US3833467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modification of clay to improve electrostatic deposition
Assignee: Ransburg Corp
•
Filing: 1973-04-26
•
Granted: 1974-09-03
•
Expires: 1993-04-26
Abstract
Abstract Dry clay is electrostatically deposited on wet paper as it is formed on a Fourdrinier machine. This clay is coated with a cationic surface active agent and especially a dialkyl dimethyl ammonium chloride in order to minimize the formation of clay clusters which adhere to the electrostatic equipment and which drop off in the form of slugs to mar the paper. Pretreatment of the clay with a mild alkaline agent such as sodium carbonate causes the cationic agent to be more effective and the treatment to be more durable.
Inventors
- 👤 L Spiller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:06
CPC Classifications
C; C04; C04B; C04B33/00; C04B33/02; C04B33/13; C04B33/1305; D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/68; D21H19/00; D21H23/00; D21H23/02; D21H23/22; D21H23/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
19 words
A method as recited in claim 1 in which said quaternary ammonium chloride is a monoalkyl trimethyl ammonium chloride.
Claim 2
Dependent Claim
31 words
A method as recited in claim 1 in which said quaternary ammonium chloride is a dialkyl dimethyl ammonium chloride in which the alkyl groups are from 10-22 carbon atoms in length.
Claim 3
Dependent Claim
15 words
A method as recited in claim 3 in which said clay is in bead form.
Claim 4
Dependent Claim
32 words
A method as recited in claim 1 in which said sheet material is paper and the web moisture content at the point of clay deposition is at least 25 percent by weight.
References Cited (Backward Citations)
US2030483A
Cited
US2666699A
Cited
US2694633A
Cited
US2807543A
Cited
US3477904A
Cited
US3461032A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |