Process for the Production of Resin-acid Esters, and the Manufacture of Lacquers and Varnishes therefrom.
Year: 1890

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by Dr. EUGEN SCHAAL, of Feuerback-Stuttgart,
Wurtemberg, in the Empire of Germany, Chemist.]
Process for the Production of Resin-acid Esters, and the Manufacture
of Lacquers and Varnishes therefrom.
I, HEINRICH BECK of 22 Bush Lane in the City of London, Merchant do hereby
declare the nature of this invention and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement:-
I. According to the present invention I employ, for the production of resin-acid
esters, in addition to the resin acids mentioned in the Specifications to Patents
Nos. 12807 of 1884 and 9027 of 1886, the acid copal resins or gums and the
American resins known as gum animi, and generally all acid-resins used in the
manufacture of lacquers and varnishes, these being mainly soluble in alkalis.
These resins are preferably first melted by themselves and there are then mixed
with them other resin-acids of the kind mentioned in the Specifications Nos. 12,80784
and 902788; they may however be converted into esters by themselves, either in the
manner described in the above mentioned Specifications or by the process described
under II.
II. A suitable method for the production of esters, more particularly applicable
when alcohols of high boiling point, phenoles, and hydrocarbons are used, consists in
causing the alcohol to flow slowly into the melted and suitably heated resin-acids, or
the resins or mixtures thereof mentioned under I, the aqueous vapors being withdrawn
as they are produced, by the production of a partial vacuum. In this way the forma-
tion of the esters takes place very rapidly and without any overflowing of the mass.
The resin-acids might of course also be made to flow into the alcohol. For the
conversion into esters of the abietin acid-glycerine ester the following process may be
suitably employed.
100 kilg. abietin acid (in the form of colophonium) are heated in a copper distilling
vessel to from 180° to 210° C.; into the molten mass are then poured in a thin stream
and under continuous stirring, from 10 to 11 kilg. glycerine, while at the same time
a vacuum of about 10 centimetres is maintained. After adding the glycerine the
temperature is raised, under the above mentioned vacuum, to about 280° C. and the
mass is then distilled at a pressure reduced as low as possible for the purpose of
separating the product into softer and harder portions, the temperature being if
necessary raised to about 320° C.
III. This final distillation and purification of the crude resin-acid esters is con-
siderably assisted by effecting it in a current of indifferent or neutral vapours or
gases, by allowing volatile substances such as benzine, oil of turpentine, resin oil, or
gases such as carbonic acid, and nitrogen, to pass, by degrees, and preferably in a
heated condition, into the distilling apparatus.
IV. In order to render resin-acid esters suitable for the preparation of rapidly
drying lacquers, the lead and manganese combinations employed in the manufacture
of lacquers, such as red-lead and pyrolusite, may be mixed directly with the melted
ester at the end of the distilling process (to the extent of from 1 to 2 per cent. of
each) instead of merely mixing these dryers with the linseed oil varnish, as is
customary with the manufacture of lacquers. The mixture thus produced is then
allowed to cool in thin layers, and it can then be used in this form for the manu-
facture of lacquers.
For example, a lacquer may be produced of this material as follows: resin acid
ester 12 parts by weight, turpentine oil 12 parts, linseed oil varnish 8 parts, the ester
being dissolved in the other ingredients at a temperature of about 120° C.

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In the manufacture of resin-acids esters, the substitution either wholly or
partially, for the resin-acids mentioned in the Specifications to Patents 12,80784
and 902786 of acid copal, animi, and similar acid gums or resins employed in the
manufacture of lacquers, substantially as herein described.
2. In the manufacture of resin-acid esters from alcohols of 'high boiling point,
phenoles, and hydrocarbons, the employment of a partial vacuum in place of the
heating, with or without pressure as described in the Specifications 1280784 902786
substantially as described.
3. The method of purifying and distilling the crude resin-acid esters for the purpose
of separating the same into harder and softer portions under atmospheric or reduced
pressure, and with the use of a current of indifferent gases or vapours, in place of the
distillation under vacuo described in the Specifications 1280784 90278.
4. The manufacture of resin-acid esters suitable for the production of rapidly
drying lacquers and varnishes by mixing with the resin-acid esters prepared in the
various above mentioned ways at the end of the distilling process, with the lead
and manganese compounds usually employed in the manufacture of lacquers, sub-
stantially as described..
5. The preparation of lacquers and varnishes by combining the resin-acid esters
referred to in the preceding claims with volatile or fatty oils, hydrocarbons, ether,
ether-alcohol, and the like in the same manner as is done with the natural resins.
Dated this 12th day of February 1890.
ABEL & IMRAY,
Agents for the Applicant.