Note: Descriptions are shown in the official language in which they were submitted.
53~7
The present invention relates to a method of
preparing a s-table suspension of micronized solid particles
in an oil-in-wa-ter emulsion. This method thus provides a
stable suspension of solid particles in a low-viscosity
liquid. The invention will be explained in greater detail
below with reference to penetrating pigmented stains for
protection of wood and wood products, said stains showing
no tendency or only a slight -tendency towards strati~ication
or sedimen-tation of the pigments or other suspended solid
particles, but may also be applied for example in the
A` preparation of pigmented paints, abrasives, ~ili~h~
agents, cleaning agents, etc.
~' ' .
When applying stain to a porous surface, such as
a wood surface, one of the conditions of obtaining good
penetration is a relatively low viscosity of the liquid
compared to the rate of evaporation.
In practice, a short drying time is desired, and
the absolute viscosity must consequently be low. If the stain
is coloured wholly or partly by means of pigment particles,
these particles will precipitate on standing according to
Stokes' law which applies approximately to the filed which is
interesting in practice, i.e. that the rate of sedimentation
is a function of particle size and viscosity. This implies
that the stain must be strongly stirred before use, and such
compositions are therefore usually sold in buckets and
similar containers offerings good s-tirring possibility. If
the stain is not sufficiently stirred, colour faults will
-2-
. .... .. . . . .. .. , . . . . . . . ..... ~. ...
~ ~ ~;253'~
occur with regard to the tint and colour intensity when the
product is used.
It is known to obviate this problem in several ways:
The simplest me-thod is a reduction of the particle size to
colloidal dimensions whereby the sedimentation will be
insignificant even after long periods of time. Said method
is only applicable to specific expensive products as the
preparation of such a pigment dispersion is very costly.
Another, widely used method is flocculation of the pigmen-t by
addition of so-called "anti~settlingagents", like various
polar substances. By said method sedimentation is not
eliminated, but the sediment will be of such a nature as to
be particularly easily stirred up again. In extreme cases '
the pigment is ~locculated so strongly that the produc-t may '
,even be sold in cans requiring only bri~ shaking be~ore use.
By said flocculation of the pigment, however, the treated
sur~ace gets a grainy, unattractive appearance and the
actual penetration possibilities o~ the pigment are greatly
reduced.
A third possibility which is also used is to render the
A~ è sh~r
viscosity dependent on ~h~ force and time by addition o~
agents producing the rheological property named thixotropy 9
such as polyamide derivatives, colloidal silicic acid, etc.
for types of stain based on organic solvents. In this manner
viscosity may be kept hlgh on stan_ing while attaining the
--3--
... , . . , . . , . .. . ,, ... ... . , : . . . . . ..
3~ :
low value favourable -to the penetration at the very moment
of application and for a very short period thereafter. This
method, however, is limited to the cases where very high
shear forces arise during the application process, for
example in applica-tion by brush, and provides no possibility
o~ obtaining sufficiently deep penetration, as the lowering
of viscosity is in practice of very short duration.
It is the object of the present invention to provide a method
that does not suffer from the above-mentioned drawbac~s
and where, as far as stains are concerned, a produc-t having
good penetration ability and good protective effect can be
obtained, said product showing no appreciable tendency
towards stratification or sedimentation of the pigment even
on prolonged standing. More generally, it is the object of
the invention to provide stable suspensions of micronized
solid particles in the oil phase of an oil-in-water emulsion
without noticable tendency towards sedimentation.
This object is achieved by the method according to the
invention which is characteristic in tha-t the micronized
solid particles are ground in an oil phase in the presence
of one or more dispersion aids capable of rendering the
surface of the particles oleophilic and one or more sterical
and/or electrostatically stabilizing dispersion agen-ts to
obtain a stabilized suspension, after which said suspension
is emulsifiéd in an aqueous medium in the presence of one or
more emulsifiers of a -type that does not affect the stability
of the oil phase product by said dispersion agent or agents
1~<~
and said dispersion aid or aids. Thus, the particles are
incorporated and re-tained in the internal phase of a stable
oil-in-water emulsion whose external continuous phase is
thus composed of a liquLd of low viscosity.
