Aqueous-based polyurethane compositions and method of preparation
First Claim
Patent Images
1. A method of preparing an aqueous based polyurethane adhesive solution comprising the steps of:
- providing a reaction mixture comprising an isocyanate-terminated urethane prepolymer and an equivalent excess of water, based on the isocyanate content of said prepolymer;
reacting said prepolymer and said water to effect chain extension of said prepolymer;
controlling the rate of said chain extension by adding to said reaction mixture a monofunctional isocyanate group blocking agent and permitting reaction between said agent and isocyanate groups in said prepolymer;
permitting said prepolymer and said water to react until said reaction mixture acquires a desired adhesive capability; and
adding to said reaction mixture additional said monofunctional isocyanate group blocking agent or a second isocyanate group blocking agent in an amount at least substantially equal to the remaining unreacted isocyanate groups in said prepolymer on an equivalent basis.
4 Assignments
0 Petitions
Accused Products
Abstract
Aqueous-based polyurethane elastomer compositions which can be used as adhesives and a method of preparing same are described. The polyurethane compositions are prepared by chain extending an isocyanate-terminated urethane prepolymer with an equivalent excess of water in the presence of a monofunctional isocyanate group blocking agent to provide a reaction mixture having a desired adhesive capability and thereafter adding additional blocking agent to the reaction mixture in an equivalent amount at least substantially equal to the remaining equivalent amount of unreacted isocyanate groups in the prepolymer.
49 Citations
26 Claims
-
1. A method of preparing an aqueous based polyurethane adhesive solution comprising the steps of:
-
providing a reaction mixture comprising an isocyanate-terminated urethane prepolymer and an equivalent excess of water, based on the isocyanate content of said prepolymer; reacting said prepolymer and said water to effect chain extension of said prepolymer; controlling the rate of said chain extension by adding to said reaction mixture a monofunctional isocyanate group blocking agent and permitting reaction between said agent and isocyanate groups in said prepolymer; permitting said prepolymer and said water to react until said reaction mixture acquires a desired adhesive capability; and adding to said reaction mixture additional said monofunctional isocyanate group blocking agent or a second isocyanate group blocking agent in an amount at least substantially equal to the remaining unreacted isocyanate groups in said prepolymer on an equivalent basis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. An aqueous based, cold seal, polyurethane adhesive solution prepared by a method comprising the steps of:
-
providing a reaction mixture comprising an isocyanate-terminated urethane prepolymer and an equivalent excess of water, based on the isocyanate content of said prepolymer; reacting said prepolymer and said water to effect chain extension of said prepolymer; controlling the rate of said chain extension by adding to said reaction mixture a monofunctional isocyanate group blocking agent and permitting reaction between said agent and isocyanate groups in said prepolymer; permitting said prepolymer and said water to react until said reaction mixture acquires a desired adhesive capability; and adding to said reaction mixture additional said monofunctional isocyanate group blocking agent or a second isocyanate group blocking agent in an amount at least substantially equal to the remaining unreacted isocyanate groups in said prepolymer on an equivalent basis. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
-
-
24. A method of cold seal bonding a first substrate to a second substrate comprising the steps of:
-
coating a surface of said first substrate with an aqueous based, cold seal polyurethane adhesive composition prepared by a method comprising the steps of reacting an isocyanate-terminated urethane prepolymer with an equivalent excess of water, based on the isocyanate content of said prepolymer, in the presence of a monofunctional isocyanate group blocking agent;
permitting said prepolymer and said water to react until the reaction mixture acquires a desired adhesive capability; and
adding to said reaction mixture additional said monofunctional isocyanate group blocking agent or a second isocyanate group blocking agent in an amount at least substantially equal to the remaining unreacted isocyanate groups in said prepolymer on an equivalent basis;drying the adhesive coating; and contacting said second substrate with said coating. - View Dependent Claims (25, 26)
-
Specification