Alkali swellable acrylic emulsions without surfactants, use thereof in aqueous formulations, and formulations containing them
AssigneeCoatex
InventorJean-Marc Suau
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Abstract
The present invention pertains to new alkali swellable thickening emulsions, free of surfactants and solvents other than water: as a result, all drawbacks related to the use of solvents, or to the formation of foam in the case of surfactants, are avoided. These new emulsions contain a certain quantity of 2-acrylamido-2-methylpropane sulfonic acid (or AMPS, CAS #: 40623-75-4). They have proven effective at thickening aqueous mediums, particularly water-based paints, paper coatings, aqueous suspensions of mineral materials, detergents, cosmetic formulations, or formulations containing a hydraulic binder.
Claims20
A method for manufacturing a direct emulsion of a polymer in water, comprising polymerizing monomer group B in a polymerization medium consisting of water and catalyst:
- wherein monomer group B consists of:
- a) 20% to 60% by weight of at least one of methacrylic acid and acrylic acid,
- b) 40% to 80% by weight of at least one ester of (meth)acrylic acid,
- c) 0.5% to 25% by weight of a monomer comprising at least one hydrophobic group,
- d) 0.05% to 22% by weight of 2-acrylamido-2-methylpropane sulfonic acid, and
- e) 0 to 1% by weight of at least one cross-linking monomer,
- provided that the total of a)+b)+c)+d)+e) is equal to 100%,
- and
- wherein the monomer comprising at least one hydrophobic group has the formula (I):
- where:
- m, n, p and q are integers and m, n, and p are less than 150, q is greater than 0, and at least one integer among m, n and p is nonzero;
- R has a polymerizable vinyl function,
- R1 and R2 are identical or different, and represent hydrogen atoms or alkyl groups,
- R′ is a hydrophobic group comprising at least 6 and at most 36 carbon atoms.
A direct emulsion of a polymer in water, consisting of water, catalyst and polymer, wherein said polymer consists of polymerized monomers of monomer group B:
- wherein monomer group B consists of:
- a) 20% to 60% by weight of at least one of methacrylic acid and acrylic acid,
- b) 40% to 80% by weight of at least one ester of (meth)acrylic acid,
- c) 0.5% to 25% by weight of the monomer comprising at least one hydrophobic group,
- d) 0.05% to 22% by weight of 2-acrylamido-2-methylpropane sulfonic acid, and
- e) 0 to 1% by weight of at least one cross-linking monomer,
- provided that the total of a)+b)+c)+d)+e) is equal to 100%,
- and
- wherein the monomer comprising at least one hydrophobic group has the formula (I):
- where:
- m, n, p and q are integers and m, n, and p are less than 150, q is greater than 0, and at least one integer among m, n and p is nonzero;
- R has a polymerizable vinyl function,
- R1 and R2 are identical or different, and represent hydrogen atoms or alkyl groups,
- R′ is a hydrophobic group comprising at least 6 and at most 36 carbon atoms.
Dependencies are inferred from the claim text.