CN114845966A - Method for manufacturing glass plate - Google Patents

Abstract

A method for manufacturing a glass plate, comprising a storage step for storing the glass plate in contact with a resin sheet and a cleaning step for cleaning the glass plate after the storage step, wherein the cleaning step (S2) of the method for manufacturing a glass plate comprises a first cleaning step (S21) for supplying a first cleaning liquid (CS1) to the glass plate (G) to clean the glass plate (G), and a second cleaning step (S23) for supplying a second cleaning liquid (CS2) to the glass plate (G) after the first cleaning step (S21) to clean the glass plate (G). The first cleaning liquid (CS1) is an acidic cleaning liquid, and the second cleaning liquid (CS2) is an alkaline cleaning liquid.

Description

Manufacturing method of glass plate

technical field

The present invention relates to a method of manufacturing a glass sheet.

Background technique

In recent years, high definition of panel displays such as liquid crystal displays and organic EL displays has been advanced. Along with this, a dense electrical circuit is formed in the glass plate used as a substrate for a display through the manufacturing process of the display. Therefore, the high cleanability which does not adhere to dust and dirt is required to such a glass plate.

The manufacturing process of a glass plate includes, for example, an unbundling process of taking out a glass original plate stored on a tray, a cutting process of cutting out a glass plate of a predetermined size from the taken-out glass original plate, an end surface processing process of subjecting the glass plate to end surface processing, and washing. The cleaning process of the glass plate which has been end-faced. As a method of washing a glass plate, the method of washing|cleaning the glass plate conveyed in a predetermined direction with washing tools, such as a washing plate and a washing brush (roller brush), is mentioned (for example, refer patent document 1).

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2017-14060

SUMMARY OF THE INVENTION

The problem to be solved by the invention

The glass original plate supplied to the manufacturing process of the said glass plate is mounted and stored on a tray, and some glass original plate may be laminated|stacked via a resin sheet on a tray.

In this case, when stored on a tray for a long period of time, calcium fouling and fouling containing organic substances may occur. Moreover, these stains adhere firmly to the glass original plate, and it may be difficult to remove these stains from the glass plate in the cleaning process.

Therefore, the technical subject of this invention is to improve the cleaning power in the cleaning process of a glass plate.

solutions to problems

The present invention is a method for producing a glass plate for solving the above-mentioned problems, comprising a storage step of storing a glass plate in contact with a resin sheet, and a washing step of washing the glass plate after the storage step, the The manufacturing method of a glass plate is characterized in that the cleaning step includes a first cleaning step of cleaning the glass plate by supplying a first cleaning solution to the glass plate, and supplying the glass plate after the first cleaning step. In the second cleaning process of cleaning the glass plate with a second cleaning solution, the first cleaning solution is an acidic cleaning solution, and the second cleaning solution is an alkaline cleaning solution.

As a result of intensive research by the present inventors, it was confirmed that when the resin sheet is kept in contact with the glass plate for a long period of time, when the dirt transferred from the resin sheet to the surface of the glass plate contains calcium (hereinafter, referred to as "Calcium scale"), which is more difficult to remove from glass sheets by washing than other scales.

The inventors of the present invention have found that after the first cleaning step in which the first cleaning solution is an acidic cleaning solution, and the second cleaning process in which the second cleaning solution is an alkaline cleaning solution is performed, the calcium contamination can be effectively removed. And dirt containing organics is removed from the glass plate.

Alternatively, the acidic cleaning solution may contain a hydroxy acid. As a hydroxy acid (oxyacid), glycolic acid, lactic acid, tartaric acid, citric acid, malic acid, salicylic acid, etc. are mentioned, for example. Hydroxy acid is a carboxylic acid having both a hydroxyl group and has high water solubility. In addition, the hydroxy acid reacts with calcium ions (Ca2 ⁺ ) of calcium fouling on the surface of the glass plate by a chelating effect due to the carboxyl group contained in the molecule, and takes calcium ions into one molecule or a plurality of molecules and stabilizes them Therefore, it is effective for the removal of the calcium component adhering to the surface of a glass plate.

The alkaline cleaning solution may contain a hydroxide salt, for example, may contain at least one of sodium hydroxide and potassium hydroxide.

In the first cleaning step, the glass plate may be cleaned by bringing a cleaning tool into contact with the glass plate. Thereby, the 1st cleaning process can be performed efficiently.

In the second cleaning step, the glass plate may be cleaned by bringing a cleaning tool into contact with the glass plate. Thereby, the 2nd cleaning process can be performed efficiently.

The present method may include a liquid removing step of supplying a removing liquid to the glass plate after the first cleaning step and before the second cleaning step, thereby removing the first cleaning step adhering to the glass plate. A cleaning solution is removed, and the removal solution is warm water. This liquid removal step removes the first cleaning liquid adhering to the glass plate after the first cleaning step, and can perform cleaning of the glass plate using the second cleaning liquid more efficiently in the subsequent second cleaning step.

The method may include a rinsing step of supplying a rinsing liquid to the glass plate after the second cleaning step to remove the second cleaning liquid adhering to the glass plate, and the rinsing liquid may be Contains alkaline electrolyzed water. By covering the surface of the glass plate with anions in the rinsing process, the particulate matter dispersed in the rinsing solution can be prevented from re-adhering to the surface of the glass plate, and the cleanliness of the surface of the glass plate after the rinsing process can be improved.

Invention effect

According to this invention, the cleaning power in the cleaning process of a glass plate can be improved.

Description of drawings

1 : is sectional drawing which shows the manufacturing method of the glass plate of 1st Embodiment of this invention.

2 is a cross-sectional view showing a configuration of a cleaning machine in a first cleaning unit and a second cleaning unit.

FIG. 3 is a flowchart showing a cleaning process.

It is sectional drawing which shows the manufacturing method of the glass plate of 2nd Embodiment of this invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1-3 shows 1st Embodiment of the manufacturing method of the glass plate of this invention.

As shown in FIG. 1, this method includes the storage process S1 which stores the glass plate G, and the cleaning process S2 which washes the glass plate G. The unbundling process, the cutting process, and the end surface processing process described above may be further included between the storage process S1 and the cleaning process S2. The inspection process of the glass plate G and the packing process of loading the glass plate G on the tray may be further included as a post process of the washing process S2.

In storage process S1, the glass plate G is managed in the state of the package body PB. The package body PB is configured by mounting a plurality of glass plates G on the tray P. As shown in FIG. In the storage process S1 of this embodiment, the glass plate G is stored in a horizontal posture, but the glass plate G may be stored in an inclined posture.

The glass plate G is constituted by, for example, cutting a vertically long glass ribbon formed by an overflow down-draw method. The overflow down-draw method is a method in which molten glass flows into an overflow groove provided on the upper part of a formed body having a substantially wedge-shaped cross section, and the molten glass overflowing from both sides of the overflow groove is directed along both sides of the formed body. While the wall portion flows down, the glass ribbon is continuously formed by fusion and integration at the lower end portion of the molded body. The glass plate G is not limited to the overflow down-draw method, and can be produced by the float method and other various forming methods.

Although the glass plate G is comprised in a rectangular shape, it is not limited to this shape. The glass plate G includes a first main surface Ga and a second main surface Gb. In the present embodiment, the first main surface Ga is the guaranteed surface, and the second main surface Gb is the non-guaranteed surface. Here, the "guarantee surface" means the surface on the side to which a film-forming process such as a transparent conductive film is applied during the manufacturing process of the display, for example.

As the glass plate G, for example, silicate glass or silica glass is used, and it is preferably composed of borosilicate glass, soda lime glass, aluminosilicate glass, chemically strengthened glass, or alkali-free glass. Here, the alkali-free glass refers to a glass that does not substantially contain an alkali component (alkali metal oxide), and specifically refers to a glass whose weight ratio of the alkali component is 3000 ppm or less. The weight ratio of the alkali component in the present invention is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

On each glass plate G, the resin sheet RS is stacked. This resin sheet RS prevents the glass plates G from contacting each other in the state of the package body PB.

The resin sheet RS is composed of a rectangular sheet having a larger surface area than the glass plate G. The resin sheet RS is composed of, for example, a foamed resin sheet using a resin containing polyethylene as a main component, a resin protective film, and the like. The resin sheet RS can contain an antistatic agent such as a polymer type antistatic agent, or a surfactant such as an anionic surfactant and a nonionic surfactant.

In the storage step S1, the package body PB is stored, for example, for several days to one year. The longer the storage period is, the more contamination of the glass plate G increases, and the effect of improving the cleaning power of the present invention is more remarkable. Therefore, the storage period is preferably two months or more, and more preferably four months or more. The package body PB that has passed through the storage process S1 is carried out from the storage space SS.

The glass plate G taken out from the packing body PB is supplied to the washing|cleaning process S2. In this case, the resin sheet RS is peeled off from the glass plate G. In the cleaning step S2, the glass plate G is cleaned by the cleaning apparatus 1 shown in FIG. 1 .

The cleaning apparatus 1 mainly includes a first cleaning unit 2 that cleans the glass plate G while supplying the first cleaning solution CS1 to the glass plate G, and a liquid removing unit 3 that removes the first cleaning solution CS1 adhering to the glass plate G Removal; the second cleaning part 4, which cleans the glass plate G while supplying the second cleaning liquid CS2 to the glass plate G; The second cleaning liquid CS2 of G is removed; and the drying part 6 . Moreover, the washing|cleaning apparatus 1 is equipped with the conveyance apparatus 7 which conveys the glass plate G along the predetermined conveyance direction X.

The 1st cleaning part 2 is provided with the upper side cleaning machine 2a which cleans the 1st main surface Ga of the glass plate G, and the lower side cleaning machine 2b which cleans the 2nd main surface Gb of the glass plate G.

The upper cleaning machine 2a includes an upper cleaning tool 8a in contact with the first main surface Ga, and a main body portion 9a that supports the upper cleaning tool 8a. The lower cleaning machine 2b includes a lower cleaning tool 8b in contact with the second main surface Gb, and a main body portion 9b that supports the lower cleaning tool 8b. The upper side washer 2a and the lower side washer 2b are of the same type.

Hereinafter, about the structure of each washing machine 2a, 2b, the upper side washing machine 2a shown in FIG. 2 is demonstrated as an example. The upper cleaning tool 8a is configured in a disk shape, but is not limited to this shape. The upper-side cleaning tool 8 a includes a cleaning member 10 that is in contact with the first main surface Ga of the glass plate G, and a shaft portion 11 that supports the cleaning member 10 .

The cleaning member 10 is formed into a disk shape (disc shape), for example, from a foamed resin molded body, a foamed rubber molded body (foamed sponge), or a felt-shaped fiber molded body (felt sponge). Not limited to this structure, the cleaning member 10 may be constituted by a brush.

The cleaning member 10 has the supply hole 12 which supplies the 1st cleaning liquid CS1 to the glass plate G. The shaft portion 11 is configured in a tubular shape, and can allow the first cleaning liquid CS1 to pass therethrough. The shaft portion 11 communicates with the supply hole 12 of the cleaning member 10 .

The main body portion 9a includes a storage tank 13 for storing the first cleaning liquid CS1, a bearing portion 14 for rotatably supporting the shaft portion 11 of the first cleaning tool, and a drive portion (not shown) for rotating the shaft portion 11 .

The storage tank 13 stores the acidic cleaning liquid as the first cleaning liquid CS1. The acidic cleaning solution is composed of, for example, an aqueous solution containing a hydroxy acid. As a hydroxy acid, glycolic acid, lactic acid, tartaric acid, citric acid, malic acid, salicylic acid, etc. are mentioned, for example. Hydroxy acid is a carboxylic acid having both a hydroxyl group and has high water solubility. In addition, the hydroxy acid reacts with the calcium ions (Ca2+) of calcium fouling on the surface of the glass plate G (main surfaces Ga, Gb) by the chelating effect due to the carboxyl group contained in the molecule, and reacts with calcium ions (Ca2+) in one molecule or a plurality of molecules. Since calcium ion is taken in and stabilized, it is effective for the removal of the calcium component adhering to each main surface Ga, Gb of the glass plate G. For example, when glycolic acid is used as the acidic cleaning solution, the concentration thereof is preferably 1.5 to 10%, but it is not limited to this range. It should be noted that the acidic cleaning solution may contain one or more hydroxy acids.

Moreover, the 1st washing|cleaning liquid CS1 may contain the surfactant for washing|cleaning and removing the dirt containing the organic substance on the glass plate G. The surfactant can be selected from the group consisting of anionic surfactants typified by sodium alkylbenzenesulfonate and the like, and nonionic surfactants typified by polyoxyethylene alkyl ethers and the like. The surfactant is effective for taking in and removing organic-based contaminants from the contaminants transferred from the resin sheet RS to the main surfaces Ga and Gb of the glass plate G from the main surfaces Ga and Gb of the glass plate G.

The acidic cleaning solution may further contain a chelating adjuvant that preferentially supplements calcium ions in order to prevent readhesion of calcium ions (Ca2 ⁺ ) freed in the cleaning solution to the main surfaces Ga and Gb of the glass plate G. As the added chelating adjuvant, sodium tripolyphosphate, EDTA (ethylenediaminetetraacetic acid), NTA (nitrilotriacetic acid), sodium citrate, various organic polymer chelating adjuvants can also be used, for example An inorganic substance or the like that selectively adsorbs calcium ions such as zeolite is used.

The storage tank 13 may include a heater that heats the first cleaning liquid CS1. The temperature of the first cleaning liquid CS1 in this case is preferably 40 to 50° C., but is not limited to this range.

The 1st cleaning part 2 can perform wiping cleaning of the glass plate G by rotating the shaft part 11 by a drive part in the state which made each cleaning tool 8a, 8b contact with each main surface Ga, Gb of the glass plate G.

The liquid removing part 3 is for removing the 1st cleaning liquid CS1 adhering to the glass plate G which passed the 1st cleaning part 2. The liquid removal unit 3 includes an upper air knife 3a and a lower air knife 3b. The liquid removing part 3 can remove the 1st cleaning liquid CS1 from the glass plate G by blowing the air of each air knife 3a, 3b to each main surface Ga, Gb of the glass plate G.

The 2nd washing|cleaning part 4 is equipped with the upper side washing machine 4a and the lower side washing machine 4b which can perform wiping washing with respect to the glass plate G. The upper cleaning machine 4a includes an upper cleaning tool 15a and a main body 16a that supports the upper cleaning tool 15a. The lower cleaning machine 4b includes a lower cleaning tool 15b and a main body 16b that supports the lower cleaning tool 15b. The upper washer 4a and the lower washer 4b of the second cleaning unit 4 have the same configuration as the upper washer 2a and the lower washer 2b of the first cleaning unit 2 .

However, the second cleaning unit 4 is different from the first cleaning unit 2 in that an alkaline cleaning liquid is used as the second cleaning liquid CS2. The alkaline cleaning solution contains a hydroxide salt, and is composed of, for example, an aqueous solution containing at least one of sodium hydroxide and potassium hydroxide. The total of the concentration of sodium hydroxide and the concentration of potassium hydroxide in the alkaline cleaning solution is preferably 0.5 to 10%, and more preferably 1.5 to 10%. The second cleaning liquid CS2 may contain a surfactant and a chelating agent. In addition, the temperature of the second cleaning liquid CS2 is preferably 40 to 50° C., but is not limited to this range.

The alkaline cleaning solution is not limited to hydroxide salts, and may contain carbonates. As the carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, sodium bicarbonate (sodium bicarbonate), or the like can be used. In addition, not limited to the above, the alkaline cleaning solution may contain an alkaline builder auxiliary such as a silicate.

With the above-described alkaline cleaning solution, other contaminants including organic substances can be removed from the glass plate G more efficiently. In addition, each main surface Ga and Gb of the glass plate G is made alkaline to maintain a negative charge, so that the adsorption and remaining on each main surface Ga of the glass plate G can be achieved after using the first cleaning liquid CS1 (acidic cleaning agent). , Gb of highly polar surfactant components are particularly effectively removed.

The alkaline cleaning solution may contain a surfactant component for effectively removing the organic-containing dirt on the glass plate G and the residue of the above-mentioned acidic cleaning agent. The surfactant can be selected from the group consisting of anionic surfactants typified by sodium alkylbenzenesulfonate and the like, and nonionic surfactants typified by polyoxyethylene alkyl ethers and the like. The surfactant is effective for taking in and removing the residues of the main body of the organic material on the main surfaces Ga and Gb of the glass plate G and removing them from the main surfaces Ga and Gb of the glass plate G.

More preferably, in order to prevent the calcium ions removed from the glass plate G and freed in the alkaline cleaning solution from adhering to the main surfaces Ga and Gb of the glass plate G again, the alkaline cleaning solution may contain the first cleaning solution. The same chelating aid for CS1.

The rinse part 5 is for removing the 2nd cleaning liquid CS2 adhering to the glass plate G which passed the 2nd cleaning part 4. The flushing portion 5 includes an upper flushing liquid supply portion 5a and a lower flushing liquid supply portion 5b. The upper side rinse liquid supply part 5a supplies rinse liquid to the 1st main surface Ga of the glass plate G. The lower side rinse liquid supply part 5b supplies rinse liquid to the 2nd main surface Gb of the glass plate G.

As the rinsing liquid, for example, pure water is used, but it is not limited to this. For example, as the rinsing liquid, pure water containing alkaline electrolyzed water of about pH=11 formed from a small-concentration potassium carbonate aqueous solution by electrolysis can also be used. As a result, the main surfaces Ga and Gb of the glass plate G are negatively charged (covered with anions), and calcium ions, organic substances, particles, etc. dispersed in the liquid are negatively charged and have a repelling effect, thereby preventing foreign matter from entering the cleaned glass. The re-adhesion of the main surfaces Ga and Gb of the plate G is particularly effective in reducing fine particles that are not visible in the external inspection. When using the pure water containing alkaline electrolyzed water, the pH of the alkaline electrolyzed water containing pure water is set to 9-12, for example.

The rinse part 5 is provided with a jet nozzle, and can remove the second cleaning liquid CS from the glass plate G by jetting a high-pressure rinse liquid for cleaning. The rinse part 5 may remove the 2nd cleaning liquid CS2 from the glass plate G by injecting the rinse liquid obtained by mixing air into pure water by a mixing nozzle. Moreover, the rinsing part 5 may remove the 2nd cleaning liquid CS from the glass plate G using a cleaning tool.

The drying unit 6 removes the rinse liquid adhering to the glass plate G that has passed through the rinse unit 5 . The drying section 6 includes an upper air knife 6a and a lower air knife 6b. The upper air knife 6a blows air to the 1st main surface Ga of the glass plate G which has passed the rinse part 5. The lower side air knife 6b blows air to the 2nd main surface Gb of the glass plate G.

The conveyance apparatus 7 conveys the glass plate G from the 1st washing|cleaning part 2 to the drying part 6. The conveying device 7 is composed of, for example, a roller conveyor, but is not limited to this configuration. The conveyance apparatus 7 is provided with the some conveyance roller 7a arrange|positioned at predetermined intervals. Each conveyance roller 7a is rotationally driven, contacting the 2nd main surface Gb of the glass plate G, and conveys this glass plate G along the conveyance direction X.

As shown in FIG. 3 , the cleaning step S2 includes a first cleaning step S21 , a liquid removing step S22 , a second cleaning step S23 , a rinsing step S24 , and a drying step S25 .

