Abstract: A polycarbonate diol composition contains: a polycarbonate diol containing a structural unit (1) derived from a compound (1) represented by the following general formula (1); HO—(CH2)n—OH (1) (n is an integer of 3 to 6) and an aldehyde having 3 or more and 8 or less carbon atoms. A method for producing a polycarbonate diol composition, includes: polycondensing a carbonate compound and a dihydroxy compound composition containing a compound (1) represented by the following general formula (1) and an aldehyde having 3 or more and 8 or less carbon atoms by a transesterification reaction in the presence of a catalyst, to obtain a polycarbonate diol composition containing a polycarbonate diol. A polyurethane is obtained by using this polycarbonate diol composition.

Abstract: A polycarbonate diol contains a structural unit (1) represented by the following general formula (I) and a structural unit (2) represented by the following general formula (II). (In the general formula (I), R represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a hetero atom.) (In the general formula (II), m is an integer of 2 to 20. R2 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom.

Abstract: A polycarbonate diol composition contains: a polycarbonate diol containing a structural unit (1) derived from a compound (1) represented by the following general formula (1); HO—(CH2)n—OH (1) (n is an integer of 3 to 6) and an aldehyde having 3 or more and 8 or less carbon atoms. A method for producing a polycarbonate diol composition, includes: polycondensing a carbonate compound and a dihydroxy compound composition containing a compound (1) represented by the following general formula (1) and an aldehyde having 3 or more and 8 or less carbon atoms by a transesterification reaction in the presence of a catalyst, to obtain a polycarbonate diol composition containing a polycarbonate diol. A polyurethane is obtained by using this polycarbonate diol composition.

Abstract: A control device for automatic transmission includes a flow control mechanism for introducing a part of hydraulic oil discharged from a mechanical oil pump into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrow part provided in a discharge passage in which hydraulic oil discharged from the mechanical oil pump flows becomes larger than a predetermined value. Air mixed into the hydraulic oil is compressed by increasing a line pressure as a differential rotation speed increases when oil temperature of the hydraulic oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or lower than a predetermined engine torque.

Abstract: A control device for automatic transmission includes a flow control mechanism for introducing a part of hydraulic oil discharged from a mechanical oil pump into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrow part provided in a discharge passage in which hydraulic oil discharged from the mechanical oil pump flows becomes larger than a predetermined value. Air mixed into the hydraulic oil is compressed by increasing a line pressure as a differential rotation speed increases when oil temperature of the hydraulic oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or lower than a predetermined engine torque.