Abstract: An optical waveguide including a core layer formed of a polymer, and a cladding layer placed in proximate to the core layer, the cladding layer being formed of a polymer having a refractive index smaller than the refractive index of the polymer for the core layer, wherein the polymers for the core and cladding layers are selected from the copolymers having the formula (1): where X is Y is and n is a mole fraction in the range of 0.05≦n<1.

Abstract: A polyimide for optical communications has a monomer, represented by the formula (1), as a repeating unit: ##STR1## wherein X.sub.1 and X.sub.2 are independently selected from the group consisting of halogen atom, halogenated alkyl group, halogenated aromatic ring group, --NO.sub.2, --OR.sup.1 and --SR.sup.1 (where R.sup.1 is selected from the group consisting of halogenated alkyl and halogenated aromatic ring groups); and Z is selected from the group consisting of divalent halogenated aliphatic hydrocarbon, divalent halogenated aliphatic cyclic hydrocarbon and divalent halogenated aromatic hydrocarbon. Thus, light absorption loss at a near infrared light wavelength range can be minimized by using the polyimide, so that the polyimide is very useful as an optical material in the optical communications field using light of a near infrared light region.

Abstract: A bis(disubstitutedmaleimide) derivative and a polyetherimide for optical communications and the polyetherimide formed therefrom are described. The polyetherimde has a high refractive index, so that when using such polyetherimide as a material for a core of an optical fiber, the range of the materials that can be selected for the cladding becomes wide. Also, a coating property and adhesion to a substrate are improved, thereby providing a good film forming property and thermal stability. Also, because the polyetherimide can minimize optical loss at a near infrared wavelength range, the polyetherimide is very useful as an optical material in the optical communications field adopting the light of near infrared wavelength.

Abstract: A bis(trisubstitutedtrimellitic anhydride) derivative and a polyesterimide for optical communications, the polyesterimide being formed therefrom. The polyesterimide has a high refractive index, so that when using such polyesterimide as a material for a core of an optical fiber, the range of materials that can be selected for the cladding becomes wide. Also, a coating property and adhesion to a substrate are improved, thereby providing a good film forming property and thermal stability. Also, because the polyesterimide can minimize optical loss at a near infrared wavelength range, the polyesterimide is very useful as an optical material in the optical communications field adopting the light of near infrared wavelength.

Abstract: A polyamideimide for optical communications, having a minimum light absorption loss in a near infrared light wavelength range, high thermal stability and excellent film processibility, and a method for preparing the same are provided. The polyamideimide has a higher refractive index than the conventional fluorinated polyamideimide. Thus, when using such polyamideimide as a material for a core of an optical fiber, the selection range on the material for cladding becomes wide. Also the coating property and adhesiveness to a substrate are improved, thereby providing a good film processibility and heat resistance.

Abstract: A polyarylether of the formula (VIII) ##STR1## wherein wherein Z' is 1-3 optionally substituted rings selected from the group consisting of an aromatic ring, a hetero aromatic ring or an aliphatic ring.A is --R.sub.1 --Z--Y in which R.sub.1 is H, C.sub.1 -C.sub.30 -alkyl or -aralkyl or phenyl, Z is a direct bond or CH.sub.2, S, O or NH, Y is CH.sub.3, OR.sub.3, SR.sub.3, NHR.sub.3, N(R.sub.3).sub.2, COOR.sub.3, COOM, SO.sub.3 R.sub.3 or SO.sub.3 M in which R.sub.3 is C.sub.1 -C.sub.30 alkyl and M is alkali metal,produced from 3,6-dihalogen- or -dintro-1,2,4,5-diimide having an N,N-substituent and which is suitable for use as a monomer for high temperature structural and functional polymers, and a process for producing the same are disclosed.

Abstract: A polyamideimide for optical communications, having a minimum optical loss in a near infrared light wavelength range, high thermal resistance and good film processibility, and a method for preparing the same are provided. The polyamideimide is very useful as an optical material in the optical communications field adopting the light of near infrared light wavelength.

Abstract: Derivatives of (3-oxoisoindolin-1-ylidine)propandinitrile, and a method for preparing the derivatives, are disclosed herein. The (3-oxoisoindolin-1-ylidine)propandinitrile derivatives can be prepared easily and at low cost. Also, the derivatives show good heat resistance at temperatures required for manufacturing an electro-optic device, and can minimize light loss at a near infrared light wavelength range by replacing hydrogen of the C--H bond with halogen atom. As a result, the derivatives of the present invention are useful as an optical material for an electro-optic device. In addition, the (3-oxoisoindolin-1-ylidine)propandinitrile derivatives can be used as an intermediate for synthesizing a new compound having good electro-optic characteristics and heat resistance.

Abstract: The disclosure describes a process for preparing a polyamideimide resin having high molecular weight in a simple manner wherein major problems of the prior processes such as low heat resistance and low melt flowability are improved. The process comprises condensation of an aromatic tricarboxylic acid anhydride and an aromatic diamine in a polar solvent, subjecting the resulting diimidedicarboxylic acid to acyl halogenating agent treatment to give an intermediate having good reactivity at low temperature, and then subjecting the latter to direct polymerization by using diamine as a nucleophilic agent to give a polyamideimide resin having high molecular weight. The polyamideimide resin prepared by the present invention can be used as major heat resistant structural material in advanced industries and as paint, sheet, adhesives, sliding material, fiber and film having heat resistance.

Abstract: The disclosure describes a cyclohexane-1,2,4,5-diimide derivative which can be used for the production of colorless transparent polymer and novel engineering plastics having good processability and solubility with an excellent physical property, and a process for preparing the same which comprises reacting a bicyclooctene-1,2,4,5-tetracarboxylic anhydride with alkylamine and aniline derivative and then oxidizing the resulting product with ozone, potassium permanganate, ruthenium chloride hydroxide and aqeous hydrogen peroxide under non-basic condition to convert double bond to dicarboxylic acid or dialdehyde without destroying the imide group.

Abstract: A process for preparing polyamideimide resins having high molecular weights as described wherein major problems of prior art processes such as low heat resistance and low melt flowability are improved. Polyamideimide resins having an intrinsic viscosity of 0.4 to 1.50 dl/g as measured on a solution of dimethylacetamide as a solvent at a concentration of 0.5 g/dl at 30.degree. C., are prepared by reacting an aromatic tricarboxylic acid anhydride with an aromatic diamine in N-methyl pyrrolidone solvent in the presence of a first catalyst selected from a group consisting of thionyl chloride, p-toluenesulphonly chloride, sulfuryl chloride, cyanuric chloride and phosphorus trichloride at a temperature of 50.degree. C. to 130.degree. C. over a period of 1 to 5 hours and further reacting the resultant reaction mixture in the presence of a second catalyst which is a compound of the formula (RO).sub.