.
It has thus surprisingly been found that partly by imparting
suitable oleophilic surface properties to the particles and
partly by providing suitable steric and/or electrostatic
forces between the particles and between the particles and
the bo~dary layer of the water phase of -the emulsion, stable
suspensions may be obtained showing no tendency or only an
extremely slight tendency towards sedimentation of the
particles on standing.
Methods having, on the face of it, certain points of similarity
to that described, but proving on close analysis to display
decisive differences and which especially do not aim at or
lead to products having the long-term stability obtainable
by the method according to the invention are described in a
number of publications:
German Offenle~un~sschrift No 22 12 521 describes a method
of preparing an electrophoresis bath in emulsion form in
which i.a. a pigment suspension in a water-dissolved
completely neutralized carboxylic acîd is added to the bath.
However, the measures stated aim at re-taining the pigment in
the water phase, and the method is not aimed at the preparation
of products wlth long-term stability.
5--
... ,, ......... .. .. . . .... . . . . ~. ~ .. ~ ..... . ... .... . .
Swedish Paten~ ,292 teaches a method of preparing resin
emulsions applicable for example as glue or for fixation of
pigments on -textiles. In Example 5 copper-ph-thalocyanine blue
is distributed in a concentrated emulsifier solution to
which is further added emulsifying agent, wa-ter, and an amino
resin emulsion. Said emulsion, thus containing no pigment in
the internal phase of the emulsion as the amino resin emulsion
is prepared and added separately, is further thickened by
an o/w emulsion of petrol in an emulsifier solution of the
kind mentioned above. Neithe-r in this case must the pigment
be expec+ed in any way to become incorporated in -the emulsion
internal phase. The features characteristic of the inventi~n
are thus not at all present here.
Swedish Paten-t No 135~66I teaches a me-thod of preparing an
emulsion concentrate which must be thinned immediately before
use, -and the long-term stability is consequently unimportant.
More exactly9 the object is to prepare emulsions where
water-insoluble protectants are dissolved in -the internal
.,
phase by a me-thod which endeavours -to eliminate their
possible negative impact on the emulsion stability on account
of interaction with the external phase by means of a delica-te
stepwise correction for these interactions.
The possibility of dispersed active substances is nowhere
described more specifically, and there is no mention os the
conditions of possibly stabilizing a substance in the internal
phase agains-t sedimen-tationO Hence, there are no points of
similarity to the characteristic features of the invention.
--6--
- .. . ~ .. , .. . ... , .. , .. , ~ .
5~3~7
German Offenle~ungsschrift No ?2 56 757 discloses an
emulsion which is particularly applicable as spray and which
may be of the water-i.n~oil -type as well as -the oil-in-water
type, particles of a substance wi-th antibacterial,
insecticide, herbicide or vegetation-modifying activity being
dispersed in one phase.
These liquids are ostensibly more stable than known products
of the same kind, however their stability has only been
documented for ~8 hours, and it is particularly emphasized
that the products are readily redispersible in contrast to
the known products.
The specific feature of the spray is partly the adjustment of
the density ratio and volume ratio between the phases
within precisely defined limits, and partly the selection of
a suitable non-ionic surfactan-t which is hydrophobic or
hydrophilic, depending on whether the particles are desired
to be present in the oil phase on in the water phase.
The possibility of establishing in this way, for particles of
substances of the type mentioned, a stability or at least
redispersibility sufficient for the purpose of application
cannot be precluded, but the tests of the applicant have
pro~ed tha-t said measures are quite inadequate for a long-
term stability of pigmented oil-in-water emulsions.
Thus, none of the above-mentioned publications mention the
combination characteristic of the method according to the
.. ,, , .. . . . . ~ ~ , .. . . . . , . .. . . . . . . . . , . ~ ... . ... . . .... ... .. .
*~ 7
invention of a dispersion aid capable of rendering the
particle surface oleophilic, a dispersion agent capable o~
stabilizing -the internal phase of -the emulsion, and an
emulsifier system compatible therewith which is capable of
stabilizing the emulsion i-tself.
In an oil-in-water emulsion of the kind described in the
present invention -the retention of the particles in the
internal phase and hence the stability of the suspension
may be obtained, according to the invention, more specifically
in the following manner:
To render the particles, for example the pigment particles,
oleophilic, i.e. they are ~ by oil than
by water, they are ground according to the invention in the
presence of suitable surfactants so tha-t they are brough-t
into said oleophilic state, which is a condition of the
actual incorporation into the oil phase.
.
In this place and in the following these agents are called
dispersion aids and may also, as far as pigments are
concerned, be called pigment wetting additives
According to the invention this may be effected by treatment
with one or more surfactants selected from the group of
non-ionic agents, such as alkyl polyethoxylates and alkyl
arylpolyglycol ethers; ampholytic agents, such as electron-
neutral salts of cation-active groups, e.g`. salts of fatty
amines with fatty acids or polycarboxylic acids, anion-active
agents, such as ~atty alcohol sulphates, sulfimides, alkyl-
arylsulfonates, especially alkylbenzene sulfonates and
alkyl naphthalene sulfonates, phosphate este~s, metal
naphthenates and metal salts of fatty acids; and cation-activ~
agents, such as quaternary ammonium compounds, alkylimidazole
salts and lecithin. These agents may also impart to the
individual particles an electric surface charge which will
contribute, if the original potential (zeta potential) of the
particle is not sufficiently great, to an anti-flocculating
effect owing to electrostatic repulsion. Thus, for example,
the pigment particles from the preparatory process or the
storing are often surrounded by a water film which must be
displaced at the grinding process in the presence of the
urfactant or surfactants to obtain good dispersion. In
a~e~
addition to this ehff~ge'of the surface properties of the
particles, the formed suspension of particles in the oil
phase may be further s-tabilized according -to the invention
by adding to the oil phase during the grinding agents
producing electrostatically active forces between the particles~
These may be selected from the same types as the above-
mentioned dispersion aids imparting oleophilic properties,
apart from the non-ionic.
It has been found, however, that the best stability o~ the
~SF~n~o~
~pon~i~n is obtained if adding to the oil phase during the
grinding oll-soluble agents which may also perform steric
stabilization. Such agents are for example surface active
soluble polymers with polar character, such as polymers of
oxidized, unsatura-ted fa-tty acids and esters or ethers
.
,., ~ ... ,,., ,,.,, ~. . ... . ... .... ... ........ .
`
3 7
thereof, partly polymerized esters of polycarboxylic acids,
such as alkyds, and s-tyrene-, isocyanate- and silicone-
modified ~arieties hereof, acryl-modiied and/or epoxidized
oils and resins, aldehyde condensation products with amines
and/or phenols, and polyethers a~ld polyvinyl derivatives.~It
has been found that e~ective s-tabilization is generally
first observed in polymers having a molecular weight of
about 1500 and increases with increasing molecular welght
up to about 10,000, after which the effect may diminis'n.
It should be noted that a number of the said types of sur-
factants perform both electrostatic and steric stabilization,
just as they may affect the particle surface itself, and
according to circums-tances -the same or several di~feren-t
surfactan-ts may therefore be used in addition to the
dispersion aid.
The concrete selection of surfactants depends i.a. on the
type of particles and the desired end product and may b~
determined by the person skilled in the art through tests. A
preferred combination in the preparation og pigmented stains
is a dispersion aid containing a hydrophobic group of cation-
active character, such as an amine, possibly in the ~or.m of
an amine salt, especially wi-th a hydrophobic anion (electron-
neutral salt), or in the form ofcn amine ester, such as a
lecithin, in combination with a sterically s-tabilizing surface
polymer mentioned above.
.
It is of vital importance to the favourable progress of the
--10--
, ~ . ... ..... .. . . . . . . ... .. .. . .. ... . . . . . . . . . . . . . .. . . . . .
3'~
of the method that -the particles are incorporated in a stable
emulsion. This stability is provided by addition of one or
more emulsifiers which produce steric and/or electrostatic
forces between the individual particles of the internal phase
(the oil phase) of the emulsion. In this connection it is of
vital importance that said stabilization of the emulsion is
not effected at the expense of the stability of the suspension
in the internal phaseJ and it is therefore necessary to
select emulsifiers that do not affec-t -the stability of the
oil phase produced by the dispersion agents and dispers~on
aids.
These emulsifiers, which may be of ionogenic or non-io-nic
type, can be added to one or both phases o:E the emulsion. As
far as ionogenic (cationic or anionic) types are concerned,
the electrostatic repulsion between the internal phase drops
is of substantial importance to the stabilization, while -the~
effect of non-ionic types depends primarily on steric repulsion
and is extensively pH-independent. The stability is further
affected by the distribution of the surfactant between the
two phases, and especially in -the case oi non-ionic types
a so-called HLb value (hydrophilic-lipophilic balance) is
often calculated for selection of the emulsifier which is
best suited for a given type of oil.
To obtain electrostatically activei forces in the stabilization
of the emulsion there may be added one or more surfactants
acting in the external phase and in the boundary layer to
the internal phase and selected from the group of ionogenic
-11-
.
emulsifiers and protective colloids, such as alkyl- aryl- and
alkylsulfo~ates, amine and metal salts hereof, such as
~4 IGIU~ IKYI2~I ~ /40n~S~
1l~ar~aæulfonates, carboxylic acids and polycarboxylic
acids and their salts (soaps), such as polyacrylic acid salts
with ammonia, amines and alkali metals, polyvinyl carboxylic
acids and partial esters :andtor salts thereof, cellulose
derivatives as well as polycondensed inorganic acids and
salts hereof, such as sodium hexametaphosphate and lithium
polysilicate.
To obtain sterically acting forces when stabilizing the
emulsion there may be added one or more ionogenic surfactants
of the type described above under electrostatic stabilization
and/or non-ionic agents, such as fatty acid- and fatt~ alcohol
polyglycol ethers, polyethoxylated alkyl phenols, polycarboxylic
acid esters and ethers, such as fatty alcohol succinates,
sorbitol esters and ethers, sorbitan ether polyethoxylates, .
polyvinyl alcohols, polyethylene oxide and ethers and esters
hereof as well as cellulose derivatives, such as hydroxyethyl
cellulose.
. .
It has been found that a combination of a non-ionic emulsifier
of the correct HLb value (for example of the alkylphenol
polyethylene oxide adduct type) added to the internal pnase,
and a minor amount of anionic surfactant of the protective
colloid type, for example a polyacrylate or a polyvinylmaleinate,
added to the external phase is particularly suitable for stab-
ilization of the emulsion itself as it functions satisfactorily
for example in the suspension of pigmen~ts in the in~ternal
. -12-
phase of emulsions of vegetable oils and their synthetic
analogs or derivatives thereof and does no-t affect the
particle s-tability in the inner phase adversely. Said anionic
component may also act to adjust a suitable viscosity and
for chelation of heavy metal ions ~Jhich may otherwise as
contaminants destroy the electrosta-tic stabilization, however
these functions may also be performed by separate components
o~ cationic, anionic or non-ionic na-ture, such as
sodium tripolyphosphate.
To improve stabili-ty, especially when the suspension is
employed in highly diluted state involving a risk o~
stratification in the case of great differences in density,
there may also according to -the invention be added to the oil
phase one or more density-equalizing agents, including light
liquids, such as aliphatic and aromatic hydrocarbons, and
heavy liquids, such as halogenated hydrocarbons, for exarnple
ethylene dichloride, tris-2,3-dibromo propylphosphate and
chloro paraffins. It is also possible to add solid substances,
for example light substances, such as wax and microscopic hollow
glass balls (microballoons), and heavy substances, such als solid
chloro paraffin and antimony trioxide. These may ser~e at the
same time as flameretardan-ts.
Applicable pigments are ~or example oxides and insoluble salts
of earth alkali metals and metals in the transition series,
for example iron oxides, chromium oxides, zinc oxide, barium
sulphate, titanium dioxide, calcium carbona-te, aluminium
and magnesium silicate; other oxides and elements, ~or
-13-
~ . ...... , .. , .. .. . . . . ., ., , .. . ..... . . . . . , . . ., . , , . . ~
~ ~P ~.33'~
example silicon dioxide, carbon black, aluminium powder and
zinc dust, as well as organic compounds, ~or instance
heliogen green, phthalocyanine blue, beMzidine yellow
and perylene red. The type of pigment, however, is not
critical to -the invention.
Finally, o-ther protec-tan~s of various kinds may be added
to the oil or water phase, and -these may for exampLe also
be in -the form of micronized solid particl.es, for instance
biocides, such as fungicides, for example tetrachloroi.so-
phthalonitrile, copper-8-hydroxyquinoline, -tributyl -~in oxide
and derivatives thereof; preservatives, such as sodium
pyridin-thion-l and Z,2 dibromoglutarodinitrile;
insec-ticides, such as lindane or endosulfane, IR-reflecting
agents and specific W -absorbing agents, just as oil soluble
pigment binders may be added to the oil phase, for instance
oxidative drying, possible modified oils. However, it has
surprisingly been found that the requirement for ~ ~ c;~ic
W -absorblng agents in the pigmented stains described is
very small as they cause extremely good penetration and
distribution of the pigment in the trea-ted wood sur~aces.
1~
To the water phase can be added water soluble or water
dispersible binders, for example polyacryla-te dispersions,
styrene-butadiene-polymer dispersions or polyvinylacetate
dispersions. If desired, there may also be added an oxidation
catalyst (siccative) which is complexed in a form so that
the equilibrium concentration of -the free catalyst in -the
external phase is so small tha-t the stabilizing system of
the emulsion is not affected noticeably hereby, and, if
desired, a s-tabilizer and/or an antioxidant to stabilize the
siccative.
The stable pigment suspensions prepared according to the
invention present -the additional advantage that they are well
suited for obtaining reproducible colour -tints. ~en co-
grinding pigments of differen-t colours in the oil phase a
co-~locculation has previously been observed, which impedes
a precise and reproducible shading. It has been found that
by mixing finished pigment suspensions of the type described
as well as by grinding toge-ther the pigments in the oil phase
by the method according to the invention, this co-floccula-tion
is eliminated, whereby a desired tint can be obtained in a
simple manner.
~' ' ' .
The mixture proportion between the constituents may vary
within wide limits depending on the desired end product and
not least on the kind of solid particles~
The oil-in-water emulsion may thus contain Prom 1 to 70 percent
by weight of oil, but will usually contain from about 20 to
30 percent by weight.
-15-
~ i7
For preparing, by way of example, a pi~mented stain, a paste
of the following composition will generally be ground first;
1 - 75 parts by weight of pigment
0.1-10 " " " " dispersion aid (pigment wetting agent)f
5 - 45 " " " - " dispersion agent tstabilizer)
0 - ~5 " " " " density-equalizing agent
the sum of the consti-tuents being 100 parts by weight.
For 50 parts by weight of this paste the following is sub-
sequently used:
.'
0 - 650 parts by weight of pigment binder
10 - 50 " " " " emulsifier (stabilizing agent ~or
the emulsion)
0 - 5 " " " " siccative and stabilizer -therefor
0 - 10 " " " " biocides and other secondary
materials.
This oil phase is emulsified in a water phase which may contain:
Il
0.1 - 50 parts by weight of stabilizer which may also perform
other functions (calculated as
active substance)
0 - 400 " " " " pigment binder, however not
exceeding 50 percent by weight
of the water phase,
0 - 10 " " " " biocides and other secondary
materials
as well as demineralized wa-ter up to 1000 parts by weight.
The in~ention is illustrated in greater de-tail by means of
the examples stated below:
-16-
37
EXAMPLE 1
Preparation of a pigmen-ted stain.
By dispersion on a pearl mill there was prepared an orange
paste by grinding 40 parts by weigh-t of transparent iron oxide
red (e.g. "VN 188", which is an orange hydrophilic pigment
sold by Siegle & Co.), 5 parts by weight of dispersion aid
(pigment wetting agent) e.g. "Disperbyk", which is an electro-
neutral salt prepared by reacting an alk~lol amine salt with
a polycarboxylic acid, sold by ~yk-Mallinckrodt, and 55 parts
by weight of soybean oil alkyd having an oil length of 65%
(sterically stabilizing dispersion agent for the pigment).
The dispersion took place at ambient temperature to a particle
size of max 20 /u.
50 g of this paste was mixed at ambient temperature for about
10 minutes with 200 g of 100 percent (solvent-free) llnseed;
oil alkyd having an oi1 length of about 80% which acts as
binder, 12 g of nonylphenoldodecaethoxylate (sterically
stabilizing non-ionic emulsifier), 1.2 g of cobalt naphthenate
( 6% Co - siccative), 0.8 g of a 38% solution of o-phenanthroline
in butyl glycol, sold by Vanderbilt Co. under the trade name
"Activ 8'~(stabilizer for siccative against hydrolysis) as
well as 2 g of methylethylketoxime (volatile antioxidant
acting as anti-skinning agent).
The 266 g mixture thus obtained, which may be regarded as a
fluid oil paint~ was dispersed at ambient temperature for
about 10 minutes in a mix-ture of 210 g of demineralized water
k
--17--
Z53'7
and 30 g o~ 15% polyvinylmaleic acid alkylglycolesterammonium
salt ("Thickner LN"), which is an anion1c stabilizer ac-ting
also as chelating agent and thickener and which was ~irst
mixed for about 5 minutes with another 60 g of demineralized
wa-ter. By said process there was obtained 566 g of pigment
dispersion having the character of anjemulsion paint to which
was added while stirring 434 g of demineralized water, to
which biocides and other protective agents rnay have been
added.
The stain (1000 g) thus obtained has at 20C a viscosity of
12 cP, pH 7.8, specific gravity 1.083. It is easily prepared
and at low cost, it has excellent penetration ability when
applied to wood surfaces and causes no air pollution in use.
It is stable on standing and shows no -tendency towards sedi-
mentation of -~he pigment, even after a storing period of: 14
months. The stain also has excellent freeze-thaw sta~ility.
For example, no product changes were observed after a standard
test comprising 3 freezings to -18C with in-termediate thawings.
In the same manner stains have been prepared using pigments
with other colours, such as "VN 088", yellow iron oxide
pigment and "VN 288" red iron oxide pigment, carbon black
and phthalocyanine blue, and other dispersion aids, such as
"Texaphor 96~", electro neutral pigment wetting age~t~
and lecithin, as well as other dispersion agents, such as
tall oil alkyds. Stains of the same excellent qualit~ were
obtained.
-18-
,, .. , . , . ~ . . .. ,, . . ,, .. . .. . ., .,, . . . , , .... ... . ... , , ... ... ... . , , . , . . . , .
. . , , ~ ... . , . ,, , ~ . . .... . .. . . ... .
By way o~ comparison identical stains have been prepared,
the dispersion aid characteristic of the invention, however,
being omitted. In all cases the pigments were precipi-tated
a~ter s-tanding for a short period.
.
The protective e~fect of a number of stains prepared as s-tated
above for treatment of wood surfaces has also been tested.
Under accelerated test conditions as regards weather -the
products described have exhlbited a surprisingly high degree
of weather resistance and have i.a. proved to be superior to
current types o~ stain on alkyd-solven-t base as well as on
acryl dispersion base under otherwise identical condi-tions
as regards degree o~ pigmentation, concentration of binder,
etc.
EXAMPLE 2
Preparation of a pigmented stain.
By dispersion on a pearl mill a black paste was prepared from
15 parts by weight o~ carbon black ("Prin-tex 300"), 4 parts
by weight of bentonite (thickener, 10% in white spirit), 1
part by weight of dispersion aid ("Disperbyk"~, 35 parts by
weight of linseed oil alkyd (dispersion agent), and 45 parts
by weigh-t o~ white spirit (density-equalizing gent3.
50 g o~ this paste was treated analogously with the paste
prepared in Example 1, and there was obtained a stable stain
having a speci~ic gravity of 1.03, pH 7.8, and viscosity
12 cP. Said stain also showed excellent penetration ability
--19--
i~3~
and was stable even in case of great additional thinning.
EXAMPLE 3
A polish was prepared by grinding together 1 part by weight
of diatomite, 8 parts by weight of dearomatized white spirit
1 part by weight of alkyd, 0.1 parts by weight of linoleyl-
trimethylene diamine-dioleate (dispersion aid), Q.5 parts-by
weight of polyethylene glycol diolea-te (PEG 400-dioleate),
which was subsequently emulsified in 89.4 parts by weight of
water containing 0.0025 parts by weight o~ polyacrylic acid
ammonium salt "Acrysol ASE95" (anionic stabilizer). The
obtained odourless composition was stable on prolonged stand-
ing with no tendency towards sedimentation.
EXAMPLE 4
._ .
Preparation of a pigmented stain
15 parts by weigh-t of black pigment ("Printex 300") were ground
analogously with Example 1 with 37.3 parts by weight of tall
oil alkyd "S 84" (sterically stabilizing dispersion agent) 7
prepared by esterification of-tall oil fatty acids with
pentaerythri-tol and 11% of isophthalic acid, 2 parts by weight
of purlfied soybean lecithin (dispersion aid), 3 parts by
weight of alkylphenolpolyglycol ether ("Wasc", sold by Berol
Kemi)~ 6 parts of Bentonite paste (10% bentonite, 85% white
spirit and 5% ethanol), 1.5 parts of methylethylketoxime and
35.2 parts of white spirit ("Varnolene").
r~l e ~k
.
-20-
~ - - - - ........ .. ... .. .
Analogously, a blue paste was prepared from "Hostapermblau
BFL" (phthalocyanine blue) and the same constituents in
the same quantities except that there was used 44 parts by
weight of "Varnolene" and 28.5 parts by weight of "S 84".
0.35 parts by weight of this black paste and 4.65 parts by
weight of this blue paste were mixed in a Cowless dissolver
for about 10 minutes in 20 parts by weight of "S 84", 2
parts by weight of "Wasc", 0.4 parts by weight of methylethyl-
ketoxime, 0.25 parts by weight of "Co-activ" (which is a
mixture of 40 parts by weight of "Activ 8", cf. Example 1,
20 parts by weight of cobalt naphthenate (18 percent C0) and
40 parts by weight of butylglyco~) as well as 1.8 parts of
"N 54 D" which is a dispersion of 2,3,4,6-tetrachloroiso-
phthalonitrile in a gl col ether.
Further, 20.9 parts by weight of water, 0.2 parts by weight
of NH3 and 7.5 parts by weight of 33% "mickner LN" were
mixed for 5 minutes.
me first prepared mixture was then poured into said mixture
and was mixed for 8 minutes, after which 39.95 parts by
weight of water and 2 parts by weight of monopropyleneglycol
(freeze-thaw stabilizing agent) were added.
mere was obtained a dark blue pigmented stain having the
same excellent properties as obtained in Example 1.
`"I`;
