DE1644994B2 - MANUFACTURE OF ELECTRICALLY CONDUCTIVE COATINGS ON THE SURFACE OF PLASTICS - Google Patents

Description

NC S.

Me

C.
Il
C.

S CN

The invention relates to the use of bis (1,2-dicyanethylene-1,2-dithiolo) metal salts for the production of electrically conductive coatings on plastic surfaces.

Electrically conductive coatings or patterns are often found on the surface of plastic bodies applied, for example to dissipate electrostatic charges that form due to friction. at the production of printed circuits on a base body made of a plastic one brings z. B. by brushing on, spraying on or printing on an electrical corresponding to the desired circuit diagram luminous surface pattern.

For the production of such electrically conductive coatings or surface patterns, electrical ones are usually used Conductive lacquers, which are made from a solution of a binder in a solvent and metal powders suspended in it exist. In the production of such conductive lacquers, one has to pay close attention to the proportions of the individual If you want the paint to adhere well to each other, pay attention to their quality Wants to achieve a base with good conductivity at the same time.

It is known (H. A. Fo h 1 in Electrical Conduction Properties of Polymers, No. 17, pp. 13-40, from Journal of Polymer Science, Part C, Polymer Symposia) that numerous organic polymers, ζ. Β. Polybenzimidazoles, Polyphenylenes, polynaphthalenes, etc. represent semiconductors. Taking advantage of these properties of the However, the polymers mentioned has not yet taken place on a larger scale, as they are due to their Difficult or insoluble cannot be brought into the desired application form in a simple manner can. .

The invention was based on the object of finding connections that, in addition to a good electrical Conductivity at the same time have the property to adhere well to plastic surfaces and in a simple way Way can be brought into the desired application form.

It has now been found that this object can be achieved by using bis- (l, 2-dicyanethylene-1,2-dithiolo) -in the Me is a divalent transition metal of subgroups I to VIII of the periodic table and K is one or more counter cations, in the production of electrically conductive coatings Plastic surfaces can be solved.

The production of the metal salts mentioned, which is not claimed in the context of the present application is known and, for example, by G. BÄ r and G. S c h 1 e i t ζ e r in the Chem. Ber "90,438 (1957) or in US Pat. No. 3,255,195.

Metal ions or ammonium, sulfonium, arsonium, phosphonium, Stibonium, selenonium or telluronium ions in Consideration in which the hydrogen atoms are wholly or partially replaced by alkyl or aryl radicals with up to 20 C atoms can be replaced. Preferred countercations are metal ions, which also solvate or can be hydrated.

The solvated ones are particularly suitable as counterions or hydrated ions

2H ⁺ -2H2O, 2Ag ⁺ · 2H2O, Ag + [N (CH3> t] ⁺ ,

Cu ²⁺ -2 H2O, Cu ²⁺ H2O,

Cu ² + pyridine-CHaOH,

Ni ²⁺ 2 dimethylformamide, Ni ²⁺ ■ H2O,

Co ²⁺ · 2H ₂ O ₁ Co ²⁺ · H2O.

Salts to be used according to the invention are preferably those with copper, zinc, zirconium, vanadium, Chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, palladium and platinum as the divalent central atom into consideration.

As previously unknown, these compounds not only have good electrically conductive properties also the property of being in aprotic solvents, e.g. B. pyridine and its derivatives, formamide, Hexamethylphosphoric acid triamide and tetramethylurea and especially also in dimethylformamide, Dissolve N-methylpyrrolidone and dimethyl sulfoxide. So they can be compared to the previously known organic polymeric semiconductors in a simple manner to those with an electrically conductive coating providing plastic surfaces, e.g. B. by brushing or spraying, apply. Surprisingly they form there after removal of the solvent, for. B. by evaporation, a contiguous Film that adheres well to the plastic surface. They adhere particularly well to plastics such as Vinyl resins, e.g. B. polyvinyl chloride, polyacrylonitrile, polyvinyl chloride and their copolymers, also on polyesters, Polyamides, polycarbonates and polymers based on styrene. You have the further advantage that they are stable to the effects of heat. Depending on the counter cation, their decomposition range is at about 200 to 300 ° C. Their resistance is largely independent of temperature.

The following table shows the conductivity values, t [Ω - 'cm -' 1 measured at SOO "K, (measuring method according to G. Manecke, D. Wöhrle, Makromolekulare Chemie. 102, [1967], p. 8), different bis - (U-dicyanithylene-1,2-dithiolo) metal salts listed In this table, A denotes the anion, for the sake of simplicity only illustrated by the central atom Me, and K the counter cation.

A [Me] K

Cu 2- 2- = Hz ⁺ - 2H2O 1.8 · ΙΟ " ⁵ Cu 2- 2- Ql ^{2 +} 2H2O 7.8 × 10 ⁶ Cu 2- 2- Ni ²⁺ 2DMF 1.6 - ΙΟ- ⁴ Cu 2- 2- Ni ^{2 +} · H2O 1.1 · ίο- · * Ni] ² " DMF = Cu ² + · H2O 5.0 x 10- ² Ni] ² - Py Cu ²⁺ Py-CH3OH 5.6 · ΙΟ " ² Cu Co ² + H2O 3.7 10- * Co Cu ² + ■ 2H2O u · 10- ⁵ Co Cu ²⁺ Py-CH3OH 23 · ίο- ⁶ Co; Co ²⁺ H2O 83 ΙΟ- ⁶ Dimethylformamide Pyridine.

NC

CNI ²

Ni

Il c

NC

CN

The parts given in the examples are parts by weight, unless otherwise stated. Parts by weight relate to parts by volume like g: ml.

example 1

For the production of copper bis (1,2-dicyanäthylenl, 2-dithiolo) nickelate

admitted. The dark brown precipitate is washed after 12 hours Filtered well with water, dried at 6O ⁰ C and then thoroughly washed with water. It is then dried in vacuo at 80 ° C. over P2O5. The substance is then dissolved in pyridine, filtered and reprecipitated with methanol. The salt is obtained in almost quantitative yield based on the disodium dimercaptomaleic dinitrile used.

2 parts of this salt are dissolved in 20 parts of dimethylformamide and brushed onto a polyethylene terephthalate film. After drying, a firmly adhering film of nitrile remains on the surface with a thickness of 1 to 2 μ. Its surface resistance, measured with an ohmmeter, is 2 · 10 ^{5 OhIn at 25 or 80 ° C.}

Example 2

For the production of copper bis (1,2-dicyanethylene-1,2-dithiolo) cuprate-II

Cu ²⁺
pyridine-CH ₃ OH

becomes a solution of 1.86 parts of disodium dimercaptomaleic dinitrile in 50 parts of water with good stirring dropwise with a solution of 1.188 parts NiCb · 6H2O in 20 parts of water were added. The clear, deep red solution is filtered and then added dropwise a solution of 1.25 parts of copper sulfate (CuSO4 · 5H2O) in 20 parts of water with stirring

NC

C. C.

Cu

NC

S.
\ Cu ^{2 +}
2H ₂ O /
S. \ /
C.
Il
C.
/ \ CN
/ \
CN

1.86 parts of disodium dimercaptomaleic acid dinitrile are dissolved in a mixture of 50 parts by volume of methanol and 100 parts by volume of water. A solution of 2.5 parts of copper sulfate (CuSO ₄ · 5H2O) in 30 parts by volume of water is slowly added to this solution with thorough stirring. The thick solution is diluted with a further 100 parts by volume of water. To improve the precipitation of the substance, 1 part of CuSO ₄ · 5H2O is added. After 12 hours the dark precipitate is placed on a folded filter, washed well with water, dried at 6O ⁰ C, well-washed again and dried at 80 ° C in vacuo over P2O5. The salt is obtained in a yield of 91% of theory, based on the disodium dimercaptomaleic acid dinitrile used.

2 parts of the salt are dissolved in 20 parts of N-methylpyrrolidone and painted onto a polyamide film. After drying, a firmly adhering film of nitrile remains on the surface with a thickness of 1 to 2 μ. Its surface resistance measured with an ohm meter, is from 10 ⁶ Ohm at 25 to 8O ⁰ C.

Claims (1)

NC \ / S. \ S. \ / S. / S. \ / CN / CN C. Me C. Il / \ Il C. \ C. / \ / \ \ NC 2- in the Me a divalent transition metal of subgroups I to VIII of the periodic table represents, and K means one or more counter cations, for the production of electrically conductive Coatings on plastic surfaces. Claim: Use of bis (1,2-dicyanethylene-1,2-dithiolo) metal salts the general formula metal salts of the general formula NC S S. CN Il c