandwich rainbow structure water-based fiber leather base cloth includes the following steps:

[0061] Step 1: The non-woven fabric is prepared by mixing 55% PA chips as island phase and 45% PE chips as sea phase, and using needle punching process; the sandwich core non-woven fabric is prepared by needle punching composite process, and the thickness and gram weight of the sandwich core non-woven fabric are determined; the sandwich core non-woven fabric includes, from top to bottom, an upper non-island sea-island fiber layer, a polyester mesh layer, and a lower non-island sea-island fiber layer;

[0062] The needle punching composite process is a secondary needle punching composite process. First, the yellow polyester mesh cloth layer is placed below the upper undefined island sea-island fiber layer, and is needle punched and cross-linked according to the set needle punching process, and the non-woven fabric with the upper undefined island sea-island fiber layer and the yellow polyester mesh cloth layer is obtained by winding. Then, the lower undefined island sea-island fiber layer is placed below the yellow polyester mesh cloth layer, and is needle punched and cross-linked according to the set needle punching process, to obtain a sandwiched non-woven fabric. During the needle punching process, the needle is a single hook R-100 type, and the needle density is 1680C / cm 2 ;

[0063] Step 2: The sandwiched non-woven fabric is sequentially subjected to impregnation of water-based polyurethane slurry, coagulation drying, toluene reduction, oiling, rubbing, grinding, and dyeing and finishing process with acidic dye liquor, to obtain the required sandwiched rainbow structure water-based leather base fabric.

[0064] In the impregnation of water-based polyurethane slurry process, the preparation process of the impregnation slurry is as follows: 100 parts of water-based polyurethane, 1.5 parts of polyurethane thickening agent and 80 parts of pure water are added to a reaction kettle for stirring, the stirring speed of the stirrer is 2800r / min, the stirring time is 30min, and the viscosity is controlled at 1800-2500cps.

[0065] In the coagulation drying process, 9-stage oven gradient heating drying is adopted, the temperatures are set at 85℃, 95℃, 105℃, 110℃, 115℃, 125℃, 125℃, 135℃ and 135℃ respectively, and the vehicle speed is 7m / min, to obtain the impregnated sandwiched base fabric.

[0066] In the toluene reduction process, there are a total of 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86℃, and tanks 8-10 are water washing tanks with a temperature of 99-101℃; the vehicle speed is 7.5-9.5m / min, to obtain the undefined island sandwiched superfine base fabric after opening.

[0067] In the dyeing and finishing process with acidic dye liquor, the acidic dye liquor includes: 5% organic sulfonate red dye, 1% acetic acid, 0.2% amine compound leveling agent, 2% fixing agent, and 91.8% water; the dyeing and finishing process is as follows: the ground sandwiched leather base fabric is put into the acidic dye liquor for normal temperature dyeing for 90min, after dyeing, the temperature is raised to 85℃ at a rate of 2℃ / min and kept for 30min, then the temperature is lowered to 55℃, washed with water for 3 times, the temperature is raised to 85℃ at a rate of 2℃ / min for fixing and kept for 30min, then the temperature is lowered to normal temperature, washed with water for 3 times, to obtain the sandwiched rainbow structure water-based leather base fabric.

[0068] Step 3: The sandwiched rainbow structure water-based leather base fabric is subjected to dry lamination to obtain a sandwiched rainbow structure water-based superfine synthetic leather.

[0069] The prepared sandwiched rainbow structure water-based superfine synthetic leather has clear red and yellow layers in the cross-section, the yellow sandwiched polyester layer is not stained with red dye, and the color of the sandwiched layer is bright yellow.

