酒井千尋
Chihiro SAKAI |
最適なオフライン・ヒートソーク試験による安全な強化ガラス
Safety tempered glass after suitable off-line Heat Soak Test
Journal of the Ceramic Society of Japan, Supplement 132 [9] S7-S12 2024. |
Heating conditions of off-line Heat Soak Test have been investigated based
on a lot of studies about nickel sulfide defect included in the tempered
and heat-strengthened glass products. The temperature of the alpha-beta
phase transformation is different with a change of the chemical composition
(sulfur content) of the nickel sulfide crystal. In the case that the nickel
sulfide includes higher than 35.3 wt% of sulfur component, the temperature
of alphabeta phase transformation continuously changes from 379 to 282℃.
There are several thermal conditions for the off-line Heat Soak Test of
the tempered glass. The most reliable heat-treatment condition (260℃+/-10℃)
has been established in ISO 2065 based on EN 14197-1-2016 in 2017. In the
world, a lot of glass manufacturers adopt an old condition (290℃+/-10℃)
of EN 14179-1-2005 in the off-line Heat Soak Test. In the off-line Heat
Soak Test, we must maintain the furnace temperature lower than 270℃ that
was specified in ISO 20657-2017 in order to raise the degree of beta-phase
transformation of nickel sulfide.
＊本文は日本語で記載しています。
|
酒井千尋
Chihiro SAKAI |
強化ガラス自然破損起点の硫化ニッケルのβ相転位分析技術
Analysis of beta-phase transformation of nickel sulfide from the origin of spontaneously fractured tempered glass
Journal of the Ceramic Society of Japan, Supplement 132 [1] S1-S6 2024. |
Analysis technology of beta-phase transformation of nickel sulfide which
was collected from the origin of spontaneously fractured tempered glass
has been quantitatively (and qualitatively) studied by the micro-Raman
spectrometric method. Point analysis by means of the micro-Raman spectrometer
has elucidated the crystallographic information from alpha-phase to beta-phase
of the nickel sulfide. The mapping analysis using confocal micro-Raman
spectrometer has provided us the quantitative analysis of the degree of
beta-phase transformation of the nickel sulfide, newly. The quantification
of the degree of beta-phase transformation enabled the calculation of the
coefficient of volume expansion of the nickel sulfide accompanied with
the beta-phase transformation. The analysis technology by micro-Raman spectrometric
method is very useful for the following problems.
1) Quick presentations of quantitative information for the investigations
of the causes of spontaneous breakage of tempered glass in the glass markets.
2) The quantitative information for the optimization of the thermal history
(temperature and processing time) condition in the Heat Soak Test.
3) Quantitative analysis of the process performance in the current Heat
Soak Test..
＊本文は日本語で記載しています。
|
酒井千尋・長嶋廉仁
Chihiro SAKAI and Yukihito NAGASHIMA |
ガラスに含まれる鉄の価数の定量分析技術
Quantitative analysis of oxidation state of iron included in glass
Journal of the Ceramic Society of Japan, Supplement 131 [11] S1-S7 2023.
|
Quantitative valence analysis of iron included in synthesized glasses has been carried out by using high-resolution X-Ray Fluorescence (XRF) analyzer which attached the high-resolution curved-double analyzing crystals of Si (220). The measurement results of the standard materials of Fe2+ (FeTiO3) and Fe3+ (Fe2O3) have been carefully compared for the peak analysis of provided high-resolution
Fe-Kα profiles. The chemical valences (Fe2+ and Fe3+) of iron component included in the glasses have been quantitatively analyzed
on the basis of multiple peak analysis of Fe-Kα (both Fe-Kα1 and Fe-Kα2). The Fe2+/Fe3+ ratio has been calculated for the glasses which were synthesized under
the different oxidation-reduction conditions.
Additionally, the quantitative valence analysis of sulfur has been also
carried out by using high-resolution XRF analyzer which attached the analyzing
crystals of Ge (111) in order to clarify the relationships with iron component.
Chemical valences (S2- and S6+) of sulfur component were congruent with the chemical valence of iron
component.
Quantitative valence analysis by high-resolution XRF analysis has large
advantages for the sample preparations, the surface analysis and the automated
analysis.
