US4004935A
Expired / Lapsed
US
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Glazing compositions for ceramic articles
Assignee: Tioxide Group Ltd
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Filing: 1974-11-14
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Granted: 1977-01-25
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Expires: 1994-11-14
Abstract
Abstract A glazed ceramic article in which the glaze includes titanium dioxide at least some of which is in the form of a metal titanate or a metal titano silicate and having a gloss of from 9 to 55 units at 45° illumination. Also a glazing composition is described prepared by a semi-fritting technique in which the composition includes a mixture of a finely divided frit and an unfritted crystalline silica with the titanium dioxide being included in the frit together with alumina and a source of strontium, calcium or magnesium.
Inventors
- 👤 Derek Grosvenor
- 👤 John Robert Frederick Nicholson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:24
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/02; C03C2205/00; C03C2205/02; C03C2209/00
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
184 words
A substantially lead-free glazing composition capable of forming a glaze with a gloss of from 9-55 units measured at 45°, on ceramic articles when fired at a temperature of 950°-1200° C., comprising a finely--divided frit, an unfritted crystalline silica, water and optionally a clay, in which said frit comprises as essential ingredients silica (SiO 2 ) in an amount of from 25 to 55 mole percent, titanium dioxide (TiO 2 ) in an amount of from 7 to 20 mole percent, alkali metal oxides (M 2 O) in an amount of from 10 to 25 mole percent, and strontium, calcium or magnesium (as oxide) in an amount of from 5 to 15 mole percent, alumina (Al 2 O 3 ) in an amount of from 5 to 15 mole percent, and boron (B 2 O 3 ) in an amount of from 0 to 10 mole percent, the amount of said unfritted crystalline silica being such that the silica content of the final glazing composition is increased from 5 to 28 weight percent (SiO 2 ) relative to the silica content of the frit.
Claim 2
Dependent Claim
184 words
A substantially lead-free glazing composition capable of forming a glaze with a gloss of from 9-55 units measured at 45°, on ceramic articles when fired at a temperature of 950°-1200° C., comprising a finely--divided frit, an unfritted crystalline silica, water and optionally a clay, in which said frit comprises as essential ingredients silica (SiO 2 ) in an amount of from 25 to 55 mole percent, titanium dioxide (TiO 2 ) in an amount of from 7 to 20 mole percent, alkali metal oxides (M 2 O) in an amount of from 10 to 25 mole percent, and strontium, calcium or magnesium (as oxide) in an amount of from 5 to 15 mole percent, alumina (Al 2 O 3 ) in an amount of from 5 to 15 mole percent, and boron (B 2 O 3 ) in an amount of from 0 to 10 mole percent, the amount of said unfritted crystalline silica being such that the silica content of the final glazing composition is increased from 5 to 28 weight percent (SiO 2 ) relative to the silica content of the frit.
Claim 3
Dependent Claim
29 words
A glazing composition according to claim 1 in which said frit contains boron oxide (B 2 O 3 ) in an amount of from 3 to 10 mole percent.
Claim 4
Dependent Claim
33 words
A glazing composition according to claim 1 in which clay is included and the amount of clay as from 2.5 to 7.5 weight percent based on the solids content of the glazing composition.
Claim 5
Dependent Claim
23 words
A glazing composition according to claim 1 in which said unfritted crystalline silica is selected from the group consisting of quartz and flint.
Claim 6
Independent Claim
207 words
A method for the production of a glazing composition comprising mixing together silica (SiO 2 ) in an amount of from 25 to 55 mole percent, titanium dioxide (TiO 2 ) in an amount of from 7 to 20 mole percent, alumina (Al 2 O 3 ) in an amount of from 5 to 15 mole percent, alkali metal oxide (M 2 O) in an amount of from 10 to 25 mole percent, boron (B 2 O 3 ) in an amount of from 0 to 10 mole percent, and strontium, calcium or magnesium (as oxide) in an amount of from 5 to 15 mole percent, heating the mixture so obtained until a homogeneous glass is formed, cooling the heated mixture rapidly to form a frit, grinding the frit and adding to the frit, water and a further amount of unfritted, crystalline silica to provide a glazing composition capable of forming a glaze with a gloss of from 9-55 units, measured at 45°, on ceramic articles when fired at a temperature of 950°-1200° C, the amount of said unfritted crystalline silica being such that the silica content of the glazing composition is increased from 5 to 28 weight percent relative to the silica content of the frit.
Claim 7
Independent Claim
207 words
A method for the production of a glazing composition comprising mixing together silica (SiO 2 ) in an amount of from 25 to 55 mole percent, titanium dioxide (TiO 2 ) in an amount of from 7 to 20 mole percent, alumina (Al 2 O 3 ) in an amount of from 5 to 15 mole percent, alkali metal oxide (M 2 O) in an amount of from 10 to 25 mole percent, boron (B 2 O 3 ) in an amount of from 0 to 10 mole percent, and strontium, calcium or magnesium (as oxide) in an amount of from 5 to 15 mole percent, heating the mixture so obtained until a homogeneous glass is formed, cooling the heated mixture rapidly to form a frit, grinding the frit and adding to the frit, water and a further amount of unfritted, crystalline silica to provide a glazing composition capable of forming a glaze with a gloss of from 9-55 units, measured at 45°, on ceramic articles when fired at a temperature of 950°-1200° C, the amount of said unfritted crystalline silica being such that the silica content of the glazing composition is increased from 5 to 28 weight percent relative to the silica content of the frit.
Claim 8
Dependent Claim
17 words
A method according to claim 5 in which the source of alkali metal is a sodium salt.
Claim 9
Dependent Claim
17 words
A method according to claim 5 in which the source of alkali metal is a potassium salt.
Claim 10
Dependent Claim
23 words
A method according to claim 5 in which the alumina is mixed with the other ingredients in the form of hydrated aluminum oxide.
Claim 11
Dependent Claim
19 words
A method according to claim 5 in which the source of strontium, calcium or magnesium is an inorganic salt.
Claim 12
Dependent Claim
38 words
A method according to claim 5 in which a source of boron (B 2 O 3 ) is mixed with the titanium dioxide, silica, alumina and other ingredients in an amount of from 3 to 10 mole percent.
Claim 13
Dependent Claim
18 words
A method according to claim 10 in which the boron is added in the form of hydrated borax.
Claim 14
Dependent Claim
14 words
A method according to claim 5 in which the silica is added as quartz.
Claim 15
Dependent Claim
14 words
A method according to claim 5 in which the silica is added as flint.
Claim 16
Dependent Claim
15 words
A method according to claim 5 in which the titanium dioxide is pigmentary titanium dioxide.
Claim 17
Dependent Claim
27 words
A method according to claim 5 in which the titanium dioxide is granular titanium dioxide having a particle size within the range 10 microns to 850 microns.
Claim 18
Dependent Claim
23 words
A method according to claim 5 in which the source of titanium dioxide contains at least 95 percent by weight TiO 2 .
Claim 19
Dependent Claim
26 words
a method according to claim 5 in which the mixture is heated at a temperature of up to 1400° C until a homogeneous glass is formed.
Claim 20
Dependent Claim
21 words
A method according to claim 17 in which the mixture is heated at a temperature of not less than 1150° C.
Claim 21
Dependent Claim
22 words
A method according to claim 16 in which the mixture is heated for a time of from 30 minutes to 2 hours.
Claim 22
Dependent Claim
18 words
A method according to claim 5 in which the heated mixture is cooled rapidly by quenching with water.
Claim 23
Dependent Claim
16 words
A method according to claim 5 in which the heated mixture is cooled rapidly in air.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |