Abstract: Thermosetting water-immiscible phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least one mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate. Methods of control of the exothermic addition of formaldehyde to phenol are described.
Type:
Grant
Filed:
December 22, 1978
Date of Patent:
November 25, 1980
Assignee:
Cor Tech Research Ltd.
Inventors:
Sim Y. Leong, Pitchaiya Chandramouli, Ramesh C. Vasishth
Abstract: Water-immiscible thermosetting phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least 1 mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate, in two stages, in which, in the first stage exothermic addition of formaldehyde to phenol occurs and, in the second stage, methylol phenol is polymerized to form the resin. Methods for control of the rate of polymerization, methods of separation of product resin from aqueous phase, methods of molecular weight distribution control, a semi-continuous operation and an alternative polymerization procedure are described.
Abstract: Water-immiscible thermosetting phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least 1 mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate, in two stages, in which, in the first stage exothermic addition of formaldehyde to phenol occurs and, in the second stage, methylol phenol is polymerized to form the resin. Methods for control of the rate of polymerization, methods of separation of product resin from aqueous phase, methods of molecular weight distribution control, a semi-continuous operation and an alternative polymerization procedure are described.
Abstract: Water-immiscible thermosetting phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least 1 mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate, in two stages, in which, in the first stage exothermic addition of formaldehyde to phenol occurs and, in the second stage, methylol phenol is polymerized to form the resin. Methods for control of the rate of polymerization, methods of separation of product resin from aqueous phase, methods of molecular weight distribution control, a semi-continuous operation and an alternative polymerization procedure are described.
Abstract: Water-immiscible thermosetting phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least 1 mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate, in two stages, in which, in the first stage exothermic addition of formaldehyde to phenol occurs and, in the second stage, methylol phenol is polymerized to form the resin. Methods for control of the rate of polymerization, methods of separation of product resin from aqueous phase, methods of molecular weight distribution control, a semi-continuous operation and an alternative polymerization procedure are described.
Abstract: Rigid shaped articles are formed by providing a novel thermosetting phenol-formaldehyde resin having a characteristic structure and infra-red spectrum as a coating over the surfaces of a plurality of individual elements, forming the coated elements into a shape and thermosetting the resin of the coating.
Type:
Grant
Filed:
June 30, 1977
Date of Patent:
October 24, 1978
Assignee:
Cor Tech Research Ltd.
Inventors:
Ramesh C. Vasishth, Pitchaiya Chandramouli
Abstract: A rapidly curable phenol-formaldehyde resin is provided in the form of an emulsion which has particular utility in panel board production, particularly waferboard production.
Type:
Grant
Filed:
December 27, 1976
Date of Patent:
April 25, 1978
Assignee:
Cor Tech Research Ltd.
Inventors:
Ramesh C. Vasishth, Pitchaiya Chandramouli