Abstract: A conveyance system according to the present invention includes a processing station, first to third conveyance apparatuses arranged in a conveying direction of a work piece. The second conveyance apparatus is provided in the station. The system further includes a lifting apparatus disposed below the second conveyance apparatus in the station, and a processing apparatus in the processing station. The first and second conveyance apparatuses perform returning of the pallet that is empty in a direction reverse to the conveyance direction.

Abstract: A conveyance system according to the present invention includes a processing station, first to third conveyance apparatuses arranged in a conveying direction of a work piece. The second conveyance apparatus is provided in the station. The system further includes a lifting apparatus disposed below the second conveyance apparatus in the station, and a processing apparatus in the processing station. The first and second conveyance apparatuses perform returning of the pallet that is empty in a direction reverse to the conveyance direction.

Abstract: An aromatic polycarbonate composition which has excellent thermal stability and maintains high transparency and a satisfactory hue even at high temperatures. The aromatic polycarbonate composition comprises: a polycarbonate obtained by reacting at least one aromatic dihydroxy compound with a compound capable of incorporating a carbonate bond; and a phosphorus compound represented by the following formula (1): wherein the eight R′s may be the same or different and each represents a hydrogen atom or an optionally substituted, aliphatic or aromatic, univalent group having 1 to 18 carbon atoms.

Abstract: A process for producing an aromatic polycarbonate is described, which comprises melt-polycondensing an aromatic diol compound with a diaryl carbonate compound in the presence of an interesterification catalyst, said interesterification catalyst comprising a quaternary phosphonium salt compound represented by formula (II): ##STR1## wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.6 each independently represent an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, or a cycloalkyl group, and X.sup.l- is an anion selected from the group consisting of a carbonate ion, a phosphate ion, and a tetrahydroxyboron ion, with the letter l indicating the valency of X.

Abstract: A process for producing an aromatic polycarbonate having a weight average molecular weight of from 7,000 to 60,000 is disclosed, comprising melt polycondensing an aromatic diol compound (e.g., bisphenol A) and a diaryl carbonate compound (e.g., diphenyl carbonate) in the presence of a combination of (a) an alkali metal compound and (b) a phosphonium hydroxide compound (e.g., tetraethylphosphonium hydroxide) as an interesterification catalyst. The aromatic polycarbonate has improved heat resistance and hue.

Abstract: A process for producing an aromatic polycarbonate with improved heat resistance comprising melt polycondensing an aromatic diol compound and a carbonic acid diester compound in the presence of an interesterification catalyst and in the co-presence of an organosilicon compound.

Abstract: An aromatic polycarbonate of improved color value and high molecular weight is obtained by the addition of phosphorous acid and/or a phosphorous ester to the melt polycondensation reaction medium containing aromatic diol, carbonate diester and a metal-containing compound as ester interchange catalyst during the polycondensation reaction