Patent GB-1334084-A (GB)
Title: Process for producing polyphenylene oxides
IPC: C08F283/08
Filed: 1970-11-26
Abstract: 1334084 Grafted polyphenylene oxides SUMITOMO CHEMICAL CO Ltd 26 Nov 1970 [29 Nov 1969 4 Dec 1969 (2)] 56211/70 Heading C3G A process for producing a modified polyphenylene oxide comprises polymerizing up to 3 parts by weight of a styrene of Formula (I) or of a mixture of such a styrene with an α- substituted styrene of Formula (II) wherein R<SP>1</SP> 1 , R<SP>1</SP> 2 , R<SP>1</SP> 3 , R<SP>1</SP> 4  and R<SP>1</SP> 5  may be the same or different from each other and each is hydrogen, halogen, cyano, nitro, amino, hydroxy, carboxyl, a hydrocarbon group or halogen- or cyano-substituted hydrocarbon group having 12 or less carbon atoms, or a hydrocarbonoxy group or halogen- or hydrocarbonoxy-substituted hydrocarbonoxy group ' having 12 or less carbon atoms, and R<SP>1</SP> 6  is a hydrocarbon group having 12 or less carbon atoms, in an aqueous dispersion containing a dispersion stabilizer and a radical initiator, in the presence of 1 part by weight of a polyphenylene oxide of Formula III wherein R 1 , R 2 , R 3  and R 4  may be the same or different from each other and each is hydrogen, halogen, a hydrocarbon group or halogen- or cyanosubstituted hydrocarbon group having 12 or less carbon atoms, or a hydrocarbonoxy group or halogen- or cyano-substituted hydrocarbonoxy group having 12 or less carbon atoms, and n  represents the degree of polymerization and is an integer greater than 50. In accordance with two preferred embodiments the process is carried out by using 0À4-3 parts by weight of the styrene compound per part of the polyphenylene oxide, or by using 15-69 parts by weight of the styrene compound with 85-31 parts by weight of a mixture comprising 74- 96% by weight of the polyphenylene oxide and 26-4% by weight of a rubbery polymer. In a preferred embodiment of the invention an excess of the styrene compound is fed initially to the system and is later distilled off in the form of an azeotropic mixture with water during the course of the polymerization, to achieve the desired composition for the modified polyphenylene oxide, and then the polymerization is completed (2-stage process). The polymerization is preferably carried out at 40-150‹C. Numerous examples of the styrene compound, the polyphenylene oxide and the rubbery polymer are given. The radical initiators are preferably organic peroxides whilst the dispersion stabilizer may be polyvinyl alcohol, gelatine, agar, starch, glycerine, the sodium salts of polyacrylic and polymethacrylic acids, polyethylene glycol, ethylene glycol, polyacrylamide and a sodium salt of a 1 : 1 copolymer of styrene and maleic anhydride. Fillers such as talc and clay may also be added. Examples refer to the polymerization under varying conditions of poly(2,6- dimethyl-1,4-phenyleneoxide) with:-(a) styrene in a one-stage process (1), (3), (4); (b) a mixture of styrene, p-methyl-α-methylstyrene and m-methyl-α-methylstyrene in a one-stage process (2); (c) styrene and a graft copolymer of styrene polymerized on to polybutadiene in a one-stage process (5), (8) and a two-stage process (9) (12); (d) a mixture of styrene, p-methyl-α- methylstyrene and m-methyl-α-methylstyrene and a graft copolymer of styrene polymerized on to polybutadiene in a one-stage process (6) and a two-stage process (10). Examples (7) and (12) are similar to (5) and (9) but make use of different rubbery polymers. Example (13) is similar to (I) but makes use of poly(2,6-dichloro- 1,4-phenylene oxide), poly(2,6-di(2-chloroethyl)- 1,4-phenyleneoxide), poly(2,6-dimethoxy-1,4- phenyleneoxide), poly(2-allyl-6-methyl-1,4-phenyleneoxide), or poly(2,6-dibromoethoxy-1,4- phenyleneoxide) whilst Example (14) illustrates the use of p-methylstyrene, p-chlorostyrene, pchloromethoxystyrene, p-methoxystyrene, a mixture of a m-bromo-α-methylstyrene and styrene, or a mixture of p-methoxy-α- methylstyrene and p-methylstyrene.