Appeal No. 1999-2808
Application 08/772,351
applications, comprising a polyvinyl chloride resin and a
specified low toxicity stabilizer for that resin. Claim 30 is
illustrative:
30. A composition of matter comprising:
(i) a food contact or medical contact polyvinyl chloride
resin; and
(ii) a low toxicity stabilizer suitable for use with
food contact and medical applications, for providing heat
stability to the polyvinyl chloride resin, wherein the
stabilizer consists essentially of: (a) about 10 to about 40
parts by weight of a zinc carboxylate having the formula
(RCO ) Zn, wherein R is an aliphatic, cycloaliphatic or
22
aromatic hydrocarbon containing from about 6 to about 22
carbon atoms; (b) about 40 to about 80 parts by weight of an
alkyl ester of thiodipropionic acid having the formula
S(CH CH CO R ) wherein R is an alkyl having from about 6 to1
2 2 212 1
about 22 carbon atoms; and (c) about 5 to about 20 parts by
weight of a phenolic antioxidant,
the composition of matter being essentially free of
calcium fatty acid salts.
THE REFERENCES
Ackerman 3,262,896 Jul. 26, 1966
Rhodes 3,575,905 Apr. 20, 1971
Vijlbrief 3,586,514 Jun. 22, 1971
Minagawa et al. (Minagawa) 4,221,700 Sep. 9, 1980
Penneck et al. (Penneck) 1,001,344 Aug. 18, 1965
(Great Britain patent specification)
Jerzy Wypych, “Mechanism of Action of PVC Thermal
Stabilizers”, 23 J. Appl. Polym. Sci. 39-54 (1979).
2
Page: Previous 1 2 3 4 5 6 7 8 9 10 Next
Last modified: November 3, 2007