Patent GB-717610-A (GB)
Title: Means for the safe storing and handling of highly toxic pesticides
Inventor: HARTLEY GILBERT SPENCER
IPC: C07F9/22
Filed: 1952-03-05
Abstract: A pesticidal agent in a form adapted for handling and storage comprises a closed capsule of a cellulose derivative which contains free carboxyl groups (see Group VI), the said capsule containing a systemic pesticide capable of being taken up by the roots of a plant and containing also, if desired, a plant growth assistant such as (a) fertilizers e.g. ammonium nitrate, potassium nitrate and ammonium phosphate and (b) trace element compounds such as manganese sulphate. Systemic insecticides which tend to dissolve the cellulose acetate phthalates of the capsule may be dissolved in a non solvent for the capsule.  Specified systemic insecticides are (a) compounds of the formula <FORM:0717610/I/1> wherein R1, R2, R3 and R4 each represent an alkyl or cycloalkyl group containing not more then 8 C atoms, whilst alternatively R1 and R3 may each represent hydrogen and where X is fluorine or the azido group N3 e.g. dimethylamino isopropylamine azidophosphine oxide; the compounds of the formula <FORM:0717610/I/2> wherein R1, R2, R3, and R4 have the meanings above e.g. bis-dimethylamino phosphoros anhydride; and (c) compounds of formula <FORM:0717610/I/3> wherein R1 and R2 each represent an alkyl chain which may be interrupted by one or more sulphur or oxygen atoms e.g. diethyl methyl mercaptoethyl thiophosphate.  The Provisional Specification refers to Specifications 526,276 and 702,607, [both in Group VI].ALSO:A pesticidal agent in a form adapted for handling and storage comprises a closed capsule of a cellulose derivative which contains free carboxyl groups, the said capsule containing a systemic pesticide capable of being taken up by the roots of a plant and containing also, if desired, a plant growth assistant such as (a) fertilizers, e.g. ammonium nitrate, potassium nitrate and ammonium phosphate, (b) trace elements, e.g. manganese sulphate.  The cellulose derivative may be an ester or ester-ether and may contain both dicarboxylic aliphatic or aromatic acid radicals and also monobasic fatty acid radicals.  They preferably contain 5 to 20 per cent free carboxyl.  Examples are (a) cellulose-acetate-phthalates of 12 per cent free carboxyl in which of the six hydroxyl groups available in the C12 unit, three are converted to acetate and two to the half phthalate, i.e. only one of the carboxyl groups of the phthalic acid is esterified; (b) cellulose-acetate-butyrate-phthalate containing per C12 unit, two of acetate, two of butyrate and one of the half-phthalate.  Systemic insecticides which tend to dissolve the cellulose acetate phthalates may be dissolved in a non-solvent for the capsule material, e.g. benzene, homologues thereof and glycerin, or all or part of the acetate, may be replaced by other monobasic fatty acid residues, e.g. propionic or butyric acid residues. Specified systemic insecticides are (a) compounds of general formula: <FORM:0717610/VI/1> Where R1, R2, R3 and R4 each represent an alkyl or cycloalkyl group containing not more than eight carbon atoms, whilst alternatively R1 and R3 may each represent a hydrogen atom, and where X is fluorine or the azido group N3, e.g. bis-dimethylamino fluorophosphine oxide, bis-dimethylamino azidophosphine oxide, dimethylamino-isopropyllamino fluorophosphine oxide, dimethylamino isopropylamino azidophosphine oxide; (b) compounds of general formula:  <FORM:0717610/VI/2> wherein R1, R2, R3 and R4 have the meanings above, e.g. bis-dimethylamino phosphonous anhydride; (c) compounds of general formula:  <FORM:0717610/VI/3> wherein R1 and R2 each represent an alkyl chain which may be interrupted by one or more sulphur or oxygen atoms, e.g. diethyl methylmercaptoethyl thiophosphate or diethyl ethylmercaptoethyl thiophosphate.  The Provisional Specification refers to Specifications 526,276 and 702,607.