JPH10226536A - Antifouling glass article having low critical tilt angle and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass article less liable to the sticking of dirt, less liable to generate streaks of dirt due to rain because dirt is easily removed by rainfall, etc., less liable to cause light scattering due to drops of water and not deteriorating transmitted and reflected images by chemically or physically fixing or sticking an organometallic compd. contg. a polyalkylene oxide group in each molecule on the surface of a glass substrate. SOLUTION: An organometallic compd. contg. a polyalkylene oxide group in each molecule, preferably a metallic alkoxide compd. or a metallic halogen compd. or its hydrolyzate is fixed or stuck on the surface of a glass substrate in the form of 0.5-20 molecular layers or a film having 0.5-80nm average thickness. The organometallic compd. is especially alkoxysilane or chlorosilane, more especially [alkoxy(polyalkyleneoxy)alkyl[trialkoxysilane, e.g. [methoxy(polyethyleneoxy)propyl]trimethoxysilane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass article having a low critical inclination angle and an antifouling property, particularly for use in buildings and vehicles, which makes it difficult for dirt to adhere thereto. The present invention relates to a low-critical tilt angle antifouling glass article suitable for a glass plate for a window, a mirror, and the like, which is easy and has a small decrease in transparency due to water droplets attached to the surface, and a method for manufacturing the same.

[0002]

2. Description of the Related Art When water repellency is imparted to a window glass for architectural use, a vehicle, an aircraft, a ship or the like, or a glass plate used for a mirror or a showcase, water droplets containing contaminants are generated. It is known that it is difficult to remain on the surface and has an effect of preventing contamination (antifouling) and burning, and that distortion of a transmitted image or a reflected image due to the spread of water droplets adhering to the surface is known to be reduced. As a method for imparting water repellency to glass, a method of performing a surface treatment with an organic silicon compound having an alkyl group in a molecule (for example, Japanese Patent Publication No.
No. 8173, JP-B-31-11117, JP-B-35-9
760) or a method of applying or fixing an organosilicon compound having a fluoroalkyl group or a perfluoroalkyl group in a molecule on the surface of a glass plate (for example, Japanese Patent Application Laid-Open No.
248480 and JP-A-8-188448).
Among them, it is said that an article obtained by applying or fixing a compound having a fluoroalkyl group or a perfluoroalkyl group on the surface of a glass plate has high water repellency and high antifouling property.

On the other hand, an antifouling glass plate utilizing the photocatalytic activity of titanium oxide or the like has also been proposed (for example, see Japanese Unexamined Patent Publication No.
No. 3-100042). The dirt on the glass surface is oxidatively decomposed and removed by photocatalysis of titanium oxide or the like under light irradiation.

[0004]

However, glass provided with water repellency by the above-mentioned method has a problem that light scattering due to water droplets is large, and good transmission images and reflection images cannot be obtained. In addition, rain streak stains (black streak stains) remaining after rolling of large water droplets containing stains are remarkably observed, which also hinders favorable transmission images and reflection images. This is particularly noticeable in a city or a major arterial road where there is a lot of lipophilic dirt due to automobile exhaust gas or smoke, or in a bathroom. In addition, in a glass having a water repellency provided by a compound having a fluoroalkyl group or a perfluoroalkyl group, since these functional groups have a large dipole moment and a high polarity, dirt is easily adsorbed by an electrostatic effect (H Tada, K. Simoda, K.
Goto, J .; Electrochem. Soc. , 1
42, L230-L232 (1995). ), And there is also a problem that they are easily soiled.

Further, in the antifouling glass plate using the above-mentioned material having photocatalytic activity, if the light, especially ultraviolet rays, is not sufficiently irradiated, the decomposition of dirt is not sufficient. You need to
There is also a problem that the reflectance of the glass plate is likely to be high or interference colors are likely to be exhibited, and the use place is limited.

In view of the above prior art, the present invention does not impair the transmitted image or the reflected image due to water droplets or dirt on the surface, and even if dirt adheres, it is easily removed by natural phenomena such as rainfall. The present invention provides a low critical tilt angle antifouling glass article and a method for producing the same.

[0007]

The low critical tilt angle antifouling glass plate of the present invention is characterized in that an organometallic compound having a polyalkylene oxide group in a molecule or a hydrolyzate thereof is chemically or physically converted to a glass plate substrate. It is fixed or attached to the surface of the material.

The polyalkylene oxide group includes:
A polyethylene oxide group, a polypropylene oxide group and the like are mainly used. The polyalkylene oxide group is non-reactive or low-reactive, but has a weak polarity in the molecule due to its structure in which ether oxygen having hydrophilicity and alkylene group having hydrophobicity are alternately arranged. By treating with an organometallic compound having such a group, a hydroxyl group generated at the glass surface or at the terminal of the organometallic compound can be uniformly covered with a polyalkylene oxide group,
The surface can have a low critical inclination angle at which water droplets start rolling and a surface on which dirt is not easily adsorbed or adhered.

Therefore, in the low critical tilt angle antifouling glass article of the present invention, it is possible to prevent the transmission image and the reflection image from being damaged by water droplets and dirt. In addition, since the low critical angle of inclination antifouling glass article has a relatively low contact angle of water droplets (70 degrees or less), adjacent water droplets are connected to form large water droplets, which are more likely to roll, and that the water droplets do not roll. Even when it remains on the glass surface, the shape of the water droplet is relatively flat instead of spherical as in the case of a contact angle of 90 degrees or more, and the transmitted image or reflection is caused by irregular reflection of light by the water droplet on the surface. The problem of image corruption is greatly reduced.

[0010] Further, in the low critical tilt angle antifouling glass article, since the contact angle of water droplets is relatively low and the falling property is high, even when dirt adheres, water is applied to the glass surface so as to wrap the dirt. Spreads and water droplets containing dirt and dirt components are quickly removed from the surface, so that dirt is easily removed due to natural phenomena such as rainfall, and rain streaking is unlikely to occur.

Further, in the low critical tilt angle antifouling glass article, since the polyalkylene oxide group is non-reactive or low-reactive, the polyalkylene oxide group does not form a chemical bond with a dirt component, and the dirt is removed from the surface of the glass plate. There is no fixed to. Furthermore, since an organic metal compound having a polyalkylene oxide group in the molecule is present on the surface of the glass plate, direct contact between water and the glass plate is eliminated, and the occurrence of burning caused by elution of alkali components and the like is suppressed. There are cases.

The above-mentioned organometallic compound having a polyalkylene oxide group in a molecule or a hydrolyzate thereof is brought into contact with the surface of a glass plate substrate, and these are chemically or physically fixed or adhered to the surface. The molecular layer of the organometallic compound or its hydrolyzate fixed or adhered to the surface of the glass plate is preferably 0.5 to 20 in average molecular layer. The average number of molecular layers X at this time is calculated using the number of molecules N of the organometallic compound or its hydrolyzate present on the surface of the glass plate having the area S and the coating area a per organometallic compound or its hydrolyzate single molecule. Is obtained by the following equation (1).

X = aN / S (1)

The value of a is determined by estimating the amount of adsorption on a glass plate on which an organometallic compound monomolecular adsorption layer is formed by a vapor phase method or the like by estimating the amount of gas generated by thermal decomposition of the organometallic compound, There is a method of estimating from the compound molecular shape and size.

If the average number of molecular layers of the organometallic compound having a polyalkylene oxide group in the molecule or the hydrolyzate thereof is less than 0.5, the water droplets fall off and the effect of preventing adhesion of dirt is not preferred. In addition, the average number of molecular layers is 2
If it is larger than 0, the water droplet falling property and the antifouling effect do not become larger, so that the organometallic compound is wasted, which is not preferable.

The more preferable average number of molecular layers of the organometallic compound or its hydrolyzate is 1 or more and 11 or less, and within this range, the water droplet falling property and the antifouling effect are particularly high.

The average thickness of the organometallic compound having a polyalkylene oxide group in the molecule or its hydrolyzate on the surface of the glass plate is 0.5 nm or more and 80 nm or less. If the thickness is less than 0.5 nm, the water-dropping property and the antifouling effect are small, which is not preferable. If it is larger than 80 nm, the effect is not increased.

The thickness can be measured, for example, by ellipsometry. Here, the average thickness is a numerical value obtained assuming that the thickness is evenly uniform. For example, the coating of the organometallic compound is less dense than the monolayer (that is, not a dense monolayer, but a sparse one). In such a case, the average thickness is smaller than the thickness occupied by a single molecule (height from the outermost surface of the glass plate).

The organometallic compound having a polyalkylene oxide group in the molecule is preferably a metal alkoxide having an alkoxyl group in the molecule. More preferably, it is an alkoxysilane. These groups are easily hydrolyzed, and the organometallic compound can be chemically bonded to the surface of the glass plate, so that a product having higher weather resistance and stain resistance is obtained.

Examples of the organometallic compound having a polyalkylene oxide group in the molecule include [alkoxy (polyalkyleneoxy) alkyl] trialkoxysilane and N
Organosilicon compounds such as-(triethoxysilylpropyl) -O-polyethylene oxide urethane, [alkoxy (polyalkyleneoxy) alkyl] trichlorosilane, N- (trichlorosilylpropyl) -O-polyethylene oxide urethane; titanium (allyloxy) And the like. Among them, [alkoxy (polyalkyleneoxy) alkyl] trialkoxysilane is preferable, and a specific example thereof is [methoxy (polyethyleneoxy) propyl ] Trimethoxysilane, [methoxy (polyethyleneoxy) propyl] triethoxysilane, [butoxy (polypropyleneoxy) propyl] trimethoxysilane, etc., among which [methoxy (polyethylene) Oxy) propyl] trimethoxysilane is more preferred. [Alkoxy (polyalkyleneoxy) alkyl] trialkoxysilane has a linear molecular structure, which facilitates uniform arrangement of polyethylene oxide groups on a glass plate, and has three alkoxyl groups that can be bonded to a glass plate base material. Therefore, it can be firmly bonded to the surface of the glass plate base material, and a product having high water-dropping property and high antifouling property can be obtained. Further, [methoxy (polyethyleneoxy) propyl] trimethoxysilane is more preferable because it is relatively easy to produce, and is easily hydrolyzed to be ready for bonding to a glass plate substrate. As the polyalkylene oxide group, those having 3 to 12 alkylene oxide units are preferable because of easy production.

As a method of fixing or adhering the above-mentioned organometallic compound having a polyalkylene oxide group in a molecule or a hydrolyzate thereof to the surface of a glass plate, the above-mentioned organometallic compound having a polyalkylene oxide group in a molecule, or Any method may be used as long as the hydrolyzate is brought into contact with the surface of the glass plate. For example, a method of applying a liquid containing the organometallic compound or its hydrolyzate to the surface of a glass plate (coating method), a method of immersing the glass plate in a liquid containing the organometallic compound or its hydrolyzate (liquid phase chemistry) Adsorption method), a method of placing a glass plate in the vapor of the organometallic compound or a hydrolyzate thereof and adsorbing the glass plate (gas phase chemical adsorption method), and the like. Of the above methods, the coating method is particularly preferable because it is the simplest and the lowest in cost and can easily form molecular layers of various thicknesses.

The coating method may be a known one, and is not particularly limited. Examples thereof include a method using an apparatus such as a spin coater, a roll coater, a spray coater, and a curtain coater, a dipping and pulling method (dip coating method), A method such as a flow coating method (flow coating method), a method in which a cloth or paper containing a coating solution is brought into contact with the glass plate surface and rubbed with an appropriate force (rubbing method), screen printing, gravure printing, curved surface Various printing methods such as printing are used.

Depending on the substrate of the glass plate, there may be a case where the organometallic compound coating solution cannot be applied uniformly by repelling or the like, but this can be improved by washing or modifying the surface of the substrate. Methods of cleaning and surface modification include alcohol,
Degreasing cleaning with an organic solvent such as acetone or hexane, cleaning with an alkali or acid, polishing the surface with an abrasive, ultrasonic cleaning, ultraviolet irradiation treatment, ultraviolet ozone treatment (ultraviolet irradiation treatment in an oxygen gas atmosphere), plasma treatment, etc. Is mentioned.

For the purpose of improving the durability of the surface of the alkali-containing glass plate substrate before applying the organometallic compound having a polyalkylene oxide group in the molecule or its hydrolyzate, silicon oxide, zirconium oxide, A single-component or multi-component alkali shielding film selected from the group consisting of aluminum, cerium oxide, and titanium oxide may be provided in advance. This alkali shielding film preferably has a main component of silicon oxide, more preferably a binary metal oxide of silicon oxide and zirconium oxide, or a binary metal oxide of silicon oxide and aluminum oxide. A metal oxide whose main component is silicon oxide has a low refractive index and can be formed without significantly deteriorating the optical characteristics of the glass plate, which is preferable. Further, a two-component metal oxide of silicon oxide and zirconium oxide, or a two-component metal oxide of silicon oxide and aluminum oxide is more preferable since alkali shielding ability is high and durability of the organometallic compound on the surface is improved. .

In the two-component metal oxide of silicon oxide and zirconium oxide or the two-component metal oxide of silicon oxide and aluminum oxide, the content of zirconium oxide or aluminum oxide is 1% by weight to 30% by weight.
The following is preferred. When the content is less than 1% by weight, the effect of improving the alkali shielding ability is not so large. When the content is more than 30% by weight, the effect of improving the alkali shielding ability is not improved anymore, and the tendency of the reflectance to increase due to the increase in the refractive index becomes strong. It is not preferable because it becomes difficult to control the optical characteristics of the low-critical tilt angle antifouling glass.

The thickness of the alkali shielding film is preferably 10 nm or more and 300 nm or less. 10n thickness
If it is thinner than 30 m, the effect of shielding alkali is not sufficient.
If the thickness is larger than 0 nm, interference colors due to the film become remarkable, and it becomes difficult to control the optical characteristics of the low critical tilt angle antifouling glass, which is not preferable.

The above-mentioned alkali shielding film can be formed by a known method. For example, the sol-gel method (for example, Yuji Yamamoto, Kanichi Kamiya, Saio Sakuhana, Journal of the Ceramic Industry Association, 90, 328-333 (1
982)), liquid phase deposition method (for example,
No., Japanese Patent Publication No. 4-13301), vacuum film forming method (evaporation, sputter), baking method, spray coating (for example,
3-124523, JP-A-56-96849), C
VD method (for example, Japanese Patent Application Laid-Open No. 55-90441,
No. 201046, JP-A-5-208849) and the like.

A solution in which silicon chloride is dissolved in an alcohol-based solvent or a solution in which silicon alkoxide and a volatile acid such as concentrated hydrochloric acid or concentrated nitric acid are dissolved in an alcohol-based solvent is applied to the surface of a glass substrate. After drying, an alkali shielding silicon oxide film may be formed. In this method, a strong film is formed without firing, so that a low-critical tilt angle antifouling glass excellent in durability can be obtained simply and at low cost. In order to obtain a multi-component alkali shielding oxide film by the above method, it is desirable to add an element other than silicon as acetylacetonate.

When the organometallic compound having a polyalkylene oxide group in a molecule or a hydrolyzate thereof is applied, the solvent for dissolving the organometallic compound is not particularly limited, but it is preferred from the viewpoints of safety, cost and workability. And water, alcohols and ketones are preferably used alone or in combination. Alcohols include methanol, ethanol, propanol, butanol and the like, and ketones include acetone, methyl ethyl ketone, diethyl ketone and the like.

The above-mentioned organometallic compound is used after being hydrolyzed as required. Water and an acid catalyst as needed are added to the organometallic compound solution, hydrolysis is carried out at a certain temperature for a certain time, and if necessary, it is diluted and used for coating.

The conditions for the hydrolysis are not particularly limited.
It is preferable to carry out at a temperature of 0 to 60 ° C. for 3 minutes to 50 hours. If the temperature is lower than 20 ° C. or the time is shorter than 3 minutes, the promotion of hydrolysis is not sufficient, and
If the temperature is higher than ° C or the time is longer than 50 hours, the effect of promoting the hydrolysis is no longer improved, and the life of the coating solution is undesirably shortened.

As the above-mentioned acid catalyst, organic acids such as acetic acid, formic acid, citric acid and p-toluenesulfonic acid are used in addition to mineral acids such as hydrochloric acid, sulfuric acid and nitric acid. The amount of the acid added is not particularly limited, but may be 0.1 mol in a molar ratio to the organometallic compound.
0001 to 2 are good. The added acid amount is 0.000
If it is less than 1, the promotion of the hydrolysis of the organometallic compound is not sufficient, and if it is more than 2, the effect of promoting the hydrolysis is no longer improved and the acid becomes excessive, which is not preferable.

The amount of water added for hydrolysis is not particularly limited, but is preferably 0.1 or more in terms of molar ratio with respect to the organometallic compound. If the amount of water added is less than 0.1 in molar ratio,
The promotion of the hydrolysis of the organometallic compound is insufficient and not preferable.

On the other hand, in the case of an organometallic compound such as chlorosilane, which has a high hydrolysis rate, exemplified by [methoxy (polyethyleneoxy) propyl] trichlorosilane, sufficient hydrolysis proceeds only by the moisture adsorbed on the surface of the glass plate. However, in some cases, it can be fixed to the surface by a dehydration condensation reaction. In this case, it is better to prepare a coating solution using a non-aqueous solvent in which the dissolved moisture is sufficiently reduced, and the resulting low critical tilt angle antifouling glass plate having excellent durability and antifouling properties can be obtained. It is preferred. Examples of the non-aqueous solvent include n-hexane, cyclohexane, xylene, and toluene.

The concentration of the organic metal compound solution used for coating is not particularly limited, but is preferably 0.001 to 5% by weight. It is convenient to apply so that the concentration in this range becomes the above-mentioned thickness by the above-mentioned application method.

The glass plate base material after the application is at 20 to 250 ° C.
At a temperature of 3 minutes to 3 hours. More preferably, heat treatment is performed at a temperature of 80 to 200 ° C. for 3 minutes to 1 hour. By this treatment, the bonding of the organosilane to the surface of the glass plate is strengthened, and the durability of the anti-fouling glass plate with low critical tilt angle is improved. Temperature 20
If the temperature is lower than 0 ° C or the time is shorter than 3 minutes, the above effect is not sufficient and is not preferable. If the temperature is higher than 250 ° C., the organometallic compound may decompose, which is not preferable. Further, if the time is longer than 3 hours, the above effect is not improved any more, which is not preferable from the viewpoint of productivity.

[0037]

Embodiments of the present invention will be described below. [Example 1] Preparation of organometallic compound coating solution In 1,000 ml of commercially available ethanol (purity 99.5%),
1 ml of 0.1N acetic acid was added and stirred. [Methoxy (polyethyleneoxy) propyl] trimethoxysilane (“SIM6492.7” manufactured by Chisso Corporation, content: 90%, molecular weight: 46
0 to 590, 8 g of ethylene oxide units (6 to 9) were added, and the mixture was stirred at 30 ° C. for 1 hour to prepare a coating solution.

Coating of organometallic compound A soda lime silicate glass plate (65 mm × 150 mm × 3 mm), which was polished and washed with a cerium oxide-based abrasive, further ultrasonically cleaned in pure water, and dried, was coated with the coating solution. The liquid was applied on a glass plate by immersion in the glass plate and lifting at a speed of 5 cm / min. This glass plate
After heating and drying at 20 ° C. for 30 minutes and cooling to room temperature, it is lightly washed with pure water and then treated with [methoxy (polyethyleneoxy)
A glass plate having an organometallic compound layer containing a [propyl] group in the molecule was obtained.

Measurement of Number of Organometallic Compound Molecular Layers on Glass Plate The above-mentioned organometallic compound-treated glass plate sample (300 mm × 300 mm × 0.5 mm) separately prepared under the same conditions.
The number of molecular layers in the thickness direction of the organometallic compound layer on the glass plate substrate was determined from the result of quantifying the decomposition gas generated by intensifying heat at 600 ° C. using gas chromatography. 8 (about 30 nm in thickness).

Contact Angle Measurement The contact angle of the obtained glass plate treated with an organometallic compound with respect to 0.4 mg of water droplet was measured using a contact angle meter (“CA-DT” manufactured by Kyowa Interface Science Co., Ltd.). Was 38 degrees.

Critical tilt angle measurement The critical tilt angle, which is a measure of the ease with which water droplets roll, is determined by placing the obtained organometallic compound-treated glass plate sample horizontally, placing a 5 mm-diameter water droplet on top of it, and placing the glass plate on the glass plate. It was 4 degrees as determined by measuring the angle of inclination from the horizontal when the water droplets began to roll while gradually tilting.

Tobacco smoke test A sample of a glass plate treated with an organometallic compound (65 mm ×
150 mm × 3 mm) is placed on the bottom of a cubic box of 24 cm square, and smoke for one commercial cigarette is introduced into the box.
After holding for minutes, the sample was removed. The contact angle of this sample with a 0.4 mg water drop after exposure to cigarette smoke was measured using the contact angle meter, and as shown in Table 2, the contact angle remained 38 degrees, indicating a change. Did not. When the critical tilt angle was measured by the above method, it was 4 degrees, and almost no change was recognized. From this, it was confirmed that the above-mentioned glass plate treated with an organometallic compound had a low critical tilt angle, was less likely to adsorb dirt components, and was less susceptible to dirt.

Outdoor exposure test A test glass plate was installed vertically outdoors in Itami City, Hyogo Prefecture,
An exposure test was conducted for 6 months in an environment simulating a vertical surface under the eaves where rainwater flows down the surface of the test glass plate, and the evaluation of the contamination state of the glass plate after the test was carried out by visual evaluation according to the criteria in Table 1 below and before and after exposure. Was evaluated by the lightness difference ΔL. The lightness difference ΔL was determined by placing a glass plate before and after the exposure test on a white plate, and using a colorimeter (“CR30 manufactured by Minolta Co., Ltd.”).
0)) and measured the lightness L (“Lightness after exposure test”) −
The value of “brightness before exposure test”) was obtained as a brightness difference ΔL. The closer the value of ΔL is to zero, that is, the smaller the absolute value of ΔL, the smaller the degree of contamination.

[0044]

Table 1 ========================= Evaluation Contamination Status −−−−−−− ◎ Almost no concern for dirt ○ Slightly dirt, thin streak is visible △ Dirt, streak is noticeable × Dirt is remarkable, streak is noticeable === ======================

Exposure of the above organometallic compound treated glass plate sample (65 mm × 150 mm × 3 mm)
Table 2 shows the results of the evaluation of the state of contamination after one month (visual evaluation and lightness difference ΔL before and after exposure). From this result, it was confirmed that the glass plate treated with the organometallic compound was hardly stained, and easily stained by rainfall or the like.

Example 2 Preparation of Glass Plate with Silica-Zirconium Thin Film 5 g of zirconium butoxide was added to 1 g of ethyl acetoacetate and stirred at 30 ° C. for 2 hours (Solution A). Separately, 50 g of tetraethoxysilane and 1000 of 2-propanol were used.
g, 1N nitric acid (2.5 g) and water (50 g).
The mixture was stirred at 0 ° C for 2 hours (solution B). Mix solution A and solution B and mix
The mixture was stirred and cured at 0 ° C. for 3 hours and further at 30 ° C. for 1 day to obtain a sol solution for an alkali shielding film.

A soda lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive and further subjected to ultrasonic washing in pure water and dried.
Was immersed in the above-mentioned sol solution for an alkali shielding film, and the sol was applied by pulling up the glass plate at a speed of 10 cm / min.
Then, it is dried at room temperature for several minutes,
For 3 hours to obtain a glass plate on which a silica-zirconia thin film (92% by weight of silica, 8% by weight of zirconia) having a thickness of about 30 nm was formed.

Application of Organometallic Compound The above glass plate with a silica-zirconia thin film (65 mm × 150 mm × 3 m) was dried by ultrasonic cleaning in pure water.
m) Silica having thereon an organometallic compound layer having a polyethylene oxide group in the molecule thereof (the number of molecular layers in the thickness direction is about 8 and the thickness is about 30 nm) under the same method and under the same conditions as those described in Example 1. -A glass plate with a zirconia thin film was obtained.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From these results, it was confirmed that this organometallic compound-treated glass had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 3 Preparation of Glass Plate with Silica Thin Film 5 g of silicon tetrachloride was added to 1000 g of ethanol and stirred at room temperature for 1 hour to obtain a solution for an alkali shielding film. The surface of the soda lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive, and further subjected to ultrasonic washing in pure water and dried, is subjected to conditions of 20 ° C. and 30% RH. Then, the above-mentioned solution for an alkali shielding film was applied by a flow coat method, and dried at room temperature for several minutes to obtain a glass plate on which a silica thin film having a thickness of about 30 nm was formed.

Preparation of Coating Solution for Organometallic Compound To 100 g of commercially available ethanol (purity: 99.5%) was added 0.1 g of an organic metal compound.
2.5 g of 1N hydrochloric acid and [methoxy (polyethyleneoxy)
Propyl] trimethoxysilane ("S" manufactured by Chisso Corporation)
IM6492.7 ", content 90%, molecular weight 460-5
90, ethylene oxide unit number 6 to 9) 1 g is added,
The mixture was stirred at room temperature for 1 hour to prepare a coating solution.

Coating of organometallic compound The above glass plate with a silica film was applied for 1 minute with a cloth impregnated with the above coating solution at 20 ° C. and 30% RH, and the excess was wiped off with a dry cloth. By lightly washing with pure water, an organometallic compound layer containing polyethylene oxide groups in the molecule (the number of molecular layers in the thickness direction is about 8, the thickness is about 3)
0 nm) was formed, and a glass plate with a silica thin film was obtained.

Various tests: Measurement of initial water droplet contact angle and critical inclination angle by the method described in Example 1, measurement of water droplet contact angle and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 4 Preparation of Glass Plate with Silica-Alumina Thin Film To 65 g of ethanol, 10 g of acetylacetone and 25 g of aluminum sec-butoxide were added, and allowed to stand at room temperature for about 1 day to obtain a uniform alcohol solution of aluminum acetylacetonate. (Solution C). 4 g of solution C in ethanol 5
After dissolution in 0 g, 2 g of silicon tetrachloride was added and stirred at room temperature for 1 hour to obtain a sol solution for an alkali-shielding silica-alumina film.

A soda-lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive, and further subjected to ultrasonic washing in pure water and dried.
Then, by applying and drying the sol solution for the alkali-shielding silica-alumina film under the same method and conditions as in Example 3,
Silica-alumina thin film of about 30 nm thickness (silica 90 m
ol%, alumina 10 mol%).

Application of Organometallic Compound On the glass plate (65 mm × 150 mm × 3 mm) provided with the silica-alumina thin film, which had been subjected to ultrasonic cleaning in pure water and dried, under the same method and the same conditions as described in Example 3, A glass plate with a silica-alumina thin film was obtained in which an organometallic compound layer containing a polyethylene oxide group in the molecule (the number of molecular layers in the thickness direction was about 8 and the thickness was about 30 nm) was formed.

Various tests The measurement of the initial contact angle of water droplet and the critical inclination angle, the measurement of the contact angle of water droplet after the cigarette smoke test, the measurement of the critical inclination angle, and the evaluation of the contamination state after the outdoor exposure test were performed by the method described in Example 1. Was. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 5 Preparation of organometallic compound coating solution In 1,000 ml of commercially available ethanol (purity 99.5%),
1 ml of 0.1N acetic acid was added and stirred. Titanium (allyloxypolyethylene oxide) triisopropoxide ("AKT841" manufactured by Chisso Corporation, content: 95%, molecular weight: 620 to 200 g) was added to 800 g of the ethanol-based liquid.
710, 1 g of ethylene oxide units 10) was added and 3
The mixture was stirred at 0 ° C. for 1 hour to prepare a coating solution.

Fixation of Organometallic Compound A glass plate surface was prepared in the same manner as in Example 1 except that the above-mentioned coating solution was used instead of the coating solution containing [methoxy (polyethyleneoxy) propyl] trimethoxysilane in Example 1. The above-mentioned organometallic compound was fixed to obtain a glass plate on which an organometallic compound layer containing a polyethylene oxide group in the molecule (average thickness 2 molecular layers, thickness about 8 nm) was formed.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 6 Preparation of Glass Plate with Silica Thin Film Silica gel powder was saturated until it reached saturation, ie, about 20 g.
Per liter dissolved, hydrofluoric acid concentration 4mo
Water was added to a 1 / liter aqueous hydrofluoric acid solution to dilute the concentration to 2.5 mol / liter,
For 1 hour and aged to prepare a hydrosilicofluoric acid aqueous solution in which silica was supersaturated. In this aqueous hydrofluoric acid solution,
The surface is polished and washed with a cerium oxide-based abrasive, and then ultrasonically washed in pure water, and a dried soda lime silicate glass plate (65 mm × 150 mm × 3 mm) is immersed in the plate.
The mixture was allowed to stand at 60 ° C for 6 hours. Thereafter, the glass plate was taken out, washed with water and dried to obtain a glass plate having a silica thin film having a thickness of about 100 nm formed on the surface of the glass plate. As a result of analyzing this film portion using ESCA, it was confirmed that the film portion was made of dense silicon dioxide.

