Fiber composite
View Patent ↗To provide a cellulose fiber composite having high transparency, low water absorption and low coefficient of linear thermal expansion. A fiber composite which comprises fibers having an average fiber diameter of at most 30 nm and a matrix material and which has a haze of at most 5 according to JIS K-7136 when the fiber composite has a thickness of 100 μm.
1. A fiber composite comprising:
fibers having an average fiber diameter of at most 30 nm, and
a matrix material,
wherein said fiber composite has a haze of at most 5 according to JIS K 7136 when the fiber composite has a thickness of 100 μm, and
wherein said fiber composite has a yellowness index of at most 20 according to JIS K7105 after the fiber composite, having a thickness of 100 μm, is heated at 190° C. under an oxygen partial pressure of at most 0.006 MPa for 1 hour.
2. The fiber composite according to claim 1 , wherein the fibers are cellulose.
3. The fiber composite according to claim 1 , wherein the fibers are chemically modified.
4. The fiber composite according to claim 1 , which has a coefficient of linear thermal expansion of at least 1 ppm/K and at most 50 ppm/K.
5. The fiber composite according to claim 1 , wherein the matrix material is a polymer material.
6. The fiber composite according to claim 1 , which has a thickness of at least 10 μm and at most 10 cm.
7. A process for producing the fiber composite as defined in claim 1 , comprising:
microfibrillating fibers by an ultrahigh-pressure homogenizer to reduce the pressure by letting the fibers jet from a pressure of at least 100 MPa and/or by ultrasonic waves having a frequency of at least 15 kHz and at most 1 MHz and an effective power density of at least 1 W/cm 2 , to obtain the fibers having an average fiber diameter of at most 30 nm; and
combining the fibers having an average fiber diameter of at most 30 nm and the matrix material.
8. A substrate comprising the fiber composite as defined in claim 1 .
9. A window material comprising the fiber composite as defined in claim 1 .
10. A fiber composite comprising:
fibers having an average fiber diameter of at most 30 nm, and
a matrix material,
wherein said fiber composite has a haze of at most 5 according to JIS K 7136 when the fiber composite has a thickness of 100 μm, and
wherein said fiber composite has a water absorption of at most 1% according to JIS K7209 (method D) when the fiber composite has a thickness of 100 μm.
11. The fiber composite according to claim 10 , which has a coefficient of linear thermal expansion of at least 1 ppm/K and at most 50 ppm/K.
12. The fiber composite according to claim 10 , wherein the fibers are cellulose.
13. The fiber composite according to claim 10 , wherein the fibers are chemically modified.
14. The fiber composite according to claim 10 , wherein the matrix material is a polymer material.
15. The fiber composite according to claim 10 , which has a thickness of at least 10 μm and at most 10 cm.
16. A process for producing the fiber composite as defined in claim 10 , comprising:
microfibrillating fibers by an ultrahigh-pressure homogenizer to reduce the pressure by letting the fibers jet from a pressure of at least 100 MPa and/or by ultrasonic waves having a frequency of at least 15 kHz and at most 1 MHz and an effective power density of at least 1 W/cm 2 , to obtain the fibers having an average fiber diameter of at most 30 nm; and
combining the fibers having an average fiber diameter of at most 30 nm and the matrix material.
17. A substrate comprising the fiber composite as defined in claim 10 .
18. A window material comprising the fiber composite as defined in claim 10 .