초록 ▼

Oriented strand board is post-fabrication treated with a polymeric coating which includes isocyanate constituents to produce a construction material which is smooth, has high gloss, and which is resistant to water, vapor, and chemical penetration. The isocyanate constituents are most preferably MDI

Oriented strand board is post-fabrication treated with a polymeric coating which includes isocyanate constituents to produce a construction material which is smooth, has high gloss, and which is resistant to water, vapor, and chemical penetration. The isocyanate constituents are most preferably MDI or PMDI, and may be present in a coating composition alone or in combination with other binder materials such as PEEG or other polyols. Prior to application of the coating composition, the surface of the oriented strand board is pretreated using heat and pressure to compress and densify wood at the surface, and to smooth out minor surface irregularities. The coating composition is then applied to the wood surface, and is cured to form a polymeric coating which bonds to the wood material. The polymeric coating is preferably a polyurethane and functions to prevent water, vapor, and chemical penetration into the oriented strand board, thereby permitting its use as a construction material in a wide variety of applications it heretofore has not achieved commercial acceptance. In addition, the polymeric coating provides the oriented strand board with a smooth surface.

대표청구항 ▼

[ We claim:] [1.] A method for improving the surface properties of a wood board, comprising the steps of:providing a wood board having a surface and an inner region, where said surface and said inner region are both comprised of wood material;pre-treating the wood board to produce a transitional reg

[ We claim:] [1.] A method for improving the surface properties of a wood board, comprising the steps of:providing a wood board having a surface and an inner region, where said surface and said inner region are both comprised of wood material;pre-treating the wood board to produce a transitional region on the surface by heating and pressing the wood board effective to (i) increase the density of wood material at the surface relative to wood material at the inner region, (ii) initiate carmelization of short-chain carbohydrates in wood cell walls of said wood material at said surface, and (iii) burn off any extraneous fibers on said surface;cooling the pre-treated wood board;applying, after said pre-treating step, a polymer forming composition including isocyanate constituents to said transitional region on said surface of the pretreated wood board; andcuring said composition to form a polymeric coating on said wood board bonded to wood material in said wood board, to thereby form a construction material having increased moisture resistance and a smooth, hard surface.