Phenol formaldehyde resin foams

Claim 3

A method according to claim 1 which comprises: (A) preparing a phenol-formaldehyde resin component by first mixing a resole phenol formaldehyde resin, having a water content of up to 20% and a pH of between 4.0 and 6.0 and which resin was prepared under acid conditions, with a surfactant, a nitrogenous modifier chosen from an amine, or a polymeric amine, or a natural vegetable oil containing amine or amino nitrogen, and a blowing agent chosen from a hydrocarbon or a chloro fluorohydrocarbon; the surfactant, modifier, and blowing agent being added sequentially and in the order given, to the resin; the completed mix then being aged before use; (B) preparing a catalyst by mixing together sulphuric acid, or an organic sulphonic acid together with one or more acids chosen from boric acid, or phosphoric acid, and a polyhydroxy compound chosen from ethylene glycol, propylene glycol and glycerin, in a weight ratio of acid catalyst to polyhydroxy compound of at least 1:1, excluding any boric acid and/or phosphoric acid additions; and (C) optionally after a period of storage, mixing together the components prepared in (A) and (B) in the desired ratio to provide a phenol-formaldehyde resin foam.

Claim 17

A foamable composition comprising in admixture a first component and a second component, said first component comprising a phenol-formaldehyde resin, a blowing agent which is an inert, low boiling liquid, an effective amount of a nitrogenous modifier capable of permitting dispersion of the blowing agent in the resin, and a surfactant, and said second component comprising an acid catalyst dispersed in a liquid polyhydroxy compound, in a weight ratio of acid catalyst to polyhydroxy compound of at least 1:1.

Claim 18

A foamable composition comprising in admixture a first component and a second component, said first component comprising a phenol-formaldehyde resin, a blowing agent which is an inert, low boiling liquid, an effective amount of a nitrogenous modifier capable of permitting dispersion of the blowing agent in the resin, and a surfactant, and said second component comprising an acid catalyst dispersed in a liquid polyhydroxy compound, in a weight ratio of acid catalyst to polyhydroxy compound of at least 1:1.

Claim 19

A foamable composition according to claim 16 comprising in admixture a first component and a second component, said first component comprising: (a) a resole phenol-formaldehyde resin with a water content of up to 20%, which has been prepared under acid conditions, and has a pH of between 4.0 and 6.0; (b) an inert blowing agent chosen from a hydrocarbon or a chlorofluorohydrocarbon; (c) a surfactant; (d) a nitrogeneous modifier chosen from an amine, or a polymeric amine, or a natural vegetable oil containing amine or amino nitrogen; and said second component comprising: (i) an acid catalyst system containing sulphuric acid, or an organic sulphonic acid, together with phosphoric acid, (ii) said acid (i) being dispersed in a polyhydroxy compound chosen from ethylene glycol, propylene glycol, and glycerine, in a weight ratio of acid catalyst to polyhydroxy compound of at least 1:1, excluding any addition of phosphoric acid.

Claim 20

A foamable composition according to claims 16 or 17 wherein the phenol-formaldehyde resin has a pH of from 4.5 to 6.0.

Claim 21

A foamable composition according to claims 16 or 17 wherein the blowing agent is dichlorodifluoromethane.

Claim 22

A foamable composition 16 or 17 wherein the surfactant is a silicone-based material.

Claim 23

A foamable composition 16 or 17 wherein the surfactant is a silicone-based material.

Claim 24

A foamable composition 16 or 17 wherein the second component includes an organic acid chosen from methane sulphonic acid, benzene sulphonic acid, and para-toluene sulphonic acid.

Claim 25

A foamable composition 16 or 17 wherein the second component includes an organic acid chosen from methane sulphonic acid, benzene sulphonic acid, and para-toluene sulphonic acid.

Claim 26

A foamable composition according to claims 16 or 17 wherein the nitrogenous modifier is chosen from at least one of diethanolamine; triethanol amine, diethanoltriamine; triethanoltetramine; piperazine; hexamethylene tetramine, amino group containing urea-formaldehyde polymers based on urea, melamine, and guanidine.

Claim 27

A foamable composition according to claims 16 or 17 wherein the acid catalyst contains 1 part by weight sulphuric acid or organic sulphonic acid, together with zero to 1 part by weight phosphoric acid, and zero to one part by weight boric acid, provided that the weight ratio of other acids to sulphuric acid or organic sulphonic acid does not exceed 1:1.

Claim 28

A foamable composition according to claims 16 or 17 wherein the first component contains by weight: Phenol-formaldehyde resin: 100 parts Surfactant: 0.1 to 4.0 parts Nitrogenous modifier: 1 to 20 parts, and Blowing agent: 1 to 20 parts.

Claim 29

A foamable composition according to claims 16 or 17 wherein the second component comprises 1 part sulphuric acid, 1 part 85% phosphoric acid, and at least 0.5 part propylene glycol, in each case by weight.

Claim 30

A foamable composition according to claims 16 or 17 wherein the phenolformaldehyde resin used has been prepared from substantially pure phenol.

Claim 31

A foamable composition according to claims 16 or 17 wherein the phenolformaldehyde resin has been prepared from technical grade phenol.

Claim 32

A foamable composition according to claims 16 or 17 wherein the phenolformaldehyde resin has been prepared from a technical phenol having a boiling range of 180° to 200° C. and containing not more than 15% by weight of orthocresol plus xylenols.

Claim 33

A foamable composition according to claims 16 or 17 wherein the first component additionally contains a polyhydroxy compound which may be different to that in the second component.