Patent GB-616894-A (GB)
Title: Direct synthesis of alkyl substituted styrene polymers
IPC: C08F12/12
Filed: 1946-09-17
Abstract: Catalysts comprise a stable complex of an aliphatic ether and boron trifluoride saturated with boron trifluoride in the presence of a mercury salt.  Suitable ethers stable to boron trifluoride are dimethyl, methyl-ethyl and dibutyl ethers.  Suitable mercury salts are mercuric oxide, fluoride and sulphate, and mercurous oxide, fluoride and carbonate.  The catalyst may be prepared by saturating an ether with boron trifluoride and heating the resulting solution with a mercury salt at a temperature between 50 DEG  and 80 DEG  C., but preferably at about 60 DEG  C.  The complex may be formed in an inert diluent and small amounts, e.g. 1-10 per cent by weight of the ether-boron trifluoride solution, of water or acids may be present, e.g. trichloracetic, acetic or phosphoric acid.ALSO:Alkyl substituted styrene polymers are prepared by reacting acetylene with an alkylated benzene having at least one nuclear replaceable hydrogen atom, e.g. toluene, dimethyl-, diethyl- and trimethyl-benzenes, in the presence of a catalyst comprising a stable aliphatic etherboron trifluoride saturated with boron trifluoride in the presence of a mercury salt, e.g. mercuric oxide, fluoride or sulphate, or mercurous oxide, fluoride or carbonate.  The reaction may be effected at a temperature of -30 DEG  to +70 DEG  C. or substantially -5 DEG  to +5 DEG C.  An inert gas such as nitrogen may be mixed with the acetylene and the reaction may be effected at any desired pressure, e.g. at an increased pressure. Suitable ethers stable to boron trifluoride are dimethyl, methyl-ethyl, and dibutyl ethers.  The catalyst may be prepared by saturating an ether with boron trifluoride and heating the resulting solution with a mercury salt at a temperature of 50 DEG to 80 DEG  C. but preferably about 60 DEG  C.  In examples a dimethyl styrene polymer is prepared from commercial xylene or m-xylene, and a trimethylstyrene polymer is prepared from mesitylene, in each case using a catalyst prepared from boron trifluoride, ethyl ether and mercuric oxide.ALSO:Alkyl substituted styrene polymers are prepared by reacting acetylene with an alkylated benzene having at least one nuclear replaceable hydrogen atom, e.g. toluene, dimethyl-, diethyl-and trimethyl-benzenes, in the presence of a catalyst comprising a stable aliphatic etherboron trifluoride saturated with boron trifluoride in the presence of a mercury salt, e.g. mercuric oxide, fluoride or sulphate, or mercurous oxide, fluoride or carbonate.  The reaction may be effected at a temperature of - 30 DEG to +70 DEG  C. or substantially - 5 DEG  to +5 DEG  C.  An inert gas such as nitrogen may be mixed with the acetylene and the reaction may be effected at any desired pressure, e.g. at an increased pressure. Suitable ethers stable to boron trifluoride are dimethyl, methyl-ethyl and dibutyl ethers.  The catalyst may be prepared by saturating an ether with boron trifluoride and heating the resulting solution with a mercury salt at a temperature of 50 DEG  to 80 DEG C., but preferably about 60 DEG  C.  In examples, a dimethyl styrene polymer is prepared from commercial xylene or m-xylene, and a trimethylstyrene polymer is prepared from mesitylene, in each case using a catalyst prepared from boron trifluoride, ethyl ether and mercuric oxide.