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US 4,525,492 AGranted
Modified phenolic foams
AssigneeFiberglas Canada Inc.
InventorsMary H. Rastall, Norman H. Ng, Edwin J. MacPherson
Life of this patent
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Abstract
Phenolic foams and a method of producing phenolic foam material from phenol-formaldehyde resins having a phenol to formaldehyde mole ratio of between about 1:3 and 1:4.5 are described. These materials are useful for insulation and other uses, particularly in the building trades. They are dimensionally and thermally stable, fire resistant and low in cost.
Claims20
A method of making a phenolic foam material consisting essentially of the steps of:
- (1) preparing a base-catalyzed phenol-formaldehyde resole having a mole ratio of phenol to formaldehyde of between 1:3 and 1:4.5 and containing substantially no free phenol;
- and
- (2) reacting 100 parts by weight, calculated as resin solids, of an aqueous solution of said resole of step (1) with:
- (a) 10 to 55 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide to reduce the amount of free formaldehyde contained in said resole;
- (b) 0.1 to 10 parts by weight of a surfactant;
- (c) 3 to 25 parts by weight of a blowing agent;
- and
- (d) a catalyst consisting of an acidic material to reduce the pH of the mixture to below 4, or a basic material to increase the pH of the mixture to above 8.
5 more elements
A method of making a phenolic foam material consisting essentially of the sequential steps of:
- (1) preparing a base-catalyzed phenol-formaldehyde resole having a mole ratio of phenol to formaldehyde of between 1:3 and 1:4.5 and containing substantially no free phenol;
- (2) reacting 100 parts by weight, calculated as resin solids, of an aqueous solution of said resole with 20 to 55 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide to reduce the amount of free formaldehyde contained in said resole;
- (3) adding to the product of step (2):
- (a) 0.1 to 10 parts by weight of a surfactant;
- and
- (b) 3 to 25 parts by weight of a blowing agent;
- (4) initiating foam formation by adding to the mixture of step (3) an acidic catalyst to reduce the pH of the mixture to below 4;
- and
- (5) curing the mixture of step (4).
6 more elements
A foamable phenolic composition consisting essentially of:
- (1) 100 parts weight, calculated as resins solids, of an aqueous solution of a base-catalyzed phenol-formaldehyde resole having a mole ratio of phenols to formaldehyde of between 1:3 and 1:4.5 and containing substantially no free phenol;
- (2) 10 to 55 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide;
- (3) 0.1 to 10 parts by weight of a surfactant;
- (4) 3 to 25 parts by weight of a blowing agent;
- and
- (5) a catalyst consisting of an acidic material to reduce the pH of the reaction mixture to below 4, or a basic material to increase the pH of the reaction mixture to above 8.
3 more elements
A foamable phenolic composition consisting essentially of:
- (1) 100 parts by weight, calculated as resin solids, of an aqueous solution of a base-catalyzed phenol-formaldehyde resole having a mole ratio phenol to formaldehyde between 1:3.5 and 1:4 and containing substantially no free phenol;
- (2) 25 to 45 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide;
- (3) 0.5 to 6 parts by weight of a surfactant;
- (4) 3 to 25 parts by weight of blowing agent;
- and
- (5) an acidic catalyst to reduce the pH of the reaction mixture to below 4.
3 more elements
A phenolic foam material consisting essentially of the cured reaction product of:
- (1) 100 parts by weight, calculated as resin solids, of an aqueous solution of a base-catalyzed phenol-formaldehyde resole having a mole ratio of phenol to formaldehyde of between 1:3 and 1:4.5 and containing substantially no free phenol;
- (2) 10 to 55 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide;
- (3) 0.1 to 10 parts by weight of a surfactant;
- (4) 3 to 25 parts of weight of a blowing agent;
- and
- (5) a catalyst consisting of an acidic material to reduce the pH of the reaction mixture to below 4 or a basic material to increase the pH of the reaction mixture to above 8.
3 more elements
A phenolic foam material consisting essentially of the cured reaction product of:
- (1) 100 parts by weight, calculated as resin solids, of an aqueous solution of a base-catalyzed penol-formaldehyde resole having a mole ratio of phenol to formaldehyde of between 1:3.5 and 1:4 and containing substantially no free phenol;
- (2) 25 to 45 parts by weight of a co-reactant selected from the group consisting of urea, melamine and dicyandiamide;
- (3) 0.5 to 6 parts by weight of a surfactant;
- (4) 3 to 25 parts by weight of a blowing agent;
- and
- (5) an acidic catalyst to reduce the pH of the reaction mixture to below 4.
3 more elements
Dependencies are inferred from the claim text.