KR960002488B1 - Process for continuous coating of wires and use of the wires obtained therefrom - Google Patents

Abstract

Process for coating wires with an insulating lacquer based on polyesterimide, polyester or polyurethane. The lacquer may be 1) a polyesterimide or polyester wire lacquer containing a) 2 to 20 parts by weight of electrically conductive soot or b) 50 to 110 parts by weight of graphite or c) 1 to 12 parts by weight of soot and 50 to 110 parts by weight of graphite, or 2) a polyurethane wire lacquer containing a) 5 to 50 parts by weight of electrically conductive soot or b) 2 to 40 parts by weight of graphite or c) 1 to 35 parts by weight of soot and 2 to 115 parts by weight of graphite, or 3) a polyamide-imide wire lacquer containing a) 1 to 10 parts by weight of electrically conductive soot or b) 60 to 110 parts by weight of graphite or c) 1 to 10 parts by weight of soot and 60 to 110 parts by weight of graphite, all quantities being referred to 100 parts by weight of binder.

Description

How to continuously coat wires and how to use the resulting wires

The present invention,

Iii) the wire is first covered with insulating paint to produce a continuous, non-processed insulating coating on the surface of the wire, and

Ii) The method for continuous coating of the wire is characterized by a method of attaching the insulating film to another electrically conductive coating by coating the insulating wire produced by the method of step (i) with an electrically conductive paint.

In addition, the present invention relates to a wire produced according to the method and a method of using the wire as an energy-storing inductive winding.

Energy storage induction winding made of round wire made of an electrically conductive material such as copper, aluminum, etc., energy storage induction winding made of uniform, non-process, concentric coating of insulating paint attached to the wire surface, and the dielectric film Energy-saving induction windings made of attached electrically conductive coatings are already described in DE-A-3,604,579. However, according to the description of DE-A-3,604,579, the conductive coating is produced by attaching a thin metal layer. This has the disadvantage of being expensive in installation and requiring a time consuming method, for example a steaming of the metal layer under vacuum. In particular, the metal layer cannot be attached using a conventional wire sheathing device, so if the coated wire manufacturer wants to produce this type of winding wire, he must make additional investment.

In addition, the metal layer tears when the wire is stretched in the coil forming machine, so that the metal layer becomes unreliable in the processing of the winding wire.

In addition, US-A-3,660,592

Iii) the wire is first covered with insulating paint to produce a continuous, nonporous insulating coating on the wire surface, and

Ii) In another electrically conductive film, a method for continuously covering the wire is described by a method of attaching the insulating film by coating the insulating wire produced by the method of step (i) with an electrically conductive paint. In this method, the polyimide-based insulating paint is attached directly to the wire surface. Graphite dispersions or paints based on fluorocarbon hydrocarbon resins as binders composed of 0.5 to 75% by weight of graphite based on fluorocarbon hydrocarbon resins are attached to the insulating film.

The method of US-A-3,660,592 has the disadvantage that graphite-containing paints based on fluorinated hydrocarbon carbide resins cannot be applied to wire coating methods by standard painting machines. Another problem arises in the further processing of the sheathed wire. Thus, for example, the coil former must be fitted to the sheathed wire. In addition, the problem arises in particular by using thin wires (wire diameter <0.35 mm) which are not capable of tin-plating the fluorocarbon-hydrocarbon-based paints. This means that the paint coat must be removed before soldering the wires, which causes significant problems, especially by using thin wires. Finally, the high price of fluorinated hydrogen carbide resins represents a significant economic disadvantage.

An object of the present invention is characterized in that the insulating paint and the conductive paint can be attached and cured to wires of various diameters, in particular thin wires (diameter <0.35 mm) by a standard wire coating machine,

Iii) the wire is first covered with insulating paint to produce a continuous, non-processed insulating coating on the surface of the wire, and

Ii) Another electrically conductive film is to provide a method for continuously covering the wire as a method of coating the insulating wire produced according to the method of step (i) with an electrically conductive paint and attaching it to the insulating film. The wire produced according to the method is suitable for use as winding wire for the manufacture of coils, relays, motors and other electrical devices, for example.

In addition, the winding wire should be able to be processed according to conventional methods.

For wires produced according to the above method which would be suitable for use as winding wires, it is required that the insulation and electrically conductive coatings be sufficiently stretchable so that the coatings will not break even if the wires are broken. On the other hand, however, the coating must be hard enough to withstand the mechanical stress in the production of the coils and the like.

The inventors have surprisingly found that the object

Iii) the wire is first covered with insulating paint to produce a continuous, non-processed insulating coating on the surface of the wire, and

Ii) A method for continuously covering a wire as a method of attaching the insulating film to another electrically conductive film by coating the insulating wire produced according to the method of step (i) with an electrically conductive paint.

A) Insulation paint attached directly to the wire surface

a) the hydroxyl value of the polyester imide is 50-200 mg KOH / g, and a 20-60 wt% solution of the polyester imide in the organic solvent has a viscosity of 80-15,000 mPas at 23 ° C., Polyester imide and ear paint composed of a solvent solution, an aqueous solution or an aqueous acid solution of a polyester imide resin,

b) a polyester having a ratio of hydroxyl to carboxyl groups of 1.1: 1 to 2.0: 1, and a 20 to 60 wt% solution of polyester in an organic solvent having a viscosity in the range of 40 to 12,000 mPas at 23 ° C. Polyester wire paint, consisting of a solvent solution or an aqueous solution of an ester resin,

c) a solvent having a solvent solution of a diisocyanate (free isocyanate is completely blocked) and a polyol adduct made from an NCO / OH equivalent ratio of 1: 2 to 9: 1 and a OH value of 100 to 450 mg KOH / g. Polyurethane wire paint, consisting of a solvent solution of a siloxane-containing polyester, or

d) 20 to 40% by weight solution of polyamide imide is selected from the group of polyamide imide wire paints consisting of a solvent solution of polyamide imide having a viscosity in the range of 800 to 3,000 mPas at 23 ° C.,

B) The electrical paint attached to the insulated wire

e) conductive wire paint

1) 2 to 20 parts by weight of conductive carbon black per 100 parts by weight of polyester imide resin or polyester resin,

2) 50 to 100 parts by weight of graphite per 100 parts by weight of polyester imide resin or polyester resin, or

3) Polyester imide wire paint produced by adding a combination of 50 to 100 parts by weight of graphite and 1 to 12 parts by weight of conductive carbon black, based on 100 parts by weight of polyester imide resin or polyester resin in each case. (Aa) or polyester wire paint (Ab),

f) conductive wire paint

1) 5 to 50 parts by weight of conductive carbon black per 100 parts by weight of polyurethane resin,

2) 2 to 40 parts by weight of graphite per 100 parts by weight of polyurethane resin, or

3) a polyurethane wire paint (Ac) produced by adding a combination of 2 to 115 parts by weight of graphite and 1 to 35 parts by weight of conductive carbon black, in each case based on 100 parts by weight of polyurethane resin, or

g) conductive wire paint

1) 1 to 10 parts by weight of conductive carbon black per 100 parts by weight of polyamide imide resin,

2) 60 to 100 parts by weight of graphite per 100 parts by weight of polyamide imide resin, or

3) from the group of polyamide wire paints (Ad) produced by adding a combination of 60 to 110 parts by weight of graphite and 1 to 10 parts by weight of electrically conductive carbon black, in each case based on 100 parts by weight of polyamide imide resin It was found that this is accomplished by being characterized.

Polyester imide resins used as component (Aa) are known and are described, for example, in DE-A-1,445,263 and DE-A-1,495,100. The preparation of the polyester imide is carried out by esterifying (reacting) the polyhydric carboxylic acid with a polyhydric alcohol using an imide group containing starting material in the presence or absence of hydroxycarboxylic acid according to known methods. It is also possible to use reactive derivatives thereof in place of the free acid and / or alcohol. It is preferable to use terephthalic acid as the carboxylic acid component and to use ethylene glycol, glycerol and tris-2-hydroxyethyl isocyanurate as the polyhydric alcohol, and to use tris-2-hydroxyethyl isocyanurate. Is particularly preferred. Using tris-2-hydroxyethyl isocyanurate raises the softening temperature of the resulting paint film.

A starting material containing an imide group may comprise, for example, a compound consisting of at least one 5-membered ring carboxylic anhydride group and at least one additional functional group consisting of at least one additional functional group in addition to the primary amino group. Can be obtained by reaction with other compounds. Additional functional groups refer to primary carboxylic acid groups or hydroxyl groups, but may also refer to additional amino groups or carboxylic acid anhydride groups.

Examples of compounds consisting of cyclic carboxylic anhydride groups and further functional groups include pyromellitic dianhydride and trimellitic anhydride. However, other aromatic carboxylic anhydrides such as naphthalene tetracarboxylic dianhydride or dianhydride of tetracarboxylic acid containing two benzene centers in the molecule are also suitable, wherein the carboxylic acid groups are 3,3 ', 4 And 4 'position.

Examples of compounds consisting of primary amino groups as well as further functional groups include, in particular, diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, other aliphatic diprimary diamines. Also mentioned are diprimary diamines such as bezidine, diaminodiphenylmethane, diaminodiphenylketone, diaminodiphenylsulfone, diaminodiphenyl sulfoxide, diaminodiphenyl ether and diaminodiphenyl thioether , Diphenyls containing three benzene centers in the molecule as well as phenylenediamine, toluylenediamine, and xylenediamine, such as bis (4-aminophenyl)- - '-p-xylene or bis (4-aminophenoxy) -1,4-benzene and fully cycloaliphatic diamines such as 4,4'-dicyclohexylmethanediamine. In addition, other compounds containing amino groups and additional functional groups that can be used include amino alcohols such as monoethanolamine or monopropanolamine, as well as aminocarboxylic acids such as glycine, aminopropionic acid, aminocaproic acid or aminobenzoic acid. Can be mentioned. To prepare polyester imide resins, known transesterification catalysts can be used, for example organic acids, such as p-toluenesulfonic acid, as well as salts of heavy metals such as lead acetate, zinc acetate, organotitanates and cerium compounds Can be mentioned. The transesterification catalyst as described above may be preferably used as a crosslinking catalyst in curing the polyester imide in an amount of 3% by weight or less based on the amount of the binder.

In the preparation of polyester imide wire paints, suitable solvents include cryogenic and noncresol-based organic solvents such as crasol, phenol, glycol ethers such as methyl glycol, ethyl glycol, isopropyl glycol, butyl glycol, methyl diglycol, Ethyl diglycol, butyl diglycol; Glycol ether esters such as methyl glycol acetate, ethyl glycol acetate, butyl glycol acetate and 3-methoxy-n-butyl acetate; Cyclic carbonates such as propylene carbonate; Cyclic esters such as r-butyrolactone as well as dimethylformamide and N-methylpyrrolidone. Other solvents that may be used include aromatic solvents, which may be used alone or in combination with each other. Examples of the solvent include xylene and solvent naphtha. , Toluene, Ethylbenzene, Cumene, Industrial Benzol, Solveso of various types And celsol As well as deasol Can be mentioned.

Furthermore, an aqueous polyester imide solution or dispersion according to the process of the invention can also be used. For example, as described in DE-A-1,720,321, a water soluble or water dispersible polyester imide is produced by introducing a sufficiently high number of carboxyl groups in a polyester imide resin and neutralizing the carboxyl groups with amines. do.

The viscosity of the polyester imide 20-60 wt% solvent solution is 80-15,000 mPas at 23 ° C.

The polyester resins used as component (Ab) are likewise known and are described, for example, in US-A-3,342,780 and EP-B-144,281. The preparation of the polyester is carried out by esterifying (reacting) the polyhydric carboxylic acid with the polyhydric alcohol in the presence of a suitable catalyst according to known methods.

Instead of free acids, ester-forming derivatives thereof can also be used.

Examples of alcohols suitable for preparing polyesters include ethylene glycol, 1,2- and 1,3-propylene glycol, 1,2-, 1,3- and 1,4-butanediol, 1,5-pentanediol, neo Pentyl glycol, diethylene glycol, triethylene glycol as well as triols such as glycerol, trimethylolethane, trimethylolpropane and tris-2-hydroxyethyl isocyanurate. Preference is given to using a mixture of ethylene glycol and tris-2-hydroxyethyl isocyanurate. The use of tris-2-hydroxyethyl isocyanurate results in a paint film with elevated softening temperatures.

Examples of suitable carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, as well as esterifiable derivatives thereof, such as anhydrides of these acids and lower alkyl esters of the mentioned acids, such as methylethyl, propyl, butyl, amyl, nuclear chamber and Octyl phthalate, terephthalate and isophthalate. Half-esters, dialkyl esters and mixtures of these compounds may be used as the corresponding acid halides of the compounds.

The amount of each component is chosen in such a way that the polyester has a hydroxyl to carboxyl group of 1.1: 1 to 2.0: 1, preferably 1.15: 1 to 1.60: 1.

Suitable catalysts used in the preparation of the polyesters in amounts of 0.01 to 5% by weight, based on the mixture used, are conventional esterification catalysts. Examples of suitable compounds have already been mentioned in the description of the polyester imide (Aa).

Likewise, suitable solvents for the polyesters (Ab) are mentioned in the description of the polyester imides. The viscosity of the polyester 20-60 wt% solvent solution is 40-12,000 mPas at 23 ° C.

The polyurethane-based wire paints (Ac) used in the process according to the invention are likewise already known and are described, for example, in DE-A-2,840,352 and DE-A-2,545,912. The preparation of the wire paint is carried out in a cresol-based or non-cresol-based solvent, or in a mixture of solvents according to known methods, having a OH value of 100-450 mg KOH / g, preferably 150-400 mg KOH / g. This is accomplished by dissolving the siloxane-containing polyester and blocked isocyanate addition product.

Reactants (polyols and polycarboxylic acids) and the same reaction conditions as used in the preparation of the polyester wire paints (Ab) can be used to prepare hydroxyl-containing polyesters.

The isocyanate addition product is prepared by reacting diisocyanate with a polyol and the amount of the compound is selected in such a way that the NCO: OH equivalent ratio is 1: 2 to 9: 1. Residual free isocyanate groups of the adduct are reacted with blocking agents.

However, it is also possible to first react the isocyanate with the blocking agent and then to react the remaining free isocyanate groups with the polyol.

The synthesis of isocyanate addition products is inert to isocyanate groups at temperatures between 30 and 120 ° C. and in the presence of catalysts, but it is advantageous to carry out in solvents with good solvation when polyurethanes are formed.

Examples of suitable diisocyanates include trimethylene diisocinate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, propylene diisocyanate, ethyl ethylene diisocyanate, 2,3-dimethyl ethylene diisocyanate, 1-methyltrimethylene Diisocyanate, 1,3-cyclopentylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,2-cyclohexylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate , 2,5-toluylene diisocyanate, 2,6-toluylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,4-naphthalene diisocyanate, 1-isosia Nato-methyl-5-isocyanato-1,3,3-trimethylcyclohexane, bis (4-isocyana tocyclohexyl) methane, bis (4-isosia Sat phenyl) may be mentioned methane, 4,4'-diimide SOCIETE Ana Todi ether and 2,3-bis (8-isocyanatomethyl Ana took butyl) -4-octyl-5-hexyl chloride embodiment hexene.

Preference is given to using toluylene diisocyanate and bis (4-isocyanatophenyl) methane.

Examples of suitable polyols for forming the adducts include trimethylolpropane, neopentyl glycol, glycerol, hexanetriol, pentaerythritol and glycols such as ethylene glycol and propylene glycol. Preference is given to using trimethylolpropane. Particular preference is given to using addition products obtained from 1 mole of trimethylolpropane and 3 moles of toluylene diisocyanate and / or bis (4-isocyanatophenyl) methane.

Certain known blocking agents are suitable for blocking the free isocyanate groups, provided that deblocking takes place at temperatures above 120 ° C. Examples of suitable compounds include aliphatic, cycloaliphatic or aromatic alcohols such as butanol, isobutanol, 2-ethylhexanol, cyclohexanol, cyclopentanol, benzyl alcohol, phenol, cresol; β-hydroxyalkyl ethers such as methyl, ethyl, butyl glycol; Amines such as di-n-butylamine; Oximes such as methyl ether ketoxime, diethyl ketosim; Hydroxyamines and lactams such as ε-caprolactam as well as other compounds consisting of reactive hydrogen atoms, where the reactivity of the hydrogen atoms reacts the blocking agent with isocyanates.

Phenols and / or cresols are preferred blocking agents.

Examples of suitable inert solvents are heterocyclic, aliphatic or aromatic hydrocarbons, ethers, esters and ketones, such as N-methylpyrrolidone, toluene, xylene, cresol, ethylbenzene, solvent naphtha , Industrial benzol, various types of Solvesso And celsol , Deasol , Methyl diglycol, ethyl diglycol, butyl diglycol, ethylene glycol dibutyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, cyclohexanone, methyl ethyl ketone, isophorone, methyl glycol acetate, ethyl glycol acetic acid Salts, butyl glycol acetate and mixtures thereof.

The content of blocked isocyanate adduct in the wire paint (Ac) is 30 to 90% by weight, based on the total weight of the blocked isocyanate adduct and the hydroxyl-containing polyester.

If thin wire ( Polyurethane-based wire paint is preferably used as the insulating paint, in particular as the electrically conductive paint, if &lt; 0.35 mm) is coated. Polyurethane-based wire paints have the advantage of being directly solderable / tin plateable and have a low viscosity at high solids content. This is particularly advantageous for attaching at high speeds and for incorporating a maximum amount of carbon black.

Furthermore, polyurethanes as conductive paint have the advantage that they can be removed from some of the wires by simply melting when they are attached to the polyester or polyester imide insulating paint. This is important if, for example, one wishes to connect a copper wire conductor without connecting it with a conductive paint film.

The viscosity of the 15 to 50% by weight solution of polyurethane is 50 to 10,000 at 23 ° C.

Likewise, polyamide imide-based wire paints (Ad) are known and are described, for example, in US-A-3,554,984, DE-A-2,441,020, DE-A-2,556,523, DE-B-1,266,427 and DE-A-1,956,512 It is described. The preparation of the polyamide imide has at least one polycarboxylic acid having at least two additional functional groups or an anhydride thereof and an imide ring having two carboxyl groups at adjacent positions according to known methods. It can be carried out from a polyamine having a primary amino group of or a compound having at least two isocyanates.

Polyamide imides can also be obtained by reacting polyamides, polyisocyanates consisting of at least two NCO groups and cyclic dicarboxylic anhydrides consisting of at least one additional group which may be condensed or added.

Furthermore, it is also possible to prepare polyamide imides from diisocyanates or from diamines and dicarboxylic acids if one of the components already consists of imide groups. Thus, especially tricarboxylic anhydrides are first reacted with diprimary diamine to give the corresponding diimidocarboxylic acids, which are reacted with diisocyanates to give polyamide imides.

Tricarboxylic acids or their anhydrides in which two carboxyl groups are in adjacent position are preferably used for the preparation of the polyamide imide. Preferred are two benzenes in molecules such as the corresponding aromatic tricarboxylic anhydrides such as trimellitic anhydride, naphthalenetricarboxylic anhydride, bis phenyltricarboxylic anhydride as well as those described in DE-A-1,956,512 And other tricarboxylic acids having a center and two adjacent carboxyl groups. Trimellitic anhydride is particularly preferred. Diprimary diamine already described under polyamidocarboxylic acid can be used as an amine component. In addition, aromatic diamines composed of thiadiazole rings such as 2,5-bis (4-aminophenyl) -1,3,4-thiadiazole, 2,5-bis (3-aminophenyl) -1,3, Mixtures of other isomers as well as 4-thiadiazole and 2- (4-aminophenyl (-5- (3-aminophenyl) -1,3,4-thiadiazole can also be used.

Suitable diisocyanates for preparing polyamide imides include aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate and trimethylhexamethylene diisocyanate; Alicyclic diisocyanates such as isophorone diisocyanate, ω, ω ',-diisocyanate-1,4-dimethylcyclohexane, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 1-methyl- 2,4-cyclohexane diisocyanate and 4,4'-dicyclohexylmethane diisocyanate; Aromatic diisocyanates such as phenylene diisocyanate, toluylene diisocyanate, naphthalene diisocyanate and xylene diisocyanate as well as substituted aromatic systems such as diphenyl ether diisocyanate, diphenyl sulfide diisocyanate, diphenyl sulfone diisocyanate and Diphenylmethane diisocyanate; Condensed aromatic-aliphatic and aromatic-hydroaromatic diisocyanates such as 4-pheny isocyanate methyl isocyanate, 1,5-tetrahydronaphthalene diisocyanate, 4,4'-hexahydrobenzidine diisocyanate and 4,4'-hexahydrodi Phenyl mecan diisocyanate is mentioned. Preference is given to using 4,4'-diphenylmethane diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate and hexamethylene diisocyanate.

Suitable polyamides are those obtained by polycondensation of dicarboxylic acids or derivatives thereof with diamines or by polycondensation of aminocarboxylic acids and derivatives thereof such as lactams.

Examples of suitable polyamides include dimethylene succinamide, pentamethylenepimelamide, undecane methylenetridecanedicarboxyamide, hexamethyleneadipamide, hexamethylene sebacamide and polycaproamide. Hexamethylene adipamide and polycaproamide are particularly preferred.

As in the case of polyamide carboxylic acids, a suitable solvent refers to an organic compound in which the functional group does not react mostly with the starting materials and dissolves at least one component, preferably the starting components and the polyamide imide. Examples include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methylcapro Lactam, dimethyl sulfoxide, N-methylpyrrolidone, tetramethylurea, pyridine, formamide, N-methylformamide, N-acetylpyrrolidone, dimethyl sulfone, tetramethylene sulfone and hexamethylphosphoramide. have.

Heavy metal salts soluble to cure the polyamide imide, such as zinc octoate, cadmium octoate, tetraisopropyl titanate, or tributyl titanate, are amounts of up to 3 wt. Can be used as

The viscosity of the 20-40% by weight solution of polyamide imide is 800-3,000 mPas at 23 ° C.

In addition to the binders and hardeners described above, in the case of polyurethane-based wire paints, the wire paints (Aa) to (Ad) are conventional amounts based on the total weight of the binder and the hardener or on the amount of binder, It may preferably consist of conventional auxiliaries, additives and rheology control agents in amounts of 0 to 10% by weight.

