INTRODUCTION
THICKENER N 10 is an APEO free acid-containing, crosslinked acrylic emulsion copolymer.
When the emulsion is diluted with water and neutralized with a base, each emulsion particle swells greatly.The emulsion clarifies under these conditions and becomes highly viscous. Once neutralized,
solutions of THICKENER N 10 cannot be reverted to emulsion form as a reduction in pH will
precipitate the polymer. Solutions of THICKENER N 10 salts are more similar in properties to
solutions of natural gums or higher viscosity grades of watersoluble cellulose derivatives than are
other grades of acrylic thickeners. Solutions are prepared for use rapidly since neutralization
occurs instantancously with a variety of standard bases.Handling is greatly simplified compared
to that necessary with powdered natural or synthetic gums. It is possible in specific cases to
incorporate THICKENER N 10 into a latex emulsion or other suspension without preneutralization as
first determined ona laboratory basis.Solutions of THICKENER N 10 effectively suspend pigments,
abrasives and other finely divided solids.Unlike conventional thickeners, salts of THICKENER N 10
have no flocculating action; thickened latices remain free of any creaming tendency and aqucous
suspensions are free of sedimentation.
TYPICAL PROPERTIES
Properties of the emulsion
Solids % 28,0 ± 0,5
pH, when packed 2.0 to 4.0
Viscosity, as supplied 4,0 cps.
5 percent sodium salt 25,000 cps.
1 percent sodium salt 3,000 cps.
Specific gravity, as supplied 1,054 at 25 ° C.
Appearance Milky liquid
Colloidal charge Anionic
The tendency of THICKENER N 10 to foam when rapidly agitated may be controlled effectively with
0.1 percent Nopco 1497V, based on THICKENER N 10 as supplied.Other defoaming agents may
have advantages for some applications. THICKENER N 10 is a stable emulsion,resisting mechanical
shear such as would be encountered during bulk handling or in high-speed mixing equipment.
Freezing or addition of soluble iron, copper or multivalent cations to the emulsion may cause
precipitation of polymer solids.If the emulsion is accidentally frozen and settling of the polymer
is evident, the product is recoverable in form by diluting it with water and adding alkali to form the
salt solution.
NEUTRALIZATION OF EMULSION
The reaction of THICKENER N 10 with a base analogous to a weak acidbase titration. THICKENER N 10
has a buffering affect, since pH changes only slightly until the polymer is full neutralized at a pH of
approxi mately 8.O. The rate of reaction between THICKENER N 10 and a base is rapid. The time
required for complete neutralization is essentially the same as that necessary to obtain intimate
mixture of the emulsion with the base solution. In stoichiometric calculations, THICKENER N 10
solids have effective equivalent weight of 218.
The following simple precautions should be followed when THICKENER N 10 solutions are being
prepared.
Adding a base to THICKENER N 10 as supplied will cause an unworkable gel to form immediately.
Five percent total solids appears to be the maximum concentration for solutions which can be
readily handled.Heating THICKENER N 10 solutions in the presence of excess base, pH 10 or higher,
is undesirable since change in properties may occur. When a base is mixed with dilute
THICKENER N 10 agitation should be adequate to disperse the material uniformly.To decrease foam
or occlusion of air, however, the rate and duration of agitation should be held to a minimum.Any of
the following commercially available bases may be used satisfactorily with THICKENER N 10