JP2005187929A - Rare-earth magnet and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rare-earth magnet which has a protective layer with superior characteristics on the surface and thereby shows high corrosion resistance, and to provide a manufacturing method therefor. <P>SOLUTION: The rare-earth magnet 1 comprises a magnet body 2 containing a rare-earth element and a protective layer 4 formed on the surface. The protective layer 4 contains a compound in which an organic structural unit and an inorganic structural unit are covalently bonded. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rare earth magnet and a method for producing the same, and more particularly to a rare earth magnet having a protective layer on the surface and a method for producing the same.

  Conventionally, rare earth magnets are known as high performance permanent magnets. These are not only used for household appliances such as conventional air conditioners and refrigerators, but are also being applied to drive motors such as industrial machines, robots, fuel cell vehicles and hybrid cars. It is expected that energy saving can be realized. Among such rare earth magnets, R—Fe—B (R is a rare earth element) type magnet has attracted attention because it has particularly high magnetic properties. As such R—Fe—B rare earth magnets, for example, those described in Patent Document 1 and Patent Document 2 below are known.

  These R—Fe—B rare earth magnets are high-performance magnets exhibiting a high energy product exceeding 25 MGOe. However, since it contains rare earth elements and iron as the main components of the magnet, it is very easily oxidized and has low temperature resistance. For this reason, these magnets tend to have low corrosion resistance, and it is difficult to avoid deterioration of magnetic characteristics over time due to long-term use.

  In recent years, attempts have been made to form a protective layer on the surface of a magnet body for the purpose of improving the corrosion resistance of such R—Fe—B rare earth magnets. For example, Patent Document 3 listed below describes a rare earth magnet in which an oxidation-resistant metal film is formed on the surface of a magnet body by plating, thereby improving the oxidation resistance of the magnet.

Patent Document 4 listed below describes a rare earth magnet in which a resin film is formed on the surface of a magnet body, thereby improving the oxidation resistance of the magnet. Further, Patent Document 5 below describes a rare earth magnet in which a dense coating made of a metal oxide is formed on the surface of a magnet body by a sol-gel method, thereby improving the corrosion resistance and alkali resistance of the magnet. Yes.
JP 59-46008 A JP-A-60-9852 JP-A-60-54406 JP-A-60-63901 JP 2001-76914 A

  Since the rare earth magnet according to the above prior art has various protective layers on the surface of the magnet body, it has higher corrosion resistance than when the magnet body is used alone. However, these rare earth magnets have insufficient corrosion resistance due to insufficient properties of the protective layer itself, and are still practical for applications where severe conditions such as high temperature conditions are imposed. It was scarce.

  For example, the metal film formed by plating described in Patent Document 3 tends to have a pinhole. Thus, if even a slight pinhole or the like is present in the protective layer, the corrosion resistance of the entire magnet is remarkably reduced, for example, the magnet body is corroded by a salt spray test.

  In addition, since the protective layer in the rare earth magnet described in Patent Document 4 is made of resin, the moisture permeability resistance is not perfect, and therefore, external moisture may slightly permeate the protective layer. It was. When external moisture permeates the protective layer in this way, the moisture comes into contact with the magnet body and corrodes the contact area, or moisture enters between the protective layer and the magnet body to peel off the protective layer. There is a risk of inducing problems such as promoting Furthermore, the protective layer composed of the resin in this way often has insufficient heat resistance, and a magnet provided with such a protective layer has been difficult to use under high temperature conditions.

  Furthermore, in the rare earth magnet described in Patent Document 5, the sol solution for film formation is heated at the time of forming the protective layer, thereby causing solvent evaporation, polymerization or thermal decomposition reaction. In the process, the applied sol liquid tends to cause large volume shrinkage. If it becomes like this, the protective layer formed by this volume shrinkage will have a stress, and, thereby, it will become easy to produce a crack in a protective layer. This tendency is particularly great when a thick protective layer is to be formed or when the magnet surface has irregularities. Thus, when a crack arises in a protective layer, the corrosion resistance of a rare earth magnet will become extremely low like the case of the pinhole mentioned above.

  The present invention has been made in view of the circumstances of these prior arts, and provides a rare earth magnet capable of exhibiting high corrosion resistance by providing a protective layer having excellent characteristics on the surface, and a method for producing the same. For the purpose.

  The inventors of the present invention have made extensive studies to achieve the above object, and when a so-called organic-inorganic hybrid material using a combination of an organic material and an inorganic material is applied to a protective layer for a magnet, It is possible to form a protective layer having the above characteristics at the same time, and such a protective layer has superior characteristics as compared to a protective layer formed by using an organic material or an inorganic material alone as in the above-described conventional technology. I found that I have.

  Further, when a further detailed study was made on such a protective layer, it was found that the organic layer and the inorganic material were simply mixed with each other as in the conventionally known organic-inorganic hybrid material. It has been discovered that phase separation between components and inorganic components may occur. For this reason, in the protective layer which consists of these mixtures, it turned out that a uniform characteristic cannot be exhibited over the whole protective layer.

  Based on these findings, the present inventors applied a compound containing a compound having a predetermined interaction between the two components as an organic-inorganic hybrid material combining an organic component and an inorganic component to the protective layer. The present inventors have found that a rare earth magnet having extremely excellent corrosion resistance can be obtained.

  That is, the rare earth magnet of the present invention includes a magnet body containing a rare earth element and a protective layer formed on the surface of the magnet body, and the protective layer is made of an organic polymer. And a structural unit composed of an inorganic polymer (hereinafter abbreviated as “inorganic structural unit”) is covalently bonded to a structural unit (hereinafter, abbreviated as “organic structural unit”). It is characterized by that.

  The compound contained in the protective layer in the rare earth magnet is a so-called organic-inorganic hybrid compound containing an organic structural unit and an inorganic structural unit in the molecule. This compound has a structure in which both structural units are bonded by a covalent bond. For this reason, in the protective layer containing such a compound, the phase separation between the organic component and the inorganic component, which has occurred in the conventional organic-inorganic hybrid material, is rare, and both structural units are uniformly dispersed in the film. It will be in the state. Such a protective layer has high density and can exhibit uniform characteristics over the entire film, so that it is extremely reliable as a protective layer for a magnet.

  Moreover, since the compound contained in the protective layer of the rare earth magnet contains both an organic structural unit and an inorganic structural unit as described above, the protective layer is formed when an organic material or an inorganic material is used alone. Each has the characteristics obtained. Examples of characteristics obtained by such a protective layer include the following.

  That is, first, in the protective layer, the compound in the protective layer has a flexible organic structural unit in the molecule. For this reason, a protective layer containing such a compound can relieve stress in a flexible organic structural unit even if stress that shrinks the volume occurs in processes such as solvent evaporation and polymerization during film formation. Can do. The protective layer formed in this way is extremely less likely to generate pinholes and cracks, which has been a problem when forming a protective layer made of only an inorganic material.

  In addition, since the above compound has an inorganic structural unit in the molecule, the protective layer containing this compound is significantly superior in heat resistance and moisture resistance compared to a protective layer formed only from an organic material. It becomes. As a result, the rare earth magnet having such a protective layer has characteristics that can withstand use under high temperature conditions, and corrosion of the magnet body due to moisture that has permeated the protective layer is significantly reduced. .

  Thus, the protective layer having the above-described configuration has excellent corrosion resistance as compared with a conventional protective layer formed by using either an organic material or an inorganic material alone. In addition to such effects, the protective layer has a property of high adhesion to the rare earth magnet. Although this cause is not necessarily clear, it is considered to be based on the following reasons. That is, the rare earth element contained in the magnet body has a characteristic of high reactivity with oxygen. The organic-inorganic hybrid compound in the protective layer often has an oxygen atom in the molecule. Therefore, when a protective layer containing an organic-inorganic hybrid compound is applied as a protective layer for a magnet body containing a rare earth magnet, the rare earth element and the protective layer are chemically bonded via oxygen, thereby ensuring adhesion between the two. Will improve. However, the action is not limited to these.

  In the rare earth magnet, the inorganic structural unit constituting the protective layer preferably has a main chain formed by alternately bonding metal atoms and oxygen atoms. In this case, the covalent bond between the organic structural unit and the inorganic structural unit is more preferably generated between the carbon atom in the former and the metal atom in the latter. By doing so, a strong covalent bond is formed between the two structural units, which makes it possible to further reduce the phase separation that occurs in the protective layer.

  More specifically, the metal atom in the inorganic structural unit is preferably at least one element selected from the group consisting of Si, Al, Ti, Zr, Ta, Mo, Nb and B. Of these, Si is preferable. When the metal atom is any of these elements, the inorganic structural unit has high stability, and as a result, the corrosion resistance of the protective layer is further improved.

