Glass composition for glass fibers, glass fibers, woven glass fiber fabric, and glass-fiber-reinforced resin composition
A glass composition for glass fibers including 50.0 to 70.0% by mass of SiO 2 , 10.0 to 30.0% by mass of Al 2 O 3 , 8.0 to 25.0% by mass of ZnO, 0.0 to 8.0% by mass of MgO, 0.0 to 5.0% by mass of CaO, 0.0 to 8.0% by mass of P 2 O 5 , 0.0 to 2.5% by mass of TiO 2 , and 0.0% by mass or more and less than 1.0% by mass in total of Li 2 O, Na 2 O, and K 2 O, and when the contents of SiO 2 , Al 2 O 3 , ZnO, MgO, CaO, and P 2 O 5 are defined as S, A, Z, M, C, and P, respectively, (M+C)/Z is 0.46 or less and the S, A, and P satisfy the following formula (1-1): 28.0≤{(S−P)×(A−P)} 1/2 ≤36.9 . . . (1-1).
1. A glass composition for glass fiber comprising:
SiO 2 in a range of 50.0 to 70.0% by mass,
Al 2 O 3 in a range of 10.0 to 30.0% by mass,
ZnO in a range of 8.0 to 25.0% by mass,
MgO in a range of 0.0 to 4.0% by mass,
CaO in a range of 0.0 to 5.0% by mass,
P 2 O 5 in a range of 0.0 to 8.0% by mass,
TiO 2 in a range of 0.0 to 2.5% by mass, and
Li 2 O, Na 2 O, and K 2 O in a range of 0.0% by mass or more and less than 1.0% by mass in total, with respect to the total amount, wherein
when a content of SiO 2 is defined as S, a content of Al 2 O 3 is defined as A, a content of ZnO is defined as Z, a content of MgO is defined as M, a content of CaO is defined as C, and a content of P 2 O 5 is defined as P,
a ratio of the total content of CaO and MgO to the content of ZnO ((M+C)/Z) is 0.46 or less, and
the S, A, and P satisfy following formula (1-1):
28.
≤
{
(
S
-
P
)
×
(
A
-
P
)
}
1
/
2
≤
36.9
.
(
1
-
1
)
2. The glass composition for glass fiber according to claim 1 , wherein the S, A, and P satisfy following formula (1-2):
28.6
≤
{
(
S
-
P
)
×
(
A
-
P
)
}
1
/
2
≤
33.8
.
(
1
-
2
)
3. The glass composition for glass fiber according to claim 1 , wherein the S, A, and P satisfy following formula (2-1):
P
×
{
Z
/
(
Z
+
C
+
M
)
}
×
(
S
/
A
)
≤
10.72
.
(
2
-
1
)
4. The glass composition for glass fiber according to claim 1 , wherein the S, A, Z, M, C, and P satisfy following formulas (1-3) and (2-2):
29.5
≤
{
(
S
-
P
)
×
(
A
-
P
)
}
1
/
2
≤
31.2
(
1
-
3
)
7.15
≤
P
×
{
Z
/
(
Z
+
C
+
M
)
}
×
(
S
/
A
)
≤
10.4
.
(
2
-
2
)
5. The glass composition for glass fiber according to claim 1 , comprising
Al 2 O 3 in a range of 20.5 to 25.0% by mass, and
ZnO, MgO, and CaO in a range of 15.5 to 25.0% by mass in total, with respect to the total amount.
6. Glass fiber formed from the glass composition for glass fiber according to claim 1 .
7. A glass fiber woven fabric formed from the glass fiber according to claim 6 .
8. A glass fiber-reinforced resin composition comprising the glass fiber according to claim 6 .