Coating agent composition

Abstract

[Problem] There have been problems such that the appearance of a coating film is deteriorated and the storage stability of a coating agent is deteriorated if an antifungal agent is added to a coating agent for outdoor installation for the purpose of imparting antifungal properties to the coating agent. Disclosed is a coating agent composition which contains the following components (A) to (D), wherein the component (B) is contained in an amount of 0.1 part by mass to 3.6 parts by mass inclusive with respect to 100 parts by mass of the component (A). Component (A): a silicone oligomer having an alkoxy group, Component (B): an organic antibacterial agent, Component (C): an organic solvent having no hydroxyl group and having a boiling point of 130°C or less, Component (D): a curing catalyst

Description

Coating composition

[0001] The present invention relates to a mildew-resistant coating composition for outdoor use.

[0002] Outdoor installations such as signs and vending machines, which are often installed outdoors, can be damaged by exposure to wind and rain, which can impair the design of the outdoor installation and even cause corrosion at the damaged areas. A method of using a coating agent beforehand to prevent scratches on the body is known (Patent Documents 1 and 2).

[0003] JP 2007-161989 A JP 2015-183014 A

[0004] However, even if a coating agent is applied to an outdoor installation in advance, if the installation is in a shaded area that is not exposed to sunlight or in a place with high humidity and frequent condensation, mold will grow on the surface, causing a problem of poor appearance. Therefore, when an anti-mold agent is added to impart mold resistance, problems arise in that the appearance of the coating film is deteriorated and the shelf life of the coating agent is reduced.

[0005] As a result of intensive research to achieve the above object, the inventors discovered a method for producing an outdoor coating composition that provides a good coating film appearance, good storage stability of the coating, excellent drying properties after application, and mildew resistance, and have thereby completed the present invention.

[0006] [1] A coating composition comprising the following components (A) to (D), with 0.1 to 3.6 parts by mass of component (B) per 100 parts by mass of component (A): Component (A): a silicone oligomer having an alkoxy group; Component (B): an organic antibacterial agent; Component (C): a hydroxyl-free organic solvent having a boiling point of 130°C or less; and Component (D): a curing catalyst. [2] The coating composition according to [1], wherein component (A) comprises component (A1): a silicone oligomer having only alkoxy groups, phenyl groups, and alkyl groups in the molecule and / or component (A2): a silicone oligomer having an alkoxy group and an amino group and / or a mercapto group in the molecule. [3] The coating composition according to [1] or [2], wherein component (B) is an iodine-based antibacterial agent. [4] The coating composition according to [3], wherein component (B) is diiodomethyl-paratolyl sulfone. [5] The coating composition according to any one of [1] to [4], wherein the component (D) is an organic titanium compound. [6] The coating composition according to any one of [1] to [5], further comprising an organic solvent having a boiling point exceeding 130°C. [7] The coating composition according to any one of [1] to [6], wherein the content of the component (D) is 0.1 to 20 parts by mass per 100 parts by mass of the component (A). [8] The coating composition according to any one of [1] to [7], wherein the component (C) comprises an acetate ester-based solvent and / or an aromatic hydrocarbon-based solvent. [9] A coating film formed by applying the coating composition according to any one of [1] to [8], followed by moisture curing while volatilizing the solvent.

[10] An outdoor object on which the coating film according to [9] has been formed.

[11] A coating film formed from the coating composition according to any one of [1] to [8].

[0007] The details of the present invention are described below. In this specification, "X to Y" means "X or more and Y or less," with the numerical values ​​(X and Y) before and after the "X" being included as upper and lower limits. Unless otherwise specified, operations and measurements of physical properties are performed at room temperature (20°C to 25°C) and a relative humidity of 40% RH to 50% RH. "A and / or B" includes each of A and B and all combinations of one or more of A and B, specifically meaning at least one of A and B, and including A, B, and combinations of A and B. When multiple "X to Y" are listed, for example, when "X1 to Y1 or X2 to Y2" is listed, the disclosure of each numerical value as an upper limit, the disclosure of each numerical value as a lower limit, and combinations of those upper and lower limits are all disclosed (i.e., they provide a legitimate basis for amendment). Specifically, amendments to X1 or more, amendments to Y2 or less, amendments to X1 or less, amendments to Y2 or more, amendments between X1 and X2, amendments between X1 and Y2, etc. must all be deemed lawful.

[0008] In one aspect of the present invention, there is provided a coating composition comprising the following components (A) to (D), with 0.1 to 3.6 parts by mass of component (B) per 100 parts by mass of component (A): component (A): silicone oligomer having an alkoxy group; component (B): organic antibacterial agent; component (C): organic solvent having a boiling point of 130°C or less that does not contain a hydroxyl group; and component (D): curing catalyst. This makes it possible to provide a coating composition, particularly a coating composition for outdoor use, that exhibits good coating film appearance and good coating storage stability, excellent drying properties after application, and is imparted with antifungal properties. Hereinafter, in this specification, the coating composition will also be simply referred to as the "composition."

[0009] <Component (A)> The silicone oligomer having an alkoxy group is an oligomer having a polysiloxane skeleton with siloxane bonds (Si—O—Si) in the main chain, and refers to a silicone oligomer having alkoxy groups present at the molecular chain terminals, side chains, etc. There are no particular limitations on the polymer as long as it has an alkoxy group, and it is a silicone compound that has alkoxy groups at the molecular chain terminals, side chains, etc., and has a linear structure, branched structure, or three-dimensional network structure. When component (A) is a silicone oligomer having an alkoxy group, the composition of the present invention can be cured at room temperature to form a hard and transparent cured film.

[0010] The silicon oligomer having an alkoxy group is derived, for example, from a silane compound having an alkoxy group. Specifically, when the silane compound having an alkoxy group has a hydrolyzable group bonded to a silicon atom, hydrolysis and dehydration condensation reactions proceed, forming a siloxane bond (Si—O—Si), and oligomerization of the silane compound having an alkoxy group proceeds, resulting in a silicon oligomer having an alkoxy group at the molecular chain end, side chain, or the like. In one embodiment, only a portion of the hydrolyzable groups contained in the silane compound are used for hydrolysis, and the remaining hydrolyzable groups can remain in the structure of the silicon oligomer.

[0011] Preferred forms of silane compounds having an alkoxy group for obtaining the above-mentioned silicone oligomer include polyfunctional alkoxysilane compounds such as dialkoxysilane compounds, trialkoxysilane compounds, and tetraalkoxysilane compounds, and monoalkoxysilane compounds (monofunctional alkoxysilane compounds). That is, the above-mentioned silicone oligomer is preferably a partial hydrolysis condensate of an alkoxysilane compound represented by the following formula (1). The alkoxysilane compounds represented by the following formula (1) may be used alone, or two or more types may be used in combination. Furthermore, the silicone oligomer may be used alone, or two or more types may be used in combination.

[0012]

[0013] In the above formula (1), R １ and R ２ are each independently a group selected from the group consisting of substituted or unsubstituted aliphatic hydrocarbon groups having 1 to 10 carbon atoms and aromatic hydrocarbon groups having 6 to 20 carbon atoms, and x is an integer of 0 to 3. １ and R ２ are preferably each independently a group selected from the group consisting of substituted or unsubstituted aliphatic hydrocarbon groups having 1 to 5 carbon atoms and aromatic hydrocarbon groups having 6 to 10 carbon atoms, and more preferably are each independently a group selected from the group consisting of a methyl group, an ethyl group, a propyl group, and a phenyl group.

[0014] As used herein, the term "substituted" refers to a hydrogen atom being replaced with another group, such as, but not limited to, a methyl group, an ethyl group, a propyl group, a butyl group, and the like.

[0015] In the above formula (1), x is an integer of 0 to 3. When the alkoxysilane compound represented by the above formula (1) is used alone, x is preferably an integer of 0 to 2, and more preferably 1 or 2. Furthermore, when two or more types of alkoxysilane compounds are used, it is preferable to use in combination at least a first alkoxysilane compound in which x is an integer of 1 to 3 and a second alkoxysilane compound in which x is an integer of 0 to 3 (however, this does not include the case where x = 3 for both the first alkoxysilane compound and the second alkoxysilane compound).

[0016] From the viewpoint of ease of synthesis, the alkoxy group is preferably an alkoxysilyl group, and examples thereof include polyfunctional alkoxysilyl groups such as dialkoxysilyl groups, trialkoxysilyl groups, and tetraalkoxysilyl groups, as well as monoalkoxysilyl groups. Note that component (A) may be used alone or in combination of two or more types.

[0017] The component (A) may have an organic group other than an alkoxy group in its side chain, and the organic group may be at least one selected from the group consisting of an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms), a methyl group, a phenyl group, and a reactive functional group (such as an epoxy group, an amino group, an acrylic group, a methacrylic group, or a mercapto group).

[0018] The content of the component (A) may be 3 to 90 mass %, or 10 to 50 mass %, based on the coating composition.

[0019] The component (A) used in the present invention preferably contains at least one of (A1) a silicone oligomer having only alkoxy groups, phenyl groups, and alkyl groups in the molecule, (A2) a silicone oligomer having an alkoxy group and an amino group and / or a mercapto group in the molecule, and (A3) a silicone oligomer having only alkoxy groups and alkyl groups in the molecule, and more preferably contains at least two of them.Moreover, the component (A) more preferably contains components (A1) and (A2) or components (A1) and (A3), and most preferably contains components (A1), (A2), and (A3).By containing these, excellent adhesion is achieved, and scratches in the coating film can be concealed by further coating on top.In addition, a preferred embodiment of the component (A) includes component (A1): a silicone oligomer having only alkoxy groups, phenyl groups, and alkyl groups in the molecule and / or component (A2): a silicone oligomer having an alkoxy group and an amino group and / or a mercapto group in the molecule. The component (A) used in the present invention may consist of only the components (A1), (A2), and (A3).

[0020] The component (A1) is a silicone oligomer having only alkoxy groups, phenyl groups, and alkyl groups in the molecule. In other words, the component (A) is a silicone oligomer that always has an alkoxy group, a phenyl group, and an alkyl group in the molecule. The component (A1) only needs to contain at least one alkoxy group, at least one phenyl group, and at least one alkyl group in the molecule, and does not have any other substituents containing organic groups. When the component (A1) is such a silicone oligomer, the cured product of the composition of the present invention after curing and drying has excellent flex resistance and is less likely to crack even when subjected to impact, etc.

[0021] The component (A1) is preferably a compound represented by the following formula (2):

[0022]

[0023] (In the above formula (2), R ３ is a phenyl group, and R ４ is an alkyl group, and Y is an integer of 1 to 3), and a compound represented by the following formula (3):

[0024]

[0025] (In the above formula (3), R ５ and R ６ is an alkyl group, and Z is an integer of 1 to 3. In one embodiment, the component (A1) is a partial hydrolysis condensate of an alkoxysilane compound represented by the above formula (2) or (3) and a tetraalkoxysilane compound (in the above formula (1), R １ and R ２ are each independently a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 10 carbon atoms, and x=0) and an alkoxysilane compound.

[0026] In addition to the alkoxysilane compounds represented by the above formulas (2) and (3), compounds having both an alkyl group and a phenyl group and represented by the following formula (4):

[0027]

[0028] (In the above formula (4), R ７ is a phenyl group, and R ８ and R ９ is an alkyl group, p is an integer of 1 or 2, q is an integer of 1 or 2, and p+q≦3), and the silicone oligomer of component (A1) may be synthesized by partial hydrolysis and condensation. From the viewpoint of flexibility and adhesion of the cured product, component (A1) is preferably a condensate of an alkoxysilane compound represented by formula (2) and an alkoxysilane compound represented by formula (3). In one embodiment, component (A1) may be a silicone oligomer obtained from a tetraalkoxysilane compound represented by formula (2), formula (3), or formula (4).

[0029] In one embodiment, R in formula (2) ４ may each independently represent a methyl group, an ethyl group, a propyl group, or a butyl group, and from the viewpoint of curability, is preferably a methyl group or an ethyl group, more preferably a methyl group.

[0030] In one embodiment, R in formula (3) ５ and R ６ may each independently be a methyl group, an ethyl group, a propyl group, or a butyl group, and from the viewpoint of adhesion, preferably each independently be a methyl group or an ethyl group, and more preferably both be methyl groups.

[0031] In one embodiment, the alkoxy groups contained in the tetraalkoxysilane compound for obtaining component (A1) include, but are not limited to, methoxy, ethoxy, propoxy, and butoxy groups. Of the four alkoxy groups contained in the tetraalkoxysilane compound for obtaining component (A1), one or more, two or more, three or more, or all four may be methoxy groups.

[0032] In one embodiment, R in formula (4) ８ and R ９may each independently be a methyl group, an ethyl group, a propyl group, or a butyl group, and from the viewpoints of curing drying properties, adhesion, and the like, preferably each independently be a methyl group or an ethyl group, and more preferably both be methyl groups.

[0033] The alkyl group in the component (A1) is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include, but are not limited to, a methyl group, an ethyl group, and a propyl group. From the viewpoints of flexibility, adhesion, and the like, the alkyl group in (A1) is preferably a methyl group.

[0034] The alkoxy group of the component (A1) is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably an alkoxy group having 1 to 3 carbon atoms. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group. From the viewpoint of flexibility, adhesion, and the like, a methoxy group is preferred.

[0035] The component (A1) has a kinematic viscosity at 25°C of 1 to 500 mm ２ s －１ It is preferable that the range is 10 to 350 mm. ２ s －１ and more preferably 10 to 300 mm ２ s －１ , and even more preferably 15 to 300 mm ２ s －１ and particularly preferably 30 to 280 mm ２ s －１ and most preferably 50 to 270 mm ２ s －１ The kinematic viscosity of component (A1) is 1 mm ２ s －１ By setting the thickness to 500 mm or more, a uniform coating can be formed. ２ s －１ The kinematic viscosity is measured by a viscosity measurement method in accordance with JIS Z 8803:2011. For example, the kinematic viscosity can be measured by a single cylindrical rotational viscometer (B-type viscometer).

[0036] Commercially available products of the component (A1) include, but are not limited to, KR-401N, KR-510, KR-9218, X-40-9227, and X-40-9312 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. These may be used alone, or two or more types may be used in combination.

[0037] The content of component (A1) is preferably 70 to 100 parts by mass, more preferably 75 to 99.5 parts by mass, and most preferably 80 to 99 parts by mass, per 100 parts by mass of all components (A). An amount of 70 parts by mass or more provides excellent impact resistance, while an amount of 100 parts by mass or less provides excellent adhesion. When two or more types of component (A1) are used, the content of component (A1) refers to the combined total.

[0038] The component (A2) is a silicone oligomer (excluding the component (A1)) that has an alkoxy group and an amino group and / or a mercapto group in the molecule. The component (A2) is a silicone oligomer that has an alkoxy group and an amino group and / or a mercapto group in the side chain or at the end of the polysiloxane chain. When the component (A2) is such a silicone oligomer, the cured product obtained by curing and drying the composition of the present invention exhibits further improved adhesion.

[0039] The alkoxy group in component (A2) is preferably an alkoxy group having 1 to 10 carbon atoms, and more preferably an alkoxy group having 1 to 5 carbon atoms. Examples of the alkoxy group in component (A2) include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. In terms of excellent long-term weather resistance, a methoxy group or an ethoxy group is preferred, and a methoxy group is more preferred. Furthermore, component (A2) may have an alkoxysilyl group (e.g., a monoalkoxysilyl group, a dialkoxysilyl group, or a trialkoxysilyl group) as a partial structure. The alkoxy group contained in the alkoxysilyl group may be the same as the alkoxy group in component (A1).

[0040] The component (A2) may contain either an amino group or a mercapto group, or may contain both. However, from the viewpoint of excellent adhesion, it preferably contains at least a mercapto group, and more preferably contains a mercapto group but not an amino group.

[0041] Commercially available products of component (A2) include, but are not limited to, KR-518 and KR-519 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0042] When the (A2) component is contained, the content of the (A2) component is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and most preferably 0.5 to 5 parts by mass, per 100 parts by mass of all the (A) components. An amount of 0.1 part by mass or more provides excellent adhesion, while an amount of 15 parts by mass or less minimizes the impact on weather resistance. When two or more types of (A2) component are used, the content of the (A2) component refers to the total value.

[0043] The component (A3) is a silicone oligomer having only alkoxy groups and alkyl groups in the molecule (excluding the components (A1) and (A2)). In other words, the component (C) is a silicone oligomer that always has an alkoxy group and an alkyl group in the molecule. It is sufficient for the component (A3) to have one or more alkoxy groups and one or more alkyl groups in the molecule.

[0044] The component (A3) is a compound represented by the following formula (5):

[0045]

[0046] (In the above formula (5), R １０ and R １１are each independently an alkyl group, for example, an alkyl group having 1 to 5 carbon atoms (saturated aliphatic hydrocarbon group), and r is an integer of 1 to 3. The compound represented by formula (5) above may be used alone, or multiple types may be used. Component (A3) may also be a silicone oligomer obtained from an alkoxysilane compound represented by formula (5) above and a tetraalkoxysilane compound. Furthermore, the silicone oligomer used as component (A3) may be used alone, or two or more types may be used in combination. R in formula (5) above １０ Examples of the groups include a methyl group, an ethyl group, a propyl group, and a butyl group. From the viewpoint of adhesion, the component (A3) is preferably R １０ is a silicone oligomer that is a condensation product of an alkoxysilane compound in which methyl groups can be used.

[0047] The alkyl group of the component (A3) is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and a propyl group. From the viewpoint of adhesion of the cured product, the alkyl group of the component (A3) is preferably a methyl group.

[0048] The alkoxy group of the component (A3) is preferably an alkoxy group having 1 to 5 carbon atoms, and more preferably an alkoxy group having 1 to 3 carbon atoms. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group. From the viewpoint of adhesion of the cured product, a methoxy group is preferred.

[0049] Commercially available products of component (A3) include, but are not limited to, KC-89S, KR-500, X-40-9225, X-40-9246, and X-40-9250 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0050] When the (A3) component is contained, the content of the (A3) component is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, and most preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of all the (A) components. An amount of 0.1 part by mass or more provides a coating agent composition that is excellent in adhesion, and an amount of 15 parts by mass or less provides a coating agent composition that is excellent in flexibility and does not generate cracks. When two or more types of the (A3) component are used, the content of the (A3) component refers to the total value.

[0051] The component (B) used in the present invention is an organic antibacterial agent. By using an organic antibacterial agent as the antibacterial agent, the solubility and storage stability of a composition containing components (A), (C) to (D) are significantly improved. An organic antibacterial agent refers to an organic compound that has the effect of inhibiting the growth of microorganisms such as bacteria and fungi such as mold. Such an organic antibacterial agent is not particularly limited, and conventionally known organic antibacterial agents can be used.

[0052] The component (B) is not particularly limited, but examples thereof include pyridine-based antibacterial agents such as densil (2,3,5,6-tetrachloro-4-(methylsulfonyl)pyridine); thiazoline-based antibacterial agents such as OIT (2-n-octyl-4-isothiazolin-3-one), MIT (2-methyl-4-isothiazolin-3-one), CMI (5-chloro-2-methyl-4-isothiazolin-3-one), BIT (1,2-benzisothiazolone), and n-butyl BIT (N-n-butyl-1,2-benzisothiazolone-3); triazine antibacterial agents such as 2,4-dichloro-6-methoxy-1,3,5-triazine; imidazole antibacterial agents such as thiabendazole (2-(4-thiazolyl)-benzimidazole) and carbendazim (methyl-2-benzimidazole carbamate); triazole antibacterial agents such as tebuconazole ((±)-α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol); diiodomethyl-paratolylsilane; iodine-based antibacterial agents such as iodine, polyvinylpyrrolidone iodine, and 3-iodo-2-propynyl butylcarbamate; arsenic-based antibacterial agents such as 10,10'-oxybis-10H-phenoxyarsine; ether-based antibacterial agents such as triclosan; organochlorine-based antibacterial agents such as triclocarban (3,4,4'-trichlorocarbanilide), halocarban (4,4-dichloro-3-(3-fluoromethyl)-carbanilide), chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile), dichloroisocyanuric acid, and trichloroisocyanuric acid biguanide antibacterial agents such as chlorhexidine gluconate, chlorhexidine hydrochloride, polybiguanide hydrochloride, polyaminopropyl biguanide, and polyhexamethylene biguanide; sulfamide antibacterial agents such as dichlofluanid and tolifluanid; quaternary ammonium chlorine antibacterial agents such as benzothonium chloride, cetylpyridinium chloride, and diallyldimethylammonium chloride; aldehyde antibacterial agents such as BCA (α-bromocinnamaldehyde); ester antibacterial agents such as lauricidin (glycerol laurate);Examples of suitable antibacterial agents include phenolic antibacterial agents such as butylparaben (butyl-p-hydroxybenzoate) and sodium orthophenylphenol; and carbamate antibacterial agents such as sodium N-methyldithiocarbamate. From the viewpoint of solubility in component (C), component (B) preferably contains an iodine-based antibacterial agent containing one or more iodine atoms, more preferably at least one selected from the group consisting of diiodomethyl-paratolyl sulfone, polyvinylpyrrolidone iodine, and 3-iodo-2-propynyl butylcarbamate, even more preferably diiodomethyl-paratolyl sulfone, and most preferably diiodomethyl-paratolyl sulfone.

[0053] The (B) component is contained in an amount of 0.1 to 3.6 parts by mass relative to 100 parts by mass of the (A) component. By containing 0.1 parts by mass or more of the (B) component, antifungal properties can be imparted, and by containing 3.6 parts by mass or less of the (B) component, it is possible to maintain good coating film appearance. From the viewpoint of storage stability of the coating composition, the (B) component is preferably contained in an amount of 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, relative to 100 parts by mass of the (A) component. The (B) component may be contained in an amount of 0.1 to 3.6 parts by mass, 0.15 to 3.6 parts by mass, 0.2 to 3.0 parts by mass, 0.25 to 2.5 parts by mass, or 0.3 to 2.0 parts by mass relative to 100 parts by mass of the (A) component.

[0054] The component (C) used in the present invention is an organic solvent that does not contain a hydroxyl group and has a boiling point of 130°C or less. The boiling point referred to here is the temperature at which the saturated vapor pressure of the liquid is equal to 1 atmosphere (101.3 kPa). When multiple organic solvents are contained, the boiling point does not refer to the boiling point of the mixture, but rather to the boiling points of the individual pure substances. The absence of a hydroxyl group in component (C) allows the coating composition to maintain good shelf life, and the boiling point of 130°C or less allows the coating composition to have excellent drying properties or maintain good coating film appearance.

[0055] The component (C) is not particularly limited, but examples thereof include ester solvents, ketone solvents, ether solvents, and hydrocarbon solvents. Examples of ester solvents include methyl acetate (boiling point 57°C), ethyl acetate (boiling point 77°C), butyl acetate (boiling point 126°C), and isobutyl acetate (boiling point 117°C). Examples of ketone solvents include acetone (boiling point 56°C), methyl ethyl ketone (boiling point 80°C), and methyl isobutyl ketone (boiling point 116°C). Examples of ether solvents include diethyl ether (boiling point 35°C), diisopropyl ether (boiling point 69°C), and tetrahydrofuran (boiling point 66°C). Examples of hydrocarbon solvents include aromatic hydrocarbon solvents such as toluene (boiling point 111°C), and hydrocarbon solvents such as normal hexane (boiling point 68°C), isohexane (boiling point 60°C), and isooctane (boiling point 99°C). There is no lower limit for the boiling point of the component (C), but from the viewpoint of the shelf life of the coating composition, it is preferably 25°C or higher, more preferably 60°C or higher, and most preferably 75°C or higher. The boiling point of component (C) may be 25 to 130°C, 60 to 130°C, or 70 to 130°C. Furthermore, from the viewpoint of maintaining good coating film appearance, ester-based solvents and / or hydrocarbon-based solvents are preferred, and acetate ester-based solvents and / or aromatic hydrocarbon-based solvents are more preferred, and at least one solvent selected from the group consisting of ethyl acetate, butyl acetate, and toluene is even more preferred. The component (C) may be used alone or in combination of two or more types.

[0056] The component (C) is preferably contained in an amount of 1 to 500 parts by mass, more preferably 10 to 300 parts by mass, even more preferably 40 to 100 parts by mass, even more preferably more than 50 parts by mass but not more than 100 parts by mass, and particularly preferably 60 to 85 parts by mass, per 100 parts by mass of the component (A). By containing the component (C) in the above range, good solubility can be maintained.

[0057] The component (D) used in the present invention is a curing catalyst. Component (D) is a compound that causes the alkoxy groups contained in component (A) to react with moisture in the air and undergo a condensation reaction. As component (D), a conventionally known compound can be appropriately selected and used, and a compound having the required properties in terms of reaction activity, storage stability, transparency, etc. can be selected from, for example, organotin compounds, organozinc compounds, organotitanium compounds, organozirconium compounds, organoaluminum compounds, organonickel compounds, inorganic acid compounds, organic acid compounds, inorganic base compounds, and organic base compounds. These compounds may be used alone or in combination of two or more.

[0058] Examples of the organic tin compound include dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, dioctyltin diacetate, dibutyltin bisacetylacetate, and dioctyltin bisacetyllaurate.

[0059] Examples of organic zinc compounds include zinc triacetylacetonate, zinc-2-ethylhexoate, zinc naphthenate, and zinc stearate.

[0060] Examples of the organic titanium compound include tetrabutyl titanate, tetranonyl titanate, tetrakisethylene glycol methyl ether titanate, tetrakisethylene glycol ethyl ether titanate, and bis(acetylacetonyl)dipropyl titanate.

[0061] Examples of the organic zirconium compound include zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium dibutoxydiacetylacetonate, zirconium tetra-normal propoxide, zirconium tetraisopropoxide, zirconium tetra-normal butoxide, zirconium acylate, zirconium tributoxystearate, zirconium octoate, zirconyl (2-ethylhexanoate), and zirconium (2-ethylhexoate).

[0062] Examples of the organic aluminum compounds include aluminum salt compounds such as aluminum octylate, aluminum triacetate, and aluminum tristearate; aluminum alkoxide compounds such as aluminum trimethoxide, aluminum triethoxide, aluminum triallyloxide, and aluminum triphenoxide; aluminum methoxybis(ethyl acetoacetate), aluminum methoxybis(acetylacetonate), aluminum ethoxybis(ethyl acetoacetate), aluminum ethoxybis(acetylacetonate), aluminum isopropoxybis(ethyl acetoacetate), and aluminum isopropoxybis(methyl acetoacetate); Examples of aluminum chelate compounds include aluminum isopropoxybis(t-butylacetoacetate), aluminum butoxybis(ethylacetoacetate), aluminum dimethoxy(ethylacetoacetate), aluminum dimethoxy(acetylacetonate), aluminum diethoxy(ethylacetoacetate), aluminum diethoxy(acetylacetonate), aluminum diisopropoxy(ethylacetoacetate), aluminum diisopropoxy(methylacetoacetate), aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), and aluminum octylacetoacetate diisoproprate.

[0063] As the component (D), it is preferable to use a curing catalyst other than an organotin compound from the viewpoint of legal regulations. Among them, an organotitanium compound is more preferable, a titanium alkoxide is more preferable, and tetrabutyl titanate is most preferable, from the viewpoint of achieving both curability and storage stability.

[0064] The content of the component (D) is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and most preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A). A content of the component (D) of 0.1 parts by mass or more results in a coating agent composition with excellent curability, while a content of 20 parts by mass or less results in a coating agent composition with excellent storage stability. When two or more types of component (D) are used, the content of the component (D) refers to the total value.

[0065] From the viewpoint of workability and application properties, the coating agent composition of the present invention preferably contains an organic solvent (hereinafter also referred to as component (E)) having a boiling point exceeding 130°C (preferably 131°C or higher). By including an organic solvent having a boiling point exceeding 130°C, the components (A) and (D) can be uniformly dissolved or dispersed, and a uniform thin film can be formed by dilution. The organic solvent having a boiling point exceeding 130°C (preferably 131°C or higher) is not particularly limited as long as it is capable of uniformly dissolving or dispersing the components (A) to (D) and is liquid at 25°C and does not react with the components (A) to (D). Examples of the organic solvent include naphthenic hydrocarbons and their halides, paraffinic hydrocarbons and their halides, isoparaffinic hydrocarbons and their halides, ether compounds, alcohol compounds, phenolic compounds, glycol compounds, ketone compounds, ester compounds, and crude oil fractions. When selecting a substance consisting of a compound that easily absorbs water in a system, such as low-molecular-weight alcohols, ethers, or acetone, it is desirable to use a substance that has been purified by distillation or other methods to remove as much water as possible. From the viewpoint of forming a more uniform thin film, component (E) is preferably an organic solvent having a boiling point of at least 150° C. The boiling point of component (E) may be greater than 130° C. and not greater than 350° C., or may be from 131 to 300° C.

[0066] Preferred examples of the organic solvent include ketone compounds, ester compounds, ether compounds, alcohol compounds, paraffins, isoparaffin hydrocarbon compounds, naphthenic hydrocarbon compounds, and crude oil distillation components, and most preferred are paraffins, isoparaffin hydrocarbon compounds, naphthenic hydrocarbon compounds, and crude oil distillation components. In one embodiment, the organic solvent of component (E) is preferably a linear or branched saturated hydrocarbon having 5 to 15 carbon atoms, more preferably a linear or branched saturated hydrocarbon having 6 to 14 carbon atoms, even more preferably a branched saturated hydrocarbon having 6 to 14 carbon atoms, and may also be a linear or branched saturated hydrocarbon having 9 to 14 carbon atoms. Among these, from the viewpoints of workability and coatability, 2,2,4,6,6-pentamethylheptane can be preferably used as the organic solvent of component (E).

[0067] In one preferred embodiment, the organic solvent contained in the coating composition is a combination of an acetate ester-based solvent and / or an aromatic hydrocarbon-based solvent (preferably at least one selected from the group consisting of ethyl acetate, butyl acetate, and toluene) and a linear or branched saturated hydrocarbon having 5 to 15 carbon atoms (preferably a linear or branched saturated hydrocarbon having 6 to 14 carbon atoms, more preferably a branched saturated hydrocarbon having 6 to 14 carbon atoms, and even more preferably 2,2,4,6,6-pentamethylheptane).

[0068] From the viewpoint of the effects of the present invention, the mass ratio of the content of the component (C) to the component (E) may be component (C):component (E)=1:0.5 to 10, may be more than 1:1 but not more than 10, or may be 1:2 to 5.

[0069] The content of the organic solvent of component (E) is preferably 30 to 90 mass %, more preferably 40 to 75 mass %, and most preferably 50 to 65 mass %, based on the total amount of the coating composition. When the content of the organic solvent of component (E) is 30 mass % or more, a coating composition having excellent workability and application properties can be obtained, and when it is 90 mass % or less, a coating composition having excellent scratch concealing properties can be obtained.

[0070] In addition to the above-mentioned components, various additives may be added as optional components to the coating composition of the present invention, as needed, within the range that does not impair the effects of the present invention. Examples of additives include silane coupling agents (excluding component (A)), plasticizers, fillers, storage stabilizers, tackifiers, organic or inorganic pigments, rust inhibitors, antifoaming agents, dispersants, surfactants, viscoelasticity adjusters, and thickeners.

[0071] One embodiment of the coating agent composition of the present invention does not contain an organic solvent that has a hydroxyl group and a boiling point of 130° C. or lower. One embodiment of the coating agent composition of the present invention does not contain propanol.

[0072] The method for preparing the coating composition of the present invention is not particularly limited, and conventionally known methods can be appropriately employed. For example, predetermined amounts of components (A), (B), (C), (D), and any optional components are weighed and added to a stirring vessel sequentially or simultaneously in any order, and then mixed using a mixing means such as a three-one motor, preferably while vacuum degassing. Preferably, component (D) is added last. Adding component (D) last can prevent the curing reaction from proceeding at an undesired stage. The mixing temperature is preferably 10 to 50°C, and the mixing time is preferably 0.1 to 5 hours.

[0073] The coating composition of the present invention may be applied by any known method, including hand application using fibers impregnated with the composition, brush application, and machine application using an automated machine. Preferably, the coating composition of the present invention is impregnated into a dry sponge, rag, or other fiber, and the impregnated coating composition is manually spread thinly over the surface of a steel plate or coated plate. The volatile components are then evaporated by natural drying or forced drying using a dryer or the like. During this process, component (A), a reactive component contained in the coating composition, comes into contact with moisture in the air and undergoes a hydrolysis reaction due to the action of component (D). Concurrently with the evaporation of the volatile components, the coating composition undergoes crosslinking and curing on the steel plate or coated plate, forming a resin-like cured product. The curing temperature is not particularly limited, but is preferably 10 to 50°C, more preferably 15 to 30°C. The relative humidity is preferably 40% RH or higher, and the curing time is preferably 0.1 hours or longer but less than 24 hours.

[0074] The coating composition applied by the above application method preferably has a film thickness of 1 to 15 μm after drying, more preferably 2 to 10 μm, and most preferably 4 to 7 μm. If it is 1 μm or more, excellent scratch concealing properties are obtained, and if it is 15 μm or less, the coating film is less likely to crack due to impact or bending.

[0075] The coating composition of the present invention can be applied to substrates such as various metals, glass, ceramics, resins, and color steel sheets. The term "outdoor" used in reference to outdoor installations refers to any location exposed to the outside air, i.e., any location other than indoors that can be shielded from the outside air, including locations enclosed by a roof or fence. Examples of such installations include oil tanks for storing flammable fuels such as heavy oil, water tanks, chemical tanks, and other fluid storage tanks; cranes; outdoor equipment; and mechanical devices such as signs, vending machines, and signs. The coating composition is particularly suitable for use on signs, signs, and vending machines because of its excellent adhesion to impacts and scratch concealment properties. In one aspect of the present invention, an outdoor installation coated with the cured product of the coating composition is also provided.

[0076] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, tests were carried out in an environment of 25°C and 55% RH.

[0077] [Examples 1 to 5 and Comparative Examples 1 to 11] The following components were prepared to prepare coating compositions. Hereinafter, the coating composition will also be simply referred to as the composition. Component (A): Silicone oligomer having an alkoxy group (a-1) Silicone oligomer having a methoxy group, a methyl group, and a phenyl group (X-40-9312) Kinematic viscosity: 250 mm ２ s －１(a-2) Silicone oligomer having a methoxy group, a methyl group, and a mercapto group (KR-519, manufactured by Shin-Etsu Chemical Co., Ltd., corresponding to component (A2)) (a-3) Silicone oligomer having a methoxy group and a methyl group (X-40-9250, manufactured by Shin-Etsu Chemical Co., Ltd., corresponding to component (A3)) (B) component: organic antibacterial agent (b-1) Diiodomethyl paratolyl sulfone (PBM ON, manufactured by Pacific Beam Co., Ltd.) (B') component: comparative component for component (B) (b'-1) Monovalent copper compound nanoparticle dispersion solution ((Cuffitec, manufactured by NBC Meshtec Co., Ltd., 90 to 99.5% ethyl acetate as solvent) (b'-2) Silver / zeolite inorganic antibacterial agent (Zeomic, Sinanen Zeomic Co., Ltd.) Component (C): an organic solvent having a boiling point of 130°C or less and not having a hydroxyl group (c-1) Butyl acetate (boiling point 126°C) reagent (c-2) Toluene (boiling point 111°C) reagent (c-3) Ethyl acetate (boiling point 77°C) reagent Component (C'): a comparison component of component (C) (organic solvents having a boiling point of more than 130°C correspond to component (E)) (c'-1) Cyclopentanone (boiling point 131°C) reagent (c'-2) Aromatic hydrocarbon having 9 carbon atoms (boiling point 159 to 172°C, Ipzol 100 manufactured by Idemitsu Kosan Co., Ltd.) (c'-3) Aromatic high-boiling hydrocarbon solvent (boiling point 234 to 284°C, Solvesso 200 manufactured by Ando Parachemie Co., Ltd.) (c'-4) Isopropanol (boiling point 86°C) reagent (c'-5) Normal propanol (boiling point 97°C) reagent (c'-6) 2,2,4,6,6-pentamethylheptane (boiling point 179-182°C, 181 solvent, manufactured by Taishin Chemical Co., Ltd.) Component (D): curing catalyst (d-1) Tetrabutyl titanate (D-25, manufactured by Shin-Etsu Chemical Co., Ltd.) The compositions of Examples 1 to 5 and Comparative Examples 1 to 11 were produced as follows: Components (A) to (D) were weighed and stirred for 15 minutes using a Three-One Motor manufactured by Shinto Scientific Co., Ltd. to obtain coating agent compositions. Detailed amounts prepared are shown in Table 1, and all values ​​are expressed in parts by mass. The test results described below are also shown in Table 1.

[0078] <Drying Property Test> 2 ml of the composition was soaked into tissue paper. The composition was uniformly applied by hand to the entire white-coated surface of a white-coated plate (material: SPCC-SD (cold-rolled steel plate), standard: JIS G 3141:2017, dimensions: 0.8 mm × 70 mm × 150 mm, electrochemically coated and then coated with a white amino alkyd paint on one side, no clear coat, manufactured by Asahi B-Techno Co., Ltd.) using the tissue paper to prepare a test specimen. The test specimen was placed with the long side vertically against a wall, and the coated surface of the test specimen positioned at least 1 cm above the base was measured for drying time using a method conforming to the tactile dryness test specified in JIS K 5600-1-1:1999. After application of the composition, measurements were performed on different coated surfaces at 1-minute intervals at 25°C and 55% RH to evaluate drying property. From the viewpoint of workability, the drying time is preferably less than 30 minutes. The evaluation criteria are as follows.

[0079] Drying property evaluation criteria: ∘: The time it takes for the fingertip to come clean when lightly touched to the center of the coating surface is less than 30 minutes; x: The time it takes for the fingertip to come clean when lightly touched to the center of the coating surface is more than 30 minutes. <Coating appearance test> The composition was applied to a white coated panel using the same method as for measuring the drying time. The drying conditions were 25°C, 55% RH, and the test piece was left standing against a wall with the long side vertical for 24 hours, and the coating appearance was confirmed visually. From the viewpoint of not impairing the design of the adherend, it is preferable that the coating appearance is colorless and transparent, and that there is no unevenness on the surface due to dripping or cure shrinkage.

[0080] Coating appearance evaluation criteria: ○: Colorless and transparent with no unevenness on the surface; △: No unevenness on the surface, but crystals were observed in some parts of the coating film, causing it to become cloudy; ×: Unevenness occurred on the coating film surface, and crystals were observed in the coating film, causing it to become cloudy.

[0081] <Adhesion Test (Tape Peel Test)> The composition was applied to a white-painted panel using the same method as in the drying test. The test specimen was left standing for 24 hours with the long side facing vertically against a wall under drying conditions of 25°C and 55% RH. Approximately 3 cm of adhesive tape (cellophane tape, manufactured by Nichiban Co., Ltd.) was attached to the coating surface of the prepared test specimen (the surface at least 1 cm inside each end of the test specimen). The adhesive tape was then peeled off, and the adhesion was visually confirmed according to the following evaluation criteria to determine whether the coating film was peeled off from the white-painted panel by the adhesive tape.

[0082] Adhesion evaluation criteria: ◯: no peeling; ×: peeling.

[0083] <Scratch Concealment Test> The black painted surface of a black painted plate (material: SPCC-SD (cold rolled steel plate), standard: JIS G 3141:2017, dimensions: 0.8 mm × 70 mm × 150 mm, one side of which was coated with a black amino alkyd coating after chemical electrodeposition, no clear coat, manufactured by Asahi B-Techno Co., Ltd.) was scratched with #40 sandpaper. The scratched area was washed with alcohol and dried, and then the composition was applied over the scratch using the same method as in the drying time measurement. The test piece was then placed upright against a wall with the long side vertical and dried for 24 hours in an environment of 25 ° C. and 55% RH. After aging, the test piece was placed upright against a wall with the long side vertical, and the scratches on the test piece were visually confirmed from a distance of 1 m from the test piece according to the following evaluation criteria, and the concealment was evaluated. By making the scratches invisible, the design is also excellent.

[0084] Evaluation criteria for scratch concealment: ◯: Scratches are visible; ×: Scratches are not visible.

[0085] <Impact Resistance Test> A composition was applied to a steel plate (SPCC-SD (cold-rolled steel plate), standard: JIS G 3141:2017, dimensions: 0.8 mm x 70 mm x 150 mm) using the same method as in the drying test. The drying conditions were an environment of 25°C and 55% RH, and the test piece was left standing for 24 hours with the long side facing upright and leaning against a wall so that it was vertical. A weight drop test was performed on the coated surface of the prepared test piece using a DuPont impact tester manufactured by Tester Sangyo, and the impact resistance of the coating film was visually confirmed according to the following evaluation criteria. The test was performed over a drop distance of 500 mm with a weight of 500 g. Detailed test methods follow JIS K 5600-5-3:1999. Impact Resistance Evaluation Criteria ○: No peeling or cracking of the coating film ×: Peeling or cracking of the coating film was observed

[0086] <Coating Film Conformity Bending Test> Test specimens were prepared using the same method as in the impact resistance test. The test specimens were left standing with the long side vertical and leaning against a wall in a drying environment of 25°C and 55% RH for 24 hours. The prepared test specimens were subjected to a mandrel bending test using a mandrel bending tester manufactured by Ueshima Seisakusho, and the coating film conformity was confirmed according to the following evaluation criteria. The diameter of the mandrel used was φ3 / 8 inches. Detailed test methods were in accordance with JIS K 5600-5-1.

