Appeal 2007-2910
Application 10/304,881
1 teaches using IPDA and another amine hardener (TETA) in stoichiometric
2 amounts with the epoxy resin.26
3 The Levine patent relates to water-based coating compositions,
4 particularly those with polymer binder emulsions for use as protective
5 coatings and sealers for metal substrates.27 Levine is concerned about
6 adherence of top coats to surfaces previously coated with an alkyd primer.
7 The solution is to use an intermediate coat or sealer.28 Levine proposes
8 improving the known epoxy sealers in the art by using a composition with
9 environmentally benign water as the solvent .29
10 Levine teaches the use of an ethylenically unsaturated monomer as a
11 component of the water-based polymeric binder.30 Vinyl acetate is disclosed
12 as a suitable monomer.31
13 Levine teaches that virtually any epoxy resin may be used, but high
14 molecular weight epoxy resins are preferred, particularly those based on
15 bisphenol A.32 Low molecular weight resins are said to have problems like
16 poor adhesion and difficulty in forming emulsions and compositions.33
17 Nevertheless, Levine specifically teaches the uses of polyglycidyl ethers of
18 bisphenol A as an acceptable low molecular weight epoxy resin.34
26 Robeson 9:41-10:25; TABLE 7.
27 Levine 1:7-20.
28 Levine 1:25-37.
29 Levine 2:1-9.
30 Levine 2:12-23.
31 Levine 3:5-18.
32 Levine 3:55-4:39.
33 Levine 4:40-54.
34 Levine 5:6-8.
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