AU614386B2 - Termite insecticide and method of manufacturing the same - Google Patents

Description

S F Ref: 99706 FORM 10 COMMONWEALTH OF A R I PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int Class Complete Specification Lodged: Accepted: Published: Priority: S Related Art: tt Name and Address of Applicant: Dainihon Jochugiku Co., Ltd.

4-11 Tosabori 1-chome Nishi-ku Osaka-shi Osaka 550 i JAPAN Address for Service: Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Complete Specification for the invention entitled: Termite Insecticide and Method of Manufacturing the Same The following statement is a full description of this invention, including the oest method of performing it known to me/us 5845/7 ABSTRACT OF THE DISCLOSURE A termite insecticide containing molybdenum and/or tungsten, obtained by impregnating a cellulosic substrate with a water-soluble salt of molybdic acid and a watersoluble salt of tungstic acid, and an inorganic acid or an inorganic salt in the form of an aqueous solution, thus producing in said cellulosic substrate 0 oa a molybdenum compound and/or a tungsten compound, o o a00 e the solubility of said compound or compounds to water at 20 °C sa or (a) 00* being 1 by weight or below, said water-soluble salt or salts (a) 00 0 and said compound or compounds being contained in a weight 00 o0 0 0 0 o ratio of 0 to 50 parts of to 50 to 100 parts of c) and a method of manufacturing the same.

0000 0 0 0 00 0 o o a 0 00 0 0 0 0 0 0 0 00 0000 0 t TERMITE INSECTICIDE AND METHOD OF MANUFACTURING THE SAME BACKGROUND OF THE INVENTION The present invention relates to a termite insecticide consisting of a cellulosic substrate containing molybdenum and/or tungsten and a method of manufacturing the same.

Recently, damage by wood consumption by insect pests such termites, teredines and lyctes is a serious problem.

To protect wood from said damage by the insect pests, it has been in practice to treat the wood with suitable pesticide. To this end, organochlorine pesticides such as chlordane and dieldrin as insecticide component are used.

These insecticide components, however, have problems in persistency, toxicity, stimulation and polution, and there is a demand for development of a less toxic insecticide.

Japanese Patent Laid-open Publication No. Sho 59- 82,309 (82,309/1984) discloses controlling of nitrogen-fixing S "e organisms by water-soluble compounds containging an element Sao00 selected from a group consisting of molybdenum and tungsten.

This finding is very useful insofar as it concerns wood vermin insecticides in that Molybdenum and tungsten are inexpensive; These elements are safer than chromium and like metals; These elements do not show toxicity' to other

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.4 insects than those of fixing nitrogen such as termites or teredines and hence have high selectivity; These elements provide the intended -ffect slowly and are hence not avoided by termites or the liker and These elements are stable in various forms.

However, when the water-soluble compounds are singly used, their effect as insecticide is not always sufficient.

From the above practical viewpoint, the inventors studied mixtures of molybdenum compounds and tungsten compounds to find that a mixture containing molybdenum and tungsten (65 to 35 to 85) provides a remarkable synergistic effect of insecticide. On the basis of the finding, Japanese Patent Application No. Sho 63-39,157 (39,157/1988) was filed.

t *fit The mechanism of the synergistic effect is unclear in many points, but it is thought to be due to a difference between molybdenum and tungsten with respect to a termite insecticidal a 0 0 S° mechanism.

S0 0o More specifically, as disclosed in Japanese Patent o Laid-open Publication No. Sho 59-82,309 (82,309/1984), tungsten compounds greatly contribute to an action of preventing the i (r nitrogen-fixing in consortismic protozoans in the termite's intestines, while regarding the main insecticidal mechanism of molybdenum compounds it is substantially confirmed to be due to accumulatio of oxides of these compounds in the body of the termite. It is presumed that these two effects synergistically -2 iLI_

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enhance the effect as insectide.

However, with a termite insecticide obtained by the conventional methods of manufacture, a method, in which a cellulosic substrate such as wood material is impregnated with a water-soluble salt of molybdic acid and that of tungstic acid and is then dried, molybdenum and tungsten are not sufficiently fixed in the cellulosic substrate. Therefore, when the insecticide is used outdoors, molybdenum and tungsten are liable to be removed by rainfall or the like, resulting in reduction of the insecticidal effect. It has been tried to mix powder of a S molybdenum compound and a tungsten compound, which are difficultly soluble to water, with the cellulosic substrate and then mold the mixture. In this case, the powder is distributed only over the surface of the cellulosic substrate, so that sufficient insecticidal effect can not be expected.

Actually, it is very important to fix molybdenum and Ct? tungsten uniformly to the cellulosic base. In addtion, it is t required to provide an insecticide, in which cellulosic substrate containing water-soluble compounds of molybdenum and tungsten as active ingredients is held in such a state that it is not readily removed by rainwater or the like.

Usually, such insecticide is provided in the form of pellets. A pellet insecticide, however, has problems in manufacture and in use such that it can be difficultly burried in the ground and it can be touched with the hand.

3 4 0 0n 0 0 0 000o 0 0000 0000 0 0 00 0 0 0 0 0 00 0 000 0000 0 0 0 0 0 00000 0 0 0 0 00 0 0 00 0 00 000 0 0000 0 0 0 00 0 4 SUMMARY OF THE INVENTION An object of the present invention is to provide a termite insecticide, in which a molybdenum compound and/or a tungsten compound is held uniformly in a cellulosic substrate, and which can effectively control termites.

Another object of the present invention is to provide a termite insecticide, which consists of a cellulosic substrate containing a molybdenum compound and/or a tungsten compound as active ingredients in such a state that it will not be readily removed by rainwater or the like.

A further object of the present invention is to provide a method of manufacturing a termite insecticide, in which a molybdenum compound and/or tungsten compound is or are uniformly held In a cellulosic substrate.

According to a first embodiment of the present 'nvention there is 15 provided a termite insecticide containing molybdenum and/or tungsten, obtained by impregnating a cellulosic substrate with a water-soluble salt of molybdic acid and/or a water-soluble salt of tungstic acid, and an inorganic acid selected from a group consisting of nitric acid, hydrochloric acid and sulfric acid or an inorganic salt selected from a group consisting of salts of alkaline earth metals, salts of aluminum family metals, salts of copper family metals and salts of iron family metals or mixtures of two or more thereof, in the form of an aqueous solution; which forms in said cellulosic substrate, 25 a molybdenum compound and/or a tungsten compound, the solubility of said compound or compounds to water at 20°C being 1% by weight or below, said water-soluble salt or salts and said compound or compounds being contained in a weight ratio of 0 to 50 parts of to 50 to 100 parts of According to a second mode of the present invention there is provided a termite insecticide comprising a cellulosic substrate containing a molybdenum compound and/or a tungsten compound and sealed in a package made of pulp.

According to a third mode of the present invention there is provided a method of manufacturing a termite inseci.cide by impregnating a cellulosic substrate with a water-soluble salt or molybdic acid and/or a water-soluble salt of tungstic acid, and

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Z LH/1599R I i 5 an inorganic acid or an inorganic salt in the form of an aqueous solution in the mentioned order such that is in an amount of more than 0.5 equivalents; which forms in said cellulosic substrate a molybdenum compound and/or a tungsten compound, the solubility of said compound or compounds to water at 20 0 C being 1% by weight or below, said water-soluble salt or salt and said compound or compounds being contained in a weight ratio of 0 to 50 parts of (a) to 50 to 100 parts of BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph showing the releasing with respect to insecticide 2, after accelerated weathering test Figure 2 is a perspective view insecticide using a box-like package 15 and mortality termites 20 days after samples Nos. 1, 3 and 5 in Example period; showing an embodiment of the according to the present invention; ,r r I ftr

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Figure 3 is a perspective view showing another embodiment of the insecticide using a bag-like package according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present inventors conducted researches and investigations in the light of the above affairs to develop a termite insecticide containing molybdenum and tungsten, which is capable of being excellently fixed in a cellulosic substrate and free from the danger of removal of molybdenum and tungsten in outdoor use and has a high insecticidal effect. As a result, they Sf o 1 a 0 4a a V il JLH/l599R found that a very useful termite insecticide can be obtained by impregnating a cellulosic substrate with a water-soluble salt of molybdic acid and/or a water-soluble salt of tungstic acid and adding an inorganic acia or an inorganic salt in an amount more than 0.5 equivalents relative to the salt of molybdic acid and/or salt of tungstic acid to convert 50 to 100 of the salt or salts to a molybdenum compound and/or tungsten compound with a water solublity at 20 °C of 1 by weight and slightly soluble to water in the cellulosic substrate. The present invention is predicated in this finding.

1 o0 V That is, the present invention is to provide a o composition containing molybdenum and/or tungsten for o. controlling termits in which cellulosic substrate contains a slightly water-soluble molybdenum compound and/or tungsten compound as active ingredient(s) at the amount corresponding to to 100 of the respective amount of molybdenum and tungsten 10 by the formation under the salt exchange.

D S 0 In the method ou' manufacturing a termite insecticide So o according to the present invention, an aqueous solution of a salt of molybdic acid and/or an aqueous solution of a sialt of tungstic c o! acid is or are impregnated uniformly in a cellulosic substrate, S a preferably a wood material, followed by said aqueous inorganic 0 00 acid or salt solution treatment to cause formation and precipitation of slightly water-soluble compound or compounds.

Thus, the fixing of molybdenum and/or tungsten permiates to the 6i insdie of the base at cellular structure level and is very firm.

Thus, the fixing of molybdenum and/or tungsten permiates to the inside of the substrate at cellular structure level and is very firm.

According to the present invention, the substrate may be first impregnated with either the water-soluble salt solution or a water-soluble solution of the inorganic acid or salt.

Preferably, the substrate is first impregnated with the former.

Examples of the water-soluble salts of molybdic and tungstic acids which can be used according to the invention are sodium molybdate ((Na MoO 39.4 (28 ammonium molybdate ((NH4)6Mo7 024 43 (25 potassium molybdate ('K2MoO 4 64.6 (25 magnesium molybdate ((MgMoO 4 15.9 (25 sodium tungstate ((Na 2

WO

4 57.6 (0 ammonium tungstate ((5(NH 4 2 0.

12WO 3 and potassium tungstate (K 2 W0 4 These examples are by no means limitative. The figures described after the chemical formulae represent water-solubilities (in g/100 ml) given in a S- litarature.

Examples of the inorganic acid and inorganic salt for rending the water-soluble salts noted above to be slightly watersoluble are: Inorganic acid: nitric acid, hydrochloric acid and sulfric acid Inorganic salt salts of alkaline earth metals such as calcium chloride, barium chloride and barium nitrate, salts of i-7i I aluminum family metals such as aluminum nitrate, salts of copper family metals such as silver nitrate and salts of iron family metals such as ferrous chloride, ferric chloride and cobalt chloride. As a result, it is possible to derive useful slightly water-soluble compounds of molybdates such as anhydrous molybdic acid ((MoO 3 0.049 (28 molybdic acid ((H 2 MoO 4 0.133 (18 calcium molybdate ((CaMoO 4 0.005 (25 ferrous molybdate ((FeMoO4' 0.0076 (25 barium molybdate ((BaMoO 4 0.0058 (25 silver molybdate and aluminum molybdate and 0a 0 tungstates such as anhydrous tungstic acid (WO3), tungstic acid ooo (H2WO calcium tungstate ((CaWO 4 0.0032 (25 ferrous 0 4 4 eOcO tungstate (FeWO 4 barium tungstate ((BaWO 4 0.001 (25 006 00 silver tungstate and aluminum tungstate.

0 0 qC The figures described after the chemical formulae oooo represent water solubilities (in g/100 ml) given in a 0 oo litarature.

0 So The method of manufacture of a termite insecticide 0 0 0 0000 according to the present invention will now be described in greater detail. A cellulosic substrate such as a wood material, 0 0oo 0 o paper, cardboard, preferably wood material, is impregnatd with a oo 0 0 00 0 o water-soluble salt of molybdic acid and/or a water-soluble salt of tungstic acid, preferably both of them, in a ratio of 65 to parts of molybdenum to 35 to 85 parts of tungsten and in a total amount corresponding to 0.5 to 20 of the cellulosic substrate by means of pouring (under increased or reduced pressure), 8 spraying or immersing, and, preferably after a drying step, an aqueous solution containing a suitable concentration of an inorganic acid and or an inorganic salt is added in an amount corresponding to 0.5 equivalent or above, preferably 0.5 to equivalent, the amount of the impregnated salt of molybdic acid and/or salt of tungstic acid by means of pouring (under increased or reduced pressure), spraying or immersing to cause formation and precipitation of slightly water-soluble molybdenum compound and tungsten compound in a cellulosic substrate. The cellulosic o 0 .o a substrate is then dried and, if necessary, molded to a desired oooo Sooo shape, thus obtaining a termite insecticide according to the present invention.

o0t The termite insecticide according to the present 0 invention is characterized in that it contains 50 to 100 of a 0o molybdenum and/or tungsten as insecticidal component in the form a 0 00 of slightly water-soluble compound or compounds obtained through 0 0 salt conversion, the remainder being water-soluble salt or 0 0 a 0 0 00.0 salts. It is well known that slightly water-soluble salts of molybdenum and tungsten, calcium salt and iron salt, have o oo00 0 o slow effects on termites compared to water-soluble salts. The 0o 0 a slightly water-soluble compound obtained by the method according to the present invention has comparatively fast effect and shows a behavior resembling that of water-soluble salts.

It is confirmed that mixing the slightly water-soluble compound and a water-soluble salt has an effect of 9 ~rrrr~-~-~pr~--rJI synergistically enhancing the initial activity-provision property and residual-activity property. Thus, there is no problem of loss of the active component i- uie, and it is possible to provide a useful termite insecticide, which has high initial effect and residual effect.

In order to provide the insecticidal effect efficiently, a termite inducer is suitably incorporated.

Examples of the termite inducer are rotted Serpula lacrymans and rotted Gloeophyllum trabeum. Further, rotted wood 0 o P pieces may be used after their suitable size adjustment. It is 0000 0 0 0::o further possible to add an extract from rotted wood piece to the oa o 000o insecticidal component.

0 0o a 000 00 oo Furthermore, it is possible to add to the termite 0 0 insecticide according to the present invention other 0oeo insecticides, for instance such organic phosphorus agents as 0 0 0 00 0 Sooo 0 chlorpyrifos, Phoxim and pyridaphenthion, such pyrethroid agents o oo as Permethrin, Fluvalinate, Fenvalerate and Fenpropathrin and D 0o such carbamate agents as tripropyl-isocyanulate or add synergists as "S-421" (octachloro dipropyl ether) piperonyl 00 00 S0o butoxide. Further, it is possible to incorporate various 00 0 U preservatives, for instance such CCA (chromium, copper, arsenic) compounds as CCA and CCB (chromium, copper, boron), such halophenol compounds as pentachlorophenyl laurate and p-bromo- 2,6-dichlorophenol, such iodopropargyl compound as "IF-1000" and 3-iodo-2-propynylbutylcarbamate, such quarternary ammonium 10 i :i ii" i s~ur compounds and amine salt as benzal konium chloride and dialkyldimethylammonium chloride, such organotin compounds as bis(n-tributyltin) oxide and tributyltin-terephthalate, zinc naphthenate and xylasan aluminum salt. In this way, various useful multi-purpose composition can be obtained.

The termite insecticide according to the present invention can be formulated by conventional method and may be provided in various forms such as tablets, pellets, plywoods and construction materials depending on its properties and purpose.

Particularly, the insecticide obtained by molding treated wood S*4 *a 1 chips with a press into a form of wood pieces is preferable, and

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if necessary, surface active agents and bonding agents or adhesives such as casein, gelatine, starch, CMC and polyvinyl alcohol can be used for information.

The termite insecticide according to the present invention is usually used by treating the earth under or surrounding the house or burrying treated pieces. Further, the 1 4 4 t insecticide may be incorporated in a paint to obtain an antitermite paint. Also, it may be usefully incorporated in antii II termite plywoods and construction materials.

Molyblenum and tungsten compounds usually have slow effect-acting property on termites compared to general insecticides and are free from repellent action. Therefore, the termite insecticide according to the invention can exterminate the entire nest by utilizing a phenomenon of glooming or 11 IIi devouring of termites taking it.

A second mode of the present invention concerns a termite insecticide, in which a cellulosic substrate containing molybdenum and/or tungsten is sealed in a package made of pulp.

According to the second mode of the present invention, molybdenum and/or tungsten to be contained in the cellulosic substrate may be a water-soluble compound or may consist of water-soluble compound or compounds and slightly water-soluble compound or compounds as described before in connection with the first mode of the present invention.

As a cellulosic substrate containing molybdenum and/or tungsten, it is preferable to use the substr-ate of the first mode of the present invention. However, in the second mode of the present invention, it is particularly meaningful to use a substrate containing water-soluble compound or compounds.

The termite insecticide according to the second mode of the present invention may directly use a substrate after drying. If necessary, it is possible to incorporate surface active agents or bonding agents or adhesives as casein, gelatine, o o00 Sstarch, CMC and polyvinyl alcohol, and an insecticide in a S' desired form such as tablets or pellets may be formulated.

