JPS5935873B2 - Manufacturing method for slow-release coated fertilizer - Google Patents

Description

【発明の詳細な説明】 本発明は、緩効性被覆肥料の製造方法に関し、更に詳し
くは、粒状肥料の表面を初めに難溶性肥料塩で被覆（内
層）し、次いでその上に有機資材を被覆（外層）するこ
とを特徴とする著しく耐溶出性を向上させた緩効性被覆
肥料の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a slow-release coated fertilizer, and more specifically, the surface of a granular fertilizer is first coated (inner layer) with a sparingly soluble fertilizer salt, and then an organic material is applied thereon. The present invention relates to a method for producing a slow-release coated fertilizer with significantly improved elution resistance characterized by coating (outer layer).

一般的に使用される速効性肥料は、本質的に水溶性であ
るため施与後は降雨時の流出量が大で、農作物の必要養
分をその生長に合わせて供給しようとすれば、数回に分
ける分肥施与を行なわなければならないことになる。Commonly used fast-acting fertilizers are essentially water-soluble, so after application, there is a large amount of runoff during rainfall, and if you want to supply the necessary nutrients to crops as they grow, you will need to apply them several times. This means that fertilizer application will have to be divided into two parts.

また、溶脱量の比較的少ない条件下にある場合でも一度
に多量の速効性肥料を施せば、農作物に肥料過多による
障害を与える事が考えられる。Furthermore, even under conditions where the amount of leaching is relatively small, if a large amount of quick-release fertilizer is applied at once, it is possible that agricultural crops will be damaged by excessive fertilizer.

近年、これら速効性肥料の欠点を補った緩効性肥料の開
発が進められ、種々の提案がなされている。In recent years, efforts have been made to develop slow-release fertilizers that compensate for the shortcomings of these quick-release fertilizers, and various proposals have been made.

即ち、（１）粒状肥料にＭｇＯ、リン酸アンモニウム及
び濃厚リン酸液でリン酸マグネシウム被膜を形成する方
法、粒状肥料にＭｇ（ＯＲ）２、希薄リン酸液でリン酸
マグネシウム被膜を形成する方法（米国特許第３３９２
００７号、特公昭４９−１７８２６号公報）、（２）粒
状肥料に有機資材、例えば硬化油と蜜蝋との混合物、ニ
トロフミン酸、またはその塩、セルロース類、樹脂類等
で被膜を形成する方法（特公昭４０−２７２８３号公報
、特公昭４３−７８１’３号公報）等が提案されている
が、上記（１）に記載の方法では、被覆膜はピンホール
が避けられず、長期にわたって緩効性を有するとはいい
難く、ある期間をすぎればピンホール部の拡大により急
速に溶出するという欠点があるし、また上記（２）に記
載の方法では、有機資材は水中での機械的強度が弱く、
且、被覆膜の保形性が乏しいため長期にわたる溶出抑制
効果の維持ができないことや、比較的耐水性のあるもの
は高価であるため実用的でない等の欠点がある。That is, (1) a method of forming a magnesium phosphate film on a granular fertilizer with MgO, ammonium phosphate, and a concentrated phosphoric acid solution; a method of forming a magnesium phosphate film on a granular fertilizer with Mg(OR)2 and a dilute phosphoric acid solution; (U.S. Patent No. 3392
007, Japanese Patent Publication No. 49-17826), (2) A method of forming a film on granular fertilizer with an organic material such as a mixture of hydrogenated oil and beeswax, nitrofumic acid or its salts, celluloses, resins, etc. Japanese Patent Publication No. 40-27283, Japanese Patent Publication No. 43-781'3), etc. have been proposed, but with the method described in (1) above, pinholes are unavoidable in the coating film, and the coating film does not loosen over a long period of time. It is difficult to say that the organic material is effective, and has the disadvantage that it rapidly dissolves after a certain period of time due to expansion of the pinhole area.Also, in the method described in (2) above, the organic material has poor mechanical strength in water. is weak,
In addition, there are drawbacks such as the inability to maintain the elution suppressing effect over a long period of time due to the poor shape retention of the coating film, and the fact that those that are relatively water resistant are expensive and therefore impractical.

そこで、本発明者等は、上記のような欠点のない緩効性
肥料を提供すべく研究を行なった結果、リン酸アンモニ
ウムマグネシウムと有機資材とを組合せて被覆すること
により、それぞれを単独被覆する場合に比して相乗の効
果が奏せられることを発見し、それに基づいて次のよう
な発明をするに到った。Therefore, the present inventors conducted research to provide a slow-release fertilizer that does not have the above drawbacks, and found that by coating ammonium magnesium phosphate and organic materials in combination, it is possible to coat each of them individually. They discovered that a synergistic effect can be produced compared to the conventional case, and based on this discovery, they came up with the following invention.

即ち、粒状肥料上に、初めに１種又は２種以上のリン酸
アンモニウムマグネシウムからなる難溶性肥料塩を化学
反応により生成させながら内層（１層又は２層以上）被
覆し、次いで、その上に１種又は２種以上の有機資材で
外層（１層又は２層以上）被覆するものである。That is, the granular fertilizer is first coated with an inner layer (one layer or two or more layers) of a sparingly soluble fertilizer salt consisting of one or more types of ammonium magnesium phosphate by chemical reaction, and then an inner layer (one layer or two or more layers) is coated on the granular fertilizer. The outer layer (one or more layers) is coated with one or more organic materials.

本発明で使用する難溶性肥料塩はリン酸アンモニウムマ
ク゛纒シウムであり、これらは任意の合成法で調製され
ろ。The sparingly soluble fertilizer salt used in the present invention is ammonium phosphate, which can be prepared by any synthetic method.

また、有機資材にはロジン、パラフィン、塩化パラフィ
ン、硬化油、ボイル油、乾性油等の鉱・植物油類：エチ
ルセルロース、ニトロセルロース等のセルロース類；大
豆変性フタル酸樹脂； 酢酸ビニル系、スチロール系、
フェノール系、尿素系、メラミン系、クマロン系、エポ
キシ系、ポリエステル系、ビニル系、アクリル系、アル
キッド系、キシレン系、ホルムアルデヒド系、ポリオレ
フィン系、ビニール系、スチレン系、ポリアマイド系、
ケイ素系等の合成樹脂類等がある。In addition, organic materials include rosin, paraffin, chlorinated paraffin, mineral and vegetable oils such as hydrogenated oil, boil oil, and drying oil; celluloses such as ethyl cellulose and nitrocellulose; soybean-modified phthalate resin; vinyl acetate, styrene,
Phenol type, urea type, melamine type, coumaron type, epoxy type, polyester type, vinyl type, acrylic type, alkyd type, xylene type, formaldehyde type, polyolefin type, vinyl type, styrene type, polyamide type,
There are synthetic resins such as silicon-based resins.

内層、外層の被覆比（被覆された粒状肥料に対する被覆
物の割合を重量％で表わしたもの）は、それぞれ５〜３
０％、３〜２０％、好ましくは１０〜２０％、５〜１０
％である。The coating ratio of the inner layer and outer layer (the ratio of the coating to the coated granular fertilizer expressed in weight%) is 5 to 3, respectively.
0%, 3-20%, preferably 10-20%, 5-10
%.

リン酸アンモニウムマグネシウムからなる難溶性肥料塩
を肥料粒子上に被覆する手段としては、単にそれらの粉
末を水造粒付着で被覆したのでは後記するような優れた
特性を有する被膜は得られず、表面にリン酸アンモニウ
ムマグネシウムを反応生成被覆したときにおいてのみ堅
牢な緩効性の高い膜を形成する。As a means of coating fertilizer particles with a sparingly soluble fertilizer salt consisting of magnesium ammonium phosphate, simply coating the powder with water granulation does not provide a coating with the excellent properties described below; A robust, slow-release film is formed only when the surface is coated with ammonium magnesium phosphate.

その場合のリン酸アンモニウムマグネシウムの生成手段
は特に限定されろものではなく、易溶性未反応物質が被
覆リン酸アンモニウムマグネシウム層に残存しなければ
いかなる手段でもよいが、好ましい例として次の場合が
挙げられる。In that case, the means for producing ammonium magnesium phosphate is not particularly limited, and any means may be used as long as easily soluble unreacted substances do not remain in the coated ammonium magnesium phosphate layer, but the following is a preferable example. It will be done.

即ち、Ｍｇ（ＯＨ）２又はＭｇＯと ＭｇＨＰＯ４・３Ｈ２０とＮＨ３とを使用し、ＭｇＨＰ
Ｏ４＝１．０〜１．２− ＮＨ３／ＰＯ４＝ ０．８〜
１，０、反応温度６０〜８０℃でＭｇＮＨ４ＰＯ４・Ｈ
２Ｏを生成する場合で、その場合、被覆比が、５〜３０
％好ましくは１０〜２０％のときに最つとも均質で堅牢
な内層被覆層が得られる。That is, using Mg(OH)2 or MgO, MgHPO4.3H20 and NH3, MgHP
O4=1.0~1.2- NH3/PO4=0.8~
1,0, MgNH4PO4・H at reaction temperature 60-80℃
2O is produced, in which case the coverage ratio is 5 to 30
%, preferably from 10 to 20%, provides the most homogeneous and robust inner coating layer.

また、外層の有機資材の被覆手段は、有機溶剤に溶かし
た有機資材を噴霧、乾燥するなどの従来性なわれていた
如何なる手段でも良い。Further, the means for coating the outer layer with the organic material may be any conventional means such as spraying and drying an organic material dissolved in an organic solvent.

その場合、被覆比が３〜２０％好ましくは５〜１０％の
ときに良好な外層が得られる。In that case, a good outer layer is obtained when the coverage ratio is 3 to 20%, preferably 5 to 10%.

上記のようにして、粒状肥料を初めに難溶性肥料塩で内
層被覆し、次いで有機資材で外層被覆することにより、
有機資材として脆弱なパラフィン、硬化油等を用いても
リン酸アンモニウムマグネシウムによる補強効果により
耐水性を上げると共に強度をもたせる事もできる。As described above, by first coating the granular fertilizer with an inner layer of hardly soluble fertilizer salt and then coating the outer layer with an organic material,
Even if fragile paraffin, hydrogenated oil, etc. are used as organic materials, the reinforcement effect of ammonium magnesium phosphate can increase water resistance and provide strength.

また、有機資材として耐水性のものを使用する場合には
、リン酸アンモニウムマグネシウムの膜上な薄く被覆す
ることでピンホールをふさぎ、緩効性を増すことができ
るため経済的でもある。In addition, when using a water-resistant organic material, it is economical because a thin film of ammonium magnesium phosphate can be coated to close pinholes and increase slow-release properties.

更に、リン酸アンモニウムマグネシウムで肥料粒子を内
層被覆した場合には、内層被覆をしない場合に比して肥
料粒子への有機資材の被覆が極めて容易で望む自由な割
合に被覆が可能である。Furthermore, when the fertilizer particles are coated with an inner layer of ammonium magnesium phosphate, it is much easier to coat the fertilizer particles with the organic material than when the inner layer is not coated, and it is possible to coat the fertilizer particles in any desired ratio.

また、リン酸アンモニウムマグネシウムは全てが肥料成
分であり従来の被膜が肥料以外の成分を主としているの
に比べ経済的であるばかりでなく、被膜厚さを自由に調
節して浮上防止を図ることもできる。In addition, since ammonium magnesium phosphate is entirely a fertilizer component, it is not only more economical than conventional coatings that mainly contain ingredients other than fertilizers, but also allows the coating thickness to be freely adjusted to prevent floating. can.

次に、実施例を挙げて本発明を更に詳細に説明する。Next, the present invention will be explained in more detail by giving examples.

実施例 １ 粒状複合肥料（塩加燐安１４−１４−１４、以下粒状肥
料という）Ｉｋｇを回転パン内で転勤せしめながら２７
％リン酸液（Ｐ２Ｏ３として換算）３０７グとＭｇ （
ＯＨ）２粉末７３グを交互に噴霧し、最後にＮＨ３３０
？を添加する手段によりＭｇＮＨ４ＰＯ４・Ｈ２Ｏの内
層被覆を形成した。Example 1 While transferring 1 kg of granular compound fertilizer (Salt and Phosphate 14-14-14, hereinafter referred to as granular fertilizer) in a rotary pan,
% phosphoric acid solution (calculated as P2O3) 307g and Mg (
Spray 73g of OH)2 powder alternately, and finally spray NH330.
? An inner layer coating of MgNH4PO4.H2O was formed by adding .

このようにして得た被覆比１５．５％の粒状肥料（以下
内層被覆品という）の乾燥物１．１８３ｋｇに融点６８
〜７０℃のパラフィンワックスを８０〜９０℃で溶融被
覆し、放冷により外層被覆比的４〜９％、全層被覆比的
１９〜２３％の被覆肥料を得た。1.183 kg of dried granular fertilizer with a coating ratio of 15.5% (hereinafter referred to as inner layer coated product) obtained in this manner has a melting point of 68
Paraffin wax of ~70°C was melted and coated at 80~90°C, and allowed to cool to obtain a coated fertilizer with an outer layer coverage ratio of 4~9% and a total layer coverage ratio of 19~23%.

実施例 ２ 実施例１で得た内層被覆品１ｋｇに硬化（魚）油を用い
て実施例１に記載の手段で外層被覆し、厚さを任意に変
えた被覆肥料を得た。Example 2 1 kg of the inner layer-coated product obtained in Example 1 was coated with an outer layer using hydrogenated (fish) oil by the method described in Example 1 to obtain coated fertilizers with arbitrary thicknesses.

実施例 ３ 実施例１で得た内層被覆品１ｋｇに７０％塩素化パラフ
ィンの２０％トルエン溶液を噴霧、乾燥を（り返し、厚
さを任意に変えた被覆肥料を得た。Example 3 A 20% toluene solution of 70% chlorinated paraffin was sprayed onto 1 kg of the inner layer-coated product obtained in Example 1, and the mixture was dried (repeatedly) to obtain coated fertilizers with arbitrary thicknesses.

実施例 ４ 実施例１で得た内層被覆品１ｋｇに実施例３に記載の手
段でエチルセルロース（２０％エタノール溶液）を被覆
し、被覆肥料を得た。Example 4 1 kg of the inner layer coated product obtained in Example 1 was coated with ethyl cellulose (20% ethanol solution) by the method described in Example 3 to obtain a coated fertilizer.

実施例 ５ 実施例１で得た内層被覆品１ｋｇに実施例３に記載の手
段でアルキッド樹脂（５０％ミネラルスピリット溶液）
を被覆し、被覆肥料を得た。Example 5 1 kg of the inner coated product obtained in Example 1 was treated with alkyd resin (50% mineral spirit solution) by the method described in Example 3.
was coated to obtain a coated fertilizer.

比較例 １〜５ 実施例１〜５の各々について内層 ＭｇＮＨ４ＰＯ４・Ｈ２Ｏを被覆せずに有機資材層を直
接被覆する手段で厚さを任意に変えた被覆肥料を得た。Comparative Examples 1 to 5 For each of Examples 1 to 5, coated fertilizers with arbitrary thicknesses were obtained by directly coating the organic material layer without coating the inner layer MgNH4PO4.H2O.

なお、このとき使用した粒状肥料のサイズ・硬度は実施
例１〜５の内層被覆品と同程度のものでおこなった。Note that the size and hardness of the granular fertilizer used at this time were similar to those of the inner layer coated products of Examples 1 to 5.

実施例 ６ 尿素入り塩加燐安５２５号（１５−１２−１５）１ｋｇ
を実施例１に記載の方法で被覆し、内層被覆比１５．５
％、外層被覆比４〜１０％の被覆肥料を得た。Example 6 Salted Rin-an No. 525 (15-12-15) containing urea 1 kg
was coated by the method described in Example 1, and the inner layer coverage ratio was 15.5.
%, and a coated fertilizer with an outer layer coverage ratio of 4 to 10% was obtained.

実施例 ７ 実施例６で得た内層被覆品に、実施例１に記載の手段で
硬化（魚）油を用いて外層被覆し、厚さを任意に変えた
被覆製品を得た。Example 7 The inner layer-coated product obtained in Example 6 was coated with an outer layer using hardened (fish) oil by the method described in Example 1 to obtain coated products with arbitrary thicknesses.

実施例 ８ 実施例６で得た内層被覆品に７０％塩素化パラフィンの
２０％トルエン溶液を噴霧、乾燥をくり返し、厚さを任
意に変えた被覆製品を得た。Example 8 A 20% toluene solution of 70% chlorinated paraffin was sprayed onto the inner layer-coated product obtained in Example 6, and drying was repeated to obtain coated products with arbitrary thicknesses.

実施例 ９ ７０％塩素化パラフィンの２０％トルエン溶液に代えて
エチルセルロースの２０％エタノール溶液を用いて、実
施例８に記載の方法で厚さを任意に変えた被覆製品を得
た。Example 9 Coated products of arbitrary thickness were obtained by the method described in Example 8, using a 20% ethanol solution of ethyl cellulose instead of a 20% toluene solution of 70% chlorinated paraffin.

比較例 ６〜９ 実施例６〜９の各々について内層 ＭｇＮＩ（４ＰＯ４・Ｈ２Ｏを被覆せずに有機資材層を
直接被覆する手段で厚さを任意に変えた被覆肥料を得た
。Comparative Examples 6 to 9 For each of Examples 6 to 9, coated fertilizers with arbitrary thicknesses were obtained by directly coating the organic material layer without coating the inner layer MgNI (4PO4.H2O).

なお、このとき使用した粒状肥料のサイズ・硬度は実施
例６〜９の内層被覆品と同程度のものでおこなった。In addition, the size and hardness of the granular fertilizer used at this time were similar to those of the inner layer coated products of Examples 6 to 9.

。比較例 １０ 実施例１に記載の手段で粒状肥料に ＭｇＮＨ４ＰＯ４・Ｈ２Ｏのみの被覆（被覆比１５．５
．２３％）を施こした被覆肥料を得た。. Comparative Example 10 Granular fertilizer was coated with only MgNH4PO4・H2O (coating ratio 15.5) by the method described in Example 1.
．． 23%) was applied.

以上、実施例１〜９、比較例１〜１０で得られた被覆肥
料者５′？を１００ｍ１の水に浸漬し、３０℃で一定時
間放置後、溶出したアンモニア態窒素量を測定した。As described above, the coated fertilizers 5' obtained in Examples 1 to 9 and Comparative Examples 1 to 10 are as follows. was immersed in 100ml of water and left at 30°C for a certain period of time, and the amount of ammonia nitrogen eluted was measured.

結果を第１〜３図に示した。The results are shown in Figures 1-3.

第１図において曲線ａ、ｂ、ｃはそれぞれ実施例１．２
．３によって得た被覆肥料の１日経過後の溶出アンモニ
ア態窒素量を示すグラフ、曲線ａ’ 、 ｂ／ 、 ｃ
／ばそれぞれ比較例１．２．３のもので１日経過後の溶
出アンモニア態窒素量を示すグラフである。In FIG. 1, curves a, b, and c are respectively of Example 1.2.
．． Graph showing the amount of eluted ammonia nitrogen after one day of the coated fertilizer obtained in step 3, curves a', b/, c
/ is a graph showing the amount of ammonia nitrogen eluted after one day for Comparative Examples 1, 2, and 3, respectively.

同様に第２図では、曲線ａ 、 ａ’はそれぞれ実施例
４と比較例４０１日経過後のもの、曲線ｂ 、 ｂ’は
それぞれ実施例４と比較例４の７日後のもの、同じく曲
線Ｃ９Ｃ′およびｄ、ｄ’はそれぞれ実施例５と比較例
５の１日経過後、７日経過後のものを示す。Similarly, in FIG. 2, curves a and a' are for Example 4 and Comparative Example 401 days after passing, curves b and b' are for Example 4 and Comparative Example 4 after 7 days, respectively, and curve C9C' and d and d' indicate the results of Example 5 and Comparative Example 5 after 1 day and 7 days, respectively.

第３図は１日経過後の溶出率を示し、曲線ａ、ｂ、ｃ、
ｄはそれぞれ実施例６．７．８．９のもの、曲線ａ／ツ
ｂ′、ｃ′、ｄ′はそれぞれ比較例６．７．８．９のも
のを示す。Figure 3 shows the dissolution rate after one day, curves a, b, c,
Curves d and d are those of Example 6.7.8.9, respectively, and curves a/b', c', and d' are those of Comparative Example 6.7.8.9, respectively.

なお比較例１０で得られた被覆肥料の１日後の溶出率は
８５％、７０．２％であった。The dissolution rate of the coated fertilizer obtained in Comparative Example 10 after one day was 85% and 70.2%.

【図面の簡単な説明】[Brief explanation of drawings]

第１図、２図および３図は本発明の実施例ならびに比較
例で得られた被覆肥料の溶出率を表わしたグラフである
。FIGS. 1, 2, and 3 are graphs showing the dissolution rates of coated fertilizers obtained in Examples and Comparative Examples of the present invention.

Claims (1)

【特許請求の範囲】[Claims] １ 粒状肥料の表面に１．リン酸とマグネシウム化合物
およびアンモニアとの反応により生成するリン酸アンモ
ニウムマグネシウムからなる難溶性肥料塩を生成させな
がら被覆し、次いで、その上に１種又は２種以上の有機
資材を被覆することを特徴とする緩効性被覆肥料の製造
方法。1. 1 on the surface of the granular fertilizer. It is characterized by coating while producing a sparsely soluble fertilizer salt consisting of magnesium ammonium phosphate produced by the reaction of phosphoric acid, a magnesium compound, and ammonia, and then coating it with one or more organic materials. A method for producing a slow-release coated fertilizer.