Aminoalkylphosphonic acid ester-based textile fire retardants

Abstract

New aminoalkylphosphonic acid esters of the formula ##STR1## wherein R is H or alkyl of up to 4 carbon atoms, R.sub.1 is H or CH.sub.3, R.sub.2 is H, CH.sub.3 or --C(R.sub.1)(NHR.sub.3)P(O)OR.sub.2, and R.sub.3 is H,--C(R.sub.1)(R.sub.2)P(O)(OR).sub.2 or --CH.sub.2 CH.sub.2 NHC(R.sub.1)(R.sub.2)P(O)(OR).sub.2, are prepared from (RO).sub.2 P(O)H, NH.sub.3 or ethylene diamine and formaldehyde, glyoxal, acetaldehyde or acetone. These new compounds can be reacted with methylol phosphorus compounds of the formula P(CH.sub.2 OH).sub.4 Y or P(CH.sub.2 OH).sub.3 where Y is an equivalent amount of the anion of at least one acid, and optionally additionally with urea. The reacting molar ratio of the hydroxymethyl phosphorus compound to the aminoalkylphosphonic acid ester is up to about 6:1 and preferably between about 0.5:1 and 3:1. Advantageously, the hydroxymethyl phosphorus compound is a tetrakis(hydroxymethyl)phosphonium salt, preferably neutralized with caustic soda, and the aminoalkylphosphonic acid ester is O,O-dimethyl aminomethylphosphonate (DAMP). The condensation product, dissolved in water, is padded onto a fabric, preferably a polyester/cotton blend, which is thereafter dried and cured thermally and/or chemically. The fabrics are fire retardant even after multiple launderings.

Dependencies are inferred from the claim text.