Note: Descriptions are shown in the official language in which they were submitted.
~S~7~
The present invention relates to a process for inhibit-
ing the separation of resins in the production of paper, box board
and paper board.
Copending Canadian Application No. ~ S~/ filed
~eb~dr~ 2~, ~97~ discloses a process for preventing
separation of resins in the production of paper, box board and
paper board from a resin containing pulp or mechanical pulp which
comprises adding to the pulp an additive including at least one
L phosphonic acid compound having the general formula
3H2 - -
R1 - C R3
I
R2
wherein
R is H, -CH3, -NH2, -CH2OH, -(CH2)nCH3, 2 n
~(CH2) n~NH2
-N =C or ~(CH2)nPo3H2
(CH2)nC 3
~CH2-P03H2
R2 is H, -OH, -PO3H2, -N
CH2-P03H2
~ (CH2)nCOOH ~ CH2P3H2
-(CH2)n~COOH, -CH , -N ~CH2PO3H2
(CH2)nCOOH 2 n ~CH PO H
/ CH2PO3H2 ~ C 2 3 2
H2O3P H2C~N (CH2)n \ ¦ N / 2 3 2
CH2P03H2, ~/ -- CH2P2H2
r I cH2-N--CH2PO3H2
or l l / CH2PO3H2
-N
C 2 3 2
~1~
-- 1 --
R3 is H, -OH, -NH2, -CH3 -(CH2)nCH3, -(CH2)nCOOH,
/ CH2COOH
-NH-(CH2)n-po3H2~ NH.C 2 -N
CH2COOH
and n is a number from 0 to 6 or an alkali metal salt thereof
either alone or together with an aminopolycarboxylic acid
and/or a hydroxy acid and their alkali salts in amounts of
0.02 to 1.0% by weight based on the dry pulp.
Suitable phosphonic acid compounds of the formula
for use in the process include aminomethane diphosphonic
acid, aminotrismethylenephosphonic acid, diethylenetriamine
pentamethylene phosphonic acid, propylene-diamine tetra-
methylene phosphonic acid, ethylene diamine tetramethylene
phosphonic acid, 1,2-cyclohexane diaminotetramethylene
phosphonic acid, aminomethylcyclopentyl amine (2) -tetra-
methylene phosphonic acid, N-phosphonomethane-l-aminoethane-
l,l-diphosphonic acid and acetamidino-ethane diphosphonic acid.
Particularly effective nitrogen free compounds include 1-
hydroxyethane-l,l-diphosphonic acid and l-hydroxy propane-
1,1,3-triphosphonic acid. Also carboxyalkane amino alkane
phosphonic acids such as bis-N-carboxy-methane-amino ethane
diphosphonic acid and phosphono butane tricarboxylic acid may
be used.
The hydroxy acids particularly include gluconic acid,
citric acid and tartaric acid. The polyaminocarboxylic acids in-
clude ethylene diamine tetracetic acid, diethylene triamine
pentaacetic acid and nitrilo-triacetic acid.
The additive is suitably added in an amount from 0.02
to 1.0~ by weight, preferably 0.04 to 0.3% by weight based
on the weight of the dry cellulose-containing material.
-` ~05~758
Substances having a dispersing or wetting effect e.g.
alkylphenol polyglycol ether can be used for improving the action
of the additive.
When a mixture of phosphonic acid, polyamino carboxy-
lic acids and hydroxy acids and their alkali salts are used as
the additive the ratio of phosphonic acid to the remainder of
the components is suitably in the range 1:6 to 6:1. A mixture
of amino lower alkane phosphonic acids containing 2 to 6 carbon
atoms, diethylene triamine pentacetic acid and gluconic acid
and their alkali salts for the additive has been found to be
particularly preferred.
It has now been found that the additive in the aforesaid
process may contain the orthophosphoric acid and/or poly-
phosphoric acid and their alkali salts in addition to or in
place of the aminopolycarboxylic acids and/or hydroxy acid
and their alkali salts with similar or even superior results.
