Evening star., 1939-05-27
European Chemists
Make Advances in
Paint Industry
British Develop New
Treatment for SheIIoc
Soluble in Water

Although current activities in
Europe would suggest that the
chemists must be primarily engaged
in developing mechanical features
for modern warfare, there is evi-
dence to the contrary. The paint
and varnish industry, to mark one
instance, Is constantly being ex-
panded by new developments not
only on this side of the water, but
also among our European and East
ern neighbors.
To British chemists are attributed
some of the most significant de-
velopments in paints and solvents.
Ranking highly in Importance is the
new treatment of shellac to render
1t soluble in water but moisture
resistant when dry. This develop
ment will doubtless prove most valu-
able since any compound that is
both water soluble and water
! resistant, yet moderately elastic,
would go long way toward solving
the problem of painting damp sur
faces.
under the concentrated attention of
both American and British chemists
and steps have been taken in the di-
rection of blending phenolic and
alkyd resins. Alkyds, though very
elastic, adhesive and resistant to
light, are not satisfactorily water
resistant. The Phenolics. however,
resist both water and alkais, but
incline toward discoloration. Ac-
cordingly, when varnishes are made
from the newer types of phenolic
resin modified by the right amount
of alkyd, excellent white enamels
are produced which remain white.
Sufficient time has not elapsed since
their production to ascertain whether
they are as Weather-reSiStant as
other resins, but phenolic varnish
with alkyd content is bound to be
more adhesive, more elastic and less
brittle, while the phenolic content
creates water and salt resistance.
British pigments also show i'm
portant advancement. Particularly
outstanding is new color called
claimed to be as permanent as the
monastral blue. The production of
new type of titanium pigment
claimed to be less likely to chalk
than the older types is also note
worthy.
Although paints that indicate a
rise in temperature by changing
colors have been in use for some
years, within the last year or two
rapid progress is marked both in
their development and the technique
of their use These paints, used
mainly where a visual warning of
temperature change is necessary
particularly on machine bearings
have been limited in use to cases
of moderate or low temperature,
and have not shown sharp or per-
manent color changes. The new
paints, however, promise to prove of
particular Importance from the
angle of aircraft fuel efficiency and
especially in the design of air-cool-
ing guides. They will also rank
highly in the field of electrical heat
ing equipment and for other ap-
paratus where indication of temper
ature changes and distribution is
necessary. The new colors are
reasonably clear and definite in
changing with distinct fluctuations
in temperature. Some of the colors
used change but once, some change
twice and some have three distinct
changes-for example, light green
to light blue to olive green to gray
brown.
From India comes news of a note
worthy method of preparing
bleached lac, that basic ingredient
of shellac, used in varnishes and for
other finishing preparations. This
method, perfected by the Indian
Science Institute, makes possible the
storing of bleached lac in a dry
state for a considerable length Of
time without detracting from its