Silylated polymer derived from butadiene and solvent-resistant pressure sensitive adhesive composition containing same
AssigneeMomentive Performance Materials Inc.
InventorsRobert L. Frye, Richard P. Eckberg, Roy M. Griswold
Life of this patent
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Abstract
A silylated polymer contains repeating units derived from butadiene. The polymer when partially silylated is especially useful for pressure sensitive adhesives where it imparts superior solvent resistance performance thereto.
Claims24
A silylated polymer obtained by the process which comprises:
- a) reacting hydroxyl-terminated polybutadiene and, optionally, chain extender and/or other polyol, with polyisocyanate in the presence of a monofunctional fluorine-containing organic compound possessing an isocyanate reactive functionality to provide isocyanate-terminated polyurethane prepolymer;
- and,
- b) reacting the isocyanate-terminated polyurethane prepolymer with silane possessing hydrolyzable functionality and isocyanate-reactive functionality to provide silylated polyurethane prepolymer wherein less than all of the isocyanate groups of the isocyanate-terminated polyurethane prepolymer are silylated.
A silylated polymer obtained by the process which comprises:
- a) blending at least one hydroxyl-terminated polybutadiene diol possessing terminal hydroxyl groups bonded to carbon atoms adjacent to double bonded carbon atoms and a number average molecular weight of from 500 to 10,000 grams per mole, at least one hydroxyl-containing polybutadiene polyol possessing an average of from 2.4 to about 2.8 hydroxyl groups per molecule, and optionally, chain extender and/or other polyol,
- b) reacting the mixture of step (a) with diisocyanate to provide hydroxyl-terminated polyurethane prepolymer possessing a molar ratio of NCO to OH of from about 0.3 to about 0.95;
- and,
- c) reacting the hydroxyl-terminated polyurethane prepolymer of step (b) with isocyanatosilane possessing hydrolyzable functionality to provide silylated polyurethane possessing a level of silation of not more than 95 percent.
A curable pressure sensitive adhesive composition comprising a pressure sensitive adhesive amount of at least one partially silylated polyurethane obtained by the process which comprises:
- a) reacting hydroxyl-terminated polybutadiene and, optionally, chain extender and/or other polyol, with polyisocyanate to provide isocyanate-terminated polyurethane prepolymer;
- and,
- b) reacting the isocyanate-terminated polyurethane prepolymer with silane possessing hydrolyzable functionality and isocyanate-reactive functionality to provide silylated polyurethane prepolymer wherein less than all of the isocyanate groups of the isocyanate-terminated polyurethane prepolymer are silylated;
- and,
- c) carrying out step (b) in the additional presence of monofunctional isocyanate-capping reactant to cap non-silylated isocyanate groups in the silylated polyurethane, wherein the curable pressure sensitive adhesive composition further comprises a tackifying amount of MQ tackifier resin and a curing catalyst therefor.
A curable pressure sensitive adhesive composition comprising a pressure sensitive adhesive amount of at least one partially silylated polyurethane obtained by the process which comprises:
- a) blending at least one hydroxyl-terminated polybutadiene diol possessing terminal hydroxyl groups bonded to carbon atoms adjacent to double bonded carbon atoms and a number average molecular weight of from 500 to 10,000 grams per mole, at least one hydroxyl-containing polybutadiene polyol possessing an average of from 2.4 to about 2.8 hydroxyl groups per molecule, and optionally, chain extender and/or other polyol,
- b) reacting the mixture of step (a) with diisocyanate to provide hydroxyl-terminated polyurethane prepolymer possessing a molar ratio of NCO to OH of from about 0.3 to about 0.95;
- and,
- c) reacting the hydroxyl-terminated polyurethane prepolymer of step (b) with isocyanatosilane possessing hydrolyzable functionality to provide silylated polyurethane possessing a level of silation of not more than 95 percent,
- and wherein said curable pressure sensitive adhesive composition further comprises a tackifying amount of MQ tackifier resin and a curing catalyst therefor.
Dependencies are inferred from the claim text.