CA1087959A - Aqueous multiphase dispersions and preparations thereof - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method of producing dispersion in an aqueous medium of aqueous globules larger than the colloidal dimension and resistant to shear without subdividing, the phases being insoluble or immiscible in one another through interaction of the colloidal ionic reactants of opposite charge, preferably macromolecular polyelectrolytes, present in different phases.
Optionally the globules may be separated from the medium and dried as discrete particles. When the aqueous globules differ in colour the compositions are useful in producing multicolour coatings, ceramic glazes and fibrous webs. Thus the dispersions may be applied to a surface to impart either a first decorative appearance, in which the globules appear in uniform spaced relationship with each other, relatively independently of method of application, the medium being clear or translucent, or a second decorative appearance, which varies according to the method of application, when the medium also is coloured, and different in colour from the globules, such that when applied by brush or roller a streaked or mottled appearance results.

Description

1015795~
~1 -D 0~ TH~ I~VE~TION
~he invention relate~ to aqueou~ di~persions : of aqueouS globules, useful for ex~mple to produce textured or multicoloured coati~s, ceramic glazes and fibrous webs, or on removal of the aqueous dispersion medium, to produce dry granules or particles.
RIOR ART
' Di~persions of aqueous globules made by incorporating hydrophilic colloid in a fir~t aqueous - 10 phase, which interacts with insolubilizing agent for said colloid contained in a second aqueous phase, are disclosed in United States Patentæ No~. 5,458,328, 3,725,089 and 3,852,076. In such prior art the reac-tions responsible for insolubilization have been . .
15 exclusively or predominantly non-colloidal or non-ionic or both.
Non-colloidal reactions are those in which at least one reactant is non-colloidal~ for example the reaction between guar gum or locust bean gum and a non-20 colloidal salt such as water-soluble borate~ .
Non-ionic reactions are those in which at least one of the reactants is non-ionic, for example the reaction between ionic oolloidal cla~ and hydroxy-ethyl cellulose, or in which the reactive groups o~
. 25 both re~ctants bear the same kind of charge.
- In ionic reactions as discussed herein both reactants are ionic and opposite in charg2, for example reactions between cationic and anionic colloids.
Membranes or ma~rices formed by no~-ionic 30 reactions are dependent on relatively weak intermole-~ cular forces and ~ail to provide globules which can withstand high shear forces as in brushing and high pressure spraying without breaking, while at the same time having relatively fluid or pliable character-35 istics~

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Insolubilization by means of non-colloidal reactions, such as between a salt and an organic colloid, generally leads to poorly hydrated flocculates rather than flowable globules. In the few cases where hydrous gels are formed there is a tendency ~or the reaction to propagate through the interior of the insolubilized globules, and degree of gelation is difficult to con-trol.
Several prior art kinds of coating disper-sions ha~e been found acceptable for spray application, but deficient when applied by brush orroller, due to - one or more of the following reasons (a) inadequate resistance of globules to breakdown or shear, (b) hard, gelatinou~ or brittle globules which give low surface drag and tendency to skid on smooth surfaces or (c) in-adequate separation of globules, such as often results from interchan~e between dispersed and continuous phases, which aggravates skidding tendencies.
lt is an object o~ the present invention to ` 20 overcome such limiations by utilizing a new and distinct concept.
~HE I~VEN~I0~
_ ~ he present invention uses water-soluble or colloidally dispersible reactants which are both colloidal and ionic to produce dispersions of globule~
of a first aqueous phase in a second aqueous phase, the two phases being rendered mutually insoluble through reaction between an anionic colloidal reactant in one phase with a cationic colloidal reactant in the other phase. ~he phase relationship of the dispersions may be either cation~in-anion or anion-in-cation. At least the dispersed phase contains a reactant which is an aqueous macromolecular polyelectrolyte as hereinafter defined.
~ 35 It is an object of the invention to produce ;``
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~LO~ 59 aqueous dispersions of improved s~ability and globule strengt~.
It is another object o~ the invention to produce dispersions comprising a wider variety of film-formers than those of the prior art.
It is another object of the invention to produce dispers~ons useful as multicoloured- or textured coating compositions suitable for application by brush or roller, as well as by spray.
It is another object of the inYention to produce dispersion coatings whi:ch have improved drying rate and i~proved water-xesis-tance.
It is another o~ject of the in~enti.on to produce dispersions useful ~.n producing multicolour ceramic glazes.
It is another object of the inYention to provide dispersions wh~ch are useful in producing multicoloured webs from fibrous materials such as cellulose, asbestos or synthetic polymer ~ibres. , It is another o~ject of the invention to provide dispersions containing aqueous globules which can be readily separated from sai:d dispersi.ons and converted by drying into granular or particulate products.
~ ccording to thR present invention, there is provided a di~sper5ion ~ globule5 of a ~ir~t aqueous phase in a continuous second aqueous ph.ase, ch.aracterize.d in that the ~lobules o~ th.e first a~ueous phase are of suf~icient size as to be visible to the n~ked eye and contain a macxomolecular col-loidal polyeIectrol~te that may be ei:ther cationic or anionic, the` second aqueous ph.ase containing an ioni.c colloid that is . , -~ : :

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opposite in charge to that of the colloidal polyelectrolyke in the first phase, the first phase being insolubilised by interaction between said ionic colloid and said colloidal poly-electrolyte into the said globules which may be subjected to substantial shear stress ~ithout subdividing.
In another aspect, the inventi.on provides a method of preparing the dispersion which method comprises:
a) providing a first aqueous material containing a macromolecular colloidal polyelectrolyte th.at may be either i: lQ cationic or anionic, b~ intermixing said first aqueous material with a second aqueous material wh.i.ch contains an ionic colloid that is of opposite charge to the colloidal polyelectrolyte in the first a~ueous phase, and c~ subjecting the mixture to shear to subdivide said first a~ueous m~terial into a plurality of globules.
In a further aspect, there is provided an article carrying a coating formed by applying a film of a dispersion of globules of a first aqueous phase in a continuous second aqueous phase and dr~i.ng or curing the film.
THE PREFERRED EM ODIM~NT
It .~s generally agreed that most natural and synthetic pol~mexs are molecular or macromolecular colloids in which the colloidal particles are su~stantially single large molecules, bein~ di5ti.nguished thereby from miceIlar colloids, such as soaps o~ synthetic detergents, in wh~ch the parti.cles contain an ag~xe~ation`of smalle~ molecules.

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~)8'7S~S~3 In a pre~exred embodiment o~ the inventi.on the ionic colloid reactants in both ph.ases are macromolecular, soluble or collo.~dally di.spersible in water, : .--.-. .

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colloidal polyelectrolytes which contain many ionic groups per molecule.
~O~-PO~YM~RIC R~CTAN~lS
~uitable ionic colloidal reactants which are not polymeric comprise, for example, colloidal clays such as hectorite or saponite, which are anionic, or colloidally dispersed alumina, which is cationic.
The preferred colloidal clays are those known as montmorillonites, montmorillonoids or~smectites, these minerals being characterised by a tendency to swell by absorbing water between adaacent crystal layers i ~nd to split into charged fragments capable of ~orming colloidal sols, typical examples being montmorillonite, be-idellite, saponite, stevensite, nontronite and hactorite. Syrthetic clays have been found parti-cularly advantageous, for example ~aponite from Laporte Industries, Macaloid, a refined natural hectorite from ~ Industries~ Baroid Division and Veegum, a refined natural saponite from R~T~ Vanderbilt Co~ Incorporated.
Colloidal silica is a useful ionic reactant of the non-polymeric t~pe.
Aqueous emulsions of ionic organic polymers which are not molecularly dispersible in water, for ; 25 example Rhoplex PR-26, a cationic acrylic polymer emulsion from Rohm & Haas, may also be considered a~
suitable reactants in the present context, as they generally comprise particles near the borderline of the colloidal range, which have a large surface area for potential reactivity.
Suoh reactants not polymeric in the present context are preferably used in conjunc-tion with water-' soluble or colloidally disper~ible macromolecular ~, polyelectrolytes of the same ionic type.
The ionic colloid in each phase should be . .

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~08795''3 predominantly either anionic or cationic, rather than `evenly-divided amphoteric. As explained hereinafter, however, it is o~ten useful to employ in a single phase major and minor portions o~ ionic colloids of opposite charge~
MACROMOLECULAR_IO~IC RLACTANTS
The suitable macromolecular ionic colloids or macromolecular polyelectrolyte~ are soluble or colloid-ally dispersible i~ water and are preferably of very high molecular weight, such as to produce viscous solutions or dispersions in water at concentrations of less than 10 percent by wei~ht, often at 1-2 percent by weight, and are well-known in paint technology and other fields, for example as thickeners ~or aqueous composi-tions. Granular water-insoluble macromolecular poly-electrolytes used, ~or example, for ion-exchange processes are not suitable.
Other useful macromolecular polyelectrolytes are those which provide solutions of moderate viscosity at concentrations of about 10~60 percent by weight, for example water-thi~nable oil-modified polyesters and polymeric surfactants such as naphthalene sulphonic acid condensates. Such polyelectrolytes are often strongly reactive. Generally however it is preferable to use them in conjunction with hi~h viscosity macro-molecular polyelectrolytes, preferably with those which promote good hydration of the reaction product, as discussed hereinafter.
~ Anionic macromolecular polyelectrolytes ;- 30 include, without limitation thereto, sulphonated, sulphated or carboxylated polymer~ or condensates such as ~rom sulphonated polystyrene, sulphonated polyvinyl ~ toluene, sulphonated benzene or naphthalene formalde-;~ hyde condensates, sulphated cellulose, carboxylated ;" ~5 cellulose, carboxylated vinyl polymers, carboxylated `;``
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io8l7g59 acrylic polymers~ water-soluble polyesters~ maleinized oils and maleiniæed esters of ~tyrene-allyl alcohol copolymers. ~arboxylated cellulosics which may be used include carboxy~lkyl-cellulosics such as carboxy methyl cellulose and carboxy-alkyl hydroxyalkyl cellu-losics such as carboxy methyl hydroxy propyl cellu-lose. Either linear or cross-linked polymers may be used. Superior results may be obtained by using anionic reactants of more than one type, such as a combination of sulphonated and carboxylated polymers, of high and low viscosity polymers or of linear and cross-linked polymer~ Anionic colloids co~taining sulphonic or sulphate groups are typically more reacti~e than those containing carbGxyl groups, ~nd preferably should be included when maximum globule strength is required.
Sulphonated polystyrene, for example the Versalt polymers from ~ational Starch, are suitable. The preferred carboxylated polymers are carboxy methyl cellulose and carboxylated acrylic polymers such as Acrysol polymers from Rohm & Haas.
Suitable cationic macromolecular poly-~ electrolytes comprise - onium compoundsg defined in ; Hackh's Chemical Dictionary (4th Edition) as being o~
the type RXHy, an organic isolog of ammonium contain-ing the element ~ in its highest positive valency7 and including ~or example quaternary ammonium, phos-phonium, arsonium and stibonium compounds where X is pentavalent; ternary sulphonium, oxonium and stannon-ium compounds where ~ is tetravalent and iononium compounds, where ~ is tri~alent. Stron~ly basic poly-; mers, such as quaternary ammonium compounds are preferred, rather than weakly basic pol~mers such as those comprising primary, secondary or tertiary amine ~roups. Besides aliphatic types quaternary bases derived from heterocyclic bases such as pyridinium, , . :
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quinolinium, piperidinium and morpholinium compound~
may be used. ~`he most preferred cationic reactants are quaternary derivatives from macromolecular colloid~
including derivatives of poly-saccharides such as cellulose, for example Polymer 3R resins from Union Carbide Corporation9 starch, carrageenan, agar and natural gums, also derivatives of synthetic polymers such as polyvinyl pyrolidone, polyvinyl alcohol, epoxy and acrylic polymers. Insolubilization of ionic colloidal reactants may be promoted by the use of suitabl~ selected non-colloidal chelating agents, for example boraxO
PAYLOADS
In the majority of instances the present aqueous dispersions will contain a water-thinnable component, for example a polymer latex, in addition to the colloidal ionic reactants necessary to produce the required phase separation, characterizable as "payload", which is related to the use of the composition.
Preferred latexes are those stabilised with surfactants which are at least partially non-ionic.
In multicoloured or textured coatings, the payload may be a water-thinnable film-forming cempo~i-tion, contained in globules which may be coloured differently from others, to form a pointillistic design ; when applied to a sur~ace. ~he continuous dispersing medium may also contain a water-thinnable film-forming composition, which may be substantially transparent, capable of depositing a glossy or semi-glossy film which can partially or completely overlay a substantially opaque film which is simultaneously deposited by the ~lobules. ~1he continuous medium may be coloured differentl~ ~rom the globules, u~ique colour effects being obtainable if containing a tranqparent colourant.
Mottled or striped appear~nces may be obtained, .
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: 1()879S9 depending on the method of application, such as by brush, roller or other type of tool. When vari-coloured coatin~s are not desired unique one-coat textured coatings of a single colour are possible, such as would normally require several coating operations. In a special variation light-reflective elements such as glass beads or irregularly shaped particles are incorporated in the continuous phase, bound by clear film-forming material to provide reflective paints of high visibility.
hxceptionally pleasing colour effects can be obtained by the use of tinted pigment pastes.
Suitable pigment pastes are those in which the pig~ent i~ ground into a water-miscible liquid carrier which is also compatible with the other components of the ; multicolour paint, for example a low molecular weight ~lycol. The pigment added in this way, to the dispersed multicolour paint, of course goes into the continuous phase.
Either or both phases may contain particles such as metallic powders, flakes or fibres, or of non-metallic materials such as cellulose or asbestos fibres; also various filler or extender components, pigments, defoamers, coalescing agents and the like, as commonly used in coating compositions.
Suitable water-thinnable film-forminæ
polymers include polymer latexes, aqueous solution coatings and waterborne emulsions o~ water-miscible polymers, optionally dissolved in water-miscible ~olvents, and include for example latexes based on polyacrylic, polyvinyl acetate, polyvinyl chloride, polystyrene, natural and synthetic rubber, copolymers such as vinyl acetate-acrylic, emulsified oils, alkyds, ` epoxy resins, polyurethane~ ~nd asphalt; also emulsions of solvent solutions of, for example, alkyds, .

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, g ~ nitrocellulose and styrene-butadiene. Odours and fire -- hazards associated with the use of volatile organic solvents are substantially eliminated.
; The resulting coating films may be air-drying7 thermosetting, or formed by heating fusible ; polymers such as polytetrafluorethylene or vinyl dispersion resins. By use with a suitably emulsified plasticiser quch dispersion resins may be dispersed in water and aggregated into visually distinguishable globule~ without the need for volatile organic solvents.
Another suitable type o~ payload comprises ceramic minerals~ as frit, or non-fritted, capable of fusing at elevated temperature for the production o~
decorative ceramic glazes of great variety. ~he minerals may be in the globules, or in both globules and medium.
A further suitable payload is paper pulp, which likewise may be incorporated also in the medium.
Unique decorative effects for paper products such as `; 20 sheets, cartons and the like are obtainable when pulp-containing globules are coloured differently ~rom each ; other, or from the aqueous pulp-containing medium surrou~ding them. Such procedures may be adapted to the production of many kinds of self-supporting webs or matrices from fibres or granules such as from cellu-lose, asbestos, glass, synthetic polymer or sawdust.
Globules containing such materials may be used with or without polymeric binders to form sheets or boards, ;; imitation cork or various kinds of non-woven ~abrics.
; 30 Globules formed from any desired waterborne mat~rials may be after-treated to remove the continuous aqueous medium, the globules thereafter being converted to dry granules, or particles~ which may be adapted to i have some desired property not present in the starting material such as changed consistency, re~uced toxicity ;

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79Sgl and the like, or which may be used as a powder coat-ing, or a moulding composition, or as colour concen-trates for dispersion in other coating or moulding compositions. More specifically such granules may contain waterborne insecticide, for reduced toxicity during handling; fertiliæer, for delayed solubility characteristics, powders such as diatomaceous earth or asbestos, for reduced dusting properties or water-borne odorants or flavorants, which may also be in the form of aqueous globules.
HYDRA~ION AND D~NDRA~ION
Strongly reactive ionic colloids can be sufficiently active to induce dehydration of the insolubilized globules, evidenced by shriveling ~r flow of liquid Irom globules to continuous medium; complete collapse of the globules into irregular shreds result-in8 in severe cases.
Deh~dration may be countered by use of a proportion of polymeric colloid ¢ontaining nonionic as well as ionic h~drophilic solubilizing groups, for example carboxymethylhydroxypropyl cellulose. Alter-natively simple mixtures of non-ionic and ionic colloids may be used, especially in the dispersed globules, in ratios of 10-15:90-85 f~r maximum particle size, or 50-75:50-25 when smaller particles are satisfactory.
Examples of suitable non-ionic colloids are alkyl- and hydroxyalk~l ethers of polysaccharides such as methyl cellulose, methyl hydroxy propyl cellulose, hydroxy ethyl cellulose and hydroxyethyl guar. Hydroxy ethyl derivatives of polysaccharides are often preferred.
Such non-ionic colloids are added more oautiously to the continuous medium to avoid reducing globule strength. In some instances however (see ~ Example VII hereinafter) small proportions of anionic-`I 35 nonionic colloid improve particle strength.

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1(~879S9 PRE--REAC~ION O:l? DI~;PERSION X~L~SE
For maximum ~lobule size or strength it is often advantageous to increase the viscosity of the phase to be dispersed before dispersion by adding a minor proportion of a reactive ionic colloid opposite in charge to that of the macromolecular polyelectro-lyte contained in the said phase~ ~or example, an anionic reactant, preferably an anionic polyelectro-lyte which could be a surfactant or high viscosity macromolecular colloid, would ba an appropriate ~ thickening agent-for a disperse phase containing a ; cationic macromolecular colloid. A blend of different anionic reactants may be advantageous; for example one may contain sulphonic groups, the other less re-active anionic groups.
When such systems are the basis of pigmented paints the anionic pol~rmeric surfactants also facilitate ; pigment dispersion and stabilisation. Preferably they : are added during initial pigment dispersion, before the . 20 addition of the cationic colloid. ~he amount of '.i reactant added to a phase in this manner should be such - as to react with a part only of the macromolecular polyelectrolyte of opposite charge present, but at the same time sufficient to thicken the said phase, and is easily determined by experiment; too much of such a reactant may produce a lower rather than a higher iscosity.
DISP~RSION C~L~RAC~`~RISTICS
~he strength and consistency of the globules is largely determined by the type of polyelectrolytes t" used as reactants, their molecular weight, concen-tration, type of ionic groups, ratio of non-ionic to ionic hydrophilic groups and other characteristics, globule strength being enhanced by use of reactants of - 35 higher colecular weight, more reactive and fewer non-.~ .

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~'7 reactive ~roups, but only insofar a~ can be done with-out excessive loss of hydration.
The production of textured effects requires lar~er and harder globules than those required ~or smooth coating films.
By means of the present invention globules having good æhear resistance, a variety of dif~erent globule consistencies and various viscosities for the continuous phases, are attainable, making possible brush- and roller applied patterns which were not previously attainableO
When colloidal clay is to be used its dis-persion is aided by an admixture of water-soluble inorganic phosphate, preferably tetra-sodium pyrophos-phate which often permits the formation of very fluidand sometimes nearly clear dispersions containing up to 1 5-10 percent by weight of colloidal clay, thereby facilitatin~ high concentrations of clay if desired, also easy admixture with macromolecular colloids when deæired. Thus ~aponite 5 is marketed as a powder believed to contain about 5 percent by weight of tetra-sodium pyrophosphate.
Colloidal clay is preferably used in minor amount in conjunction with anionic macromolecular polyelectrolyte, of which it enhances the reactivity.
It is well-known that swelling clays of the smectite type tend to increase the viscosity of certain anionic ` colloids such as catboxy methyl cellulose and, as used ~; in the present compositions, the complex formed between such materials is believed to react more effectively towards a cationic macromolecular colloid than either ~` material alone. As little as 0.25 percent of a completely synthetic clay such as ~aponite 5 may be effective and correspondingly 0.5-1.0 percent of less reactive types such as natural or refined natural -.-. - . ... .. - . . . . : , , , - . , , ~ -: . . . : ..

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clays, such amounts being by weight per 100 parts o~
the phase concerned.
Colloidal clay is often a useful adjunct for its other characteristics, ~or example as an effective thickener at relatively l~w concentrations; also in helping to maintain satisfactory hydration of dispersed globules. ~he disadvanta~es of using clay as anionic reactant include water-sensi~ivity, a tendency ~o promote slow-drying, relatively large amounts such as

2-10 percent by weight of the phase concerned, and tendency towards uncontrollability when used alone, even i~ used in both phases. It is an advantage o~
the present invention that reduced amounts o~ colloidal clay may be used.
~he payload, for example a polymer latex~
should be compatible with the colloid used in its respective phase. In the compositions of the present invention, unlike in the prior art, this condition is often attainable with a single latex compatible with both phases.
PREPARATION 0~ DISPERSIO~S
; ~he dispersions are prepared by mixing the desired proportions o~ each phase and stirrin~ with moderate agitation to produce the desired globule size.
Ordinary paddle-type agitators are satisfactor~, using stirring rates of about one hundred to several hundred revolutions per minute, dependin~ on the desired globule size, faster rates reducing average size. ~he phase which forms the globules may be added in one or in several ; 30 additions.
In preparing multicolour coatings or glazes it is generally convenient to prepare dispersion phases ` of each colour separately, afterwards mixing them in ths desir~d proportions. Multicolour dispersions may also be made directly by adding dispersion phases of ~ .

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il'795i~3 dif~erent colour successively to the dispersing medium, stirring after each addition to produce the desired globules. When a viscous continuous medium is required the amount of stirring may be minimised by forming an initial dispersion in a medium of relatively low viscosity, containing a relatively high proportion of reactive ionic colloid, a second more viscous medium which may contain a lower proportion of or no reactive colloid being then added, preferably containing any coloured or extender pigment to be used in the continu-ous medium, minimising possible absorption of pigment by the globules.
Cation-in-anion dispersions have the current advantages of greater availability of anionic polymers suitable for use in the continuous medium and of permitting more effective variation of the size and consistency of the dispersed globules, and of higher ratios of globules to dispersing medium, which may be as high as 4:1 by suitable choice of reactants. When ratios of 1:1 or less are acceptable, or when parti-; cularly fluid dispersed globules are desired, anion-in-cation dispersions are the more suitable.
EXAMPLE I
Red-yellow coating composition containing ionic film 25 formers: ~o 'payload' Composition A ~ Red dispersion Part by Cationic starch derivative, 5% solution in water (C~0 starch, National Starch & Chemical Corp.) 30 Cationic cellulose ether, ~/o solution in water (UC0~ ~uatricel CCE-2~I, Union Carbide Corp.) ~Red iron oxide pigment 4.S
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108'7~59 -'15-~'he pigment was dispersed in the cationic ~tarch solution, then blended with the cationic cellulose solution. ~he resulting red coating compo~ition was dispersed a~ discrete globules in an equal weight of an aqueous anionic dispersing medium containin~ water and 0.5% sodium carboxymethyl cellulose (C~C 7H3~F, Hercules Inc.) 0.125% sodium condensed naphthalene sulfonate (Lomar D, ~opco Chemical Division Diamond Shamrock Chemical Co.) Composition B - Yellow di~persion ~s Composition A above, except that yellow iron oxide pigment was substituted for red iron oxide pigment.
Composition C - Red-~ellow coatin~ com~osition Equal parts of Compositions A and B were mixed to produce a red-yellow coating composition. ~his was applied to a substrate with a standard spray gun, to give a red-yellow multicolour coating. ~ither small or large colour patterns up to 1/4 inch in siz~ could be obtained by variation in spraying pressures In this example the cationic and anionic re-actants are the only film forming materials.
~XAMPIE II
.~, Blue-White coating composition; Payload - acrylic co-i polymer emulsionO
Composition A - White dispersion. Parts bY
Acrylic copolymer emulsion, 46% solids (Polyco 2719, ~orden Chemical Division, Borden Inc.) 35.7

3 ~itanium dioxide - 10.7 ~ ~onyl phenyl polyethylene glycol ether ; (~er~itol ~PX~ Union Carbide Corp.)0.2 Cross-linked sulfonated polystyrene, 3% solution in water (2166-869 National Starch & Chemical Corp.) 26.8 35 Water 26.6 100.00 '' ~9~
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~ :~08'7~59 Composition A was prepared in the usual manner, then dispersed a~ globules by stirring in an equal weight of a cationic dispersing medium containing water and 0.5% cationic cellulose ether (Ucon Quatricel CC~-25M, Union Carbide Corp ) 1% cationic acrylic polymer emulsion solids (Rhoplex PR-26, Rohm & Haas Co.) Composition B - Blue dis~rsion This was as composition A, except that the white dis-persion phase wa~ tinted before dispersion with 1% by weight of a phthalo-blue pigment dispersion.
Composition C - Blue-white coatin~ comPOSition ~qual parts of Compositions A and B were mixed and applied with standard spray gun to give a blue-white multicolour coating ~ilm, characterized when dry by relatively large pattern and low texture, with colour specks up to 1/4 inch in size.
This example represents dispersion containing anionic reactant in the di~persed phase and catio~ic reactant in the continuous phase.
E~AMPI~ III
Red-blue coating composition; Payload - vinyl acetate copolymer emulsion.
Composition ~ - Red cationic dispersion Phase.
Vinyl acetate copol~mer emulsion, 55% solids el~ht (Polyco 804, Borden Chemical Division, Borden Inc.) 23.6 Calcium carbonate 8.0 Red iron oxide 4.0 ~onyl phenyl polyethylene glycol ethex (~ergitol NP~, Union Carbide Corp.) 0.2 Ammonium hydroxide (28% NE3) 0.8 Cationic cellulose ether, 2/o solution in water 47.4 (UCO~ Quatric~l CCE-25M) Water 16.0 100.00 ,~ .
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Com~osition B - Blue cationlc disPersion phase As Composition A except that red iron oxide was substi-tuted by 4 additional parts of calcium carbonate and 0.5 part of phthalo-blue pigment dispersion.
Composition C Anionic dispersin~ medium Part b~
Sodium carboxymethyl cellulose, ~/o solution in water (CMC 7H3S~, ~ercules Inc.) 30.
Sodium condensed naphthalene sulfonate, ~5%
solution in water (~omar D, ~opco Chemical 10 Division, Diamond Shamrock Chemical Co.) 0.5 Vinyl acetate copolymer emulsion, 5% solids (Polyco 804, ~orden Chemical Division, Borden Inc.) 22.5 Ammonium hydroxide (2~/o ~H3) 0.9 Water 46.1 100.00 I Composition D - Red disPersion i Composition A was dispersed by stirring in an equal weight of Composition C.
20 Composition E - ~lue d~s~ersion Composition B was dispersed by stirring in an equal weight of Composition C.
Composition F - Red-blue coatin~ comPo _tion ual parts of Compositions D and E were mixed and applied with standard spray gun, giving a semi-glossy red-blue multicolour coating, with colour specks up to inch in size.
In this example both phases contain a film forming latex in addition to the polymeric ionic re-actants.
EXAMPLE IVWhite-black coating composition: Payload - vinyl acetate-acrylic copolymer emulsion.
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1~8~795~3 Composition A ~ Anionic disPersing medlum Parts b~
Sodium carboxymeth~Jl cellulose, ~/o solution 5 in water (CMC 7H, Hercules Inc.) 13.0 ~odium pol~styrene sulfonate, 2/o ~olution in water (VERSA-~ 700, National Starch &
. Chemical Corp.) 9-Sodium condensed naphthalene sulfonate, 10 25% solution in water (~omar D, Nopco Chemical Division, Diamond ~hamrock Chemical Co.) 0.2 Synthetic hectorite clay~ 8% colloidal dispersion in water (Laponite S, ~aporte Industries Ltd.) 8.0 Water 6~.8 100.00 Compositions B~ C - Single colour dispersions of disPerse phases in anionic dispersin~ medium.
~C ~:
Whibe Black Vinyl acetate-acrylic copolymer emulsion, 55% solids (Amsco Res~ ~011, American Mineral Spirits Co. Division, Union Oil Co. of California) 39.339.3 ~itanium dioxide 11.8 Black iron oxide _ 11.8 Aqueous solution of mixed chelating agents 26% active ingredient ~Chelon 62, Cowles Chemical Co.) 0.040.04 Sodium condensed naphthalene sulfonate, 25% solution in water (~omar D, ~opco Chemical Division, Diamond Shamrock Chemical Co.) 0.24 0.40 . 35 Ammonium hydroxide ~28% NH3) 0.35 0.35 Water 10.77 10.61 ` Cationic cellulosic derivative, 2~/o solu-tion in water ~Polymer ~R-30M, Union Carbide Corp.) ~ 37~5 Total cationic disper~ion phase 100.00 100.00 - - . . . .
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B C
White Black Composition A 50 50 ~he cationic dispersion phase~ were prepared by making latex paints of each colour in the usual manner, then adding the cationic cellulosic polymer. Dispersions of each colour were then prepared by dispersing the cationic phase in the anionic dispersing medium and stirring to produce the desired particle sizeO
Composition D - White-black coatin~ composition Equal parts of Compositions C and D were mixed and applied by spray to ~ive a sharply contrasting multi-colour coating. ~he pattern size varied with the size of the spray orifice, but many colour flecks as large as 1/2 inch were obtained using an orifice of 0~070".
; In this example globule strength was enhanced by use of the high molecular weight condensed naph-thalene sulfonate as anionic polyelectrolyte in the dispersed globules, to react with a portion o~ the cationic polyelectrolyte. It also serves as a pigment dispersant.
~ AMP~; V
Yellow-brown coatin~ composition for striped effects;
Payload - acrylic emulsion.
Compositian A - Anionic dispersin~ medium Yarts b~
-W-eight Sodium carboxymethyl cellulose, ~/o solution in water (CMC~7~3S~g ~Iercules Inc.) 13.1 Sodium poly~tyrene sulfonate, Z% solution in water ~VERSA-~L 700, ~ational Starch &
Chemical Corp.) 8~8 Synthetic hectorite clay, 8% colloidal `~ di~persion in water (~aponite S9 ~aporte Industries Ltd.) 8.1 Water 7-100.00 B~ , .
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8~7959 Composition B - Anionic Brown latex additive to dispersin~ medium Pl~rtshbt2 Acrylic polymer emulsion~ 50% solids ~elF:
(Rhoplex AC-388, Rohm & ~aas Co.) 57.5 Maleic adducted linoleic ester of styrene-allyl alochol copolymer, 63.5% solution in water/diethylene glycol monobutyl ether (RF-9069, ~lonsanto Co.) 1.4 Ammonlum hydroxide (28% NH3) 0~05 10 Calcium carbonate 13.9 ~alc 9-9 Brown iron oxide 4.0 Lampblack 0.4 Anionic polymeric dispersing agent, 25% solids (Tamol 731, Rohm & ~aas Co.) 1.0 Propylene glycol 1.9 2~2~4-trimethy1-1~3-pentanediol monoisobutyrate 1.9 Water 8.05 100.00 Composition C - Yellow-brown disPersion ~hase AcryIic polymer emulsion, 50% solids (Rhoplex AC 388, Rohm & Eaas Co.) 57 7 7 ~itanium dioxide 11.5 : Yellow iron oxide 11.5 Sodium tripolyphosphate, 1~/o solution in water 0.1 Aqueous solution o~ mixed chelating agents, 26% active ingredient (Chelon 62, Cowles Chemical Co.) 0.1 : Propylene glycol 0.6 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate 0.6 ~ Water 11~5 :~ Cationic guar gum, 2/o solution in water (Gendriv 162~ General ~lills Chemical, Inc.) 2.9 ~uaternized vinylpyrrolidone copolymer, 15%
; 35 ~olution in water (Gafquat 755, GAF Corp ) 3.~_ ~'otal cationic dispersion phase 100.00 .~

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.. -21 -We~ght Composition A 67 Composition B 133 The yellow latex pigment dispersion wa~ prepared in the usual manner, after which the cationic reactant~ were added. Yellow globules were formed by dispersing the resultin~ cationic disper~ion phase in Compositio~ A.
~he anio~ic brown Composition B was then added to form a dispersion of yellow globules in a brown continuous medium.
Gompo~ition C was applied by brush to porous or non-porous surfaces to yield a visibly multicoloured one-coat striated finish and by roller for a mottled 15 two-colour effect.
' EXAMPIE VI
White-brown coating composition for striped effects;
Payload - vinyl acetate-acrylic copolymer emulsion.
White latex dispersion pha~e Parts b~
20 Vinyl acetate-acrylic copolymer emulsion, Wei~ht 55% solids (~msco Res. 3011, American Mineral Spirits Co. Division, Union Oil Co~ of ~alifornia) 43.7 ~itanium dioxide 21.9 `25 Cationic ~orn starch derivative, 3% solution in water (CA~O 8, National Starch and Chemical Corp.) 3-5 Ammonium hydroxide (28% N~I3) 0,4 Aqueous solution of mixed chelating agents, 30 26% active ingredient (Chelon 62, Cowles Chemical Co.) 0.1 Water 4.2 Cationic cellulosic derivative, 2~/o solution " in water (Polymer 3R-30M, Union Carbide Corp.) 2~ .0 .
'' "' , , ' ~- ~.Q~3~79S9 Parts b~
Wei~ht Hydroxyethyl cellulose, ~/o solution in water (Cellosize QP-100M, Union Carbid~ CorpO) 5.2 Total cationic dispersion phase 100.00 Composition A of ~xample V (anionic dispersing medium) 80 Composition B of ~xample V (anionlc brown additive) 80 The mixture was prepared as in Example V. The ~verage globule size was larger than in the ~ormer example, many being 600-800 microns, and on application b~ brush the present composition produced a more pronounced striping ef~ect.
~he latex used in this example is more compatible with cationic polymers than Rhoplex AC-388~
~he cationic cellulosic polymer used here is also more reactive than cationic guar gum or vinylpyrrolidone copolymer. Cationic starch serves primarily as a pigment dispersant, added to the initial latex pigment preparatio~ before adding the other cationic polymer.
E$AMPIE VII
i White-red coating composition for pointillistic effects;
Payload - vin~l acetate-acrylic copolymer emulsion.
Composition A - Anionic disPersin~ medium. Parts by ~odium carbox~methyl cellulose, ~/0 solution Welght in water (~MC 7H, Hercules Inc.) 25.0 Sodium polystyrene sulfonate, 2% solution in water (VERSA-~ 700, ~ational Starch and Chemical Corp.) 12.5 " Sodium carboxymethyl hydroxy propyl cellulose, ; 3% solutio~ in water (~lucel 4G, Hercules Inc.) 5~0 Water 100.00 ,i,`i . ,~
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Parts b~
Composition B _ Anionic dispersin~ medium Composition A 83.3 5 Water 16.7 100.00 Composition C - Colorless latex additive ~or disPersin~
medium Vinyl acetate-acrylic copolymer emulsion, 55%
; solids (Amæco Res. 3011, American Mineral Spirits Co. Division, Union Oil Co. of California) 56.4 Maleic adducted linoleic ester of styrene allyl alcohol copolymer, 63.5% solution in water/
diethylene glycol monobutyl ether (R~-9069, Monsanto Co.) . 10.7 Ammonium hydroxide (28% NH3) 0.5 ~alc 24.1 Sodium condensed naphthalene sulfonate, 25%
solution in water (~omar D, ~opco Chemi¢al Division, Diamond Shamrock Chemical Co~)0.7 Water 7.6 100.00 Compositions D, ~- Sin~le colour dispersions of cationic dis~ersion ~hases in anionic dispersin~ medium.
D E
White Red Vinyl acetate-acrylic copolymer emulsion, 55%
solids (Amsco Xes. 3011, American Mineral Spirits Co.Div.~ Union Oil Co. of California) 38.4 36.6 ~itanium dioxide 19.2 9.1 Calcium carbonate - 9.1 ; Barium lithol red pigment dispersion, 53% solids - 4.8 ; Anionic phosphate ester dispersant, 25% active ingredients (Ulasperse 994-B, Ultra Adhesives Inc.) 0.08 0.07 Ammonium hydroxide (28% ~X3) 0.35 0.33 ~; Water 4057 4.2 . .
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---21~ _ White Red Cationic cellulosic derivative, ~/o solution in water (Polymer 3R-30M, Union Carbide Corp,) 18.7 17.9 Hydroxyethyl cellulose, ~J solution in water (Cellosize ~P-100M, Union Carbide Corp.) 18.7 17.9 ~otal cationic dispersion phase 100~00 100.00 ;10 Composition A _ 33 Composition B 33 ~he3e whi~e and red dispersions were prepared in the same manner a~ the white and black dispersions of Example ; IV, making latex dispersion phasçs of each colour, adding cationic and non-ionic cellulosic derivatives, and dispersing in anionic dispersing medium.
Composition F = White-red coatin~ comPosition for ; pointillistic effects. Parts b~ We_~ht Composition D 52 Composition ~ 28 Composition C 20 Mixing the coloured globule dispersions and colourless latex medium yielded a multicolour coating composition which could be brushed on a smooth sur~ace to gi~e a relatively thin film with adequate one-coat hiding pattern o~ fine grain type, clearly multicoloured as seen by the naked eye and substantially non-directional ,' in appearance.
EXAMPIE VIII
White-red coating composition for pointillistic effects;
Payload - vinyl acetate-acrylic copolymer emulsion.
Composition A - A~lg~ s~ yL ~n~ medium. PWrt~ bt'Y
Sodium carboxymethyl cellulose, 2% solution in water (CMC 7H, Hercules Inc.) 20.0 ~, .
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, ~ 0~ 79 5 g Parts b~
We~i~ht Cross-linked acrylic polymer emulsion, alkali ; swellable 9 20% dispersion in water (Acrysol ASE-108, Rohm & Haas Co.) 0.5 ~odium condensed naphthalene sulfonate, 25%
solution in water (Lomar~ D, Nopco Chemical Division, Diamond Shamrock Chemical Co.~ 0.2 Synthetic hectorite clay, 8% colloidal dispersion in water (~aponite ~, Laporte Industries ~td.) 8.0 Ammonium hydroxide (28% ~H~) 0.1 Water 71.2 100.00 Composition B - Colourless latex additive for dispersin~
medium Vinyl acetate-acrylic copolymer emulsion, 55%
solids (Amsco Res. 3011, American Mineral Spirits Co. Div., Union Oil Co. o~
California) 56.4 Maleic adducted linoleic ester of styrene allyl alcohol copolymer, 63.5% solution in water/diethylene glycol monobutyl ether (RF-9069, Monsanto Co.) 5.~
~ 25 An~onium hydroxide (28% NH3) 0.6 ,~ ~alc 24.2 Sodium condensed naphthalene sulfonate, 25%
solution in water (~omar D, ~opco Chemical Division, Diamond Shamrock ahemical Co.) 0.7 Water 12o2 100.00 Compositions C, D - Sin~le colour dispersions of cationic dispersion phases in anionic dispersin~ medium. C D
~hite Red Vi~yl acetate-acrylic copolymer emulsion~ 55%
solids ~Amsco Res. 3011, ~merican Mineral Spirits Co.Div., Union Oil Co. of California) 38.4 38.4 i -~
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~ 1~)8'79S9 _26-- White Red ~itanium dioxide 19.2 7.7 Red iron oxide - 11.5 Anionic phosphate ester dispersant, 2~/o active ingredients (Ulasperse 994-B, Ultra Adhesives Inc.) 0.08 0~08 Aqueous solution of mixed chelating agents, 26% active ingredient (Chelon 62 ~ Cowles Chemical Co.) 0.04 Trisodium N-hydroxyethyl ethylenediamine triacetate, 41% in water - 0.08 Ammonium hydroxide (28% NH~) 0.4 0.4 Water 4-38 4.34 15 Cationic cellulosic derivative, ~/o solution in water (Polymer 3R-30M, Union Carbide Corp.) 26 7 2 26 . 2 Hydroxyethyl cellulose, ~o solution in water (Cellosize QP-100M, Union Carbide Corp.) 11.~ 11.3 Total cationic base 100.00 100.00 Composition A 3103 31-3 White and red dispersio~s were prepared by stirring each cationic phase in the dispersing medium (Composition A).
After attaining approximately the desired particle æize, Composi-tion B was added with sufficient stirring to give a uniform mixture.
Composition B 31-3 31.3 ComF~lti n E - White-red coatin~ comPOSition for pointillistic effects.
30 Composition C 67 Composition D 33 Composition ~ could be brushed on a smooth surface to give a multicoloured film with adequate one-coat hiding, of substantially non-directional pattern, with many globules of 2 mm. or larger.

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--- 10~'79S9 -27~
~XA~E n~
Yellow-blue-green ceramic coating composition; Payload -ceramic frit.
Composition A - Ceramic dispersion phase.
Parts by ei~ht Porcelain ceramic frit (XF-30, Ferro Corp. ) 78~4 Tetrasodium pyrophosphate 0.05 ; Potassium carbonate 0.2 Water 21. 35 100.00 Composition B - Anionic dis~rsin~ medium Sodium carboxymethyl cellulose, ~/o solution in water (CMC 7H, Hercules Inc.) 18 Sodium polystyrene sulfonate, ~/o solution in water (VERSA-TL 700, National Starch and Chemical Corp.) 17 ; Colloidal silica, 3~/o solids in water J`. (Ludox SM-30, DU Pont de ~emours & Co.) 6 Crude natural water swellable clay~ 5%
dispersion in water 5 Water 100.00 Compositions C, D, E - Sin~le co_our dispersions of eationie phases in anionic dispersin~_medium.
C D
Composition A 7807 78-7 78.7 ~itanium dioxide (RA-10, ~itanium Pi~ment Di~ision, ~ Industries Inc.) 0.8 - -Yellow ceramic colourant (N-955, Pemco Division, SCM Corp.) 7.1 Blue ceramic colourant (N-1054, Pemco Division7 SCM Corp.) - 7.9 Green ceramie colourant (20101, ~erro Corp.) - ~ 7-9 .
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C D E
Quaternized vinylpyrrolidone copolymer, 15% solution in water (Gafquat 755, GAF CorpO) 1.6 106 1.6 Cationic cellulosic derivative~ 2%
solution in water (Polymer 3R 30M, Union Carbide Corp.) 11 o8 ~1~8 11~8 Total cationic base 100.00 100. 100.
Composition B - Anionic dispersing medium 23.6 23.6 23.6 The cationic phases of different colour were prepared by mixing the colourants with the ceramic dispersion phase, then addin~ the cationic polymers. Globular dispersions of each colour were then prepared by dispersing the cationic base in the anionic dispersing medium.
Composition F _ Yellow-blue-~reen ceramic coatin~
oompo~it~on Composition C (Yellow dispersion) 35.7 20 Composition D (Blue dispersion) 35.7 Composition E (Green dispersion) 14.3 Composition A (ceramic base) 14.~_ 100.00 Composition ~ was applied by doctor blade onto a primed steel plate, dried, and fused in a ceramic kiln at 1480F to give a multicolour ceramic coating in which individual colours were readily distinguishable by naked eye.
~XAMP~` X
Red-yellow paper composition; payload - paper pulp.
Oomposition A - Cationic dis~ersin~ medium Paper pulp, 10% dispersion in water 3 ; Cationic cellulosic derivative, 1.5%
solution in water ~Polymer 3R-30M, Union Carbide Corp.) 16.8 Water ~.2 ' 100 . 00 ' , ! `'`.
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B
Paper pulp, 1~/o dispersion in water 30 30 Sodium carboxymethyl cellulose, ~/o solution 5 in water (CMC 7H3S~, Hercules Inc.) 9 9 Colloidal magnesium aluminium silicate derived ~rom saponite, ~/o dispersion in water (Veegum T~ R, T. Va~derbilt Co., IncO) 10 10 10 Red iron oxide Yellow iron oxide Sodium polystyrene sulfonate, ~/0 ~olution i~ water (V~RSA-~L 700, National Starch and Chemical Corp.) 6 6 ` 15 Water 44 44 Composition D - Red_yellow paper comPosition Composition A 100 s Composition B 10 20 Composition C 10 Compositions B and C were added successively to Composition A, with stirring after each addition to break the coloured compositions into globules of desired size.
Composition D was applied by doctor blade -` onto a wire screen, and on drying at 180~ yielded a multicoloured paper sheet with red, yellow and white areas clearly distinguishable from one another. ~'he pattern could be modified by squeezing the formed sheet betwee~ steel plates before drying, which tended to deform the coloured globules.
~ XAMP~ XI
~ulticolour coating composition for application by brush or roller; payload - vinyl emulsion.

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' 1~'7gS9 -3o-Dis~ersion ~hase A - Cationic~ whiteParts by Wei~ht Vinyl Copolymer ~mulsion (Revacryl 105 from Revertex Ltd~) L~.7 ~itanium dioxide 6.3 5 ~xtender pigment 7.6 Cationic guar gum, paste in dispersant (Gendriv 162) 0.8 ~etrasodium pyrophosphate 001 Additives 0.1 Water 17.9 37.5 Dispersin~ medium B - Anionic Anionic colloidal clay (Laponite XLG) 0.5 Colloidal silica, water dispersion (Ludox AM) 2.5 15 Amorphous silica (Gasil 23) 4.4 Borax (chelating agent) 0~03 ~etrasodium pyrophosphate 0.1 Extender pigments 7-5 Water-miscible solvents 5.4 20 ~hickener 0.2 Vinyl Copolymer ~mulsion (Revacryl 105) 23.2 Additives 3 Water 18.37 100.00 25 Dispersion phase C - Cationic, tinted Dispersion phase a is as dispersion phase A, but containing sufficient coloured tinting pigment of desired shade to provide colour contrast with dispersion phase A.
Multicolour composition D
~he dispersion phases A and C are prepared in the usual manner ~nd added with high speed agitation in any de-sired ratio, preferably separately, to dispersing medium B, to form the multicolour coating composition.
~5 B
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Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A dispersion of globules of a first aqueous phase in a continuous second aqueous phase, character-ized in that the globules of the first aqueous phase are of sufficient size as to be visible to the naked eye and contain a macromolecular colloidal polyelectro-lyte that may be either cationic or anionic, the second aqueous phase containing an ionic colloid that is opposite in charge to that of the colloidal polyelec-trolyte in the first phase, the first phase being insolubilised by interaction between said ionic colloid and said colloidal polyelectrolyte into the said globules which may be subjected to substantial shear stress without subdividing.

2. A dispersion as claimed in claim 1, character-ized in that the ionic colloid in said second phase also is a macromolecular colloidal polyelectrolyte.

3. A dispersion as claimed in claim 1, character-ized in that a film-forming polymeric binder is present in the first and/or second aqueous phase.

4. A dispersion as claimed in claim 1, character-ized in that at least some of the globules of the first aqueous phase are coloured.

5. A dispersion as claimed in claim 1, character-ized in that dispersed globules of at least two different colours are present.

6. A dispersion as claimed in claim 1, character-ized in that the second aqueous phase is coloured.

7. A dispersion as claimed in claim 1, character-ized in that it is capable of being applied to a desired surface by spraying, brushing or rolling to define a decorative coating thereon without said globules sub-dividing during said application.

8. A dispersion as claimed in claim 1, character-ized in that globules of the first aqueous phase contain a dispersed ceramic material.

9. A dispersion as claimed in claim 1, character-ized in that the first and/or second phases contain a dispersed paper pulp.

10. An article carrying a coating formed by applying a film of a dispersion of globules of a first aqueous phase in a continuous second aqueous phase and drying or curing the film, characterized in that the dispersion is as claimed in claim 1.

11. A method of preparing the dispersion claimed in claim 1, which method comprises a) providing a first aqueous material con-taining a macromolecular colloidal polyelectrolyte that may be either cationic or anionic, b) intermixing said first aqueous material with a second aqueous material which contains an ionic colloid that is of opposite charge to the colloidal polyelectrolyte in the first aqueous phase, and c) subjecting the mixture to shear to sub-divide said first aqueous material into a plurality of globules.