A process for preparing curing agents for curing glycidyl ethers, the resulting curing agents, their use and the resulting products

摘要

A curing agent for a glycidyl ether of a polyhydric alcohol or phenol is prepared by reacting the glycidyl ether of a dihydric phenol with at least 1.5 mols. of a secondary amine containing a single nitrogen atom per epoxide group in the glycidyl ether. The secondary curing agents thus produced are soluble in organic solvents compatible with other glycidyl ethers and free from the odour of amine. The preferred glycidyl ether for making the secondary curing agent is that of 2, 2 bis (4-hydroxyphenyl) propane. It is preferably heated with the amine at 50-150 DEG C. The glycidyl ether may be melted or dissolved to facilitate reaction with the amine. Amines mentioned are diethylamine, dimethylamine, and piperidine. Examples describe the preparation of secondary curing agents and their use for curing various glycidyl ethers as films, adhesives, or glass cloth laminating compositions. The ether used for making the secondary curing agent need not be the same as the ether which is cured. In some examples mixed ethers from a polyhydric phenol and a polyhydric alcohol are cured. Specification 691,543 is referred to.ALSO:Materials which may be used to cure glycidyl ethers of polyhydric alcohols or phenols to hard infusible bodies (see Group IV (a)) are made from at least 1.5 (preferably 2-5) mols. of a secondary amine reacted with one mol. of a glycidyl ether of a dihydric phenol, preferably 2, 2-bis (4-hydroxyphenyl)-propane. The products are soluble in a variety of organic solvents and compatible with the glycidyl ethers to be cured. They are free from the odour of amine. Preferably the reactants are heated to 50-150 DEG C. but reaction may take place at room temperature. Super-atmospheric pressure may be employed especially with a low boiling amine such as dimethylamine. The amine is thought to react with the epoxy group to form 3-amino-2-hydroxypropyl or 2-amino-3-hydroxypropyl group-the amino residue being tertiary. Unreacted excess amine is removed from the products. The reactants may be melted or dissolved to facilitate mixing. Examples describe the preparation of products from the reaction of glycidyl ethers prepared from epichlorhydrin and 2, 2-bis (4-hydroxyphenyl) (Mol. wt. 325-650) with dimethylamine, diethylamine and piperidine. Specification 691,543, [Group IV(a)], is referred to.