Patent US4634599A successfully refreshed from Google Patents.
EP0303440A2
Expired / Lapsed
EP
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Method for production of water absorbent resin
Assignee: Nippon Shokubai Co Ltd
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Filing: 1988-08-09
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Granted: —
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Expires: 2008-08-09
Abstract
Abstract The present invention is a method for the production of a water absorbent resin, which comprises preparing a monomer component having an ability to form a cross-linked structure, having an acid group-containing monomer content of at least 50 mol%, and having 10 to 50mol% of the acid group-containing monomer neutralised. This is subjected to aqueous solution polymerisation to form a hydrated gel polymer within a reaction vessel having a plurality of rotary shafts each fitted with stirring blades.
Inventors
- 👤 Kazumasa Kimura
- 👤 Takumi Hatsuda
- 👤 Yoshio Irie
- 👤 Tadao Shimomura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 03:45
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/04; C08F2/10; B; B01; B01J; B01J20/00; B01J20/22; B01J20/26; C08F20/00; C08F20/02; C08F20/04; Y; Y10; Y10S; Y10S526/00; Y10S526/93
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
76 words
A method for the production of a water absorbent resin, characterised by preparing a monomer component having an ability to form a cross-linked structure having an acid group-containing monomer content of at least 50 mol%, and having 10 to 50 mol% of the acid group-containing monomer neutralised and subjecting the monomer component to aqueous solution polymerisation to form a hydrated gel polymer within reaction vessel having a plurality of rotary shafts each fitted with stirring blades.
Claim 2
Independent Claim
76 words
A method for the production of a water absorbent resin, characterised by preparing a monomer component having an ability to form a cross-linked structure having an acid group-containing monomer content of at least 50 mol%, and having 10 to 50 mol% of the acid group-containing monomer neutralised and subjecting the monomer component to aqueous solution polymerisation to form a hydrated gel polymer within reaction vessel having a plurality of rotary shafts each fitted with stirring blades.
Claim 3
Dependent Claim
22 words
A method as claimed in Claim 1, characterised in that the acid group-containing monomer has 10 to 40 mol % thereof neutralised.
Claim 4
Dependent Claim
52 words
A method as claimed in Claim 1 or Claim 2 characterised in that the polymerisation is carried out while the hydrated get polymer formed during the course of the polymerisation is finely divided by the shearing force generated by the rotation of a plurality of rotary shafts each fitted with stirring blades.
Claim 5
Dependent Claim
25 words
A method as claimed in Claim 3 characterised in that the recton vessel provided with the plurality of rotary shafts is a twin-arm type breaker.
Claim 6
Independent Claim
22 words
A method as claimed in any preceding claim characterised in that monomer contains a carboxylic acid group and/or a sulphonic acid group.
Claim 7
Dependent Claim
26 words
A method as claimed in Claim 5 characterised in that the acid group-containing monomer is (meth)acrylic acid, a 2-acrylamide-1-methyl propane-sulphonic acid, and/or a 2-(meth)acryloyl ethanesulphonic acid.
Claim 8
Dependent Claim
17 words
A method as claimed in Claim 5, characterised in that the acid group-containing monomer is acrylic acid.
Claim 9
Independent Claim
26 words
A method as claimed in any preceding claim characterised in that the monomer content has a concentration in the range of 5 to 50% by weight.
Claim 10
Independent Claim
38 words
A method as claimed in any preceding claim characterised in that the monomer component contains 0.001 to 5 mol% based on the monomer component, of a cross-linking monomer possessing at least two polymerising double bonds in its molecule.
Claim 11
Independent Claim
46 words
A method as claimed in any preceding claim, characterised by adding at least one neutralising agent comprising a basic substance or a salt of a weak acid, to the hydrated gel polymer thereby adjusting the ratio of neutralisation of the polymer to at least 50 mol%.
Claim 12
Dependent Claim
17 words
A method as claimed in Claim 10 characterised in that the basic substance is an alkali hydroxide.
Claim 13
Dependent Claim
24 words
A method as claimed in Claim 10 characterised in that the salt of a weak acid is a strong alkali salt of carbonic acid.
Claim 14
Independent Claim
49 words
A method as claimed in any of Claims 10 to 12 characterised in that the neutralisation of the acid group of the hydrated gel polymer is effected within the reaction vessel by virtue of the shearing force generated by the stirring blades in the presence of the neutralising agent.
Claim 15
Dependent Claim
25 words
A method as claimed in Claim 13 characterised in that the reaction vessel provided with the pluraity of rotary shafts is a twin-arm type kneader.
References Cited (Backward Citations)
No citation records indexed.
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