CN100416720C - Oxidation-resistant rare earth based magnet powder and method for production thereof, compound for rare earth based bonded magnet, rare earth based bonded magnet and method for production thereof - Google Patents
Oxidation-resistant rare earth based magnet powder and method for production thereof, compound for rare earth based bonded magnet, rare earth based bonded magnet and method for production thereof Download PDFInfo
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- CN100416720C CN100416720C CNB2004800033207A CN200480003320A CN100416720C CN 100416720 C CN100416720 C CN 100416720C CN B2004800033207 A CNB2004800033207 A CN B2004800033207A CN 200480003320 A CN200480003320 A CN 200480003320A CN 100416720 C CN100416720 C CN 100416720C
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Abstract
An oxidation-resistant rare earth based magnet powder, characterized in that it has a layer containing a pigment as a primary component adhered onto its surface; a method for producing the magnet powder; a compound for a rare earth based bonded magnet; and a rare earth based bonded magnet and a method for the production thereof. The magnet powder is useful for producing a rare earth based bonded magnet which is excellent in the resistance to oxidation and also exhibits high magnetic characteristics.
Description
Technical field
The present invention relates to oxidation-resistant rare earth based magnet powder and manufacture method thereof, this magnet powder is suitable for making not only excellent in oxidation resistance but also the outstanding rare earth based bonded magnet of magnetic property, relate to the compound that is used for rare earth based bonded magnet simultaneously, and rare earth based bonded magnet and manufacture method thereof.
Background technology
Rare earth based bonded magnet be by use thermoplastic resin or thermosetting resin etc. as binding agent with rare earth based magnet powder, for example with R-Fe-B (wherein R the represents rare earth element) based magnet powder of Nd-Fe-B based magnet powder representative, be shaped to that reservation shape makes.Owing to added resinoid bond, the magnetic property of these magnets is worse than rare-earth based sintered magnet; Yet, compare them with ferromagnet and still have sufficiently high magnetic property, and have the outstanding performance that rare-earth based sintered magnet does not possess, for example obtain having the magnet of complexity or thin shape easily, or the magnet of radial anisotropic.Therefore, particularly at miniature motor for example in spindle drive motor and the stepping motor, rare earth based bonded magnet has obtained using widely, and in recent years the demand of rare earth based bonded magnet is constantly increased.
Though rare earth based magnet powder has the excellent magnetism energy, owing to have a high proportion of R or Fe in forming, so it is easy to take place corrosion or oxidation.Therefore, in making rare earth based bonded magnet, the resinoid bond of rare earth based magnet powder with dissolving or fusion (softening) mixed so that prepare the powdery parent material that comprises this magnet powder, and its surface is coated by resinoid bond, and this parent material is called " compound "; By this compound is carried out injection moulding, pressure forming, thereby or extrusion molding it be shaped to predetermined shape obtain end article; In using the situation of thermosetting resin as resinoid bond, further heat this formed body with this resinoid bond that hardens so that obtain to have the goods of its net shape.Yet, even by this way rare earth based bonded magnet is made goods, because a small amount of acid that exists, alkali or water are to the corrosion of magnet powder, the rare earth based magnet powder that is exposed on the magnet surface can issue the erosion of getting rusty in air even in about 100 ℃ temperature, or oxidation gradually; And the deterioration or the fluctuation of magnetic property when this can cause for example magnet being assembled into element sometimes.In addition, can see through moisture and oxygen as the epoxy resin and the nylon resin of resinoid bond usually.Therefore, in using the rare earth based bonded magnet of these resins as resinoid bond, undeniable existence is because moisture or oxygen see through the possibility that this resin causes corrosion or oxidation.In addition, consider that rare earth based magnet powder is corroded or oxygenated easily, in carrying out injection molding situation, should be noted that the temperature conditions between kneading and shaping period, and in the situation of carrying out pressure forming, must in inert atmosphere or vacuum, carry out the cured after the moulding.
In addition because insufficient filling in the gap between magnet powder particle and the resinoid bond, by pressure forming with compound be shaped to bonded permanent magnet that reservation shape makes on its surface or inside comprise hole (space).Therefore, problem is a spot of acid, alkali, or water may invade and cause the corrosion gradually that is begun by magnet surface in these holes, thus can cause the generation of corrosion.As the method that addresses this is that, the amount that can consider to increase resinoid bond with respect to the magnet powder of sneaking into compound; Yet, in the situation of the mixing ratio that improves resinoid bond, because the mobile impaired meeting of compound causes manufacturing issue, perhaps because the magnet powder density that reduces can cause the magnetic property of difference.Therefore, set a upper limit (about usually 3wt%) in the mixing ratio of the relative magnet powder of resinoid bond in compound.Thus, said method may not be the effective ways that address this problem.
In order to overcome above-mentioned problem, at for example JP-A-64-11304, proposed among the JP-A-7-278602 etc. by on the surface of rare earth based magnet powder, forming the coating film that is made of the inorganic phosphate compound provides (comprising the coating film of phosphorus as component) non-oxidizability for rare earth based magnet powder method.Yet, to have the inorganic phosphate compound and make and be formed on that the rare earth based magnet powder of its lip-deep coating film is shaped to reservation shape so that when producing rare earth based bonded magnet, find because the magnetic property of this magnet of oxidation can produce significant aging phenomenon.The generation that it is envisaged that this phenomenon should be owing to the inadequate flowability of magnet powder, because the briquetting pressure that is applied between the bonded permanent magnet shaping period can produce breaking of magnet powder, therefore, for example the bursting surface of oxidized particle contacts with air easily.
In addition, as known in this area, proposed several different methods and be used for handling the hole that rare earth based bonded magnet exists.For example, method that already present hole is sealed has been proposed among the JP-A-2001-11504; This method can effectively be handled the hole that exists on the magnet surface, yet problem is that this method still is not enough to handle the inner hole that exists of magnet.Therefore, for being created in rare earth based bonded magnet surface and inner hole, as if based on the viewpoint of making the bonded permanent magnet that does not produce hole is not based on the viewpoint of sealing already present hole in the magnet, and the method for researching and solving this problem like this is more suitable.For example, the method that the use nodular powder described in the JP-A-5-129119 is made bonded permanent magnet is based on this viewpoint, and this method has reduced the generation of hole by promote the densification of formed body during pressure forming; This method comprises: form the coating film of solid resin on the surface of magnet powder nuclear, use the liquid resin coating film that places therebetween to adhere on this surface than the thinner magnet powder of this magnet powder nuclear then.This method merits attention, yet problem is the technology that need contain many steps.
Therefore, target of the present invention provides and is applicable to the oxidation-resistant rare earth based magnet powder of making rare earth based bonded magnet and the method for making this powder, wherein this magnet not only has excellent non-oxidizability but also has good magnetic property, and the compound that is provided for rare earth based bonded magnet, the method for rare earth based bonded magnet and this magnet of manufacturing.
Summary of the invention
Realized the present invention based on above-mentioned technical background, and in order to achieve the above object, according to a first aspect of the invention and feature, provide oxidation-resistant rare earth based magnet powder, this magnet powder is characterised in that to have on its surface and contains the adhesion layer of pigment as main component.
According to a second aspect of the invention and feature, except that first feature, this pigment is inorganic pigment.
According to a third aspect of the present invention and feature, except that second feature, this inorganic pigment is a carbon black.
According to a fourth aspect of the present invention and feature, except that first feature, this pigment is organic pigment.
According to a fifth aspect of the present invention and feature, except that the 4th feature, this organic pigment is indanthrene base pigment or phthalocyanine base pigment.
According to a sixth aspect of the invention and feature, except that first feature, the average particulate diameter of this pigment (main shaft diameter) is in the scope of 0.01 μ m to 0.5 μ m.
According to a seventh aspect of the present invention and feature, except that first feature, the average particulate diameter of this rare earth based magnet powder (main shaft diameter) is not more than 200 μ m.
According to an eighth aspect of the present invention and feature, except that the 7th feature, this rare earth based magnet powder is the HDDR magnet powder.
According to a ninth aspect of the present invention and feature, except that first feature, this rare earth based magnet powder has attached to the adhesion layer on the outmost surface, and has the intermediate layer that is formed on the lip-deep one or more coating films of this rare earth based magnet powder.
According to a tenth aspect of the present invention and feature, except that the 9th feature, being formed on the lip-deep coating film of rare earth based magnet powder is the coating film that is formed by the inorganic phosphate compound.
According to an eleventh aspect of the present invention and feature, except that the 9th feature, being formed on the lip-deep coating film of rare earth based magnet powder is the coating film that is formed by metal.
According to a twelfth aspect of the present invention and feature, the method of making oxidation-resistant rare earth based magnet powder is provided, this magnet powder has in its surface and comprises the adhesion layer of pigment as main component, the method is characterized in that it comprises mixes rare earth based magnet powder with the Treatment Solution that comprises pigment, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is carried out drying.
According to the 13 aspect of the present invention and feature, except that the 12 feature, this method comprises mixes rare earth based magnet powder with the Treatment Solution that comprises pigment, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is filtered and obtain.
According to the 14 aspect of the present invention and feature, except that the 12 feature, this pigment accounts for the 5wt% to 33wt% of the Treatment Solution that contains pigment.
According to the 15 aspect of the present invention and feature, except that the 12 feature, this Treatment Solution that comprises pigment comprises organic dispersion medium.
According to the 16 aspect of the present invention and feature, the method of making oxidation-resistant rare earth based magnet powder is provided, this powder have attached to outmost surface and comprise the adhesion layer of pigment as main component, and be formed with the intermediate layer of one or more coating films on the surface of this rare earth based magnet powder, the method is characterized in that it comprises mixes rare earth based magnet powder with the Treatment Solution that contains pigment, and be formed with one or more layers coating film on the surface of this powder, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its outmost surface carried out drying.
According to the 17 aspect of the present invention and feature, the compound that is used for rare earth based bonded magnet is provided, this compound is characterised in that it comprises oxidation-resistant rare earth based magnet powder and resinoid bond according to first feature.
According to the 18 aspect of the present invention and feature, rare earth based bonded magnet is provided, it is characterized in that using according to the compound that is used for rare earth based bonded magnet of the 17 feature and be shaped to predetermined shape.
According to nineteen of the present invention aspect and feature, the method of making rare earth based bonded magnet is provided, the method is characterized in that it comprises that use is shaped to predetermined shape according to the compound that is used for rare earth based bonded magnet of the 17 feature and with the technology that comprises at least one pressure forming step with it, can heat and harden this formed body if necessary subsequently.
According to the 20 aspect of the present invention and feature, except that the nineteen feature, the pressure by 0.1GPa to 1GPa carries out pressure forming.
According to the present invention, the oxidation-resistant rare earth based magnet powder that is used to make rare earth based bonded magnet is provided, this magnet not only has excellent non-oxidizability but also has good magnetic property, and provide the method for making this magnet powder, the compound that is used for rare earth based bonded magnet, the method for rare earth based bonded magnet and this magnet of manufacturing.
Description of drawings
Fig. 1 is the curve chart of example I, has shown to heat the test measurement result of magnetic flux degeneration factor (irreversible demagnetization coefficient) afterwards, and this heating test is included in the air heated 500 hours down at 100 ℃.
Fig. 2 is and the similar curve chart of Fig. 1 that just the heating test is included in the air and heated 100 hours down at 150 ℃.
Fig. 3 is the chart of example I, has shown the surperficial number of going up the hole that exists.
Fig. 4 is the curve chart of example I, has shown immersion time in water and the relation between the weight change rate.
Fig. 5 is the curve chart of example II, has shown to heat the test measurement result of magnetic flux degeneration factor (irreversible demagnetization coefficient) afterwards, and this heating test is included in the air heated 500 hours down at 100 ℃.
Fig. 6 is and the similar curve chart of Fig. 5 that just the heating test is included in the air and heated 100 hours down at 150 ℃.
Embodiment
Can make by for example following method according to oxidation-resistant rare earth based magnet powder of the present invention: rare earth based magnet powder is mixed with the Treatment Solution that comprises pigment, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is carried out drying.
Comprise the method for the Treatment Solution of pigment as preparation, can mention and for example comprising, use ammoniacal liquor etc. the pH of this alkalescent water to be controlled at 6.5 to 9.0 scope the method for pigment dispersing in the alkalescent water.The pH value of Treatment Solution is controlled at the corrosion of 6.5 to 9.0 scopes with the rare earth based magnet powder avoiding this Treatment Solution and cause.Consider to guarantee good operating characteristics, the viscosity of this Treatment Solution is preferably in the scope of 2cP to 50cP.In addition, this Treatment Solution that contains pigment can be to comprise to be dispersed in for example ethanol, the Treatment Solution of the pigment in the organic solvents such as isopropyl alcohol.
As pigment, can use two types pigment, i.e. organic pigment and inorganic pigment.As organic pigment, except that indanthrene base pigment or phthalocyanine base pigment, can mention azo group, the quinacridine ketone group, anthraquinonyl ， dioxazine base, indigo base, the thioindigo base, purple cyclic ketones (perinone) Ji ， perylene base, isoindoline base, azomethine (azomethine) azo group and diketopyrrolopyrrolecocrystals base etc.In using the situation of organic pigment as pigment, having adhesion layer and this adhesion layer on its surface comprises organic pigment and can provide suitable viscoplasticity and excellent flowability to the compound of the rare earth based bonded magnet that comprises resinoid bond as the rare earth based magnet powder of main component, simultaneously, the organic pigment that constitutes adhesion layer can absorb and the relaxation pressure shaping period between put on the pressure of compound; Therefore, consider that preventing that magnet powder from breaking produces new break surface, this situation is preferred.In addition, the organic pigment of some types can give bonded permanent magnet high resistivity.Especially, because indanthrene base pigment and phthalocyanine base pigment have excellent corrosion resistance and thermal endurance, they can be called preferred organic pigment.
As inorganic pigment, can mention carbon black, titanium dioxide, iron oxide, chromium oxide, zinc oxide, aluminium oxide, zinc sulphide, talcum, mica, calcium carbonate etc.In using the situation of inorganic pigment as pigment.Have adhesion layer and this adhesion layer on its surface and comprise inorganic pigment and preferably can provide special excellent antioxidation, because this adhesion layer has excellent impermeability to oxygen and aqueous vapor to magnet powder as the rare earth based magnet powder of main component.Carbon black can be called preferred inorganic pigment.
Consider and guarantee pigment uniform dispersiveness in comprising the Treatment Solution of this pigment, the average particulate diameter of this pigment (main shaft diameter) is preferably in the scope of 0.01 μ m to 0.5 μ m.If average particulate diameter is less than 0.01 μ m, the production of this pigment difficulty that becomes not only, thus and be easy in Treatment Solution, take place the infringement operating characteristics of reuniting.If average particulate diameter surpasses 0.5 μ m, the excessive precipitation that causes thereby the proportion in the Treatment Solution will become.
The scope of pigment content is preferably 5wt% to 33wt% in the Treatment Solution.If its content is lower than 5wt%, can not form the adhesion layer that comprises enough high quantity pigment on the surface of rare earth based magnet powder, therefore, probably this can cause and can not provide excellent non-oxidizability for magnet powder.If its content surpasses 33wt%, this pigment may take place to reunite in Treatment Solution or precipitation produces bad dispersiveness thus.Therefore, the scope of pigment content 10wt% to 30wt% more preferably in the Treatment Solution.
Preferably in comprising the Treatment Solution of pigment, add organic dispersion medium.The purpose of using this organic dispersion medium is to suppress the reunion or the precipitation of the pigment in the Treatment Solution.Consider and realize above-mentioned target, and consider affinity and cost with pigment, the preferred organic dispersion medium that uses is an anion decentralized medium (aliphat polybasic carboxylic acid for example, the salt of polyether polyester carboxylic acid, the salt of macromolecule polyester acid polyamine, salt of macromolecular multi-component carboxylic acid long-chain amine or the like), nonionic decentralized medium (carboxylate for example, sulfonate, or the ammonium salt of polyoxyethylene alkyl ether or Isosorbide Dinitrate or the like), fractionated polymer dispersion media (carboxylate for example, sulfonate, or the ammonium salt of soluble epoxide thing; The styrene-propene acid copolymer, glue or the like).
The scope of the addition of organic dispersion medium 9wt% to 24wt% preferably in the Treatment Solution.If this addition is lower than 9wt%, may reduce dispersing of pigments.On the other hand, if addition surpasses 24wt%,, the viscosity of Treatment Solution can damage operating characteristics thereby may becoming too high.
Can make oxidation-resistant rare earth based magnet powder by the following method, for example, the rare earth based magnet powder immersion is prepared and comprises in the Treatment Solution of pigment with aforementioned manner, mix and stirring, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is leached dry products therefrom.Be used for rare earth based magnet powder immerse the Treatment Solution comprise pigment mix subsequently and stir be generally 1 to 20 minute total time, but this time is depended on the amount of rare earth based magnet powder.On with its surface, be attached with in the situation that the rare earth based magnet powder of the Treatment Solution that contains pigment leaches,, pigment more closely be adsorbed onto on the surface of magnet powder by using filtration under diminished pressure or pressure filtration.Can not cause the deterioration of magnetic property in order to provide non-oxidizability to rare earth based magnet powder, preferably by air dry or at inert atmosphere (nitrogen for example, argon gas or the like) carries out drying in, perhaps by under 80 ℃ to 120 ℃, carrying out heat drying in a vacuum.In the situation of using heat drying,, be generally 20 minutes to 2 hours drying time though depend on the amount of rare earth based magnet powder drying time.Present lumps if be attached with the rare earth based magnet powder that contains the pigment Treatment Solution on the surface that so leaches, carry out drying after preferably this agglomerate being pulverized.In addition, can be sprayed onto by the Treatment Solution that will contain pigment and obtain being attached with on the surface rare earth based magnet powder that contains the pigment Treatment Solution on the rare earth based magnet powder.
Obtain in the above described manner on the rare earth based magnet powder surface, form comprise pigment and can provide excellent non-oxidizability to magnet powder as the adhesion layer of main component, yet the formation of this adhesion layer is not the chemical reaction that participates in by this magnet powder composition wherein, but the suction-operated of the molecular separating force by nano-scale micro pigment particle on the magnet powder surface.Therefore, thus for example not existing the character of this magnet powder near surface to change in its forming process makes the problem of magnetic property variation.Therefore, by using according to oxidation-resistant rare earth based magnet powder of the present invention, can produce the rare earth based bonded magnet that not only has excellent non-oxidizability but also have fine magnetic property.
In addition, use rare earth based bonded magnet to have excellent non-oxidizability, not only because this magnet powder has excellent non-oxidizability according to oxidation-resistant rare earth based magnet powder manufacturing of the present invention.Usually, in the moulding of bonded permanent magnet, because the inadequate flowability of magnet powder, the briquetting pressure that adds between the shaping period of bonded permanent magnet can cause breaking of magnet powder; Therefore, thus existing magnet powder for example to break produces the situation of easily oxidized particle break surface.Yet, in the situation of using oxidation-resistant rare earth based magnet powder of the present invention, it is believed that thereby the granules of pigments that constitutes the lip-deep adhesion layer of magnet powder can show the flowability that lubrication can be improved magnet powder between the bonded permanent magnet shaping period, and suppressed to add the generation on the easy oxidation scission surface of the particle that briquetting pressure causes magnet powder to break causing.
In addition; moulding for rare earth based bonded magnet; the working pressure forming method or comprise pressure forming and the forming method of the combination of roll-in (for example; referring to " F.Yamashita; Applications Of Rare-Earth Magnets to the Small motor industry; pp. 100-111; Proceedings of the seventeenth internationalworkshop; Rare Earth Magnets and Their Applications; August18-22; 2002, Newark, Delaware; USA; Edited by G.C.Hadjipanayisand M.J.Bonder, Rinton Press ") or the like in the situation, can produce many holes usually on the surface of the bonded permanent magnet of making.Yet in the situation of the rare earth based bonded magnet that uses oxidation-resistant rare earth based magnet powder of the present invention to make, the granules of pigments that constitutes the lip-deep adhesion layer of this magnet powder can show the effect of the sealing of portalling.It is believed that in addition and use oxidation-resistant rare earth based magnet powder of the present invention to help to realize having the rare earth based bonded magnet of superior oxidation resistance energy.
Because the present invention can not make the character (quarity) of magnet powder near surface change, even for rare earth based magnet powder with less average particulate diameter (main shaft diameter) (for example 200 μ m or littler), for example average particulate diameter is magnetic anisotropy HDDR (hydrogenation-disproportionation--desorption-reorganization) magnet powder (referring to JP-B-6-82575) of about 80 μ m to 100 μ m, this powder is so that absorption hydrogen by the rare-earth based magnetic alloy of heating in hydrogen, carrying out the desorption of hydrogen subsequently handles, cooling is then made, and can excellent non-oxidizability is provided and can not cause the deterioration of magnetic property to it.In addition, can pass through the method known in the art, for example pickling, degreasing, washing etc. is carried out preliminary treatment to rare earth based magnet powder.
In addition, according to oxidation-resistant rare earth based magnet powder of the present invention can be the magnet powder with adhesion layer, this adhesion layer comprises pigment as main component, this pigment is attached to outmost surface, and is formed with the insert layer of one or more coating films on the surface of this rare earth based magnet powder.Can be by for example such oxidation-resistant rare earth based magnet powder of following method manufacturing, the rare earth based magnet powder that has one or more coating retes on its surface is mixed with the Treatment Solution that comprises pigment, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on the outmost surface is carried out drying.As the rare earth based magnet powder that is formed with one or more coating retes on its surface, can mention, for example have coating film that the inorganic phosphate compound makes and go up the rare earth based magnet powder of the anti-oxidant coating film that forms, as described in JP-A-64-11304 and JP-A-7-278602 as its surface.Yet, the coating film that forms on the rare earth based magnet powder surface is not limited to the coating film made by the inorganic phosphate compound, and can be any anti-oxidant coating film known in the art, coating film that for example is made of metal such as aluminium coating film and zinc coating film; Or for example the resin-coating film of polyimides coating film or the multilayer film that constitutes by a plurality of coating films.Therefore, even form the inadequate coating film of non-oxidizability as bottom on the rare earth based magnet powder surface, what form on the rare earth based magnet powder outmost surface is that the adhesion layer of main component can effectively compensate or strengthen non-oxidizability with pigment.
Can be by the method for knowing in this area, by the compound that mixes with resinoid bond according to oxidation-resistant rare earth based magnet powder manufacturing rare earth based bonded magnet of the present invention.As resinoid bond, available have for example epoxy resin of thermosetting resin, phenolic resins, a melamine resin etc.; Thermoplastic resin is polyamide (nylon 66, nylon 6, nylon 12 etc.) for example, polyethylene, polypropylene, polyvinyl chloride, polyester, polyphenylene sulfide etc.; Rubber and estramer; Their modified product, copolymer, and mixture (for example comprises the goods that are dispersed in the thermoplastic resin powder in the thermosetting resin (epoxy resin etc.): referring to " F.Yamashita; Applications Of Rare-Earth Magnets to the Small motor industry; pp.100-111; Proceedings of the seventeenth internationalworkshop; Rare Earth Magnets and Their Applications; August18-22,2002, Newark, Delaware, USA, Edited by G.C.Hadjipanayisand M.J.Bonder, Rinton Press ").With respect to oxidation-resistant rare earth based magnet powder, the combined amount of this resinoid bond in this compound is preferably 3wt% or still less.In obtaining this compound, can add for example coupling agent, lubricant, additives such as curing agent with normally used amount in this field.
Use is according to the preparation of the compound of the rare earth based bonded magnet of oxidation-resistant rare earth based magnet powder of the present invention, be by being shaped to predetermined shape with the compound that is used for rare earth based bonded magnet that aforementioned manner is made, moulding is by pressure forming, injection mo(u)lding, extrusion molding etc.For example, in the situation of working pressure forming method, the pressure forming method of in this area, using always, the forming method that comprises the combination that comprises pressure forming and roll-in (for example, referring to above-mentioned " F.Yamashita; Applications Of Rare-Earth Magnetsto the Small motor industry, pp.100-111, Proceedings of theseventeenth international workshop; Rare Earth Magnets andTheir Applications; August 18-22,2002, Newark; Delaware; USA, Edited by G.C.Hadjipanayis and M.J.Bonder, Rinton Press ").
Carry out pressure forming by compound, the gap is filled thereby the pigment that constitutes the adhesion layer that forms on the magnet powder outmost surface can be clamp-oned in the gap between the magnet powder particle to rare earth based bonded magnet.In this method, can reduce the generation of the hole of bonded permanent magnet surface and inside.Preferably with 0.1GPa to 1GPa, and more preferably carry out the pressure forming of this compound with the pressure of 0.3GPa to 0.6GPa scope.If pressure is lower than 0.1GPa, then hypotony can not obtain the densification of sufficiently high bonded permanent magnet, and this can not effectively reduce the generation of hole.On the other hand, if pressure surpasses 1GPa, it is too high that pressure becomes, and probably can cause breaking so that producing new break surface of magnet powder.Forming temperature usually in room temperature (20 ℃) in 120 ℃ scope, but it depends on the type of resinoid bond.For by reducing between the magnet powder particle or the friction of magnet powder particle and resinoid bond obtains highdensity bonded permanent magnet, perhaps for by improving mobile level and smooth filling of moving the gap between the magnet powder particle that promotes to have the pigment that constitutes the adhesion layer on the magnet powder outmost surface, preferably forming temperature is set in 80 ℃ to 100 ℃ the scope to guarantee pigment.
In using the situation of thermosetting resin, at last the formed body that so obtains is heated and harden so that obtain rare earth based bonded magnet as binding agent.Carry out this heating and sclerosis according to conventional method, for example heating 1 to 5 hour in inert atmosphere (for example nitrogen, argon gas etc.) or vacuum under 140 ℃ to 200 ℃ temperature.
In addition, for further corrosion resistance etc. is provided, can form polytype coating film on rare earth based bonded magnet manufactured according to the present invention, for example the individual layer of cold coating coating film or lamination are electroplated coating film or the like.
Embodiment
Be described in further detail the present invention below by embodiment, still be understood that to the invention is not restricted to this.In the following example, use HDDR magnet powder (average crystalline particle diameter: 0.4 μ m), this magnet powder is to make by the following method: the radio frequency melting is also made ingot casting, the Nd that consists of 12.8at% of this ingot casting, the Dy of 1.0at%, the B of 6.3at%, the Co of 14.8at%, the Ga of 0.5at%, the Zr of 0.09at%, Fe with surplus, in argon gas atmosphere, under 1100 ℃, this ingot casting was annealed 24 hours, oxygen concentration be 0.5% or lower argon gas atmosphere in to pulverize the preparation average particulate diameter be the powder of the pulverizing of 100 μ m, under the pressurized hydrogen atmosphere of 0.15MPa, under 870 ℃, this comminuted powder is carried out the heat of hydrogenation and handled 3 hours, reducing under the pressure in argon gas stream (1kPa) 850 ℃ of coolings 1 hour down after dehydrogenation is handled.
