Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Biocides; animal or insect repellents or attractants
Reexamination Certificate
2001-05-17
2002-10-15
Travers, Russell (Department: 1617)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Biocides; animal or insect repellents or attractants
C424S409000, C514S613000, C514S622000
Reexamination Certificate
active
06464996
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to compositions comprising an organic fluid, a surfactant and a thickening agent. The compositions are useful in many applications, particularly as a thickened oil flowable concentrate in which a pesticide may be incorporated.
BACKGROUND OF THE INVENTION
There is a need to package pesticides in non-aqueous concentrates that can be diluted and dispersed to sprayable application concentrations in water. As conventionally understood, the term, pesticide, is inclusive of insecticides, herbicides, fungicides, and other active ingredients. When the pesticide active ingredient is soluble in, for example, a hydrocarbon fluid, an emulsifiable concentrate solution can be made by combining suitable surfactants with the hydrocarbon fluid and active ingredient. When the active ingredient is not soluble in an organic fluid and not chemically stable in water, an alternative approach is needed.
One approach is to suspend pesticide particles in an organic fluid/surfactant solution. For the particles to remain suspended and not settle to the bottoms of their containers, the solution viscosity, before pesticide particles are added, generally must be about 1000 cP. This could be achieved with viscous hydrocarbon oils; however, most viscous hydrocarbon oils are phytotoxic. Consequently, one would prefer to use lower viscosity organic fluids that are not phytotoxic and to then thicken or viscosify the fluids to a suitable viscosity with a thickening agent. Common thickening agents for organic fluids that could be used include soluble polymers and network or structure forming compounds such as fumed silicas, clays, and materials that are crystalline or semi-crystalline in the fluid at application temperature, but soluble in the fluid at an elevated temperature.
While all these agents can thicken organic fluids, many are not compatible with the surfactants needed to disperse the concentrate in water. For example, a small concentration (about 5 wt %) of a high molecular weight (about 2 million) polyisobutylene can thicken a mixed aliphatic hydrocarbon. When a blend of surfactants that is soluble in the aliphatic hydrocarbon and capable of dispersing it in water is added, the complete mixture does not form a solution, but instead separates into two phases. Such two-phase mixtures are not suitable for the present application. A similar amount of a hydrophobic fumed silica can also thicken a mixed aliphatic hydrocarbon; however, when the same dispersing surfactant blend is added, the viscosity of the solution drops back close to the level of the neat hydrocarbon fluid, and the mixture is not suitable for the present application.
Another approach is to use small molecule thickening agents that build intermolecular networks and viscosity via, for example, hydrogen bonding. One such system, described in U.S. Pat. No. 3,634,050, uses the reaction product of gamma-butyrolactone and cocoalkylamine to gel hydrocarbon fluids. This system can accommodate the addition of surfactants needed to disperse the fluid in water, but it has a sharp transition from a low viscosity liquid to a gelled semi-solid as the concentration in the hydrocarbon fluid is increased. Consequently, it, too, is an unsuitable thickening agent for the present application.
It is an objective of the present invention to provide a composition comprising an organic fluid, a surfactant and a thickening agent, which composition is flowable, uniform, has sufficient viscosity to stabilize a pesticide when incorporated therein, and is dispersible in water.
It is a further objective of the present invention to provide compositions comprising a pesticide and a thickened organic fluid/surfactant composition as described herein.
These and other objects and advantages of the present invention will be apparent to those skilled in the art from the following detailed description and claims.
SUMMARY OF THE INVENTION
In accordance with this invention, it has been found that the above and still further objects are achieved by providing a composition comprising at least one, or more, organic fluids, at least one, or more, surfactants, and as a thickening agent a compound having the formula
where R is a linear or branched alkyl group having about 2 to about 6 carbon atoms, preferably 3 to 5 carbon atoms, or mixtures thereof; and
where X is a mixture of linear or branched alkyl or alkyl ether groups each having about 6 to about 21 carbon atoms, and from about 25 wt % to about 75 wt %, preferably 50 wt %, of the X groups have an average carbon number that is at least 4, preferably 6, more than the average carbon number of the other X groups.
The composition is uniform, flowable, and dispersible in water and has a viscosity that is from about 10 to about 1000 times larger than the viscosity of a corresponding composition having the same amounts of organic fluid and surfactant, but containing no thickening agent.
In accordance with this invention, it has been further found that there are provided useful pesticidal compositions comprising a pesticide and the thickened composition described herein, which thickened composition is uniform, flowable, dispersible in water, and has a viscosity that is from about 10 to about 1000 times larger than the viscosity of a corresponding composition having the same amounts of organic fluids and surfactants, but containing no thickening agent, and comprises at least one organic fluid, at least one surfactant, and as a thickening agent a compound having the formula
where R is a linear or branched alkyl group having about 2 to about 6 carbon atoms, preferably 3 to 5 carbon atoms, or mixtures thereof; and
where X is a mixture of linear or branched alkyl or alkyl ether groups each having about 6 to about 21 carbon atoms, and from about 25 wt % to about 75 wt %, preferably 50 wt %, of the X groups have an average carbon number that is at least 4, preferably 6, more than the average carbon number of the other X groups.
DETAILED DESCRIPTION OF THE INVENTION
The thickened organic fluid/surfactant compositions and the pesticidal compositions of the present invention are described in further detail as follows.
The thickened organic fluid/surfactant composition comprises:
(a) from about 82 to about 94 weight % of at least one, or more, organic fluid,
(b) from about 5 to about 15 weight % of at least one, or more, surfactant that is soluble in the organic fluid and is capable of dispersing the organic fluid in water, and
(c) from about 1 to about 3 weight %, as a thickening agent, of a compound having the formula
where R is a linear or branched alkyl group having about 2 to about 6 carbon atoms, preferably 3 to 5 carbon atom, or mixtures thereof; and
where X is a mixture of linear or branched alkyl or alkyl ether groups each having about 6 to about 21 carbon atoms, and from about 25 wt % to about 75 wt %, preferably 50 wt %, of the X groups have an average carbon number that is at least 4, preferably at least 6, more than the average carbon number of the other X groups.
The composition is uniform, flowable, and dispersible in water and has a viscosity that is from about 10 to about 1000 times larger than the viscosity of a corresponding composition having the same amounts of organic fluid and surfactant, but containing no thickening agent.
Suitable organic fluids for use in the thickened compositions herein include, but are not limited to, aromatic and aliphatic hydrocarbons, alkyl esters, aromatic esters, glycol ethers, and mixtures thereof. Preferred fluids have flash points above 61° C., and most preferred fluids have flash points above 93° C. Neat fluid viscosities should also be below about 20 cP at 25° C. Examples of preferred fluids include Exxsol® D110 Fluid, Exxate® 1000 Fluid, Isopar® M Fluid, Norpar® 13 Fluid, Norpar® 14 Fluid, and Aromatic Fluid, all available from ExxonMobil Chemical Company.
Suitable surfactants for use in the thickened compositions herein include, but are not limited to, alkanolamides, alkylarylsulfonates, alkoxylated alcohols, alkoxylated alkylphenols, alkoxylated
Chokshi Kishore K.
Frisch Paul Douglas
Kowalik Ralph Martin
Kuo Karen K.
Tann R. Scott
ExxonMobil Chemical Patents Inc.
Jiang S.
Travers Russell
LandOfFree
Thickened organic fluid/surfactant compositions and use... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thickened organic fluid/surfactant compositions and use..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thickened organic fluid/surfactant compositions and use... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2954096