IL47160A - Surface coating compositions containing insecticides - Google Patents

Abstract

1447305 Insecticide-containing coating compositions IMPERIAL CHEMICAL INDUSTRIES Ltd 15 April 1975 [29 April 1974] 18614/74 Headings C3B C3P C3F and C3R A paint or coating composition comprises, as insecticide (I), primiphos-(methyl or ethyl), i.e. O,O-di(methyl or ethyl)-O-2-diethylamino- 4 - methylpyrimidin - 6 - yl phosphorothionate. (I) may be microencapsulated in polyurea or polyamide, e.g. by interfacially condensing, in the presence of (I), a mixture of ethylene diamine and diethylene triamine with TDI or adipoyl chloride. An emulsifiable concentrate may be made by mixing (I), epichlorohydrin, Na dodecylbenzenesulphonate, (nonyl phenol)/ (ethylene oxide) condensate, and alkyl benzenes. Binders include (vinyl acetate)/(ethyl acrylate) copolymers, nitrocellulose, polyurethane, vinyl acetate polymer emulsion paint or drying-oilmodified alkyd gloss paint. [GB1447305A]

Description

SURFACE COATING COMPOSITIONS CONTAINING INSECTICIDES This invention relates to surface coating compositions which incorporate insecticides.

Although it has previously been proposed to incorpora e insecticidal substances in paints and similar surface coating compositions, these proposals have not always been satisfactory when put into practise. Chlorinated hydrocarbon insecticides which may have the required persistence are now considered to be environmentally unacceptable. When other active ingredients such as organophosphorus compounds have been used they are not sufficiently stable or persistant, and the insecticidal effect does not persist for a long enough period after the paint has been applied. In the Annual Report of the Danish Pest Infestation Laborator for 1972 (page 19) it is reported that paints incorporating 0,0,0' ,Ο'-tetramethy1 0,0 ' -thiodi-p_-phenylene phosphorothioate were ineffective in controlling mosquitos, and that those containing fenitrothion or dimethoate were active 6 days after application. However to be really useful the insecticidal effect must persist for several weeks and preferably for several months.

We have now discovered that certain organophosphorus insecticides are in fact very useful for incorporation in surface coating compositions, and such compositions possess advantages over those previously proposed.

According to the present invention a surface coating composition comprises as an insecticidal ingredient either pirimiphos-methyl or pirimiphos-ethyl .

Pirimiphos-methyl is the ISO recommended common name for 0 ,0-dimethyl 0-2-diethylamino-4-methylpyrimidin-6-yl phosphorothionate, and pirimiphos-ethyl is the ISO recommended common name for 0,0-diethyl 0-2-diethylamino-4-methylpyrimidin-6-yl phosphorothionate. They are also known by the Registered Trade Marks 'Actellic' and 'Primicid' respectively.

By the term "surface coating composition" we intend any paint, distemper, colour wash (including whitewash) , varnish or lacquer composition (but not including printing ink compositions) which is adapted to be applied by brushing, rolling or spraying on to a surface to protect or colour the surface. Such compositions may contain any of the conventional constituents of surface coating compositions such as pigments, fillers, solvents, extenders, polymers (for example, alkyd resins, epoxy resins, and the like) , diluents, drying oils, and the like, as well as the insecticidal components. Where a paint is concerned it may be an aqueous or non-aqueous paint, such as, for example, an emulsion based paint,or a gloss paint based upon a solvent such as white spirit.

Pirimiphos-methyl is a preferred insecticidal agent for use in the surface coating compositions of this invention because of its low toxicity to mammals. Hence the surface coating compositions comprising it may be safely used in domestic dwellings and public buildings, and for public health uses, for example in kitchens, food stores and hospitals. They may be used additionally for the treatment of farm buildings, animal houses and grain silos, and for treating the interior surfaces of the holds of ships.

In a preferred aspect of the invention the insecticidal component is added to the composition in a microencapsulated form, in which the capsule coat is, for example, a cross linked or non-cross linked polyamide or polyurea.

The invention compositions may comprise from 0.2% to 7.5% by weight of the insecticidal component, and preferably from 0.75% to 5.0% by weight.

The invention compositions may be prepared in any conventional manner with the insecticidal component being added at any convenient stage during the process of preparation.

Thus in the case of an oil based paint, a varnish or lacquer composition the insecticidal ingredient may be mixed into the otherwise completed composition. In such cases the insecticidal ingredient may be added in an undiluted form or it may be added as a solution in a suitable solvent.

In the case of an emulsion based paint the insecticidal component is usually dispersed in an aqueous phase, for example an aqueous dispersion comprising say 25% or 50% w/v of the insecticidal component, and this is then added to the mill base mixed together with the polymer latex dispersion, or it may be added to the whole paint after the polymer latex has been mixed with the mill base.

The following examples illustrate the invention.

EXAMPLE 1 An emulsion paint composition is prepared in the usual way by forming a mill base by grinding together pigment, water and a small amount of a dispersing agent in a colloid mill, and thereafter adding to the mill base a polyvinylacetate/ethyl acrylate copolymer latex dispersion in water the whole being blended in a colloid mill. To this mixture is then added a 20% w/v suspension of microencapsulated pirimiphos-methyl, in which the capsules are coated with polyamide obtained from the condensation of adipoyl chloride and a mixture of ethylene diamine and diethylenetriamine by an interfacial process, the addition being at a rate to give 5.0% w/w pirimiphos-methyl in the composition.

After a further period of blending to disperse the pirimiphos-methyl throughout the composition there is obtained an emulsion paint composition suitable for use on prepared plaster walls.

EXAMPLE 2 Pirimiphos-methyl is added to a nitrocellulose based lacquer composition to give a concentration of 2% by weight of the insecticide in the lacquer.

EXAMPLE 3 Pirimiphos-methyl is mixed with a polyurethane based clear varnish composition to give a concentration of 0.8% w/w of the insecticide in the varnish.

EXAMPLE 4 This example illustrates the preparation of an insecticidal emulsion paint.

A 50% emulsifiable concentrate of the insecticide was prepared by mixing together the following constituents in the proportions stated.

Pirimiphos-methyl 50.0% w/v Epichlorohydrin 2.0% w/v "Arylan" CA 5.0% w/v "Lubrol" N.13 5.0% w/v "Aromasol" H 100.0% w/v "Arylan", "Lubrol" and "Aromasol" are Registered Trade Marks. "Arylan" CA is sodium dodecylbenzenesulphonate, "Lubrol" N.B. is a condensate of nonyl phenol with ethylene oxide, and "Aromasol" H is a mixture of alkyl benzenes.

The emulsifiable concentrate was then thoroughly mixed with "Dulux" white matt emulsion paint to give an emulsion paint containing 3.2% w/w of pirimiphos-methyl. "Dulux" is a Registered Trade Mark.

EXAMPLE 5 This example illustrates the preparation of an insecticidal emulsion paint incorporating microencapsulated primiphos-methyl .

An aqueous suspension containing 20% w/v of microencapsulated pirimiphos-methyl was obtained by the interfacial condensation of a mixture of ethylene diamine and diethylene triamine, with a mixture of 1,3- and 1,4-toluene diisocyanate in the presence of pirimiphos methyl. This was added to "Dulux" white matt emulsion paint at a rate which gave an emulsion paint containing 3.2% w/w of pirimiphos-methyl.

EXAMPLE 6 An insecticidal emuslion paint was prepared as in the previous example but prior to mixing in the microcapsules they were separated from the medium in which they were prepared by centrifugation and dispersed in distilled water to give an emulsion paint containing 3.2% w/w of pirimiphos-methyl.

EXAMPLE 7 This example illustrated the preparation of an insecticidal gloss paint. Pirimiphos-methyl (technical grade) was added to "Dulux" white gloss paint at a rate which gave an insecticidal gloss paint containing 3.2% w/w of pirimiphos methyl.

EXAMPLE 8 This example compares the insecticidal properties of various paint formulations incorporating pirimiphos -methyl with similar formulations incorporating fenitrothion.

The various formulations used are set out as follows: A. Emulsion paint containing pirimiphos-methyl prepared by the method of Example 4.

B. Emulsion paint containing pirimiphos-methyl prepared by the method of Example 5.

C. Gloss paint containing pirimiphos-methyl prepared by the method of Example 7.

D. Emulsion paint containing fenitrothion prepared by the method of Example 4 but using fenitrothion in place of pirimiphos-methyl.

E. Gloss paint containing fenitrothion prepared by the method of Example 7 but using fenitrothion (technical grade) in place of pirimiphos-methyl .

F. Emulsion paint containing pirimiphos-methyl prepared by the method of Example 6.

G. Untreated emulsion paint.

H. Untreated gloss paint.

Formulations A to E were tested at the following dilutions of insecticidal component: 0.1%. 0.2%, 0.4%, 0.8%, 1.6% and 3.2%.

The test was conducted as follows. Single films of all paints, irrespective of formulation, were applied to plywood plaques (10 cm x 10 cm) . Six days after painting the plaques were bioassayed with female organophosphorus-susceptible houseflies, using two or three replicates for each dilution. In each case the flies were caged over the painted surface and the knock-down or kill of the flies assessed at intervals over a two hour period.

The results are set out in Table 1 below.

Assuming that the paint films were 0.001 inch (0.0254 mm) thick then the deposits of pirimiphos-methyl or fenitrothion from the various dilutions were as follows :- 0.1% 26 mg/m 0.2% 52 mg/m' 0.4% 104 mg/m* 0.8% 208 mg/m* 1.6% 416 mg/m'' 3.2% 832 mg/m' TABLE 1 TABLE 1 (continued) TABLE 1 (continued) Comparisons of the results obtained for formulations A and D and also for formulations C and E show that a superior insecticidal effect is shown by pirimiphos-methyl in both emulsion and gloss paints giving a faster rate of knock down and kill of houseflies than fenitrothion. It should also be noted that pirimiphos-methyl is active at lower rates of application than is fenitrothion.

EXAMPLE 9 This example illustrates the persistance of the insecticidal properties of paint films incorporating pirimiphos-methyl. The technique used was as follows: Miniature rooms were prepared from plywood, these being in the form of 12 inch (approximately 30 cm) cubes. Four 1 inch (2.54 cm) diameter holes were cut in the ceilings for ventilation and before the commencement of the tests these were covered with fine-mesh polyester netting. The rooms were painted with the formulation under test in one of two ways. Either two sides and the ceiling (2SC) were painted with a single coat, or a simulated miniature door, window frame and skirting board (MR) .

Three formulation types were tested, an emulsion paint, a gloss paint (each prepared as for the previous example except that they contained 5.0% ww of pirimiphos-methyl), and an epoxy resin paint.

This latter was prepared by mixing in technical pirimiphos-meth 1 to the epoxy base before the addition of the activator solution. In each case a comparison was made with rooms painted with the corresponding paint formulation without any insecticidal ingredient (control), and each treatment was assessed as the mean of two replicates.

Houseflies and cockroaches were introduced into the rooms at various intervals after painting and the mortality assessed after 24 hours, and additionally in some cases after 2 hours. The results, which are given in Tables 2 and 3 demonstrate that the insecticidal effect of paints incorporating pirimiphos -methyl persists for at least seven months.

TABLE 2 Age of % mortality of houseflies after exposure f painted surface Gloss paint Emulsion paint 2SC MR Control 2SC Control 1 day 100 100 5 100 8 1 week 100 100 0 lOO 0 3 weeks 100 100 3 100 10 5 weeks 100 100 10 100 15 7 weeks 100 100 - 100 - 9 weeks 100 100 15 100 5 1 weeks 100 100 20 100 8 3 weeks 100 100 33 100 23 6 weeks 100 100 23 100 23 TABLE 3

Claims (11)

1. A surface coating composition as hereinbefore defined incorporating as an insecticidal ingredient pirimiphos-methyl or pirimiphos-ethyl.

2. A paint composition incorporating pirimiphos-methyl.

3. A composition as claimed in Claim 1 or Claim 2 wherein the insecticidal component is in a microencapsulated form.

4. A composition as claimed in Claim 3 in which the capsule coat is a cross-linked or non-cross-linked polyamide or polyurea.

5. A composition as claimed in any of Claims 1 to 4 comprising from 0.2% to 7.5% by weight of the insecticidal component.

6. A composition as claimed in Claim 5 comprising from 0.75% to 5.0% by weight of the insecticidal component.

7. An emulsion paint comprising pirimiphos-methyl in a microencapsulated form in which the capsule coat is a non-cross linked polyamide derived from adipoyl chloride and a mixture of ethylene diamine and diethylene triamine.

8. An emulsion paint comprising pirimiphos-methyl in a microencapsulated form in which the capsule coat is a non-cross linked polyurea derived from toluene diisocyanate and a mixture of ethylene diamine and diethylene triamine,

9. A gloss paint comprising pirimiphos-methyl.

10. An epoxy resin paint comprising pirimiphos-methyl

11. Surface coating compositions as claimed in Claim 1 substantially as descri reference to any of the 11.4.75 NDB/SG