Example I
(embodiment A)
Experiment 1: the production of anti-oxidant HDDR magnet powder
By mixed carbon black in water and soluble epoxide carboxylate and with ammoniacal liquor pH is controlled at 7.2 and prepares aqueous treatment solution (viscosity: 10cP), this aqueous treatment solution comprises 17wt% as the carbon black (average particulate diameter 0.08 μ m) of the inorganic pigment of pigment and the 15wt% soluble epoxide carboxylate as organic dispersion medium.
The 50gHDDR magnet powder is immersed in this Treatment Solution of 50mL, at room temperature mixes then and stirred 3 minutes, use the current air exhauster to reclaim the magnet powder of so handling in 30 seconds by filtration under diminished pressure, then in a vacuum 100 ℃ down heating 1 hour so that dry.The agglomerate that pulverizing obtains thus in mortar is so that obtain the anti-oxidant HDDR magnet powder of black, and this powder surface is attached with and comprises the adhesion layer of carbon black as main component.
To 1g so the anti-oxidant HDDR magnet powder of preparation heat test, this test be included in the air 150 ℃ down heating 100 hours so that the increase ratio of weight after the test that the oxidation of weight causes before measuring with respect to test.The result is as shown in table 1.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
With weight ratio is that 100: 3 the epoxy resin and the mixture of phenolic aldehyde curing agent are dissolved in the methylethylketone so that the preparation resin solution.The mode that should account for anti-oxidant HDDR magnet powder and resin solution total weight 3% with resin solution will be tested the anti-oxidant HDDR magnet powder of producing in 1 and evenly be mixed with this resin solution, allow methylethylketone to volatilize at normal temperatures afterwards so that obtain the compound that is used for rare earth based bonded magnet of powder particle form.The thus obtained compound that is used for rare earth based bonded magnet is carried out pressure forming (100 ℃ of thermoformings under the magnetic field, Hex=0.96MA/m, 0.6GPa), then in argon gas atmosphere 150 ℃ down the formed bodys that so obtain of heating 1 hour so that hardening epoxy resin.Obtain long 12.0mm thus, wide 7.6mm, high 7.4mm, density is 5.9g/cm
3Bonded permanent magnet.
The bonded permanent magnet of making is thus heated test, and this test is included in heated 100 hours under 150 ℃ in the air so that the weight increase ratio with respect to weight before testing that oxidation causes after the measurement test.In addition, after the magnetization of this bonded permanent magnet, carry out respectively in air 100 ℃ down heating 500 hours and in air 150 ℃ down 100 hours heating of heating test so that the magnetic flux degeneration factor (irreversible demagnetization coefficient) of magnetic flux before testing with respect to each after measuring test.Then, in air and 150 ℃ down 100 hours bonded permanent magnets of heating magnetize once more in case after measuring magnetization once more with respect to the magnetic flux degeneration factor (demagnetizing factor forever) of the preceding magnetic flux of test.The result is shown in Fig. 1 and 2 and table 2.
(Embodiment B)
Experiment 1: the production of anti-oxidant HDDR magnet powder
Prepare aqueous treatment solution (viscosity: 15cP), this aqueous treatment solution comprises 17wt% and is used as the organic pigment indanthrene (average particulate diameter 0.06 μ m) of pigment and the 15wt% soluble epoxide carboxylate as organic dispersion medium by in water, mixing indanthrene and soluble epoxide carboxylate and pH being controlled at 7.2 with ammoniacal liquor.
Thus, similar to the experiment 1 in the embodiment A, use above-mentioned Treatment Solution to make the anti-oxidant HDDR magnet powder of indigo, this powder surface is attached with and comprises the adhesion layer of indanthrene as main component.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 1.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result is shown in Fig. 1 and 2 and table 2.
(Embodiment C)
Experiment 1: the production of anti-oxidant HDDR magnet powder
By mixed copper phthalocyanine in water and soluble epoxide carboxylate and with ammoniacal liquor pH is controlled at 7.2 and prepares aqueous treatment solution (viscosity: 17cP), this aqueous treatment solution comprises 17wt% as the organic pigment copper phthalocyanine (average particulate diameter 0.06 μ m) of pigment and the 15wt% soluble epoxide carboxylate as organic dispersion medium.
Thus, similar to the experiment 1 in the embodiment A, use above-mentioned Treatment Solution to make the anti-oxidant HDDR magnet powder of indigo, this powder surface is attached with and comprises the adhesion layer of copper phthalocyanine as main component.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 1.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result is shown in Fig. 1 and 2 and table 2.
(embodiment D)
Experiment 1: the production of anti-oxidant HDDR magnet powder
Prepare Ethanol Treatment solution (viscosity: 30cP), this solution comprises 17wt% and is used as the organic pigment indanthrene (average particulate diameter 0.06 μ m) of pigment and the 15wt% acrylate copolymer based high molecular decentralized medium as organic dispersion medium by in ethanol, mixing indanthrene and acrylate copolymer based high molecular decentralized medium.
Thus, similar to the experiment 1 in the embodiment A, use above-mentioned Treatment Solution to make the anti-oxidant HDDR magnet powder of indigo, this powder surface is attached with and comprises the adhesion layer of indanthrene as main component.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 1.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result is shown in Fig. 1 and Fig. 2 and table 2.
(embodiment E)
Experiment 1: the production of anti-oxidant HDDR magnet powder
(viscosity: 28cP), this solution comprises 17wt% as the inorganic pigment carbon black (average particulate diameter 0.08 μ m) of pigment and the 15wt% acrylate copolymer based high molecular decentralized medium as organic dispersion medium to prepare Ethanol Treatment solution by mixed carbon black in ethanol and acrylate copolymer based high molecular decentralized medium.
Thus, similar to the experiment 1 in the embodiment A, use above-mentioned Treatment Solution to make the anti-oxidant HDDR magnet powder of black, this powder surface is attached with and comprises the adhesion layer of carbon black as main component.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 1.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result is shown in Fig. 1 and 2 and table 2.
(comparative examples)
To not being similar to the heating test of the experiment 1 of embodiment A, and measure the increase ratio of weight after the test that causes with respect to the weight oxidation before the test through any surface-treated HDDR magnet powder.The result is as shown in table 1.In addition, utilize the method identical to make bonded permanent magnet, only be to use without any surface-treated HDDR magnet powder of mistake with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result is shown in Fig. 1 and 2 and table 2.
Table 1
| Anti-oxidant HDDR magnet powder | Weight increases ratio (%) |
| Embodiment A | 0.05 |
| Embodiment B | 0.05 |
| Embodiment C | 0.06 |
| Embodiment D | 0.04 |
| Embodiment E | 0.04 |
| Comparative examples (untreated powder) | 0.30 |
Table 2
| Bonded permanent magnet | Weight increases ratio (%) | 100 ℃ * 500 hours magnetic flux degeneration factors (%) | 150 ℃ * 100 hours magnetic flux degeneration factors (%) | Permanent demagnetizing factor (%) (the magnetic flux degeneration factor that oxidation causes) after magnetizing again |
| Embodiment A | 0.10 | -11.0 | -29.7 | -4.4 |
| Embodiment B | 0.09 | -9.8 | -29.0 | -4.0 |
| Embodiment C | 0.11 | -11.2 | -30.4 | -4.6 |
| Embodiment D | 0.09 | -12.0 | -28.2 | -4.2 |
| Embodiment E | 0.09 | -10.3 | -28.7 | -4.5 |
| Comparative examples | 0.32 | -13.8 | -36.6 | -7.9 |
(n＝3)
Can be clear from table 1, with do not carry out any surface-treated HDDR magnet powder and compare, the anti-oxidant HDDR magnet powder that embodiment A is made in each to embodiment E all has the weight that much lower oxidation causes increases ratio, and therefore above-mentioned magnet powder has excellent non-oxidizability.
In addition, can clearly be seen that, compare that embodiment A to the bonded permanent magnet of embodiment E can produce caused weight increase ratio of less oxidation and magnetic flux degeneration factor with the bonded permanent magnet of comparative examples from Fig. 1 and 2 and table 2.Can explain this excellent properties of embodiment A by the following fact: use the HDDR magnet powder of having given the superior oxidation resistance energy that they are shaped to reservation shape to the bonded permanent magnet of embodiment E, and in the compound preparation process, this compound is being shaped in the pressure forming process of reservation shape, perhaps all suppress the generation of the blemish that factor causes because magnet powder breaks etc. any period after moulding, can effectively prevent the generation of oxidation thus.In addition, use the surface of the above-mentioned bonded permanent magnet of sem observation, can find with the bonding granules of pigments of the resinoid bond of bonded permanent magnet with its hole sealing.It is believed that this effect also helps the superior oxidation resistance of bonded permanent magnet.Estimate A: the number in the hole that exists on the bonded permanent magnet surface
To three kinds of bonded permanent magnets, i.e. embodiment A, each bonded permanent magnet of Embodiment B and comparative examples, along short transverse will long 12.0mm and the plane of high 7.4mm be divided into 7 equal zones, along pressure direction promptly from top to bottom with the zone number of dividing.Use the surface in each zone of electron microscope observation.Add up that diameter is 20 μ m or bigger hole in each zone, and calculate every 1mm
2Number of perforations.The result as shown in Figure 3.Can be clear from Fig. 3, the number of perforations of the bonded permanent magnet of embodiment A and Embodiment B is much smaller than the number of perforations of the bonded permanent magnet of comparative examples.
Estimate B: the relation between the weight rate of water-immersed duration and bonded permanent magnet
To three kinds of bonded permanent magnets, i.e. embodiment A, each bonded permanent magnet of Embodiment B and comparative examples has been studied the relation between water-immersed duration and the weight rate.The result as shown in Figure 4.Can be clear from Fig. 4, the weight rate of the bonded permanent magnet of embodiment A and Embodiment B is much smaller than the weight rate of the bonded permanent magnet of comparative examples.In addition, by carrying out weight rate that hole sealing handles the bonded permanent magnet that obtains for the bonded permanent magnet of comparative examples between the weight rate of the bonded permanent magnet of the weight rate of the bonded permanent magnet of embodiment A and Embodiment B and comparative examples.These results show, by carry out the bonded permanent magnet that hole sealing processing obtains for the bonded permanent magnet of comparative examples its lip-deep hole is effectively handled, but the hole of this magnet inside are fully handled; On the other hand, this shows, for the bonded permanent magnet of embodiment A and Embodiment B, has not only reduced the generation of hole on the magnet surface but also has reduced the generation of magnet internal void.
Annotate: the hole sealing processing method of the bonded permanent magnet of comparative examples
The bonded permanent magnet of comparative examples is immersed in the aqueous treatment solution for preparing in the step 1 of embodiment A, after under pressure remains on decompression in the vacuum tank of 0.5Pa, being penetrated into Treatment Solution in the hole, when recovering normal pressure, bonded permanent magnet is taken out from container and water washes its surface so that remove excessive Treatment Solution of adhering to, subsequently in air 120 ℃ dry 20 minutes down.
Example II
(embodiment A)
Experiment 1: the production of anti-oxidant HDDR magnet powder
The 100gHDDR magnet powder is immersed 300mL to be contained in the ethanolic solution of 0.09mol/L phosphoric acid, after at room temperature mixing and stirring 3 minutes, use the current air exhauster to pass through filtration under diminished pressure and reclaimed the magnet powder of so handling in 30 seconds, heated 30 minutes down so that dry at 120 ℃ in a vacuum then.On the surface of HDDR magnet powder, formed the coating film that constitutes by the inorganic phosphate compound thus.
By mixed copper phthalocyanine in water and soluble epoxide carboxylate and with ammoniacal liquor pH is controlled at 7.2 and prepares aqueous treatment solution (viscosity: 17cP), this aqueous treatment solution comprises 17wt% as the organic pigment copper phthalocyanine (average particulate diameter 0.06 μ m) of pigment and the 15wt% soluble epoxide carboxylate as organic dispersion medium.
The coating film HDDR magnet powder that is formed with inorganic phosphate compound formation on the 50g surface is immersed in this Treatment Solution of 50mL, after at room temperature mixing and stirring 3 minutes, use the current air exhauster to pass through filtration under diminished pressure and reclaimed the magnet powder of so handling in 30 seconds, heated 1 hour down so that dry at 100 ℃ in a vacuum then.In mortar, pulverize the agglomerate that obtains thus so that obtain the anti-oxidant HDDR magnet powder of indigo, this powder has and comprises the adhesion layer of copper phthalocyanine as main component, and this adhesion layer is attached on the outmost surface that is inserted with the coating film that the inorganic phosphate compound constitutes therebetween.
To 1g so the anti-oxidant HDDR magnet powder of preparation heat test, this test be included in the air 150 ℃ down heating 100 hours so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
With weight ratio is that 100: 3 the epoxy resin and the mixture of phenolic aldehyde curing agent are dissolved in the methylethylketone so that the preparation resin solution.The mode that should account for anti-oxidant HDDR magnet powder and resin solution total weight 3% with resin solution will be tested the anti-oxidant HDDR magnet powder of producing in 1 and evenly be mixed with this resin solution, allow methylethylketone to volatilize at normal temperatures afterwards so that obtain the compound of the rare earth based bonded magnet of powder particle form.The thus obtained compound that is used for rare earth based bonded magnet is carried out pressure forming (100 ℃ of thermoformings under the magnetic field, Hex=0.96MA/m, 0.6GPa), then in argon gas atmosphere 150 ℃ down the formed bodys that so obtain of heating 1 hour so that hardening epoxy resin.Obtain long 12.0mm thus, wide 7.6mm, high 7.4mm, density is 5.9g/cm
3Bonded permanent magnet.
The bonded permanent magnet of making is thus heated test, and this test is included in heated 100 hours under 150 ℃ in the air so that the weight increase ratio with respect to weight before testing that oxidation causes after the measurement test.In addition, after the magnetization of this bonded permanent magnet, carry out respectively in air 100 ℃ down heating 500 hours and in air 150 ℃ down 100 hours heating of heating test so that the magnetic flux degeneration factor (irreversible demagnetization coefficient) of magnetic flux before testing with respect to each after measuring test.Then, in air and 150 ℃ down 100 hours bonded permanent magnets of heating magnetize once more in case after measuring magnetization once more with respect to the magnetic flux degeneration factor (demagnetizing factor forever) of the preceding magnetic flux of test.The result is shown in Fig. 5 and Fig. 6 and table 4.
(Embodiment B)
Experiment 1: the production of anti-oxidant HDDR magnet powder
Prepare Ethanol Treatment solution (viscosity: 30cP), this solution comprises 17wt% and is used as the organic pigment indanthrene (average particulate diameter 0.06 μ m) of pigment and the 15wt% acrylate copolymer based high molecular decentralized medium as organic dispersion medium by in ethanol, mixing indanthrene and acrylate copolymer based high molecular decentralized medium.
Thus, similar to the experiment 1 in the embodiment A, use above-mentioned Treatment Solution to make the anti-oxidant HDDR magnet powder of indigo, this powder has and comprises the adhesion layer of indanthrene as main component, and this adhesion layer is attached on the outmost surface that is inserted with the coating film that the inorganic phosphate compound constitutes therebetween.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(Embodiment C)
Experiment 1: the production of anti-oxidant HDDR magnet powder
The 100gHDDR magnet powder is immersed 300mL to be contained in the aqueous solution of 0.14mol/L sodium dihydrogen phosphate, after at room temperature mixing and stirring 3 minutes, use the current air exhauster to pass through filtration under diminished pressure and reclaimed the magnet powder of so handling in 30 seconds, heated 30 minutes down so that dry at 120 ℃ in a vacuum then.On the surface of HDDR magnet powder, formed the coating film that constitutes by the inorganic phosphate compound thus.
Thus, similar to the experiment 1 in the embodiment A, experiment 1 used same treatment solution in use and the embodiment A is made the anti-oxidant HDDR magnet powder of indigo, this powder has and comprises the adhesion layer of copper phthalocyanine as main component, and this adhesion layer is attached on the outmost surface that is inserted with the coating film that the inorganic phosphate compound constitutes therebetween.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(embodiment D)
Experiment 1: the production of anti-oxidant HDDR magnet powder
Similar with the experiment 1 in the Embodiment C, experiment 1 used same treatment solution comes the anti-oxidant HDDR magnet powder of production indigo in use and the Embodiment B, this powder has and comprises the adhesion layer of indanthrene as main component, and this adhesion layer is attached on the outmost surface that is inserted with the coating film that the inorganic phosphate compound constitutes therebetween.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(embodiment E)
Experiment 1: the production of anti-oxidant HDDR magnet powder
On the surface of HDDR magnet powder, form the thick Al coating film of 0.3 μ m by vacuum deposition method well known in the art.
Thus, similar to the experiment 1 in the embodiment A, experiment 1 used same treatment solution in use and the embodiment A is made the anti-oxidant HDDR magnet powder of indigo, this powder has and comprises the adhesion layer of copper phthalocyanine as main component, and this adhesion layer is attached on the outmost surface that is inserted with the Al coating film therebetween.Then, the anti-oxidant HDDR magnet powder of producing thus is similar to the heating test of experiment 1 of embodiment A so that the increase ratio of weight after measuring the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.
Experiment 2: the manufacturing of bonded permanent magnet and character thereof
Utilize the method identical to make bonded permanent magnet, test the anti-oxidant HDDR magnet powder of gained in 1 above only being to use with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(comparative examples 1)
To not being similar to the heating test of the experiment 1 of embodiment A, and measure the increase ratio of weight after the test that causes with respect to the weight oxidation before the test through any surface-treated HDDR magnet powder.The result is as shown in table 3.In addition, utilize the method identical to make bonded permanent magnet, only be to use without any surface-treated HDDR magnet powder of mistake with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(comparative examples 2)
The HDDR magnet powder that has the coating film that the inorganic phosphate compound constitutes on its surface according to the method manufacturing of embodiment A experiment 1 is similar to the heating test of the experiment 1 of embodiment A, and measures the increase ratio of weight after the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.In addition, utilize the method manufacturing bonded permanent magnet identical, only be to use this HDDR magnet powder with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out testing 2 identical tests with embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(comparative examples 3)
The HDDR magnet powder that has the coating film that the inorganic phosphate compound constitutes on its surface according to the method manufacturing of the experiment 1 of Embodiment C is similar to the heating test of the experiment 1 of embodiment A, and measures the increase ratio of weight after the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.In addition, utilize the method manufacturing bonded permanent magnet identical, only be to use this HDDR magnet powder with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
(comparative examples 4)
The HDDR magnet powder that has A l coating film on its surface according to the method manufacturing of the experiment 1 of embodiment E is similar to the heating test of the experiment 1 of embodiment A, and measures the increase ratio of weight after the test that causes with respect to the weight oxidation before the test.The result is as shown in table 3.In addition, utilize the method manufacturing bonded permanent magnet identical, only be to use this HDDR magnet powder with the experiment 2 of embodiment A.The bonded permanent magnet that makes is thus carried out the test identical with the experiment 2 of embodiment A.The result as Fig. 5 and 6 and table 4 shown in.
Table 1
| Anti-oxidant HDDR magnet powder | Weight increases ratio (%) |
| Comparative examples 1 (untreated powder) | 0.30 |
| Comparative examples 2 | 0.01 |
| Comparative examples 3 | 0.01 |
| Comparative examples 4 | 0.01 |
| Embodiment A | 0.01 |
| Embodiment B | 0.01 |
| Embodiment C | 0.01 |
| Embodiment D | 0.01 |
| Embodiment E | 0.01 |
Table 2
| Bonded permanent magnet | Weight increases ratio (%) | 100 ℃ * 500 hours magnetic flux degeneration factors (%) | 150 ℃ * 100 hours magnetic flux degeneration factors (%) | Permanent demagnetizing factor (%) (the magnetic flux degeneration factor that oxidation causes) after magnetizing again |
| Comparative examples 1 | 0.32 | -13.8 | -36.6 | -7.9 |
| Comparative examples 2 | 0.34 | -13.0 | -39.1 | -9.0 |
| Comparative examples 3 | 0.34 | -14.5 | -39.4 | -9.9 |
| Comparative examples 4 | 0.33 | -14.1 | -35.0 | -7.7 |
| Embodiment A | 0.08 | -10.7 | -29.5 | -4.3 |
| Embodiment B | 0.06 | -12.6 | -27.9 | -3.8 |
| Embodiment C | 0.06 | -9.9 | -27.9 | -3.7 |
| Embodiment D | 0.05 | -11.3 | -27.3 | -3.8 |
| Embodiment E | 0.07 | -11.5 | -28.9 | -4.0 |
(n＝3)
Can be clear from table 3, with do not carry out any surface-treated HDDR magnet powder in the comparative examples 1 and compare, the anti-oxidant HDDR magnet powder that embodiment A is made to the embodiment E, and comparative examples 2 surface of making to the comparative examples 4 coats the HDDR magnet powder and all has the weight that much lower oxidation causes and increase ratio, and therefore above-mentioned magnet powder has excellent non-oxidizability.
Yet, from Fig. 5 and 6 and table 4 can be clear, comparative examples 2 to the bonded permanent magnet of comparative examples 4 since the Different Weight that oxidation shows to increase the bonded permanent magnet of ratio and magnetic flux degeneration factor and comparative examples 1 suitable.On the other hand, compare with the bonded permanent magnet of comparative examples 1, embodiment A to the bonded permanent magnet of embodiment E increases ratio and magnetic flux degeneration factor because oxidation produces less weight.Can explain this excellent properties of embodiment A by the following fact: use the HDDR magnet powder of having given the superior oxidation resistance energy that they are shaped to reservation shape to the bonded permanent magnet of embodiment E, and be different from the bonded permanent magnet of comparative examples 2 to comparative examples 4, in the compound preparation process, this compound is being shaped in the pressure forming process of reservation shape, perhaps all suppress the generation of the blemish that factor causes because magnet powder breaks etc. any period after moulding, can effectively prevent the generation of oxidation thus.In addition, use the surface of the above-mentioned bonded permanent magnet of sem observation, can find to seal by lip-deep hole with the bonding granules of pigments of the resinoid bond of bonded permanent magnet.It is believed that this effect also helps the superior oxidation resistance of bonded permanent magnet.
Industrial usability
The present invention has the industrial usability of following aspect: the method that is applicable to make the oxidation-resistant rare earth based magnet powder of rare earth based bonded magnet and makes this magnet powder is provided, this bonded permanent magnet not only has excellent non-oxidizability but also has excellent magnetic property, with the compound that is provided for rare earth based bonded magnet, the method that rare earth based bonded magnet is provided and makes this magnet.
Claims (19)
1. oxidation-resistant rare earth based magnet powder, it is characterized in that this powder has in its surface comprises the adhesion layer of pigment as main component, and the average particulate diameter of described pigment is in the scope of 0.01 μ m to 0.5 μ m, and wherein said particle diameter is meant the main shaft diameter.
2. the oxidation-resistant rare earth based magnet powder of claim 1 is characterized in that described pigment is inorganic pigment.
3. the oxidation-resistant rare earth based magnet powder of claim 2 is characterized in that described inorganic pigment is a carbon black.
4. the oxidation-resistant rare earth based magnet powder of claim 1 is characterized in that described pigment is organic pigment.
5. the oxidation-resistant rare earth based magnet powder of claim 4 is characterized in that described organic pigment is indanthrene base pigment or phthalocyanine base pigment.
6. the oxidation-resistant rare earth based magnet powder of claim 1 is characterized in that the average particulate diameter of described rare earth based magnet powder is not more than 200 μ m.
7. the oxidation-resistant rare earth based magnet powder of claim 6 is characterized in that described rare earth based magnet powder is the HDDR magnet powder.
8. the oxidation-resistant rare earth based magnet powder of claim 1 is characterized in that this powder has attached to the adhesion layer on the outmost surface, and have the intermediate layer of the one or more coating films that form on the surface of described rare earth based magnet powder.
9. the oxidation-resistant rare earth based magnet powder of claim 8, it is characterized in that being formed on the lip-deep described coating film of described rare earth based magnet powder is the coating film that is made of the inorganic phosphate compound.
10. the oxidation-resistant rare earth based magnet powder of claim 8, it is characterized in that being formed on the lip-deep described coating film of described rare earth based magnet powder is the coating film that is made of metal.
11. the manufacture method of oxidation-resistant rare earth based magnet powder, this powder has in its surface and comprises the adhesion layer of pigment as main component, the method is characterized in that it comprises mixes rare earth based magnet powder with the Treatment Solution that comprises pigment, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is carried out drying, the average particulate diameter of wherein said pigment is in the scope of 0.01 μ m to 0.5 μ m, and wherein said particle diameter is meant the main shaft diameter.
12. the manufacture method of claim 11, it is characterized in that this method comprises mixes rare earth based magnet powder with the Treatment Solution that comprises pigment, obtain by the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on its surface is filtered then.
13. the manufacture method of claim 11 is characterized in that pigment accounts for described 5wt% to 3 3wt% that comprises the Treatment Solution of pigment.
14. the manufacture method of claim 11 is characterized in that the described Treatment Solution that comprises pigment comprises organic dispersion medium.
15. the manufacture method of oxidation-resistant rare earth based magnet powder, this powder has attached on the outmost surface and comprise the adhesion layer of pigment as main component, and the intermediate layer that has the one or more coating films that on the surface of this rare earth based magnet powder, form, the method is characterized in that it comprises mixes rare earth based magnet powder with the Treatment Solution that contains pigment, wherein this powder has one or more layers coating film that forms in its surface, then the rare earth based magnet powder that is attached with the Treatment Solution that contains pigment on the outermost surface is carried out drying, the average particulate diameter of wherein said pigment is in the scope of 0.01 μ m to 0.5 μ m, and wherein said particle diameter is meant the main shaft diameter.
16. be used for the compound of rare earth based bonded magnet, it is characterized in that it comprises the oxidation-resistant rare earth based magnet powder and the resinoid bond of claim 1.
17. rare earth based bonded magnet is characterized in that having used the compound that is used for rare earth based bonded magnet of claim 16 and it is shaped to predetermined shape.
18. the manufacture method of rare earth based bonded magnet, it is characterized in that it comprises the compound that is used for rare earth based bonded magnet that uses claim 16 and with the technology that comprises at least one pressure forming step it is shaped to predetermined shape, can heat and harden this molded part if necessary subsequently.
19. the manufacture method of claim 18 is characterized in that carrying out described pressure forming by the pressure of 0.1GPa to 1GPa.
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| CN113488330B (en) * | 2021-07-15 | 2023-05-05 | 江苏蓝沛新材料科技有限公司 | Preparation method of functional magnetic slurry and magnetic device |
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| JPS6190401A (en) * | 1984-10-09 | 1986-05-08 | Shin Etsu Chem Co Ltd | Composition of plastic magnet |
| JP2001068314A (en) * | 1999-08-26 | 2001-03-16 | Sony Corp | Magnetic powder and magnetic recording medium |
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| JPS6190401A (en) * | 1984-10-09 | 1986-05-08 | Shin Etsu Chem Co Ltd | Composition of plastic magnet |
| JP2001068314A (en) * | 1999-08-26 | 2001-03-16 | Sony Corp | Magnetic powder and magnetic recording medium |
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