US3948976A
Expired / Lapsed
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Partial esters of hydroxy polycarboxylic acids
Assignee: Wyeth Holdings LLC
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Filing: 1974-03-29
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Granted: 1976-04-06
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Expires: 1994-03-29
Abstract
Abstract Partial esters of hydroxy-polycarboxylic acids having at least one unesterified carboxyl group and at least one other carboxyl group esterified with an alcohol having one to 20 repeating oxyalkylene groups and a terminal hydrocarbon radical are useful as additives for inhibiting corrosion and scale on metal parts in a circulating water system. Especially suitable for the use are alkyl polyoxyethylene alcohol partial esters of citric, malic and tartaric acids. Preparation and use of several preferred partial esters of the class are detailed.
Inventors
- 👤 Tzeng Jiueq Suen
- 👤 Arthur James Begala, Jr.
- 👤 Martin Grayson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:11
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C08; C08G; C08G65/00; C08G65/02; C08G65/32; C08G65/329; C08G65/331; C08G65/332; C23F11/12; C23F11/122; C23F11/128; C23F11/16; C23F11/163; C23F11/167; C23F11/1676
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
67 words
A partial ester of a hydroxy lower alkyl polycarboxylic acid having at least one unesterified carboxylate radical in the molecule and having at least one other carboxyl group of the molecule esterified with an alcohol having the formula ##EQU3## wherein m is an integer from 1 to 20 Z is hydrogen or methyl and R is alkyl, alkenyl, cycloalkyl or aralkyl having 8 to 20 carbon atoms.
Claim 2
Dependent Claim
67 words
A partial ester of a hydroxy lower alkyl polycarboxylic acid having at least one unesterified carboxylate radical in the molecule and having at least one other carboxyl group of the molecule esterified with an alcohol having the formula ##EQU3## wherein m is an integer from 1 to 20 Z is hydrogen or methyl and R is alkyl, alkenyl, cycloalkyl or aralkyl having 8 to 20 carbon atoms.
Claim 3
Dependent Claim
49 words
A partial ester defined by claim 1 wherein the hydroxy-polycarboxylic acid is malic acid and one carboxyl group of the acid is esterified with an alcohol of the defined formula wherein m is an integer from 2 to 5 and R is alkyl having 8 to 20 carbon atoms.
Claim 4
Dependent Claim
49 words
A partial ester defined by claim 1 wherein the hydroxy-polycarboxylic acid is tartaric acid and one carboxyl group of the acid is esterified with an alcohol of the defined formula wherein m is an integer from 2 to 5 and R is alkyl having 8 to 20 carbon atoms.
Claim 5
Dependent Claim
14 words
A partial ester defined by claim 2 wherein the value of m is 3.
Claim 6
Dependent Claim
14 words
A partial ester defined by claim 3 wherein the value of m is 3.
Claim 7
Dependent Claim
15 words
A partial ester defined by claim 2 wherein R is alkyl having 10-14 carbon atoms.
Claim 8
Dependent Claim
15 words
A partial ester defined by claim 4 wherein R is alkyl having 10-14 carbon atoms.
Claim 9
Dependent Claim
15 words
A partial ester defined by claim 3 wherein R is alkyl having 10-14 carbon atoms.
Claim 10
Dependent Claim
15 words
A partial ester defined by claim 5 wherein R is alkyl having 10-14 carbon atoms.
Claim 11
Dependent Claim
15 words
A partial ester defined by claim 2 wherein R is alkyl having 12-14 carbon atoms.
Claim 12
Dependent Claim
15 words
A partial ester defined by claim 4 wherein R is alkyl having 12-14 carbon atoms.
Claim 13
Dependent Claim
14 words
A partial ester defined by claim 1 wherein the hydroxy-polycarboxylic acid is citric acid.
Claim 14
Dependent Claim
18 words
A partial ester defined by claim 12 wherein the defined partial ester is a monoester of citric acid.
Claim 15
Dependent Claim
18 words
A partial ester defined by claim 12 wherein the defined partial ester is a diester of citric acid.
Claim 16
Dependent Claim
15 words
A partial ester defined by claim 12 wherein the value of m is about three.
Claim 17
Dependent Claim
17 words
A partial ester defined by claim 15 wherein R is alkyl having 10 to 14 carbon atoms.
Claim 18
Dependent Claim
14 words
A partial ester defined by claim 13 wherein the value of m is 3.
Claim 19
Dependent Claim
14 words
A partial ester defined by claim 14 wherein the value of m is 3.
Claim 20
Dependent Claim
15 words
A partial ester defined by claim 17 wherein R is alkyl having 10-14 carbon atoms.
Claim 21
Dependent Claim
15 words
A partial ester defined by claim 18 wherein R is alkyl having 10-14 carbon atoms.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |