Method for preparing solvent-free wet-process foaming polyurethane for synthetic leather and method for preparing synthetic leather by using solvent-free wet-process foaming polyurethane

A foamed polyurethane, solvent-free technology, applied in the field of synthetic leather, can solve the problems of DMF residue and product safety, and achieve the effect of low cost and simple process

Inactive Publication Date: 2013-05-08
SHAANXI UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The invention provides a method for preparing a solvent-free wet-process foamed polyurethane for synthetic leather with a simple process and low cost and a m

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] In terms of parts by mass, add 40 parts of polyether diol into the reaction kettle, dehydrate at 110°C and a vacuum of 133.3Pa for 1.5 hours, then cool to 50°C, and add 75 parts of toluene diisocyanate into the reaction kettle and 0.16 parts of dibutyltin dilaurate, and reacted at 75°C for 2 hours to obtain an isocyanate-terminated polyurethane prepolymer, that is, a solvent-free wet foaming polyurethane; wherein, the isocyanate group in toluene diisocyanate and polyether diol The molar ratio of hydroxyl groups in is 1.5.

[0018] The method for preparing synthetic leather by using the solvent-free wet-process foaming polyurethane is as follows: immerse the non-woven fabric in the solvent-free wet-process foaming polyurethane, so that the solvent-free wet-process foaming polyurethane is filled into the non-woven fabric, and then enter the 55 ° C Stay in the water bath for 5 minutes to solidify the solvent-free wet foamed polyurethane and form a porous polyurethane fille...

Embodiment 2

[0020] In terms of parts by mass, add 20 parts of polyester diol into the reaction kettle, dehydrate at 110°C and a vacuum of 133.3Pa for 1.5 hours, then cool to 40°C, and add 45 parts of isophor to the reaction kettle Ketone diisocyanate and 0.05 parts of stannous octoate were reacted at 60°C for 3 hours to obtain an isocyanate-terminated polyurethane prepolymer, that is, a solvent-free wet-process foaming polyurethane; wherein, the isophorone diisocyanate isocyanate group and The molar ratio of the hydroxyl groups in the polyester diol was 1.8.

[0021] The method for preparing synthetic leather by using the solvent-free wet-process foaming polyurethane is: using a scraper coater to scrape-coat the solvent-free wet-process foaming polyurethane on the nonwoven fabric, so that the solvent-free wet-process foaming polyurethane is formed on the nonwoven fabric. Then enter the water bath at 25°C and stay for 15 minutes to solidify the solvent-free wet foaming polyurethane and for...

Embodiment 3

[0023] In terms of parts by mass, add 35 parts of polyester diol into the reactor, dehydrate at 110°C and a vacuum of 133.3Pa for 1.5 hours, then cool to 25°C, and add 90 parts of diphenyl A mixture of methylene diisocyanate and 0.2 parts of dimethylethanolamine and stannous octoate was reacted at 85°C for 1 hour to obtain an isocyanate-terminated polyurethane prepolymer, that is, a solvent-free wet-process foaming polyurethane; wherein, diphenyl The molar ratio of the isocyanate groups in the methylene diisocyanate to the hydroxyl groups in the polyester diol was 2.5.

[0024] The method of preparing synthetic leather by using the solvent-free wet foaming polyurethane is: immerse the textile cloth in the solvent-free wet foaming polyurethane, so that the solvent-free wet foaming polyurethane is filled into the textile cloth, and then enter the water bath at 30 °C Stay for 8 minutes to solidify the solvent-free wet-process foamed polyurethane and form a porous polyurethane fil...

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PUM

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Abstract

The invention provides a method for preparing solvent-free wet-process foaming polyurethane for synthetic leather and a method for preparing the synthetic leather by using the solvent-free wet-process foaming polyurethane. The method for preparing the solvent-free wet-process foaming polyurethane comprises the steps of: dewatering polyalcohol, adding isocyanate and a catalyst in a reaction kettle at the temperature of 25-50 DEG C and reacting the temperature of 55-85 DEG C, thus obtaining the solvent-free wet-process foaming polyurethane. The method for preparing the synthetic leather comprises the steps of: filling the solvent-free wet-process foaming polyurethane in a non-woven fabric by soakage or forming a film on the non-woven fabric by blade coating; and putting the non-woven fabric in a water bath for solidifying the solvent-free wet-process foaming polyurethane and generating carbon dioxide gas, thus forming a porous polyurethane filler in the non-woven fabric or a porous polyurethane coating layer on the surface of the non-woven fabric, and finally obtaining various types of polyurethane synthetic leather by adopting a conventional processing technology. By virtue of the method, the pollution problem of a DMF (Dimethyl Formamide) solvent in the current wet-process solidification technology of a solvent type polyurethane synthetic leather can be solved; and in addition, the solvent-free wet-process foaming polyurethane belongs to a self-foaming product and is low in preparation cost and simple in technology.

Description

technical field [0001] The invention belongs to the field of synthetic leather, and in particular relates to a preparation method of a solvent-free wet-process foamed polyurethane for synthetic leather and a method for preparing synthetic leather by using a solvent-free wet-process foamed polyurethane. Background technique [0002] At present, the production of polyurethane synthetic leather mainly adopts a solvent-based production system, in which the foamed coating is obtained by a wet coagulation process. Washed and dried. Using this method to obtain a foamed polyurethane coating, there are the following major technical problems: First, the solvent-based polyurethane (PU) slurry is coated on the surface of the non-woven fabric with a scraper coater or a roller coater, Then enter the "H 2 O-DMF (dimethylformamide)" coagulation bath, which solidifies PU to form a film with a microporous structure. DMF is used as a solvent in this process, and the processing process will c...

Claims

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Application Information

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IPC IPC(8): C08G18/48C08G18/42C08J9/08C08L75/06C08L75/08D06N3/14
Inventor 马兴元吴泽胡雪丽
Owner SHAANXI UNIV OF SCI & TECH
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