GB1258652A - - Google Patents

Abstract

1,258,652. Flame-retardant cellulose material. J. P. STEVENS & CO. Inc. 14 March, 1969 [15 March, 1968], No. 13460/69. Heading C3A. A flame-retardant cellulosic product is prepared by applying an N-(oxymethyl)-3-phosphonopropionamide to the cellulosic material and reacting the amide with the material in the presence of an acidic catalyst (such as HCl, H 2 SO 4 , formic acid, ammonium sulphate, zinc nitrate, zinc tetrafluoroborate, zinc chloride, magnesium chloride, aluminium chloride hexahydrate, ammonium oxalate or ammonium lactate) to form a water-insoluble product and thereafter applying a poly-(oxymethyl) melamine and treating the melamine with hydrogen peroxide to increase the nitrogen content of the material. Preferably, the propionamide has the formula wherein R is C 1-6 alkyl or halogen substituted C 1-6 alkyl; R<SP>1</SP> is H or C 1-6 alkyl; and R<SP>2</SP> is H, C 1-6 alkyl or C 1-6 alkenyl; and the melamine has the formula wherein C 3 N 3 represents a s-triazine ring; each of x, y and z is an integer from 0 to 3 provided the sum of x, y and z is 3 and the compound contains at least two oxymethyl groups; and R<SP>3</SP> is H or C 1-6 alkyl. The propionamide may be N - (hydroxymethyl) - 3 - (dimethylphosphono) propionamide, N - (hydroxymethyl)-3- (diethylphosphono) propionamide, or N - (hydroxymethyl) - 3 - [bis - (2 - chloroethyl) phosphono] propionamide and the melamine may be N<SP>2</SP>,N<SP>4</SP>,N<SP>6</SP> - tris - (hydroxymethyl) melamine. The propionamide may be employed in an amount sufficient to provide from 0À5 to 1À8 weight per cent P, based on cellulose, and the melamine may be employed in an amount sufficient to provide from 1À7 to 10% N based on cellulose, the nitrogen content being at least 9-4P, wherein P is the weight per cent phosphorus based upon cellulose. The material is preferably washed to remove the acid catalyst before treatment with the peroxide, e.g. hydrogen peroxide.