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US 12,595,323 B2Granted
Vinyl acetate-based copolymer dispersions with small particle size
AssigneeCelanese International Corporation
InventorsHarmin Müller, Matthias Seib, Argiri Tsami-Schulte, Bastiaan Van Voorn
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Abstract
Aqueous copolymer dispersions are useful for incorporating into primer formulations. The aqueous copolymer dispersions comprise a vinyl acetate-based copolymer and have a particle size of less than or equal to 120 nanometers. The resulting primer formulations have good penetration in various substrates, and/or water resistance/binding properties.
Claims20
A method for preparing an aqueous copolymer dispersion by emulsion polymerization, the method comprising:
- a) pre-charging a reactor with a pre-charge comprising vinyl acetate monomer, a second monomer, wherein the second monomer is ethylene, butyl acrylate, vinyl nodecanoate, or 2-ethylhexyl acrylate, an ionic-group containing monomer, water, and an emulsifier system, wherein the pre-charge comprises from 0.5 to 20% of the total amount of vinyl acetate and at least 30% of the total amount of the second monomer;
- b) adding a remaining amount of vinyl acetate monomer and the second monomer to the reactor;
- c) adding an initiator system to the reactor;
- and
- d) conducting the polymerization reaction at a temperature of >65° C. to form an aqueous vinyl acetate-second monomer copolymer dispersion having a solids content from 5 to 55% and a particle size of dw less than or equal to 120 nm as measured by dynamic light scattering at 90° (Contin Fit);
- wherein the emulsifier system is present in an amount from 4 to 8 pphm;
- and
- wherein monomers in the copolymer dispersion consist of a) the vinyl acetate monomer, b) the second monomer, c) the ionic-group containing monomer, d) optionally one or more non-functional monomer(s) and e) optionally one or more functional monomer(s) comprising a silane, glycidyl methacrylate, a vinyl sulfonate, methacrylic acid, acrylic acid, or combinations thereof.
5 more elements
A method for preparing an aqueous copolymer dispersion by emulsion polymerization, the method comprising:
- a) pre-charging a reactor with vinyl acetate monomer, ethylene monomer, an ionic-group containing monomer, water, and an emulsifier system, wherein the pre-charge comprises from 0.5 to 20% of the total amount of vinyl acetate and at least 30% of the total amount of ethylene;
- b) adding a remaining amount of vinyl acetate monomer and ethylene monomer to the reactor;
- c) adding an initiator system to the reactor;
- and
- d) conducting the polymerization reaction at a temperature of >65° C. to form an aqueous vinyl acetate-ethylene copolymer dispersion having a solids content from 5 to 55% and a particle size of dw less than or equal to 120 nm as measured by dynamic light scattering at 90° (Contin Fit);
- wherein the emulsifier system is present in an amount from 4 to 8 pphm;
- and
- wherein monomers in the copolymer dispersion consist of a) the vinyl acetate monomer, b) the ethylene monomer, c) the ionic-group containing monomer, d) optionally one or more non-functional monomer(s) and e) optionally one or more functional monomer(s) comprising a silane, glycidyl methacrylate, a vinyl sulfonate, methacrylic acid, acrylic acid, or combinations thereof.
5 more elements
Dependencies are inferred from the claim text.