JP2022096138A - Glass water repellent agent - Google Patents

Abstract

To provide a glass water repellent agent which can shorten a period required for coating construction to a glass of a vehicle, and which can achieve a sufficient water repellent performance even under a poor construction condition such as, in a low temperature in which a reaction speed is relatively slow, in a high temperature in which the water repellent component adheres due to heat.SOLUTION: A glass water repellent agent is configured so that, an alkylsilane compound having an alkoxy group, a dimethyl polysiloxane having an OH group on each of both terminals of a molecular chain, a catalyst, and functional fine particles, are diluted by a volatile solvent. According to necessity, dimethyl polysiloxane is added. The functional fine particles are formed of two kinds of fine particles which are, organic fine particles and inorganic fine particles. The organic fine particles included in the functional fine particles are coarse relative to the inorganic fine particles.SELECTED DRAWING: None

Description

INDUSTRIAL APPLICABILITY The present invention is used to form a water-repellent film on a glass surface such as a windshield or a mirror of a vehicle in order to prevent raindrops from adhering to the glass surface and reducing visibility. It is related to the glass water repellent.

Conventionally, water repellents used to impart water repellency to the glass surface of a vehicle have been known. Prior documents also propose water repellents and coating compositions for glass (for example, Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 2009-137775 Japanese Unexamined Patent Publication No. 2016-169307

Among the above-mentioned prior documents, Patent Document 1 describes a water repellent for glass containing an amino-modified polysiloxane having an OR group (R is a hydrocarbon having 1 to 6 carbon atoms) at the end of the main chain. .. It is said that this water repellent for glass does not require drying or filming after application, exhibits water repellency (initial water repellency) immediately after application, and can be used even if raindrops remain on the glass surface. There is. However, as a result of investigation, it has been found that this water repellent for glass tends to have poor water repellent durability (water repellent durability) after application.

Patent Document 2 describes a coating composition obtained by diluting a silane compound, dimethylpolysiloxane having a silanol group (SiOH group) at both ends of a molecular chain, and a catalyst with a volatile solvent. In this coating composition, since dimethylpolysiloxane has silanol groups at both ends of the molecular chain, the adhesion to the glass surface is enhanced, and the initial repellent is stable even in various construction environments such as humidity and temperature. It is said that water-based and water-repellent persistence are exhibited. However, as a result of the investigation, under low temperature conditions where the construction conditions are bad, the time required for the construction (coating process) tends to be long, and the reactivity between dimethylpolysiloxane having silanol groups at both ends of the molecular chain and the glass surface is high. It was found that there was a tendency for the water repellency to decrease and the water repellency to become difficult to develop.

Therefore, according to the coating composition described in Patent Document 2, the inventor of the present application has improved the tendency of the water repellent for glass of Patent Document 1 to have poor water repellency sustainability, and has been stable at the initial stage. The present invention has been completed by paying attention to the fact that it exhibits the characteristics of exhibiting water repellency and water repellency.

That is, the present invention utilizes the excellent properties of the coating composition described in Patent Document 2 regarding the initial water repellency and the durability of water repellency as they are, and the characteristics of the functional fine particles with respect to the glass water repellent agent (chemical solution). Glass water repellency that provides fully satisfactory initial water repellency and water repellency not only in low temperatures with poor construction conditions but also in high temperatures where water repellent components stick due to heat. The purpose is to provide the agent. Another object of the present invention is to provide a glass water repellent agent capable of shortening the time required for construction for forming a water repellent coating film on a glass surface.

In this item, the modified silicone oil "dimethylpolysiloxane having OH groups at both ends of the molecular chain" is abbreviated as "OH silicone", and the straight silicone oil "dimethylpolysiloxane" is referred to as "dimethylpolysiloxane" as it is. Described as "siloxane".

The glass water repellent agent according to the present invention is a glass water repellent agent for forming a water repellent film on a glass surface, and comprises an alkylsilane compound having an alkoxy group, OH silicone, a catalyst, and functional fine particles. , Diluted with a volatile solvent.

