阅读说明：本技术 红外线吸收玻璃的制造方法 (Method for producing infrared absorbing glass ) 是由 片山裕贵 坂出喜之 于 2019-08-26 设计创作，主要内容包括：本发明涉及红外线吸收玻璃的制造方法,其具备下述工序：准备工序,准备作为玻璃组成以阳离子％表示含有5％以上的P～(5+)以及0.5％以上的Cu～(2+)的玻璃(步骤S1)；以及第1处理工序,使用水对玻璃进行处理(步骤S2)。红外线吸收玻璃的制造方法进一步具备第2处理工序,进行将附着于玻璃表面的水使用与该水相溶的有机溶剂进行稀释或除去的处理(步骤S3)。(The present invention relates to a method for producing infrared-absorbing glass, comprising the steps of: a preparation step of preparing a glass composition containing 5% or more of P in terms of cation% 5+ And 0.5% or more of Cu 2+ The glass of (4) (step S1);and a 1 st treatment step of treating the glass with water (step S2). The method for producing infrared-absorbing glass further comprises a 2 nd treatment step of diluting or removing water adhering to the glass surface with an organic solvent that is soluble in the water (step S3).)

1. A method for producing an infrared-absorbing glass, comprising the steps of:

a preparation step of preparing a glass composition containing 5% or more of P in terms of cation%⁵⁺And 0.5% or more of Cu²⁺The glass of (2);

a first treatment step of treating the glass with water; and

and a 2 nd treatment step of, after the 1 st treatment step, diluting or removing water adhering to the glass surface with an organic solvent compatible with the water.

2. The method for producing an infrared absorbing glass according to claim 1, wherein the 2 nd treating step comprises a treating solution dipping step of dipping the glass in a treating solution containing the organic solvent.

3. The method for producing infrared-absorbing glass according to claim 2, wherein ultrasonic waves are irradiated to the glass in the treatment liquid at the treatment liquid immersion stage in the treatment step 2.

4. The method for producing an infrared absorbing glass according to any of claims 1 to 3, wherein the 2 nd treatment step comprises a spraying step of spraying a treatment liquid containing the organic solvent onto the glass.

5. The method for producing an infrared absorbing glass according to any of claims 1 to 4, wherein the 1 st treatment step comprises a polishing step of polishing the glass.

6. The method for producing an infrared absorbing glass according to any of claims 1 to 5, wherein the 1 st treatment step comprises a scrubbing step of wiping the glass with a resin foam.

7. The method for producing an infrared absorbing glass according to any of claims 1 to 6, wherein the 1 st treatment step comprises an immersion cleaning step of immersing the glass in an aqueous cleaning solution containing water to clean the glass.

8. The method for producing infrared-absorbing glass according to claim 7, wherein the aqueous cleaning liquid used in the immersion cleaning step of the 1 st treatment step contains a surfactant.

9. The method for producing infrared-absorbing glass according to claim 8, wherein the pH of the aqueous cleaning solution containing the surfactant is in a range of 9 or more and 13 or less.

10. The method for producing an infrared absorbing glass according to any of claims 1 to 9, wherein the organic solvent used in the 2 nd treatment step has a higher volatility than the water.

11. The method for producing an infrared absorbing glass according to any of claims 1 to 10, wherein the treatment in the treatment step 2 after the treatment step 1 is repeated 2 or more times.

12. The method for producing an infrared absorbing glass according to any of claims 1 to 11, wherein the glass prepared in the preparation step contains P in terms of cation% as a glass composition⁵⁺：5％～50％、Al³⁺: 2 to 30 percent of R, R is at least one selected from Li, Na and K⁺: 10 to 50 percent of R ', and R' is at least one R 'selected from Mg, Ca, Sr, Ba and Zn'²⁺: 20% to 50%, and Cu²⁺: 0.5 to 15%, and contains F in terms of anion%^-: 5% to 80%, and O^2-：20％～95％。

Technical Field

The present invention relates to a method for producing infrared-absorbing glass.

Background

Conventionally, as disclosed in patent document 1, a glass composition containing 5% or more of P in terms of cation% has been proposed⁵⁺And 0.5% or more of Cu²⁺Infrared absorbing glass of (2) is well known. Such an infrared absorbing glass is used for a filter for correcting the sensitivity of a solid-state image sensor such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-199430

Disclosure of Invention

Problems to be solved by the invention

The infrared absorption glass contains 5% or more of P in terms of cation% as a glass composition⁵⁺And 0.5% or more of Cu²⁺And polishing, washing, etc. the glass of (4).

Here, with SiO₂The above-mentioned glass or the like as the main component is compared with P⁵⁺Since glass composed of glass as a main component has extremely low water resistance, when the glass is left in a state of being wetted with water adhering thereto by treatment such as polishing or washing, the glass may be embrittled or the like, and the quality of the glass may not be sufficiently maintained.

The present invention has been made in view of such circumstances, and an object thereof is to provide a method for producing an infrared absorbing glass which can suppress a reduction in quality.

Means for solving the problems

The method for manufacturing the infrared absorption glass for solving the problems comprises the following stepsThe method comprises the following steps: a preparation step of preparing a glass composition containing 5% or more of P in terms of cation%⁵⁺And 0.5% or more of Cu²⁺The glass of (2); a first treatment step of treating the glass with water; and a 2 nd treatment step of, after the 1 st treatment step, diluting or removing water adhering to the glass surface with an organic solvent compatible with the water.

According to this method, water adhering to the glass surface after the 1 st treatment step is diluted or removed in the 2 nd treatment step using an organic solvent, whereby embrittlement of the glass due to contact between the glass surface and water can be suppressed.

In the method for producing an infrared-absorbing glass, the 2 nd treatment step preferably includes a treatment liquid immersion step of immersing the glass in a treatment liquid containing the organic solvent.

According to this method, water adhering to the glass surface can be quickly diluted or removed.

In the method for producing an infrared-absorbing glass, it is preferable that the glass in the treatment liquid is irradiated with ultrasonic waves in the treatment liquid immersion stage of the 2 nd treatment step.

According to the method, the cleanability of the glass can be further improved in the treatment liquid immersion stage.

In the method for producing an infrared-absorbing glass, the 2 nd treatment step preferably includes a step of spraying a treatment liquid containing the organic solvent onto the glass.

According to this method, for example, the amount of the organic solvent to be used can be suppressed.

In the method for producing an infrared-absorbing glass, the 1 st treatment step preferably includes a polishing step of polishing the glass.

According to this method, an infrared-absorbing glass having improved surface smoothness can be obtained.

In the method for producing an infrared-absorbing glass, the 1 st treatment step preferably includes a scrubbing step of wiping the glass with a resin foam.

According to this method, since foreign matter adhering to the surface of the glass can be easily removed, the cleanability of the glass can be easily improved.

In the method for producing an infrared absorbing glass, the 1 st treatment step preferably includes an immersion cleaning step of immersing the glass in an aqueous cleaning solution containing water to clean the glass.

According to this method, the cleanability of the glass can be easily improved by using an aqueous cleaning liquid.

In the method for producing an infrared-absorbing glass, the aqueous cleaning liquid used in the immersion cleaning step of the treatment step 1 preferably contains a surfactant.

According to this method, the cleaning property of the glass surface can be further easily improved by the cleaning action of the surfactant.

In the method for producing the infrared absorbing glass, the pH of the aqueous cleaning solution containing the surfactant is preferably in a range of 9 or more and 13 or less.

According to this method, for example, embrittlement of the glass can be suppressed and the cleanability of the glass can be improved.

In the method for producing infrared-absorbing glass, the organic solvent used in the treatment step 2 is preferably higher in volatility than the water.

According to this method, for example, the glass can be dried quickly.

In the method for producing the infrared absorbing glass, the treatment operation of performing the treatment step 2 after the treatment step 1 may be repeated 2 or more times.

This method can cope with, for example, a higher degree of glass treatment.

In the method for producing an infrared-absorbing glass, it is preferable that the glass prepared in the preparation step contains P in terms of cation% as a glass composition⁵⁺：5～50％、Al³⁺：2～30％、R⁺(wherein R is selected from at least one of Li, Na and K): 10-50% of R'²⁺(wherein R' is selected from at least one of Mg, Ca, Sr, Ba and Zn): 20 to 50%, and Cu²⁺：05 to 15%, and contains F in the form of anionic%^-: 5 to 80%, and O^2-：20～95％。

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the deterioration of the grade of the infrared absorbing glass can be suppressed.

Drawings

Fig. 1 is a flowchart illustrating a method for manufacturing an infrared absorbing glass according to an embodiment.

Fig. 2 is a flowchart showing the first treatment step of the method for producing infrared-absorbing glass 1.

Fig. 3 is a flowchart showing the 2 nd treatment step of the method for producing the infrared absorbing glass.

Fig. 4 is a flowchart showing a method for manufacturing the infrared absorbing glass according to the modification.

Detailed Description

Embodiments of a method for producing infrared-absorbing glass will be described below with reference to the drawings.

As shown in fig. 1, the method for producing an infrared absorbing glass includes the steps of: a preparation step of preparing a glass composition containing 5% or more of P in terms of cation%⁵⁺And 0.5% or more of Cu²⁺The glass of (4) (step S1); and a 1 st treatment step of treating the glass with water (step S2). The method for producing infrared-absorbing glass further comprises a 2 nd treatment step of diluting or removing water adhering to the glass surface with an organic solvent that is soluble in the water after the 1 st treatment step in step S2 (step S3).

First, the preparation process of step S1 will be described.

The glass prepared in the preparation step of step S1 is preferably the following glass: the glass composition contains P in cationic% form⁵⁺：5～50％、Al³⁺：2～30％、R⁺(wherein, R is at least one selected from Li, Na and K): 10-50% of R'²⁺(wherein, R' is selected from at least one of Mg, Ca, Sr, Ba and Zn): 10 to 50%, and Cu²⁺: 0.5 to 15%, and contains F in terms of anion%^-：5～80％And O^2-：20～95％。

As a more preferable specific example of the glass, there can be mentioned a glass composition containing P in cationic% as the glass composition⁵⁺：40～50％、Al³⁺：7～12％、K⁺：15～25％、Mg²⁺：3～12％、Ca²⁺：3～6％、Ba²⁺：7～12％、Cu²⁺: 1 to 15% and contains F in anionic% form^-: 5 to 80%, and O^2-: 20 to 95% of glass (phosphate glass).

As another specific example of a more preferable glass, there can be mentioned a glass composition containing P in cationic% as the glass composition^{5 +}：20～35％、Al³⁺：10～20％、Li⁺：20～30％、Na⁺：0～10％、Mg²⁺：1～8％、Ca²⁺：3～13％、Sr²⁺：2～12％、Ba²⁺：2～8％、Zn²⁺: 0 to 5%, and Cu²⁺: 0.5 to 5%, and F is contained in the form of anion%^-: 30 to 65%, and O^2-: 35-75% of glass (fluorophosphate glass).

As another specific example of a more preferable glass, there can be mentioned a glass composition containing P in cationic% as the glass composition^{5 +}：35～45％、Al³⁺：8～12％、Li⁺：20～30％、Mg²⁺：1～5％、Ca²⁺：3～6％、Ba²⁺: 4 to 8%, and Cu^{2 +}: 1 to 6%, and F is contained in the form of anion%^-: 10 to 20%, and O^2-: 75-95% of glass (fluorophosphate glass).

As a more preferable specific example of the other glass, there can be mentioned a glass composition containing P in cationic% as the glass composition^{5 +}：30～45％、Al³⁺：15～25％、Li⁺：1～5％、Na⁺：7～13％、K⁺：0.1～5％、Mg²⁺：1～8％、Ca²⁺：3～13％、Ba²⁺：6～12％、Zn²⁺: 0 to 7%, and Cu²⁺: 1 to 5%, and is represented by the anion%Containing F^-: 30 to 45%, and O^2-: 50-70% of glass (fluorophosphate glass).

