Note: Descriptions are shown in the official language in which they were submitted.
The present invenkion relates generally to sizing
agent emulsions and to a process for the sizing of paper.
More particularly, the present invention relates to novel
emulsifying agents for preparing emulsions of sizing agents
and fox use of the emul~ions in the sizing of paper and paper-
board products and to the improved paper prepar~d there~rom.
As used herein, the terms "paper~' and "paperboard"
refer to sheet-like materials and molded product~ made from
~ibrous cell~llosic materials and which may co~ain minor amounts
of synthetic fiber~ such as polyamide, polye~ter and polyacrylic
resin fibers, a~ well as mineral fibers such as asbestos and
glass .
It is well known to incorporate sizing materials into
paper and paperboard products for the purpose o~ increasing ~heir
resistance to penetration by liquids, particularly water. Un-
sized paper more readily absorbs liquids.
Rosin, variou~ hydrocarbon and natural waxes, ~tarchss,
~o~ium silicate, glues, casei}l, syIlthetic resin~, rubbQr ~atex,
~..~, .
fatty ketenes, and substituted cyclic dicarboxylic anhydrides
2 0 are among ~he ma~erials which have been used or have beel~ sug-
gested for use as sizing agents. The sizing agents may be added
direc:tly to the aqueous paper stock in a beater, or the formed
paper sheet may be run through a size solution or over a roll
we ted with a sizing agent. The process of siZing by ~he addition
of a si~ing agent to the paper fiber in a beater is referred to
as "~n~ernal sizing". The process of sizing wherein a iEormed
pa~e~ she2t is cont~cted with a sizing solution is referred to
as "external sizing". The siZing agent emul~ions o~ the present
invention are us~f~l in both internal sizing and external sizing
-. 30 proce~ses.
Ma~y of th~ sizing agents here~ofore used, have been
diff~cult to emulsify and require large capikal inve~tment cost
. ' ." ,, .
2 ~ ~ .
to provide equipment adequate to effect proper emulsification
of the sizing agent. Emulsification is desirable for sizing
agents so that the sizing agent is uniformly dispersed throughout
the furnish in an internal sizing operation. It is desirable
that the sizing agent be uniformly dispersed throughout th~
furnish in a~ small a par~icle size as is possible.
Accordingly, it is the principal object of the present
inventian to provide an emulsifyi~g agent for use with sizing
agen~s. It is another ob~ect o~ the present invention to
pxovide sizing agent emulsions whose use results in the preparation
of paper and paperboard products which are characterized by
i~creased re~istance to penetration by liquids, particularly
watex7 A further object o~ the present in~ention is to provide
emulsifying agents for use in prepari~g emulsions of sizing
agents which emulsions may be employed with all types of paper
pulp oYer the complete range of pH conditions wh~h are normally
encountered in paper manufacturing~ A still further ob~ect of
:- the present invention is to provide emulsifying agents which are
compatible with various sizing agents and with alum and with
various other components, such as fillers, pigments and other
chemicals which may ~e added to paper.
These and sther objects o the present invention will
become more apparent from the ~ollowin~ detailed description.
Generally, the emul~ifying agents of the invention for
use in preparing emulsions of sizing agents are sele~ted from
the gxoup consisting of trialkyl amines wherein:the alkyl
moiety is methyl or ethyl and ammonium hydroxide. Particularly :
preferrad amines for use as emulsifying agents are trimethyl ~:
amine~ trie~hyl amine and mixtures thereof.
The emulsifyi~g agents of the invention may be used
to form aqueous emulsions of sizin~ agents. Preferably the
aqueous emulsions herein are romprised of heterocyclic, organic
- 3 -
si2ing agents which have at least one long hydrocarbon chain
of about 8 to 30 c~rbon atoms attached thereto with the
heterocyclic s~ructure of said sizing agent containing an oxy
group bridging two carbon atoms wherein both the carbon atoms
which are attached to the oxy group contain a divalent bond,
i~e,, the group = ~ =. Suitable heterocyclic organic sizing
agents include maleated ~riglycerides, maleated alpha=rolefins,
maleated fatty acid ester~, alkyl ketene dimers, mixtures
thex~of and the like.
The emulsifying agents are pa~ticularly useful to
orm aque~us emulsions of sizing agents which comprise the
reaction product o~ maleic anhydride a~d an unsaturated tri-
~lyceride oil wherein the triglyceride oil has an iodine value
of at least ~bout 50. Thus, the triglyceride oil may be par-
tially hardened. By the term "triglyceride oil" is meant
the triester Q~ glycerol and the same or mixed fatty acids.
Fatty acids reer to straight chain monocarboxylic acids having
a carbon chain length of from C8 to C30.
5pecific examples of such preferred sizing agents
include the condensation reaction product o~ maleic anhydride
with soy bean oil, cottonseed oil, corn oil, safflower oil,
fish oil, linseed oil, peanut oil, oi~icica oil, dehydrated
castor oil, hempseed oil, and mixture thereo~. A particularly
preferred sizing agent is obtained from the reaction product
of maleic anhydride and soy bean oil. Various aspects of
~he present invention will be hereinafter described wi~h
particular reference to the preparation of aqueous emulsions
of the reaction product of maleic anhydride and soy bean oil.
~owever, it should be understood that the emulsi~ying agents
of he invention are suitable for pse with the reaction pro-
duct of maleic anhydxide with o~her triglyceridas oils and with
other organic heterocyclic sizing agents. : -
: ~. . , .. ,, , . :
Although the emulsion~ may be u~ed as an external
sizing agent ~e.g., applied ~o wet or dry formed paper webs~,
they are particularly useful as an internal sizing agent.
Internal sizing is best achieved by uniformly dispersing the
si~i~g agent throughout the fiber furnish. Disper~al of the
sizing agent throughout the furnish is prefercibly attain~d
by adding the sizing age~t as an emulsion.
In pr~paring emulsions of the sizing agent, the emul-
sifying agent is preferably first dispersed in the sizing agent
and the sizing agent is then added to the water with agitation.
The sizing agent is generally present in the emulsion at a level
of from about 1 to about 20 percent by weight. The trialkyl
amine emulsifying agent is used at a level of from about .5 to
a~out 2.5 percent, preferably from about 1 to about 2 percent,
by weight of the sizlng agent. The ammonium hydroxide is used
at a level of from about .05 to about 1 percent by weigh~ (on
, . .
an ammonia bas~s) by weight of ~he sizing agent. The ammonium :-
hydroxide is preferably used at a level of from about .1 to ~-
about .6 percent by weight of the ~izing agentO . ~ .
It is a surprising result of the use o~ the trialkyl
amine and ammonium hydroxide emulsifying agents of the invention,
that sizing agent emu}sions can be prepared with lessened amounts - ; .
and intensity of agitation. High shear agitation conditions are ~ :
not required. Stable emulsions can be formed using low shear
mixing co~ditioDs. As used herein ~he term l-low shear mixing
conditions" refers to the use of low shear mixing apparatus,
such as a pxopellor mixer, operated at moderate speeds of less .~ :
than about 1,500 x.p.m. This is a significant benefit of the
use of the emulsifying agents of the invention~ since sizing
agent emulsion can be prepared with simple equipment and high
capital costs are avoidedA
The sizing agent emulsions o~ the pre~ent invention
may be used in combination with a cativnic agent. Cationic
agents refer to materials which are capable of ionizing or
dis~ciating in such a manner as o produce one or more cations
or other positively charged moieties~ Suitable cationic agents
are alum, long chain fatty amines, sodium aluminate, aluminum
chloride, cationic s~arch derivative~, polyacryl ami<le, chromic
sulfate, and polyamide polymers. The cationic agent may be
added ~o the furnish prior ~o, at the same time a9, or after
the addition of the sizing aqent emulsio~. It is preferred that
the cationic agent be added either subsequent to ar in direct
combination with the sizing agent emulsion. However, the
addition to the paper stsck of ei~her the cationic agent or
the sizing agent emulsion may take place at any point in the
papermaking process prior to forming the wet pulp into a dry
sheet. ~ :
The sizing agent emulsions of the invention may be
used for sizing of paper prep~red from all type~ of cellulosic
pulps. The cellulosic pulps which are con~empl~ted or use
include bleached and unbleached sulfite pulps, bleached and un- ~;
bleached soda pulp5, bleached and unbleached sulfate pulp~
neutral sulfite pulp, semi-chemical pulp, chemi-ground~wood
pulp, ground wood pulp, a~d any combination of these pulps.
The cellulose pulp may contain minor amounts of synthetic fibers :~:
of the polyamide, polyester, polyacrylic, viscous rayon and ~ -
regenerated cellulose types~ : :
The sizing agen~ emulsions of the present inventio~
are compatible wi~h all types of pigments and fillers which
are normally used or added to the paper which is to be sized.
Such materials include titanium dioxide, ealcium carbonate9
clay, ~alc, calcium culfa~ei diatomaceous earths and the ca~
ionic agents previou~ly described.
: - 6 -
The sizing agent emulsions of the invention are used
at levels sufficient to provide from abo~t ~1 to about 5 parts
by weight o~ the sizing agent per 100 p~rts by weight of the
cellulose pulp, dry solids basis . Pref~rably, from about O . 5
to about 1. 5 parts by weight of the sizing agent pt-r 100 parts
by weight of pulp are used. The amount of sizing agent to ,be
used depends upon the type of pulp which is being sized and
the specific properties desired in the finished paper or paper
product. Paper which requires yood water resistance or ink
10 resistance requires the use of higher concentrations of sizing
agent than does paper which is used where relatively low water
resistance or ink resi~tance is required. In general, from
about 1 to about 15 parts by weight of a cati~nic agent are
used per S parts by weight of sizing agent.
In prepari~g maleic anhydride reaction product siæing :~
agent~, the txiylyceride oil, wh~ch may be partially hardened
but which ha~ an iodine value of more ~han 50, is first heated
to a temperature in the range of from about ~00F to about ~50F.
Thereafter, the maleic anhydride is added to ~he triglyceride -~.
2a oil while the triglyceride oil is ~eing agitated to efect a ::
condensation reaction~ ~he maleic anhydride is maintained in
contact with ~he triglyceride oil at the elevated temperature
for a time of from about 2U minutes to about 40 minutes as the
triglyceride oil is bei~g agitated. Thereafter, the reaction
mixture is pe~mitted to cool ~o ambisnt temperature to provide
the s~zing agent. Oxygen and water should be excluded from the
reactio~ mixture during ~he reaction. For this reason, it is
preerred to blanket the surface of the triglyceride oil with
: an inert gas during the reactio~ or to conduct the reaction in
3Q a vacuumO
In gen~ral9 the maleic anhydride is added to the tri~
glycPride ~il at a levPl o~ from about 0.9 to about 2 mols per
- - - . . . - . - . - - - , . . -
- . . . - , . . , , ~ . .. . .-
mol o~ triglycPride oil. At levels of addition of maleic anhy-
dride less than the above range the resultant reackion mixture
is less effective for use as a sizing agent. Higher levels of
addition of maleic anhydride than the above identified range can
be u~ed but there is no advantage to the use of such higher level~
and the resultant cost of the sizing agent is increased.
The ef~iciency o the maleated oil siæing agents is
directly related to the retention of the maleic anhydride
moieties in the non-hydrolyzed form. For this reason, it is ::
preferred that emulsions of the sizing agent have a pH of between
about 5 to about 8.5. At higher or lower pH, the maleic anhy-
dride moieties ~end to hydrolyze.
. The following example further illustrates various
features of the presen~ invention, but is intended to in no way
limit the scope of the invention wh~ch is defined in the appended
claims.
EXAMPLE I
A sizing agent emulsio~ in accoxdance with the present - :
invention ? S prepared, and is used to effect sizing of a paper
product. The siæing agent emulsion is used i~ combination with
alum as a cationic agen~ and the water resistance of paper re- :
sulting from the use of the sizing agent is determined.
- 880 kgs of pure soy bean oil having an iodine value
- of about 125 is charged into a covered reactor. The head ~pace
in the reactor is blanketed with nitrogenO The soy bean oil i~
heated to a temperature of 430~F. Thereafter~ maleic anhydride
is dded to the soy bean oil in th% reactor as the soy bean oil
is being agitated. The maleic anhydride is added at a level of
1~25 mols of maleic an~ydride p~r mol of soy bean oil~ The
reaction mixture after the last addition of maleic anhydride
is maint~ined at a temperature of 430F for 30 minutes. There-
after, the reaction mixture is allowed to covl to provide a
maleated oil sizing agent.
EXAMPLE II
Various paper samples, as set forth in Table I below
were prepar~d using a sizing agent emulsion prepared with the
emulsifying agents of ~he invention. In each sample, except one,
the emulsi~ying agent is added to a maleated soy bean oil sizing
agent prepared in accordance with the foregoing. In the case of
sample 8? ~he sizing agent consistad of maleated linseed oil pre-
pared in accordance with the foregoing procedure for preparing
maleated soy bean oil~ In examples 1-7~ the sizing agent is
malea~ed soy bean oil having a molar ratio of maleic anhydride
to soy bean oil as set forth bel~w in Table I. Fox each sample,
an emulsifying agent of the invelltion is added to the maleated
oil sizing agent. The sizing agent containing the emulsifying
agent is then added to water as the water is a~itated by a pro-
peller mixer to provide an aqueous emulsion of the sizing agent.
The sizing agent is added to the water at a level sufficient to
provide an emulsion having 5 percent by weight of the sizing :
agentl .,
The aqueous emulsion of th~ sizing ag~nt is then added
to a furnish of bleached sulfit~ pulp having a pH of about 6 . 5 . . .
Alum and a quaternary amine starch derivative are previ~usly
added to ~he pulp. For all of the samples, except sample 1,
the alum and the quaternary amine starch deriva~ive are each
present in the furnish at a ratio on a weight basis to the
si2ing agent of 1:1. In sample 1, alum is present at a ratio
of 1.5:1 and the quaternary amine starch is present at a ratio ;:
of 1:1. The sizing agent is added o the furnish at a level
sufficient to provide .5 percent by wei~ht of the sizing agent
in the furnish based on ~he dry weight of the pulp.
~ Hand sheets are formed and dried in accordance with
TAPPI standards. The water resistance of the hand sheets is .
determined by the KBB test. In this test, the dried hand sheet :~
is placed on an imperfora~e platen having an electrical lead
connected thereto. A second porous pla~en, also having an
electrical lead connectea thereto, is saturated with moisture
and placed in contact with the hand sh~et on the first platenO
The time required to establish a current of 80 milliamps betwe~n
the second platen and the first platen is measured. This time
period in seconds is a mea~uxe o the ef~ective~ess of the sizing
of the paper; tha~ is, the longer the time required to establish
an 80 milliamp current, the better ~h~ water x~sistivity o~ the
paper. :
The oll~wing Table I sets foxth data on the various
hand sheets in respect to the ratio of maleic anhydride to tri-
glyceride oil, the emulsifying agent used, the level of the emul- :
sifying agent and ~he filler used, if any. In each case where
a filler is us~d, the clay ~iller is used at a level of 10 percent
by weight of th~ fiber, dry basis, and titanium dioxid~ is used
at a le~el of S percent by weiqht of ~he fiber, dry ba~is.
TABLE I
Le~el of
emulsify-
Ratio o~ ing agent
maleic - percent
: anhydride by weight
: to tri- based on KBB t~st value - seconds
: glyc~ride the weight 1 day
- S~mple oil (mols~ Emulsify- of ~he siz- Filler i~mediately after
No. mol) ing agen~ ng agent ty~ af~er drying dryin~
1 1.25 NH40H .33 Clay 50 45
(as NH3) and
2 1.25 NH40~ .08 None 32 35
( 3
3 1025Tri~ethyl- 055 None 53 57
1.25 " 1.0 None 58 56
1,25Triethyl- 1.0 Clay 66 61
amine
6 0~5 " 1.0 Cl~y 13 30 :.
7 1.5 " 1.75 Clay 3~ 39
8 1.25 " 1~0 Clay 44 50
-- 10 ~
EX~LE III
190 ml. o:E 110F tap water, 10.0 g. of alkenyl ~uc:cinic
anhydride and Q.3 g. of trie~lyl amine were added to a house-
hold-type blender. An emulsion was fo~med by op~rating the
blender for 1 minute. In a simular manner an amulsion of alkyl
ketene dimer was prepared. Both of ~he aqueous emulsions were
stable and were used to prepare hand sheets.
EX~MPLE IV
A sizing agent emulsion was prepared using a laboratory
wat~r aspirator attached to a water line provided with water at
60 psig pressure. A water flow rate of 18,000 ml./minO was
maintained through the aspira~or~ A malea~ed soy bean oil pre- -
pared in accordance with Example I was fed throu~h the side arm
of the aspirator. The maleated soy bean oil contained 1~75 per-
cent trie~hyl amine dissolved ~h~rein, A stable emulsion of
the maleated soy bean oil was provided by the mixing action
attained by ~eeding the maleated soy ~ean oil through the side
arm of the aspirator into the stream of water flo~ing through
the aspirator. Sufficient maleated soy bean oil was fed to the
2Q side arm of th~ aspirator to provide an aqueous emulsion having ~ ;
1.5 percent by w~ight of maleated so~ bean oil.
The resultan emulsion was uniformly dispersed in a
paper fur~ish containing paper maker`'s alum and cationic starch
in accordance wi~h the method described in Example II. Hand
sheets were made with the emulsion used as an internal sizing
ag~nt. -~ :
The level of sizing agent used, level of alum uxed,
cationic starch level, KBB sizing value ~or the hand sh~ets
produced in accordance with Examples III and IV get forth belo~ :~
in Table II.
TABLE I I
Cationic
Handsheets Sizing Agent A.lum Starch XBB
made by ~/ton (dry #/ton #/ton Sizing-
Example basis~ (dry basis~ (dry basis) ~ Sec.
III lo~O 10 10 6.5 91
IV 8.8 10 lû 6.5 72
The amulsifying agents of the present inven~ion are
highly effective to provide emul~ions of sizing agents, particular-
ly malea~ed oil size agents, by simple low shear mixing. The
emulsifying agent of the invention provides ~he paper manufac~urer
with an easy and effective means, requiring little capital cost,
to prepar~ sizlng ag~nt emulsions and to utilize the sizing agent
emulsions in the sizing of paper.
- 12 -
