Appeal No. 1998-1728
Application 08/397,243
range is required by Satou and used in Satou Example 1 (col. 13, lines 62-65; col. 16, line 10); (4)
there are different mixing procedures used in the specification Examples and Comparative Examples
without assurance that a uniform mixture of the metal and silicon grains is obtained in the Comparative
Examples, and Satou requires mixing “to obtain a uniform mixture” (col. 13, lines 64-65); and (5)
Satou discloses that the powder mixture is heated to reduce the content of oxygen and other
contaminates and uses this step in preparing Satou Example 1 (col. 14, lines 1-54, col. 16, lines 18-21
and Table 1), while deoxidation prior to silicide synthesis is not used in the processes of the specification
Examples and Comparative Examples.6
The differences in silicide synthesis, sintering and densification include: (6) Satou conducts the
silicide synthesis with the deoxidized powder mixture at a temperature of 1,000° to 1,300°C, depending
on the silicide synthesis temperature of the metal, at less than 20° C/minute and a desirable pressure of
from 100 to 400 kg/cm2, as exemplified by Satou Example 1 (col. 14, line 55, to col. 15, line 27, col.
16, lines 22-23, and Table 1),7 while the processes of the specification Examples and Comparative
Examples heat the powder mixture up to 1300°C with different heating schedules and use different
vessels in doing so (pages 36 and 38);8 (7) while it would appear that the silicide material is “crushed”
in the Comparative Examples (specification, page 38, line 11) as in the Examples, the same is not
6 The specification discloses that the temperature used in the silicide synthesis is determined “taking the
reduction of the oxygen content into consideration” (paragraph bridging pages 23-24) and that an
optional deoxidizing step can be used in connection with the “crushed powder” step following silicide
synthesis (e.g., pages 26-27).
7 Satou teaches that
the degassed mixed powder is heated under a high vacuum, and high pressure is applied to
synthesize the [metal silicide] phase. In this silicide synthesis step, the heating temperature
and the applied pressure must be set at appropriate values so that the silicide reaction
progresses gradually, [metal silicide] grain growth is suppressed, and softened [silicon] flows
into the gaps between the [metal silicide] grains. [Col. 14, lines 55-62.]
8 The specification teaches that the synthesis is conducted at up to 1300°C at different heating
schedules (see supra note 6) without the application of pressure (pages 20-25). We interpret allowed
claim 6 to encompass processes wherein step “II” would include the application of pressure in view of
the transitional term “comprising.” See generally, In re Baxter, 656 F.2d 679, 686-87, 210 USPQ
795, 802-03 (CCPA 1981) (“As long as one of the monomers in the reaction is propylene, any other
- 10 -
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007