WO2020209186A1

WO2020209186A1 - Coating composition comprising one-terminal alkoxy group-containing siloxane, coating film, and article

Info

Publication number: WO2020209186A1
Application number: PCT/JP2020/015269
Authority: WO
Inventors: 千幸根岸
Original assignee: 信越化学工業株式会社
Priority date: 2019-04-12
Filing date: 2020-04-03
Publication date: 2020-10-15
Also published as: JP2020172610A; TW202041624A

Abstract

[Problem] The present invention has been made in view of the abovementioned circumstances, and the objective of the present invention is to provide a coating composition which has excellent workability when applying an uncured composition by means of a wiping operation to form a uniform film, and which imparts excellent curability and water sliding properties in a film after application. [Solution] This coating composition includes: (A) 100 parts by mass of at least one selected from among a linear organopolysiloxane having an alkoxysilyl group only at one terminal, a hydrolysate thereof, and a condensate thereof; (B) 5-15 parts by mass of at least one selected from among a fluoroalkane compound having an alkoxysilyl group at both terminals, a hydrolysate thereof, and a condensates thereof; (C) 60-200 parts by mass of an organic solvent having a boiling point or distillation range (temperature range from initial boiling point to dry point) in the range of 150-180°C, at 1 atmospheric pressure; and (D) 0.5-7.5 parts by mass of a hydrolysis condensation catalyst, where, component (A) and component (B) may be co-hydrolyzed and condensed before the curing of said composition.

Description

Coating compositions, coatings, and articles containing siloxanes containing one-ended alkoxy groups.

The present invention relates to a coating composition containing a siloxane containing a one-terminal alkoxy group, a coating film formed by curing the composition, and an article having the film.

Conventionally, a coating agent composition containing a silicone resin is applied to a building material, a painted steel sheet, etc. for the purpose of imparting water repellency, improving the appearance, and protecting the surface, and the uncured composition is wiped off with a cloth. By doing so, it is carried out to form a uniform film.

Patent Documents 1, 2, 3, and 4 describe a composition obtained by diluting a reactive silicone resin having an alkoxysilyl group at the terminal of the molecular chain with an organic solvent. In Patent Document 5, a composition obtained by diluting a reactive silicone resin having an alkoxysilyl group at the end of a molecular chain with an isoparaffinic solvent having a high boiling point (distillation temperature range of 185 ° C. or higher) is used as the first layer, and an organopoly having an amino group. A two-layer coating using a composition containing siloxane as a second layer is described. Patent Document 6 discloses a coating composition obtained by diluting a reactive siloxane having an alkoxysilyl group at the end of a molecular chain and a fluoroalkylsilane with an organic solvent, and treating an aluminum base material with the composition at 150 ° C. It is described that an aluminum fin agent for a heat exchanger having excellent water-sliding property can be obtained by heat-curing with.

Japanese Unexamined Patent Publication No. 2009-138603 Japanese Unexamined Patent Publication No. 2009-138602 JP 2013-166957 JP-A-2010-202717 Japanese Unexamined Patent Publication No. 2012-241093 Patent No. 5891043

However, although the conventional coating agent composition as described in the above patent document is excellent in workability, it is insufficient in terms of water-sliding property. Further, Patent Document 6 describes a coating agent composition having excellent water-sliding properties for aluminum fins, and describes a step of performing dip coating or the like to obtain a film and then heat-curing. When the coating composition described in Patent Document 6 is applied by wiping with a cloth, there are problems that drying is slow and curability is poor, and a sufficient film thickness cannot be obtained and water repellency is poor. Further, in response to this problem, if the silicone concentration is increased in order to increase the film thickness, there is a problem that the workability of the composition is lowered.

The present invention has been made in view of the above circumstances, and in a method of applying an uncured coating agent composition by wiping with a cloth, it is possible to form a uniform film and to apply the coating. It is an object of the present invention to provide a coating composition which is excellent in workability at the time of construction and further excellent in curability and water-sliding property of a film after construction.

As a result of diligent studies to achieve the above object, the present inventors have conducted a linear organopolysiloxane having an alkoxysilyl group at only one end, a fluoroalkane compound having an alkoxysilyl group at both ends, and a curing catalyst. And, in the coating agent composition containing an organic solvent, by adjusting the amount of the solvent, a coating agent was prepared which can be applied well even by the wiping method. Furthermore, by specifying the boiling point or distillation range of the solvent, when the coating is applied by the wiping method, it can be wiped evenly at the time of construction, the workability is excellent, and the coating agent is applied on the substrate for an appropriate time. Since it exists in a liquid state, the thin film forming ability is improved, and the curability at room temperature is also improved. Further, they have found that the coating film after construction has good water-sliding property, and have achieved the present invention.

That is, the present invention
(A) At least one selected from a linear organopolysiloxane having an alkoxysilyl group at only one end, a hydrolyzate thereof, and a condensate thereof: 100 parts by mass,
(B) At least one selected from a fluoroalkane compound having an alkoxysilyl group at both ends, a hydrolyzate thereof, and a condensate thereof: 5 to 15 parts by mass,
(C) Organic solvent having a boiling point or distillation range (temperature range from the initial distillate point to the dry point) of 150 to 180 ° C. at 1 atm: 60 to 200 parts by mass,
as well as,
(D) Hydrolysis condensation catalyst: 0.5 to 7.5 parts by mass,
A coating composition containing the above, wherein a part of the alkoxy groups of the component (A) and a part of the alkoxy groups of the component (B) may be co-hydrolyzed and condensed. provide.

The coating composition of the present invention can impart a thin film coating layer having excellent water-sliding properties to a metal surface, a painted surface, a resin surface, or the like, and has good workability and curability during wiping. Therefore, it can be suitably used for coating vehicles such as automobiles and trains, building materials, and molded bodies.

Hereinafter, each component will be described in detail.
(A) The linear organopolysiloxane (A) component is at least one of a linear organopolysiloxane having an alkoxysilyl group at only one end, a hydrolyzate thereof, and a condensate thereof, and is the present invention. It plays a major role in developing water-sliding properties in the cured film obtained from the coating composition. By containing the component (A), a siloxane chain having an optimum chain length is oriented on the surface of the coating film obtained by curing the coating composition, and the coating film can be provided with good water-sliding properties.

A linear organopolysiloxane having an alkoxysilyl group at only one end is preferably represented by the following formula (1).
^{_{^{_{R 1 3 SiO- [R 1 2}}}} SiO] n -SiR '2 R 2 (1)
^{(R 1,} independently of one another, an alkyl group having a carbon number of 1 ~ 4, ^{R 2} is a group represented by -OR ^3, or ^{_{_{(R 3 O) 3 -Si-}}} C 2 H 4 - is represented by R'is a group independently selected from the group represented by −OR ³ or the choice of R ¹ , and in the above, R ³ is an alkyl group having 1 to 4 carbon atoms independently of each other. And n is an integer from 10 to 200)

In the formula (1), R ¹ is an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, a butyl group, a propyl group, and an isopropyl group. A methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. n is a number of 10 to 200, preferably a number of 10 to 100, and particularly preferably a number of 20 to 70.

In the formula (1), ^{R 2} is a group represented by -OR ^3, or ^{_{_{(R 3 O) 3 -Si-}}} C 2 H 4 - is a group represented by, R ', independently of one another, -OR It is a group represented by ³ or a group selected from the above options of R ¹ , and in the above, R ³ is an alkyl group having 1 to 4 carbon atoms independently of each other. R ³ is an alkyl group having 1 to 4 carbon atoms independently of each other, preferably a methyl group, an ethyl group, or a propyl group, and particularly preferably a methyl group and an ethyl group.

The component (A) is a compound in which some or all of the alkoxy groups of the compound represented by the above formula (1) are hydrolyzed to form hydroxyl groups, or some of the hydroxyl groups of these compounds are dehydrated and condensed. It may be a condensed product. As the component (A), one type may be used alone, two or more types may be used in combination, and two or more types of co-hydrolyzed condensates may be used.

More specifically, the component (A) includes, but is not limited to, the compounds represented by the following average formulas (1-1) to (1-17). The component (A) is a compound in which some or all of the alkoxy groups of the compounds exemplified below are hydrolyzed to form hydroxyl groups, or a condensate in which some of the hydroxyl groups of these compounds are dehydrated and condensed. You may.

(B) Fluoroalkane compound The component (B) is at least one of a fluoroalkane compound having an alkoxysilyl group at both ends, a hydrolyzate thereof, and a condensate thereof, and is an alkoxysilyl activated by a fluoroalkylene group. The presence of groups or silanol groups allows the hydrolysis and condensation reactions to proceed rapidly. The component (B) co-hydrolyzes and condenses with the component (A) due to moisture in the air in the presence of the condensation catalyst (D) described later, and binds to the component to cure the composition and form a film. Play.

The component (B) preferably includes a bis (alkoxysilyl) fluoroalkane represented by the following formula (6). Alternatively, a part or all of the alkoxy groups of the compound represented by the following formula (6) are hydrolyzed to become hydroxyl groups, or a condensate in which some of the hydroxyl groups of these compounds are dehydrated and condensed. You may. As the component (B), one type may be used alone, two or more types may be used in combination, and two or more types of co-hydrolyzed condensates may be used. By including the component (B), the hydrolysis condensation reaction proceeds rapidly, and the obtained coating composition can have good curability.

In the above formula (6), R ⁴ and R ⁵ are independent hydrogen atoms or alkyl groups having 1 to 4 carbon atoms, and a methyl group or an ethyl group is particularly preferable. R ⁶ is a divalent hydrocarbon group having 1 to 6 carbon atoms, preferably a divalent alkylene group having 1 to 4 carbon atoms, and an ethylene group is more preferable.

p is an integer of 1 to 6, preferably an integer of 2 to 5. t is 0, 1 or 2, and is preferably 0 or 1, independent of each other.

Examples of the component (B) include, but are not limited to, compounds represented by the following structural formulas (6-1) to (6-12). Further, a part or all of the alkoxy groups of these compounds may be hydrolyzed to become hydroxyl groups, or a condensate in which some of the hydroxyl groups of these compounds are dehydrated and condensed.

The amount of the component (B) in the coating composition of the present invention is 5 to 15 parts by mass, preferably 6 to 14 parts by mass, and more preferably 7 to 13 parts by mass with respect to 100 parts by mass of the component (A). It is a mass part. When the amount of the component (B) is at least the above lower limit value, the coating composition of the present invention has appropriate curability and can form a uniform cured film. Further, when the blending amount of the component (B) is not more than the above upper limit value, the coating composition of the present invention can obtain preferable workability. In the coating composition of the present invention, a part of the alkoxy group contained in the component (A) and a part of the alkoxy group contained in the component (B) are co-hydrolyzed in advance before curing of the composition. A condensate may be formed (oligomerized). The oligomerization may be carried out, for example, by stirring the composition at room temperature (25 ° C.) for 10 minutes to 1 hour.

(C) Organic solvent The component (C) is an organic solvent having either a boiling point at 1 atm or a distillation range (temperature range from the initial distillation point to the dry point) of 150 to 180 ° C., preferably 160 to 180 ° C. It is a solvent, which is a necessary component for uniformly dissolving and diluting the components (A) and (B) to form a thin film. The organic solvent is preferably an aliphatic saturated hydrocarbon solvent. The number of carbon atoms of the aliphatic saturated hydrocarbon is not particularly limited, and any boiling point or distillation range of the solvent may satisfy the above range. For example, examples of the aliphatic saturated hydrocarbon solvent having the above boiling point or the above distillation range include a solvent containing an aliphatic saturated hydrocarbon having 9 to 12 carbon atoms as a main component. For example, isoparaffin, normal paraffin, naphthenic acid, and particularly preferably an isoparaffin solvent. A compound having the structure may have one or more functional groups such as a halogen group or various organic groups in the structure.

When the boiling point or the distillation range of the component (C) is at least the above lower limit value, the coating composition of the present invention can stay in a liquid state on the substrate for a time required for forming a coating film. Further, when the boiling point or the distillation range is not more than the above upper limit value, the coating composition of the present invention can have appropriate volatility, and preferable curability can be obtained. Here, when the boiling point is not a single temperature because the component is a mixture or the like, the distillation range (temperature range from the initial distillate point to the dry point) is preferably 150 to 180 ° C. instead of the boiling point. May be in the range of 160 to 180 ° C. In this case, it is particularly preferable that the temperature difference (temperature distribution) between the initial distilling point and the dry point is in the range of 20 ° C. from the viewpoint of workability.

The aliphatic saturated hydrocarbon solvent may be any one having the above boiling point or distillation range, and a commercially available product can be used. Examples of the commercially available products include Maruzen Petrochemical Co., Ltd. product Marcazole R (boiling point 177 ° C.), JXTG Energy Co., Ltd. product Cactus Normal Paraffin N-10 (initial distillation point 169 ° C., dry point 173 ° C.), ExxonMobil. Isopar G (initial distilling point 166 ° C., dry point 177 ° C.) of a product of Co., Ltd. can be mentioned. These aliphatic saturated hydrocarbon compounds may be used alone or as a mixture of a plurality of types. In the case of a mixture, an aliphatic saturated hydrocarbon compound in which the boiling point of the compound alone is not in the range of 150 to 180 ° C. may be contained as long as the distillation range is included in the above temperature range.

The amount of the component (C) in the coating composition of the present invention is 60 to 200 parts by mass, preferably 70 to 180 parts by mass, and more preferably 75 to 150 parts by mass with respect to 100 parts by mass of the component (A). It is a mass part. When the amount of the component (C) is at least the above lower limit value, the coating composition of the present invention has appropriate workability, and a uniform cured film can be formed. Further, when the blending amount of the component (C) is not more than the above upper limit value, the coating composition of the present invention can obtain preferable curability. If the blending amount of the component (C) exceeds the above upper limit value, the composition becomes diluted and the curability is lowered in the wiping coating with a cloth, which is not preferable.

(D) Hydrolysis and Condensation Catalyst The hydrolysis and condensation catalyst of the component (D) can be appropriately selected from known catalysts and used, for example, an organic tin compound, an organic titanium compound, an organic zirconium compound, an organic aluminum compound and the like. Organic metal compounds; inorganic acids such as hydrochloric acid and sulfuric acid; organic acids such as P-toluenesulfonic acid, various aliphatic or aromatic carboxylic acids; ammonia; inorganic bases such as sodium hydroxide, tributylamine, 1,5- Organic bases such as diazabicyclo [4.3.0] nonen-5 (DBN) and 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) can be mentioned, and these can be used alone. , Multiple types may be used together.

Among the above, an organic metal compound selected from an organic tin compound, an organic titanium compound and an organic aluminum compound is preferable, and more specifically, dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, Dioctyltin diacetate, dibutyltin bisacetylacetate, dioctyltin bisacetyllaurate, tetrabutyl titanate, tetranonyl titanate, tetraxethylene glycol methyl ether titanate, tetraxethylene glycol ethyl ether titanate, bis (acetylacetonyl) dipropyl titanate, Acetylacetone aluminum, aluminum bis (ethyl acetoacetate) mononormal butyrate, aluminum ethyl acetoacetate dinormal butyrate, aluminum tris (ethyl acetoacetate) and the like are preferable, and tetra is particularly preferable from the viewpoint of reactivity and solubility. Butyl titanates, aluminum ethyl acetoacetate dinormal butyrate, aluminum bis (ethyl acetoacetate) mononormal butyrate and their hydrolyzates are preferred.

The amount of the component (D) in the coating composition of the present invention is 0.5 to 7.5 parts by mass, more preferably 0.7 to 6 parts by mass, and 1 to 6 parts by mass with respect to 100 parts by mass of the component (A). 5 parts by mass is particularly preferable.

The curing temperature of the coating composition of the present invention is not particularly limited, but is preferably 10 ° C to 150 ° C, more preferably 15 ° C to 50 ° C. In addition, it is preferable to carry out under humidification in order to promote the reaction.

The coating composition of the present invention may further contain one or more diluents selected from alkoxysilanes, alkoxysilane oligomers, and diluent solvents, in addition to the above components (A) to (D). By adding these diluents, the viscosity of the composition, the curing time, and the hardness of the cured film can be adjusted. Therefore, the composition diluted with such a diluent can be suitably used as a coating agent. ..

The coating composition of the present invention may appropriately contain any additive as long as the effects of the present invention are not impaired. Examples of such additives include non-reactive silicone oils, reactive silicone oils, adhesion-imparting agents such as silane coupling agents, antistatic agents, rust preventives, colorants, surfactants, rheology modifiers, etc. UV absorbers, infrared absorbers, fluorescent agents, abrasives, fragrances, fillers, dyes, leveling agents, reactive diluents such as alkoxysilanes, non-reactive polymer resins, antioxidants, UV absorbers, light Examples thereof include stabilizers, antifoaming agents, dispersants, antistatic agents, and thixotropy-imparting agents.

The coating composition of the present invention can be applied to substrates such as various metals, glass, ceramics, and resins. Of these, application to metal steel sheets, painted metal steel sheets, or glass surfaces is preferable, and application to metal steel sheets and painted metal steel sheets is more preferable, especially for automobiles and the like. It is suitable for application to painted steel sheets used for vehicle exteriors.

The means for forming a film of the coating composition of the present invention is not particularly limited. For example, any application means can be appropriately selected, such as hand coating using fibers impregnated with the composition, brush coating, and machine coating using an automatic machine. A particularly preferred method in the present invention is as follows. That is, the coating composition of the present invention is impregnated with an appropriate amount of fibers such as a dry sponge or waste cloth, spread thinly on the surface of the substrate by hand, and wiped evenly with a cloth before the coating composition is cured. By raising it, an extremely thin coating film is formed, which is naturally dried or a dryer or the like is used to volatilize volatile components.

In this step, the components (A) and (B) come into contact with the moisture in the air, the hydrolysis condensation reaction proceeds by the action of the component (D), and the volatile components are volatilized on the substrate in parallel. Cross-link and cure with to form a resin-like cured product. The volatile component includes the organic solvent which is the component (C), and alcohol and water generated by the condensation reaction.

The film thickness of the coating film obtained by curing the coating composition of the present invention is preferably 0.01 to 20 mm, more preferably 0.02 to 10 mm, and further preferably 0.05 to 2 mm. When the film thickness of the cured film is within the above range, both good water smoothness and aesthetic appearance can be achieved. As described above, the curing conditions are not particularly limited, but are preferably 10 ° C to 150 ° C, more preferably 15 ° C to 50 ° C. In addition, it is preferable to carry out under humidification in order to promote the reaction. The coating composition of the present invention can be cured by natural drying or a drying step in a dryer. In the case of natural drying, it is carried out by allowing it to stand at room temperature (25 ° C.) for, for example, 2 hours, more preferably 5 hours. When a dryer or the like is used, it is carried out by drying at, for example, 40 ° C. to 200 ° C., preferably 50 ° C. to 150 ° C., more preferably 60 ° C. to 120 ° C., for example, 1 hour, more preferably 3 hours. ..

Further, in the coating composition of the present invention, the surface of the coating film exhibits the characteristics of water skiing, antifouling, and aesthetic improvement. Due to these characteristics, it becomes difficult to be soiled by fingerprints, sebum, human oil such as sweat, cosmetics, etc., and even when stains are attached, a cured product surface having excellent wiping property is provided. Therefore, the coating composition of the present invention is an antifouling composition used to form a coating film or a protective film on the surface of an article that may be soiled by human fat, cosmetics, etc. when the human body touches it. It is also useful as.

Examples of such antifouling-treated articles include optical magnetic discs, optical discs such as CDs / LDs / DVDs / Blu-ray discs, optical recording media typified by hologram recording, etc .; glasses lenses, prisms, lens sheets, pellicle Optical components and optical devices such as membranes, polarizing plates, optical filters, lenticular lenses, frennel lenses, antireflection films, optical fibers and optical couplers; CRTs, liquid crystal displays, plasma displays, electroluminescence displays, rear projection displays, fluorescent display tubes Various screen display devices such as (VFD), field emission projection displays, toner-based displays; especially PCs, mobile phones, personal digital assistants, game machines, electronic book readers, digital cameras, digital video cameras, automatic cash withdrawal deposit devices, cash Automatic payment machines, vending machines, navigation devices for automobiles, image display devices such as security system terminals, and touch panel (touch sensor, touch screen) type image display input devices that also operate them; mobile phones, personal digital assistants, Input devices such as electronic book readers, portable music players, portable game machines, remote controllers, controllers, keyboards, etc., panel switches for in-vehicle devices; housings for mobile phones, personal digital assistants, cameras, portable music players, portable game machines, etc. Surfaces: Automotive exteriors, pianos, luxury furniture, marble, etc. surfaces; Protective glass for art exhibitions, show windows, showcases, advertising covers, photostand covers, watches, automotive windshields, trains, aircraft, etc. Members made of transparent glass or transparent plastic (acrylic, polycarbonate, etc.) such as window glass, automobile headlights, tail lamps; various mirror members and the like can be mentioned.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
[Examples 1 to 14 and Comparative Examples 1 to 16]
Each of the following components was mixed at the mass ratios shown in Tables 1 and 2 to prepare a coating composition.
[(A) component]
(A-1): the average formula _{_{(CH 3) 3 SiO ((}} CH 3) 2 SiO) 30 Si (OCH 3) Polysiloxane (A-2) represented by _3: average formula (CH ₃₎ ₃ SiO ( _{_{_{(CH 3) 2 SiO) 60}}} Si (OCH 3) polysiloxane (A-3 represented by the _3): the average formula _{_{_{(C 2 H 5) 3 SiO}}} ((CH 3) 2 SiO) 30 Si (OCH 2 CH ₃ ) Polysiloxane represented by ₃ [Comparative component]
(A-4): the average formula _{_{(CH 3 O) 3 SiO (}} (CH 3) 2 SiO) 30 Si (OCH 3) polysiloxane represented by ₃

[(B) component]
(B-1): Fluoroalkane compound represented by structural formula (CH ₃ O) ₃ SiCH ₂ CH ₂ C ₄ F ₈ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (B-2): Structural formula (CH ₃₎ _{_{_{O) 3 SiCH 2 CH 2 C}}} 2 F 4 CH 2 CH 2 Si (OCH 3) fluoroalkane compound represented by _{3 (B-3):} formula _{_{_{(C 2 H 5 O) 3}}} SiCH 2 CH 2 C 2 Fluoroalkane compound represented by F ₄ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ [Comparative component]
(B-4): Fluoroalkane compound represented by structural formula C ₆ F ₁₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ (B-5): Structural formula (CH ₃ O) ₃ Si (CH ₂ ) ₆ Si Silane compound represented by (OCH ₃ ) ₃ (B-6): Silane compound represented by structural formula CH ₃ (CH ₂ ) ₅ Si (OCH ₃ ) ₃ .

[Component (C)]
(C-1): Organic solvent composed of a mixture of isoparaffin (initial distillation point 166 ° C., dry point 177 ° C., Isopar G, manufactured by EXXONMOBIL).
[Comparison component]
(C-2): Organic solvent composed of a mixture of isoparaffin (initial distillation point 180 ° C., dry point 188 ° C., Isopar H, manufactured by EXXONMOBIL)
(C-3): Organic solvent composed of a mixture of isoparaffin (initial distillation point 114 ° C., dry point 139 ° C., Isopar E, manufactured by EXXONMOBIL).

[(D) component]
(D-1): Aluminum alkoxide compound (DX9740, manufactured by Shin-Etsu Chemical Co., Ltd.)
(D-2): Tetra-N-butoxytitanium (TIO ₂ equivalent weight ratio 23.5 wt%, B-1, manufactured by Nippon Soda Corporation)

[Example 15]
0.11 g of ion-exchanged water was mixed with 100 parts by mass of the composition prepared in Example 1 and stirred at 25 ° C. for 2 hours to co-hydrolyze and condense (oligomerize) the components (A) and (B). The composition was obtained.

Each coating composition of Examples and Comparative Examples was evaluated by the following method. The results are shown in Tables 1 and 2.

Workability evaluation method 2 mL of each coating composition is applied to a black coated plate (material: SPCC-SD, standard: JIS-G-3141, dimensions: 0.8 mm x 70 mm x 150 mm, aminoalkyd on one side after chemical electrodeposition. It was dropped on a black-painted product (Asahi Bee Techno Co., Ltd. product), thinly applied by hand using a tissue paper, and allowed to stand at 25 ° C. for 5 minutes. Then, the excess was wiped off with a dry microfiber cloth. At this time, those that can be wiped lightly and evenly are ○, those that are slightly uneven or have a slightly heavy wiping resistance are △, and those that are markedly uneven or are difficult to wipe are ×. As shown in Table 1 or 2.

Curability evaluation method A test piece to which the coating composition was applied was prepared by the same method as the workability evaluation. This was further allowed to stand at 25 ° C. for 2 hours to be cured and cured to obtain a test piece having a coating film composed of the cured product. When the coated surface of the test piece was touched with a finger, the one with no tack remaining was marked with ◯, and the one with tack remaining was marked with x, and is shown in Table 1 or 2.

Water-sliding evaluation method A test piece to which the coating composition was applied was prepared by the same method as the workability evaluation. This was further allowed to stand at 25 ° C. for 12 hours to be cured and cured to obtain a test piece having a coating film composed of the cured product. One drop (about 20 μL) of purified water was dropped onto the test piece and gradually inclined from a horizontal state, and the water sliding angle, which is the angle at which the water drop began to flow, was evaluated as an index. For the measurement of the water fall angle, DROP MASTER DM-701 manufactured by Kyowa Interface Science Co., Ltd. was used. The evaluation criteria are shown in Table 1 or 2 with a water sliding angle of less than 25 ° as ◯, a water sliding angle in the range of 25 to 35 ° as Δ, and a water sliding angle of more than 35 ° as ×.

Among the above test items, it is particularly preferable that there is no item of judgment × and the number of judgment Δ is 1 or less.

As shown in Table 2, the coating composition of Comparative Example 7 in which polysiloxane having an alkoxysilyl group at both ends was used instead of the component (A) of the present invention was inferior in water smoothness. The coating compositions of Comparative Examples 8, 9 and 10 using a silane compound other than the component (B) of the present invention had poor water-sliding properties.

Further, as shown in Table 2, the coating composition of Comparative Example 2 in which the amount of the component (B) is too small is inferior in curability and water-sliding property, and the coating composition of Comparative Example 1 in which the amount of the component (B) is too large. The thing was inferior in workability. Further, the coating agents of Comparative Examples 11 and 12 using an isoparaffin organic solvent which does not satisfy the distillation range of the present invention instead of the component (C) of the present invention were insufficient in workability and curability. Since the coating agent of Comparative Example 3 in which the amount of the component (C) was too small contained the component (A) in a high concentration, sufficient workability could not be obtained. Further, in the coating composition of Comparative Example 4 in which the blending amount of the component (C) exceeds the upper limit value of the present invention, the composition was diluted and the curability was poor.

Furthermore, the coating agent of Comparative Example 5 in which the amount of the component (D) was too small was inferior in curability. The coating composition of Comparative Example 6 in which the amount of the component (D) was too large was inferior in workability. Further, the coating compositions of Comparative Examples 13 to 16 containing no of the components (A) to (D) are inferior to at least one of curability, water-sliding property, and workability, and have excellent properties in all of them. No film was obtained.

In contrast to the above, as shown in Examples 1 to 15 of Table 1, all of the coating compositions of the present invention provided a coating film having good workability and excellent water-sliding and curable properties.

The coating composition of the present invention is excellent in workability when wiping with a cloth in an uncured state to form a film and curability at room temperature. In addition, the cured coating can have excellent water-sliding properties. Therefore, it is useful as a coating agent for forming a thin film coating layer for imparting water-sliding property and antifouling performance to a vehicle such as an automobile and a train, a building material, a metal surface such as a molded body, a painted surface or a resin surface.

Claims

(A) At least one selected from a linear organopolysiloxane having an alkoxysilyl group at only one end, a hydrolyzate thereof, and a condensate thereof: 100 parts by mass,
(B) At least one selected from a fluoroalkane compound having an alkoxysilyl group at both ends, a hydrolyzate thereof, and a condensate thereof: 5 to 15 parts by mass,
(C) Organic solvent having a boiling point or distillation range (temperature range from the initial distillate point to the dry point) of 150 to 180 ° C. at 1 atm: 60 to 200 parts by mass,
as well as,
(D) Hydrolysis condensation catalyst: 0.5 to 7.5 parts by mass,
The coating composition containing the above, wherein a part of the alkoxy groups of the component (A) and a part of the alkoxy groups of the component (B) may be co-hydrolyzed and condensed.
Wherein component (A) is represented by the following formula (1) represented by claim 1 A coating composition according R 1 3 SiO- [R 1 2 SiO] n -SiR '2 R 2 (1)
(R 1, independently of one another, an alkyl group having a carbon number of 1 ~ 4, R 2 is a group represented by -OR 3, or (R 3 O) 3 -Si- C 2 H 4 - is represented by R'is a group independently selected from the group represented by −OR 3 or the choice of R 1 , and in the above, R 3 is an alkyl group having 1 to 4 carbon atoms independently of each other. And n is an integer from 10 to 200).
The coating composition according to claim 2, wherein in the formula (1), n is a number of 10 to 100, R 1 is a methyl group, and R 3 is a methyl group or an ethyl group.
The coating composition according to claim 2 or 3, wherein n is a number of 20 to 70.
The coating composition (R 4 O) 3-t (R 5 ) t Si-R 6- (R 4 O) according to any one of claims 1 to 4, wherein the component (B) is represented by the following formula (6). C p F 2p ) -R 6- Si (R 5 ) t (OR 4 ) 3-t (6)
(In the formula, R 4 and R 5 are alkyl groups having 1 to 4 carbon atoms independently of each other, and R 6 is a divalent hydrocarbon group having 1 to 6 carbon atoms independently of each other. p is an integer from 1 to 6 and t is 0, 1 or 2 independently of each other).
R 4 and R 5 are independent of each other as a methyl or ethyl group, R 6 is an alkylene group having 1 to 4 carbon atoms, p is an integer of 2 to 5, and t is independent of each other. The coating composition according to claim 5, which is 0 or 1.
The coating composition according to any one of claims 1 to 6, wherein the amount of the component (B) is 6 to 14 parts by mass with respect to 100 parts by mass of the component (A).
The coating composition according to any one of claims 1 to 7, wherein the amount of the component (C) is 70 to 180 parts by mass with respect to 100 parts by mass of the component (A).
The coating composition according to any one of claims 1 to 8, wherein the amount of the component (D) is 0.7 to 6 parts by mass with respect to 100 parts by mass of the component (A).
A coating agent for railroad vehicle coating or automobile exterior steel sheet coating, which comprises the coating composition according to any one of claims 1 to 9.
A coating formed by curing the coating composition according to any one of claims 1 to 10.
The article having the coating film according to claim 11.
The article according to claim 12, wherein the film thickness is 0.01 to 20 mm.