Polymeric beads, process and composition

Abstract

There are described a dispersion of polymeric beads where the beads comprise a copolymer composition comprising (preferably consisting essentially of): copolymers (and processes for making them) comprising (a) at least 8.5 wt-% preferably >=20 wt-% of a higher itaconate diester (preferably dibutyl itaconateDBI); (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. 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.

Claims

1. A dispersion of polymeric beads, wherein the polymeric beads have an average diameter of between 50 m and 1500 m and comprise a copolymer containing styrene in an amount of less than 1.5% by weight of the copolymer, and wherein the copolymer comprises the following comonomers (a), (b), (c) and optionally (d): (a) 24 to 70% by weight of one or more monomers represented by the Formula (1): ##STR00009## where both R.sub.1 and R.sub.2 independently represent an optionally substituted hydrocarbo moiety having from 4 to 10 carbon atoms, (b) at least one acid functional monomer in an amount from 0.5 to 15% by weight sufficient to a achieve an acid value of the resultant copolymer of 3 to 100 mg KOH per gram of copolymer, (c) 0.01 to 10% by weight of one or more monomers represented by the Formula (2): ##STR00010## in which X.sub.1 and X.sub.2 are both O and R.sub.3 and/or R.sub.4 independently represent an optionally substituted hydrocarbo moiety having from 1 to 3 carbon atoms, and (d) optionally less than 75% by weight of monomer other than comonomers (a), (b) or (c) and does not contain styrene, butyl acrylate, 2-ethyl hexyl acrylate and/or mixtures thereof; wherein the weight percentages or amounts of comonomers (a), (b), (c) and (d) are calculated as a proportion of the total amount of components (a)+(b)+(c)+(d) which totals 100%; and wherein independently at least one of the comonomers (a), (b), (c) and/or (d) and/or the copolymer obtained from comonomers (a), (b), (c) and optionally (d) are biorenewable which is defined as comprising an amount of carbon-14 sufficient to produce a decay of at least about 1.5 disintegrations per minute per gram carbon (dpm/gC); with the provisos that: (i) when the copolymer is prepared by an emulsion polymerisation a chaser monomer is not used; (ii) the copolymer is not prepared in the presence of a seed polymer comprising a poly(itaconate ester); and (iii) the copolymer is not prepared in the presence of an initiator system comprising an organoborane amine complex.

2. The dispersion of polymeric beads as claimed in claim 1, wherein component (a) comprises dibutyl itaconate.

3. The dispersion of polymeric beads as claimed in claim 1, wherein; comonomer (a) is present in an amount of from 30 to 65% by weight and is dibutyl itaconate; comonomer (b) is present in an amount of up to 10% by weight and comprises an acid functional ethylenically unsaturated monomer and/or anhydride thereof; and comonomer (c) is present in an amount of from 1 to 10% by weight and is dimethyl itaconate and/or diethyl itaconate; and optional comonomer (d), if present, is present in an amount such that comonomers (a), (b), (c) and (d) total 100% by weight.

4. A process for preparing a dispersion of polymeric beads as claimed in claim 1, the process comprising polymerising polymer precursors comprising comonomers (a), (b), (c) and optionally (d) to obtain a copolymer dispersed in a carrier.

5. The process as claimed in claim 4, wherein the process comprises conducting suspension polymerisation of olefinically unsaturated monomers in the presence of a free radical initiator.

6. A dispersion obtained by the process according to claim 4.

7. Polymeric beads obtained by isolation of the polymeric beads from the dispersion of polymeric beads as claimed in claim 1.

8. A coating composition comprising a dispersion of the polymeric beads as claimed in claim 1.

9. A substrate and/or article having coated thereon the coating composition of claim 8, wherein the coating composition is optionally cured.

10. A method of preparing a coating composition which comprises mixing the dispersion of polymeric beads of claim 1 with components of a coating formulation.

11. A method for preparing a coated substrate and/or article comprising the steps of applying the coating composition of claim 8 to the substrate and/or article and optionally curing the coating composition in situ to form a cured coating thereon.

Description

EXAMPLE 1 (VINYL BEADS)

Example 1

(1) To a round-bottomed flask equipped with a condenser, thermometer, nitrogen inlet and mechanical stirrer are charged 950 parts of demineralised water (DMW), 1.6 parts of sodium sulphate (NS), and 7.9 parts of a 20 wt-% solution of polyacrylic acid (PAA) (weight average molecular weight (M.sub.w)=100,000 g/mole). Under constant stirring and nitrogen purge a dispersed phase consisting of 253 parts of methyl methacrylate (MMA), 190 parts of dibutyl itaconate (DBI), 190 parts of styrene (STY), 9.48 parts of dilauryl peroxide (DLP), and 1.58 parts of dodecyl mercaptane (DDM) are added. The reactor contents are heated to 75 C. and allowed to polymerize for a period of 5 hours. Next, the temperature is increased to 90 C. and the reactor contents are allowed to stir for another hour. Next, the resulting polymerization mixture is cooled down to room temperature.

(2) The polymer beads are separated from the continuous phase and washed with water and left to dry at 40 C. The polymer thus obtained has a mean particle size of 267 mm and a Tg, as determined with DSC, of 61 C.

FURTHER EXAMPLES

Examples 2 to 11

(3) Further examples for the various embodiments can be prepared according the Common method G below and with reference to the Table below. The percentages in the tables are mostly quoted to the nearest percentage and/or to 2 significant figures and thus may not total 100% due to rounding errors.

(4) Common Method G (for Beads)

(5) The total weight of monomer used in Examples 2 to 11 can be the same as the total amount used to prepare Example 1 and so for convenience the amount of monomers used in these examples could also be expressed as a weight percent of the total monomers or as an absolute mass.

(6) To the equipment described in Example 1a monomer mixture (used to prepare the polymeric beads) can be added consisting of the same ingredients described in Example 8 (or with consequent modification), other than the monomers which can be: z5% of Monomer Z4, y5% of Monomer Y5, x5% of Monomer X5 and/or w5% of Monomer W5. The rest of the process can be followed as described in Example 1 with reference to Table 1 to obtain polymeric beads analogous to those described in Example 1.

(7) TABLE-US-00001 TABLE 1 Examples 2 to 11 - polymer beads (see method G) Ex z3% Z3 y3% Y3 x3% X3 w3% W3 2 40 MMA 30 DBI 20 STY 10 BA 3 10 AA 50 DHI 20 MSTY 10 OA 4 30 EMA 40 DOI 30 OA 5 35 MMA 20 DBzI 25 STY 10 DBI 6 10 EA 60 DPhI 30 STY 7 20 MA 30 DBI 30 STY 10 DMI 8 25 MMA 35 DBI 25 STY 5 DEI 9 40 MMA 30 BPI 20 MSTY 10 40 EMA 30 BHI 30 MSTY 11 35 MMA 25 HOI 30 STY