The glass is preferably plate-shaped. The thickness of the plate glass is preferably 0.4mm or less, more preferably 0.3mm or less, and still more preferably 0.02mm or more and 0.2mm or less.

Glass is obtained by melting, clarifying, stirring and other steps of a glass raw material to obtain molten glass, and molding the molten glass by a known method. Glass can be obtained by a forming method such as a method of cutting a glass ingot formed from molten glass, an overflow down-draw method, a down-draw method (a slit down-draw method, a redraw method, or the like), and a float method.

Next, the 1 st processing step of step S2 will be described.

As shown in fig. 2, the 1 st processing step of step S2 in the present embodiment includes a polishing step (step S2A) of polishing glass. The polishing step of step S2A can be performed by a known polishing method using an aqueous polishing liquid and a polishing pad, for example. The polishing in the polishing stage of step S2A may be performed by a polishing method in which a polishing tape is moved or reciprocated. The polishing in the polishing stage of step S2A may be any one of chemical polishing, mechanical polishing, and chemical mechanical polishing. The polishing in the polishing step of step S2A may be rough polishing (lapping polishing) or precise polishing (finish polishing, mirror polishing). The polishing step of step S2A may be surface polishing in which the surface of the plate-like glass is polished, or may be end surface polishing in which the end surfaces of the plate-like glass are polished.

The treatment step 1 of step S2 in the present embodiment further includes an immersion cleaning step (step S2B) of immersing the glass in an aqueous cleaning solution containing water to clean the glass. The aqueous cleaning solution may be composed of water alone, or may contain a surfactant. Examples of the surfactant contained in the aqueous cleaning solution include an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. The pH of the aqueous cleaning solution containing a surfactant is preferably in the range of 9 to 13. The pH of the aqueous cleaning solution was measured at 20 ℃. The pH of the aqueous cleaning solution can be adjusted as necessary by using a pH adjuster (inorganic or organic base, inorganic or organic acid, or the like) and a buffer. The content of the surfactant in the aqueous cleaning solution is preferably in the range of 1 mass% to 5 mass%. In this case, the cleaning action of the surfactant can be improved, and the surfactant remaining on the glass surface can be reduced. In the immersion cleaning step of step S2B, the glass is immersed in a cleaning bath filled with an aqueous cleaning solution, for example, in a state where one or more glass sheets are supported by a jig in a vertical posture. The glass may be immersed in the cleaning tank in a state of being supported in a lateral posture. The temperature of the aqueous cleaning liquid used in the immersion cleaning step of step S2B is, for example, 1 to 90 ℃, preferably 5 to 50 ℃, and more preferably 10 to 40 ℃. The dipping time in the dipping and cleaning step of step S2B is, for example, 1 to 10 minutes, preferably 1 to 5 minutes, and more preferably 1 to 3 minutes.

Here, the glass immersed in the aqueous cleaning liquid is in a state in which embrittlement by water is likely to occur, and when the glass in this state is irradiated with ultrasonic waves, the glass is likely to be corroded (eroded). In order to suppress the occurrence of such corrosion, the cleaning in the immersion cleaning stage of step S2B is preferably performed without irradiating the glass with ultrasonic waves.

The process 1 of step S2 in the present embodiment further includes a scrubbing step of wiping the glass with the resin foam (step S2C). Examples of the resin foam used in the scrubbing step of step S2C include polyvinyl alcohol resin, polyurethane resin, polyolefin resin, and melamine resin.

The scrubbing step of step S2C may be performed by pressing a rotating pad or a rotating roller made of the resin against the main surface of the glass, or may be performed manually by an operator.

Next, the process 2 of step S3 will be described.

Examples of the organic solvent used in the step 2 of the step S3 include alcohols, ketones, ethers, and the like. Among the organic solvents, organic solvents having higher volatility than water are preferred, monohydric alcohols having 1 to 3 carbon atoms are more preferred, and isopropyl alcohol is further preferred.

As shown in fig. 3, the 2 nd treating step of step S3 in the present embodiment includes a treating liquid immersing step (step S3A) of immersing the glass in a treating liquid containing an organic solvent. The treatment solution used in the treatment solution immersion step of step S3A contains an organic solvent as a main component, and may further contain water or the like compatible with the organic solvent. The content of the organic solvent in the treatment liquid used in the treatment liquid immersion step of step S3A is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more. By increasing the content of the organic solvent in the treatment liquid, embrittlement of the glass can be further suppressed. The temperature of the treatment solution used in the treatment solution immersion step of step S3A is, for example, 1 to 90 ℃, preferably 5 to 50 ℃, and more preferably 10 to 40 ℃. The immersion time in the treatment liquid immersion step of step S3A is, for example, 1 to 10 minutes, preferably 1 to 5 minutes, and more preferably 1 to 3 minutes.

In the treatment liquid immersion step of step S3A, the glass is immersed in a treatment tank filled with the treatment liquid, for example, in a state where a single glass sheet or a plurality of glass sheets are supported by a jig in a vertical posture. The glass may be immersed in the treatment tank in a state of being supported in a lateral posture.

In the treatment liquid immersion step of step S3A, it is preferable to irradiate the glass in the treatment liquid with ultrasonic waves. In the treatment liquid immersion step of step S3A, a known ultrasonic cleaning apparatus may be used.

The 2 nd treatment step of step S3 in the present embodiment further includes a spraying step of spraying a treatment liquid containing an organic solvent onto the glass (step S3B). The treatment liquid used in the spraying step of step S3B may contain an organic solvent as a main component, or may further contain water or the like compatible with the organic solvent.

The content of the organic solvent in the treatment liquid used in the spraying stage of step S3B is preferably higher than the content of the organic solvent in the treatment liquid used in the impregnation stage of the treatment liquid of step S3A. The content of the organic solvent in the treatment liquid used in the spraying step of step S3B is preferably 90 mass% or more, and more preferably 95 mass% or more. By increasing the content of the organic solvent in the treatment liquid, embrittlement of the glass can be further suppressed. In addition, when an organic solvent having higher volatility than water is used as the organic solvent, the glass can be dried quickly. That is, in the final stage of the treatment step 2 in step S3 (stage of obtaining the infrared-absorbing glass to be tested), it is preferable to use a treatment liquid containing 90 mass% or more of an organic solvent having a higher volatility than water in order to further suppress embrittlement of the glass and quickly dry the glass surface.

In the spraying stage of step S3B described above, a single-fluid spray nozzle or a two-fluid spray nozzle may be used. In the spraying step of step S3B, the glass is sprayed with the treatment liquid onto both main surfaces of the glass in a state where, for example, a single sheet or a plurality of sheets are supported by the jig in a vertical posture. The glass may be supported in a lateral posture and the treatment liquid may be sprayed onto both main surfaces of the glass. The temperature of the spraying atmosphere in the spraying step of step S3B is, for example, 1 to 90 ℃, preferably 5 to 50 ℃, and more preferably 10 to 40 ℃. The spraying time in the spraying step of step S3B is, for example, 1 to 10 minutes, preferably 1 to 5 minutes, and more preferably 1 to 3 minutes.

In the method for producing the infrared absorbing glass, the treatment operation of performing the 2 nd treatment step after the 1 st treatment step may be repeated 2 or more times. That is, in the method for producing the infrared absorbing glass, the treatment operation may be performed 2 times or more with the treatment step 1 and the treatment step 2 as 1 treatment operation.

Infrared-absorbing glass obtained by the method for producing infrared-absorbing glass is inspected for the presence or absence of surface abnormalities (scratches and the like), and then shipped in a packaged state.

The glass obtained by the method for producing an infrared absorbing glass can be suitably used for a filter application for correcting the sensitivity of a solid-state image sensor such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

Next, the operation and effect of the present embodiment will be described.

(1) The method for producing the infrared absorbing glass includes a preparation step of step S1, a 1 st processing step of step S2, and a 2 nd processing step of step S3.

According to this method, water adhering to the glass surface after the 1 st treatment step of step S2 is diluted or removed by an organic solvent in the 2 nd treatment step of step S2, whereby embrittlement of the glass due to contact between the glass surface and water can be suppressed. This can suppress a reduction in the grade of the infrared-absorbing glass.

(2) In the method for producing infrared-absorbing glass, the 2 nd treatment step of step S3 preferably includes a treatment liquid immersion step of step S3A. In this case, water adhering to the glass surface can be quickly diluted or removed.

(3) When the 2 nd processing step of step S3 includes the processing liquid immersion step of step S3A, it is preferable to irradiate the glass in the processing liquid with ultrasonic waves in the processing liquid immersion step of step S3A. In this case, the cleaning property of the glass can be further improved by the treatment liquid immersion step of step S3A.

(4) In the method for producing infrared-absorbing glass, the 2 nd treatment step of step S3 preferably includes a spraying step of step S3B. In this case, for example, the amount of the organic solvent to be used can be suppressed.

(5) In the method for producing the infrared absorbing glass, the 1 st processing step of step S2 preferably includes a polishing step of step S2A. In this case, the infrared absorbing glass having improved surface smoothness can be obtained.

(6) In the method for manufacturing the infrared absorbing glass, the 1 st processing step of step S2 preferably includes a scrubbing step of step S2C. In this case, since the foreign matter adhering to the surface of the glass can be easily removed, the cleanability of the glass can be easily improved.

(7) In the method for producing the infrared absorbing glass, the 1 st processing step of step S2 preferably includes a dip cleaning stage of step S2B. In this case, the cleanability of the glass can be easily improved by using an aqueous cleaning liquid.

(8) The aqueous cleaning liquid used in the immersion cleaning step of step S2B preferably contains a surfactant. In this case, the cleaning property of the glass surface can be more easily improved by the cleaning action of the surfactant.

(9) When the aqueous cleaning solution containing the surfactant is used in the immersion cleaning step of step S2B, the pH of the aqueous cleaning solution is preferably in the range of 9 to 13. In this case, for example, embrittlement of the glass can be suppressed, and the cleanability of the glass can be improved.

(10) The organic solvent used in the 2 nd treating step of step S3 is preferably higher in volatility than water. In this case, for example, the glass can be dried quickly.

The organic solvent used in the treatment liquid immersion step of step S3A and the organic solvent used in the spraying step of step S3B may be the same or different from each other. For example, an organic solvent having a lower volatility than water may be used in the treatment liquid immersion stage of step S3A and an organic solvent having a higher volatility than water may be used in the spraying stage of step S3B.

(11) In the method for producing the infrared absorbing glass, the treatment operation of performing the treatment step 2 of the step S3 after the treatment step 1 of the step S2 may be repeated 2 or more times. In this case, for example, by performing the polishing step of step S2A 2 or more times, it is possible to cope with a higher degree of glass treatment. In addition, since embrittlement of the glass can be suppressed even when the time from the end of the 1 st processing operation to the start of the subsequent 2 nd processing operation is extended, the degree of freedom in the manufacturing process of the infrared absorbing glass can be improved by securing a standby time between the processes.

(modification example)

This embodiment can be modified as follows. This embodiment mode and the following modifications can be combined with each other within a range not technically contradictory.

In the method for producing the infrared absorbing glass, the 1 st treatment step of step S2 may be composed of at least one stage. The 1 st processing step of step S2 may be changed to a step including, for example, a shower cleaning stage of cleaning the glass using a shower nozzle for spraying water. The 1 st process step of step S2 preferably includes at least one of the polishing step S2A, the immersion cleaning step S2B, the scrubbing step S2C, and the shower cleaning step.

In the method for producing the infrared absorbing glass, the 2 nd processing step of step S3 may be composed of at least one stage. The 2 nd processing step of step S3 may be modified to include, for example, a processing liquid supply step of supplying a processing liquid to the glass using a shower nozzle for spraying the processing liquid containing an organic solvent. The 2 nd processing step of step S3 preferably includes at least one of the processing liquid immersion step of step S3A, the spraying step of step S3B, and the processing liquid supply step.

In the 1 st processing step of step S2, the sequence of the immersion cleaning step of step S2B and the scrubbing step of step S2C may be changed.

In the 1 st processing step of step S2 or the 2 nd processing step of step S3, the same step may be repeated 2 or more times. For example, in the immersion cleaning step of step S2B, 2 or more immersion tanks may be prepared, and the immersion cleaning step of step S2B may be repeated 2 or more times by sequentially immersing glass in the 2 or more immersion tanks. In this case, the compositions of the aqueous cleaning liquids in the 2 or more tanks may be the same composition or different compositions from each other. For example, in the treatment liquid immersion step of step S3A, 2 or more immersion tanks may be prepared, and the treatment liquid immersion step of step S3A may be repeated 2 or more times by sequentially immersing glass in the 2 or more immersion tanks. In this case, the compositions of the treatment liquids in 2 or more tanks may be the same composition or different compositions from each other.

After the 2 nd processing step of step S3, the etching step of step S4 may be further performed as shown in fig. 4. The etching step of step S4 is performed by, for example, immersing glass in an etching solution. As the etching solution, for example, a cleaning agent containing an alkaline component such as Na or K, a surfactant such as triethanolamine, benzyl alcohol or glycol, and water or alcohol can be used. For example, hydrofluoric acid, hydrochloric acid, or the like may be further added to the etching solution at a low concentration. Since the glass subjected to the treatment in steps S1 to S3 of the present invention is less likely to be corroded and embrittled, breakage and hole defects are less likely to occur in the etching step in step S4, and high-quality glass can be obtained.

After the etching step in step S4, the glass is preferably further washed with water. After the cleaning, the process of the 2 nd process step of step S3 may be executed again. With this configuration, the etching liquid adhering to the glass in the etching step of step S4 can be removed appropriately, and embrittlement of the glass due to residual moisture can be suppressed.

The present invention includes the following configurations.

[ additional notes 1]

A method for producing an infrared absorbing glass according to a non-limiting example, comprising the steps of:

a step of preparing a base material containing 5% or more of P in terms of cation%⁵⁺And 0.5% or more of Cu²⁺E.g., a glass plate;

treating the base material with water; and

and a step of diluting or removing the water adhering to the surface of the substrate with an organic solvent compatible with water after the step of treating the substrate.

[ appendix 2]

In a non-limiting example, the step of diluting or removing water from the surface of the substrate includes immersing the substrate in a treatment solution containing the organic solvent.

[ additional notes 3]

In a non-limiting example, when the base material is immersed in the treatment liquid, ultrasonic waves are irradiated to the base material in the treatment liquid.

[ additional notes 4]

In a non-limiting example, the step of diluting or removing water from the surface of the substrate includes spraying a treatment liquid containing the organic solvent onto the substrate.

[ additional notes 5]

In a non-limiting example, the step of treating the substrate comprises polishing the substrate.

[ additional notes 6]

In a non-limiting example, the step of treating the substrate includes scrubbing the substrate with a resin foam.

[ additional notes 7]

In a non-limiting example, the step of treating the substrate includes immersing the substrate in an aqueous cleaning solution to clean the substrate.

[ additional notes 8]

In a non-limiting example, the aqueous cleaning solution contains a surfactant.

[ appendix 9]

In a non-limiting example, the pH of the aqueous cleaning solution is 9 to 13.

[ appendix 10]

In a non-limiting example, the organic solvent has a higher volatility than water.

[ appendix 11]

In a non-limiting example, the step of treating the substrate and the subsequent step of diluting or removing water from the surface of the substrate are repeated a plurality of times.

[ appendix 12]

In a non-limiting example, the base material contains 5 to 50% of P in terms of cation%⁵⁺2 to 30% of Al^{3 +}10 to 50% of R⁺(wherein R is at least one selected from Li, Na and K), and 20-50% of R'²⁺(wherein R' is at least one selected from Mg, Ca, Sr, Ba and Zn), and 0.5-15% Cu²⁺And 5 to 80% of F is contained in terms of anion%^-And 20 to 95% of O^2-。