Phenolic resin compositions
AssigneeBorden, Inc.
InventorsPeter H. R. B. Lemon, Derek W. Baker, John Ireland
Life of this patent
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Abstract
A phenolic resin composition comprises an ester-curable phenol-aldehyde resin in alkaline aqueous solution wherein the phenol-aldehyde resin is a methylolated phenolic novolak resin. Preferably, during manufacture of the methylolated phenolic novolak resin, unreacted phenol is removed. The composition may be employed, for reaction with an organic ester hardener, as a binder in the production of foundry moulds and cores having high strength. The further incorporation of an aryloxy alcohol in the novolak resin binder additionally improves the final strength of products obtained by a gas curing technique using ester vapor, such as that of methyl formate.
Claims43
A phenolic resin composition comprising:
- (1) ester-curable phenol-aldehyde resin in alkaline aqueous solution;
- and
- (2) an organic ester
- wherein said ester-curable phenol-aldehyde resin is a methylolated phenolic novolak resin.
Method of using the methylated phenolic novolac resin in alkaline aqueous solution as an ester-curable phenolic resin component in a hardenable composition wherein said phenolic resin component is curable by reaction with an organic ester and wherein said phenolic resin is obtained by subjecting phenolic novolak resin from which unreacted phenol has been removed to a methylolation reaction.
A foundry moulding composition comprising a mixture of
- (1) particulate refractory material;
- and
- (2) methylolated phenolic novolak resin in alkaline aqueous solution
- wherein said composition is hardenable upon reaction of said methylolated phenolic novolak resin with a curing agent, wherein said curing agent comprises an organic ester, and wherein said methylolated phenolic resin is obtained by subjecting a phenolic novolak resin from which unreacted phenol has been removed to a methylolation reaction.
A method of making a foundry sand mould or core comprising:
- (1) mixing together sand, methylolated phenolformaldehyde novolak resin in alkaline aqueous solution and liquid ester curing agent for the resin;
- (2) forming the mixture into the shape of the mould or core;
- and
- (3) allowing the mixture to harden,
- wherein said methylolated phenolic resin is obtained by subjecting a phenolic novolak resin from which unreacted phenol has been removed to a methylolation reaction.
A method of making a foundry sand mould or core comprising;
- (1) mixing together sand and a hardenable binder wherein said binder comprises methylolated phenol-formaldehyde novolak resin in alkaline aqueous solution;
- (2) forming the mixture of step (1) into the shape of the mould or core;
- and
- (3) contacting said shape with vapour of methyl formate to cure said resin and thereby cause said shape to harden,
- wherein said methylolated phenolic resin is obtained by subjecting a phenolic novolak resin from which unreacted phenol has been removed to a methylolation reaction.
A phenolic resin composition suitable for curing by gassing with volatile organic ester comprising:
- (1) methylolated phenolic novolak resin in alkaline aqueous solution;
- and
- (2) from 1 to 20% based on the weight of the methylolated novolak resin of an aryloxy alcohol.
A foundry moulding composition comprising a mixture of
- (1) particulate refractory material;
- and
- (2) hardenable binder
- wherein said composition is hardenable upon reaction with a curing agent comprising methyl formate vapour, wherein said hardenable binder comprises a methylolated phenolic novolak resin in alkaline solution and from 1 to 20% based on the weight of the resin of an aryloxy alcohol, and wherein said methylolated phenolic novolak resin is obtained by subjecting a phenolic novolak resin from which unreacted phenol has been removed to a methylolation reaction.
Dependencies are inferred from the claim text.