Patent US4432884A successfully refreshed from Google Patents.
US4432884A
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Scale inhibiting agent
Assignee: Katayama Chemical Inc
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Filing: 1982-07-19
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Granted: 1984-02-21
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Expires: 2002-07-19
Abstract
Abstract This invention relates to a scale inhibiting agent which comprises as an essential ingredient a copolymer of an alkylolamide compound such as N-methylol acrylamide, N-hydroxyethyl acrylamide or the like and an alkenyl compound such as acrylic acid, acrylamide, ethyl acrylate or the like.
Inventors
- 👤 Yoshinari Kawasaki
- 👤 Kenji Hanno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:23
CPC Classifications
C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
A scale inhibiting agent comprising as an active ingredient a copolymer of at least one of an alkylolamide compound having the general formula (I); ##STR3## wherein R 1 and R 2 independently represent a hydrogen atom or an alkyl group having one to three carbon atoms, and X is a bond or a straight or branched-chain alkylene group having one to eight carbon atoms, and at least one alkenyl compound having the general formula (II); ##STR4## wherein R 3 , R 4 and R 5 independently represent a hydrogen atom or a methyl group, and A is hydroxy group or an --OR 6 group in which R 6 is a lower alkyl group of one to four carbon atoms which may be substituted by a hydroxy group, an amino group or an --NHR 7 group in which R 7 is a lower alkyl group of one to four carbon atoms which may be substituted by --SO 3 H at the end carbon atom.
Claim 2
Dependent Claim
163 words
A scale inhibiting agent comprising as an active ingredient a copolymer of at least one of an alkylolamide compound having the general formula (I); ##STR3## wherein R 1 and R 2 independently represent a hydrogen atom or an alkyl group having one to three carbon atoms, and X is a bond or a straight or branched-chain alkylene group having one to eight carbon atoms, and at least one alkenyl compound having the general formula (II); ##STR4## wherein R 3 , R 4 and R 5 independently represent a hydrogen atom or a methyl group, and A is hydroxy group or an --OR 6 group in which R 6 is a lower alkyl group of one to four carbon atoms which may be substituted by a hydroxy group, an amino group or an --NHR 7 group in which R 7 is a lower alkyl group of one to four carbon atoms which may be substituted by --SO 3 H at the end carbon atom.
Claim 3
Dependent Claim
62 words
A scale inhibiting agent of claim 1 in which the alkylolamide compound of the general formula (I) is N-hydroxy acrylamide, N-hydroxy methacrylamide, N-methyl-N-hydroxyacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-methyl-N-methylol acrylamide, N-methyl-N-methylol methacrylamide, N-ethyl-N-methylol acrylamide, N-ethyl-N-methylol methacrylamide, N-hydroxyethyl acrylamide, N-hydroxyethyl methacrylamide, N-methyl-N-hydroxyethyl acrylamide, N-methyl-N-hydroxyethyl methacrylamide, N-methyl-N-hydroxyethyl methacrylamide, N-ethyl-N-hydroxyethyl acrylamide, N-ethyl-N-hydroxyethyl methacrylamide, N-propyl-N-hydroxyethyl acrylamide, N-propyl-N-hydroxyethyl methacrylamide, N-hydroxypropyl acrylamide, N-hydroxypropyl methacrylamide, N-hydroxyisopropyl acrylamide or N-hydroxyisopropyl methacrylamide.
Claim 4
Dependent Claim
22 words
A scale inhibiting agent of claim 1 in which the alkylolamide compound is N-methylol acrylamide, N-methylol methacrylamide, N-hydroxyethyl acrylamide or N-hydroxyethyl methacrylamide.
Claim 5
Dependent Claim
67 words
A scale inhibiting agent of claim 1 in which the alkenyl compound of the general formula (II) is acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, trans-2-methylcrotonic acid, 2-methyl-isocrotonic acid, acrylamide, methacrylamide, N-methyl acrylamide, N-ethyl acrylamide, N-propyl acrylamide, acrylamide-N-methyl-propan-sulfonic acid, methyl acrylate, methyl methacrylate, methyl crotonate, ethyl acrylate, ethyl methacrylate, ethyl crotonate, propyl acrylate, propyl methacrylate, propyl crotonate, butyl acrylate, butyl methacrylate, 2-hydroxyethyl acrylate or 2-hydroxypropyl methacrylate.
Claim 6
Dependent Claim
27 words
A scale inhibiting agent of claim 4 in which the alkenyl compound is acrylic acid, methacrylic acid, acrylamide, methacrylamide, acrylamide-N-methylpropan-sulfonic acid, methyl acrylate, ethylacrylate or hydroxyethyl acrylate.
Claim 7
Dependent Claim
37 words
A scale inhibiting agent of any of claims 1-5 in which the copolymer is obtained from the alkylolamide compound and the alkenyl compound which are present in a molar ratio of from about 1:9 to about 9:1.
Claim 8
Dependent Claim
26 words
A scale inhibiting agent of any claim 1-5 in which the copolymer has a molecular weight in the range of from about 500 to about 100,000.
Claim 9
Dependent Claim
26 words
A scale inhibiting agent of any claim 1-5 in which the copolymer has a molecular weight in the range of from about 500 to about 20,000.
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) | 1987-02-20 | 1987-08-22 | 1988-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-20 | 1991-08-22 | 1992-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-20 | 1995-08-22 | 1996-02-21 | $7700.00 | Window Closed / Lapsed |