Low-melting-point copolyamide hot melt adhesive for clothes and processing method thereof

Abstract

The invention discloses a low-melting-point copolyamide hot melt adhesive for clothes. The hot melt adhesive is prepared from the following raw materials in percentage by weight: 30-40% of dibasic acid or dibasic acid salt, 20-30% of diamine or diamine salt, 20-40% of lactam, 1-8% of a molecular weight modifier, 0.1-0.4% of a stabilizer and 2-6% of water. A processing method for the low-melting-point copolyamide hot melt adhesive comprises the following steps: adding the raw materials into a reaction still, pumping 0.1 Mpa of nitrogen, then slowly emptying to normal pressure, repeatedly replacing to completely remove air in the reaction still, increasing the temperature of the reaction still to 220-250 DEG C, enabling the pressure to be 1.0-1.8 Mpa, reacting for 1.5-3 hours, cooling to 170-190 DEG C, reducing the pressure to 0.003-0.1 Mpa, dehydrating, and discharging to obtain the polyamide hot melt adhesive of which the average molecular weight is 12,000-100,000, the opening time is 1.0-3.0 min, and the melting point is 80-90 DEG C. The hot melt adhesive provided by the invention has the benefits that the melting point is low, the opening time is short, the melting range is short and the wash durability is better.

Description

technical field [0001] The invention relates to a copolyamide hot-melt adhesive for clothing and a preparation method thereof, in particular to a low-melting copolyamide hot-melt adhesive and a preparation method thereof. Background technique [0002] Polyamide resin was invented by DuPont (DuPont) in the United States. It is a linear thermoplastic polymer containing amide groups-CONH-repeating structural units in the main chain generated by carboxylic acids and amines. Its chemical structural formula can be expressed as ( - CO-R-CO-NH-R'-NH-)n. Through modification, polyamide hot melt adhesives with excellent performance can be obtained. Its outstanding advantages are narrow range of softening point, solidification immediately when the temperature is slightly lower than the melting point, good oil resistance and chemical resistance. And because the molecule contains polar groups such as amino, carboxyl and amide groups, it has good cementing performance for many polar m...

AI Technical Summary

Problems solved by technology

Although there are domestic and foreign patents on polyamide hot melt adhesives with a melting point lower than 100°C, there are some insurmountable shortcomings, such as some with too low softening point, some with low strength, some with poor washing and dry cleaning resistance, and open long wait

[0004] Chinese patent 201010288005 proposes a polyamide hot-melt adhesive made by the reaction of unsaturated aliphatic dimer acid and aliphatic dicarboxylic acid, aliphatic diamine, polyether amine and heterocyclic diamine, but its melting point higher;

[0005] U.S. Patent US3987678 invented a polyamide hot-melt adhesive formed by polycondensation of caprolactam, hexamethylenediamine, arbitrary diamine, and sebacic acid, which has a high melting point and high peel strength; but the washing resistance is general, five The strength decreased by 33.7% after the first washing;