JP2949793B2 - Coated articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention improves the surface performance such as surface gloss, surface hardness, and scratch resistance of a substrate having hygroscopicity without impairing its hygroscopic performance. Coated articles.

[Prior Art] Wood has a property of absorbing or dispersing moisture until it is always in equilibrium with the humidity in the atmosphere, that is, has a hygroscopic property. Due to this hygroscopicity, it becomes an interior building material exhibiting a humidity control function of adjusting the indoor temperature.

By the way, since wood is flammable, it has been increasingly required to provide a humidity control function to other fire-resistant or non-flammable building materials. Examples of such alternative materials having hygroscopicity in place of wood include wood materials made of wood chips and fibrous materials, and inorganic building materials containing stone, cement, lime, gypsum and the like as components.

When used as a structural material, these wood, woody materials, or inorganic building materials having hygroscopicity may decrease in strength due to the inclusion of moisture, or the moisture may expand due to freezing and cause cracking. And various problems such as breakage caused by alkali-aggregate reaction as seen in concrete. For this reason, hygroscopic building materials have one purpose of waterproofing,
It was common to be coated.

At present, as an inorganic building material having hygroscopicity, natural valley stone or artificial zeolite using zeolite as a raw material is most often used.

As particularly seen in these, hygroscopic materials generally have a brittle surface, are easily scratched, and have a rough surface without gloss, but the surface properties other than hygroscopicity are very poor, without impairing hygroscopicity. Thus, there has been a need for a method for improving the surface characteristics. For this reason, coating using various paints has been attempted. However, in the conventional coating, although the surface properties such as the surface hardness and the surface gloss of the base material are improved, the moisture absorption is lost at all because of the purpose of waterproofing as described above.

[Problems to be Solved by the Invention] The present invention has overcome the above-mentioned drawbacks of the hygroscopic material, and has improved other surface properties such as surface gloss, surface hardness, and scratch resistance without impairing its hygroscopicity. It is to provide a coated article.

[Means for Solving the Problems] The present invention has the following configurations to achieve the above object.

"A coated article comprising a moisture-permeable curable film provided on the surface of a moisture-permeable base material crosslinked by a silane coupling agent." There are a material containing wood as a main component and a material consisting only of an inorganic material not containing wood, but any material having a hygroscopic property may be used.

Wood-based materials include wood or wood materials such as plywood, fiberboard (hardboard, insulation board, particleboard, etc.), wood sandwich boards, and wood wool, wood chips and cement. There are building materials such as wood wool cement board, wood chip cement board, and gypsum board made of gypsum and sawdust.

Materials consisting only of hygroscopic inorganic materials include stone, concrete consisting of cement and aggregate (light-weight aggregate concrete, foam concrete, Autoclaved Lightweig
ht Concrete), asbestos slate made of cement and asbestos, ceramic tiles, bricks, tiles, and plastering materials such as cement mortar, gypsum plaster, and lime-based plaster. In the above building materials, there are various names, abbreviations, and trademarks, but here, the revised building materials handbook (supervised by Haruichi Kano, Jinjinshokan) and the building interior handbook (supervised by Saburo Toyoda, Asakura Shoten) .

In the present invention, a naturally occurring zeolite stone (Oya stone) or an artificial stone composed of an artificially synthesized zeolite is expected to have a surface gloss, abrasion resistance, The substrate is preferably used in that surface properties such as surface hardness are particularly poor. 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. ) It is a hydrous silicate represented by

The moisture permeability of the curable film having moisture permeability used in the present invention means that the water absorption of the curable film has a value of 10% or more as measured according to ASTM D570, and from this state, a 23 ° C absolute dry state. Means water absorption / desorption characteristics that the water absorption rate is reduced by half within one week.

Examples of such a cured film having moisture permeability include poly (meth) acrylate, polyvinyl alcohol, poly (meth) acrylamide, polyalkylene oxide, poly (meth) acryloyl oligoalkylene oxide, and polyhydroxyalkyl (meth) acrylate. Or a natural polymer such as starch or cellulose obtained by carboxymethylation or hydrolysis of a nitrile group or an ester group.

As a method of cross-linking and curing, a cross-linking method using a silane coupling agent used for cross-linking polyvinyl alcohol described below is used. It is also possible to crosslink by adding a polyfunctional monomer, and it is also possible to use epoxy groups, amino groups,
It is also possible to crosslink and cure by copolymerization with a monomer having 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 any of heat, ultraviolet light, or initiation by an energy beam such as an electron beam or γ-ray.

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

That is, a coating composed of a coating composition containing polyvinyl alcohol (component A) having a degree of saponification of 70 mol% or more and an average degree of polymerization of 300 or more and a crosslinking agent (component B) as main components is preferably used. Further, for the purpose of further improving 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.

Here, the polyvinyl alcohol used as the component A is obtained by partial or complete hydrolysis of polyvinyl acetate, and has an average degree of polymerization (JIS K 67
26), the degree of saponification (JIS K 6726)
Polyvinyl alcohol having a hydroxyl group of 70 mol% or more (a value obtained in accordance with the above) 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. A coating film may not be easily obtained. Further, when the saponification degree is 70 mol% or more, particularly excellent moisture permeability can be exhibited.

A silane coupling agent is used as a crosslinking agent used as the component B. A silane coupling agent is preferred from many aspects such as transparency, ease of cross-linking, improvement in hardness, and water resistance, and a compound represented by the following general formula (I) or (II), and a hydrolyzate thereof are particularly preferred. Used.

R ¹ _a R ² _b SiX _{4- (a + b)} (I) (Where R ¹ , R ³ , and R ⁵ each have 4 to 4 carbon atoms having an epoxy group)
14 organic groups, R ² , R ⁴ , R ⁶ are a hydrocarbon group having 1 to 14 carbon atoms,
Alternatively, a hydrocarbon group having 1 to 14 carbon atoms having a substituent selected from a halogeno group, a mercapto group, a cyano group, a (meth) acryloxy group and an amino group, and X and Q represent hydrolyzable groups. a, c, and e are each 0 or 1, and b, d, and f are each 0, 1, or 2. Further, (a + b), (c + d), and (e + f) are 0,
1 or 2. Y is an organic group having 2 to 40 carbon atoms. In the general formula (I), examples of the epoxy group contained in R ¹ include an aliphatic epoxy group such as a glycidoxy group;
An alicyclic epoxy group such as a 4-epoxycyclohexyl group and the like can be mentioned, and R ¹ is an organic group having 4 to 14 carbon atoms including these epoxy groups, and Si-C is a monovalent organic group. It is included in the silane compound by bonding. 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. As such a substituent, a chloro group,
A halogeno group such as a fluoro group, a mercapto group, a cyano group,
(Meth) acryloxy group and amino group. R ² also
Same as R ^1, a monovalent organic radical, are intended to be included in the silane compound in Si-C bonds. X is a hydrolyzable group, such as a methoxy group, an ethoxy group, an alkoxy group such as a butoxy group, a carboxy group such as an acetoxy group, a halogeno group such as a chloro group or a bromo group, a methoxyethoxy group, and an ethoxyethoxy group. 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. Further, (a + b) is 0, 1 or 2. When b is 2, R ² may be the same or different.

Specific representative examples of the organosilicon compound represented by the general formula (I) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, and methyltributoxy. Silane, ethyltrimethoxysila, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane,
Phenyltrimethoxysila, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane,
3,3,3-trifluoropropyltrimethoxysilane, γ-
Methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxyethoxysilane, γ-mercaptopropyltriethoxysilane, N- β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxy Methyltriethoxysilane, 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) ethyltripropoxysilane, β (3,4-epoxy Cyclohexyl) ethyltributoxysilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ-
Trialkoxysilanes, such as (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, trialcyloxy Silane or triphenoxysilanes or hydrolysates thereof and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-
Chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ- Aminopropylmethyldimethoxysilane,
γ-aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-gly Sidoxyethylmethyldiethoxycinran, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxy Propylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxy Examples thereof include silane, dialkoxysilane such as γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilane, diacyloxysilanes, and hydrolysates thereof.

On the other hand, in a compound represented by the general formula (II), which is another preferred silane coupling agent,
Examples of R ³ and R ⁵ are the same as those of R ^{1 in the} general formula (I). R ⁴ and R ⁶ are those represented by the general formula (I)
Can the same examples as R ² in. Examples of the hydrolyzable group for Q include the same examples as those for X in the general formula (I). Further, c and e are each 0 or 1, and d and f are each 0, 1 or 2. Further, (c + d) and (e + f) are 0, 1, or 2, respectively. When d or f 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 by two Si atoms and a Si—C bond. Even if the functional group contains a different atom other than carbon and hydrogen such as an oxygen atom and a nitrogen atom, No problem. Furthermore, within the range of 2 to 40 carbon atoms, the organic group may be in the form of a chain or a ring, 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, And the like.

Among the organosilicon compounds represented by the above general formulas (I) and (II), the use of an organosilicon compound containing an epoxy group or a glycidoxy group is particularly preferable for the purpose of improving low-temperature curability and hardness. X and Q are preferably alkoxy groups having 1 to 4 carbon atoms or alkoxyalkoxy groups in view of curing speed, ease of hydrolysis, and the like.

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

The hydrolysis is produced by adding pure water or an acidic aqueous solution of hydrochloric acid, acetic acid, sulfuric acid or the like, followed by stirring. Further, the degree of hydrolysis can be easily controlled by adjusting the amount of pure water or acidic aqueous solution. At the time of hydrolysis, at least equimolar to the X group or Q group of the general formula (I) or (II),
The addition of 3 times or less moles of pure water or an acidic aqueous solution is particularly preferred in terms of accelerating curing.

At the time of hydrolysis, alcohol and the like are generated, so it is possible to carry out hydrolysis without a solvent, but after mixing an organic silicon compound and a solvent for the purpose of performing hydrolysis more uniformly, hydrolysis is performed. It is also possible. Depending on the purpose, the alcohol or the like after the hydrolysis can be used after removing an appropriate amount under heating and / or reduced pressure, and then a suitable solvent can be added.

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

The addition ratio of the polyvinyl alcohol and the crosslinking agent for obtaining the moisture-permeable curable coating in the present invention should be appropriately optimized depending on the intended moisture permeability and the applied base material. When the heat resistance of the substrate on which the coating of the invention is to be provided has a heat resistance of 100 ° C. or more, or more than 10 parts by weight of the crosslinking agent component, the polyvinyl alcohol is 5 to 300 parts by weight. Is preferred. In particular, when simultaneously satisfying both functions of high surface hardness and moisture permeability, the amount of polyvinyl alcohol is preferably 7.5 to 150 parts by weight with respect to 10 parts by weight of the crosslinking agent component.

The addition ratio when the solvent is added should be appropriately optimized depending on the intended moisture permeability and the applied substrate, coating method, etc., but consider the ease of adjusting the coating composition. And it is preferably 50% by weight or more in the composition.

The performance can be improved or modified by adding components other than the above components to the coating of the coated article of the present invention.

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

In order to improve weather resistance and adhesion, it is preferable to use the polyvinyl alcohol in combination with various epoxy resins, urethane resins, and acrylic resins. Above all, aliphatic epoxy resins are particularly preferred because they can greatly improve the improvement effect.

Furthermore, various surfactants are used in the coating composition of the present invention at the time of forming the coating to improve the flow at the time of coating, improve the smoothness between coatings, and reduce the coefficient of friction of the coating film surface. In particular, a block or graft polymer of dimethylpolysiloxane and alkylene oxide, and a fluorine surfactant are effective. In addition, disperse dyes and pigments and fillers, dissolve organic polymers, and color the coating,
It is also possible to easily improve the practicality as a coating agent such as improvement in applicability, adhesion to a substrate, and physical properties.

Further, it is also possible to easily add an ultraviolet absorber or an antioxidant as a method for improving heat deterioration for the purpose of improving weather resistance.

In addition, various curing agents can be used in combination for the purpose of accelerating curing, curing at low temperature, and the like. 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 carboxylate and carbonate. No. These curing agents can be used as a mixture of two or more kinds.

Among these curing agents, from the viewpoint of the stability of the coating composition, the presence or absence of coloring of the coating film after coating,
Particularly, the following aluminum chelate compounds are useful. The aluminum chelate compound referred to here is, for example, an aluminum chelate compound represented by the general formula AlU _n T _3-n .

In the formula, U represents OL (L represents a lower alkyl group having 1 to 6 carbon atoms), and T represents a general formula M ¹ COCH ₂ COM ² (M ¹ and M ² each represent a lower alkyl group having 1 to 6 carbon atoms) A ligand derived from the compound represented by the general formula M ³ COCH ₂ COOM ⁴ (M ³ , M ⁴
Is at least one substituent selected from ligands derived from compounds represented by the formula (1), wherein n is 0, 1 or 2. As the aluminum chelate compound represented by AlU _n T _3-n , various compounds can be mentioned, and from the viewpoints of solubility in the composition, stability, and effect as a curing catalyst, aluminum acetyl acetoacetate is particularly preferable. And aluminum-bis-ethylacetoacetate monoacetylacetonate, aluminum-di-n-butoxide-monoethylacetoacetate, and aluminum-di-iso-propoxide-monomethylacetoacetate. These can be used as a mixture of two or more kinds.

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

The above-described curable film having moisture permeability having the above-mentioned polyvinyl alcohol and a cross-linking agent as main components is a material having high hardness, adhesion, durability, chemical resistance, etc.
In order to increase the practicality, it is preferable to perform any one of the following four processes.

First, the first treatment is immersion in an alkaline aqueous solution of 0.01 wt% or more and 40 wt% or less for 0.1 minute or more and 5 hours or less. If it is less than 0.01 wt% and less than 0.1 minute, it is difficult to obtain a sufficient moisture permeability effect, and if it exceeds 40 wt%, the adhesion between the film and the substrate is reduced. Processing for more than 5 hours is a production problem. Various aqueous solutions can be considered as the alkaline aqueous solution, and examples thereof include aqueous solutions of LiOH, KOH, NaOH, and ammonia. In particular, NaOH,
An aqueous solution of ammonia is preferred, and treatment at pH 8 or more is preferred. The concentration of the aqueous solution and the immersion treatment time are usually from 0.02 wt% to 20 wt%, and preferably from 0.2 minutes to 90 minutes. The aqueous solution to be immersed is preferably used at a temperature of 20 ° C. or higher from the viewpoint of shortening the processing time and the processing effect. These optimum processing conditions are appropriately determined experimentally within the above range depending on required moisture permeability, coating composition, and the like.

The second treatment involves immersion in an acidic aqueous solution of 0.01 wt% or more and 40 wt% or less for 0.5 minutes or more and 5 hours or less. If the processing conditions are less than 0.01 wt% or less than 0.5 minute, a sufficient improvement in the moisture permeability cannot be obtained. In addition, when the concentration exceeds 40 wt% or the processing time exceeds 5 hours, the film performance,
In particular, it reduces film adhesion. Various aqueous solutions are used as the acidic aqueous solution, and an aqueous solution having a pH of 5 or less is preferably used. Among them, HCl is most preferably used because it is easy to handle. The concentration of the aqueous solution and the duration of the immersion treatment are usually 0.01 wt% to 20 wt%, and are preferably performed in the range of 0.5 minute to 90 minutes. The aqueous solution to be immersed is preferably used at a temperature of 20 ° C. or higher from the viewpoint of shortening the processing time and the processing effect. These optimum processing conditions are appropriately determined experimentally within the above range depending on required moisture permeability, coating composition, and the like.

The third treatment is to add a surfactant of 0.1 wt% or more and 40 w
It is immersed in an aqueous solution containing t% or less for 0.5 minutes or more and 5 hours or less. If it is less than 0.1 wt%, the effect of improving moisture permeability is small, and if it exceeds 40 wt%, a large amount of surfactant remains on the treated surface, making removal by cleaning difficult. If the treatment time is less than 0.5 minutes, the moisture permeability effect is small, and if it exceeds 5 hours, there is a problem in productivity. Various surfactants can be considered as the surfactant, and examples thereof include a nonionic type, a cationic type, an anionic type, and an amphoteric type. Above all, the nonion type
It is particularly effective for moisture permeability at low temperatures. Specific examples of the surfactant include a silicone-based compound, a fluorine-based surfactant, and an organic-based surfactant. Particularly effective ones include sodium dodecylbenzenesulfonate, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and the like. The concentration of the aqueous solution and the immersion time are usually 0.1wt% ~ 20wt%
It is preferable to carry out within a range of 0.5 to 90 minutes. The aqueous solution to be immersed is preferably used at 50 ° C. or higher from the viewpoint of shortening the processing time and the processing effect. Further, in order to further enhance the effect, addition of an acid, a base or the like is preferably applied. These optimal processing conditions are the required moisture permeability,
It is appropriately set experimentally within the above range depending on the coating composition and the like.

The fourth process is a process in which the temperature is 50 ° C. or higher and the relative temperature is 70% or higher, for 0.5 minute or more and 5 hours or less. Temperature below 50 ° C or humidity 70
%, And when the treatment time is less than 0.5 minute, the effect of the moisture permeation treatment is insufficiently improved. On the other hand, if the processing time exceeds 5 hours, there is a problem in terms of productivity.
Further, the relative humidity is preferably not less than 75% and not more than 100%.
It is more preferable that the temperature is not lower than ° C. These optimum processing conditions are appropriately determined experimentally within the above range depending on required moisture permeability, coating composition, and the like.

By any of the above treatments, the intensity of the spectrum of the stretching vibration in the horizontal direction of the hydroxyl group within 1 μm from the surface of the moisture-permeable coating of the coated article of the present invention is increased by 0.3 or more than the intensity of the spectrum of the stretching vibration in the vertical direction. be able to. Here, the surface is a surface exposed to the outside air, and generally causes a dew condensation phenomenon and the like, and is a part which is particularly important for the function development as a moisture-permeable curable film. In addition, even in a film exceeding 1 μm from the surface, from the viewpoint of enhancing the anti-fogging property, the difference in spectrum intensity between the horizontal component and the vertical component of the stretching vibration of the hydroxyl group is 0.3 or more as in the surface layer portion. preferable.

The measurement of the horizontal component and the vertical component of the hydroxyl group can be performed using a commercially available FT-IR (Fourier transform infrared spectrophotometer) ATR device (total reflection absorption measuring device). For example, Biorad It can be measured with the polarization (P, S) spectrum measured by the Digilab FTS-15E / D type instrument,
This device was used in the present invention. In so-called P-polarized light, coupling perpendicular to the sample surface is excited, and in S-polarized light, coupling parallel to the sample surface is excited. Therefore, the absorption band intensity corresponding to these becomes strong, and the evaluation of the orientation,
It is possible to obtain knowledge and measure each component.

The above-described measurement is adopted because it is strongly measured that the measurement is performed at 3300 cm ^{−1 to} 3400 cm ⁻¹ , which is the absorption band of the stretching movement of the hydroxyl group, and there is no other obstructive absorption.

Furthermore, the intensity of the spectrum of the stretching vibration in the horizontal direction and the intensity of the spectrum of the stretching vibration in the vertical direction of the hydroxyl group are expressed using the peak at 1410 cm ⁻¹ which is the bending vibration spectrum of the methylene bond as a reference band. , The strength in the horizontal direction is 0.3 or more greater than the strength in the vertical direction, the horizontal direction of the hydroxyl group,
The quotient in the horizontal direction is obtained by dividing the absorption of the spectrum of the stretching vibration in each of the vertical directions by the absorption of each spectrum in the horizontal direction and the vertical direction at 1410 cm ⁻¹ ,
This means that the quotient in the vertical direction is 0.3 or more.

In the present invention, the thickness of the curable film in the coated article is not particularly limited, but is preferably 1 μm or more from the viewpoint of improving the surface gloss, and furthermore, such as surface luminosity and workability. From the viewpoint, it is preferably 1 mm or less.

As a method of applying the curable film, a method used in a normal application operation is possible, for example, brush coating, dipping method, spin method, roll method, spray method, flow coating, curtain flow method, and the like, There is no particular limitation.

Further, various chemical and physical treatments can be applied to the above-mentioned base material in order to improve the adhesion and wettability with the coating. For example, hot water immersion as a chemical treatment,
There are solvent immersion, oxidation-reduction treatment, acid or alkali treatment, etc., and preferable examples of the physical treatment include plasma treatment, corona discharge treatment, and ultraviolet irradiation.

In addition, as long as moisture permeability is not impaired, primer application to the surface of the substrate is also preferable from the viewpoint of improving the adhesion between the substrate and the coating. The primer in this case may be any primer as long as the moisture permeability is not impaired.

The coatings of the coated articles of the invention can also be colored by adding dyes and pigments without impairing their properties, which create very high added value. In particular, the pigment is effective for improving the design property, and the addition of 0.3 to 40% by weight is preferably applied from the viewpoint of moisture permeability and coloring property. It is also possible to dye the curable coating.

The use of the coated article of the present invention is preferably used in applications where the hygroscopicity of the substrate is utilized, and is useful as a building interior material such as a humidity control material and a dew condensation preventing material.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to 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 solution was kept at 10 ° C. With stirring with a stirrer, 54 g of a 0.01 N hydrochloric acid aqueous solution was gradually added dropwise. Stop cooling after dropping,
A hydrolyzate of γ-glycidoxypropyltrimethoxysilane was obtained.

(2) Preparation of paint 532 g of a 27.1% by weight aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., AL-06 average polymerization degree 600, saponification degree 91.0 to 94.0 mol%) was weighed in a beaker, and then stirred. 62.4 g of the γ-glycidoxypropyltrimethoxysilane hydrolyzate and 1,4-dioxane 10
7.6 g, methanol 52.4 g, dimethylimidazolidinone 66.
63 g, 3.6 g of aluminum acetylacetone as a catalyst,
0.6 g of a fluorinated surfactant was mixed and dissolved to obtain a paint.

(3) Formation of moisture-permeable cured film The paint prepared in the above (2) was coated on an artificial zeolite plate, allowed to stand for 20 minutes, and dried with a hot air drier at 140 ° C for 2 hours. Next, it was immersed in 10 wt% ammonia water at 40 ° C., and treated for 10 minutes. Thereafter, drying was performed to obtain a coated article made of artificial zeolite having a moisture-permeable coating.

(4) Test result The performance of the obtained coated article was tested according to the following method. The results are shown in Table 1.

(A) 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 surface of the coating film was rubbed to determine the degree of damage.

Judgment criteria are: A: hardly scratches even if strongly rubbed. B: slightly scratches when strongly rubbed. (C) Adhesiveness. A cellophane adhesive tape (trade name "Cellophane tape" manufactured by Nichiban Co., Ltd.) was strongly adhered, and quickly peeled off in the direction of 90 degrees to examine whether or not the coating film had peeled off.

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

(E) Hygroscopicity The film was exposed to water vapor generated from a hot water bath at 40 ° C. for 5 minutes, and the condensation on the surface was observed.

Comparative Example 1 An artificial zeolite plate having no coating was evaluated. The results are shown in Table 1.

Comparative Example 2 Acrylic paint (“KOTAX” LK-740 manufactured by Toray Industries, Inc. and a curing agent) was applied to an artificial zeolite plate, and dried with a hot-air dryer at 93 ° C. for 30 minutes to obtain a coated article. . Table 1 shows the evaluation results.

[Effects of the Invention] According to the present invention, it is possible to provide a coated article having improved surface performance, such as surface gloss, surface hardness, and scratch resistance, without impairing the hygroscopic performance of a substrate having hygroscopicity. it can.

Claims (1)

(57) [Claims] 1. A coated article comprising a hygroscopic substrate surface and a moisture-permeable curable coating crosslinked with a silane coupling agent.