Water-based coating compositions that resist dirt pickup
Water-based compositions containing a low VOC coalescent, a latex or water-dispersible polymer are described.
1. A low VOC paint, comprising:
a multistage latex polymer comprising a surfactant and polymer particles comprising a homopolymer or copolymer and including at least one of an acrylate or a methacrylate with a first stage having a Tg of about 0° C. to 70° C. and a second stage having a Tg of about −20° C. to 0° C.;
methyl-o-benzoyl benzoate;
a pigment; and
at least one coalescent having the formula:
(R 1 —O) n —P(═O)—[—O—(X) m —O—R 2 ] 3—n
wherein:
R 1 and R 2 are each independently H, an aliphatic group having at least 3 and less than 100 carbon atoms, an aromatic group having at least 3 and less than 100 carbon atoms;
X is a divalent hydrocarbyl group having at least one and no more than 12 carbon atoms;
m is an integer between 0 and 15; and
n is an integer between 0 and 3,
with the proviso that R 1 and R 2 together do not include any aliphatic unsaturated carbon-carbon bonds;
wherein the coalescent has a volatile organic content of less than about 15 wt %, is nonreactive in the paint, and is dispersible in the paint to form a uniform mixture.
2. The paint of claim 1 , wherein the paint forms a coalesced film at a temperature of about 4° C. to about 10° C.
3. The paint of claim 1 , wherein the coalescent has a volatile organic content of no greater than about 11 wt % and has a number average molecular weight of less than about 500.
4. The paint of claim 1 , wherein:
n is 0;
R 2 is an aliphatic group having 3 to 12 carbon atoms;
X is a divalent hydrocarbyl group having at least one and no more than 12 carbon atoms; and
m is an integer between 0 and 13.
5. The paint of claim 4 , wherein n is 0, R 2 is —C 4 H 9 ; X is —CH 2 —; and m is 2.
6. The paint of claim 2 , wherein the coalescent has the following structure:
7. The paint of claim 1 , comprising a mixture of coalescents, wherein the mixture has VOC of less than about 50 wt % and wherein at least one of the coalescents is nonreactive in the paint, has a VOC of less than about 15 wt %, is dispersible in the paint to form a uniform mixture, and has the recited formula; and wherein the mixture of coalescents is selected to facilitate, and used in an amount that facilitates, the formation of a polymer film of the latex polymer at a temperature of less than 25° C.
8. The paint of claim 1 , wherein the at least one coalescent is selected from tributyl phosphate, tris(butoxyethyl) phosphate, isopropylated triphenyl phosphate, alkyl diphenyl phosphate, triaryl phosphate ester, t-butylated triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, linear alkyl diphenyl phosphate, and mixtures thereof.
9. The paint of claim 1 , wherein a dried coating made from the paint demonstrates scrub resistance of at least that of TEXANOL.
10. The paint of claim 1 , wherein a dried coating made from the paint demonstrates corrosion resistance.
11. The paint of claim 9 , wherein the paint is stable over time.
12. The paint of claim 9 , wherein the one or more coalescents are present in a sufficient amount to facilitate the formation of a polymer film of a latex polymer at a temperature less than 25° C.
13. A low VOC paint, comprising:
a multistage latex polymer comprising a surfactant and polymer particles comprising a homopolymer or copolymer and including at least one of an acrylate or a methacrylate with a first stage having a Tg of about 0° C. to 70° C. and a second stage having a Tg of about −20° C. to 0° C.;
methyl-o-benzoyl benzoate;
a pigment; and
at least one coalescent having the formula:
(R 1 —O) n —P(═O)—[—O—(X) m —O—R 2 ] 3−n
wherein:
R 1 and R 2 are each independently H, an aliphatic group having at least 3 and less than 100 carbon atoms, an aromatic group having at least 3 and less than 100 carbon atoms;
X is a divalent hydrocarbyl group having at least one and no more than 12 carbon atoms;
m is an integer between 0 and 15; and
n is an integer between 0 and 3,
with the proviso that R 1 and R 2 together do not include any aliphatic unsaturated carbon-carbon bonds;
wherein the coalescent has a volatile organic content of less than about 15 wt %, is nonreactive in the paint, and is dispersible in the paint to form a uniform mixture; and
wherein the one or more coalescents are present in a sufficient amount to facilitate the formation of a polymer film of the multistage latex polymer at a temperature less than 25° C.
14. The paint of claim 13 , wherein the coalescent has a volatile organic content of no greater than about 11 wt % and has a number average molecular weight of less than about 500.
15. The paint of claim 13 , wherein:
n is 0;
R 2 is an aliphatic group having 3 to 12 carbon atoms;
X is a divalent hydrocarbyl group having at least one and no more than 12 carbon atoms; and
m is an integer between 0 and 13.
16. The paint of claim 13 , comprising a mixture of coalescents, wherein the mixture has VOC of less than about 50 wt % and wherein at least one of the coalescents is nonreactive in the paint, has a VOC of less than about 15 wt %, is dispersible in the paint to form a uniform mixture, and has the recited formula; and wherein the mixture of coalescents is selected to facilitate, and used in an amount that facilitates, the formation of a polymer film of the latex polymer at a temperature of less than 25° C.
17. The paint of claim 13 , wherein the at least one coalescent is selected from tributyl phosphate, tris(butoxyethyl) phosphate, isopropylated triphenyl phosphate, alkyl diphenyl phosphate, triaryl phosphate ester, t-butylated triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, linear alkyl diphenyl phosphate, and mixtures thereof.