Waterborne coating composition with improved open time

Patent metadata

Field	Value
Publication number	US-10047232-B2
Application number	US-201515110752-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Jan 17, 2014
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

The invention relates to an aqueous coating composition comprising a film-forming first polymer and a second polymer for improving the open time, the wet edge time, adhesion and/or hardness of the resulting coating. The invention further relates to said novel second polymer, its use in coating compositions for improving the open time and coalescence. The water soluble second polymer is an addition polymer comprising 25-95 wt % specific non-ionic hydrophilic monomers A and 5-75 wt % of hydrophobic monomers B which second polymer is sparingly water soluble and a solution of only said second polymer in water has a substantially Newtonian flow behavior in a wide solid contents range.

First claim

What is claimed is:

1. An aqueous coating composition comprising one or more film-forming first polymers dispersed in an aqueous solution of a water soluble second polymer, wherein the water soluble second polymer is an addition co-polymer which is a random copolymer prepared from a monomer mixture comprising:
a. 25-95 wt % non-ionic hydrophilic monomers A comprising an unsaturated group with a pendant group comprising at least one nitrogen in cyclic or linear amide or amine which is covalently bonded to the unsaturated group directly with the nitrogen (—N(−)—), a carbonyl (—(C═O)—), acetate (—O—(C═O)—) or C1-C5 alkylene (—R—),
b. 5-75 wt % of hydrophobic monomers B selected from
alkyl-, aryl- or arylalkylesters, of (meth) acrylic acid or styrenic monomers,

c. 0-20 wt % of crosslinking monomers C different from monomers A and B comprising cross-linkable groups,
d. 0-5 wt %, of hydrophilic ionic monomers D,
e. 0-20 wt %, of monomers 1 different from monomers A-D,
f. 0-10 wt % of chain transfer agents F,
wherein the total weight of A to F is 100 wt % and
wherein the water soluble second polymer comprises less than 20 wt %, relative to the total weight of the water soluble second polymer of (poly)ethylene oxide or (poly) propyleneoxide groups, and
wherein the water soluble second polymer has a weight average molecular weight Mw of from 2,000 to 200,000 g/mol, determined by gel permeation chromatography using hexafluoro-i-propanol as eluent and using polymethyl methacrylate standards,
wherein said water soluble second polymer is characterized in that a solution of only said second polymer in water has a substantially Newtonian flow behavior at solids contents ranging between 30 and 50 wt % of second polymer relative to total aqueous solution, characterized by a pseudo plasticity factor PPF of a solution comprising 50 wt % of the second polymer in water is lower than 3.0, wherein the PPF is defined as the viscosity at shear stress at 1 Pa divided by the viscosity at shear stress at 1500 Pa as determined in a shear stress flow measurement of an aqueous solution of the second polymer at room temperature (23° C.) using a viscometer with cone and plate configuration.

2. The aqueous coating composition according to claim 1 wherein the pendant group is selected from the group of i) (N)-amide ii) cyclic (N)-amide, iii) —(C═O)-amide, iv) cyclic —(C═O)-amide, v) cyclic (N)-amine, vi) cyclic (C)-amine and vii) (C═O)-esteramine wherein any amine is in non-ionic form.

3. The aqueous coating composition according to claim 1 , wherein the non-ionic hydrophilic monomers A are selected from the group of
i. Monomers comprising a pendant amide of the formula —N(—R)—C(═O)—R′, groups, (Formula 1),
ii. Monomers comprising a pendant cyclic amide of the formula —N(−)—C(═O)—R″—, wherein R″— forms a cyclic 3-6 atom ring with the N(−) (Formula 2),
iii. Monomers comprising a pendant amide of the formula —C(═O)—N(—R′)—R′ (Formula 3),
iv. Monomers comprising a pendant cyclic amide of the formula —C(═O)—N(−)—R″—, wherein R″— forms a cyclic 3-6 atom ring with the N(−) (Formula 4),
v. Monomers comprising a pendant cyclic amine group of the formula —N(−)—R″— wherein R″ forms a cyclic 3-6 atom ring with N(−) (Formula 5),
vi. Monomers comprising a pendant cyclic amine of the formula —C(−)—N—R″— wherein R″ forms a cyclic 3-6 atom ring with C(−) (Formula 6),
vii. monomers comprising a pendant ester group of the formula —C(═O)—O—R′—N(—R) 2 , (formula 7),
R is a hydrogen or a hydrocarbon, R′ is a hydrocarbon or a hydrocarbon with nitrogen or carbonyl or both and R″ is a hydrocarbon or a hydrocarbon with at least one of nitrogen, oxygen or carbonyl in or on the cyclic ring, wherein each R, R′ and R″ is chosen independently of each other and each hydrocarbon comprises 5 or less connected carbon atoms and wherein any amine is in non-ionic form.

