JPH08208275A - Water-repellent glass article and its production - Google Patents

Abstract

PURPOSE: To obtain a glass article excellent in durable performances such as weather resistance, water resistance, moisture resistance or abrasion resistance. CONSTITUTION: This water-repellent silicate glass article contains fluorine introduced from the outside, bonded to silicon of silicate glass article body in the surface layer and forms a water-repellent layer composed of an organic silazane compound on the surface of silicate glass article body not containing tin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is useful for architectural glass plates, particularly architectural glass plates, windshields for automobiles, vehicles, aircraft or ships, optical parts lenses and other glass products requiring water repellency. , A glass article having excellent water repellency such as weather resistance, moisture resistance, water resistance, and abrasion resistance, and a method for producing the same.

[0002]

2. Description of the Related Art When a surface of a glass article is treated to impart water repellency, 1) water droplets containing a polluting component do not remain on the glass surface, so that the glass has an effect of preventing contamination and burning of the glass. When water-based glass is used for windshields and side windows of automobiles, various effects are expected, such as rainwater adhering to the glass surface is blown off by wind pressure even when driving in the rain, ensuring the driver's view and improving driving safety. it can. In addition, as a method for producing such a water-repellent glass article, a water-repellent agent composed of an organosilicon compound centered on polydimethylsiloxane or a fluorine-containing silicon compound is wet-coated on the glass surface, and plasma or vapor deposition is used. A method of dry coating is generally used. However, in the method of directly applying the water repellent agent to the glass, it is difficult to maintain the water repellent performance for a long period of time because the adhesive force between the water repellent agent and the glass is weak.

In order to solve such a problem, there has been proposed a method in which the surface of a glass article is pretreated with a metal oxide layer, and then the surface of the metal oxide is silylated with a silyl compound (Japanese Patent Laid-Open No. Hei 10 (1999) -242242). 2-311332).

[0004]

However, in Japanese Patent Laid-Open No. 2-311332, although the durable adhesive strength such as water resistance and moisture resistance is considerably improved, the durability is not sufficient for outdoor use, and the metal oxide is not used. Since a heat treatment at about 400 ° C. or higher is required to form the material layer, it cannot be applied to the tempered glass having a compression strain layer, and there is a problem that the cost is high.

The inventors of the present invention have eliminated such drawbacks and provided glass articles such as plate glass and tempered glass having excellent durability such as weather resistance, water resistance, moisture resistance and abrasion resistance and having water repellency. The purpose is to provide.

[0006]

Means for Solving the Problems As a result of earnest research, the present inventor has improved the adhesion between a substrate and a water repellent by treating the glass surface with a specific hydrofluoric acid to improve the above durability performance. I found that it could be improved.

That is, according to the present invention, an organosilazane compound is formed on the surface of a silicate glass article matrix containing fluorine, which is introduced from the outside and is bonded to silicon of the silicate glass article matrix, in the surface layer and does not contain tin. It is a water-repellent silicate glass article having a water-repellent layer made of.

The present invention will be described in detail below. As the silicate glass of the composition of the glass article used in the present invention,
Usual alkali silicate glass, for example, soda-lime silicate glass, and soda-lime silicate glass having a compression strained layer on the surface by heat or chemical strengthening are used. The shape of the glass article is not only flat,
It may have any shape such as a curved plate shape or a box shape. Such a glass article has various impurities and stains on the surface layer due to the manufacturing process. For example, tin is inevitably present as impurities on the glass surface produced by the float method, and carbon is inevitably present as stains.

In the present invention, the surface layer of the silicate glass article base material contains fluorine which is introduced from the outside and is bonded to silicon of the silicate glass article base material. The silicate glass article is preferably one obtained by removing the surface layer of the original silicate glass article matrix. As means for incorporating the above-mentioned fluorine into this surface layer, chemical polishing (etching), that is, a method of contacting or immersing the glass substrate in an aqueous solution of hydrofluoric acid is used. When using this method, the concentration of hydrofluoric acid, the immersion temperature, and the immersion time are not particularly limited, but if the etching amount is reduced, impurities and stains on the surface are not removed, and if the etching amount is too large, unevenness occurs on the surface. This causes scattering of light and reduces the transmittance. Therefore, the surface layer to be scraped off is 2 μm to 50 μm.
m, hydrofluoric acid concentration is 0.5% to 50%, and immersion temperature is 10
Desirably, the temperature is 50 ° C to 50 ° C, and the immersion time is 1 minute to 90 minutes. Impurities and stains on the surface of the glass article are removed by such treatment, and silicon in the matrix of the glass article and fluorine in the aqueous solution of hydrofluoric acid are bonded to the surface of the glass article to form a fluorosilane group (Si-F). Is generated.

In the present invention, a water repellent layer made of an organic silazane compound is formed on the surface of a silicate glass article base material containing fluorine on the surface. The organosilazane compound is a nitrogen analog of polysiloxane, and is composed of Si--N--S.
All that have i-joins are included. For example, as a typical example, hexamethyldisilazane, [CF ₃ (CF ₂ )
₇ CH ₂ CH ₂ Si] ₂ NH, 1,3-divinyl-1,1,
3,3-tetramethyldisilazane, 1,3-diphenyltetramethyldisilazane, octamethylcyclotetrasilazane, 1,1,3,3-tetramethyldisilazane, polytitanosilazane, polydisilacyclobutasilazane, polyalkoxy Examples thereof include silylalkylene disilazane, hexamethylcyclotrisilazane, organotetrachlorosilazane, and hydridothiosilazane, but the present invention is not limited to these descriptions. In addition, these silazane compounds may be used as a mixture, or may be used after partially producing a hydrolysis-condensation product with an acid, an alkali or the like. Further, these silazane compounds may be copolymerized with those having an acryl group, an epoxy group or other modifying groups. In addition, these silazanes are partially converted into organochlorosilane and bis (methyldichlorosilyl)
It may be reacted with ethane or the like. Further, in order to lower the surface energy of these silazane compounds, these compounds may be partially substituted with fluorine or the like. Further, a small amount of SiO bond may be contained in these silazane compounds.
Further, a part of these silazane compounds may be treated with ammonia.

In the present invention, if desired, a solvent, a curing agent, a curing catalyst, etc. may be added to the silazane compound.

The solvent must be one that dissolves the above organic silazane compound and can be evenly applied to the substrate. Generally, fluorine-based, aliphatic-based or aromatic-based,
Examples thereof include ketone type and ester type solvents.

It is not always necessary to use a curing agent, but it may be appropriately selected depending on the application. For example, with respect to an organic silazane compound having a hydroxyl group in the molecular chain, the moisture resistance and water resistance of the film can be improved by adding a curing agent such as polyisocyanate.

The curing catalyst, although not necessarily required, is suitably used for promoting the curing of the organic silazane compound having a functional group and increasing the stability of the film. Accelerating catalysts for the hydrolysis and condensation of alkoxy groups include hydrochloric acid, sulfuric acid, nitric acid, glacial acetic acid and other acid catalysts, sodium hydroxide, potassium hydroxide, ammonia and other alkali catalysts, ammonium perchlorate, magnesium perchlorate, and aluminum. Acetylacetonate is mainly used. As a reaction catalyst for isocyanate and hydroxyl group, tin-based catalysts such as dibutyltin dilaurate and amine catalysts are generally used. Further, a platinum catalyst is generally used to bond the mercapto group and the vinyl group. A large number of catalysts such as azo-based or peroxide-based catalysts are commercially available for thermal polymerization of (meth) acryloxy groups, and acetophenone-based and benzophenone-based catalysts for polymerization by ultraviolet rays or electron beams. Anion for polymerization of vinyl group,
Known methods such as cationic catalysts are used.

In the present invention, a layer of a silazane compound is formed on the surface of a silicate glass article containing fluorine on the surface. At this time, the silazane compound reacts with water (H ₂ O) adsorbed in the air or on the surface of the glass article or a silanol group (Si-OH) on the surface of the glass article to form ammonia (NH ₃ ) as a by-product on the glass surface. Join. A condensation reaction by a dehydrofluoric acid reaction occurs between the silanol group formed in the layer of the silazane compound and the fluorosilane (Si-F) present on the glass surface. Accelerate the reaction. As a result,
It is considered that a film having a higher bond density with the glass surface is formed.

As the method for forming the water repellent layer made of the organic silazane compound, a method of applying a solution containing the organic silazane compound to a glass body having a fluorine-containing layer formed on the glass surface, and the organic silazane compound are used. There are various methods such as a dry coating method by vapor deposition or plasma polymerization, or a method of evaporating and adsorbing the above organic silazane compound. However, in consideration of cost, a method of applying a solution containing the above organic silazane compound is preferable.

As a method for applying the solution containing the above organic silazane compound, a dipping method, a spraying method, or a commonly used method is applied.
The roller coating method, the flow coating method, the rubbing method, etc. are used. The substrate coated with the organic silazane compound in this manner is air-dried, or at a temperature of 50 to 200 ° C.
A water-repellent film can be formed on the fluorine-containing layer by heat treatment for 0 minutes. The application method, drying and heat treatment times, etc. may be appropriately selected according to the required product. The coating film thickness is several nm (1 molecular layer) to 500 nm.
Is desirable. If the coating film thickness exceeds 500 nm, the water-repellent layer will have poor abrasion resistance and the appearance after the abrasion test will be poor.

[0018]

According to the present invention, the fluorine-containing glass layer produced by treating the glass surface with an aqueous solution of hydrofluoric acid exhibits good properties as an adhesive layer of an organic silazane compound, such as water resistance and moisture resistance. A water-repellent glass article having excellent durability was obtained.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. <Evaluation and test method> 1) Contact angle: The contact angle of water was measured by the sessile drop method using a contact angle meter CA-D manufactured by Kyowa Interface Science Co., Ltd. Five points were measured for each sample, and the average value was used as the contact angle value. 2) Hot water resistance: The contact angle was measured after the sample was immersed in boiling water for 4 hours. 3) Abrasion resistance: The surface of the sample was reciprocally abraded 3000 times while applying a load of 300 g / cm ^{2 to} the sample, and the contact angle was measured. 4) Turbidity difference: Turbidimeter (MODE, manufactured by Nippon Denshoku Industries Co., Ltd.)
LNDH-20D) was used to measure the turbidity of the wear resistance and hot water resistance before and after the test, and the difference was determined.
The smaller this difference is, the more the transparency of the glass article is not deteriorated by the abrasion resistance and hot water resistance tests.

<Preparation of Fluorine-Containing Layer> Example 1 A float plate glass (soda lime silicate glass) having a thickness of 3 mm and 20 cm × 20 cm was dipped in an aqueous solution of hydrofluoric acid (HF) having a concentration of 2.0% for about 30 minutes. The dirt and tin were removed, and a fluorine-containing layer was formed on the surface, followed by washing with water. At this time, the thickness of the glass etching removal layer is 4
Was about 6 μm. Further, when this glass body was analyzed by ESCA, it was confirmed that F was detected on the outermost surface, and thus this glass body contained Si—F bonds on the surface.

The surface of the glass substrate on which the fluorine-containing layer was formed as described above was treated with a disilazane water repellent, KP801.
([CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si] ₂ NH, manufactured by Shin-Etsu Chemical Co., Ltd.), and immersed at about 350 mm / min. The water repellent layer was applied to the surface of the substrate by pulling it up at a speed of. After naturally drying for 10 minutes, it was baked at 150 ° C. for 30 minutes to prepare a water repellent layer. The thickness of the obtained water repellent layer was about 10 nm.

Comparative Example 1 A water-repellent glass was prepared in the same manner as in Example 1 except that the substrate on which the fluorine-containing layer was formed was changed to a normal float soda lime type plate glass on which the fluorine-containing layer was not formed.

Comparative Example 2 A water-repellent glass was prepared in the same manner as in Example 1 except that a polydimethylsiloxane water-repellent agent Super Rain-X (manufactured by Unelco) was used as the water-repellent agent.

The durability of the water-repellent glass produced as described above was evaluated and shown in the table. In Example 1, Comparative Example 1
It is clear that the durability of the water-repellent glass is improved as compared with 2.

[0025]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Takigawa 3-5-11 Doshomachi, Chuo-ku, Osaka City Japan Sheet Glass Co., Ltd.

Claims (2)

[Claims] 1. A repellent agent comprising an organic silazane compound is formed on the surface of a silicate glass article matrix containing fluorine, which is externally introduced and is bonded to silicon of the silicate glass article matrix, in the surface layer and does not contain tin. A water-repellent silicate glass article, wherein a water layer is formed. 2. A surface of a silicate glass article is brought into contact with an aqueous solution of hydrofluoric acid to form a fluorine-containing glass layer thereon, and a solution containing an organic silazane compound is applied to the surface of the fluorine-containing glass layer. A method for producing a water-repellent silicate glass article, which comprises: