India Rubber and Gutta Percha and Electrical Trades Journal. Vol. 14, No. 3. (Aug 20, 1897)

              India=Rubber and Gutta-Percha and Electrical Trades Journal
Vol. XIV., No. 3. August 20, 1897. PRICE SIXPENCE.
New Series.
PRACTICAL REVIEW OF SOLVENTS AS USED
IN THE INDIA-RUBBER AND GUTTA-PERCHA
INDUSTRIES.
EFFECTUAL UTILISATION AND PEEPAKATION OF THE
VARIOUS BOLVENTS. THEIR VARIED NATIRE, AND
PATENTS INTRODUCED.
BY A. CAMILLE.
(^Continued from page 2.)
SOLVENTS IN RELATION TO RUBBER COLOURING AGENTS
{Concluded.)
REASONS FOR USING COLOURS IN SPIRITUOUS SOLUTIONS.
Knowing the unsuitability of water in connection with
almost any form of rubber mass we will only attempt to
deal with other uses in the small space yet available for
concluding this subject. As regards the use of anilines in
the solid state we must recollect that their enormously
concentrated forms of manufacture, and that in the case of
most products, a solution of one half c^nX.. is powerful
enough to cover almost any mass dealt with, and another
important reason is that when in their solid form and
dry state these colouring matters seldom exhibit their
true colour-tone. In examining, for instance, magentas,
rubins, etc., in their undissolved form, we see, instead of
a deep or light red, the surface upon the crystals with a
golden green reflex, and this metallic reflex is even repro­duced
upon other substance treated with their solutions
when applied in highly concentrated form. We thus see
that even if the covering power of these colouring matters
in their dry state were satisfactory, they could not for
other reasons be incorporated in their dry condition like
the ordinary pigment used.
Yet by reason of the unlimited assortment of colour,
shades, and hues of a highly brilliant and fiery nature
the possibility of blending by intermixing, low cost,
and also on account of their highly antiseptic qualities,
these forms of colouring matter, as used hy studied pro­cesses
of application, must one day become invaluable in
the rubber industries, both in the case of incorporation
and the different processes of superficial embellishment.
By reason of the translucid nature of pure rubber the
results would naturally be less fiery than is possible'in the
case of textiles and other non-transparent substanc es : but
all these modified conditions are certain to be overcome
by future improvements with regard to the colouring
agents themselves, and their mode of application.
These same possibilities have been repeatedly demon­strated
in the case of forming layers or films of rubber
without the addition of compounding ingredients or
colouring agents of any kind, as, for instance, may be the
case in certain operations of waterproofing. The use of
solvents, with greater or lesser specific gravity, will bring
about, more or less opaqueness of the layers, and this
can be clearly seen by the different effects of certain
light naphtha kinds, as compared with heavy forms of
benzoline, etc. Again, such differences may be brought
about by the different processes of producing the state
of solution of the gums, and a decided difference must
be experienced where cohobation, or the different forms
of mastication, etc., are effected by varied operations and
modified forms of appliances.
APPARATUS APPERTAINING TO THE DISSOLUTION OF
ELASTIC GUMS.—USEFUL PATENTS INTRODUCED.
Conformably to the title of the treatise, and injustice
to the trade, the different apparatus of utility in the
processes in question, and such modern features as tend
to improve these processes, deserve to be dealt with.
From the full description of the various solvents in this
treatise we shall know the chief requisite attributes of the
machinery, etc., in question, and the principles they
embrace must be fully.£amii|iUiaM^h perfect safety as