DE2061124A1 - Layer material, process for its production and aqueous solution for carrying out the process - Google Patents

Description

"Layered material, process for its manufacture
and aqueous solution for carrying out the process "

The present invention relates to a layer material with at least one layer made of an electrical alloy
high permeability and low core loss (alloy layer) and at least one essentially water-insoluble, hardened, electrically insulating layer (insulating layer) adhering to it, a method for producing such a layer material and an aqueous solution for carrying out this process.

The development of electrical alloys with high permeability and low core loss has enabled the development of more efficient and powerful electrical devices.

109828/1883

206-124

A large percentage of these alloys contain iron. Grain-oriented ones belong to this group of electrical alloys and non-oriented silicon-iron alloys, nickel-iron alloys, Cobalt-iron alloys, vanadium periaendur and Supermendur. However, silicon-iron alloys are the probably most important electrical alloys, so accordingly in the description below specifically on these alloys, referred to for short as silicon steels will be referred to.

Transformer cores "and other electrical devices are made of layer material or layer packages to restrict the flow of eddy currents or migrating currents and thereby reducing core losses. To prevent eddy currents between the individual lamellae of such a Layers flow, but each lamella must be isolated from the rest. The normal surface oxide layers on fully annealed silicon steel sheets result in a certain insulation, but this in many cases is insufficient and needs to be supplemented or reinforced. Additional insulating properties can be achieved by coating the silicon steel can be achieved with a material that has a high electrical resistance and normal operating conditions or stresses, e.g. temperature and pressure, resists. ·

In U.S. Patent 2,755,282, there are insulating layer solutions described, which consist of primary magnesium phosphate, monobasic ammonium phosphate, chromic anhydride and Water are produced. These solutions contain 5 to 75 parts by weight of primary per 100 parts by weight of water

109828/1883

Magnesium phosphate, ΊΟ -135 parts by weight monobasic Ammonium phosphate and 1-6 parts by weight of chromic anhydride.

It has now been found that the insulation properties are th by using solutions similar to those described in the United States patent 2,753,282 described, are considerably similar can be improved if the solutions with ions of at least one metal from group II A of the periodic System of elements, e.g. magnesium and / or calcium, are essentially saturated. Furthermore, it has been found that at least one Mo 1% of which differs from a metal Group II A derivative. Metal ions (metal cations) as Oxide, hydroxide, carbonate, bicarbonate and / or chromate are made available or incorporated into the solution target. Solutions that contain all of their metal cations received from phosphates of the metal or metals in question ^ contain too many phosphate ions, which make them hygroscopic and solutions to which their content on metal cations in the form of compounds other than phosphates, oxides, hydroxides, carbonates, bicarbonates and / or chromates contain undesirable ions.

The invention is therefore based on the object of an improved Layer material of the type mentioned at the beginning to provide a method for producing such layer material available, and a solution to carry out this process or to produce insulating layers with improved properties to deliver-

109828/1603

2Ü6112A

The subject of the egg-finding is a layer material from the introduction designated type, which is characterized in that the insulating layer (cn) made of a.uo chromium, oxygen and anionic polymer chains consisting of phosphorus atoms and cations of at least one metal of group II Ä of the periodic table (metal cations) consists or consist and is or are at least saturated with metal cations in the chemical sense.

According to the invention, these insulating layers are produced with the aid of aqueous solutions which, apart from water, essentially consist of ammonium, chromate, phosphate and metal cations and are essentially saturated with regard to their content of ions of at least one metal from group II A of the periodic table. Calcium and magnesium ions are preferred as metal cations because compounds containing calcium and magnesium are readily available. The ions are present in the aqueous solutions according to the invention in a ratio of 6-18 mol% ammonium ions, 21-63 mol% phosphate ions, 8-24 mol% chromate ions and 15-4-5 mol% metal cations. The aqueous solutions of the invention preferably contain, based on the total content of the aforementioned types of ions, 9-15 mol% ammonium ions, 30-55 mol% phosphate ions, 11-20 mol% chromate ions and 25-35 mol% metal cations. For the purposes of the present invention, the term "phosphate ions" includes all ions or the compounds or forms in which phosphoric acid can occur in aqueous solution. This means that H ₃ PO ₄ , H ₂ PU ₄ , HPO ~~ and P0 ~~~ and all polyphosphoric acid anions are collectively referred to as phosphate ions. Correspondingly, CrO can also be in solution

109828/1883 BATH

as CrO. , CrpO ,. Etc.,. as well as in the form of various proponised lon ^ n exist, all of which, from the indication "Chromate ions" include v / should be grounded.

The ions, i.e. ammonium, phosphate, chromate and metal cations can be incorporated into the solutions in various ways. Ammonium ions can be found in the solutions in Incorporated in the form of ammonia, as aqueous ammonium hydroxide or as phosphate, chromate, carbonate or bicarbonate. Phosphate ions are most expediently added to the aqueous solutions in the form of ortophosphoric acid. You can do it but also incorporate aqueous solutions in the form of magnesium phosphate, ammonium phosphate or magnesium ammonium phosphate. The chromate ions can be added to the solutions as chromium trioxide or in the form of magnesium or ammonium chromate or bichromate incorporate. The metal cations, i.e., ions of Group II A metals as defined above, can the solutions in the form of oxides, hydroxides, carbonates, bicarbonates, phosphates or chromates of the metals concerned or incorporated as elemental metals. According to the invention, however, at least 1 mol% of the metal cations should be used in Form of the corresponding oxide, hydroxide, carbonate, bichromate and / or chromate added or available be asked. Solutions that have their total content of metal cations in the form of the corresponding metal phosphates is added contain too much phosphate ions, which make them or the insulating layers made from them hygroscopic can make, while solutions in which the metal cations are in the form of compounds other than the corresponding phosphates, Oxides, hydroxides, carbonates, bicarbonates and / or chromates

10 9828/18 83
BATHROOM

unwanted or disruptive other ions contain.

A wetting agent can be added to the aqueous solutions according to the invention in order to achieve the best possible wetting of the emergency surfaces to be treated with it. However, the use of wetting agents is a contingency measure and by no means absolutely necessary. A typical wetting agent useful for the purposes of the invention is "Wetanol" (available from Glyco Products, Inc. New York, New York).

The method of the invention comprises the following steps:

Coating or treating an alloy with higher permeability and low core loss, e.g. of a silicon steel, with the described aqueous solution according to the invention and hardening of the layer applied or generated in this way, to make them essentially water-insoluble. Zuxa Be " any known application method can be used. The invention does not depend on the application a certain application or coating method. Examples of suitable known application methods are dipping, Flow coating, spraying, roller coating and spin coating.

The hardening or baking is a time and temperature dependent process. The time required is shorter at higher temperatures and vice versa. At cure between 2 seconds and 4 hours were successfully curing temperatures, ie, temperatures applied to the respective metal surfaces in a range from 204.4 to 1037.8 ⁰ C.

1 0 9 8 2 8 Ll

COPY
BATH ORIGINAL

_ Π -

As already mentioned, there is layer material according to the invention of at least one layer made of an alloy with high permeability and low core loss, e.g. B. Silicon steel, and at least one essentially or practically water-insoluble, electrically insulating slide (Insulating layer). According to a preferred embodiment According to the invention, the layer material consists of several alloy layers, each separated by insulating layers from the adjacent alloy layers and against these are electrically isolated. The insulating layers consist of anionic polymer chains made of chromium, oxygen and phosphorus atoms and metal cations, e.g. magnesium cations, which are present in saturation concentration.

The insulating layers should be at least 0.001 mm and preferably at least 0.0015 mm thick in order to achieve a sufficient ensure electrical resistance. Layer material that is stress-relieved should have at most one Have an insulating layer 0.0076 and preferably less than 0.0051 mm thick to ensure that the insulating layer Adheres sufficiently well after the stress relief annealing.

The examples illustrate several embodiments of the invention. '. - "

example Λ

By mixing 22.5 S ^r primary ammonium phosphate, 103.0 g primary magnesium phosphate, 25 g chromic acid and 400 mil water, a solution, hereinafter referred to as solution A

109828 / 1-8Ö3-COPY

rad ORIGINAL

206112A

designated, aqueous solution prepared. This solution is applied to a silicon steel strip by dipping, whereupon the solution is dosed by means of grooved rubber rollers or the thickness of the solution film is adjusted with the help of such rubber rollers. The layer applied or produced in this way is then cured for 35 seconds at 648.9 ° C. A hardened layer 0.0022 mm thick is obtained. After hardening, the coated silicon steel is stress relieved in a Cr ackgasatmoSphere for one hour at 898.9 ° C.

For comparison, an aqueous solution referred to below as "solution B" is prepared by mixing 22.5 gr primary ammonium phosphate, 103.0 gr primary magnesium phosphate, 25} 0 gr chromic acid and 400 ml v / water produced, to which 5 gi "of magnesium oxide are also added. This solution is analogous to that used for solution A. Working method a silicon steel strip is coated, a 0.0026 mm thick hardened layer being obtained. After hardening, the silicon steel thus coated becomes exactly like the silicon steel coated with the solution A stress relief annealed.

The electrical resistance of both silicon steel strips' is determined before and after the stress relief annealing, the so-called Franklin value (ASTM Designation A-344-68) is determined. A perfect one Isolator would have a Franklin value of 0 (Franklin value is given in amperes) while a perfect one Conductor would have a Franklin rating of 1 amp. The Franklin values of the silicon coated with solutions A and B

109828/1 & 83

Steel belts can be seen in Table I below.

■ Table I

Solution Franklin value Franklin value

(like coated,? relaxation treated; anneals

A 0.33 0.97

B ■■ *, 0.07 0.48

From Table I it can be seen that with the help of solution B. a far better insulating insulating layer or a far higher electrical resistance is achieved than with solution A (smaller Franklin values mean higher electrical resistance). This result confirms the technical progress achieved according to the invention, since the solution B according to the invention is saturated with magnesium ions, the solution A, not according to the invention, however, does not.

The following table II gives the mole percentages, in which the ammonium, phosphate, chromate and Magnesium ions in der'Lösung A and B, respectively, based on the total content of these ions.

i Table II

Solution Ammonium ions Phosphate ions Chromate ions Magnesium ions (MpI -%) (Mol-%) (Mol-%) (Mol-%)

A 91 7 55.3 12.1 22.8

B 9.2 52.3 ■ 11.5 27.1

109828 / 18Ö3

206112A - ίο -

It should be noted that the magnesium ion content of solution B is 27.1 Μο1 ~%, whereas that is of solution A is only 22.8 mol%, i.e. that solution B thus has a magnesium ion content that is 4.5 Mo 1% higher as the solution A. This additional magnesium ion content is given to the solution, as mentioned above, in the form of magnesium oxide added, which at the same time increases the phosphate ion content of 55> 3 mol% for solution A reduced to 52.3 mol% for solution B. One would adding the additional amount of magnesium ions in the form of additional magnesium phosphate would result from this an increase in the phosphate ion content of 55 »3 mol% to about 59 »8 mole percent. In other words, one obtains that you get the additional amount of magnesium ions in the form of magnesium oxide and not in the form of magnesium phosphate adds an aqueous solution with a phosphate ion content of 52.3 mol% instead of a solution with one Phosphate ion content of 59 »8 mol%.

Example 2

Further silicon steel samples are coated with solution B and then hardened at 64 ° C. for 35 seconds. A hardened insulating layer 0.0025 mm thick is obtained. After hardening or ». Burning in the insulating layer the coated silicon steel samples are placed in different gas atmospheres for one hour each 843j3 C stress relief annealed.

The electrical resistance of the test panels is measured before and after the stress relief annealing. The one with it

109828/1683

noted Franklin values are from the following Table III can be seen.

Table III Franklin value the atmosphere Franklin value RELAXATION COOLED (like "coated) 0.18 Cracked gas 0.13 0.43 nitrogen 0.09 0.54 hydrogen 0.04 0.40 Synthesis gas 0.05 0.02 Calm air " 0.09

From Table II it can be seen that according to the procedure The insulating layers produced by the invention are good insulators both before and after the stress relief anneal and especially * the reducing effect · of water st Withstand glowing atmospheres extremely well.

For the person skilled in the art, the general information explained above with reference to specific exemplary embodiments emerges Invention ideas a number of different further modifications and possible uses of the .Erfindung of itself, so that the invention is of course not limited to the specific exemplary embodiments or their details should be limited.

"10982.8 / 1003

Claims (1)

Claims Layer material with at least one layer made of an electric alloy with high and low permeability Core loss (alloy layer) and at least one essentially water-insoluble adhering to it, . hardened, electrically insulating layer (insulating layer), characterized in that the insulating layer (s) of anionic polymer chains consisting of chromium, oxygen and phosphorus atoms and Cations - at least one metal from group II A of the Periodic Table of the Elements (metal cations) consists or exist and is or are at least saturated with metal cations in the chemical sense. 2. Layer material according to claim 1, characterized in that the electrical alloy contains iron . 5 · Layer material according to claim 1 or 2, characterized in that it is used as metal cations Contains calcium and / or magnesium cations. 4-. Layer material according to Claim 3, characterized in that it has magnesium cations as metal cations contains. 5 layer material according to at least one of claims 1 to 4, 109828/1883 characterized in that the insulating layer (s) is or are at least about 0.001 mm thick. 6. Layer material according to claim 5j characterized by g e k en η, that the insulating layer (s) is at most 0.0076 mm thick or. are. 7 · Layer material according to claim 6, characterized in that the insulating layer (s) as metal cations Magnesium catalysis inclined. contains or contains and 0.0015 to 0.0051 mm thick is or are. 8. Layer material according to at least one of claims 1 to 7 j characterized g e k e η η ζ ei c h η e t that it has a plurality of alloy layers, each by insulating layers against adjacent alloy layers are electrically isolated. 9. A method for producing layer material according to at least one of claims 1 to 8, characterized in that g e k e η η · draws that one on the electric alloy one aqueous ammonium, chromate and phosphate ions and cations of at least one metal from group II A des Periodic table of the elements (metal cations) containing solution applied with metal cations in the chemical Sense is at least saturated and, based on the total amount of ammonium, chromate, Phosphate and metal cations, 6 to 18 mol% ammonium, 21 to 63 mol% phosphate, 8 to 24 mol% chromate and .15 to £ 4 mol% contains metal cations, with the proviso that 1 09828 / that at least 1 mol% of or of metal cations in the form of the oxide, hydroxide, carbonate, bicarbonate and / or chromate of the metal in question is incorporated or is present in the solution. '10. Method according to claim 9 »characterized in that that the aqueous solution is applied to an iron-containing electrical alloy. 11. The method according to claim 9 or 10, characterized in that an aqueous solution is used which, based on their total content of ammonium, phosphate, chromate and metal cations, 9 to 15 mol% ammonium, 30 to 55 mol% phosphate, 11 to 20 mol% chromate and contains 25 to 35 mole percent metal cations. 12. The method according to at least one of claims 9 to 11, characterized in that an aqueous solution is used which contains magnesium as metal cations and / or contains calcium ions. 13. The method according to claim 12, characterized in that that an aqueous solution is used which contains magnesium ions as metal cations. 14. The method according to at least one of claims 9 to 13, characterized in that the layer produced by treatment with the aqueous solution by heating the alloy layer surface to a temperature of about 204.4 to about 1037.8 ⁰ C for about 2 seconds 109828/1883 is cured or baked for about 4 hours. Method according to at least one of claims 9 to 14, characterized in that as an electrodic alloy a silicon steel is used. 16.Aqueous solution for performing the method according to at least one of claims 9 to 15 _? characterized in that, apart from water, it consists essentially of ammonium, chromate, phosphate and metal cations and, based on the total content of said ions, 6 to 18 mol% ammonium, 21 to 63 mol% phosphate, 8 to 24 mol% of chromate and 15 to 4-5 mol% of metal cations is obtained, with the proviso that the solution is at least saturated with metal cations in the previous sense and at least 1 mol% of the metal cations in the form of the oxide, hydroxide, carbonate, bicarbonate and / or chromate of the metal in question are incorporated or are present. 17 solution according to claim 16, characterized in that that they, based on the total content of ammonium, phosphate, chromate and metal cations, 9 to 15 mol% Ammonium, JO up to 55 mol% phosphate, 11 to 20 mol% Contains chromate and 25 to 55 mol% metal cations. 18. Solution according to claim 16 or 17, characterized in that it contains magnesium and / or contains calcium ions. 109828/18 8 3 206112A Solution according to claim 18, characterized net 'that σ-ie contains magnesium ions as metal cations . 109828/1883