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1. (WO2001005877) AQUEOUS POLYVINYL ALCOHOL GEL, PROCESS FOR PRODUCING THE SAME, AND WASTEWATER TREATMENT APPARATUS
Latest bibliographic data on file with the International Bureau   

Pub. No.: WO/2001/005877 International Application No.: PCT/JP2000/004647
Publication Date: 25.01.2001 International Filing Date: 12.07.2000
Chapter 2 Demand Filed: 08.02.2001
IPC:
C02F 3/10 (2006.01) ,C08F 8/00 (2006.01) ,C08F 16/06 (2006.01) ,C08J 3/075 (2006.01)
C CHEMISTRY; METALLURGY
02
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
F
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
3
Biological treatment of water, waste water, or sewage
02
Aerobic processes
10
Packings; Fillings; Grids
C CHEMISTRY; METALLURGY
08
ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
F
MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
8
Chemical modification by after-treatment
C CHEMISTRY; METALLURGY
08
ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
F
MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
16
Homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an alcohol, ether, aldehydo, ketonic, acetal, or ketal radical
02
by an alcohol radical
04
Acyclic compounds
06
Polyvinyl alcohol
C CHEMISTRY; METALLURGY
08
ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
J
WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H142
3
Processes of treating or compounding macromolecular substances
02
Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
03
in aqueous media
075
Macromolecular gels
Applicants:
FUJII, Hiroaki [JP/JP]; JP (UsOnly)
NANBA, Michiyuki [JP/JP]; JP (UsOnly)
ABE, Masanobu [JP/JP]; JP (UsOnly)
KITAMURA, Takanori [JP/JP]; JP (UsOnly)
KURARAY CO., LTD. [JP/JP]; 1621, Sakazu Kurashiki-shi Okayama 710-8622, JP (AllExceptUS)
Inventors:
FUJII, Hiroaki; JP
NANBA, Michiyuki; JP
ABE, Masanobu; JP
KITAMURA, Takanori; JP
Priority Data:
11/20118215.07.1999JP
Title (EN) AQUEOUS POLYVINYL ALCOHOL GEL, PROCESS FOR PRODUCING THE SAME, AND WASTEWATER TREATMENT APPARATUS
(FR) GEL AQUEUX D'ALCOOL POLYVINYLIQUE, SON PROCEDE DE FABRICATION ET INSTALLATION DE TRAITEMENT DES EAUX USEES
Abstract:
(EN) An aqueous PVA gel having a structure comprising an outer layer having fine crevasse-like pores on the surface and an inner layer comprising a dense three-dimensional network structure. The aqueous gel can be produced by mixing a polymer solution containing a vinyl alcohol polymer having a degree of polymerization of 3,000 or higher and a polymer which gels upon contact with a cation with a substance capable of causing the polymer solution to undergo phase separation to thereby prepare a liquid having separated phases, contacting the phase-separated liquid with a cation-containing fluid to solidify at least the polymer constituting the surface of the phase-separated liquid, subsequently contacting the resultant solid with a gellant liquid for the vinyl alcohol polymer to cause it to gel, and conducting acetalization simultaneously with and/or after the gelation in such a manner that the acetalization is continued for a time sufficient to obtain a degree of acetalization of 50% or higher. The gel has excellent durability and can hence be advantageously used in wastewater treatment apparatuses operated under severe conditions, e.g., with vigorous agitation.
(FR) Cette invention concerne un alcool polyvinylique dont la structure comprend un couche extérieure présentant en surface de petits pores semblables à des crevasses et une couche intérieure constituée par une structure dense en réseau tridimensionnel. Le gel aqueux peut s'obtenir de la manière suivante : mélange d'une part d'une solution polymère renfermant un polymère d'alcool vinylique au degré de polymérisation de 3000 ou plus et un polymère se gélifiant au contact d'un cation, d'autre part d'une substance capable de provoquer une séparation de phase de la solution polymère, ce qui donne un liquide à phases distinctes ; mise en contact du liquide à phases distinctes avec un liquide renfermant des cations de manière à solidifier au moins le polymère qui constitue la surface dudit liquide à séparation de phases ; mise en contact ultérieure du solide ainsi obtenu avec un liquide gélifiant qui amène la transformation du polymère d'alcool polyvinylique en gel ; et acétalisation en même temps que la gélification ou après cette dernière de telle sorte que le processus d'acétalisation se poursuive pendant un laps de temps suffisant pour produire un degré d'acétalisation d'au moins 50 %. Le gel ainsi obtenu possède une remarquable longévité et convient bien pour les installations de traitement des eaux usées fonctionnant en conditions dures, c'est-à-dire avec un brassage vigoureux.
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Designated States: CN, KR, US
European Patent Office (EPO) (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE)
Publication Language: Japanese (JA)
Filing Language: Japanese (JA)