WO1993022775A1

WO1993022775A1 - Electrically conductive polyaniline with phosphorus-containing dopant

Info

Publication number: WO1993022775A1
Application number: PCT/US1993/003960
Authority: WO
Inventors: Chien-Chung Han
Original assignee: Allied-Signal Inc.
Priority date: 1992-04-28
Filing date: 1993-04-28
Publication date: 1993-11-11

Abstract

A thermally stable electrically conductive polyaniline comprising a polyaniline homopolymer or copolymer doped with an organic phosphorus acid.

Description

ELECTRICALLY CONDUCTIVE POLYANILINE WITH PHOSPHORUS-CONTAINING DOPANT

1. Field of the Invention

This invention relates to thermally stable electrically conductive substituted or unsubstituted

10 polyanilines, and to compositions comprising such polyanilines and other electrically conductive or non- conductive materials such as polymers. Another aspect of this invention relates to a method of using such polyanilines and compositions to give conducting polymer

15 articles, including films, parts, inks, adhesives, printings, fibers and coatings, and to a method for fabricating such articles.

2. Prior Art

20

There has recently been an increased interest in the electrochemistry and electrical phenomena of polymeric systems having extended conjugation in at least one backbone chain such as polyaniline. See for example,

25 U.S. Patent No. 5,008,041, O90/13601, EP Appl. 0399299A2 Cao et al., Polymer. 1989, vol. 30, pp. 2505-2311, U.S. Patent No.4,983,322, 4,462,929, 3,963,498 and 4,025,463; European Patent No.0017717; U.S. Patent Nos.4,855,361, 4,798,685, 4,806,271, 4,822,638, 4,851,487, 4,798,685 and

30 5,069,820; and PCT 090/10297.

SUMMARY OP THE INVENTION

*» One aspect of the present invention relates to a if thermally stable, electrically conductive polyaniline

35 comprised of a polyaniline homopolymer or copolymer and doped with one or more organic "thermally stable phosphorous acid dopant" and to articles fabricated from said polyaniline. As used herein a "phosphorus acid" is an organic acid which includes at least one protonic acid moieties and at least one phosphorus atoms.

This invention also relates to a composition comprising a polyaniline of this invention and one or more organic or inorganic materials as for example a composition comprising a matrix of one or more thermoplastic polymers, one or more ther osetting resins or a combination thereof having dispersed therein one or more doped polyanilines of this invention, and to articles formed from this composition and to a process for forming the compositions of this invention. This invention provides several unexpected benefits. For example, the electrically conductive polyaniline of this invention exhibits enhanced thermal stability.

DETAILED DESCRIPTION OP THE INVENTION

The thermally stable electrically conductive polyaniline of this invention comprises two essential ingredients. One essential ingredient is a substituted or unsubstituted polyaniline. As used herein, a "polyaniline" is a homopolymer or a copolymer in which at least 50 sole % of the recurring monomeric units are derived from unsubstituted or substituted anilines of the formwla:

FQrffl-l- I

wherein:

n is an integer from 0 to 5; m is an integer from 0 to 5, with the proviso that the sum of n and m is equal to 5 and with the further proviso that at least one position on the aniline ring, preferably the para position, is substituted with a substitutent which will allow coupling of aniline rings such or halo, hydrogen or other leaving group, to form polyaniline; _x is the same or different at each occurrence and is selected from the group consisting of phosphonic acid or salts or esters thereof, cyano, nitro, boric acid or salts or esters thereof, phosphoric acid or salts or esters thereof, halo, carboxylic acid or salts or esters thereof, phosphonic acid or salts or esters thereof, halo, hydroxy, cyano, sulfinic acid or salts or esters thereof, phosphinic acid and salts or esters thereof, amido, hydroxyamine, sulfonic acid and salts or esters thereof, nitro, deuterium, amino, or substituted or unsubstituted alkenyl, alkoxy, cycloalkyl, cycloalkenyl, alkanoyl, alkylthio, alkyl, aryloxy, alkylthioalkyl, arylalkylamino, alkylaryl, arylalkyl, alkylamino, arylamino, dialkylamino, diaryla ino, aryl, alkylsulfinyl, aryloxyalkyl, alkylsulfinylal yl, alkoxyalkyl, alkylsulfonyl, arylthio, alkylsulfonylalkyl, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, alkylsilane or alkyl wherein permissible substituents are one or more phosphonic acid or salts or esters thereof, sulfonic acid or salts or esters thereof, phosphoric acid or salts or esters thereof, boric acid or salts or esters thereof, sulfate, sulfinic acid or salts or esters thereof, quaternary ammonium, hydroxylamine, amido, phosphinic acid or salts or esters thereof, carboxylic acid or salts or esters thereof, halo, nitro, cyano or epoxy substituents; or any two R_x groups together or one or more R_ groups together with an R₂ group may form a substituted or unsubstituted alkylene, alkenylene, or alkynylene chain completing a 3, 4, 5, 6, 7, 8, 9 or 10 membered aromatic, heteroalicyclic, heteroaromatic or alicyclic ring, which ring may optionally include one or more divalent nitrogen, sulfur, sulfinyl, ester, carbonyl, sulfonyl, or oxygen atoms wherein permissible substituents are one or more phosphonic acid or a salt or an ester derivative, sulfonic acid or a salt or an ester derivative, phosphoric acid or a salt or an ester derivative, boric acid or a salt or an ester derivative, sulfate, sulfinic acid or a salt or an ester derivative, or a salt or an ester derivative thereof, quaternary ammonium, amido, hydroxylamine, phosphinic acid or a salt or ester thereof, carboxylic acid or a salt or ester thereof, hydroxyamino, halo, nitro, cyano or epoxy moieties; or R_ is a divalent organic moiety bonded to the same or a different substituted or unsubstituted aniline moiety or R_x is an aliphatic moiety having repeat units of the formula:

(OCH₂CH₂)qO-CH₃, (OCH₂CH(CH₃)),0-CH₃, (CH₂), CP₃, (CF₂),-CF₃ or (CH.)_q CH₃

wherein q is a positive whole number; and

R₃ is the same or di ferent at each occurrence and is hydroge or _t_, preferably hydrogen.

Preferred polyaniline consists of repeat units of the Formulas II and/or III:

Formula II

Formula III

or a combination thereof having various ratios of the above repeat units in the polyaniline backbone such as leucoemeraldine, protoemeraldine, emeraldine, nigraniline and pernigraniline. Polyanilines in the practice of this invention are more preferably those of the Formula IV:

is: m, m, and R_ and R₂ are as described above; x and y are the same or different at each occurrence and are integers equal to or greater than 0, with the proviso that the sum of x and y is greater than 0, preferably where x is an integer equal to or greater than 0 and/or that the ratio of x to y is greater than or equal to about 0, more preferably said ratio is equal to or greater than 0.5 and most preferably said ratio is equal to or greater than about 1; and z is the same or different at each occurrence and is an integer equal to or greater than about 5.

Preferred for use in the practice of this invention are polyanilines of the above Formula IV in which: n is an integer from 0 to about 2; m is an integer from 2 to 4, with the proviso that the sum of n and m is equal to 5;

Ri is alkyl, alkoxy or sulfonic acid or a salt or ester derivative thereof;

R₂ is hydrogen or methyl; x is an integer equal to or greater than 1; y is equal to or greater than 0, with the proviso that the ratio of x to y is greater than about 1; and z is an integer equal to or greater than about 5; Particularly preferred for use in the practice of this invention are polyanilines of the above Formula IV in which: _ n is an integer from 0 to 1; m is an integer from 3 to 4, with the proviso that the sum of n and nt is equal to 4;

R_ is alkyl or alkoxy having from 1 to about 20 carbon atoms:

R₂ is hydrogen; x is an integer equal to or greater than 2; y is equal to or greater than 0, with the proviso that the ratio of x to y is greater than about 2; and z is an integer equal to or greater than about 5.

Amongst the particularly pre erred embodiments, most preferred for use in the practice of this invention are polyanilines of the above Formula IV in which: n is an integer from 0 to 1; m is an integer from 3 to 4, with the proviso that the sum of n and m is equal to 4;

R_x is alkyl or alkoxy from 1 to about 6 carbon atoms (preferably from 1 to about 3 carbon atoms);

R₂ is hydrogen; x is an integer equal to or greater than 2; y is equal to or greater than 1, with the proviso that the ratio of x to y is greater than about 2; and z is an integer equal to or greater than about 5. In the embodiments of this invention of choice, the polyaniline is derived from unsubstituted aniline.

In general, the number of repeat units in the polyaniline homopolymer or copolymer are not critical and may vary widely. The greater the number of repeat units the greater the viscosity and molecular weight of the polyaniline homopolymer or copolymer.. In those applications where a polyaniline homopolymers or copolymers of relatively low molecular weight and viscosity is required, such materials may be used, and in those applications where a polyaniline hompolymer or copolymer of relatively high molecular weight and viscosity is required, then such materials can be used. The number of repeat units is at least about 10. The upper limit cam vary widely depending on the desired molecular weight and viscosity and the required degree of processibility, such as melt processibility, solution processibility and the like. In the preferred embodiments of the invention, the number of repeat units is at least about 20, and in the particularly preferred embodiments, the number of repeat units is at least about 30. Amongst the particularly preferred embodiments, most preferred are those embodiments in which the number of repeat units is at least about 40.

Polyaniline homopolymers and copolymers can be conveniently prepared throught conventional procedures. Such procedures are well known in the art and will not be described herein in great detail. See for example U.S. Patent Nos. 4,940,640; 4,711,742; 4,521,589; 4,855,361; 4,798,685; 4,806,271; 4,822,638; 4,851,487; 4,940,517; 4,803,681; 4,983,322; 5,006,278 and 4,900,782 and "The Handbook of Conducting Polymers", edited by Terje A. Skotheim, Marcell Dikker, Inc. New York and Basel and references cited therein, all of which is hereby incorporated by reference. For example, preferred polyanilines can be prepared through use of chemical and electrochemical synthetic procedures. For example, one form of polyaniline can be prepared chemically by treating aniline with a suitable oxidant such as ammonium persulfate, (NH*)₂S₂0₈, in excess acid such as 1M HC1 and can be prepared electrochemically by the oxidation of aniline in aqueous fluoroboric acid electrolyte on a platinum foil anode. The polyaniline homopolymer or copolymer is doped with a suitable phosphorus acid dopant to render the polymer electrically conductive, i.e. an electrical conductivity of at least about 10^"β ohm ^_1 cm^"1 by the four-in-line probe method. Any doping procedure may be used. Such methods are conventional and will not be described herein in any great detail. For example, the polyaniline homopolymer or copolymer is best doped by contacting the dopant with the polymer for a time sufficient to dope the polymer to the desired extent. The polymer can be contacted- with the dopant in the gaseous state, in the liquid state, neat, or diluted by some suitable dilutent such as a gas as for example air, or liquid such as water, or an organic liquid. The dopant can be contacted with the polyaniline homopolymer or copolymer either during polymerization or after polymerization. In a preferred embodiment of the invention, the polyaniline homopolymer or copolymer may be doped in either by carrying out the polymerization in the presence of an acid having a pKa in the solution equal to or less than that of the homopolymer or copolymer. In general, the higher the pKa of the polyaniline homopolymer or copolymer, the higher the acid pKa can be used to provide a conductive polymer; and conversely, the lower the pKa of the polyaniline polymer the lower the pKa of the acid can be used to provide a desired degree of electrical conductivity. The pKa of the acid is preferably equal to or less than about 5, more preferably equal to or less than about 4, and the most preferably euqal to or less than about 3.

In another preferred embodiment of the invention, the polyaniline copolymer or homopolymer can be doped after polymerization. For example, the polyaniline homopolymer or copolymer layer is doped by contact with a solution of the dopant in a suitable solvent such as water.

As a second essential ingredient, the polyaniline of this invention is doped with a "thermally stable phosphorus acid dopant". As used herein, a "thermally stable phosphorus acid dopant" is a phosphorus acid which the is capable of doping the polyaniline to an electrical conductivity of at least about 10^"β ohm ^_1 cm^"1 by the four-in-line probe method and which retains at least about 10% of the dopant on heating the doped polyaniline at a temperature of 150°C for a period of 10 min. under dynamic vacuum. In general, the acid has a pKa equal to or less than that of the substituted or unsubstituted polyaniline under use conditions. In general, the higher the pKa of the substituted or unsubstituted polyaniline the higher the acid pKa that can be used to provide a conductive polymer; and conversely, the lower the pKa of the substituted or unsubstituted polyaniline, the lower the pKa of the acid necessary to provide a desired degree of electrical conductivity. The pKa of the acid is preferably equal to or less than about 5, more preferably equal to or less than about 4, and the most preferably equal to or less than about 3. Preferred dopants are those containing anionic moieties of the formula:

R*(P0₃") (P0₂(R.)^")_r(P0₂-)_r(PO(R.)^")_r and having one or more cationic moieties selected from the group consisting of: M*¹ wherein:

R* is the same or different at each occurrence and is an organic radical which may optionally include one or more heteroatoms such as phosphorus, nitrogen, oxygen, sulfur or the like;

R_ is the same or different at each occurrence and is hydrogen or is selected from among R* substituents;

M is a species having a positive charge equal to s, provided that at least one of M*" is a proton or a moiety which can be transformed by suitable means such as radiation, heat, chemicals and the like, into a proton under use or process conditions such as NH*⁺, ⁺N(CH₃)₂H₂, ^"_.(C₂H₅)H₃, Ph₃S⁺, and the like; s is an integer equal to or greater than 1; r is the same or different at each occurrence and is 0 or an integer equal to or greater than 1, with the proviso that at least one of r is other than 0.

More preferred dopants are of the formula:

R* (P0₂ (Re) M) . (PO_M₂) _b (P0₂M₂) _c (PO (R«) M) „ or

A-C-[-(Xι)_f-(R₇) .-(Xa)_h-(R>)ι-3i-(B) _J-]_k-C

or

wherein:

M is H*, or other metal or non-metal cation with the proviso that at least one of M is H* or a moiety which can be transformed into a proton under use or process conditions by suitable means such thermal, chemical or photochemical means, as for example, *NH₄,⁺N(CH₃)₂H₂, Ph₃S⁺, ⁺N(C₂H₃)H₃ and the like a, b, c, d and e are the same or different and are 0 or integers equal to or greater than 1, with the proviso that at least one of a, b, c or d is other than 0; f, g, h, i and j are the same or different at each occurrence and are 0 or 1; k is 0 or an integer equal to or greater than 1; i is 0 or an integer equal to or greater than 1;

Re is hydrogen, substituted or unsubstituted alkyl, arylalkyl, alkylaryl, aryloxy, arylalkoxy, alkoxyaryl, alkoxyalkyl, or alkoxy wherein the permissible substitutent are selected from the group consisting of R* substituents;

R* is substituted or unsubstituted alkylamino, dialkylamino, aryϊa ino, diaryla ino, arylalkoxy, aryloxy, alkylarylamino, alkylsulfiny1, alkylsulfonyl, alkoxy, alkyl, arylalkyl or alkoxyalkyl, wherein permissible substituents are perhaloalkyl, phenyl, alkoxy, halo, cyano, amino, haloalkyl, hydroxy, sulfonic acid and salts and esters thereof, phosphoric acid and salts and esters thereof, boric acid and salts and esters thereof, sulfinic acid and salts and esters thereof, phosphinic acid and salts and esters thereof, phosphonic acid and salts and esters thereof, carboxylic acid and salts and esters thereof, nitro, and the like; or a polymeric radical of a polymeric acid, such as the polymeric radical of poly(vinyl phosphonic acid) , poly(styrene phosphonic acid), poly(vinyl phosphinic acid), poly(styrene phosphinic acid), and the like;

-X_- and -X₂- are the same or different at each occurrence and are -0-, -N(R_)-,-S-, -Se-, -OC(0)-, - N(A)-, -(O)CO-, -S(0)₂-, -OS(0)₂-, -SO(0)₂-, or -P(R₈)-; R₇ and Rg are the same or different at each occurrence and is alkylene, arylene, or dialkylenearylene; Re is hydrogen or is selected from the group of R₄ substituents;

A- is -PO3M₂, -P0₂(Rβ)M, -P0₂M₂ or -PO(Rβ)M

-B- is -P0₂M-, -POM- or -PO(R_)-; C- is OM;

R₅ is the same or different at each occurrence and is selected from the group consisting of amino, hydroxy, or substituted or unsubstituted R* substituents, aryl, amino, hydroxy or any two R₅ substituents together may form an unsubstituted or substituted . alkylene or alkenylene chain completing a ring system which chain may optionally contain one or more divalent heteroatoms such as -0-, -S-, -S(0₂)-, -N(H)- and the like, wherein permissible substituents are one or more halo, phosphoric acid and salts and esters thereof, hydroxy, boric acid and salts and esters thereof, nitro, cyano, amino, phosphinic acid and salts and esters thereof, alkylamino, dialkylamino, alkylthio, alkoxyalkyl, alkylsulfinyl, alkylsulfony , alkoxy, alkylarylamino, arylamino, diarylamino, sulfinic acid and salts and esters thereof, phosphonic acid and salts and esters thereof, sulfonic acid and salts and esters thereof or carboxylic acid and salts and esters thereof, or R«, R_ or R_ is a moiety of the formula:

-(OCHaCHaJ -OCHs or - (OCH₂CH(CH₃) J _qOCHa

wherein: q is a positive whole number from 1 to about 10. More preferred dopants are acids and/or acid derivatives of the formula:

or A-[-[-(X₁)_-(R₇),-(X₂)_-(R_β)₁-]i-(B)_J-]_-C or

wherein: a, b and e are the same or different and are 0, l or 2, with the proviso that at least one of a or b is not 0; f , _, h, j and 1 are the same or different and are 0 or 1; k is 0 or an integer from 1 to about 400; i is 0 or an integer from 1 to about 20; * is alkyl, alkoxy, phenylalkoxy, alkoxyalkyl or phenylalkyl, either unsubstituted or substituted with one or more hydroxy, amino, fluoro, sulfonic acid or salts or esters thereof, or phosphoric acid or salts or esters thereof;

-X_- and -X₂- are the same or different at each occurrence and are -0-, -N(Rβ)- or -N(A)-; A- is -P0_M₂ or -P0₂(Rβ)M;

-B- is -POM-, -P0₂M- or -PO(R_)-; C- is -OM;

R₃ is the same or different at each occurrence and is selected from the group consisting of halo, hydroxy, amino, alkylamino or dialkylamino, or substituted or unsubstituted alkyl, alkoxy, alkoxyalkyl, phenyl, alkylamino or dialkylamino, wherein permissible substituents are one or more phenyl, hydroxy, amino, sulfonic acid or salts or esters thereof, phosphoric acid or a salt or ester thereof, or phosphonic acid or a salt or ester thereof, or phosphonic acid or a salt or ester thereof or any two R₅ substituents together may form an alkenylene chain completing a naphthalene, anthracene or phenanthrene fused system that may optionally contain heteroatoms, and which may optionally be substituted with one or more alkyl, alkoxy, fluoro, perfluoroalkyl, amino, hydroxy, phosphonic acid or a salt or ester thereof, phosphoinic acid or a salt or ester thereof, fluoroalkyl, sulfonic acid or salts or esters thereof;

M is H* or other metal or non-metal cation, with the proviso that at least one of M is H* or is a moiety which can be thermally transformed into a proton under process conditions;

Re and Re are the same or different at each occurrence and are hydrogen, alkyl, alkoxy, phenoxy or phenyl either unsubstituted or substituted with one or more alkyl or alkoxy groups; and

-R₇- and -R.- are the same or different and are alkylene, phenylene or dialkylenephenylene.

In the especially preferred embodiments of this invention, useful dopants are acids or acid derivatives of the formula:

_U(P0₂(R_β)M)«(P0₃M₂)b or

A-C-C-(Xι)_f- R₇),-(X₂)_h-(R,)ι-]ι-(B)_j-]_-C or

wherein: a and b are the same or different and are 0, 1, 2 or 3, with the proviso that at least one of a and b is not 0; e is 0, 1 or 2; f, g, h, j and 1 are the same or different and are 0 or 1; k is an integer from 1 to about 200; i is an integer from 1 to about 10;

R* is alkyl, alkoxy or phenylene either unsbstituted or substituted with one or more fluoro groups; R₃ is the same or different at each occurrence and are substituted or unsubstituted alkyl or alkoxy wherein permissible substituents are one or more fluoro, or any two R₃ substituents together may form an alkylene or alkenylene chain completing a naphthalene, anthracene or phenanthrene fused system, that optionally contains heteroatoms, which may be substituted with one or more alkyl, perfluoroalkyl, alkoxy, hydroxy, amino, or sulfonic acid or a salt or an ester thereof; e is hydrogen, alkoxy, alkyl, or phenoxy or phenyl either unsubstituted or substituted with one or more alkyl or alkoxy groups;

Rg is hydrogen, alkyl or phenyl;

-R₇- and -Rg- are the same or different and are alkylene; -X_- and -X₂- are the same or different and are -0-, -N(R_)- or -N(A)-;

C- is -OM;

A- is -P0_M₂ or -P0₂(Rβ)M;

-B- is -POM-, -PO_M- or -P0(R.)-; and M is H* or other metal or non-metal cation or a moiety which can be thermally tranformed into a proton under process conditions with the proviso that at least one M is H*.

In the process of the embodiment of this invention of choice, the dopant is an organic phosphorous acid or acid derivative of the formula: R₄(P0₂(R₆)M).(P0₃M₂)_b or

A-C-[-(Xι)_-(R₇).-(X2)h-(Rg)ι-]i-(B).-]_-c or

_b

wherein; a and b are the same or different and are 0, 1, 2 or 3 with the proviso that at least one of a or b is not zero(at least one of a or b is preferably 1); g is 0 or 1 (preferably 1); . e is 0, 1 or 2 (preferably 0 or 1, more preferably i); f, h and 1 are the same or different and are are 0 or 1 (preferably 0) ; j is 0 or 1 (preferably 1) ; k is 0 or an integer from 1 to about 100 (preferably from 1 to about 10) ; i is 0 or an integer from 1 to about 8 (preferably 1 to about 4);

R* is alkyl or alkoxy (preferably of from 1 to about 10 carbon atoms, more preferably of from 1 to about 6 carbon atoms and most preferably from 1 to about 3 carbon atoms) ;

R₇ and Re are alkylene (preferably of from 1 to about 40 carbon atoms, more preferably of from 1 to about 20 carbon atoms and most preferably of from 1 to about 10 carbon atoms)

R₃ is the same or different at each occurrence and is hydroxy, alkyl or alkyl substituted with one or more fluoro groups, or two R₃ groups together may form an alkenylene chain completing a naphthalene fused ring system which may be substituted with one or more hydroxy, alkyl or perfluoroalkyl;

Re and Re are the same or different and are hydrogen or alkyl (preferably of from 1 to about 7 carbon atoms) ; -X_- and -X₂- are the same or different and are -0-, -N(R_β)- or -N(A)-; C- is -OM;

