Reactive silicon group-containing organopolysiloxane and surface treatment agent

Abstract

To provide a reactive silicon group-containing organopolysiloxane capable of forming a film having excellent water repellency, water sliding properties, and durability.SOLUTION: A reactive silicon group-containing organopolysiloxane includes, per molecule thereof, one group represented by structural formula (1) and bonded to a silicon atom at the end of a linear organopolysiloxane. (In the formula, R1 and R2 each independently represent a hydrogen atom, a C1-C10 aliphatic saturated hydrocarbon group, or a C6-C10 aryl group; R3 each independently represent a C1-C10 aliphatic saturated hydrocarbon group or a C6-C10 aryl group; Z represents an oxygen atom, a C2-C12 alkylene group, or a C8-C12 alkylene arylene group; and a line with a wavy line represents a bond).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a reactive silicon group-containing organopolysiloxane and a surface treatment agent. More specifically, it relates to an organopolysiloxane having an organic silicon group capable of reacting to form a siloxane bond as a reactive silicon group, and a cured product containing the same.

Background Art

[0002] Conventionally, as a water-repellent treatment agent for glass, surface treatment agents containing fluoroalkylsilane or amino-modified polysiloxane have been proposed (see Patent Documents 1 to 6). Although the water-repellent film formed from these surface treatment agents is excellent in water repellency, the water slipperiness of water droplets on the film surface is insufficient. For example, when applied to the window glass of an automobile, in order to ensure good visibility during rainfall, improvement in water slipperiness is required.

[0003] Regarding this point, as a composition that provides a water-repellent coating film having both water repellency and water slipperiness, Patent Document 7 proposes a surface treatment agent containing a linear organopolysiloxane having a reactive group at one end and an alkoxy group-containing organic silicon compound. However, the water-repellent film formed from the surface treatment agent of Patent Document 7 is not sufficiently durable against impact and abrasion, and it is difficult to maintain water repellency.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a reactive silicon group-containing organopolysiloxane capable of forming a film excellent in water repellency, water slipperiness, and durability, and a surface treatment agent containing the same. [Means for Solving the Problems]

[0006] As a result of intensive studies to solve the above problems, the present inventor has found that a linear organopolysiloxane having a silyl group in which an organoxymethyl group and two organoxy groups are bonded as reactive silicon groups at the ends of the molecular chain segments gives a film excellent in water repellency, water slipperiness, and durability, and completed the present invention.

[0007] That is, the present invention is 1. A reactive silicon group-containing organopolysiloxane containing one group represented by the following structural formula (1) bonded to a silicon atom at the end of a linear organopolysiloxane in one molecule, [Chemical Formula] (In the formula, R 1 and R 2 each independently represent a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R 3 each independently represent an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, Z represents an oxygen atom, an alkylene group having 2 to 12 carbon atoms, or an alkylene arylene group having 8 to 12 carbon atoms, and the wavy line represents a bond.) 2. A reactive silicon group-containing organopolysiloxane represented by the following formula (2): [Chemical formula] (In the formula, R 4 each independently represents an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R 5 each independently represents a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, R 1 , R 2 , R 3 and Z represent the same meaning as described above, m is an integer of 0 to 2, and n is an integer of 1 to 100.) 3. A surface treatment agent containing one or two reactive silicon group-containing organopolysiloxanes, a hydrolysis condensate thereof, or both. 4. Further, the surface treatment agent of 3 containing an acid catalyst. 5. An article to which the surface treatment agent of 3 is attached. To provide. [Advantages of the Invention]

[0008] The reactive silicon group-containing organopolysiloxane of the present invention can form a film excellent in water repellency, water lubricity and durability, and thus can be suitably used as a surface treatment agent for use in water repellent treatment of fiber products, glass of transportation machines and vehicle bodies. [Modes for Carrying Out the Invention]

[0009] Hereinafter, the present invention will be specifically described. The reactive silicon group-containing organopolysiloxane of the present invention is a reactive silicon group-containing organopolysiloxane containing one group represented by the following structural formula (1) bonded to a silicon atom at the end of a linear organopolysiloxane in one molecule.

[0010] [Chemical formula]

[0011] In formula (1), R 1 and R 2 each independently represent a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R 3 each independently represents an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. R 1 and R 2 and R 3 As the aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms of R R 1 and R 2 and R 3 and R may be linear, cyclic, or branched, and specific examples thereof include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; and cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups.

[0012] Among these, as R 1 R 2 and R 3 a methyl group, an ethyl group, and a phenyl group are preferred, and from the viewpoints of curability, productivity, and cost, a methyl group is more preferred.

[0013] In formula (1), as the alkylene group of Z having 2 to 12 carbon atoms, those having 2 to 8 carbon atoms are preferred, and as the alkylene arylene group of Z having 8 to 12 carbon atoms, those having 8 to 10 carbon atoms are preferred. Specific examples of preferred Z include, but are not limited to, those represented by the following structural formulas.

[0014]

Chemical formula

[0015] The siloxane structural units (M unit, D unit, T unit, and Q unit) of the reactive silicon group-containing organopolysiloxane of the present invention are not particularly limited, and may have a linear structure, a branched structure, a cyclic structure, or a crosslinked structure in the siloxane skeleton. However, from the viewpoints of the mechanical properties of the resulting film and the storage stability of the surface treatment agent, a linear structure is preferred.

[0016] As the reactive silicon group-containing organopolysiloxane of the present invention, those represented by the following formula (2) are preferred.

[0017]

Chemical formula

[0018] In formula (2), each R 4 independently represents an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and each R 5 independently represents a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. R 4 and R 5 As the aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms and the aryl group having 6 to 10 carbon atoms of, the above R 1 , R 2 and R 3Examples include the same groups as those exemplified above. Among them, a methyl group, an ethyl group, and a phenyl group are preferable, and a methyl group is more preferable from the viewpoints of curability, productivity, and cost.

[0019] In formula (2), m is an integer from 0 to 2, and 2 is preferable from the viewpoint of improving the durability of the film. n is an integer from 1 to 100, and an integer from 5 to 50 is preferable from the viewpoints of improving the water repellency and water slipperiness of the film. When n exceeds 100, the durability of the resulting film may decrease.

[0020] Specific examples of the reactive silicon group-containing organopolysiloxane of the present invention include, but are not limited to, the following compounds.

[0021]

Chemical formula

[0022] The reactive silicon group-containing organopolysiloxane in which Z in the above formula (1) is an oxygen atom can be obtained by using a triorganosilanol compound such as trimethylsilanol as an initiator, ring-opening polymerization of a cyclotrisiloxane compound such as hexamethylcyclotrisiloxane in the presence of a pentacoordinate silicon catalyst, and then reacting with an organoxysilane represented by the following formula (6) for end-capping. Further, the reactive silicon group-containing organopolysiloxane in which Z in the above formula (1) is an alkylene group having 2 to 12 carbon atoms or an alkylene arylene group having 8 to 12 carbon atoms is a linear organopolysiloxane containing an alkenyl group at one end (hereinafter, also referred to as "linear organopolysiloxane containing an alkenyl group at one end").) and a disiloxane compound represented by the following formula (3) can be obtained by hydrosilylation reaction in the presence of a platinum group metal catalyst in air or an inert gas such as nitrogen.

[0023] As the linear organopolysiloxane containing an alkenyl group at one end, those represented by the following formula (4) are preferable.

[0024]

Chemical formula

[0025] In formula (4), R 6 represents an alkenyl group having 2 to 12 carbon atoms or an alkenylaryl group having 8 to 12 carbon atoms. As the alkenyl group having 2 to 12 carbon atoms of R 6 , those having 2 to 8 carbon atoms are preferable, and examples include vinyl group, allyl group, 3-butenyl group, 5-hexenyl group, 7-octenyl group, etc. As the alkenylaryl group having 8 to 12 carbon atoms of R 6 , those having 8 to 10 carbon atoms are preferable, and examples include p-vinylphenyl group, p-allylphenyl group, etc.

[0026]

Chemical formula

[0027] Specific examples of the disiloxane compound represented by the above formula (3) include, but are not limited to, those represented by the following structural formula. Among these, the disiloxane compound represented by formula (5) is preferable.

[0028]

Chemical formula

[0029] The disiloxane compound represented by the above formula (3) can be obtained, for example, by subjecting an organoxysilane represented by the following formula (6) and a disiloxane compound represented by the following formula (7) to an equilibration reaction in the presence of an acid and water.

[0030]

Chemical formula

[0031] The reaction ratio of the linear organopolysiloxane containing a terminal alkenyl group and the disiloxane compound represented by the above formula (3) suppresses by-products during the hydrosilylation reaction and, considering the storage stability of the composition and the mechanical properties of the cured product, for one alkenyl group in the alkenyl group-containing organopolysiloxane, the ratio at which the hydrosilyl group of the disiloxane compound represented by the above formula (3) is 0.8 to 2.5 is preferable, and the ratio of 0.9 to 2.0 is more preferable.

[0032] The platinum group metal catalyst used in the above hydrosilylation reaction is not particularly limited, and specific examples thereof include chloroplatinic acid, an alcohol solution of chloroplatinic acid, a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, tetrakis triphenylphosphine platinum, dichlorobis triphenylphosphine platinum, dichlorobis acetonitrile platinum, dichlorobis benzonitrile platinum, dichlorocyclooctadiene platinum, etc., and supported catalysts such as platinum-carbon, platinum-alumina, platinum-silica, etc. Among these, from the viewpoint of selectivity during hydrosilylation, a zero-valent platinum complex is preferable, and a toluene or xylene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex is more preferable. The amount of the platinum group metal catalyst used is not particularly limited, but from the viewpoints of reactivity, productivity, etc., based on the total mass of the linear organopolysiloxane containing a terminal alkenyl group and the disiloxane compound represented by the above formula (3), 0.1 to 1,000 ppm in terms of the mass of the platinum group metal is preferable, and 0.3 to 100 ppm is more preferable.

[0033] The above hydrosilylation reaction can be carried out without a solvent, but a solvent can also be used as necessary within a range that does not inhibit the reaction. Specific examples of the solvents that can be used include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, benzene, toluene, and xylene; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; ester solvents such as ethyl acetate and butyl acetate; aprotic polar solvents such as N,N-dimethylformamide; and chlorinated hydrocarbon solvents such as dichloromethane and chloroform. These solvents may be used alone or in combination of two or more.

[0034] The reaction temperature in the above hydrosilylation reaction is not particularly limited, but is preferably 0 to 200 °C, more preferably 40 to 110 °C, and even more preferably 60 to 100 °C. When a solvent is used, it is preferable to carry out the reaction in the range of 0 °C to the boiling point of the solvent. The reaction time is not particularly limited and is usually about 1 to 60 hours, but preferably 1 to 24 hours.

[0035] The surface treatment agent of the present invention contains the above-mentioned reactive silicon group-containing organopolysiloxane, its hydrolysis condensate, or both.

[0036] The surface treatment agent of the present invention can also be used by adding a solvent according to the use and workability. Specific examples of the organic solvents that can be used include esters such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate; hydrocarbons such as hexane, cyclohexane, heptane, octane, decane, dodecane, toluene, and xylene; halogenated hydrocarbons such as dichloromethane, 1,1-dichloroethane, and 1,2-dichloroethane; ketones such as methyl ethyl ketone, 2-pentanone, and methyl isobutyl ketone; ethers such as diethylene glycol monomethyl ether and dipropylene glycol monomethyl ether; and alcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and isobutyl alcohol. These may be used alone or in combination of two or more.

[0037] The concentration of the reactive silicon group-containing organopolysiloxane of the present invention contained in the surface treatment agent is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and even more preferably 0.5 to 5.0% by mass with respect to the entire surface treatment agent. By setting it within such a range, uniform and excellent water repellency and water slipperiness can be imparted to the coating film.

[0038] Further, the surface treatment agent of the present invention may contain a hydrolysis catalyst for the purpose of promoting the reaction between the hydrolyzable group of the reactive silicon group-containing organopolysiloxane and water and promoting the formation of silanol groups. Specific examples of the hydrolysis catalyst include organic acids such as acetic acid, formic acid, methanesulfonic acid, and p-toluenesulfonic acid; inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, etc. These may be used alone or in combination of two or more. Among these, methanesulfonic acid, p-toluenesulfonic acid, and sulfuric acid are preferred, and sulfuric acid is particularly preferred. The addition amount of the hydrolysis catalyst is preferably 0.1 to 15.0% by mass, more preferably 1.0 to 10.0% by mass with respect to the reactive silicon group-containing organopolysiloxane.

[0039] Furthermore, the surface treatment agent of the present invention may contain a curing catalyst. Specific examples of the curing catalyst include titanium catalysts such as titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetra-2-ethylhexoxide, and titanium tetraacetylacetonate; tin catalysts such as dibutyltin dilaurate, dibutyltin diacetate, and dioctyltin diacetate; aluminum catalysts such as aluminum secondary butoxide, aluminum trisacetylacetonate, aluminum bisethylacetoacetate, monoacetylacetonate, and aluminum trisethylacetoacetate; zirconium catalysts such as normal propyl zirconate, normal butyl zirconate, zirconium tetraacetylacetonate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, and zirconium tetraacetylacetonate, etc. The addition amount of the curing catalyst is preferably 0.1 to 15.0% by mass, more preferably 1.0 to 10.0% by mass, based on the reactive silicon group-containing organopolysiloxane.

[0040] The surface treatment agent of the present invention may further contain other organosilicon compounds having a hydroxy group or a hydrolyzable group bonded to an Si atom, their hydrolysis condensates, or mixtures thereof, other than the reactive silicon group-containing organopolysiloxane of the present invention described above. Examples of the hydrolyzable group include an alkoxy group, a halogen atom, an acyloxy group, an isocyanato group, and the like. Specific examples of other organosilicon compounds include, as silane compounds having an alkoxysilyl group, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, diphenyldimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, hexamethyldisilazane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane, etc.; and, as silane compounds having a halogenated silyl group, methyltrichlorosilane, ethyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, trifluoroethyltrichlorosilane, etc. The addition amount of other organosilicon compounds is not particularly limited as long as it does not affect the water repellency and water lubricity of the resulting cured film, but it is preferably 20% by mass or less based on the reactive silicon group-containing organopolysiloxane of the present invention.

[0041] In addition to the components described above, various additives can be added to the surface treatment agent of the present invention. Examples of the additives include metal oxides, resins, dyes, pigments, ultraviolet absorbers, antioxidants, etc., and specifically, silica sol, titania sol, alumina sol, etc. are mentioned. The addition amount of the additive is not particularly limited as long as it does not affect the water repellency and water lubricity of the resulting cured film, but it is preferably 30% by mass or less based on the reactive silicon group-containing organopolysiloxane of the present invention.

[0042] By applying the surface treatment agent of the present invention described above to a substrate and drying it, a water-repellent film can be formed on the substrate.

[0043] The material and shape of the substrate are not particularly limited, and specific examples thereof include organic resin substrates such as epoxy resin, phenolic resin, polyimide resin, polycarbonate resins such as polycarbonates and polycarbonate blends, acrylic resins such as poly(methyl methacrylate), polyester resins such as poly(ethylene terephthalate) and poly(butylene terephthalate), unsaturated polyester resins, polyamide resins, acrylonitrile-styrene copolymer resins, styrene-acrylonitrile-butadiene copolymer resins, polyvinyl chloride resins, polystyrene resins, blends of polystyrene and polyphenylene ether, cellulose acetate butyrate, polyethylene resins; metal substrates such as iron plates, copper plates, steel plates; paint-coated surfaces; glass; ceramics; concrete; slate plates; textiles; inorganic fillers such as wood, stone, tiles, (hollow) silica, titania, zirconia, alumina; glass fiber products such as glass cloth, glass tape, glass mat, glass paper including glass fiber.

[0044] The method for applying the surface treatment agent is not particularly limited, and specific examples thereof include known methods such as spray coating, spin coating, dip coating, roller coating, brush coating, bar coating, and flow coating, which can be appropriately selected and used. Further, after applying the surface treatment agent onto the substrate, it is preferable to wipe up the surface of the coating film with water.

[0045] The drying method after coating may be either natural drying or heat drying, but it is preferably carried out in the temperature range of 5 to 150 °C, more preferably near room temperature (5 to 35 °C). If it is 5 °C or higher, the reaction rate of the reactive silicon group-containing organopolysiloxane of the present invention increases, so that a water-repellent film having sufficient durability can be obtained in a short time. If it is 150 °C or lower, the modification and thermal decomposition of the reactive silicon group-containing organopolysiloxane of the present invention can be suppressed.

[0046] The film thickness of the water-repellent film is not particularly limited, but considering transparency and the mechanical strength of the film, etc., it is preferably 100 nm or less. Further, the above water-repellent film preferably has a water contact angle of 100° or more, particularly 103° or more, with a 2 μl water droplet, preferably has a falling angle of 45° or less, particularly 30° or less, and preferably has a haze value (cloudiness value) of preferably 5 or less, more preferably 1 or less, and even more preferably 0.5 or less.

