US4405744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filler for paper, card or board, a process for its manufacture, and paper, card or board containing the filler
Assignee: Patheon Austria GmbH and Co KG
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Filing: 1981-05-20
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Granted: 1983-09-20
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Expires: 2001-05-20
Abstract
Abstract A filler for paper, card or board which has a good retention and consists of an inert core material and a hydrophilic coating, which consists of polyacrylamide having a molecular weight of 10 5 to 10 7 or of a mixture of this polyacrylamide with a urea-formaldehyde condensation resin. The filler is prepared by suspending the inert core material in an aqueous solution of a polyacrylamide having a molecular weight of 10 5 to 10 7 or in an aqueous solution of such a polyacrylamide and a urea-formaldehyde condensation resin, and drying this suspension by spray drying or in a stream of hot air. This crosslinks the initially water-soluble polymer and forms a coating, adhering to the core, which is insoluble in water but is hydrophilic and swells, and becomes tacky, in the presence of water.
Inventors
- 👤 Herbert Greinecker
- 👤 Gerhard Stern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:13
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/69; C; C09; C09C; C09C1/00; C09C1/40; C09C1/42; C09C3/00; C09C3/10; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
94 words
A filler for paper, card or board, which has a good retention comprising a substantially water insoluble, white and inorganic core material and a hydrophilic coating in an amount of 0.5 to 10% by weight, consisting of a polyacrylamide or its mixture with a urea-formaldehyde condensation resin, wherein the molar ratio of urea:formaldehyde is at least 1:1.2, said polyacrylamide having a molecular weight of 10 5 to 10 7 and having been made water-insoluble by crosslinking to an extent that it is able to swell and to become tacky in the presence of water.
Claim 2
Dependent Claim
94 words
A filler for paper, card or board, which has a good retention comprising a substantially water insoluble, white and inorganic core material and a hydrophilic coating in an amount of 0.5 to 10% by weight, consisting of a polyacrylamide or its mixture with a urea-formaldehyde condensation resin, wherein the molar ratio of urea:formaldehyde is at least 1:1.2, said polyacrylamide having a molecular weight of 10 5 to 10 7 and having been made water-insoluble by crosslinking to an extent that it is able to swell and to become tacky in the presence of water.
Claim 3
Dependent Claim
21 words
The filler according to claim 1, in which the inorganic white core material is clay, gypsum, titanium dioxide or calcium carbonate.
Claim 4
Dependent Claim
15 words
The filler according to claim 2, in which the inorganic white core material is clay.
Claim 5
Dependent Claim
16 words
The filler according to claim 1, in which the polyacrylamide is crosslinked by a urea-formaldehyde resin.
Claim 6
Dependent Claim
16 words
The filler according to claim 1, in which the polyacrylamide is crosslinked by formaldehyde or glyoxal.
Claim 7
Dependent Claim
21 words
The filler according to claim 1, in which the polyacrylamide has a molecular weight of 10 6 to 10 7 .
Claim 8
Dependent Claim
28 words
The filler according to claim 1, in which the sum of admixed urea-formaldehyde resin and crosslinking urea-formaldehyde resin is at most 85% by weight of the hydrophilic coating.
References Cited (Backward Citations)
US3190850A
Cited
US4128528A
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US4107126A
Cited
US4132562A
Cited
US4132561A
Cited
US4198471A
Cited
US4276212A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |