Appeal No. 1996-3493
Application No. 08/451,697
calcination, generally from 400EC to 600EC (col. 8, lines 28-36). Modified zeolites are generally
calcined at various temperatures between 300EC to 800EC for 2 to 24 hours, depending upon the
element used to treat the zeolite (col. 12, lines 15-18; col. 13, lines 10-12 and 32-35). The zeolite
catalyst may also be combined with matrix materials, e.g., clays, silica and/or metal oxides, which are
resistant to the temperature or other conditions of a DMA production process (col. 17, lines 39-44).
Abrams discloses that calcining an acidic zeolite rho catalyst at a temperature of about 475EC
to about 825EC in the presence of steam provides a catalyst with higher activity and higher selectivity
for DMA (col. 4, lines 32-35 and 53-59). The catalyst may also be combined with matrix materials,
e.g., clays, silica, alumina, and other metal oxides, which are resistant to the temperature or other
conditions of a process for producing DMA (col. 13, lines 7-12; abstract).
Beck discloses combining acidic porous crystalline materials with matrix materials, e.g., clays,
silica and/or metal oxides, which are resistant to temperature and other conditions employed in organic
conversion processes (col. 4, lines 36-42). Zeolites are frequently combined with clays, e.g., bentonite
and kaolin, which function, in part, as a binder (col. 4, lines 52-56). Porous matrix materials, e.g.,
silica, alumina, zirconia, titania, silica-alumina, silica-magnesia, silica-thoria, silica-berylia, silica-titania,
silica-alumina-zirconia, silica-alumina-magnesia, and silica-magnesia-zircona, can also be used (col. 5,
lines 3-10). Silica is preferred because of its relative inertness for acid-catalyzed reactions (col. 5, lines
13- 16). The relative proportions of the acidic porous crystalline material and inorganic oxide matrix
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