EP0186077A2
Expired / Lapsed
EP
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Low boron glass fibers with low index of refraction
Assignee: PPG Industries Inc
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Filing: 1985-12-13
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Granted: —
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Expires: 2005-12-13
Abstract
Abstract 57 Reduced boron containing glass fibers are provided which have a refractive index similar to that of higher boron-containing glass fiber compositions. The glass fibers with a refractive index in the range of greater than 1.5495 to around 1.57 have in weight percent Si0 2 - 55-56.5, CaO 20-23, Al 2 O 3 14.5-15.5, B 2 O 3 - 5 to 5.8, R 2 0 - 1-1.5, wherein R is an alkali metal and F 2 - 0.4 to 0.6. In addition, the glass fiber composition can have minor constituents such as Ti0 2 of up to around 0.6 weight percent and an MgO of up to around 0.3 weight percent and ferric oxide of up to around 0.3 weight percent. Basically, the glass fibers have a reduced content of both B 2 0 3 and CaO over standard glass fiber compositions such as E-glass and 621-glass and also has elevated amounts of alkali and of refractory constituents such as Si0 2 and Al 2 O 3 . The glass fibers are formed with an elevated temperature of 40 to 50°F (22-28°C) above the temperature used to form glass fibers from E-glass and 621-glass.
Inventors
- 👤 James Francis Sproull
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 15:30
CPC Classifications
C; C03; C03C; C03C13/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
122 words
A glass fiber comprised of SiO 2 , CaO; B 2 O 3 ; R 2 O, where R is an alkali metal, and F 2 characterized in that the fiber has a reduced boron content while having a refractive index in the range of greater than 1.5495 up to 1.557 by having in weight percent: 55 to 56.5 SiO 2 ; 14.5 to 15.5 Al 2 O 3 ; 20 to 23 CaO; 5 to 5.8 weight percent B 2 0 3 ; 1 to 1.4 R 2 0, where R is an alkali metal, and 0.4 to 0.6 weight percent F 2 and having a high temperature viscosity log n (°F) 2.0 to 5.0 of 2576 (1413°C) to 1818 (992°C).
Claim 2
Dependent Claim
122 words
A glass fiber comprised of SiO 2 , CaO; B 2 O 3 ; R 2 O, where R is an alkali metal, and F 2 characterized in that the fiber has a reduced boron content while having a refractive index in the range of greater than 1.5495 up to 1.557 by having in weight percent: 55 to 56.5 SiO 2 ; 14.5 to 15.5 Al 2 O 3 ; 20 to 23 CaO; 5 to 5.8 weight percent B 2 0 3 ; 1 to 1.4 R 2 0, where R is an alkali metal, and 0.4 to 0.6 weight percent F 2 and having a high temperature viscosity log n (°F) 2.0 to 5.0 of 2576 (1413°C) to 1818 (992°C).
Claim 3
Dependent Claim
40 words
Glass fiber composition of Claim 1, which includes in weight percent one or more of the compounds selected from the group consisting of up to 0.6 percent TiO 2 , and up to 0.3 MgO, and up to 0.3 Fe203.
Claim 4
Dependent Claim
18 words
Glass fiber composition of Claims 1-2, wherein the refractive index is in the range of 1.553 to 1.557.
Claim 5
Dependent Claim
35 words
Glass fiber composition of Claims 1-3, wherein the following components are present in the following weight percentage amounts: silica 55.8, calcium oxide 21, aluminum oxide 14.8, boric oxide 5.2, sodium oxide 1.4 and fluorine 0.5.
Claim 6
Dependent Claim
220 words
Process of preparing the glass fibers comprised of Si0 2 ; Al 2 O 3 ; C aO; B 2 O 3 ; R 2 O, where R is an alkali metal, and F 2 characterized in that the fibers have a reduced boron content, while having a refractive index in the range of greater than 1.5495 up to 1.557, by: a. formulating a glass fiber forming composition to produce glass fibers from molten streams of glass, wherein the glass has a decreased amount of B 2 O 3 in the range of 5 to 5.8 weight percent and a decreased amount of calcium oxide in the range of 20-23 weight percent and an increased amount of refractive constituents including Si0 2 in the range of 55 to 56.5 weight percent and A1 2 0 3 in the range of 14.5 to 15.5 weight percent, and increasing the amount of R 2 0 in the range of 1 to 1.5 and having an amount of fluorine in the range of 0.4 to 0.6; and b. forming the glass fibers with an increased temperature around 40 to 50°F (22°C to 28°C) in the range of 2576°F (1413°C) to 2218°F (1214°C) for log viscosity of 2.0 to 3.0 from orifices in a glass fiber producing means, and c. attenuating the glass fibers.
Claim 7
Dependent Claim
220 words
Process of preparing the glass fibers comprised of Si0 2 ; Al 2 O 3 ; C aO; B 2 O 3 ; R 2 O, where R is an alkali metal, and F 2 characterized in that the fibers have a reduced boron content, while having a refractive index in the range of greater than 1.5495 up to 1.557, by: a. formulating a glass fiber forming composition to produce glass fibers from molten streams of glass, wherein the glass has a decreased amount of B 2 O 3 in the range of 5 to 5.8 weight percent and a decreased amount of calcium oxide in the range of 20-23 weight percent and an increased amount of refractive constituents including Si0 2 in the range of 55 to 56.5 weight percent and A1 2 0 3 in the range of 14.5 to 15.5 weight percent, and increasing the amount of R 2 0 in the range of 1 to 1.5 and having an amount of fluorine in the range of 0.4 to 0.6; and b. forming the glass fibers with an increased temperature around 40 to 50°F (22°C to 28°C) in the range of 2576°F (1413°C) to 2218°F (1214°C) for log viscosity of 2.0 to 3.0 from orifices in a glass fiber producing means, and c. attenuating the glass fibers.
Claim 8
Dependent Claim
44 words
Process of Claim 5, wherein the glass fiber composition includes in weight percent one or more of the compounds selected from the group consisting of: up to 0.6 TiO 2 , up to 0.3 MgO and up to 0.3 Fe 2 O 3 .
Claim 9
Dependent Claim
16 words
Process of Claims 5-6, wherein the refractive index is in the range of 1.553 to 1.557.
Claim 10
Dependent Claim
33 words
Process of Claims 5-7, wherein the following components are present in the following weight percentage amounts: silica 55.8, calcium oxide 21, aluminum oxide 14.8, boric oxide 5.2, sodium oxide 1.4 and fluorine 0.5.
Claim 11
Dependent Claim
6 words
Glass fiber product of Claims 5-8.
Claim 12
Dependent Claim
25 words
Process of Claims 5-8, which includes treating the glass fibers with an aqueous chemical treating composition, and gathering the fibers into one or more strands.
Claim 13
Dependent Claim
29 words
Process of Claim 10, which includes further processing by: chopping the gathered strands, and collecting the chopped strands; or collecting the strands on a winder into a multilayered package.
Claim 14
Dependent Claim
17 words
Process of Claim 13, which includes drying the packages of ;lass fiber strands at an elevated temperature.
References Cited (Backward Citations)
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