Norwood Industries Inc.

Wilmington Chemical Corporation

W Raymond Bowditch

Borys Rybalka

MDI-based prepolymers are blown with a substantially nonaqueous blowing agent, such as pressurized air, and polymerized with stoichiometric amounts of polyoxyethylene polyol having at least two hydroxyl equivalents per mole, yielding a hydrophilic foam. The present foams may be extruded, knife-coated or otherwise cast into sheets, or may be fabricated by other known foam preparation techniques. Because the foam is polymerized with polyoxyethylene polyol instead of water, the foam exhibits both superior drape and improved stretch and recovery as compared with prior-art MDI-based flexible foams formed with aqueous reactants. The foam is particularly suited for use in external biomedical applications as, for example, a laminated medical/surgical dressing in which a thin sheet of the hydrophilic foam adheres to a nonstick aluminized veil on one side.

Hydrophilic foam

MDI-based prepolymers are blown with a substantially nonaqueous blowing agent, such as pressurized air, an polymerized with stoichiometric amounts of polyoxyethylene polyol having at least two hydroxyl equivalents per mole, yielding a hydrophilic foam. The present foams may be extruded, knife-coated or otherwise cast into sheets, or may be fabricated by other known foam preparation techniques. Because the foam is polymerized with polyoxyethylene polyol instead of water, the foam exhibits both superior drape and improved stretch and recovery as compared with prior-art MDI-based flexible foams formed with aqueous reactants. The foam is particularly suited for use in external biomedical applications as, for example, a laminated medical/surgical dressing in which a thin sheet of the hydrophilic foam adheres to a nonstick aluminized veil on one side.

A difunctional epoxide is provided which is represented by the structural formula: ##STR1## wherein Ar is an aromatic residue, a is 1 to 2, b is at least 2 and most preferably 2, and x is --CH.sub.3, --H, or --CH.sub.2 --CH.sub.3, and most preferably x is --CH.sub.3. In addition, an epoxy resin is provided which is comprised of the reaction product of the above diepoxide and a polyfunctional phenolic hydroxy compound represented by the structural formula: ##STR2## wherein Ar is an aromatic residue and m is at least and preferably 2. The resultant reaction product is at least difunctional in epoxide groups.

Low viscosity epoxy resins

A difunctional epoxide along with reaction products thereof is disclosed. The epoxide is represented by the structural formula: ##STR1## Improved epoxy resins prepared by the advancement reaction of the above epoxide with polyhydric phenols are also disclosed.

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West Chester, PA, United States of America

W Raymond Bowditch