JP2012017394A - Anti-fog article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anti-fog article having excellent anti-fog properties and heat resistance.SOLUTION: This invention relates to an anti-fog article which comprises a base material and a coating film coming into close contact with the base material. The coating film is a composite film that contains a copolymer of a binder component and polyacrylic acids, wherein the coating film exhibits water absorbency. The water absorption in unit volume under water absorption saturation condition of the coating film is 0.05-3 mg/mm. The coating film has heat resistance to the temperature of ≤100°C.

Description

  In various applications such as antifogging window materials or antifogging mirrors, lenses, and displays for vehicles, buildings, etc., the present invention is resistant to heat and resistance even when exposed to heat such as solar radiation for a long time. The present invention relates to an antifogging article excellent in fogging.

  A light-transmitting base material such as glass or plastic, or a light-reflecting base material such as a mirror is used when one surface falls below the dew point due to the difference in temperature and humidity between the inner surface and the outer surface with the base material in between. When a sudden temperature and humidity change occurs on the material (such as when boiling water vapor comes into contact with the base material or when the material moves from a low-temperature part to a hot and humid environment), moisture in the atmosphere adheres as water droplets. Condensation occurs on the material surface. As a result, the field of view is hindered by the so-called “cloudiness” in which light is scattered by the condensed water droplets. Such “cloudiness” significantly impairs safety and visibility in general window glass, windshields of automobiles and aircraft, reflectors, glasses, sunglasses, and the like.

  Patent Document 1 includes an antifogging coating material comprising an inorganic alkoxide, an inorganic alkoxide hydrolyzate and an inorganic alkoxide hydrolysis polycondensate, polyacrylic acid and polyvinyl alcohol, and Disclosed is an antifogging coating film mainly composed of a composition obtained by causing at least a polycondensation reaction of a hydrolyzate of an inorganic alkoxide in the presence of polyacrylic acid and polyvinyl alcohol.

  Patent Document 2 discloses an antifogging layer made of a polyvinyl acetal resin (polyvinyl phenylacetoacetal, polyvinyl benzacetal, polyvinyl butyral, etc.) having an acetalization degree of 2 to 40 mol%.

  Antifogging films are desired to be able to maintain antifogging properties and visibility over a long period of time. For example, in applications where they are exposed to heat such as solar radiation for a long period of time, heat resistance is required for the antifogging film. The However, the antifogging film obtained in any of the above-mentioned inventions tends to yellow when heated for a long period of time and tends to cause problems in appearance and visibility.

Japanese Patent Laid-Open No. 11-061029 JP-A-6-158031

An object of the present invention is to provide an antifogging article having excellent heat resistance and antifogging properties.

The antifogging article of the present invention is an antifogging article comprising a base material and a coating adhered to the base material, the coating film being a composite film containing a binder component and a polyacrylic acid copolymer. The film is a film exhibiting water absorption, the water absorption of the unit volume at the time of water absorption saturation of the film is 0.05 to ³ mg / mm ³ , and the film is heat resistant to heat of 100 ° C. or less. It is characterized by having.

  Here, the film in close contact with the base material refers to a film that does not peel off by an artificial operation such as scratching, and that does not elute the film itself or components in the film over time. The water absorption amount in the present invention indicates the mass of water present in the coating film based on the mass of the coating film in a state where no water is absorbed.

The amount of water absorption of the unit volume to the coating at the time of water absorption saturation is set in the above range. If it is less than 0.05 mg / mm ^3, it is necessary to increase the film thickness in order to lengthen the time until water absorption is saturated. As a result, optical distortion is likely to occur, and productivity may be lowered. This is because if it exceeds ³ mg / mm ³ , the sticky feeling of the coating is increased, the strength is lowered, and the water resistance is deteriorated. A more preferable unit volume of water absorption is 0.1 to 2 mg / mm ³ .

  Moreover, it is preferable that the said film has heat resistance with respect to the heat | fever of 100 degrees C or less. 100 degreeC assumes the thermal load of the glass for motor vehicles described in JISR3212 "Safety glass test method for motor vehicles".

  In the present invention, “the coating film has heat resistance to heat of 100 ° C. or less” means that the coating film is visible or antifogging even after being exposed to heat of 100 ° C. or less. This means that there will be no defects.

  Regarding visibility, it is preferable that no defects on the appearance such as coloring, cracking, precipitation of foreign matter, distortion, etc. occur in the coating even after being exposed to heat of 100 ° C. or less.

  Regarding anti-fogging properties, even after being exposed to heat of 100 ° C. or less, for example, an anti-fogging test assuming an actual vehicle environment in a vehicle window glass (hereinafter referred to as an actual vehicle anti-fogging test). It is preferable that condensation does not occur for 10 minutes or more. Here, the actual vehicle assumed anti-fogging property test is a test in which a sample is installed between two chambers in which the temperature and humidity can be controlled as shown in FIG. The film side is assumed to be the inside of the vehicle and the substrate side is assumed to be the outside of the vehicle. The assumed outside temperature is assumed to be 20 ° C, the assumed inside temperature is 25 ° C, and the assumed inside humidity is 95%. Assuming winter, the assumed outside temperature is 0 ° C., the assumed inside temperature is 25 ° C., and the assumed inside humidity is 60%.

  The coating film has excellent heat resistance and antifogging properties due to the heat resistance of the component derived from the binder component and the water absorption and heat resistance of the component derived from the polyacrylic acid.

In addition, the binder component includes an organometallic compound (A) represented by the following general formula [1], a compound (B) in which the organometallic compound (A) is partially condensed, or the (A) and ( A mixture of B) is preferred.
R _n MX _4-n [1]
Here, R is a hydrocarbon group having 1 to 18 carbon atoms, or a partial hydrogen atom of the hydrocarbon group is substituted with at least one group selected from the group consisting of an epoxy group, a glycidoxy group, and an amino group. Organic group. M is at least one element selected from the group consisting of Si, Ti, Al, Zr, Sn, and Zn, and X is at least one group selected from an alkoxy group, a chloro group, an isocyanate group, and a hydroxy group, n is an integer of 0-3.

  It is particularly preferable that at least one of the organometallic compounds (A) is a compound in which M in the general formula [1] is Si because a film having excellent antifogging properties and heat resistance can be obtained.

  The molecular weight of the polyacrylic acid is preferably 1,000 to 250,000. When the molecular weight is less than 1,000, there is a tendency that antifogging properties are not exhibited or sufficient antifogging properties cannot be obtained. When the molecular weight is more than 250,000, the viscosity of the coating agent increases greatly, and the film formability tends to decrease. In the present invention, the molecular weight is a weight average molecular weight.

The polyacrylic acids are
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or polymethacrylic acid ester, and
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or a compound in which a part of hydrogen atoms of the methylene chain of polymethacrylic acid ester is substituted with an epoxy group, a glycidoxy group, or a substituent having reactivity with an amino group It is preferably at least one selected from the group consisting of From the viewpoint of water absorption, polyacrylic acid, polymethacrylic acid and the like are particularly preferable.

  It is preferable that polyacrylic acid is 5-60 mass% with respect to the said binder component and the total amount of polyacrylic acid. If it is less than 5% by mass, the resulting coating film tends not to exhibit antifogging properties, or sufficient antifogging properties tend not to be obtained. If it exceeds 60% by mass, polyacrylic acids cannot be immobilized in the resulting coating, and the polyacrylic acids tend to elute upon water absorption. From the viewpoint of antifogging properties and immobilization of polyacrylic acids, the amount is more preferably 10 to 50% by mass, and more preferably 20 to 40% by mass.

  Further, in order to obtain a sufficient water absorbing function of the coating, it is preferable that the thickness of the coating is 5 μm or more. As the film thickness is increased, the water absorption capacity of the film is increased. However, if the film is too thick, optical distortion is likely to occur and productivity is reduced.

  The water absorbing function can be efficiently performed by a component derived from polyacrylic acids present in the coating. The carboxyl group contained in the polyacrylic acid-derived component has a function of absorbing water as bound water, and can exhibit antifogging properties due to water absorption. A film that exhibits anti-fogging properties due to conventional water absorption may contain a component derived from polyvinyl alcohols or polyvinyl acetals as a water-absorbing component, but the polyvinyl alcohols or polyvinyl acetals in the coating obtained in the present invention. It is preferable that the component derived from a class is 5 mass% or less. If it exceeds 5% by mass, the film tends to be colored by heat of 100 ° C. or less, which is not preferable. A more preferable concentration of the component derived from polyvinyl alcohols or polyvinyl acetals in the coating is 1% by mass or less, more preferably 0.01% by mass or less. Further, in the obtained coating, the polyvinyl alcohols or It is particularly preferable that components derived from polyvinyl acetals are not substantially contained.

  Moreover, it is preferable that the refractive index difference of the said base material and the said film is less than 10%. If the refractive index difference is more than 10%, the interference action is increased, and the visibility is lowered, and interference fringes and coloring are observed visually, which is not preferable. More preferably, the refractive index difference is within 5%. The refractive index difference (%) is obtained by measuring the refractive index of the substrate and the coating at a wavelength of 633 nm with an ellipsometer, and the absolute value of (refractive index of coating-refractive index of substrate) / refractive index of substrate) × 100. Calculate as a value.

Moreover, it is preferable that the antifogging article of the present invention is produced through at least the following steps.
(1) A step of preparing a coating agent for forming a film containing a binder component and polyacrylic acids (2) A step of applying the coating agent for forming a film, and (3) A step of curing the coating film

  Since the antifogging article of the present invention is excellent in heat resistance and antifogging property, it can be used in members and applications that are exposed to heat for a long period of time. The effect is particularly remarkable when used for a window material for a vehicle, and a safe and comfortable interior environment can be provided.

Schematic diagram of actual vehicle anti-fogging test using a two-chamber environmental tester

The antifogging article of the present invention is an antifogging article comprising a base material and a coating adhered to the base material, the coating film being a composite film containing a binder component and a polyacrylic acid copolymer. The film is a film exhibiting water absorption, the water absorption of the unit volume at the time of water absorption saturation of the film is 0.05 to ³ mg / mm ³ , and the film is heat resistant to heat of 100 ° C. or less. Have

The antifogging article of the present invention is produced through at least the following steps.
(1) A step of preparing a coating agent for forming a film containing a binder component and polyacrylic acids (2) A step of applying the coating agent for forming a film, and (3) A step of curing the coating film

  As the substrate, those having light transmittance, light reflectivity, or glossiness, and those whose safety, appearance, and design properties are significantly impaired by fogging are used.

  Glass is used as a typical base material having optical transparency. 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. In addition to glass, tempered glass, similar glass, laminated glass, multilayer glass and the like can be used. In addition to the above plate glass, for example, a resin film such as polyethylene terephthalate, a resin plate such as polycarbonate and acrylic, and the like can also be used.

  Moreover, as a typical base material having light reflectivity, a mirror, a metal, a metal-plated article, or the like produced by a silvering method or a vacuum film forming method can be used.

  In addition, as a typical base material having gloss, metal, metal-plated articles, ceramics, and the like can be used.

  Various molded bodies, such as a flat plate and a bending board, can be used for said base material. The plate thickness is not particularly limited, but is preferably 1.0 mm or more and 10 mm or less. For example, the window material for a vehicle is preferably 1.0 mm or more and 5.0 mm or less. The formation of the coating on the substrate may be performed on only one side of the substrate or on both sides. In addition, the coating may be formed on the entire surface of the base material or a part thereof.

  The coating film is preferably a composite film containing a binder component and a copolymer of polyacrylic acids. The coating film has excellent heat resistance and antifogging properties due to the heat resistance of the component derived from the binder component and the water absorption and heat resistance of the component derived from the polyacrylic acid.

  The coating preferably contains a component having a metalloxane bond derived from a binder component, and the component is preferably a component obtained by condensing an organometallic compound. Furthermore, the composite film in which the binder component and the polyacrylic acid are combined can prevent the elution of the component derived from the polyacrylic acid from the film, and can exhibit antifogging properties over a long period of time. Since it becomes difficult to deteriorate, it is more preferable that the organometallic compound is copolymerized with polyacrylic acids.

As the organometallic compound, an organometallic compound (A) represented by the following general formula [1], a compound (B) in which the organometallic compound (A) is partially condensed, or the (A) and (B ) Can be used.
R _n MX _4-n [1]
Here, R is a hydrocarbon group having 1 to 18 carbon atoms, or a partial hydrogen atom of the hydrocarbon group is substituted with at least one group selected from the group consisting of an epoxy group, a glycidoxy group, and an amino group. Organic group. M is at least one element selected from the group consisting of Si, Ti, Al, Zr, Sn, and Zn, and X is at least one group selected from an alkoxy group, a chloro group, an isocyanate group, and a hydroxy group, n is an integer of 0-3.

  Examples of the organometallic compound (A) include methoxytrimethylsilane, ethoxytriethylsilane, (chloromethyl) dimethylisopropoxysilane, and [bicyclo [2.2.1] hept-5-en-2-yl] triethoxy. Silane, trimethyl [3- (triethoxysilyl) propyl] ammonium chloride, trimethoxy [3- (phenylamino) propyl] silane, trimethoxysilane, trimethoxyphenylsilane, trimethoxy (propyl) silane, trimethoxy (p-tolyl) silane , Trimethoxy (methyl) silane, triethoxysilane, triethoxyphenylsilane, triethoxymethylsilane, triethoxyfluorosilane, triethoxyethylsilane, triethoxy-1H, 1H, 2H, 2H-tridecafluoro-n-o Tylsilane, pentyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, N- [2- (N-vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane hydrochloride, n-octyltriethoxysilane, n -Dodecyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, ethyltrimethoxysilane, dodecyltrimethoxysilane, cyclohexyltrimethoxysilane, bis [3- (trimethoxysilyl) propyl] amine, benzyltriethoxysilane, 3 -Ureidopropyltriethoxysilane, 3-trimethoxysilylpropyl chloride, 3-glycidyloxypropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-aminopro Pyrtrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (triethoxysilyl) propyl isocyanate, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propyltriethoxy Silane, 2-cyanoethyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 1- [3- (trimethoxysilyl) propyl] urea, 1,2-bis (trimethoxysilyl) ethane, (Chloromethyl) triethoxysilane, (3-mercaptopropyl) trimethoxysilane, (3-mercaptopropyl) triethoxysilane, (3-bromopropyl) trimethoxysilane, tetrapropyl orthosilicate, tetramethyl orthosilicate, Orthosilicic acid tetrakis (1 1,1,3,3,3-hexafluoroisopropyl), tetraisopropyl orthosilicate, tetraethyl orthosilicate, tetrabutyl orthosilicate, dimethoxymethylphenylsilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, dimethoxydi-p-tolylsilane, Dimethoxy (methyl) silane, diethoxymethylsilane, diethoxydiphenylsilane, diethoxydimethylsilane, diethoxy (methyl) phenylsilane, diethoxy (3-glycidyloxypropyl) methylsilane, cyclohexyl (dimethoxy) methylsilane, 3-mercaptopropyl (dimethoxy) ) Methylsilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, 3-chloropropyldimethoxymethylsilane, 3-aminopropyldiet Cymethylsilane, 3- (2-aminoethylamino) propyldimethoxymethylsilane, 1,5-dichloro-1,1,3,3,5,5-hexamethyltrisiloxane, 1,3-dimethoxy-1,1,3 , 3-tetraphenyldisiloxane, 1,3-dichloro-1,1,3,3-tetramethyldisiloxane, 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane, 1,1, 3,3,5,5,5-heptamethyl-3- (3-glycidyloxypropyl) trisiloxane, 3-chloropropyldichloromethylsilane, chloromethyl (dichloro) methylsilane, di-tert-butyldichlorosilane, dibutyldichlorosilane , Dichloro (methyl) octadecylsilane, dichloro (methyl) phenylsilane, dichlorocyclohexylme Tylsilane, dichlorodecylmethylsilane, dichlorodiethylsilane, dichlorodihexylsilane, dichlorodiisopropylsilane, dichlorodimethylsilane, dichlorodipentylsilane, dichlorodiphenylsilane, dichlorododecylmethylsilane, dichloroethylsilane, dichloromethylsilane, dichloromethylsilane, n -Octylmethyldichlorosilane, tetrachlorosilane, 1,2-bis (trichlorosilyl) ethane, 3-chloropropyltrichlorosilane, bis (trichlorosilyl) acetylene, butyltrichlorosilane, cyclohexyltrichlorosilane, decyltrichlorosilane, dodecyltrichlorosilane, Ethyltrichlorosilane, hexachlorodisilane, 1,1,2,2-tetrachloro-1,2-dimethyldi Lan, isobutyltrichlorosilane, n-octyltrichlorosilane, phenyltrichlorosilane, texyltrichlorosilane, trichloro (methyl) silane, trichloro (propyl) silane, trichloro-2-cyanoethylsilane, trichlorohexylsilane, trichlorooctadecylsilane, trichlorosilane , Trichlorotetradecylsilane, (3-cyanopropyl) dimethylchlorosilane, (bromomethyl) chlorodimethylsilane, (chloromethyl) dimethylchlorosilane, 1,2-dichlorotetramethyldisilane, 1,3-dichloro-1,1,3 3-tetramethyldisiloxane, 1,5-dichloro-1,1,3,3,5,5-hexamethyltrisiloxane, α- (chlorodimethylsilyl) cumene, benzylchlorodimethylsilane , Butylchlorodimethylsilane, chloro (decyl) dimethylsilane, chloro (dodecyl) dimethylsilane, chlorodiisopropylsilane, chlorodimethylphenylsilane, chlorodimethylpropylsilane, chlorodimethylsilane, chlorotriethylsilane, chlorotrimethylsilane, diethylisopropylsilyl chloride Organic silicon such as dimethyl-n-octylchlorosilane, dimethylethylchlorosilane, dimethylisopropylchlorosilane, diphenylmethylchlorosilane, pentafluorophenyldimethylchlorosilane, tert-butyldimethylchlorosilane, tert-butyldiphenylchlorosilane, triisopropylsilyl chloride, triphenylchlorosilane Compounds, titanium tetramethoxide, titanium tetraethoxide Organic titanium compounds such as aluminum ethoxide, aluminum isopropoxide, aluminum butoxide, aluminum trichloride, zirconium ethoxide, zirconium isopropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, and titanium tetrachloride. Organic zirconium compounds such as propoxide, zirconium butoxide, zirconium tetrachloride, organic tin compounds such as tin methoxide, tin ethoxide, tin isopropoxide, tin butoxide, tin dichloride, dimethoxy zinc, diethoxy zinc, di-n- Examples thereof include organic zinc compounds such as propoxy zinc, di-n-butoxy zinc and zinc dichloride. In particular, an organosilicon compound is preferred from the transparency and cost of the resulting coating.

  It is important to select the organometallic compound so that the refractive index difference between the substrate and the coating is within 10% in consideration of the matching of the refractive index of the substrate and the coating. For example, when glass is used as the substrate, the organometallic compound is preferably an organosilicon compound from the viewpoint of refractive index matching and adhesion to the substrate. Moreover, you may use in combination of multiple types of said organometallic compound.

  In addition, it is particularly preferable that at least one of the organometallic compounds (A) is a compound in which M in the general formula [1] is Si because a film having excellent antifogging properties and heat resistance can be obtained.

As polyacrylic acids,
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or polymethacrylic acid ester, and
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or a compound in which a part of hydrogen atoms of the methylene chain of polymethacrylic acid ester is substituted with an epoxy group, a glycidoxy group, or a substituent having reactivity with an amino group At least one selected from the group consisting of can be used.

ここで、反応性基Ｙはアミノ基、水酸基、エポキシ基、メルカプト基、イソシアナート基、アルコキシ基、ビニル基、アクリル基、もしくはメタクリル基などであり、ｓは１０〜３５０、ｔは５〜２００であることが好ましい。 Examples of the reactive substituent include an amino group, a hydroxyl group, an epoxy group, a mercapto group, an isocyanate group, an alkoxy group, a vinyl group, an acrylic group, and a methacryl group. Moreover, as polyacrylic acid, the compound which the site | part which has polyacrylic acid and the reactive group Y as shown by the following general formula [2] copolymerized may be sufficient.

Here, the reactive group Y is an amino group, a hydroxyl group, an epoxy group, a mercapto group, an isocyanate group, an alkoxy group, a vinyl group, an acrylic group, or a methacryl group, and s is 10 to 350, and t is 5 to 200. It is preferable that

  The compound of the general formula [2] may be a block copolymer, an alternating copolymer, or a random copolymer. Moreover, s and t represent the number of each repeating unit in the case of a block copolymer, and represent the total number of each structural unit in the case of an alternating copolymer and a random copolymer.

Adjust the amount of polyacrylic acid added to adjust the amount of water-absorbing components derived from polyacrylic acid in the coating so that the water absorption of the unit volume in the coating at the time of water absorption saturation is 0.05 to ³ mg / mm ^3. . The water-absorbing component is preferably a carboxyl group or a sodium salt of a carboxyl group contained in polyacrylic acids.

  In the step of preparing the coating agent for forming a film, the coating agent may contain a solvent. The solvent is not particularly limited as long as it dissolves the coating agent, and examples thereof include water, methyl alcohol, ethyl alcohol, propyl alcohol, butanol, ethylene glycol, 1,2-propanediol, and cyclohexanol. From the viewpoints of compatibility and safety, ethyl alcohol is preferred. Moreover, it is good also as a mixed solvent using a some solvent.

  In addition, a catalyst may be added to the coating agent for forming a film for the purpose of promoting the curing reaction of the coating agent. When an acidic aqueous solution is used as the catalyst, an aqueous solution having an acid catalyst such as an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, or an organic acid such as acetic acid, phthalic acid or succinic acid may be selected according to the hydrolysis rate. preferable. At this time, the acid catalyst is preferably added so that the pH value in the coating agent is 1 to 5.

  In addition, a metal complex such as tin, aluminum, titanium, or zirconium can be used as the catalyst. Here, the metal complex is preferably a fluoride, chloride, bromide, iodide, acetate, nitrate, sulfate, acetylacetonate salt or the like. The catalyst may be added up to 0.05 times the mass ratio of the organometallic compound in the coating agent. Even if it exceeds 0.05 times the amount, there is a tendency that the catalytic effect with respect to the amount added does not further improve, so that it is not necessary to add a large amount of catalyst. On the other hand, in order to exert a catalytic effect, the curing catalyst is preferably added in an amount of 0.0001 times or more by mass ratio to the amount of silicon compound B in the treating agent.

  In addition, the coating agent for forming a film includes, as a component other than the polyacrylic acids and the binder component, a photopolymerization initiator, a thermal polymerization initiator, a surfactant, a crosslinking agent, as long as the object of the present invention is not impaired. You may add other components, such as antioxidant, a ultraviolet absorber, an infrared absorber, a flame retardant, a hydrolysis inhibitor, and an antifungal agent.

  When the other component is a component having a hydroxyl group, a carbonyl group, an amino group, a carboxyl group, a sulfo group, etc., in addition to the water absorption effect due to the component derived from the polyacrylic acid, the water absorption effect due to the hydrophilicity of the other component Is preferable because it is promoted.

  Known coatings such as dip coating, flow coating, spin coating, roll coating, spray coating, screen printing, flexographic printing, hand coating, and ink jet coating on a base material containing a coating agent containing the organometallic compound and the polyacrylic acid. A film can be obtained by applying and curing by means.

  As a method for curing the coating film of the coating agent for film formation, it can be cured by heat curing, photocuring or the like. In the case of thermosetting, the heating temperature is preferably 50 to 200 ° C, more preferably 80 to 150 ° C. If it is less than 50 degreeC, since a cure rate is slow and hardening takes time, it is unpreferable. Further, if it exceeds 200 ° C., polyacrylic acids are likely to deteriorate, which is not preferable. When photocuring, a general radical polymerization initiator or cationic polymerization initiator is used, and the light irradiation method is not particularly limited, and a high-pressure mercury lamp, a xenon lamp, or the like can be used.

  Further, in order to further improve the durability of the antifogging article, a treatment for improving the adhesive strength between the base material and the coating film can be performed on the base material surface in advance. Examples of the treatment include primer treatment, plasma irradiation, corona discharge, and high-pressure mercury lamp irradiation.

  In the primer treatment, it is preferable to apply a liquid having a silane coupling agent as a primer on the surface of the base material before application of the coating liquid. As a suitable silane coupling agent, for example, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be used.

  Hereinafter, the present invention will be described specifically by way of examples. In addition, quality evaluation was performed by the method shown below for the anti-fogging articles obtained in the present examples and comparative examples.

[Appearance evaluation]
The appearance of the film-formed product was confirmed by visual observation, and a sample having no defects in appearance such as interference fringes, coloring, and perspective distortion was indicated as (◯), and a sample having defects in appearance was indicated as (×).

[Measurement of water absorption per unit volume of coating]
Measure the mass (a) of the antifogging article after being held in a drying oven at a temperature of 80 ° C. for 2 hours, and contact the coating with 35 ° C. saturated water vapor until the entire exposed surface becomes cloudy. After wiping, the mass (b) of the antifogging article was measured. The amount of water absorption per unit volume was the value obtained by the formula {(b−a) / (steam exposure area × film thickness)} as the water absorption per unit volume. The value (a) here corresponds to that in a state in which the film does not absorb water. A sample having a water absorption of 0.05 to ³ mg / mm ³ was designated as (◯), and a sample outside the range was designated as (×).

[Film thickness measurement]
Using a stylus type surface roughness meter (manufactured by Kosaka Laboratory, Surfcorder ET-4000A), the film thickness of the coating after being held for 12 hours in an environment of 50% humidity and 55 ° C. was measured.

[Refractive index evaluation]
The refractive index of the substrate and the film at a wavelength of 633 nm is measured with an ellipsometer (DVA-FL3G type manufactured by Mizoji Optical Co., Ltd.) using a He-Ne laser as the light source, and the difference in refractive index between the substrate and the film is within 10%. Was acceptable (O), and those exceeding 10% were regarded as unacceptable (X).

[35 ° C water vapor defogging test]
At the top of the tank filled with 35 ° C. saturated steam, the sample is placed with the coating surface facing the tank, and the time until cloudiness occurs is measured. (X) is a case where a problem occurred in appearance or in appearance.

[Real car anti-fogging test]
As shown in FIG. 1, a sample is installed between two chambers using a two-chamber environmental tester (model TBL-2HW2P1A / TBU-2HW0P2A manufactured by Tabai Espec), and the temperature and humidity of the two chambers are close to actual use. The time until dew condensation occurred was measured under the following conditions, and those with 10 minutes or more were evaluated as (◯), those with less than 10 minutes, or those with defects in appearance as (X).
Condition 1: Assumed rainy season Assumed temperature outside the vehicle 20 ° C, assumed temperature inside the vehicle 25 ° C, assumed humidity inside the vehicle 95%
Condition 2: Assuming winter season The assumed constant temperature outside the vehicle is 0 ° C, the assumed constant temperature inside the vehicle is 25 ° C, and the assumed constant temperature inside the vehicle is 60%

[Heat resistance test]
A sample held for 200 hours in a constant temperature bath held at 100 ° C., with no defects in appearance, and those that passed the anti-fogging property (35 ° C. water vapor anti-fogging property, actual vehicle anti-fogging property) test (○) The case where the appearance was defective or the case where the anti-fogging property was rejected was defined as (x).

Example 1
[Preparation of substrate]
As the substrate, a float glass having a thickness of 3 mm and 100 mm square was used. The surface of the substrate glass was polished with ceria fine particles, washed by brushing and dried.

[Preparation of coating agent for film formation]
41.53 g of methyl alcohol, 10.14 g of ion-exchanged water, and 10 g of polyacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.) having a molecular weight of 25,000 were added and mixed with stirring until dissolved. Thereafter, 12.72 g of 3-glycidoxypropyltrimethoxysilane (hereinafter referred to as GPTMS) (manufactured by Shin-Etsu Silicone, trade name: KBE-403), methyltriethoxysilane (hereinafter referred to as MTES) (Shin-Etsu Silicone) Product, product name: KBE-13) 15.48 g, 10.14 g of 1N nitric acid was added, and the mixture was stirred at 23 ° C. for 16 hours to obtain 100 g of a coating-forming coating agent.

[Preparation of anti-fogging articles]
The coating agent was applied to the base glass by a spin coating method. The base glass on which the coating agent was applied was placed in an electric furnace maintained at 100 ° C. for 16 hours and cured to form a coating. Table 1 shows the quality evaluation results. This film had no defects in appearance, the film thickness was 35 μm, and the water absorption amount per unit volume of the film was 0.7 mg / mm ³ , which was “good”. Moreover, the refractive indexes of the float glass of a base material and the obtained coating film were 1.52 and 1.48, respectively, and the refractive index difference was 3%, and was (circle). The 35 ° C. water vapor anti-fogging property of the anti-fogging article was ◯ at 120 seconds, the actual vehicle anti-fogging test was ◯ for 60 minutes or more under Condition 1, and ◯ at 21 minutes under Condition 2. Moreover, even after holding the antifogging article at 100 ° C. for 200 hours as a heat resistance test, there is no defect in appearance, and it passes the antifogging property (35 ° C. water vapor antifogging property, antifogging property assumed in actual vehicles) test, ○.

Example 2
In Example 1 [Preparation of coating agent for forming anti-fogging film], in addition to GPTMS and MTES as binder components, titanium tetraisopropoxide (manufactured by Wako Pure Chemical Industries, Ltd.) (hereinafter referred to as TiTIP) is used. 15 g was added, and an antifogging article was obtained by the same operation as in Example 1 except that lead-based glass having a refractive index of 1.80 was used as a base material. This coating film had no defects in appearance, the film thickness was 35 μm, and the water absorption amount per unit volume of the coating film was ◯ at 0.2 mg / mm ³ . Moreover, the refractive index of the obtained film was 1.68, the refractive index difference was 7%, and it was good. The 35 ° C. water vapor anti-fogging property of the anti-fogging article was ○ in 35 seconds, the actual vehicle anti-fogging test was 30 minutes in Condition 1, and ○ in Condition 2 was ○ in 12 minutes. Moreover, even after holding the antifogging article at 100 ° C. for 200 hours as a heat resistance test, there is no defect in appearance, and it passes the antifogging property (35 ° C. water vapor antifogging property, antifogging property assumed in actual vehicles) test, ○.

Comparative Example 1
Similar to Example 1 except that 10 g of polyvinyl alcohol (made by Kishida Chemical Co., Ltd.) having a molecular weight of 2,000 was used in place of 10 g of polyacrylic acid in “Preparation of antifogging film-forming coating agent” in Example 1. The anti-fogging article was obtained by the operation. In the film of this antifogging article, no defects in appearance were observed, the film thickness was 35 μm, the water absorption per unit volume of the film was 1.0 mg / mm ³ , and the refraction of the obtained film was The rate is 1.49, the refractive index difference is 2%, and the 35 ° C. water vapor anti-fogging property is ○ in 150 seconds, and the actual vehicle anti-fogging property test is 60 minutes or more in Condition 1 and in Condition 2 Although it was (circle) in 30 minutes, the film | membrane turned yellow by holding | maintaining this anti-fogging article at 100 degreeC for 200 hours as a heat resistance test, and was x.

Comparative Example 2
An antifogging article was obtained in the same manner as in Example 1 except that polyvinyl acetal having a degree of acetalization of 9% (KX-1, solid content 9%, manufactured by Sekisui Chemical Co., Ltd.) was used as a coating agent for forming an antifogging film. In the film of this antifogging article, no defects in appearance were observed, the film thickness was 10 μm, the water absorption per unit volume of the film was 1.5 mg / mm ³ , and the obtained film was refracted. The rate is 1.46, the refractive index difference is 4%, ○, the 35 ° C. water vapor anti-fogging property is ○ in 60 seconds, the actual vehicle anti-fogging property test is 60 minutes in condition 1, and 15 in condition 2. Although it was (circle) in minutes, the film | membrane turned yellow and was x by hold | maintaining this anti-fogging article at 100 degreeC for 200 hours as a heat resistance test.

Comparative Example 3
An antifogging article was obtained in the same manner as in Example 1 except that the amount of polyacrylic acid added was changed to 1 g in [Preparation of antifogging film-forming coating agent] in Example 1. In the coating of this antifogging article, no defects in appearance were observed, the film thickness was 35 μm, the water absorption of the unit volume of the coating was 0.01 mg / mm ³ , and the refraction of the obtained coating was The rate is 1.48, the refractive index difference is 3%, and the 35 ° C. water vapor anti-fogging property is x in 5 seconds, the actual vehicle anti-fogging property test is 3 minutes in condition 1, and x in condition 2 is 1 X in minutes. In addition, as a heat resistance test, the appearance of the antifogging article was not defective even when it was held at 100 ° C. for 200 hours, but the antifogging property (35 ° C. water vapor antifogging property, anti-fogging property of actual vehicle) was rejected. And x.

Comparative Example 4
An antifogging article was obtained in the same manner as in Example 1 except that the amount of polyacrylic acid added was changed to 50 g in [Preparation of antifogging film-forming coating agent] in Example 1. This film had stickiness and had a perspective distortion in appearance x, the film thickness was 35 μm, and the water absorption amount per unit volume of the film was 3.2 mg / mm ³ . Moreover, the refractive indexes of the float glass of a base material and the obtained coating film were 1.52 and 1.48, respectively, and the refractive index difference was 3%, and was (circle). The anti-fogging article had a 35 ° C. water vapor anti-fogging property of no fogging even after 300 seconds, but the stickiness of the film deteriorated and there was a perspective distortion. In condition 2, it was 50 minutes, but the stickiness of the film deteriorated after the test, and there was a perspective distortion. In addition, even after the antifogging article was held at 100 ° C. for 200 hours as a heat resistance test, there was stickiness and perspective distortion was observed on the appearance ×, antifogging properties (35 ° C. water vapor antifogging property, anti-fogging assumed for actual vehicles) The test was also rejected as x.

Comparative Example 5
An antifogging article was obtained in the same manner as in Comparative Example 1 except that lead-based glass having a refractive index of 1.80 was used as the substrate. This coating film had a perspective distortion X in appearance, a film thickness of 35 μm, and a water absorption amount per unit volume of the coating film of 1.0 mg / mm ³ was ◯. Moreover, the refractive index of the float glass of a base material and the obtained coating film was 1.80 and 1.49, respectively, and the refractive index difference was 17% and was x. The 35 ° C. water vapor anti-fogging property of the anti-fogging article was ○ in 150 seconds, the actual vehicle anti-fogging test was ○ for 60 minutes or more in Condition 1, and ○ in 30 minutes in Condition 2. Further, as a heat resistance test, the film was yellowed by holding the antifogging article at 100 ° C. for 200 hours, and the result was x.

1 Assumed temperature outside the vehicle (temperature control)
2 Assumed constant temperature chamber (temperature / humidity control)
3 Wall material that separates vehicle exterior and vehicle interior 4 Anti-fogging article 5 Base material 6 Coating

Claims (10)

An anti-fogging article comprising a substrate and a coating adhered to the substrate, wherein the coating is a composite film containing a binder component and a polyacrylic acid copolymer, and the coating exhibits water absorption. An anti-fogging characterized in that the film has a water absorption amount of 0.05 to ³ mg / mm ³ when saturated with water absorption, and the film has heat resistance against heat of 100 ° C. or less. Sex goods. The binder component is an organometallic compound (A) represented by the following general formula [1], a compound (B) in which the organometallic compound (A) is partially condensed, or the (A) and (B). The antifogging article according to claim 1, wherein the antifogging article is mixed.
R _n MX _4-n [1]
(In the formula [1], R is a hydrocarbon group having 1 to 18 carbon atoms, or at least one hydrogen atom selected from the group consisting of an epoxy group, a glycidoxy group, and an amino group as a partial hydrogen atom of the hydrocarbon group. M is an organic group substituted with a group, and M is at least one element selected from Si, Ti, Al, Zr, Sn, and Zn, and X is a group consisting of an alkoxy group, a chloro group, an isocyanate group, and a hydroxy group. At least one group selected, and n is an integer of 0 to 3.) The antifogging article according to claim 1 or 2, wherein at least one of the organometallic compounds (A) is a compound in which M in the general formula [1] is Si. The anti-fogging article according to any one of claims 1 to 3, wherein the polyacrylic acid has a molecular weight of 1,000 to 250,000. The polyacrylic acids are
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or polymethacrylic acid ester, and
Polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, or a compound in which a part of hydrogen atoms of the methylene chain of polymethacrylic acid ester is substituted with an epoxy group, a glycidoxy group, or a substituent having reactivity with an amino group The antifogging article according to any one of claims 1 to 4, wherein the antifogging article is at least one selected from the group consisting of: The antifogging article according to any one of claims 1 to 5, wherein the polyacrylic acid is 5 to 60% by mass based on the total amount of the binder component and the polyacrylic acid. The antifogging article according to any one of claims 1 to 6, wherein the film has a thickness of 5 to 100 µm. The antifogging article according to any one of claims 1 to 7, wherein the water absorption of the film is performed by a component derived from polyacrylic acid present in the film. The antifogging article according to any one of claims 1 to 8, wherein a difference in refractive index between the base material and the coating film is within 10%. The method for forming an antifogging article according to any one of claims 1 to 9, wherein the antifogging article is produced through at least the following steps.
(1) A step of preparing a coating agent for forming a film containing a binder component and polyacrylic acids (2) A step of applying the coating agent for forming a film, and (3) A step of curing the coating film

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