Plant protecting and regulating compositions – Plant growth regulating compositions – Organic active compound containing
Reexamination Certificate
1999-05-04
2001-02-20
Clardy, S. Mark (Department: 1616)
Plant protecting and regulating compositions
Plant growth regulating compositions
Organic active compound containing
C504S360000, C514S341000, C514S383000, C514S772300
Reexamination Certificate
active
06191071
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates to novel plant-treatment compositions based on biodegradable polyester amides containing active compounds, to a process for their preparation and to their use for applying agrochemically active compounds.
BACKGROUND OF THE INVENTION
Numerous thermoplastically processable polymers which contain agrochemically active compounds and can be used in crop protection have already been disclosed (cf. DE-A 4 002 736, U.S. Pat. No. 4,743,448, U.S. Pat. No. 4,666,767 and U.S. Pat. No. 5,201,925). However, these systems have the disadvantage that it is a priori unforeseeable whether a sufficient amount of the active components is released over a sufficiently long period of time. Moreover, after the end of the treatment, polymers and active compound residues remain in the soil or on the plants where they are undesirable and have to be disposed of in a costly manner.
Furthermore, polymeric carrier materials have been disclosed which are partially or completely degraded hydrolytically, during or after their application, by enzymes and/or by microorganisms (cf. Envir. Sci. and Techn. 7 (1973), 955, Coat Plast. Chem. 42 (1980), 436-440, Proc. Int. Symp. Contr. rel. Bioact. Mat. 12 (1985), 179, J. Appl. Pol. Sci 28 (1983), 327-334, “Biomaterials”, Thieme Verlag, Stuttgart-New York, 1987, pages 1-65, Chem. Soc. 1990, 127-148, Chem. Pharm. Bull. 37 (1989), 1954-1956 and Macromolecules 23 (1990), 26-31). Suitable substances for such systems are, for example, polylactic acids and copolymers thereof, polycaprolactone and also polyhydroxybutyrates and copolymers thereof. However, these polymers have hitherto either been unsuitable for an economical formulation of agrochemically active compounds, or the active compounds were not released in a satisfactory manner.
In addition, numerous other biodegradable preparations composed of carrier materials and agrochemically active compounds have been described which release the active components under the application conditions. Thus, suitable carrier substances are, for example, hydrophilic polymers based on polysaccharides, such as starch, into which water-insoluble polymers are incorporated in the form of blends, for mechanical stabilization and to regulate the release of active compounds (cf. Biomaterials 10 (1989) 400-412). However, the biological degradability of these preparations leaves a great to be desired, as does the cost of producing them (cf Study of the European Commission Directorate General XII, EUR 16 102 EN).
It is furthermore possible to use destructured hydrophilic polymers in combination with at least one water-insoluble, synthetic and thermoplastic polymer as carrier substances for active compounds (cf. EP-A 0 344 118). Likewise, it is possible to use blends based on biodegradable starch and synthetic polymers containing at least one free carboxyl group for the abovementioned purpose (cf EP-A 0 404 727). However, it is disadvantageous that in each case only the hydrophilic polymer components are biodegraded, while the other polymer components remain as undesirable residues.
Finally, it has also been disclosed that fibres based on polyhydroxyalkoxides and polysaccharides or copolymers based on tartaric acid and/or lactic acid can act as carriers and/or matrix for active compounds (cf. EP-A 0 132 299, EP-A 0 253 490, EP-A 0 126 827 and DE-A 3 936 191). However, it is unfavourable that the incorporation of the active compounds causes problems, or that the degradability or the release of the active compounds is not always unsatisfactory.
DETAILED DESCRIPTION OF THE INVENTION
This invention, accordingly, provides novel plant-treatment compositions, consisting of
at least one thermoplastically processable biodegradable polyester amide, optionally in a mixture with one or more other thermoplastically processable biodegradable polymer components,
at least one agrochemically active compound and
optionally additives.
Furthermore, it has been found that the compositions according to the invention can be prepared by mixing
a) at least one thermoplastically processable biodegradable polyester amide, optionally in a mixture with one or more other thermoplastically processable biodegradable polymer components,
at least one agrochemically active compound and
optionally additives
and heating to a temperature between 50° C. and 180° C. and
b) converting the resulting thermoplastically processable homogeneous mixture into mouldings or films by extrusion.
Finally, it has been found that the plant-treatment compositions according to the invention are highly suitable for applying agrochemically active compounds in agriculture, in forestry or in horticulture.
It is extremely surprising that the compositions according to the invention are considerably more suitable for applying agrochemically active compounds than the constitutionally most similar preparations of the prior art for the same purpose. It is also unexpected that the compositions according to the invention are stable in water and under moist and warm conditions.
The compositions according to the invention have a number of advantages. Thus, these preparations permit a continuous release of active compound over a prolonged period of time. By varying the rate of degradation of the polymer, the dose of active compound that is released can be adapted to the particular requirements. It is also favourable that the compositions according to the invention are sufficiently stable towards moisture, so that there is no risk of a premature release of active compound by hydrolytic decomposition. Finally, it is a particular advantage that the polymers acting as matrix are completely biodegradable under the conditions of application.
The plant-treatment compositions according to the invention contain one or more thermoplastically processable biodegradable polyester amides. These are to be understood as polymers of this type which have aliphatic ester groups and aliphatic amide groups and are compostable, i.e. which are completely degraded by the action of microorganisms, even under mild conditions.
Preference is given to polyester amides of this kind which have a random arrangement of the ester and amide segments and an average molecular weight of between 5000 and 100,000, preferably between 10,000 and 50,000, particularly preferably between 10,000 and 35,000, based on the number-average molecular weight.
Particular preference is given to polyester amides which are derived from monomers from the groups
of the dialcohols, such as ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,6-hexanediol, diethylene glycol, etc.,
of the trialcohols,
of the dicarboxylic acids, such as oxalic acid, succinic acid, adipic acid, etc., and/or their methyl, ethyl etc., esters,
of the hydroxycarboxylic acids, such as lactic acid and the lactones, such as caprolactone etc.,
of the aminoalcohol, such as ethanolamine, propanolamine, etc.,
of the cyclic lactams, such as &egr;-caprolactam, laurolactam, etc.,
of the &ohgr;-aminocarboxylic acids, such as aminocaproic acid, etc., and/or
of mixtures (1:1 salts) of dicarboxylic acids, such as adipic acid, fumaric acid, etc., and diamines, such as hexamethylenediamine, diaminobutane, etc. and/or
of the hydroxyl- or acid-capped polyesters having molecular weights of between 200 and 10,000 as ester-forming component.
Very particular preference is given to polyester amides which are derived from
cyclic lactams, such as &egr;-caprolactam, as amide-forming component and
1,4-butanediol and adipic acid as ester-forming components
and have a proportion of ester between 30 and 80% by weight, preferably between 35 and 65% by weight, particularly preferably between 35 and 55% by weight.
The polyester amides can contain from 0.1 to 5% by weight, preferably from 0.1 to 2% by weight, of branching agents. Preferred branching agents are trifunctional alcohols, such as trimethylolpropane or glycerol, furthermore tetrafunctional alcohols, such as pentaerythritol, and also trifunctional carboxylic acids, such as citric acid.
The polyester a
Muller Hanns Peter
Priesnitz Uwe
Rast Hans-Georg
Simon Joachim
Bayer Aktiengesellschaft
Clardy S. Mark
Gil Joseph C.
LandOfFree
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