Coatings with antimicrobial copper glass nanoparticles and diol compounds
11814532 · 2023-11-14
Assignee
Inventors
Cpc classification
C09D133/08
CHEMISTRY; METALLURGY
International classification
Abstract
Antimicrobial compositions and coating compositions including antimicrobial compositions including copper glass nanoparticles and an additive alkyldiol compound. Coating compositions including the antimicrobial composition exhibit enhanced antimicrobial efficacy and improved coatings performance characteristics including ability to appropriately shade for a base, starting masstone color, as compared to coatings compositions containing copper glass nanoparticles and no such alkyldiol additives.
Claims
1. A coating composition comprising: (a) a binder polymer; (b) copper glass nanoparticles, wherein each nanoparticle comprises a glass shell and a copper core, the copper core comprising copper oxidation states Cu.sup.0, Cu.sup.1+, Cu.sup.2+, or combinations thereof, and the glass shell comprising a porous SiO2 structure that at least partially surrounds the copper core; (c) an alkyldiol additive; and (d) a carrier liquid, wherein the copper glass nanoparticles are present in the coating composition in an amount of 1 g/gallon coating composition to 4 g/gallon coating composition; and wherein the alkyldiol additive is selected from the group consisting of 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-hexanediol blended with methylbenzyl alcohol, 1,2-octanediol blended with methylbenzyl alcohol, 1,2-decanediol blended with phenoxyethanol, or blends thereof and wherein the alkyldiol additive is present at 2000 to 5000 ppm by weight.
2. The coating composition of claim 1 further comprising at least 10% by weight of a pigment, wherein the pigment is selected from calcium carbonate, talc, clay, silicates, aluminum silicates, calcium metasilicates, aluminum potassium silicates, magnesium silicates, barium sulfates, nepheline syenite, feldspar, zinc oxides, sulfides, titanium dioxide and mixtures thereof.
3. The coating composition of claim 2, wherein the pigment is titanium dioxide in an amount of at least 10% by weight.
4. The coating composition of claim 3, further comprising at least one pigment other than titanium dioxide in an amount up to 10% by weight.
5. The coating composition of claim 1, wherein the alkyldiol additive comprises a blend of 1,2-hexanediol and 1,2-octanediol.
6. The coating composition of claim 1, wherein the alkyldiol additive is present at 3000 to 4000 ppm by weight.
7. The coating composition of claim 1, wherein the binder polymer is present at 7% to 30% by weight.
8. The coating composition of claim 6, wherein the binder polymer is selected from acrylics, vinyl acrylics, styrene acrylics and mixtures thereof, and wherein the carrier liquid is water.
9. The coating composition of claim 1, further comprising a pigment dispersing agent and at least 10% by weight of a pigment.
10. The coating composition of claim 9, wherein the pigment dispersing agent is a solvent or surfactant and is present at lower than 0.5% by weight.
11. The coating composition of claim 1, further comprising one or more additional biocides selected from metal ion containing compounds, polymeric biocides, heterocyclic compounds, phenols, organometallics, aldehydes, proteins, peroxygens, alcohols, enzymes, polypeptides, quaternary ammonium compounds, and halogen releasing compounds.
12. The coating composition of claim 1, further wherein the coating composition passes the ASTM D2574 – 16 test for in-can paint preservation.
13. A coated article comprising: (a) substrate surface; and (b) a coating on at least a portion of the substrate surface, said coating formed from a paint composition comprising: a binder polymer; copper glass nanoparticles, wherein each nanoparticle comprises at a glass shell and a copper core, the copper core comprising copper oxidation states Cu.sup.0, Cu.sup.1+, Cu.sup.2+, or combinations thereof, and the glass shell comprising a porous SiO.sub.2 structure that at least partially surrounds the copper core; an alkyldiol additive; and water, wherein the copper glass nanoparticles are present in the paint composition in an amount of 1 g/gallon paint composition to 4 g/gallon paint composition; and wherein the alkyldiol additive of the coating on at least a portion of the substrate surface is selected from the group consisting of 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-hexanediol blended with methylbenzyl alcohol, 1,2-octanediol blended with methylbenzyl alcohol, 1,2-decanediol blended with phenoxyethanol, or blends thereof and wherein the alkyldiol additive is present at 2000 to 5000 ppm by weight.
14. The coated article of claim 13, wherein the alkyldiol additive of the coating on at least a portion of the substrate surface comprises a blend of 1,2-hexanediol and 1,2-octanediol.
15. The coated article of claim 13, wherein the binder polymer of the coating on at least a portion of the substrate surface is a blend of a vinyl acrylic resin and an acrylic resin.
Description
DETAILED DESCRIPTION OF THE INVENTION
(1) It has been found in accordance with the present invention, surprisingly, that coatings compositions containing an antimicrobial composition containing copper glass nanoparticles and an additive comprising an alkyldiol compound, exhibit enhanced antimicrobial efficacy and improved coatings performance characteristics including ability to appropriately shade for a base, starting masstone color, as compared to coatings compositions containing copper glass nanoparticles and no such alkyldiol additives. Adequate antimicrobial efficacy and improved coatings performance characteristics including the ability to appropriately shade are provided without the need for the use of a conventional biocide like isothiazolinones.
(2) The present invention comprises, in one embodiment, a paint composition comprising water, latex binder resin, pigment, and additives, wherein such additives include, but are not limited to, copper glass nanoparticles and an alkyldiol additive.
(3) In another embodiment, the present invention comprises a paint composition comprising an organic solvent, an acrylic-amino, alkyd, polyurethane, epoxy or other compatible resin, pigment, and additives, wherein such additives include, but are not limited to, copper glass nanoparticles and an alkyldiol additive.
(4) In another embodiment, the invention comprises a coated article, whereby the article is coated with the copper glass nanoparticle and alkyldiol additive-containing coatings compositions disclosed herein. In certain embodiments, the coatings composition is formulated for coating outside or inside surfaces of an architectural structure. In other embodiments, the coatings composition is formulated for coating the inside of a beverage can, for covering a steel coil, for coating a plastic, for lining an industrial tank (e.g., water tanks, chemical bulk tanks, etc.), or for protective and marine applications.
(5) In some useful embodiments, the copper glass nanoparticles constitute 1 g/gallon to 5 g/gallon of the coatings composition. In other useful embodiments, the copper glass nanoparticles constitute 1 g/gallon to 4 g/gallon of the coatings composition, in other embodiments 1.2 g/gallon to 3.8 g/gallon, in still others 2 g/gallon to 3.5 g/gallon, and in still others 2 to 3 g/gallon.
(6) In some useful embodiments, the alkyldiol additives, comprising a diol compound, are present in a coatings composition at 1000 to 7500 ppm by weight of the composition. In other useful embodiments, the alkyldiol additives are present at 2000 to 5000 ppm by weight, in other embodiments 2500 to 4500 ppm, and in still others 3000 to 4000 ppm.
Copper Glass Nanoparticles
(7) The copper glass nanoparticles useful in the present invention have individual antimicrobial effect, without the aid of other biocides. Such copper glass nanoparticles may be core/shell nanoparticles with a glass shell and copper ion core as is described in Pat. Application Publication No. US 2015/0225572 A1 (“the ‘572 Application”). As described in the ‘572 Application, the preferred state of copper ion is the Cu.sup.+1 state with Cu.sup.0 and Cu.sup.+2 optionally present. In some embodiments, the glass shell may comprise a borophosphosilicate glass with a porous S.sub.1O.sub.2 structure that at least partially surrounds the copper. One such useful copper glass nanoparticle is called Guardiant™, available as a powder from Corning Inc. (Corning, NY).
Alkyldiol Additives
(8) Suitable alkyldiol additives for the present invention and copper glass nanoparticles have been found, surprisingly, to enhance antimicrobial effect in coatings containing the copper glass nanoparticle powders, thus making possible the formulation of coatings with sufficiently low copper glass nanoparticle concentration to avoid discoloration. Such alkyldiol additives comprise a diol compound.
(9) Exemplary alkyldiol additives of the present invention include linear, C5 - C11 alkyl diols including 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,2-nonanediol, 1,2-decanediol, and blends thereof. Alkyldiol additives may also be blends of diol compounds and an mono or aryl alcohol. Further exemplary alkyldiol additive compounds and blends are shown below in TABLE 1. Percents in TABLE 1 refer to weight percent of the alkyldiol additive.
(10) TABLE-US-00001 Exemplary Alkyldiol Additives Chemistry Structure(s) 1,2-Hexanediol (50%) and 1,2-Octanediol (50%) (Caprylyl Glycol) Blend
Carrier Liquid
(11) Coatings compositions of the present invention may comprise a carrier liquid prior to application to a substrate. The carrier liquid may be water, include water, or be water-based (>50% water in the carrier liquid system). The carrier liquid may further be a solvent selected from aliphatic, cycloaliphatic and aromatic hydrocarbons such as white spirit, cyclohexane, toluene, xylene and naptha solvent, esters such as methoxypropyl acetate, n-butyl acetate and 2-ethoxyethyl acetate; octamethyltrisiloxane, or other solvents used in solvent borne systems and mixtures thereof. Carrier liquids may also be other liquids used in paints, adhesives, sealants, caulks, and mineral and pigment slurries.
(12) In a preferred embodiment of this invention, the carrier liquid of a coatings composition is water or is water-based (>50% water in the carrier liquid system).
(13) Carrier liquids typically constitute 5-50% by volume of the paint or coating composition.
Binders, Other Additives, Pigments and Fillers
(14) Coatings compositions in accordance with the present invention may comprise for example, at least about 17% by weight, to about 55% by weight of binder polymer solids. Binders useful in latex paint compositions are known in the art and include polymeric binders, such as acrylics, vinyl acrylics, or styrene acrylics binders. Binders useful in solvent-borne paint/coating compositions are known in the art and include polymeric binders such as acrylic-amino, alkyd, polyurethane, epoxy, and a number of other natural or synthesized resins. In certain embodiments of the present invention, the copper glass nanoparticles and alkyldiol additives may be added to a coatings composition individually, together, or mixed into other components of the coatings composition at varying stages of the coatings composition formation.
(15) The inventive coatings composition may also include various other additives, including but not limited to thickeners, such as urethane thickeners, and acrylic thickeners in amounts up to about 10% by weight, for example about 1% to about 2%. Synthetic organic materials might also be incorporated; these include plastic beads, hollow spheres or other similar materials. Other optional components include glycols such as ethylene and/or propylene glycol in amounts up to about 7% and other solvents such as diethylene glycol dibenzoate and dipropylene glycol dibenzoate in amounts up to about 3%. The coating composition may also contain pigment dispersing agents which can be solvents or surfactants; additional wet paint preservatives; additional dry film preservatives; foam control agents such as oils, fatty acids and silicones; slip and mar additives; adhesion promoters, and/or other known paint additives. The paint composition of the present invention may also comprise further biocides or preservatives including but not limited to metal ion containing compounds, polymeric biocides, quaternary ammonium compounds, heterocyclic compounds, phenols, organometallics, aldehydes, proteins, peroxygens, alcohols, enzymes, polypeptides, and halogen releasing compounds.
(16) In one useful embodiment, the coating composition of the present invention is substantially free or totally free of amines.
(17) Exemplary coatings compositions of the present invention may further comprise at least about 5% and up to about 50% by weight pigments. Such pigments may comprise inorganic pigments, such as titanium dioxide. The paint composition comprises, for example, zero percent (for an ultradeep paint), at least about 11% by weight, further for example, at least about 12% by weight, further for example, at least about 13% by weight, further for example, at least about 14% by weight, further for example at least about 15% by weight, further for example, at least about 16%, further for example at least about 17%, further for example, at least about 18%, further for example at least about 19%, and even further for example at least about 20% up to about 30% by weight titanium dioxide. In another useful embodiment, the paint composition comprises more than 10% titanium dioxide. Other colored pigments or dyes may also be added to the paint, alone or in combination, to produce a wide range of colored paint. Suitable additional pigments may include calcium carbonate, talc, clay, silicates, aluminum silicates, calcium metasilicates, aluminum potassium silicates, magnesium silicates, barium sulfates, nepheline syenite, feldspar, zinc oxides or sulfides, or others known to those skilled in the art. Such additional colored pigments may be included in amounts up to about 30% by weight, for example, about 10% to about 20%. In some cases, “pigments” may also refer to functional fillers which are non-water soluble solids. Such functional fillers may include solids which provide additional functional characteristics to the paint, for example, intumescent ingredients, such as ammonium polyphosphates, melamines, pentaerythritol and similar compounds. In one useful embodiment, the coating composition of the present invention is substantially free or totally free of intumscent ingredients such as ammonium polyphosphates, melamines, and pentaerythritol and similar compounds.
(18) The pigment volume concentration, or PVC, of a coating is the ratio of the volume of pigments (including functional fillers) to the volume of total non-volatile material (i.e. pigment and binder) present in the coating. The coating of the present invention preferably has a PVC of about 5 to about 60. In addition, the coating composition of the present invention has a maximum solids content of less than 65% by weight, for example, about 25% by weight to about 60% by weight, further for example about 30% by weight to about 58% by weight.
Paint Composition
(19) In some useful embodiments, the copper glass nanoparticles constitute 1 g/gallon to 5 g/gallon of the coatings composition. In other useful embodiments, the copper glass nanoparticles constitute 1 g/gallon to 4 g/gallon of the coatings composition, in other embodiments 1.2 g/gallon to 3.8 g/gallon, in still others 2 g/gallon to 3.5 g/gallon, and in still others 2 to 3 g/gallon.
(20) In some useful embodiments, the alkyldiol additives, comprising a diol compound, are present in a coatings composition at 1000 to 7500 ppm by weight of the composition. In other useful embodiments, the alkyldiol additives are present at 2000 to 5000 ppm by weight, in other embodiments 2500 to 4500 ppm, and in still others 3000 to 4000 ppm.
(21) In certain useful embodiments, the present invention comprises a paint composition comprising water, latex binder resin, pigment, and additives, wherein such additives include, but are not limited to, copper glass nanoparticles and an alkyldiol additive or a blend of alkyldiol additives, and wherein the copper glass nanoparticles constitute 1 g/gallon to 4 g/gallon of the paint composition and the alkyldiol additive or blend of alkyldiol additives is present in the paint composition at 2000 to 5000 ppm by weight. In these embodiments, the coating composition is effectively preserved without issues of discoloration.
(22) It should be noted that in order to make a latex paint formulation, an appropriate dispersant/surfactant system is needed in order to disperse the pigments in the paint formulation. The process for selecting dispersants/surfactants for paint formulations is well known to those of ordinary skill in the paint formulation art. After selecting a compatible polymer and biocide package or microbially active composition comprised of copper glass nanoparticles and alkyldiol additive(s) as described herein, one of ordinary skill in the art would be able to select a dispersant/surfactant combination in order to make a desired paint composition.
