U.S. patent application number 12/526341 was filed with the patent office on 2010-04-08 for method for functionalising carbohydrates.
This patent application is currently assigned to ARKEMA FRANCE. Invention is credited to Christophe Calais, Dominique Lachenal, Gerard Mortha.
Application Number | 20100084101 12/526341 |
Document ID | / |
Family ID | 38461097 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100084101 |
Kind Code |
A1 |
Calais; Christophe ; et
al. |
April 8, 2010 |
METHOD FOR FUNCTIONALISING CARBOHYDRATES
Abstract
The invention relates to a method for functionalising
carbohydrates, that comprises at least one step during which the
carbohydrates react with an oxidizing agent in the presence of
copper-phenanthroline complex. The invention more particularly
relates to a method for functionalising cellulose fibers for the
paper industry.
Inventors: |
Calais; Christophe;
(Meyzieu, FR) ; Lachenal; Dominique; (Saint-Martin
D' Heres Cedex, FR) ; Mortha; Gerard; (Saint-Martin
D' Heres Cedex, FR) |
Correspondence
Address: |
ARKEMA INC.;PATENT DEPARTMENT - 26TH FLOOR
2000 MARKET STREET
PHILADELPHIA
PA
19103-3222
US
|
Assignee: |
ARKEMA FRANCE
Colombes
FR
|
Family ID: |
38461097 |
Appl. No.: |
12/526341 |
Filed: |
January 25, 2008 |
PCT Filed: |
January 25, 2008 |
PCT NO: |
PCT/FR2008/050115 |
371 Date: |
October 28, 2009 |
Current U.S.
Class: |
162/24 ;
162/78 |
Current CPC
Class: |
C08B 15/04 20130101;
D21C 9/16 20130101; D21C 9/10 20130101; C08B 15/10 20130101; D21C
9/1036 20130101 |
Class at
Publication: |
162/24 ;
162/78 |
International
Class: |
D21B 1/16 20060101
D21B001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2007 |
FR |
0753244 |
Claims
1. A method for functionalising carbohydrates, including paper
pulps, cellulose and polysaccharides, including starch, comprising
reacting carbohydrates with an oxidizing agent in the presence of a
copper-phenanthroline complex.
2. A method for functionalising cellulosic fibers of paper pulps
characterized in that it comprises delignifying lignocellulosic
material to form cellulosic material followed by bleaching the
cellulosic material with an oxidizing agent in the presence of a
copper-phenanthroline complex.
3. A method for functionalising cellulosic fibers of paper pulps
characterized in that it comprises the steps of: delignifying
lignocellulosic material to form cellulosic material, (b) treating
the cellulosic material with alkaline to extract lignin, (c)
bleaching the lignin with an oxidizing agent in the presence of a
copper-phenanthroline complex.
4. The method as claimed in claim 2, characterized in that the
bleaching is carried out on cellulosic material having a Kappa
number .ltoreq.6 and an ISO brightness .gtoreq.60%.
5. The method as claimed in claim 1, characterized in that the
oxidizing agent is hydrogen peroxide.
6. The method as claimed in claim 1, characterized in that the
temperature is lower than 85.degree. C.
7. The method as claimed in any one of claims 2 to 6, characterized
in that the reagent(s) for the delignification step is (are) oxygen
(stage O) or oxygen in combination with hydrogen peroxide (stage
Op), chlorine dioxide (stage D) and/or ozone (stage Z).
8. The method as claimed in claim 2, characterized in that the
bleaching is via chlorine dioxide and/or hydrogen peroxide.
9. The method as claimed in claim 2, characterized in that the
paper pulp is of the chemical type.
10. The method as claimed in claim 2, further comprising
crosslinking said cellulosic materials after bleaching.
11. The method as claimed in claim 3, characterized in that the
bleaching is carried out on cellulosic material having a Kappa
number .ltoreq.6 and an ISO brightness .gtoreq.60%.
12. The method as claimed in claim 2, characterized in that the
oxidizing agent is hydrogen peroxide.
13. The method as claimed in claim 3, characterized in that the
oxidizing agent is hydrogen peroxide.
14. The method as claimed in claim 1, characterized in that the
temperature is lower than 85.degree. C.
15. The method as claimed in claim 1, characterized in that the
temperature between 35 and 65.degree. C.
16. The method as claimed in claim 2, characterized in that the
temperature is lower than 85.degree. C.
17. The method as claimed in claim 2, characterized in that the
temperature is between 35 and 65.degree. C.
18. The method as claimed claim 3, characterized in that the
treatment temperature is lower than 85.degree. C.
19. The method as claimed in claim 3, characterized in that the
treatment temperature is between 35 and 65.degree. C.
20. The method as claimed claim 3, characterized in that the
bleaching is via chlorine dioxide and/or hydrogen peroxide.
21. The method as claimed in claim 3, characterized in that the
paper pulp is of the chemical type.
22. The method as claimed claim 3, further comprising crosslinking
said lignin after bleaching.
Description
[0001] The invention relates to a method for functionalising
carbohydrates. It relates in particular to a method for
functionalising cellulose fibers for the paper industry.
[0002] Functionalisation consists of the creation of carbonyl and
in particular carboxyl functions, produced by oxidation of the
alcohol functions naturally present in carbohydrates, such as for
example cellulose paper pulp fibers or starches.
[0003] Document WO 92/18542 describes the oxidation of
carbohydrates in an alkaline aqueous medium using oxygen gas in the
presence of a metal ion selected from group VIII of the Periodic
Table, and a substance acting as a ligand of the metal ion. This
document teaches that the metal ion is preferably introduced into
the alkaline medium in the form of a soluble salt. It further
teaches that the ligand is preferably a polydentate amine.
[0004] Document U.S. Pat. No. 6,136,041 discloses the use of an
additive to activate bleaching solutions for lignocellulosic fibers
in oxidizing conditions. This document teaches that the additive
may be selected from phenanthrolines and polypyridyls.
[0005] Document WO 03/080925 describes a delignification and
prebleaching step in which the oxygen is used in combination with
hydrogen peroxide in the presence of a phenanthroline-copper
complex. The chemical paper pulp delignification and bleaching
method consists in subjecting the pulps, after digestion, to
several steps of delignifying and/or bleaching treatment. The first
steps essentially consist in completing the delignification
resulting from the digestion and the subsequent steps of bleaching
steps.
[0006] In general, the phase of completion of delignification after
digestion (also called prebleaching) consists of one to two
delignification steps with reagents, such as for example oxygen
(stage O) or oxygen in combination with hydrogen peroxide (stage
Op), chlorine dioxide (stage D) and/or ozone (stage Z). On
completion of the delignification treatment steps, the paper pulp
may be subjected to treatment with alkaline reagents, such as for
example caustic soda, in order to solubilize and extract the lignin
attacked (alkaline extraction stage denoted by E). This treatment
can be carried out in combination with oxygen (stage Eo) or in
combination with hydrogen peroxide (stage Ep) or in combination
with oxygen and hydrogen peroxide (stage Eop). This treatment can
also be inserted between the delignifying treatment steps.
[0007] Finally, the bleaching step or steps consist in subjecting
the delignified and prebleached pulp to treatment by bleaching
agents, such as for example chlorine dioxide or hydrogen peroxide.
In general, the actual bleaching concerns pulps having a Kappa
number .ltoreq.6 and an ISO whiteness 60% (that is obtained after
delignification and prebleaching). The Kappa number and the
whiteness are measured respectively according to the standards ISO
302 and ISO 2470.
[0008] The applicant has now developed a method for functionalising
carbohydrates, including paper pulps, cellulose and
polysaccharides, including starch.
[0009] This method comprises at least one step during which the
carbohydrates react with an oxidizing agent in the presence of a
copper-phenanthroline complex.
[0010] The copper-phenanthroline complex may be formed from a
copper salt and a phenanthroline ligand. The phenanthroline
concentration is preferably between 0.001 and 1% and advantageously
between 0.01 and 0.1% by weight of the material to be
functionalised.
[0011] The cooper concentration is preferably between 0.0001 and
0.030% (or 1 and 300 ppm) and advantageously between 0.0001 and
0.015% (or 1 and 150 ppm) by weight of the material to be
functionalised.
[0012] The oxidant concentration is preferably between 1 and 20%
and advantageously between 2 and 10% by weight of the material to
be functionalised.
[0013] As oxidizing agent, mention can be made in particular of
peroxides, in particular hydrogen peroxide, peracids, in particular
peracetic acid and performic acid, oxygen, ozone, chlorine,
chlorine dioxide and sodium hypochlorite. Hydrogen peroxide is
advantageously selected as the oxidant.
[0014] The phenanthroline is preferably selected from
1,10-phenanthroline, 4,7-phenanthroline and 1,7-phenanthroline;
1,10-phenanthroline is particularly preferred.
[0015] This method is suitable for functionalising cellulose and in
particular for functionalising cellulose fibers of paper pulp.
[0016] According to a first alternative of the invention, the
method comprises at least one step of delignification of the
lignocellulosic material followed by at least one bleaching step
during which the delignified cellulosic material is subjected to a
treatment with an oxidizing agent in the presence of a
copper-phenanthroline complex.
[0017] According to a second alternative of the invention, the
method comprises at least one step of delignification of the
lignocellulosic material, at least one alkaline extraction stage,
at least one bleaching step and at least one treatment with
oxidizing agent in the presence of a copper-phenanthroline complex,
and the latter can be carried out during the alkaline extraction
stage and/or the bleaching step.
[0018] Regardless of the alternative, the oxidizing agent treatment
in the presence of a copper-phenanthroline complex is preferably
carried out on pulp having a Kappa number .ltoreq.6 and an ISO
brightness .gtoreq.60%, advantageously on pulp having a Kappa
number .ltoreq.2.5 and an ISO whiteness .gtoreq.75% and
advantageously preferred on pulp having a Kappa number .ltoreq.2
and an ISO whiteness .gtoreq.80%.