＊本文は日本語で記載しています。
|
酒井千尋・福島 整・伊藤嘉昭・長嶋廉仁・本郷年延
Chihiro SAKAI, Sei FUKUSHIMA, Yoshiaki ITO, Yukihito NAGASHIMA and Toshinobu
HONGO |
二結晶蛍光Ｘ線分析装置を用いたガラス中のイオウ成分原子価分析技術
リガクジャーナル, 54 (2), 1-8, 2023 |
ガラスに含まれるイオウ成分の原子価（価数）の定量分析を行うために、反平行に配置した2枚のGe(111)分光結晶を搭載した広域型二結晶蛍光Ｘ線分析装置を用いて、分析技術の確立のための調査を実施した。本研究でSKαプロファイルを高分解でピーク分離するために、状態標準のプロファイルとして硫化亜鉛ZnS（S2-）、斜方イオウ（S0）、亜硫酸ナトリウNa2SO3（S4+）、および硫酸ストロンチウムNa2SO4（S6+）の実測スペクトルを用いた。これらの測定からSKα（SKα1とSKα2）に対して多重ピーク分離が可能になり、ガラスに含まれるイオウ成分に対してS2-とS6+の原子価の定量的な分析が可能となった。その結果、著者らはガラス試料に含まれるイオウ成分の酸化・還元の状態と原子価の関係を明らかにし、ガラスに含まれるイオウ成分の化学的な原子価がガラスの表面とその内部で異なることを示した。非破壊での高分解能蛍光Ｘ線分析法によるイオウ成分の原子価の定量分析は、ガラスの熔融や加熱の過程での酸化・還元状態の定量的な変化を明らかにすることができる。
|
| Chihiro SAKAI |
"Advanced technology for in-line continuous heat soak test of tempered sheet glass to guarantee high reliability"
Glass Technol.: Eur. J. Glass Sci. Technol. A, February, 61 (1), 16–24, 2020.. |
Advanced heat soak test (HST) technology, the ‘in-line continuous HST’has
been reported on the basis of experimental investigations and the T-T-T
(time–temperature–transformation) relationship. The new HST technology
is continuously carried out just after tempering (and heat strengthening)
process. It was registered in ISO-20657 (2017). High temperature microscopy
observations, high temperature x-ray diffractometry, differential thermal
analysis, and micro-Raman spectrometry have been carried out in order to
elucidate the α–β phase transformation of nickel sulphide in detail. The
breakage ratio of in-line continuous HST is the same as that of conventional
off-line HST or excellent. The ‘in-line continuous HST’ is already operating
in a Japanese glass plant in order to produce tempered (and heat strengthened)
sheet glass with high safety and reliability. The in-line continuous HST
technology has the following benefits: (a) improvements of both productivity
and reliability, (b) automatic inspection just after the tempering–quenching
process, and (c) improvements to productive performance (many kinds products,
heteromorphic products, and mass production). In this technical report,
the advanced ‘in-line continuous HST’ technology which was standardised
by several experimental investigations and analytical results will be shown
in detail. The effective and efficient manufacturing technology of the
tempered (and heat strengthened) sheet glass will be introduced.
|
酒井千尋・佐藤良司
Chihiro SAKAI & Ryoji SATO |
「オフライン・ヒートソーク試験の低温処理化の可能性」
"Possibility of low-temperature processing of off-line heat soak test"
Journal of the Ceramic Society of Japan, Supplement 128 [7] S1-S7 2020. |
Processing conditions of two kinds of heat soak tests (off-line heat soak
test and in-line continuous heat soak test) which were standardized in
ISO20657_2017 were compared in detail. Several experimental investigations
(high temperature optical microscope observations, micro-Raman spectrometry,
high-temperature powder X-rays Diffractometry, and Differential Thermal
Analysis) were carried out in order to improve the processing conditions
(thermal history) of the off-line heat soak test. These experimental investigations
indicated that beta-phase transformation of nickel sulfide in the glass
products was completed during the heating process of the off-line heat
soak test, in the case of low-heating rate of 3 °C/min. It was shown that
we could shift the holding temperature of the off-line heat soak test to
the temperatures lower than 260 °C (+/-10 °C) which was described in ISO20657
based on the detailed investigations. The improved time-temperature conditions
during the holding phase are as follows.
1) Holding phase commences when the surface temperature of all glasses has reached 240 °C.
2) Glass temperature is maintained in the range of 240 °C (+/-20 °C) during
holding phase.
3) The glasses are held for 15 min or longer in the furnace.
In the low-temperature processing of off-line heat soak test, we can improve the productivity of the safe tempered sheet glass, and realize the energy
saving.
＊本文は日本語で記載しています。.
|
酒井千尋
Chihiro SAKAI |
「第73 回日本セラミックス協会技術賞を受賞して
高信頼性強化板ガラス製造ためのインライン連続式ソーク技術の開発と実用化」
"Development of In-line Continuous Heat Soak Test for High Reliability
of Tempered Sheet Glass"
セラミックス 54, 424-425, 2019. |
本技術は，筆者が高温顕微鏡を用いてガラス中の硫化ニッケルのα-β相転移の観察の過程で気が付いた現象から構築された．そして，この相転移の現象が温度の上昇と下降に対して可逆的であるとわかり，インライン連続ヒートソーク試験の温度と時間の条件の最適化につながった．
ヒートソーク試験技術は，強化板ガラスの製品から硫化ニッケル異物を除去するための最終手段であるので，同時に板ガラスの製品に硫化ニッケル異物の流出をさせない対策も必要である．原料に含まれる不純物の除去，製造工程でのニッケルを含むステンレス金属の排除，あるいは製造現場での注意喚起等，総合的な改善によって強化板ガラスの品質と信頼性は向上するものと考えている．
|
酒井千尋
Chihiro SAKAI |
「風冷強化ガラスと自然破損」
"Spontaneous breakage of tempered glass"
NEW GLASS Vol．23, 25-31, 2008. |
風冷強化板ガラス中に含まれるφ１００μm レベルの微小な異物による自然破損は，強化板ガラスの用途拡大や安全上の観点から特に近年大きな課題となっている。しかしながら，この数年間で，特に欧州と日本国内を中心として，硫化ニッケル異物による強化板ガラスの自然破損の対策は，その根本的な原因解明と理論的な破損メカニズムの解析などに基づいて大いに進んだと感じられる。特に，日本国内においても，１９９９年頃から本格的に硫化ニッケルの結晶構造に起因する相転移の現象を明確に示して，それらの相転移を顧客に出荷するまでに先に起こさせて不良品を除去する技術が進んできた（ソーク処理技術）。また，欧州においても，大手のガラスメーカーを中心に，標準的な処理方法が提案され，現在では欧州標準へとまとまっている。
このような強化板ガラスの自然破損に対する対策は，今後もさらに製品の信頼性向上のために進むことが予測される。風冷強化板ガラスの自然破損に対しては，上記の硫化ニッケル以外にも様々な溶解欠点に起因する原因がある。今後は，直接的な破損原因としての寄与は低いものの，このような欠点に対する対策も応用展開しながら，風冷強化板ガラスの自然破損が市場でゼロになることを目指して行きたいと考えている。
|