The Dow Chemical Company

Jody R Berman

Louis L Walker

Chun S Wang

Abel Mendoza

James L Bertram

Dennis L Steele

Dale J Aldrich

Jerry E White

H Craig Silvis

Avis L McCrary

Ross C Whiteside, Jr

Robert L Bowden

Paul A Larson

James A Clarke

Wuu N Chen

Michael P Kubisiak

Christine C Berkefelt

Advanced epoxy resins are disclosed which result from the reaction of a relatively low molecular weight epoxy resin and a polyhydric phenol wherein at least one of the reactants contains at least one halogen atom which is meta with respect to a glycidyl ether group or a hydroxyl group attached to an aromatic ring. These advanced epoxy resins, when cured with a suitable curing agent, possess an improvement as compared to an advanced epoxy resin containing halogen atoms which are ortho with respect to a glycidyl ether group in at least one of thermal stability, glass transition temperature, relationship of viscosity to molecular weight and resistance to forming hydrolyzed halides in the presence of a refluxing solution of an alkali metal hydroxide.

Halogenated advanced epoxy resins

Electrical laminates are prepared from prepreg materials prepared by impregnating a substrate with a laminating varnish comprising a ketone solvent solution of a curable composition comprising (A) at least one aromatic based epoxy resin having an average number of epoxide groups per molecule of more than 2; (B) a mixture of (1) at least one phenolic hydroxyl-containing compound having an average of more than 1 but not more than 2 phenolic hydroxyl groups per molecule; and (2) at least one phenolic hydroxyl-containing compound having an average of more than 2 phenolic hydroxyl groups per molecule; and (C), optionally, at least one catalyst for effecting the reaction between (A) and (B).

Curable compositions containing an epoxy resin, a difunctional phenol

An improvement in curable compositions which comprise a polyglycidyl ether such as the triglycidylether of tris(hydroxyphenyl)methane and a halogenated dihydric phenol such as tetrabromobisphenol A, the improvement being employing as the halogenated dihydric phenol one in which the halogen atoms are meta with respect to the hydroxyl groups such as 2,2',6,6'-tetrabromo-3 ,3',5,5'-tetramethyl-4,4'-biphenol. These compositions can be cured by heating in the presence or absence of a catalyst for reacting epoxy groups with phenolic hydroxyl groups such as 2-methyl imidazole. These compositions are particularly useful in the preparation of electrical laminates.

Curable compositions containing a polyepoxide and a halogenated bisphenol

Compositions comprising (A) a halogenated phenoxy resin and (B) an advanced epoxy resin are useful in the preparation of electrical laminates when admixed with a suitable curing agent such as dicyandiamide.

Epoxy resin laminating varnish and laminates prepared therefrom

Halogenated aromatic epoxy resins are disclosed wherein the halogen atoms are in the meta position with respect to a glycidyl ether group attached to an aromatic ring. Advanced epoxy resins are disclosed which result from the reaction of a relatively low molecular weight epoxy resin and a polyhydric phenol wherein at least one of the reactants contains at least one halogen atom which is meta with respect to a glycidyl ether group or a hydroxyl group attached to an aromatic ring. These advanced epoxy resins, when cured with a suitable curing agent, possess an improvement as compared to an advanced epoxy resin containing halogen atoms which are ortho with respect to a glycidyl ether group in at least one of thermal stability, glass transition temperature, relationship of viscosity to molecular weight and resistance to forming hydrolyzed halides in the presence of a refluxing solution of an alkali metal hydroxide.

Halogenated epoxy resins

Advanced epoxy resin products are prepared by reacting a triglycidyl ether of a trihydric phenol such as the triglycidyl ether of 1,1,1-tri(hydroxyphenyl)methane with a dihydric phenol such as bisphenol A. These advanced epoxy resins are non-sintering solid resins useful in the preparation of electrical potting or molding compositions.

Advanced epoxy resins prepared from triglycidyl ethers and dihydri

Polyhydroxyethers formed by reacting a diglycidyl ether of biphenol, such as diglycidyl ethers of bisphenol-A, and a dihydroxybiphenyl, such as dihydroxybiphenyl, tetramethyldihydroxybiphenyl, and tetrabromotetramethyldihydroxybiphenyl, exhibit high heat distortion temperatures. These compositions could find utility in extruded films, packaging and coatings.

Polyhydroxyethers from hydroxybiphenyls

Curable compositions are disclosed which comprise a multiglycidyl ether such as the triglycidylether of tris(hydroxyphenyl)methane and an amine substituted sulfonic acid amide such as sulfanilamide. These compositions can be cured by heating in the presence or absence of an accelerator such as 2-methyl imidazole. These compositions are particularly useful in the preparation of electrical laminates.

Curable compositions containing multiglycidyl ethers and a sulfonic acid

Curable compositions are disclosed which comprise a polyglycidyl ether such as the triglycidylether of tris(hydroxyphenyl)methane and a halogenated dihydric phenol such as tetrabromobisphenol A. These compositions can be cured by heating in the presence or absence of catalyst for reacting epoxy groups with phenolic hydroxyl groups such as 2-methyl imidazole. These compositions are particularly useful in the preparation of electrical laminates.

Relatively high molecular weight epoxy resins cured with conventional curing agents are disclosed wherein the relatively high molecular weight epoxy resin is prepared in the presence of the curing agents. The resultant cured epoxy resin has an improvement in Tg or toughness and the mixture prior to reaction and curing is much easier to apply as a coating or in the preparation of castings, laminates and the like as compared to applications of mixtures of relatively high molecular weight epoxy resins and the curing agents.

Curable, partially advanced epoxy resins

Resin compositions are prepared by reacting an epoxy resin with an amine-substituted aromatic sulfonic acid amide at a temperature up to about 130.degree. C. The resultant product can be cured by heating to a temperature of at least about 150.degree. C. in the presence of suitable curing agents and in some instances in the absence of any curing agent.

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Lake Jackson, TX, United States of America

Jody R Berman