TW200811068A - Process for producing alkali-free glass substrate - Google Patents

Abstract

A process for producing an alkali-free glass substrate in which a protective coating film capable of being easily removed in a cleaning step is efficiently formed and the back side of the glass substrate is inhibited from being marred while reducing the amount of sulfur dioxide to be used; and an alkali-free glass substrate obtained by the process. The process for alkali-free glass substrate production produces an alkali-free glass substrate by the float method. It comprises a forming step in which a molten glass is formed on molten tin into a glass substrate and an annealing step in which the glass substrate formed in the forming step is annealed. The process further comprises a first supply step in which an inorganic substance containing an alkali metal is blown against that surface of the glass substrate which was in contact with the molten tin and a second supply step in which after the first supply step, SO2 gas is blown against that surface of the glass substrate which was in contact with the molten tin.

Description

200811068 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a method for producing an alkali-free glass substrate. [Prior Art] Most of the glass substrates typified by glass substrates for displays are produced by a fouling method or a melting method. The floating method differs from the melting method in that it is known for its ability to efficiently manufacture large-area glass substrates. The floating method generally includes a forming step of forming molten glass on a molten tin in a molten tin bath into a glass substrate, and a step of cooling to freeze the glass substrate formed by the forming step. However, since the glass substrate formed by the forming step is taken out from the molten tin bath and then conveyed by the drum, there is a flaw in the back surface of the glass substrate (touching the surface of the drum) during the transfer, resulting in the quality of the glass substrate. The problem of decline. Therefore, in order to prevent the flaw on the back surface of the glass substrate which is generated during the conveyance, it is known to spray sulfur dioxide (s〇2 gas) onto the back surface of the glass substrate to form an alkali metal present in the glass (for example, Sodium or the like is reacted to form sodium sulfate on the back surface of the glass substrate, and it acts as a protective film to prevent the occurrence of scratches (for example, refer to Patent Document 1 and Non-Patent Document 1). [Patent Document 1] International Publication No. 2002/05 1767 pamphlet [Non-Patent Document 1] U· Senturk etc, J. Non-Cryst· Solids, Vol. 222, p. 160 (1997) [Summary of the Invention] 122464.doc 200811068 [Problem to be solved by the invention] However, in order to achieve the high damage resistance required for high-quality displays in recent years: j, the thickness of the protective film must be further increased, and for this reason, a large amount of oxidation & The problem of deterioration of load and working environment. Since sulfur monoxide is a highly corrosive gas, there is also a problem that the corrosion σ side furnace material shortens the life of the furnace material. In particular, in the case of manufacturing a glass substrate comprising a glass (which is also referred to as a non-ceramic glass) which does not actually contain an alkali metal, the method of spraying sulfur dioxide does not produce sodium sulfate in the glass substrate. , ^, ι The reaction product of the genus Monsium is sulfuric acid #5 and sulfuric acid. These salts obtained from the soil-based metal function as a film for preventing scratches on the glass substrate, but the production efficiency is remarkably lower than that of sodium sulfate, and thus the effect may not be sufficient. Further, even if yttrium is formed, it is a water-soluble salt, and there is a problem that it is extremely difficult to remove it in the subsequent "cleaning step". Further, although these salts can be removed by polishing, in order to obtain a glass substrate having a smoothness, it is necessary to honing a considerable thickness, so that there is a problem in that the manufacturing time and the manufacturing cost increase. In addition, if a high-quality surface such as an alkali-free glass-based flat panel display is required, if there is a flaw on the glass substrate, problems such as poor disconnection may occur, and even if it is used as a window glass or an automobile glass, even smaller. Scars can also be a problem. Therefore, an object of the present invention is to provide a method for producing an alkali-free glass substrate and a glass-free substrate obtained by the method, and the method for manufacturing a glass substrate is manufactured for use in a liquid crystal display. The glass substrate without glass (hereinafter also referred to as "no glass substrate") can effectively form a protective film that can be easily removed in the cleaning step, thereby achieving a reduction in the amount of sulfur dioxide used and suppressing the glass. The occurrence of scratches on the back side of the substrate. [Technical means for solving the problem] In order to achieve the above-mentioned object, the present inventors have found that in the manufacturing step using the foreign method, the inorganic substance containing the metal is brought into contact with the molten tin on the glass substrate. The surface is sprayed, and an alkali metal is supplied, and then s〇2 gas is sprayed onto the surface to form a protective film which can be easily removed in the washing step, thereby achieving a reduction in the amount of sulfur dioxide used, and suppressing the glass substrate. The creation of a scar on the back side completes the present invention. That is, the present invention provides the following (1) to (14). (1) A method for producing an alkali-free glass substrate, which comprises producing a glass-free substrate by a floating method; comprising: forming a molten glass on a molten tin to form a glass substrate; and a step of cooling The glass substrate formed by the forming step is cooled; and the first supply step is performed, and an inorganic substance containing an alkali metal is sprayed onto a surface of the glass substrate on the side in contact with the molten tin; and a second supply step In the above! After the supply step, s〇2 gas is sprayed onto the surface of the glass substrate on the side in contact with the molten tin. (2) The method for producing an alkali-free glass substrate according to (1) above, wherein the supplying step of the above-mentioned 122464.doc 200811068 is carried out between the forming step and the step of quenching. (3) The method for producing an alkali-free glass substrate according to the above (1), wherein the first supply step is performed at a temperature within a range of ±100 ° C of a glass transition point of the glass substrate. (4) The method for producing a glass-free substrate according to (1) above, wherein the first supply step is performed at 600 to 800 °C. (5) The method for producing an alkali-free glass substrate according to any one of the above (1) to (4) wherein the second supply step is performed between the forming step and the step of cooling. (6) The method for producing an alkali-free glass substrate according to any one of the above (1) to (4) wherein the second supply step is at a temperature within a range of 100 ° C of a glass transition point of the glass substrate Implementation. (7) The method for producing an alkali-free glass substrate according to any one of the above (1) to (4) wherein the second supply step is carried out at 6 〇〇 to 800 °C. (8) A method for producing an alkali-free glass substrate, which is a method for producing an alkali-free glass substrate by a floating method; and comprising: forming a molten glass on a molten tin to form a glass substrate; In the first supply step, an inorganic metal containing an alkali metal is sprayed onto the surface of the glass substrate on the side in contact with the molten tin at 600 to 80 (rc), and a second supply step is performed after the first supply step. The SO 2 gas is sprayed onto the surface of the glass substrate on the side in contact with the molten tin at 600 800 C. (9) The manufacturer of the glass-free substrate according to any one of the above (1) to (8) 122464.doc 200811068 The method of producing an alkali-free glass substrate according to any one of the above (1) to (9), wherein the alkali metal-containing inorganic substance contains sodium and (11) The method for producing an alkali-free glass substrate according to the above (10), wherein the metal-containing inorganic substance is sodium tetraborate. (12) A non-inspective glass substrate using the above-mentioned lanthanum Or (11) manufacturing method Maker. (13) An alkali-free glass substrate produced by the method of (10) or (11) above, wherein the glass substrate is expressed by mass percentage based on an oxide, and comprises:

Si〇2: 30~85%, A1203: 〇~35%, B203: 0~35%,

MgO : 〇~350/〇, , Ca〇 : 〇~35%,

Sr〇 : 〇~3 5%,

Ba〇: 〇~35%, 'alkali metal component: 0.5% or less, the average butterfly/length of the surface of the glass substrate on the side in contact with the molten tin is 4 to 10 atom%, and boron is applied to the glass substrate The internal diffusion depth is above 5 nm. (14) An alkali-free glass substrate which is expressed in terms of mass percentage based on an oxide and contains: 122464.doc -10- 200811068

Si02: 30~85%, AI2O3 ··0~35%, B2〇3: 0~35%, MgO: 〇~35%,

CaO · 〇 ~35%, S r Ο · 〇 ~35%,

BaO : 〇~35%,

Metal composition: 〇·5% or less, the rot concentration is 4~1〇 atom% 5 nm or more. And the diffusion depth of boron from the average surface of the at least one surface to the inside is [effect of the invention]. According to the present invention, a method for producing an alkali-free glass substrate and a method for obtaining the same using the method can be provided. In the glass substrate, the method for producing the glass-free substrate is effective to form a film to be removed which can be easily removed in the cleaning step, thereby achieving a reduction in the amount of sulfur dioxide used, and suppressing the occurrence of scratches on the back surface of the glass substrate. [Embodiment] Hereinafter, the present invention will be described in detail. A method for producing an alkali-free glass substrate according to a first aspect of the present invention (hereinafter also referred to as "the production method of the present invention") is a method for producing an alkali-free glass substrate by using a floating method to produce an alkali-free glass substrate; The molding step includes molding the molten glass on the molten tin to form a glass substrate, and the step of cooling to freeze the glass substrate formed by the molding step, and the method of 122464.doc -11 - 200811068 The surface on the side where the molten tin is in contact with each other, that is, the bottom surface to which the inorganic substance is sprayed is sprayed with the so2 gas. In the first supply step, the surface of the glass substrate on the side in contact with the glazed tin (hereinafter also referred to as "bottom surface") is sprayed with an inorganic substance containing a metal (hereinafter also referred to as "alkali-containing metal" An inorganic substance"); and a second supply step, after the ith supply step, to the glass substrate

Moreover, it is preferable that the production method of the present invention further includes a washing step of removing the above-mentioned protective film. Next, the molding step, the cold cooling step, the first supply step, and the second supply step of the production method of the present invention will be described in detail, and a net step is provided as needed. [Molding step] The above-described forming step is a step of forming molten glass on molten tin in a molten tin bath into a glass substrate, which is a previously known step in the usual floating method. Fig. 1 is a conceptual view showing an example of a glass manufacturing line using a floating method. As shown in Fig. 1, in the floating method, first, molten glass* is continuously flowed from the melting kiln 3 to the molten tin bath on the molten tin bath 2 filled with molten tin to form a glass rib. Next, the glass ribbon is advanced while floating along the bath surface of the molten tin bath 2, whereby the temperature is lowered and the glass ribbon is formed into a plate shape, and then the glass substrate which is formed into a plate shape is guided by the guide roller 5. It is conveyed to the quenching furnace 6 in a state of being continuous in the longitudinal direction. Here, in Fig. 1, the forming step is a step of forming the molten glass 4 through the glass π until it is formed into a plate shape. 122464.doc -12 - 200811068 In the present invention, with the usual float MM m ^ fly into 4 as a molten tin bath 2, using a tin bath furnace including a special green material covering the inside of the metal box and a ceiling for A sealed structure that prevents oxidation of tin. As the ambient gas in the molten tin bath, a mixed gas containing hydrogen and nitrogen (hydrogen content of 2 to 10% by volume) can be used. The temperature condition in the molten tin bath of the above forming step is the same as that of the usual floating method, and is 60 (one) 〇 5 (rc, that is, it can be poured into the dazzling tin bath.

The temperature of the molten glass is set to 9 〇〇 to 1 〇 5 于 on the upstream side and 600 to 800 on the downstream side. . . Further, the temperature is usually maintained by the heat of the molten glass, and a heater or a cooler may be used for adjusting the temperature. In the production method of the present invention, the glass substrate having no glass is formed on the molten tin by the above-described forming step. Here, the alkali-free glass means a glass which does not substantially contain an alkali metal as described above. Specifically, in the present invention, the alkali-free glass is expressed in terms of an oxide based on an oxide and contains:

Si02: 30~85%, A1203: 〇~35%, B2〇3: 〇~35%,

MgO : 〇~35%, CaO : 〇~35%,

SrO ·· 0~3 5%, BaO : 〇~35%, metal composition: 0 · 5 % or less. In addition, the "two alkali metal components" means whether or not the following is implemented! 122464.doc -13- 200811068 The alkali metal component must be contained in the supply step. [Xu cold step] The above-mentioned Xu cold step (four) steps to cool the substrate of the upper material step. Here, in the above-mentioned glass, the above-mentioned "cold cooling step system" is carried out from the guide glass 5 from the guiding view 5 until it is transported to the quenching furnace 6 in the longitudinal direction. The steps of Xu Leng. With

In the present invention, as the quenching furnace, the same as the conventionally used quenching furnace, and a heater or the like may be provided in order to control the temperature. Moreover, the cold-cooling condition of the above-mentioned cold cooling furnace is the same as that of the normal floating method. The temperature at the inlet of the cold furnace can be set to 550 to 75 (rc, and the temperature at the outlet is set to 200 to 300 c. The speed can be set to 90 ° C ± 10 ° C / m. [First supply step] The first supply step is a step of supplying an alkali metal to the bottom surface by spraying 3 alkali metal inorganic substances onto the bottom surface of the glass substrate. Here, the term "metal-containing inorganic substance" as used herein means an inorganic substance containing a metal, for example, an inorganic substance containing lithium sodium (tetra), etc., which belongs to the above-mentioned glass by using the above-mentioned alkali metal-containing inorganic substance. The bottom surface of the substrate is supplied with the metal, and then the gas s〇2 is sprayed, and the protective film containing the alkali salt of sulfuric acid can be effectively formed. X, the protective film can be easily speared in the washing step. Further, since even the S is reduced The amount of 〇2 gas can also obtain the same protective effect. Therefore, the use of sulfur dioxide can be reduced, and the occurrence of scratches on the back surface of the glass substrate can be considered as the cause. The s〇2 body sprayed by the second supply step described below preferentially reacts with the alkali metal supplied to the bottom surface, and the s〇2 gas and the glass are also poorly water-soluble. (4)) The reaction ^ to inhibition. X 'by spraying the so-called alkali metal-containing inorganic substance from the outside: metal source, can be used together to obtain the opposite of S02 gas and alkaline earth metal: sex organisms (calcium sulfate, barium sulfate) In the S〇2 gas having a small amount of 802 gas, which is a protective film, the same protective effect is obtained. Specific examples of the inorganic substance containing Na include NaOH, Na2S, NaCl, NaF, NaBr, and the like. Guan, soda^, NaNH2, sodium f ether, NaBH4, NaCN, fine 〇3, Nw~ Cong (1) (sodium tetraborate decahydrate), such as 21〇7, etc., these may be used alone or in combination In particular, as the inorganic substance containing K, for example, KOH, KC1, KF, KBr, KI, KCN, K2C〇3, potassium gluconate, KHF2, KN〇3, K2B4 (V4H2〇 ( Potassium tetraborate tetrahydrate), 22 hawthorn 7, KBh, etc., these may be used alone or in combination Two or more types. As the inorganic substance containing Cs, for example, for example,

Cs0H, CsC1, CSF, CsBr, CsI, acetophenone, acid etch, HC 〇 2CS 'CsNC) 3, etc. These may be used alone or in combination of two or more. The alkali metal-containing inorganic substance contains an inorganic substance of Na, and the rate of the formation of the protective film (sodium sulphate) formed in the second supply step described below can be further increased, thereby making it easier to remove the water. it is good. Among them, an inorganic substance containing a metal and an inorganic substance containing Na and boron is more preferable because the alkali-free glass substrate obtained by the production method of the present invention further has abrasion resistance after the following washing step. . Specifically, it is preferably Na2B407-l〇H2〇, Na2B4〇7, and more preferably Na2B4〇7-10H2O ° by spraying an inorganic substance containing Na and boron, not only supply but also supply

Boron', as a result, the shed diffused from the bottom surface to the inside of the glass substrate, and the strength of the glass substrate itself was improved. Therefore, in addition to the money glass substrate, for example, a microplate for a Wei wafer, a biochip, a glass substrate, or the like can be used to satisfy a high degree of scratch resistance by utilizing the diffusion of boron.

In the first supply step, the first supply step is performed by spraying the alkali metal-containing inorganic substance onto the bottom surface of the glass substrate, and spraying W n± , ° "the bottom surface is supplied with a gold test lip, and the sample is taken. The following description can be suitably exemplified by the above-mentioned step of attaching the alkali metal-containing helmet, and if If # #", the time of the shell is earlier than the second supply described below, and the following It is preferable to be able to enter the VD between the above-mentioned forming step and the step of cooling, but it is preferable to the forming step and the above-mentioned forming step. The production of the flaw on the back surface of the glass substrate is the same as the above-mentioned forming step, for example, in the middle of the forming step, for example, the formation of the 驴t: is included in the forming step In the case of a molten tin bath (froat bath, float 122464.doc 16 200811068 cold) and the exit portion of the furnace as a whole (shieM rare, unshielded), it can be sprayed at the unshielded place. Further, the term "concurrent with the cold step" means that it can be sprayed near the inlet of the cold furnace or the upstream side of the cold furnace. Further, it is to be noted that "between the above-described forming step and the above-mentioned cold-cold step" means that the glass substrate may be sprayed while the glass substrate is being conveyed between the forming furnace and the quenching furnace. On the other hand, for example, a method of spraying the alkali metal-containing inorganic substance may be exemplified by heating the alkali metal-containing inorganic substance and vaporizing it, and spraying the vaporized substance to the bottom of the glass substrate using a nozzle. And a method of heating and vaporizing the metal-containing inorganic substance by heating by a heater, heating by an infrared lamp, laser heating, or the like. Further, it is preferred that the singulation of the octagonal substance is carried out at a temperature in the range of 100 ° C of the glass transition point of the glass substrate. Particularly preferred is a glass transition point of the glass substrate of -30 ° c ~ glass transition point +1 〇 (rc range) because the glass will be softened at the glass transition point if sprayed in this temperature range. Therefore, a film is formed in the region, whereby the generation of the flaw can be more effectively prevented. Specifically, in terms of effectively vaporizing the vaporized substance and spraying the surface of the glass substrate, the temperature of the substrate is not drastically lowered. Preferably, it is carried out at 600 to 800 ° C. Further, the amount of the vaporized material to be sprayed is preferably OH 〇 L / m 2 , more preferably 0.2 to 3 L / m 2 , particularly preferably o. hj L /m2. If the amount of the spray is within the range, the amount of the S〇2 gas to be sprayed can be suppressed, and the supply amount of the alkali metal supplied to the bottom surface of the glass substrate can be sufficiently increased, thereby further increasing with 122464.doc - The protection of 17-200811068 is formed by the reaction of the s〇2 gas sprayed in the second supply step described below to form a film. The use of sodium hypohydrate is used as the above-mentioned metal-containing inorganic substance. The following methods and the like are listed as preferred embodiments: in the glass base

In the furnace other than the furnace and the cold furnace (for example, the large 5L e furnace in the embodiment), the vaporized substance is sprayed by using a nozzle at a temperature of about 85 rc. The bottom surface of the glass substrate which is about 7 oz. or the bottom surface of the glass substrate conveyed between the k. The metal-containing inorganic substance is sprayed by the above method, and the metal is supplied to the bottom surface of the glass substrate. The presence of the metal on the bottom surface of the glass substrate can be confirmed by X-ray photoelectron spectroscopy (xps. · 叩 叩 〇 〇 〇 n n n n n n 或 或 或 或 或 或 或 或 或 或 或 或 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The second supply step is a step of applying a s〇2 gas to the bottom surface of the glass substrate to which the alkali metal is supplied after the first supply step, and forming a protective film on the bottom surface. (2) The step of forming a protective film on the bottom surface of the glass substrate to which the alkali metal is supplied is different from the previously known steps of the usual floating method. That is, the second supply step is The 8 〇 2 gas is sprayed onto the bottom surface of the glass substrate to which the alkali metal is supplied by the first supply step, and the alkali metal is reacted with the S 〇 2 gas to form an alkali sulfate-containing salt on the bottom surface of the glass substrate ( For example, a protective film of sodium sulfate or the like. 122464.doc 18 200811068 The spraying time (timing) and the spraying method of the kiss gas in the second supply step described above can be appropriately exemplified as follows. If the time of the gas is later than the above-mentioned mth step, there is no particular limitation of the home, but it is considered to be caused by the occurrence of the flaw on the surface of the glass substrate during the transfer process. Preferably, in the above-mentioned forming (4) and the above-mentioned cold-cold step, if the respective gases are simultaneously sprayed, it is difficult to form a film due to a reaction between the gases, and thus it is not preferable. The method of the 〇2 gas can be carried out by the same method as the conventionally known method of the usual floating method. Specifically, for example, a nozzle disposed under the glass substrate can be used for the glass. The method of spraying in the width direction of the sheet (for example, the method disclosed in the above-mentioned Patent Document No. 12, etc.) is carried out. In the present invention, the sulfate obtained from the soil of the soil is used. (for example, calcium sulfate or the like) as compared with the prior art of the protective film of the alkali-free glass substrate, on the one hand, it is possible to ensure the same protective effect, and on the other hand, it is possible to reduce the spray of gas 1. The reason is that, as described above, The S 〇 2 gas sprayed by the second supply and/or the reaction is preferentially reacted with the alkali metal supplied to the bottom surface to make the S 〇 2 gas and the alkali-free metal which is also less reactive in the alkali-free glass. The reaction of (Ca, Sr, etc.) is suppressed. Specifically, in the present invention, the amount of 'S〇2 gas sprayed can be reduced to 0_05 to 2.5 L/m2, especially to 0.05 to 0.3 L/m2. Further, it is preferred that the S〇2 gas is sprayed at a temperature within a range of ±10〇c of the glass transition point of the glass substrate. The reason for this is that since the glass is softened at 122464.doc -19-200811068, the protective film is formed in this region, whereby the occurrence of damage can be more effectively prevented. Specifically, the spraying of the so2 gas is more preferably 600 to 8 Torr. (The reason is as follows: if the spraying is carried out at this temperature, the protective film containing the sulfate which can be easily removed in the washing step can be efficiently produced, thereby further suppressing the flaw on the back surface of the glass substrate. [Washing Step] _ The above-described washing step which is carried out as desired is a step of washing and removing the protective film formed by the above-described second supplying step, which is a previously known step of the usual floating method. The time (sequence) and the washing method of the washing step can be appropriately exemplified as follows. If the time of the washing step is later than the second supplying step, there is no special limitation but due to the protective film. It is provided for the flaw generated on the surface (bottom surface) of the glass substrate during the drum conveyance process, and therefore it is preferably followed by the above-mentioned cold step of the final step (4) of the above-mentioned cold cooling step. The cleaning method of the above-described washing step is protected by a sulfate salt (for example, a water-containing salt such as sodium sulfate) which is obtained from an alkali metal in the present invention. The membrane can be removed by an easy method, for example, and can be removed by a water washing treatment. Further, when the first supply step is not performed, the s〇2 gas is sprayed, and the temple is formed in the glass. (1) The protective film on the bottom surface of the substrate becomes a sulfate derived from an alkaline earth metal (for example, a poorly water-soluble salt such as 'calcium sulfate), and thus becomes difficult to easily 122464.doc 200811068 in the manufacturing method of the present invention, In order to improve the smoothness of the obtained alkali-free glass substrate, reduce the deformation, splay, micro-corrugation, and flaws or foreign matter defects of the glass substrate, and obtain a surface quality with high uniformity, after the above-mentioned washing step, A grinding step is required as needed. 'The grinding step is a previously well-known step of the usual floating method. For the side grinding method, specifically, it is exemplified by using a cerium oxide-based abrasive to be ground in a foaming amine group. Method for producing a glass substrate on an acid ester. The method for producing an alkali-free glass substrate according to a second aspect of the present invention is a method for producing an alkali-free glass substrate by a floating method. In the production of the glass substrate, the molding step is carried out, and the molten glass is formed on the molten tin to form a glass substrate. The first supply step is performed at 6 to 80 (rC to the side of the glass substrate in contact with the molten tin). Surface sprayed with an inorganic substance containing an alkali metal

