WO2017033532A1

WO2017033532A1 - Anti-fogging coating, anti-fogging coated article, and method for producing anti-fogging coated article

Info

Publication number: WO2017033532A1
Application number: PCT/JP2016/067490
Authority: WO
Inventors: 井上　雅史; 敏裕平野; 教和藤浦; 宏紀深澤; 濱口　滋生
Original assignee: セントラル硝子株式会社
Priority date: 2015-08-21
Filing date: 2016-06-13
Publication date: 2017-03-02

Abstract

[Problem] The present invention addresses the problem of providing an anti-fogging coating and an anti-fogging coated article each having both hydrophilicity and scratch resistance. [Solution] An anti-fogging coating containing a urethane resin having an oxyethylene group, an oxypropylene group, and an acyl group, and characterized in that the anti-fogging coating contains a fluorine-containing surfactant, the surface layer thickness of the fluorine-containing surfactant in the anti-fogging coating is 0.001-2% of the thickness of the coating, and the ratio of the number of fluorine atoms to the number of all atoms which are observed in the surface of the anti-fogging coating through elementary analysis of the anti-fogging coating is 5-30%.

Description

Anti-fogging film, anti-fogging film-forming article and method for producing anti-fogging film-forming article

The present invention relates to an antifogging film, an antifogging film forming article, and a method for producing an antifogging film forming article.

In order to ensure the visibility of transparent base materials such as mirrors for bathrooms and vanities, automobile window glass and camera lenses, it is strongly required to add anti-fogging function to the surfaces of these base materials. ing.

Cloudiness that occurs on the surface of a substrate such as a mirror or glass is caused by a dew condensation phenomenon in which countless minute water droplets are formed on the surface of the substrate. In order to prevent this fogging, hydrophilic coatings that have innumerable minute water droplets formed on the surface of the substrate as a uniform water film, water-absorbing coatings that incorporate water droplets into the coating, and the like have been formed on the substrate. .

In mirrors for bathrooms and vanities and window glass of automobiles, they are frequently wiped for cleaning, so in addition to good anti-fogging properties, in terms of film hardness such as scratch resistance and pencil hardness There is also a need to be excellent.

In Patent Document 1, as a method of forming a urethane resin-based antifogging film having excellent antifogging properties and abrasion resistance, a coating agent A containing an isocyanate component, polyethylene glycol, and copolymerization of oxyethylene / oxypropylene An antifogging property obtained by coating a base material with a two-component curable antifogging film-forming coating agent comprising a polyol component having a polyol and a short-chain polyol, and a coating agent B containing a surfactant having an isocyanate-reactive group. A method of forming a coating is disclosed.

The antifogging film of Patent Document 1 exhibits antifogging properties by two functions of water absorption by polyethylene glycol or oxyethylene / oxypropylene copolymer polyol and hydrophilicity by a surfactant.

JP 2004-244612 (Patent No. 4535707)

However, the antifogging film described in Patent Document 1 needs to contain a large amount of a surfactant in the film in order to improve the hydrophilicity, and as a result, the scratch resistance may decrease, It was difficult to achieve both hydrophilicity and scratch resistance (see Comparative Examples 6 and 7 described later). Therefore, there has been a strong demand for an anti-fogging film that achieves both hydrophilicity and scratch resistance.

Therefore, an object of the present invention is to provide an antifogging film and an antifogging film-formed article having both hydrophilicity and scratch resistance.

As a result of various studies in view of the above problems, the present inventors have found that a fluorine-containing surfactant is added to the antifogging coating in the antifogging coating containing a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group. The fluorine-containing surfactant is localized on the surface of the anti-fogging coating, and all the atoms observed on the surface of the anti-fogging coating are analyzed by elemental analysis of the anti-fogging coating. It has been found that by setting the ratio of the number of fluorine atoms to the number to a specific value, an antifogging film having both hydrophilicity and scratch resistance can be formed, and the present invention has been achieved.

That is, the present invention includes the following inventions.
[Invention 1]
An anti-fogging film comprising a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group,
The antifogging film contains a fluorine-containing surfactant,
The surface layer thickness of the fluorine-containing surfactant in the antifogging film is 0.001 to 2% with respect to the film thickness of the film,
An antifogging film, wherein the ratio of the number of fluorine atoms to the total number of atoms observed on the surface of the antifogging film is 5 to 30% by elemental analysis of the antifogging film.
[Invention 2]
2. The antifogging film according to invention 1, wherein the fluorine-containing surfactant is a fluorine-containing surfactant represented by the following general formula [1].

(In the formula [1], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y is combined with X to form a single bond. , N is a natural number from 2 to 22.)
[Invention 3]
An antifogging film-forming article comprising a base material and the antifogging film according to the invention 1 or 2 formed on the base material.
[Invention 4]
The antifogging film-formed article according to invention 3, wherein the film thickness of the antifogging film is 5 to 40 μm.
[Invention 5]
The antifogging film-formed article according to invention 4, wherein the substrate is glass or a mirror.
[Invention 6]
A method for producing an antifogging film-forming article comprising a base material and the antifogging film according to the invention 1 formed on the base material,
An isocyanate compound having an isocyanate group,
An oxyethylene / oxypropylene copolymer polyol having a molar ratio of oxyethylene / oxypropylene of 60:40 to 90:10 and a number average molecular weight of 2000 to 15000,
An acrylic polyol having a number average molecular weight of 5000 to 25000,
A fluorine-containing surfactant represented by the following general formula [1],
Including
The solid content of the isocyanate compound is 50 to 75 mass% with respect to 100 mass% of the total solid content of the urethane-forming component,
The acrylic polyol has a solid content of 2 to 50% by mass with respect to 100% by mass of the total solid content of the polyol component,
A coating agent for forming an antifogging film, wherein the fluorine-containing surfactant is 0.1 to 5.0% by mass with respect to the total solid content of the urethane-forming component, and a substrate. Preparation, preparation process,
Applying the coating agent to the substrate; and
A method for producing an antifogging film-formed article, comprising a curing step of curing the coating agent applied to the substrate.

(In the formula [1], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y is combined with X to form a single bond. , N is a natural number from 2 to 22.)

An antifogging film having an oxyethylene group, an oxypropylene group, and an acyl group contains a fluorine-containing surfactant, and the fluorine-containing surfactant is localized on the surface layer of the antifogging film. By setting the ratio of the number of fluorine atoms observed on the surface of the antifogging film by analysis to a specific value, an antifogging film having both hydrophilicity and scratch resistance can be formed.

Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be applied with appropriate modifications without departing from the scope of the present invention.

<Anti-fogging film>
The antifogging film of the present invention is an antifogging film containing a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group, and the antifogging film contains a fluorine-containing surfactant, and The surface layer thickness of the fluorine-containing surfactant in the cloudy film is 0.001 to 2% with respect to the film thickness, and is observed on the surface of the cloudy film by elemental analysis of the cloudy film. The antifogging film is characterized in that the ratio of the number of fluorine atoms to the total number of atoms is 5 to 30%.

<Urethane resin>
The urethane resin contained in the antifogging film of the present invention is a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group. The urethane resin can be formed, for example, by polycondensation of an isocyanate compound and a polyol component such as an oxyethylene / oxypropylene copolymer polyol or an acrylic polyol.

<Isocyanate compound>
The above isocyanate compound is used as a raw material for urethane resin, and is a trifunctional polyisocyanate having diisocyanate, hexamethylene diisocyanate as a starting material and / or an isocyanate structure, diisophorone diisocyanate, diphenylmethane diisocyanate, bis (methyl (Cyclohexyl) diisocyanate, toluene diisocyanate and the like. Among the isocyanate compounds, an isocyanate having a biuret structure using hexamethylene diisocyanate as a starting material is preferable from the viewpoint of weather resistance and chemical resistance.

The isocyanate compound is usually 50 to 75% by mass, more preferably 55 to 75% by mass with respect to 100% by mass of the total solid content of the urethane-forming component (referred to in the present invention as an isocyanate compound and a polyol component). More preferably, it is 55 to 65% by mass. When the isocyanate compound is more than 75% by mass, the polyol component is insufficient and the crosslinked structure is not sufficiently formed, so that the hardness of the film may be insufficient. Also, when the isocyanate compound is less than 50% by mass, the hardness of the film may be insufficient.

The total number of isocyanate groups present in the isocyanate compound is usually 1.0 to 15 times, more preferably 1.1 times the total number of hydroxyl groups present in the polyol constituting the urethane resin. It is preferable to adjust the amount to be 10 times or less, more preferably 1.1 times or more and 3 times or less. When the amount is less than 1.0 times, the curability of the coating agent may deteriorate.

<Polyol component>
As raw materials for the urethane resin, polyol components such as oxyethylene / oxypropylene copolymer polyol and acrylic polyol can be used.
<Oxyethylene / oxypropylene copolymer polyol>
The oxyethylene / oxypropylene copolymer polyol (hereinafter also referred to as EO / PO copolymer polyol) is available from the city, and uses a phosphazene compound, Lewis acid compound or alkali metal compound catalyst as an initiator. It is a polyether polyol obtained by ring-opening polymerization of ethylene oxide and propylene oxide and then block addition or random addition.

The oxyethylene / oxypropylene copolymer polyol is a component that mainly imparts a water-absorbing function to the coating and exhibits antifogging properties. This polyol has an oxyethylene group (—CH ₂ CH ₂ —O—) and an oxypropylene group (—CH ₂ CH ₂ CH ₂ —O—, —CH (CH ₃ ) CH ₂ —O—). Since the oxyethylene group is excellent in the function of absorbing water as bound water, it is advantageous for forming an antifogging film exhibiting reversible absorption and dehydration with a high dehydration rate during dehydration, and the ambient temperature is 5 ° C. or lower. Even in such a low-temperature environment such as winter, a film formed using a copolymer polyol having an oxyethylene chain tends to exhibit antifogging properties.

The molar ratio of oxyethylene groups to oxypropylene groups (hereinafter also referred to as EO / PO ratio) of the oxyethylene / oxypropylene copolymer polyol is usually 60:40 to 90:10, and 70:30 to 90. : 10 is more preferable, and 75:25 to 85:15 is more preferable. When the proportion of oxyethylene exceeds 90%, the action of hydrophobic oxypropylene chains is reduced, and it is difficult to induce hydrophilic oxyethylene chains and fluorine-containing surfactants near the membrane surface. If it is less than 45%, the hydrophobic oxypropylene chain increases, and it is considered that sufficient hydrophilicity is hardly obtained even if a hydrophilic agent is added.

The number average molecular weight of the oxyethylene / oxypropylene copolymer polyol is usually 500 to 20000, and when the number average molecular weight is less than 500, the ability to absorb water as bound water is low, and the number average molecular weight exceeds 20000 May cause problems such as poor curing of the coating agent and a decrease in film strength. Considering the water absorption, hydrophilicity, film strength, etc. of the coating, it is preferably 2000 to 15000, more preferably 3000 to 12000, and more preferably 3000 to 6000.

The solid content of the oxyethylene / oxypropylene copolymer polyol is usually 25 to 75% by mass, preferably 30 to 70% by mass, more preferably 40 to 40% by mass with respect to 100% by mass of the total solid content of the polyol component. 60% by mass.

<Acrylic polyol>
The acrylic polyol is used as a raw material for urethane resin, and is a copolymer of a hydroxyalkyl (meth) acrylate and a copolymerizable monomer such as alkyl (meth) acrylate, and has durability such as wear resistance of the film. It is a component used for improving the surface friction coefficient and reducing the surface friction coefficient, that is, for exhibiting slip properties on the film surface.

Acrylic polyols are commercially available and are hydroxyl group-containing monomers such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, N-methylolacrylamide, and the like. Styrene, methyl methacrylate, ethyl methacrylate, methacrylate-n-butyl, isobutyl methacrylate, tertiary butyl methacrylate, acrylotolyl, methacrylonitrile, methyl acrylate, ethyl acrylate, acrylic acid-n- Those obtained by copolymerization with butyl, isobutyl acrylate, tertiary butyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, or the like can be used.

Further, amino group-containing monomers such as 2-dimethylaminoethyl methacrylate and tert-butylaminoethyl methacrylate, glycidyl group-containing monomers such as glycidyl acrylate and glycidyl methacrylate, amino group-containing monomers such as acrylamide and methacrylamide, acrylic acid , Methacrylic acid, maleic anhydride, crotonic acid, fumaric acid, itaconic acid and other acid group-containing monomers, or fumaric acid esters, itaconic acid esters and the like may be copolymerized with the hydroxyl group-containing monomers.

The number average molecular weight of the acrylic polyol is usually 5000 to 25000, more preferably 10,000 to 25000, and further preferably 15000 to 20000. When the number average molecular weight of the acrylic polyol is smaller than 5000, the film becomes too dense and may become brittle. On the other hand, if it is larger than 25000, the volume of the acrylic polyol in the film increases, and the hydrophilicity tends to be lowered.

The solid content of the acrylic polyol is usually 2 to 50% by mass, more preferably 5 to 40% by mass, and further preferably 15 to 35% by mass with respect to 100% by mass of the total solid content of the polyol component. When the solid content of the acrylic polyol is larger than 50% by mass, the antifogging property and hydrophilicity are liable to be lowered, and when it is smaller than 2% by mass, it is difficult to obtain a sufficient hardness of the coating film.

<Short chain polyol>
The urethane resin preferably uses a short-chain polyol (in the present invention, a polyol having a number average molecular weight of 60 to 200 is called a short-chain polyol) as a raw material. The short chain polyol is a component for improving the hardness of the antifogging coating. The short chain polyol preferably has 2 or 3 hydroxyl groups. When the hydroxyl group is 1, the short-chain polyol does not act as a crosslinking component and does not serve as a skeleton component of the film, so that the film may not have sufficient hardness. In the case of 4 or more, the reactivity is too high and the coating agent may become unstable.

Short chain polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, Alkyl polyols such as glycerin, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol, 1,2,6-hexanetriol, 2,2′-thiodiethanol, alkanolamines such as diethanolamine and triethanolamine They can be used alone or as a mixture or as a mixture A copolymer having a number average molecular weight of 60 to 200 can be used. Among the above short-chain polyols, ethylene glycol and triethylene glycol are preferable from the viewpoint of the hardness of the antifogging coating, and 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, A short-chain polyol having a secondary or tertiary hydroxyl group having a lower activity than the primary hydroxyl group such as 1,3-butanediol is preferred from the viewpoint of the stability of the coating solution (prolonging the pot life).

Usually, when a component for improving the durability of the coating such as a short-chain polyol is introduced, the anti-fogging property of the anti-fogging coating is lowered. However, an antifogging film having excellent antifogging properties, abrasion resistance and the like can be obtained by containing an appropriate amount of a surfactant and an appropriate amount of a copolymer polyol. Specifically, the solid content of the short-chain polyol is usually 6 to 40% by mass, preferably 6 to 30% by mass, and more preferably 6 to 22% by mass with respect to 100% by mass of the total solid content of the polyol component. %.

<Polyethylene glycol>
In order to improve the water absorption of the film, polyethylene glycol (PEG) may be used as the polyol component instead of the short-chain polyol.

<Fluorine-containing surfactant>
The antifogging film of the present invention contains a fluorine-containing surfactant. Examples of the fluorine-containing surfactant include perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyltrimethylammonium salt, perfluoroalkylaminosulfonate, perfluoro Alkyl group-containing oligomer, perfluoroalkenyloxybenzene sulfonate, perfluoroalkenyloxybenzenesulfonyl sarcosine sodium, perfluoroalkenyl polyoxyethylene ether, perfluoroalkenyloxybenzenesulfone alkylammonium iodide, perfluoroalkenyloxybenzamide alkylammonium iodide Perfluoroalkenyloxyaralkylbetaine, perfluoroalkenyloxya Rukiruhosuhon acid or the like can be used. It is presumed that the fluorine-containing surfactant is a component that imparts hydrophilicity to the coating to develop antifogging properties.

As a component for imparting hydrophilicity to a film containing a urethane resin having an oxyethylene group, an oxypropylene group, or an acyl group to develop antifogging properties, conventionally, as in Patent Document 1, an ionic interface that does not contain fluorine. In the system of the present invention, when such a surfactant is used, localization of the surfactant on the surface layer of the coating is insufficient, resulting in hydrophilicity and scratch resistance. It was not excellent (refer to Comparative Examples 6 and 7 described later). Thus, by using a fluorine-containing surfactant and localizing the fluorine-containing surfactant on the surface layer of the coating, it was possible to achieve both hydrophilicity and scratch resistance (see Examples described later).

Further, as the fluorine-containing surfactant, it is preferable to use a fluorine-containing surfactant represented by the following general formulas [1] and [2]. These fluorine-containing surfactants do not have isocyanate-reactive groups such as hydroxyl groups, mercapto groups, and amino groups. Among the above-mentioned fluorine-containing surfactants, fluorine-containing surfactants represented by the following general formula [1] are preferable from the viewpoint of high hydrophilicity and film hardness. In the fluorine-containing surfactant represented by the following general formula [1], in the formula [1], X and Y are preferably single bonds, and n is preferably a natural number of 8 to 16. More preferably, the natural number is 9 to 13.

(In the formula [1], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y is combined with X to form a single bond. , N is a natural number from 2 to 20.)

(In the formula [2], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y also becomes a single bond with X. , N is a natural number from 2 to 15.)

The content of the fluorine-containing surfactant is preferably 0.1 to 5.0% by mass, and preferably 0.5 to 2.0% by mass, based on the total solid content of the urethane-forming component. Is more preferable. When the content of the fluorine-containing surfactant is increased, the quality of the obtained film is affected by the fluorine-containing surfactant, and the appearance and film strength may be hindered. On the other hand, when the content of the fluorine-containing surfactant is small, the hydrophilicity of the coating surface is not sufficiently obtained. Further, the fluorine atom in the fluorine-containing surfactant preferably accounts for 10 to 50% by mass, more preferably 20 to 40% by mass with respect to the total amount of the fluorine-containing surfactant. The amount of fluorine atoms in the fluorine-containing surfactant is preferably 0.1 to 1.0% by mass, preferably 0.1 to 0.7% by mass, based on the total solid content of the urethane-forming component. % Is more preferable.

The surface layer thickness of the fluorine-containing surfactant in the antifogging coating of the present invention is 0.001 to 2% with respect to the thickness of the coating. If it exceeds 2%, it is inappropriate in that the appearance of the coating is clouded or the pencil hardness is lowered, and if it is less than 0.001%, it is inappropriate in that the hydrophilicity is lowered. In the present invention, the surface layer thickness of the surfactant refers to the fluorine contained in the surfactant by performing elemental analysis while etching in the depth direction from the coating surface by elemental analysis using X-ray photoelectron spectroscopy (XPS). It means the depth from the coating surface where the sulfur concentration is below the detection limit. The thinner the surface layer thickness of the fluorine-containing surfactant, the more the fluorine-containing surfactant is localized on the surface of the coating, which is considered preferable from the viewpoint of imparting hydrophilicity to the coating and the hardness of the coating. If the surface layer thickness of the fluorine-containing surfactant is reduced, the hardness of the coating is easily increased. The surface layer thickness of the fluorine-containing surfactant is more preferably 0.01 to 1% with respect to the film thickness, and further preferably 0.01 to 0.5% with respect to the film thickness. .

