JP2000109631A - Antifogging composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite material coated with a film excellent in antifogging properties and durability by coating the surface of a substrate with a specified hygroscopic coating composition. SOLUTION: This composite material is prepared by coating the surface of a substrate with a clear hygroscopic coating composition comprising a hybrid of an inorganic skeleton and organic molecules bonded thereto by crosslinking. The coating composition is prepared by mixing at least either an inorganic alkoxide or an OH-containing polymer formed by the hydrolytic polycondensation of the alkoxide with a water-absorbing organic polymer, a catalyst, and a water-containing organic solvent. It is desirable that the composite material has characteristics T and X in the ranges: 1/12<T×X/116,480C02, and 10-6<T<3×10-4 (wherein C0 is the concentration of a water vapor (kg water/m3 air), T is the film thickness (m), and X is the moisture absorption capacity (kg water/m3 film surface area), for example, under conditions of 0.003<C0<0.03 in a room (washroom mirror).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifogging composite material mainly used around water.

[0002]

2. Description of the Prior Art It is often experienced that in cold weather, windshields and windows of automobiles and other vehicles, window glasses of buildings, lenses of glasses, and cover glasses of various instrument panels are fogged by condensed moisture. In addition, mirrors and eyeglass lenses in bathrooms and washrooms are often fogged by steam. The reason why the surface of the article is fogged is that when the surface is placed at a temperature lower than the dew point in the atmosphere, moisture in the atmosphere condenses and condenses on the surface. If the condensed water droplets are sufficiently fine and their diameter is about half the wavelength of visible light, the water droplets will scatter light and the glass or mirror will appear opaque and lose visibility. If the condensation of moisture progresses further, and fine condensed water droplets fuse with each other and grow into larger discrete water droplets, the surface becomes dark due to the refraction of light at the water droplet-surface interface and the water droplet-air interface, Blurred or cloudy. As a result, in a transparent article such as glass, the perspective image is distorted and the transparency is reduced, and the reflected image is disturbed by a mirror. In addition, when windshields and windowpanes of vehicles, windowpanes of buildings, rearview mirrors of vehicles, lens of eyeglasses, shields of masks and helmets receive rain and splashes, and a large number of discrete water droplets adhere to the surface, the surface of those Is dark, blurred or cloudy,
Again, visibility is lost. As used herein, the term "anti-fog" broadly refers to a technique for preventing optical hindrance due to such fogging, growth of condensed water droplets, and adhesion of water droplets.

[0003]

[0003] Anti-fog technology has a profound effect on safety and efficiency of various operations. For example, if a windshield, a window glass, or a rearview mirror of a vehicle becomes cloudy or overshadowed, safety of the vehicle or traffic is impaired. Fogging of the endoscope lens and the dental dentoscope hinders accurate diagnosis, surgery, and treatment. When the cover glass of the instrument panel becomes cloudy, it becomes difficult to read the data. Conventionally used antifogging compositions consist of hydrophilic compounds such as polyethylene glycol. However, this kind of anti-fog composition is only temporary,
The disadvantage is that it is easily removed by water or contact and loses its effect early.

[0004] An object of the present invention is to provide a composite material coated with a hygroscopic coating composition capable of forming a coating film having excellent antifogging properties and durability. Another object of the present invention is to provide a composite material coated with a hygroscopic coating composition capable of forming an antifogging coating film that maintains the above antifogging property and durability performance for a long period of time. Another object of the present invention is to provide comfort in which the above-mentioned composite material is a mirror for washing, and fogging does not occur due to steam of hot water. Another object of the present invention is to provide a comfort in which the composite material is a mirror for a bathroom or a bathroom, and does not cause fogging due to steam of hot water.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a transparent material comprising a hybrid material in which an organic skeleton is crosslinked to an inorganic skeleton by coating the surface of a substrate with a hygroscopic coating composition. Provided is an antifogging composite material, which is coated with a hygroscopic coating composition. Further, the anti-fogging composite material is characterized in that the composition of the hygroscopic coating film is optimally selected within a limited range of material properties so as to function in an indoor washroom or bathroom environment. And

The surface of the anti-fogging composite material of the present invention has high hydrophilicity and hygroscopicity. When minute water droplets such as steam come into contact with the surface of the composite material, moisture does not condense on the surface. , Can prevent fogging. Further, in the antifogging composite material according to the present invention, the surface hygroscopic coating composition is composed of a hybrid substance in which organic molecules are crosslinked to an inorganic skeleton, and further, the base material and the surface hygroscopic coating composition are strongly bonded. Since they are bonded, they have excellent strength and durability, and can maintain the above antifogging performance for a long time.

BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the present invention is shown in FIG. 1 for the antifogging composite material according to the first aspect. The hygroscopic coating composition 1, which forms the surface layer of the anti-fogging composite material, forms a three-dimensional skeleton structure 3 having an inorganic portion and an organic portion, and incorporates a water-absorbing organic polymer into a gap therebetween. It is fixed by the adhesive strength of the skeleton. The water-absorbing organic polymer 4 contained in the three-dimensional skeleton 3 of the hygroscopic coating composition 1 has high water absorption, and when minute water droplets such as steam come into contact with the surface of the mirror, water is condensed on the surface. Instead, since the water-absorbing organic polymer 4 in the hygroscopic coating composition 1 forming the surface layer reaches and is absorbed, it is possible to prevent fogging and maintain the visibility of the reflection image. Further, the hygroscopic coating composition 1 is composed of an inorganic polymer and an organic polymer cross-linked and bonded to each other, and the surface layer of the composite material is covered with a highly durable film insoluble in water and an organic solvent. Become. A transparent intermediate layer may be provided between the substrate and the surface layer for the purpose of improving adhesion to the substrate and the like.
Further, the surface layer may be further coated with a porous hard coat film, thereby improving abrasion resistance and weather resistance and reducing reflected light.

[0008] The antifogging composite material according to claim 2 comprises a substrate surface coated with a hygroscopic coating composition, and the inorganic alkoxide and OH groups formed by hydrolysis and polycondensation of the alkoxide. The inorganic alkoxide used in the present invention, which is characterized in that it is coated with at least one kind of polymer having a water-absorbing organic polymer, a catalyst, and a hygroscopic coating composition containing a water-containing organic solvent, For example, it is at least one compound represented by the following formula (2). M (OR) n (X) a-n (2) where M is Si, Al, Ti, Zr, Ca, Fe,
V is an inorganic atom selected from the group consisting of Sn, Li, Be, B, and P, R is an alkyl group, X
Is an alkyl group, an alkyl group having a functional group, or a halogen, a is a valence of M, and n is 1
To a. Of the compounds of formula (2), n
= A, that is, a compound in which only an alkoxy group is bonded to M is widely used.

When M is Si, the alkoxide is
It is represented by Si (OR ₁ ) ₄ . Here, R1 is preferably a lower alkyl group having 1 to 4 carbon atoms. Such alkoxysilanes include Si (OCH ₃ ) ₄ , Si (OC
₂ H ₅ ) _{4 and the} like.

When M is Al, the alkoxide is
It is represented by Al (OR ₂ ) ₃ . Here, R ₂ is preferably a lower alkyl group. Such aluminum alkoxides include Al (OCH ₃ ) ₃ and Al (OC ₂ H ₅ )
₃ , Al (On-C ₃ H ₇ ) ₃ , Al (O-iso-C
₃ H ₇ ) ₃ and Al (OC ₄ H ₉ ) ₃ . The above-mentioned aluminum alkoxides may be used as a mixture of two or more kinds. Such an aluminum alkoxide is usually used by being mixed with the above-mentioned alkoxysilane, and the use of the aluminum alkoxide improves the light transmittance and heat resistance of the obtained coating film. The amount of the aluminum alkoxide to be used is preferably 10 parts by weight or less, more preferably about 5 parts by weight, based on 100 parts by weight of the alkoxysilane. If the amount exceeds 10 parts by weight, the formed polymer tends to gel,
Cracks may occur in the obtained coating film.

When M is Ti, the alkoxide is represented by Ti (OR ₃ ) ₄ . Here, R ₃ is preferably a lower alkyl group. Such titanium _{alkoxide, Ti (O-CH 3)} 4, Ti (O-C 2
_{H 5) 4, Ti (O} -n-C 3 H 7) 4, Ti (O-iso-C
_{3 H 7) 4, Ti (} O-C 4 H 9) 4 and the like. The titanium alkoxides may be used as a mixture of two or more. Such titanium alkoxides are usually
By using a titanium alkoxide mixed with the above-mentioned alkoxysilane, the UV resistance of the obtained coating film is improved and the heat resistance of the base material is also significantly improved. The amount of the titanium alkoxide to be used is within a range of 3 parts by weight or less, preferably about 1 part by weight, based on 100 parts by weight of the alkoxysilane. If it exceeds 3 parts by weight, the formed polymer becomes brittle, and the coating film tends to peel off when the substrate is coated.

When M is Zr, the alkoxide is represented by Zr (OR ₄ ) ₄ . Here, R ₄ is preferably a lower alkyl group. Such zirconium alkoxides include Zr (OCH ₃ ) ₄ and Zr (OC _{2
H 5) 4, Zr (O} -iso-C 3 H 7) 4, Zr (O-t-C
_{4 H 9) 4, Zr (} O-n-C 4 H 9) 4 and the like.
The zirconium alkoxides may be used as a mixture of two or more kinds. Such a zirconium alkoxide is usually used as a mixture with the above alkoxysilane,
By using the zirconium alkoxide, the toughness and heat resistance of the obtained coating film are improved. The amount of the zirconium alkoxide used is in the range of 5 parts by weight or less, preferably about 3 parts by weight, based on 100 parts by weight of the alkoxysilane. If the amount exceeds 5 parts by weight, the formed polymer tends to gel, the brittleness of the polymer increases, and the coating film easily peels off when the base material is coated.

Other alkoxides include, for example, Ca (OC ₂ H ₅ ) ₂ , Fe (OC ₂ H ₅ ) ₃ , V (O-
iso-C ₃ H ₇ ) ₄ , Sn (Ot-C ₄ H ₉ ) ₄ , Li (O
C ₂ H ₅ ), Be (OC ₃ H ₅ ) ₂ , B (OC ₂ H ₅ ) ₃ , P
(OC ₂ H ₅ ) ₂ and P (OCH ₃ ) ₃ .

In the case where n = a-1 or less among the inorganic alkoxides represented by the formula (2), that is, as a compound having a group X other than alkoxy bonded to M, for example, X
There are compounds that are halogens such as l, Br. A compound in which X is a halogen is hydrolyzed in the same manner as an alkoxy group to generate an OH group, and a polycondensation reaction occurs. X also
It may be an alkyl group or an alkyl group having a functional group, and the alkyl group usually has 1 to 15 carbon atoms. Such groups remain as organic moieties in the resulting polymer without hydrolysis. Examples of the functional group include a carboxyl group, a carbonyl group, an amino group, a vinyl group, and an epoxy group.

Compounds of the formula (2) having X include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- Aminopropylmethoxysilane and the like can be mentioned.

As the water-absorbing organic polymer used in the present invention, polyacrylic acids or polyalkylene oxides can be suitably used. The polyacrylic acid is at least one selected from polyacrylic acid, polymethacrylic acid, and salts thereof. Examples of the polyalkylene oxide include polyethylene oxide, polypropylene glycol, and polypropylene oxide, and polyethylene oxide is particularly preferable. Usually, a weight average molecular weight of 30,000 to 1,
500,000, preferably 500,000-750,
000 polyalkylene oxides are used. Further, as other water-absorbing organic polymers, poly 2-hydroxyethyl methacrylate, polyvinyl pyrrolidone,
Polyoxazolines, polyvinyl alcohols, ethylene vinyl alcohol copolymers, isobutylene maleic anhydride copolymers, polyacrylamides, polyoxyethylenes, polysaccharides and the like can be suitably used. Examples of the polysaccharide include viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and carboxymethylcellulose in the case of cellulosic. Examples of the polysaccharide include starches, such as soluble starch, carboxymethyl starch, and dialdehyde starch.
In addition to the water-absorbing organic polymer, 2-hydroxyethyl methacrylate monomer, sepiolite, silica gel, dextran, alginic acid, sodium alginate, carrageenan, agarose, kaolin, and the like can also be used.

The catalyst that can be used in the present invention includes a hydrolysis catalyst and a curing catalyst. The hydrolysis catalyst is used for a hydrolysis reaction of the inorganic alkoxide. Therefore, the inorganic alkoxide is hydrolyzed to some extent in advance,
When using polymers that are polycondensed and have OH groups (which can be relatively low molecular weight oligomers), a hydrolysis catalyst may not be necessary.

As the above-mentioned hydrolysis catalyst, hydrochloric acid, sulfuric acid,
A mineral acid such as nitric acid is used. Anhydrides of mineral acids, such as hydrogen chloride gas, may also be used. In addition, organic acids and their anhydrides can also be used. For example, tartaric acid, phthalic acid, maleic acid, dodecylsuccinic acid, hexahydrophthalic acid, methylnadic acid, pyromellitic acid, benzophenonetetracarboxylic acid, dichlorosuccinic acid, chlorendic acid, phthalic anhydride, maleic anhydride, Examples include dodecylsuccinic anhydride, hexahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, dichlorosuccinic anhydride, chlorendic anhydride, and the like. These acid catalysts
It is 0.01 to 0.5 part by weight, preferably 0.015 to 0.3 part by weight, based on 100 parts by weight of the alkoxide.
If the amount is less than 0.01 part by weight, the hydrolysis may be insufficient. If the amount exceeds 0.5 part by weight, the polycondensation reaction may proceed, and the viscosity may increase.

The curing catalyst is mainly used as a catalyst for a polycondensation reaction of a hydrolyzate of an alkoxide, and as a catalyst for a cross-linking reaction of a water-absorbing organic polymer.
It is used as a catalyst for a polycondensation reaction and / or a cross-linking reaction between the polymer having an OH group and the water-absorbing organic polymer. Such curing catalysts include 1,8-
At least one of diazabicyclo [5.4.0] undecene-7, quaternary phosphonium salt, organic amine, amino acid, metal acetylacetonate, organic acid metal salt, Lewis acid and peroxide can be suitably used. . Examples of the quaternary phosphonium salt include tetrakis (hydroxymethyl)
Examples include phosphonium chloride and tetrabutylphosphonium bromide. Examples of the organic amine include ethylamine, dimethylamine, N, N-dimethylamine, tributylamine, tri-n-propylamine, tripentylamine, tripropargylamine, N, N,
N-trimethylethylenediamine, n-hexylamine and the like can be mentioned. The amino acids include glycine and the like. Examples of the metal acetylacetonate include aluminum acetylacetonate, indium acetylacetonate, chromium acetylacetonate, titanium acetylacetonate, and cobalt acetylacetonate. In the metal acetylacetonate, preferably, aluminum acetylacetonate is used. Examples of the organic acid metal salt include sodium acetate, zinc naphthenate, cobalt naphthenate, zinc octylate, tin octylate, and the like. As the Lewis acid, stannic chloride, aluminum chloride, ferric chloride,
Titanium chloride, zinc chloride, antimony chloride and the like can be mentioned. Examples of the peroxide include hydrogen peroxide.
The amount of the curing catalyst used is preferably 0.01 to 2 parts by weight based on 100 parts by weight of the total amount of the alkoxide, the polymer having an OH group, and the water-absorbing organic polymer in the hygroscopic coating composition. More preferably, it is 0.
05 parts by weight. If the amount is more than 2 parts by weight, the polycondensation proceeds rapidly, making it difficult to dissolve in the following organic solvent, and the resulting coating film becomes non-uniform, so that the strength may decrease.

As the organic solvent used in the present invention, a solvent compatible with water, such as methyl alcohol, ethyl alcohol, isopropyl alcohol and butyl alcohol, is used. This organic solvent is used with water. The amount of the organic solvent used is preferably 100 to 500 parts by weight based on a total of 100 parts by weight of the alkoxide, the polymer having an OH group, the water-absorbing organic polymer and the basic catalyst.
0 parts by weight, more preferably about 3000 parts by weight.

The moisture-absorbing coating composition may further contain at least one water-absorbing inorganic composition. As the water-absorbing inorganic composition, sepiolite,
Silica gel and the like. Further, the hygroscopic coating composition may further contain at least one polyacrylic acid. Examples of the polyacrylic acids include polyacrylic acid, polymethacrylic acid, and salts thereof. The amount of the polyacrylic acid to be used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the hygroscopic coating composition. If the amount is less than 0.1 part by weight, the obtained composition may have a low water absorption speed, and if it exceeds 10 parts by weight, the obtained composition may be tacky. In particular, when the obtained composition is applied to a member having hardness, the polyacrylic acid is used as the hygroscopic coating composition 100.
It is preferable to use 0.1 to 0.5 parts by weight with respect to parts by weight. If it exceeds 0.5 parts by weight, the hardness of the film formed by the composition obtained may be low.

In the present invention, a fluorinated surfactant containing a hydrophilic group may be contained, and the surface of the antifogging composite material has a water- and oil-repellent portion derived from the fluorinated surfactant. And the hydrophilic part derived from the hygroscopic coating composition are microscopically dispersed. This makes it difficult for any lipophilic, hydrophobic or hydrophilic contaminants to adhere to the surface of the composite material, and even if it adheres, the adhesion is unstable and easily falls off, so that the surface is kept clean. Good water absorption can be maintained over a long period of time. Examples of the fluorine-based surfactant include a perfluoroalkyl carboxylate, a perfluoroalkyl ammonium salt, a perfluoroalkyl betaine, a perfluoroalkyl ethylene oxide adduct, a perfluoroalkyl group-containing oligomer, trifluoropropyl trichlorosilane, and trifluoropropyl trichlorosilane. Fluoropropylbromosilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, heptadecafluorooctyltrimethoxysilane, heptadecafluorooctyltriethoxysilane, and the like can be suitably used.

In the present invention, the hygroscopic coating composition may further contain a silver ion having a heat ray absorbing property.
It is possible to suppress an increase in the indoor temperature due to radiation such as sunlight.

Further, in the present invention, a heat ray absorbing material may be contained in the above-mentioned hygroscopic coating composition, and if it is used for a transparent material such as glass, the room temperature due to radiation such as sunlight can be reduced. The rise can be suppressed, and the temperature of the glass surface can be increased to make it difficult for water droplets to adhere. Silver ions can be suitably used as the heat ray absorbing material.

In the present invention, an ultraviolet absorber may be contained in the above-mentioned moisture-absorbing coating composition, and if it is used for a transparent material such as glass, it will block short-wavelength sunlight harmful to the human body. it can. Examples of the ultraviolet absorber include benzotriazole, benzophenone, salicylate, cyanoacrylate, oganilide,
Ce and the like.

In the present invention, an antifungal agent, an antibacterial agent or an insect repellent may be contained in the above-mentioned hygroscopic coating composition, so that the propagation of mold and bacteria can be prevented and prevented. As antibacterial and antifungal agents, sodium sulfonate, isothiazoline, benzoic acid,
-Oxybisphenoxyarsine, 2- (4-thiazolyl) -benzimidazole, N- (fluorodichloromethylthio) -phthalimide, 2-methylcarbonylaminobenzimidazole, silver, copper, zeolite, zirconium silver phosphate, silver hydroapatite , Silver phosphate glass, silver phosphate ceramic and the like.

Further, in the present invention, a fragrance may be contained in the above-mentioned moisture-absorbing coating composition, and when used in a vehicle or a building, it is possible to spend more comfortably. Examples of the fragrance include anise oil, abies oil, ylang-ylang oil, iris oil, fennel oil, oak moss, orange oil, cashmere oil, caraway oil, cayubute oil, cinnamon oil, jasmine flower essential oil, lemongrass oil, rose oil, and rose. Marie oil and the like.

According to the present invention, the antifogging composite material is formed, for example, as follows. First, the components of the hygroscopic coating composition are mixed to obtain a transparent to translucent coating liquid. Next, the coating liquid is applied to at least one surface of the base material, and is heated and dried at a temperature of 80 ° C. or more, preferably in a range of 120 ° C. to 200 ° C., thereby obtaining the antifogging composite of the present invention. The material is obtained. If necessary, the above heat treatment may be performed after the above coating liquid is applied several times.

In the hygroscopic coating composition, the inorganic alkoxide is hydrolyzed by the action of a hydrolysis catalyst, and the alkoxy group and halogen (X) are changed to OH groups. Furthermore, the OH group is deprotonated by the action of the curing catalyst, and as a result, the hydrolyzate starts polycondensation to form a polymer or oligomer having an OH group in the molecule. At the same time, the curing catalyst causes the OH group portion of the water-absorbing organic polymer present in the composition to react with the above-mentioned hydrolyzed alkoxide or the polymer or oligomer having an OH group, such as Si represented by M in the formula (2). Is formed, and a composite polymer having an organic portion derived from a water-absorbing organic polymer is formed. When the respective components of the composition are mixed, the hydrolysis reaction and the polycondensation reaction partially proceed as described above, so that the inorganic alkoxide, the hydrolyzate thereof, the polycondensation oligomer or polymer of the hydrolyzate, the water-absorbing organic compound, It is a colloidal sol in which the polycondensation or cross-linking reaction products of the polymer and the hydrolyzate derived from the alkoxide and the water-absorbing organic polymer are mixed. (2)
When X in the formula has a specific functional group, this functional group may further react. For example, when X is a group having an epoxy group, the epoxy group is opened by a base catalyst to generate an OH group, and the reaction with an alkoxide or a water-absorbing organic polymer proceeds. When X is a group having a vinyl group, a reactive monomer can be bonded to the vinyl group.

When such a coating composition is applied to a substrate and dried and then heat-treated at 80 ° C. or higher, the above-mentioned medium condensation reaction and crosslinking reaction proceed to form a composite polymer having a three-dimensional structure. You. This polymer is a polymer having an inorganic part and an organic part. That is, since this polymer has an insoluble skeleton that is an inorganic portion,
The coating formed by this polymer is insoluble in water and organic solvents and has a high surface hardness. Furthermore, since this polymer has a water-absorbing organic polymer that is an organic portion, a hydrophilic portion derived from the water-absorbing organic polymer is present on the surface of the formed film, and moisture is adsorbed to that portion. Further, a carbonyl group, a carboxyl group, an amino group, a vinyl group, an amino group,
When it has an epoxy group or the like, moisture is further adsorbed to the group.

When a polyacrylic acid is further added to the above-mentioned hygroscopic coating composition, the hygroscopic property of the obtained hygroscopic coating composition is improved.

The basic water-absorbing polymer functions as a catalyst for the polycondensation reaction of the hydrolyzate of the alkoxide and, at the same time, undergoes a polycondensation reaction and / or a crosslinking reaction with the polymer having an OH group. Examples of the basic water-absorbing polymer include methylene bisacrylamide (MBAA), poly (oxyethylene) dipropylamine, poly (oxyethylene)
Laurylamine and the like can be suitably used.

The base material of the antifogging composite material is not particularly limited, and may be, for example, metal, ceramics, glass, plastic, wood, stone, cement, concrete, fiber, cloth,
Combinations thereof and their laminates can be suitably used. The substrate may be determined in consideration of the use of the member.

In particular, the mirror base material may be a mirror made of a glass base material provided with a reflection coat on the back surface, a mirror made of a transparent plastic provided with a reflection coat on the back surface, or a base material made of plastic, glass, metal or the like. Mirrors with reflective coating, mirrors with plastic coating, glass, metal, etc., with a reflective coating on the surface of the substrate and a transparent hard coat on it, mirrors with a mirror-polished metal substrate, mirror-polished metal A mirror in which a transparent hard coat is provided on the surface of a mirror made of a base material, a mirror in which a transparent hard coat is provided on a transparent plastic base material in which a reflection coat is provided on the back surface, and the like can be suitably used.
A transparent intermediate layer may be provided between the substrate and the surface layer for the purpose of improving adhesion to the substrate and the like.

The antifogging composite material according to the present invention may be provided with a dryer including a heater and a blower. By providing a dryer in the vicinity of the anti-fogging composite material, the water absorbing ability of the hygroscopic coating composition is remarkably improved, and higher dew and anti-fogging effects can be obtained. In addition, by controlling the water absorption rate of the hygroscopic coating composition, the humidity of the atmosphere can be adjusted.

As for the hygroscopic coating of the surface layer of the anti-fogging composite material of the present invention, the optimum material composition for ensuring the required anti-fogging performance can be determined depending on the use environment. The required antifogging performance can be expressed by the antifogging function time, and if the environmental conditions are expressed by the water vapor concentration and the diffusion rate, the required film thickness and moisture absorption capacity as the material properties of the hygroscopic film are derived from the following relational expression. You. Therefore, an antifogging composite material capable of exhibiting sufficient antifogging performance particularly in a washroom or a bathroom is defined by material properties satisfying the following relational expression.

In general, the breakthrough time of the adsorption tower for the purpose of adsorbing water vapor in the atmosphere is set as follows with respect to the height of the adsorption layer, the packing density of the adsorbent, and the adsorption capacity.

The breakthrough time θ _B of the adsorbent layer is inversely proportional to the water vapor concentration C ₀ in the atmosphere in contact with the hygroscopic layer and the diffusion speed u of water vapor, and the height of the adsorbent layer Z _t , the packing density ρ _{B of the} adsorbent and proportional to the adsorption capacity x _0. That is, (3) θ _B = Z _t × ρ _B
A relationship of × x ₀ / (C ₀ × u) is set. Here, the unit of each variable is θ _B : hour, Z _t : m, ρ _B : kg / m ³
_Membrane , x ₀ : kg _water / kg _membrane , C ₀ : kg _water / m ³ _air , u:
m / hour.

For the anti-fogging composite material of the present invention, θ _B is used as the anti-fogging maintenance time, Z _t is used as the film thickness T, and (ρ _B × x ₀ ) is used as the moisture absorption capacity X using the equation (3). For example, the required hygroscopic performance of the surface hygroscopic film can be expressed by equation (4). However, the unit of moisture capacity X is, kg _water / m ³ _{film (4) θ B <T ×} X / 116480C 0 2

Here, when the hygroscopic composite material of the present invention is used as an indoor toilet mirror or bathroom mirror, θ _B
Are set to 1/12 or 1/2, respectively. In many cases, the toilet mirror becomes cloudy and unusable due to steam from hot water supplied to the vanity or water vapor from an adjacent bathroom. In the case of bathroom mirrors, the majority is due to steam from a bathtub or hot water from a shower. In each case, the excess water vapor is due to reach near the mirror,
Considering the maximum water vapor concentration expected in the bathroom or bathroom and a series of work, 30 minutes or more in the bathroom and 30 minutes in the bathroom
It is preferable to maintain the antifogging maintenance time of at least one minute.

The maximum water vapor concentration C0 assumed in the above-mentioned lavatory or bathroom is 0.003-0.
03, 0.006 to 0.055.

The moisture-absorbing coating on the surface of the antifogging composite material of the present invention preferably has a thickness T of 1 to 300 μm,
More preferably, it is 1 to 20 μm. Thickness T is 300μ
If it exceeds m, the transparency and strength of the film will be significantly reduced.
In consideration of the molding cost of the coating, 20 μm or less is reasonable. The moisture absorption capacity X of the hygroscopic film is represented by the amount of adsorbed water per unit volume, and the amount of saturated adsorbed water per unit area when water vapor is adsorbed at 30 ° C. until saturation is reached x
And the value obtained by dividing x by the film thickness T at the time of drying.

Accordingly, the material composition of the hygroscopic coating on the surface layer of the wash mirror or the bathroom mirror is (5)
Alternatively, it functions effectively in a range having material properties satisfying the expression (6). (5) 1/12 <T × X / 116480C 0 2 ^{_{However, 0.003 <C 0 <0.03,10 -}} 6 <T <3
^{× 10 - 4 (6) 1/2} <T × X / 116480C 0 2 ^{_{However, 0.006 <C 0 <0.055,10 -}} 6 <T <
3 × 10 ^{- 4}

With respect to the hygroscopic film of the surface layer of the antifogging composite material of the present invention, the material composition can be determined based on the optimum film thickness and hygroscopic capacity obtained from the equations (5) and (6). .
The film thickness is adjusted according to the concentration of the hygroscopic coating solution, liquid temperature and viscosity, addition of leveling agent, number of coatings, coating method such as roll coating, curtain flow coating, dipping, and flow rate of mirror during film formation. can do. In addition, regarding the moisture absorption capacity, hydrolysis-crosslinking conditions and composition ratio of the hygroscopic coating composition, type of inorganic skeleton, type and degree of polymerization of water-absorbing polymer, addition of hygroscopic additives such as surfactants, and drying The heating temperature and time can be adjusted.

[0045]

Example 1 Preparation of Hygroscopic Coating Liquid-1 Water-absorbing coating liquid-1 was prepared according to the components (parts by weight) shown in Table 1. First, polyacrylic acid 25
A polymer solution 1 was prepared by mixing a wt% aqueous solution and methanol and stirring and dissolving at room temperature for 10 minutes. Next, a binder solution 1 was prepared. First, a 2N aqueous hydrochloric acid solution, aluminum isopropoxide, and ethanol were mixed and stirred at room temperature for one day. Then, tetraethoxysilane 4
A monomer (ethyl silicate 40, manufactured by Colcoat Co., Ltd.) and a silane coupling agent (product name: KBM403, manufacturer Shin-Etsu Silicone, chemical name: γ-glycidoxypropyltrimethoxysilane) were mixed and stirred at room temperature for 10 minutes. Then, after sufficiently hydrolyzing the tetraethoxysilane, diethylamine is added, and the mixture is added at room temperature for 1 hour.
The mixture was stirred for 0 minute to prepare a binder composition 1. The polymer solution 1 and the binder composition 1 were mixed and stirred at room temperature for 10 minutes to prepare a hygroscopic coating solution 1. The resulting liquid was a clear and viscous solution.

[0046]

[Table 1]

Preparation of Hygroscopic Coating Liquid-2 In accordance with the components (parts by weight) shown in Table 2, the hygroscopic coating liquid-2 is prepared. First, polyvinyl alcohol (polymerization degree: 1500 to 1800) was poured into water, and the polymer solution 2 was prepared by slowly cooling while stirring in a 90 ° C. atmosphere for 3 hours. Next, a binder solution is prepared. First, 2
A wt% nitric acid aqueous solution and aluminum isopropoxide were mixed and stirred at room temperature for one day. Then, ethanol, tetraethoxysilane tetramer (trade name; ethyl silicate 40, manufactured by Colcoat) and silane coupling agent (brand name: KBM403, manufactured by Shin-Etsu Silicone Co., Ltd.) were added to a 2N hydrochloric acid aqueous solution and aluminum isopropoxide mixed solution. Name: γ-glycidoxypropyltrimethoxysilane) and stirred at room temperature for 10 minutes. After sufficiently hydrolyzing the tetraethoxysilane, 1,8-diazabicyclo (5.4.0) undecene-7 was added thereto, and the mixture was stirred at room temperature for 10 minutes to prepare a binder liquid. The polymer solution and the binder solution were mixed in the same manner as described above, and stirred at room temperature for 10 minutes. The resulting liquid was a clear and viscous solution.

[0048]

[Table 2]

Preparation of Hygroscopic Coating Liquid-3 According to the components (parts by weight) shown in Table 3, the hygroscopic coating liquid-3 is prepared. Polymer liquids 1 and 2 obtained in the above are stirred and mixed at room temperature. Next, a binder solution is prepared in the same manner as described above. The polymer solution and the binder solution were mixed in the same manner as described above, and stirred at room temperature for 10 minutes. The resulting liquid was a clear and viscous solution.

[0050]

[Table 3]

[0051]

Example 2 Film formation of antifogging mirror First, a hygroscopic film was formed on the mirror surface using hygroscopic coating liquid-1. Coating is performed by a curtain coat method. The mirror is placed horizontally on a guide table and the coating weight is 105 g / m ² , 260 g / m ² and 310 g / m ²
Adjust the feed rate of the table so as to obtain m ² . After coating, it is dried for 10 minutes in a thermostat set at 150 ° C. These samples were designated as samples a, b, and c, respectively. Subsequently, the operation of setting the coating amount to 270 g / m ² and leaving the coating at room temperature for 3 minutes after coating was repeated 29 times,
After the 30th application, the mixture is dried in a thermostat set at 150 ° C. for 10 minutes. Two sheets were prepared by this method and used as samples d and e, respectively. Next, a hygroscopic coating liquid-
2, the coating amount is set to 275 g / m ² , and the same procedure is carried out as in the case of the hygroscopic coating liquid-1. This sample was designated as sample f. Furthermore, the hygroscopic coating liquid-3 is
The coating amount was set to 345 g / m ^2, and the operation of leaving the coating at room temperature for 3 minutes after coating was repeated twice. After the third coat was further coated, the coating was performed in a thermostat set at 150 ° C. for 10 minutes. Dry for minutes. This sample was designated as sample g.

[0052]

Example 3 Measurement of Material Properties The thickness and the moisture absorption capacity of the hygroscopic film of the manufactured sample are measured. The thickness of the film was determined by a method of scanning a step of the film with an atomic force microscope. The instrument is a scanning probe microscope (D3000 manufactured by Digital Instruments)
It is. Further, the moisture absorption capacity X is obtained by calculating the saturated adsorbed water amount x per unit area when the water vapor is adsorbed at 30 ° C. until the water vapor is saturated, and further dividing the x by the film thickness T at the time of drying. did. Table 4 shows the measured values.

[0053]

Example 4 Prediction of Antifogging Property The produced sample was simulated as to whether or not the above equation (5) or (6) was satisfied, that is, whether or not the sample had a sufficient antifogging property. Table 4 shows the results.

[0054]

Example 5 Evaluation of Antifogging Property The prepared sample was set in a washroom or a bathroom, and the antifogging property (antifogging maintenance time) was evaluated under different environmental conditions. Table 4 shows the measured antifogging maintenance times.

[0055]

[Table 4]

As shown in Table 4, with respect to the antifogging retention time of each material, the calculated result and the measured value are in good agreement, and satisfy the relational expression relating to the material properties of the hygroscopic film shown in the present invention. If it is in the range, it has sufficient hygroscopicity.

[0057]

According to the present invention, the surface of the anti-fogging composite material of the present invention is less likely to adhere to fine water droplets. Do not let. Further, with respect to the hygroscopic coating on the surface of the anti-fogging composite material of the present invention, the optimum material composition can be determined depending on the use environment in order to secure necessary anti-fogging performance.

[Brief description of the drawings]

FIG. 1 shows an antifogging composite material having a hygroscopic coating composition layer formed on a substrate surface.

[Explanation of symbols]

 1: hygroscopic coating composition layer 2: base material 3: composite polymer in which organic molecules are crosslinked to an inorganic skeleton 4: water-absorbing organic polymer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/05 C08K 5/05 // C03C 17/30 C03C 17/30 A F term (Reference) 3B111 AA01 AA03 AC01 AC02 AC03 AD01 BB03 BC01 BC02 BC03 CA03 4G059 AA01 AA11 AC21 FA07 FA28 FB05 GA01 GA04 GA16

Claims (6)

[Claims] 1. The method according to claim 1, wherein the surface of the base material is coated with a hygroscopic coating composition, and the base material is coated with a transparent hygroscopic coating composition comprising a hybrid substance in which organic molecules are crosslinked to an inorganic skeleton. Antifogging composite material. 2. An inorganic alkoxide comprising a substrate surface coated with a hygroscopic coating composition, wherein the alkoxide has at least one kind of a polymer having an OH group formed by hydrolysis and polycondensation; An antifogging composite material characterized by being coated with a hygroscopic coating composition containing a water-absorbing organic polymer, a catalyst, and a water-containing organic solvent. 3. The method according to claim 1, wherein said antifogging composite material is 1/1 in an indoor environment of 0.003 <C ₀ <0.03.
_{2 <T × X / 116480C 0} 2 and 10 ^{- 6} <T <3 ×
10 ^{- 4} satisfying the above material characteristics T, antifogging composite material according to claim 1 or 2, characterized in that it has a X.
Here, C ₀ : water vapor concentration (kg _water / m ³ _air ), T: film thickness (m), X: moisture absorption capacity (kg _water / m ³ _film ) 4. The antifogging composite material according to claim 3, wherein the antifogging composite material is a toilet mirror. 5. The method according to claim 1, wherein the composite material is used in a room.
Under the environment of 6 <C ₀ <0.055, 0.5 <T ×
X / 116480C ₀ ² and ^{10 - 6 <T <3 ×} 10 - 4 satisfying the above material characteristics T, antifogging composite material according to claim 1 or 2, characterized in that it has a X. Where C
₀ : water vapor concentration (kg _water / m ³ _air ), T: film thickness (m),
X: moisture absorption capacity (kg _water / m ³ _membrane ) 6. The antifogging composite material according to claim 5, wherein the antifogging composite material is a bathroom mirror.