Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form
Reexamination Certificate
1998-06-15
2001-10-16
Webman, Edward J. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
C424S486000
Reexamination Certificate
active
06303131
ABSTRACT:
BACKGROUND OF THE INVENTION
Certain types of polymers exhibit film-forming properties and when dissolved in a solvent, can be applied for the purpose of providing a coating on a substrate. Usually, the film-forming polymer in the solvent is applied to the particular substrate to be coated, and the solvent is allowed to evaporate or removed leaving a film of the polymer. Generally, however, such film-forming polymers are soluble only in organic solvents. The use of such organic solvents generally is undesirable since they exhibit environmentally adverse properties, are often hazardous or flammable, and are generally expensive. In order to avoid the environmentally adverse effects of such organic solvents as well as to reduce the cost involved with using such solvents, rather complicated solvent recovery procedures must be used.
Typical of such polymers are copolymers of N-vinylpyrrolidone with &agr;-olefins, vinyl acetate, styrene, acrylates, acrylic acids, amides, maleic acid, mono and diesters of maleic acids, and the like.
SUMMARY OF THE INVENTION
I have discovered a method for providing a stable microemulsion of a particular class of water-insoluble film-forming polymers in water. The microemulsions thus formed, can be utilized to produce films of the particular film-forming polymer on a given substrate. For example, the microemulsion can be used as a coating for substrates, such as, wood, metal, glass, and the like. In addition, various active ingredient, e.g., fungicides, preservatives, insecticides, insect repellents, pheromones, radiation absorbents, dyes, and the like, can be included in the composition.
The inventive compositions are composed of the water-insoluble polymer, a surfactant, and a long-chain alkylpyrrolidone. The amounts of the polymer surfactant and long-chain alkylpyrrolidone can vary within a broad range. However, the relative compositional ranges of each must be such that a clear, stable microemulsion or solution of the insoluble polymer is obtained on the addition of water.
The water-insoluble polymer used in the present invention are graft polymer vinylpyrrolidone and &agr;-olefin wherein the N-vinylpyrrolidone is present in more than 20 percent on a weight basis. Preferably, the weight percent of N-vinyl pyrrolidone is at least 50 percent. The &agr;-olefin should contain up to 20 carbon atoms.
I have further discovered that the aqueous microemulsion compositions of the invention are particularly suitable for use with an agriculturally active chemical or ingredient (hereinafter, sometimes referred to as a.i.). Thus, the inventive composition of the film-forming polymer may also include an agriculturally active chemical or ingredient, such as, pesticides, herbicides, and the like. This composition may then be applied to plants, or soil, in the usual manner. I have found that the inventive composition, thus used, forms a film incorporating the a.i. on the leaf, soil or seeds and can prevent wash-out of the agriculturally active ingredient due to rain. Thus, for example, the composition with an agriculturally active ingredient forms a film on the particular substrate, e.g., the plant or soil, which results in improved retention and enhanced bioactivity of the agriculturally active ingredient and also provides superior rainfastness for such ingredients on leaf and substrate surfaces.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the following terms have the meaning indicated:
“macroemulsion” means an emulsion of water-in-oil or oil-in-water wherein the interior phase is in the form of visually discernable droplets and the overall emulsion is cloudy, and wherein the droplet diameter is greater than about 10 millimicrons, and usually greater than 1000 millimicrons.
“microemulsion” means an oil-in-water or water-in-oil, transparent thermodynamically stable dispersion of two or more immiscible liquids or a solid in a liquid wherein the dispersed phase consists of small droplets with diameters in the range of about 10 to 100 millimicrons. Such microemulsions are clear and appear as a single phase to the naked eye.
“single phase” as applied to a liquid means that to the naked eye, the liquid is homogeneous and does not appear to contain any other separatable liquid phase.
“clear” or “transparent” as applied to a liquid means that the liquid appears as a single phase without any particulate or colloidal material or a second phase being present when viewed by the naked eye.
“substantially insoluble” or “insoluble” means that for all practical purposes, the solubility of the compound in water is insufficient to make the compound practicably usable in an agricultural end use without some modification either to increase its solubility or dispersability in water, so as to increase the compound's bioavailability or avoid the use of excessively large volumes of solvent.
“High degree of loading in the concentrate” means an agriculturally active ingredient content of at least about 5 percent by weight.
“agriculturally active chemical or ingredient” (AAC or a.i.) means compounds and mixtures thereof which can be used as agricultural fertilizers, nutrients, plant growth accelerants, herbicides, plant growth controlling chemicals, and chemicals which are effective in killing plants, insects, microorganisms, fungi, bacteria and the like which are commonly referred to as insecticides, bactericides, fungicides, nematocides, fumigants, synergists, i.e., compounds which when used in conjunction with other AAC's enhance their activity and the like, as well as any other chemicals having properties which are suitable for agricultural uses in terms of application to plants or domestic uses for controlling insects and pests.
Long-chain N-alkylpyrrolidones suitable for use in the present invention have the formula
wherein R
2
is hydrogen or alkyl having from 6 to 14 carbon atoms and R
3
is alkyl having from 6 to 14 carbon atoms with the proviso that at least one of R
2
or R
3
must contain at least 6 carbon atoms and the sum of the carbon atoms in R
2
and R
3
cannot exceed 14. Preferably, R
2
is hydrogen and R
3
is C
8
or C
12
. Mixtures of two long-chain alkylpyrrolidones may also be used. N-methyl pyrrolidone may also be included along with long chain N-alkylpyrrolidones in an amount effective to help maintain the solubility of the long chain alkylpyrrolidones.
Surfactants suitable for use in the inventive composition include ethoxylated alkyl phenols, linear aliphatic polyesters, linear aromatic polyesters, polyalkenyloxyalcohol, linear aliphatic ethoxylates, polyethoxylated castor oil, polyethoxylated carboxylates, and polyethoxylated alkylamines. Anionic surfactants may be used as the emulsifier and include phosphate esters and their salts, alkyl sulfates, sulfonates, and their salts, salts of sulfate nonylphenoxypoly(ethyleneoxy) ethanol, salts of alkylbenzene sulfonates, salts of alkylnaphthalene sulfonate, and sulfonated aliphatic polyesters and their salts. Also suitable are complex phosphate esters of nonionic surfactants of the ethylene oxide type which are mixtures of diesters of phosphoric acid. (See, for example, McCutcheon's,
Emulsifiers and detergents
(1989), published by McCutcheon's Division of M.C. Publishing Co., Glen Rock, N.J.) Polymers particularly suitable for use in the present invention include polymers, such as, Ganex 516, which is copolymer of an &agr;-olefin and N-vinylpyrrolidone (50/50 percent mixture). Typically, such &agr;-olefins contain up to 20 carbon atoms and preferably, contain 16. The weight average molecular weight of such polymers is generally greater than about 20,000. Particularly suitable are water-insoluble polymers, such as, Agrimer AL25 (International Specialty Products (ISP) Corporation), which is a copolymer of an &agr;-olefin having the formula C
14
H
29
CH═CH
2
(50%) and N-vinylpyrrolidone (50%), and Agrimer AL30 (ISP Corporation), which is a copolymer of an &agr;-olefin having 20 carbon atoms (80%), and N-vinylpyrrolidone (20%). All percents herein are percent by weight based on the to
Davis William J.
Goldberg Jules E.
ISP Investments Inc.
Webman Edward J.
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