Protection against Erasure or other Alteration.
Year: 1887

page_text: Protection against Erasure or other Alteration.
I, JOHN JAMESON, of Akenside Hill, Newcastle-on-Tyne, Consulting Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention consists in a method whereby a very sensitive protected paper may
be made in a very cheap way and whereby the degree of sensitiveness may be varied
within wide limits.-I prefer to employ a very fine spray of dense solution of a
highly soluble color such as aniline either by itself or mixed with gum or gelatine or
with a mixture of both, or with any other suitable like medium.1 expose in a dry
or nearly dry state the paper to be protected to this spray whereby a deposit of
separate extremely minute detached spots of color are deposited on and attached to
the paper. Such paper if sprayed with a dense solution of analine alone is extremely
sensitive, and if sprayed with solution of aniline and gum, or gum and gelatine, or
gelatine alone is less sensitive; it may be used as a protection alone or combined with
other protections such as differential glaze or film printing or others, and it may also
be applied to parts of the paper only, by the interposition of stencil plates or
apply this protection by damping such material as fine net with the soluble color and
pressing it by rolls or otherwise against the dry or nearly dry paper.
may
It is of course possible to apply the medium first and to expose the paper before
the spray fully dries to dust of the color used, but I prefer to make the solution
which I have described which I find does not run in the paper.-If the paper be
slightly damped the adherence of the particles of solution to the fibre of the paper is
increased, but too much damping of the paper causes the color to run.
T L
1:1
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page_text: Protection against Erasure or other Alteration.
I, JOHN JAMESON, of Akenside Hill, Newcastle on Tyne, Consulting Engineer 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:-
il
My invention consists in a method whereby protected paper may be made in a
very cheap way and whereby the degree of sensitiveness may be varied within wide
limits. I prefer to employ a very fine spray of dense solution of a highly soluble color,
such as aniline either by itself, or mixed with gum or gelatine or with a mixture of
both, or with any other suitable like medium-I expose in a dry or nearly dry state
the paper to be protected to this spray whereby deposit of separate extremely
minute detached spots of color are deposited on and attached to the paper.-Such
paper if sprayed with a dense solution of aniline alone is extremely sensitive, and if
sprayed with solution of aniline and gum, or gum and gelatine, or gelatine alone is
less sensitive, it may be used as a protection alone or combined with other protections
such as differential glaze or film printing or others, and it may also be applied to
parts of the paper only by the interposition of stencil plates, or I may apply this
protection by damping such material as fine net with the soluble color and pressing it
by rolls or otherwise against the dry or nearly dry paper.-It is of course possible to
apply the medium first and to expose the paper before the spray fully dries, to dust
of the color used, but I prefer to make the solution which I have described which
I find does not run on the paper and altho' it may be applied in other ways (such as
by ruling or any analogous process) I prefer to apply it as described. If the paper
be slightly damped, the adherence of the particles of solution to the fibre of the paper
is increased, but too much damping of the paper causes the color to run.
Having thus described the nature of my invention, I will proceed to describe more
particularly the manner in which the same is to be performed.
The spray being formed in any convenient way, as for instance, by causing an
exceedingly fine jet or series of jets of the solution to be sprayed to impinge with
great force against a shield or shields, or by causing a current of air under pressure to
diffuse the particles of fluid supplied by any convenient means to it or by the revo-
lution at high velocity of circular brushes or discs to which the fluid is supplied,
I usually employ a device to extract from the spray any drops such as I consider
unsuitable in size for the purpose to which the spray is to be applied. For this
purpose prefer to employ a series of plates of wood metal, glass, or other material
placed in a vertical or nearly vertical position parallel to each other and a small
distance apart and by a current of air pass the spray over the top of these plates so
that the larger particles, having the most momentum shall fall on to one or other of
the plates and the smaller particles having less momentum shall fall between the
plates on to the paper which is passing beneath the plates.

page_text: The course
In the drawing hereto attached the plates referred to are marked A.
of the larger drops owing to the combined action of momentum and gravity, would be
(excepting for currents of air) parabolic, and if the plates are deep enough or inclined
enough and near enough together, every drop possessing momentum adequate to
carry it forwards the distance of one plate in the time required for its fall between
the plates would be arrested by contact with the plate while a proportion of the drops
having less momentum would fall clear of the plates. B. B. are the channels in which
the plates rest.-C. is the box intended to shelter the spray from disturbing currents
of air. D. is the scrubber or filter arrangement intended to extract the finer particles of
spray which might otherwise escape. . is the spray nozzle.
If an extremely fine spray be required, I incline the plates so that the angle formed
by the plates in relation to the line of the spray becomes slightly more acute in the
direction from which the spray comes. Each of these plates lies in a small channel
so that particles falling on the plates and trickling down may be carried away by the
channels instead of falling on the paper.
In order to avoid disturbing currents of air and loss of material I prefer to box in
the space in which the spray is dealt with and to filter the escaping air which has
been used to produce or to direct the spray through layers of wire gauze as a sort of
scrubber, so as to extract as much as possible of what might otherwise be lost.
The particles of spray may be otherwise assorted in a current of air by deflecting
plates, so arranged as that the larger particles with proportionately increased impetus
shall be arrested on the plate while the smaller particles floating more freely in the
current of air escape contact with the plates and can thus be used on the paper.
The mixture of material which I prefer to use for spray varies with the nature
of the protection desired if water alone be used to form a dense solution of aniline
alone, the aniline is usually attached to the paper more or less in the form of
exceedingly minute friable crystals which may by friction be very easily broken up
and spread over the paper so as to disfigure it. Such paper is in a very high degree
sensitive and may be too sensitive for many purposes. If gum or gelatine or any
similar material be used with the solution of aniline, the crystals are more or less
locked up in a protecting cover and moderate friction produces no disfigurement.
The sensitiveness of the protection against washing is then in proportion, more or
less, to the solubility of the protecting cover and the thinness of the covering. A
solution of aniline with gum arabic only is very sensitive to water & being affected
by a damp hand may be too sensitive for many purposes.
A very convenient solution producing a much less sensitive paper is made by
mixing solution of aniline in water with a water varnish composed of shell-lac
dissolved in solution of borax. This last mixture, according to the proportion of
water-varnish used may be made of almost any desired degree of sensitiveness and
so that casual contact with a damp hand shall not disfigure the paper but such appli-
cation of moisture to the paper as would be required to extract a washable ink shall
produce adequate disfigurement. It is impossible to prescribe a mixture suitable to
varying circumstances but one which I frequently use for commercial books is
composed as follows: 10 oz. of shell-lac, 2 oz. borax, 40 oz. of water digested in a
water-bath until fluid & then strained; to this solution I add solution of 5 oz.
crystalised aniline blue, 1 oz. aniline black, 1 oz. borax in 120 oz. water so as to form
one gallon. To make the spray more sensitive, I use less of the shell-lac solution, to
make it less sensitive I use more. I find this solution convenient, but manifestly the
variety of solutions which may be used is almost infinite. Spirit varnish with aniline
colors soluble in spirit may be employed in certain cases and the same sheet of paper
in its process of spraying may be made to pass under different spray apparatus so as
to receive a first spray & then a second and so on and thus produce such special effect
as may be desired. I may also employ bleached aniline solution and a re-agent in a
second spray so as to restore the colors on being mixed, or I may spray in two or
more sprays in colorless or more or less colorless chemicals, such as ferrocyanide of
potassium & persulphate of iron, which being mixed, as they would be by any
attempts to wash the paper, produce a dense color, or I may employ one or more

page_text: chemicals in the paper to be protected such as are used in the manufacture of what
are called indelible papers and chemicals such as bin-oxalate of potash in the form of
spray or otherwise in any suitable solution, so that while each separate minute spot
only produces a discoloration exactly where it falls and so a mere tint on the paper,
the application of water which would dissolve the sprayed chemical would produce a
conspicuous stain.
My protection may be employed alone or in combination with any other suitable
protections such as differential glaze described in my patent 1108784.
I am aware that printing inks containing dense soluble colors printing varnishes
to which soluble coloring matter is applied in the form of dust have been used by
printing processes as protection to paper and I do not claim per se the application
of coloring matter for such purposes-but such processes of protecting paper are
expensive and are for that and other reasons, I think unsuitable for many purposes to
which my invention may be applied and they are inapplicable or difficult of application
with such solutions as I employ.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
The use of solution or solutions of dense coloring matter or solutions capable of
producing by mutual reaction dense color substantially as and for the purpose herein
described.
JAMESON & SCHAEFFER,
Agents for Applicant.