WO2014049016A1 - Poudre à aimantation temporaire non corrosive - Google Patents

Poudre à aimantation temporaire non corrosive Download PDF

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Publication number
WO2014049016A1
WO2014049016A1 PCT/EP2013/070008 EP2013070008W WO2014049016A1 WO 2014049016 A1 WO2014049016 A1 WO 2014049016A1 EP 2013070008 W EP2013070008 W EP 2013070008W WO 2014049016 A1 WO2014049016 A1 WO 2014049016A1
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WIPO (PCT)
Prior art keywords
soft
inhibitor
magnetic powder
alkenyl
alkynyl
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PCT/EP2013/070008
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English (en)
Inventor
Sandro Pagano
Jae Hyung Hwang
Günter ÖTTER
Roland BÖHN
Roman Zieba
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Basf Se
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Publication of WO2014049016A1 publication Critical patent/WO2014049016A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
    • H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
    • H01F1/20—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder
    • H01F1/22—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together
    • H01F1/24—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated
    • H01F1/26—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys in the form of particles, e.g. powder pressed, sintered, or bound together the particles being insulated by macromolecular organic substances
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C2202/00—Physical properties
    • C22C2202/02—Magnetic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F3/00—Cores, Yokes, or armatures
    • H01F3/08—Cores, Yokes, or armatures made from powder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0206—Manufacturing of magnetic cores by mechanical means
    • H01F41/0246—Manufacturing of magnetic circuits by moulding or by pressing powder

Definitions

  • Non-corrosive Soft-Magnetic Powder Description The invention relates to a process of preparing non-corrosive soft-magnetic powder. The invention further relates to a product prepared by the process as well as the use of such a soft-magnetic powder.
  • Iron-based powders have long been used as a base material in the manufacture of electronic components. Other uses of such powders include metal injection molded parts, powder metallurgy, and various specialty products, such as food supplements.
  • a popular application of soft-magnetic powder includes magnetic core components, which serve as piece of magnetic material with a high permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, inductors and magnetic assemblies. These components are usually produced in different shapes and sizes by molding soft- magnetic powder in a die under high pressure.
  • the two key characteristics of the magnetic core component are the magnetic permeability and the core loss characteristic.
  • the magnetic permeability of a material provides an indication of its ability to become magnetized or its ability to carry a magnetic flux. Permeability is defined as the ratio of the induced magnetic flux to the magnetizing force or field intensity.
  • the hysteresis loss is caused by the necessary expenditure of energy to overcome the retained magnetic forces within the core component.
  • the eddy current loss is caused by the production of electric currents in the core component due to the changing flux caused by AC conditions and basically results in a resistive loss.
  • devices for high frequency applications are sensitive to core losses and in order to reduce losses due to eddy currents an improved insulating property is desired.
  • the simplest way of achieving this is thickening the insulating layer for each particle.
  • rust causes reduction in resistance and a rust inhibiting layer can reduce such losses.
  • the thicker the insulation layer is the lower the core density of soft-magnetic particles gets and the magnetic flux density decreases.
  • an attempt to increase the magnetic flux density by compression-molding under high pressure may lead to larger strain in the core and, hence, to a higher hysteresis loss.
  • WO 2007/084 363 A2 relates to a method for preparing metallurgical powder compositions and compacted articles made thereof.
  • the metallurgical powder composition comprises a base-metal powder, which is at least partially coated by metal phosphate and a particulate internal lubricant.
  • the internal lubricants used include, for example, polyamides, Cs to C30 fatty acids, metal salts of polyamides, metal salts of C5 to C30 fatty acids, ammonium salts of C5 to C30 fatty acids, lithium stearate, zinc stearate, manganese stearate, calcium stearate, ethylene bis-stearamide, polyethylene waxes, polyolefins, and combinations thereof.
  • phosphate coating and internal lubricant the lubricity of the metal particles and the compacted parts can be increased, while reducing the amount of organic compounds present.
  • EP 0 810 615 B1 describes a soft-magnetic powder composite core, which comprises particles with insulating layers.
  • the soft-magnetic particles are treated by a solution comprising a phosphating solution, which comprises a solvent and phosphate salts.
  • the solution comprises a surfactant and a rust inhibitor, which is an organic compound containing nitrogen and/or sulfur having a lone pair of electrons suppressing the formation of iron oxide.
  • EP 0 765 199 B1 discloses admixing powder compositions of iron-based particles with a thermoplastic material and a lubricant selected from the group of stearates, waxes, paraffins, natural and synthetic fat derivatives and oligomers of polyamide type.
  • the obtained mixture is compacted at a temperature below the glass-transition temperature or melting point of the thermo-plastic resin and the compacted product is heated in or- der to cure the thermoplastic resin.
  • the lubricant added to the thermoplastic material the process is less time consuming, but an essential improvement in the soft- magnetic properties cannot be reached.
  • CN 101 525 563 A for example refers to an after polishing detergent including a corrosion inhibitor that is used to protect the surface of a processing object from corrosion, when the chemical- mechanical polishing-cleaning is carried out.
  • CN 100 588 743 A discloses an acid solution for treating magnesium alloy surfaces, which comprises two acids, a corrosion in- hibitor and a wetting agent for activation of magnesium alloy surface to form a compact film.
  • US 5,415,805 A describes a composition and method for inhibiting corrosion of iron and iron containing metals in sulfur mines.
  • the composition comprises an aqueous solution of an alcohol, an acid, a fatty imidazoline, and an ethoxylated fatty diamine, and an aqueous solution of a molybdate compound or salt thereof.
  • an object of the invention to provide a process for coating soft-magnetic powder and a corresponding soft-magnetic powder that facilitates to achieve high resistivity, high permeability and non-corrosive properties when utilized in magnetic core components. Furthermore, it is an object of the invention to provide a process which allows to achieve aforementioned goals in a simple, cost-effective and uncomplicated manner. Another object of the invention is to provide electronics components including soft-magnetic powder, which require no further corrosion protection. In this context, one object of the invention is to provide soft-magnetic powder that allows producing electronic components without further corrosion protection layers.
  • a process for coating a soft-magnetic powder comprising the step of treating the soft-magnetic powder with a solution containing:
  • At least one first inhibitor which is a 5- to 12-, preferably 5- to 9-, particularly pref- erably 5- to 7-membred heterocyclic compound containing at least one substituted or unsubstituted ring-nitrogen atom and at least one ring-carbon atom, wherein one ring atom, preferably one ring-carbon atom, is substituted with C2 - C28 alkyl, C2 - C28 alkenyl or C2 - C28 alkynyl, preferably Cs - C26 alkyl, Cs - C26 alkenyl or Cs - C26 al- kynyl, more preferably C12 - C22 alkyl, C12 - C22 alkenyl or C12 - C22 alkynyl and most preferably C14 - C-is alkyl, C14 - C-is alkenyl or C14 - C-is alkynyl; and optionally
  • R 1 indicates C2 - C28 alkyl, C2 - C28 alkenyl or C2 - C28 alkynyl, preferably Cs - C26 al- kyl, Cs - C26 alkenyl or Cs - C26 alkynyl, more preferably C12 - C22 alkyl, C12 - C22 alkenyl or C12 - C22 alkynyl and most preferably C14 - Cis alkyl, C14 - Cis alkenyl or C14 - C18 alkynyl;
  • R 2 and R 3 independently of each other indicate H , Ci - C6 alkyl, C2 - C6 alkenyl, Ci - C6 alkynyl, C3 - C7 cycloalkyl or C6 - C12 aryl.
  • -COOH also includes carboxylate which are preferably derivatives of a carboxylic acid function, in particular a metal carboxylate, a carboxylic ester function or a carboxamide or function.
  • carboxylate are preferably derivatives of a carboxylic acid function, in particular a metal carboxylate, a carboxylic ester function or a carboxamide or function.
  • these include, for example, the esters with Ci-C4-alkanoles such as methanol, ethanol, n-propanol, isopropanol, n- butanol, sec-butanol and tert-butanol.
  • the invention further pertains to a soft-magnetic powder containing at least one first inhibitor of class (A) as specified above and optionally at least one second inhibitor of class (B) as specified above, a soft-magnetic powder obtained by aforementioned process and uses of such powder in electronic components.
  • a soft-magnetic powder obtained by aforementioned process and uses of such powder in electronic components.
  • the following description concerns the process as well as the product proposed by the invention.
  • preferred embodiments of the inhibitor classes (A) and (B), the inhibitor composition and the soft-magnetic powder apply to the process for treating the soft-magnetic pow- der and the treated soft-magnetic powder alike.
  • the invention also concerns the use of the treated soft-magnetic powder for manufacturing electronic components, in particular magnetic core components as used in electrical, electro-mechanical and magnetic devices such as electromagnets, transformers, electric motors, inductors and magnetic assemblies.
  • Further uses of the coated soft- magnetic powder include manufacture of Radio-Frequency Identification (RFID) tags and manufacture of elements reflecting or shielding electromagnetic radiation.
  • RFID Radio-Frequency Identification
  • the invention provides a process for coating soft-magnetic powder and the corre- sponding treated powder which is optimally suitable for manufacturing electronic components.
  • the soft-magnetic powder coated according to the invention allows to achieve high resistivity, high permeability and non-corrosive properties when used for manufacture of electronic components, such as magnetic core components.
  • the invention further allows to flexibly adapt such characteristics by modifying the treatment solution and the inhibitor content used therein.
  • a high batch-to-batch con- sistency can be achieved, which again allows for reliable production of electronic components.
  • the soft-magnetic powder coated according to the invention facilitates to prepare electronic components with unique electromagnetic performance characteristics. Additionally, electronic components comprising the soft-magnetic powder coated according to the invention do not require further layers for corrosion protection saving space and production costs.
  • a soft-magnetic powder of the present invention includes a plurality of particles composed of a soft-magnetic material.
  • Such powders comprise particles with a mean size between 0.5 and 250 ⁇ , preferably between 2 and 150 ⁇ , more preferably between 2 and 10 ⁇ .
  • These particles may vary in shape. In respect of the shape, numerous variants known to the person skilled in the art are possible.
  • the shape of the powder particles may, for example, be needle-shaped, cylindrical, plate-shaped, teardrop- shaped, flattened or spherical.
  • Soft-magnetic particles with various particle shapes are commercially available. Preferred is a spherical shape as such particles can be coated more easily, which in fact results in a more effective insulation against electrical current.
  • an elemental metal an alloy or a mixture of one or more elemental metal(s) with one or more alloy(s) may be employed.
  • Typical elemental metals comprise Fe, Co and Ni.
  • Alloys may include Fe-based alloys, such as Fe-Si alloy, Fe- Si-Cr alloy, Fe-Si-Ni-Cr alloy, Fe-AI alloy, Fe-N alloy, Fe-Ni alloy, Fe-C alloy, Fe-B alloy, Fe-Co alloy, Fe- P alloy, Fe-Ni-Co alloy, Fe-Cr alloy, Fe-Mn alloy, Fe-AI-Si alloy and ferrites, or rare earth Fe-based alloy, such as Nd-Fe-B alloy, Sn-Fe-N alloy, Sm-Co alloy, Sm-Co-Fe-Cu-Zr alloy and Sr-ferrite.
  • Fe or Fe-based alloys such as Fe-Si-Cr, Fe-Si or Fe-AI-Si, serve as soft-magnetic material.
  • Fe serves as soft-magnetic material and the soft-magnetic powder is a carbonyl iron powder.
  • Carbonyl iron can be obtained according to known processes by thermal decomposition of iron pentacarbonyl in a gas phase, as described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, Vol. A 14, page 599 or in DE 3 428 121 or in DE 3 940 347, and contains particularly pure metallic iron.
  • Carbonyl iron powder is a gray, finely divided powder of metallic iron having a low con- tent of secondary constituents and consisting essentially of spherical particles having a mean particle diameter of up to 10 ⁇ .
  • Unreduced carbonyl iron powder which is preferred in the present context, has an iron content of >97% by weight (here based on the total weight of the powder), a carbon content of ⁇ 1.5% by weight, a nitrogen content of ⁇ 1 .5% by weight and an oxygen content of ⁇ 1 .5% by weight.
  • Reduced carbonyl iron powder which is particularly preferred in the process of the present invention, havs an iron content of >99.5% by weight (here based on the total weight of the powder), a carbon content of ⁇ 0.1 % by weight, a nitrogen content of ⁇ 0.01 % by weight and an oxygen content of ⁇ 0.5% by weight.
  • the mean diameter of the powder particles is preferably from 1 to 10 ⁇ and their specific surface area (BET of the powder particles) is preferably from 0.2 to 2.5 m 2 /g.
  • the soft-magnetic powder is pre-treated, preferably phosphated.
  • Phosphating may include coating the soft-magnetic material with an insulating amorphous compound, such as phosphoric acid or salts thereof with at least one element selected from the group consisting of Al, Si, Mg, Y, Ca, B, Zr, and Fe. Since these materials provide reasonably good insulation properties and sufficiently couple a metal to an organic compound, they are particularly suitable for pre-treating particles of the soft-magnetic powder. Furthermore, the pre-treatment prepares the surface of the powder particles such that the inhibitor(s) contained in the solution ad- here more easily.
  • the average thickness of the coating stemming from the pre-treatment may lie between 1 nm to 1 ⁇ , preferred between 1 and 50 nm.
  • the amount of the coating with respect to the soft-magnetic material is not higher than 4 wt%, thus, a sig- nificant decrease in magnetic flux density of the magnetic core obtained by molding the soft-magnetic powder can be prevented.
  • One method of pre-treating the soft-magnetic particles includes mixing the soft- magnetic powder with phosphoric acid or salts thereof optionally mixed with an organic solvent.
  • the person skilled in the art may choose an appropriate time and appropriate temperature conditions to form an iron phosphate layer.
  • the pre-treatment may for example be carried out at room temperature for a period of 10 min to 10 hours.
  • the solvent may then be evaporated by elevating the temperature to form dry powder.
  • phosphating the phosphor content typically varies between 0.01 and 1 %, preferably between 0.02 and 1 % by weight of the dry powder.
  • the at least one first inhibitor of class (A) is a 5- to 12-, preferably 5- to 9-, particularly preferably 5- to 7-membred heterocyclic compound containing at least one substituted or unsubstituted ring-nitrogen atom and at least one ring- carbon atom, wherein one ring atom, preferably one ring-carbon atom, is substituted with C2 - C28 alkyl, C2 - C28 alkenyl or C2 - C28 alkynyl, preferably Cs - C26 alkyl, Cs - C26 alkenyl or Cs - C26 alkynyl, more preferably C12 - C22 alkyl, C12 - C22 alkenyl or C12 - C22 alkynyl and most preferably C14 - C-is alkyl, C14 - C-is alkenyl or C14 - C-is alkynyl.
  • Preferred heterocyclic compounds are imidazole, imidazoline, imidazolidine, benzimid- azole, benzimidazoline, benzimidazolidine, thiazole, thiazoline, thiazolidine, benzthia- zole, benzthiazoline, benzthiazolidine, oxazole, oxazoline, oxazolidine, benzoxazole, benzoxazoline, benzoxazolidine, pyridine, collidine, pyrimidine, triazole, benzotriazole, triazoline or tetrazole.
  • heterocycles are imidazole, imidazoline, imidaz- olidine, benzimidazole, benzimidazoline or benzimidazolidine. Most preferred heterocycles are imidazole, imidazoline, imidazolidine.
  • the ring-nitrogen atom may be substituted by a monovalent straight or branched carbon chain Rchain having from 2 to 10, preferably from 2 to 6 carbon at- oms, wherein the chain is substituted by at least one of the groups N H2, OH , ORY, OC(0)R Y , OC(0)RZ, COOH , C0 2 RY, wherein RY means a monovalent straight or branched chain including from 1 to 10 carbon atoms, wherein RY may also be substituted by one or more substituents selected from R Y , R z , F, CI, Br, I, OH, CN, N0 2 , CF 3 , NH 2 , NHR Y , NHR Z , N0 2 , C0 2 H, C0 2 R Y , C0 2 Rz, CO2NH2, SH, SO3H, SO2NH2, CHO, COCH3, CH2OH, wherein Rz means aromatic hydrocarbon radicals having from 6 to 8 ring
  • RY means methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert- butyl, n-pentyl, isopentyl, 1 -methylbutyl, tert-pentyl, neopentyl, n-hexyl, 3-hexyl, 2- methyl-1 -pentyl, 3-methyl-1 -pentyl, 4-methyl-1 -pentyl, 2-methyl-2-pentyl, 3-methyl-2- pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1 -butyl, 2,3-dimethyl-1 -butyl, 3,3-dimethyl-1 -butyl, 2-ethyl-1 -butyl, 2,3-dimethyl-2-butyl, 3,3- dimethyl-2-butyl,
  • Rz is preferably unsubstituted or substituted phenyl, naphthyl, anthracenyl, phenan- threnyl, naphthacenyl, chrysenyl, pyrenyl, and particularly preferably phenyl or naphthyl.
  • Rz is for example, 2-, 3- and 4-methylphenyl, 2,4-, 2,5-, 3,5- and 2,6- dimethylphenyl, 2,4,6-trimethylphenyl, 2-, 3- and 4-ethylphenyl, 2,4-, 2,5-, 3,5- and 2,6- diethylphenyl, 2,4,6-triethylphenyl, 2-, 3- and 4-propylphenyl, 2,4-, 2,5-, 3,5- and 2,6- dipropylphenyl, 2,4,6-tripropylphenyl, 2-, 3- and 4-isopropylphenyl, 2,4-, 2,5-, 3,5- and 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl, 2-, 3- and 4-butylphenyl, 2,4-, 2,5-, 3,5- and 2,6-dibutylphenyl, 2,4,6-tributylphenyl, 2-, 3- and 4-isobutylphenyl,
  • Rchain is a monovalent straight or branched carbon chain having from 2 to 10 carbon atoms wherein the chain is substituted by at least one of group -OH, for example 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl, 2-hydroxy-2,2-dimethylethyl, 5-hydroxy-3-oxapentyl, 6-hydroxyhexyl, 7-hydroxy-4- oxaheptyl, 8-hydroxy-4-oxaoctyl, 8-hydroxy-3,6-dioxaoctyl, and the like.
  • group -OH for example 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl, 2-hydroxy-2,2-dimethylethyl, 5-hydroxy-3-oxapentyl, 6-hydroxyhexyl, 7-hydroxy-4- oxaheptyl, 8-hydroxy-4-oxaoctyl,
  • Rchain is a monovalent straight or branched carbon chain having from 2 to 10 carbon atoms wherein the chain is substituted by at least one of group -COOH, for example carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, 5- carboxypentyl, 6-carboxyhexyl, 7-carboxyheptyl, 8-carboxyoctyl, 9-carboxynonyl, 10- carboxydecyl, 12-carboxydodecyl and 14-carboxytetradecyl.
  • group -COOH for example carboxymethyl, 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, 5- carboxypentyl, 6-carboxyhexyl, 7-carboxyheptyl, 8-carboxyoctyl, 9-carboxynonyl, 10- carboxydecyl, 12-carboxydodecy
  • Rchain is a monovalent straight or branched carbon chain having from 2 to 10 carbon atoms wherein the chain is substituted by at least one amino group, e.g. 2- aminoethyl, 2-aminopropyl, 3-aminopropyl, 4-aminobutyl, 6-aminohexyl and the like.
  • the heterocyclic compound is further substituted with H, Ci - Ce alkyl, C2 - Ce alkenyl, Ci - Ce alkynyl, C3 - C7 cyclo- alkyl or Ce - C12 aryl, preferably Ci - Ce alkyl and more preferably methyl.
  • the compound of formula (I) is derived from a fatty acid.
  • the fatty acid may be saturated or unsaturated, preferably unsaturated, and may be chosen from the group consisting of myristoleic acid, pal- mitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, linoleic acid, li- noelaidic acid, a-linolenic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, docosahexaenoic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and cerotic acid.
  • Preferred fatty acids are palmitoleic acid, oleic acid, linoleic acid, linoelaidic acid, a-linolenic acid, lauric acid, lalmitic acid, ricinoleic acid or stearic acid.
  • Particularly preferred fatty acids have 12 to 18 carbon atoms and 1 to 4 double bonds in the fatty acid, such as oleic acid, lauric acid, ricinoleic acid and stearic acid.
  • the at least one second inhibitor of class (A) is a compound of the general formula (II):
  • R 4 indicates C2 - C28 alkyl, C2 - C28 alkenyl or C2 - C28 alkynyl, preferably Cs - C26 alkyl, Cs - C26 alkenyl or Cs - C26 alkynyl, more preferably C12 - C22 alkyl, C12 - C22 alkenyl or C12 - C22 alkynyl and most preferably C14 - C-is alkyl, C14 - C-is alkenyl or CM - C18 alkynyl.
  • X can be chosen from the group consisting of O, S, NR 5 .
  • X may be S or NR 5 and in a more preferred embodiment X is NR 5 .
  • R 5 indicates H, Ci - C6 alkyl, C2 - C6 alkenyl, Ci - C6 alkynyl, C3 - C7 cycloalkyl or C6 - C12 aryl, preferably H, Ci - C6 alkyl optionally substituted with 1 or 2 substituents from the group consisting of OH, COOH or NH2. Furthermore, the alkyl in R 5 is optionally substituted with 1 to 3 substituents from the group consisting of F, CI, Br, C, OH, Ci to C4 alkoxy, Ce to C10 aryl, CF3, CN, NH2.
  • R 6 and R 7 may be connected through a single or double bond and independently of each other indicate H, Ci - Ce alkyl, C2 - Ce alkenyl, Ci - Ce alkynyl, C3 - C7 cycloalkyl or C6 - C12 aryl.
  • R 6 and R 7 independently of each other indicate H, Ci to C6 alkyl, more preferably H or methyl.
  • the compound of formula (II) is derived from a fatty acid.
  • the fatty acid may be saturated or unsaturated, preferably unsaturated, and may be chosen from the group consisting of myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, linoleic acid, li- noelaidic acid, a-linolenic acid, arachidonic acid, eicosapentaenoic acid, erucic acid, docosahexaenoic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, Preferred fatty acids are palmitoleic acid, oleic acid, linoleic acid, linoelaidic acid, a-linolenic acid, lauric acid, lalmitic acid, ricinoleic acid and stearic acid.
  • % by weight refers to the fraction of the total weight of soft-magnetic powder unless otherwise specified.
  • the solution for treating soft-magnetic powder includes first inhibitor(s) of class (A) as specified above, optionally second inhibitor(s) of class (B) and optionally further components such as a solvent.
  • wt% refers to the fraction of total weight of soft- magnetic powder to be treated with the solution, unless explicitly stated.
  • the indication wt% is based on the total weight of soft-magnetic powder excluding other components e.g. from the solution.
  • the solution utilized in the method according to the invention preferably contains at least one inhibitor of each class (A) and (B) as specified above.
  • the solution contains more than 0.05 wt%, preferably between 0.1 and 1 .0 wt% and par- ticularly preferably between 0.10 and 0.8 wt% of the at least one first inhibitor of class (A).
  • the solution may contain more than 0.03 wt%, preferably between 0.05 and 0.6 wt% and particularly preferably between 0.1 and 0.5 wt% of the at least one second inhibitor of class (B).
  • the total fraction of inhibitor(s) contained in the solution may vary between 0.05 and 1 wt%, preferably between 0.1 and 0.5 wt%.
  • the weight ratio of inhibitor(s) of class (A) to inhibitor(s) of class (B) may lie between 0.5 and 10, preferably between 0.8 and 5 and particularly preferably between 1 and 3.
  • the solution may contain a solvent.
  • solvents are wa- ter, acetone, acetic acid, aceton-nitrile, glycerin, hexane, methyl f-butyl ether, propanol, benzene, ethanol or methanol.
  • solvents examples include aromatic hydrocarbons, such as toluene or xylene; alkyl esters, such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, isopropyl acetate, and 3-methylbutanol; alkoxy alcohols, such as methoxypropanol, methoxybutanol, ethoxypropanol; alkylben- zenes, such as ethylbenzene, isopropylbenzene; butyl glycol, butyl diglycol, alkyl glycol acetates, such as butyl glycol acetate and butyl diglycol acetate; 2-methoxy-1 - methylethyl acetate, diglycol dialkyl ethers, diglycol monoalkyl ethers, dipropylene glycol dialkyl ethers, dipropylene glycol monoal
  • the solution may be prepared by mixing at least one first inhibitor of class (A) and optionally at least one second inhibitor of class (B) with the solvent.
  • the prepared solution may then be mixed with the soft magnetic powder.
  • the method of mixing these components is not limited, and the mixing may be effected by a mixer, e.g. stirred tank, planetary mixer, paddle mixer or a kneader. After mixing the soft-magnetic powder and the solution including a solvent the mixture may be heated for the solvent to evaporate. In this manner a dry soft-magnetic powder is provided, that includes a non-corrosive thin coating.
  • the average thickness of the inhibitor coating may lie between 0.5 nm to 20 nm.
  • the ratio of inhibitor coating to the soft-magnetic material is not higher than 0.1 and preferably not higher than 0.01. Thus a significant decrease in magnetic flux densi- ty of the magnetic core obtained by molding the soft-magnetic powder can be prevented.
  • the soft-magnetic powder treated according to the process described above and the treated soft-magnetic iron powder are particularly suitable for the manufacture of elec- tronic components.
  • Electronic components such as magnetic cores may be obtained by e.g. press molding or injection molding the soft-magnetic powder.
  • the soft-magnetic powder is typically incorporated with one or more types of resin, such as epoxy resin, urethane resin, polyurethane resin, phenolic resin, amino resin, silicon resin, polyamide resin, polyimide resin, acrylic resin, polyes- ter resin, polycarbonate resin, norbornene resin, styrene resin, polyether sulfone resin, silicon resin, polysiloxane resin, fluororesin, polybutadiene resin, vinyl ether resin, polyvinyl chloride resin or vinyl ester resin.
  • resin such as epoxy resin, urethane resin, polyurethane resin, phenolic resin, amino resin, silicon resin, polyamide resin, polyimide resin, acrylic resin, polyes- ter resin, polycarbonate resin, norbornene resin, styrene resin, polyether sulfone resin, silicon resin, polysiloxane resin, fluororesin, polybutadiene resin, vinyl ether resin, polyvinyl chloride resin or vinyl ester
  • ribbon blender tumbler, Nauta mixer, Henschel mixer or supermixer or kneading machine, e.g., Banbury mixer, kneader, roll, kneader-ruder, paddle mixer, planetary mixer or monoaxial or biaxial extruder.
  • kneading machine e.g., Banbury mixer, kneader, roll, kneader-ruder, paddle mixer, planetary mixer or monoaxial or biaxial extruder.
  • the composition is used to produce a magnetic or magnetisable molding.
  • Particular moldings of this type are coil cores or coil formers, as used in electrical engineering. Coils with corresponding coil cores or coil formers are used by way of example as electromagnets, in generators, in laptop computers, in netbooks, in mobile telephones, in electric motors, in AC inverters, in electronic components in the automobile industry, in toys, and in the electronics industry.
  • the composition can moreover be used to pro- cute magnetic-field concentrators.
  • the composition of soft-magnetic powder and resin is heated and molten at a melting point of the resein, preferably the thermoplastic resin, component, and then formed into an electronic component, such as a magnetic core of de- sired shape. Then the composition is compressed in a mold to give a molding. The compression produces a molding which has high strength.
  • Another method to produce the molding includes the composition of soft-magnetic powder and resin, which is pressed in a mold at pressures up to 1000 MPa, preferably up to 500 MPa with or without heating. After compression the molding is left to cure.
  • the soft-magnetic powder treated according to the process described above or containing at least one first inhibitor of class (A) and optionally at least one second inhibitor of class (B) as described above may be used in electronic components, in particular magnetic core components as used in electrical, electro-mechanical and magnetic devices such as electromagnets, transformers, electric motors, inductors, and magnetic assemblies, manufacture of Radio-Frequency Identification (RFID) tags and for reflecting or shielding electromagnetic radiation.
  • Powder injection molding allows to produce complex metal parts cost effectively and efficiently. Powder injection molding typically includes pressing the soft-magnetic powders together with a polymer as adhesive into the desired shape, the adhesive is then removed and the powder is compacted into a solid metal part in the sintering phase. This works particularly well with carbonyl-iron powder because the spherical iron parti- cles can be packed together very tightly.
  • RFID tags Radio-Frequency Identification
  • soft-magnetic powder may be employed in printing the RFID structure.
  • electronic components manufactured of soft-magnetic powder may be used for shielding electronic devices.
  • alternating magnetic field of the radiation causes the powder particles to continuously rearrange themselves. Due to the resulting friction, the powder particles convert the energy of the electromagnetic waves into heat.
