Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2000-11-02
2003-11-11
Sanders, Kriellion A. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C427S004000, C524S413000, C524S431000, C524S434000, C524S447000, C524S492000, C524S008000
Reexamination Certificate
active
06646023
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to the use of solid pigment preparations as colorants for coloring seed and seed-dressing materials.
Seed dressing constitutes a widely used form of treating plants with pesticides. Pesticides are understood as meaning, in particular, herbicides, insecticides, fungicides and other crop protection agents.
Nowadays, seed is treated with pesticides in seed-treatment plants in which the pesticides are usually in the form of a “formulation” when mixed with the seed. Suitable mixing methods are, for example, “pelleting”, granulation, or encrusting, during which process either preformulated seed dressing products are applied to the seed in the form of a coating or individual formulation components are applied immediately prior to or during the mixing process. The active ingredients (i.e., pesticides) are generally present in the seed-dressing formulations as solids which are employed, for example, in the form of their wettable powders or granules, aqueous suspensions or emulsions, or suspensions or emulsions that are miscible with water.
The seed-dressing formulations may additionally also contain inorganic or organic binders (for example, film-forming polymers that are miscible with water, surfactants, biocides, thickeners, protective colloids, or antifoams). Usually, however, they additionally contain a colorant, particularly an inorganic or organic color pigment. The purpose of such colorants is to mark or distinguish between certain types of seed by color, to protect the seed from feeding damage by birds, to improve the stability of the formulation formula, or else to serve as filler. The pigments are used either in the form of pigment powders or in the form of liquid, in general water-based, preparations.
The use of red aqueous pigment preparations is described in Examples 1 and 2 of WO-A 99/29169 and the use of inorganic iron oxide pigment powder is described in Example 2 of EP-A-1 3 769.
The colorants (pigments) can be added to preformulated seed-dressing products or added to the seed before or during the mixing process, together with the other formulation components. Customary pigment powders have the disadvantage that the pigment particles are still greatly aggregated or agglomerated, so that complete wetting and dispersion of the pigments during the mixing process is frequently unsuccessful. The great evolution of dust during handling is also disadvantageous.
While, in principle, aqueous (predispersed) pigment preparations permit a more intensive coloring, they lead to an undesired dilution of the seed-dressing products and are therefore suitable for industrial application only to a limited extent. Moreover, they are more complicated with regard to packaging and transport and require specific provision in order to be sufficiently storage-stable (preservation, prevention of drying out, antifreeze protection, and the like). Frequently—for example, in the case of C.I. Pigment Red—aqueous preparations of the prior art show a pronounced tendency to thickening and thus lack storage stability.
There is therefore a desire for new, readily dispersible highly concentrated pigment preparations that may be used in all seed-treatment product application methods and that overcome the disadvantages described above and are economical to produce. In particular, there is a need for pigment preparations in the hue ranges red, blue, green, and white.
Solid pigment preparations are already known in other fields of industrial application, such as, for example, for pigmenting building materials, renderings, and dispersion paints.
DE-A 19 523 204 and DE-A 2 608 993 describe pigment preparations in powder form, as well as processes for their preparation, that are characterized by the use of film formers or protective colloids that are very readily soluble in water (such as, for example, those based on polyvinyl alcohol/vinyl alcohol mixtures, vinyl alcohol copolymers, or polymers of N-vinylpyrrolidone) in addition to pigment and dispersant in order to ensure the good dispersability of the preparations in the aqueous media in which they are used. However, such film formers are undesirable in formulation formulas for seed-dressing materials since they have a thickening effect in the formulas—also as a result of the large quantity that is required—or may undergo other adverse interactions with seed-dressing product components.
Another disadvantage of solid, as well as liquid, pigment preparations comprising organic film formers or protective colloids is that they reflocculate in the aqueous media in which they are used in the course of prolonged mixing times, lose color intensity, and in most cases also change the hue. This applies very particularly to preparations based on copper phthalocyanine pigments and pigments based on laked colorants, which are already widely used in the field of seed-dressing materials in their powder form. Liquid pigment preparations that are based on laked colorants, such as, for example, Colour Index Pigment Red 48:2, and that have been produced in accordance with the prior art additionally have the disadvantage of lacking storage stability with regard to viscosity and coloristic.
There is therefore a need for readily redispersible pigment preparations having improved storage stability and high pigment content without the abovementioned disadvantages of solid pigment preparations of the prior art.
SUMMARY OF THE INVENTION
The invention therefore relates to a method comprising coloring (color pigmentation) seed, seed-dressing materials, or seed-dressing material formulations (preferably aqueous ones) with solid pigment preparations comprising
(a) at least one organic or inorganic pigment and
(b) at least one compound selected from the group consisting of polyether polyols, reaction products of alkylene oxides with alkylatable compounds (such as fatty alcohols, fatty amides, fatty acids, phenols, alkylphenols, carboxamides, and resin acids), or oxalkylated phenols (particularly phenol/styrene polyglycol ethers),
wherein the solid pigment preparations have a water content of less than 10% by weight (preferably less than 3% by weight), based on the pigment preparation, and a mean weight average particle size of 20 to 2000 &mgr;m (preferably 50 to 1000 &mgr;m and more preferably 80 to 500 &mgr;m) and are preferably obtained without the addition of organic protective colloids or film formers.
The solid pigment preparations are preferably obtained in the form of readily flowable, low-dust granules by spray-drying methods.
DETAILED DESCRIPTION OF THE INVENTION
The organic or inorganic pigments of component (a) are not subject to any limitation.
Examples of suitable pigments are those known from the prior art as can be seen, for example, in: Lückert, Pigment+Füllstoff Tabellen [Pigment+Filler Tables], 5th edition, Laatzen, 1994. These materials are insoluble in aqueous media.
Examples of suitable inorganic pigments are white and color pigments.
Inorganic white pigments that may be mentioned are, in particular, oxides such as, for example, titanium dioxide, zinc oxide (ZnO, zinc white), zirconium oxide; carbonates such as, for example, lead white; sulfates such as, for example, lead sulfate; and sulfides such as, for example, zinc sulfide, and lithopones. Titanium dioxide is especially preferred.
Inorganic color pigments that may be mentioned are pigments from the group of oxides and hydroxides as their inorganic individual compounds or as mixed phases, in particular iron oxide pigments, chromium oxide pigments, and oxidic mixed-phase pigments with rutile or spinel structure, and bismuth vanadate, cadmium, cerium sulfide, chromate, ultramarine, and iron blue pigments.
Example of iron oxide pigments are Colour Index Pigment Yellow 42, Pigment Red 101, Pigment Blue 11, Pigment Brown 6, and transparent iron oxide pigments.
Examples of chromium-oxide pigments are Colour Index Pigment Green 17 and Pigment Green 18.
Examples of oxidic mixed-phase pigments are nickel titanium and chromium titanium yellow, cobalt green a
Akorli Godfried R.
Eyl Diderico van
Sanders Kriellion A.
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