Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-04-18
2003-03-11
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S420000, C524S419000
Reexamination Certificate
active
06531532
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical material for plastic lenses, prisms, optical fibers, information recording substrates and filters, and, more particularly, to an optical lens such as a plastic lens for glasses.
2. Description of the Related Arts
Plastic materials have widely been used for various optical materials, particularly as lenses of glasses, because of light weight, toughness and easiness of tinting. The properties required for optical materials, particularly for lenses of glasses, are a low specific gravity, excellent transparency, suppressed yellow color and optical properties which are a large refractive index and a large Abbe number. A large refractive index is important to decrease the thickness of a lens. A large Abbe number is important to decrease chromatic aberration of a lens. The present inventors have discovered novel episulfide compounds which can provide optical materials having a small thickness and a small chromatic aberration, i.e., a refractive index of 1.7 or larger and an Abbe number of 35 or larger, as disclosed in the specifications of Japanese Patent Application Laid-Open Nos. Heisei 9(1997)-71580, Heisei 9(1997)-110979 and Heisei 9(1997)-255781. However, since the optical materials discovered above have refractive indices of about 1.71, an optical material having a higher refractive index has been desired.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a composition for optical materials having a large Abbe number and a refractive index exceeding refractive indices of conventional materials and an optical material obtained by curing the composition by polymerization.
As the result of extensive studies by the present inventors to achieve the above object, it was found that using an inorganic compound comprising at least one atom of sulfur atom and selenium atom is advantageous for obtaining a composition having a refractive index exceeding those of conventional materials. The present invention has been completed based on this knowledge.
The present invention provides a composition for optical materials which comprises a mixture of a compound having one or more structures represented by formula (1) in one molecule and one or more inorganic compounds comprising at least one atom of sulfur atom and selenium atom, formula (1) being:
wherein R
1
represents a hydrocarbon group having 1 to 10 carbon atoms, R
2
, R
3
and R
4
each represents hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, Y represents O, S, Se or Te, m represents a number of 1 to 5, n represents a number of 0 to 5 and p represents 0 or 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compound comprising one or more structures represented by formula (1) in one molecule which is used in the present invention provides a large refractive index, a large Abbe number and an excellent balance between these properties when the compound is used for an optical material. In formula (1), R
1
preferably represents methylene group or ethylene group and R
2
, R
3
and R
4
each preferably represents hydrogen atom. Y represents O, S, Se or Te and preferably S, Se or Te when a still larger refractive index is desired. m represents a number of 1 to 5, preferably 1 or 2 and more preferably 1. n represents a number of 0 to 5, preferably a number of 0 to 4 and more preferably 0 or 1. p represents 0 or 1 and preferably 1.
As the compound having one or more groups represented by formula (1) in one molecule which is used in the present invention, any compound satisfying this condition can be used. Compounds having two or more groups represented by formula (1) in one molecule are preferable. Specific examples of the compound having the structures represented by formula (1) include the following compounds:
(A) Organic compounds having epithio groups
(B) Organic compounds having epithioalkyloxy groups
(C) Organic compounds having epithioalkylthio groups
(D) Organic compounds having epithioalkylseleno groups
(E) Organic compounds having epithioalkyltelluro groups
Organic compounds (A), (B), (C), (D) and (E) have a chain backbone structure, branched backbone structure, an alicyclic backbone structure, an aromatic backbone structure or a heterocyclic backbone structure having nitrogen atom, oxygen atom, sulfur atom, selenium atom or tellurium atom. The organic compounds may have a combination of epithio group, epithioalkyloxy groups, epithioalkylthio groups, epithioalkylseleno group and epithioalkyltelluro group in one molecule. The organic compound may also have sulfide linkages, selenide linkages, telluride linkages, ether linkages, sulfone linkages, ketone linkages, ester linkages, amide linkages or urethane linkages.
Preferable examples of the organic compound having epithio groups of compound (A) include compounds obtained by replacing one or more epoxy groups in compounds having epoxy groups (not glycidyl groups) with epithio groups. Specific examples of the above compound include:
Organic compounds having a chain aliphatic backbone structure such as 1,1-bis(epithioethyl)methane, 1-(epithioethyl)-1-(&bgr;-epithiopropyl)methane, 1,1-bis(&bgr;-epithiopropyl)methane, 1-(epithioethyl)-1-(&bgr;-epithiopropyl)ethane, 1,2-bis(&bgr;-epithiopropyl)ethane, 1-(epithioethyl)-3-(&bgr;-epithiopropyl)butane, 1,3-bis(&bgr;-epithiopropyl)propane, 1-(epithioethyl)-4-(&bgr;-epithiopropyl)pentane, 1,4-bis(&bgr;-epithiopropyl)butane, 1-(epithio-ethyl)-5-(&bgr;-epithiopropyl)hexane, 1-(epithioethyl)-2-(&ggr;-epithiobutylthio)-ethane, 1-(epithioethyl)-2-[2-(&ggr;-epithiobutylthio)ethylthio]ethane, tetrakis-(&bgr;-epithiopropyl)methane, 1,1,1-tris(&bgr;-epithiopropyl)propane, 1,3-bis(&bgr;-epithiopropyl)-1-(&bgr;-epithiopropyl)-2-thiapropane and 1,5-bis(&bgr;-epithiopropyl)-2,4-bis(&bgr;-epithiopropyl)-3-thiapentane;
Compounds having alicyclic backbone structures including:
Compounds having one alicyclic structure such as 1,3- and 1,4-bis(epithioethyl)cyclohexanes, 1,3- and 1,4-bis(&bgr;-epithiopropyl)cyclohexanes, 2,5-bis(epithioethyl)-1,4-dithiane, 2,5-bis(&bgr;-epithiopropyl)-1,4-dithiane, 4-epithioethyl-1,2-cyclohexene sulfide and 4-epoxy-1,2-cyclohexene sulfide; and
Compounds having two or more alicyclic structures such as 2,2-bis[4-(epithioethyl)cyclohexyl]-propane, 2,2-bis[4-(&bgr;-epithiopropyl)cyclohexyl]propane, bis[4-(epithioethyl)cyclohexyl]methane, bis[4-(&bgr;-epithiopropyl)cyclohexyl]methane, bis[4-(&bgr;-epithiopropyl)cyclohexyl]sulfide and bis[4-(epithioethyl)cyclohexyl]sulfide; and
Compounds having aromatic backbone structures including:
Compounds having one aromatic backbone structure such as 1,3- and 1,4-bis(epithioethyl)benzenes and 1,3- and 1,4-bis(&bgr;-epithiopropyl)benzenes;
Compounds having two or more aromatic backbone structures such as bis[4-(epithioethyl)phenyl]methane, bis[4-(&bgr;-epithiopropyl)phenyl]methane, 2,2-bis[4-(epithioethyl)phenyl]propane, 2,2-bis[4-(&bgr;-epithiopropyl)phenyl]propane, bis[4-(epithioethyl)phenyl]sulfide, bis[4-(&bgr;-epithiopropyl)phenyl]sulfide, bis[4-(epithioethyl)phenyl]sulfone, bis[4-(&bgr;-epithiopropyl)phenyl]sulfone, 4,4′-bis(epithioethyl)biphenyl, 4,4′-bis(&bgr;-epithiopropyl)biphenyl and the like compounds; and
Compounds obtained by replacing at least one hydrogen atom in the epithio group in the above compounds with methyl group.
Preferable examples of the organic compound having one or more epithioalkyloxy groups of compound (B) include compounds obtained by replacing one or more glycidyl groups in epoxy compounds derived from an epihalohydrin with epithioalkyloxy groups (thioglycidyl groups). Specific examples of the above epoxy compound include epoxy compounds derived from phenols which are produced by condensation of epihalohydrins with polyhydric phenols such as hydroquinone, catechol, resorcinol, bisphenol A, bisphenol F, bisphenol sulfone, bisphenol ether, bisphenol sulfide, halogenated bis
Horikoshi Hiroshi
Niimi Atsuki
Takeuchi Motoharu
Yoshimura Yuichi
Antonelli Terry Stout & Kraus LLP
Cain Edward J.
Mitsubishi Gas Chemical Company Inc.
Wyrozebski Katarzyna
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