| abstract |
Chipboard showing a strongly reduced formaldehyde- emission is prepared on the basis of cellulose-containing material with a urea-formaldehyde or urea-melamine -formaldehyde resin as a binder, wherein said binder contains 0.45 to 0.65 mole of formaldehyde per mole-equivalent of amino groups and to which between 2 and 20% by wt., relative to the resin, of a protein soluble or dispersible in the resin solution has been added. The resin preferably contains between25 and 45% by wt. of melamine, relative to the combined amount of urea and melamine. The boards have good strength and weather resistance, and have a very low formaldehyde emission. |