mixtures thereof. which is fluid during compounding or mixing with (i) and (ii) and/or during shaping into the conductive article. 

SU1prisingly. the inventors have discovered that. unlike the electrically conductive compositions described in the prior art. the materials according to the present invention, which do not contain an excess protonic acid, 

i. display outstanding processability in the fluid form. i.e. solution or melt; 

ii. are substantially less acidic; and 

iii. are less hygroscopic; and. in addition, in blends with insulating or semiconducting matrix polymers: 

iv. exhibit improved compatibility between the conduct› ing polyaniline salt complex and the matrix material; which results in 

v. a remarkably low percolation threshold for the onset of conductivity. 

Furthermore. the inventors have discovered extremely unusual crystalline solvates of electrically conductive polya› niline salt complexes and substituted aromatic compounds. The latter compositions are remarkable in that they exhibit novel crystal structures that are different from either of their constituents; and have controllable melting temperatures. The Electrically Conducting Polyaniline 

One ingredient in the present compositions is electrically conducting unsubstituted or substituted polyaniline salt complexes or an electrically conducting polyaniline copoly› mer salt complex, or mixtures thereof, as described in U.S. Pat. Nos. 5.069.820 and 5.160.457 and U.S. Pat. No. 5.232. 631. When the term "electrically conducting polyaniline salt complex" is used in this application. it is used generically to include electrically conducting unsubstituted and substituted polyanilines and electrically conducting polyaniline copolymers. and mixtures thereof. that have been rendered electrically conducting by protonation of the corresponding non-conducting forms of polyanilines by the use of one or more strong protonic acids with a pKa value of less than about 3.0; unless the context is clear that only the specific nonsubstituted form is intended. 

The non-conducting polyaniline used for the preparation of the electrically conductive polyaniline salt complexes according to practice of this invention can be in any of its physical forms. lliustrative of useful forms are those described in U.S. Pat. Nos. 5.232.631 and 4.983.322. incor› porated by reference herein. For unsubstituted polyaniline. useful forms include leucoemeraldine, protoemeraldine, emeraldine. nigraniline and pernigraniline forms. Useful polyanilines can be prepared by any chemical and electro› chemical synthetic procedures referred to, for example. in the above references incorporated herein. 

In general. the non-conducting forms of polyanilines useful for the preparation of the electrically conductive polyaniline salt complexes used in practice of this invention are those which are of sufficiently high molecular weight to exhibit high electrical conductivity; i.e .• those polyanilines having a weight average molecular weight of more than 5.000 daltons. In general substituted and unsubstituted polyanilines and polyaniline copolymers will be of at least 20 repeat units. In the preferred embodiments of the invention. the number of repeat units is at least about 25. and in the most preferred embodiments. the number of repeat units is at least about 50. 

Particularly preferred for the use in the practice of this invention. is the electrically conducting polyaniline that is derived from the non-conducting unsubstituted polyaniline and protonated to its electrically conducting form by the use 

of one or more protonic acids that have a pKa value of less than about 3.0. Preferred protonic acids are those that protonate the polyaniline to form a salt complex. having an electrical conductivity of greater than about 10-6 Siem. Among the preferred protonic acids. particularly preferred are those that belong to the class of acids that impart a conductivity of greater than about 10- 3 Siem to the salt complex with polyaniline. Amongst these particularly pre› ferred embodiments. most preferred are those embodiments in which said polyaniline salt complex has a conductivity greater than about 1 Siem. 

Protonic acids are well known as dopants in the conduc› tive polymer art as shown by the reference to J. C. Chiang and A. G. MacDiarmid; the reference to W. R. Salaneck et al and to U.S. Pat. Nos. 5.069.820 and 5.232.631. 

The Substituted Aromatic Compound 

A second. critical ingredient of the compositions of the present invention is one or more particular substituted aromatic compounds. The unique roles of this substance are that of a "solvent-plasticizer" of conductive polyaniline complexes; and. additionally. of "compatibilizer" in blends of the conductive polymer with insulating or semiconductive polymers or prepolymers. 

Unlike commonly used plasticizers. which in the art of conductive polymer processing often are added to improve dispersion of solid conductive particles in molten polymers, the substituted aromatic compounds used according to the present invention. during processing dissolve the electrically conductive polyaniline salt complexes. and form strong molecular associations with them. Due to this unique feature. the conductive polyaniline salt complexes during processing are in their fluid form. which has the above described major advantages with regard to product homogeneity. properties, and shaping options. And. unlike commonly used solvents. the substituted aromatic com› pounds according to the present invention form a permanent and integral part of the compositions. Interestingly, and Slllprisingly. the molecular interactions between the substi› tuted aromatic compounds and the electrically conductive polyaniline salt complexes may be so strong •. that their mixtures can form the extraordinary class of materials known as crystalline solvates. These materials exhibit novel crystalline structures that are different from each of their constituent. and have many useful properties, such as con- trollable melting temperatures. In addition. depending on the specific properties of the substituted aromatic compounds. such solvates may exhibit unusual electrical, optical mag› netic and mechanical characteristics. 

The second important role of the substituted aromatic compounds of the present invention is that of a "compati› bilizer" in blends of the conductive polyaniline complexes and insulating or semiconductive polymers or pre-polymers. The designation "compatibilizer" hereinafter refers to a species that improves the interaction between two immis- cible liquid phases through close matching of the physio› chemical nature of the species and the two liquids. Thus, for example. common surfactants reduce the interfacial tension of water and oil. and. therewith "compatibilize" these two liquids. as it is understood in this invention. This compati- bilizing is achieved in this simple example by providing a species (the surfactant) that has two covalently bonded moieties: one of which that strongly interacts with water; and the other moiety that has a favorable interaction with oil. The compatibilizing role of the substituted aromatic com- pounds according to the present invention in blends of the conducting polyaniline complexes and insulating or semi› conductive polymers is similarly understood. For example. 

