Silicone compounds, their hydrolysis condensates, and coating compositions

Abstract

A coating composition excellent in water resistance, which imparts hydrophilicity and antifogging properties, comprising an organosilicon compound having a betaine structure represented by the following formula (1). (In the formula, R 1 and R 2 each independently represent an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, R 3 represents a divalent organic group containing an aromatic ring and having 6 to 14 carbon atoms, R 4 and R 5 each independently represent an alkyl group having 1 to 6 carbon atoms, X represents an alkylene group having 1 to 10 carbon atoms, Y represents COO ‑ , SO3 ‑ , or PO4 ‑ , and n is an integer of 1 to 3.)#imgabs0#

Description

Technical Field

[0001] The present invention relates to an organosilicon compound, a hydrolysis condensate thereof, and a coating composition containing the organosilicon compound. Background Art

[0002] In recent years, there has been an increasing demand for improvement in the clouding of substrates formed of inorganic materials such as glass and organic materials such as plastic.

[0003] Improvement of substrate fogging is generally achieved by coating the substrate surface with a hydrophilic coating. For example, Patent Document 1 discloses a coating composition primarily composed of an organosilicon compound having a sulfobetaine structure in which the nitrogen atom in the nitrogen-containing heterocyclic structure has a positive charge, as a coating agent capable of imparting hydrophilicity to a substrate.

[0004] However, the coating film produced from the coating composition of Patent Document 1 has insufficient water resistance. When in contact with water, the surface properties such as the hydrophilicity and anti-fogging properties mentioned above may deteriorate. Improvement of this problem is desired.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-48966 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an organosilicon compound for imparting hydrophilicity and anti-fogging properties to a coating composition having excellent water resistance.

[0010] Means for solving problems

[0011] The present inventors conducted intensive research to address the above-mentioned issues and, as a result, discovered that a specific organosilicon compound having a betaine structure can provide a coating composition that exhibits excellent water resistance and imparts sustained hydrophilicity and anti-fogging properties to substrates made of inorganic materials such as glass and organic materials such as plastics. This led to the completion of the present invention.

[0012] That is, the present invention provides:

[0013] 1. An organosilicon compound containing a betaine structure represented by the following formula (1):

[0014] [Chemistry 1]

[0015]

[0016] Where R 1 and R 2Each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, R 3 represents a divalent organic group having 6 to 14 carbon atoms and containing an aromatic ring, R 4 and R 5 each independently represents an alkyl group having 1 to 6 carbon atoms, X represents an alkylene group having 1 to 10 carbon atoms, and Y represents COO - , SO3 - , or PO4 - , and n is an integer of 1 to 3;

[0017] 2. The organosilicon compound according to 1, wherein the R 3 represents a phenylene group;

[0018] 3. A hydrolytic condensate of the organosilicon compound according to 1 or 2;

[0019] 4. A coating composition comprising one or more of the organosilicon compound according to 1 and its hydrolytic condensate;

[0020] 5. The coating composition according to 4, further comprising an inorganic oxide.

[0021] Effects of the Invention

[0022] The organosilicon compound of the present invention provides a coating composition having excellent water resistance and capable of imparting persistent hydrophilicity and antifogging properties to substrates such as glass. Detailed Description of the Invention

[0023] The present invention will be specifically described below.

[0024] The organosilicon compound of the present invention is represented by the following formula (1).

[0025] [Chemical Formula 2]

[0026]

[0027] In formula (1), R 1 each independently represents an alkyl group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms.

[0028] R 1 The alkyl group can be linear, branched, or cyclic. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, etc.

[0029] As specific examples of the aryl group of R 1 , phenyl, tolyl, etc. can be cited.

[0030] Among these, R 1 is preferably an alkyl group having 1 to 3 carbon atoms, more preferably methyl or ethyl.

[0031] R 2 each independently represents an alkyl group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms. Specific examples of these alkyl and aryl groups include the same groups as those exemplified for R 1 above, and among them, methyl is preferred.

[0032] R 3 represents a divalent organic group containing an aromatic ring and having 6 to 14 carbon atoms, preferably a divalent organic group containing an aromatic hydrocarbon ring, more preferably a divalent organic group containing a benzene ring or a naphthalene ring.

[0033] As specific examples of R 3 , groups represented by the following formulas can be cited, but are not limited to these. Among them, the phenylene group represented by formula (3) is preferred, and 1,4-phenylene is more preferred.

[0034] [Chemical formula 3]

[0035]

[0036] R 4 and R 5 each independently represent an alkyl group having 1 to 6 carbon atoms.

[0037] R 4 and R 5 The alkyl groups can be linear, branched, or cyclic. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, etc.

[0038] Among these, R 4 and R 5 are both preferably methyl or ethyl, and from the viewpoints of availability of raw materials and environmental load during use, both are more preferably methyl.

[0039] X represents an alkylene group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms.

[0040] The alkylene group of X can be linear, branched, or cyclic. Specific examples thereof include methylene, ethylene, trimethylene, propylene, tetramethylene, pentamethylene, hexamethylene, cyclohexylene, etc.

[0041] Among these, X is preferably methylene, ethylene, or trimethylene, and more preferably trimethylene.

[0042] Y represents COO - , SO3 - , or, PO4 - , from the viewpoint of the durability of the obtained coating film, SO3 is preferred - .

[0043] n is an integer from 1 to 3, preferably 3

[0044] As the organosilicon compound of the present invention, the one represented by the following formula (2) is particularly preferred

[0045] [Chemical formula 4]

[0046]

[0047] (In the formula, R 1 , R 2 , R 4 , R 5 , X, Y and n represent the same meanings as described above.)

[0048] Specific examples of the organosilicon compound of the present invention are exemplified below, but are not limited to these

[0049] [Chemical formula 5]

[0050]

[0051] (In the formula, Me means methyl, and Et means ethyl. The same applies hereinafter.)

[0052] The organosilicon compound represented by the above formula (1) can be manufactured by a known method. For example, a compound with a sulfonic acid terminal can be manufactured by reacting a nitrogen-containing organosilicon compound represented by the following formula (A) with a sultone ring compound represented by the following formula (B) in an air atmosphere or an inert gas atmosphere such as nitrogen

[0053] [Chemical formula 6]

[0054]

[0055] (In the formula, R 1 , R 2 , R 3 , R 4 , R 5 , X and n represent the same meanings as described above.)

[0056] Specific examples of the compound represented by the above formula (A) are exemplified below, but are not limited to these

[0057] [Chemical formula 7]

[0058]

[0059] As specific examples of the sultone ring compound represented by the above formula (B), 1,3-propane sultone, 1,4-butane sultone, 2,4-butane sultone, 1,5-pentane sultone, 2,4-pentane sultone, 1,4-hexane sultone, 4,6-heptane sultone, etc. can be cited.

[0060] Among these, 1,3-propane sultone, 1,4-butane sultone, and 2,4-butane sultone are preferred, 1,3-propane sultone and 1,4-butane sultone are more preferred, and 1,3-propane sultone is further preferred.

[0061] The above reaction can also be carried out without a solvent, and if necessary, it can be carried out in an alcohol solvent such as methanol or ethanol that does not hinder the reaction.

[0062] As the reaction temperature, 0°C to the boiling point of each solvent is preferred, and 0 to 130°C is more preferred.

[0063] The reaction time is preferably 1 to 150 hours, and more preferably 5 to 100 hours.

[0064] Regarding the usage ratio of the organosilicon compound represented by the above formula (A) and the sultone ring compound represented by the above formula (B) during the reaction, relative to 1 mole of the sultone ring compound (B), 0.7 to 1.3 moles of the organosilicon compound (A) is preferred.

[0065] The coating composition of the present invention contains one or more of the organosilicon compounds represented by the above formula (1) and their hydrolysis condensates.

[0066] In particular, the organosilicon compound of the present invention represented by the above formula (1) can further improve the durability of the obtained film by subjecting it to hydrolysis condensation. When carrying out hydrolysis condensation, other organosilicon compounds can be added for co-hydrolysis condensation within the range that does not impair the object of the present invention.

[0067] As specific examples of other organosilicon compounds, methyltrimethoxysilane, methyltripropoxysilane, methyltriacetoxysilane, methyltributoxysilane, methyltripentyloxysilane, methyltriphenoxysilane, methyltribenzyloxysilane, methyltriphenethoxysilane, glycidyloxymethyltrimethoxysilane, glycidyloxymethyltriethoxysilane, α-glycidyloxyethyltrimethoxysilane, α-glycidyloxyethyltriethoxysilane, β-glycidyloxyethyltrimethoxysilane, β-glycidyloxyethyltriethoxysilane, α-glycidyloxypropyltrimethoxysilane, α-glycidyloxypropyltriethoxysilane, β-glycidyloxypropyltrimethoxysilane, β-glycidyloxypropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, γ-glycidyloxypropyltripropoxysilane, γ-glycidyloxypropyltributoxysilane, γ-glycidyloxypropyltriphenoxysilane, α-glycidyloxybutyltrimethoxysilane, α-glycidyloxybutyltriethoxysilane, β-glycidyloxybutyltriethoxysilane, γ-glycidyloxybutyltrimethoxysilane, γ-glycidyloxybutyltriethoxysilane, δ-glycidyloxybutyltrimethoxysilane, δ-glycidyloxybutyltriethoxysilane, (3,4-epoxycyclohexyl)methyltrimethoxysilane, (3,4-epoxycyclohexyl)methyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltripropoxysilane, β-(3,4-epoxycyclohexyl)ethyltributoxysilane, β-(3,4-epoxycyclohexyl)ethyltriphenoxysilane, γ-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ-(3,4-epoxycyclohexyl)propyltriethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(3,4-(epoxycyclohexyl)butyltriethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylethyldimethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, β-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, N-(β-aminoethyl)γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)γ-aminopropyltriethoxysilane, N-(β-aminoethyl)γ-aminopropylmethyldiethoxysilane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptomethyldiethoxysilane, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltripropoxysilane, (R)-N-1-phenylethyl-N'-triethoxysilylpropylurea, (R)-N-1-phenylethyl-N'-trimethoxysilylpropylurea, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, bromopropyltriethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, etc. These can be used alone or in combination of two or more.

[0068] In hydrolysis and condensation, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid, etc.; bases such as ammonia, methylamine, ethylamine, etc.; metal salts of hydrochloric acid, sulfuric acid, nitric acid, etc. can be used as catalysts.

[0069] As solvents for the hydrolysis and condensation reaction, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, tert-butanol, pentanol, ethylene glycol, propylene glycol, 1,4-butanediol, etc.; ether solvents such as diethyl ether, tetrahydrofuran, dioxane, etc.; ketone solvents such as acetone, methyl ethyl ketone, etc.; aprotic solvents such as dimethyl sulfoxide, N,N-dimethylformamide, etc.; water; their mixed solvents, etc. can be cited. These solvents can be used singly or in combination of two or more.

[0070] Among these, alcohol solvents and water are preferred.

[0071] The reaction temperature of hydrolysis and condensation is preferably 0°C to the boiling point of the solvent, more preferably 0 to 120°C, and further preferably 5 to 80°C.

[0072] The reaction time is preferably 10 minutes to 80 hours, more preferably 30 minutes to 50 hours, and further preferably 30 minutes to 2 hours.

[0073] The coating composition of the present invention may further contain water, the above-mentioned other silicone compounds, alcohols such as methanol and ethanol, and other additives within the scope not detrimental to the object of the present invention.

[0074] As other additives, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid, etc.; bases such as ammonia, methylamine, ethylamine, etc.; inorganic oxides; leveling agents; surfactants, etc. can be cited.

[0075] In particular, starting from obtaining a hydrophilic film with high durability, the coating composition of the present invention preferably contains an inorganic oxide.

[0076] As the inorganic oxide, silica fine particles, alumina fine particles, titanium dioxide fine particles, magnesium fluoride fine particles, etc. are preferred, and it is more preferred to use these as a colloidal solution.

[0077] In order to improve the coating film uniformity, the above-mentioned leveling agent and surfactant are contained, and they can be appropriately selected and used from known substances, and commercially available products that are easily available are preferably used.

