US4443550A
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US
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Glass composition suitable for production of fibrous wollastonite, method for producing said wollastonite, and wollastonite obtained thereby
Assignee: Nippon Sheet Glass Co Ltd
•
Filing: 1981-09-01
•
Granted: 1984-04-17
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Expires: 2001-09-01
Abstract
Abstract A glass composition suitable for production of a fibrous wollastonite comprising, in % by weight: ______________________________________ SiO 2 35 to 60 CaO 30 to 55 B 2 O 3 1 to 30 Li 2 O 0 to 4 Al 2 O 3 0 to 8 and Na 2 O + K 2 O 0 to 8 ______________________________________ a method for producing said fibrous wollastonite using the glass composition, and fibrous wollastonite obtained by the method.
Inventors
- 👤 Makoto Kume
- 👤 Toshiaki Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:56
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/24; C03; C03C; C03C10/00; C03C10/0036; C03C13/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
70 words
A glass composition suitable for production of a fibrous wollastonite consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8,
______________________________________ wherein at least one of Li 2 O, Al 2 O 3 , and Na 2 O is present.
Claim 2
Dependent Claim
70 words
A glass composition suitable for production of a fibrous wollastonite consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8,
______________________________________ wherein at least one of Li 2 O, Al 2 O 3 , and Na 2 O is present.
Claim 3
Dependent Claim
48 words
A glass composition as in claim 1, consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 45 to 55
CaO 35 to 45
B.sub.2 O.sub.3 1 to 6
Li.sub.2 O 0.2 to 2
Al.sub.2 O.sub.3 1 to 6
and Na.sub.2 O + K.sub.2 O
1 to 5.
______________________________________
Claim 4
Independent Claim
127 words
A method for producing a fibrous wollastonite which comprises uniformly and simultaneously heat treating all portions of a glass consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8
______________________________________ to form a crystallized glass containing therein bundles of needle wollastonite crystals, and thereafter treating the crystallized glass to disintegrate the bundles of the wollastonite crystals by one or more treatment methods including pulverization, rapid cooling of crystallized glass heated to high temperatures, and immersion of the crystallized glass in an aqueous alkaline eluting solution to selectively elute only the glass phase present in the crystallized glass.
Claim 5
Independent Claim
127 words
A method for producing a fibrous wollastonite which comprises uniformly and simultaneously heat treating all portions of a glass consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8
______________________________________ to form a crystallized glass containing therein bundles of needle wollastonite crystals, and thereafter treating the crystallized glass to disintegrate the bundles of the wollastonite crystals by one or more treatment methods including pulverization, rapid cooling of crystallized glass heated to high temperatures, and immersion of the crystallized glass in an aqueous alkaline eluting solution to selectively elute only the glass phase present in the crystallized glass.
Claim 6
Dependent Claim
51 words
A method as in claim 3, wherein the glass composition consists essentially of, in % by weight: ______________________________________
SiO.sub.2 45 to 55
CaO 35 to 45
B.sub.2 O.sub.3 1 to 6
Li.sub.2 O 0.2 to 2
Al.sub.2 O.sub.3 1 to 6
and Na.sub.2 O + K.sub.2 O
1 to 5.
______________________________________
Claim 7
Dependent Claim
24 words
A method as in claim 3, wherein the heat treatment is conducted at from 750° C. to 1,150° C. for at least 2 hours.
Claim 8
Dependent Claim
12 words
A method as in claim 3, wherein the physical treatment is pulverization.
Claim 9
Dependent Claim
31 words
A method as in claim 3, wherein the physical treatment is a method comprising rapidly cooling the crystallized glass heated at high temperature to cleave bundles of the needle wollastonite crystals.
Claim 10
Dependent Claim
34 words
A method as in claim 3, wherein the chemical treatment is a method comprising immersing the crystallized glass in an eluting solution to selectively elute only the glass phase present in the crystallized glass.
Claim 11
Dependent Claim
15 words
A method as in claim 8, wherein the eluting solution is an aqueous alkaline solution.
Claim 12
Dependent Claim
80 words
A method as in claim 9, wherein the glass composition consists essentially of, in % by weight: ______________________________________
SiO.sub.2 45 to 55
CaO 35 to 45
B.sub.2 O.sub.3 1 to 6
Li.sub.2 O 0.2 to 2
Al.sub.2 O.sub.3
1 to 6
and Na.sub.2 O + K.sub.2 O
1 to 7
with Na.sub.2 O 0 to 4 and
K.sub.2 O 1 to 7
______________________________________ wherein the weight ratio of Na 2 O/Na 2 O+K 2 O is from 0/1 to 0.8/1.
Claim 13
Dependent Claim
104 words
A fibrous wollastonite obtained by heat treating a glass consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8
______________________________________
to form a crystallized glass containing therein bundles of needle
wollastonite crystals, and thereafter treating the crystallized glass to
disintegrate the bundles of the wollastonite crystals by a treatment
method comprising immersion of the crystallized glass in an aqueous
alkaline eluting solution to selectively elute only the glass phase
present in the crystallized glass.
Claim 14
Dependent Claim
104 words
A fibrous wollastonite obtained by heat treating a glass consisting essentially of, in % by weight: ______________________________________
SiO.sub.2 35 to 60
CaO 30 to 55
B.sub.2 O.sub.3 1 to 30
Li.sub.2 O 0 to 4
Al.sub.2 O.sub.3 0 to 8
and Na.sub.2 O + K.sub.2 O
0 to 8
______________________________________
to form a crystallized glass containing therein bundles of needle
wollastonite crystals, and thereafter treating the crystallized glass to
disintegrate the bundles of the wollastonite crystals by a treatment
method comprising immersion of the crystallized glass in an aqueous
alkaline eluting solution to selectively elute only the glass phase
present in the crystallized glass.
Claim 15
Dependent Claim
52 words
A fibrous wollastonite as in claim 11, wherein the glass composition consists essentially of, in % by weight: ______________________________________
SiO.sub.2 45 to 55
CaO 35 to 45
B.sub.2 O.sub.3 1 to 6
Li.sub.2 O 0.2 to 2
Al.sub.2 O.sub.3 1 to 6
and Na.sub.2 O + K.sub.2 O
1 to 5.
______________________________________
Claim 16
Dependent Claim
25 words
A fibrous wollastonite as in claim 11, wherein the heat treatment is conducted at from 750° C. to 1,150° C. for at least 2 hours.
Claim 17
Dependent Claim
81 words
A fibrous wollastonite as in claim 11, wherein the glass composition consists essentially of, in % by weight: ______________________________________
SiO.sub.2 45 to 55
CaO 35 to 45
B.sub.2 O.sub.3 1 to 6
Li.sub.2 O 0.2 to 2
Al.sub.2 O.sub.3
1 to 6
and Na.sub.2 O + K.sub.2 O
1 to 7
with Na.sub.2 O 0 to 4 and
K.sub.2 O 1 to 7
______________________________________ wherein the weight ratio of Na 2 O/Na 2 O+K 2 O is from 0/1 to 0.8/1.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |