US4306955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photopolymerized acrylic polymer essentially devoid of residual monomer(s)
Assignee: Rhone Poulenc Industries SA
•
Filing: 1980-04-04
•
Granted: 1981-12-22
•
Expires: 2000-04-04
Abstract
Abstract The thin rubbery layer resulting from the photopolymerization of a thin layer of an aqueous solution of acrylic monomer(s) is face surface coated with a coating of an alkali metal sulfite and/or metabisulfite, and is then shredded, dried and ground to provide acrylic polymer/copolymer from which virtually all residual monomer has been depleted and which is well suited for use as a polymeric flocculant.
Inventors
- 👤 Jean Neel
- 👤 Jean Boutin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:58
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/46; C08F2/48
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
129 words
A process for the removal of residual monomer from the thin, adhesive, rubbery layer resulting from the photopolymerization of a thin layer of an aqueous solution of acrylic monomer selected from the group consisting of acrylamide, acrylic acid and methacrylic acid and the salts and esters thereof, aminoalkylacrylate and aminoalkylmethacrylate and quaternaries thereof, acrylonitrile, hydroxyalkylacrylate and hydroxylalkylmethacrylate, and mixtures thereof, comprising coating at least one face surface of such thin rubbery, adhesive layer with a powder comprising at least one member selected from the group consisting of an alkali metal sulfite and an alkali metal bisulfite, comminuting said coated, thin rubbery, adhesive layer so as to admix inner and outer portions of said layer, extruding said comminuted and admixed layer to form particulates, and drying and grinding the particulates.
Claim 2
Dependent Claim
129 words
A process for the removal of residual monomer from the thin, adhesive, rubbery layer resulting from the photopolymerization of a thin layer of an aqueous solution of acrylic monomer selected from the group consisting of acrylamide, acrylic acid and methacrylic acid and the salts and esters thereof, aminoalkylacrylate and aminoalkylmethacrylate and quaternaries thereof, acrylonitrile, hydroxyalkylacrylate and hydroxylalkylmethacrylate, and mixtures thereof, comprising coating at least one face surface of such thin rubbery, adhesive layer with a powder comprising at least one member selected from the group consisting of an alkali metal sulfite and an alkali metal bisulfite, comminuting said coated, thin rubbery, adhesive layer so as to admix inner and outer portions of said layer, extruding said comminuted and admixed layer to form particulates, and drying and grinding the particulates.
Claim 3
Dependent Claim
22 words
The process as defined in claim 1, said ground particulates having a content in residual monomer of less than 0.05% by weight.
Claim 4
Dependent Claim
18 words
The process as defined by claim 1, said powder having a grain size of less than 0.1 mm.
Claim 5
Dependent Claim
26 words
The process as defined by claims 1, said coating comprising from about 0.1% to 3% by weight of the total weight of said thin rubbery layer.
Claim 6
Dependent Claim
26 words
The process as defined by claim 4, said coating comprising from about 0.3% to 2% by weight of the total weight of said thin rubbery layer.
Claim 7
Dependent Claim
20 words
The process as defined by claim 4, said at least one member being sodium sulfite, sodium bisulfite, or admixtures thereof.
Claim 8
Dependent Claim
27 words
The process as defined by claim 4, said coating further comprising a member selected from the group consisting of an alkali metal carbonate and an ammonium carbonate.
Claim 9
Dependent Claim
18 words
The process as defined by claim 7, said coating comprising up to 60% by weight of said carbonate.
Claim 10
Dependent Claim
12 words
The process as defined by claim 8, said carbonate being sodium carbonate.
Claim 11
Dependent Claim
12 words
The process as defined by claim 8, said carbonate being ammonium carbonate.
Claim 12
Dependent Claim
18 words
The process as defined by claim 7, said aqueous solution photopolymerized having a pH of less than 12.
Claim 13
Dependent Claim
18 words
The process as defined by claim 1, said aqueous solution photopolymerized having a pH of greater than 12.
Claim 14
Dependent Claim
21 words
The process as defined by claim 1, said aqueous solution photopolymerized having a thickness of from about 2 to 20 mm.
Claim 15
Dependent Claim
18 words
The process as defined by claim 1, said aqueous solution photopolymerized comprising a catalyzing amount of a photoinitiator.
Claim 16
Dependent Claim
11 words
The process as defined by claim 1, said monomer being acrylamide.
Claim 17
Dependent Claim
17 words
The process as defined by claim 1, both face surfaces of said thin rubbery layer being coated.
Claim 18
Dependent Claim
27 words
The process as defined in claim 1, wherein the concentration of said acrylic monomer in said aqueous solution ranges between about 40 to 60 percent by 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) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |