阅读说明：本技术 一种pu合成革的生产工艺 (production process of PU synthetic leather ) 是由 廖拯方 于 2019-07-25 设计创作，主要内容包括：本发明公开了一种PU合成革的生产工艺,其技术方案要点包括如下步骤：S1酸处理：将涤纶基布浸入酸处理液中,温度70-80℃,处理时间15-20min,然后在90-95℃下真空烘干；S2碱处理：将经过S1酸处理后的涤纶基布浸入碱处理液中,温度为75-85℃,处理时间30-40min,处理完成后水洗、烘干至恒重；S3亲水改性：将经过S2碱处理后的涤纶基布浸入改性液中,温度25-35℃,处理时间80-100min,处理完成后预烘干,再于130-140℃下焙烘2-3min,接着水洗、烘干,所述改性液包括5-7%丝素蛋白；S4浸渍；S5凝固。涤纶基布浸渍PU前经过丝素蛋白整理,使形成的PU涂层附着力好,不易剥离,使用寿命长。(The invention discloses a production process of PU synthetic leather, which has the technical scheme key points that the production process comprises the following steps: s1 acid treatment: soaking the terylene base cloth in an acid treatment solution at the temperature of 70-80 ℃ for 15-20min, and then drying the terylene base cloth in vacuum at the temperature of 90-95 ℃; s2 alkali treatment: soaking the terylene base cloth subjected to S1 acid treatment in an alkali treatment solution at the temperature of 75-85 ℃ for 30-40min, and washing and drying the terylene base cloth to constant weight after the treatment is finished; hydrophilic modification of S3: immersing the terylene base cloth subjected to the alkali treatment of S2 in a modification solution, wherein the temperature is 25-35 ℃, the treatment time is 80-100min, the terylene base cloth is pre-dried after the treatment is finished, then is baked at 130-140 ℃ for 2-3min, and is then washed with water and dried, and the modification solution comprises 5-7% of silk fibroin; s4 dipping; s5 is solidified. The silk fibroin is arranged before the polyester base cloth is soaked in PU, so that the formed PU coating has good adhesive force, is not easy to peel off and has long service life.)

1. A production process of PU synthetic leather is characterized by comprising the following steps:

s1 acid treatment: soaking the terylene base cloth in an acid treatment solution at the temperature of 70-80 ℃ for 15-20min, and then drying the terylene base cloth in vacuum at the temperature of 90-95 ℃;

S2 alkali treatment: soaking the terylene base cloth subjected to S1 acid treatment in an alkali treatment solution at the temperature of 75-85 ℃ for 30-40min, and washing and drying the terylene base cloth to constant weight after the treatment is finished;

Hydrophilic modification of S3: immersing the terylene base cloth subjected to the alkali treatment of S2 in a modification solution, wherein the temperature is 25-35 ℃, the treatment time is 80-100min, the terylene base cloth is pre-dried after the treatment is finished, then is baked at 130-140 ℃ for 2-3min, and is then washed with water and dried, and the modification solution comprises 5-7% of silk fibroin;

s4 dipping: soaking the polyester base fabric subjected to hydrophilic modification by S3 into PU dipping solution, and scraping redundant slurry;

s5 solidification: and (3) immersing the polyester base fabric soaked in the S4 into a solidification solution, taking out the polyester base fabric, washing with water, drying, and rolling to obtain the PU synthetic leather, wherein the solidification solution comprises 20-25% of DMF.

2. the production process of PU synthetic leather according to claim 1, characterized in that: the acid treatment solution comprises 8-10% of HCl and 6-9% of citric acid.

3. the production process of PU synthetic leather according to claim 2, characterized in that: the alkali treatment liquid comprises 6-8% of sodium hydroxide and 2-3% of sodium tert-butoxide.

4. the production process of PU synthetic leather according to claim 3, characterized in that: and the alkali treatment liquid also comprises 0.8-1.6% of ethylenediamine.

5. The production process of PU synthetic leather according to claim 1, characterized in that: the modified liquid also comprises 1-1.5% of amino silicone oil.

6. The production process of PU synthetic leather according to claim 1, characterized in that: the modifying solution also comprises 0.6-0.8% of cerium nitrate.

7. the production process of PU synthetic leather according to claim 1, characterized in that: the modified liquid also comprises 0.2-0.4% of penetrating agent JFC.

8. the production process of PU synthetic leather according to claim 1, characterized in that: the preparation process of the PU impregnating solution is as follows:

Firstly, mixing 22-28 parts of polypropylene oxide glycol and 26-30 parts of polyethylene glycol adipate-1, 4-butanediol glycol, heating to 100-105 ℃, and treating for 60-80 min;

Secondly, adding 20-23 parts of IPDI, 3-4 parts of dimethylolpropionic acid and 0.2-0.4 part of dibutyl tin dilaurate, heating to 85-90 ℃, and reacting for 2-3 h;

Thirdly, adding 2-3 parts of 1, 4-butanediol and 4-6 parts of N-methyl-2-pyrrolidone, reacting for 2-3 hours, cooling to 40-45 ℃, diluting with acetone during cooling, adding 2-3 parts of triethylamine, and uniformly stirring to obtain a polyurethane dispersion;

And fourthly, finally, adding 0.2-0.4 part of 15-20% PAMAM solution into the polyurethane dispersion, uniformly stirring, performing reduced pressure evaporation to remove acetone, and diluting with water to obtain the PU impregnation solution.

Technical Field

The invention relates to synthetic leather, in particular to a production process of PU synthetic leather.

background

artificial leather is a kind of plastic product with appearance and hand feeling similar to leather and capable of replacing it, and is produced by coating fabric as base with synthetic resin and various plastic additives. The artificial leather mainly comprises PVC artificial leather and PU synthetic leather, wherein the PU synthetic leather has the advantages of attractive appearance and good care and is an ideal substitute of natural leather.

Common production methods of PU synthetic leather include a dry method and a wet method. The dry process comprises the following steps: preparing PU resin into sol with certain solid content and certain viscosity, coating the sol on release paper serving as a carrier, heating the sol in an oven to volatilize a solvent so as to form a film, coating an adhesive layer on the film, compounding the adhesive layer with base cloth, drying, curing, cooling, then stripping the adhesive layer from the release paper, and finally carrying out processes such as printing treatment to obtain the synthetic leather. The wet process comprises the following steps: directly soaking the base cloth in the prepared PU resin, washing and curing the base cloth by DMF aqueous solution, washing the base cloth by hot water, and finally drying and post-treating the base cloth to obtain the PU synthetic leather.

Although the appearance of the PU synthetic leather is very close to that of genuine leather and has excellent cold resistance and aging resistance, the wear resistance of the PU synthetic leather relative to genuine leather is still poor, and the PU epidermis is easy to peel off after long-term use and needs to be improved.

Disclosure of Invention

aiming at the technical defects, the invention aims to provide a production process of PU synthetic leather, and the PU coating has high adhesive force and is not easy to peel off.

in order to achieve the purpose, the invention provides the following technical scheme:

a production process of PU synthetic leather comprises the following steps:

S1 acid treatment: soaking the terylene base cloth in an acid treatment solution at the temperature of 70-80 ℃ for 15-20min, and then drying the terylene base cloth in vacuum at the temperature of 90-95 ℃;

S2 alkali treatment: soaking the terylene base cloth subjected to S1 acid treatment in an alkali treatment solution at the temperature of 75-85 ℃ for 30-40min, and washing and drying the terylene base cloth to constant weight after the treatment is finished;

hydrophilic modification of S3: immersing the terylene base cloth subjected to the alkali treatment of S2 in a modification solution, wherein the temperature is 25-35 ℃, the treatment time is 80-100min, the terylene base cloth is pre-dried after the treatment is finished, then is baked at 130-140 ℃ for 2-3min, and is then washed with water and dried, and the modification solution comprises 5-7% of silk fibroin;

S4 dipping: soaking the polyester base fabric subjected to hydrophilic modification by S3 into PU dipping solution, and scraping redundant slurry;

s5 solidification: and (3) immersing the polyester base fabric soaked in the S4 into a solidification solution, taking out the polyester base fabric, washing with water, drying, and rolling to obtain the PU synthetic leather, wherein the solidification solution comprises 20-25% of DMF.

by adopting the technical scheme, after the terylene base cloth is subjected to S1 acid treatment, the surface of the terylene fiber is primarily damaged to form obvious micro-holes; after the alkali treatment of S2, the surface of the polyester fiber is etched by strong alkali, the micro-hole grooves are deepened, and a plurality of micro-holes which are mutually penetrated are generated on the surface and inside of the fiber; through S3 hydrophilic modification, silk fibroin is coated on the surface of polyester fiber in a crosslinking way, on one hand, the crosslinking performance of silk fibroin and polyurethane is good, and silk fibroin contains a large number of hydrophilic groups, so that the hydrophilicity of the surface of the polyester fiber is improved, the impregnation effect of impregnation liquid is conveniently improved, the crosslinking reaction range is widened, the adhesion effect of a PU coating is further improved, on the other hand, the polyester base cloth is softer and more elastic after finishing, and the hand feeling of synthetic leather is closer to that of real leather; and (3) forming a PU coating on the surface of the terylene base cloth by S4 dipping and S5 solidification.

the invention is further configured to: the acid treatment solution comprises 8-10% of HCl and 6-9% of citric acid.

by adopting the technical scheme, carboxyl is grafted on micro-holes of the polyester fiber, so that a protection effect is achieved, and the trouble that the mechanical property of the fabric is reduced due to the damage of S2 alkali treatment on the internal structure of the polyester fiber is avoided; meanwhile, the silk fibroin and the polyester fiber are combined.

The invention is further configured to: the alkali treatment liquid comprises 6-8% of sodium hydroxide and 2-3% of sodium tert-butoxide.

By adopting the technical scheme, the sodium tert-butoxide has good modification effect on the surface of the polyester fiber, but is easy to damage the internal structure of the polyester fiber as organic strong base, and the etching degree of the polyester fiber is controlled due to the protection of acid groups.

The invention is further configured to: the alkali treatment liquid also comprises 0.8-1.6% of ethylenediamine.

by adopting the technical scheme, the alkali amine has a synergistic effect during alkali treatment, and is beneficial to promoting the formation of deeper cracks and grooves.

The invention is further configured to: the modified liquid also comprises 1-1.5% of amino silicone oil.

by adopting the technical scheme, the amino silicone oil has good hydrophilicity.

The invention is further configured to: the modifying solution also comprises 0.6-0.8% of cerium nitrate.

By adopting the technical scheme, the cerium ions and the silk fibroin have a coordination relationship, so that the stability of the silk fibroin can be improved, the compactness of the molecular arrangement of the silk fibroin coating layer can be improved, and the adhesion performance of the silk fibroin coating layer and the adhesion performance of the PU coating layer can be improved; the cerium ions and the amino silicone oil have a coordination relationship, so that the stability of the cerium ions and the amino silicone oil is improved.

the invention is further configured to: the modified liquid also comprises 0.2-0.4% of penetrating agent JFC.

By adopting the technical scheme, the polyester base cloth can be favorably soaked by the modified liquid.

The invention is further configured to: the preparation process of the PU impregnating solution is as follows:

Firstly, mixing 22-28 parts of polypropylene oxide glycol and 26-30 parts of polyethylene glycol adipate-1, 4-butanediol glycol, heating to 100-105 ℃, and treating for 60-80 min;

Secondly, adding 20-23 parts of IPDI, 3-4 parts of dimethylolpropionic acid and 0.2-0.4 part of dibutyl tin dilaurate, heating to 85-90 ℃, and reacting for 2-3 h;

thirdly, adding 2-3 parts of 1, 4-butanediol and 4-6 parts of N-methyl-2-pyrrolidone, reacting for 2-3 hours, cooling to 40-45 ℃, diluting with acetone during cooling, adding 2-3 parts of triethylamine, and uniformly stirring to obtain a polyurethane dispersion;

and fourthly, finally, adding 0.2-0.4 part of 15-20% PAMAM solution into the polyurethane dispersion, uniformly stirring, performing reduced pressure evaporation to remove acetone, and diluting with water to obtain the PU impregnation solution.

By adopting the technical scheme, on one hand, the raw material of the polyalcohol has good hydrophilicity, the formed waterborne polyurethane has good dispersion in water, can easily soak the hydrophilic modified polyester base fabric, and has tighter crosslinking with silk fibroin; on the other hand, the wear resistance of the PU coating is improved by introducing the polyamide-amine dendritic polymer into the molecular structure of the waterborne polyurethane and utilizing the structural advantages of the polyamide-amine dendritic polymer.

In conclusion, the invention has the following beneficial effects:

1. The silk fibroin is finished before the polyester base cloth is soaked in PU, so that the formed PU coating has good adhesive force, is not easy to peel and has long service life;

2. The cross-linking degree of silk fibroin and the terylene base cloth is improved by acid treatment and alkali treatment before silk fibroin finishing of the terylene base cloth;

And 3, the PU dipping solution has excellent performance, and the prepared synthetic leather has good mechanical performance and hand feeling and is close to real leather.

drawings

fig. 1 is a schematic flow chart of the first to third embodiments.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.