Abstract: The method for producing a vapor composition containing lactic acid of the present invention is capable of suppressing the generation of by-products such as acetaldehyde and carbon monoxide due to pyrolysis of a lactic acid species during vaporization. Furthermore, a lactic acid oligomer generated can be effectively used without loss, and a vapor composition containing lactic acid can be industrially efficiently produced stably for a long time. The present invention relates to a method for producing a vapor composition containing lactic acid including: feeding a liquid composition containing lactic acid to a vaporizer; mixing the liquid composition with a liquid composition containing a lactic acid oligomer contained in the vaporizer to prepare a liquid mixture; and heating the liquid mixture to vaporize part of the liquid mixture, whereby a vapor composition containing lactic acid is produced.

Abstract: The method for producing a vapor composition containing lactic acid of the present invention is capable of suppressing the generation of by-products such as acetaldehyde and carbon monoxide due to pyrolysis of a lactic acid species during vaporization. Furthermore, a lactic acid oligomer generated can be effectively used without loss, and a vapor composition containing lactic acid can be industrially efficiently produced stably for a long time. The present invention relates to a method for producing a vapor composition containing lactic acid including: feeding a liquid composition containing lactic acid to a vaporizer; mixing the liquid composition with a liquid composition containing a lactic acid oligomer contained in the vaporizer to prepare a liquid mixture; and heating the liquid mixture to vaporize part of the liquid mixture, whereby a vapor composition containing lactic acid is produced.

Abstract: The present invention provides a method for producing (meth)acrylic acid, which achieves enhanced productivity or a reduced amount of a catalyst in production of (meth)acrylic acid from 3-hydroxycarboxylic acid, and enables stable production of (meth)acrylic acid at low cost. The method is a method for producing (meth)acrylic acid using 3-hydroxycarboxylic acid as a starting material, the method including a polymerization step of polymerizing 3-hydroxycarboxylic acid to generate a composition containing a 3-hydroxycarboxylic acid polymer, and a step of generating (meth)acrylic acid from the composition containing the 3-hydroxycarboxylic acid polymer, the 3-hydroxycarboxylic acid polymer obtained in the polymerization step including trimer or higher order units, the trimer or higher order units constituting 3% by mass or more of a total of 100% by mass of the 3-hydroxycarboxylic acid and the 3-hydroxycarboxylic acid polymer.

Abstract: The present invention provides a method for producing (meth)acrylic acid, which achieves enhanced productivity or a reduced amount of a catalyst in production of (meth)acrylic acid from 3-hydroxycarboxylic acid, and enables stable production of (meth)acrylic acid at low cost. The method is a method for producing (meth)acrylic acid using 3-hydroxycarboxylic acid as a starting material, the method including a polymerization step of polymerizing 3-hydroxycarboxylic acid to generate a composition containing a 3-hydroxycarboxylic acid polymer, and a step of generating (meth)acrylic acid from the composition containing the 3-hydroxycarboxylic acid polymer, the 3-hydroxycarboxylic acid polymer obtained in the polymerization step including trimer or higher order units, the trimer or higher order units constituting 3% by mass or more of a total of 100% by mass of the 3-hydroxycarboxylic acid and the 3-hydroxycarboxylic acid polymer.

Abstract: A method for producing acrylic acid and/or an ester thereof from a raw material composition containing hydroxypropionic acid and/or an ester thereof, the method including the steps of: (a) evaporating the raw material composition; and (b) dehydrating the evaporated raw material composition by contact with a dehydration catalyst, wherein the total amount of hydroxypropionic acid and/or an ester thereof supplied in the step (b) is controlled to be 70% by mass or more based on 100% by mass of the total amount of hydroxypropionic acid and/or an ester thereof supplied in the step (a).

Abstract: The present invention aims to provide a method for stably producing highly pure acrylic acid and/or an ester thereof for a long time, in which a blockage in an evaporator or reactor and lowering of the catalytic activity are suppressed. The present invention also aims to provide a method for producing a hydrophilic resin with excellent performance and high safety using acrylic acid and/or an ester thereof containing fewer impurities as a raw material.

Abstract: A radiation detection element comprises an insulating base frame having a pair of leg portions with a spacing left therebetween, a pair of electroconductive members each disposed on one surface of the corresponding leg portions of the base frame, an electrode plate disposed on the rear surface of the base plate to cover the spacing between the leg portions, and a plurality of signal electrode wires spanned between the electroconductive members such that they confront the electrode plate, in which an insulating member is disposed between the base frame and the electroconductive member and/or between the base frame and the electrode plate such that its longitudinal edge portion is overhung into the spacing of the base frame.