CN115162011A

CN115162011A - Soft synthetic leather

Info

Publication number: CN115162011A
Application number: CN202210522664.9A
Authority: CN
Inventors: 姜秋颖
Original assignee: Wenzhou Tongying Technology Co ltd
Current assignee: Wenzhou Tongying Technology Co ltd
Priority date: 2022-05-13
Filing date: 2022-05-13
Publication date: 2022-10-11
Also published as: CN115478441B; CN115478441A

Abstract

The invention relates to soft synthetic leather which comprises a base cloth layer, a wet-process base and a dry-process laminated surface layer, wherein the wet-process base is composed of polyurethane resin, organic silicon and a filling material, and organic silicon is attached to fiber micropores of the filling material and micropores and gaps inside the polyurethane resin. The soft synthetic leather has soft hand feeling, strong meat quality feeling and good strength, is a cheap and good synthetic leather material, and can be applied to the fields of decorative materials such as clothing leather, luggage leather and the like.

Description

Soft synthetic leather

Technical Field

The invention relates to the technical field of synthetic leather manufacturing, relates to soft synthetic leather, and relates to a softening agent.

Background

The soft leather has limited natural resources and high price, so that the increasing market demand cannot be met. In order to improve the soft hand feeling of the synthetic leather, a tanning process is usually adopted in a tanning factory, an organic silicon softening agent is added into a water passing tank, finished leather is quickly soaked and rolled in the water passing tank, and then is dried, because the polyurethane resin is water-repellent, and the micropore gaps and the fiber gaps of wood fiber powder or pulp fiber powder are filled and blocked by the polyurethane resin, the softening agent cannot penetrate into the internal tissues of the fiber powder, and the softening agent cannot penetrate into the micropores of leather bass, only a very small amount of the softening agent is adsorbed into cells formed by the bass due to the shrinkage of filler fibers under the limitation of the process, the concentration of the softening agent cannot be high, and if the softening agent is excessively high, too much silicone oil is adhered to the surface of the bass, so that the dry process surface layer and the bass are easily bonded insecure.

In recent years, soft protein synthetic leather appears in the market, due to the action of polyvinyl alcohol in production ingredients, bass obtains rich and compact cells and becomes soft in hand feeling, and meanwhile, due to the fact that the polyvinyl alcohol is easy to block in a solvent recovery system, production halt and dredging are needed, a large amount of manpower and financial resources are consumed, and safety problems such as solvent leakage and pollution are easily caused. The prior manufacturing process of the soft protein synthetic leather is not suitable for mass production and difficult to popularize, so that the production efficiency is low, the manufacturing cost is high, and the price is expensive. The soft hand feeling of the soft protein synthetic leather at present depends on the compactness of Bass pores unilaterally, and if the Bass pores are more compact, the softness of the leather is better, but the peel strength of the leather is poorer. Under the condition that the living demands of people are increasingly improved, the synthetic leather material with low price, soft hand feeling and good strength is especially required to be designed in the industries of clothes, shoes, hats, cases, sofas and the like.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide the soft synthetic leather which is low in price, soft in hand feeling and good in strength.

The invention adopts the following technical scheme to complete: the soft synthetic leather comprises a base cloth layer, a wet-process base and a dry-process veneering layer, wherein the wet-process base comprises polyurethane resin, organic silicon and a filling material, and organic silicon is attached to the inner wall of a foam hole formed by the contraction of fibers of the filling material, the fiber micropore of the filling material, and the micropore and the gap inside the polyurethane resin.

Further, the weight ratio of the polyurethane resin to the organic silicon in the wet-process bass is 30:0.5-3.8.

Further, the organic silicon is 1 or 2 of amino silicone oil and amino polyether block silicone oil.

Furthermore, the wet-process bass is prepared from a wet-process mixture coated on the base cloth, the wet-process mixture comprises a polyurethane resin solvent solution, a softening agent, N-dimethylformamide and filler raw materials, the softening agent is organic silicon or an organic silicon softening agent containing organic silicon, and the polyurethane resin solvent solution contains polyurethane resin.

Furthermore, the ionic type of the organosilicon softener is cation, and the pH value of the organosilicon softener is less than 5.

Further, the organic silicon softening agent is amino silicone oil emulsion or amino polyether block silicone oil solvent solution or amino polyether block silicone oil.

Furthermore, the molecular weight of the amino polyether block silicone oil is 5000-30000, and the amino polyether block silicone oil is prepared by compounding 2 or more than 2 kinds of amino polyether block silicone oil with different molecular weights.

Further, the solid content of the organic silicon softening agent is 15-70%, the solid content of the polyurethane resin solvent liquid is 28-32%, and the weight ratio of the polyurethane resin solvent liquid to the organic silicon softening agent is 100:2-15.

Further, the filling material is one or more of wood fiber powder, paper pulp fiber powder and light calcium powder, the wood fiber powder or the paper pulp fiber powder is high-expansion fiber powder, the expansion rate is 17-25, and the mesh number is 350-700.

Further, the weight ratio of water in the wet mixture is less than 3.5%.

The invention has the following beneficial effects:

1. the interior of the wet-process bass contains organic silicon, and the organic silicon is adhered to the inner wall of a foam hole formed by the shrinkage of fibers of the filler, the fiber micropore of the filler, and the micropore and the gap in the polyurethane resin.

The organic silicon plays a role in lubricating and reducing friction coefficient, and is soft and comfortable in touch.

2. Because the bass depends on the softening action of the soft organic silicon, the foam holes are not required to be excessively compact, the firmness is good, and the peel strength and the tearing strength are good.

3. The soft organic silicon is adsorbed in foam holes and gaps of the bass, and the soft organic silicon is rarely carried away by water in a coagulating tank washing process. Meanwhile, the soft organic silicon is liquid, and a solvent recovery system is not easy to block.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, characteristics and effects according to the present invention will be given with reference to the preferred embodiments.

The invention provides soft synthetic leather which comprises a base cloth layer, a wet-process base and a dry-process veneering layer, wherein the wet-process base comprises polyurethane resin, organic silicon and a filling material, and organic silicon is attached to the inner wall of a foam hole formed by fiber shrinkage of the filling material, the fiber micropore of the filling material, and the micropore and the gap inside the polyurethane resin. The weight ratio of the polyurethane resin to the organic silicon in the wet-process bass is 30:0.5-3.8, and the optimal ratio is 30.

Wherein the organosilicon is preferably amino silicone oil or amino polyether block silicone oil. Organic silicon is attached to foam holes, micropores and gaps inside the wet base to lubricate and reduce friction coefficient, and the touch feeling is soft and comfortable.

Wet base: is made of wet-mixed material coated on base cloth. The wet-process mixture is prepared from a polyurethane resin solvent solution, a softening agent, N-dimethylformamide and a filler. Or the other mixture ratio of the wet mixture is prepared by polyurethane resin solvent liquid, a softening agent, polyvinyl alcohol, N-dimethylformamide and a filling material. The softening agent is organic silicon or organic silicon softening agent containing organic silicon, and the polyurethane resin solvent liquid contains polyurethane resin. The weight ratio of water in the wet mixture is less than 3.5%. If the wet-process mixture with the dye contains much water, the pigment is easy to permeate into water in the washing process of the coagulation tank after the wet-process mixture is coated, and the base cloth is polluted. Therefore, the weight ratio of water in the wet-process mixture is less than 3.5%, and the pollution to the base cloth is reduced.

Ionic type of silicone softener: the ionic type of the organosilicon softener is cation, and the softness of the cation organosilicon softener is obviously higher than that of the anion organosilicon softener and that of the nonionic organosilicon softener. Meanwhile, the surface of polysiloxane of the cation machine silicon softener has positive charges, and the surface of the fiber of the base cloth has negative charges, so that the polysiloxane can be well adsorbed on the surface of the fiber and is not easy to fall off.

Raw materials of the organosilicon softener: the organic silicon softening agent is amino silicone oil emulsion or amino polyether block silicone oil solvent fluid. Wherein the amino silicone oil emulsion of the amino silicone oil emulsion comprises amino silicone oil, an emulsifier and water. The amino polyether block silicone oil emulsion consists of amino polyether block silicone oil and water. The amino polyether block silicone oil solvent solution consists of amino polyether block silicone oil and a solvent, or the amino polyether block silicone oil solvent solution consists of amino polyether block silicone oil, acetic acid and a solvent, wherein the weight ratio of the amino polyether block silicone oil to the acetic acid is 60:9-18, and the optimal proportion is 60:12. wherein the solvent is one or more of butyl ether, isopropanol, N-dimethylformamide and water. The solvent is one or more of butyl ether, isopropanol and N, N-dimethylformamide.

The amino polyether block silicone oil refers to a polyorganosiloxane polyether block copolymer containing polysiloxane, amino and polyether blocks. Or the amino polyether block silicone oil is prepared by mixing and reacting epoxy-terminated polyether silicone oil, polyether amine and a solvent. The amino polyether block silicon has excellent heat resistance stability and shearing resistance, not only keeps the softer and silky feeling of amino silicone oil, but also is not sticky and yellowing-resistant, and can provide ideal moisture absorption and antistatic performance, and the leather after moisture absorption has a very drooping feeling.

The molecular weight of the amino polyether block silicone oil is 5000-30000, and the amino polyether block silicone oil is formed by compounding various amino polyether block silicone oils with different molecular weights. Specifically, the amino polyether block silicone oil can be selected from two or three combinations of the molecular weights in three ranges, wherein the three molecular weights of the amino polyether block silicone oil respectively comprise: a. the low molecular weight is 7000-9000; b. medium molecular weight is 10000-12000; c. the high molecular weight is 13000-15000. The optimal amino polyether block silicone oil comprises the following components in parts by weight and molecular weight: 70 parts of amino polyether block silicone oil with the molecular weight of 8000 and 30 parts of amino polyether block silicone oil with the molecular weight of 12000 are compounded. The amino polyether block silicone oil with low molecular weight has relatively good softness and bulkiness, the amino polyether block silicone oil with high molecular weight has relatively good smoothness, and the soft type silicone emulsion formed by compounding a plurality of amino polyether block silicone oils with different molecular weights has better softening effect.

The solid content of the organic silicon softening agent is 15-70%, the solid content of the wet polyurethane resin solvent liquid is 28-32%, and the weight ratio of the wet polyurethane resin solvent liquid to the organic silicon softening agent is 100:2-15. The optimal scheme is that a wet-process polyurethane resin solvent liquid with the solid content of 30% and an organic silicon softening agent with the solid content of 25% are combined, and the optimal weight ratio of the wet-process polyurethane resin solvent liquid to the organic silicon softening agent is 100:6.

the function of the organic silicon softening agent is as follows:

1. the filler wood fiber powder is uniformly dispersed in the wet mixture, the filler wood fiber powder is uniformly dispersed, the wet mixture is coated and then washed and dried by a coagulating tank, and the filler wood fiber powder forms a uniformly distributed cellular structure after being shrunk, so that the touch cotton feeling is strong.

2. The organosilicon softener is wrapped by polyurethane resin solvent liquid, and after the wet-process mixture is coated and washed by a coagulating tank and dried, very compact micropores containing soft organosilicon are formed in the resin, so that the bass is particularly soft. The pores and fibers of the filler adsorb soft organic silicon, so that the filler is soft.

3. The soft organic silicon is basically adsorbed in pores and gaps of the bass, the soft organic silicon is rarely carried away by water in a water washing process of a coagulation tank, and meanwhile, the solvent recovery system is not easy to block because the soft organic silicon is liquid.

4. The bass relies on the softening action of the soft organic silicon, so that excessive densification of the foam cells is not needed, and the firmness and the peel strength and the tearing strength of the bass are good.

pH of the silicone softener: the pH value of the organic silicon softener is less than 5, and the optimal pH value is 2.2. The filler is alkaline, so that the alkalinity of the wet mixture after coating is heavier and heavier in the process of washing by a coagulating tank, the organosilicon softener with the pH value of more than 7 breaks emulsion, and the organosilicon floating on the water surface pollutes base cloth to cause oil spots, so that the pH value of the organosilicon softener is designed to be less than 5, which is favorable for alkali-acid neutralization. Acetic acid is added into the organic silicon softener to adjust the pH value of the softener and ensure that the pH value of the organic silicon softener is slightly acidic.

Polyurethane resin solvent solution: the solid content of the polyurethane resin solvent liquid is 28-32%, wherein the optimal solid content is 30%. The polyurethane resin solvent liquid is a mixed liquid of wet-process polyurethane resin and a solvent, or the polyurethane resin solvent liquid is wet-process soft polyurethane resin solvent liquid, and the modulus of the wet-process soft polyurethane resin is 5-10kgf/c square meter.

Filling material: the filler is wood fiber powder or paper pulp fiber powder or light calcium powder or high-expansion fiber powder. When the filler is high-expansion fiber powder, the expansion rate is 17-25, the mesh number is 350-700, wherein the optimal expansion rate is about 20, and the optimal mesh number is about 600. The expansion coefficient of the wood fiber powder and the pulp fiber powder is large, the cells of the wood fiber powder and the pulp fiber powder after shrinkage are relatively large, and the Bass is relatively softer. Meanwhile, the finer the wood fiber powder or the pulp fiber powder is, the more compact the pores of the shrunk wood fiber powder or the shrunk pulp fiber powder is, and the softer the Bass feeling is.

Dry-process veneering: the dry-process veneering in the soft synthetic leather is prepared by dry-process mixed liquid coated on release paper. The dry-process mixed liquid is prepared from dry-process polyurethane resin, N-dimethylformamide and toner, the dry-process veneering is divided into an inner layer and an outer layer, the inner layer is adhered to the wet-process bass, wherein the hardness of the dry-process polyurethane resin in the inner layer is less than that of the dry-process polyurethane resin in the outer layer, the modulus of the dry-process polyurethane resin in the inner layer is less than 30kgf/c square meter, and the optimal modulus is 10kgf/c square meter. The modulus of the dry-process polyurethane resin of the outer layer is more than 45kgf/c square meter, wherein the optimal modulus is 80kgf/c square meter. The outer layer of the dry laminated surface layer is formed by dry organic silicon polyurethane or is formed by mixing dry organic silicon polyurethane and dry polyurethane resin. The resin has the characteristics of soft hand feeling, softness, smoothness, strong skin feeling and deep and bright color, and is suitable for stripping release paper with strong fog feeling. Because the price of the resin is higher, the dry-method silicone resin and the dry-method polyurethane resin are matched, so that the dry-method laminated surface layer has the advantages of the resin, the cost is reduced, and the dry-method laminated surface layer formed by mixing the dry-method organic silicone polyurethane and the dry-method polyurethane resin is the optimal scheme.

The manufacturing process of the soft synthetic leather comprises the following steps:

1. and preparing mixed liquor, including preparing wet mixed liquor and dry mixed liquor.

1) Preparing a wet mixed solution: firstly, the soft type organic silicon emulsion, the N, N-dimethyl formamide, the filling material, the color paste and other raw materials are mixed and stirred uniformly, then the polyurethane resin solvent liquid is added, mixed and stirred uniformly, and defoamed.

2) The preparation method of the dry mixed solution comprises the following steps:

preparing outer layer mixed liquor by a dry method: uniformly mixing and stirring high-modulus dry-process polyurethane resin, N-dimethylformamide, butanone, polyether modified organosilicon and toner, and defoaming;

b, preparing an inner layer mixed solution by a dry method: and uniformly mixing and stirring the low-modulus dry-process polyurethane resin, the N, N-dimethylformamide, the butanone, the polyether modified organic silicon and the toner, and defoaming.

2. Preparation of wet bass:

1) Base cloth pretreatment: immersing the base cloth into an N, N-dimethylformamide aqueous solution with the concentration of 15-25%, removing redundant aqueous solution by using an extrusion roller, and ironing by using an ironing wheel with the humidity of 40%.

2) Coating and solidifying: and uniformly coating the wet mixed solution on the pretreated base cloth, and then soaking the base cloth into an N, N-dimethylformamide aqueous solution with the concentration of 20% in a solidification tank for solidification.

3) Washing and drying: and extruding the excessive coagulating liquid through extrusion rollers after the coagulating is completed, washing with clear water through a washing tank, washing with water at the first stage of the washing tank, extruding through five groups of extrusion rollers, washing with water at the second stage through six groups of extrusion rollers, and finally drying, expanding and shaping to obtain the wet-process bass.

3. The dry process facing comprises the following steps:

1) Preparing a release paper coating: and (2) coating the dry mixed solution of (a) 2) on the release paper film in a zero clearance manner, drying the release paper film to be semi-dry through an oven, coating the dry mixed solution of (b) 2), and drying the release paper film to be semi-dry through the oven to obtain the release paper coating.

2) Dry process veneering: and (3) directly attaching the wet-process base on the release paper coating prepared in the step three 1) by using pressure, drying by using an oven, cooling by using a cooling roller, and respectively rolling the release paper and the wet-process base with the attached surface to obtain the finished leather.

4. Finishing the surface of finished leather: and printing the coating agent on the front surface of the finished leather by using three plates, and drying by using an oven to obtain the finished leather with the coating effect.

5. The finished leather graining treatment comprises the following steps:

1) Adding the softening agent into a water tank, and uniformly mixing;

2) Immersing the finished leather into the water solution passing through the water tank, dehydrating, rolling to dry, and kneading and drying by a kneading machine;

3) And finally, inspecting, rolling and packaging to obtain the synthetic leather material which is soft in hand feeling, strong in meat quality, good in strength, cheap and good.

The following provides specific examples of three proportions of the wet-process mixture of the soft synthetic leather:

the first embodiment is that the wet mixed material in the soft synthetic leather comprises the following components in parts by weight:

700 parts of solvent liquid of polyurethane resin with the modulus of 5kgf/c square meter wet method,

300 parts of polyurethane resin solvent liquid with the modulus of 10kgf/c square meter by wet method,

80 parts of soft organic silicon emulsion,

1200 parts of N, N-dimethylformamide,

300 parts of wood fiber powder.

At present, soft organic silicon is not introduced into the mixed slurry of the synthetic leather wet base, a polyether silicone oil leveling agent is used for reducing tension in the preparation of the mixed slurry of the synthetic leather wet base, a dimethyl silicone oil defoaming agent is used for defoaming, a diorganopolysiloxane flexibilizer is used for improving the flexibility of the resin after curing, and the using amount is very small. The organosilicon softener used in the after-finishing process has the organosilicon content of generally 8 percent, is added into a water texture-kneading water tank according to the usage amount of 3 percent, and the proportion of the attached organosilicon accounting for the bass is calculated to be 0.72 per thousand according to the liquid carrying rate of 30 percent; in this example, the specific gravity of the silicone adhered to the bass in the bass is about 4%, which is significantly much higher than that of the silicone in the post-finishing process, so that the softening effect of the silicone softener used in the wet mixture is much better than that of the silicone softener used in the post-finishing process.

The second embodiment: the wet mixing material for the soft synthetic leather comprises the following components in parts by weight:

300 parts of polyurethane resin solvent liquid with the modulus of 10kgf/c square meter wet method,

80 parts of soft organic silicon emulsion,

1200 parts of N, N-dimethylformamide,

300 parts of wood fiber powder, namely 300 parts of wood fiber powder,

125 parts of light calcium powder.

Example three: the wet mixture in the soft synthetic leather consists of the following components in parts by weight:

60 parts of soft organic silicon emulsion,

100 portions of polyvinyl alcohol powder

1200 parts of N, N-dimethylformamide,

250 parts of wood fiber powder.

In the proportion, the polyvinyl alcohol can provide compact micro-cells, and the inner walls of the micro-cells can adsorb the organosilicon softener, so that the produced bass is particularly soft; compared with the existing soft protein synthetic leather bass mixture, the amount of polyvinyl alcohol is greatly reduced, so that the blocking period of the polyvinyl alcohol in a solvent recovery system is greatly prolonged.

The following provides specific examples of two ratios of the organosilicon softening agent in the wet-process mixture of the soft synthetic leather:

example four: the organic silicon softening agent in the wet mixture in the soft synthetic leather consists of the following components in parts by weight:

60 parts of amino polyether block silicone oil;

9-18 parts of acetic acid, wherein the best is 12 parts;

ethylene glycol monobutyl ether and isopropanol 35-50 parts, wherein the optimal part is 40 parts;

35-185 parts of water and N, N-dimethylformamide, wherein the optimal part is 150 parts.

