The Dow Chemical Company

Zeng-Kun Liao

Chun S Wang

Dennis L Steele

Epoxy resins which are relatively low in total bound halide are prepared by concurrently and continuously adding a mixture of (1) a mixture of an epihalohydrin, a compound containing an average of more than one group reactive with a vicinal epoxide group and a solvent and (2) an aqueous or organic solution of an alkali or alkaline earth metal hydroxide; to (3) a mixture of epihalohydrin and a solvent.

Concurrent addition process for preparing high purity epoxy resins

The total halide content of epoxy resins is reduced by heating a resin containing undesirable halide dissolved in a solvent mixture containing at least one polar aprotic solvent in the presence of an alkali metal hydroxide for a time sufficient to reduce the total halide content.

Method for reducing the aliphatic halide content of epoxy resins using a

Glycidyl derivatives of compounds containing --OH, --NH.sub.2 and/or --COOH groups are prepared by reacting in the presence of a mixture of solvents, at least one of which is a polar aprotic solvent, an excess of an epihalohydrin with a compound containing --OH, --NH.sub.2 and/or --COOH groups while continuously or incrementally adding an alkali metal hydroxide to the mixture and removing water from the reaction by codistillation with epihalohydrin and the solvents.

Preparation of epoxy resins having low undesirable halogen content

The aromatic hydroxyl groups of aromatic hydroxyl-containing compounds can be allylated to greater than 95% conversion by reacting the alkali metal salt of said aromatic hydroxyl-containing compounds with an allyl halide such as allyl chloride in the presence of a polar aprotic solvent such as dimethylformamide. These compounds are useful in preparing epoxy resins containing a low halogen content.

Method for allylating aromatic hydroxyl-containing compounds

Monomers and oligomers containing a plurality of vinylbenzyl ether groups are prepared by reacting a material containing a plurality of aromatic hydroxyl groups such as tetramethyltetrabromobisphenol A with a vinylbenzyl halide such as vinylbenzyl chloride in the presence of a polar aprotic solvent such as dimethylformamide. The monomers and oligomers prepared by this process have an improvement in one or more properties selected from dielectric constant (before and/or after moisture absorption) or thermal stability. Also disclosed are new monomers and oligomers containing a plurality of vinylbenzyl ether groups such as bis(vinylbenzyl)ether of dicyclopentadienyl bisdimethylphenol.

Growing community of inventors

Lake Jackson, TX, United States of America

Zeng-Kun Liao