Abstract: A process for producing carboxylic acid anhydrides by the carbonylation reaction of a carboxylic acid ester, derived from an alcohol and a carboxylic acid, with carbon monoxide containing a small amount of hydrogen in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, the carboxylic acid anhydride, the carboxylic acid, and at least one ionic liquid consisting of a cation and an anion where the cation of the ionic liquid has a nitrogen-containing heterocyclic structure. The ionic liquid has at least one of the following structural forms: The reaction rate of the carbonylation reaction is increased by the use of the specified ionic liquid promoters.

Abstract: A process for producing carboxylic acid anhydrides by the carbonylation reaction of a carboxylic acid ester, derived from an alcohol and a carboxylic acid, with carbon monoxide containing a small amount of hydrogen in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, the carboxylic acid anhydride, the carboxylic acid, and at least one ionic liquid consisting of a cation and an anion where the cation of the ionic liquid has a nitrogen-containing heterocyclic structure. The ionic liquid has at least one of the following structural forms: The reaction rate of the carbonylation reaction is increased by the use of the specified ionic liquid promoters.

Abstract: The present invention relates to a process for producing carboxylic acid anhydrides, in which a carboxylic acid ester, derived from an alcohol and a carboxylic acid, and carbon monoxide containing a small amount of hydrogen are used as raw materials and subjected to a carbonylation reaction in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, at least one organic promoter, the carboxylic acid anhydride and the carboxylic acid, wherein the organic promoter is selected from at least one of the following structural forms (I), (II) and (III). According to the process of the present invention, the reaction rate of the carbonylation reaction is increased by the use of the specified organic promoters.

Abstract: The present invention relates to a process for producing carboxylic acid anhydrides, in which a carboxylic acid ester, derived from an alcohol and a carboxylic acid, and carbon monoxide containing a small amount of hydrogen are used as raw materials and subjected to a carbonylation reaction in a liquid reaction medium in the presence of a Group VIII B catalyst to produce a carboxylic acid anhydride. The reaction medium comprises the Group VIII B catalyst, an organic halide, the carboxylic acid ester, an alkali metal salt, at least one organic promoter, the carboxylic acid anhydride and the carboxylic acid, wherein the organic promoter is selected from at least one of the following structural forms (I), (II) and (III). According to the process of the present invention, the reaction rate of the carbonylation reaction is increased by the use of the specified organic promoters.

Abstract: An electrical connector which includes a seat integrally made of plastic and formed with a plurality of through holes, a plurality of metal terminals each fitted in a respective one of the through holes of the seat and provided with a tail, and a base board used as a conductive medium between an electrical connector and a printed circuit board to provide a closed circuit, wherein the base board has an upper surface in contact with the electrical connector, a lower surface in contact with the printed circuit board, and a plurality of conductive members arranged between the upper and lower surfaces, whereby the possibility of unstable connection between the terminal and the solder ball can be eliminated.

Abstract: A universal serial bus connector includes a main body and at least one indicator. The main body is formed from an insulator material, and has a plug inserting side and a board mounting side. The plug inserting side is formed with at least one plug slot that has a set of conductive contact terminals mounted therein. The contact terminals have solder tails that extend through the board mounting side. The indicator is mounted on the main body, and has power terminals separate from the contact terminals. When the contact terminals and the power terminals are mounted on a circuit board, the indicator can be controlled via the power terminals to indicate the status of signal transmission through the contact terminals.

Abstract: A cable assembly has a flat cable, and a plurality of connectors connected to the flat cable. Each connector includes a plurality of signal terminals, at least one grounding piece and an insulating body. A specific grounding device is formed on a specific position of the grounding piece. The spacing wall of the grounding piece slot and the signal terminal slot of the insulating body with respect to the base of the grounding piece is hollowed so that when the grounding piece is inserted into the grounding piece slot, the specific grounding device passes through the hollow portion to directly contact at least one specific signal terminal in the adjacent signal terminal slot. The signal transferred by the at least one specific signal terminal will ground without passing through the specific conductive wire of the bank wire.

Abstract: An electric connector has a long insulating housing with a plurality of conducting terminals arranged within the housing. Installing seats are formed on two distal ends of the housing for mounting latch structures. Each latch structure includes a twistable head with a twistable device provided on the transverse opposite side surfaces of the twistable head, by which the user may horizontally pull the latch structure outwards in the longitudinal direction to rotate the latch from a locking position to a releasing position.

Abstract: An electrical connector includes a generally U-shaped connector housing, which has two parallel side walls. Each of the side walls is formed with an integral projection, which engages a notch in a circuit board that is inserted into the connector. Two unitary reinforcing members are secured to the side walls, respectively. Each of the unitary reinforcing members has an elongated abutment plate overlying a respective one of the side walls to reinforce the side walls, two contact portions and a stop element, which is located between the contact portions. When inserted into or disengaged from the connector, the circuit board slides over the projections of the side walls, thereby permitting flexing of the side walls and movement of the stop element relative to the contact portions. Upon contact of the stop element with either of the contact portions, the side walls cannot continue to flex. Accordingly, excessive flexure and breakage of the side walls can be prevented.