丨 今 今 today, slave κ music 1 evil sample explained the same. Further, in the second aspect of the invention, it is preferable that the cleaning step is provided, and the polishing step may be further provided.

The glass substrate is obtained by the production method of the present invention when the inorganic material containing 122464.doc 200811068 containing Na and boron is used in the production of the present invention. Specifically, an alkali-free glass substrate can be provided by subjecting the inorganic substance containing Na and boron to the bottom surface of the glass substrate in the above-mentioned second co-feeding step, and then performing the above-described cleaning step as needed. The alkali-free glass substrate of the present invention preferably has the following composition. That is, in the alkali-free glass substrate of the present invention, the glass substrate is expressed by mass percentage based on the oxide, and contains:

Si02: 30~85%,

Al2〇3 : 〇~35%, B2O3: 〇~35%,

MgO : 〇~3 5%,

CaO.O ~35%,

SrO : 〇~35%,

BaO: 0 to 35%, metal component: 0. 5 % or less, and the average boron concentration of the bottom surface of the glass substrate is 4 to 1 atom%, and the diffusion depth of boron to the inside of the glass substrate is 5 nm. the above. Here, the content ratio of Si〇2 (expressed as an oxide and expressed by mass percentage) is preferably 50 to 8 p%, more preferably 5 to 75%, and even more preferably 56 to 66%. Especially good is 58~60%. Further, the content ratio of 'Al2〇3 (in terms of oxides and expressed by mass percentage) is preferably (1) 0%, more preferably 3 to 22%, and even more preferably 3 to 20% 'especially good 15~2G% 'The best is again, the content of B2〇3 (based on oxides [in terms of mass percentage table 122464.doc -22- 200811068) is better 〇~30%, better 〇~15%, better is 5~12%. Further, the content of Mg ( (expressed on the basis of oxide and expressed by mass percentage) is preferably 〇 20%, more preferably 〇 8%, and even more preferably 0-6% ° / again, The content of CaO (based on oxides and expressed in mass percentages) is preferably 0 to 2%, more preferably 〇 to 9%, and even more preferably 0 to 8%. The content ratio of Sr0 (expressed on the basis of oxide and expressed by mass percentage) is preferably 〇20%, more preferably 〇12.5%, and still more preferably 3~12_5%. Further, the content ratio of BaO (expressed on the basis of oxide and expressed by mass percentage) is preferably 〇20. /. More preferably, 〇% or more and less than 2%. Further, the content ratio of the alkali metal component (expressed as an oxide based on the mass percentage) is preferably 0.5% or less, more preferably 〇2% or less, still more preferably 0.1% or less. ❿ Here, Si〇2, A1203, b2〇3, MgQ,

The content of CaO, SrO, BaO and an alkali metal component is as described above, and is within the range of the composition of the alkali-free glass used in the alkali-free glass substrate. In the present invention, the average boron concentration of the bottom surface of the glass substrate can be determined as an average value at the time of arbitrarily measuring five points by X-ray photoelectron spectroscopy. Further, in the X-ray photoelectron spectroscopy, a ffixps spectrometer (Model 5500, manufactured by PHI Corporation) was used, and an X-ray source which was monochromated by a monochromator was used as an X-ray source. Moreover, the detection angle of the ray photoelectron is In order to carry out the electrification correction, the cascade cascade is applied to perform the determination of 122464.doc -23 · 200811068. Further, in the present invention, the diffusion depth of boron into the interior of the glass substrate can be started by using a secondary ion mass spectroscopy (SIMS) to reach the depth of the secondary ion intensity equivalent to the substrate. Evaluation. Specifically, using a secondary ion mass spectrometer (ADEPT1〇1(), ulvac