Application of Organometallic Compound On the above-mentioned glass plate with silica thin film (65 mm × 150 mm × 3 mm), which was subjected to ultrasonic cleaning in pure water and dried, polyethylene oxide was applied under the same method and conditions as described in Example 1. Organometallic compound layer containing a group in the molecule (average thickness 2
A glass plate with a silica thin film on which a molecular layer (about 8 nm in thickness) was formed was obtained.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

[Example 7] Preparation of organometallic compound coating liquid 1000 ml of commercially available ethanol (purity 99.5%) and 1
0.1 ml to a mixture of 2,000 ml of commercially available 2-propanol
10 ml of N nitric acid was added and stirred. 1500 g of this liquid was added to N- (triethoxysilylpropyl) -O-polyethylene oxide urethane (“SIT819 manufactured by Chisso Corporation”).
2.0 ", a molecular weight of 400 to 500, and an ethylene oxide unit number of 4 to 6) (0.05 g) was added thereto, followed by stirring at 20 ° C for 5 hours to obtain an organometallic compound coating solution.

Coating of organometallic compound The surface is polished and washed with a cerium oxide-based abrasive, and then ultrasonically washed in pure water and dried on a soda lime silicate glass plate (60 mm × 150 mm × 3 mm) at 20 ° C.
Under the condition of 0% RH, the above-mentioned organometallic compound coating solution was applied by a flow coating method, and the glass plate was heated at 150 ° C.
And cooled to room temperature, and then washed with pure water to form a glass plate on which an organometallic compound layer containing polyethylene oxide groups in the molecule (an average thickness of 0.8 molecular layer and a thickness of about 20 nm) is formed. I got

Various tests: Measurement of initial contact angle of water drop and critical tilt angle by the method described in Example 1, measurement of contact angle of water drop and critical tilt angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 8 Preparation of Glass Plate with Silica Thin Film 50 g of tetramethoxysilane, 300 of 2-propanol
g, 1N nitric acid 2.5g and water 30g,
And stir at 30 ° C. for 1 day.
A sol solution for an alkali shielding film was obtained.

A soda lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive, further subjected to ultrasonic washing in pure water and dried.
Was immersed in the above sol solution for an alkali shielding film, and the sol was applied by pulling up the glass plate at a speed of 30 cm / min.
Then, it is dried at room temperature for several minutes,
For 3 hours to obtain a glass plate on which a silica thin film having a thickness of about 250 nm was formed.

Application of Organometallic Compound On a glass plate (65 mm × 150 mm × 3 mm) provided with a silica thin film, which was subjected to ultrasonic cleaning in pure water and dried, polyethylene oxide was applied under the same method and under the same conditions as described in Example 7. A glass plate with a silica thin film on which an organometallic compound layer containing a group in the molecule (average thickness 0.8 molecular layer, thickness about 20 nm) was obtained.

Various tests: Measurement of initial contact angle of water drop and critical inclination angle by the method described in Example 1, measurement of contact angle of water drop and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 9 Preparation of Organometallic Compound Poly (propylene glycol) monobutyl ether (Ald) completely dehydrated using molecular sieve 3A
Rich Co., Ltd., molecular weight 400-500, propylene oxide unit number 5-6) 4 parts by weight were mixed with 400 parts by weight of n-hexane completely dehydrated using molecular sieve 3A, and 0.23 part by weight Metal Na was added and mixed at 40 ° C. for 5 hours. While mixing this solution,
After 2.4 parts by weight of 3-chloropropyltriethoxysilane (manufactured by Chisso Corporation, SIC2407.0) was added dropwise, the mixture was refluxed for 3 hours. The obtained liquid was cooled to room temperature, and after removing sodium chloride using an ion exchange resin, the solvent was removed by fractional distillation to obtain [butoxy (polypropyleneoxy) propyl] triethoxysilane.

Preparation of Organic Metal Compound Coating Solution In 1,000 ml of commercially available ethanol (purity 99.5%),
1 ml of 0.1N acetic acid was added and stirred. 8 g of the above-mentioned [butoxy (polypropyleneoxy) propyl] triethoxysilane (molecular weight: 570 to 630, 5 to 6 propylene oxide units) was added to 792 g of the liquid mainly composed of ethanol, and the mixture was stirred at 30 ° C. for 1 hour and coated. A liquid was prepared.

Organometallic Compound Fixation The surface of a glass plate was prepared in the same manner as in Example 1 except that the above coating solution was used instead of the coating solution containing [methoxy (polyethyleneoxy) propyl] trimethoxysilane in Example 1. To obtain a glass plate on which an organometallic compound layer containing a polyethylene oxide group in the molecule was formed.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Example 10 Preparation of Glass Plate with Silica Thin Film 30 parts by weight of tetraethoxysilane, 2-propanol 2
00 parts by weight, 200 parts by weight of ethanol, 2.5 parts by weight of 1N nitric acid and 30 parts by weight of water.
The mixture was stirred for 30 hours and further cured at 30 ° C. for 1 day to obtain a sol solution for an alkali shielding film.

