Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition,
2002 Electronic ReleaseDISPERSE SYSTEMS AND DISPERSANTS -
Dispersants (Rudolf Heusch, Karl Reizlein)
5.1.2. Formaldehyde Condensation Products
Table (4) summarizes important dispersants produced by
condensation of aromatic compounds with formaldehyde. The following
describes a typical production of a dispersant of this category.
With suitable variations it can be applied to a number of products
formed by condensation with formaldehyde [50-00-0]. [70], [71],
[72], [73], [74], [75], [76], [77], [78], [79]
Naphthalene (200 parts) is reacted with 200 parts of 98%
sulfuric acid for 5 h at 160165 C in an iron tank. After the
solution has been cooled to 80 C, the mixture is diluted with 90
parts of water in a lead-lined stirring vessel. Then 107 parts of a
30% formaldehyde solution are added and the mixture is stirred for
20 h at ca. 80 C. Toward the end of this period, the mixture is
gradually heated to 100 C. Neutralization is carried out at 2025 C
with ca. 165180 parts of a 25% ammonia solution. The neutralization
product is then filtered and, if necessary, dried in a vacuum drum
drier [80].
Numerous variations of this synthesis are possible, and a wide
range of aromatic compounds and their derivatives can react with
aldehydes, ketones, and compounds that eliminate aldehyde groups.
The following three typical examples supplement those listed in
Table (4):1) Dispersants produced by condensation of aromatic
sulfonic acids and benzyl chloride [100-44-7] or
benzoin [119-53-9] [81]2) Dispersants produced by condensation
of various alkylarylsulfonic acids with a halogen arylsulfonic
acid [82]3) Dispersants produced by condensation of sulfonated
phenols, 2-naphthols, etc. with formaldehyde and
various nitrogen compounds [83]Finally, special processes have
been developed for improving the quality of dispersants or for
adapting them to special applications [57]. Thus, the following
specific products can be prepared:
Products with low sulfate content [84]Low-foam, alkali-resistant
sulfomethylation products obtained from mono- and polynuclear
phenols [85]Thermostable condensation products [86]Low-foam
condensation products obtained from diphenyl derivatives
[73]Ethoxylated and sulfated condensation products obtained from
alkylphenols and formaldehyde [87]Thermostable sulfomethylation
products [88]Phenolformaldehyde condensation products containing
sulfonic groups and having improved dispersive action [89]Products
that have no reducing action on sensitive dyesAlmost colorless
sulfomethylation products that are also suitable for optical
brighteners [85], [90]Dispersants that do not stain fibers [87],
[91]Postcondensed products with improved dispersive properties
[92]Phenolformaldehydehydrogen sulfite condensation products that
contain nitrogen and are low in alkali concentration
Commercial polysulfonate products are listed as follows
[69].Condensed sulfonates: Avolan IS (Bayer); CHT dispersants SMS
(CHT); Dispersant EB (PUC-FMC);
Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition,
2002 Electronic Release Wiley-VCH. Weinheim. Germany.Page: 1
Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition,
2002 Electronic ReleaseDISPERSE SYSTEMS AND DISPERSANTS -
Dispersants (Rudolf Heusch, Karl Reizlein)
Dupramin DS (AKZO); Dyapanol (Yorkshire); Irgasol DAM
(Ciba-Geigy); Lyocol O, Lyocol RD, Lyogen PN (Sandoz); Matexil
DA-AC (ICI); Osimol DPA (Grnau); Setamol WS (BASF); Solegal A, P
(Hoechst).Liquids: Tamol NH, NNO, NOP (BASF); Tanede DPA (Tanatex);
Texamol WS (ACNA); Vultamol (BASF); Wotamol WS (VEB Wolfen);
Baykanol PQ, Baykanol LS, Dispersant SS, Dispersant 523 (Bayer);
Melmeny (SKW Trostberg), Lissatan AC (ICI); Demol N (Bayer,
Japan).
These important dispersants find applications in the following
fields [93]:1) Milling additives and dispersants for pigments and
dyes2) Dispersants and plasticizers in the building industry3)
Dispersants for polishing and abrasive powders4) Stabilizing agents
for resin glue emulsions, e.g., Tamol NOP (BASF)5) Auxiliary agents
in the emulsion polymerization of synthetic rubber6) Dispersants
for fillers, pigments, and vulcanizing agents in natural and
synthetic rubber latices7) Boiling-temperature degreasing agents to
which Tamol N brands (BASF) have been added to improve
the stability of the solution and increase its dirt-suspending
power
Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition,
2002 Electronic Release Wiley-VCH. Weinheim. Germany.Page: 2
