US3928057A
Expired / Lapsed
US
⏱️ 0.0 years remaining
TiO{HD 2 {B Pigment coated with porous alumina/silica and dense silica
Assignee: EIDP Inc
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Filing: 1974-05-30
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Granted: 1975-12-23
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Expires: 1994-05-30
Abstract
Abstract A coated titanium dioxide pigment, and the process for its preparation, consisting essentially of a core of pigmentary titanium dioxide (TiO2), a porous inner coating of at least one hydrous oxide selected from the group consisting of silica (SiO2) and alumina (Al2O3), said silica being present in an amount less than 12% by weight, based on the uncoated pigment, and said alumina being present in an amount less than 11% by weight, based on the uncoated pigment, and a dense outer coating of silica in an amount between about 2% and about 17% by weight, based on the uncoated pigment. Optionally the coated pigment can have an additional coating of porous Al2O3, up to 5%. As a component of coating compositions, this pigment provides a high degree of hiding power and durability.
Inventors
- 👤 Raymond Lew Decolibus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:53
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/36; C09C1/3607; C09C1/3653; C09C1/3661; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
90 words
COATED TIO2 PIGMENT CONSISTING ESSENTIALLY OF A CORE OF PIGMENTARY TIO2, A POROUS INNER COATING OF SILICA AND ALUMINA SAID SILICA, CALCULATED AS SIO2, BEING PRESENT IN AN AMOUNT LESS THAN ABOUT 12% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2, AND SAID ALUMINA, CALCULATED AS AL2O3, BEING PRESENT IN AN AMOUNT LESS THAN ABOUT 11% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2, AND A DENSE OUTER COATING OF SILICA IN AN AMOUNT CALCULATED AS SIO2, BETWEEN ABOUT 2% BY WEIGHT AND ABOUT 17% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2.
Claim 2
Dependent Claim
90 words
COATED TIO2 PIGMENT CONSISTING ESSENTIALLY OF A CORE OF PIGMENTARY TIO2, A POROUS INNER COATING OF SILICA AND ALUMINA SAID SILICA, CALCULATED AS SIO2, BEING PRESENT IN AN AMOUNT LESS THAN ABOUT 12% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2, AND SAID ALUMINA, CALCULATED AS AL2O3, BEING PRESENT IN AN AMOUNT LESS THAN ABOUT 11% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2, AND A DENSE OUTER COATING OF SILICA IN AN AMOUNT CALCULATED AS SIO2, BETWEEN ABOUT 2% BY WEIGHT AND ABOUT 17% BY WEIGHT, BASED ON SAID PIGMENTARY TIO2.
Claim 3
Dependent Claim
44 words
Coated TiO2 pigment according to claim 1 wherein said silica in said porous inner coating is present in an amount between about 1% and 11% and wherein said alumina in said porous inner coating is present in an amount between about 1% and 10%.
Claim 4
Dependent Claim
54 words
Coated TiO2 pigment according to claim 1 wherein said silica in said porous inner coating is present in an amount of about 7%, said alumina in said porous inner coating is present in an amount of about 6%, and said silica in said dense outer coating is present in an amount of about 8%.
Claim 5
Dependent Claim
36 words
Coated TiO2 pigment according to claim 1 having a porous outer coating of alumina present in an amount, calculated as A12O3, between about 0.5% by weight to about 5% by weight, based on said pigmentary TiO2.
Claim 6
Dependent Claim
54 words
Coated TiO2 pigment according to claim 4 wherein said silica in said porous inner coating is present in an amount of about 7%, said alumina in said porous inner coating is present in an amount of about 6%, and said silica in said dense outer coating is present in an amount of about 8%.
Claim 7
Dependent Claim
54 words
Coated TiO2 pigment according to claim 4 wherein said silica in said porous inner coating is present in an amount of about 3%, said alumina in said porous inner coating is present in an amount of about 6%, and said silica in said dense outer coating is present in an amount of about 8%.
Claim 8
Dependent Claim
162 words
Process for preparing coated TiO2 pigment by the steps of: i. adding to an aqueous slurry of pigmentary TiO2, maintained at a pH below about 7.5, an aqueous solution of soluble silicate in an amount calculated to provide less than about 12% by weight of silica, calculated as SiO2, based on said pigmentary TiO2, ii. adding to slurry, maintained at a pH between about 6 to 10, an aqueous solution of soluble aluminate in an amount calculated to provide less than about 11% by weight of alumina, calculated as A12O3, based on said pigmentary TiO2, iii. adjusting the pH of said slurry to between about 9 and 10, iv. adding to said slurry an aqueous solution of soluble silicate in an amount calculated to provide from about 3% to about 16% by weight of silica, based on said pigmentary TiO2, and v. slowly adding dilute acid to said slurry until the pH of said slurry is between about 6 and about 7.7.
Claim 9
Dependent Claim
162 words
Process for preparing coated TiO2 pigment by the steps of: i. adding to an aqueous slurry of pigmentary TiO2, maintained at a pH below about 7.5, an aqueous solution of soluble silicate in an amount calculated to provide less than about 12% by weight of silica, calculated as SiO2, based on said pigmentary TiO2, ii. adding to slurry, maintained at a pH between about 6 to 10, an aqueous solution of soluble aluminate in an amount calculated to provide less than about 11% by weight of alumina, calculated as A12O3, based on said pigmentary TiO2, iii. adjusting the pH of said slurry to between about 9 and 10, iv. adding to said slurry an aqueous solution of soluble silicate in an amount calculated to provide from about 3% to about 16% by weight of silica, based on said pigmentary TiO2, and v. slowly adding dilute acid to said slurry until the pH of said slurry is between about 6 and about 7.7.
Claim 10
Dependent Claim
25 words
Process for preparing coated TiO2 pigment according to claim 7 wherein said dilute acid of step (v) has a normality of less than about 4.
Claim 11
Dependent Claim
30 words
Process for preparing coated TiO2 pigment according to claim 7 wherein said aqueous slurry of pigmentary TiO2 is heated to a temperature of at least 40*C. prior to step (i).
Claim 12
Dependent Claim
29 words
Process for preparing coated TiO2 pigment according to claim 7 wherein said slurry of pigmentary TiO2 is heated to a temperature of at least 70*C. prior to step (i).
Claim 13
Dependent Claim
24 words
Process for preparing coated TiO2 pigment according to claim 10 wherein said slurry is cured for at least 30 minutes prior to step (ii).
Claim 14
Dependent Claim
39 words
Process for preparing coated TiO2 pigment according to claim 11 wherein, following step (v), said slurry is cured for at least One hour at about 90*C. while maintaining the pH of said slurry between about 7.3 and about 7.6.
Claim 15
Dependent Claim
62 words
Process for preparing coated TiO2 pigment according to claim 10 by the additional step of: vi. adding to slurry an aqueous solution of a soluble aluminate in an amount calculated to provide from about 0.5% to about 5% by weight of alumina, calculated as A12O3, based on said pigmentary TiO2 while maintaining the pH of said slurry between about 3 and 8.
Claim 16
Dependent Claim
23 words
Process for preparing coated TiO2 pigment according to claim 13 wherein said slurry is maintained between about 6 and 8 during step (ii).
Claim 17
Dependent Claim
26 words
Process for preparing coated TiO2 pigment according to claim 13 wherein the pH of said slurry is maintained between about 3 and 4 during step (vi).
Claim 18
Dependent Claim
26 words
Process for preparing coated TiO2 pigment according to claim 15 wherein said slurry is heated to a temperature of at least 90*C. prior to step (iv).
Claim 19
Dependent Claim
26 words
Process for preparing coated TiO2 pigment according to claim 13 wherein the pH of said slurry is maintained between about 6 and 8 during step (vi).
Claim 20
Dependent Claim
41 words
Process for preparing coated TiO2 pigment according to claim 17 wherein said dilute acid of step (v) is added to said slurry over a period of at least 45 minutes while maintaining the temperature of said slurry at at least 90*C.
References Cited (Backward Citations)
US3515566A
Cited
US3410708A
Cited
US3510335A
Cited
US3437502A
Cited
US3545994A
Cited
US3649322A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |