Improvements relating to the Treatment of Paper for Receiving Printed Impressions.
Year: 1893

page_text: Date of Application, 30th Aug., 1893
Complete Specification Left, 25th May, 1894-Accepted, 30th June, 1894
PROVISIONAL SPECIFICATION.
Improvements relating to the Treatment of Paper for Receiving
Printed Impressions.
We PAUL MORITZ BERGER, ROBERT WALDBAUR, and EMIL FRIEDRICH
WORLITZER of the Firm of Berger and Wirth of Leipzig-Schönefeld in the
Empire of Germany, Manufacturers, do hereby declare the nature of this invention
to be as follows :-
:-
It has been found that natural paper is not very suitable for receiving printed
impressions more especially of illustrations since the paper soaks up the ink
unequally in different places and the lights and halftones of the illustrations
and similar light printing are apt to appear blotchy and of other than their true
value.
Although this inconvenience is overcome by the use of highly glazed paper
the latter is not always desirable and is easily damaged on its surface, moreover it
is difficult to obtain a uniform glazing on both sides of the paper.
The present invention is intended to overcome the objections to the use of the
aforesaid natural paper by a method of treatment designed to fill up the pores of
the paper without change in its general appearance so as to remove the unequal
absorption and render it capable of taking the ink equally all over and on both
sides.
For this purpose we cause a deposit of insoluble metal salts on or in both sides
of the paper by immersing the paper in solutions adapted to develope and precipitate
such salts and afterwards washing the paper to remove soluble salts used in or
resulting from the reactions necessary for such deposit.
The one of these solutions may contain alum, sulphate of alumina, Glauber salts
phosphate of soda and the like or some or any of these and the other solution
may contain chloride of barium, soda chloride of calcium and the like or some
or any of these.
The immersion of the paper in one and then into the other solution will result in
the deposit of insoluble salts of aluminium barium or lime, such as barium sulphate,
aluminium hydrate, sulphate of lime, and phosphate of lime.
Coloring matters may be added if the paper is to be tinted, and the paper can
be sized or re-sized if required.
Dated this 30th day of August 1893.
R. HADDAN,
Agent for Applicants.
COMPLETE SPECIFICATION.
Improvements relating to the Treatment of Paper for Receiving
Printed Impressions.
We, PAUL MORITZ BERGER, ROBERT WALDBAUR and EMIL FRIEDRICH
WORLITZER, of the Firm of Berger and Wirth, of Leipzig-Schönefeld, in the
Empire of Germany, 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 :-
Paper, in its natural state, as hitherto used for illustrated work, is not particularly
suited for block-printing. Its pores absorb the printing ink unevenly, so that,

page_text: especially with light inking, it is difficult to get a good impression. Enamelled
paper is not liable to this objection, but its use is confined within narrow limits both
on account of the delicacy of the enamel coating and owing to the difficulty of
obtaining a paper uniformly enamelled on both sides.
These evils are to be obviated by the use of paper prepared according to the
process described herein.
In this process a coating of insoluble metallic salts is deposited on both sides of
the paper, which coating serves to seal up the pores of the paper, and on
subsequently passing the paper through the glazing rolls it will assume a smooth
surface, which will take the ink in the same way as enamelled paper. The paper
thus prepared, however, is not liable to the aforesaid drawbacks of enamelled paper
and presents the appearance of paper in the natural state. The coating is produced
by running the paper first through a bath composed of alum, sulphate of alumina,
sulphate of soda, phosphate of soda or the like, and then through a solution of
chloride of barium, carbonate of soda, chloride of calcium or the like. In the
course of this process, precipitates of sulphate of baryta, hydrate of alumina,
sulphate of lime, or the like are deposited on or in both surfaces of the paper. If
found desirable, the paper before being dried is washed in water in order to remove
any soluble metallic salts that may have originated or remain in the process of
precipitation. The order of sequence of the above-mentioned solutions may also
be inverted, according to the manner in which the substances in question are found
to act on the paper. The coating of precipitates may also be colored, as desired,
by pigments or colors, and the paper may likewise be re-sized in the course of this
process.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. The process for the production of a chemically prepared paper, particularly
adapted for block or plate printing, and which combines all the advantages of
natural and enamelled paper without possessing any of their objectionable properties
for printing purposes, such process consisting in providing the paper with a coating,
either colored or otherwise, of metallic salts, which coating is produced by the
precipitation of chemical combinations formed immediately on or in the surface of
the paper, essentially as described above.
2. The product prepared by the process essentially as above described in
Claim 1.
DAL 1
1001
R. HADDAN,
Of the Firm of Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, W.C., Agent for Applicants.