Polythiophenes, process for their preparation and their use

The invention relates to new polythiophenes containing structural units of the formula ##STR1## in which A denotes an optionally substituted C.sub.1 -C.sub.4 -alkylene radical, their preparation by oxidative polymerization of the corresponding thiophenes and the use of the polythiophenes for imparting antistatic properties on substrates which only conduct electrical current poorly or not at all, in particular on plastic mouldings, and as electrode material for rechargeable batteries.

The invention relates to new polythiophenes of high electrical 
conductivity, their preparation by oxidative polymerization of the 
corresponding thiophenes, and the use of the polythiophenes for imparting 
antistatic properties on substrates which only conduct electrical current 
poorly or not at all, in particular on plastic mouldings, and as electrode 
material for rechargeable batteries. 
Polythiophenes, their preparation by electrochemical or chemical oxidation 
of the corresponding thiophenes, and the use of the polythiophenes for 
imparting antistatic properties on substrates which only conduct 
electrical current poorly or not at all are known; see, for example: 
(a) EP-A-0,206,133; 
This discloses a process for applying coatings of conductive, polymeric 
heterocyclic compounds produced with the aid of oxidants onto substrates 
which conduct electrical current only poorly or not at all. However, only 
the imparting of antistatic properties on substrates by means of 
polypyrrole produced on the substrates by oxidative polymerization of 
pyrrole is described; 
(b) EP-A-0,253,594; 
This publication describes specific thiophenes substituted in the 3- and/or 
4-position by (substituted) alkyl and/or alkoxy groups and the 
electroconductive polymers obtained from them by chemical or 
electrochemical oxidation. According to the data given in the publication, 
the polythiophenes obtained by chemical oxidation only have poor 
conductivity; 
(c) U.S. Pat. No. 4,521,589; 
This publication describes the preperation of polymeric 3-alkylthiophenes 
by reacting 3-alkyl-2,5-dihalogeno-thiophenes with magnesium in the 
presence of nickel compounds in inert organic solvents. The 
electroconductivity of the undoped polythiophenes obtained in this way is 
given as being 9.times.10.sup.-14 S/cm; 
(d) EP-A-0,203,438 and EP-A-0,257,573; 
Both publications concern the preparation of substituted conductive 
polythiophenes which are soluble in organic solvents, and the use of the 
solutions of these soluble polythiophenes for imparting antistatic 
properties on substrates which only conduct electrical current poorly or 
not at all. The preparation of the soluble, substituted, conductive 
polythiophenes or solutions thereof is carried out by electrochemical 
oxidation of the corresponding substituted thiophenes (EP-A 257,573) or by 
reacting the corresponding 2,5-dihalogenothiophenes with magnesium in the 
presence of nickel catalysts (EP-A 203,438); the last-mentioned process is 
virtually impossible to carry out on an industrial scale, and the 
polythiophenes obtained by electrochemical oxidation only have very low 
conductivity. 
Surprisingly, it has been found that a specific type of 3,4-disubstituted 
polythiophenes is particularly suitable for imparting antistatic 
properties on substrates which only conduct electrical current poorly or 
not at all, since it has a high electroconductivity and since, in 
addition, it can be prepared directly on the substrates to be provided 
with antistatic properties by chemical oxidation of the parent 
3,4-disubstituted thiophenes using customary oxidants. This is because it 
has been found that the polymerization rates of the specific thiophenes 
can be varied through the choice of oxidant and, in particular, can be 
adjusted so that it is no longer necessary to apply the oxidant and 
substituted thiophenes separately to the substrate to be provided with 
antistatic properties, as has hitherto been necessary in the case of 
provision of antistatic properties using polypyrrole, but instead so that 
it is possible to apply the substituted thiophenes and oxidants to the 
substrates to be treated in combined form together in a solution of 
printing paste. 
The invention therefore relates to polythiophenes containing structural 
units of the formula 
##STR2## 
in which A denotes an optionally substituted C.sub.1 -C.sub.4 -alkylene 
radical, preferably an optionally alkyl-substituted methylene radical, an 
optionally C.sub.1 -C.sub.12 -alkyl- or phenyl-substituted 1,2-ethylene 
radical or a 1,2-cyclohexylene radical. 
The polythiophenes are preferably built up from structural units of formula 
(I). 
Representatives of the optionally substituted C.sub.1 -C.sub.4 -alkylene 
radicals which may be mentioned are preferably the 1,2-alkylene radicals 
which are derived from 1,2-dibromo-alkanes, as can be obtained on 
bromination of .alpha.-olefins, such as ethene, 1-propene, 1-hexene, 
1-octene, 1-decene, 1-dodecene and styrene; in addition, the 
1,2-cyclohexylene, 2,3-butylene, 2,3-dimethylene-2,3-butylene and 
2,3-pentylene radical may be mentioned. Preferred radicals are the 
methylene, 1,2-ethylene and 1,2-propylene radical. 
The invention furthermore relates to a process for the preparation of these 
polythiophenes; the process is characterized in that 3,4-disubstituted 
thiophenes of the formula 
##STR3## 
in which A has the meaning indicated under formula (I), are polymerized in 
an organic solvent which is inert under the reaction conditions used 
either by using oxidants which are suitable for oxidative polymerization 
of pyrrole or electrochemically. 
The oxidative polymerization by chemical means is surprising inasmuch as 
EP-A-0,206,133 describes pyrrole and thiophene as monomers which can be 
oxidized in the same way, but it has been shown that thiophene cannot be 
polymerized by oxidants which are suitable for oxidative polymerization of 
pyrrole, for example FeCl.sub.3. 
The polythiophenes according to the invention built up from structural 
units of the formula (I) are excellently suitable for imparting antistatic 
properties on substrates which only conduct electrical current poorly or 
not at all. The polythiophenes according to the invention are preferably 
produced directly on the substrates to be provided with antistatic 
properties, by the abovementioned preparation process. 
The invention therefore furthermore relates to a process for imparting 
antistatic properties on substrates which only conduct electrical current 
poorly or not at all, in particular on plastic mouldings, by applying a 
coating of electroconductive organic polymer onto the surface of the 
substrates; the process is characterized in that a coating of 
polythiophenes built up from structural units of the formula 
##STR4## 
in which A denotes an optionally substituted C.sub.1 -C.sub.4 -alkylene 
radical, preferablly an optionally alkyl-substituted methylene radical, an 
optionally C.sub.1 -C.sub.12 -alkyl- or phenyl-substituted 1,2-ethylene 
radical or a 1,2-cyclohexylene radical, 
is produced on the surface of the substrates by oxidative polymerization. 
The 3,4-disubstituted thiophenes of the formula (II) which are necessary 
for the preparation are either known or can be obtained by processes known 
in principle by reacting the alkali metal salts of 
3,4-dihydroxythiophene-2,5-dicarboxylic esters with the appropriate 
alkylene vic-dihalides and subsequently decarboxylating the free 
3,4-(alkylene-vic-dioxy-)thiophene-2,5-dicarboxylic acids (see, for 
example, Tetrahedron 1967 Vol. 23, 2437-2441 and J. Am. Chem. Soc. 67 
(1945) 2217-2218). 
The oxidative polymerization of the 3,4-disubstituted thiophenes of the 
formula (II) by chemical oxidation is generally carried out at 
temperatures from -10.degree. to +250.degree. C., preferably at 
temperatures from 0.degree. to 200.degree. C., depending on the oxidant 
used and on the reaction time desired. 
Particular examples which may be mentioned of organic solvents which are 
inert under the reaction conditions are: aliphatic alcohols, such as 
methanol, ethanol and propanol; aliphatic ketones, such as acetone and 
methyl ethyl ketone; aliphatic carboxylic esters, such as ethyl acetate 
and butyl acetate; aromatic hydrocarbons such as toluene and xylene; 
aliphatic hydrocarbons, such as hexane, heptane and cyclohexane; 
chlorinated hydrocarbons, such as dichloromethane and dichloroethane; 
aliphatic nitriles, such as acetonitrile; aliphatic sulphoxides and 
sulphones, such as dimethyl sulphoxide and sulpholane; aliphatic 
carboxamides, such as methylacetamide and dimethylformamide; aliphatic and 
araliphatic ethers, such as diethyl ether and anisole. In addition, water 
or mixtures of water with the abovementioned organic solvents can also be 
used as solvents. 
The oxidants used are the oxidants suitable for oxidative polymerization of 
pyrrole; these are described, for example, in J. Am. Chem. Soc. 85, 454 
(1963). For practical reasons, oxidants which are inexpensive and easy to 
handle, such as iron(III) salts, such as FeCl.sub.3, Fe(ClO.sub.4) and the 
iron(III) salts of organic acids and of inorganic acids containing organic 
radicals, furthermore H.sub.2 O.sub.2, K.sub.2 Cr.sub.2 O.sub.7, alkali 
metal persulphates, ammonium persulphates, alkali metal perborates and 
potassium permanganate, are preferred. 
Theoretically 2.25 equivalents of oxidant are required per mole of 
thiophene for the oxidative polymerization of the thiophenes of the 
formula II. (See, for example, J. Polym. Sci. Part A Polymer Chemistry 
Vol. 26, page 1287 (1988)). In practice, however, the oxidant is applied 
in a certain excess, e.g. an excess of 0.1 to 2 equivalents per mole of 
thiophene. 
The use of persulphates and iron(III) salts of organic acids and of 
inorganic acids containing organic radicals has the great applicational 
advantage that they are non-corrosive and, in particular, that, when they 
are used, the oxidation of the 3,4-disubstituted thiophenes of the formula 
(II) proceeds so slowly that the thiophenes and oxidants can be applied 
together from one solution or one printing paste onto the substrate to be 
provided with antistatic properties. After application of the solution or 
the paste, the oxidation is accelerated by warming the coated substrate. 
When the other abovementioned oxidants such as FeCl.sub.3, H.sub.2 O.sub.2 
or perborates are used, the oxidative polymerization proceeds so rapidly 
that it is necessary to apply the oxidants and thiophenes separately to 
the substrate to be treated, but, in contrast, warming is no longer 
necessary. 
Examples which may be mentioned of iron(III) salts of inorganic acids 
containing organic radicals are the iron(III) salts of the sulphuric acid 
monoesters of C.sub.1 -C.sub.20 -alkanols, for example the Fe(III) salt of 
lauryl sulphate. 
Examples which may be mentioned of iron(III) salts of organic acids are: 
the Fe(III) salts of C.sub.1 -C.sub.20 -alkylsulphonic acids, such as of 
methane- and dodecanesulphonic acid; of aliphatic C.sub.1 -C.sub.20 
-carboxylic acids, such as of 2-ethylhexylcarboxylic acids; of aliphatic 
perfluorocarboxylic acids, such as of trifluoroacetic acid and of 
perfluorooctanoic acid; of aliphatic dicarboxylic acids, such as of oxalic 
acid and, in particular, of aromatic sulphonic acids, optionally 
substituted by C.sub.1 -C.sub.20 -alkyl groups, such as of 
benzenesulphonic acid, p-toluenesulphonic acid and of 
dodecylbenzenesulphonic acid. 
It is also possible to apply mixtures of these abovementioned Fe(III) salts 
of organic acids. 
If thiophene and oxidant are applied separately, the substrate to be 
provided with antistatic properties may be treated firstly with the 
solution of thiophene and then with the solution of the oxidant or firstly 
with the solution of the oxidant and then with the solution of thiophene. 
If thiophene and the oxidant are applied together, the substrate to be 
treated is only coated with one solution containing thiophene and oxidant. 
Since a portion of the thiophene evaporates during this joint application 
the oxidant is added to the solutions in an amount which is reduced in 
accordance with the anticipated loss of thiophene. 
In addition, the solutions may contain organic binders which are soluble in 
organic solvents, such as poly(vinyl acetate), polycarbonate, poly(vinyl 
butyrate), polyacrylates, polymethacrylates, polystyrene, 
polyacrylonitrile, poly(vinyl chloride), polybutadiene, polyisoprene, 
polyethers, polyesters, silicones and pyrrole/acrylate, vinyl 
acetate/acrylate and ethylene/vinyl acetate copolymers which are soluble 
in organic solvents. It is also possible to use water-soluble binders, 
such as poly(vinyl alcohols) as thickeners. 
The solutions to be applied to the substrates to be treated preferably 
contain 1 to 30% by weight of the thiophene derivative of the formula (II) 
and 0 to 30% by weight of binder, both percentages by weight relating to 
the total weight of the solution. 
The solutions are applied to the substrates by known processes, for example 
by spraying, knife coating, brushing or printing. 
Specific examples of substrates which may be provided with antistatic or 
electroconductive properties by the process according to the invention are 
mouldings made from organic plastics, in particular films made from 
polycarbonates, polyamides, polyethylenes, polypropylenes, poly(vinyl 
chloride) and polyesters, but it is also possible to provide inorganic 
materials, for example ceramics, such as aluminum oxide, silicon dioxide 
and glass, with antistatic properties by the process according to the 
invention. 
The coating thickness of the applied coating after drying is generally 0.1 
to 100 .mu.m, depending on the conductivity desired and on the coating 
transparency desired. 
Removal of the solvents after application of the solutions can be effected 
by simple evaporation at room temperature. In order to achieve higher 
processing rates, however, it is more advantageous to remove the solvents 
at elevated temperature, for example at temperatures from 20.degree. up to 
250.degree. C., preferably 40.degree. up to 200.degree. C. Removal of the 
solvents at elevated temperature is also more advantageous since it has 
been found that the electroconductivity of the antistatic coating can be 
substantially increased, namely by up to power of ten, by thermal 
aftertreatment of the coatings at temperatures of from 50.degree. to 
250.degree. C., preferably from 100.degree. to 200.degree. C. The thermal 
aftertreatment can be combined directly with removal of the solvent or 
alternatively carried out at an interval after production of the 
antistatic coating. 
The duration of the heat treatment is 5 seconds to 5 minutes, depending on 
the shape and material of the coated plastic mounding and on the type of 
polymer used for the coating. 
The heat treatment may, for example, be carried out by moving the coated 
plastic moulding through a heat chamber at the desired temperature at a 
rate such that the residence time desired at the selected temperature is 
achieved, or bringing the coated plastic moulding into contact with a 
hotplate at the desired temperature for the desired residence time. 
When the process according to the invention is used for imparting 
antistatic properties on plastic films, an embodiment which is 
particularly interesting in industry comprises combining the heat 
treatment of the coated films with mechanical deformation of the films. 
Simultaneous heat treatment and mechanical deformation of this type takes 
place in the production of plastic mouldings from plastic films by 
thermoforming the films. 
After removal of the solvents (drying) and before the thermal 
aftertreatment, it may be advantageous to wash the excess oxidant out of 
the coating using water. 
With the aid of the process according to the invention for imparting 
antistatic properties, adherent and mechanically resistant coatings having 
surface resistances up to 1.OMEGA. can be obtained in a simple manner. 
A particularly advantageous embodiment of the process according to the 
invention for imparting antistatic properties on plastic mouldings, in 
particular plastic films, comprises, with separate application of 
thiophene and oxidant, initially coating the plastic moulding to be 
provided with antistatic properties with a solution of the oxidant in an 
organic solvent containing a water-insoluble or sparingly-soluble organic 
binder, removing the organic solvent from this coating, treating the 
oxidant-coated plastic moulding with a solution of thiophene in an organic 
solvent which dissolves neither the plastic material to be provided with 
antistatic properties nor the binder and oxidant applied to the plastic 
surface; after this treatment, also removing the organic solvent from the 
coating applied to the moulding, and finally freeing the coating thus 
obtained from inorganic compounds which are not polymerically bound, for 
example unused oxidant, by washing with water. 
In the case where thiophene and the oxidant are applied together, the 
coating obtained after removal of the solvent is washed with water, in 
particular when the oxidant used was iron(III) salts and when these iron 
salts interfere in the coating when the antistatic plastic mouldings are 
used further; this is the case, in particular, when antistatic films are 
used for packing electronic components. 
The process according to the invention is particularly suitable for the 
production of antistatic plastic films, for example from polyesters, 
polycarbonates and polyamides. Due to their transparency and durable 
antistatic properties, even under mechanical and thermal stress, these 
antistatic plastic films according to the invention are suitable for the 
production of tranparent packing parts by thermoforming. The process 
according to the invention is furthermore suitable for the production of 
printing circuit boards for the electronics industry. For production, 
plastic sheets are printed with the thiophene derivatives of the formula 
(II) to be used according to the invention and with the optionally 
thickened solutions containing the appropriate oxidants. 
The invention furthermore relates to the use of the new polythiophenes of 
the formula (I) as electrode material or rechargeable batteries. 
The use of polythiophenes in rechargeable batteries is in itself known 
(see, for example, ACTUAL, CHIM. 10 (1985) 15 to 23; J. APPL. ELEKTROCHEM, 
17 (1987) 607 to 612). However, in the second-named publication attention 
is drawn to the low stability of the polythiophenes and in SYNTH, METALS 
18 (1987) 625 to 630 it is pointed out that the stability of 
polythiophenes when used as electrode material for rechargeable batteries 
is considerably lower than that of polypyrrole. 
It has, however, surprisingly been found that the stability of the new 
poly-3,4-disubstituted thiophenes is not only considerably superior to 
that of the known polythiophenes but also even to that of polypyrrole and 
that they are therefore very suitable for use as electrode material for 
rechargeable batteries. It has been found that the new polythiophenes have 
a lower rate of self-discharge and can be re- and discharged (i.e. 
cyclised) more frequently than polypyrrole. This increased stability even 
enables the new polythiophenes to be used in aqueous electrolytic systems, 
such as for example in alkali batteries. 
The electrochemical oxidative polymerisation of the 3,4-disubstituted 
thiophenes of the formula (II) can be carried out at temperatures from 
-78.degree. C. up to the boiling point of the solvent employed. The 
electrolysis is preferably carried out at temperatures of -20.degree. C. 
to 60.degree. C. 
The reaction times are from 0.5 to 24 hours, depending on the monomer, the 
electrolyte, the temperature of electrolysis and the current density 
employed. 
If the thiophenes of the formula (II) are liquid the electropolymerisation 
can be carried out in the presence or absence of solvents which are inert 
under the conditions of electrolysis; the electropolymerisation of solid 
thiophenes of the formula (III) is carried out in the presence of solvents 
which are inert under the conditions of electrolysis. In particular cases 
it may be advantageous to use solvent mixtures and/or to add solubilisers 
(detergents) to the solvents. 
The following may be mentioned as examples of solvents which are inert 
under the conditions of electrolysis; water; alcohols such as methanol and 
ethanol; ketones such as acetophenone; halogenated hydrocarbons such as 
methylene chloride, chloroform, carbon tetrachloride and 
fluorohydrocarbons; esters such as ethyl acetate and butyl acetate; 
aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic 
hydrocarbons such as pentane, hexane, heptane and cyclohexane; nitriles 
such as acetonitrile and benzonitrile; sulphoxides such as dimethyl 
sulphoxide; sulphones such as dimethyl sulphone, phenylmethyl sulphone and 
sulpholane; liquid aliphatic amides such as methyl acetamide, dimethyl 
acetamide, dimethylformamide, pyrrolidone, N-methylpyrrolidone, 
caprolactam and N-methylcaprolactam; aliphatic and mixed 
aliphatic-aromatic ethers such as diethyl ether and anisole; and liquid 
ureas such as tetramethylurea or N,N-dimethylimidazolidinone. 
For the electropolymerisation electrolytic additives are added to the 
3,4-disubstituted thiophenes of the formula (II) or to the solutions 
thereof. The electrolytic additives preferably used are free acids or 
standard conducting salts which display a certain degree of solubility in 
the solvents used. The following have for example proven to be suitable as 
electrolytic additives: free acids such as p-toluene-sulphonic acid and 
methanesulphonic acid, as well as salts containing alkyl sulphonate, aryl 
sulphonate, tetrafluoroborate, hexafluorophosphate, perchlorate, 
hexafluoroantimonate, hexafluoroarsenate and hexachloroantimonate anions 
and alkali metal, alkaline earth metal or optionally alkylated ammonium, 
phosphonium, sulphonium and oxonium cations. 
The electrolytic additives are used in such a quantity that a current of at 
least 0.1 mA flows during electrolysis. 
The concentrations of the monomeric thiophenes can be between 0.01 and 100% 
by weight (in the case of liquid thiophene); the concentrations are 
preferably 0.1 to 5% by weight. The concentration of the monomers in the 
electrolytic solutions has an influence on the morphology of the 
polythiophene deposited; at low concentrations, for example of 1 g of 3 
g/l of electrolytic solution, thin polymer films with a large surface area 
are formed, at higher concentrations thick compact polythiophene films are 
obtained. Polythiophene films with a large surface area have proven 
particularly suitable for use in batteries. 
The electropolymerisation can be carried out discontinuously or 
continuously. Materials which have proven suitable as electrode material 
are the known materials such as noble metals and steel, e.g. in the form 
of platinum sheets, steel plates, noble metal or steel nets, 
carbon-black-filled polymers, metallised insulating layers, carbon felts, 
etc. Electrodes coated with a swellable polymer film, for example a 
polyvinyl chloride film, can be particularly advantageous; these swellable 
polymer film substrates impart particularly favourable mechanical 
properties on the polythiophene films deposited thereon. 
The current densities for the electro-polymerisation can vary within wide 
limits: current densities of 0.0001 to 100, preferably 0.01 to 40 
mA/cm.sup.2 are usually employed. Voltages of about 0.1 to 50 V are formed 
at such current densities. 
The thiophenes of the formula (II) can also be copolymerised with other 
polymerisable heterocyclic compounds, such as for example with pyrrole. It 
has been found that the mechanical properties of the polythiophene films 
can be improved without any adverse effect on their advantageous 
electrical properties if the alkylene dioxythiophenes of the formula (II) 
are copolymerised with 1 to 60% by weight of pyrrole (the percentage by 
weight is based on the total weight of the monomers to be polymerised). It 
has also been found that the electrical properties of polypyrrole films 
can be stabilised by copolymerising pyrrole with small quantities of about 
1 to 20% by weight (the percentage by weight is based on the total weight 
of the monomers to be polymerised) of alkylene-dioxythiophenes of the 
formula (II). 
The polythiophene films produced during electrolysis can be left on the 
electrodes if they are to be used as electrodes in rechargeable batteries; 
they can however also be stripped off and applied to metal nets. The 
polythiophenes can however also be processed into mouldings, in which case 
polymeric binders and, where appropriate, finely divided conductive 
materials such as conductive carbon blocks, conductive tin dioxide doped 
with indium or antimony, metal powders or metal flakes are added. These 
mouldings can then be inserted into the batteries.

EXAMPLE 1 
2.84 g of 3,4-ethylenedioxy-thiophene are added at 0.degree. C. to the 
stirred solution of 8.11 g of FeCl.sub.3 in 100 ml of acetonitrile. After 
stirring has been continued for a brief time, the precipitate is filtered 
off under suction, washed with acetonitrile and subsequently dried. 
Yield: 1.1 g, electroconductity of the compressed powder disc: 2.3 S/cm 
(determined by the four-point method). 
If 100 ml of cyclohexane are added to the greenish blue clear filtrate, a 
further fraction of poly(3,4-dioxyethylene)-thiophene is obtained. 
Yield: 1.33 g, electroconductivity of the compressed powder disc: 
3.7.times.10.sup.-2 S/cm (determined by the four-point method). 
EXAMPLE 2 
The solution of 1 g of 3,4-ethylenedioxy-thiophene and 5 g of iron(III) 
p-toluenesulphonate in 45 g of a 1:1 mixture of isopropanol and acetone is 
applied to a polycarbonate film using a hand coater (wet film thickness: 
about 25 .mu.m, corresponding to a dry film thickness of about 3 .mu.m). 
After the solvent has been removed at room temperature, the coated film is 
stored for a further 12 hours. It then has a surface resistance (R.sub.s) 
of 100.OMEGA.. 
A sample of the film obtained in this way is warmed at 180.degree. C. for 
10 minutes. After cooling, the sample then has a surface resistance 
(R.sub.s) of 60.OMEGA.. 
EXAMPLE 3 
The solution of 1 g of 3,4-ethylenedioxy-thiophene, 5 g of iron(III) 
p-toluenesulphonate and 5 g of poly(vinyl acetate) in 25 g of a 1:1 
mixture of isopropanol and acetone is applied at room temperature to a 
polycarbonate film using a hand coater. The film is dried at room 
temperature to constant weight. 
The film obtained in this way has a surface resistance (R.sub.s) of 
1000.OMEGA.. 
A sample of the film is heated at 180.degree. C. for 10 seconds; the film 
then has a surface resistance (R.sub.s) of 120.OMEGA.. The film is 
transparent both at room temperature and after treatment at 180.degree. C. 
EXAMPLE 4 
A solution of 1 g of 3,4-ethylenedioxy-thiophene, 2 g of iron(III) 
p-toluenesulphonate and 5 g of poly(vinyl acetate) in 45 g of 1:1 mixture 
of isopropanol and acetone is applied to a PVC film using a hand coater 
(wet film thickness: about 25 .mu.m, corresponding to a dry film thickness 
of about 3.5 .mu.m. The film is dried at room temperature to constant 
weight (15 hours). The surface resistance (R.sub.s of the film is 
420.OMEGA.. 
The drying time can be shortened to 1 hour by heating the solution-coated 
film to 50.degree. C. 
EXAMPLE 5 
The suspension of 0.5 g of poly(vinyl alcohol), 0.3 g of ammonium 
peroxodisulphate and 0.5 g of 3,4-ethylenedioxy-thiophene in 10 ml of 
demineralized water is applied to a polyester filmm using a hand coater 
(wet film thickness: about 25 .mu.m, corresponding to a dry film thickness 
of about 2.5 .mu.m). In order to remove the water, one half of the film is 
stored at room temperature to constant weight (15 hours); the other half 
is warmed at 60.degree. C. for 1 hour. 
Both halves of the film have a surface resistance (R.sub.s) of 
8.times.10.sup.3 .OMEGA.. 
This antistatic film is suitable, for example, as a base for photographic 
films. 
EXAMPLE 6 
A solution of 0.6 g of FeCl.sub.3, 1 g of poly(vinyl acetate) and 19 g of 
acetone is applied to a polyamide film using a hand coater (wet films 
thickness: about 25 .mu.m, corresponding to a dry film thickness of about 
1 to 2 .mu.m). After the solvent has removed (drying), the coated film is 
dipped for 2 seconds into a 5% strength solution of 
3,4-ethylenedioxy-thiophene in a (1:1) mixture of n-hexane and of toluene. 
After drying at room temperature, the coated film is washed with running 
water until the washings contain virtually no Fe.sup.+3 ions. 
A transparent film is obtained; surface resistance (R.sub.s) of the film: 
about 10.sup.3 .OMEGA.. 
EXAMPLE 7 
A solution of 0.25 g of 3,4-ethylenedioxy-thiophene, 1 g of iron(III) 
p-toluenesulphonate and 1 g of poly(vinyl acetate) in 18 g of a 2:1 
mixture of isopropanol and acetone is applied to a polycarbonate film 
using a hand coater (wet film thickness: about 25 .mu.m, corresponding to 
a dry film thickness of 1 to 2 .mu.m). After the solvent has been removed 
(drying) at 60.degree. to 80.degree. C., the coated film is washed with 
running water until the washings contain virtually no Fe.sup.3+ ions. 
A transparent film is obtained; surface resistance (R.sub.s) of the film: 
350.OMEGA.. 
A sample of the film is heated at 180.degree. C. for 5 seconds. The surface 
resistance of the film drops to R.sub.s : 20.OMEGA. to this thermal 
treatment. 
EXAMPLE 8 
The solution of 10 g of poly(vinyl acetate) and 20 g of iron(III) tosylate 
in 100 g of isopropanol and 50 g of acetone is applied to a polycarbonate 
film using a hand coater (thickness 200 .mu.m). The film is dried at room 
temperature to constant weight. The dry film thickness of the coating is 
about 1 .mu.m. 
The film coated in this way is subsequently cut into three pieces of equal 
size. The individual pieces are dipped for 5 seconds the 1st piece into a 
5% strength solution of pyrrole in cyclohexane (film A), the second piece 
into a 5% strength solution of 3,4-ethylenedioxythiophene in cyclohexane 
(film B) and the 3rd piece into a 5% strength solution of 
3,4-propylene-1,2-dioxy-thiophene (film C). 
These three film samples A, B and C are dried at room temperature to 
constant weight and subsequently washed in running water until virtually 
no iron(III) ions can be detected in the washing water. 
The film pieces A, B and C are subsequently aged in a saturated 
water-vapour atmosphere at 90.degree. to 100.degree. C. and their surface 
resistance is determined as a function of time. The measurement values 
obtained for the individual film pieces are plotted in the diagram in FIG. 
1. The high hydrolysis resistance of the antistatic coatings obtained 
using the polythiophenes according to the invention can be seen from the 
curves obtained for the individual film samples. It can be seen from the 
diagram that the surface resistance of the Makrolon film treated with the 
polythiophenes according to the invention remains virtually unchanged, 
while the surface resistance of the Makrolon film treated with polypyrrole 
increases considerably after only a short time. 
In another test one strip each of films A and B (each strip measuring 2 
cm.times.5 cm) were provided with contacts of conductive silver (distance 
between the two contacts: 4 cm). 
The two strips of films A and B, provided with the contacts were each 
immersed separately in a beaker filled with 1N aqueous HCl. Then the pH 
value of the aqueous HCl solutions was increased steadily by adding 
aqueous NaOH and at the same time the electrical resistance of the strips 
of film was determined at the various pH values. The measurements revealed 
that the electrical resistance of film B remained almost constant over the 
pH-value range of 1 to 10--the resistance only increases from 
12.5.times.12.sup.2 .OMEGA. at pH 1 to 17.5.times.10.sup.2 .OMEGA. at pH 
10--whereas the resistance of film A increases greatly, namely from 
4.times.10.sup.5 .OMEGA. at pH 1 to 5.5.times.10.sup.6 .OMEGA. at pH 10. 
EXAMPLE 9 
The electrical conductivities mentioned for the polythiophenes in the 
following examples were, unless stated otherwise, determined by the 
4-electrode method using compressed powder discs. 
An electrolytic cell, equipped with two platinum electrodes was used for 
the electrochemical oxidation of the alkylene-dioxy thiophenes; the 
surface area of the individual platinum electrodes was 2.times.8 cm.sup.2 
; the distance between the electrodes was 1 cm. 
This electrolytic cell is filled with a solution of 284 mg (2 mmol) of 
3,4-(ethylene-1,2-dioxy)-thiophene and 1.71 g (5 mmol) of 
tetrabutylammonium perchlorate in 100 ml of acetonitrile. Electrolysis is 
carried out for 4 hours at room temperature at a constant current strength 
of 1.5 mA (current density: 0.094 mA/cm.sup.2). A voltage of 3.15 V forms. 
The polythiophene produced is deposited on the anode in the form of a 
blue-black coating. When electrolysis is complete the coating is washed 
with acetonitrile and dried in a high vacuum at 50.degree. C. 
On removing the coating mechanically from the anode 46 mg of 
poly-3,4-(ethylene-1,2-dioxy)-thiophene perchlorate with an electrical 
conductivity of about 200 S/cm are obtained. 
Using the same method of procedure the solutions (2 mmol of thiophene+5 
mmol of electrolyte in 100 ml of acetonitrile) of the thiophenes and 
electrolytes mentioned in the following table were electrolysed in the 
above-described electrolytic cell at a constant current strength of 1.5 mA 
and a current density of 0.094 mA/cm.sup.2 at the temperatures mentioned 
in the table. The blue-black polythiophene coatings obtained during the 
electrolysis were worked up as described above. The voltages which form 
during electrolysis, the duration of electrolysis, the yields of 
polythiophenes and the electrical conductivities of the polythiophenes 
obtained are summarised in the following table. 
TABLE 
__________________________________________________________________________ 
##STR5## 
Temperature 
Voltage 
Duration of 
Elektrolyte of electrolysis 
formed 
electrolysis 
Example 
A cation 
anion [.degree.C.] 
[V] [h] 
__________________________________________________________________________ 
10 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
RT 3.45 24 
11 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
PF.sub.6 RT 3.36 4 
12 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
BF.sup.4 RT 3.36 4 
13 CH.sub.2CH.sub.2 
H.sup..sym. 
##STR6## RT 1.3 4 
14 CH.sub.2CH.sub.2 
Na.sup..sym. 
BF.sub.4.sup..crclbar. 
RT 1.89 60 
15 CH.sub.2CH(CH.sub. 3) 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
PF.sub.6.sup..crclbar. 
RT 2.6 24 
16 CH.sub.2CH(C.sub.6 H.sub.13) 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
RT 2.55 24 
17 CH.sub.2CH(C.sub.10 H.sub.21) 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
RT 3.06 24 
18 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
-20 3.19 18 
19 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
0 3.27 24 
20 CH.sub.2CH.sub.2 
(C.sub.4 H.sub.9).sub.4 N.sup..sym. 
ClO.sub.4.sup..crclbar. 
-40 3.17 24 
__________________________________________________________________________ 
EXAMPLE 21 
An electrolytic cell equipped with a platinum electrode (electrode surface 
area 4.times.4 cm.sup.2) and a carbon felt electrode SPC 7016 (0.05 
kg/m.sup.2, made by the Sigri company) with the same surface area 
(distance between electrodes: 2 cm) is filled with a solution of 5.68 g 
(40 mmol) of 3,4-(ethylene-1,2-dioxy)-thiophene and 4.34 g (20 mmol) of 
tetraethylammonium tetrafluoroborate in 250 ml of acetonitrile. The carbon 
felt electrode is arranged as the anode. Electrolysis is carried out for 2 
hours at a constant current density of 5 mA/cm.sup.2. When electrolysis is 
complete the blue-black coating deposited on the anode is washed with 
acetonitrile and dried at 50.degree. C. in a high vacuum. 
On careful mechanical separation of the coating formed, 66 mg of 
poly-3,4-(ethylene-1,2-dioxy)-thiophene tetrafluoroborate with a 
conductivity of 31 S/cm are obtained. 
EXAMPLE 22 
An electrolytic cell equipped with two platinum electrodes (surface area of 
the individual electrodes: 2.times.8 cm.sup.2 ; distance between 
electrodes: 1 cm) is filled with a solution of 284 mg (2 mmol) of 
3,4-(ethylene-1,2-dioxy)-thiophene and 1.71 g (5 mmol) of 
tetrabutylammonium perchlorate in 100 ml of acetonitrile. The platinum 
electrode arranged as the anode is coated with a polyvinyl chloride film 
of a thickness of 0.06 mm. 
Electrolysis is carried out for 24 hours at a temperature of 20.degree. C. 
and a constant current strength of 1.5 mA (current density: 0.094 
mA/cm.sup.2), a voltage of 2.1 V being formed. 
The blue transparent film formed on the anode during electrolysis is 
stripped from the electrode after drying in a high vacuum at 50.degree. C. 
A cross-sectional photograph of this film shows that a 0.002 mm thick layer 
of poly-3,4-(ethylene-1,2-dioxy)-thiophene perchlorate has formed within 
the polyvinyl chloride film on the side facing the electrode. The 
conductivity of this layer is 200 S/cm (determined by the 4-electrode 
method on the side of the film facing the electrode). 
EXAMPLE 23 
((Cyclovoltametric determination of the capacity of the 
poly-3,4-(ethylene-1,2-dioxy)-thiophene films for absorbing and releasing 
electric charges (re- and dischargeability)). 
A film of poly-3,4-(ethylene-1,2-dioxy)-thiophene hexafluorophosphate 
produced by the electrochemical oxidation of 
3,4-(ethylene-1,2-dioxy)-thiophene carried out galvanostatically using a 
current density of 0.5 mA/cm.sup.2 was used for the determination; the 
electrode coated with this film was arranged in a 0.1 molar solution of 
tetrabutylammonium hexafluorophosphate in propylene carbonate. 
In the cyclovoltametric measurement the polymer film displayed an oxidation 
peak at +0.120 V and a reduction peak at -0.457 V (compared with Ag/AgCl) 
at a feed rate of 10 mV/S. The cyclovoltametric measurement revealed that 
the polymer film can be reversibly charged and discharged (cyclised) in 
the range between -1.28 V and +1.42 V (compared with Ag/AgCl) at a feed 
rate of 0.5 mV/S with a charge loss of only approximately 0.01% per cycle. 
The degree of charging is 33 mol % and the charging capacity is 62 Ah/kg 
based on the neutral polymer. The very low self-discharging rate of the 
film shows that, in the charged state, it is not changed by overoxidation 
effects or by additional side reactions. In the diagram shown in FIG. 2 
the charging capacity of the polymer film is recorded as a function of the 
number of charges and discharges (cycles). It is clear from the position 
of the measuring points in the diagram that the charging capacity has 
hardly changed at all after 15 cycles. 
In polypyrrole films which have been produced and cyclised under identical 
conditions a similar degree of charging (30 mol%) is generally obtained as 
with poly-3,4-(ethylene-1,2-dioxy)-thiophene. The charge losses during 
charging and discharging at between -1.28 V and 1.42 V are however 
considerable and are 5% per cycle. 
In a second test series a 0.1 molar solution of lithium perchlorate in 
water was used as the electrolyte instead of the 0.1 molar solution of 
tetrabutylammonium hexafluorophosphate in propylene carbonate. 
Equal success was obtained on charging and discharging the polymer film in 
this electrolyte. Although the discharge current decreased slightly after 
the first few cycles it reached a constant value after about 30 cycles. It 
was only possible to cyclise a comparable polypyrrole film twice under the 
same conditions. 
In a third test series a film of poly-3,4-(ethylene-1,2-dioxy)-thiophene 
hexafluorophate produced by the electrochemical oxidation of 
3,4-(ethylene-1,2-dioxy)-thiophene carried out potentiostatically at +1.6 
V (compared with Ag/AgCl) at an average current density of 0.5 mA/cm.sup.2 
was used. The Pt electrode coated with the film was arranged in a 0.1 
molar solution of tetrabutylammonium hexafluorophosphate in methylene 
chloride. The charging and discharging of the film was determined 
cyclovoltrametrically at between -1.10 V and +1.70 V at a feed rate of 2 
mV/S. A degree of charging of 41 mol% was obtained. This corresponds to a 
charging capacity of 77 Ah/kg. The charge losses per cycle are 0.06%. The 
higher charging capacity is only associated with a slight increase in the 
loss rate. A charge loss of 15% for each cycle was obtained for 
polypyrrole films charged and discharged under the same conditions.