Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From phenol – phenol ether – or inorganic phenolate
Reexamination Certificate
2000-12-20
2002-08-13
Boykin, Terressa M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From phenol, phenol ether, or inorganic phenolate
C528S198000
Reexamination Certificate
active
06433127
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to copolyestercarbonates, and more particularly to polyestercarbonates containing a novel ester-derived unit.
Copolyestercarbonates may be prepared by the interfacially conducted condensation of dihydroxyaromatic compounds with dicarboxylic acids and phosgene in an immiscible aqueous-organic medium. The reaction ordinarily takes place in the presence of a tertiary amine, a phase transfer catalyst or both. They may also be prepared by a transesterification reaction between a diaryl carbonate such as diphenyl carbonate and a mixture of at least one dihydroxyaromatic compound and at least one aryl ester of a dicarboxylic acid. The product copolyestercarbonates have properties similar to those of polycarbonates but are generally more ductile, especially when the ester units are “soft block” units derived from aliphatic acids.
A class of widely used commercially available copolyestercarbonates comprises carbonate structural units derived from 2,2-bis(4-hydroxyphenyl)propane, hereinafter “bisphenol A”, and ester units derived from a dicarboxylic acid containing at least 10 carbon atoms, particularly dodecanedioic acid (hereinafter “DDDA”). In order to effect complete incorporation of ester units in the copolymer, it is typically necessary to maintain the pH of an interfacial reaction mixture in the range of about 8.0-8.5 while dicarboxylic acid monomer is present therein. After all the acid has been incorporated, the pH is typically increased to a value in the range of about 9.0-10.5. The higher pH permits better pH control and minimizes the occurrence of such problems as phosgene buildup in the reactor and production of carbon dioxide by hydrolysis of carbonate salts, which can result in pressure buildup in the reactor.
For simplicity of operation, it would be desirable to employ a dicarboxylic acid which could be fully incorporated in the copolyestercarbonate at the same pH advantageously employed for incorporation of carbonate units; i.e., one in the range of about 9.0-10.5. This would permit conversion of a homopolycarbonate production system to copolyestercarbonate production with little or no change in procedure.
It is also sometimes found that the use of DDDA affords a polymer which is difficult to isolate, as by precipitation. The particles tend to stick together, forming lumps and making precipitation very cumbersome and complicated. This is particularly true at low molecular weights; for example, at weight average molecular weights (determined, for the most part, by gel permeation chromatography) below about 20,000.
Polymer mixtures comprising conventional polycarbonates or copolyestercarbonates and various branched dimeric fatty acid-derived polyesters are disclosed in U.S. Pat. No. 5,635,560. However, the fatty acid precursors therefor are described as containing phenolic OH groups. Moreover, there is no disclosure of copolyestercarbonates containing units derived from such fatty acids.
SUMMARY OF THE INVENTION
The present invention provides copolyestercarbonates having excellent physical properties. Said copolyestercarbonates may be produced by a relatively simple interfacial polymerization method, at a pH level within a single range for the entire reaction. The resulting copolyestercarbonates have properties which are equal to or, at certain molecular weight levels, superior to those of corresponding polymers prepared using DDDA.
One aspect of the invention is copolyestercarbonates comprising carbonate structural units of the formula
wherein each A
1
is independently a divalent aliphatic, alicyclic or aromatic radical, and ester units derived from a dihydroxyaromatic compound of the formula A
1
(OH)
2
and a composition comprising at least one C
36
dimer acid.
Another aspect of the invention is a method for preparing a copolyestercarbonate which comprises passing phosgene through a mixture, in a two-phase aqueous-organic medium, of at least one dihydroxyaromatic composition comprising at least one C
36
dimer acid and at least one aliphatic tertiary amine, or phase transfer catalyst or mixture thereof, while maintaining the pH of the aqueous phase of said mixture in the range of about 9-11 by addition of aqueous alkali as necessary.
DETAILED DESCRIPTION; PREFERRED EMBODIMENTS
The copolyestercarbonates of the invention are characterized in part by the presence of carbonate structural units of formula I, in which A
1
may be a divalent aliphatic, alicyclic or aromatic radical or a mixture thereof. It is most often an aromatic radical, which may be an aromatic hydrocarbon or a substituted aromatic hydrocarbon radical, with illustrative substituents being alkyl, cycloalkyl, alkenyl (e.g., crosslinkable-graftable moieties such as allyl), halo (especially fluoro, chloro and/or bromo), nitro and alkoxy.
The preferred A
1
values have the formula
—A
2
—Y—A
3
—, (II)
wherein each of A
2
and A
3
is a monocyclic divalent aromatic radical and Y is a single bond or a bridging radical in which one or two atoms separate A
2
from A
3
. The free valence bonds in formula II are usually in the meta or para positions of A
2
and A
3
in relation to Y.
In formula II, the A
2
and A
3
values may be unsubstituted phenylene or substituted derivatives thereof wherein the substituents are as defined for A
1
. Unsubstituted phenylene radicals are preferred, but it is also contemplated to employ, for example, polymers in which each of A
2
and A
3
has two methyl substituents in ortho positions to the free valence bond. Both A
2
and A
3
are preferably p-phenylene, although both may be o- or m-phenylene or one o- or m-phenylene and the other p-phenylene.
The bridging radical, Y, is one in which one or two atoms, preferably one, separate A
2
from A
3
. It is most often a hydrocarbon radical and particularly a saturated C
1
-
2
aliphatic or alicyclic radical. Illustrative radicals are methylene, cyclohexylmethylene, [2.2.1]bicycloheptylmethylene, ethylene, ethylidene, 2,2-propylidene, 1,1-(2,2-dimethylpropylidene), phenylethylidene, cyclohexylidene, 3,3,5-trimethylcyclohexylidene, cyclopentadecylidene, cyclododecylidene, 9,9-fluorenylidene and 2,2-adamantylidene, especially an alkylidene radical. Aryl-substituted radicals are included, as are unsaturated radicals and radicals containing atoms other than carbon and hydrogen; e.g., oxy groups. Substituents such as those previously enumerated may be present on the aliphatic, alicyclic and aromatic portions of the Y group.
For most purposes, the preferred units containing moieties of formula II are those in which each of A
2
and A
3
is p-phenylene and Y is isopropylidene; i.e., those derived from bisphenol A. Such units may be present in combination with other units of formula II or formula I.
Also present in the copolyestercarbonates of this invention are ester units derived from a dihydroxyaromatic compound of the formula A
1
(OH)
2
and a composition comprising at least one C
36
dimer acid. Dimer acid compositions are known in the art; reference is made, for example, to
Kirk
-
Othmer Encyclopedia of Chemical Technology
, Fourth Edition, 8, 223. They typically comprise principally dimers of C
8
unsaturated fatty acids such as oleic acid (cis-9-octadecenoic acid), elaidic acid (trans-9-octadecenoic acid), linoleic acid (cis-9-cis-12-octadecadienoic acid) or mixtures thereof, particularly naturally occurring mixtures such as tall oil fatty acids. The use of hydrogenated dimer acids is within the scope of the invention, and is often preferred.
The molecular structures of the acids present in dimer acid compositions (non-hydrogenated and hydrogenated) vary with the starting materials employed. They may include the following and their hydrogenated analogs:
Use of any dimer acid compositions comprising compounds of formulas III-IX or their hydrogenated analogs is particularly contemplated as part of the invention. Dimer acids are also identified by the CAS registry numbers 61788-89-4 and 68783-41-5, and any composition to which these numbers apply is useful according t
Davis Gary Charles
Mobley David Paul
Nelson Mark Erik
Boykin Terressa M.
Brown S. Bruce
General Electric Company
Johnson Noreen C.
LandOfFree
Copolyestercarbonates derived from dimer acids and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Copolyestercarbonates derived from dimer acids and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Copolyestercarbonates derived from dimer acids and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2936826