Mitsubishi Gas Chemical Company, Inc.

Teruo Kamura

Hiroshi Horikoshi

Yoshihiko Nishimori

Motoharu Takeuchi

Eiji Koshiishi

Hiroyuki Okada

Masahiro Johno

Yuichi Yoshimura

Akinobu Horita

Yousuke Imagawa

Kazuya Zenyoji

Rie Sakata

Naotsugu Shimoda

The present invention provides a polythiol composition containing, as the main component, a polythiol compound (a) having two or more mercapto groups, and containing 0.5% by mass or less of a nitrogen-containing compound (b) in which at least one mercapto group in the polythiol compound (a) is substituted with a group represented by formula (1). 

Polythiol composition and method for producing same

According to one preferred embodiment of the present invention, a composition for optical materials, which contains a compound represented by formula (1) and a compound represented by formula (2), is able to be provided. This composition for optical materials enables stable storage of a compound represented by formula (2) at low cost, and also enables stable storage thereof with respect to temperature change. In addition, this composition for optical materials enables the achievement of an optical material which has good light resistance. (In formula (1), in represents an integer of 0-4; and n represents an integer of 0-2.) (In formula (2), m represents an integer of 0-4; and n represents an integer of 0-2.)

Sulfur compound and composition for optical materials containing same

According to the present invention, a polythiol compound having a total nitrogen content of 50 to 600 ppm inclusive can be provided. According to the present invention, a method for producing the polythiol compound can also be provided, said method being characterized by comprising the steps of: reacting a polyalcohol with thiourea to prepare a thiuronium salt; and adding at least one base selected from the group consisting of hydrazine (hydrate), ammonia and an amine and an inorganic base (that is different from hydrazine (hydrate) or ammonia) to the thiuronium salt in the presence of an organic solvent to hydrolyze the thiuronium salt.

Polythiol compound and method for producing same

According to the present invention, it is possible to provide an optical material composition that contains an episulfide compound represented by formula (1) and an episulfide compound represented by formula (2). According to this optical material composition, it is possible to suppress a reduction in the yield rate caused by molding defects, and possible to obtain an optical material having excellent dyeability. (In formula (1), m and p are each an integer between 0 and 4, and n and q are each an integer between 0 and 2.) (In formula (2), m is an integer between 0 and 4 and n is an integer between 0 and 2).

Episulfide compound and optical material composition containing same

Through an optical material composition containing a compound (a), a compound (b), a polythiol (c) and sulfur (d) according to the present invention, good mold release properties are obtained, and the occurrence of separation mark defects can be suppressed. Compound (a): a compound having the structure represented by formula (1):  Compound (b): a compound having the structure represented by formula (2): 

Optical material composition and method for producing same

According to the present invention, it is possible to provide a thiol compound represented by formula (1): wherein Ris CHSCHCHSH, and Ris hydrogen. In addition, according to the present invention, it is possible to provide a mixture of the thiol compound and 4-mercaptomethyl-1,8-dimercapto-3,6-dithiaoctane, wherein the ratio of the thiol compound is 0.001 to 5.0% by mass.

Thiol compound and composition for optical materials using the same

By using a method for producing a composition for an optical material using (a) sulfur, (b) a compound having two intramolecular episulfide groups, (c) a compound having one or more (preferably two) SH groups, and (d) an amine compound having a specific structure, in which compound (a) and compound (c) are pre-polymerized in the presence of compound (b) using compound (d) as the pre-polymerization catalyst, the present invention provides a polymerizable composition for an optical material in which the viscosity elevation speed during pre-polymerization is slow and the reaction temperature is approximately room temperature, and that has a low viscosity and shows little increase in viscosity. By means of another embodiment of the present invention, it is possible to produce an optical material that has excellent mold release characteristics but has substantially no striae by polymerizing (a) sulfur, (b) a compound having two intramolecular episulfide groups, and (c) a compound having one or more SH groups in the presence of (d) a hindered amine catalyst having a specific structure.

Polymerizable composition for optical material, method for producing same, and method for producing optical material

A composition for an optical material includes (a) a compound having two &#x3b2;-epithiopropyl groups and having a specific structure, (b) a compound having one &#x3b2;-epithiopropyl group and one glycidyl group and having a specific structure, (c) polyisocyanate and (d) polythiol, enables the prevention of the occurrence of such a defect that peeling traces linger on a lens. In the composition for an optical material, an embodiment in which (e) sulfur is additionally contained is preferred. Another embodiment of the present invention is a method for producing an optical material, characterized by adding an onium salt as a polymerization catalyst to the composition for an optical material in an amount of 0.0001 to 10% by mass relative to the total amount of the compound (a), the compound (b), polyisocyanate (c) and polythiol (d) and then polymerizing and curing the resultant mixture.

Composition for optical material, and method for producing same

A curable composition containing an inorganic compound A having sulfur atom and/or selenium atom, a compound B represented by the following formula 1: 

Curable composition

The alicyclic compound of the present invention has a five- or more membered ring structure having an epithioethylene linkage and/or an epidithioethylene linkage, and has tow or more sulfur atoms in its molecule. Optical materials produced by curing the alicyclic compound or a composition containing the alicyclic compound by polymerization show high refractive index.

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Tokyo, Japan

Teruo Kamura