PULP CONTAINING HYDROPHILIC DEBONDER AND PROCESS FOR ITS APPLICATION

PATE A TENEUR D'ANTICOAGULANT HYDROPHILE, ET MODE D'EMPLOI CONNEXE

English Abstract

ABSTRACT OF THE DISCLOSURE
The invention provides a cellulosic pulp
having reduced tensile strength and excellent hydro-
philic properties. The pulp is produced by utilizing
a hydrophilic debonder having the general formula:
<IMG> X-
wherein:
R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [ethylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
R4 = [ethylene oxide]n or [propylene oxide]n with
N = 1 to 50.
X = Cl, I, Br, SO-4, PO=4, CH3CO2.

Claims

WHAT IS CLAIMED IS:
1. A wood pulp containing a hydrophilic
debonder having the general formula:
<IMG> X-
wherein;
R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [ethylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
R4 = [ethylene oxide]n or [propylene oxide]n with
N = 1 to 50.
X = Cl, I, Br, SO-4, PO=4, CH3CO2.
2. A process for treating cellulose pulp
fibers to reduce interfiber bonding while preserving
the hydrophilicity of the pulp comprising adding to a
cellulose pulp fiber slurry prior to or during the
formation of the slurry into a web a quaternary
ammonium compound having the formula:
14

<IMG> X-
wherein:
R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [ethylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
R4 = [ethylene oxide]n or [propylene oxide]n with
N = 1 to 50.
X = Cl, I, Br, SO-4, PO=4, CH3CO2
and forming and drying said web.
3. The process according to Claim 2 wherein
the quaternary ammonium compound is in an aqueous
carrier of from 1% to 15% by weight.
4. The process according to Claim 2 wherein
the quaternary ammonium compound applied to the fibers
is from about 0.1% to 5.0% based on the dry weight of
the cellulose.
5. The process according to Claim 2 in which
the quaternary ammonium compound is added by spraying
a solution thereof on the web and drying the web.

6. The process according to Claim 2 wherein
the quaternary ammonium compound is added to the
slurry of cellulosic pulp fibers and the pulp is
subsequently dried.
7. A process according to Claim 2 in which
the web is fiberized into cellulose fluff.
8. A process according to Claim 2 in which
the quaternary ammonium compound is added during formation
of the cellulose pulp fiber slurry into a web.
9. The combination according to Claim 1 wherein
the debonder is present between about 0.1% to 5.0% by
weight of the dry cellulosic material.
10. An absorbent fluff containing the hydro-
philic debonder of Claim 1.
11. An absorbent fluff according to Claim 10
in which the hydrophilic debonder is present at a level
of about 0.1% to 5.0% by weight of the dry cellulosic
material.
12. A diaper containing an absorbent fluff
having a hydrophilic debonder of the general formula:
16

<IMG> X-
wherein:
R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [ethylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
R4 = [ethylene oxide]n or [propylene oxide]n with
N = 1 to 50.
X = Cl, I, Br, SO-4, PO=4, CH3CO2.
13. An absorbent cellulosic based sheet stock
having a hydrophilic debonder of the general formula:
<IMG>
X-
wherein:
R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [ethylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
17

R4 = [ethylene oxide]n or [propylene oxide]n with
N = 1 to 50.
X = Cl, I, Br, SO-4, PO=4, CH3CO2.
18

Description

~7~0
FIEL~ OF THE INVENTION
This invention relates to a pulp having low
tensile strength and excellent hydrophilic properties
produced by the incorporation of a hydrophilic debonder
of the quaternary amine type.
BACXGROUND OF THE INVENTION
Over the past several years there have been
continuing attempts to improve specific properties of
cellulosic pulp-derived products by utilization of a
variety of debonding agents. These debonding agents
quite frequently include a quaternary amine component
because of the high degree of substantiveness of this
moiety for cellulose. Examples of quaternary amine
debonders can be found in U. S. patents 3,554,863;
3,554,862; 3,395,708; and Reissue 26,939 issued to
Laurence R. B. Hervey, et al. Additional examples of
such debonders can be found in U. S. patent 3,617,439
issued to Benjamin E. Chapman, Jr., Canadian patent
~ 1,020,935 issued to Louis S. Hurst, et al, British
s 20 patents 1,282,593 and 1,180,801 also issued to Hervey,
and U. S. patents 3,556,931~ 3,510,246 and 3,356,526.
Until fairly recently it has been axiomatic
' in the pulp and paper industry that the debonding
function was inversely related to hydrophilicity, i.e.
the increase in efficiency of debonding as represented
by reduced tensile strength would result in reduced
water absorption. U. S. patent 4,144,122 issued to
.,
, _

