Note: Descriptions are shown in the official language in which they were submitted.
~0~'~5~
This invention relates to an improved method for
the sizing of paper and to the paper thus prepared. More
particularly, the invention relates to an improved method of
sizing paper and paperboard products using a mixture comprising
hydrophobic substituted cyclic dicarboxylic acid anhydride and
polyoxyalkylene alkyl or alkyl-aryl ether or the corresponding
mono- or di-ester under specified conditions.
As used herein, the terms "paper and paperboard"
include sheet-like masses and molded products made from fibrous
cellulosic materials which may be derived from both natural and
synthetic sources. Also included are sheet-like masses and
molded products prepared from combinations of cellulosic and
non-cellulosic materials derived from synthetics such as poly-
amide, polyester and polyacrylic resin fibers as well as from
mineral fibers such as asbestos and glass.
It is recognized that paper and paperboard are often
sized with various hydrophobic materials including, for example,
rosin, wax emulsions, mixtures of rosin with waxes, ketene
dimers, isocyanate derivatives, fatty acid complexes, fluoro-
carbons, certain styrene-maleic anhydride copolymers, as well
as the substituted cyclic dicarboxylic acid anhydrides more
particularly described hereina~ter. These materials are
referred to as sizes or sizing and they may be introduced
during the actual paper making operation wherein the process is
known as internal or engine sizing. On the other hand, they may
be applied to the surface of the finished web or sheet in which
case the process is known as external or surface sizing.
Sum~ary of the Invention
It is the object of this invention to provide
improved sizing of paper which is characterized by its reduced
water and ink absorption as well as its increased .
-- 1 --
. ,
10~
resistance to aqueous acid and alkallne solutLons.
The sizing compound8 contemplated for U9Q in our
sLze mixtures are substituted cyclic dicarboxylic acid
anhydride~. More specifically, the sizing compounds
correspond to the following structural formulas:
.
(~) 0 ~ ~-R - R'
\ C'
.
wherein R represent~ a dimethylene or trLmethylene radical
and whereln R' i8 a hydrophobic group containing more thsn
5 carbon atoms which may be selectad from the cla8s conslsting
of alkyl, alkenyl, sralkyl, or aralkenyl group~; ~nd
'
Rx
0 H CH2
(B) C - C - CH - CH ~ CH - R
1. ` ' ' .
\C CH
. 0~
wherein R i8 an alkyl radical containing at least 4 carbon
atoms and R Ls ~n alkyl radLcal containing ~t least 4 carbon
~toms, and Rx and Ry Qre interch~ngeable.
Specific examples of ~izing compounds fallLng
within structure`(A) lnclude iso-octadecenyl succlnic acLd
anhydride, n-hexadecenyl succinic ~cid anhydrid¢, dodecenyl
~uccinic acid anhydride, dodecyl succinic acid anhydride,
decenyl 6uccinic acld anhydrlde, octenyl succinic acid
anhydride, triisobutenyl succinlc acid anhydrldeJ etc. Siz-
ing compounds in whlch R' contains more than twelve carbon
-
104;~
atoms are preferred. The sizing compounds of structure (A) are
fully described in U.S. Patent No. 3,102,064 issued August 27
1963.
Specific examples of sizing compounds falling within
structure (B) include (l-octyl-2-decenyl)-succinic acid
anhydride and (l-hexyl-2-octenyl)-succinic acid anhydride.
The sizing compounds of structure (B) are fully described in
copending Canadian application assigned to the assignees of the
pre~ent invention, Serial No. 186,235 filed November 20, 1973.
According to prior art teachings, in order to
obtain good sizing with the described sizing compQu~d iit is
desirable that they be uniformly dispersed throughout the
fiber slurry in as small a particles size as is possible to
obtain. Tn usual practice of adding these sizing compounds
to the paper stock prior to web formation, therefore, the
sizing compound is added in the form of an aqueous emulsion
prepared with the aid of emulsifying agents.
These prior art emulsification techniques which
utiliz~d emulsifying agents which acted as protective colloids
such as cationic or ordinary starches, gum arabic, gelatin,
cationic polymers or polyvinyl alcohol, or that utilized surfact-
ants in ~combination with the aforementioned emulsifying agents,
however, suffered from several inherent deficiencies. A primary
deficiency concerned the necessity of utilizing relatively com-
plex, expensive and heavy equipment capable of exerting high
homogenizing pressures, together with rigid procedures regard-
ing emulsifying proportions and temperatures, etc., for producing
a satisfactory emulsion of the substituted cyclic dicarboxylic
; acid anhydride size. Moreover, attempts to use the surfactants
alone, i.e. without emulsifying agents, have been found to be
totally unsuccessful from a commercial view. With the use of a
surfactant, according to prior art, it has not been possible
104;~S11
to form a stable, small size particle emulsion and/or the
emulsion did not produce sufficient sizing performance. In
some instances, the resultant emulsion detrimentally affected
other properties of the sized paper, for example, loss of wet
strength. Another drawback noted with various emulsions
prepared with certain surfactants, is demonstrated where on
aging of the treated paper, many small hydrophilic spots were
formed as evidenced-by an ink dip test.
