Patent US4681749A successfully refreshed from Google Patents.
US4681749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of synthetic crystalline zinc silicate mineral having a sauconite, willemite or hemimorphite structure
Assignee: Mizusawa Industrial Chemicals Ltd
•
Filing: 1985-06-21
•
Granted: 1987-07-21
•
Expires: 2005-06-21
Abstract
Abstract A crystalline zinc silicate mineral of the sauconite, hemimorphite or willemite type is prepared by subjecting an acid-treated product of a clay mineral and an oxide or hydroxide of zinc or a compound capable of forming this oxide or hydroxide under reaction conditions to a hydrothermal treatment. This crystalline zinc silicate mineral has a fine and uniform particle size and is excellent in the pigmenting characteristics.
Inventors
- 👤 Koichi Usui
- 👤 Teiji Sato
- 👤 Masanori Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:52
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/124; B41M5/132; B41M5/155; B41M5/1555; C; C01; C01B; C01B33/00; C01B33/20; C08; C08K; C08K3/00; C08K3/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
139 words
A process for the preparation of a zinc silicate of the sauconite structure represented by the following formula: Zn.sub.3 Si.sub.4 O.sub.10 (OH).sub.2, which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane index (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid-treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions, to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 3/4 at a temperature of 130° to 170° C. and a spontaneous pressure corresponding to the temperature.
Claim 2
Dependent Claim
139 words
A process for the preparation of a zinc silicate of the sauconite structure represented by the following formula: Zn.sub.3 Si.sub.4 O.sub.10 (OH).sub.2, which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane index (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid-treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions, to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 3/4 at a temperature of 130° to 170° C. and a spontaneous pressure corresponding to the temperature.
Claim 3
Dependent Claim
27 words
A process according to claim 1, wherein the acid treatment of the clay mineral is carried out at 60° to 300° C. for 10 to 600 minutes.
Claim 4
Dependent Claim
63 words
A process according to claim 1, wherein before the hydrothermal treatment, the particle size of the acid-treated product of the clay mineral is adjusted so that particles having a particle size smaller than 5μ occupy at least 20% by weight of the total particles and particles having a particle size larger than 20μ occupy less than 30% by weight of the total particles.
Claim 5
Dependent Claim
23 words
A process according to claim 1, wherein the hydrothermal treatment is carried out under a pressure of 2 to 50 kg/cm 2 gauge.
Claim 6
Dependent Claim
17 words
A process according to claim 1, wherein the hydrothermal treatment is conducted for 1 to 10 hours.
Claim 7
Dependent Claim
140 words
A process for the preparation of a zinc silicate of the hemimorphite structure represented by the following formula: Zn.sub.4 Si.sub.2 O.sub.7 (OH).sub.2 which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane index (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions, to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 2/1 at a temperature of 150° to 250° C. and a spontaneous pressure corresponding to the temperature.
Claim 8
Dependent Claim
140 words
A process for the preparation of a zinc silicate of the hemimorphite structure represented by the following formula: Zn.sub.4 Si.sub.2 O.sub.7 (OH).sub.2 which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane index (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions, to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 2/1 at a temperature of 150° to 250° C. and a spontaneous pressure corresponding to the temperature.
Claim 9
Dependent Claim
27 words
A process according to claim 6 wherein the acid treatment of the clay mineral is carried out at 60° to 300° C. for 10 to 600 minutes.
Claim 10
Dependent Claim
63 words
A process according to claim 6 wherein before the hydrothermal treatment, the particle size of the acid-treated product of the clay mineral is adjusted so that particles having a particle size smaller than 5μ occupy at least 20% by weight of the total particles and particles having a particle size larger than 20μ occupy less than 30% by weight of the total particles.
Claim 11
Dependent Claim
28 words
A process according to claim 6 wherein the hydrothermal treatment is carried out under a pressure of 2 to 50 kg/cm 2 gauge for 1 to 10 hours.
Claim 12
Dependent Claim
135 words
A process for the preparation of a zinc silicate of the willemite structure represented by the following formula: Zn.sub.2 SiO.sub.4 which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid-treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 2/1 at a temperature greater than 200° C. and a spontaneous pressure corresponding to the temperature.
Claim 13
Dependent Claim
135 words
A process for the preparation of a zinc silicate of the willemite structure represented by the following formula: Zn.sub.2 SiO.sub.4 which comprises (1) subjecting a clay mineral of the smectite group to an acid treatment to such an extent that the X-ray diffraction peak of the plane (001) of the clay mineral substantially disappears and the Al 2 O 3 /SiO 2 molar ratio of the acid-treated product is within the range of from 1/11 to 1/99, and (2) subjecting the acid-treated product of the clay mineral and an oxide or hydroxide of zinc or a compound capable of forming said oxide or hydroxide under reaction conditions to a hydrothermal treatment at a ZnO/SiO 2 molar ratio of about 2/1 at a temperature greater than 200° C. and a spontaneous pressure corresponding to the temperature.
Claim 14
Dependent Claim
27 words
A process according to claim 10 wherein the acid treatment of the clay mineral is carried out at 60° to 300° C. for 10 to 600 minutes.
Claim 15
Dependent Claim
63 words
A process according to claim 10 wherein before the hydrothermal treatment, the particle size of the acid-treated product of the clay mineral is adjusted so that particles having a particle size smaller than 5μ occupy at least 20% by weight of the total particles and particles having a particle size larger than 20μ occupy less than 30% by weight of the total particles.
Claim 16
Dependent Claim
28 words
A process according to claim 10 wherein the hydrothermal treatment is carried out under a pressure of 2 to 50 kg/cm 2 gauge for 1 to 10 hours.
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) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |