High-conversion drift-free batch-type addition copolymerization

Claim 1

A non-azeotropic batch-type addition copolymerization process for producing copolymer of substantially uniform composition from a plurality of mutually copolymerizable ethylenically unsaturated monomers, each of said monomers designated herein by a different value of the index i other than 0 or ∞, said process comprising a. forming a reaction mixture comprising a monomer-containing phase in which said monomers are present in substantially those mole ratios f i of the moles of each of said monomers to the moles of all of said monomers required to initially produce copolymer in which said monomers are incorporated in substantially the desired mole ratios F i of the moles of each of said monomers incorporated to the moles of all said monomers incorporated, the moles Q 0 of all of said monomers initially present in said monomer-containing phase not substantially exceeding that value which would make the ratio Q O /Q.sub.∞ equal to the smallest of the ratios F i /f i for any of said monomers, where Q∞ is the total moles of all of said monomers to be copolymerized; b. initiating an addition copolymerization reaction of said monomers in said monomer-containing phase; and c. sustaining said reaction in said monomer-containing phase under substantially constant conditions, while simultaneously introducing into said reaction mixture a monomer feedstream which controls the cumulative molar addition of each of said monomers to said monomer-containing phase to have substantially the values given by Q.sub.i = f.sub.i Q.sub.O + (F.sub.i - f.sub.i Q.sub.O /Q.sub.28 )Z when the cumulative moles of all of said monomers converted in said monomer-containing phase to said copolymer is Z, at least until the total unreacted moles of all of said monomers present in said monomer-containing phase is reduced to about Q O /2.