Typically, the solvent content of the wire paints (Aa) to (Ad) is 40 to 80% by weight, based on the overall formulation, but the solvent content depends on the paint viscosity to be adjusted in each case.

Likewise, the electrically conductive paint used in the second step of the process according to the invention is based on polyester imide (wire paint Aa), polyester (wire paint Ab), polyurethane (wire paint Ac) polyamide imide By the known wire paint described above. Electrically conductive carbon black and / or graphite is further added to the paint to achieve electrical conductivity. The amount of carbon black and / or graphite added depends on the binder of the wire paint. Furthermore, the amount depends in each case on whether carbon black or graphite is added as sole component or a combination of electroconductive carbon black and graphite is used. This is due to the fact that the addition of electrically conductive carbon black significantly reduces the tendency of graphite to settling. Thus, if a combination of electrically conductive carbon black and graphite is used, the proportion of carbon black can be lower than when carbon black is added alone because the main effect in this case is a reduction in the tendency of graphite to sedimentation. have. In addition, the magnification of the graphite can be significantly increased due to the reduced tendency for sedimentation. Moreover, the amount of carbon black and / or graphite to be used depends in each case on the desired conductivity of the resulting coating. The following amounts have proven satisfactory in the case of polyester imide and polyester based wire paints:

1) 2 to 20 parts by weight of conductive carbon black, preferably 8 to 12 parts by weight, per 100 parts by weight of polyester imide resin or polyester resin,

2) 50 to 110 parts by weight of graphite, preferably 80 to 105 parts by weight of polyester imide resin or 100 parts by weight of polyester resin, or

3) 1 to 12 parts by weight of conductive carbon black, preferably 2 to 6 parts by weight and 50 to 110 parts by weight of graphite, preferably 80 based on 100 parts by weight of polyester imide resin or polyester resin in each case. To 105 parts by weight of the combination.

On the other hand, the following amounts have proven satisfactory in the case of polyurethane-based wire paint (Ac):

1) 5 to 50 parts by weight of electrically conductive carbon black, preferably 20 to 40 parts by weight, per 100 parts by weight of polyurethane resin,

2) 2 to 40 parts by weight of graphite, preferably 8 to 18 parts by weight, per 100 parts by weight of polyurethane resin, or

3) 1 to 35 parts by weight, preferably 5 to 8 parts by weight, and 2 to 115 parts by weight of graphite, preferably 70 to 107 parts by weight, based on 100 parts by weight of the polyurethane resin in each case.

The following amounts have proven satisfactory in the case of polyamide-imide based wire paints:

1) 1 to 10 parts by weight of electrically conductive carbon black, preferably 2 to 8 parts by weight, per 100 parts by weight of polyamide imide

2) 60 to 110 parts by weight of graphite, preferably 70 to 95 parts by weight, per 100 parts by weight of polyamide imide resin, or

3) 1 to 10 parts by weight, preferably 2 to 8 parts by weight, and 60 to 110 parts by weight of graphite, preferably 70 to 95 parts by weight, based on 100 parts by weight of the polyurethane resin in each case.

In principle, certain conductive carbon blacks can be used that can be humidified by the wire paints (Aa) to (Ad). The average particle size of the carbon black used should be such that a smooth paint surface can be obtained. This means that the maximum average particle size of the carbon black used should be smaller than the dry film thickness of the electric paint film after single attachment.

Likewise, the graphite to be used should be able to be humidified by the wire paints (Aa) to (Ad). In addition, a smooth paint film must be obtained.

The most preferred embodiment of the method according to the invention is a process characterized in that the electrically conductive paint (= conductive paint) is a polyurethane wire paint consisting of a combination of carbon black and graphite in the amounts mentioned above. The method has the advantage of paint with a high content of carbon black / graphite which can be attached at high speed. Moreover, the resulting wire can be soldered directly.

If the polyurethane-based conductive paint is attached to a polyester or polyester imide insulating paint, it has another advantage that the conductive paint and the insulating paint can be separated off by selective melting.

In another preferred embodiment of the method according to the invention another insulating paint is attached to the electrically conductive coating, so that the conductive coating is insulated with respect to the outside. Suitable paints for this purpose are the polyester imide polyester, polyurethane and polyamide imide based wire paints described above.

Both insulating and electrically conductive paints are attached and cured using standard painting machines. In this method, the required paint film thickness is in each case constructed by at least one to ten individual coatings, with each individual paint coating being cured to obtain a bubble-free surface before the new coating is attached. Standard painting machines operate at feed rates of 5 to 180 m / min, depending on the thickness of the wire paint and the thickness of the wire to be coated. Representative oven temperatures are from 300 ° C. to 550 ° C. However, wire painting machines of this type are known and need not be discussed in greater detail herein. The possibility of attaching both insulated and electrically conductive paint to various wires, in particular thin wires (wire diameter <0.35 mm) by a standard painting machine, represents a significant advantage of the method according to the invention. In addition, the wires produced by the method according to the invention are very suitable for use as winding wires for the production of various electrical appliances, such as relays, coils, electric motors and the like. Since the wire according to the invention on the basis of its structure has a capacitive (series capacitor), it is particularly suitable for producing a capacitive energy-storage winding as described, for example, in DE-A-3,604,579. do. The winding can in most cases replace them when the capacitor and coil are operated together.

In addition to the wire with the metal layer as the outer conductive layer, the wire produced by the method according to the invention can be stretched in the coil former without tearing the conductive film due to the highly flexible conductive paint film.

