JP2005146227A - Antifogging coating, antifogging formed article and method for producing antifogging coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antifogging coating obtained by a simple polymerization method, and forming a transparent haze-preventing film showing an extremely inconspicuous appearance of unevenness generated by the flow of water droplets attached on the coated film, and an antifogging formed article obtained by applying the same and drying. <P>SOLUTION: This antifogging coating contains a polymer obtained by polymerizing a polymerizable monomers containing at least 1 kind of (A1 group) polymerizable monomers which are the metal salts of sulfonic acids having a >8C long chain alkyl, at least 1 kind of (A2 group) polymerizable monomers which are the metal salts of sulfonic acids having an aryl or ≤8C alkyl, and at least 1 kind of (B group) monomers co-polymerizable with both of the A1 group and A2 group and also slightly soluble, hardly soluble or insoluble in water. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antifogging paint, an antifogging molded article obtained by applying and drying the antifogging paint, and a method for producing the antifogging paint.

  In lenses such as lamps, fogging may occur on the inner surface, which is difficult to wipe off depending on weather conditions. Such fogging is a problem particularly in applications where the user places importance on the appearance, such as automobile lamps. In addition, in covering materials used for agricultural houses, clouding due to moisture filled inside prevents the transmission of sunlight, and fine droplets due to clouding grow further and become large, and fall on the crop to produce crops. The problem of rotting or discoloring occurs.

  In order to prevent fogging of the surface of molded articles such as lenses and covering materials as described above, it is known to impart antifogging properties to the surface of molded articles and the like. Specifically, a method of applying a surfactant, a method of kneading and molding a surfactant in a resin, a method of applying a hydrophilic inorganic filler such as silica or titanium oxide, a hydrophilic inorganic filler and a surfactant The method of mixing and apply | coating is mentioned. However, these methods have a common problem in that the hydrophilic substance on the surface is washed away by the attached water droplets, so that the antifogging durability and water resistance are lacking.

  In order to improve the above-described drawbacks, many methods using a hydrophilic polymer have been proposed. For example, in JP-A-6-107967, JP-A-6-212146 and JP-A-11-228940, a block or graft copolymer composed of a hydrophilic polymer segment and a hydrophobic polymer segment is used as a main component. A heat curable antifogging agent composition is disclosed. However, such a thermosetting antifogging agent composition generally has a high curing temperature, and has a problem that it is difficult to use for a thermoplastic resin lens such as polymethyl methacrylate, which is thermally deformed at a relatively low temperature. In order to obtain a copolymer, there was a problem that a special polymerization initiator and a polymerization method had to be used.

  In addition, in JP-A-6-107967, JP-A-11-116892 and the like, an ultraviolet curable antifogging agent composition is disclosed. In this case, although there is no fear of thermal deformation, A molded product having a complicated curved surface has a problem that it is difficult to uniformly irradiate ultraviolet rays.

  As another method, a method of applying an acrylic emulsion is shown. For example, a method of improving antifogging durability and water resistance by using a silane coupling agent having a polymerization reactive functional group in an aqueous emulsion polymerization method (see Patent Document 1), and an acrylic emulsion having surface activity. A method of applying an anti-fogging paint blended with an agent, a completely saponified polyvinyl alcohol, etc. (see Patent Document 2) has been proposed. However, these water-based anti-fogging coatings commonly contain a large amount of water-soluble components, so that when the water adhering to the coating film flows and dries, it becomes uneven in appearance, which causes defects such as appearance. Have the disadvantage of causing For this reason, there is a problem that it cannot be used for applications such as glass and automobile lamps that emphasize the appearance in particular.

In addition, organic antifogging paints as described above are generally poor in heat resistance, and antioxidants etc. are added for use in heat-sensitive applications such as automobile lamps. There is a problem that such additives tend to have various adverse effects such as uneven appearance due to moisture, discoloration, and decrease in antifogging properties. In order to prevent the anti-fogging property from being easily lowered even if heat is applied from the surface of the polymer structure, introduction of a hydrophilic group having a high polarity is effective, and in particular, when a monomer that is a metal salt of sulfonic acid is copolymerized The fact that it is effective is also described in the above-mentioned Patent Document 3 by the present inventors.
JP-A-7-233270 JP-A-6-306324 JP 2003-82272 A

However, a polymer obtained by copolymerizing many monomers that are metal salts of sulfonic acid generally tends to have poor water resistance, and tends to cause peeling of the coating film due to moisture. In order to suppress this, it is effective to combine with a water-insoluble monomer, but in general, the compatibility between the two is too bad, so the copolymer cannot be successfully copolymerized and is a residual metal salt of sulfonic acid. Monomers and their homo-oligomers tend to cause uneven appearance due to the aforementioned moisture.
The present invention has been made in view of the above-described conventional problems, and is obtained by a simple polymerization method, and the appearance unevenness generated when water droplets adhering to the coating film flows is extremely inconspicuous, and has heat resistance. The present invention relates to an antifogging paint that can form a transparent antifogging coating film excellent in the above, an antifogging molded product obtained by applying and drying the coating, and a method for producing an antifogging paint that can be easily obtained.

The present invention was made as a result of diligent examination of the above-described problems,
(1) At least one selected from a polymerizable monomer group (hereinafter referred to as A1 group) which is a metal salt of a sulfonic acid having a long-chain alkyl group having 8 or more carbon atoms, and an aryl group or 8 carbon atoms. At least one selected from a polymerizable monomer group (hereinafter referred to as “Group A2”) which is a metal salt of a sulfonic acid having fewer alkyl groups, copolymerizable with Groups A1 and A2, and slightly soluble in water. An anti-fogging paint comprising a polymer obtained by polymerizing a polymerizable monomer containing at least one kind of a hardly soluble or insoluble monomer group (hereinafter referred to as group B). .

  (2) The polymer is 100 parts by weight of the total amount of polymerizable monomers, and the total amount of polymerizable monomers selected from the groups A1 and A2 is 2 to 10 parts by weight. It is related with the anti-fogging coating material of the said (1) description formed by polymerizing the polymerizable monomer whose selected polymerizable monomer is 25-78 weight part.

（化学式（１）においてＲ_１はＣ_８〜Ｃ_１８のアルキル基である。また^＋Ｍはアルカリ金属イオンである。）で表される単量体を含み、
前記Ａ２群が下記化学式（２）

で表される単量体、および、下記化学式（３）

（化学式（２）、化学式（３）において、Ｒ_２、Ｒ_４はそれぞれ独立にＨ又はＣＨ_３基である。またＲ_３、Ｒ_５はそれぞれ独立に炭素数１〜７の、アルキレン基、又はアリール基の炭素原子から水素原子が１個離脱した基である。また^＋Ｍはアルカリ金属イオンである。）で表される単量体を含む上記（１）または（２）記載の防曇塗料に関する。 (3) The A1 group is represented by the following chemical formula (1)

(In the chemical formula (1), R ₁ is a C _{8 to} C ₁₈ alkyl group, and ⁺ M is an alkali metal ion).
The A2 group is represented by the following chemical formula (2)

And a monomer represented by the following chemical formula (3)

(In the chemical formula (2) and chemical formula (3), R ₂ and R ₄ are each independently H or CH ₃ groups. R ₃ and R ₅ are each independently an alkylene group having 1 to 7 carbon atoms, or An antifogging coating material according to the above (1) or (2), comprising a monomer represented by the formula: ⁺ M is an alkali metal ion. About.

  Particularly, (4) the polymerizable monomer selected from the A1 group and the A2 group is 10/90 to 90/10 in molar ratio (the total amount selected from the A1 group and the A2 group is 100 in molar ratio). It is preferable that

  In addition, (5) the polymer further comprises at least one selected from a nonionic water-soluble monomer group (hereinafter referred to as group C), and the total amount of polymerizable monomers is 100 parts by weight. The antifogging coating material according to any one of (1) to (4) above, which is obtained by polymerizing a polymerizable monomer containing 12 to 77 parts by weight.

  (6) The above (1) wherein the group C includes at least one of a polymerization reactive monomer group having a polyalkylene glycol structure and at least one of an N-alkyl (meth) acrylamide monomer group. ) To (5).

  Moreover, (7) Any of the above (1) to (6) containing the polymer and a colloidal inorganic filler, and containing the colloidal inorganic filler in an amount of 0 to 50 (not including 0) in the total solid content. Or an anti-fogging paint.

  Moreover, this invention is (8) anti-fogging shaping | molding in which the film obtained by apply | coating and drying the anti-fog coating material in any one of said (1)-(7) has coat | covered at least one part of the surface. Product, for example, an automotive lamp, an antifogging sheet, and an antifogging film.

  Further, the present invention provides (9) at least one selected from a polymerizable monomer group (hereinafter referred to as A1 group) which is a metal salt of a sulfonic acid having a long chain alkyl group having 8 or more carbon atoms, and aryl. At least one selected from a polymerizable monomer group (hereinafter referred to as A2 group) which is a metal salt of a sulfonic acid having a group or an alkyl group having less than 8 carbon atoms, and can be copolymerized with A1 and A2 groups. And a process for polymerizing a polymerizable monomer mixture containing at least one monomer group slightly soluble, hardly soluble or insoluble in water in an organic solvent. About.

  According to the present invention, a method for producing an antifogging paint obtained by a simple polymerization method, a transparent antifogging property in which unevenness in appearance that occurs when water droplets attached to a coating film flow is extremely inconspicuous, and has excellent heat resistance, etc. It is possible to provide an antifogging paint capable of forming a coating film and an antifogging molded article obtained by applying and drying the paint.

Hereinafter, the present invention will be described in detail.
The A1 group in the antifogging paint of the present invention is not particularly limited as long as it is a monomer having an alkyl group having 8 or more carbon atoms and a sulfonic acid metal base, but a part thereof is exemplified. Examples thereof include alkali metal salts of sulfopropylmaleic acid monoalkyl ester and alkali metal salts of alkenyl sulfonic acid.

  Further, the A2 group is not particularly limited as long as it is a monomer having an alkyl group or aryl group having 7 or less carbon atoms and having a sulfonic acid metal base, but if a part thereof is exemplified, Styrenesulfonic acid alkali metal salt, methallyloxybenzenesulfonic acid alkali metal salt, allyloxybenzenesulfonic acid alkali metal salt, α-methylstyrenesulfonic acid alkali metal salt, vinylsulfonic acid alkali metal salt, 2-acrylamido-2-methyl Propanesulfonic acid alkali metal salt, (meth) acrylic acid-2-sulfoethyl alkali metal salt, (meth) acrylic acid-3-sulfopropyl alkali metal salt, (meth) acrylic acid-4-sulfobutyl alkali metal salt, ( (Meth) acrylic acid-5-sulfopentyl alkali metal salt, (meth) acrylic acid-6-sulfo Hexyl alkali metal salts, methallyl sulfonic acid alkali metal salts, and the like arylsulfonic acid alkali metal salt.

  As the A1 group and the A2 group, at least one selected from the above monomer group is used. By using these monomers selected from the A1 group and monomers selected from the A2 group in combination, not only can the antifogging and heat resistance be efficiently exhibited, but also the generation of a water-soluble polymer. In addition, the amount of water-soluble residual monomer is suppressed, and the appearance unevenness that occurs when the attached water droplets flow can be improved.

（化学式（１）で、Ｒ１はＣ_８〜Ｃ_１８のアルキル基である。また＋Ｍはアルカリ金属イオンである。）で表される単量体を含むのがより好ましい。このような単量体を用いることで、優れた防曇性と耐熱性を発現させることができるようになる。 Furthermore, A1 group is represented by chemical formula (1)

It is more preferable to include a monomer represented by (in the chemical formula (1), R1 is a C _{8 to} C ₁₈ alkyl group, and + M is an alkali metal ion). By using such a monomer, it becomes possible to exhibit excellent antifogging properties and heat resistance.

で表される単量体、および、化学式（３）

（化学式（２）、化学式（３）において、Ｒ_２、Ｒ_４はそれぞれ独立にＨ又はＣＨ_３基である。またＲ_３、Ｒ_５はそれぞれ独立に炭素数１〜７の、アルキレン基、又はアリール基の炭素原子から水素原子が１個離脱した基である。また＋Ｍはアルカリ金属イオンであることをあらわす。）で表される単量体を含むことが好ましい。このような単量体を用いることにより、スルホン酸基含有量が高く、極めて少量で、効果的に防曇性、耐熱性を保持することが可能になる。 Moreover, A2 group is chemical formula (2).

And a monomer represented by the chemical formula (3)

(In the chemical formula (2) and chemical formula (3), R ₂ and R ₄ are each independently H or CH ₃ groups. R ₃ and R ₅ are each independently an alkylene group having 1 to 7 carbon atoms, or It is preferably a group in which one hydrogen atom is removed from the carbon atom of the aryl group, and + M represents an alkali metal ion. By using such a monomer, the sulfonic acid group content is high and the antifogging property and heat resistance can be effectively maintained with a very small amount.

  The total amount of polymerizable monomers selected from the groups A1 and A2 is preferably 2 to 10 parts by weight, preferably 2 to 5 parts by weight, with the total amount of polymerizable monomers being 100 parts by weight. Further preferred. When the amount is less than 2 parts by weight, the antifogging property and heat resistance, particularly heat resistance, tends to decrease, such being undesirable. On the other hand, when the amount is more than 10 parts by weight, it is not preferable because the appearance unevenness occurs when the water drops flow and the appearance tends to deteriorate.

  The blending ratio of the polymerizable monomer selected from the A1 group and the A2 group is not particularly limited. For example, the A1 group and the A2 group to be used are in a molar ratio of 10/90 to 90/10 (molar ratio, A1 group). And the total amount of polymerizable monomers selected from the A2 group is 100.), it is possible to effectively exhibit antifogging properties and heat resistance.

  The monomer group described in group B is not particularly limited as long as it is a monomer that can be copolymerized with groups A1 and A2 and is slightly soluble, hardly soluble, or insoluble in water. Examples include styrene, α-methylstyrene, 4-methylstyrene, 4-chlorostyrene, 4-bromostyrene, 4-fluorostyrene, 4-methoxystyrene, 4-aminostyrene, 4-nitrostyrene, 4-vinyl. Vinyl aromatic monomers such as phenol and vinyl naphthalene, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate , T-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl ( Acrylate), n-octyl (meth) acrylate, n-dodecyl (meth) acrylate, lauryl (meth) acrylate, trifluoroethyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) (Meth) acrylate monomers represented by acrylate, dimethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, γ-methacryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloxypropyltri (Meth) acryloxysilane monomers represented by toxisilane, p-styryltrimethoxysilane, etc., methacrylonitrile, cyanovinyl compounds represented by acrylonitrile, vinyl acetate, vinyl chloride, vinyl fluoride, etc. And vinyl monomers. In addition, from group B, the above monomer group can be used alone or in combination of two or more.

  Particularly suitable as the group B is n-butyl acrylate, t-butyl methacrylate or methyl methacrylate from the viewpoint of water resistance and transparency of the resulting coating film. The tackiness of the coating film changes depending on the selection of the composition of Group B. For example, by using methyl methacrylate and butyl acrylate in combination, the tackiness and adhesion of the coating film can be compatible.

  Further, from the viewpoint of making it difficult to cause uneven appearance when water droplets flow into the obtained coating film, a monomer having a functional group that undergoes a crosslinking reaction by drying and heating at the time of coating film formation is used as the group B. It is preferable because it can be expected to further reduce the water-soluble oligomer in the solution, but from this point of view, (meth) acryloxysilane monomers such as 3- (meth) acryloxypropyltrimethoxysilane are antifogging due to crosslinking. There are few side effects of a fall, and it is especially preferable. It is particularly preferable to use both such a (meth) acrylate monomer and a (meth) acryloxysilane monomer in combination.

  The blending amount of the polymerizable monomer selected from Group B is preferably 25 to 78 parts by weight, more preferably 35 to 73 parts by weight, with the total amount of polymerizable monomers being 100 parts by weight. More preferably, it is 45-68 weight part. When the amount is more than 78 parts by weight, the polarity of the polymer is insufficient and the antifogging property tends to be lowered, which is not preferable. When the amount is less than 25 parts by weight, the water resistance is lowered and dissolution of the coating film occurs, or when the attached water droplets flow, there is a tendency that the appearance unevenness is generated and the appearance is deteriorated.

  Further, it is preferable to use at least one selected from the group of nonionic water-soluble monomers as the C group from the viewpoint of water resistance of the antifogging performance. If the C group is specifically exemplified, (methoxy) polyethylene glycol Mono (meth) acrylate, (methoxy) polypropylene glycol mono (meth) acrylate, (methoxy) copoly (ethylene glycol-propylene glycol) mono (meth) acrylate, polyoxyethylene alkyl ester of acrylic acid or methacrylic acid, polyoxyethylene allyl Polymerization reactive monomers having a polyalkylene glycol structure such as glycidyl nonyl phenyl ether and polyoxyethylene allyl glycidyl nonyl phenyl ether, (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acyl Rilamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) Acrylamide, N-isobutyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-methylmaleimide, N-methylol (meth) acrylamide, dye Examples include (meth) acrylamide monomers such as acetone (meth) acrylamide and (meth) acryloylmorpholine, and terminal modified polyvinyl alcohol monomers such as terminal mercapto-modified polyvinyl alcohol.

  As the nonionic water-soluble monomer group described in Group C, at least one polymerization reactive monomer group having a polyalkylene glycol structure (hereinafter referred to as Group C1), and N-alkyl (meth). When at least one of the acrylamide monomer groups (hereinafter referred to as C2 group) is included at least, it is particularly easy to obtain a water-resistant coating film with antifogging performance, and it is easy to avoid whitening of the coating film due to moisture. Therefore, it is preferable.

  Specific examples of C1 group include (methoxy) polyethylene glycol mono (meth) acrylate, (methoxy) polypropylene glycol mono (meth) acrylate, (methoxy) copoly (ethylene glycol-propylene glycol) mono (meth) acrylate, acrylic Examples include polyoxyethylene alkyl ester of acid or methacrylic acid, polyoxyethylene allyl glycidyl nonyl phenyl ether, polyoxyethylene allyl glycidyl nonyl phenyl ether, and the like. Specific examples of the C2 group include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-isobutyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N-cyclohexyl (meth) Examples include acrylamide, N-phenyl (meth) acrylamide, N-methylmaleimide, N-methylol (meth) acrylamide, diacetone (meth) acrylamide, (meth) acryloylmorpholine, and the like. In particular, it is particularly preferable to use (methoxy) polyethylene glycol mono (meth) acrylate having 4 or more oxyethylene repeats and N, N-dimethylacrylamide.

  The preferable amount of the monomer selected from the nonionic water-soluble monomer group described in Group C is 12 to 77 parts by weight, more preferably 25 to 25 parts by weight, with the total amount of polymerizable monomers being 100 parts by weight. 50 parts by weight is good. If the amount is less than 12 parts by weight, the coating tends to be whitened by moisture. If the amount is more than 77 parts by weight, appearance irregularities occur when the attached water droplets flow, and the appearance deteriorates. There exists a tendency for a coating film to peel easily by swelling.

The manufacturing method of the anti-fogging coating material of this invention includes the process of superposing | polymerizing the mixture of the above-mentioned polymerizable monomer in an organic solvent.
The polymerization can be performed by a normal polymerization technique, and among them, it is particularly preferable to use a solution polymerization method. The reaction solvent used in the solution polymerization is not particularly limited as long as it dissolves the above-mentioned A, B, and C group monomers and can uniformly dissolve the polymer produced. Specifically, methanol, ethanol, propanol, isopropanol, 2-methyl-2-butanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono Isobutyl ether, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol Cole monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol monoethyl Ether, triethylene glycol diethyl ether, triethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether,
Methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoisobutyl ether acetate, ethylene glycol monoisopropyl ether acetate, prolene glycol monomethyl ether Acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoisobutyl ether acetate, diethyl Glycol monoisopropyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monopropyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monoisopropyl Examples include polar solvents such as ether acetate, triethylene glycol monobutyl ether acetate, acetone, methyl ethyl ketone, methyl isopropyl ketone, N-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, and triethylamine.
In the polymerization process, a mixed solvent of two or more kinds or a mixed solvent with water can be used. In the selection of the solvent, an alkylene glycol solvent, a ketone solvent or an acetic acid ester solvent which has low toxicity and low flammability and can be obtained at low cost is preferable, and an alkylene glycol monomethyl ether acetate or a ketone solvent is more preferable.

  The polymerization mechanism used in the solution polymerization method is not particularly limited. For example, radical polymerization, living radical polymerization, cation polymerization, living cation polymerization, anion polymerization, immodal polymerization, transfer polymerization, coordination anion polymerization, metathesis polymerization, etc. can be used. . Among them, radical polymerization is preferable because polymerization control is relatively easy and a polymerization initiator can be obtained at a low cost.

  The concentration of the monomers during the polymerization is not particularly limited as long as it can be sufficiently stirred. For example, the polymerization is performed with the monomer content of 10 to 70% by weight, preferably 20 to 60% by weight. Thus, a polymer can be obtained with high productivity.

The antifogging coating is a reaction solution (hereinafter referred to as a polymer solution) in which a polymer of a polymer is dissolved in a reaction solvent together with an unreacted monomer after the polymerization reaction by the above-described polymerization method, or as it is. It can be obtained by appropriately diluting. In this case, the solvent used for dilution is not particularly limited as long as it does not erode the molded article that is the coated substrate, and may be the same as the reaction solvent used.
Examples of solvents that are less eroded by plastics and are suitable for dilution include water, methanol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono Isobutyl ether, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether Diethylene glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol monoethyl ether, Examples include triethylene glycol diethyl ether, triethylene glycol monoisopropyl ether, and triethylene glycol monobutyl ether. These can be used alone or as a mixed solvent of two or more.

  The polymer solution is usually diluted with an organic solvent as described above and used as an anti-fogging coating. Depending on the purpose, the polymer solution may be dissolved or dispersed in a water-based solvent or water. Is also possible. Thus, when it is set as the anti-fogging coating material which does not contain or contains a little organic solvent, while being able to reduce VOC significantly, the load to an environment can also be reduced.

  A colloidal inorganic filler can be added to the anti-fogging paint of the present invention as required in order to further improve the appearance unevenness. When the colloidal inorganic filler is contained, the content is preferably 0 to 50 (not including 0) wt% in the total solid content of the coating material, and more preferably 25 to 40 wt%. When there are more colloidal inorganic fillers than 50 weight%, there exists a tendency for adhesiveness and anti-fogging property to fall. The colloidal inorganic filler here is an inorganic filler that is uniformly dispersed in a solvent or water, and specifically includes colloidal silica, colloidal alumina, colloidal talc, and the like. Among these, colloidal silica is preferable because it is inexpensive, has excellent dispersion stability in a solvent or water, and easily obtains a highly transparent coating film.

  Although there is no restriction | limiting in particular in the quantity of solid content contained in an anti-fog coating material, For example, the coating material with the outstanding coating-film external appearance can be obtained by adjusting solid content to 2 to 20 weight%. If necessary, wettability improvers, viscosity modifiers, pH adjusters, ultraviolet absorbers, light stabilizers, heat stabilizers, plasticizers, preservatives, antifungal agents, etc. can be optionally added, In the case where it is particularly important that the appearance unevenness due to moisture does not occur, it is preferable to avoid those having high water solubility, especially those having a whitish appearance.

  The antifogging paint as described above is applied to a molded product such as a sheet or film, and the coating film is dried to form a coating film on at least a part of the surface of the molded product to impart antifogging properties. It can be set as the anti-fogging molded article of the invention. The application method is not particularly limited, and generally a spray method, a cast method, a dip coating method, a spin coating method, or the like is used. Although there is no restriction | limiting in particular in the thickness of a coating film, The outstanding antifogging property can be exhibited by apply | coating with the thickness of 1-100 micrometers, for example. Examples of the antifogging molded article include an automotive lamp, an antifogging sheet, and an antifogging film. There is no restriction | limiting in particular in the raw material of a molded article, All can be applied to the plastic molded article generally used. For example, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyamides, polyimides, polyethers, polyesters, polyesteramides, polyesterimides, polyamideimides, polyacrylic esters , Polymethacrylic esters, polyolefins, polystyrenes, polyacrylonitriles, polyhalogenated vinyls, copolymers and mixtures thereof. Further, the antifogging molded product of the present invention in which the coating film of the coating covers at least a part of the surface of the molded product can be applied to glass, metal and the like in addition to plastic.

  The drying conditions when the anti-fogging coating is applied are appropriately selected depending on the type of solvent, the coating amount, the material of the molded product, etc., and are not particularly limited. For example, after standing at room temperature for 15 minutes, 100 ° C. A good antifogging film can be produced by drying for 20 minutes.

  Hereinafter, the present invention will be described more specifically with reference to examples. The scope of the present invention is not limited to these. In addition, the materials used in the examples and methods for measuring and evaluating various physical properties are as follows. Reagents were used unless otherwise specified.

1) Antifogging evaluation method (however, 1-1) Initial characteristics of test specimens from coating film appearance to 1-6) appearance unevenness. )
1-1) Coating film appearance The appearance and hue of the antifogging paint test piece applied to the resin plate were evaluated in four stages.
A: Colorless, transparent and glossy.
A: Colorless and transparent, but slightly inferior in gloss.
Δ: Lightly colored and poor gloss
X: Colored or opaque and cloudy.
In addition, if evaluation is more than (circle), there is no problem practically, and (double-circle) is more preferable.

1-2) Tack property test The coating film surface of the test piece was directly touched with a finger, and the evaluation was made in three stages from the touch as follows.
A: There is no stickiness and it is hard.
○: Slightly sticky, but no handling problems occur.
(Triangle | delta): It becomes stickiness clearly and the malfunction on handling arises.
In addition, if evaluation is more than (circle), there is no problem practically, and (double-circle) is more preferable.

1-3) Adhesion test The area | region of the coating-film surface 1cm x 1cm of a test piece was cut by the width of 1 mm length and width. Thereafter, a cellophane tape was applied to the surface and peeled off at once, and the number of areas where the coating film was peeled off was counted. Based on the counted number, the evaluation was made in four stages as follows.
A: Peeling number: 0 to 20
○: Number of peeling: 21 to 50
Δ: Peeling number: 51-80
X: Number of peeling: 81-100
In addition, if evaluation is more than (circle), there is no problem practically, and (double-circle) is more preferable.

1-4) Exhalation antifogging test At room temperature and immediately after cooling at −5 ° C., exhaled air was blown for 1 second at a distance of 5 cm from the test piece, and the cloudy state was observed. The appearance was evaluated in four stages.
A: Not fogged at all.
○: Cloudy for a moment and very slightly.
(Triangle | delta): A thin cloud is confirmed or a micro droplet is observed on the surface.
X: Cloudy and droplets are confirmed.
In addition, if evaluation is more than (circle), there is no problem practically, and (double-circle) is more preferable.

1-5) 80 ° C. Antifogging Test After putting water in a thermostatic bath and heating to 80 ° C., steam was applied to the test piece at a height of 5 cm from the water surface for 10 seconds. The occurrence of fogging at that time was confirmed, and the evaluation was made in four stages in the same manner as in 1-4) the breath anti-fogging test.

1-6) Appearance unevenness test After water was put into a thermostatic bath and heated to 80 ° C, steam was applied to the test piece at a height of 5 cm from the water surface until water droplets flowed down. Then, after drying for 15 minutes at 80 ° C. and observing after a water drop dripped, it was evaluated in the following four stages.
A: Almost no trace of dripping even when picked up and carefully observed with the naked eye.
○: A slight trace of drooping can be confirmed by picking it up and observing it carefully with the naked eye.
Δ: If it is picked up by the hand, it is observed after it is clearly hung with the naked eye.
X: Even after a distance of 1 m, it can be observed after it has drooped clearly with the naked eye.
In addition, if evaluation is more than (circle), there is no problem practically, and (double-circle) is more preferable.

1-7) Water resistance test The test piece was immersed in warm water at 80 ° C for 1 hour, and the obtained test piece was dried at room temperature for 1 hour, and then the same appearance evaluation, adhesion test, and breath antifogging test were performed. Went to.

1-8) Heat resistance test The sample was left in an atmosphere at 120 ° C for 240 hours. Thereafter, the coating film appearance evaluation, the breath antifogging test, the 80 ° C. antifogging test, and the appearance unevenness test were similarly evaluated and carried out.

2) Preparation method of coating film test piece Formation of the coating film test piece in the examples or comparative examples was carried out using the antifogging paint prepared below under the following method and conditions.
Application: Base material: 0.5mm thick x 200mm long x 180mm wide polycarbonate resin plate
(Product name Panlite Sheet PC-1151 manufactured by Teijin Limited)
Apparatus ... Air spray gun (Anest Iwata Campbell Co., Ltd. model number VX-510
4B (nozzle diameter 1.0 mm)), air pressure 4 kgf / cm ² (392 kP)
a)
Application amount: 3 g / m ^{2 in} terms of solid content
Drying: Equipment ... Hot air dryer (Model number SPH201 manufactured by Espec Corporation)
Conditions: 80 ° C, 15 minutes

3) Production of anti-fogging coating The production of the anti-fogging coating in Examples or Comparative Examples was carried out by the following methods and conditions.
3-1) Preparation of polymer solution for anti-fogging coating (Compositions A1 to A6, B1 to B5: see Tables 1 and 2)
(Explanation of each material of polymer solution for anti-fogging paint and abbreviations in [Table 1 to Table 2])
JS-2: (an aqueous solution of sodium alkenyl sulfonate 38%, Sanyo Kasei Kogyo Co., Ltd., abbreviation for trade name Eleminol JS-2) was used as is (stock solution). In Tables 1 and 2, the parts by weight of JS-2 with the total charge being 100 are the amount of the stock solution, and the parts by weight of JS-2 with the total monomer amount being 100 are the amounts converted to solids. It is.
SMAS: (Asahi Kasei Finechem Co., Ltd., product name of sodium methallyl sulfonate) is used as it is.
SAS: (Asyl Kasei Finechem Co., Ltd. sodium allyl sulfonate product name) is used as is.
M-90G: (Shin Nakamura Chemical Co., Ltd. methoxypolyethylene glycol monomethacrylate trade name, average value of PEG chain length = 9) was used as it was.
KBM503: (trade name of γ-methacryloxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.) is used as it is.
BA: butyl acrylate (butyl acrylate), MMA: methyl methacrylate (methyl methacrylate), DMAA: N, N-dimethylacrylamide, AIBN: azobisisobutyronitrile (polymerization initiator), PGMMEA: propylene glycol monomethyl ether acetate , MEK: methyl ethyl ketone, n-propyl acetate, and acetone are used as they are.

Preparation of polymer solution for anti-fogging coating (Composition A1: See Table 1)
A 500 ml separable flask was equipped with a Dimroth, a nitrogen inlet tube, and a stirring device, and 10.9 g of sodium alkenyl sulfonate (trade name Eleminol JS-2 (solid content 38%) manufactured by Sanyo Chemical Industries, Ltd.), SMAS (Asahi Kasei Finechem) 0.9 g of sodium methallyl sulfonate (trade name) manufactured by Co., Ltd. was blended. Separately, in a 300 ml beaker, 48.3 g of butyl acrylate, 28.1 g of methyl methacrylate, methoxypolyethylene glycol monomethacrylate (trade name M-90G manufactured by Shin-Nakamura Chemical Co., Ltd. (average value of polyethylene glycol chain length = 9)) ) 36.0 g, N, N-dimethylacrylamide 41.1 g, γ-methacryloxypropyltrimethoxysilane (trade name KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) 6.6 g, azobisisobutyronitrile 0.99 g , 242.6 g of propylene glycol monomethyl ether acetate was blended, dissolved uniformly, charged into the flask, and heated to 60 ° C. Polymerization was performed at 60 ° C. for 3 hours, and further aging was performed at 80 ° C. for 2 hours to prepare a polymer solution. The obtained polymer solution had a solid content of 40% and a polymerization rate of 99%.
(Composition A2-A6, B1-B5)
A polymer solution having a solid content of 60% by weight and a polymerization rate of 99% was prepared in the same manner as in the preparation of A1 except that the compositions described in Tables 1 and 2 were followed.

3-2) Preparation of anti-fogging paint (Examples 1-6, Comparative Examples 1-5)
(Explanation and supplement of each material of anti-fog paint and its abbreviations in [Table 3 to Table 4])
As the polymer solution, one having a solid content of 40% by weight (A1) or 60% by weight (A2 to A6, B1 to B5) obtained in 3-1) is used. A 2% AcOH: 2% acetic acid aqueous solution was prepared by dissolving 98% acetic anhydride (special grade reagent) in pure water and adjusting the content to 2% by weight. PGMME: Propylene glycol monomethyl ether used the reagent as it was. As colloidal silica, NPC-ST30: (Nissan Chemical Industry Co., Ltd. colloidal silica trade name: solid content of 30% by weight) was used as it was.
(Example 1: see Table 3)
Among the polymer solution prepared above, 9.0 g of A1 (solid content 40%), 8.0 g of colloidal silica (NPC-ST30 manufactured by Nissan Chemical Industries, Ltd., solid content 30%), 2% aqueous acetic acid solution 5. 0 g and 78.0 g of propylene glycol monomethyl ether were blended and stirred at room temperature until uniform to obtain an antifogging paint. The resulting antifogging paint had a solid content of 6%. The obtained anti-fogging coating was used as it was, and spray-coated according to the above-described 2) method for preparing a coating film test piece and used for evaluation. The evaluation results are also shown in Table 3.
(Examples 2-6, Comparative Examples 1-5)
A solvent-based antifogging paint was obtained and evaluated using the same method as in Example 1 except that the compositions shown in Tables 3 and 4 were used. The evaluation results are also shown in Tables 3 and 4.

As can be seen from Tables 3 to 4 above, the antifogging coating of the present invention is very inconspicuous in appearance unevenness that occurs when water droplets adhering to the coating film flow, and has heat resistance, appearance, applicability, It was excellent in all of haze and water resistance.
On the other hand, Comparative Examples 1 and 2 were poor in antifogging properties and heat resistance, 3 was inferior in appearance unevenness, 4 was inferior in antifogging properties, water resistance, and appearance unevenness, and 5 was extremely inferior in water resistance and appearance unevenness. .

  Comparative Examples 1 and 3 do not use the A2 group. Further, Comparative Examples 2 and 4 do not use the A1 group. If the A1 group and the A2 group are not used in combination, the initial antifogging property, the antifogging property after the heat test, and the appearance unevenness due to moisture cannot be compatible. Moreover, the comparative example 5 does not use the B group. It shows that the water resistance and the appearance unevenness are extremely inferior unless the group B is used.

Claims (11)

At least one selected from a polymerizable monomer group (hereinafter referred to as A1 group) which is a metal salt of a sulfonic acid having a long-chain alkyl group having 8 or more carbon atoms;
At least one selected from a polymerizable monomer group (hereinafter referred to as group A2) which is an aryl group or a metal salt of a sulfonic acid having an alkyl group having less than 8 carbon atoms;
A polymerizable monomer that is copolymerizable with the groups A1 and A2 and that contains at least one monomer group (hereinafter referred to as group B) that is slightly soluble, hardly soluble or insoluble in water, is polymerized. An anti-fogging paint characterized by containing a polymer.   In the polymer, the total amount of polymerizable monomers is 100 parts by weight, and the total amount of polymerizable monomers selected from the groups A1 and A2 is 2 to 10 parts by weight. The anti-fogging coating material according to claim 1, which is obtained by polymerizing a polymerizable monomer having a weight of 25 to 78 parts by weight. The A1 group is represented by the following chemical formula (1)

(In the chemical formula (1), R ₁ is a C _{8 to} C ₁₈ alkyl group, and ⁺ M is an alkali metal ion.)
Including a monomer represented by
The A2 group is represented by the following chemical formula (2)

And a monomer represented by the following chemical formula (3)

(In the chemical formula (2) and chemical formula (3), R ₂ and R ₄ are each independently H or CH ₃ groups. R ₃ and R ₅ are each independently an alkylene group having 1 to 7 carbon atoms, or (This is a group in which one hydrogen atom has been removed from the carbon atom of the aryl group, and ⁺ M is an alkali metal ion.)
The antifogging paint according to claim 1 or 2 comprising a monomer represented by   The antifogging paint according to any one of claims 1 to 3, wherein the polymerizable monomer selected from the A1 group and the A2 group is 10/90 to 90/10 in molar ratio.   The polymer further comprises at least one selected from a nonionic water-soluble monomer group (hereinafter referred to as group C), 12 to 77 weights, with the total amount of polymerizable monomers being 100 parts by weight. The anti-fogging coating material according to any one of claims 1 to 4, which is obtained by polymerizing a polymerizable monomer contained in part.   The anti-fogging paint according to claim 5, wherein the group C includes at least one of a polymerization-reactive monomer group having a polyalkylene glycol structure and at least one of an N-alkyl (meth) acrylamide monomer group. .   The antifogging paint according to any one of claims 1 to 6, further comprising a colloidal inorganic filler, wherein the colloidal inorganic filler is contained in an amount of 0 to 50% (not including 0) in the total solid content.   An antifogging molded article, wherein the film of the antifogging paint according to any one of claims 1 to 7 covers at least a part of the surface of the molded article.   The antifogging molded article according to claim 8, which is an automobile lamp.   The antifogging molded article according to claim 8, which is an antifogging sheet or an antifogging film. At least one selected from a polymerizable monomer group (hereinafter referred to as A1 group) which is a metal salt of a sulfonic acid having a long-chain alkyl group having 8 or more carbon atoms;
At least one selected from a polymerizable monomer group (hereinafter referred to as group A2) which is an aryl group or a metal salt of a sulfonic acid having an alkyl group having less than 8 carbon atoms;
Having a step of polymerizing a polymerizable monomer mixture containing at least one monomer group that is copolymerizable with the groups A1 and A2 and is slightly soluble, hardly soluble or insoluble in water in an organic solvent. A method for producing an anti-fogging paint characterized.