Process for producing styrene-based polymers and catalysts for use therein

Claim 1

A process for producing a styrene-based polymer having a mainly syndiotactic configuration which comprises polymerizing at least one monomer selected from styrene and a styrene derivative at a polymerizing temperature of -10° C. to 100° C. in the presence of a catalyst containing (A) a titanium compound, (B) alkylaluminoxane having alkyl groups with 1 to 8 carbon atoms, and (C) an organic polyhydroxy compound, wherein (A) said titanium compound is at least one compound represented by the formula: TiR.sup.1.sub.a R.sup.2.sub.b R.sup.3.sub.c R.sup.4.sub.4-(a+b+c)(I) or TiR.sup.1.sub.d R.sup.2.sub.e R.sup.3.sub.3-(d+e) (II) where R 1 , R 2 , R 3 and R 4 are independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a halogen atom, a, b and c are independently an integer of 0 to 4, and d and e are independently an integer of 0 to 3; and (C) the organic polyhydroxy compound is at least one compound selected from the group consisting of ethylene glycol, propylene glycol, 1,4-butanediol, 1,2-pentanediol, hexanediol, pinacol, glycerine, diethylene glycol, triethylene glycol, dipropylene glycol, 1,4-cyclohexane diol, 1,3-cyclohexane diol, sorbitol, mannitol, hydroquinone, catechol and pyrogallol, and said catalyst obtained by individually mixing components (A), (B), and (C), such that the alkylaluminoxane and organic polyhydroxy compound are contacted prior to introducing the titanium compound.