Additionally, the use of many surfactants was found to
create severe operational problems in the papermaking process
- such as severe foaming of the stock. By the process of this
invention, use of heavy equipment for producing an emulsion is
eliminated, and more flexibility in preparing and utilizing the
sizing mixure is permitted. Moreover, in preparing emulsions of
the size mixtures herein according to the method of this
invention, a smaller particle size-is readily achieved and the
stability of the resultant emulsions is generally superior to
those of the prior art. Additionally, use of the size mixtures
of this invention results in significantly improved sizing perfor-
mance (i.e. improved sizing is achieved with a given concentrationof size), and also results in the improved operability as evi-
denced by reduced build-up of fiber and sizing agent on the
press rolls of the paper machine.
It has now been discovered that size mixtures of
substituted cyclic dicarboxylic acid anhydride and polyoxyalkyl-
ene alkyl or polyoxyalkylene alkyl-aryl ether or the correspond-
ing mono or di-ester in specified proportion readily yield
improved sizing emulsions witho,ut the necessity of utilizing
heavy homogenizing equipment. These mixture have been found to
emulsify by merely stirring or passing through a mixing val~e or
an aspirator. The emulsion thus produced is adequately stable
- 4 -
10~
for commercial purposes and possesses a sufficiently small particle size
to produce excellent sizing of the resultant web.
It is also a feature of this invention that in one variation of
the method, the size mixture may be used in the sizing method without any
prior emulsification step. In this variation, the mixture is added to the
paper stock preparation system with good agitation prior to the refining
of the stock. The usual agitation of the stock when passing through refiners
has been found sufficient to emulsify the mixture so as to produce excellent
sizing properties in the resultant sized web.
The polyoxyalkylene alkyl or polyoxyalkylene alkylaryl ethers
or corresponding mono- or di-esters useful herein comprise polyoxyethylene
or polyoxypropylene alkyl and alkyl-aryl ethers or esters containing 5 - 20
polyoxyethylene ~or polyoxypropylene) units wherein the alkyl radical
, contains from 8 - 20 carbon atoms and the aryl radical is preferably phenyl.
The preparation of these ethers and esters is known ~o those skilled in the
art. Typical commercially available products useful in the method of this
invention include Renex* 690 sold by ICI America, Inc., Wilmington, Delaware,
Triton* X-100, Triton* X-205 and Triton* N-57 sold by Rohm and Haas Co.,
Philadelphia, Pennsylvania, Tergitol* NP-27 and Tergitol* TMN sold by
Union Carbide Corporation, New York, New York, and Igepal* C0-630 sold by
GAF Corporation, New York, New York, as well as PEG 400 Monooleate supplied
by Finetex, Incorporated and PEG 600 Dilaurate sold by Armak Chemical
Division of Akzona, Incorporated.
In accordance with the method of this invention, the size mixture
is formed by mixing 80 to 97, preferably 90 to 95, parts of the aforemen-
tioned cyclic anhydride with 3 to 20, preferably 5 to 10, parts of the
selected polyoxyalkylene alkyl or alkyl-aryl ethers or esters. It is re-
cognized that various combination of size compounds and/or polyoxyethylene
* Trademark
~7
~0~;~5~1
alkyl or alkyl-aryl ethers or es~ers may be used Ln preparLng
a particular size mixture, as long as they fall within the scope
of'this invention. In order to prepare an emulsion, the
size mixture is generally added to water in sufficient quantity
S so as to yield an emulsion containing the substituted cyclic
dicarboxylic acid anhydride in a concentration of from'about
0.5 to 20%, by weight. The aqueous mixture is thereafter suffici-
ently emul-sified merely by stirring with moderate to high speed
agitation or by passing it'through a mixing valve, aspirator or
orifice -so that the average particle size of thè resultant
emulsion will be less than 3 microns. It is noted that in prepar-
ing the emulsion, it is also possible to add the components of
the size mixture to the water separately, and the emulsion may
be prepared by a continuous or batch method.
As to actual use, no dilution of the emulsion is
generally necessary. The thus-prepared emulsion is simply added
to the wet end of the paper making machine or to the stock
preparation system so as to provide a concentration of the
substituted cyclic dicarboxylic acid anhydride of from about
0.01 to 2.0% based on dry fiber wei'ght. Within the mentioned
range the precise amount of size which is to be used will depend
for the most part upon the type of pulp which is being utilized,
the specific operating conditions, as well as the particular
end use for which the paper is destined. For example, paper
which wil]: require good water resistance or ink holdout will
necessitate the use of a higher concentration of size than paper
which will be used in applicat'ions where excessive sizing is
not needed.
As another embodiment of this invention, instead of
adding the size emulsion to the stock preparation system or wet
end, the size emulsion may be sprayed onto the surface of the
formed web at any point prior to the drying step In this embodi-
ment, the emulsion is used in the concentrations as prepared, and
is sprayed onto-the web so as to provide a concentration of size
of from about 0.01 to 2.0% based on dry'fiber weight.
-- 6 --
104;~511
.
Where the qize mixture Ls added to the ~tock
preparation system prior to refining, it i8 unnecessary to
carry out a separate emulqificatlon step. The amount of
size mixture added in this manner should be such as to
provide a concentration of RubstLtuted-cyclic dicarboxylic
acid anhydride of from about 0.01 to 2~'0% based on dry
fLber weLght.
An important actor in the efective utilization
of the size mixtures hereLn involves their use in con~unction
with a material which i8 either cationic or i8 capable of
ionlzing or dissociating in such a manner a~ to produce one or
more cations or other positively chsrged moieties. These
cationic agents, a~ they hereinater will be ref~rred to-, have
been found u~eful as a mean~ for aiding the retention of the
-~u~stituted cyclic dicarboxylic acid anhydrides as well as for
~r~ git~ ~att~é~ L~t~D clo~e proximity to the pulp fibers.
Among the materials which may be employed a~ cationic agents
Ln the method of this invention, one may li-st alum, aluminum
chloride, long chaLn fatty~amines, amLne-containing synthetic
polymers (primary, secondary, tertiary or quaternary amine),
sodium alumlnate, chromic sulfate, substituted polyacrylamlde,
animal gluej catLonic thermosetting re~ins and polyamide
polymers. Of particular use as cationic agents are various
cationic starch derivatives includLng primary, secondary,
tertiary or quaternary amine starch derivative~ and other
cationic nltrogen ~ub~tituted starch derivatives~ as well as
cationic sulfonium and pho~phonium starch derlvatives. Such
derivatives mfly be prep~red ~rom alI types of ~tarche~ includ-
ing corn, tapiocs, potato, waxy maize, wheat and rice, More-
over they may be in theLr original granule form or they may
be converted to pregelatinized, cold water soluble products.
Any of the above noted cationic agents may be
added to the stock, i:e. the pulp slurry, either prior to,
along with or after the additlon oE the size mixture or ~ize
104;~511
,
emulsion, and mny take place at any point in the paper maklng
proces~ prlor to the ultlmate conversLon of the wet pulp
into a dry web or sheet.
With re~pect to the amount of cationic agent
necessary, under ordinary cLrcumstances, the cfltlonlc agent
is added to the stock ~ystem Ln an amount of at le~st 0.01%,
preferably 0.025 to 3.0%, bfl8ed on dry fiber wei~ht. While
smounts in excess of 3%, may be used, the benefit~ of using
lncréased amounts of catlonic agent for sizing purposeR ~re
usually not economlcalIy ~stified.
~ Subsequent to`the additLon of the slze emulsion and
c~tionlc agent, the web i8 ormed and dried on the papermaking
machLne in the ugual manner. Whlle full slzlng 18 generally
- schieved immedLately of the paper machine, further improve-
ments in the water reslstance of the paper prepared with the
51ze mLxture8-of this invention may at time8 be obtained by
curing the resulting web8, ~heets or molded products. ThLs
curing proce~s generally involves heating the paper at
temperatures in the range offrom 80~oito 150C for a period
of fro~ 1 to 60 minutes. However, it i8 to be noted that
post curing is not es~entlal to the successful operation of
the Improved sizing method described herein.
The 8 ize mixturesio~ the present invention may, of
course, be succe~sfully utili~ed for the sizing of paper
prepared from all type~ of both c`ellulosic and combinations
o cellulo8ic with non-cellulosic fibers. The hardwood or
softw~od cellulosic flber~ which may be used include bleached
and unbleached sulfate ~kraft), bleached and unbleached
sulfite, bleDched and unble~ched soda, neutral ~ulfite semi-
chemical, groundwood, chemi-groundwood, and any combination
of these fibers. ~hese designation8 reer to wood pulp
fiber~ which have been prepared by means of a variety of
proce~ses which are used in the pulp and paper industry.
In addition, synthetic cellulo31c fibers of the viscose rayon
or regenerated cellulo~e type can al90 be used, fl8 well as
- 8 -
:
iO435~1
recycled wa~te p~pers from various source~.
All types of pigments and fillers may be Ddded
to the paper in the usual manner whicb iB to be sized in
accord~nce wLtll thls Lnvention. Such material~ include
clay, talc, tLtanium dioxLde, calcium carbonate, calcLum
sulfate, and diatomaceou~ earths. Other additlves includln8
alum, as well as other slzLng compounds can fll90 be used
with the size mixture8 described heraLn.
The uBe o the size mlxtures descrLbed herein ln
accordance wLth the method of this Lnventlon ha3 been found
(as will be illustr~ted ln the exumples) to yLeld paper
.
having improved size propertie~, for example, resi8tance to
water or ucLdic lnk solutLons. In othe~ words, a specLfied
degree of size propertles in paper can be achieved with a
smaller amount o slze when the slze is utilized in accord~nce
with the method of thi8 lnvention rather than by method8 known
ln the p~ior art,
Moreover, it is a further advantage ~hat use of
the 8ize m~xtures herein i8 not limlted to any particular pH
range whfch thus allows for their utllizatlon ln the trestment
of neutral and alkallne pulp, as well as acidlc pulp. The
size mixtures may thus be u8ed ln combination with alum,
whLch la very commonly u~ed in makLng paper, as well a~ other
acldic m~terials. Conver~ely, they may also be used with
calc~um carbonate or other ~lksline materials in the ~tock.
A further advanta~e o these size mixture8 i8 that they do not
detract sib~Lflcantly from the strength of the paper ~n the
nor~l concentrations employed ln the Lndu~try and when used
with certsin ud~uncta will~ infact, increase the strength of
the finished sheets. An addltional advantage found in the
u~e of these size mLxtures i8 that only drying or mild curing
conditions are requLred~to develop full slzing value.
The following exsmples will further LllustratQ the
embodiment of the present inventlon. In these ex~mples, all
parts given are by weigllt unle8s otherwise noted.
_ 9 _
.
1~43S11
EX~IPLE I
rhLs example illu3trate~ the use of a ~ize mixture
repre~2ntative of the size mLxtures of this invention
utilized in the form of ~n aqueous emulsion. This emuls10n
i8 compared, in terms of particle size and water r-e~i~tance
of ~he rèsulting ~ized paper, with a conventionsl emulsion
whereln substLtuted cycllc dicarboxylic acid anhydride Ls
emulsif1ed wLth cationic starch. A urther comparison is
msde with ~ rosin/alum slzing method as commonly employed ln
the paper industry. The much greater ease of emul~ification
of the 8ize mixtures of this lnvention Ls also demonstrated
by the procedure-u~ed in prepar~n~ the sizing emulsion~ prior
to their addltion to the pflper stock sy~tem. The ability to
size paper effectively with or without alum in the stock i3
al80 shown.
The size mixtur~ was prepared by combining (A) 10
parts of ~ polyoxyalkylene alkyl-aryl ether wherein thè slkyl
group contained 9 carbon atoms, the aryl r~dics~ was phenyl
and the polyoxyalkylene moiety was fonmed with 10 moles of
ethylene oxide ~Renex 690~ ~d (B) 90 parts of substltuted
cyclic aïc~rboxyilc ac1d anhydrLde wherein the alkenyl groups
of the mixed anhydrides contained 15 to 20 carbon atoms
~hereinafter referred to R~ ASA). Other material~ equivalent
to Rene~ 6gO include Triton N~101 and Igepal GO-63~.
An emul~ion was t`hen formed by ugitatlng 2 parts of this mixture
with 98 parts of water using a propeller-type mixer at moderate
speed for 10 seconds (F.mul~ion ~ A simll~r emulsion w~s
al30 ~ormed by pà~sin~ thls size mixture through a slmple
a~plrator, together with ~ constant stre~m of water, ~o yield
lX concentration of size mixture in one pass, The emulsion
W~8 thus ormed almost inatantaneously (Emulsion ~2).
For comparL~on, 8 conventional aqueous emulsion of~
ASA was prepared by first cooking 10 parts of the beta-diethyl
- 10 -
104;~
, . . .
aminoethyl chloride hydrochloride ether of corn starch, who8e
preparation i8 described in ~xample I o~ U, S Pstent No.
2,813,093, in 90 part~ of water whLch was heated in a boiling
water bath. The dispersLon of the cationic starch derivative,
after being cooked for 20 minute~, was cooled to room
temperature and transferred to a high speed agitator whereupon
5 parts of ASA were slowly added to the agitsted di8per~ion.
Agitation was continued for about 3 minutes snd the resulting
emul~ion wa~ then diluted by the addition of water to equal a
total of 1,000 parts, 0.5% solids (Emulsion #3).
Calcuiated amountA of the emulsions prepared as
descrlbed above were added'to aqueous slurrLes of bleached
sulfate pulp having a William~ freeness of 400, a consistency
of 0.5% and a pH of about ~. 6, 80 as to yield the ~ollowing
lS concentration8 of ASA on dry fiber weLght: 0.10, 0.20 and
0.40Z, The cationic ~t~rch'u~ed in making Emulsion #3 was ~,
sdded to the respective pulp ~lurry subsequent to the addltlon
of Emulsions #1 and #2 in a concentration of 0~4% on dry fiber
weight to retain these'materials in the sheet. In another
variation of this procedure, 4% alum, based on dry fLber weight,
was added to the pulp slurry before addition of the sizing
emulsion~. Sheets were formed and dried in accordance with
TAPPI ~tandards, then cured for 1 hour at 105C. and
conditloned overnight at 72 F. and 50% R.H. before testin8.
The basi~ weight of these ~heets was 55 lbs./ream (24" x 36" -
500 sheet~). ' ' '
In comparing the water resistance of these sheet~,
use was made of a dye test employing cryGtals of potassium
permanganate and an acid lnk psnetration test. In the dye test
seversl cry~tal~ of pota~8ium permanganate are placed on the
upper ~urface of a swstch of test paper which i8 then set afloat
in diQtilled water at room temperature. As the water is
ab~orbed into the paper the cry~tal~ are moi~tened and
impart a characteristlc deep violet color to the paper. The
~4351~ .
. 1 . , .
.
time measured in second~ required ~or an end-point where
three colored spots first appear on the paper surface 1~
noted and i9 Ln dlrect relation to the water resistance since
8 more water re~istant paper will retard the moistening o~
the~permangnnate crystals which had been placed upon it8 upper
8urface.
The acid Lnk penetration test ls a compari60n test
wherein 8 ~watch of test paper is floated in a dish of acid
ink (pH 1.5) at 100F. and the time measured in seconds
. required ~or the ink to penetrate through the paper to reach
~n end-point where about 50% of the paper is colored is noted.
The following table presents data on the various
paper sheets which were compared in the described testing
procedures.
- 12 -
511
TABLE 1
~veruge %
Particle by Acld Ink
Size of Weight Penetration ~MnO4
Sheet Slzing Emulsion of Dry Alum ~Time in (TLme in
No. Emul~lon ~Microns) Pulp Addition Seconds) S~conds)
1, Emul~ion #1 ~ 1 0,1 ~one 25 53
2. Emulsion #1 c 1 0.2 " 275 72
3. Emulsion #1 ~1 0.4- " 430 77
4. EmulsLon #2 c l 0.1 " 70 53
S. Emulsion ~2 Cl 0.2 " 140 . 74
6. Emulsion #2 1 0.4 " 320 87
7. EmUlBion #3 2-3 0.1 " 12 54
(Control)
8. Emulsion #3 2-3 0.2 " . 40 67
(Control)
9. Emul6ion ~3 2-3 - 0.4 " 65 75
(Control)
10. Emulsion #1 ~ 1 0.1 4% 100 58
11. Emulsion #1 C 1 0.2 4% 145 70
12. Emulslon #1 < 1 0.4 4% 190 87
; 13. Emulsion #2 - ~1 0.1 47O 110 57
14. Emulsion #2 .Cl 0.2 4% 150 68
15, Emul~on #2<l 0.4 4% 205 88
16. Emul~ion ~3 2-3 0,1 4% 90 65
(Control)
17. Emulsion #3 2-3 0.2 47O 130 . 73
(Control)
18 . Emul~ ion #3 2-3 0.4 4% 170 84
L9. Rosln (Control) - 1,0 4% 55 67
20, Blank - None None 0 0
- 13 -
~0~a3Sll
The above data clearly ~hows the greater ease of
preparation and ~uperiority of the ~ize mLxtures of this
invention, both in terms o the small particle size of
emul8Lon8 formed with these compo~ltions and in tèrms of
water resistance imparted to the sized paper over a range
Ln level of addition typically employed in the industry. It
i8 al80 cLear that the~e compo~ition6 demonstrate superior
sizing both in near-neutral and alum-contalning (acldic)
stock 8 y8 tems.
EXAMPLE II
This example illustrate8 the use of~ize mixtures
of this invention wherein various s~bstituted cyclic
dLcarboxylic acid anhydrides are utilized ~n mixtures with
polyoxyalkylene alkyl and alkyl-aryl ethers.
In this example, the polyoxyalkylene alkyl aryl
ether was the same material described in Example I-and was
mixed Ln a ratlo of 20 parts with 80 parts of the anhydride.
- The substltuted cyclic dicarboxyIic acid anhydrides
incorporsted in the mixtures of this example were then
var~ed as follows: Mixture #l - the ASA descrlbed ln
Example I; Mixture #2 - iso-octadecenyl succinic acid anhydrlde;
Mixture $3 - hexapropylene succlnlc àcid anhydride;
Mixture #4 -(1-octyl-2-decenyl)~uccinic acid anhydrLde, i.~.
the reaction product of maleic anhydride and octadecene-9~
Emulsions of these mixture~ were prepared Ln the same manner
u~ed to prepare Emulsion #l described in Example I.
Calculated amounts of the emulsions were added to
separate aqueous slurries of bleached ~ulfate pulp having a
freeness of 400, a consistency of 0.5% and a pH of about 7.6.
~he cationic starch of Example I was also added to the
separate pulp slurries. Sheets were formed and dried in
accordance to TAPPI standards and thereafter conditloned and
tested as de~cribed ln Example I. The basi~ weight of these
- 14 -
10~3SlI
sheets was 55 lbs./ream (24" x 36" - 500 sheets). .All
additions were made at a concentration of 0.2% substituted
cyclic dicarboxylic acid anhydride.and 0.4% cationic starch by
weight of dry pulp. Following were the results obtained:
TABLE 2
Average . Acid Ink
Particle Size Penetration KMnO4
Size of Emulsion (Time in (Time in
Mixture No. (Microns) Seconds) Seconds)
1 ~ 1 225 73
2 1-2 -lO0 40
3 < 1 240 81
4 < 1 -- 600 8~
This example clearly shows that various substi-
tuted cyclic dicarboxylic acld anhydrides may be used to prepare
size mixtures within the scope of this invention.
EXAMPLE III
. This example illustrates the use of size mixtures of
this invention wherein different polyoxyalkylene alkyl or alkyl-
: 20 aryl ether or the corresponding mono- or di-ester compounds are
- -utilized in the mixture with substituted cyclic dicarboxylic acid
anhydride.
In this example, the substituted cyclic dicarboxylic
acid anhydride was the same material (ASA) described in Example I
while the polyoxyalkylene alkyl and alkyl-aryl ether or ester
compounds used in the size mixtures were varied, Size mixtures
used in this example were prepared as follows: Mixture #l -
5 parts of the polyoxyalkylene alkyl-aryl ether described in
Example I were mixed with 95 parts ASA; Mixture #2 - 15 parts
of the polyoxyalkylene alkyl-aryl ether described in Example I
were mixed with 85 parts ASA; Mixture #3 - 10 parts of a
- 15
1043511
polyoxyalkylene alkyl-aryl ether wherein the alkyl group
contains 9 carbon atoms, the aryl radical is phenyl and the
polyoxyalkylene moiety was formed with 5 moles of ethylene oxide
(Triton N-57) were mixed with 90 parts of ASA; Mixture #4 -
10 parts of a polyoxyalkylene alkyl ether wherein the alkyl groupcontains 12 carbon atoms and the polyoxyalkylene moiety was
formed with 6 moles of ethylene oxide ~Tergitol TMN) were mixed
with 90 parts ASA; Mixture #5 - lO parts of a polyoxyalkylene
alkyl-aryl ether wherein the alkyl group contained 9 carbon atoms,
- 10 the aryl radical was phenyl and the polyoxyalkylene moiety was
formed with 15 moles of ethylene oxide (Tergitol NP-33) were
mixed with 90 parts ASA; Mixture #6 - lO parts of a polyoxy-
ethylene monoleate ester wherein the molecular weight of the
polyoxyethylené moiety was 400 (PEG 400Moncoleate) were mixed
with 90 parts of ASA; and Mixture #7 - lO parts of polyoxyèthylene
dilaurate ester wherein the molecular weight of the polyoxyethyl-
L
ene moiety was 600 (PEG 600 Dilaurate) were mixed with 90 partsof ASA. Each ofthese mixures was then agitated in water to
yield emulsions containing 2 parts size mixture and 98 parts of t
water. The emulsions were then addèd to a 0.5% consistency pulp
; slurry containing bleached sulfate pulp beaten to a freeness of
400 and at a pH of approximately 7.6 to yield 0.2% ASA on weight
of dry fiber. The cationic starch described in Example I was
then added to the pulp slurry to yield 0.4% cationic starch on
weight of dry pulp. Handsheets thereafter were formed,
conditioned and tested in the dye test as described in Example I.
Following were the results obtained.
'
r
- 16 -
104351~
TABLE 3
Average Particle
Size of Emulsion KMnO4
-Size'Mixture No. (Microns) ' (Time'in'S'econds)
1 1-2 . 98
2 ~ 1 93
3 < 1 104
4Approx. 1 99
: ~ 5Approx. 1 96
6Approx. 1 76
7 -Approx. 1 86
- This examplè clearly shows that various polyoxy-
ethylene alkyl and alkyl-aryl ethers and the corresponding
mono- and di-esters, within the scope of this invention, can be
used interchangeably in size mixtures.with substituted cyclic
dicarboxylic acid anhydrides to yield excellent sizing
performance.
EXAMPLE IV
; ' This example illustrates the use of our novel size
mixtures by direct addition to a papermaking stock system in .
unemulsified form.
Size Mixture #l prepared from 90 parts ASA (described
in Example I) and 10 parts.of polyoxyalkylene alkyl-aryl ether
(described in Example I) was added directly to a slurry of
bleached sulfàte pulp at l.5~/O consistency in a laboratory
~' Valley beater and beaten very lightly for a few minutes.
Similarly,Size Mixtures #2 and #3 were prepared from 90 parts
ASA and 10 parts PEG 400Monooleate or 10 parts PEG 600'Dilaurate.
' respectively,and these mixtures were also added directly to the
slurry. The Fulp was then diluted to 0.5% consistency, and
0.4% on dry fiber weight of the cationic starch described
: ~ - 17 -
1()43S1:1
in Example I was added separately to the slurry to act as a
retention aid during sheet formation. Sheets were then
formed, conditioned and tested in the dye test as described
in Example I. The basis weight of these sheets was 55 lbs./
ream (24" x 36" - 500 sheets~. Following are the results
obtained.
TABLE 4
~/0 ASA by Weight KMnO4
Size Mixture No. on Dry Pulp (Time in Seconds)
,
0 1 0.2 75
2 0.2 40
- 3 0.2 39
Blank None 0
The self-emulsifying properties of these size
mixtures are demonstrated by the excellent sizing value
achieved when they are added to the stock without prior
- emulsification in water. Consequently, the considerable
:
,
- 17a -
1()4~1~ .
`:
ease and versatility in the use of the size mixtures of
this lnvention can be readily seen.
EXAMPLE V
.
This example illustrates the abLllty of ~ize
mixtures-of this invention to readLly 8 i ze paper containing
I high levels of inorganic filler. In thLs example, the
- size mixture used was the same as de~crlbed in Example l.
Prior to addltion, the slze mixture was emulaified (Emulsion A)
~ in the same manner as described for the prepsration of
Emulsion #2 ln Example I.-- For comparison purposesJ a
conventional sizing emulsion (Emulsion B) was prepared in
accordance with the method described to prepare Emulsion #3
in Example I. Each emulsion was then added to 1) a 0.5%
consistency ~tock slurry containLng bleached ~ulfate pulp
with 20% Kaolin clay and 4% alum on dry fiber weight; and
2) a 0.5% consistency stock siurry containing blesched sulfste
pulp with 20% calcium carbonate on dry fiber weight. The
pH of the calcLum carbonate-contaLning stock slurry was
approximately ~.5, while the pH of the clay-containing slurry
was approximateiy 5.5. Each emul~ion wss added to the stock
at a level to yLeld 0.4% ASA on dry fiber weLght. For
retention purposes, 0.8% of the cationic starch described in
Example I wa~ added to the pulp slurry following additlon of
Emulsion A. Sheets of 55 lbs.~lream (24" x 36" - 500 sheets)
basis weight were then formed and condLtioned in the manner
described in Example I and tested sccordingly. Following
are th¢ results obtained:
- 18 -
.
.,
1043511
- T~BLE 5
.
Acid Ink
Sheet Size Added FillerPenetr~tlon KMnO4
No. Added (Time ln Sece.) (Time Ln Sccs.)
1Emul8ion A 20% Clay115 75
2Emulsion A 20% CaC03450 68
3Emulsion B 20% ClaylO0 70
~Control)
4Emul~on B 20~h CaC03325 56
lQ (Control)
5Blank 20% Clay 0 0
The above data clearly shows-the improved ~izing
achLeved with the slze mixture~ o~ thls invention in
highly filled sheet8 and under both acid and alkaline stock
conditions.
: '
EX~PLE VI
.
This example lllustrate8 the use of a 3ize mixture
representative of the slze mixture6 of this invention to
~ize paper made:~ith different types of pulp8.
In thi~ example, the 8ize ~ixture u8ed W88 the same
as described in Example I and was emuls~fied ln the same
ma~ner as described ~or the preparation of EmulsLon #2 in
Example I. The emulsion wa~ then added to various pulp
slurrles prepared at 0.5Z consLstency, a freeness of 400 and
pH of approxlmately 7.6 in amount~ to yleld 0.2~ ASA on dry
fiber weight. In all ca~e~, 0.~% on dry flber weight of the
; catLonic starch described in ExMmple I was added to the pulp
slurries separ~tely to retain the 8ize mixture during sheet
formation. Sheet9 of 55 lb8.ream (24" x 36" - 500 sheet~)
basis weight were then formed from each pulp slurry conditioned
and tested in the dye teRt in the manner de~crlbed ln Example I.
Following are the re~ults obtained:
.
- 19 -
104;~
TABLE 6
K~nO4
Sheet No Tvoe oE Pul~ (Time in Second~
1. Bleached Hardwood Sulfate 69
2 Bleached Softwood SulfLte 83
3 -Unbleached Softwood Sulfate 76
4 Groundwood' 58
' The above data, together with data in other'examples,
clearly shows that the si~e mixtures'of this invention can be
effectively used to sLze variou9 types of pulp8 commonly
used in.the manufàcture of paper.
EXAMPLE VII
' ~ is example illustrates the use of varlous types
of catlonic agents in con~unctLon.wlth'the size m1xtures of
thi~ invention. In this example, the size mixture used was
the same a~ described in Example I.snd was emul~ified, prior
to the addition to the pulp slurry, in the same manner
d'essrlbed for the preparatlon of EmulsLon #2 in Example I.
The emulsion was added.to purtions of a 0'.5% consistency
pulp slurry containing bleached sulfate pulp beaten to a
' . ~freeness of 400. Subsequent to the addition of size emul~ion,
.. different cationLc agents were added to separate slurries in
order to retain the size emulsion in the web during-sheet
- formation. An amount of size emulsion was added so as to
25 . yield 0.2% ASA on dry iber weight in'each case, while the ' ''~
amount of cationic agent was varied. Sheets of 55 lbs./ream
(.24" x 36" - 500 sheets) basi~ weight were then ~ormed from
each slurry, conditioned and tested in the manner described
ln Example~I. Following are the results obtained;
_ 20 -
la4~
T~BLE ?
Acid Ink
% on Dry Penetration KMnO4
Sheet Fiber (Tlme in (Time in
5 No. Cationic Agent Weight Second~) Seconds)
1 Cationic corn starch 0.4 135 72
2 Polyflminoethyl acrylate resin 0.2 600 76
3 Polyamide-amine resin 0.2 600 85
4 PDlyethylene imine resln 0.2 85 50
Pol~acrylamide-~mine resln 0.2 30 68
6 Cationic potato starch Q.4 120 70
7 Alum 4.0 65 77
8 None (Control) - 0 0
The above data clearly shows that various cationic
agents can be effectively employed to retain the size
mixtures of this invention in the web during the sheet forming
stage.
EXAMPLE VIII
This example illustrates the improved operability
of these sLze mixtures when used on an actual papermaking
machine. More specifically, this example Lllustrates the
elimination of buildup and picking tendencie~ crea~ed by
sizing agents on the wet press rolls of a paper machine. This
buildup of fiber on the wet press rolls causes disruptlon of
the sheet surface and, in severe ca8es, will actually tear
the sheet causing the traveling web to break at th~t point.
Sizing was me~sured in thi3 ex~mple by means of a Cobb test
run ~n the top ~ide of the sheet in accord~nce with TAPPI
5tandard M~thod T441 os-69. This test measures the amount of
water absorbed by the sheet surface in a specified period of
time (in this case, 2 minutes) and is expre~sed in term~ of
~rams per ~q. meter. Thus, lower values represent greater
wster resistance and better ~izin~.
- 21 -
104~511
A series of tests were conducted on a Fourdrinier paper machine
wherein the press section consisted of two main presses followed by a smooth-
ing press, each press consisting of a top and bottom roll. The first press
consisted of a straight-through plain press with a standard rubber covered
top roll as commonly used in the industry and the second press was a plain
reversing press with a composition (Microrok*) covered top roll, also common-
ly used in the industry. The smoothing press consisted of a straight-
through set of rolls with a metal surfaced (Press-Tex*) top roll and com-
position-covered (Micromate*) bottom roll. The basic papermaking furnish
consisted of a very lightly refined mixture of approximately 80% bleached
hardwood kraft pulp and 20% bleached softwood kraft pulp. The sizing agents
were added continuously to the stock preparation system and a sheet of paper-
board was formed at approximately 123 lbs. per 3,000 sq. ft. basis weight.
Buildup on the press rolls due to picking was ascertained under the indicated
conditions on each of the p~ess rolls and noted in descriptive terms: None,
slight, moderate, heavy, etc.
Sizing emulsions were prepared as follows: Emulsion A (a control)
was prepared by cooking the cationic starch described in Example I at 5%
solids at 200F. for 30 minutes. The cooked starch solution was then cooled
to 130F. and mixed with the substituted cyclic dicarboxylic acid anhydride
of Example I (ASA) and emulsified by passing through commercial homogenizing
equipment at 300 p.s.i.g. Emulsion B, representing an embodiment of this
invention, was prepared by continuously premixing through a static mixer
90 parts of ASA with 10 parts polyoxyalkylene alkyl-aryl ether (as described
in Example I), then passing this size mixture through an orifice with a
continuous stream of water to yield an emulsion containing 2 parts of size
mix*ure in 98 parts of water. For retention purposes, 0.35% cationic starch
on
* Trademark
-22-
~ . . ..
` 10~3511
.
weight of dry fiber was added subsequent to the addition
of Emulsion B. Five pounds of alum per ton of stock were
added to ad~ust stock pH to approximately 5.5 when
Emulsion A and B were used. For further comparL~on, rosin
was al80 used as a sizing agent in these tests. Following
are the results obtained:
- ` TABLE 8
_ _ .__
Buildup Noted After Running 15 Min. Cobb
Smoothing Sizlng
Addition to Stock . 1st Press 2nd Press Pre~s (Gm/M )
l. Base Sheet - No AdditLves None None Slight 402
2, 1% Rosin + 2% Alum (.Control) Moderate Moderate Moderate 34
~ 3. 0.25% Emulsion A (Control~ Heavy Moderate Heavy 32
4. 0,25% Emulsion B None None Slight 29
The concentrations of the variou~ ingredients listed
in the above table sre expressed in terms of per cent active
lngredient by weight of dry pulp.
The above results clearly illu6trste the lmproved
machine operability and excellent wster holdout imparted by
the slze.mixtures of this invention when compared to
conventional 6izlng method~.employed in the industry.
EXA~lPLE IX
- This example lllustrates the excellent re~istance
to acidic and alkaline solutions which i8 di8played by the
paper whlch has been`prepared with our novel size mixture6.
An aqueous emulsion prepared with the s~sme slze
mixture and in the same manner u6ed to prepare Emulsion #~ in
- Example I was fldded to a bleached sulfate pulp slurry havlng
a freeness of .400 and a consistency 0.5%, The cstlonic ~tarch
of Example I wa9 then added to the stock as a retentlon aid
for the size. Sheets containing 0.4% ASA and 0.8% cationlc
starch were formed and condltioned as descrLbed in Example I.
- 23 -
` 1043511
The ~heets were tested by means of a modifLed potassium
permanganate test wherein 801utlon6 of 10% lactic acid ln
one case and 10% sod1um hydroxide in another case were used
as the test fluLd, along with distilled water as a control,
For a further comparieon, sheets were formed and tested in
the same manner wherein 1% rosin and 4% alum on dry fiber
welght was added to the stock for s1z~ng Ln place of our
sLæe mlxture. Followlng are the results obtained;
.
TAB~E 9
KMnO4 Penetration
Tlme tSeconds~
.
Sheet Distilled Lactic Sodlum
No. Additive Water - AcLd Hvdroxide
1 0.4~/~ ASA Mixture 111 95 65
2 1.0% RosLn/4% Alum 70 60 25
This example clearly shows the excellent resistnnce
imparted by these ~ize mixtures to penetration by both acidic
and alkaline flu~ds.
In summary, the invention is seen to provide the
practltioner with a novel size mixture useful in the manu-
facture of sLzed paper p~oducts~ The size mixture is easily
emulsified and the emulsion or size mlxture per se may be
utllized under a wide variety of papermaking conditions to
provide ~ized paper products characterized by their reduced
water and ink ab~orption as well as their ~ncreased resi~tance
to aqueous acid and alkaline solutions at low levels of
addition. Variations may be made in proportions, procedures
and materials without departln~ from the scope of this
invention,
'
r
- 24 -
