JP6670104B2 - Cleaning solution for glass substrate for color filter and method for cleaning glass substrate for color filter - Google Patents

Description

  The present invention relates to a cleaning solution for a glass substrate for a color filter and a method for cleaning a glass substrate for a color filter.

  Conventionally, in a manufacturing process of a glass sheet (glass substrate), a step of cleaning the surface of the glass sheet is performed after a step of forming the glass sheet from a glass raw material. In the glass sheet cleaning process, a process of cleaning the surface of the glass sheet with an acidic or alkaline chemical solution, ultrasonic waves, or the like, in order to remove fine particles, dust, dirt, and other foreign substances attached to the surface of the glass sheet. Done.

  Glass sheets used for manufacturing displays such as liquid crystal displays and plasma displays include black matrix and RGB pixels, which are wavelength selection elements that transmit red (R), green (G), and blue (B) light. Are arranged on the surface to form a color filter. The black matrix improves display contrast by blocking light leakage of the backlight in areas other than the RGB pixel area and preventing color mixing of RGB pixels adjacent to each other. That is, the light passage area of the color filter is determined by the shape and arrangement of the black matrix.

  In recent years, the line width and pitch of a black matrix arranged on the surface of a glass sheet have been reduced with the increase in definition of a display. In order to achieve higher definition of the display, higher definition of the black matrix is required. As the definition of the black matrix increases, it is necessary to achieve high adhesion of the black matrix resin to the surface of the glass substrate with higher accuracy. By the way, the surface of a glass substrate used for manufacturing a display is required to have high cleanliness. Therefore, in order to remove foreign substances adhering to the surface of the glass substrate, a method of cleaning the surface of the glass substrate using an inorganic alkali-based cleaning agent has been used as disclosed in Patent Document 1. .

JP 2001-181686 A

  However, in the cleaning method using such a cleaning agent, high adhesion of the black matrix resin to the glass substrate surface may not be sufficiently achieved due to organic substances remaining on the surface of the glass substrate after cleaning. is there.

  Accordingly, an object of the present invention is to provide a cleaning solution for a glass substrate for a color filter and a method for cleaning a glass substrate for a color filter, which can suppress a decrease in adhesion of a black matrix resin to the surface of a glass substrate.

One embodiment of the present invention is a cleaning liquid for a glass substrate for a color filter,
A diluent having a concentration of 1.5% to 4% of a detergent obtained by diluting the detergent with water, KOH, NaOH, EDTA-4Na, EDTA-4K , Na ₄ P ₂ O ₇ , and K ₄ P ₂ O ₇ Adding the alkali component to the diluent such that the total concentration of one or more alkali components selected from the group is 0.2% to 1%,
It is characterized by the following.

Another embodiment of the present invention is a cleaning solution for a glass substrate for a color filter, the black matrix resin is formed on the surface,
Having a cloud point determined by the concentration of the detergent and the concentration of the alkali component,
The concentration of the cleaning agent is 1.5% to 4%,
The alkali component comprises one or more alkali components selected from KOH, NaOH, EDTA-4Na, EDTA-4K , Na ₄ P ₂ O ₇ , and K ₄ P ₂ O ₇ ,
The cloud point is 75 ° C. or higher;
It is characterized by the following.

The alkali component is KOH,
The addition of the KOH is preferably in a range where the cloud point is 75 ° C. or higher.

  It is preferable that the detergent comprises an inorganic alkali-based detergent containing a surfactant.

Another aspect of the present invention is a method for cleaning a glass substrate, comprising a cleaning step of removing foreign matter attached to the glass substrate using the cleaning solution for a glass substrate for a color filter described above,
Before the cleaning step, the glass substrate is laminated with recycled paper interposed therebetween,
The foreign matter is an adhesive foreign matter derived from a substance contained in the recycled paper,
It is characterized by the following.

  In the cleaning step, it is preferable that the temperature of the cleaning liquid is higher than 60 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the adhesion of the black matrix resin to the glass substrate surface can be suppressed.

It is a figure showing an example of a manufacturing process of a glass substrate of this embodiment. It is a schematic diagram of a pallet on which a glass substrate is loaded. It is a figure showing an example of a washing process. It is a schematic diagram of a single wafer cleaning system. It is the figure which showed the cloud point which changes with the density | concentration of a detergent, and the density | concentration of an alkali component.

Hereinafter, a method for manufacturing a glass plate (glass substrate, sheet glass) of the present invention will be described in detail based on the present embodiment.
The glass plate manufactured in the present embodiment is a glass substrate used for a display for a liquid crystal display device, for example, a thin plate having a thickness of 0.3 to 0.7 mm and a size of 2200 mm × 2500 mm (length × width). is there.

  The glass plate manufactured in this embodiment is not limited to the above, and may be a cover glass used for a display screen of an electronic device such as a mobile phone, a plasma display panel, an organic electroluminescence (EL), or the like. It may be a plate glass used for a flat panel display (FPD).

The glass plate manufactured in the present embodiment is not particularly limited, but may be applied to, for example, a glass plate having the following composition ratio. For example, if none of the components Li, Na, and K are contained, or even if at least one component of Li, Na, and K is contained, of Li, Na, and K, It is preferable to have a glass composition in which the total amount of the contained components is 0.5% by mass or less. Preferred examples of the glass composition include the following.
(A) SiO ₂ : 50 to 70% by mass,
(B) B2O _3: 5~18 wt%,
(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 (where R is at least one selected from Mg, Ca, Sr and Ba, and RO is the sum 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 Sum of components contained in ₂ O and K ₂ O),
(J) Tin oxide and at least one metal oxide selected from iron oxide and cerium oxide in a total amount of 0.05 to 1.5% by mass.
The compositions (i) and (j) are not essential, but preferably include the compositions (i) and (j). The above glass contains SnO ₂ substantially without As ₂ O ₃ , Sb ₂ O ₃ and PbO.
Further, the glass used for the glass plate of the present 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 containing the composition (i) or a non-alkali glass.

FIG. 1 is a flowchart showing the flow of the method for manufacturing a glass sheet of the present embodiment.
As shown in FIG. 1, the molten glass is formed into a glass sheet that is a band-shaped glass having a predetermined thickness by, for example, a downdraw method or a float method (Step S1).
Next, the formed glass sheet is scribed and cut to obtain a base glass having a predetermined size (step S2). The obtained base glass is stacked on a pallet for housing and transporting the base glass as a laminated body alternately stacked with paper for protecting the base glass (step S3).

  The raw glass is conveyed to a cutting step, and the raw glass is taken out of a laminate in which glass plates and paper are alternately laminated. The extracted raw glass is scribed and cut to obtain a glass substrate of a product size (step S4). The obtained glass substrate is subjected to edge processing including grinding, polishing, and corner cutting of the edge (step S5). In the above scribe, a cut line (scribe line), which is a minute streak-like flaw, is formed in glass using a diamond cutter or the like. Cutting of the glass sheet including the raw glass sheet and the glass substrate of the product size is cut by a machine or manually along a scribe line. 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 a quality conforming to the inspection is loaded on a 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). From the viewpoint of preventing the surface of the glass plate from being contaminated, pulp paper containing no recycled paper is used as the paper sandwiched between the glass plates to be shipped and protecting the surface of the glass plate.

  After the raw glass is loaded on the pallet (step S3) and packed, the raw glass 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 sandwiched between the stored raw glass sheets to protect the surface of the raw glass sheets from the viewpoint of cost and environmental protection. The raw glass sheet thus stored for a long period of time is then shipped (step S9) through the steps from cutting (step S4) to packing (step S8) as described above.

  After packing (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 paper for protecting the surface of the glass substrate by being sandwiched between the glass substrates to be stored, from the viewpoint of cost and environmental protection. The glass substrate thus stored for a long period of time is shipped (step S9) through processes from cutting (step S4) to packing (step S8), similarly to the plain glass.

  FIG. 2 is a diagram schematically showing a glass plate loaded on a pallet. As shown in FIG. 2, the glass sheet G including the elementary glass sheet and the glass substrate is alternately stacked on the interleaving paper P in a state where the glass sheet G is leaned obliquely on the loading portion of the pallet 100. As a result, the interleaf paper P is sandwiched between the glass plates G. In such a state, the load of the glass plate G loaded later on the glass plate G loaded earlier on the loading portion of the pallet 100 is applied. Therefore, the load that presses the slip sheet P against the glass plate G increases as the glass plate G is loaded earlier.

  When the slip sheet P is a recycled paper, adhesive foreign matters 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. For this reason, when the above-mentioned load is applied, the larger the glass plate G loaded, the larger the load of the adhesive foreign matter, and the more strongly the adhesive foreign matter tends to adhere to the surface of the glass plate G. The foreign matter attached to the glass plate G under such a load cannot be sufficiently removed by the conventional cleaning using a diluent obtained by diluting a cleaning agent.

  Further, when the glass plate G to which the above-mentioned adhesive foreign matter has adhered is washed through a long-term storage (step 10) as shown in FIG. 1, the above-mentioned adhesive foreign matter is deteriorated with the passage of time. However, it cannot be sufficiently removed by washing with a diluent obtained by diluting a conventional detergent with increasing or solidifying the adhesive.

  By machining such as scribing and cutting the glass plate G (steps S2 and S4) and processing the end surface of the glass plate G (step S5), small pieces of glass are generated and adhere to the surface of the glass plate G as dust. I do. Alternatively, during the above-described machining, dirt attached to a tool, a jig, or the like may adhere to the surface of the glass plate G.

  The glass substrate is washed (S5) in order to remove dust, dirt, sticky foreign substances and the like attached to the surface of the glass plate G as described above. In particular, a glass substrate used for a display for a liquid crystal display device requires a high degree of cleaning because a semiconductor element is formed on the surface.

Hereinafter, the cleaning step of the present embodiment will be described in more detail.
FIG. 3 is a flowchart illustrating an example of the cleaning process according to the present embodiment.
First, in a step (S61) of generating a diluting liquid shown in FIG. 3, a cleaning liquid for a glass substrate is diluted with water to generate a diluting liquid. As the cleaning agent for the glass substrate, an inorganic alkali-based cleaning agent, for example, PK-LCG series manufactured by Parker Corporation, or semi-clean series manufactured by Yokohama Yushi Kogyo KK 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 diluent. More preferably, the cleaning agent is diluted with water so as to have a concentration ranging from 1.5 wt% or more to 4 wt% or less to generate a diluent.

  The water for diluting the detergent may be pure water or ultrapure water that has been subjected to ion exchange treatment, EDI (Electrodeionization) treatment, filter treatment with a reverse osmosis membrane, and decarbonation treatment through a decarbonation device. This is preferable in that the surface of the glass substrate is kept clean. Activated carbon is preferably passed through to remove soluble foreign substances. Specifically, foreign matter such as fine particles is removed from water using a filter, and thereafter, activated carbon is permeated to remove organic substances. Then, ion exchange treatment, EDI (Electrodeionization) treatment, filter treatment with a reverse osmosis membrane, It is preferable to perform a decarbonation treatment through a decarbonation device.

  In the ion exchange treatment, ionic substances contained in water, for example, chloride ions and sodium ions, are removed from water using an ion exchange resin membrane. In the EDI treatment, an ionic substance is more accurately removed from water using an ion exchange resin membrane and a potential gradient formed by applying a potential to an electrode. Further, in the filter treatment using a reverse osmosis membrane (RO membrane), ionic substances, salts, or organic substances are removed from water. Further, in the decarbonation treatment, carbon dioxide is removed from water using a decarbonation device.

As described above, the concentration of the alkaline component of the diluent produced by diluting the detergent with water is, for example, about 0.02 wt% to about 0.15 wt% in terms of the concentration of potassium hydroxide (KOH). .
As shown in FIG. 3, in the present embodiment, one or more kinds selected from KOH, NaOH, EDTA-4Na, EDTA-4K , Na ₄ P ₂ O ₇ , and K ₄ P ₂ O _{7 are} added to the diluent. A cleaning liquid is generated by adding an alkali component so that the total concentration becomes 0.2 wt% or more and 1 wt% or less (S 62). The above alkali component has a higher etching property of glass and is more excellent in solubility than other alkali components. In particular, it is preferable to use KOH alone as the above-mentioned alkali component, from the viewpoints of etching properties and solubility, and preventing adverse effects on thin film transistors formed on a glass substrate. KOH and NaOH are advantageous in terms of wastewater treatment as compared with other alkaline components.

  In the present embodiment, a diluting solution obtained by simply diluting a cleaning agent with water and a cleaning solution obtained by adding the above-described alkali component to the diluting solution are clearly distinguished. The addition of the alkali component to the diluent can be performed simultaneously with or concurrently with the dilution of the detergent with water.

  In addition, it is preferable that the total concentration of the alkaline components in the cleaning liquid of the present embodiment is as high as possible from the viewpoint of the cleaning power for removing the adhesive foreign matter. However, if the concentration of the alkali component is too high, the black matrix resin applied to the surface of the glass substrate cannot maintain high adhesion, and may cause corrosion of the apparatus or generate crystals in the cleaning solution. There's a problem.

