U.S. patent application number 12/522590 was filed with the patent office on 2010-03-11 for grafting method by means of ionising radiation using a reactive surfactant molecule, textile substrate and battery separator obtained by means of grafting.
This patent application is currently assigned to LAINIERE DE PICARDIE BC. Invention is credited to Nabila Kourda, Philippe Le Thuaut.
Application Number | 20100058542 12/522590 |
Document ID | / |
Family ID | 38445663 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100058542 |
Kind Code |
A1 |
Kourda; Nabila ; et
al. |
March 11, 2010 |
Grafting Method By Means of Ionising Radiation Using a Reactive
Surfactant Molecule, Textile Substrate and Battery Separator
Obtained by Means of Grafting
Abstract
A method for grafting functional chemical groups to a textile
substrate is provided, wherein the substrate is impregnated with a
solution of a functional molecule, containing the functional
chemical group and a group that is reactive to ionising radiation,
as well as a surfactant molecule that can improve the wettability
of the textile substrate by the solution. The surfactant molecule
contains at least two types of groups that are reactive to ionising
radiation. Subsequently, ionising radiation is applied to the
impregnated textile substrate and the reaction of the reactive
groups bridge-grafts the functional molecules to the surfactant
molecules. A textile substrate and a battery separator grafted
using the above method are also described.
Inventors: |
Kourda; Nabila; (Peronne,
FR) ; Le Thuaut; Philippe; (Lyon, FR) |
Correspondence
Address: |
BACHMAN & LAPOINTE, P.C.
900 CHAPEL STREET, SUITE 1201
NEW HAVEN
CT
06510
US
|
Assignee: |
LAINIERE DE PICARDIE BC
Peronne
FR
|
Family ID: |
38445663 |
Appl. No.: |
12/522590 |
Filed: |
January 28, 2008 |
PCT Filed: |
January 28, 2008 |
PCT NO: |
PCT/FR08/00098 |
371 Date: |
July 9, 2009 |
Current U.S.
Class: |
8/115.6 |
Current CPC
Class: |
D06M 14/28 20130101;
D06M 14/18 20130101; D06M 14/32 20130101 |
Class at
Publication: |
8/115.6 |
International
Class: |
D06M 15/37 20060101
D06M015/37 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 29, 2007 |
FR |
0700593 |
Claims
1-17. (canceled)
18. A method for grafting functional chemical groups on a textile
substrate, said method comprising the steps of impregnating said
textile substrate with a solution of a functional molecule
comprising a functional chemical group and a reactive group in
ionising radiation, and a surfactant molecule which is capable of
improving the wettability of the textile substrate by said
solution, which surfactant molecule comprises at least two types of
reactive groups in ionising radiation, and applying ionising
radiation on the impregnated textile substrate to graft functional
molecules by means of coupling with the surfactant molecules and by
means of a reaction of the reactive groups.
19. The grafting method according to claim 18, further comprising
basing the textile substrate on synthetic material fibres.
20. The grafting method according to claim 18, providing a solvent
which is water.
21. The grafting method according to claim 18, further comprising
providing said solution with a functional chemical group capable of
exchanging cations or anions.
22. The grafting method according to claim 21, further comprising
selecting the cation exchange chemical group from the group
consisting of sulphonic, carboxylic, and phosphoric groups, and the
amine and ammonium groups.
23. The grafting method according to claim 22, further comprising
selecting the functional molecule from the group consisting of
sulphoalkyl methacrylates, carboxylic alkyl acrylates or
methacrylates, phosphoric alkyl methacrylates, ethylene glycol
methacrylate phosphate, dialkylamonoalkyl methacrylates, and alkyl
trialkyl ammonium methacrylates.
24. The grafting method according to claim 18, further comprising
providing the solution with two functional molecules each
comprising a different functional chemical group, and arranging the
ionising radiation applying step to graft each of the functional
chemical groups on one face of the textile substrate,
respectively.
25. The grafting method according to claim 24, wherein said
ionising radiation applying step comprises applying ionising
radiation on each of the faces, with a penetration thickness of
said radiation which is less than the thickness of the textile
substrate.
26. The grafting method according to claim 18, further comprising
selecting the reactive groups in ionising radiation from the group
consisting of hydroxyl, carboxyl, carbonyl, acrylate, methacrylate,
allyl, amine, amide, imide, and urethane groups.
27. The grafting method according to claim 26, further comprising
selecting the surfactant molecule from the group consisting of
diacrylates, polyethylene glycol diacrylates (PEG DA),
triacrylates, ethoxylated trimethylolpropane triacrylates.
28. The grafting method according to claim 18, wherein the
impregnating step is performed by means of padding, with the
impregnated textile substrate being dried before the application of
ionising radiation.
29. The grafting method according to claim 18, wherein said
ionising radiation step comprises electron bombardment.
30. A textile substrate wherein at least one surface is grafted
with functional chemical groups, said grafting being performed by
means of coupling with a surfactant molecule using a method
according to claim 18.
31. The textile substrate according to claim 30, wherein said
substrate is based on synthetic material fibres.
32. The textile substrate according to claim 30, wherein the
functional chemical group is capable of exchanging cations or
anions.
33. The textile substrate according to claim 30, wherein said
substrate comprises two faces which are each grafted with a
different functional chemical group.
34. A battery separator comprising a textile substrate whereon
sulphonic groups and phosphoric and/or carboxylic groups are
grafted, said grafting being performed by means of coupling with at
least one surfactant molecule using a method according to claim 18.
Description
BACKGROUND
Field of the Invention
[0001] The invention relates to a method for grafting functional
chemical groups on a textile substrate, and a textile substrate and
battery separator grafted using such a method.
[0002] The invention particularly applies to the grafting of
textile substrates so as to give them an ion exchange function. In
particular, the invention proposes a method for grafting a bipolar
textile substrate, i.e. comprising a different ion exchange
function on each of the faces thereof.
[0003] The grafted textile substrates according to the invention
are particularly useful in the agri-food, pharmaceutical, medical,
energy, biological and environmental sectors. For example, the use
of ion exchange textile substrates according to the invention makes
it possible to:
[0004] increase the conductivity of solutions in order to improve
electrodialysis separation methods and electrochemical methods;
[0005] water softening with optionally a bacteriostatic
property;
[0006] the manufacture of biological protection masks or clothing
with virucidal properties;
[0007] electrodeionisation for the production of ultra-pure water
or for the demineralisation of molecules after synthesis;
[0008] the production of battery separators;
[0009] the development of a specific contamination indication
material for a given bacterium or virus for diagnostic
purposes;
[0010] the treatment of industrial effluents and water by means of
a continuous or batch exchange method and by means of a hybrid
electromembrane method combining ion exchange membranes and ion
exchange textile substrates.
[0011] (2) Prior Art
[0012] According to the prior art, industrial grafting methods by
means of a chemical process are known wherein molecules are fixed
on the textile substrate to be subsequently functionalised
particularly by means of reactions in acid or basic medium. In
particular, these methods involve the drawback of having to be
performed in organic solution and requiring heating. In addition,
these methods do not enable grafting of a large range of functional
chemical groups, at least simply and in a modular fashion according
to the type of textile substrate.
[0013] Furthermore, after grafting, the implementation of known
methods involves the problem of the removal of the solvent and
non-grafted chemical substance which are contained in the textile
substrate, and the problem of the subsequent recycling thereof.
[0014] Finally, the production of bipolar textile substrate with
the methods according to the prior art does not give satisfaction,
particularly with respect to the presence of each of the ion
exchange functions on a single face.
SUMMARY OF THE INVENTION
[0015] The aim of the invention is to remedy the problems of the
prior art by proposing a method for grafting functional chemical
groups on a textile substrate which is particularly simple and
modular in the implementation thereof, said method also making it
possible to obtain quality bipolar textile substrates.
[0016] To this end, according to a first aspect, the invention
proposes a method for grafting functional chemical groups on a
textile substrate, said method envisaging impregnating said
substrate with a solution of a functional molecule comprising the
functional chemical group and a reactive group in ionising
radiation, said solution also comprising a surfactant molecule
which is capable of improving the wettability of the textile
substrate by said solution, said surfactant molecule comprising at
least two types of reactive groups in ionising radiation, said
method envisaging applying ionising radiation on the impregnated
textile substrate to, by means of a reaction of the reactive
groups, graft functional molecules by means of coupling with the
surfactant molecules.
[0017] According to a second aspect, the invention proposes a
textile substrate wherein at least one surface is grafted with
functional chemical groups, said grafting being performed by means
of coupling with a surfactant molecule using such a method.
[0018] According to a third aspect, the invention proposes a
battery separator whereon sulphonic groups and phosphoric and/or
carboxylic groups are grafted, said grafting being performed by
means of coupling with at least one surfactant molecule using such
a method.
[0019] Other specificities and advantages of the invention will
emerge in the description hereinafter of various specific
embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0020] The invention relates to a method for grafting functional
chemical groups on a textile substrate, particularly functional
chemical groups capable of exchanging cations or anions with the
environment thereof, especially with a medium wherein the textile
substrate is arranged.
[0021] The method envisages impregnating the textile substrate with
a solution of a functional molecule comprising the functional
chemical group and a reactive group in ionising radiation.
According to the solubility of the functional molecule, the
solution comes at least partially in the form of an emulsion.
[0022] According to one embodiment, the impregnation is performed
by means of padding, the impregnated textile substrate being dried
before the application of ionising radiation.
[0023] In particular, the reactive groups may comprise an
unsaturated bond which, under the effect of ionising radiation,
forms a reactive free radical. In examples of embodiments, the
reactive groups in ionising radiation are selected in the group
comprising hydroxyl, carboxyl, carbonyl, acrylate, methacrylate,
allyl, amine, amide, imide, urethane groups.
[0024] According to one embodiment, the cation exchange chemical
group is selected in the group comprising the sulphonic, carboxylic
and phosphoric groups, the cation exchange chemical group being
selected in the group comprising the amine and ammonium groups.
[0025] For example, the functional molecule is selected in the
group comprising sulphoalkyl methacrylates (particularly
sulphopropyl methacrylate), carboxylic alkyl acrylates or
methacrylates (particularly acrylic acid), phosphoric alkyl
methacrylates, ethylene glycol methacrylate phosphate,
dialkylamonoalkyl methacrylates (particularly dimethylaminoethyl
methacrylate), alkyl trialkyl ammonium methacrylates (particularly
acryloxyethyltrimethyl ammonium).
[0026] Advantageously with respect to the implementation and the
environment, the solvent of the solution is water, for example the
functional molecule concentration is between 0.5 and 1 M. In
addition, the solution may comprise other agents, particularly for
improving the solubility of the molecules and/or the stability of
said solution.
[0027] In one embodiment, the textile substrate is based on fibres
made of synthetic material, particularly polyolefinic, as is
frequently required for applications envisaged for grafted textile
substrates. For example, the fibres may be made of polypropylene,
polyethylene, polyester, polyvinyl alcohol or
polytetrafluoroethylene (PTFE), or a mixture of these different
fibres.
[0028] The substrate may comprise a non-woven lap, for example
between 0.2 and 5 mm thick and weighing between 30 and 600
g/m.sup.2. In an alternative embodiment, the textile substrate may
be formed from at least one woven or knitted layer.
[0029] The grafting method according to the invention may also be
implemented with textiles made of natural fibres, such as cotton or
wool, or synthetic fibres, such as viscose or cellulose.
[0030] The method envisages, to improve the wettability of the
textile substrate by the solution, that said solution also
comprises a surfactant molecule. In this way, by improving the
affinity between the solution and the fibres of the textile
substrate, the method makes it possible to graft textile substrates
even if they are based on synthetic fibres displaying a high
hydrophobicity.
[0031] In particular, the nature and quantity of the surfactant
molecules in the solution are envisaged so that the surface tension
of the solution is similar to that of the fibres. In this way, the
textile substrate may be impregnated with a large volume of
solution, so as to increase the density of functional chemical
groups which are grafted on the textile substrate.
[0032] Furthermore, to prevent the subsequent elimination of the
surfactant molecule and improve the grafting of the functional
chemical groups, the surfactant molecules used comprise at least
two types of reactive groups in ionising radiation, said types
possibly being identical or different with respect to each other
and identical or different with respect to the functional
molecule.
[0033] In this way, by applying ionising radiation on the
impregnated textile substrate, the reaction of the reactive groups
ensures the grafting of the functional molecules by means of
coupling with the surfactant molecules. Indeed, the reactions of
the reactive groups make it possible to bind the surfactant
molecules with the fibres or with each other, and the functional
molecules with the surfactant molecules or directly with the
fibres. This creates a network between the fibres, the functional
molecules and the surfactant molecules which is particularly
resistant with respect to chemical and mechanical stress to which
the grafted textile substrate will be subjected within the scope of
the use thereof.
[0034] According to one embodiment, the ionising radiation consists
of electron bombardment wherein the power and duration may be
modulated to activate the reactive groups optimally.
[0035] Furthermore, the grafting method is particularly modular in
that the nature of the surfactant molecule may be selected
according to the textile substrate, particularly according to the
surface tension thereof, whereas the nature of the functional
molecule is selected according to the functional chemical group to
be grafted.
[0036] The surfactant molecule may be difunctional comprising two
types of reactive groups, for example the surfactant molecule may
be selected in the group comprising diacrylates, particularly
polyethylene glycol diacrylates (PEG DA). In particular, with PTFE
fibres, PEG600 DA is particularly satisfactory and, with
high-density polyethylene fibres, the use of PEG200 DA gives
satisfaction.
[0037] In an alternative embodiment, the surfactant molecule may be
trifunctional comprising three types of reactive groups, for
example the surfactant molecule may be selected in the group
comprising triacrylates, particularly ethoxylated
trimethylolpropane triacrylates. In particular, with polypropylene
fibres, ethoxylated trimethylolpropane triacrylate 20 is
particularly suitable.
[0038] After applying the ionising radiation, the textile substrate
may be washed and dried or undergo other treatments necessary for
the subsequent use thereof. In addition, before grafting, the
textile substrate may undergo specific treatments, particularly to
improve the cohesion and/or wettability thereof.
[0039] According to one embodiment, the solution comprises two
functional molecules each comprising a different functional
chemical group, the application of the ionising radiation being
arranged to graft each of the functional chemical groups on one
face of the textile substrate, respectively. In particular, the
method is arranged to graft the textile substrate on a defined
depth so as to form a superficial layer of grafted material.
[0040] In this way, a textile substrate is obtained, comprising two
faces which are each grafted with a different functional chemical
group. In particular, the textile substrate may have one anion
exchange face and one cation exchange face.
[0041] For this purpose, ionising radiation is applied on each of
the faces, with a penetration thickness of said radiation which is
less than the thickness of the textile substrate. In particular,
the application of the radiation may be performed in a passage on
each side of the textile substrate and the power of the ionising
radiation is modulated to obtain the suitable penetration
thickness. For example, the textile substrate may be grafted on one
half of the thickness thereof with anion exchange groups, and on
the other half with cation exchange groups.
[0042] In one specific envisaged application, the grafting method
makes it possible to produce a battery separator comprising a
textile substrate, particularly formed from a synthetic fibre
non-woven lap, whereon sulphonic groups and phosphoric and/or
carboxylic groups are grafted. In this way, the grafting is
performed by means of coupling with at least one surfactant
molecule as described above.
[0043] In particular, the battery is of the nickel metal hydride
type which displays good energy performances but has the drawback
of generating ammonium ions during recharging/discharging cycles.
However, ammonium ions pollute electrodes and, therefore, the
battery recharging level. In this way, the battery autonomy is
diminished.
[0044] The battery separator according to the invention is
characterised in that it includes:
[0045] via the sulphonic groups, a battery power improvement
function by improving conductivity;
[0046] via the phosphoric and/or carboxylic groups, the capture
function of the ammonium ions which are produced during the
electrochemical operation of the battery.
* * * * *