JP2013203647A - Washing liquid for glass plate, washing method and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing liquid which removes sticked foreign matter adhered on the surface of a glass plate under a load or sticked foreign matter that has been changed in quality with the lapse of time, to provide a washing method and to provide a manufacturing method therefor.SOLUTION: A washing liquid is made by adding one or more kinds at a concentration of 1% or more of alkaline components selected from KOH, NaOH, ETDA-4Na, ETDA-4K, NaPO, and KPOto a diluent obtained by diluting a washing agent with water.

Description

  The present invention relates to a glass plate cleaning solution, a cleaning method, and a manufacturing method.

  Glass substrates used for flat panel displays (FPDs) such as displays for liquid crystal display devices form semiconductor elements such as TFT (Thin Film Transistor) elements by a semiconductor process. Is required to be high.

  In the manufacturing process of a glass substrate, a thin and strip-shaped glass sheet is cut into a predetermined length, and then laminated and stored as a base glass. Thereafter, the base glass is cut by being cut along a cut line (scribe line) with a diamond cutter or laser light in a predetermined size, and a glass substrate having a product size is obtained. In addition, the base glass or the glass substrate may be cut by thermal stress such as laser light. The glass substrate is subjected to processing such as grinding and polishing of the end face. Hereinafter, the base plate glass and the product-size glass substrate are collectively referred to as a glass plate.

  For example, as described in International Publication WO2009 / 008413, in order to suppress the occurrence of scratches and contamination on the surface of the glass plate during the manufacture, storage, and transportation of the glass plate for FPD, The paper is sandwiched between the two. However, depending on the material of the paper sandwiched between the glass plates, components contained in the paper may adhere to the surface of the glass plate and contaminate the surface of the glass plate.

Further, when the glass plate is cut, small glass pieces having a size of several μm to several 100 μm are scattered as dust from the cut end surface of the glass plate and adhere to the surface of the glass plate as dust.
For this reason, before packing and shipping the glass plate, the glass plate is washed so that the glass plate satisfies the shipping standard of a predetermined product. In the step of cleaning the glass plate, for example, a cleaning agent containing an alkali component as described in Japanese Patent Application No. 2007-131819 is used.

International Publication WO2009 / 008413 Japanese Patent Application No. 2007-131819

However, when recycled paper is used as the paper sandwiched between the glass plates, adhesive foreign matter having adhesiveness derived from ink, resin components, or the like contained in the recycled paper may adhere to the glass substrate.
As described in, for example, International Publication No. WO2009 / 008413, FPD glass plates are stacked by stacking recycled paper and glass plates alternately on a pallet on which the glass plates are stacked in an inclined state. In this case, the load of the glass plate loaded later is applied to the glass plate loaded previously.

  The above-mentioned adhesive foreign matter adhering to the glass plate loaded on the pallet is pressed against the glass plate under the above load, and adheres more firmly to the glass plate than the foreign matter adhering to the glass plate loaded on the pallet later. Tend. The above-mentioned adhesive foreign matter adhering to the glass plate under the above load is difficult to remove with a conventional cleaning agent diluent.

  In addition, when the above-mentioned adhesive foreign matter is stored over a long period of time, for example, several weeks to several months, the adhesive foreign matter changes in quality over time and becomes more sticky or solidifies. Dilution makes it difficult to remove.

  Therefore, the present invention is capable of effectively removing adhesive foreign matter adhering to the surface of the glass plate under load and adhesive foreign matter that has changed in quality over time. A manufacturing method is provided.

The glass plate cleaning liquid according to one embodiment of the present invention is obtained by diluting a cleaning agent with water from KOH, NaOH, ETDA-4Na, ETDA-4K, Na ₄ P ₂ O ₇ , and K ₄ P ₂ O _7. It is a glass plate cleaning solution to which one or more selected alkali components are added at a concentration of 1% or more.
In addition, the glass plate cleaning method according to another aspect of the present invention includes a cleaning step of removing foreign substances attached to the glass plate by using the glass plate cleaning liquid and cleaning the glass plate while transporting it. It is characterized by that.
Moreover, the manufacturing method of the glass plate which is another aspect of this invention wash | cleans the said glass plate by the process of taking out the said glass plate from the laminated body which laminated | stacked the glass plate and paper alternately, and said washing | cleaning method. And a process.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive foreign material which received the load and adhered to the surface of the glass plate and the adhesive foreign material which changed in quality with the passage of time can be removed effectively.

