Abstract: The invention relates to a method for producing 1,1,2,2,3,3,4-heptafluorocyclopentane. This method includes the step of reducing 1,1-dichlorooctafluorocyclopentane by hydrogen in the presence of a hydrogenation catalyst. This catalyst contains at least one first metal selected from metals of 8, 9, and 10 groups of periodic table, such as iron, cobalt, palladium, platinum, rhodium, ruthenium, iridium, and osmium. According to this method, it is possible to produce 1,1,2,2,3,3,4-heptafluorocyclopentane with high yield and high selectivity.

Abstract: Disclosed herein are an aromatic vinyl-conjugated diene block copolymer composed of a bound aromatic vinyl unit and a bound conjugated diene unit and containing at least a block aromatic vinyl segment, wherein:(1) a content of the bound aromatic vinyl unit in the block copolymer is 3 to 60 wt. %;(2) a proportion of block aromatic vinyl segment portions having a molecular weight at most a third of a molecular weight (A-Mp) corresponding to a peak in a molecular weight distribution curve of the block aromatic vinyl segment (A) as determined by gel permeation chromatography (GPC) is 55 to 90 mol % based on the total content of the block aromatic vinyl segment (A); and(3) a molecular weight (Mp) corresponding to a peak in a molecular weight distribution curve of the block copolymer as determined by GPC is 10,000 to 1,000,000, a production process thereof, a resin composition comprising the aromatic vinyl-conjugated diene block copolymer, and a preparation process of the resin composition.

Abstract: The invention relates to a photosensitive polyimide resin composition comprising (A) a polyamic acid having, in its main chain, repeating units formed from a polycondensation product of at least one tetracarboxylic acid or tetracarboxylic anhydride thereof with at least one diamine compound, and having actinic ray-sensitive functional groups at both terminals thereof; (B) a photosensitive auxiliary having a photopolymerizable functional group; (C) a photopolymerization initiator; and (D) a solvent, wherein 1 the polyamic acid is such that when the repeating unit represented by the formula (1) is defined as a unit molecular weight, a unit molecular weight per carboxyl group (unit molecular weight/COOH) falls within a range of from 200 to 300, and 2 the photosensitive resin composition permits the formation of a polyimide film having a residual stress of 40 MPa or lower and a coefficient of thermal expansion of 30 ppm/.degree. C.

Abstract: There is provided a lubricating polymer-containing liquid which comprises a film-forming lubricating polymer, preferably a fluoropolymer, and a liquid medium predominantly comprised of cyclic hydrofluorocarbon wherein said lubricating polymer is dissolved or dispersed. A lubricative polymer film of good performance is formed by coating, for example, a magnetic recording hard disk, an ink jet recording head or a cleaning blade of an image-forming device with the lubricating polymer containing liquid, and then removing the liquid medium.

Abstract: A diene rubber comprised of a conjugated diene homopolymer or a conjugated diene/aromatic vinyl copolymer; the homopolymer or copolymer having on at least one end of its polymer chain a quaternary ammonium group to which four carbon atoms have been bound; at least 10% of the bound conjugated diene units being a vinyl bond; and the homopolymer or copolymer further having a weight average molecular weight (Mw) of 100,000 to 2,000,000. This rubber exhibits well reduced heat build-up, which is an index of a well reduced rolling resistance, and having tensile strength and abrasion resistance.

Abstract: Disclosed herein are an aromatic vinyl-conjugated diene block copolymer composed of a bound aromatic vinyl unit and a bound conjugated diene unit and containing at least a block aromatic vinyl segment, wherein:(1) a content of the bound aromatic vinyl unit in the block copolymer is 5 to 60 wt.

Abstract: A monomer for a shell or a mixture of at least two monomers for a shell was suspension polymerized in the presence of core particles and a polymerization initiator to obtain polymer particles, wherein said core particles are formed of a polymer obtained by polymerization of a monomer for a core or a mixture of at least two monomers for a core and containing a colorant, wherein said monomer for a shell or mixture of monomers for a shell is one which gives upon polymerization a polymer having a glass transition temperature higher than that of the polymer forming the core particle, and wherein said polymerization initiator is represented by the following formula 1: ##STR1## wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 independently represent oxygen atom, sulfur atom, >NR (wherein R is hydrogen atom, alkyl group, or group); R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.

Abstract: A polymerized toner of core-shell structure, comprising core particles composed of colored polymer particles, which comprise a polyfunctional ester compound formed of a trifunctional or still higher polyfunctional polyhydric alcohol and a carboxylic acid, and a colorant, and shell which is formed of a polymer having a glass transition temperature higher than that of a polymer component making up the core particles and covers each of the core particles, a production process thereof, an image forming process comprising using the polymerized toner, and an image forming apparatus containing the polymerized toner.

Abstract: A copolymer latex with a total solids content of at least 67% by weight, which is characterized by having a viscosity of 2,000 centipoises or less as measured with a BM viscometer under the conditions of total solids content of 67% by weight and at room temperature, is provided. Such a low viscosity and high solids-content copolymer latex is produced through an emulsion polymerization in which the method of use of the emulsifier and the amount thereof are controlled following specific conditions.

Abstract: A plant growth regulator comprising as the active ingredients gibberellin and a jasmonic acid ester represented by the following formula (1): ##STR1## wherein R.sup.1 and R.sup.2 represent hydrocarbon groups. Gibberellin and the jasmonic acid ester are applied as a mixture, or as single agents each containing one of the two compounds, which are applied concurrently, or separately by a procedure wherein, while the earlier applied one is still in force, the other is applied.

Abstract: Disclosed herein are a diene rubber composition comprising 100 parts by weight of a diene rubber component composed of 10-100 wt. % of an amino group-containing diene copolymer rubber (A) having a composition (based on the bound amount) of 40-99.95 wt. % of a conjugated diene monomer, 0.05-20 wt. % of an amino group-containing monomer and 0-55 wt. % of an aromatic vinyl monomer, and 0-90 wt. % of another diene rubber (B), and 10-150 parts by weight of silica having a specific surface area of 50-220 m.sup.2 /g as determined by nitrogen absorption (BET method), and having excellent heat build-up resistance, tensile properties, abrasion properties and processability, and a preparation method thereof.

Abstract: This invention provides a diene rubber composed of 40 to 99.99% by weight of conjugated diene units, 0.05 to 20% by weight of amino-containing vinyl monomer units, 0.05 to 20% weight of hydroxyl-containing vinyl monomer units, and 0 to 50% by weight of other copolymerizable monomer units, and having a Mooney viscosity (ML.sub.1+4, 100.degree. C.) of 10 to 200. This diene rubber yields a vulcanized rubber showing improvements in heat build-up, tensile strength, abrasion resistance and processability.

Abstract: A tube-line pressure sensor of a medical-appliance driving apparatus detects the interior pressure of a tube line. If the pressure detected by a tube-line pressure sensor is equal to or less than a predetermined value, a first solenoid valve is closed, while a second solenoid valve is opened, whereby a gas is supplied from a secondary gas tank to the tube line. The amount of gas supplied to the tube line is calculated based on a pressure change in the tank detected by a tank pressure sensor. In actual use, natural gas leakage during normal operation can be clearly distinguished from abnormal gas leakage due to an accident. The interior pressure of the tube line is detected at a time when the balloon is about to inflate from the deflated state, and a gas supply system supplies the driving gas to the tube line so that the detected pressure becomes a preset pressure value. A controller can change the preset pressure value.

Abstract: The present invention provides plant growth promoters each comprising, as an active ingredient, a jasmonic acid derivative represented by the following formula: ##STR1## wherein R.sup.1 represents a pentyl group or a pentenyl group and R.sup.2 represents a hydrogen atom or an alkyl group. These promoters exhibit excellent growth promotion effects particularly on root vegetables, potatoes (tuber crops), cereals, fruit vegetables, fruit trees, flowers and ornamental plants and industrial crops.

Abstract: This invention provides a vulcanizable rubber composition comprising (a) 100 parts by weight of a nitrile-containing highly saturated copolymer rubber obtained by hydrogenating the conjugated diene portions of an unsaturated nitrile-conjugated diene-unsaturated carboxylic acid ester copolymer, (b) 10 to 100 parts by weight of a metallic salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, (c) 0.1 to 30 parts by weight of an organic peroxide vulcanizing agent, and optionally (d) 0.5 to 30 parts by weight of a compound of a group 2A metal in the periodic table. The vulcanized product of this composition is useful as a seal for Freons because it is excellent in low-temperature resistance and resistance to Freon gas permeation and has resistance to the production of cracks in the rubber surface due to the foaming of Freon gas.

Abstract: A medical-appliance driving apparatus is provided. The driving apparatus includes a first pressure sensor, which detects the inside pressure of a first positive pressure tank, and a second pressure sensor, which detects the inside pressure of a second negative pressure tank. A controller calculates the mean value of the pressure data detected by the first and second pressure sensors and if the mean value is greater than the predetermined mean value, a first valve is opened for a predetermined time. If the mean value is smaller than the predetermined mean value, then a second valve is opened for a predetermined time. The controller also calculates the pressure difference between the pressure data detected by the first and second sensors. If the pressure difference is greater than the predetermined difference value, the output level of a pump is lowered. If the pressure difference is smaller than the predetermined difference value, then the output level of the pump is raised.

Abstract: The invention provides a rubber composition comprising 100 parts by weight of a diene rubber (i) and 0.1 to 25 parts by weight of a polyether-based polymer (ii).

Abstract: A molded thermoplastic resin disc substrate specially adapted for use with floating head type recording/reproduction apparatus is provided. The molded disc substrate has surface smoothness characteristics which are the same or better than are provided with mirror polished aluminum discs. The molded disc substrates include a floating head scanning surface wherein the maximum projection height or maximum surface irregularity is less than about 50 nm to reduce or eliminate damage to either the disc or floating head caused by unwanted collisions between them. In a preferred embodiment, the molded disc substrates are molded from a thermoplastic resin composition containing 10000 particles/gram or less of particles having a particle diameter of 0.5 .mu.m or more. In a preferred embodiment, control of particle size and content is achieved by subjecting the resin molding composition to a sequence of filtering steps using filters of decreasing mesh size.

Abstract: A rubber compostion having a reduced heat build-up, which comprises (a) 100 wt. parts of a elastomer capable of being crosslinked by an organic peroxide crosslinking agent, (b) 10-150 wt. parts of a metal salt of an .alpha.,.beta.-ethylenically unsaturated carboxylic acid, (c) 5 to 100 wt. parts of magnesium oxide having a BET specific surface area not larger than 25 m.sup.2 /g, and (d) 0.1 to 30 wt. parts of an organic peroxide crosslinking agent. A roll having an outer peripheral surface portion composed of a vulcanizate of the rubber compositon. The roll has high strenghts and reduced heat build-up, and is especially suitable for use under a high load.

Abstract: There is provided a silica-containing diene rubber composition superior in resiliene (which is an indication of rolling resistance), at least equal, in tensile strength and abrasion resistance, to carbon black-containing diene rubber compositions, and good in processability and hardness property. The silica-containing diene rubber composition is characterized by containing, as the diene rubber component, a hydroxyl group-containing diene rubber having a weight-average molecular weight of 50,000 or more, or a blend of the hydroxyl group-containing diene rubber and other diene rubber.