JP2021031575A - Aqueous composition for coated surface - Google Patents

Abstract

To provide an aqueous composition having excellent durability against physical impact such as scratches and outdoor exposure, stain resistance to stains, and oil resistance in a coating film to be produced.SOLUTION: There is provided an aqueous composition for coated surface containing (A) a silicone emulsion containing (a-1) an alkoxysilane represented by the following general formula (1), Xn-Si-(OY)4-n...(1), where X represents an alkyl group having 1 to 18 carbon atoms; Y represents an alkyl group having 1 to 4 carbon atoms; and n represents an integer of 1 to 3), (a-2) an organopolysiloxane which is a hydrolysis condensate of the alkoxysilane, (a-3) a nonionic surfactant, and (a-4) water; (B) a silsesquioxane having an average particle size of 10 to 200 nm; (C) a fluororesin; (D) a carboxylic acid salt; (E) cellulose nanofibers; and (F) water.SELECTED DRAWING: None

Description

The present invention relates to an aqueous composition that glosses the surface of an object to be coated by applying it to the surface of a desired article such as glass of a vehicle or a main body of a vehicle body, and contains water as a solvent.

Conventionally, waxes mainly composed of carnauba wax and petroleum wax, modified silicones such as dimethyl silicone and aminosilicone, and silicones such as silicone resin are mainly used as polishes for vehicles such as automobiles. The effects of the types were poor, and the silicones were easily contaminated and it was difficult to formulate a reactive cured product.

In recent years, silicone, which is polycondensed with alkoxysilane, is dispersed and dissolved in an aqueous solvent, and the object to be coated is treated by spraying or hand coating to form a glass-like effect film in the drying process, which is repellent. Paints with excellent water-based, glossy and durable properties are known.

For example, Patent Document 1 discloses an aqueous composition obtained by mixing silicone having polycondensation of alkoxysilane, an acrylic silicone copolymer emulsion, cellulose nanofibers, water, or the like as an emulsifier.

Japanese Unexamined Patent Publication No. 2018-2038919

However, the composition of Cited Document 1 has a problem that the durability against physical impact such as scratches on the coating film after the coating film is formed and outdoor exposure and the adhesion of stains are not always good.

Therefore, it is an object of the present invention to provide an aqueous composition having excellent durability against physical impact such as scratches and outdoor exposure, and stain resistance against stains in the coating film to be produced.

The present inventors have conducted extensive research on aqueous compositions, and by prescribing various compounds, the compositions have been made resistant to physical impacts such as scratches and outdoor exposure, stain resistance to stains, and oil resistance. They have found that an excellent coating film can be produced, and have arrived at the present invention based on these findings.

[1] That is, the present invention
(A-1) Alkoxysilane represented by the following general formula (1) and
X _n −Si− (OY) _4-n・ ・ ・ ・ ・ ・ ・ ・ ・ (1)
(In the formula, X is an alkyl group having 1 to 18 carbon atoms, Y is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3) (a-2) A hydrolyzed condensate of the alkoxysilane. Organopolysiloxane, (a-3) nonionic surfactant, (a-4) water-containing (A) silicone emulsion, and (B) silsesquioki with an average particle size of 10 to 200 nm. A water-based composition for a coated surface, which comprises sun, (C) a fluororesin, (D) a carboxylate, (E) a cellulose nanofiber, and (F) water.

[2] The aqueous composition for a coated surface according to the above [1], wherein the carboxylate is at least one selected from dibutyltin dilaurate and tris (2-ethylhexane) bismuth. is there.

[3] The aqueous composition for a coated surface according to claim 1 or 2, wherein the silsesquioxane is spherical.

According to the aqueous composition of the present invention, it is possible to prepare a coating film having excellent durability against physical impact such as scratches and outdoor exposure, stain resistance against stains, and oil resistance.

Hereinafter, embodiments of the aqueous composition for a coated surface of the present invention will be described in detail. The notation indicating the range in the description includes the upper limit and the lower limit.

The coating film composition of the present invention comprises (A) a silicone emulsion, (B) silsesquioxane, (C) a fluororesin, (D) a carboxylate, (E) cellulose nanofibers, and ( F) Contains water. As will be described later, a composition containing at least these components can produce a coating film having excellent durability against physical impact such as scratches and outdoor exposure, and stain resistance against stains.

The (A) silicone emulsion comprises (a-1) a specific alkoxysilane, (a-2) an organopolysiloxane which is a hydrolysis condensate of the alkoxysilane, and (a-3) a nonionic surfactant. And (a-4) an emulsion containing water. (A) Regarding the silicone emulsion, each component can be adjusted by itself so as to meet the conditions described later, or a commercially available product can be purchased.

The alkoxysilane (a-1) contained in the present invention is a compound represented by the following general formula (1).
X _n −Si− (OY) _4-n・ ・ ・ ・ ・ ・ ・ ・ ・ (1)
(In the formula, X is an alkyl group having 1 to 18 carbon atoms, Y is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3 carbon atoms).
According to the alkoxysilane, it can be bonded to the base material to be coated to serve as a base agent for a coating film, and can impart durability and stain resistance.

Examples of the arcocisilane include monofunctional trimethylmethoxysilane, triethylmethoxysilane, trimethylethoxysilane, and triethylethoxysilane, and bifunctional dimethyldimethoxysilane, diethyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, and dimethyldiethoxy. Silane, diethyldiethoxysilane, etc., trifunctional methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-hexyltri Methoxysilane, n-octyltrimethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-tetradecyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, methyltriethoxy Silane, ethyltriethoxysilane, n-propyltriethoxysilane, isopropyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltriethoxy. Silane, n-dodecyltriethoxysilane, n-tetradecyltriethoxysilane, n-hexadecyltriethoxysilane, n-octadecyltriethoxysilane and the like are preferable, and the trifunctional arcocisilane is more preferable. One of them or two or more of them can be used in combination.

Further, the content ratio of the alkoxysilane represented by the general formula (1) in the (A) silicone emulsion is preferably 1 to 30% by weight, preferably 2 to 25% by weight. preferable. (A-1) When the content ratio of the alkoxysilane represented by the general formula (1) is within this range, durability and stain resistance are imparted to the surface of the substrate to be coated, and further, aggregation due to hydrolysis is also carried out. It is less likely to occur, and the storage stability of a uniform solution can be improved even after a long period of time.

The organopolysiloxane (a-2) which is a hydrolyzate of the alkoxysilane contained in the present invention is obtained by dehydrating and condensing the hydrolyzate of the alkoxysilane represented by (a-1) the general formula (1). It is a polymer formed.

The organopolysiloxane has an average particle size of preferably 200 to 1000 nm, preferably 230 to 500 nm. When the average particle size of the organopolysiloxane is in this range, the surface of the base material to be coated is imparted with durability and stain resistance, and aggregation due to hydrolysis is less likely to occur to improve storage stability. Can be done. As a method for measuring the average particle size of the organopolysiloxane, it is preferable to measure by a laser diffraction / scattering method. Specifically, it can be measured by LA-920 or the like, which is a laser diffraction / scattering type particle size distribution measuring device manufactured by HORIBA, Ltd. The organopolysiloxane has a polymerization average molecular weight of preferably 210 to 10000, preferably 300 to 6000. When the polymerization average molecular weight of the organopolysiloxane is in this range, durability and stain resistance are imparted to the surface of the substrate to be coated, and aggregation due to hydrolysis is less likely to occur, so that storage stability can be improved. it can. As a method for measuring the polymerization average molecular weight of the organopolysiloxane, it is preferable to calculate it in terms of standard polystyrene by using the GPC method (gel permeation chromatography) using toluene or the like as a developing solvent.

The content of (a-2) organopolysiloxane, which is a hydrolyzed condensate of the alkoxysilane, in the (A) silicone emulsion is preferably 1 to 30% by weight, preferably 1 to 20% by weight. Is preferable. When the content ratio of the organopolysiloxane is in this range, durability and stain resistance are imparted to the surface of the substrate to be applied, and aggregation due to hydrolysis is less likely to occur, so that storage stability can be improved. ..

The (a-3) nonionic surfactant contained in the present invention has an alkyl chain having a linear or branched chain having 12 to 20 carbon atoms and an oxy represented by _{−CH 2} CH _{2 O−.} Polyoxyethylene (POE) alkyl ether, polyoxypropylene (POP) alkyl ether, polyoxyethylene (polyoxyethylene (POP) alkyl ether, which is composed of at least one of an ethylene unit or _{an oxypropylene unit represented by -CH 2} CH (CH _{3) O-.} POE) A surfactant such as polyoxypropylene (POP) alkyl ether. The oxyethylene unit and the oxypropylene unit preferably contain 1 to 100, preferably 1 to 50, and more preferably 1 to 20. When both the oxyethylene unit and the oxypropylene unit are present in the nonionic surfactant, the oxyethylene unit and the oxypropylene unit can be bonded at random or in a block, respectively.

Specific examples of the (a-3) nonionic surfactant include POE (7) lauryl ether, POE (9) lauryl ether, POE (11) lauryl ether, POE (10) cetyl ether, and POE (15) cetyl. Ether, POE (20) cetyl ether, POE (5) oleyl ether, POE (10) oleyl ether, POE (20) oleyl ether, POP (5) lauryl ether, POP (7) cetyl ether, POP (10) oleyl ether , POE (3) POP (5) lauryl ether and the like. The numerical values in parentheses of POE and POP indicate the number of units of oxyethylene unit and oxypropylene unit.

The content of the (a-3) nonionic surfactant in the (A) silicone emulsion is preferably 1 to 10% by weight, preferably 2 to 8% by weight. When the content ratio of (a-3) nonionic surfactant is in this range, the emulsion stability of (A) silicone emulsion can be maintained.

The water (a-4) contained in the present invention is for making (A) a silicone emulsion into an emulsion. As the water (a-4), any water such as purified water, ion-exchanged water, and industrial water can be used. Further, the trace component contained in water may also be contained within a range that does not affect the curability at the time of forming an emulsion of (A) silicone emulsion or preparing a coating film.

The water content of (a-4) in the (A) silicone emulsion is preferably 30 to 70% by weight, preferably 40 to 60% by weight. When the content ratio of (a-4) water is in this range, the emulsion stability of (A) silicone emulsion can be maintained.

Then, the non-volatile components of (a-1) alkoxysilane, (a-2) organopolysiloxane and (a-3) nonionic surfactant in the (A) silicone emulsion in the non-volatile content of the aqueous composition of the present invention. The content ratio of is preferably 10 to 60% by weight, and preferably 15 to 55% by weight. When the content ratio of the silicone emulsion (A) is in this range, durability and stain resistance can be continuously maintained on the surface of the base material to be applied, and workability and wiping work are also improved.

The (B) silsesquioxane contained in the present invention has a structure of (RSiO _1.5 ) n (where R is an arbitrary alkyl group and n is an integer of 2 or more) synthesized from a trifunctional alkoxysilane. It is a compound having an average particle size of 10 to 200 nm. By containing the silsesquioxane, the durability can be improved by hardening the coating film formed by the siloxane bond in the skeleton, and by having an alkyl group (a-1) alkoxy. It has good affinity with silane and (a-2) organopolysiloxane and can be uniformly dispersed as a composition. Further, the silsesquioxane is preferably spherical. When the silsesquioxane is spherical, it can be easily dispersed uniformly in the prepared coating film, and the durability can be uniformly improved in the coating film. Further, the average particle size of (B) silsesquioxane is more preferably 15 to 100 nm. (B) When the average particle size of silsesquioxane is in the range of 10 to 200 nm, as described above, it is uniformly dispersed in other components to harden the coating film as a whole, thereby improving durability against scratches and the like. Can be improved. As a method for measuring the average particle size of silsesquioxane, it is preferable to measure by a laser diffraction / scattering method. Specifically, it can be measured by LA-920 or the like, which is a laser diffraction / scattering type particle size distribution measuring device manufactured by HORIBA, Ltd.

The silsesquioxane forms a dispersion with (a-3) nonionic surfactant or (a-4) water contained in (A) silicone emulsion, or (A) silicone emulsion. Separately from the product, a nonionic surfactant such as polyoxyethylene, polyoxypropylene, polyoxyethylene (POE) alkyl ether, polyoxypropylene (POP) alkyl ether and a water-soluble solvent such as water are previously dispersed. When formed and blended as a substance, silsesquioxane is dispersed in the aqueous composition without causing bias such as precipitation and large aggregation, and a uniform coating film can be formed.

The non-volatile content of the aqueous composition of the present invention (B) silsesquioxane (nonvolatile content) is preferably 5 to 40% by weight, preferably 10 to 30% by weight. When the content ratio of the dispersion composition of (B) silsesquioxane is within this range, the durability of the produced coating film can be improved, and the workability and wiping work can be improved.

The fluororesin (C) contained in the present invention is a polymer compound in which a fluorine atom is bonded in the structure. According to the fluororesin, a coating film that is the base of the coating film is formed on the surface of the object to be coated, and stains are less likely to adhere to the coating film due to fluorine atoms in the structure, so that the stain resistance to the coating film is improved. Can be made to.

The fluororesin (C) is, for example, polytetrafluoroethylene, fluoroethylene / vinyl ether copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / ethylene. Copolymers, polyvinylidene fluorides, polychlorotrifluoroethylene, chlorotrifluoethylene / ethylene copolymers and the like are preferable. By using such a fluororesin, it becomes difficult for fluorine atoms to adhere to dirt. Furthermore, since the bond dissociation energy of carbon-fluorine is approximately 490 to 514 kJ / mol, which is larger than the bond dissociation energy of carbon-hydrogen of approximately 410 to 431, it decomposes even when exposed to sunlight including ultraviolet rays. Since it has light resistance that it is difficult, it is also excellent in durability. A completely fluorinated resin in which all the hydrogen atoms bonded to the carbon atoms of the main chain are replaced with fluorine atoms may be used, or as long as the light resistance is good, some of the hydrogen atoms bonded to the carbon atoms of the main chain become fluorine atoms. It may be a substituted partially fluorinated resin.

The (C) fluororesin forms an emulsion with (a-3) nonionic surfactant or (a-4) water contained in (A) silicone emulsion, or (A) silicone emulsion. Separately from the product, a nonionic surfactant such as polyoxyethylene, polyoxypropylene, polyoxyethylene (POE) alkyl ether, polyoxypropylene (POP) alkyl ether, a water-soluble solvent such as water, and an emulsion in advance. When the fluororesin is formed and blended, the fluororesin is dispersed in the aqueous composition without causing bias such as precipitation and large aggregation, and a uniform coating film can be formed.

(C) In order to improve the hydrophilicity of the fluororesin and make it easier to emulsify, a fluororesin having at least one of a carboxyl group, a sulfonyl group and a phosphoric acid group in the side chain can also be used. For example, a hydrolyzate of a copolymer of tetrafluoroethylene and perfluoro [2- (2-fluorocarbonylethoxy) propyl vinyl ether], a common weight of a methylene fluoride chain having a carbonyl alkoxide and a vinyl alcohol of trifluoroethylene. A fluororesin having a carboxyl group in the side chain can be produced by using a coalesced hydrolyzate, a hydrolyzate of a polymer of perfluoro [2- (2-fluorocarbonylethoxy) propyl vinyl ether], or the like, which is preferable.

The content of the fluororesin (nonvolatile content) in the non-volatile content of the aqueous composition of the present invention is preferably 5 to 65% by weight, preferably 10 to 70% by weight. When the content ratio of the fluororesin is in this range, the water and oil repellency and stain resistance of the produced coating film can be improved.

The compounding ratio (weight ratio) of (A) silicone emulsion and (B) silsesquioxane to (C) fluororesin is as follows: (B) silsesquioxane and (C) fluororesin are (A) silicone emulsified. It is preferably blended in an amount of 0.04 to 200, and more preferably 0.05 to 22 with respect to the product 1. When the compounding ratio of (A) silicone emulsion to (B) silsesquioxane and (C) fluororesin is within this range, the prepared coating film is durable against physical impact and outdoor exposure, and resistant to stains. It can be contaminated.

The (D) carboxylate of the present invention is a salt composed of an organic compound having a carboxyl group and a metal. The carboxylate can promote the condensation reaction of (a-1) alkoxysilane and (a-2) organopolysiloxane in the (A) silicone emulsion to prepare a strong coating film.

As the carboxylate (D), for example, dibutyltin dilaurate, tris (2-ethylhexane) bismuth, sodium laurate, sodium stearate, sodium oleate and the like are preferable.

The proportion of the (D) carboxylate in the non-volatile content of the aqueous composition of the present invention is preferably 0.1 to 6% by weight, preferably 0.2 to 5% by weight. When the content ratio of the carboxylate is in this range, it is possible to promote the condensation reaction of the alkoxyl group of the component to be blended in the (A) silicone emulsion to prepare a stronger coating film, and (A) the silicone. It is possible to maintain storage stability in which the components blended in the emulsion are less likely to aggregate.

The (E) cellulose nanofiber of the present invention is a cellulose microfibril, which is a compound in which cellulose molecular chains are bonded by hydrogen bonds and intermolecular forces, or an aggregate in which a plurality of cellulose microfibrils are aggregated as the minimum unit. It has a diameter of about 1 nm to 800 nm. The length thereof ranges from 100 nm to 8 μm. Generally, cellulose nanofibers are obtained by mechanically defibrating a naturally occurring cellulose structure.

The cellulose nanofibers have a thickness of several nm to several hundred nm, and have a large specific surface area and a large number of free hydroxyl groups (not bonded to others) existing on the surface. By blending the cellulose nanofibers, the affinity with the hydroxyl groups generated by the hydrolysis of the alkoxysilane or the surfaces of various base materials is good, so that a substantially uniform and transparent coating film can be produced. , The mechanical strength of the coating film can be improved. The cellulose nanofibers can be blended in the form of powder, but are preferably blended in the form of a slurry, paste, gel or the like which is an aqueous dispersion. With such an aqueous dispersion, the cellulose nanofibers are more easily dispersed, and the concentration of the cellulose nanofibers becomes uneven when the coating film is formed. As commercially available products, Leocrysta (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Serish (manufactured by Daicel FineChem), cellulose nanofibers (manufactured by Daio Paper Corporation), modified cellulose nanofibers (manufactured by Nippon Paper Industries Co., Ltd.) and the like are used.

The content of the (E) cellulose nanofibers (nonvolatile content) in the non-volatile content of the aqueous composition of the present invention is preferably 0.5 to 10% by weight, preferably 1 to 5% by weight. .. When the content ratio of the cellulose nanofibers is in this range, it is possible to improve the durability of the coating film produced when the aqueous composition is applied to the surfaces of various base materials against physical impact and outdoor exposure.

The water (F) contained in the present invention is formulated separately from (a-4) water, and is composed of (A) silicone emulsion, (B) silsesquioxane, (C) fluororesin, and (. E) A solvent for uniformly dispersing cellulose nanofibers. As the water (F), any water such as purified water, ion-exchanged water, and industrial water can be used as in the case of (a-4) water. Further, trace components contained in water may also be contained within a range that does not affect the curability at the time of producing the coating film.

The water content of (F) in the aqueous composition for a coated surface of the present invention is preferably 60 to 80% by weight, preferably 65 to 78% by weight. When the water content is in this range, a coating film can be prepared so that unevenness does not occur, and since it does not contain an organic solvent, the worker performing the coating work is acutely or chronically poisoned by the organic solvent. It is possible to prevent being invaded by.

The aqueous composition of the present invention is prepared by mixing each component and then stirring at room temperature. When blending (A) silicone emulsion, (B) silsesquioxane, (C) fluororesin, (E) cellulose nanofiber, and (F) water, each component is blended in an arbitrary order. It can be mixed at the same time.

Then, the aqueous composition for a coated surface of the present invention can be added with an ultraviolet absorber, a viscosity regulator, a colorant, a preservative, a pH regulator and the like, if necessary.

The water-based composition for a coated surface of the present invention preferably uses glass, resin, metal, ceramics, or the like as a target base material.

The method for treating each base material with the aqueous composition for a coated surface of the present invention is not particularly limited, and may be treated with a spin coat, a dip coat, a roll coat, a flow coat, a spray coat, or the like, or a sponge or cloth. It may be processed by hand painting using a jig such as. After that, a coating film can be formed by naturally drying the alcohol used as a solvent, and post-treatment by heat drying is not required.

Hereinafter, examples of the present invention will be specifically described. The present invention is not limited to the following examples.

(Adjustment example 1)
Methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name: KBM13) 136 g, methanol 20 g and methyltrichlorosilane so as to have a hydrochloric acid concentration of 20 ppm in a flask equipped with a stirrer, a heating device, a reflux cooling device and a dropping funnel. 10 g of water was gradually added dropwise with a dropping funnel while charging and stirring. Then, the reaction was continued for 2 hours at a reflux temperature of about 70 ° C. to carry out a hydrolysis condensation reaction. After the reaction, unreacted water and the like were separated and a volatile solvent such as methanol was distilled off under reduced pressure to obtain 94 g of an organopolysiloxane containing unreacted trimethoxysilane. The polymerization average molecular weight of the obtained organopolysiloxane was 3000. Then, to 90 g of the organopolysiloxane containing the unreacted trimethoxysilane, 3 g of POE (15) cetyl ether, which is a nonionic surfactant, is added and heated to about 40 ° C., and then a homomixer is used. The mixture was stirred at 5000 rpm, 93 g of warmed water was gradually added thereto, and the mixture was stirred at 40 to 45 ° C. for 30 minutes to obtain a 50% aqueous aqueous solution of silicone emulsion (A-1).

(Example 1)
Silicone emulsion (A-1) 5.0% by weight, silsesquioxane dispersion (manufactured by Konishi Chemical Industry Co., Ltd .: SP-1120, average particle size: 20 nm, non-volatile content 10% by weight) (B-1) 5% by weight %, Fluorine resin (AGC: AsahiGuard AG-E082, non-volatile content 20% by weight) (C-1) 8% by weight, tris (2-ethylhexane) bismuth (borchers) as carboxylate: Borchi (registered trademark) ) Kat24) (D-1) 0.01% by weight, cellulose nanofiber aqueous dispersion (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution product) 15% by weight, water 66.99% by weight coated surface An aqueous composition was obtained.

(Example 2)
Silicone emulsion (A-1) 4.0% by weight, silsesquioxane dispersion (manufactured by Konishi Chemical Industry Co., Ltd .: SP-1120, average particle size: 20 nm, non-volatile content 10% by weight) (B-1) 10% by weight %, Fluororesin (AGC: AsahiGuard AG-E550D, non-volatile content 30% by weight) (C-2) 8% by weight, dibutyltin dilaurate as carboxylate (Borchers: Borchi® LH10) (D -2) An aqueous composition for a coated surface consisting of 0.5% by weight, cellulose nanofiber aqueous dispersion (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution product) 15% by weight, and 62.5% by weight of water. Obtained.

(Example 3)
Silicone emulsion (A-1) 3.0% by weight, silsesquioxane dispersion (Asahi Kasei Wacker Silicone Co., Ltd .: ADM6300E, average particle size: less than 20 nm, non-volatile content 35% by weight) (B-2) 4% by weight , Fluorine resin (AGC: AsahiGuard AG-E550D, non-volatile content 30% by weight) (C-2) 16% by weight, tris (2-ethylhexane) bismuth as carboxylate (borchers: Borchi (registered trademark)) Kat24) (D-1) 0.03% by weight, silicone nanofiber aqueous dispersion (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution) 5% by weight, water 71.97% by weight for coated surface The system composition was obtained.

(Example 4)
Silicone emulsion (A-1) 10.0% by weight, silsesquioxane dispersion (Asahi Kasei Wacker Silicone Co., Ltd .: ADM6300E, average particle size: less than 20 nm, non-volatile content 35% by weight) (B-2) 8% by weight , Fluorine resin (AGC: AsahiGuard AG-E550D, non-volatile content 30% by weight) (C-2) 3.5% by weight, dibutyltin dilaurate as carboxylate (Bochers: Borchi® LH10) ( D-2) Water-based composition for coated surface consisting of 0.4% by weight, cellulose nanofiber aqueous dispersion (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution), 10% by weight, and 68.1% by weight of water. Got

(Comparative Example 1)
Silicone emulsion (A-1) 3.0% by weight, fluororesin (AGC: AsahiGuard AG-E082, non-volatile content 20% by weight) (C-1) 8% by weight, tris (2-ethyl) as carboxylate (Hexane) Bismus (Borchers: Borchi (registered trademark) Kat24) (D-1) 0.01% by weight, cellulose nanofiber aqueous dispersion (Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution) 5% by weight An aqueous composition for a coated surface composed of% and 83.99% by weight of water was obtained.

(Comparative Example 2)
Silicone emulsion (A-1) 4.0% by weight, silsesquioxane dispersion (manufactured by Konishi Chemical Industry Co., Ltd .: SP-1120, average particle size: 20 nm, non-volatile content 10% by weight) (B-1) 10% by weight %, Dibutyltin dilaurate (manufactured by Borchers: Borchi® LH10) (D-2) 0.5% by weight as carboxylate, cellulose nanofiber aqueous dispersion (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight % Aqueous solution product) An aqueous composition for a coated surface composed of 10% by weight and 75.5% by weight of water was obtained.

(Comparative Example 3)
Silicone emulsion (A-1) 1.0% by weight, silsesquioxane dispersion (Asahi Kasei Wacker Silicone Co., Ltd .: ADM6300E, average particle size: less than 20 nm, non-volatile content 35% by weight) (B-2) 8% by weight , Fluorine resin (AGC: AsahiGuard AG-E550D, non-volatile content 30% by weight) (C-2) 3.5% by weight, cellulose nanofiber aqueous dispersion (Daiichi Kogyo Seiyaku Co., Ltd .: Leocrysta, 2% by weight aqueous solution) Product) An aqueous composition for a coated surface composed of 15% by weight and 72.5% by weight of water was obtained.

(Comparative Example 4)
Silicone emulsion (A-1) 3.0% by weight, silsesquioxane dispersion (Dow Toray Co., Ltd .: 87 ADDITIVE, average particle size: 1,000 nm, non-volatile content 40% by weight) (B-3) 10 Weight%, fluororesin (AGC: AsahiGuard AG-E550D, non-volatile content 30% by weight) (C-2) 4% by weight, tris (2-ethylhexane) bismuth (borchers) as carboxylate: Borchi (registered) A water-based composition for a coated surface was obtained, which consisted of 0.02% by weight of Kat24) (D-1) and 82.98% by weight of water.

(Creation of test piece)
First, an automobile paint made of an acrylic-melamine resin was baked and coated on a piece of galvanized steel sheet for an automobile body in a laminated form of a base coat and a top coat to prepare a coated plate. Then, the water-based composition according to Examples 1 to 4 and the water-based composition according to Comparative Examples 1 to 4 are treated on a base material using a sponge so that unevenness does not remain with another new cloth. I wiped it up. It was air-dried and cured at room temperature for 1 day at room temperature to prepare a test piece with a coating film.

Durability, water repellency, stain resistance and oil resistance are evaluated using the test pieces with these coating films, and the workability when the aqueous composition is treated on the base material and the aqueous composition. We evaluated its own environmental friendliness. Regarding workability, those that do not have a problem in performance even if they are finished and wiped immediately after processing are evaluated as 〇, and those that require a certain drying time after processing are evaluated as ×, and the work time can be shortened from the viewpoint of work efficiency. The aqueous composition was judged to be good.
The durability against physical impact such as scratches and outdoor exposure was tested for scratch resistance and weather resistance, and evaluated by the gloss and contact angle of the test piece, respectively.

(Scratch resistance)
With a sponge to which a load of 3 kg was applied to the base material, 300 reciprocations were carried out with a cleaning solution consisting of sodium carbonate and sodium dodecylbenzenesulfonate, and changes in glossiness and contact angle were confirmed.

(Weatherability)
Using SUV-161 manufactured by Iwasaki Electric Co., Ltd., ^{let it pass for 250 hours under the conditions of ultraviolet intensity 100 mW / cm 2} , black panel temperature 63 ° C, humidity 50%, irradiation / condensation cycle (with spray at the time of condensation), and contact with glossiness. The change in the corner was confirmed.

The glossiness was evaluated by measuring the glossiness at 60 ° using GLOSS METER manufactured by Nippon Denshoku Co., Ltd. at the initial stage immediately after the preparation of the test piece, after the scratch resistance test, and after the accelerated weather resistance test.

After the scratch resistance test and the accelerated weather resistance test, the gloss of the surface of the test piece is measured at an angle of 60 °, and the gloss maintenance ratio is calculated based on the following general formula (2) using the initial gloss value. did.
Gloss retention rate (%) = (Initial gloss value-Gloss value after each test) / Initial gloss value x 100 ... (2)
A coating film having a gloss retention rate of 95% or more and 100% or less is evaluated as ◯, a coating film having a gloss retention rate of 90% or more and less than 95% is evaluated as Δ, and a coating film having a gloss retention rate of less than 90% is evaluated as good. It was judged.

Regarding the contact angle, the contact angle with water on the surface of the coating film was determined using a DropMaster manufactured by Kyowa Interface Science Co., Ltd. at the initial stage immediately after the preparation of the test piece, after the scratch resistance test, and after the accelerated weather resistance test. Five points were measured by the θ / 2 method, and the average value was obtained. Those having a contact angle of 100 ° or more were evaluated as ◯, those having a contact angle of 95 ° or more and less than 100 ° were evaluated as Δ, and those having a contact angle of less than 95 ° were evaluated as ◯, and the coating film having a ◯ was judged to be good.

(Stain resistance evaluation)
A liquid in which carbon black and clay substances were dispersed in ion-exchanged water was used as artificial pollution. This artificial contaminant was sprayed onto the test piece, the artificial contamination was washed away with tap water, and the condition of the test piece was visually confirmed. Similarly, when the amount of contaminants is clearly less than that of the untreated test piece of the aqueous composition tested with the artificial contaminant, 〇, the contaminants are attached but not yet. When the number of test pieces was less than that of the test piece in the constructed state, it was evaluated as Δ, and when the amount of contaminants was the same as that of the test piece in the unconstructed state, it was evaluated as ×, and the coating film of ○ was judged to be good.

(Oil resistance evaluation)
Dodecane colored blue was used as the model oil. The model oil was put in a container, and the test piece was taken in and out of the container to visually evaluate the degree of adhesion of the oil to the test piece. When the oil was taken out, it was evaluated as ◯ when the oil was immediately pulled from the test piece and did not adhere, and when the oil was wet and spread and remained on the test piece, it was evaluated as ×, and the coating film of ◯ was judged to be good.

The compositions of the obtained aqueous compositions are shown in Table 1, and the results of physical property evaluation of the coating film prepared by those compositions are shown in Table 2.

As shown in Table 2, in the coating film prepared by the aqueous composition of Examples 1 to 4, the gloss and contact angle can be maintained even after the scratch resistance test and the weather resistance test, and the durability is excellent. It turned out that. It was also found that it was excellent in stain resistance and oil resistance. On the other hand, with respect to Comparative Examples 1 to 4 in which any of (B) silsesquioxane, (C) fluororesin, (E) cellulose nanofiber, and (D) carboxylate was not blended, durability. In at least one item of stain resistance and oil resistance, there was an item inferior to that of the examples, and it was not said that it was good because it did not reach the level that can be comprehensively marketed.

In this way, (A) silicone emulsion, (B) silsesquioxane, (C) fluororesin, (D) carboxylate, (E) cellulose nanofibers, and (F) water are both used. It was found that the blended aqueous composition can produce a coating film having excellent durability against physical impact such as scratches and outdoor exposure, stain resistance against dirt, and oil resistance.

Claims (3)

(A-1) Alkoxysilane represented by the following general formula (1) and
X _n −Si− (OY) _4-n・ ・ ・ ・ ・ ・ ・ ・ ・ (1)
(In the formula, X is an alkyl group having 1 to 18 carbon atoms, Y is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 3 carbon atoms).
(A-2) Organopolysiloxane, which is a hydrolysis condensate of the alkoxysilane,
(A-3) Nonionic surfactant and
(A-4) Water-containing (A) silicone emulsion and
(B) Silsesquioxane having an average particle size of 10 to 200 nm and
(C) Fluororesin and
(D) Carboxylate and
(E) Cellulose nanofibers and
(F) A water-based composition for a coated surface, which comprises water. The aqueous composition for a coated surface according to claim 1, wherein the carboxylate is at least one selected from dibutyltin dilaurate and tris (2-ethylhexane) bismuth. The aqueous composition for a coated surface according to claim 1 or 2, wherein the silsesquioxane is spherical.