Shin-Etsu Chemical Co., Ltd.

Hideki Fujii

Shinichi Sato

Noriyuki Koike

Hirofumi Kishita

Hitoshi Kinami

Kouichi Yamaguchi

Shuji Suganuma

Toshio Takago

Shinichi Satoh

Yoshikazu Saito

Akio Takaoka

Takashi Matsuda

Kenichi Fukuda

Yasushi Yamamoto

Tadakatsu Shimada

Hideo Hirasawa

Waichi Yamamura

Takaaki Nagao

Masayuki Oyama

Nobuyuki Kobayashi

Shoji Hoshino

Takashi Koshigai

An optical fiber base material machining method for forming spindle-shaped portions at ends of the optical fiber base material by severing the optical fiber base material after reducing an outer diameter of the optical fiber base material to a predetermined target outer diameter at a predetermined machining position, comprising: reducing the outer diameter to a predetermined intermediate outer diameter between the outer diameter before the machining and the target outer diameter at the machining position; flame polishing a surface of the optical fiber base material in a region including the machining position; and further reducing the outer diameter of the optical fiber base material.

Optical fiber base material machining method

Provided is a method of processing a glass base material for optical fiber in which the glass base material for optical fiber is elongated to reduce a diameter thereof until reaching a final elongation diameter and form a completed base material. The method includes measuring an outer diameter distribution that includes an outer diameter of the glass base material for optical fiber; setting an effective region; calculating a target elongation diameter that is larger than the final elongation diameter and less than an average diameter of the effective region, and elongating the glass base material for optical fiber until reaching the target elongation diameter; and after reaching the target elongation diameter, further elongating the glass base material for optical fiber until reaching the final elongation diameter.

Processing method of glass base material for optical fiber

A glass base material elongating method of elongating a glass base material to make a diameter of the glass base material smaller by connecting a pulling dummy at an end of the glass base material and then gripping and pulling the pulling dummy with a pair of rollers that grip or release the pulling dummy is provided. The method includes forming a rough surface part on the pulling dummy before elongating the glass base material. The rough surface part may be formed by grinding the pulling dummy. Also, the rough surface part of the pulling dummy may have a roughness of 5 &#x3bc;m or more.

Glass base material elongating method

To manufacture glass base material with high manufacturing yield, provided is a glass base material elongating method comprising forming a tapered portion where the outer diameter of the glass base material changes continuously, holding the glass base material with chucks, heating the glass base material held by chucks with a heat source, and with a portion of the glass base material softened, increasing the distance between the chucks to elongate the glass base material. The elongation begins from a state in which a position of the heat source at a position at which the outer diameter of the glass base material is set in a range from no less than 95% to no more than 98% of an average outer diameter of the trunk portion of the glass base material.

The invention provides an electrostatic chuck in which a workpiece-chucking surface is made flat. An electrostatic chuck with a built-in electric heating means comprises a base plate formed of carbon or a carbon-based composite material and, successively formed on one surface of the base plate, an insulating layer (a), an electroconductive layer (a) to serve as a chucking electrode and an dielectric layer (a) to form a workpiece-chucking surface and, successively formed on the other surface of the base plate, an insulating layer (b) and an electroconductive layer (b) to serve as an electric heater element, the electrostatic chuck improved in that the workpiece-chucking surface of the electrostatic chuck and an opposite surface thereof are warped to have a relationship selected from concavo-convex and convexo-concave, and in that the warping of the surfaces is in a manner such that the workpiece-chucking surface of the dielectric layer is rendered flat when the opposite surface of the electrostatic chuck is fastened to a machine.

Electrostatic chuck and manufacturing method thereof

A ceramic heater for heating a semiconductor wafer under processing and has a layered structure wherein on one surface of a supporting substrate made of carbon or a carbon-based composite material, successively formed layers including an insulating layer, and electroconductive layer as an electric heating element and a dielectric layer. A first step for partly or completely removing the layer or layers having degraded properties by means of a suitable method such as sandblasting and a second step of re-forming the layer or layers having been removed in the first step. The invention allows for a substantial cost decrease as compared with the conventional way by replacing the worn-out ceramic heater with a newly manufactured one.

Method for restoring ceramic heater

The optical fiber base material heat treatment method can be provided that the first flame polishing heats the surface of the optical fiber base material ( ) with fixing a length of the optical fiber base material ( ) and the second flame polishing heats the surface of the optical fiber base material ( ) by lower temperature than the temperature of the heating of the first flame polishing.

Double flame polishing method for fiber preforms

There is provided a process for preparing a hydrogensiloxane of the following general formula (2): ##STR1## wherein Rf is a perfluoropolyether or perfluoroalkylene group, n is equal to 1, 2 or 3, and p is equal to 0 or 1, said process comprising the step of hydrolyzing a chlorosilane of the following general formula (1): ##STR2## wherein Rf, n and p are as defined above, along with 1,1,3,3-tetramethyldisiloxane.

Preparation of hydrogensiloxanes

A fluorine-containing organosilicon compound according to the present invention is expressed by the general formula: ##STR1## wherein Rf is a perfluoropolyether group having 3 to 17 carbon atoms, R is an alkylene group having 1 to 6 carbon atoms or an ether group expressed by the general formula:

Fluorine-containing organosilicon compound

Fluorinated organic silicon compound of the general formula: ##STR1## wherein R is an alkyl group having 1 to 6 carbon atoms, n is an integer of from 1 to 6, and m is equal to 1, 2 or 3 are novel and useful as treating agents and intermediates for the synthesis of fluorinated cyclic organic silicon compounds. The fluorinated organic silicon compounds are prepared by reacting a chlorosilane with a fluorinated olefin.

Fluorinated organic silicon compounds and method for making

Fluorine-containing organosilicon compound according to the present invention is expressed by the general formula: ##STR1## wherein Rf is a perfluoropolyether group having 3 to 17 carbon atoms, R is an alkylene group having 1 to 6 carbon atoms or a group of the general formula, --R.sup.2 --O--R.sup.3 --, wherein R.sup.2 and R.sup.3 may be the same or different and are each alkylene groups having 1 to 6 carbon atoms. The present compound is useful as a curing catalyst for organo-polysiloxane compounds that are condensation curable at room temperature. The compositions added with the fluorine-containing organosilicon compound have excellent characteristics such as water and oil repellencies, chemical resistance and contamination resistance and offer a variety of uses such as high performance sealing, coating and electric insulating materials.

A process for purifying an ethylene compound having a fluorine-containing organic group (fluorine-containing ethylene compound) by mixing the fluorine-containing ethylene compound with an alkali metal or alkaline earth metal reducing agent, and subjecting the resulting mixture to irradiation with ultraviolet radiation, followed by washing with water. The purification process ensures effective removal of iodides which are sources of molecular iodine, from the fluorine-containing ethylene compound.

Process for purification of ethylene compound having fluorine-containing

Organic silicon compounds of formula (1) are novel: ##STR1## In the formula, R.sup.1, R.sup.2 and R.sup.3 are monovalent C.sub.1-8 hydrocarbon group, R.sup.4 is a C.sub.1-6 alkyl group, R.sup.5 is a C.sub.2-6 alkylene group or a C.sub.2-6 alkylene group containing at least one --C--O--C-- linkage, Rf is a C.sub.1-12 perfluoroalkylene or perfluorocyclo-alkylene group or a C.sub.1-12 perfluoroalkylene or perfluorocycloalkylene group containing at least one --C--O--C-- linkage, and n is 1, 2 or 3. The organic silicon compounds are useful source materials for the manufacture of fluorinated polysiloxanes having solvent resistance, chemical resistance and release property.

Organic silicon compounds and method for making

Novel fluorinated carboxylic acid derivatives of the general formula: ##STR1## wherein Rf is a divalent perfluoroalkyl or perfluoropolyether group and Z is halogen, hydroxyl or triorganosiloxy are useful intermediate for the synthesis of various fluorinated compounds. Compounds [I-i] wherein Z in formula [I] is F are prepared by reacting acid fluoride-terminated compounds of the formula: ##STR2## with an alkali fluoride and further with an allyl halide. Compounds [I-ii] wherein Z in formula [I] is a halogen are preparred by reacting compounds [I-i] with lithium halide. Compounds [I-iii] wherein Z in formula [I] is OH are prepared through hydrolysis of compounds [I-ii]. Compounds [I-iv] wherein Z in formula [I] is triorganosiloxy are prepared by reacting compounds [I-iii] with a triorganosilylating agent.

Fluorinated carboxylic acid derivatives and methods for making

Organic silicon compounds of formula (1) are novel. ##STR1## In the formula, wherein R.sup.1 and R.sup.2 are monovalent C.sub.1-8 hydrocarbon group, R.sup.3 is a C.sub.2-6 alkylene group or a C.sub.2-6 alkylene group containing at least one --C--O--C-- linkage, R.sup.4 is a C.sub.1-6 alkyl group, Rf is a C.sub.1-15 perfluoroalkyl or perfluorocycloalkyl group or a C.sub.1-20 perfluoroalkyl or perfluorocycloalkyl group containing at least one --C--O--C-- linkage, and n=0, 1 or 2, m=1 or 2, and k=2, 3 or 4. The organic silicon compounds are useful source materials for the manufacture of fluorinated polysiloxanes having solvent resistance, chemical resistance and release property.

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Annaka, Japan

Hideki Fujii