Polymer, process and composition

Abstract

There are described q oligomer-polymer composition [optionally substantially free of styrene (<1.5 wt-% of copolymer)] comprising oligomer composition O having a weight average molecular weight of from 1000 to 150,000 g/mol (measured by GPC) and polymer composition P having a weight average molecular weight of at least 80,000 g/mol (measured by GPC) the oligomer composition O and the polymer composition P each independently comprising a copolymer composition comprising: (a) at least 8.5 wt-% preferably >=20 wt-% of a higher itaconate diester (preferably dibutyl itaconate—DBI); (b) less than 23 wt-% acid monomer but also sufficient to have an acid value less than 150 mg KOH/g of polymer, (c) optionally with less than 50 wt-% of other itaconate monomers, and (d) optionally less than 77 wt-% of other monomers not (a) to (c). The DBI may be biorenewable. One embodiment is an aqueous dispersion of vinyl sequential polymer of two phases: A) 40 to 90 wt-% of a vinyl polymer A with Tg from −50 to 30° C.; and B) 10 to 60 wt-% of a vinyl polymer B with Tg from 50 to 130° C.; where DBI is used to prepare A and/or B and polymer A has from 0.1 to 10 wt-% of at least one acid-functional olefinically unsaturated monomer. Another embodiment is an aqueous polymer coating composition of a vinyl oligomer C of Mw from 1,000 to 150,000 g/mol and an acid value>5 mgKOH/g; and a vinyl polymer D of Mw>=80,000 g/mol and an acid value<10 mgKOH/g where D is obtained from DBI and the amount of monomers used to form C and D fall into the respective weight ratios 5 to 70 for polymer C and 95 to 30 for polymer D. A further embodiment is an aqueous suspension polymerization process for preparing vinyl polymer beads from olefinically unsaturated monomers and a free-radical initiator, where at least 10 wt-% of the monomer is DBI.