IL46177A - Process for preparing a complex polyelectrolyte from two types of polymer and product obtained thereby - Google Patents

Description

β ΐθ 3311 D B* lB^>8*Vl9 Μ3Π> <|»Vw» paiBii tsiam > PROCESS FOR PREPARHKT A COHPLEJC POLYELEC TROLYTB FROM WO TYPES OP POLYMER ABB PRODUCT OBTAIHED THEREB The presen preparing complex po sulphonic a id group quaternary ammonium groups ( . For s mplic ty, the polymers of these two types will be referred to hereafter as "sulphonic acid polymers" and "ammonium polymers", respectively.

A number of complex polyelectrolytes have already been described; they are obtained by forming an ionic crosslink between sulphonic acid polymers and the ammonium polymers. Most of the complex polyelectrolytes result from the reaction between sulphonic acid polymers and ammonium polymers, both the polymers being soluble in water. Complex polyelectrolytes can be prepared by mixing aqueous solutions of the two types of polymer. , In this connection, reference can be made to, for example, United States Patents Nos. 3,271,496, 3,467,604, 3,558,744, 3,565,973, 3,579,613 and 3,635,846.

French Patent 1¾. 2,144,922 describes a different class of polyelectrolyte which results from the reaction of a sulphonic acid polymer with an ammonium polymer, both of the polymers being insoluble in water. This class of polyelectrolyte, like the preceding ones, have been prepared by mixing the two types of polymer starting material.

In contrast to the previous procedures, it has now been found, according to the present invention, that complex polyelectrolytes derived from sulphonic ae*e-» polymers and ammonium polymers which are both insoluble in water can be prepared more simply by intimately mixing one of the polymer starting materials in the solid state, for example as a powder, with the other type of starting polymer, this other starting polymer either being in solution, preferably in solvent for the final complex polyelectrolyte, or being also in the solid state, in which case the two powders are placed in solution, preferably in a solvent for the complex polyelectrolyte it©" be formed.

The powders used in the process of the present invention generally have a particle size not exceeding 500 microns and preferably not exceeding 100 microns. The minimum size is, in practice, generally at least 5 microns and, more particularly, at least 20 microns. It is to be understood, however, that these lower limits are not absolutely critical but merely indicate the minimum particle sizes generally obtained by using conventional grinding machines.

The complex polyelectrolyte produced by the process of the present invention is insoluble in water and soluble in an organic medium and which corresponds to the general formula: in which tho symbol N ^ represents a quaternary ammonium nitrogen-containing group, the symbol represents a macromolecular chain carrying groups which are capable of being linked, via a covalent bond, to -SO^ ® groups, the symbol — — PI — \ I — I I — PI— represents a macromolecular chain carrying groups which can give rise to the formation of ® g„roups, the symbol indicating that the θ groups are linked to the macromolecular chain by at least one covalent bond, the chains and -Γΐ_π_π_π_π_, considered together, not containing oppositely charged groups which are capable of forming inter-chain covalent bonds, the ratio ~ is between 0,1 and 10 and the nature of the units forming the macromolecular chains as well as the values of the symbols n and m is such that a polymer of the formula (sulphonic-eecs€ polymer) in which the macromolecular chain is essentially the same i.e. has the same length and the same structure as that of symbol / ' ' ^ ^N ^n formula (I), and M represents a hydrogen ion or an alkali metal or alkaline earth metal ion and x is equal to 1 or 2, and a polymer of the formula JTjnJTJTJl lymer) in which the macromolecular chain is essentially the same as that of symbol -inj r!,. PI Π_ in formula (I), and A represents a hydroxyl radical or the anion of an inorganic or organic acid of the formula AHy, y being equal to 1, are both insoluble in water but soluble in one and the same liquid organic medium.

For simplicity, the part of the complex polyelectrolyt of the formula will be called "polyanion" and the part of the formula (I^)* -JTJTJIJIJ .

N m will be called "polycation" j In general terms, the presence of ionic groups in macromolecular chains increases the solubility of the polymers in water. Although the polymers of formula (I^) and (^2^ possess hydrophilic groups, they must, on the other hand, be insoluble in water. The insolubility in water can be achieved, firstly, by increasing the molecular weight of the polymer and, secondly, by limiting the number of hydrophilic groups linked to the macromolecular chains -TLrLrLTLn.- With regard to the molecular weight, in general terms, the specific viscosity of each of the polymers of formula (I^) and (I2) should generally be greater than 0.01; preferably, it is between 0.05 and 1.5 (measured at 25 °C. on a 2 g/litre solution in dimethylformamide). With regard to the number of hydrophilic groups, in general terms, in each of the polymers of formula ( ) and ( ∑2 ) , there should generally be less than 1 hydrophilic group per 12 carbon atoms and preferably less than 1 hydrophilic group per 20 carbon atoms. also contain a small proportion of hydrophilic groups other than these. These hydrophilic groups can be anionic groups, such as carboxylic acid groups, sulphate or acid sulphate groups, phosphonic acid groups, phosphate groups or sulphamic acid groupsj cationic groups, such as amine salts or compounds possessing a phosphonium or sulphonium group? and non-ionic groups, such as hydroxyl, ether, carboxylic ester or amide groups. When the polyanicn and polycation contain hydrophilic groups other than, respectively, -SO^ ® and N® groups, it is preferable that these additional groups are non-ionic or carry ionic groups of the same charge as the characteristic groups of the polymer. It would not, however, be outside the scope of the invention to use slightly ampholytic polymers, that is to say, a polyanion and/or a polycation containing, respectively, a small proportion of cationic and anionic groups. \ polycation are each less than 5%, In general terms, with regard both to the polyanion and to the polycation, the ratio number of hydrophilic groups other than -SO^ ^ or N ® number of -SO^ ^ or groups is less than 1, The macromolecular chains represented by the symbols of very different types.

More precisely, the sulphonic ac d polymer can be chosen from, for example, a) the polymerisation products of monomers at least a part of which are monomers carrying sulphonic -ae±€t-groupsj and β) the products obtained by sulphonating polymers obtained from monomers free from sulphonic ae^ groups.

The term "polymer" as used herein is to be understood in the wide sense and includes poly-addition products, obtained, for example, by opening carbon-carbon double bonds, as well as polycondensation products.

Amongst the polymers of group a), there may be mentioned, in particular, vinyl polymerisation products which can be defined as consisting essentially of a plurality of units of the formulae -CiR1 -CR1- 2 i R (II) , optionally, combined with units of the formula _CR2R3-C(R3)2- (III) in which the various R1 radicals, which may be identical or different, each represents hydrogen or an alkyl radical v/ith 1 to 4 carbon atoms.

R can represent* either a simple valency bond; or a wholly hydrocarbon divalent group, the free valencies of which are carried by a wholly aliphatic, saturated or unsaturated, straight or branched chain, or by an aromatic ring, or by a chain, one of the free valencies being carried by an aliphatic carbon atom and the other free valency by an aromatic carbon atom; or a -0-R1- or -S-R'- group, R1 representing a divalent group such as defined above for R; or a divalent group consisting of wholly hydrocarbon, aliphat: and/or aromatic groups, linked to one another by oxygen or sulphur atoms, the free valencies being carried by aliphatic and/or aromatic carbon atoms; ora divalent group such as defined above, one or more carbon atoms of which carry, in addition, substituents such as halogen atoms or hydroxyl radicals.

In formula (III), the various symbols R2 , which may be identical or different from one another and which may vary from one unit of formula (III) to another, each represents a hydrogen atom, a halogen atom or an alkyl radical with 1 to 4 ■a carbon atoms; each R radical, which may be identical or different, is as defined under R or represents a group choser from radicals of the formulae -C≡N,-OR5, - NHR5 in which R represents a hydrogen atom or a linear or branched alkyl radical containing 1 to 30 carbon atoms, a cycloalkyl radical containing 5 or 6 ring atoms, an aryl radical, an "~^ ^ alkoxyaryl radical or an aralkoxy radical.

By way of illustration, monomers which lead, on polymerisation, to units of formula (II), include the following acids (which may be in the form oft salts)s vinylsulphonic acid, 1-propene-l-sulphonic acid, allylsulphonic acid, methallylsulphonic acid, allyloxyethylsulphonic acid? l-butene~l-sulphonic acid, 2-butene-l-sulphonic acid and 3-butene-l-sulphonic acid; hexene-sulphonic acids, especially l-hexene-l-sulphonic acid? methylbutenesulphonic acids, methallyloxyethylsulphonic acid, 3-allyloxy-2-propanol~l- sulphonic acid, allylthioethylsulphonic acid and 3-allylthio-2-propanol-1-sulphonic acid; vinylbenzenesulphonic acids, especially 3-vinyl-l-benzenesulphonic acid; vinyloxybenzene- sulphonic acids, especially 2-vinyloxy-l-sulphonic acid and 4-vinyloxy-l-benzenesulphonic acidj isopropenylbenzenesulphonic acids, especially o-isopropenylbenzenesulphonic acid and p-isopropenylbenzenesulphonic acid; bromovinylbenzenesulphonic acids, especially 2~bromo-3~vinyl-l-benzenesulphonic acid and -bromo-3-vinyl-l-benzenesulphonic acidj a-methylstyrene-sulphonic acids, ct-ethylstyrenesulphonic acids and isopropenyl-cumenesulphonic acids; mono-, di- and tri-hydroxyvinyl-benzenesulphonic acids; 2,5~dichloro-l-vinylbenzenesulphonic acids, isopropenylnaphthalenesulphonic acids and vinyldichloro-naphthalenesulphonic acids? o and j-allylbenzenesulphonic acids and o- and g-methallylbenzenesulphonic acids? 4-(o~ and β-isopropenylphenyl )-l-n-butanesulphonic acids; vinylchlorophenylethanesulphonic acids; o and g-allyloxy- acrylamide and methacrylamide and the products of the reaction of the above-mentioned acids with a primary monoamine such as methylamine,. ethylamine, propylamine, cyclohexylamine and aniline.

As particular examples of polymers of group a), containing units of formulae (II) and (III) there may be mentioned the copolymers of acrylonxtrile with methallylsulphonic acid or its salts. In these copolymers, the proportion of units originating from the acid possessing a -SO3H group is generally between 1 and 30%, preferably between 4 and 20%, by weight based on the total weight of the copolymers„ It will be apparent from what has already been stated that some of the units of formula (III) can possess hydrophilic groups. It is to be understood that the amount of monomer carrying hydrophilic groups which is employed must be such that the specified proportion of these groups in the macromolecular chain is not exceeded. It is particularly easy to achieve this result by using a copolymer originating from several different monomers, a part at least of these monomers being free from hydrophilic groups.

Other examples of polymers of group a) are polycondensates originating from monomers of which some at least carry one or more -SO^H substituents. Particular example of such polycondensates are those comprising a plurality of units of the formulae: Q — † (V) in which Q3" represents the radical of a diacid of the formula HOOC - Ω1 - COOH. T1 represents the radical of a diol of the formula HO - T1 - OH and T2 represents the radical of a diamine of the formula H^T-T2-].^ , the radical represented by Q1 carrying a -S03H substituent.

By way of illustration, radicals represented y^jj 1 T1 and T2 may be straight chain or branched chain aliphatic radicals containing 3 to 10 carbon atoms, cycloaliphatic radicals v/ith 5 or 6 carbon atoms in the ring, monocyclic aromatic radicals which are unsubstituted or substituted by one or two alkyl radicals with 1 to 4 carbon atoms, or radicals consisting of several cycloaliphatic or aromatic radicals bonded directly to one another or via a divalent hydrocarbon radical containing 1 to 4 carbon atoms or via a hetero-atom such as oxygen, sulphur and nitrogen, or via a divalent group Examples of radicals represented by the symbol include, in particular, alkylene radicals containing 3 to 10 carbon atoms and phenylene radicals, these various radicals carrying a -SO^H substituent. Particular examples of diacids of formula HOOC-C^-COOH include sulphosuccinic acid and 5-sulpho-isophthalic acid.

It is to be understood that in the preparation of polycondensates of formula (IV) and (V) , and especially with a view to controlling the proportion of sulphonic acid groups in the polycondensate, the above-mentioned acid can be used in conjunction with other diacids, for example, aliphatic diacids such as succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, maleic and fumaric acids; cycloalkane-dicarboxylic acids, such as cyclohe ane-1, -dicarboxylic acidj and aromatic acids such as benzene-dicarboxylic acids.

As examples of diols, there may be mentioned 1; 2-ethanediol , 1,2- and 1, 3-propanediol , 1,2-, 1,3- and t4-butanediol, 1,5-pentanediol, 1 , 6-hexanediol , 1,10-decane-diol, 2 , 2-dimethyl-l , 3-propanediol and l,2-diethyl-l,3?T ^ propanediol; As examples of diamines, there may be mentioned ethylene—diamine, 1,2-diamino-propane, 2,2«bis-(4~amino— cyclohexyl )-propan , 1 , 6-diamino-hexane, metaphenylene-diamine; 2,3-, 2,7- and 3 , 6-diamiho-carbazoles and Ν,Ν'-bis-(carbonamidopropyl)-he¾ane-l, 6-diamine.

The polymers of group β) are obtained by attaching sulphonic acid groups to a macromolecular chain„ It is possible to attach such groups to polymers comprising recurring units of the formula: -C 1), - CR1- I RH —Q « , in which R, R1 , T1 and T2 are as defined above, and Q represents a radical as defined under Q1 but free from ^SO^H groups.

Other types of polymers which can be sulphonated are those containing a plurality of units of the formula: - AT - EJ (VI) in which each Ar radical, which can differ from one unit to another, represents a divalent aromatic radical or a divalent radical carrying at least one aromatic substituent, and each E radical, which can differ from one unit to another, represents a divalent group, namely -0-, -SO^- , -(CI^)v-, v being from 1 to k, or 2-.

Examples of aromatic radicals represented by Ar include phenylene radicalsa optionally substituted by one or two alkyl or aryl rad cals, n part cu ar p-p enylene an radicals of the formula: in which L represents an alkylene or al3¾\Lidene radical containing 1 to 12 carbon atoms or a -CO- group.

As examples of polymers containing chains of formula (VI), there may be mentioned, in particular, phenol polyethers, such as those described in United States Patent No. 3,306,875, and polymers containing a plurality of CE^-O-Ar -CH-j-C-CI-^-O- Clij-O-Ar unitse As polymers which can be sulphonated, polyaryl ether sulphones of the general formula. are preferably usedj such polymers are described in, for example French Patent No. 1,407,301.

The particular techniques for sulphonation have been described in the literature. In particular, Everet 3, GILBERT, in "Sulphonation and Related Reactions", 1965, Interscience Publishers, has extensively described means fo. attaching sulphonic acid (or sulphonate) groups to the most diverse organic groups.

Like the sulphonic acid polymer, the ammonium polymer can belong to one of two categories of polymerj it can, in effect, consists either of products obtained by treating a polymer ( a ' ) , of products obtained by reacting a tertiary amino with a polymer ( β ' ) carrying substituents which are capable of, quaternis ng the said amine, thereby bonding it to the -" polymer (β 1 ) „ The polymers of the group (α') can be, for example, a polymer containing a plurality of units of the formula. , optionally with a plurality of units of formula (III) (given above), R1 being as defined eibove and R6 representing a ~N(R >2 group or a monovalent hydrocarbon radical, chosen from linear or branched al yi radicals containing 1 to 12 carbon atoms, cycloallcyl radicals with 5 or 6 carbon atoms in the ring and phenyl radicals, these various radicals carrying a -N(R )2 substituent, or radicals consisting of a heterocyclic structure containing 1 or 2 nitrogen atoms with 5 or 6 ring members, optionally combined with 1 or 2 aromatic nitrogen rings, the/atom or at least one of the atoms of nitrogen in the heterocyclic structure being bonded by its three valencie to adjacent carbon atoms within the heterocyclic structure, o being bonded by two valencies to the said carbon atoms and 7 7 by the third to a -R group, each of the R radicals, which may be identical or different, representing an alkyl radical with 1 to 6 carbon atoms.

By way of illustration, monomers which lead, on polymerisation, to units of formula (VTI) include vinyl-dimethylamine, allyldimethylamine, 1-dimethylamino-l-propene, 2-dimethylamino-l-propene, l-dimethylamino~2-butene, 4—diroethylamino-l-butene, 3"dimet3yla-iu.no~l~b ene, 3-dimethylamino~2-methyl-»l-propene, methylethyl llylamine v ny e yamne, - me y mno- ~penene, - me y ani no- 3-methyl-l-butene, methylpropylallylamine, allyldiethylamino, 6~dimethylamino-l-hexene, ethylvinylbutylamine, allyldii^o.-propylamine, 3-dimethylamino~2-propyl~l-pentene, allyldibutyl- amine, diallcylaminostyrenes, in particular dimethylamino- styrene and diethylamino-styrone, vinylpyridines, in particular N-vinylpyridine, 2-vinyl-pyridine, 3-vinyl-pyridine and 4~vinyl-pyridine, and their substituted derivatives such as 5-methyl-2-vinyl-pyridine, 5-ethyl-2-vinyl-pyridine, 6-methyl-2-vinyl-pyridine, 4,6-dimethyl-2-vinyl-pyridine, 6-methyl~3~ vinyl-pyridine, K^-vinylcarbazole, 4-vinyl-pyriiaidine and 2-vinyl-ben2imidazole.

Specific examples of polymers of group (a1) containing units of formulae (VII) and (III) are the copolymers of acrylonitrile and a vinylpyridine. In these copolymers, the proportion of units originating from the amine-type monomer is generally between 1 and 50%, preferably between 4 and 30%, by weight relative to the total weight of the copolymer* The polymers of group (α') can also consist of condensation products of monomers at least a part of which contains tertiary nitrogen atoms. Such polycondensates can contain a plurality of units of formula (VIII) or (IX) in which Q represents the radical of a diacid of the formul H00C-Q2-C00H, T3 represents the radical of a diol of the formula HO-T^-OH and T4 represents the radical of a diamine of the formula Η2Η-Τ4-13Η2, at least one of the radicals Q2 and T3 and T4 containing a tertiary nitrogen atom.

It is to be understood that, in the case where the polycondensate contains units of formula VIII , it can consist of these units alone (polyester) or it can contain tirethane or urea groups. In the latter cases, the poly e^ will consist of a chain comprising rows of units of formula (VIII) bonded to other rows of units of formula (VIII) via groups (ISO representing the radical of a diisocyanate of th formula 0=C= -ISO~N=C=0 ) and, where appropriate, via groups, R representing a valency bond or a group chosen frcrr. 4 amongst the groups of the formula: ~0~, -NK-NH-, -HN-T -Ο-Ί^-Ο- and -KH-IMH-CO-m-, 2 In general terms, when Q represents the radical of diacid containing a tertiary nitrogen atom, it is an alkylene radical containing two to 12 carbon atoms, substituted by a dialkylamino radical or interrupted by an alkylimino radical j a cycloalkylene or arylene radical substituted by a dialkylamino radical, or two of these rings connected by an alkylimino radical; or a nitrogen-containing heterocyclic structure with 5 or 6 ring members, containing 1 or 2 nitrogen atoms, this atom or one of them being bonded by its three valencies to neighbouring carbon atoms or by two valencies to neighbouring carbon atoms and by the third to an alkyl radical of 1 to 4 carbon atoms, 4 When T represents the radical of a diamine with a tertiary nitrogen, it can be chosen from amongst the radicals represented by Q 2, diol possessing a tertiary; nitrogen atom, it is a linear or v branched, aliphatic, hydrocarbon radical containing 2 to 12 carbon atoms, which may be saturated or which may possess^ ethylonic or acetylenic unsaturation, substituted only, or at least, by one dialkylamino radical or interrupted by an alkylimino radical.

Examples of suitable diacids possessing a tertiary nitrogen atom include, in particular, methylimino-diacetic acid, 3-dimethylamino-he ane-dioic acid, 1-dimethylamino- cyclopentane-2,3-dicarboxylic acidt dimethylaminoiso- phthalic acid, dimethylaminoterophthalic acid, 1-methyl- pyrimidine-dicarboxylic acid and l~raethyl-imidazolo-4,5- dicarboxylic acid.

. Examples of suitable diols possessing a tertiary nitrogen atom include, in particular, alkylamines substituted on the nitrogen atom by two hydroxyalkyl"radicals, "such as' ethyidiethanolamine or alkylene glycols substituted by a dialkylamino 'group on a non-hydrc-xylic carbon atom, such as γ-dimethylamino-propylene glycol and γ-diothylamino-propylene glycol, ... ·.. ,_. ·-..·-. ...·.. ,...·.. ·.>■-■ 'Examples 'of suitable diamines containing a tertiary nitrogen atom include 3-dimethylamino-hexane~l,6-diamine, 3-( -methyl-piperazinc> )-hexane-i, 6-diamihe, 3-pyrrblidino-hoxane-l, 6-diamine, 3-piperidino-hexarie-l,6-diarnine," 3-morpholino-hexane-l, 6-diamine, N-bis-(3-aminopropyl )-methylamine, N^bis-(3-aminopropyl )-cyclohe ylamine and ίΐ-bis-(3-amino-propyl )-aniline.

The diacids, diols and diamines which do not contain tertiary nitrogen atoms and which can take part in the preparation of the polycondensates of formula (VIII) and (IX) , diamines mentioned above, " Examples of diisocyanates of the formula 0=O=N-IS0-K=C=0 which can be used for the preparation of polycondensates of the polyurethane type, include 1,6-diiso- cyanato-hexanc, 2,4-diisocyanato-toluene, 2 ,6-diisocyanato- toluene, meta-diisocyanato~ben2ene, 2,2-bis-(4-isocyanato-cyclohexyl)~propane, bis-(4«-isocyanato-cyclohexyl)-methane, 1,5-diisocyanato-pentane, 1,4-diisocyanato-cyclohexane and bis-(4—isocyanato-phenyl )-methane.

As examples of compounds which can be used in association with these isocyanates in order to obtain -0-CO-NH-ISO-NH-CO-R8~CO-NH-1SO-NH-CO-0-T3-groups, there may be mentioned water, hydrazine and aminoacet hydrazide as well as the diols and diamines, with or without a tertiary nitrogen atom, mentioned above.

As particular examples of polycondensates containing tertiary nitrogen groups, there may be mentioned polyester-urethanes obtained from a diol containing a tertiary nitrogen atom, such as ethyldiethanolamine, from adipic acid and from a diisocyanate such as 4,4'-diisocyanato-diphenyl-methane, the coupling agent optionally used being a diol or amino-acety hydrazide. In these polymers, the molecular v/eight of the intermediate polyester is generally between 300 and 10,000.

The quaternising agents for tertiary amine groups as well as the conditions employed have been described in the literature. In general terms, esters of inorganic acids such as halides and alkyl sulphates, cycloalkyl sulphates and aralkyl sulphates are used. The alkyl, cycloalkyl and aralkyi radicals preferably contain, at most, 14 carbon atoms. •Exampl of such quaternising agents include methyl, ethyl, propyl, cyclohexyl and benzyl chlorides, bromides and iodides, and dimethyl and diethyl sulphates. It is also possible to u1¾^ halogenated derivatives containing other chemical groups sucl. as chloroacetaldehyde.

The substituents of the polymers of group ( β 1 ) whic are capable of reacting v/ith a tertiary amine to give quaternary ammonium groups are generally halogen atoms* The polymers of group (β') can thus be defined as containing a plurality of units of formula (X): in which Δ represents an organic radical containing a halogen substituent and E is as defined above. It is to be understoc that the polymers of group (β1) can contain, combined with t units of formula (X) , units which are free from halogenated groups.

The presence of halogenated groups in the polymers of group (β') can be achieved by polymerising monomers containing such groups. Examples of this type include homo-and copolymers of 2-chloroethyl methacrylate.

More generally, the halogenated polymers can be obtained by attaching halogenated groups to macromolocular chains which are free from such groups. The techniques for attaching halogenated groups to polymers are well known.

Amongst those most frequently used, there may be mentioned halomethylation, in particular chloromethylation, of polymers containing aromatic groups, such as the polymers of formula (VI) and the treatment, by means of epihalohydrinc in particular epichlorohyd in, of polymers containing polymers are poly(hydroxy-ethers) consisting of a plurality o. units of th in which the symbol ε represents a divalent radical of the formula: Typical tertiary amines which can react with the halogenated polymers described above include trialkylamines possessing unsubstituted alkyl radicals such as trimethylamine , ty¾Qcylainino t 4uciethylamine and tripropylamine, trialkylamines in which at least one of the a kyl radicals is substituted by a functional group, such as the N-dialkylalkanolamines, the N-alkyldialkanolamines and the trialkanolamines, for exam J^^ dimethylethanolamine and triethanolaminej heterocyclic amines such as pyridine, the picolines, the lutidines, the N-alkyl-piperidines and the N, N'-dialkylpiperazinesj quinoxaline and the N-alkylmorpholinesj and juxtanuclear aromatic amines such as NjN'-dimethylaniline or extranuclear aromatic amines. Generally, the amines used have 3 to 12 carbon atoms.

Amongst the above-mentioned poly(hydroxy-ethers) , the polymers possessing the following recurring unit: are preferredβ These poly(hydroxy-ethers) are preferably treated with epichlorohydrin, the amount of the latter reagent being such that the ratio number of mo s of epichlorohyd in number of OH groups of the polymer is suitably between 0.2 and 5, In the preparation of the complex polyelectrolytes according to this invention, one uses, as indicated above, a solvent for the polymer starting materials which is preferably also a solvent for the complex polyelectrolyte. This solvent is preferably organic and can consist of a single solvent or of a mixture of solvents.

The choice of solvent obviously depends on the nature of the various polymers in question. In general however, various polymers mentioned above are soluble in aprotic polar solvents, such as dimethylformamide, dimethylacetamide, dimethylsulphoxide , hexamethylphosphotriamide, 2-N-methyl-pyrrolidone, sulpholane and ethylene carbonate. It is of course possible to use mixtures of these solvents with one another and/or with other organic solvents such as ketones and esters.

In the case where one uses a mixture of one type of polymer in powder form with a solution of the other type of polymer, the initial concentration of this solution influences the physical appearance of the complex polyelectrolyte obtained. In general terms, with a view to obtaining continuity in the ionically cross-linked polymer, the concentration of polymer in the initial solution should be greater than 0.25% and preferably greater than 0.5% (by weight). The upper concentration limit is determined essentially by technological demands. In general terms this limit is of the order of 25%, but this is not critical.

The preparation of this solution of the polymer starting material can be carried out in accordance with the techniques generally employed for the preparation of polymer solutions. Usually, in a first stage, the polymer is dispersed in the solvent maintained at a relatively low temperature, for example -20° to +'.2G-¾; thereafter, the temperature is gradually increased until a limpid and homogeneous solution is obtained. The final temperature depends on the nature of the polymer and of the" solvent. It is generally between 20° and 100°C.

In the case where one starts from a solution obtained by adding to the solvent powders of the two polymer starting materials, the relative proportions of the solid material relative to the total amount of solid and solvent are roughly the same as indicated above. That is to say, the concentration of polymers dissolved in the solvent should generally be greater than 0.5% and preferably greater than 1%, the upper limit being of the order of 50%, without this being a critical upper limit.

The way in which this solution is obtained is essentially the same as that indicated above when one of the polymers is dissolved in the solvent.

As is apparent from the value of the ratio ~ given above, one or the other of the sulphonic acid polymer and the ammonium polymer can be present in excess, as regards the number of ionic groups, in the reaction mixture. Preferably, the ratio m— is between 0.2 and 5.

The formation of the complex polyelectrolyte in the mixture manifests itself in a rapid increase in viscosity of the solution, as soon as the two reactants and the solvent are brought into contact. The introduction into this new solution (of complex polyelectrolyte) of a strongly ionised electrolyte, comparable to the "ionic shields" described in the prior art, causes a considerable decrease in the viscosity, which demonstrates, according to generally accepted interpretations, ttiat this electrolyte has broken, at least partially, the ionic bonds formed between the sulphonic acid polymer and the ammonium polymer.

The solution of the polyelectrolyte can be used directly for the production of films or shaped articles. It sometimes happens , especially if it is desired to prepare a membrane by casting a complex polyelectrolyte solution, that the viscosity of the solution obtained from the reaction medium is too high.

It is then sufficient to dilute this solution in order to obtain the desired viscosity. jj^ It is apparent from what has been said above that the use of an ionic shielding solvent is by no means indispensable in using the complex polyelectrolytes prepared by the process of this invention. It is evident, nevertheless, that the use of a strongly ionised electrolytef which is soluble in an organic medium, such as lithium chloride, in order to decrease the viscosity of the complex polyelectrolyte solution, does not fall outside the scope of this invention.

The films and membranes obtained from solutions of the complex polyelectrolytes prepared by the process of this invention can be planar, tubular, spiral or of any other shape; they can have an isotropic or anisotropic structure. By membranes with an "isotropic" structure is meant a membrane v/hich has a dense structure or a uniform porosity throughout its entire thickness; by an "anisotropic" membrane is generally meant a membrane which has a porosity gradient from one face to the other, it being possible, in the limiting situation, for one of the faces to be completely fose from pores.

The isotropic membranes can generally be obtained by simply casting the complex polyelectrolyte solution on a suitable surface (such as a glass plate or a metal plate, tube, spiral or tape) and then removing the solvent. The anisotropic membranes can be obtained by immersing the plate supporting the layer of complex polyelectrolyte solution in a coagulation bath non-solvent for the complex polyelectrolute. Generally, the coagulation bath consists of water, or of mixtures of water and organic liquids or of aqueous solutions of electrolytes.

It is to be understood that the complex poly-electrolytes prepared according to the invention can contain fillers and/or plasticisers , which can be mixed directly with the complex polyelectrolyte in solution or to have incorporated them previously in the polymer and/or the initial ammonium polymer. Likewise, the membranes can consist of the filled or unfilled complex polyelectrolyte film alone, or they can contain a reinforcement such as a woven fabric, a knitted fabric or a net based on natural or synthetic fibres.

The complex polyelectrolytes prepared according to this invention can be used in a number of ways; they can be used in the textile field, in the form of yarns, fabrics or of treatment compositions for yarns or fabrics, intended to provide certain properties such as dyeing affinity, and hydrophilic and anti-stetic character; these various desired properties can be adjusted as a function of the anionic or cationic excess in the complex polyelectrolyte.

The membranes can be used especially for the fractionation of solutions using ultrafiltration, ¾p?verse osmosis and dialysis techniques. These membranes, in particular when they are anisotropic, have in effect a high specific degree of rejection towards macromolecular species whilst having a high permeability towards water. It should be noted that a heat treatment in water makes it possible to change the structure of the membrane and to vary its stoppage zone (limit of molecular weight of the compounds which pass through the membrane) from a high value (for example 10 to 15,000) to a very low value (of the order of 2 to 300). These membranes combine good mechanical qualities with their permeation properties , and this makes it possible for them to withstand pressures in use without being damaged, for example in ultrafiltration.

The films of complex polyelectrolytes prepared by the process of this invention can also be used as battery dividers.

The complex polyelectrolytes can also be used in medical applications, especially in artificial kidneys and lungs because of the dialysis and gas permeation properties of the membranes prepared from these polyelectrolytes and, more generally, in the manufacture of prostheses and any article which must be brought into contact with blood, because these polyelectrolytes possess noteworthy antithrombogenic properties .

The complex polyelectrolytes prepared by the process of this invention can also be used as artificial leathers or in the production of coatings which conduct electricity or of antistatic coatings. It will be appreciated, however, that these applications are illustrative only.

The following Examples further illustrate the present invention. Temperatures are given in degrees Centigrade.

Example 1 3 In a 250 cm vessel equipped with a stirrer the following materials were added, either separately to form a solution on stirring, or together in the form of a solution already formed: 19.6 g of a powder of an acrylonitrile/sodium mi1li¾uivalents methallylsulphonate copolymer (0.600 equivalent-., per gram of sulphonate groups; particle size: between 50 and 80 microns; specific viscosity, measured at 25°C. as a 2 g/litre solution in dimethylformamide: 0.87).

A mixture of 163.4 cm of dimethylformamide and 3 8.6 cm of water.

The solution was cooled to 0°C. and to it was added 8.4 g of a powder of a copolymer of acrylonitrile and 2-methyl-5-vinylpyridine (containing 0.564 milliequivalents per gram of tertiary amino groups) quaternised with excess methyl sulphate and having, after this quaternisation, a specific viscosity (measured at 25°C. as a 2 g/litre solution in dimethylformamide) of 1.61 and a particle size between 50 and 80 microns. The mixture was stirred at 0°C. for one hour and this enabled a uniform dispersion of the powdered copolymer to be obtained in the solution.

The temperature of the mixture was then raised to 20°C. , stirred for one hour and then kept at 65 °C. for 3 hours, with stirring. A clear solution was thus obtained.

This solution was cast on a glass plate to provide a liquid film 0.25 mm thick. The assembly was then immersed in a water bath at 20°C. to coagulate the film. After removing the solvent by washing in water, a membrane was obtained which could be used for ultrafiltration. Under a pressure of 2 bars, an aqueous solution containing 1 g/litre of lysozyme (molecular, weight 15,000) and 5.85 g/litre of sodium chloride was stirred in contact with the surface of the membrane with the aid of a magnetic stirrer. A permeate was obtained in an amount of 5,400 litres/day/square metre, the degree of rejection of the lysozyme being greater than 90%.

Example 2 In a beater equipped with a rotating blade the following materials were charged: 19.6 g of a powder of a copolymer of acrylonitrile and sodium methallyl sulphonate identical to that used in Example 1 : 8.4 g of a powder of a quaternised copolymer identical to that used in Example 1. .

Once the mixture of the two powders was intimate, i.e. once a homogeneous powder was obtained such that to the naked eye one could not distinguish either of the constituents, 3 to it was added at 0°C. a mixture of 163.4 cm of dimethyl- 3 formamide and 8.6cm of water. The mixture was stirred for one hour at 0°C. , for one hour at 20°C. and for 3 hours at 65°C. A clear solution was thus obtained having a viscosity, measured at 25°C. , of 272 poises.

An ultrafiltration membrane was prepared from this solution under the conditions described in Example 1. This membrane possessed a debit of pure water, under 2 bars, of 4,880 litres/day/square metre.

Example 3 In a beater equipped with a rotating blade, was charged: 10 g of a powder of a copolymer of acrylonitrile and sodium methallyl sulphonate (0.570 milliequivalents per gram of sulphonate groups; particle size: between 50 and 80 microns; specific viscosity, measured at 25°C. as a 2 g/litre solution in dimethylformamide: 1.03); 10 g of a powder of a copolymer of acrylonitrile and 2-methyl-5-vinylpyridine (containing 0.570 milliequivalents^, per gram of tertiary amine groups) quaternised with excess methyl sulphate and having, after quaternisation, a specific viscosity, measured as indicated above-, of 1.391 and a particle size between 50 and 80 microns j 0.121 g of lithium chloride.

An intimate mixture of the powders was obtained as described in Example 2 and then to this was added, at 0°C. , 105 cm of dimethylformamide. The mixture was stirred for one hour at 20°C. and then for 3 hours at 65°C. A clear solution was thus obtained having a viscosity, measured at 25°C. , of 445 poises (equivalent to the viscosity of the solution obtained on mixing individual solutions of the polymer starting materials under analogous conditions).

Claims (20)

WE CLAIM I

1. Process for preparing a complex polyelectrolyte from two types of polymer, one type possessing sulphonic ■aoid groups and the othiar possessing quaternary amronium groups, said polymers beting insoluble in water, which process comprises mixing one tyj>e of polymer in the powdered state with the other type of jxalymer, said other type of polymer being either in solution or in the powdered state, in which latter case the mixture of the two powders is put into solution.

2. ·' Process according to claim 1 in which the complex polyelectrolyte is one which is insoluble in water and soluble in a liquid organic medium and which corresponds to the general formula t in which: a the symbol N represents a quaternary nitrogen-containing ^ group? the symbol represents a macromolecular chain carrying groups which are capable of being linked, via a covalent bond, to -SO^ -groups, the symbol — ί L— I I Π I (__] represents a macromolecular chain carrying groups which can give rise to the formation of N Θ groups, the symbol indicating that the N Θ groups are linked to the macromolecular chain by at least ono covalent bond, and the chains ^ ^^"^^^^^^^ and , considered together, do not contain oppositely charged groups v/hich are capable of forming interchain covalent bonds, the ratio — is between 0.1 and 10: and m the nature of the units forming the macromolecular chains and the values of n and m being such that a polymer of formula (I. ) polyma:) in which represents a hydrogen ion or an alkali raetal or alkaline earth metal ion and x is 1 or 2, and a polymer of formula (I ) in which A repre inorganic or org 1, 2 or 3, are b common liquid or

3. Proces viscosity of eac is at least 0.01 dimethy1formami

4. Proce viscosity of each of the polymers of formula (I.,) and (I2) is from 0.05 to 1.5, measured at 25°C. as a 2 g/litre solution in dimethylformamide.

5. Process according to any one of claims 2 to 4, in which each of the polymers of formula and (I2) contains less than one hydrophilic group per 12 carbon atoms.

6. Process according to claim 5 in which each of the polymers of formula (Ι¾) and (I2) contains less than one hydrophilic group per 20 carbon atoms.

7. Process according to any one of claims 2 to 6, in which the polymer of formula (I-) is a polymerisation product of monomers at least a part of which are monomers containing sulphonic acid groups or a product obtained by sulphonating ^ a polymer obtained from monomers which do not possess sulphonic aoid-groups , and the polymer of formula (jL^) is a product obtained by treating a polymer containing tertiary amino groups with a quaternising agent or a product obtained by reacting a tertiary amine with a polymer containing substituents capable of quaternising said amine, thereby forming a bond with said polymer.

8. Process according to any one of the preceding claims in which the powder has a particle size not exceeding 500 microns.

9. Process according to claim 8 in which the powder has a particle size from 20 to 100 microns.

10. Process according to any one of the preceding claims in which the solvent used to form the solution is a sdvent for the final complex polyelectrolyte.

11. Process according to claim 10 in which the solvent is an organic solvent or a mixture of organic solvents.

12. Process according to any one of the preceding claims in which a powder of the first type of polymer is used with a solution of the second type of polymer, the concentration of the second type of polymer in the solution being at least 0.25% by weight.

13. Process according to claim 12 in which the concentration of the second type of polymer is at least O.Jp% by weight and the concentration of the polymers dissolved in the solution is less than 50% by weight.

14. Process according to any one of claims 1 to 11 in which a solution is obtained from powders of the two types of polymer, the concentration of the polymers in the solution being at least 0.5% by weight.

15. Process according to claim 14 in which the concentration of the polymers in the solution is from 1 to 50% by weight.

16. Process according to any one of the preceding claims in which the solutions are obtained by dispersing the or each powder in the liquid phase maintained at a temperature from -20° to +20°C. and then raising the temperature progressively to a temperature from 20° to 100°C. until a clear andhomogeneous solution is obtained.

17. Process according to claim 1 substantially as hereinbefore described.

18. Process according to claim 1 substantially as described in any one of Examples 1 to 3.

19. A complex polyelectrolyte as defined in claim 1 whenever prepared by a process as claimed in any one of the preceding claims. ■r

20. A complex polyelectrolyte according to claim 19 in the form of an isotropic or anisotropic membrane. Attorney or ppicants