US4382008A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Corrosion inhibitors and compositions containing them
Assignee: Imperial Chemical Industries Ltd
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Filing: 1981-02-20
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Granted: 1983-05-03
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Expires: 2001-02-20
Abstract
Abstract Corrosion inhibitors for aqueous media comprise a triazole, an alkali metal borate, benzoate, and silicate and an alkali metal salt of a C 7 to C 13 dibasic acid. They may be used in antifreeze compositions for motor vehicles. Since neither nitrites and amines are required the danger of forming toxic nitrosamines by the reaction of these materials is overcome.
Inventors
- 👤 William Boreland
- 👤 John M. Dossor
- 👤 Geoffrey S. Jaques
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:13
CPC Classifications
C; C23; C23F; C23F11/00; C23F11/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
128 words
A corrosion inhibitor which comprises: from 2 to 50 parts by weight of a triazole, an alkali metal borate in an amount sufficient to give a boron content of 5 to 60 parts by weight, from 100 to 500 parts by weight of an alkali metal benzoate or toluate, an alkali metal silicate sufficient to provide water soluble silicate and present in an amount of 1.5 to 15 parts by weight expressed as SiO 2 , and from 15 to 250 parts by weight, calculated as the free acid, of an alkali metal salt of a C 7 to C 13 dibasic organic acid, the corrosion inhibitor giving at a temperature of 25° C. in a 2% solution in water a pH in the range 6.5 to 10.
Claim 2
Dependent Claim
128 words
A corrosion inhibitor which comprises: from 2 to 50 parts by weight of a triazole, an alkali metal borate in an amount sufficient to give a boron content of 5 to 60 parts by weight, from 100 to 500 parts by weight of an alkali metal benzoate or toluate, an alkali metal silicate sufficient to provide water soluble silicate and present in an amount of 1.5 to 15 parts by weight expressed as SiO 2 , and from 15 to 250 parts by weight, calculated as the free acid, of an alkali metal salt of a C 7 to C 13 dibasic organic acid, the corrosion inhibitor giving at a temperature of 25° C. in a 2% solution in water a pH in the range 6.5 to 10.
Claim 3
Dependent Claim
16 words
A composition as claimed in claim 1 in which the alkali metal is sodium and/or potassium.
Claim 4
Dependent Claim
25 words
A composition as claimed in claim 1 in which the dibasic acid has 9 to 12 carbon atoms and the triazole is benzotriazole or tolyltriazole.
Claim 5
Dependent Claim
31 words
A composition as claimed in claim 1 in which the alkali metal silicate is a metasilicate, an alkali metal benzoate is present and the alkali metal borate is a sodium tetraborate.
Claim 6
Dependent Claim
22 words
An antifreeze composition which comprises a corrosion inhibitor as claimed in claim 1 and 10,000 parts by weight of the antifreeze component.
Claim 7
Dependent Claim
15 words
A composition as claimed in claim 5 in which the antifreeze component is ethylene glycol.
Claim 8
Dependent Claim
32 words
A heat exchange fluid which comprises an antifreeze composition as claimed in claim 5 or 6 and 0.5 to 5 parts by volume of water per part by volume of antifreeze composition.
Claim 9
Dependent Claim
19 words
A heat exchange system comprising a heat exchange liquid which comprises a corrosion inhibitor as claimed in claim 1.
Claim 10
Dependent Claim
33 words
A composition as claimed in claim 1, 2, 3 or 4 wherein the alkali metal benzoate is present in an amount to give a boron content of 10 to 30 parts by weight.
Claim 11
Dependent Claim
31 words
A composition as claimed in claim 1, 2, 3 or 4 wherein the alkali metal benzoate or toluate is present in an amount of from 150 to 300 parts by weight.
Claim 12
Dependent Claim
44 words
A composition as claimed in claim 1, 2, 3 or 4 wherein the alkali metal salt of the C 7 to C 13 dibasic organic acid is present in an amount of from 20 to 150 parts by weight, calculated as the free acid.
Claim 13
Dependent Claim
17 words
A composition as claimed in claim 1 or 3 wherein the dibasic organic acid is sebacic acid.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-02 | 1986-11-01 | 1987-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-02 | 1990-11-01 | 1991-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-02 | 1994-11-01 | 1995-05-03 | $7700.00 | Window Closed / Lapsed |