Coating composition for stain resistant coatings

Abstract

A coating composition includes: (a) a first acrylic polymer formed from a reaction mixture including: (i) an ethylenically unsaturated monomer including an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and (b) a second acrylic polymer different from the first acrylic polymer, where the second acrylic polymer (b) has a Mw of at least 100,000 Da. A method of preparing such a coating composition and coatings and coated substrates formed therefrom are also disclosed. Coatings formed from the disclosed coating composition may exhibit improved stain resistance.

Claims

1. A coating composition comprising: (a) a first acrylic polymer formed from a reaction mixture comprising: (i) an ethylenically unsaturated monomer comprising an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and (b) a second acrylic polymer different from the first acrylic polymer, wherein the second acrylic polymer (b) has a Mw of at least 100,000 Da.

2. The coating composition of claim 1, wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.

3. The coating composition of claim 1, wherein the reactive solvent (ii) is completely consumed in an addition reaction with the ethylenically unsaturated monomer (i).

4. The coating composition of claim 1, wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality.

5. The coating composition of claim 1, wherein the first acrylic polymer (a) has an average particle size of less than 0.5 microns.

6. The coating composition of claim 1, wherein the coating composition is essentially free of a non-reactive organic solvent.

7. The coating composition of claim 1, wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.

8. The coating composition of claim 1, wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer.

9. The coating composition of claim 1, wherein the second acrylic polymer (b) comprises a latex acrylic polymer.

10. The coating composition of claim 1, wherein the first acrylic polymer (a) has a Mw of up to 70,000 Da.

11. The coating composition of claim 1, wherein the first acrylic polymer (a) has a Tg of from 50 C. to 100 C.

12. A coating formed from the coating composition of claim 1, the coating exhibiting an improved stain resistance compared to a coating formed from the same coating composition not including the first acrylic polymer (a).

13. The coating of claim 12, wherein the coating exhibits a stain rating of at least 45 according the Stain Resistance Test Method.

14. A substrate at least partially coated with a coating formed from the coating composition of claim 1.

15. The substrate of claim 14, wherein the substrate comprises an architectural component.

16. A method of preparing a coating composition for imparting improved stain resistance comprising: reacting to form (a) a first acrylic polymer: (i) an ethylenically unsaturated monomer comprising an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and mixing (b) a second acrylic polymer different from the first acrylic polymer (a) with the first acrylic polymer (a) to form a coating composition, wherein the second acrylic polymer (b) has a Mw of at least 100,000.

17. The method of claim 16, wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality.

18. The method of claim 16, wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.

19. The method of claim 16, wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer.

20. The method of claim 16, wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.

Description

EXAMPLES

(1) Illustrating the invention are the following examples that are not to be considered as limiting the invention to their details.

Polymer Example A

(2) A water dispersible polymer (Polymer A) was prepared with the following ingredients:

(3) TABLE-US-00001 TABLE 1 Ingredients Amount (gram) Charge 1: Reactive Solvent.sup.1 256.59 Charge 2: Di-tertiary-amyl peroxide 18.2 (premixed) Reactive Solvent.sup.1 22.5 Dipropylene glycol monomethyl ether 7.87 Charge 2A: Dipropylene glycol monomethyl ether 5.98 (Rinse) Charge 3: Iso-bornyl acrylate 283.54 (premixed) Hydroxy ethyl methacrylate 213.23 Alpha-methyl styrene dimer 26.47 Ethyl hexyl acrylate 45.67 Acrylic acid 125.98 Charge 3A: Dipropylene glycol monomethyl ether 9.9 (Rinse) Charge 4: Di-methyl ethanol amine 51.7 Charge 5: Deionized water 2132.3 .sup.1CARDURA E10P glycidyl ester, available from Hexion (Columbus, OH)

(4) To a suitable reaction vessel equipped with a stirrer, reflux condenser, thermometer, heating mantle, and nitrogen inlet, Charge 1 was added at ambient temperature (20 C. to 27 C.). The temperature was then increased to 160 C., at which time a premix of Charge 2 was added over 270 minutes, and Charge 3 was added over 240 minutes. Upon completion of Charges 2 and 3, Charge 2A and Charge 3A were added as a rinse for Charge 2 and Charge 3, respectively, followed by a hold for an additional 60 minutes. Thereafter the reaction mixture was cooled to 120 C. At this temperature Charge 4 was added over 10 minutes, followed by a 10 minute hold. The polymeric product (Polymer A) thus formed was then diluted with Charge 5. The final product had a solids of 31.0 wt. % and a Mw of 9,389 Da. Non-volatile content (solids) was measured by comparing initial sample weights to sample weights after exposure to 110 C. for 1 hour. Polymer A had a Brookfield Viscosity of 186 CPS, measured at 25 C. on a Brookfield Viscometer DV-II+Pro using spindle #3 at 100 RPM. Polymer A had an average particle size of 35.2 nm as measured by reading the z-average particle size measured by dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS.

Polymer Example B

(5) Polymer B was prepared in the same way as Polymer A, except, isobornyl acrylate was replaced by additional ethyl hexyl acrylate. The final product had a solids content of 31.94 wt. % (1 hour at 110 C.) and a Mw of 14,089 Da. Polymer B had a Brookfield Viscosity of 254 CPS, measured at 25 C. on a Brookfield Viscometer DV-II+Pro using spindle #3 at 100 RPM. Polymer B had an average particle size of 95 nm as measured by reading the z-average particle size measured by dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS.

Polymer Example C

(6) Polymer C was prepared in the same way as Polymer A, except, isobornyl acrylate was replaced by additional ethyl hexyl acrylate and 5.4 wt. % (based on total solids of Polymer C) of polydimethyl siloxane acrylate (molecular weight 5,000 Da, available from Shin Etsu, Chemical Company (Tokyo, Japan)) was added in the initial charge of CARDURA E. The final product had a solids content of 31.5 wt. % (1 hour at 110 C.) and a Mw of 12,201 Da. Polymer C had a Brookfield Viscosity of 400 CPS, measured at 25 C. on a Brookfield Viscometer DV-II+Pro using spindle #3 at 100 RPM. Polymer C had an average particle size of 38.6 nm as measured by reading the z-average particle size measured by dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS.

Polymer Example D

(7) Polymer D was prepared in the same way as Polymer A, except 5.4 wt. % (based on total solids of Polymer D) of polydimethyl siloxane acrylate (molecular weight 5,000 Da (as reported by manufacturer), available from Shin Etsu, Chemical Company (Tokyo, Japan)) was used in the initial charge of CARDURA E. The final product had a solids content of 31.6 wt. % (1 hour at 110 C.) and a Mw of 9,170 Da. Polymer D had a Brookfield Viscosity of 76 CPS, measured at 25 C. on a Brookfield Viscometer DV-II+Pro using spindle #3 at 100 RPM. Polymer D had an average particle size of 82 nm as measured by reading the z-average particle size measured by dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS.

Polymer Example E

(8) A water dispersible polymer (Polymer E) was prepared with the following ingredients:

(9) TABLE-US-00002 TABLE 2 Ingredients Amount (gram) Charge 1: Diethylene glycol monobutyl ether 157.5 Deionized water 16.5 Charge 2: Tertiary butyl peroxy acetate 10.9 (premixed) Diethylene glycol monobutyl ether 105.0 Charge 2A: Diethylene glycol monobutyl ether 7.5 (Rinse) Charge 3: Styrene 190.5 (premixed) Butyl acrylate 222.2 Butyl methacrylate 114 Poly-dimethyl siloxane acrylate 54.2 Acrylic acid 56.5 Charge 3A: Diethylene glycol monobutyl ether 16.5 (Rinse) Charge 4: Di-methyl ethanol amine 69.8 Charge 5: Deionized water 900.0

(10) To a suitable reaction vessel equipped with a stirrer, reflux condenser, thermometer, heating mantle, and nitrogen inlet, Charge 1 was added at ambient temperature (20 C. to 27 C.). The temperature was then increased to reflux (105 C.), at which time a premix of Charge 2 and Charge 3 were added over 180 minutes. Upon completion of Charges 2 and 3, Charge 2A and Charge 3A were added as a rinse for Charge 2 and Charge 3, respectively, followed by a hold for an additional 60 minutes. Thereafter the reaction mixture was cooled to 80 C. At this temperature Charge 4 was added over 20 minutes, followed by a 10 minute hold. The polymeric product thus formed (Polymer E) was then diluted with Charge 5. The final product had a solids content of 30.8 wt. % (1 hour at 110 C.) and a Mw of 46,388 Da. Polymer E had a Brookfield Viscosity of 1,020,000 CPS, measured at 25 C. on a Brookfield Viscometer DV-II+Pro using spindle #7 at 2 RPM. Polymer E had an average particle size of 180 nm as measured by reading the z-average particle size measured by dynamic light scattering (DLS) with a Malvern Zetasizer Nano ZS.

(11) The following Base Formulation and Stain Resistant Test Method were used in the Examples.

Base Formulation

(12) Coating compositions were prepared according to the Base Formulation in Table 3 with different resin blends (cf. Formulation Examples 1-13 described below), keeping the total resin solids constant by weight. The grind ingredients were mixed using a high-speed Cowles disperser at sufficient speed to create a vortex where the blade meets the paint. After addition of the matting agent, the grind process resumed for 20 minutes, followed by adding the letdown ingredients using a conventional lab mixer and mixing for 30 minutes after the last addition.

(13) TABLE-US-00003 TABLE 3 Item Amount (gram) Grind Water 100.0 PANGEL S9.sup.2 3.0 TYLOSE HX 6000.sup.3 YG4 2.0 DREWPLUS T-4507.sup.4 2.0 TAMOL 731A.sup.5 5.0 ZETASPERSE 179.sup.6 6.0 MINEX 4.sup.7 92.0 Letdown Water 71.0 ACRYSOL RM-2020 NPR.sup.8 17.0 TRONOX CR-826S.sup.9 387.0 DREWPLUS T-4507.sup.4 8.0 Resin Blend 430.0 OPTIFILM enhancer 400.sup.10 15.0 ACTICIDE MBS.sup.11 1.2 .sup.2Magnesium silicate rheology modifier, available from The Carey Company (Addison, IL) .sup.3Hydroxyethylcellulose rheology modifier, available from SETylose USA (Plaquemine, LA) .sup.4Mineral oil defoamer, available from Ashland (Columbus, OH) .sup.5Dispersant available from The Dow Chemical Company (Midland, MI) .sup.6Nonionic surfactant, available from Evonik Industries AG (Essen, Germany) .sup.7Aluminum silicate matting agent, available from The Cary Company (Addison, IL) .sup.8Hydrophobically modified ethylene oxide urethane rheology modifier, available from The Dow Chemical Company (Midland, MI) .sup.9Rutile titanium dioxide slurry, available from Tronox Limited (Stamford, CT) .sup.10Coalescent, available from The Eastman Chemical Company (Kingsport, TN) .sup.11Biocide, available from Thor Specialties, Inc. (Shelton, CT)

Stain Resistance Test Method

(14) The Stain Resistance Test Method is a more challenging, modified version of ASTM D4828 to target stain removal using fewer scrub cycles Films were prepared by drawing down the coating composition onto black Leneta scrub panels (Form P121-10N) using a 7-mil horseshoe drawdown bar. The films were dried at ambient laboratory conditions for 7 days before stain application. Before applying stains, color was measured of the unstained coated panel using a Datacolor 850 spectrophotometer using 9 mm size aperture. The following stains were applied to the paint films via one-inch strips of filter paper saturated with the following fluids: red wine (Holland House red cooking wine), grape juice (Welch's grape juice), java concentrate (Pur Java concentrateHonduran Dark Roast), and hot coffee (Kirkland Signature 100% Colombian (Dark Roast-fine grind)) (70 C.). The following stains were directly applied to the paint films: mustard (French's mustard), red lipstick (CoverGirl 305 Hot lipstick), green crayon (Crayola), graphite powder (Alfa Aesar graphite99.9% pure), and Leneta staining medium (ST-1). After 30 minutes, the lipstick and Leneta medium were wiped off, and the paint films were rinsed and placed in a washability machine (Gardner Abrasion Tester). A damp cellulosic sponge containing 10 g of water and 6 g of SOFT SCRUB (cleanser, Henkel Corporation (Dusseldorf, Germany)) was placed in a 1000 g holder, and the panels were scrubbed for 6 cycles. After rinsing the panels and drying for at least 2 hours, color was again measured for the coated panels using the spectrophotometer so that a E color change for each coated panel could be generated by the spectrophotometer. Each of the 9 stains was rated on an integer scale of 0 for no stain removal to 10 for complete stain removal based on the measured E color change of the coated panel using the following Table 4:

(15) TABLE-US-00004 TABLE 4 Delta E Color Change Red Grape Java Hot Green Lenata Rating Wine Juice Concentrate Coffee Mustard Lipstick Crayon Graphite Oil 0 >6.30 >6.00 >4.00 >6.00 >25.00 >32.00 >12.20 >26.50 >22.00 1 5.69- 5.07- 3.62-4.00 5.33- 22.29- 27.32- 10.91- 22.01- 18.51- 6.30 6.00 6.00 25.00 32.00 12.20 26.50 22.00 2 5.11- 4.50- 3.23-3.61 4.73- 19.58- 22.63- 9.61- 17.68- 16.01- 5.68 5.06 5.32 22.28 27.31 10.90 22.00 18.50 3 4.53- 3.93- 2.84-3.22 4.12- 16.85- 18.01- 8.31- 14.96- 13.50- 5.10 4.49 4.72 19.57 22.62 9.60 17.67 16.00 4 3.39- 3.36- 2.45-2.83 3.52- 12.24- 14.51- 7.01- 12.24- 11.01- 4.52 3.92 4.11 16.84 18.00 8.30 14.95 13.49 5 2.81- 2.79- 2.07-2.44 2.92- 9.52- 11.01- 5.70- 9.52- 8.51- 3.38 3.35 3.51 12.23 14.50 7.00 12.23 11.00 6 2.23- 2.22- 1.68-2.06 2.32- 6.80- 7.51- 4.41- 6.80- 6.01- 2.80 2.78 2.91 9.51 11.00 5.69 9.51 8.50 7 1.66- 1.65- 1.29-1.67 1.71- 4.25- 4.51- 3.11- 4.25- 3.81- 2.22 2.21 2.31 6.79 7.50 4.40 6.79 6.00 8 1.09- 1.08- 0.90-1.28 1.11- 1.91- 1.91- 1.81- 1.91- 1.91- 1.65 1.64 1.70 4.24 4.50 3.10 4.24 3.80 9 0.50- 0.50- 0.50-0.89 0.51- 0.57- 0.51- 0.51- 0.51- 0.51- 1.08 1.07 1.10 1.90 1.90 1.80 1.90 1.90 10 <0.50 <0.50 <0.50 <0.50 <0.56 <0.50 <0.50 <0.50 <0.50

(16) A stain rating ranging from 0 to 90 was obtained by summing the rating for each individual stain.

Formulation Examples 1-5

(17) Comparative Examples 1, 6, and 11 included the same coating composition having 100 wt. % RHOPLEX SG-30 in place of the resin blend in the Base Formulation shown in Table 3. Coating compositions for Examples 2-5 were formed by blending Polymers A-D, respectively, at 30% by weight based on total resin solids with RHOPLEX SG-30, as the resin blend of the Base Formulation as shown in Table 3. Coating compositions for Examples 7-10 were formed by blending Polymers A-D (first acrylic polymer (a)), respectively, at 50% by weight based on total resin solids with RHOPLEX SG-30 (second acrylic polymer (b), as the resin blend of the Base Formulation as shown in Table 3.

(18) The stain ratings for Examples 1-5 were determined as a first set according to the Stain Resistance Test Method. The stain ratings for Examples 6-10 were determined as a second set according to the Stain Resistance Test Method. The stain ratings for Examples 11-13 were determined as a third set according to the Stain Resistance Test Method.

(19) As can be seen in Table 5, an over 55% improvement in stain resistance was achieved for Examples 2-5 compared to Comparative Example 1. An additional boost in stain resistance was observed when the acrylic dispersions were blended at 50% on total resin solids in the Base Formulation in Examples 7-10 as shown in Table 6. Over 65% improvement in stain resistance was achieved using these blends compared to the Base Formulation including only the Base Acrylic control resin (Comparative Example 6).

(20) TABLE-US-00005 TABLE 5 Formulations containing 30% First Acrylic Polymer (a)/70% Second Acrylic Polymer (b) CE. 1 RHOPLEX Ex. 2 Ex. 3 Ex. 4 Ex. 5 SG-30 Poly- Poly- Poly- Poly- Stain Only mer A mer B mer C mer D Wine 3 7 7 8 7 Grape Juice 4 9 7 8 9 Java Concentrate 4 5 7 6 6 Hot Coffee 1 5 5 4 4 Mustard 2 3 3 3 3 Lipstick 3 6 5 7 7 Green Crayon 9 10 10 10 9 Graphite 6 9 9 9 9 Leneta Oil 7 9 8 8 8 Total 39 63 61 63 62 % Improvement 62% 56% 62% 59%

(21) TABLE-US-00006 TABLE 6 Formulations containing 50% First Acrylic Polymer (a)/50% Second Acrylic Polymer (b) CE. 6 RHOPLEX Ex. 7 Ex. 8 Ex. 9 Ex. 10 SG-30 Poly- Poly- Poly- Poly- Stain Only mer A mer B mer C mer D Wine 4 8 9 9 9 Grape Juice 6 9 9 9 10 Java Concentrate 5 7 7 8 6 Hot Coffee 2 6 5 5 6 Mustard 1 2 2 2 4 Lipstick 3 8 7 8 8 Green Crayon 8 9 10 9 10 Graphite 5 9 9 9 9 Leneta Oil 6 9 9 9 9 Total 40 67 67 68 71 % Improvement 68% 68% 70% 78%

(22) In comparison, there is less improvement in stain resistance when the inventive resins are synthesized using a conventional solvent-based method as in Polymer Example E. Table 7 compares formulations containing acrylic dispersions blended at 50% on total resin solids in the Base Formulation. Comparative Example 12 shows a 49% improvement in stain resistance using resin synthesized via the conventional method, whereas Example 13 (the identical coating composition compared to Example 9) containing the inventive resin shows a larger 74% improvement in stain resistance. Moreover, the inventive resin is much lower in molecular weight and viscosity, making it easier to process in formulation.

(23) TABLE-US-00007 TABLE 7 Formulations containing comparative 50% First Acrylic Polymer (a)/50% Second Acrylic Polymer (b) CE. 11 RHOPLEX CE. 12 Ex. 13 Stain SG-30 Only Polymer E Polymer C Wine 4 8 9 Grape Juice 5 8 8 Java Concentrate 5 7 7 Hot Coffee 2 4 4 Mustard 2 4 4 Lipstick 3 2 7 Green Crayon 8 8 10 Graphite 4 9 10 Leneta Oil 6 8 9 Total 39 58 68 % Improvement 49% 74%

(24) In view of the foregoing description and examples the present invention thus relates inter alia to the subject matter of the following clauses and claims though being not limited thereto.

(25) Clause 1: A coating composition comprising: (a) a first acrylic polymer formed from a reaction mixture comprising: (i) an ethylenically unsaturated monomer comprising an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and (b) a second acrylic polymer different from the first acrylic polymer, wherein the second acrylic polymer (b) has a Mw of at least 100,000 Da.

(26) Clause 2: The coating composition of clause 1, wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.

(27) Clause 3: The coating composition of clause 1 or 2, wherein the reactive solvent (ii) is completely consumed in an addition reaction with the ethylenically unsaturated monomer (i).

(28) Clause 4: The coating composition of any of clauses 1-3, wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality, such as the reactive solvent (ii) comprising a glycidyl ester of an aliphatic saturated carboxylic acid.

(29) Clause 5: The coating composition of any of clauses 1-4, wherein the first acrylic polymer (a) has an average particle size of less than 0.5 microns.

(30) Clause 6: The coating composition of any of clauses 1-5, wherein the coating composition is essentially free of a non-reactive organic solvent.

(31) Clause 7: The coating composition of any of clauses 1-6, wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.

(32) Clause 8: The coating composition of any of clauses 1-7, wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer, such as acrylic and/or methacrylic acid.

(33) Clause 9: The coating composition of any of clauses 1-8, wherein the second acrylic polymer (b) comprises a latex acrylic polymer.

(34) Clause 10: The coating composition of any of clauses 1-9, wherein the first acrylic polymer (a) has a Mw of up to 70,000 Da.

(35) Clause 11: The coating composition of any of clauses 1-10, wherein the first acrylic polymer (a) has a Tg of from 50 C. to 100 C.

(36) Clause 12: A coating formed from the coating composition of any of clauses 1-11, the coating exhibiting an improved stain resistance compared to a coating formed from the same coating composition not including the first acrylic polymer (a).

(37) Clause 13: The coating of clause 12, wherein the coating exhibits a stain rating of at least 45.

(38) Clause 14: A substrate at least partially coated with a coating formed from the coating composition of any of clauses 1-11.

(39) Clause 15: The substrate of clause 14, wherein the substrate comprises an architectural component.

(40) Clause 16: A method of preparing a coating composition for imparting improved stain resistance comprising: reacting to form (a) a first acrylic polymer: (i) an ethylenically unsaturated monomer comprising an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenic ally unsaturated monomer (i); and (iii) a second monomer reactive with ethylenic ally unsaturated monomer (i); and mixing (b) a second acrylic polymer different from the first acrylic polymer (a) with the first acrylic polymer (a) to form a coating composition, wherein the second acrylic polymer (b) has a Mw of at least 100,000.

(41) Clause 17: The method of clause 16, wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality, such as the reactive solvent (ii) comprising a glycidyl ester of an aliphatic saturated carboxylic acid.

(42) Clause 18: The method of clause 16 or 17, wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.

(43) Clause 19: The method of any of clauses 16-18, wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer, such as acrylic and/or methacrylic acid.

(44) Clause 20: The method of any of clauses 16-19, wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.

(45) Clause 21: A method for improving stain resistance of a substrate comprising: providing a coating composition comprising: (a) a first acrylic polymer formed from a reaction mixture comprising: (i) an ethylenically unsaturated monomer comprising an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and (b) a second acrylic polymer different from the first acrylic polymer (a), wherein the second acrylic polymer (b) has a Mw of at least 100,000; and applying the coating composition to a substrate.

(46) Whereas particular aspects of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.