Improvements in Transfer Surfaces for Producing Copies of Type Writing or other Printed or Written Impressions, and in the Process of Manufacturing the same.
Year: 1886

page_text: Date of Application, 24th Aug., 1886.
Specification Accepted, 10th May, 1887.
Improvements in Transfer Surfaces for Producing Copies of Type
Writing or other Printed or Written Impressions, and in the
Process of Manufacturing the same.
We, JOHN THOMAS UNDERWOOD and FREDERICK WILLS UNDERWOOD, both
of Brooklyn, in the County of Kings, and State of New York, one of the United
States of America, Manufacturers, 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 :-
Our invention relates to Improvements in Transfor Surfaces for Producing Copies
of Type Writing or other Printed or Written Impressions and the Process of
Manufacturing the same.
The object of our invention is to produce a new article of manufacture adapted
to take the place of the articles of trade, commonly known and designated as Carbon
Paper and Semi-Carbon Paper, which are employed by Type-Writers and others
to produce copies or impressions, either obtained by a machine or by a stylus,
or other writing means.
In carrying out our invention we employ in the manufacture of our improved
transfer surface, Dye Wood solutions or their active principles, which we filter
and precipitato with Alkalies, and Mineral Salts, or with Alkalies, Acids and
Mineral Salts, or with acids or alkalies alone.
After the solution has been filtered the precipitate is removed from the filtering
device and dried.
The precipitate is then mixed with lard-oil, and wax, or their equivalents and
the mixture is then ground together in a warm state.
The dye solutions we prefer to employ are obtained from Log Wood, or
Haematoxylin, the active principle of Log Wood, Brazil Wood, Peach Wood,
Madder or its active principle Alizarino.
The proportions we find to answer well in producing our improved surface are
as follows:
Take 1 lb. of extract of Log Wood, and dissolve the same in one gallon of water,
then add to the solution 1 lb. of soda and 1 lb. of Mineral Salt, using one of the salts
of iron or copper, preferably Sulphate of Copper.

page_text: The mixture thus obtained is then placed in a filter.
After the solution has been filtered the precipitate is removed from the device
employed, and dried.
To overy 2 lbs. of precipitate thus obtained, we add 1 lb. of oil, and 1lb. of
wax and then grind the mixture in a warm state, in what is commonly known
as a paint mill, or other suitable grinding mill.
The heated mixture thus obtained is then applied to tissue paper or other suitable
paper, or fabric, by means of a sponge or other suitable trasferring device.
The paper or fabric to which our improved surface is to be applied, is placed upon
a heated table, by preference formed of iron and heated by steam, but this may
bo varied.
In place of employing oil, wax, or both combined, we can employ any other
suitable oleaginous matter or combination of oleaginous matter, having equivalent
or approximately equivalent properties.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same to bo porformed, wo declare that what wo claim is:
--
1st. The process of manufacturing Transfer Surfaces, by the employment of
precipitates of dye matter, dried and mixed with oil, wax or oleaginous matter,
substantially as set forth.
2nd. The composition herein described, for the manufacture of a substitute for
carbon paper, composed of a precipitate of dye matter in combination with oil, wax
or oleaginous matter, substantially as set forth.
3rd. A sheet of material or fabric coated with a composition composed of a precipitate
of dye matter, obtained as described, in combination with oil, wax or oleaginous
matter, substantially as and for the purpose set forth.
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