JP3552131B2 - Pest control fumigant composition - Google Patents

Description

【０００９】
（式中、Ｒ_１ およびＲ_２ は同一又は相異なり、水素原子又は炭素数１〜２のアルキル基を表わす。Ｘは酸素原子又は硫黄原子を表わし、Ｙ及びＺは同一又は相異なり、酸素原子、硫黄原子又はメチレン基を表わす。）
（２）前記弱酸性物質が前記有効成分のいずれか一方と等モル以上の量で含有されていることを特徴とする前記（１）記載の害虫防除用燻蒸剤組成物。
（３）前記弱酸性物質がホウ酸またはクエン酸および弱酸性であるその塩であることを特徴とする前記（１）又は（２）項記載の害虫防除用燻蒸剤組成物。
【００１０】
本発明の害虫防除用燻蒸剤組成物とすることにより、オキサジアゾール系化合物と一般式Ｉで表わされるピリジン化合物を混合製剤としたときに生じる化学反応が抑制され、各々が有する作用効果が十分に発揮されるものである。
ここでオキサジアゾール系化合物としては、例えば３−（２−メトキシフェニル）−５−メトキシ−１，３，４−オキサジアゾール−２（３Ｈ）−オン（一般名メトキサジアゾン、商品名エレミック：住友化学工業（株）社製、以下「メトキサジアゾン」という）が代表的には示されるが、この他にも、３−（２−エトキシフェニル）−５−メトキシ−１，３，４−オキサジアゾール−２（３Ｈ）−オン、３−（２−トリフルオロメチルフェニル）−５−トメキシ−１，３，４−オキサジアゾール−２（３Ｈ）−オンなど特開昭５１−１０１９８１号公報に記載の化合物が挙げられる。
また、一般式Ｉで表わされるピリジン化合物としては、例えば２−［１−メチル−２−（４−フェノキシフェノキシ）エトキシ］ピリジン（一般名ピリプロキシフェン、商品名スミラブ：住友化学工業（株）社製、以下「ピリプロキシフェン」という）が代表的には示されるが、この他にも、２−〔２−（４−フェノキシフェノキシ）エトキシ〕ピリジン、（ｓ）−２−〔１−メチル−２−（４−フェノキシフェノキシ）エトキシ〕ピリジン、２−〔２−（４−フェノキシフェノキシ）−１−プロピルオキシ〕ピリジンなど特開昭５９−１９９６７３号公報に記載の化合物が挙げられる。
前記の化合物例は、Ｒ_１ が水素原子、Ｒ_２ がメチル基、Ｘ，Ｙ，Ｚがそれぞれ酸素原子の場合である。
そして、対象となる害虫としては、例えばイエバエ、カ、ゴキブリ、塵性ダニなどの衛生害虫、さらにはアブラムシ、ウンカ、ハダニなどの農業害虫、イガ、コイガなどの衣類害虫が挙げられる。上記の有効成分が防除作用をすることができる害虫であれば、例示された範囲に限定されるものではない。
【００１１】
【発明の実施の形態】
本発明の害虫防除用燻蒸剤組成物に含有する弱酸性物質としては、一般式Ｉで表されるピリジン化合物のオキサジアゾール系化合物に対する作用を抑える物質が使用され、その具体例としては、例えばホウ酸、クエン酸、デヒドロ酢酸、リン酸１ナトリウム、メタリン酸ナトリウムなどが示される。この中でも、ホウ酸およびクエン酸および弱酸性であるこれらの塩などのような弱酸性の化合物、これらの混合物が高い効果を発揮し好ましい。
上記の弱酸性物質は、害虫防除用燻蒸剤に０．１〜２０重量％の範囲の量で含有されるが、有効成分と等モル濃度以上、好ましくは一般式Ｉで表されるピリジン化合物に対して等モル濃度以上の量を含有するように調製する。具体的には、例えば、ピリプロキシフェンを４重量％含有した製剤においては、ホウ酸をほぼ等モル濃度の０．８重量％程度以上、クエン酸では２．４重量％程度以上含有させればよい。
ここでの含有量とは、害虫防除用燻蒸剤の殺虫製剤の重量に対するものを意味し、ピリプロキシフェン４重量％とは、例えば殺虫製剤の全量が１００グラムであるときピリプロキシフェンを４グラムを含有することである。
【００１２】
本発明の害虫防除用燻蒸剤組成物を燻蒸剤として使用するに際しての形態としては、ジェット剤、ロッド剤などの点火方式、加水発熱タイプ、空気酸化発熱タイプなどの化学反応剤方式、電気加熱方式が例示されるが、他の方式のものも使用することができる。
ジェット剤の基剤としては、硝酸塩または亜硝酸塩と熱分解促進剤（例えば、アルカリ土類、金属塩、アルカリ金属塩）の混合物を主基剤とするもの、グアニジン塩と熱分解促進剤（例えば、重クロム酸塩、クロム酸塩）の混合物を主基剤ニトロセルロース系化合物とするものが挙げられる。ロッド剤の基剤としては、燃焼剤（例えば、エチルセルロース、ニトロセルロース）、消炎剤（例えば、メラニン、小麦でん粉）、増量剤（例えば、珪藻土）および賦形剤の混合物を主基剤とするものが挙げられる。
【００１３】
加水発熱タイプの基剤としては、蒸散補助剤と発熱物質との併用を主基剤とするものが挙げられる。
蒸散補助剤としては、熱分解して主として窒素ガスを発生する通常の各種有機発泡剤がいずれも使用できるが、好ましくは３００℃以下の発泡温度を有するものがよい。代表的な有機発泡剤を下記第１表に例示する。
【００１４】
【表１】

【００１５】
上記有機発泡剤は、これらに通常添加されるＣｄ−ステアレート、Ｃａ−ステアレート、Ｚｎ−ステアレート、Ｚｎ−オクテート、ＺｎＯ、Ｓｎ−マレート、ＺｎＣＯ_３ 、尿素、クロムエロー、カーボンブラック等の添加剤を併用して発泡温度を低下させることが可能である。
本発明において上記発泡剤の害虫防除剤に対する混合割合は、得られる防除剤のいわゆる防除効力等に対し発泡剤を１／２重量倍程度以上とするのがよい。発泡剤の混合割合の増大に伴い次第に害虫防除剤の有効揮散率は向上するがあまり多くなっても効果は向上しない。通常害虫防除剤に対し発泡剤を１／２〜１００重量倍程度とするのがよい。また上記害虫防除剤及び発泡剤の混合形態は特に制限されないが、作業性及び得られる駆除剤の製造及び使用の簡便性を考慮すると、適当な顆粒状、塊状、ペレット状、ペースト状、タブレット状としたり、またこれらの剤型のものを各種コーティング剤でコーティング、熱溶融性樹脂袋等に封入することが好ましく、これら各使用形態に応じて各種バインダー、溶剤等を使用できる。
【００１６】
発熱物質としては、酸化カルシウム、塩化マグネシウム、塩化アルミニウム、塩化カルシウム、塩化鉄等水を添加するのみで発熱反応する物質を例示できる。この発熱物質を熱源とし、上記害虫防除剤及び発泡剤、更に必要に応じて適当な添加剤を混合してなる各種形態の混合物を間接的に加熱して上記混合物を燃焼させることなく該混合物中の発泡剤を熱分解させる。
空気酸化発熱タイプの基剤としては、上記有機発泡剤からなる蒸散補助剤と酸化反応により発熱する金属もしくは金属化合物、アルカリ金属の硫化物、多硫化物、水硫化物または含水塩などの発熱剤、酸化剤、触媒物質（例えばカーボンブラック、活性炭、木炭、コークス、アスファルト）及び充填剤（例えば、天然繊維、合成繊維、合成樹脂発泡体）の併用を主基剤とするものが挙げられる。
酸化反応により発熱する金属もしくは金属化合物を利用するものとしては、鉄粉と塩素酸アンモニウム等の酸化剤の混合物、鉄と硫酸カリウム、硫化鉄、金属塩化物、硫酸鉄等の１種を水及び酸素と接触させる等の方式を例示できる。
金属硫化物の酸化反応を利用するものとして、硫化ソーダと炭化鉄との混合物を酸素と接触させる等の方式を例示できる。
【００１７】
また、上記害虫防除剤及び発泡剤更に必要に応じ適当な添加剤を混合してなる各種形態の混合物中の発泡剤を熱分解させる熱源として、通電により発熱する電気的熱源も使用できる。例えば、フェロクロム線、ニクロム線、正特性サーミスタ（ＰＣＴ）、シート状ヒーター、半導体を利用するヒーター等を例示できる。
これらの中でも、化学反応剤方式、電気加熱方式、加水発熱タイプのものがマッチや点火具による火炎を用いることがなく、安全性の点から好ましい。
加水発熱タイプ、空気酸化発熱タイプ、通電発熱タイプはいずれも上記燻蒸用薬剤成分を間接的に加熱する。間接加熱は例えば上記燻蒸用薬剤成分を適当な容器に収容し、該容器と熱源を組み合わせことにより行われる。より好ましくは熱源の熱量を有効利用するために熱源を密閉型外容器内に収容し、該外容器に燻蒸用薬剤成分を収容した内容器を、その底壁及び側壁の少なくとも１部を隔壁として収納するのがよい。
化学反応剤方式、電気加熱方式はいずれも上記密閉型外容器内に収納するのがよい。
【００１８】
本発明の害虫防除用燻蒸剤においては、本発明の目的とする効果、有効成分の揮散や拡散などが妨げられないのであれば、香料や殺菌剤など他の成分を適宜配合することに何ら制限はない。
例えば、前記の薬剤には、通常用いられている効力増強剤、揮散率向上剤、消臭剤等の各種添加剤を任意に添加することができる。効力増強剤には、ピペロニルブトキサイド、Ｎ−プロピルイゾーム、ＭＧＫ−２６４、サイネピリン２２２、サイネピリン５００、リーセン３８４、ＩＢＴＡ、Ｓ−４２１等が、揮散率向上剤としてはフエネチルイソチオシアネート、ハイミックス酸ジメチル等が、消臭剤としてはラウリル酸メタクリレート（ＬＭＡ）等が、また香料としてはシトラール、シトロネラール等がそれぞれ例示できる。
【００１９】
