Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2003-09-02
2004-10-19
Boykin, Terressa (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C521S155000, C524S321000, C528S198000, C528S271000, C528S272000
Reexamination Certificate
active
06806345
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to aliphatic polycarbonate homo- and co-polymers which are obtained by ring-opening homo- or co-polymerization of cyclic carbonates by DMC catalysis.
Double metal cyanide (DMC) catalysts useful for the ring-opening polymerization of oxygen-containing, cyclic monomers have been known for a long time. DMC catalysts are of particular commercial interest for the production of polyether polyols by polyaddition of epoxides to starter compounds exhibiting active hydrogen atoms (See, e.g., U.S. Pat. Nos. 3,404,109; 3,829,505; 3,941,849 and 5,158,922.) because the use of a DMC catalyst reduces the proportion of monofunctional polyethers with terminal double bonds (so-called “mono-ols”) compared to polyether polyols produced using conventional alkaline catalysts. Moreover, improved, highly active DMC catalysts, which are described, e.g., in U.S. Pat. No. 5,470,813; EP-A 700 949; EP-A 743 093; EP-A 761 708; WO 97/40086; WO 98/16310 and WO 00/47649, possess extraordinarily high activity and permit polyether polyol production at very low catalyst concentrations (25 ppm or less). Consequently, it is no longer necessary to separate the catalyst from the finished product. In addition, DMC catalysts also make possible the home and copolymerization of other oxygen-containing, cyclic monomers, such as oxetanes, (U.S. Pat. No. 3,278,457 and 3,404,109), cyclic anhydrides (U.S. Pat. No. 5,145,883 and 3,538,043) and lactones (U.S. Pat. No. 5,032,671).
Aliphatic polycarbonate homo- and co-polymers are suitable as additives for thermoplastic systems. Moreover, aliphatic, OH-functional polycarbonates are widely used as a hydroxyl component for building up polyurethanes and polyurethane-urea elastomers. Common methods for the production of aliphatic polycarbonates are transesterification of a diol with a dialkyl carbonate from a short-chain alcohol, with a dioxolanone or with a diphenyl carbonate. These reactions are accelerated by catalysts, particularly alkali, tin and titanium compounds (See, e.g., Kunststoffhandbuch, vol. 3/1 Polycarbonate, Hanser Verlag, Munich, 1992, p. 118f.).
SUMMARY OF THE INVENTION
It has now been found that aliphatic polycarbonate homo- and co-polymers can be obtained by ring-opening homo- or co-polymerization of a cyclic carbonate by DMC catalysis.
REFERENCES:
patent: 4826887 (1989-05-01), Kuyper et al.
patent: 5115045 (1992-05-01), Gillis et al.
Hofmann Jörg
Schäfer Walter
Steinlein Christian
Bayer Aktiengesellschaft
Boykin Terressa
Gil Joseph C.
Whalen Lyndanne M.
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