Seed coating composition

Abstract

A seed coating composition comprises an aqueous polymer dispersion, obtainable by radical aqueous emulsion polymerization of a mixture comprising a) ethylenically unsaturated monomers M, with M comprising at least one vinyl ester M1, and at least one (meth)acrylic acid ester M2, b) a carboxyl-groups-containing compound CGCC, c) at least one non-carboxylated saccharide and / or polysaccharide S, and d) at least one emulsifier selected from non-ionic and anionic surfactants, wherein the dispersion has a pH of up to 4. The aqueous polymer dispersion is useful as a binder in compositions, in particular in aqueous compositions for seed coating / dying, and seeds coated with such compositions show reduced dust formation without impaired flowability / sowability.

Description

[0001] Seed Coating Composition

[0002] The present invention relates to a seed coating composition comprising an aqueous polymer dispersion; to the use of said aqueous polymer dispersion for coating seeds; to a coated seed obtainable by the coating of the seed with said composition; to a coated seed comprising a layer coating a part or the complete surface of the seed, wherein the layer is formed from the seed coating composition; to a method for preparing a coated seed comprising contacting a part or the complete seed to be coated with said composition; and to the use of the aqueous polymer dispersion as a binder in seed coating compositions.

[0003] TECHNICAL BACKGROUND

[0004] Seeds are often coated, e.g. to prevent ingression of humidity and thus, inter alia, premature germination or deterioration by microorganisms. Seeds may moreover be treated with seed treatment agents, e.g. with fungicides, pesticides, herbicides, plant nutrients, growth stimulating agents or inoculants, and / or may be dyed, especially when treated. Seed treatment is for example carried out to protect the seeds or the plants growing therefrom from attack by fungi, invertrebrate pests and the like, to stimulate emergence and plant growth, etc. Dying is for example carried out for differentiating various types of seeds or seed coatings, for marketing (branding for specific manufacturers) or identification purposes, for checking of seed deposition, as a warning signal, for an easier cleaning up after accidental spillage and also for a repellent effect.

[0005] To form a layer coating a part or the complete surface of the seed, generally a binder is used. Typical binders used for this purpose are polymers formed from ethylenically unsaturated monomers, such as carboxylated styrene / butadiene polymers; polyamides or acrylic binders. Disadvantageously, such binders are not biodegradable and accumulate in the soil.

[0006] There is an urgent need to reduce the introduction of (micro)plastic into the environment, to be more precise of (micro)pl astic which is not or not readily biodegradable.

[0007] Another problem associated with seeds, in particular with treated seeds, is dust formation. Generally, dust from treated seeds represents a health hazard for humans and animals coming into contact therewith, e.g. during or after sowing, or during transport, packaging, processing etc.. But also dust from non-treated seeds, stemming for example from seed husks, may represent a health hazard.

[0008] It is an object of the present invention to provide a composition for coating and in particular for dying seeds which has a reduced environmental impact. The seeds coated therewith should have moreover a reduced dust formation, thusly reducing the environmental impact also in this respect, and also reducing the health risks for those coming into contact with the coated seeds and dust produced therefrom, e.g. during sowing, or during transport, packaging, processing etc. Dust suppression should however not be to the expense of plantability / sowabi lity, i.e. the seeds should not stick to each other or to the sowing device, and they should show a good flowability.

[0009] BE 1009840A5 relates to a seed treatment method, especially for sugar beets, that ensures delay of germination. To this purpose, the seeds are protected with a waterproof and biodegradable substance which has a predetermined biodegradation rate over time. The waterproof layer is destroyed as soon as the temperature reaches 8-10°C in early spring, allowing the seeds to germinate. As a suitable biodegradable plastic material, polycaprolactones with a molecular weight of from 4000 to 50000 are mentioned. The biodegradable plastic layer is prepared by minuting the material to powder, adding a glue and applying this mixture by hot-melt fluid bed coating to the (treated) seed. On top of this layer, a protective layer containing e.g. resins is applied to prevent the seeds from sticking to each other. This reference neither mentions aqueous polycarprolactone formulations nor dyed seeds nor the use of polycaprolactones as binders in general and especially not as binders for pigments for seed dying.

[0010] EP 0145086 A2 relates to seeds coated with an anhydrous coating, wherein the coating contains a polyester, such as homo- and copolymers of s-caprolactone, having a low melting temperature. The polyester is applied to the seeds in liquid or melted form or in form of a non-aqueous concentrated solution in an organic solvent. Coatings applied according to the method of this document have generally a thickness in the mm range.

[0011] SUMMARY OF THE INVENTION

[0012] The invention relates thus to a seed coating composition comprising an aqueous polymer dispersion, obtainable by radical aqueous emulsion polymerization of a mixture comprising a) ethylenically unsaturated monomers M, with M comprising

[0013] (1) at least one vinyl ester (M1), preferably comprising vinyl acetate, more preferably comprising vinyl acetate at least 50%, and

[0014] (2) at least one (meth)acrylic acid ester (M2) optionally comprising methacrylic acid as minor component, the (meth)acrylic acid in the methacrylic acid ester being bonded via an ether-function to a polyalkylene oxide-derived-block (PAO), wherein the PAO consists of 2 to 40 alkylene oxide units (AO-units), most preferably 25 AO-units, with the PAO preferably being further linked via an ether- function to an C1 to C24, preferably at least C4, more preferably at least C6, even more preferably C8 to 024-aliphatic alkanol, most preferably a C18-aliphatic alkanol, with the AO being preferably selected from EO, PO and / or BuO, more preferably at least EO in an amount of from 50, more preferably at least 75, even more preferably at least 90 wt.% most preferably essentially only EO, based on total AO; preferably comprising methacrylic acid, more preferably with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%; (3) optionally further monomers (M3) polymerizable with M1 and M2, preferably none; b) 1 to 15, preferably 2 to 10%, based on the total weight of monomers M, of a carboxyl-groups-containing compound (CGCC) being selected from a compound bearing in its structure at least three carboxylgroups of which at least 10 and at most 90 percent are being deprotonated, selected from the group comprising citric acid, isocitric acid; ethylendiamintetraacetic acid; nitriloacetic acid; tartaric acid; oligomeric and polyacrylic acid; oligomeric and poly methacrylic acid; trimelitic acid; oligomeric aminoacids with carboxy groups such as polyaspartic acid; oligomeric and polyglutaminic acid; oligomeric and polyacetates with carboxygroups such as poly(glyoxalic)aldehyde; carboxylated oligomeric and polymeric saccharides such as oxidized starch (mixtures of amylopektines, amylose); polyglucuronates; cellulose oxidized to cellouronate; natural polycarboxylatic polysaccharide such as xylanes; pektines acid; alginic acid; carboxymethylated polysaccharides based on 1 ,4-polyglucanes, 1,3- polyglucanes, 1,6-polyglucanes; Poly-uronic acids based on 1,4-polyglucanes, 1 ,3-polyglucanes, 1,6- polyglucanes; polygalacturonic; preferably carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose (carboxymethylcellulose, “CMC”); c) at least one non-carboxylated saccharide and / or polysaccharide (S), such as glucose, starch degradation products, maltodextrin, in an amount of 2 to 50, preferably 5 to 35wt% based on the total weight of monomers M; d) at least one emulsifier selected from non-ionic and anionic surfactants; e) optionally sulfate ions; and f) optionally sulfite ions; wherein - preferably - the amount of M1 is from 80 to 99.99 mol%, and the amount of M2 is from 0.01 to 20 mole%, and preferably at most 10, even more preferably at most 5, more preferably at most 2%, the total amount of M1 plus M2 being 100 weight percent, and wherein the dispersion has - after the end of the polymerization - a pH of up to 4.

[0015] The present inventors found that the aqueous polymer dispersion as described above is useful as binder in compositions, in particular in aqueous compositions for seed coati ng / dying, and that seeds coated with such compositions show reduced dust formation without impaired flowability / sowability.

[0016] The composition typically comprises water in an amount to form a continuous phase in dissolved, suspended and / or emulsified form. Water introduced with the aqueous polymer dispersion contributes to the water in the seed coating composition.

[0017] The invention relates moreover to the use of the aqueous polymer dispersion for coating seeds.

[0018] In a further aspect, the invention relates to a coated seed, obtainable by the coating of the seed with said composition; and to a coated seed comprising a layer coating a part or the complete surface of the seed, wherein the layer is formed from the composition. In yet another aspect, the invention relates to a method for preparing a coated seed, comprising contacting a part or the complete seed to be coated with said composition.

[0019] Finally, the invention relates to the use of the aqueous polymer dispersion as a binder for pigments in seed coating compositions.

[0020] DEFINITIONS

[0021] All terms have their ordinary meaning unless specifically defined otherwise within this disclosure either in the following or throughout the description.

[0022] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integer or step. When used herein the term “comprising” can be substituted with the term “containing” or “including” or sometimes when used herein with the term “having”.

[0023] When used herein, “consisting of" excludes any element, step, or ingredient not specified in the claim element. When used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim.

[0024] In each instance herein any of the terms "comprising”, "consisting essentially of" and "consisting of" may be replaced with either of the other two terms. “Comprising” may be replaced in a preferred embodiment with "consisting essentially of and both may be replaced by "consisting of" in an even more preferred embodiment.

[0025] The compositions of the present disclosure can “comprise” (i.e. contain other ingredients), “consist essentially of” (comprise mainly or almost only the mentioned ingredients and other ingredients in only very minor amounts, mainly only as impurities), or “consist of (i.e. contain only the mentioned ingredients and in addition may contain only impurities not avoidable in an technical environment, preferably only the ingredients) the components of the present disclosure.

[0026] Similarly, the terms “substantially free of....” or" substantially free from...” or “(containing / comprising) essentially no....” may be used herein; this means that the indicated material is at the very minimum not deliberately added to the composition to form part of it, or, preferably, is not present at analytically detectable levels. It is meant to include compositions whereby the indicated material is present only as an impurity in one of the other materials deliberately included. The indicated material may be present, if at all, at a level of less than 1 %, or even less than 0.1%, or even more less than 0.01%, or even 0%, by weight of the composition.

[0027] Generally, as used herein, the term "obtainable by” means that corresponding products do not necessarily have to be produced (i.e. obtained) by the corresponding method or process described in the respective specific context, but also products are comprised which exhibit all features of a product produced (obtained) by said corresponding method or process, wherein said products were actually not produced (obtained) by such method or process. However, the term “obtainable by" also comprises the more limiting term "obtained by”, i.e. products which were actually produced (obtained) by a method or process described in the respective specific context.

[0028] When used herein any definition requiring a compound or a substituent of a compound to consist of "at least a number of carbon atoms", number of carbon atoms refers to the total number of carbon atoms in said compound or substituent of a compound. For example for a substituent disclosed as “alkyl ether with at least 8 carbon atoms comprising alkylene oxide groups”, the total number of at least 8 carbon atoms needs to be the sum of the number of carbon atoms of the alkyl moiety and the number of carbon atoms of the alkylene oxide moieties.

[0029] All such terms not specifically defined have their ordinary meaning as known in the field of organic chemistry.

[0030] As used herein, the articles "a” and "an” when used in a claim or an embodiment, are understood to mean one or more of what is claimed or described. As used herein, the terms “include(s)" and “including" are meant to be non-limiting, and thus encompass more than the specific item mentioned after those words.

[0031] The term "about" as used herein encompasses the exact number "X” mentioned as e.g. "about X%” etc., and small variations of X, including from minus 5 to plus 5 % deviation from X (with X for this calculation set to 100%), preferably from minus 2 to plus 2 %, more preferably from minus 1 to plus 1 %, even more preferably from minus 0.5 to plus 0.5 % and smaller variations. Of course if the value X given itself is already “100%” (such as for purity etc.) then the term "about” clearly can and thus does only mean deviations thereof which are smaller than "100”.

[0032] The term "free of water" means that the composition contains no more than 5 wt.-% of water based on the total amount of solvent, in another embodiment no more than 1 wt.-% of water based on the total amount of solvent, in a further embodiment the solvent contains no water at all.

[0033] All temperatures herein are in degrees Celsius (°C) unless otherwise indicated. Unless otherwise specified, all measurements herein are conducted at 20°C and under the atmospheric pressure. In all embodiments of the present disclosure, all percentages are by weight of the total composition, unless specifically stated otherwise. All ratios are weight ratios, unless specifically stated otherwise.

[0034] Molecular weight descriptors Mw, Mn and polydispersity (PDI as polydispersity index) of the molecular weight; pH-value.

[0035] All percentages given are weight percentages based on the total weight of that composition, dispersion, feed, mixture etc., unless specifically defined otherwise; abbreviated as “wt%”.

[0036] “Bio-degradable”, “biodegradation” with or without the addition of “as tested under standard conditions” mean the biodegradation and - if percentages are given such as “30% bio-degradation / bio-degradable” of the mentioned substance, compound or formulation, which has been determined using biodegradability tests according to OECD301 F (as used in the example section).

[0037] “Medium particle size” and the corresponding “medium particle size measurement” means the particle size D[4,3] as measured using a Malvern Mastersizer 2000 in aqueous environment using standard methods and ingredients. The Mastersizer used for the present invention was equipped with a Hydro 2000S (a) as accessory, using water as dispersant, at a concentration of 0.0220 volume percent.

[0038] “Transmittance of 532nm-wavelength-light” means the transmittance measured with a wave length of 532 nm light using standard machines, such as preferably Hach Lange DR6000 spectrometer, compared to the transmittance of the standard, which usually is plain water suitable for such measurement, preferably being distilled or even bi-distilled water, at a concentration of 0.01 wt.% and a cuvette of 1 centimeter length of dispersion for the rays to pass through.

[0039] “Dust-off' may be determined by a Heubach test for measuring free floating dust and abrasion particles of treated seeds. In the Heubach test, treated seeds are mechanically stressed inside a rotating drum and the amount of dust formed is measured. A vacuum pump creates an air flow through the rotating drum, the connected glass cylinder and the attached filter unit. By the air flow, abraded dust particles are transported out of the rotating drum through the glass cylinder and subsequently through the filter unit. Coarse nonfloating particles are separated and collected in the glass cylinder while floating dust particles are deposited onto a filter. The amount of floating dust collected on the filter is determined gravimetrically.

[0040] The pH value is determined at room temperature (23 °C) and atmospheric pressure.

[0041] Throughout this description, the term “inventive compound” may be used instead of the “inventive (aqueous) dispersion” and “(aqueous) dispersion of this (present) invention”, meaning those compound(s) being disclosed herein as invention, defined by their structure and / or their process to produce and / or obtainable by the process defined herein.

[0042] DETAILED DESCRIPTION OF THE INVENTION

[0043] The specific embodiments as described throughout this disclosure are encompassed by the present invention as part of this invention; the various further options being disclosed in this present specification as “optional”, “preferred”, “more preferred”, “even more preferred” or “most preferred” (or “preferably” etc.) options of a specific embodiment may be individually and independently (unless such independent selection is not possible by virtue of the nature of that feature or if such independent selection is explicitly excluded) selected and then combined within any of the other embodiments (where other such options and preferences can be also selected individually and independently unless such independent selection is not possible by virtue of the nature of that feature or if such independent selection is explicitly excluded), with each and any and all such possible combinations being included as part of this invention as individual embodiments.

[0044] Specifically, this invention relates to a seed coating composition comprising an aqueous polymer dispersion, obtainable by radical aqueous emulsion polymerization as described above

[0045] The aqueous polymer dispersion is obtainable by radical aqueous emulsion polymerization of a mixture comprising a) ethylenically unsaturated monomers M, with M comprising

[0046] (1) at least one vinyl ester M1 , preferably comprising vinyl acetate, more preferably comprising vinyl acetate at least 50%, even more preferably at least 90%, and

[0047] (2) at least one (meth)acrylic acid ester M2 optionally comprising meth-acrylic acid as minor component, the (meth)acrylic acid in the meth-acrylic acid ester being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 2 to 40 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether-function to an 01 to C24, preferably at least C4, more preferably at least 06, even more preferably C8 to 024- aliphatic alkanol, most preferably a 018-aliphatic alkanol, with the AO being preferably selected from EO, PO and / or BuO, more preferably at least EO in an amount of from 50, more preferably at least 75, even more preferably at least 90 wt.% most preferably essentially only EO, based on total AO; preferably comprising methacrylic acid, more preferably with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%;

[0048] (3) optionally further monomers polymerizable with M1 and M2, preferably none; b) 1 to 15, preferably 2 to 10, more preferably 3 to 8, most preferably 4 to 6% by weight, based on the total weight of monomers M, of a carboxyl-groups-containing compound CGCC being selected from a compound bearing in its structure at least three, more preferably at least 6, 8, 10, 15, 20, 25 or more carboxyl-groups of which at least 10 and at most 90 percent are being deprotonated (thus forming salts with counter-ions; the counter-ions being selected from Na, K, NH4, Mg, Ca), selected from the group comprising citric acid, isocitric acid; ethylendiamintetraacetic acid; nitriloacetic acid; tartaric acid; oligomeric and poly-acrylic acid; oligomeric and poly methacrylic acid; trimelitic acid; oligomeric aminoacids with carboxy groups such as polyaspartic acid; oligomeric and poly-glutaminic acid; oligomeric and polyacetates with carboxygroups such as poly(glyoxalic)aldehyde; carboxylated oligomeric and polymeric saccharides such as oxidized starch (mixtures of amylopektines, amylose); polyglucuronates; cellulose oxidized to cellouronate; natural polycarboxylatic polysaccharide such as xylanes; pektines acid; alginic acid; carboxymethylated polysaccharides based on 1 ,4-polyglucanes, 1,3- polyglucanes, 1,6-polyglucanes; Poly-uronic acids based on 1,4-polyglucanes, 1 ,3-polyglucanes, 1,6- polyglucanes; polygalacturonic; preferably carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose (carboxymethylcellulose, “CMC”); and c) at least one (non-carboxylated) sacharide and / or polysaccharide S, such as glucose, starch degradation products, maltodextrin, in an amount of 2 to 50, preferably 5 to 35, more preferably 10 to 30, most preferably 15 to 25 wt% based on the total weight of monomers M; d) at least one emulsifier selected from non-ionic and anionic surfactants, with

[0049] I) the at least one anionic surfactant preferably being selected from: anionic emulsifier bearing at least one anionic group, which is selected from phosphate, phosphonate, sulfate and sulfonate groups; the anionic emulsifier typically employed in the form of their alkali metal salts, especially of their sodium salts or in the form of their ammonium salts; preferably the anionic emulsifier bearing at least one sulfate or sulfonate group or at least one phosphate or phosphonate group, more preferably bearing at least one sulfonate or sulfate group, most preferably only one sulfonate or one sulfate group, i-a) with the anionic emulsifier bearing at least one sulfate or sulfonate group preferably being selected from

[0050] - the salts, especially the alkali metal and ammonium salts, of alkyl sulfates, especially of C8-C22- alkyl sulfates,

[0051] - the salts, especially the alkali metal and ammonium salts, of sulfuric monoesters of C2-C3- alkoxylated alkanols, especially of sulfuric monoesters of C2-C3-alkoxylated C8-C22-alkanols, preferably having an C2-C3-alkoxylation level (AO level) in the range from 2 to 40,

[0052] - the salts, especially the alkali metal and ammonium salts, of sulfuric monoesters of C2-C3- alkoxylated alkylphenols, especially of sulfuric monoesters of C2-C3-alkoxylated C4 C18- alkylphenols (AO level preferably 3 to 40),

[0053] - the salts, especially the alkali metal and ammonium salts, of alkyl-sulfonic acids, especially of C8-C22-alkylsulfonic acids,

[0054] - the salts, especially the alkali metal and ammonium salts, of dialkyl esters, especially di-C4-C18- alkyl esters of sulfosuccinic acid, - the salts, especially the alkali metal and ammonium salts, of alkylbenzenesulfonic acids, especially of C4-C22-alkylbenzenesulfonic acids, and

[0055] - the salts, especially the alkali metal and ammonium salts, of mono- or disulfonated, alkylsubstituted diphenyl ethers, for example of bis(pheny Isu Ifoni c acid) ethers bearing a C4-C24-al ky I group on one or both aromatic rings;

[0056] With the term "C2-C3-alkoxylated” meaning that the compounds are ethoxylated, propoxylated or co- ethoxylated / propoxylated, i.e. meaning that the respective compounds are obtained by a process which introduces a poly-ethylenoxide group, a polypropyleneoxide group or a poly (ethyleneoxide-co- propyleneoxide) group; i-b) With the anionic emulsifier bearing at least one phosphate or phosphonate group, preferably being selected from

[0057] - the salts, especially the alkali metal and ammonium salts, of mono- and dialkyl phosphates, especially C8-C22-alkyl phosphates,

[0058] - the salts, especially the alkali metal and ammonium salts, of phosphoric monoesters of C2-C3- alkoxylated alkanols, preferably having an alkoxylation level in the range from 2 to 40, especially in the range from 3 to 30, for example phosphoric monoesters of ethoxylated C8-C22-alkanols, preferably having an ethoxylation level (EO level) in the range from 2 to 40, phosphoric monoesters of propoxylated C8-C22-alkanols, preferably having a propoxylation level (PO level) in the range from 2 to 40, and phosphoric monoesters of ethoxylated-co-propoxylated C8-C22- alkanols, preferably having an ethoxylation level (EO level) in the range from 1 to 20 and a propoxylation level of 1 to 20,

[0059] - the salts, especially the alkali metal and ammonium salts, of phosphoric monoesters of C2-C3- alkoxylated alkylphenols, especially phosphoric monoesters of C2-C3-alkoxylated C4-C18- alkylphenols (AO level preferably 3 to 40),

[0060] - the salts, especially the alkali metal and ammonium salts, of alkylphosphonic acids, especially C8-C22-alkylphosphonic acids and

[0061] - the salts, especially the alkali metal and ammonium salts, of alkylbenzenephosphonic acids, especially C4-C22-alkylbenzenephosphonic acids; with the more preferred anionic emulsifiers being selected from the following groups:

[0062] - the salts, especially the alkali metal and ammonium salts, of alkyl sulfates, especially of C8-C22- alkyl sulfates,

[0063] - the salts, especially the alkali metal salts, of sulfuric monoesters of C2-C3-alkoxylated alkanols, especially of sulfuric monoesters of C2-C3-alkoxylated C8-C22-alkanols, preferably having an AO level in the range from 2 to 40,

[0064] - of sulfuric monoesters of C2-C3-alkoxylated alkylphenols, especially of sulfuric monoesters of C2-C3-alkoxylated C4-C18-alkylphenols (AO level preferably 3 to 40), - of alkylbenzenesulfonic acids, especially of C4-C22-alkylbenzenesulfonic acids, and

[0065] - of mono- or disulfonated, alkyl-substituted diphenyl ethers, for example of bis(phenyl sulfon ic acid) ethers bearing a C4-C24-alkyl group on one or both aromatic rings; ii) the at least one non-ionic surfactant being selected from: nonionic emulsifiers are e.g. ar-aliphatic or aliphatic nonionic emulsifiers, selected from

[0066] - C2-C3-alkoxylated mono-, di- and trialkylphenols, with the number of repeating units of the alkylene oxide-derived moiety being preferably 3 to 50, and / or the alkyl radical being preferably C4-C10-alkyl;

[0067] - C2-C3-alkyoxlates, such as ethoxylates, propoxylates or ethoxylate-co-propoxylates, of long- chain alcohols with the number of repeating units of the alkylene oxide-derived moiety being preferably 3 to 100, and / or the alkyl radical being preferably C8-C36-alkyl, and

[0068] - polyethylene oxide / polypropylene oxide homo- and copolymers, which may comprise the alkylene oxide units copolymerized in random distribution or in the form of blocks or mixtures of homo-blocks and random-blocks, more preferably C2-C3-alkoxylated of long-chain alkanols, in particular to those where the alkyl radical C8 C30 having a mean alkoxylation level of 5 to 100 and, among these, particular preference to those having a linear C12-C20 alkyl radical and a mean alkoxylation level of 10 to 50, and also to C2-C3-alkoxylated monoalkylphenols; e) optionally sulfate ions; and f) optionally sulfite ions; wherein - preferably - the amount of M1 is from 80 to 99.99 mol%, more preferably the amount of M1 being at least 98%, and the amount of M2 is from 0.01 to 20 mole%, more preferably from 0.1 , even more preferably from 0.2, even more preferably from 0.5, and most preferably from 0.7, and preferably at most 10, even more preferably at most 5, more preferably at most 2%, and most preferably the amount of M1 being about 99 weight percent and the amount of M2 being about 1 weight percent, the total amount of M1 plus M2 being 100 weight percent, and wherein the dispersion has - after the end of the polymerization - a pH of up to 4, more preferably below 4, even more preferably at most 3.8, even more preferably at most 3.6, and more preferably at least 2.5, even more preferably at least 3, even more preferably at least 3.2, and most preferably at least 3.4.

[0069] In a preferred embodiment, the vinyl ester M1 monomer comprises vinyl acetate with at least 50%, even more preferably at least 90% based on the total molar amount of vinyl esters.

[0070] In another preferred embodiment, the least one (meth)acrylic acid ester M2 is a (meth)acrylic acid being bonded via an ether-function to a poly alkylene oxide-derived-block PAO, wherein the PAO consists of 20 to 30 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether-function to an C14 to C22 -aliphatic alkanol, most preferably a C16 / 18-aliphatic alkanol, with the AO being selected from EO and PO and / or BuO, more preferably EO and PO, with the EO in an amount of from 75, even more preferably at least 90 wt.%, most preferably essentially only EO, based on total AO; further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%.

[0071] In a further preferred embodiment, M3 is not comprised.

[0072] In an even more preferred embodiment, in the aqueous polymer dispersion as defined before, the vinyl ester M1 monomer comprises vinyl acetate with at least 50%, even more preferably at least 90% based on the total molar amount of vinyl esters, the least one (meth)acrylic acid ester M2 is a (meth)acrylic acid being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 20 to 30 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether-function to an C14 to C22 -aliphatic alkanol, most preferably a C16 / 18-aliphatic alkanol, with the AO being selected from EO and PO and / or BuO, more preferably EO and PO, with the EO in an amount of from 75, even more preferably at least 90 wt.%, most preferably essentially only EO, based on total AO; further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%, and M3 is not comprised.

[0073] In a further more preferred embodiment, the vinyl ester M1 monomer comprises vinyl acetate with at least 90% based on the total molar amount of vinyl esters, preferably essentially only vinyl acetate, and the least one (meth)acrylic acid ester M2 is a (meth)acrylic acid being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 23 to 27 alkylene oxide AO-units, most preferably on average 25 AO-units, with the PAO preferably being further linked via an ether-function to essentially C16 / 18 -aliphatic alkanol, most preferably a C16 / 18-aliphatic alkanol, with the AO being essentially only EO; further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%, and M3 is not present.

[0074] In a further more preferred embodiment,

[0075] M1 is vinyl acetate, and the least one (meth)acrylic acid ester M2 is a methacrylic acid being bonded via an ether-function to a polyethylene oxide block PEO, wherein the PEO consists of on average 25 AO-units, with the PEO being further linked via an ether-function to a C16 / 18-aliphatic alkanol, further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of about 75 w% / 25w%, and M3 is not present. In a further more preferred embodiment, and preferably in combination with any of the embodiments before, the aqueous polymer dispersion comprises as the CGCC a carboxyl-groups-containing compound being selected from carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose (carboxymethylcellulose, "CMC”), preferably in amounts of from 1 weight % up to 15 weight percent, more preferably up to 10, even more preferably up to 5 wt% and most preferably about 5 weight percent based on the total amount of monomers M1+M2+M3.

[0076] It is believed that the CGCC is able to interact with the polymerized moiety derived from the at least one monomer M2 within the polymer product which is dispersed within the dispersion. By such interaction, an excellent compatibility and stability of the dispersion seems to result; also, such interactions favors the attack at the chemical structure and thus provides the high biodegradation percentage of the aqueous polymer dispersion observed, which is higher than dispersions not containing a carboxyl-groups-containing compound CGCC.

[0077] In one further preferred embodiment, and preferably in combination with any of the embodiments before, the aqueous polymer dispersion comprises at least one saccharide and / or polysaccharide S which is a starch degradation product, preferably a maltodextrin, in an amount of 10 to 30, most preferably 15 to 25 wt% based on the total weight of monomers M

[0078] In a preferred embodiment, S is a degraded starch having a dextrose equivalent according to Lane and Eynon in the range from 2 to 40%.

[0079] In a preferred embodiment, S is maltodextrin with a DE-value of from 10 to 30, preferably 12 to 16 or 25 to 30.

[0080] In a preferred embodiment, S is a degraded starch having a number average molecular weight in the range from 300 to 2000 Dalton, as determined by osmometry, and preferably in a range of from 5 to 150, more preferably up to 70, even more preferably up to 50, and more preferably from 10, even more preferably from 15, and most preferably from 20, each in weight percent based on the total weight of monomers M1+M2+M3.

[0081] Such degraded starches can be obtained by known means, such as chemical degradation, catalytic degradation with suitable catalysts or using enzymes. It is preferred herein, that S stems from an enzymatic degradation as this is a clean and fast approach with basically no chemical residues from the degradation reaction within the degradation products (besides starch and sugars from the starch).

[0082] The use of maltodextrin additionally provides an increased stability at lower temperature of storage for the dispersions. Preferably, the dispersed polymer particles of the aqueous polymer dispersions of this invention have a D[4,3] value as determined by static light scattering of 100 to 1000 nm, preferably 100 to 700 nm, more preferably 100 to 500 nm.

[0083] The aqueous polymer dispersions of any of the embodiments disclosed herein preferably have at least one of the following properties a) to d), preferably at least two, more preferably at least three, and most preferably all of the hereinafter defined properties: a) a transmittance of 532nm-wavelength-light of at least 20% when measured as a 0.01wt% dispersion in water, b) a pH of in between 2.5 and 9, preferably from 3, more preferably from 3.3, and more preferably up to 7, even more preferably up to 6, even more preferably up to 5, and most preferably about 3.5; c) a density of from 1 .04 to 1 .08 g / mL measured as 10wt.%-dispersion (based on solid content), and d) a viscosity of from 30 to 1000 mPas (Brookfield viscosity, spindle 3; measured as 30 wt.%-dispersion containing 30 wt.% active (active = polymer plus CGCC plus S); based on solid content; concentration as applicable by measurement).

[0084] According to a particular embodiment, the seed coating composition comprises at least 0.1% by weight, preferably at least 0.2% by weight, more preferably at least 1% by weight, and in particular at least 5% by weight of the aqueous polymer dispersion, calculated as the solids content thereof.

[0085] According to a further particular embodiment, the coating treatment composition comprises at most 20% by weight, preferably at most 15% by weight, and in particular at most 10% by weight of the aqueous polymer dispersion, calculated as the solids content thereof.

[0086] The aqueous polymer dispersions used herein may be obtained, e.g., in large-scale production, by a process comprising:

[0087] (A) polymerizing ethylenically unsaturated monomers M, with M comprising at least one vinyl ester M1 , preferably comprising vinyl acetate, more preferably comprising vinyl acetate at least 50%, even more preferably at least 90%, and at least one (meth)acrylic acid ester M2, optionally comprising meth-acrylic acid as minor component, the (meth)acrylic acid in the meth-acrylic acid ester being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 2 to 40 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether-function to an C1 to C24, preferably at least C4, more preferably at least C6, even more preferably C8 to C24-aliphatic alkanol, most preferably a C 18-ali phatic alkanol, with the AO being preferably selected from EO, PO and / or BuO, more preferably at least EO in an amount of from 50, more preferably at least 75, even more preferably at least 90 wt.% most preferably essentially only EO, based on total AO; preferably comprising methacrylic acid, more preferably with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%; and optionally further monomers M3 polymerizable with M1 and M2, preferably none; in the presence of

[0088] - at least one emulsifier,

[0089] - water,

[0090] - 1 to 15, preferably 2 to 10, more preferably 3 to 8, most preferably 4 to 6% by weight, based on the total weight of monomers M, of a carboxyl-groups-containing compound CGCC being selected from a compound bearing in its structure at least three, more preferably at least 6, 8, 10, 15, 20, 25 or more carboxyl-groups of which at least 10 and at most 90 percent are being deprotonated (thus forming salts with counter-ions; the counter-ions being selected from Na, K, NH4, Mg, Ca), selected from the group comprising citric acid, isocitric acid; ethylendiamintetraacetic acid; nitriloacetic acid; tartaric acid; oligomeric and polyacrylic acid; oligomeric and poly methacrylic acid; trimelitic acid; oligomeric aminoacids with carboxy groups such as polyaspartic acid; oligomeric and poly-glutaminic acid; oligomeric and polyacetates with carboxygroups such as poly(glyoxalic)aldehyde; carboxylated oligomeric and polymeric saccharides such as oxidized starch (mixtures of amylopektines, amylose); polyglucuronates; cellulose oxidized to cellouronate; natural polycarboxylatic polysaccharide such as xylanes; pektines acid; alginic acid; carboxymethylated polysaccharides based on 1 ,4-polyglucanes, 1,3- polyglucanes, 1,6-polyglucanes; poly-uronic acids based on 1 ,4-polyglucanes, 1,3-polyglucanes, 1,6- polyglucanes; polygalacturonic; preferably carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose (carboxymethylcellulose, “CMC”); and

[0091] - at least one (non-carboxylated) saccharide and / or polysaccharide S, such as glucose, starch degradation products, maltodextrin, in an amount of 2 to 50, preferably 5 to 35, more preferably 10 to 30, most preferably 15 to 25 wt% based on the total weight of monomers M, with the use of at least one radical initiator or a radical initiator couple, such couple preferably comprising a peroxide and a reducing compound; such polymerization being performed

[0092] - in a reaction container equipped with either pressurized equipment and / or equipment to control boiling of the ingredients and with such measure(s) being able to contain the ingredients within the reaction container during the reaction at elevated temperature;

[0093] - at a temperature of from 60 to 90, preferably 70 to 80 °C;

[0094] - at a pH of up to 4, more preferably below 4, even more preferably at most 3.8, even more preferably at most 3.6; with

[0095] (B) optionally adding further radical initiator or initiator couple to further reduce the content of the unreacted monomers and / or to reduce the color of the to be obtained polymer dispersion;

[0096] (C) optionally adding at least one further reducing compound to reduce the color of the to be obtained polymer dispersion, (D) optionally adding at least one further additive that might be needed or desired as additional ingredient within the to be obtained polymer dispersion;

[0097] (E) optionally performing a step of removing evaporable compounds from the reaction mixture by employing a distillation step and / or a stripping step using steam or a gas, preferably steam;

[0098] (F) optionally performing a step of filtrating the polymer dispersion from the previous step, preferably using a 125 micrometer filter; to obtain the aqueous polymer dispersion.

[0099] As a result of the polymerization reaction, the aqueous polymer dispersion may contain sulfite and / or sulfate ions. Those arise mainly from the use of persulfate-radical initiators.

[0100] During the polymerization, the pH-value of the mixture typically decreases due to the formation of acid from the use of the persulfate-initiators. In principle, this decrease of pH can be minimized by adding a base. However, the use of a base is not preferred. The amount of coagulates typically increases the more base is added as the amount of electrolytes increases.

[0101] In preferred embodiment, for the main polymerization step at least one persulfate as radical polymerization initiator and ascorbic acid and / or iso-ascorbic acid are employed

[0102] In preferred embodiment, and preferably in combination with any of the embodiments before, the radical polymerization initiator additionally comprises a transition metal, preferably an iron-containing salt. In the most preferred embodiment, no transition metal is employed. Iron-containing salt are typically complexes of iron-cations, such as complexes with EDTA and the like. Such complexes are known for such applications in combination with persulfate-radical initiators.

[0103] In preferred embodiment, and preferably in combination with any of the embodiments before, in the post polymerization step at least one hydroperoxide and at least one sulfite salt are employed.

[0104] In preferred embodiment, and preferably in combination with any of the embodiments before, at least 5% of the total amount of the hydroperoxide being added in the post polymerization step is added after the end of the addition of the sulfite.

[0105] In preferred embodiment, and preferably in combination with any of the embodiments before, volatile components are removed using steam distillation, thermal distillation, vacuum distillation, gas stripping, to reduce and preferably essentially remove remaining amounts of monomer(s) M1 , and reaction by-products, to a level which is a required level or an acceptable level for the intended area of application, such step being performed at ambient, reduced or over-pressure of at most 2 bar absolute pressure, to reduce the content of the organic solvent(s), residual volatile monomers such as vinyl esters, to a content of at most 1 weight percent, preferably at most 0.5, more preferably at most 0.01 percent, based on the total weight of the aqueous polymer dispersion obtained.

[0106] In preferred embodiment, and preferably in combination with any of the embodiments before, the dispersion finally obtained after the last process step to polymerize and - if employed - to purify is filtered to remove polymer agglomerates of sizes beyond 125 micrometer.

[0107] The aqueous polymer dispersion is suitably biodegradable. Biodegradable materials are broken down by microorganisms, generally in the presence of oxygen (aerobic decomposition), to carbon dioxide, water, biomass and minerals. Biodegradability in terms of the present invention is as determined with one of the methods defined by the European Chemicals Agency (ECHA) in the "Background Document to RAC and SEAC Opinions on Intentionally Added Microplastics” of 11 June 2020, section 2.2.1.6, table 22.

[0108] The aqueous polymer dispersion may be applied in a seed coating composition as obtained from the radical aqueous emulsion polymerization. Preferably, the aqueous polymer dispersion is applied as seed coating composition after dilution with water, i.e. , as a mixture of the aqueous polymer dispersion, as obtained from the radical aqueous emulsion polymerization, with water

[0109] Dilution of the aqueous polymer dispersion with water may further require a dispersant. The further dispersant may also contribute to the dispersion of optional ingredients of the seed coating compositions mentioned in the following, such as pigments. The further dispersant may have the same meaning as the emulsifier d) described above. Alternatively, the further dispersant may be selected from the dispersants as described hereinafter.

[0110] Dispersants suitable as further dispersants are surface-active compounds and can be anionic, cationic, nonionic or amphoteric surfactants, block polymers, polyelectrolytes, and mixtures thereof.

[0111] Suitable anionic dispersants are for example alkali metal, alkaline earth metal or ammonium salts of sulfonates, sulfates, phosphates, carboxylates, and mixtures thereof. Examples of sulfonates are alkylarylsulfonates, diphenylsulfonates, alpha-olefin sulfonates, lignin sulfonates, sulfonates of fatty acids and oils, sulfonates of ethoxylated alkylphenols, sulfonates of alkoxylated arylphenols, sulfonates of condensed naphthalenes, sulfonates of dodecyl- and tridecyl benzenes, sulfonates of naphthalenes and alkyhnaphthalenes, sulfosuccinates or sulfosuccinamates. Examples of sulfates are sulfates of fatty acids and oils, of ethoxylated alkylphenols, of alcohols, of ethoxylated alcohols, or of fatty acid esters. Examples of phosphates are phosphate esters. Examples of carboxylates are alkyl carboxylates, and carboxylated alcohol or alkylphenol ethoxylates. Suitable nonionic dispersants are for example al koxylate surfactants, N-substituted fatty acid amides, amine oxides, esters, sugar-based surfactants, polymeric surfactants, and mixtures thereof. Examples of alkoxylate surfactants are compounds such as alcohols, alkylphenols, amines, amides, arylphenols, fatty acids or fatty acid esters which have been alkoxylated with 1 to 50 equivalents of alkylene oxide(s). Ethylene oxide and / or propylene oxide may be employed for the alkoxylation, ethylene oxide being preferably used. Examples of N-substituted fatty acid amides are fatty acid glucamides or fatty acid alkanolamides. Examples of esters are fatty acid esters, glycerol esters or monoglycerides. Examples of sugar-based surfactants are sorbitans, ethoxylated sorbitans, sucrose and glucose esters or alkylpolyglucosides. Examples of polymeric surfactants are homo- or copolymers of vinylpyrrolidone, vinylalcohols, or vinylacetate.

[0112] Suitable cationic dispersants are for example quaternary surfactants, for example quaternary ammonium compounds with one or two hydrophobic groups, or salts of long-chain primary amines.

[0113] Suitable amphoteric dispersants are for example alkylbetains and imidazolines.

[0114] Suitable block polymers are for example block polymers of the A-B or A-B-A type comprising blocks of polyethylene oxide and polypropylene oxide, or of the A-B-C type comprising alkanol, polyethylene oxide and polypropylene oxide.

[0115] Polyelectrolytes are water-soluble polymeric compounds carrying functional groups which can dissociate or undergo addition reactions (mostly protonation) to give anionic or cationic groups. Polymers carrying anionic groups are typically derived from poly acids, and polymers carrying cationic groups are typically derived from polybases. Strong polyelectrolytes carry a permanent charge that is independent of the pH of the solution, whereas in weak polyelectrolytes, the degree of dissociation depends on the pH of the solution. Suitable polyelectrolytes are for example polyacids (anionic copolymer electrolyte) or polybases (cationic copolymer electrolyte). Examples of polyacids are polycarboxylic acids, such as polyacrylic acid, acrylic acid copolymers, maleic acid or maleic acid anhydride homo- or copolymers, or polyacid comb polymers; acrylamide copolymers, lignosulfonates, polyvinylsulfuric acids, polystyrene sulfonic acids, polyphosphoric acids etc. and alkali metal or ammonium salts thereof. Examples of polybases are polyvinylamines or polyethyleneimines.

[0116] In a particular embodiment, an anionic copolymer electrolyte or a non-ionic polyalkyleneglycol ester is used as the further dispersant. Non-ionic polyalkyleneglycol esters are formally obtained by alkoxylating acids or acid esters, e.g. fatty acids orfatty acid esters, with one or more alkylene oxides, e.g. with 1 to 50 equivalents of alkylene oxide(s). Ethylene oxide and / or propylene oxide are generally employed for the alkoxylation, ethylene oxide being preferably used. Among the anionic copolymer electrolytes, preference is given to polycarboxylic acids, such as polyacrylic acid, acrylic acid copolymers, maleic acid or, in particular, maleic acid anhydride homo- or copolymers. In a preferred embodiment, the composition additionally comprises at least one pigment.

[0117] Suitable pigments are all those customarily used for seed dying. Pigments are colorants of no or low watersolubility, and can be inorganic or organic. Non-exhaustive examples for inorganic pigments are titanium dioxide, carbon black, bismuth pigments, silicates (e.g. mica, talc), metal oxides and hydroxides, such as iron oxide pigments, chromium oxide and mixed phase oxide pigments, e.g. Rinman's green; iron cyan blue, ultramarine, cadmium pigments, and chromate pigments, such as chrome yellow, chrome green, and molybdates. Non-exhaustive examples for organic pigments are pigments of the azo type (generally monoazo or diazo pigments), polycyclic pigments, such as phthaloycyanins (especially Cu phthalocycanins), quinacridones, diketopyrrolopyrrole pigments, dioxazines, perylenes, isoindolines or inthanthrones; and alizarin pigments. More specific examples for organic pigments are the various Pigment Yellow, Pigment Orange, Pigment Red, Pigment Violet, Pigment Blue, Pigment Green products. Mixtures of different pigments, e.g. mixtures of 2, 3, 4, 5, 6, 7, 8 or more different pigments, can be used as pigment in the composition.

[0118] The pigments are commercially available or can be prepared by methods known in the art.

[0119] The nature of the pigment is not critical (as far as it is suitable in seed coating), since the aqueous polymer dispersion works well as a binder for all kind of types of both inorganic and organic pigments.

[0120] Some of the above-mentioned pigments, especially the inorganic ones, e.g. the silicate types (e.g. mica, talc) or carbon black, may also serve as a filler.

[0121] If the composition comprises at least one pigment, the total amount of the aqueous polymer dispersion, calculated as the solids content thereof, and the at least one pigment is preferably in the range of 10 to 82% by weight, e.g. from 30 to 75% by weight or from 35 to 70% by weight; based on the total weight of the composition.

[0122] The overall weight ratio of the aqueous polymer dispersion and the at least one pigment is preferably of from 1 :1 to 1 :20, more preferably from 1 :2 to 1 :15, in particular from 1 :2 to 1 : 12, especially from 1 :4 to 1 : 10.

[0123] The composition may comprise at least one further additive. Typically, such additional additives are antifreezing agents, antifoaming agents, rheology modifiers, fillers, preservatives and mixtures thereof.

[0124] Examples for anti-freezing agents are ethylene glycol, propylene glycol, 1 ,3-butylene glycol, hexylene glycol, diethylene glycol, glycerin, urea and glycerin. Examples for antifoaming agents are siloxanes, silicones, long chain alcohols, polyethylene glycol, glycerin and salts of fatty acids.

[0125] Examples for rheology modifiers (thickeners) are polysaccharides (e.g. xanthan gum, agar, carrageenan, carboxymethylcellulose, gum arabic and the like), inorganic clays (organically modified or unmodified; e.g. bentonite), polycarboxylates and silicates. The rheology modifier is preferably a polysaccharide, in particular xanthan gum.

[0126] Suitable fillers or carriers are expediently solid. Examples for solid carriers or fillers are mineral earths, e.g. silicates, silica gels, talc, kaolins, lime-stone, lime, chalk, clays, dolomite, diatomaceous earth, bentonite, calcium sulfate, magnesium sulfate, magnesium oxide; polysaccharide powders, e.g. cellulose, starch; fertilizers, e.g. ammonium sulfate, ammonium phosphate, ammonium nitrate, ureas; products of vegetable origin, e.g. cereal meal, tree bark meal, wood meal or nutshell meal; and mixtures thereof. As mentioned above, some filler also have pigment properties, e.g. certain silicates, such as mica.

[0127] Examples for preservatives are 2-phenoxyethanol, phenoxyisopropanol, 4,4'-dichloro 2'- hydroxydiphenylether (diclosan), triclosan, 2-bromo-2-nitropropane-1,3-diol (bronopol), glutaraldehyde, 2,4- dichlorobenzylalcohol, 1 ,3,5-tris-(2-hydroxyethyl)-1 ,3,5-hexahydrotriazine, formic acid and salts thereof, benzoic acid and salts thereof, sorbic acid and salts thereof, lactic acid and salts thereof, isothiazolinones, such as 1,2-benzisothiazol-3(2H)-one (BIT), 2-methyl-2H-isothiazol-3-one (MIT), 2-octyl-2H-isothiazol-3- one (OIT), 5-chloro-2-methyl-2H-isothiazol-3-one (CMIT), and 2-butyl-benzo[d]isothiazol-3-one (BBIT); and mixtures thereof.

[0128] In case that the composition comprises at least one pigment, the composition preferably comprises:

[0129] (a) from 2 to 30% by weight, relative to the total weight of the composition, of the aqueous polymer dispersion, calculated as the solids content thereof;

[0130] (b) from 0.01 to 10% by weight, relative to the total weight of the composition, of the at least one dispersant; from 10 to 80% by weight, relative to the total weight of the composition, of the at least one pigment;

[0131] (d) from 0 to 15% by weight, relative to the total weight of the composition, of the at least one rheology modifier;

[0132] (e) from 0 to 50% by weight, relative to the total weight of the composition, of the at least one further additive (if the further additive comprises a filler with pigment properties, the amount of the latter is counted as belonging to the 10-80% of the pigment, and (e) comprises in this case 0-30% by weight of the at least one further additive); and

[0133] (f) water ad 100% by weight. More preferably, the composition comprises

[0134] (a) from 3 to 20% by weight, relative to the total weight of the composition, of the aqueous polymer dispersion, calculated as the solids content thereof;

[0135] (b) from 0.1 to 5% by weight, relative to the total weight of the composition, of the at least one dispersant; from 10 to 70% by weight, relative to the total weight of the composition, of the at least one pigment;

[0136] (d) from 0 to 10% by weight (e.g. 0.01 to 10% by weight), relative to the total weight of the composition, of the at least one rheology modifier;

[0137] (e) from 0.1 to 40% by weight, relative to the total weight of the composition, of the at least one further additive (if the further additive comprises a filler with pigment properties, the amount of the latter is counted as belonging to the 10-70% of the pigment, and (e) comprises in this case 0-20% by weight of the at least one further additive); and

[0138] (f) water ad 100% by weight.

[0139] In particular, the composition comprises

[0140] (a) from 3 to 15% by weight, relative to the total weight of the composition, of the aqueous polymer dispersion, calculated as the solids content thereof;

[0141] (b) from 0.1 to 3% by weight, relative to the total weight of the composition, of the at least one dispersant; from 10 to 60% by weight, relative to the total weight of the composition, of the at least one pigment;

[0142] (d) from 0 to 1% by weight (e.g 0.01 to 1% by weight), relative to the total weight of the composition, of the at least one rheology modifier;

[0143] (e) from 0.1 to 30% by weight, relative to the total weight of the composition, of the at least one further additive (if the further additive comprises a filler with pigment properties, the amount of the latter is counted as belonging to the 10-60% of the pigment, and (e) comprises in this case 0.1-15% by weight of the at least one further additive); and

[0144] (f) water ad 100% by weight.

[0145] The above-described composition may be prepared by mixing the single components with each other or by providing premixes of a part of the components and mixing either with the remaining individual components or with the remaining individual components in form one or more premixes. If desired or necessary, the obtained composition may be diluted with water to the desired concentration.

[0146] The invention relates also to the use of the aqueous polymer dispersion for coating seeds, and to a method for coating seeds comprising applying said composition to the seeds.

[0147] The invention relates moreover to a coated seed, obtainable by the coating of the seed with an composition.

[0148] The invention relates further to a coated seed, comprising a layer coating a part or the complete surface of the seed, wherein the layer is formed from the seed coating composition. Preferably, the thickness of said layer formed from the composition and the at least one pigment is such that it does not modify the shape or size of the seed perceptibly, i.e. the composition-comprising layer is a thin film.

[0149] Preferably, the coated seed comprises at most 0.1% by weight, e.g. from 0.008 to 0.1% by weight, more preferably at most 0.07% by weight, e.g. from 0.01 to 0.07% by weight, even more preferably at most 0.05% by weight, e.g. from 0.01 to 0.05% by weight, particularly preferably at most 0.04% by weight, e.g. from 0.01 to 0.04% by weight, of the aqueous polymer dispersion, calculated as the solids content thereof, relative to the weight of uncoated seed.

[0150] The seed can be of any kind of agronomic importance which is typically dyed. Non exhaustive examples are cereal seeds, such as wheat, rye, triticale, oats, barley, sorghum / millet, spelt or rice seeds; corn (maize) seeds, rapeseed / canola seeds, soybean seeds, sunflower seeds, grass seeds, lawn seeds, turf seeds, forage plant (i.e. for grazing pasture, hay production, silage and green-chop) seeds, mustard seeds, alfalfa seeds, clover seeds, pea seeds, cowpea seeds, bean seeds, mungbean seeds, lentil seeds, lupin seeds, pumpkin / squash seeds, zucchini seeds, eggplant seeds, cucumber seeds, melon seeds, e g. of watermelon or honeydew melon, onion seeds, garlic seeds, carrot seeds, tomato seeds, pepper seeds, sugar beet seeds, fodder beet seeds, lettuce seeds, spinach seeds, leek seeds, potato tubers, cotton seeds, Brassica species seeds, tobacco seeds.

[0151] Preferably, the seeds are cereal seeds, such as wheat, rye, triticale, oats, barley, sorghum / millet, spelt or rice seeds; corn (maize) seeds, rapeseed / canola seeds, soybean seeds or sunflower seeds.

[0152] The seeds can also be seeds which have genetically modified traits.

[0153] The coated seed is obtainable by the coating of the seed with the composition. Details with respect to the coating are given in context with the method for preparing a coated seed described in the following.

[0154] A method for preparing a coated seed as defined above comprises contacting a part or the complete seed to be coated with the composition.

[0155] The seed may be coated with said composition by applying it to the seed. Coating may be carried out by suitable seed coating techniques known in the art, such as seed dressing, seed coating, seed encrusting, seed pelleting or seed soaking, where the seeds are dipped into or soaked in or rolled in or shaken with said compositions or the compositions are sprayed, scattered, brushed or coated on the seeds. Preferably, the seed coating technique is neither seed encrusting nor seed pelleting. Preferably, the seed coating technique is selected from those which result in the formation of thin films, such as seed dressing and seed coating. Before coating the seeds with said compositions, the latter may be diluted if desired.

[0156] Apparatuses for carrying out the method are well known in the art. If the compositions do not contain any hazardous material, a simple cement mixer, a seed treater, such as a Hege® seed treatment apparatus, a downstream continuous flow seed treatment equipment or on-farm seed treatment equipment can for example be used, while specialist machinery is required for hazardous coating materials.

[0157] If the composition contains one or more pigments, the resulting seed contains the pigments and the aqueous polymer dispersion in one layer.

[0158] The invention also relates to the use of the aqueous polymer dispersion as a binder for pigments in seed coating compositions.

[0159] Since the aqueous polymer dispersion is suitably biodegradable, seeds coated with a layer containing the aqueous polymer dispersion have a reduced environmental impact. Moreover, the seeds coated therewith have a reduced dust formation, thusly also reducing the environmental impact in this respect and also reducing the health risks for humans and animals coming into contact with the coated seeds and dust produced therefrom, e g. during sowing, or during transport, packaging, processing etc Advantageously, the coated seeds are not sticky, and thus dust suppression is not to the expense of the flowability of the coated seeds, and the coated seeds show good sowability / plantability.

[0160] The invention is illustrated by the following examples.

[0161] Examples

[0162] A. Aqueous Polymer Dispersions

[0163] Aqueous polymer dispersions 1 and 2 were prepared as follows. The individual amounts of the components are indicated in the tables below.

[0164] A 4 L glass reactor (temperature control, anchor stirrer and reflux condenser under nitrogen gas atmosphere) was precharged with a solution of sodium acetate, carboxymethyl cellulose (Finnfix 10, CP Kelco) and 95 wt.-% maltodextrin with a dextrose equivalent of 10 (CDry MD01910, Cargill) in demineralized water. The mixture was heated to 70 °C while stirring at 120 rpm to obtain a transparent solution.

[0165] In a second glass reactor, an emulsion was prepared. Emulsifiers in accordance with the tables below, such as lauryl ether sulfate (Disponil FES 27, BASF), alkyldiphenyloxide disulfonate (Dowfax 2A1 , Dow) or sodium octyl succinic acid (Lumiten I - SC, BASF), were dissolved in water and a mixture of vinyl acetate, vinyl laurate and methacrylic acid ester-PEG C18 (Visiomer C18 PEG 1105, Evonik) were added dropwise. A stable emulsion was obtained (Feed 1). Optionally, 2-ethylhexyl-thioglycolate was added.

[0166] As a first initiator redox system, separate solutions of 7 wt.-% of sodium persulfate in water (Feed 2) and 2 wt.-% of ascorbic acid (Lutavit C) in water (Feed 3) were provided. To initiate the reaction, 5 wt.-% of the total amount of Feed 1 was added to the precharge at 70 °C and stirred for 5 min. Feed 2 and Feed 3 were dosed in simultaneously. The total dosing time of Feed 2 and Feed 3 was 255 min. 15 min after starting the dosing in of Feed 2 and 3, the remaining Feed 1 was dosed in over a period of 210 min.

[0167] A second redox initiator system was used to reduce the residual monomer content. For this second redox initiator system, a 10.0 wt.-% tert-butyl hydroperoxide solution in water (Feed 4) and a 2.5 wt.-% acetone bisulfite solution (Feed 5) were provided. Feed 5 was obtained as follows: 7.62 g sodium disulfite (N32S2O5) were dissolved in 87.6 g deionized water (Mixture A). 95.22 g aqueous NaHSOs (8.8 wt.-%) and 4.78 g acetone were mixed (Mixture B). Mixtures A and B were mixed to obtain 100.00 g acetone bisulfite solution (13.1 wt-%), which was diluted with water to obtain a 2.5 wt.-% acetone bisulfite solution (Feed 5)

[0168] After Feeds 1 , 2 and 3 were dosed in, the tert-butyl hydroperoxide solution (Feed 4) was added. Subsequently, the acetone bisulfite solution (Feed 5) was dosed in over the course of 30 min Then, a small amount of a 15 wt.-% of hydrogen peroxide solution in water (Feed 6) was added to achieve a white color lasting dispersion. The residual monomer content of vinyl acetate was found to be less than 300 ppm. The acetaldehyde content was less than 800 ppm. Residual monomer contents were measured by gas chromatography against calibrated standards.

[0169] After cooling to 25 °C, the dispersion was filtered with a nylon filter (125 pm).

[0170] Table: Feed Compositions of Aqueous Polymer Dispersions 1 and 2

[0171] The table below shows the concentrations of the components of aqueous polymer dispersions 1 and 2 in parts per hundred million (pphm), as well as the characteristics of aqueous polymer dispersions 1 and 2. The aqueous polymer dispersions were characterized by total solids content, transmittance of 532-nm wavelength-light, pH value (determined at room temperature, i.e. 23 °C, and atmospheric pressure), the amount of coagulum remaining in the filter (determined by washing the filter with water and comparing the weight before and after filtration), and the particle size distribution Dso (determined in accordance with ISO 13320:2009). “Transmittance of 532nm-wavelength-light” means the transmittance measured with a wave length of 532 nm light using standard machines, such as preferably Hach Lange DR6000 spectrometer, compared to the transmittance of the standard, which usually is plain water suitable for such measurement, preferably being distilled or even bi-distilled water, at a concentration of 0.01 wt.% and a cuvette of 1 centimeter length of dispersion for the rays to pass through. Table: Composition (Solids Content) and Characteristics of Aqueous Polymer Dispersions 1 and 2 B. Aqueous Seed Coating Composition

[0172] From aqueous polymer dispersions 1 and 2, seed coating compositions 1 and 2 having a composition as shown in the following table were prepared.

[0173] C. Application Examples

[0174] The obtained seed coating compositions 1 and 2 were applied to corn at a use rate of 326 mL / 100 kg and in combination with a proprietary seed treatment package. The results were compared to a "blank” composition in which the aqueous polymer dispersion was replaced by water in the seed coating composition. The blank composition was applied to corn at the same use rate as mentioned above with the same seed treatment package.

[0175] D. Method for Determining Dust-Off - Heubach Test

[0176] Seed dust-off was measured using a Heubach dustmeter. The Heubach test was performed following industry standards - the ESA reference method "Assessment of free floating dust and abrasion particles of treated seeds as a parameter of the quality of treated seeds". In this test, 100 g of treated seeds that had been allowed to dry for at least five days were placed in the metal drum of the Heubach Dustmeter device (from Heubach GmbH, Germany), which is then closed and connected to a glass cylinder. A glass fiber filter is placed in the filter unit, which is weighed before and after the test is performed. The filter unit is connected to the glass cylinder and a vacuum tube. The run is performed for 120 s, at a rotation speed of 30 rpm and a flow rate of 20 L / min. The filter weight was collected before and after the process to quantify the dust generated by the seeds. This process was performed in duplicates. The average dust value is reported as the amount of dust in g released per 100,000 seeds.

[0177] E. Application Examples

[0178] Corn seeds treated with seed coating compositions 1 and 2 were subjected to the above-described Heubach dust test. For comparative purposes, corn seeds treated with the above-described blank composition were also subjected to the above-described Heubach dust test. The results are compiled in the following table.

[0179] ‘comparative example

[0180] It is evident that the seed coating composition of the invention allows for reduced dust-off.

Claims

Claims1. A seed coating composition comprising an aqueous polymer dispersion, obtainable by radical aqueous emulsion polymerization of a mixture comprising a) ethylenically unsaturated monomers M, with M comprising(1) at least one vinyl ester M1 , preferably comprising vinyl acetate, more preferably comprising vinyl acetate at least 50%, and(2) at least one (meth)acrylic acid ester M2 optionally comprising methacrylic acid as minor component, the (meth)acrylic acid in the methacrylic acid ester being bonded via an ether- function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 2 to40 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether-function to an 01 to 024, preferably at least 04, more preferably at least 06, even more preferably 08 to 024-aliphatic alkanol, most preferably a 018-aliphatic alkanol, with the AO being preferably selected from EO, PO and / or BuO, more preferably at least EO in an amount of from 50, more preferably at least 75, even more preferably at least 90 wt.% most preferably essentially only EO, based on total AO; preferably comprising methacrylic acid, more preferably with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%;(3) optionally further monomers M3 polymerizable with M1 and M2, preferably none; b) 1 to 15, preferably 2 to 10%, based on the total weight of monomers M, of a carboxyl-groups- containing compound CGCC being selected from a compound bearing in its structure at least three carboxyl-groups of which at least 10 and at most 90 percent are being deprotonated, selected from the group comprising citric acid, isocitric acid; ethylendiamintetraacetic acid; nitriloacetic acid; tartaric acid; oligomeric and polyacrylic acid; oligomeric and poly methacrylic acid; trimelitic acid; oligomeric aminoacids with carboxy groups such as polyaspartic acid; oligomeric and polyglutaminic acid; oligomeric and polyacetates with carboxygroups such as poly(glyoxalic)aldehyde; carboxylated oligomeric and polymeric saccharides such as oxidized starch (mixtures of amylopektines, amylose); polyglucuronates; cellulose oxidized to cellouronate; natural polycarboxylatic polysaccharide such as xylanes; pektines acid; alginic acid; carboxymethylated polysaccharides based on 1,4-polyglucanes, 1 ,3-polyglucanes, 1 ,6-polyglucanes; Poly-uronic acids based on 1 ,4-polyglucanes, 1 ,3-polyglucanes,1 ,6-polyglucanes; polygalacturonic; preferably carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose; c) at least one non-carboxylated saccharide and / or polysaccharide S, such as glucose, starch degradation products, maltodextrin, in an amount of 2 to 50, preferably 5 to 35wt% based on the total weight of monomers M; d) at least one emulsifier selected from non-ionic and anionic surfactants; e) optionally sulfate ions; andf) optionally sulfite ions; wherein - preferably - the amount of M1 is from 80 to 99.99 mol%, and the amount of M2 is from 0.01 to 20 mole%, and preferably at most 10, even more preferably at most 5, more preferably at most 2%, the total amount of M1 plus M2 being 100 weight percent, and wherein the dispersion has - after the end of the polymerization - a pH of up to 4.

2. The composition according to claim 1, wherein the vinyl ester M1 monomer comprises vinyl acetate with at least 50%, even more preferably at least 90% based on the total molar amount of vinyl esters, and the least one (meth)acrylic acid ester M2 is a (meth)acrylic acid being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 20 to 30 alkylene oxide AO-units, most preferably 25 AO-units, with the PAO preferably being further linked via an ether- function to an C14 to C22 -aliphatic alkanol, most preferably a C16 / 18-aliphatic alkanol, with the AO being selected from EO and PO and / or BuO, more preferably EO and PO, with the EO in an amount of from 75, even more preferably at least 90 wt.%, most preferably essentially only EO, based on total AO; further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%; and M3 being not comprised.

3. The composition according to claim 2, wherein the vinyl ester M1 monomer comprises vinyl acetate with at least 90% based on the total molar amount of vinyl esters, preferably essentially only vinyl acetate, and the least one (meth)acrylic acid ester M2 is a (meth)acryl ic acid being bonded via an ether-function to a polyalkylene oxide-derived-block PAO, wherein the PAO consists of 23 to 27 alkylene oxide AO-units, most preferably on average 25 AO-units, with the PAO preferably being further linked via an ether-function to essentially C16 / 18-aliphatic alkanol, most preferably a C16 / 18-aliphatic alkanol, with the AO being essentially only EO; further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of from about 70 w% / 30w% to 80 w% / 20w%, more preferably about 75 w% / 25w%.

4. The composition according to claim 3, whereinM1 is vinyl acetate, and the least one (meth)acrylic acid ester M2 is a methacrylic acid being bonded via an ether-function to a polyethylene oxide block PEO, wherein the PEO consists of on average 25 AO-units, with the PEO being further linked via an ether-function to a C16 / 18-aliphatic alkanol, further comprising methacrylic acid, with the methacrylic acid ester and the free methacrylic acid being in a ratio of about 75 w% / 25w%.

5. The composition according to any of the preceding claims, wherein the CGCC is a carboxyl-groups-containing compound being selected from carboxylated polysaccharides, more preferably carboxylated cellulose, even more preferably carboxylated methylcellulose, preferably in amounts of 2.5 to 10 most preferably about 5 weight percent based on the total amount of monomers M1+M2+M3.

6. The composition according to any of the preceding claims, wherein the dispersed polymer particles have a D[4,3] value as determined by static light scattering of at least 100 and up to 1000 nm.

7. The composition according to any of the preceding claims, wherein at least one saccharide and / or polysaccharide S is a starch degradation product, preferably a maltodextrin, in an amount of 10 to 30, preferably 15 to 25 wt%, more preferably 17 to 23 wt%, based on the total weight of monomers M.

8. The composition according to claim 7, wherein S is a degraded starch having a dextrose equivalent according to Lane and Eynon in the range from 2 to 40%.

9. The composition according to any of the preceding claims, wherein as compound S a degraded starch is employed having a number average molecular weight in the range from 300 to 2000 Dalton, as determined by osmometry, and preferably in a range of from 5 to 150, more preferably up to 70, even more preferably up to 50, and more preferably from 10, even more preferably from 15, and most preferably from 20, each in weight percent based on the total weight of monomers M1 +M2+M3.

10. The composition according to any of the preceding claims, further comprising a dispersant, wherein the dispersant is preferably selected from anionic copolymer electrolytes and non-ionic polyalkyleneglycol esters.

11. The composition according to any of the preceding claims, further comprising at least one pigment.

12. The composition according to claim 11, wherein one or both of the following conditions apply:- the total amount of the aqueous polymer dispersion, calculated as the solids content thereof, and the at least one pigment is in the range of 10 to 82% by weight, based on the total weight of the composition; and / or- the overall weight ratio of the aqueous polymer dispersion, calculated as the solids content thereof, and the at least one pigment is of from 1 :1 to 1 :20, preferably from 1 :2 to 1 : 15, more preferably from 1 :2 to 1 :12.

13. The composition according to any of the preceding claims, additionally comprising at least one further additive selected from the group consisting of antifreezing agents, antifoaming agents, rheology modifiers, fillers, preservatives and mixtures thereof.

14. The composition according to any of claims 11 to 13, comprising(a) from 2 to 30% by weight, preferably from 3 to 20% by weight and in particular from 3 to 15% by weight, relative to the total weight of the composition, of the aqueous polymer dispersion, calculated as the solids content thereof;(b) from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight and in particular from 0.1 to 3% by weight, relative to the total weight of the composition, of the at least one dispersant;(c.1 ) from 10 to 80% by weight, preferably from 10 to 70% by weight and in particular from 10 to 60% by weight, relative to the total weight of the composition, of the at least one pigment;(d) from 0 to 15% by weight, preferably from 0.01 to 10% by weight and in particular from 0.01 to 1% by weight, relative to the total weight of the composition, of the at least one rheology modifier;(e) from 0 to 50% by weight, preferably from 0.1 to 40% by weight and in particular from 0 1 to 30% by weight, relative to the total weight of the composition, of the at least one further additive; and(f) water ad 100% by weight.

15. The use of the aqueous polymer dispersion as defined in any of claims 1 to 9 for coating seeds.

16. A coated seed, obtainable by coating the seed with the seed coating composition as defined in any of claims 1 to 14.

17. A coated seed, comprising a layer coating a part or the complete surface of the seed, wherein the layer is formed from the seed coating composition as defined in any of claims 1 to 14, and at least one pigment; wherein the coated seed preferably comprises at most 0.1 % by weight, more preferably at most 0.05% by weight, even more preferably at most 0.04% by weight of the aqueous polymer dispersion, calculated as the solids content thereof, relative to the weight of uncoated seed.

18. A method for preparing a coated seed as defined in claim 17, comprising contacting a part or the complete seed to be coated with the seed coating composition as defined in any of claims 1 to 14.

19. The use of the aqueous polymer dispersion as defined in any of claims 1 to 9 as a binder for pigments seed in seed coating compositions.

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