Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2002-05-20
2004-06-15
Boykin, Terressa (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C264S176100, C264S219000, C359S642000, C428S411100, C428S412000, C528S198000
Reexamination Certificate
active
06750313
ABSTRACT:
TECHNICAL FIELD
The present invention relates to one or more than one resin composition having a low level of optical dispersion and a high refractive index and a molded product containing the same.
BACKGROUND ART
Various materials have been applied as colorless and transparent materials according to a variety of uses including optical lenses, functional optical films, disc substrates and the like, but those materials are required to have even higher and better function and performance due to the rapid developments in the fields of health-care and electronics.
An optical lens is one of the health-care applications for optical materials, and the development of these materials has been actively carried out to provide a thinner, lighter and more fashionable lens, and presently, resin lenses command a 90% share of the market due to their advantages such as high impact resistance and light weight.
Conventional resins for optical lenses can be divided into three main groups, i.e. CR39, acrylic, and urethane. Many kinds of resins have been developed for commercial use with the objective of a low level of optical dispersion and a high refractive index. All of these resins are thermosetting, and they are molded into optical lenses by a cast molding process; however, this method has a problem of high manufacturing costs, since the polymerization time is long and a subsequent annealing step is required. The use of a thermoplastic resin such as polycarbonate for an optical lens can reduce the production cost, to a much lower level compared to that of the thermosetting resin due to its good moldability; however, the performance of the resulting vision-correcting eye glasses is insufficient due to the resin's low refractive index (1.58). There are many thermoplastic resins which are known to have higher refractive indices than that of the polycarbonate, but they have problems when used for optical lenses, such as a high level of optical dispersion and staining.
On the other hand, transparent and colorless thermoplastic resins such as polycarbonate have also been widely employed in the field of electronics. Such applications include an optical film such as an optical retardation film and a substrate for a disc. The optical retardation film is one of the important components of a full-color reflective liquid crystal display and determines the contrast, but currently-employed polycarbonates (Japanese Patent Laid-Open Nos. Hei 4-204503, and Hei 9-304619) possess less-than-satisfactory wavelength dispersion characteristics. For a full color reflective liquid crystal display of high contrast, improvement in the wavelength dispersion characteristics of the resin film used as the optical retardation film has been one of the technical problems to be solved.
DISCLOSURE OF THE INVENTION
The present invention aims at providing a resin composition having excellent optical characteristics including high transparency, high refractive index, and low optical dispersion, and a molded product thereof. In order to solve the above-mentioned problems, the present invention has the following construction. Namely, a resin composition comprised of a carbonate residue, a phosphonic acid residue represented by the following structural formula (1), and a dihydric phenol residue represented by the following structural formula (2) is provided, wherein the mol fractions of the phosphonic acid residue and the carbonate residue satisfy equation (3).
[In structural formula (1), R1 represents an organic group, X1 represents oxygen, sulfur or selenium, and the resin composition may contain two or more different phosphonic acid residues having different R1 or X1. In structural formula (2), R2 is independently selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbyl group and a nitro group, p and q are integers such that p+q=0 to 8, and the hydrocarbyl group is selected from the group consisting of an aliphatic group having 1-20 carbon atoms, and an aromatic group. Y1 is selected from the group consisting of a single bond, an oxygen atom, a sulfur atom, an alkylene group, an alkylidene group, a cycloalkylene group, a cycloalkylidene group, a halo-substituted alkylene group, a halo-substituted alkylidene group, a phenylalkylidene group, a carbonyl group, a sulfone group, an aliphatic phosphine oxide group, an aromatic phosphine oxide group, an alkylsilane group, a dialkylsilane group, and a fluorene group. The resin composition may contain two or more different dihydric phenol residues having different R2 or Y1.]
1>(
a
)/{(
a
)+(
b
)}≧0.5 (3)
[In equation (3), (a) represents the number of moles of the phosphonic acid residues, and (b) represents the number of moles of the carbonate residues.]
According to the present invention, a resin composition which comprises a phosphonic acid residue represented by the following structural formula (4), and a dihydric phenol residue represented by the following structural formula (5) is also provided.
[In structural formula (4), R3 represents an organic group, X2 represents sulfur or selenium, and the resin composition may contain two or more different phosphonic acid residues having different R3 or X2. In structural formula (5), R4 is independently selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbyl group and a nitro group, and p and q are integers such that p+q=0 to 8, and the hydrocarbyl group is selected from the group consisting of an aliphatic group having 1-20 carbon atoms, and an aromatic group. Y2 is selected from the group consisting of a single bond, an oxygen atom, a sulfur atom, an alkylene group, an alkylidene group, a cycloalkylene group, a cycloalkylidene group, a halo-substituted alkylene group, a halo-substituted alkylidene group, a phenylalkylidene group, a carbonyl group, a sulfone group, an aliphatic phosphine oxide group, an aromatic phosphine oxide group, an alkylsilane group, a dialkylsilane group, and a fluorene group. The resin composition may contain two or more different dihydric phenol residues having different R4 or Y2.]
BEST MODE FOR CARRYING OUT THE INVENTION
As a result of extensive examination in search of a thermoplastic resin having a high refractive index and low dispersion, the present inventors have found that a colorless and transparent thermoplastic resin having a high refractive index and low dispersion can be obtained by introducing a structure having a pentavalent phosphorus atom, in particular a phosphonic acid structure, into the main chain of a polymer. Equation (3) represents the copolymerization fraction of the phosphonic acid residue, wherein (a). represents the number of moles of the phosphonic acid residue represented by structural formula (1), and (b) represents the number of moles of the carbonate residue. When the mol fraction of the phosphonic acid residue represented by formula (1) is below 0.5, the polymer does not show a high refractive index, thereby the advantages of the present invention are barely attained. A mol fraction of the phosponic acid residue within the range of [(a)/{(a)+(b)}]≧0.75 is preferred.
Abbe numbers are generally employed as an index to show the level of optical dispersion of an optical material and calculated according to the following equation (6).
Abbe number (&ngr;
d
)=(
nd
−1)/(
nf−nc
) (6)
Wherein, nd represents the d-line refractive index (wavelength: 587.6 nm), nf represents the f-line refractive index (wavelength: 656.3 nm), and nc represents the c-line refractive index (wavelength: 486.1 nm).
Therefore, higher Abbe numbers are indicative of lower dispersion.
Various resins having phosphorus-type functional groups are known; particularly, the resins containing phosphonic acid ester groups in the main chain are referred to as polyphosphonates (K. S. Kim, J. Appl. Polym. Sci., 28, 1119 (1983); Y. Imai et al, Makromol. Chem., Rapid Commun., 1, 419 (1980); U.S. Pat. No. 3,719,727), and have been a
Ishinabe Ryouichi
Kumagai Takuya
Takanishi Keijiro
Boykin Terressa
Piper Rudnick LLP
Toray Industries Inc.
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