TAMOL™ SN Naphthalene Condensate
*Note: OROTAN™ SN is the trademark used outside the U.S. TAMOL SN is the identical product marketed only in
North America.
Description
TAMOL SN is an efficient and economical dispersing agent with applications in many industries. It is the neutral
sodium salt of a condensed arylsulfonic acid. TAMOL SN is a tan, free-flowing granular material readily soluble in
water. The solubility is not appreciably affected by salts and acids.
Typical Physical Properties
These properties are typical but do not constitute specifications.
Solids, %
94.0
Sulfated ash, %
32.5
Na2SO4, %
8
Iron (as Fe2O3), %
0.006
Water insolubles, %
0.1
Alkalinity (as Na2CO3), %
0.4
pH, 2% solution
9.4
Bulk density (packed)
g/cc
lb/ft3
0.65
40.7
Screen analysis
% through 325 mesh
7
Flash point (Setaflash Closed Cup)
300ºF (149ºC)
TAMOL SN dispersant is slightly soluble in alcohols and in mixtures of alcohols. The addition of a polyhydric alcohol
to methanol or ethanol increases the solubility and the rate of solution. TAMOL SN appears to be infinitely soluble
in glycerol, ethyleneglycol, and diethyleneglycol, and the solutions become progressively more viscous as the
concentration increases. It is not soluble in oils and does not form oil-in-water or water-in-oil emulsions. TAMOL
SN is insoluble in most organic solvents, such as kerosene, toluene, ethoxyethanol, and carbon tetrachloride
(solubility 0.01–0.1% in these liquids).
Applications
Manufacture of Synthetic Rubbers
A very fine floc or “gum” tends to form during the emulsion polymerization of styrene-butadiene rubber, nitrile
rubber, and polychloroprene despite the presence of efficient primary emulsifiers. The addition of a secondary
dispersant, secondary emulsifier, or prefloc preventative, such as TAMOL SN, effectively minimizes the formation
of gum. A secondary dispersant is economically important, because excessive gum formation in the reactors and
in the styrene stripping column leads to frequent shutdowns for cleanup. The use of a secondary dispersant allows
rubber production facilities to operate for considerably longer periods of time before shutdown.
The presence of iron in secondary dispersants has very harmful effects on the production of synthetic rubber. The
specification for TAMOL SN allows no more than 100 ppm of iron (expressed as Fe2O3), and the actual iron
content is generally well below the specified maximum. The low salt content and subsequent high percentage of
active material is also important to the rubber producer.
Care must be taken in setting the level of secondary dispersant in dry rubber recipes. The quantity should be
enough to minimize the formation of gum during polymerization, but not so high as to interfere with coagulation of
the latex.
The use of secondary dispersants is even more important in recipes intended to remain in latex form than those
that are coagulated for the recovery of dry crumb. The levels of dispersant in latex applications are considerably
higher than in dry rubber recipes.
Recovery of Tall Oil in Papermills
TAMOL SN is widely used in papermills as the preferential treating agent in recovering tall oil by the continuous
acidification of soap skimmings. A typical process has been described by F. S. Sadler (to Sharples Division,
Pennwalt Corp.), U.S. Patent 2, 802, 845 (Aug. 13, 1957). The soap skimmings separating from the black liquor
consist of a mixture of emulsified tall oil soaps and lignin. In the presence of as little as 0.15% of TAMOL SN
(based on tall oil solids), the acidic aqueous phase preferentially wets the lignin fraction, and the crude tall oil
separates cleanly by centrifugation. The overall process provides an improved grade of tall oil in substantially high
yields. In addition, TAMOL SN retards the deposition of lignin on the equipment and centrifuges and reduces the
frequency of costly cleanups.
Dispersant Action of TAMOL SN
The dispersant action of TAMOL SN results from its effect of surrounding minute solid particles by a strong anionic
(positive) charge. The particles thereby become mutually repellent and resist recombining to form aggregates.
Furthermore, once the particles are separated, water wets them easily to form free-flowing mixtures. Since TAMOL
SN does not wet and disperse solids by lowering the surface and interfacial tension, frothing and foaming do not
occur when it is the sole dispersant during milling, grinding, and mixing operations. The following table compares
the effect of TAMOL SN and Triton™ X-100, a typical surfactant, on the surface tension of water and the interfacial
tension of a mixture of water and white mineral oil.
