US4264412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of recovering fibres
Assignee: Wiggins Teape Group Ltd
•
Filing: 1979-05-22
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Granted: 1981-04-28
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Expires: 1999-05-22
Abstract
Abstract Fibre recovery process for pressure-sensitive carbonless copying paper which comprises defibrating the wastage in aqueous media, preferably in the presence of a cationic quaternary ammonium surface active agent, treating the wastage with acid to destroy the microcapsules, and bleaching the defibrated wastage with a bleaching agent.
Inventors
- 👤 David J. Hasler
- 👤 Peter Sinclair
- 👤 Eileen H. Burns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:45
CPC Classifications
D; D21; D21C; D21C5/00; D21C5/02; B; B41; B41M; B41M5/00; B41M5/124; B41M5/1246; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/64
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
64 words
A process for the recovery of fibers from wastage of pressure-sensitive carbonless copying paper having color former containing microcapsules, comprising the steps of: defibrating the wastage in aqueous media; treating the wastage in the aqueous media with acid to destroy the microcapsules, the acid reducing the pH of the aqueous media to less than 3.0; and, bleaching the defibrated wastage with a bleaching agent.
Claim 2
Dependent Claim
64 words
A process for the recovery of fibers from wastage of pressure-sensitive carbonless copying paper having color former containing microcapsules, comprising the steps of: defibrating the wastage in aqueous media; treating the wastage in the aqueous media with acid to destroy the microcapsules, the acid reducing the pH of the aqueous media to less than 3.0; and, bleaching the defibrated wastage with a bleaching agent.
Claim 3
Dependent Claim
27 words
A process according to claim 1 and including the step of including a cationic quaternary ammonium surface active agent in said aqueous media during said defibrating step.
Claim 4
Dependent Claim
55 words
A process according to claim 2 wherein said surface active agent is a compound of formula (1), ##STR2## wherein R 1 is a C 1 -C 4 alkyl group, R 2 is a C 5 -C 18 alkyl or alkenyl group, R is R 1 or R 2 , and X - is an anion.
Claim 5
Dependent Claim
19 words
A process according to claim 3, wherein R 2 is a C 8 -C 18 alkyl or alkenyl group.
Claim 6
Dependent Claim
19 words
A process according to either claim 3 or 4, wherein R 1 and R 2 are straight chain groups.
Claim 7
Dependent Claim
11 words
A process according to claim 5, wherein R 1 is methyl.
Claim 8
Dependent Claim
17 words
A process according to claim 5, wherein R 2 is octyl, decyl, dodecyl, tetradecyl, hexadecyl or octadecyl.
Claim 9
Dependent Claim
11 words
A process according to claim 5, wherein R 2 is octadecenyl.
Claim 10
Dependent Claim
20 words
A process according to claim 3, wherein the surface active agent consists of a mixture of compounds of formula (1).
Claim 11
Dependent Claim
13 words
A process according to claim 3, wherein the anion is a chloride anion.
Claim 12
Dependent Claim
17 words
A process according to claim 2, wherein from 0.5 to 10% of surface active agent is used.
Claim 13
Dependent Claim
21 words
A process according to claim 1, wherein the acid is sulphuric acid, hydrochloric acid, nitric acid, acetic acid or citric acid.
Claim 14
Dependent Claim
20 words
A process according to claim 1, wherein the acid reduces the pH of the aqueous media to less than 2.5.
Claim 15
Dependent Claim
21 words
A process according to claim 1, wherein the acid reduces the pH of the aqueous media to from 1 to 2.
Claim 16
Dependent Claim
19 words
A process according to claim 1, wherein said acid treating step is carried out subsequently to said defibrating step.
Claim 17
Dependent Claim
23 words
A process according to claim 15, and including the step of rinsing the wastage between said defibrating step and said acid treating step.
Claim 18
Dependent Claim
16 words
A process according to claim 1, wherein the bleaching agent is chlorinated water or hydrogen peroxide.
Claim 19
Dependent Claim
14 words
A process according to claim 1, wherein the bleaching agent is sodium hypochorite solution.
Claim 20
Dependent Claim
41 words
A process according to claim 18, wherein the acid treating step produces a colored solution and the bleaching step comprises adding the sodium hypochlorite solution directly to the defibrated wastage once the colored solution has been produced without adjusting the pH.
Claim 21
Dependent Claim
27 words
A process according to claim 1, wherein the pressure-sensitive carbonless copying paper contains gelatin or aminoplast microcapsules and a color developing coating of a clay or resin.
References Cited (Backward Citations)
US3933578A
Cited
GB1422489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |