Organic compounds -- part of the class 532-570 series – Organic compounds – Sulfate esters
Reexamination Certificate
2001-08-01
2002-09-17
Lambkin, Deborah C. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Sulfate esters
C568S027000
Reexamination Certificate
active
06452035
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a convenient, high yield process for sulfating alcohols. The process of the present invention is adaptable to sulfating a wide range of alcohols including the hydroxyl unit which terminates a polyalkoxylate moiety which are prevalent in the area of surfactants, inter alia, alkyl ethoxy sulfates. The sulfation process of the present invention can be used to sulfate poly-alcohols or amino alcohols, the latter which can serve to provide a key element necessary for sulfation.
BACKGROUND OF THE INVENTION
The most common process for manufacturing alcohol sulfates encompasses falling film reaction techniques. This process most often uses SO
3
as the sulfation reagent to sulfate the parent alcohol. While this technique is well known in the industry, it requires specialized equipment and can produce unwanted side products. In particular, dioxane is usually produced by side reactions when ethoxylated materials are involved. Other complications in falling film sulfation can lead to salt by-products, over-sulfation and color/odor issues. In addition, falling film reactors are not easily adapted for use in sulfating alcohols wherein the desired product is a non-aqueous, high active composition due to the industry practice of using aqueous base such as sodium hydroxide to neutralize the acidic initial sulfation product.
There is therefore a long felt need to provide a convenient process for controllably sulfating hydroxy units without the need for specialized equipment. There is also a long felt need for a process for sulfating alcohols to produce a non-aqueous, high active product. In addition, there is a long felt need for a alcohol sulfation process which minimizes unwanted side reactions and salts. In addition, there is a long felt need to controllably sulfate amino alcohols, the product of which process yields zwitterionic materials, for example, surfactants.
SUMMARY OF THE INVENTION
The present invention meets the aforementioned needs in that it has been surprisingly discovered that hydroxyl moieties can be controllably sulfated by the trans-sulfation process described herein. In an important embodiment of the present invention, a portion of the substrate to be sulfated, can serve as a reagent participating in the process as an essential element or component, for example, as a source of amino moiety. The sulfation process of the present invention allows the formulator to introduce into the molecule to be sulfated a pre-determined degree of sulfation. In addition, the reagents which are required to perform the process of the present invention minimize unwanted by-products, inter alia, inorganic salt by-products due to neutralization, or side products, inter alia, dioxane and other cyclic ethers. The process of the present invention can be conducted in standard chemical reaction vessels instead of specialized equipment such as falling film reactors. A further advantage of the present process is the ability to produce anhydrous, high active sulfated alcohols.
The first object of the present invention relates to a sulfation process comprising the steps of:
a) reacting a tertiary amine with a sulfation precursor having the formula:
wherein R
1
is C
1
-C
22
alkyl, C
7
-C
22
alkylenearyl, and mixtures thereof; to form an admixture comprising a quaternized amine and a sulfating species; and
b) reacting a hydroxyl species with said admixture to form a sulfated hydroxyl species.
A further aspect of the present invention relates to a trans-sulfation process comprising the steps of:
a) reacting n equivalents of an amine moiety with n equivalents of a sulfation precursor to form n equivalents of a sulfating species; and
b) reacting said n equivalents of a sulfating species with a substrate having n hydroxyl moieties to form a compound having n sulfated hydroxyl moieties.
The present invention also relates to a trans-sulfation process comprising the steps of:
a) reacting n equivalents of a tertiary amine moiety with n equivalents of a sulfation precursor to form n equivalents of a sulfating species; and
b) reacting said n equivalents of a sulfating species with a substrate having m equivalents of hydroxyl moieties to form a compound having up to n sulfated hydroxyl moieties.
A yet further aspect of the present invention relates to a trans-sulfation process comprising the steps of:
a) reacting an amine-comprising compound having n equivalents of amine moieties and an auxiliary amine having n′ equivalents of amine moieties with n+n′ equivalents of a sulfation precursor to form n+n′ equivalents of sulfating species, and wherein said amine-comprising compound further comprises m hydroxyl moieties; and
b) forming m or less sulfated hydroxyl moieties.
These and other objects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (°C.) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process for sulfating hydroxyl moieties. The process of the present invention in the most general view is a trans-sulfation process comprising a step which forms a sulfating species and a step which provides controllable sulfation of one or more hydroxyl moieties.
Importantly, the process of the present invention can be used to selectively and controllably sulfate the hydroxyl moieties which terminate alkoxylated or polyalkoxylated units, inter alia, alcohols, polyols, saccharides, amines, and polyamines, including polyalkyleneimines. The process of the present invention is especially adaptable to compounds which comprise one or more tertiary nitrogens said nitrogens to be subsequently quaternized.
For the purposes of the present invention the term “hydroxyl-comprising compound” is defined herein as “any organic or inorganic compound having a hydroxyl moiety, —OH, which is capable of being sulfated by the process of the present invention.” Preferably the “hydroxyl-comprising compound” is a compound which is the compound to be sulfated.
For the purposes of the present invention the term “amine-comprising compound” is defined herein as “any organic or inorganic compound having at least one un-oxidized nitrogen, for example, a nitrogen which is not an N-oxide nitrogen, which is capable of accepting an R
1
unit as defined herein below and thereby generating a sulfating species as described herein below.”
For the purposes of the present invention the terms “sulfation precursor” and “sulfating species” are used interchangeably and are taken to mean a reagent as defined herein below which when reacted in step (a) of the present process forms a chemically reactive species, “sulfation species”, which further reacts to sulfate hydroxyl moieties.
The first required step of the present process, Step (a), is conducted under non-acidic conditions. The second required step of the present process, Step (b), is conducted under acidic conditions.
The following describes the required steps of the present process.
Step (a): Formation of a “sulfating species”. Formation of a sulfating species is the first required step of the process of the present invention.
In a preferred embodiment of the present invention, one equivalent of a sulfation precursor (sulfating agent) is reacted with one tertiary amine moiety to form one equivalent of a sulfating species. In a second embodiment of the present invention, one equivalent of a sulfation precursor is reacted with one amine moiety to form one equivalent of a sulfating species.
In another embodiment of the present invention, up to two equivalents of a sulfating agent is reacted with one secondary amine moiety to form, up to two equivalents of sulfating species. In yet another embodiment, up to three equivalents of sulfating agent is reacted with one primary
Dupont Jeffrey Scott
Gosselink Eugene Paul
Cook C. Brant
Echler Sr. Richard S.
Lambkin Deborah C.
The Procter & Gamble Co.
William Zerby Kim
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