[0019] This treatment can be advantageously carried out in the
final bleaching step or after the final bleaching step.
[0020] The reagents for the delignification step may be oxygen
(stage O) or oxygen in combination with hydrogen peroxide (stage
Op), chlorine dioxide (stage D) and/or ozone (stage Z).
[0021] The bleaching step can be carried out in the presence of
chlorine dioxide and/or hydrogen peroxide.
[0022] The temperature of the treatment using oxidizing agent in
the presence of a copper-phenanthroline complex is preferably lower
than 85.degree. C. and advantageously between 35 and 65.degree.
C.
[0023] The treatment time depends on the temperature selected, and
is preferably shorter than 1 hour.
[0024] The consistency of the pulp during the treatment is
preferably between 5 and 20% by weight and the reaction medium is
preferably aqueous. The pH of the reaction medium is advantageously
between 9 and 12.
[0025] The present invention is suitable for any type of paper pulp
(mechanical, chemical, recycled pulp), preferably chemical paper
pulp.
[0026] Chemical paper pulps or chemical pulps are those obtained by
digestion of lignocellulosic materials in particular of wood. Among
chemical pulps, a distinction is made between kraft or sulfate
pulps, sulfite or bisulfite pulps, semi-chemical or neutral sulfite
pulps, pulps after digestion with a solvent like those obtained by
the Organosolv processes (Oilman's Encyclopedia of Industrial
Chemistry, 5.sup.th Edition, vol. A, 18, 1991, pages 568-569),
sulfite-anthraquinone pulps.
[0027] All types of wood are suitable: coniferous woods such as the
various species of pines and firs, deciduous woods such as for
example birch, poplar, beech and eucalyptus.
[0028] The pulps thus functionalised can then be crosslinked to
increase the strength of the desired end product.
[0029] The functionalisation method according to the present
invention has the advantage of being easily incorporated in a
conventional paper pulp treatment line and serves to avoid the use
of costly and ineffective additives.
EXPERIMENTAL PART
[0030] The pulps subjected to the treatment with oxidizing agent in
the presence of copper-phenanthroline complex had a Kappa number
<1 and an ISO brightness >85%. These previously delignified
and bleached pulps were of industrial origin: [0031] Bleached
cotton linters pulp (example 1), consisting nearly exclusively of
pure cellulose and containing very little hemicellulose (<0.5%)
[0032] Bleached resinous kraft pulp (examples 2, 4 and 5) (mixed
conifers) [0033] Bleached deciduous kraft pulp (examples 3 and 6)
(mixed hardwoods).
EXAMPLES 1 TO 3
[0034] The oxidizing agent used was hydrogen peroxide and the
quantity employed was 6% by weight of the pulp to be treated. The
quantity of copper-phenanthroline complex employed was 0.1% by
weight of the pulp to be treated. The consistency of the pulp was
6% by weight and 2% by weight of caustic soda was added to the
pulp. The treatment temperature was 45.degree. C. and the time was
20 minutes.
[0035] The following procedure was applied: the pulp was dispersed
in water and then placed in a plastic bag. The reagents were then
introduced and mixed with the pulp in the following order: catalyst
(Cu(Phen).sub.2.sup.2+ complex), caustic soda solution, hydrogen
peroxide solution, so that the functionalisation stage took place
at the desired consistency. The bag was then sealed and immersed in
a water bath at the temperature and for the time selected.
[0036] The carboxyl content measured before and after
functionalisation under the conditions described above is given in
Table 1. This carboxyl content was measured by the methylene blue
method (Tappi standard T 237, Wilson W. K., Mandel, J.
"Determination of Carboxyl in Cellulose", Tappi 44 (2), 131
(1961)).
TABLE-US-00001 TABLE 1 Results of functionalisation tests on three
industrial pulps Example 1 Example 2 Example 3 Initial carboxyl 8 8
12 content (meq/100 g) Final carboxyl 25 28 27 content (meq/100
g)
EXAMPLE 4
[0037] The same procedure was followed as in Example 3, except that
the treatment time was 50 minutes. The final carboxyl content
obtained was 45 meq/100 g.
EXAMPLES 5-6
Crosslinking of Functionalised Pulps
[0038] After the functionalisation treatment, the pulps were
crosslinked by heat treatment at 120.degree. C. in the presence of
sodium dihydrogenophospate. Example 5 relates to the crosslinking
of the pulp obtained in example 2, where example 6 concerns the
crosslinking of the pulp obtained in example 3. Table 2 gives the
variations in the properties of the pulps obtained after
functionalisation+crosslinking. These variations are given in % of
the value obtained in the absence of functionalisation.
TABLE-US-00002 TABLE 2 Variation in mechanical properties of
crosslinked pulps after functionalisation treatment Example 5
Example 6 Bulk -0.5% -5.6% Stiffness factor +43% +72% Breaking
length +74% +53% Elongation index +75% +57% Tear factor +495% +157%
Burst factor +190% +157%
* * * * *