Shin-etsu Chemical Co., Ltd.

Yoshiyuki Shiono

Toshihiko Ryuo

Masayuki Tanno

Akihiro Endo

Hisaharu Yamaguchi

Takao Uno

Masahiro Yoda

Toshiaki Watanabe

Takeshi Nakajima

Shohei Kozakai

Yoshinori Kuwabara

Satoru Fukuda

Provided is a waterproof sheet such that an adhesive layer is formed on a substrate rubber layer and characterized by the substrate rubber layer comprising a silicone rubber having a JIS-A hardness of 15-90, a tensile strength of at least 3 MPa, an elongation of 100-800%, and a crescent tear strength of at least 3 kN/m. The waterproof sheet can be used without a long-term decrease in material properties, and is waterproof in the long-term. In particular, the present invention can be a waterproof sheet able to withstand long-term use by means of stipulating the material properties of the substrate rubber. By means of a method for applying waterproofing to an outdoor tank, it is possible to reliably waterproof the bottom side of the outdoor tank by means of a simple application method.

Waterproof sheet for outdoor tank and method for applying same

When a bridge pier is reinforced or repaired by wrapping a reinforcement around the pier, a waterproof sheet having a sufficient flexibility to attach to and cover the interface between the pier and the reinforcement in a liquid-tight manner is useful. The waterproof sheet is attached to the interface between the pier and the reinforcement to prevent water from penetrating into the interface for thereby preventing the reinforcement from deterioration.

Waterproof sheet for use in bridge pier repair and waterproof working method using the same

The present invention relates to a waterproofing method for an outdoor tank, the waterproofing method being characterized in that the boundary portion between the bottom of the outdoor tank installed on a foundation and the foundation is covered in a liquid tight manner by a waterproof sheet adhered so as to extend from the outdoor tank to the foundation. The present invention can provide a waterproofing method which is effective to prevent the entry of rain water into the boundary portions between the bottoms of outdoor tanks and the foundations, most of the outdoor tanks being large tanks mainly installed in oil refineries or the like. This waterproofing method for an outdoor tank can more reliably waterproof the bottom side of the outdoor tank using the simple method.

Waterproofing method for outdoor tank

A method of producing a lithium-tantalate crystal comprising, at least subjecting a single-polarized lithium-tantalate crystal wherein an optical absorption coefficient at a wave number of 3480 cmis 0.3 cmor less to a heat treatment under a reducing atmosphere at a temperature of not lower than 250&#xb0; C. and not higher than Curie temperature and a single-polarized lithium-tantalate crystal wherein an optical absorption coefficient at a wave number of 3480 cmis 0.3 cmor less and an electric conductivity is 1&#xd7;10&#x3a9;&#xb7;cmor more. There can be provided a method of producing a single-polarized lithium-tantalate crystal in a short time efficiently wherein the surface charge generated due to a pyroelectric property can be decayed quickly by improving the electric conductivity and a single-polarized lithium-tantalate crystal.

Method of producing single-polarized lithium tantalate crystal and single-polarized lithium tantalate crystal

A method of producing a lithium-tantalate crystal, wherein at least a first material containing lithium tantalate, lithium niobate or hydrogen storage alloy storing hydrogen that is subjected to a heat treatment at a temperature of T1' that is Curie temperature or higher in a reducing atmosphere is superposed on a single-polarized lithium-tantalate crystal, and then the crystal is subjected to a heat treatment at a temperature of T2&#x2032; that is lower than Curie temperature in a reducing atmosphere, thereby an electric conductivity of the single-polarized lithium-tantalate crystal is increased. There can be provided a method of producing a lithium-tantalate crystal wherein the surface charge generated by applying a temperature change to the lithium-tantalate crystal can be decayed quickly without accumulating by increasing the electric conductivity, and an effective piezoelectric property is exhibited by maintaining the single polarized structure.

Method of producing lithium tantalate crystal

An etalon has at least one transparent plate, wherein the transparent plate consists of lithium tantalate single crystal, an etalon has at least one transparent plate, wherein the transparent plate consists of lithium niobate single crystal and a method for producing an etalon, which includes at least growing a single crystal of lithium tantalate or lithium niobate by the Czochralski method, producing a transparent plate from the single crystal and producing an etalon from the transparent plate. There are provided etalons of thin type showing high thermal stability.

Etalon and method for producing etalon

There is disclosed a piezoelectric single crystal wafer wherein an etching pit density on the front surface of the wafer on which an electrode for transmit-receive of surface acoustic wave or leaky surface acoustic wave is formed is 7.8&times;10 /mm or less, and a piezoelectric single crystal wafer wherein surface roughness Ra on the peripheral surface other than the front surface and the reverse surface of the wafer is 2.3 &mgr;m or less. There can be provided a piezoelectric single crystal wafer wherein a deviation of surface acoustic wave velocity or leaky surface acoustic wave velocity is small, namely the uniformity of the velocity is excellent, and fine contaminations adhered on the surface where electrode is formed and breakage of the wafer can be significantly reduced, and therefore a device such as a filter having excellent property can be produced in high yield.

Piezoelectric single crystal wafer

A piezoelectric single crystal wafer for SAW or LSAW devices has an x-ray rocking curve half width of up to 0.06&deg; on the wafer surface on which electrodes are to be formed for transmitting and receiving SAW or LSAW.

SAW or LSAW device piezoelectric single crystal wafer and method of making

An improvement is proposed relating to an optical isolator for bonding of the polarizer and analyzer of polarizing glass to the respective holder rings for position adjustment. The improvement comprises: (a) forming a metallized layer of a specific composition over at least two of the side surfaces of each of the polarizer and analyzer on the area of the surface excepting for the linear areas of 50 to 150 .mu.m width from the top and bottom surfaces of the polarizer or analyzer; and (b) bonding the polarizer and analyzer to the respective holder rings by soldering using a solder alloy with intervention of the metallized layer between the polarizer or analyzer and the holder ring. The invention further provides an optical part having, on at least one of the surfaces, a heat-resistant anti-reflection coating film which is a double-layered film consisting of a thin film of the titanium oxide TiO.sub.x (x=1.9 to 2.2) as the underlayer of high refractive index and a thin film of silicon dioxide as the overlayer of low refractive index.

Optical isolator and optical part having heat-resistant anti-reflection

Proposed is an improvement in a magnetostatic surface wave device such as an S/N enhancer comprising a thin film chip of a magnetic oxide garnet, e.g., gallium-substituted YIG epitaxially grown on the surface of a substrate, e.g., GGG, to which a magnetic field is applied within the plane of the thin film. The low-pass cut-off frequency of the microwaves can be decreased to 400 MHz or lower and the half-value width of magnetic resonance .DELTA.H can be small enough when the principal plane of the thin film of the magnetic oxide garnet is the (110) plane and the magnetic field applied thereto is in such a direction that the angle between the direction of the magnetic field and the direction of the &lt;100&gt; axis of the thin film within the (110) plane is in the range from .+-.27.degree. to .+-.33.degree..

Thin film chip of magnetic oxide garnet and magnetostatic surface wave

Proposed is an improved optical waveguide consisting of a substrate plate such as a silicon wafer, an undercladding layer of silica glass thereon, a core line of silica glass extending on the undercladding layer and having a larger refractive index than the undercladding layer and an overcladding layer of silica glass having a smaller refractive index than the core line to cover the undercladding layer and the core line thereon altogether. Different from conventional optical waveguides of this type, of which each of the undercladding layer, core line and overcladding layer is formed by the flame deposition method of silica or electron-beam vapor deposition method followed by vitrification taking a relatively long time, the overcladding layer in the inventive optical waveguide is formed by forming a layer of an organopolysiloxane resin on the undercladding layer and core line followed by the oxidative thermal decomposition of the resin into silica and vitrification of the same. Alternatively, an optical waveguide, which is conventional as mentioned above but of which the thickness of the overcladding layer is greatly decreased, is provided with a top coating layer from the organopolysiloxane resin as above. The inventive optical waveguides can be manufactured with greatly increased productivity.

Growing community of inventors

Annaka, Japan

Yoshiyuki Shiono