TWI609001B - Glass substrate for display and its manufacturing method - Google Patents

Description

Glass substrate for display and manufacturing method thereof

The present invention relates to a glass substrate for a display and a method of manufacturing the same.

In a flat panel display such as a plasma display panel (PDP), a liquid crystal display (LCD), an electroluminescence display (ELD), or a field emission display (FED), a substrate having a transparent electrode, a semiconductor element, or the like formed on a glass substrate is used. . For example, a substrate having a transparent electrode, a TFT (Thin Film Transistor), or the like formed on a glass substrate is used for the LCD.

The formation of the transparent electrode and the semiconductor element equal to the glass substrate is performed in a state where the glass substrate is fixed to the adsorption stage by vacuum suction.

However, the glass substrate is an insulator and is easily charged by contact or friction with a foreign substance, resulting in strong adhesion to the adsorption stage. Therefore, when the glass substrate on which the semiconductor element or the like is formed is peeled off from the adsorption stage, the glass substrate is hardly peeled off from the adsorption stage, and if it is intended to be forcibly peeled off, the glass substrate is broken.

Further, when peeling electrification occurs when the glass substrate is peeled off from the adsorption stage, electrostatic breakdown of a semiconductor element such as a TFT formed on the glass substrate occurs.

Therefore, the surface of the glass substrate contacting the side of the adsorption stage is roughened to reduce the contact area between the glass substrate and the adsorption stage. When the contact area between the glass substrate and the adsorption stage is reduced, the amount of charge of the glass substrate is reduced, and it is easy to peel off from the adsorption stage, and the amount of peeling charge is reduced.

As a method of roughening treatment, for example, it is known to contain a liquid and an abrasive grain. A method in which a slurry is blown onto one surface of a glass substrate and the surface of the glass substrate is polished by a brush (Patent Document 1).

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-343632

However, in the glass substrate which has been roughened by the prior method, the occurrence of peeling electrification when the glass substrate is peeled off from the adsorption stage is not sufficiently suppressed, and there is a case where electrostatic breakdown of the semiconductor element occurs. Further, the glass substrate which has been subjected to the roughening treatment is required to be further easily peeled off from the adsorption stage.

The present invention provides a glass substrate for a display which has a surface which is in contact with the side of the adsorption stage and which can sufficiently reduce the contact area with the adsorption stage, and a method for producing the same.

[1] A glass substrate for a display having one surface of fine particles attached to a glass substrate, and a roughness Ra of the one surface is 0.5 to 10 nm.

[2] The glass substrate for a display according to [1], wherein the fine particles have an average particle diameter of 50 nm or less.

[3] The glass substrate for a display according to [1] or [2] wherein the fine particles are those containing a metal oxide.

[4] The glass substrate for a display according to any one of [1] to [3] wherein the microparticles are one or two selected from the group consisting of cerium oxide microparticles, zirconia microparticles, cerium oxide microparticles, and alumina microparticles. The above.

[5] A method for producing a glass substrate for a display, comprising the method for producing a glass substrate for a display according to any one of [1] to [4], comprising: a coating step of coating a surface of the glass substrate a coating liquid containing fine particles; a washing step of rinsing the above one with pure water a portion of the above-mentioned fine particles on the surface; and a drying step of drying the glass substrate.

In the glass substrate for a display of the present invention, since the roughness Ra of one surface is 0.5 to 10 nm, the contact area with the adsorption stage can be sufficiently reduced by being disposed on the side contacting the adsorption stage. Therefore, the glass substrate for a display of the present invention can be easily peeled off when peeled off from the adsorption stage, and peeling electrification is hard to occur.

According to the method for producing a glass substrate for a display of the present invention, it is possible to produce a glass substrate for a display which has a surface which is in contact with the side of the adsorption stage and which can sufficiently reduce the contact area with the adsorption stage.

1‧‧‧ glass substrate for display

2‧‧‧ glass substrate

2a‧‧‧attached surface

2b‧‧‧ positive

3‧‧‧Microparticles

3a‧‧‧Microparticles

4‧‧‧ Coating solution

5‧‧‧ pure water

21‧‧‧ Back (one side)

41‧‧‧ Coating tank

42‧‧‧Application roller

Fig. 1 is a cross-sectional view showing an example of a glass substrate for a display of the present invention.

