Hot melt adhesive composition that melts at relatively low temperatures
AssigneePearle, Inc.
InventorsPascal E. Esemplare, Ronald W. Gumbs
Life of this patent
Estimating the term…
Abstract
Novel lower temperature hot melt adhesive and coating composition that melts at temperatures less than 190.degree. F. (about 87.8.degree. C). This composition has a sufficient modulus to bind ophthalmic lenses to metal blocks during grinding processes. The composition also exhibits low melt viscosity and may be mechanically removed without leaving significant residue. Composition comprises a resin, a tackifier, a wax (generally with a molecular weight less than 600), and an optional stabilizer.
Claims43
A method of mounting an ophthalmic lens for grinding, which comprises:
- mounting the lens on a block such that a cavity results between the block and the lens;
- filling the cavity between the lens and the block with a liquid hot melt adhesive at a temperature less than 190.degree. F. (87.8.degree. C.), the hot melt adhesive comprising 15-30 weight percent of a resin having a melt index of 300-500 dg/min per ASTM D1238, 15-30 weight percent of a wax having a Ring and Ball softening temperature between about 135.degree.-160.degree. F. (about 57.degree.-71.degree. C.), and 40-60 weight percent of a tackifier, and wherein the adhesive is strong enough to bind the lens to the block during grinding of the lens;
- cooling the adhesive sufficient to bond the lens to the block.
A hot melt adhesive composition, comprising:
- 15-30 weight percent of a resin having a melt index of 300-50 dg/min per ASTM D1238;
- 1- 30weight percent of a wax having a Ring and Ball softening temperature between about 135.degree.-160.degree. F. (about 57.degree.-71.degree. C.), a molecular weight of less than 600, and a melt viscosity of 100-50 cp at 150.degree. F. (about 66.degree. C.);
- 40-60 weight percent of a tackifier;
- and
- the composition being tacky, having a Ring and Ball softening temperature less than 190.degree. F. (87.8.degree. C.),
- and being sufficiently strong and adhesive to bind an ophthalmic lens to a substrate during grinding of the lens.
A hot melt adhesive composition, consisting essentially of:
- 15-30 weight percent of a resin having a melt index of 300-500 dg/min per ASTM D1238;
- 15-30 weight percent of a wax having a Ring and Ball softening temperature between about 135.degree.-160.degree. F. (about 57.degree.-71.degree. C.);
- and
- 40-60 weight percent of a tackifier, and wherein the composition has a Ring and Ball softening temperature less than 190.degree. F. (87.8.degree. C.), wherein the composition is tacky and sufficiently strong and adhesive to bind an ophthalmic lens to a substrate during grinding of the lens.
Dependencies are inferred from the claim text.