The package may be made of materials such as chemical pulps such as kraft pulp, sulfite pulp and semi-chemical pulp or groundwood pulp or linter pulp. Particularly, pulps manufactured for the purposes of kraft paper, paper board and 12 cardboard provide strong paper strength and are suitable. The package made of pulp is free from repellent action by termites.

Therefore, when wood chips containing molybdenum and/or tungsten is sealed in the package and then burried in the earth, it proves a high anti-termite activity effect just as it is burried in the earth without be.. g packed. Besides, it is possible tc prevent leaking of molybdenum and/or tungsten due to rain or like causes.

Therefore, it is possible to use water-soluble salts.

While box-like and bag-like package are illustrated, 0 00 0 these shapes are by no means limitative. Further, the package 0 0 0000.. may be provided with a grip or a tug of other materials such as 0 plastic materials so far as such materials do not provide repellent action by termites. Further, to obtain the insecticidal effect more effici.ently, it is possible to incorporate a termite inducer.

As the termite inducer may be used the rotted wood materials as noted above. In this case, it is possible to adjust r t I the rotted wood materials to a suitable size or to obtain extract from the rotted wood materials so as to be added to the cellulosic substrate or the package as a separate content of thereof.

The termite insecticide according to the second mode of the present invention may be easily burried in the earth generally at a depth of 20 to 50 cm in the neighborhood of a house or termite's nest without touching any chemical for controlling termites.

13 13 With the termite insecticide according to the second mode of the present invention, in which the cellulosic substrate is sealed in the package, it is possible to prevent the leaching of molybldenum and/or tungsten from the substrate in practical use. This means that it is possible to dispense with a process of rendering the active component insoluble to water in the manufacture, which is very beneficial in economy.

Test Examples and Examples Test examples and examples concerning the present invention are given below without any sense of limiting the o 0° present invention.

i rr Test Example 1 1 ml of an aqueous solution containing 3.15 of sodium molybdate and 6.73 of sodium tungstate was poured using a pipet onto a pine piece of 1 x 1 x 2 cm. After drying, the treated wood pieces were divided into three groups. 1 ml of 3.7 calcium 00 chloride aqueous solution and 1 ml of 1.9 calcium chloride aqueous solution were poured using a pippet onto the wood pieces of the respective first and second groups to form calcium salt of 0 it molybdenum and that of tungsten. No treatment for producing a slightly water-soluble salt was done for the third group. After each sample was dried, said each sample was immersed in water in a beaker for 2 days, and the quantities of molybdenum and tungsten leached in water (elution rate) were determined by a 14 method prescribed in JIS G 1218. The results are as shown in Table 1.

Table 1 Group 1 2 Amount of calcium chloride 1.0 equivalent 0.5 equivalent Elution rate after 2 days Molybdenum Tungsten

S

25i Inseticide of the Invention Control insecticide 2' art A S As a result of the test, it was confirmed that sodium molybdate and sodium tungstate, both being water-soluble, can be converted by treatment with calcium chloride aqueous solution into calcium molybdate calcium tungstate, both being slightly water-soluble, thus extremely reducing the leaching of molybdenum and tungsten by elution in water.

Test Example 2 1 ml of an aqueous solution containing 3.15 of sodium molybdate and 6.73 of sodium tungstate was poured onto a pine piece of 1 x 1 x 2 cm. Then, slightly water-soluble compounds 15 were formed by the treatment with aqueous solution containing various equivalent of calcium chloride.

To examine influence of leaching of the active ingredient by assumed rainfall on the insecticidal effect, an accelerated weathering treatment of holding sample wood pieces in water for 30 minutes was performed once for every 3 days, and samples after 2 weeks, one month and three months of the accelerated weathering period were used for insecticidal test.

Each sample was put on the bottom of a deep dish, and 0 0o .o 0 20 termites of Formosan subterranean termite (Coptotermes 0ooo 0 0° formosanus) were released into the dish, and they were grown by closing the dish with a lid and under conditions of 25 1 °C and or above RH (Relative humidity). The mortality and degree of wood pieces attack (weight reduction) were examined at a p:redetermined interval. The results are shown in Table 2.

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I 3O Table 2 Composition of sample Amount of calcium chloride Watersoluble salt Slightly water-soluble compound Accelerated Weathering test Mortality After 10 days After 20 days Weight reduction after 20 days No. 1 1.0 equivalent Insecticide of the Invention 100 No. 2 0.75 equivalent No. 3 0.5 equivalent No. 4 0.25 equivalent No. 5 95 95 90 100 95 100 100 100 90 75 100 85 1.2 0.9 1.1 0.8 0.7 0.6 0.7 1.6 3.3 0.4 3.8 2.4 2.9 Contrast insecticide 100 No. 6 Commercially available product 100* produced by mixing powdery calcium molybdate with the resultant material with a press Note.: W means week and M means month wood chips and then molding i 1. r 1 I f I~ I I I I II I I I II As is seen from the results of the Test Example, the termite insecticides according to the present invention, containing 50 to 100 of calcium molybdate and calcium tugnstate obtained by treading sodium molybdate and sodium tungstate with calcium chloride, showed high insecticidal effect and effect for the prevention of wood-eating damage regardles of the accelerated weathering test period. On the other hand, with the control termite insecticides (samples No. 4 and No. 5) with high water-soluble salt contents, the insecticidal effect quickly reduced with the accelerated weathering test period, and influence of the leaching of the active ingredient by elution on the insecticidal effect in practical use was apprehended.

The commercially available product (sample No. 6) prepared by using calcium molybdate had problems in the aspect of physical properties of the product and insecticidal effect.

Thus, the usefulness of the method of manufacture according to the present invention was proved.

Further, a synergistic effect of reinforcement of the initial and residual insecticidal activities could recognized by mixing water-soluble and slightly water-soluble salts.

Example 1 100 m of an aqueous solution containing 3.15 of sodium molybdate and 6.73 of sodium tungstate was sprayed using a hand spray over 100 g of wood chips. Then, after air-drying the wood chips for 2 days, 100 ml of 2.5 calcium chloride aqueous 7U 2 18 1 solution was sprayed over the wood chips. Then, after air-drying for 2 days, a solution obtained by dissolving 7.2 g of isocyanate adhesive in 30 cc of acetone was added to 72 g of the treated wood chips. The resulting system was then intimately mixed and molded using a bench press, and the molding was then cut to a size of 1 x 2 x 2 cm, thus obtaining a termite insecticide bait. These bait 2 pieces were arranged at a rate of 10 pieces per m in the ground under and surrounding a house. By so doing, it was possible to prevent damage to the house by termites for over 2 years and S 00 o0 ,o eventually exterminate the entire nests of termites through 6000 devouring thereof.

0oo00 .o0 On the other hand, with a control bait solely 0 0 0 0 a" containing sodium molybdate and sodium tungstate it was 00 40 0 t impossible to esterminate the entire termite's nests, but the house was partly damaged from a time after the passage of a half o0 o Syear from the application of the bait.

0 oo 0 00 Example 2 0 00 a 0 According to the Example 1, 15 ml of an aqueous solution containing 2.8 of potassilim molybdate and 4 of S0oo benzalconium chloride was mixed with 10 g of I-cellulose, and 0 4 Sat then 15 ml of 2.0 of barium chloride aqueous solution was sprayed. The resulting mixture was molded to obtain a bait in the form of pellets.

such pellets were disposed together with a bait wood piece at each of six places surrounding outdoor nests of Formosan 19

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-I subterranean termite (Coptotermes formosanus), and the status of the bait wood and nests was observed for every one month. Damage to the bait wood (damage by wood consumption) was reduced sharply from a time after two months from the disposition, indicating the dulling of the activity of the nests.

Similarly high insecticidal effects could be obtained with a termite insecticide containing ammonium molybdate and ammonium tugstate as well as molybdic acid and tungstic acid obtained by a treatment with nitric acid. However, control baits containing barium phosphate and barium borate could not control damage to the bait wood (damage by wood consumption).

Example 3 An aqeuous solution containing ammonium molybdate and ammonium tungstate was injected into a lauan plate with a thickness of 0.7 mm and a water content of 14 to 15 such that rt of molybdenum and 2.0 of tungsten were contained per weitht of the plate.

After drying, 100 of molybdenum and tungsten was converted to barium molybdate and barium tungstate by injecting S barium chloride aqueous solution. Then, the produced ammonium it chloride was removed by water washing, and the resulting plate was dried. The plate obtained in this way was overlapped over each side of a lauan plate with a thickness of 1.4 mm and a water content of 10 and the resulting plate was compressed at normal temperature and under a pressure of 10 kg/cm 2 for 20 minutes. The 20 .rr ~--xlrrrsra~--~~ plate was then inserted in a hot press at a temperature of 120 °C and pressed with a pressure of 9 kg/cm for one minute to obtain a laminated plate.

This laminated plate was used for a termitecontrolling test and showed a high control prevention effect even after lapse of one year.

The termite insecticide according to the first mode of the present invention contains les water-soluble compounds compared to the conventional termite insecticides, so that it has o 00 o 0 excellent safety, insecticidal effect and effect of prevention o 0 .000 of leaching of active ingredient and is a very useful °°00 insecticide.

oo 0 0 oo9 Examples 4 and 0 0 Figs. 2 and 3 are views illustrating embodiments of the 00 0 second mode of the present invention. In the Figures, reference 0o0 o 0 numeral 1 is a chemical-treated cellulosic substrate, and 2 is a package made of pulp.

0 0 .00 In the embodiment shown in Fig. 2, the package 2 is box-type. The package 2 may be formed with a thick paper sheet 00 09 0° 0° such as a cardboard.

a o' In the embodiment of Fig. 3, the package 2 is bag-like.

In this case, the package 2 may be made of paper, which may be single-layer paper or a laminated paper sheet. In the case of using laminated paper, it is recommendable to use paper impregnated with the termite insecticide for the inner side of 21 I -i i the package.

As the cellulosic substrate 1 containing molybdenum and tungsten was used one, which is obtained by impregnating a cellulosic substrate such as wood material such as wood piece, or paper, preferably Japanese red pine chips with a water-soluble salt of molybdic acid and a water-soluble salt of tungstic acid in a ratio of 65 to 15 parts of molybdenum to 35 to 85 parts of tungsten, followed by drying. As the first mode of the present invention, the chemical in Test Example 1 was used.

a 04 oo o0 The chemicals of Examples 4 and 5 were disposed in the 0000oo earth in the same manner as in Example 1. It was shown as a result 0 0 that in either case of Examples 4 and 5 either chemical-treated 0 0 substrate showed the same effect as in the Example 1 without a i being influenced by the package 2.

o o o 00 0 0 0 0 t 22

Claims (7)

1. 2. A method of manufacturing a termite insecticide by impregnating a cellulosic substrate with a water-soluble salt or molybdic acid and/or a water-soluble 20 salt of tungstic acid, and an inorganic acid selected from a group consisting of nitric acid, hydrochloric acid and sulfric acid or an inorganic salt selected S from a group consisting of salts of alkaline earth metals, salts of aluminum family metals, salts of copper family metals and salts of iron family metals or mixtures of two or more thereof, in the form of an otooo aqueous solution in the mentioned order such that is in an amount a...aa of more than 0.5 equivalents; which forms in said cellulosic substrate a molybdenum compound and/or a tungsten compound, the solubility of said compound or compounds to water at 20°C being 1% by weight or below, said water-soluble salt or salt and said compound or compounds being contained in a weight ratio of 0 to 50 parts of (a) to 50 to 100 parts of
2. 3. A termite insecticide as claimed in claim 1, wherein said cellulosic substrate containing molybdenum and/or tungsten is sealed in a package made of pulp.
3. 4. The termite insecticide as claimed in claim 3, wherein molybdenum and/or tungsten are/is contained in the form of a <L u\ water-soluble compound of molybdenum and/or a water-soluble compound of JLH/369U 1 -L I I' 24 tungsten. A termite insecticide substantially as herein described with reference to Test Example 1 and Group 1 or 2, Test Example 2 and any one of insecticides 1 to 4, or any one of Examples 1 to 3.
4. 6. A termite insecticide comprising a cellulosic substrate substantially as herein described with reference to Example 4 and Fig. 2 together with an insecticide as defined in claim 6 or Example 5 and Fig. 3 together with an insecticide as defined in claim 6.
5. 7. A method of manufacturing a termite insecticide substantially as hereinbefore described with reference to Test Examples 1 or 2.
6. 8. A termite insecticide when prepared by the method as claimed in claim 2 or 7.
7. 9. A method of controlling termites at a locus comprising applying to the locus an effective amount of a termite insecticide as claimed in any one of claims 1, 3 to 6 or 8. o F It DATED this SIXTH day of JUNE 1991 Dainihon Jochugiku Co., Ltd Patent Attorneys for the Applicant SPRUSON FERGUSON 00000~ 3'Vrc;,' .JLH/369U I