Abstract: A manufacturing method for polycarbonate comprising ?I! a process for manufacturing diaryl carbonate from an aromatic hydroxy compound and an aromatic hydroxy compound, ?II! a process for manufacturing polycarbonate by solution polymerization of the diaryl carbonate obtained in ?II! and an aromatic dihydroxy compound in the presence of a catalyst comprising a nitrogen-containing basic compound, and ?III! a process for separating and removing the nitrogen-containing compound from the aromatic hydroxy by-products in ?II! and returning the resultant aromatic hydroxy compounds to process ?I! effectively reuses aromatic hydroxy by-products (e.g., phenols) of polycarbonate manufacturing to manufacture diaryl carbonate, while suppressing the production of alkyl aromatic ethers and then uses this diaryl carbonate to manufacture polycarbonate with good productivity.

Abstract: A monocarbonate represented by the formula (R.sup.1).sub.n Ph--O(R.sup.2 O).sub.m --CO--O--CH.sub.2 --C(R.sup.3)(R.sup.4)(R.sup.5), a lubricating oil containing this monocarbonate, and a process for preparing a composition of this monocarbonate, a monocarbonate to which are bonded, via carbonic acid, two (R.sup.5)(R.sup.4)(R.sup.3)C--CH.sub.2 -- groups and a monocarbonate to which are bonded, via carbonic acid, two (R.sup.1).sub.n Ph--(OR.sup.2).sub.m -- groups. The monocarbonate exhibits excellent lubricating property, cleaning property and electrically insulating property, exhibits excellent compatibility with hydrogenated fluorocarbons such as R-134a, and can be favorably used as a lubricating oil for refrigerators such as electric refrigerators and air conditioners for room.

Abstract: A lubricating oil containing an aromatic ether compound represented by the general formula, (R.sup.1).sub.n Ph--O-- (R.sup.2 O).sub.m --R.sup.3, wherein R.sup.1 stands each independently for a particular hydrocarbon group, an etheric oxygen-containing hydrocarbon group, an alkoxyl group, or a halogen-substituted hydrocarbon group, R.sup.2 stands each independently for an alkylene group having 2 to 4 carbon atoms, R.sup.3 stands for a hydrocarbon group having 1 to 12 carbon atoms, Ph stands for an aromatic substituent, n stands for an integer of from 1 to 5, and m stands for an integer of from 1 to 30. The lubricating oil has excellent lubricating property, cleaning property and electrically insulating property, exhibits excellent sealing property owing to its high viscosity and wear resistance, and further exhibits excellent compatibility with R-134a, etc. The lubricating oil can be favorably used for the refrigerators such as of electric refrigerators and room air conditioners that use R-134a as a coolant.

Abstract: A triphenol type compound represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently represent hydrogen, a halogen, a C.sub.1 -C.sub.5 alkyl group or a C.sub.1 -C.sub.5 alkoxy group.The triphenol type compound can be used, as a branching agent, for the production of a polycarbonate comprising (A) a carbonic acid component unit, (B) a divalent phenol component unit, and (C) a triphenol type compound component unit derived from the above-mentioned triphenol type compound. The triphenol type compound unit (C) is used in an amount of 0.01 to 10 mole %, based on the divalent phenol component unit (B) and the intrinsic viscosity [.eta.], determined at 25.degree. C. in methylene chloride, of the polycarbonate is 0.4 to 1.0 dl/g and the glass transition temperature (Tg), determined by a differential scanning type calorimeter is 150.degree. C. to 300.degree. C.

Abstract: A triphenol type compound represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently represent hydrogen, a halogen, a C.sub.1 -C.sub.5 alkyl group or a C.sub.1 -C.sub.5 alkoxy group.The triphenol type compound can be used, as a branching agent for the production of a polycarbonate comprising (A) a carbonic acid component unit, (B) a divalent phenol component unit, and (C) a tripenol type compound component unit derived from the above-mentioned triphenol type compound. The triphenol type compound unit (C) is used in an amount of 0.01 to 10 mole %, based on the divalent phenol component unit (B) and the intrinsic viscosity [.eta.], determined at 25.degree. C. in methylene chloride, of the polycarbonate is 0.4 to 1.0 dl/g and the glass transition temperature (Tg), determined by a differential scanning type calorimeter is 150.degree. C. to 300.degree. C.