Abstract: Provided is a method for producing a polyacrylic acid (salt)-based water absorbent resin in which the physical properties (especially liquid permeability) are improved and maintained even in large scale production. The method for producing a polyacrylic acid (salt)-based water absorbent resin, which sequentially includes a polymerization step, in which a monomer aqueous solution having acrylic acid (salt) as a main component is polymerized, a drying step, in which a water-containing gel-like crosslinked polymer obtained in the polymerization step is dried, and a classification step, in which a polymer obtained in the drying step is classified, wherein a rocking-type sieve classification apparatus is used in the classification step, and the rocking-type sieve classification apparatus has a sieve net having a trajectory and a rotation speed in the following ranges; radial gradient R: from 5 to 40 mm, tangential gradient T: from 0.

Abstract: A method for producing a water absorbent resin, the method including a polymerization step, a drying step, a classification step, and a surface crosslinking step. The classification step carried out before or after the surface crosslinking step requires use of a tapping material and a metal sieve mesh, in which the tapping material being heated at 40° C. to 100° C. is installed below the metal sieve mesh, and the metal sieve mesh has an area of 1 to 10 m2/sheet. The classification step further requires introducing a classification aid particle, which has a specific gravity different from that of the water absorbent resin, to the metal sieve mesh; and monitoring the presence or absence of damage to the metal sieve mesh.

Abstract: The present invention provides a method for producing, by adding an additive and/or gas bubbles to a monomer with high efficiency, a polyacrylic acid (salt)-based water-absorbing resin having high physical properties while high productivity is maintained. The step of preparing an aqueous monomer solution includes the steps of: preparing an aqueous solution; and adding a water-insoluble additive and/or gas bubbles. A retention time from when the water-insoluble additive and/or the gas bubbles is/are added to when polymerization starts is 1 second to 60 seconds.

Abstract: The purpose of the present invention is to provide a method for producing a water absorbent resin in which a water absorbent resin having excellent properties can be obtained effectively.

Abstract: A method for producing polyacrylic acid (salt)-based water-absorbing resin includes a step of polymerizing an acrylic acid (salt)-based aqueous monomer solution, the polymerization step involving use of a polymerization reaction apparatus including a polymerization reaction unit covered with a casing, the polymerization step involving a polymerization reaction under internal pressure of the polymerization reaction unit, the internal pressure being slightly reduced and having a pressure reduction level of more than 0 kPa and not more than 10 kPa relative to the ambient pressure at the periphery of the polymerization reaction unit.

Abstract: An object of the present invention is to provide a simple method for improving and stabilizing the physical properties (for example, liquid permeability) of a water absorbent resin, without requiring investment in expensive facilities or modification of raw materials. In particular, the object is to provide a method which is useful in the large-scale production of a water absorbent resin.

Abstract: The present invention relates to a power module obtained by connecting the opposite sides of a chip with solder, and prevents the side surfaces of a base portion from becoming wet with solder, which would otherwise cause connection failures of the solder or chip displacement, and also prevents peeling of molding resin, which would otherwise break the chip or shorten the life of the solder. The base portion is integrally formed with one of lead frames, and the side surfaces of the base portion and the surface of the main body of the lead frame are roughened so as to have reduced solder wettability. Meanwhile, the solder connection surface of the base portion is not roughened so as to ensure the solder wettability. Accordingly, it is possible to reduce failures that may occur during solder connection and obtain a highly reliable power module (FIG. 5).

Abstract: The physical properties of a water-absorbing resin with low residual monomer content are improved or stabilized, without sacrifices in productivity, production cost, stability, etc. Provided is a water-absorbing resin with low residual monomer content and excellent whiteness, wherein a water-absorbing resin consumed in large quantities in disposable diapers, etc., is preferably a sustainable and renewable water-absorbing resin that does not require excessive purification of the acrylic acid, particularly acrylic acids derived from non-fossil sources, that is the starting material of the water-absorbing resin. Disclosed is a method of manufacturing a hydrophilic polyacrylic acid (salt) resin, which is a method of manufacturing a water-absorbing polyacrylic acid resin that comprises a step in which a monomer is prepared from acrylic acid, a step in which said monomer is polymerized, and a step in which the resulting hydrous gel is dried.

Abstract: To suppress a temperature rise of a chip accompanying a production of large output by a power converter, and to reduce a size of the power converter. A power semiconductor device includes: a first power semiconductor element to configure an upper arm of an inverter circuit; a second power semiconductor element to configure a lower arm of the inverter circuit; a first lead frame to transmit power to the first power semiconductor element; a second lead frame to transmit power to the second power semiconductor element; a first gate lead frame to transmit a control signal to the first power semiconductor element; and a sealing member to seal the first power semiconductor element, the second power semiconductor element, the first lead frame, the second lead frame, and the first gate lead frame. In the power semiconductor device, a through-hole is formed in the sealing member, and a part of the first gate lead frame and a part of the second lead frame are exposed to an inner peripheral surface of the through-hole.

Abstract: A method for producing a water absorbent resin, the method including a polymerization step, a drying step, a classification step, and a surface crosslinking step. The classification step carried out before or after the surface crosslinking step requires use of a metal sieve mesh having stretch tension from 35 to 100 N/cm, in which an air jet cleaner or an air jet brush cleaner and plural tapping balls or tapping blocks are installed below the metal sieve mesh, a classification aid particle having specific gravity different from that of the water absorbent resin powder is added, and a fine powder of the water absorbent resin and the classification aid particle are removed.

Abstract: Size reduction of a power conversion device is intended. A power conversion device according to the present invention includes: a first power semiconductor module; a second semiconductor module; and a fixing member which fixes the first power semiconductor module, wherein the first power semiconductor module has a first power semiconductor device, a first case which houses the first power semiconductor device, and a first flange portion connected to the case, the second power semiconductor module has a second power semiconductor device, and a second case which houses the second power semiconductor device, the second case is connected to the first flange portion so as to provide a first flow path space for allowing a coolant to flow between the second case and the first case, and the first flange portion is fixed to the fixing member while supporting the first case and the second power semiconductor module.

Abstract: In a method for producing a water absorbent resin by drying a particulate hydrogel having a high solid content concentration (of 45% by weight or more, preferably 50% by weight or more, and more preferably 55% by weight or more), a method for efficient drying water absorbent resin having maintained/improved physical properties is provided.

Abstract: A power module includes a semiconductor device having at least one electrode surface on each side thereof, a first conductive member connected to the electrode surface provided on one side of the semiconductor device with solder, and a second conductive member connected to the electrode surface provided on the other side of the semiconductor device with solder, with at least one of the electrode surfaces provided on the one side of the semiconductor device being double comb-shaped.

Abstract: A power converter includes a power module allowing supply and cutoff of main current, a driver module controlling supply and cutoff of the main current, a high potential side semiconductor device, and a low potential side semiconductor device. Plural power module side wirings are connected with respective electrodes contained in the high and low potential side semiconductor devices. Plural driver module side wirings are provided on the driver module as wirings connected with the plural corresponding power module side wirings. Conductors are disposed in the vicinity of a plane on which the plural power module side wirings are provided and a plane on which the plural driver module side wirings are provided, and electrically connected to surround magnetic flux generated by current looping at least through a power source transformer, the driver module side wirings, and the power module side wirings.

Abstract: A power semiconductor device includes a plurality of power semiconductor elements constituting upper and lower arms of an inverter circuit, a first sealing member sealing the plurality of power semiconductor elements, a positive electrode-side terminal and a negative electrode-side terminal each connected with any of the plurality of power semiconductor elements and protruding from the first sealing member, a second sealing member sealing at least a part of the positive electrode-side terminal and at least a part of the negative electrode-side terminal, and a case in which the power semiconductor elements sealed with the first sealing member are housed.

Abstract: An object of the present invention is to provide a simple method for improving and stabilizing the physical properties (for example, liquid permeability) of a water absorbent resin, without requiring investment in expensive facilities or modification of raw materials. In particular, the object is to provide a method which is useful in the large-scale production of a water absorbent resin.

Abstract: A power semiconductor device includes a plurality of power semiconductor elements constituting upper and lower arms of an inverter circuit, a first sealing member sealing the plurality of power semiconductor elements, a positive electrode-side terminal and a negative electrode-side terminal each connected with any of the plurality of power semiconductor elements and protruding from the first sealing member, a second sealing member sealing at least a part of the positive electrode-side terminal and at least a part of the negative electrode-side terminal, and a case in which the power semiconductor elements sealed with the first sealing member are housed.

Abstract: A production of a water-absorbent resin by which a particle diameter of the water-absorbent resin can be controlled simply and conveniently, and a content of fine powder can be decreased, without necessity of change of raw materials or expensive facility investment is to be provided. The method is a continuous production method of a polyacrylic acid (salt)-based water-absorbent resin, comprising a polymerization step of an aqueous solution containing acrylic acid (salt), a drying step of the resultant hydrogel-like polymer, a pulverization step of the dried substance, a classification step of the pulverized substance, and optionally a surface cross-linking step of the classified substance, wherein (a) the drying step and the pulverization step are connected via a storage step and a transportation step; and (b) a time of holding the dried substance from a time of completing the drying step to a time of starting the pulverization step is set at 3 minutes or longer.

Abstract: The present invention relates to a power module obtained by connecting the opposite sides of a chip with solder, and prevents the side surfaces of a base portion from becoming wet with solder, which would otherwise cause connection failures of the solder or chip displacement, and also prevents peeling of molding resin, which would otherwise break the chip or shorten the life of the solder. The base portion is integrally formed with one of lead frames, and the side surfaces of the base portion and the surface of the main body of the lead frame are roughened so as to have reduced solder wettability. Meanwhile, the solder connection surface of the base portion is not roughened so as to ensure the solder wettability. Accordingly, it is possible to reduce failures that may occur during solder connection and obtain a highly reliable power module.

Abstract: Provided is a method for producing a polyacrylic acid (salt)-based water absorbent resin in which the physical properties (especially liquid permeability) are improved and maintained even in large scale production. The method for producing a polyacrylic acid (salt)-based water absorbent resin, which sequentially includes a polymerization step, in which a monomer aqueous solution having acrylic acid (salt) as a main component is polymerized, a drying step, in which a water-containing gel-like crosslinked polymer obtained in the polymerization step is dried, and a classification step, in which a polymer obtained in the drying step is classified, wherein a rocking-type sieve classification apparatus is used in the classification step, and the rocking-type sieve classification apparatus has a sieve net having a trajectory and a rotation speed in the following ranges; radial gradient R: from 5 to 40 mm, tangential gradient T: from 0.