CA1100099A - Fumigating method and apparatus - Google Patents

Abstract

A B S T R A C T

The invention provides a fumigating method comprising heating a mixture of an active ingredient and a blowing agent indirectly with a heating element to thermally decompose the blowing agent without entailing combustion and to volatilize the active ingredient.

Description

This invention relatestoamethod of fumigating the interior of rooms and other confined spaces for controlling vermin and for fungicidal and incensing purposes, and an apparatus therefor, and more particularly to fumi-gating method and apparatus which are capable of concent-rically producing such effects within a short period of time e.g.a few minutes or ten-odd minutes. The present method and apparatus are especially useful for controlling noxious insects, such as mosquitoes, flies and ~ockroaches, which are detrimental to man and also other insects, such as plant lice, green house whiteflies and caterpillers, which are harmful to agricultural plants.
As a method of controlling noxious insects, fumigation is known in which compositions of an active chemical and a combustible material are used, such that the combustible material, when burned, gives off heat and smoke,the heat causing the active ingredient to concentrically vaporize within a short time and the smoke assisting the volatilization of the ingredient. In order to quickly volatilize a great amount of active ingredient, the combus-tible materials useful for fumigating compositions are those capable of evolving a large quantity of smoke. The large quantity of smoke emitted by such combustible material generally has a pungent odor and high toxicity is harmful to the human body and might possibly be mistaken for a fire.

Q9~

Soot and the like contained in the smoke tend to soil household furniture and walls in rooms. The combustible material involves a fire hazard. Fumigators must therefore be handled with care. The known fumigators further have the serious drawback that the heat of combustion of the combustible material decomposes part of the active ingredient and results in a loss of the active ingredient, consequently affording a lower volatilization efficiency,namely lower effective fugacity rate and reduced efficacy. Measurements in the above method using various insecticides lead to effective fugacity rates lower than.10~. Thus the fumigators heretofore known are not usable with safety and convenience and are unsatisfactory in effectiveness.
An object of this invention is to provide a fumigating method which can be practiced with high safety substantially free of attendant smoke and without involving combustion and an apparatus therefor.
Another object of this invention is to provide a fumigating method and an apparatus therefor capable of effectively quickly giving off the vapor of an active ingredient without entailing a loss of the active ingredient due to the thermal decomposition ther of.
Still another object of this invention is to provide a fumigating method and an apparatus therefor capable of giving off the vapor of an active ingredient uniformly throughout a confined space within a short period of time to produce greatly improved insect-controlling effects.

These and other objects of this invention will become apparent from the following description.
This invention provides a fumigating method comprising heating a mixture of an active ingredient and a blowing agent indirectly with a heating element to ther-mally decompose the blowing agent without entailing combus-tion and to volatilize the active ingredient.
Further this invention provides a fumigating apparatus for practicing the method of this invention com-prising a container which has at least one compartment accomodating a mixture of an active ingredient and a blowing agent and at least one further compartment provided ad~acent to said compartment and accommodating a heating element, the interior of the container being divided with a partition into said compartments, the partition providing a surface for transferring the heat evolved from said heating element to the mixture.
Throughout the specification and claims, the term "indirect heating" refers to heating of a mixture of an active ingredient and a blowing agent with the heat given off from a heating element through a heat transfer surface or a partition provided in a container.
We have found that when a mixture of an active ingredient and a blowing agent is heated with a heating element indirectly to thermally decompose the blowing agent to a gas, the active ingredient can be vol~tilized with a greatly improved efficiency substantially free o thermal decomposition.

ilOOQ99 According to the fumigating method of this invention, a large quantity of the vapor of an active ingredient can be emitted and diffuse~i through a confined space without involving combustion or producing smoke which would have a pungent odor and toxicity and without involving any loss of the active ingredient due to the thermal decom-position.
The active ingredient useful in this invention are various and include those heretofore used for insecticidal, fugicidal and incensing purposes. Typical of useful examples are as follows.
1. Insecticide (1) 3-allyl-2-methylcyclopenta-2~ene-4-one-1-yl dl-cis/
trans-chrysanthemate(available under the trademark "Pynamin", product of SUMITOMO CHEMICAL CO.,LTD.,Japan, hereinafter referred to as "allethrin A");

(2) 3-allyl-2-methylcyclopenta-2-ene-4-one-1-yl d-cis/
trans-chrysanthemate (available under the trademark "Pynamin-forte", product of SUMITOMO CHEMICAL CO.,LTD., Japan, hereinafter referred to as "allethrin B");

(3) d-3-allyl-2-methylcyclopenta-2-ene-4-one-1 yl d-trans-chrysanthemate(available under the trademark "Exlin", product of SUMITOMO CHEMICAL CO.,LTD.,Japan);

(4) 3-allyl-2-methylcyclopenta-2-ene-4-one-1-yl d-trans-chrysanthemate ;

(5) N-(3,4,5,6-tetrahydrophtha]imide)-methyl dl-cis/trans-chrysanthemate(available under the trademark "Neo-pynamin", product of SUMITOMO CHEMICAL CO.,LTD.,Japan, hereinafter referred to as "phthalthrin");

(6) 5-benzyl-3-rurylmethyl d-cis~trans-chrysanthemate (available under the trademark "Chrysron-forte", product of SUMITOMO CHEMICAL CO., LTD.,Japan, hereinafter referred to as "resmethrin") ;

(7) 5-propargyl-3-furylmethyl chrysanthemate ;

(8) 3-phenoxybenzyl-2,2-dimethyl-3-(2', 2'-dichloro) vinylcyclopropane-carboxylate (available under the trademark "Eksmin", product of SUMITOMO CHEMICAL CO., LTD.,Japan, hereinafter referred to as "permethrin");

(9) 3-phenoxybenzyl d-cis/trans-chrysanthemate (available under the tradem~rk "Sumithrin", product of SUMITOMO
CHEMICAL CO., LTD., Japan, hereinafter referred to as "phenothrin");

(10) 0,0-dimethyl 0-~2,2-dichloro) vinylphosphate (hereinafter referred to as "DDVP") ;

(11) o-isopropoxyphenyl methylcarbamate ;

(12) 0,0-dimethyl 0-(3-methyl-4-nitrophenyl)phosphorothioate;

(13) 0,0-diethyl 0-2-isopropyl-4-methyl-pyrimidyl-(6)-thio-phosphate ;

(14) 0,0-dimethyl S-(1,2-dicarboethoxyethyl)-dithiopho~;phate;
Among those insecticides,allethrin ~allethrin B, phthalthrin, resmethrin, permethrin, phenothrin and DDVP are most preferable.
2. Industrial fungicide (1) 2,4,4'-tr~chloro-2'-hydroxydiphenyl ether (hereinafter referred to as "IF-l");
(2) 2,3,5,6-tetrachloro-4-(methylsulfonyl)-pyridine (hereinafter referred to as "IF-2") ;

(3) alkylbenzyl dimethylammonium chloride (to be referred to as "IF-3") ;
(4) benzyldimethyl ~2-[2-(p-1,1,3,3-tetramethyl-butylphenoxy) ethoxy] ethyl} ammonium chloride (to be referred to as "IF-4") ;
(5) N,N-dimethyl-N-phenyl-N'-(fluorodichloro methylthio) sulfonamide (hereinafter referred to as "IF-5") ;
(6) 2-(4'-thiazolyl3benzimidazole (hereinafter referred to as"IF-6") ;
0 (7) N-(fluorodichloromethylthio)-phthalimide (hereinafter referred to as "IF-7") ;
(8) 6-acetoxy-2,4-dimethyl-m-dioxine (hereinafter referred to as "IF-8");
(9) salicylic acid ;
(10) formalin ;
(11) 4-isopropyltropolone ;
(12) p-chloro-m-xylenol ;
(13) zinc bis (2-pyridinethiol-1-oxide);
(14) sodium-2-pyridinethiol-1-oxide ;

(15) diiodo methyl-p-tolyl-sulfone ;

(16) p-chlorophenyl-diiodomethyl sulfone ;

(17) 2,4-hexadienoic acid ;

(18) N-trichloromethylthio-4-cyclohexene-1,2-di.carboximide;
~19) 2,4,5,6-tetrachloro-isophthalonitrile ;
(20) butyl-p-hydroxybenzoate;

llOl~lQ99 (21) 3-trifluoromethyl-4,4'-dichlorocarbanilide ;
(22) 2,2'-methylenebis[3,4,6-trichlorophenol];
(23) 2-hydroxyethyl-disulfide ;
(24) ~-phenoxyethylalcohol ;
(25) 1,3-benzenediol ;
(26) 1-dodecyl-2-methyl-3-benzyl-imidazolium chloride ;
(27) alkyl-diaminoethylene glucine HCQ ;
(28) polymeric biguanide HCQ ;
(29) polyoctyl polyamino ethylglycine ;
(30) hexahydro-1,3,5-tris-(2-hydroxyethyl)-S-triazine ;
(31) polyhexamethylene b;guanide HCQ ;
(32) poly [oxyethylene (dimethylimino) ethylene dichloride];
(33)alkylbetaine type S.A.A.;
(34) bis-(p-chlorophenyldiguanide)-hexanegluconate ;
(35) S-bromo-S-nitro-1,3-dioxane ;
(36) A mixture of 1,2-benzoisothiazoline-3-one, quartenary ammonium salt and propylene glycol ;
(37) allcyldi-(aminoethyl)glycine;
(38) alkylisoquinolinium bromide ;
(39) 3,4,4'-trichlorocarbanilide ;
(40) decamethylene-bis-(4-aminoquinaldinium chloride);
(41) sodiurn dehydroxyacetate ;
(42) 1-oxy-3-methyl-4-isopropylbenzene ;
(43) 2~bromo-2-nitropropane-1,3-diol ;

~O~Q99 (44) sodium p-toluenesulfon chloramide;
(45) l-hexadecylpyridinium chloride ;
(46) hexadecyltrimethylammonium brom~:1e ;
Among those industrial fungicides, IF-l to IF-8 are preferable.
3. Antiseptic (1) ~ -bromo-cinnamaldehyde ;
(2) N,N-dimethyl-N-phenyl-N'-(fluorodichloromethylthio)-sulfamide ;
4. Agricultural fungicide (1) A mixture of bis (dimethylthiocarbamoyl) disulfide, zinc dimethyldithiocarbamate and methylarsenic dimethyldithio-carbamate ;
(2) S-benzyl diisopropyl phosphorothioate (3) 0-ethyl diphenyl phosphorodithioate ;
(4) diethyl 4,4'-o-phenylenebis (3-thioallophanate);
(5) dimethyl 4,4'-o-phenylenebis (3-thioallophanate);
(6) N-(trichloromethylthio)-4-cyclohexene-1,2-dicarboximide;
(7) N-(1,1,2,2-tetrachloroethylthio)-4-cyclohexene-1,2-di-carboximide ;
(8) S,S-6-methylquinoxaline-2,3-diyldithiocarbonate ;
(9) pentachloronitrobenzene;
(10) methyl 1-(butylcarbamoyl)-2-benzimidazol carbamate;
(11) 2,4-dichloro-6-(o-chloroanilino)-1,3,5-triazine;

llOOQ99 (12) 2,3-dicyano-1,4-dithia-1,4-dihydroanthraquinone:
(13) 3-hydroxy-5-methylisoxazole ;
(14) streptomycin ;
(15) polyoxin :
(16) blasticidin S :
(17) kasugamycin :
(18) validamycin ;

(19) 4,5,6,7-tetrachlorophthalide ;

(20) N-(dichlorofluoromethylth~o)-N',N'-dimethyl-N-phenyl-sulfamide:

(21) tetrachloroisophthalonitrile :

(22) 2,4-dichloro-6-(o-chloroanilino)-1,3,5-triazine :

(23) ethyl p,p'-dichlorobenzylate :

(24) zinc ethylenebis (dithiocarbamate);

(25) manganese ethylenebis(dithiocarbamate);

(26) complex of zinc and manganese ethylenebis(dithiocarba-mate);

(27) dizinc bis(dimethyldithiocarbamate)ethylene bis(dlthiocarbamate);

(28) bis(dimethyl-thiocarbamoyl)disulfide:

(29) isomeric reaction mixture of 2,6-dinitro-4-octyl-phenyl crotonate;
Among the above fungicides,those numbered (21)-(29) are preferable.
5. Plant growth regulant (1) 4-chlorophenoxy acetic acid;
_ 9 ~

llOOQ99 (2) gibberellin ;
(3) N-(dimethylamino) succinamide;
(4) ~ -naphthylacetamide;
6. Herbicide (1) 2,4-D sodium salt;
(2) 3,4-dichloropropionanilide;
7. Repellent (1) 2,3,4,5-bis ( 2 -butylene)-tetrahydrofulfural;
(2) di-n-butyl-succinate;
Among the above active ingredients, insecticides are more suited for use in the apparatus of this invention.
These active ingredients can be used con~ointly with any of synergists, fugacity rate improving agents, deodorants, perfumes, etc. which are usually used. Preferable examples of the synergists are piperonyl butoxide, N-propyl isome, "MGK-264" (product of MCLAUGHLIN GORMLEY KING CO.,U.S.A., "Cynepirin-222" (product of YOSHITOMI PHARMACEUTICAL INDUST-RIES LTD., Japan), "Cynepirin-500" (product of YOSHITOMI
PHARMACEUTICAL INDUSTRIES LTD., Japan), "Lethane 384"
2Q (product of ROHM AND HAAS COMPANY, U.S.A.), "IBTA" (product of NIPPON FINE CHEMICAL CO.,LTD, Japan), "S-421" (product of SANYO CHEMICAL INDUSTRIES, LTD.,Japan). Preferable fugacity rate improving agents includ~ phenethylisothio-cyanate, dimethylester of himic acid, etc. Preferred deo-dorants are lauryl methacrylate (LMA), etc. Citral and citronellal are preferably usable as perfumes.

_ 10 --llO~Q99 The blowing agent to be used conjointly with the : active ingredient and, when desired, with various additives can be any of those generally used and capable of mainly evolving nitrogen gas on thermal decomposition. It is preferable to use compounds which will give off a gas at (~ O
a temperature of between about 7U C and about 300 C. The compounds having blowing temperatures far lower than 70 C
tend to decompose by themselves during storage The compounds with blowing temperatures much higher than 300 C are likely not to decompose when subjected to heat evolved from the heating element. Accordingly such compounds are s~
'~ not preferable. Examples of typical blowing agents are listed in Table 1 below.

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1100~99 Table 1 No. Blowin~ a~ent Abbreviation Blowing temp.(~) 1. azodicarbonamide AC 200 - 210 2. benzenesulfonylhydrazide BSH 100 - 160 3. p-toluensulfonylhydrazide TSH 110 4. p,p'-oxybis(benzensulfonyl- OSH 140 - 160 hydrazide) 5. dinitrosopentamethylene- DPT19C - 205 tetramine 6. N,N'- dinitro~o-N,N'-di- DDTP90 -- 105 methylterephtalamide 7. trihydrazinotriazine THT235 - 290 8. azo~isisobutyronitrile AIBN95 - 105 9. 4,4'-azobiscyano~aleric ACVA 120 acid 10. t-butylazoformamide BAFA147 - 149 11. 2,4-bis-(azosulfonyl) 2,4-TSH108 - 109 toluene 12. 2,2'-azobisisobutylo- AZ-A 92 amide 13. methy~2,2'-azobisiso- AZ-~ 85 butyrate 14. 2-(carbamoylazo)iso- CIB 105 butyronitrile 15. l,l'-azobiscyclohexane ACHC 115 -1- carbonitrile 110~

Among the blowing agents listed in Table 1, AC, OSH, DPT, AIBN and ACHC are preferable because they con-tribute to the increase in fugacity rate of an active in-gredient. AC in particular remarkably enhances the fugacity rate thereof~Produces a gas free of toxicity and pungent odor, and is therefore especially useful.
A blowing agent may be used with additives to reduce the blowing temperature. Preferable examples of the addltives are as followæ: "~yhos"(product of NATIONAL LEAD CO., LTD., U.S.A.), "Tribase"(product of NATIONAL LEAD CO., LTD.,U.S.A.), "~F-14"(product of ADECA ARGUS CO., LTD., U.S.A.), "OF-15"
(product of ADECA ARGUS CO., LTD., U.S.A.), "KV-68A-l"(product of KYODO YAKUHIN CO., LTD., Japan), "Mark-553"(product of ARGUS CHEMI. CO., LTD., U.S.A.), "Sicostab 60"(product of G. Siegle & Cv., U.S.A.), "Sicostab 61"(product of G.Siegle & Co., U.S.A.), Cd-stearate, Ca-stearate, Zn-stearate, Zn-octate, ZnO, Sn-maleate, ZnC03, urea, chrome yellow, carbon black, etc.
According to this invention, the amount of the blowing agent relative to the active ingredient can be determined suitably depending on the use of the resulting composition. Usually it is preferable to use at least about one part by weight of the blowing agent per part by weight ~f the active ingredient The effective fugacity rate progressive-ly increases with increasing proportion of the blowing agent, ~lOQ~99 but the use of too great an amount of the blowing agent will not produce significantly improved results. Prefer-ably about one to about 20 parts by weight of the blowing agent is used per part by weight of the active ingredient.
The active ingredient and the blowing agent are merely mixed together to prepare a fumigating mixture of this invention but, to ensure efficient production and ease of use, it is desirable to prepare the mixture in the form of powder granules, pellets, otherwise shaped pieces, paste or the like or to enclose the mixture in a bag of meltable and incom-bustible resin. The mixture may also be enclosed in an openable bag made of aluminum.
According to this invention, the mixture of an active ingredient and a blowing agent is heated indirectly with a heating element to thermally decompose the blowing agent without burning the mixture. In this invention, any of heating elements is useful ~nsofar as it is capable of indirectly heating the mixture to such a temperature at which the blowing agen~ can be decomposed toa gas without burning the mixture. Preferred heating elements are i) an exothermic substance capable of evolving heat by contact with water, ii) that capable of evolving heat by CQntact wi'h air and iii) means capable of evolving heat by application of an electric current.
Examples of typical exothermic substances using 1100~99 water are calcium oxide, magnesium chloride, alumin~m chlorlde, calcium chloride and ferric chloride, among which calcium oxide is most preferable since this compound gives off heat enough to elevate the temperature up to about 400~C without producing any harmful substances due to hydro-lysis thereof and the corrosion of a container accommodating this compound. For the most efficient heat generation, it is desirable that calcium oxide be in the form of about 1- to about 20-mesh pieces or grains. Preferably the reac-tion between calcium oxide and water is initiated not immedi-ately after the addition of the latter to the former but after the water added thereto has uniformly and satisfactori-ly permeated into the calcium oxide.
To retard the initiation of the exothermic reac-tion when calcium oxide comes into contact with water, the pieces or grains of calcium oxide can be coated with at least one of mineral oils, vegetable oils and fats, higher alcohols, polyhydric alcohols, higher fatty acids and deriv-atives thereof. The amount of water to be used is prefer-ably about 0.2 to about 3 times the stoichiometric amount, and is, for example, about 0.2 to about 3 moles per mole of calcium oxide. When blowing agents which will evolve a gas at lower temperatures are used, diatomaceous earth, acid clay, zeolite or like clay can be added to the exothermic substance so as to regulate the heating time and temperature to be given by the heat evolved from the substance.

Examples of exothermic substances using air are compounds which evolve heat on oxidation with the oxygen contained in air. More specific examples include a mixture of sodium sulfide and iron carbide and/or carbon black. Among them, a mixture of the above three substances is preferable. Preferably the mixture con-tains 40 to 60% by weight of sodium sulfide.
Examples of useful heating elements using an electric current are heating wires such as usual nichrome wires, heating carbon elements such as those produced by MATSUSHITA ELECTRIC INDUSTRIAL C0., LTD., Japan, semicon-ductors such as positive temperature coefficient thermistors, etc.
According to this invention, the mixture of an active ingredient and a blowing agent is indirectly heated by the heating element, preferably any of the above heating element~ iii). To heat the mixture indirectly, the mixture is contained in a suitable container, and the heat-ing element is disposed outside the container. Preferably the mixture and the heating element are accommodated in a container as separated from each other by a partition pro-viding a heat transfer surface. The container is made of heat resistant material such as an iron plate. The mixture and the heating element can be contained in the container in any desired arrangement within the container. The arrange-ments can be divided into three general types:

110~099 (i) Arrangement in which the mixture is positioned above the heating element with a substantially horizontal partition interposed therebetween.
(ii) Arrangement in which the mixture and the heating element are separated from each other by a substan-tially vertical partition.
(iii) Arrangement in which the mixture and the heating element are separated from each other substantially horizontally and vertically.
In the arrangements (ii) and (iii), it i8 prefer-able to arrange the two components concentrically when seen in a plan view, with either one of the two positioned out-side the other. In the case of concentric arrangement, the mixture may be accommodated in a plurality of separate com-partments. Several kinds of mixtures having varying effica-cies can be accommodated in the compartment6 respectivelyO
The mixture accommodating compartment has an open upper end which may be kept sealed until the apparatus i8 put into use. When a material such as polyethylene, poly-propylene, polyamide or the like which is meltable but is not burned with the heat evolved from the heating element is used for sealing the compartment, there is no need to remove the seal by hand when using theapparatus, nor any likehood of hand coming into contact with the mixture, hence convenient and safe.

llOOQ99 The meltable seal can be covered with another film or sheet for reinforcing the seal. The covering film or sheet has a number of perforatlons and may be made from metal such as iron, aluminum or alloy thereof,synthetic resin or paper.
The heating element is a~commodated in a compart-ment provided ad~acent to the compartment containing the mixture of active ingredient and blowing agent. The com-partment for accommodating the heating element may be option-ally closed or opened, but is usually closed to eliminate heat losses. Preferably the container has an outer wall of heat in~ulated construction to minimize the heat loss and assure safety in handling.
When using the exothermic substance a~ the heating element, the clo~ed compartment is provided with means for supplying water to the exothermic substance. For instance, the water supplying mean~ i~ in the form of at least one water inlet aperture formed in an upper portion and/or lower portion of the closed compartment or comprises a water reservoir which can be opened from outside.
2~ The water reservoir is made from a film of easily breakable material such as an aluminum foil or synthetic re~in filmO
Examples of means for opening the water reservoir from outside, although not particularly limited, are pre-ferably as follows:

110~99 (i) A thread attached to the water reservoir and adapted to be pulled from outside to break the portion of the reservoir where the thread is attached.
(ii) A needle adapted to puncture the water reservoir when pushed into the container from outside.
(iii) ~ cutter provided within the container and dis-placeable from outside to cut the water reservoir.
(iv) One of the means (i) to (iii) which is so arranged as to cause the exothermic substance to contact paJt ~f the water contained in the reservoir, permitting the resulting heat to melt and break the meltable film which forms the water reservoir. The sealing materlals exemplified above are usable for the meltable film.' When the means (ii) or (iii) is u~ed, the closed compartment ls provided with suitable means for restraining ~he needle or cutter from inadvertent displacement.
Preferably water can be applied to the exothermic substance in such a manner that water placed in the bottom of the container i6 introduced through water inlet apertures in a lower part of the container into a water permeable layer provided ln the closed compartment from which the water comes into contact with the exothermic substance. The water-permeable layer, when employed, allows water to be applied to the exothermic substance uniformly over an increased area for efficient heat generation. The seeping rate of the water l~OQQ99 through the layer is suitably adjustable by varying the density, material and thickness of the layer. When such a water-permea~e layer forms the bottom wall of the closed compartment, water can be supplied to the exothermic sub-stance without the necessity of forming water inlet aper-tures in the bottom wall. Alternatively a water-permeable layer impregnated with water and sealed with a meltable film may ~e provided within the closed compartment, prefer-ably in combination with one of the opening means (i) to (iii) as already stated.
The water-permeable layer has numerous minute spaces as in open-cellular foamed materials and mats of fibrous material. The layer can be made from any water-permeable material. Examples of useful materials are woven an~ nonwoven fabrics of polyethylene, polypropylene, polyvinylidene chloride or like synthetic fibers, or of a blend of such synthetic fiber~ and cotton, mats of glass wool, asbestos, rock wool or like inorganic fibers, filter paper or like paper made of pulp, etc.
The exothermic substance filling the clo~ed compartment expands on application of water and also raises the internal temperature of the compartment owing to the re-sulting heat generation, so that the internal pressure of the container will build up to a very high level. According-2~ ly an opening for maintaining the internal pressure in balance with the atmospheric pressure can be formed in the wall defi-ning the closed compartment~

11~99 Electric heating elements, when used, are pro-vided preferably in ~uch manner that the heat evolving portion of the element will be in direct contact with part or whole of the partition providing a heat transfer surface, namely of the container wall accommodating the mixture, or will fit to the wall with a heat releasing plate interposed between that portion and the wall. The electric heating element has the advantage of giving a suitable amount of heat with ease at any time desired merely by being connected to an appropriate power æupply. Accordingly the electric heating element ls u~able repeatedly for fumigation in combination with a replaceable cartridge which contains the mixture to be thereby heated and which may be service-able also as the container for the mixture.
When heating elements which evolve heat on con-tact with air are used, the element is usable in the form of particles to grains, a sheet or plate or in some other suitable form as contained in an apprnpriate portion of the apparatu~. The heating element mu6t be held out of con-tact with air, namely in a hermetic state or in an inert gas atmosphere, before the use of the apparatus and must further be maintained in contact with air during use.
This can be done easily by encloslng the heating element in a bag of material, such as an aluminum foil, which is impervious to air but readily openable, or by accommodating the heating element in an open compartment of the apparatuS
and sealing the opening as with an aluminum film. In the latter case, it is preferable to place the heating element into the compartment in a nitrogen gas or like inert gas atmosphere. The heating element thus enclosed can be ex-posed to air by opening the bag or the seal covering the opening of the compartment.
When the heating element evolves heat, the heat indirectly heats the mixture containing the active ingre -dient through the partition, thereby decomposing the blow-ing agent and vigorously volatilizing the active ingre-dient. According to this invention, the active ingredient can be very eff~ctively volatilized in a large quantity within a short period of time, e.g. a few minutes or ten-odd minutes, presumably because the blowing agent mixed with the active ingredient gives off a gas on decomposi-tion, forcing the active ingredient to volatilize prompt-ly from the interior of the mixture and because the active agent per se remainæ free of decomposition due to combus-tion. The method of this invention, which is capable of very efficientiy quickly releasing large quantities of vapors of active ingredients, is useful in controlling noxious insects, ~uch as flies, mosquitoes, fleas, bed bugs, house ticks and cockroaches, which are detrimental to man, as well as plant lice, green house whiteflies, caterpillars and other insects which are harmful to 110~9~

agricultural plants, and is also servlceable for fungi-cidal and incensing purposes. Additionally ~he present method is usable for these applications with high safety and great convenience æubstantially without involving combusition which would produce smoke with toxicity or a pungent odor.

110~99 This invention will be described below in greater detail with reference to apparatus suitable for practicing the present method ~d shown in the accompanying drawings, in which:
Figs. 1-45 each show preferred embodiments of the present apparatus utilizing as the heating element an exothermic substance which evolves heat on contact with water;
Fig. 1 is a view in vertical section showing an , 10 embodiment ol` the invention in which the bottom wall of a container is formed with water inlet apertures;
Fig. 2 is a bottom view showing the water inlet apertures of the container shown in Fig. l;
Figs.3 and 4, Figs. 5 and 5A, Figs. 6 and 7, Figs.8 and 9, Figs. 10 and 11, and Figs. 12 and 12A are plan views and vertical sections respectively taken on lines III - ~Is V - V, Vl - VI, VIII - VIII, X - X, and XII - XII which show embodiments of this invention compris-ing a container having the same water supplying means as in the embodiment of Figs. 1 and 2;
Figs. 13 and 14, and Figs. 15 and 16 are plan views and vertical sections respectively taken on lines XIII - XI~ and XV - XV which show embodiments of this invention comprising a container with at least one water inlet aperture formed in its upper portion;

Fig. 17 and Fig. 18 are vertical sections show-ing modifications of the embodiment illustrated in Figs.
15 and 16;
Figs. 19 and 20, Figs~ 21 and 22, and Figs. 23 and 24 are plan views and vertical sections taken on lines XIX - XIX, XXI - XXI and XXIII - XXIII which show embodi-ments of this invention comprising a container having its top portion a water inlet aperture provided with a water inlet tube;
Fig. 25, Fig. 26, Fig. 27 and Fig. 28 are views in vertical section each showing an embodiment of this invention in which a container incorporates a water reservoir;
Fig. 29, Fig. 30, Fig. 31, Pig. 32, Fig. 33 and Fig. 34 are views in vertical section each showing an embodiment of this invention in which water is supplied to an exothermic substance through a water-permeable layer;
Fig~, 35 and 36 are a plan view and a view in vertical section taken on lines XXXV - XXXV which show an embodiment of this invention in which a container is provided with means for attaching the apparatus to a wall;
Fig. 37 is a view in vertical section showing an embodiment of this invention in which a compartment accommodating a mixture of active ingredient and blowing agent is sealed with a meltable film;

1~0~99 Figs.38 and 39 are a view in vertical section and a plan view showing a preferred case for enclosing the apparatus of this invention;
Fig. 40 is a view in vertical section showing another preferred case for enclosing the apparatus of this invention;
Fig. 41 is a plan view in develop~ent showing the case;
Fig. 42 is a view in vertical section showing the case during use;
Fig. 43, Fig. 44 and Fig. 45 are views in vertical section each showing an embodiment of this invention provided with means for supplying a specified amount of water;
Fig. 46, Fig. 47 and Fig. 48 are views in vertical section respectively showing preferred embodiments of the apparatus of this invention utilizing an electric heating element; and Fig. 49, Fig. 50, Fig. 51 and Fig. 52 show embodi-ments each incorporating a heating element which evolves heat on contact with air.
Figs.1 and 2, Figs. 3 and 4, Figs. 5 and 5A, F'igs. 6 and 7, Figs. 8 and 9, Figs. 10 and 11, and Figs.
12 and 12A respectively show embodiments of this inverltio each comprising a container 1 with water inlet apertllres 5 formed in its bottom wall la. The heating element is formed of an exothermic substance which evolves heat on contact with water.
The container 1 of Figs. 1 and 2 accommodates a mixture B of an active ingredient and a blowing agent in its upper open compartment 2 and an exothermic substance C in its lower closed compartment 3 separated from the mixture B by a partition 4. In Figs. 3 and 4 and Figs.
5 and 5A, the mixture B and the substance C contained in the container 1 are separated from each other by a vertical partition. The mixture B and the exothermic substance C
shown in Figs. 6 and 7, and Figs. ~ and 9 are accommodated in the container 1 as vertically and horizontally separated from each other, with the mixture B placed at an upper position of the substance C.
In Figs. 10 and 11, and Figs. 12 and 12A, the mixture B is accommodated in the open compartment 2 of the container 1 as divided into a plurality of small portions, in which case the portions need not always be of the same kind, but several kinds of mixtures B of vary-ing compositions and efficacies may be contained separately.
When the bottom of the container 1 is placed in water a in use of the apparatus shown in Figs. 1-12A, the water enters the closed compartment 3 through the water inlet apertures 5 in the bottom wall la of the closed llO~Q99 ; compartment 3 of the container 1 and comes into contact with the exothermic substance C contained in the closed compartment 3, causing the substance to evolve heat.
The heat indirectly heats the mixture B in the open compartment 2 of the container 1 through the partition 4, thereby decomposing the blowing agent in the mixture B and vigorously volatilizing the active in~redient.
On absorbtion of water, the exothermic substance C expands and gives off heat, increasing the internal pressure of the closed compartment 3 and impeding smooth ingress of the water through the inlet apertures 5.
Uneven heat generation will then result. It is therefore desirable that the container 1 be formed~ in its side wall lb or top wall lc, with a balance opening 6 for maintain-ing the interior of the closed compartment 3 in communi-cation with the atmosphere.
As seen in Figs. 1 and 4, the bottom wall la of the container 1 is preferably detachable for use with a refill of the exothermic substance.
Fig. 9 shows water inlet apertures 5 formed in the bottom wall la and lower portion of the side wall l_ of the container 1.
Figs. 13 and 14, and Figs. 15 and 16 respectively show other embodiments of this invention each comprising a container 1 with at least one water inlet aperture 5 11~0~99 formed in the upper portion of its enclosed compartment 3.
These embodiments need not be provided with the above-mentioned balance opening, since the water inlet aperture 5 is serviceable also as such.
As shown in Figs. 14 and 16, preferably a water receptacle 7 is provided in the upper portion of the containerand the water inlet aperture 5 is formed in the bottom of the water receptacle 7.
Figs. 17 and 18 show modifications of the embodi-ment illustrated in Fig. 15. The modifications of Figs.
17 and 18 are substantiallythe same as the embodiment of Fig. 15 except that the partition of Fig. 17 has a curved lower part, while that of Fig. 18 has inclined side parts.
Figs. 19 and 20, Figs. 21 and 22, and Figs. 23 and 24 respectively show other embodiments cr this inven-tion each comprising a container 1 having in its top portion a water inlet aperture 5 provided with a water inlet tube 8.
The water inlet tube ~ extends almost to the bottom of the container 1 to supply water to a bottom portion of an exothermic substance C filling a closed com-partment 3 of the container 1. This arrangement enables the exothermic substance C to start heat generation at the bottom portion. For example, when water is supplied according to the embodiment of Figs. 13 and 14 to the llO~Q99 exothermic substance C through the water inlet aperture 5 in the upper part of the container 1, heat generation is initiated at the upper part of the exothermic substance C, and the water thus heated is partly vaporized, thereby involving a loss of water. Consequently the lower part of the éxothermic substance mi~ht possibly remain with-out evolving heat. The use of the water inlet tube 8 prevents such undesirable loss of water, thus ensuring complete consumption of the substance for heat generation without any waste.
Figs. 25 to 28 respectively show other embodi-ments of this invention in each of which a water reservoir 9 is incorporated in a closed compartment 3 of a container 1. The water reservoir 9 contains a sufficient amount of water required for the heat generation of an exothermic substance C.
The embodiments of Figs. 25 and 26 have a thread 10 which can be pulled from outside to break the water reservoir 9 when so desired, and those of Figs. 27 and 28 have a needle 11 for puncturing the water reservoir 9 a~d a pin 12 for retaining the needle 11 in posltion.
The pin 12 is removably inserted in the hole ~not shown) of the needle 11. When the pin 12 is removed, the need~e 11 is freely movable upward or downward.
Fig. 26 shows a balance opening 6 formed in

- 30 -110~99 an upper end peripheral curled portion of the container 1.
Figs. 29 to 34 respectively show other embodi-ments of this invention which are so adapted that water is supplied to an exothermic substance C through a water-permeable layer 13.
With the embodiments of Figs. 29 to 31, the water supplied through water inlet apertures 5 seeps through the water-permeable layer 13 and comes into con-tact with the exothermic substance C to cause the substance C to evolve heat. Since the water seeps through the layer 13 over the entire surface area thereof, this arrangement assures very efficient heat generation.
When the water inlet apertures 5 are formed in the bottom wall la or lower portion of the side wall lb f the container 1 as shown in Figs. 29 and 31, the water-permeable layer 13 separates the exothermic substance C
from the water inlet apertures 5, preventing the substance C from falling through the apertures 5, so that the water inlet apertures 5 can be of relatively large diameter.
Figs. 32 to 34 show embodiments of the type in which water is supplied from a water reservoir 9 to a water-permeable layer 13. With the embodiment of Fig. 32, the main body of a container-l is depressed, with retain-ing pins 12 removed, to break the water reservoir 9 for the application of water to the layer 13. With the embodi-

- 31 -.~, 1104~Q99 ments of Figs.33 and 34, a thread 10 is pulled to break the reservoir 9.
Figs. 35 and 36 show another embodiment of this invention including a container 1 which is mountable on a vertical wall, column, ceiling and others. The container 1 has a lug 15 pro~ecting from its upper end periphery and having a hole 14. A hook (not shown) on a wall, column, ceiling or the like is engageable in the hole 14 to support the container.
Fig. 37 shows another embodiment of this inven-tion in which a compartment accommodating a mixture B
has an open end which is sealed with a meltable film 16.
The film 16 is removable by being melted with the heat evolved from an exothermic substance C and the heat of the gas released from an active ingredient with that heat.
The apparatus of this type is convenient to use since the seal over the mixture accommodating compartment need not be separated before use.
Figs. 38 and 39, and Figs. 40 to 42 respectively show preferred cases for enclosing an apparatus A accord-ing to this invention of the type in which water inlet apertures 5 are formed in the bottom wall la of a container 1. When opened, the case 17 (23) is usable as a container for water.
With reference to Figs. 38 and 39~ a cover 1 ~10~99 is detachable from the case 17. The cover 18 is detached from the case when water is introduced into the case.
The cover 18 is refixed to the case 17 after the supply of water. The cover 18 has an opening 19 serving as a passage for the vapor given off from the mixture B in the open compartment 2.
The case 17 and the apparatus A enclosed therein define an annular space 20 which serves as a heat insulat-ing portion for protecting the case 17 from the heat evolved from the exothermic substance C.
The case 17 has projections 22 of small width provided on its bottom and extending radially from the center thereof. The proJections 22 support the apparatus A thereon and form spaces 21 beneath the apparatus A, the spaces 21 serving to accommodate the water to be supplied to the apparatus A through the water inlet apertures 5 in the bottom of the apparatus. The pro-jections 22 each have an upwardly outwardly sloping top face 22a, rendering the apparatus accurately positionable within the case 17 concentrically therewith.
The case 23 shown in Figs. 40 to 42 is of the same construction as the case 17 except that the case 23 comprises an outer case member 23a of the knockdown type and a plastics inner case member 23b disposed within the outer case member 23a concentrically therewith.

ll~gg Fig. 41 is a development showing the outer case member 23a. The top cover portion thereof comprises cover pieces 25, 25 extending from the upper ends of the opposite side walls 23a', 23a' of the outer case member 23a with folds 24, 24 formed therebetween. One of the cover pieces 25 further extends outward intoan attaching piece 27 with a perforated fold 26 formed at the outer end of the cover piece.
When the present apparatus is to be used, the cover pieces 25, 25 are unfolded to a semi-open position as shown in Fig. 42. In this state, openings 28, 28 are formed on the opposite sides of the cover pieces 25, 25.
The vapor released from the apparatus is diffused into the outside atmosphere through the openings 28, 28. To ensure more efficient diffusion, one of the cover pieces 25 can be formed with holes 29 (see Fig. 41). To retain the cover pieces 25 in a semi-open position, one of the opposed ends of the cover pieces has a tongue-like insert piece 30 and the other end a cutout 31 for receiving the insert piece 30.
As seen in Fig. 40, the inner case member 23b has a seal 32 closing its open upper end. The seal 32 is removed when the apparat~s is put to use.
Fig. 43, Fig. 44 and Fig. 45 are views in vertical section each showing an embodiment of this inven-ll~OQ99 ' tion provided with means for supplying a specified amount of water.
With reference to Fig. 43, a container 1 is provided on one side thereof with a water receptacle 33.
An overflow opening 34 is formed in the outer wall 33a of the receptacle 33 at a suitable level. The lower end of the receptacle 33 communicates with a slit 35 provided beneath the bottom of the container 1. The bottom of the container 1 has water inlet aperture 5 opened to the slit 35. The portion where the lower end of the water receptacle 33 communicates with the slit 35 is provided with a seal 36 which is opened after water has been placed into the receptacle 33. When made of water-soluble material, the seal 36 is openable without being opened by hand.
When the level of the water placed into the receptacle rises beyond the overflow opening 34, excess water ~lows out from the opening 34, with the result that a predetermined amount of the water remains in the receptacle 33. The seal 36 is thereafter removed, permitting the water to enter the slit 35 from the lower end of the receptacle 33 and to flow into the container 1 via the water inlet apertures 5 opened to the slit 35.
When a water-permeable layer 13 of suitably selected material is provided on the bottom of a container 1 as seen in Fig. 44, the layer 13 also has substantially the same function as the seal 36 shown in Fig. 43, thus ellminating the necessity of providing a seal between the water receptacle 33 and the slit 35.
Fig. 45 shows a container 1 having in its top portion a water receptacle 7 the side wall of which is formed with an overflow opening 34 for ensuring the supply of a specified amount of water. The receptacle 7 has a water inlet aperture 5 which is closed with a seal 37. The seal 37 is removed after the specified amount Or water has been placed into the receptacle 7.
Throughout Fig. 1 to Fig. 45, like numerals indicate like members. A supply of water to the exothermic substance in the closed compartment according to the embodiments of Figs. 13 to 45 achieves substantially the same results as with the embodiments of Flgs. 1 to 12A.
Figs. 46 to 48 show apparatus each uti]izing an electric heating element. With the apparatus of Fig. 46, a mixture of an active ingredient and a blowing agent and the heating element are separated from each other vertically and horizontally, whereas Figs. 47 and 48 each show an apparatus in which the mixture is positioned above and separated from the heating elemrnt. The heating elements used in these apparatus are a heating wire (Fig. 46), a heating carbon element (Fig. 47) and a llOQO99 thermistor of positive temperature coefficient (Fig. 48).
Each of these heating elements 101 evolves heat upon application of an electric current by being connected to a suitable power supply outside the apparatus. This connection is effected for example via a terminal 103 provided-within a compartment 102 of the container accommodating the heating element 101 and a cord 104 extending outward from the wall of the compartment 102 as seen in Fig. 46, or by way of a plug 105 fixed to the wall of the compartment 102 as seen in Fig. 48. In view of safety, the heating element 101 can be surrounded by an insulating plate 106. A heat releasing plate 107 can be interposed between another compartment 108 of the con-tainer accommodating the mixture of active ingredient and blowing agent, i.e. mixture B as seen in Fig. 47 and the heating el~ment 101 to achieve an improved thermal effi-ciency. With the apparatus of Fig. 46 and Fig. 47, the compartment 108 containing the mixture B is fitted in the upper portion of the compartment 102 accommodating the heating element 101 and serving as the main body, in whlch case the mixture B is replaceable as desired along with the compartment 108. The main body of the apparatus is therefore advant~geous in that it is usable repeatedly for the same purpose or for different applications. The apparatus of Fig. 48 includes a compartment 108 accommodat-llOOQ9g lng the mixture B and secured to the upper portion of the compartment 102 containing the heating element 101, in which case the walls Or compartment 108 areserviceable also as a heat releasing plate. This apparatus is repeatedly usable by replacing the mixture B only. The compartment 108 for ~he mixture B may have an open upper end, but the opening is preferably kept sealed until the apparatus is put into use, for example, with a meltable film 111 as seen in Fig. 47. The seal is convenient in that it is spontaneously removable with the heat emitted from the heating element 101. It is desirable that the outer wall of each of the foregoing apparatus, especially the outer wall of the compartment containing the heating element 101, be of heat insulated construction.
Figs. 49 to 52 show embodiments each incorpo-rating a heating element which evolves heat on contact with air. The heating element 101 shown in Fig. 49 is in the form of a molded sheet and accommodated in a compartment 102. A container forming a compartment 108 containing the mixture B is fitted ln the upper portion of the compartment 102 in intimate contact therewith.
The heating element 101 shown in Fig. 50 is in the form of grains and placed in a hollow cylindrical compartment 102 which is formed in a compartment 108. The outer com-partment 108 concentric with the inner compartment 102 llOQQ99 contains the mixture B. With the apparatus of Fig. 51 comprising a hollow cylindrical container of the double wall structure, the heating element 101 is shaped in the form of a hollow cylinder and conversely fits around an inner compartment 108 containing the mixture B. With the apparatus shown in Fig. 52, the heating element 101 is intimately fitted over the side and bottom walls of a compartment 108 containing the mixture B and is thereby separated from the mixture B.
With the apparatus of Fig. 49 to 52, the com-partment 102 containing the heating element 101 is sealed with a film 109 which is impervious to air and easily openable. When the heating element 101 is dis-posed in a lower portion or in lower and side portions f the apparatus as sho~n in Fig. 49 or Fig. 52, the bottom of the compartment 102 containing the heatlng element 101 is formed with air apertures 110, and the bottom is covered with the film 109 from outside. In the case of concentric arrangement as shown in Figs.
50 and 51, the upper end of the compartment 102 is sealed with the film 109. The heating element 101 evolves heat when the seal portion is opened to expose the element 101 to air, thus indirectly heating the mixture B con-tained in the compartment 108 through the partition providing a heat transfer surface, namely the bottom or ~lOQ~gg side wall of the compartment. The apparatus utilizing the heating elements which evolve heat on contact with air are all very simple in construction and easy to use and require no power supply.
Throughout Fig. 46 to Fig.52, like numerals indicate like members.
This invention will be described below in greater detail with reference to examples, in which the effective fugacity rates of active ingredients are determined by volatilizing the ingredient within a closed container, passing the air within the container through a solvent which completely disolves the active ingredients, such as benzene, acetone, water, chloroform or dichloromethane to cause the solvent to absorb the vaporized ingredient in the air, concentrating the solvent and sub~ecting the concentrate to gas chromatography.
The fugacity rate is expressed in terms of the ratio in percent of the quantity of the active ingredient to the quantity of the ingredient initially admixed with a blow-ing agent.

- 4~ -llOOQ99 ' Example 1 A mixture of an insecticide and a blowing agent as listed in Table 2 is placed into an apparatus of this invention utilizing 100g of calcium oxide (l-to 5-mesh pieces) and shown in Fig. 29. The apparatus is brought to contact with water and 40 g of water enters into a com-partment accommodating calcium oxide via inlet apertures in its bottom wall to heat the mixture to a temperature of up to about 300 to about 350C with the resulting heat, whereby the blowing agent ls thermally decomposed to volatilize the insecticide. The effective fugacity rate of the insecticide is determined.
The results are shown in Tables 2.
Table 2 effective Specimen blowing fugacity No. insecticide (g) a~ent (g) rate(%) 1 allethrin B 1 AIBN 5 69.4 2. DDVP 1 TSH 10 61.1 3. " 1 2,4-TSH 10 63.o 4. " 1 OSH 10 74.2 5. allethrin A 1 AZ-A 10 69.1 1 AZ-B 10 65.6 7. '! 1 CIB 10 61.6 8. " 1 ACHC 10 63.2 9 allethrin B 1 AC 1 65.3 10. " 1 AC 3 74.9 11. " 1 AC 5 86.7 12. allethrin A 1 AZ-B 10 63.0 13. DDVP 1 OSH 10 70.1 llOOQ99 effective Specimen blowing used fugacity No. insecticide used(g) agent (g) rate(%) 14 allethrin A 1 CIB 10 60.5 allethrin B 1 AC 1 60.8 16 l~ 1 AC 3 72.9 17 resmethrin 1 AC 5 83.4 i 18 ~ 0.5 AC 2 75.0 i 19 " 0.5 AC 4 84.0 ; 20 " 0'5 AC 5 82.3 1 21 0 5 AC 10 79.8 j 22 " 0.5 DPT 1.5 80.8 23 phthalthrin 0.5 AC 5 63.0 24 phenothrin 0.5 AC 5 75.5 permethrin 0.5 AC 5 78.1 26 DDVP 0.5 AC 4 78.2 27 resmethrin1 / AC 65.2 AZ-B
28 allethrin B 1 AC 68.1 ! ( AIBN
Comparative Example 1 The same procedure as in Example 1 is repeated without using any blowing agent. Table 3 shows the results.
Table 3 effective Specimen blowing fugacity No. insecticide (g) agent ~g) rate (%) 29 resmethrin 1 - - 0.3 allethrin B 1 - - 0.7 Comparative Example 2 To a cylindrical container with a single compart-ment accomodating 100 g of calcium oxide con~ointly with an insecticide only or with an ~lOQQ99 insecticide and a blowing agent listed in Table 4 is supplied 40 g of water in the same manner as in Example 1 to determine the effective fugacity rate achieved. Table 4 shows the results.
Table 4 effective Specimen blowing fugacity _ No. insecticide (g) agent (g) rate (%) 31 resmethrin 1 0.2

32 allethrin B 1 0.3

33 resmethrin 1 AC 5 4.2

34 allethrin B 1 AC 5 5.1 Comparative Example 3 The mixtures listed in Table 5 each composed of an insecticide and a comsubtible material as in known fumigants, were burned for fumigation. Table 5 also shows 15 the effective fugacity rates achieved.

Table 5 effective Specimen combustible fugacity _ No. insecticide (g) material (g) rate (%) resmethrin 0.5 nitrocellulose 3 6.3 (30%) 36 allethrin B 0.5 " 3 1.7 37 phthalthrin 0.5 " 3 7.2 38 phenothrin 0.5 " 30 8.1 39 permethrin 0.5 " 30 8.6 Tables 2 to 5 show that the method of this inven-tion using present apparatus can achieve remarkably improved effective fugacity rate.

110~99 Example 2 The same procedure as used in Example 1 is repeated with the exception that a blowing agent containing an additive is used as shown in Table 6.
The results are als~ given in Table 6.

_able 6 effective Specimen blowing fugacit~ rate No. insecticlde (g) agent (g) (~0) resmethrin 1 CELLMIC 5 86.8 CAP*

41 ' 0.5 CE*L*LMIC 5 87.5 * "CELLMlC CAP" is an AC-type blowing agent manufactured by SANKYO KASEI CO.,LTD.,Japan ** "CELLMIC AN" is a blowing agent manufactured by the same company and containing a mixture of 50% DPT and 50% urea as an additive.

Table 6 reveals that the use of the additive with the blowing agent achieves the results as excellent as those shown in Table 2.

Example 3 The same procedure as used in Example 1 is repea-ted except that to the active ingredient is added a syner-gist (for Specimens No. 42 to No. 46), a deodorant or perfume (for Specimens Nos. 47 and 48) or a fugacity rate improving agent (for Specimens Nos. 49 and 50) as shown in llO~Q99 Table 7, which also shows the results.

Table 7 effective Specimen blowing fugacity No. insecticide (g) additive (g) agent (g) rate(%) 42 resmethrin 1 S-421 2 AC 3 79.4 43 " 1 ~iperonyl 3 l 5 85.8 butoxide 44 " 1 Lethane 384 3 " 5 85.5 " 1 Cynepirine- 3 " 5 87.7 46 " 1 Cynepirine- 3 " 5 86.2 47 " 0.5 citral 0.1 " 2 82.4 48 ' 0.5 LMA 0.1 " 1 78.1 49 ~ 0.5 ph~nethYl- 1 CELLMIC 5 90.3 isothiocya- AN
nate 5o ~' 0.5 dimethyl ester of 1 CELLMIC 5 89.6 himic acid AN
Table 7 shows that the use of the additiVe with the active ingredient achieves the results as excellent as those shown in Table 2.
Example 4 The same procedure as used in Example 1 is repea-ted except that a heat generation regulating agent listed in Table 8 is added to the calcium oxide. Table 8 also shows the results.

~lOOQ99 Table 8 heat generation effective Specimen blowing regulating fugacity No. insecticide (g) agent (g) agent (g) rate (%) -51 resmethrin 1 AC 5 zeolite 5 87.4 52 " 1 " 5 acid clay 10 88.5 53 " 1 " 5 diatoma- 10 88.2 ceous earth Apparatus of the invention are tested for the quantity of smoke evolved, toxicity and insecticidal effect.
Quantity of smoke (turbidity) An apparatus of this invention accommodating the same mixture as Specimen No. 20 is used in a chamber 90 cm x 90 cm x 90 cm to volatilize the active ingredient. For com-parison, a fumigating compositions composed of 30g of a combustible material and 1.5 g of DDVP is burned in the same chamber as above.
The chamber is transparrent in the upper part and is lit up with a fluorescent light (20w) provided in the upper center of the chamber. A marking plate is horizontally disposed in vertically movable manner in the chamber. The marking plate is a white disc made of plastic with a diameter of 35 mm. On the disc are drawn four black lines 0.5mm in width such that two pairs of lines are intersected at a right angle in the center of the disc, two lines of each pair being spaced in parallel with a distance of l.Omm. The above disc .~

110~99 ls vertically moved to measure a distance (h) between the top of the chamber and the disc when the four lines on the disc ar~ clearly seen with unaided eyes. In this way, a turbidity within the chamber is calcul~ted by the followlng equation:

turbidity (%) = h (cm) ~ 100 90(cm) The same procedure is repeated five times for each specimen, glving the following average data shown in Table 9.

Table 9 distance(cm) turbidity(%) present invention: 67 74.4 Comparison : 16 17.8 The results indicate that the ~uantity of smoke emitted from the apparatus of this invention is substantially negligible.
Toxici~ (determined by exposure to fumigatlng vapor) A toxicity test is conducted under the following conditions.
(1) Apparatus A: Apparatus accommodating specimen No. 18 Or this invention.
B: Apparatus accommodating specimen No.20 of this invention.
(2) Device Chambers, lm x lm x lm (i.e. lm3).
(3) Animals Five-week-old mice JCL: ICR
(4) Method l~O~Q99 Five male mice or five female mice are placed lnto a chamber, the interior of the chamber is fumigated with one or two apparatus and the animals are left confined in the chamber for 2 hours.
The animals are thereafter placed into an ordinary cage and given a diet and water.
(5) Results Tables 10 and 11 show the results.

Table 10 Test. number of deaths No. Apparatus immediately one day ~ two days after the after the after the fumigation fumigation fumigation M. F. M. F. M. F.
1 A (one) 0 0 0 0 0 0 2 B (one` 0 0 0 0 0 0 3 B ( two) 0 0 0 0 0 0 Specimens No.18 and No.20 used in the toxicity test produce no toxicity, and the test animals are alive 10 days after the fumigation. As shown in Table 10, high safety is ensured when using the present apparatus in a chamber having a concentration of the volatilized active ingredi-ent over 30 times the concentration thereof at which a satisfactory insecticidal effect is achieved.
Table 11 shows the changes in the body weight of ~10~099 the animals surviving the test.
Table 11 Test animal's changes in the body weight of the animals No. sex (average ~) before 1 day 2 days 4 days 6 days 8 days lOday test after after after after after after 1 M. 26.2 27.3 26.2 29.6 29.4 29.6 31.4 F. 22.2 22.4 21.6 23.0 23.4 22.4 23.2 2 M. 24.8 26.2 25.6 28.4 27.0 28.4 29.8 F. 22.4 22.6 21.8 24.0 23.8 24.4 24.6 3 M. 25.4 28.4 28.2 31.0 31.4 31.8 34.0 F. 22.0 22.0 21.4 22.8 23.4 23.6 24.4 Table 11 reveals that the specimens of the invention show substantially no harmful effect on the increasing rate of body weight of the tested an~mals and that they are sub-stantial]y free from toxicity. The amounts of food taken by the animals is slightly reduced only on the first day after the test but thereafter no change is observed.
Insecticidal effect 1. Specimens of this invention are tested for insecticidal effect under the following conditions.
(1) Test insects Adults of german cockroaches.

llOQO99 (2) Method A laboratory dish (24 cm in inside diameter and 6.5 cm in height) containing 25 test insects is placed in each corner of a closed room, 3 m x 4 m x 3 m (height), i.e. 36 m3, and the interior of the r~om is fumigated with a specimen placed in the center of the room. Knockdown is determined at a specified time interval after the initiation of fumigation. Two hours after the fumigation, the test insects are transferred to a rearing chamber, and mortality (%) is determined in 24 hours and 48 hours. In the rearing chamber, the insects are given a diet and water. Table 12 shows the results.
Table 12 ~ecimens No. I 11 24 25 20 ¦ 30 min. 55 51 46 53 Knockdown 1 60 min. 99 96 84 100 (%)90 min. 100 98 95 100 ' 120 min. 100 100 100100 24 hr. 78 66 97 80 Mortality I
(%) , 48 hr. 100 100 100100 Table 12 shows that the use of the present apparatus in a closed room leads to effective extermination of - 5Q - .

noxious vermin.
2. Specimens of this invention are further tested for insecticidal effect in a simulated living room.
(1) Test insects Adults of german cockroaches and adults of american cockroaches.
(2) Method A 76-cm-high desk having four drawers in layers is placed in one corner of a room, 3m in width, 4 m in length and 3 m in height, i.e. 36 m3. A wood ~ox (45 cm x 41 cm x 37 cm) is placed in another corner of the room as spaced apart by 2 cm from the wall, with its opening opposed to the wall. A closed box (measuring 30 cm x 30 cm x 30 cm and having 8 holes of 7 mm in diameter in its top side) is placed on a 150-cm-high shelf in the center of one of the longi-tudinal walls of the room, the box being positioned close to the wall.
Laboratory dishes (24 cm in inside diameter and 6.5 cm in height) each containing 20 adults of german cockroaches and 10 adults of american cockroaches are placed in various locations within the room. The interior of the room is fumigated with a specimen placed in the center of the room, and the insects are left conf1ned in the room for one hour. The insects are thereafter placed into a rearing case and given a diet and water. Mortality (%) is determined 24 hours and 48 hours after the start of the experiment.
The dishes are placed in the following locations:
Pl: In the open box.
P2: In the closed box.
P3: In the uppermost closed drawer of the desk.
P4: In the second highest drawer of the desk as withdrawn by 1 cm.
P5: In the lowermost drawer of the desk as withdrawn by 2 cm.
(3) Specimens Specimen No. 20.
(4) Results Table 13 shows the results achieved with the german cockroaches, and Table 14 those with american cock-roaches.
Table 13 Place Pl P2 P3 P4 P5 Mortality(%) 24 hr. 50 35 50 40 35 48 hr. 100 95 100 100 100 :1~0QQ99 Table 14 Place Pl P2 P3 P4 P5 Mortality(%)24 hr. 10 20 3 10 20 48 hr. 90 60 100 80 100 ~5 Tables 13 and 14 show that the apparatus of this invention is very effective at various locations.

Example 5 The procedure of Example 1 is repeated using the same apparatus as used therein, the apparatus containing a fungicide and a blowing agent listed in Table 15, which also shows the results.
Table 15 Specimen fungicide blowing effective No. (g) agent (g) fugacity rate(%) 54 IF-2 0.5 AIBN 5 60.1 " 0.5 AC 5 71.3 56 ~ 0.5 AZ-A 10 66-7 57 IF-8 0.5 AZ-B 10 6~.8 58 ~ 0.5 AIBN 5 68.4 59 " 0.5 ACHC 5 57.~
IF-7 0.5 AZ-B 5 57.9 61 " 0.5 AC 5 70.8 62 " 0.5 CIB 5 54.0 63 IF-6 0.5 DPT 1.5 6~.ll 64 IF-3 0.5 AZ-A 3 88.8 IF-2 0.5 AIBN 10 71.3 Specimen fugicide blowing effective No. (g) agent(g) fugacity rate(%) 66 IF-l0.5 AIBN 5 71.5 67 IF-40.5 AIBN 5 54.0 68 IF-31 ( AZ-A 2 56.4 Comparative Example 4 The procedure of Example 5 is repeated using an fungicide listed ln Table 16 but without using any blowing agent. Table 16 also shows the results.

Table 16 Specimen fungicide effective No. (g) fugacitY rate (%) 69 IF-5 l 6.5 IF-8 l 8.9 72 IF-2 1 10.8 Tables 15 and 16 reveal that the use of a blowing agent con~ointly with a fungicîde ena~les the fungicide to volatilize with an efficiency which is lO-odd times as high as the efficiency achieved by the same quantity of the fungicide at the same temperature.

Example 6 A mixture of an insecticide and a blowing agent as listed in Table 17 is placed into an apparatus of this invention utilizing a heating wire and shown in Fig. 46.
An electric current is applied to the wire to indirectly heat the mixture to a temperature of up to 300 C with the resulting heat, whereby the blowing agent is thermally decomposed to volatilize the insecticide. The effective fugacity rate of the insecticide is determined.
The same procedure as above is repeated except that a mixture of an insecticide, an additive and a blowing agent listed in Table 18 is used.
The results are shown in Tables 17 and 18.
Table 17 effective Specimen blowing fugacity No. insecticide (g) agent (g) rate (%) 54 allethrin B 1 AIBN 5 75.6 DDVP 1 TSH 10 66.5 56 " 1 2,4-TSH 10 68.6 57 " 1 OSH 10 74.6 58 allethrin A 1 AZ-A 10 63.4 59 " 1 AZ-B 10 60.2 6Q " 1 CIB 10 67.1 61 " 1 ACHC 10 68.7 62 allethrin B 1 AC 1 60.0 63 " 1 AC 3 69.3 64 " 1 AC 5 ~0.2 effective Specimen blowing fugacity No. insecticide (g) agent (g) rate (%) allethrin B 1 AC 10 79.0 66 vesmethrin 1 AC 1 62.0 67 ~ 1 AC 3 74.1 68 1 AC 5 76.5 69 " 0.5 AC 2 68.8 " 0.5 AC 4 77.0 71 " 0.5 AC 5 75.5 72 " 0.5 AC 10 73.2 73 " 0.5 DPT 1.5 77.3 74 phthalthrin 1 AC 5 60.2 phenothrin 0.5 " 5 69.2 76 " 1 " 5 71.6 77 permethrin 0.5 " 5 71.6 7~3 " 1 " 5 69.4 79 DDVP 0.5 " 5 79 3 Table 17 showsthat the process of this invention results in remarkably improved effective fagacity rate.

Table 18 effect.ve Specimen insectici.d~ additive blowing fu~acity No. (g) (g) agent (g) rate(%) _ resmethrin 1 S-421 2 AC 3 72.
81 " ]. ~piperonyl 3 " 5 78.7 82 " 1 Lethane 3 " 5 78.4 83 " 1 Cynepirine3 " 5 ~0 L~

ll~ooss effective Specimen insecticide additive blowing fugacity No. (g) (g) agent (g) rate(%) 84resmethrin 1 ~Cynepirine 3 AC 5 79.0 r 5 " 0.5 citral 0.1 " 2 75.5 86 " 0.5 L~A 0.1 ~' 1 70.0 87 " 0.5 phenethyl- l C~LLMIC 5 82.8 isothiocya- AN
nate 88 " 0.5 dimethyl 1 ' 5 82.2 ester of himic acid The specimen No. 71 is tested for the quantity of smoke evolved (turbidity), toxity and insecticidal effect described above. The results of the above tests are sub-stantially the same as those of the tests using the specimen No. 20. More specifically stated, the results of the tests with the use of the specimen No. 71 show:
i) substantially no smoke is emitted from the specimen;
ii) no toxicity is produced; and iii) noxious vermin are effectively exterminated.
Comparative Example 5 The same procedure as in Example 6 is repeated without using any blowing agent. Table l9 shows the results.

llOOQ99 Table 19 Specimen insecticide (g) effective fugacity No. rate (%) 89 resmethrin 1 0.6 allethrin B 1 2.9 91 phenothrin 1 1.3 92 permethrin 1 0.9 Comparative Example 6 The mixtures listed in Table 20 each composed of an insecticide and a combustible material as in known fumigants, were burned for fumigation. Table 20 also shows the effective fug~city rates achieved.

Table 20 effective Specimen insecticide (g) combustible (g) fugacity No material rate (%) 93 resmethrin 0.5 nitr(oce%)lulose 30 6.3 94 allethrin B 0.5 - 3 1.7 phthalthrin 0.5 " 3 7.2 96 phenothrin 0.5 " 30 8.1 97 permethrin 0.5 " 30 8.6 Tables17 to 20 show that the rnethod of this inven-tion using the present apparatus results in remarkably improved effective fugacity rate.
~xample 7 A mixture of an insecticide and a blowing agent as listed in Table 21 ls placed into the inner compartment ~lOOQ99 108 of an apparatus of this invention as shown in Fig. 49.
A heating element (20g) in the form of a mixture of 4 parts by weight of sodium sulfide and 6 parts by weight of iron carbide is broughtinto contact with air by removing the seal 109 to heat the compartment to about 300 C with the resulting heat from outside, whereby the blowing agent is thermally decomposed to volatilize the insecticide. The effective fugacity rate achieved by the insecticide is determined. Table 21 shows the results.
Table 21 effective Specimen insecticide (g) blowing agent (g) fugacity rate No. (%) 98 allethrin B 1 AIBN 5 69.3 99 DD~P 1 TSH 10 60.5 100 DDVP 1 2,ll-TSH 10 61.8 101 allethrin B 1 AC 3 73-5 102 allethrin A 1 AZ-A 10 63.5 103 " 1 AZ-B 10 61.0 104 allethrin B 1 AC 5 80.5 105 allethrin A 1 ACHC 10 66.0 106 resmethrin 1 AZ-~ 10 60.3 107 " 1 AC 3 70.2 103 " 1 AC 5 75.6 109 l~ 0.5 DPT 1.5 78.6 110 phthalthrin 0.5 AZ-A 10 60.4 ~lOOQ99 Example 8 A mixture of a fungicide and a blowing agent as listed in Table 22 is placed into the hollow cylindrical compartment 108 of an apparatus as shown in Fig. 46. The compartment is externally heated with the heating wire 101 S to a temperature of up to 300 C to thermally decompose the blowing agent and to thereby volatilize the ~nglcide. The effective fugacity rate achieved by the fungicide is determined. Table 22 also shows the results.
Table 22 effective Specimen fungicide (g) blowing agent (g) fugacity No. _ rate (%) 111 IF-2 0.5 AIBN 5 61.4 112 " 0.5 AC 5 71 3 113 " 0-5 AZ-A 10 60.7 114 IF-8 0.5 AZ-B 10 61.3 115 " 0.5 AIBN 5 57.8 116 " 0.5 ACHC 5 62.3 117 IF-7 0.5 AZ-B 5 61.0 118 " 0.5 AC 5 65.0 119 " 0.5 CIB 5 56.9 120 IF-6 0.5 DPT 1.5 72.1 121 IF-3 0.5 AZ-A 3 81.5 122 IF-2 0.5 AIBN 10 71-3 123 IF-l 0.5 " 5 75.3 124 IF-4 0.5 " 5 55.4 125 IF-7 1 ~ AZ-A 57.9 lAZ-B 2 ll~)QO99 Comparative Example 7 The procedure of Example 8 ls repeated using a fungicide listed in Table 23 but without using any blowing agent. Table 23 also shows the results.

Table 23 Specimen fungicide (g) effective No. fugacity rate (%) 127 IF-8 1 9.0 128 IF-7 1 2.0 129 IF-2 1 11.0 Tables 22 and 23 reveal.. that the use of a blowing agent cor,~ointly with a fungicide enables the fungicide to volatilize with an efficiency which is ten-odd times to several tens of times as high as the efficiency achieved by the same quantity of the fungicide when it is heated alone at the same temperature.

Claims (34)

THE EMBODIMENTS OF THE INVENTION TO WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A fumigating method comprising heating indirectly a mixture of an active ingredient and a blowing agent with a heating element to thermally decompose the blowing agent without entailing combustion and to volatilize the active ingredient, said blowing agent being decomposable at a temperature of between about 70°C and about 300°C to give off mainly nitrogen gas.

2. A method as defined in claim 1 wherein the heating element is formed of an exothermic substance capable of evolving heat on contact with water.

3. A method as defined in claim 2 wherein the exothermic substance is calcium oxide.

4. A method as defined in claim 1 wherein the heating element is means capable of evolving heat by application of an electric current.

5. A method as defined in claim 4 wherein the means is a heating wire, a heating carbon element or a thermistor of positive temperature coefficient.

6. A method as defined in claim 1 wherein the heating element is formed of an exothermic substance capable of evolving heat by contact with air.

7. A method as defined in claim 6 wherein the exothermic substance is a mixture of sodium sulfide and at least one of iron carbide and carbon black.

8. A fumigating method as defined in claim 1 wherein said blowing agent is at least one species selected from the group consisting of azodicarbonamide, benzenesulfonylhydrazide, p-toluenesulfonylhydrazide, p,p'-oxybis(benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, N,N'-dinitroso-N,N'-dimethyl-terephthalamide, trihydrazinotriazine, azobisisobutyronitrile, 4,4'-azobiscyanovaleric acid, t-butylazoformamide, 2,4-bis(azosulfonyl)toluene, 2,2'-azobisisobutyloamide, methyl-2,2'-azobisisobutyrate, 2-(carbamoylazo)isobutyronitrile and 1,1'-azobiscyclohexane-1-carbonitrile.

9. A fumigating method as defined in claim 8 wherein said blowing agent is at least one species selected from the group consisting of azodicarbonamide, p,p'-oxybis-(benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, azobisisobutyronitrile and 1,1'-azobiscyclohexane-1-carbonitrile.

10. A method as defined in claim 9 wherein the blowing agent is azodicarbonamide.

11. A method as defined in claim 1 wherein the active ingredient is an insecticide.

12. A method as defined in claim 1 wherein the active ingredient is a fungicide.

13. A fumigating apparatus comprising a container having at least one compartment accommodating a mixture of an active ingredient and a blowing agent which is decomposable at a temperature of between about 70°C and about 300°C to give off mainly nitrogen gas and at least one further compartment provided adjacent to said compartment and accommodating a heating element, the interior of the container being divided with a partition into said compartments, the partition providin a surface for transferring the heat evolved from said heating element to the mixture.

14. A fumigating apparatus as defined in claim 13 wherein the mixture accommodating compartment has an open upper end sealed with a meltable film.

15. A fumigating apparatus as defined in claim 13 wherein the heating element is formed of an exothermic substance capable of evolving heat on contact with water.

16. A fumigating apparatus as defined in claim 15 wherein the exothermic substance is calcium oxide.

17. A fumigating apparatus as defined in claim 15 wherein the compartment accommodating the exothermic substance is substantially closed.

18. A fumigating apparatus as defined in claim 17 wherein the closed compartment is provided with means for supplying water to the exothermic substance.

19. A fumigating apparatus as defined in claim 18 wherein the water supplying means is at least one water inlet aperture formed in an upper portion of the closed compartment.

20. A fumigating apparatus as defined in claim 19 wherein the closed compartment is provided with a water receptacle in its top portion, and the water inlet aperture is formed in the bottom of the water receptacle.

21. A fumigating apparatus as defined in claim 18 wherein the water supplying means is at least one water inlet aperture formed in a lower portion of the closed compartment.

22. A fumigating apparatus as defined in claim 18 wherein the water supplying means is a water reservoir provided within the closed compartment, and the water reservoir is provided with means for opening the reservoir from outside.

23. A fumigating apparatus as defined in claim 18 wherein the closed compartment is provided with an opening for maintaining the internal pressure of the closed compartment in balance with the outside pressure.

24. A fumigating apparatus as defined in claim 18 wherein a water-permeable layer is provided within the closed compartment to permit the water supplied from the water supplying means to pass through the layer into contact with the exothermic substance.

25. A fumigating apparatus as defined in claim 13 wherein the container is provided with means for attaching the apparatus to a vertical wall, column surface or ceiling.

26. A fumigating apparatus as defined in claim 18 wherein the container is provided with means for supplying a specified amount of water to the compartment accommodating the exothermic substance.

27. A fumigating apparatus as defined in claim 13 wherein the heating element is formed of an exothermic substance capable of evolving heat by contact with air.

28. A fumigating apparatus as defined in claim 27 wherein the exothermic substance is accommodated in a closed compartment having an opening sealed with an openable film of air-impervious material.

29. A fumigating apparatus as defined in claim 27 wherein the exothermic substance is a mixture of sodium sulfide and at least one of iron carbide and carbon black.

30. A fumigating apparatus as defined in claim 13 wherein the heating element is means capable of evolving heat by application of an electric current.

31. A fumigating apparatus as defined in claim 30 wherein the means is heating wire, a heating carbon element or a thermistor of positive temperature coefficient.

32. An apparatus as defined in claim 13 wherein said blowing agent is at least one species selected from the group consisting of azodicarbonamide, benzensulfonylhydrazide, p-toluenesulfonylhydrazide, p,p'-oxybis(benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, N,N'-dinitroso-N,N'dimethyl-terephthalamide, trihydrazinotriazine, azobisisobutyronitrile, 4,4'-azobiscyanovaleric acid, t-butylazoformamide, 2,4-bis(azosulfonyl)toluene, 2,2'-azobisisobutyloamide, methyl-2,2'-azobisisobutyrate, 2-(carbamoylazo)isobutyronitrile and 1,1'-azobiscyclohexane-1-carbonitrile.

33. An apparatus as defined in claim 32 wherein said blowing agent is at least one species selected from the group consisting of azodicarbonamide, p,p'-oxybis(benzenesulfonylhydrazide), dinitrosopentamethylenetetramine, azobisisobutyronitrile and 1,1'-azobiscyclohexane-1-carbonitrile.

34. A fumigating apparatus as defined in claim 33 wherein the blowing agent is azodicarbonamide.