Tokuyama Corporation

Nec Corporation

Kayaba Industry Company, Ltd.

Tokuyama Dental Corporation

Tadashi Hara

Junji Momoda

Yuichiro Kawabata

Tsuneyoshi Tanizawa

Katsuhiro Mori

Hironobu Nagoh

Hideki Kazama

Hironobu Akizumi

Takeshi Suzuki

Tomonori Matsunaga

Shingo Matsuoka

Mutsumi Kashimura

Koichi Tada

Hiroshi Suga

Rumiko Shimada

A steering damper comprises two oil chambers (R, R) delimited in a housing () by a partitioning member (), and a damping valve () which imposes a drag on a flow of working oil between the two oil chambers (R, R). By further comprising an oil passage () connecting the two oil chambers (R, R), a pair of check valves () which prevents oil flow from each of the two oil chambers (R, R) into the oil passage (), and a bypass passage () connected to the oil passage () between the pair of check valves () and having an opening that opens onto the interior of the housing () in the vicinity of the neutral position of the movable partitioning member (), the steering damper enables the movable partitioning member () to return quickly towards the neutral position.

Steering damper

A photopolymerization initiator comprising (A) an &#x3b1;-diketone compound such as camphorquinone, (B1) an aliphatic amine compound such as triethanolamine or N-methyldiethanolamine, (B2) an aromatic amine compound such as ethyl p-dimethylaminobenzoate or N,N-dimethyl p-toluidine, and (C) a triazine compound substituted with a trihalomethyl group, such as 2,4,6-tris(trichloromethyl)-s-triazine or 2-phenyl-4,6-bis(trichloromethyl)-s-triazine. The photopolymerization initiator remains stable against the environmental light such as the indoor illumination light from a fluorescent lamp or the dental light illuminating the interior of the oral cavity, is excellently handled, is quickly cured by the irradiation with an intense light emitted from a light irradiator for polymerization, provides a cured body having excellent properties, can be stably preserved even at high temperatures, and is very useful as a dental composite resin.

Photopolymerization initiator

A method of preparing a sulfur-containing compound having at least one thio group in the molecules by reacting a thiol compound with an organic compound having at least one functional group capable of forming a thio group in the molecules upon reacting with a mercapto group in the presence of a basic compound, wherein the number of moles of water contained in the reaction system is set to be not larger than 7.5 times as large as the number of moles obtained by multiplying the number of moles of the thiol compound to be reacted by a number of mercapto groups present in one molecule of the thiol compound.

Process for production of sulfur compounds

There is disclosed a polymerizable sulfur-containing (meth)acrylate, it has a high refractive index, a great Abbe's number and excellent light resistance and is suitable for the production of a transparent resin which rarely smells at the time of molding and is further excellent in storage stability. A polymerizable composition containing the (meth)acrylate and an optical lens which is a cured product of the composition are also disclosed.

Polymerizable sulfur-containing (meth) acrylate, polymerizable composition and optical lens

A photochromic polymerizable composition comprising (a) a polyfunctional (meth)acrylate monomer, (b) at least one kind of chromene compound selected from the group consisting of three kinds of chromene compounds represented by particular structural formulas, and (c) a compound having at least one or more epoxy groups in the molecules. The photochromic polymerizable composition offers a photochromic material that exhibits little initial color and excellent photochromism resistance suited for use as lenses for spectacles.

Photochromic polymerizable composition

A photochromic compound featuring a large fading rate to prevent a change in the color tone at the time of fading, exhibiting little color after aged, and exhibiting good durability in the photochromic property. The photochromic compound is a novel chromene compound having a substituted phenyl group at the second position of the naphthopyrane ring and an alkyl group at the fifth position thereof, and is represented by, for example, the following formula,

Chromene compound

The present invention relates to a photochromic curable composition suited for the production of a photochromic cured product having excellent optical properties such as a high refractive index and a large Abbe's number, having favorable photochromic properties such as a large color density, and having good fatigue resistance, and to a photochromic lens obtained by curing the photochromic curable composition. The photochromic curable composition is characterized by comprising 100 parts by weight of a polymerizable monomer containing at least 10% by weight of a sulfur-containing (meth)acrylate polymerizable monomer represented by the following general formula (1),

Photochromic curable composition

The present invention relates to a novel chromene compound having favorable photochromic properties, developing a color of a high density, exhibiting a small degree of initial color and permitting the color to quickly fade. The novel chromene compound has an amino group that may be substituted for a sixth position of a naphthopiran ring, has electron-donating groups at para-positions of the two phenyl groups bonded to the third position, and has at least one or more electron-attracting groups at meta-positions of the phenyl groups, and is represented, for example, by the following formula, ##STR1##

A photochromic compound which is initially colored less, exhibits excellent durability and features high color density and high color fading rate, and a photochromic material thereof. The photochromic compound basically has two aromatic heterocyclic groups or an aromatic heterocyclic group and a naphthyl group at the third position, and has a benzene ring that is condensed at the f-th position.

Chromene compounds and photochromic materials

Polymerizable composition, organic glass and ophthalmic lens

A lock processing system which judges locking requests from a plurality of processors. The lock processing system contains two system control units. Locking or unlocking information is transferred between the two system control units. The lock processing system stores the information transferred between the two system control units and judges whether there is a conflict for locking or unlocking. The lock processing system dispenses with hardware otherwise needed for transferring between system control units.

Lock processing system

In order to simplify a hardware arrangement for obtaining error information in a pipelined data processing system which includes serially coupled stages, two separate (first and second) error signal storage means are provided. The first error signal storage means has a plurality of one-bit (for example) memory cells which are respectively assigned to the pipeline stages. The first error signal storage means defines one pipeline stage in which an error is initially detected. The second error signal storage means responds to an error detection signal and receives error analyzing information from the last stage of the pipeline.

Growing community of inventors

Tokuyama, Japan

Tadashi Hara