US 4,048,413 AGranted

High-conversion drift-free batch-type addition copolymerization

AssigneeSCM Corporation

InventorJames B. Wilkens

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Abstract

Copolymer substantially free from compositional drift can be produced in a batch-type addition copolymerization process to a high degree of conversion by initiating the reaction in a monomer-containing phase (optionally dispersed in another phase of a reaction mixture) containing the monomers at mole ratios f.sub.i such that the monomers will initially be incorporated into copolymer at the desired mole ratios F.sub.i and sustaining the reaction while simultaneously controlling the addition each monomer to the phase in which the copolymerization reaction is continuing according to the relation Q.sub.i = f.sub.i Q.sub.0 + (F.sub.i - f.sub.i Q.sub.0 /Q.sub..infin.)Z, where Q.sub.i is the running cumulative moles of monomer i added to the phase in which reaction is occurring (including that initially present), Q.sub.0 is the total moles of all monomers initially present in that phase, Q.sub..infin. is the total moles of all monomers ultimately to be added to that phase, and Z is the running cumulative moles of all monomers converted to copolymer. Q.sub.0 /Q.sub..infin. must not substantially exceed the smallest ratio F.sub.i /f.sub.i for any of the monomers and in the preferred mode is made substantially equal to that smallest ratio, thereby eliminating the corresponding monomer from the continuing addition.

Claims15

Dependent claims

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 .infin., 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.sub.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.sub.i of the moles of each of said monomers incorporated to the moles of all said monomers incorporated, the moles Q.sub.0 of all of said monomers initially present in said monomer-containing phase not substantially exceeding that value which would make the ratio Q.sub.O /Q.sub..infin. equal to the smallest of the ratios F.sub.i /f.sub.i for any of said monomers, where Q.infin. 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.sub.O /2.

3 more elements

Dependencies are inferred from the claim text.