Patent ID: 6406749
Filing Date: 2002-06-18
Classification: B27K,C08H,C08K,C08L

Abstract:
A process for chemically modifying wood, comprising(a) placing the wood in a container under vacuum; (b) (i) introducing ammonia gas into the container to impregnate the wood; (ii) releasing the vacuum to remove residual ammonia and removing the residual ammonia from the container; and (iii) subjecting the ammonia gas impregnated wood to a vacuum; (c) impregnating the wood from step (b) with an impregnating composition comprising: (i) dicarboxylic anhydride or tricarboxylic anhydride; (ii) partially or fully hydrolyzed polyvinyl alcohol; and (iii) water; â€ƒwhile applying pressure thereto; (d) removing residual impregnating composition; (e) removing water from the impregnated wood; and, optionally, (f) heating the wood to cause chemical modification of the wood to go to completion.