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Патент USA US2411824

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2,411,824
PatentedNov. 26, 1946
UNITED" STATES. PATENT orncs
METHOD OF PREPARING a pay size
James -K. Farrell, Wilmington, :DeL, assignor to
Hercules Powder ‘Company, Wilmington, Del” a
corporation of Delaware
N0 Drawing. Application May 14, v1-945,
Serial No. 593,759
.
_
_6 Claims.
(01. 260,-—105;)
i
This invention relates to the production of sa
poni?ed rosin dry size.v More particularly, :the
invention relates to .a method of producing .an
improved saponi?ed rosin ,d'ry size characterized
by its high apparent density in bulk, and :to ‘.the
2
also leads to the formation of excessive quantities
of dust, such dust being both inconvenient and
disagreeable during handling and use of the size.
Compacting and subsequently comminuting the
size and _.separating out the desired particles in.
ifying rosin ‘with an aqueous solution of alkali,
volve additional steps in the production process
that require additional equipment otherwise not
needed. Additional time is required in the proc
generally caustic soda, and drying the product .of
ess, and the cost of the treatment tends to offset
saponi?cation. Onemethod that has been em
ployed involves introducing the rosin and aque
ous solution ofalkaliintoa closedreaction-cham
any savings that otherwise {would be accom
product obtained.
Saponi?ed rosin dry size :is prepared ‘by vsapon
'ber, heating the-saponifying materials to an ,ele
vated temperature and under superatmospheric
pressure, and :then discharging the . saponi?cation
mixture at the elevated:temperatureand pressure .
into a zone in which a drying atmosphere is
maintained at substantially atmospheric pres
sure, thereby substantially completely‘desiccating
The present invention provides [a method
whereby a saponi?ed rosin dry size in ?nely-di
vided form and having an apparent density in
‘bulk of from about '20 to about 35 pounds per
cubic foot may be produced directly by a spray
drying vtype of process without the necessity of
subsequent treatments heretofore employed.
The ‘invention thus serves to overcome the disad
the saponi?cation mixture to provide a dry, 20
yahtageoiisyfeatiires of methods heretofore avail
able !for thelproduction of saponi?ed rosin dry
either in an intermittent fashion or in a continu
product ,free of certain undesirable characteris
rtics'ofsthe low apparentdensity products prev-i
?nely-dividedsaponi?edrosin size. It has been
proposed to carry-out this general type of method
ous manner.
Saponi?ed rosin dry size heretofore produced
by such methods has been undesirably light and
size and also serves to provide an improved size
Kously available.
'
Generally speaking, the present invention ‘in
v'olves a methodof ‘preparing saponi?ed rosin dry
?u?y. Generally speaking, it has had an appar
ent density in bulk in the order of about 4 to
about 12 pounds per cubic foot. Because of the
“sizein ‘the ,form of discrete, free-flowing particles
‘the compacted particles andseparating out the
‘8% moisture and having "an apparent density in
advantages whichrender them not.entirely(satis
factory. Forcing of'the sizeparticles-into bags
vlead to the formation of theimproved product.v
readily soluble in water and having a high appar
large volume occupied by a given weight of such 30 ent. density in bulk, which comprises saponifyinwg
rosin with an aqueous solutionof an alkali metal
size, vits packaging, handling, and the like, have
alkali and then discharging an aqueous mixture
‘been inconvenient and unduly expensive.
comprising the saponifled rosin and containing
The vapparent densityin ,bulk of such dry size
not ,lessthan 22and lupto about 30% by weight
may be increasedduring packaging to about 15
pounds pervcubic foot by forcing,.or ramming, the , .of water, based on the total weight of saponi?ed
rosin and Watenat an,elevatedtemperature and
particles into the bags or othercontainers so as
pressure, into a drying atmosphere maintained
to compact-theparticles into smaller ones which
at substantially atmospheric pressure and at a
occupyjless space and therefore have a higher ap
temperature of from about 240° to about 325° F.,
parent density in bulk. Theapparent density of
thereby obtaining thesaponi?ed rosin dry size in
the ‘dry size also may be increased by compacting
__a ,?nelyrdivided form containing not over about
the jysizep'articles and subsequently comminuting
bulk of “from about “20 toabout 35 pounds ‘per
particleshaving the desired size ‘to obtain a prod
cubic foot. ;The_'.i__nvention.also includes the par
uctghavinga higher apparent density in bulk.
, Such methods of increasing the apparent dens .45 ticular conditions and methods of operation
which,_i_n conjunction with the described steps,
ity__of saponi?ed rosin dry size have-certain dis
The product obtainedin accordance .With the
present invention comprises discrete, readily wa
or. othercontainers does not lead toasgreat .an
increase ,in density as is desirable. Because -.of :50 teresoluble, noncompactedparticles . of areaction
the ‘high ‘pressures that ‘must .be ‘applied ade
quately to reduce the volumeof the siZ__¢,.an ex
cessive number of bags are broken injthaprocess,
lnvolvingadirect lossof money as well as of time
endimaterials- ll‘he ‘shattering of the ‘particles
productof an alkali metal'alkali and rosin, being
substantially desiccated andhevine an apparent
bulk-density-of -f;rom~_about-2_0 to about-35 pounds
per-cubic‘foot. gThe productis substantially non;
dusty,~con-t;aining-lessthan;5%,.of particles capa
25,411,824:
3
4
ble of passing through a No. 200 mesh sieve, but
containing about 25% of particles capable of
passing through a No. 100 mesh sieve. The prod
uct is substantially completely desiccated, con
taining less than about 8% and preferably less
than about 3.5% moisture.
The improved product, because of its high ap
parent density in bulk, may be packaged in small
,
ture to a ?ne dry powder. The dry size thus ob
tained was found to have an apparent density in
bulk of about 26 pounds per cubic foot and to con
tain about 3% moisture by weight.
To illustrate the critical e?ect of the amount
of water contained in the saponi?cation mixture
upon the apparent density of the size product in
bulk, a second lot of dry size was prepared as
er containers than heretofore necessary, thereby
above, but adding only sufficient water to the
providing more ef?cient utilization of containers 10 paste size to provide a saponi?cation mixture con
as well as of storage and shipping space.
The
taining 17.5% water. A dry size product pre
pared from this mixture under otherwise similar
conditions had an apparent density in bulk of
The method of the present invention provides this
only about 11.5 pounds per cubic foot.
improved product directly by a spray-drying proc 15
Example 3
ess and without subsequent treatments. The
process of the invention therefore provides im
To illustrate further certain aspects of the pres
portant advantages from the standpoint of pro
ent invention and the desirable results attained
thereby, three saponi?ed rosinv size compositions
duction and greatly simpli?es the production of
saponi?ed rosin dry size having high apparent 20 were prepared by saponifying a mixture of wood
density in bulk.
‘
'
rosin and gum rosin containing 85% gum rosin
Having set forth the broader aspects of the
and 15% wood rosin, by treatment with concen
trated sodium hydroxide solution in an autoclave
invention, the following examples will serve to
at elevated temperature and under superatmos
illustrate certain speci?c embodiments thereof.
In the examples, all quantities of materials are 25 pheric pressure. The saponi?cation mixtures at
the completion of the saponi?cation reaction were
given in parts by weight unless otherwise speci
?ed.
found to have the contents of water shown in the
table presented below. Each of the aqueous sapon
Eztample 1
nondustiness of the size product renders its han
dling and use more convenient and agreeable.
i?cation mixtures then was discharged at a tem
'Two thousand parts of gum rosin having an 30 perature of about 365° F. and under a pressure
of about 135 pounds per square inch countercur
acid number of 165 was melted and introduced
rent to a circulating drying atmosphere main
into an autoclave of the type customarily used
tained at substantially atmospheric pressure and
for saponi?cation of rosin. A 39% solution of
heated to a temperature of about 260° F. so as
sodium hydroxide in water, containing 240 parts
to substantially completely desiccate the mix
of alkali, was injected into the molten rosin. The
ture. A comparison of the apparent densities of
mixture was heated to a temperature of about
the three products thus obtained is shown in the
360° F. and under a pressure of about 135 to
table presented below. Each of the products con
about 140 pounds per square inch for a period
tained less than 5 % moisture.
of about 10 minutes. Then 284 parts of water
was injected into the saponi?cation mixture while 40
maintaining the temperature at about 360° F.
After completion of the saponi?cation reaction,
the contents of the autoclave contained 26.5%
water, based on the total weight of saponi?ed
rosin plus water.
The mixture then was dis
charged at the stated temperature and pressure
countercurrent to a drying atmosphere circulat
Water content of Apparent density
saponification in bulk of product,
mixture
lbs./cu. it.
Percent
24.5
22. 5
18. 5
23. 3
21. 4
12.3
ing through a blow chamber and heated to a tem
perature of about 260° F. and under substantially
atmospheric pressure. The saponi?cation mix’
ture thereby was dispersed into ?nely-divided
particles and rapidly converted to a substantially
completely desiccated state. The size product
As shown by the examples, the ?rst step in the
present process involves saponifying a rosin with
a concentrated aqueous solution of an alkali
metal alkali to provide an .aqueous saponi?ca
tion product of rosin and alkali. Sodium hydrox~
was collected as a ?nely-divided dry powder. It
ide is the preferred alkali, although other alkali
contained approximately 3.4% moisture. It had 55 metal alkalies may be employed. Thus, a por
an apparent density in bulk of 25.2 pounds per
tion of the caustic alkali may be replaced by
cubic foot and contained 0.13% free alkali.
sodium carbonate, if desired, as by ?rst prepar
ing a soda-cooked paste size using an amount
Example 2
of sodium carbonate up to about 80% of the theo
Gum rosin was partially saponi?ed with an
retical equivalent of the rosin. In such a case,
aqueous solution of sodium carbonate in water
the saponi?cation of the rosin is completed with
to provide a paste size containing about 15.5%
the concentrated caustic alkali in an autoclave,
water and about 26.8% free rosin on a dry basis.
as in Example 2, and the remainder'of the proc
One thousand parts of the paste size was intro
ess is carried out as herein described. Because
duced into an autoclave, and 27.4 parts sodium
ofv the difference in cost between caustic soda and
hydroxide dissolved‘in 202 parts of Water was
sodium carbonate, it often is advantageous to
added. The contents of the‘ autoclave were heat
proceed in this manner. The total amount of
ed to about 365° F. and under a pressure of about
alkali employed is such that a substantially neu
140 pounds per square inch for about 20 minutes.
tral size product is obtained. Thus, there is em
The saponi?cation mixture was found to contain 1 70 ployed an amount of alkali adapted to provide
about 30% water. The mixture then was dis
a size product containing from not more than
charged at the stated temperature and pressure
about 8.0% free rosin to not more than about
into a drying atmosphere maintained at about
0.5% free alkali.
‘
300° F. and at substantially atmospheric pres
‘ As the rosin, there may be employed either
sure, thereby desiccating the saponi?cation mix ‘75 ‘gum or wood rosin in any of the several color
2,411,824
‘grades, or mixtures of the-same. Alternatively,
the acids occurring in such rosins, such as abietic
formation of the ?nal product. The improved
results of this invention are closely related to the
temperature and humidity conditions of the at
mosphere. The atmosphere is maintained .at a
vployed. I The present invention also is suited ‘to
temperature
of from about 240 to about 325° F.,
the preparation of improved size products from 5 and at substantially
atmospheric pressure. The
modi?ed rosins, such as heat-treated rosin, ide
relative humiditycf the heated air after drying
hydrogenated rosin, hydrogenated rosin, partially
the product, referred to’a temperature of 200°
polymerized rosin, and other modi?ed rosins,
acid, pimario acid, sapinic .acid, etc., may be em
such as are known to the art. The addition :of
is :maintained at a value below about 10%.
various modifying agents, such as waxes, ‘paraf 10 Higher temperatures of the drying atmosphere
tend to cause decomposition of the size and a
v?n oils, antioxidants, and the like, to the .size,
consequent decrease in its quality, whereas at
either vbefore orafter the drying step, also is con
lower temperatures .or higher humidities, the size
templated. The addition to the saponi?cation
product
tends to be insuniciently desiccated and,
mixture-of from about-5 to about 50% of .a paraf
therefore,
to revert ‘from the ?nely-divided con
15
?n wax, based on the dry weight of saponified
dition to a more massive state.
.
rosin, serves to provide a dry size composition
Heretofore it has been found possible to em
having advantages in certain paper .sizing proc
ploy considerably broader conditions of tem
esses.
perature and humidity in the drying step. The
.In accordance with the present invention, ‘the
‘interdependence of the present conditions of
water content of the ?nal aqueous saponi?cation
drying with other aspects of the process is asig
mixture is of critical importance to obtaining the
ni?canit
feature of the present invention.
bene?ts of the invention. The water content
When discharged into ‘the drying atmosphere,
should be not less than 22% by weight and may
‘the ‘stream of liquid saponiflcation mixture is
‘be up to ‘about 30% by weight ‘of the mixture.
‘broken up into ?nely-dispersed particles which
Preferably, the water con-tent is maintained be
are rapidly ‘and substantially completely desic
tween about ‘23 and about 28% of the mixture.
cated to form a fine, free-?owing dry powder.
"It has been found that the apparent ‘density of
The particles have a somewhat porous structure
the product is closely related to this condition.
and are readily dispersible in water. The indi
:As shown in Examples 2 and 3, decreasing the
vidual particles generally vary in size, as de
‘water content of the saponi?cation mixture to
termined by sieve analysis, according to ‘the fol
a value below 22% leads toa low density product
lowing order of gradation: 0% retained on a No.
‘that differs Jmarkedly fromthe herein-disclosed
20 mesh sieve; '70 to 80% retained on a No. 80
improved dry size. These examples illustrate the
mesh sieve; 80 to 90 % retained on a No. 140 mesh
importance .of this particular factor in providing »
sieve; and more than v‘95% retained on a No. 200
the product of high bulk density.
The desired water content in the saponi?ca
tion mixture may be ‘obtained bysaponifying the
rosin ‘with, for example, .a highly concentrated
solution of caustic alkali and subsequently add
ing to the mixture sumcient water to provide the
desired content of water. Alternatively, the con
centration of the caustic alkali may be adjusted
so as to provide ‘directly the necessary amount
of water.
In determining beforehand the
amounts of the various materials to be employed
‘to obtaina ‘desired water content, the amount of
water formed by the reaction of the saponifying
.materials .preferably is taken into account, the
necessary stoichiometric calculations based on
the saponi?cation number of the rosin and the
quantity of alkali added being readily apparent
to those skilled in the art.
I
‘At-any time before or after the saponi?cation
reaction, but prior to the drying step, the mixture
is ‘heated to a temperature of from about 340°
to about 380° 151., preferably 360° to about 375°
R, and under superatmospheric pressure. The
pressure may be the equilibrium pressure de
veloped at'the particular temperature employed,
and thus be from about 110 to about 170 pounds
per square inch, or, if desired, an external pres
sure of, say,’up to about 200 pounds per inch may
mesh vsieve. As indicated by the low proportion
voi’ particles passing ‘the ?nest sieve, the size is
substantially nondusty. Viewed in bulk, the size
‘is seen to be characterized by the uniformity ‘in
the size of the particles and by the freedom from
‘larger particles which would be less readily dis
persible in water. The individual particles are
resistant to breakage, as during handling and
packaging, and therefore have little tendency to’
‘form 1dust. The size is noncoalescing and free
?owing, and without signi?cant tendency to re
vert to a more massive state as during storage.
The present products containing less than about
3.5% moisture, when placed under a Weight of
about .38 pound per square inch at about ‘125° F.
for 24; hours, undergo substantially no change in
apparent density. Higher vcontents of moisture
tend to produce a slight settling tendency under
these conditions. The present product is readily
soluble in water, having a solubility of from about
50 to about 85 seconds in a 3% solution in water.
As produced, and without subsequent ‘treat
ments, such as compaction or compression, the
saponi?ed rosin dry size obtained has an appar
ent'density in bulk of from about 20 to about 35
pounds per cubic foot, and in the preferable cases
of from about 25 to about 30 pounds per-cubic
foot. The size product,being substantially-com
be applied to the contents of the autoclave by
pletely desiccated, contains less than about >8 %,
means of, for instance, compressed air or dry
steam. The application of such external pres 65 and preferably less than about 3.5% moisture.
This present invention thus provides a process
sure is advantageous in that it facilitates carry
‘for preparing an improved saponiiied rosin-dry
.ing'out the‘process under constant conditions and
size productand the‘product obtained. The im
hence facilitates successful practice of the inven
proved size product provides advantages of
tion.
3
The saponi?cation mixture at the stated tem 70 economic savings gained by the decreased ' cost ‘of
packaging as well as savings resulting from more
perature and pressure and containing between
economic handling and storage. Further ad
not less than 22% water and up to about 30%
vantages lie in the fact that the size product is
Water, preferably from about 23 to about 28%
readily soluble in water, free from dust or any
water, then is discharged into the drying atmos
phere to effect desiccation of the mixture and 75 substantial tendency to form dust, and non
7
2,411,824
8
coalescing. The process of the invention pro
vides the improved product without subsequent
treatments, and therefore results in improved ef
4. A method of preparing a saponi?ed rosin
dry size in the form of discrete, free-?owing,
readily water-soluble particles and having a high
apparent density in bulk, which comprises sa
ponifying rosin with a substantially chemically
equivalent amount of alkali metal alkali in aque
ous solution, heating the saponi?cation mixture to
?ciency of operation as well as in savings that are
obtained as a consequence of the properties of
the product.
What we claim and desire to protect by Let
ters Patent is:
a temperature of from about 340° to about 330° F.
1. A method of preparing a saponi?ed rosin
and under a pressure of from about 110 to about
dry size in the form of discrete, free-?owing, 10 200 pounds per square inch, providing a water
readily water-soluble particles and having a high
content in the saponi?cation mixture of from at
apparent density in bulk, which comprises the
least 22 up to about 30% by Weight of the mix
ture, and then discharging the saponi?cation mix
ture having the said water content and at said
step of discharging an aqueous mixture com
prising saponi?ed rosin and containing not less
than 22 and up to about 30% by weight of water, 15 temperature and pressure into a drying atmos
based on the weight of saponi?ed rosin and
water, at a temperature of from about 340° to
phere maintained at substantially atmospheric
pressure and at a temperature of from about
about 380° F. and under a pressure of from about
110 to about 200 pounds per square inch, into a
240° to about 325° F., thereby obtaining the sa
poniiied rosin dry size in a ?nely-divided, sub
drying atmosphere maintained at substantially 20 stantially desiccated form having an apparent
atmospheric pressure and at a temperature of
density in bulk of from about 20 to about 35
from about 240° to about 325° F., thereby ob
pounds per cubic foot.
taining the saponi?ed rosin dry size in a ?nely
5. A method of preparing a saponi?ed rosin dry
divided form containing not over about 8% mois
size in the form of discrete, free-?owing, readily
ture and having an apparent density in bulk of 25 water-soluble particles and having a high ap
from about 20 to about 35 pounds per cubic foot.
parent density in bulk, which comprises saponi
2. A method of preparing a saponified rosin
fying rosin with a substantially chemically equiv
dry size in the form of discrete, free-flowing,
alent amount of concentrated aqueous sodium hy
readily water-soluble particles and having a high
droxide solution, adjusting the water content of
apparent density in bulk, which comprises sa 30 the saponi?cation mixture to not less than 22
ponifying a rosin with a substantially chemically
and up to about 30% by weight, heating the sa
equivalent amount of an aqueous solution of an
poni?cation mixture to a temperature of from
alkali metal alkali to provide a saponi?cation
about 360° to about 375° F. and under the equi
mixture having a water content not less than 22
librium pressure at said temperature, and then
and up to about 30%, based on the weight of 35 discharging the saponi?cation mixture at said
saponi?ed rosin and water, and discharging said
temperature and pressure countercurrent to a cir
saponi?cation mixture-at a temperature of from
culating drying atmosphere maintained at sub
about 340° to about 380° F. and under a pressure
of from about 110 to about 200 pounds per square
stantially atmospheric pressure and at a tem
perature of from about 240° to about 325° F.,
inch into a drying atmosphere maintained at 40 thereby substantially completely desiccating the
substantially atmospheric pressure and at a tem
saponi?cation mixture and producing the saponi
perature of from about 240° to about 325°
?ed rosin dry size in ?nely-divided form contain
F., thereby obtaining substantially desiccated,
ing less than about 8% moisture by Weight and
having an apparent density in bulk of from about
20 to about 35 pounds per cubic foot.
6. A method of preparing a saponi?ed rosin
dry size in the form of discrete, free-flowing,
readily water-soluble particles and having a high
apparent density in bulk, which comprises sa
ponifying rosin with a substantially chemically
equivalent amount of sodium hydroxide in the
?nely-divided particles of saponi?ed rosin dry
size in a form having an apparent density in bulk
between about 20 and about 35 pounds per cubic ,
foot.
3. A method of preparing a saponi?ed rosin
dry size in the form of discrete, free~?owing,
readily water-soluble particles and having a high
apparent density in bulk, which comprises sapon
ifying rosin with a substantially chemically
equivalent amount of aqueous sodium hydroxide
to provide a saponi?cation mixture containing
not less than 22 and up to about 30% by weight
of water,’ heating the saponi?cation mixture to
a temperature of from about 340° to about 380°
F. and under a pressure of from about 110 to
about 200 pounds per square inch, and then dis
charging the saponi?cation mixture at said tem
perature and pressure countercurrent to a cir
form of a concentrated aqueous solution, heat
ing the saponi?cation mixture to a temperature
of from about 360° to 375° F. and under a pres
sure of from about 110 to about 200 pounds per
square inch, providing a water content in the
saponi?cation mixture of from at least 22 up to
about 30% by weight of the mixture, and then
discharging the saponi?cation mixture having
60 the said water content and at said temperature
culating drying atmosphere maintained at sub
stantially atmospheric pressure and at a tern-'
perature of from about 240° to about 325° F.,
thereby substantially completely desiccating the *
saponi?cation mixture and producing the saponi
?ed rosin dry size in ?nely-divided form contain- '
ing less than about 8% moisture by weight and
having an apparent density in bulk of from about
20 to about 35 pounds per cubic foot. _
and pressure into a drying atmosphere main
tained at substantially atmospheric pressure and
at a temperature of from about 240° to about
325° F., thereby obtaining the saponiiied rosin
dry size in a ?nely-divided, substantially desic
cated form having an apparent density in bulk
of from about 20 to about 35 pounds per cubic
foot.
JAMES K. FARRELL.
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