Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: There are a piezoelectric ceramics-polymer composite material and a method for the preparation of the same which comprises10 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; andbalance volume of PVdF piezoelectric polymer.