摘要:
The present invention relates to the 3,4-Dicarboalkoxybiphenyl-3′,4′-dicarboxylic acid (including the corresponding acid anhydride) represented by the general formula (1): wherein R11 and R12 each represents an alkyl group having 1 to 4 carbon atoms, and n represents the number of waters of hydration that is 0 or 1.
摘要:
Disclosed is a method for producing a biphenyltetracarboxylic acid ester by oxidative coupling a phthalic acid ester by using a catalyst comprising at least a palladium salt, a copper salt and a β-dicarbonyl compound in the presence of a molecular oxygen, wherein the β-dicarbonyl compound is supplied into a reaction mixture liquid intermittently at an interval of less than 30 minutes, or continuously. This method allows, in particular, the selective and economical production of an asymmetric biphenyltetracarboxylic acid tetraester such as 2,3,3′,4′-biphenyltetracarboxylic acid tetraester.
摘要:
A backpack strap includes a strap main body, an upper end of which is connected to a backpack frame, a pad attached to the strap main body on a user side, and a contact state holding unit holding an upper end of the pad in contact with the backpack frame. Upper portions of the strap main body and pad are spaced apart from each other by a specified distance. The upper end of the pad has a shape and a strength that is, when contacting the backpack frame, able to prevent the backpack strap from falling sideways. Due to a tensile force of the upper portion of the strap main body and a stiffness of the upper portion of the pad, the upper portion of the pad is held in a projecting state with the upper end of the pad acting as a support point.
摘要:
Disclosed is a method for producing a biphenyltetracarboxylic acid ester by oxidative coupling a phthalic acid ester by using a catalyst comprising at least a palladium salt, a copper salt and a β-dicarbonyl compound in the presence of a molecular oxygen, wherein the β-dicarbonyl compound is supplied into a reaction mixture liquid intermittently at an interval of less than 30 minutes, or continuously. This method allows, in particular, the selective and economical production of an asymmetric biphenyltetracarboxylic acid tetraester such as 2,3,3′,4′-biphenyltetracarboxylic acid tetraester.
摘要:
There is provided a pipe joint structure wherein a proximal insert portion (20a) of an attachment pipe (20) is inserted into and secured to a base pipe (12). This pipe joint structure comprises: a cylindrical rotational operating member (30) rotatably and externally fitted on the base pipe; and a pin-shaped projection (25) which is radially protruded from the proximal insert portion of the attachment pipe; wherein the rotational operating member is provided, on an inner circumferential surface thereof, with a spiral pulling/pushing groove (35) enabling the pin-shaped projection to be introduced therein through a cut-out portion (16) formed at a distal portion (12a) of the base pipe, thereby enabling the attachment pipe to be pulled into the base pipe through the displacement of the pin-shaped projection along the groove as the rotational operating member is rotated in one direction and enabling the attachment pipe to be pushed out of the base pipe through the displacement of the pin-shaped projection along the groove as the rotational operating member is rotated in the opposite direction.
摘要:
The present invention relates to the 3,4-Dicarboalkoxybiphenyl-3′,4′-dicarboxylic acid (including the corresponding acid anhydride) represented by the general formula (1): wherein R11 and R12 each represents an alkyl group having 1 to 4 carbon atoms, and n represents the number of waters of hydration that is 0 or 1.