SUBSTRATE MARKING SYSTEM

Abstract

A marked substrate including a solid substrate surface such as, for example, a road surface having disposed thereon a first coating including a pigment and a first binder polymer, the first coating having a dry film thickness of from 10 microns to 5000 microns; the first coating having disposed thereon, a clear second coating including from 75% to 100%, by weight based on the weight of the clear coating, nanosilica and from 0% to 25%, by weight based on the weight of the clear coating, second binder polymer; the clear second coating having a dry film thickness of from 1 to 10 microns is provided. A method for providing the marked substrate is also provided.

Claims

1. A method for providing a marked substrate comprising: (a) providing a solid substrate surface; (b) applying thereon a first coating composition comprising a pigment and a first binder polymer; (c) applying to said first coating composition an aqueous clear second coating composition comprising from 75% to 100%, by dry weight based on the dry weight of said clear coating, aqueous dispersion of nanosilica and from 0% to 25%, by dry weight based on the dry weight of said clear coating, aqueous dispersion of second binder polymer; said first coating having a dry film thickness of from 10 microns to 5000 microns and said clear second coating having a dry film thickness of from 1 to 10 microns; and (d) drying, or allowing to dry, said second aqueous coating composition.

2. The method of claim 1 wherein step (b) is: (b) applying thereon a first aqueous coating composition comprising a pigment and a first binder polymer;

3. The method of claim 2 wherein, after step (b) and before step (c), the following step is effected: drying, or allowing to dry, said first aqueous coating composition.

4. The method of claim 1 wherein said solid substrate surface is composed of material is masonry, tar, asphalt, blacktop, resins, concrete, cement, stone, stucco, tiles, wood, polymeric materials, one or more layers of fresh or aged coating or marking already applied on said surface, or combinations thereof.

5. The method of claim 1 wherein said first binder polymer and said second binder polymer are emulsion polymers and, independently, have a DSC Tg of from 10 C. to 110 C.

6. The method of claim 1 wherein the first coating is applied in a geometric configuration.

7. The method of claim 1 wherein the first costing is in the form of a line or lines, a series of dashes or dots, various symbols, or words or letters.

8. The method of claim 1 wherein the substrate is a highway, street, driveway, sidewalk, runway, taxiing area, tarmac area, parking lot, rooftop, indoor factory floor, floor inside shopping mall, or playground.

9. The method of claim 1 wherein the first coating is a visible informative coating.

10. The method of claim 1 wherein the first binder polymer and the second binder polymer are thermoplastics

11. The method of claim 1 wherein the substrate is an indoor or outdoor solid surface, said surface exposed to pedestrians, moving vehicles, tractors, or aircraft continuously, constantly or intermittently.

12. The method of claim 1 wherein the first binder polymer is a polymer of one or more monomers selected from methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, ureido-functional (meth)acrylates and acetoacetates, acetamides or cyanoacetates of (meth)acrylic acid; styrene; substituted styrenes; olefins; vinyl toluene; butadiene; amino-group containing monomers; monoethylenically unsaturated acetophenone or benzophenone derivatives; vinyl esters; vinyl chloride, vinylidene chloride, and N-vinyl pyrollidone; (meth)acrylonitrile; N-alkylol (meth)acrylamide and optionally one or more additional monomers selected from allyl (meth)acrylate, diallyl phthalate, 1,4-butylene glycol di(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, divinyl benzene, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl itaconate, monomethyl fumarate, monobutyl fumarate, and maleic anhydride; sulfur- and phosphorous-containing acid monomers, amine monomers, imine monomers, and monomers bearing functionality that can be converted to amine functionality.

13. The method of claim 1 wherein the second binder polymer is a polymer of one or more monomers selected from methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, ureido-functional (meth)acrylates and acetoacetates, acetamides or cyanoacetates of (meth)acrylic acid; styrene; substituted styrenes; olefins; vinyl toluene; butadiene; amino-group containing monomers; monoethylenically unsaturated acetophenone or benzophenone derivatives; vinyl esters; vinyl chloride, vinylidene chloride, and N-vinyl pyrollidone; (meth)acrylonitrile; N-alkylol (meth)acrylamide and optionally one or more additional monomers selected from allyl (meth)acrylate, diallyl phthalate, 1,4-butylene glycol di(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, divinyl benzene, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, monomethyl itaconate, monomethyl fumarate, monobutyl fumarate, and maleic anhydride; sulfur- and phosphorous-containing acid monomers, amine monomers, imine monomers, and monomers bearing functionality that can be converted to amine functionality.

14. The method of claim 1 wherein the substrate is a highway, street, driveway, sidewalk, runway, taxiing area, tarmac area, or parking lot.

Description

EXAMPLE 1. PROVIDING AND EVALUATING A MARKED SUBSTRATE

Formation of First Aqueous Coating Composition

[0052] The following ingredients (in g) were added in order with moderate shear mixing:

TABLE-US-00001 First binder polymer 366.0 FOAMASTER 8034 2.4 TERGITOL 15-S-40 2.9 AS-238 dispersant 8.2 TIOXIDE TR-92 96.3 DURCAL 2 152.0 DURCAL 10 304.0 Ethanol 11.8 NOPCO 8034 0.3 TEXANOL 38.0 Water 18.1 FOAMASTER is a product of Cognis, Inc.; TERGITOL and OROTAN are products of The Dow Chemical Company; TIOXIDE is a product of Huntsman International LLC; DURCAL is a product of Omya SAS; NOPCO is a product of San Nopco LTD; TEXANOL is a product of Eastman Chemical Company.

[0053] The first binder polymer was an emulsion polymer having a DSC Tg of 45 C. The first aqueous coating composition had a volume solids of 58%, weight solids of 74%, an ICI viscosity of 3.4 poise, and a pH of 10.

Formation of Second Aqueous Coating Composition

[0054] The following ingredients (in g) were added in order with moderate shear mixing:

TABLE-US-00002 KLEBOSOL 30R12 (30%) 799.2 (Unmodified aqueous silica dispersion) Second binder polymer (Tg = 105 C.) (37.5%) 159.9 Benzophenone (40%) 0.6 Water 40.0 TEGOFOAMEX LAE 497 0.3 KLEBOSOL is a product of AZ Electronic Materials S.A.; TEGOFOAMEX is a product of Evonik Industries AG.

[0055] The first aqueous coating composition was drawndown to a wet film thickness of 300 microns and, when dried prior to applying the second coating composition, dried for 7 days at ambient temperature to a dry film thickness of 180-200 microns. The second aqueous coating composition was spray-applied to the first coating at a wet film thickness of 15 g/m.sup.2. Alternate aqueous unmodified silica dispersions were substituted at the same solids level.

[0056] Table 1.1 Evaluation of appearance of marked substrates using unmodified silica dispersions of varying particle size of the unmodified silica dispersion in the second coating composition

TABLE-US-00003 Particle size Y reflectance value (nm) 9 15 30 55 Application Wet on wet 79.9 80.9 82 78.4 type Wet on dry 82.3 82.2 81.9 80.1

[0057] Table 1.2 Evaluation of black heel marking resistance of marked substrates using various unmodified silica dispersions of varying particle size in the second coating composition

TABLE-US-00004 Rating (0 the worst - 10 the best) Silica LEVASIL LEVASIL LEVASIL LEVASIL KLEBOSOL KLEBOSOL Dispersion None 300 200 100 50 30R12 30R50 Application Wet on dry 1 8 8 8 6 6 6 type Wet on wet 2 5 6 2 4 5 LEVASIL is a product of Akzo Nobel N.V.

[0058] Marked substrates of the invention exhibit superior dirt resistance as measured by the black heel marking test relative to a comparative example on the same solid substrate having disposed thereon only the same first coating composition.

EXAMPLE 2. PROVIDING A MARKED SUBSTRATE

Formation of First Aqueous Coating Composition

[0059] The following ingredients (in g) were added in order with moderate shear mixing:

TABLE-US-00005 First binder polymer 366.0 FOAMASTER 8034 2.4 TERGITOL 15-S-40 2.9 AS-238 dispersant 8.2 TIOXIDE TR-92 96.3 DURCAL 2 152.0 DURCAL 10 304.0 Ethanol 11.8 NOPCO 8034 0.3 TEXANOL 38.0 Water 18.1

[0060] The first binder polymer was an emulsion polymer having a DSC Tg of 45 C. The first aqueous coating composition had a volume solids of 58%, weight solids of 74%, an ICI viscosity of 3.4 poise, and a pH of 10.

Formation of Second Aqueous Coating Composition

[0061] The following ingredients (in g) were added in order with moderate shear mixing:

TABLE-US-00006 KLEBOSOL 30R12 (30%) 799.2 (Unmodified aqueous silica dispersion) Second binder polymer (Tg = 105 C.) (37.5%) 159.9 Benzophenone (40%) 0.6 Water 40.0 TEGOFOAMEX LAE 497 0.3

[0062] The first aqueous coating composition was drawndown to a wet film thickness of 300 microns and, when dried prior to applying the second coating composition, dried for 7 days at ambient temperature to a dry film thickness of 180-200 microns. The second aqueous coating composition was spray-applied to the first coating.

[0063] Table 2.1 Evaluation of black heel marking resistance and appearance of marked substrates using various unmodified silica dispersions of varying particle size in the second coating composition

TABLE-US-00007 Particle size of unmodified colloidal silica (nm) in second coating composition Supplier 1 Supplier 2 None 9 15 30 55 12 50 Black heel mark Visual rating Wet on wet 2 5 6 2 4 5 Wet on dry 1 8 8 8 6 6 6 White reflectance Wet on wet 79.9 80.9 82 78.4 79.5 80.4 Wet on dry 73 82.3 82.2 81.9 80.1 81.9 82.9

[0064] Table 2.2 Evaluation of dirt (red iron oxide) resistance of marked substrates using an aqueous unmodified silica dispersion of 12 nm particle size in the second coating composition

TABLE-US-00008 Example; wet on Example; wet on Comparative dry application wet application First coating Application rate: 300 microns wet compositon Second coating None Application rate: 16 g/m.sup.2 wet composition Test with red iron oxide Rating after washing: Under running Ref. +++ ++ water Same with sponge Ref. + + Scrub machine Ref. ++ + with sponge Scrub machine Ref. ++ + with abrasive surface

[0065] Marked substrates of the invention exhibit superior dirt resistance as measured by the black heel marking test and the dirt (red iron oxide) resistance test relative to a comparative example on the same solid substrate having disposed thereon only the same first coating composition.