Anti-fog liquid composition and article equipped with Anti-fog film

Abstract

Provided is an anti-fog liquid composition comprising: a polyvinyl acetal; and an aminosilane A that has an amino group and a silanol group but that does not have an alkoxy group. Also provided is an article equipped with an anti-fog film, said article comprising a base material and an anti-fog film on the base material, wherein the anti-fog film contains a polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the article is kept in an atmosphere of 85°C and 85% RH for 1,000 hours is not more than 7%.

Description

Anti-fogging liquid composition and article with anti-fogging film

[0001] The present invention relates to an anti-fogging liquid composition and an article with an anti-fogging film.

[0002] Anti-fogging films have been developed to impart anti-fogging properties to substrates, particularly transparent substrates. Anti-fogging liquid compositions are typically used to form anti-fogging films. Patent Document 1 discloses an anti-fogging film having high anti-fogging properties and a liquid composition for forming the anti-fogging film. The anti-fogging film disclosed in Patent Document 1 contains a water-absorbing polymer, a silane coupling agent, a polyether-modified siloxane, and the like. Polyvinyl acetal is used as the water-absorbing polymer, and a silane coupling agent having an amino group is used as the silane coupling agent.

[0003] International Publication No. 2022 / 260146

[0004] The anti-fogging film disclosed in Patent Document 1 tends to yellow significantly when exposed to a high-temperature, high-humidity atmosphere for a long period of time. An object of the present invention is to provide an article with an anti-fogging film that exhibits little yellowing even when exposed to a high-temperature, high-humidity atmosphere for a long period of time, and a liquid composition suitable for forming the film.

[0005] The present invention provides an anti-fogging liquid composition comprising: a polyvinyl acetal; and an aminosilane A having an amino group and a silanol group but no alkoxy group.

[0006] In another aspect, the present invention provides an anti-fogging film-equipped article comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the anti-fogging film is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1000 hours is 7% or less.

[0007] In another aspect, the present invention provides an anti-fogging film-equipped article comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the anti-fogging film is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1000 hours is 4% or less, expressed as a value converted to a film thickness of 1 μm for the anti-fogging film.

[0008] According to the present invention, it is possible to provide an article with an anti-fogging film that undergoes little yellowing even when exposed to a high-temperature, high-humidity atmosphere for a long period of time, and a liquid composition suitable for forming the film.

[0009] 1 is a cross-sectional view showing one embodiment of an article with an anti-fogging film according to the present invention.

[0010] The present invention will be described in detail below, but the following description is not intended to limit the present invention to a specific embodiment. In this specification, "major component" means the component with the highest content by mass. "Substantially not contained" means a content of less than 0.1%, less than 0.05%, or even less than 0.01% by mass. "(Meth)acrylic" and "(meth)acrylate" mean acrylic and methacrylic, and acrylate and methacrylate, respectively.

[0011] [Background to the Invention] The present inventors discovered that the combination of polyvinyl acetal and a silane coupling agent having an amino group promotes yellowing. The omission of the silane coupling agent having an amino group suppresses yellowing of anti-fogging films under high temperature and high humidity conditions. However, this does not achieve the effects of the amino group, such as improved adhesion between the film and the substrate. After further investigation, the present inventors discovered that yellowing can be suppressed while retaining the amino group by using an aminosilane (aminosilane A) that has an amino group and a silanol group but no alkoxy group. The yellowing caused by keto-enol tautomerism in polyvinyl acetal may be promoted by the nucleophilic reaction of the amino group with the polyvinyl acetal. The nucleophilicity of the amino group is relatively reduced in aminosilane A containing a silanol group compared to silane coupling agents containing an alkoxy group. The suppression of yellowing by aminosilane A is thought to be due to the reduced nucleophilicity of the amino group.

[0012] It is known that in liquid compositions, alkoxy groups are partially hydrolyzed and converted into silanol groups. However, the ratio of alkoxy groups that are hydrolyzed tends to be limited in reality. In particular, in liquid compositions that do not contain a hydrolysis catalyst or that contain an acid catalyst as a hydrolysis catalyst, this ratio is in a relatively low range. The inhibition of yellowing by aminosilane A is thought to be due to the fact that the hydrolysis of the alkoxy groups contained in the silane coupling agent does not actually proceed sufficiently.

[0013] [Anti-fogging liquid composition] In one embodiment of the present invention, the anti-fogging liquid composition comprises polyvinyl acetal and aminosilane A having an amino group and a silanol group but no alkoxy group. The anti-fogging liquid composition may further comprise other aminosilanes (for example, aminosilane B described below), an epoxy group-containing compound, a tetraalkoxysilane, a polyether-modified siloxane, a (meth)acrylic acid ester, etc.

[0014] (Polyvinyl acetal) Polyvinyl acetal is obtained by acetalizing polyvinyl alcohol by a condensation reaction with an aldehyde. The acetalization of polyvinyl alcohol may be carried out by a known method such as a precipitation method using an aqueous medium in the presence of an acid catalyst or a dissolution method using a solvent such as alcohol. The acetalization may also be carried out in parallel with the saponification of polyvinyl acetate. The degree of acetalization may be 2 to 40 mol%, preferably 3 to 30 mol%, particularly 5 to 20 mol%, and in some cases 5 to 15 mol%. The degree of acetalization may be, for example, 13 The degree of acetalization can be measured by C nuclear magnetic resonance spectroscopy. Polyvinyl acetal having a degree of acetalization within the above range is suitable for forming an anti-fogging film having good water absorption and water resistance. However, it is also susceptible to yellowing.

[0015] The average degree of polymerization of the polyvinyl acetal may be 200 to 4500, or even 500 to 4500. A high average degree of polymerization is advantageous for forming an anti-fogging film with good water absorption and water resistance, but if the average degree of polymerization is too high, the viscosity of the solution may become too high, which may hinder film formation. The saponification degree of the polyvinyl alcohol is, for example, 75 to 99.8 mol %.

[0016] Examples of aldehydes to be condensed with polyvinyl alcohol include aliphatic aldehydes such as formaldehyde, acetaldehyde, butylaldehyde, hexylcarbaldehyde, octylcarbaldehyde, and decylcarbaldehyde. Other examples include benzaldehyde; 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, and other alkyl-substituted benzaldehydes; chlorobenzaldehyde and other halogen-substituted benzaldehydes; substituted benzaldehydes in which hydrogen atoms are substituted with functional groups other than alkyl groups, such as hydroxy groups, alkoxy groups, amino groups, and cyano groups; and condensed aromatic ring aldehydes such as naphthaldehyde and anthraldehyde. Aromatic aldehydes, which are highly hydrophobic, are advantageous for forming a water-absorbing film with a low degree of acetalization and excellent water resistance. The use of an aromatic aldehyde is advantageous in that it allows the formation of a film with high water absorption while leaving many hydroxyl groups. The polyvinyl acetal preferably contains an acetal structure derived from an aromatic aldehyde, particularly benzaldehyde.

[0017] The content of polyvinyl acetal in the anti-fogging liquid composition is, for example, 1 to 10%, 2 to 8%, or even 3 to 7% by mass of the solid content. Polyvinyl acetal may be the main component of the solid content of the anti-fogging liquid composition or the main component of the anti-fogging film.

[0018] (Aminosilane A) Aminosilane A is a compound that has an amino group and a silanol group, but does not have an alkoxy group. The silanol group is represented by Si—OH. Aminosilane A differs from general silane coupling agents in that it does not have an alkoxy group represented by Si—OR. R is an organic group, typically an alkyl group having 1 to 4 carbon atoms.

[0019] The aminosilane A may have a primary or secondary amino group as the amino group, and preferably has a primary amino group. The primary amino group significantly contributes to improving the adhesion of the anti-fogging film to the substrate. The aminosilane A may have two or more primary amino groups, or may have two or three or more primary amino groups. The aminosilane A has at least one, preferably two or more silanol groups. The aminosilane A may have two or more hydroxyl groups bonded to one silicon atom.

[0020] Aminosilane A may have the structure shown in Formula I: 1 HN-R 3 -Si(OH)2-O-Si(OH)2-R 4 -NHR 2 In Formula I, R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group. 3 and R 4 are divalent organic groups which may be the same or different from each other. The divalent organic group may be a linear or branched alkylene group.

[0021] Aminosilane A may have the structure shown in Formula II: (R 1 HN) 2R 5 -Si(OH)2-O-Si(OH)2-R 6 (N.H.R. 2 ) 2 In Formula II, R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group. 5 and R 6 are divalent organic groups which may be the same or different. The divalent organic group may be a linear or branched alkylene group. 5 and R 6 each of which contains two primary or secondary amino groups (R 1 HN or NHR 2 ) is bonded to R 5 and R 6In the formula (I), the two amino groups may be bonded to the same carbon atom or to different carbon atoms.

[0022] In Formulas I and II, R 1 and R 2 is, for example, an alkyl group which may have a substituent. The alkyl group may have 1 to 10 carbon atoms, 1 to 8 carbon atoms, or even 2 to 6 carbon atoms.

[0023] The content of aminosilane A in the anti-fogging liquid composition is, for example, 0.1 to 3.0%, 0.3 to 2.0%, or even 0.5 to 1.5%, based on the mass of the solid content. By appropriately adjusting the content of aminosilane A, it becomes easy to achieve both adhesion, water absorbency, and smoothness of the coating surface.

[0024] (Aminosilane B) Aminosilane B is a compound having an amino group and an alkoxy group. Aminosilane B may be an amino group-containing silane coupling agent. Aminosilane B may have a primary or secondary amino group as the amino group, and preferably has a primary amino group. Aminosilane B can reinforce the improvement of film adhesion due to the amino group. However, from the viewpoint of sufficiently suppressing yellowing, it is desirable that aminosilane B is not substantially contained.

[0025] Aminosilane B may include an aminoalkyltrialkoxysilane. Examples of aminoalkyltrialkoxysilanes include 3-aminopropyltrimethoxysilane (APTMS) and 3-aminopropyltriethoxysilane (APTES). Aminosilane B may be a silane coupling agent having two amino groups. An example of a silane coupling agent having two amino groups is N-2-(aminoethyl)-8-aminooctyltrimethoxysilane. A silane coupling agent having three or more amino groups can also be used as aminosilane B.

[0026] The content of aminosilane B in the anti-fogging liquid composition is, for example, 0 to 1.5%, 0 to 1.0%, or even 0 to 0.5%, based on the mass of the solids. Aminosilane B and other compounds having an alkoxy group are converted to solids in a state in which the alkoxy group has been hydrolyzed and dehydration-condensed. When aminosilane B is included, it is desirable that aminosilane A be contained in a proportion of 20% or more, 40% or more, or even more than 50%, and in some cases 70% or more, based on the mass of the solids, relative to the total amount of aminosilane A and aminosilane B.

[0027] (Epoxy Group-Containing Compound) The epoxy group-containing compound is an organic compound having an epoxy group. The epoxy group may be a part of a glycidyl group.

[0028] An example of an epoxy group-containing compound is an epoxy-containing silane coupling agent. The epoxy-containing silane coupling agent may be a glycidoxyalkyltrialkoxysilane. Examples of glycidoxyalkyltrialkoxysilanes include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane (GPTMS), and 3-glycidoxypropyltriethoxysilane. In the epoxy-containing silane coupling agent, the epoxy group reacts with the amino group, thereby preventing the amino group from reacting with the main chain of the polyvinyl acetal. Meanwhile, the alkoxy group is hydrolyzed to form a silanol group, which may result in the formation of a crosslinked structure or improved adhesion to the substrate.

[0029] The content of the epoxy-containing silane coupling agent in the anti-fogging liquid composition is, for example, 0 to 3.0%, 0.3 to 2.0%, or even 0.5 to 1.0% by mass of the solid content. By appropriately adjusting the content of the epoxy-containing silane coupling agent, it becomes easy to achieve both adhesion, water absorbency, and smoothness of the coating surface.

[0030] Another example of the epoxy group-containing compound is a polymer having an epoxy group (epoxy-containing polymer). The epoxy-containing polymer may not have a silicon atom. The epoxy-containing polymer may have two or more epoxy groups. The epoxy-containing polymer may be a linear polymer having epoxy groups at both ends. The epoxy-containing polymer is a component that can contribute to sufficient suppression of yellowing.

[0031] The content of the epoxy-containing polymer in the anti-fogging liquid composition is, for example, 0 to 1.0%, or even 0 to 0.5%, based on the mass of the solid content. By appropriately adjusting the content of the epoxy-containing polymer, it becomes easy to sufficiently suppress yellowing while suppressing a decrease in the abrasion resistance of the film.

[0032] (Silicon Tetraalkoxide) Silicon tetraalkoxide is a compound in which four alkoxy groups are bonded to a silicon atom. Examples of silicon tetraalkoxide include silicon tetramethoxide, silicon tetraethoxide (TEOS), and silicon tetraisopropoxide.

[0033] In anti-fogging liquid compositions, the incorporation of a silane coupling agent having an amino group, an epoxy group, or the like has been prioritized over silicon tetraalkoxide. For example, the anti-fogging liquid composition disclosed in Patent Document 1 does not contain silicon tetraalkoxide. However, silicon tetraalkoxide can contribute to improving the surface hardness and abrasion resistance of the anti-fogging film. In particular, this embodiment provides a film that suppresses yellowing even under high temperature and high humidity conditions and is suitable for use in humid environments. Therefore, the incorporation of silicon tetraalkoxide, which can compensate for the surface hardness that tends to decrease in humid atmospheres, is of great significance. However, silicon tetraalkoxide may not be substantially present depending on the required properties.

[0034] The content of silicon tetraalkoxide in the anti-fogging liquid composition is, for example, 0 to 1.0%, or even 0 to 0.5%, based on the mass of the solid content. By appropriately adjusting the content of silicon alkoxide, it becomes easy to prevent a decrease in water absorption while improving the abrasion resistance of the film.

[0035] (Polyether-modified siloxane) Polyether-modified siloxane is a compound having a polyether chain as at least one selected from a molecular chain bonded to the end of a siloxane main chain and a molecular chain bonded as a side chain to the siloxane main chain. Siloxane is a compound having a siloxane bond (Si—O—Si) as a skeleton. The constituent unit of the polyether chain is not particularly limited, but examples include ethylene oxide and propylene oxide. The polyether chain may contain only one type of constituent unit, or may contain two or more types of constituent units.

[0036] The polyether-modified siloxane can maintain the hydrophilicity of the film surface and complement the water absorption of the polyvinyl acetal to improve the anti-fogging properties. However, when the surface hardness of the film is important, the polyether-modified siloxane may not be substantially contained.

[0037] The content of the polyether-modified siloxane in the anti-fogging liquid composition is, for example, 0 to 2.0%, or even 0 to 1.0%, based on the mass of the solid content. By appropriately adjusting the content of the polyether-modified siloxane, it becomes easy to make the surface of the film hydrophilic while preventing a decrease in the surface hardness and abrasion resistance of the film and further preventing whitening of the film.

[0038] ((Meth)acrylic acid ester) The (meth)acrylic acid ester is an acrylic acid ester or a methacrylic acid ester, and may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate. The (meth)acrylic acid ester may be, for example, a di(meth)acrylate or a tri(meth)acrylate, particularly a diacrylate. The (meth)acrylic acid ester can exhibit the function of improving the adhesion of the film.

[0039] The (meth)acrylic acid ester may be a di(meth)acrylate having the structure shown in Formula III: 7 H=CHC(=O)OR 9 -OC(=O)CH=CR 8 H In Formula III, R 7 and R 8are each independently a methyl group or a hydrogen atom, and R 9 is a divalent organic group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms.

[0040] The content of the (meth)acrylic acid ester in the antifogging liquid composition is, for example, 0 to 2.0%, and preferably 0 to 1.0%, based on the mass of the solid content.

[0041] (Other Solid Contents) The antifogging liquid composition may further contain silica microparticles to improve abrasion resistance. The content of silica microparticles may be, for example, 1.0% or less, or even 0.5% or less, based on the mass of the solid content. However, silica microparticles may not be substantially contained. The antifogging liquid composition may also contain other components that do not fall under the category of silica microparticles or the above-mentioned components, such as a surface conditioner (leveling agent), an ultraviolet absorber, an infrared absorber, or a light stabilizer. The content of other components may be, for example, 0.5% or less, or even 0.1% or less, based on the mass of the solid content.

[0042] (Hydrolysis Catalyst) The antifogging liquid composition may further contain an acid catalyst as a hydrolysis catalyst for alkoxy groups, etc. The acid catalyst is preferably an inorganic acid such as hydrochloric acid or nitric acid. Since an alkali catalyst may contribute to the decomposition reaction of polyvinyl acetal, the use of an acid catalyst is suitable for the liquid composition of this embodiment.

[0043] (Solvent) As the solvent for the anti-fogging liquid composition, for example, water and a polar organic solvent can be used. The polar organic solvent may include an alcohol-based solvent. Examples of polar organic solvents are diols, particularly diols having 2 to 8 carbon atoms, and more preferably 2 to 6 carbon atoms. Examples of diols include ethylene glycol, diethylene glycol, propylene glycol (PG), dipropylene glycol, and butanediol.

[0044] (Film Formation) Formation of an anti-fogging film using an anti-fogging liquid composition can be carried out according to conventional methods. The anti-fogging liquid composition is applied to a substrate by various coating methods, such as spin coating, flow coating, spray coating, curtain coating, slit coating, etc., and then heated to be fixed on the substrate. An example of the heating temperature is 80 to 250°C, or preferably 100 to 200°C, and an example of the heating time is 1 to 40 minutes, or preferably 5 to 30 minutes. The coating liquid may be diluted as appropriate depending on the film formation method.

[0045] [Article with Anti-Fog Film] In one embodiment of the present invention, as shown in Figure 1, an article with an anti-fogging film 10 comprises a substrate 1 and an anti-fogging film 2 on the substrate. The surface of the anti-fogging film is exposed. The anti-fogging film may be formed directly on the substrate, or may be formed on the substrate via an undercoat film. The anti-fogging film can be formed using the anti-fogging liquid composition described above.

[0046] (Substrate) The substrate is not limited, but a transparent substrate is suitable. Examples of the substrate include a glass substrate and a resin substrate. These substrates may be flat or may have a shape other than a flat plate, and may be processed. Examples of processing for glass substrates include film formation for use as a mirror, lamination or strengthening for use in showcases, vehicles, etc., and molding processes such as bending. The substrate may be a substrate with an adhesive layer having an adhesive layer on the back surface opposite to the surface on which the anti-fogging film is formed. A resin substrate is suitable as a substrate on which an adhesive layer is formed.

[0047] (Anti-fogging film) The anti-fogging film may contain the solid components described above for the anti-fogging liquid composition or their reaction products. The reaction products are, for example, products of the reaction of amino groups and silanol groups contained in aminosilane A with other functional groups. The anti-fogging film contains at least polyvinyl acetal, and nitrogen atoms and silicon atoms derived from aminosilane A. The anti-fogging film may contain each of the components described above for the anti-fogging liquid composition or their reaction products. The content of each component in the anti-fogging film is the ratio of that solid component to the total solid component of the anti-fogging liquid composition.

[0048] The polyvinyl acetal content in the anti-fogging film is, by mass (the same applies hereinafter in this paragraph), for example, 20 to 90%, 30 to 80%, or even 35 to 75%. The aminosilane A content in the anti-fogging film is, for example, 0.5 to 40.0%, or even 5.0 to 25.0%. The aminosilane B content in the anti-fogging film is, for example, 0 to 10.0%, or even 1.0 to 8.0%. The epoxy-containing silane coupling agent content in the anti-fogging film is, for example, 0 to 40.0%, or even 5.0 to 25.0%. The epoxy-containing polymer content in the anti-fogging film is, for example, 0 to 15.0%, or even 1.0 to 8.0%. The silicon tetraalkoxide content in the anti-fogging film is, for example, 0 to 10%, or even 0.5 to 5.0%. The content of the polyether-modified siloxane in the anti-fogging film is, for example, 0 to 25.0%, or preferably 0.5 to 20.0%. The content of the (meth)acrylic acid ester in the anti-fogging film is, for example, 0 to 30.0%, or preferably 5.0 to 25.0%.

[0049] The thickness of the anti-fogging film is not particularly limited and may be adjusted appropriately depending on the use of the article, but is, for example, from 500 nm to 20 μm, and further from 1 μm to 10 μm.

[0050] In one embodiment of the present invention, the anti-fogging film-equipped article is one in which yellowing that progresses under high temperature and high humidity conditions is suppressed. According to the studies of the present inventors, the degree of yellowing of a film containing polyvinyl acetal can be evaluated using a change in light transmittance at a wavelength of 380 nm as an index to obtain appropriate results.

[0051] The anti-fog film-equipped article may have a change in light transmittance at a wavelength of 380 nm of 4% or less before and after a test in which it is kept in an air atmosphere at a temperature of 85°C and a relative humidity of 85% (85°C, 85RH atmosphere) for 250 hours.The anti-fog film-equipped article may have the characteristic that the change in light transmittance at the same wavelength before and after a test in which it is kept in an 85°C, 85RH atmosphere for 1,000 hours is 7% or less, 6% or less, 5% or less, 4.5% or less, 3% or less, 2% or less, or in some cases 1% or less.

[0052] The degree of yellowing of an article with an anti-fog film can also be evaluated by converting the film thickness of the anti-fog film into a predetermined film thickness. The article with an anti-fog film can have a characteristic in which the change in light transmittance at a wavelength of 380 nm before and after a test in which the article is kept in an atmosphere of 85°C and 85RH for 1000 hours is 4% or less, 5% or less, 3% or less, 2% or less, 1% or less, or in some cases 0.5% or less, converted into a film thickness of 1 μm.

[0053] The change in transmittance of the anti-fogging film can be converted into film thickness (equivalent to 1 μm) as follows: ΔT=(T1-T2) / D, where T1 is the transmittance at a wavelength of 380 nm before the high-temperature, high-humidity test, T2 is the transmittance at a wavelength of 380 nm after the high-temperature, high-humidity test, and D is the film thickness (unit: μm).

[0054] The surface hardness of the anti-fogging film in an anti-fogging film-equipped article, expressed in pencil hardness, can be H or higher, and in some cases 4H or higher. When a humid environment, as described below, is applied, the surface hardness of the anti-fogging film in an anti-fogging film-equipped article, expressed in pencil hardness, can be 2B or higher, and in some cases B or higher. The "or higher" pencil hardness refers to that hardness or a higher hardness, and is not based on the magnitude of the number. For example, "2B or higher" includes "B" as well as "HB" and the like. Pencil hardness can be evaluated in accordance with Japanese Industrial Standard JIS K5600-5-4:1999.

[0055] The article with the anti-fogging film can be used for various applications requiring an anti-fogging function, including, but not limited to, a mirror, a showcase door, a refrigerator door, a freezer door, a vehicle glass, an eyeglass lens, a cover glass, an optical glass, a resin film, and the like.

[0056] As described above, the present invention provides an anti-fogging liquid composition and an anti-fogging film in the following forms: (First form) An anti-fogging liquid composition comprising: polyvinyl acetal; and aminosilane A having an amino group and a silanol group but no alkoxy group.

[0057] (Second embodiment) The anti-fogging liquid composition of the first embodiment, wherein the amino group is a primary amino group.

[0058] (Third aspect) The anti-fogging liquid composition according to the first or second aspect, wherein the aminosilane A has two primary amino groups.

[0059] (Fourth aspect) The antifogging liquid composition according to any one of the first to third aspects, which is substantially free of aminosilane B having an amino group and an alkoxy group.

[0060] (Fifth aspect) The antifogging liquid composition according to any one of the first to fourth aspects, further comprising an epoxy group-containing compound.

[0061] (Sixth aspect) The anti-fogging liquid composition of the fifth aspect, wherein the epoxy group-containing compound has two or more epoxy groups.

[0062] (Seventh aspect) The antifogging liquid composition according to the fifth or sixth aspect, wherein the epoxy group-containing compound includes a polymer having an epoxy group.

[0063] (Eighth aspect) The anti-fogging liquid composition according to any one of the first to seventh aspects, further comprising a polyether-modified siloxane.

[0064] (9th aspect) The antifogging liquid composition according to any one of the 1st to 8th aspects, further comprising silicon tetraalkoxide.

[0065] (10th aspect) The antifogging liquid composition according to any one of the first to ninth aspects, further comprising an acid catalyst as a hydrolysis catalyst.

[0066] (11th embodiment) The anti-fogging liquid composition according to any one of the first to tenth embodiments, wherein the polyvinyl acetal has a degree of acetalization of 2 to 40 mol%.

[0067] (Twelfth form) An anti-fogging film-equipped article comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the anti-fogging film is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1000 hours is 7% or less.

[0068] (13th form) An anti-fogging film-equipped article comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and a change in light transmittance at a wavelength of 380 nm before and after a test in which the anti-fogging film is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1000 hours is 4% or less, expressed as a value converted to a film thickness of 1 μm for the anti-fogging film.

[0069] Hereinafter, the embodiments of the present invention will be described in more detail with reference to Examples and Comparative Examples. First, the methods for evaluating samples will be described.

[0070] (Evaluation of Yellowing) Each sample was kept in an atmosphere of 85°C and 85% relative humidity for a predetermined time (24 hours, 250 hours, or 1000 hours), and the degree of yellowing of the anti-fogging film was visually confirmed and evaluated based on the following criteria: A: No change B: Slight yellowing C: Slight yellowing D: Yellowing

[0071] (Anti-fogging properties) The following tests were performed on each sample before and after it was kept in an atmosphere of 85°C and 85% relative humidity for 1000 hours. Water at 35°C was placed inside a 250cc Erlenmeyer flask with an opening diameter of 36 mm. The sample was placed in the opening of the Erlenmeyer flask with the surface on which the anti-fogging film was formed facing the Erlenmeyer flask, and water vapor was supplied to the anti-fogging film. The temperature of the water inside the Erlenmeyer flask was maintained at 35±1°C, and the distance between the anti-fogging film and the water surface was 50 mm. The degree of fogging of the film was visually observed 20 seconds after the glass with the anti-fogging film was placed in the opening of the Erlenmeyer flask, and evaluated based on the following criteria. For glass substrates without an anti-fogging film, fogging was observed over the entire surface within 10 to 15 seconds. A: No fogging was observed. B: Fogging was observed on a portion of the film surface. C: Fogging was observed over the entire film surface.

[0072] (Abrasion resistance) A cellulose long fiber nonwoven fabric ("Bencotto" manufactured by Asahi Kasei) containing 0.50 ml of an alcoholic solvent mainly composed of purified water or ethanol ("Neoethanol P-7" manufactured by Taishin Chemical) was pressed against the surface of the anti-fogging film of each sample with a load of 100 g and moved back and forth 10 times to check for any changes in the anti-fogging film, and evaluated based on the following: A: No scratches B: Slight scratches C: Slight scratches D: Multiple small scratches E: Film peeling

[0073] (Pencil hardness) This was carried out in accordance with Japanese Industrial Standard JIS K5600-5-4:1999. The pencil used was a pencil for scratch hardness testing specified by the Japan Paint Inspection Association, a general incorporated association. The pencil hardness was measured in both the dry and wet states as follows: Dry state (the anti-fogging film-coated glass was left to stand for at least one hour in a room at 20-28°C and a relative humidity of 25-50%, and then the pencil hardness test was carried out) Wet state (the anti-fogging film-coated glass was held over steam from hot water at 100°C for at least 10 seconds, and the pencil hardness test was carried out immediately when the anti-fogging film surface became cloudy, or water droplets or a water film formed) AAA: 6H AA: 5H-6H A + :5H A:4H~5H A - :H~3H B:B~F C:2B~B D:4B~3B E: Less than 4B

[0074] (Change in Transmittance ΔT) Each sample was kept in an atmosphere of 85°C and 85% relative humidity for a predetermined time (250 hours or 1000 hours), and the light transmittance at a wavelength of 380 nm was measured. The difference ΔT from the light transmittance at the same wavelength before and after the test was measured. In addition, ΔT was calculated when converted to a film thickness of 1 μm.

[0075] Next, the preparation of the samples will be described. Anti-fogging liquid compositions were prepared so that the solid content concentration was the value shown in Table 1. The solvents used are shown in Table 2. However, for raw materials containing alkoxy groups, the solid content concentration was calculated based on the state in which the alkoxy groups were hydrolyzed and further dehydration-condensed. For example, -Si(OR)3 moieties, -SiO 3 / 2 The raw materials used are as follows:

[0076] Polyvinyl acetal: "S-LEC KX-5" manufactured by Sekisui Chemical Co., Ltd. (solid content 8% by mass, degree of acetalization 9% by mole, contains an acetal structure derived from benzaldehyde) Aminosilane A: "KBP-64" manufactured by Shin-Etsu Chemical Co., Ltd. (NH2CH2CH(NH2)Si(OH)2OSi(OH)2CH(NH2)CH2NH2) Aminosilane A: "KBP-90" manufactured by Shin-Etsu Chemical Co., Ltd. (NH2RSi(OH)2OSi(OH)2RNH2; R is a divalent organic group) Aminosilane A: "DynaSylane 2627" manufactured by Evonik (X-RSi(OH)2OSi(OH)2R-X; X is an organic group having a secondary amino group, R is a divalent organic group) Aminosilane B: Shin-Etsu Chemical Co., Ltd.'s "KBE-903" (3-aminopropyltriethoxysilane) Aminosilane B: Shin-Etsu Chemical Co., Ltd.'s "KBM-6803" (N-2-(aminoethyl)-8-aminooctyltrimethoxysilane) Epoxy-containing polymer: Kyoeisha Chemical Co., Ltd.'s "Epolite 400E" (EP-CHO(CHCHO) n CH2-EP; EP is an epoxy group, n is approximately 9) Silicon tetraalkoxide: ("KBE-04" manufactured by Shin-Etsu Chemical Co., Ltd.) Polyether-modified siloxane: "Silface SAG503A" (polyether-modified dimethyl siloxane) manufactured by Nissin Chemical Industry Co., Ltd. (meth)acrylic acid ester: "Light Acrylate NP-A" (neopentyl glycol diacrylate) manufactured by Kyoeisha Chemical Co., Ltd. Surface conditioner: "KP-341" manufactured by Shin-Etsu Chemical Co., Ltd. Acid catalyst: acetic acid or hydrochloric acid, nitric acid Solvent: alcohol-based solvent ("Neoethanol P-7" manufactured by Taishin Chemical), propylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 1,3-butanediol (manufactured by Sigma-Aldrich), propylene glycol monomethyl ether (PGME, manufactured by Lyondell Japan)

[0077] Next, the prepared anti-fogging liquid composition was spin-coated onto a 1.1 mm thick glass plate. Float glass was used as the glass plate. The glass plate coated with the liquid composition was heated at 140°C for 30 minutes to form an anti-fogging film. The film thickness and evaluation results of the anti-fogging film for each sample are shown in Table 3. However, for Samples 15 to 21, the anti-fogging liquid composition was diluted four-fold with a diluent (a mixed solvent of water, propylene glycol, PGME, etc.), and then applied to a 3.0 mm thick float glass plate by spray coating, followed by heating at 175°C for 5 minutes.

[0078] As shown in Tables 1 and 3, the addition of aminosilane A suppressed yellowing of the anti-fogging film. The anti-fogging films (samples 9 and 10) obtained from the liquid compositions containing aminosilane B together with aminosilane A showed some yellowing, although not as much as the anti-fogging films (samples 22 and 23) containing only aminosilane B as the aminosilane. Yellowing was particularly suppressed in the anti-fogging films (samples 11 and 12) obtained from the liquid compositions to which an epoxy-containing polymer was added.

[0079] In the anti-fogging film (Sample 13) using aminosilane A having a secondary amino group, the adhesion of the film was significantly reduced when alcohol was used. From the viewpoint of maintaining the adhesion of the film, the use of aminosilane A having a primary amino group is suitable. In the anti-fogging films (Samples 17 to 20) obtained from the liquid composition to which silicon alkoxide was added, the adhesion of the film improved, and in particular the pencil hardness increased. The adhesion of the film was also improved in the anti-fogging film (Sample 21) obtained from the liquid composition to which a (meth)acrylic acid ester was added.

[0080]

[0081]

[0082]

Claims

1. An anti-fogging liquid composition comprising: polyvinyl acetal; and aminosilane A having an amino group and a silanol group but no alkoxy group.

2. The anti-fogging liquid composition according to claim 1, wherein the amino group is a primary amino group.

3. The anti-fogging liquid composition according to claim 1, wherein said aminosilane A has two primary amino groups.

4. The anti-fogging liquid composition according to claim 1, which is substantially free of aminosilane B having an amino group and an alkoxy group.

5. The anti-fogging liquid composition according to claim 1, further comprising an epoxy group-containing compound.

6. The anti-fogging liquid composition according to claim 5, wherein the epoxy group-containing compound has two or more epoxy groups.

7. The anti-fogging liquid composition according to claim 5, wherein the epoxy group-containing compound comprises a polymer having an epoxy group.

8. The anti-fogging liquid composition according to claim 1, further comprising a polyether-modified siloxane.

9. The anti-fogging liquid composition according to claim 1, further comprising a silicon tetraalkoxide.

10. The anti-fogging liquid composition according to claim 1, further comprising an acid catalyst as a hydrolysis catalyst.

11. The anti-fogging liquid composition according to claim 1, wherein the degree of acetalization of the polyvinyl acetal is 2 to 40 mol %.

12. An article with an anti-fogging film, comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the article is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1,000 hours is 7% or less.

13. An anti-fogging film-attached article comprising a substrate and an anti-fogging film on the substrate, wherein the anti-fogging film contains polyvinyl acetal, silicon atoms, and nitrogen atoms, and the change in light transmittance at a wavelength of 380 nm before and after a test in which the anti-fogging film is kept in an atmospheric atmosphere at a temperature of 85°C and a relative humidity of 85% for 1,000 hours is 4% or less, expressed as a value converted to a film thickness of 1 μm for the anti-fogging film.

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