JP2001192237A - Glass article and method for manufacturing the same and method for cleaning article surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass article which is capable of effectively preventing damage and contamination because of the uniform and dense water-soluble films applied and formed on its surfaces, substantially prevents the erosion of the glass even in a long-term storage, allows the easy removable of the films by water washing and in safe to living things and environment for the high biodegradability of film materials, a method for manufacturing the same and a method for cleaning the article surfaces. SOLUTION: The glass article is obtained by forming part or the whole of its surfaces as clean surfaces and applying and forming protective films consisting of a water-soluble polymer containing the salt of carboxylic acid on these clean surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass article capable of preventing damage to the surface and easily removing dirt even if it adheres, a method of manufacturing the same, and a method of cleaning the surface of the article.

[0002]

2. Description of the Related Art Various types of glass, such as plate glass, bottle glass, tube glass, and glass for electronic components, are manufactured, stored, and transported.
When the glass comes into contact with each other or comes into contact with another member, the surface may be scratched or stained, and such scratches and stains are likely to become product defects.

[0003] In particular, in the case of a glass for a display which requires a high surface quality such as a glass for a cathode ray tube or a glass substrate for a flat panel display, or in which various surface treatments are performed in a later step, it is invisible. A very small amount of dirt is not allowed, and a small amount of organic contaminants adhere to the surface treatment agent applied to the glass article in the subsequent process on the glass surface, which causes a problem of deterioration of film properties due to the repellency. There are cases.

Therefore, for example, in the case of glass for a cathode ray tube, sulfuric acid, nitric acid, hydrofluoric acid, etc. are applied before and after applying a carbon slurry (dug) to the inner and outer surfaces of the funnel glass or applying a fluorescent film to the panel glass. Corrosive acids,
It is necessary to wash the glass with a strong alkali such as sodium hydroxide to remove contaminants such as organic substances attached to the glass surface, and then use the glass.

[0005] However, such a cleaning method has a problem that the cleaning liquid is extremely harmful and dangerous, so that careful handling is required, and that processing of the waste liquid requires a great deal of labor and cost. .

[0006] Therefore, in the production of bottle glass and the like, by blowing sulfurous gas or the like on the surface of a high-temperature glass article, bloom, which is a reaction product with sodium in the glass, is adhered to the surface, and the glass is scratched or culleted. A method has been adopted to prevent the sticking.

[0007] Since this bloom is water-soluble, it can be easily removed only by washing with water. However, in this method, when the peripheral equipment is corroded by sulfur dioxide gas or when the alkali component in the glass is small, it is difficult to remove the bloom. In addition, there is a disadvantage that the product is difficult to precipitate, and it is difficult to accurately control the amount of the product and the precipitation state.

For the purpose of solving such a problem, Japanese Patent Application Laid-Open No. Hei 6-340865 proposes forming a protective film made of a water-soluble salt on the surface of a glass article.

[0009]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Laid-Open Publication No. Hei 6-3
In the glass article disclosed in No. 40865, even when contaminants fly over the protective film, the film is water-soluble, so that it can be removed by washing with water and contaminants adhered thereon can be removed at the same time. .

However, Japanese Patent Application Laid-Open No. 6-340865 discloses sodium tripolyphosphate, sodium sesquicarbonate, and sodium tetraborate as specific examples. However, since these materials are alkaline, they are used in glass articles. When a glass article is stored for a long period of time after being coated on a surface and forming a protective film, an alkali component in the protective film may gradually erode the glass surface, and may impair the appearance quality of the article.

[0011] Further, such a protective film of a water-soluble salt is a physical protective film formed by precipitation of crystals, and has a sea-island-like film distribution. It is difficult to coat uniformly, and there is a possibility that a dirty substance directly adheres to the glass surface due to storage for a long period of time in packing or direct contact with a packing material or sebum, thereby contaminating a glass article.

In particular, sodium tripolyphosphate and sodium tetraborate may harm living organisms and the environment due to phosphorus and boron contained therein.

The present invention has been made in view of the above circumstances, and since a uniform and dense water-soluble film is applied and formed on the surface, damage and contamination can be effectively prevented, and storage for a long period of time. Even when the glass is hardly eroded, the film can be easily removed by washing with water, and the biodegradability of the film material is high, so that a glass article that is safe for living organisms and the environment, a method for manufacturing the same, and a method for manufacturing the article surface It is an object to provide a cleaning method.

[0014]

The glass article of the present invention comprises:
A part or all of the surface is a clean surface, and a protective film made of a water-soluble polymer containing a carboxylic acid salt is formed on the clean surface by coating.

