Microbial resistant roof coating and system

Abstract

A roofing and/or siding material that reduces the incidence of undesired micro-organisms from entering into the air intake of air conditioner and/or heating systems of a building structure to thereby improve the quality of the air in the building structure.

Claims

1. A coating material that inhibits the growth of microbials on a surface of said coating material, said coating material includes water, a base coat composition, an anti-microbial additive and one or more additives selected from the group consisting of acrylic resin, pH indicator, surfactant, deairator, solvent, defoamer, thickener, filler, pH adjuster, and pigment, said base coat composition includes a resin material, said coating material includes by weight percent: TABLE-US-00006 Water 20-40 Acrylic resin 60-75 Anti-microbial additive 0.1-10 Defoamer 0.05-0.8 pH adjuster 0-0.5 pH indicator 0-1 Solvent 0.05-2 Surfactant 0.05-1.

2. The coating material as defined in claim 1, wherein said anti-microbial additive includes two different anti-microbial compounds.

3. The coating material as defined in claim 1, wherein said coating material includes by weight percent: TABLE-US-00007 Water 28-30 Acrylic resin 65-70 Anti-microbial additive 0.4-1.5 Defoamer 0.2-0.6 pH adjuster 0-0.3 pH indicator 0-0.3 Solvent 0.5-0.9 Surfactant 0.5-0.9.

4. The coating material as defined in claim 2, wherein said coating material includes by weight percent: TABLE-US-00008 Water 28-30 Acrylic resin 65-70 Anti-microbial additive 0.4-1.5 Defoamer 0.2-0.6 pH adjuster 0-0.3 pH indicator 0-0.3 Solvent 0.5-0.9 Surfactant 0.5-0.9.

5. The coating material as defined in claim 1, wherein said anti-microbial additive is 0.1-6 wt %, said solvent is 0.2-2 wt. %, said coating material further including 0.05-1 wt. % deairator.

6. The coating material as defined in claim 2, wherein said anti-microbial additive is 0.1-6 wt %, said solvent is 0.2-2 wt. %, said coating material further including 0.05-1 wt. % deairator.

7. The coating material as defined in claim 1, wherein said water is 25-30 wt. %, said acrylic resin is 66-72 wt. %, said anti-microbial additive is 0.4-1.2 wt. %, said solvent is 0.5-1 wt. %, said surfactant is 0.4-0.8 wt. %, said coating material further includes 0.1-0.3 wt. % deairator.

8. The coating material as defined in claim 2, wherein said water is 25-30 wt. %, said acrylic resin is 66-72 wt. %, said anti-microbial additive is 0.4-1.2 wt. %, said solvent is 0.5-1 wt. %, said surfactant is 0.4-0.8 wt. %, said coating material further includes 0.1-0.3 wt. % deairator.

9. The coating material as defined in claim 1, wherein said filler is 5-60 wt. %, said pH adjuster is 0.01-0.5 wt. %, said pH indicator is 0.01-0.5 wt. % said pigment is 1-15 wt. %, said solvent is 0.05-1 wt. %, and said thickener is 0.05-2 wt. %.

10. The coating material as defined in claim 2, wherein said filler is 5-60 wt. %, said pH adjuster is 0.01-0.5 wt. %, said pH indicator is 0.01-0.5 wt. %, said pigment is 1-15 wt. %, said solvent is 0.05-1 wt. %, and said thickener is 0.05-2 wt. %.

11. The coating material as defined in claim 1, wherein said anti-microbial additive is 0.2-1 wt. %, said filler is 20-40 wt. %, said pH adjuster is 0.01-0.5 wt. %, said pH indicator is 0.05-0.1 wt. %, said pigment is 4-10 wt. %, said solvent is 0.4-0.9 wt. %, said surfactant is 0.2-0.6 wt. %, and said thickener is 0.2-0.8 wt. %.

12. The coating material as defined in claim 2, wherein said anti-microbial additive is 0.2-1 wt. %, said filler is 20-40 wt. %, said pH adjuster is 0.01-0.5 wt. %, said pH indicator is 0.05-0.1 wt. %, said pigment is 4-10 wt. %, said solvent is 0.4-0.9 wt. %, said surfactant is 0.2-0.6 wt. %, and said thickener is 0.2-0.8 wt. %.

13. The coating material as defined in claim 1, wherein said anti-microbial additive is 0.4-2.5 wt. %, said defoamer is 0.05-0.4 wt. %, said solvent is 0.4-0.9 wt. %, said surfactant is 0.2-0.8 wt. %, said coating further including 0.1-0.5 wt. % deairator.

14. The coating material as defined in claim 2, wherein said anti-microbial additive is 0.4-2.5 wt. %, said defoamer is 0.05-0.4 wt. %, said solvent is 0.4-0.9 wt. %, said surfactant is 0.2-0.8 wt. %, said coating further including 0.1-0.5 wt. % deairator.

15. The coating material as defined in claim 1, wherein said resin includes a water-based acrylic resin with a glass transition temperature of about 0 F. to 90 F.

16. The coating material as defined in claim 1, wherein said anti-microbial additive includes one or more materials selected from the group consisting of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one; sodium copper ethylenediaminetetraacetate; methyl 2-benzimidazolecarbamate (BCM); 3-iodo-2-propynyl butyl carbamate (IPBC); 3-(3,4-dichlorophenyl)-1, 1-dimethylurea; 1,3-dihydroxymethyl-5,5-dimethylhydantoin; 1-hydroxymethyl-5,5-dimethylhydantoin; cyclopropyl-N-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine; octylisothiazolone; and quaternary ammonium compound.

17. The coating material as defined in claim 1, wherein said surfactant is 0.05-1 wt. %, said surfactant including one or more compounds selected from the group consisting of ethoxylated nonionic surfactant; benzyl-polyethylene glycol (1,1,3,3-tetramethylbutylphenyl) ether, and benzyl-polyethylene glycol tert-octylphenyl ether.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Reference may now be made to the drawings which illustrate various non-limiting embodiments that the invention may take in physical form and in certain parts and arrangement of parts wherein:

(2) FIG. 1 is a graph illustrating bacterial growth on treated and untreated surfaces; and,

(3) FIG. 2 is a graph illustrating fungal growth on treated and untreated surfaces.

DETAILED DESCRIPTION OF THE NON-LIMITING EMBODIMENTS

(4) Referring now to the drawings, wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting same, the present invention is directed to a roofing and/or siding system or other building structure (e.g., plaza decks, exterior and interior walls, floors, sidewalks, patios, decks, stairs, steps, porches, etc.) that includes a coating material that is formulated to resist or inhibit microbial growth (e.g., bacteria, fungus, etc.) and method for forming such roofing and/or siding system and method for maintaining the efficacy of the roofing and/or siding system to resist or inhibit microbial growth. The inclusion of one or more agents that inhibit or prevent microbial growth can be used to prevent or inhibit the growth of fungus, mold, mildew and/or other types of undesirable micro-organisms on the roofing and/or siding material or other building structures, thereby reducing the incidence of undesired micro-organisms from contacting individuals and/or from being drawn into the air intake of air conditioner and/or heating units on the roof or other locations of a building. As such, the present invention is particularly directed to a roofing and/or siding system that can improve the air quality for individuals located inside a building structure without the need for expensive and complex air filtration systems.

(5) The one or more agents that inhibit or prevent microbial growth are typically coated on all or a portion of the outer surface of the roofing and/or siding material or other building structures. The coating can be applied after the roofing and/or siding material has been preformed, and/or during and/or after the roofing and/or siding material has been applied to a building structure. The coating can be designed to be spray coated, painted, mop-applied, and the like. The coating can be a clear coating or include a color pigment to form a colored coating.

(6) The coating material that includes one or more agents that inhibit or prevent microbial growth can be coated on a variety of substrates that include, but are not limited to, mineral cap sheet, flood coated rock, aluminum, Galvalume, galvanized, Kynar, steel, EPDM, PVC, TPO, coal tar mineral, white reflective elastomeric coating, and white reflective polyurethane coating.

(7) The coating material includes a base coat composition and one or more anti-microbial additives. The base coat composition can include one or more resins. The one or more resins can include, but are not limited to, resins of acrylate, resins of latex, vinyl, styrene, vinyl acetate, ester and/or urethane polymers. In one non-limiting embodiment of the invention, the resin includes a water-based acrylic resin with a glass transition temperature (T.sub.g) of about 5 F. to 20 F., typically about 0 F. to 10 F., and more typically about 3 F. to 7 F. One non-limiting resin that can be used is an acrylic latex resin (e.g., Rhoplex EI-6000 from Dow Chemical, etc.). Other resins that can be used include, but are not limited to, Elastine 8556, Lipacryl MB3640, Primal 8349, Primal AC-3001, Primal AS-8000, Primal EC-1791, Primal MC-76LO, Primal WL8179, UCAR 161N, UCAR CM 101; RHOPLEX EI-2000 and RHOPLEX EI-5000. The one or more anti-microbial additives can include, but are not limited to, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, sodium copper ethylenediaminetetraacetate, methyl 2-benzimidazolecarbamate (BCM); 3-Iodo-2propynyl butyl carbamate (IPBC); 3-(3,4-dichlorphenyl)-1,1-dimethylurea; 1,3-dihydroxymethyl-5,5-dimethylhydantoin; 1-hydroxymethyl-5,5-dimethylhydantoin; methyl 2-benzimidazolecarbamate; 3-Iodo-2-propynyl butyl carbamate; diuron[3-(3,4-dichlorphenyl)-1,1-dimethylurea); Cyclopropyl-N-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine; octylisothiazolone; and quaternary ammonium compound. Non-limiting examples of commercially available anti-microbial additives that can be used include Bioban 200 and Rozone 2000 (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one and sodium copper ethylenediaminetetraacetate), Polyphase 662 (Methyl 2-benzimidazolecarbamate, 3-Iodo-2-propynyl butyl carbamate and cyclopropyl-N-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine); Polyphase 663 (Methyl 2-benzimidazolecarbamate, 3-Iodo-2-propynyl butyl carbamate and Diuron[3-(3,4-dichlorphenyl)-1,1-dimethylurea)); Troysan 395 (1,3-dihydroxymethyl-5,5-dimethylhydantoin and 1-hydroxymethyl-5,5-dimethylhydantoin); Bioban 100 (octylisothiazolone; and quaternary ammonium compound). The one or more anti-microbial additives can also or alternatively include one or more naturally occurring and/or synthetic proteins, polypeptides and/or peptides as a means to inhibit fungal and bacterial growth. Such naturally occurring and/or synthetic proteins, polypeptides and/or peptides can be used to target specific fungal species or bacterial species that are present roof and/or siding surfaces; however, this is not required. Other non-limiting examples of anti-microbial additives that can also or alternative be used, are disclosed in U.S. Pat. No. 8,106,111; U.S. Pat. No. 7,939,500; U.S. Pat. No. 7,932,230; U.S. Pat. No. 7,736,423; US 2005/0058689; US 2006/0141003; US 2012/0097194; EP 0355765 and EP 2431429, all of which are incorporated herein by reference. The coating material can also optionally include a coloring agent that becomes clear or substantially clear once the coating dries and/or cures. The coloring agent can also be formulated to cause the dried and/or cured coating to be glossy and/or semi-glossy; however, this is not required. Non-limiting examples of such a color agent includes, but is not limited to, a pH indicator (e.g., phenol red, phenolphthalein, thiolphthalein, etc.). The coating material can include one or more dispersants or surfactants, coalescing solvent, defoamers, and/or deairators. Non-limiting surfactants that can be used include ethoxylated nonionic surfactant (e.g., Carbowet 106 (air products), Carbowet 109 (air products), Carbowet 125 (air products), Carbowet 138 (air products), etc.); benzyl-polyethylene glycol (1,1,3,3-tetramethylbutylphenyl) ether, benzyl-polyethylene glycol tert-octylphenyl ether (e.g., Triton CF-10 (Dow Chemical), etc.). The coating material can include one or more defoamers. Non-limiting defoamers include 3-dimensional siloxane (e.g., DEEFO PI-35 (Munzing), DEEFO PI50 (Munzing), etc.); emulsion of polyether-siloxane (e.g., Tego Airex 902W (Evonik), etc.). The coating material can include one or more coalescing solvents (e.g., non-water solvents). Non-limiting coalescing solvents include ester alcohol (e.g., Texanol (Eastman Chemical), etc.). The coating material can include one or more deairators. Non-limiting coalescing deairators include siloxane deairator (e.g., Airase 8070 (Air Products), etc.). The coating material can include one or more additional materials such as pH indicators, fillers, color pigments (e.g., titanium dioxide, etc.) and the like.

(8) One general formulation of the coating is as follows:

(9) TABLE-US-00001 Raw Material Weight % Range Water 10-40 Resin 20-75 Anti-microbial Additive 0.01-10.sup. pH Indicator 0-1 Dispersant or surfactant 0-2 Defoamer 0-2 pH adjuster (e.g., ammonia) 0-1 Coalescent or solvent 0-2 Color Agent or pigment 0-25 Filler 0-70 Deairator 0-1 Thickener 0-3

(10) One non-limiting clear coating formulation is as follows:

(11) TABLE-US-00002 Weight Example A Raw Material % Range Weight % Water 20-40 29.4 High Tg Acrylic (e.g., Dow's EI-6100, etc.) 60-75 68.7 Anti-microbial Additive Blend 0.1-10 0.8 (e.g., Troysan 395 and of either Polyphase 663 or Polyphase 662, etc.) pH Indicator 0-1 0.2 Dispersant or sufactant (e.g., Air Product's 0.1-1.sup. 0.6 Carbowet 109 or Dow's Triton CF-10, etc.) Defoamer (e.g., DEEFO PI-35 or the like 0.05-0.8 0.4 from Ultra Additives, Tego Airex 902W from Evonik) pH adjuster (e.g., ammonia, etc.) .sup.0-0.5 0.2 Coalescent or solvent (e.g., Texanol, etc.) 0.1-1.sup. 0.7

(12) Another non-limiting clear coating formulation is as follows:

(13) TABLE-US-00003 Weight Example B Raw Material % Range Weight % Water 20-40 28.7% Acrylic Latex (e.g., Rhoplex EI-6000, etc.) 60-75 69.0% Surfactant (e.g., Carbowet 109, etc.) 0.1-1 0.6% Siloxane Deairator (e.g., Airase 8070, etc.) 0.05-1.sup. 0.2% Coalescing Solvent (e.g., Texanol, etc.) 0.2-2 0.7% In-Can Bactricide (e.g., Troysan 395, etc.) 0.05-1% 0.2% Dry Film Anti-microbial/Antifungal Additive 0.05-4% 0.6% (e.g., Bioban 200, etc.)

(14) One non-limiting non-clear coating formulation is as follows:

(15) TABLE-US-00004 Example C Raw Material Weight % Weight % Water 10-25 13.7 Associative Thickener 0.05-2 0.5 Anti-microbial Additive Blend 0.05-3 0.2-1 (e.g., Troysan 395 and Bioban 200 or Rozone 2000, etc.) pH Indicator 0.01-0.5 0.05-0.1 Dispersant or surfactant(Air Product's 0.05-1 0.4 Carbowet 109 or Dow's Triton CF-10) Defoamers (DEEFO PI-35 or the like from 0.05-0.8 0.3 Ultra Additives, Tego Airex 902W from Evonik) pH adjuster (e.g., ammonia, etc.) 0.01-0.5 0.1 Coalescent or solvent (Texanol) 0.05-1 0.7 Titanium Dioxide 1-15 6.3 Acrylic Latex 20-55 42 Filler 5-60 34

(16) One non-limiting method for applying a coating material (e.g., clear coating, non-clear coating) to a roofing and/or siding material that inhibits or prevents microbial growth on the roofing and/or siding material comprising the steps of:

(17) a. Cleaning the surface of the roofing and/or siding material which is installed on a building structure, wherein the washing process can optionally including a power washing process with a detergent (e.g., Simple Green), diluted bleach solution, etc., and then optionally a rinsing cleaning;

(18) b. Optionally applying one or more coatings of a bio-resistant base coat composition to the roofing and/or siding material (e.g., spray coating, brush coating, etc.);

(19) c. Applying one or more coatings of a bio-resistant clear or non-clear coating (e.g., spray coating, brush coating, etc.) that would retain its anti-microbial properties for a period of 3-36 months and typically about 12-24 months; and,

(20) d. Optionally applying a new a coating of a bio-resistant clear or non-clear coating after a certain period of time has passed (e.g. 3-36 months) since applying a previous coating of a bio-resistant clear or non-clear coating so as to maintain the efficacy of the coating on the roofing and/or siding material.

(21) The effectiveness of the coating composition to inhibit or prevent bacterial and fungal growth on a treated rood surface is set forth below. Two formulations of the coated were tested. The two formulations are set forth as follows:

(22) TABLE-US-00005 Example 1 Example 2 Raw Material Example of Raw Material wt % wt % Water 29.2% 28.8% Acrylic Latex Rhoplex EI-6000 68.4% 67.4% Surfactant Carbowet 109 0.6% 0.6% Siloxane Deairator Airase 8070 0.2% 0.2% Coalescing Solvent Texanol 0.7% 0.7% Defoamer DEEFO PI-35 0.1% 0.1% Bactricide Troysan 395 0.2% 0.2% Dry Film Anti- Polyphase 662 0.6% 2.0% microbial/ Antifungal Additive

(23) The non-limiting test procedure, which test results are illustrated in FIGS. 1 and 2, is described as follows:

(24) Two sets of 36 panels that included two types of typical (but non-limiting) roof surfaces were used in the experiment, namely a modified bitumen mineral-based cap sheet and a flood coat and graveled (FC/G) system consisting. Each panel included about 6-8 gal/100 ft.sup.2 of asphalt or modified asphalt over a non-mineral (or smooth) base sheet. Immediately after applying the hot asphalt or modified asphalt to the base sheet, aggregate in the form of pea gravel or river rock was dropped onto the still-molten asphalt surface. Five specimens of each representative surface type were left untreated (marked Control), two additional sets of five specimens from each surface type were coated on both sides with the coating formulations of Example 1 and Example 2. The panels were randomly arranged on stackable trays, which were then placed into a large bin containing enough water to be within approximately from the bottom of the bottom tray. To encourage growth, an inocula solution was produced using several fungi and bacteria isolated from submitted actual roof specimens. The bin was sealed (not airtight) with a lid and placed under lamps that maintained the bin's daily interior temperature at between 95-100 F. Specimens were also sprayed with a solution of potato water and sugar to encourage fungal growth as well as a solution of salt-free chicken broth to encourage bacterial growth.

(25) Small cuts (approx. 11) were taken from each specimen at monthly intervals beginning at one month and continuing to six months. Testing of these specimens consisted of standard dilution of each followed by spread plating on a tryticase soy agar (TSA) to enumerate bacteria and a sabouraud dextrose agar (SDA) to enumerate fungal and mildew growth. The TSA was allowed to incubate 1-3 days at 86-95 F., and the SDA was allowed to incubate 2-5 days at 68-77 F. FIGS. 1 and 2 illustrate the averages of colony forming units (CFU) per gram of sample tested.

(26) Referring to FIG. 1, there is a 20-30% reduction in bacteria colonies over mineral cap sheet and a more pronounced 57-87% reduction in bacterial colonies over flood coat and the gravel system when treated with the coating compositions of Examples 1 and 2. As illustrated in FIG. 2, there is an 80-97% reduction in fungal colonies formed over mineral cap sheet and a 55-99% reduction in fungal colonies over flood coat and gravel sheets treated with the coating compositions of Examples 1 and 2. FIGS. 1 and 2 graphically illustrate that the coating compositions of Examples 1 and 2 significantly reduce the growth of bacteria and fungi on roof systems as compared to a non-treated roof system.

(27) It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. The invention has been described with reference to preferred and alternate embodiments. Modifications and alterations will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. This invention is intended to include all such modifications and alterations insofar as they come within the scope of the present invention. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.