A process for the increase of the strength properties of cement-bound particle boards or the like plates

摘要

Cement bonded chipboard is produced by (a) mixing water, cement and wood chips, (b) adding a dispersion of 2.5-15% copolymer, based on wt. of wood, to the mixt. (c) forming the mixt. into chipboard, and (d) pressing and drying. Gives high quality chipboard with a high flex strength, tensile strength, scratch resistance and weather resistance without requiring expensive or time consuming operations. The copolymer pref. contains 5-50 wt.% vinyl chloride units, 25-40 wt.% units of a vinyl ester of a 1-3C carboxylic acid, and 25-50 wt.% units of a cpd. of formula R1CH=CR3COOR2 (where R' is H, alkyl or COOR2; R2 is 4-8C alkyl; of R3 is H or CH3), or 5-40 wt.% vinyl chloride; 40-80 wt.% vinyl ester, at 5-25 wt.% ethylene.