CN109355921B

CN109355921B - Microfiber leather processing technology

Info

Publication number: CN109355921B
Application number: CN201811548487.1A
Authority: CN
Inventors: 孙灿
Original assignee: Fujian Topsun Microfiber Co ltd
Current assignee: Fujian Topsun Microfiber Co ltd
Priority date: 2018-12-18
Filing date: 2018-12-18
Publication date: 2021-04-06
Anticipated expiration: 2038-12-18
Also published as: CN109355921A

Abstract

The invention provides a microfiber leather processing technology, which breaks through the technological form of the traditional microfiber leather, so that microfiber polyurethane base cloth is solidified through a solidification tank to form a microfiber polyurethane leather film with foam holes; then sequentially washing and drying the microfiber polyurethane skin film to prepare a microfiber polyurethane blank layer with foam holes; then immersing the microfiber polyurethane blank layer into silica sol to fill the silica sol into the foam pores of the microfiber polyurethane blank layer to prepare a microfiber polyurethane sol blank layer; then, the silica sol in the foam holes of the microfiber polyurethane sol blank layer is subjected to aerogel process treatment, so that the silica sol is converted into silica aerogel to prepare a microfiber polyurethane aerogel film, namely, the foam holes of the microfiber polyurethane aerogel film are filled with the aerogel, and the microfiber polyurethane aerogel film has large foam holes and small foam holes, has high porosity, has stronger storage and saturation effects on air on the basis of overall ventilation, air permeability and moisture permeability, and has remarkable heat insulation, heat preservation and cold protection performances.

Description

Microfiber leather processing technology

Technical Field

The invention relates to the field of leather processing, in particular to a microfiber leather processing technology.

Background

The microfiber is short for superfine fiber PU synthetic leather, and is superfine fiber short fiber which is made into non-woven fabric with a three-dimensional structure network through carding and needling, and then is processed by a wet method, PU resin is impregnated, alkali is reduced, and leather grinding, dyeing and finishing and other processes are carried out to finally prepare the superfine fiber leather. Superfine fiber is added into PU polyurethane, so that the toughness, air permeability and wear resistance are further enhanced; has excellent wear resistance, cold resistance, air permeability and aging resistance.

The processing technology of the microfiber leather is well known, for example, the chinese invention patent CN 108642891A discloses a method for preparing microfiber leather, and the production line sequentially comprises sea island short fibers → high-density spunlace nonwoven fabric → ironing shrinkage → wet method PU resin impregnation → toluene decrement extraction → drying and tentering → oiling and softening → rolling → dry method PU veneering → functional treatment → microfiber leather; sea-island short fiber: selecting nylon chips and polyethylene chips, and preparing sea-island short fibers by blending spinning; preparing a high-density spunlace non-woven fabric: feeding, opening, carding and lapping the sea-island short fibers to form a fiber layer with a certain thickness, and mutually intertwining the fibers by using a spunlace method to prepare a three-dimensional structure base fabric with a certain thickness and corresponding density; ironing and shrinking: shrinking in a constant-temperature water bath at the temperature of 75 ℃; wet impregnation of PU resin: soaking the three-dimensional structure base cloth in polyurethane resin with a certain concentration, and fully and uniformly distributing impregnation liquid into gaps of the base cloth in a rolling mode; toluene reduction extraction: dipping the grey cloth in a toluene solution, repeatedly dipping at a specified temperature, and pressing a roller for a certain time to obtain bundle-shaped superfine fibers; dry-process PU veneering: coating a certain amount of polyurethane resin on release paper by a blade coating method, forming a polyurethane film after a solvent is volatilized, and transferring and compounding the polyurethane film to the surface of the microfiber leather. The preparation method of the polyurethane resin comprises the following steps: adding a solvent, polyol and low-molecular-weight diol into a reaction kettle in sequence, fully stirring, controlling the temperature of the kettle to be 45 ℃, adding MT, heating to 80 ℃, reacting at a constant temperature for 2 hours, adding a chain extender and the solvent, stirring uniformly, adding MT, keeping the temperature at 90 ℃, adding methanol and DMF after 2 hours, stopping the reaction, and adding malic acid and DMF to obtain the polyurethane resin. The thickness of the formed fiber layer is 5-6 mm. And (3) dry PU veneering, namely preparing polyurethane resin into the material with the concentration of 20%, coating the polyurethane resin on release paper in a scraping way to form a film, drying the film in an oven at the temperature of 127 ℃, naturally cooling the film, and standing the film for 48 hours.

The processing technology of the microfiber leather is similar to that of other microfiber leathers in the market, and the heat insulation, heat preservation and cold-proof performance of the formed microfiber leather needs to be improved.

Accordingly, the present inventors have made extensive studies to solve the above problems and have made the present invention.

Disclosure of Invention

The invention aims to provide a microfiber leather processing technology which has stronger air storage and saturation effects and obvious heat insulation, heat preservation and cold prevention performances on the basis of integral ventilation, air permeability and moisture permeability.

In order to achieve the purpose, the invention adopts the following technical scheme:

a microfiber leather processing technology comprises the following steps:

(1) preparing a microfiber base cloth with a certain length along the direction of a production line, preparing polyurethane slurry and a coagulating aqueous solution, wherein the polyurethane slurry takes DMF as a main solvent, and the coagulating aqueous solution comprises water and DMF;

(2) making the microfiber base cloth contain polyurethane slurry to prepare the microfiber polyurethane base cloth;

(3) a solidification tank is used for containing the solidification aqueous solution, and the microfiber polyurethane base cloth forms a microfiber polyurethane skin film with foam holes through the solidification tank;

(4) then sequentially washing and drying the microfiber polyurethane skin film to prepare a microfiber polyurethane blank layer with foam holes;

(5) then immersing the microfiber polyurethane blank layer into silica sol to fill the silica sol into the foam pores of the microfiber polyurethane blank layer to prepare a microfiber polyurethane sol blank layer;

(6) and then carrying out aerogel process treatment on the silica sol in the foam holes of the microfiber polyurethane sol blank layer to convert the silica sol into silica aerogel so as to prepare the microfiber polyurethane aerogel film.

In the step (5), the following steps are performed:

A. preparing silica sol, mixing and stirring ethanol, tetraethoxysilane and deionized water uniformly, then adding an acidic catalyst and stirring uniformly to prepare the silica sol;

B. after adding an alkaline catalyst to the silica sol, the microfiber polyurethane blank layer was immersed in the silica sol.

In the step (6), the aerogel process is a supercritical drying process or an atmospheric drying process;

the normal pressure drying process comprises the following steps:

a. immersing the microfiber polyurethane sol blank layer into silica sol, standing for 2-6 hours at 45-55 ℃ to convert the silica sol into silica gel, and preparing the microfiber polyurethane gel blank layer;

b. adding ethanol into the silica gel for aging treatment;

c. adding a hydrophobic solution into the aged silica gel for hydrophobic treatment, wherein the hydrophobic solution comprises trimethylchlorosilane and normal hexane;

d. then, cleaning the silica gel with a cleaning solution, and stopping cleaning when the pH value of the used cleaning solution is 6.8-7.2; the cleaning solution comprises a normal hexane solution;

e. and taking the microfiber polyurethane gel blank layer out of the silica gel, and drying at normal pressure to convert the silica gel in the cells of the microfiber polyurethane gel blank layer into aerogel so as to prepare the microfiber polyurethane aerogel film.

In the step e, the microfiber polyurethane gel blank layer is dried for 20 to 22 hours in a normal temperature environment to prepare a microfiber polyurethane aerogel film, or the microfiber polyurethane gel blank layer is dried for 23 to 25 hours in a 45 to 55 ℃ environment to prepare the microfiber polyurethane aerogel film, or the microfiber polyurethane gel blank layer is dried for 23 to 25 hours in a 65 to 75 ℃ environment to prepare the microfiber polyurethane aerogel film.

In the step (1), the volume of DMF is 2.5 to 4.5 times the volume of polyurethane when the polyurethane slurry is formulated.

In the step (3), applying high air pressure to the solidification aqueous solution to make air be dissolved into the solidification aqueous solution to prepare high-pressure solidification liquid; then immersing the microfiber polyurethane base cloth into the high-pressure solidification liquid, and then decompressing the high-pressure solidification liquid to expand air in the high-pressure solidification liquid entering the polyurethane so as to form bubbles in the polyurethane in the microfiber polyurethane base cloth.

In the step (3), a high-pressure container is used for containing the solidification aqueous solution, the solidification aqueous solution is positioned at the lower part of the high-pressure container, and the upper part of the high-pressure container is air; opening the high-pressure container, putting the microfiber polyurethane base cloth into the air of the high-pressure container, then closing the high-pressure container, and filling the air into the high-pressure container by using an air filling device, so that the air pressure in the high-pressure container is between 1.3 and 2 standard atmospheric pressures;

in the step (3), the microfiber polyurethane base cloth is immersed in the high-pressure solidification liquid, then the high-pressure container is opened, the air and the high-pressure solidification liquid in the high-pressure container are decompressed, and then the microfiber bubble polyurethane base cloth is taken out of the high-pressure container.

In the step (1), when the microfiber base cloth is manufactured, the microfiber base cloth is soaked firstly, part of water is extruded out through a squeezing roller, and then the microfiber base cloth is ironed through an ironing roller; when the polyurethane slurry is prepared, firstly adding DMF liquid into a container, then adding wood powder into the DMF liquid, uniformly stirring, and then adding polyurethane, wherein the volume of the DMF is 3-4 times of that of the polyurethane; the coagulating aqueous solution contains 20-25% by volume of DMF;

in the step (3), the temperature in the coagulation tank is 20-25 ℃; the setting time of the microfiber polyurethane base cloth in the setting tank is 7-10 minutes;

in the step (4), the drying temperature is 110-.

In the step (1), when the polyurethane slurry is prepared, finally adding an anionic surfactant, a nonionic surfactant and color paste and uniformly stirring; the anionic surfactant accounts for 1-2% of the total weight of the polyurethane slurry; the nonionic surfactant accounts for 1.5-2.5% of the total weight of the polyurethane slurry; the color paste accounts for 6 to 7 percent of the total weight of the polyurethane paste; the wood powder is between 420 and 500 meshes and accounts for 6 to 7 percent of the total weight of the polyurethane slurry; and finally, carrying out vacuum defoaming treatment on the polyurethane slurry for 30-45 minutes, and then filtering the polyurethane slurry by using a filter screen with 70-90 meshes.

In the step (1), when preparing the polyurethane slurry, adding a DMF (dimethyl formamide) liquid into a container, then adding wood powder into the DMF liquid and uniformly stirring, then sequentially adding an anionic surfactant, a nonionic surfactant, water, a defoaming agent, a leveling agent and the like, continuously stirring for more than 5 minutes, then adding polyurethane resin and a coloring agent, stirring at a high speed for 18-22 minutes, and simultaneously defoaming in vacuum for 30-45 minutes; wherein the volume of the DMF is 3-4 times of that of the polyurethane; the wood powder is between 420 and 500 meshes and accounts for 6 to 7 percent of the total weight of the polyurethane slurry; and finally filtering the polyurethane slurry through a filter screen with 70-90 meshes.

After the technical scheme is adopted, the microfiber leather processing technology breaks through the process form of the traditional microfiber leather, the microfiber base cloth with a certain length in the flow line direction is prepared, the polyurethane slurry and the solidification aqueous solution are prepared, the polyurethane slurry takes DMF as a main solvent, and the solidification aqueous solution comprises water and DMF; making the microfiber base cloth contain polyurethane slurry to prepare the microfiber polyurethane base cloth; the coagulating tank is used for containing the coagulating aqueous solution, and the microfiber polyurethane base cloth is coagulated through the coagulating tank to form a microfiber polyurethane skin film with foam holes; then washing and drying the microfiber polyurethane skin membrane in sequence to prepare a microfiber polyurethane blank layer with foam holes, wherein the residual impurities such as DMF (dimethyl formamide) can be washed away by washing to form the cleaned foam holes of the microfiber polyurethane blank layer, and the moisture in the foam holes of the microfiber polyurethane blank layer can be removed by drying to ensure that the microfiber polyurethane blank layer is pure and the component proportion of the subsequent process cannot be influenced; then immersing the microfiber polyurethane blank layer into silica sol to enable the silica sol to be filled into the cells of the microfiber polyurethane blank layer to prepare a microfiber polyurethane sol blank layer, wherein the cells of the microfiber polyurethane blank layer are filled with the silica sol; then carry out aerogel technology to the silica sol in the super fine polyurethane sol blank layer cell and handle, make the silica sol turn into silica aerogel, make super fine polyurethane aerogel membrane, namely pack by the aerogel in the cell of super fine polyurethane aerogel membrane, have the great cell that forms on polyurethane and the less cell that forms on the aerogel simultaneously, have high porosity, on the basis of whole ventilation and moisture permeability, have stronger storage and saturation effect to the air, it separates the temperature to have showing, keeps warm, winter protection performance. Compared with the prior art, the microfiber leather processing technology has stronger storage and saturation effects on air on the basis of integral ventilation, air permeability and moisture permeability, and has remarkable heat insulation, heat preservation and cold-proof performances.

Detailed Description

In order to further explain the technical solution of the present invention, the following detailed description is given by way of specific examples.

The invention relates to a microfiber leather processing technology, which comprises the following steps:

(1) preparing microfiber base cloth with a certain length along the direction of an assembly line, preparing polyurethane slurry and a coagulating aqueous solution, wherein the polyurethane slurry takes DMF (dimethyl formamide) as a main solvent, and the coagulating aqueous solution comprises water and DMF;

(3) a coagulating tank is used for containing a coagulating aqueous solution, and the microfiber polyurethane base cloth is coagulated through the coagulating tank to form a microfiber polyurethane skin film with foam holes;

(4) then washing and drying the microfiber polyurethane skin membrane in sequence to prepare a microfiber polyurethane blank layer with foam holes, wherein the residual impurities such as DMF (dimethyl formamide) can be washed away by washing to form the cleaned foam holes of the microfiber polyurethane blank layer, and the moisture in the foam holes of the microfiber polyurethane blank layer can be removed by drying to ensure that the microfiber polyurethane blank layer is pure and the component proportion of the subsequent process cannot be influenced;

(5) then immersing the microfiber polyurethane blank layer into silica (specifically, silica) sol, and filling the silica sol into the cells of the microfiber polyurethane blank layer to prepare a microfiber polyurethane sol blank layer, wherein the cells of the microfiber polyurethane blank layer are filled with the silica sol;

(6) then carry out aerogel technology to the silica sol in the super fine polyurethane sol blank layer cell and handle, make the silica sol turn into silica aerogel, make super fine polyurethane aerogel membrane, namely pack by the aerogel in the cell of super fine polyurethane aerogel membrane, have the great cell that forms on polyurethane and the less cell that forms on the aerogel simultaneously, have high porosity, on the basis of whole ventilation and moisture permeability, have stronger storage and saturation effect to the air, it separates the temperature to have showing, keeps warm, winter protection performance.

Preferably, in step (5), the following steps are performed:

A. preparing silica sol, mixing and stirring ethanol, tetraethoxysilane and deionized water uniformly, then adding an acidic catalyst and stirring uniformly to prepare the silica sol; weighing 180-mole 220-mole ethanol, 40-60-mole ethyl orthosilicate and 250-mole 350-mole deionized water, stirring and mixing while adding the ethyl orthosilicate and the deionized water into the ethanol, adding an acidic catalyst for catalytic reaction after the mixing is finished, wherein the acidic catalyst can be hydrochloric acid of 0.015-0.025 mole, and preparing the silica sol;

B. after adding an alkaline catalyst into the silica sol, immersing the microfiber polyurethane blank layer into the silica sol; specifically, a basic catalyst is added into silica sol for catalytic reaction, wherein the basic catalyst can be 0.03-0.05 mol of ammonia water, and gel is formed by gradual reaction.

Preferably, in step (6), the aerogel process is a supercritical drying process, which is a known aerogel-producing supercritical drying process commonly used in the market.

Preferably, in step (6), the aerogel process is an atmospheric drying process;

the normal pressure drying process comprises the following steps:

a. immersing the microfiber polyurethane sol blank layer into silica sol, standing for 2-6 hours (specifically 2, 3, 4 or 6 hours) at 45-55 ℃ (specifically 45, 47, 49, 51, 53 or 55 ℃), converting the silica sol into silica gel, and preparing a microfiber polyurethane gel blank layer;

b. adding ethanol into silica gel for aging treatment, specifically completely soaking the silica gel into ethanol, and aging for about one day;

c. adding a hydrophobic solution into the aged silica gel for hydrophobic treatment for about two days, wherein the hydrophobic solution comprises trimethylchlorosilane and n-hexane, and the volume ratio of the trimethylchlorosilane to the n-hexane is 1-2: 8-9;

d. then cleaning the silica gel with a cleaning solution, wherein when the pH value of the used cleaning solution is 6.8-7.2 (specifically 6.8, 6.9, 7, 7.1 or 7.2), the cleaning is stopped when the pH value reaches neutrality; the cleaning solution comprises a normal hexane solution;

e. and taking the microfiber polyurethane gel blank layer out of the silica gel, and drying at normal pressure to convert the silica gel in the cells of the microfiber polyurethane gel blank layer into aerogel so as to prepare the microfiber polyurethane aerogel film. The super-fiber polyurethane aerogel film has the advantages that the pores of the super-fiber polyurethane aerogel film are filled with aerogel, the super-fiber polyurethane aerogel film has larger pores formed on polyurethane and smaller pores formed on aerogel, the super-fiber polyurethane aerogel film has high porosity, has stronger storage and saturation effects on air on the basis of ventilation and moisture permeation of the whole body, and has remarkable heat insulation, heat preservation and cold protection performances.

Preferably, in the step e, the microfiber polyurethane gel blank layer is dried in a normal temperature environment for 20 to 22 hours to form the microfiber polyurethane aerogel film, and then is subjected to dry veneering.

Preferably, in the step e, the microfiber polyurethane gel blank layer is dried in an environment of 45-55 ℃ for 23-25 hours to form a microfiber polyurethane aerogel film, and then is subjected to dry veneering.

Preferably, in the step e, the microfiber polyurethane gel blank layer is dried in an environment of 65-75 ℃ for 23-25 hours to form a microfiber polyurethane aerogel film, and then is subjected to dry veneering.

Preferably, in step (5), the acidic catalyst is hydrochloric acid or nitric acid, and the basic catalyst is ammonia water. Has flexible catalysis effect, and the amount of each catalyst is not suitable to be too large.

Preferably, in step b, the aging treatment time is 30 to 60 hours (specifically, 30, 40, 50, or 60 hours), i.e., a sufficient aging degree can be achieved.

Preferably, in step c, the time for the hydrophobic treatment is 30 to 60 hours (specifically, 30, 40, 50, or 60 hours), so that a sufficient hydrophobic effect can be achieved.

Preferably, in the step (1), the viscosity of the polyurethane slurry is controlled to 3000-6000 Pa.s. In the step, polyurethane can be diluted by DMF, so that the pore space in the solidified polyurethane is larger, and silica aerogel with larger volume can be accommodated, thereby improving the heat insulation, heat preservation and cold-proof performance of the finished microfiber leather.

In order to achieve the dilution effect of DMF on polyurethane, preferably, in step (1), when the polyurethane slurry is prepared, the volume of DMF is 2.5-4.5 times of the volume of polyurethane, DMF can uniformly dissolve polyurethane, and solidified polyurethane is more dispersed to form larger-space cells.

Preferably, in the step (3), high air pressure is applied to the aqueous coagulating solution to make air be dissolved in the aqueous coagulating solution to prepare a high-pressure coagulating liquid; then the microfiber polyurethane base cloth is immersed into the high-pressure solidification liquid, then the high-pressure solidification liquid is subjected to instant pressure relief, air entering the high-pressure solidification liquid in the polyurethane is expanded, bubbles are formed in the polyurethane in the microfiber polyurethane base cloth, the foaming in the polyurethane is larger under the action of the high-pressure expanded air, and the bubbles in the solidified polyurethane are larger than those in the traditional microfiber leather and can contain more aerogel.

Preferably, in step (3), the high pressure is higher than the standard atmospheric pressure, so that the air in the high pressure coagulation liquid introduced into the polyurethane can be expanded under normal pressure.

Preferably, in the step (3), a high-pressure container is used for containing the solidification aqueous solution, the solidification aqueous solution is positioned at the lower part of the high-pressure container, and the upper part of the high-pressure container is air; opening the high-pressure container, putting the microfiber polyurethane base cloth into the air of the high-pressure container, then closing the high-pressure container, and filling the air into the high-pressure container by using an air filling device, so that the air pressure in the high-pressure container is between 1.3 and 2 standard atmospheric pressures; when the air pressure in the high-pressure container is lower than 1.3 standard atmospheric pressures, the air expansion in the high-pressure solidification liquid is not obvious, and when the air pressure in the high-pressure container is higher than 2 standard atmospheric pressures, the air expansion in the high-pressure solidification liquid is excessive, the strength of polyurethane and the whole microfiber leather is seriously influenced, and the condition cost is increased.

In the step (3), the microfiber polyurethane base cloth is immersed into the high-pressure solidification liquid, then the high-pressure container is opened, the air and the high-pressure solidification liquid in the high-pressure container are subjected to instantaneous pressure relief, and then the microfiber bubble polyurethane base cloth is taken out of the high-pressure container.

Preferably, in the step (1), when the microfiber base cloth is manufactured, the microfiber base cloth is soaked, part of water is extruded out through a squeezing roller, and then the microfiber base cloth is ironed through an ironing roller; when preparing polyurethane slurry, firstly adding DMF liquid into a container, then adding wood powder into the DMF liquid and uniformly stirring, and then adding polyurethane, wherein the volume of the DMF is 3-4 times of that of the polyurethane; the wood powder is not easy to coagulate into lumps in the adding sequence, the wood powder is easier to stir uniformly, the wood powder can play a skeleton role in polyurethane, the strength is enhanced, and the viscosity of polyurethane slurry can be adjusted; the solidification aqueous solution contains 20-25% of DMF (dimethyl formamide) in parts by volume, the DMF in the solidification aqueous solution has the function of regulating the solidification speed, if the content of the DMF in the solidification aqueous solution is too high, the DMF in the polyurethane is not easy to flow out, the speed of replacing DMF by water in the solidification aqueous solution entering the polyurethane is reduced, and the solidification speed of the polyurethane is reduced; if the DMF content in the solidified aqueous solution is too low, the surface shrinkage of the microfiber base cloth is increased, so that DMF at the edge rapidly migrates into water, the speed of water permeating into polyurethane is low, certain shrinkage is generated in the polyurethane solidification process, the polyurethane is thinned and has a certain degree of curling, and therefore, some nonionic surfactant S-80 can be added during batching to delay the solidification of the edge and increase foam holes; the edge curl can also be prevented by clamping the selvedge with a clamp and adding a tension roller.

Preferably, in step (3), the temperature in the coagulation tank is 20 to 25 ℃ (specifically, 20, 21, 22, 23, 24 or 25 ℃); the setting time of the microfiber polyurethane base cloth in the setting tank is 7-10 minutes (specifically, 7, 8, 9, or 10 minutes); the microfiber polyurethane base cloth can reach enough solidification degree;

preferably, in the step (4), the drying temperature is 110-.

Preferably, in the step (1), when preparing the polyurethane slurry, adding the anionic surfactant, the nonionic surfactant and the color paste and uniformly stirring; the anionic surfactant accounts for 1-2% of the total weight of the polyurethane slurry; the nonionic surfactant accounts for 1.5 to 2.5 percent of the total weight of the polyurethane slurry; the color paste accounts for 6 to 7 percent of the total weight of the polyurethane paste; the wood powder is between 420 and 500 meshes and accounts for 6 to 7 percent of the total weight of the polyurethane slurry; and finally, carrying out vacuum defoaming treatment on the polyurethane slurry for 30-45 minutes, and then filtering the polyurethane slurry by using a filter screen with 70-90 meshes. The anionic surfactant is also called as a rapid penetrating agent, has hydrophilicity, and mainly plays a role in accelerating the exchange speed of DMF and water, improving the solidification production speed of polyurethane and homogenizing cells. The anionic surfactant (C-70 or C-90) can generate a spherical cellular structure, increase rebound resilience, air permeability and moisture permeability, and the effect is not obvious when the using amount is too low, but excessive use can cause the polyurethane to be easy to curl back and reduce the smoothness after being solidified. The non-ionic surfactant (S-80) has hydrophobicity, can delay the solidification speed of the surface, can enable DMF in the interior to exchange with water more quickly, and is not obvious in effect of low use amount, but the exchange speed of DMF and water is reduced by using excessive amount, so that the production speed is influenced.

Preferably, in the step (1), when preparing the polyurethane slurry, adding a DMF liquid into a container, then adding wood powder into the DMF liquid and uniformly stirring, then sequentially adding an anionic surfactant, a nonionic surfactant, water, a defoaming agent, a leveling agent and the like, continuously stirring for more than 5 minutes, then adding a polyurethane resin and a coloring agent, stirring at a high speed for 18-22 minutes, and simultaneously defoaming in vacuum for 30-45 minutes; wherein the volume of the DMF is 3-4 times of that of the polyurethane; the main component of the defoaming agent is liquid organic silicon, and the defoaming agent mainly has the functions of eliminating air in polyurethane slurry and reducing surface pinholes of the microfiber base cloth. The general organic silicone oil has poor compatibility with DMF, and is not suitable for application. When designing the formula, a special auxiliary agent with certain intermiscibility with DMF and strong defoaming capability is selected. The leveling agent is also a modified organic silicon assistant. The main function is to improve the flatness of the bass surface and increase the affinity between the resin and the base cloth.

Preferably, the wood powder is between 420-500 meshes and accounts for 6-7% of the total weight of the polyurethane slurry; and finally filtering the polyurethane slurry through a filter screen with 70-90 meshes.

Preferably, in the step (1), the defoaming agent accounts for 0.6-0.8% of the total weight of the polyurethane slurry, too small amount of the defoaming agent does not work, and when the amount of the defoaming agent is large, the surface of the bass leather is sunken due to poor compatibility with DMF.

Preferably, the leveling agent accounts for 0.08-0.12% of the total weight of the polyurethane slurry.

The product form of the present invention is not limited to the embodiments, and any suitable changes or modifications of the similar ideas by anyone should be considered as not departing from the patent scope of the present invention.

Claims

1. The microfiber leather processing technology is characterized by comprising the following steps:

(6) then carrying out aerogel process treatment on the silica sol in the foam holes of the microfiber polyurethane sol blank layer to convert the silica sol into silica aerogel so as to prepare a microfiber polyurethane aerogel film;

2. The microfiber leather processing process according to claim 1, wherein the microfiber leather processing process comprises the following steps: in the step (5), the following steps are performed:

3. The microfiber leather processing process according to claim 2, wherein the microfiber leather processing process comprises the following steps: in the step (6), the aerogel process is a supercritical drying process or an atmospheric drying process;

the normal pressure drying process comprises the following steps:

b. adding ethanol into the silica gel for aging treatment;

4. The microfiber leather processing process according to claim 3, wherein the microfiber leather processing process comprises the following steps: in the step e, the microfiber polyurethane gel blank layer is dried for 20 to 22 hours in a normal temperature environment to prepare a microfiber polyurethane aerogel film, or the microfiber polyurethane gel blank layer is dried for 23 to 25 hours in a 45 to 55 ℃ environment to prepare the microfiber polyurethane aerogel film, or the microfiber polyurethane gel blank layer is dried for 23 to 25 hours in a 65 to 75 ℃ environment to prepare the microfiber polyurethane aerogel film.

5. The microfiber leather processing process according to claim 4, wherein the microfiber leather processing process comprises the following steps: in the step (1), the volume of DMF is 2.5 to 4.5 times the volume of polyurethane when the polyurethane slurry is formulated.

6. The microfiber leather processing process according to claim 5, wherein the processing step comprises the following steps: in the step (3), a high-pressure container is used for containing the solidification aqueous solution, the solidification aqueous solution is positioned at the lower part of the high-pressure container, and the upper part of the high-pressure container is air; opening the high-pressure container, putting the microfiber polyurethane base cloth into the air of the high-pressure container, then closing the high-pressure container, and filling the air into the high-pressure container by using an air filling device, so that the air pressure in the high-pressure container is between 1.3 and 2 standard atmospheric pressures;

7. The microfiber leather processing process according to claim 6, wherein the microfiber leather processing process comprises the following steps: in the step (1), when the microfiber base cloth is manufactured, the microfiber base cloth is soaked firstly, part of water is extruded out through a squeezing roller, and then the microfiber base cloth is ironed through an ironing roller; when the polyurethane slurry is prepared, firstly adding DMF liquid into a container, then adding wood powder into the DMF liquid, uniformly stirring, and then adding polyurethane, wherein the volume of the DMF is 3-4 times of that of the polyurethane; the coagulating aqueous solution contains 20-25% by volume of DMF;

in the step (4), the drying temperature is 110-.

8. The microfiber leather processing process according to claim 7, wherein the microfiber leather processing process comprises the following steps: in the step (1), when the polyurethane slurry is prepared, finally adding an anionic surfactant, a nonionic surfactant and color paste and uniformly stirring; the anionic surfactant accounts for 1-2% of the total weight of the polyurethane slurry; the nonionic surfactant accounts for 1.5-2.5% of the total weight of the polyurethane slurry; the color paste accounts for 6 to 7 percent of the total weight of the polyurethane paste; the wood powder is between 420 and 500 meshes and accounts for 6 to 7 percent of the total weight of the polyurethane slurry; and finally, carrying out vacuum defoaming treatment on the polyurethane slurry for 30-45 minutes, and then filtering the polyurethane slurry by using a filter screen with 70-90 meshes.

9. The microfiber leather processing process according to claim 6, wherein the microfiber leather processing process comprises the following steps: in the step (1), when preparing the polyurethane slurry, adding a DMF (dimethyl formamide) liquid into a container, then adding wood powder into the DMF liquid and uniformly stirring, then sequentially adding an anionic surfactant, a nonionic surfactant, water, a defoaming agent and a leveling agent, continuously stirring for more than 5 minutes, then adding polyurethane resin and a coloring agent, stirring at a high speed for 18-22 minutes, and simultaneously defoaming in vacuum for 30-45 minutes; wherein the volume of the DMF is 3-4 times of that of the polyurethane; the wood powder is between 420 and 500 meshes and accounts for 6 to 7 percent of the total weight of the polyurethane slurry; and finally filtering the polyurethane slurry through a filter screen with 70-90 meshes.