  • the coated CIP powder (100g) was mixed with epoxy resin (Epikote 1004, Momentive) by dissolving the epoxy resin (2.8g) in a solvent (20ml_; e.g. acetone, methylethylke- tone).
  • a solvent 20ml_; e.g. acetone, methylethylke- tone.
  • the coated CIP is stirred together with the epoxy solution using a dissolver mixer (IKA, RW20 D2M, 1000 R/min). After mixing the slurry is poured in an aluminum plate, which is then put in a fume hood for 8h.
  • the resulting dry CIP epoxy plate is milled in a knife mill (Kinematica, Microtron MB550) for 10 seconds to yield the ready to press powder.
  • 6.8g ( ⁇ 0.1 g) of the ready to press powder is put into a steel mold (ring type: outer diameter 20.1 mm; inner diameter 12.5mm; resulting height approximately 5-6mm) and molded at 440MPa for a couple of seconds. From the exact mass and height of the ring the density of the ring core is calculated.
  • the ring core is wired (20 windings) with an isolated 0.85mm copper wire (Isodraht, Multogan 2000MH 62) for determination of the permeability and resistivity.
  • LRC meter E4980A Agilent was used to measure permeability of a ring core. All measurements were done at 100kHz with 0V DC bias. The test AC current of 10mA was applied to the ring core.
  • a power supply was connected in series to a voltmeter and a sample. 300 Volts were applied to a multimeter and the sample connected in series. Voltage reading of a multimeter was used to estimate the re- sistance of the sample using following equation.
  • a filter paper (Macherey-Nagel, MN640W) was placed in a plastic petri dish (0 33mm, 12mm height).1 g of the coated powder (without epoxy) was placed on the filter paper. 2ml_ of destilled water was added onto the powder and the petri dish was closed. The closed petri dish was put into a climate chamber set to 85°C and 85% relative humidity. After 24h the petri dish was removed from the climate chamber and opened. The filter paper was rinsed with water to remove the iron powder and rinsed a second time with acetone before drying. If iron oxides or hydoxides are formed the filter paper turns orange to brown or orange to brown spots are observed.
  • the corrosion resistance was evaluated by inspection of the dried filter paper: ++ corresponds to no traces of corrosion; + corresponds some small ( ⁇ 2mm) orange/brown dots or a thin ( ⁇ 2mm) line around the powder; - corresponds some (>2mm) orange/brown dots or a (>2mm) line around the powder; - complete paper is orange/brown colored.
  • test results After treatment of the carbonyl iron powder and formation of the compacted samples the permeability, resistivity and the corrosion characteristics were determined as described above. The results for examples 1 to 1 1 are given in Table 2. In comparison Table 3 specifies in line 1 the permeability, resistivity and corrosion resistance for phosphated carbonyl iron powder that has not been treated with inhibitors A or B. In this context, examples no. 4 and no. 5 including either inhibitor A or B illustrate the effect of each inhibitor individually on the permeability, resistivity and corrosion resistance. Whereas a treatment with inhibitor A (example no. 1 1 ) results in a high cor- rosion resistance, a reasonably high permeability but a small resistivity, treatment with inhibitor B (example no. 5) yields a high permeability and a high resistivity, but only intermediate corrosion resistance.
  • Examples 1 to 3 and 6 to 1 1 including phosphated carbonyl iron powder treated with both inhibitors show that the characteristic parameters of a compacted device, such as a magnetic core, may be optimized by adapting the contents.
  • an increasing content of inhibitor A reveals better corrosion resistance and higher resistivity.
  • a higher content of inhibitor B leads to an increase in permeability up to a threshold of about 0.3 wt%.
  • An optimal inhibitor composition is reached in example 2, where the solution for treating phosphated carbonyl iron powder contains around 0.2 wt% of inhibitor A and 0.1 wt% of inhibitor B.
  • Such a composition leads to a compacted sample core, which exhibits high permeability as well as resistivity values and a high corrosion resistance.
  • Table 3 specifies the characteristic properties of compacted samples of magnetic cores prepared of the mixtures specified in Table 1. density corrosion cha ⁇
  • Table 4 specifies a comparative example for phosphated carbonyl iron powder without further coating.
  • Table 5 specifies the characteristic properties of compacted samples of magnetic cores prepared with the mixture specified in Table 2. density corrosion cha ⁇

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Soft Magnetic Materials (AREA)

Abstract

L'invention porte sur un procédé pour l'enrobage de poudre à aimantation temporaire, qui comprend l'étape de traitement de la poudre à aimantation temporaire avec une solution contenant : A) au moins un inhibiteur, qui est un composé hétérocyclique à 5 à 12 chaînons contenant au moins un atome d'azote de cycle substitué ou non substitué et au moins un atome de carbone de cycle, un atome de cycle étant substitué par alkyle en C2-C28, alcényle en C2-C28 ou alcynyle en C2-C28 ; et éventuellement B) au moins un inhibiteur, qui est un composé représenté par la formule générale (I), dans laquelle R1 désigne un groupe alkyle en C2-C28, alcényle en C2-C28 ou alcynyle en C2-C28 ; et R2 et R3 désignent chacun indépendamment de l'autre H ou un groupe alkyle en C1-C6, alcényle en C2-C6, alcynyle en C2-C6, cycloalkyle en C3-C7 ou aryle en C6-C12. L'invention porte en outre sur une poudre à aimantation temporaire contenant des inhibiteurs de la classe A) et de la classe B), sur l'utilisation d'une telle poudre ainsi que sur un composant électronique comprenant une telle poudre.
PCT/EP2013/070008 2012-09-27 2013-09-25 Poudre à aimantation temporaire non corrosive WO2014049016A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105458279A (zh) * 2015-11-30 2016-04-06 金川集团股份有限公司 一种降低羰基铁粉碳含量的方法
WO2021123385A1 (fr) 2019-12-20 2021-06-24 Basf Se Production de poudre optimisée

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3428121A1 (de) 1984-07-31 1986-02-13 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von eisenpulver
DE3940347A1 (de) 1989-12-06 1991-06-13 Basf Ag Verfahren zur herstellung von eisenwhiskers
US5160447A (en) * 1988-02-29 1992-11-03 Kabushiki Kaisha Sankyo Seiki Seisakusho Compressed powder magnetic core and method for fabricating same
US5415805A (en) 1994-02-25 1995-05-16 Betz Laboratories, Inc. Corrosion inhibitor composition and method of use
EP0765199B1 (fr) 1994-07-18 2000-05-31 Höganäs Ab Composants a base de poudre de fer contenant de la resine thermoplastique et leur procede d'elaboration
EP0810615B1 (fr) 1996-05-28 2002-12-11 Hitachi, Ltd. Noyau composite de poudre magnétiquement doux à particules recouvertes de couches isolantes
WO2007084363A2 (fr) 2006-01-12 2007-07-26 Hoeganaes Corporation Procédés de préparation de compositions de poudres métallurgiques et articles compactés produits à partir desdites compositions
US20090087684A1 (en) * 2007-09-28 2009-04-02 Fujifilm Corporation Method of modifying surface of powder, magnetic recording medium, and coating material
CN101525563A (zh) 2008-03-03 2009-09-09 盟智科技股份有限公司 用于后研磨清洁剂的腐蚀抑制剂
CN100588743C (zh) 2007-04-09 2010-02-10 比亚迪股份有限公司 一种用于处理镁合金表面的酸性溶液及处理方法
US20110220837A1 (en) * 2007-09-07 2011-09-15 Hoya Corporation Solvent-dispersible particle
US20110233811A1 (en) * 2010-03-23 2011-09-29 Basf Se Composition for producing magnetic or magnetizable moldings, and process for producing the same

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3428121A1 (de) 1984-07-31 1986-02-13 Basf Ag, 6700 Ludwigshafen Verfahren zur herstellung von eisenpulver
US5160447A (en) * 1988-02-29 1992-11-03 Kabushiki Kaisha Sankyo Seiki Seisakusho Compressed powder magnetic core and method for fabricating same
DE3940347A1 (de) 1989-12-06 1991-06-13 Basf Ag Verfahren zur herstellung von eisenwhiskers
US5415805A (en) 1994-02-25 1995-05-16 Betz Laboratories, Inc. Corrosion inhibitor composition and method of use
EP0765199B1 (fr) 1994-07-18 2000-05-31 Höganäs Ab Composants a base de poudre de fer contenant de la resine thermoplastique et leur procede d'elaboration
EP0810615B1 (fr) 1996-05-28 2002-12-11 Hitachi, Ltd. Noyau composite de poudre magnétiquement doux à particules recouvertes de couches isolantes
WO2007084363A2 (fr) 2006-01-12 2007-07-26 Hoeganaes Corporation Procédés de préparation de compositions de poudres métallurgiques et articles compactés produits à partir desdites compositions
CN100588743C (zh) 2007-04-09 2010-02-10 比亚迪股份有限公司 一种用于处理镁合金表面的酸性溶液及处理方法
US20110220837A1 (en) * 2007-09-07 2011-09-15 Hoya Corporation Solvent-dispersible particle
US20090087684A1 (en) * 2007-09-28 2009-04-02 Fujifilm Corporation Method of modifying surface of powder, magnetic recording medium, and coating material
CN101525563A (zh) 2008-03-03 2009-09-09 盟智科技股份有限公司 用于后研磨清洁剂的腐蚀抑制剂
US20110233811A1 (en) * 2010-03-23 2011-09-29 Basf Se Composition for producing magnetic or magnetizable moldings, and process for producing the same

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Ullmann's Encyclopedia of Industrial Chemistry", vol. A 14, pages: 599

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105458279A (zh) * 2015-11-30 2016-04-06 金川集团股份有限公司 一种降低羰基铁粉碳含量的方法
WO2021123385A1 (fr) 2019-12-20 2021-06-24 Basf Se Production de poudre optimisée

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