HIGH MOLECULAR WEIGHT POLYMERIC DISPERSIONS MANUFACTURED UNDER CONTROLLED ADIABATIC CONDITIONS
Methods for manufacturing a polymer dispersion, polymer dispersions, and their use are provided herein. The methods of manufacturing the polymer dispersion comprise the steps of providing a reaction mixture in an aqueous medium comprising a polymeric dispersant and a monomer composition comprising radically polymerizable monomers, and subjecting the monomer composition in the reaction mixture to a radical polymerization to synthesize a dispersed polymer so as to form the polymer dispersion, wherein step of subjecting the monomer composition is performed under controlled adiabatic conditions. These polymer dispersions are designated as water-in-water (w/w) polymer dispersions.
1 . A method for manufacturing a polymer dispersion comprising the steps of
C) providing a reaction mixture in an aqueous medium comprising
a) a polymeric dispersant and
b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group of one or more of a non-ionic ethylenically unsaturated monomer, a cationic ethylenically unsaturated monomer or an amphiphilic ethylenically unsaturated monomer;
D) subjecting the monomer composition in the reaction mixture to a radical polymerization to synthesize a dispersed polymer and to form the polymer dispersion,
wherein step B) is performed under controlled adiabatic conditions.
2 . The method according to claim 1 , wherein step B) is performed under controlled adiabatic conditions by sequentially or simultaneously adding a redox initiator system.
3 . The method according to claim 1 , wherein the oxidizing agent has a redox potential of from 0.6 to 2.0 V; and/or the reducing agent has a redox potential of from −2 to 0.3 V.
4 . The method according to claim 1 , wherein the weight ratio between the reducing agent and the oxidizing agent is below 35:1 and above 2:1.
5 . The method according to claim 1 , wherein the radically polymerizable monomers are selected from the group of one or more of the following:
i. a non-ionic monomer of formula (I)
where
R 1 means hydrogen or methyl;
R 2 and R 3 are, independently of each other, hydrogen, C 1 -C 5 -alkyl or C 1 -C 5 -hydroxyalkyl,
ii. a cationic monomer of formula (II)
where
R 1 means hydrogen or methyl;
Z 1 is O, NH or NR 4 , wherein R 4 means C 1 -C 4 -alkyl, and
Y is one of
where
Y 0 and Y 1 are a C 1 -C 6 alkylene group, optionally substituted with one or more hydroxy groups;
Y 2 , Y 3 , Y 5 , Y 6 , Y 7 independently of each other, are each C 1 -C 6 -alkyl; and
Z − is a counterion;
iii. an amphiphilic monomer of formulae (III) or (IV)
where
Z 1 is O, NH, NR 4 , wherein R 4 means C 1 -C 4 -alkyl,
R 1 means hydrogen or methyl,
R 8 is a C 1 -C 6 alkylene group,
R 5 and R 6 are, independently of each other, each C 1 -C 6 -alkyl,
R 7 is a C 8 -C 32 alkyl, optionally substituted with one or more hydroxy groups, and
Z − is a counterion; or
where
Z 1 is O, NH, NR 4 , wherein R 4 means C 1 -C 4 -alkyl,
R 1 means hydrogen or methyl,
R 10 means hydrogen, C 8 -C 32 alkyl, C 8 -C 32 aryl and/or C 8 -C 32 aralkyl,
R 9 is a C 1 -C 6 alkylene group, and
n is an integer between 1 and 50; or
iv. an ethylenically unsaturated cross-linker containing 2, 3, 4 or 5 ethylenically unsaturated groups.
6 . The method according to claim 1 , wherein the monomer composition comprises the non-ionic monomer of formula (I) being selected from those in which R 1 means hydrogen or methyl, and R 2 and R 3 are both hydrogen, hydrogen and C 1 -C 3 alkyl, hydrogen and hydroxyethyl, or both C 1 -C 3 alkyl, and/or the cationic monomer of formula (II) being selected from those in which R 1 means hydrogen or methyl, and Z 1 is O, NH or NR 4 , wherein R 4 means methyl, Y 1 is C 2 -C 6 alkylene, Y 5 , Y 6 and Y 7 are all methyl, and Z − is a halogen.
7 . The method according to claim 1 , wherein the monomer composition comprises
at least 5 wt.-% of the non-ionic monomer of formula (I)
where
R 1 means hydrogen or methyl;
R 2 and R 3 are, independently of each other, hydrogen, C 1 -C 5 -alkyl or
C 1 -C 5 -hydroxyalkyl;
at least 5 wt.-% of the cationic monomer of formula (II)
where
R 1 means hydrogen or methyl;
Z 1 is O, NH or NR 4 , wherein R 4 means C 1 -C 4 -alkyl, and
Y is one of
where
Y 0 and Y 1 are a C 1 -C 6 alkylene group, optionally substituted with one or more hydroxy groups;
Y 2 , Y 3 , Y 5 , Y 6 , Y 7 independently of each other, are each C 1 -C 6 -alkyl; and
Z − is a counterion;
0 to 1.25 wt.-% of the ethylenically unsaturated cross-linker containing 2, 3, 4 or 5 ethylenically unsaturated groups; and
optionally, further ethylenically unsaturated monomers.
8 . The method according to claim 1 , wherein the ethylenically unsaturated cross-linker is a cross-linker containing 2, 3 or 4 ethylenically unsaturated groups.
9 . The method according to claim 1 , wherein the polymeric dispersant is a homopolymer made of the cationic monomer of formula (II)
where
R 1 means hydrogen or methyl;
Z 1 is O, NH or NR 4 , wherein R 4 means C 1 -C 4 -alkyl, and
Y is one of
where
Y 0 and Y 1 are a C 1 -C 6 alkylene group, optionally substituted with one or
more hydroxy groups;
Y 2 , Y 3 , Y 5 , Y 6 , Y 7 independently of each other, are each C 1 -C 6 -alkyl; and
Z − is a counterion.
10 . The method according to claim 1 , wherein the polymeric dispersant is a homopolymer made of a (meth)acryloyl amidopropyl trimethylammonium salt or a (meth)acryloyl oxyethyl trimethylammonium salt.
11 . The method according to claim 1 , wherein the ratio of the polymeric dispersant to the dispersed polymer in the polymer dispersion is in the range of 0.45:1 to 1:0.9.
12 . The method according to claim 1 , wherein the polymer dispersion has a salt content of less than 15 wt.%, based on the total weight of the polymer dispersion.
13 . A polymer dispersion comprising
c) a polymeric dispersant and
d) dispersed polymer derived from a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group of one or more of a non-ionic ethylenically unsaturated monomer, a cationic ethylenically unsaturated monomer, or an amphiphilic ethylenically unsaturated monomer;
wherein the polymeric dispersant has a weight average molecular weight M w as determined by size exclusion chromatography of 40,000 to less than 150,000 g/mol; and/or wherein the polymer dispersion has a bulk viscosity below 6,700 mPas as measured at 20° C. with a Brookfield viscometer with spindle 4 and speed 10 rpm.
14 . A polymer dispersion obtained by a method for manufacturing the polymer dispersion according to claim 1 comprising the steps of
A) providing a reaction mixture in an aqueous medium comprising
a) a polymeric dispersant and
b) a monomer composition comprising radically polymerizable monomers, wherein the radically polymerizable monomers are selected from the group of one or more of a non-ionic ethylenically unsaturated monomer, a cationic ethylenically unsaturated monomer, or an amphiphilic ethylenically unsaturated monomer;
B) subjecting the monomer composition to a radical polymerization to synthesize a dispersed polymer and to form the polymer dispersion,
wherein step B) is performed under controlled adiabatic conditions.