~1527~0
Jan G. Emanuelsson, et al discloses a quaternary amine
compound containing repeating ethylene oxide units at
two of the quaternary positions. These ethylene oxide
units are attached to the ammonium ion by propylene
linkages in each case and are also characterized by an
ether linkage to an aliphatic chain at both positions.
According to U. S. patent 4,144,122, debonding is
accomplished while the hydrophilic character of the
debonded pulp is improved when compared with conven-
tionally debonded pulps.
According to my invention, another class of
debonding compounds has been identified which produces
pulp which i9 more hydrophilic even than the pulp
produced accarding to U. S. patent 4,144,122.
SUMMARY OF THE INVENTION
According to this invention, a hydrophilic
debonder having the general formula:
Rl - N R3 X
wherein:
Rl = methyl, ethyl, propyl, hydrogen or hydroxyethyl.
R2 = methyl, ethyl, propyl or [e~hylene oxide]n where
N = 1 to 50.
R3 = aliphatic chain of at least 4 carbon atoms.
-- 3 --

~15Z710
R4 = [ethylene oxide]n or ~propylene oxide]n with
N = l to 50.
X = Cl, I, Br, SO4, PO4, CH3CO2.
Compounds of this general formula actually show increased
capacity for producing hydrophilic pulp when compared
to the compounds described in U. S. patent 4,144,122.
Any one or more of the selected chemicals which are
defined by the general formula set forth above may be
introduced into the pulp or pulp sheet at a number of
different places during the commercial pulp sheet
forming operations. Due to the hydrophilic properties
of the pulp after treatment with the debonder, the
utility for products produced from this pulp varies
from fluff used in conventional absorbent materials
such as sanitary napkins and diapers to absorbent sheet
stock such as paper towels. It should be noted with
regard to diapers that a series of absorbent tests
indicates a substantial increase in the absorption of
urine when compared to the more conventional debonding
agents and therefore, the products of this invention
have particular utility in diaper products. (Diapers
and diaper products as used herein are designated
specifically to include all incontinence pads and
products whether they are designed specifically to be
worn by an infant or adult or whether they are in sheet
, form such as for use with incontinent children or
, adults in a hospital or nursing home environment.)
-- 4

~1527~
Quaternarv ammonium compounds according to
this invention should be added to the wet cellulose
pulp after delignification or bleaching, either before
or during the formation into sheets or continuous webs
on the cellulose pulp machine or a paper machine. The
compounds are preferably in an aqueous carrier in a
concentration within the range of from about 1% to
about 15~ by weight of the debonder. These treating
solutions may also contain conventional viscosity re-
ducing additives such as ethanol, propanol, monoethylether or diethylene glycol and other additives tradi-
tionally associated with the debonder addition process.
The amount of the novel debonder based upon the dry
weight of the cellulose ranges from a~out 0.1% to about
5.0% and preferably between about 0.2% to about 2.5%.
The treating solution can be applied by mixing
~ith a pulp slurry. It can also be applied by spraying
or dipping, by kissing rolls or any other suitable
technique. Following application, the treated cellulose
pulp or paper can be dried in the usual manner. The
treated cellulose may be fiberized into cellulose
fluff as mentioned above for utilization in various
hygienic products. In all other ways, paper and pulp
processing related to the handling of pulp containing
these compounds is essentially conventional.
Products which fall within the definitional
category of this invention are currently commercially
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``" 1152710
available and sold under the trademark ETHOQ~AD by
Armak Industrial Chemical Division of Akzona, Inc.
of Asheville, North Carolina, and are generally used
for antistatic agents, electroplating bath additives
and dye-leveling agents. Also useful are the class
of compounds sold under the EMCOL trademark by Witco
Chemical Company, Inc., New York, New York, used for
similar purposes.
An example of the debonders of this invention
follow. The example compares the debonding ability as
measured by burst according to TAPPI Standard Method
T403 0S-76 and tensile TAPPI Standard Method T494 0S-70.
Water absorbency is determined by the following method.
Test specimens are obtained from the debonder treated
handsheets by cutting three 1" x 3" randomized strips
from each sheet. It is found that 5 sheets are appro-
priate for each test condition. Each strip is marked
at 0.5 cm intervals for 3.5 cm starting from the edge
of the 1" end.
Deionized water (surface tension = 72 dyne/cm)
is placed in a two-liter glass bottle. The test strip
is affixed in the bottle just above and perpendicular
to the liquid surface. The level of the liquid is then
adjusted until the liquid surface is just in contact
with the strip. The sheet then absorbs the liquid and
it rises up the strip. A light source behind the bottle
alds in observing the liquid rise. When the liquid

" 11527i1~
contacts the first 0.5 cm line, a timer is started.
Then each time the liquid touches the next higher
0.5 cm line, the time is recorded. This results in
90 measurements for each test condition (3 strips/sheet
x 6 measurements/strip x 5 sheets/test condition).
The rate is determined by fitting the data
to a regression of height climbed up the strip vs. the
square root of time required. The square root arises
out of consideration of the Lucas-Washburn equation.
The fits are excellent with r ~ .98 in all cases
considered. This results in rates calculated to better
than +4~. All data contained are corrected for density.
For all tests described, hand sheets having
60 lb/3000 ft.2 basis weight were produced. Three com-
pound~ made according to the general formula of this
invention were tested as debonding agents and they
were as follows:
(fH2CH20) xH +
ETHOQUAD C/25 H3C-l-Cl2.56H26.03 Cl X + Y = 15
(CH2CH2O)yH i
(fH2CH20) xH
ETHOQUAD O/12 H C-7-C18H35 Cl- X + Y = 2
(CH2CH2O~yH
,, .(clH2cH2cH2o) 40H +
EMCOL CC-42 H3C-7-CH2cH3 Cl-
CH2CH3
-- 7

These compounds were tested against QUAKER 2006, a
debonder now being sold by Quaker Chemicals of Barring-
ton, Illinois; ARQUAD 2HT-75, a commercially available
debonder sold by Armak Chemical, Inc., Chicago, Illinois;
and BEROCELL 579, 582 and 584 made in accordance with
U. S. patent 4,144,122. The structure of the BEROCE~L
compounds are not specifically identified other than
by patent number; the ARQUAD compound is a quaternary
amine with a methyl group at Rl and R2 and saturated
C18 groups at R3 and R4. The QUARER 2006 compound is
not specifically identified by the Quaker Company but
it is believed to have a five member ring structure
containing two nitrogen atoms with one nitrogen double
bonded to one of the carbons in the ring structure and
the other nitrogen having two substituent groups bound
thereto in addition to the bonding associated with the
ring structure.
When compared according to the tests described
above, the following table xepresents the values so
determined:

'-
TABLE I
Water
% Burst Tensile Absorbency
Additive Add'n Pulp (P.S.I.) (lbs/in) (cm/sec)
None --- SSK9.02 5.47 .63
EMCOL CC-42 0.4 SSK4.19 3.90 .68
EMCOL CC-42 1.0 SSK4.00 3.44 .64
EMCOL CC-42 2.4 SSK3.33 3.10 .63
ETHOQUAD C/25 0.25 SSK 6.31 4.57 .57
ETHOQUAD C/25 0.5SSK 6.23 4.65 .55 `
10 ETHOQUAD C/25 0.7SSK 5.37 4.52 .55
ETHOQUAD C/25 1.0SSK 5.32 4.49 .54
ETHOQUAD O/12 0.4SSK 5.44 4.60 .64
ETHOQUAD O/12 1.0SSK 4.85 3.83 .60
ETHOQUAD O/12 2.4SSK 4.74 3.03 .57
QUAKER 2006 0.4 SSK6.38 3.85 .31
QUAKER 2006 1.0 SSK5.60 2.68 .30
QUAKER 2006 2.4 SSK4.04 1.68 .42
ARQUAD 2HT-75 0.4SSK 4.70 3.18 .34
ARQUAD 2HT-75 1.0SSK 3.95 2.02 .32
20 ARQUAD-2HT-75 2.4 SSK3.56 2.00 .29
BEROCELL 579 0.4SSK 4.88 2.75 .39
BEROCELL 579 1.0SSK 4.52 2.69 .39
BEROCELL 579 2.4SSK 3.81 2.00 .30
¢~ BEROCELL 582 0.4SSK ~ 5.21 2.59 .45
BEROCELL 582 1.0SSK 3.76 1.83 .41
s BEROCELL 582 2.4SSK 3.51 1.76 .35
~ BEROCELL 584 0.4S5K 4.10 1.86 .45
s BEROCELL 584 1.0SSK 3.22 1.45 .42
f'~
,:,
:
g _
:
. .

l~S~
Water
% Burst Tensile Absorbency
Additive Add'n ~ (P.S.I.) (lbs/in) (cm/sec)
BEROCELL 584 2.4 SSK 2.90 1.40 .38
None --- NSK11.50 8.62 .43
ETHOQUAD C/25 0.4 NSK --- 8.30 .49
ETHOQUAD C/25 1.0 NSK --- 7.65 .44
ETHOQUAD C/25 2.5 NSK --- 6.48 .42
ETHOQUAD O/12 0.4 NSK --- 7.90 .53
ETHOQUAD O/12 1.0 NSX --- 6.57 .46
10 ETHOQUAD O/12 2.5 NSK --- 5.21 .42
ARQUAD 2HT-75 0~4 NSK --- 4.60 .23
ARQUAD 2HT-75 1.0 NSK --- 3.40 .21
ARQUAD 2HT-75 2.5 NSK --- 3.75 .20
(SSK = Southern Softwood Kraft)
~NSK = Northern Softwood Kraft)
, As can be seen from the above data, while adequate tensile
strength reduction is obtained by the debonders of thss
invention, substantially improved water absorbency is
generated by the same compounds when compared, for
example, to BEROCELL compounds which claim increased
hydrophilicity for the debonding agents described in
U. ~. patent 4,144,122. These numbers hold true to
, varying levels of debonders. Even more importantly in
, some instances at lower levels of addition of the de-
bonder of this invention, the hydrophilicity of the
debonded pulp is actually greater than that of the
~ untreated pulp.
!~
~. -- 10 --
x : .

~o
The table also illustrates that the data,
while changing slightly as the source of pulp changes,
does apply in the same general order of magnitude.
When the compounds of this invention were
tested for urine absorbency, based upon a synthetic
urine containing the following components:
Compound Concentration
,. g/l
KH2PO4 0.681
F.W. = 136
CaH4~PO4)2~H2o
F.W. = 252.1
MgSO4-7H2O 0.477
F.W. = 246.5
2S4 1.333
F.W. = 174
Na3PO4 12H20 1.244
F.W. = 380
NaCL 4.441
: F.W. = 58.4
KCL 3.161
F.W. = 74.5
NaN3 0 . 400
F.W. = 65
Urea 8.560
F.W. = 60
A Non-Ionic Surfactant 0.100
F.W. = 5000
the values obtained were again substantially greater
than those of comparable commercially available debonders
as can be seen from the table below:
.
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1152710
Synthetic
Urine
~ Absorbency
Additive P _ Add'n (cm/sec~
None SSK --- .64
EMCOL CC-42 SSK 0.4 .69
EMCOL CC-42 SSK 1.0 .66
EMCOL CC-42 SSK 2.4 .64
ETHOQUAD C/25 SSK 0.25 .55
ETHOQUAD C/25 SSK 0.5 .55
ETHOQUAD C/25 SSK 0.7 .54
ETHOQUAD C/25 SSK 1.0 .53
ETHOQUAD O/12 SSK 0.4 .65
ETHOQUAD O/12 SSK 1.0 .56
ETHOQUAD O/12 SSK 2.4 .61
QUAKER 2006 SSK 0.4 .33
, QUAKER 2006 SSK 1.0 .35
i QUAKER 2006 SSK `2.4 .40
ARQUAD 2HT-75 SSK 0.4 .25
ARQVAD 2HT-75 SSK 1.0 .20
~' ARQUAD 2HT-75 SSK 2.4 .22
None NSK --- .45
ETHOQUAD C/25 NSK 0.4 .40
ETHOQUAD C/25 NSK 1.0 .39
ETHOQUAD C/25 NSK 2.5 .40
ETHOQUAD C/25 NSK 0.4 .43
, ETHOQUAD O/12 NSK 1.0 .39
ETHOQUAD O/12 NSK 2.5 .34
ARQUAD 2HT-75 NSK 0.4 .18
ARQUAD 2HT-75 NSK 1.0 .14
ARQUAD 2HT-75 NSK 2.5 .15
- 12 -

~lsmo
As can be seen from the table above, sub-
stantial benefits are derived fr'om the utilization of
the debonder of this invention when the end product
is designed to be fluff which is subsequently utilized
in diapers or diaper related products.
Of course, as mentioned previously, the
increase in hydrophilicity can have substantial addi-
tional benefits with regard to fluff in its conventional
uses such as, for example, in sanitary napkins or other
hygienic products.
- 13 -