JPH0516280A - Coating article - Google Patents

Abstract

PURPOSE:To improve the surface performances of gloss, hardness, resistance to scuffing and the like without damaging the moisture absorption properties of a base by laminating the base, a film containing fine particles like inorganic oxide at the specified ratio and a curable film having permeability in this order. CONSTITUTION:Surface performances such surface gloss, surface hardness, resistance to scuffing and the like of a base are secured without damaging the moisture absorption performance of the base provided with moisture absorption properties by a coating article. The article is utilized as a humidity controller or a condensation preventing material for a building interior material or an indoor furnishing. In that case, the coating article is constituted by laminating a water-absorption base, a film containing 25wt.% of a particle-like inorganic oxide and a permeable curable film in said order. The average particle diameter of fine particles is set within the range of 1mum-200mum. The respective surface performances of the coating article are improved respectively by this arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated article having improved surface performance such as surface gloss, surface hardness and scratch resistance without impairing the moisture absorption performance of a substrate having a hygroscopic property.

[0002] For example, it is useful as a humidity control material and a dew condensation preventing material, as an interior building material or an interior furnishing product.

[0003]

2. Description of the Related Art Wood has a property of absorbing or releasing moisture in the atmosphere until it is in equilibrium with the humidity, that is, hygroscopicity. Due to this hygroscopic property, it becomes an interior building material that exerts a humidity control function of controlling indoor humidity. Moreover, since these woods are easily burned, it is now being sought to obtain a humidity control function for other building materials which are flame-retardant or non-combustible. As such a substitute material having a hygroscopic property in place of wood, there is a fibrous wood material or an inorganic building material containing stone, cement, lime, gypsum or the like as a component.

When these building materials having a hygroscopic property made of wood, wood materials, or inorganic materials are used as structural materials, their strength is lowered by containing water,
The water has various problems such as expansion due to freezing and cracking, or destruction of alkali-aggregate reaction as seen in concrete.
Therefore, hygroscopic building materials have generally been coated with the sole purpose of waterproofing.

At present, the most popular inorganic building materials having a hygroscopic property are natural Otani stone or artificial zeolite made from zeolite as a raw material.

As particularly seen in these, the material having a hygroscopic property is generally porous, has a large unevenness on the surface, is rough and has no surface gloss, and has a brittle surface.
Surface properties other than hygroscopicity, such as easy scratching, are very poor,
There is a need for a method that improves surface properties without compromising hygroscopicity. Therefore, coatings using various paints have been tried. However, although conventional paints have improved surface properties such as surface hardness and surface gloss, they are intended to be waterproof as described above, and therefore have reduced water absorption,
Or, there was a drawback that it would make it disappear completely. Further, it has been necessary to enhance the surface gloss of a substrate having large surface irregularities with the smallest possible coating liquid.

[0007]

DISCLOSURE OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of a hygroscopic material and improves other surface performances such as surface gloss, surface hardness and scratch resistance without impairing its hygroscopicity. To provide a coated article.

[0008]

The present invention has the following constitution in order to achieve the above object.

"A coated article comprising a substrate having a hygroscopic property, a coating film containing 25% by weight or more of finely divided inorganic oxide, and a curable coating film having a moisture permeability, which are laminated in this order." In the present invention, the hygroscopic base material includes a material containing wood as a main component, a material consisting of only an inorganic material not containing wood, and any material having hygroscopicity may be used. .

[0010] Wood-based materials include wood, wood materials such as plywood, fiber boards (hardboard, insulation board, particle board, etc.), wood sandwich boards, and wood wool and wood shavings. There are building materials such as wood wool cement board and wood chip cement board made of cement, and gypsum board made of plaster and sawdust.

As the material having only hygroscopicity and made of only inorganic material, stone, concrete composed of cement and aggregate (lightweight aggregate concrete, foam concrete, Autoclav
edLightweight Concrete), asbestos slate consisting of cement and asbestos, ceramic tiles, bricks, calcium silicate boards, or plastering materials such as cement mortar, gypsum plaster, and lime-based plaster. Although there are various names, abbreviations, and trademarks in the above building materials, here, the revised building materials handbook (supervised by Haruichi Kano, Chijin Shokan) and the building interior handbook (supervised by Saburo Teenda, Asakura Shoten) were followed. .

In the present invention, a naturally occurring zeolite stone (Otani stone) or an artificial stone made of artificially synthesized zeolite is expected to have a surface gloss and a resistance to moisture while the moisture control function of the substrate is expected to absorb moisture. It is a base material that is preferably used because it has particularly poor surface properties such as scratch resistance and surface hardness. Because zeolite is a common name, to be precise, according to Dictionary of Physics and Chemistry (Iwanami Shoten), the following general formula _{W m Z n O 2n · rH} 2 O ( wherein, W is, Na, Ca, K, Ba , Sr, and Z is Si + Al [Si / Al (atomic ratio)> 1],
r represents an arbitrary natural number. ) Is a hydrous silicate represented by.

In the present invention, the finely divided inorganic oxide is 25
The coating film containing at least% by weight is particularly effective in that the fine particles of the inorganic oxide are allowed to penetrate into the irregularities of the surface of the base material to smooth the surface. 25% by weight of finely divided inorganic oxide
As the fine particle inorganic oxide used in the coating film contained above, those having an average particle diameter of 1 to 200 mμ are usually preferably used, and those having a particle diameter of 5 to 100 mμ are more preferably used. If the average particle size exceeds 200 mμ, the surface smoothness is deteriorated, it is difficult to obtain a high gloss, and the surface gloss tends to be impaired. In addition, 1m
If it is less than μ, the stability tends to be poor and the reproducibility tends to be poor, and the moisture permeability may be lowered, or it may be absorbed in the substrate and the coating effect may not be sufficiently exhibited.

The component of such fine particle inorganic oxide is not particularly limited as long as it does not impair the transparency and achieves the purpose, but preferred examples are silica sol dispersed in colloidal form, Titania sol,
Examples thereof include zirconia sol, antimony oxide sol, alumina sol and the like. Particularly, colloidal silica or colloidal alumina is preferably used for improving hardness. It is also possible to use two or more sol together.

It is necessary for the coating film to contain 25% by weight or more of these particulate inorganic oxides. The particulate inorganic oxide may be 100% by weight. When the amount is less than 25% by weight, the effect provided on the substrate is not exerted, and on the other hand, as a component which can be used in combination with these finely divided inorganic oxides, it is possible to uniformly disperse the oxides and form a coating liquid. There is no limitation as long as it is stable and does not significantly impair moisture permeability, and specific examples include various acrylic resins, melamine resins, nylon resins, urea resins, silicones. Resins (including silane coupling agents and their hydrolysates), epoxy resins and the like can be used. Particularly, a resin soluble in hydroalcohol or the like is preferably used.

The coating amount of the coating liquid containing the particulate inorganic oxide is not particularly limited as long as it is an amount that prevents the curable coating having moisture permeability described below from penetrating into the substrate having hygroscopicity. , to represent the effect more remarkably, it is preferred that the amount of particulate inorganic oxide is 1g / m ² ~100g / m ² approximately. If it is less than 1 g / m ² , the effect is difficult to be exhibited,
If it exceeds 100 g / m ² , the smoothness improving effect tends to be poor.

As the sol preferably used as the particulate inorganic oxide, a water sol is preferably used, and alcohols, ketones, esters, ethers,
An organosol in which amides are replaced may be used. Further, a solvent such as various alcohols, ketones, dimethylformamide and dimethylsulfoxide may be used in combination with the water sol.

The sol is applied to the substrate by a spray method,
Various methods such as a dipping method, a bar coating method, and a flow coater method are possible, but in all cases, it is necessary to infiltrate and fill the irregularities on the surface of the substrate with the sol to smooth the surface. Further, after application, a curable coating composition having water permeability may be applied subsequently, but in order to make the effect more remarkable,
It is desirable to evaporate the solvent by drying to some extent, form a gel, and then apply a curable coating.

The moisture permeability of the curable coating having moisture permeability used in the present invention means that the water absorption of the curable coating is AS.
It means a water absorption / discharge property of 10% or more in a measurement based on TMD570 and that the water absorption rate is halved within one week at 23 ° C. in an absolutely dry state.

Examples of such a cured film having moisture permeability include poly (meth) acrylic acid salt, polyvinyl alcohol, poly (meth) acrylamide, polyalkylene oxide, poly (meth) acryloyl oligoalkylene oxide, polyhydroxyalkyl (meth). ) Synthetic polymers such as acrylate, and natural polymers such as carboxymethylated, starch obtained by hydrolyzing a nitrile group or an ester group, cellulose, and the like.

The method of cross-linking and curing is not particularly limited, but a cross-linking agent used in the cross-linking of polyvinyl alcohol described later is preferable. Further, it is possible to crosslink by adding a polyfunctional monomer, or to crosslink and cure by copolymerization with a monomer having an epoxy group, an amino group, an isocyanate group or the like. In this case, the polymerization method may be any of radical polymerization, cationic polymerization, and anionic polymerization, and may be either initiation by heat, or initiation by ultraviolet rays or electron rays or energy rays such as γ rays.

In particular, the curable film having moisture permeability in the present invention has a good balance of all performances such as durability, hardness, light resistance, moisture permeability, and chemical resistance.
Japanese Patent Application 1-319466, Japanese Patent Application 1-319467, Japanese Patent Application 1-319468
The coatings described in Japanese Patent Application No. Hei 1-319469 are preferably used.

That is, polyvinyl alcohol (component A) having a saponification degree of 70 mol% or more and an average polymerization degree of 300 or more,
A coating film made of a coating composition containing a crosslinking agent (component B) as a main component is preferably used. further,
For the purpose of further improving the moisture permeability, it is preferable that the obtained cured film is further subjected to a treatment selected from a surfactant treatment, an acid treatment, an alkali treatment and a wet heat treatment.

The polyvinyl alcohol used as the component A is obtained by partial hydrolysis or complete hydrolysis of polyvinyl acetate and has an average degree of polymerization (value determined according to JIS K 6726) of 300 or more, Polyvinyl alcohol having a hydroxyl group with a saponification degree (value determined according to JIS K 6726) of 70 mol% or more is preferably used in the present invention. When the average degree of polymerization is less than 300, the durability and water resistance tend to decrease, and the upper limit is preferably 3000 or less, preferably 3000.
When it is larger than the above range, the viscosity of the coating composition increases, and it may be difficult to obtain a smooth coating film. Further, when the saponification degree is 70 mol% or more, particularly excellent moisture permeability can be exhibited.

The cross-linking agent used as the component B is not particularly limited as long as it can make polyvinyl alcohol insoluble in water, and many known cross-linking agents can be used. As a specific cross-linking agent, epoxy resin,
Examples include melamine resins, silane coupling agents, various metal compounds, and urea resins.

Among the above-mentioned cross-linking agents, silane coupling agents are preferable from the viewpoint of many characteristics such as transparency, ease of cross-linking, hardness improvement and water resistance, and are particularly represented by the following general formula (I) or (II). A compound and its hydrolyzate are preferably used.

R ¹ _a R ² _b SiX _{4- (a + b)} (I)

[0028]

[Chemical 1]

(Wherein R ¹ , R ³ and R ⁵ are organic groups having an epoxy group and having ^{4 to} 14 carbon atoms, R ² , R ⁴ and R ⁶ are hydrocarbon groups having 1 to 14 carbon atoms, or A hydrocarbon group having 1 to 14 carbon atoms having a substituent selected from a halogen group, a mercapto group, a cyano group, a (meth) acryloxy group and an amino group, X and Q represent a hydrolyzable group.
c and e are 0 or 1 respectively, and b, d and f are 0, 1 or 2 respectively. Further (a + b),
(C + d) and (e + f) are 0, 1 or 2, respectively. Y is an organic group having 2 to 40 carbon atoms. ) In the general formula (I), aliphatic epoxy group such as glycidoxy group and examples of the epoxy group contained in R ^1, and alicyclic epoxy group such as 3,4-epoxycyclohexyl group and the like, R ¹ Is an organic group having 4 to 14 carbon atoms including these epoxy groups, and S is a monovalent organic group.
It is contained in the silane compound by the i-C bond. Further, R ² includes a hydrocarbon group having 1 to 14 carbon atoms such as a methyl group, an ethyl group, a vinyl group, a propyl group, an octyl group and a phenyl group, and a substituent derivative of these hydrocarbon groups. Examples of such a substituent include a halogen group such as a chloro group and a fluoro group, a mercapto group, a cyano group, a (meth) acryloxy group, and an amino group.
Like R ¹ , R ^{2 is} also a monovalent organic group and is contained in the silane compound through a Si—C bond. X is a hydrolyzable group, such as an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group, a carboxyl group such as an acetoxy group, a halogen group such as a chloro group and a bromo group, a methoxyethoxy group, an ethoxyethoxy group and the like. Examples thereof include an alkoxyalkoxy group, a ketoxime group and a propenyl group. Further, a is 0 or 1 and b
Is 0, 1 or 2. Furthermore, (a + b) is 0,
1 or 2. When b is 2, R ² may be the same or different.

Specific examples of the organosilicon compound represented by the general formula (I) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane,
Vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ
-Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrisilane Methoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxyethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrisilane Methoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane Orchid, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane,
α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane , Α-glycidoxybutyltrimethoxysilane, α-
Glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ- Glycidoxybutyltrimethoxysilane, δ
-Glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4
-Epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyl Tripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4 -Epoxycyclohexyl) propyltriethoxysilane,
Trialkoxysilanes such as δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, triacyloxysilanes or triphenoxysilanes or their hydrolysates and dimethyl Dimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane,
γ-methacryloxypropylmethyldimethoxysilane,
γ-methacryloxypropylmethyldiethoxysilane,
γ-mercaptopropylmethyldimethoxysilane, γ-
Mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane Silane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropyl Methyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyl Ludimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ- Glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane , Γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, etc. dialkoxysilane, diphenoxysilane or diacyloxy Orchids or a hydrolyzate thereof are examples.

On the other hand, in the compound represented by the general formula (II) which is another preferred silane coupling agent, R ³ and R ⁵ are R ¹ of the above general formula (I).
An example similar to can be given. Examples of R ⁴ and R ⁶ are the same as those of R ^{2 in the} general formula (I). Further, as the hydrolyzable group for Q, the same examples as for X in the general formula (I) can be given. Also,
c and e are 0 or 1 respectively, and d and f are 0, 1 or 2 respectively. Furthermore, (c + d), (e +
f) is 0, 1 or 2, respectively. d or f
When is 2, R ⁴ and R ⁶ may be the same or different.

Y is an organic group having 2 to 40 carbon atoms. That is, Y is a functional group contained in the molecule through two Si atoms and a Si—C bond, and the functional group contains a heteroatom other than carbon and hydrogen such as an oxygen atom and a nitrogen atom. There is no problem. Furthermore, within the range of 2 to 40 carbon atoms, the organic group may be chain-like or cyclic, and there is no problem even if an oxygen atom or the like is present as an epoxy ring or the like. In particular, when an oxygen atom or the like is present as an epoxy ring or the like, it is preferable because it contributes as a functional group during curing.

As a specific example of Y,

[0034]

[Chemical 2]

And the like.

Among the organosilicon compounds represented by the above general formula (I) or (II), it is preferable to use an organosilicon compound containing an epoxy group or a glycidoxy group especially for the purpose of improving low temperature curability and hardness. is there. In addition, from the viewpoint of curing speed and ease of hydrolysis, X and Q have 1 to 4 carbon atoms.
The alkoxy group or the alkoxyalkoxy group is preferably used.

Among these organosilicon compounds and / or their hydrolysates, hydrolysates are preferred in order to lower the curing temperature and promote crosslinking.

Hydrolysis is produced by adding pure water or an acidic aqueous solution such as hydrochloric acid, acetic acid or sulfuric acid and stirring. Furthermore, the degree of hydrolysis can be easily controlled by adjusting the amount of pure water or acidic aqueous solution added. At the time of hydrolysis, it is particularly preferable to add pure water or acidic aqueous solution in an equimolar or more and 3 times or less molar amount with respect to the X group or Q group of the general formula (I) or (II) from the viewpoint of promoting the curing.

Since alcohol and the like are generated during the hydrolysis, it is possible to perform the hydrolysis without a solvent. However, for the purpose of making the hydrolysis even more uniform, after mixing the organic silicon compound and the solvent, the hydrolysis is performed. It is also possible to disassemble. It is also possible to remove an appropriate amount of alcohol after hydrolysis under heating and / or reduced pressure for use depending on the purpose, and to add an appropriate solvent after that.

Examples of these solvents include water, alcohols, esters, ethers, ketones, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, and N, N-.
Examples thereof include dimethylformamide and dimethylimidazolidinone. Further, these solvents can be used as a mixed solvent of two or more kinds, if necessary. Also,
Depending on the purpose, it is possible to accelerate the hydrolysis reaction and further heat it to room temperature or higher in order to proceed with the reaction such as precondensation, or to lower the hydrolysis temperature to room temperature or lower to suppress precondensation. It goes without saying that it is also possible.

The addition ratio of the above-mentioned polyvinyl alcohol and the cross-linking agent should be optimized as appropriate depending on the desired moisture permeability and the substrate to which it is applied. In particular, the group for which the coating film of the present invention is to be provided. Heat resistance of material is 100 ℃
When the heat resistance is equal to or higher than the above, polyvinyl alcohol is added to 5 parts by weight with respect to 10 parts by weight of the crosslinking agent component.
It is preferably ˜300 parts by weight. Particularly, when both functions of high surface hardness and moisture permeability are simultaneously satisfied, the range of 7.5 to 150 parts by weight of polyvinyl alcohol is preferable with respect to 10 parts by weight of the crosslinking agent component.

The addition ratio in the case of adding the solvent should be appropriately optimized depending on the desired moisture permeability, the substrate to be applied, the coating method, etc., but it is easy to adjust the coating composition. Considering this, it is preferably 50 wt% or more in the composition.

Performance can be improved or modified by adding components other than the above components to the above-mentioned moisture-permeable curable coating.

For example, addition of fine particle silica or the like is preferably applied as the surface hardness improver.

In order to improve weather resistance and adhesion, the polyvinyl alcohol and various epoxy resins, urethane resins,
A combination of acrylic resins is preferred. Among them, the aliphatic type epoxy resin is particularly preferable because it can greatly improve the improvement effect.

Further, in the coating composition at the time of forming the coating film, various surfactants are used for the purpose of improving the flow at the time of coating, improving the smoothness of the coating film, and decreasing the friction coefficient of the coating film surface. In particular, a block or graft polymer of dimethylpolysiloxane and alkylene oxide, and a fluorine-based surfactant are effective. It is also easy to improve the practicality as a coating agent by dispersing dyes and pigments and fillers, dissolving an organic polymer to color the coating film, and improving coating properties, adhesion to base materials and physical properties. It is possible.

For the purpose of further improving weather resistance, it is possible to easily add an ultraviolet absorber or an antioxidant as a method for improving heat resistance deterioration. Furthermore, it is more preferable to add various flame retardants for making the substrate flame-retardant.

Further, various curing agents can be used in combination for the purpose of accelerating curing and curing at low temperature. As the curing agent, various epoxy resin curing agents or various organic silicon resin curing agents are used. Specific examples of these curing agents include various organic acids and their acid anhydrides, nitrogen-containing organic compounds, various metal complex compounds or metal alkoxides, and various salts such as alkali metal organic carboxylates and carbonates. Can be mentioned. These curing agents can be used as a mixture of two or more kinds.

Among these curing agents, the aluminum chelate compounds shown below are particularly useful in view of the stability of the coating composition and the presence or absence of coloring of the coating film after coating. The aluminum chelate compound here is, for example, an aluminum chelate compound represented by the general formula AlU _n T _3-n .

In the formula, U is OL (L is carbon number 1 to 6)
Of the general formula M ¹ COCH ₂
A ligand derived from a compound represented by COM ² (M ¹ and M ² are both lower alkyl groups having 1 to 6 carbon atoms), and a general formula M ³ COCH ₂ COOM ⁴ (M ³ and M ⁴ are both A lower alkyl group having 1 to 6 carbon atoms), which is at least one substituent selected from a ligand derived from a compound represented by
n is 0, 1 or 2. As the aluminum chelate compound represented by AlU _n T _3-n , various compounds can be mentioned, but aluminum acetylacetoacetate is particularly preferable from the viewpoint of solubility in the composition, stability, effect as a curing catalyst and the like. Aluminum bisethylacetoacetate monoacetylacetonate, aluminum-di-n-butoxide-monoethylacetoacetate,
Aluminum-di-iso-propoxide-monomethylacetoacetate and the like. It is also possible to use a mixture of two or more of these.

The coating in the coated article of the present invention is prepared by applying the above coating composition and then
The coating composition is cured, but the curing is performed by heat treatment. The heating temperature can be used in a fairly wide range, and a sufficiently good result can be obtained at 50 to 250 ° C.

The above-mentioned moisture-permeable curable coating containing polyvinyl alcohol and a crosslinking agent as main components has a hardness,
Although it has high adhesion, durability, chemical resistance and the like, it is preferable to perform surface treatment of the moisture permeable film in order to make it more practical in terms of moisture permeability. A preferable treatment method is a treatment at a temperature of 50 ° C. or higher and a relative humidity of 70% or higher for 0.5 minutes or longer and 5 hours or shorter. Temperature less than 50 ° C or humidity less than 70%,
Further, if the treatment time is less than 0.5 minutes, the improvement of the effect of the moisture permeation treatment will be insufficient. On the other hand, when the processing time exceeds 5 hours, there is a problem in terms of productivity. Further, the relative humidity is preferably 75% or more and 100% or less, and the temperature is 7% from the viewpoint of shortening the processing time.
More preferably, it is 5 ° C. or higher. These optimum treatment conditions are experimentally determined appropriately within the above range depending on the required moisture permeability, coating composition, and the like.

The film thickness of the curable coating film in the coated article in the present invention is not particularly limited, but from the viewpoint of improving the surface gloss, it is preferably 1 μm or more, and further, the surface hardness and workability. From the viewpoint of properties, it is preferably 1 mm or less.

As the method for applying the curable coating, methods used in ordinary application work can be used, and examples thereof include brush coating, dipping method, spin method, roll method, spray method, flow coating and curtain flow method. However, it is not particularly limited.

Further, the hygroscopic substrate of the present invention may be subjected to various chemical and physical treatments for the purpose of improving the adhesion and wettability with the coating film and the coating film. For example, the chemical treatment includes hot water immersion, solvent immersion, redox treatment, acid or alkali treatment, and the physical treatment is preferably plasma treatment, corona discharge treatment, ultraviolet irradiation, or the like.

The moisture-permeable curable coating of the coated article of the present invention can be colored by adding dyes or pigments without impairing its properties, and these produce a very high added value. Is. In particular, the pigment is effective for improving the design, and the addition of 0.3 to 40 wt% is preferably applied from the viewpoint of moisture permeability and colorability.
It is also possible to dye the curable coating.

The application of the coated article of the present invention is preferably used for the purpose of utilizing the hygroscopicity of the base material. For example, as a humidity control material and a dew condensation preventing material, a wood-based or inorganic wall, a ceiling, a flooring material, etc. It is useful as an interior furnishing product for building interior materials, musical instruments, furniture, ornaments, etc.

[0058]

The present invention will be described in more detail with reference to the following examples.

Example 1 (1) Preparation of γ-glycidoxypropyltrimethoxysilane hydrolyzate 236 g of γ-glycidoxypropyltrimethoxysilane was charged into a reactor equipped with a rotor, and the liquid temperature was 10 ° C. Keep at 0.01 and stirring with magnetic stirrer
54 g of a normal hydrochloric acid aqueous solution was gradually added dropwise. After completion of dropping, cooling was stopped to obtain a hydrolyzate of γ-glycidoxypropyltrimethoxysilane.

(2) Preparation of coating composition having moisture permeability Polyvinyl alcohol (product of Nippon Synthetic Chemical Industry Co., Ltd., AL-06 average degree of polymerization 600, degree of saponification 91.0-9
532 g of a 27.1 wt% aqueous solution (4.0 mol%) was weighed in a beaker, and then, while stirring, 62.4 g of the γ-glycidoxypropyltrimethoxysilane hydrolyzate.
And 1,4-dioxane 107.6 g, methanol 52.
4 g, dimethyl imidazolidinone 66.63 g, aluminum acetylacetone 3.6 g as a catalyst, and a fluorine-based surfactant 0.6 g were mixed and dissolved to obtain a composition.

(3) Infiltration and filling of sol on the surface of the base material As an inorganic oxide sol on the surface of the artificial zeolite plate, colloidal silica (“Snowtex N” (Nissan Chemical Industry Co., Ltd., particle size 10 to 20 μm, solid 20%)) was applied using a bar coater at 10 g / m ² (equivalent to pure silica particles) and then heated at 100 ° C. for 15 minutes, and then the substrate surface was dried. The average surface roughness of the base material before and after the application of the inorganic oxide sol was 80 μm before the application and 20 μm after the application (measured by a contact type surface roughness meter).

(4) Formation of a moisture-permeable cured coating The coating composition having moisture permeability prepared in (2) above is uniformly coated on the surface of the substrate of (3) at a rate of 500 g / m ² , and then for 20 minutes. After standing, it was dried with a hot air dryer at 140 ° C. for 2 hours. Then, steam blowing was performed for 3 minutes. Then, it was dried to obtain a coated article having a moisture permeable coating.

(5) Test Results The performance of the coated articles obtained was tested according to the following method. The results are shown in Table 1.

(B) Appearance The presence or absence of cracks in the coating film was visually observed.

(B) Using a steel wool having a hardness of # 0000, the coating film was rubbed to determine the scratch condition.

Criteria are as follows: A: Almost no scratches are produced even when strongly rubbed B: Slightly scratches are produced when strongly rubbed (C) 100 adhesive spots on the adhesive coating film that reach the substrate at 1 mm intervals Then, a cellophane adhesive tape (trade name "Cellophane tape" manufactured by Nichiban Co., Ltd.) was strongly adhered, and rapidly peeled in the direction of 90 degrees to examine whether or not the coating film peeled.

(D) Surface gloss The surface gloss was evaluated from the reflected light of the coated article.

(E) Hygroscopicity The surface was exposed to water vapor generated from a 40 ° C. water bath for 5 minutes and the state of dew condensation on the surface was observed.

Example 2 Example 1 was repeated except that the item (3) was changed as follows. That is, to 70 parts of the same colloidal silica as in Example 1, 30 parts of the γ-glycidoxypropyltrimethoxysilane hydrolyzate obtained in item (1) of Example 1 was added, and 2 parts of aluminum acetylacetone was added. Curing treatment was performed at 130 ° C. for 2 hours. The results are shown in Table 1.

Example 3 Example 3 was carried out in the same manner as Example 1 except that the item (3) was changed as follows. That is, instead of the colloidal silica of Example 1, methanol-dispersed colloidal silica (Nissan Chemical Industry Co., Ltd., particle size 10 to 20 mμ,
A solid content of 30%) was applied using a bar coat at 10 g / m ² (calculated as pure silica fine particles). The results are shown in Table 1.

Example 4 Example 1 was carried out in the same manner as Example 1 except that the item (3) was changed as follows. That is, the colloidal silica of Example 1 was mixed with 1: 1 alumina sol # 200 (Nissan Chemical Co., Ltd., average particle size 10 mμ × 100 mμ).
The same procedure as in Example 1 was carried out except that the mixed sol was mixed in the proportion of. The results are shown in Table 1.

Comparative Example 1 A coated article was obtained in the same manner as in Example 1 except that the colloidal silica of the item (3) was not applied. Sufficient smoothness and surface gloss were not obtained. The results are shown in Table 1.

Comparative Example 2 In Comparative Example 1, the thickness of the coating film was increased until the gloss of the moisture-permeable cured coating film was obtained. The coating amount is 2000 g / m ²
Was needed. The results are shown in Table 1.

Table 1 Appearance Hardness Adhesion Surface gloss Hygroscopicity Example 1 Good A Good Good Good Example 2 Good A Good Good Good Example 3 Good A Good Good Good Example 4 Good A Good Good Good Comparative Example 1 Bad B Good Poor Good Comparative Example 2 Good B Somewhat good Good Good

[0075]

The coated article obtained according to the present invention has the following effects.

(1) The surface performance such as surface gloss, surface hardness and scratch resistance can be improved without impairing the moisture absorption performance.

(2) A coating having good gloss can be obtained with a small amount of paint.

Claims (2)

[Claims] 1. A coated article comprising a substrate having a hygroscopic property, a coating film containing 25% by weight or more of a particulate inorganic oxide, and a curable coating film having a moisture permeability, which are laminated in this order. 2. The average particle size of the finely divided inorganic oxide is 1 mμ.
It is above 200mmicro, It is characterized by the above-mentioned.
A coated article as described.