Resin compositions comprising organoclays of improved dispersibility

Resin-containing compositions, e.g. unsaturated polyester or epoxy resin compositions, are prepared using an organoclay of improved dispersibility. The organoclay is prepared by suspending a smectite clay in water to form a fluid suspension; treating the suspension with a solution of an inorganic salt, the cation of which has a valency of at least two, the concentration of the salt being such as to flocculate the smectite clay substantially completely; mixing the suspension of the flocculated smectite clay with a quaternary ammonium compound, at least one of the four alkyl groups of which has from 10 to 24 carbon atoms; and dewatering the resultant product.

FIELD OF THE INVENTION 
This invention relates to organoclays of improved dispersibility in organic 
media and to their applications in resin compositions, particularly for 
coating and forming purposes. 
BACKGROUND OF THE INVENTION 
An organoclay is an organophilic cation-modified clay derived from a clay 
mineral, generally of the smectite group, for example a bentonite, 
montmorillonite, hectorite, saponite or the like, by replacing the 
inorganic exchangeable cations, which occur in the natural clay mineral, 
by organic cations, each comprising at least one hydrocarbon radical which 
has sufficient carbon atoms to render the surface of the cation-exchanged 
clay hydrophobic. 
Organoclays have been found to be very useful as thixotropic agents in 
organic media such as, for example, lubricating greases, oil-based 
drilling fluids, paints, varnishes, enamels and printing inks. However, an 
organoclay is, in general, difficult to disperse in an organic medium to 
form the uniform gel structure which is required to thicken, or to 
increase the viscosity of, the organic medium. Various means have 
accordingly been used to improve the dispersibility of an organoclay in an 
organic medium, including the use of a polar organic material, such as a 
low molecular weight alcohol or ketone, as a dispersing aid, and the use 
of an excess of a specially selected organic cation in the preparation of 
the organoclay. 
In Finlayson et al, U.S. Pat. No. 4,105,578, an organophilic clay gellant 
having enhanced dispersibility in organic systems is disclosed which 
comprises the reaction product of a methyl benzyl dialkyl ammonium 
compound wherein the compound contains 20 to 35% alkyl groups having 16 
carbon atoms, and 60 to 75% alkyl groups having 18 carbon atoms, and a 
smectite-type clay having a cation exchange capacity of at least 75 
milliequivalents per 100 grams of said clay, and wherein the amount of 
said ammonium compound is from 100 to 120 milliequivalents per 100 grams 
of said clay, 100% active clay basis. 
In Finlayson et al, U.S. Pat. No. 4,412,018, an organophilic clay gellant 
and methods of using and making the same are disclosed, which comprises 
the reaction product of an organic cation, an organic anion and a 
smectite-type clay having a cation exchange capacity of at least 75 
milliequivalents per 100 grams of said clay, such that an organic 
cation-organic anion complex is intercalated with the smectite-type clay 
and the cation exchange sites of the smectite-type clay are substituted 
with the organic cation. The examples of the patent illustrate the use of 
the organophilic clay in thixotropic unsaturated polyester compositions 
and in thixotropic coating compositions. 
In our application, Ser. No. 765,259 filed Aug. 13, 1985, there is 
described a method which improves the ease of dispersibility of 
organoclays in organic liquid compositions and avoids the need to provide 
high shear mixing equipment and the expenditure of the large amounts of 
energy which are required for the high shear mixing as disclosed in Ser. 
No. 727,022 filed Apr. 25, 1985. 
In particular, this method yields an organoclay which can be dispersed 
readily into unsaturated polyester solutions. Unsaturated polyester 
compositions containing various gelling agents are well-known. 
Additionally, it is known that in the preparation of glass fiber laminates 
of unsaturated polyester and the like, thixotropic gelling agents are used 
which allow for the ready mixing and spraying of these resins at high 
shear rates. At low shear rates, however, these gelling agents greatly 
increase the viscosity of the polyester, thus avoiding the drainage of the 
resin on vertical surfaces. 
One of the most widely used gelling agents for unsaturated polyesters was 
asbestos fibers. Asbestos fibers assisted in producing thixotropic 
polyesters without significantly affecting resin clarity. However, in the 
past several years, it has become recognized that the use of asbestos 
under the usual manufacturing conditions is objectionable, because of its 
long-term adverse effects on health when inhaled. For this reason, the 
asbestos gelling agents were replaced by a silica aerogel. When about 1% 
of silica was dispersed in the resin, it provided effective thixotropy. 
However, such product is comparatively expensive, and because of low bulk 
density, presents storage and handling problems. 
Consequently, the art has turned to the use of organoclays as gelling 
agents. Conventional organoclays cannot be dispersed in unsaturated 
polyester solution. They must be predispersed in monomer styrene and the 
gel subsequently blended with the polyester. This extra stage is expensive 
and inconvenient. It also limits the amount of organoclay that can be 
incorporated, to levels which can be physically handled in styrene: above 
about 8 wt % the gels become unmanageably stiff. Hence there is a need for 
organoclays which can be stirred directly into polyester solution, like 
fumed silica. 
SUMMARY OF THE INVENTION 
The organoclay employed in the present invention is prepared by a method 
described in U.S. Ser. No. 765,259 which comprises the following steps: 
(a) A smectite clay is suspended in water to form a fluid suspension; 
(b) The aqueous suspension of the smectite clay is treated with a solution 
of an inorganic salt, the cation of which has a valency of at least two, 
the concentration of the salt being such as to flocculate the smectite 
clay substantially completely; 
(c) The suspension of the flocculated smectite clay is mixed with a 
quaternary ammonium compound at least one of the four alkyl groups of 
which has from 10 to 24 carbon atoms; and 
(d) The product of step (c) is dewatered. 
In step (b) the valency of the cation is preferably 3, and most preferably 
the cation is aluminum. If the valency of the cation is 3 the 
concentration of the solution of the salt containing the cation is 
preferably in the range of 0.001 M to 0.02 M. If, however, the valency of 
the cation is 2 the concentration of the solution of the salt containing 
the cation must be greater and is preferably in the range from about 0.2 M 
to 2 M. 
The suspension of the flocculated clay is preferably mixed with the 
quaternary ammonium compound in proportions such that there are present 
from 95 to 140 milliequivalents of quaternary ammonium cation per 100 g of 
dry clay. 
In step (c) the aqueous suspension of the flocculated smectite clay is 
preferably mixed with molten quaternary ammonium compound. The quaternary 
ammonium compound preferably has the general formula: 
##STR1## 
wherein R.sub.1 is a saturated or unsaturated alkyl group having from 10 
to 24 carbon atoms, R.sub.2 and R.sub.3, which may be the same or 
different, are each a saturated or unsaturated alkyl group having from 1 
to 24 carbon atoms or an aralkyl group having from 7 to 10 carbon atoms, 
R.sub.4 is an alkyl group having from 1 to 6 carbon atoms or an aralkyl 
group having from 7 to 10 carbon atoms, and X is OH, Cl, Br, NO.sub.2, 
CH.sub.3 SO.sub.4 or CH.sub.3. COO. 
Examples of such compounds are the benzyl methyl dialkyl ammonium 
chlorides, the dimethyl dialkyl ammonium chlorides, the benzyl dimethyl 
alkyl ammonium chlorides, the benzyl trialkyl ammonium chlorides and the 
methyl trialkyl ammonium chlorides, where the one or more alkyl group 
represents a mixture of hydrocarbon radicals derived from tallow having 
from 14 to 20 carbon atoms but in which C.sub.18 radicals preferably 
predominate (a typical analysis of such a mixture of hydrocarbon radicals 
contained in tallow is: C.sub.14 2.0%; C.sub.15 0.5%; C.sub.16 19.0%; 
C.sub.17 1.5% C.sub.18 66.0% and C.sub.20 1.0%). The hydrocarbon radicals 
may be partially unsaturated as in natural tallow or may be substantially 
completely saturated as a result of treating the tallow with hydrogen in 
the presence of a suitable catalyst. 
It has been found that these organoclays can readily be incorporated in 
resin compositions containing resins of various types, in particular, the 
commonly used alkyd resins, unsaturated polyester resins and epoxy resins. 
These organoclays are self-dispersing products for unsaturated 
polyester/styrene systems, aliphatic organic solvent systems and polar 
organic solvent systems. 
By means of the present invention, there can be provided a novel 
thixotropic cross-linkable unsaturated polyester composition which has 
unique rheological properties, for example, a high thixotropic index. 
DETAILED DESCRIPTION 
The organophilic clays of this invention may be used without the need for a 
styrene pregel. In particular, polyester compositions may be prepared by 
mixing the organophilic clay with the final liquid polyester mixture 
prepared from a liquid unsaturated polyester and unsaturated aromatic 
monomer. The final polyester compositions can then be cross-linked to 
produce coatings or glass fiber-reinforced laminates by methods well known 
in the art. 
In a typical procedure the liquid unsaturated polyester resin is mixed in 
conventional apparatus with an unsaturated aromatic monomer to prepare a 
solution having a solids content between about 30 and 80% by weight 
polyester. The organophilic clays of the invention can then be added to 
the liquid laminating resin. 
The unsaturated aromatic monomers of this invention are aromatic compounds 
to which is bonded one or more ethylenically unsaturated radicals such as 
a vinyl radical, substituted vinyl radical or an allylic radical. Suitable 
monomers include styrene, .alpha.-methyl styrene, divinyl benzene and 
allyl benzene. Styrene is preferred due to its effectiveness, wide use and 
availability. Such monomers are used in cross-linking the polyesters and 
also act as diluents to reduce viscosity. 
The unsaturated polyesters useful in preparing the thixotropic compositions 
of this invention are polyesters of a dicarboxylic acid and a diol having 
a major amount of olefinic unsaturation, preferably 10 to 75 olefin groups 
per 100 ester groups. The olefinic unsaturation is preferably derived from 
the carboxylic acid although the diol may be unsaturated. Typical diols 
are ethylene glycol and propylene glycol. Typical unsaturated acids 
include maleic acid, fumaric acid. Anhydrides of these acids are also 
commonly used. Such polyesters are made by conventional techniques of 
esterification as well known in the art. Generally, polyesters having 
molecular weights of from about 400 to 10,000 and acid numbers in the 
range of from 0 to 50 mg KOH per gram of resin are useful for preparing 
the thixotropic composition of this invention. 
The amounts of organophilic clay gellant used in polyester laminating 
resins can range from 0.25% to 10%, preferably 0.5 to 4%. Amounts larger 
than 10% may be employed but are not economical.

Practice of the present invention will now be illustrated by the following 
Examples, which however, are to be considered as merely illustrative of 
the invention, and not delimitive thereof: 
EXAMPLE I 
Organoclay samples were prepared by the following method: 
In each case, an aqueous suspension of bentonite was prepared by mixing raw 
Wyoming sodium bentonite in a blunger with sufficient water to form a 
suspension containing 10% by weight of the dry clay. The suspension thus 
formed was passed through a No. 300 mesh British Standard sieve (nominal 
aperture 0.053 mm) and the undersize fraction was diluted to about 6% by 
weight of solids with water and subjected to a particle size separation in 
an intermittent discharge, continuous centrifuge at a flow rate of 1 litre 
per minute. The fine fraction was then passed through an homogenizer as a 
pre-treatment to reduce particle size and increase uniformity. To a 500 g 
sample of the homogenized fine fraction, there was then added 120 g of a 
solution containing the calculated weight of either aluminum sulfate 
(Al.sub.2 (SO.sub.4).sub.3. 16H.sub.2 O) or aluminum chloride (AlCl.sub.3. 
6.H.sub.2 O) which was required to give the desired concentration of 
aluminum sulfate in 620 g of the suspension. The suspension was then 
subjected to stirring by means of a paddle mixer for 30 minutes while the 
suspension was heated to a temperature of 65.degree. C. 
There was then added to the heated suspension the calculated weight of a 
mixture of quaternary ammonium compound and water and isoproyl alcohol (in 
which form the quaternary ammonium compound is available in commerce) 
which was required to give the desired loading of quaternary ammonium 
compound on dry bentonite. The resultant mixture was then stirred in the 
paddle mixer for 30 minutes, filtered on a Buchner funnel, washed with hot 
water and dried for 16 hours at 60.degree. C. in an air-swept oven. The 
dry product was then milled to pass through a sieve of nominal aperture 
0.080 mm. 
Various organoclays were prepared according to the above procedure using as 
the quaternray ammonium compound either dimethyl di(hydrogenated tallow) 
ammonium chloride (2M2HT) or methyl benzyl di(hydrogenated tallow) 
ammonium chloride (MB2HT), different concentrations of aluminum sulfate 
being used in the preparation of the aqueous suspension of bentonite. 
