Korea Institute of Science and Technology

Other

Hyun Nam Cho

Chung Y Kim

Young Chul Kim

Dong Young Kim

Jai Kyeong Kim

Il Seok Choi

Jae-Min Hong

Young Chan Ko

Jae Min Hong

Hoi Wan Yoo

Hyung Jin Jung

Hyung Joon Kim

Han Sang Song

Young Chun Kim

Sang Shik Park

Jong-Bok Kim

Jae-Woong Yu

Sang Ho Bae

Young Jin Heo

Ho Seong Nam

Hyoung-Wook Lee

Kwang Soo Yoo

Young Sei Park

Doo Kyung Moon

Fluorene based polymers and light emitting diodes fabricated with the same as light emitting material

This invention is related to a process for preparing polyester polymers using a composite catalyst comprises the steps of 1) esterifying naphthalene dicarboxylic acid or a dicarboxylic acids containing NDCA or ester derivatives thereof, with ethylene glycol or glycols containing ethylene glycol or derivatives thereof to produce esterified compounds or its low molecular weight polymers; and then 2) continuously polycondensing the obtained esterification product to produce polyester polymers; and wherein the process includes using a composite polymerization catalyst which was prepared by reacting titanium compounds and cobalt compounds in the solution containing at least one alcohol. The process yields high quality polyester polymers having a good color and excellent physical properties. The process can considerably reduce both the esterification time and the polycondensation time.

Process for preparation of polyester-based polymers

Diacetylene-based polymer containing light emitting group and electroluminescent device using the same

The present invention provides a process for preparing polyethylene naphthalate polymers comprising: esterifying a slurry comprising NDCA or a dicarboxylic acid containing NDCA or derivatives thereof, and ethylene glycol or a glycol containing ethylene glycol or derivatives thereof to produce esterification compounds comprising bis (beta-hydroxyethyl) naphthalate or low molecular weight polymers thereof, wherein one or more primary alcohol is added to the slurry; and polycondensing the above resultant esterification compounds to produce polyethylene naphthalate polymers. The process of the present invention allows for the preparation of a slurry more easily and to maximize the manufacturing efficiency. Ultimately, it is possible to increase the productivity of the PEN polymers and to obtain high quality PEN since the method of the present invention has an effect of minimizing side products of the polymerization by reducing the amount of ethylene glycol considerably and of shortening the reaction time of the esterification reaction.

Process for preparing polyethylene naphthalate based polymers by using NDCA or its derivates

A process for preparing polyethylene naphthalate polymer by using a composite catalyst. The process comprises the steps of esterifying a dicarboxylic acid containing 2,6-NDCA, a dicarboxylic ester containing 2,6-NDC or derivatives thereof, with ethylene glycol or a glycol containing ethylene glycol to produce esterification polymers containing bis(beta-hydroxyethyl)naphthalate; continuously polycondensing the obtained esterification polymers to prepare a polymers of polyethylene naphthalate; and wherein the process includes using a composite polymerization catalyst, said composite polymerization catalyst comprising a titanium compound, a phosphorous compound and optionally an antimony compound. The process can considerably reduce both the esterification time and the polycondensation time and provides a good color and excellent physical characteristics.

Process for preparing polyethylene naphthalate based polymers

The present invention relates to a fluorene-based alternating polymer having the following formula (I) to be used as light emitting materials of electroluminescent elements, and further relates to electroluminescent elements having an anode/luminescent layer/cathode structure, in which the fluorene-based alternating polymer is used as light emitting materials of the luminescent layer, or having a transporting and/or reflection layer added thereto, if necessary. ##STR1## wherein R, R', X, Ar and n are defined as above.

Fluorene-based alternating polymers containing acetylene group and

The present invention relates to a fluorene-based alternating copolymer to be used as light emitting materials of electroluminescent elements having the following formula (I), and further relates to electroluminescent elements having an anode/luminescent layer/cathode structure, in which the fluorene-based alternating copolymer used as light emitting materials of the luminescent layer, or having a transporting and/or reflection layer added thereto, if necessary, is ##STR1## where R, R', X, Ar and n are defined in the text.

Fluorene-based alternating copolymers for electroluminescence element

A fabrication method for a liquid crystal alignment layer which has an excellent liquid crystal orientation efficiency and stability, and which can be mass-produced includes coating a thermoplastic polymer film on a transparent electrode to have a thickness of not less than 500.perp., fabricating a temporary cell with a structure of transparent electrode (ITO glass) / polymer film / liquid crystal / polymer film / transparent electrode (ITO glass) by attaching two transparent electrodes having polymer films coated thereon and infusing liquid crystal, fabricating a stack with a structure of transparent electrode (ITO glass)/polymer film /liquid crystal by contacting liquid crystal on the polymer film, heating the temporary cell or the stack at lower than phase separation temperature of a blend of liquid crystal and the polymer film, while applying a magnetic field exceeding 0.2 tesla, and cooling the temporary cell or the stack in the magnetic field at a cooling rate of not more than 100.degree. C. per minute.

Fabrication method for liquid crystal alignment layer by magnetic field

A method for preparing polyester by use of a catalyst. The method comprises the steps of: esterifying either a terephthalic acid, a dicarboxylic acid containing terephthalic acid or derivatives thereof with either ethylene glycol or a glycol containing ethylene glycol, or derivatives thereof to produce an esterification product containing either bis(.beta.-hydroxyethyl) terephthalate, its low molecular weight polymer, or a combination of .beta.-hydroxyethyl terephthalate and its low molecular weight polymer; and continuously polycondensing the obtained esterification product to prepare a polyester, wherein in the said polycondensing step, a composite polymerization catalyst dissolved in an ethylene glycol or an ethylene glycol-containing solution, consisting of a compound of antimony, a compound of titanium, and a compound of tin is used. The method can considerably reduce both the esterification time and the polycondensation time and provides a good color, reduced content of diethylene glycol and reduced concentration of terminal carboxyl groups in the prepared polyesters.

Method for the preparation of polyester by use of composite catalyst

There are a piezoelectric ceramics-polymer composite material and a method for the preparation of the same which comprises 10 to 60% by volume of silane-coated PZT piezoelectric ceramics powder based on the total volume of the composition; at most 3% by volume of carbon powder based on the total volume of the composition; and balance volume of PVdF piezoelectric polymer.

Piezoelectric ceramic-polymer composite material and method for

A process for forming polyesters that comprises the steps of esterifying a terephthalic acid and an ethylene glycol to produce an esterification product containing a bis (betahydroxyethyl) terephthalate, and continuously polycondensing the obtained esterification product to form a polyester. In both the esterifying step and the polycondensing step, a reaction catalyst consisting of a compound of antimony and a compound of titanium is used. The weight ratio of the compound of antimony to the compound of titanium is 0.01 to 100. The process of the present invention can considerably reduce both the esterification time and the polycondensation time and provides good color, reduced diethylene glycol content and reduced condensation of terminal carboxyl groups in the resulting polyesters.

Process for forming polyesters

A method for forming polyesters (polyethylene terephthalate, PET) having a high degree of polymerization with improved color and lower diethylene glycol (DEG) content in a shorter period of time than in known methods. The method according to the invention comprises forming oligomers from ethylene glycol and terephthalic acid by esterification, forming prepolymers having a degree of polymerization ranging from 10 to 50 by polycondensing the resulting oligomers for an optimum time, forming polyesters by polycondensing the oligomers and the prepolymers in a weight ratio ranging from 1:0.1 to 1:90, thereby providing polyesters of improved color and low DEG content in a short time.

Method for forming polyesters

This invention relates to processes for the preparation of polybutylene terephthalate based polymer, which processes produce polymer having excellent color, a small amount of side-product and a high degree of polymerization within a short time. Complex catalyst which is employed comprises antimony compounds and titanium compounds, optionally together with phosphorous based compounds and hindered phenolic, and the catalyst decreases the phenomena that conventional catalysts of tin and titanium based compounds have of making the polymer colored by declining hydrolyzation and heat-stability. The catalyst also decreases the amount of side-product, THF sharply. As a result, improved polybutyleneterephthalate can be prepared.

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Seoul, South Korea

Hyun Nam Cho