JP2002121480A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition capable of forming a coating film which gives a sufficient strength to the surface of a substrate, especially glass, has sufficient alkali durability, even when the thickness of the coating film is small, and scarcely generates iris. SOLUTION: This coating composition comprising (a) a zirconium compound in which a β-diketone and/or a β-ketoester are coordinated, (b) at least one silane compound selected from the group consisting of alkoxysilanes and alkoxysilane oligomers, and, if necessary, a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a coating composition, a method for strengthening a glass surface using the composition, and a glass product formed by the method.

[0002]

2. Description of the Related Art For the purpose of protecting or strengthening the surface of various substrates, formation of a protective film or a reinforcing film on the surface has been studied. In particular, it is well known that glass products have much lower strength than the theoretical strength, and the above-mentioned protective film or reinforced film has been studied. In general, in the production of glass products, in the process of forming molten glass, the temperature of the glass surface rapidly drops due to the glass surface coming into contact with the outside air, causing distortion due to the temperature difference between the inside and outside of the glass, It is believed that fine flaws form. For this reason, as described above, the material necessarily has much lower strength than the theoretical strength.

[0003] Among glass products, in particular, a glass bottle filled with a carbonated beverage, for example, a beer bottle, may have an internal pressure of 2.5 kg / cm ^{2 due} to carbon dioxide gas. To withstand this pressure, it is necessary to increase the thickness of the glass bottle. However, if the thickness of the glass bottle is increased, the weight of the glass bottle itself will increase, and it will be inconvenient to transport and carry.

Accordingly, a film is formed on the surface of a glass bottle, and the surface of the glass is strengthened by filling in fine scratches on the glass surface, thereby preventing new scratches from being generated by contact between the glass and other objects. The weight of the glass bottle has been reduced. As a coating formed on the glass bottle, a metal oxide, particularly, a tin oxide film or a titanium oxide film is used.

[0005] Returnable bottles such as the above-mentioned beer bottles are repeatedly used several tens of times, and therefore require some characteristics as compared with disposable bottles used only once. For example, a returnable bottle needs to be washed with high-temperature alkaline water every time it is reused, so that a film having sufficient alkali durability is required. If the film of the returnable bottle is peeled off by washing with high-temperature alkaline water, the strength of the returnable bottle is reduced and cannot be used repeatedly.

On the other hand, Japanese Patent No. 2672391 discloses a method for improving the strength of the glass bottle surface by bringing a material capable of forming a tin oxide or titanium oxide film into contact with the glass bottle surface. According to this publication, by maintaining the outer surface temperature of the glass bottle in the range of 550 to 700 ° C. and controlling the film thickness to 400 to 1000 angstroms, sufficient alkali durability and generation of iris can be obtained. It is described that an unseen film is obtained.

However, tin oxide is not always excellent in alkali durability. In addition, titanium oxide has relatively good alkali durability, but when the alkali durability is sufficient, the refractive index of titanium oxide is relatively large, so that an iris is formed on the surface of the glass bottle and the container is used as a container. Has the disadvantage that its commercial value is reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a base material having a sufficient strength, particularly a glass surface, and a thin film. Has sufficient alkali durability,
Another object of the present invention is to provide a coating composition capable of forming a film having less iris. It is another object of the present invention to provide a method for strengthening a glass surface using the composition, and a glass product obtained by the method.

[0009]

Means for Solving the Problems The present inventors have found that when a film is formed on a substrate, particularly a glass substrate, using a coating composition containing a coordinated zirconium compound and a silane compound, the film thickness becomes small. However, they found that a film capable of exhibiting practically sufficient strength and alkali durability was formed on the surface of the substrate, and completed the present invention.

The coating composition of the present invention is a silane that is at least one selected from the group consisting of a zirconium compound (a) to which a β-diketone and / or a β-ketoester is coordinated and an alkoxysilane and an alkoxysilane oligomer. It consists of a compound (b) and contains a solvent as needed.

In a preferred embodiment, in the zirconium compound (a), the molar ratio of the zirconium atom to the β-diketone and / or β-ketoester is from 1: 0.2 to 1: 4.0. .

[0012] In a preferred embodiment, the β-diketone is acetylacetone.

In a preferred embodiment, the β-ketoester is an alkyl acetoacetate (C1 to C4).

In a preferred embodiment, the composition contains the silane compound (b) in a ratio of 0.01 to 5.0 mol per 1 mol of the zirconium compound (a).

According to the method for strengthening a glass surface of the present invention, the above-mentioned coating composition is applied to the surface of a glass substrate, and the zirconium compound (a) and the silane compound (b) in the composition are thermally decomposed. Forming an oxide film on the substrate surface.

In a preferred embodiment, the method comprises the step of applying the coating composition to a heated glass substrate.

In another preferred embodiment, the method comprises the steps of applying the coating composition to a glass substrate surface and firing.

The present invention includes a glass product having an oxide film on the surface, obtained by the above method.

[0019] In a preferred embodiment, the glassware is a glass bottle.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A zirconium compound (a) to which a β-diketone and / or β-ketoester is coordinated, which is contained in a coating composition of the present invention (herein abbreviated as zirconium compound (a)) Is a coordination compound formed from a zirconium-containing compound as a raw material and at least one compound selected from the group consisting of β-diketones and β-ketoesters.

As the zirconium-containing compound as the raw material, zirconium alkoxide or zirconium tetrachloride is used. The zirconium alkoxide is not particularly limited, but is preferably a lower alcohol alkoxide of zirconium. Examples of the zirconium alkoxide include tetraethoxy zirconium, tetra-n-propoxy zirconium, tetraisopropoxy zirconium, tetra-n-butoxy zirconium, tetra-t
-Butoxyzirconium and the like.

The β-diketone is not particularly restricted but includes acetylacetone, benzoylacetone, dipivaloylmethane and the like. Examples of the β-ketoester include alkyl acetoacetate and alkyl acetopropionate. Among them, carbon numbers 1-4 (C1-C
Methyl acetoacetate, ethyl acetoacetate, and isopropyl acetoacetate, which are ketoesters having an alkyl group of 4), are preferred.

The silane compound (b) used in the present invention
Is at least one selected from the group consisting of alkoxysilanes and alkoxysilane oligomers. As the alkoxysilane, a lower alkoxysilane having about 1 to 4 carbon atoms is suitably used. These include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, n-propyltriethoxysilane, vinyltrimethoxysilane, γ-glycid There are xypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane and the like.
Examples of the alkoxysilane oligomer include oligomers obtained by hydrolysis and polycondensation thereof. In particular, oligomers of about 10 to about 10 dimers of the above alkoxysilane are preferred.

The zirconium compound (a) is obtained by mixing a zirconium-containing compound as a raw material with β-diketone and / or β-diketone.
-Formed from ketoester, for example, as follows.

When the zirconium-containing compound as the raw material is zirconium tetrachloride,
A lower alcohol and the above β-diketone and / or β
By reacting -ketoester, a zirconium compound (a) is obtained. In this case, the reaction can be promoted by heating or, if necessary, adding a hydrochloric acid scavenger in a solvent.

When the zirconium-containing compound as the starting material is a zirconium alkoxide, the zirconium compound (a) is obtained by reacting the zirconium alkoxide with the above-mentioned β-diketone and / or β-ketoester. When zirconium alkoxide is used, chloride is not produced as by-product unlike zirconium tetrachloride. Therefore, since hydrogen chloride is not generated by the thermal decomposition of the chloride, the safety is excellent without causing corrosion of the film production apparatus and deterioration of the working environment.

In any of the above cases, it is possible to use either β-diketone or β-ketoester, or a mixture of both.

When the zirconium compound (a) is prepared from the zirconium-containing compound as the raw material and the β-diketone and / or β-ketoester, when the zirconium-containing compound as the raw material is 1, the β-diketone is used. And / or β-ketoester is present in a molar ratio of 0.2 to
It is used at a ratio of 4.0, preferably 0.5 to 4.0, more preferably 1.0 to 3.0. If the amount of β-diketone and / or β-ketoester is too small, the stability of the resulting coordination compound, zirconium compound (a), will be poor. Therefore, for example, when the obtained composition is applied to the surface of the base material by spraying, there is a problem that gelation occurs due to moisture in the air and clogging of piping of the apparatus occurs during spraying. Conversely, β-diketone and / or
Or even if the β-ketoester is in excess, the β-diketone and / or β-
The ketoester is merely present in excess, and does not contribute to the coordination reaction, stability, or film forming property.

In the formed zirconium compound (a), a zirconium atom and a ligand derived from the β-diketone and / or β-ketoester are present in the above molar ratio.

In the above preparation, when the β-diketone and / or β-ketoester is a crystal having a high melting point, a solvent capable of dissolving the crystal may be added. The type of the solvent is not particularly limited as long as it is an organic solvent. For example, any of the solvents described below can be used.

The coating composition of the present invention contains the zirconium compound (a) and the silane compound (b). Usually, it is substantially composed of the zirconium compound (a) and the silane compound (b). Here, “substantially” means that the zirconium compound (a) and the silane compound (b) are substantial components and may contain a solvent or an inert additive as necessary. In the present composition, 1 mol of the zirconium compound (a) is
0.01 to 5.0 mol, preferably 0.02 to 4.0 mol, more preferably 0.05 to 5.0 mol of the silane compound (b).
It is contained at a ratio of 3.0 mol.

As the solvent, it is preferable to use an organic solvent containing no water. This is because the zirconium compound (a) is stable, but may gel if a large amount of water is contained in the solvent. Examples of such a solvent include alcohols such as methanol, ethanol, isopropanol, and n-butanol; and glycol ethers such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, and ethylene glycol monobutyl ether acetate. It can be used, but is not limited to this. When a zirconium alkoxide is used as a raw material of the zirconium compound (a), the zirconium alkoxide and the β-diketone and / or β-ketoester are replaced with the same or compatible solvents in place of the zirconium compound (a). The composition of the present invention can also be obtained by dissolving these components, mixing them, and then adding the silane compound (b).

The concentration (solid content concentration) of such a composition containing the zirconium compound (a) and the silane compound (b) in a solvent is not particularly limited, but usually, the contained compound is converted to oxide. It is preferably 3 to 35% by weight.

The coating composition of the present invention is used to form a protective film, a reinforcing film, etc. on the surface of a substrate and to protect or strengthen the surface of the substrate. For example, when the above coating composition is applied to the surface of a glass substrate and heated, the zirconium compound (a) and the silane compound (b) in the composition are thermally decomposed to form an oxide film on the surface of the glass substrate. Is formed.

Specifically, for example, when the coating composition is applied to a heated glass substrate, the above-mentioned thermal decomposition occurs to form an oxide film. Alternatively, by applying the above-mentioned coating composition to the surface of the glass substrate and baking it, the above-mentioned thermal decomposition occurs to form an oxide film. The temperature or firing temperature of the heated glass substrate is a temperature required for thermal decomposition of organic substances and formation of zirconium oxide or silicon oxide. Such temperatures are between 400 and 700 ° C., preferably 5
00-600 ° C. If the temperature exceeds 700 ° C., the glass is undesirably deformed.

Both the zirconium compound (a) and the silane compound (b) contained in the composition of the present invention have a large number of oxygen atoms around zirconium or silicon atoms. Therefore, when the above calcination is performed, these components are thermally decomposed into zirconium oxide or silicon oxide in a completely oxidized state. Therefore, a film having excellent strength, adhesion to a substrate, and alkali resistance can be obtained.

The means for applying the coating composition is not particularly limited. For example, the composition may be liquid, gaseous,
It is applied to the base material surface in the form of a mist or the like. For example, a composition containing a solvent is applied to the substrate surface by coating, spraying, or the like, and a composition containing no solvent is applied to the substrate surface by chemical vapor deposition or the like. In that case, it is not always necessary to use a carrier gas. When using a carrier gas,
Air, nitrogen gas, oxygen gas, carbon dioxide gas, helium gas,
Argon gas or the like is preferably used, but is not limited thereto. A mixed gas of two or more of these may be used.

The thickness of the oxide formed on the surface of the substrate is not particularly limited, and is appropriately determined depending on the required performance, and is usually 200 to 800 Å. Such a coating protects or strengthens the substrate surface.

The above method is suitably used for protecting or strengthening glass products, especially glass bottles.

Taking a glass bottle as an example, a glass bottle heated to a predetermined temperature is installed in a chamber heated to a predetermined temperature. The coating composition of the present invention is sprayed from a nozzle of a spray gun toward a glass bottle while circulating a carrier gas. This causes the composition to come into mist and partially gaseous and come into contact with the bottle surface. Upon contact with the glass bottle, the zirconium compound and the silane compound are thermally decomposed, and an oxide film containing zirconium oxide and silicon oxide is formed on the bottle surface. The oxide coated bottle is removed from the chamber and slowly cooled. The surface of the glass bottle thus obtained may have some metallic luster, but has no iris and high commercial value. Alkaline durability is also sufficient. The glass bottle obtained in this way is
For example, when immersed in a 4% aqueous solution of alkali hydroxide (for example, sodium hydroxide) at 90 ° C. for 10 hours, the oxide film does not peel off. Since the surface of the glass bottle is strengthened, it is possible to reduce the thickness of the pressure bottle even if it is a pressure-resistant bottle, thereby achieving weight reduction. Such a glass bottle is particularly suitable as a returnable bottle for beer or the like.

[0041]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited to these examples.

Example 1 As a zirconium-containing compound as a raw material, tetra-n-butoxyzirconium (88%
n-butanol solution) 426 g (1.0 mol) and 260 g of ethyl acetoacetate as a β-ketoester
(2.0 mol) was used. By mixing these, a zirconium compound (a) was prepared. Next, 49.4 g (0.43 mol) of a tetramethoxysilane oligomer (MKC silicate MS-51 (manufactured by Mitsubishi Chemical Corporation; mainly pentamer)) was added and mixed as the silane compound (b) to obtain a coating composition. .

The coating composition is used in an amount of from 180 to 25.
A glass bottle having a surface temperature of about 600 ° C. in a chamber at 0 ° C. was applied by a spray method. The coating composition was sprayed onto the glass bottle surface from a distance of 250 mm. The coating composition was in the form of a mist and partially gaseous, and came into contact with the bottle surface, and an oxide film was formed on the bottle surface. The glass bottle on which the oxide film was formed was taken out of the chamber and gradually cooled.

The appearance of the obtained glass bottle was visually observed,
The appearance was evaluated (the presence or absence of the iris was confirmed). The thickness of the formed oxide was measured by ellipsometry. The resulting film thickness was in CTU units and was converted to Angstrom units (CTU is an optical unit used for process control). Next, the obtained glass bottle was heated at 90 ° C.
Dipped in 4% NaOH aqueous solution for 16 hours,
The alkali durability was evaluated every hour. The alkali durability was evaluated by visually observing the state of whitening of the bottle and the state of peeling of the film.

Table 1 shows the type and amount of each component of the coating composition and the evaluation of the obtained glass bottle.

(Examples 2 to 20) Coating was carried out using a zirconium-containing compound as a raw material, ethyl acetoacetate (acetylacetone in Example 20), and a silane compound (b) according to the types and amounts shown in Tables 1 and 2. It is the same as Example 1 except that the composition was obtained.

The results of Examples 2 to 10 are shown in Table 1, and the results of Examples 11 to 20 are shown in Table 2.

(Comparative Example 1) The same as Example 1 except that the silane compound (b) was not used. Table 3 shows the results
Shown in

(Comparative Examples 2 to 4) The amount of silica sol (solid content 3) shown in Table 3 was used instead of using the silane compound (b).
0%). Table 3 shows the results.

In Tables 1 to 3, the unit of the film thickness is angstrom. In the evaluation of alkali durability, the case where whitening of the bottle and peeling of the film did not occur was evaluated as good, the case where the hem or trunk of the film partially whitened or peeled was slightly good, and the bottle was entirely whitened. Alternatively, the case where the coating is peeled off is indicated as defective x.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

[Table 3]

As can be seen from Tables 1 and 2, the glass bottle having an oxide film obtained by using the composition of the present invention is extremely excellent in alkali durability even though the oxide film is formed relatively thin. The appearance is good because the oxide film is thin. On the other hand, Table 3 shows that when the composition of the comparative example containing no silane compound (b) selected from alkoxysilane and alkoxysilane oligomer was used, the alkali durability was clearly inferior.

[0055]

According to the present invention, a coating composition useful for protecting and strengthening a substrate is thus obtained. This composition is suitably used, for example, for strengthening a glass surface, and the reinforced glass product is used in various fields because of its excellent appearance. In particular, when an oxide film is formed on the surface of a glass bottle using this composition, the obtained glass bottle has excellent strength even with a relatively small thickness, so that the glass bottle can be strengthened and reduced in weight. The formed oxide film is extremely excellent in alkali resistance. Therefore, this bottle is suitably used as a returnable bottle that is repeatedly washed with alkali, particularly a pressure-resistant returnable bottle for beer, soft drinks, and the like, and has a long life.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuya Otsuki 5-41 Senju, Itami-shi, Hyogo Prefecture Imperial Chemical Industry Itami Plant Co., Ltd. (72) Inventor Kazuhisa Ishii 5-41 Senmon, Itami-shi, Hyogo Imperial Chemical Industry Co., Ltd. Inside the Itami Plant (72) Inventor Mikio Ueda 1351-1 Izaiza, Himeji-shi, Hyogo Prefecture Asahi Beer Pax Co., Ltd. (72) Inventor Takashi Shiro 1351-1 Imaiza, Shima, Himeji-shi, Hyogo Asahi Beer Pax Co., Ltd. F term (reference) 4G059 AA04 AC16 EA01 EA05 EB07 4J038 DL021 DL031 HA066 HA216 JA34 JC38 MA08 MA10 NA01 NA04 NA11 PA19 PB04 PC03

Claims (10)

[Claims] 1. A zirconium compound (a) to which β-diketone and / or β-ketoester is coordinated, and a silane compound (b) which is at least one selected from the group consisting of alkoxysilane and alkoxysilane oligomer. A coating composition comprising a solvent as required. 2. In the zirconium compound (a), the molar ratio of a zirconium atom to the β-diketone and / or β-ketoester is from 1: 0.2 to 1:
The composition of claim 1, wherein the composition is 4.0. 3. The composition according to claim 1, wherein the β-diketone is acetylacetone. 4. The composition according to claim 1, wherein the β-ketoester is an alkyl acetoacetate (C1 to C4). 5. The composition according to claim 1, wherein the silane compound (b) is contained at a ratio of 0.01 to 5.0 mol with respect to 1 mol of the zirconium compound (a). object. 6. A coating composition according to claim 1, which is applied to the surface of a glass substrate, and the zirconium compound (a) and the silane compound (b) in the composition.
A method for strengthening a glass surface, comprising a step of forming an oxide film on the surface of the glass substrate by thermally decomposing the glass substrate. 7. The method of claim 6, wherein the coating composition is applied to a heated glass substrate. 8. The method for strengthening according to claim 6, comprising a step of applying the coating composition to a surface of a glass substrate and baking. 9. A glass product having an oxide film on a surface, obtained by the method according to claim 6. Description: 10. The glass product according to claim 9, which is a glass bottle.