[0070] Experiment group 4

[0071] A preparation method of sandwich rainbow structure water-based leather base cloth, comprising the following steps:

[0072] Step 1: adopting 55% PA chip as island phase and 45% PE chip as sea phase to prepare indefinite island fiber, and adopting needle punching process to prepare non-woven fabric; through needle punching composite process, sandwich core non-woven fabric is prepared, and the thickness and gram weight of the sandwich core non-woven fabric are determined; the sandwich core non-woven fabric comprises, from top to bottom, an upper indefinite island fiber layer, a polyester mesh layer, and a lower indefinite island fiber layer;

[0073] The needle punching composite process is a secondary needle punching composite process, the green polyester mesh layer is placed below the upper indefinite island fiber layer, and cross-linking is performed according to the set needle punching process, and the non-woven fabric with the upper indefinite island fiber layer and the green polyester mesh layer is obtained; the lower indefinite island fiber layer is placed below the composite green polyester mesh layer, and cross-linking is performed according to the set needle punching process, and the sandwich core non-woven fabric is obtained; during the needle punching process, the needle is a single hook R-100 type, and the needle density is 1680C / cm 2 ;

[0074] Step 2: the sandwich core non-woven fabric is sequentially subjected to impregnation of water-based polyurethane slurry, coagulation drying, toluene reduction, oiling, kneading, buffing, and dyeing and finishing process with acidic dye liquor, to obtain the required sandwich rainbow structure water-based leather base cloth;

[0075] In the impregnation of water-based polyurethane slurry process, the preparation process of the impregnation slurry is as follows: 100 parts of water-based polyurethane, 0.5 parts of polyurethane thickening agent, and 80 parts of pure water are added to a reaction kettle for stirring, the stirring speed of the stirrer is 2800r / min, the stirring time is 30min, and the viscosity is controlled at 1800-2500cps;

[0076] In the coagulation drying process, 9-stage oven gradient heating drying is adopted, the temperatures are set at 85℃, 95℃, 105℃, 110℃, 115℃, 125℃, 125℃, 135℃ and 135℃ respectively, and the vehicle speed is 7m / min, to obtain the impregnated sandwich base cloth;

[0077] In the toluene reduction process, there are 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86℃, and tanks 8-10 are water washing tanks with a temperature of 99-101℃; the vehicle speed is 7.5-9.5m / min, and the indefinite island sandwich superfine base cloth after opening is obtained;

[0078] The acid dyeing liquid in the acid dyeing and finishing process comprises 7% of organic sulfonate red dye, 1.8% of acetic acid, 0.25% of amine leveling agent, 3% of fixing agent, and 87.95% of water; the dyeing and finishing process is that the sanded sandwich leather base cloth is put into the acid dyeing liquid for dyeing at room temperature for 90 minutes, then the temperature is raised to 85 DEG C at a rate of 2 DEG C / min and kept for 30 minutes, then the temperature is lowered to 55 DEG C, and the sandwich leather base cloth is washed for 3 times, then the temperature is raised to 85 DEG C at a rate of 2 DEG C / min for fixing and kept for 30 minutes, then the temperature is lowered to room temperature, and the sandwich leather base cloth is washed for 3 times, thereby obtaining the sandwich rainbow structure water-based microfiber leather base cloth;

[0079] Step 3: the sandwich rainbow structure water-based microfiber leather base cloth is subjected to dry lamination to obtain the sandwich rainbow structure water-based microfiber synthetic leather.

[0080] The prepared sandwich rainbow structure water-based microfiber synthetic leather has clear red and green layers in the cross section, and the green core polyester layer is not stained with red dye, and the core layer has bright green color.

[0081] Comparative group 1

[0082] A preparation method of a sandwich rainbow structure water-based microfiber leather base cloth comprises the following steps:

[0083] Step 1: indefinite island fiber is prepared by mixing 55% PA chip as island phase and 45% PE chip as sea phase, and non-woven fabric is prepared by needle punching process; a sandwich core non-woven fabric is prepared by needle punching composite process, and the thickness and gram weight of the sandwich core non-woven fabric are determined; the sandwich core non-woven fabric comprises, from top to bottom, an upper indefinite island and sea fiber layer, a nylon mesh layer, and a lower indefinite island and sea fiber layer.

[0084] The needle punching composite process is a secondary needle punching composite process, the yellow nylon mesh layer is placed below the upper indefinite island and sea fiber layer, and the upper indefinite island and sea fiber layer and the yellow nylon mesh layer are crosslinked by needle punching according to the set needle punching process, and the non-woven fabric is obtained; then the lower indefinite island and sea fiber layer is placed below the combined yellow nylon mesh layer, and the sandwich core non-woven fabric is obtained by crosslinking according to the set needle punching process; the needle is a single hook R-100 type, and the needle density is 1680C / cm 2 ;

[0085] Step 2: the sandwich core non-woven fabric is sequentially subjected to impregnation of water-based polyurethane sizing agent, coagulation drying, toluene reduction, oiling, skin rubbing, sanding, and acid dyeing and finishing process, thereby obtaining the required sandwich rainbow structure water-based microfiber leather base cloth.

[0086] The impregnation water-based polyurethane sizing process includes the following steps: 100 parts of water-based polyurethane, 0.5 parts of polyurethane thickening agent, and 80 parts of pure water are added to a reaction kettle for stirring, the stirring speed of the stirrer is 2800 r / min, the stirring time is 30 min, and the viscosity is controlled at 1800-2500 cps;

[0087] In the solidification drying process, a 9-stage oven gradient heating drying is adopted, the temperatures are set at 85℃, 95℃, 105℃, 110℃, 115℃, 125℃, 125℃, 135℃ and 135℃ respectively, and the vehicle speed is 7 m / min, thereby obtaining the impregnated sandwich base cloth;

[0088] In the toluene reduction process, there are 10 tanks, tanks 1-7 are toluene tanks with a temperature of 83-86℃, and tanks 8-10 are water washing tanks with a temperature of 99-101℃; the vehicle speed is 7.5-9.5 m / min, thereby obtaining the opened sandwich island sandwich super fiber base cloth;

[0089] In the acid dyeing process, the acid dyeing solution includes: 7% organic sulfonate red dye, 1.8% acetic acid, 0.25% amine leveling agent, 3% fixing agent, and 87.95% water; the dyeing process is as follows: the abraded sandwich leather base cloth is dyed in the acid dyeing solution at room temperature for 90 min, then heated to 85℃ at a rate of 2℃ / min and kept for 30 min, then cooled to 55℃, washed with water for 3 times, heated to 85℃ at a rate of 2℃ / min for fixing and keeping for 30 min, then cooled to room temperature and washed with water for 3 times, thereby obtaining the sandwich rainbow structure water-based fiber leather base cloth;

[0090] Step 3: The sandwich rainbow structure water-based fiber leather base cloth is subjected to dry lamination to obtain the sandwich structure rainbow water-based super fiber synthetic leather.

[0091] The obtained sandwich structure water-based super fiber synthetic leather has a yellow nylon mesh cloth layer that is completely dyed with red acid dyeing solution, and has a bright red color. The sandwich structure does not have the characteristics of clear rainbow layers.

[0092] The mechanical properties and color fastness of the water-based super fiber synthetic leather obtained in the experimental groups 1-4 and the comparative group 1 are tested, and the related parameters are recorded for comparison. (The tensile strength is tested by AN-PZ-W-060 method, and the tear resistance is tested by AN-PZ-W-064 method)

[0093] Table 1 Related parameters and test conditions of the synthetic leather obtained in the experimental groups 1-4 and the comparative group 1

[0094]

[0095]

[0096] According to Table 1, it can be seen that: the sandwich nonwoven fabric with three-layer structure is also used, and the sandwich layer of the experimental groups 1-4 uses polyester material, and the tensile strength and tear resistance of the prepared sandwich rainbow structure water-based microfiber synthetic leather are more excellent than that of the nylon material of the comparative group 1, and the mechanical properties are higher. In the color fastness test, the color transfer grade, rubbing fastness and sweat fastness test of the experimental groups 1-4 are all 5 levels, which are also better than those of the comparative group 1, and therefore the color fastness is higher.

[0097] Although the specific embodiments of the present application are described above, those skilled in the art should understand that the specific embodiments described are only illustrative, and are not intended to limit the scope of the present application, and equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present application should be covered within the scope of the claims of the present application.

Claims

1. A method for preparing sandwich rainbow structure water-based leather base cloth, characterized in that: It comprises the following steps: Step one: sandwich sandwich non-woven fabric is prepared by needle punching composite process, and the thickness and gram weight of the sandwich sandwich non-woven fabric are determined; The sandwich sandwich non-woven fabric comprises upper and lower island fiber layers, polyester mesh layer and lower island fiber layer from top to bottom; Step two: the sandwich sandwich non-woven fabric is immersed in water-based polyurethane slurry, solidified and dried, toluene is reduced, oiled, kneaded, sanded and dyed with acid dye liquor by acid dyeing process to obtain the required sandwich rainbow structure water-based leather base fabric; Based on the characteristics of polyester not adhering to acid dye liquor, the sanded sandwich leather base fabric is dyed with acid dye liquor; The acid dye liquor comprises: 5-10% organic sulfonate dye, 1-3% acetic acid, 0.2-0.5% amine compound leveling agent, 2-4% fixing agent and 82.5-91.8% water.

2. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 1, characterized in that: The upper and lower island fiber layers are first mixed with 45%-55% PA chips as island phase and 45%-55% PE chips as sea phase to prepare the island fiber, and then the non-woven fabric is prepared by needle punching process.

3. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 2, characterized in that: The gram weight of the upper and lower island fiber layers is 180-250g / m², and the needle punching thickness is 1.2-1.5mm; The gram weight of the polyester mesh layer is 70-100g / m², and the needle punching thickness is 0.6-0.8mm.

4. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 1, characterized in that: The needle punching composite process in step one is a two-step needle punching composite process. The polyester mesh layer is placed below the upper island fiber layer, and the needle punching is crosslinked according to the set needle punching process. The upper island fiber layer and the polyester mesh layer are wound to obtain the non-woven fabric. Then the fibrous layer of the Xiaobudao Island is placed below the compounded polyester mesh cloth layer, and is cross-linked according to the set needling process, to obtain a sandwiched non-woven fabric; the needling process uses R-100 single-hooked needle; the needling density in the needling process is 1500-1850C / cm 2 .

5. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 1, characterized in that: The dyeing process comprises the following steps: the sanded sandwich leather base fabric is dyed in acid dye liquor at room temperature for 65-130min, the temperature is raised to 70-105℃ at a rate of 2℃ / min after dyeing, and the temperature is kept for 30-40min, the temperature is lowered to 55℃, washed 2-3 times, the temperature is raised to 70-105℃ at a rate of 2℃ / min for fixing, and the temperature is kept for 30-40min, the temperature is lowered to room temperature, and the temperature is washed 2-3 times to obtain the sandwich rainbow structure water-based leather base fabric.

6. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 1, characterized in that: In the water-based polyurethane slurry process of step two, the preparation process of the impregnated slurry is: water-based polyurethane 100 parts, polyurethane thickening agent 0.5-1.5 parts, pure water 50-80 parts are added into the reaction kettle for stirring, the stirring speed is 2200-3800r / min, the time is 30-40min, and the viscosity is controlled at 1800-2500cps.

7. The method for preparing the sandwich rainbow structure waterborne fiber leather base fabric as described in claim 1, characterized in that: In the toluene reduction process of step two, there are 10 tanks, 1-7 tanks are toluene tanks with a temperature of 83-86℃, and 8-10 tanks are water washing tanks with a temperature of 99-101℃; The speed is 7.5-9.5m / min, and the opened island sandwich superfine base fabric is prepared.

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