Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From carboxylic acid or derivative thereof
Reexamination Certificate
2000-08-15
2001-11-13
Acquah, Samuel A. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From carboxylic acid or derivative thereof
C528S295000, C528S298000, C528S301000, C528S302000, C528S307000, C528S308000, C528S308600, C525S437000, C525S444000
Reexamination Certificate
active
06316586
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a copolyether composition comprising repeat units derived from sulfonated dicarboxylic acid, a process therefor, and a process therewith.
BACKGROUND OF THE INVENTION
Polyesters, especially polyalkylene terephthalates, have excellent physical and chemical properties and have been widely used for resins, films and fibers. For example, polyester fibers have relatively high melting points and can attain high orientation and crystallinity. Accordingly, polyesters have excellent fiber properties such as chemical, heat and light stability, and high strength.
However, polyesters, especially polyester fibers, are difficult to dye. The molecular structure and the high levels of orientation and crystallinity that impart desirable properties to the polyester also contribute to a resistance to coloration by dye compounds. Also contributing to the difficulty in dyeing polyester is the absence in polyesters of ionic dye sites, in contrast to protein fibers, for instance.
In order to make a polyester dyeable by cationic or basic dyes, the polyester must be modified by incorporating dye sites. The most common method to incorporate such sites is polymerization in the presence of either a dimethyl ester or a bis-ethylene glycol ester of 5-sodium sulfoisophthalic acid. The bis-ethylene glycol ester of 5-sulfoisophthalic acid is generally prepared by transesterification of the dimethyl ester of the sodium salt of 5-sulfoisophthalic acid using excess ethylene glycol at 160-250° C. and an ester interchange catalyst. U.S. Pat. Nos. 3,936,389 and 5,607,765 disclose the preparation and utility of bis-ethylene glycol ester of 5-sulfoisophthalic acid in modified polyesters. U.S. Pat. No. 3,936,389 discloses that a mole of the dimethyl ester of a metallo sulfodicarboxylic acid reacts with up to 30 mole equivalents of ethylene glycol, but only 2 moles of the glycol actually react, the remaining glycol acts solely as a solvent for the product. U.S. Pat. No. 3,900,527 discloses the preparation of a bisglycol ester of 5-sulfo isophthalic acid, sodium salt for incorporation into polyesters to improve dyeability and affinity for basic dyes.
U.S. Pat. No. 4,665,153 and JP 10287814 also disclose the preparation of a copolyester by reacting together a dicarboxylic acid, a glycol, a metal sulfonate, and a polyether glycol. The distribution of the monomers in such products is essentially random.
The melt viscosities of the copolyesters are substantially increased as the amount of sulfonate salts rises, resulting in low molecular weight polymers and difficulties in spinning process. It is known that polyether glycols, when used as a block comonomer, yield polyesters with lower melt viscosities and, therefore, can be added along with sulfonate salts during polymerization process to offset the high melt viscosities. Datye, in Colourage, 7-12, February 1994, and Gries et al., in Chemical Fibers International, Vol. 48, 508-513, December 1998, disclose incorporation of additives into polyesters. The polyether glycols are generally obtained by ring opening polymerization of cyclic ethers. The most common polyether glycols that are being used are poly(ethylene glycol), poly(l,2-propylene glycol) and poly(tetramethylene glycol).
It is therefore desirable to develop a composition that can be used to produce ether esters that improve the dyeability of polyesters and a process for producing the composition. An advantage of the invention is that the need to separately make the bis-glycol ester of sulfoisophthalic acid, or salt thereof, and the polyether glycol can be eliminated. Another advantage of the invention is that the preparation of ionic polyether glycols can be carried out in a single step.
SUMMARY OF THE INVENTION
According to a first embodiment of the invention, a copolyether composition that can be used to produce a dyeable polyester is provided. The composition comprises repeat units derived from a first diol and a sulfonated dicarboxylic acid.
According to a second embodiment of the invention, a process that can be used for producing the first composition is provided. The process comprises contacting a first diol with a sulfonated dicarboxylic acid in which the first diol is the same as that disclosed above.
According to a third embodiment of the invention, a process that can be used for producing the copolyester composition is provided. The process comprises contacting, in the presence of a catalyst, the copolyether composition disclosed in the first embodiment of the invention with (1) a second diol and at least one acid or (2) the product derived from a second diol and at least one acid wherein the acid is a dicarboxylic, ester thereof, or combinations thereof.
According to a fourth embodiment of the invention, a copolyester composition is provided that comprises repeat units derived from the copolyether composition, a second diol and at least one acid which is a dicarboxylic, ester, or combinations thereof.
DETAILED DESCRIPTION OF THE INVENTION
The copolyether composition of the first embodiment of the invention is a polymer derived from a sulfonated dicarboxylic acid having the formula of:
H—{[—O—R
1
—]
y
—O—C(O)—A(R
2
)
z
( SO
3
M)—C(O)}
c
—[—O—R
1
]
x
OH (Formula 1)
wherein A is a hydrocarbyl group having about 1 to about 20 carbon atoms per group. The hydrocarbyl group can be (1) a monocyclic or bicyclic aromatic nucleus, or (2) a branched or straight chain, saturated or unsaturated. The hydrocarbyl group can be substituted with one or more R
2
, where R
2
is a C
1
to C
4
alkyl group and z is 0-2, inclusive, except that, when A is aliphatic, z is 0. R
1
is selected from the group comprising a straight chain C
3
or C
6
-C
12
alkylene group, —CH
2
—CH
(2−n)
(CH
3
)
n
—CH
2
—, or —(CH
2
)
3
—O—(CH
2
)
3
—. M is hydrogen, an alkali metal, an alkaline earth metal, quaternary ammonium or phosphonium, or combinations of two or more thereof. Additionally, n is 1 or 2, x and y are each more than 1 and (x+y) is 4 to 50, and c is 2 to 10 or a mixture of a copolyether with c=1 with one or more copolyether having c=2-10. Finally, x, y, and c are each a number that produces the number-average molecular weight of said copolyether within the range of about 500-10,000 and more preferably within the range of 500-4,000. For spinnable polyesters for use as fibers, a molecular weight range of 500-2,000 is most preferred. For polymers having increased water solubility, the higher ranges are generally preferred.
The first diol can be a straight chain diol having 3 or 6 to 12 carbon atoms per molecule, HO—CH
2
—CH
(2−n)
(CH
3
)
n
—CH
2
—OH, or HO—(CH
2
)
3
—O—(CH
2
)
3
—OH, or combinations of two or more thereof. Preferably it is an &agr;,&ohgr;-alkane diol. A C
2
, C
4
, or C
5
&agr;,&ohgr;-alkane diol tends to yield cyclic ethers rather than a chain structure disclosed above.
Examples of suitable first diols include, but are not limited to, 1, 3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 2-methyl- and 2,2-dimethyl-1,3-propanediols, di(1,3-propylene glycol) (DPG), or combinations of two or more thereof. The preferred first diol is 1,3-propanediol because the copolyether produced therefrom can be used to produce desirable dyeable polyester.
The term “sulfonated dicarboxylic acid” refers to, unless otherwise indicated, either aliphatic sulfonated dicarboxylic acid, aromatic sulfonated dicarboxylic acid, salt thereof, esters thereof, or combinations of two or more thereof. The salt can be an ammonium salt, an alkali metal salt, an alkaline earth metal salt, a phosphonium salt, or combinations of two or more thereof.
Examples of suitable aliphatic sulfonated dicarboxylic acids include, but are not limited to, sulfosuccinic acid, 3-(2-sulfoethyl)hexanedioic acid, and salts thereof Examples of suitable aromatic sulfonated dicarboxylic acids include, but are not limited to, sulfonated phthalic acid, sulfonated isophthalic acid, sulfonated terephthalic acids, sulfona
Sunkara Hari Babu
Yang Yali
Acquah Samuel A.
E. I. Du Pont de Nemours and Company
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