The amino polyether block silicon has excellent heat resistance stability and shearing resistance, not only keeps the softness and silky feeling of amino silicone oil, but also is not sticky and yellowing resistant, and can provide ideal moisture absorption and antistatic performance, and the leather after moisture absorption has a very drooping feeling.

Example five: the other proportion of the organic silicon softening agent in the wet method mixture in the soft synthetic leather is as follows:

60 parts of amino polyether block silicone oil;

9-18 parts of acetic acid, preferably 12 parts;

ethylene glycol monobutyl ether and isopropanol 35-50 parts, preferably 40 parts;

35-185 parts of N, N-dimethylformamide, and optimally 150 parts.

Wherein, butyl ether, isopropanol and N, N-dimethylformamide are used as solvents. The pigment paste in the wet mixed slurry has poor compatibility with water, and the peeling strength is influenced by excessive water in the wet mixed slurry, so that after the water in the mixture ratio is replaced by N, N-dimethylformamide, the pigment is not easy to run into the water when the wet mixed slurry is subjected to a water washing process in a coagulating tank, the base cloth is not easy to pollute the color, the peeling strength is improved, the softness is better, and the dispersion of the mixed slurry is facilitated.

Example six: the manufacturing process of the softening agent comprises the following steps:

1) Preparing amino polyether block silicone oil with 60 percent of organosilicon content,

the first step, addition reaction, the reaction temperature is about 70 ℃, the heat preservation time is about 5 hours, and the preparation method is prepared by the following raw materials by weight:

800 kg of terminal epoxy polyether silicone oil with the molecular weight of 8000,

96 kilograms of polyether is used for preparing the polyurethane resin,

the weight of the chloroplatinic acid is 12 g,

370 kg of isopropanol.

And step two, amination reaction is carried out, the reaction temperature is about 80 ℃, and the temperature is kept for about 8 hours. The health-care food is prepared from the following raw materials in parts by weight:

1266 kg of amino polyether block silicone oil with the organosilicon content of 60 percent is prepared in the first step,

20 kilograms of polyether amine is used as a raw material,

ethylene glycol monobutyl ether 240 kilograms.

2) Preparation of an amino polyether block silicone oil emulsion with 25% silicone content. The Bass softener can be obtained by emulsifying a stirred tank with a scrapping wall and a high shear, and the emulsified component materials are as follows:

1526 kg of amino polyether block silicone oil with the content of 60 percent of organosilicon,

180 kg of acetic acid is added to the mixture,

1956 kg of water.

Example six: the method is basically the same as the fifth embodiment except that: preparation of an amino polyether block silicone oil emulsion with 25% silicone content. The bass softener can be obtained by emulsifying a stirred tank with a scrapper and a high shear, and the emulsified component materials are as follows:

1526 kg of amino polyether block silicone oil with the content of 60 organic silicon,

180 kg of acetic acid is added to the mixture,

956 kg of water is added into the mixture,

1000 kg of N, N-dimethylformamide.

Example seven: the method is basically the same as the fifth embodiment except that: preparation of an aminopolyether block silicone oil solution with 25% silicone content. The Bass softening agent can be obtained by mixing and stirring and dispersing in a stirred tank with a scrapping wall and a high shear, and the mixed materials are as follows:

180 kg of acetic acid is added to the mixture,

1956 kg of N, N-dimethylformamide.

Further, an aminopolyether block silicone oil solution with 25% silicone content was prepared.

The bass softening agent can be obtained by mixing, stirring and dispersing in a stirred tank with a scrapper and a high shear, and the mixed materials comprise the following components:

180 kilograms of acetic acid is used for preparing the catalyst,

156 kilograms of polyvinyl alcohol (PVA) is added,

1800 kg of water.

Example eight: providing another proportion of the dry-process mixture of the soft synthetic leather, wherein the dry-process mixture comprises a dry-process outer-layer mixed solution and a dry-process inner-layer mixed solution, and comprises the following components in parts by weight:

the dry method outer layer mixed liquid is prepared from the following raw materials in percentage by weight:

40 parts of dry polyurethane resin with the modulus of 80kgf/c square meter,

30 parts of N, N-dimethylformamide,

21.8 parts of butanone, namely methyl ethyl ketone,

0.2 part of a leveling agent,

8 parts of toner.

The dry method inner layer mixed liquid is prepared from the following raw materials in percentage by weight:

30 parts of polyurethane resin with the modulus of 10kgf/c square meter dry method,

10 parts of polyurethane resin with the modulus of 15kgf/c square meter dry method,

30 parts of N, N-dimethylformamide,

21.5 parts of butanone, namely, methyl ethyl ketone,

0.2 part of a leveling agent,

0.3 portion of emulsifier AEO-3,

8 parts of toner.

Example nine: the softening agent and the wet polyurethane resin solvent solution in the wet bass process are proportioned into the wet polyurethane resin solvent solution with the softening agent. The wet-process polyurethane resin solvent solution with the softening agent comprises nonionic wet-process polyurethane resin, amino polyether block silicone oil, acetic acid and a solvent. Wherein the solvent is composed of butyl ether, isopropanol and N, N-dimethylformamide.

The preparation process of the wet-process polyurethane resin solvent liquid with the solid content of 30% and the softening agent comprises the following steps of mixing, stirring and dispersing by a stirring kettle with a high-speed disperser and a wall scraping function, wherein the stirring kettle comprises the following mixed materials:

1000 kg of 30 percent solid content nonionic wet-process polyurethane resin solvent solution,

100 kilograms of amino polyether block silicone oil with 60 percent of organic silicon content,

10kg of acetic acid is added into the mixture,

90 kg of N, N-dimethylformamide.

Because siloxane in the amino polyether block silicone oil is connected with a large amount of polyether, the nonionic wet polyurethane resin solvent liquid, the N, N-dimethylformamide and the cationic amino polyether block silicone oil are mixed together stably and can be stored for a long time.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The soft synthetic leather comprises base cloth, wet base and dry veneering, and is characterized in that: the wet base comprises polyurethane resin, organic silicon and filler, wherein organic silicon is attached to fiber micropores of the filler, micropores inside the polyurethane resin and gaps.

2. The soft synthetic leather of claim 1, wherein the weight ratio of polyurethane resin to silicone in the wet-process bass is 30:0.5-3.8.

3. A soft synthetic leather according to claim 2, wherein the silicone is 1 or 2 of amino silicone oil and amino polyether block silicone oil.

4. A soft synthetic leather as claimed in claim 1, 2 or 3, wherein the wet base is prepared from a wet mix applied to a base cloth, the wet mix comprising a polyurethane resin solution, a softening agent, N-dimethylformamide and a filler, the softening agent comprising silicone or a silicone-containing softening agent.

5. The soft synthetic leather of claim 4, wherein the ionic type of the softening agent is cationic, and the pH value of the silicone softening agent is less than 5.

6. A soft synthetic leather according to claim 5, wherein the silicone softener is an amino silicone oil emulsion or an amino polyether block silicone oil solvent solution or an amino polyether block silicone oil.

7. The soft synthetic leather of claim 5, wherein the silicone softener comprises amino polyether block silicone oil, acetic acid, and a solvent, wherein the weight ratio of amino polyether block silicone oil to acetic acid is 60:9-18.

8. The soft synthetic leather according to claim 6 or 7, wherein the molecular weight of the amino polyether block silicone oil is 5000-30000, and the amino polyether block silicone oil is formed by compounding 2 or more than 2 kinds of amino polyether block silicone oil with different molecular weights.

9. A soft synthetic leather according to claim 5, 6, 7 or 8, wherein the weight ratio of the polyurethane resin solvent solution to the silicone softener is 100:2-15.

10. The soft synthetic leather of claim 9, wherein the filler is one or more of wood fiber powder, pulp fiber powder and light calcium powder, and the wood fiber powder or the pulp fiber powder is high-swelling fiber powder, has a swelling rate of 17-25 and a mesh number of 350-700.