Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-05-31
2002-10-01
Henderson, Christopher (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S260000, C526S284000, C526S286000, C526S289000, C526S296000, C526S256000, C548S150000, C548S159000, C548S160000, C548S201000, C548S215000, C548S217000, C549S019000, C549S020000, C549S022000, C549S035000, C549S039000, C549S079000, C560S201000, C560S195000, C560S196000, C560S205000, C560S220000, C560S221000, C560S222000, C560S224000
Reexamination Certificate
active
06458908
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sulfur-containing unsaturated carboxylate comprising a sulfur-containing substituent and at least two &agr;,&bgr;-unsaturated carboxylic acid residues via an oxygen atom attached to a secondary or tertiary carbon atom. This invention also relates to a polymerizable composition comprising the sulfur-containing unsaturated carboxylate compound and to an optical component produced by polymerizing the polymerizable composition.
A sulfur-containing unsaturated carboxylate compound according to this invention has a structural feature that it intramolecularly comprises a sulfur-containing substituent and at least two &agr;,&bgr;-unsaturated carboxylic acid residues, which are each attached to a secondary or tertiary carbon atom via an oxygen atom.
The sulfur-containing unsaturated carboxylate compound is useful as a monomer for a polymerizable composition which is photocurable or thermosetting, and is suitably used in a variety of materials such as optical materials and dental materials. An optical component produced by curing the polymerizable composition has excellent optical, thermal and mechanical properties; can be produced in an improved yield; has a higher refractive index; and is useful in various applications such as a variety of plastic lenses (typically, an orthodontic eyeglass), optical information recording media, plastic substrates for a liquid crystal cell and optical-fiber coatings.
2. Description of the Prior Art
Inorganic glasses have a number of excellent physical properties such as excellent transparency and a reduced optical anisotropy, and thus has been used as a transparent optical material in various applications. The glasses, however, have problems such as fragility due to their heavy weight and a poor productivity, leading to recent intensive attempts for developing an optical resin as a substitute for an inorganic glass.
An essential property is transparency for an optical material. To date, various industrial resins with good transparency are known; for example, polymethyl methacrylate (PMMA), bisphenol-A-polycarbonate (BPA-PC), polystyrene (PS), methyl methacrylate-styrene copolymer (MS), styrene-acrylonitrile copolymer (SAN), poly(4-methylpentene-1) (TPX), polycycloolefin (COP), poly(diethyleneglycol bisallylcarbonate) (EGAC) and polythiourethane (PTU).
PMMA exhibits good transparency, weather resistance and moldability, but has drawbacks such as a lower refractive index (n
d
) of 1.49 and a higher absorbency.
BPA-PC exhibits good transparency, heat resistance and shock resistance and a higher refractive index, but a larger chromatic aberration, which limits its application.
PS and MS exhibit good moldability and transparency as well as have a lower absorbency and a higher refractive index, but exhibit lower shock resistance, weather resistance and heat resistance. They have been, therefore, rarely used as an optical resin in practice.
SAN is believed to have a relatively higher refractive index and well-balanced mechanical properties, but it is inadequately heat resistant (heat-distortion point: 80 to 90° C.) to be used as an optical resin.
TPX and COP exhibit good transparency, lower absorbency and good heat resistance, but have drawbacks such as a lower refractive index (n
d
=1.47 to 1.53), lower shock resistance, lower gas barrier property and poor dye-affinity.
EGAC is a thermosetting resin from diethyleneglycol bisallylcarbonate monomer, which is most frequently used for a general-purpose eyeglass. It exhibits good transparency, good heat resistance and a minimal chromatic aberration, but has drawbacks such as a lower refractive index (n
d
=1.50) and lower shock resistance.
PTU is a thermosetting resin prepared by reaction of a diisocyanate with a polythiol, which is most frequently used for a superhigh refractive index eyeglass. It is an excellent material with good transparency, good shock resistance, a higher refractive index and a lower chromatic aberration, but has only one drawback of a longer duration for thermal-polymerization molding (1 to 3 days); i.e. , there is a problem in productivity.
To reduce duration for polymerization or curing for improving the above yield, various procedures have been suggested, including a process for manufacturing an optical lens by optical polymerization using bromine- or sulfur-containing acrylates; for example, JP-A 4-161410 and JP-A 3-217412. According to the process, polymerization can be conducted in a reduced period, but an obtained resin is not satisfactory as an optical component. For example, when it is used as an eyeglass, a resin with a higher refractive index is fragile and has a higher specific gravity. Thus, a material has been earnestly desired, which can solve these problems.
As described above, optical resins of the prior art have good properties, but they have their specific problems to be solved. Thus, it has been earnestly desired to develop an optical resin with good optical, mechanical and thermal properties as well as a good productivity and a higher refractive index.
SUMMARY OF THE INVENTION
Thus, an object of this invention for solving the drawbacks in a conventional optical resin is to provide an optical resin with good optical, mechanical and thermal properties as well as a good productivity and a higher refractive index.
We have intensely attempted to solve the problems to achieve this invention.
This invention provides the followings:
<1> A sulfur-containing unsaturated carboxylate compound comprising a sulfur-containing substituent and at least two &agr;,&bgr;-unsaturated carboxylic acid residues, which are each attached to a secondary or tertiary carbon atom via an oxygen atom.
<2> A sulfur-containing unsaturated carboxylate compound represented by general formula (1).
wherein R
11
represents a bivalent organic group; each X
11
independently represents oxygen, sulfur, —COO— or —(CH
2
)
l
X
12
— (X
12
represents oxygen or sulfur and l is an integer of 1 to 3); each R
12
independently represents hydrogen or alkyl; each R
13
independently represents a sulfur-containing substituent; and each R
14
independently represents an &agr;,&bgr;-unsaturated carboxylate residue.
<3> The sulfur-containing unsaturated carboxylate compound described in <2> prepared by reacting a sulfur-containing dihydroxy compound with an &agr;,&bgr;-unsaturated carboxylic acid derivative represented by general formula (2):
wherein R
11
represents a bivalent organic group; each Xll independently represents oxygen, sulfur, —COO— or —(CH
2
)
1
X
12
— (X
12
represents oxygen or sulfur and l is an integer of 1 to 3); each R
12
independently represents hydrogen or alkyl;,and each R
13
independently represents a sulfur-containing substituent.
<4> The sulfur-containing unsaturated carboxylate compound described in <2> where the &agr;,&bgr;-unsaturated carboxylate residue is selected from the group consisting of (meth)acrylic acid, crotonic acid, tiglic acid, 3,3-dimethylacrylic acid, maleic acid, citraconic acid, 2,3-dimethylmaleic acid, itaconic acid and cinnamic acid residues.
<5> The sulfur-containing unsaturated carboxylate compound described in <2> where the bivalent organic group R
11
is a moiety represented by a formula selected from the group of formulas (3-a), (4-a), (5-a) and (6-a):
wherein R
31
, R
32
, R
33
and R
34
independently represent hydrogen, alkyl, alkoxy, nitro or halogen;
wherein Y
41
represents a single bond, —C(R
41
)
2
— (each R
41
independently represents hydrogen or methyl), —O—, —S— or —SO
2
—; R
42
and R
43
independently represent alkyl, alkenyl, aralkyl, aryl, alkoxy, alkylthio, nitro or halogen; m and n independently represent an integer of 0 to 4;
wherein each R
51
independently represents hydrogen or alkyl;
wherein R
61
and R
62
independently represent hydrogen or alkyl.
<6> The sulfur-containing unsaturated carboxylate compound described in <2> where the sulfur-containing substituent R
13
is a moiety rep
Fujii Ken-ichi
Imai Masao
Ohkuma Tadashi
Otsuji Atsuo
Sugimoto Kenichi
Burns Doane Swecker & Mathis L.L.P.
Henderson Christopher
Mitsui Chemicals Inc.
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