本発明者らの検討によれば、化学反応によって分解される成分はオキサジアゾール系化合物が主であり、詳細は明らかではないが、一般式Ｉで表されるピリジン化合物のピリジン環がオキサジアゾール系化合物のメトキシ基に影響しているものと思われる。そのため本発明では害虫防除剤を調製するときに、例えばオキサジアゾール系化合物がメトキサジアゾン、一般式Ｉで表されるピリジン化合物がピリプロキシフェンである場合では、同時練り込みした顆粒製剤とした場合は、一緒に上記の弱酸性物質を含有させればよい。また、メトキサジアゾンとピリプロキシフェンを別顆粒製剤としたときには安定性はより優れたものとなり、それぞれに上記の弱酸性物質を配合するか、もしくは一方に含有することで効果を得ることができる。この時、メトキサジアゾンと共に弱酸性物質を配合することが好ましい。そして配合濃度はピリプロキシフェンとほぼ等モル濃度以上とすることがより好ましい。
【００２０】
【実施例】
以下に実施例により本発明を具体的に説明する。ただし、本発明はこの実施例のみに限定されるものではない。
ａ．顆粒製剤の調製
ａ−１．同時練り込み顆粒製剤
蒸散補助剤（アゾジカルボンアミド）１０グラムにオキサジアゾール系化合物（メトキサジアゾン）１６重量％と一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）４重量％を含有させ同時練り込み顆粒製剤を調製した。
ａ−２．別練り込み顆粒製剤
蒸散補助剤（アゾジカルボンアミド）８グラムにオキサジアゾール系化合物（メトキサジアゾン）２０重量％を含有させた練り込み顆粒とアゾジカルボンアミド２グラムに一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）２０重量％を含有させた練り込み顆粒を均一に混合し別練り込み顆粒製剤を調製した。
【００２１】
ｂ．弱酸性物質の選択
ｂ−１．方法
上記の２種類の練り込み顆粒製剤をそれぞれガラスのバイアル瓶に入れ、６０℃の温度条件に放置した。その２週間後に顆粒製剤を取り出し、アセトンで顆粒製剤中のオキサジアゾール系化合物（メトキサジアゾン）および一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）を抽出した。そして、内部標準物質を加えガスクロマトグラフ分析により、それぞれの残存率を測定した。なお弱酸性物質として第２表記載の物質を一緒に含有させた。
なお、別練り込み顆粒製剤の場合は、弱酸性物質をオキサジアゾール系化合物（メトキサジアゾン）顆粒に入れた。また、弱酸性物質の添加割合（重量％）はオキサジアゾール系化合物（メトキサジアゾン）顆粒に対する値である。
【００２２】
【表２】

【００２３】
ｂ−２．結果
弱酸性物質であるホウ酸およびクエン酸を含有させた場合、特にオキサジアゾール系化合物（メトキサジアゾン）の残存率が著しく高く、維持されていることがわかる。
ｃ．残存率確認試験
ｃ−１．方法
上記の２種類の練り込み顆粒製剤にホウ酸をいっしょに含有させた時、その濃度と有効成分の残存率（６０℃、２週間放置後）をｂ−１．に記載の方法と同様に測定した。結果は図１〜２に示した。図１〜２において、横軸にホウ酸の添加濃度（％）を示し、縦軸に有効成分の初期含有量に対する残存量の割合（％）を示す。図１は、同時練り込み顆粒製剤を使用した場合であり、図２は、別練り込み顆粒製剤を使用した場合である。
ｃ−２．結果
ホウ酸の含有濃度の増加に伴い、オキサジアゾール系化合物（メトキサジアゾン）の残存率は増加し、一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）含量とほぼ等モル濃度において最高値に達した。これ以上の濃度ではほぼ平衡であった。またクエン酸においても同様の結果を得た。
【００２４】
ｄ．経時残存率試験
ｄ−１．方法
上記ａ−１．記載の同時練り込み顆粒製剤にホウ酸１重量％を一緒に含有させた時の有効成分の経時的な残存率をｂ−１．に記載の方法と同様に測定した。ただし、温度は５０℃に放置し、放置期間は３ヶ月とした。結果は図３に示した。図３において、横軸に保存期間を示し、縦軸に有効成分の初期含有量に対する残存量の割合（％）を示す。
ｄ−２．結果
ホウ酸１重量％を含有させることで、有効成分の残存率は高められ、特にオキサジアゾール系化合物（メトキサジアゾン）においては顕著であった。
【００２５】
【発明の効果】
本発明の害虫防除用燻蒸剤組成物は、弱酸性物質を含有することでオキサジアゾール系化合物（メトキサジアゾン）と一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）とが化学反応により分解されるの抑制し、上記有効成分の優れた安定性を得ることができる。そして有効成分と等モル濃度以上、特に一般式Ｉで表されるピリジン化合物（ピリプロキシフェン）と等モル濃度以上の弱酸性物質を含有することが好ましい。
【図面の簡単な説明】
【図１】本発明の実施例における同時練り込み顆粒を使用した場合の、ホウ酸の添加濃度に対する有効成分の残存率の関係を表したグラフを示す。
【図２】本発明の実施例における別練り込み顆粒を使用した場合の、ホウ酸の添加濃度に対する有効成分の残存率の関係を表したグラフを示す。
【図３】本発明の実施例における同時練り込み顆粒を使用した場合の、ホウ酸の添加濃度に対する有効成分の経時的な残存率の関係を表したグラフを示す。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fumigant composition for controlling insect pests, and in particular to a fumigating composition for controlling insect pests which has provided an excellent stability with respect to a fumigant for controlling insect pests containing the above-mentioned active ingredient, which has been considered to have a problem in stability. About.
[0002]
[Prior art]
Conventionally, as a method of exterminating insect pests by fumigation of a pesticidal agent in a short time, a method using a so-called fumigation agent, in which the agent is mixed with a burning agent to emit the agent by burning and burning of the burning agent, is generally used. However, this method has the drawback that the burning of a combustible that generates highly toxic smoke is indispensable, so that it is accompanied by the irritating odor due to smoking, the danger to the human body and the danger of fire. In order to solve the problem, the insecticide is mixed with azodicarbonamide, the mixture is heated indirectly to thermally decompose the azodicarbonamide without burning, and the insecticide is effectively fumigated by the action of the pyrolysis gas. A method for controlling pests (Japanese Patent Publication No. 52-28842) has been proposed.
[0003]
As a drug used in such a method of controlling pests, in addition to pyrethroid insecticides, various kinds of insecticides and other agents are known.In recent years, certain cockroaches are classified into the pyrethroid insecticides. As a drug having an effective insecticidal action against such cockroaches as having become resistant to such cockroaches, 3- (2-methoxyphenyl) -5-methoxy-1,3,4-oxacin A compound in which diazol-2 (3H) -one is mixed with a pyrethroid insecticide compound and further mixed with an insect juvenile hormone-like compound has been proposed (Japanese Patent Application Laid-Open No. 1-172307).
[0004]
The above-mentioned 3- (2-methoxyphenyl) -5-methoxy-1,3,4-oxadiazol-2 (3H) -one is one of the oxadiazole-based compounds and has an excellent pest control effect. (D. Ambrosi et al (1979): Proc. Brit. Prot. Conf, Pests and Diseases, p. 533). The use of this drug as a fumigant in pyrethroid resistance countermeasures has attracted attention, but its stability, particularly heat stability, is poor, so that a stabilizer must be used in combination. As a result of investigations, it was found that a phenolic compound and / or sorbitan monooleate as a stabilizer or piperonyl butoxide containing these compounds can be used as a heating fumigant (Japanese Patent Publication No. 11523/1992). ) And stabilization using a phosphite-based stabilizer (Sumitomo Chemical (1988), pp. 37-45), and the technology is disclosed.
[0005]
As a result of various studies, the product was commercialized as a fumigant.However, in order to further enhance the control effect and broaden the spectrum, mixed preparations with other control components were being studied. It was found that decomposition which might be caused by the reaction occurred. In particular, the mechanism of action is a kind of insect juvenile hormone-like compound that has recently attracted attention, and there is a problem that considerable decomposition occurs when used in combination with the pyridine compound represented by the general formula I.
[0006]
[Problems to be solved by the invention]
An oxadiazole-based compound, 3- (2-methoxyphenyl) -5-methoxy-1,3,4-oxadiazol-2 (3H) -one, and a pyridine compound represented by the general formula I, 2- The effect of the combined use with [1-methyl-2- (4-phenoxyphenoxy) ethoxy] pyridine is a remarkable growth inhibitory effect on pests as described in JP-A-1-172307. However, in the case of a fumigant, which is one of the forms of application of the drug, decomposition occurs between the two and a sufficient effect cannot be obtained. In particular, 3- (2-methoxyphenyl) -5-methoxy-1,3,4 Degradation is significant in -oxadiazol-2 (3H) -one, and the solution is not yet known.
An object of the present invention is to solve the above-mentioned problems and to provide a pest control fumigant composition having excellent stability.
[0007]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that by containing a weakly acidic substance with respect to the pest controlling fumigant composition containing the active ingredient, it is possible to significantly enhance the stability thereof, and reached the present invention. .
That is, the present invention is achieved by the following pest control fumigant composition.
(1) A fumigant composition for controlling insect pests, comprising an oxadiazole compound as an active ingredient and a pyridine compound represented by the general formula I, and containing a weakly acidic substance.
[0008]
Embedded image

[0009]
(Wherein R ₁ and R ₂ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. X represents an oxygen atom or a sulfur atom; Y and Z are the same or different; an oxygen atom , A sulfur atom or a methylene group.)
(2) The fumigant composition for controlling insect pests according to (1), wherein the weakly acidic substance is contained in an amount equal to or more than one mole of any one of the active ingredients.
(3) The fumigant composition for controlling insect pests according to the above (1) or (2), wherein the weakly acidic substance is boric acid or citric acid and a weakly acidic salt thereof.
[0010]
By using the pest controlling fumigant composition of the present invention, the chemical reaction that occurs when a mixed preparation of an oxadiazole compound and a pyridine compound represented by the general formula I is suppressed, and the action and effect possessed by each are sufficient. It is exhibited in.
Here, as the oxadiazole-based compound, for example, 3- (2-methoxyphenyl) -5-methoxy-1,3,4-oxadiazol-2 (3H) -one (methoxadiazone, common name; trade name: Elemic: Sumitomo) Representatively, “methoxadiazon” manufactured by Chemical Industry Co., Ltd.) is also shown, but in addition, 3- (2-ethoxyphenyl) -5-methoxy-1,3,4-oxadiazole -2 (3H) -one, 3- (2-trifluoromethylphenyl) -5-tomexi-1,3,4-oxadiazol-2 (3H) -one and the like are described in JP-A-51-101981. The compound of.
Examples of the pyridine compound represented by the general formula I include 2- [1-methyl-2- (4-phenoxyphenoxy) ethoxy] pyridine (generic name: pyriproxyfen, trade name: Sumilab: Sumitomo Chemical Co., Ltd.) , Hereinafter referred to as “pyriproxifene”), but also 2- [2- (4-phenoxyphenoxy) ethoxy] pyridine, (s) -2- [1-methyl- Compounds described in JP-A-59-199673, such as 2- (4-phenoxyphenoxy) ethoxy] pyridine and 2- [2- (4-phenoxyphenoxy) -1-propyloxy] pyridine, are exemplified.
In the above compound examples, R ₁ is a hydrogen atom, R ₂ is a methyl group, and X, Y, and Z are each an oxygen atom.
Examples of the target pests include, for example, sanitary pests such as house flies, mosquitoes, cockroaches, dust mites, agricultural pests such as aphids, planthoppers, spider mites, and clothing pests such as iga and koiga. It is not limited to the illustrated range as long as the above-mentioned active ingredient is a pest capable of controlling pests.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
As the weakly acidic substance contained in the pest controlling fumigant composition of the present invention, a substance that suppresses the action of a pyridine compound represented by the general formula I on an oxadiazole-based compound is used. Boric acid, citric acid, dehydroacetic acid, monosodium phosphate, sodium metaphosphate and the like are shown. Among these, weakly acidic compounds such as boric acid, citric acid, and weakly acidic salts thereof, and mixtures thereof are preferable because they exhibit high effects.
The weakly acidic substance is contained in the fumigant for controlling insect pests in an amount in the range of 0.1 to 20% by weight. It is prepared so as to contain an equimolar concentration or more. Specifically, for example, in a preparation containing 4% by weight of pyriproxyfen, boric acid may be contained in an approximately equimolar concentration of about 0.8% by weight or more, and citric acid may be contained in an amount of about 2.4% by weight or more. Good.
The content here means the weight of the insecticidal preparation of the fumigant for controlling insect pests, and 4% by weight of pyriproxyfen is, for example, 4 g of pyriproxyfen when the total amount of the insecticide preparation is 100 g. Is contained.
[0012]
Examples of the mode of using the pest controlling fumigant composition of the present invention as a fumigant include a jetting agent, an ignition system such as a rod agent, a hydrothermally heating type, a chemical reactant system such as an air oxidation heating type, and an electric heating system. However, other types can also be used.
As a base of the jetting agent, a mixture mainly composed of a nitrate or a nitrite and a thermal decomposition accelerator (for example, alkaline earth, metal salt, alkali metal salt), a guanidine salt and a thermal decomposition accelerator (for example, , A dichromate, a chromate) as a main base nitrocellulose compound. The base of the rod agent is based on a mixture of a burning agent (eg, ethyl cellulose, nitrocellulose), an anti-inflammatory agent (eg, melanin, wheat starch), a bulking agent (eg, diatomaceous earth) and an excipient. Is mentioned.
[0013]
Examples of the hydrothermally exothermic type base include those whose main base is a combination of a transpiration aid and an exothermic substance.
As the transpiration aid, any of various ordinary organic foaming agents that mainly generate nitrogen gas by thermal decomposition can be used, but those having a foaming temperature of 300 ° C. or lower are preferable. Representative organic blowing agents are illustrated in Table 1 below.
[0014]
[Table 1]

[0015]
The organic blowing agents include, but usually added as Cd- stearate, Ca-stearate, Zn- stearate, Zn- octoate, ZnO, Sn- malate, ZnCO _3, urea, chrome yellow, additives such as carbon black Can be used together to lower the foaming temperature.
In the present invention, the mixing ratio of the foaming agent to the insect-controlling agent is preferably about 1/2 or more times the weight of the foaming agent with respect to the so-called controlling effect of the obtained controlling agent. As the mixing ratio of the blowing agent increases, the effective volatilization rate of the pesticidal agent gradually increases, but the effect does not improve even if it is too large. Usually, the foaming agent is preferably used in an amount of about 1/2 to 100 times the weight of the pesticide. The form of the mixture of the insecticide and the blowing agent is not particularly limited. However, considering the workability and the simplicity of production and use of the obtained pesticide, appropriate granules, lumps, pellets, pastes, tablets, etc. It is also preferable that these dosage forms are coated with various coating agents and sealed in a hot-melt resin bag or the like, and various binders, solvents and the like can be used according to the respective usage forms.
[0016]
Examples of the exothermic substance include substances that exothermicly react only by adding water, such as calcium oxide, magnesium chloride, aluminum chloride, calcium chloride, and iron chloride. Using this exothermic substance as a heat source, the mixture of various forms obtained by mixing the above-mentioned pest control agent and foaming agent, and further, if necessary, an appropriate additive is heated indirectly in the mixture without burning the mixture. Is thermally decomposed.
Examples of the air-oxidation heat-generating base include a heat-generating agent such as a metal or metal compound, an alkali metal sulfide, a polysulfide, a hydrosulfide, or a hydrous salt, which generates heat by an oxidation reaction with the evaporation aid composed of the organic foaming agent. , An oxidizing agent, a catalyst substance (eg, carbon black, activated carbon, charcoal, coke, asphalt) and a filler (eg, natural fiber, synthetic fiber, synthetic resin foam) as a main base.
As a material utilizing a metal or a metal compound which generates heat by an oxidation reaction, a mixture of iron powder and an oxidizing agent such as ammonium chlorate, iron and potassium sulfate, iron sulfide, metal chloride, and one kind of iron sulfate such as water and Examples of the method include contact with oxygen.
As a method utilizing the oxidation reaction of metal sulfide, a method of bringing a mixture of sodium sulfide and iron carbide into contact with oxygen can be exemplified.
[0017]
Further, as a heat source for thermally decomposing the foaming agent in the various forms of the mixture obtained by mixing the above-mentioned pest control agent and foaming agent and, if necessary, an appropriate additive, an electric heat source which generates heat by energization can also be used. For example, a ferrochrome wire, a nichrome wire, a positive temperature coefficient thermistor (PCT), a sheet heater, a heater using a semiconductor, and the like can be exemplified.
Among them, the chemical reactant method, the electric heating method, and the water-heating type are preferable from the viewpoint of safety because they do not use a flame due to a match or an igniter.
The hydrothermal heating type, the air oxidation heating type, and the energization heating type all indirectly heat the fumigation drug component. Indirect heating is performed, for example, by containing the fumigation drug component in a suitable container and combining the container with a heat source. More preferably, the heat source is housed in a closed outer container in order to effectively use the calorie of the heat source, and the inner container containing the fumigation drug component in the outer container has at least a part of the bottom wall and the side wall as a partition. It is good to store.
Both the chemical reactant method and the electric heating method are preferably housed in the closed outer container.
[0018]
In the fumigant for controlling insect pests of the present invention, as long as the effects aimed at by the present invention and the volatilization and diffusion of the active ingredient are not hindered, there is no restriction on appropriately mixing other components such as fragrances and fungicides. There is no.
For example, various additives such as an efficacy enhancer, a volatilization rate improver, a deodorant and the like which are usually used can be arbitrarily added to the above-mentioned drug. Examples of the potency enhancer include piperonyl butoxide, N-propylisosome, MGK-264, sinepiline 222, sinepiline 500, Risen 384, IBTA, S-421, and the like. And dimethyl hymixate, methacrylate (LMA) as a deodorant, and citral and citronellal as fragrances.
[0019]
According to the study of the present inventors, the components decomposed by the chemical reaction are mainly oxadiazole-based compounds, and details thereof are not clear, but the pyridine ring of the pyridine compound represented by the general formula I has an oxadiazole compound. It is thought that it affects the methoxy group of the azole compound. Therefore, when preparing a pest control agent in the present invention, for example, when the oxadiazole-based compound is methoxadiazone, and the pyridine compound represented by the general formula I is pyriproxyfen, when the granulated preparation is simultaneously kneaded, The above-mentioned weakly acidic substance may be contained together. Further, when methoxadiazone and pyriproxyfen are prepared as separate granules, the stability becomes more excellent, and the effect can be obtained by blending the above-mentioned weakly acidic substances or containing them in one of them. At this time, it is preferable to mix a weakly acidic substance together with methoxadiazone. And it is more preferable that the compounding concentration is substantially equal to or higher than that of pyriproxyfen.
[0020]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited to only this embodiment.
a. Preparation of granule preparation a-1. Simultaneous kneading granule preparation 10 g of an evaporation aid (azodicarbonamide) contains 16% by weight of an oxadiazole compound (methoxadiazone) and 4% by weight of a pyridine compound (pyriproxifene) represented by the general formula I and is simultaneously kneaded. A granulated preparation was prepared.
a-2. Separately kneaded granule preparation A kneaded granule comprising 8 g of an oxadiazole-based compound (methoxadiazon) in 8 g of an evaporation aid (azodicarbonamide) and a pyridine compound represented by the general formula I in 2 g of azodicarbonamide (Pyriproxyfen) The kneaded granules containing 20% by weight were uniformly mixed to prepare a separately kneaded granule preparation.
[0021]
b. Selection of weakly acidic substance b-1. Method The above two types of kneaded granule preparations were each placed in a glass vial and allowed to stand at a temperature of 60 ° C. Two weeks later, the granule preparation was taken out, and the oxadiazole-based compound (methoxadiazone) and the pyridine compound (pyriproxyfen) represented by the general formula I in the granule preparation were extracted with acetone. Then, an internal standard substance was added thereto, and the residual ratio of each was measured by gas chromatography analysis. The substances listed in Table 2 were also included as weakly acidic substances.
In the case of a separately kneaded granule preparation, a weakly acidic substance was added to oxadiazole-based compound (methoxadiazone) granules. The addition ratio (% by weight) of the weakly acidic substance is a value based on oxadiazole-based compound (methoxadiazone) granules.
[0022]
[Table 2]

[0023]
b-2. As a result, when boric acid and citric acid, which are weakly acidic substances, were contained, the residual ratio of the oxadiazole-based compound (methoxadiazone) was particularly high and maintained.
c. Residual rate confirmation test c-1. Method When boric acid was added to the above two kinds of kneaded granule preparations, the concentration and the residual ratio of the active ingredient (after standing at 60 ° C. for 2 weeks) were determined as b-1. The measurement was performed in the same manner as described in the above section. The results are shown in FIGS. 1 and 2, the horizontal axis shows the concentration of boric acid added (%), and the vertical axis shows the ratio (%) of the residual amount to the initial content of the active ingredient. FIG. 1 shows a case where a simultaneously kneaded granule preparation is used, and FIG. 2 shows a case where a separately kneaded granule preparation is used.
c-2. Results With the increase in the concentration of boric acid, the residual ratio of the oxadiazole-based compound (methoxadiazone) increased, and reached the highest value at almost equimolar concentration with the pyridine compound (pyriproxifene) represented by the general formula I. Reached. At concentrations higher than this, there was almost equilibrium. Similar results were obtained with citric acid.
[0024]
d. Time-lapse residual rate test d-1. Method above a-1. The residual ratio of the active ingredient over time when 1% by weight of boric acid was added to the simultaneously kneaded granule preparation described in b-1. The measurement was performed in the same manner as described in the above section. However, the temperature was left at 50 ° C., and the leaving period was 3 months. The results are shown in FIG. In FIG. 3, the abscissa indicates the storage period, and the ordinate indicates the ratio (%) of the residual amount to the initial content of the active ingredient.
d-2. Results By containing boric acid at 1% by weight, the residual ratio of the active ingredient was increased, and in particular, the oxadiazole-based compound (methoxadiazone) was remarkable.
[0025]
【The invention's effect】
The fumigant composition for controlling insect pests of the present invention contains a weakly acidic substance, whereby an oxadiazole compound (methoxadiazone) and a pyridine compound (pyriproxifene) represented by the general formula I are decomposed by a chemical reaction. And the excellent stability of the active ingredient can be obtained. Further, it is preferable to contain a weak acidic substance having an equimolar concentration or more, particularly an equimolar concentration or more with the pyridine compound (pyriproxifene) represented by the general formula I.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the concentration of boric acid added and the residual ratio of an active ingredient in the case of using the simultaneously kneaded granules in Examples of the present invention.
FIG. 2 is a graph showing the relationship between the concentration of boric acid added and the residual ratio of the active ingredient when separately kneaded granules are used in the examples of the present invention.
FIG. 3 is a graph showing the relationship between the concentration of boric acid added and the residual ratio of the active ingredient over time when the simultaneously kneaded granules in the examples of the present invention are used.

Claims (3)

A fumigant composition for controlling insect pests, comprising an oxadiazole-based compound and a pyridine compound represented by the general formula I as active ingredients, and a weakly acidic substance.

(Wherein R ₁ and R ₂ are the same or different and represent a hydrogen atom or an alkyl group having 1 to 2 carbon atoms. X represents an oxygen atom or a sulfur atom; Y and Z are the same or different; an oxygen atom , A sulfur atom or a methylene group.) The fumigant composition for controlling pests according to claim 1, wherein the weakly acidic substance is contained in an amount equal to or more than one mole of one of the active ingredients. The fumigant composition for controlling pests according to claim 1 or 2, wherein the weakly acidic substance is boric acid or citric acid and a salt thereof which is weakly acidic.

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