[0078] The silicone compound represented by the above formula (1) contained in the coating composition of the present invention can react with the silanol groups on silica sol (for example, aqueous silica sol: Na + Stable type basic sol ST-30L, organosilica sol: organosilica sol IPA-ST manufactured by Nissan Chemical Industries, Ltd., etc., preferably ST-30L).

[0079] In this case, as specific examples and preferred examples of the solvent for the reaction, the same solvents as those exemplified in the above hydrolysis condensation reaction can be cited.

[0080] The reaction temperature is preferably from 0 °C to the boiling point of the solvent, more preferably from 0 to 120 °C, and further preferably from 5 to 80 °C.

[0081] The reaction time is preferably from 10 minutes to 80 hours, more preferably from 30 minutes to 50 hours, and further preferably from 30 minutes to 2 hours.

[0082] In the present invention, the solution obtained by the above method can be directly used as a coating composition, or, if necessary, the solution can be concentrated, or diluted by adding a solvent to the solution, or the solvent in the solution can be replaced with another solvent for use.

[0083] There is no particular limitation on the content of the organosilicon compound represented by the above formula (1) and its hydrolysis condensate contained in the coating composition of the present invention. From the viewpoint of hydrophilicity, it is preferably from 0.0001 to 50% by mass, more preferably from 0.001 to 40% by mass, based on the whole composition.

[0084] The coating composition of the present invention can further impart hydrophilicity by being applied to various substrates.

[0085] Specific examples of the material constituting the substrate include glass; synthetic resins {polymethyl methacrylate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, ABS resin, polycarbonate resin, polystyrene resin, epoxy resin, unsaturated polyester resin, melamine resin, diallyl phthalate resin, polyimide resin, polyurethane resin, nylon resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, fluororesins (polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polyvinylidene fluoride resin, perfluoroalkoxy fluororesin, tetrafluoroethylene-hexafluoropropylene copolymer resin, ethylene-tetrafluoroethylene copolymer resin, ethylene-chlorotrifluoroethylene copolymer resin, etc.); polybutadiene, polyisopropene, SBR, nitrile rubber, EPM, EPDM, epichlorohydrin rubber, chloroprene rubber, polysulfide, butyl rubber, etc.}; metals (iron, aluminum, stainless steel, titanium, copper, brass, their alloys, etc.); cellulose, cellulose derivatives, cellulose analogs (chitin, chitosan, porphyrin, etc.), natural fibers such as cotton, silk, and wool; regenerated fibers such as rayon; semi-synthetic fibers such as acetate; synthetic fibers such as vinylon, polyester, nylon, polyethylene, polypropylene, polyurethane, and polyaramide fibers; composite fibers of these fibers (such as polyester / cotton), etc. As its form, substrates, sheets, films, fibers, etc. can be cited.

[0086] The coating composition of the present invention is coated on a substrate, heated and dried as needed to form a coating film, and a hydrophilic coating film can be obtained.

[0087] As the coating method, known methods can be used. For example, bar coating, dip coating, spin coating, spray coating, flow coating, brush coating, gravure coating, roll transfer printing, knife coating, air knife coating, slot coating, screen coating, inkjet printing, aniline printing, etc. can be used. Among these, bar coating is preferred.

[0088] Examples

[0089] Examples and comparative examples are listed below to specifically illustrate the present invention, but the present invention is not limited by the following examples.

[0090] [1] Preparation of organosilicon compounds

[0091] [Example 1-1] Preparation of organosilicon compound A-1

[0092] [Chemical formula 8]

[0093]

[0094] 1.69 g of trimethoxy-4-(N,N-dimethylamino)phenylsilane, 0.64 g of 1,3-propanesultone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 1.77 g of methanol were placed in a reactor and reacted at 25 °C for 24 hours. After the reaction, 4 g of a methanol solution of organosilicon compound A-1 (solid component concentration: 59% by mass) was obtained by filtration.

[0095] [Example 1-2] Preparation of organosilicon compound B-1

[0096] [Chemical formula 9]

[0097]

[0098] 2.83 g of trimethoxy-4-(N,N-dimethylbenzylamino)ethylene silane, 0.92 g of 1,3-propanesultone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.53 g of methanol were placed in a reactor and reacted at 25 °C for 24 hours. After the reaction, 6 g of a methanol solution of organosilicon compound B-1 (solid component concentration: 61% by mass) was obtained by filtration.

[0099] [Comparative Example 1-1] Organosilicon compound C-1

[0100] [Chemical formula 10]

[0101]

[0102] 6.22 g of trimethoxy-3-(N,N-dimethylamino)propylsilane, 2.76 g of 1,3-propanesultone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 7.58 g of methanol were placed in a reactor and reacted at 25°C for 24 hours. After the reaction, 16 g of a methanol solution of organosilicon compound C-1 (solid component concentration: 57% by mass) was obtained by filtration.

[0103] [Comparative Example 1-2] Organosilicon Compound D-1

[0104] [Chemical Formula 11]

[0105]

[0106] 2.30 g of trimethoxy-3-(imidazol-1-yl)propylsilane, 0.92 g of 1,3-propanesultone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.52 g of methanol were placed in a reactor and reacted at 25°C for 24 hours. After the reaction, 5 g of a methanol solution of organosilicon compound D-1 (solid component concentration: 58% by mass) was obtained by filtration.

[0107] [2] Preparation of Coating Composition

[0108] [Example 2-1]

[0109] 0.1356 g of the methanol solution of organosilicon compound A-1 obtained in Example 1-1, 0.0644 g of methanol, 0.004 g of ion-exchanged water, and 0.002 g of acetic acid were placed in a reactor and reacted at 25°C for 1 hour to obtain a brown transparent liquid (coating composition K1).

[0110] [Example 2-2]

[0111] 0.1316 g of the methanol solution of organosilicon compound B-1 obtained in Example 1-2, 0.0684 g of methanol, 0.004 g of ion-exchanged water, and 0.002 g of acetic acid were placed in a reactor and reacted at 25°C for 1 hour to obtain a brown transparent liquid (coating composition K2).

[0112] [Comparative Example 2-1]

[0113] 0.1413 g of the methanol solution of organosilicon compound C-1 obtained in Comparative Example 1-1, 0.0587 g of methanol, 0.004 g of ion-exchanged water, and 0.002 g of acetic acid were placed in a reactor and reacted at 25°C for 1 hour to obtain a colorless transparent liquid (coating composition L1).

[0114] [Comparative Example 2-2]

[0115] In a reactor, 0.1373 g of a methanol solution of the silicone compound D-1 obtained in Comparative Example 1-2, 0.0627 g of methanol, 0.004 g of ion-exchanged water, and 0.002 g of acetic acid were placed, and the reaction was carried out at 25 °C for 1 hour to obtain a colorless and transparent liquid (coating composition L2).

[0116] [Example 2-3]

[0117] In a reactor, 0.006 g of a solution obtained by diluting a methanol solution of the silicone compound A-1 obtained in Example 1-1 with methanol (solid content concentration: 15% by mass), + 0.006 g of a dispersion obtained by diluting a stable basic silica sol ST-30L (manufactured by Nissan Chemical Industries, Ltd.) with ion-exchanged water (solid content concentration: 15% by mass), and 0.002 g of a 25% aqueous acetic acid solution were placed, and the reaction was carried out at 25 °C for 1 hour to obtain a white liquid (coating composition K3).

[0118] [Example 2-4]

[0119] In a reactor, 0.006 g of a solution obtained by diluting a methanol solution of the silicone compound B-1 obtained in Example 1-2 with methanol (solid content concentration: 15% by mass), + 0.006 g of a dispersion obtained by diluting a stable basic silica sol ST-30L (manufactured by Nissan Chemical Industries, Ltd.) with ion-exchanged water (solid content concentration: 15% by mass), and 0.002 g of a 25% aqueous acetic acid solution were placed, and the reaction was carried out at 25 °C for 1 hour to obtain a white liquid (coating composition K4).

[0120] [Comparative Example 2-3]

[0121] In a reactor, 0.006 g of a solution obtained by diluting a methanol solution of the silicone compound C-1 obtained in Comparative Example 1-1 with methanol (solid content concentration: 15% by mass), + 0.006 g of a dispersion obtained by diluting a stable basic silica sol ST-30L (manufactured by Nissan Chemical Industries, Ltd.) with ion-exchanged water (solid content concentration: 15% by mass), and 0.002 g of a 25% aqueous acetic acid solution were placed, and the reaction was carried out at 25 °C for 1 hour to obtain a white liquid (coating composition L3).

[0122] [Comparative Example 2-4]

[0123] In a reactor, 0.006 g of a solution obtained by diluting a methanol solution of the silicone compound D-1 obtained in Comparative Example 1-2 with methanol (solid content concentration: 15% by mass), +A dispersion (solid component concentration: 15% by mass) of 0.006 g of the stable alkaline silica sol ST-30L (manufactured by Nissan Chemical Industries, Ltd.) diluted with ion-exchanged water and 0.002 g of a 25% aqueous acetic acid solution were reacted at 25°C for 1 hour to obtain a white liquid (coating composition L4).

[0124] [3] Preparation and Evaluation of Coating Films

[0125] [Examples 3-1 to 3-4, Comparative Examples 3-1 to 3-4]

[0126] The coating compositions K1 to K4 and L1 to L4 obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-4 were respectively coated on glass plates using a bar coater (No. 4), and then immediately dried at 80°C for 30 minutes to form films.

[0127] For each of the obtained films, the following tests were conducted. The results are shown in Table 1.

[0128] (1) Water Contact Angle

[0129] Using a contact angle measuring device (manufactured by Kyowa Interface Science Co., Ltd., automatic contact angle meter DM-701, droplet volume 2 μL, measurement interval 5000 ms, number of measurements 5 times), the contact angle (°) of ion-exchanged water was measured at 5 arbitrary locations on each of the above films, and the average value was calculated.

[0130] (2) Anti-Fogging Property

[0131] Exhaled breath was sprayed onto each of the above films. The case where the surface of the film fogged up was marked as ×, and the case where it did not fog up was marked as ○. Furthermore, when the film was placed 3 cm above the water surface in a warm water bath at 60°C, the case where the surface of the film did not fog up was marked as ◎, and the anti-fogging property (presence or absence of fogging caused by water vapor) was evaluated.

[0132] (3) Water Resistance

[0133] Each of the above films was immersed in tap water at 25°C for 5 minutes. Then, after sucking the water on the surface with a paper wiper, it was dried at 25°C for 10 minutes. Then, the above water contact angle measurement and anti-fogging property evaluation were conducted. Furthermore, each film was immersed in tap water at 25°C for 55 minutes. Then, after sucking the water on the surface with a paper wiper, it was dried at 25°C for 10 minutes. Then, the above water contact angle measurement and anti-fogging property evaluation were conducted.

[0134] [Table 1]

[0135]

[0136] As shown in Table 1, it can be seen that the films obtained in Examples 3-1 to 3-4 maintained excellent hydrophilicity and antifogging properties even after the water resistance tests (5-minute water immersion, 1-hour water immersion). In particular, it can be seen that the film of Example 3-3 has excellent durability.

[0137] On the other hand, it can be seen that the exhalation antifogging property of the films of Comparative Examples 3-1 to 3-4 disappeared after 1-hour water immersion, and the durability was poor.

Claims

1. An organosilicon compound containing a betaine structure represented by the following formula (1): [Chemical Formula 1] In the formula, R 1 and R 2 each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R 3 represents a divalent organic group having 6 to 14 carbon atoms and containing an aromatic ring, represented by any one of the following formulas: R 4 and R 5 each independently represents an alkyl group having 1 to 6 carbon atoms, X represents an alkylene group having 1 to 10 carbon atoms, Y represents COO - , SO3 - , or PO4 - , and n is an integer from 1 to 3.

2. The organosilicon compound according to claim 1, wherein, Said R 3 represents a phenylene group.

3. A hydrolytic condensate of the organosilicon compound according to claim 1 or 2.

4. A coating composition comprising one or more of the organosilicon compounds according to claim 1 and their hydrolytic condensates.

5. The coating composition according to claim 4, further comprising an inorganic oxide.

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