JP2008006420A - Method for coating cement-based decorative board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for coating a cement-based decorative board, in which the deterioration of an organic coating film can be prevented, a photocatalyst-containing inorganic coating film can exhibit a photocatalytic function satisfactorily and a dryer for drying a photocatalyst-containing inorganic coating material is not required. <P>SOLUTION: The method for coating the cement-based decorative board comprises the steps of applying an organic coating material, an inorganic coating material and the photocatalyst-containing inorganic coating material in this order to the surface of a cement-based board. After the inorganic coating material is applied, the applied inorganic coating material is dried under such a temperature condition that the temperature of the cement-based board is 60-120°C and under such a temporal condition that the baking energy being a product obtained by multiplying the temperature by the time is ≥5,000°C sec. After that, the photocatalyst-containing inorganic coating material is applied to the cement-based board of ≥80°C, so that the applied photocatalyst-containing inorganic coating material can be dried without being heated to dry the applied photocatalyst-containing inorganic coating material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for coating a cement-type decorative board used as an exterior material of a house.

  The surface of the cementitious board 1 used as an outer wall material or the like is colored for cosmetic purposes. This colored coating is usually carried out by applying an organic paint containing a pigment or the like to form the organic coating film 2, but since this organic coating film 2 is organic, it deteriorates due to the action of ultraviolet rays. Fading easily occurs.

  Therefore, as shown in FIG. 1, in order to protect the organic coating film 2 for makeup, an inorganic coating film 3 is formed by applying a silicone-based inorganic paint as a clear topcoat. Since the inorganic coating film 3 is inorganic, the organic coating film 2 can be protected from ultraviolet rays because the inorganic coating film 3 is hardly deteriorated against ultraviolet rays and hardly transmits ultraviolet rays. In particular, the organic coating film 2 can be more effectively protected by blending an ultraviolet absorber to make the inorganic coating film 3 have an ultraviolet cutting property (see, for example, Patent Document 1).

  Recently, a photocatalyst-containing inorganic coating film 4 is formed by coating a silicone-based inorganic paint containing a photocatalyst on the clear inorganic coating film 3. The photocatalyst is activated by the irradiation of ultraviolet rays and can decompose dirt adhering to the surface. Moreover, in order to make the surface hydrophilic, the decomposed dirt can be washed away with rain water, etc., and a self-cleaning effect is obtained. (See, for example, Patent Document 2).

As described above, when the organic coating film 2, the inorganic coating film 3, and the photocatalyst-containing inorganic coating film 4 are applied to the surface of the cement-based plate 1, first, preheating drying, application of a sealer paint, and sealer paint are performed as necessary. After drying and applying a sealer, the cement-based board 1 is preheated by passing through a preheater before organic coating, and then passed through an organic paint coating machine to apply organic paint, and then passed through an organic paint dryer. The organic coating film 2 is formed by drying. Next, the cement-based board 1 is preheated by passing through a preheater before inorganic coating, and then passed through an inorganic paint coater to apply an inorganic paint, followed by drying through an inorganic paint dryer, thereby forming an inorganic coating film. 3 is formed. Next, the cement-based plate 1 is preheated by passing through a preheater containing a photocatalyst containing inorganic coating, and then applied through a photocatalyst containing inorganic paint coater to apply the photocatalyst containing inorganic paint, and then passed through a photocatalyst containing inorganic paint dryer. And drying, the photocatalyst-containing inorganic coating film 4 is formed. The organic coating film 2, the inorganic coating film 3, and the photocatalyst-containing inorganic coating film 4 can be formed through these steps.
Japanese Patent No. 2574061 Japanese Patent No. 2776259

  In forming the clear inorganic coating film 3 on the organic coating film 2 for makeup as described above and further forming the photocatalyst-containing inorganic coating film 4 thereon, the inorganic coating material is applied and then the inorganic coating material dryer If the baking energy for drying through the film is insufficient, the photocatalyst of the photocatalyst-containing inorganic coating 4 acts on the organic coating 2 through the inorganic coating 3, and the organic coating 2 may be deteriorated. There is a problem that the photocatalytic function of the photocatalyst-containing inorganic coating 4 formed on the inorganic coating 3 is not sufficiently exhibited.

  Further, when the photocatalyst-containing inorganic coating film 4 is further formed on the clear inorganic coating film 3, in addition to the dryer for drying the organic paint and the dryer for drying the inorganic paint, it further contains a photocatalyst. It is necessary to provide a dryer for drying the inorganic paint, and there is a problem that the space for installing the dryer and the equipment cost increase.

  The present invention has been made in view of the above points, and is capable of preventing the deterioration of an organic coating film and sufficiently exhibiting the photocatalytic function of the photocatalyst-containing inorganic coating film, and for drying the photocatalyst-containing inorganic paint. It is an object of the present invention to provide a method for painting a cement-type decorative board that makes it possible to dispense with a dryer.

  The method for applying a cement-type decorative board according to claim 1 of the present invention is a method for applying a cement-type decorative board in which an organic paint, an inorganic paint, and a photocatalyst-containing inorganic paint are applied in this order on the surface of the cement-type board. Then, after applying the inorganic paint, drying is performed under a temperature condition of 60 to 120 ° C. and a baking energy that is a product of temperature and time of 5000 ° C. · sec or more. The present invention is characterized in that a photocatalyst-containing inorganic coating is applied to a cement-based plate at 80 ° C. or higher.

  After applying the inorganic coating, drying under the above temperature conditions and time conditions can form an inorganic coating that is sufficiently dried and cured, and the photocatalyst of the photocatalyst-containing inorganic coating passes through the inorganic coating. It can prevent the organic coating film from deteriorating by acting on the film, and can fully exhibit the photocatalytic function of the photocatalyst-containing inorganic coating film formed on the inorganic coating film. Moreover, by applying the photocatalyst-containing inorganic paint to a cement-based board having a plate temperature of 80 ° C. or higher, the photocatalyst-containing inorganic paint can be dried by the amount of heat of the cement-based board, and drying for drying the photocatalyst-containing inorganic paint. It becomes possible to eliminate the machine.

  The invention of claim 2 is characterized in that, in claim 1, the content of the photocatalyst in the photocatalyst-containing inorganic paint is 0.5 to 4% by weight with respect to the dry solid content of the inorganic paint. is there.

  By setting the content of the photocatalyst within this range, the photocatalytic function can be sufficiently obtained without causing the coating film to become cloudy.

The invention of claim 3 is characterized in that, in claim 1 or 2, the coating amount of the photocatalyst-containing inorganic coating is 0.4 to 1.2 g / m ² in terms of dry weight.

  By setting the coating amount of the photocatalyst-containing inorganic coating within this range, the photocatalytic function can be sufficiently obtained without causing the coating film to become cloudy.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the inorganic paint and the photocatalyst-containing inorganic paint are each a silicone-based inorganic paint.

  According to the present invention, after applying the inorganic paint, drying / curing is performed by drying under a temperature condition of a plate temperature of 60 to 120 ° C. and a time condition in which the product of temperature and time is 5000 ° C. · sec or more. It is possible to form a sufficient inorganic coating film, prevent the photocatalyst of the inorganic film containing a photocatalyst from acting on the organic coating film through the inorganic coating film, and prevent the organic coating film from deteriorating. The photocatalyst function by the photocatalyst-containing inorganic coating film formed on the surface can be sufficiently exerted, and by applying the photocatalyst-containing inorganic paint to a cement-based board having a plate temperature of 80 ° C. or higher, The photocatalyst-containing inorganic paint can be dried by the amount of heat of the plate, and a dryer for drying the photocatalyst-containing inorganic paint can be eliminated.

  Hereinafter, the best mode for carrying out the present invention will be described.

  As the cement-based board 1, one prepared by blending an inorganic filler, a fibrous material or the like with a hydraulic glue and molding and curing it can be used. The hydraulic glue is not particularly limited, and for example, one or more kinds selected from Portland cement, blast furnace cement, blast furnace slag, calcium silicate, gypsum and the like can be used. Also, fly ash, micro silica, silica sand, etc. are used as the inorganic filler, and inorganic fibers such as pulp, synthetic fiber, asbestos, etc., and metal fibers such as steel fibers, etc., are used alone or in combination as a fibrous material. be able to. Molding can be performed by methods such as extrusion molding, cast molding, papermaking molding, press molding, etc., and after molding, autoclave curing, steam curing, and room temperature curing are performed as necessary to produce cement-based plate 1. be able to. The thickness of the cement-based plate 1 is not particularly limited, but a plate thickness of 12 to 35 mm is common.

  Then, by forming an organic coating film 2, an inorganic coating film 3, and a photocatalyst-containing inorganic coating film 4 on the surface of the cement-based board 1, a cement-based decorative board used as a building exterior material as shown in FIG. Can be obtained. The surface of the cementitious board 1 is colored with the organic coating film 2 and the inorganic coating film 3 and the photocatalyst-containing inorganic coating film 4 are formed transparently, so that makeup is performed with the organic coating film 2, and the organic coating film 2 is irradiated with ultraviolet rays. The inorganic coating film 3 prevents the deterioration, and the photocatalyst contained in the outermost photocatalyst-containing inorganic coating film 4 can impart antifouling properties.

  In the present invention, the organic coating material for forming the organic coating film 2 is not particularly limited, but it is preferable to use an organic coating mainly composed of an acrylic emulsion or an acrylic silicone emulsion. By forming the organic coating film 2 with an acrylic emulsion or an acrylic silicone emulsion in this way, high adhesion between the organic coating film 2 and the inorganic coating film 3 formed thereon can be obtained. .

  As the acrylic emulsion, for example, a core-shell type acrylic emulsion disclosed in JP-A No. 2004-195934 can be used. That is, the core-shell type acrylic emulsion is a copolymer emulsion obtained by copolymerizing a monomer component mainly composed of acrylamide in the presence of a seed emulsion as a core particle.

  Seed emulsions such as acrylic ester, styrene / acrylate ester, acrylonitrile, styrene-butadiene, acrylonitrile-butadiene, acrylate-butadiene, vinyl chloride, vinyl acetate, etc. Molecular emulsions can be used, and they can be used alone or in combination of two or more.

