Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
2000-12-20
2003-06-03
Jones, Dwayne C. (Department: 1616)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C536S123120, C536S123130
Reexamination Certificate
active
06573375
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to alkoxylated, lipophilic polyol compounds having about three moles of lipophilic substitutuents per mole of polyol and, more specifically, to the use of such compounds as thickeners in liquid surfactant compositions.
BACKGROUND OF THE INVENTION
Liquid compositions containing surfactants, e.g., shampoos, dishwashing liquids and other personal care and industrial products, typically contain thickeners in order to viscosity the liquid compositions sufficiently to enable convenient handling. Often, the thickeners comprise an alkoxylated polyol containing lipophilic substituents, e.g., ethoxylated methyl glucose esterified with a fatty acid. Such thickeners are typically alkoxylated to an extent sufficient to provide water-solubility and provide viscosification to the liquid surfactant composition. The lipophilic substituent, e.g., fatty acid, typically provides associative thickening characteristics to the thickener.
Often, the thickeners are introduced to the liquid surfactant compositions in solid form and mixed under conditions effective to dissolve the thickener into the liquid surfactant composition and cause significant viscosity increases, e.g., up to about 2,000 to 100,000 centipoise (“cP”) or higher. Frequently, the mixing must be conducted at elevated temperatures, e.g., from about 50 to 80° C., in order to promote the dissolution of the thickener and obtain the desired viscosity enhancement (known in the art as “hot processing”). However, formulators of products comprising thickened, surfactant-containing liquids, e.g., shampoos, desire the ability to formulate their products at ambient temperatures, e.g., from about 20 to 30° C. (known in the art as “cold processing”). Additionally, formulators also desire thickeners which can be introduced to the liquid surfactant compositions in a liquid form rather than a solid form. The ability to introduce the thickener in a liquid form can provide a formulator with a greater degree of accuracy in introducing the correct amount of thickener to the liquid surfactant system and also better facilitate automated processing.
Accordingly, improved compositions suitable for use as thickeners in liquid surfactant systems are desired. Preferably, the thickeners can be introduced by cold processing and in a liquid state. Methods for using the compositions to thicken liquid compositions comprising surfactants are also desired.
SUMMARY OF THE INVENTION
By the present invention, alkoxylated, lipophilic polyol compounds, e.g., ethoxylated, esterified methyl glucosides, are provided which are useful, for example, as thickeners in liquid surfactant-containing systems. In the compositions of the present invention, at least 5 wt. % of the polyol compounds have about three moles of the lipophilic substituent per mole of polyol. Quite surprisingly, it has been found in accordance with the present invention that the presence of a sufficient portion of the polyol compounds having about three moles of the lipophilic substituent per mole of the polyol can enhance the ability of the composition to thicken a liquid surfactant system, preferably at cold processing temperatures.
In addition, the present invention provides processes for preparing the compositions which include the steps of alkoxylating the polyol with a suitable alkoxylation reagent, e.g., ethylene oxide, and introducing a lipophilic substituent, e.g., by esterification with a fatty acid. The processes also provide for introducing the lipophilic substituents prior to the alkoxylation step as well as sequential introductions of the lipophilic substituent and the alkoxylating reagent.
DETAILED DESCRIPTION OF THE INVENTION
The polyols suitable for use as starting materials in accordance with the present invention comprise any compounds having three or more hydroxyl groups per molecule which are reactive with the alkoxylation reagents and the lipophilic reagents described below. General examples include glycerols, polyglycerols, sugar alcohols, e.g., sorbitol or sorbitan, and saccharides, e.g., glucose and its derivatives. More specific examples of the polyols which can be used according to the invention include, but are not limited to, trimethylolethane [2-methyl-2-(hydroxymethyl)-1,3-propanediol], trimethylolpropane[2-ethyl-2-(hydroxymethyl)-1,3-propanediol], pentaerythritol (2,2-dimethylol-1,3-propanediol), diglycerol (glycerol dimer), dipentaerythritol, glycerol, and the like.
Preferred polyol starting materials for use in accordance with the present invention are glucose derivatives, more preferably, glycosides, e.g., glucosides, galactosides, monosaccharides, oligosaccharides having up to about 10 saccharide repeat units per molecule and sucrose. Especially preferred glucosides include alkyl glucosides, such as for example, methyl glucoside, ethyl glucoside, propyl glucoside, butyl glucoside and amyl glucoside.
Such polyols are commercially available.
Suitable reagents for alkoxylating the polyols are alkylene oxides, such as, for example, ethylene oxide, propylene oxide, butylene oxide and mixtures thereof. Other alkoxylating reagents, e.g., higher alkylene oxides, may be used in accordance with the present invention. Alkylene oxides suitable for use in accordance with the present invention are commercially available. The amount of alkoxylation in accordance with the present invention is that which is effective to provide water solubility and viscosification in a liquid surfactant composition. Typically, such amounts range from about 50 to 400, preferably from about 80 to 180 and more preferably from about 100 to 160 moles of alkylene oxide per mole of polyol. Methods for alkoxylating polyols, e.g. by direct alkoxylation, are known to those skilled in the art. Alternatively, partially alkoxylated methyl glucosides, e.g., GLUCAM™ E-20 (PEG-20 methyl glucoside) available from Amerchol Corporation, Edison, N.J., can be used as a starting material which can then be further alkoxylated to contain the desired degree of alkoxylation.
The lipophilic reagents suitable to derivatize the polyols of the present invention include any compounds which are reactive with the polyols and have sufficient molecular weight to promote associative thickening when introduced into a liquid, surfactant-containing system. Typically, the lipophilic reagents comprise hydrocarbon or substituted hydrocarbon moieties with from about 8 to 30, preferably from about 12 to 26 and more preferably from about 16 to 22 carbon atoms per molecule. The particular structure of the lipophilic reagents is not critical to the present invention and may, for example, be alkyl, aryl, alkylaryl, alkenyl and may be cyclic, branched or straight. Typically, the reagents are fatty acids, fatty esters, epoxides, halides glycidyl ethers, or vegetable or animal oils. The reagents typically provide either an ester or ether linkage to the polyol. Stated another way, in the case of a glucose derivative, for example, the ether or ester is typically attached to the glucose derivative indirectly through a polyoxyalkylene chain.
Examples of suitable fatty acids include natural or synthetic saturated or unsaturated acids which are linear or branched. The fatty acids can be used alone or as a mixture. Natural fatty acids include, for example, saturated or unsaturated linear fatty acids such as caproic acid, enanthic acid, caprylic acid, pelargonic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, linolic acid, oleic acid, capric acid and undecanoic acid which are typically obtained by hydrolyzing vegetable oils and animal oils such as coconuts oils, palm oil, tallow, linseed oil and soybean oil. Examples of synthetic fatty acids, include linear or branched fatty acids prepared by oxidizing olefin polymers. It is also possible to use fatty acids derived from microorganisms such as, for example, &ggr;-linolenic acid. Further, as the lower alkyl ester of the fatty acid, alkyl esters having 1 to 8 carbon atoms such as methyl, ethyl or propyl ester of the fa
Barbeito Carmella A.
Diantonio Edward F.
Kreeger Russell Lowell
Li Wing Kin
Polovsky Stuart Barry
Jones Dwayne C.
Union Carbide Chemicals & Plastics Technology Corporation
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