Each organoclay was incorporated into an alkyd gloss paint composition 
which was prepared in the following manner. The following ingredients were 
first mixed together in the stated proportions by weight: 
______________________________________ 
Ingredient Wt. % 
______________________________________ 
Alkyd resin 20.0 
White spirit 8.25 
Calcium naphthenate 
0.9 
Titanium dioxide 29.8 
Methylethyl ketoxime 
0.2 
______________________________________ 
When the above composition was thoroughly mixed the following materials 
were added under stirring in the following order: 
______________________________________ 
Ingredient Wt. % 
______________________________________ 
Alkyd resin 33.0 
White spirit 6.25 
Lead naphthenate 0.8 
Cobalt naphthenate 
0.3 
Organoclay 0.5 
Total 100.0% 
______________________________________ 
The calcium, lead and cobalt naphthenate are drying agents and the 
methylethyl ketoxime is an anti-skin agent. 
Each paint composition was mixed for 15 minutes using Cowles blade of 
diameter 41 mm rotating at a speed of 2500 rpm. At the end of this time 
small samples were taken on a spatula and spread on a Hegman gauge. The 
size of the largest solid particles present in a significant proportion 
was read from a Hegman gauge. 
The said Hegman Gauge is used to determine the quality of the dispersion of 
solid particles in an organic liquid medium, and comprises a polished 
metal plate provided with a rectangular depression of tapering depth which 
varies uniformly from zero at one end to 100 .mu.m at the other end. A 
film of the organic liquid composition is spread evenly over the plate and 
a visual estimate of the coarsest particles present in the composition can 
be made. 
If a substantial number of relatively coarse (10-100 micrometer) particles 
are present in the composition a definite "front" will be observed which, 
when compared with a scale provided alongside the depression, indicates 
the size of the largest particles present. If only a few particles in the 
above size range are present these will show up as specks in the 
depression and may be counted. The particulate solid material in a paint 
composition should be dispersed to such an extent that no front is visible 
when a sample of the paint is spread on a Hegman gauge and only a very 
small number, if any, specks can be seen. 
Larger samples of the complete alkyd gloss paint compositions were allowed 
to stand for 24 hours and were then tested for viscosity at 21.degree. C. 
using a Brookfield Viscometer fitted with spindle No. 2 at 1 rpm. A sample 
of an alkyd gloss paint composition prepared in an identical manner but 
containing no organoclay was also tested for viscosity in the same way. 
For each sample of organoclay a "viscosity ratio" at 1 rpm was calculated 
according to the following formula: 
##EQU1## 
The results are set forth in Table I below: 
TABLE I 
__________________________________________________________________________ 
Milli-Equivalents 
Concentration of 
Gauge 
Quaternary Al.sup.3+ ions in 
Viscosity 
Size of 
Quaternary Ammonium Compound 
Aqueous ratio 
Largest 
Ammonium Compound 
per 100 g clay 
Suspension (M) 
at 1 rpm 
Particles (.mu.m) 
__________________________________________________________________________ 
2M2HT* 132 0.001 3.8 70 
2M2HT 132 0.005 3.6 40 
2M2HT 132 0.01 2.7 10 
2M2HT 132 0.02 n.d. 10 
2M2HT 132 0.05 2.9 20 
MB2HT** 122 0.001 n.d. 80 
MB2HT 122 0.0025 5.7 10 
MB2HT 122 0.005 4.8 10 
MB2HT 122 0.0075 4.1 10 
MB2HT 122 0.01 3.3 10 
__________________________________________________________________________ 
*dimethyl dihydrogenated tallow 
**methyl benzyl dihydrogenated tallow EXAMPLE II 
Further samples of organoclays were prepared according to the procedure 
described in Example I with different loadings of 2M2HT or MB2HT being 
used in each case. The concentration of aluminum sulfate in the aqueous 
suspension of bentonite was 0.05 M for each sample containing MB2HT and 
0.01 M for 2M2HT. Each organoclay was incorporated into an alkyd gloss 
paint composition having the same formulation as that in Example I, and 
each completed paint composition was tested on a Hegman Gauge for the size 
of the largest solid particles present in a significant proportion. 
