Note: Descriptions are shown in the official language in which they were submitted.
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SYNTHETIC CATIONIC POLYMERS
AS PROMOTERS FQR ASA SIZING
Technical Field
This invention relates to emulsions using synthetic cationic polymers as promoters
for alkenyl succinic anhydride sizing, and more specifically to an emulsion containing
alkenyl succinic anhydride and a synthetic cationic polymer that enhances sizing efficiency
and a method of using the same.
R~:kground of the Invention
Sizing agents in the papermaking process are used to promote reduced water and
ink absorption in the paper product as well as to resist P~queous acid and alkaline solutions.
AS used herein, the temm "papef is conle",plated to include any sheet-like masses and
molded products made from fibrous cellulosic materials which may be derived from both
natural and synthetic sources.
Paper is often sized with various materials to increase resistance to water as well
as to other types of aqueous solutions. These materials are referred to as sizes or sizing
and they may be introduced during the actual papemmaking process. Alternatively, the sizes
or sizing may be applied to the surface of the finished web or sheet.
One example of a sizing agent is alkenyl succinic anhydride ("ASA"). ASA, usefulin the sizing of cellulose materials, has gained considerable commercial success in
papermaking, particularly as an alternative to the conventional rosin-alum sizing system.
The use of ASA as a sizing agent is well known in the art, as described in Farley and
Wasser, "Sizing with Alkenyl Succinic Anhydride" in The Sizing of Paper, W.F. Reynolds,
Ed., TAPPI, 1989, Chapter 3. See also U.S. Patent No. 3,968,005, which is incorporated
herein by reference.
ASAis water insoluble and hydrolytically unstable. Therefore, it must be emulsified
at the paper mill prior to use. Specifically, the art requires that for retention the sizing
agents be used in conjunction with a material that is cationic in nature, or is capable of
producing one or more cations or other positively charged groups. Emulsification is
normally achieved by passing the ASA and a protective colloid, starch and/or synthetic
polymer, through a device such as a homogenizer, high shear turbine pump, etc.
Cationic starch plays several important roles in ASA sizing. First, it aids in the
generation of small particle size ASA emulsions. Small particle size, in the micron range,
is required for good sizing efficiency. Second, it imparts good physical stability to the
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emulsion. ASA emulsions must be stable in order to prevent deposits and press picking
once they have been added to the paper fumish. Third, it retains the emulsion on the fiber
surfaces and promotes sizing efficiency. Sizing levels for a given amount ofASA are found
to increase several-fold as the amount of cationic starch in the pulp fumish increases.
Normally, cationic starch is used at a ratio of 2 to 4 times that of the ASA to give optimum
sizing efficiency.
Certain problems arise with the use of cationic starch, however. For example, the
starch must be cooked at the mill, thus requiring large scale cooking equipment and storage
tanks. More importantly, starch is susce,clillc to biological dey~dalion, resulting in slime
growth and the creation of deposits on paper mill equipment, causing runnability pl.~ble",s
in the fomm of press picking, felt filling and poor cylinder vat consislency control.
It may be desirable, in some cases, to make the ASA sizing system function
independently of cationic starch. The variation in batch-to-batch starch viscosity and solids,
and the need to cool the starch before emulsification can lead to unwanted variation in ASA
emulsion particle size. Some paper mills do not like to use starch because of the difficult
cooking and handling requirements. Others, where fine paper grades are made and where
much of the ASA sizes are currently being used, require cationic starch for dry strength, but
the mills would prefer to use lower cost cationic com starches. Generally, more expensive
cationic potato starch gives better results for ASA sizing.
Synthetic polymers as altematives to cationic starch for ASA emulsification, andspecitically to overcoming the problems associated with cationic starch, have been studied.
The synthetic cationic polymers of the art as altemative to starch are not reactive with ASA.
For example, U.S. Patent No. 4,657,946 teaches an improved emulsification of ASA sizing
agent by using cationically charged water soluble vinyl addition polymers. The '946 patent
teaches a paper sizing method and emulsion using cationically charged, water soluble, vinyl
addition polymers and condensation polymers that provide improved emulsification of
alkenyl succinic anhydride sizing agents. U.S. Patent No. 5,224,993 teaches a saponified
sizing agent for paper derived from the dehydration condensation of an alkenyl succinic
anhydfide and an organic carboxylic acid with a polyalkylene polyamine and the
saponification of the remaining carboxyl groups with alkali following the dehydration
condensation. U.S. Patent No. 4,629,655 teaches a size composition as a solid product
produced by mixing a cation!c polymer suitable for functioning as a size retention aid and
a size suitable for sizing a substrate. The process for sizing a substrate in the '655 patent
comprises dispersing the solid in an aqueous mixture, applying the resultant mixture to a
substrate, and causing the size to be fixed to the substrate thereby. However, the synthetic
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~ 7 ~
1 7 ~~
cationic polymers of the art have only been marginally successful as a suitable replacement
for starch. None of these synthetic cationic polymers contain functional groups that are
reactive with ASA. The synthetic cationic polymers of the art which serve as additives and
co-emulsifying agents for ASA sizing do not enhance sizing (or do not serve as good
5 promoters).
Various patents disclosing polymers that are reactive with ASA do not teach the use
for promoting the efficiency of sizing agent. For example, these patents include U.S. Patent
No. 5,232,553, which teaches a papermaking process using polyvinylaminals in which the
paper product obtained from the pulp slurry contains fine particles of material. The '553
10 patent relates to the use of poly(vinylamine) and aldehyde for increasing the retention of the
fines in the paper product.
In developing an altemative to starch in the ASA emulsions, it is generaily found that
producing a synthetic cationic polymer having high viscosity to generate small particles size
emulsions and acting as a retention aid is not particularly difficult. The difficulty lies in
15 developing a synthetic cationic polymer that promotes the sizing efficiency of ASA by
providing ASA reactive groups that can anchor the ASA to the fiber surface.
Various other patents make use of similar synthetic cationic polymers but do notteach an increase in sizing efficiency in papermaking. An anhydrous dispersion of a
polyelectrolyte in a liquid reactive size is claimed in EP-A-0 200 504. U.S. Patent No.
4,217,214 teaches the use of high molecular weight polyvinylamine hydrochloride for the
flocculation of suspended solids in water purification or waste water clarification systems.
U.S. Patent Nos. 4,957,977 and 5,281,307 teach a paper strength increasing agent using
a vinylamine copolymer. U.K. Patent Application GB 2,268,758A teaches a paper wet
strength improvement by wet- or dry-end addition of an amine-functional poly(vinyl alcohol)
and a cellulose reactive size which is a 4 or 5 membered cyclic ester or anhydride having
one or more alkyl or alkenyl substituents of 4 or more carbon atoms and having a total of
at least 8 carbon atoms in the substituents. In fact, patents that are directed to synthetic
cationic polymers in the art do not specifically relate to increasing the efficiency of paper
sizing.
While the synthetic agents of the art have met with some success, there has beena need in the paper industry to produce a more effective cationic agent that is useful as a
promoter for sizing to avoid the problems generally associated with cationic starch. Such
a cationic agent would be reactive with ASA and would significantly enhance sizing
efficiency.
AMEt~iDED SHE~
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~ummary of the Invention
According to the present invention, there is provided methods in papemmaking forimproving the sizing efficiency of a hydrophobic, cellulose sizing material which co~ uri~es
adding thereto a synthetic cationic polymer that is reactive with said sizing material. Groups
that are reactive with ASA include primary amine and hydroxyl. The pr~t~rr~d sizing
material is alkenyl succinic anhydride. The preferred synthetic cationic polymer comprises
a copolymer of primary amine. Also provided is a synthetic cationic polymer which co, l - IS
one or more non-sizing reactive monomers, particularly, non-ASA reactive monomers, like
acrylic acid. For the purpose of this invention, the term non-sizing reactive monomer (or
non-ASA reactive monomer) refers to a monomer that does not result in a significant
reaction with a sizing material. The synthetic cationic polymer may be a copolymer of vinyl
alcohol and vinylamine. The synthetic cationic polymer may also be a copolymer of
acrylamide and vinylamine.
There is also provided a method in papemmaking for improving the sizing efficiency
of a hydrophobic, cellulose sizing material which comprises adding to a cellulose sizing
agent an effective amount of a synthetic cationic polymer containing hydroxyl and/or primary
amine groups. Preferably the polymer comprises about 50 to about 99 mole % vinylalcohol
and about 50 to about 1 mole % vinylamine.
There is provided a method in papemmaking for improving the sizing efficiency of an
alkenyl succinic anhydride comprising adding thereto a synthetic cationic polymer of about
20 to about 90 mole % acrylamide and about 80 to about 10 mole % vinylamine.
This invention discloses an alkaline sizing emulsion for improving the sizing
efficiency in papermaking COI I ~pris;l ,9 a hydrophobic cellulose sizing material and a
copolymer of cationic vinylamine that is reactive with said sizing material. Preferably, the
sizing material is alkenyl succinic anhydride. It is preferable to have as a copolymer
co"~p,isi"g a synthetic polymer of about 20 to about 90 mole % acrylamide and about 80
to about 10 mole % vinylamine. It is also preferable to have as a copolymer comprising a
synthetic polymer of about 50 to about 99 mole % vinylalcohol and about 50 to about 1
mole % vinylamine.
There is also provided an alkaline sizing emulsion comprising an alkenyl succinic
anhydride sizing material and an effective amount of a synthetic cationic polymer reactive
with the sizing material wherein the polymer contains hydroxyl and/or primary amine groups.
As provided herein, the term "effective amount" is defined as the quantity of material
needed to increase the sizing efficiency of a sizing agent.
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Det~iled Description of the Preferred Embodiments
Various synthetic cationic polymers were evaluated as replacements for cationic
starch that is nommally used in the ASA paper sizing process. Cationic starch has been
shown to be a good sizing promoter for ASA.
To del"on~lldLe the effect of various synthetic cationic polymers on ASA sizing
promotion performance based on an increase in sizing efficiency using cationic starch were
evaluated in comparison with a variety of different synthetic cationic polymers. It should be
noted that starch is distinct from the synthetic cationic polymers because starch is a natural
substance rather than synthetic.
Paper handsheets containing the size and promoter were prepared and used for
sizing evaluation. For the purpose of this invention a handsheet is col"p~ised of pulp
fillers, sizing agent (ASA) and promoter (a cationic starch or a synthetic cationic polymer).
Emulsification of ASA usin~ cationic polyacrylamide:
For each handsheet evaluation an ASA emulsion is prepared in deioni~ed water.
The emulsification procedure proceeds as follows: 24.0 9 of deionized water was weighed
into a small (about 35 mL capacity) stainless steel blender jar. About 1 9 of ASA (~:~;9l ,ed
by difference) is added and the blender is run at high speed for five minutes. Based on the
c. ~ ted ASA conce~L~lion the sample was immediately diluted to 0.25% with cold pH
3 deionized water to rllilli~ e hydrolysis. The sample was kept on ice until used for the
handsheet evaluation. Particle size was estimated to be in the 1.5 to 2 micron range.
A variety of synthetic cationic polymers containing copolymers of amide and amine
groups as well as alcohol and amine groups are within the scope of the invention. Each
of the polymers and copolymers was selected for evaluation because each containsfunctional groups (i.e. primary amine or hydroxyl) that can react with ASA.
Cationic polyvinylalcohol may contain 6 mole % vinylamine groups (PVOH/PVA) and
have a molecular weight in the range of from 80 to 140 k daltons. The copolymer was
prepared by hydrolysis of a copolymer of vinylacetate and N-vinyl fommamide.
Polyvinylamine (PVA) and polyvinylamine.HCI (PVA/HCI) are co"l~"~plaled as useful
in this invention. The PVA is of a low molecular weight and is supplied as a 12.8% solution.
The PVA.HCI may be a medium molecular weight powder.
Polyallylamine.HCI (PAA) and copolymer of allylamine and diallylamine.HCI
(PAA/PDAA) are also contemplated as being useful in this invention. The PAA has an
average molecular weight of about 100 k daltons and is supplied as a 40% aqueoussolution. The PAA/PDAA has a weight average molecular weight of 50 k daltons.
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The Hofmann degradation of polyacrylamide using sodium hypochlorite introduces
primary amine and carboxyl groups. Samples were prepared colllail ,i"g about 40 mole %
primary amine using polyacrylamide samples of four different molecular weights ranging
from 14 to 200 k daltons using the procedure from Tanaka (see, H. Tanaka, J. Polymer
Science: Polymer Letters Edition 16, 87-89 (1978)).
Table I presents the Hofmann degradation products of polyacrylamide. In analyzing
the amine and carboxyl contents of the Hofmann degradation products, it is shown that the
variation in molecular weights does not significantly change the concenLrdlion of amine
content, carboxyl content or isoelectric pH.
Table I
Molecular mole % mole %
FY~mple weight amine c~rboxyl Isoelectric pH
(k daltons)
1 200 40 14 9
2 77 47 24 9
3 47 60 24 8
4 14 47 14 8.5
In addition to ASA-reactive synthetic cationic polymers, various non ASA- reactive
synthetic cationic polymers were conside,~d as plumoLe,~, for example,
acrylamide/methacryloxyethyltnmethyl ammonium chloride (acrylamide/Q6) copolymer,
polyethylenimine (polymer with average molecular weight of 50 to 60 k daltons, containing
mostly secondary amine groups), Mannich quatemary of polyacrylamide, and terpolymers
of acrylamide, acryloxyethyltrimethylammonium chloride (Q9) and alkyl methacrylate.
The ASA primarily used is ACCOSIZE~ 18 (available from Cytec Industries Inc.).
Promotion of ASA .~i7ing:
The sizing level achievable with ASA significantly increases (is promoted) as the
amount of cationic starch in the system increases. The magnitude of the increase and that
sizing continues to increase even with relatively large amount of cationic starch, up to 3:1
ratio of starch to ASA. Because of this effect, a high ratio of cationic starch to ASA is used
in current commercial practice. It does not matter whether the cationic starch is part of the
ASA emulsion or whether it is added separately to the furnish. As shown in this invention,
the sizing level of an ASA sizing agent may also be significantly increased by increasing
the concentration of synthetic cationic polymers that are reactive with ASA.
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H~ndsheet ev~ tion of polymers as ASA promoters
The handsheet experiments are done usir~g the following procedure. The fumish
is a 50t50 mixture of bleached hardwood and softwood kraft pulps beaten to a Canadian
Standard Freeness of ~00 to which 15% by weight of pr~c;~.ilal~d calcium carbonate is
added and the pH adjusted to 7.5. While stirring, a batch of 0.6% cons;slency stock
containing 109 of fiber is treated with the promoter, followed by a given dosage of ASA
emulsion, then with 1.0 Ib/ton of anionic polyacrylamide retention aid. Fifteen seconds of
contact time is allowed between each addition. Three-2.8 9 handsheets (50 Ib/Tappi ream)
are fommed, pressed with 1-1/2 weights, and dried one minute on the rotary drum drier at
1 0 240~F.
Basis weight and sizing are measured on the sheets after conditioning for at least
24 hours at 23 ~C and 50% R.H. The handsheets are tested for ink penetration using a
sizing test of the type described in Tappi Standard T-530 pm-83. It measures the elapsed
time after contacting one side of the paper with ink for the reflectance of the opposite side
to fall to 80% of its initial value. The ink is the same as described in T-530 pm-83, but
contains no formic acid and is buffered to pH 7. The tests are nomlalized to 50 Ib/Tappi
ream basis weight assuming sizing is prupo,lional to the cube of the basis weight.
While it is apparent that the invention herein disclosed is well cr'c~ ed to describe
the invention stated above, it should well be appreciated that numerous modifications and
embodiments may be devised by those skilled in the art, and it is intended that the
appended claims cover all such modifications and embodiments as fall within the true spirit
and scope of the present invention.
EXAMPLES 5 TO 14 (Comparative)
Example 5 of Table ll shows the results of an evaluation of the ink penetration of
an ASA emulsion made with a 90/10 mole ratio AMD/Q6 copolymer. This same emulsion
was then post-diluted with either additional AMD/Q6 copolymer (a synthetic cationic
polymer) or with cationic starch. The ASA dosage was 0.15% on fiber in all the examples.
Post-dilution with additional AMD/Q6 copolymer (Examples 6 to 9) shows that the sizing
efficiency does not increase appreciably, since the copolymer is not reactive with ASA.
Examples 10 to 14 show that the AMD/Q6 copolymer post-diluted with cationic starch
provided marked increase in sizing efficiency. As used herein, ink penetration is provided
for in seconds. It is shown that the effect of the increase in sizing efficiency is attributed
to the cationic starch (which is ASA-reactive) and not to the AMD/Q6 copolymer (which is
not ASA-reactive).
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Table ll
Post Dilution with Post Dilution with
Ex~rnple C~tionic Polymer C~tionic St~rch Ink Penetration
(Ratio to ASA) (Ratio to ASA) (sec)
5 (initial emulsion) 0.13 - 70
6 0.5 - 138
7 1.0 - 117
8 2.0 - 64
9 3.0 - 86
- 0.5 187
11 - 1.0 254
12 - 2.0 329
13 - 3.0 349
14 - 4.0 396
EXAMPLES 15 TO 23 (Comparative)
Table lll p,~se~ results of an evaluation that is similar to that presented in Table
Il. The 90/10 mole ratio AMD/Q6 copolymer of these examples is made by inverse
20 emulsion techniques. Example 15 shows the sizing obtained with ASA emulsion made
using the AMD/Q6 copolymer. The ASA dosage is 0.15% on fiber in all the exa",pl~s. This
same emulsion is then post diluted with either additional AMD/Q6 copolymer (Exanlp cs 16
to 18) or with cationic starch (Examples 19 to 23). These examples (Exdlllp Es 15 to 18)
show that the addition of inverse emulsion AMD/Q6 copolymer does not increase sizing
25 efficiency since the copolymer is not reactive with ASA. Examples 19 to 23 show that the
inverse AMD/Q6 copolymer diluted with cationic starch provided marked increase in sizing
efficiency. It is shown that the effect of the increase in sizing efficiency is attributed to the
cationic starch (which is ASA-reactive) and not to the AMD/Q6 copolymer (which is not
ASA-reactive).
Table lll
Post Dilution with Post Dilution with
F~rnple C~tionic Polymer Cationic St~rch Ink Penel,~lion
(Ratio to ASA) (Ratio to ASA) (sec)
15(initial emulsion) 0.13 - 62
16 0.5 - 78
17 1.0 ~ 35
18 2.0 - 11
19 - 0.5 130
- 1.0 189
21 - 2.0 257
22 - 3.0 290
23 - 4.0 340
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EXAMPLES 24 TO 32 (Comparative)
Table IV shows the results of an evaluation that is similar to those presented in
Tables ll and lll. In this case, the synthetic cationic copolymeris 99/1 mole ratio AMD/Q9.
An ASA emulsion is prepared using water only, Example 24. The ASA dosage was 0.125%
5 on fiber in all of the examples. This same emulsion is then post diluted with either AMD/Q9
copolymer (Examples 25 to 27) or with cationic starch (Examples 28 to 32). These
examples demonstrate that the addition of AMD/Q9 copolymer does not increase sizing
efficiency since the copolymer is not reactive with ASA. Post dilution with cationic starch
provides a marked increase in sizing efliciency. It is shown that the effect of the increase
10 in sizing efficiency is attributed to the cationic starch (which is ASA-reactive) and not to the
AMD/Q9 copolymer (which is not ASA-reactive).
Table IV
Post Dilution with Post Dilution with
FY~rnple Cationic Polymer Cationic Starch Ink Penetration
(Ratio to ASA) (Ratio to ASA) (sec)
24 (initial emulsion) - - 6
0.5 - 8
26 1.0 - 4
27 2.0 - 5
28
29 - 0.6 77
- 1.2 89
31 - 2.4 157
32 - 4.8 179
EXAMPLES 33 TO 41 (Comparative)
Table V shows that the results of an evaluation of sizing as a function of promoter
dosage for various promoters. Each of the examples in Table V is conducted using 0.2%
on fiber of ASA. Examples 33 to 35 use a 18/20/2 mole percent terpolymer of
acrylamide/Q9/n-dodecylmethacrylate terpolymer. This is a non-ASA reactive polymer.
Examples 36 to 38 use cationic potato starch as the promoter. Examples 39 to 41 use
PVOH/PVA as the promoter. Ink penetration is provided for in seconds. These examples
show that the promotion effect of PVOH/PVA, an ASA-reactive polymer, increases the
sizing efficiency by increase in dosage.
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Table V
Dosage of
E~rnple C~tionic Polymer Ink Penetration
(% on fiber) (sec)
33 0.05 2
34 0.10 2
0.20 2
36 0.05 10
37 0.10 5
38 0.20 58
39 0.05 44
0.10 48
41 0.20 195
EXAMPLES 42 TO 49 (Comparative)
Table Vl presents the results of an evaluation of the sizing as a function of promoter
dosage for various promoters. Each of the exdr~'-s in Table Vl are conducted using
0.15% on fiber. Examples 4Z to 45 use cationic potato starch as the promoter. Examples
46 to 49 use PVOH/PVA as the promoter. Other parameters of this analysis are similar to
those of Table V (Examples 33 to 41). Table Vl demon~lldtes that PVOH/PVA is a more
effective promoter than cationic potato starch (over the range of 0.075 to 0.45 Ib/ton).
These examples show that the promoter efficiency is a function of promoter concentration.
Here, the PVOH/PVA is a much more effective promoter than cationic potato starch when
the cationic polymer (either the synthetic cationic polymer or the starch) concentration is
less than about 0.45% on fiber.
Table Vl
Dosage of
FY~rnple ~tionic Polymer Ink Penetration
(% on Fiber) (sec)
42 0.075 160
43 0.15 157
44 0.30 194
0.45 222
46 0.075 251
47 0.15 269
48 0.30 315
49 0.45 214
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EXAMPLES 50 TO 55 (Comparative)
Table Vll presents the results of an evaluation of sizing as a function of p~u~ult:r
dosage for various promoters, as in Table V (Examples 3~ to 41). The emulsions of Table
Vll are prepared in the presence of either the PVOH/PVA or the cationic potato starch at
5 0.5/1 ratio to ASA. After emulsification, additional PVOH/PVA or cationic potato starch is
added to the furnish to give dosages of 0.075, 0.15 or 0.3% on fiber. Examples 50 to 52
use cationic potato starch as the promoter. Examples 53 to 55 use PVOHtPVA, an ASA-
reactive polymer, as the promoter. These examples clell~onsll~le that the pru""~ter
efficiency is a function of the sizing concentration and the reactivity of the promoter with the
sizing material.
Table Vll
Dosage of
FY~rnple ~ tionic Polymer Ink Penetration
(% on Fiber) (sec)
0.075 140
51 0.15 232
52 0.30 171
53 0.075 208
54 0.15 254
0.30 314
EXAMPLES 56 TO 70 (Comparative)
Table Vlll shows the results of an evaluation of sizing as a function of promoter
dosage for various promoters, as in Table Vl (Examples 42 to 49). Examples 56 to 59 use
polyethylenimine as the promoter. Example 60 to 63 use a Hofmann degradation product
as the promoter (Table 1, Example 1). Exdmp'~s 64 to 66 use cationic potato starch as the
promoter. Ex~lllp'~s 67 to 70 use PVOH/PVA as the promoter. These examples show that
ASA-reactive synthetic cationic polymers (both PVOH/PVA and the Hofmann degradation
product) provide promoting effect to ASA sizing. The polyethylenimine, which is not ASA-
reactive, does not.
-
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Table Vl l l
Dosage of
Ex~mple C~tionic Polymer Ink Penetration
(% on fiber) (sec)
56 0.075 2
57 0.15 4
58 0.30 2
59 0.45 2
0.075 28
61 0.15 92
62 0.30 242
63 0.45 184
64 0.075 111
0.15 144
66 0.45 282
67 0.075 225
68 0.15 285
69 0.30 434
0.45 350
EXAMPLES 71 TO 82 (Comparative)
Table IX shows the results of an evaluation of sizing as a function of promoter
dosage for various promoters, as in Table Vl (ExdlllF'Es 42 to 49). The dosage of ASA is
0.2% on dry fiber. Examples 71 to 73 use a Mannich quatemary of polyacrylamide as the
promoter. Examples 74 to 76 use cationic potato starch as the promoter. Examples 77 to
79 use PVOH/PVA as the promoter. Exdlllp'Es 80 to 82 use a Hofmann degradation
product as the promoter (Table 1, Example 1). This experiment shows that the two ASA-
reactive synthetic cationic polymers (PVOH/PVA and the Hofmann degradation product)
provide promoting effect to sizing. The Mannich quatemary of polyacrylamide, which is not
ASA-reactive, does not.
,
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Table IX
Dosage of
FY~mple C~tionic Polymer Ink Penetration
(% on fiber) (sec)
7t 0.075 2
72 0.15 2
73 0.3~ 2
74 0.15 7
0.30 24
76 0.45 101
77 0.0375 40
78 0.075 45
79 0.15 129
0.075 73
81 0.15 72
82 0.30 177
EXAMPLES 83 TO 106 (Comparative)
Table X shows the results of an evaluation of sizing as a function of promoter
dosage for various promoters as in Table Vl (Examples 42 to 49). 0.15% ASA on fiber
is used. Examples 83 to 85 use PAA/PDAA of 50 k daltons molecular weight as the
promoter. Examples 86 to 88 use PAA of 100 k daltons molecular weight as the promoter.
Examples 89 to 91 use a Hofmann degradation product of 14 k daltons molecular weight
(Table 1 Example 4) as the promoter. Examples 92 to 94 use a Hofmann degradationproduct of 47 k daltons molecular weight (Table 1 Example 3) as the promoter. EXdmp'~s
95 to 97 use a Hofmann degradation product of 77 k daltons molecular weight (Table 1
Example 2) as the promoter. Examples 98 to 100 use a Hofmann degradation product of
200 k daltons molecular weight (Table 1 Example 1) as the promoter. Examples 101 to 103
use cationic potato starch as the promoter. Examples 104 to 106 use PVOH/PVA as the
pru",~ter. These examples show that the promoting effect of the Hofmann degradation
products increases with increasing molecular weight. Also these examples show that the
promoting effect of the Hofmann degradation products increases with increasing amount of
the p~u",oler with the sizing material.
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Table X
Dosage of
FY~n1PIe C~tionic Polymer Ink Penetr~tion
(% on fiber) (sec)
83 0.075 11
84 0.15 40
0.30 29
86 0.075 2
87 0.15
88 0.30 3
89 0.075 2
0.15
91 0.30 7
92 0.075 2
93 0.15 2
94 0.30 2
0.075 15
96 0.15 20
97 0.30 111
98 0.075 71
99 0.1~ 194
100 0.30 236
101 0.15 236
102 0.30 312
103 0.45 373
104 0.075 308
105 0.15 491
106 0.30 389
EXAMPLES 107 TO 130 (Comparative)
Table Xl shows the comparative results of an evaluation of the ink penetration as
a function of promoter dosage for various promoters, as in Table X (Examples 83 to 106).
Examples 107 to 109 use a Hofmann degradation product of 14 k daltons molecular weight
(Table 1, Example 4) and Examples 110 to 112 use a Hofmann degradation product of 47
k daltons molecular weight (Table 1, Example 3) as the promoter. Examples 113 to 115 use
a Hofmann degradation product of 77 k daltons (Table 1, Example 2) as the promoter.
Examples 116 to 118 use a Hofmann degradation product of 200 k daltons molecular
14
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weight (Table 1, Example 1) as the promoter. Examples 119 to 121 use PVA as the
promoter. Examples 122 to 124 use PVA.HCI as the promoter. Examples 125 to 127 use
PVOH/PVA as the promoter. Eka"~p'es 128 to 130 use cationic potato starch as thepromoter. These examples show that both PVA and PVA.HCI are effective promoters for
5 ASA. Both are ASA-reactive. It again shows that PVOH/PVA is an effective promoter, and
that the effectiveness of the Hofmann degradation products increase with increasing
molecular weight.
Table Xl
Dosage of
Fx~rnple C:~tionic Polymer Ink Penetr~tion
(% on fiber) (sec)
107 0.30 4
108 0.45 5
109 0.60 60
110 0.30
111 0.45
112 0.60
113 0.15 6
114 0.30 24
115 0.45 127
116 0.075 194
117 0.15 153
118 0.225 240
119 0.15 258
120 0.30 449
121 0.45 260
122 0.15 129
123 0.30 477
124 0.45 406
125 0.0375 178
126 0.075 280
127 0.15 337
128 0.15 108
129 0.30 334
130 0.45 326
CA 0222760~ 1998-01-23
WO 97/05330 PCTAJS96/12231
EXAMPLES 131 TO 154 (Comparative)
Table Xll presents a further co",pa,~live evaluation of PVOH/PVA polymer as a
sizing promoter for ASA. The performance of PVOH/PVA polymer as sizing promoter is
compared to the use of cationic starch as the promoter. The synthetic polymer is evaluated
5 under varying mole percent of PVA in the PVAtPVOH polymer as well as under varying
molecular weight and dosage of the PVAtPVOH polymer. Each evaluation is conducted
using 0.15 mole % on fiber of ASA. It is shown that at higher PVA mole % content (i.e.
at 6 or 18 mole %) the PVOHtPVA promoter is more efficient than cationic starch. At
levels of 3 mole % of PVA or less the copolymer is not effective as a promoter. It is also
10 shown that better efficiency is obtained with higher molecular weight samples.
Table Xll
Cationic Molecular Ink
FY~rnr'~ PVA ~h W~i~ht ~Q~g~ PenetrAtinr~
mole % (% on fiber) (k daltons) (% on fiber) (sec)
131 <1 -- 50-120 0.15
132 <1 -- 50-120 0.30
133 <1 -- 50-120 0.45
134 3 -- 50-120 0.15
135 3 50-120 0.30
136 3 -- 50-120 0.45
137 6 -- 36 0.0375 5.5
138 6 -- 36 0.075 21
139 6 -- 36 0.15 48
140 6 -- 95 0.0375
141 6 -- 95 0.075 23
142 6 -- 95 0.15 98
143 6 -- 80-140 0.0375 47
144 6 -- 80-140 0.075 119
145 6 -- 80-140 0.15 378
146 18 -- 75 0.0375 30
147 18 -- 75 0.075 259
148 18 -- 75 0.15 204
149 -- 0.15 -- -- 34
150 -- 0.15 -- -- 13.6
151 -- 0.30 -- -- 239
152 -- 0.30 -- -- 271
153 -- 0.45 -- -- 275
154 -- 0.45 -- -- 540
CA 0222760~ 1998-01-23
W O 97/05330 PCT~US96/12231
EXAMPLES 1~5 TO 159 (Comparative)
The paper that is used for the exampies in Table Xlll is made on a pilot paper
machine. The ASA is emulsified either with a copolymer of acrylamide/methyl chloride
quaternary salt of dimethylaminoethyl methacrylate (AMD/Q6) or with cationic potato starch.
5 The emulsion is added to the pulp at the down leg of the stuff box. ASA dosage is kept
constant at 0.175%. The fumish is 70130 bleached hardwoodlsoftwood with 25% (on dry
fiber) added precipitated CaCO3. In Example 155, the AMD/Q6 copolymer is provided in
a final ratio to ASA of 0.13/1. In Example 156, the total AMD/Q6 copolyrner is provided as
in Example 155, but with additional polymer addition bringing the final ratio of AMD/Q6 to
ASA as 1.0/1. In Example 157, the ASA emulsion is made using a 90/10 AMD/Q6 inverse
emulsion copolymer, with a final polymer/ASA ratio of 0.13/1. The result of these three
examples show the average sizing for Examples 155, 156 and 157 as 20, 41 and 5
secon~s, respectively. This demon~lldles that the sizing was low, relative to the standard
emulsions. Increasing the level of copolymer from 0.13:1 to 1:1 resulted only in a small
15 increase in sizing. It is shown that synthetic cationic polymers do not give sizing (or
increase sizing efficiency) if the polymer is not reactive with the sizing material. In
comparison, Examples 158 and 159 are ASA emulsions made using cationic starch in a
ratio to ASA of 2.1/1. The much higher sizing values show the promoting effect of the ASA
reactive cationic starch.
Table Xlll
Ratio of Ratio of
FY~m~le CAtionic StArch CAtionic Polymer Ink PenetrAtion (sec~
155 - 0.13 20
156 - 1.0 41
157 - 0.13 5
1~8 2.1 - 225
159 2.1 - 219