The Phl A Division manufactured) measured the 5-diffusion depth at five points on the glass substrate, and determined the average value. Here, the conversion of the scatter time to the scatter depth is performed by Si 〇 2 conversion (4 nm = 1 mm). Furthermore, in the case where the primary ion is an oxygen ion beam, the acceleration current is 5 keV, the beam current is 4 〇〇 nA, the incident angle of the primary ion is 45 degrees with respect to the normal to the sample surface, and the beam scanning range is 4〇〇χ4〇. The measurement is carried out under the conditions of barking. In the non-inspective glass substrate of the present invention, the bottom surface of the glass substrate has an average boron concentration of 4 to 10 atoms. /. The diffusion degree of boron to the inside of the glass substrate is 5 nm or more and 80 nm or less, preferably 5 〇 or less, so that the strength of the glass substrate itself is improved, and the abrasion resistance is excellent, and the protective film is removed. In the subsequent transfer and processing steps, the scratch resistance is also excellent. The surface layer remaining on the glass substrate by diffusing from the bottom surface to the inside of the glass substrate can improve the abrasion resistance and the scratch resistance. The reason for this is that the network structure of the glass is firm. The glass-free substrate of the present invention does not wait until the cleaning step is performed as needed, and boron remains on the surface layer of the glass substrate, so that the scratch of the back surface of the glass substrate can be continuously suppressed. .doc -24- 200811068 Health, so it is better. Further, it is presumed that the reason why boron remains on the surface layer of the glass substrate in the alkali-free glass substrate of the present invention is that, by the above-mentioned step, the ruin easily enters the inside of the glass substrate and tends to remain on the surface layer of the glass substrate. Therefore, the present invention can also provide a non-inspective glass substrate which is expressed in terms of mass percentage based on an oxide and contains:

Si02 : 30~850/〇,

Al2〇3 ·· 0~35%, B203: 〇~350/〇,

MgO : 〇~35%,

CaO : 〇~35%,

SrO : 〇~35%,

BaO: 〇~35%, alkali metal component: 0.5% or less, at least one of the surfaces has an average boron concentration of 4 to 10% by atom, and boron has a diffusion depth of 5 nm or more from the surface to the inside. [Examples] Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited thereto. (Example 1) A test apparatus not shown in Fig. 2 was used. Figure 2 is a cross-sectional view of a large tubular furnace used in the examples. Specifically, Lu's quartz tube 2 is placed in a large tubular furnace U with adjustable temperature. The alkali-free glass substrate with a thickness of 0 knife mm is placed in the quartz official 12 122464.doc -25- 200811068 13 (10 cm square), which will be large The tubular furnace u is heated to 7 Torr (rc. Here, as the "alkali-free glass substrate", an amorphous glass having the following composition is used based on an oxide and expressed by mass percentage: 68G/G$Si〇2$8 〇0/〇, 〇0/〇SA1203<12%, 〇〇/0<b2〇3<7%, 〇%$MgOgl20/〇, 〇%SCa〇S 15%, 0%gSiOS4%, 〇%SBa〇 The content ratio of g 1% and the alkali component is 0.05 mass% or less. Further, the glass transition point of the glass is 700 °C.

Thereafter, the reagent 15 placed on the four sides of the oxidized crystal boat 14 is locally heated to about 85 (rc to vaporize it, and the vaporized material is shown from the end of the quartz tube to the arrow 16 The direction is sprayed, whereby sodium as an alkali metal is supplied to the surface of the glass-free substrate 13. At this time, the amount of sodium tetraborate decahydrate sprayed is 〇·4 L/m 2 , and the temperature of the alkali-free glass substrate 13 7(9). C. Next, the s〇2 gas is sprayed from the direction indicated by the arrow 17 so that the amount of the surface of the alkali-free glass substrate 13 is 〇1 L/m2, thereby forming a protective film. An alkali-free glass substrate with a protective film is produced. At this time, the temperature of the alkali-free glass substrate 13 is 7 Å. Further, the conditions of the present embodiment are sprayed between the forming step and the above-mentioned cold step. After the metal-inorganic substance was examined, the conditions for spraying the gas of s〇2 were the same. (Example 2) The same procedure as in Example 1 was carried out except that the amount of the so2 gas sprayed was changed to 04 L/m2. An alkali-free glass substrate with a protective film attached. (Example 3) In addition to the s〇2 gas in the embodiment The amount of the spray is set to be 1 〇 L/m2. 122464.doc -26- 200811068 1 The same method is used, and k is provided with a protective glass substrate without a protective film. (Comparative Example 1)

Except that BB is a sodium sulphate, and only the so2 gas is sprayed, it is the same as that of the case of the same as in the case of the neochemical example 1 (to produce an alkali-free glass substrate with a protective film. (Comparative Example 2) In addition to the ffi m A 'acid In addition, only the so2 gas is sprayed, and the alkali-free glass substrate with the protective film is manufactured by the method of "the second one".

(Comparative Example 3) An alkali-free glass substrate with a protective film was produced in the same manner as in Example 3 except that the sodium tetraborate was not used, and only the S02 gas was sprayed. (Comparative Example 4) ', sodium tetraborate was not used, and s〇2 gas was not sprayed, but only 7 〇〇. An alkali-free glass substrate was produced in the same manner as in Example 1 except for the knives. (Comparative Example 5) An alkali-free glass substrate was produced in the same manner as in Example 1 except that sodium tetraborate was not used and SO gas was not sprayed. By the method of the following, the adhesion of the protective film of the non-test glass substrate of each of the p-supplied b, ', and the rupture film obtained in the examples 1 to 3 and the comparative examples 1 to 3 was resistant to damage. The flat, mussels were measured for their properties, average boron concentration, diffusion depth and attrition resistance. The results are disclosed in Table 1 below. Further, in the glass plates for the flat panel glass obtained in Comparative Examples 4 and 5, since the protective film was not formed by spraying the S〇2 gas, the wear resistance was only used by the method described below. Determination of sex. The results 122464.doc -27- 200811068 are disclosed in Table 1 below. <Protective film adhesion amount> The protective film of the alkali-free glass substrate with the protective film obtained therein was dissolved in pure water. 'Inductively clamped plasma ICP emission spectrometry was used. To carry out sulfur for $4, and use atomic absorption to quantify the nano. Calculate the amount of sodium sulfate attached as a protective film according to (4) Quantitative value

Attached. Further, the amount of adhesion was determined as an average value calculated from the obtained enamel alkali-free glass substrate. <Strain resistance> The evaluation of the scratch resistance was carried out by using Tabe^ according to JIS 221 (199 〇), and the Taber test was performed by using a Taber tester (Tdedyne Taber Model 503) cs_1〇F, the load is 250 g, and the number of wear is fixed at 3 times. Thereafter, in order to remove the protective film of the non-inspective glass substrate with the protective film used as the test body, the substrate was washed with water under a stream of pure water (3 liters/min) for 30 seconds. The surface of the glass substrate obtained by removing the protective film was observed with a microscope, and the amount of the flaw (four) which was within the length of the i cmxl em square and the length in the long axis direction was 〇2 or more (the number of scars) was measured. The measurement unit is a central portion of a portion to be tested, for example (see Fig. 3). In Fig. 2, in the test body (without the glass substrate) 18, the wear (four) is formed by the wheel (four), and the measuring portion 20 becomes the central portion of the wear portion 19. Further, the number of flaws generated is calculated for any of the respective pieces of the glass substrate, 122464.doc -28-200811068, and the average value thereof is obtained. Further, the number of damage occurrences was obtained as an average value calculated from the obtained one glass substrate. <Average boron concentration·diffusion depth> (1) At the place where 20 t of pure water (flow rate··3 liters/min) was poured, the obtained alkali-free glass substrate with the protective film obtained was washed with water to remove the protection. membrane. Thereafter, the average boron concentration on the surface of the glass substrate after the cleaning was determined as an average value measured by X-ray photoelectron spectroscopy at five points. Further, in the X-ray photoelectron spectroscopy, an energy spectrometer (Μ(9) type, PHI A Division & ) is used, and a ray which is monochromated by a monochromator is regarded as a ray source. Further, the detection angle of the x-ray photoelectron is 75. In order to perform charging correction, the measurement is performed by irradiating the cascade beam. (7) The depth of diffusion of the shed into the interior of the glass substrate is evaluated by the secondary separation method (sms) from the depth 2 of the secondary ionic strength equivalent to the substrate. Specifically, 5, using a secondary ion mass spectrometer (ADEPTHH0, Ulvac

Phi company)), in the wash of the Pan you t # / 冼 之 之 之 之 之 之 之 之 之 之 之 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃 玻璃Here, (4) the dispersion time is converted into W ^ by Si〇2 conversion (4 nm = i min). Furthermore, the _ human ion is an oxygen ion beam, the accelerating voltage is 5 keV, and the incident angle of the beam and ip is relative to the normal of the sample surface: the measurement is performed under the condition of the circumference. For the next 4 t, the diffusion depth of the comparative example μ was not confirmed for diffusion. J recorded no &lt; ft only wearability &gt; 122464.doc -29- 200811068 The abrasion resistance was carried out by investigating the rate of change of turbidity rate (turbidity change rate) before and after the Taber test.彳 f first' The turbidity rate of each of the obtained alkali-free glass substrates was measured by a turbidimeter. </ </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> </ RTI> <RTIgt; Furthermore, the Taber test is used

Taber Detector (Tdedyne Taber Model 503), the wear wheel is fixed at d _ 10F, and the load is fixed at 500 g. Then, the turbidity rate after 1000 times of Taber abrasion was measured by a turbidimeter. The rate of change was determined from the turbidity rate before the Taber test. Here, the haze value can be defined as follows by using scattered light (Td) and transmitted light (Tt). Turbidity rate = (Td / Tt) x 100% Further, the rate of change (δη) of the turbidity rate (Η) can be expressed by the following formula. △Η=turbidity rate H_Tabe after 1 000 abrasions, turbidity rate before test • Η [Table 1] 122464.doc -30- 200811068 Table 1 Sodium tetraborate spray (L/m2) so2 gas spray Amount (L/m2) Protective film adhesion (mg/10 cm square) Number of damage resistance (units / 10 cm square) Average boron concentration (at%) Diffusion depth (nm) Perturbation turbidity change rate ( %) Example 1 0.4 0.011 0.011 12 7.4 10 2.3 Example 2 0.4 0.4 0.035 1 7.4 10 2.3 Example 3 0.4 1.0 0.058 0 ΊΑ 10 2.3 Comparative Example 1 - 0.1 0.010 24 3.1 Coffee 3.4 Comparative Example 2 Sleep 0.4 0.011 10 3.1 3.4 Comparative Example 3 1.0 0.011 5 3.1 3.4 Comparative Example 4 _=—一• - Sleep 3.2 Comparative Example 5 —---- ~-——-~~— 33 From the results shown in Table 1, it is known that sodium tetraborate is used. The obtained example

The glass film of =3 was compared with the comparison of ～3, and the amount of gas sprayed was equal to or lower than that of s〇2, and a protective film was effectively formed. It is also known that the boron concentration is also high and the scratch resistance is also particularly good. Further, in Comparative Examples 1 to 3, although the amount of sodium sulphate was equivalent, as the amount of S 〇 2 gas was increased, the number of smear 1 was reduced, which was because the soil was generated by soil testing. Sulfate (such as sulfur (tetra), sulphate, etc.) derived from a metal-like substance, and its oxime acts as a protective film. Further, the surface of the m-to-three surface substrate (4) is usually washed with water: The protective film formed on the surface of the glass substrate is removed to exhibit a surface. On the other hand, in the case of the non-inspected glass substrate of the comparative example 3, the protective film formed on the surface of the glass substrate was not removed and remained. Further, when the film component remaining is measured, it is calcium sulfate and sulfuric acid. Further, it is known that the alkali-free glass substrate of Example u is diffused by boron, so that the turbidity change rate is reduced and the wear resistance is improved as compared with the alkali-free glass substrates of Comparative Examples 1 to 5. The present invention has been described with reference to the particular embodiments of the invention, and the invention may be modified or modified without departing from the spirit and scope of the invention. The present application is hereby incorporated by reference in its entirety by reference in its entirety in its entirety in the the the the the the the the [Industrial Applicability] According to the present invention, it is possible to provide a protective film which can be easily removed in the washing step, thereby achieving a reduction in the amount of sulfur dioxide used, and suppressing the occurrence of damage on the back surface of the glass substrate. A method for producing an alkali glass substrate, and an alkali-free glass substrate obtained by the method. The alkali-free glass substrate of the present invention can be suitably used in a high-quality display. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a conceptual diagram showing an example of a glass manufacturing line using a floating method. Figure 2 is a cross-sectional view of a large tubular furnace used in the examples. Fig. 3 is an explanatory view showing a portion (abrasion portion) touched by the abrasion wheel of the Taber test machine used for the evaluation of the scratch resistance, and a measurement portion (measurement portion) of the number of damages. 122464.doc -32- 200811068

[Explanation of main components] 1 Molten tin 2 Molten tin bath 3 Melting kiln 4 Molten glass 5 Guided by Kuk Kun 6 Xu cold furnace 11 Large tubular furnace 12 Quartz tube 13 No glass substrate 14 Alumina boat 15 Reagent 16, 17 Arrow 18 Test Body 19 Wear part 20 Measuring part 122464.doc -33 -

Claims (1)

200811068 X. Patent application scope: 1. A method for manufacturing a non-inspective glass substrate, which is a method for cultivating an alkali-free glass substrate by a floating method; and comprising: a forming step of forming molten glass on a molten tin into a glass substrate And the cold step of causing the glass substrate formed by the forming step to be cold-cooled, and the first supplying step of spraying the alkali-containing surface onto the surface of the glass substrate on the side in contact with the molten tin. The second inorganic material is supplied to the surface of the glass substrate on the side in contact with the molten tin after the ith supply step. 2. The method of producing an alkali-free glass substrate according to claim 1, wherein the step of supplying the first step is performed between the forming step and the step of quenching. The method of producing an alkali-free glass substrate according to claim 1, wherein the i-th supply step is carried out at a temperature in a range of a glass transition point of the glass substrate. The method for producing an alkali-free glass substrate according to the item 1, wherein the first supplying step is carried out at 600 to 800 °C. The method for producing an alkali-free glass substrate according to any one of claims 4 to 4, wherein the second supply step is performed between the forming step and the quenching step. The method for producing an alkali-free glass substrate according to any one of claims 4 to 4, wherein the second supply step is carried out at a temperature within a range of a glass transition point of the glass substrate. The method for producing an alkali-free glass substrate according to any one of claims 1 to 4, wherein the second supply step of 122464.doc 200811068 is carried out at 600 to 800 °C. 8. A method for producing an alkali-free glass substrate, which is a method for manufacturing an alkali-free glass substrate by a floating method; and comprising: a forming step of forming a molten glass on a molten tin to form a glass substrate; a first supply step of ejecting an alkali metal-containing inorganic substance onto the surface of the glass substrate on the side in contact with the molten tin at 600 to 80 (TC); and a second supply step in the above-described first supply step Then, the method of manufacturing the alkali-free glass substrate according to any one of claims 1 to 8, wherein the method of manufacturing the alkali-free glass substrate according to any one of claims 1 to 8, wherein the method of producing the alkali-free glass substrate according to any one of claims 1 to 8, wherein: Further, a cleaning step for removing the protective film is provided. The method for producing an alkali-free glass substrate according to any one of claims 1 to 9, wherein the inorganic substance containing the metal-containing metal contains a nano-sheath. Item 1 The method for producing a non-inspective glass substrate, wherein the inorganic substance containing the metal detector is sodium tetradecanoate. 12 An alkali-free glass substrate produced by the manufacturing method of the claim 1〇4U 13 · An alkali-free glass substrate produced by the manufacturing method of the claim 〇 or 〗 〖, wherein the glass substrate is expressed by mass percentage based on oxide, and contains: Si02: 30-&gt; 85%, Al2〇3: 〇~350/〇, B2〇3: 〇~35%, 122464.doc 200811068 Mg〇: 〇~35%, CaO: 〇~35%, SrO: 〇~3 5%, BaO: 〇~ 35%, an alkali metal component: 0.5% or less, an average of the surface of the glass substrate on the side in contact with the molten tin The boron concentration is 4 to 10% by atom, and the diffusion depth of boron into the inside of the glass substrate is 5 nm or more. 14. An alkali-free glass substrate, which is expressed by mass percentage based on an oxide, and contains: · Si02: 30 to 85%, Al2〇3: 〇~35%, B2〇3: 〇~35〇/〇, Mg〇: 〇~35〇/〇, CaO : 〇~35%, SrO : 〇~35%, Ba〇: 0~35%, alkali metal composition: 〇·5% or less, to ^ where - the average boron of the surface The concentration is 4 to 1 atom%, and the diffusion depth of boron from the surface to the inside is 5 nm or more. 122464.doc