IL34004A - Method of combating aquatic parasites and a coating composition containing cuprous alkyldithiocarbamate or alkylene bis-dithiocarbamate salt for use in the method - Google Patents

Description

METHOD OF COMBATTING AQUATIC PARASITES AND A COATING COMPOSITION CONTAINING CUPROUS OR SALT FOR USE IN THE METHOD The present invention relates to a method of combatting aquatic parasites and to an composition for use in the It is known that all objects under seawater are subject to fouling due to the proliferation of marine especially molluscs and Civil engineering works such as port lock stations and treatment installations are overrun by deposits due to numerous marine organisms which are very difficult to The harmful action of the various aquatic parasites is particularly critical on cellulosic materials such as thus a heavy crust forms on hulls of which resists the smooth gliding of the keel through the and causes a reduction in speed which can sometimes be as much as Examples of the parasites which can be responsible for the above disadvantages are for example stone xylophages and crustaceans for example Chelura and and algae for example Bruozoa and In order to overcome these it is usual in the shipping industry to protect the keels of ships by several layers of coatings which generally consist a wash an coating and then an paint containing substances are toxic towards marine Of the toxic substances usually copper compounds are most Cuprous oxide is in practice recommended as one of the most efficient constituents the above It has now been found that if the conventional copper compounds in these paints are replaced cuprous or the copper content in the fouling paints can be much lower down to than that required cuprous oxide is The above cuprous carbamates can be obtained by while an alkali metal dithiocarbamate with cuprous chloride in an aqueous alkali The carbamates can be employed in conjunction with other metal alkyldithiocarbamates or for those of nickel and The cuprous carbamate can be either mixed with the other metal for example by or can be deposited on granules of the latter in the form of a these processes and the products thereof are disclosed in Israeli Patent Application The invention therefore provides a method of combatting aquatic the method comprisin to the habitat of the a cuprous salt which is cuprous alkyldithiocarbamate or The invention also provides an composition comprising above cuprous salts and at least ingredient conventionally used in fouling compositions suitably containing 25 of the It has already been proposed to use metal thiocarbamates containing copper in marine However the copper in these compositions has always been in the cupric form for DDR Specification The cupric called in the alkyldithocarbamates or alkyiene have very much lower chemical stability and heat stability than the corresponding cuprous their pigment properties and their resistance to ultraviolet rays are mediocre compared with those of the cuprous they are diff cult to disperse in the components the solvents usually employed in the formulation of paints and The compositions of the on the other possess all the igment properties generally desired for paint formulations for steel or other substrates to be protected against parasitic The cuprous carbamates can be obtained according to known processes in the form of fine powders of uniform particle which improves their penetrating power in ligneous Furthermore they are very stable to atmospheric agents and are in particular resistant to they depending on the nature the relative proportions of the metals which they provide wide range of varying from to which shades are not affected even if accidental partial sedimentation of the pigment the cuprous dithiocarbamates which are obtained in situ during the preparation of the well known dithiocarbamates of zinc manganese and iron are very stable and non even when exposed to high as Israeli has already been shown in application mentioned It also be mentioned that we have already proposed the use of a cuprous salt of a dithiocarbamic acid as a fungicide French Specification one skilled in the art will appreciatetthat there is no reason at all why a substance which is a fungicide be effective against marine our French indicates as a the cuprous salts should be used as a powder or an aqueous dispersion and there is nothing to suggest that the salts or be used in the form of coating compositions for marine as discussed Examples of used in compositions are natural binders or synthetic polymers such as drying colophony and its polyvinyl and polyacrylic epoxy resins which may or may not be modified and as well as solvents such as for example or distillation of as methyl ethyl or l polymer such such as silicones or pigments and supplementary biocidal especially The amount of metal dithiocarbamate to be used depends on the viscosity and the amount of paint to be deposited on the substrates to be As a it can vary within wide limits as a general amounts which give a coating weight on a substrate of and 60 of cuprous of surface area of the are sufficient to achieve the desired molluscicidal and algicidal The invention is illustrated by the following Examples unless otherwise all the parts are parts by EXAMPLE 1 The following formulation was prepared by mixing in a ball mill Cuprous 35 parts Colophony glycerine ether Pentachlorodiphenyl 5 Xylene 30 This which contained of cuprous was applied to steel sheet previously coated with a conventional protective 2 to give a coating weight of 330 of paint per m of After test of 1 year carried out in the sea on the keel of a the protection obtained was e uivalent to that obtained with an paint of the same in which a coating weight of 380 of cuprous copper per 2 was applied in the form of cuprous EXAMPLE A paint of the following composition was Cuprous parts Red iron oxide 10 Polyvinyl chloride resin 8 Colophony glycerine ether 6 phthalate Methyl isobutyl ketone Toluene 31 The paint was applied to sheet metal in 3 successive layers so as to provide a total coating weight of per 35 cuprous The protection system proved in its to one consisting of 3 layers a cuprous copper coating weight of 300 of a paint of identical composition but based on cuprous oxide EXAMPLE 3 40 of cuprous of a paint of the following composition were applied to a timber raft immersed in the Cuprous 35 parts Colophony glycerine 30 Pentachlorodiphenyl Xylene 30 II After one it was found that the protection equivalent to that of a paint of the same composition but in which 300 of copper the form of cuprous per m 2 had been EXAMPLE An marine paint was made up from the following Ferrous and cuprous 40 parts Colophony glycerine ether 30 Hexachlorodiphenyl 5 Organic solvent 25 On applying of cuprous of this paint to a substrate exposed to the action of marine for one the protection obtained was equivalent to that obtained with the same paint except that cuprous oxide was used as the pigment at a coating weight of 300 of mixed dithiocarbamate was prepared in accordance with the Patent Application mentioned by reacting ferrous sulphate heptahydrate and cuprous chloride in a sodium chloride brine aqueous sodium at and After filtration and washing with a paste containing about solids was EXAMPLE A by replacing the ferrous and cuprous dithiocarbaaate of Example 4 by granules of a mixed of zinc and cadmium coated with cuprous by precipitation in situ had the same The granules prepared as Zinc chloride and cadmium chloride in water were reacted at about and pH with sodium in water After filtration and washing with the filter cake was suspended in a solution of cuprous chloride in brine sodium chloride perlitre of The mixture was with sodium dithiocarbamate in water at and pH After filtration and washing with a paste of the desired pigment was The dry powder had a colour similar to that of the insufficientOCRQuality

Claims (1)

1. m A method of aquatic parasites to habitat of the a which is cuprous or A according to Claim 1 wherein the in substantial of elkyldit or 3 hod according to 1 or 2 wherein an A method according any of the preceding cuprous or A method according to any of the preceding claims the cuprous employed in conjunction a nickel A iaethod according to om of tho preceding the cuprous ealt applied to to 1 aa described Alt ling compositions c a cuproue defined in Claisa t or at one conventionally in coating composition according to Claim 8 wherein and are A composition according to Claim 8 or 9 in the of a A composition according to Claim 10 which contains such an amount o the cuprous salt when the paint is applied to a a coating weight of 30 to 60 cuprous copper per square metre of substrate is A composition according to any one of Claims 8 to which contains at least one of a drying colophony o a derivative a polyvinyl or polyacrylic an epoxy an alky ill resin or a A composition according to any one of Claims 8 to 12 comprising also a cadmium or nickel alkyldithiocarbamate or A composition according to wherein granules of the cadmium or nickel alkyldithiocarbamate or are coated with the cuprous A composition according to Claim 8 as described in any one of the Attorney for Applicants 10 insufficientOCRQuality