A soda-lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive and further subjected to ultrasonic washing in pure water and dried.
Was immersed in the above-mentioned sol solution for an alkali shielding film, and the sol was applied by pulling up the glass plate at a speed of 10 cm / min.
Then, it is dried at room temperature for several minutes,
For 3 hours to obtain a glass plate on which a silica thin film having a thickness of about 80 nm was formed.

Coating of Organometallic Compound On the glass plate with silica thin film (65 mm × 150 mm × 3 mm), which had been subjected to ultrasonic cleaning in pure water and dried, polyethylene oxide was applied under the same method and conditions as described in Example 9. A glass plate with a silica thin film on which an organometallic compound layer containing a group in the molecule was formed was obtained.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. From this result, it was confirmed that the glass treated with the organometallic compound had a low critical tilt angle, was hardly stained, and was easily stained by rainfall or the like.

Comparative Example 1 A soda lime silicate glass plate (65 mm × 150 mm) which was polished and washed with a cerium oxide-based abrasive, further ultrasonically washed in pure water and dried.
× 3 mm), the critical contact angle of the initial water droplet contact angle, the measurement of the contact angle of the water droplet after the cigarette smoke test, the measurement of the critical inclination angle, and the evaluation of the contamination state after the outdoor exposure test were performed by the method described in Example 1. Table 2 shows the results. The glass immediately after washing had a low contact angle with water droplets, but had a high critical tilt angle, and when exposed to tobacco smoke, adsorbed dirt components and increased the contact angle. That is, it can be said that it is easily stained. Further, in the outdoor exposure test, deposited inorganic stains were conspicuous, and some burns and rain streak stains were also observed. In other words, it can be said that an untreated glass plate tends to generate inorganic stains and burns.

Comparative Example 2 Preparation of Fluorine Water Repellent Solution (Heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane (SIH58 manufactured by Chisso Corporation)
41.0) 1 part by weight was dissolved in 1000 parts by weight of cyclohexane to obtain a liquid repellent solution.

Formation of a water-repellent layer on a glass plate A soda lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been polished and washed with a cerium oxide-based abrasive, further ultrasonically washed in pure water and dried. After being immersed in the water repellent solution and kept at 30 ° C. for one day, the glass plate was taken out and washed with cyclohexane to obtain a glass plate having a water repellent monolayer formed on the surface.

Various tests The initial water drop contact angle and the critical tilt angle were measured by the method described in Example 1, the water drop contact angle and the critical tilt angle were measured after the cigarette smoke test, and the contamination state after the outdoor exposure test was evaluated. . Table 2 shows the results. The initial contact angle of this glass was high and did not change after the cigarette smoke test, but the critical tilt angle showed a high value both at the initial stage and after the cigarette smoke test. In addition, the observation of the contamination state after the outdoor exposure test revealed that the whole was stained black and that the rain streak stain was considerably conspicuous. This stain was easily removed by wiping with a cloth or the like, and was not a deposited stain. However, the absolute value of ΔL was large due to the overall stain. In other words, it can be said that this glass plate easily absorbs dirt and easily generates rain streak dirt.

Comparative Example 3 Preparation of Organosilane Coating Solution To 1000 ml of commercially available 2-propanol, 1 ml of 0.1N acetic acid was added and stirred. 792 g of this liquid was added to n-propyltrimethoxysilane (“LS” manufactured by Shin-Etsu Chemical Co., Ltd.).
-3120 ”), and stirred at 30 ° C. for 1 hour.
An organosilane coating solution was prepared.

A soda-lime silicate glass plate (65 mm × 150 mm × 3 mm) which has been subjected to surface polishing and washing with a cerium oxide-based abrasive and further subjected to ultrasonic washing in pure water and dried.
Using the above organosilane coating solution, a glass plate with a silica thin film having an organosilane layer containing an n-propyl group in the molecule was obtained in the same manner as in Example 1.

Measurement of Number of Organosilane Molecular Layers on Glass Plate The number of molecular layers of the organosilane on the substrate was calculated from the concentration of the organosilane coating solution, the thickness of the coating solution, and the like. However, the occupied area of one molecule of n-propyltrimethoxysilane was determined to be 2 × 10
^-15 cm ² was assumed.

Various tests: Measurement of initial contact angle of water droplet and critical inclination angle by the method described in Example 1, measurement of contact angle of water droplet and critical inclination angle after cigarette smoke test,
The pollution state after the outdoor exposure test was evaluated. Table 2 shows the results. The initial contact angle of this glass was large and did not change after the cigarette smoke test, but the critical tilt angle showed a high value both at the initial stage and after the cigarette smoke test. In addition, the observation of the contamination state after the outdoor exposure test revealed that the whole was stained black and that the rain streak stain was considerably conspicuous. This stain was easily removed by wiping with a cloth or the like, and was not a deposited stain. However, the absolute value of ΔL was large due to the overall stain. In other words, it can be said that this glass plate easily absorbs dirt and easily generates rain streak dirt.

[0087]

Table 2 ================================== Initial Tobacco Smoke Test After Outdoor Exposure Test Contact Angle Critical Inclination angle Contact angle Critical inclination angle Pollution state (degree) (degree) (degree) (degree) Visual evaluation ΔL --- --- --- --- --- --- --- --- --- --- Example 1 384 384 -5 238 384 -4 -3 338 384 -4 -4 438 384 4 -3 455 546 6 -9 6 445 555 ○ -6 746 6488 ○ -11 847 647 7 ○ -6 950 5 528 ○ １０ 10 10 50 65 517 − -8 − − − − − ８ −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 8 76 20 △ -20 ==================================

Also, the low critical tilt angle antifouling glass plates described in Examples 1 to 10, for example, the glass of Example 1 and the glass coated with the conventional fluorine-based water repellent illustrated in Comparative Example 2 were placed horizontally. When arranged side by side, water droplets were uniformly attached by spraying, and strong light was irradiated from directly above, the glass of Comparative Example 2 coated with a fluorine-based water repellent had a large contact angle of 107 degrees, so that the water droplet While the surface becomes pure white due to irregular reflection on the glass surface and the transmitted image becomes almost invisible due to irregular reflection on the glass surface, the water droplets are relatively flat in the low critical tilt angle antifouling glass article of the present invention. And there was almost no irregular reflection, and the transmitted image was not impaired. In addition, it was confirmed that when the glass plate was slightly tilted, in the low critical tilt angle antifouling glass article of the present invention, water droplets rolled down, so that a transmitted image was more easily seen.

[0089]

According to the present invention, dirt hardly adheres,
Further, even when dirt adheres, the critical inclination angle is low, so that the dirt is easily removed by natural phenomena such as rainfall, and it is difficult for rain streak to be generated. Low-critical-angle antifouling glass articles that ensure safety and greatly reduce the time and effort required to always obtain a good transmitted or reflected image when used under conditions where water or water easily condenses on the surface Is obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Sunada 3-5-1, Doshumachi, Chuo-ku, Osaka-shi Japan Sheet Glass Co., Ltd.

Claims (25)

[Claims] 1. A low critical tilt angle antifouling glass article in which an organometallic compound containing a polyalkylene oxide group in a molecule or a hydrolyzate thereof is chemically or physically fixed or adhered to the surface of a glass substrate. 2. The method according to claim 1, wherein the fixed or adhered organometallic compound or a hydrolyzate thereof has an average molecular layer number of 0.5 to 20 or 0.5 nm to 80 n on the surface of the glass substrate.
The low critical tilt angle antifouling glass article according to claim 1, which has an average film thickness of not more than m. 3. The low critical tilt angle antifouling glass article according to claim 1, wherein the organometallic compound is a metal alkoxide compound or a metal halide compound. 4. The low critical tilt angle antifouling glass article according to claim 1, wherein the organometallic compound is an alkoxysilane or a chlorosilane. 5. The low critical tilt angle antifouling glass article according to claim 1, wherein the organometallic compound is [alkoxy (polyalkyleneoxy) alkyl] trialkoxysilane. 6. The low critical tilt angle antifouling glass article according to claim 5, wherein the organometallic compound is [methoxy (polyethyleneoxy) propyl] trimethoxysilane. 7. The alkali-containing glass plate wherein the glass substrate has an alkali shielding film formed on the surface.
The low-critical tilt angle antifouling glass article according to any one of the above. 8. The thickness of the alkali shielding film is 10 nm.
The low critical tilt angle antifouling glass article according to claim 7, having a thickness of not less than 300 nm. 9. The low critical gradient according to claim 7, wherein the alkali shielding film is made of at least one metal oxide selected from the group consisting of silicon oxide, zirconium oxide, aluminum oxide, cerium oxide, and titanium oxide. Corner antifouling glass articles. 10. The method according to claim 1, wherein the alkali shielding film is made of silicon oxide 70.
The low critical tilt angle antifouling glass article according to claim 9, comprising at least one metal oxide by weight. 11. The alkali shielding film is made of a binary metal oxide of silicon oxide and zirconium oxide.
A low critical tilt angle antifouling glass article according to the above. 12. The low critical tilt angle antifouling glass article according to claim 11, wherein the zirconium oxide content of the binary metal oxide of silicon oxide and zirconium oxide is from 1% by weight to 30% by weight. 13. The method according to claim 9, wherein the alkali shielding film comprises a binary metal oxide of silicon oxide and aluminum oxide.
A low critical tilt angle antifouling glass article according to the above. 14. The low critical tilt angle antifouling glass article according to claim 13, wherein the binary metal oxide of silicon oxide and aluminum oxide has an aluminum oxide content of 1% by weight or more and 30% by weight or less. 15. A solution containing an organometallic compound containing a polyalkylene oxide group in a molecule or a hydrolyzate thereof is brought into contact with the surface of a glass substrate, and the solution is chemically or physically fixed to the surface of the glass substrate. A method for producing a low critical tilt angle antifouling glass article to be adhered. 16. A solution containing an organometallic compound containing a polyalkylene oxide group in a molecule or a hydrolyzate thereof is applied to the surface of a glass substrate, dried, and chemically or physically immobilized on the surface of the glass substrate. Alternatively, a method for producing a low critical tilt angle antifouling glass article attached. 17. The method according to claim 15, wherein the organometallic compound is a metal alkoxide compound. 18. The method according to claim 15, wherein the organometallic compound is an alkoxysilane. 19. The method according to claim 15, wherein the organometallic compound is [alkoxy (polyalkyleneoxy) alkyl] trialkoxysilane. 20. The method according to claim 19, wherein the organometallic compound is [methoxy (polyethyleneoxy) propyl] trimethoxysilane. 21. The glass substrate contains an alkali, and comprises a metal chloride, alkoxide and acetylacenate before the organometallic compound or its hydrolyzate is brought into contact with the surface of the glass substrate. At least one metal compound selected from the group, alcohol-based,
A solution dissolved in a ketone or ether solvent and subjected to a dehydrochlorination reaction or a hydrolysis reaction is applied to the surface of a glass substrate and dried to form an alkali shielding oxide film.
21. The method for producing a low critical tilt angle antifouling glass article according to any one of 5 to 20. 22. The method according to claim 21, wherein the metal compound is silicon, zirconium, aluminum, cerium or titanium chloride, alkoxide or acetylacetonate. 23. The method according to claim 22, wherein the metal compound is silicon chloride or alkoxide, or zirconium, aluminum, cerium or titanium acetylacetonate. 24. The low criticality according to claim 22, wherein said solution contains at least 70 mol% of at least one silicon compound selected from the group consisting of silicon chloride and silicon alkoxide with respect to the total amount of said metal compounds. A method for producing a tilt angle antifouling glass article. 25. The method for producing a low critical tilt angle antifouling glass article according to any one of claims 21 to 24, wherein the solvent is an alcohol solvent.