Synthetic leather adhesive and preparation method

Abstract

The invention provides a synthetic leather adhesive and a preparation method thereof. The synthetic leather adhesive is mainly prepared from raw materials such as polyol, diisocyanate, catalyst, epoxy resin and the like. The present invention uses epoxy resin to chemically modify water-based polyurethane, introduces a higher degree of branching of epoxy resin into the main chain of polyurethane, and improves the initial viscosity, peel strength, drying speed and water resistance of the dispersion coating film . The adhesive for synthetic leather prepared by the invention has good environmental protection, and the dispersion liquid has high initial tack, good peel strength, fast drying speed, excellent water resistance, and excellent leveling and spreading properties. It satisfies the conditions of use of adhesives for synthetic leather.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a synthetic leather adhesive and a preparation method. Background technique [0002] The composite product of the coating produced with polyurethane resin as raw material is called "synthetic leather". The emergence of synthetic leather makes up for the lack of leather resources and is the most promising substitute for natural leather. PU resin is used as the base layer and surface layer material for the production of synthetic leather. Solvent-based polyurethane adhesives, due to the use of a large amount of organic solvents, not only pollute the environment, but also cause harm to the health of workers in related industries, and are flammable and explosive. It is very easy to cause fire accidents, and the use of organic solvents has caused a great waste of resources. Therefore, it is imperative for the polyurethane synthetic leather industry to eliminate pollution from the sour...

AI Technical Summary

Problems solved by technology

[0005] Chinese patent CN103450837A discloses a method for preparing a water-based polyurethane adhesive for synthetic leather: the polyols used in the formula are all polytetrahydrofuran ether diols with an average relative molecular weight of 1000±50 and a hydroxyl value of 105-120 mgKOH / g. Although the water resistance of the adhesive is relatively good, the polyol used as the adhesive has a low molecular weight, which will cause insufficient initial tack and peel strength of the final product synthetic leather, thus affecting the performance quality of the synthetic leather

[0006] Chinese patent CN103450837A discloses a high-solid content water-based polyurethane resin and its synthesis method: in order to adapt to the production process of synthetic leather, the drying speed is accelerated by increasing the solid content of the emulsion, and the initial tack is improved, but the method of increasing the solid content is greatly improved. The production cost is increased, and NMP solvent is also used in the formula, which does not meet the requirements of complete environmental protection

[0007] Chinese patent CN101717488A discloses an epoxy resin modified water-based PU emulsion and its preparation method. Although the water-based PU has been modified by utilizing the excellent properties of epoxy resin, there are many defects in the formula: such as polyols using poly Ester polyol 210N or 220N. As we all know, polyester polyol 210N and 220N are not resistant to hydrolysis. The water-based PU emulsion made of this raw material has extremely poor stability when placed. After a few months or half a year, the performance of the emulsion and film will be seriously degraded; Moreover, the water resistance of the modified water-based PU film has only dropped from 49.8% to 12.3%, which completely fails to meet the requirements of water-based adhesives for synthetic leather.

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