IMPROVEMENTS IN THE MANUFACTURE OF ROSIN SOAP OR SIZE
Year: 1862

page_text: LETTERS PATENT to Henry Davis Pochin, of Salford, in the County of
Lancaster, Manufacturing Chemist, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF ROSIN SOAP OR SIZE."
Sealed the 13th May 1862, and dated the 4th January 1862.
PROVISIONAL SPECIFICATION left by the said Henry Davis Pochin at
the Office of the Commissioners of Patents, with his Petition, on
the 4th January 1862.
I, HENRY DAVIS POCHIN, of Salford, in the County of Lancaster, Manu-
facturing Chemist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF ROSIN SOAP OR SIZE," to be as
follows:-
The improvement introduced into the manufacture of rosin soap or size by
this Invention consists in producing the said article in a more concentrated
and portable form than has hitherto been done.
The mode in which the said improved soap or size is manufactured is as
follows-Finely powdered rosin and finely powdered alkali, or carbonated
alkali, in the proportions herein-after mentioned, are thoroughly mixed. This
mixture is fused and kept in a state of fusion until the rosin has combined
with the alkali and the soap is formed. The alkali must be at least in such

page_text: proportion to the rosin as that the mixture when fused shall be soluble in
water. Soap thus formed may be reduced to powder and used for the various
purposes for which rosin size is applicable.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Davis Pochin in the Great Seal Patent Office on
the 3rd July 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DAVIS POCHIN, of Salford, in the County of Lancaster, Manufacturing
Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of January, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Henry Davis Pochin, Her special licence that I, the said
Henry Davis Pochin, my executors, administrators, and assigns, or such
others as I, the said Henry. Davis Pochin, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ROSIN SOAP OR SIZE,"
upon the condition (amongst others) that I, the said Henry Davis Pochin,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Davis Pochin, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement:-
My improvements consist in producing a rosin soap in a more concentrated,
economical, and portable form than has hitherto been done, and in producing
by means of such soap a size of greater efficiency in the manufacture of paper
than any hitherto in use.

page_text: A compound of rosin and alkali has been and is now largely used in con-
junction with some aluminous salt for sizing paper; but to produce a good
size it is essential that the rosin in combination with alkali should bear a
specific relation to the alumina in the aluminous salt; and to produce an
economical size it is necessary that the alkali combined with rosin should be
so proportioned to the acid in the aluminous salt that the whole of the rosin
and alumina employed are precipitated in the sizing engine and retained in
the pulp. In the ordinary process employed for sizing paper these conditions
are not fulfilled, but they may be secured with certainty and regularity by
using my anhydrous rosin soap.
My anhydous rosin soap is thus prepared :-I take the ordinary-rosin of
commerce, having freed it as far as possible from all foreign matter by careful
straining, and grind it to a fine powder, and afterwards mix it intimately with
soda ash or pearlash in quantities varying with the chemical constitution of
the aluminous salt with which it is intended to be used, as well as with the
quality and character of the paper to be sized, but in every case with a
quantity of alkali sufficient when combined to form a soap soluble in cold
water. I next place this mixture of rosin and alkali in a pan and heat it,
either with steam or fire heat, until complete combination has been effected.
When cold I break it up into small pieces, or grind it to a powder, or I find
that when the mixture of rosin and alkali, as above described, is allowed to
remain at rest in intimate contact, the combination will take place without
the assistance of any artificial heat. If prepared in this way, I prefer to mix
several tons of the material at one time, and allow them to lie in a heap for
four or five days, when combination will have been effected. If this combi-
nation proceed too slowly, it may be started by a gentle heat, such as may be
imparted by means of a steam pipe.
I find the best mode of making my size, which I call "Dalton size," to be
as follows:-I dissolve a certain quantity of my anhydrous soap in water, and
add thereto an aqueous solution of my Patent aluminous cake, ammonia,
alum, or other aluminous salt. The proportions of aluminous matter, with
which I mix the preceding material when making my size, vary with the
character of the paper to be sized.
The following proportions are those, which I find best adapted for the
purpose; 1st, for papers of a common class I make my rosin soap of one
hundred and fifty parts of rosin and seventy-five parts of soda ash, such ash
containing forty-six per cent. of alkali. In making my size for such papers I
use ten parts by weight of such soap with eight parts of the Patent alumi-
nous cake. If ammonia alum be used, ten parts of rosin soap combined with

page_text: eleven parts of such alum will form a size of a similar kind. For papers of a
fine kind, such as writing papers, I make my rosin soap by mixing one
hundred and sixty-five parts of rosin with one hundred and sixty-five parts of
soda ash, the soda ash containing forty-six per cent. of alkali; and for forming
my Dalton size, I mix ten parts of such soap with thirteen parts of aluminous
cake, or eighteen of ammonia alum. If a more acid salt of alum than either
of those above mentioned is used in making this size, the amount of alkali in
the soap must be increased in proportion. If a more neutral salt, such as
cubical alum is used, the alkali in the soap must be reduced in a correspond-
ing ratio, so as to maintain the relative proportions between the acid and
alkali, as given above.
I claim the sole right to make, use, exercise, and vend an anbydrous rosin
soap and Dalton size, produced substantially as above described.
In witness whereof, I, the said Henry Davis Pochin, have hereunto
set my hand and seal, this First day of July One thousand eight
hundred and sixty-two.