Glass fibers decomposable in a physiological medium
AssigneeIsover Saint-Gobain
InventorsIsabelle Cohen, Sylvie Thelohan, Hans Furtak, Hartmut Tiesler
Life of this patent
Estimating the term…
Abstract
Glass compositions useful for forming fibers which are readily able to be degraded in a physiological medium such as that found in a human body. Advantageous compositions formed according to the present invention comprise the following components, set forth in percent by weight: SiO.sub.2 : 57 to 70% Al.sub.2 O.sub.3 : 0 to 5% CaO: 5 to 10% MgO: 0 to 5% Na.sub.2 O+K.sub.2 O: 13 to 18% B.sub.2 O.sub.3 : 2 to 12% F: 0 to 1.5% P.sub.2 O.sub.5 : 0 to 4% Impurities: less than 2%
Claims5
Glass fiber which is decomposable in a physiological medium, said fiber comprising:
- SiO.sub.2 :
- 57 to 70 wt %;
- CaO:
- 5 to 10 wt %;
- Na.sub.2 O+K.sub.2 O:
- 13 to 18 wt %;
- B.sub.2 O.sub.3 :
- 2 to 12 wt %;
- Al.sub.2 O.sub.3 :
- up to about 5 wt %;
- MgO:
- up to about 5 wt %;
- F:
- up to about 1.5 wt %;
- Impurities:
- less than 2 wt %;
- and
- P.sub.2 O.sub.5 in an amount effective in combination with the B.sub.2 O.sub.3 and, when present, the Al.sub.2 O.sub.3, but less than about 4 wt. %, to cause the fiber to be decomposable in a physiological midi;
- wherein said fiber contains more than 0.1% by weight of P.sub.2 O.sub.5 when the percentage by weight of alumina is greater than or equal to about 1%.
Glass fiber which is decomposable in a physiological medium, said fiber comprising:
- SiO.sub.2 :
- 59 to 68 wt %;
- CaO:
- 6 to 9 wt %;
- MgO:
- 2 to 4 wt %;
- Na.sub.2 O:
- 14 to 17 wt %;
- Al.sub.2 O.sub.3 :
- up to about 3 wt %;
- K.sub.2 O:
- up to about 2 wt %;
- F:
- up to about 1.5 wt %;
- B.sub.2 O.sub.3 :
- 4 to 11 wt %;
- and
- P.sub.2 O.sub.5 in an amount effective in combination with the B.sub.2 O.sub.3 and, when present, the Al.sub.2 O.sub.3 but less than about 4 wt., % to cause the fiber to be decomposable in a physiological medium, wherein said fiber contains more than 0.1% by weight of P.sub.2 O.sub.5 when the percentage by weight of alumina is greater than or equal to about 1%.
Glass fiber decomposable in a physiological medium, said fiber comprising:
- SiO.sub.2 :
- 60 to 68 wt %;
- Al.sub.2 O.sub.3 :
- 1 to 5 wt %;
- CaO:
- 6 to 9 wt %;
- MgO:
- 2 to 4 wt %;
- Na.sub.2 O:
- 14 to 17 wt %;
- B.sub.2 O.sub.3 :
- 4 to 11 wt %;
- P.sub.2 O.sub.5 :
- 0.5 to 4 wt %;
- K.sub.2 O:
- up to about 2 wt %;
- and
- F:
- up to about 1.5 wt %;
- wherein the amounts of P.sub.2 O.sub.5, B.sub.2 O.sub.3 and Al.sub.2 O.sub.3 are effective to cause the fiber to be decomposable in a physiological medium.
Dependencies are inferred from the claim text.