WO2017187994A1

WO2017187994A1 - Seed coating material

Info

Publication number: WO2017187994A1
Application number: PCT/JP2017/015053
Authority: WO
Inventors: 正昭一柳
Original assignee: 住化農業資材株式会社
Priority date: 2016-04-28
Filing date: 2017-04-13
Publication date: 2017-11-02
Also published as: CN108471708B; CN108471708A; JP5995340B1; JP2017195837A

Abstract

This water-dispersible seed coating material is characterized by comprising titanium oxide, talc, polyvinyl alcohol, and an ethylene-vinyl acetate copolymer, and in that the seed coating material, which contains water, has a titanium oxide content of 10-40% by mass, a titanium oxide-to-talc weight ratio of 3:1 to 0.5:1, and a PVA-to-EVA weight ratio of 3:1 to 0.5:1. This reduces precipitation of titanium oxide during storage and results in excellent redispersibility. The seed coating material is less likely to cause seeds to attach to each other or to a processing tank during coating processing, and the color of coated seeds is good and not affected by the seed coat color. The coating layers do not peel away from the seeds, and there is no adverse effect on the germination performance.

Description

Seed coating material

The present invention relates to a seed coating material, and more particularly to a water-suspendable seed coating material.

¡Seed type and variety may be difficult to distinguish from the seed shape. Therefore, coloring seeds to facilitate identification of seed type and variety. A suspension coating material containing titanium oxide and a polymer has been used as a coating material for coloring seeds.

Titanium oxide is a material with excellent concealability, and can be used in combination with other pigments as necessary to eliminate the effect of seed coat color and to give the seeds an excellent color. it can.

However, a suspension coating material (suspension) containing a polymer and titanium oxide is highly sticky, and when seeds are coated, the seeds adhere to each other, or the seeds adhere to the processing tank. There was a problem. In addition, titanium oxide settles during storage of the suspension to form a hard precipitate layer, which cannot be easily resuspended.

Therefore, for example, Patent Document 1 proposes a seed coating material using titanium oxide surface-treated with aluminum oxide, silicon dioxide or the like. And according to such surface-treated titanium oxide, it is said that there is little precipitate even if it is stored for a long time, and it is excellent in redispersibility.

Patent Document 2 proposes a seed coating material containing a predetermined amount or more of inorganic fine particles having an average particle diameter of 250 μm or less. And according to this seed coating | covering material, it is supposed that adhesion | attachment between the seeds during a coating process and adhesion to a seed and a processing apparatus will be suppressed.

Japanese Patent Laid-Open No. 11-146707 US Patent Application Publication No. 2012/0065060

However, with the proposed technique of Patent Document 1, there is a possibility that adhesion between seeds or adhesion to a processing apparatus cannot be sufficiently suppressed. Moreover, in the proposal technique of patent document 2, the case where the density | concentration of a titanium oxide is made high is not assumed, and the precipitation of the titanium oxide by long-term storage is not considered.

Accordingly, an object of the present invention is to provide a seed coating material containing titanium oxide, which has excellent dispersibility of titanium oxide and does not form a hard precipitation layer during storage, and also prevents adhesion between seeds during coating processing. To provide a coating material that has little adhesion to the processing tank, the color of the coated seed is good without being affected by the seed coat color, does not peel off from the seed, and does not adversely affect the germination performance. is there.

According to the present invention, it contains titanium oxide, talc, polyvinyl alcohol (hereinafter sometimes referred to as “PVA”), and an ethylene / vinyl acetate copolymer (hereinafter sometimes referred to as “EVA”). The content of titanium oxide in the seed coating material containing water is 10% by mass or more and 40% by mass or less, the weight ratio of titanium oxide: talc is 3: 1 to 0.5: 1, and the weight of PVA: EVA A water-suspendable seed coating material characterized in that the ratio is 3: 1 to 0.5: 1 is provided. In the present specification, unless otherwise specified, “˜” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.

In the seed coating material having the above structure, the mass average particle diameter of titanium oxide is preferably 0.1 μm or more and 1 μm or less. In the present specification, the “mass average particle diameter” is a particle diameter measured using a laser diffraction particle size distribution analyzer, and may be referred to as “average particle diameter” hereinafter.

In the seed coating material having the above-described configuration, the mass average particle diameter of talc is preferably 0.1 μm or more and 20 μm or less.

Further, according to the present invention, there is provided a seed characterized in that the surface is coated with the seed coating material described above.

According to the seed coating material of the present invention, there are few precipitates of titanium oxide during storage and excellent redispersibility. Moreover, there is little adhesion between seeds and the processing tank during the coating process, and the color of the coated seed is good without being affected by the seed coat color. No peeling of the coating layer from the seed occurs, and there is no adverse effect on germination performance.

One of the major features of the present invention is that it contains 10% by mass or more and 40% by mass or less of titanium oxide in a seed coating material containing water. By setting the content of titanium oxide within this range, the entire seed surface can be satisfactorily coated with titanium oxide, and the seed can be colored in a desired color without being affected by the seed coat color. A more preferable content of titanium oxide is 10% by mass or more and 30% by mass or less.

It is also important that the weight ratio of titanium oxide: talc is 3: 1 to 0.5: 1. By containing titanium oxide and talc in this weight ratio, an effect is obtained that adhesion between seeds during coating and adhesion of titanium oxide to the processing tank is suppressed. In addition, the seed can be colored without being affected by the seed coat color. In addition, peeling of the coating layer from the seeds hardly occurs, and there is no adverse effect on germination performance.

Furthermore, it is also important that titanium oxide in the seed coating material containing water is contained in an amount of 10% by mass to 40% by mass, and the weight ratio of titanium oxide: talc is 3: 1 to 0.5: 1. By setting the content of titanium oxide within this range and containing titanium oxide and talc in this weight ratio, the titanium oxide does not settle during storage and forms a hard precipitated layer, even if a precipitated layer is formed. Can be easily resuspended.

The titanium oxide used in the present invention preferably has an average particle size of 0.1 μm or more and 1 μm or less. A more preferable average particle diameter is 0.1 μm or more and 0.6 μm or less. In addition, the titanium oxide used in the present invention is preferably a rutile type having low activity as a catalyst and excellent thermal stability.

The talc used in the present invention preferably has an average particle size of 0.1 μm or more and 20 μm or less. A more preferable average particle diameter is 0.1 μm or more and 10 μm or less.

In the present invention, it is also important that titanium oxide and talc are contained in the above-mentioned weight ratio and that PVA is further contained. Thereby, the dispersibility of a titanium oxide improves and adhesion of the seeds during a coating process and adhesion of the titanium oxide to a processing tank are suppressed. It is also important that the weight ratio of PVA: EVA is 3: 1 to 0.5: 1. Thereby, adhesion of titanium oxide and talc to the seed surface is improved, peeling does not occur, and germination performance is not adversely affected. A more preferred PVA: EVA weight ratio is 2: 1 to 1: 1.

The PVA used in the present invention is preferably a polymer having a weight average molecular weight in the range of 300 to 2,000, and more preferably a polymer having a weight average molecular weight of 400 to 1,000. PVA is preferably completely (98% to 100%), moderately (90 to 98%), partially (70 to 90%) hydrolyzed, and partially (70 to 90%) hydrolyzed. Those decomposed are more preferred.

The EVA used in the present invention preferably has a weight ratio of ethylene to vinyl acetate of 9: 1 to 6: 4, more preferably a weight ratio of 8: 2 to 7: 3. The EVA is preferably in the form of an emulsion. The solid concentration in the emulsion is preferably 30 to 60%, and the particle size is preferably 0.1 μm to 1 μm.

As the polymer component, other polymers may be added in addition to PVA and EVA. Examples of the polymer that can be added include conventionally known polymers. For example, polyvinyl pyrrolidone (PVP), carboxymethyl cellulose (CMC), methyl cellulose, cellulose acetate, starch, gelatin and the like can be mentioned.

In the present invention, other powder components may be added as a powder component in addition to titanium oxide and talc. Conventionally known powder components can be used as the powder component that can be added. For example, vegetable powder (wheat flour, wood flour, etc.), mineral powder, (kaolin, bentonite, sepiolite, acid clay, clays, diatomaceous earth, silica such as mica powder, etc.), calcium carbonate, alumina, activated carbon Etc.

In the coating material of the present invention, coloring agents, surfactants, antifoaming agents, preservatives, fungicides, biocides, insecticides, nematicides, herbicides, plant growth regulators and the like are appropriately blended. Can also be used.

Examples of the colorant include anthraquinone, triphenylmethane, phthalocyanine and derivatives thereof, and diazonium salts. These can be used alone or in combination of two or more. The colorant may be a pigment or a dye.

As the surfactant, for example, soaps, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene nonyl phenyl ethers, Polyoxyethylene polyoxypropylene ethers, polyoxyethylene distyrenated phenyl ether, polyoxyethylene alkyl esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, higher fatty acid alkanolamides, alkylmaleic acid copolymers, many Examples of cationic surfactants include alkylamine salts and quaternary ammonium salts. Examples of anionic surfactants include: Naphthalenesulfonic acid polycondensate metal salt, formalin condensate of naphthalenesulfonate, alkylnaphthalenesulfonate, ligninsulfonate metal salt, alkylallylsulfonate, alkylallylsulfonate sulfate, etc., polystyrene sulfonate Examples include sodium salts, polycarboxylic acid metal salts, polyoxyethylene histidyl phenyl ether sulfate ammonium, higher alcohol sulfonates, higher alcohol ether sulfonates, dialkyl sulfosuccinates or higher fatty acid alkali metal salts. One or more types can be mixed and used as appropriate.

Examples of antifoaming agents include silicon-based antifoaming agents, magnesium stearate, long chain alcohols, fatty acids and salts thereof, and these can be used as appropriate by mixing one or more of them in an appropriate ratio.

Examples of the preservative include 1,2-benzisothiazolin-3-one, butylparaben, potassium sorbate and the like, and these can be used as appropriate by mixing one or more of them in an appropriate ratio.

Examples of the fungicide include captan, thiuram, metalaxyl, iprodione, flutolanil, mepronil, mefonoxam, and the like, which can be used as appropriate by mixing one or more of them in an appropriate ratio.

Examples of biocides include streptomycin, penicillin, tetracycline, ampicillin, oxophosphoric acid, and the like, which can be used as appropriate by mixing one or more of them in an appropriate ratio.

Examples of insecticides include pyrethroids, organic phosphates, calamoyl oximes, pyrazoles, amidines, halogenated hydrocarbons, neonicotinoids, and carbamates, and these should be used as appropriate by mixing one or more of them in an appropriate ratio. Can do.

Examples of nematicides include abamectin, thiodicarb, etc., and these can be used as appropriate by mixing one or more of them in an appropriate ratio.

(How to use the coating material)
The coating material of the present invention may be used as it is, or may be appropriately diluted depending on the type of seed and the processing machine.

(Seed coating)
As a method of coating seeds with the coating material of the present invention, a conventionally known processing method and processing apparatus can be used. As the processing method, mixing with seeds, mechanical application, spraying, dipping and the like can be used. As the apparatus used for coating, for example, a fluidized bed drying type seed processing apparatus or a roto-stat type seed processing apparatus can be preferably used.

Specifically, seeds are put in a coating apparatus, and the coating material or an aqueous solution thereof is sprayed while stirring (rolling) in the coating apparatus. Then, after coating the seed surface with a coating material, the coated seed is dried if necessary. The drying temperature is usually 50 ° C. or lower, preferably 25 ° C. or higher and 50 ° C. or lower.

(Coated seed)
The seeds that can be coated with the coating material of the present invention are not particularly limited, and examples include vegetable seeds, flower seeds, pasture seeds, wild grass seeds, cereal seeds, and craft crop seeds. It is done.

Examples of vegetable seeds include cucumber, melon, pumpkin and other cucurbitaceae vegetable seeds; eggplant, tomato and other solanaceous vegetable seeds; peas and kidney beans and other leguminous vegetable seeds; Seeds; Brassicaceae vegetable seeds such as Brassica genus such as turnip, Chinese cabbage, cabbage, broccoli, and radish; Vegetable seeds of Caceae family such as carrot, celery; Vegetable seeds of Lamiaceae; vegetable seeds of red crustaceae such as spinach.

As the flower seeds, for example, flower seeds of Brassicaceae such as ha button, stock, alyssum, etc., flower seeds of the asteraceae such as Lobelia, for example, flower seeds of the asteraceae such as aster, zinnia, sunflower, etc. Flower seeds such as primroses such as snapdragons, flower seeds such as primulas such as primula, flower seeds such as rhododendrons such as begonia, and flower seeds such as Labiatae such as salvia, such as violets such as pansy and viola For example, plant seeds of solanaceae such as petunia, and plant seeds of gentian family such as eustoma.

Examples of grass seeds include grass seeds such as timothy, Italian ryegrass, Bermuda grass, buckwheat, Sudan grass, crane grass, fescue, orchard grass.

Examples of wild grass seeds include leguminous wild grass seeds such as alfalfa and clover, for example, grass grass seeds such as grass bark.

Examples of cereal seeds include rice, barley, wheat, soybean, millet, millet, and millet.

Examples of craft crop seeds include red crustacean seeds such as sugar beet, solanaceous seeds such as tobacco, cruciferous seeds such as rapeseed, and gramineous seeds such as rush.

(Pre-processing and post-processing)
The seed to be coated may be coated and granulated in advance by a conventionally known method before being coated with the coating material of the present invention. Moreover, the process for disinfection, germination improvement, etc. may be given. Alternatively, after coating with the coating material of the present invention, treatment for coating granulation, sterilization, germination improvement, and the like may be performed.

Example 1
(Preparation of coating material)
25 parts by weight of polyvinyl alcohol was suspended in 75 parts by weight of water, and dissolved by heating to 95 ° C. to obtain a polyvinyl alcohol aqueous solution having a concentration of 25%.
Further, 11.4 parts by weight of water was placed in a 1 L beaker, and 0.3 parts by weight of a nonionic surfactant and 0.3 parts by weight of an anionic surfactant were added while stirring. Next, 15 parts by weight of talc (average particle diameter 10 μm) and 30 parts by weight of titanium oxide (rutile type, average particle diameter 0.3 μm) were further added and stirred for 10 minutes. Next, 20 parts by weight of the prepared 25% polyvinyl alcohol aqueous solution, 5.0 parts by weight of 50% emulsion of ethylene vinyl acetate copolymer, and 18 parts by weight of an aqueous dispersion (monoazo red) as a pigment were added. Added and stirred for about 30 minutes. All mixing was performed at room temperature. The precipitation property and redispersibility of the obtained coating material were evaluated by the methods described below. The evaluation results are shown in Table 2.

(Production of coated seeds)
10 mL of water was added to 15 mL of the obtained coating material to prepare a diluted solution. Then, 200 g of cabbage seed was coated with 8 mL of the diluted solution using a roto-stat type seed treatment apparatus.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 2. In addition, the adhesion state of the coating material to the inner wall or the like of the processing apparatus was evaluated by the method described later. The evaluation results are shown in Table 2.
Moreover, when the germination rate of the obtained coated seeds was measured by the following method, it was the same as that of uncoated seeds.
(Germination test)
Prepare a petri dish with a diameter of 9 cm on which two filter papers are laid, drop 4.5 ml of water onto it, place 50 seeds of each seed, store at 20 ° C under light conditions of about 2000 lux, and store 7 The germination rate (%) on the day was measured.

Example 2
A coating material was prepared in the same manner as in Example 1 except that 8.4 parts by weight of water, 24 parts by weight of an aqueous polyvinyl alcohol solution having a concentration of 25%, and 4.0 parts by weight of a 50% emulsion of ethylene-vinyl acetate copolymer were used. The seeds were produced and coated with the produced coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 3
A coating material was prepared in the same manner as in Example 1 except that 12.4 parts by weight of water, 16 parts by weight of an aqueous polyvinyl alcohol solution having a concentration of 25%, and 8.0 parts by weight of a 50% emulsion of an ethylene vinyl acetate copolymer were used. The seeds were produced and coated with the produced coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 4
A coating material was prepared in the same manner as in Example 1 except that 14.4 parts by weight of water, 12 parts by weight of an aqueous polyvinyl alcohol solution having a concentration of 25%, and 10 parts by weight of a 50% emulsion of ethylene-vinyl acetate copolymer were used. Then, the seed was coated with the prepared coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 5
Example 1 except that 11.4 parts by weight of water, 11.25 parts by weight of talc (average particle size 10 μm) and 33.75 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Then, a coating material was produced, and the seed was coated with the produced coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 6
Example 1 except that 11.4 parts by weight of water, 22.5 parts by weight of talc (average particle size 10 μm) and 22.5 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Then, a coating material was produced, and the seed was coated with the produced coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 7
A coating material was prepared in the same manner as in Example 1 except that 6.4 parts by weight of water and 35 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Covered. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 8
A coating material was prepared in the same manner as in Example 1 except that 21.4 parts by weight of water and 20 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Covered. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 9
A coating material was prepared in the same manner as in Example 1 except that 31.4 parts by weight of water and 10 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Covered. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Comparative Example 1
A coating material was prepared in the same manner as in Example 1 except that 9.4 parts by weight of water and 3.0 parts by weight of a 50% emulsion of ethylene vinyl acetate copolymer were used, and the seeds were coated with the prepared coating material. did. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Comparative Example 2
(Preparation of coating material)
Coating material in the same manner as in Example 1 except that 11.4 parts by weight of water, 10 parts by weight of talc (average particle size 10 μm), and 35 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. And seeds were coated with the prepared coating material. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Comparative Example 3
A coating material was prepared in the same manner as in Example 1 except that 36.4 parts by weight of water and 5 parts by weight of titanium oxide (rutile type, average particle size 0.3 μm) were used. Covered. The sedimentation property and redispersibility of the coating material, the appearance of the coated seed and the peelability of the coating layer, and the adhesion state of the coating material in the treatment apparatus were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 10
A coating material was obtained in the same manner as in Example 1. 20 mL of water was added to 20 mL of the obtained coating material to prepare a diluted solution. Using a roto-stat type seed treatment apparatus, 200 g of carrot seeds were coated with 24 mL of a diluent.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 3.
Moreover, when the germination rate of the obtained coated seeds was measured by the following method, it was the same as that of uncoated seeds.
(Germination test)
Prepare a petri dish with a diameter of 9 cm with two filter papers, drop 4.5 mL of water on it, place 50 seeds of each seed, store at 20 ° C. under light conditions of about 900 lux, and store 10 The germination rate (%) on the day was measured.

Example 11
In the same manner as in Example 11, 200 g of spinach seeds were coated with 16 mL of diluent.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 3.
Moreover, when the germination rate of the obtained coated seeds was measured by the following method, it was the same as that of uncoated seeds.
(Germination test)
The seeds were sandwiched in 5 × 10 rows on a filter paper folded in a bellows shape with a length of 60 cm and a width of 2.5 cm, and after dropping 15 mL of water there, under a light condition of about 2000 lux at a temperature of 25 ° C. The germination rate (%) on the seventh day after storage was measured.

Example 12
In the same manner as in Example 11, 200 g of burdock seeds were coated with 16 mL of diluent.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 3.
Moreover, when the germination rate of the obtained coated seed was measured by the same method as in Example 12, it was the same as that of the uncoated seed.

Example 13
In the same manner as in Example 11, 200 g of watermelon seed was coated with 16 mL of the diluent.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 3.
Moreover, when the germination rate of the obtained coated seeds was measured by the following method, it was the same as that of uncoated seeds.
(Germination test)
The seeds were sandwiched in 4 × 10 rows on a filter paper folded in a bellows shape with a length of 60 cm and a width of 2.5 cm, and after dropping 15 mL of water there, under a light condition of about 900 lux at 30 ° C. The germination rate (%) on the seventh day after storage was measured.

Example 14
In the same manner as in Example 11, 200 g of sweet corn seed was coated with 16 mL of the diluent.
The appearance (colored state) of the obtained coated seed and the peelability of the coating layer from the seed were evaluated by the methods described below. The evaluation results are shown in Table 3.
Moreover, when the germination rate of the obtained coated seeds was measured by the following method, it was the same as that of uncoated seeds.
(Germination test)
The seeds were sandwiched in a filter paper folded in a bellows shape with a length of 60 cm and a width of 2.5 cm, and after dropping 15 mL of water there, under a light condition of about 2000 lux at a temperature of 25 ° C. The germination rate (%) on the seventh day after storage was measured.

(Processability)
The state of adhesion of the coating material to the inner wall or the like of the processing apparatus was evaluated visually according to the following criteria.
“O”: No adhesion.
“△”: Slightly adhered.
“×”: Large amount of adhesion.

(Presence of precipitation layer)
10 mL of the covering material was put in a 15 mL test tube, and after standing for 14 days, it was visually evaluated according to the following criteria.
“O”: No precipitation separation.
“△”: There is a precipitate layer although it is unclear.
“×”: Precipitation layer is present.

(Redispersibility)
About the coating material in which the precipitation layer was formed in the evaluation test of the presence or absence of the precipitation layer, the test tube was stirred up and down 5 times, and the redispersibility was visually evaluated according to the following criteria.
“◯”: Can be easily redispersed.
“Δ”: Redispersed substantially by stirring.
“×”: Cannot be redispersed even with stirring.

(appearance)
The appearance (colored state) of the coated seed was visually evaluated according to the following criteria.
“◯”: Good coloring.
“△”: Slightly dull in coloring.
“×”: Coloring is insufficient.

(Removal of coating layer)
After 5 g of the coated seeds were sealed in a 50 mL polystyrene bar and shaken for 30 minutes, the peeled state was visually evaluated according to the following criteria.
“◯”: No peeling at all.
“△”: Slight peeling.
"X": There is a large amount of peeling.

The coating materials of Examples 2 to 4 were obtained by changing the weight ratio of PVA and EVA in the range of 3: 1 to 0.6: 1 on the basis of the coating material of Example 1, and Examples 5 to 9 The coating material in which the weight ratio of titanium oxide and talc was changed in the range of 3: 1 to 0.66: 1 on the basis of the coating material of Example 1, all the coating materials being workable, There were no problems in actual use in each evaluation item of presence / absence of a precipitate layer, redispersibility, appearance, and peeling.

On the other hand, with the coating material of Comparative Example 1 in which the weight ratio of PVA to EVA was 4: 1 and exceeded the specified range of the present invention, workability was poor and a large amount of coating material adhered to the inner wall of the processing apparatus. It was observed. Further, a large amount of peeling from the seed of the coating layer was observed.

Further, in the coating material of Comparative Example 2 in which the weight ratio of titanium oxide and talc was 3.5: 1 which exceeded the specified range of the present invention, a large amount of peeling from the seed of the coating layer was observed. On the other hand, in the coating material of Comparative Example 3 in which the weight ratio of titanium oxide to talc is 0.33: 1 which is smaller than the specified range of the present invention and the content of titanium oxide is as small as 5% by mass, seed coloring Was insufficient. In addition, a precipitate layer was formed and did not redisperse even when stirred.

Examples 10 to 14 were obtained by coating various seeds of carrots, spinach, burdock, watermelon, and sweet corn having different seed shapes using the coating material prepared in Example 1. As in the case of cabbage seeds of Example 1, there were no problems at all for the evaluation items of processability, presence or absence of a precipitate layer, redispersibility, and appearance. In addition, peeling of the coating layer from the seeds was at a problem level in practical use.

According to the seed coating material of the present invention, there are few precipitates of titanium oxide during storage and excellent redispersibility. Moreover, there is little adhesion between seeds and the processing tank during the coating process, and the color of the coated seed is good without being affected by the seed coat color. Peeling from the seed of the coating layer does not occur, and the germination performance is not adversely affected.

Claims

Contains titanium oxide, talc, polyvinyl alcohol, and ethylene / vinyl acetate copolymer,
The content of titanium oxide in the seed coating material containing water is 10% by mass or more and 40% by mass or less,
The weight ratio of titanium oxide: talc is 3: 1 to 0.5: 1,
A water-suspendable seed coating material having a weight ratio of polyvinyl alcohol: ethylene / vinyl acetate copolymer of 3: 1 to 0.5: 1.
The seed coating material according to claim 1, wherein the titanium oxide has a mass average particle diameter of 0.1 μm to 1 μm.
The seed coating material according to claim 1 or 2, wherein the talc has a mass average particle diameter of from 0.1 µm to 20 µm.
A seed having a surface coated with the seed coating material according to any one of claims 1 to 3.