In the 1st cleaning process S21, in the 1st cleaning part 2, the upper side cleaning tool 8a and the lower side cleaning tool 8b of the 1st cleaning part 2 are made to convey the glass plate G along the conveyance direction X by the conveyance device 7 It is in contact with the first main surface Ga and the second main surface Gb of the glass plate G. Thereby, the glass plate G is clamped by each cleaning tool 8a, 8b. Each cleaning tool 8a, 8b rotates the cleaning member 10, supplying the acidic cleaning liquid as the 1st cleaning liquid CS1 to each main surface Ga, Gb of the glass plate G. Thereby, the 1st main surface Ga of the glass plate G and the 2nd main surface Gb are cleaned simultaneously.

In the liquid removal step S22, air is blown from the respective air knives 3a and 3b of the liquid removal part 3 to the glass plate G that has passed through the first cleaning part 2, so that the first main surface Ga and the second glass plate G adhered to the glass plate G are blown with air. The first cleaning liquid CS1 on the two main surfaces Gb is removed.

In the 2nd cleaning process S23, in the 2nd cleaning part 4, while conveying the glass plate G along the conveyance direction X, the upper side cleaning tool 15a and the lower side cleaning tool 15b of the 2nd cleaning part 4 and the glass plate G are made to The first main surface Ga and the second main surface Gb are in contact. Each cleaning tool 15a, 15b rotates the cleaning member 10, supplying the alkaline cleaning liquid as the 2nd cleaning liquid CS2 to each main surface Ga, Gb of the glass plate G. Thereby, the 1st main surface Ga of the glass plate G and the 2nd main surface Gb are cleaned simultaneously.

In the rinsing step S24 , the rinsing liquid is supplied from the respective rinse liquid supply parts 5 a and 5 b of the rinse part 5 to the glass plate G that has passed through the second cleaning part 4 . Thereby, the 2nd cleaning liquid CS2 adhering to the 1st main surface Ga of the glass plate G and the 2nd main surface Gb can be removed.

In drying process S25, air is blown from each air knife 6a, 6b of the drying part 6 with respect to the glass plate G which has passed through the rinsing part 5. In this case, it is desirable to spray high-pressure air toward the glass plate G from the air knives 6a, 6b, for example. Thereby, the rinse liquid adhering to the glass plate G can be removed.

According to the manufacturing method of the glass plate G of this embodiment, the calcium stain|pollution|contamination transcribe|transferred from the resin sheet RS to the glass plate G in the storage process S1 can be removed efficiently by 1st washing|cleaning process S21. Moreover, in the 2nd washing|cleaning process S23, the stain|pollution|contamination containing an organic substance can be removed efficiently. Thereby, the cleaning power in the cleaning process S2 of the glass plate G can be improved. Here, it is presumed that the calcium fouling is due to the trace amount of calcium contained in the moisture in the atmosphere during the process of absorbing the moisture in the atmosphere by the additives (for example, polyethylene glycol and a copolymer of polyethylene glycol and polypropylene) contained in the resin sheet RS. It is produced by precipitation, concentration and adhesion to glass. In addition, it is presumed that the fouling containing organic substances is caused by the exudation of various additives (eg, sparse aqueous substances) contained in the resin sheet RS.

4 : has shown 2nd Embodiment of the manufacturing method of the glass plate of this invention. In the present embodiment, the configuration of the liquid removal step S22 is different from that of the first embodiment. In the first embodiment, the liquid removal unit 3 of the cleaning apparatus 1 is constituted by an air knife, but the liquid removal unit 3 of the present embodiment includes a shower for supplying a removal liquid for removing the first cleaning liquid CS1 adhering to the glass plate G Composition of cleaning device.

The liquid removing unit 3 includes an upper removing liquid supplying part 17a and a lower removing liquid supplying part 17b. The upper side removal liquid supply part 17a supplies a removal liquid to the 1st main surface Ga of the glass plate G. The lower side removal liquid supply part 17b supplies a removal liquid to the 2nd main surface Gb of the glass plate G.

The removal liquid supplied to the glass plate G consists of pure water, for example. The removal liquid is preferably supplied to the glass plate G in the state of heated warm water. The temperature of the removal liquid is preferably 40 to 60° C., for example, but is not limited to this range.

The removal liquid may also contain alkaline electrolyzed water. By using alkaline electrolyzed water in the removal liquid, each main surface Ga, Gb of the glass plate G is covered with anions, and the particulate matter removed from the glass plate G and dispersed in the removal liquid is prevented from reattaching to the glass plate G's main surfaces Ga, Gb. Thereby, the cleanliness of each main surface Ga, Gb of the glass plate G after 1st washing|cleaning process S21 can be improved.

The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. In the present invention, various modifications can be made without departing from the gist of the present invention.

In the above-mentioned embodiment, although the manufacturing method of the glass plate G including the liquid removal process S22 between the 1st cleaning process S21 and the 2nd cleaning process S23 was illustrated, this invention is not limited to this structure. In the present invention, for example, the liquid removal step S22 may be omitted.

In the above-described embodiment, a disk-shaped (disk-shaped) cleaning tool is exemplified as the cleaning tools 8a, 8b, 15a, and 15b, but the present invention is not limited to this configuration. The cleaning tool may be constituted by a cleaning roller or other cleaning tools.

The present invention may include a liquid removal step of removing the second cleaning liquid CS2 (alkaline cleaning liquid) adhering to the glass plate G by the second cleaning step S23 between the second cleaning step S23 and the rinsing step S24.

Example

Hereinafter, although the Example of this invention is demonstrated, this invention is not limited to this Example. The present inventors conducted a test for confirming the quality of the glass plate produced by the present invention. The test was performed by two methods, the first method and the second method, as described in detail below.

In the test based on the first method, a clean, dried, rectangular-shaped test soda glass plate and resin sheet were used. The size of the glass plate was 100 mm x 100 mm, and the thickness was 0.7 mm. The size of the resin sheet was 150 mm×150 mm. After the resin sheet was kept in contact with the glass plate for three months, the resin sheet was removed from the glass plate, and a test piece of the glass plate in which lime scale and organic-containing scale were formed on the surface was produced (Example 1 to 5. Comparative Example 1).

In the test, after the glass plates of Examples 1 to 5 were washed with an acidic washing liquid (first washing liquid), the glass plates were washed with an alkaline washing liquid (second washing liquid). In this case, the glass plates of each of Examples 1 to 5 were cleaned by changing the concentration of the acidic cleaning solution and the concentration of the alkaline cleaning solution. Moreover, the glass plate of the comparative example 1 was wash|cleaned with the alkaline washing|cleaning liquid (1st washing|cleaning liquid), and the glass plate of the comparative example 1 was wash|cleaned with the acidic washing|cleaning liquid (2nd washing|cleaning liquid).

Specifically, the above-mentioned cleaning liquid of a predetermined concentration was blown with a shower, and a sponge made of polyvinyl alcohol (PVA) was impregnated with the cleaning liquid to wipe the glass plate for 30 seconds, then manually rinsed with pure water and dried with air. Dry.

The present inventors evaluated the cleaning results with respect to the glass plates of Examples 1 to 5 and Comparative Example 1. The cleaning results were evaluated by the following inspection (visual inspection): the surface of the glass plate was visually confirmed by the reflection and transmission of light with respect to the surface of the glass plate at the time of illumination with an illuminance of 1500 lux using a fluorescent lamp. The presence or absence of dirt on it, etc. In addition, the evaluation of the cleaning result was performed by visual inspection by the reflection of light with respect to the surface of the glass plate at the time of illumination with the illuminance of 10000 lux using higher-intensity halogen illumination. The evaluation results were performed on three levels of ○ (good), Δ (normal), and × (impossible).

The evaluation of ○ (good) in Table 1 indicates that, in the visual inspection, under the conditions that the illuminance of the fluorescent lamp is 1500 lux and the illuminance of the halogen illumination is 10000 lux, no spot-shaped and linear-shaped surface foreign matter was observed, and the A clean and transparent glass plate with translucent spots caused by residual lotion.

The evaluation of △ (normal) in Table 1 indicates that no foreign matter on the surface was observed under the condition of the illumination intensity of fluorescent lamp illumination at 1500 lux, but microscopic foreign matter remained and was observed by visual inspection under the condition of illumination intensity of halogen illumination at 10,000 lux. It is considered that it is a translucent spot that oozes out a foreign matter or a film-like residue of a lotion component.

On the other hand, the evaluation of x (impossible) in Table 1 was determined when residual foreign matter and translucent spots were observed by visual inspection using a fluorescent lamp with an illuminance of 1500 lux.

The test results are shown in Table 1. In addition, the density|concentration of an acidic washing|cleaning liquid shows the density|concentration (mass %) of glycolic acid, and the density|concentration of an alkaline washing|cleaning liquid shows the total concentration (mass %) of sodium hydroxide and potassium hydroxide. In the alkaline cleaning solution, the concentrations (mass %) of sodium hydroxide and potassium hydroxide were the same.

[Table 1]

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Category of the first cleaning solution Acidic Acidic Acidic Acidic Acidic Alkaline Concentration of the first cleaning solution (%) 5 2 2 5 2 5 Type of second cleaning fluid Alkaline Alkaline Alkaline Alkaline Alkaline Acidic Concentration of the second cleaning solution (%) 5 2 1 2 5 5 Fluorescent lamp inspection No foreign matter No foreign matter No foreign matter No foreign matter No foreign matter foreign body halogen lamp inspection No foreign matter No foreign matter There are tiny foreign bodies residual white spots No foreign matter foreign body cleaning results ○ ○ △ △ ○ ×

As shown in Table 1, with respect to Examples 1 to 5, the cleaning results were judged to be good and normal. Among them, in Examples 3 and 4, no contamination was confirmed in the visual inspection of the fluorescent lamp, but some microscopic foreign matters considered to be insufficient cleaning were observed in the visual inspection using the strong illuminance of the halogen lamp, which was considered to be White and opaque thin spots caused by residual acid lotion or residual film-like foreign matter.

On the other hand, about the comparative example 1, it was judged that the stain|pollution|contamination containing an organic substance could not fully be removed from a glass plate, and it was a cleaning failure.

Here, on the surface of the glass plate, there are many cases where calcium dirt adheres to the surface of the glass plate after the dirt including the organic matter accompanying the oozing is observed. Therefore, a part or all of the surface of the dirt including organic matter is often covered with calcium dirt. Therefore, when cleaning with an acidic cleaning liquid (second cleaning liquid) after cleaning with an alkaline cleaning liquid (first cleaning liquid) as in the comparative example, there is a possibility that organic substances are included in the cleaning with the alkaline cleaning liquid. The exposed part of the surface in the dirt is removed, and the calcium dirt tends to be removed by cleaning with an acidic cleaning solution. As a result, it is presumed that there is a tendency for the non-exposed part of the surface to remain in the dirt containing organic matter, and the dirt containing organic matter cannot be sufficiently removed from the glass plate. From the test results, it was confirmed that the cleaning power was improved by cleaning the glass plate with an alkaline cleaning solution after cleaning the glass plate with an acidic cleaning solution.

In the test of the second method, a rectangular glass plate and a polyethylene foamed resin sheet cleaned and dried by a predetermined method were used. The size of the glass plate was 370 mm x 470 mm, and the thickness was 0.5 mm. This glass plate is an alkali-free borosilicate glass plate for liquid crystal displays (material: OA-11 manufactured by Nippon Electric Glass Co., Ltd.). The size of the resin sheet was 400 mm×500 mm, and the thickness was 0.085 mm.

A glass laminate was formed by stacking a polyethylene foam resin sheet and a glass plate. The glass laminate is a set of a combination of one glass plate and one resin sheet, and a plurality of sets of glass laminates are stacked in a horizontal posture. The plurality of sets of glass laminates are glass laminates reproduced in the assumption of a storage state mounted on a conveyance tray.

This glass laminate was put into a constant temperature and humidity tester, and an accelerated environment test in which the temperature and humidity in the tester were changed was implemented. Hereinafter, the details of the accelerated environmental test will be described.

In this test, the 1st process and the 2nd process which differ in temperature and humidity were implemented repeatedly. Specifically, the combination of the first step and the second step was regarded as one cycle, and the cycle was repeated 180 times.

In the first step, the inside of the testing machine is set to high temperature and high humidity. The preset temperature in the testing machine in the first step was 50° C., and the preset humidity was 70%. In the second step, the inside of the testing machine was set to normal temperature and normal humidity. The preset temperature in the testing machine in the second step was 25° C., and the preset humidity was 50%.

The cycle of the first step and the second step is set as follows. First, the temperature and humidity of the first step are maintained for 1 hour. After that, the temperature and humidity in the testing machine were lowered to the conditions of the second step over 1 hour. Then, the temperature and humidity of the second step were maintained for 1 hour. After that, it took 1 hour to raise the temperature and humidity in the testing machine to the conditions of the first step. The above-mentioned maintenance, fall and rise of temperature and humidity is a cycle. This one cycle reproduces, in a short time, changes in the temperature and humidity of the surrounding environment when the glass laminate is stored for one day. In this test, the state in which the glass laminate was stored for 180 days was assumed to be reproduced by repetition of 180 cycles.

By the accelerated environmental test as described above, the components of the resin sheet were transferred to the glass plate to contaminate the glass plate. Then, the resin sheet was removed from the glass plate, and the test piece of the glass plate (Examples 6-10, the comparative example 2) in which the lime scale and the scale containing an organic substance were formed on the surface was produced.

The cleaning of the glass plate in this 2nd method was performed by the cleaning apparatus 1 of the above-mentioned 1st Embodiment. In the cleaning of the glass plate by the cleaning device 1, the cleaning conditions 1 in which pure water containing no alkaline electrolyzed water is used as the rinse solution in the washing process, and the washing conditions 2 in which pure water containing alkaline electrolyzed water is used are provided. .

Similar to the first method described above, the results were obtained by visual inspection of the surface of the glass plate using light with an illuminance of 1500 lux using a fluorescent lamp and by visual inspection of the surface of the glass plate using light with an illuminance of 10000 lux using halogen lighting. Evaluation of cleaning results was performed. For Examples 6 to 10 and Comparative Example 2, each of five glass plates was inspected and evaluated on three levels of ○ (good), Δ (normal), and × (impossible).

Moreover, in the test of the 2nd method, the number of objects of minute foreign substances (microparticles) of 1 micrometer or more on the surface of the glass plate after cleaning was measured using the particle measuring machine GI7200 manufactured by Hitachi High-Tech Co., Ltd. About Examples 6-10 and Comparative Example 2, each one glass plate was measured, and the result was compared. In addition, regarding the number of objects of the fine particles, the number of objects detected within 370 mm×470 mm was converted into the number of objects per 1 m ² (1000 mm×1000 mm) and represented.

The test results are shown in Table 2. In addition, the density|concentration of an acidic washing|cleaning liquid shows the density|concentration (mass %) of glycolic acid, and the density|concentration of an alkaline washing|cleaning liquid shows the total concentration (mass %) of sodium hydroxide and potassium hydroxide. In the alkaline cleaning solution, the concentrations (mass %) of sodium hydroxide and potassium hydroxide were the same. In the results of the fluorescent lamp inspection and halogen inspection in Table 2, there is no significant difference between the glass plate after cleaning under cleaning condition 1 and the glass plate after cleaning under cleaning condition 2, so it is shown that after cleaning under cleaning condition 1 glass plate.

[Table 2]

As shown in Table 2, with respect to Examples 6 to 10, the cleaning results were judged to be good and normal. Among them, in Examples 7 and 8, the results of the fluorescent lamp inspection and the halogen inspection were both good when the number of particles was as small as 100 to 200 particles/m ² .

In Examples 6 and 10, contamination was not confirmed in the visual inspection of the fluorescent lamp, but white and extremely thin spots thought to be caused by residual lotion components were observed in the visual inspection of the halogen lamp. The number of fine particles also showed a high number of 500 to 1000/m ² .

In Example 9, no contamination was confirmed in the visual inspection of the fluorescent lamp, but microscopic foreign matter considered to be insufficient cleaning was observed in the visual inspection of the halogen lamp, and the number of particles was as high as 700 particles/m ² . . In addition, in the rinsing process, it was confirmed that, in the washing process, under the washing conditions 2 using the pure water containing alkaline electrolyzed water, compared with the washing conditions 1 using the pure water containing no alkaline electrolyzed water, in Example 6 In -10, the numerical value of the fine particles is decreased, and there is an effect of preventing the re-adhesion of foreign matter.

On the other hand, about the comparative example 2, it was judged that the stain|pollution|contamination containing an organic substance cannot be removed fully from a glass plate, and it was a cleaning failure. The number of fine particles was also as high as 10,000/m ² , and in the visual inspection, precipitation traces (stripe-shaped) were observed due to the irregularity of foreign matter remaining on the glass plate due to the irregularities on the surface of the foamed resin sheet. spot), Comparative Example 2 was defective.

Description of reference numerals

8a Upper side cleaning appliance

8b Underside cleaning appliance

15a Upper cleaning appliance

15b Underside cleaning appliance

CS1 First Cleaning Fluid

CS2 Second Cleaning Fluid

G glass plate

RS resin sheet

S1 Storage Process

S2 cleaning process

S21 The first cleaning process

S22 Liquid removal process

S23 Second cleaning process

S24 Rinsing process.

Claims (9)

1. A method for manufacturing a glass plate, comprising a storage step of storing the glass plate in contact with a resin sheet and a cleaning step of cleaning the glass plate after the storage step,

the method for manufacturing a glass sheet is characterized in that,

the cleaning step includes a first cleaning step of supplying a first cleaning liquid to the glass plate to clean the glass plate and a second cleaning step of supplying a second cleaning liquid to the glass plate after the first cleaning step to clean the glass plate,

the first cleaning solution is an acidic cleaning solution, and the second cleaning solution is an alkaline cleaning solution.

2. The method for producing glass sheet according to claim 1,

the acidic cleaning solution comprises a hydroxy acid.

3. The method for manufacturing glass plate according to claim 2,

the hydroxy acid comprises glycolic acid.

4. The method for producing glass sheet according to any one of claims 1 to 3,

the alkaline cleaning solution contains hydroxide salt.

5. The method for producing glass sheet according to any one of claims 1 to 4,

the alkaline cleaning solution contains at least one of sodium hydroxide and potassium hydroxide.

6. The method for producing glass sheet according to any one of claims 1 to 5,

in the first cleaning step, a cleaning tool is brought into contact with the glass plate to clean the glass plate.

7. The method for producing glass sheet according to any one of claims 1 to 6,

in the second cleaning step, a cleaning tool is brought into contact with the glass plate to clean the glass plate.

8. The method for producing glass sheet according to any one of claims 1 to 7,

the manufacturing method of the glass plate comprises the following liquid removing procedures: supplying a removing liquid to the glass plate after the first cleaning step and before the second cleaning step to remove the first cleaning liquid adhering to the glass plate,

the removal liquid is warm water.

9. The method for producing glass sheet according to any one of claims 1 to 8,

the method for manufacturing the glass plate comprises the following washing procedures: supplying a rinse solution to the glass plate after the second cleaning step to remove the second cleaning solution adhering to the glass plate,

the rinse solution comprises alkaline electrolyzed water.

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