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Patent US4174430A successfully refreshed from Google Patents.
US4174430A
Expired / Lapsed
US
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Process for producing porous polystyrene gel
Assignee: Tosoh Corp
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Filing: 1978-07-24
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Granted: 1979-11-13
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Expires: 1998-07-24
Abstract
Abstract A porous polystyrene gel is produced by a suspension polymerization in an aqueous system under an incorporation of more than 5 mole % of a radical polymerization catalyst to a total amount of styrene and divinyl benzene with an inert organic solvent.
Inventors
- 👤 Shiro Kido
- 👤 Tetsuo Yokota
- 👤 Yasuhiro Nakahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:38
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08J9/286; B; B01; B01J; B01J20/00; B01J20/22; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; C08J2325/00; Y; Y10; Y10S; Y10S521/00; Y10S521/921
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
61 words
A process for producing a porous polystyrene gel of improved gel permeation chromatographic properties which comprises polymerizing styrene and divinylbenzene with an inert organic solvent in an aqueous suspension polymerization, in the presence of a radical polymerization catalyst, wherein said catalyst is present in an amount of more than 5 mole % of the total amount of styrene and divinyl benzene.
Claim 2
Dependent Claim
61 words
A process for producing a porous polystyrene gel of improved gel permeation chromatographic properties which comprises polymerizing styrene and divinylbenzene with an inert organic solvent in an aqueous suspension polymerization, in the presence of a radical polymerization catalyst, wherein said catalyst is present in an amount of more than 5 mole % of the total amount of styrene and divinyl benzene.
Claim 3
Dependent Claim
15 words
A process according to claim 1 wherein the radical polymerization catalyst is an organic peroxide.
Claim 4
Dependent Claim
20 words
A process according to claim 2 wherein the organic peroxide is benzoyl peroxide, lauryl peroxide, diisopropyl peroxydicarbonate or t-butyl peroxypivalate.
Claim 5
Dependent Claim
15 words
A process according to claim 1 wherein the radical polymerization catalyst is an azo compound.
Claim 6
Dependent Claim
15 words
A process according to claim 4 wherein the azo compound is azo-bis-isobutyronitrile or 2,2'-azo-bis(2,4-dimethyl valeronitrile).
Claim 7
Dependent Claim
51 words
A process according to claim 1 wherein said inert organic solvent is selected from the group consisting of toluene, benzene, ethylacetate, butylacetate, nonane, dodecane, n-amyl alcohol, isoamyl alcohol, nitromethane and nitroethane and wherein the incorporated amount of said inert organic solvent depends upon the desired porosity of the porous polystyrene gel.
Claim 8
Dependent Claim
21 words
The process of claim 1 wherein said aqueous suspension polymerization is carried out at a temperature of 50° to 120° C.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein said temperature is 60° to 90° C.
Claim 10
Dependent Claim
31 words
The process of claim 1 wherein said organic solvent is used in an amount of from 50 to 250% by weight based on the total amount of styrene and divinyl benzene.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein said organic solvent is present in an amount of from 100 to 200 weight %.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-12 | 1983-05-14 | 1983-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-12 | 1987-05-14 | 1987-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-12 | 1991-05-14 | 1991-11-13 | $7700.00 | Window Closed / Lapsed |