  In the present embodiment, a cleaning liquid obtained by adding the above-described alkali component to a diluting liquid obtained by diluting a cleaning agent with water is indicated by a cloud point. Here, the cloud point is an index uniquely determined by the concentration of the cleaning agent and the concentration of the alkali component, and phase change occurs due to a change in the temperature of the cleaning solution, and the cleaning agent dissolved in the cleaning solution and some components of the alkali component Is the temperature at which precipitation begins. When an alkaline component such as KOH is added to the detergent, the hydrogen bond between the surfactant and water is broken, and the solubility in water is rapidly reduced, so that the detergent becomes opaque. This opaque temperature is the cloud point. When a cleaning liquid having a cloud point or higher is used for cleaning a glass substrate, the precipitated cleaning agent and alkali components may adhere to the glass substrate. In the cleaning of the glass substrate (S5), even if the cleaning liquid can be used to remove dust, dirt, sticky foreign matter, and the like adhered to the surface of the glass substrate, the cleaning agent and the alkaline component remain on the surface of the glass substrate. In this case, there is a problem that high adhesion of the black matrix resin applied to the surface of the glass substrate cannot be realized due to the detergent and the alkali component remaining on the surface of the glass substrate. Therefore, it is necessary to clean the glass substrate using a cleaning solution that can remove dust, dirt, sticky foreign matter, and the like attached to the surface of the glass substrate and that does not leave a cleaning agent or an alkaline component. The high adhesion of the black matrix resin to the surface of the glass substrate can be realized by removing the cleaning agent and the alkali component while removing dust, dirt, adhesive foreign matters, and the like.

  In the cleaning liquid of the present embodiment, the concentration of the cleaning agent and the concentration of the alkali component are set so that the cloud point is 75 ° C. or higher. As described above, the concentration of the cleaning agent is adjusted to be in the range of 1.5 wt% or more to 4 wt% or less. When the concentration of the cleaning agent exceeds 4 wt%, when the glass substrate is cleaned using the cleaning agent, the amount of the detergent residue remaining on the surface of the glass substrate increases, so that the adhesion of the black matrix resin decreases. For this reason, the concentration of the cleaning agent is determined so that the concentration of the cleaning agent is 4 wt% or less. On the other hand, if the concentration of the cleaning agent is less than 1.5 wt%, dust, dirt, sticky foreign substances, and the like attached to the surface of the glass substrate cannot be removed when the glass substrate is cleaned using the cleaning agent. Therefore, the concentration of the cleaning agent is determined so that the concentration of the cleaning agent is 1.5 wt% or more.

  As described above, the concentration of the alkali component in the cleaning liquid is adjusted so that the cloud point is in a range of 75 ° C. or higher. Here, the alkali component is preferably KOH as the alkali component from the viewpoints of etching properties and solubility, and preventing adverse effects on the thin film transistor formed on the glass substrate. When the cloud point is less than 75 ° C., when the glass substrate is washed with the cleaning agent, the amount of organic substances derived from alkali components remaining on the surface of the glass substrate increases, so that the adhesion of the black matrix resin decreases. For this reason, the concentration of the alkali component is determined so that the cloud point is 75 ° C. or higher. On the other hand, if the concentration of the alkali component is less than 0.2 wt%, dust, dirt, sticky foreign substances, and the like attached to the surface of the glass substrate cannot be removed when the glass substrate is cleaned with the cleaning agent. For this reason, the concentration of the alkali component is determined so that the concentration of the alkali component becomes 0.2 wt% or more.

KOH is added to a cleaning agent having a concentration in the range of 1.5 wt% or more to 4 wt% or less so that the cloud point of the cleaning liquid is 75 ° C. or more, to generate the cleaning liquid of the present embodiment. Using a PK-LCG series manufactured by Parker Corporation or a semi-clean series manufactured by Yokohama Yushi Kogyo Co., Ltd. as a cleaning agent, the concentration of the cleaning agent is adjusted to a concentration in a range of 1.5 wt% or more to 4 wt% or less. By adding KOH having a concentration in the range of 0.2 wt% or more to 1 wt% or less to the diluted cleaning agent, the cleaning solution of the present embodiment having a cloud point of 75 ° C. or higher can be generated. .

  The cleaning liquid generated as described above is used in single-wafer cleaning and batch cleaning of the glass plate G including brush cleaning (S63) and sponge cleaning (S64) shown in FIG. In the following, a method of using the cleaning liquid of the present embodiment for single wafer cleaning will be described, but the cleaning liquid can also be used for batch cleaning.

Hereinafter, a cleaning system used for single wafer cleaning will be described.
FIGS. 4A and 4B are diagrams schematically illustrating a single-wafer cleaning system 10 for performing single-wafer cleaning. FIG. 4A is a plan view, and FIG. It is a side view. 4 (a) and 4 (b), illustration of a transfer device for transferring the glass plate G is omitted.