Fig. 2 is a view for explaining a method of manufacturing the glass substrate for a display shown in Fig. 1.

Fig. 3 is a view for explaining a method of manufacturing the glass substrate for a display shown in Fig. 1.

Fig. 4 is a cross-sectional view showing an example of a glass substrate used in the glass substrate for a display of the present invention.

5(a) to 5(c) are views for explaining another manufacturing method of the glass substrate for a display shown in Fig. 1.

<Glass substrate for display>

Fig. 1 is a cross-sectional view showing an example of a glass substrate for a display of the present invention. The glass substrate 1 for a display shown in FIG. 1 has a back surface 21 (one surface (upper surface in FIG. 1)) on which the fine particles 3 are adhered to the glass substrate 2.

The back surface 21 of the glass substrate 1 for a display is a surface that is placed in contact with the adsorption stage when a transparent electrode, a semiconductor element, or the like is formed on the glass substrate 1 for display.

On the other hand, the front surface 2b of the glass substrate 1 for a display (the surface on the opposite side to the one surface (the lower surface in FIG. 1)) forms a surface of a transparent electrode, a semiconductor element, or the like. As shown in Figure 1 The front surface 2b of the glass substrate 1 for display includes the front surface of the glass substrate 2. The front surface 2b of the glass substrate 1 for a display (the front surface of the glass substrate 2) is a smooth surface having a roughness Ra of about 0.2 to 0.4 nm.

The roughness Ra of the back surface 21 of the glass substrate 1 for a display shown in Fig. 1 is 0.5 to 10 nm, preferably 0.7 to 5 nm, more preferably 1 to 4 nm.

In the roughness Ra of the present invention, the arithmetic mean height defined by JIS B0601 (2001) is obtained by measuring the measurement area of 5 μm × 5 μm by an atomic force microscope, and the average value is calculated by obtaining the average value. When the measurement area of 5 μm × 5 μm is measured by an atomic force microscope, the "roughness" of the glass substrate 2 can be measured purely without considering the "unevenness" of the glass substrate 2.

When the roughness Ra of the back surface 21 is 0.5 nm or more, when a transparent electrode, a semiconductor element, or the like is formed on the front surface 2b of the glass substrate 1 for a display, the contact area between the back surface 21 and the adsorption stage is sufficiently small. As a result, the glass substrate 1 for display can be easily peeled off when peeled off from the adsorption stage, and peeling electrification is hard to occur. Further, when the roughness Ra of the back surface 21 is 10 nm or less, generation of scattering of visible light can be suppressed, and high transmittance of visible light can be maintained.

In the glass substrate 1 for a display shown in FIG. 1, the adhered surface 2a to which the fine particles 3 are adhered on the glass substrate 2 may be, for example, a flame-polished surface having a roughness Ra of about 0.2 nm, or as shown in FIG. It is a surface having a roughness Ra of about 0.4 nm which has been roughened.

The glass substrate 1 for display on which the surface to be adhered 2a is roughened is such that the contact area between the back surface 21 of the glass substrate 2 and the adsorption stage is further smaller. Therefore, when the glass substrate 1 for a display is peeled off from the adsorption stage, peeling can be performed more easily and the generation of peeling electrification can be suppressed more effectively.

Examples of the glass substrate 2 include an alkali-containing glass substrate such as a soda lime silicate glass substrate, and an alkali-free glass substrate such as a borosilicate glass substrate.

The shape and planar size of the glass substrate 2 are not particularly limited, and are rectangular and longitudinal. When the width is 100 to 3000 mm, it is preferable as a substrate for a display. Further, the thickness of the glass substrate 2 is preferably 0.1 to 3 mm, which is used as a substrate for a display.

In the case where the glass substrate 2 is an alkali-free glass substrate, the composition of the glass substrate 2 is, for example, expressed in mol%, and preferably includes SiO ₂ : 66 to 70%, Al ₂ O ₃ : 9 to 14%, and B ₂ O. ₃ : 6 to 9.5%, MgO: 1 to 5%, CaO: 1 to 6%, SrO: 2 to 8%, MgO + CaO + SrO: 9 to 16%, and substantially no BaO. Further, in the case where the glass substrate 2 is an alkali-free glass substrate, it is preferably a thickness of 0.3 to 1.0 mm.

The microparticles 3 preferably comprise a metal oxide. The fine particles 3 containing a metal oxide are preferably one selected from the group consisting of cerium oxide (CeO ₂ ) fine particles, zirconium oxide (ZrO ₂ ) fine particles, cerium oxide (SiO ₂ ) fine particles, and aluminum oxide (Al ₂ O ₃ ) fine particles. In the case of two or more types, it is particularly preferable to use cerium oxide microparticles from the viewpoint of adhesion due to a difference in surface potential.

The average particle diameter of the fine particles 3 is not particularly limited as long as it can form the back surface 21 having Ra of 0.5 to 10 nm, and is preferably 50 nm or less, more preferably 5 to 30 nm, still more preferably 10 to 20 nm.

In addition, the average particle diameter of the fine particles 3 is a converted value based on a specific surface area measured by a BET (Brunauer-Emmett-Teller) adsorption method (according to JIS Z8830, 1990 (the latest revised year 2013)).

When the average particle diameter of the fine particles 3 is 50 nm or less, when the fine particles 3 are adhered to the glass substrate 2 by using the coating liquid containing the fine particles, the fine particles 3 in the coating liquid are hardly precipitated, and the fine particles 3 can be favorably dispersed. In the coating liquid, the treatment of the coating liquid is easy, which is preferable. Further, when the average particle diameter of the fine particles 3 is 50 nm or less, the fine particles 3 which are washed in the cleaning step described below or which are detached after adhering to the glass substrate 2 do not affect the manufacturing steps of the display in the form of impurities.

<Manufacturing method>

Then, as an example of the method for producing a glass substrate for a display of the present invention, A method of manufacturing the glass substrate for a display shown in Fig. 1 will be described with reference to Figs. 2 and 3 .

In manufacturing the glass substrate 1 for a display shown in FIG. 1, first, the glass substrate 2 is prepared.

Then, as shown in FIG. 2, the coating liquid 4 containing the fine particles 3 is applied to the adherend surface 2a of the glass substrate 2 (the surface of the glass substrate 1 for a display which becomes the back surface 21) (coating step).

The fine particles 3 are supplied onto the adherend surface 2a of the glass substrate 2 by the coating step, and the fine particles 3 are caused by the adhesion caused by the difference in surface energy or surface potential of the glass substrate 2 and the fine particles 3. It adheres to the adhering surface 2a of the glass substrate 2.

The coating liquid 4 containing the fine particles 3 may be one in which the fine particles 3 are dispersed in water. The content of the fine particles 3 in the coating liquid can be appropriately determined depending on the density of the fine particles 3 on the back surface 21 of the glass substrate 1 for a display, the coating amount of the coating liquid 4, the viscosity of the coating liquid 4 which is easily applied, and the like. There is no special limit. In the coating liquid 4, an additive such as a pH adjuster such as nitric acid or a dielectric constant adjuster such as an alcohol may be contained as needed.

Further, as the coating liquid 4, a mixture of the fine particles 3 in a mixed solution of water and ethanol or a mixed solution of water and glycerin may be used.

The coating amount of the coating liquid 4 can be appropriately determined depending on the content of the fine particles 3 in the coating liquid, etc., and it is preferable that the Ra of the adhering surface 2a of the glass substrate 2 is 0.5 to 10 nm.

The coating method of the coating liquid 4 is not particularly limited, and a method in which the coating liquid 4 can be applied only to the side of the glass substrate 2 to be adhered to the surface 2a is preferable, and for example, the surface to which the glass substrate 2 is attached is exemplified. 2a is a method in which the coating liquid 4 is added to the upper side, a method in which the adhering surface 2a is directed downward, and a coating roller or a sprayer is used.

Then, as shown in FIG. 3, a washing step of rinsing a portion of the fine particles 3 on the adherend surface 2a with pure water 5 is performed. In the washing step, for example, a method in which the pure water 5 is supplied to the adherend surface 2a of the glass substrate 2 coated with the coating liquid 4 by using a nozzle can be used.

In this embodiment, even if the cleaning step is performed, as shown in FIG. The fine particles 3 adhering to the adherend surface 2a of the glass substrate 2 remain without being removed by the adhesion caused by the difference in surface energy or surface potential, and are only left on the adhered surface 2a of the glass substrate 2 The microparticles 3 are selectively removed.

In the present embodiment, the remaining fine particles 3 mean the fine particles 3a (3) which do not directly interact with the adhered surface 2a of the glass substrate 2.

Next, the glass substrate 2 in which the washing step has been completed is dried, and the pure water 5 used in the washing step is removed (drying step). The drying method is not particularly limited, and a blast drying method or the like can be used.

In the present embodiment, the remaining fine particles 3a (3) existing on the adherend surface 2a of the glass substrate 2 are removed by performing a washing step before the drying step. Therefore, in the drying step, the remaining fine particles 3a (3) which remain without adhering to the adherend surface 2a can be prevented from being folded onto the front surface 2b of the display glass substrate 1 and adhered to the front surface 2b of the display glass substrate 1. on.

Moreover, the fine particles 3 on the adherend surface 2a of the glass substrate 2 adhere to the adherend surface 2a by the adhesion due to the difference in surface energy or surface potential, and therefore it is difficult to remove even if the drying step is performed. Therefore, the fine particles 3 remain at a sufficient density on the adherend surface 2a after the drying step. Therefore, the roughness Ra of the back surface 21 of the glass substrate 1 for a display after the drying step is in the range of 0.5 to 10 nm. Moreover, since it is difficult to remove the fine particles 3 on the adhering surface 2a even if the drying step is performed, for example, a drying step can be performed by a method such as a blast drying method which can efficiently and easily dry.

By the above steps, the glass substrate 1 for a display shown in Fig. 1 can be obtained.

Thereafter, a transparent electrode, a semiconductor element, or the like is formed on the front surface 2b (the lower surface in FIG. 1) of the glass substrate 1 for a display shown in FIG. 1 obtained in this manner. The both sides of the glass substrate 1 for display cleaning may be washed before the transparent electrode, the semiconductor element, or the like is formed. In the glass substrate 1 for a display shown in FIG. 1, the fine particles 3 adhere to the adherend surface 2a of the glass substrate 2 by the adhesion due to the difference in surface energy or surface potential. Even if it is washed and washed, it is difficult to remove the fine particles 3. Therefore, even if a part of the fine particles 3 adhering to the adherend surface 2a is detached by washing and washing, a sufficient roughness Ra of about 1 nm can be secured on the back surface 21 of the glass substrate 1 for a display.

The method for producing the glass substrate for a display of the present invention is not limited to the above method. For example, the coating step, the washing step, and the drying step may be performed by using a manufacturing apparatus including a transport mechanism, for example, while transporting the glass substrate 2 at 80 to 1500 cm/min in the direction of the arrow shown in FIG. 5(a). .

The manufacturing apparatus used in the present embodiment includes, for example, a transport mechanism including a plurality of transport rollers (not shown). As the conveyance roller, for example, it is possible to arrange the glass substrate 2 so as to be vertically paired.

In the present embodiment, the glass substrate 2 is conveyed downward by the conveyance surface 2a by the conveyance mechanism.

As shown in Fig. 5 (a), the manufacturing apparatus used in the present embodiment includes an application mechanism having a coating liquid tank 41 disposed under the glass substrate 2 being conveyed, and coating. Roller 42. As shown in FIG. 5(a), the coating liquid 4 containing the fine particles 3 is added to the coating liquid tank 41. The coating roller 42 has a dimension in a direction orthogonal to the conveying direction of the glass substrate 2 longer than a width of the glass substrate 2 (a direction orthogonal to the conveying direction of the glass substrate 2). As shown in FIG. 5( a ), the application roller 42 rotates in the direction along the conveyance direction of the glass substrate 2 centering on the rotation axis extending in the direction orthogonal to the conveyance direction of the glass substrate 2 .

As shown in Fig. 5 (a), the lower surface of the coating roller 42 is in contact with the coating liquid 4 added to the coating liquid tank 41. The upper surface of the application roller 42 is disposed so as to be in contact with the adherend surface 2a of the glass substrate 2 that moves in the transport direction.

In the coating mechanism shown in FIG. 5( a ), the coating roller 42 that is in contact with the glass substrate 2 rotates in accordance with the movement of the glass substrate 2 to be conveyed, and the coating liquid 4 is supplied to the coating roller 42 . The upper surface contacts the movement of the glass substrate 2 on the adhered surface 2a. Thereby, the coating liquid 4 is applied to the adherend surface 2a of the glass substrate 2 (coating step).

The manufacturing apparatus used in the present embodiment includes a pure water supply mechanism that supplies pure water 5 to the upper and lower surfaces of the glass substrate 2 conveyed by the transport mechanism using a nozzle (not shown). In the pure water supply mechanism shown in FIG. 5(b), a plurality of nozzles are opposed to each other so as to sandwich the upper and lower surfaces of the glass substrate 2 to be conveyed.

In the present embodiment, the glass substrate 2 coated with the coating liquid 4 is transported by the transport mechanism, and as shown in FIG. 5(b), it passes through the region of the pure water supply mechanism that supplies the pure water 5. Thereby, a part of the fine particles 3 existing on the adhered surface 2a of the glass substrate 2 during conveyance is rinsed with the pure water 5 (washing step). In the present embodiment, as shown in FIG. 5(b), even if the cleaning step is performed, the fine particles 3 adhering to the adherend surface 2a of the glass substrate 2 by the adhesion due to the difference in surface energy or surface potential are observed. It is also left unremoved, so that only the remaining fine particles 3a (3) existing on the adherend surface 2a of the glass substrate 2 are selectively removed.

Further, in the pure water supply mechanism shown in Fig. 5 (b), in the washing step, not only the pure water 5 is supplied to the adhered surface 2a of the glass substrate 2 being conveyed, but also the pure water 5 is supplied to the front surface 2b. . Further, in the present embodiment, since the glass substrate 2 is conveyed downward by the adhering surface 2a, the remaining fine particles 3a (3) which are washed in the washing step are discharged downward. By this, in the present embodiment, the remaining fine particles 3a (3) which have not been attached to the adherend surface 2a which have been washed in the washing step are effectively prevented from adhering to the front surface 2b of the glass substrate 2.

The manufacturing apparatus used in the present embodiment includes a drying mechanism (not shown) that is disposed above and below the glass substrate 2, respectively. As the drying means, for example, an air knife that ejects air in a wall shape in a direction orthogonal to the conveying direction of the glass substrate 2 toward the glass substrate 2 is exemplified.

In the present embodiment, the glass substrate 2 that has been subjected to the cleaning step is transported by the transport mechanism, and is passed through a region where air is ejected from the air knife as the drying mechanism. Thereby, as shown in FIG. 5(c), the pure water 5 used in the washing step is removed from both surfaces of the glass substrate 2 during the transfer (drying step).

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by the examples.

"Example 1"

The glass substrate for a display of Example 1 was produced by the method shown below.

First, as a glass substrate, it is prepared to perform roughening treatment on both sides by performing the polishing by the floating method and cutting, and then performing the polishing for removing the unevenness and the removal of the residue after the polishing (Asahi Glass) The company manufactures: AN100, vertical 550mm × horizontal 440mm × thickness 0.7mm).

Then, 200 mL of the coating liquid containing the fine particles was dropped onto the adhered surface of the glass substrate (the surface on the side of the back surface of the glass substrate for display) so as to spread over the entire substrate (coating step).

As the coating liquid, CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) containing 20 to 21% by mass of cerium oxide fine particles having an average particle diameter of 8 to 12 nm is diluted with pure water to have a cerium oxide content of 0.01 mass. % of the solution.

Then, as shown in Fig. 3, a washing step of rinsing a portion of the fine particles on the adhered surface with pure water is performed. The washing step was carried out by supplying pure water to the adhered surface of the glass substrate at a flow rate of 2000 mL/min using a nozzle for 5 seconds.

Next, the glass substrate which has completed the washing step is dried by a blast drying method, and the pure water used in the washing step is removed (drying step).

The glass substrate for a display of Example 1 was obtained by the above steps.

The roughness Ra of the back surface of the glass substrate for a display of Example 1 was 2.78 nm.

"Example 2"

As the coating liquid, PL-1 (trade name: manufactured by Fuso Chemical Co., Ltd.) containing 12% by mass of cerium oxide fine particles having an average particle diameter of 15 nm is diluted with pure water to have a cerium oxide content of 0.01% by mass. The same solution as in Example 1 except the solution In the formula, the glass substrate for a display of Example 2 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 2 was 5.37 nm.

"Example 3"

As the coating liquid, COMPOL 20 (trade name: manufactured by Fujimi Incorporated) containing 40% by mass of cerium oxide fine particles having an average particle diameter of 15 nm was used, and the cerium oxide content was 0.01% by mass. A glass substrate for a display of Example 3 was obtained in the same manner as in Example 1 except for the solution.

The roughness Ra of the back surface of the glass substrate for a display of Example 3 was 1.22 nm.

"Example 4"

In the same manner as in Example 1, except that a solution obtained by diluting CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) with pure water and having a cerium oxide content of 0.1% by mass was used as the coating liquid. The glass substrate for a display of Example 4 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 4 was 4.29 nm.

"Example 5"

In the same manner as in Example 1, except that a solution obtained by diluting CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) with pure water and having a cerium oxide content of 0.001% by mass was used. A glass substrate for a display of Example 5 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 5 was 1.16 nm.

"Example 6"

The glass substrate is prepared by a floating method and the surface to be adhered is a flame-polished surface (manufactured by Asahi Glass Co., Ltd.: AN100, 550 mm in length × 440 mm in width × 0.7 mm in thickness), and in addition to Example 1, In the same manner, the glass substrate for a display of Example 6 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 6 was 2.19 nm.

"Example 7"

As a coating liquid, CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) is used. The glass substrate for a display of Example 7 was obtained in the same manner as in Example 6 except that the pure water was diluted to have a cerium oxide content of 0.001% by mass.

The roughness Ra of the back surface of the glass substrate for a display of Example 7 was 1.47 nm.

"Embodiment 8"

The back surface of the glass substrate of Ra=2.78 nm prepared in Example 1 was washed with water of 2000 mL/min for 5 seconds to obtain a glass substrate for a display of Example 8.

The roughness Ra of the back surface of the glass substrate for a display of Example 8 was 2.46 nm.

"Example 9"

The back surface of the glass substrate of Ra=2.19 nm prepared in Example 6 was washed with water of 2000 mL/min for 5 seconds to obtain a glass substrate for a display of Example 9.

The roughness Ra of the back surface of the glass substrate for a display of Example 9 was 0.96 nm.

"Embodiment 10"

As a coating liquid, a solution obtained by diluting a solution of CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) in a ratio of 1/1 (by weight) of pure water/ethanol to a cerium oxide content of 0.01% by mass is used. A glass substrate for a display of Example 10 was obtained in the same manner as in Example 6 except the above.

The roughness Ra of the back surface of the glass substrate for a display of Example 10 was 2.94 nm.

"Example 11"

As a coating liquid, a solution obtained by diluting a solution of CE-20A (trade name: manufactured by Nissan Chemical Co., Ltd.) in a ratio of 1/1 (by weight) of pure water/glycerin to a cerium oxide content of 0.01% by mass is used. A glass substrate for a display of Example 11 was obtained in the same manner as in Example 6 except the above.

The roughness Ra of the back surface of the glass substrate for a display of Example 11 was 2.56 nm.

"Embodiment 12"

In the same manner as in Example 6, except that a solution of the Snowtex AK (trade name: manufactured by Nissan Chemical Co., Ltd.) was diluted with pure water to have a cationic cerium oxide content of 0.01% by mass. In the manner described above, the glass substrate for a display of Example 12 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 12 was 2.16 nm.

"Example 13"

As a coating liquid, a solution obtained by diluting ultrafine zirconia sol #1 (trade name: manufactured by Nissan Chemical Co., Ltd.) with pure water to have a zirconia content of 0.01% by mass is used, and other examples are used. In the same manner, the glass substrate for a display of Example 13 was obtained.

The roughness Ra of the back surface of the glass substrate for a display of Example 13 was 1.57 nm.

