| CPC C08F 2/38 (2013.01) [C08F 2/22 (2013.01); C08F 212/08 (2013.01); C08F 218/08 (2013.01); C08F 220/14 (2013.01); C08F 220/1804 (2020.02); C09D 5/02 (2013.01); C09D 133/12 (2013.01); C08F 2438/03 (2013.01)] | 20 Claims |
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1. A process for preparing an aqueous polymer dispersion, comprising:
a. providing an initial composition comprising:
i. about 0.5 to about 6 parts of a selective hydrophilic macro-RAFT agent of formula (I); and
ii. about 0.1 to about 30 parts of at least one first monomer;
iii. about 0.05 to about 0.5 parts of a free radical initiator; and
iv. water,
b. reacting the initial composition from step (a) under suitable conditions to generate a seed composition, wherein the seed composition comprises a polymer formed from the selective hydrophilic macro-RAFT agent of formula (I) and the at least one first monomer; and
c. combining the seed composition from step (b) with:
i. about 0.05 to about 0.8 parts of at least one initiator; and
ii. about 0.1 to about 99 parts of at least one second monomer, under conditions suitable for reacting the seed composition with the at least one second monomer to form the aqueous polymer dispersion;
wherein the at least one first monomer and at least one second monomer are different, wherein the first monomer comprises styrene monomers, acrylic monomers, vinyl ester monomers, or mixtures thereof,
wherein the at least one second monomer comprises styrene monomers, acrylic monomers, vinyl ester monomers, or mixtures thereof;
wherein the process is substantially free of surfactants; and
wherein the selective hydrophilic macro-RAFT agent of formula (I) is defined as follows:
(R11)x-Z11—C(═S)—Z12-[A]-R12 (I)
wherein:
Z11 represents C, N, O, S or P,
Z12 represents S or P,
R11 and R12, which may be identical or different, represent:
an optionally substituted alkyl, acyl, aryl, alkene or alkyne group (i), or
a saturated or unsaturated, optionally substituted or aromatic carbon-based ring (ii), or
a saturated or unsaturated, optionally substituted heterocycle (iii), these groups and rings (i), (ii) and (iii) may be optionally substituted with substituted phenyl groups, substituted aromatic groups or groups: alkoxycarbonyl or aryloxycarbonyl (—COOR), carboxyl (—COOH), acyloxy (—O2CR), carbamoyl (—CONR2), cyano (—CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, phthalimido, maleimido, succinimido, amidino, guanidino, hydroxyl (—OH), amino (—NR2), halogen, allyl, epoxy, alkoxy (—OR), S-alkyl, S-aryl, groups of hydrophilic or ionic nature selected from the group of alkali metal salts of carboxylic acids, alkali metal salts of sulphonic acid, polyalkylene oxide (PEO or PPO) chains and cationic substituents (quaternary ammonium salts),
R represents an alkyl or aryl group,
x corresponds to the valency of Z11, or alternatively x is 0, in which case Z11 represents a phenyl, alkene or alkyne radical, optionally substituted with an optionally substituted alkyl; acyl; aryl; alkene or alkyne group; an optionally substituted, saturated, unsaturated, or aromatic, carbon-based ring; an optionally substituted, saturated or unsaturated heterocycle; alkoxycarbonyl or aryloxycarbonyl (—COOR); carboxyl (COOH); acyloxy (—O2CR); carbamoyl (—CONR2); cyano (—CN); alkylcarbonyl; alkylarylcarbonyl; arylcarbonyl; arylalkylcarbonyl; phthalimido; maleimido; succinimido; amidino; guanidino; hydroxyl (—OH); amino (—NR2); halogen; allyl; epoxy; alkoxy (—OR), S-alkyl; S-aryl groups; groups of hydrophilic or ionic nature selected from the group of alkali metal salts of carboxylic acids, alkali metal salts of sulphonic acid, polyalkylene oxide (PEO or PPO) chains and cationic substituents (quaternary ammonium salts); and
A represents a monoblock, diblock or triblock polymer comprising at least a first block which is hydrophilic in nature and an optional second block which is hydrophobic or hydrophilic in nature.
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