Catalytic composition and method for curing urea-formaldehyde resin
AssigneeBorden Chemical, Inc.
InventorsWilliam K. Motter, Nick K. Daisy, William D. Detlefsen
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Abstract
Disclosed is a binder composition for binding substrates such as wood furnish for particleboard manufacture. The binder comprises a mixture of a first aqueous solution, comprising a buffering salt catalyst and preferably an acid, with a second aqueous solution comprising urea and formaldehyde. Methods of using the buffering salts as catalyst for curing urea-formaldehyde resins are also disclosed.
Claims43
A binder composition comprising a mixture of:
- a first aqueous solution comprising at least one buffering salt catalyst, the first aqueous solution having a pH of about 3.5 to about 8.5;
- and
- a second aqueous solution comprising urea and formaldehyde resin having a urea:formaldehyde molar ratio ranging from about 0.7 to about 1.67:1, wherein the second aqueous solution comprises about 10 to about 40 weight percent of free urea;
- wherein the amount of the at least one buffering salt in the mixture equals about 0.05 to about 15 percent of the weight of the second aqueous solution, and about 0 to about 2 weight percent of the second aqueous solution is free formaldehyde.
A method of achieving rapid cure of urea-formaldehyde resin comprising the steps of:
- mixing a first aqueous solution comprising at least one buffering salt, the first aqueous solution having a pH of about 3.5 to about 8.5, with a second aqueous solution comprising urea and formaldehyde resin in a molar ratio of about 0.33 to about 1.67:1, wherein the second aqueous solution comprising about 10 to about 40 weight percent of free urea, to form a binder;
- wherein the amount of the at least one buffering salt in the first aqueous solution equals about 0.5 to about 15 weight percent of the weight of the second aqueous solution, and about 0 to about 2 weight percent of the second aqueous solution is free formaldehyde.
A binder composition comprising a mixture of:
- a first aqueous solution comprising at least one buffering salt catalyst, the first aqueous solution having a pH of about 2 to about 8.5;
- and
- a second aqueous solution of urea and formaldehyde resin having a urea:formaldehyde molar ratio ranging from about 0.33 to about 1.67:1;
- wherein the amount of the at least one buffering salt in the mixture equals about 0.05 to about 15 percent of the weight of the second aqueous solution, and about 0 to about 2 weight percent of the second aqueous solution is free formaldehyde, wherein the buffering salt catalyst comprises a member of the group consisting of monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, sodium acetate, sodium citrate, borates, phthalates, bicarbonates and mixtures thereof.
A method of achieving rapid cure of urea-formaldehyde resin comprising the steps of:
- mixing a first aqueous solution comprising at least one buffering salt, the first aqueous solution having a pH of about 2 to about 8.5, with a second aqueous solution comprising urea and formaldehyde resin in a molar ratio of about 0.33 to about 1.67:1, to form a binder;
- wherein the amount of the at least one buffering salt in the first aqueous solution equals about 0.05 to about 15 weight percent of the weight of the second aqueous solution, and about 0 to about 2 weight percent of the second aqueous solution is free formaldehyde, wherein the buffering salt comprises a member of the group consisting of monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, sodium acetate, sodium citrates, borates, phthalates, bicarbonates and mixtures thereof.
Dependencies are inferred from the claim text.