| 摘要 |
An improved phenol formaldehyde resin not requiring fillers or extenders and capable of bonding wafers or veneers having a moisture content of 10% or above is disclosed. The adhesive composition is prepared by mixing together a caustic solution of a high molecular weight PF resin, a dispersion of PF resin which is characterized in that it can swell in aqueous caustic medium but not go into solution, and alkylene carbonates or phenol resorcinol formaldehyde resins. Optionally, borax is utilized. The disperse phase is made by converting a solution of PF resin into a fine particle size particulate form by precipitation, spray drying or freeze drying, and partially cross-linking the resin during or subsequent to the formation of the fine particle size dispersion. The PF resin is partially cross-linked by (a) heat, by (b) acid catalysis, or by (c) a reaction with cross-linking chemicals. Also disclosed is a wood product produced from veneers having moisture contents of 10% or above and incised to improve their permeability to gases and liquids.
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