DE1615830A1 - Insulated electrical conductors and processes for their manufacture - Google Patents

Description

Dr. Beck & Co. AG., Hamburg 28, Eiselensweg

Insulated electrical conductors and processes for their manufacture

The invention relates to insulated electrical conductors with a novel resin combination, the excellent thermal Has stability and good abrasion resistance. Usually electrical conductors insulated with lacquer films are produced by passing the metallic conductor through a lacquer bath with a resin solution passes through it, possibly several times, and after each Painting under the influence of heat, the solvent evaporates and the resin on the conductor burns and hardens.

Eemis cross-linked terephthalic acid polyesters have been used for a long time to achieve highly heat-resistant wires.The disadvantages of this resin insulation include insufficient thermal shock resistance and unsatisfactory mechanical properties, and above all the abrasion resistance of such wire gap insulation is not high enough to process the wire on modern, fully automatic winding machines to be able to. According to the proposal of US Pat. No. 3,022,200, these disadvantages can be partially improved by coating the wire provided with the basic insulating layer with an additional coating made of a thermoplastic polymer with a melting point above 175 ° C., for example a high molecular weight linear terephthalic acid glycol polyester will. In this case, however, the dielectric properties are impaired, especially in the heat, due to the linear polyester.

On the other hand, a completely new class of substances has recently emerged found for the electrical insulation of conductors. It is certainly about the polyhydantoins. The manufacture of such Polyhydantoine is e.g. in DAS 1 230 568 and the German Patent application B 90 633 IVd / 39-c described.

The manufacture of electrical conductors, e.g. wires made with polyhydantoins are coated is also in German Application B 90 633 IVd / 39c.

1) 098 26/1713

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The polyhydantoin lacquer films show a good short-term thermal overload capacity and good mechanical properties.

It has now been found that the elasticity and especially the abrasion resistance and the thermal properties of with crosslinked terephthalic acid polyesters lacquer-insulated electrical conductors can be greatly improved, if an additional insulation layer made of polyhydantoin is applied to the polyester insulation. According to the invention The coatings obtained have above all an improved heat shock resistance. In addition, these coatings show compared to the known coatings according to the aforementioned US patent increased resistance to saponifying agents, especially acidic media.

From the attached FIG. 1, the structure of the inventive Conductor isolation. A base layer insulation is first applied to an electrical conductor, e.g. a wire (2) Applied from a crosslinked terephthalic acid polyester and cured there in the usual way. These The first insulation layer is covered by a second, preferably thinner, coating (3) made of polyhydantoin.

The invention further encompasses the manufacture of such insulated electrical conductors. In this case, the base coat (2) is applied in a manner known per se, if necessary in several layers. applied from the terephthalic acid polyester resin and cured. Then the other becomes thinner in the same way Coating (3) made of polyhydantoin lacquered on by the conductor provided with the base coating (2) through once or several times a heated polyhydantoin lacquer bath is drawn and the resin layer is baked onto it.

The processing conditions, in particular the stoving ' The temperature and the take-off speed can be used for the production of these layers in the two paint systems be chosen the same, so that preferably in only one Operation can be driven. Here it must be ensured that the wire successively the two respective Paint baths happened separately. Of course, the wire can pass through the respective paint bath several times.

009826/1713

Only for the sake of completeness is here shortly afterwards pointed out that the known polyhydantoins which are used in the context of the invention, according to the teaching of the above older patent by reacting with acetic acid or acetic acid derivatives substituted aromatic di- or triamines of the following structural formula

AR -

NH - C - CQR,

R-,

η = 2 - 3

R ₂ = OH, O-alkyl, O-aryl, amino or subst. Amino groups

R ₁ - ■ - = H, alkyli-est

wi.t miird, 2 NGO groups in the molecule containing Iocyaiiatverbindungen can be obtained at temperatures between 10 and 230 ⁰ C »> / - ^:. ".

In the following examples .h

Example 1 the preparation of one for the base layer ■ Usable terephthalic acid polyester varnish

the production of one that can be used for the top layer Polyhydantoin spots

the manufacture of an electrical conductor with a base layer according to Example 1 and a top layer yes. Example 2.

Example 2 Example 3

Example rl-i .- ■ V '■ - Ί'"'" ¹ ^: ■ - ^: -v- -..- .. J- ""' ■ -

a) 193 * 2 GediehtstiBdle / glycerol, \ L93 _S 2 parts by weight of glycol, 1Ό5 Gewiöhtsteile "Kres oil EAB 6 so \ Nfie 8-1.5 pbw Tetreplktliälsifuredinieithylester and 31 57 weight parts st Cernaphithenat in 6fSiger Lösting ih" _f aromatics such as toluene, Xylene or SolyentnaphithaV are filled into a three-necked flask in the order given. an agitator ,, eiirem Titennönteter üiKd is provided with a Destiilierausfsat2 -. * .- The mixture is heated sehaell aaf 1 ^ Of ¹ C and then increases by 5 € ^S ^ jföi hour until 2P5 ^E C errexeh-t are is! the Beafetxon: under a system of egg;! Carbonic acid lain? this: M & s & tiöaspx '& ^ & ss & s eTit-mtt man a = from about 30 · © ^ Gev., share "FJIüsssigfeeit # soft ahead ifethancil- feesrtenit ^ Daamf" sindi attf l &Q> ^a [£

b) Now you are 43 -, 6 g parts by weight of terephthalic acid added, _ heated to 2l5 ° G and holds for 1 hour at this temperature. It is again cooled to 18O ⁰ C and added to 43 »6 parts by weight of terephthalic acid again heated to 215 ⁰ C and maintained at this temperature for 3/4 hours. ¹ During the esterification process, around 25 parts by weight of distillate are obtained, which mainly consists of water.

c) It is then cooled again from, added 10.5 parts by weight Zinknaphthenatlösung with a content of 8 $ zinc at 200 ⁰ C are added and further cooled to l4o ° C. At 30 mm pressure, the distillate is then distilled over the course of 3 hours with heating from 140 to 175 ° C., about 80 to 90 parts by weight of distillate being obtained * which consists primarily of cresol.

d) After the vacuum distillation has ended, the temperature is ^{increased to 225 °} C. over the course of about 3 hours while introducing carbonic acid. Maintaining the reaction mixture so long as at this temperature until a sample - diluted with cresol to a solids content of 4Ö $ - a DIN viscosity of 20 min at 20 ⁰ C and 4 mm Dübe has reached..

Then rapidly added with stirring 420 parts by weight of cresol added i cools the solution to l4o ° C and treated them with a mixture of 15 "75 parts by weight of butyl titanate, 70 parts by weight of cresol DAB 6 and 19 parts by weight Splventnaphtha and with a resolution of 2.6 parts by weight p-TölüoisüifoBäüre in 35 parts by weight of Diöxyaeetönalkohol and 17 parts by weight of Solventhäphtha. The mixture is then left to react for 10 minutes at 140.degree. C. and a further 420 parts by weight of Kresöi are added

The 48% solution obtained in this way is treated with cresol, SolVentnäphthä or xylene diluted to $ 35,

B. ύ ! game .JtL ,,

a) I98 Gewlfehtsteile 4 »4'-Diäminödiphfenylmethan, 200 GeWichtsteiie Cäieiüincärbonat and 1500 Gewichtsteiie water are heated to 80 ⁰ C and trains dropwise initially 244 parts by weight Ghioressigsäiireäthylester at this temperature. It is held for 2 hours at 8Ö ^Ö G and then another 217 weights of steep chiorenic acid ethyiest are added. After the development of carbon dioxide has ended, the organic phase is separated

001120/17 13

i. 5 i.

j J 615830

of the aqueous calcium chloride solution, washes several times with hot water and absorbs ethanol with approximately equal parts by weight. Small amounts of 4,4 ^J -bis (N-carbäthoxymethylamino) -diphenylmethane precipitate. After concentrating the ethanolic solution, the desired 4,4'-bisCN-carbäthoxymethyl-N-cabäthoxyamin-) diph.enylmeth.an remains as a viscous residue, the IR spectrum of which clearly agrees with the assumed structure.

b) 51 »4 parts by weight of the glycine derivative obtained according to a) and 19.9 parts by weight 4,4V-diaminodiphenylmethane are initially heated to 200 ° C. in a stirred flask under nitrogen. Even small amounts of ethanol distill off during this process. The temperature now wnird slowly over 10 hours at 25O ⁰ C increased and maintained at this temperature, the mass until barely can move. A 12% solution is produced by adding cresol / solvent naphtha in a ratio of 1:

example 3:

The lacquers described in Examples 1 and H were successively lacquered and baked on copper wire of 1 mm × 6 using the customary method using a wire enamelling oven 2.50 m long and at an oven temperature of 480 ° C.

Here, the polyester coating provided in accordance with Example 1 alone, and P _o lyhydantoin overcoated following values.:

Varnish after
example 1 Paint according to Bei
game 1 covered
with paint from Bei
game 2 Paint application -. '70 μ 71μ (55/16) Surface hardness 2-3 H. O XT
_Y XX Abrasion
Load of 56O cP 68 double strokes 110 double strokes Curl shock lh / 200 ° C 7 χ JZS ok 2 χ φ OK Softening temperature
(according to DIN 46453) 310 ⁰ C 34O ' ⁹ c
■ 'v .. - ·
.. '.' ■■ "'■ -'■" ■

"00 98 26/171 3

Claims (6)

Claims 1. Electrical conductor with a base layer insulation made of a cross-linked terephthalic acid polyester, marked, by an overlying top layer insulation made of a polyhydantoin. 2. Electrical conductor according to claim 1, characterized in that that the top layer insulation consists of a polyhdantoin that has aromatic rings between the hydantoin rings. 3 · Electrical conductor according to claim 2, characterized in, that the top layer insulation has a thinner layer than the base layer insulation. 4. A method for producing electrical conductors according to one or more of the preceding claims, characterized in that characterized in that an additional thin coating is made on an electrical conductor coated with the polyester a polyhydantoin is applied in a known manner and burned in there. 5 · The method according to claim 4, characterized in that a additional coating of a polyhydantoin, which has aromatic rings between the hydantoin rings, applied and is branded. 6. The method according to claims 4 and 5 »characterized in that that the processing conditions for applying the base layer solatxon and the top layer insulation are chosen to be the same are, in particular, working in just one operation in such a way that the wire is consecutively two separate Goes through lacquer baths. 009826/1713