Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2000-11-30
2003-06-10
Acquah, Samuel A. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C528S275000, C528S295000, C528S298000, C528S300000, C528S301000, C528S302000, C528S307000, C528S308000, C528S308600, C525S437000, C252S008620, C252S008830, C252S008840, C510S281000, C510S299000, C510S477000
Reexamination Certificate
active
06576716
ABSTRACT:
FIELD OF THE INVENTION
The present invention is directed to a process of producing sulfonated polyester compounds suitable for use as a soil releasing agent and/or textile sizing agent in which a sulfonated acid or ester is reacted with a hydroxy-containing compound to form a sulfonated hydroxy terminated ester which then undergoes a transesterification reaction with a poly(ethylene) terephthate based polyester followed by polycondensation to form the desired sulfonated polyester compound. The present invention provides lower cost, reduced cycle times and improved yields over conventional processes for the production of sulfonated polyester compounds.
BACKGROUND OF THE INVENTION
Sulfonated polyester compounds are known for removing soil and stains from a variety of substrates including filaments, fibers, fabrics, films and the like. Low molecular weight sulfonated polyester compounds are typically employed as soil release agents in laundry detergents while higher molecular weight sulfonated polyester compounds have been used for textile sizing.
U.S. Pat. No. 3,962,152 discloses a detergent composition containing polymers as soil release agents which are obtained by reacting dimethyl terephthalate with polyethylene glycol.
U.S. Pat. Nos. 4,863,619; 4,925,577 and 5,041,230 generally disclose methods of improving the processability of soil release polymers.
U.S. Pat. No. 4,999,128 discloses copolymers of poly(ethylene terephthalate/ethylene isophthalate) and related copolymers which are produced by reacting the esters with polyethylene glycol.
U.S. Pat. No. 5,142,020 discloses soil release promoters and detergents which are obtained by the polymerization of monomers such as dicarboxylic acid/ester/anhydride, dihydric alcohols and polyethylene glycols.
Sulfonated polyester compounds have received increased attention as effective soil release agents. For example, U.S. Pat. No. 3,557,039 discloses a stable aqueous dispersion comprising water and a water insoluble crystallizable block or graph polymeric compound which contains linear polyethylene terephthalate segments having sufficient ethylene terephthalate units to confer crystallinity to the compound. These polymers are prepared by reacting monomers which include dimethyl sodium sulfoisophthalate.
U.S. Pat. No. 4,427,557 discloses sulfonated copolymers used for preparing anionic textile treating compositions in which the polymerizable monomers include dimethyl sulfoisophthalate.
U.S. Pat. No. 4,702,857 discloses sulfonated copolymers used as soil release agents in detergent formulations in which the copolymers are obtained by polymerizing monomers such as dimethyl terephthalate, dimethyl sulfoisophthalate, polyethylene glycol and polyethylene glycol monoether.
U.S. Pat. No. 5,599,782 also discloses sulfonated polyester compounds useful as soil release agents. Polymerizable monomers which are mentioned in the reference include m-sodiosulfobenzoic acid, dimethylsodiosulfoisophthalate, dimethyl terephthalate, terephthalic acid and ethylene glycol.
U.S. Pat. No. 5,728,671 discloses sulfonated polyester compounds useful as soil release agents having whitening properties.
U.S. Pat. No. 5,786,318 discloses polymerizing such monomers as sulfonated aromatic dicarboxylic acids to produce soil release polymers for detergent compositions. Other soil release polymers containing sulfonated polymers are disclosed in U.S. Pat. Nos. 5,789,365; 5,789,366; and 5,789,367.
The market for polyester compounds for use as soil releasing agents and/or textile sizing agents and particularly sulfonated polyester compounds for this purpose has increased significantly in recent years. However, increased demand has spurred efforts to improve production capability of the desired sulfonated polyester compounds.
Traditional methods of producing sulfonated polyester compounds for use as soil releasing agents and/or textile sizing agents are problematical for reasons which include expensive starting materials, lengthy process cycle (i.e. the time it takes from the initial reaction to the production of a finished product) and low yields of the desired product or relative low reactor throughput. By way of example, the production of a sulfonated polyester compound through a transesterification reaction of dimethyl terephthalic and dimethyl-5-sulfoisophthalate with excess ethylene glycol, followed by esterification with terephthalate acid and then polycondensation undergoes a typical cycle time of about 38.5 hours for processing a 15 ton batch of polyester. Since the reaction produces 35% of distillate, the long cycle time and low yield or reactor throughput makes it very difficult to meet the requirements of the growing market demand for such sulfonated polyester compounds.
SUMMARY OF THE INVENTION
The present invention is directed to a process for the production of sulfonated polyester compounds in which reaction yields and cycle time are significantly improved over conventional processes for the production of the same or similar compounds. The present method is generally directed to the production of a sulfonated polyester compound suitable for use as a soil releasing agent and/or textile sizing agent in which a sulfonated acid or corresponding alkyl ester is reacted with a hydroxy-containing compound to produce a sulfonated ester intermediate compound which is then reacted with a polyester compound selected to afford the final polyester compound with a desired molecular weight.
In a particular aspect of the present invention, there is provided a method of producing a sulfonated polyester compound suitable for use as a soil releasing agent and/or textile sizing agent comprising:
a) reacting at least one compound of Formula (I)
XSO
3
—R—(COOY)n (I)
wherein
X is a cation,
R is an aryl group,
Y is selected from the group consisting of hydrogen and an alkyl group, and
n is a positive integer with at least one compound of Formula (II)
R
1
—(OH)m (II)
wherein R
1
is selected from the group consisting of an alkyl group, a cycloalkyl group and an aryl group, which may be substituted with an alkyl group or an aryl group, and m is a positive integer and optionally with a compound of Formula (III)
R
2
—(COOZ)p (III)
wherein R
2
is selected from the group consisting of an alkyl group and an aryl group, Z is selected from the group consisting of hydrogen and an alkyl group, and p is a positive integer, and optionally with a compound of Formula (IV)
wherein R
3
and R
4
are each independently selected from the group consisting of hydrogen and an alkyl group, and q is a positive integer to produce at least one ester compound intermediate, and reacting the resulting ester compound intermediate with a homo—or co-poly(ethylene terephthalate) to produce the sulfonated polyester.
DETAILED DESCRIPTION OF THE INVENTION
The method of producing a sulfonated polyester compound in accordance with the present invention for use as a soil releasing agent and/or textile sizing agent begins with the reaction of at least one compound of Formula (I)
XSO
3
—R—(COOY)n (I)
wherein X is a cation, R is an aryl group which may be substituted with an alkyl group or an aryl group, Y is selected from the group consisting of hydrogen and an alkyl group and n is a positive integer. The cations available for X include, for example, sodium, lithium, potassium, NH
4
and tetrabutylphosphonium. Sodium is the preferred cation for the compound of Formula (I). R is an aryl group and includes, for example, phenyl, and naphthyl.
The starting sulfonated compound may be in the form of an acid wherein Y is hydrogen or in the form of an alkyl ester. Preferred alkyl groups are methyl, ethyl, propyl and butyl with methyl being the preferred alkyl group. The number of acid or ester groups is from 1 to 4, preferably 1 or 2. The most preferred number of acid or ester groups is 2.
Examples of suitable compounds of Formula (I) include dimethyl-5-sodiosulfoterephthalate, 5-sodiosulfoterephthalic acid, 5-lithoisophthalic acid, 3-sodiosulfobenzoic acid, and 4-sodiosulfodiphenyl
Acquah Samuel A.
Rhodia INC
Watov & Kipnes P.C.
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