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US 9,040,065 B2Granted
Preparation of polyacrylates by emulsion polymerization
AssigneeBASF SE
InventorsMaximilian Angel, Peter Hossel
Life of this patent
Estimating the term…
Abstract
The present invention relates to a process for the preparation of polymers comprising carboxyl groups by emulsion polymerization and the use of the polymers obtainable by this process, for example as thickeners. Moreover, the invention relates to thickener dispersions obtainable by the process and to the use thereof for modifying the rheology of paper coating slips, textile printing pastes, drugs, cosmetic preparations, detergents, cleansing compositions, or foods.
Claims19
A process for the preparation of polymers, the polymers comprising in a polymerized-in form,
- a. M1a+M2a=30 to 70% by weight of an ester of (meth)acrylic acid with a C1-C4-alcohol;
- b. M1b+M2b=30 to 70% by weight of (meth)acrylic acid;
- c. M1c+M2c=0.1 to 20% by weight of monomer substituted with at least one C8-C30-radical;
- and
- M1d+M2d=0 to 20% by weight of monomers different from a) to c),
- the process comprising emulsion polymerization with a first polymerization stage followed by a second polymerization stage,
- wherein the first polymerization stage includes
- i) providing an initial charge comprising the monomer part amounts M1a, M1b, M1c, and M1d, water, and optionally a surface-active agent, to form a first monomer mixture;
- ii) heating the first monomer mixture (i) to a temperature in the range of about 30 to 120° C.;
- and
- iii) adding a polymerization initiator to form a first reaction mixture, and
- wherein the second polymerization stage includes
- iv) adding the monomer part amounts M2a, M2b, M2c, and M2d to the first reaction mixture (iii) to form a second reaction mixture;
- and
- v) after-treatment of the second reaction mixture (iv),
- wherein
- M1b/M1a≧0.4 and
- M1b/M1a<M2b/M2a and
- ∑
- i
- =
- a
- d
-
-
- M
-
-
- 1
-
- i
- ≤
- 40
-
- %
-
-
- by
-
-
- weight
- ,
- wherein
- M1i are the representative weight fractions of the monomers a) and d), which are present in the reaction space during the first polymerization stage and M2i are the representative weight fractions of the monomer a) to d), which are added during the second polymerization stage and the sum of all weight fractions
- ∑
- i
- =
- a
- d
-
-
- M
-
-
- 1
-
- i
- +
- ∑
- i
- =
- a
- d
-
-
- M
-
-
- 2
-
- i
- =
- 100
-
- %
-
-
- by
-
-
- weight
- .
79 more elements
Dependencies are inferred from the claim text.