In the antifogging coating of the present invention, the ratio of the number of fluorine atoms to the total number of atoms observed on the surface of the coating by elemental analysis is 5 to 30%. In the present invention, the ratio of the number of fluorine atoms is determined by performing an elemental analysis on the surface of the film using X-ray photoelectron spectroscopy (XPS), and determining the area of peaks derived from existing fluorine, sulfur, carbon, oxygen, and nitrogen. This area was multiplied by a coefficient depending on the detection sensitivity of each element, and converted into the number of atoms to calculate the atomic composition percentage. When the ratio of the number of fluorine atoms is less than 5%, the fluorine-containing surfactant is not sufficiently present on the surface of the coating, and the hydrophilicity becomes insufficient. Is not preferred because it becomes cloudy. The ratio of the number of fluorine atoms is more preferably 10 to 30%, still more preferably 17 to 30%.

<Method for producing antifogging film-formed article>
A method for producing the antifogging film-formed article of the present invention will be described. A method for producing an antifogging film-formed article of the present invention is a method for producing an antifogging film-forming article having a base material and the above-described antifogging film formed on the base material. ,
An isocyanate compound having an isocyanate group,
An oxyethylene / oxypropylene copolymer polyol having a molar ratio of oxyethylene / oxypropylene of 60:40 to 90:10 and a number average molecular weight of 2000 to 15000,
An acrylic polyol having a number average molecular weight of 5000 to 25000,
A fluorine-containing surfactant represented by the following general formula [1],
Including
The solid content of the isocyanate compound is 50 to 75 mass% with respect to 100 mass% of the total solid content of the urethane-forming component,
The acrylic polyol has a solid content of 2 to 50% by mass with respect to 100% by mass of the total solid content of the polyol component,
A coating agent for forming an antifogging film, wherein the fluorine-containing surfactant is 0.1 to 5.0% by mass with respect to the total solid content of the urethane-forming component, and a substrate. Preparation, preparation process,
Applying the coating agent to the substrate; and
It is a manufacturing method of the antifogging film formation article | item characterized by having the hardening process which hardens this coating agent apply | coated to this base material.

In the preparation step, a base material and a coating agent for forming an antifogging film are prepared. As a base material, glass is typically used. The glass is a plate glass usually used for automobiles, architectural and industrial glasses, and is a plate glass by a float method, a duplex method, a roll-out method, etc., and the manufacturing method is not particularly limited.

As glass types, it can be used for various colored glasses such as clear, green and bronze, various functional glasses such as UV, IR cut glass and electromagnetic shielding glass, netted glass, low expansion glass, zero expansion glass and fireproof glass. Various glass products such as glass, tempered glass or similar glass, laminated glass, multilayer glass, mirrors produced by the silvering method or vacuum film forming method, flat plates, bent plates and the like can be used.

The plate thickness is not particularly limited, but is preferably 1.0 mm or more and 10 mm or less, and particularly preferably 1.0 mm or more and 5.0 mm or less. The antifogging film may be formed on the substrate surface only on one side of the substrate or on both sides depending on the application. Further, the antifogging film may be formed on the entire surface or a part of the substrate surface.

In the case of forming a film by applying a coating agent to a glass substrate, in order to improve the adhesion between the substrate and the film, a liquid having a silane coupling agent is applied before application of the antifogging film forming coating agent. Furthermore, it is preferable to apply to the surface of the glass substrate. Suitable silane coupling agents include amino silanes, mercapto silanes and epoxy silanes. Preferred are γ-glycidoxypropyltrimethoxy, γ-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyltriethoxysilane, and the like.

In addition to the glass, a resin film such as polyethylene terephthalate, a resin such as polycarbonate, or the like can be used as a base material. The antifogging film may be formed on the surface of the resin transparent substrate to form an antifogging film-formed article, and the article may be attached to a glass substrate.

The coating agent for forming an antifogging film is obtained by mixing a chemical solution containing an isocyanate compound having an isocyanate group and a chemical solution containing a polyol component and a fluorine-containing surfactant. The isocyanate group reacts with the hydroxyl group of the polyol component, a urethane bond is formed, and a urethane resin starts to be formed. In addition, the kind and ratio of the urethane forming component (polyol component and isocyanate compound) and the fluorine-containing surfactant in the coating agent for forming the antifogging film are as described above for the urethane resin contained in the antifogging film. It is the same as the kind and ratio of the raw material and the fluorine-containing surfactant contained in the antifogging film.

Next, an application step of applying an antifogging film-forming coating agent to the substrate is performed. As the coating means, known means such as dip coating, flow coating, spin coating, roll coating, spray coating, screen printing, flexographic printing and the like can be employed. After the application, a curing process for curing the coating agent for forming an antifogging film is usually performed by standing at room temperature or by heat treatment at 170 ° C. or lower to form an antifogging film on the substrate. If the temperature of the heat treatment exceeds 170 ° C., the urethane resin may be carbonized to cause problems such as a decrease in film strength. In order to accelerate the curing reaction of the coating agent, it is preferable to perform a heat treatment at 80 ° C. to 170 ° C.

The film thickness of the antifogging film is desirably about 5 to 40 μm after the curing reaction of the coating agent for forming the antifogging film, more preferably 5 to 20 μm, and further preferably 5 to 15 μm. If it is less than 5 μm, the durability tends to be inferior. If it exceeds 40 μm, defects such as optical distortion may occur in appearance quality.

The use of the antifogging film-formed article of the present invention is as follows: mirrors for bathrooms, bathroom vanities, etc. for buildings, window glasses, etc., windows, mirrors, etc. for vehicles, ships, aircrafts, etc. In particular, room mirrors, door mirrors, etc., other lenses such as glasses and cameras, goggles, helmet shields, refrigerated showcases, frozen showcases, testing machines, precision instrument cases, etc. openings and viewing windows, road reflections Display of mobile communication bodies such as mirrors and mobile phones.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to such examples.

In this example and comparative example, a coating agent for forming an antifogging film for forming an antifogging film was prepared, applied on a substrate and dried to produce an antifogging film-formed article. The method for preparing the coating agent and the method for producing the antifogging film-formed article are as described below. Moreover, quality evaluation was performed by the method shown below about the obtained antifogging film formation article.

[Film thickness]: The film thickness was measured by cutting the surface of the film with a cutter, etc., and measuring the level difference between the film surface and the substrate surface with a surface roughness meter (Surfcoder ET-4000A manufactured by Kosaka Laboratory). The five-point average value was taken as the film thickness.

[Surface thickness of surfactant]: Elemental analysis was performed while etching in the depth direction from the coating surface using an X-ray photoelectron spectrometer (PHI バック 5000 VersaProbeII manufactured by ULVAC-PHI Co., Ltd.). The depth from the surface of the coating where the concentration of contained fluorine or sulfur was below the detection limit was defined as the surface layer thickness of the surfactant. In Table 1, the surface layer thickness of the surfactant is expressed as a percentage of the film thickness. The measurement was performed by irradiating the surface of the antifogging film-formed article with a monochromatic AIKα ray 50W 15KV to a photoelectron take-off angle of 45 ° and etching with an argon-gas cluster ion beam. The etching rate was about 4 nm / min for the anti-fogging coating.

[Fluorine atom ratio, sulfur atom ratio on the coating surface]: Elemental analysis on the coating surface was performed using an X-ray photoelectron spectrometer (PHI 5000 VersaProbeII manufactured by ULVAC-PHI Co., Ltd.), and fluorine, sulfur, carbon, oxygen present The area of the peak derived from nitrogen was determined, and the area was multiplied by a coefficient depending on the detection sensitivity of each element, and converted to the number of atoms to calculate the atomic composition percentage. The measurement was performed by irradiating the surface of the antifogging film-formed article with a monochrome AIKα ray 50 W 15 KV at a 200 μm square, and a photoelectron take-off angle of 45 °.

[Appearance evaluation]: Appearance, permeability, and presence / absence of cracks of the antifogging film-formed article were visually evaluated, and those having no problem were evaluated as acceptable (◯) and those having problems as unacceptable (×).

[Anti-fogging evaluation]: In a room at room temperature (temperature 24 ° C., humidity 45%), exhale with an interval of 20 mm between the coating and the examiner's mouth against the coating surface of the anti-fogging coating-formed article. . Observing the cloudiness while illuminating the reflected light with a fluorescent lamp, the mark that could be recognized as a map was marked as ◯, and the mark that was cloudy and could not be recognized as a mark.

[Hydrophilicity evaluation]: 2 μL of ion-exchanged water was dropped on the coating surface of the antifogging film-formed article, and the angle formed by the droplet and the coating surface 10 seconds after landing was measured using a contact angle meter (CA-X200, Kyowa). It was measured at room temperature (about 25 ° C.) using Interface Science Co., Ltd. The smaller the contact angle, the better the hydrophilicity. When the contact angle is 30 ° or less, the water droplets adhering to the surface of the article are likely to spread out, and the irregular reflection of light due to the water droplets is suppressed, and it becomes difficult to cloud.

[Pencil hardness]: According to “JIS K 5600 paint general test method”, the surface of the film was scratched twice with a pencil loaded with 750 g, and the hardness of the pencil without film tearing was measured twice. Hardness. Those having a pencil hardness of 2H or more were accepted.

[Scratch resistance]: As an evaluation of the scratch resistance, the number of times until scratches were generated was measured while sliding the surface of the base material with a strength of about 300 g / cm <2> with white nell (count: # 100). The case where scratches occurred at less than 200 round trips was marked with ×, the case where scratches occurred between 200 round trips and 1000 round trips, and the case where scratches did not occur after 1000 round trips were marked with ◎.

[Steel Wool Resistance (SW Resistance)]: As an evaluation of SW resistance, the number of scratches after 10 reciprocating slides on the substrate surface at a strength of about 325 g / cm 2 with SW (count: # 0000). Was measured. After the test, those with less than 10 scratches were marked with ◎ (fine scratches), those with 10 to less than 30 scratches were marked with ○ (light scratches), and those with 30 or more scratches were marked with x (heavy scratches).

[Example 1]
(1) Preparation of antifogging film-forming coating agent As an isocyanate prepolymer, 18.11 g of a biuret type polyisocyanate (trade name “N3200”, manufactured by Sumitomo Bayer Urethane) of hexamethylene diisocyanate was prepared. This is drug A.

4. An oxyethylene / oxypropylene copolymer having a number average molecular weight of 4000 (trade name “Toho Polyol PB-4000”; manufactured by Toho Chemical Co., Ltd.) is added to 65.53 g of a mixed solvent of isobutyl acetate and diacetone alcohol as a diluting solvent. 92 g and 2.37 g of a short-chain polyol (ethylene glycol; manufactured by Kishida Chemical Co., Ltd.) having a number average molecular weight of 62 are mixed, and a mixed solution (trade name “Acridick” having 45.0% by mass of an acrylic polyol having a number average molecular weight of 18000 is mixed therewith. 47-538-BA "(manufactured by DIC Corporation), and 0.15 g of a fluorosurfactant (Factent 212M; manufactured by Neos) as a hydrophilizing agent was added and stirred. 81.86 g of polyol mixed chemical solution was obtained. This is drug B. The solid content ratio of the oxyethylene / oxypropylene copolymer, ethylene glycol, and acrylic polyol in the drug B (hereinafter sometimes referred to as “EOPO: EG: AP ratio”) is “EOPO: EG: AP”. = 50: 20: 30 ". Further, the detergent 212M is a fluorine-containing surfactant represented by the general formula [1] wherein X and Y are single bonds and n = 12.

The above-mentioned medicine A and medicine B were mixed, and 0.03 g of dibutyltin dilaurate (hereinafter, DBTDL) was added as a curing catalyst to prepare 100 g of an antifogging film-forming coating agent.

The total solid content of the urethane-forming component in 100% by mass of the coating agent for forming an antifogging film prepared here is 30%. In addition, the content of the fluorine-containing surfactant is 0.5% by mass with respect to the total solid content of the urethane-forming component, and the number of isocyanate groups relative to the isocyanate prepolymer component of the drug A is the oxyethylene / The amount is 1.2 times the number of hydroxyl groups present in the oxypropylene copolymer, ethylene glycol, and acrylic polyol component (described as “NCO / OH ratio” in Table 1). The solid content of the drug A (isocyanate compound) was 60.5 with respect to 100 mass% of the total solid content of the urethane-forming component (in Example 1, the isocyanate compound, copolymer polyol, acrylic polyol, and short chain polyol). Mass% is included.

(2) Manufacture of antifogging film-formed article 2 g of 3- (2-aminoethylamino) propyltrimethoxysilane (manufactured by Tokyo Kasei) was added to a mixed solution of 88 g of ion-exchanged water as a diluting solvent and 10 g of ethanol. A 2% by weight solution was prepared. Next, a glass (thickness) having a mirror finish on the back surface of a transparent glass substrate with a wiper (trade name “Bencot”, model M-1, 50 mm × 50 mm, manufactured by Ozu Sangyo) made of cellulose fiber that has absorbed the solution. The surface of the glass surface of 5 mm) was wiped to apply the solution, dried at room temperature, and then washed with water with a wiper using tap water to form a primer layer. A substrate was prepared.

The coating agent for forming the antifogging film obtained above is applied to the substrate by spin coating, and the glass plate of the coating agent is heat-treated at about 150 ° C. for about 10 minutes, thereby preventing the film thickness of 10 μm. A cloudy film-formed article was obtained.

[Examples 2 to 9]
As shown in Table 1, the types, ratios and addition amounts of oxyethylene / oxypropylene copolymer, acrylic polyol, short chain polyol, polyethylene glycol, isocyanate compound and surfactant were changed. Carried out.

[Comparative Examples 1 to 7]
As shown in Table 1, the types, ratios, and addition amounts of oxyethylene / oxypropylene copolymer, short-chain polyol, acrylic polyol, polyethylene glycol, polyisocyanate and surfactant were changed, and the rest was the same as in Example 1. Carried out. In addition, Lipoquat R (manufactured by Lipochemicals) used as a surfactant in Comparative Examples 6 and 7 is a surfactant having a hydroxyl group that is an isocyanate-reactive group (ricinolamidopropylethyldimonium ethosulphate).

Table 1 shows each component of the coating agent for forming an antifogging film and its ratio for each example and each comparative example. Further, regarding the antifogging film-formed article obtained in each Example and each Comparative Example, the surface layer thickness of the surfactant / the film thickness, the film thickness, the fluorine / sulfur atomic ratio on the coating surface, the appearance The measurement results of the observation results, antifogging properties, initial water contact angle, pencil hardness, scratch resistance, and SW resistance are shown in Table 2 below.

As is apparent from Tables 1 and 2, in Examples 1 to 9, the antifogging film contains a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group, and a fluorine-containing surfactant. The surface layer thickness of the fluorine-containing surfactant is 0.001 to 2% of the film thickness, and the ratio of the number of fluorine atoms to the total number of atoms observed on the surface of the film by elemental analysis is It was 5% to 30%, and both hydrophilicity and scratch resistance were compatible. The appearance, antifogging properties and pencil hardness were also good.

It was also found that Examples 6 to 8 using 2,3-butanediol as the short-chain polyol had a pot life about 3 times longer than Example 1 using ethylene glycol.

In Examples 6 and 7 in which 0.5% by mass and 1.0% by mass of the fluorine-containing surfactant were added to the total amount of the solid content of the urethane-forming component, respectively, It turned out that it is preferable at the point of pencil hardness rather than Example 8 which added 3.0 mass% with respect to the total amount of a minute. It is estimated that the fluorine-containing surfactant is softer than the urethane resin.

Comparative Example 1 did not contain a fluorine-containing surfactant and was inferior to Examples in terms of antifogging property, hydrophilicity, and the like.

In Comparative Example 2, the fluorine atom ratio on the coating surface was small, and the antifogging property, hydrophilicity, etc. were inferior to those of the Examples.

In Comparative Example 3, the surface thickness of the fluorine-containing surfactant is as thick as 2.5% of the film thickness, and the fluorine atom ratio on the film surface is too large at 45%, so that the appearance of the film surface is cloudy. And it was bad. Moreover, the pencil hardness was also inferior to the Example.

In Comparative Example 4, when the oxyethylene / oxypropylene copolymer used in Example 1 was replaced with polyethylene glycol (PEG), the fluorine atom ratio on the coating surface was as low as 2%, and antifogging property, hydrophilicity, etc. It was inferior to the Example.

Comparative Example 5 did not contain an acrylic polyol, and the appearance, antifogging properties, hydrophilicity, etc. were inferior to those of the examples.

In Comparative Example 6, a conventionally used surfactant having a hydroxyl group which is an isocyanate-reactive group was used, but the antifogging property and hydrophilicity were inferior to those of the Examples.

In Comparative Example 7, when the addition amount of the surfactant having a hydroxyl group that is an isocyanate-reactive group was increased as compared with Comparative Example 6, the antifogging property and hydrophilicity were slightly improved, but the hydrophilicity was higher than that in Examples. In addition, scratch resistance and pencil hardness were insufficient.

Since the antifogging film-formed article of the present invention has both scratch resistance and hydrophilicity, it can be used for a long time even in an environment where wiping is frequently performed. For example, it can be used in mirrors for bathrooms and vanities, glass for automobiles, camera lenses, and the like.

Claims

An anti-fogging film comprising a urethane resin having an oxyethylene group, an oxypropylene group and an acyl group,
The antifogging film contains a fluorine-containing surfactant,
The surface layer thickness of the fluorine-containing surfactant in the antifogging film is 0.001 to 2% with respect to the film thickness of the film,
An antifogging film, wherein the ratio of the number of fluorine atoms to the total number of atoms observed on the surface of the antifogging film is 5 to 30% by elemental analysis of the antifogging film.
The antifogging film according to claim 1, wherein the fluorine-containing surfactant is a fluorine-containing surfactant represented by the following general formula [1].

(In the formula [1], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y is combined with X to form a single bond. , N is a natural number from 2 to 22.)
An antifogging film-forming article comprising a base material and the antifogging film according to claim 1 or 2 formed on the base material.
4. The antifogging film-formed article according to claim 3, wherein the film thickness of the antifogging film is 5 to 40 μm.
The antifogging film-formed article according to claim 4, wherein the substrate is glass or a mirror.
A method for producing an antifogging film-forming article comprising a base material and the antifogging film according to claim 1 formed on the base material,
An isocyanate compound having an isocyanate group,
An oxyethylene / oxypropylene copolymer polyol having a molar ratio of oxyethylene / oxypropylene of 60:40 to 90:10 and a number average molecular weight of 2000 to 15000,
An acrylic polyol having a number average molecular weight of 5000 to 25000,
A fluorine-containing surfactant represented by the following general formula [1],
Including
The solid content of the isocyanate compound is 50 to 75 mass% with respect to 100 mass% of the total solid content of the urethane-forming component,
The acrylic polyol has a solid content of 2 to 50% by mass with respect to 100% by mass of the total solid content of the polyol component,
A coating agent for forming an antifogging film, wherein the fluorine-containing surfactant is 0.1 to 5.0% by mass with respect to the total solid content of the urethane-forming component, and a substrate. Preparation, preparation process,
Applying the coating agent to the substrate; and
A method for producing an antifogging film-formed article, comprising a curing step of curing the coating agent applied to the substrate.

(In the formula [1], X represents a single bond, an alkylene group having 1 to 10 carbon atoms which may have a substituent, or an arylene group which may have a substituent, and Y represents a single bond. A bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonic acid amide bond, or an ether bond is shown, but when X is a single bond, Y is combined with X to form a single bond. , N is a natural number from 2 to 22.)