According to the present invention therefore there
is provided in the production of paper, cardboard or paperboard
from a resin containing pulp or a mechanical pulp a process
for inhibiting the separation of resins from said pulp which
comprises adding to said pulp an additive including at least
one phosphonic acid having the general formula
P3H2
I
Rl f R3
R2
~05~
wherein
R is H, -CH3, -NH2, -CH2OH (CH2)ncH3' 2 n
/ (CH2)n NH2
-N = C ~ or ~(cH2)nPo3H2
(CH2)n 3
~CH2 -P03H2
R2 is H, -OH, -PO3H2, -N
CH2 -P03H2
~(CH2 ) nCOOH ~CH2P3H2
-(CH ) ~COOH, -CH , -N
2 n \ (CH2)nCOOH \ ~ CH2PO3H2
/ CH2PO3H2 ~ CH2 3 2
H2O3PH2c- N (CH2)n \ ~ N ~ 2 3 2
CH2P03H2--CH2P03H2
or I-CH2 -N - CH2PO3H2
~ ~CH2P3H2
R is H, -OH, -NH2, -CH3 ~(CH2)nCH3' 2 n
~CH2COOH
N ( 2)n 3 2' 2
CH2COOH
and n is an integer from 0 to 6 or an alkali salt thereof
and at least one member selected from an orthophosphoric acid
and a polyphosphonic acid or an alkali salt thereof, said
additive being present in the pylp in an amount from 0.02 to
1.0% based on the weight of the dry pulp.
The present invention also provides an additive for
use in said process which additive comprises
1~5~758
(a) at least one phosphonic ac~d having the general
formula
P3H2
Rl f R3
R2
wherein
Rl is H, -CH3, -NH2, -CH OH -(CH2) CH , -(CH ) COOH,
/(CH2)n-NH2
-N = C or ~(cH2)nPo3H2
(CH2) nCH3
CH2 -P03H2
R2 is H, -OH, -PO3H2, -N
CH -PO H
(CH2)nCH /n ~CH2P3H2
-(CH ) COOH, -CH , -N
2 n (CH2)nCH \/ H2PO3H2
CH2PO3H2 ~ N CH2 3 2
H2O3PH2c- N-(CH2)n -N \ ' 2 3 2
or I _ I-CH2- N -CH2po3 2
~ CH2P03H2
l )-N
2 3 2
i H -OH -NH2, -CH3 -(CH2)nCH3, 2 n
CH2COOH
~NH~(CH2)n~P3H2' -NH CH2COOH' -N
CH2COOH
and n is a number from 0 to 6
and (b) at least one member selected from orthophosphonic and
polyphosphoric acids and their alkali salts the weight ratio
of (a) to tb) approximately in the range of 1:10 to 10:1.
A mixture of said phosphonic acids and acid or neutral
salts of orthophosphoric acid is preferable as the additive.
The proportions of the components of the additive may vary within
wide limits and suitably range from about 10:1 to 1:10. An
economically desirable ratio in the additive is approximately
1 part of phosphonic acid to 4 parts of phosphoric acid, computed
as a 100% substance. The proportions i~ the mixture may also
be so selected to be in an inverse order when special circum-
stances make this necessary.
From the group of the polyphosphoric acids and their
salts those compounds having the general formula Hn+2PnO3n+l,
wherein n is a number from approximately 2 to60, may suitablly
be used. Such compounds include for examplej diphosphoric acid,
triphosphoric acid, tetraphosphoric acids and medium to higher
polyphosphoric acids and their alkali salts.
In practice the components of the additive may be
added to the starting material either individually or in
admixture. The components of the additive may be added at
different points during the process. In the production of pulp
the additive components may be added to the cooking acid, to
the hogged chips or during the washing process or during the
bleaching process. In the production of mechanical wood pulp
the additive can be added to the water of the pulp grinder or
to the freshly prepared mechanical wood pulp. In the production
of paper the most favourable point of addition of the additive
-- 6 --
75~
depends on the point of maximum resin separation. The additive
is usually added in the hollander or pulper. However, depending
on the operating conditions, it can also be added to a pulp vat
or to the breast box.
The pH values of the paper pulp may be constant, for
example, at a value between 4.5 and 8. Under certain conditions
these limits can be decreased or increased.
The present invention will be further illustrated by
way of the following Examples in which in order to provide
satisfactory means of comparison, all the tests (Examples 1 to
3) were carried out at a pH value of 7.
Example 1
Without additive:
In a sulphite pulp, which was known to cause diffi-
culties on the paper machine due to separation of resin, the
total resin content was determined by extraction with dichloro-
methane and a value of 0.448% was thus obtained. The proportion
of detrimental resin was 8.7% of the total resin content. This
amount of resin was determined in the following manner:
100 g of the above-mentioned pulp were mashed and a 4
suspension;n water was thus obtained. This pulp suspension was
circulated in a laboratory hollander without grinding. The temp-
erature was 40C and the pH value of the suspension was 7. In
order to collect the resin separated from the pulp, a previously
cleaned brass plate was suspended in the circulating paper pulp.
At the end of the test the pulp was discharged from the labor-
atory hollander, whereupon the hollander and the brass plate were
rinsed with water. The resin deposited on the hollander walls
and on the suspended brass plate was removed by means of cellu-
lose wadding, which had been wetted with dichloromethane. The
wadding was then extracted with dichloromethane. The brass
plate was then rinsed several times with dichloromethane. The
~75~
entire dichloromethane from the extraction and from the rinsing
liquid was collected and evaporated. The remaining resin was
weighed out. 0.0391 g of resin was thus obtained corresponding
to 8.7% based on the total resin content.
Example 2
The same pulp as in Example 1 was treated in the same
manner and, prior to the circulation period, it was mixed with a
solution of 4 parts of 75% phosphoric acid and 3 parts of 18%
ethylenediamine tetramethylene-phosphonic acid, which had been
adjusted with a 50% solution of caustic soda to a pH value of 7,
and was further treated in the same manner as in Example 1.
The proportion of detrimental resin was 0.015%, based
on the weight of the pulp (3.35% by weight of the total resin
content.)
Example 3
This test was carried out similarly to the tests in
Examples 1 and 2.
As the agent for preventing resin separation, 0.5%
of a solution of 17 parts of a 37% diethylenetriamine-penta-
methylene-phosphonic acid and 23 parts of a 75% phosphoric acid,
which had been adjusted with a 50% caustic potash solution to a
pH value of 7, was added prior to the start of the circulation
period.
The resin separated during the test was 0.0112~ based
on the weight of the pulp (2.5% of the total resin content).
Example 4
3800 litres of water, 120 kg of unbleached sulphite
pulp and 80 kg of bleached sulphite pulp were put into a pulp
engine and ground to 40SR.
Prior to the grinding, 3 kg of a 10% solution of a
sodium polyphosphate, the average composition of which corresponds
to the formula NalOP8025, and 0.5 kg of a 20% solution of the
sodium salt of N-phosphono methylene-l-aminomethane-l,l-diphos-
phonic acid were added to the fibrous pulp mixture.
After the grinding and gluing with a 4~ resin glue the
pulp was discharged from the pulp engine into the pulp vat.
This manner of treating the pulp was repeated until the material
requirement for a 2-day production of paper was obtained. The
accumulated paper pulp was then processed to paper on the paper
machine. Although the pulp used was known to cause difficulties
due to separation of resin, evident from torn-off paper and
holes in the paper, such disadvantages were not observed during
the test.
The substantial reduction in the separation of resins,
as shown in the examples hereinbefore, are sufficient for re-
moving the usual difficulties caused by resins in paper making.
g _
