91-94-1 Usage
Chemical Properties
colourless to white crystalline solid
Physical properties
Colorless to grayish-purple needles or crystals with a mild or pungent odor
Uses
Different sources of media describe the Uses of 91-94-1 differently. You can refer to the following data:
1. Intermediate in the manufacture of azo dyes and pigments for printing inks, textiles, paints,
plastics, and crayons; curing agent for isocyanate-terminated polymers and resins; rubber
compounding ingredient; analytical determination of gold; formerly used as chemical intermediate
for direct red 61 dye.
2. Used in the production of yellow and
red pigments for the printing ink, textile, paper,
paint, rubber, plastic, and related industries
General Description
Gray to purple crystalline powder. Insoluble in water. Very toxic. Used in the dye industry, curing agent for isocyanate terminated resins.
Air & Water Reactions
Insoluble in water.
Health Hazard
3,3'-Dichlorobenzidine (DCB)
is carcinogenic in several animal species.
Fire Hazard
Combustible.
Safety Profile
Confirmed carcinogen
with experimental carcinogenic and
tumorigenic data. Human mutation data
reported. When heated to decomposition it
emits very toxic fumes of Cl and NOx.
Carcinogenicity
Studies in several test systems have shown
DCB to be genotoxic in vitro and in vivo and
suggest that this effect most likely mediates the
carcinogenicity of the chemical. In vitro, DCB
has induced sister chromatid exchanges,
unscheduled DNA synthesis, and positive
responses in bacterial Salmonella assays; in vivo
DCB induced micronuclei in polychromatic
erythrocytes in male mice and fetuses.
Because of demonstrated potent carcinogenicity
in multiple animal species, evidence of
genotoxicity, and structural relationship to the
known bladder carcinogen benzidine, DCB
should be regarded as a probable human carcinogen
and exposure by any route should be
avoided.
3,3¢-Dichlorobenzidene has no threshold
limit value (TLV) exposure limit and is classified
as an A3, confirmed animal carcinogen
with unknown relevance to humans, and a
notation for skin absorption.
Source
Synthesized from o-chloronitrobenzene in the presence of NaOH and zinc dust (Shriner et
al., 1978).
Environmental fate
Biological. In activated sludge, 2.7% mineralized to carbon dioxide after 5 d (Freitag et al.,
1985). Sikka et al. (1978) reported 3,3′-dichlorobenzidine is resistant to degradation by indigenous
aquatic microbial communities in a 4-wk period. Under aerobic and anaerobic conditions,
3,3′-dichlorobenzidine is mineralized very slowly (Boyd et al., 1984; Chung and Boyd, 1987).
Nyman et al. (1997a) studied the transformation of 3,3′-dichlorobenzidine under laboratory
controlled conditions at 20 °C. Wet sediment (50 g) and water (150 mL) from Lake Macatawa,
Holland, MI were placed in glass serum bottles and purged with nitrogen to ensure anaerobic
conditions to which 3,3′-dichlorobenzidine was added. The bottles were incubated in the dark at
20 °C for 12 months. Soil and water samples were retrieved periodically for transformation
product identification using HPLC. The investigators identified 3-chlorobenzidine as a transient
metabolite from the biological transformation of 3,3′-dichlorobenzidine. 3-Chlorobenzidine
rapidly dechlorinated forming the end product benzidine.
Photolytic. An aqueous solution subjected to UV radiation caused a rapid degradation (half-life
<10 min) to monochlorobenzidine, benzidine, and several unidentified, brightly-colored, waterinsoluble
chromophores (Banerjee et al., 1978). In a similar experiment, 3,3′-dichlorobenzidine in
an aqueous solution was subjected to radiation at λ=310 nm for approximately 15 min. During the
period of irradiation, concentrations of 3,3′-dichlorobenzidine decreased rapidly. 3-Chlorobenzidine
formed as a transient intermediate which underwent dechlorination forming a benzidine,
a stable photoproduct. Depending upon the wavelength used, the benzidine yields ranged from 8
to 12% of the total 3-chlorobenzidine transformed (Nyman et al., 1997). A carbon dioxide yield of
41.2% was achieved when 3,3′-dichlorobenzidine adsorbed on silica gel was irradiated with light
(λ >290 nm) for 17 h (Freitag et al., 1985).
Chemical/Physical. 3,3′-Dichlorobenzidine will not hydrolyze to any reasonable extent (Kollig,
1993).
At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacities at
were 300, 190, 120, and 73 mg/g, respectively (Dobbs and Cohen, 1980).
Shipping
UN2811 Toxic solids, organic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical
Name Required
Purification Methods
Crystallise the benzidine from EtOH, pet ether (m 133o) or *benzene. [Beilstein 13 H 234, 13 I 67, 13 II 106, 13 III 477, 13 IV 384.] CARCINOGEN.
Check Digit Verification of cas no
The CAS Registry Mumber 91-94-1 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 9 and 1 respectively; the second part has 2 digits, 9 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 91-94:
(4*9)+(3*1)+(2*9)+(1*4)=61
61 % 10 = 1
So 91-94-1 is a valid CAS Registry Number.
InChI:InChI=1/C12H10Cl2N2/c13-9-5-7(1-3-11(9)15)8-2-4-12(16)10(14)6-8/h1-6H,15-16H2
91-94-1Relevant articles and documents
Banthorpe,O'Sullivan
, p. 615 (1968)
Surface-active compounds based on modified castor oil fatty substances
-
, (2008/06/13)
The demands on the properties of pigments, in particular in the fields of emulsion paints and printing inks, which constantly become more specific have made it necessary to develop selective and environmentally friendly dispersing, emulsifying and coupling auxiliaries. The compounds according to the invention are esterification and/or arylation products prepared from natural or modified castor oil or ricinoleic acids, which products are alkoxylated and, if desired, linked by esterification with dicarboxylic acids to give recurring structural units. If desired, the terminal hydroxyl groups of these modified alkoxylates of castor oil fatty substances have been esterified with fatty acids, aromatic carboxylic acids and/or resin acids and any free hydroxyl groups which may be present have preferably been reacted with dicarboxylic acids and sulfite to give the corresponding monoesters containing anionic radicals. The compounds according to the invention are suitable for a wide range of applications in the field of surface-active agents, for example in the preparation of azo pigments, emulsion paints and printing inks, for improving the coloristic and rheological properties. The compounds according to the invention are particularly compatible with the environment owing to their biodegradability.
Pigment compositions for solvent and water-based ink systems and the methods for producing them
-
, (2008/06/13)
This invention is an azo pigment composition containing a water insoluble metal salt of a water soluble polymer; a method of preparing said composition and ink compositions prepared from said azo pigment compositions.