Dicyandiamide-modified silicon phenolic resin adhesive and preparation method thereof

Abstract

The invention discloses a dicyandiamide-modified silicon phenolic resin adhesive and a preparation method thereof. The dicyandiamide-modified silicon phenolic resin adhesive is characterized by comprising the following raw materials: in parts by mass, 10-100 parts of a siloxane monomer, 0.05-4 parts of an acidic catalyst, 100 parts of a phenolic compound and 10-50 parts of dicyandiamide; in addition, the molar amount of aldehyde compounds to the phenolic compound is (0.5-1.0):1. The preparation method comprises the steps: mixing the siloxane monomer and the phenolic compound uniformly firstly,performing heating under the catalysis action of the acidic catalyst, performing a reaction so as to form an alkylphenoxysilane intermediate, then performing cooling, adding a certain amount of dicyandiamide and aldehyde compounds, performing a reaction with the alkylphenoxysilane intermediate at a certain temperature until the end point of the reaction, performing reduced pressure distillation,and performing vacuum drying so as to obtain the dicyandiamide-modified silicon phenolic resin adhesive. The resin adhesive exhibits high heat resistance and flexibility due to introduction of a flexible long-molecular chain and high-polarity heat-resistant groups of cyano groups.

Description

technical field [0001] The invention relates to the technical field of adhesives, in particular to a dicyandiamide-modified silicon phenolic resin adhesive and a preparation method thereof. Background technique [0002] Phenolic resin adhesives have high bonding strength, easy to obtain raw materials, simple synthesis process, and high mechanical strength of the resin after curing. They are used in various fields closely related to the national economy. However, due to the easy oxidation of phenolic hydroxyl groups and methylene groups in the molecular structure of traditional phenolic resin adhesives, the heat resistance is affected, which limits its application in certain fields, especially high-temperature fields. [0003] In order to improve the thermal stability of the phenolic resin adhesive, silicon atoms are introduced into the macromolecular structure of the phenolic resin to partially block the phenolic hydroxyl groups, and at the same time form Si-O bonds (460kJ / m...

AI Technical Summary

Problems solved by technology

However, the preparation process of traditional silicone phenolic resin adhesives is complicated, and there are reactions such as hydrolysis and self-polymerization of silicone monomers, phenolic self-polymerization, and monomer-phenolic copolymerization, and the degree of reaction polymerization is difficult to control.

[0004] The present inventor has synthesized and prepared a novel silicon phenolic resin adhesive (SPF) by transesterification in the previous research, which has solved the problem that the reaction process is difficult to control in the preparation process of the above silicon phenolic resin adhesive; yet, prepared The toughness of the new silicone phenolic resin adhesive is not enough, and the industrial production is not enough, and its toughness needs to be further improved

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