Waterborne polyurethane adhesive for shoes and preparation method thereof

Abstract

The invention relates to waterborne polyurethane adhesive for shoes and a preparation method thereof. The waterborne polyurethane adhesive contains polyol, polyethyleneglycol adipate glycol, diisocyanate, diaminosulphonate, a secondary amine chain extender and monohydric alcohol amine. The waterborne polyurethane adhesive is characterized in that the polyol adopts at least one of poly-1,4-butyleneadipate glycols with the molecular weight of 4000, the molecular weight of the polyethyleneglycol adipate glycol is higher than 3000, and usage amount of the polyethyleneglycol adipate glycol is lessthan 3% of the total mass of the polyol; diisocyanate at least comprises two types, one type is aromatic diisocyanate and toluene diisocyanate, the other type is hexamethylene diisocyanate, and usageamount ratio of the two types is 1:2; usage amount of diaminosulphonate is slightly more than half of the usage amount of the toluene diisocyanate; amount of substance of the secondary amine chain extender is about 1 / 4 of the total amount of substance of diisocyanate; and the amount of substance of monohydric alcohol amine is about half of the total amount of substance of diisocyanate. The waterborne polyurethane adhesive for shoes has the advantages of good initial adhesive strength, crystallization property and heat resistance, low cost and stable product quality.

Description

technical field [0001] The invention belongs to the field of polymer materials, in particular to a water-based polyurethane adhesive and a preparation method. The invention is suitable for adhesives for shoes. Background technique [0002] my country is the world's largest producer, consumer and exporter of footwear, with an annual output of billions of pairs of footwear, accounting for more than 50% of the world's total footwear production. Zhejiang, Fujian, Guangdong, Shandong, Sichuan, Chengdu and other provinces have become the concentration places of the shoemaking industry, with more than 20,000 enterprises concentrated. 80% of the shoes produced need to use adhesives, and the amount of shoe glue used exceeds 200,000 tons . Shoe adhesives start from the first generation of neoprene adhesives, the second generation of grafted adhesives, the third generation of solvent-based polyurethane adhesives, and are now developing towards the fourth generation of water-based pol...

AI Technical Summary

Problems solved by technology

Its main disadvantage is that the viscosity of sodium 2-[(2-aminoethyl)amino]ethanesulfonate reacts with the chain-extended molecular chain of 1,4-butanediol to increase rapidly, and a large amount of acetone needs to be added to dilute it. , otherwise it will lead to emulsification failure, and the acetone added accounts for about 1.5-1.8 times of the polymer, which leads to the problem of acetone recovery and feeding cost; moreover, each batch of production can only produce about half of the feeding amount. , the rest are solvents such as methyl ethyl ketone and acetone removed by vacuuming, which brings great trouble to production and is also the main factor of low production efficiency; chain extension reaction under high viscosity is essential for the operation process of industrial production process The requirements are extremely high. If it is not well controlled, it will easily lead to problems such as emulsification failure or weakening or failure of the initial viscosity of the adhesive, resulting in low yield