Stable aqueous dispersions of particles of vinylidene fluoride polymer
AssigneePPG Industries, Inc.
InventorsDennis W. Carson, Ralph C. Gray, Glenn W. Luckock
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Abstract
Coating compositions based on stable aqueous dispersions of particles of vinylidene fluoride polymer are prepared by bringing into admixture unstabilized particles of vinylidene fluoride polymer, liquid organic active solvent for the vinylidene fluoride polymer, liquid nonsolvent, which may be liquid organic nonsolvent, water or a combination of liquid organic nonsolvent and water, and, if not present in the liquid nonsolvent, water. The mixing is conducted such that the particles of vinylidene fluoride polymer are wetted by the dispersion vehicle, yet the particles are not substantially solubilized by the active solvent.
Claims28
A method for producing a stable aqueous dispersion of particles of vinylidene fluoride polymer comprising bringing into admixture:
- (a) unstabilized particles of vinylidene fluoride polymer,
- (b) dispersion vehicle which is an interpolymer of monoethylenically unsaturated monomers wherein said monomers comprise acrylic ester monomer and monoethylenically unsaturated acid and which is at least partially neutralized,
- (c) liquid organic active solvent for said vinylidene fluoride polymer wherein said active solvent is miscible with water and wherein said active solvent would itself dissolve vinylidene fluoride polymer particles at some temperature below about 40.degree. C.,
- (d) liquid organic nonsolvent for said vinylidene fluoride polymer wherein said organic nonsolvent is miscible with water and with said active solvent, and
- (e) water;
- wherein:
- (f) said active solvent is brought into contact with said particles in the presence of said organic nonsolvent,
- (g) said dispersion vehicle is at least partially neutralized before said dispersion vehicle is brought into contact with said water, and
- (h) the amounts of said active solvent and said organic nonsolvent are such that such particles are wetted by said dispersion vehicle but said particles are not substantially solubilized by said active solvent.
A method for producing a stable aqueous dispersion of particles of vinylidene fluoride polymer comprising bringing into admixture:
- (a) unstabilized particles of vinylidene fluoride polymer,
- (b) dispersion vehicle which is an interpolymer of monoethylenically unsaturated monomers wherein said monomers comprise acrylic ester monomer and monoethylenically unsaturated acid and which is at least partially neutralized,
- (c) liquid organic active solvent for said vinylidene fluoride polymer wherein said active solvent is miscible with water and wherein said active solvent would itself dissolve vinylidene fluoride polymer particles at some temperature below about 40.degree. C., and
- (d) water;
- wherein:
- (e) said active solvent is brought into contact with said particles in the presence of said water,
- (f) said dispersion vehicle is at least partially neutralized before said dispersion vehicle is brought into contact with said water, and
- (g) the amounts of said active solvent and said water are such that said particles are wetted by said dispersion vehicle but said particles are not substantially solubilized by said active solvent.
A method for producing a stable aqueous dispersion of particles of vinylidene fluoride polymer comprising bringing in admixture:
- (a) unstabilized particles of vinylidene fluoride polymer,
- (b) dispersion vehicle which is an interpolymer of monoethylenically unsaturated monomers wherein said monomers comprise acrylic ester monomer and monoethylenically unsaturated acid and which is at least partially neutralized,
- (c) liquid organic active solvent for said vinylidene fluoride polymer wherein said active solvent is miscible with water and wherein said active solvent would itself dissolve vinylidene fluoride polymer particles at some temperature below about 40.degree. C.,
- (d) liquid organic nonsolvent for said vinylidene fluoride polymer wherein said nonsolvent is miscible with water and with said active solvent, and
- (e) water;
- wherein:
- (f) said active solvent is brought into contact with said particles in the presence of said organic nonsolvent and said water,
- (g) said dispersion vehicle is at least partially neutralized before said dispersion vehicle is brought into contact with said water, and
- (h) the amounts of said active solvent, said organic nonsolvent and said water are such that said particles are wetted by said disperson vehicle but said particles are not substantially solubilized by said active solvent.
Dependencies are inferred from the claim text.