JPS6149256B2 - - Google Patents
Info
- Publication number
- JPS6149256B2 JPS6149256B2 JP56072253A JP7225381A JPS6149256B2 JP S6149256 B2 JPS6149256 B2 JP S6149256B2 JP 56072253 A JP56072253 A JP 56072253A JP 7225381 A JP7225381 A JP 7225381A JP S6149256 B2 JPS6149256 B2 JP S6149256B2
- Authority
- JP
- Japan
- Prior art keywords
- acid
- glass
- mineral acid
- phase
- mineral
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C23/00—Other surface treatment of glass not in the form of fibres or filaments
- C03C23/008—Other surface treatment of glass not in the form of fibres or filaments comprising a lixiviation step
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Melting And Manufacturing (AREA)
- Glass Compositions (AREA)
Description
本発明は紫外線透過率の高い高ケイ酸ガラスの
製法に関する。
SiO2、B2O3およびNa2Oを主成分とするホウケ
イ酸塩ガラスは、一般に熱処理によつて、B2O3
とNa2Oに富む相（酸可溶相）とSiO2に富む相
（酸不溶相）とに分相する。こうして分相したガ
ラスを硫酸、硝酸、塩酸などの鉱酸で処理する
と、酸可溶相が溶出され、SiO2に富む多孔質ガ
ラスが得られ、この多孔質ガラスを焼成すること
によつて高ケイ酸ガラスが得られることは良く知
られている。しかし、こうした高ケイ酸ガラスの
製造法においては、酸可溶相の溶出で形成される
表面、すなわち多孔質ガラスの表面にガラス損壊
の原因となる歪が生じやすい問題がある。
この歪を減少させる手段としては、低濃度の酸
で酸可溶相を溶出させることが有効である旨、大
阪工業試験所報告第355号に記されている。しか
しながら、この方法を採用すると多孔質ガラスの
歪は確かに減少するものの、高濃度の酸で処理し
た場合に比較して、最終的に得られる高ケイ酸ガ
ラスの紫外線透過率が低くなるのが通弊である。
これは低濃度の酸を用いたのではNa+やFe3+など
の不純物を充分に溶出できないことに原因がある
と考えられる。
つまり、上述のような従来技術では歪が少な
く、しかも紫外線透過率が高い高ケイ酸ガラスを
製造することができなかつたのである。
本発明は熱処理によつて分相したホウケイ酸ガ
ラスに鉱酸処理を施すにあたり、その鉱酸処理を
比較的低濃度の鉱酸を使用する第１工程と比較的
高濃度の鉱酸を使用する第２工程で行なうことに
より、前述した歪の発生を最少限に抑えながら、
紫外線透過率の高い高ケイ酸ガラスを得んとする
ものである。
而して本発明に係る高ケイ酸ガラスの製造法
は、SiO2、B2O3およびNa2O主成分とするホウケ
イ酸塩ガラスを熱処理して酸可溶相と酸不溶相と
に分相させた後、これをまず0.5〜2.0規定の鉱酸
で処理し、次いで2.5規定以上の鉱酸で処理し、
得られた多孔質ガラスを焼成することからなる。
本発明の方法において、原料ガラスには例えば
米国特許第2106744号に記載されているようなホ
ウケイ酸塩ガラス使用可能である。このホウケイ
酸塩ガラスは一般には成形物の形で熱処理に付さ
れ、熱可溶相と酸不溶相とに分相せしめられる。
この熱処理は500〜600℃程度の温度で10〜150時
間程度行なわれるのが通例である。
熱処理によつて分相したホウケイ酸塩ガラス
は、次いで鉱酸処理に供せられて酸可溶相が溶出
せしめられるが、本発明によれば、この鉱酸処理
は２工程で行なわれる。第１工程は歪の発生を最
少限にとどめながら、酸可溶相の大部分を溶出さ
せる工程であつて、ここでは0.5〜2.0規定の鉱酸
を使用することを要件とするが、余りに低濃度の
鉱酸を使用すると、酸可溶相の溶出に長時間を要
するので、第１工程で使用する鉱酸の最低濃度は
0.5規定程度であることを可とする。鉱酸として
は硫酸、硝酸および塩酸の少なくとも１種が使用
される。
酸可溶相の溶出に際して生ずる歪の量は、ガラ
ス成形物の内厚に依存し、歪量は肉厚の増加に伴
つて増大する。従つて第１工程で使用する鉱酸の
濃度はガラス成形物の肉厚に応じて調整すること
が好ましく、例えば肉厚４〜７mmのガラスを処理
する場合は、鉱酸の濃度を0.5〜2.0規定の範囲と
するのが適当である。第１工程での処理温度と処
理時間は、処理されるガラスの肉厚および使用す
る鉱酸の濃度にもよるが、一般には85〜100℃、
80〜150時間程度の鉱酸処理で酸可溶相の大部分
を溶出させることができ、これによつて酸処理の
際の歪量を少なくすることができる。尚、鉱酸は
酸可溶相の溶出によつて中和されるので、第１工
程終了時の鉱酸濃度は常に開始時のそれより低い
のが通例である。
第１工程で得られた多孔質ガラスは引き続き第
２工程で第２の鉱酸処理を受ける。この第２工程
は多孔質ガラス中に残存する紫外線吸収原因を排
除する工程であつて、ここでは2.5規定以上の鉱
酸を使用することを要件とするが、余りに高濃度
である必要はなく、2.5〜3.5規定程度の鉱酸が一
般には使用される。鉱酸としては第１工程と同
様、硫酸、硝酸および塩酸の何れもが使用可能で
ある。第２工程で使用する鉱酸には、リン酸およ
び／または酒石酸を添加することが好ましい。リ
ン酸イオンや酒石酸イオンは、紫外線吸収原因と
なる鉄イオンと可溶性の錯イオンを形成するから
である。リン酸および／または酒石酸の添加量
は、多孔質ガラス中に残存する鉄分の量にもよる
が、通常は第２工程で使用される鉱酸の重量基準
で0.5〜５％の範囲を可とする。第２工程の処理
時間と処理温度は、一般に60〜100℃、５〜15時
間程度であつて、これにより紫外線吸収原因が排
除された多孔質ガラスを得ることができる。
第２工程を終了した多孔質ガラスは以後これを
常法通り焼成すれば、本発明の目的物たる紫外線
透過率の高い高ケイ酸ガラスが得られる。
実施例
SiO262.7％、B2O327.1％、Na2O8.2％、
Al2O32.0％、As2O30.3％からなる組成（ただし
As2O3は外割で添加）のガラスを溶融して150mm
×150mm×７mmのガラス板に成形し、このガラス
板を560℃で120時間熱処理して分相させた。この
ガラスには不純物として0.05〜0.1％程度のFe2O3
を含む。この分相ガラス板を次の各方法で処理し
て多孔質ガラスを得た。
(a) 上記の分相ガラス板を95℃に加熱した1.5規
定の硫酸溶液中に100時間保持して酸可溶相を
溶出させた後、このガラス板を30℃のイオン交
換水で24時間洗浄し、多孔質ガラス板を得た。
(b) 上記の分相ガラス板を95℃に加熱した1.5規
定の硫酸溶液中に100時間保持して酸可溶相を
溶出させた後、80℃に加熱した３規定の硫酸溶
液中で24時間保持し、しかる後このガラス板を
40℃のイオン交換水で24時間洗浄して多孔質ガ
ラス板を得た。
(c) 前記(a)の方法で得た多孔質ガラス板を、１％
（重量基準）の正リン酸を添加した95℃の３規
定硫酸溶液中に24時間保持した後、このガラス
板を30℃のイオン交換水で10時間洗浄して多孔
質ガラス板を得た。
(d) 前記(a)の方法で得た多孔質ガラス板を、１％
（重量基準）の酒石酸を添加した90℃の３規定
硫酸溶液中に10時間保持した後、このガラス板
を30℃のイオン交換水で24時間洗浄して多孔質
ガラス板を得た。
(e) 上記の分相ガラス板を95℃に加熱した2.5規
定の硫酸溶液中に124時間保持して酸可溶相を
溶出させた後、このガラス板を30℃のイオン交
換水で24時間洗浄し、多孔質ガラスを得た。
(f) 上記の分相ガラス板を95℃に加熱した2.0規
定の硫酸溶液中に100時間保持して酸可溶相を
溶出させた後、80℃に加熱した2.5規定の硫酸
溶液中に24時間保持し、しかる後このガラス板
を30℃のイオン交換水で24時間洗浄して多孔質
ガラスを得た。
次に(a)〜(f)の各方法で得たそれぞれの多孔質ガ
ラス板を乾燥後、毎時60℃の加温速度で1100℃ま
で加熱し、この温度で２時間保持してから室温ま
で冷却して高ケイ酸ガラスを得た。この際、酸可
溶相の溶出を2.5規定の硫酸溶液で一工程で行つ
て得た(e)の方法の多孔質ガラス板だけには、その
60％に割れまたは破壊が生じた。割れまたは破壊
のないそれぞれの高ケイ酸ガラス板から厚さ2.4
mmの試料を調製し、試料両面を平行に研摩した
後、各試料について分光透過率を測定した。結果
を次表に示す。
The present invention relates to a method for producing high silicate glass with high ultraviolet transmittance. Borosilicate glasses containing SiO 2 , B 2 O 3 and Na 2 O as main components are generally treated with B 2 O 3 by heat treatment.
The phase separates into a phase rich in Na 2 O (acid-soluble phase) and a phase rich in SiO 2 (acid-insoluble phase). When this phase-separated glass is treated with a mineral acid such as sulfuric acid, nitric acid, or hydrochloric acid, the acid-soluble phase is eluted and a porous glass rich in SiO 2 is obtained. By firing this porous glass, high It is well known that silicate glass can be obtained. However, in this method of manufacturing high silicate glass, there is a problem in that the surface formed by the elution of the acid-soluble phase, that is, the surface of the porous glass, tends to be strained, which causes glass breakage. Osaka Industrial Research Institute Report No. 355 states that as a means to reduce this distortion, it is effective to elute the acid-soluble phase with a low concentration of acid. However, although this method does reduce the distortion of the porous glass, the ultraviolet transmittance of the final high-silicate glass will be lower than when treated with high-concentration acid. It's common knowledge.
This is thought to be due to the fact that impurities such as Na + and Fe 3+ cannot be sufficiently eluted using low-concentration acids. In other words, with the above-mentioned conventional techniques, it has not been possible to produce high silicate glass with low distortion and high ultraviolet transmittance. In the present invention, when performing mineral acid treatment on borosilicate glass whose phase has been separated by heat treatment, the mineral acid treatment is performed in a first step using a relatively low concentration of mineral acid and a first step using a relatively high concentration of mineral acid. By performing this in the second step, while minimizing the occurrence of the aforementioned distortion,
The aim is to obtain high silicate glass with high ultraviolet transmittance. Therefore, the method for producing high silicate glass according to the present invention heat-treats borosilicate glass containing SiO 2 , B 2 O 3 and Na 2 O as main components to separate it into an acid-soluble phase and an acid-insoluble phase. After mixing, this is first treated with a mineral acid of 0.5 to 2.0N, then treated with a mineral acid of 2.5N or higher,
It consists of firing the obtained porous glass. In the method of the present invention, the raw glass can be, for example, a borosilicate glass as described in US Pat. No. 2,106,744. The borosilicate glass is generally subjected to a heat treatment in the form of a molded product to separate it into a heat-soluble phase and an acid-insoluble phase.
This heat treatment is usually carried out at a temperature of about 500 to 600°C for about 10 to 150 hours. The borosilicate glass whose phase has been separated by heat treatment is then subjected to mineral acid treatment to elute the acid-soluble phase, and according to the present invention, this mineral acid treatment is carried out in two steps. The first step is to elute most of the acid-soluble phase while minimizing the generation of strain, and here the requirement is to use mineral acid of 0.5 to 2.0N, but if the mineral acid is too low If a certain concentration of mineral acid is used, it will take a long time to elute the acid-soluble phase, so the minimum concentration of mineral acid used in the first step is
Approximately 0.5 standard is acceptable. At least one of sulfuric acid, nitric acid and hydrochloric acid is used as the mineral acid. The amount of strain that occurs during elution of the acid-soluble phase depends on the inner thickness of the glass molded article, and the amount of strain increases as the wall thickness increases. Therefore, it is preferable to adjust the concentration of the mineral acid used in the first step according to the wall thickness of the glass molded product. For example, when processing glass with a wall thickness of 4 to 7 mm, the concentration of the mineral acid is adjusted to 0.5 to 2.0. It is appropriate to keep it within the specified range. The treatment temperature and treatment time in the first step depend on the thickness of the glass to be treated and the concentration of mineral acid used, but are generally 85 to 100℃;
Most of the acid-soluble phase can be eluted by mineral acid treatment for about 80 to 150 hours, thereby reducing the amount of strain during acid treatment. Note that since the mineral acid is neutralized by elution of the acid-soluble phase, the mineral acid concentration at the end of the first step is usually always lower than that at the beginning. The porous glass obtained in the first step is subsequently subjected to a second mineral acid treatment in a second step. This second step is a step to eliminate the cause of ultraviolet absorption remaining in the porous glass, and here it is required to use mineral acid with a concentration of 2.5N or higher, but it does not need to be in an extremely high concentration. Mineral acids of about 2.5 to 3.5 normal are generally used. As the mineral acid, any of sulfuric acid, nitric acid, and hydrochloric acid can be used as in the first step. It is preferable to add phosphoric acid and/or tartaric acid to the mineral acid used in the second step. This is because phosphate ions and tartrate ions form soluble complex ions with iron ions that cause ultraviolet absorption. The amount of phosphoric acid and/or tartaric acid added depends on the amount of iron remaining in the porous glass, but usually it can range from 0.5 to 5% based on the weight of the mineral acid used in the second step. do. The treatment time and temperature of the second step are generally 60 to 100° C. for about 5 to 15 hours, thereby making it possible to obtain porous glass in which the cause of ultraviolet absorption has been eliminated. The porous glass that has undergone the second step is then fired in a conventional manner to obtain high silicate glass with high ultraviolet transmittance, which is the object of the present invention. Example SiO 2 62.7%, B 2 O 3 27.1%, Na 2 O 8.2%,
Composition consisting of 2.0% Al 2 O 3 and 0.3% As 2 O 3 (but
As 2 O 3 is added in the outer layer) glass is melted to 150 mm.
It was formed into a glass plate of 150 mm x 7 mm, and this glass plate was heat-treated at 560° C. for 120 hours to cause phase separation. This glass contains approximately 0.05-0.1% Fe 2 O 3 as an impurity.
including. This phase-separated glass plate was treated by the following methods to obtain porous glass. (a) After holding the above-mentioned phase-separated glass plate in a 1.5 N sulfuric acid solution heated to 95°C for 100 hours to elute the acid-soluble phase, the glass plate was soaked in ion-exchanged water at 30°C for 24 hours. It was washed to obtain a porous glass plate. (b) After holding the above-mentioned phase-separated glass plate in a 1.5N sulfuric acid solution heated to 95°C for 100 hours to elute the acid-soluble phase, it was placed in a 3N sulfuric acid solution heated to 80°C for 24 hours. Hold it for a while and then remove this glass plate.
A porous glass plate was obtained by washing with ion-exchanged water at 40°C for 24 hours. (c) Add 1% of the porous glass plate obtained by the method of (a) above.
After being kept in a 3N sulfuric acid solution at 95°C to which (by weight) orthophosphoric acid was added for 24 hours, the glass plate was washed with ion-exchanged water at 30°C for 10 hours to obtain a porous glass plate. (d) The porous glass plate obtained by the method of (a) above was mixed with 1%
After holding the glass plate in a 3N sulfuric acid solution at 90°C to which (by weight) tartaric acid was added for 10 hours, the glass plate was washed with ion-exchanged water at 30°C for 24 hours to obtain a porous glass plate. (e) After holding the above-mentioned phase-separated glass plate in a 2.5N sulfuric acid solution heated to 95°C for 124 hours to elute the acid-soluble phase, the glass plate was soaked in ion-exchanged water at 30°C for 24 hours. After washing, a porous glass was obtained. (f) After holding the above-mentioned phase-separated glass plate in a 2.0N sulfuric acid solution heated to 95°C for 100 hours to elute the acid-soluble phase, it was placed in a 2.5N sulfuric acid solution heated to 80°C for 24 hours. The glass plate was held for an hour and then washed with ion-exchanged water at 30°C for 24 hours to obtain porous glass. Next, after drying each porous glass plate obtained by each method (a) to (f), it was heated to 1100℃ at a heating rate of 60℃ per hour, kept at this temperature for 2 hours, and then heated to room temperature. After cooling, a high silicate glass was obtained. At this time, only the porous glass plate obtained by method (e) in which the acid-soluble phase was eluted in one step with a 2.5N sulfuric acid solution was used.
60% cracked or fractured. 2.4 thick from each high silicate glass plate without cracking or breaking
mm samples were prepared, both surfaces of the samples were polished in parallel, and the spectral transmittance of each sample was measured. The results are shown in the table below.
【表】
上記の結果から明らかな通り、本発明の方法に
よつて比較的低濃度の鉱酸で酸可溶相を溶出さ
せ、次いで比較的高濃度の鉱酸で処理すれば（(b)
〜(d)、(f)の方法参照）、紫外線透過率の高い高ケ
イ酸ガラスを得ることができる。しかし、第１工
程、第２工程とも2.5規定の鉱酸で処理した場合
には（(e)の方法参照）、紫外線透過率の高いガラ
スが得られるものの、既述した通り、ガラスの収
率が40％と非常に低い。[Table] As is clear from the above results, if the acid-soluble phase is eluted with a relatively low concentration of mineral acid and then treated with a relatively high concentration of mineral acid by the method of the present invention ((b)
(see methods (d) and (f)), high silicate glass with high ultraviolet transmittance can be obtained. However, when both the first and second steps are treated with a 2.5 N mineral acid (see method (e)), a glass with high UV transmittance can be obtained, but as mentioned above, the yield of the glass is low. is very low at 40%.
Claims (1)
酸塩ガラスを熱処理することによつて酸に可溶な
相と酸に下溶な相とに分相させ、しかる後これを
鉱酸で処理することにより酸可溶相を溶出させて
多孔質ガラスとし、次いでこの多孔質ガラスを焼
成して高ケイ酸ガラスを製造する方法において、
前記の鉱酸処理を0.5〜2.0規定の鉱酸を使用する
第１工程と、2.5規定以上の鉱酸を使用する第２
工程の２工程で行なうことを特徴とする紫外線透
過率の高い高ケイ酸ガラスの製造法。 ２ 鉱酸処理の第１および第２工程に硫酸、硝酸
および塩酸の少なくとも１種を使用する特許請求
の範囲第１項記載の方法。 ３ 第２工程で使用する2.5規定以上の鉱酸がリ
ン酸および／または酒石酸を含有する特許請求の
範囲第１項記載の方法。[Claims] 1. By heat-treating borosilicate glass containing SiO 2 , B 2 O 3 , and Na 2 O as main components, it is separated into an acid-soluble phase and an acid-insoluble phase. In a method of manufacturing high silicate glass by eluting the acid-soluble phase by making them compatible and then treating them with a mineral acid to form a porous glass, and then firing this porous glass,
The above mineral acid treatment is performed in the first step using mineral acid of 0.5 to 2.0N, and in the second step using mineral acid of 2.5N or more.
A method for producing high silicate glass with high ultraviolet transmittance, which is characterized in that it is carried out in two steps. 2. The method according to claim 1, wherein at least one of sulfuric acid, nitric acid and hydrochloric acid is used in the first and second steps of mineral acid treatment. 3. The method according to claim 1, wherein the 2.5N or higher mineral acid used in the second step contains phosphoric acid and/or tartaric acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7225381A JPS57188432A (en) | 1981-05-15 | 1981-05-15 | Manufacture of high silicate glass with high ultraviolet transmittance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7225381A JPS57188432A (en) | 1981-05-15 | 1981-05-15 | Manufacture of high silicate glass with high ultraviolet transmittance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57188432A JPS57188432A (en) | 1982-11-19 |
| JPS6149256B2 true JPS6149256B2 (en) | 1986-10-28 |
Family
ID=13483939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7225381A Granted JPS57188432A (en) | 1981-05-15 | 1981-05-15 | Manufacture of high silicate glass with high ultraviolet transmittance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57188432A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1623963B1 (en) | 2003-03-20 | 2011-05-11 | Japan Science and Technology Agency | Process for producing high silicate glass and high silicate glass |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3843341A (en) * | 1972-03-02 | 1974-10-22 | Ppg Industries Inc | Method of making thermally stable and crush resistant microporous glass catalyst supports |
-
1981
- 1981-05-15 JP JP7225381A patent/JPS57188432A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57188432A (en) | 1982-11-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2215039A (en) | Method of treating borosilicate glasses | |
| US3607172A (en) | Tripotassium phosphate treatment for strengthening glass | |
| US3253975A (en) | Glass body having a semicrystalline surface layer and method of making it | |
| DE1239817B (en) | Process for the production of a glass body which has a crystal phase in its surface layers in addition to the glass phase | |
| TWI897359B (en) | Lithium aluminosilicate microcrystalline glass and preparation method thereof | |
| CN103739189B (en) | A kind of preparation method of chemically toughened glass | |
| US3113009A (en) | Method of making and treating a semicrystalline ceramic body | |
| US3317297A (en) | Method of chemically strengthening glass | |
| US3754881A (en) | Art of producing inorganic bodies having at least a surface layer which is semicrystalline | |
| US3549344A (en) | Method of removing tin from the surface of flat glass by double ion exchange | |
| US3149946A (en) | Method of improving the infrared transmittance of high silica glass | |
| US3113855A (en) | Method of increasing annealing point of high silica glass | |
| JPS6149256B2 (en) | ||
| US3116991A (en) | Desalkalinisation of glass | |
| CN117023979B (en) | Alkaline aluminosilicate glass and preparation process and application thereof | |
| GB962633A (en) | Magnetic material and methods of making the same | |
| US3054221A (en) | Opal, 96% silica glass and method of production | |
| US4033775A (en) | Process for producing aluminous keatite ceramics | |
| US3846099A (en) | Glass-ceramic and process therefor | |
| DE1544281B2 (en) | Method for doping silicon semiconductor material | |
| CN101913759A (en) | Process for relieving stress of quartz glass | |
| GB1342674A (en) | Process for production of glass articles with increased and more durable mechanical strength | |
| JPH0132174B2 (en) | ||
| JPH0139974B2 (en) | ||
| JPS61251533A (en) | Porous glass and production thereof |