JP6885002B2 - Opaque quartz glass - Google Patents
Opaque quartz glass Download PDFInfo
- Publication number
- JP6885002B2 JP6885002B2 JP2016155361A JP2016155361A JP6885002B2 JP 6885002 B2 JP6885002 B2 JP 6885002B2 JP 2016155361 A JP2016155361 A JP 2016155361A JP 2016155361 A JP2016155361 A JP 2016155361A JP 6885002 B2 JP6885002 B2 JP 6885002B2
- Authority
- JP
- Japan
- Prior art keywords
- quartz glass
- powder
- opaque quartz
- image
- pore
- 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.)
- Active
Links
Images
Landscapes
- Glass Melting And Manufacturing (AREA)
Description
本発明は、赤外光の遮光性に優れ、光学的に高均質な不透明石英ガラスに関する。 The present invention relates to opaque quartz glass which is excellent in light blocking property of infrared light and is optically highly homogeneous.
不透明石英ガラスは熱遮断性を要する用途に使用される。熱遮断性は赤外光の遮光性と関係があり、遮光性が高い不透明石英ガラスほど熱遮断性に優れている。 Opaque quartz glass is used in applications that require heat insulation. The heat-shielding property is related to the light-shielding property of infrared light, and the opaque quartz glass having a higher light-shielding property has a better heat-blocking property.
従来、不透明石英ガラスの製造方法としては、結晶質シリカまたは非晶質シリカに窒化珪素等の発泡剤を添加して溶融する方法（例えば、特許文献１〜３参照）などが知られている。しかしながら、このような製造方法で製造された不透明石英ガラスでは、発泡剤が気化して気孔を形成するため気孔の平均径が大きく、実用にたえる強度をもつものでは気孔の含有密度が低くなり、赤外光の遮光性が低下するという問題がある。
Conventionally, as a method for producing opaque quartz glass, a method of adding a foaming agent such as silicon nitride to crystalline silica or amorphous silica and melting the glass (see, for example,
一方、発泡剤を添加することなく、非晶質シリカ粉末の成形体をその溶融温度以下の温度で加熱し、完全に緻密化する前に熱処理を中断し、部分的に焼結する方法（例えば、特許文献４参照）も提案されている。このような製造方法で製造された不透明石英ガラスでは、気孔の平均径を小さくすることが可能であるが、気孔が閉気孔となるまで焼結させると気孔の含有密度が低くなり赤外光の遮光性が低下するという問題や、気孔の平均径が小さくなりすぎ長波長の赤外光の遮光性が低下するという問題がある。また、本方法では電気炉内の温度分布によって、不透明石英ガラスの焼結体内に密度分布が生じやすく、大型サイズで均質な不透明石英ガラスを得ることは難しいという問題もある。 On the other hand, a method in which a molded product of amorphous silica powder is heated at a temperature equal to or lower than its melting temperature without adding a foaming agent, the heat treatment is interrupted before it is completely densified, and the molded product is partially sintered (for example,). , Patent Document 4) has also been proposed. In opaque quartz glass manufactured by such a manufacturing method, it is possible to reduce the average diameter of the pores, but if the pores are sintered until they become closed pores, the pore content density becomes low and infrared light is emitted. There is a problem that the light-shielding property is lowered, and there is a problem that the average diameter of the pores becomes too small and the light-shielding property of long-wavelength infrared light is lowered. Further, in this method, there is a problem that a density distribution is likely to occur in the sintered body of the opaque quartz glass due to the temperature distribution in the electric furnace, and it is difficult to obtain a large-sized and homogeneous opaque quartz glass.
また、石英ガラス多孔質体を高圧条件下で加熱焼成する方法（例えば、特許文献５参照）も提案されているが、このような製造方法で製造された不透明石英ガラスでは、波長２００〜５０００ｎｍの光の透過率が０．５〜２．０％となっており、長波長側の赤外光の遮光性が低下するという問題がある。また、本方法は高圧焼成を行うため特殊な装置が必要であり、簡易な方法とは言えない。 Further, a method of heating and firing a porous quartz glass body under high pressure conditions (see, for example, Patent Document 5) has also been proposed, but an opaque quartz glass manufactured by such a manufacturing method has a wavelength of 200 to 5000 nm. The transmittance of light is 0.5 to 2.0%, and there is a problem that the light blocking property of infrared light on the long wavelength side is lowered. In addition, this method requires a special device for high-pressure firing, and cannot be said to be a simple method.
本発明の目的は、赤外光の遮光性に優れ、光学的に高均質な不透明石英ガラスを提供することである。 An object of the present invention is to provide an opaque quartz glass which is excellent in light-shielding property of infrared light and which is optically highly homogeneous.
本発明者らは、鋭意検討の結果、非晶質シリカ粉末と造孔剤粉末（以下、単に造孔剤と言うことがある）を、非晶質シリカ凝集体を低減するように混合し、前記混合粉末を成形したのち、所定の温度で焼結することによって、気孔を均一に形成した不透明石英ガラスを得ることができることを見出し、本発明を完成するに至った。なお、非晶質シリカ凝集体とは非晶質シリカ粉末と造孔剤粉末の混合が不十分な場合、非晶質シリカ粉末中に造孔剤が均一に分散せず、混合粉末全体で俯瞰した場合に非晶質シリカのみで局所的に一定上の大きさで存在することを表すものである。またここで、得られる不透明石英ガラスは均一な気孔を有する、すなわち、ガラス全体を俯瞰した場合に局所的に気孔の密度が低く、シリカ密度が高い部分が極めて少ない。そのために当該不透明石英ガラスが光学的に高い均質性を有することを見出した。 As a result of diligent studies, the present inventors have mixed amorphous silica powder and pore-forming agent powder (hereinafter, may be simply referred to as pore-forming agent) so as to reduce amorphous silica aggregates. We have found that opaque quartz glass having uniformly formed pores can be obtained by molding the mixed powder and then sintering it at a predetermined temperature, and have completed the present invention. What is the amorphous silica agglomerate? When the mixture of the amorphous silica powder and the pore-forming agent powder is insufficient, the pore-forming agent is not uniformly dispersed in the amorphous silica powder, and the entire mixed powder has a bird's-eye view. In this case, it means that only amorphous silica is locally present in a certain size. Further, here, the obtained opaque quartz glass has uniform pores, that is, when the entire glass is viewed from a bird's-eye view, the pore density is locally low and the silica density is extremely small. Therefore, it has been found that the opaque quartz glass has high optical homogeneity.
以下、本発明をさらに詳しく説明する。 Hereinafter, the present invention will be described in more detail.
本発明の不透明石英ガラスは、均一な気孔を有する、すなわち、ガラス全体を俯瞰した場合に局所的に気孔の密度が低く、シリカ密度が高い部分が極めて少ない。そのために本発明の不透明石英ガラスは光学的に高い均質性を有する。特に本発明の不透明石英ガラスは局所的に赤外光を透過する部分が極めて少なく、加熱装置の部材等に好適に用いることが可能である。光学的に高均質なことは後述の画像処理法により得られるパラメーターにより示すことができる。 The opaque quartz glass of the present invention has uniform pores, that is, when the entire glass is viewed from a bird's-eye view, the pore density is locally low and the silica density is extremely small. Therefore, the opaque quartz glass of the present invention has high optical homogeneity. In particular, the opaque quartz glass of the present invention has extremely few portions that locally transmit infrared light, and can be suitably used as a member of a heating device or the like. The optical high homogeneity can be shown by the parameters obtained by the image processing method described later.
本発明は、画像処理によって得られるヒストグラムで、可視光が透過している部分とそれ以外に分かれるように閾値を設定して二値化し、閾値を超えた部分のうち０．０４ｍｍ２以上の面積を有する部分（以下、「白抜け」という。）の個数をｍ、画像全体の面積をＲｃｍ２ として、ｍ／Ｒが５０以下であることを特徴とする不透明石英ガラスに関するものである。ここで、不透明石英ガラスにおける白抜けとは可視光が透過する、一定上の大きさの部位を示す。 The present invention is a histogram obtained by the image processing, 0.04 mm 2 or more areas of the part and binarized by setting the threshold value to divide otherwise, parts exceeding the threshold visible light is transmitted through The present invention relates to an opaque quartz glass having a m / R of 50 or less, where m is the number of portions having the above (hereinafter referred to as “white spots”) and the area of the entire image is Rcm 2. Here, the white spot in the opaque quartz glass indicates a portion having a certain size on which visible light is transmitted.
本発明において、画像処理に供する画像は、一般的な光学顕微鏡を用いて不透明石英ガラスを観察して得られた画像を例示でき、観察倍率は×５０で行うことが好ましい。画像処理に供する画像は光学顕微鏡５０倍の観察像を用いて、少なくともその１／４以上の範囲を対象として選択すれば十分な精度で解析できる。 In the present invention, the image to be subjected to image processing can be an example of an image obtained by observing opaque quartz glass using a general optical microscope, and the observation magnification is preferably × 50. The image to be used for image processing can be analyzed with sufficient accuracy by using an observation image of 50 times with an optical microscope and selecting a range of at least 1/4 or more of the observation image.
また、光学顕微鏡は、画像処理ソフトがインストールされたパソコンと接続されていることが好ましい。これにより観察像を撮影後、すぐにパソコン上で画像処理を行うことができる。 Further, it is preferable that the optical microscope is connected to a personal computer on which image processing software is installed. As a result, image processing can be performed on the personal computer immediately after the observation image is taken.
画像処理は市販のソフトまたはフリーソフトの少なくともいずれかで行えばよく、ＩｍａｇｅＪ １．４６などのフリーソフトを例示できる。具体的な手順は実施例の記載を参照のこと。画像処理ソフトは特定の閾値を基準として画像を白黒に変換（二値化）することができれば十分であり、画像の全体又は一部を選択し、その範囲内において、縦軸を画素の個数、横軸を輝度値としたヒストグラムを描くことが可能であれば好ましい。ヒストグラムの例を図１に示す。 Image processing may be performed with at least commercially available software or free software, and free software such as ImageJ 1.46 can be exemplified. For the specific procedure, refer to the description of the examples. It is sufficient for the image processing software to be able to convert (binarize) the image into black and white based on a specific threshold value, select the whole or part of the image, and within that range, the vertical axis is the number of pixels. It is preferable if it is possible to draw a histogram with the horizontal axis as the brightness value. An example of the histogram is shown in FIG.
本願では、前述の画像処理により得られるヒストグラムが対象とする不透明石英ガラスの観察画像の対象範囲において、光学的に完全に均質であれば、ヒストグラムは正規分布を描くものと仮定できるものとする。その正規分布から外れるほど大きな輝度を有する部分があれば、当該部分とそれ以外の部分とで画像を二値化し、白黒表示した後、輝度の大きな部分が連続して存在し、かつ、所定の面積を超える大きさである部分を白抜け部とし、その個数を前述のｍとして決定することができる。 In the present application, it can be assumed that the histogram draws a normal distribution if it is optically perfectly homogeneous in the target range of the observation image of the opaque quartz glass to which the histogram obtained by the above image processing is the target. If there is a portion having such a large brightness that it deviates from the normal distribution, the image is binarized between the portion and the other portion, and after displaying in black and white, the portion having a large brightness continuously exists and is predetermined. A portion having a size exceeding the area can be defined as a white spot, and the number thereof can be determined as m as described above.
閾値の決定は、以下のように行うことで十分である。すなわち、図２に示すように実際に得られたヒストグラムにおいて、最大の画素の個数を示す輝度がａ、最小の画素の個数を示す輝度のうち、より低い輝度がｂである場合、その輝度の範囲が２×（ａ−ｂ）である正規分布を仮定する。このような場合、正規分布は輝度がｂから、ａ＋ａ−ｂ、（すなわち２ａ−ｂ）の範囲で存在することになる。この輝度２ａ−ｂを閾値とし、画像を二値化する。この二値化した画像を処理することで白抜け部を特定することができる。具体的には、二値化後、２ａ−ｂ以上の輝度の部分のうち、所定の面積以上の部分を白抜け部とする。 It is sufficient to determine the threshold value as follows. That is, in the histogram actually obtained as shown in FIG. 2, when the brightness indicating the maximum number of pixels is a and the brightness indicating the minimum number of pixels is b, the lower brightness is b. Assume a normal distribution with a range of 2 × (ab). In such a case, the normal distribution exists in the range of luminance from b to a + ab, (that is, 2ab). The brightness 2a-b is used as a threshold value, and the image is binarized. By processing this binarized image, the white spot can be specified. Specifically, after binarization, a portion having a brightness of 2 ab or higher and having a predetermined area or more is defined as a white spot.
本願の不透明石英ガラスは、試料厚さ１ｍｍのときの波長１．５μｍから５μｍにおける透過率が１％以下であることが好ましい。これにより加熱装置の部材等により好適に用いることが可能である。 The opaque quartz glass of the present application preferably has a transmittance of 1% or less at a wavelength of 1.5 μm to 5 μm when the sample thickness is 1 mm. As a result, it can be suitably used as a member of a heating device or the like.
本願の不透明石英ガラスは、試料厚さ１ｍｍのときの波長３μｍから５μｍにおける透過率が０．５％以下であることが好ましい。これにより加熱装置の部材等により好適に用いることが可能である。 The opaque quartz glass of the present application preferably has a transmittance of 0.5% or less at a wavelength of 3 μm to 5 μm when the sample thickness is 1 mm. As a result, it can be suitably used as a member of a heating device or the like.
次に、本発明の不透明石英ガラスの製造方法について説明する。 Next, the method for producing the opaque quartz glass of the present invention will be described.
本発明の不透明石英ガラスの製造方法は、非晶質シリカ粉末と造孔材粉末の混合粉末を原料とし、前記混合粉末から、画像処理によって得られるヒストグラムで、各輝度値に対する画素数が最も大きい輝度値を閾値に設定して二値化し、閾値を超えた部分のうち０．０４ｍｍ２以上の面積を有する部分の個数をｎ、画像全体の面積をＳｃｍ２ として、ｎ／Ｓが１００以下であることを特徴とする。 The method for producing opaque quartz glass of the present invention uses a mixed powder of amorphous silica powder and pore-forming material powder as a raw material, and is a histogram obtained by image processing from the mixed powder, and has the largest number of pixels for each luminance value. The brightness value is set as a threshold value and binarized, and the number of parts having an area of 0.04 mm 2 or more among the parts exceeding the threshold value is n, the area of the entire image is Scm 2 , and n / S is 100 or less. It is characterized by being.
本発明の製造方法において、画像処理に供する混合粉末の画像は、一般的な光学顕微鏡を用いて不透明石英ガラスを観察して得られた画像を例示でき、観察倍率は×５０で行うことが好ましい。光学顕微鏡は反射型顕微鏡でもよい。例えば、非晶質シリカ粉末と造孔材の混合粉末を両側から、粉末層の厚みが約０．５〜１．５ｍｍになるように石英ガラス板で挟み、反射型顕微鏡で画像を撮影する方法が例示できる。 In the production method of the present invention, the image of the mixed powder to be subjected to image processing can be exemplified by an image obtained by observing opaque quartz glass using a general optical microscope, and the observation magnification is preferably × 50. .. The optical microscope may be a reflective microscope. For example, a method in which a mixed powder of amorphous silica powder and a pore-forming material is sandwiched between quartz glass plates so that the thickness of the powder layer is about 0.5 to 1.5 mm from both sides, and an image is taken with a reflective microscope. Can be exemplified.
また、光学顕微鏡は、画像処理ソフトがインストールされたパソコンと接続されていることが好ましい。これにより観察像を撮影後、すぐにパソコン上で画像処理を行うことができる。 Further, it is preferable that the optical microscope is connected to a personal computer on which image processing software is installed. As a result, image processing can be performed on the personal computer immediately after the observation image is taken.
混合粉末の画像処理は、閾値を最大の画素の個数を示す輝度としたこと以外は不透明石英ガラスの場合と同様の処理を行えばよい。 The image processing of the mixed powder may be performed in the same manner as in the case of opaque quartz glass except that the threshold value is set to the brightness indicating the maximum number of pixels.
以下、本発明の不透明石英ガラスの製造方法について工程ごとに詳細に説明する。なお全工程に言えることであるが、工程中に不純物汚染が起こらぬように、使用する装置などについて充分に選定する必要がある。 Hereinafter, the method for producing the opaque quartz glass of the present invention will be described in detail for each step. As can be said for all processes, it is necessary to sufficiently select the equipment to be used so that impurity contamination does not occur during the process.
（１）原料粉末の選定
まず、本発明で用いる非晶質シリカ粉末を選定する。非晶質シリカ粉末の製造方法はとくに限定されないが、例えばシリコンアルコキシドの加水分解によって製造された非晶質シリカ粉末や、四塩化珪素を酸水素炎等で加水分解して作製した非晶質シリカ粉末等を用いることができる。また、石英ガラスを破砕した粉末も用いることができる。
(1) Selection of raw material powder First, the amorphous silica powder used in the present invention is selected. The method for producing the amorphous silica powder is not particularly limited, but for example, the amorphous silica powder produced by hydrolyzing silicon alkoxide or the amorphous silica produced by hydrolyzing silicon tetrachloride with a hydrogen acid flame or the like. Powder or the like can be used. Further, a powder obtained by crushing quartz glass can also be used.
本発明で使用する非晶質シリカ粉末の平均粒径は、２０μｍ以下が好ましい。粒径が大きすぎると、焼結に高温、長時間を要するため好ましくない。各種製造法で作製された非晶質シリカ粉末は、ジェットミル、ボールミル、ビーズミル等で粉砕、分級することで上記粒径に調整することができる。 The average particle size of the amorphous silica powder used in the present invention is preferably 20 μm or less. If the particle size is too large, sintering requires high temperature and a long time, which is not preferable. The amorphous silica powder produced by various production methods can be adjusted to the above particle size by pulverizing and classifying with a jet mill, a ball mill, a bead mill or the like.
次に、本発明で用いる造孔剤粉末を選定する。本発明の造孔剤の粒径は不透明石英ガラスの平均気孔径と深く関係し、得たい平均気孔径と同等あるいはそれ以上の粒径の造孔剤を用いる必要がある。気孔径以上の粒径の造孔剤を用いる理由は、造孔剤の消失後の焼結段階において、気孔が当初のサイズよりも小さくなる場合があるためである。造孔剤として黒鉛またはアモルファスカーボンの球状粉末を用いる場合、平均気孔径５〜２０μｍの不透明石英ガラスを得るためには、造孔剤の粒径は５〜４０μｍであることが好ましく、９〜３０μｍであることがより好ましい。 Next, the pore-forming agent powder used in the present invention is selected. The particle size of the pore-forming agent of the present invention is closely related to the average pore size of the opaque quartz glass, and it is necessary to use a pore-forming agent having a particle size equal to or larger than the average pore size to be obtained. The reason for using a pore-forming agent having a particle size larger than the pore diameter is that the pores may become smaller than the initial size in the sintering stage after the pore-forming agent disappears. When a spherical powder of graphite or amorphous carbon is used as the pore-forming agent, the particle size of the pore-forming agent is preferably 5 to 40 μm, preferably 9 to 30 μm, in order to obtain opaque quartz glass having an average pore diameter of 5 to 20 μm. Is more preferable.
本発明の造孔剤の種類は、非晶質シリカの焼結温度以下の温度で熱分解して気化し消失するものであれば特に限定されず、黒鉛粉末やアモルファスカーボン粉末、フェノール樹脂粉末、アクリル樹脂粉末、ポリスチレン粉末などを使用することができる。このうち、黒鉛粉末またはアモルファスカーボン粉末は熱分解の際に発生するガス成分が無害、無臭であるという点で好ましい。 The type of the pore-forming agent of the present invention is not particularly limited as long as it is thermally decomposed and vaporized and disappears at a temperature equal to or lower than the sintering temperature of amorphous silica, and polystyrene powder, amorphous carbon powder, phenol resin powder, etc. Acrylic resin powder, polystyrene powder and the like can be used. Of these, graphite powder or amorphous carbon powder is preferable in that the gas component generated during thermal decomposition is harmless and odorless.
本発明で使用する非晶質シリカ粉末と造孔剤粉末の純度は、９９．９％以上であることが望ましい。石英ガラスにアルカリ金属元素、アルカリ土類元素、遷移金属元素などの不純物元素が高濃度に含まれている場合、おおよそ１３００℃以上の温度において、石英ガラス中にクリストバライトが発生する。クリストバライトは２３０〜３００℃の温度で高温型から低温型へ相転移し体積収縮を起こす。不透明石英ガラスに含有するクリストバライト量が２％より多い場合は、この体積収縮が原因で焼成体内にクラックが発生する傾向がある。特に焼成体が大型の場合、例えば直径１４０ｍｍ以上の不透明石英ガラスにおいてこの傾向は顕著である。非晶質シリカ粉末と造孔剤粉末の純度が低い場合は、純化処理を行なうとよい。純化の方法は特に限定されず、薬液処理や乾式ガス精製、高温焼成による不純物の蒸散などを行うことができる。なお、不透明石英ガラス中に含まれる金属不純物量が少ない場合であっても、水分量や炉内の雰囲気、炉材の純度、焼成時間などによってクリストバライトが多く発生する場合がある点についても言及しておく。 The purity of the amorphous silica powder and the pore-forming agent powder used in the present invention is preferably 99.9% or more. When the quartz glass contains an impurity element such as an alkali metal element, an alkaline earth element, and a transition metal element at a high concentration, Christovalite is generated in the quartz glass at a temperature of about 1300 ° C. or higher. Cristobalite undergoes a phase transition from a high temperature type to a low temperature type at a temperature of 230 to 300 ° C. and causes volume shrinkage. When the amount of cristobalite contained in the opaque quartz glass is more than 2%, cracks tend to occur in the fired body due to this volume shrinkage. This tendency is particularly remarkable when the fired body is large, for example, in opaque quartz glass having a diameter of 140 mm or more. When the purity of the amorphous silica powder and the pore-forming agent powder is low, it is advisable to perform a purification treatment. The purification method is not particularly limited, and it is possible to carry out chemical treatment, dry gas purification, evaporation of impurities by high-temperature firing, and the like. It should be noted that even if the amount of metal impurities contained in the opaque quartz glass is small, a large amount of cristobalite may be generated depending on the amount of water, the atmosphere in the furnace, the purity of the furnace material, the firing time, etc. Keep it.
本発明の造孔剤の形状は非晶質シリカ粉末と均質に混合することができる点、加圧によって粉末を成形する際に圧力伝達を良好に行うことができる点で球状であることが好ましく、その粒子の長軸と短軸の比率を表すアスペクト比が３．０以下であること好ましい。 The shape of the pore-forming agent of the present invention is preferably spherical in that it can be mixed homogeneously with the amorphous silica powder and that pressure transmission can be performed well when the powder is formed by pressurization. The aspect ratio representing the ratio of the major axis to the minor axis of the particles is preferably 3.0 or less.
（２）原料粉末の混合
次に、選定した非晶質シリカ粉末及び造孔剤粉末を混合する。造孔剤粉末の添加量は、非晶質シリカ粉末に対して体積比で０．０４以上となるように混合する必要があるが、好ましい範囲は造孔剤の種類、平均粒径によって異なり、造孔剤粉末が平均粒径５〜４０μｍの黒鉛粉末又はアモルファスカーボン粉末であれば、非晶質シリカ粉末との体積比で０．０４〜０．３５であることが好ましい。造孔剤粉末の添加量が少ないと、不透明石英ガラスに含まれる気孔量が少なくなり赤外光の遮光性が低下するため好ましくない。一方、添加量が多すぎると、不透明石英ガラスの密度が低くなりすぎるため好ましくない。
(2) Mixing of raw material powder Next, the selected amorphous silica powder and pore-forming agent powder are mixed. The amount of the pore-forming agent powder added needs to be mixed so as to be 0.04 or more in volume ratio with respect to the amorphous silica powder, but the preferable range varies depending on the type of the pore-forming agent and the average particle size. When the pore-forming agent powder is a graphite powder or an amorphous carbon powder having an average particle size of 5 to 40 μm, the volume ratio with the amorphous silica powder is preferably 0.04 to 0.35. If the amount of the pore-forming agent powder added is small, the amount of pores contained in the opaque quartz glass is small and the light-shielding property of infrared light is lowered, which is not preferable. On the other hand, if the amount added is too large, the density of the opaque quartz glass becomes too low, which is not preferable.
非晶質シリカ粉末と造孔剤粉末の混合方法は、混合粉末において非晶質シリカ凝集体の単位面積当たりの個数密度が１００個／ｃｍ２以下となる方法であれば、特に限定されず、ロッキングミキサー、クロスミキサー、ポットミル、ボールミル、ふるい等を用いることができる。特に本発明の混合には、ふるいを通して混合する方法を用いると、容易に非晶質シリカ凝集体の単位面積当たりの個数密度を低減させる粉末を得ることができる点で好ましい。 The method for mixing the amorphous silica powder and the pore-forming agent powder is not particularly limited as long as the number density of the amorphous silica aggregates per unit area in the mixed powder is 100 pieces / cm 2 or less. A locking mixer, a cross mixer, a pot mill, a ball mill, a sieve and the like can be used. In particular, when the method of mixing through a sieve is used for the mixing of the present invention, it is preferable in that a powder having a reduced number density per unit area of amorphous silica aggregates can be easily obtained.
（３）混合粉末の成形
次に、混合粉末を成形する。成形方法は、鋳込み成型法、冷間静水圧プレス（ＣＩＰ）法、金型プレス法等の乾式プレスを用いることができる。特に本発明の成型には、ＣＩＰ法を用いると、工程が少なく容易に成形体を得ることができる点で好ましい。さらにＣＩＰ法を用いて、円板形状や円筒形状、リング形状の成形体を作製する方法としては、特に限定しないが、発泡スチロールのような塑性変形可能な鋳型を用いる成形法（例えば、特開平４−１０５７９７参照）や、底板が上パンチよりも圧縮変形の少ない材料で構成されている組立式型枠を用いる方法（例えば、特開２００６−２４１５９５参照）で成形することが可能である。
(3) Molding of mixed powder Next, the mixed powder is molded. As a molding method, a dry press such as a casting molding method, a cold hydrostatic press (CIP) method, or a die pressing method can be used. In particular, when the CIP method is used for the molding of the present invention, it is preferable in that the number of steps is small and the molded product can be easily obtained. Further, the method for producing a disk-shaped, cylindrical-shaped, or ring-shaped molded body by using the CIP method is not particularly limited, but is a molding method using a plastically deformable mold such as Styrofoam (for example, JP-A-4). (Refer to -105797), or by a method using an assembly type form whose bottom plate is made of a material having less compression deformation than the upper punch (see, for example, Japanese Patent Application Laid-Open No. 2006-241595).
（４）成形体の焼結
次に、上記の方法により成形した成形体を所定の温度で加熱し、成形体内に含まれる造孔剤を消失させる。加熱温度は造孔剤の種類によって異なるが、例えば造孔剤として黒鉛粉末やアモルファスカーボンを用いる場合、加熱温度は７００℃から１０００℃で行う。
(4) Sintering of the molded product Next, the molded product molded by the above method is heated at a predetermined temperature to eliminate the pore-forming agent contained in the molded product. The heating temperature varies depending on the type of pore-forming agent. For example, when graphite powder or amorphous carbon is used as the pore-forming agent, the heating temperature is 700 ° C. to 1000 ° C.
造孔剤の消失のための加熱は造孔剤の種類や造孔剤の添加量、成形体のサイズ、加熱温度によって任意の時間行われるが、例えば造孔剤として黒鉛粉末やアモルファスカーボンを用い、添加量が非晶質シリカ粉末との体積比で０．１〜０．２、成形体の体積が２×１０３ｃｍ３、加熱温度が８００℃の場合、加熱時間は２４時間から１００時間で行う。 Heating for the disappearance of the pore-forming agent is performed for an arbitrary time depending on the type of the pore-forming agent, the amount of the pore-forming agent added, the size of the molded body, and the heating temperature. For example, graphite powder or amorphous carbon is used as the pore-forming agent. When the addition amount is 0.1 to 0.2 in volume ratio with the amorphous silica powder, the volume of the molded body is 2 × 10 3 cm 3 , and the heating temperature is 800 ° C., the heating time is 24 hours to 100 hours. Do it with.
次に、造孔剤が消失した成形体を所定の温度で、焼結体に含まれる気孔が閉気孔となるまで焼成する。焼成温度は１３５０〜１５００℃であることが好ましい。焼成温度が１３５０℃より低いと、気孔が閉気孔となるまでに長時間の焼成が必要となるため好ましくない。焼成温度が１５００℃を超えると、焼成体内に含まれるクリストバライト量が多くなり、クリストバライトの高温型から低温型への相転移に伴う体積収縮によって、焼成体にクラックが発生する恐れがあり好ましくない。 Next, the molded product from which the pore-forming agent has disappeared is fired at a predetermined temperature until the pores contained in the sintered body become closed pores. The firing temperature is preferably 1350 to 1500 ° C. If the firing temperature is lower than 1350 ° C., firing for a long time is required before the pores become closed, which is not preferable. When the firing temperature exceeds 1500 ° C., the amount of cristobalite contained in the fired body increases, and the volume shrinkage of cristobalite accompanying the phase transition from the high temperature type to the low temperature type may cause cracks in the fired body, which is not preferable.
焼成時間は造孔剤の添加量や焼成温度に応じて任意の時間行われるが、例えば添加量が非晶質シリカ粉末との体積比で０．１〜０．２、焼成温度が１３５０〜１５００℃の場合、焼成時間は１時間から２０時間で行う。焼成時間が短いと焼結が十分進まず、気孔が開気孔となるため好ましくない。また、焼成時間が長すぎると焼結が進み過ぎ気孔が小さくなるため赤外光の遮光性が低下するとともに、焼成体内に含まれるクリストバライト量が多くなり、クリストバライトの高温型から低温型への相転移に伴う体積収縮によって、焼成体にクラックが発生する恐れがあり好ましくない。 The firing time is arbitrary depending on the amount of the pore-forming agent added and the firing temperature. For example, the addition amount is 0.1 to 0.2 in terms of volume ratio with the amorphous silica powder, and the firing temperature is 1350 to 1500. At ° C., the firing time is 1 to 20 hours. If the firing time is short, sintering does not proceed sufficiently and the pores become open pores, which is not preferable. In addition, if the firing time is too long, sintering proceeds too much and the pores become smaller, so that the light-shielding property of infrared light is lowered and the amount of cristobalite contained in the fired body increases, so that the phase of cristobalite from the high temperature type to the low temperature type is changed. The volume shrinkage accompanying the transition may cause cracks in the fired body, which is not preferable.
造孔剤の消失のための加熱は造孔剤が消失する雰囲気で行われ、例えば造孔剤として黒鉛粉末やアモルファスカーボンを用いる場合は、酸素が存在する雰囲気下で行われる。 The heating for the disappearance of the pore-forming agent is performed in an atmosphere in which the pore-forming agent disappears. For example, when graphite powder or amorphous carbon is used as the pore-forming agent, it is performed in an atmosphere in which oxygen is present.
閉気孔化のための焼成の雰囲気は特に限定されず、大気雰囲気下、窒素雰囲気下、真空雰囲気下で行うことができる。 The firing atmosphere for closing the pores is not particularly limited, and the firing can be performed in an atmospheric atmosphere, a nitrogen atmosphere, or a vacuum atmosphere.
このように本願の不透明石英ガラスの製造方法は、原料粉末を混合して前述の特性を有するようにシリカ凝集体を低減する混合工程と、混合工程で得られた混合粉末を成形する成形工程と、成形工程で得られた成形体を焼結する焼成工程を有することが好ましい。 As described above, the method for producing opaque quartz glass of the present application includes a mixing step of mixing raw material powders to reduce silica aggregates so as to have the above-mentioned characteristics, and a molding step of molding the mixed powder obtained in the mixing step. , It is preferable to have a firing step of sintering the molded product obtained in the molding step.
本発明の不透明石英ガラスは、熱遮断性能に優れることから、熱処理装置用部材、半導体製造装置用部材、ＦＰＤ製造装置用部材、太陽電池製造装置用部材、ＬＥＤ製造装置用部材、ＭＥＭＳ製造装置用部材、光学部材などに利用することができる。具体的には、フランジ、断熱フィン、炉芯管、均熱管、薬液精製筒等の構成材料、シリコン溶融用ルツボ等の構成材料などが挙げられる。 Since the opaque quartz glass of the present invention is excellent in heat blocking performance, it is used for heat treatment equipment members, semiconductor manufacturing equipment members, FPD manufacturing equipment members, solar cell manufacturing equipment members, LED manufacturing equipment members, and MEMS manufacturing equipment members. It can be used for members, optical members, and the like. Specific examples thereof include constituent materials such as flanges, heat insulating fins, core tubes, heat soaking tubes, chemical purification cylinders, and crucibles for melting silicon.
上記のような部材は、不透明石英ガラス単独で使用してもよいし、不透明石英ガラス表面の一部または全体に透明石英ガラス層を付与して使用してもよい。透明石英ガラス層は、不透明石英ガラスをシール性の要求される用途に使用する場合に、不透明石英ガラス中に含まれている気孔がシール面に露出しパッキンを使用しても完全なシールをすることが困難であることを考慮して付与される。また、不透明石英ガラスを各種用途で使用する中で随時行われる洗浄工程において、その最表面に露出している気孔が削られ、不透明石英ガラスの表面の一部が脱落し、パーティクルの発生の原因となる場合がある。これを防止する目的でも透明石英ガラス層は付与される。 The above-mentioned member may be used alone with the opaque quartz glass, or may be used by imparting a transparent quartz glass layer to a part or the whole of the surface of the opaque quartz glass. When the opaque quartz glass is used for applications requiring sealing properties, the transparent quartz glass layer provides complete sealing even if the pores contained in the opaque quartz glass are exposed on the sealing surface and packing is used. Granted in consideration of the difficulty. In addition, in the cleaning process that is performed as needed while using the opaque quartz glass for various purposes, the pores exposed on the outermost surface are scraped off, and a part of the surface of the opaque quartz glass falls off, causing the generation of particles. May be. A transparent quartz glass layer is also provided for the purpose of preventing this.
不透明石英ガラスへの透明石英ガラス層の付与の方法は特に限定されず、不透明ガラスの表面を酸水素炎で溶融して透明石英ガラスとする方法、不透明石英ガラスと透明石英ガラスとを酸水素炎や電気炉で加熱して貼り合わせる手法、不透明石英ガラスとなる非晶質シリカ粉末と造孔剤の混合粉末と透明石英ガラスとなる非晶質シリカ粉末とを所望のガラスにおける透明部及び不透明部の位置に対応させて成形し焼成する方法などがある。 The method of applying the transparent quartz glass layer to the opaque quartz glass is not particularly limited, and a method of melting the surface of the opaque glass with an acid hydrogen flame to obtain a transparent quartz glass, and a method of forming the opaque quartz glass and the transparent quartz glass into a hydrogen acid flame A method of heating and laminating in an electric furnace, a mixed powder of amorphous silica powder to be opaque quartz glass and a pore-forming agent, and amorphous silica powder to be transparent quartz glass in a desired glass. There is a method of molding and firing according to the position of.
本発明の不透明石英ガラスは、光学的に均質であるため遮熱性能のバラツキが少なく、特に半導体製造分野で使用される各種の炉芯管、治具類及びベルジャー等の容器類、例えば、シリコンウェーハ処理用の炉芯管やそのフランジ部、断熱フィン、薬液精製筒及びシリコン溶解用ルツボ等の構成材料として利用できる。 Since the opaque quartz glass of the present invention is optically homogeneous, there is little variation in heat shielding performance, and various furnace core tubes, jigs, and containers such as bell jars used in the semiconductor manufacturing field, for example, silicon. It can be used as a constituent material for a furnace core tube for wafer processing, its flange, heat insulating fins, a chemical purification cylinder, a crucible for silicon dissolution, and the like.
以下に本発明を具体例に従って詳細に説明するが、本発明はこれらに限定されるものではない。なお、シリカ粉末及び不透明石英ガラスの各物性については以下の手順で測定を行った。 The present invention will be described in detail below with reference to specific examples, but the present invention is not limited thereto. The physical characteristics of silica powder and opaque quartz glass were measured according to the following procedure.
（平均粒径）
非晶質シリカ粉末の平均粒径は、レーザー回折式粒度分布測定装置（株式会社島津製作所製、商品名「ＳＡＬＤ−７１００」）を用いて測定されるメディアン径（Ｄ５０）の値を用いた。
(Average particle size)
For the average particle size of the amorphous silica powder, the value of the median diameter (D50) measured using a laser diffraction type particle size distribution measuring device (manufactured by Shimadzu Corporation, trade name “SALD-7100”) was used.
（非晶質シリカ凝集体の個数密度）
混合粉末における非晶質シリカ凝集体の単位面積当たりの個数密度は次の方法で測定した。まず、非晶質シリカ粉末と造孔材の混合粉末を両側から石英ガラス板で挟み、反射型顕微鏡（株式会社キーエンス製、ＤＩＧＩＴＡＬ ＭＩＣＲＯＳＣＯＰＥ ＶＨＸ−９００）で、スケールを入れた画像を撮影した。石英ガラスで挟まれた粉末層の厚みは約１ｍｍであった。次に画像処理ソフト（ＩｍａｇｅＪ １．４６）を使用し、以下の手順で撮影した画像の画像処理を行った。 ＩｍａｇｅＪを立ち上げ、画像処理するファイルを開いた。「Ｉｍａｇｅ」→「Ｔｙｐｅ」→「８−ｂｉｔ」を実行した。続いて「Ｉｍａｇｅ」→「Ａｄｊｕｓｔ」→「Ｔｈｒｅｓｈｏｌｄ」を実行した。
(Number density of amorphous silica aggregates)
The number density of amorphous silica aggregates per unit area in the mixed powder was measured by the following method. First, a mixed powder of amorphous silica powder and pore-forming material was sandwiched between quartz glass plates from both sides, and a scaled image was taken with a reflective microscope (DIGITAL MICROSCOPE VHX-900, manufactured by Keyence Co., Ltd.). The thickness of the powder layer sandwiched between the quartz glasses was about 1 mm. Next, using image processing software (ImageJ 1.46), image processing of the image taken by the following procedure was performed. I launched ImageJ and opened the file for image processing. "Image"->"Type"->"8-bit" was executed. Then, "Image"->"Adjust"->"Throld" was executed.
ヒストグラムのウインドが開くので、各輝度値に対する画素数が最も大きい輝度値を閾値に設定した後、「Ａｐｐｌｙ」を実行して二値化した。画像のスケール部分に重なるように直線を入れた後、「Ａｎａｌｙｚｅ」→「Ｓｅｔ Ｓｃａｌｅ」を実行し、「Ｋｎｏｗｎ ｄｉｓｔａｎｃｅ」にスケールの値を入力し、「Ｕｎｉｔ ｏｆ ｌｅｎｇｔｈ」にスケールの単位を入れ、「ＯＫ」を実行し、ピクセル当たりの長さを設定した。スケールを除去するように、画像の任意の範囲を指定し、「Ｉｍａｇｅ」→「Ｃｒｏｐ」を実行し、画像を切り出した。「Ｐｒｏｃｅｓｓ」→「Ｂｉｎａｒｙ」→「Ｓｋｅｌｅｔｏｎｉｚｅ」を実行し、白黒画像において対象の縁からその骨格が単一の画素になるまで画素を繰り返し除いた。「Ｐｒｏｃｅｓｓ」→「Ｂｉｎａｒｙ」→「Ｄｉｌａｔｅ」を実行し、隣接３×３ピクセルをその最大値（暗値）にそれぞれのピクセルを置き換えた。「Ｄｉｌａｔｅ」は２回行った。「Ｅｄｉｔ」→「Ｉｎｖｅｒｔ」を実行し、白と黒を反転した。「Ａｎａｌｙｚｅ」→「Ａｎａｌｙｚｅ ｐａｒｔｉｃｌｅｓ」を実行した。「Ｓｉｚｅ（ｍｍ＾２）」に０．０４−Ｉｎｆｉｎｉｔｙと入力した。「Ｓｈｏｗ」を「Ｏｕｔｌｉｎｅｓ」に変え、「Ｄｉｓｐｌａｙ ｒｅｓｕｌｔｓ」、「Ｓｕｍｍａｒｉｚｅ」にチェックを入れ、「ＯＫ」を実行した。「Ｃｏｕｎｔ」として０．０４ｃｍ２以上の面積を有する部分（非晶質シリカ凝集体）の個数ｎが表示された。また、「Ｔｏｔａｌ Ａｒｅａ」として０．０４ｃｍ２以上の面積を有する部分の面積の合計値と、「％Ａｒｅａ」として画像全体の面積に対して、０．０４ｃｍ２以上の面積を有する部分の面積の合計値が占める割合が表示されるので、これらの値から画像全体の面積Ｓｃｍ２を求めた。ｎとＳから非晶質シリカ凝集体の単位面積当たりの個数密度を次式で求めた。
非晶質シリカ凝集体の単位面積当たりの個数密度 ＝ ｎ／Ｓ
Since the window of the histogram opens, the luminance value having the largest number of pixels for each luminance value is set as the threshold value, and then "Apply" is executed to binarize the luminance value. After inserting a straight line so that it overlaps the scale part of the image, execute "Analyze" → "Set Scale", enter the scale value in "Know distance", enter the scale unit in "Unit of length", and enter the scale unit. "OK" was executed and the length per pixel was set. An arbitrary range of the image was specified so as to remove the scale, and "Image"->"Crop" was executed to crop the image. “Process” → “Binary” → “SKeletonize” was executed, and pixels were repeatedly removed from the edge of the target in a black-and-white image until the skeleton became a single pixel. "Process"->"Binary"->"Dilate" was executed, and each pixel was replaced with the maximum value (dark value) of the adjacent 3 × 3 pixels. "Dilate" was performed twice. "Edit"->"Invert" was executed, and white and black were reversed. "Analysis"->"Analysisparticles" was executed. 0.04-Infinity was entered in "Size (mm ^ 2)". "Show" was changed to "Outlines", "Display results" and "Summerize" were checked, and "OK" was executed. As "Count", the number n of the portions (amorphous silica aggregates) having an area of 0.04 cm 2 or more was displayed. Further, as "Total Area" and the total value of the area of the portion having a 0.04 cm 2 or more areas, with respect to the entire image area as "% Area", the area of the portion having a 0.04 cm 2 or more areas Since the ratio occupied by the total value is displayed, the area Scm 2 of the entire image was obtained from these values. The number density of amorphous silica aggregates per unit area was calculated from n and S by the following equation.
Number density per unit area of amorphous silica aggregate = n / S
（白抜けの個数密度）
不透明石英ガラスの白抜けの単位面積当たりの個数密度は、次の方法で測定した。不透明石英ガラスをダイヤモンドブレードで切断し、縦２０ｍｍ、横２０ｍｍ、厚さを３ｍｍとして試料を作製し、試料の裏面より透過光を当て、実体顕微鏡（株式会社ニコン製ＳＭＺ７４５Ｔ）で、スケールを入れた画像を撮影した。次に画像処理ソフト（ＩｍａｇｅＪ １．４６）を使用し、以下の手順で撮影した画像処理を行った。 ＩｍａｇｅＪを立ち上げ、画像処理するファイルを開いた。画像のスケール部分に重なるように直線を入れた後、「Ａｎａｌｙｚｅ」→「Ｓｅｔ Ｓｃａｌｅ」を実行し、「Ｋｎｏｗｎ ｄｉｓｔａｎｃｅ」にスケールの値を入力し、「Ｕｎｉｔ ｏｆ ｌｅｎｇｔｈ」にスケールの単位を入れ、「ＯＫ」を実行し、ピクセル当たりの長さを設定した。スケールを除去するように、四角形で画像の任意の範囲を指定し、「Ｉｍａｇｅ」→「Ｃｒｏｐ」を実行し、画像を切り出した。「Ｉｍａｇｅ」→「Ｔｙｐｅ」→「８−ｂｉｔ」を実行した。「Ｉｍａｇｅ」→「Ａｄｊｕｓｔ」→「Ｔｈｒｅｓｈｏｌｄ」を実行した。ヒストグラムのウインドが開くので、透過している部分とそれ以外に分かれるように閾値を設定し二値化した。なお、閾値については、各輝度値に対する画素数が最も大きい輝度値をａ、輝度値の最小値をｂとして、２ａ−ｂを閾値として採用した。「Ｅｄｉｔ」→「Ｉｎｖｅｒｔ」を実行した。
(Number density of white spots)
The number density per unit area of the white spots of the opaque quartz glass was measured by the following method. Opaque quartz glass was cut with a diamond blade to prepare a sample with a length of 20 mm, a width of 20 mm, and a thickness of 3 mm, transmitted light was applied from the back surface of the sample, and a scale was placed with a stereomicroscope (SMZ745T manufactured by Nikon Corporation). I took an image. Next, using image processing software (ImageJ 1.46), image processing taken by the following procedure was performed. I launched ImageJ and opened the file for image processing. After inserting a straight line so that it overlaps the scale part of the image, execute "Analyze" → "Set Scale", enter the scale value in "Know distance", enter the scale unit in "Unit of length", and enter the scale unit. "OK" was executed and the length per pixel was set. An arbitrary range of the image was specified by a rectangle so as to remove the scale, and "Image"->"Crop" was executed to crop the image. "Image"->"Type"->"8-bit" was executed. "Image"->"Adjust"->"Throld" was executed. Since the window of the histogram opens, we set the threshold value so that it can be divided into the transparent part and the other part, and binarized it. Regarding the threshold value, the brightness value having the largest number of pixels for each brightness value was adopted as a, the minimum value of the brightness value was set as b, and 2ab was adopted as the threshold value. "Edit"->"Invert" was executed.
「Ａｎａｌｙｚｅ」→「Ａｎａｌｙｚｅ ｐａｒｔｉｃｌｅｓ」を実行した。「Ｓｉｚｅ（ｍｍ＾２）」に０．０４−Ｉｎｆｉｎｉｔｙと入力した。「Ｓｈｏｗ」を「Ｏｕｔｌｉｎｅｓ」に変え、「Ｄｉｓｐｌａｙ ｒｅｓｕｌｔｓ」、「Ｓｕｍｍａｒｉｚｅ」にチェックを入れ、「ＯＫ」を実行した。「Ｃｏｕｎｔ」として０．０４ｃｍ２以上の面積を有する部分（白抜け）の個数ｍが表示された。また、「Ｔｏｔａｌ Ａｒｅａ」として０．０４ｃｍ２以上の面積を有する部分の面積の合計値と、「％Ａｒｅａ」として画像全体の面積に対して、０．０４ｃｍ２以上の面積を有する部分の面積の合計値が占める割合が表示されるので、これらの値から画像全体の面積Ｒｃｍ２を求めた。ｍとＲから白抜けの単位面積当たりの個数密度を次式で求めた。
白抜けの単位面積当たりの個数密度 ＝ ｍ／Ｒ
"Analysis"->"Analysisparticles" was executed. 0.04-Infinity was entered in "Size (mm ^ 2)". "Show" was changed to "Outlines", "Display results" and "Summerize" were checked, and "OK" was executed. As "Count", the number m of the portion (white spot) having an area of 0.04 cm 2 or more was displayed. Further, the total value of the area of the portion having an area of 0.04 cm 2 or more as "Total Area" and the area of the portion having an area of 0.04 cm 2 or more with respect to the area of the entire image as "% Area". Since the ratio occupied by the total value is displayed, the area Rcm 2 of the entire image was obtained from these values. From m and R, the number density per unit area of white spots was calculated by the following equation.
Number density per unit area of white spots = m / R
（赤外線透過率）
不透明石英ガラスの赤外スペクトルはＦＴＩＲ装置（（株）島津製作所製、商品名「ＩＲＰｒｅｓｔｉｇｅ−２１」）を用いて測定した。測定試料は、平面研削により加工し、厚さ１ｍｍとした。
(Infrared transmittance)
The infrared spectrum of the opaque quartz glass was measured using an FTIR apparatus (manufactured by Shimadzu Corporation, trade name "IRPrestig-21"). The measurement sample was processed by surface grinding to a thickness of 1 mm.
実施例１
シリカ原料粉末として、化学的純度が９９．９ｗｔ％以上である非晶質シリカ粉末（日本化成株式会社製、商品名「ＭＫＣシリカＰＳ１００」）を平均粒径（メディアン径Ｄ５０）が４μｍとなるまでジェットミルで粉砕したものを使用した。造孔材粉末として、平均粒径１８μｍの球状黒鉛粉末（日本カーボン株式会社製、商品名「ニカビーズ」）を使用した。
Example 1
Amorphous silica powder (manufactured by Nihon Kasei Co., Ltd., trade name "MKC silica PS100") having a chemical purity of 99.9 wt% or more as a silica raw material powder until the average particle size (median diameter D50) becomes 4 μm. The one crushed by a jet mill was used. As the pore-forming material powder, spheroidal graphite powder having an average particle diameter of 18 μm (manufactured by Nippon Carbon Co., Ltd., trade name “Nika beads”) was used.
非晶質シリカ粉末と黒鉛粉末をその体積比が０．１になるように袋に入れ、３分間シェイクした後、目開き１８４μｍのふるいを１回通して混合粉末とした。観察倍率×５０で混合粉末を観察し、画像処理において、映り込んだスケール部分を除く９０％以上の範囲を指定し、画像処理を行った。図３、４、５、６に実施例１の混合粉末の画像処理の過程における画像を、図１１、１２、１３に実施例１の不透明石英ガラスの画像処理の過程における画像を示す。 Amorphous silica powder and graphite powder were placed in a bag so that the volume ratio was 0.1, shaken for 3 minutes, and then passed through a sieve having an opening of 184 μm once to prepare a mixed powder. The mixed powder was observed at an observation magnification of 50, and in the image processing, an image processing was performed by designating a range of 90% or more excluding the reflected scale portion. FIGS. 3, 4, 5 and 6 show images in the process of image processing of the mixed powder of Example 1, and FIGS. 11, 12 and 13 show images in the process of image processing of the opaque quartz glass of Example 1.
混合粉末を発泡スチロール製の型に充填し、発泡スチロール型全体をポリスチレン製袋で減圧封入し、圧力は２８０ＭＰａ、保持時間は１分間の条件で冷間等方圧プレス（ＣＩＰ）成形した。 The mixed powder was filled in a styrofoam mold, and the entire styrofoam mold was sealed under reduced pressure in a polystyrene bag, and cold isotropic press (CIP) molding was performed under the conditions of a pressure of 280 MPa and a holding time of 1 minute.
ＣＩＰ成形後の直径１７３ｍｍ、厚み４４ｍｍの円柱状成形体を、炉床昇降式抵抗加熱電気炉（（株）広築製、型式「ＨＰＦ−７０２０」）にて、大気雰囲気下で、室温から６５０℃までは１００℃／時、６５０℃から８００℃まで５０℃／時、８００℃で３６時間保持、８００℃から最高焼成温度１４２５℃までは５０℃／時で昇温し、最高焼成温度１４２５℃で４時間保持して焼成した。１００℃／時で５０℃まで降温し、その後炉冷し不透明石英ガラスを得た。使用した混合粉末のシリカ凝集体の個数密度、不透明石英ガラスの白抜けの個数密度をそれぞれ表１に示す。 A columnar molded body with a diameter of 173 mm and a thickness of 44 mm after CIP molding is placed in a hearth elevating resistance heating electric furnace (manufactured by Hiroki Co., Ltd., model "HPF-7020") in an air atmosphere from room temperature to 650. Hold at 100 ° C./hour up to 100 ° C./hour, 50 ° C./hour from 650 ° C. to 800 ° C., hold at 800 ° C. for 36 hours, raise the temperature from 800 ° C. to the maximum firing temperature 1425 ° C. at 50 ° C./hour, and maximum firing temperature 1425 ° C. It was held for 4 hours and fired. The temperature was lowered to 50 ° C. at 100 ° C./hour, and then the temperature was cooled in a furnace to obtain opaque quartz glass. Table 1 shows the number densities of silica aggregates in the mixed powder used and the number densities of white spots in opaque quartz glass.
実施例２
ふるいを通す回数を２回にした以外は実施例１と同様の方法で混合粉末を得た。得られた混合粉末を用いて、実施例１と同様の方法で成形体を作製し、実施例１と同様の条件で前記成形体を焼成して、不透明石英ガラスを得た。使用した混合粉末のシリカ凝集体の個数密度、不透明石英ガラスの白抜けの個数密度をそれぞれ表１に示す。
Example 2
A mixed powder was obtained in the same manner as in Example 1 except that the number of times of sieving was set to 2. Using the obtained mixed powder, a molded product was produced in the same manner as in Example 1, and the molded product was fired under the same conditions as in Example 1 to obtain opaque quartz glass. Table 1 shows the number densities of silica aggregates in the mixed powder used and the number densities of white spots in opaque quartz glass.
実施例３
ふるいを通す回数を３回にした以外は実施例１と同様の方法で混合粉末を得た。得られた混合粉末を用いて、実施例１と同様の方法で成形体を作製し、実施例１と同様の条件で前記成形体を焼成して、不透明石英ガラスを得た。使用した混合粉末のシリカ凝集体の個数密度、不透明石英ガラスの白抜けの個数密度をそれぞれ表１に示す。
実施例４
粉末混合をポットミルで３時間混合する方法に変えた以外は実施例１と同様の方法で混合粉末を得た。得られた混合粉末を用いて、実施例１と同様の方法で成形体を作製し、実施例１と同様の条件で前記成形体を焼成して、不透明石英ガラスを得た。使用した混合粉末のシリカ凝集体の個数密度は０個／ｃｍ２、得られた不透明石英ガラスの白抜けの個数密度は０個／ｃｍ２であった。得られた不透明石英ガラスの試料厚さ１ｍｍのときの波長１．５μｍから５μｍにおける直線透過率は１％以下であり、波長２μｍにおける透過率は０．８２％、波長４μｍにおける透過率は０．４６％であった。
Example 3
A mixed powder was obtained in the same manner as in Example 1 except that the number of times of sieving was set to 3. Using the obtained mixed powder, a molded product was produced in the same manner as in Example 1, and the molded product was fired under the same conditions as in Example 1 to obtain opaque quartz glass. Table 1 shows the number densities of silica aggregates in the mixed powder used and the number densities of white spots in opaque quartz glass.
Example 4
A mixed powder was obtained in the same manner as in Example 1 except that the powder mixing was changed to a method of mixing in a pot mill for 3 hours. Using the obtained mixed powder, a molded product was produced in the same manner as in Example 1, and the molded product was fired under the same conditions as in Example 1 to obtain opaque quartz glass. The number density of silica aggregates in the mixed powder used was 0 pieces / cm 2 , and the number density of white spots in the obtained opaque quartz glass was 0 pieces / cm 2 . When the sample thickness of the obtained opaque quartz glass is 1 mm, the linear transmittance at a wavelength of 1.5 μm to 5 μm is 1% or less, the transmittance at a wavelength of 2 μm is 0.82%, and the transmittance at a wavelength of 4 μm is 0. It was 46%.
比較例１
ふるいを通す回数を０回にした以外は実施例１と同様の方法で混合粉末を得た。得られた混合粉末を用いて、実施例１と同様の方法で成形体を作製し、実施例１と同様の条件で前記成形体を焼成して、不透明石英ガラスを得た。使用した混合粉末のシリカ凝集体の個数密度、不透明石英ガラスの白抜けの個数密度をそれぞれ表１に示す。
Comparative Example 1
A mixed powder was obtained in the same manner as in Example 1 except that the number of times of sieving was set to 0. Using the obtained mixed powder, a molded product was produced in the same manner as in Example 1, and the molded product was fired under the same conditions as in Example 1 to obtain opaque quartz glass. Table 1 shows the number densities of silica aggregates in the mixed powder used and the number densities of white spots in opaque quartz glass.
図７、８、９、１０に比較例１の混合粉末の画像処理の過程における画像を、図１４、１５、１６に比較例１の不透明石英ガラスの画像処理の過程における画像を示す。 7, 8, 9 and 10 show images in the process of image processing of the mixed powder of Comparative Example 1, and FIGS. 14, 15 and 16 show images in the process of image processing of the opaque quartz glass of Comparative Example 1.
熱遮断効果が高い不透明石英ガラスであり、半導体製造装置用部材などに好適に用いることができる。 It is an opaque quartz glass having a high heat blocking effect, and can be suitably used for a member for a semiconductor manufacturing apparatus or the like.
Claims (3)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015159201 | 2015-08-11 | ||
| JP2015159201 | 2015-08-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017036203A JP2017036203A (en) | 2017-02-16 |
| JP6885002B2 true JP6885002B2 (en) | 2021-06-09 |
Family
ID=58047231
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016155361A Active JP6885002B2 (en) | 2015-08-11 | 2016-08-08 | Opaque quartz glass |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6885002B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014088286A (en) * | 2012-10-30 | 2014-05-15 | Tosoh Corp | Opaque quartz glass and production method thereof |
| JP2014091634A (en) * | 2012-10-31 | 2014-05-19 | Tosoh Corp | Opaque quartz glass and method for manufacturing the same |
| TWI652240B (en) * | 2014-02-17 | 2019-03-01 | 日商東曹股份有限公司 | Opaque quartz glass and method of manufacturing same |
-
2016
- 2016-08-08 JP JP2016155361A patent/JP6885002B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2017036203A (en) | 2017-02-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10005693B2 (en) | Opaque quartz glass and method for its production | |
| Ratzker et al. | Optical and mechanical properties of transparent alumina fabricated by high-pressure spark plasma sintering | |
| Kim et al. | Effects of preheating of powder before spark plasma sintering of transparent MgAl2O4 spinel | |
| JPWO2008069194A1 (en) | Synthetic opaque quartz glass and method for producing the same | |
| Boulesteix et al. | Highly transparent Nd: Lu2O3 ceramics obtained by coupling slip-casting and spark plasma sintering | |
| TWI705045B (en) | Method for producing a pore-containing opaque quartz glass | |
| JP2014091634A (en) | Opaque quartz glass and method for manufacturing the same | |
| JP6379508B2 (en) | Opaque quartz glass and method for producing the same | |
| Singarapu et al. | Glass-ceramics processed by spark plasma sintering (SPS) for optical applications | |
| Nečina et al. | Magnesium fluoride (MgF2)–A novel sintering additive for the preparation of transparent YAG ceramics via SPS | |
| Lee et al. | Fabrication of transparent Y2O3 ceramics by two‐step spark plasma sintering | |
| JP6885002B2 (en) | Opaque quartz glass | |
| JP2019199078A (en) | Method for manufacturing ceramic molding for sintering and method for manufacturing ceramic sintered body | |
| US10889524B2 (en) | Methods of producing ceramic molded product and transparent sintered body | |
| EP3950637A1 (en) | Aluminum sintered body production method and aluminum sintered body | |
| US7045091B1 (en) | Transient liquid phase reactive sintering of aluminum oxynitride (AlON) | |
| JP2017154945A (en) | Opaque quartz glass | |
| Han et al. | Large‐sized La2O3‐TiO2 high refractive glasses with low SiO2 fraction by hot‐press sintering | |
| JP6273997B2 (en) | Opaque quartz glass and method for producing the same | |
| CN108238717A (en) | For producing the method for opaque silica glass and the blank as made from opaque silica glass | |
| WO2017110799A1 (en) | Glass having fine bubbles and method for manufacturing same | |
| JP2011037642A (en) | Translucent spinel ceramics and method for producing the same | |
| Qadri et al. | Spinel optics for high energy lasers | |
| JP2015166292A (en) | Opaque quartz glass and method for producing the same | |
| Zhou | ZnSe ceramics and phosphate glasses for optical applications in the visible and infrared ranges |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20190712 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20200713 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200818 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20201007 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20210105 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20210308 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20210413 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20210426 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 6885002 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |