The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 09, 1998
Filed:
May. 03, 1996
George F Cowperthwaite, Coatsville, PA (US);
Gary R Shaw, Norristown, PA (US);
Susan C Sheariss, Swedesboro, NJ (US);
Esschem, Inc., Linwood, PA (US);
Abstract
The disclosed method for making hollow shells (e.g. housing for in-ear hearing aids) employs a radiation-curable polymer comprising (a) a major amount of urethane methacrylate monomer (molecular weight 360-950) having a viscosity less than about 15,000 cps at 25.degree. C., (b) a viscosity-adjusting minor amount of unreacted hydroxyalkyl-methacrylate monomer, (c) a photoinitiating amount of a photoinitiator of the formula Ar.sup.1 --CO--C(OR).sub.2 --R', where Ar.sup.1 is aryl (e.g. phenyl), R is C.sub.1 -C.sub.4 -alkyl (e.g. methyl), and R' is hydrogen or alkyl or, preferably, aryl, and, optionally, (d) a coloring agent, e.g. a pigment concentrate. Viscosity control is of major importance; so the curable composition is generally solvent-free and free of viscosity-modifying solids (other than coloring agents). Acrylates (as distinct from methacrylates) are also omitted. The fully-formulated, curable composition is easily pourable and has a viscosity of less than about 2,000 cps. The hollow shells are made by: