WO2022131217A1 - Method for manufacturing coated granular fertilizer, and coated granular fertilizer - Google Patents

Abstract

Provided are a method for manufacturing a coated granular fertilizer that has high homogeneity in a resin coating, and this coated granular fertilizer. The method for manufacturing a coated granular fertilizer that is composed of a granular fertilizer and a urethane resin coating film coating the granular fertilizer, said method comprising a step for adding a polyisocyanate component, a polyol component and diazabicyclononene to the granular fertilizer in a rotated state, and a step for performing polyaddition of the polyisocyanate component and the polyol component while maintaining the granular fertilizer in the rotated state to thereby form the urethane resin coating film on the surface of the granular fertilizer; and the coated granular fertilizer that has high homogeneity in the resin coating.

Description

Manufacturing method of coated granular fertilizer and coated granular fertilizer

This patent application claims priority and interests under the Paris Convention under Japanese Patent Application No. 2020-206637 (filed December 14, 2020) and is described in the above application by reference here. The entire contents of the above shall be incorporated herein by reference.

The present invention relates to a method for producing a coated granular fertilizer and a coated granular fertilizer.

Conventionally, due to the aging of agricultural workers, the decrease in the number of workers, and the increase in the number of part-time farmers, various fertilizer effects that have the function of elution of fertilizer components at a predetermined time according to the growth of plants as a more labor-saving fertilizer. Adjustable coated fertilizers have been proposed. In the olden days, it has been known that granular fertilizer is coated with resin, wax, sulfur, etc. and encapsulated to control the elution rate of fertilizer components. Further, as a method for producing a resin-coated granular fertilizer, a method of adding uncured urethane containing a catalyst to the granular fertilizer in a rolling state is known in order to coat the surface of the granular fertilizer with urethane resin. (See, for example, Patent Document 1). However, in these methods, the granular fertilizers stick to each other or adhere to the rolling apparatus of the granular fertilizers, so that the homogeneity of the coating of the resin-coated granular fertilizers and the efficiency of production are not always satisfactory. It wasn't. As a means for solving such a problem, in a method for producing a coated granular fertilizer, by adding liquid paraffin or the like to the surface of granular urea before coating the resin, the particles are aggregated between the particles and the particles are transferred to the rolling element. A method for suppressing the occurrence of adhesion and the like has been proposed (see Patent Document 2). However, even in this method, there is still room for improvement in suppressing the occurrence of aggregation of particles and adhesion of particles to the rolling element.

Japanese Unexamined Patent Publication No. 9-202683 Japanese Unexamined Patent Publication No. 2011-16685

An object of the present invention is to provide a method for producing a coated granular fertilizer having excellent homogeneity of resin coating.

The present inventor has studied to find an excellent method for producing a resin-coated granular fertilizer. As a result, in the method for producing a coated granular fertilizer, by using diazabicyclononen as a catalyst in forming a film, particles are used. We have found that a coated granular fertilizer can be obtained in which the aggregation of the fertilizer and the adhesion of particles to the rolling element are suppressed, and the present invention has been completed.
That is, the present invention is as follows.
[1] A method for producing a coated granular fertilizer comprising a granular fertilizer and a urethane resin coating for coating the granular fertilizer.
A step of adding a polyisocyanate component, a polyol component, and diazabicyclononen to the granular fertilizer in a rolling state; and a weighting of the polyisocyanate component and the polyol component while maintaining the rolling state of the granular fertilizer. A method for producing a coated granular fertilizer, which comprises a step of forming the urethane resin film on the surface of the granular fertilizer by adding the mixture.
[2] The production method according to [1], wherein the amount of diazabicyclononen added is 0.01 to 2% by weight based on the total amount of the polyisocyanate component and the polyol component.
[3] The production method according to [1] or [2], which comprises the following steps:
(A) A step of mixing a polyisocyanate component, a polyol component, and diazabicyclononen to obtain a mixture.
(B) The step of adding the mixture obtained in the above step (a) to the granular fertilizer in the rolling state, and (c) maintaining the rolling state of the granular fertilizer, and adding the polyisocyanate component and the polyol component repeatedly. The process of forming a resin film on the surface of granular fertilizer.
[4] The production method according to [1] or [2], which comprises the following steps:
(A) A step of mixing a polyisocyanate component and a polyol component to obtain a mixture.
(B) A step of separately adding the mixture obtained in the above step (a) and diazabicyclononen to the granular fertilizer in a rolling state, and (c) maintaining the rolling state of the granular fertilizer and polyisocyanate. A process of forming a resin film on the surface of granular fertilizer by adding components and polyol components in layers.
[5] The production method according to [1] or [2], which comprises the following steps:
(A) A step of mixing a polyol component and diazabicyclononen to obtain a mixture.
(B) A step of separately adding the polyisocyanate component and the mixture obtained in the above step (a) to the granular fertilizer in the rolling state, and (c) maintaining the rolling state of the granular fertilizer and the polyisocyanate component. And a polyol component are heavily added to form a resin coating on the surface of granular fertilizer.
[6] The production method according to [1] or [2], which comprises the following steps:
(A) A step of separately adding a polyisocyanate component, a polyol component, and diazabicyclononen to a granular fertilizer in a rolling state, and (b) maintaining the rolling state of the granular fertilizer, a polyisocyanate component and a polyol. A process of forming a resin film on the surface of granular fertilizer by adding components in layers.
[7] The production method according to any one of [1] to [6], wherein the polyisocyanate component contains an aromatic polyisocyanate.
[8] The production method according to any one of [1] to [7], wherein the polyol component contains castor oil-modified diol.
[9] The polyol component contains two or more compounds selected from the group consisting of castor oil-modified diols, alkylene diols having 2 to 8 carbon atoms, and compounds having 3 or more hydroxyl groups [1] to [7]. The manufacturing method according to any one of the above.
[10] The production method according to any one of [1] to [8], wherein the polyol component contains a castor oil-modified diol, an alkylene diol having 2 to 8 carbon atoms, and a compound having 3 or more hydroxyl groups. ..
[11] A granular fertilizer and a resin film for covering the granular fertilizer are provided.
A coated granular fertilizer (hereinafter referred to as "coated granular fertilizer of the present invention") in which the resin film contains urethane resin and diazabicyclononen, which are heavy adducts of a polyisocyanate component and a polyol component.

According to the present invention, the generation of agglomeration between particles during resin coating on granular fertilizer and adhesion of particles to a rolling element is suppressed, and a resin coating can be uniformly formed on each particle. It is possible to provide a coated granular fertilizer in which variation in the elution pattern is suppressed.

In the method for producing a coated granular fertilizer of the present invention (hereinafter referred to as "the production method of the present invention"), a polyisocyanate component, a polyol component, and diazabicyclononen are added to the surface of a granular fertilizer in a rolling state. A step; and a step of forming a urethane resin film on the surface of the granular fertilizer by repeatedly adding a polyisocyanate component and a polyol component while maintaining the rolling state of the granular fertilizer.

The granular fertilizer used in the present invention may be a granular material containing a fertilizer component. Further, the granular fertilizer used in the present invention may be, for example, a granular material in which the fertilizer component is granulated by itself, or a granular material containing a fertilizer component and a carrier holding the fertilizer component.

In the present invention, the fertilizer component is not particularly limited and can be appropriately selected depending on the use and purpose of use of the coated granular fertilizer. Examples of fertilizer components include urea, ammonium nitrate, ammonium nitrate, ammonium chloride, ammonium sulfate, ammonium phosphate, sodium nitrate, calcium nitrate, potassium nitrate, lime nitrogen, formaldehyde processed urea (UF), and acetaldehyde processed urea (CDU). Nitrogen fertilizer components such as isobutylaldehyde-processed urea (IBDU) and guanylurea (GU); lime perphosphate, lime perphosphate, fused phosphorus, phosphorus rot, calcined phosphorus, heavy roasted phosphorus, bitter phosphorus. Phosphoric acid fertilizer components such as acid, ammonium polyphosphate, potassium metaphosphate, calcium metaphosphate, bittersweet phosphoric acid, phosphoric acid sulphate, potassium phosphonitrous, and salt phosphorus; and potassium chloride, potassium sulfate, potassium sulfate, potassium sulfate. Examples thereof include potassium fertilizer components such as bitter soil, potassium bicarbonate, and potassium phosphate. As these fertilizer components, one type may be used alone, or two or more types of fertilizer components may be used in combination.

In the present invention, the carrier that retains the fertilizer component can be appropriately selected according to the type of fertilizer component, the use of the coated granular fertilizer, the purpose of use, and the like. Carriers include, for example, kaolin minerals such as kaolinite, mineral substances such as montmorillonite, smectite, talc, wax stone, silica, zeolite, acidic white clay; vegetable substances such as cellulose, rice husks, starch, soybean flour; lactose, sugar, dextrin, etc. It may contain water-soluble substances such as salt and sodium tripolyphosphate. The carrier may contain one of these components alone, or may contain a plurality of of these components. Further, the granular fertilizer may contain one kind of carrier, or may contain two or more kinds of carriers.

In the present invention, the granular fertilizer may further contain a fertilizer component and other components other than the carrier.

The granular fertilizer used in the present invention is produced, for example, by a method of granulating a fertilizer component alone, a method of mixing a fertilizer component and a carrier (with other components if necessary), and the like. be able to. The granulation method may be a normal granulation method for granules. Examples of such a granulation method include an extrusion granulation method, a fluidized bed type granulation method, a rolling granulation method, a compression granulation method, a bread granulation method, a coated granulation method and an adsorption granulation method.

The particle size of the granular fertilizer used in the present invention is not particularly limited, and can be appropriately selected depending on the type of fertilizer component and carrier, the use and purpose of the coated granular fertilizer, and the like. For example, the average particle size of the granular fertilizer may be 0.1 to 15 mm, 1 to 10 mm, or 1 to 5 mm. In the present embodiment, for example, granular fertilizer having an arbitrary particle size can be obtained by obtaining granular fertilizer by the above-mentioned production method and then classifying using a sieve having an appropriate opening diameter. In the present specification, the average particle size of the granular fertilizer is defined by an arithmetic mean value (also referred to as an arithmetic mean value) of the diameter corresponding to the projected area circle, and is defined by a microscopy method (for example, an electron microscope or an optical microscope). Measured at. The measuring method may vary depending on the size of the particle size of the granular fertilizer to be measured and the like.

The shape of the granular fertilizer used in the present invention is not particularly limited, and can be appropriately selected depending on the type of fertilizer component and carrier, the use and purpose of the resin-coated granular fertilizer, and the like. The shape of the granular fertilizer may be, for example, a spherical shape, a polyhedral shape, a columnar shape, an irregular shape, or the like, and a shape close to a spherical shape is preferable.

The diazabicyclononene used in the present invention is also called 1,5-diazabicyclo (4.3.0) nonene-5 or DBN, and is represented by the structural formula (I) below.

Examples of the diazabicyclononen used in the present invention include DBN (manufactured by San-Apro Co., Ltd.). In the present production method, diazabicyclononen may be a catalytic amount, preferably 0.01 to 2% by weight, more preferably 0.01 to 1% by weight, based on the total amount of the polyisocyanate component and the polyol component. Used at a rate of%. More preferably, it is used in a proportion of 0.02 to 0.07% by weight.

In the present invention, the urethane resin means a resin that is three-dimensionally crosslinked by reacting a polyisocyanate component and a polyol component. In the present invention, the mixture of the polyisocyanate component and the polyol component (sometimes referred to as "uncured urethane") is such that the polyisocyanate component and the polyol component do not react at all or are not three-dimensionally crosslinked. It means a part that has been partially reacted in advance. The form of the mixture may be any of a solvent-free type, a solution type, an aqueous emulsion type and the like, but a solvent-free type and a liquid type in the step of adding to the granular fertilizer can be preferably used.

In the present invention, polyisocyanate means a compound having two or more isocyanate groups. Examples of such polyisocyanates include aromatic polyisocyanates, aliphatic polyisocyanates and alicyclic polyisocyanates, and derivatives thereof.
In the present invention, the polyisocyanate preferably contains an aromatic polyisocyanate from the viewpoint of sustained release performance (also referred to as slow release).

In the present invention, the aromatic polyisocyanate means a compound having an aromatic ring and two or more isocyanate groups. The aromatic polyisocyanate may be a compound having one aromatic ring in the molecule, or may be a compound having a plurality of aromatic rings. The isocyanate group of the aromatic polyisocyanate is preferably directly bonded to the aromatic ring. The aromatic ring may be a benzene ring.

Specific examples of aromatic polyisocyanates include 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), trizine diisocyanate (TODI), naphthalene-1,5-diisocyanate (NDI). ), Tetramethylene xylylene diisocyanate (TMXDI), and polymethylene polyphenyl polyisocyanate (polymeric MDI), and derivatives thereof (for example, modified products such as isocyanurate form, biuret form, uretdione form, etc.). As the aromatic polyisocyanate, one of these may be used alone, or two or more thereof may be used in combination.

The aromatic polyisocyanate may be an aromatic polyisocyanate having two or more benzene rings having an isocyanate group from the viewpoint of sustained release performance. In such an aromatic polyisocyanate, the number of isocyanate groups directly bonded to each benzene ring may be one, or may be two or more. Examples of such aromatic polyisocyanates include MDI, TDI, TODI, and oligomers derived from them (for example, polypeptide MDI and the like).

In the present invention, the aliphatic polyisocyanate means a compound having a fatty chain and two or more isocyanate groups. Specific examples of such an aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), dimerate diisocyanate (DDI), and norbornene diisocyanate (NBDI).

In the present invention, the alicyclic polyisocyanate means a saturated or unsaturated carbocycle having no aromaticity and a compound having two or more isocyanate groups. Examples of such alicyclic polyisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), hydrogenated XDI and the like.

In the present invention, lysine triisocyanate, lysine diisocyanate and the like can also be used as polyisocyanate. Derivatives of polyisocyanate include, for example, modified products such as isocyanurate form, biuret form, and uretdione form.

When the polyisocyanate component contains an aromatic polyisocyanate, the ratio of the aromatic polyisocyanate to the polyisocyanate component may be 30% by weight or more, and may be 50% by weight or more from the viewpoint of sustained release performance. , Or 100% by weight.

In the present invention, the polyol component means a compound having 2 or more hydroxyl groups per molecule. Examples of such polyol components include alkylene diols having 2 to 8 carbon atoms, polyether polyols, polyester polyols, vegetable oils having two or more hydroxyl groups, and modified products thereof.
In the present invention, the polyether polyol means a compound having two or more ether bonds and two or more hydroxyl groups in the molecule. The polyether polyol can be obtained, for example, by using a polyhydric alcohol, an amino alcohol, or an amine as an initiator and adding ethylene oxide or propylene oxide in a double manner. Specific examples of the polyether polyol include polytetramethylene ether glucol obtained by polymerizing tetrahydrofuran.
In the present invention, the polyester polyol means a compound having two or more ester bonds and two or more hydroxyl groups in the molecule. The polyester polyol can be obtained, for example, by reacting a polyhydric alcohol with a polyether polyol and a carboxylic acid-containing compound. It can also be obtained, for example, by ring-opening polymerization of a cyclic ester compound using a polyhydric alcohol as an initiator.

Examples of vegetable oils having two or more hydroxyl groups include castor oil, soybean oil, and cottonseed oil. Examples of the modified product of the vegetable oil having 2 or more hydroxyl groups include castor oil-modified diol and castor oil-modified polyol having 3 or more hydroxyl groups.
In the present invention, it is preferable that the polyol component contains castor oil-modified diol from the viewpoint of sustained release performance. Further, from the viewpoint of sustained release performance, the polyol component is two or more (that is, two or three) selected from the group consisting of castor oil-modified diols, alkylene diols having 2 to 8 carbon atoms, and compounds having 3 or more hydroxyl groups. It is more preferable to contain the compound of (1).

In the present invention, the castor oil-modified diol means a compound that can be derived from castor oil by a chemical reaction and has two hydroxyl groups. The castor oil-modified diol may be derived from castor oil, or may be a compound that can be derived from castor oil and may be a compound produced from a raw material other than castor oil. Castor oil is a fatty oil containing a glyceride of ricinoleic acid as a main component, and the castor oil-modified diol may be, for example, ricinoleic acid-modified diol.

In the present invention, a commercially available product can be used as the castor oil-modified diol. Examples of such commercially available products include URIC H-62 (hydroxyl value: 245 to 275, manufactured by Ito Oil Co., Ltd.), URIC Y-202 (hydroxyl value: 110 to 120, manufactured by Ito Oil Co., Ltd.), and URIC Y-403. (Filament value: 150-170, manufactured by Ito Oil Co., Ltd.), URIC Y-332 (hydroxyl value: 113-133, manufactured by Ito Oil Co., Ltd.), URIC AC-005 (hydroxyl value: 194-214, manufactured by Ito Oil Co., Ltd.) , URIC AC-006 (hydroxyl value: 168-187, manufactured by Ito Oil Co., Ltd.), URIC PH-5001 (hydroxyl value: 45, manufactured by Ito Oil Co., Ltd.), URIC PH-5002 (hydroxyl value: 43, manufactured by Ito). (Manufactured by Oil Refinery Co., Ltd.), HS 2G-120 (hydroxyl value: 122, manufactured by Toyokuni Oil Co., Ltd.), HS 2G-160R (hydroxyl value: 121, manufactured by Toyokuni Oil Co., Ltd.), HS 2G-270B (hydroxyl value: 261), (Toyogoku Oil Co., Ltd.), HS 2B-5500 (hydroxyl value: 178, manufactured by Toyokuni Oil Co., Ltd.), and HS KA-001 (hydroxyl value: 224, manufactured by Toyokuni Oil Co., Ltd.), but are not limited thereto. ..
Here, the "hydroxyl value" means the number of mg of potassium hydroxide corresponding to the hydroxyl group in 1 g of the sample, as described in the Japanese Industrial Standards (JIS) Polyurethane Polyether Test Method (K 1557). Actually, it is a value calculated by esterifying a test sample with a pyridine solution of phthalic anhydride and titrating the excess reagent with a sodium hydroxide solution.

When the polyol component contains castor oil-modified diol, the content of castor oil-modified diol in the polyol component may be 6% by weight or more, and 8% by weight or more, based on the total amount of the polyol component, from the viewpoint of sustained release performance. It may be 10% by weight or more, 30% by weight or more, 50% by weight or more, or 65% by weight or more. Further, the content of the castor oil-modified diol may be 93% by weight or less, 90% by weight or less, or 85% by weight or less based on the total amount of the polyol component from the viewpoint of sustained release performance. It's okay.

In the present invention, from the viewpoint of sustained release performance, an alkylene diol having 2 to 8 carbon atoms (hereinafter, also simply referred to as “alkylene diol”) may be contained as a polyol component. The carbon number of the alkylenediol is preferably 3 or more, more preferably 4 or more, preferably 7 or less, or more preferably 6 or less.

The alkylene diol may be linear or branched chain. Examples of the linear alkylene diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,8-octanediol. Can be mentioned. Examples of the branched alkylene diol include 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, and 2,3-dimethyl-1,4-butanediol. ..

When the polyol component contains an alkylene diol, the content of the alkylene diol in the polyol component may be 4% by weight or more, and 6% by weight or more, based on the total amount of the polyol component, from the viewpoint of sustained release performance. It may be 8% by weight or more, or 10% by weight or more. Further, the content of the alkylene diol may be 25% by weight or less, 21% by weight or less, or 20% by weight or less based on the total amount of the polyol component from the viewpoint of sustained release performance. , 18% by weight or less, or 15% by weight or less.

In the present invention, a compound having 3 or more hydroxyl groups may be contained as a polyol component from the viewpoint of sustained release performance. In the present invention, the compound having 3 or more hydroxyl groups means a compound having 3 or more hydroxyl groups per molecule. A compound having 3 or more hydroxyl groups may have 3 to 8 hydroxyl groups or 3 to 6 hydroxyl groups per molecule.

Examples of the compound having 3 or more hydroxyl groups include a polyether polyol having 3 or more hydroxyl groups, a castor oil, a castor oil modified polyol having 3 or more hydroxyl groups (for example, a castor oil modified triol), and a poly (meth) having 3 or more hydroxyl groups. Examples thereof include acrylic acid polyols, condensed polyester polyols having 3 or more hydroxyl groups, and lactone-based polyester polyols having 3 or more hydroxyl groups. As the compound having 3 or more hydroxyl groups, one type may be used alone, or two or more types may be used in combination. As the compound having 3 or more hydroxyl groups, a compound contained in a commercially available product may be used. As the compound having 3 or more hydroxyl groups, a castor oil-modified polyol having 3 or more hydroxyl groups and a polyether polyol having 3 or more hydroxyl groups are preferable from the viewpoint of sustained release performance.

When the polyol component contains a compound having 3 or more hydroxyl groups, the content of the compound having 3 or more hydroxyl groups in the polyol component is 2% by weight or more based on the total amount of the polyol component from the viewpoint of sustained release performance. It may be 3% by weight or more, or 8% by weight or more. The content of the compound having three or more hydroxyl groups may be 87% by weight or less, 80% by weight or less, and 76% by weight or less based on the total amount of the polyol component from the viewpoint of sustained release performance. It may be 60% by weight or less, 40% by weight or less, or 20% by weight or less.

In one embodiment, the polyol component may be a mixture of castor oil-modified diol, an alkylene diol having 2 to 8 carbon atoms, and a compound having 3 or more hydroxyl groups.
In this embodiment, the amount of castor oil-modified diol with respect to the total amount of the polyol component may be 7% by weight or more, preferably 10% by weight or more, or 30% by weight or more from the viewpoint of sustained release performance. It may be 50% by weight or more, or 65% by weight or more. The amount of castor oil-modified diol may be 93% by weight or less, or preferably 80% by weight or less, from the viewpoint of sustained release performance.
Further, in this embodiment, the amount of the alkylene diol having 2 to 8 carbon atoms with respect to the total amount of the polyol component may be 4% by weight or more, 6% by weight or more, and 8 by weight, from the viewpoint of sustained release performance. It is preferably 7% by weight or more, or 10% by weight or more. The amount of the alkylene diol having 2 to 8 carbon atoms may be 25% by weight or less, 21% by weight or less, 20% by weight or less, and 18% by weight from the viewpoint of sustained release performance. It may be less than or equal to, or preferably 15% by weight or less. Further, in this embodiment, the amount of the compound having 3 or more hydroxyl groups per molecule with respect to the total amount of the polyol component may be 2% by weight or more, and may be 8% by weight or more from the viewpoint of sustained release performance. preferable. From the viewpoint of sustained release performance, the amount of the polyol having more than 2 hydroxyl groups per molecule may be 87% by weight or less, preferably 78% by weight or less, and may be 60% by weight or less. , 40% by weight or less, or 20% by weight or less.

In another aspect, the urethane resin is a heavy addition of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a castor oil modified diol, an alkylene diol having 2 to 8 carbon atoms, and a polyether polyol. It may be a thing. In the above embodiment, the content of the aromatic polyisocyanate, the castor oil modified diol, the alkylene diol having 2 to 8 carbon atoms and the polyether polyol is 30 to 60 weight by weight with respect to the total amount of the polyisocyanate component and the polyol component, respectively. %, 30-60% by weight, 3-10% by weight, or 2-20% by weight.

In another aspect, the urethane resin is a heavy addition of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a castor oil-modified diol, an alkylene diol having 2 to 8 carbon atoms, and a castor oil-modified polyol. It may be a thing. In the above embodiment, the contents of the aromatic polyisocyanate, the castor oil-modified diol, the alkylene diol having 2 to 8 carbon atoms and the castor oil-modified polyol are 30 to 60, respectively, with respect to the total amount of the polyisocyanate component and the polyol component. It may be% by weight, 5 to 60% by weight, 3 to 10% by weight, or 5 to 50% by weight.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a polyether polyol and castor oil. In the above embodiment, the contents of the aromatic polyisocyanate, the polyether polyol and the castor oil are 30 to 60% by weight, 5 to 60% by weight, or 5 to 5 to 60% by weight, respectively, with respect to the total amount of the polyisocyanate component and the polyol component. It may be 30% by weight.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a polyether polyol. In the above embodiment, the content of the aromatic polyisocyanate and the polyether polyol may be 30 to 60% by weight or 30 to 60% by weight, respectively, with respect to the total amount of the polyisocyanate component and the polyol component.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a polyether diol and a polyether polyol. In the above embodiment, the content of the aromatic polyisocyanate, the polyether diol and the polyether polyol is 30 to 60% by weight, 5 to 30% by weight, or 5 with respect to the total amount of the polyisocyanate component and the polyol component, respectively. It may be up to 60% by weight.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aliphatic polyisocyanate and a polyol component containing a polyether diol and a polyether polyol. In the above embodiment, the content of the aliphatic polyisocyanate, the polyether diol and the polyether polyol is 30 to 60% by weight, 5 to 30% by weight, or 5 with respect to the total amount of the polyisocyanate component and the polyol component, respectively. It may be up to 60% by weight.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing a castor oil-modified polyol. In the above embodiment, the content of the aromatic polyisocyanate and the castor oil-modified polyol may be 20 to 70% by weight or 20 to 70% by weight, respectively, with respect to the total amount of the polyisocyanate component and the polyol component.

Further, in another embodiment, the urethane resin may be a heavy adduct of a polyisocyanate component containing an aromatic polyisocyanate and a polyol component containing castor oil-modified diliol. In the above embodiment, the content of the aromatic polyisocyanate and the castor oil-modified diliol may be 20 to 70% by weight or 20 to 70% by weight, respectively, based on the total amount of the polyisocyanate component and the polyol component.

In another aspect, the urethane resin comprises 30 to 60 parts by weight of aromatic polyisocyanate, 30 to 60 parts by weight of castor oil modified diol, and 3 to 10 parts by weight of alkylene diol having 2 to 8 carbon atoms. It may be a heavy adduct of 2 to 20 parts by weight of a polyether polyol.

In another aspect, the urethane resin comprises 30 to 60 parts by weight of aromatic polyisocyanate, 5 to 60 parts by weight of castor oil-modified diol, and 3 to 10 parts by weight of alkylene diol having 2 to 8 carbon atoms. It may be a heavy adduct of 5 to 50 parts by weight of castor oil-modified polyol.

In another aspect, the urethane resin is a heavy adduct of 30 to 60 parts by weight of aromatic polyisocyanate, 5 to 60 parts by weight of a polyether polyol and 5 to 30 parts by weight of castor oil. It's okay.

Further, in another aspect, the urethane resin may be a heavy adduct of 30 to 60 parts by weight of an aromatic polyisocyanate and 30 to 60 parts by weight of a polyether polyol.

In another embodiment, the urethane resin is a heavy adduct of 30 to 60 parts by weight of aromatic polyisocyanate, 5 to 30 parts by weight of a polyether diol and 5 to 60 parts by weight of a polyether polyol. It may be there.

In another embodiment, the urethane resin is a heavy adduct of 30 to 60 parts by weight of an aliphatic polyisocyanate, 5 to 30 parts by weight of a polyether diol, and 5 to 60 parts by weight of a polyether polyol. It may be there.

The ratio M2 / M1 of the number of moles of hydroxyl groups M2 of the polyol component to the number of moles of isocyanate groups M1 of the polyisocyanate component is preferably 0.7 or more, more preferably 0.9 or more. It is preferably 1.7 or less, and more preferably 1.5 or less. When the ratio M2 / M1 is in the above range, excellent sustained release performance tends to be obtained.

The coated granular fertilizer of the present invention may have a resin film other than the urethane resin film. In that case, the content of the urethane resin in the entire resin film may be 80% by weight or more, 90% by weight or more, or 100% by weight based on the total amount of the resin film.

The content of the urethane resin in the coated granular fertilizer is preferably 1 part by mass or more, and more preferably 2 parts by mass or more with respect to 100 parts by mass of the granular fertilizer. The content of the urethane resin is preferably 20 parts by mass or less, or more preferably 16 parts by mass or less, based on 100 parts by mass of the granular fertilizer.

In the method for producing a resin-coated granular fertilizer of the present invention, a polyisocyanate component, a polyol component, and diazabicyclononen are used. Examples of the steps using these components include those shown below, and the method for producing a resin-coated granular fertilizer of the present invention may include these steps.
A step of mixing a polyisocyanate component, a polyol component, and diazabicyclononen to obtain a mixture (A-1), and a step of adding the mixture obtained in step A-1 to a granular fertilizer in a rolling state (A-2). ), A step of forming a urethane resin film on the surface of the granular fertilizer by adding a polyisocyanate component and a polyol component in a layered manner by maintaining the rolling state of the granular fertilizer (A-3) (hereinafter, step A-1). ~ A-3 may be collectively referred to as “process A”).
A step of mixing the polyisocyanate component and the polyol component to obtain a mixture (B-1), and a step of separately adding the mixture obtained in step B-1 and diazabicyclononen to the granular fertilizer in a rolling state (B-1). B-2), a step (B-3) (hereinafter referred to as a step) of forming a urethane resin film on the surface of the granular fertilizer by repeatedly adding a polyisocyanate component and a polyol component by maintaining the rolling state of the granular fertilizer. B-1 to B to 3 may be collectively referred to as "process B").
A step of mixing the polyol component and diazabicyclononen to obtain a mixture (C-1), and a step of separately adding the mixture obtained in step C-1 and the polyisocyanate component to the granular fertilizer in a rolling state (C-1). C-2), a step (C-3) (hereinafter referred to as a step) of forming a urethane resin film on the surface of the granular fertilizer by repeatedly adding a polyisocyanate component and a polyol component by maintaining the rolling state of the granular fertilizer. C-1 to C-3 may be collectively referred to as "process C").
The step of separately adding the polyisocyanate component, the polyol component, and diazabicyclononen to the granular fertilizer in the rolling state (D-1), and the polyisocyanate component and the polyol component by maintaining the rolling state of the granular fertilizer. (D-2) (hereinafter, steps D-1 to D-2 may be collectively referred to as "step D") to form a urethane resin film on the surface of the granular fertilizer. May be. When the polyisocyanate component, the polyol component, and the diazabicyclononen are added separately, the order of addition is the polyisocyanate component, the polyol component, and the diazabicyclononen, the polyol component, the polyisocyanate component, and the diazabicyclononen. , Polyol component, diazabicyclononen, and polyisocyanate component, polyisocyanate component, diazabicyclononen, and polyol component, diazabicyclononen, polyisocyanate component, and polyol component, or diah. It may be any of the order of the zabicyclononen, the polyol component, and the polyisocyanate component.
The temperature at which the step A is carried out is appropriately set according to the types of the polyisocyanate component and the polyol component used, the size of the granular fertilizer, and the like, but in a rotary tank in which the granular fertilizer is in a rolling state. The temperature is usually in the range of 40 to 100 ° C, preferably in the range of 55 to 75 ° C. Further, after the addition of the mixture of the polyisocyanate component, the polyol component and the diazabicyclononene, the heavy addition of the polyisocyanate component and the polyol component progresses to cure the urethane, and the resin-coated granules do not adhere to each other. Although the rolling state of the granular fertilizer is maintained, the time for maintaining the rolling state is usually about 1 to 30 minutes, preferably about 1 to 20 minutes from the viewpoint of production efficiency.
The temperature at which step B is carried out is appropriately set according to the types of the polyisocyanate component and the polyol component used, the size of the granular fertilizer, and the like, but in a rotary tank in which the granular fertilizer is in a rolling state. The temperature is usually in the range of 40 to 100 ° C, preferably in the range of 55 to 75 ° C. Further, after the addition of the mixture of the polyisocyanate component and the polyol component and diazabicyclononen, the heavy addition of the polyisocyanate component and the polyol component proceeds to cure the urethane, and the resin-coated granules do not adhere to each other. Although the rolling state of the granular fertilizer is maintained, the time for maintaining the rolling state is usually about 2 to 40 minutes, preferably about 2 to 30 minutes from the viewpoint of production efficiency.
The temperature at which step C is carried out is appropriately set according to the types of the polyisocyanate component and the polyol component used, the size of the granular fertilizer, and the like, but in a rotary tank in which the granular fertilizer is in a rolling state. The temperature is usually in the range of 40 to 100 ° C, preferably in the range of 55 to 75 ° C. Further, after the addition of the mixture of the polyol component and the diazabicyclononen and the polyisocyanate component, the heavy addition of the polyisocyanate component and the polyol component proceeds to cure the urethane, and the resin-coated granules do not adhere to each other. The rolling state of the granular fertilizer is maintained until, but the time for maintaining the rolling state is usually about 2 to 40 minutes, and from the viewpoint of production efficiency, it is about 2 to 30 minutes.
The temperature at which step D is carried out is appropriately set according to the types of the polyisocyanate component and the polyol component used, the size of the granular fertilizer, and the like, but in a rotary tank in which the granular fertilizer is in a rolling state. The temperature is usually in the range of 40 to 100 ° C, preferably in the range of 55 to 75 ° C. Further, after the addition of the polyisocyanate component, the polyol component and diazabicyclononen, the polyisocyanate component, the polyol component and the heavy addition proceed to the extent that the urethane is cured and the resin-coated granules do not adhere to each other. The rolling state of the granular fertilizer is maintained, but the time for maintaining the rolling state is usually about 2 to 40 minutes, and from the viewpoint of production efficiency, it is about 2 to 30 minutes.

The coated granular fertilizer of the present invention can be produced by a production method including any of the above steps A to D, but step A is preferable from the viewpoint of homogeneity of the resin film.

In the method for producing a resin-coated granular fertilizer of the present invention, any one of the above steps A to D may be performed only once. Further, any of the steps A to D may be repeated once or more on the resin-coated granules obtained by any of the steps A to D (hereinafter, may be referred to as "step E"). Here, the steps A to D to be added repeatedly may be the same as or different from the one-time or a plurality of steps A to D performed earlier. By adjusting the number of times the step E is performed, the thickness of the resin film can be adjusted.
Step E may be continuously carried out while maintaining the rolling state of the granular fertilizer in the previous step. The polyisocyanate component and the polyol component used in the step E may be the same as or different from the polyisocyanate component and the polyol component used in the previous step, but are usually of the same type from the viewpoint of production efficiency. Ingredients and polyol components are used.

The total amount of the polyol component and the polyisocyanate component used in the method for producing a resin-coated granular fertilizer of the present invention is appropriately determined depending on the size and shape of the granular fertilizer used and the degree of elution control required for the resin-coated granular fertilizer to be produced. Although it is set, it is the total amount of the polyol component and the polyisocyanate used in steps A to D and, if necessary, step E, and is usually 2 to 30 weights per 100 parts by weight of granular fertilizer. About parts, preferably about 4 to 18 parts by weight.

As a method for putting the granular fertilizer into a rolling state, there is no particular limitation on the device, and known and conventional ones can be used. Examples of such an apparatus include a concrete mixer and a drum mixer. Among the above-mentioned devices, the device equipped with the heating equipment is preferably used because it is possible to improve the accuracy and adjust the processing time in the manufacturing method of the present invention.

The coated granular fertilizer of the present invention may further contain a resin film other than the resin film containing urethane resin and diazabicyclononen, which are heavy adducts of the polyisocyanate component and the polyol component. Examples of such a resin film include a film containing urethane resin, which is a heavy adduct of an arbitrary polyisocyanate component and an arbitrary polyol component, and not containing diazabicyclononen.
The resin film may further contain components other than the urethane resin and diazabicyclononen. For example, it may contain a solvent such as an organic solvent and water, and these may be the solvents used in the production of the urethane resin. Further, the resin film may further contain a pigment, a dye, an antibacterial agent, a preservative, a plasticizer, a decomposition accelerator, the above-mentioned carrier and the like, depending on the purpose.

The coated granular fertilizer of the present invention may further contain components other than the granular fertilizer and the resin film (for example, antifloating material, anti-caking material, pesticide active ingredient, waxes, etc.).

The coated granular fertilizer of the present invention may further contain a hydrophobic liquid compound having a boiling point of 100 ° C. or higher (hereinafter, also referred to as "the present hydrophobic liquid compound"). In the present invention, the present hydrophobic liquid compound means a compound having fluidity at 20 ° C. and having a water solubility at 20 ° C. of 10 ppm or less. The present hydrophobic liquid compound may be contained in the granular fertilizer and may be present as a film covering the granular fertilizer. When the present hydrophobic liquid compound is present as a film, the film may be formed directly on the surface of the granular fertilizer, or may be formed on the resin film covering the granular fertilizer.

This hydrophobic compound is blended, for example, when producing a resin-coated granular fertilizer using an apparatus that puts the granular fertilizer in a rolling state. Examples of the hydrophobic compound include aliphatic hydrocarbons such as liquid paraffin, aromatic hydrocarbons such as phenylxysilylethane and alkylbenzene (specifically, Solvesso150, manufactured by Exxon Mobile Chemical). The content of the hydrophobic liquid compound in the resin-coated granular fertilizer may be 0.1 to 5 parts by mass with respect to 100 parts by mass of the granular fertilizer.

The resin film may be formed directly on the surface of the granular fertilizer. When a film other than the resin film (for example, a film of the above-mentioned hydrophobic liquid compound) is formed on the surface of the granular fertilizer, a resin film may be formed on the film.

The resin film may be formed so as to cover the entire surface of the granular fertilizer, or may be formed so as to cover a part of the surface of the granular fertilizer.

The thickness of the resin coating can be appropriately selected according to the use and purpose of use of the resin-coated granular fertilizer. The thickness of the resin film may be, for example, 8 μm or more, preferably 10 μm or more. The thickness of the resin film may be, for example, 400 μm or less, preferably 200 μm or less. According to one embodiment, the thickness of the resin coating is 8 μm or more and 4200 μm or less, 8 μm or more and 200 μm or less, 10 μm or more and 400 μm or less, or 10 μm or more and 200 μm or less. .. In the present specification, the thickness of the resin coating indicates a value measured by a scanning electron microscope (SEM) observation of a cross section of the resin-coated granular fertilizer. The thickness of the resin film can also be expressed as, for example, the average value of the measured values of the thicknesses at 10 points. By adjusting the thickness of the resin film, for example, the elution amount of the fertilizer component and the shape of the elution curve can be adjusted.

The particle size of the coated granular fertilizer can be appropriately selected according to the intended use and purpose of use of the coated granular fertilizer. For example, the average particle size of the coated particle size fertilizer may be 0.1 to 15 mm, or may be 1 to 5 mm. In the present specification, the average particle size of the coated granular fertilizer is defined as an arithmetic mean value of the diameter corresponding to the projected area circle, and is measured by a microscope method or the like.

Next, the present invention will be described in more detail with reference to examples such as manufacturing examples, but the present invention is not limited to these examples.

Production Example 1
Himashi oil-modified diol (manufactured by Ito Oil Co., Ltd., trade name: URIC H-62, number of hydroxyl groups per molecule: 2, hydroxyl value: 274), Himashi oil-modified polyol (manufactured by Ito Oil Co., Ltd., trade name: URIC H) -73X, number of hydroxyl groups per molecule: 3, hydroxyl value: 270), 1,4-butanediol (manufactured by BASF Idemitsu Co., Ltd., trade name: 1,4-BDO) 67.8: 20.8: 11 The mixture was mixed in an arbitrary amount at a weight ratio of 4 at room temperature to obtain a polyol mixture A. Then, 2677.08 g of the obtained polyol mixture and 2.50 g of diazabicyclononen (trade name: DBN) were mixed at room temperature to obtain a polyol mixture I.
50,000 g of granular urea (large-grain urea, particle size of about 3 mm, spherical shape, about 60 grains per 1 g) was charged into a concrete mixer and put into a rolling state. The granular urea in a rolling state is heated to about 66 ° C. by applying hot air from a hot air generator, and then liquid paraffin (manufactured by Matsumura Petroleum Research Institute, trade name: Moresco White P-350P, 37.78 ° C.). Viscosity: 76 mm ² / S) 500 g was added and the rolling state was maintained for 3 minutes. Next, 267.96 g of the polyol mixture I heated to 50 ° C. and 232.29 g of aromatic diisocyanate (manufactured by Sumika Bayer Urethane, trade name: SBU isocyanate J243) heated to 50 ° C. are quickly stirred and mixed. The obtained mixture was added to the granular urea in the rolling state, and the rolling state was maintained while applying hot air from the hot air generator for 7 minutes or more. The above operation (stirring and mixing of polyol mixture I and aromatic diisocyanate, addition of the mixture to granular urea in a rolling state, until the total addition amount of the mixture of polyol mixture I and aromatic diisocyanate reaches 5,002.5 g, And maintenance of the rolling state) was repeated to obtain the coated granular fertilizer of the present invention.
In the above manufacturing process, no remarkable agglomeration of the granules and adhesion of the granules to the inner wall of the concrete mixer were observed, and the rolling state of the granules in the concrete mixer was good. Moreover, when the coated granular fertilizer obtained by the above manufacturing process was visually observed, the coated state was uniform.

Manufacturing example 2
50,000 g of granular urea (large-grain urea, particle size of about 3 mm, spherical shape, about 60 grains per 1 g) was charged into a concrete mixer and put into a rolling state. The granular urea in a rolling state is heated to about 66 ° C. by applying hot air from a hot air generator, and then liquid paraffin (manufactured by Matsumura Petroleum Research Institute, trade name: Moresco White P-350P, 37.78 ° C.). Viscosity: 76 mm ² / S) 500 g was added, and the rolling state was continued for 3 minutes. Next, the polyol mixture I heated to 50 ° C. I200.97 g and aromatic diisocyanate (manufactured by Sumika Bayer Urethane, trade name: SBU isocyanate J243) 174.22 g heated to 50 ° C. were quickly stirred and mixed to obtain the mixture. The mixture was added to the granular urea in the rolling state, and the rolling state was maintained while applying hot air from the hot air generator for 6 minutes or more. The above operation (stirring mixing of polyol mixture I and aromatic diisocyanate, addition of the mixture to granular urea in a rolling state, until the total addition amount of the mixture of polyol mixture I and aromatic diisocyanate reaches 4,877.47 g, And maintenance of the rolling state) was repeated to obtain the coated granular fertilizer of the present invention.
Through the above manufacturing process, no remarkable agglomeration of the granules and adhesion of the granules to the inner wall of the concrete mixer were observed, and the rolling state of the granules in the concrete mixer was good. Moreover, when the coated granular fertilizer obtained by the above manufacturing process was visually observed, the coated state was uniform.

Production example 3
A polyol mixture A2677.08 g and diazabicyclononen (San Apro Co., Ltd., trade name: DBN) 3.50 g were mixed at room temperature to obtain a polyol mixture II.
50,000 g of granular urea (large-grain urea, particle size of about 3 mm, spherical shape, about 60 grains per 1 g) was charged into a concrete mixer and put into a rolling state. The granular urea in a rolling state is heated to about 66 ° C. by applying hot air from a hot air generator, and then liquid paraffin (manufactured by Matsumura Petroleum Research Institute, trade name: Moresco White P-350P, 37.78 ° C.). Viscosity: 76 mm ² / S) 500 g was added, and the rolling state was continued for 3 minutes. Next, 268.06 g of the polyol mixture heated to 50 ° C. and 232.29 g of aromatic diisocyanate (manufactured by Sumika Bayer Urethane, trade name: SBU isocyanate J243) heated to 50 ° C. are quickly stirred and mixed. The mixture was added to the granular urea in the rolling state, and the rolling state was maintained while applying hot air from the hot air generator for 7 minutes or more. The above operation (stirring and mixing of polyol mixture II and aromatic diisocyanate, addition of the mixture to granular urea in a rolling state, until the total addition amount of the mixture of polyol mixture II and aromatic diisocyanate reaches 5,003.5 g, And maintenance of the rolling state) was repeated to obtain the coated granular fertilizer of the present invention.
Through the above manufacturing process, no remarkable agglomeration of the granules and adhesion of the granules to the inner wall of the concrete mixer were observed, and the rolling state of the granules in the concrete mixer was good. Moreover, when the coated granular fertilizer obtained by the above manufacturing process was visually observed, the coated state was uniform.

Comparative manufacturing example 1
50,000 g of granular urea (large-grain urea, particle size of about 3 mm, spherical shape, about 60 grains per 1 g) was charged into a concrete mixer and put into a rolling state. The granular urea in a rolling state is heated to about 66 ° C. by applying hot air from a hot air generator, and then liquid paraffin (manufactured by Matsumura Petroleum Research Institute, trade name: Moresco White P-350P, 37.78 ° C.). Viscosity: 76 mm ² / S) 500 g was added, and the rolling state was continued for 3 minutes. Next, 267.71 g of the polyol mixture heated to 50 ° C. and 232.29 g of aromatic diisocyanate (manufactured by Sumika Bayer Urethane, trade name: SBU isocyanate J243) heated to 50 ° C. are quickly stirred and mixed. The mixture was added to the granular urea in the rolling state, and the rolling state was maintained while applying hot air from the hot air generator for 9 minutes or more. The above operation (stirring and mixing of polyol mixture A and aromatic diisocyanate, addition of the mixture to granular urea in a rolling state, until the total addition amount of the mixture of polyol mixture A and aromatic diisocyanate reaches 5,000.0 g, And maintenance of the rolling state) was repeated to obtain a coated granular fertilizer for comparison.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

Comparative manufacturing example 2
A polyol mixture A 2677.08 g and an ethyleneamine derivative (Tosoh Corporation, trade name: TOYOCAT-DB30) 2.50 g were mixed at room temperature to obtain a polyol mixture III.
The same operation as in Production Example 1 was carried out except that the polyol mixture III was used instead of the polyol mixture I, and a coated granular fertilizer for comparison was obtained.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

Comparative manufacturing example 3
Mixture A 2677.08 g and 2.50 g of 1,8-diazabicyclo (5.4.0) Undecen-7 (San Apro Co., Ltd., trade name: DBU®) at room temperature to obtain a polyol mixture IV. Obtained.
The same operation as in Production Example 1 was carried out except that the polyol mixture IV was used instead of the polyol mixture I, and a coated granular fertilizer for comparison was obtained.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

Comparative manufacturing example 4
Mixture A 2677.08 g and 3.50 g of 1,8-diazabicyclo (5.4.0) Undecen-7 (San Apro Co., Ltd., trade name: DBU®) at room temperature to obtain a polyol mixture V. Obtained.
The same operation as in Production Example 3 was carried out except that the polyol mixture V was used instead of the polyol mixture II, and a coated granular fertilizer for comparison was obtained.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

Comparative manufacturing example 5
2.50 g of the polyol mixture A 2677.08 g and the phenol salt of 1,8-diazabicyclo (5,4,0) undecene-7 (San Apro Co., Ltd., trade name: U-CAT (registered trademark) SA-1) at room temperature. The mixture was obtained with a polyol mixture VI.
The same operation as in Production Example 1 was carried out except that the polyol mixture VI was used instead of the polyol mixture I, and a coated granular fertilizer for comparison was obtained.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

Comparative manufacturing example 6
A polyol mixture A 2677.08 g and 2,4,6-tris (dimethylaminomethyl) phenol (chemical drug Axo Co., Ltd., trade name: TAP) 25.0 g were mixed at room temperature to obtain a polyol mixture VII.
50,000 g of granular urea (large-grain urea, particle size of about 3 mm, spherical shape, about 60 grains per 1 g) was charged into a concrete mixer and put into a rolling state. The granular urea in a rolling state is heated to about 66 ° C. by applying hot air from a hot air generator, and then liquid paraffin (manufactured by Matsumura Petroleum Research Institute, trade name: Moresco White P-350P, 37.78 ° C.). Viscosity: 76 mm ² / S) 500 g was added, and the rolling state was continued for 3 minutes. Next, the polyol mixture VII270.21 g heated to 50 ° C. and 232.29 g of aromatic diisocyanate (manufactured by Sumika Bayer Urethane, trade name: SBU isocyanate J243) heated to 50 ° C. were rapidly stirred and mixed. The mixture was added to the granular urea in the rolling state, and the rolling state was maintained while applying hot air from the hot air generator for 10 minutes or more. Until the total amount of the mixture of polyol mixture VII and aromatic diisocyanate added reaches 5025.0 g, the above operations (stirring and mixing of polyol mixture VII and aromatic diisocyanate, addition of the mixture to granular urea in a rolling state, and (Maintenance of rolling state) was repeated to obtain a coated granular fertilizer for comparison.
In the above manufacturing process, agglomerated lumps of granules were partially observed, and the rolling state of the granules in the concrete mixer was not sufficient.

According to the method for producing a coated granular fertilizer of the present invention, it is possible to provide a coated granular fertilizer in which the occurrence of aggregation between particles and adhesion of particles to a rolling device is suppressed.

Claims (11)

A method for producing a coated granular fertilizer comprising a granular fertilizer and a urethane resin coating for coating the granular fertilizer.
A step of adding a polyisocyanate component, a polyol component, and diazabicyclononen to the granular fertilizer in a rolling state; and a weighting of the polyisocyanate component and the polyol component while maintaining the rolling state of the granular fertilizer. A method for producing a coated granular fertilizer, which comprises a step of forming the urethane resin film on the surface of the granular fertilizer by adding the mixture. The production method according to claim 1, wherein the amount of diazabicyclononen added is 0.01 to 2% by weight based on the total amount of the polyisocyanate component and the polyol component. The manufacturing method according to claim 1 or 2, which comprises the following steps:
(A) A step of mixing a polyisocyanate component, a polyol component, and diazabicyclononen to obtain a mixture.
(B) The step of adding the mixture obtained in the above step (a) to the granular fertilizer in the rolling state, and (c) maintaining the rolling state of the granular fertilizer, and adding the polyisocyanate component and the polyol component repeatedly. The process of forming a resin film on the surface of granular fertilizer. The manufacturing method according to claim 1 or 2, which comprises the following steps:
(A) A step of mixing a polyisocyanate component and a polyol component to obtain a mixture.
(B) A step of separately adding the mixture obtained in the above step (a) and diazabicyclononen to the granular fertilizer in a rolling state, and (c) maintaining the rolling state of the granular fertilizer and polyisocyanate. A process of forming a resin film on the surface of granular fertilizer by adding components and polyol components in layers. The manufacturing method according to claim 1 or 2, which comprises the following steps:
(A) A step of mixing a polyol component and diazabicyclononen to obtain a mixture.
(B) A step of separately adding the polyisocyanate component and the mixture obtained in the above step (a) to the granular fertilizer in the rolling state, and (c) maintaining the rolling state of the granular fertilizer and the polyisocyanate component. And a polyol component are heavily added to form a resin coating on the surface of granular fertilizer. The manufacturing method according to claim 1 or 2, which comprises the following steps:
(A) A step of separately adding a polyisocyanate component, a polyol component, and diazabicyclononen to a granular fertilizer in a rolling state, and (b) maintaining the rolling state of the granular fertilizer, a polyisocyanate component and a polyol. A process of forming a resin film on the surface of granular fertilizer by adding components in layers. The production method according to any one of claims 1 to 6, wherein the polyisocyanate component contains an aromatic polyisocyanate. The production method according to any one of claims 1 to 7, wherein the polyol component contains castor oil-modified diol. One of claims 1 to 7, wherein the polyol component contains two or more compounds selected from the group consisting of castor oil-modified diols, alkylene diols having 2 to 8 carbon atoms, and compounds having 3 or more hydroxyl groups. The manufacturing method described in. The production method according to any one of claims 1 to 8, wherein the polyol component contains a castor oil-modified diol, an alkylene diol having 2 to 8 carbon atoms, and a compound having 3 or more hydroxyl groups. It is provided with a granular fertilizer and a resin film that covers the granular fertilizer.
A coated granular fertilizer in which the resin film contains urethane resin and diazabicyclononen, which are heavy adducts of a polyisocyanate component and a polyol component.