阅读说明：本技术 包含硅灰石的抗微生物组合物 (Antimicrobial compositions containing wollastonite ) 是由 J·施米茨 L·维尔斯图福特 J·博拉德 于 2019-10-04 设计创作，主要内容包括：本发明涉及包含硅灰石作为抗微生物剂增强剂的抗微生物组合物及其用途。本发明还涉及包含所述抗微生物组合物的油漆或涂料组合物以及用根据本发明的抗微生物组合物处理过的制品。(The present invention relates to antimicrobial compositions comprising wollastonite as an antimicrobial agent enhancer and uses thereof. The invention also relates to a paint or coating composition comprising said antimicrobial composition and to an article treated with the antimicrobial composition according to the invention.)

1. An antimicrobial composition comprising an antimicrobial agent and wollastonite as an enhancer for the antimicrobial agent.

2. The antimicrobial composition of claim 1, wherein the wollastonite is untreated.

3. The antimicrobial composition of claim 1 or claim 2, wherein the wollastonite has a median particle diameter d₅₀Is 5 to 120 microns, and/or wherein the wollastonite has a BET surface area of 0.2m²G to 5.0m²/g。

4. The antimicrobial composition of any of the preceding claims, wherein the wollastonite is present in an amount of 2.5 to 37.5 weight percent based on the weight of the composition.

5. An antimicrobial composition according to any one of the preceding claims, wherein the antimicrobial agent inhibits, stops and/or kills microbial growth.

6. An antimicrobial composition according to claim 5, wherein the microorganism is selected from bacteria, archaea, fungi, protozoa, algae and/or viruses.

7. An antimicrobial composition according to any one of the preceding claims, wherein the antimicrobial agent comprises a synthetic biocide and/or a synthetic fungicide.

8. The antimicrobial composition according to any one of the preceding claims, comprising the synthetic biocide and/or synthetic fungicide in an amount of up to 0.10 wt. -%, based on the total weight of the composition, preferably in an amount of from 0.001 wt. -% to 0.1 wt. -%, based on the total weight of the composition, for example in an amount of from 0.001 wt. -% to 0.02 wt. -%, based on the total weight of the composition, for example in an amount of from 0.001 wt. -% to 0.01 wt. -%, based on the total weight of the composition.

9. The antimicrobial composition of any one of the preceding claims, further comprising one or more of a resin, a dispersant, a coalescing agent, a defoamer, a filler, an extender, a thickener, and/or a neutralizing agent.

10. The antimicrobial composition of any one of the preceding claims, further comprising a pigment, such as titanium dioxide.

11. The antimicrobial composition of any one of the preceding claims, comprising:

-from 0.001% to 0.01% of an antimicrobial agent, preferably from 0.001% to 0.02%, or from 0.001% to 0.01%, based on the total weight of the coating composition; and

-wollastonite as biocide enhancing agent in an amount of 2.5% to 37.5% based on the total weight of the coating composition.

12. The antimicrobial composition of claim 11, further comprising talc.

13. The antimicrobial composition of claim 12, comprising from 2.5% to 37.5% talc.

14. An antimicrobial composition according to any one of claims 11 to 13, wherein the pH of the composition is below 10, preferably below 9.5.

15. An antimicrobial composition according to any one of claims 11 to 14, wherein the antimicrobial agent is selected from the list of: 1, 2-Benzisothiazol-3 (2H) -one (BIT), a mixture of 5-chloro-2-methyl-2H-isothiazol-3-one and 2-methyl-2H-isothiazol-3-one (CMIT/MIT), 4, 5-dichloro-2-octyl-2H-isothiazol-3-one (DCOIT), 2-methyl-2H-isothiazol-3-one (MIT), 2-octyl-2H-isothiazol-3-one (DBOIT), dibromopropionamide (NPA), glutaraldehyde, 3-iodo-2-propynyl butylcarbamate (IPBC), dimethomon, 2-methyl-1, 2-benzothiazol-3 (2H) -one (MBIT), Benzamide, 2' -dithiobis (N-methyl) (DTBMA), tetramethylol-acetylene diurea (TMAD), ethylene glycol bis-hemiformal (EDDM), 2-bromo-2- (bromomethyl) glutaronitrile (DBDCB), permethrin, propiconazole (DMI), chlorocresol (PCMC), bronopol, Thiabendazole (TBZ), 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea (DCMU; diuron), 2-benzyl-4-chlorophenol, fenoxycarb, tebuconazole, isoproturon, cyproconazole, fludioxonil, pyrimethanil, zinc pyrithione, carbendazim, and thiamethoxam.

16. A paint or coating composition comprising the antimicrobial composition of any one of claims 1 to 15.

17. A paint or coating composition consisting of the antimicrobial composition of any one of claims 1 to 15.

18. The paint or coating composition comprising an antimicrobial composition according to claim 16 or claim 17, wherein the synthetic biocide and/or synthetic fungicide is present in an amount of up to 0.10% by weight based on the weight of the composition.

19. Use of the antimicrobial composition of any one of claims 1 to 15 for preventing the growth of microorganisms in a liquid and/or on an object.

20. Use of wollastonite as an antimicrobial enhancing agent.

21. Use of a blend of talc and wollastonite as an antimicrobial enhancing agent.

22. A method of preventing microbial growth in a liquid and/or on an object by applying the composition of any one of claims 1 to 18 to the liquid and/or the object.

23. An article treated with the antimicrobial composition of claims 1 to 18.

Technical Field

The present invention relates to antimicrobial compositions comprising wollastonite as an antimicrobial agent enhancer and uses thereof. The invention also relates to paint or coating compositions comprising the antimicrobial composition of the invention and articles treated with the antimicrobial composition of the invention.

Background

Microbial growth in paints, coatings and on surfaces can lead to aesthetic and physical degradation of the coating or coated surface. In addition to the obvious aesthetic effects of fungal ((e.g., mildew and mildew), algae, and bacterial growth), their enzyme-induced physical damage can also lead to physical degradation.

There are a number of challenges faced when selecting an antimicrobial agent for use in an antimicrobial composition. One of the challenges is that there are relatively few biocides, fungicides, and algicides available at present. Such actives are needed to meet a range of requirements. In addition to covering a broad spectrum of microorganisms, the regulatory status of the active agents should also be considered. Accordingly, it is desirable to reduce the amount of antimicrobial agents used in antimicrobial compositions such as paints and coatings.

Disclosure of Invention

The invention is defined in the appended claims.

According to a first aspect, an antimicrobial composition comprising wollastonite as an antimicrobial agent enhancer is provided.

According to a second aspect, there is provided a paint or coating composition comprising an antimicrobial composition according to the first aspect.

According to a third aspect, there is provided the use of an antimicrobial composition according to the first aspect for preventing the growth of microorganisms in a liquid and/or on an object.

According to a fourth aspect, there is provided a method of preventing microbial growth in a liquid and/or on an object by applying the composition of the first aspect to the liquid and/or the object.

According to a fifth aspect, there is provided an article treated with the antimicrobial composition of the first aspect.

Certain embodiments of the invention may provide one or more of the following advantages:

the desired antibacterial effect;

the desired antifungal effect;

the desired anti-algal effect;

desired environmental impact;

the desired effect on skin sensitivity;

the expected cost;

the desired aesthetic properties of the paint, such as opacity;

desired aesthetic properties of the paint, such as gloss;

desired aesthetic properties of the paint, such as brightness;

the desired physical properties of the coating, such as hardness;

desired physical properties of the coating, such as scrub resistance;

desired physical properties of the coating, e.g. resistance to cracking

The details, examples and preferences provided in connection with any particular one or more of the described aspects of the invention are equally applicable to all aspects of the invention. Any combination of the embodiments, examples and preferred embodiments described herein, in all possible variations thereof, is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Drawings

The invention will be further explained with reference to the following figures:

figure 1 shows the antifungal properties of the compositions according to the invention and describes the results shown in table 10:

a) formulation 9;

b) a formula 10; and

c) formulation 11.

Figure 2 shows the anti-algal properties of the composition according to the invention and describes the results shown in table 11:

a) formulation 9;

b) a formula 10; and

c) formulation 11.

It should be understood that the following description and references to the accompanying drawings relate to exemplary embodiments of the present invention and should not limit the scope of the claims.

Detailed Description

The present invention is based on the surprising finding that wollastonite exhibits an enhancing effect on the antimicrobial activity of an antimicrobial agent. Wollastonite is an industrial mineral that chemically consists of calcium, silicon and oxygen. The molecular formula is CaSiO₃The theoretical composition of the catalyst comprises 48.28 percent of CaO and 51.72 percent of SiO₂And (4) forming. Natural wollastonite may contain trace or small amounts of various metal ions such as aluminum, iron, magnesium, potassium, and sodium.

In certain embodiments, the wollastonite is untreated, meaning that the wollastonite is not coated or bonded with any material or chemical prior to use in the composition. In certain embodiments, wollastonite is mined and ground and used directly in the compositions of the present invention. In certain embodiments, after beneficiation, the wollastonite is treated by an air classification mill, followed by a pebble mill or jet mill, while controlling the maximum size.

The wollastonite disclosed herein has a particle size. Particle size may be measured by any suitable measurement technique now known or later discovered by those skilled in the art. Unless otherwise indicated, particle size and particle size properties, such as particle size distribution ("psd"), can be determined using a Leeds and North Microtrac X100 laser particle size analyzer (Leeds and North Wales, Pennsylvania, USA). The size of a given particle is expressed in terms of the diameter of a sphere of equivalent diameter, also called the sphere of equivalent diameter, precipitated by a suspensionDiameter or "esd". Median particle diameter or d₅₀The esd of the particles having a value of 50% by weight is less than d₅₀The value of the value. d₁₀The esd of the particles having a value of 10% by weight is less than d₁₀The value of the value. d₉₀The esd of the particles having a value of 90% by weight is less than d₉₀The value of the value.

In certain embodiments, the wollastonite has an average particle size d₅₀From about 5 microns to about 120 microns, or from about 6 microns to about 100 microns, or from about 7 microns to about 80 microns, or from about 9 microns to about 60 microns, or from about 10 microns to about 40 microns, or from about 11 microns to about 20 microns, or from about 12 microns to about 18 microns, or from about 13 microns to about 16 microns.

The surface area of the mineral is measured using the BET method (measured according to BET method, AFNOR standards X11-621 and 622 or ISO 9277) by the amount of nitrogen adsorbed on the surface of the particles to form a monolayer completely covering the surface.

In certain embodiments, the BET surface area is about 0.2m²G to about 5.0m²In g, or about 0.4m²G to about 4.8m²In g, or about 0.6m²G to about 4.6m²In g, or about 0.8m²G to about 4.4m²In g, or about 0.6m²G to about 4.2m²In g, or about 1.0m²G to about 4.0m²In g, or about 1.2m²G to about 3.8m²In g, or about 1.4m²G to about 3.6m²In g, or about 1.6m²G to about 3.0m²In g, or about 1.7m²G to about 2.7m²In g, or about 1.8m²G to about 2.5m²In g, or about 1.9m²G to about 2.2m²/g。

According to certain embodiments, the morphology of wollastonite may be characterized by a length to diameter ratio. The aspect ratio of the particles is generally referred to as the aspect ratio of the particles. For a given sample of particles, the aspect ratio can be determined as an average. For example, the aspect ratio of wollastonite particles according to certain embodiments may be determined by first depositing a slurry of a sample comprising wollastonite particles at a standard SEM stage and coating the slurry with platinum. Thereafter an image of the slurry can be taken and the particle size can be determined, for example using computer-based analysis, wherein the thickness and width of the particles are assumed to be equal. The aspect ratio may then be determined by averaging the calculated values (e.g., fifty calculations) for the length to width aspect ratio of each particle. Other methods of determining aspect ratio may be considered.

In certain embodiments, the wollastonite particles may have an aspect ratio of at least 2: 1. For example, the wollastonite particles may have an aspect ratio of at least 3:1, an aspect ratio of at least 4:1, an aspect ratio of at least 7:1, an aspect ratio of at least 12:1, an aspect ratio of at least 15:1, or an aspect ratio of at least 20: 1.

In certain embodiments of the method, the wollastonite particles may have a median plate thickness of less than or equal to about 2 microns, such as, for example, less than or equal to about 1 micron. According to certain embodiments, the wollastonite may have a median plate thickness of from about 3 microns to about 60 microns, or from about 4 microns to about 50 microns, or from about 5 microns to about 40 microns, or from about 6 microns to about 30 microns, or from about 7 microns to about 20 microns, or from about 8 microns to about 15 microns, or from about 9 microns to about 12 microns.

In certain embodiments, the wollastonite is present in the antimicrobial composition in an amount of about 2.5% to about 37.5% by weight, or about 5.0% to about 35.0% by weight, or about 7.5% to about 32.5% by weight, or about 10.0% to about 30.0% by weight, or about 12.5% to about 27.5% by weight, or about 15.0% to about 25.0% by weight, or about 17.5% to about 22.5% by weight, or about 18.0% to about 20.0% by weight, based on the total weight of the composition.

The antimicrobial agent according to the present invention may have the effect of inhibiting the growth of microorganisms, stopping the growth of microorganisms and/or killing microorganisms. Antimicrobial agents according to the present invention may include synthetic biocides and synthetic fungicides. The microorganism is for example selected from bacteria, archaea, fungi, protozoa, algae and/or viruses. In certain embodiments, when the combination of the antimicrobial agent of the present invention and wollastonite is used, the growth of microorganisms is reduced by up to about 10%, up to about 20%, up to about 30%, up to about 40%, up to about 50%, up to about 60%, up to about 70%, up to about 80%, up to about 85%, up to about 90%, up to about 100% as compared to the untreated sample.

Without wishing to be bound by theory, the antimicrobial enhancing activity of wollastonite may be associated with an increased pH in compositions comprising wollastonite.

Synthetic biocides and synthetic fungicides are widely used to control the growth of microorganisms in many products, such as paints and coatings. As used herein, "synthetic" refers to the use of chemical synthesis to form and/or break covalent chemical bonds. Widely used synthetic biocides and synthetic fungicides include, but are not limited to: 1, 2-Benzisothiazol-3 (2H) -one (BIT), a mixture of 5-chloro-2-methyl-2H-isothiazol-3-one and 2-methyl-2H-isothiazol-3-one (CMIT/MIT), 4, 5-dichloro-2-octyl-2H-isothiazol-3-one (DCOIT), 2-methyl-2H-isothiazol-3-one (MIT), 2-octyl-2H-isothiazol-3-one (DBOIT), dibromopropionamide (NPA), glutaraldehyde, 3-iodo-2-propynyl butylcarbamate (IPBC), terbutryn, 2-methyl-1, 2-benzothiazol-3 (2H) -one (MBIT), Benzamide, 2' -dithiobis (N-methyl) Dithiocarbamate (DTBMA), tetramethylol-ethinyldiurea (TMAD), ethylene glycol bis-hemiformal (EDDM), 2-bromo-2- (bromomethyl) glutaronitrile (DBDCB), permethrin (permethrin), propiconazole (DMI), chlorocresol (PCMC), bronopol (bronopol), Thiabendazole (TBZ), 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea (DCMU; diuron), 2-benzyl-4-chlorophenol (chlorofen), fenoxycarb (fenoxycarb), tebuconazole (tebuconazole), isoproturon (isoprotrotron), cyproconazole (prococonazole), fludioxonil (fluoronicotinil), azoxystrobin (zinc pyrithione), pyraclostrobin (Zn), thiamethoxam).

In certain embodiments, the synthetic biocide and/or synthetic fungicide is present in the antimicrobial composition in an amount of at least 0.01% by weight, up to about 0.1% by weight, or up to about 0.09% by weight, or up to about 0.08% by weight, or up to about 0.07% by weight, or up to about 0.06% by weight, or up to about 0.05% by weight, or up to about 0.04% by weight, or up to about 0.03% by weight, or up to about 0.02% by weight.

In certain embodiments, the synthetic biocide and/or synthetic fungicide is present in the antimicrobial composition in an amount of at least about 0.005 weight%, or at least about 0.0025 weight%, or at least about 0.00015 weight%, or at least about 0.0001 weight%, based on the total weight of the composition. In certain examples, the synthetic biocide and/or synthetic fungicide may be present in an amount according to the following list based on the total weight of the composition: 1, 2-benzisothiazol-3 (2H) -one (BIT) in an amount of at most 0.006%, a mixture of 5-chloro-2-methyl-2H-isothiazol-3-one and 2-methyl-2H-isothiazol-3-one (CMIT/MIT) in an amount of at most 0.00035%, 4, 5-dichloro-2-octyl-2H-isothiazol-3-one (DCOIT) in an amount of at most 0.01%, 2-methyl-2H-isothiazol-3-one (MIT) in an amount of at most 0.005%, 2-octyl-2H-isothiazol-3-One (OIT) in an amount of at most 0.1%, Dibromopropionamide (DBNPA) in an amount of at most 0.01%, glutaraldehyde in an amount of at most 0.01%, 3-iodo-2-propynylbutylcarbamate (IPBC) in an amount of up to 0.1%, desmetryn in an amount of up to 0.01%, 2-methyl-1, 2-benzothiazol-3 (2H) -one (MBIT) in an amount of up to 0.01%, benzamide, 2' -dithiobis (N-methyl) (DTBMA) in an amount of up to 0.1%, tetramethylol-acetylene diurea (TMAD) in an amount of up to 0.1%, ethylene glycol bis hemiformal (EDDM) in an amount of up to 0.1%.

In certain embodiments, the antimicrobial composition may comprise a resin, a dispersant, a coalescing agent, a defoamer, a filler, an extender, a neutralizing agent, and/or a thickener.

Suitable resins are polymeric resins, oligomeric resins and natural resins. The polymer resin may be suitable for forming a homopolymer or a copolymer. Suitable examples include polyacrylates, polyesters, polyamides, polyurethanes, polyimides, polyureas, polyethers, polysiloxanes, Vinyl Acetate Ethylene (VAE), styrene acrylates, fatty acid esters, and amine, alcohol, acid, ketone, ester, fluorinated and aromatic functionalized versions of these polymeric resins and physical blends and copolymers thereof.

Suitable coalescents include, for example, hydrophilic glycol ethers, e.g.Series, e.g.DPM andDPnB, a hydrophobic glycol ether,and block copolymers.

Suitable defoamers include, for example, surfactants, tributyl phosphate, blends of fatty polyoxyethylene esters plus fatty alcohols, fatty acid soaps, silicone emulsions and other silicone-containing compositions, waxes in mineral oil and inorganic particulates, blends of emulsified hydrocarbons and other commercially available compounds as defoamers. Suitable dispersants include polyacrylates (e.g., polyacrylateSeries), hydrophilic block copolymers, acrylic block copolymers, and nonionic surfactants.

Suitable filler or extender materials may include one or more of the following: hydrous kaolin, calcined kaolin, aggregated kaolin, calcium carbonate (ground or precipitated), talc, gypsum or other known white particulate mineral or pigment materials. Suitable neutralizing agents may include ammonium hydroxide, sodium hydroxide, and organic amines, such as dimethylamine, trimethylamine, and ethylamine.

In certain embodiments, the antimicrobial composition comprises a pigment, such as titanium dioxide, and a colorant.

The paint or coating composition may be water-based or non-water-based.

The antimicrobial compositions according to the present invention are suitable for use in a range of articles or substrates. Suitable substrates include wood, plastic, metal, and textiles. Methods of coating articles are known to the skilled person and include brushing, spraying and application with rollers.

In certain embodiments, the particulate mineral and/or composition may have one or more of the following effects:

-antibacterial action;

-an antifungal effect;

-an anti-algal effect;

-antibacterial enhancement;

-antifungal enhancement;

-an anti-algae potentiating effect;

-reducing the use of synthetic biocides and/or synthetic fungicides;

-more environmentally friendly control of microorganisms;

-retention of one or more properties of the paint or coating, such as opacity, gloss, hardness, scrub resistance, crack resistance and QUV resistance.

For the avoidance of doubt, the present application relates to subject matter described in the following numbered paragraphs.

1. An antimicrobial composition comprising an antimicrobial agent and wollastonite as an enhancer for the antimicrobial agent.

2. The antimicrobial composition of paragraph No. 1 wherein the wollastonite has not been treated.

3. The antimicrobial composition of paragraph No. 1 or paragraph No. 2, wherein the wollastonite has a median particle diameter d₅₀From 5 microns to 120 microns.

4. The antimicrobial composition of paragraph No. 1 or paragraph No. 2, wherein the wollastonite has a median particle diameter d₅₀From 5 microns to 20 microns.

5. The antimicrobial composition of any of the preceding numbered paragraphs, wherein the wollastonite has a BET surface area of 0.2m²G to 5.0m²/g。

6. The antimicrobial composition of any of the preceding numbered paragraphs, wherein the wollastonite is present in an amount of 2.5 to 37.5 weight percent based on the total weight of the composition.

7. The antimicrobial composition of any of the preceding numbered paragraphs, wherein the wollastonite has a shape factor of 2:1 to 20: 1.

8. The antimicrobial composition of any one of the preceding numbered paragraphs, wherein the antimicrobial agent inhibits, stops, and/or kills microbial growth.

9. The antimicrobial composition of paragraph number 8 wherein the microorganism is selected from bacteria, archaea, fungi, protozoa, algae and/or viruses.

10. The antimicrobial composition of paragraph number 8 or paragraph number 9, wherein the microorganism is selected from bacteria, fungi and/or algae.

11. The antimicrobial composition of any of the preceding numbered paragraphs, wherein the antimicrobial agent comprises a synthetic biocide.

12. The antimicrobial composition of any of the preceding numbered paragraphs, wherein the antimicrobial agent comprises a synthetic fungicide.

13. The antimicrobial composition according to any of the preceding numbered paragraphs, comprising the synthetic biocide and/or the synthetic fungicide in an amount of up to 0.10 wt. -%, preferably in an amount of from 0.001 to 0.1 wt. -%, based on the total weight of the composition, for example in an amount of from 0.001 to 0.02 wt. -%, based on the total weight of the composition, for example in an amount of from 0.001 to 0.01 wt. -%, based on the total weight of the composition.

14. The antimicrobial composition of any of the preceding numbered paragraphs, further comprising one or more of a resin, a dispersant, a coalescing agent, a defoamer, a filler, an extender, a thickener, and/or a neutralizer.

15. The antimicrobial composition of any one of the preceding numbered paragraphs, further comprising a pigment, such as titanium dioxide.

16. The antimicrobial composition of paragraph No. 15, wherein the pigment is titanium dioxide.

17. The antimicrobial composition of any one of the preceding numbered paragraphs, comprising, based on the total weight of the coating composition:

-0.001% to 0.1% of an antimicrobial agent; and

-wollastonite from 2.5% to 37.5% as biocide enhancing agent.

18. The antimicrobial composition of paragraph number 17, comprising from 0.001% to 0.02% of the antimicrobial agent, based on the total weight of the coating composition.

19. The antimicrobial composition of paragraph number 17, comprising from 0.001% to 0.01% of the antimicrobial agent, based on the total weight of the coating composition.

20. The antimicrobial composition of any one of the preceding numbered paragraphs, further comprising talc.

21. The antimicrobial composition of paragraph No. 20, comprising from 2.5% to 37.5% talc.

22. An antimicrobial composition as claimed in any one of the preceding numbered paragraphs, wherein the pH of the composition is below 10, preferably below 9.5.

23. The antimicrobial composition of any one of the preceding numbered paragraphs, wherein the antimicrobial agent is selected from the list of: 1, 2-Benzisothiazol-3 (2H) -one (BIT), a mixture of 5-chloro-2-methyl-2H-isothiazol-3-one and 2-methyl-2H-isothiazol-3-one (CMIT/MIT), 4, 5-dichloro-2-octyl-2H-isothiazol-3-one (DCOIT), 2-methyl-2H-isothiazol-3-one (MIT), 2-octyl-2H-isothiazol-3-one (DBOIT), dibromopropionamide (NPA), glutaraldehyde, 3-iodo-2-propynyl butylcarbamate (IPBC), dimethomon, 2-methyl-1, 2-benzothiazol-3 (2H) -one (MBIT), Benzamide, 2' -dithiobis (N-methyl) (DTBMA), tetramethylol-acetylene diurea (TMAD), ethylene glycol bis-hemiformal (EDDM), 2-bromo-2- (bromomethyl) glutaronitrile (DBDCB), permethrin, propiconazole (DMI), chlorocresol (PCMC), bronopol, Thiabendazole (TBZ), 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea (DCMU; diuron), 2-benzyl-4-chlorophenol, fenoxycarb, tebuconazole, isoproturon, cyproconazole, fludioxonil, pyrimethanil, zinc pyrithione, carbendazim, and thiamethoxam.

24. A paint or coating composition comprising the antimicrobial composition of any one of the preceding numbered paragraphs.

25. A paint or coating composition consisting of the antimicrobial composition of any one of the preceding numbered paragraphs.

26. The paint or coating composition comprising an antimicrobial composition of paragraph No. 25 wherein the synthetic biocide and/or synthetic fungicide is present in an amount of up to 0.10% by weight based on the weight of the composition.

27. Use of the antimicrobial composition of any of paragraphs nos. 1 to 26 to prevent microbial growth in a liquid and/or on an object.

28. Use of wollastonite as an antimicrobial enhancing agent.

29. Use of a blend of talc and wollastonite as an antimicrobial enhancing agent.

30. A method of preventing microbial growth in a liquid and/or on an object by applying the composition of any of numbered paragraphs 1 to 26 to the liquid and/or the object.

31. An article treated with the antimicrobial composition described in numbered paragraphs 1 to 26.

Examples

In the following examples, wollastonite 1 is the median particle diameter d₅₀8 μm (measured by laser Microtrac) and a surface area BET of 1.8m²Wollastonite in terms of/g. Wollastonite 2 is the median particle diameter d₅₀9 μm (measured by laser Microtrac) and a surface area BET of 1.6m²Wollastonite in terms of/g.

Example 1: in-can protection against bacteria, yeast and mold

A number of coating formulations were prepared according to table 1. Formulations 3 and 4 contain wollastonite according to the present invention. Formulations 1 and 2 are comparative examples containing mineral calcium carbonate and talc, with formulation 1 containing a typical amount of biocide and formulation 2 containing 9 times less biocide.

Table 1: paint formulation

The formation of table 1 was prepared by mixing hydroxyethyl cellulose thickener, pH neutralizer, biocide, dispersant, 0.3% defoamer, titanium dioxide and calcium carbonate, talc and/or wollastonite and stirring at 10m/s for 20 minutes. Subsequently, vinyl acetate-ethylene and a defoamer were added to the suspension with slow stirring.

The properties of formulations 1 to 4, such as viscosity, fineness of grind and optical properties, are shown in table 2.

Table 2: properties of formulations 1 to 4

Sterility control：

Test samples (0.1g or 0.1ml) were homogenized in a Skandex 450SK450 paint shaker for 5 minutes and surface plated in triplicate on each of the following media:

1) tryptic Soy Agar (TSA) (incubation at 30 ℃. + -. 2 ℃ for 5 days) for bacterial enumeration

2) Malt extract + chloramphenicol agar, selective medium for yeast and mold counts (incubation at 23 ℃. + -. 2 ℃ for 5 days).

After 5 days, the microbial count (expressed as "colony forming units" (CFU/g or CFU/ml) per gram or per milliliter of product) was determined visually. The test results are shown in Table 3.

As can be seen in table 3, all samples performed well in the yeast and mold tests, exhibiting CFU/g less than 10. Formulation 3 according to the invention performs well in tests involving bacteria, and also exhibits a CFU/g of less than 10. For formulation 4 according to the invention, a CFU/g of 26 was observed, which is an improvement over the comparative example according to formulation 2. This test shows that the formulation according to the invention is active against bacteria, yeasts and moulds, and wollastonite allows excellent results to be obtained with only very small amounts of biocide; that is, surprisingly, wollastonite is an enhancer for antimicrobial agents. It has to be noted that the combination of the two minerals wollastonite and talc shows even improved biocide enhancement.

Table 3: results of sterility testing¹

Recipe number	Bacterium (CFU/g)	Yeast/mold (CFU/g)
			1	23	<10
2	27	<10
			3	<10	<10
4	26	<10

¹The test method can detect microbial contamination as low as 10CFU/g or 10CFU/ml (detection limit). Contaminants below 10CFU/g or 10CFU/ml could not be detected.

In-tank challenge test

During challenge testing, 50g of test samples of each of formulations 1 to 4 of Table 1 were stored at 23 ℃. + -. 2 ℃. Inoculations were performed 4 times per week over a 5 week period. Samples were inoculated with the inoculum composition shown in table 4 and the number of bacteria, yeast and moulds was determined after 5 days. This inoculation and evaluation step was repeated four times. The results of these experiments are shown in table 5.

To assess contamination after each inoculation, 0.1ml samples were surface plated in triplicate on the following surfaces:

1) tryptic Soy Agar (TSA) for bacterial enumeration (5 days incubation at 30 ℃. + -. 2 ℃),

2) malt extract + chloramphenicol agar, selective medium for yeast and mold counts (incubation at 23 ℃. + -. 2 ℃ for 5 days).

After 5 days, the microbial count (expressed as "colony forming units" (CFU/g or CFU/ml) per gram or per milliliter of product) was determined visually. The test results are shown in Table 5.

Table 4: inoculum composition

Inoculum concentration: bacterium 10⁸CFU/ml；

Yeast&Mould ≈ 10⁶CFU/ml

Table 5: challenge results in cans¹

¹B ═ bacteria; y ═ yeast; m ═ mould

3 is more than or equal to 1000CFU/g or/ml, namely ineffective for preventing microbial contamination

2 ≥ 100-

1 is more than or equal to 10-99CFU/g or/ml which is the best for preventing the microbial contamination

0 is more than or equal to 0-9CFU/g or/ml, namely the best protection against microbial contamination

As can be seen from the results of table 5, inventive formulations 3 and 4 showed the best protection against microbial contamination in four inoculation cycles. In particular, formulation 3 showed very low microbial contamination, ranging from 0 to 9CFU/g, for each type of contaminant, i.e. bacteria, yeast or mold. Formulation 4 also performed very well, with no yeast and no mould in the first and second inoculations, only the bacterial concentration indicated by "1", representing absolute values of 16 and 13CFU/g, respectively. After the third and fourth inoculations, the absolute amounts of bacteria were 36 and 16CFU/g, respectively, and still were classified as "1". In addition, moulds were also present during inoculation 3 and 4, belonging to the "1" group, with absolute quantities of mould of 16CFU/g and 13CFU/g, respectively.

The results obtained with formulations 3 and 4 according to the invention are a significant improvement of comparative formulation 2, comparative formulation 2 containing only small amounts of synthetic biocide or synthetic fungicide, and no wollastonite. The result of formulation 3 is also an improvement over comparative formulation 1, which contains a typical amount of synthetic biocide 1. Formulation 4 was also comparable to comparative formulation 1, especially in the first inoculation cycle. This indicates that in the in-can formulation, the environmentally unfriendly and more toxic synthetic biocide could be partially replaced by wollastonite, while exhibiting the same good antimicrobial properties.

Example 2

Other paint formulations were prepared according to table 6. Formulations 7 and 8 contained wollastonite 1. Formulations 5 and 6 are comparative examples containing biocide, mineral calcium carbonate and talc, with formulation 5 containing a typical amount of biocide and formulation 6 containing 80 times less biocide. Formulation 7 contained 80 times less biocide than comparative formulation 5, while formulation 8 contained 9 times less biocide than comparative formulation 5.

TABLE 6

The methods for assessing sterility and in-can properties were the same as described in example 1.

As seen in table 7, this test demonstrates that the formulation of the invention is active against bacteria, yeast and mold, and wollastonite is able to achieve excellent results with very low amounts of biocide; that is, surprisingly, wollastonite is an antimicrobial agent enhancer.

Table 7: sterility results

Recipe number	Bacterium (CFU/g)	Yeast/mold (CFU/g)
			5	<10	<10
6	13	<10
			7	10	<10
8	<10	<10

As can be seen from the results of table 8, formulation 8 according to the invention showed the best protection against microbial contamination in four inoculation cycles. In particular, the microbial contamination is very low for each contaminant, i.e. bacteria, yeast or mold. The performance of formulation 7 was also very good, with no bacteria, no yeast and no mould in the first and second inoculations, and only in the third inoculation, the yeast concentration was expressed as "1", with absolute values representing 16CFU/g and 13 CFU/g.

The results obtained with formulations 7 and 8 according to the invention are a significant improvement over comparative formulation 6, which contains a small amount of biocide but no wollastonite in comparison to comparative formulation 6. The result of formulation 8 is also an improvement over comparative formulation 5, which comparative formulation 5 contains a typical amount of synthetic biocide, as it allows the same excellent results to be obtained while using only very small amounts of synthetic biocide. This indicates that in the in-can formulation, the environmentally unfriendly and more toxic synthetic biocide can be partially replaced by wollastonite while exhibiting the same good antimicrobial properties.

Table 8: in-can fruit

Example 3: protection of paint films against fungi (moulds and yeasts)

Formulations 9, 10 and 11 according to table 9 were used to test the protective effect of the paint films against fungi (moulds and yeasts) according to the procedure NFX 41520(Essai B).

Table 9: formulation for film testing

To obtain paint films of formulations 9, 10 and 11 having a dry thickness of about 100 μm, a wet paint of about. + -. 330 μm was applied to the glass fibre tissue and dried for 5 weeks at room temperature. The paint film on the glass fiber tissue was then placed in petri dishes containing nutrients for the fungus (each sample was replicated 3 times in a separate petri dish). Inoculants of 9 species (Alternaria alternata), Trichoderma viride (Trichoderma viride), Cladosporium polycarpum (Cladosporium herbarum), Aureobasidium pullulans (Aureobasidium pullulans), Chaetomium globosum (Chaetomium globosum), Aspergillus niger (Aspergillus niger), Penicillium funiculosum (Penicillium funiculosum), Paecilomyces variotii (Paecilomyces variotii) and Stachybotrys nigra (Stachybotrys atra)) were added to the nutrient solution (1ml) and to the film coating (1 ml). The Petri dishes were then placed under a controlled relative humidity of 95% + -1% and a temperature of 30 deg.C + -1% for 4 weeks. The samples were then visually inspected and assigned scores in the following manner:

0 ═ no visible fungal growth (decay);

1-fungal growth is limited (spread on the surface);

2 ═ fungal growth < 25% of the surface;

fungal growth accounts for 25 to 50% of the surface;

4 ═ 50% of the fungal growth > surface;

5 ═ 100% of the surface on which the fungus grows.

Table 10: results of tests for the protection of the paint film against fungi (moulds and yeasts)

As shown in fig. 1 and table 10, the inventive formulation 11 (fig. 1c) has improved antifungal activity compared to paint films having the same low amounts of synthetic biocide and synthetic fungicide, i.e., formulation 10 (fig. 1 b). Formulation 9 (fig. 1a) showed the best antifungal activity, but formulation 9 contained very large amounts of synthetic biocide and synthetic fungicide, i.e., 1.3% by weight of the composition. This high amount of synthetic biocide and synthetic fungicide makes formulation 9 of this comparative example undesirable due to its skin irritation and toxicity. The results show that the undesirable synthetic biocides and synthetic fungicides can be partially replaced by wollastonite to provide formulations with antifungal properties.

Example 4: protection of paint film against algae

Formulations 9, 10 and 11 according to table 9 were also used to test the protection of the paint film against algae.

To obtain paint films of formulations 9, 10 and 11 having a dry thickness of about 100 μm, a wet paint of about. + -. 330 μm was applied to a cement fiberboard (10 cm. times.20 cm) and dried for 2 months. The paint film was then placed in an aquarium with a simulation of day and night conditions, with 12 hours of illumination in the day, a temperature of 28 ℃ to 30 ℃ and a relative humidity of 85 to 100%. Once a day, the paint film was sprayed with the inoculation medium for 1 hour. The inoculation medium contained Tenuis baculosa (Stichococcus bacillus), Nostoc commune (Nostoc commune) and Scenedesmus vacuolatus (Scenedesmus vacuolatus) in 1 liter of an aqueous solution containing sodium nitrate (1g/L), magnesium sulfate (0.513g/L), dipotassium hydrogen phosphate (0.187g/L), disodium phosphate (0.063g/L), calcium chloride (0.058g/L), ammonium chloride (0.05g/L) and iron chloride (0.003 g/L). The samples were monitored for 11 weeks and visually inspected and assigned points as follows.

0 ═ no visible growth of algae;

algae limited growth (spread on the surface);

2 ═ 10% of the surface for algae growth;

algae growth < 25% of surface;

4 ═ 50% of the surface for algae growth;

5 ═ algae growth > 50% of the surface.

Table 11: results of the algae protection test of paint film

As shown in fig. 2 and table 11, the inventive formulation 11 (fig. 2c) has improved algae resistance over paint films with only small amounts of synthetic biocide and synthetic fungicide, i.e., formulation 10 (fig. 2 b). Formulation 9 (fig. 2a) showed the best anti-algal activity, but as mentioned above, formulation 9 contained very large amounts of synthetic biocide and synthetic fungicide, i.e. 1.3% by weight of the composition. The results for formulation 11 (containing wollastonite) are also closer to those obtained for formulation 9 (containing typical amounts of synthetic biocide/synthetic fungicide) than for formulation 10 (containing small amounts of synthetic biocide/synthetic fungicide). The results show that wollastonite is also a good enhancer of the anti-algal effect, showing good results even in the presence of small amounts of undesirable synthetic biocides and synthetic fungicides. Thus, wollastonite has been demonstrated to be a partial replacement for synthetic biocides and synthetic fungicides to provide formulations with anti-algae properties.