EXAMPLES
Conventional Example 1 - Paint With Copper Glass Nanoparticles and No Traditional Biocides or Alkyldiol Additives
(23) For Conventional Example 1, a vinyl/acrylic base paint was prepared according to the amounts and components described below in TABLE 2 (“Conventional Base Paint 1”). The paint was prepared by mixing the following components using techniques known to those of ordinary skill in the art:
(24) TABLE-US-00002 Conventional Base Paint 1 Description Conventional Base Paint 1 Wt% Plasticizer.sup.1 0.9088 Proprietary Defoamer 0.9088 Rheological thickener.sup.2 1.454 Proprietary Vinyl/Acrylic Resin 1 24.5364 Proprietary Acrylic Resin 2 3.635 Rheological thickener.sup.3 0.4544 Dispersant.sup.4 0.4544 Water 32.3204 Nonionic Surfactant.sup.5 0.2726 Pigment.sup.6 0.159 Anti-settling agent.sup.7 0.3635 Pigment.sup.8 34.5327 1 Benzoflex B-50 from Eastman 2 Rheolate 350D from Elementis Specialties 3 Natrosol Plus 330 from Ashland 4 Tamol 731A from Dow Chemical 5 Triton X-102 from Dow Chemical 6 Soda Ash (Sodium Carbonate, Anhydrous) 7 MIN-U-GEL 400 Attapulgite Clay from Active Minerals International, LLC 8 Calcium Carbonate
(25) Guardiant™ copper glass nanoparticles were added to this composition to make three samples of 1 g/gallon, 5 g/gallon, and 10 g/gallon copper nanoparticle concentrations.
(26) Each sample of a differing concentration was then subjected to microbial challenge testing in which preservative efficacy was tested in a manner materially similar to the testing protocol detailed in ASTM D2574 - 16 Standard Test Method for Resistance of Emulsion Paints in the Container to Attack by Microorganisms (2016). The preservative testing used herein is described below. Discrepancies with ASTM D2574 are included in this description.
(27) Duplicate, 50 mL samples of each of the sample compositions having 1 g/gallon, 5 g/gallon, and 10 g/gallon copper nanoparticle concentrations were taken and each of the duplicate samples inoculated with: (Challenge 1) 5.0 mL of pooled culture at approximately 10.sup.9 CFU/mL on day 0 resulting in a final concentration of approximately 10.sup.8 CFU/mL within the sample; (Challenge 2) 2.5 mL of pooled culture at approximately 10.sup.9 CFU/mL on day 7 resulting in a final concentration of approximately 10.sup.8 CFU/mL within the sample; and (Challenge 3) 1.25 mL of pooled culture at approximately 10.sup.9 CFU/mL on day 14 resulting in a final concentration of approximately 10.sup.8 CFU/mL within the sample. Each sample was then incubated at 30° C. ± 2° C. For each sample, duplicate spread plates were made at 72 hours incubation and 7 days incubation from time of inoculation by spreading the sample evenly on an agar plate using aseptic techniques and incubating for 72 hours at 30° C. Challenge testing was also performed with respect to negative controls, which are agar plates with bacterial challenge, but no paint applied. Bacterial survival was quantified according to rating scale shown below in TABLE 3.
(28) TABLE-US-00003 Preservative Testing Rating Scale # Colonies CFU/mL (approx) Descriptive Rating Rating No growth <10.sup.2 Clean 1 1-5 1x10.sup.2 - 5x10.sup.2 Slight 2 6-10 6x10.sup.2 -1x10.sup.3 Slight 3 11-25 1.1x10.sup.3 - 2.5x10.sup.3 Slight/Moderate 4 26-50 2.6x10.sup.3 - 5x10.sup.3 Moderate 5 51-100 5.1x10.sup.3 - 1x10.sup.4 Moderate 6 101-200 1.1x10.sup.4 - 2x10.sup.4 Moderate/Severe 7 201-300 2.1x10.sup.4 - 3x10.sup.4 Severe 8 TNTC (rough edges) 3.1x10.sup.4 - 9x10.sup.5 Severe 9 TNTC (smooth edges) 1x10.sup.6 Severe 10
(29) Wherein “TNTC” = “Too Numerous to Count” and “CFU” = “Colony Forming Unit”
(30) The paint samples with copper glass nanoparticles and no other biocides or alkyldiol additives showed reliable preservative efficacy at 10 g/gallon concentration copper glass nanoparticles and unreliable preservative effect at lower concentrations, 1 g/gallon and 5 g/gallon, as shown below in TABLE 4.
(31) TABLE-US-00004 Preservative Testing Results for Conventional Example 1 Challenge 1 Challenge 2 Challenge 3 Cu Glass g/Gal Challenge 1 72 Hrs. 7 Days Challenge 2 72 Hrs. 7 Days Challenge 3 72 Hrs. 7 Days Sample Sample Sample Sample Sample Sample PLT 1 PLT 2 PLT 1 PLT 2 PLT 1 PLT 2 PLT 1 PLT 2 PLT 1 PLT 2 PLT 1 PLT 2 Negative Control A 0 10 10 10 10 10 10 10 10 10 10 10 10 Negative Control B 0 10 10 10 10 10 10 10 10 10 10 10 10 2A 1g/gal 3 1 2 1 9 9 1 1 9 9 4 4 2B 1g/gal 2 2 2 1 9 9 1 1 10 10 10 10 3A 5g/gal 2 1 1 1 2 1 1 1 2 1 1 1 3B 5g/gal 2 1 2 1 1 1 9 9 9 9 9 9 4A 10g/gal 1 1 2 1 1 1 1 1 2 1 1 1 4B 10g/gal 1 1 1 1 1 1 2 1 1 1 1 1
Base Paints 2 and 3
(32) In the following examples, base, comparative paint compositions were prepared according to the amounts and components described in TABLE 5. Two base, comparative paints (Acrylic Base Paint 2 and Acrylic Base Paint 3) were used. Each was prepared by mixing the following components using techniques known to those of ordinary skill in the art:
(33) TABLE-US-00005 Acrylic Base Paint Compositions Description Acrylic Base Paint 2 Wt% Acrylic Base Paint 3 Wt% Defoamer.sup.1 0.403 1.1092 Rheological thickener.sup.2 1.4508 0.3697 Acrylic Resin.sup.3 24.9859 42.0569 Opaque Polymer.sup.4 4.03 3.2351 Rheological thickener.sup.5 0 0.0508 Proprietary rheological thickener 0.0806 0 Dispersant.sup.6 0.6448 0 Water 15.5516 14.5075 Nonionic Surfactant.sup.7 0.0806 0 Pigment.sup.8 28.4114 14.683 Anti-settling agent.sup.9 0.4836 0.3696 Pigment.sup.10 23.5351 19.5957 Pigment.sup.11 0.0201 0.0293 Base.sup.12 0.0806 0.1849 Proprietary Surfactant Additives 0.2418 3.8082 1 Foamstar ST 2420 from BASF Formulation Additives 2 Rheolate 350D from Elementis Specialties 3 Formashield 12 from Dow Chemical 4 Ropaque Ultra EF from Dow Chemical 5 Natrosol Plus 330 from Ashland 6 Tamol 731A from Dow Chemical 7 Triton X-102 from Dow Chemical 8 Calcite, dry, ground; Sylosiv K300 Aluminosilicate from W.R. Grace; Opti-White P from Burgess; Minex 2 - Nepheline Syenite from Unimin; Calcium Carbonate, ground 9 Attagel Clay 40 from BASF 10 Titanium Dioxide Slurry 11 Red, yellow, blue pigments 12 Caustic Soda-25% (Sodium Hydroxide)
Conventional, Comparative Example 2 - Paint With Copper Glass but No Alkyldiol Additive
(34) To each of Acrylic Base Paints 2 and 3 identified above, Guardiant™ copper glass nanoparticles were added to make 5 g/gallon and 10 g/gallon concentration paints. Notably, even concentrations that showed questionable preservative efficacy (5 g/gallon) in Conventional Example 1 showed red, yellow, or orange discoloration in Conventional, Comparative Example 2 as a result of the high levels of copper glass added. Each sample of Acrylic Base Paints 2 and 3 (“Conventional, Comparative Example 2 Paints”) with added copper glass nanoparticles were shaded according to a standard shading procedure described below. If a paint cannot be shaded according to standard procedures to achieve a target masstone color, it will be difficult, costly or impossible to adequately color the paint for end user application. This is a significant impediment to paint’s decorative purpose.
(35) The Conventional, Comparative Example 2 Paints were shaded according to the following method. Two mil dry film thickness drawdowns of each of the Conventional, Comparative Example 2 Paints were taken on white Leneta charts. Masstone color was measured on a 45/0 spectrophotometer at D65 illuminant, 10 degree observer. Shade hit was walked in to match masstone color SW7006 Extra White, available from the Sherwin-Williams Company. No sample of the Conventional, Comparative Example 2 Paints could be shaded to within tolerance of 1.0 delta E (FMC2) from SW7006 Extra White.
Conventional, Comparative Example 3 - Paint With Alkyldiol Additives but No Copper Glass
(36) To Acrylic Base Paint 3, identified above, varying amounts of an alkyldiol (1,2-decanediol) were added in the grind phase of paint making to yield paints with the concentrations listed in TABLE 6, below (“Conventional, Comparative Example 3 Paints”). The Conventional, Comparative Example 3 Paints were further subjected to microbial challenge testing in which preservative efficacy was tested by the method described in Conventional Example 1. Instead of duplicate samples, triplicate, 50 mL samples of each of the Conventional, Comparative Example 3 Paints (with differing 1,2-decanediol concentrations) were taken and similarly inoculated. Challenge testing was also performed with respect to negative controls. Bacterial survival was again quantified according to rating scale shown above in TABLE 3.
(37) Conventional, Comparative Example 3 Paints showed moderate protection/preservation (failing challenge 3) even at high concentrations of alkyldiol.
(38) TABLE-US-00006 Preservative Testing Results for Comparative Example 3 1,2-decanediol Concentration Test Sample Challenge 1 Challenge 2 Challenge 3 72 Hours 7 Days 72 Hours 7 Days 72 Hours 7 Days Plate Plate Plate Plate Plate Plate 1 2 1 2 1 2 1 2 1 2 1 2 N/A Negative Control 10 10 10 10 10 10 10 10 10 10 10 10 2,500 PPM 1A 7 7 2 2 6 6 9 9 9 9 9 9 1B 7 7 2 2 6 6 9 9 9 9 9 9 1C 7 7 2 2 6 6 9 9 9 9 9 9 5,000 PPM 2A 2 1 2 1 9 9 10 10 9 9 9 9 2B 2 2 1 1 9 9 10 10 9 9 9 9 2C 2 2 1 1 9 9 10 10 9 9 9 9 10,000 PPM 3A 2 2 1 1 2 1 1 1 9 9 9 9 3B 1 2 1 1 1 1 1 1 9 9 9 9 3C 1 1 1 1 1 1 1 1 9 9 9 9 12,500 PPM 4A 2 2 1 1 1 1 1 1 9 9 9 9 4B 1 1 1 1 1 1 1 1 9 9 9 9 4C 1 1 1 1 1 1 1 1 9 9 9 9 15,000 PPM 5A 1 1 1 1 1 1 1 1 7 7 9 9 5B 1 1 1 1 1 1 2 1 7 7 9 9 5C 2 2 1 1 1 1 1 1 7 7 9 9
Inventive Example 1 With Copper Glass and Alkyldiol Additives
(39) The inventive examples were made by adding exemplary alkyldiol additives and copper glass nanoparticles to the same Acrylic Base Paints 2 and 3 described above (“Inventive Example 1 Paints”, with “Inventive Paints A and B” corresponding to Acrylic Base Paint 2, and “Inventive Paints C and D” corresponding to Acrylic Base Paint 3). Copper glass nanoparticles were added at 4 g/gallon. Inventive example paints contained the copper glass and an alkyldiol additive in the amounts shown below in TABLE 7.
(40) TABLE-US-00007 Inventive Paints A, B, C, and D Compositions Description Inventive Paint A Wt% Inventive Paint B Wt% Inventive Paint C Wt% Inventive Paint D Wt% Copper Glass Nanoparticles.sup.1 4 g/gallon 4 g/gallon 4 g/gallon 4 g/gallon Blend of 1,2-Hexanediol (50%) and 1,2-Octanediol (50%) 5000 ppm 0 5000 ppm 0 Blend of 1,2-Hexanediol, 1,2-Octanediol, and Methylbenzyl Alcohol 0 5000 ppm 0 5000 ppm 1 Guardiant™ Copper Glass Nanoparticles available from Corning, Inc.
(41) The Inventive Example 1 Paints, with smaller amounts of copper glass nanoparticles than the Conventional, Comparative Example 2 Paints, were all shadeable to SW7006 Extra White masstone color, from the Sherwin-Williams Company, using the method for shading described below.
(42) The Inventive Example 1 Paints were shaded according to the following method. Two mil dry film thickness drawdowns of each of the Inventive Example 1 Paints were taken on white Leneta charts. Masstone color was measured on a 45/0 spectrophotometer at D65 illuminant, 10 degree observer. Shade hit was walked in to match masstone color SW7006 Extra White. All samples of the Inventive Example 1 Paints could be shaded to within tolerance of 1.0 delta E (FMC2) from SW7006 Extra White.
(43) The Inventive Example 1 Paints were further subjected to microbial challenge testing in which preservative efficacy was tested by the method described in Conventional Example 1. Instead of duplicate samples, triplicate, 50 mL samples of each of the Inventive Example 1 Paints (Inventive Paints A, B, C, and D) were taken and similarly inoculated. Challenge testing was also performed with respect to negative control. Bacterial survival was again quantified according to rating scale shown above in TABLE 3.
(44) Challenge performance for Inventive Paints A and B and C and D are shown below in TABLES 8 and 9, respectively.
(45) TABLE-US-00008 Inventive Paints A and B Test Sample Challenge 1 Challenge 2 Challenge 3 72 Hours 7 Days 72 Hours 7 Days 72 Hours 7 Days Plate Plate Plate Plate Plate Plate 1 2 1 2 1 2 1 2 1 2 1 2 Negative Control 10 10 10 10 10 10 10 10 10 10 10 10 A1 1 1 2 1 2 1 1 1 1 1 1 1 A2 1 1 3 1 1 1 1 1 1 1 1 1 A3 1 1 1 1 1 1 1 1 1 1 1 1 B1 2 1 1 1 2 1 2 2 1 1 1 1 B2 1 1 1 1 2 1 1 1 1 1 1 2 B3 1 1 1 1 1 1 1 1 1 1 1 1
(46) TABLE-US-00009 Inventive Paints C and D Test Sample Challenge 1 Challenge 2 Challenge 3 72 Hours 7 Days 72 Hours 7 Days 72 Hours 7 Days Plate Plate Plate Plate Plate Plate 1 2 1 2 1 2 1 2 1 2 1 2 Negative Control 10 10 10 10 10 10 10 10 10 10 10 10 C1 2 1 1 2 2 3 2 1 2 1 1 1 C2 2 1 1 2 2 3 1 1 1 1 1 1 C3 2 2 1 2 3 3 1 1 1 1 1 1 D1 2 1 1 1 2 3 1 1 1 1 1 1 D2 1 1 1 1 2 3 1 1 9 9 9 9 D3 2 2 1 1 3 3 1 1 2 2 1 1