Mitsubishi Chemical Corporation

Hitachi, Ltd.

Nicca Chemical Co., Ltd.

Hymo Corporation

Yasuharu Mori

Shin-ichi Sato

Akihiro Ishii

Kiyoji Kuma

Nobuhiko Ueno

Kouji Teramoto

Takahiro Oshida

Atsuo Takeuchi

Takashi Ono

Nobuo Kawamura

Hitoshi Nishimura

Satoshi Sakuma

Shigeru Sawayama

Toshiaki Hattori

Ryuichi Ansai

Juji Uchida

Toshimitsu Inoue

Kazunori Mukunoki

Masayuki Maeno

Kouji Midori

Shin Suwabe

Kohichi Satoh

Yukino Nagai

Fumi Oono

Fumiaki Satou

Noritsugu Ooishi

Provided are a method for recovering gold, in which gold is recovered from a solution containing a gold cyano complex using a crosslinked resin containing a vinyl amine unit, by which gold can be efficiently recovered from the solution not only in a case (A) where a concentration of the gold cyano complex in the solution is low but also in a case (B) where another metal is dissolved in the solution; a method for recovering gold, in which the crosslinked resin and the solution are brought into contact with each other to separate the crosslinked resin and the solution from each other, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B); and a gold recovery facility comprising: a container inside which the crosslinked resin is accommodated in a flowable manner; and a device which feeds the solution to the container, by which gold can be efficiently recovered from the solution not only in the case (A) but also in the case (B).

Method for recovering gold and gold recovery facility

Provided is a polymer flocculant which is capable of controlling the structure of a polymer that is a copolymerization product of a monomer (a) having a structure derived from formula (I) in each molecule and a water-soluble unsaturated monomer (b) having a polymerizable unsaturated bond in each molecule, and which has a branched or cross-linking structure, and is excellent in water-solubility and water dispersibility,  In formula (I), Rand Rare respectively a linear or branched functional group configured of atoms selected from the group consisting of carbon not having a carbon-carbon unsaturated bond, oxygen, nitrogen, and hydrogen; W is a non-metal element of the group 15; X and Y are each a linear or branched functional group configured of atoms selected from the group consisting of carbon, oxygen, nitrogen, and hydrogen, and each have at least one carbon-carbon unsaturated bond, provided that X and Y have different structures; and Z is a chlorine ion, a bromine ion, or an iodine ion.

Polymer, method for producing polymer and polymer flocculant

Provided are a method for producing N-(&#x3b1;-alkoxyethyl)formamide, comprising adding an acid catalyst to the mixed liquid within 3 hours from start of mixing after mixing of N-(&#x3b1;-hydroxyethyl)formamide with an alcohol has been started, by which the N-(&#x3b1;-alkoxyethyl)formamide can be produced at a high yield without additional investment in plant and equipment while suppressing an increase in the temperature of the mixed liquid and preventing corrosion of a pipe; and a method for producing N-(&#x3b1;-alkoxyethyl)formamide, comprising degassing carbon dioxide in the reaction of N-(&#x3b1;-hydroxyethyl)formamide with an alcohol, by which the N-(&#x3b1;-alkoxyethyl)formamide having a decreased carbonate concentration can be produced.

Method for producing N-(alpha-alkoxyethyl)formamide

A method for producing N-vinylformamide through a vapor-phase thermal decomposition reaction using an evaporator () for evaporating a raw material, a thermal decomposition reactor () for thermally decomposing a raw material gas generated by the evaporator () and a condenser () for condensing a thermally decomposed gas generated by the thermal decomposition reactor (), wherein the evaporation of the raw material is started in the evaporator () while the temperature of a tube wall of a first connection tube () that connects the evaporator () to the thermal decomposition reactor () satisfies a requirement represented by formula (1): (temperature of tube wall (&#xb0; C.))&#x2265;0.37&#xd7;(pressure of evaporator (mmHg))+205.

Method for producing N-vinylformamide

The present invention relates to a method for producing a vinylamine unit-containing polymer, the method comprising: preparing a mixture for polymerization (a) containing N-vinylformamide as a monomer component by using crude N-vinylformamide which contains the N-vinylformamide and formamide and has a content of the formamide of 1 part by mass or more with respect to 100 parts by mass of the N-vinylformamide; obtaining a polymerization product (b) containing an N-vinylformamide unit-containing polymer and formamide by polymerizing the monomer component in the mixture for polymerization (a); and obtaining a hydrolysis product (c) containing a vinylamine unit-containing polymer through a hydrolysis treatment of the polymerization product (b) using an acid or a base.

Method for producing vinylamine unit-containing polymer and polymerization product

Provided is a method for efficiently producing on an industrial scale a high-performance polyvinylamine solution having good handling properties. After producing a polymer containing N-vinylcarboxamide monomer units having a value of the weight average molecular weight (Mw)/number average molecular weight (Mn) of 5 or higher by aqueous solution standing adiabatic polymerization, the polymer is hydrolyzed in an aqueous solvent in the presence of an alkali and an antigelling agent. In a preferred embodiment of the present invention, a polymer powder having a volatile content of 0.1-12% by mass is obtained by drying and pulverizing after producing a (co)polymer, and the powder obtained is stored or transported to the site of use of the polymer solution and hydrolyzed in an aqueous solvent in the presence of an alkali and an antigelling agent when the polymer solution is needed or at the site of use of the polymer solution.

Method for producing vinyl amine unit-containing polymer solution

A process for the preparation of an aqueous solution or dispersion containing a cationic polymer, which comprises the steps of: polymerizing a monomer including an N-vinyl-carboxylic acid amide represented by the general formula CH &boxH;CHNHCOR, wherein R represents a hydrogen atom or methyl group, in an aqueous medium in the presence of either or both of a polyethylene glycol and polypropylene glycol; and then modifying the resulting polymer with an acid or base. Furthermore, an aqueous composition containing a cationic polymer, which comprises (A) a modified N-vinylcarboxylic acid amide polymer, (B) either or both of a polyethylene glycol and polypropylene glycol, and (C) water is disclosed.

Process for the preparation of aqueous solution or dispersion containing cationic polymer

Disclosed is a process for producing a powdered water-soluble polymer comprising hydrolyzing a copolymer comprising an N-vinylamide unit and a vinyl acetate unit while dispersed in water under a basic condition and then washing the resulting powdered water-soluble polymer with at least one washing liquid selected from an alcohol, water at 20&deg; C. or lower, and salt water.

Process for producing vinylamine-vinyl alcohol copolymer and use of the copolymer

A process for the preparation of an aqueous solution or dispersion containing a cationic polymer, which comprises the steps of: polymerizing a monomer including an N-vinylcarboxylic acid amide represented by the general formula CH.sub.2 .dbd.CHNHCOR, wherein R represents a hydrogen atom or methyl group, in an aqueous medium in the presence of either or both of a polyethylene glycol and polypropylene glycol; and then modifying the resulting polymer with an acid or base. Furthermore, an aqueous composition containing a cationic polymer, which comprises (A) a modified N-vinylcarboxylic acid amide polymer, (B) either or both of a polyethylene glycol and polypropylene glycol, and (C) water is disclosed.

Process for the preparation of aqueous solution or dispersion containing

A database managing system for effecting management in accessing data stored in a database via an index is so configured so as to prevent duplication of index key values and increase of index key values from degrading the access performance and lowering the storage efficiency of the index. Upon receiving, from an application program, a request to add a data record, a database manager adds this data record to a data portion and effects addition and update of an index record in an index portion. An index manager intervenes in this processing and excepts, from the index portion, an index record containing an index key value which has reached an upper limit value of the number of duplications preset in an exception key managing table. At the time of recreation of the index, the index manager refers to access time contained in index records and excepts index records which have not been accessed during an elapse of a fixed period of time.

Index managing method in database managing system

A method of fixing cellulose fibers dyed with a reactive dye, which comprises a homopolymer containing a vinylamine structural unit, a copolymer containing from 5 to 90% by weight of a vinylamine structural unit and from 5 to 90% by weight of a diallylamine structural unit, a copolymer containing from 5 to 90% by weight of a vinylamine structural unit, from 5 to 90% by weight of structural unit of a vinyl compound copolymerizable with the vinylamine, or copolymer containing from 5 to 90% by weight of a vinylamine structural unit, from 5 to 90% weight of a diallylamine structural unit and from 5 to 90% by weight of a structural unit of a vinyl compound copolymerizable with vinylamine and diallylamine, and/or a salt of the homopolymer or copolymers.

Method of fixing cellulose fibers dyed with a reactive dye

An improved process for producing N-vinylformamide including the steps of evaporating N-(.alpha.-substituted-ethyl)formamide or ethylidenebisformamide under reduced pressure and thermally decomposing the vapor at 150.degree.-600.degree. C., wherein the improvement comprises performing thermal decomposition by means of a pyrolysis reactor which is made up of two stages, the first being an unpacked tubular reactor constructed such that liquid flows down and the second being a packed tubular reactor, while keeping the vapor temperature at 200.degree.-400.degree. C. at the outlet of the unpacked tubular reactor and the inside temperature of the packed tubular reactor at 200.degree.-600.degree. C.

Production of N-vinylformamide

There is provided a lactam ring-containing polymer comprising: 20 to 100 molar % of a structural unit represented by the general formula (1); 0 to 70 molar % of a structural unit represented by the general formula (2); and 0 to 70 molar % of a structural unit represented by the general formula (3) and/or a structural unit represented by the general formula (4): ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 each represents a hydrogen atom or a methyl group, and X represents COOR.sup.4 and/or CONR.sup.5 R.sup.6 in which R.sup.4, R.sup.5 and R.sup.6 each represents a hydrogen atom or a C1-C4 alkyl. The polymer is excellent in heat resistance and is expected to be used for resin modifiers, polymeric additives for petroleum tertiary recovery, and other various applications.

Growing community of inventors

Tokyo, Japan

Yasuharu Mori