Melamine in urea-extended phenol/formaldehyde fiberglass binders
AssigneeJohns Manville International, Inc.
InventorsGerard J. DeMott, Thomas John Taylor, Glenn S. Aspholm
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Abstract
Urea-extended phenol/formaldehyde alkaline resole binders suitable for fiberglass and having a high binding efficiency are disclosed. These binders are prepared by adding a minor quantity of melamine in an amount such that the binder solution contains no solid melamine particulates at room temperature. The resulting binders, when applied to fiberglass and cured, have a binding efficiency close to 100%, and further increase the recovery and physical properties of the binder-containing fiberglass product.
Claims10
A method for manufacturing an aqueous binder solution suitable for applying to fiberglass as a binder, said binder having high binding efficiency, wherein said aqueous binder solution is prepared by the steps of:
- (A) first selecting an aqueous resole having a pH greater than 7, prepared by reacting phenol with excess formaldehyde under alkaline conditions;
- (B) subsequently adding to said aqueous resole (A) urea in an amount from about 20 to about 70 parts by weight based on 100 parts by weight of the phenol/formaldehyde resole solids in component A and reacting to form a urea-extending prereact;
- (C) thereafter dissolving into said prereact from about 1 to about 10 weight percent melamine based on the weight of the solids in the urea-extended phenol/formaldehyde prereact (B);
- wherein said alkaline resole contains sufficient excess formaldehyde to react with said urea and said melamine on a substantially equimolar basis.
A method for manufacturing an aqueous binder solution suitable for applying to fiberglass as a binder, said binder having high binding efficiency, wherein said binder solution comprises:
- preparing a prereact by first mixing
- (A) from 50 to about 80 parts by weight based on solids of a water-soluble resole having a pH greater than 7, prepared by reacting phenol with excess formaldehyde under alkaline conditions, said resole containing or adjusted to contain sufficient unreacted formaldehyde to react with
- (B) from 15 to about 40 parts by weight urea;
- (C) from 1 to 4% by weight, based on the weight of solids A and B, of melamine;
- and subsequently adding
- (D) water in an amount such that the total of solids in said binder is within the range of 10 weight percent to 50 weight percent,
- wherein none of said melamine is present in the solid state in said binder solution.
Dependencies are inferred from the claim text.