KR20080031729A - Glass plate with protective film - Google Patents

Abstract

Disclosed is a protective agent for alkali-free glass plates which is used for protecting an alkali-free glass plate as a member for a liquid crystal display or the like from scratches and fouling during storage and transportation. This protective agent can be removed more easily and completely by water washing when compared with conventional protective agents. In addition, the incidence of malfunction of a liquid crystal display or the like produced by using such a protective agent is remarkably lower than those of conventional ones, and this protective agent is effective even when it is applied to a large-sized glass plate. Also disclosed are a glass plate with protective film wherein the surface of an alkali-free glass plate is provided with a protective film, and a glass laminate obtained by arranging such glass plates in layers. A protective film is formed on the surface of an alkali-free glass plate by using an alkali-free protective agent containing a water-soluble alkali-free organic acid salt.

Description

Glass plate with protective film {GLASS PLATE WITH PROTECTIVE FILM}

This invention relates to the protective agent for protecting the surface of the alkali free glass plate used for uses, such as a liquid crystal display, the glass plate with a protective film which has a protective film on the surface of an alkali free glass, and the glass laminated body which laminated | stacked it.

When using an alkali free glass plate as a glass substrate which inserts an electric circuit etc. in the surface, very high surface characteristic is calculated | required by a glass substrate. For example, when using an alkali free glass plate as a member of a liquid crystal display, even if there are small scratches or contamination on the surface of the alkali free glass plate, the electrical circuit etc. which were formed in the surface generate disconnection or patterning defect, and the factor of a yield fall do.

Scratches or contamination on the surface of the alkali free glass plate may occur during storage and transportation, except in the manufacturing process.

For example, when laminating | stacking and transporting this glass plate, a shift may generate | occur | produce between adjacent glass plates, and the flaw may generate | occur | produce on the glass plate surface. Moreover, the organic substance in a storage and transport atmosphere may adsorb | suck to a glass plate surface, and the glass plate surface may be contaminated. It is difficult to remove this organic substance (contaminant) from the surface only by washing with water, and it is necessary to wash | clean using an acid and an alkali, for example. However, in this case, the working environment at the time of washing | cleaning worsens, and the cost of washing | cleaning and wastewater treatment also increases. Moreover, even if such washing is performed, it is difficult to remove an organic substance completely from the glass plate surface.

As a method for preventing such scratches and stains during storage and transportation, a method may be considered in which a paper is sandwiched between laminated glass plates to protect adjacent glass plate surfaces.

However, in such a method of embedding the paper, since the paper is in direct contact with the glass plate surface, another problem arises that the resin component of the paper is transferred to the glass plate surface to contaminate the glass plate surface.

Therefore, in order to avoid this, the method of using the paper with a small content of a resin component is currently taken.

However, it is practically very difficult to precisely control the amount of resin component transfer from the paper, and such paper is expensive compared to the plain paper and is a factor of the cost increase. Moreover, the cost increase of using paper itself cannot be denied.

As a conventional method related to such a problem, the method of patent documents 1-2 is mentioned, for example.

Patent Document 1 describes a glass product, wherein part or all of the surface is covered with a protective film made of a water-soluble substance dissolved in hot water of 30 ° C. or higher. And as a specific example of this glass product, plate glass, a bottle glass, the glass for electronic components, the glass for flat panel displays, and the glass for CRT are mentioned.

In addition, it is described that the water-soluble substance is one or two or more selected from the group consisting of esters, ester aggregates, alcohol aggregates, ester alcohol copolymers, and mixtures thereof.

And since this glass article forms the protective film which consists of water-soluble substances on the surface, it can suppress the generation | occurrence | production of the scratch which arises in a glass article, and also adheres to a glass article through a protective film even if a contaminant will fly to the glass article surface. It is described that it is not directly attached to the glass surface, so that the contaminants can be removed together with the protective film when the glass product is washed with hot water of 30 ° C. or higher.

In addition, Patent Document 2 discloses that in a glass product in which a protective film made of a water-soluble substance is coated on a part or all of the surface, the electrically water-soluble substance is made of polyvinyl alcohol having an average polymerization degree of 600 or less and a saponification degree of 40 mol% or more. Characterized glass articles are described. And as a specific example of this glass product, plate glass, a bottle glass, the glass for electronic components, the glass for flat panel displays, and the glass for CRT are mentioned.

And since such a glass product can prevent the damage and contamination of a surface effectively by a protective film, and an alkali component is not contained in a protective film, the surface is not eroded by an alkaline component, and this protective film is a water-soluble salt. Since water solubility is low compared with the protective film which consists of, it is described as having the advantage that it is hard to melt | dissolve even if dew condensation generate | occur | produces on the glass surface.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-167761

Patent Document 2: Japanese Patent Application Laid-Open No. 10-226537

Disclosure of the Invention

Challenges the invention seeks to solve

However, when the method described in patent documents 1-2 is applied to an alkali free glass plate, and the film | membrane which consists of water-soluble substances etc. is formed in the surface, only the subsequent water washing cannot remove it completely, and the electricity formed in this alkali free glass plate Circuit breakage, poor patterning, or malfunction may occur.

Moreover, in recent years, enlargement and the high precision of a glass substrate are advanced. In particular, the incidence rate of malfunctions such as liquid crystal displays tends to increase with high precision of recent glass substrates. One cause of malfunctions, such as a liquid crystal display, is estimated to remain | survive on the alkali-free glass surface, such as said water-soluble substance, and it is desired that a water-soluble substance does not remain on the alkali-free glass surface as much as possible.

Thus, the glass plate used for a liquid crystal display etc. especially requires high surface characteristics compared with other glass, and the performance improvement as a protective agent for glass plates of the water-soluble substance apply | coated to the glass surface described in patent documents 1-2 is It is getting higher recently.

Therefore, this invention prevents the scratches and contamination of the alkali free glass plate used for members, such as a liquid crystal display, during transportation, and is easy compared with the past, and can wash | clean water removal more completely, and the liquid crystal produced using this The incidence of malfunctions such as displays is significantly lower than in the prior art, and a glass plate with a protective film having a protective film formed of this protective agent on the surface of an alkali-free glass plate and an alkali-free glass that can exhibit its effects even when applied to a large glass plate. And the glass laminated body which laminated | stacked it.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM This inventor examined the cause which the liquid crystal display manufactured using the alkali free glass plate to which the conventional method as described in the above-mentioned patent documents 1-2 applied, etc. malfunctions, or the formed film cannot be removed completely only by washing with water. .

And the cause was found that in a kind of water-soluble substance etc. which apply | coat to the surface of an alkali free glass plate, using a specific water-soluble substance can solve this problem.

That is, this invention provides the following (1)-(9).

(1) The protective agent for alkali free glass plates containing water-soluble alkali free organic acid salt and being alkali free.

(2) The glass plate with a protective film containing water-soluble alkali-free organic acid salt and having an alkali free protective film on the at least one main surface of an alkali free glass plate.

(3) The glass plate with a protective film as described in said (2) whose said water-soluble alkali free organic acid salt is an alkali free carboxylate of a saccharide.

(4) The glass plate with a protective film as described in said (3) whose alkali free carboxylate of the said saccharide is an alkali free carboxylate of a polysaccharide.

(5) The glass plate with a protective film as described in said (4) whose alkali-free carboxylate of the said polysaccharide is ammonium alginate.

(6) The glass plate with a protective film in any one of said (2)-(5) which has a functional thin film further between the main surface of the said alkali free glass plate and the said protective film.

(7) The glass plate with a protective film in any one of said (2)-(6) whose thickness of an electrical protective film is 0.2-100 micrometers.

(8) An alkali free glass plate which washed with water the glass plate with a protective film in any one of said (2)-(7), and removed at least one part of the said protective film from the main surface of the said alkali free glass plate or the said functional thin film phase.

(9) The glass laminated body which laminated | stacked at least 2 or more sheets of the glass plate with a protective film in any one of said (2)-(7).

Effects of the Invention

The alkali free glass plate used for uses, such as a liquid crystal display in which the protective film was formed on the surface using such a protective agent, and the glass laminated body which laminated | stacked are prevented the damage and the contamination during storage and transportation. Moreover, compared with the conventional method, the protective film can be washed off more easily and completely, and the cleanliness of the glass surface can be restored. Moreover, the incidence rate of malfunctions, such as a liquid crystal display manufactured using this, can be made significantly lower compared with the former. Moreover, even when the glass plate is large, the effect can be exhibited.

1 is a side sectional view showing a glass with a protective film of the present invention.

Explanation of the sign

1 ... glass plate with protective film

10 boards

20 ... shield

Implement the invention  Best form for

This invention is a protective agent for alkali free glass plates containing a water-soluble alkali free organic acid salt, and being alkali free. In addition, an alkali free glass means the glass which does not contain alkali content substantially.

That is, this invention contains water-soluble alkali-free organic acid salt in the solution used for apply | coating to the surface of the alkali free glass plate for liquid crystal displays, etc., and to form a protective film on the surface of this glass plate, and is an alkali free protective agent. .

Such a protective agent is also called "protective agent of this invention" below.

The protective agent of the present invention is alkali free, and this "alkali free" means that the protective agent of the present invention does not substantially contain an alkali component. Specifically, it means that the alkali component content rate is 50 ppm or less with respect to the total mass of the protective agent of the present invention, and it is preferably 10 ppm or less, particularly 5 ppm or less.

Therefore, the alkali component content rate of the "water-soluble alkali free organic acid salt" contained in the protective agent of this invention itself is a range which does not contain an alkali component substantially.

In addition, the content rate of the alkali component in the protective agent of this invention is a value measured by ICP emission analysis by appropriately diluting the liquid obtained by carrying out wet decomposition using concentrated acetic acid and concentrated sulfuric acid after drying the protective agent of this invention. .

Moreover, an "alkali" means an alkali metal element (lithium, sodium, potassium, rubidium, cesium, francium). In a protective agent, "alkali free" means that substantially no such alkali metal element is contained in a protective agent. In addition, "alkali free" of an alkali free glass means that alkali is not substantially contained in glass as mentioned later.

Moreover, "organic acid" of "a water-soluble alkali free organic acid salt" is an organic compound which has the property of an acid, and is an organic compound which has a carboxyl group, a sulfonic acid group, etc.

Moreover, an "organic acid salt" is an organic compound which has a structure in which one part or all part of hydrogen atoms, such as this carboxyl group and sulfonic acid group, were substituted by cation (ammonium ion, metal ion, etc.).

In addition, the "water-soluble" in "a water-soluble alkali free organic acid salt" means that the protective film formed by apply | coating the protective agent containing this to the alkali free glass plate has solubility to the extent that water washing removal is possible.

Here, the "washing water can be removed" means that "the contact angle between water and the glass plate surface becomes 15 degrees or less" by "washing water treatment", and also by X-ray photoelectron spectroscopy (XPS) When surface analysis is performed, it is said that the residual rate of water-soluble alkali-free organic acid salt is low, so that the component of this protective film becomes below detection lower limit (0.1 atomic% or less). For flat panel displays such as liquid crystals, PDPs, organic ELs, inorganic ELs, field emission displays, and fluorescent display tubes, very high cleanliness is required in view of securing the performance. In this respect, it is important to form a protective film using a protective agent of a component that can be washed off with water.

Here, "washing treatment" uses the protective agent containing this water-soluble alkali-free organic acid salt, and uses the protective film formed on the glass plate by the conventional method (for example, water of the temperature of 20 degreeC to 3 liters / minute). Washing with a method of spraying on a protective film on a glass plate using a general domestic shower or the like for 30 seconds. Such water washing process is also especially called "water washing process A" below.

In addition, "the contact angle of water and a glass plate surface becomes 15 degrees or less" here means that the contact angle measured by the dropping method in JIS-R3257 (1999) becomes 15 degrees or less. Such a measuring method of contact angle by JIS-R3257 is also called "contact angle measuring method A" below. In addition, in this invention, when only a contact angle is used, all are the contact angles measured by this method. Moreover, as for a contact angle, 10 degrees or less, especially 5 degrees or less are preferable.

The protective agent of this invention contains such an aqueous alkali-free organic acid salt in the solution which does not contain the substantially alkaline component mentioned later, and contains an alkali component substantially also when it contains the water-soluble film structural component mentioned later and other components. I never do that. Therefore, the protective agent of this invention does not contain an alkali component substantially.

In addition, the protective agent of the present invention prevents scratches and contamination during storage and transportation of the alkali-free glass plate used in the production of liquid crystal displays and the like, and is simpler than conventional ones, and can be removed from the glass plate surface with water. Thereby, the incidence rate of malfunctions, such as a liquid crystal display manufactured using the alkali free glass plate from which the protective agent was water-washed off, is remarkably low compared with the past.

Here, the protective film which consists of a protective agent of this invention is simple compared with the past, and can wash | clean water removal from the glass plate surface more completely. The degree is considerably high compared with the case of washing the film | membrane which consists of polyvinyl alcohol (PVA) as described in patent document 2, for example. Specifically, the above water washing treatment A is performed on the film made of this PVA, and the contact angle is measured by the contact angle measuring method A, and the value is about 20 to 30 degrees. The same applies to vinyl acetate vinyl alcohol polymers described in Patent Document 1.

Moreover, even if it measured by XPS mentioned later, this inventor confirmed that when the film | membrane which consists of PVA was formed in the glass plate surface and washed with water, a little PVA remained on the glass plate surface.

On the other hand, after apply | coating the protective agent of this invention on the glass plate surface, and forming a film | membrane, and washing with water under the same conditions, the protective agent of this invention is removed completely and does not remain. This inventor measured the contact angle as mentioned above, and confirmed this by the thing whose value becomes 15 degrees or less, and XPS inspection.

In the protective agent of the present invention, the water-soluble alkali-free organic acid salt is preferably an alkali-free carboxylate salt. This is because, when applied to a glass plate, a uniform protective film is more easily formed, and since it is a salt, the dissolution rate with respect to water is faster than that of acid, and the removal by washing with water is easy. Organic salts are preferable because they are ionic (consisting of a combination of cations and anions), and are easily separated into cations in water and exhibit high solubility.

Here, saccharides are mainly monosaccharides, small sugars, and polysaccharides shown below.

The protective film containing these sugars apply | coated and formed on the surface of a glass plate can be removed with water. That is, when the above-mentioned water washing process A is performed, the measurement result of the contact angle measuring method A will be 15 degrees or less in contact angle, and when the surface analysis by XPS is performed, the component of a protective film will be below a detection lower limit.

As this monosaccharide, glucose, fructose, galactose, etc. are mentioned, for example.

Moreover, with "mono-alkali-free carboxylic acid", the thing which does not contain an alkali component substantially as uronic acid (galacturonic acid, glucuronic acid, an iduronic acid etc.) etc. is mentioned, for example.

The term "alkali-free alkali carboxylate" includes, for example, a part or all of the carboxyl groups of this uronic acid substituted with cations (ammonium ions, metal ions (Ca, Mg, etc.), etc.). have.

Moreover, as a small sugar, sucrose, maltose, lactose, etc. are mentioned, for example.

Moreover, it is preferable that the alkali free carboxylate of this saccharide is an alkali free carboxylate of a polysaccharide. This is because, when applied to a glass plate, a uniform protective film is more easily formed, and since it is a salt, the dissolution rate with respect to water is faster than that of an acid, and removal by water washing is easy.

Here, as a polysaccharide, a homo polysaccharide may be sufficient and a hetero polysaccharide may be sufficient.

Specifically, if it is a homo polysaccharide, starch, glycogen, cellulose, inulin, mannan, etc. are mentioned, for example. If it is a hetero polysaccharide, glucomannan, agar, etc. are mentioned, for example.

Moreover, as "alkali-free alkali carboxylic acid", alginic acid, hyaluronic acid, chondroitin, heparin, etc. are mentioned, for example.

Moreover, as "an alkali free carboxylate of polysaccharide", the thing by which one part or all part of carboxyl groups, such as alginic acid, hyaluronic acid, chondroitin, heparin, was substituted by cation (ammonium ion, heparin ion, etc.) etc. is mentioned, for example. have.

Moreover, it is preferable that the alkali free carboxylate of this polysaccharide is ammonium alginate. It is because it can apply | coat uniformly to the glass plate surface easily with the thickness required as a protective film, Moreover, by washing with water, it is more easily and can remove from a glass plate completely more completely. It is also because the material cost is low and the biodegradability is high, and therefore, it is an environmentally friendly material, and is suitable for industrial use.

The reason why alginate can be easily removed by washing with water is that (1) the amount of alcoholic OH in the molecule is small and the interaction with the glass surface is less likely to be adsorbed, and (2) the carboxyl group becomes an ammonium salt. (3) Crystalline salts have a large amount of dissolution to and fast dissolution rate. (3) Crystalline salts generate grain boundaries due to microcrystallization, so the surface cannot be completely covered at the molecular level, but alginate is an ionic polymer. Since it is amorphous, there is no grain boundary, and it is estimated that it can form a film and can cover the surface uniformly. In addition, the alginic acid has a skeleton of uronic acid that is not a glucose.

Here, it is preferable that the viscosity of the protective agent of this invention is 350-500 mPa * s in 20 degreeC and pH6-8. If it is such a viscosity, it is because water washing can form a protective film which is more easily removed from a glass substrate more completely, and does not melt | dissolve with the dew condensation which arises during storage and transport. Moreover, it is preferable that the protective agent of this invention is not gelatinized from the point which is excellent in the cleanliness of the glass plate after water washing.

The protective agent of the present invention may contain two or more kinds of water-soluble alkali-free organic acid salts as described above. Even in that case, it is within the scope of the present invention.

Such a protective agent of the present invention, the effect of the water-soluble alkali-free organic acid salt as described above in a solution (a mixture of a solvent, a water-soluble alkali-free organic acid salt, a water-soluble film constituent component described later, and other components described later) What is necessary is just to contain in arbitrary ratio shown. It is preferable that content in the protective agent of water-soluble alkali organic acid salt is 0.005-90.00 mass%, It is more preferable that it is 0.005-5.0 mass%, It is most preferable that it is 0.005-3.0 mass%. Such concentration makes it easy to adjust the film thickness of the protective film after drying and to remove the protective film at the time of washing with water, which is preferable also from the viewpoint of cost and wastewater treatment.

Here, the solvent which dissolves the water-soluble alkali-free organic acid salt is substantially free of an alkaline component, preferably water, and more preferably free of substantially alkaline components such as distilled water and ion-exchanged water. It is because it is industrially advantageous if it is water, since the treatment of the wastewater which arises at the time of protective film formation further after application | coating to a glass plate is also easy.

The protective agent of the present invention contains the water-soluble alkali-free organic acid salt with water or the like as described above, and the protective agent of the present invention is a water-soluble film constituent or other You may contain a component.

A water-soluble film component is a substance other than a water-soluble alkali free acid salt, and when it is apply | coated on a glass plate, it comprises a film and has some water solubility, Specifically, a water-soluble polymer, water-soluble organic salt, and water-soluble inorganic salt At least 1 type selected from is preferable. Moreover, even when a water-soluble film component contains in a protective agent, the protective agent of this invention needs to be alkali free. When the water-soluble alkali-free organic acid salt and the water-soluble film component are mixed in the protective agent of the present invention, the ratio of the water-soluble alkali-free organic acid salt is 50 mass% or more, especially with respect to the total amount of the water-soluble alkali-free organic acid salt and the water-soluble film component. It is preferable that it is 80 mass% or more, Furthermore, it is preferable that it is substantially 100 mass%. In addition, the ratio of this water-soluble alkali-free organic acid salt is the same also when it is a protective film in the glass plate with a protective film of this invention mentioned later.

Here, examples of the water-soluble polymer include hyaluronic acid, trehalose, and pullulan. Examples of water-soluble inorganic salts include carbonates, nitrates, sulfates, phosphates, silicates, and borate salts. The ammonium carbonate salt, ammonium nitrate salt, ammonium sulfate salt, ammonium phosphate salt, ammonium silicate salt, ammonium borate salt, etc. are mentioned.

As other components, surfactant, a dispersing agent, an antifoamer, an antistatic agent, etc. can be contained, for example.

As surfactant which does not contain an alkali component substantially, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonyl phenyl ether is mentioned, for example.

It is preferable to contain such surfactant in the protective agent of the present invention because a protective film can be formed with a more uniform thickness when the surface of the alkali-free glass plate is coated or the like.

Although the protective agent of this invention can contain such another component in the range which does not impair the effect of this invention, It is preferable that it is 0.001-1 mass% in the protective agent (solution), and it is 0.005-0.5 mass% More preferably, it is most preferable that it is 0.01-0.1 mass%.

Such protective agent of this invention can be apply | coated on at least one main surface of the alkali free glass plate mentioned later, and a protective film can be formed. 1 is an enlarged view of a side cross section of the glass plate with a protective film of the present invention thus formed. The glass plate 1 with a protective film is formed by using the protective agent of this invention on the main surface of a board | substrate (alkali glass plate; 10), and forming the protective film 20. FIG.

Next, the formation method of this protective film is illustrated.

The method of apply | coating the protective agent of this invention to the surface of an alkali free glass plate can apply well-known methods, such as an immersion method, a spray method, screen printing, and a brush application method. Here, it is not necessary to apply | coat all the surface of a glass substrate, etc., and may form only in the part which needs to prevent a damage | wound and adhesion of an organic substance (contaminant).

In addition, before applying the protective agent of this invention to the surface of an alkali free glass plate by such a method, it is preferable to wash this glass plate surface with a weak acid, a weak alkali aqueous solution, etc., and to make it a clean surface. Especially in the case of this invention, it is preferable that alkali content does not remain on the surface.

In this method, after forming the protective film by apply | coating the protective agent of this invention, this protective film is dried. As a drying method, various methods, such as natural drying and rapid drying by jet airflow, are applicable. However, from the viewpoint of film thickness control, it is preferable to use a rapid drying method by jet airflow (for example, drying by a jet fan).

When such a drying operation is performed, solvents such as water are dried and substantially removed from the protective film, and thus the protective film itself is mainly the above-mentioned water-soluble alkali-free organic acid salt, a water-soluble film constituent component added as necessary, and other components. .

In this way, the protective agent of this invention is apply | coated on at least one main surface of an alkali free glass plate, and a protective film is formed.

Or the protective agent of this invention is apply | coated on the thin film of the alkali free glass plate in which the functional thin film was formed on at least one main surface, and a protective film is formed. That is, it is also possible to set it as the glass plate with a protective film which further has a functional thin film between the main surface of the said alkali free glass plate and an electrical protective film. Also in the case of having a functional thin film, since the protective agent of the present invention is used, the film or glass plate can be sufficiently protected without affecting the functional thin film.

The glass plate with a protective film which contains the water-soluble alkali free organic acid salt which can be manufactured by such a method, and has an alkali-free protective film on the at least one main surface of an alkali free glass plate is called "the glass plate with a protective film of this invention below". Also called. This protective film is also referred to as "protective film of the present invention".

In addition, the "water-soluble" and "organic acid salt" in the "water-soluble alkali free organic acid salt" in a protective film are as mentioned above, and "alkali free" does not contain an alkali component substantially, specifically, The alkali component in the protective film of the present invention is 30000 ppm or less, particularly preferably 10000 ppm or less, and 5000 ppm or less.

With respect to such a glass plate with a protective film of the present invention, the water-soluble alkali-free organic acid salt is preferably an alkali-free carboxylate salt of the above-mentioned sugars.

Moreover, it is preferable that the alkali free carboxylate of this saccharide is an alkali free carboxylic acid salt of the said polysaccharide.

Moreover, it is preferable that the alkali free carboxylate of this polysaccharide is the said ammonium alginate. In addition, a saccharide and an alkali free carboxylate are as having mentioned above.

Moreover, although the protective film of this invention contains a water-soluble alkali-free organic acid salt, if it does not contain an alkali component substantially, you may contain a water-soluble film structural component and other components. Specific examples and ratios of the water-soluble membrane components and specific examples and ratios of the other components are as described above.

The incidence of malfunctions such as liquid crystal displays manufactured by washing and using the glass plate with a protective film of the present invention is significantly lower than in the prior art, and the present inventor estimates that this is due to the following reason.

When the protective film of the conventional method as described above remains slightly without being completely removed from the glass plate surface by washing with water, peeling due to a decrease in the adhesive strength of the thin film occurs in thin film coating or the like in a later step, resulting in poor patterning. And it is thought that the manufactured liquid crystal display etc. cause malfunction. In TFT-LCD applications, short circuits between parallel wirings, short circuits between upper and lower wirings due to interlayer insulation film defects, short circuits of display electrodes and wirings, and the like cause a decrease in yield.

Moreover, when the conventional protective agent containing an alkali component is used, the protective film of the conventional method of the glass plate surface formed by apply | coating it etc. also contains an alkali component. In this case, there is a possibility that the alkali component moves from the protective film of the conventional method to the glass plate surface part by some chemical and physical action. And the liquid crystal display manufactured using the glass plate which has an alkali component on the surface is considered to cause malfunction.

On the other hand, the protective film of this invention does not contain an alkali component substantially. Moreover, it can be easily and completely removed by water washing. Therefore, it is thought that the malfunction of the liquid crystal display etc. which were manufactured from the alkali free glass plate after water-removing the protective film of this invention can be prevented.

Moreover, as mentioned above, the residual ratio on the surface of an alkali-free glass plate, such as a water-soluble substance, and the malfunction ratio, such as a liquid crystal display, are becoming high with the enlargement and high precision of a glass plate in recent years. It is estimated as follows.

When transporting the glass plate for a large area liquid crystal display like the 6th generation which was developed recently, it is difficult to incline a glass plate and it has to be stacked and transported in many cases. For this reason, the adhesion rate of the glass plate and the protective film which consists of water-soluble substances, etc. increases, and also the load applied to this protective film also increases. By any of the above chemical and physical actions, it is thought that the movement of the alkali component in the protective film to the glass substrate increases, or the residual ratio of the protective film after washing with the glass substrate further increases.

However, according to the protective film of this invention, even if it is a large alkali free glass board | substrate, there is no movement of alkali powder and there is little possibility that the protective film of this invention remains, and the effect is high.

Moreover, when transporting a glass plate, it is usual to transport in the state which sandwiched the paper called paper between glass plates. The resin usually contains a resin powder (mainly carbon), and when the paper is sandwiched in the glass plate, the resin powder may be transferred onto the glass plate surface, and the glass plate may not be usable for the liquid crystal display. In the case of flat and transporting as described above, the possibility of this transfer is further increased. By using the protective film of this invention, it becomes possible to suppress such transfer.

In the glass plate with a protective film of this invention, an "alkali free glass plate" means the glass plate whose content rate of an alkali component is 0.15 mass% or less with respect to the total mass of a glass plate. It is preferable that the content rate of an alkali component is 0.05 mass% or less.

"Alkali" is an alkali metal element shown by the protective agent of said this invention here.

The composition other than the alkali of the "alkali-free glass" is, for _{example, 68% ≤SiO 2 ≤80%,} 0% ≤Al 2 O 3 <12%, 0% <B 2 O 3 <7%, 0 % <MgO <= 12%, 0% <= CaO <15%, 0% <SrO <= 4%, 0% <= BaO <= 1% are mentioned. Here,% means mass%.

Moreover, the method of manufacturing this alkali free glass is not specifically limited, Various manufacturing methods can be employ | adopted. For example, the raw material normally used so that it may become the said composition is prepared, and it heats and melts at 1500 degreeC-1700 degreeC in a melting furnace. Homogenization of glass is performed by bubbling, addition of a clarifier, stirring, etc. When used as a substrate for display or photomask substrate such as a liquid crystal display, it is molded to a predetermined plate thickness by a known press method, a down draw method, a float method, etc., and after cooling, grinding, polishing, etc. Processing is carried out to obtain a substrate having a predetermined size and shape.

Moreover, the shape, size, thickness, etc. of the glass plate of the alkali free glass plate in the glass plate with a protective film of this invention are not specifically limited.

The glass plate with a protective film of this invention can be used for a liquid crystal display very preferably.

When the glass plate with a protective film of this invention is used for a liquid crystal display, generation | occurrence | production of the surface contamination and a flaw which causes malfunction of a liquid crystal device can be suppressed, and it becomes possible to reduce the ratio of inconvenience. Moreover, it has the effect that the frequency of splitting at the time of conveyance or handling of a glass plate can be reduced.

When using the glass plate with a protective film of this invention as a member of a liquid crystal display, an alkali free glass plate has the magnitude | size of the 6th generation (1500mm x 1800mm) developed recently, for example. About this invention, the effect is exhibited even more in the glass plate which has a magnitude | size of 1500 mm x 1800 mm or more. Moreover, it is preferable that the thickness of a glass plate is 0.3-0.8 mm from a viewpoint of strength ensuring, More preferably, it is about 0.5-0.7 mm.

Although the thickness of the protective film of this invention which the glass plate with a protective film of this invention has is not specifically limited, It is preferable that it is 0.2-100 micrometers, It is more preferable that it is 0.2-10 micrometers, It is most preferable that it is 0.2-5 micrometers. This is because a uniform protective film can be formed more easily when the glass plate is coated or the like, and can be removed more easily by washing with water. The protective film of the present invention is preferable because such a film thickness can prevent the occurrence of scratches over a wide range.

It is necessary that the protective film of this invention does not contain an alkali free, ie, an alkali component substantially. Specifically, it is preferable that the alkali component in the protective film of this invention is 30000 ppm or less, 10000 ppm or less, especially 5000 ppm or less.

In addition, the alkali component content rate of this protective film of this invention is the value measured by ICP emission analysis after the liquid part of the protective film of this invention was wet-decomposed with concentrated acetic acid and concentrated sulfuric acid, and the liquid obtained was diluted suitably.

As mentioned above, the glass plate with a protective film of this invention contains the above water-soluble alkali-free organic acid salt, and has a protective film which is alkali free on at least one main surface of the alkali free glass plate, or at least one part on the said functional thin film. It is an alkali free glass.

Here, a functional thin film means functional films, such as a conductive film and a heat ray shielding film, which are formed on the main surface of an alkali free glass plate, for example, when manufacturing a liquid crystal display.

For example, the conductive film as indium oxide (ITO), zinc oxide (ZnO), tin oxide containing tin oxide (SnO _2), may be a thin film made of Ag, Cr / Cu / Cr. Al, Ga, hydrogen, or the like may be doped with zinc oxide. F or Sb may be doped with tin oxide. In the Ag film, Pd and Au may be doped.

Moreover, as a heat ray shielding film, the thin film which has a structure of oxide (for example, zinc oxide, titanium oxide, ITO etc.) / Ag / oxide is mentioned.

The property, thickness, formation method, and the like of such a functional thin film are not particularly limited, and conventionally known ones can be used.

When storing and transporting such a glass plate with a protective film of this invention, it is usually preferable to laminate | stack at least 2 or more sheets, and to set it as a glass laminated body.

Such a glass laminated body is also called the glass laminated body of this invention.

As long as the glass laminated body of this invention laminated | stacked two or more glass plates with a protective film of this invention, size, the number of sheets, etc. are not specifically limited. You may sandwich the paper between the glass plates.

For example, about 100-500 sheets of glass substrates of a 6th generation size can be laminated | stacked. Moreover, when about 500 sheets of glass substrates of a 6th generation size are laminated | stacked, if it is the glass laminated body of this invention which sandwiched the paper between all the glass substrates, it will be about 1500 mm x 1800 mm x 386 mm.

After storing and transporting the glass plate with a protective film of this invention as mentioned above in a laminated body, it uses for manufacturing sites, such as electronic circuits, such as a liquid crystal display. Moreover, it can use not only a liquid crystal display but also various displays, such as FED, and a photomask board | substrate. In addition, it can also be used for functional glass, such as low-emissivity glass, which is given to building glass windows and automotive glass windows.

And the glass plate with a protective film of this invention is washed with water, and at least one part, preferably all the protective film of this invention which exists in the surface is removed from the main surface image or the electrically functional thin film phase of a glass plate. In this way, the alkali-free glass plate from which the protective film of the present invention has been removed has almost no scratches or stains even after storage and transportation. Moreover, the incidence rate of the malfunction of the liquid crystal display manufactured using this is remarkably low compared with the past. Moreover, also in the case of a large glass substrate, it has the effect.

The alkali free glass plate with which such a glass plate with a protective film of this invention was washed with water, and the protective film of this invention was removed from the surface is novel in the point that there are few scratches and contamination after storing and transport compared with the past.

Example

<Glass Plate for Liquid Crystal Display Coated Ammonium Alginate>

<Example 1>

Four pieces of the alkali-free glass plates for liquid crystal displays of 0.7 mm thickness were cut out at a width of 5x5 cm. Each glass piece was immersed in 0.01 mol / liter of NaOH aqueous solution for 30 seconds, and then washed with water to blow out a nitrogen blower to dry. Residual alkali was not confirmed on the glass plate surface.

Subsequently, these four glass pieces were coated with an aqueous solution (using pure water) of ammonium alginate (trade name: Kimika Algin, manufactured by Kimika Co., Ltd.) by brush coating, and rapidly dried with a nitrogen blower to the surface of each glass piece. A protective film of ammonium alginate was formed.

Here, the density | concentration of the used ammonium alginate aqueous solution was 0.01 mass%, and the alkali content was 1 ppm or less.

Moreover, as a result of measuring the film thickness of the four glass piece surface protective films obtained here using a micrometer and a scanning electron microscope (cross-section observation), all four were 0.5 micrometer. In addition, the film thickness of a protective film was measured by the same method below. Moreover, the alkali powder in the protective film was 5000 ppm.

The four glass pieces with a protective film obtained here are called glass plate 1-a, glass plate 1-b, glass plate 1-c, and glass plate 1-d.

The obtained protective film was evaluated by the following method.

<Scratch evaluation (A)>

The glass plates 1-a and 1-b were put into the constant temperature and humidity tank, and the heat cycle test shown below was done. Then, these test pieces were taken out and the friction test was done with the load of 20 g / cm <2> using the 1500-time abrasive paper with respect to glass plate 1-a. Specifically, first, the glass plate 1-a was placed on a horizontal mount so that the protective film was placed thereon, and the abrasive paper 1500 was placed on the protective film, and a load of 20 g / cm 2 was applied from the upper surface in the vertical downward direction. And the glass plate with a protective film was taken out at the speed of 10 cm / s in the horizontal direction. Then, after wash | cleaning this glass plate 1-a with a shower for 30 second under 20 degreeC pure water (3 liter / min), the presence or absence of a scratch was evaluated.

In addition, this water washing condition is the same as that of Example 1 of patent document 2.

The results are shown in Table 1. In Table 1, "none" means that no scratches are observed even when visually observed under a high brightness light source, and "with" means that scratches are confirmed when visually observed under a high brightness light source. same.

<Heat cycle test>

(1) 10 minutes at temperature 20 ℃ and relative humidity 50% →

(2) 5 hours at 50 ℃ and 80% relative humidity →

(3) 5 hours at temperature 20 ℃ and relative humidity 80% →

(4) Return to (2), repeat (5) and (3) five times, and then proceed to (5).

(5) 2 hours at temperature 20 ℃, relative humidity 50%

<Scratch evaluation (B)>

The glass plate 1-b after performing a heat cycle test in a constant temperature and humidity bath was used for the friction test by 20 g load using the sapphire needle. The sapphire needle used the thing of 0.8 mmΦ.

Specifically, first, the glass plate 1-b was placed on a horizontal mount so that the protective film was on top.

Subsequently, a sapphire needle was placed on the protective film, and a load of 20 g was applied in the vertical direction from the upper surface thereof. And the glass plate with a protective film was taken out at the speed of 1 cm / s in a horizontal direction. Then, after wash | cleaning this glass plate 1-b with a shower for 30 second under 20 degreeC pure water (3 liter / min), the presence or absence of a scratch was evaluated.

The results are shown in Table 1. In addition, in Table 1, "nothing" means that no scratches are recognized at all by the naked eye under a high-brightness light source, and "with" means that the scratches were confirmed when visually observed under a high-brightness light source. same.

<Measurement of contact angle>

Glass plate 1-c was subjected to the test defined by ASTM D 4728-95. The glass plate provided for this test can be considered to be the same as the glass plate after transporting by truck.

Thereafter, the glass plate 1-c was washed with water for 30 seconds under a flow of 20 ° C of pure water (3 liters / minute).

The contact angle of glass plate 1-c and water was measured by said contact angle measuring method A (JIS-R3257) (contact angle meter: CA-A by Kyowa Interface Science). As a result, the contact angle was 8 degrees (Table 1). This value is about the same as the surface contact angle of the glass plate itself immediately after manufacture. Moreover, when the residual of the glass plate surface protection film was investigated by XPS apparatus (PHI 5500), it was below a detection limit and it was not able to detect. From the above result, it turned out that ammonium alginate does not remain on the glass plate surface.

In addition, as a result of measuring glass plate 1-c by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS), ammonium alginate was not detected. From this, it was confirmed again that the protective film of ammonium alginate was completely removed from the surface of glass plate 1-c by said water washing.

<Measurement of peak intensity ratio (C1s / Si2p) by XPS>

Glass plate 1-d was provided for the test defined by ASTM D 4728-95. The glass plate provided for this test can be considered to be the same as the glass plate after transporting by truck.

Thereafter, the glass plate 1-d was washed with water for 30 seconds under a flow of 20 ° C. pure water (3 liters / minute).

Peak intensity ratio (C1s / Si2p) by XPS (X-ray photoelectron spectroscopy) of glass plate 1-d was measured. Here, the C1s peak measured the peak of 284.6 eV, the Si2p peak measured the peak of 103.4 eV, and the intensity ratio of C1s / Si2p was calculated | required. As a result, the peak intensity ratio (C1s / Si2p) by XPS of Example 1 was 0.2.

It is preferable that the intensity ratio of C1s / Si2p is 1.5 or less, especially 1.0 or less, and 0.5 or less in practical use. In addition, the larger the intensity ratio of C1s / Si2p, the more C (carbon) remaining on the glass surface.

<Examples 2-5>

In Examples 2-5, the density | concentration of the 0.01 mass% ammonium alginate aqueous solution used by said Example 1 was 0.1 mass% (Example 2), 0.5 mass% (Example 3), 1.0 mass% (Example 4) And 3.0 mass% (Example 5), and obtained the glass plate with a protective film. Moreover, in Example 5, water washing conditions were further changed. Specifically, in Examples 2 to 4, water washing was performed for 30 seconds under 20 ° C of pure water (3 liters / minute) as in Example 1, but in Example 5, under 20 ° C of pure water flowing (3 Liter / min) for 90 seconds.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was Example 2: 0.2, Example 3: 0.1, Example 4: 0.2, and Example 5: 0.2.

Moreover, as a result of measuring the film thickness of the protective film which concerns on Examples 2-5 obtained here, it was 1.5 micrometers, 3.0 micrometers, 5.0 micrometers, and 50 micrometers, respectively.

Comparative Example 1

Instead of the 0.01 mass% ammonium alginate aqueous solution used in Example 1, 0.02 mol / l aqueous solution of sodium tetraborate (using pure water) was used, and all other conditions were the same, and the glass plate with a protective film was obtained.

As a result of measuring the film thickness of the protective film obtained here, all four glass pieces were 0.05 micrometers.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.2.

Comparative Example 2

Only the water washing conditions of the comparative example 1 were changed, and the glass plate with a protective film was obtained. Specifically, in Comparative Example 1, water washing was performed for 30 seconds under 20 ° C of pure water (3 liters / minute). In Comparative Example 2, water washing for 20 seconds under 20 ° C of pure water (3 liters / minute) was performed. It was.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.1.

Comparative Example 3

Instead of the aqueous 0.01 mass% ammonium alginate solution used in Example 1, a polyvinyl alcohol (PVA) aqueous solution (3.0 mass% using pure water) having a polymerization degree of 240 and a saponification degree of 65 mol% was used, and all other conditions were the same. To obtain a glass plate with a protective film.

PVA used here is UMR-10H made from UNICHIKA CHEMICALS, and is the same as Example 1 of patent document 2.

As a result of measuring the film thickness of the protective film obtained here, all four glass pieces were 0.5 micrometer.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. As a result, the presence of scratches on the glass plate surface was not confirmed. Table 1 shows the measurement results.

In addition, the contact angle was 18 degrees (Table 1). This value is a value significantly higher than the contact angle of the surface of the glass plate itself, and means that PVA remains on the glass plate surface.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was 2.0.

In addition, the TOF-SIMS spectrum detects a typical fragment peak of PVA at a mass number of 43 amu (negative ion detection), and C-0 and O = C- attributable to vinyl acetate present in PVA also from the XPS C1s spectrum. The component belonging to 0 was detected and it turned out that the protective film remains. This is considered to be because PVA forms a strong bond with the silanol group which exists in a glass surface, and cannot be removed with water. It is thought that the residue of such a protective film adversely affects a resist or a liquid crystal coating process by a post process, and is not preferable for the glass plate for liquid crystal displays.

<Comparative Example 4>

Instead of the PVA aqueous solution (3.0 mass%) having a polymerization degree of 240 and the saponification degree of 65 mol% used in Comparative Example 3, PVA (5.0 mass%) having a polymerization degree of 240 and a saponification degree of 55 mol% was used. In the same manner, a glass plate with a protective film was obtained.

As a result of measuring the film thickness of the protective film obtained here, four glass pieces were 5.0 micrometers.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. As a result, it was the same result as the comparative example 3. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPSb measured by the method similar to Example 1 was 2.0.

Comparative Example 5

Using the PVA aqueous solution of polymerization degree 240 and saponification degree 55 mol% used by the comparative example 4, all other conditions were the same and the glass plate with a protective film was obtained. However, in order to thicken the film thickness, the number of times of brush application was increased from one to ten times.

As a result of measuring the film thickness of the protective film obtained here, all four glass pieces were 50 micrometers.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. Table 1 shows the measurement results. As a result, the contact angle was a high value of 30 degrees. Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 3.2. That is, it is thought that much PVA remains on the glass substrate surface after water washing.

Comparative Example 6

The water washing for 30 seconds was performed under 20 degreeC pure water (3 liters / minute) flowed in Comparative Example 5, and the water washing for 90 seconds under 20 degreeC pure water flows (3 liters / minute), and all other conditions In the same manner, a glass plate with a protective film was obtained.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate with a protective film were evaluated. Table 1 shows the measurement results. As a result, the contact angle was a high value of 25 degrees. Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was 3.0. Thus, since it is a low value compared with the comparative example 5, although it is decreasing compared with the case of the comparative example 5, compared with Examples 1-5, it is thought that much PVA remains on the glass substrate surface after water washing. .

Comparative Example 7

Without using the ammonium alginate used in Example 1 (that is, not forming a protective film), the others were obtained on the same conditions as Example 1, and the glass plate was obtained.

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate were evaluated. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was 2.0.

<Comparative Example 8>

The glass plate was obtained by making water wash for 30 second under the 20 degreeC pure water flow (3 liters / minute) performed by the comparative example 7, and wash for 90 second under 20 degreeC pure water flow (3 liters / minute).

In the same manner as in Example 1, scratches (A), scratches (B), and contact angles of the glass plate were evaluated. Table 1 shows the measurement results.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was 2.0.

It is considered from these Examples 1-5 and Comparative Examples 1-8 that ammonium alginate is apply | coated to the surface of an alkali free glass plate that the damage and contamination of the alkali free glass plate surface which generate | occur | produce during storage and transportation can be prevented.

Moreover, as shown in Comparative Examples 3-6, even if the alkali free glass plate which apply | coated PVA was washed, it confirmed that PVA remained on the glass plate surface. Patent Document 2 also describes that the protective film was completely removed as a result of observing the glass surface after washing under a microscope in the example. Since this was observation by a microscope, it is thought that some residuals could not be observed. It was confirmed that PVA remained by the advanced measurement by the time-of-flight type secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS).

The alkali free glass plate used for a liquid crystal display etc. cannot accept even the contamination of the grade which cannot be observed with a microscope, and higher surface characteristics are calculated | required.

In addition, the protective film itself was damaged in the films of Examples 1 to 5 coated with ammonium alginate. However, there was no scratch on the glass surface after washing with water. In contrast, Comparative Examples 1 and 2 coated with sodium tetraborate also showed no scratches on the glass surface after washing with water. However, malfunctions occur when the liquid crystal display is manufactured using the glass substrates of Comparative Examples 1 and 2. Thereby, it is estimated that the sodium powder in the coated film malfunctioned.

Moreover, when the film thickness of the protective film of sodium tetraborate was more than 0.2 micrometer, the flaw generate | occur | produced on the glass surface after water washing. This is considered to be because sodium tetraborate causes condensation due to a thermal cycle test and cracks in the coating, so that the glass surface cannot be uniformly covered and the exposed glass surface is scratched. On the other hand, since ammonium alginate has a lower solubility in water than a water-soluble substance composed of water-soluble salts, even if condensation occurs on the surface of the protective film during the process of removing it, it is difficult to dissolve, even when the film thickness is high. Even after being used for a cycle test, it is assumed that the glass surface is uniformly coated and that the glass substrate is not damaged.

In addition, "〃" in a table | surface means that it is the same as the item described above.

<Glass Plate with Functional Thin Film Coated Ammonium Alginate>

<Example 6>

On one main surface of the alkali free glass plate for liquid crystal displays of 0.7 mm thickness used in Example 1, the electrically conductive film (200 nm in thickness) which consists of indium oxide (ITO) was formed by a well-known method. And 4 sheets were cut out at 50 * 50cm in the width | variety similarly to Example 1. Each glass piece was treated with a UV / O ₃ washer for 3 minutes, and then washed with water to dry naturally.

Next, the aqueous solution of ammonium alginate of the same kind and concentration as in Example 1 was applied to the conductive film surface of each glass piece using a spray. And drying similarly to Example 1, the protective film of ammonium alginate was formed in the surface of an electrically conductive film, and the glass plate with a protective film was obtained.

The thickness of the protective film of ammonium alginate obtained here was 1 micrometer in all four glass pieces.

Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.2.

<Example 7>

Instead of the transparent conductive film made of indium oxide (ITO) of Example 6, a heat ray shielding film made of ZnO / Ag / ZnO / Ag / ZnO (film thickness of each layer: 20 nm / 10 nm / 80 nm / 10 nm / 20 nm) was formed. Except having used the glass piece, it processed like Example 6 and obtained the glass plate with a protective film.

Here, the thickness of the protective film of the obtained ammonium alginate was 1.0 micrometer in all four glass pieces.

Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.1.

Comparative Example 9

Instead of the ammonium alginate used in Example 6, 0.05 mol / l sodium tetraborate was used, and all other conditions were the same as Example 6, and the glass plate with a protective film was obtained.

The thickness of the protective film of sodium tetraborate obtained here was 0.5 micrometer in all four glass pieces.

Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2. Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.2.

In addition, although the protective film was completely removed by water washing, scratches were observed in the conductive film.

Comparative Example 10

Instead of the ammonium alginate used in Example 7, 0.05 mol / l sodium tetraborate was used, and all other conditions were the same as in Example 7, to obtain a glass plate with a protective film.

The thickness of the protective film of sodium tetraborate obtained here was 0.5 micrometer in all four glass pieces. Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 0.1.

Comparative Example 11

Instead of the ammonium alginate used in Example 6, a PVA aqueous solution having a polymerization degree of 240 and a saponification degree of 65 mol% similar to that of Comparative Example 3 was used, and all other conditions were the same as in Example 6 to obtain a glass plate with a protective film.

The thickness of the protective film of PVA obtained here was 1.0 micrometer of four glass pieces.

Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Scratches were not found in the conductive film, but the protective film was not completely removed by washing with water, and it was confirmed by XPS analysis and reconfirmed by TOF-SIMS and XPS analysis. Moreover, the peak intensity ratio (Cls / Si2p) by XPS measured by the method similar to Example 1 was 2.0.

This is considered to be because PVA forms a firm bond with In-OH, Sn-OH, or Zn-OH groups present on the surfaces of the ITO film and the ZnO film, and cannot be removed by water. When the residue of such a protective film is patterned etc. by a post process, it is thought that it adversely affects patterning characteristics, and it is unpreferable.

Comparative Example 12

Instead of the ammonium alginate used in Example 7, the PVA aqueous solution of the polymerization degree 240 and the saponification degree 65 mol% similar to the comparative example 3 were used, and all other conditions were performed similarly to Example 7, and the glass plate with a protective film was obtained.

The thickness of the protective film of PVA obtained here was 1.0 micrometer of four glass pieces.

Using this obtained glass plate with a protective film, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Scratches were not observed in the heat ray shielding film, but the protective film was not completely removed by washing with water, and it was confirmed by XPS analysis and TOF-SIMS similarly to Comparative Example 11. Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 2.7.

Comparative Example 13

Without using the ammonium alginate used in Example 6 (without forming a protective film), the others were obtained on the same conditions as Example 6 and the glass plate was obtained.

Using this obtained glass plate, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the method similar to Example 1 was 2.0.

Comparative Example 14

Without using the ammonium alginate used in Example 7 (that is, not forming a protective film), the others were obtained on the same conditions as Example 7, and the glass plate was obtained.

Using this obtained glass plate, the flaw evaluation (A), the flaw evaluation (B), and the contact angle were evaluated by the method similar to Example 1. The measurement results are shown in Table 2.

Moreover, the peak intensity ratio (C1s / Si2p) by XPS measured by the same method as Example 1 was 2.8.

<Example 8>

In Example 6, the glass piece cut out to 50 * 50cm in width and length is cut out to moderate size, and a liquid crystal display is manufactured using this glass plate. This liquid crystal display does not cause malfunctions.

Comparative Example 15

About the comparative example 9, the glass piece cut out to 50 * 50cm in width and height was cut out to moderate size, and a liquid crystal display is manufactured using this glass plate. This liquid crystal display malfunctions.

Example 9

In Example 9, the glass plate with a protective film was obtained using the mixed aqueous solution of 0.0095 mass% ammonium alginate and 0.0005 mass% glycerin instead of using the 0.01 mass% ammonium alginate aqueous solution used in Example 1.

In addition, the alkali powder of this mixed aqueous solution was 1 ppm or less. Moreover, the film thickness of the protective film obtained here was 0.5 micrometer. Moreover, the alkali powder in the protective film was 5000 ppm.

In the same manner as in Example 1, scratches (A), scratches (B), contact angles, and peak intensity ratios (C1s / Si2p) of the glass plate with a protective film were evaluated. Table 3 shows the measurement results.

Comparative Example 16

In the comparative example 16, the glass plate with a protective film was obtained using the mixed aqueous solution of 0.005 mass% ammonium alginate and 0.005 mass% glycerin instead of using the 0.01 mass% ammonium alginate aqueous solution used in Example 1.

In addition, the alkali powder of this mixed aqueous solution was 1 ppm or less. Moreover, the film thickness of the protective film obtained here was 0.5 micrometer. Moreover, the alkali powder in the protective film was 5000 ppm.

In the same manner as in Example 1, scratches (A), scratches (B), contact angles, and peak intensity ratios (C1s / Si2p) of the glass plate with a protective film were evaluated. Table 3 shows the measurement results.

<Example 10>

On one main surface of the alkali free glass plate for liquid crystal displays of 0.7 mm thickness used in Example 1, the electrically conductive film (200 nm in thickness) which consists of indium oxide (ITO) was formed by a well-known method. And 4 sheets were cut out at 50 * 50cm in the width | variety similarly to Example 1. Each glass piece was treated with a UV / O ₃ washer for 3 minutes, and then washed with water to dry naturally.

Next, the mixed aqueous solution of 0.0095 mass% ammonium alginate and 0.0005 mass% glycerin was apply | coated to the surface of the conductive film of each glass piece using a spray. And drying similarly to Example 1, the protective film of ammonium alginate was formed in the surface of an electrically conductive film, and the glass plate with a protective film was obtained.

The thickness of the protective film obtained here was 1 micrometer in all four sheets.

In the same manner as in Example 1, scratches (A), scratches (B), contact angles, and peak intensity ratios (C1s / Si2p) of the glass plate with a protective film were evaluated. Table 3 shows the measurement results.

<Example 11>

Instead of the transparent conductive film made of indium oxide (ITO) of Example 10, a heat ray shielding film made of ZnO / Ag / ZnO / Ag / ZnO (film thickness of each layer: 20 nm / 10 nm / 80 nm / 10 nm / 20 nm) was formed. Except having used the glass piece, it processed like Example 10 and obtained the glass plate with a protective film.

Here, the thickness of the protective film of the obtained ammonium alginate was 1.0 micrometer in all four glass pieces.

In the same manner as in Example 1, scratches (A), scratches (B), contact angles, and peak intensity ratios (C1s / Si2p) of the glass plate with a protective film were evaluated. Table 3 shows the measurement results.

Comparative Example 17

Instead of the mixed aqueous solution used in Example 10, a mixed aqueous solution of 0.005 mass% ammonium alginate and 0.005 mass% glycerin was used, and all others were obtained under the same conditions as in Example 10 to obtain a glass plate.

The peak intensity ratio (C1s / Si2p) by the flaw (A), the flaw (B), and the contact angle XPS of a glass plate was evaluated by the method similar to Example 1. Table 3 shows the measurement results.

Comparative Example 18

Instead of the mixed aqueous solution used in Example 11, a mixed aqueous solution of 0.005 mass% ammonium alginate and 0.005 mass% glycerin was used, and all others were obtained under the same conditions as in Example 11 to obtain a glass plate.

In the same manner as in Example 1, scratches (A), scratches (B), contact angles, and peak intensity ratios (C1s / Si2p) of the glass plate were evaluated. Table 3 shows the measurement results.

Since the glass with a protective film of this invention can be washed with water and can prevent a scratch, it is useful for a liquid crystal display etc.

In addition, all the content of the JP Patent application 2005-221444, a claim, drawing, and the abstract for which it applied on July 29, 2005 is referred here, and it introduces as an indication of the specification of this invention.

Claims (21)

The protective agent for alkali free glass plates containing water-soluble alkali free organic acid salt, and being alkali free. The method of claim 1, The protecting agent for alkali free glass plates whose water-soluble alkali free organic acid salt is the alkali free carboxylate of saccharide. The method of claim 2, The alkali free carboxylate of a saccharide is the alkali free glass protective agent which is an alkali free carboxylate of a polysaccharide. The method of claim 3, wherein The protective agent for alkali free glass plates in which the alkali free carboxylate of polysaccharide is ammonium alginate. The method according to any one of claims 1 to 4, The protective agent for alkali free glass plates whose viscosity of a protective agent is 350-500 mPa * s in 20 degreeC and pH6-8. The method according to any one of claims 1 to 5, Protective agent for alkali free glass plates in which a protective agent is not gelatinized. The method according to any one of claims 1 to 6, The protective agent for alkali free glass plates whose content rate of the water-soluble alkali free organic acid salt in a protective agent is 0.005-90 mass%. The method according to any one of claims 1 to 7, The protective agent for alkali free glass plates containing a water-soluble film | membrane structural component in a protective agent, and the ratio of water-soluble alkali-free organic acid salt is 50 mass% or more with respect to the total amount of water-soluble alkali-free organic acid salt and a water-soluble film structural component. The method according to any one of claims 1 to 8, The protective agent for alkali free glass plates whose content of the alkali component in a protective agent is 50 ppm or less. The glass plate with a protective film formed by apply | coating the protective agent for alkali free glass plates of any one of Claims 1-9 to an alkali free glass plate. The glass plate with a protective film containing water-soluble alkali free organic acid salt, and having a protective film which is alkali free on at least one main surface of an alkali free glass plate. The method of claim 11, The glass plate with a protective film whose water-soluble alkali free organic acid salt is the alkali free carboxylate of saccharide. The method of claim 12, The glass plate with a protective film whose alkali free carboxylate of a saccharide is the alkali free carboxylate of a polysaccharide. The method of claim 13, The glass plate with a protective film whose alkali-free carboxylate of polysaccharide is ammonium alginate. The method according to any one of claims 11 to 14, The glass plate with a protective film containing a water-soluble film structural component in a protective film, and the ratio of water-soluble alkali-free organic acid salt is 50 mass% or more with respect to the total amount of a water-soluble alkali free organic acid salt and a water-soluble film structural component. The method according to any one of claims 11 to 15, The glass plate with a protective film whose content of the alkali component in a protective film is 30000 ppm or less. The method according to any one of claims 11 to 16, The glass plate with a protective film whose magnitude of an alkali free glass substrate is 1500 mm x 1800 mm or more. The method according to any one of claims 11 to 17, The glass plate with a protective film whose thickness of a protective film is 0.2-100 micrometers. The method according to any one of claims 11 to 18, The glass plate with a protective film which has a functional thin film further between the main surface of the said alkali free glass plate and the said protective film. The alkali free glass plate which wash | cleaned the glass plate with a protective film in any one of Claims 11-19, and removed at least one part of the said protective film from the main surface of the said alkali free glass plate or the said functional thin film phase. The glass laminated body which laminated | stacked at least 2 or more sheets of the glass plate with a protective film in any one of Claims 11-19.

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