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Patent US4101437A successfully refreshed from Google Patents.
US4101437A
Expired / Lapsed
US
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Inhibitor for aqueous acid solutions
Assignee: Henkel Corp
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Filing: 1977-03-29
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Granted: 1978-07-18
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Expires: 1997-03-29
Abstract
Abstract Disclosed is a composition and process for inhibiting an aqueous acid solution and a composition so inhibited. The acid solution containing, for example, HF is inhibited by including a condensation product of a mixture of diethyl- and dibutyl-thiourea with hexamethylenetetramine.
Inventors
- 👤 Josef Rones
- 👤 Joachim Geldner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:11
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/04; C23G1/06; C23G1/065
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
50 words
An inhibitor for an aqueous acid solution consisting essentially of the condensation product of a mixture of diethyl- and dibutyl-thiourea with hexamethylenetetramine wherein the weight ratio of diethyl- to dibutyl-thiourea is from 1:5 to 5:1 and wherein the mole ratio of hexamethylenetetramine to thiourea mixture is from 0.1 to 1.1.
Claim 2
Dependent Claim
50 words
An inhibitor for an aqueous acid solution consisting essentially of the condensation product of a mixture of diethyl- and dibutyl-thiourea with hexamethylenetetramine wherein the weight ratio of diethyl- to dibutyl-thiourea is from 1:5 to 5:1 and wherein the mole ratio of hexamethylenetetramine to thiourea mixture is from 0.1 to 1.1.
Claim 3
Dependent Claim
18 words
The inhibitor of claim 1 wherein the condensation is performed at temperatures of from 100° to 150° C.
Claim 4
Dependent Claim
27 words
The inhibitor of claim 1 comprising from 10 to 30 wt. % of the condensation product of claim 1 in 40 to 96 wt. % sulfuric acid.
Claim 5
Dependent Claim
38 words
The inhibitor of claim 1 further including as a reactant a third organic thiourea derivative containing organic radicals of up to 10 carbon atoms in an amount of up to 20 wt. % of the diethyl- dibutyl-thiourea mixture.
Claim 6
Dependent Claim
31 words
An inhibited aqueous acidic solution comprising the product of claim 1 and at least one acid selected from the group consisting of hydrofluoric, hydrochloric, sulphuric, amidosulphonic, citric, tartaric and oxalic acids.
Claim 7
Dependent Claim
21 words
A process for inhibiting the attack of an aqueous acid solution comprising adding to the solution the product of claim 1.
References Cited (Backward Citations)
US2485529A
Cited
US3074825A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |