Patent ID: 8535578

Claim:
A flame-retardant wood-base material selected from the group consisting of debarked trunks, planks, beams, strips, sheets, layers, veneers, posts, poles, plywood, laminated wood, laminates, chipboards and wood fiberboards, containing as flameproofing compositions, salts of halogen-free organic phosphonic acids of the formula (I) wherein R represents a divalent, straight-chain or branched or cyclic C 1 - to C 10 -hydrocarbon radical optionally containing up to three nitrogen atoms and optionally substituted by up to four hydroxyl groups, R 1 , R 2 and R 3 , independently of one another, represent H, or NR 4 R 5 R 6 R 7 , at least one of the radicals R 1 , R 2 and R 3 not being H, X represents C, S═O, or P—O—R 1 and R 4 , R 5 , R 6 and R 7 , independently of one another, represent H, straight-chain or branched C 1 - to C 18 -alkyl, C 2 - to C 4 -hydroxyalkyl or benzyl and/or at least one NH 4 salt of 2-phosphonobutane-1,2,4-tricarboxylic acid, NH 4 salt of nitrilotrismethylenetris(phosphonic acid), and NH 4 salt of diethylenetriamine-pentakis(methylenephosphonic acid).