It is a figure which shows an example of the manufacturing process of the glass substrate of this embodiment. It is a schematic diagram of the pallet which mounts a glass plate. It is a figure which shows an example of a washing | cleaning process. It is a schematic diagram of a single wafer cleaning system. It is a schematic diagram of the liquid tank and cassette in a batch washing system.

Hereinafter, the manufacturing method of the glass plate of this invention is demonstrated in detail based on this embodiment.
The glass plate manufactured by this embodiment is a glass substrate used for the display for liquid crystal display devices, for example, is 0.5-0.7 mm in thickness, and is a thin plate of the size of 2200 mm x 2500 mm (length x width). is there.

  In addition, the glass plate manufactured by this embodiment is not limited to the above, Cover glass used for the display screen of electronic devices, such as a mobile telephone, a plasma display panel, organic electroluminescence (EL), etc. It may be a plate glass used for a flat panel display (FPD).

Although the glass plate manufactured by this embodiment is not specifically limited, For example, it can be applied to the glass plate of the following composition ratios. For example, any component of Li, Na, and K is not contained, or even if at least one component of Li, Na, and K is contained, It is preferable that the total amount of the components to be contained has a glass composition that is 0.5% by mass or less. The glass composition is preferably exemplified as follows.
(A) SiO ₂ : 50 to 70% by mass,
(B) B ₂ O ₃ : 5 to 18% by mass,
(C) Al ₂ O ₃ : 10 to 25% by mass,
(D) MgO: 0 to 10% by mass,
(E) CaO: 0 to 20% by mass,
(F) SrO: 0 to 20% by mass,
(G) BaO: 0 to 10% by mass,
(H) RO: 5 to 20% by mass (wherein R is at least one selected from Mg, Ca, Sr and Ba, and RO is the total of components contained in MgO, CaO, SrO and BaO),
(I) R ′ ₂ O: more than 0.05% by mass and 0.5% by mass or less (where R ′ is at least one selected from Li, Na and K, and R ′ ₂ O is Li ₂ O, Na ₂ O and the sum of the components contained in K ₂ O),
(J) 0.05 to 1.5% by mass in total of tin oxide and at least one metal oxide selected from iron oxide and cerium oxide.
The compositions (i) and (j) are not essential, but preferably include the compositions (i) and (j). The glass is substantially free of As ₂ O ₃ , Sb ₂ O ₃ and PbO and contains SnO ₂ .
Moreover, the glass used for the glass plate of this embodiment may be an alkali-free glass in which the content of R ′ ₂ O in (i) is substantially 0% by mass. That is, the glass used for the glass plate of the present embodiment is a glass containing a trace amount of alkali or a non-alkali glass containing the composition (i).

FIG. 1 is a flowchart showing the flow of the glass plate manufacturing method of the present embodiment.
As shown in FIG. 1, the melted glass is formed into a glass sheet which is a strip-shaped glass having a predetermined thickness by, for example, a down draw method or a float method (step S1).
Next, the formed glass sheet is scribed and cut to obtain a raw glass plate of a predetermined size (step S2). The obtained base glass is loaded on a pallet for storing and transporting the base glass as a laminated body alternately laminated with paper protecting the base glass (step S3).

  The base glass is transported to the cutting step, and the base glass is taken out from a laminate in which glass plates and paper are alternately stacked. The extracted base glass is scribed and cut to obtain a glass substrate having a product size (step S4). The obtained glass substrate is subjected to end face processing including end face grinding, polishing, and corner cutting (step S5). In the scribe, a cutting line (scribe line) which is a fine streak-like scratch is formed on the glass using a diamond cutter or the like. The glass plate including the base glass and the product size glass substrate is cut along a scribe line by a machine or a manual. Alternatively, the glass plate can be cut by scribing with laser light and thermal shock.

  Thereafter, the glass substrate is cleaned (step S6). The cleaned glass plate is optically inspected for scratches, dust, dirt, or scratches including optical defects (step S7). The glass plate having the quality matched by the inspection is loaded on the pallet and packed as a laminated body alternately laminated with paper protecting the glass plate (step S8). The packed glass plate is shipped to a supplier (step S9). Pulp paper that does not contain recycled paper is used as the paper that is sandwiched between the glass plates to be shipped to protect the surface of the glass plate from the viewpoint of preventing contamination of the surface of the glass plate.

  Note that the base glass may be transported and stored for a long period of time, for example, several weeks to several months after being loaded on the pallet (step S3) and packed (step S10). Recycled paper is used from the viewpoints of cost and environmental protection as the paper that is sandwiched between the glass plates to be stored to protect the surface of the glass plate. The base glass thus stored for a long period of time is then shipped through steps from cutting (step S4) to packaging (step S8) in the same manner as described above (step S9).

  Further, after the packaging (step S8), the glass substrate may be transported and stored for a long period of time, for example, several weeks to several months (step S10). Recycled paper is used as the paper that is sandwiched between the glass substrates to be stored and protects the surface of the glass substrate from the viewpoint of cost and environmental protection. Thus, the glass substrate stored for a long period of time is shipped (step S9) through the processes from cutting (step S4) to packing (step S8) in the same manner as the base glass.

  FIG. 2 is a diagram schematically showing a glass plate loaded on a pallet. As shown in FIG. 2, the glass plate G including the base glass and the glass substrate is alternately stacked with the paper P in a state where the glass plate G is leaned against the stacking portion of the pallet 100. As a result, the paper P is sandwiched between the glass plates G. In such a state, the load of the glass plate G loaded later is applied to the glass plate G previously loaded on the loading portion of the pallet 100. Therefore, the load which presses the paper P against the glass plate G becomes larger as the glass plate G is loaded first.

  In the case where the paper P is recycled paper, adhesive foreign matter having adhesiveness derived from a resin component such as ink contained in the recycled paper may adhere to the front and back surfaces of the glass plate G. Therefore, when a load as described above is applied, as the glass plate G is loaded earlier, the adhesive foreign matter receives a larger load and tends to adhere firmly to the surface of the glass plate G. The foreign matter adhering to the glass plate G under such a load cannot be sufficiently removed by cleaning using a dilute solution obtained by diluting a conventional cleaning agent.

  In addition, when the glass plate G to which the above-mentioned adhesive foreign matter adheres is cleaned through a long-term storage (step 10) as shown in FIG. 1, the above-mentioned adhesive foreign matter changes in quality over time. However, it cannot be sufficiently removed by washing with a diluting solution obtained by diluting a conventional cleaning agent with increased tackiness or solidification.

  Glass scribing and cutting (steps S2 and S4) and glass plate G end-face processing (step S5) and other mechanical processing generate glass fragments that adhere to the surface of the glass plate G as dust. To do. Alternatively, dirt attached to a tool, jig, or the like may adhere to the surface of the glass plate G during the machining.

  The glass substrate is cleaned (S5) in order to remove dust, dirt, adhesive foreign matter, and the like attached to the surface of the glass plate G as described above. In particular, since a glass substrate used for a display for a liquid crystal display device forms a semiconductor element on the surface, a high degree of cleaning is required.

Hereinafter, the cleaning process of this embodiment will be described in more detail.
FIG. 3 is a flowchart illustrating an example of the cleaning process of the present embodiment.
First, in the step (S61) of generating a diluted solution shown in FIG. 3, a glass substrate cleaning agent is diluted with water to generate a diluted solution. As the cleaning agent for the glass substrate, an inorganic alkaline cleaning agent, for example, PK-LCG series manufactured by Parker Corporation, or semi-clean series manufactured by Yokohama Oil & Fats Co., Ltd. can be used. When these cleaning agents are used, the cleaning agent is diluted with water so as to have a concentration in the range of, for example, 1 wt% to 5 wt% to generate a diluted solution.

  The water for diluting the cleaning agent may be pure water or ultrapure water that has been subjected to ion exchange treatment, EDI (Electrodeionization) treatment, filter treatment using a reverse osmosis membrane, and decarbonation treatment through a decarbonation device. It is preferable in that the surface of the glass substrate is kept clean. In order to remove the soluble foreign matter, it is preferable to pass activated carbon. Specifically, foreign substances such as fine particles are removed from the water using a filter, and after this, the activated carbon is permeated to remove organic matter, followed by ion exchange treatment, EDI (Electrodeionization) treatment, filter treatment with a reverse osmosis membrane, And it is preferable to perform a decarbonation treatment through a decarbonation device.

  In the ion exchange treatment, ionic substances contained in water, such as chlorine ions and sodium ions, are removed from the water using an ion exchange resin membrane. In the EDI treatment, an ionic substance is removed from water with higher accuracy by using an ion exchange resin membrane and utilizing a potential gradient formed by applying a potential to the electrode. Furthermore, in the filter process using a reverse osmosis membrane (RO membrane), ionic substances, salts, or organic substances are removed from water. Further, in the carbon dioxide removal treatment, carbon dioxide is removed from the water using a carbon dioxide removal device.

The concentration of the alkali component in the diluted solution generated by diluting the cleaning agent with water as described above is, for example, about 0.02 wt% to 0.15 wt% in terms of the concentration of potassium hydroxide (KOH). .
As shown in FIG. 3, in this embodiment, the diluted solution contains at least one selected from KOH, NaOH, ETDA-4Na, ETDA-4K, Na ₄ P ₂ O ₇ , and K ₄ P ₂ O ₇ . An alkaline component is added so that the total concentration is 1 wt% or more to generate a cleaning liquid (S62). The above alkali component has higher etching properties of glass and excellent solubility than other alkali components. In particular, it is preferable to use KOH alone as the alkali component from the viewpoints of etching property and solubility and preventing adverse effects on the thin film transistor formed on the glass substrate. KOH and NaOH are advantageous in terms of wastewater treatment as compared with other alkali components.

  In the present embodiment, a diluent obtained by diluting the cleaning agent with water is clearly distinguished from a cleaning solution obtained by adding the alkali component to the diluted solution. The addition of the alkali component to the diluent can be performed simultaneously with or in parallel with the dilution of the cleaning agent with water.

The total concentration of the alkali components in the cleaning liquid of the present embodiment is preferably as high as possible in terms of cleaning power for removing the sticking foreign matter. However, when the concentration of the alkali component is too high, there are problems such as corrosion of the apparatus and generation of crystals in the cleaning liquid. Therefore, it is preferable that the total concentration of the alkali components in the cleaning liquid does not exceed 10 wt%. Further, in order to facilitate handling of the cleaning liquid and not place a burden on the apparatus, it is more preferable that the total concentration of the alkali components in the cleaning liquid does not exceed 5 wt%.
The cleaning liquid generated as described above is used in single wafer cleaning of the glass plate G including brush cleaning (S63) and sponge cleaning (S64) shown in FIG.

Hereinafter, the cleaning system used for the single wafer cleaning of this embodiment will be described.
4 (a) and 4 (b) are diagrams showing an outline of a single wafer cleaning system 10 for performing wafer cleaning, FIG. 4 (a) is a plan view, and FIG. 4 (b) It is a side view. 4 (a) and 4 (b), the illustration of the conveying device that conveys the glass plate G is omitted.

  As shown in FIG. 4A, the single wafer cleaning system 10 includes a brush unit 12, a sponge unit 14, and a shower unit 16. These devices are arranged in this order from the upstream side in the conveyance direction of the glass plate G. The single wafer cleaning system 10 includes a cleaning liquid tank 18 and a pure water tank 20 as shown in FIG.

  The cleaning liquid tank 18 stores the above-described cleaning liquid generated by adding KOH at a predetermined concentration to the diluent for the glass substrate cleaning agent while keeping the temperature at a predetermined temperature. In the present embodiment, the cleaning liquid tank 18 includes temperature adjusting means such as a heater for adjusting the temperature of the cleaning liquid, and heats the cleaning liquid to a constant temperature in the range of 50 ° C. to 80 ° C. to keep the temperature.

  The nozzles 18 a and 18 b are provided so as to spray and supply the cleaning liquid supplied from the cleaning liquid tank 18 to the front and back surfaces of the glass plate G in the brush unit 12. The nozzles 18 c and 18 d are provided so as to spray and supply the cleaning liquid supplied from the cleaning liquid tank 18 to the front and back surfaces of the glass plate G in the sponge unit 14.

The pure water tank 20 stores the pure water or ultrapure water generated as described above.
The nozzles 20 a and 20 b are provided so as to inject pure water or ultrapure water supplied from the pure water tank 20 onto the front and back surfaces of the glass plate G in the shower unit 16.

  The brush unit 12 includes cleaning brush rows 12a and 12b.

  The cleaning brush rows 12a and 12b are arranged at different positions in the conveying direction of the glass plate G, that is, at an upstream position and a downstream position. The cleaning brush rows 12a and 12b are arranged so that the front and back surfaces of the glass plate G can be cleaned up and down, and are provided so as to clean the glass plate G with the glass plate G interposed therebetween.

  The cleaning brush rows 12a and 12b are each provided with a plurality of cleaning brushes in a direction crossing the conveying direction of the glass plate G. The brush unit 12 cleans the front and back surfaces of the glass plate G by rotating the cleaning brush. In the illustrated example, the cleaning brush rows 12a and 12b are provided in two rows, but three or more rows may be provided, or only one row may be provided.

  The sponge unit 14 includes cleaning sponge rows 14a and 14b.

  The cleaning sponge rows 14a and 14b are arranged at different positions in the conveying direction of the glass plate G, that is, at an upstream position and a downstream position. The cleaning sponge rows 14a and 14b are arranged so that the front and back surfaces of the glass plate G can be cleaned up and down, and are provided with the glass plate G sandwiched between them.

  The cleaning sponge rows 14a and 14b are each provided with a plurality of cleaning sponges in a direction crossing the conveying direction of the glass plate G. The sponge unit 14 cleans the front and back surfaces of the glass plate G by rotating the cleaning sponge. In the illustrated example, the cleaning sponge rows 14a and 14b are provided in two rows, but three or more rows may be provided, or only one row may be provided.

Next, the flow of cleaning the glass plate G in the single wafer cleaning system 10 will be described.
In the cleaning liquid tank 18, the cleaning liquid is kept at a predetermined temperature in the range of 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and even more preferably 70 ° C. to 80 ° C. by temperature adjusting means such as a heater.

In the brush unit 12, brush cleaning (S63) shown in FIG. 3 is performed.
The cleaning liquid supplied from the cleaning liquid tank 18 is sprayed from the nozzles 18a and 18c, and is supplied to the front and back surfaces of the glass plate G transferred into the brush unit 12 by the transfer device. The cleaning liquid supplied to the front and back surfaces of the glass plate G is heated to a predetermined temperature in the range of, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and even more preferably 70 ° C. to 80 ° C.

  In the brush unit 12, the glass plate G is in a state where a cleaning liquid having a predetermined temperature in the range of, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and further preferably 70 ° C. to 80 ° C. is present on the front and back surfaces. The front and back surfaces are cleaned by a plurality of cleaning brushes in the cleaning brush rows 12a and 12b. Thereafter, the glass plate G is transported to the sponge unit 14 by the transport device.

In the sponge unit 14, the sponge cleaning (S64) shown in FIG. 3 is performed.
The cleaning liquid supplied from the cleaning liquid tank 18 is sprayed from the nozzles 18c and 18d, and is supplied to the front and back surfaces of the glass plate G transferred into the sponge unit 14 by the transfer device. The cleaning liquid supplied to the front and back surfaces of the glass plate G is heated to a predetermined temperature in the range of, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and even more preferably 70 ° C. to 80 ° C.

  In the sponge unit 14, the glass plate G is in a state where a cleaning liquid having a predetermined temperature of, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and further preferably 70 ° C. to 80 ° C. is present on the front and back surfaces. The back surface is cleaned by a plurality of cleaning sponges in the cleaning sponge rows 14a and 14b. Thereafter, the glass plate G is transported to the shower unit 16 by a transport device.

  Pure water or ultrapure water supplied from the pure water tank 20 is sprayed from the nozzles 20a and 20b, and supplied to the front and back surfaces of the glass plate G transferred into the shower unit 16 by the transfer device. Thereby, the glass plate G is rinsed with pure water or ultrapure water, and the components of the cleaning liquid are washed away.

The glass plate G carried out from the shower unit 16 is sent to a batch cleaning system that performs batch cleaning (S65) shown in FIG. In the batch cleaning (S65), a plurality of glass plates G are accommodated in a cassette, and are sequentially immersed and cleaned in a plurality of liquid tanks.
Depending on the configuration of the single wafer cleaning system 10, batch cleaning (S65) may not be performed. In that case, the glass plate G is dried through an air knife or a heat drying step, and sent to the inspection (S7) shown in FIG.

FIG. 5 is a cross-sectional view conceptually showing one of a plurality of liquid tanks in the batch cleaning system.
The batch cleaning system includes a plurality of liquid tanks 300 illustrated in FIG. 5 and a transport mechanism that transports a cassette 200 that houses a plurality of glass plates G. Each liquid tank 300 includes an ultrasonic cleaning mechanism that cleans the glass plate G with ultrasonic waves while the glass plate G is immersed in the liquid L, and a temperature adjustment mechanism that adjusts the temperature of the liquid L as necessary. Further, the batch cleaning system includes a tank that supplies the liquid L to each liquid tank 300.

  A cassette 200 containing a plurality of glass plates G is sequentially immersed in a liquid L such as a chemical solution, a cleaning solution, pure water, ultrapure water, or functional water that is transferred by a transfer facility and stored in a liquid tank 300. Washed. As the chemical solution stored in each liquid tank 300, for example, a solution of hydrogen fluoride (HF) can be used. Moreover, the same thing as what was demonstrated by said single wafer washing | cleaning can be used for a washing | cleaning liquid, pure water, and ultrapure water. As functional water, for example, ammonia hydrogen water can be used.

  In the batch cleaning system, the type and order of the liquid L in which the glass plate G is immersed can be determined as appropriate. As an example, glass plate using first chemical solution, second pure water, third cleaning solution, fourth to sixth pure water, seventh functional water, and eighth 80 ° C to 90 ° C pure water G can be washed.

The cleaning liquid used for batch cleaning in this embodiment is the same as the cleaning liquid used in the single wafer cleaning described above, in a diluted solution obtained by diluting the glass substrate cleaning agent to 1 to 5 wt% with water, KOH, NaOH, ETDA-4Na, One or more alkali components selected from ETDA-4K, Na ₄ P ₂ O ₇ , and K ₄ P ₂ O ₇ are added at a total concentration of 1 wt% or more. The temperature of the cleaning liquid can be used in the range of, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and still more preferably 70 ° C. to 80 ° C.
Moreover, the time for which the glass plate G is immersed in each liquid tank 300 is, for example, about 60 seconds to 180 seconds, and more preferably about 100 seconds to 120 seconds.

Next, the effect | action of the washing | cleaning method of the glass plate G of this embodiment is demonstrated.
In the present embodiment, as described above, an alkaline component such as KOH is added at a concentration of 1% or more to a diluted solution produced by diluting the cleaning agent with water to produce a cleaning solution. In this way, by adding an alkaline component such as KOH at a concentration of 1 wt% or more to the diluent of the cleaning agent to generate a cleaning solution, the concentration of the alkaline component such as KOH is 7 to 50 times that of the conventional diluent. A cleaning solution about twice as high can be obtained. Although depending on the concentration of the cleaning agent in the diluent, the concentration of alkali components such as KOH in the conventional diluent is, for example, about 0.02% to 0.15%.

  A cleaning liquid containing an alkaline component such as KOH having a high concentration as in this embodiment cannot be obtained by a diluted liquid obtained by diluting a conventional cleaning agent. The reason for this is that in order for the diluting liquid to contain an alkaline component such as KOH having a concentration of 1 wt% or higher, the concentration of the alkaline component such as KOH in the cleaning agent needs to be very high. This is because the manufacture and handling of the agent is not realistic. For example, in order to obtain a diluted solution having a KOH concentration of 1 wt% or more when the cleaning agent is diluted with water to a concentration of 5 wt%, the KOH concentration of the cleaning agent must be 20 wt% or more. That is, according to the cleaning liquid manufacturing method of the present embodiment, it is possible to obtain a cleaning liquid having a higher concentration of alkali components such as KOH than ever before.

  In this embodiment, the glass plate G is cleaned using a cleaning solution having a total concentration of alkali components such as KOH of 1 wt% or more. When the concentration of alkali components such as KOH is 1 wt% or more in total, it is possible to remove the adhesive foreign matter derived from recycled paper adhering to the surface of the glass plate G regardless of the order of loading the glass plates G on the pallet. Become. That is, according to the cleaning liquid of the present embodiment, the effect of removing foreign substances including adhesive foreign matter, glass pieces, and dust that are attached to the surface of the glass plate G under load can be obtained.

  As described above, the cleaning solution in which an alkaline component such as KOH is added to the diluent for the cleaning agent so that the total concentration becomes 1% or more is higher than the concentration of the alkaline component such as KOH in the conventional cleaning solution. 7 to 50 times higher. As a result, in the cleaning liquid of the present embodiment, the alkalinity defined using, for example, the acid consumption defined in JIS K0102 is about 7 to 50 times higher than that of the conventional cleaning liquid diluent. Therefore, the etching property of the glass plate G by the cleaning liquid is improved as compared with the conventional diluted solution of the cleaning agent, and not only the glass piece and the foreign matter including dust, but also the sticking foreign matter attached to the surface of the glass plate G under the load. Is removed from the surface of the glass plate G.

  In addition, the surface tension of the cleaning liquid obtained by adding an alkaline component such as KOH to the cleaning liquid is lower than that of the conventional liquid. That is, by adding an alkaline component such as KOH to a diluent containing a surfactant, the surface tension of the cleaning agent is hardly obtained when an alkaline component such as KOH is added to pure water alone. The effect of reducing can be acquired. This makes it easier for the cleaning agent to penetrate between the adhesive foreign material and the glass plate than before, and the synergistic effect of improving the etching property of the glass plate G by the cleaning agent results in glass containing adhesive foreign material, glass pieces, and dust. Foreign matter adhering to the plate G is removed more effectively.

  Furthermore, by increasing the concentration of alkaline components such as KOH added to the diluent of the cleaning agent, it is possible to remove sticking foreign substances attached to the surface of the glass plate stored over a long period of several weeks to several months. Increases effectiveness. For example, by using a cleaning solution in which an alkaline component such as KOH is added to a diluted solution obtained by diluting the cleaning agent with pure water to 1 to 5 wt% so that the total concentration becomes 2 wt% or more, the quality of the cleaning solution changes over time. Thus, the effect of removing the adhesive foreign matter derived from recycled paper whose curing or adhesiveness has been increased by the above synergistic effect becomes more remarkable.

  The higher the concentration of alkaline components such as KOH in the cleaning liquid, the better the effect of removing adhesive foreign matter, but the burden on the cleaning device is reduced, the crystallization of the cleaning liquid components is prevented, and the cleaning liquid is easy to handle. In view of this, the concentration of alkali components such as KOH in the cleaning agent is preferably 10 wt% or less in total, more preferably 5 wt% or less, and even more preferably 3 wt% or less.

  In addition, at least one of the single wafer cleaning and the batch cleaning, the temperature of the cleaning liquid is, for example, 50 ° C. to 80 ° C., more preferably 60 ° C. to 80 ° C., and still more preferably 70 ° C. to 80 ° C. Can be softened and expanded. Due to the synergistic effect of the softening and expansion effects of the adhesive foreign matter and the effect of adding an alkaline component such as KOH to the diluent, the adhesive foreign matter attached to the front and rear surfaces of the glass plate G and subjected to a load The deteriorated adhesive foreign matter can be removed more effectively.

  As described above, according to the method for cleaning the glass plate G and the method for manufacturing the cleaning liquid of the present embodiment, not only the effect of removing various foreign matters attached to the glass plate G is improved, but also the glass plate is subjected to a load. Adhesive foreign matter derived from recycled paper adhering to the surface of G and adhesive foreign matter that has changed in quality over time can be effectively removed from the front and back surfaces of the glass plate G.

Hereinafter, examples to which the present invention is applied and comparative examples to which the present invention is not applied will be described.
The glass plates loaded on the pallet with recycled paper sandwiched between them were accommodated in a cassette, and batch cleaning was performed. As shown in Table 1 below, the glass plate was washed by changing the type of liquid contained in the first liquid tank, the second liquid tank, and the third liquid tank. In the following description, a liquid obtained by diluting a cleaning agent with water is called a diluent, and a liquid obtained by adding an alkaline component such as KOH to the diluent is called a cleaning liquid.

  In all Examples and Comparative Examples, semi-clean KG manufactured by Yokohama Oil & Fat Co., Ltd. was diluted to 2 wt% with pure water to obtain a diluted solution. Further, in the examples, a cleaning solution was obtained by adding KOH to the diluted solution so that the concentration became 1 wt%.

The number of defects on the surface of the cleaned glass plate was measured by an optical automatic inspection device. In Comparative Example 2, there was a tendency for the number of defects to increase as the glass plate was first loaded on the pallet.
On the other hand, in Example 1 and Example 2, the increase in the number of defects by the order which loaded the glass plate on the pallet was not seen. Moreover, also in the comparative example 1, the increase in the number of defects by the order which loaded the glass plate on the pallet was not seen.
In addition, when the types of foreign matters contained in the defects were analyzed, the number of adhesive foreign matters derived from substances contained in the recycled paper was the smallest in Example 2, and increased in the order of Example 1 and Comparative Example 1. Example 2 was the most common. In Examples 1 and 2, an adhesive foreign matter removal effect higher than that in Comparative Example 1 was obtained.

  Next, the glass plates loaded on the pallet with the recycled paper sandwiched between them were stored for one month or more, and single wafer cleaning and batch cleaning were performed under the conditions shown in Table 2 below.

  In all Examples and Comparative Examples shown in Table 2, semi-clean KG was diluted to 2 wt% with pure water to obtain a diluted solution. Further, in the examples, KOH was added to the diluted solution so that the concentration was 2 wt% to obtain a cleaning solution. Moreover, in the comparative example 4, the density | concentration of the semi-clean KG of the diluent used for batch washing was 4 wt%.

When the number of defects was measured by an optical automatic inspection device, Example 4 was the smallest, then Example 3 was few, then Comparative Example 4 was few, and Comparative Example 3 was the most.
When the types of foreign matters contained in the defects were analyzed, the number of adhesive foreign matters was smaller in Examples 3 and 4 than Comparative Examples 3 and 4, and in Comparative Example 4 was smaller than Comparative Example 3.

  Next, for the glass plates stacked on the pallet with recycled paper sandwiched between them, as shown in Table 3 below, the type and temperature of the liquid supplied to the front and back surfaces of the glass plates are changed. Leaf washing was performed.

When the number of defects was measured by an optical automatic inspection device, the number of defects was the smallest in Example 6, Example 5 was smaller than Comparative Example 6, and Comparative Example 5 was the largest.
When the types of foreign matters contained in the defects were analyzed, similarly, Example 6 had the smallest number, Example 5 and Comparative Example 6 increased in this order, and Comparative Example 5 had the largest number.

In the above Examples 1 to 6, the alkaline component added to the diluent was changed from KOH to NaOH, ETDA-4Na, ETDA-4K, Na ₄ P ₂ O ₇ , K ₄ P ₂ O ₇ , and the others were the same as above. Examples were obtained under the same conditions as in Examples 1-6. The example obtained in each alkali component was compared with the said Comparative Examples 1-6. As a result, in each of the examples where the cleaning was performed using the cleaning liquid in which the alkaline component was added to the diluting liquid, it was possible to confirm a higher effect of removing the adhesive foreign material than in the comparative example.

Further, KOH, NaOH, ETDA-4Na , ETDA-4K, respectively _{Na 4 P 2 O 7, K} 4 P 2 O 7, stickies using the cleaning solution was added at a concentration of 1 wt% in a diluent is attached When the glass plate was washed into single sheets and the contact angle of the glass plate with pure water was measured, the average was about 2.0 °. Moreover, when the glass plate which the adhesion foreign material adhered was batch-washed using the same washing | cleaning liquid, and the contact angle with respect to the pure water of a glass plate was measured, it was about 2.0 degrees on the average.
On the other hand, when the glass plate to which the adherent foreign material adhered was washed using a diluted solution to which the alkali component was not added and the contact angle of the glass plate with pure water was measured, the average was about 2.5 °. . Moreover, when the glass plate which the adhesion foreign material adhered was batch-washed using the same washing | cleaning liquid and the contact angle with respect to the pure water of a glass plate was measured, it was about 2.5 degrees on the average.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to said embodiment. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the glass plate for FPD has been described as the glass plate, but the present invention is not limited to the glass plate for FPD.

10 single wafer cleaning system 12 brush unit 12a, 12b cleaning brush row 14 sponge unit 14a, 14b cleaning sponge row 16 shower unit 18 cleaning liquid tank 18a, 18b, 18c, 18d nozzle 20 pure water tank 20a, 20b nozzle 100 pallet 200 cassette 300 Liquid tank G Glass plate L Liquid P Paper

Claims (8)

1% or more of one or more alkali components selected from KOH, NaOH, ETDA-4Na, ETDA-4K, Na ₄ P ₂ O ₇ , and K ₄ P ₂ O _{7 are} added to a diluted solution obtained by diluting the cleaning agent with water. Glass plate cleaning solution added at a concentration of. The alkaline component is KOH;
The glass plate cleaning liquid according to claim 1. Using the glass plate cleaning liquid according to claim 1 or 2,
A method for cleaning a glass plate, comprising a cleaning step of cleaning the glass plate while transporting it to remove foreign matter adhering to the glass plate. Before the cleaning step, the glass plate is laminated with recycled paper sandwiched between them,
The foreign matter is an adhesive foreign matter derived from a substance contained in the recycled paper.
The glass plate cleaning method according to claim 3. The foreign matter is the adhesive foreign matter that has received a load due to the lamination.
The method for cleaning a glass plate according to claim 4. The foreign matter is the adhesive foreign matter that has changed in quality over time.
The method for cleaning a glass plate according to claim 4 or 5. In the cleaning step, the temperature of the cleaning liquid is set higher than 60 ° C.,
The glass plate cleaning method according to any one of claims 3 to 6. A step of taking out the glass plate from a laminate in which glass plates and paper are alternately laminated;
Cleaning the glass plate by the cleaning method according to any one of claims 3 to 7,
The manufacturing method of the glass plate which has.

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