Further, in the method for producing a glass article of the present invention, a part or the whole of a glass article is cleaned, and then an aqueous solution of a water-soluble polymer containing a salt of a carboxylic acid is applied to the cleaned surface. It is characterized in that a protective film made of a water-soluble polymer containing an acid salt is formed.

Further, the method for cleaning the surface of an article according to the present invention comprises:
After a part or all of the surface of the article is cleaned, an aqueous solution of a water-soluble polymer containing a carboxylic acid salt is applied to the clean surface to form a protective film made of a water-soluble polymer containing a carboxylic acid salt. Then, contaminants attached to the surface of the protective film are washed and removed together with the protective film.

[0017]

The glass article of the present invention is a glass article in which part or all of its surface is previously made a clean surface, and a protective film made of a water-soluble polymer containing a salt of carboxylic acid is applied to the clean surface. The protective film can withstand external damage, and the contaminants adhered to the glass article (for example, by flying) can be easily removed by washing with water together with the protective film. can do.

In the present invention, when a protective film made of a water-soluble polymer containing a salt of a carboxylic acid is applied and formed on a clean surface of a glass article, a carboxylate group of the water-soluble polymer which functions as a hydrophilic functional group is formed. Hydrogen bonds with the hydroxyl groups formed directly on the glass surface or by the absorption of water on the surface, resulting in uniform and dense chemical adsorption on the glass surface, which is a hydrophilic surface, and relatively stable Since a film can be formed and a high film strength can be obtained, the film exhibits extremely high performance as a dustproof film for protecting the glass surface from contaminants in the atmosphere.

Furthermore, this membrane has a carboxylate group,
Because it is contained in the covalently bonded polymer chain, when a water-soluble polymer containing a carboxylate is applied to the surface of a glass article to form a protective film, a carboxylate group that is a polar functional group is Chemical adsorption can be specifically performed on the glass surface, which is a polar surface, and a chemically very stable hydrophilic coating can be obtained.

Further, since this film material is neutral, it has the advantage that erosion of the glass surface is unlikely to occur even when it comes into contact with glass for a long period of time, and it also has biodegradability. Since it is high, it is possible to completely treat the waste liquid after washing and removing the protective film.

On the other hand, general organic acids and organic acid salts which are solid at room temperature, such as stearic acid and sodium acetate, contain only one polar functional group which exhibits water solubility in one molecule. Even if a protective film is formed on the glass surface by using, it is difficult to form a uniform protective film and the contamination prevention function is not sufficient, or the water solubility is relatively low, so that the protective film cannot be easily removed by washing with water. There's a problem.
Furthermore, many of these general organic acids and their salts are compared with the water-soluble polymer containing the carboxylic acid salt of the present invention.
Due to poor biodegradability, the waste liquid after washing them may pose an environmental problem.

By the way, especially in the case of a display glass requiring a high surface quality, such as a glass for a cathode ray tube or a glass substrate for a flat display panel, an organic substance or sebum or the like which is volatilized from corrugated cardboard or packing paper during packing and storage or handling. Even if a small amount of contaminants and the like adhere, there is a problem.

However, since the protective film in the present invention is a uniform and dense film having no defects on the clean surface of the glass article as described above, even if organic substances or sebum adhere to the film surface, the protective film is not cleaned. Direct contact with the surface can be prevented. In other words, this protective film prevents contamination of the glass surface due to external factors, and is unlikely to cause scratches on the surface even when glass articles come into contact with each other or with other members.

Since this protective film is very soluble in water, hydrofluoric acid, strong alkali, or the like is used in a subsequent process such as applying a carbon film to a funnel glass or applying a fluorescent film to a panel glass. No need to pre-clean,
It can be easily removed together with contaminants only by washing with water,
A clean surface immediately after the formation of the glass article can be regenerated.

Furthermore, many of the water-soluble polymers containing a salt of a carboxylic acid have very low toxicity, are safe for the human body, and have high biodegradability. The waste liquid can be completely treated.

As the water-soluble polymer containing a carboxylic acid salt used in the present invention, any polymer can be used as long as it is a solid at room temperature and has water solubility. For example, acrylic acid, crotonic acid, isocrotone Acid, methacrylic acid, cinnamic acid, maleic acid, α, such as fumaric acid, sodium or potassium salts of β-unsaturated carboxylic acid, ammonium salt, calcium salt, a polymer containing a monomer such as triethanolamine salt or α, One of the copolymers synthesized from two or more salts of β-unsaturated carboxylic acids
Or a mixture of two or more thereof, and the polymer of the present invention contains components other than the above-mentioned α, β-unsaturated carboxylic acid salt monomer, for example, a hydrophobic monomer or another hydrophilic monomer. There is no problem even when a copolymer is used or a cross-linking agent is used to have a crosslinked structure, as long as the water solubility is not significantly reduced.

Further, the water-soluble polymer containing a salt of a carboxylic acid used in the present invention is particularly polyacrylic because it is extremely high in water solubility and biodegradability, easy to synthesize, inexpensive and easily available. Salts of acids (sodium or potassium salts) and salts of acrylic acid-maleic acid copolymers (sodium or potassium salts) are suitable.

In the present invention, the concentration of the component of the water-soluble polymer containing the salt of the carboxylic acid contained in the aqueous solution is set at 0.1.
It is desirable that the content be 01 to 5% by weight. The reason is that if the concentration of this component is less than 0.01% by weight, the dustproof function is remarkably reduced, while if it exceeds 5% by weight, a large amount of water is required to remove the protective film, This is because swelling with moisture makes it difficult to dry and becomes slippery, which makes it difficult to handle the glass article after coating.

In applying the protective film to the surface of the glass article in the present invention, known methods such as a spray method, a dipping method, a brush coating method and a roller coating method are suitable.
Further, the method for cleaning the surface of an article of the present invention can be applied to various articles made of inorganic materials such as glass, ceramics, and metals. Suitable is a method in which the surface of the glass article is not scratched. Specifically, a method in which the glass article itself is immersed in a water tank or a method in which the protective film is washed away with running water is suitable. As a result, even if contaminants adhere to the protective film, the contaminants are removed from the article together with the protective film that dissolves and desorbs in water, and a clean glass surface is regenerated. In particular, it is preferable to use warm water of 30 ° C. or higher because the protective film can be more easily removed.

If the thickness of the protective film of the present invention is too small, the film is liable to be damaged, and the glass article is easily scratched when rubbed against other members or when the glass articles rub against each other. On the other hand, if the thickness is too large, the operation for removing the protective film takes too much time and the material cost increases, which is not preferable. Therefore, the amount of the protective film adhered is 0.0002 to
100 μg / cm ² and a thickness of 0.001 to 10
It is desirable that the thickness be 00 nm (more preferably 0.01 to 500 nm).

The protective film according to the present invention is not necessarily required to clean the entire surface of the glass article in advance and to apply the protective film over the entire clean surface. In particular, it is necessary to prevent scratches and contaminants from adhering. It may be formed by coating only on a certain portion.

[0032]

The present invention will be described below in detail based on examples and comparative examples.

Example 1 First, a funnel glass for a cathode ray tube was cut into a 50 × 50 mm plate (8 mm thick), washed with 1% HF, and further washed with running water for 10 seconds to clean the surface. And then dried with a dryer.

Next, a 0.2% aqueous solution of sodium polyacrylate was dropped on one surface of the glass plate piece to uniformly wet it, and then dried with a drier, so that the surface of the glass plate piece became polyacrylic. A protective film (thickness: 10 nm) made of sodium acid was formed.

Example 2 A glass plate piece was washed and the surface was cleaned and dried in the same manner as in Example 1, and a 0.2% aqueous solution of an acrylic acid-maleic acid copolymer sodium salt was applied to one surface. After the solution was dropped and uniformly wetted, it was dried with a drier to form a protective film (10 nm thick) made of acrylic acid-maleic acid copolymer sodium salt on the surface of the glass plate piece.

Comparative Example 1 A glass plate piece was washed and the surface was cleaned and dried in the same manner as in Example 1, and a 0.2% aqueous solution of sodium tetraborate was dropped on one surface of the glass plate. After being wet in the same manner as above, a protective film (thickness: 10 nm) made of sodium tetraborate was formed on the surface of the glass plate piece by drying with a drier.

(Comparative Example 2) A glass plate piece was washed and the surface was cleaned and dried in the same manner as in Example 1, and a 0.2% aqueous solution of sodium acetate was dropped on one surface of the glass plate so as to be uniform. After wetting, by drying with a dryer,
A protective film (10 nm thick) made of sodium acetate was formed on the surface of the glass plate piece.

Each of the glass plate pieces of Examples 1 and 2 and Comparative Examples 1 and 2 thus produced was subjected to a dustproof test for cardboard stains. Further, for reference, a similar test was performed on an uncoated product in which a glass plate piece was only washed and dried and no protective film was formed.

The dustproof test was performed as follows. First, inside a glass dish of φ90mm, φ80mm
After placing the glass plate piece with the protective film forming surface facing down, holding the glass plate piece under the conditions of an atmospheric temperature of 80 ° C. and a humidity of 100% for 20 hours, and then taking out the glass plate piece, After immersion in a deionized water bath at 30 ° C. for 30 seconds to remove the film, the film was dried with a dryer. Next, a water drop was dropped on the surface of the glass plate piece on which the protective film had been formed, and the water contact angle was measured using a contact angle meter (FACE CA-D manufactured by Kyowa Interface Chemical Co., Ltd.). The results are shown in Table 1. The smaller the water contact angle is, the better the dust resistance is.

The pH of each aqueous solution used in Examples 1 and 2 and Comparative Examples 1 and 2 was measured, and the values are also shown in Table 1.

[0041]

[Table 1]

From Table 1, the glass plate pieces of Examples 1 and 2 are as follows.
Compared to the glass plate pieces and uncoated products of Comparative Examples 1 and 2, the water contact angle after performing the dustproof test is significantly small, so that the degree of contamination is small and the dustproof performance is high. It can be understood that the cleanliness can be maintained over a long period.

The glass plate pieces of Examples 1 and 2 were immersed in a deionized water bath at 40 ° C. for 30 seconds to remove the film, dried with a drier, and observed with a microscope. No residual film components were observed.

From the above, the protective film formed in the example was applied to the inner and outer surfaces of the funnel glass for a cathode ray tube,
It is presumed that by washing the inner and outer surfaces of the funnel glass with water before applying the carbon film in a later step, repelling of the carbon film by contaminants can be prevented.

After rubbing the surface of the protective film of the glass plate pieces of Examples 1 and 2 once with a load of 40 gr using # 1000 abrasive paper, the glass surface was observed with a microscope. Was missing, but no scratch was found on the glass surface.

[0046]

As described above, the glass article of the present invention has a clean surface made of a water-soluble polymer containing a salt of a carboxylic acid, and a uniform and dense protective film formed on the surface. Can effectively prevent surface scratches and contamination, prevent glass from being eroded even when stored for a long period of time, easily remove the protective film by washing with water, and have high biodegradability of the film material. Can be processed.

Therefore, the glass article of the present invention is suitable as a glass product for a display which requires a high surface quality or is subjected to various surface treatments. When used as a funnel glass for a cathode ray tube, it can be washed with acid or alkali. Becomes unnecessary. Further, by coating and forming a protective film on a functional film of a glass article having various functional films such as a conductive film and an anti-reflection film formed on the surface, it is possible to prevent the functional film from being damaged or contaminated.

According to the method for producing a glass article of the present invention, a uniform and dense water-soluble protective film can be applied and formed on the glass surface. The glass is hardly eroded even when stored.

Further, according to the method for cleaning the surface of an article of the present invention, the protective film can be easily washed and removed together with contaminants.
The article surface can be regenerated to a clean surface before applying the protective film.

Claims (8)

[Claims] 1. A glass article characterized in that a part or all of the surface is a clean surface, and a protective film made of a water-soluble polymer containing a carboxylic acid salt is formed on the clean surface by coating. 2. The glass article according to claim 1, wherein the water-soluble polymer containing a salt of a carboxylic acid is a salt of polyacrylic acid and / or an acrylic acid-maleic acid copolymer. 3. The glass article according to claim 1, wherein the glass article is glass for a cathode ray tube. 4. After a part or the whole of a glass article has been cleaned, an aqueous solution of a water-soluble polymer containing a salt of a carboxylic acid is applied to the clean surface to remove the water-soluble polymer containing a salt of a carboxylic acid. A method of manufacturing a glass article, comprising forming a protective film. 5. The method for producing a glass article according to claim 4, wherein the water-soluble polymer containing a salt of a carboxylic acid is a salt of polyacrylic acid and / or an acrylic acid-maleic acid copolymer. 6. The method for producing a glass article according to claim 4, wherein the component concentration of the water-soluble polymer containing a carboxylic acid salt contained in the aqueous solution is 0.01 to 5% by weight. 7. A method in which a part or all of the surface of an article is cleaned, and an aqueous solution of a water-soluble polymer containing a salt of a carboxylic acid is applied to the clean surface to remove the water-soluble polymer containing a salt of a carboxylic acid. A method for cleaning the surface of an article, comprising: forming a protective film, and washing and removing contaminants attached to the surface of the protective film together with the protective film. 8. The method for cleaning an article surface according to claim 7, wherein the article is a glass article.