IMPROVEMENTS IN THE MANUFACTURE OF VARNISHES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 27th January 1883. Commu-
nicated to him from abroad by La Compagnie générale de chromolithie
represented by Ernest Amédée Boissaye of Paris, France, Director of the said
Company
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
"IMPROVEMENTS IN THE MANUFACTURE OF VARNISHES." [Communicated to him
from abroad by La Compagnie générale de chromolithie represented by Ernest
Amédée Boissaye of Paris, France, Director of the said Company]
This Invention consists in new compositions for varnishes whose base or principal
ingredient is entirely distinct from the resinous substances which constitute ordinary
varnishes.
The base or primary ingredient is composed of
Paper treated with
Nitro-sulphuric acid-
Camphor dissolved in alcohol at 96°
102
parts (by weight.)
32 to 36 ( „
"
These are worked together in a mixer heated to from 50° to 60° Centigrade until
brought to the desired consistence.
The varnish is composed of
The primary ingredient above mentioned
Pure acetic ether
Sulphuric ether at 65°
Castor oil -
-
Venetian turpentine
Methylated alcohol at 96°
Acetate of amyle
Pure crystallizable acetic acid
-
1 kilo
-
2 kilos
250 grammes.
50 to 100 grammes.
150 to 250 grammes.
7'/, litres.
10 grammes.
200 grammes.
The method of preparation is as follows:-The acetic ether and the acetic acid
are mixed together and after letting the mixture stand the kilogramme of the
primary ingredient or base is added and the flask agitated for a period of 6 hours,
[Price 1

page_text: allowing a quarter of an hours interval of repose at the end of each hour. If the
primary ingredient has been ground before being dissolved, the operation will be
easily completed the same day. The sulphuric ether is to be added at the expiration
of 6 hours.
2
When this first solution is effected; (1) add the castor oil to a portion of the
7 litres of alcohol and stir with an agitator until the oil is dissolved and then
pour this mixture into the large flask containing the first solution and agitate until
an intimate mixture is effected. (2) Proceed in the same way with the venetian
turpentine, and (3) Add the acetate of anyle to the remainder of the alcohol and
then add to the mass; mix and agitate the flask until perfect homogeneity of the
liquid is obtained.
The varnish has the following properties:-It is unaffected by water and
humidity, and will also resist weak or concentrated acids and likewise alkalies in
general unless the contact be very prolonged. It takes a very fine polish and is
not liable to alteration when employed for interior work. It is neither soiled nor
deteriorated by vegetable, animal, and mineral oils, nor by paint. By applying it
upon glass coated with ox-gall, transparent and coherent films of varnish may be
obtained. In the same way, a number of articles of solid varnish may be produced
such as goblets, cruets, funnels, plates &c. Fabrics, wood, metals, paper, cardboard,
and all objects coated with this varnish are rendered proof against water, moisture,
acids &c, as above mentioned.
This varnish can only be applied to surfaces warmed either by the sun, before the
fire, or in an oven at a temperature of 35° to 40° Centigrade. If applied to a cold
surface it becomes white and the coating is wanting in coherence and possesses none
of the qualities of the same varnish applied to a warmed surface. Any kind of
brush may be used for applying it. It dries in two minutes at the outside, so that
25 or 30 successive coats may be applied per hour.
The varnish may be rendered more flexible by making it less siccative so as to
adapt it to the requirements of the various uses to which it may be put, and enable
it to be applied to a cold surface, by adding to each litre of the varnish prepared as
above described:
Crystallizable acetic acid
Acetate of amyle
400 grammes.
300 - 3-
and agitating so as to intimately mix the whole together. The substances so added
are already contained in small proportions in the varnish as first described, but the
properties of the varnish are so modified that it may be applied to cold surfaces and
it therefore forms a second composition so to speak, derived from the first one.