The results are set forth in Table 2 below: 
TABLE 2 
__________________________________________________________________________ 
Milli-Equivalents 
Concentration of 
Quaternary Ammonium 
Al.sup.3+ ions in 
Hegman Gauge 
Quaternary Compound per 100 g 
Aqueous Size of Largest 
Ammonium Compound 
clay Suspension (M) 
Particles (.mu.m) 
__________________________________________________________________________ 
2M2HT 104 0.01 40 
2M2HT 115 0.01 25 
2M2HT 124.5 0.01 15 
2M2HT 131.5 0.01 10 
2M2HT 132 0.01 10 
2M2HT 134 0.01 5 
2M2HT 137 0.01 5 
MB2HT 102.5 0.005 70 
MB2HT 103 0.005 70 
MB2HT 114 0.005 80 
MB2HT 115 0.005 60 
MB2HT 122 0.005 10 
MB2HT 123 0.005 5 
MB2HT 123.5 0.005 10 
MB2HT 124 0.005 10 
MB2HT 135 0.005 10 
__________________________________________________________________________ 
EXAMPLE III 
Further organoclay samples were prepared according to the procedure 
described in Example I, except that the time for which the mixture of the 
suspension of the fine bentonite from the centrifuge and the solution of 
aluminum sulfate was stirred in the paddle mixer was different in each 
case. In each case there was used 135 meq. of MB2HT per 100 g of dry 
bentonite, and the concentration of aluminum ions in the aqueous 
suspension was 0.01 M. 
Each organoclay was incorporated into an alkyd gloss paint composition 
having the same formulation as that in Example I, and each completed paint 
composition was tested on a Hegman gauge for the size of the largest solid 
particles present in a significant proportion. Larger samples of each 
paint composition were also allowed to stand for 24 hours and were then 
tested for viscosity at 21.degree. C. using a Brookfield Viscometer fitted 
with spindle No. 2 at speeds of 1 rpm, 5 rpm and 50 rpm respectively. 
A sample of the same paint composition, but containing no organoclay was 
also tested in the same way. 
The results are set forth in Table 3 below: 
TABLE 3 
__________________________________________________________________________ 
Concentration of 
Al.sup.3+ ions in Hegman Gauge 
Viscosity 
Aqueous Mixing Time 
Size of Largest 
(mPa.s) at 21.degree. C. at 
Suspension (M) 
(min) Particles (.mu.m) 
1 rpm 
5 rpm 
50 rpm 
__________________________________________________________________________ 
0.01 7 20 2480 
1640 
960 
0.01 15 5 3040 
1920 
1000 
0.01 30 5 n.d. 
n.d. 
n.d. 
0.01 60 5 2640 
1680 
960 
Paint Composition Without 
5 560 
584 
578 
Organoclay 
__________________________________________________________________________ 
EXAMPLE IV 
In this Example, a series of further organoclay samples were prepared 
utilizing the procedure of Example I, except that various salts--both with 
monovalent and multivalent cations--were utilized. More specifically the 
salts utilized included sodium chloride, lithium chloride, ammonium 
chloride, calcium chloride, magnesium chloride, ferric chloride and 
chromium chloride. Various concentrations of the said salt solutions were 
utilized in accordance with the showing of Table 4. Each resultant 
organoclay was incorporated into an alkyd gloss paint composition having 
the same formulation as that in Example I, and each completed paint 
composition was tested on a Hegman Gauge for the size of the largest solid 
particles present in a significant proportion. The larger samples of each 
paint composition were also allowed to stand for 24 hours and were then 
tested for viscosity at 21.degree. C. using a Brookfield viscometer fitted 
with a No. 2 spindle at speeds of 1 rpm. The results are set forth in 
Table 4, which establishes that with monovalent salts, e.g., sodium 
chloride, or with divalent salts, e.g., calcium chloride, considerably 
higher concentrations are needed for Hegman dispersion. (It is found that 
with monovalent salts approximately a 2 to 10 M solution is required). 
Conversely, when the trivalent aluminum or chromium +3 ion is employed, 
much lower concentrations are required. While with chromium +3 ion good 
dispersion is obtained, chromium +3 ion is generally more expensive to 
utilize than aluminum ion and additionally chromium is less desirable to 
employ for practical reasons, in that chromium ion can under some 
conditions be a source of industrial pollution. 
TABLE 4 
__________________________________________________________________________ 
Hegman Gauge 
After 15 min. 
Viscosity at 1 rpm 
Viscosity 
Concentration 
Amine (largest 
after 24 hrs 
blank paint 
Salt 
(M) (130 meq/100 g) 
particles .mu.m) 
(cP) (cP) 
__________________________________________________________________________ 
NaCl 
2 2M2HT 3(60) 3280 960 
LiCl 
2 2M2HT 3(60) 3000 800 
NH.sub.4 Cl 
2 2M2HT 3(60) 2480 800 
CaCl.sub.2 
0.3 2M2HT 7(10) 2000 600 
0.5 2M2HT 7(10) 3040 840 
1.0 2M2HT 6(25) 2440 840 
MgCl.sub.2 
0.5 2M2HT 41/2(40) 
3680 800 
1 2M2HT 7(10) 1880 600 
2 MB2HT 7(10) 3400 880 
FeCl.sub.3 
0.05 2M2HT 51/2(30) 
2680 1000 
0.1 2M2HT 4(50) 2640 1000 
0.2 2M2HT 5(40) 2760 1000 
CrCl.sub.3 
0.05 2M2HT 7(10) -- -- 
0.1 2M2HT 7(10) 3040 1000 
0.2 2M2HT 7(10) 2800 1000 
__________________________________________________________________________ 
EXAMPLE V 
Organoclay samples were prepared by the following method. 
An aqueous suspension of bentonite was prepared by mixing raw Wyoming 
sodium bentonite in a blunger with sufficient water to form a suspension 
containing 10% by weight of dry clay. The suspension thus formed was 
passed through a No. 300 mesh British Standard sieve (nominal aperture 
0.053 mm) and the undersize fraction was diluted to about 4% by weight of 
solids with water and subjected to a particle size separation in an 
intermittent discharge, continuous centrifuge at a flow rate of 1 liter 
per min. The fine fraction was then passed through a homogenizer as a 
pre-treatment to reduce particle size and increase uniformity. To a 500 g 
sample of the homogenized fine fraction, enough water was added to make 
the organoclay reaction solids 2.3% by weight. To this was then added the 
calculated weight of aluminum chloride (AlCl.sub.3. 6H.sub.2 O) which was 
required to give the desired concentration of aluminum chloride in the 
suspension. The suspension was then subjected to stirring by means of a 
paddle mixer for 15 minutes while the suspension was heated to a 
temperature of 65.degree. C. There was then added to the heated suspension 
the calculated weight of a mixture of quaternary ammonium compounds and 
water and isopropyl alcohol (in which form the quaternary ammonium 
compounds are available in commerce) which was required to give the 
desired loading of quaternary ammonium compounds on dry bentonite. The 
resultant mixture was then stirred in the paddle mixer for 30 minutes, 
filtered on a Buchner funnel, washed with hot water and dried for 11/2 
hours at 60.degree. C. in a fluid bed drier. The dry product was then 
milled to the desired particle size. 
The various organoclays were prepared according to the above procedure 
using a mixture of quaternary ammonium compounds comprising 75 mole% 
dimethyl benzyl hydrogenated tallow ammonium chloride (2MBHT) and 25 mole 
% dimethyl di(hydrogenated tallow) ammonium chloride (2M2HT), different 
concentrations of aluminum chloride being used in the preparation of the 
aqueous suspension of bentonite. 
Each organoclay was milled to less than 0.250 mm. 1.5 by weight of each dry 
organoclay composition was incorporated into an unsaturated polyester 
resin composition using a laboratory stirrer rotating at 3,500 r.p.m. for 
15 mins. The resin was a rapid-curing, general-purpose unsaturated 
polyester resin, marketed by the Scott Bader Company Limited under the 
trade name "CRYSTIC 196"(CRYSTIC is a Registered Trademark). It is 
believed to be a co-polymer of ortho-phthalic acid, fumaric acid and 
propylene glycol, having a number average molecular weight of about 3,000. 
Cobalt octoate accelerator was added at 0.01% by weight at the end of the 
mixing time. Crystic 196 as received from Scott Bader is a 70 percent by 
weight solution of polyester resin in styrene. This is diluted to 54 
percent by weight polyester with extra styrene before use. 
The viscosity of the polyester resin composition containing the organoclay 
as a gelling agent, was measured using a Brookfield RVT Viscometer at 
spindle speeds of 0.5 r.p.m., 5 r.p.m. and 50 r.p.m. The data are shown in 
Table 5. Thixotropic Index ratios are also given. 
TABLE 5 
__________________________________________________________________________ 
##STR2## 
Concentration 
Milli-Equivalents 
of Al.sup.3+ ions 
Quaternary in Aqueous 
Ammonium Compound 
Suspension 
Viscosity, cp Thixotropic 
per 100 g clay 
M 0.5 r.p.m. 
5 r.p.m 
50 r.p.m. 
Index 
__________________________________________________________________________ 
110 0 8400 
1680 500 3.36 
110 0.001 11600 
2240 612 3.66 
110 0.0025 15400 
2760 596 3.97 
110 0.005 4200 
960 344 2.79 
100 0.0025 17000 
3000 724 4.14 
105 0.0025 24000 
4400 965 4.56 
110 0.0025 15000 
2880 708 4.07 
115 0.0025 8200 
1700 496 3.43 
fumed silica 
-- 17300 
2944 645 4.56 
at 1 wt % 
__________________________________________________________________________ 
EXAMPLE VI 
Each organoclay, prepared as described in Example V, was milled to less 
than 0.080 mm and incorporated into component A of a Two-pack Epoxy 
Enamel. 
This 19% pigment volume concentration white paint consists of 2 components, 
A and B. A is the base containing the epoxy resin; B is the polyamide 
curing agent solution. The ingredients are listed in their order of 
addition. 
To prepare component A the following were mixed: 
______________________________________ 
Ingredient 
Description/Function 
Supplier Grams 
______________________________________ 
Epikote 75 wt. % solution of 
Shell 157.0 
1001-X-75 epoxy resin in xylene 
Chemicals 
Solvent 65 wt. % Ethylene 47.5 
mixture glycolmonoethyl ether 
acetate; 15 wt. % 
Methyl isobutyl Ketone 
20 wt. % Xylene 
Beetle 640 
Urea formaldehyde 
British 7.0 
resin, a flow control 
Industrial 
agent Plastics 
(BIP) 
Nuosperse 657 
Dispersant Durham Raw 3.5 
Materials 
Titanium 149.0 
Dioxide 
______________________________________ 
The above ingredients were mixed in a water-cooled pot using a Cowles blade 
at 4,000 r.p.m. until a Hegman Gauge reading of &lt;10 .mu.m was obtained. 
The speed of the stirrer was reduced to 2,000 r.p.m. and the following 
added separately to the mix; the ingredients are listed in their order of 
addition: 
______________________________________ 
Ingredient Description/Function 
Grams 
______________________________________ 
Solvent mixture 
As above 42.5 
Organoclay 3.07 
______________________________________ 
The stirrer speed was increased to 4,000 r.p.m. and the ingredients mixed 
for 30 minutes at which time a Hegman Gauge reading was taken. 
Component B is separately prepared by mixing the following miscible 
ingredients. 
______________________________________ 
Ingredient 
Description/Function 
Supplier Grams 
______________________________________ 
Versamide 
Polyamide liquid Cray Valley 
56.0 
115 curing agent (amine 
Products 
value 210-220 mg KOH/g) 
Xylene 35.0 
______________________________________ 
Samples of the component A with organoclay and solvent were allowed to 
stand for 15 minutes and were then tested for viscosity at 21.degree. C. 
using a Brookfield RVT Viscometer at speeds of 1 r.p.m., 10 r.p.m., and 
100 r.p.m. 
A sample of the component A prepared in an identical manner but containing 
no organoclay was also tested for viscosity in the same way. Results are 
shown in Table 6. 
TABLE 6 
__________________________________________________________________________ 
Concentration 
Milli-Equivalents 
of Al.sup.3+ ions Hegman 
Quaternary in Aqueous Gauge 
Ammonium Compound 
Suspension 
Viscosity cp Reading 
per 100 g clay 
M 0.5 r.p.m. 
10 r.p.m. 
100 r.p.m. 
m 
__________________________________________________________________________ 
110 0 21000 
3950 1060 +50 
110 0.0025 28000 
4750 1200 30 
110 0.005 23000 
4100 1040 10 
100 0.0025 32000 
5400 1460 30 
105 0.0025 27000 
4600 1310 20 
No Organoclay 11000 
2200 660 10 
__________________________________________________________________________ 
It can be seen from the data in Example V and Table 5 that cross-linkable 
unsaturated polyester compositions having a thixotropic index of above 
about 2.5, preferably above about 3.0 and more preferably at least about 
4.0, can be obtained by means of the subject invention. It can also be 
seen from Example VI that the organoclay of this invention is readily 
dispersible in a polar organic solvent system.