TAMOL SN
TRITON X-100
1
percent
5
percent
0.1
percent
Surface tension
in aqueous
solution,
dynes/cma
71
66.5
30
Interfacial
tension of
Arcoprime
90/water,
dynes/cmb
47
36.5
2.4
pH
9.3
9.7
7.5
Properties
aSurface tension of water = 72 dynes/cm
bInterfacial tension of Arcoprime 90/water = 52 dynes/cm
Aluminum, calcium, and zinc salts do not form insoluble precipitates with TAMOL SN. In general, TAMOL SN
retains effectiveness in both acidic and alkaline media and is stable in the presence of mineral acids and bases. It
is, however, often more effective under alkaline conditions. Ammonium hydroxide is suitable for adjusting the pH,
and a small amount may improve the efficiency of TAMOL SN. Certain amino acids, such as aminobenzoic acid,
precipitate the dispersant.
As a rule, 0.5–1.5% TAMOL SN, based on the dry weight of dispersed phase, is adequate for stabilizing dispersions
over a wide range of pH. The optimum level of TAMOL SN depends on the nature of the dispersed solid and the
degree of dispersion, which depends in turn upon processing conditions.
TAMOL SN can be added as a solid or as a 25%–30% aqueous solution to the mixing equipment along with the
other ingredients. Incorporating TAMOL SN into a particular mill charge reduces the grinding time needed to
produce a low fineness factor. In the case of aqueous slurries of zinc oxide, 2.0% TAMOL SN (based on weight of
zinc oxide) can transform a 50% paste into a free-flowing dispersion. Levels of TAMOL SN as low as 0.5% can in
some instances yield good dispersion of clays, precipitated chalk, and titanium dioxide.
Pigment and Dye Dispersions
The dispersant activity of TAMOL SN in colloidal systems, makes it useful in grinding pigments and dyes. The
finished product has a pronounced creaminess superior to grinds made with alkali, and the grinding time is
shorter. TAMOL SN is also active in organic systems sensitive to alkali and permits processing larger batches of
colorant in grinding equipment by increasing the fluidity of the colloidal system. The frothing encountered with
sodium silicate, for example, does not occur with TAMOL SN, which does not function as a surfactant in the usual
sense. There is no carryover of solid when mills are rotated for different materials. Simple rinsing with water
usually suffices to remove traces clinging to the walls. Still another benefit of TAMOL SN results from its light color
and resistance to color change on exposure to light. Consequently, it does not alter the shade of colorants.
TAMOL SN is a particularly good dispersant for carbon black. When equal volumes of acetylene black and 5%
aqueous TAMOL SN are combined (the weight of black is about 10% of the total weight), the carbon is wetted
instantly, and the mass becomes moist within 30 seconds. By contrast, water alone does not wet acetylene black
even after two hours of contact. A concentration of TAMOL SN as low as 1.0% produces a smooth, uniformly
wetted paste that can be diluted infinitely without forming floc or deposits. When TAMOL SN is an ingredient in a
dispersion, mixing and processing equipment is usually easier to clean.
An interesting phenomenon that occurs with TAMOL SN is the reduction of the viscosity of aqueous dispersions.
This effect can be illustrated by treating stiff pastes or moist masses of difficult-to-wet pigments.
The pastes normally require the addition of relatively large water amounts of flow. Adding small amounts of
TAMOL SN solution, however, converts the pastes to free-flowing liquids. Lowering viscosity in this manner
permits the manufacture of dispersions having higher solids content and thereby promotes more efficient
utilization of grinding and milling equipment.
The usual range of TAMOL SN concentrations necessary to produce flow in pastes of various commercial colorants
is 0.5% to 1.5% (based on weight of colorant). More dispersant may be needed in some cases. Table I lists
typical data for several colorants.
Table I – TAMOL SN in Colorant Pastes
Percent Water
in paste
Percent TAMOL SN
required for flow
Cadmium Lithopone Medium Red
16.6
0.66
Ultramarine Blue
32.7
0.08
Mapico Premium Yellow Orange
45.6
0.81
Light Cadmium Red
18.3
0.49
Chrome Orange S
24.8
1.6
Pure Red Oxide
46.8
0.85
Brilliant Deep Maroon
44.5
1.21
Chrome Yellow
29.1
1.63
Pure Indian Red
17.0
1.57
Excelsior Carbon Black
53.0
1.88
Mapico Black
26.8
1.92
Maroon Cadmium
19.7
0.73
Rayox (white-pigment)
31.0
4.92
Colorant
TAMOL SN cannot be evaluated as a dispersing agent by the conventional surface-tension techniques and
methods. A quantitative measurement of the fluidity of a pigment system can be made in a Stormer Viscometer.
In this method, fluidity is defined arbitrarily by the equation:
Fluidity =
revolutions of the spindle per second
weight in grams applied to spindle drive
x 1000
Values of fluidity below 10 indicate a puttylike consistency and high viscosity. Values over 250 show high flow and
extremely low viscosity.