"Comparative Example 1"

The glass substrate for a display of Comparative Example 1 was produced by the method shown below.

The glass substrate before the coating step prepared in Example 6 was used as the glass substrate for a display of Comparative Example 1.

The roughness Ra of the back surface of the glass substrate for a display of Comparative Example 1 was 0.20 nm.

Then, the peeling charge amount of the glass substrate for a display of Example 6 and Comparative Example 1 was evaluated by the method shown below.

(peeling charge)

The glass substrate for the display was vacuum-adsorbed on the adsorption stage for a certain period of time, and then peeled off using the jacking pin. The voltage between the glass substrate and the adsorption stage caused by the charging generated from the peeling of the adsorption stage was measured every time.

If it is set to Q: the amount of charge, d: the distance between the glass substrate and the adsorption stage, S: the area of the glass substrate, and ε: the dielectric constant in the atmosphere, the voltage between the glass substrate and the adsorption stage due to charging (V) ) is represented by the following formula (1).

V=dQ/εS (1)

The distance d between the glass substrate and the adsorption stage is represented by the product of the rising speed v of the jacking pin and the time t. Therefore, the formula (1) is represented by the following formula (2).

V= v tQ/εS (2)

If the equation (2) is time-differentiated, the following equation (3) can be obtained.

dV/dt= v Q/εS (3)

Equation (3) indicates that the slope of the data obtained by the measurement is proportional to the amount of charge. The charge amount Q is reduced by the passage of time, so the maximum value of the slope of the peeling moment is the peeling charge amount.

The peeling tape amount calculated in this manner was set to "1" in Comparative Example 1, and Example 6 was "0.66" which was lower.

"Comparative Example 2"

The glass substrate for a display of Comparative Example 2 was produced by the method shown below.

The glass substrate before the coating step prepared in Example 6 was treated by brush rubbing on the polishing liquid containing the polishing material described in Patent Document 1, and the comparative example 2 was prepared. A glass substrate for the display.

The roughness Ra of the back surface of the glass substrate for a display of Comparative Example 2 was 0.42 nm.

Then, the peeling charges of the glass substrates for displays of Example 11 and Comparative Example 2 were evaluated.

The calculated peeling tape amount was set to "1" in Comparative Example 2, and Example 11 was "0.64" which was lower.

The present invention has been described in detail with reference to the specific embodiments thereof, and it is understood that various changes or modifications may be added without departing from the spirit and scope of the invention.

The present application is based on Japanese Patent Application No. 2012-198825, filed on Sep. 2010, the content of

Industrial availability

The glass substrate for a display of the present invention is used as a PDP, LCD, ELD, FED, etc. Useful for the substrate of the display.

1‧‧‧ glass substrate for display

2‧‧‧ glass substrate

2a‧‧‧attached surface

2b‧‧‧ positive

3‧‧‧Microparticles

21‧‧‧ Back (one side)

Claims (7)

A glass substrate for a display having a surface on which a fine particle is adhered to a glass substrate, wherein the fine particle adheres to the one surface by adhesion due to a difference in surface energy or surface potential of the glass substrate, and the one surface The roughness Ra is 0.5 to 10 nm. The glass substrate for a display according to claim 1, wherein the fine particles have an average particle diameter of 50 nm or less. The glass substrate for a display according to claim 1, wherein the fine particles have an average particle diameter of 5 to 30 nm or less. The glass substrate for a display according to any one of claims 1 to 3, wherein the fine particles are those containing a metal oxide. The glass substrate for a display according to any one of claims 1 to 3, wherein the fine particles are one or more selected from the group consisting of cerium oxide fine particles, zirconia fine particles, cerium oxide fine particles, and alumina fine particles. The glass substrate for a display according to claim 4, wherein the fine particles are one or more selected from the group consisting of cerium oxide fine particles, zirconia fine particles, cerium oxide fine particles, and alumina fine particles. A method for producing a glass substrate for a display, comprising the method for producing a glass substrate for a display according to any one of claims 1 to 6, further comprising: a coating step of applying a coating containing fine particles on one side of the glass substrate a cloth liquid; a washing step of rinsing a portion of the fine particles on the one side with pure water; and a drying step of drying the glass substrate.