Claims
- 1. A neutron absorbent including a composite material mainly composed of carbon and boron, said composite material being obtained by impregnating a carbon material with a boron oxide and/or a hydrate compound thereof; baking such carbon material under pressure by inert gas at a temperature not lower than 1500.degree. C., wherein the total amount of mineral impurities other than boron composite is not larger than 20 ppm and the amount of residual free B.sub.2 O.sub.3 is not larger than 0.1% by weight.
- 2. A neutron absorbent as set forth in claim 1, wherein said carbon material is a high density isotropic graphite material.
- 3. A neutron absorbent as set forth in claim 1, wherein said carbon material is a carbon-carbon composite material reinforced by carbon fibers.
- 4. A neutron absorbent as set forth in claim 1, wherein said impregnating is conducted at a temperature of 600.degree.-1400.degree. C. and a pressure of at least 50 kg/cm.sup.2.
- 5. A neutron absorbent as set forth in claim 1, wherein said impregnating is conducted at a temperature of 800.degree.-1200.degree. C. and a pressure of 50-100 kg/cm.sup.2.
- 6. A neutron absorbent as set forth in claim 1, wherein the baked material is further treated under a pressure of not higher than 10 Torr and at a temperature of not lower than 1500.degree. C. for a length of time to remove substantially all unreacted boron-containing compound.
Priority Claims (3)
Number |
Date |
Country |
Kind |
203620 |
Jul 1990 |
JPX |
|
212074 |
Aug 1990 |
JPX |
|
413604 |
Dec 1990 |
JPX |
|
Parent Case Info
This application is a division of pending application Ser. No. 08/104,410 filed Aug. 10, 1993, which is a continuation of application Ser. No. 07/729,723 filed Jul. 15, 1991, abandoned.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
4248814 |
Yajima et al. |
Feb 1981 |
|
4313973 |
McMurtry et al. |
Feb 1982 |
|
4524138 |
Schwetz et al. |
Jun 1985 |
|
4718941 |
Halverson et al. |
Jan 1988 |
|
Divisions (1)
|
Number |
Date |
Country |
Parent |
104410 |
Aug 1993 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
729723 |
Jul 1991 |
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