Patent GB-778297-A (GB)
Title: A process for the manufacture of dispersions of powders
IPC: C09C3/08
Filed: 1953-12-07
Abstract: A powder is dispersed in a non-aqueous liquid, highly viscous or plastic medium by impregnating it with an electroneutral salt the anion and the cation of which each contain an organic residue containing at least 6 carbon atoms and the cation of which is derived from a cation-active onium compound, or with a substantially equimolecular mixture of an anion-active and a cation-active onium compound furnishing said residues, and dispersing the mixture in said medium.  Specified media are varnish and paint dispersion media (specifically linseed oil and ester gum/linseed oil media) and natural and artificial rubber, rubber regenerates or rubber substitutes.  The impregnation may be effected e.g. by stirring the powder into a solution or suspension of the salt or the components thereof in an aqueous or organic medium, separating the powder from the solution and then drying the powder; or by sprinkling or spraying a solution of the salt on to the dry pigment; or by grinding and crushing the salt and powder in an edge-runner or other specified types of mill. After impregnation the powder is worked into the medium, if desired at elevated temperature, (e.g. with normally solid materials) by known methods such as stirring or milling.  In specific examples, (1) zinc sulphide is dispersed in linseed oil by impregnating with the salt formed from octyl-pyridinium chloride and sodium octylsulphate to form a paint.  (2) Lead cyanamide is dispersed in an ester gum linseed oil varnish with the salt formed from equimolecular quantities of di-methyl-cyclo-hexyl-dodecylammonium chloride and octylbenzenesodium sulphate to form a paint.  (3) A finely divided silicic acid is dispersed in crepe rubber together with zinc oxide, sulphur and mercaptobenzthiazol-disulphide, the electroneutral salt impregnating the silica being formed from dimethyldodecylammonium chloride and sodium alkylsulphate.  The following powders are specifically mentioned as being dispersible by the agents of the present invention:-inorganic oxides, hdroxides and salts, such as are used in varnishes and paints as colour pigments or blending agents, e.g. ochre, red lead, iron oxide, titanium oxide, zinc sulphide, barium sulphate, calcium carbonate, metal powders such as metal bronze powders; fillers for rubber and rubber regenerates, such as soot, zinc oxide, finely divided silicic acid, silica gel, calcium silicate or aluminium silicate; powder bases such as talcum, rice flour, and starch and bleaching clays, pumice stone powder, kaolin, alumina, active carbon, cork powder and wood powder.  The electroneutral salts used are prepared from onium compounds e.g. ammonium, sulphonium and phosphonium compounds, possessing per molecule at least one organic residue having at least 6, preferably 6 to 20 carbon atoms, and possible also containing heteroatoms.  Specifically mentioned are trimethyl - octyl - ammonium - chloride, trimethyl - dodecylammonium chloride, trimethyl - octadecylammonium-methosulphate, dimethyl - dioctadecylammonium chloride, dimethyl - dodecyl - benzyl - ammonium chloride, dimethyl - cyclohexyl - alkyl - ammonium chlorides with alkyl residues having 10-22 carbon atoms or mixtures thereof, dodecylpyridinium chloride, and hexadecylpyridium bisulphate. The anion-active group may be supplied by compounds having at least one residue with at least six carbon atoms, and preferably at least one acid, salt-forming group which has been neutralized by inorganic or organic bases, specific compounds mentioned being, alkyl sulphates, alkyl sulphonates, alkylbenzene sulphonates, salts of dialkyl- or dialkylaryl - disulphon-imides N - acyl sulphonamides (see Specification 749,138 [Group IV(b)], fatty acid salts, and water soluble salts of the condensation products of higher molecular weight carboxylic acid halides or sulphonic acid halides with albuminous substances (the hydrocarbon residues of these anion active compounds can be interrupted by heteroatoms, such as oxygen, sulphur, or nitrogen or by heteroatom groups such as ester, carbonamide or sulphonamide groups, or can contain substituents such as hydroxyl, mercapto or amino groups); water-soluble salts of fatty acids, wax acids, naphthene acids, resin acids, octyloxyacetic acid, hexadecylmercaptoacetic acid, C - alkylcresoxyacetic acids; water-soluble salts of compounds containing inorganic acid groups, such as dodecyl-sulphuric acid ester, the sulphuric acid ester mixture of a fatty alcohol mixture obtained from coconut oil by catalytic reduction, oleylsulphuric acid ester, the sulphuric acid ester of ethyleneglycol-mono-octylether, the mono- or di-sulphuric acid ester of glycerine - monostearic acid ester, the phosphoric acid esters of decanediolmonoacetate, the o  - hexylthioether of octylthiosulphuric acid ester, N - butyl - N - dodecyl - sulphamic acid, the sulphuric acid ester of b  - hydroxy - g  - (sec. - octylcresoxy) propane, sec. - octylphenoxyethane - sulphuric acid ester, N - oleyl - N-methyl - aminoethane - b  - sulphonic acid, stearloxy - ethane - b  - sulphonic acid, the N - cetylsulphony - sulphanilic acid, the o  - cyclohexylether of decanesulphonic acid, sec. - octylphenyl - benzlether - 41 - sulphonic acid, alkylbenzenesulphonic acids with alkyl residues having approximately 6-18 carbon atoms, the mixture of isomeric 2 - isoalkyl - cresoxy - benzoic acid - 5 - sulphonic - acids with alkyl residues having 5-11 carbon atoms, 1 - sec. - octylphenoxybenzene - 2.5 - disulphonic acid, 1 - sec. - hexylphenoxy - 2 - (acetylamino) - benzene - 4 - sulphonic - acid, the sulphonation product of sec. - octyl - 1 - cresylbenzylether, and the sulphonation product of cresoxyacetic acid dodecylamide.  The electroneutral compounds may be prepared e.g. by precipitation from equimolecular mixtures of aqueous solutions of the two components.  Preferred proportions of the electroneutral salts are 0.05-10 per cent, preferably 0.2-5 per cent by weight.  Reference has been directed by the Comptroller to Specification 747,842.ALSO:A pulverulent filler is dispersed in natural rubber or rubber regenerates by impregnating it with an electroneutral salt the anion and the cation of which each contain an organic residue containing at least 6 carbon atoms and the cation of which is derived from a cation-active onium compound, or with a substantially equimolecular mixture of an anion-active and a cation-active onium compound furnishing said residues and dispersing the mixture in said medium. The impregnation may be effected e.g. by stirring the filler into a solution or suspension of the salt or its components in an aqueous or organic medium, separating the filler from the solution and then drying; or by sprinkling or spraying a solution of the salt onto the dry powder; or by grinding and crushing the salt and powder in an edge-runner or other mill.  After impregnation the powder is worked into the rubber &c., if desired at elevated temperature, by known methods such as milling.  Preferred proportions of the electroneutral salts are 0,05-10 per cent, preferably 0,2-5 per cent by weight.  In a specific example finely divided silicic acid is dispersed in cr<\>zepe rubber together with zinc oxide, sulphur and mercaptobenzthiazyl-disulphide, the electroneutral salt impregnating the silica being formed from dimethyldodecyl-ammonium chloride and sodium alkylsulphate.  The following fillers are specifically mentioned: soot, zinc oxide, finely divided silicic acid, silica gel, calcium silicate and aluminium silicate.  The electroneutral salts used are prepared from onium compounds e.g. ammonium, sulphonium and phosphonium compounds possessing per molecule at least one organic residue having at least 6, preferably 6 to 20 carbon atoms, and possibly also containing heteroatoms.  Specifically mentioned are trimethyl-octyl-ammonium-chloride, trimethyl-dodecylammonium chloride, trimethyl-octadecylammonium-methosulphate, dimethyl-dioctadecylammonium chloride, dimethyl-dodecylbenzyl-ammonium chloride, dimethyl-cyclohexyl-alkyl-ammonium chlorides with alkyl residues having 10-22 carbon atoms or mixtures thereof, dodecylpyridinium chloride, and hexadecylpyridinium bisulphate.  The anion-active group may be supplied by compounds having at least one lipophilic residue with at least six carbon atoms, and preferably at least one acid, salt-forming group which has been neutralised by inorganic or organic bases, specific compounds mentioned being, alkyl sulphates, alkyl sulphonates, alkylbenzene sulphonates, salts of dialkyl- or dialkylaryl-disulphon-imides or N-aryl sulphonamides (see Specification 749,138 [Group IV(b)], fatty acid salts, and water soluble salts of the condensation products of higher molecular weight carboxylic acid halides or sulphonic acid halides with albuminous substances (the hydrocarbon residues of these anion active compounds can be interrupted by heteroatoms such as oxygen, sulphur, or nitrogen or by heteroatom groups such p  as ester, carbonamide or sulphonamide groups, or can contain substituents such as hydroxyl, mercapto or amino groups); water-soluble salts of fatty acids, wax acids, naphthene acids, resin acids, octyloxyacetic acid, hexadecylmercaptoacetic acid, C-alkylcresoxyacetic acids; water-soluble salts of compounds containing inorganic acid groups, such as dodecyl-sulphuric acid ester, the sulphuric acid ester mixture of a fatty alcohol mixture obtained from cocoanut oil by catalytic reduction, oleylsulphuric acid ester, the sulphuric acid ester of ethyleneglycolmonooctylether, the mono-or di-sulphuric acid ester of glycerine-monostearic acid ester, the phosphoric acid ester of decanediolmonoacetate, the o -hexylthioether of octylthiosulphuric acid ester, N-butyl-N-dodecyl-sulphamic acid, the sulphuric acid ester of b -hydroxy-a -(sec.-octylcresoxy) propane, secl-octylphenoxyethane-sulphuric acid ester, N - oleyl - N - methyl - aminoethane - b  - sulpho