  Moreover, in said monomer component, the unsaturated monomer copolymerizable with acrylamide is contained as needed. As this unsaturated monomer, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-aminoethyl acrylate, acrylic acid 2- (N-methylamino) ethyl, 2- (N, N-dimethylamino) ethyl acrylate, acrylic esters such as glycidyl acrylate, vinyl esters such as vinyl acetate and vinyl propionate, and nitriles such as acrylonitrile Group-containing monomers, unsaturated carboxylic acids such as acrylic acid, maleic anhydride, fumaric acid, itaconic acid, crotonic acid, aromatic vinyl monomers such as styrene, α-methylstyrene, divinylbenzene, N- N-substituted unsaturated carboxylic acid amides such as methylolacrylamide can be selected. That. Among these, it is preferable to use an unsaturated monomer having a functional group such as a carboxyl group, a hydroxyl group, an amino group, a methylol group, or a glycidyl group.

  This core-shell structure acrylic emulsion is produced by a known polymerization technique using a polymerization initiator and a chain transfer agent together with the above-mentioned materials. Such core-shell type acrylic emulsions have various types known so far (see, for example, JP-A-2000-204285), and commercially available products can also be used.

  Among such core-shell type acrylic emulsions, it is preferable to use those having an acid amount in the range of 5 to 15% by weight in the shell portion. By setting the acid amount of the shell portion within this range, the interlayer adhesion strength between the organic coating film and the coating film can be increased. When the acid amount of the shell portion is less than 5% by weight, An improvement in interlayer adhesion strength with the coating film cannot be expected. The same applies when the acid amount of the shell part exceeds 15% by weight.

  Moreover, as an acrylic silicone emulsion, what mix | blended the silicone component with the acrylic emulsion currently disclosed by patent 3347097 can be used, for example.

The acrylic emulsion preferably contains methyl methacrylate and butyl acrylate as resin main components. The organic coating film must satisfy one of the following requirements.
(1) The gel fraction of the organic coating film with respect to the organic solvent is 30% or less.
(2) The Tg (glass transition temperature) of the organic coating film is 50 ° C. or lower.
(3) The contact angle of the top-coated inorganic coating film with the inorganic coating is 40 degrees or less.

  In the case of a decorative board in which the organic coating film as described above is formed and the surface thereof is coated with an inorganic coating, the coating film adhesion due to the inorganic coating is extremely excellent as well as the weather resistance. Making the gel fraction of the organic coating film low with respect to the organic solvent as in (1) means that the organic coating film is easily exposed to the organic solvent. Here, the gel fraction is an index of solvent resistance. Specifically, for example, the gel fraction of the organic coating film is obtained by immersing the organic coating film dried (120 ° C., 4 minutes) after application in acetone for 5 hours. It is shown as a weight ratio remaining after the treatment.

  The organic coating and inorganic coating have a low gel fraction, that is, low solvent resistance. The organic solvent in the top coating of the inorganic coating swells and dissolves the organic coating at the interface with the organic coating. This means that the organic coating film and the inorganic coating film are welded to obtain a strong physical adhesion, and the situation is strong against changes over time. The gel fraction of the organic coating is preferably 30% or less, more preferably 0%, or an approximation thereof, so that the inorganic coating with the inorganic coating is strongly adhered. Sex can be obtained.

  It is possible to lower the gel fraction with respect to the organic solvent by selecting the resin component in the organic paint and adjusting the composition and the ratio thereof. For example, in an acrylic emulsion prepared with molecular weights of approximately the same level, methyl methacrylate (MMA) and butyl acrylate (BA) are included in the resin main component, that is, 50% by weight or more of the resin component. The ratio of the components and the mutual ratio of methyl methacrylate (MMA) and butyl acrylate (BA) are adjusted. In order to lower the gel fraction, it is generally appropriate that the ratio of methyl methacrylate (MMA) and butyl acrylate (BA) as main components is MMA / BA = 1 to 2 as a weight ratio. More preferably, MMA / BA = 1.1 to 1.6. When the ratio of methyl methacrylate (MMA) exceeds 2, the gel fraction cannot be expected to be reduced to 30% or less, and a substantial improvement in adhesion cannot be obtained. On the other hand, when the weight ratio is less than 1, the strength, durability, etc. of the coating film as a coated body tend not to be sufficient. Further, in the range of the weight ratio MMA / BA = 1.1 to 1.6, the gel fraction is substantially 0, and excellent adhesion can be obtained. It should be noted that the proportion of methyl methacrylate (MMA) and butyl acrylate (BA) as the main component of the resin is preferably 60% by weight or more, and blending of acrylate or methacrylate as the other component is appropriate. Is possible.

  Further, as shown in (2), when the Tg is set to a low level of 50 ° C. or lower, the organic coating film is softened and the interface with the inorganic coating film tends to be in a fused state, resulting in a physically strong result. A decorative board having adhesion can be obtained.

  Further, as in (3), the adhesiveness between the organic coating film and the inorganic coating film can be improved also by reducing the contact angle of the top coating inorganic coating to the organic coating film to 40 degrees or less. The small contact angle with respect to the inorganic coating film means that the wettability is good, that is, the inorganic coating can be uniformly applied to the organic coating film, and the pores generated by drainage of the organic coating film, etc. It means that the inorganic paint penetrates into (pores) and the like, an anchoring effect is obtained and stabilized, and the adhesion is improved.

  Thus, in order to make a contact angle small, a silicone component is mix | blended with an acrylic emulsion, and it uses as an acrylic silicone emulsion. When blending the silicone component into the acrylic emulsion, the proportion of the total resin component is suitably in the range of 5 wt% to 20 wt%. If the amount is less than 5% by weight, no substantial effect is obtained. On the other hand, if the amount exceeds 20% by weight, the performance deteriorates in terms of water resistance.

  An organic paint can be obtained by blending various components as needed into the acrylic emulsion or acrylic silicone emulsion obtained as described above.

  For example, an emulsifier and a dispersant can be appropriately blended in the emulsion. Low molecular emulsifiers and reactive emulsifiers can be preferably used. However, from the viewpoint of coating film adhesion, it is desirable to suppress the use of low molecular emulsifiers that cause poor adhesion as a free soap, so the proportion of low molecular emulsifier is less than 50% and reactive emulsifier is 50% or more. Is desirable. In addition, pigments, fillers, mineral oil-based antifoaming agents, thickeners, paraffin-based water repellents, and the like can be appropriately blended in the emulsion. Examples of pigments include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyaning ray, and hansa yellow, and inorganic pigments such as titanium oxide, barium sulfate, bengara, calcium carbonate, alumina, iron oxide, and composite metal oxides. Examples of fillers include general silica powder, barium sulfate, sand, and resin beads. The particle size of the pigment or filler is not particularly limited. The blending of components other than the resin component is preferably 5% by weight or less with respect to the entire emulsion.

  Next, in the present invention, as the inorganic paint for forming the inorganic coating film 3, a silicone-based inorganic paint can be used. As this silicone type inorganic coating material, what is disclosed by patent 3243442, patent 3193432, and Unexamined-Japanese-Patent No. 9-249822 can be used, for example.

The silicone-based inorganic paint disclosed in Japanese Patent No. 3243442 is
(A): General formula R ¹ _n SiX _4-n (1)
(In the formula (1), R ¹ is the same or different alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4- A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of an epoxycyclohexylethyl group and a γ-mercaptopropyl group, n is an integer of 0 to 3, X is an alkoxy group, an acetoxy group, an oxime group, A hydrolyzable group selected from the group consisting of an enoxy group, an amino group, an aminoxy group and an amide group.
An organosilane obtained by partially hydrolyzing a hydrolyzable organosilane represented by the formula (I) in colloidal silica dispersed in an organic solvent or water under the condition that 0.001 to 0.5 mol of water is used per 1 mol of X. Silica dispersion oligomer solution of
(B): Average composition formula R ² _a Si (OH) _b O _{(4-ab) / 2} (2)
(In the formula (2), R ² is the same or different alkyl group, cycloalkyl group, alkenyl group, halogen-substituted hydrocarbon group, γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4- A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of an epoxycyclohexylethyl group and a γ-mercaptopropyl group, wherein a and b are 0.2 ≦ a ≦ 2, 0.0001 ≦ b ≦, respectively. 3 and a number satisfying the relationship of a + b <4.)
And a polyorganosiloxane containing 1 to 30 mol% of phenyl groups based on the total R ² groups in R ² of the component, and
(C): A catalyst that accelerates the condensation reaction between the component (A) and the component (B) is an essential component, and the component (A) contains 5 to 95% by weight of silica as a solid content. At least 50 mol% is an organosilane having n = 1, and 99 to 1 part by weight of component (B) is blended with 1 to 99 parts by weight of component (A).

  The silica-dispersed oligomer as the component (A) is a main component of a base polymer having a hydrolyzable group as a functional group to be subjected to a curing reaction during film formation. This was done by adding one or more hydrolyzable group-containing organosilanes represented by the general formula (1) to colloidal silica dispersed in an organic solvent or water, and adding water in colloidal silica or separately. It is obtained by partially hydrolyzing the hydrolyzable organosilane with water.

The group R ¹ in the hydrolyzable organosilane represented by the general formula (1) is an alkyl group, a cycloalkyl group, an alkenyl group, a halogen-substituted hydrocarbon group, a γ-methacryloxypropyl group, or a γ-glycidoxypropyl. A monovalent hydrocarbon group having 1 to 8 carbon atoms selected from the group consisting of a group, 3,4-epoxycyclohexylethyl group and γ-mercaptopropyl group, for example, methyl group, ethyl group, propyl group, butyl group Alkyl groups such as pentyl group, hexyl group, heptyl group and octyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as 2-phenylethyl group and 3-phenylpropyl group; phenyl group and tolyl group Aryl groups such as vinyl groups, alkenyl groups such as allyl groups, chloromethyl groups, γ-chloropropyl groups, , 3,3-trifluoropropyl groups such as halogen-substituted hydrocarbon groups and γ-methacryloxypropyl groups, γ-glycidoxypropyl groups, 3,4-epoxycyclohexylethyl groups, γ-mercaptopropyl groups, etc. A hydrocarbon group etc. can be illustrated. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  X of the hydrolyzable group is a hydrolyzable group selected from the group consisting of an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. Alkoxy groups are preferred because of their availability and ease of preparing silica-dispersed oligomer solutions.

  Particularly, tetramethoxysilane, tetraethoxysilane and the like can be exemplified as tetraalkoxysilane of n = 0, and methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, n = 1 as organotrialkoxysilane, Examples thereof include phenyltrimethoxysilane, phenyltriethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane, and n = 3 triorganoalkoxysilane. Examples thereof include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. Furthermore, organosilane compounds generally called silane coupling agents are also included in the alkoxysilanes.

  Of these hydrolyzable organosilanes represented by the general formula (1), 50 mol% or more is required to be a trifunctional one represented by n = 1. They are more preferably 60 mol% or more, most preferably 70 mol% or more. If this is less than 50 mol%, sufficient coating film hardness cannot be obtained, and the dry curability tends to be poor.

  The colloidal silica in the component (A) is essential for increasing the hardness of the cured coating of the silicone-based inorganic paint. As such colloidal silica, water-dispersible or non-aqueous organic solvent-dispersible colloidal silica such as alcohol can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value. Moreover, when using water dispersible colloidal silica, the water which exists as components other than solid content can be used for a hydrolysis of the organosilicon compound of (A) component. These are usually made from water glass, but such colloidal silica is readily available commercially. The organic solvent-dispersed colloidal silica can be easily prepared by replacing the water of the water-dispersible colloidal silica with an organic solvent. Such an organic solvent-dispersed colloidal silica can also be easily obtained as a commercial product, like the water-dispersed colloidal silica. Examples of the organic solvent in which colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, and the like. And ethylene glycol derivatives; derivatives of diethylene glycol such as diethylene glycol and diethylene glycol monobutyl ether, diacetone alcohol, and the like, and one or more selected from the group consisting of these can be used. In combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, and the like can also be used.

  In the component (A), colloidal silica is contained in the range of 5 to 95% by weight as the silica content. More preferably, it is 10 to 90 weight%, Most preferably, it is the range of 20 to 85 weight%. If the content is less than 5% by weight, the desired film hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse silica, and component (A) may cause problems such as gelation. .

  The silica-dispersed oligomer of component (A) can be usually obtained by partially hydrolyzing a hydrolyzable group-containing organosilane in water-dispersed colloidal silica or organic solvent-dispersed colloidal silica. The amount of water used relative to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group (X). When the ratio is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and when it exceeds 0.5 mol, the stability of the partial hydrolyzate is deteriorated. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organoalkoxysilane and colloidal silica may be mixed and added with a necessary amount of water, and at this time, the partial hydrolysis reaction proceeds at room temperature. You may heat to 60-100 degreeC in order to accelerate a partial hydrolysis reaction. Furthermore, 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, toluene for the purpose of promoting partial hydrolysis reaction Organic acids such as sulfonic acid and oxalic acid and inorganic acids may be used as the catalyst.

  In order to obtain the component (A) stably in the long term, the pH of the liquid is 2.0 to 7.0, preferably 2.5 to 6.5, more preferably 3.0 to 6.0. It is good to. If the pH is outside this range, the amount of water used is 0.3 mol or more per 1 mol of the group (X), and the long-term performance deterioration of the component (A) is remarkable. When the pH of the component (A) is outside this range, it may be adjusted by adding a basic reagent such as ammonia or ethylenediamine if it is more acidic than this range. Adjustment may be performed using an acidic reagent such as acetic acid. However, the adjustment method is not particularly limited.

The silanol group-containing polyorganosiloxane (B) represented by the average composition formula (2) is an important component that characterizes the present invention. (2) In the formula, as R ² , the same as R ¹ in the formula (1) is exemplified, but preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group, a γ-glycidoxypropyl group, Substituted hydrocarbon groups such as γ-methacryloxypropyl group and 3,3,3-trifluoropropyl group, more preferably methyl group. Further, in the formula, a and b are numbers satisfying the above relationship, respectively, and if a is less than 0.2 or b exceeds 3, there is a problem such as a crack in the cured film, and a exceeds 2 When it is 4 or less or when b is less than 0.0001, curing does not proceed well.

Further, ^{R 2} is 1 to 30 mol% of the total ^{R 2} groups phenyl group, preferably it to contain 5 to 20 mol%, the resulting coating film having excellent gloss, leveling. If the number of phenyl groups is less than 1 mol% based on the total R ² groups, the desired gloss cannot be obtained, and if it exceeds 30 mol%, the gloss decreases and the coating film becomes soft.

  Such a silanol group-containing polyorganosiloxane can be prepared by a known method using a large amount of methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or a mixture of one or more of the corresponding alkoxysilanes. It can be obtained by hydrolysis with water. When a silanol group-containing polyorganosiloxane is obtained by hydrolysis with a known method using alkoxysilane, a trace amount of alkoxy groups that are not hydrolyzed may remain. That is, 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 curing catalyst which is the component (C) accelerates the condensation reaction between the component (A) and the component (B) and cures the coating. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, 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-aminopropylmethyl Amine-based silane coupling agents such as dimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl titane , Tetrabutyl titanate, titanium tetraacetylacetonate and other titanium compounds, methyltrichlorosilane, dimethyldichlorosilane, trimethylmonochlorosilane, and other halogenated silanes. In addition to these, component (A) and component (B) There is no particular limitation as long as it is effective for the condensation reaction with.

  The blending ratio of the component (A) and the component (B) is 99 to 1 part by weight of the component (B) with respect to 1 to 99 parts by weight of the component (A), more preferably 5 to 95 parts by weight of the component (A). The component (B) is 95 to 5 parts by weight, and most preferably the component (B) is 90 to 10 parts by weight with respect to the component (A) 10 to 90 parts by weight (provided that the component (A) and the component (B) The total of the components is 100 parts by weight). When the component (A) is less than 1 part by weight, the room temperature curability is inferior and sufficient film hardness cannot be obtained. On the other hand, when it exceeds 99 parts by weight, the curability is unstable and a good coating film is obtained. There may not be.

  Moreover, it is preferable that the addition amount of (C) component is 0.0001-10 weight part with respect to 100 weight part in total of (A) component and (B) component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If it is less than 0.0001 part by weight, it will not be cured at room temperature. Moreover, when it exceeds 10 weight part, heat resistance and a weather resistance will worsen.

  This silicone-based inorganic coating can be diluted with various organic solvents for ease of handling. The type of the organic solvent can be selected according to the type of the monovalent hydrocarbon group or the molecular weight of the component (A) or the component (B). Examples of such organic solvents include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol shown as dispersion solvents for colloidal silica; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples include ethylene glycol derivatives such as ether; derivatives of diethylene glycol such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or two or more selected from the group consisting of these can be used. . Examples of solvents that can be used in combination with these hydrophilic organic solvents include toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and methyl ethyl ketoxime.

  As a method for preserving this silicone-based inorganic paint, it is common to take a three-packaging form for preserving the components (A), (B) and (C), but the components (A) and (C) It is also possible to separate the mixed component and the component (B) into two package types and mix them at the time of use, or mix all the components and store them in one container. However, when mixing and storing (A) component and (C) component, it is preferable to add (C) component after adjusting the pH of (A) component to 2-7, and also (A) component The amount of water used per 1 mol of the hydrolyzable group (X) of the organoalkoxysilane is preferably 0.3 mol or less.

  In addition, leveling agents, thickeners, pigments, dyes, aluminum pastes, glass frits, metal powders, antioxidants, matting agents, UV absorbers, etc., can be added to this silicone-based inorganic paint as necessary. It can be added within a range that does not affect.

Next, the silicone-based inorganic paint disclosed in Japanese Patent No. 3193932 is
General formula R ¹ _n SiX _4-n (3)
(In formula (3), R ¹ 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)
In a state where 0.001 to 0.5 mol of water is used per 1 mol of X1 in a state where fine particle oxide is dispersed in a particle size of 0.2 to 3 μm, the hydrolyzable organosilane represented by To what was obtained by hydrolysis,
General formula OH (R ² ₂ SiO) _m H (4)
(In formula (4), R ² represents the same or different substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and m represents 1 or more.)
A silicone diol-containing fine particle oxide-dispersed oligomer (component D) containing 5 to 30% by weight of a silicone diol component having a weight average molecular weight of 10,000 or less represented by:
Average composition formula R ³ _a Si (OH) _b O _{(4-ab) / 2} (5)
(In the formula (5), R ³ 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 <2.0, 0,. (A number satisfying the relationship of 0001 ≦ b ≦ 3 and a + b <4)
A polyorganosiloxane (E component) containing a silanol group in the molecule represented by:
Each component of the catalyst (F component) is contained.

  The silicone diol-containing fine particle oxide-dispersed oligomer of component D is the main component of a base polymer having a hydrolyzable group X as a functional group that is subjected to a curing reaction during film formation. This is obtained by adding a silicone diol represented by the above general formula (4) to one or more hydrolyzable organosilanes represented by the above general formula (3). It can be obtained by partially hydrolyzing the hydrolyzable organosiloxane by adding a necessary amount of water while dispersing the fine particle oxide or after completing the fine particle oxide dispersion. The silicone diol may be added before hydrolyzing the hydrolyzable organosilane, at the time of hydrolysis, or after hydrolysis.

Here, the group R ¹ in the hydrolyzable organosilane represented by the general formula (3) represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group or an ethyl group. Group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and other alkyl groups; cyclopentyl group, cyclohexyl group and other cycloalkyl groups; 2-phenylethyl group, 2-phenylpropyl group, 3-phenylpropylene Aralkyl groups such as ruthel groups; aryl groups such as phenyl groups and tolyl groups; alkenyl groups such as vinyl groups and allyl groups; halogen substitutions such as chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl Hydrocarbon group; and γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-medium It may be exemplified substituted hydrocarbon group such as mercaptopropyl group. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  Examples of the hydrolyzable group X in the hydrolyzable organosilane represented by the general formula (3) include an alkoxy group, an acetoxy group, an oxime group, an enoxy group, an amino group, an aminoxy group, and an amide group. . Alkoxy groups are preferred because of their availability and ease of preparing fine particle oxide-dispersed oligomer solutions.

  Such hydrolyzable organosilanes include mono-, di-, tri-, and tetra-functional alkoxysilanes in which n in the general formula (3) is an integer of 0 to 3, Examples include acetoxysilanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, and amidosilanes. Alkoxysilanes are preferred because they are readily available and easy to prepare a fine particle oxide-dispersed oligomer solution.

  In particular, tetramethoxysilane, tetraethoxysilane, and the like can be exemplified as the n = 0 tetraalkoxysilane, and the methyltrialkoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and the like can be exemplified as the n = 1 organotrialkoxysilane. Examples thereof include isopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane, and n = 3 triorganoalkoxysilane. Examples of silane include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. An organosilane compound generally called a silane coupling agent can also be used as alkoxysilanes.

  Of the hydrolyzable organosilanes represented by the general formula (3) as described above, 50 mol% or more is preferably trifunctional with n = 1. More preferably, it is 60 mol% or more, and most preferably 70 mol% or more. When the trifunctional compound of n = 1 is less than 50 mol%, it is difficult to obtain a sufficient film hardness and the dry curability may be easily deteriorated.

  The powdery fine particle oxide in the component D is essential for controlling the gloss of the silicone-based inorganic paint and acts as a matting agent. Examples of the fine particle oxide include silicon oxide, aluminum oxide, titanium oxide, etc., and those whose surfaces are subjected to silica treatment, alumina treatment, coupling treatment, etc. for the purpose of enhancing dispersibility. Can be used.

  Then, the particulate oxide is directly dispersed in the hydrolyzable organosilane represented by the general formula (3), and the hydrolyzable organosilane is partially hydrolyzed with a necessary amount of water to prepare the component D. However, for the purpose of increasing the degree of dispersion of the powdered fine particle oxide, it is dispersed with an organic solvent such as alcohol, and the hydrolyzable organosilane is partially hydrolyzed with a necessary amount of water to prepare the component D. Also good. Examples of the organic solvent include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol and isobutanol; ethylene glycol derivatives such as ethylene glycol, ethylene glycol monobutyl ether and ethylene glycol monoethyl ether; diethylene glycol, And diethylene glycol derivatives such as diethylene glycol monobutyl ether; and diacetone alcohol. One or two or more selected from the group consisting of these can be used, but in combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, Methyl ethyl ketoxime can also be used.

  The particle diameter of the fine particle oxide dispersed in the hydrolyzable organosilane oligomer of component D is in the range of 0.2 to 3 μm. When the particle diameter is less than 0.2 μm, it is difficult to control the gloss, and when the particle diameter exceeds 3 μm, the film formability may be impaired. In the component D, the fine particle oxide is contained in the range of preferably 5 to 30% by weight, more preferably 8 to 25% by weight as the solid content. When the content is less than 5% by weight, it is difficult to control the gloss, and when it exceeds 30% by weight, there is a possibility that inconveniences such as impaired film formability may be caused.

The silicone diol in component D is essential for obtaining a stable gloss of the silicone-based inorganic paint. The compounding ratio in the D component of the silicone diol represented by the general formula (4) is 5 to 30% by weight. If it is less than 5% by weight, it is difficult to obtain long-term gloss stability, and if it exceeds 30% by weight, curing of the coating film may be delayed. The weight average molecular weight of the silicone diol component is 10,000 or less, preferably 5000 or less, more preferably 1000 or less. A silicone diol component having a weight average molecular weight exceeding 10,000 has poor compatibility with the resin and is difficult to use. Here, R ^{2 in} the general formula (4) of the silicone diol can be used without particular limitation as long as it is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms. The hydrocarbon group similar to R < ¹ > in the said Formula (3) can be mentioned.

  The organosilane oligomer of component D can be obtained by partially hydrolyzing the hydrolyzable organosilane of the general formula (1). The amount of water used relative to the hydrolyzable organosilane is 0.001 to 0.5 mol of water relative to 1 mol of the hydrolyzable group X. When the amount of water used is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and when the amount of water used exceeds 0.5 mol, the stability of the partial hydrolyzate becomes poor. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organosilane and a necessary amount of water may be added and blended. At this time, the partial hydrolysis reaction proceeds at room temperature, but the partial hydrolysis reaction is promoted. Therefore, heating may be performed at a temperature of 60 to 100 ° C. Furthermore, 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, toluene for the purpose of promoting partial hydrolysis reaction An inorganic acid such as sulfonic acid or oxalic acid or an organic acid may be used as a catalyst.

  In order to obtain long-term stable performance, the silicone diol-containing fine particle oxide-dispersed oligomer of component D has a pH of the liquid in the range of 2.0 to 7.0, more preferably pH 2.5 to 6.5. It is better to adjust to the range, even more preferably to the range of pH 3.0 to 6.0. When the pH is out of this range, the long-term performance deterioration of the D component may be remarkable particularly when the amount of water used is 0.3 mol or more with respect to X1 mol. If the pH of component D is outside this range, a basic reagent such as ammonia or ethylenediamine may be added to adjust the pH when it is acidic from this range, and hydrochloric acid, nitric acid, What is necessary is just to adjust pH using acidic reagents, such as an acetic acid. The adjustment method is not particularly limited.

The E component silanol group-containing polyorganosiloxane having an average composition formula represented by the above formula (5) is an important component constituting one of the characteristics of the silicone-based inorganic paint. In formula (5), R ³ may be the same as R ¹ in formula (3), preferably an alkyl group having 1 to 4 carbon atoms, a phenyl group, a vinyl group, γ- Substituted hydrocarbon groups such as a glycidoxypropyl group, γ-methacryloxypropyl group, and 3,3,3-trifluoropropyl group, more preferably a methyl group and a phenyl group. In the formula (5), a and b are numbers satisfying the relations 0.2 ≦ a <2.0, 0.0001 ≦ b ≦ 3, and a + b <4, respectively, and a is less than 0.2 or b is If it exceeds 3, there are disadvantages such as causing cracks in the cured film, and if a is more than 2.0 and 4 or less, or if b is less than 0.0001, there is an inconvenience that curing does not proceed well.

  Examples of such a silanol group-containing polyorganosiloxane of formula (5) include, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or a mixture of two or more alkoxysilanes corresponding thereto. Can be obtained by hydrolysis with a large amount of water by a known method. When a silanol group-containing polyorganosiloxane is obtained by hydrolysis using a known method using alkoxysilane, a trace amount of alkoxy groups that are not hydrolyzed may remain. That is, 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 F component catalyst serves as a curing catalyst for accelerating the condensation reaction between the D component and the E component and curing the coating. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Quaternary ammonium salts such as tetramethylammonium acetate, amines such as tetraethylpentamine; N (-β-aminoethyl) -γ-aminopropyltrimethoxysilane, N (-β-aminoethyl) -γ -Amine-based silane coupling agents such as aminopropylmethyldimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl tita And titanium compounds such as tetrabutyltitanate and titanium tetraacetylacetonate, and halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylmonochlorosilane. There is no particular limitation as long as it is effective for the condensation reaction.

  The mixing ratio of the D component and the E component is preferably 70 to 30 parts by weight of the E component with respect to 30 to 70 parts by weight of the D component, more preferably 60 to 40 parts by weight of the E component with respect to 40 to 60 parts by weight of the D component. (However, the total amount of D component and E component is 100 parts by weight). When the D component is less than 30 parts by weight, it is difficult to control the gloss of the resulting inorganic coating film, and when the E component exceeds 70 parts by weight, the film formability of the inorganic coating film may be impaired. By changing the blending ratio of the D component and the E component in the above range, the gloss of the inorganic coating film can be easily adjusted. When the blending ratio is adjusted so as to increase the D component, the inorganic coating film The glossiness of the inorganic coating film can be increased by adjusting the blending ratio so as to reduce the D component.

  Moreover, it is preferable that the addition amount of the catalyst of F component is 0.0001-10 weight part with respect to a total of 100 weight part of D component and E component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If the addition amount of the F component catalyst is less than 0.0001 parts by weight, it may not be cured at room temperature, and if the addition amount of the F component catalyst exceeds 10 parts by weight, the heat resistance and weather resistance of the resulting inorganic coating film May be worse.

  The silicone-based inorganic paint prepared as described above can be used after being diluted with various organic solvents for ease of handling. The type of the organic solvent is selected according to the type or molecular weight of the D component or E component monovalent hydrocarbon group. Examples of such an organic solvent include those shown as dispersion solvents for fine particle oxides, etc. 1 type or 2 types or more selected from the group consisting of these can be used.

  In general, the silicone-based inorganic paint is stored in a three-packed form in which the D component, the E component, and the F component are stored separately. The mixed component of the D component and the F component, the E component, The two may be divided into two package types, and the two may be mixed at the time of use. Alternatively, all the components may be mixed and stored in one container. However, when the D component and the F component are mixed and stored, it is preferable to adjust the pH of the D component to 2 to 7 and then add and mix the F component. It is preferable to use a solution in which the amount of water used is 0.3 mol or less with respect to 1 mol of the hydrolyzable group.

  In addition, leveling agents, thickeners, pigments, dyes, aluminum pastes, glass frit, metal powders, antioxidants, UV absorbers, etc. will not affect the properties of this silicone-based inorganic paint as necessary. It can be added within the range.

Next, JP-A-9-249822 discloses two types of silicone-based inorganic paints. One of the two types of silicone-based inorganic paint (hereinafter referred to as silicone-based inorganic paint (1))
General formula (R ¹ ) _m Si (OR ² ) _4-m (6)
(In the formula (6), ^{R 1} each represent a methyl group, an ethyl group or a phenyl group, ^{R 2} is .m each represents an alkyl group having 1 to 8 carbon atoms is 0, 1 or 2.)
An ultraviolet absorber is blended in a silicon alkoxide-based paint mainly composed of a silicon compound represented by formula (1) and / or a partial hydrolyzate thereof.

The silicon alkoxide mainly composed of the silicon compound represented by the general formula (6) and / or a partial hydrolyzate thereof is a mixture mainly composed of the following compounds (i), (ii) and (iii): Can be obtained by diluting with an appropriate solvent, adding a necessary amount of a curing agent and a catalyst, followed by hydrolysis and condensation polymerization, having a weight average molecular weight Mw of 500 to 3000 in terms of polystyrene, and a molecular weight distribution Mw / Mn ( Mn preferably has a number average molecular weight) of 1.1 to 3.0. More preferably, Mw = 600 to 3000 and Mw / Mn = 1.2 to 1.8. When the weight average molecular weight and the molecular weight distribution are smaller than these ranges, the curing shrinkage during the condensation polymerization becomes large, and cracks tend to occur in the coating film after baking. Also, when the weight average molecular weight and molecular weight distribution are larger than this range, the reaction is too slow and hard to cure, or even when cured, the coating tends to be soft, or the leveling properties of the coating tend to be very poor. There is.
(I): 20 to 200 parts by weight of the silicon compound and colloidal silica represented by m = 0 in the general formula (6) (ii): 100 parts by weight of the silicon compound represented by m = 1 in the general formula (6) (iii) ): 0 to 80 parts by weight of a silicon compound represented by m = 2 in the general formula (6) As these silicon compounds, alkoxysilanes in the later-described formula (7) can be used. Further, the component (i) colloidal silica (colloidal silica) is used by dispersing the fine particle silica component in water, an organic solvent such as methanol, or a mixed solvent thereof, as long as they are colloidal. There are no particular restrictions on the solvent type. In addition, the compounding quantity of the colloidal silica of a component (i) is a weight part also including a dispersion medium.

  Although it does not specifically limit as said hardening | curing agent used as needed in a silicone type inorganic coating material (1), For example, inorganic acids, such as hydrochloric acid, phosphoric acid, a sulfuric acid, formic acid, an acetic acid, chloroacetic acid An acidic catalyst such as a dilute solution of an organic acid such as a basic catalyst described later can be used alone or in combination of two or more. Further, when colloidal silica is used as the component (i), the colloidal silica exhibits acidity, so that it becomes a catalyst, and nothing is required as an acidic catalyst.

  As the catalyst used as necessary in the silicone-based inorganic paint (1), a basic catalyst is used. The basic catalyst is not particularly limited. For example, amines such as triethanolamine; γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, etc. Aminosilanes; salts of inorganic acids (eg, hydrochloric acid, nitric acid, phosphoric acid, etc.) or organic acids (eg, formic acid, acetic acid, propionic acid, etc.), such as ammonia, trimethylamine, triethylamine, n-butylamine, or inorganic or organic acids Examples thereof include metathesis salts of salts and quaternary ammonium salts. These types and addition amounts are not limited at all.

  In addition to the above-mentioned components, the silicone-based inorganic paint (1) may contain a filler other than colloidal silica (for example, an inorganic filler such as alumina sol or fumed silica), a colorant, a diluting solvent, and a thickener as necessary. One or more kinds of various additives such as an agent and a surfactant can be blended. Although it does not specifically limit as this dilution solvent, For example, alcohols, such as methanol, ethanol, isopropanol (IPA); Cellosolves, such as ethylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc. can be mentioned, These are 1 type or Two or more kinds can be used in combination.

  The silicone-based inorganic paint (1) can be stably used within the aforementioned molecular weight range by adjusting its pH value to 3.8 to 6.0. If the pH value is outside this range, the silicone-based inorganic paint (1) becomes unstable, and the usable period after the preparation of the silicone-based inorganic paint (1) may be limited. Here, the pH value adjusting method is not particularly limited. For example, when the pH value becomes less than 3.8 when the raw material of the silicone-based inorganic paint (1) is mixed, the predetermined range is set using a basic reagent such as ammonia. What is necessary is just to adjust to the inside pH value, and what is necessary is just to adjust to the said predetermined range using acidic reagents, such as hydrochloric acid, when pH value exceeds 6.0. Depending on the pH value, the reaction does not proceed conversely with a small molecular weight, and if it takes time to reach the molecular weight range, the silicone-based inorganic paint (1) is heated to promote the reaction. Alternatively, the pH value may be lowered with an acidic reagent and the reaction may be advanced, and then returned to a predetermined pH value with a basic reagent.

  Even when the pH value is adjusted as described above, or even when the pH value is not adjusted, the condensation reaction is promoted by adding a basic catalyst to the silicone-based inorganic paint (1) during use or at least during use, Since the number of crosslinking points in the coating film can be increased, it is possible to stably obtain a coating film having good crack resistance. Further, by promoting the crosslinking reaction, the curing time can be shortened or the curing temperature can be lowered, which is economical.

Of the two types of silicone-based inorganic paints disclosed in JP-A-9-249822, the other silicone-based inorganic paint (hereinafter referred to as silicone-based inorganic paint (2)) is:
Formula (R ³ ) _n SiX _4-n (7)
(In Formula (7), R ³ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, X represents a hydrolyzable group, and n is an integer of 0 to 3. )
A silica-dispersed oligomer solution of organosilane (G) obtained by partially hydrolyzing the hydrolyzable organosilane represented by the formula (I) with colloidal silica dispersed in an organic solvent and / or water;
Average composition formula (R ⁴ ) _d Si (OH) _e O _{(4-de) / 2} (8)
(In Formula (8), R ⁴ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and d and e are 0.2 ≦ d ≦ 2.0 and 0.0001 ≦, respectively. (It is a number that satisfies the relationship of e ≦ 3 and d + e <4.)
A polyorganosiloxane (H) containing a silanol group in the molecule represented by:
Of the curing catalyst (I),
A silicon alkoxide paint containing the three components (G), (H), and (I) as essential components is blended with an ultraviolet absorber.

  The silica-dispersed oligomer of component (G) used in the silicone-based inorganic paint (2) is a main component of a base polymer having a hydrolyzable group X as a functional group that is subjected to a curing reaction during film formation. This is achieved by adding one or more hydrolyzable organosilanes represented by the above general formula (7) to colloidal silica dispersed in an organic solvent, water, or a mixed solvent thereof, to form colloidal silica. It can be obtained by partially hydrolyzing the hydrolyzable organosilane with water therein or water added separately.

R ³ in the hydrolyzable organosilane represented by the general formula (7) is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, Alkyl groups such as butyl group, pentyl group, hexyl group, heptyl group and octyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aralkyl groups such as 2-phenylethyl group and 3-phenylpropyl group; phenyl group and tolyl Aryl groups such as vinyl groups; alkenyl groups such as vinyl groups and allyl groups; halogen-substituted hydrocarbon groups such as chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups; γ-methacryloxypropyl groups Substituted hydrocarbon such as γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, γ-mercaptopropyl group, etc. It can be exemplified, and the like. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of easy synthesis or availability.

  Examples of the hydrolyzable group X in the general formula (7) 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 preferable because it is easily available and a silica-dispersed oligomer solution (G) can be easily prepared. Examples of the hydrolyzable organosilane include mono-, di-, tri-, and tetra-functional alkoxysilanes in which the n in the general formula (7) is an integer of 0 to 3, acetoxy Examples thereof include silanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, and amidosilanes. Among these, alkoxysilanes are preferable because they are easily available and the silica-dispersed oligomer solution (G) is easy to prepare.

  In particular, tetramethoxysilane, tetraethoxysilane, and the like can be exemplified as the n = 0 tetraalkoxysilane, and the methyltrialkoxysilane, methyltriethoxysilane, methyltrimethoxysilane, and the like can be exemplified as the n = 1 organotrialkoxysilane. Examples thereof include isopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Examples of n = 2 diorganodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane. Further, examples of the triorganoalkoxysilane with n = 3 include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, and dimethylisobutylmethoxysilane. Organosilane compounds generally called silane coupling agents can also be used as alkoxysilanes.

  Of these hydrolyzable organosilanes of the general formula (7), 50 mol% or more is preferably a trifunctional compound represented by n = 1. More preferably, it is 60 mol% or more, and most preferably 70 mol% or more. When the trifunctional compound with n = 1 is less than 50 mol%, it is difficult to obtain a sufficient coating film hardness, and the dry curability tends to be inferior.

  As the colloidal silica used in the component (G), water-dispersible or non-aqueous organic solvent-dispersible colloidal silica such as alcohol can be used, and the colloid used in the silicone-based inorganic paint (1) described above. The same silica gel can be used. Generally, such colloidal silica contains 20 to 50% by weight of silica as a solid content, and the amount of silica can be determined from this value.

  When water-dispersible colloidal silica is used, water present as a component other than the solid content can be used for hydrolysis of the component (G). Water-dispersible colloidal silica is usually made from water glass, but such colloidal silica is readily available commercially. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the water of the water-dispersible colloidal silica with an organic solvent. Such an organic solvent-dispersible colloidal silica can be easily obtained as a commercial product in the same manner as the water-dispersible colloidal silica. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl ether acetate. Examples include ethylene glycol derivatives; diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or two or more selected from the group consisting of these can be used, but in combination with these hydrophilic organic solvents, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, Methyl ethyl ketoxime can also be used.

  The colloidal silica in the component (G) is essential for increasing the hardness of the cured coating of the silicone-based inorganic paint (2). In the component (G), the colloidal silica is preferably contained in the range of 5 to 95% by weight as the silica solid content. More preferably, it is 10 to 90 weight%, Most preferably, it is the range of 20 to 85 weight%. If the content is less than 5% by weight, the desired film hardness cannot be obtained, and if it exceeds 95% by weight, it is difficult to uniformly disperse the silica, which may cause inconveniences such as gelation in the component (G). .

  The silica-dispersed oligomer of organosilane as component (G) is usually a partial hydrolysis of hydrolyzable organosilane of general formula (7) in at least one of water-dispersible colloidal silica and organic solvent-dispersible colloidal silica. Can be obtained. The amount of water used relative to the hydrolyzable organosilane is preferably 0.001 to 0.5 mol of water with respect to 1 mol of the hydrolyzable group. If the amount of water used is less than 0.001 mol, a sufficient partial hydrolyzate cannot be obtained, and if the amount of water used exceeds 0.5 mol, the stability of the partial hydrolyzate may be deteriorated. There is. The method of partial hydrolysis is not particularly limited, and a hydrolyzable organosilane and colloidal silica may be mixed and mixed with a necessary amount of water. At this time, the partial hydrolysis reaction proceeds at room temperature. In order to promote the partial hydrolysis reaction, it may be heated to 60 to 100 ° C. Furthermore, 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, toluene for the purpose of promoting partial hydrolysis reaction An inorganic acid such as sulfonic acid or oxalic acid or an organic acid may be used as a catalyst.

  The silica-dispersed oligomer of organosilane as component (G) has a liquid pH value in the range of 2.0 to 7.0, more preferably 2.5 to 6.5, in order to obtain long-term stable performance. It is better to adjust to a range of pH 3.0 to 6.0, even more preferably in the range of 3.0 to 6.0. When the pH value is out of this range, the long-term performance deterioration of the component (G) may be significant particularly when the amount of water used is 0.3 mol or more with respect to X1 mol. If the pH value of the component (G) is outside this range, the pH value may be adjusted by adding a basic reagent such as ammonia or ethylenediamine when the pH value is more acidic than this range. What is necessary is just to adjust pH value using acidic reagents, such as hydrochloric acid, nitric acid, and an acetic acid. The adjustment method is not particularly limited.

The (H) component silanol group-containing polyorganosiloxane used in the silicone-based inorganic paint (2) has an average composition formula represented by the above formula (8), and R ⁴ in the formula (8) is: it can be exemplified the same as ^{R 3} above (7) wherein 5 to 50 wt% in ^{R 4} is a phenyl group. If the phenyl group is less than 5% by weight, the elongation of the coating film is reduced and cracks are likely to occur, and if it exceeds 50% by weight, curing may be too slow. The other R ⁴ is preferably an alkyl group having 1 to 4 carbon atoms, a vinyl group, a γ-glycidoxypropyl group, a γ-methacryloxypropyl group, a γ-aminopropyl group, 3,3,3-trifluoropropyl. Substituted hydrocarbon groups such as groups, more preferably alkyl groups of methyl and ethyl groups. In the formula (8), d and e are numbers satisfying the relations 0.2 ≦ d ≦ 2.0, 0.0001 ≦ e ≦ 3, and d + e <4, respectively, and d is less than 0.2 or e is If it exceeds 3, there are disadvantages such as cracks in the cured film, and if d is more than 2 and 4 or less, or if e is less than 0.0001, curing does not proceed well.

  Such a silanol group-containing polyorganosiloxane (H) of the formula (8) is, for example, methyltrichlorosilane, dimethyldichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, or one or two alkoxysilanes corresponding thereto. The above mixture can be obtained by hydrolyzing with a large amount of water by a known method. In order to obtain a silanol group-containing polyorganosiloxane, when it is hydrolyzed by a known method using alkoxysilane, an unhydrolyzed alkoxy group may remain in a trace amount. That is, 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 molecular weight of the silanol group-containing polyorganosiloxane as the component (H) is preferably 700 to 20000. The molecular weight here is a weight average molecular weight in terms of standard polystyrene by GPC (gel permeation chromatography) measurement. When the molecular weight is less than 700, the curability of the formed coating film is slow and cracks are likely to occur. When it exceeds 20000, the coating film formed from the silicone-based inorganic paint (2) to which the pigment has been added has no gloss and may have poor smoothness.

  The curing catalyst of the component (I) used in the silicone-based inorganic paint (2) accelerates the condensation reaction between the component (G) and the component (H) and cures the coating. Examples of such catalysts include metal salts of carboxylic acids such as alkyl titanates, tin octylate and dibutyltin dilaurate, dioctyltin dimaleate; amine salts such as dibutylamine-2-hexoate, dimethylamine acetate, and ethanolamine acetate; Carboxylic acid quaternary ammonium salts such as tetramethylammonium acetate; amines such as tetraethylpentamine; N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropylmethyl Amine-based silane coupling agents such as dimethoxysilane; acids such as p-toluenesulfonic acid, phthalic acid and hydrochloric acid; aluminum compounds such as aluminum alkoxide and aluminum chelate; alkali catalysts such as potassium hydroxide; tetraisopropyl titanate; There are titanium compounds such as trabutyl titanate and titanium tetraacetylacetonate, and halogenated silanes such as methyltrichlorosilane, dimethyldichlorosilane, and trimethylmonochlorosilane. In addition to these, (G) component and (H) component There is no particular limitation as long as it is effective for the condensation reaction.

  The mixing ratio of the component (G) and the component (H) is 99 to 1 part by weight of the component (H) with respect to 1 to 99 parts by weight of the component (G), preferably 5 to 95 parts by weight of the component (G). In contrast, 95 to 5 parts by weight of component (H), more preferably 90 to 10 parts by weight of component (H) with respect to 10 to 90 parts by weight of component (G) (provided that component (G) and component (H)) Total amount of 100 parts by weight). When the component (G) is less than 1 part by weight, the room temperature curability is inferior and sufficient film hardness cannot be obtained. On the other hand, when the component (G) exceeds 99 parts by weight, the curability is unstable and a good film may not be obtained.

  Moreover, it is preferable that the addition amount of the curing catalyst of (I) component is 0.0001-10 weight part with respect to a total of 100 weight part of (G) component and (H) component. More preferably, it is 0.0005-8 weight part, Most preferably, it is 0.0007-5 weight part. If the addition amount of the curing catalyst (I) is less than 0.0001 parts by weight, it may not be cured at room temperature, and if the addition amount of the curing catalyst (I) exceeds 10 parts by weight, the heat resistance and weather resistance of the film may be reduced. It may get worse.

  A pigment, a matting agent, a filler, or the like may be added to the silicone-based inorganic paint (1) or (2) prepared as described above. Examples of pigments to be added include organic pigments such as carbon black, quinacridone, naphthol red, cyanine blue, cyanine green, and hansa yellow, titanium oxide, barium sulfate, petal, calcium carbonate, alumina, iron oxide red, and composite metal oxide. An inorganic pigment such as a product is good, and one or two or more selected from these groups can be used in combination. Among these, inorganic pigments are preferable for improving weather resistance. Moreover, silica powder, barium sulfate, etc. can be used as a filler, and it can be used combining 1 type (s) or 2 or more types chosen from the group enumerated above. The particle diameter of the pigment or filler is not particularly limited, but is preferably about 0.01 to 4 μm in average particle diameter.

  The amount of pigment added is not particularly limited because the concealability varies depending on the type of pigment, but in the case of an inorganic pigment, a range of 15 to 80 parts by weight with respect to 100 parts by weight of the resin solid content is preferable. When the amount is less than 15 parts by weight, the concealability cannot be sufficiently obtained, and when it exceeds 80 parts by weight, the smoothness of the coating film may be deteriorated. The pigment can be dispersed by an ordinary method, and a dispersant, a dispersion aid, a thickener, a coupling agent, and the like can be used at that time.

  An ultraviolet absorbing paint can be obtained by adding an ultraviolet absorbent to the silicone-based inorganic paint (1) or (2). Examples of ultraviolet absorbers include organic ultraviolet absorbers such as benzotriazole compounds such as 2 (2′hydroxy-5-methylphenyl) benzotriazole, benzophenone compounds such as 2,4-dihydroxybenzophenone, and particulate zinc oxide. And an inorganic ultraviolet absorber such as fine particle titanium oxide can be used, and an organic ultraviolet absorber and an inorganic ultraviolet absorber can be used in combination.

  The organic ultraviolet absorber can be relatively easily dispersed in the silicone-based inorganic paint (1) or (2). The addition amount of the organic ultraviolet absorber is not particularly limited, but is in the range of 0.1 to 30% by weight as the solid content with respect to the solid content of the silicone-based inorganic paint (1) or (2). Is preferred. If the addition amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 30% by weight, the color of the organic ultraviolet absorber becomes strong, which is not preferable.

  The addition amount of fine particle zinc oxide and fine particle titanium oxide, which are inorganic ultraviolet absorbers, is not particularly limited, but is 0.1 to 20 with respect to the solid content of the silicone-based inorganic paint (1) or (2). A range of% by weight is preferred. If the added amount is less than 0.1% by weight, the effect of improving the weather resistance due to UV cut becomes insufficient, and if it exceeds 20% by weight, it becomes cloudy white.

  Here, the ultraviolet absorber generally has a function of absorbing ultraviolet light and converting it into heat, and the organic ultraviolet absorber has a lifetime because this function is reduced over a long period of time. On the other hand, the lifetime of the inorganic ultraviolet absorber is semi-permanent, and it is preferable to use an inorganic ultraviolet absorber such as fine particle zinc oxide or fine particle titanium oxide as the ultraviolet absorber. However, fine particle zinc oxide and fine particle titanium oxide have poor dispersibility in the silicone-based inorganic paint (1) or (2), and agglomerate and the coating film becomes cloudy white. is there. In addition, fine zinc oxide and fine titanium oxide powders have a photocatalytic action. When an acrylic resin or alkyd resin having low weather resistance is used, the resin itself deteriorates and long-term storage stability cannot be obtained. For this reason, it is conceivable to use fine zinc oxide or fine particle titanium oxide dispersed in a solvent. However, fine zinc oxide or fine particle titanium oxide settles quickly in the solvent, and it is difficult to improve the dispersibility by this method.

On the other hand, in the hydrolyzable organosilane represented by the general formula (R ³ ) _n SiX _4-n used in the silica-dispersed oligomer solution of organosilane (G), fine zinc oxide and fine titanium oxide are easily dispersed. This dispersion is excellent in transparency and long-term storage stability. Therefore, it is preferable to use the hydrolyzable organosilane in a state in which fine particle zinc oxide or fine particle titanium oxide is added and dispersed. In addition to directly adding fine particle zinc oxide and fine particle titanium oxide to hydrolyzable organosilane, (R ³ ) _n SiX _4-n hydrolyzable organosilane was prepared by partial hydrolysis in colloidal silica (G ) The silica dispersion oligomer solution of organosilane may be dispersed by adding fine particle zinc oxide or fine particle titanium oxide, and this silica dispersed oligomer solution in which fine particle zinc oxide or fine particle titanium oxide is dispersed is used as a silicone-based inorganic paint. By adding to (1) or (2), it is possible to prepare a silicone-based inorganic paint blended with fine particle zinc oxide or fine particle titanium oxide. In this case, the particle size of the primary particles (non-aggregated particles) of fine particle zinc oxide or fine particle titanium oxide is preferably 0.01 μm to 0.5 μm, and the silica-dispersed oligomer solution of organosilane (G) Fine zinc oxide or fine titanium oxide can be dispersed up to about 200 parts by weight with respect to 100 parts by weight (when the amount exceeds 200 parts by weight, the viscosity increases and stirring becomes impossible). The dispersion can be performed using a general mixing apparatus such as a sand mill, a ball mill, or a paint shaker. At this time, an additive aid or filler may be added at a level that does not lower the weather resistance.

Next, in the present invention, as the inorganic paint for forming the photocatalyst-containing inorganic coating film 4, a silicone-based inorganic paint blended with a photocatalyst can be used. As this silicone type inorganic coating material, for example, those disclosed in Japanese Patent No. 2776259 can be used. That is,
General formula: Si (OR ¹ ) ₄ (9)
20 to 200 parts by weight of colloidal silica having an organic solvent dispersibility in which the silicon compound and / or colloidal silica is dispersed in a non-aqueous organic solvent,
General formula: R ² Si (OR ¹ ) ₃ (10)
100 parts by weight of a silicon compound represented by
General formula: R ² ₂ Si (OR ¹ ) ₂ (11)
In a proportion of 0 to 60 parts by weight (in the above formulas (9) to (11), R ¹ and R ² represent a monovalent hydrocarbon group),
Furthermore, a paint containing a photocatalyst can be used.

Each silicon compound has a general formula represented by the following formula (12).
General formula: R ² _n Si (OR ¹ ) _4-n (12)
(In formula (12), n = 0 to 3 is shown, and R ¹ and R ² are monovalent hydrocarbon groups.)
R ¹ and R ^{2 in} formula (12) are not limited as long as they represent a monovalent hydrocarbon group, but R ² represents a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms. For example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and other alkyl groups, cyclopentyl group, cyclohexyl group and other cycloalkyl groups, 2-phenylethyl group, 3-phenylpropylene. Halogens such as aralkyl groups such as ruthel groups, aryl groups such as phenyl and tolyl groups, anikenyl groups such as vinyl and allyl groups, chloromethyl groups, γ-chloropropyl groups, and 3,3,3-trifluoropropyl groups Examples thereof include substituted hydrocarbon groups and substituted hydrocarbon groups such as γ-methacryloxypropyl group, γ-glycidoxypropyl group, 3,4-epoxycyclohexylethyl group, and γ-mercaptopropyl group. Among these, an alkyl group having 1 to 4 carbon atoms and a phenyl group are preferable because of ease of synthesis or availability.

As R ¹ in the above formula (12), ^one having an alkyl group having 1 to 4 carbon atoms as a main raw material is used. In particular, tetramethoxysilane, tetraethoxysilane and the like are exemplified as the tetraalkoxysilane of n = 0, and methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane are exemplified as the organotrialkoxysilane of n = 1. , Phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane and the like. Further, examples of the n = 2 diorganodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, and the like, and n = 3 triorganoalkoxysilane. Examples thereof include trimethylmethoxysilane, trimethylethoxysilane, trimethylisopropoxysilane, dimethylisobutylmethoxysilane and the like.

R ¹ and R ^{2 in the} above formulas (9), (10), and (11) may be the same hydrocarbon group or different.

  Preparation of the silicone-based inorganic coating is, for example, diluting the silicon compound represented by the above formulas (9), (10), (11) with a solvent, adding water or a catalyst as a curing agent, hydrolysis, and 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 made 900 or more in terms of polystyrene. When the weight average molecular weight (Mw) is less than 900 in terms of polystyrene, curing shrinkage increases during the polycondensation reaction, and cracks are likely to occur in the dried inorganic coating film.

  The silicone-based inorganic paint can be used in combination with the silicon compound represented by the above formula (9), or alternatively, colloidal silica as a component. The colloidal silica is 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. The organic solvent-dispersible colloidal silica can be easily prepared by replacing the organic solvent with water. Examples of the organic solvent in which the colloidal silica is dispersed include, for example, 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 ethylene glycol derivatives, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent. In addition, the said compounding quantity of the said colloidal silica is a weight also including a dispersion medium.

  Water is generally used as a curing agent when preparing the silicone-based inorganic paint, and the amount of this water is preferably 45% by weight or less, more preferably 25% by weight or less in the silicone-based inorganic paint.

  Examples of the organic solvent used in preparing the silicone-based inorganic paint include lower aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol, ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoethyl acetate. Examples thereof include ethylene glycol derivatives such as ether, diethylene glycol derivatives such as diethylene glycol and diethylene glycol monobutyl ether, and diacetone alcohol. One or more of these are used. Furthermore, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl ethyl ketoxime, etc. can be used in combination with a hydrophilic organic solvent.

  When preparing the silicone-based inorganic paint, it is desirable that the pH of the silicone-based inorganic paint is 3.8-6. When the pH is within this range, the preservability of the silicone-based inorganic paint is good, and when it is outside this pH range, the period during which application can be performed is limited. The method for 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. In this case, an acid reagent such as hydrochloric acid may be added for adjustment. Depending on the pH, if the reaction progresses slowly with a small molecular weight, the reaction may be promoted by heating, or after the reaction is advanced by lowering the pH with an acidic reagent, a basic reagent is added. It may be a predetermined pH.

  And by making this silicone type inorganic coating material contain a photocatalyst, it can be used as a photocatalytic silicone type inorganic coating material. In general, titanium oxide is used as a photocatalyst, but in addition to 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, cobalt oxide, rhodium oxide, rhenium oxide, and the like. The blending amount of the photocatalyst is preferably in the range of 0.5 to 4% by weight with respect to the dry solid content of the silicone-based inorganic paint. When the blending amount of the photocatalyst is less than 0.5% by mass, the photocatalytic function cannot be sufficiently obtained even if the film thickness of the photocatalyst-containing inorganic coating film 4 is ensured. On the contrary, if the blending amount of the photocatalyst exceeds 4% by weight, the photocatalyst-containing inorganic coating film 4 may become cloudy and the design expression by the organic coating film 2 may be impaired.

  Therefore, when coating the cementitious board 1, first, sealer coating is performed as necessary. Sealer coating involves preheating and drying the cement-based board 1 with a preheater, passing the cement-based board 1 through the coating machine, applying a sealer paint to the surface of the cement-based board 1, passing it through the dryer and baking and drying it. Can be done.

  Then, as necessary, the cement-based board 1 coated with a sealer is passed through a preheater and preheated, and then an organic paint is applied through the coater, and this is passed through a dryer to be baked and dried. A coating film 2 is formed. Next, the cement-based board 1 on which the organic coating film 2 is formed is preheated by passing through a preheater, and then passed through a coating machine to apply a silicone-based inorganic paint, and this is passed through a dryer to be baked and dried. The inorganic coating film 2 is formed. Further, the cement-based plate 1 on which the organic coating film 2 and the inorganic coating film 3 are formed is passed through a preheating machine and then preheated, and then passed through a coating machine to apply a photocatalyst containing silicone inorganic coating, 4 is formed.

  As each of the above coating machines, various coating methods such as a brush coating method, a dipping method, a spray coating method, a roll coating method, a bell method, a flow coating method, a curtain coating method, and a knife coating method can be used. In order to easily obtain a coating film having a uniform thickness, a spray coater, a roll coater, or a bell coater using a rotating cup is preferred.

The coating amount of each coating material is not particularly limited, but the coating amount of the silicone-based inorganic coating material is preferably in the range of 3 to ²⁰ g / m ² by dry weight. When the coating amount of the silicone-based inorganic paint is less than 3 g / m ² , the effect of protecting the organic coating film 2 is low because the film thickness of the inorganic coating film 3 is too thin, and the organic coating film 2 may be deteriorated. . When the application amount of the silicone-based inorganic paint exceeds 20 g / m ² , a coating film crack occurs in the inorganic coating film 3, and in this case, the organic coating film 2 may be deteriorated. Moreover, it is preferable to set the application quantity of a photocatalyst containing silicone type inorganic coating material in the range of 0.4-1.2 g / m < ² > by dry weight. When the coating amount of the photocatalyst-containing inorganic coating is less than 0.4 g / m ² , the photocatalytic function cannot be sufficiently obtained. Conversely, when it exceeds 1.2 g / m ² , the photocatalyst-containing inorganic coating film 4 May become cloudy and the design expression by the organic coating film 2 may be impaired.

  Moreover, after apply | coating a silicone type inorganic coating material as mentioned above, when passing through a drier and heating and baking and drying, in this invention, the board temperature (surface temperature) of the cementitious board 1 is the temperature of 60-120 degreeC. The inorganic coating film 3 is formed by drying under a condition that the baking energy, which is the product of temperature (° C.) and time (second), is 5000 ° C. · sec or more. As described above, in the present invention, the drying conditions are defined by the baking energy (maturity) consisting of the product of the temperature of the cement-based plate 1 and the heating time. This baking energy is the amount of the plate temperature exceeding 60 ° C. It is calculated as the product of temperature and time. That is, the time is the time from when the surface temperature of the cementitious board 1 exceeds 60 ° C., and the temperature is the temperature obtained by subtracting 60 ° C. from the surface temperature of the cementitious board 1. The product is the burning energy. Here, if the plate temperature of the cement-based plate 1 at the time of drying is less than 60 ° C., drying may be insufficient even if it takes a long time, and if the plate temperature exceeds 120 ° C., There exists a possibility that the performance of the inorganic coating film 3 may deteriorate by an effect | action. Therefore, the temperature condition at the time of drying needs to be in the range of 60 to 120 ° C., and the baking time is adjusted according to the temperature so that the baking energy becomes 5000 ° C. · sec or more. is there. For example, when the surface temperature of the cementitious board 1 is 100 ° C., the drying time is set to 125 sec or more. The upper limit of the baking energy is not particularly set, but if excessive baking energy is applied, there is a risk of coating film cracking due to drying shrinkage of the cementitious board 1, so that the upper limit is practically about 20000 ° C. · sec. It is.

  Thus, the inorganic coating film 3 can be sufficiently baked and hardened by forming the inorganic coating film 3 by drying the coating film of the silicone-based inorganic paint at a baking energy of 5000 ° C. · sec or more. In forming the photocatalyst-containing inorganic coating film 4 by applying the photocatalyst-containing silicone-based inorganic paint on the inorganic coating film 3, there is no mixing at the layer interface between the inorganic coating film 3 and the photocatalyst-containing inorganic coating film 4. The effect of the photocatalyst in the photocatalyst-containing inorganic coating 4 can be sufficiently exhibited, the antifouling property by the photocatalyst can be obtained, and the organic coating 2 can be prevented from being deteriorated by the action of the photocatalyst. Is. If the baking energy is less than 5000 ° C. · sec, the inorganic coating film 3 is insufficiently baked and solidified, and when the photocatalyst-containing silicone-based inorganic paint is applied thereon to form the photocatalyst-containing inorganic coating film 4 The inorganic coating film 3 is dissolved in the solvent in the photocatalyst-containing silicone-based inorganic paint, and the photocatalyst contained in the photocatalyst-containing silicone-based inorganic paint is embedded in the layer of the inorganic coating film 3, The photocatalyst embedded in the inorganic coating 3 may cause deterioration of the organic coating 2 thereunder, and the amount of photocatalyst in the photocatalyst-containing inorganic coating 4 may be insufficient, leading to insufficient photocatalysis. There is.

  Further, in applying the photocatalyst-containing silicone-based inorganic paint as described above, in the present invention, after forming the inorganic coating film 3, the cement-based plate 1 is passed through a preheater so that the plate temperature becomes 80 ° C. or higher. After preheating, the photocatalyst-containing silicone-based inorganic paint is applied through a coating machine. By preheating the cement-based plate 1 so that the plate temperature becomes 80 ° C. or higher, the cement-based plate 1 retains high-temperature heat even after the photocatalyst-containing silicone-based inorganic paint is applied. The photocatalyst-containing silicone-based inorganic paint can be baked and dried with this heat of the cement-based plate 1. In the process of applying the cement-based board 1, the process of applying the photocatalyst-containing silicone-based inorganic paint is the final process, so after applying the photocatalyst-containing silicone-based inorganic paint, it can be left as it is. Yes, for example, when the preheating temperature of the cementitious board 1 is 80 ° C., the cementitious board 1 maintains a temperature of 50 ° C. or more even after being left to stand for about 80 seconds after applying the photocatalyst-containing silicone inorganic coating. Yes. Accordingly, a baking energy of 5000 ° C. · sec or more after applying the photocatalyst-containing silicone-based inorganic paint can be secured, and the photocatalyst-containing inorganic coating film 4 can be sufficiently baked and hardened. In this way, by preheating the cement-based plate 1 to a plate temperature of 80 ° C. or higher, it is possible to form the photocatalyst-containing inorganic coating film 4 without using a dryer for drying the photocatalyst-containing inorganic paint. Is. The upper limit of the preheating temperature is not particularly limited, but if the temperature is excessively high, drying shrinkage may occur in the cement-based plate 1 or heat deterioration may occur in the organic coating film 2 or the inorganic coating film 3. Therefore, practically, the upper limit is about 180 ° C. × 10 minutes.

  Next, the present invention will be specifically described with reference to examples.

(Preparation of organic paint)
An organic paint was prepared by blending an iron oxide pigment in a core-shell type acrylic emulsion paint (manufactured by Kansai Paint Co., Ltd.) in a range of 0 to 70% in weight ratio to the total solid content.

(Preparation of silicone-based inorganic paint)
100 parts by weight of methyltrimethoxysilane, 20 parts by weight of tetraethoxysilane, 150 parts by weight of isopropyl alcohol organosilica sol (“COSCAL 1432” manufactured by Catalytic Chemical Industry Co., Ltd., SiO ₂ content 30% by weight), 40 parts by weight of dimethyldimethoxysilane and Silicon alkoxide was prepared by mixing 100 parts by weight of isopropyl alcohol, adding 200 parts by weight of water and stirring the mixture, and adjusting the weight average molecular weight Mw to 1200 in a thermostatic bath at 60 ° C.

  The silicon alkoxide was blended with 13% by weight of zinc oxide as an ultraviolet absorber and 4% by weight of colloidal silica as a matting agent with respect to the total amount of solids to obtain a silicone-based inorganic paint. .

(Preparation of photocatalyst-containing silicone-based inorganic paint)
After mixing 100 parts by weight of methyltrimethoxysilane with 10 parts by weight of tetraethoxysilane, 90 parts by weight of IPA organosilica sol, 30 parts by weight of dimethyldimethoxysilane and 100 parts by weight of isopropyl alcohol (IPA), 90 parts by weight of water is added. And stirred. The weight average molecular weight Mw was adjusted to 1500 in a constant temperature bath at 60 ° C.

  Then, titanium oxide was added as a photocatalyst to the prepared liquid and stirred to obtain a photocatalyst-containing silicone-based inorganic paint. At this time, four types of photocatalyst-containing silicone-based inorganic coatings having a solid content concentration of the photocatalyst of 0.30 wt%, 0.50 wt%, 3.00 wt%, and 4.00 wt% were prepared.

(Example 1)
The organic paint was applied to the surface of the cement-based plate 1 having a plate thickness of 18 mm by a spray method and baked at 150 ° C. for 5 minutes to form an organic coating film 2 having a thickness of 30 μm.

Next, after preheating the cement-based board 1 to a plate temperature of 40 ° C., the above-mentioned silicone-based inorganic paint is applied on the organic coating film 2 by a spray method at a dry coating amount of 7.8 g / m ² . The inorganic coating film 3 was formed by passing through a drier having an atmospheric temperature of 180 ° C. for 120 seconds and baking and drying so that the baking energy was 5000 ° C. · sec.

Further, after preheating the cement-based plate 1 to a plate temperature of 81 ° C., 1.3 g / m of the photocatalyst-containing silicone-based inorganic paint having a photocatalyst solid content concentration of 4.00% by weight on the inorganic coating film 3. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² and leaving it as it is.

(Example 2)
An inorganic coating film 3 was formed in the same manner as in Example 1 except that the dry coating amount of the silicone-based inorganic paint was changed to 7.4 g / m ² .

Further, after preheating the cement-based plate 1 to a plate temperature of 80 ° C., the photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.50% by weight on the inorganic coating film 3 is 0.5 g / m. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² and leaving it as it is.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

(Example 3)
In addition to changing the dry coating amount of the silicone-based inorganic paint to 7.4 g / m ² , passing it through a dryer with an atmospheric temperature of 180 ° C. for 300 seconds, changing the baking energy to 15000 ° C. · sec, and baking and drying. Formed an inorganic coating film 3 in the same manner as in Example 1.

In addition, after preheating the cement-based plate 1 to a plate temperature of 97 ° C., a photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 3.00% by weight on the inorganic coating film 3 is 1.0 g / m. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² and leaving it as it is.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

Example 4
In addition to changing the dry coating amount of the silicone-based inorganic paint to 8.5 g / m ² , passing it through a dryer with an atmospheric temperature of 180 ° C. for 300 seconds, changing the baking energy to 15000 ° C. · sec, and baking and drying. Formed an inorganic coating film 3 in the same manner as in Example 1.

Further, after preheating the cement-based plate 1 to a plate temperature of 80 ° C., 1.0 g / m of the photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.30% by weight on the inorganic coating film 3. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² and leaving it as it is.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

(Comparative Example 1)
Inorganic coating film 3 in the same manner as in Example 1 except that it was passed through a dryer having an atmospheric temperature of 150 ° C. for 300 seconds, and the baking energy of the silicone-based inorganic paint was changed to 8000 ° C. · sec. Formed.

Further, after preheating the cement-based plate 1 to a plate temperature of 40 ° C., a photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.50% by weight on the inorganic coating film 3 is 1.0 g / m. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² , and then baking and drying at a temperature of 150 ° C. for 120 seconds.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

(Comparative Example 2)
In addition to changing the dry coating amount of the silicone-based inorganic paint to 7.4 g / m ² , passing it through a dryer with an atmospheric temperature of 180 ° C. for 60 seconds, changing the baking energy to 3000 ° C. · sec, and baking and drying. Formed an inorganic coating film 3 in the same manner as in Example 1.

In addition, after preheating the cement-based plate 1 to a plate temperature of 40 ° C., 0.8 g / m of the photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.50 wt% on the inorganic coating film 3. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² , and then baking and drying at a temperature of 150 ° C. for 120 seconds.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

(Comparative Example 3)
After preheating the cement-based board 1 to a plate temperature of 60 ° C., the above-mentioned silicone-based inorganic paint is applied onto the organic coating film 2 by a spray method at a dry coating amount of 6.3 g / m ² , and the ambient temperature is An inorganic coating film 3 was formed by passing through a dryer at 180 ° C. for 300 seconds and baking and drying so that the baking energy was 15000 ° C. · sec.

Further, after preheating the cement-based plate 1 to a plate temperature of 60 ° C., 0.9 g / m of a photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.50 wt% on the inorganic coating film 3. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² , and then baking and drying at a temperature of 150 ° C. for 120 seconds.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

(Comparative Example 4)
After preheating the cement-based board 1 to a plate temperature of 60 ° C., the above-mentioned silicone-based inorganic paint is applied onto the organic coating film 2 by a spray method at a dry coating amount of 6.3 g / m ² , and the ambient temperature is An inorganic coating film 3 was formed by passing through a dryer at 180 ° C. for 300 seconds and baking and drying so that the baking energy was 15000 ° C. · sec.

Further, after preheating the cement-based plate 1 to a plate temperature of 60 ° C., 0.9 g / m of a photocatalyst-containing silicone-based inorganic paint having a solid content concentration of 0.50 wt% on the inorganic coating film 3. ^The photocatalyst-containing inorganic coating film 4 was formed by coating by a spray method at a dry coating amount of ² and leaving it as it is.

  Others were carried out similarly to Example 1, and the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 were coated on the surface of the cement board 1.

  About the cement-type decorative board of Examples 1-4 and Comparative Examples 1-4 which performed the coating of the organic coating film 2, the inorganic coating film 3, and the photocatalyst containing coating film 4 as described above, coating film adhesion, photocatalytic function, The weather resistance was tested and the appearance was evaluated. The results are shown in Table 1.

  The coating film adhesion was tested in accordance with JIS K5600-5-6 by applying a 1 mm square crosscut to the coating film, and classifications 0 and 1 were “◯”, 2 was “Δ”, and 3-5. Was evaluated as “×”.

The test of the photocatalytic function was performed by irradiating a cement-type decorative board with a black light manufactured by Toshiba Corporation at an illuminance of 1.0 ± 0.05 mW / cm ² for 96 hours, and then a static contact angle measuring device (DM700 manufactured by Kyowa Interface Science) The contact angle of water was measured, and a contact angle of 10 ° or less was evaluated as “◯”, a contact angle of 40 ° or less as “Δ”, and a contact angle of 40 ° or more as “X”.

  As for weather resistance, after a 5000-hour test using a sunshine weatherometer, the appearance of the coating film on the cement-based decorative board was visually observed. “X” indicates a significant change, “△” indicates a slight change, Change was evaluated as “◯”.

  As shown in Table 1, each of the silicone inorganic paints was dried with a baking energy of 5000 ° C. · sec or more, and preheated to a plate temperature of 80 ° C. or more to apply the photocatalyst-containing silicone inorganic paint. In the example, an excellent coating film performance can be obtained without heating for drying after the application of the photocatalyst-containing inorganic paint. However, in Example 4, the photocatalyst function was insufficient because the photocatalyst content in the photocatalyst-containing silicone-based inorganic paint was small.

  On the other hand, as can be seen from the comparison between Comparative Examples 1 to 3 and Comparative Example 4, when the preheating temperature before applying the photocatalyst-containing silicone-based inorganic paint is low, heating for drying after application of the photocatalyst-containing inorganic paint is performed. It was impossible to obtain sufficient coating film performance unless

It is the schematic which shows a cement-type decorative board.

Explanation of symbols

1 Cement-based board 2 Organic coating 3 Inorganic coating 4 Photocatalyst-containing inorganic coating

Claims (4)

  In the coating method of a cement-type decorative board in which an organic paint, an inorganic paint, and a photocatalyst-containing inorganic paint are applied in this order on the surface of the cement-type board, the temperature of the board is 60 to 120 ° C. after applying the inorganic paint. Drying under a condition that the baking energy that is the product of temperature and time is 5000 ° C. · sec or more, and then applying a photocatalyst-containing inorganic coating to a cement-based board having a plate temperature of 80 ° C. or more. A method for painting cement-type decorative boards.   The method for coating a cement-type decorative board according to claim 1, wherein the content of the photocatalyst in the photocatalyst-containing inorganic paint is 0.5 to 4% by weight based on the dry solid content of the inorganic paint. The method for coating a cement-type decorative board according to claim 1 or 2, wherein the coating amount of the photocatalyst-containing inorganic paint is 0.4 to 1.2 g / m ² in terms of dry weight.   The method for coating a cement-type decorative board according to any one of claims 1 to 3, wherein the inorganic paint and the photocatalyst-containing inorganic paint are each a silicone-based inorganic paint.

Images