Flame retarder, flame retardant resin composition and method of producing the flame retarder

A flame retardant resin composition containing a flame retarder to confer flame retardant properties on the resin composition, wherein

• said flame retarder includes an acrylonitrile-styrene based polymer containing at least acrylonitrile and styrene;
• wherein
• said acrylonitrile-styrene based polymer is sulfonated with a sulfonating agent containing less than 3 wt % of moisture, whereby sulfonic acid groups and/or sulfonate groups have been introduced into said acrylonitrile-styrene based polymer.

A method for producing a flame retarder to be contained in a resin composition to confer flame retardant properties on said resin composition, comprising

• sulfonating an acrylonitrile-styrene based polymer, containing at least acrylonitrile and styrene, with a sulfonating agent containing less than 3 wt % of moisture, for introducing sulfonic acid groups and/or sulfonate groups into said acrylonitrile-styrene based polymer.

A method for producing a flame retarder to be contained in a resin composition to confer flame retardant properties on said resin composition, comprising:

• reacting a powdered acrylonitrile-styrene based polymer, containing at least acrylonitrile and styrene, with an SO3 gas for performing sulfonating processing for introducing sulfonic acid groups and/or sulfonate groups into said acrylonitrile-styrene based polymer.

A flame retarder to be contained in a resin composition to confer flame retardant properties on said resin composition, wherein

• sulfonic acid groups and/or sulfonate groups are introduced into an aromatic polymer containing monomer units having aromatic skeletons in an amount ranging between 1 mol % and 100 mol %, said polymer having a weight average molecular weight ranging between 25000 and 10000000, and wherein
• the sulfur content of said sulfonic acid groups and/or sulfonate groups ranges between 0.001 wt % and 20 wt %.

A flame retardant resin composition to which flame retardant properties have been imparted by a flame retarder contained therein, wherein

• sulfonic acid groups and/or sulfonate groups are introduced into the resin composition containing monomer units having aromatic skeletons in an amount ranging between 1 mol % and 100 mol %, said polymer having a weight average molecular weight ranging between 25000 and 10000000, and wherein
• the sulfur content of said sulfonic acid groups and/or sulfonate groups ranges between 0.001 wt % and 20 wt %.

A flame retarder to be contained in a resin composition to confer flame retardant properties on said resin composition, wherein

• the flame retarder includes an aromatic polymer containing monomer units having aromatic skeletons ranging between 1 mol % and 100 mol %, and wherein sulfonic acid groups and/or sulfonate groups are introduced in an amount ranging between 0.01 mol % and 14.9 mol % into the aromatic polymer.

A flame retardant resin composition to which flame retardant properties have been imparted by a flame retarder contained therein, wherein the flame retarder includes an aromatic polymer containing monomer units having aromatic skeletons ranging between 1 mol % and 100 mol %, and wherein sulfonic acid groups and/or sulfonate groups have been introduced in an amount ranging between 0.01 mol % and 14.9 mol % into the aromatic polymer.