33results about How to "Low photoelastic coefficient" patented technology

The polycarbonate resin of the invention includes a first structural unit derived from a dihydroxy compound represented by a general formula (1), a second structural unit derived from a dihydroxy compound represented by a general formula (2), and a third structural unit derived from at least one dihydroxy compound selected from the group consisting of a dihydroxy compound represented by a general formula (3), a dihydroxy compound represented by a general formula (4), a dihydroxy compound represented by a general formula (5), and a dihydroxy compound represented by a general formula (6), and in which the first structural unit derived from a dihydroxy compound represented by the general formula (1) accounts for 18% by mole or more of the polycarbonate resin. The above general formulae (1) to (6) are described in the specification of the present application.

Provided is a resin composition which contains a polycarbonate resin (A) having main repeating units that include a unit (a-1) represented by formula (a-1) and a unit (a-2) represented by formula (a-2) (wherein W represents an alkylene group having 1-20 carbon atoms or a cycloalkylene group having 6-20 carbon atoms; R represents a branched or linear alkyl group having 1-20 carbon atoms or an optionally substituted cycloalkyl group having 6-20 carbon atoms; and m represents an integer of 0-10) and an acrylic resin (B), and wherein the weight ratio of the polycarbonate resin to the acrylic resinis from 40:60 to 99:1. This resin composition exhibits a single glass transition temperature within the range from 90 DEG C to 150 DEG C, and has excellent transparency, chemical resistance, surfacehardness and heat resistance, while having low photoelastic coefficient.

The present invention provides a birefringent optical film having a high orientation for easily obtaining a desired retardation value and also a small photoelastic coefficient. The birefringent optical film includes at least two kinds of polymer materials. A total of products of Cn and Wn satisfies a numerical formula (1): Sigma(CnxWn)<=20X10<-8 >cm<2> / N (1) where Cn and Wn denote respectively a photoelastic coefficient and a volume fraction of each polymer material, and at least one of the polymer materials of the film has a photoelastic coefficient value of at least 60x10<-8 >cm<2> / N, while at least one of the remaining polymer materials has a negative value of photoelastic coefficient.

Optical films comprising a polyester resin comprising a structural unit (A) of the following formula (1) wherein the content of the structural unit (A) based on the total structural units of the polyester resin is 76 mol % or greater:wherein R1 is a hydrogen atom, CH3, or C2H5; R2 and R3 is each independently a hydrogen atom or CH3; and n is 1, for example, Decahydro-1,4:5,8-dimethanonaphthalene-2-methoxycarbonyl-6(7)-methanol. Retardation films and circularly or elliptically polarizing plates comprising the optical films are also provided.

The present invention provides a thermoplastic acrylic resin of a copolymer comprising 10 to 70% by weight of a repeating unit derived from the particular methacrylate monomer, 5 to 40% by weight of a repeating unit derived from the particular vinyl aromatic monomer, and 20 to 50% by weight of a repeating unit of the particular cyclic acid anhydride, characterized in that a molar ratio (B / A) is within the range of more than 1 to not more than 10, wherein (A) is a content of the repeating unit of the vinyl aromatic monomer and (B) is a content of the repeating unit of the cyclic acid anhydride, and the total amount of remaining monomers to 100 parts by weight of the copolymer is not more than 0.5 part by weight.

An optical glass has refractive index nd greater than 1.59, Abbe number υd greater than 67, low photoelastic coefficient, good chemical stability and excellent grinding property. Fluorophosphate optical glass contains, by cation percentage contents, 30-40% of P5+, 12-20% of Al3+, 30-40% of Ba2+, 1.3-12% of Ca2+, 1-10% of Sr2+, 0-5% of La3+, 0-6% of Gd3+, 0-10% of Y3+, and contains, by anion percentage contents, 25-40% of F+ and 60-75% of O2−. The optical glass is applicable to the manufacturing methods such as high precision molding, secondary hot molding and cold working, in order to produce optical elements like high-performance sphere, aspheric surface, plane lens, prism and raster.

Provided is a thermoplastic resin which includes a constituent unit represented by general formula (I). [In formula (I), R1 represents a hydrocarbon group having 1-6 carbon atoms, and R2 and R3 each independently represent a hydrogen atom or a methyl group.].

The present invention provides a liquid crystal panel having improved contrast ratio in an oblique direction and good display evenness without causing shift or unevenness in retardation values due to shrinkage stress of a polarizer or heat of backlight. A liquid crystal panel according to an embodiment of the present invention includes: a liquid crystal cell; a polarizer arranged on both sides of the liquid crystal cell; a first optical element arranged between one polarizer and the liquid crystal cell; and a second optical element arranged between the other polarizer and the liquid crystal cell, wherein: the first optical element comprises a retardation film containing a styrene-based resin and a polycarbonate-based resin and satisfying the following expressions (1) and (2); and the second optical element has substantially optical isotro. 240nm<=Re(590)<=350nm (1); 0.20<=Rth(590) / Re(590)<=0.80 (2).

A (meth)acrylic resin comprising a (meth)acrylic resin, wherein the (meth)acrylic resin has a repeating unit represented by formula (I) (wherein R1 and R2 independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and R3 represents a ring structure) and a repeating unit represented by formula (II) (wherein R4 and R5 independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and R6 represents an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms).

The present invention is a composition containing a polyester resin containing at least an alicyclic dicarboxylic acid component and an alicyclic diol component, and it is a polyester resin composition which satisfies that a glass transition temperature is 65° C. or more and 90° C. or less, a refractive index at sodium D line is 1.500 or more and 1.570 or less, a titanium element content is 5 ppm or more and 500 ppm or less, a phosphorus element content is 50 ppm or more and 500 ppm or less and a gel fraction is 50% or less. By the present invention, it is possible to obtain a polyester resin composition having a low refractive index and photoelastic coefficient, and in which a thermally degraded foreign substance is reduced.