US4618375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent iron oxide pigments
Assignee: BASF Corp
•
Filing: 1984-10-04
•
Granted: 1986-10-21
•
Expires: 2004-10-04
Abstract
Abstract The present invention relates to a process for preparing transparent iron oxide pigments comprising reacting an iron compound, an ammonia releasing compound and water in a non-aqueous solvent in which both the iron compound and the ammonia-releasing compound have appreciable solubility. The reaction is performed by refluxing this composition. Where a red pigment is desired, a high boiling alcohol may be employed whereby the refluxing is carried out above 200° C. which thus converts the pigment to a red iron oxide pigment during the reflux step. In order to get a metallic finish, aluminum flake pigment may be added to a mixture of the iron compound and solvent prior to addition of the ammonia-releasing salt.
Inventors
- 👤 Arvind S. Patil
- 👤 Louis J. Pepoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:40
CPC Classifications
C; C01; C01G; C01G49/00; C01G49/02; C01G49/06; C09; C09C; C09C1/00; C09C1/0015; C09C1/22; C09C1/24; C01P; C01P2006/00; C01P2006/60; C09C2200/00; C09C2200/10; C09C2200/1054; C09C2220/00; C09C2220/10
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
55 words
A process for preparing transparent iron oxide pigment comprising reacting an iron compound, an organic ammonia releasing compound and water in a non-aqueous solvent in which both the iron compound and ammonia releasing compound have appreciable solubility, and in which water has some solubility by refluxing for a period of about 1 to 24 hours.
Claim 2
Dependent Claim
55 words
A process for preparing transparent iron oxide pigment comprising reacting an iron compound, an organic ammonia releasing compound and water in a non-aqueous solvent in which both the iron compound and ammonia releasing compound have appreciable solubility, and in which water has some solubility by refluxing for a period of about 1 to 24 hours.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said refluxing is followed by washing with non-aqueous solvent, filtration and drying.
Claim 4
Dependent Claim
48 words
The process of claim 2 wherein the amount of iron compound is about 1 to 50 percent, the amount of said ammonia releasing compound is about 1 to 20 percent, the amount of water is about 0 to 5 percent, all based on the weight of the solvent.
Claim 5
Dependent Claim
20 words
The process of claim 3 wherein said iron compound is a ferrous compound and said ammonia releasing compound is urea.
Claim 6
Dependent Claim
12 words
The process of claim 4 wherein said iron compound is ferrous chloride.
Claim 7
Dependent Claim
18 words
The process of claim 4 wherein the mole ratio of released ammonia to ferrous ion is about 2:1.
Claim 8
Dependent Claim
20 words
The process of claim 3 wherein said iron compound is a ferric compound and said ammonia releasing compound is urea.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein said iron compound is ferric sulfate.
Claim 10
Dependent Claim
17 words
The process of claim 7 wherein the mole ratio of released ammonia to ferric ion is 3:1.
Claim 11
Dependent Claim
21 words
The process of claim 3 wherein said solvent is ethanol and the reflux temperature is from about 60° to 80° C.
Claim 12
Dependent Claim
37 words
The process of claim 1 wherein said solvent is a high boiling alcohol, the reflux step is carried out at a temperature of at least about 200° C. and the product produced is a red iron oxide.
Claim 13
Dependent Claim
18 words
The process of claim 11 wherein said refluxing is followed by washing with non-aqueous solvent, filtration and drying.
Claim 14
Dependent Claim
48 words
The process of claim 12 wherein the amount of iron compound is about 1 to 50 percent, the amount of said ammonia releasing compound is about 1 to 20 percent, the amount of water is about 0 to 5 percent, all based on the weight of the solvent.
Claim 15
Dependent Claim
19 words
The process of claim 13 wherein said iron compound is ferrous chloride and said ammonia releasing compound is urea.
Claim 16
Dependent Claim
22 words
The process of claim 14 wherein said solvent is decyl alcohol and the reflux temperature is from about 180° to 230° C.
Claim 17
Dependent Claim
22 words
The process of claim 1 wherein aluminum flake pigment is added to the solvent before the addition of the ammonia releasing salt.
Claim 18
Dependent Claim
18 words
The process of claim 16 wherein said refluxing is followed by washing with non-aqueous solvent, filtration and drying.
Claim 19
Dependent Claim
48 words
The process of claim 17 wherein the amount of iron compound is about 1 to 50 percent, the amount of said ammonia releasing compound is about 1 to 20 percent, the amount of water is about 0 to 5 percent, all based on the weight of the solvent.
Claim 20
Dependent Claim
19 words
The process of claim 18 wherein said iron salt is ferrous chloride and said ammonia releasing salt is urea.
Claim 21
Dependent Claim
10 words
The process of claim 18 wherein said solvent is ethanol.
Claim 22
Dependent Claim
47 words
The process of claim 1 wherein said solvent is a high boiling alcohol and said reflux step is carried out at a temperature of at least 200° C. and where aluminum flake pigment is added to said solvent prior to the addition of the ammonia releasing compound.
Claim 23
Dependent Claim
18 words
The process of claim 21 wherein said refluxing is followed by washing with said solvent, filtration and drying.
Claim 24
Dependent Claim
48 words
The process of claim 22 wherein the amount of iron compound is about 1 to 50 percent, the amount of said ammonia releasing compound is about 1 to 20 percent, the amount of water is about 0 to 5 percent, all based on the weight of the solvent.
Claim 25
Dependent Claim
19 words
The process of claim 23 wherein said iron compound is ferrous chloride and said ammonia releasing compound is urea.
Claim 26
Dependent Claim
22 words
The process of claim 23 wherein said solvent is decyl alcohol and the reflux temperature is from about 180° to 230° C.
References Cited (Backward Citations)
US4414033A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-20 | 1990-04-21 | 1990-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-20 | 1994-04-21 | 1994-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-20 | 1998-04-21 | 1998-10-21 | $7700.00 | Window Closed / Lapsed |