[0087] Evaluation criteria for coating film conformability: ◯: No peeling or cracking of the coating film; ×: Peeling or cracking of the coating film was observed.

[0088] <Solubility Test> 10 ml of the composition was placed in a 20 ml glass vial, sealed, shaken by hand 10 times, and allowed to stand for 1 minute, after which it was visually confirmed whether all the components were completely dissolved in the solvent.

[0089] ◯: All ingredients dissolved.

[0090] x: Some components remained undissolved.

[0091] <Storage Stability Test> 10 ml of the composition was placed in a 20 ml glass vial, sealed, and left to stand for 7 days in an environment of 25°C and 55% RH, and the storage stability of the composition was confirmed visually. In the storage stability test, it is preferable that no changes occur in the composition. The evaluation criteria are as follows. If the solubility test was x, it was judged based on whether new discoloration and / or precipitate had occurred since the state after the dissolution test.

[0092] Storage stability evaluation criteria: ◯: Colorless and transparent.

[0093] ×: Discoloration and / or precipitation occurred.

[0094]

[0095]

[0096] Furthermore, antifungal tests were carried out on Examples 1, 4, 5, Comparative Examples 7 and 9, and the results are shown in Table 2.

[0097] <Fungicide Test> 2 ml of each composition was impregnated into a 2 cm square sponge. Using the sponge, the composition was manually and uniformly applied to the entire surface of a polypropylene test piece (50 mm x 50 mm x 1.0 mm) to a film thickness of approximately 100 μm before drying. The test piece was placed horizontally with the coated side facing up and allowed to stand at 25°C and 55% RH for 24 hours. The test piece was then placed on a potato dextrose agar plate in a Petri dish, and a mixed spore suspension containing five types of fungal spores (Aspergillus niger, Penicillium citrinum, Rhizopus oryzae, Cladosporium cladosporioidus, and Chaetomium globosum) prepared using a humectant-added inorganic salt solution was inoculated onto the entire surface of the test piece and the agar plate. After inoculation, the agar plate was incubated at 28±5°C and 90±5% relative humidity for 28 days, and the surface of the sample after incubation was observed visually or under a stereomicroscope to evaluate the fungicide activity. Details are in accordance with JIS Z 2911:2018. Evaluation criteria are as follows:

[0098] ○: No growth of mycelia was observed in the inoculated part of the test piece. △: Mycelia growth was observed in less than 1 / 3 of the total area of ​​the inoculated part of the test piece. ×: Mycelia growth was observed in more than 1 / 3 of the total area of ​​the inoculated part of the test piece.

[0099]

[0100] As can be seen from Table 1, Examples 1 to 5, which contain components (A) to (D), exhibited excellent drying properties, scratch concealing properties, adhesion, coating film conformability, and impact resistance, as well as excellent solubility, storage stability, and coating film appearance. Furthermore, as can be seen from Table 2, compositions containing component (B) were also confirmed to have mildew resistance. On the other hand, Comparative Example 1 did not contain component (C), resulting in poor drying properties. Furthermore, Comparative Examples 2 to 6 used component (C') instead of component (C), resulting in poor composition storage stability and adverse effects on coating film appearance. Furthermore, Comparative Examples 7 and 8 contained excessive amounts of component (B), resulting in poor solubility and storage stability of the composition and adverse effects on coating film appearance. Comparative Example 9, which does not contain component (B), lacks mildew resistance. Furthermore, Comparative Examples 10 and 11 used component (B'), resulting in poor composition solubility and storage stability and adverse effects on coating film appearance.

[0101] The coating composition of the present invention has excellent adhesion, particularly against impact and bending, and also has antifungal properties, so it can be applied to substrates such as various metals, glass, ceramics, resins, etc. Furthermore, because it has the ability to conceal scratches, it is suitable for use on items that are installed outdoors, such as signs, labels, and vending machines.

[0102] This application is based on Japanese Patent Application No. 2024-42606, filed on March 18, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A coating composition comprising the following components (A) to (D), with component (B) being 0.1 to 3.6 parts by mass per 100 parts by mass of component (A): Component (A): a silicone oligomer having an alkoxy group; Component (B): an organic antibacterial agent; Component (C): an organic solvent having a boiling point of 130°C or less and not having a hydroxyl group; and Component (D): a curing catalyst.

2. The coating composition according to claim 1, wherein the component (A) comprises component (A1): a silicone oligomer having only alkoxy groups, phenyl groups, and alkyl groups in the molecule; and / or component (A2): a silicone oligomer having alkoxy groups, amino groups, and / or mercapto groups in the molecule.

3. The coating composition according to claim 1 or 2, wherein component (B) is an iodine-based antibacterial agent.

4. The coating composition according to claim 3, wherein component (B) is diiodomethyl-paratolyl sulfone.

5. The coating composition according to claim 1 or 2, wherein component (D) is an organic titanium compound.

6. The coating composition according to claim 1 or 2, further comprising an organic solvent having a boiling point of more than 130°C.

7. The coating composition according to claim 1 or 2, wherein the content of the component (D) is 0.1 to 20 parts by mass per 100 parts by mass of the component (A).

8. The coating composition according to claim 1 or 2, wherein component (C) comprises an acetic acid ester-based solvent and / or an aromatic hydrocarbon-based solvent.

9. A coating film formed from the coating composition according to claim 1 or 2.

10. An outdoor object on which the coating film according to claim 9 is formed.

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