US4345037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkali resistant glass fibres for cement reinforcement
Assignee: Pilkington Group Ltd
•
Filing: 1981-02-26
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Granted: 1982-08-17
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Expires: 2001-02-26
Abstract
Abstract Alkali-resistant glass fibres for use as reinforcement in cementitious products are formed from a composition comprising, in weight percentages: ______________________________________ SiO 2 55 to 75% R 2 O 11 to 23% ZrO 2 6 to 22% Cr 2 O 3 0.1 to 1% Al 2 O 3 0.1 to 7% Rare earth oxides + TiO 2 0.5 to 16% ______________________________________ where R 2 O is any one or more of Na 2 O, K 2 O or Li 2 O, the content of TiO 2 does not exceed 10%, and the total of the components recited above amounts to at least 88% by weight of the glass, the glass having been melted under non-oxidizing conditions such that all or a substantial proportion of the chromium in the glass is in the trivalent state. Cementitious products incorporating such fibres, e.g. in a proportion of 3 to 6 weight %, can be made using a Magnani-type asbestos cement machine or by a "spray-up" method.
Inventors
- 👤 Kenneth M. Fyles
- 👤 Peter Shorrock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:14
CPC Classifications
D; D03; D03D; D03D37/00; C; C04; C04B; C04B14/00; C04B14/38; C04B14/42; C03; C03C; C03C13/00; C03C13/001; C03C13/002
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
124 words
Alkali-resistant glass fibres for use as reinforcement in cementitious products, formed from a composition comprising, in weight percentages: ______________________________________
SiO.sub.2 55 to 75%
R.sub.2 O 11 to 23%
ZrO.sub.2 6 to 22%
Cr.sub.2 O.sub.3 0.1 to 1%
Al.sub.2 O.sub.3 0.1 to 7%
Rare earth oxides + TiO.sub.2
0.5 to 16%
______________________________________ where R 2 O is any one or more of Na 2 O, K 2 O or Li 2 O, the content of TiO 2 does not exceed 10%, and the total of the components recited above amounts to at least 88% by weight of the glass, the glass having been melted under non-oxidising conditions such that all or a substantial proportion of the chromium in the glass is in the trivalent state.
Claim 2
Dependent Claim
124 words
Alkali-resistant glass fibres for use as reinforcement in cementitious products, formed from a composition comprising, in weight percentages: ______________________________________
SiO.sub.2 55 to 75%
R.sub.2 O 11 to 23%
ZrO.sub.2 6 to 22%
Cr.sub.2 O.sub.3 0.1 to 1%
Al.sub.2 O.sub.3 0.1 to 7%
Rare earth oxides + TiO.sub.2
0.5 to 16%
______________________________________ where R 2 O is any one or more of Na 2 O, K 2 O or Li 2 O, the content of TiO 2 does not exceed 10%, and the total of the components recited above amounts to at least 88% by weight of the glass, the glass having been melted under non-oxidising conditions such that all or a substantial proportion of the chromium in the glass is in the trivalent state.
Claim 3
Dependent Claim
36 words
Glass fibres according to claim 1 wherein the composition further comprises R'O up to 9% by weight, where R'O is any one or more of MgO, CaO, SrO, BaO, ZnO, FeO, MnO, CoO, NiO and CuO.
Claim 4
Dependent Claim
23 words
Glass fibres according to claim 1 wherein the content of Al 2 O 3 does not exceed 5% when ZrO 2 exceeds 13%.
Claim 5
Dependent Claim
20 words
Glass fibres according to claim 1 wherein the composition further comprises B 2 O 3 up to 5% by weight.
Claim 6
Dependent Claim
33 words
Glass fibres according to claim 1 wherein the composition further comprises PbO up to 2% by weight the glass having been melted under conditions which avoid formation of lead metal in the glass.
Claim 7
Dependent Claim
18 words
Glass fibres according to claim 1 wherein the composition further comprises ThO 2 up to 4% by weight.
Claim 8
Dependent Claim
17 words
Glass fibres according to claim 1 wherein the composition further comprises F up to 1% by weight.
Claim 9
Dependent Claim
38 words
Glass fibres according to claim 1 wherein the composition further comprises any one of V 2 O 5 , Ta 2 O 5 , MoO 3 or HfO 2 in an amount of up to 2% by weight.
Claim 10
Dependent Claim
17 words
Glass fibres according to claim 1 wherein the content of rare earth oxides does not exceed 10%.
Claim 11
Dependent Claim
25 words
Glass fibres according to claim 1 wherein the content of rare earth oxides exceeds 2.8% and the content of TiO 2 does not exceed 5%.
Claim 12
Dependent Claim
37 words
Glass fibres according to claim 1 wherein the amounts of the individual R 2 O components are within the ranges: ______________________________________
Na.sub.2 O 6 to 20%
K.sub.2 O 0 to 10%
Li.sub.2 O 0 to 3%
______________________________________
Claim 13
Dependent Claim
19 words
Glass fibres according to claim 1 wherein the total content of R 2 O is from 14 to 17%.
Claim 14
Dependent Claim
17 words
Glass fibres according to claim 1 wherein the content of SiO 2 is from 57 to 69%.
Claim 15
Dependent Claim
10 words
Cementitious products reinforced with glass fibres according to claim 1.
Claim 16
Dependent Claim
21 words
Cementitious products according to claim 14, comprising from 3 to 6 weight % of the glass fibres in a cementitious matrix.
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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) | 1985-08-16 | 1986-02-15 | 1986-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-16 | 1990-02-15 | 1990-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-16 | 1994-02-15 | 1994-08-17 | $7700.00 | Window Closed / Lapsed |