JPS59179627A - Antifogging of transparent material - Google Patents

Abstract

PURPOSE:To form an antifogging film excellent in a sustained antifogging effect and wet surface hardness, by coating the surface of a transparent material with an antifogging agent comprising a silyl group-containing modified PVA, and impregnating this surface with a hydrophilic compound. CONSTITUTION:The surface of a transparent material such as a plastic material or an inorganic glass (e.g., vehicle or aircraft window glass or spectacle lenses) is coated with an antifogging agent comprising either a silyl group-containing modified PVA (e.g., a modified PVA obtained by saponifying a vinyltrimethoxysilane/vinyl acetate copolymer, having a silyl group content (in the form of a vinylsilane unit) of 1.0mol%, a degree of saponification of vinyl acetate unit, of 98.8mol%, and a degree of polymerization of 600) or both the copolymer and an inorganic substance (e.g., colloidal silica), and the coated film is impregnated with a hydrophilic compound (e.g., nonionic or anionic surfactant). An antifogging film excellent in a sustained antifogging effect and wet surface hardness can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-fogging method for transparent materials, and more particularly to an anti-fogging method that provides long-lasting anti-fogging properties and excellent surface hardness upon water absorption.

In general, transparent materials such as plastic materials and inorganic glasses are widely used as architectural, vehicle, or aircraft window glasses, mirrors, eyeglass lenses, goggles, agricultural films, and food packaging films. However, these transparent materials have the disadvantage that moisture in the atmosphere condenses on the surface under conditions of high humidity or when the surface temperature is below the dew point, causing the surface to become cloudy. In addition, plastic materials have the disadvantage that their surfaces are easily scratched, and transparency tends to decrease due to scratches.

Various attempts have been made to prevent such phenomena and to provide anti-fogging and scratch-resistant properties to the surface of transparent materials. For example, methods have been proposed in which surfactants, chrycerin, polyalkylene glycols, cellulose derivatives, polyvinyl alcohol, polyhydroxyalkyl acrylates, polyethyleneimine, etc. are applied to improve the water wettability of the surface of transparent materials. However, although this method can temporarily impart antifogging properties, it has drawbacks such as the antifogging effect decreases over time due to the outflow of the antifogging agent, and scratch resistance is insufficient. was. Mani% 1986-39347, 1984-9998
7 or Japanese Patent Application Laid-Open No. 57-73059 etc. Antifogging whose main components are a hydrophilic polymer such as polyvinyl alcohol (hereinafter polyvinyl alcohol is abbreviated as PVA) and silica, or a combination of these and a low-molecular organosilicon compound. A method of forming a sexual film is disclosed. However, the antifogging coatings produced by these methods have the disadvantage that their surface hardness is low when water is absorbed, and they are easily scratched by nails, etc., and they also have insufficient water wettability and cannot be exposed to high humidity conditions for long periods of time. It had the disadvantage that it easily fogged up when left on the shelf, so it was not practical at all.

The present inventors have conducted intensive studies on an anti-fogging method that overcomes the above-mentioned drawbacks and provides good water wettability, sustained anti-fogging properties, and sufficient surface hardness and scratch resistance upon water absorption. After coating the surface of a transparent material with modified PVA having a silyl group or an antifogging treatment agent made of PVA and an inorganic substance, the antifogging properties must be maintained when the coating film is impregnated with a hydrophilic compound. The inventors have now completed the present invention by discovering that the surface hardness upon absorption of water can be significantly higher than that of conventional antifogging agents, and the scratch resistance can also be increased.

The present invention will be explained in more detail below. The modified PVA having a silyl group in the molecule used in the present invention may be any type as long as it has a silyl group in the molecule. Particularly preferably used are those in which the group has a reactive substituent such as an alkoxyl group, an acyloxyl group, a silanol group which is a hydrolyzate thereof, or a salt thereof. ○ As a method for producing such modified PVA, A method of introducing a silyl group into modified polyvinyl acetate containing a carboxyl group or a hydroxyl group by post-modification using a silylating agent. (2) A method of saponifying a vinyl ester polymer having a silyl group at the terminal obtained by polymerizing a vinyl ester in the presence of a mercaptan having a silyl group. In the method, for example, the silylating agent is dissolved in an organic solvent that does not react with the silylating agent, such as benzene, toluene, xylene, hexane, heptane, ether, or acetone, and powdered PV is dissolved in the solution.
A or the above-mentioned modified polyvinyl acetate is suspended or dissolved with stirring, and the silylating agent and PVA are mixed at a temperature ranging from room temperature to the boiling point of the silylating agent. Alternatively, a silyl group-containing modified PVA can be obtained by reacting the above modified polyvinyl acetate or by further saponifying the vinyl acetate unit of the modified polyvinyl acetate using an alkali catalyst or the like. The silylating agents used in post-modification include trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, diphenyldichlorosilane, triethylfluorosilane, organohalosilane, ge/silane, trimethylacetoxysilane, dimethyl Organosilicon esters such as diacetoxysilane, trimethylmethoxysilane,
Examples include organoalkoxysilanes such as dimethyldimethoxysilane, organosilanols such as trimethylranol and diethylsilanediol, aminoalkylsilanes such as N-aminoethylaminepropyltrimethoxysilane, and organosilicon incyanates such as trimethylsilicone incyanate. . The rate of introduction of the silylating agent, that is, the degree of modification, can be arbitrarily adjusted by adjusting the amount of the silylating agent used and the reaction time. The polymerization degree and saponification degree of the obtained silyl group-containing modified PVA are determined by the P used.
A copolymer of a vinyl ester and an olefinically unsaturated monomer containing a silyl group, which can be arbitrarily adjusted by the polymerization degree and saponification degree of VA or the polymerization degree and saponification reaction of the above-mentioned modified polyvinyl acetate. In the method of saponifying a vinyl ester, for example, a vinyl ester and a silyl group-containing olefinic unsaturated monomer are copolymerized using a radical initiator, and then an alcoholic solution of the copolymer is added to an alkaline or acidic catalyst. By adding and saponifying the copolymer, a silyl group-containing modified PVA can be obtained. Vinyl esters used in the above method include vinyl acetate, vinyl propionate, vinyl formate, etc. However, from an economical point of view, vinegar is the best! 9 vinyl is a great choice. Examples of the silyl group-containing olefinically unsaturated monomer used in the above method include nylsilane represented by the following formula (1), and (meth)acrylamide-alkyl 7rane represented by (■).

[Here, n is O~4, m is O~2, R1 is carbon number 1~5
alkyl group (methyl, ethyl, etc.), B2 has 1 carbon number
~40 alkoxyl group or acyloxyl group (herein, the alkoxyl group or acyloxyl group may have an oxygen-containing substituent), R3 is a hydrogen atom or a methyl group, R4 is a hydrogen atom or a carbon number of 1 to 5 The alkyl group 15 represents an alkylene group having 1 to 5 carbon atoms or a divalent organic residue in which chain carbon atoms are mutually bonded through oxygen or nitrogen. In addition, when two R1s exist in the same monomer, R1 may be the same,
They may be different. Furthermore, when two or more R2s exist in the same monomer, R2s may be the same or different.

Specific examples of vinyltris represented by formula (1) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-(β-methoxyethoxy)7rane, vinyltriacetkinsilane, allyltrimethoxysilane, allyltriacetoxy Vinlan, vinylmethyldimethoxy7lan, vinyldimethylmethoxysilane, vinylmethyljethoxysilane, vinyldimethylethoxysilane, vinylmethyldiacetoxysilane, vinyldimethylacetoxysilane, vinylisobutyldimethoxysilane, vinyltriinpropoquinesilane, vinyltributoxysilane , Vinyltrihexyloxysilane, Vinylmethoxydihexyloxysilane, Vinyldimethoxyoctyloxysilane, Vinylditoxyoctyloxysilane, Vinyltrioctyloxysilane, Vinylmethoxydioleyloxysilane, Vinyldimethoxyoctyloxysilane, Vinylmethoxydio Reiloxysilane, vinyldimethoxyoctyloxysilane, and general formula %) (where R'' and m are the same as above, and X represents 1 to 20)
Examples include polyethylene glycolized vinyl 7ran represented by: Specific examples of the (meth)acrylamide-alkylsilane represented by formula (It) include 3-(meth)acrylamide-propyltrimethoxysilane, 3-(meth)acrylamide-propyltriethoxysilane, and 3-(meth)acrylamide-propyltriethoxysilane. ) acrylamide-propyltri(β-methoxyethoxy)silane, 2-(meth)acrylamido-2-methylethyltrimethoxy7rane,
2 (meth)acrylamide-2-methylethyltrimethoxy7rane, N-(2-(meth)acrylamide-
ethyl)-aminopropyltrimethoxysilane, 3-(
meth)acrylamide-propyltriacetoxysilane, 2 (meth)acrylamide-ethyltrimethoxy 7
Ran, 1-(meth)acrylamide-methyltrimethoxysilane, 3-(meth)acrylamide-propylmethyldimethoxysilane, 3(meth)acrylamide-
Propyldimethylmethoxysilane, 3-(N-methyl-
(meth)acrylamide)-propyltrimethoxysilane, 3-((meth)acrylamide-methoxy)-3-
Hydroxyglobyl trimethoxysilane, 3-((meth)acrylamido-methoxy)-propyltrimethoxysilane, dimethyl-3-(meth)acrylamido-propyl-3-()rimethoxysilyl)-propylammonium chloride, dimethyl-2 -(meth)acrylamido-2-methylpropyl-3-(trimethoxysilyl)-propylammonium chloride and the like.

In addition, in producing modified PVA by this method, when copolymerizing the vinyl ester and the silyl group-containing olefinic unsaturated monomer, other unsaturated monomers that can be copolymerized with the monomer other than the above two components are used. Monomers such as styrene, alkyl vinyl ethers, vinyl versatate,
(meth)acrylamide, ethylene, propylene, α-
Olefins such as hexene and α-octene, (meth)acrylic acid, crotonic acid, (anhydrous) maleic acid, fumaric acid,
Unsaturated acids such as itaconic acid, and alkyl esters thereof,
Alkali salts, 2-acrylamido-sulfonic acid-containing monomers such as 2-methylpropanesulfonic acid and their alkali salts, trimethyl-2-(1-(meth)acrylamide-
cationic monomers such as 1,1-dimethylglobyl)ammonium chloride, trimethyl-3-(1-(meth)acrylamidopropyl)ammonium chloride, 1-vinyl-2-methylimidazole and its quaternized products. It is also possible to have them present in proportions.

In addition, in a method of saponifying a vinyl ester polymer having a silyl group at the terminal obtained by polymerizing a vinyl ester in the presence of a mercaptan having a heptadyl group, for example, vinyl ester is converted into a vinyl ester using a radical initiator. During polymerization, a mercaptan having a silyl group is added to the polymerization system all at once, in portions, or continuously, so that the mercaptan having a silyl group is present in the polymerization system, and by chain transfer to the mercaptan, vinyl having a silyl group at the end is produced. Modified PVA having a silyl group can be obtained by producing an ester polymer and saponifying the polymer by adding an alkali or acid catalyst to an alcoholic solution of the polymer.

Examples of the mercaptan having a silyl group used in this method include 3-(trimethinesilyl)-propylmercaptan and 3-()lietoxinlyl)propylmercaptan.

In producing modified PVA using this method, ■(7)
It is also possible to have small proportions of unsaturated monomers copolymerizable with the vinyl ester used in the process.

In the above-mentioned three production methods of modified PVA having a silyl group in the molecule used in the present invention, a copolymer of a vinyl ester and an olefinic unsaturated monomer having a silyl group is saponified. The method of saponifying a vinyl ester polymer having a silyl group at the terminal obtained by polymerizing a vinyl ester in the presence of a mercaptan having a silyl group has advantages in ease of industrial production and homogeneity of the resulting modified PVA. It is preferably used in this respect.

Modified PVA with silyl group used in the present invention
The content of silyl groups, the degree of saponification, and the degree of polymerization are appropriately selected depending on the purpose and are not particularly limited. The silyl group exhibits its effect even in a relatively small content, and is usually selected from the range of 0.01 to 10 moles, preferably 0.1 to 2.5 moles, as a monomer unit to which a 7lyl group is bonded. It will be done. The saponification degree is usually preferably in the range of 70 to 100 molar. Further, the degree of polymerization is usually selected from the range of 10 to 3,000.

When dissolving the above-mentioned modified PVA used in the present invention in water, the modified PVA is usually dispersed in water by adding an alkaline solution such as sodium hydroxide, potassium hydroxide, or ammonia as the case may be, and then adding the solution while stirring. A homogeneous aqueous solution can be obtained by heating.

The inorganic substances that may be used in the present invention preferably contain elements such as aluminum, silicon, magnesium, and calcium, and specifically include clay, talc,
Examples include calcium carbonate, calcium silicate, silica, aluminum oxide, etc., and inorganic aqueous solutions such as water glass, water-soluble aluminum compounds (e.g., sodium aluminate, pan earth), and water-soluble zirconium compounds (e.g., zirconium ammonium carbonate) are also used. I can do it. However, when an inorganic aqueous solution is used at a high concentration, when mixed with PVA having a silyl group in the molecule, the viscosity stability of the mixed aqueous solution is low and there is a risk of gel formation in some cases, so it is not the best. For the purpose of the present invention, inorganic fine particles are preferred, and inorganic fine particles with an average particle diameter of 200 mμ or less, particularly colloidal silica or colloidal alumina, are particularly preferred. Best in terms of transparency and surface hardness upon water absorption.

If the particle size exceeds 200 mμ, the resulting coating film tends to have poor transparency, which is not preferred.

In the antifogging treatment agent used in the present invention, there is no particular restriction on the blending ratio of modified PVA having a silyl group in the molecule and inorganic particles, particularly inorganic fine particles with an average particle size of 200 mμ or less, and any ratio can be used. , ←S←←The blending ratio of modified PVA having a 7-lyl group in the molecule and inorganic material, particularly inorganic fine particles having an average particle diameter of 200 mμ or less, is preferably 0.5/99.5 to 9515 for the former/latter. is 1/99 to 90/10. When the latter blending ratio is less than 5, the surface hardness upon water absorption is low, 99.5
If it exceeds 20%, the adhesion of the resulting coating film to the transparent material and the scratch resistance during drying will decrease.

As mentioned above, the antifogging treatment agent used in the present invention must be composed of modified PVA having a silyl group in the molecule, or an inorganic substance, and fine inorganic particles having a K average particle size of 200 mμ or less. However, it is possible to contain other solvents, various additives, etc. depending on the purpose.

Water is preferably used as the solvent, but various alcohols, ketones, dimethylformamide, dimethyl sulfoxide, and other solvents can also be used in combination with water.

Additives include various antifoaming agents, nonionic or anionic surfactants, carboxymethyl cellulose,
Cellulose derivatives such as hydroquine ethylcellulose, poly(meth)acrylic acid, polyhydroxy(meth)acrylate or copolymers thereof, polyacrylamide, etc.
meth)acrylic polymer, polyvinylpyrrolidone or its copolymer, carboxy group-containing modified PVA, sulfuric acid group-containing modified PVA, sulfonic acid group-containing modified PVA, I
Modified PVA containing J-acid group Modified PVA containing quaternary ammonium base, modified PVA containing amine group, PVA derivatives such as general PVA, acrylic polymers and copolymers, ethylene-vinyl acetate copolymers, vinyl ester polymers and Aqueous dispersions such as copolymers and styrene-butadiene copolymers can be added, and furthermore, silane coupling agents and the like can be added as appropriate.

The antifogging treatment agent used in the present invention can be dissolved or dispersed in water or water containing the above-mentioned organic solvent and applied to various transparent materials as an aqueous solution or aqueous dispersion. It is used by coating a transparent material with an aqueous dispersion. Transparent materials to which the anti-fogging method of the present invention can be applied are not particularly limited, but examples include inorganic glass, plastics, metals, etc. Specific examples include window glass for automobiles, trains, pills, etc., and eyeglass lenses. It is preferably used for mirrors in bathrooms, plastic films for agriculture, plastic films for window glass, etc.

Methods for applying the antifogging treatment agent used in the present invention to transparent materials include, for example, no-ke coating, dip coating,
Various methods commonly known in the art can be used, such as spin coating, flow coating, spray coating, roll coating, air knife coating, blade coating, etc.

The antifogging treatment agent used in the present invention is applied to a transparent material by the method described above;
By appropriately performing heat treatment, a coating film with a high surface hardness upon water absorption can be obtained.

The coating film formed with the antifogging treatment agent used in the present invention is impregnated with a hydrophilic compound, thereby further improving the water wettability of the coating surface.

As the hydrophilic compound, one or more hydrophilic compounds selected from the group consisting of low-molecular surfactants, polyhydric alcohols, and water-soluble polymers are preferably used. Specifically, low-molecular surfactants such as nonionic, anionic, and cationic, polyhydric alcohols such as ethylene glycol, chrycerin, 3-methylpentanetriol, pentaerythritol, and sugar alcohols, polyethylene glycol, (meth) Acrylic acid polymers and copolymers, (
meth)acrylamide polymers, water-soluble synthetic trees such as modified PVA having ionic hydrophilic groups such as carboxyl groups, sulfonic acid groups, phosphoric acid groups or quaternary ammonium bases;
Water-soluble cellulose derivatives such as carboxymethyl cellulose and hydroquine ethyl cellulose can be used, but nonionic or anionic low molecules are preferred in terms of water wettability and sustained antifogging properties of the coating film formed by the antifogging treatment agent. Modified PVA having a surfactant or an ionic hydrophilic group is preferably used.

The method for impregnating the above-mentioned coating film with the hydrophilic compound is not particularly limited, and methods such as dipping in an aqueous solution of an aqueous compound, spraying an aqueous solution of a hydrophilic compound, or applying a known method are employed. Ru. There is no particular restriction on the amount of the hydrophilic compound impregnated, and it is sufficient as long as it is at least the amount that forms a monomolecular film on the coating film.
200 copies or less.

In addition, in order to improve the adhesion between the transparent material and the antifogging agent used in the present invention, the surface of the transparent material may be coated with various primers or adhesives in advance, as the case may be.
Pretreatment such as activated gas treatment or chemical treatment with acid or base is also effective.

The method of the present invention is characterized by providing lasting antifogging properties, sufficient surface hardness and scratch resistance upon water absorption, and excellent water wettability. Although the reason why the method of the present invention can provide the above-mentioned remarkable performance is not fully elucidated, the hydroxyl group in the modified PVA having a silyl group in the molecule used in the method of the present invention and the above-mentioned hydrophilic Anti-fogging properties are exhibited due to the hydrophilicity of the compound, and the silyl group to which an alkoxyl group or acyloxyl group is bonded, or the silanol group which is a hydrolyzate of these, or a salt thereof is a hydroxyl or silanol group in an inorganic substance or modified PVA. Because of its high reactivity with salts, it is presumed that they react with each other to form a strong film, which exhibits high surface hardness and scratch resistance even when water is absorbed. In particular, when the transparent material to which the method of the present invention is applied is inorganic glass, the adhesion of the coating film to the glass becomes extremely high due to the strong interaction between the silyl groups in the modified PVA and the glass. i)% effective.

The non-invention will be explained in more detail with reference to examples below.
The present invention is not limited thereby. In the examples, unless otherwise specified, "chi" and "part" represent weight standards.

Example 1 A copolymer of vinyltrimethynesilane and vinyl acetate was saponified to produce a molecule containing 1.0 mol of silyl groups as vinyl silane units, a degree of saponification of vinyl acetate units of 98.8 mol, and a degree of polymerization of 600. 49 modified polyvinyl alcohol having a silyl group inside. This modified PVA is converted into modified PV
A 10% aqueous solution was prepared by dissolving A in an aqueous solution containing 2.5% sodium hydroxide, and the solution was coated on a glass plate to a thickness of 5 μm after drying. The obtained coating film is 1/
A test piece was prepared by immersing it in a 2N sulfuric acid bath, washing it, heat-treating it at 150°C for 1 minute, spraying a 2% aqueous solution of sodium dodecylbenzenesulfonate as a hydrophilic compound, and drying it. Using this test piece, antifogging properties, adhesion to glass, and surface hardness were measured. The results are shown in Table 1. It can be seen from Table 1 that the antifogging agent of the present invention is significantly superior in water wettability, sustained antifogging properties, adhesiveness, and surface hardness upon water absorption.

Comparative Example 1 Instead of the modified PVA of Example 1, a commercially available low-molecular-weight surfactant-based antifogging agent was applied to a glass plate by a spray method.
Antifogging properties were measured in the same manner as above.

The results are shown in Table 1.

Comparative Example 2 In place of the modified PVA of Example 1, general partially saponified PVA
To 100 parts of a 20% aqueous solution of V A (M 600, degree of saponification 88), 100 parts of colloidal silica (Nissho Kagaku Kogyo ■, Snowtex-01 solid content 20%) and vinyltris (β-methoxyshetoxy 7) parts were added. A composition prepared by mixing and heating at a temperature of 80°C for 1 hour was applied in the same manner as in Example 1, and the resulting coating film was heat-treated at 150°C for 3 minutes. , the surface hardness was measured.

The results are shown in Table 1.

Comparative Example 3 In place of the modified PVA of Example 1, Example 1 was prepared using a methanol solution of 2-hydroxyethyl methacrylate copolymerized with 5 mol of glycidyl methacrylate.
The coating film obtained was coated on a glass plate in the same manner as 120
After heat treatment for 30 minutes with ``:'', antifogging properties, adhesion properties, and surface hardness were measured in the same manner as in Example 1.The results are shown in Table 1.

Table 1 1) Anti-fogging property = Place the test piece on a container that generates 40°C saturated steam in a 20°C room for 1 minute, apply saturated steam, then dry the test piece and place it on the container again. This was repeated 10 times, and the number of repetitions was expressed as the number of repetitions until fogging occurred in one minute.

2) Adhesion: Make 11 perpendicular cuts in the length and width on the surface of the test piece at 1-cut intervals with a knife until they reach the glass, and after making 100 squares with a side length of 1-cut in a grid pattern, Cellophane adhesive tape was applied at 20° C. (normal) or at 20° C., and the number of squares that remained without peeling was expressed when it was instantly peeled off.

3) Surface hardness: The surface of the test piece was immersed in water at 20° C. for 12 hours as it was (normal state), and then scratched with pencil leads of various hardnesses, and the hardness was expressed as the highest pencil hardness without scratches.

Examples 2 to 5 The same procedure as in Example 1 was carried out except that the following hydrophilic compounds were used in place of the hydrophilic compounds used in Example 1. The results are shown in Table 2.

Example 2: 2% aqueous solution of nonylphenyl ether of polyethylene glycol.

Example 3: 2% aqueous solution of glycerin.

Example 4: Contains 2 molar carboxyl group units, saponification degree of vinyl acetate unit 98.5 molar ratio, polymerization degree 1750
(7) Modified PVA (1% ID aqueous solution).

Example 5: An aqueous solution of modified PVA containing 1 mole of sulfonic acid group units, a degree of saponification of vinyl acetate units of 98.5 moles, and a degree of polymerization of 1750.

Table 2 with blank space below Example 6 Contains 0.5 mole of silyl group obtained by saponifying a copolymer of vinyltrimethoxysilane and vinyl acetate as a vinyl silane unit, saponification degree of vinyl acetate unit is 99,
A 10% aqueous solution of modified PVA was prepared by dissolving modified PVA with a polymerization degree of 0 and a degree of polymerization of 700 in water containing 1.5 parts of sodium hydroxide based on the amount of modified PVA. Add 100 parts of this aqueous solution to colloid/l/silica (Nippon Kagaku Kogyo ■,
An aqueous dispersion of the antifogging composition of the present invention was obtained by adding 50 parts of Snowtex = 20, particle size 10 to 20 mμ, solid content 20 cm). This aqueous dispersion was coated on a glass plate using a bar coater to a thickness of 5 μm after drying, and heated at 105°C for 1 hour.
After drying for 0 minutes, it was immersed in a 1/2N sulfuric acid bath, further washed with water, and heat-treated at 150° C. for 1 minute. A 100% aqueous solution of polyacrylic acid was spray-coated on the resulting coating film on the glass plate, and then dried to obtain a test piece. Using the obtained test piece, heat resistance, adhesion to glass, and surface hardness were measured in the same manner as in Example 1. The results are shown in Table 3. Table 3 shows that the antifogging composition of the present invention is significantly superior in sustained antifogging properties, adhesion, and surface hardness upon water absorption.

Examples 7 to 13 The same procedure as in Example 1 was carried out except that the following modified PVA aqueous solution was used in place of the modified PVA aqueous solution used in Example 6.

The results are shown in Table 3.

Modified PVA aqueous solution used in Example 7: Contains 0.5 mol of silyl groups obtained by saponifying a copolymer of vinyltriethoxysilane and vinyl acetate as vinyl silane units, and has a saponification degree of vinyl acetate units of 98. A 10% aqueous solution obtained by dissolving modified PVA with a molar ratio of 0.5 molar mass and a degree of polymerization of 700 in an aqueous solution containing 1.5% potassium hydroxide based on the modified PVA.

Modified PVA aqueous solution used in Example 8: Contains 0.15 moles of silyl groups obtained by saponifying a copolymer of 3-methacrylamidoglopyltrimethoxine oran and vinyl acetate in methacrylamiton oran units. A 10% aqueous solution obtained by dissolving modified PVA with a degree of saponification of vinyl acetate units of 88 molar and a degree of polymerization of 2000 in water.

The modified PVA aqueous solution used in Example 9 contained 0.20 mol of silyl groups obtained by saponifying the copolymer with vinyl triacetoxysilane as vinyl silane, and the degree of saponification of vinyl acetate units was 98. 10 obtained by dissolving modified PVA with a polymerization degree of 1750 in water with a molecular weight of .5
Steamed rice aqueous solution.

Modified PVA aqueous solution used in Example 10: 0.25 silyl groups obtained by saponifying a copolymer of vinyltriynepropoxysilane and vinyl acetate as vinylsilane units
Contains momol, degree of oxidation of vinegar 172 vinyl units 89.0
A 10% aqueous solution obtained by dissolving modified PVA with a molar ratio and degree of polymerization of 175o in water.

Modified PVA used in Example 11
3-methacrylamidoglopyruti-+ 3-)rimethoxysilylglobin Contains 0.2 mol of silyl group obtained by saponifying a copolymer of needle ammonium chloride and vinyl acetate, and contains vinyl acetate units. Saponification degree 98.
A 1° aqueous solution obtained by dissolving modified PVA with a 5 molar ratio and a polymerization degree of 1750 in water.

Modified PVA aqueous solution used in Example 12: When vinyl acetate is radically polymerized in methanol, 3-()rimethoxysilyl)-globilmercabutane is continuously added to the polymerization system. Modified polyvinyl acetate containing a silyl group is saponified to have a silyl group containing 1 mole of propyl mercaptan units, a degree of saponification of the vinyl acetate unit of 99.0 moles, and a degree of polymerization of 100 1)
2 obtained by obtaining VA and dissolving this modified PVA in water.
0% aqueous solution.

Modified PV''A aqueous solution used in Example 13: Contains 4 molar groups of silyl groups obtained in the same manner as in Example 12 as propyl mercaptan units, has a vinyl acetate unit conversion degree of 986 molar units, and a polymerization degree of 25. 20% aqueous solution of modified PVA.

Table 3 Examples 14 to 17 The same procedure as in Example 6 was carried out except that the following amounts were used instead of 50 parts of colloidal silica in Example 6. The results are shown in Table 4.

Example 14 - 10 parts of Snowtex-N (Hinami Chemical Industry ■, particle size 10-20 mμ, solid content 20%) Example 15. Snowtex-N 25 W + Example 16: 50 parts of Snowtex-30 (Hinami Chemical Industry ■, particle size 10-20 mμ, solid content 30q6) Example 17: 150 parts of Snowtex-30 Example 1
8 Instead of the glass plate used in Example 6, a commercially available urethane adhesive (Toyo Morton Co., Ltd., Atkote 1030.10
The same procedure as in Example 6 was performed except that a polyester film coated with a mixed solution of 0 parts of curing catalyst CAT- and 17 parts of curing catalyst CAT- to a thickness of 4 μm was used. The results are shown in Table 4.

Claims (1)

[Scope of Claims] (1) After coating the surface of a transparent material with an antifogging treatment agent made of modified polyvinyl alcohol having a silyl group in the molecule or an inorganic substance, a hydrophilic compound is applied to the coating film. A method for antifogging a transparent material, the method comprising impregnating it with a transparent material. (2) Claims characterized in that the modified polyvinyl alcohol having a silyl group in the molecule is a saponified product of a copolymer of a vinyl ester and an olefinically unsaturated monomer having a silyl group in the molecule. 2. The antifogging method for a transparent material according to item 1. (The olefinically unsaturated monomer having a silyl group in the molecule has the following general formula (1) [where n is 0 to 4, m is 0 to 2, and R1 has a carbon number of 1 to 5].
The alkyl group R2 is an alkoxyl group or an acyloxyl group having 1 to 40 carbon atoms (here, the acyloxyl group and the acyloxyl group may have an oxygen-containing sulfur substituent)
shows. ] The antifogging method for a transparent material according to claim 2, which is a vinyl silane represented by the following. (4) The olefinically unsaturated monomer having a silyl group in the molecule has the following general formula (n) [where m is O~2, R1 is an alkyl group having 1 to 5 carbon atoms, and R2 is an alkyl group having 1 to 40 carbon atoms] The alkoxyl group is an acyloxyl group (the alkoxyl group or acyloxyl group may have an oxygen-containing substituent), R3 is a hydrogen atom or a methyl group, and R4 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R5 represents an alkylene group having 1 to 5 carbon atoms or a divalent organic residue in which chain carbon atoms are bonded to each other via oxygen or nitrogen. ] The method for antifogging a transparent material according to claim 2, which is a monomer represented by the following. (Li) The modified polyvinyl alcohol having a silyl group in the molecule is a saponified product of a polyvinyl ester having a silyl group at the end obtained by polymerizing a vinyl ester in the presence of a mercaptan having a silyl group. The antifogging method for a transparent material according to claim 1. (6) The transparency according to claim 1, wherein the modified polyvinyl alcohol contains 0.01 to 10 mol of a monomer unit having a silyl group in the molecule. A method for antifogging a material. (7) A method for antifogging a transparent material according to claim 1, wherein the inorganic substance is fine particles with an average particle size of 200 mμ or less. An anti-fogging method for a transparent material according to claim 1. (ii) An anti-fogging method for a transparent material according to claim 1, wherein the inorganic substance is colloidal silica. (WO) Silyl in the molecule. The weight blending ratio of modified polyvinyl alcohol having a group/inorganic substance is 1/99 to 90/
10. The method for antifogging a transparent material according to claim 1. 01) The method for antifogging a transparent material according to claim 1, wherein the R aqueous compound is a nonionic or anionic surfactant. (12) The antifogging method for a transparent material according to claim 1, wherein the hydrophilic compound is a modified polyvinyl alcohol having an ionic hydrophilic group. (13) The antifogging method for a transparent material according to claim 1, wherein the transparent material is an inorganic glass. 04) The method for anti-fogging a transparent material according to claim 1, wherein the surface of the transparent material to be coated with an anti-fog treatment agent has been subjected to adhesive coating treatment in advance.