Another important advantage of the method according to the invention is that the conductivity of the conductive paint film can be controlled within various ranges by electroconductive carbon black and / or graphite, which is impossible to achieve with metallic layers.

The invention is described in more detail by the following examples. Unless otherwise indicated, all parts and percentages are parts by weight and percentages.

[Production of Wire Paint 1 Based on Polyurethane (PUR)]

Wire paint 1 having a solids content of 27% (1 hour / 180 ° C.) was prepared from 3 moles of toluene diisocyanate and 1 mole trimethylolpropane according to conventional known methods (see eg DE-A-2,840,352). 6 parts by weight of glycerol, ethylene, glycol, and isophthalic acid having 28 parts by weight of the adduct (28 free isocyanate groups blocked with phenol) and an OH equivalent of 80, 33 parts by weight of cresol with 0.2 parts by weight of a commercially available amine-based catalyst. It is prepared by dissolving in a mixture of 33 parts by weight of and xylene.

[Production of Wire Paint 2 Based on Polyester Imide (PEI)]

The polyester imide is 3.9 parts ethylene glycol, 8.7 parts dimethyl terephthalate, 10.2 parts trihydroxyethyl isocyanurate (THEIC), 11.5 parts trimellitic anhydride and 5.9 parts 4.4'-diamino diphenyl methane to 0.04 parts tetra Prepared by reaction in the presence of -n-butyl titanate. The polyester imide is a cresol / solvent naphtha in a 2: 1 ratio. Dissolve in 56 parts of the mixture and treat with 0.7% commercial titanium catalyst based on the total kneading.

The wire paint obtained according to this method had a solids content of 39% (1 hour / 80 ° C.) at a viscosity of 800 mPas (23 ° C.).

[Production of Wire Paint 3 Based on Polyester (PE)]

A polyester with an OH value of 190 mg KOH / g is 0.1 part based on 5.5 parts ethylene glycol, 12.1 parts tris-2-hydroxyethyl isocyanurate, 20.5 parts dimethyl terephthalate and tetra-n-butyl titanate It is prepared from a conventional transesterification catalyst. Polyester is 41.5 parts cresol and 8.6 parts solvent naphtha with 2.0 parts phenolic resin and 1.7 parts catalyst Dissolve in The paint has a solids content of 40% (1 hour / 180 ° C.).

[Manufacture of Wire Paint 4 Based on Polyamide Imide (PAI)]

Polyamide imides are prepared from 38.5 parts trimellitic anhydride and 60.0 parts diphenylmethane diisocyanate according to the method described in DE-B-1,226,427. The 33% solution in N-methylpyrrolidone has a viscosity of 1500 mPas at 23 ° C.

Commercially conductive carbon black with 1000 parts of polyurethane-based wire paint 1, 270 parts of commercial graphite (average particle size 3-4 μm) and a particle size of 30 mm and a surface (N ₂ adsorption) of 254 m ₂ / g 19.05 The part is dispersed for 30 minutes at 1835 rpm. Conductive paint 1 obtained according to the method has a solids content of 43.4% (1 hour / 180 ° C.) and is slightly thixotropic.

Copper wire (diameter 0.14 mm) is painted on a tandem paint machine at a rate of 80 m / min. The wire paint 1 is first attached by feeding eight times and baked at 400 ° C. Conductive paint 1 is then attached by three feeds and baked at 250 ° C to 350 ° C. The capacitance and resistance of the conductive paint film is measured on a 1 m long wire coated according to the method. The results of the study are listed in Table 1.

Example 2

The copper wire (diameter 0.71 mm) was coated with wire paint 2 in a standard painting machine by feeding eight times at a feed rate of 28 m / min, and then baked at 500 ° C. to 520 ° C. The conductive paint 1 (also used in Example 1) is attached to the wire paint by feeding six times at a feed rate of 24 m / min and baking at 460 ° C. to 480 ° C. The resistance and capacitance of the conductive paint film are measured on 1 m long wire coated according to the above method.

Furthermore, the conductive paint adheres at a different rate than the above, and investigates the effect on the resistance of the resulting conductive paint film and the effect on the capacitance. The results of the study are listed in Table 1.

Example 3

Except that the oven temperature at the time of curing the insulating coating as well as the oven temperature at the time of curing the conductive coating is from 420 ° C. to 460 ° C., the same method as in Example 2 is used to produce a wire coated with insulating paint and conductive paint. A coating wire having the resistance and capacitance values specified in Table 1 is obtained at a painting rate of 26 m / min.

Example 4

920 parts of the polyurethane-based paint wire 1 and 80 parts of carbon black used in Example 1 were dispersed at 2330 rpm for 30 minutes. Conductive paint 2 obtained according to the method had a solids content of 32.8% (1 hour / 180 ° C.). The copper wire (? 0.71 mm) was recovered to wire paint 2 on a standard painting machine by feeding eight times at a feed rate of 28 m / min, and baked at 500 ° C. to 520 ° C.

The wire paint film is then coated with a conductive paint as described above and baked (dry film thickness 42 mu m). Capacitance and resistance of the conductive coating are measured on 1 m long wire coated according to the above method. The results are listed in Table 1.

Example 5

500 parts by weight of polyester imide-based wire paint 2, 10.4 parts of carbon black used in Example 1 and 195 parts of graphite used in Example 1 were dispersed at 1835 rpm for 30 minutes. Conductive paint 3 obtained according to the method had a solids content of 56.8% (1 hour / 180 ° C.). Copper wire (ψ1 mm) was coated with wire paint 2 (dry film thickness of 50 mu m). The wire paint is then coated with the conductive paint described above and cured (dry film thickness 45 [mu] m).

Capacitance and resistance of the conductive coating are measured on the wire coated according to the above method. The results are listed in Table 1.

Example 6

1,000 parts of polyester imide-based wire paint 2 and 40 parts of carbon black used in Example 1 were dispersed for 10 minutes at 1835 rpm. 30 parts of cresol and 30 parts of solvent naphtha Use to dilute to 900 mPas (23 ° C). Conductive paint 4 obtained according to the method had a solids content of 39.1% (1 hour / 180 ° C.).

Copper wire (diameter 1 mm) was coated with wire paint 2 on a standard painting machine (oven length 3 m, 7 paint coat, oven temperature 520/540 ° C.) by feeding six times at a feed rate of 28 m / min. The wire paint coating was then coated on the same paint machine using conductive paint 4 described above by feeding six times at a feed rate of 8.5 m / min. Capacitance and electrical resistance of the conductive paint film were measured on a 1 m long wire coated according to the above method.

Example 7

600 parts of polyester-based wire paint 3, 192 parts of graphite used in Example 1 and 9.5 parts of electrically conductive carbon black used in Example 1 were dispersed at 1835 rpm for 30 minutes. Conductive paint 5 prepared according to the method had a solids content of 55% (1 hour / 180 ° C.). The conductive paint 5 is attached to a copper wire (1 mm in diameter) coated with wire paint 2 (dry film thickness of 50 mu m) at a film thickness of 35 mu m. The conductive paint film has an electrical resistance of 960 kPa / m (see Table 1).

Example 8

600 parts of polyamide imide-based wire paint 4, 180 parts of graphite used in Example 1 and 7.8 parts of electroconductive carbon black used in Example 1 were dispersed at 1835 rpm for 30 minutes. The solids content of the conductive paint 6 prepared according to the method was 46.7% (1 hour / 180 ° C.).

Conductive paint 6 adheres to a copper wire (diameter 1 mm) insulated with wire paint 2 (dry film thickness of 50 μm) with a film thickness of 45 μm. The conductive paint film has an electrical resistance of 970 kPa / m (see Table 1).

TABLE 1

a: binder of insulated wire paint (WP)

b: binder of conductive paint (CP)

Claims (13)

Iii) the wire is first covered with insulating paint to produce a continuous, nonporous insulating coating on the wire surface, and Ii) A method for continuous coating of wires, wherein the electrically conductive coating is attached to the insulating coating by coating the insulating wire produced by the method of step (i) with an electrically conductive paint. A) Insulation paint attached directly to the wire surface a) a polyimide of which the hydroxyl value of the polyester imide is 50 to 200 mg KOH / g, and the solution of 20 to 60% by weight of the polyester imide in the organic solvent has a viscosity of 80 to 15,000 mPas at 23 ° C. Polyester imide and ear paint consisting of a solvent solution, an aqueous solution or an aqueous acid solution of an ester imide resin, b) a polyester resin wherein the polyester has a hydroxyl to carboxyl group ratio of 1.1: 1 to 2.0: 1, and the 20 to 60 wt% solution of the polyester in the organic solvent has a viscosity of 40 to 12,000 mPas at 23 ° C. Polyester wire paint, consisting of a solvent solution or an aqueous solution of c) a solvent having a solvent solution of a diisocyanate (free isocyanate completely blocked) and an adduct of a polyol prepared at an NCO / OH equivalent ratio of 1: 2 to 9: 1 and a OH value of 100 to 450 mg KOH / g. Polyurethane wire paint, consisting of a solvent solution of a siloxane-containing polyester, or d) 20 to 40% by weight solution of polyamide imide is selected from the group of polyamide imide wire paints consisting of a solvent solution of polyamide imide having a viscosity of 800 to 3,000 mPas at 23 ° C., B) The conductive paint attached to the insulated wire e) conductive wire paint 1) 2 to 20 parts by weight of conductive carbon black per 100 parts by weight of polyester imide resin or polyester resin, 2) 50 to 110 parts by weight of graphite per 100 parts by weight of polyester imide resin or polyester resin, or 3) In each case, a polyester imide wire paint produced by adding a combination of 50 to 110 parts by weight of graphite and 1 to 12 parts by weight of conductive carbon black based on 100 parts by weight of polyester imide resin or polyester resin ( Aa) or polyester wire paint (Ab), f) conductive wire paint 1) 5 to 50 parts by weight of conductive carbon black per 100 parts by weight of polyurethane resin, 2) 2 to 40 parts by weight of graphite per 100 parts by weight of polyurethane resin, or 3) polyurethane wire paint (Ac) produced by adding a combination of 2 to 115 parts by weight of graphite and 1 to 35 parts by weight of conductive carbon black, in each case based on 100 parts by weight of polyurethane resin, or g) conductive wire paint 1) 1 to 10 parts by weight of conductive carbon black per 100 parts by weight of polyamide imide resin, 2) 60 to 110 parts by weight of graphite per 100 parts by weight of polyamide imide resin, or 3) Group of polyamide imide wire paints (Ad) produced by adding a combination of 60 to 110 parts by weight of graphite and 1 to 10 parts by weight of conductive carbon black based on 100 parts by weight of polyamide imide resin in each case. A method for continuous sheathing of wires. A) Insulation paint attached directly to the wire surface a) a polyimide of which the hydroxyl value of the polyester imide is 50-200 mg KOH / g, and the solution of 20-60 wt% of the polyester imide in the organic solvent has a viscosity of 80-15,000 mPas at 23 ° C. Polyester imide and ear paint consisting of a solvent solution, an aqueous solution or an aqueous acid solution of an ester imide resin, b) a polyester resin wherein the polyester has a hydroxyl to carboxyl group ratio of 1.1: 1 to 2.0: 1, and the 20 to 60 wt% solution of the polyester in the organic solvent has a viscosity of 40 to 12,000 mPas at 23 ° C. Polyester wire paint, consisting of a solvent solution or an aqueous solution of c) a solvent having a solvent solution of a diisocyanate (free isocyanate completely blocked) and an adduct of a polyol prepared at an NCO / OH equivalent ratio of 1: 2 to 9: 1 and a OH value of 100 to 450 mg KOH / g. Polyurethane wire paint, consisting of a solvent solution of a siloxane-containing polyester, or d) a 20 to 40% by weight solution of polyamide imide is selected from the group of polyamide imide wire paints consisting of a solvent solution of polyamide imide having a viscosity of 800 to 3,000 mPas at 23 ° C., B) The conductive paint attached to the insulated wire e) conductive wire paint 1) 2 to 20 parts by weight of conductive carbon black per 100 parts by weight of polyester imide resin or polyester resin, 2) 50 to 110 parts by weight of graphite per 100 parts by weight of polyester imide resin or polyester resin, or 3) In each case, a polyester imide wire paint produced by adding a combination of 50 to 110 parts by weight of graphite and 1 to 12 parts by weight of conductive carbon black based on 100 parts by weight of polyester imide resin or polyester resin ( Aa) or polyester wire paint (Ab), or f) conductive wire paint 1) 5 to 50 parts by weight of conductive carbon black per 100 parts by weight of polyurethane resin, 2) 2 to 40 parts by weight of graphite per 100 parts by weight of polyurethane resin, or 3) polyurethane wire paint (Ac) produced by adding a combination of 2 to 115 parts by weight of graphite and 1 to 35 parts by weight of conductive carbon black, in each case based on 100 parts by weight of polyurethane resin, or g) conductive wire paint 1) 1 to 10 parts by weight of conductive carbon black per 100 parts by weight of polyamide imide resin, 2) 60 to 110 parts by weight of graphite per 100 parts by weight of polyamide imide resin, or 3) Group of polyamide imide wire paints (Ad) produced by adding a combination of 60 to 110 parts by weight of graphite and 1 to 10 parts by weight of conductive carbon black based on 100 parts by weight of polyamide imide resin in each case. And a conductive wire coated with a metal conductor core, an insulating paint film attached to the conductor core, and an electrically conductive film attached to the insulating paint film. The method of claim 1 wherein the conductive paint is e) conductive wire paint 1) 8 to 12 parts by weight of conductive carbon black per 100 parts by weight of polyester imide resin or polyester resin, 2) 80 to 105 parts by weight of graphite per 100 parts by weight of polyester imide resin or polyester resin, or 3) polyester imide wire paint produced by adding a combination of 80 to 105 parts by weight of graphite and 2 to 6 parts by weight of conductive carbon black based on 100 parts by weight of polyester imide resin or polyester resin in each case ( Aa) or polyester wire paint (Ab), f) conductive wire paint 1) 20 to 40 parts by weight of conductive carbon black per 100 parts by weight of polyurethane resin, 2) 8 to 18 parts by weight of graphite per 100 parts by weight of polyurethane resin, or 3) polyurethane wire paint (Ac) produced by adding a combination of 70 to 107 parts by weight of graphite and 5 to 8 parts by weight of conductive carbon black, in each case based on 100 parts by weight of polyurethane resin, or g) conductive wire paint 1) 2 to 8 parts by weight of conductive carbon black per 100 parts by weight of polyamide imide resin, 2) 70 to 95 parts by weight of graphite per 100 parts by weight of polyamide imide resin, or 3) Group of polyamide imide wire paints (Ad) produced by adding a combination of 70 to 95 parts by weight of graphite and 2 to 8 parts by weight of conductive carbon black based on 100 parts by weight of polyamide imide resin in each case. And selected from. 4. The method of claim 1 or 3, wherein the conductive carbon black used has a smaller average particle size than the dry film thickness of the conductive coating after single deposition. The diisocyanate (freeisocyanate group is completely blocked) and trimethylolpropane according to claim 1 or 3, wherein the insulating paint or the electrically conductive paint directly attached to the wire surface is prepared in an NCO / OH ratio of 1: 2 to 9: 1. A polyurethane topcoat paint (Ac) consisting of a solvent solution of an addition product of and a solvent solution of a hydroxyl-containing polyester having an OH value of 150 to 500 mg of KOH / g. The polyurethane topcoat paint (Ac) consists of an adduct of diisocyanate (its free isocyanate groups are completely blocked) and trimethylol propane, wherein the polyurethane topcoat paint (Ac) is prepared in an NCO / OH ratio of 2: 1. How to. 7. Process according to claim 1 or 6, characterized in that the polyurethane wire paints used have their free isocyanate groups blocked with phenol or cresol. The method according to claim 1 or 6, wherein the used polyurethane wire paint (Ac) uses toluylene diisocyanate or bis (4-isocyanatophenyl) -methane as the diisocyanate component. A process according to claim 1, characterized in that trishydroxyethyl isocyanate is used as polyester wire paint (Ab) for insulating paints or electrically conductive paints. The method according to claim 1, characterized in that a polyester solution having a hydroxyl to carboxyl group ratio of 1.15: 1 to 1.60: 1 is used as the polyester wire paint (Ab) for insulating paint or electroconductive paint. The process according to claim 1, characterized in that trishydroxyethyl isocyanate is used as the polyester imide in the polyester imide wire paint (Aa) for insulating paints or electrically conductive paints. The method of claim 1, wherein the polyester imide wire paint (Aa), polyester wire paint (Ab), polyurethane wire paint (Ac) or polyamide imide wire paint (Ad) is further attached to the conductive coating. A method in which the conductive coating is insulated from the outside. A method according to claim 2, wherein the wire according to claim 2 is used to generate a capacitive energy-storage induction winding.