In the present invention, the silane compound represented by the following general formula (1) can be preferably adopted as the alkylsilane compound having an alkoxy group.
(R ₁ O) _n Si (R ₂ ) _4-n ... (1)
However, n = 1 or n = 2, R ₁ is an alkyl group having C = 1 to 3 carbon atoms, and R ₂ is an alkyl group having C = 1 or C = 3 carbon atoms.

In the alkylsilane compound having an alkoxy group, the alkoxy group ( _R1O ) causes a hydrolysis / condensation reaction (dehydration condensation reaction) with a hydroxyl group (OH group) on the glass surface. This hydrolysis / condensation reaction is promoted by the action of a catalyst, and an alkylsilane compound having an alkoxy group forms a water-repellent film showing high water repellency immediately after application (immediately after construction). Since this water-repellent film exhibits excellent slipperiness, friction caused by the wiper and friction when rubbed with sand stains attached are reduced, and deterioration of the water-repellent film is also reduced.

Examples of the alkylsilane compound having an alkoxy group include trimethylmethoxysilane, dimethyldimethoxysilane, triethylmethoxysilane, diethyldimethoxysilane, trimethylethoxysilane, dimethyldiethoxysilane, triethylethoxysilane, diethyldiethoxysilane, and trimethylpropoxysilane. Examples thereof include dimethyldipropoxysilane, triethylpropoxysilane, and diethyldipropoxysilane, of which dimethyldimethoxysilane is most preferable. As the alkylsilane compound having an alkoxy group, one kind of each of the above-mentioned alkylsilane compounds may be used, or two or more kinds may be used in combination.

In the present invention, the OH silicone enhances the adhesion of the water-repellent film to the glass surface, improves the water repellency of the water-repellent film formed on the glass surface, and also causes droplets to fall on the water-repellent film. Was added with the intention of imparting.

In the present invention, the catalyst has a function of reducing the activation energy required for the alkylsilane compound having an alkoxy group or the OH group of OH silicone to dehydrate and condense with the OH group existing on the glass surface. Therefore, by using a catalyst together, the reactivity of the alkylsilane compound or OH silicone having an alkoxy group under high humidity conditions to the glass surface is maintained, and the water repellency and water repellency sustainability immediately after construction are improved. .. Catalysts include inorganic acids such as sulfuric acid, hydrochloric acid, nitrate and phosphoric acid, sulfonic acids such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid and paratoluenesulfonic acid, and carboxylic acids such as acetic acid, citric acid and formic acid. It can be arbitrarily selected from acids. For catalysts other than acid catalysts, the alkali catalyst can be arbitrarily selected from alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkaline earth metal water such as calcium hydroxide and barium hydroxide. It can be arbitrarily selected from oxides, or it can be arbitrarily selected from hydroxides of tetraalkylammoniums such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and ammonia, methylamine, and dimethylamine. , Trimethylamine, monoethanolamine, diethanolamine, triethanolamine, and the like, and triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, etc. as metal catalysts. It can be arbitrarily selected from an organic aluminum compound and a metal alkoxide such as a titanium alkoxide, an iron alkoxide, and an organic tin alkoxide. As the catalyst, one of the above-mentioned various catalysts may be used, or two or more of them may be used in combination, but particularly preferable results can be obtained by using an acid catalyst.

In the present invention, the volatile solvent is useful for maintaining the coatability of an active ingredient such as an alkylsilane compound having an alkoxy group or OH silicone on a glass surface.

In the present invention, the functional fine particles are added to improve the wettability of the glass water repellent (chemical solution) on the glass surface and to improve the workability at the time of wiping. At high temperatures, the chemical solution can be uniformly applied by improving the wettability of the chemical solution on the glass surface. In addition, at low temperatures, there is a concern that the water repellency may decrease due to wiping before the volatile solvent volatilizes, but the addition of functional fine particles improves the dryness and improves the water repellency even at low temperatures. be able to. The functional fine particles have an action of suppressing the aggregation of water-repellent components such as a volatile solvent, an alkylsilane compound, and OH silicone on the glass surface by supporting a volatile solvent between the fine particles. This action improves the wettability of the glass water repellent to the glass surface, and the improved wettability increases the air contact area, improves the dryness, and improves the workability during wiping. ..

In the present invention, it is desirable that the kinematic viscosity of OH silicone at 25 ° C. is 31 cSt or more. It is known that the adhesion of OH silicone to the glass surface changes depending on its kinematic viscosity. Considering this, it is desirable that the kinematic viscosity of OH silicone at 25 ° C is 31 cSt or more, and if the kinematic viscosity at 25 ° C is lower than 31 cSt, the adhesion to the glass surface becomes too poor and the initial repellent immediately after construction. It may be difficult to obtain water-based or water-repellent sustainability. When OH silicone having a kinematic viscosity of 31 cSt or more at 25 ° C. is added, excellent initial water repellency and water repellency durability equivalent to those of the coating composition described in Patent Document 2 above can be obtained. Be done. The kinematic viscosity of OH silicone can be increased or decreased by mixing commercially available OH silicones with different kinematic viscosities, and the kinematic viscosity at 25 ° C. as an OH silicone mixture having different kinematic viscosities is 31 cSt. All you need is.

In the present invention, the amount of OH silicone added is preferably 0.05 to 20 wt%, preferably 1 to 10 wt%. If the amount added is less than 0.05 wt%, the water-repellent performance of the coating film deteriorates, and if it exceeds 20 wt%, the workability at the time of wiping tends to deteriorate. When the blending amount is 0.05 to 20 wt%, the water-repellent performance of the coating film is improved and the workability at the time of wiping is also improved.

OH silicone is available as a general industrial product, for example, trade name X-21-5841 (kinematic viscosity at 25 ° C. 30 cSt), product name KF9701 (kinematic viscosity at 25 ° C. 60 cSt), manufactured by Shin-Etsu Chemical Industry Co., Ltd. Product names X96-723, YF3057, YF3800, YF3802, YF3807, YF3807, YF3905, DMS-S12, DMS-S14, DMS-S15, DMS manufactured by Gelest, Inc. -S21, DMS-S27, DMS-S31, DMS-S32, DMS-S33, DMS-S35, DMS-S42, DMS-S45 and the like can be mentioned. One kind of these raw materials may be used, or two or more kinds may be used in combination.

In the present invention, it is desirable that the functional fine particles are two types of fine particles, an organic fine particle and an inorganic fine particle. As described above, the functional fine particles are added to improve the wettability of the glass water repellent (chemical solution) on the glass surface and to improve the workability at the time of wiping, and the chemical solution gets wet on the glass surface at high temperature. By improving the properties, it becomes possible to apply the chemical solution uniformly, and at low temperatures, there is a concern that the water repellency may decrease due to wiping before the volatile solvent volatilizes, but functional fine particles are added. As a result, the drying property is improved, and the water repellency can be improved even at a low temperature. When the functional fine particles are composed only of organic fine particles, the workability of wiping tends to be deteriorated especially at high temperature, and this phenomenon is remarkable when thermoplastic organic fine particles are used. On the other hand, if the functional fine particles are composed of only inorganic fine particles, the friction at the time of wiping becomes too large and the durability of the film tends to decrease. By using a combination of organic fine particles and inorganic fine particles in combination, it is considered that the shortcomings of each can be compensated for and performance that is not shown by itself can be obtained.

As organic fine particles, polyethylene, silicone, polytetrafluoroethylene (PTFE), polyethylene vinegar copolymer resin, wax, polypropylene, cellulose acetate butyrate, silicone rubber, microcrystalline cellulose, nylon, chitosan, polystyrene, benzoguanamine melamine. Resin powders such as condensates, acrylics and phenols can be used.

As inorganic powders, alumina, silica gel, aluminum silicate, zeolite, bentonite, talc, montmorillonite, diatomaceous earth, smectite, kaolinite, cerium oxide, zirconium oxide, zirconium silicate, silicon carbide, titanium oxide, aluminum tripolyphosphate, Examples thereof include powders such as aluminum hydroxide, barium sulfate and calcium silicate, spherical fine powders such as spherical silica, spherical alumina and spherical silica gel, and hollow fine powders such as spherical hollow silica and hollow glass beads. Further, inorganic fine particles surface-treated with another metal oxide or organic substance can also be used.

Wax powder is particularly preferable for organic fine particles, and in addition to imparting workability during application, improvement in slipperiness during wiper operation can be expected. As the inorganic fine particles, those mainly containing SiO ₂ such as hydrous silicic acid as a main component are preferable. These have the effect of removing stains such as oil when they are attached to the glass surface.

In the present invention, it is desirable that the total amount of the functional fine particles added is 0.1 to 5 wt%. If the total amount of functional fine particles added is less than 0.1 wt%, it is difficult to obtain the effects of improving the wettability of the chemical solution on the glass surface and improving the workability during wiping, and if it exceeds 5 wt%, conversely, when wiping. Not only does the workability deteriorate, but also the durability of the coating film deteriorates. The preferable total addition amount of the functional fine particles is 0.5 to 2 wt%.

In the present invention, the organic fine particles contained in the functional fine particles are coarser than the inorganic fine particles contained in the functional fine particles, the average particle system of the organic fine particles is 20 μm or less, and the average particle system of the inorganic fine particles is 5 μm. It is desirable that it is as follows. When this configuration is adopted, the functional fine particles form a bimodal (bimodal) system consisting of coarse organic fine particles and fine inorganic fine particles, and two types of particles having different particle sizes are wiped off. Sometimes it helps to increase the friction between the cloth and the surface to which the chemical solution is applied, and helps to improve the workability at the time of wiping. Here, the "bimodal system composed of coarse organic fine particles and fine inorganic fine particles" is a graph showing the particle size distribution of fine particles, in which two are coarse organic fine particles and fine inorganic fine particles. It refers to a system that is distributed in the form of peaks. In the present invention, the particle size does not necessarily have to be limited as described above.

In the present invention, it is desirable that dimethylpolysiloxane is diluted in a volatile solvent together with an alkylsilane compound having an alkoxy group, OH silicone, a catalyst, and functional fine particles. Didimethylpolysiloxane is added for the purpose of improving water repellency. Although the kinematic viscosity of dimethylpolysiloxane is not particularly limited, it is desired that the kinematic viscosity at 25 ° C. is 30 cSt or less from the viewpoint of compatibility with a volatile solvent. Regarding this point, it is desired that the kinematic viscosity at 25 ° C. is 30 cSt or less from the “relationship with the boiling point and type of the polar solvent contained in the volatile solvent” described later.

In the present invention, it is desirable that the amount of dimethylpolysiloxane added is less than 10 wt%. When the amount of dimethylpolysiloxane added is 10 wt% or more, not only the workability at the time of wiping is lowered, but also the durability of the water-repellent film is lowered. One type of dimethylpolysiloxane may be used, or two or more types may be used in combination.

In the present invention, it is desirable that the volatile solvent contains at least one kind of polar solvent having a boiling point of 150 ° C. or higher, and the amount of the polar solvent added to the volatile solvent is 1 to 10 wt%. The volatile solvent is useful for maintaining the coatability (workability) of a water-repellent component such as an alkylsilane compound or OH silicone on the glass surface.

It is desirable to use a volatile solvent that is not so volatile even under high temperature conditions such as summer. That is, the volatile solvent volatilizes in a short time under high temperature conditions such as in summer, and the reactivity of the active ingredient such as the above-mentioned alkylsilane compound having an alkoxy group or OH silicone of the molecular chain to the glass surface is too high. Therefore, a situation may occur in which the active ingredient cannot be uniformly applied, and as a result, a situation may occur in which sufficient water repellency cannot be obtained. Therefore, as in the present invention, when the volatile solvent contains one or more polar solvents (volatile holding agents) having a boiling point of 150 ° C. or higher, the volatility of the volatile solvent is suppressed and the glass surface of the active ingredient is used. It becomes possible to uniformly apply an active ingredient such as an alkylsilane compound or dimethylporosiloxane without inhibiting the condensation reaction with the above, which helps to exert sufficient water repellency. On the other hand, the reactivity is low under low temperature conditions such as in winter, and if the polar solvent with a boiling point of 150 ° C or higher is wiped off before it volatilizes, the active ingredient will be scraped off by the cloth before it reacts, resulting in good repellent properties. There is also a problem that it is difficult to develop aqueous solution. Therefore, the amount of the polar solvent having a boiling point of 150 ° C. or higher is preferably 1 to 10 wt% in order to improve workability during wiping in summer and winter. If the polar solvent having a boiling point of 150 ° C. or higher is less than 1 wt%, the target component tends to stick at a high temperature, and if it exceeds 10 wt%, the performance at a low temperature is difficult to be exhibited. When the polar solvent having a boiling point of 150 ° C. or higher is 1 to 10 wt%, it is easy to improve workability at the time of wiping in summer and winter.

The polar solvent that can be adopted is not particularly limited, but for example, for ketones, diisobutyl ketone, for esters, ethyl glycol acetate, propylene glycol monomethyl ether propionate, 3-methoxy-butyl acetate, etc. 3-methoxy-3-methylbutyl acetate, ethyl-3-ethoxypropionate, butyceroacetate, benzyl alcohol for alcohols, ethylene glycol, diethylene glycol, propylene glycol, glycol ethers for glycols. For example, the trade names of Dau Chemical Co., Ltd., Dwanol TPM (tripropylene glycol methyl ether), Dwanol DPM (dipropylene glycol methyl ether), Dwanol DPnP (propylene glycol-n-propyl ether), Dwanol PnP (propylene glycol) -N-propyl ether), Dwanol PnB (propylene glycol-n-butyl ether), Dwanol DPnB (dipropylene glycol-n-butyl ether), Dwanol TPnB (tripropylene glycol-n-butyl ether), Dwanol DPMA (dipropylene glycol-n-butyl ether) Propylene glycol methyl ether acetate), Dwanol PGDA (propylene glycol diacetate), Dwanol PPH (propylene glycol phenyl ether), Dwanol DMM (dipropylene glycol dimethyl ether), and ethylene glycol tertiary butyl ether, butyl cellosolve, 3 -Methoxy-3-methyl-1-butanol, ethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, dipropylene glycol monomethyl ether and the like can also be used.

It is desirable that the volatile solvent contains at least one kind of polar solvent having a boiling point of 150 ° C. or higher, and isopropyl alcohol (IPA) can be particularly preferably used. Therefore, from the viewpoint of compatibility with isopropyl alcohol, it is desirable to use dimethylpolysiloxane having a kinematic viscosity of 30 cSt or less at 25 ° C.
In the present invention, it is also possible to add various silicone oils with the intention of improving water repellency and workability. Silicone oil can be added as needed, and the type is not particularly limited, but for example, cyclic silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil, long-chain alkyl-modified silicone oil, etc. Amino-modified silicone oil, epoxy-modified silicone oil, carboxy-modified silicone oil, carbinol-modified silicone oil, methacryl-modified silicone oil, mercapto-modified silicone oil, phenol-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, alkyl-modified Examples thereof include silicone oil, higher fatty acid ester-modified silicone oil, and fluorine-modified silicone oil.

In order to improve the water repellency, it is particularly beneficial to use dimethyl silicone oil, and in addition, cyclic silicone oil and methylhydrogen silicone oil can be particularly preferably used. Polyether-modified silicone oil and long-chain alkyl-modified silicone oil are preferable in order to improve the wettability of the contained components on the glass surface and the workability at the time of wiping. One kind of these silicone oils may be used, or two or more kinds may be mixed and used.

The glass water repellent according to the present invention includes water, surfactants, oils, pigments, dyes, fragrances, chelating agents, antibacterial agents, antiviral agents, preservatives, resins and thickeners as long as the purpose is not impaired. , A pH adjuster, a UV absorber, an IR absorber, an insect repellent, and the like can be appropriately blended.

As described above, according to the present invention, excellent characteristics regarding initial water repellency and water repellency sustainability after construction are exhibited, not only the time required for construction can be shortened, but also low temperature with poor construction conditions is exhibited. Underneath, of course, it is possible to provide a glass water repellent agent that can obtain sufficiently satisfactory initial water repellency and water repellency even under high temperature where the water repellent component sticks due to heat. Become

Samples of Examples 1 to 7 and Comparative Examples 1 to 4 were prepared by the methods shown below.

Example 1
A solution obtained by diluting 70 g of IPA (isopropyl alcohol) with 0.5 g of H ₂ SO ₄ (sulfuric acid) and 3 g of a volatilization retaining agent (polar solvent) having a boiling point of 150 ° C. or higher is OH having a kinematic viscosity of 60 cSt at 25 ° C. By adding 1.5 g of silicone (dimethylpolysiloxane having OH groups at both ends) and 1.5 g of dimethyldimethoxysilane, 19.5 g of IPA dispersed with 4 g of inorganic fine particles is added, and the mixture is sufficiently stirred. Samples were prepared.

Example 2
To a solution obtained by diluting 70 g of IPA with 0.5 g of H ₂ SO ₄ and 3 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 0.5 g of OH silicone having an kinematic viscosity of 30 cSt at 25 ° C and 60 cSt of kinematic viscosity at 25 ° C. 0.5 g of OH silicone and 0.8 g of dimethyldimethoxysilane were added, and 3 g of inorganic fine particles were dispersed in 21.7 g of IPA, and the sample was prepared by stirring sufficiently.

Example 3
To a solution obtained by diluting 70 g of IPA with 0.5 g of H ₂ SO ₄ and 1.5 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 1.5 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C. and dimethyldimethoxysilane 1. A sample was prepared by adding 5 g, adding 3 g of organic fine particles dispersed in 22 g of IPA, and stirring sufficiently.

Example 4
To a solution obtained by diluting 70 g of IPA with ₁ g of H ₂ SO and 1.5 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 1.5 g of OH silicone and 1.5 g of dimethyldimethoxysilane having a kinematic viscosity of 60 cSt at 25 ° C. are added. The sample was prepared by adding a mixture of 6 g of inorganic fine particles and 3 g of organic fine particles in 15.5 g of IPA and stirring sufficiently.

Example 5
To a solution obtained by diluting 70 g of IPA with 0.5 g of H ₂ SO ₄ and 3 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 1.5 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C. and 2 g of dimethyldimethoxysilane are added. , 1 g of inorganic fine particles and 0.5 g of organic fine particles were dispersed in 21.5 g of IPA, and the sample was prepared by sufficiently stirring.

Example 6
To a solution obtained by diluting 70 g of IPA with 0.5 g of H ₂ SO ₄ and 3 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 1.5 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C. and 2 g of dimethyldimethoxysilane are added. , A mixture of 0.75 g of inorganic fine particles and 1.25 g of organic fine particles was added to 21 g of IPA, and the sample was prepared by sufficiently stirring.

Example 7
In a solution obtained by diluting 70 g of IPA with 0.75 g of H ₂ SO ₄ and 2 g of a volatilization retainer having a boiling point of 150 ° C. or higher, 2 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C, 1 g of dimethyldimethoxysilane and dynamic at 25 ° C. Add 1.5 g of dimethylpolysiloxane (dimethylsilicone oil) having a viscosity of 10 cSt, add 1.25 g of inorganic fine particles and 0.5 g of organic fine particles dispersed in 21 g of IPA, and stir well. The sample was prepared by.

Comparative Example 1
A sample was prepared by adding 2.5 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C to a solution obtained by diluting 3 g of a volatile fixative having a boiling point of 150 ° C or higher with 94.5 g of IPA and stirring sufficiently. ..

Comparative Example 2
To a solution obtained by diluting 0.2 g of a 76% formic acid aqueous solution with 96.8 g of IPA, add 1.0 g of OH silicone having a kinematic viscosity of 60 cSt at 25 ° C. and 2.0 g of amino-modified silicone, and stir well. The sample was prepared by.

Comparative Example 3
A sample was prepared by sufficiently stirring a solution obtained by diluting ₁ g of H ₂ SO 41 with 94 g of IPA and adding 5 g of dimethyl silicone oil having a kinematic viscosity of 10 cSt at 25 ° C.

Comparative Example 4
To a solution obtained by diluting 93 g of IPA with H ₂ SO ₄ 0.5 and 5 g of a volatilization retaining agent having a boiling point of 150 ° C. or higher, 0.5 g of OH silicone having a kinematic viscosity of 30 cSt at 25 ° C. and 1 g of dimethylmethoxysilane were added. Samples were prepared by stirring the material well.

Evaluation method The test plate was made by thoroughly cleaning, polishing, and degreasing the rear glass surface of the Lafesta brand name manufactured by Nissan Motor Co., Ltd. The performance of the samples obtained in Examples 1 to 7 and Comparative Examples 1 to 4 for this test plate was evaluated.

The method of applying the sample to the test plate in the environment of high temperature (50 ° C.) and low temperature (2 ° C.) and the evaluation method are described individually for each of the following evaluation items.

Workability When 3 g of each sample was dropped and immediately wiped off with a dry cotton towel, the work feeling was evaluated in the following three stages.
◯: Can be wiped with a light force, and the entire glass surface after wiping is transparent.
Δ: The glass surface can be made transparent by applying a little force or changing the surface of the cotton towel when wiping.
×: The chemical solution sticks to the glass surface and cannot be wiped off.

Water repellency 3 g of each sample was dropped, immediately wiped off with a dry cotton towel, and then dried for 30 minutes. Then, the water-repellent state was visually evaluated in the following three stages.
◯: The water splashed in the shower immediately becomes water droplets and flows down.
Δ: The water splashed in the shower gets wet and spreads in a surface shape, and then flows down in the form of water droplets.
×: The water splashed in the shower gets wet and spreads in a plane, and flows down.

Abrasion durability (water repellent durability)
3 g of each sample was dropped, immediately wiped off with a dry cotton towel, and then dried for 30 minutes. Then, the durability of the water-repellent film formed on the glass plate was evaluated in the following three stages by polishing the glass plate using the trade name "Glass Compound Z" manufactured by Soft99 Corporation.
◯: Even if polishing is performed 5 times or more, the glass surface does not become a wet surface and water droplets are formed.
Δ: A partially wet surface is formed when polishing 5 times or more.
X: A wet surface is generated after 5 round trips or less / It is a wet surface as a matter of course.

Table 1 shows the compounding components, the compounding amount (g), and the evaluation results used in the samples of Examples 1 to 7 and Comparative Examples 1 to 4. Further, the OH silicone corresponding to the functional group equivalent of 500 g / mol listed in Table 1 has a trade name X-21-5841 (kinematic viscosity at 25 ° C.) manufactured by Shin-Etsu Chemical Industry Co., Ltd., which is available as a general industrial product. Shin-Etsu Chemical Industry Co., Ltd., which adopts 30 cSt, a specific density of 0.97 at 25 ° C, and a viscosity of 1.404 at 25 ° C) and is compatible with a functional group equivalent of 1500 g / mol, is also available as a general industrial product. The trade name KF9701 (kinematic viscosity 60 cSt at 25 ° C., specific density 0.977 at 25 ° C., refractive index 1.404 at 25 ° C.) was adopted.

In Table 1, OH silicone indicates "dimethylporosiloxane having OH groups at both ends", silane compound indicates "alkylsilane compound having an alkoxy group", and the volatilization retaining agent is a polar solvent having a boiling point of 150 ° C. or higher. IPA indicates isopropyl alcohol and H ₂ SO ₄ indicates sulfuric acid.

OH silicone having a functional group equivalent of 500 g / mol has a trade name of X-21-5841 manufactured by Shin-Etsu Chemical Industry Co., Ltd. (kinematic viscosity at 25 ° C., kinematic viscosity: 30 cSt, specific gravity at 25 ° C., 0.97, refraction at 25 ° C. 1. OH silicone having a functional group equivalent of 1500 g / mol, which corresponds to 404), has a trade name of KF9701 manufactured by Shin-Etsu Chemical Industry Co., Ltd. (kinematic viscosity at 25 ° C., kinematic viscosity 60 cSt, specific gravity at 25 ° C. 404).

According to Table 1, Examples 1 to 7 containing at least one or both of the inorganic fine particles and the organic fine particles are operated at high temperature and low temperature as compared with Comparative Examples 1 to 4 not containing them. Not only is it generally excellent in properties, water repellency, and wear durability, but there is no evaluation of x seen in Comparative Examples 1 to 4. In addition, in Examples 5 to 7 containing both inorganic fine particles and organic fine particles, a rating of ◯ was obtained in all of workability, water repellency, and wear durability at high temperature and low temperature. In addition, among Examples 1 to 7 containing OH silicone having a kinematic viscosity of 60 cSt at 25 ° C., in Examples 5 to 7, ○ was evaluated in all of workability, water repellency, and wear durability at high temperature and low temperature. In Examples 1 to 4, the workability, water repellency, and wear durability at high temperature and low temperature were partially evaluated as Δ, but almost the same high evaluation was obtained.
On the other hand, among Comparative Examples 1 to 4, Comparative Example 4 containing OH silicone was evaluated as ◯ in terms of water repellency and wear durability at high temperature, whereas workability at high temperature and workability at high temperature and The workability and water repellency at low temperatures are evaluated as Δ, and the wear durability is evaluated as ×. It is considered that this is because the kinematic viscosity of the OH silicone contained in Comparative Example 4 at 25 ° C. is as small as 30 cSt, so that the water repellency durability after application to the glass surface tends to be poor. Be done.

In consideration of these evaluation results, the glass water repellent agent according to the present invention is wetted at high temperature and low temperature by adding functional fine particles of at least one or both of inorganic fine particles and organic fine particles. It is considered that the property, dryness, workability and wiping workability have been improved. Further, by using OH silicone having a high average molecular weight of 25 ° C. and a kinematic viscosity of a certain value (31 sSt) or more, the adhesion of the water-repellent film to the glass surface was enhanced and the OH silicone was formed on the glass surface. It is considered that the water repellency of the water-repellent film is improved and the water-repellent film is imparted with good droplet falling property.

Claims (9)

A glass water repellent for forming a water repellent film on the glass surface.
A glass water repellent agent characterized in that an alkylsilane compound having an alkoxy group, dimethylpolysiloxane having OH groups at both ends of the molecular chain, a catalyst, and functional fine particles are diluted with a volatile solvent. .. The glass water repellent agent according to claim 1, wherein the kinematic viscosity of dimethylpolysiloxane having OH groups at both ends of the molecular chain at 25 ° C. is 31 cSt or more. The glass water repellent according to claim 1 or 2, wherein the amount of dimethylpolysiloxane having OH groups at both ends of the molecular chain is 0.05 to 20 wt%. The glass water repellent agent according to any one of claims 1 to 3, wherein the functional fine particles are two types of fine particles, an organic fine particle and an inorganic fine particle. The glass water repellent according to claim 1 or 4, wherein the total amount of the functional fine particles added is 0.1 to 5 wt%. Claimed that the organic fine particles contained in the functional fine particles are coarser than the inorganic fine particles contained in the functional fine particles, the average particle system of the organic fine particles is 20 μm or less, and the average particle system of the inorganic fine particles is 5 μm or less. 4 or the glass water repellent according to claim 5. Claims 1 to claim that dimethylpolysiloxane is diluted with an alkylsilane compound having an alkoxy group, dimethylpolysiloxane having OH groups at both ends of the molecular chain, a catalyst, and functional fine particles in a volatile solvent. The glass water repellent agent according to any one of 6. The glass water repellent according to claim 7, wherein the amount of dimethylpolysiloxane added is less than 10 wt%. One of claims 1 to 8, wherein the volatile solvent contains one or more polar solvents having a boiling point of 150 ° C. or higher, and the amount of the polar solvent added to the volatile solvent is 1 to 10 wt%. The glass water repellent described in.