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Патент USA US2116768

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Patented May 10, ‘1938.
UNITED srA'r as IPATENT owes
Ben W. Rowland, Appleton, Wis.,-aesignor to‘In
r1, Appleton, Win. a
stituteo! Paper
4_ corporation of
No’Drawing. Application December 7, 1934,
Serial No. ‘756.533 .
s Claims.
((21. 134-450)
My ‘invention relates to the sizing of» paper and
hus to do more particularly with an improvement
' in so-called“‘engine sizing”, wherein rosin and
a setting agent are commonly used.
‘ . The-paper art has for many years been familiar
‘ peanuts, etc., ‘as well as the leguminous ?our it- ‘ -
self ;-I may also use other proteins which vifunc
tion as hydrophilic emulsoid colloids, such as
milk casein, glue, etc. For convenience‘I reier
to the action here described by the electrolytic _ 5 _
with this type of sizing. which is used particularly term of “hydrolysis", although I do not restrict
in theimanui’acture of printing'papers and the /- myself to any theory of operation.
like. As usually practiced, this process consists
in adding to the'pulp in the hollander or beater
The following is a preferred example of my .10‘
a solution of mixed sodium resinate and free rosin
resulting from a partial neutralization of rosin
,by alkali (prepared by boiling rosin with soda
- ash) and, after the beating operation, adding a
substantial quantity of a solution of aluminum
sulphate or paper-maker's alum. According to
the generally accepted theory,‘ the ensuing re
invention, it being'understood that the same is _
merely illustrative and not in any sense limiting.
The heater is furnished with stock in the usual
way except that no alum or white water con‘
taining the same is introduced. After the beat- 15
ing operation-is substantially completed, my im
action results in‘th'e precipitation of free rosin. proved sizing material is added. The quantity of
which, with some alumina, becomes attached to size may, of course, vary within wide limits, de
the ?bers and forms a varnish-like coating on pending l-llwn'the nature of .the pulp and the
.the sheet after it is passed‘ between the hot " quality of ‘the paper intended to be, produceduz-o
Roughly, the amount of dry size in the sizing
It has been supposedwithin recent years that ' solution may usually represent from 1 to 2 per
' the eiiectiveness‘oi sizing or this type depends cent of the dry weight of the stock;
to. improved sizing material justreierred to
to a large extent upon the smallness or the par
ticles of resin deposited upon the ?ber; that is to ' may be prepared as follows: To an aqueous.
say that, generally speaking, the smaller the par solution of sodium resinate of a strength of, say
21/: per cent and preferably containing a slight
-.ticles the more e?ective the sizing. In‘ accord
ance with this theory, it has been proposed that rexces's oi 'free rosin but containing no alum, is
- the“ resin .be dispersed by means of}
30 without the use of. a1kali,>and it has also been
proposed (Wieger United - States Patent No.
1,882,680, October 18, 1932) to prepare the sin
ing solution by heating the resin in the neighbor
qhood of.‘ its melting point in the presence of an
35 alkaline solutionv containing a protective colloid,
such‘ as casein. All or these prior-art proposals
have’ been and are subject to serious objections.
laddedaproteinous. material as'described above.
for example, soy bean casein.
The proportion‘ oi’ ‘
protein added may vary considerably, and I have
found that my process may be practiced satis
iactorily with from .10 to 50 per cent or more‘
or less of dry; protein based on the‘ weight of dry
sodium 'resinate, although I preier to operate
within‘ the range just speci?ed." The mixture is
allowed to ‘stand until the protein has become 1
It will be seen ‘that in these methods an attempt‘" dispersed and the resin soap has been hydroliaed
' is made physically 1to subdivide the resin to ob . partially or wholly, depending upon the condi»
.tions. This will be" indicated by increasing
turbidity of. the liquid. The reaction may be im
produced a size of colloidal resin by the method proved by moderate stirring and also hastened
of molecular condensation or aggregation, with and extended by heating to temperatures gen
erally ‘not-exceeding approximately ao°‘-c., but in
numerous advantages which will become appar
some cases up to the-boiling point.
tain particles of colloidal size.
.- In accordance vnth my invention there is
Iv have foundv that ‘protein matter suspended
in the presence of alkali resinates, functions si-'
.?ciently as an alkali binder, i. e., to abstract the
' The reaction may
be improved and ex
tended by the‘ addition of _very small quantities '
of dilute acidic materials, and preferably by the 1
emulsion or suspension, from which it can be
addition of butler mixtures,:such as boric acid
mono- and di-basic phosphate
dimension. As examples o! proteins which'I have
the alkalinity of the sodium resinate solution
alkali and thus ireethe resin in
form ofan
deposited on the fiber in particles of colloidal _ -mixtures, such as have the property of lowering
ioundsatisiactory; I mention the "casein" ex- _ without ,overstepping into a zone of acid pre
tracted from ‘soy bean hour as well as that ob- ' ; cipitation. The ?nal pH value should not be
55 tained from other leguminous materials, such as
below about ‘I pH.
2,1 16,76§
As stated above, I prefer to use at least 10 per
occurs under the strongly acid conditions of
cent or more of protein material based on the
ordinary sizing.
weight of sodium resinate, but my invention is
‘ Various other advantages resulting from my
not limited to this minimum. In fact, I have
found that my process will operate with much
‘smaller quantities of protein, say, froml to 5'
invention will be apparent to those skilled i
per cent.
the art.
Numerous variations and modi?cations com
‘ . ing within the spirit of my invention as set forth
In the use of my improved size describedv above, above will no doubt suggest themselves to those
the liquid is introduced into the beater or hol
skilled in the art. Hence, I do not wish to be
10 lander, as stated above, preferably after most of
limited to the speci?c embodiments or details 10
the beating operation has been completed. It] herein given but intend that‘the scope of my in- '
will be desirable at this point to add su?icient vention is to be limited only by the appended
acid-reacting material to render the stock neutral ' claims, which are to be interpreted as broadly as
(pH 7.0) or slightly acid, preferably of a pH ,will be permitted by the state of the art.
between 6.0 to 6.8. Usually this will require the
While I refer speci?cally herein to rosin siz-‘l5
addition of only atrace of acid, and care should ing, obviously my invention may be used with any‘
be taken to avoid too high an acidity. If the practicable resin or like material.
' stock is alkaline, excessive foaming is likely to
I claim as my invention:
occur and also the sizing e?ect is greatly reduced,
1. A- method of preparing -a paper pulp sizing
20 while, if the acidity is too high, the size tends to
solution containing acid 'precipitable colloidal 20
precipitate in large ?ocks, and thus the deposit particles of rosin which comprises adding to a
of colloidal particles as contemplated by my in
dilute aqueous solution of alkali resinate about 10
vention is not obtained. For- producing this to 50 per cent soya bean-‘casein based on the
change in acidity, I prefer, for purposes-of con
weight of the alkali resinate, allowing-the mix
venience and economy, to use paper-maker's ture to stand until the casein has become dis- 25
alum, although I may also use practically any persed and the alkali resinate has become at least
acid, such as. acetic, hydrochloric, etc., or any partially hydrolyzed as indicated by the increas
acid salt, as well as alum, such as aluminum
ing turbidity of the solution.
2. A method of preparing a paper pulp sizing
Sizing in accordance with my invention pre
solution containing acid precipitable colloidal 30
sents many advantages. Thus, I am able to pro
particles-of rosin which comprises adding to a
duce a size effect against water penetration of dilute aqueous solution of sodium resinate' con
from 200 to‘ 300 per cent better than that. ob
taining a slight proportion of free rosin about 10 '~
tained from ordinary rosin size. The process is to 50 per cent soya bean casein based on the
35. easy to carry out inasmuch as no special equip
weightof the sodium resinate, stirring the’mix- 35
ment is required either for the preparation of the ture until the casein has been dispersed and the
size or‘for its application to the stock. Further
sodium resinate has become partially hydrolyzed
more, the composition of the size can be accu
as indicated by the increasing turbidity of the
rately adjusted to‘ meet thev furnish conditions, solution, and ?nally adjusting the solution to a
'40 which is a very great advantage, since various pH value of about '1 by the addition oi’a small .40
pulps require different amounts of free rosin in quantity of weakly acidic buffer material; -'
order to be properly sized.
A further advantage accrues from the fact that
my improved size gives the ‘best results at the
3. A paper pulp sizing solution having a pH
value of about 7 and containing acid precipitable I
colloidal particles of rosin, comprising, the reac- .
neutral or very slightly acidconditions of the . tion product of a dilute aqueous alkali resinate, .45
furnish, thereby insuring a lower acidity in the ‘solution with about 10'to 50 per cent casein
sheet than is customary with the usual rosin siz
protein based, on the weight of the alkali resinate.
ing. This results in greater permanence of the
sheet as well as in less damage to equipment than
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