Patent US4759334A successfully refreshed from Google Patents.
Patent US4717758A successfully refreshed from Google Patents.
US4717758A
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US
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Papermaking additive
Assignee: Japan PMC Corp
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Filing: 1986-08-21
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Granted: 1988-01-05
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Expires: 2006-08-21
Abstract
Abstract A papermaking additive useful for papermaking in a neutral to alkaline pH region which comprises a water-soluble copolymer comprising (a) 1 to 20 mole % of dimethylaminopropyl (meth)acrylamide or its quaternized product, (b) 0.1 to 12 mole % of itaconic acid or its salt, and (c) 98.9 to 68 mole % of acrylamide, the (b)/(a) mole ratio being from 0.1 to 0.6.
Inventors
- 👤 Masatomi Ogawa
- 👤 Mayumi Narushima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:15
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/52; C08F220/54; C08F220/56; D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/41
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
63 words
A papermaking additive useful for papermaking in a neutral to alkaline pH region which comprises a water-soluble copolymer composed of (a) 1 to 20 mole % of dimethylaminopropyl (meth)acrylamide or its quaternized product, (b) 0.1 to 12 mole % of itaconic acid or its salt, and (c) 98.9 to 68 mole % of acrylamide, the (b)/(a) mole ratio being from 0.1 to 0.6.
Claim 2
Dependent Claim
63 words
A papermaking additive useful for papermaking in a neutral to alkaline pH region which comprises a water-soluble copolymer composed of (a) 1 to 20 mole % of dimethylaminopropyl (meth)acrylamide or its quaternized product, (b) 0.1 to 12 mole % of itaconic acid or its salt, and (c) 98.9 to 68 mole % of acrylamide, the (b)/(a) mole ratio being from 0.1 to 0.6.
Claim 3
Dependent Claim
51 words
The papermaking additive of claim 1 wherein the water-soluble copolymer is composed of 2 to 10 mole % of the component (a), 0.2 to 6 mole % of the component (b), and 97.8 to 84 mole % of the component (c), and the (b)/(a) mole ratio is from 0.1 to 0.6.
Claim 4
Dependent Claim
12 words
The papermaking additive of claim 2 wherein component (a) is dimethylaminopropyl acrylamide.
Claim 5
Dependent Claim
12 words
The papermaking additive of claim 2 wherein component (a) is dimethylaminopropyl methacrylamide.
Claim 6
Dependent Claim
16 words
The papermaking additive of claim 2 wherein component (a) is the quaternized product of dimethylaminopropyl (meth)acrylamide.
Claim 7
Dependent Claim
12 words
The papermaking additive of claim 1 wherein component (a) is dimethylaminopropyl acrylamide.
Claim 8
Dependent Claim
12 words
The papermaking additive of claim 1 wherein component (a) is dimethylaminopropyl methacrylamide.
Claim 9
Dependent Claim
16 words
The papermaking additive of claim 1 wherein component (a) is the quaternized product of dimethylaminopropyl (meth)acrylamide.
References Cited (Backward Citations)
US3043822A
Cited
US3776892A
Cited
US3957710A
Cited
US4271058A
Cited
US4218554A
Cited
US4314044A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |