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US3901720A Expired / Lapsed US ⏱️ 0.0 years remaining

Glass fibres and compositions containing glass fibres

Assignee: National Research Development Corp UK
•
Filing: 1973-02-12
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Granted: 1975-08-26
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Expires: 1993-02-12
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Abstract

Abstract Fibre reinforced cementitious products are described comprising glass fibrous material distributed throughout a cement matrix, in which the glass is one having per se a degree of alkali resistance such that when tested in the form of an abraded fibre of length 2 1/2 inches and diameter of from 0.4 to 1.0 X 10 3 inches said fibre has a tensile strength of at least 100,000 p.s.i. after treatment with saturated aqueous Ca(OH)2 solution at 100*C. for 4 hours followed by successive washings at ambient temperature with water, then with aqueous hydrochloric acid (1%) for 1 minute, water, acetone, following by drying, said fibre experiencing not more than 10% reduction in diameter during said test. The reinforcement of Portland cement structures by fibres of diameter 0.4 to 1.0 X 10 3 and lengths of up to 4 inches is described. Alkali resistant glasses useful for production of these products comprise the CaO-MgO-Al2O3-SiO2 glasses including those in the anorthite field, silica zirconia glasses, and silica stannic oxide glasses. The products have outstanding durability and impact resistance.

Inventors

  • 👤 Amalendu Jyoti Majumdar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 12:44
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C13/00; C03C13/001; C03C13/002; C03C3/078; C03C3/083; C03C3/085; C03C3/087; C03C3/095; C03C3/11; C03C3/112; C04; C04B; C04B14/00; C04B14/38; C04B14/42; C04B26/00; C04B26/02; C04B26/10; C04B28/00; C04B28/02; C04B28/04

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 129 words
AN ALKALI-RESISTANT GLASS FIBRE DERIVED FROM A GLASS CONSISTING ESSENTIALLY OF, IN PERCENT BY WEIGHT, 65-80% SIO2, 10-20% ZRO2, AND 10-20% OF AT LEAST ONE NETWORK MODIFIER WHICH IS AN ALKALI METAL OXIDE, AN ALKALINE EARTH METAL OXIDE, OR ZNO, SAID GLASS BEING ONE WHICH HAS A TENSILE STRENGTH OF AT LEAST 100,000 POUNDS PER SQUARE INCH AS DETERMINED AFTER CONTACTING A FIBRE HAVING A DIAMETER FROM 0.4 TO 1 .0 X 10**-3 INCH AND A LENGHT OF 2 1/2 INCHES WITH A SATURATED CA (OH)2 SOLUTION FOR 4 HOURS AT 100*C., REMOVING THE FIBRE FROM THE SOLUTION AND WASHING THE FIBRE IN SEQUENCE WITH A DILUTE SOLUTION OF AQUEOUS HC1, WATER, AND ACETONE, AND DRYING, THE FIBRE EXPERIENCING NOT MORE THAN 10* REDUCTION IN DIAMETER DURING SAID TEST.
Claim 2
Dependent Claim 129 words
AN ALKALI-RESISTANT GLASS FIBRE DERIVED FROM A GLASS CONSISTING ESSENTIALLY OF, IN PERCENT BY WEIGHT, 65-80% SIO2, 10-20% ZRO2, AND 10-20% OF AT LEAST ONE NETWORK MODIFIER WHICH IS AN ALKALI METAL OXIDE, AN ALKALINE EARTH METAL OXIDE, OR ZNO, SAID GLASS BEING ONE WHICH HAS A TENSILE STRENGTH OF AT LEAST 100,000 POUNDS PER SQUARE INCH AS DETERMINED AFTER CONTACTING A FIBRE HAVING A DIAMETER FROM 0.4 TO 1 .0 X 10**-3 INCH AND A LENGHT OF 2 1/2 INCHES WITH A SATURATED CA (OH)2 SOLUTION FOR 4 HOURS AT 100*C., REMOVING THE FIBRE FROM THE SOLUTION AND WASHING THE FIBRE IN SEQUENCE WITH A DILUTE SOLUTION OF AQUEOUS HC1, WATER, AND ACETONE, AND DRYING, THE FIBRE EXPERIENCING NOT MORE THAN 10* REDUCTION IN DIAMETER DURING SAID TEST.
Claim 3
Dependent Claim 31 words
A fibre according to claim 1, wherein the glass contains up to 10% by weight of at least one fluxing agent selected from the group consisting of CaF2, P2O5 and MnO.
Claim 4
Dependent Claim 10 words
A fibre according to claim 1, containing Na2O and Li2O.
Claim 5
Dependent Claim 17 words
A fibre according to claim 1, wherein the ZrO2 content of the glass is 15-16% by weight.
Claim 6
Dependent Claim 21 words
A fibre according to claim 1, wherein the glass contains about 71% SiO2, 16% ZrO2, 11% Na2O, 1% Li2O, 1% Al2O3.
Claim 7
Dependent Claim 15 words
A fibre according to claim 1, wherein the network modifier is an alkali metal oxide.

References Cited (Backward Citations)

US2566134A Cited
US2640784A Cited
US3007806A Cited
US3485702A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-08-25 1979-02-24 1979-08-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-08-25 1983-02-24 1983-08-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-08-25 1987-02-24 1987-08-26 $7700.00 Window Closed / Lapsed

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