JPH09194828A - Antifogging agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antifogging agent composition which can form antifogging films having good antifogging properties, good persistency of these properties, and especially excellent hardness and scratch resistance. SOLUTION: This composition contains a block or graft copolymer and a dispersion of a metal oxide, especially a silicon oxide sol, surface-modified with a silane coupling agent. The block or graft copolymer is composed of segments of a hydrophilic polymer comprising a vinyl monomer having at least one kind of crosslinking groups selected from the group consisting of N-methylol groups, N-methylol ether groups and hydroxyl groups and a hydrophilic vinyl monomer and segments of a hydrophobic polymer comprising a sulfo, carboxylic or phosphoric vinyl monomer and a lower alkyl (meth)acrylate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antifogging composition for applying various transparent resin materials, for example, and more specifically to eyeglasses, sunglasses, goggles, lenses, face bodies, helmet shields and the like. The present invention relates to an antifog composition that exhibits excellent antifog properties and durability.

[0002]

2. Description of the Related Art Antifogging agent compositions of this type include, for example, N
-A block or graft copolymer formed from a hydrophilic polymer moiety and a hydrophobic polymer moiety containing a cross-linking functional group such as a methylol group, an N-methyl ether group, or a hydroxyl group. An antifogging composition containing a surfactant and a surfactant is known (JP-A-6-212146).

[0003]

However, in the above conventional antifogging agent composition, although excellent antifogging property and its durability can be imparted to the transparent resin material, the hardness of the formed antifogging coating film. However, there is a problem that the coating film is easily scratched and the generated scratches impair the transparency and appearance of the transparent resin material. Therefore, the use of this conventional antifogging composition has been limited to only the inner surface of the instrument cover and the instrument viewing window, various lamps, lenses, etc., which are less likely to be directly touched by human hands. .

The present invention has been made by paying attention to the problems of the prior art as described above. An object of the invention is to provide an antifogging agent composition capable of forming an antifogging coating film excellent in hardness and scratch resistance while maintaining good antifogging property and its durability.

[0005]

In order to achieve the above object, the antifogging agent composition of the first invention is surface-modified with a block copolymer or graft copolymer and a silane coupling agent. At least one selected from the group consisting of N-methyl group, N-methyl ether group and hydroxyl group, wherein the block copolymer or graft copolymer contains a dispersion of a metal oxide. A vinyl monomer having a cross-linking functional group, a hydrophilic polymer portion formed from a hydrophilic vinyl monomer, a vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group, and a lower alkyl (Meth) acrylate (in this specification, acryl and methacryl are collectively referred to as (meth) acryl) and is composed of a hydrophobic polymer portion.

In the second invention, in the first invention, the monomer forming the hydrophilic polymer portion of the block copolymer or the graft copolymer is further a lower alkyl (meth).
It contains an acrylate.

According to a third invention, in the first or second invention, a surfactant is further blended with the antifogging agent composition of the first or second invention, and the blending ratio of the surfactant is the above block. It is 0.1 to 30% by weight based on the total solid content of the dispersion of the copolymer or the graft copolymer and the metal oxide surface-modified with the silane coupling agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be sequentially described in detail below. The antifogging agent composition contains a specific block copolymer or graft copolymer and a dispersion of a metal oxide surface-modified with a silane coupling agent. As the metal oxide, a dispersion of silicon oxide, aluminum oxide, zirconium oxide, antimony oxide or the like is used, but a dispersion of silicon oxide is preferable from the viewpoint of reactivity with the silane coupling agent. Also, as the dispersion,
The sol is preferable from the viewpoint of reactivity with the silane coupling agent. Further, the antifogging agent composition optionally contains a surfactant and a solvent.

The block or graft copolymer comprises a hydrophilic polymer portion and a hydrophobic polymer portion. The hydrophilic polymer portion includes an N-methyl group, an N-methyl group and an N-methyl group.
It is formed from a hydrophilic vinyl monomer and a vinyl monomer having at least one cross-linking functional group selected from the group consisting of a ter group and a hydroxyl group.

Examples of the vinyl monomer having an N-methylol group and an N-methylol ether group include, for example, N-methylol (meth) acrylamide, N-methoxymethylol (meth) acrylamide, N- Examples thereof include butoxymethylol (meth) acrylamide, and N-methylol (meth) acrylamide is particularly preferably used because of its high crosslinking reactivity. Examples of the vinyl monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.
Praxel FA-1, Praxel FM-1, Praxel FM-4 in which 1 to 4 mol of ε-caprolactone was added to 1 mol of 2-hydroxyethyl (meth) acrylate.
[The above are trade names manufactured by Daicel Chemical Industries, Ltd.] and the like, and 2-hydroxyethyl (meth) acrylate is particularly preferably used because of its high crosslinking reactivity.

Examples of the hydrophilic vinyl monomer include (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide,
N-ethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N'-dimethylaminopropyl (meth) acrylamide, N , N′-dimethylaminoethyl (meth) acrylamide, diacetone (meth) acrylamide, N
-(Meth) acryloylpiperidine, N- (meth) acryloylmorpholine, methoxyethylene glycol (meth) acrylate (where the number of ethylene oxide is 1 to
An integer of 10 is preferable), methoxypropylene glycol (meth) acrylate (wherein the number of propylene oxide is preferably an integer of 1 to 10), (meth) acrylic acid, crotonic acid, itaconic acid, Maleic acid and the like can be mentioned, and at least one of them is used. Of these, N, N-dimethylacrylamide is particularly preferably used from the viewpoints of copolymerization reactivity and solubility of the resulting copolymer.

In this case, the constitutional proportion of the hydrophilic polymer portion usually has at least one crosslinking functional group selected from the group consisting of N-methyl group, N-methyl ether group and hydroxyl group. The vinyl monomer content is 1 to 30% by weight and the hydrophilic vinyl monomer content is 70 to 99% by weight. In particular, when the vinyl monomer having a crosslinking functional group is less than 1% by weight or the hydrophilic vinyl monomer exceeds 99% by weight, the crosslink density of the coating film is low and the water permeability to the coating film is low. It becomes too high and the coating strength decreases. On the other hand, when the vinyl monomer having the crosslinkable functional group exceeds 30% by weight or the hydrophilic vinyl monomer is less than 70% by weight, the crosslink density becomes too high and the antifogging property deteriorates. Adhesion to the resin material is reduced. Furthermore, anti-fog property, adhesiveness,
From the balance of coating strength and the like, the vinyl monomer having a crosslinking functional group is 5 to 20% by weight, and the hydrophilic vinyl monomer is 8% by weight.
A range of 0 to 95% by weight is particularly preferred.

In addition to the vinyl monomer having a cross-linking functional group in the hydrophilic polymer portion and the hydrophilic vinyl monomer, a lower alkyl (meth) acrylate is further copolymerized to obtain a high temperature environment. It is possible to improve coating strength, adhesion and heat resistance. Its lower alkyl (meth)
The acrylate means an alkyl (meth) acrylate having a linear or branched alkyl group having 1 to 4 carbon atoms. Examples of the lower alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate,
Examples thereof include iso-butyl (meth) acrylate and tert-butyl (meth) acrylate, and at least one of these is used. In particular, methyl methacrylate can increase the glass transition temperature of the most hydrophilic polymer part,
Preferably used.

In this case, the proportion of the hydrophilic polymer portion is usually 1 to 1 for the vinyl monomer having a crosslinkable functional group selected from N-methyl group, N-methylether group and hydroxyl group. 30% by weight, 2 hydrophilic vinyl monomers
0 to 84% by weight and lower alkyl (meth) acrylate in the range of 15 to 50% by weight. Here, when the compounding ratio of the lower alkyl (meth) acrylate in the hydrophilic polymer portion is less than 15% by weight, the coating film strength in a high temperature environment is insufficient, and when it exceeds 50% by weight, Since the alkyl (meth) acrylate is hydrophobic, the hydrophilicity of the coating film is lowered and the antifogging property is lowered. Further, from the balance of coating strength, antifogging property, adhesiveness and the like under a high temperature environment, the vinyl monomer having a crosslinkable functional group is 5 to 20% by weight and the hydrophilic vinyl monomer is 40 to 70% by weight. , The lower alkyl (meth) acrylate is particularly preferably in the range of 25 to 40% by weight.

Next, the hydrophobic polymer portion of the block or graft copolymer is composed of a lower alkyl (meth) acrylate and a vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group. .

The lower alkyl (meth) acrylate is an alkyl (meth) acrylate having a linear or branched alkyl group having 1 to 4 carbon atoms as described above, and at least one of them is used. To be done.

As the vinyl monomer having a sulfonic acid group, for example, 2-sulfoethyl (meth) acrylate, 3
-Sulfopropyl (meth) acrylate, 2-acrylamido-2-methylpropanesulfonic acid and the like can be mentioned. Examples of the vinyl monomer having a carboxyl group include (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and the like. Examples of the vinyl monomer having a phosphoric acid group include mono (2- (meth) acryloyloxyethyl) acid phosphate and the like. Of these, acrylic acid is particularly preferably used in terms of copolymerizability.

The proportion of the hydrophobic polymer portion is usually 70 to 99% by weight of the lower alkyl (meth) acrylate and 1 to 30 of the vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group. It is in the range of% by weight. When the lower alkyl (meth) acrylate is less than 70% by weight or the vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group exceeds 30% by weight, the adhesion between the coating film and the resin material is lowered. To do. On the other hand, lower alkyl (meth)
When the acrylate content exceeds 99% by weight or the vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group is less than 1% by weight, the transparency of the coating film is lowered.
Further, in view of the balance of adhesion, transparency, etc., the lower alkyl (meth) acrylate is 80 to 95% by weight, and the vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group is 5 to 20% by weight. Ranges are particularly preferred.

As described above, the hydrophilic polymer portion of the block or graft copolymer causes the coating film to be formed to have antifogging properties, and has a crosslinkable functional group introduced into the hydrophilic polymer portion. By carrying out heat curing, it is possible to enhance the durability of water resistance and antifogging property of the coating film. Further, by copolymerizing a lower alkyl (meth) acrylate with the hydrophilic polymer portion, it is possible to enhance the strength of the coating film in a high temperature environment.

Further, the hydrophobic polymer portion of the block or graft copolymer contributes to the adhesion between the coating film formed and the resin material, and the hydrophobic polymer portion has a sulfonic acid group,
The transparency of the coating film can be imparted by introducing a carboxyl group or a phosphoric acid group.

The composition ratio of the hydrophilic polymer portion to the hydrophobic polymer portion in the block or graft copolymer is 5 to 95% by weight for the hydrophilic polymer portion and 5 to 95 for the hydrophobic polymer portion. It is desirable to be in the range of% by weight.
If the hydrophilic polymer portion is less than 5% by weight or the hydrophobic polymer portion is more than 95% by weight, the hydrophilicity of the block or graft copolymer decreases, and the block or graft copolymer is mixed with it. Interaction with the surface active agent is weakened, and the antifogging property and antifogging durability of the coating film are reduced.
On the other hand, if the hydrophilic polymer portion exceeds 95% by weight or the hydrophobic polymer portion is less than 5% by weight, the adhesiveness between the coating film and the resin material decreases. Further, from the balance of antifogging property, antifogging durability, adhesiveness, etc., the composition ratio of the hydrophilic polymer portion and the hydrophobic polymer portion in the block or graft copolymer is 50 to 50% for the hydrophilic polymer portion. A range of 95% by weight and 5 to 50% by weight of the hydrophobic polymer portion is particularly preferable.

A block or graft copolymer consisting of a hydrophilic polymer portion and a hydrophobic polymer portion can be synthesized by a conventional method. However, in view of easy industrial productivity and many performances, polymeric peroxide and polyazo The compound is preferably synthesized by radical polymerization using a radical copolymerizable group-containing peroxide as a polymerization initiator. In this case, as the radical polymerization initiator to be used, a conventionally known compound having two or more peroxy bonds or azo bonds in one molecule and a compound having a radical copolymerizable group and a peroxy group in one molecule are used. As the polymerization method, a usual bulk polymerization method, suspension polymerization method, solution polymerization method, emulsion polymerization method or the like is adopted, but the solution polymerization method is preferable from the viewpoint of easy handling and the like.

Solvents used when the block or graft copolymer is synthesized by the solution polymerization method include alcohols such as methanol, ethanol, isopropanol, n-butanol and diacetone alcohol. -Solvent, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, glycol ether solvent such as propylene glycol monoethyl ether, methyl ethyl ketone, methyl isobutyl ketone, Examples thereof include ketone solvents such as cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, amide solvents such as dimethylformamide, and aromatic hydrocarbon solvents such as toluene and xylene. Of these, alcohol solvents, glycol ether solvents, ketone solvents and mixed solvents thereof are preferably used from the viewpoint of solubility of the block or graft copolymer.

Next, a typical synthesis example of a block copolymer will be described below by using a polymeric peroxide as a polymerization initiator. First, by polymerizing a monomer forming a hydrophilic polymer portion using a polymeric peroxide, a peroxy bond-containing hydrophilic polymer having a peroxy bond introduced into the chain is obtained. When a monomer constituting the hydrophobic polymer portion is added to this and polymerization is carried out, the peroxy bond in the hydrophilic polymer chain is cleaved to efficiently obtain a block copolymer. By carrying out the polymerization in such an order, a block copolymer having excellent solubility in a solvent can be obtained. It should be noted that the monomer constituting the hydrophobic polymer portion is polymerized first to obtain a peroxy bond-containing hydrophobic polymer, and then the monomer constituting the hydrophilic polymer portion is polymerized to obtain a block copolymer. The combination may be synthesized.

A typical synthesis example of the graft copolymer will be described using a radical copolymerizable group-containing peroxide as a polymerization initiator. First, under the condition that the peroxy bond of the radical-copolymerizable group-containing peroxide is not cleaved, by copolymerizing with a monomer that constitutes the hydrophilic polymer part by a polymerization initiator that is usually used, the hydrophilicity containing the peroxy bond is increased. A polymer is obtained, and then, under the condition that this peroxy bond is cleaved, the monomer that constitutes the hydrophobic polymer part is added to this and polymerization is carried out, and the peroxy bond in the hydrophilic polymer is cleaved. A graft copolymer can be obtained efficiently.
This graft copolymer has excellent solubility in a solvent. Incidentally, the monomer constituting the hydrophobic polymer portion is first polymerized to obtain a peroxy bond-containing hydrophobic polymer, and then the monomer constituting the hydrophilic polymer portion is polymerized to obtain a graft copolymer. The combination may be synthesized.

Next, a dispersion of a metal oxide surface-modified with a silane coupling agent will be described. As described above, a dispersion of silicon oxide, aluminum oxide, or the like is used as the dispersion of the metal oxide, but since the dispersion of the silicon oxide sol is the most preferable, the dispersion of the silicon oxide sol is described below. Will be described as a target.

When the dispersion of silicon oxide sol is an aqueous dispersion, the dispersion of silicon oxide sol is replaced with an organic solvent before use. That is, for example, a method in which a water-soluble organic solvent is added to an aqueous dispersion and the operation of distilling off water is repeated to replace the organic solvent with a desired organic solvent can be used. In this case, as the organic solvent to be used, from the viewpoint of the stability of the dispersion and the solubility of the block or graft copolymer, the alcohol solvent and the glycol ether are used.
Tellurium-based solvents, ketone-based solvents and mixed solvents thereof are preferred.

Next, the dispersion of the silicon oxide sol is surface-modified with a silane coupling agent. The surface-modified dispersion is stably dispersed in the block or graft copolymer and is transparent. It is possible to form a simple coating film.

The silane coupling agent for modifying the surface of the silicon oxide sol is an organic silicon compound having an alkoxysilyl group in the molecule, and is a compound represented by the following formula (1).

R_n-Si (OR₁)_4-n (1) However, n is 1 to 3, preferably 1 or 2, R is an organic group,
R₁Is a methyl group (CH _Three) Or ethyl group (C_TwoH_Five)so
Is desirable.

Examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxy. Propyltrimethoxysilane, γ-aminopropyltrimethoxysilane and the like are industrially available. The surface modification of the silicon oxide sol can be carried out relatively easily with these silane coupling agents, and one or more of these are preferably used.

In the case of a silicon oxide sol which is not surface-modified with a silane coupling agent, the dispersion state becomes unstable in the block or graft copolymer, causing the particles to agglomerate. It is easy to cause whitening and spots on the coating film. This is because, since many silanol groups are present on the surface of the silicon oxide particles, the polarity of the silicon oxide particles is remarkably high, and in the block or graft copolymer, the polarity of the hydrophilic polymer portion is high. It is considered that since the hydrophobic polymer portion has a low polarity, it is difficult to balance the polarity with the silicon oxide particles to be blended, the dispersibility of the particles is impaired, and the particles easily aggregate.

However, when the surface of the silicon oxide particle is modified with the silane coupling agent, the silanol group existing on the surface of the silicon oxide particle reacts with the alkoxy group of the silane coupling agent, and the surface of the silicon oxide particle reacts. The silanol groups are reduced. Therefore, the polarity of the silicon oxide particles can be appropriately reduced, the polarity balance with the block or graft copolymer can be well adjusted, and the dispersion stability of the silicon oxide particles can be improved.

Further, since the dispersion of the silicon oxide sol can introduce various organic functional groups on the particle surface by surface modification, when used in the antifogging composition, the organic component which is an organic component is used. Familiarity (affinity) between the resin and the silicon oxide sol, which is an inorganic component, can be improved.
Moreover, it is possible to chemically bond the organic component and the inorganic component. Therefore, the coating film becomes strong, and the hardness, scratch resistance, heat resistance, etc. of the coating film can be improved.

As the dispersion of the silicon oxide sol, for example, as an aqueous dispersion, Sno-tex-O and Sno-tex-
N [all manufactured by Nissan Chemical Industries, Ltd., trade name], etc. are MIBK-ST, which is a methyl isobutyl ketone dispersion as an organic solvent dispersion, and IP, which is an isopropanol dispersion.
A-ST (all manufactured by Nissan Chemical Industries, Ltd., trade name) and the like can be mentioned.

As a method of surface modification, a silane coupling agent is added to a dispersion of silicon oxide sol dispersed in an organic solvent, and the reaction is carried out at a temperature of room temperature to 80 ° C. A dispersion of silicon oxide sol is obtained.

The thus-obtained dispersion of the surface-modified silicon oxide sol can be stably dispersed in the antifogging composition to obtain a transparent coating film. In the antifogging agent composition, one kind of the surface-modified silicon oxide sol dispersion may be used, or two or more kinds thereof may be used in combination, and the solid content of the block or graft copolymer may be used. Is usually 1
0 to 95% by weight, solid content of the dispersion is 5 to 90% by weight
It is. The solid content of the block or graft copolymer exceeds 95% by weight, or the dispersion contains 5% by weight.
When the amount is less than the above, the effect of adding the dispersion is not sufficiently exhibited, and the effect of improving the hardness and scratch resistance of the coating film is not recognized so much. On the other hand, the solid content of the block or graft copolymer is less than 10% by weight, or the dispersion is 90% by weight.
When it exceeds, the antifogging sustainability and the adhesiveness of the coating film deteriorate. Furthermore, from the viewpoint of the balance of hardness, scratch resistance, flexibility, adhesion, etc. of the coating film, the solid content of the block or graft copolymer is 20 to 70% by weight, and the solid content of the dispersion is 30 to 80% by weight. The range of% is particularly preferable.

Next, the surfactant blended in the antifogging composition will be described. The surfactant acts synergistically with the hydrophilic polymer portion of the block or graft copolymer to exert an effect of remarkable hydrophilic property, and further, the interaction with the hydrophilic polymer portion causes the surfactant to be coated. Since it gradually migrates from the inside of the film to the surface of the coating film, it exerts the function of maintaining superior antifog properties and long-term antifog properties. Further, even if the surfactant that has migrated to the surface of the coating film is washed away with water, it is replenished from the inside of the coating film to the surface of the coating film to compensate for it, so the antifogging property of the coating film surface is always maintained.

The surfactant is generally used, and is one or more selected from nonionic surfactants, anionic surfactants, cationic surfactants and zwitterionic surfactants. Surfactants are used.

Examples of nonionic surfactants include polyoxyethylene higher alcohol ethers such as polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether, and polyoxyethylene oleyl ether, and polyoxyethylene lauryl ethers. Polyoxyethylene alkylaryl ethers such as oxyethylene octylphenol, polyoxyethylene nonylphenyl ether, polyoxyethylene acyl esters such as polyoxyethylene glycol monostearate, polypropylene glycol ethylene Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, and other polyoxyethylene sorbitan fatty acid esters, alkyl phosphates, polyoxyethylene alkyl etherein Phosphoric acid esters such as esters, Sugar Sugar - esters, cellulose - sweated - ethers, and the like. Particularly, among these, polyoxyethylene higher alcohol ethers and polyoxyethylene alkyl aryl
Luthers are preferably used in terms of compatibility with the block or graft copolymer contained in the present antifog composition.

Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium oleate, higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, and alkylnaphthalenesulfone. Alkylbenzene sulfonates such as sodium acid salts and alkylnaphthalene sulfonates, naphthalene sulfonic acid formalin condensates, dialkyl sulfosuccinates, dialkyl phosphate salts, polyoxyethylene monkeys such as sodium polyoxyethylene alkylphenyl ether sulfate Examples thereof include fate salts and the like. In particular, among these,
A dialkyl sulfosuccinate is preferably used from the viewpoint of compatibility with the block or graft copolymer contained in the present antifog composition.

Examples of the cationic surfactant include amine salts such as ethanolamines, laurylamine acetate, triethanolamine monoformate, stearamidoethyldiethylamine acetate, lauryltrimethylammonium chloride and stearyltrimethylammonium chloride. , Dilauryl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride,
Examples thereof include quaternary ammonium salts such as lauryl dimethyl benzyl ammonium chloride and stearyl dimethyl benzyl ammonium chloride.

Examples of the zwitterionic surfactant include fatty acid type amphoteric surfactants such as dimethylalkyllaurylbetaine and dimethylalkylstearylbetaine, sulfonic acid type amphoteric surfactants such as dimethylalkylsulfobetaine, and alkylglycine. Can be mentioned.

Among the above-mentioned surfactants, the nonionic surfactants are particularly preferably used in order to give a transparent anti-fog coating film without impairing the dispersion stability of the dispersion. The mixing ratio of these surfactants is in the range of 0.1 to 30% by weight based on the total solid content of the dispersion of the silicon oxide sol surface-modified with the block or graft copolymer and the silane coupling agent. is there. 0.1% by weight of surfactant
If it is less than 30%, the antifogging sustainability is lowered, and if it exceeds 30% by weight, the hardness and scratch resistance of the coating film are lowered. Further, from the viewpoint of the balance of antifogging sustainability, practical coating hardness, scratch resistance, etc., the mixing ratio of the surfactant is particularly preferably in the range of 0.5 to 20% by weight based on the total solid content. preferable.

The method for preparing the antifogging composition is not particularly limited, and various methods can be used, but the following method is preferable because the antifogging composition can be prepared efficiently. . That is, after the block or graft copolymer is polymerized under the above-mentioned polymerization conditions, a dispersion of the silicon oxide sol surface-modified with a silane coupling agent is heated or unheated in the copolymer solution. Mix thoroughly to stabilize the dispersion. The antifogging agent composition can be prepared by homogeneously mixing a surfactant with this, if necessary.

If necessary, the antifogging agent composition may further contain various additives such as colorants such as pigments and dyes, leveling agents, curing catalysts and ultraviolet absorbers. Further, the method of forming the coating film is to apply an antifogging agent composition to various resin plates such as acrylic resin, polycarbonate resin and the like, which are the objects to be coated, or various resin molded products, and then to 70 to 140 ° C.
A coating film is formed by heating and curing in the temperature range of 5 to 60 minutes. However, in this case, it is necessary to set the curing temperature below the thermal deformation temperature of the resin material. As a result, the various resin materials on which the anti-fog coating film is formed can maintain not only the appearance and adhesion of the coating film, but also the anti-fog property and the coating film strength in an actual environment for an extremely long period of time.

The antifogging agent composition may be applied by a conventional coating method such as an air spray coating method.
Rotation atomization coating method, electrostatic coating method, roll coat method, spin coat method, film applicator method, bar coater
Method, flow coating method, dip coating method, brush coating method and the like are applied.

At the time of coating, it is diluted with various solvents to a viscosity suitable for the above-mentioned coating method. Examples of the solvent used in this case include alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and diacetone alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl carbitol. Glycol, butyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether and other glycol ether solvents, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketone solvents,
Examples thereof include ester solvents such as ethyl acetate and butyl acetate, amide solvents such as dimethylformamide, and aromatic hydrocarbon solvents such as toluene and xylene. Of these, alcohol-based solvents, glycol ether-based solvents, ketone-based solvents, and mixed solvents thereof are preferably used in order to dissolve the components of the composition well and to adjust the viscosity.

The dry film thickness of the coating film formed from the composition is preferably in the range of 1 to 30 μm, and more preferably 3 to 15 μm in order to obtain good smoothness and durability of the coating film. .

Further, as an environment for coating the antifogging composition, it is necessary that the relative humidity is 60% or less.
This is because the composition is very hydrophilic and has a relative humidity of 60.
This is because when coating is performed in an environment exceeding 100%, moisture in the air is absorbed, whitening occurs in the coating film after heat curing, and the transparency decreases.

According to the embodiment of the present invention as described above, the following effects can be obtained. (1) By containing a silicon oxide sol surface-modified with a silane coupling agent, the physical properties of silicon oxide itself and the affinity of the resin, which is the coating object based on the silane coupling agent, are increased, and the coating film Hardness, scratch resistance, heat resistance, etc. can be improved. (2) The silicon oxide sol is surface-modified with a silane coupling agent, can be stably dispersed in a block or graft copolymer, and can form a transparent coating film. (3) Improvement of coating strength, adhesion, and heat resistance in a high temperature environment by using a lower alkyl (meth) acrylate as a monomer forming the hydrophilic polymer portion of the block or graft copolymer Can be achieved. (4) Good antifogging property can be imparted based on the appropriate hydrophilicity of the hydrophilic polymer portion of the block or graft copolymer. (5) The hydrophobic polymer portion of the block or graft copolymer can enhance the adhesion between the coating film and the resin as the article to be coated. (6) The transparency of the coating film can be imparted by introducing a sulfonic acid group, a carboxyl group or a phosphoric acid group into the hydrophobic polymer portion of the block or graft copolymer. (7) By blending a surfactant, the surfactant gradually migrates from the inside of the coating film to the coating surface surface due to the interaction with the hydrophilic polymer portion of the block or graft copolymer, which is more excellent. Anti-fog property and anti-fog persistence can be achieved.

[0052]

EXAMPLES Next, the present invention will be described in more detail with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to these Examples.

The coating film performance was evaluated as follows. (Appearance test) It was evaluated by visual observation according to the following criteria.

◯: Completely transparent and no abnormalities are observed. X: Whitening occurs, and a decrease in transparency is recognized. (Anti-fogging test) 2 coated plates in a constant temperature room adjusted to 20 ° C
After being left for a period of time, exhaled air was blown onto the surface of the coating film, and the occurrence of haze was visually observed and evaluated according to the following criteria.

◯: No fogging is observed at all. Δ: Cloudy occurs for a moment but disappears immediately. X: Significant fogging is observed. (Water / fogging resistance test) After immersing the coated plate in 40 ° C warm water for 48 hours, the coated plate was left in a thermostatic chamber adjusted to 20 ° C for 2 hours, and then exhaled air was blown to the surface of the coated film to prevent fogging. It was evaluated by visual observation according to the following criteria.

◯: No fogging is observed at all. Δ: Cloudy occurs for a moment but disappears immediately. X: Significant fogging is observed. (Adhesion test) An adhesion test was performed in accordance with JIS K 5400 8.5.1.

Good: No peeling was observed at all, and perfect adhesion was observed. Δ: Peeling is slightly observed. X: Remarkable peeling is recognized. (Pencil hardness test) The pencil hardness test was performed according to JIS K 5400 84.2. (Scratch resistance test) Using a steel wool # 0000, 1
The appearance after rubbing the 10 reciprocating coating film under a kg load was visually observed and evaluated according to the following criteria.

◯: No scratch is observed. Δ: Slight scratches are observed, but transparency is not impaired at all. X: Significant scratches were observed and the transparency was impaired. (Accelerated weather resistance test) The coated plate is exposed for 400 hours in a sunshine carbon arc lamp type accelerated weather resistance tester, and the above-mentioned method for antifogging, adhesion, pencil hardness, and scratch resistance,
Tested and evaluated according to the standard. (Synthesis Example 1, synthesis of block copolymer) 200 g of ethylene glycol monoethyl ether was charged into a flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, and 70 ° C while blowing nitrogen gas. The mixture was heated and stirred until. In addition, 4 g of polymeric peroxide represented by the following formula (2) and N, N-dimethylacrylamide 50
g, N-methyl acrylamide 8 g, methyl methacrylate 12 g, and ethylene glycol monoethyl ether 40 g, a monomer mixture was added dropwise over 2 hours, and the reaction was further continued for 2 hours.

Thereafter, further methyl methacrylate 28 was added.
g, a monomer mixture consisting of 2 g of acrylic acid was added dropwise over 30 minutes, and the mixture was reacted at 80 ° C. for 5 hours and then cooled,
A block copolymer solution having a solid content of 30% was obtained (in the table, abbreviated as copolymer solution synthesis example 1). - use in (2) (Synthesis Example 2, Synthesis of graft copolymer) Synthesis Example 1 - _{[CO (CH 2) 4 COO (} C 2 H 4 O) 3 CO (CH 2) 4 COOO ] ₁₀ The reactor was charged with 200 g of propylene glycol monomethyl ether, heated and stirred to 85 ° C. while blowing nitrogen gas, and t-butylperoxyoctanoate 6 was added.
g, t-butyl peroxymethacryloxyethyl carbonate 6 g, N-methyl acrylamide 10 g, 2
30 g of a monomer mixture consisting of 10 g of hydroxyethyl methacrylate, 66 g of N, N-dimethylacrylamide and 40 g of propylene glycol monomethyl ether.
The mixture was added dropwise over minutes, and the reaction was further performed for 2 hours.

Thereafter, the mixture was further heated to 110 ° C. and a monomer consisting of 20 g of methyl methacrylate, 2 g of acrylic acid and 40 g of propylene glycol monomethyl ether was added.
The mixture was added dropwise over 30 minutes, and the reaction was continued for 4 hours. Then, this was cooled to obtain a graft copolymer solution having a solid content of 30% (abbreviated as copolymer solution synthesis example 2 in the table). (Synthesis Example 3, Synthesis of Surface-Modified Silicon Oxide Sol Dispersion) SNO-TEX-O [Nissan Chemical Industry Co., Ltd., trade name], which is an aqueous dispersion of silicon oxide sol in a round-bottomed flask.
200 g of isopropanol and 200 g of isopropanol were charged, and 200 g of water and isopropanol were distilled off at a temperature of 40 ° C. under reduced pressure with an evaporator, and isopropanol 20 was added again.
This operation was performed once more by adding 0 g and using an evaporator. Then, propylene glycol monomethyl ether
The same operation was performed by adding 200 g of ter with an evaporator and completely distilling off residual water to obtain a silicon oxide sol dispersion substituted with a propylene glycol monomethyl ether and isopropanol mixed solvent. .

Next, 8 g of A-163 [methyltrimethoxysilane, manufactured by Nippon Unicar Co., Ltd., trade name] was charged into this dispersion as a silane coupling agent and heated to 80
By maintaining the temperature at 4 ° C. for 4 hours, a surface-modified silicon oxide sol dispersion having a solid content of 20% was obtained (abbreviated as Dispersion Synthesis Example 3 in the table). (Synthesis Example 4, Synthesis of Surface-Modified Silicon Oxide Sol Dispersion) 200 g of MIBK-ST (manufactured by Nissan Chemical Industries, Ltd.), which is a methyl isobutyl ketone dispersion of silicon oxide sol in a round-bottomed flask, SH6040 [γ-glycidoxypropyltrimethoxysilane as a silane coupling agent, Toray Dow Corning Silicone Co., Ltd.
Manufactured, trade name] 18 g and propylene glycol monomethyl ether 60 g were charged, heated and kept at a temperature of 60 ° C. for 8 hours. As a result, a surface-modified silicon oxide sol dispersion having a solid content of 20% was obtained (abbreviated as Dispersion Synthesis Example 4 in the table). Example 1 To 190 g of the block copolymer solution obtained in Synthetic Example 1, 15 g of the surface-modified silicon oxide sol dispersion obtained in Synthetic Example 3 was added and sufficiently stirred and mixed to obtain a surfactant. Nonion NS-212 [polyoxyethylene nonylphenyl ether, manufactured by NOF CORPORATION, trade name]
An antifogging agent composition was prepared by adding 0.3 g and further stirring and mixing.

Next, using propylene glycol monomethyl ether as a diluting solvent, the viscosity cup No.
4. Dilute at 20 ° C. for 15 seconds at 4 and coat with an air spray on a transparent acrylic plate with a thickness of 1 mm.
It was dried and cured at 0 ° C. for 60 minutes. Furthermore, after standing at room temperature for 1 day, the coating film performance was evaluated. The blending ratio of each component of the present antifog composition, the article to be coated, the dry curing conditions and the dry film thickness are shown in Table 1, and the coating film performance is shown in Table 5.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

[Table 3]

[0066]

[Table 4] In Tables 1 to 4, each abbreviation has the following meaning. MIBK-ST: Dispersion of methyl isobutyl ketone of silicon oxide sol (solid content 20%), trade name Lapisol B-90 manufactured by Nissan Chemical Industries, Ltd .: Sodium dioctyl sulfosuccinate (solid content 90%), NOF Corporation Brand name manufactured by NONION NS-212: Polyoxyethylene nonylphenyl ether (solid content 100%), trade name manufactured by NOF CORPORATION AC: Transparent acrylic plate (thickness 1 mm) PC: Transparent polycarbonate -Bonette plate (thickness 1mm)

[0067]

[Table 5]

[0068]

[Table 6]

[0069]

[Table 7]

[0070]

[Table 8]

(Examples 2 to 10) The antifogging agent composition was prepared in the same manner as in Example 1 with the compounding ratios shown in Tables 1 to 4, and then coating films were formed on various transparent resin plates. . The compounding ratio of each component in the antifogging agent composition, the article to be coated, the dry curing conditions and the dry film thickness are shown in Tables 1 to 4, and the coating film performance is shown in Tables 5 to 8. Comparative Example 1 To 200 g of the block copolymer solution obtained in Synthesis Example 1 was added 6 g of Lapisol B-90 [sodium dioctyl sulfosuccinate, a trade name of NOF Corporation] as a surfactant. An antifogging composition was prepared by thoroughly mixing with stirring.

Next, using propylene glycol monomethyl ether as a diluting solvent, the viscosity cup No.
No. 4 was diluted at a temperature of 20 ° C. for 15 seconds, coated with an air spray on a transparent polycarbonate board having a thickness of 1 mm, and dried and cured at 130 ° C. for 30 minutes. Furthermore, after standing at room temperature for 1 day, the coating film performance was evaluated. The blending ratio of each component of the present antifogging agent composition, the article to be coated, the dry curing conditions and the dry film thickness are shown in Table 4, and the coating film performance is shown in Table 8. Comparative Example 2 To 140 g of the graft copolymer solution obtained in Synthesis Example 2, 90 g of MIBK-ST [trade name of Nissan Chemical Industries, Ltd.] as a silicon oxide sol dispersion without surface modification was added. By sufficiently stirring and mixing, and then adding 6 g of nonion NS-212 [polyoxyethylene nonylphenyl ether, trade name of NOF CORPORATION] as a surfactant, and further stirring and mixing to prepare an antifogging composition Was prepared.

Next, using propylene glycol monomethyl ether as a diluting solvent, the viscosity cup No.
4. Dilute at 20 ° C. for 15 seconds at 4 and coat with an air spray on a transparent acrylic plate with a thickness of 1 mm.
It was dried and cured at 0 ° C. for 60 minutes. Furthermore, after standing at room temperature for 1 day, the coating film performance was evaluated. The blending ratio of each component of the present antifogging agent composition, the article to be coated, the dry curing conditions and the dry film thickness are shown in Table 4, and the coating film performance is shown in Table 8.

As shown in Tables 5 to 8, the coating films obtained from the antifogging compositions of Examples 1 to 10 had appearances,
It has good coating performance in terms of anti-fog property, water-proof anti-fog property, adhesion, pencil hardness and scratch resistance, and also in anti-fog property, adhesion, pencil hardness and scratch resistance after accelerated weather resistance test. It shows good coating performance, which is the same as the initial coating performance, and has long-term anti-fog durability and coating durability.

On the other hand, as shown in Table 8, in Comparative Example 1, since the surface-modified dispersion was not mixed, the hardness of the coating film was low and the scratch resistance was also poor. Further, in Comparative Example 2, since the dispersion of the silicon oxide sol which has not been surface-modified is blended, whitening occurs in the coating film, which causes a problem in the appearance of the coating film.

The technical idea understood from the above embodiment will be described below. (1) The antifogging agent composition according to claim 1, wherein the dispersion of the metal oxide is a dispersion of a silicon oxide sol. According to this structure, the reactivity with the silane coupling agent is good, the affinity with the resin as the coating object can be increased, and the hardness, scratch resistance, heat resistance, etc. of the coating film are improved. be able to. (2) The antifogging agent composition according to (1), wherein the dispersion of the silicon oxide sol is a dispersion of the silicon oxide sol in an organic solvent. According to this structure, the dispersion stability of the dispersion of the silicon oxide sol in the antifogging composition can be improved. (3) The antifogging agent composition according to claim 3, wherein the surfactant is a nonionic surfactant. According to this structure, a more transparent antifogging coating film can be obtained without impairing the dispersion stability of the metal oxide dispersion.

[0077]

As described above in detail, the antifog composition of the present invention has the following excellent effects.

According to the first aspect of the present invention, the antifogging property and its durability can be favorably maintained, and the hardness and scratch resistance of the antifogging coating film are excellent. Furthermore, the appearance, adhesion, etc. of the coating film formed from the antifogging composition are good. Therefore, the antifogging composition of the present invention, various transparent resin glasses, sunglasses,
It is suitable for applications such as goggles, lenses, facepieces and helmet shields.

According to the second invention, it is possible to improve the strength, adhesion and heat resistance of the coating film in a high temperature environment. According to the third invention, more excellent antifogging property and long-term antifogging property can be exhibited.

Claims (3)

[Claims] 1. A block copolymer or graft copolymer, and a dispersion of a metal oxide surface-modified with a silane coupling agent, wherein the block copolymer or graft copolymer is N. -Hydrophilicity formed from a hydrophilic vinyl monomer and a vinyl monomer having at least one cross-linking functional group selected from the group consisting of a methylol group, an N-methyl ether group and a hydroxyl group -Fogging agent composition comprising a hydrophobic polymer portion formed from a polymerizable polymer portion, a vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group, and a lower alkyl (meth) acrylate . 2. The antifogging agent according to claim 1, wherein the monomer forming the hydrophilic polymer portion of the block copolymer or the graft copolymer further contains a lower alkyl (meth) acrylate. Composition. 3. A surfactant is further blended with the antifogging composition according to claim 1 or 2, and the blending ratio of the surfactant is the block copolymer or graft copolymer and the silane cup. An antifogging agent composition, which is 0.1 to 30% by weight based on the total solid content of a dispersion of a metal oxide surface-modified with a ring agent.