Appeal No. 2005-0020 Page 2
Application No. 09/572,225
INTRODUCTION
The invention relates to a process for the continuous preparation of thermoplastically
processable polyurethanes in a tubular mixer (stirred tubular reactor)(specification, p. 1, ll. 4-5
and p. 2, ll. 22-24). In the process, specified reactants are reacted in a tubular reactor equipped
with a stirrer. The stirrer is a monoaxially rotating stirrer having as mixing elements a member
selected from the group consisting of beams, rods, anchors, grids, blades and propellers.
Claim 1 is illustrative:
1. A continuous process for the preparation of thermoplastic, homogeneous polyurethane
having improved softening properties comprising reacting substantially to completion, in a
tubular reactor equipped with a stirrer at least one diisocyanate (A) with a mixture (B) containing
B1) 1 to 85 equivalent %, based on the isocyanate groups in (A) of at least one compound
having on average at least 1.8 and at most 2.2 Zerewitinoff-active hydrogen atoms per molecule
and a number average molecular weight of 450 to 5000 g/mol, and
B2) 15 to 99 equivalent %, based on the isocyanate groups in (A) of at least one chain
lengthening agent having on average at least 1.8 and at most 2.2 Zerewitinoff-active hydrogen
atoms per molecule and a molecular weight of 60 to 400 g/mol,
wherein (A) and (B) are employed in a NCO:OH ratio of 0.9:1 to 1.1:1, said tubular reactor
characterized in the absence of positively controlled conveyance therefrom and in that the ratio
between the circumferential speed of said stirrer expressed in terms of meter/second and the
throughput expressed in terms of g/second is greater than 0.03 meter/g, said reacting
substantially to completion amounting to conversion greater than 90%, based on starting
component (A) the said absence of positively controlled conveyance restricting said stirrer to a
monoaxially rotating stirrer having as mixing elements a member selected from the group
consisting of beams, rods, anchors, grids, blades and propellers.
Claims 1-9 stand rejected under 35 U.S.C. § 112, ¶ 1 as lacking written descriptive
support in the specification. Specifically, the Examiner concludes that there is no support in the
original specification for “the said absence of positively controlled conveyance restricting said
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