Korea Research Institute of Chemical Technology

Cheil Industries Inc.

Kil Yeong Choi

Mi Hie Yi

Sung Goo Lee

Jae Heung Lee

Jae Hyun Lee

Seung Su Kim

Sang Sung Woo

Jong Chan Won

Young Taik Hong

Moon Young Jin

Seung Soo Kim

Wenxi Huang

Si Yong Song

Jong Bae Lee

Young Wun Kim

Jong Il Weon

Youn S Don

Provided is a method for quantitative evaluation of mar- and scratch-induced surface damage on polymeric and coating materials. The method for quantitative evaluation of scratch-induced damage on polymeric and coating materials includes: preparing a test specimen of polymeric and coating materials; inducing a scratch damage on the surface of the test specimen; representing the scratch damage formed on the test specimen as corresponding color coordinates; and calculating a quantitated scratch damage index from a combination of a load applied to the surface of the test specimen and the color coordinates corresponding to the scratch damage.

Quantitative evaluation of scratch-induced damages on polymeric and coating materials

Preparation of polyimide foam

A method of preparing polyimide foam produces a foam with excellent flexibility properties. The method of preparing polyimide foam is performed by foaming polyimide percursor which is prepared by employing linear aliphatic diamine and aromatic diamine containing 4 to 12 carbon atoms, at specific weight ration into the esterified reaction mixture prepared by reacting an aromatic carboxylic acid or its anhydride with excess amount of an alcohol compound. The polyimide foam produced by the method described retins superior characteristics of conventional polyimide foams and in addition have excellent flexibility so that it is used widely as adiabatic material, acoustical absorbent and cushion material in the aerospace industry, submarine and express trains etc.

Method of preparing polyimide foam with excellent flexibility properties

The invention herein relates to a novel soluble polyimide resin comprising polyalicyclic structures and the process of preparation of the same, wherein aromatic tetracarboxylic dianhydride and novel aromatic diamine having an polyalicyclic group with various structures are used to yield a novel form of a polyimide resin, which has superior heat-resistance, solubility, and transparency. More specifically, the invention herein relates to a novel polyimide resin having excellent heat-resistance and solubility, which is prepared by means of reacting diamine monomers having a novel chemical structure with various types of aromatic carboxilic dianhydrides, in stead of aromatic diamine used for the preparation of the conventional polyimide resin. As a result, the polymers so obtained had the glass transition temperature of 260.degree. C..about.410.degree. C. and showed a increase in solubility in proportion to the increase in a number of the aromatic rings between two phenyl groups. Further, the polymers herein showed superior solubility at room temperature in various types of organic solvents, e.g., m-cresol, N-methylpyrrolidone or dimethylacetamide.

Soluble polyimide resin comprising polyalicyclic structure

An amorphous polyamide represented by the formula(2) ##STR1## in which each R is at least one alkylene radical having 1 to 10 carbon atoms, R' is an electron acceptor group represented by the formula(3), ##STR2## wherein Y is --C.tbd.N, --NO.sub.2, --SO.sub.2 --R(R.dbd.C.sub.n H.sub.2n+1, n=1 to 20 alkyl derivatives), ##STR3## R' is at least one aliphatic or aromatic divalent group having 2 to 20 carbon atoms, and n is an integer of more than 3, having second order nonlinear optical property, and a method for preparing the polymer by the polycondensation of dicarboxylic acid derivative, having second order nonlinear optical property in its side chain, with diamine are disclosed.

Amorphus polyamides having second order nonlinear optical property, and

This invention relates to melt processable copolymer of etherimideimide/etherimide herein-after identified as PEII/PEI copolymer of following structural formula(I). ##STR1## wherein, R and R' are independently selected from the groups of ##STR2## Ar and Ar' are independently selected from the groups of ##STR3## (wherein, R1 is H or C1-C6 alkyl group,

Melt processable etherimideimide/etherimide copolymer

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Daejeon, South Korea

Kil Yeong Choi