Remediation of yellowing in a coatings formulation containing a sorbate ester or a sorbamide coalescent

Patent metadata

Field	Value
Publication number	US-9714359-B2
Application number	US-201514732925-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Jun 16, 2014
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

The present invention is a composition comprising a stable aqueous dispersion of polymer particles and a sorbate ester, which is a liquid at 20° C. and has a molecular weight in the range of 125 to 500 g/mol. The composition of the present invention provides a way to enhance film formation of coatings prepared using relatively high T g latexes without the aid of high volatile organic content (VOC) coalescents.

First claim

The invention claimed is:

1. A composition comprising a stable aqueous dispersion of polymer particles, from 0.5 to 35 weight percent of a sorbate ester or sorbamide coalescent, based on the weight of the polymer particles, and from 10 ppm to 1 weight percent of a radical mediator, based on the weight of the composition, wherein the coalescent is imbibed in the polymer particles, wherein at least 60% of the coalescent is incorporated into the polymer particles; and wherein radical mediator is a hindered amine, a hindered N-oxide, a thiol, an amino polycarboxylic acid or a salt thereof, a polyphosphate, or a phenol, or a combination thereof.

2. The composition of claim 1 wherein the coalescent is characterized by the following formula:

where R is a C 1 -C 20 linear or branched alkyl group optionally functionalized with ether, thioether, amine, hydroxyl, ester, phenyl, alkyenyl groups, or combinations thereof; C(O)X is an ester group or an amide group; and the coalescent is a liquid at 20° C.

3. The composition of claim 2 wherein R is —(CH 2 —CH(R 1 )—O) n —R 2 , —CH(R 1 )—CH 2 —O—R 2 , or linear or branched —R 3 —OR 2 ;
where R 1 is H, C 1 -C 6 -alkyl, —CH 2 OH, or phenyl;
R 2 is H, C 1 -C 6 -alkyl, benzyl, or CH 3 CH═CH—CH═CH═C(O)—; allyl; —C(O)—CR 4 ═CH 2 ;
R 3 is a bivalent C 4 -C 10 -linear or branched alkyl or hydroxyalkyl group;
R 4 is H or CH 3 ;
X is O or NR 5 , where R 5 is H or C 1 -C 6 -alkyl; and
n is 1 to 7;
wherein the concentration of the coalescent is from 1 to 20 weight percent, based on the weight of the polymer particles and the coalescent.

4. The composition of claim 1 which contains from 20 ppm to 0.5 weight percent of the radical mediator, based on the weight of the composition, wherein the coalescent is a sorbate ester having a molecular weight from 126 g/mol to 500 g/mol, wherein the radical mediator is a hindered N-oxide, a phenol, or a thiol.

5. The composition of claim 4 wherein the radical mediator is 4-acetamido-2,2,6,6-tetramethylpiperidine-1-oxyl or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

6. The composition of claim 4 wherein the radical mediator is pentaerythritol tetrakis(3-mercaptoproprionate).

7. The composition of claim 4 wherein the radical mediator is p-methoxyphenol.

8. The composition of claim 2 wherein the coalescent is selected from the group consisting of:

wherein the coalescent is at least 90% imbibed into the polymer particles.

9. The composition of claim 1 which is non-pigmented.

10. The composition of claim 1 which further includes one or more materials selected from the group consisting of rheology modifiers; opaque polymers; fillers; colorants; pigments, dispersants; wetting aids; dispersing aids; dispersant adjuvants; chelating agents; surfactants; co-solvents; additional coalescing agents; defoamers; preservatives; anti-mar additives; flow agents; leveling agents; slip additives; and neutralizing agents.

Assignees

• Rohm & Haas

Inventors

• Arumugam Selvanathan
• Ell John
• Even Ralph C
• Rowe Brandon

Classifications

• C08K5/0008 Primary

  Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59 · CPC title

• C08K3/0008

  Chemistry & Metallurgy · mapped topic

• C08K5/005

  Stabilisers against oxidation, heat, light, ozone · CPC title

• C08K5/101

  of monocarboxylic acids · CPC title

• C08K5/20

  Carboxylic acid amides · CPC title