Flame retardation of polymeric compositions

Abstract

Compositions are disclosed for the flame retardation of polymeric compositions including fillers such as glass fibers. The compositions contain a flame retarding effective additive of at least one polyphosphate, a sulfur containing compound, catalyst and a nitrogen containing compound such as melamine.

What is claimed  
     
         1 . A flame retardant composition comprising at least one thermoplastic polymer, having incorporated therein an amount of filler or reinforcing agent (e) not exceeding about 40% by weight of the composition and a flame retardant effective amount of at least two additives selected from the group consisting of 
 (b) ammonium polyphosphate, melamine polyphosphate and their mixtures, in the range of 10-40% of the total weight of the composition, at least a portion of (b) being ammonium polyphosphate,    (a) a sulfur containing material or mixtures of at least two sulfur containing materials with a sulfur content in the range of about 0.1-1.0% of the total weight of the composition said sulfur containing materials being members of the group consisting of elemental sulfur, sulfamic acid, imidobisulfonic acid, mono diammonium as well as monovalent, divalent and multivalent metal salts of sulfamic acid and imidobisfulfonic acid, sulfamide, sulfimide, and their inorganic substituents and mixtures, sulfurous acid and its monovalent, divalent and multivalent metal salts as well as its organic derivatives and sulfides of monovalent, divalent and multivalent metals,    (c) a catalyst selected from the group of oxides and salts of monovalent, divalent and multivalent metals in amounts of 0.5-5% of the total weight of the composition and    (d) a nitrogen-containing compound selected from the group consisting of melamine, its condensation products melem, melam and melone, guanidine, urea and their methylol derivatives and alkylene diamine in amounts of 0.5-6% of the total weight of the composition,    further provided that the following ratio's of the percentage weights of the ingredients in the composition are adhered to:    polymer/(b)=1.0-6.0;    polymer/(a)=600-40;    (b)/(a)=400-10;    (b)/(c)=80-2.0;    (b)/(d)=80-1.6    
     
     
         2 . A composition according to  claim 1  wherein the polymer is composed of a member or a blend of members selected from the group consisting of polyamides, polybutylene terephthalate, polyethylene terephthalate, polypropylene, polyethylene, polystyrenes, polyurethanes, polyacrylics, polycarbonates, polyarylates, polysulfones, polyetherketones, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, epoxy resins, and blends or mixtures thereof.  
     
     
         3 . A composition according to  claim 1  comprising by weight at least 20% of polymer and the additives (a)-(d) in the following weight percentages calculated on the weight of the composition 
 (a) about 0.1-1.0% of elemental sulfur contained in the sulfur compound or mixtures  
 (b) about 10-40%  
 (c) about 0.5-5.0%  
 (d) about 0.5-6.0%  
 
     
     
         4 . A composition according to  claim 1  wherein (a) is elemental sulfur, the polymer is a polyamide selected from the group consisting of polyamide 6, polyamide 66, blends of PA6 and 66, PA-11, PA-12, PA-4.4, PA-6.3, PA-6.4, PA-6.10, PA-6.12, PA-4.6, polybutylene terephthalate, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyacrylonitril and polycarbonate.  
     
     
         5 . A flame retardant composition comprising a thermoplastic polymer in the form of a polyamide having incorporated therein glass fibers, the amount of glass fibers not exceeding 40% by weight, and a flame retardant effective amount of at least two additives selected from the group consisting of 
 (b) ammonium polyphosphate, melamine polyphosphate and their mixtures, in the range of 10-40% of the total weight of the composition at least a portion of (b) being ammonium polyphosphate,    (a) a sulfur containing material or mixtures of at least two of such materials containing sulfur in the range of 0.1-1.0% of the total weight of the composition, said materials being selected from the group consisting of sulfamic acid, imidobisulfonic acid, mono and diammonium as well as monovalent, divalent and multivalent metal salts of sulfamic acid and imidobisfulfonic acid, sulfamide, sulfimide, and their inorganic substituents and mixtures, sulfurous acid and its monovalent, divalent and multivalent metal salts as well as its organic derivatives, and sulfides of monovalent, divalent and multivalent metals,    (c) a catalyst being oxides and salts of monovalent, divalent and multivalent metals in amounts of 0.5-5% of the total weight of the composition, and    (d) a nitrogen-containing compound being of melamine, its condensation products melem, melam and melone, guanidine, urea and their methylol derivatives and alkylene diamine in amounts of 0.5-6% of the total weight of the composition,    wherein the following ratios of the percentage weights of the ingredients in the composition apply:    polyamide/(b)=1.0-6.0;    polyamide/(a)=600-40;    (b)/(a)=400-10;    (b)/(c)=80-2.0; and    (b)/(d)=80-1.6