Appeal No. 2006-2662
Application No. 09/928,764
in water. (Specification 2.) The specification also describes using the
dispersion to form a film. (Id.)
The specification describes preparing the prepolymer from a
“formulation including a diisocyanate and an active hydrogen containing
material.” (Id. at 3.) An active hydrogen containing material can be, e.g., a
diol. (Id. at 5.)
“Preferably, the diisocyanate is an aromatic diisocyanate selected
from the group consisting of MDI [methylene diphenyldiisocyanate], TDI
[toluene diisocyanate] and mixtures thereof.” (Id. at 4.) When MDI is used,
“it preferably has a P,P’ isomer content of from about 99 percent to about 90
percent.” (Id. at 5.) “While MDI with such isomer distributions can be
prepared by distillation during the MDI process, it can also be prepared by
admixing commonly available products such as ISONATE 125M* and
ISONATE 500P*.” (Id.)
DISCUSSION
1. CLAIM CONSTRUCTION
Claims 1, 5, 7-9, 11, 12, 24, 25, and 27-41 are pending and on appeal.
We will focus on claim 24, which is representative and reads as follows:
24. An aqueous polyurethane dispersion, comprising the product of
dispersion in water a nonionic polyurethane prepolymer prepared from a
prepolymer formulation including an MDI diisocyanate, the MDI having a
P,P’- isomer content from 99 to 90 percent wherein the dispersion is formed
in a two or more step process wherein:
(1) in a first step the prepolymer is formed and, in a subsequent step,
(2) an aqueous dispersion of the prepolymer is formed.
2
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