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Abstract
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Provided
are compounds of the following: wherein R1 is a saturated or unsaturated
cyclic hydrocarbon optionally substituted with an alkyl and/or an OXO-ester,
and R2 is the residue of a C4 to C14 OXO-alcohol. Also provided are processes
for making the compounds and plasticized polymer compositions containing said
compounds.
BACKGROUND Plasticizers are incorporated into a resin (usually a
plastic or elastomer) to increase the flexibility, workability, or
distensibility of the resin. The largest use of plasticizers is in the
production of “plasticized” or flexible polyvinyl chloride (PVC) products.
Typical uses of plasticized PVC include films, sheets, tubing, coated
fabrics, wire and cable insulation and jacketing, toys, flooring materials
such as vinyl sheet flooring or vinyl floor tiles, adhesives, sealants, inks,
and medical products such as blood bags and tubing, and the like. Other
polymer systems that use small amounts of plasticizers include polyvinyl
butyral, acrylic polymers, nylon, polyolefins, polyurethanes, and certain
fluoroplastics. Plasticizers can also be used with rubber (although often
these materials fall under the definition of extenders for rubber rather than
plasticizers). A listing of the major plasticizers and their compatibilities
with different polymer systems is provided in “Plasticizers,” A. D. Godwin,
in Applied Polymer Science 21st Century, edited by C. D. Craver and C. E.
Carraher, Elsevier (2000); pp. 157-175. Plasticizers can be characterized on
the basis of their chemical structure. The most important chemical class of
plasticizers is phthalic acid esters, which accounted for 85% worldwide of
PVC plasticizer usage in 2002. However, in the recent past there has been an
effort to decrease the use of phthalate esters as plasticizers in PVC,
particularly in end uses where the product contacts food, such as bottle cap
liners and sealants, medical and food films, or for medical examination
gloves, blood bags, and IV delivery systems, flexible tubing, or for toys,
and the like. For these and most other uses of plasticized polymer systems,
however, a successful substitute for phthalate esters has heretofore not
materialized. One such suggested substitute for phthalates are esters based
on cyclohexanoic acid. In the late 1990's and early 2000's, various
compositions based on cyclohexanoate, cyclohexanedioates, and
cyclohexanepolyoate esters were said to be useful for a range of goods from
semi-rigid to highly flexible materials. See, for instance, WO 99/32427, WO
2004/046078, WO 2003/029339, WO 2004/046078, U.S. Application No.
2006-0247461, and U.S. Pat. No. 7,297,738. Other suggested substitutes
include esters based on benzoic acid (see, for instance, U.S. Pat. No.
6,740,254, and also co-pending, commonly-assigned, U.S. Provisional Patent
Application No. 61/040,480, filed Mar. 28, 2008 and polyketones, such as
described in U.S. Pat. No. 6,777,514; and also co-pending, commonly-assigned,
U.S. Patent Publication No. 2008/0242895, filed Mar. 28, 2008. Epoxidized
soybean oil, which has much longer alkyl groups (C16 to C18) has been tried
as a plasticizer, but is generally used as a PVC stabilizer. Stabilizers are
used in much lower concentrations than plasticizers. Copending and commonly
assigned U.S. Provisional Patent Application No. 61/203,626, filed Dec. 24,
2008, discloses triglycerides with a total carbon number of the triester
groups between 20 and 25, produced by esterification of glycerol with a
combination of acids derived from the hydroformylation and subsequent
oxidation of C3 to C9 olefins, having excellent compatibility with a wide
variety of resins U.S. Pat. No. 2,520,084 to Dazzi discloses plasticized
vinyl chloride polymers using esters of phenyl benzoic acids and aliphatic
hydrocarbon alcohols as plasticizers. Suitable esters are 2-ethylhexyl
m-phenylbenzoate, the corresponding para- and ortho-phenylbenzoates, or
mixtures thereof, and the various phenylbenzoates of n-hexyl, 2-methylheptyl,
dodecyl, dimethylheptyl, 2-butoxyethyl, and isooctyl alcohols, and other
homologous straight and branched alcohols having 8 to 14 atoms. The
butoxyethyl and 2-ethylhexyl esters of phenylbenzoic acid are exemplified.
“Esters of diphenic acid and their plasticizing properties”, Kulev et al.
Izvestiya Tomskogo Politekhnicheskogo Instituta (1961) 111, discloses
diisoamyl diphenate, bis(2-ethylhexyl diphenate and mixed heptyl, octyl and
nonyl diphenates, prepared by esterification of diphenic acid, useful as
plasticizers for vinyl chloride. “Synthesis of dialkyl diphenates and their
properties”, Shioda et al., Yuki Gosei Kagaku Kyokaishi (1959), 17, discloses
dialkyl diphenates of C1 to C8 alcohols, useful as plasticizers for
poly(vinyl chloride) formed by converting diphenic acid to diphenic anhydride
and esterifying the diphenic anhydride, necessarily resulting in
2,2′-substituted diesters of diphenic anhydride. Thus what is needed is a
method of making a general purpose non-phthalate plasticizer having suitable
melting or chemical and thermal stability, pour point, glass transition,
increased compatibility, good performance and low temperature properties.
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