Appeal No. 2001-0772
Application No. 09/052,429
(2) Claims 6 and 7 are rejected under 35 U.S.C. § 103(a) as unpatentable over the
combined teachings of Unger, Rubber Technology, Kotani and Alia.
Discussion
(1) Rejection of claims 1-5
Unger discloses a method for continuously preparing thermo-crosslinkable and/or
thermoplastic elastomer blends by mixing the elastomer with plasticizer oil and other additives,
including carbon black. The method comprises the following steps (col. 2, lines 25-43):
(a) continuously premixing the crushed elastomer in an annular zone mixer with
at least part of said plasticizer oil, and optionally with at least part of said
other additives, to form a preblend in which said elastomer is decomposed
and said additives are embedded in the polymer matrix;
and thereafter
(b) completing the mixing of said premix, and optionally of the remainder of said
additives, in a mixing unit working batchwise or continuously.
In the method according to the invention, said annular zone mixer of said first
step (a) has the function of decomposing the elastomer to such an extent that a
mixing with the adjuvants becomes possible. Thus a large part of the total mixing
process is effected in said annular zone mixer, whereas the function of said mixing
unit of said second step (b), for example an internal or Banbury type mixer or mixing
extruder, is reduced to a simple aftermixing.
In Example 4, carbon black is added during the second step of the method (col. 6,
lines 57-64):
The rubber, the plasticizer oil and the other adjuvants were continuously
premixed in an annular zone mixer rotating at 2000 r.p.m. (revolutions per minute).
The resulting blend and the carbon black were then introduced into a kneader which
was working batchwise, for example an internal mixer, or into a mixing extruder
which was working continuously. There, the elastomer blend was completed.
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