WO1991016273A1 - Calcia-aluminoborosilicate glass compositions - Google Patents
Calcia-aluminoborosilicate glass compositions Download PDFInfo
- Publication number
- WO1991016273A1 WO1991016273A1 PCT/US1991/002334 US9102334W WO9116273A1 WO 1991016273 A1 WO1991016273 A1 WO 1991016273A1 US 9102334 W US9102334 W US 9102334W WO 9116273 A1 WO9116273 A1 WO 9116273A1
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- WO
- WIPO (PCT)
- Prior art keywords
- glass
- cao
- composition according
- glass composition
- microspheres
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
- C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C11/00—Multi-cellular glass ; Porous or hollow glass or glass particles
- C03C11/002—Hollow glass particles
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/062—Glass compositions containing silica with less than 40% silica by weight
- C03C3/064—Glass compositions containing silica with less than 40% silica by weight containing boron
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Glass Compositions (AREA)
Abstract
Glass compositions for use in the preparation of glass microspheres and having reduced 2 Pas (20 poise) temperatures comprise 38 to 44 % SiO2, 14 to 22 % B2O3, 9 to 16 % Al2O3, 22 to 26 % CaO and optionally MgO, 0 to 8 % Na2O, 0 to 2 % Li2O, 0 to 2 % K2O and 0 to 1 % Fe2O3, the sum of B2O3 and Na2O being at least 19 %, said percentage by weight.
Description
CALCIA - ALUMINOBOROSILICATE GLASS COMPOSITIONS
The invention relates to glass compositions for use in the preparation of glass microspheres.
Background of the Invention Hollow glass microspheres (e.g. 0.5 mm) are used, for example, as bulk, lightweight fillers for reinforced plastic components for the motor industry. They find use also as hollow microbubbles for adhesives. They can be prepared, for example, by pulsing an inert gas, such as argon into a continuous stream of molten glass in order to produce individual microspheres. For best results, the molten glass should be at a temperature such that the melt has a viscosity of about 2 Pas (20 poise). This temperature is known as the 20 poise temperature (20 PT). The glass compositions previously proposed for use in the preparation of hollow glass microspheres in this way have had 20 PT values in the region of 1440° to 1450°C. For example, a standard E- Glass composition (analyzing 53.4 wt % SiO2, 13.9 wt % Al2O3, 8.9 wt % B2O3, 21.7 wt % CaO, 0.3 wt % Na2O and 0.7 wt % K2O), such as is used in providing glass fibers for reinforcing plastics, has a 20 PT of 1447°C. A borosilicate glass composition used in the preparation of
glass microspheres (analyzing 44.7 wt % SiO2, 12.5 wt %
Al2O3, 14.1 wt % B2O3, 26.3 wt % CaO, 0.6 wt % Na2O and
0.7 wt % K2O) has a PT of 1444°C. Such high 20 PT values can cause a reduced service life for metal parts, such as platinum bushings, employed in the manufacture of microspheres and are of course associated with high energy requirements. Accordingly it is desired to provide glass compositions suitable for use in the preparation of glass microspheres but having lower 20 PT values than the glass compositions hitherto used.
Description of the Invention
This invention provides glass compositions for use in the preparation of glass microspheres comprising 38 to 44% SiO2, 14 to 22% B2O3, 9 to 16% Al2O3, 22 to 26% CaO, 0 to 8% Na2O, 0 to 2 % Li2O, 0 to 2% K2O and 0 to 1% Fe2O3, the sum of B2O3 and Na2O being at least 19%, said percentages being by weight. Optionally, a portion of the CaO in the composition, such as up about 50%, may be substituted by MgO.
Preferably the glass composition comprises 39 to 43% SiO2, 19 to 22% B2O3, 9 to 13% Al2O3, 22 to 26% CaO and optionally MgO, 4 to 6% Na2O, 0 to 1% K2O and 0.2 to 0.4% Fe2O3. A particularly preferred composition is
one which consists essentially of about 40% SiO2, about
11% Al2O3, about 20% B2O3, about 23% CaO, about 5% Na2O, about 1% K2O, and about 0.3% Fe2O3, said percentages by weight. The glass compositions provided in accordance with this invention preferably have 20 PT values below about 1350°C, especially below 1300°C.
The B2O3 content, either alone or combined with the Na2O content, has an important effect in reducing the 20 PT value. When the B2O3 content is too high, say 25 to 30 wt %, the glass becomes opalescent and its viscosity is undesirably increased. The optimum B2O3 content is from 20 to 21% when the glass composition contains 0 to 5% Na2O.
Additions of Li2O and/or Na2O have been found to be effective in lowering 20 PT values. However, the durability of glasses containing too much of these ingredients can be adversely affected. Durability is measured as the amount of sodium (or alkali equivalent) leached from a glass after treatment in water for 1 hour at 98°C. (See ISO-719-1985 "Glass-Hydrolytic Resistance of Glass Grains at 98°C, Materials for Test and Classification"). Sodium loss provides an inverse measure of durability, i.e. more durable glasses have low sodium losses. A balance should therefore be sought
between improving (lowering) the 20 PT value and worsening the durability. A particularly preferred Na2O content is about 5 wt % since it has been found that this amount of Na2O can be more effective in lowering the 20 PT value than a lower amount (e.g. 2.5 wt %) or higher amount (e.g. about 7.5 wt %). Weight for weight Li2O is more effective in reducing the viscosity of a glass (i.e. is a better flux) than Na2O, but is more expensive.
Al2O3 is a refractory material and increases the viscosity of most glasses. It is generally added to glasses to improve their aqueous durability. The optimum amount is from 9 to 14%, especially 9 to 11%, Al2O3.
Preferably the glass compositions contain CaO rather than both CaO and MgO . Nevertheless mixtures of CaO and MgO can be used if desired, the amount of MgO suitably being up to about half the total amount of CaO and MgO.
Fe2O3 is normally present in E-type glasses to improve radiation heat transfer into the glass during gas firing and heat radiation from fibers during cooling. It can be present, for example in amounts of up to 1 wt %, preferably 0.2 to 0.4 wt %, especially about 0.3 wt %, in the glass compositions of this invention to improve heat
transfer. Fe2O3 also contributes to the fluxing action.
This invention also relates to the use of the glass compositions in the preparation of glass microspheres. This can suitably be done by pulsing an inert gas, preferably argon, into a continuous melt of said glass compositions to produce individual microspheres. The melt will preferably have a viscosity of about 2 Pas (20 poise).
EXAMPLES The invention is illustrated by reference to the following Examples and comparative Examples.
Glass formulations were melted. The viscosity: temperature relationships were measured and the temperature at which the viscosity was 2 Pas (20 poise) was extrapolated (above 1400°C) or interpolated (below 1400°C). Details of the target compositions and of the results of analysis are given in the following Table, together with the 20 PT values. For some of the glasses durability was measured in accordance with the method referred to above and the results also appear in the Table. Examples 13-21 are comparative examples.
G
I
A comparison of the properties of Examples 1-12 with examples 13-21 shows the significant improvement in viscosity obtained with the compositions of this invention while retaining their aqueous durability and other desirable properties.
Various changes and modifications of the invention can be made and, to the extent that such variations incorporate the spirit of this invention, they are intended to be included within the scope of the appended claims.
Claims
1. A glass composition for use in the preparation of glass microspheres comprising 38 to 44% SiO2, 14 to 22% B2O3, 9 to 16% Al2O3, 22 to 26% CaO, 0 to 8% Na2O, 0 to 2% Li2O, 0 to 2% K2O and 0 to 1% Fe2O3, the sum of B2O3 and Na2O being at least 19%, said percentages by weight.
2. A glass composition according to claim 1 which comprises 39 to 43% SiO2, 19 to 22% B2O3, 9 to 13% Al2O3, 22 to 26% CaO, 4 to 6% Na2O and 0 to 1% K2O.
3. A glass composition according to claim 1 which contains 20 to 21% B2O3 and 0 to 5% Na2O.
4. A glass composition according to claim 1 consisting essentially of about 40% SiO2, about 11% Al2O3, about 20% B2O3, about 23% CaO, about 5% Na2O and about 1% K2O.
5. A glass composition according to claim 1 in which up to about 50% of said CaO is replaced by MgO.
6. A glass composition according to claim 2 in which up to about 50% of said CaO is replaced by MgO.
A glass composition according to claim 2 in which 0.2 to 0.4% Fe2O3 is included.
8. A glass composition according to claim 2 which contains 20 to 21% B2O3.
9. A glass composition according to claim 4 in which about 0.3% Fe2O3 is included.
10. In the production of hollow glass microspheres by pulsing an inert gas into a continuous stream of molten glass, thereby forming individual microspheres of said glass, the improvement which comprises employing as said glass a composition according to claim 1.
11. The process according to claim 10 in which said molten glass has a viscosity of about 2 Pas (20 poise).
12. The process according to claim 10 in which said inert gas is argon.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB9009246.1 | 1990-04-25 | ||
GB9009246A GB2243604A (en) | 1990-04-25 | 1990-04-25 | Glass compositions |
US07/554,059 US5100842A (en) | 1990-04-25 | 1990-07-16 | Glass compositions |
US554,059 | 1990-07-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991016273A1 true WO1991016273A1 (en) | 1991-10-31 |
Family
ID=26296991
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1991/002334 WO1991016273A1 (en) | 1990-04-25 | 1991-04-04 | Calcia-aluminoborosilicate glass compositions |
Country Status (1)
Country | Link |
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WO (1) | WO1991016273A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2017236A1 (en) * | 2006-05-02 | 2009-01-21 | Nippon Sheet Glass Company, Limited | Glass composition and glass spacer using the same |
WO2015013129A1 (en) * | 2013-07-23 | 2015-01-29 | Rogers Corporation | Circuit materials, circuit laminates, and methods of manufacture thereof |
EP3184494A1 (en) * | 2015-12-21 | 2017-06-28 | ADF Materials GmbH | Chemical composition for production of hollow spherical glass particles with high compressive strength |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2681289A (en) * | 1950-03-04 | 1954-06-15 | Gustin Bacon Mfg Co | Glass composition |
US2834738A (en) * | 1954-08-25 | 1958-05-13 | Ici Ltd | Production of skeletal glass catalysts |
US3150947A (en) * | 1961-07-13 | 1964-09-29 | Flex O Lite Mfg Corp | Method for production of glass beads by dispersion of molten glass |
US3207588A (en) * | 1962-03-16 | 1965-09-21 | Owens Corning Fiberglass Corp | Glass foam |
US3459630A (en) * | 1965-09-23 | 1969-08-05 | Pittsburgh Corning Corp | Arcuately shaped cellular glass article and method of making the same |
US3843376A (en) * | 1971-04-24 | 1974-10-22 | Philips Corp | Method of manufacturing a mixture for a borosilicate glass |
US4215033A (en) * | 1978-09-08 | 1980-07-29 | American Dental Association Health Foundation | Composite dental material |
US4983550A (en) * | 1988-08-24 | 1991-01-08 | Potters Industries, Inc. | Hollow glass spheres |
-
1991
- 1991-04-04 WO PCT/US1991/002334 patent/WO1991016273A1/en unknown
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2681289A (en) * | 1950-03-04 | 1954-06-15 | Gustin Bacon Mfg Co | Glass composition |
US2834738A (en) * | 1954-08-25 | 1958-05-13 | Ici Ltd | Production of skeletal glass catalysts |
US3150947A (en) * | 1961-07-13 | 1964-09-29 | Flex O Lite Mfg Corp | Method for production of glass beads by dispersion of molten glass |
US3207588A (en) * | 1962-03-16 | 1965-09-21 | Owens Corning Fiberglass Corp | Glass foam |
US3459630A (en) * | 1965-09-23 | 1969-08-05 | Pittsburgh Corning Corp | Arcuately shaped cellular glass article and method of making the same |
US3843376A (en) * | 1971-04-24 | 1974-10-22 | Philips Corp | Method of manufacturing a mixture for a borosilicate glass |
US4215033A (en) * | 1978-09-08 | 1980-07-29 | American Dental Association Health Foundation | Composite dental material |
US4983550A (en) * | 1988-08-24 | 1991-01-08 | Potters Industries, Inc. | Hollow glass spheres |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2017236A1 (en) * | 2006-05-02 | 2009-01-21 | Nippon Sheet Glass Company, Limited | Glass composition and glass spacer using the same |
EP2017236A4 (en) * | 2006-05-02 | 2009-12-16 | Nippon Sheet Glass Co Ltd | Glass composition and glass spacer using the same |
WO2015013129A1 (en) * | 2013-07-23 | 2015-01-29 | Rogers Corporation | Circuit materials, circuit laminates, and methods of manufacture thereof |
US9258892B2 (en) | 2013-07-23 | 2016-02-09 | Rogers Corporation | Circuit materials, circuits laminates, and method of manufacture thereof |
CN109951952A (en) * | 2013-07-23 | 2019-06-28 | 罗杰斯公司 | Circuit unit |
CN109951952B (en) * | 2013-07-23 | 2022-02-01 | 罗杰斯公司 | Circuit assembly |
EP3184494A1 (en) * | 2015-12-21 | 2017-06-28 | ADF Materials GmbH | Chemical composition for production of hollow spherical glass particles with high compressive strength |
WO2017108831A1 (en) * | 2015-12-21 | 2017-06-29 | Adf Materials Gmbh | Chemical composition for production of hollow spherical glass particles with high compressive strength |
US10414689B2 (en) | 2015-12-21 | 2019-09-17 | Omya International Ag | Chemical composition for production of hollow spherical glass particles with high compressive strength |
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