  The single wafer cleaning system 10 includes a brush unit 12, a sponge unit 14, and a shower unit 16, as shown in FIG. These devices are arranged in this order from the upstream side in the transport direction of the glass sheet 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 cleaning liquid generated by adding KOH at a predetermined concentration to a diluting liquid of a cleaning agent for a glass substrate while maintaining the temperature at a predetermined temperature. In the present embodiment, the cleaning liquid tank 18 is provided with a 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. More preferably, the cleaning solution is kept at a temperature in the range of 60 ° C to 75 ° C.

  The nozzles 18a and 18b are provided so that the cleaning liquid supplied from the cleaning liquid tank 18 is jetted onto the front and back surfaces of the glass plate G in the brush unit 12 and supplied. The nozzles 18c and 18d 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 the ultrapure water generated as described above.
The nozzles 20 a and 20 b are provided so that pure water or ultrapure water supplied from the pure water tank 20 is jetted onto the front and back surfaces of the glass plate G in the shower unit 16 and supplied.

  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 the upstream position and the downstream position. The cleaning brush rows 12a and 12b are arranged vertically so that the front and back surfaces of the glass plate G can be cleaned, and are provided so as to clean the glass plate G with the glass plate G interposed therebetween.

  Each of the cleaning brush rows 12a and 12b includes a plurality of cleaning brushes in a direction crossing the transport 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, two cleaning brush rows 12a and 12b are provided, 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 transport direction of the glass sheet G, that is, at an upstream position and a downstream position. The cleaning sponge rows 14a and 14b are arranged vertically so as to be able to clean the front and back surfaces of the glass plate G, and are provided so that the glass plate G is interposed therebetween for cleaning.

  Each of the cleaning sponge rows 14a and 14b includes a plurality of cleaning sponges in a direction crossing the transport direction of the glass sheet 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, two cleaning sponge rows 14a and 14b are provided, but three or more rows may be provided, or only one row may be provided.

Next, a flow of cleaning the glass plate G in the single wafer cleaning system 10 will be described.
The cleaning liquid is kept in the cleaning liquid tank 18 at a predetermined temperature in the range of 60 ° C. to 80, more preferably 60 ° C. to 75 ° C., by a temperature control 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 jetted from the nozzles 18a and 18c, and is supplied to the front and back surfaces of the glass plate G transported into the brush unit 12 by the transport device. The cleaning liquid supplied to the front and back surfaces of the glass plate G is heated to, for example, a predetermined temperature in the range of 60 ° C. to 75 ° C., more preferably 65 ° C. to 75 ° C.

  In the brush unit 12, the cleaning plate having a predetermined temperature in the range of, for example, 60 ° C. to 75 ° C., and more preferably 65 ° C. to 75 ° C. exists on the front and back surfaces of the glass plate G. It is cleaned by a plurality of cleaning brushes 12b. Thereafter, the glass plate G is transferred to the sponge unit 14 by the transfer 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 jetted from the nozzles 18c and 18d, and supplied to the front and back surfaces of the glass plate G transported into the sponge unit 14 by the transport device. The cleaning liquid supplied to the front and back surfaces of the glass plate G is heated to, for example, a predetermined temperature in the range of 60 ° C to 75 ° C, more preferably 65 ° C to 75 ° C.

  In the sponge unit 14, the glass plate G has a cleaning sponge array 14a, 14b whose front and back surfaces have a predetermined temperature of 60 to 75 ° C, more preferably 65 to 75 ° C. It is cleaned by a plurality of cleaning sponges. Thereafter, the glass plate G is transferred to the shower unit 16 by the transfer device.

  The pure water or ultrapure water supplied from the pure water tank 20 is jetted from the nozzles 20a and 20b, and supplied to the front and back surfaces of the glass plate G transported into the shower unit 16 by the transport 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 of the shower unit 16 is sent to a batch cleaning system for performing batch cleaning (S65) shown in FIG. In the batch cleaning (S65), a plurality of glass plates G are housed in a cassette and sequentially dipped and cleaned in a plurality of liquid tanks.
Note that, 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 heating and drying process, and is sent to the inspection (S7) shown in FIG.

Next, the operation of the method for cleaning the glass plate G of the present embodiment will be described.
In this embodiment, as described above, an alkaline component such as KOH is added to a diluent having a concentration range of 1.5 wt% or more and 4 wt% or less, which is generated by diluting the cleaning agent with water to generate a cleaning liquid. As described above, by adding an alkaline component such as KOH at a concentration of 0.2 wt% or more to the diluent of the cleaning agent to generate the cleaning liquid, a cleaning liquid having a cloud point of 75 ° C. or higher can be obtained.

  In the present embodiment, the glass plate G is cleaned using a cleaning liquid having a cloud point of 75 ° C. or higher in the concentration of an alkaline component such as KOH. Even if the concentration of the alkali component such as KOH is higher than the cloud point of 75 ° C., it is possible to remove the adhesive foreign matter derived from recycled paper adhered to the surface of the glass plate G regardless of the order in which the glass plates G are stacked on the pallet. Will be possible. That is, according to the cleaning liquid of the present embodiment, the effect of removing foreign substances including adhesive foreign substances, glass pieces, and dust adhered to the surface of the glass plate G under a load can be obtained. In addition, by using a cleaning solution having a cloud point of 75 ° C. or higher in a temperature range of 65 ° C. to 75 ° C., the detergent and alkali components dissolved in the cleaning solution do not precipitate, so Residual organic substances are suppressed, and high adhesion of the black matrix resin to the surface of the glass plate G can be realized.

  As described above, the cleaning solution obtained by adding an alkali component such as KOH to the cleaning solution diluent at a concentration at which the cloud point becomes 75 ° C. or higher improves the etching property of the glass plate G by the cleaning solution as compared with the conventional cleaning solution diluent. In addition, not only foreign substances including glass pieces and dust but also adhesive foreign substances adhering to the surface of the glass sheet G under a load can be removed from the surface of the glass sheet G by peeling. In addition, by using a cleaning solution having a cloud point at a temperature lower than the cloud point, organic residues due to the cleaning agent and the like are suppressed, and high adhesion of the black matrix resin to the surface of the glass plate G is realized. Can be.

  In addition, the surface tension of the cleaning liquid obtained by adding an alkali component such as KOH to the diluting liquid of the cleaning agent is lower than that of the conventional diluting liquid. That is, by adding an alkali component such as KOH to a diluent of a detergent containing a surfactant, the surface tension of the detergent is hardly obtained when an alkali component such as KOH is solely added to pure water. The effect of lowering can be obtained. This makes it easier for the detergent to penetrate between the adhesive foreign matter and the glass plate than before, and the synergistic effect with the improvement of the etching property of the glass plate G by the detergent causes the glass containing the adhesive foreign matter, glass fragments, and dust. Foreign matter adhering to the plate G is more effectively removed.

  Furthermore, by increasing the concentration of an alkaline component such as KOH added to the diluent of the cleaning agent, it is possible to remove sticky foreign substances adhering to the surface of the glass plate stored for a long period of several weeks to several months or more. The effect is higher. For example, by using a cleaning solution in which an alkali component such as KOH is added to a diluting solution obtained by diluting a cleaning agent to 1.5 wt% to 5 wt% with pure water at a concentration at which the cloud point becomes 75 ° C. or higher, the time elapses. The effect of removing the adhesive foreign matter derived from recycled paper, which has been modified and hardened or increased in adhesiveness, by the above synergistic effect becomes more remarkable.

  In addition, the higher the concentration of the alkaline component such as KOH in the cleaning liquid, the higher the effect of removing the sticky foreign substances. However, the viewpoint of suppressing the residue of the organic substance derived from the cleaning liquid and the burden on the cleaning apparatus are reduced, and the cleaning liquid is reduced. From the viewpoint of preventing crystallization of the components and facilitating the handling of the cleaning solution, the concentration of the alkali component such as KOH of the cleaning agent is preferably at a cloud point of 75 ° C. or higher. By making the concentration of the alkali component a cloud point of 75 ° C. or higher, even when the cleaning solution is used in a temperature range of 60 ° C. to 75 ° C. where the effect of the cleaning solution is easily obtained, the surfactant dissolved in the cleaning solution may precipitate. Therefore, the residue of organic substances based on the surfactant can be suppressed.

In addition, by using the temperature of the cleaning liquid in a range of, for example, 60 ° C. to 75 ° C., and more preferably 65 ° C. to 75 ° C., at least one of single-wafer cleaning and batch cleaning, the adhesive foreign matter can be softened and expanded. Due to the synergistic effect of the softening and expanding effects of the adhesive foreign matter and the effect of adding an alkali component such as KOH to the diluting solution, the adhesive foreign matter attached to the front and back surfaces of the glass plate G and receiving the load and the passage of time. The altered adhesive foreign matter can be more effectively removed. Further, by using the temperature of the cleaning liquid at 75 ° C. or lower, it is possible to prevent the cleaning liquid from being phase-separated and to precipitate a part of the cleaning agent and the alkali component. Is reduced, and high adhesion of the black matrix resin to the surface of the glass plate G can be realized.

  As described above, according to the cleaning liquid of the present embodiment and the method for cleaning the glass plate G using the cleaning liquid, not only the effect of removing various foreign substances attached to the glass plate G is improved, but also the load As a result, the adhesive foreign substances originating from recycled paper and the adhesive foreign substances that have changed in quality over time can be effectively removed from the front and back surfaces of the glass sheet G. Further, since the residue of the cleaning agent after the cleaning is suppressed, high adhesion of the black matrix resin to the surface of the glass plate G can be realized.

(Example 1)
The cloud point of the cleaning solution was measured while changing the concentration of the cleaning agent and the concentration of the alkali component. Semi-clean KG, an inorganic alkaline cleaner manufactured by Yokohama Yushi Kogyo Co., Ltd., and KOH as an alkaline component, dilute semi-clean KG with pure water to obtain a diluent, and add KOH to the diluent. Thus, a washing solution was obtained. FIG. 5 is a diagram showing the cloud point that changes depending on the concentration of the cleaning agent and the concentration of the alkali component. By changing the concentration of KG of the cleaning agent and the concentration of KOH as the alkaline component, the cloud point of the cleaning solution changes as shown in the figure, and the cloud point varies depending on the concentration of the cleaning agent and the concentration of the alkaline component. Was determined to be uniquely determined. By using the cleaning liquid in a temperature range below the uniquely determined cloud point, phase separation of the cleaning liquid can be prevented, and residues of organic substances derived from the cleaning liquid can be suppressed.

(Example 2)
Hereinafter, Examples to which the present invention is applied and Comparative Examples to which the present invention is not applied will be described.
In this example, after cleaning the glass plate, the number of deposits adhered to the surface of the glass plate was measured, and the cleaning power was compared. Hereinafter, a specific procedure will be described.

Sample used for particle removal evaluation (1) Cleaning agent: Semi-clean KG, an inorganic alkaline cleaning agent manufactured by Yokohama Yushi Kogyo Co., Ltd.
(2) Alkaline component: KOH
(3) Glass plate: non-alkali glass (4) Deposits: CeO for polishing ₂ Particle size 1 μm to 4 μm
In all Examples and Comparative Examples, semi-clean KG was diluted with pure water to obtain a diluent, and KOH was added to the diluent to obtain a cleaning liquid.
Sample used for evaluation of removal of sticky foreign matter (1) Cleaning agent: Semi-clean KG, an inorganic alkaline cleaning agent manufactured by Yokohama Yushi Kogyo Co., Ltd.
(2) Alkaline component: KOH
(3) Glass plate: non-alkali glass (4) Deposits: PVC glove In all Examples and Comparative Examples, semi-clean KG was diluted with pure water to obtain a diluent, and KOH was added to the diluent. A washing solution was obtained.

First, in one sample, CeO ₂ for polishing is dispersed in pure water to form a slurry, and the slurry-like CeO ₂ is rubbed on a clean glass plate. The surface of the glass plate G on which the slurry-like CeO ₂ is rubbed is washed with pure water to remove excess CeO ₂ . Next, the glass plates G shown in FIG. 2 are alternately stacked with the interleaf paper P, and are attached to the glass plate G by pressing the interleaf paper P against the glass plate G, and correspond to particles. The other sample was obtained by attaching a mark of PVC gloves used in a clean room to a clean glass plate and baking it at 170 ° C. for 60 seconds in a clean oven, which corresponds to an adhesive foreign substance. The glass plate G was sponge-cleaned using cleaning solutions having different cleaning agent concentrations, alkali component (KOH) concentrations, cleaning solution temperatures, and cloud points shown in Tables 1 and 2 below. After the sponge washing, the glass plate G was washed with pure water and then dried. Then, the number of particles adhering to the surface of the glass plate G having been washed and dried was measured by an optical automatic inspection device. In addition, the amount of organic substances remaining on the surface of the glass plate G after cleaning of the particle evaluation sample was measured by GC-MS. The sticky foreign substance sample was visually confirmed using a light collector. Here, the particles shown in Tables 1 and 2 are deposits such as CeO ₂ and glass pieces, dust, and dirt. The organic substances are deposits of interleaf P components and detergent residues. Is a deposit.