A- is -P0₃M₂ or -P0₂(Rβ)M; -B- is -POM-, -P0₂M- or -PO(Rβ)-; and M is a proton, or other metal or non-metal cation, with the proviso that at least one of M is proton. The amount of dopant included in the polyaniline is not critical and may vary widely. In general, sufficient dopant is included such that the polyaniline is doped to the desired extent, usually an amount such that the polyaniline is doped to a conductivity of at least about 10^"β ohm~¹cm~¹. The amount of dopant employed is preferably sufficient to provide a conductivity of at least about 10~^βohm~¹cm~^L, more preferably at least about 10^"3ohm^"1cm^"1 and most preferably at least about lO^ohm^cm^"1. The doped polyaniline of this invention has many uses such as the formation of coatings, inks, films, articles and the like. The polyaniline of this invention is especially useful in the formation of the composition of this invention. Such composition comprises one or more of the polyanilines of this invention and one or more other organic or inorganic materials such as polymers, inorganic fillers and the like. In the preferred embodiments of the invention, the composition comprises one or more of the polyanilines in a matrix comprising one or more other electrically conductive or electrically non-conductive homopolymers or copolymers. The type of homopolymer or copolymer employed to form the polymer matrix may vary widely and any type can be used. Illustrative of useful polymers are electrically conductive and/or non-conductive thermoplastic and/or thermosetting polymers. Thermoset polymers for use in the practice of this invention may vary widely. Illustrative of such useful thermoset polymers are alkyds derived from the esterification of a polybasic acid such as phthalic acid and a polyhydric alcohol such as glycol; allylics such as those produced by polymerization of dialkyl phthalate, dialkyl isophthalate, dialky1 maleate, and dialkyl chlorendate; amino resins such as those produced by addition reaction between formaldehyde and such compounds as melamine, urea, aniline, ethylene urea, sulfonamide and dicyandiamide; epoxies such as epoxy phenol novolak resins, diglycidyl ethers of bisphenol A and cycloaliphatic epoxies; phenolics such as resins derived from reaction of substituted and unsubstituted phenols such as cresol and phenol with an aldehyde such as formaldehyde and acetaldehyde; polyesters; silicones; and urethanes formed by reaction of a polyisocyanate such as 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,6-hexamethylene diisocyanate and 4,4'-dicyclohexylmethane diisocyanate with a polyol such as polyether polyol (trimethylol propane, 1,2,6-hexanetriol, 2-methyl glycoside, pentaerythitol, poly(l,4-tetramethylene ether) glycol, sorbitol and sucrose); polyester polyols such as those prepared by esterification of adipic acid, phthalic acid and like carboxylic acids with an excess of difunctional alcohols such as ethylene glycol, diethylene glycol, propanediols and butanediols.

Thermoplastic polymers for use in the practice of this invention may vary widely. Illustrative of such thermoplastic polymers are polyesters such as poly(l,2-dimethylpropiolactone) , poly(pivaloyl lactone) , poly(para-hydroxybenzoate) , poly(ethylene oxybenzoate) , poly(ethylene terephthalate) , poly(l,4-cyclohexane dimethylene terephthalate) , and the like; polyamides such as poly (4-aminobutyric poly(6-a ino-hexanoic poly (ll-aminoundecanoic poly (12-aminododecanoic poly (hexamethylene adij

poly(hexamethylene sebacamide) , (nylon 6,10), poly(meta phenylene isophthalamide) (Nomex) , poly(p-phenylene terephthalamide) (Kevlar) , and the like; polycarbonates such as poly [methane bis (4 -phenyl) carbonate] , poly [ 1 , 1-ethane bis ( 4 -phenyl ) carbonate ] , and the like ; polymers derived from the polymerization of α ,3-unsaturated monomers such as polyethylene, aery lonitrile/ but adiene/styrene ter polymer, polypropylene, poly(4-methyl-l-pentene) , polyisobutylene, poly(isoprene) , poly (vinyl fluoride), poly (vinyl chloride), poly(vinylidene fluoride), poly(vinylidene chloride), poly(tetrafluoroethylene) (Teflon), poly (chlorotri- luoroethylene) , poly (methyl acrylate) , poly (methyl methacrylate) , poly- aery lonitrile, polyacryla ide, and the like; polydienes such as poly ( 1 , 3 -butadiene) (cis) , poly ( 1 , 3-butadiene) (trans), poly (1,3 -butadiene) (mixt.) , and the like; p o l y o x i d e s s u c h a s poly[2,2-bis(chloromethyl) -trimethylene-3-oxide] (penton) , poly(2,6-dimethyl-l,4-phenylenβ oxide) (PPO) , poly (2 ,6-diphenyl-l,4-phenylenβ oxide) (Texax, P30) , and the like; polysulphides such as poly (phenylene sulphide) and the like; polysulfones such as poly[4,4'-isopropylidene diphenoxy di(4-phenylene) sulphone]; noryl; and mixtures thereof. Preferred polymers are polymers formed from 1,2 unsaturated monomers such as polyolefins and polyvinyls, and other thermoplastic polymers such as polyesters, polyamides and polycarbonates .

The composition of this invention may include various optional components such as plasticizers, blending aids, colorants, flame-retardants and the like, or components which either fill or from a substrate for the composition to be cast from the melt or solution. These other components may vary widely and may include any material known for use in conventional polymer compositions. Illustrative of such other components are such materials as carbons, metal conductors, reinforcing fibers, inert fillers, glass beads, clays, other conductive and non-conductive polymers, conductive ceramics, super-conductive ceramics, and the like.

The composition of this invention can be prepared using conventional techniques as for example conventional melt or solution blending techniques. For example, such compositions can be formed by heating and mixing a mixture of the various components to a temperature which is equal to or greater than the melting point of flow point of at least one of the polymer components to form a molten intimate mixture to which optional components may be added as desired. Thereafter the mixture can be formed into a desired article through use of any conventional shape forming technique. For example, the molten mixture can be spread on a surface and allowed to cool forming free standing films or coatings. The molten mixture can be extruded through a die to form films or fibers, or injection molded into a suitable mold to form molded parts having the shape of the mold. The manner in which the molten mixture is formed is not critical and conventional methods can be employed. For example, the molten mixture can be formed through use of conventional polymer and additive blending means, in which the polymeric components are heated to a temperature equal to or greater than the melting point of at least one of the polymers, and below the degradation temperature of each of the polymers. Ultrasonication can be used to improve dispersion of the non-soluble phases. The desired amount of the optional ingredients in a liquid or powdered form is added to the melted polymers while at the same time vigorosly agitating the melt as for example by stirring or irradiating with ultrasound, or added prior to melting and mixing.

In a solution process for the preparation of the composition of this invention, a solution is formed of the desired host polymer and a desired polyaniline of this invention in a suitable solvent with or without a dopant solute. As used herein, "solutions" are pure solutions or dispersions of particles in which particle size is equal to or less than about 500 nanometers, preferably less than about 300 nanometers more preferably less than about 200 nanometers and most preferably less than about 100 nanometers. The desired optional components in the desired amounts may be dissolved or dispersed in the solution. The dissolved and/or dispersed polymers can be solidified into a desired shape by removal of the solvent through use of conventional techniques. For example, by removal of the solvent from a solution spread on a surface films can be formed of any desired thickness. By extruding the solution through a die, fibers and films can be made. Similarly, by removing the solvent from the solution in a mold, shaped articles conforming in shape to the mold can be prepard.

If the original solution did not include a suitable dopant, the shaped article can be exposed to a suitable dopant to dope the polyaniline. In the preferred embodiments of the invention, however, doped polyaniline is used to form the solution.

In the most preferred embodiment of the invention, the components of the intimate mixture can be granulated, and the granulated components mixed dry in a suitable mixer, as for example using ultrasonication or a tumbler or a Branbury Mixer, or the like, as uniformly as possible. Thereafter, the composition is heated and further mixed in an extruder when at least one of the polymers components is melted. As described above, the fluid mixture is thereafter ejected with cooling. The order of mixing of the various components of the intimate mixture may not be critical. Accordingly, the order of addition of the polymers and other optional components to be described in more detail hereinbelow, to form the initimate mixture, can be varied as desired.

The electrically conductive polyaniline of the invention, and the composition of this invention can be used for any purpose for which conductive polymers are useful. Examples of articles include conductive polymer housings for EMI Shielding of sensitive electronic equipment such as microprocessors; infrared, radio frequency and microwave absorbing shields; flexible electrical conducting connectors; conductive bearings and brushes; semiconducting photoconductor junctions; electrodes; capacitors; optically transparent or non-transparent corrosion-preventing coatings for corrodible materials such as steel; antistatic materials and optically transparent or non-transparent coatings for packaging electronic components; carpet fibers; waxes for floors in computer rooms; antistatic finishes for CRT screens, aircraft, and auto windows; and the like.

Various other applications are anticipated for the conducting coatings produced by the present processes, such as in conducting plastic gas tanks; solar window coatings; transparent electrical elements for heated windows and heated liquid crystal displays; electrochromic displays, electrical contacts for electroluminescent displays and electroluminescent lights, and electrical contacts for piezoelectric films for transparent loud speakers; transparent conducting coatings for windows in burglar alarm systems; membrane coatings for chemical separations (such as 0₂ and N₂, for example) ; and conducting coatings-for membrane switches; and a discharge layer or photoresist layer for lithographic process.

Specially useful coatings of conducting polymers are those which are transparent in the visible spectral region. By transparent in the visible region, it is meant that at least 30% of the solar energy spectrum in the visible region is transmitted by the coating. Since transparency is inversely related to conducting polymer thickness, a desired degree of transparency can be obtained by limiting the thickness of this layer, such as by limiting the amount of conductive polymer solution applied onto the surface of the substrates.

The following specific examples are presented to more particularly illustrate the invention, and should not be construed as being limitations on the scope of the invention.

To a solution containing 1770 mL of H₂0, 50 g of aniline(0.54 mole) and 172 g p-toluene sulfonic acid (0.90 mole) was added, dropwise at 15*C, a solution of ammonium persulfate (153.4 g in 336.5 mL H₂0) over a period of 40 minutes. After addition, the reaction was allowed to continue at 15^βC for a 0.5 hours. The resultant solid precipitate was collected and washed with 6 L of an aqueous toluene sulfonic acid solution (10 wt%) and then by 3 L of methanol. The resultant blue-black solid was dried in air for 25 hrs and dried at 130*C for 3 hrs. under dynamic vacuum to give poly(anilinium tosylate) as a green powder. The conductivity of the dried and pressed pellet formed from this material was 1 S cm~ as measured by the co-linear four-probe method. The conductivity of the moisture-saturated pellet was 20 S cm . The yield was 78g. The intrinsic viscosity (in concentrated H₂S0₄, at 25*C) was 0.66 dL/g. Elemental analysis of the dried green powder gave:

C:64.27( t%) H:4.86% N:8.59% S:8.40% 0:13.51%

Moisture: less than 0.8 wt% E AMP E _

Poly(anilinium tosylate) (13g) obtained from Example

1 was suspended in water at room temperature and nuetralized with excess sodium carbonate (Na_zC0₃) . The suspension was then filtered and the cake was dried to yield a blue-black powder of polyaniline base.

EXAMPLES 3 TO 6 AND COMPARATIVE EXAMPLES 1 AND 2 The neutral polyaniline obtained in Example 2 was then redoped with various different phosphorous- containing dopants by the following procedure. The neutral polyaniline (2 g) was suspended in 25 mL methanol containing 5 g of the corresponding phosphorous- containing acids and perfluorocarboxylic acids as listed in Table 1. The resulting solution was stirred for 20 hours. The solid was then collected and rinsed with 50 mL of methanol. after air-drying for overnight, the doped polyaniline was dried at 80 C under dynamic vacuum for 3 hours. The conductivities, listed in Table 1, were measured by a 4-in-line probe on a pressed pellet of about 1 cm diameter. The TGA (thermogravimetric analysis) of these doped polyanilines were performed by DuPont 9900 Thermal Analysis at a heating rate of 20* C/min from 25^*c to 900*C under an inert gas. The on-set temperatures corresponding to the loss of the dopant species of each doped polyanilines are summaried in Table 1. The results showed that all these phosphorous-containing dopant are thermally much more stable then carboxylic acids. TABLE 1

"a. Ruutts based on TGA (thβrmograviπntric analysis)

EXAMPLE 7 AND COMPARATIVE EXAMPLE 3

The polyaniline doped with methylenediphosphonic acid prepared in Examples 3 to 6 and comparative Examples 1 and 2 and the one doped with p-toluene sulfonic acid prepared in Example 1 were subjected to thermal stability study. The study was done by heating a pellet of the above two polyaniline compositions in a glass chamber under dynamic vacuum at 270 C° for 30 minutes. The conductivities of the pellet before and after heating were measured by a 4-in-line probe. The results, as summarized in the following tables, indicated that the thermal stability of the phosphonic acid doped polyaniline is much higher than that of the sulfonic acid doped polyaniline.

Claims

WHAT IS CLAIMED IS:

1. A thermally stable electrically conductive polyaniline comprising a polyaniline homopolymer or copolymer doped with an organic phosphorus acid.

2. A polyaniline according to claim 1 wherein the polyaniline comprises repeat units of the Formulas II, III or II and III:

wherein: n is an integer from 0 to 4; m is an integer from 0 to 4, with the proviso that the sum of n and m is 5;

R₁ is phosphinic acid or a salt or ester thereof, phosphonic acid or a salt or ester thereof, sulfonic acid or a salt or ester thereof, boric acid or a salt or ester thereof, phosphoric acid or a salt or ester thereof, alkylamino, dialkylamino, aryiamino, diaryiamino. alkylaryiamino, amino, hydroxy, sulfinic acid or a salt or ester thereof, nitro, carboxylic acid or a salt or ester thereof, halo, cyano, deuterium, or substituted or unsubstituted alkyl, aikenyl, alkoxy, cycioalkyl, cycloalkenyl, alkanoyl, alkylthio, alkynyl, dialkyiamino, arylamino, diarylamino, alkylaryiamino, aryloxy, hydroxy, alkylthioalkyl, alkylaryl, arylalkyl, aryloxy, amino, alkylthioalkyl, alkylaryl, arylalkyl, alkyisufinyl, alkoxyalkyl, alkylsulfonyl, aryl, arylthio, aryisulfinyl, alkoxycarbonyl, alkylsilane, or arylsulfonyl, wherein permissible substituents are one or more amino, alkyiamino, dialkyiamino, arylamino, diarylamino, phosphinic acid or a salt or ester thereof, alkylaryiamino, phosphonic acid or a salt or ester thereof, sulfonic acid or a salt or ester thereof, boric acid or a salt or ester thereof, sulfinic acid or a salt or ester thereof, phosphoric acid or a salt or ester thereof, carboxylic acid or a salt or ester thereof, halo, nitro, hydroxy, cyano or epoxy moieties; or any two R₁ substituents, or any one R, substituent and R₂ substituent taken together may form substituted or unsubstitued alkylene, alkynyiene or alkenylene chain completing a 3, 4, 5, 6, 7, 8, 9 or 10 membered aromatic, heteroalicyciic, heteroaromatic or alicyclic carbon ring, which ring may optionally include one or more divalent ester, carbonyl, nitrogen, sulfur, sulfinyl, sulfonyl or oxygen, wherein permissible substituents are one or more amino, alkyiamino, phosphinic acid or a salt or ester thereof, dialkyiamino, arylamino, diarylamino, alkylaryiamino, phosphonic acid or a salt or ester thereof, sulfonic acid or a salt or ester thereof, boric acid or a salt or ester thereof, sulfinic acid or a salt or ester thereof, phosphoric acid or a salt or ester thereof, carboxylic acid or a salt or ester thereof, halo, nitro, hydroxy, cyano or epoxy moieties, or R₁ is an aliphatic moiety having repeat units of the formula:

(OCH₂CH₂)_qO-CH₃, (OCH₂CH(CH₃))_qO-CH₃, (CH₂)_qCF₃, (CF₂)_qCF₃ or (CH₂)_q CH₃

wherein q is a positive whole number; and R₂ is the same or different at each occurrence and is hydrogen or substituted or unsubstituted alkyl group wherein permissible substituent is R,.

3. A composition according to claim 2 wherein said homopolymer or copolymer is comprised of the Formula IV:

x and y are the same or different at each occurrence and are integers equal to or greater than 0, with the proviso that the sum or x and y are greater than 0; z is an integer equal to or greater than about 1 ; n is an integer from 0 or 1 ; m is an integer from 3 or 4, with the proviso that the sum of n and m is 4;

R, is the same or different at each occurrence and is alkyl or alkoxy having from 1 to about 2 carbon atoms or a sulfonic acid function or a salt or ester thereof; and

R₂ is the same of different at each occurrence and is alkyl or hydrogen

4. A composition according to claim 3 wherein R₂ is hydrogen.

5. A composition according to claim 3 wherein:

R₁ is the same or different at each occurrence and is alkyl or alkoxy having from 1 to about 6 carbon atoms; x is an integer equal to or greater than 1 ; R₂ is hydrogen; y is equal to or greater than 0; and z is an integer equal to or greater than about 5.

6. A composition according to claim 10 wherein m is 4 and n is 0.

7. A composition according to claim 1 wherein said dopant is an organic phosphosphorus acid having a pKa less than that of said polyaniline.

8. A composition according to claim 7 wherein said dopant is an acid or acid derivative of the formula:

R₄(P0₂(R_β)M)_(P0₃M₂)_b{P0₂M₂)_c(PO(R_β)M)_d or

A-[-[-(X₁)_r(R₇)_Q-(X₂)_h-(R₉)-,]_i-(B)_j-]_lt-C

or

wherein:

M is H⁺, or other metal or non-metal cation with the proviso that at least one of M is H⁺ or a moiety which can be thermally or chemically transformed into a proton under process or use conditions; k is 0 or an integer from 1 to about 400; i is 0 or an integer from 1 to about 20;

A is a moiety of the formula:

-P0₂(R_β) or -P0₃M₂ or -P0₂M₂ B is the same or different at each occurrence and is moieties of the formula: -P0₂M-, or -POM-, or -P0R_-

C is -OM a, b, c and d are the same or different at each occurrence and are 0 or integers equal to or greater than 1 with the proviso that at least one of a, b, c or d is other than 0; e is 0, 1 , 2, 3 or 4; and f, g, h, and.j are the same or different at each occurrence and 0 or 1 ; R₄, R₅ and R_β are the same or different at each occurrence and are nitro, cyano, hydroxy, halo, amino, alkyiamino, dialkyiamino, arylamino, diarylamino, alkylaryiamino, alkoxy, or substituted or unsubstituted alkoxy, aryl or alkyl having from 1 to about 30 carbon atoms wherein permissible substituents include, perhaloalkyl, phenyl, alkoxy, halo, cyano, amino, haloalkyi, hydroxy, sulfonic acid or a salt or ester thereof, phosphoric acid or a salt or ester thereof, boric acid or a salt or ester thereof, sulfinic acid or a salt or ester thereof, phosphinic acid or a salt or ester thereof, phosphonic acid or a salt or ester thereof, carboxylic acid or a salt or ester thereof, nitro, or any two R₅, or any two R_β, or any R₄ and R_β substituents together may form an alkenylene chain completing a fused-ring system which chain may be unsubstituted or substituted with one or more halo, phosphoric acid or a salt or ester thereof, hydroxy, boric acid or a salt or ester thereof, nitro, cyano, amino, phosphinic acid or a salt or ester thereof, alkyiamino, dialkyiamino, arylamino, diarylamino, alkylaryiamino, sulfinic acid or a salt or ester thereof, phosphonic acid or a salt or ester thereof, sulfonic acid or a salt or ester thereof, or carboxylic acid or a salt or ester thereof, or R₄ or R₅ or R_β is a moiety of the formula:

-(CH₂)„CF₃, -(CF₂)_qCF₃, -(CH₂)_qCH₃ wherein: q is a positive whole number from 1 to about 10;

-(OCH₂CH₂)_qOCH₃ or -(OCH₂CH(CH₃))_qOCH₃ X. or X₂ are the same or different at each occurrence, and are the moieties of the formula: -O-, -S-, -OC(O)-, -(O)CO-, -S(0)₂-, -N(A)- , -O-S(O)₂-, -(0)₂S-0-, -N(R₈)-, -P(R₈)-

R₇ is substituted or unsubstituted alkylene, arylene or dialkylene arylene wherein the permissible substituent is R

9. A composition according to claim 8 wherein said dopants are acids and/or acid derivatives of the formula:

R₄(P0₂(R_β)M).(P0₃M₂)_b or

wherein: a, and b are the same or different and are 0, 1 or 2 with the proviso that at least one of a or b is not 0;

A is moiety of the formula: -P0₂(R_β)M or -P0₃M₂;

B is -P0₂M- or -POM-, -PO(R_β)-

C is OM

e is 0, 1 or 2; f, g, h and; are the same or different and are 0 or 1 ; f_r g, h and j are the same or different and are 0 or 1; k is an integer from 1 to about 200, i is an integer from 1 to about 10,

R₄ and R₅ are the same or different at each occurrence and are alkyl, phenyl, amino, alkyiamino, dialkyiamino, arylamino, diarylamino, alkylaryiamino, or alkyl substituted with one or more fluoro, phosphonic acid or salt or ester thereof, sulfonic acid or a salt or ester thereof, alkoxy, hydroxy, nitro, cyano, phosphinic acid or a salt or ester thereof, amino, or carboxylic acid or a salt or ester thereof, or phenyl substituted with one or more alkyl, alkoxy, f luoroalkyl, phosphonic acid or a salt or ester thereof, sulfonic acid or a salt or ester thereof, phosphinic acid or a salt or ester thereof, hydroxy, nitro, cyano, or carboxylic acid or a salt or ester thereof, or any two R₅ substituents together may form an alkylene or alkenylene chain completing a naphthalene, anthracene or phenanthrene fused system which may be substituted with one or more alkyl, alkoxy, fluoro, phosphonic acid or a slat or ester thereof, phosphinic acid or a salt or ester thereof, fluoroalkyi, sulfonic acid or a salt or ester thereof, carboxylic acid or a salt or ester thereof hydroxy, nitro, amino or cyano groups;

R_β is hydrogen, aryl, aryloxy, alkyl or alkoxy; and

R₇ is alkylene, arylene or dialkylenearyiene; and

M is H⁺ or other metal or non-metal cation, with the proviso that at least one of M is H⁺ or is a moiety which can be thermally transformed into a proton under process conditions.

10. A composition according to claim 9 wherein said dopant is a phosphorous acid of the formula: R₄(P0₃M₂)_b(P0₂(R_β)M). or

wherein; c is 1 , 2 or 3; e is 0, 1 or 2; R₄ is alkyl or alkoxy; R_β is hydrogen or alkyl; R_s is hydroxy, alkyl or alkyl substituted with one or more fluoro, or any two R₅ groups together may form an aikenyiene chain completing a naphthalene fused system which may be substituted with one or more sulfonic acid or a salt or ester thereof, hydroxy, and M is a proton, or other metal or non-metal cation, with the proviso that at least one of M is a proton.