Viscosity modifier for thermosetting resin composition
AssigneeThe Dow Chemical Company
InventorJoseph Gan
Life of this patent
Estimating the term…
Abstract
A heat curable thermosetting epoxy resin formulation useful for making prepregs and electrical laminates containing a viscosity modifier, wherein the viscosity modifier is: (a) an optionally substituted polymer of a monovinylidene aromatic monomer, optionally having one or more further unsaturated monomers copolymerized therewith; (b) an optionally substituted polyphenylene oxide; or (c) an oxazolidone ring-containing compound.
Claims25
A thermosetting resin composition comprising a heat-curable thermosetting resin having a molecular weight of from about 200 to about 3000, and from about 0.5 to about 40 percent by weight, based on the resin composition, of a viscosity modifier which is a thermoplastic resin having a molecular weight of at least about 5000 and a hydroxyl content not exceeding about 0.2 hydroxyl equivalents per 100 g of the resin composition, said viscosity modifier used as a viscosity modifying additive to control the viscosity characteristics and flow characteristics of the heat-curable thermosetting resin while maintaining an adequate Tg in a final cured resin resulting from curing the heat-curable thermosetting resin;
- wherein the viscosity modifier is an oxazolidone ring-containing compound having a Tg of at least 86° C. which is the reaction product of:
- a) a polyisocyanate having an isocyanate functionality of from about 1.9 to about 2.1;
- b) a polyepoxide having an epoxide functionality of from about 1.9 to about 2.1;
- and optionally,
- c) a chain extender.
A method of preparing a thermosetting resin composition, which method comprises combining a heat-curable thermosetting resin having a molecular weight of from about 200 to about 3000, with from about 0.5 to about 40 percent by weight, based on the resin composition, of a viscosity modifier wherein the viscosity modifier is a thermoplastic resin having a molecular weight of at least about 5000 and a hydroxyl content not exceeding about 0.2 hydroxyl equivalents per 100 g of the resin composition, said viscosity modifier used as a viscosity modifying additive to control the viscosity characteristics and flow characteristics of the heat-curable thermosetting resin while maintaining an adequate Tg in a final cured resin resulting from curing the heat-curable thermosetting resin;
- wherein the viscosity modifier is an oxazolidone ring-containing compound having a Tg of at least 86° C. which is the reaction product of:
- a) a polyisocyanate having an isocyanate functionality of from about 1.9 to about 2.1;
- b) a polyepoxide having an epoxide functionality of from about 1.9 to about 2.1;
- and optionally,
- c) a chain extender.
A process for preparing a cured thermoset resin, which process comprises heating and thereby curing a thermosetting resin composition comprising a heat-curable thermosetting resin having a molecular weight of from about 200 to about 3000, and from about 0.5 to about 40 percent by weight, based on the resin composition, of a viscosity modifier which is a thermoplastic resin having a molecular weight of at least about 5000 and a hydroxyl content not exceeding about 0.2 hydroxyl equivalents per 100 g of the resin composition, said viscosity modifier used as a viscosity modifying additive to control the viscosity characteristics and flow characteristics of the heat-curable thermosetting resin while maintaining an adequate Tg in a final cured resin resulting from curing the heat-curable thermosetting resin;
- wherein the viscosity modifier has a Tg of at least 86° C. and is the reaction product of:
- a) a polyisocyanate having an isocyanate functionality of from about 1.9 to about 2.1;
- b) a polyepoxide having an epoxide functionality of from about 1.9 to about 2.1;
- and optionally,
- c) a chain extender.
Dependencies are inferred from the claim text.