However,
Particle removal state ○ = 98% or more, Δ = 95% or more and less than 98%, × = less than 95%.
Organic residue state (residue per 1 cm ² ) ＝= 0.05 ng or more and less than 0.10 ng, ＝= 0.10 ng or more and less than 0.25 ng, △ = 0.25 ng or more and less than 0.50 ng, and X = 0.50 ng or more.
Adhesive foreign matter removed state ○ = no residue, △ = slight residue, × = many residues.

  The cleaning liquids shown in Examples 1 to 6 in Table 1 have a cloud point of 75 ° C. or more when the concentration of the cleaning agent is in a range of 1.5 wt% to 4 wt%, and soften and expand the adhesive foreign matter attached to the glass plate. By using the cleaning liquid at a temperature of 60 ° C. to 75 ° C., the phase separation of the cleaning liquid can be prevented, and the residue derived from the cleaning liquid can be suppressed, so that the organic residue is less than 0.50 ng. And could be. In addition, the removal state of the particles was 95% or more. It was confirmed that the cleaning liquids shown in Examples 1 to 6 in Table 1 can suppress organic residues while removing particles. From the above, the cleaning liquid having a cleaning agent concentration of 1.5 wt% to 4 wt%, containing an alkaline component of KOH, and having a cloud point of 75 ° C. or higher can suppress organic residues, so that the black matrix resin has It was confirmed that the composition was suitable for cleaning the color filter glass substrate formed in the above.

It was confirmed that the cleaning liquids shown in Comparative Examples 1 and 2 in Table 2 had a low cleaning power due to the low concentration of the cleaning agent or KOH, and were not able to sufficiently remove particles or sticky foreign substances.
The cleaning liquids shown in Comparative Examples 3 to 6 in Table 2 have a cloud point of less than 75 ° C, and are used at a temperature of 60 ° C to 75 ° C of the cleaning liquid capable of softening and expanding the adhesive foreign matter attached to the glass plate. When used, phase separation of the cleaning liquid occurs. It was confirmed that the organic residue was 0.50 ng or more even after washing. For this reason, it was confirmed that the cleaning liquid having a cloud point of less than 75 ° C. is not suitable for cleaning a glass substrate for a color filter on which a black matrix resin is formed on the surface, because the adhesion of the black matrix resin is reduced due to an organic residue. did it.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. Additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the description has been made using the glass plate for FPD as the glass plate, but the present invention is not limited to the glass plate for FPD.

10 Single-wafer cleaning system 12 Brush units 12a, 12b Cleaning brush array 14 Sponge units 14a, 14b Cleaning sponge array 16 Shower unit 18 Cleaning liquid tanks 18a, 18b, 18c, 18d Nozzle 20 Pure water tanks 20a, 20b Nozzle 100 Pallet G Glass plate P slip paper

Claims (5)

A cleaning agent comprising a detergent inorganic alkaline containing the surfactant diluent is a 4 wt% concentration of the cleaning agent diluted with water to 3 wt%, KOH, NaOH, EDTA- 4Na, EDTA- _{4K, Na 4 P 2 O 7} , K 4 P 2 concentration of one or more alkali component selected from _{O 7} is formed by adding the alkaline component is from 0.5% to 0.2% by weight,
A cleaning solution for a color filter glass substrate , wherein the cleaning solution has a cloud point of 75 ° C. or higher . A cleaning solution having a cloud point determined by the concentration of the detergent and the concentration of the alkali component,
The detergent comprises an inorganic alkaline detergent containing a surfactant, and the concentration of the detergent is 3% by weight to 4% by weight ;
The alkali component comprises at least one alkali component selected from KOH, NaOH, EDTA-4Na, EDTA-4K, Na ₄ P ₂ O ₇ , and K ₄ P ₂ O ₇ ,
The cloud point is 75 ° C. or higher;
A cleaning solution for a glass substrate for a color filter, wherein a black matrix resin is formed on a surface of the substrate. The alkali component is KOH,
The addition of the KOH is such that the cloud point is at least 75 ° C.
The cleaning solution for a glass substrate for a color filter according to claim 1 or 2, wherein: A method for cleaning a glass substrate, comprising: a cleaning step of removing foreign substances adhered to the glass substrate using the cleaning solution for a glass substrate for a color filter according to any one of claims 1 to 3,
Before the washing step, the glass substrate is laminated with recycled paper sandwiched therebetween,
The foreign matter is an adhesive foreign matter derived from a substance contained in the recycled paper,
A method for cleaning a glass substrate for a color filter, comprising: In the cleaning step, the temperature of the cleaning liquid is higher than 60 ° C.
The method for cleaning a glass substrate for a color filter according to claim 4, wherein:

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