Method for synthesizing dimer acid type polyamide hot melt adhesive

Abstract

The invention discloses a method for synthesizing a dimer acid type polyamide hot melt adhesive. The polyamide hot melt adhesive is prepared by adding a catalyst, an aqueous solution of alcohol and an aid into monomers of dimer acid, aliphatic dicarboxylic acid and aliphatic diamine which are taken as reaction raw materials and performing condensation reaction. The method is easy to operate, the loss of amine in the reaction process is low, and the chemical equivalent can be controlled easily, so that the reaction is more complete, and finally a product with stable high molecular weight can be obtained; meanwhile, the deviation among different batches of products can also be improved, so that the product can be stably produced.

Description

technical field [0001] The invention relates to a synthesis method of dimer acid type polyamide hot melt adhesive, which is especially suitable for preparing dimer acid type polyamide hot melt adhesive with high reaction degree. Background technique [0002] Dimer acid polyamide hot melt adhesive is a kind of dimeric unsaturated aliphatic or partially substituted dimer unsaturated fatty acid and aliphatic diamine through polycondensation reaction. [0003] Chinese patent CN1357589A discloses a method of synthesizing component A by partially substituted dimer acid and diamine in the presence of a modifier and a catalyst; The basic acid and the diamine synthesize component B under high pressure conditions, and finally mix component A and component B in a certain proportion. [0004] Chinese patent CN1415686A discloses a solution in which an aliphatic diamine is formulated into an aqueous solution and reacted with an aliphatic dibasic acid to finally generate a polyamide hot m...

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Problems solved by technology

[0006] There are some deficiencies in the preparation methods of polyamide hot-melt adhesives mentioned in the above-mentioned patents. Patent CN1357589A needs to synthesize components A and B respectively, and then blend them. The synthesis process is relatively complicated, resulting in product batches. The difference between times is bigger; patent CN1415686A uses the aqueous solution of amine as reaction raw material, causes like this to limit to the raw material used in reaction, because the compatibility of dimer acid and water is poor, so this method is not suitable for Synthesis of dimer acid type polyamide hot melt adhesive; patent CN1763145A puts all the reaction raw materials (dibasic acid and diamine) into the reactor for synthesis in advance, so that when using lower boiling point diamines for synthesis, It will cause part of the amine to be lost due to volatilization, which will eventually affect the ratio of acid to amine. It is not suitable for the preparation of polyamide hot melt adhesives with a high degree of reaction.

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