[0047] The surface treatment agent of the present invention can also be directly applied onto the substrate surface to form a water-repellent film (cured film), but it is preferable to interpose an underlayer formed from the hydrolysis product of a silicon compound having a hydrolyzable group other than the reactive silicon group-containing organopolysiloxane of the present invention between the substrate surface and the water-repellent film. By providing such an underlayer, the bond between the water-repellent film and the substrate becomes stronger, and the durability of the water-repellent film of the present invention is improved.

[0048] As the organosilicon compound used for forming the underlayer, considering high hydrolyzability and the formation of an underlayer on the substrate near room temperature (5 to 35 °C), the isocyanate silane compound represented by the following general formula (8) is suitable.

[0049] [Chemical formula] (In the formula, k represents 0 or 1.)

[0050] The water-repellent film composed of the surface treatment agent of the present invention described above is excellent in water repellency, water slipperiness, and durability, and thus can be suitably used for water-repellent treatment of fiber products, glass of transportation machines, and vehicle bodies. In particular, when applied to window glass or mirrors, it can effectively prevent a decrease in visibility due to water droplet adhesion during rainy weather. [Examples]

[0051] Hereinafter, the present invention will be described more specifically by way of synthesis examples, examples, and comparative examples, but the present invention is not limited to these examples.

[0052] [1] Synthesis of disiloxane compound [Synthesis Example 1] Synthesis of disiloxane compound (5) [Chemical formula]

[0053] To a 300 mL separable flask equipped with a stirrer, a reflux condenser, and a thermometer, 200 g of trimethoxy(methoxymethyl)silane and 40.4 g of 1,1,3,3-tetramethyldisiloxane were added. While stirring at 7 °C, 1.2 g of concentrated sulfuric acid (98% by mass) was added dropwise. After the addition was completed, the mixture was stirred at 25 °C for 5 hours. Then, 6 g of Kyoward (registered trademark) 500SH (manufactured by Kyowa Chemical Industry Co., Ltd.) was added, and after stirring for 1 hour, the reaction solution was taken out by filtration. The reaction solution was distilled (distillation temperature 90 °C, vacuum degree 17 kPa) to obtain disiloxane compound (5). 1 H-NMR (CDCl3): δ 4.46~4.61 ppm (s, 1H, -SiH), 3.41~3.34 ppm (s, 9H, -Si(OCH3)2, -OCH3), 3.15~3.13 ppm (s, 2H, -CH2-), 0.00~0.02 ppm (s, 6H, -SiCH3)

[0054] [2] Synthesis of organopolysiloxane containing reactive silicon group [Example 1-1] Synthesis of organopolysiloxane a containing reactive silicon group Into a 2000 mL separable flask equipped with a stirrer, a thermometer and a Dimroth condenser, 403 g of hexamethylcyclotrisiloxane, 120 g of acetonitrile and 18 g of trimethylsilanol were charged. While stirring at 60 °C, 0.14 g of the compound represented by the following structural formula (9) was added, and the reaction was further carried out at 60 °C for 2 hours. Subsequently, while stirring at 50 °C, 180 g of vinyltrimethoxysilane and 4 g of t-butylamine were added, and the reaction was carried out for 5 hours. After completion of the reaction, the solvent was distilled off at 120 °C and a vacuum degree of 1.3 kPa for 3 hours to obtain a linear organopolysiloxane (10) having an alkenyl group at one end.

[0055] [Chemical formula]

[0056] Subsequently, into a 200 mL separable flask equipped with a stirrer, a thermometer, an ester adapter and a Dimroth condenser, 136 g of the linear organopolysiloxane (10) having an alkenyl group at one end and a toluene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (50 mass ppm as platinum) were charged. Next, while stirring at 60 °C, 68.3 g of the disiloxane compound (5) was added dropwise, and the reaction was further carried out at 60 °C for 3 hours. 1 It was confirmed by 1H-NMR measurement that the peak derived from the vinyl group of the raw material completely disappeared and the peak derived from the target product was detected, and the reaction was terminated. After completion of the reaction, the solvent was distilled off at 100 °C and a vacuum degree of 1.3 kPa for 3 hours to obtain an organopolysiloxane a containing a reactive silicon group.

[0057] [Chemical formula]

[0058] [Example 1-2] Synthesis of Reactive Silicon Group-Containing Organopolysiloxane b Into a 2000 mL separable flask equipped with a stirrer, a thermometer, and a Dimroth condenser, 443 g of hexamethylcyclotrisiloxane, 148 g of acetonitrile, and 20 g of trimethylsilanol were added. While stirring at 60 °C, 0.16 g of the compound represented by the above structural formula (9) was added, and the reaction was carried out at 60 °C for 2 hours. Subsequently, while stirring at 50 °C, 311 g of 7-octenyltrimethoxysilane and 5 g of t-butylamine were added, and the reaction was carried out for 5 hours. After the reaction was completed, the solvent was distilled off at 120 °C and a vacuum of 1.3 kPa for 3 hours to obtain a linear alkenyl group-containing organopolysiloxane (11) with one terminal alkenyl group.

[0059] Subsequently, into a 200 mL separable flask equipped with a stirrer, a thermometer, an ester adapter, and a Dimroth condenser, 163 g of the linear alkenyl group-containing organopolysiloxane (11) with one terminal alkenyl group and a toluene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (50 ppm by mass as platinum) were added. Next, while stirring at 60 °C, 82.8 g of the disiloxane compound (5) was added dropwise, and the reaction was carried out at 60 °C for 3 hours. 1 It was confirmed by 1H-NMR measurement that the peak derived from the vinyl group of the raw material completely disappeared and the peak derived from the target product was detected, and the reaction was terminated. After the reaction was completed, the solvent was distilled off at 100 °C and a vacuum of 1.3 kPa for 3 hours to obtain a reactive silicon group-containing organopolysiloxane b.

[0060]

Chemical formula

[0061] [Example 1-3] Synthesis of Reactive Silicon Group-Containing Organopolysiloxane c Into a 2000 mL separable flask equipped with a stirrer, a thermometer, and a Dimroth condenser tube, 443 g of hexamethylcyclotrisiloxane, 148 g of acetonitrile, and 20 g of trimethylsilanol were added. While stirring at 60 °C, 0.16 g of the compound represented by the above structural formula (9) was added, and the reaction was carried out at 60 °C for 2 hours. Subsequently, while stirring at 50 °C, 300 g of p-styryltrimethoxysilane and 5 g of t-butylamine were added, and the reaction was carried out for 5 hours. After the reaction was completed, the solvent was distilled off at 120 °C and a vacuum of 1.3 kPa for 3 hours to obtain a linear organopolysiloxane (12) containing an alkenyl group at one end.

[0062] Subsequently, into a 200 mL separable flask equipped with a stirrer, a thermometer, an ester adapter, and a Dimroth condenser tube, 157.5 g of the linear organopolysiloxane (12) containing an alkenyl group at one end and a toluene solution of a platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (50 ppm by mass as platinum) were added. Next, while stirring at 60 °C, 72.4 g of the disiloxane compound (5) was added dropwise, and the reaction was carried out at 60 °C for 3 hours. 1 It was confirmed by 1H-NMR measurement that the peak derived from the vinyl group of the raw material completely disappeared and the peak derived from the target product was detected, and the reaction was terminated. After the reaction was completed, the solvent was distilled off at 100 °C and a vacuum of 1.3 kPa for 3 hours to obtain a reactive silicon group-containing organopolysiloxane c.

[0063] [Chemical formula]

[0064] [Example 1-4] Synthesis of reactive silicon group-containing organopolysiloxane d Into a 2000 mL separable flask equipped with a stirrer, a thermometer, and a Dimroth condenser, 443 g of hexamethylcyclotrisiloxane, 148 g of acetonitrile, and 20 g of trimethylsilanol were added. While stirring at 60 °C, 0.16 g of the compound represented by the above structural formula (9) was added, and the reaction was further carried out at 60 °C for 2 hours. Subsequently, while stirring at 50 °C, 113 g of trimethoxy(methoxymethyl)silane and 5 g of t-butylamine were added, and the reaction was carried out for 5 hours. After completion of the reaction, the solvent was distilled off at 120 °C and a vacuum of 1.3 kPa for 3 hours to obtain a reactive silicon group-containing organopolysiloxane d.

[0065] [Chemical Formula]

[0066] [2] Preparation of Surface Treatment Agent [Example 2-1] To 19.0 g of ethyl acetate, 0.920 g of the reactive silicon group-containing organopolysiloxane a obtained in Example 1-1 and 0.080 g of 98% by mass sulfuric acid were added and mixed to obtain a surface treatment agent.

[0067] [Example 2-2] A surface treatment agent was obtained in the same manner as in Example 2-1, except that the reactive silicon group-containing organopolysiloxane a was changed to the reactive silicon group-containing organopolysiloxane b obtained in Example 1-2 in Example 2-1.

[0068] [Example 2-3] A surface treatment agent was obtained in the same manner as in Example 2-1, except that the reactive silicon group-containing organopolysiloxane a was changed to the reactive silicon group-containing organopolysiloxane c obtained in Example 1-3 in Example 2-1.

[0069] [Example 2-4] A surface treatment agent was obtained in the same manner as in Example 2-1, except that the reactive silicon group-containing organopolysiloxane a was changed to the reactive silicon group-containing organopolysiloxane d obtained in Example 1-4 in Example 2-1.

[0070] [Comparative Example 2-1] In Comparative Example 2-1, a surface treatment agent was obtained in the same manner as in Example 2-1, except that the linear organopolysiloxane a containing an alkenyl group at one terminal was changed to an organopolysiloxane e represented by the following formula.

[0071] [Chemical formula]

[0072] Each surface treatment agent prepared in Examples 2-1 to 2-4 and Comparative Example 2-1 was impregnated into tissue paper and wiped onto a glass substrate for coating. After natural drying for 1 minute, the tissue paper was impregnated with water, and the coating surface of the glass substrate was wiped up. Natural drying was carried out at 25°C for 1 hour to obtain a glass substrate with a water-repellent film. Using the obtained glass substrate with a water-repellent film, the following evaluation tests (1) to (4) were conducted. The results are shown in Table 1. The water contact angle and the water droplet sliding angle (falling angle) were measured with a contact angle meter equipped with a sliding unit (Drop Master DM-701 manufactured by Kyowa Interface Science Co., Ltd.). (1) Water repellency 2 μL of water was dropped onto the treated surface of the glass substrate with a water-repellent film, and the water contact angle was measured. (2) Water slipperiness 2 μL of water was dropped onto the treated surface of the glass substrate with a water-repellent film, and the falling angle was measured. (3) Ultrasonic cleaning test The glass substrate with a water-repellent film was immersed in an aqueous solution of 1% by mass surfactant (Lipon F, manufactured by Lion Hygiene Co., Ltd.), and irradiated with ultrasonic waves (100 W, 42 kHz) for 30 minutes. Regarding the glass substrate with a water-repellent film after the test, the water repellency and water slipperiness were evaluated in the same procedure as in (1) and (2) above. (4) Abrasion test An abrasion test was carried out on the treated surface of the glass substrate with a water-repellent film under the conditions of a 2 cm × 2 cm nylon cloth, a load of 1.2 kg, and 1,200 reciprocations. Regarding the glass substrate with a water-repellent film after the test, the water repellency and water slipperiness were evaluated in the same procedure as in (1) and (2) above.

[0073]

Table 1

[0074] As shown in Table 1, it can be seen that the glass substrates with water-repellent films obtained in Examples 2-1 to 2-4 have good water repellency and water slipperiness at the initial stage, after ultrasonic cleaning test and after wear test. On the other hand, it can be seen that the glass substrate with a water-repellent film obtained in Comparative Example 2-1 shows a remarkable decrease in water slipperiness, particularly after the ultrasonic cleaning test and after the wear test.

Claims

1. A reactive silicon group-containing organopolysiloxane containing one group represented by the following structural formula (1) bonded to a silicon atom at the end of a linear organopolysiloxane in one molecule. 【Chemical 1】 (In the formula, R 1 and R 2 each independently represent a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R 3 each independently represent an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, Z represents an oxygen atom, an alkylene group having 2 to 12 carbon atoms, or an alkylene arylene group having 8 to 12 carbon atoms, and a wavy line represents a bond.)

2. The reactive silicon group-containing organopolysiloxane according to Claim 1, represented by the following formula (2). [[Chemical 2]] (wherein, R 4 each independently represents an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and R 5 each independently represents a hydrogen atom, an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, R 1 , R 2 , R 3 and Z represent the same meanings as described above, m is an integer of 0 to 2, and n is an integer of 1 to 100.)

3. A surface treatment agent containing the reactive silicon group-containing organopolysiloxane according to Claim 1 or 2, its hydrolysis condensate, or both.

4. Furthermore, the surface treatment agent according to Claim 3 containing an acid catalyst.

5. An article to which the surface treatment agent according to Claim 3 is attached.

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