| 摘要 |
Polymers of vinyl esters are manufactured by polymerizing the monomers in the presence of a catalyst comprising a mixture of a trialkyl aluminium and an organic peroxide or hydroperoxide. Specified vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate and vinyl stearate. The aluminium trialkyl may contain 1 to 12 carbon atoms in each alkyl group, e.g. aluminium triethyl or triisobutyl. The peroxide may be an alkyl peroxide, ketone peroxide, aldehyde peroxide, acyl peroxide or alkyl hydroperoxide, e.g. diacetyl peroxide, dibenzoyl peroxide, dilauroyl peroxide and t-butyl hydroperoxide. The polymerization may be effected batchwise or continuously in the presence of solvents and may be accelerated by small amounts of oxygen. The monomer and/or catalyst components may be added continuously or incrementally. Examples describe the polymerization of vinyl acetate in the presence of (1) diacetyl peroxide and triethyl aluminium, (2) dibenzoyl peroxide and triisobutyl aluminium and (4) t-butyl hydroperoxide and triethyl aluminium; and vinyl butyrate in the presence of (3) diacetyl peroxide and triethyl aluminium. The products may be converted to polyvinyl alcohol or polyvinyl acetals. Specification 367,102 is referred to.
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