Several pigment dispersions were examined using the Stormer Viscometer method with an 800-gram load. The
test systems were more fluid than the pigment pastes used in the study represented in Table I. Figure 1 shows
the effect adding TAMOL SN at levels up to 1.0% on the fluidity of the systems.
Clay Dispersions
Many industrial uses for clay involve the viscosity relationship of the clay water system. Clays in general are
complex aluminum silicates that form plastic masses in water. Some clays disperse readily in water to yield stable
suspensions, but others floc when diluted with water. Clays do not respond uniformly to the addition of
electrolytes and nonelectrolytes. Most clays consist of negatively charged particles and are peptized or dispersed
by alkaline compounds such as sodium silicate, sodium hydroxide, and sodium phosphate. A material that
stabilizes a clay dispersion is termed a deflocculating or peptizing agent. Coagulating agents, such as aluminum
chloride, calcium chloride, and acids, are termed flocculants. No clear-cut demarcation between the two classes of
compounds exists, however, because while low concentrations of an acid salt may peptize a dispersion, higher
concentrations may have the reverse effect. Furthermore, clays are seldom pure minerals; rather they are
mixtures of several species. As a consequence, the behavior of a commercial clay in the presence of a salt or
surface-active agent cannot be predicted with any degree of certainty.
Figure 1
Percent TAMOL SN on Weight of Pigment
Figure 2
Percent TAMOL SN on Weight of Clay
In general, TAMOL SN is highly effective in reducing the viscosity of clay slurries. At any given concentration of
solids, the smallest amount of TAMOL dispersant that produces a noticeable effect is about 0.025%. Maximum
activity is usually reached at a level of 0.05%; more changes may result at levels to 1.0% TAMOL SN. Figure 2
demonstrates the effectiveness of TAMOL SN in raising fluidity.
One application in which the ability of TAMOL SN to disperse and stabilize clays can be useful is the manufacture
of high-grade white paper stock with clay as a filler.
Potentiation of Nonionic and Low-Foam Surfactants
TAMOL SN exhibits hydrotropic (solubilizing) action for nonionic surfactants in built detergents. It also improves
the antiredeposition effect of built detergents and aids in soil removal and rinseability in hard-surface cleaners.
TAMOL SN is especially useful in formulations designed for such applications as cleaners for transport vehicles,
machine dishwashing detergents, all-purpose concentrate cleaners, and liquid detergents.
TAMOL SN can be used to extend the activity of nonionic and low-foam surfactants. Partial replacement of
nonionic surfactants by TAMOL SN may afford cost savings. A general formulating guideline is that 20% to 50% of
a conventional nonionic or 40% to 70% of a low-foam surfactant may be replaced by the dispersant. The limiting
factor should be the critical micelle concentration of the surfactant at the use dilution. Consequently, the use level
should not fall below 100 ppm for Triton X-100, 60 ppm for Triton CF-10 and Triton DF-12, and 30 ppm for Triton
CF-76.
FDA Status
In our opinion, TAMOL SN conforms to the following Food and Drug Administration (FDA) regulations
covering materials for various food packaging applications.
Regulation 21 CFR
Title
175.105
Adhesives
Limitation
175.300
Resinous and Polymeric Coatings
Up to 0.6% of total solids in can end
cements for 5-gallon or larger containers
176.170
Components of Paper, Paperboard in
Contact with Aqueous and Fatty Food
As an adjuvant to control pulp absorption
and pitch content before making sheet
176.180
Components of Paper, Paperboard in
Contact with Dry Food
176.210
Defoaming Agents in Manufacture of
Paper, Paperboard
177.1200
Cellophane
Up to 0.1% as an emulsifier
177.1210
Closures with Sealing Gaskets for Food
Containers
Up to 0.2% of closure solids
177.2600
Rubber Articles Intended for Repeated
Use
TAMOL is a trademark of Rohm and Haas Company or of its subsidiaries or affiliates, and is intended to designate goods marketed primarily in
North and South America; the same goods may be marketed in other countries, generally under other Company trademark designations.
TRITON is a trademark of Dow Chemical.
These suggestions and data are based on information we believe to be reliable. They are offered in good faith, but without guarantee, as
conditions and methods of use of our products are beyond our control. We recommend that the prospective user determine the suitability of
our materials and suggestions before adopting them on a commercial scale.
Suggestions for uses of our products or the inclusion of descriptive material from patents and the citation of specific patents in this publication
should not be understood as recommending the use of our products in violation of any patent or as permission or license to use any patents of
the Rohm and Haas Company.
©Rohm and Haas, 2008
All rights reserved.
May 2001
FC-162b