4. The aqueous coating composition according to claim 1 , wherein the monomers A in the water soluble second polymer are chosen from the group of N-vinyl pyrrolidone, 2-(N,N-dimethylamino)ethyl(meth)acrylate, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth) acrylamide, N-vinyl imidazole, N-vinylcaprolactam, N-vinylsuccinimide, N-vinylpiperidone, 2-vinylpyridine, N-vinyl maleimide, N-vinyl citraconimide, N-vinyl phthalimide, 2-propenamide, N-[3-(dimethylamino)-2,2-dimethylpropyl]-methacrylamide, methacrylamido ethyl ethylene urea, 2-morpholinoethyl methacrylate, 2-morpholinoethyl, N-vinyl carbazole, N-vinyl acetamide, N-vinylpyrrolidone, N-vinyl caprolactam and 2-(N,N-dimethylamino)-ethyl(meth)acrylate.

5. The aqueous coating composition according to claim 1 , wherein at least 60 wt %, of all non-ionic hydrophilic monomers A in the second polymer are monomers specified in claim 3 or 4 .

6. The aqueous coating composition according to claim 1 , wherein at least 60 wt %, of all hydrophobic monomers B in the second polymer are methyl-, ethyl- or butyl (meth)acrylate or mixtures thereof.

7. The aqueous coating composition according to claim 1 , wherein the hydrophilic monomers A are characterised by a Hoy solubility parameter of the corresponding homopolymer of said monomers between 20.0 and 30.0 (J/m 3 ) 1/2 .

8. The aqueous coating composition according to claim 1 , wherein the hydrophobic monomers B are characterised by a Hoy solubility parameter of the corresponding homopolymer of said monomers between 16.0 and 26.0 (J/m 3 ) 1/2 .

9. The aqueous coating composition according to claim 1 , wherein the second polymer has an overall Hoy solubility parameter between 21.0 and 24.0 (J/m 3 ) 1/2 .

10. The aqueous coating composition according to claim 1 , wherein the cross-linkable monomers C are chosen from the group of unsaturated monomers comprising hydroxy, epoxy, amine or carbonyl crosslinking functional groups.

11. The aqueous coating composition according to claim 1 , wherein the ionic monomers D, are in an amount less than 2 or 1 wt %.

12. The aqueous coating composition according to claim 1 , wherein the water-soluble second polymer is obtained by addition polymerization of a monomer mixture comprising:
a. 25 to 95 wt % (N)-vinyl pyrrolidone, (N)-vinylcaprolactam or N,N-dimethylamino acrylamide monomers A,
b. 5 to 75 wt % C1-C4 alkyl(meth)acrylate monomers B,
c. 0 to 20 wt % cross-linking monomers C with a functional group for cross-linking,
d. no ethylenically unsaturated acid functional monomers D or precursors thereof,
e. 0-10 wt % monomers E different from monomers A to D
f. 0 to 10 wt % of chain transfer agents F,
wherein the sum of a) to f) is 100 wt %.

13. The aqueous coating composition according to claim 1 , wherein the water soluble second polymers have a glass transition temperature Tg of from −30 to 180° C.

14. The aqueous coating composition according to claim 1 , wherein the water soluble second polymer has a weight average molecular weight Mw of from 5,000 to 100,000 g/mol determined by gel permeation chromatography using hexafluoro-i-propanol as eluent and using polymethyl methacrylate standards.

15. The aqueous coating composition according to claim 1 , wherein the one or more film-forming first polymers are selected from the group consisting of vinyl, polyurethane, polyurea-urethane, polyester, alkyd and epoxy polymers and hybrids or blends thereof, and ambient curing film-forming first polymers with a curing temperature between 5 and 50° C.

16. The aqueous coating composition according to claim 1 , wherein the one or more film-forming first polymers are polymers having a weight average a molecular weight Mw between 2000 and 2,000,000 g/mole determined

Assignees

• Allnex Netherlands Bv

Inventors

• Akkerman Jaap Michiel
• Roelofs André
• Van Der Horst Richard
• Van Egmond Robert

Classifications

• C08G18/6547

  the low-molecular compounds being compounds of group C08G18/36 or hydroxylated esters of higher fatty acids of C08G18/38 · CPC title

• C09D5/022

  Emulsions, e.g. oil in water · CPC title

• C08G18/348

  Hydroxycarboxylic acids · CPC title

• C08L75/04

  Polyurethanes · CPC title

• C08L2201/54

  Aqueous solutions or dispersions · CPC title