| 摘要 |
1359136 Pesticidal formulations SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 6 Oct 1971 [8 Oct 1970] 47905/70 Heading A5E The invention comprises a pesticidal article which comprises a volatile pesticidally active phosphorus ester of the formula wherein R 1 and R 2 each represents an alkyl group; X represents an oxygen or sulphur atom; and Y represents an optionally substituted ethyl, vinyl, 1,2,5-thiadiazole or 1,2,5- oxadiazole group together with an involatile polyhydric phenol, the weight ratio ester phenol being in the range 1:1 to 9:1 and an outer layer which wholly or partially covers the active composition, has a thickness of up to 100 Ám and is formed from a material which is permeable to the phosphorus ester. The phosphorus ester preferably has a vapour pressure of at least 10<SP>-3</SP>mn Hg at 20‹C. Suitable esters include dimethyl-(2,2-dichlorovinyl) phosphate, is thiomo analogue and dimethyl - (1,2,5 - thiadiazol - 3 - yl) phosphorothioate. Polyhydric phenols which may be employed include quinol and resorcinol. The active composition may be adsorbed on an inert carrier, e.g. a cellulose ester, cellulose containing material and absorbent paper. The carrier may form up to 60% by weight of the total weight of the combined active composition and carrier. The outer layer may be in the form of a surface coating or a preformed membrane covering one or more surfaces of the active composition. The thickness of the surface coating may be between 10-50 Ám. Such a layer may be formed of a synthetic polymeric material, e.g. a thermoplastic rubber, a polymide. plasticised polyvinyl chloride or a copolymer of ethylene with other olefininc compounds. Also a method of combatting anthropod pests at a locus comprises exposing the locus to a pesticidally effective amount of a phosphorous ester released from a pesticidal article as above. |
