JPH0925437A - Antimicrobial inorganic coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial coating material capable of sustaining an antimicrobial property for a long period and being baked at <=200 deg.C, and not requiring a treatment after its curing by drying, by blending the coating material having a specific composition with an antimicrobial agent and fine particles of a silica and/or an aluminum oxide. SOLUTION: This antimicrobial inorganic coating material is obtained by blending an inorganic coating material containing (A) (i) 20-200 pts.wt. silicon compound of the formula Si(OR<1> )4 (R<1> is a monovalent hydrocarbon) (e.g. teramethoxysilane) and/or a colloidal silica, (ii) 100 pts.wt. silicon compound of the formula R<2> Si(OR<1> )3 (R<2> is R<1> ) (e.g. methyltrimethoxysilane) and (iii) 0-60 pts.wt. silicon compound of the formula R<2> 2 Si(OR<1> )2 (e.g. dimethyldimethoxysilane) and having >=900 weight averaged molecular weight based on polystyrene, with (B) an antimicrobial agent (e.g.; a silver releasing- type antimicrobial agent) and (C) superfine particles of a silica and/or an aluminum oxide. To obtain the component A, e.g. the components (i) to (iii) are diluted with a solvent, then water is added as a curing agent, and hydrolysis and polycondensation reactions are performed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial inorganic coating material.

[0002]

2. Description of the Related Art In an antibacterial organic paint containing an antibacterial agent in an organic resin, the resin deteriorates when used for a long period of time. Especially when used outdoors, dirt adheres to the surface,
There is a disadvantage that the antimicrobial performance of the coating film is apt to decrease due to the deterioration due to ultraviolet rays. Therefore, inorganic coatings containing an antibacterial agent in a silicate-based, phosphate-based, zirconium-based inorganic composition are known, but the above-mentioned inorganic coatings have better durability than organic coatings. Since it is necessary to bake at a high temperature of 200 ° C. or more, the usable range is limited, and it is not suitable for directly applying to building materials and plastics. It should be noted that the silicate-based inorganic coating has a disadvantage that when used for a long period of time, the alkali is eluted to the surface and the efflorescence phenomenon easily occurs.

Further, in Japanese Patent Laid-Open No. 62-57470,
Although an inorganic coating material containing a metal alkoxide is disclosed, although this inorganic coating material cures at 200 ° C. or lower, it has a problem that the coating film is not flexible and cracks easily occur.
In recent years, due to the need to use paints for a wide variety of materials, antibacterial performance is maintained even when used for a long period of time, and there are no cracks, baking can be performed at temperatures of 200 ° C or less, and there is no need for treatment after curing and drying. There is a need for paints that can.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned facts, and an object thereof is to maintain antibacterial performance for a long period of time and enable baking at a temperature of 200 ° C. or lower, Another object of the present invention is to provide an antibacterial inorganic coating which can eliminate the need for treatment after curing and drying.

[0005]

The antibacterial inorganic coating material according to claim 1 of the present invention comprises an inorganic coating material having the following composition containing an antibacterial agent, and further, among ultrafine particle silica and ultrafine particle aluminum oxide, It is characterized by containing at least one kind.

The above-mentioned inorganic paint has the following general formula:
20 to 200 parts by weight of a silicon compound represented by R ¹ ) ₄ and / or colloidal silica, and (b) a general formula:
The silicon compound represented by R ² Si (OR ¹ ) ₃ is 100
Parts by weight, and (c) general formula: R ² ₂ Si (OR ¹ ) ₂
The weight average molecular weight of the inorganic coating material containing the silicon compound represented by the above in a proportion of 0 to 60 parts by weight and (d) containing these is 900 or more in terms of polystyrene. [The above R ¹ and R ² represent a monovalent hydrocarbon group. The antibacterial inorganic coating material according to claim 2 of the present invention is obtained by adding an antibacterial agent to an inorganic coating material having the following composition and further containing at least one kind of ultrafine particle silica and ultrafine particle aluminum oxide. Is characterized by.

The above inorganic coating composition comprises (a) 0.001 to 0.001 of water relative to 1 mol of X in colloidal silica in which a hydrolyzable organosilane represented by the following general formula [1] is dispersed in an organic solvent or water. A silica-dispersed oligomer solution of organosilane partially hydrolyzed under the condition of using 0.5 mol, and R ³ _n SiX _4-n [1] [wherein, R ³ is the same or different substituted or unsubstituted carbon The monovalent hydrocarbon groups of the numbers 1 to 8 are shown, n is an integer of 0 to 3, and X is a hydrolyzable group. (B) Polyorganosiloxane having a silanol group in the molecule represented by the following formula [2], and R ⁴ _a Si (OH) _b O _{(4-ab) / 2} [2] [In the formula, R ⁴ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a and b are 0.2 ≦ a ≦ 2 and 0.0001 ≦ b ≦, respectively. 3, a +
This is a number that satisfies the relationship of b <4. (C) a catalyst, and (D) the colloidal silica of the silica-dispersed oligomer solution contains 5 to 95% by weight of silica as a solid content, and at least 50 mol% of the hydrolyzable organosilane is contained in the above [ 1] In the formula, n is 1, and (e) the polyorganosiloxane is contained in an amount of 99 to 1 part by weight based on 1 to 99 parts by weight of the silica-dispersed oligomer solution.

An antibacterial inorganic coating material according to a third aspect of the present invention is characterized in that it contains a component having an elution type antibacterial performance as the antibacterial agent.

In the antibacterial inorganic coating material according to claim 4 of the present invention, the component having the elution-type antibacterial performance of claim 3 is silver,
It is characterized by being at least one selected from the group consisting of copper, zinc, nickel, palladium, platinum, gold, cadmium, mercury, cobalt and rhodium.

An antibacterial inorganic coating material according to a fifth aspect of the present invention is characterized by containing a component having a photocatalytic function as the antibacterial agent.

In the antibacterial inorganic paint according to claim 6 of the present invention, the component having a photocatalytic function according to claim 5 is titanium oxide, zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, or oxide. At least one selected from the group consisting of molybdenum, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, copper oxide, vanadium oxide, niobium oxide, tantalum oxide, manganese oxide, cobalt oxide, rhodium oxide, and rhenium oxide. Characterize.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The antibacterial inorganic coating material of the present invention contains an antibacterial agent in the inorganic coating material, and contains at least one of ultrafine particle silica and ultrafine particle aluminum oxide.

The inorganic coating material will be described. The inorganic paint of the antibacterial inorganic paint according to claim 1 of the present invention is a silicon compound represented by the following formula [3], and / or
20 to 200 parts by weight of colloidal silica, general formula: Si (OR ¹ ) ₄ [3] 100 parts by weight of a silicon compound represented by the following general formula [4], and general formula: R ² Si ( OR ¹ ) ₃ [4] A silicon compound represented by the following formula [5] is added in an amount of 0 to 60.
It is contained in a proportion of parts by weight. General _{^{formula: R 2 2 Si (OR 1}} ) 2 [5] The above R ^1, R ² represents a monovalent hydrocarbon group.

The above silicon compound has the following general formula [6]:
It is what is represented. R^Two _nSi (OR¹)_4-n [6] [n = 0 to 3, indicating R¹, R^TwoIs a monovalent hydrocarbon group
Show. ] R of the previous formula [6]¹, R^TwoIs a monovalent hydrocarbon group
Without limitation, R ^TwoAs C1-8 substitution or
Represents an unsubstituted hydrocarbon group, such as a methyl group or ethyl group.
, Propyl, butyl, pentyl, hexyl
Group, alkyl group such as heptyl group, octyl group, cyclopentyl group
Cycloalkyl groups such as ethyl and cyclohexyl groups, 2
-Ara such as phenylethyl group and 3-phenylpropyl group
Aryl group such as alkyl group, phenyl group and tolyl group, vinyl group
Group, alkenyl group such as allyl group, chloromethyl group, γ
-Chloropropyl group, 3,3,3-trifluoropropyl group, etc.
Halogen-substituted hydrocarbon group and γ-methacryloxy
Propyl group, γ-glycidoxypropyl group, 3,4-E
Poxycyclohexylethyl group, γ-mercaptopropy
And a substituted hydrocarbon group such as a rutile group. Above all synthetic
Because of its ease or availability, it has 1 to 4 carbon atoms.
A kill group and a phenyl group are preferred.

As R ¹ in the above formula [6], ^one having an alkyl group having 1 to 4 carbon atoms as a main raw material is used. In particular, n = 0
Examples of the tetraalkoxysilane include tetramethoxysilane and tetraethoxysilane, and examples of the organotrialkoxysilane having n = 1 include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, and phenyltrimethoxysilane. Phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Further, n = 2
Examples of diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane. Examples of triorganoalkoxysilanes with n = 3 include trimethylmethoxysilane. , Trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane and the like.

The above R ¹ and R ² are represented by the above formulas [3], [4],
In [5], the same hydrocarbon group may be present or different.

The above-mentioned inorganic coating is prepared by, for example, diluting the silicon compound represented by the above formulas [3], [4] and [5] with a solvent, adding water or a catalyst as a curing agent, and hydrolyzing the compound. Also, it is prepared by performing a polycondensation reaction. The weight average molecular weight (Mw) of these silicon compounds is calculated in terms of polystyrene. In this preparation, the weight average molecular weight (Mw) of the inorganic coating is adjusted to 900 or more in terms of polystyrene. When the weight average molecular weight (Mw) is less than 900 in terms of polystyrene, the curing shrinkage becomes large during the polycondensation reaction, and cracks are easily generated in the baked inorganic paint film.

The above-mentioned inorganic coating material can be used in combination with the silicon compound represented by the above formula [3], or alternatively, can contain colloidal silica as a component. The colloidal silica,
It is a water-dispersible colloidal silica dispersed in water or an organic solvent-dispersible colloidal silica dispersed in a non-aqueous organic solvent such as alcohol. The colloidal silica contains 20 to 50% by weight of silica as a solid content.
In the preparation of the inorganic coating material, the water-dispersible colloidal silica can use water existing as a component other than the solid content as a curing agent. Further, the organic solvent-dispersible colloidal silica can be easily prepared by substituting water for the organic solvent. Examples of the organic solvent in which the colloidal silica is dispersed include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. And derivatives of diethylene glycol such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, in combination with a hydrophilic organic solvent, toluene, xylene, ethyl acetate, butyl acetate,
Methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime and the like can also be used. The amount of the colloidal silica is a weight including the dispersion medium.

Water is generally used as a curing agent when preparing an inorganic coating, and the amount of this water is preferably 45% or less, more preferably 25% or less in the inorganic coating.

The organic solvent used for producing the inorganic coating is, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoacetate. Examples thereof include ethylene glycol derivatives such as ethyl ether, diethylene glycol, diethylene glycol derivatives such as diethylene glycol monobutyl ether, and diacetone alcohol. One or two of these may be mentioned.
More than one species is used. Further, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime and the like can be used in combination with a hydrophilic organic solvent.

When preparing the above-mentioned inorganic paint, p of the inorganic paint is used.
It is desirable for H to be 3.8-6. When the pH is within this range, the preservability of the inorganic coating is good, and when the pH is outside the pH range, the application period from the preparation period is limited. The method of adjusting the pH is not limited. For example, when the pH is less than 3.8 when the materials are mixed, the pH may be adjusted by adding a basic reagent such as ammonia, and the pH exceeds 6. In this case, it may be adjusted by adding an acidic reagent such as hydrochloric acid.
In addition, depending on the pH, when the reaction progresses slowly in a state where the molecular weight is small, heating may be used to accelerate the reaction,
After the reaction is advanced by lowering the pH with an acidic reagent, a basic reagent may be added to adjust the pH to a predetermined value.

Next, the inorganic coating material of the antibacterial inorganic coating material according to claim 2 of the present invention will be described. This inorganic coating material comprises a colloidal silica in which a hydrolyzable organosilane represented by the following general formula [1] is dispersed in an organic solvent or water,
A silica-dispersed oligomer solution of organosilane partially hydrolyzed under the condition of using 0.001 to 0.5 mol of water per 1 mol of X, and a general formula: R ³ _n SiX _4-n [1] ³ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, n represents an integer of 0 to 3, and X represents a hydrolyzable group. ] A polyorganosiloxane having a silanol group in the molecule whose average composition formula is represented by the following formula [2], and an average composition formula: R ⁴ _a Si (OH) _b O _{(4-ab) / 2} [2 [Wherein, R ⁴ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a and b are 0.2 ≦ a ≦ 2 and 0.0001 ≦ b, respectively. ≦ 3, a +
This is a number that satisfies the relationship of b <4. ] It consists of a catalyst. Further, in the above inorganic coating material, the silica dispersion oligomer solution contains 5 to 95% by weight of silica as a solid content, and at least 50 mol% of the hydrolyzable organosilane is contained in the organosilane of formula [1] where n is 1. And 1 to 99 parts by weight of the silica dispersion oligomer solution,
It contains 99 to 1 part by weight of the above polyorganosiloxane.

The silica-dispersed oligomer of the above-mentioned silica-dispersed oligomer solution is the main component of the base polymer having a hydrolyzable group as a functional group involved in the curing reaction when forming a coating film. This silica-dispersed oligomer is an organic solvent,
Alternatively, the colloidal silica dispersed in water may be added to the above formula [1]
It is obtained by partially hydrolyzing the hydrolyzable organosilane with water in colloidal silica or water added separately, by adding one or more hydrolyzable organosilanes represented by

R ³ of the hydrolyzable organosilane represented by the above formula [1] is a substituted or unsubstituted 1 having 1 to 8 carbon atoms.
And a valent hydrocarbon group. Specific examples include the same hydrocarbon groups as those described above for R ² .

Examples of X representing the hydrolyzable group include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group and an amide group. Among these, an alkoxy group is preferred because of its availability and ease of preparation of the silica-dispersed oligomer solution.

Such a hydrolyzable organosilane is
Mono-, di-, tri-, and tetra-functional alkoxysilanes, acetoxysilanes, oxime silanes, and enoxysilanes, wherein n in the chemical formula represented by the formula (1) is an integer of 0 to 3. , Aminosilanes, aminoxysilanes, amidosilanes and the like. Among these, alkoxysilanes are preferred because of their availability and ease of preparation of the silica-dispersed oligomer solution. Examples of the tetraalkoxysilane with n = 0 include tetramethoxysilane and tetraethoxysilane,
Examples of the organotrialkoxysilane having n = 1 include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane. Is exemplified. Further, as the diorganodialkoxysilane of n = 2,
Dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, etc. are exemplified.
Examples include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane, and the like. Further, an organosilane compound generally called a silane coupling agent is also included in the alkoxysilanes.

It is necessary that at least 50 mol% of the above hydrolyzable organosilane is a trifunctional organosilane represented by the formula [1] where n is 1. The proportion of the trifunctional organosilane is preferably at least 60 mol%, more preferably at least 70 mol%. If the content is less than 50 mol%, sufficient coating film hardness cannot be obtained, and dry curability tends to be poor.

The colloidal silica in which the above hydrolyzable organosilane is dispersed in an organic solvent or water enhances the hardness of the cured coating film of the inorganic coating material. Examples of the colloidal silica include the water-dispersible colloidal silica and the organic solvent-dispersible colloidal silica described in the inorganic coating material according to claim 1.

The colloidal silica contains silica in a solid content of 5 to 95% by weight. This content is 1
The content is preferably 0 to 90% by weight, more preferably 20 to 85% by weight.
% By weight. If the content is less than 5% by weight, the hardness of the coating film of the inorganic coating cannot be obtained, and if the content exceeds 95% by weight, uniform dispersion of silica becomes difficult, and problems such as easy gelation occur. Cheap.

The hydrolyzable organosilane represented by the above formula [1] is partially hydrolyzed in an organic solvent or colloidal silica dispersed in water to obtain a silica-dispersed oligomer solution of organosilane. The amount of water relative to the hydrolyzable organosilane was 0.
001 to 0.5 mol is preferable. If the amount of water is less than 0.001 mol, sufficient partial hydrolysis cannot be obtained, and if it exceeds 0.5 mol, the stability of the partial hydrolyzate deteriorates. The method for the partial hydrolysis is not particularly limited, and the hydrolyzable organosilane and colloidal silica may be mixed and predetermined water may be added. At this time, the partial hydrolysis reaction proceeds at room temperature. In addition, you may heat at 60-100 degreeC in order to accelerate | stimulate the said partial hydrolysis reaction. Further, for the purpose of promoting partial hydrolysis reaction, hydrochloric acid, acetic acid, halogenated silane, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, Organic and inorganic acids such as toluene sulfonic acid and oxalic acid may be used as catalysts.

In order to obtain stable performance of the silica-dispersed oligomer solution for a long period of time, the pH of the solution is 2.0 to 7.0,
Preferably the pH is between 2.5 and 6.5, more preferably the pH
Is preferably set to 3.0 to 6.0. When the pH is out of this range, the long-term performance of the silica-dispersed oligomer solution is remarkably reduced particularly when the amount of water is 0.3 mol or more per 1 mol of the hydrolyzable group (X). The method of adjusting the pH is not limited, but when the pH of the solution is out of the above range, the pH may be adjusted by adding a basic reagent such as ammonia or ethylenediamine. ,
It may be adjusted by adding an acidic reagent such as nitric acid or acetic acid.

The silanol group-containing polyorganosiloxane of the above-mentioned inorganic paint has an average compositional formula represented by the above formula [2].

R ⁴ in the above formula [2] represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and specific examples thereof include the same hydrocarbon group as R ² described above. However, preferably, an alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, γ-aminopropyl group, 3,3,3-trifluoro group It is a substituted hydrocarbon group such as a propyl group, more preferably a methyl group and a phenyl group. A and b in the above formula [2] are 0.2 ≦ a ≦ 2 and 0.0001, respectively.
≦ b ≦ 3, a + b <4. When a is less than 0.2 or b exceeds 3, there are disadvantages such as generation of cracks in the cured coating film, and when a is more than 2.0 and 4 or less or when b is less than 0.0001, curing proceeds well. do not do.

As the polyorganosiloxane containing a silanol group, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or a mixture of two or more alkoxysilanes corresponding thereto is known. It can be obtained by hydrolysis with a large amount of water according to the method.
To obtain the polyorganosiloxane containing the silanol group, when hydrolyzed using alkoxysilane,
A small amount of unhydrolyzed alkoxy groups may remain. In other words, a polyorganosiloxane in which a silanol group and a trace amount of an alkoxy group coexist may be obtained, but such a polyorganosiloxane may be used.

The above catalyst accelerates the condensation reaction between the above-mentioned silica-dispersed oligomer solution and polyorganosiloxane,
It cures the coating film. Examples of the catalyst include alkyl titanates, metal salts of carboxylic acids such as tin octylate and dibutyltin dilaurate, dioctyltin dimaleate, amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Quaternary ammonium salts of carboxylic acids such as tetramethylammonium acetate, amines such as tetraethylpentamine, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyldimethoxy Amine silane coupling agents such as silane, acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as sodium hydroxide; tetraisopropyl titane , Tetrabutyl titanate, titanium compounds such as titanium tetraacetyl acetonate, methyltrichlorosilane, dimethyldichlorosilane, halogenated silane such as trimethyl monochloro silane, and the like.

The compounding ratio of the silica-dispersed oligomer solution to the polyorganosiloxane is 1 to 99 parts by weight of the silica-dispersed oligomer solution and 99 to 1 parts by weight of the polyorganosiloxane, preferably the silica. The dispersion oligomer solution is 5 to 95 parts by weight, and the polyorganosiloxane is 95 to 5 parts by weight, and more preferably, the silica dispersion oligomer solution is 10 to 9 parts by weight.
90 parts by weight of the polyorganosiloxane is 90 to 90 parts by weight.
10 parts by weight. If the proportion of the silica-dispersed oligomer solution is less than the above range, it is difficult to cure at room temperature, and a sufficient hardness of the coating film cannot be obtained. If the ratio of the silica-dispersed oligomer solution is more than the above range, the curability becomes unstable.

The content of the catalyst is preferably 0.0001 to 10 parts by weight based on 100 parts by weight of the total amount of the silica-dispersed oligomer solution and the polyorganosiloxane. It is more preferably 0.0005 to 8 parts by weight, most preferably 0.0007 to 5 parts by weight. 0.00 catalyst
If it is less than 01 parts by weight, it will not cure at room temperature, and if it exceeds 10 parts by weight, heat resistance and weather resistance will deteriorate.

The hydrolyzable group contained in the silica-dispersed oligomer and the silanol group in the polyorganosiloxane are subjected to a condensation reaction in the presence of a catalyst at room temperature or at a low temperature of 200 ° C. or lower to form a coating film. To do. Accordingly, the inorganic coating cures at room temperature with little effect from humidity. Further, the condensation reaction can be promoted by the low-temperature heating.

The above-mentioned inorganic paint can be diluted with various organic solvents for easy handling. The type of the organic solvent is appropriately selected depending on the type and molecular weight of the monovalent hydrocarbon group in the silica-dispersed oligomer solution and the polyorganosiloxane. Examples of the organic solvent include the same organic solvents as described in the inorganic coating according to the first aspect.

Further, claim 1 or claim 2 of the present invention.
The inorganic paint of the antibacterial inorganic paint according to
At least one kind of ultrafine aluminum oxide is contained.

The average diameter of the primary particles of the ultrafine silica particles is 3 nm to 50 nm, and particularly 3 nm to 1 nm.
It is preferably 2 nm. The average diameter of the primary particles of ultrafine aluminum oxide is 3n.
It is preferably m to 50 nm, and particularly preferably 5 nm to 20 nm. The ultrafine silica particles and the ultrafine aluminum oxide particles may be used alone or in combination.

By containing at least one of the ultrafine particle silica and the ultrafine particle aluminum oxide, it is adsorbed around the antibacterial agent which is a large particle in the inorganic paint, and the viscosity of the antibacterial agent varies depending on the adsorbed state. It has a high chain shape. Then, aggregation of the antibacterial agents is prevented and the antibacterial agent is prevented from settling due to the chain-like shape having high viscosity. That is, it becomes a stable matrix, and the antibacterial agent is prevented from settling in the inorganic paint and during the coating of the coating film, and the surface exposure rate of the antibacterial agent is increased, which impairs the weather resistance and the transparency of the coating film. It is possible to form a coating film having a high antibacterial action.

In both of the ultrafine silica particles and the ultrafine aluminum oxide particles, when the average diameter of the primary particles is less than 3 nm, the ultrafine oxide particles are agglomerated so much that the coating film produced becomes opaque. It's not good to be.
On the other hand, when the average diameter of the primary particles of both ultrafine silica particles and ultrafine aluminum oxide particles exceeds 50 nm, turbidity due to the presence of the particles causes opacity in the coating film formed in this case as well. It ’s not good.

The ultrafine particles of silica and the ultrafine particles of aluminum oxide may be used alone or in combination. As ultrafine particles of oxide, 5 wt% or more, preferably 10 wt% or more is added to the total amount of the final preparation liquid. There is a need to.
The ultrafine particle oxide is not particularly limited in its manufacturing method and surface treatment method.

The ultrafine particle silica and the ultrafine particle aluminum oxide may be in the form of powder or may be in the state of being dispersed in a solvent, and are not particularly limited. As a method of adding the ultrafine particle silica and the ultrafine particle aluminum oxide, various dispersers such as a dissolver, a bead mill, a roll mill and a ball mill can be used after mixing with the antibacterial inorganic coating material.

Next, the antibacterial agent contained in the antibacterial inorganic coating material of the present invention will be explained. As the above-mentioned antibacterial agent, various antibacterial agents such as one containing a component having an elution type antibacterial property and one containing a component having a photocatalytic function are appropriately selected. Examples of the component having an elution type antibacterial property contained in the above antibacterial agent include silver, copper, zinc, nickel, palladium, platinum, gold, cadmium, mercury, cobalt, rhodium and the like. Furthermore, as an antibacterial agent,
For example, quaternary ammonium salts, organic halogen-containing compounds, chlorine-containing compounds, iodine compounds and the like can be mentioned. These inorganic paints contain these alone or in combination of two or more. Further, the above component is zeolite or activated alumina,
It may be dispersed in a porous material such as silica gel and supported, provided that it does not impair the function and weather resistance of the inorganic coating material.

Examples of the photocatalytic component contained in the above antibacterial agent include titanium oxide, zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, and oxide. Examples thereof include lead, cadmium oxide, copper oxide, vanadium oxide, niobium oxide, tantalum oxide, manganese oxide, cobalt oxide, rhodium oxide, rhenium oxide, and one of these or a mixture of two or more thereof. The component having the photocatalytic function is mixed into the inorganic paint as long as the function and weather resistance of the inorganic paint are not impaired.

Further, the antibacterial inorganic coating material may contain an antibacterial agent in a state where a metal is supported on the component having the photocatalytic function. Examples of the metal include silver, copper, iron, nickel, zinc, platinum, gold, palladium, cadmium, cobalt, rhodium, and ruthenium, or a mixture of two or more thereof. When a metal is supported on a component having a photocatalytic function, charge separation is promoted, and the photocatalyst is activated. It is preferable that the carried metal has antibacterial properties, because the antibacterial properties are further improved.

Further, the antibacterial inorganic coating material may contain, as an antibacterial agent, a clay mineral in which an oxide having a photocatalytic function is inserted between layers. As the clay mineral, a smectite-type mineral having swellability is suitable. The smectite-type mineral may be natural or synthetic. The oxide inserted into the clay mineral is titanium oxide, zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, copper oxide, At least one of vanadium oxide, niobium oxide, tantalum oxide, manganese oxide, cobalt oxide, rhodium oxide, rhenium oxide, and the like is given. When an oxide is inserted between layers of the clay mineral, the oxide is retained by the fine particles, exhibits high photocatalytic activity, and improves antibacterial properties. Further, a metal may be supported on an oxide having a photocatalytic function inserted between layers. As the above metal,
For example, silver, copper, iron, nickel, zinc, platinum, gold, palladium, cadmium, cobalt, rhodium, ruthenium alone or a mixture of two or more thereof can be mentioned. When a metal is carried on an oxide having a photocatalytic function, charge separation is promoted and the photocatalyst is activated, so that antibacterial properties are improved, which is preferable. It is preferable that the carried metal has antibacterial properties, because the antibacterial properties are further improved.

In the case of producing an antibacterial inorganic coating material, the antibacterial agent containing the photocatalytic function and the oxide is used as the antibacterial agent containing the photocatalytic function and the oxide dispersed in a solvent or powder. Used in. The powder is obtained by drying such as heat drying, freeze drying, and supercritical drying.

The antibacterial inorganic paint is applied by brushing,
Various coating methods such as spray coating, dipping, curtain, and knife coating can be adopted. At the time of application, it may be appropriately diluted with an organic solvent as needed.

As a method of treating a coating film coated with an antibacterial inorganic coating, depending on the type and content of the above-mentioned antibacterial agent, the silicone component in the inorganic coating wraps the antibacterial agent component when the coating film is formed. Since the properties may not be sufficiently exhibited, it is preferable to treat the surface of the coated and dried coating film with acid or alkali. When the surface of the coating film is treated with an acid or an alkali, the silicone component is eluted and the antibacterial agent is exposed on the surface, so that the antibacterial property is improved. The types of the acids and alkalis and the states of liquids and gases are not particularly limited, but in the case of weak acids and weak alkalis, it is necessary to take a long treatment time. The treatment method may be immersion in a solution or treatment in a gas phase by placing an article to be coated in a chamber.

[0054]

Next, examples of the present invention and comparative examples will be described. The molecular weight is a value determined by gel permeation chromatography (GPC) using a measurement model HLC8020 (manufactured by Tosoh Corporation) and obtained from a calibration curve of standard polystyrene.

Example 1 Tetraethoxysilane as the silicon compound represented by the above formula [3] and IPA organosilica sol as the colloidal silica (Catalyst Kasei Co., Ltd .: trade name OSCAL14)
32), methyltrimethoxysilane as the silicon compound represented by the above formula [4], dimethyldimethoxysilane as the silicon compound represented by the above formula [5], and a silver-eluting antibacterial agent as the antibacterial agent (Kinki Pulp Giken Co., Ltd.). Made: Biosure, trade name; and ultrafine silica (Cabosil: trade name TS720, average primary particle diameter: 1)
2 nm) was added.

To 100 parts by weight of methyltrimethoxysilane (hereinafter referred to as "part"), 10 parts of tetraethoxysilane,
90 parts of IPA organosilica sol, 30 parts of dimethyldimethoxysilane, isopropyl alcohol (IPA)
Was mixed, and 90 parts of water was added, followed by stirring. This was adjusted to a weight average molecular weight (hereinafter referred to as Mw) of 1500 in a thermostat at 60 ° C. This prepared liquid 1
15 parts of ultrafine silica in 6 parts, 6 parts of silver-eluting antibacterial agent,
Add 100 parts of glass beads, put in a simple sealed glass bottle, and disperse with a paint shaker for 1 hour.
The glass beads were filtered to obtain an antibacterial inorganic paint.

The obtained antibacterial inorganic coating material was applied to an alumina substrate washed with acetone and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the cured coating film was 10 μm.

Example 2 IPA organosilica sol (Catalyst Kasei Co., Ltd .: trade name OSCAL1432) as colloidal silica, methyltrimethoxysilane as the silicon compound represented by the above formula [4], and a silver-eluting antibacterial agent as the antibacterial agent. (Kinki Pulp Giken Co., Ltd .: trade name BioSure), and further ultrafine silica (Nippon Aerosil Co .: trade name AE)
ROSIL 300, average diameter of primary particles: 7 nm, and ultrafine aluminum oxide (manufactured by Nippon Aerosil Co., Ltd .: trade name A)
Luminium Oxide C, average diameter of primary particles: 13 nm) was added.

To 100 parts by weight of methyltrimethoxysilane (hereinafter referred to as "part"), 60 parts of IPA organosilica sol was added.
Parts and 100 parts of isopropyl alcohol (IPA) were mixed, and then 60 parts of water was added and stirred. This is 60
Weight average molecular weight (hereinafter referred to as Mw) in a constant temperature bath at ℃ 9
It was adjusted to 50. To 100 parts of this prepared liquid, 10 parts of ultrafine silica, 5 parts of ultrafine aluminum oxide, 6 parts of silver-eluting antibacterial agent, and 100 parts of glass beads were added, put in a simple sealed glass bottle, and a paint shaker for 1 hour. After the dispersion, the glass beads were filtered to obtain an antibacterial inorganic paint.

The obtained antibacterial inorganic coating material was applied to an alumina substrate washed with acetone in the same manner as in Example 1 and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

Example 3 Instead of the silver-eluting antibacterial agent of Example 2, titanium oxide powder (manufactured by Nippon Aerosil Co., Ltd .: trade name P-2) was used as an antibacterial agent.
An antibacterial inorganic coating material was obtained in the same manner as in Example 2 except that 5) was used.

The antibacterial inorganic coating material obtained was applied to an alumina substrate washed with acetone in the same manner as in Example 1 and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

Next, (A-1 solution) and (A-2 solution) were prepared as silica-dispersed oligomer solutions, and (B-1 solution) and (B-2 solution) were prepared as polyorganosiloxane.

(Liquid A-1) Methanol-dispersed colloidal silica sol MT-ST (particle size 1) was placed in a flask equipped with a stirrer, a heating jacket, a condenser, and a thermometer.
0 to 20 mμ, solid content 30%, water 0.5%, manufactured by Nissan Chemical Industries, Ltd.) 100 parts, methyltrimethoxysilane 68 parts, water 10.8 parts, and stirred, 65 ° C.
Partially hydrolyzed for 5 hours and cooled. Thereafter, when left at room temperature for 48 hours, the solid content was 36%.
Hereinafter, this silica-dispersed oligomer solution is referred to as (A-1 solution).

The number of moles of water relative to 1 mol of the hydrolyzable group was 0.4 mole, the content of silica in (A-1 solution) was 47.3%, and n = 1 was added. The mol% of the decomposable group-containing organosilane was 100 mol%.

(Liquid A-2) Methanol-dispersed colloidal silica sol MT-ST (particle size: 1) was placed in a flask equipped with a stirrer, a heating jacket, a condenser, and a thermometer.
0-20 mμ, solid content 30%, water 0.5%, manufactured by Nissan Chemical Industries, Ltd.) 100 parts, methyltrimethoxysilane 68 parts, dimethyldimethoxysilane 18 parts, water 2.7 parts, acetic anhydride Add 0.1 part of and stir for 8
Partially hydrolyzed at 0 ° C. for 3 hours and cooled. Thereafter, when left at room temperature for 48 hours, the solid content was 36%. Hereinafter, this silica-dispersed oligomer solution (A-2
Liquid).

The number of moles of water relative to 1 mol of the hydrolyzable group was 0.1 mole, the content of silica in (A-2 solution) was 40.2%, and n = 1. The mol% of the decomposable group-containing organosilane was 77 mol%.

(B-1 Solution) A mixed solution of 220 parts (1 mol) of methyltriisopropoxysilane and 160 parts of toluene was prepared. Next, the mixture was placed in a flask equipped with a stirrer, a heating jacket, a condenser, a dropping funnel, and a thermometer, and 108 parts of a 1% aqueous hydrochloric acid solution was added dropwise over 20 minutes, and methyltriisopropoxysilane was added. Hydrolyzed. After 40 minutes from the dropping, stirring was stopped and the mixture was allowed to stand to separate into two layers. Of this layer, the lower layer of a mixture of water and isopropyl alcohol containing a small amount of hydrochloric acid was separated and removed, then hydrochloric acid was washed off from the remaining toluene resin solution, and toluene was further removed under reduced pressure. By diluting the mixture with isopropyl alcohol, a solution of a silanol-containing polyorganosiloxane having an average molecular weight of about 2000 and 40% isopropyl alcohol was obtained. Less than,
This solution is referred to as (B-1 solution).

(Liquid B-2) 1000 parts of water and 50 parts of acetone were put into a flask equipped with a stirrer, a heating jacket, a condenser, a dropping funnel and a thermometer, and 44.8 parts of methyltrichlorosilane (0. 3 mol), 38.7 parts (0.3 mol) of dimethyldichlorosilane, and 84.6 parts (0.4 mol) of phenyltrichlorosilane dissolved in 200 parts of toluene were added dropwise with stirring to be hydrolyzed. . After 40 minutes from the addition, the stirring was stopped, and the reaction solution was transferred to a separating funnel and allowed to stand. In this layer, the hydrochloric acid aqueous solution in the lower layer was separated and removed, and the remaining toluene solution of the polyorganosiloxane was removed by vacuum stripping to remove the remaining water and hydrochloric acid together with the toluene, thereby obtaining an average molecular weight of about 3,000. A 60% toluene solution of a polyorganosiloxane containing silanol groups was obtained. Hereinafter, this solution is referred to as (solution B-2).

Example 4 After mixing 100 parts of the prepared solution A-1 with 100 parts of solution B-2 and 4 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane as a catalyst, an antibacterial agent was prepared. 30 parts of titanium oxide powder having a photocatalytic function (Nippon Aerosil Co., Ltd .: trade name P-25), 20 parts of ultrafine silica particles, 8 parts of ultrafine aluminum oxide particles, 200 parts of glass beads were added, and a simple sealed type was added. After being placed in a glass bottle of No. 1 and dispersed by a paint shaker for 1 hour, the glass beads were filtered to obtain an antibacterial inorganic paint.

The obtained antibacterial inorganic coating material was applied to an alumina substrate washed with acetone in the same manner as in Example 1 and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

Example 5 100 parts of the prepared liquid A-2, 100 parts of the liquid B-1 and 4 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane as a catalyst were mixed, and then mixed as an antibacterial agent. 18 parts silver-eluting antibacterial agent (Kinki Pulp Giken Co., Ltd .: trade name BioSure), 20 parts ultrafine silica, 8 parts ultrafine aluminum oxide, 200 glass beads
Part of the mixture was added, placed in a simple closed glass bottle, dispersed for 1 hour with a paint shaker, and then the glass beads were filtered to obtain an antibacterial inorganic paint.

The obtained antibacterial inorganic coating material was applied to an alumina substrate washed with acetone in the same manner as in Example 1 and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

Comparative Example 1 100 parts of methyltrimethoxysilane, 60 parts of IPA organosilica sol, and isopropyl alcohol (IP
After mixing 100 parts of A), 60 parts of water was added and stirred. This was adjusted to have a weight average molecular weight (hereinafter referred to as Mw) of 950 in a constant temperature bath of 60 ° C. This prepared liquid 1
Silver-eluting antibacterial agent in 00 parts (Kinki Pulp Giken Co., Ltd .:
Trade name BioSure) 10 parts, glass beads 100
Part of the mixture was added, placed in a simple closed glass bottle, dispersed for 1 hour with a paint shaker, and then the glass beads were filtered to obtain an antibacterial inorganic paint.

The antibacterial inorganic coating material obtained was applied to an alumina substrate washed with acetone in the same manner as in Example 1, and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

Comparative Example 2 100 parts of the prepared solution A-1 and 100 parts of solution B-2 were mixed with 4 parts of N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane as a catalyst, and then used as an antibacterial agent. Add 20 parts of silver-eluting antibacterial agent (Kinki Pulp Giken Co., Ltd .: trade name Biosure), add 200 parts of glass beads, put in a simple sealed glass bottle, disperse for 1 hour with a paint shaker, then glass beads Was filtered to obtain an antibacterial inorganic coating.

The obtained antibacterial inorganic coating material was applied to an alumina substrate washed with acetone in the same manner as in Example 1 and dried at a temperature of 150 ° C. for 1 hour. The film thickness of the coating film after curing is 10
μm.

The antibacterial properties of the coating films applied to the alumina substrates of Examples 1 to 5 and Comparative Examples 1 and 2 were evaluated. For the evaluation, a solution containing a certain number of bacteria was dropped on an alumina substrate with a coating by a drop method, and the change in the number of bacteria at the initial stage and after 6 hours was measured. E. coli is used as the bacterium, and the measurement is 3500
It went under the illuminance of Lux. The results are shown in Table 1. In addition, <10 shown in Table 1 indicates that the number of bacteria is “less than 10”.

From these results, the antibacterial effect was good in all the examples. Further, all of the antibacterial inorganic coating materials of the examples could be baked at a temperature of 200 ° C. or lower after coating, and the coating film was not cracked.

[0080]

[Table 1]

[0081]

The antibacterial inorganic coating composition of the present invention maintains antibacterial performance for a long period of time, can be baked at a temperature of 200 ° C. or lower, and has no cracks in the coating film due to its flexibility. In addition, the post-treatment after baking is unnecessary, and it is transparent and has high antibacterial performance.

Further, claim 5 or claim 6 of the present invention.
Since the antibacterial inorganic coating material described above contains a component having a photocatalytic function in the antibacterial agent, the oxygen permeability of the inorganic coating material enhances the antibacterial property, so that the antibacterial inorganic coating material has higher antibacterial performance.

Claims (6)

[Claims] 1. An antibacterial inorganic coating material comprising an inorganic coating material having the following composition containing an antibacterial agent, and further containing at least one of ultrafine particle silica and ultrafine particle aluminum oxide. The inorganic coating composition comprises (a) 20 to 200 parts by weight of a silicon compound represented by the general formula: Si (OR ¹ ) ₄ and / or colloidal silica.
(B) 100 parts by weight of a silicon compound represented by the general formula: R ² Si (OR ¹ ) ₃ , and (c) a general formula: R ² ₂ S
The weight average molecular weight of the inorganic coating material containing the silicon compound represented by i (OR ¹ ) ₂ in the proportion of 0 to 60 parts by weight and (d) containing these is 900 or more in terms of polystyrene. [The above R ¹ and R ² represent a monovalent hydrocarbon group. ] 2. An antibacterial inorganic paint comprising an inorganic paint of the following composition containing an antibacterial agent and further containing at least one of ultrafine silica and ultrafine aluminum oxide. The above-mentioned inorganic coating material is (a) X in a colloidal silica in which a hydrolyzable organosilane represented by the following general formula [1] is dispersed in an organic solvent or water.
A silica-dispersed oligomer solution of organosilane partially hydrolyzed under the condition of using 0.001 to 0.5 mol of water per 1 mol, and R ³ _n SiX _4-n [1] [wherein R ³ is the same. Alternatively, it represents a different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, n is an integer of 0 to 3, and X is a hydrolyzable group. (B) Polyorganosiloxane having a silanol group in the molecule represented by the following formula [2], and R ⁴ _a Si (OH) _b O _{(4-ab) / 2} [2] [In the formula, R ⁴ represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a and b are 0.2 ≦ a ≦ 2 and 0.0001 ≦ b ≦, respectively. 3, a +
This is a number that satisfies the relationship of b <4. (C) a catalyst, and (D) the colloidal silica of the silica-dispersed oligomer solution contains 5 to 95% by weight of silica as a solid content, and at least 50 mol% of the hydrolyzable organosilane is contained in the above [ 1] In the formula, n is 1, and (e) the polyorganosiloxane is contained in an amount of 99 to 1 part by weight based on 1 to 99 parts by weight of the silica-dispersed oligomer solution. 3. The antibacterial inorganic coating material according to claim 1 or 2, wherein the antibacterial agent contains a component having an elution type antibacterial performance. 4. The component having the elution-type antibacterial performance according to claim 3 is silver, copper, zinc, nickel, palladium, platinum,
The antibacterial inorganic coating material according to claim 3, which is at least one selected from the group consisting of gold, cadmium, mercury, cobalt, and rhodium. 5. The antibacterial agent contains a component having a photocatalytic function, as claimed in any one of claims 1 to 4.
Any of the antibacterial inorganic paints. 6. The component having a photocatalytic function according to claim 5,
Titanium oxide, zinc oxide, tin oxide, iron oxide, zirconium oxide, tungsten oxide, chromium oxide, molybdenum oxide, ruthenium oxide, germanium oxide, lead oxide, cadmium oxide, copper oxide, vanadium oxide, niobium oxide, tantalum oxide, manganese oxide. , At least one selected from the group consisting of cobalt oxide, rhodium oxide, and rhenium oxide.
The antibacterial inorganic coating material according to claim 5, which is a seed.