As the inorganic structural unit having Si as a metal atom, a structural unit obtained from a compound represented by the following formula (1) and / or a hydrolysis product thereof is particularly preferable. By having such an inorganic structural unit, the corrosion resistance of the protective layer is further improved.
[Chemical 1]
R ¹ _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. ^{When a} plurality of ¹ or R ² are present, each may be the same or different.)

  Moreover, it is preferable that an organic structural unit contains the structural unit obtained from a vinyl group containing monomer or an epoxy group containing monomer. Furthermore, it is more preferable that the organic structural unit having these configurations has a weight average molecular weight of 2000 or more.

  Furthermore, the compound contained in the protective layer of the rare earth magnet of the present invention has more favorable characteristics when the blending ratio of each component is within a predetermined range. That is, it is preferable that the content of the organic structural unit is 10 to 80% by mass with respect to the total amount of the organic structural unit and the inorganic structural unit.

  A method for producing a rare earth magnet according to the present invention is a method for simply producing the rare earth magnet of the present invention, and is composed of a structural unit comprising an organic structural unit and having a functional group condensable at a terminal or a side chain. A coating liquid to be a protective layer by mixing an organic polymer with an inorganic monomer in which a condensable functional group is bonded to a metal element and / or an inorganic polymer precursor containing a condensation product of this inorganic monomer. A coating liquid preparation step to prepare, a coating step of coating this coating solution on the outer surface of the magnet body containing the rare earth element, and a protective layer forming step of forming a protective layer from the coating solution. It is characterized by containing a compound in which an organic structural unit and an inorganic structural unit are bonded by a covalent bond. Here, the protective layer forming step includes a case where the protective layer is formed simultaneously with the application to the magnet body.

  In the rare earth magnet manufacturing method, the protective layer is formed by a so-called wet method in which a coating solution to be a protective layer is applied to the magnet body. According to such a method, it is possible to form a film having a uniform thickness under mild conditions without using a complicated apparatus or the like.

  More specifically, in the coating liquid preparation step, after performing the above-described mixing, the condensable functional group in the organic polymer and the condensable functional group in the inorganic polymer precursor are condensed and the inorganic polymer precursor is condensed. It is preferable to prepare a coating solution by polycondensing the bodies with functional groups capable of condensing each other.

  In this case, the coating liquid contains a compound in which an organic structural unit and an inorganic structural unit are bonded by a covalent bond. When such a coating solution is used, both structural units are already in a state of being bonded by a covalent bond, and therefore phase separation hardly occurs in the subsequent steps. As a result, a protective layer in which these structural units are dispersed very well is formed.

  On the other hand, the reaction between the organic polymer and the inorganic polymer precursor and the condensation of the inorganic polymer precursors described above may be performed in the coating step and / or the protective layer forming step, not in the coating liquid preparation step. That is, in the coating step and / or protective layer forming step, the condensable functional group in the organic polymer and the condensable functional group in the inorganic polymer precursor can be condensed and the inorganic polymer precursors can be condensed with each other. The above compounds can also be produced by polycondensation with various functional groups.

  The condensable functional group in the organic polymer and inorganic monomer used in the production method described above is preferably a hydroxyl group and / or a hydrolyzable group. These functional groups tend to easily cause a condensation reaction. By having such a functional group, condensation between the organic polymer and the inorganic monomer and / or the condensation product thereof, and condensation between the inorganic monomers can be further performed. It tends to occur.

  Further, as the organic polymer used in the above method, it is preferable to use a polymer in which a metal atom is bonded to a terminal or side chain carbon atom and a condensable functional group is bonded to this metal atom. As the metal atom in the organic polymer, Si is suitable.

  Further, as such an organic polymer, it is preferable to use those containing a structural unit obtained from a vinyl group-containing monomer or an epoxy group-containing monomer, and an organic polymer having these structures has a weight average molecular weight of 2000 or more. It is particularly preferable to use one having

Furthermore, it is preferable to use an inorganic monomer having at least one element selected from the group consisting of Si, Al, Ti, Zr, Ta, Mo, Nb and B as a metal atom. Specifically, a compound represented by the following formula (1) and / or a hydrolysis product thereof can be exemplified.
[Chemical 2]
R ¹ _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. ^{When a} plurality of ¹ or R ² are present, each may be the same or different.)

  According to the present invention, there is provided a rare earth magnet having a protective layer on the surface which has both the characteristics of both an organic material and an inorganic material, and hardly causes phase separation between the organic component and the inorganic component. It becomes possible. Such rare earth magnets have extremely excellent corrosion resistance and are suitable as permanent magnets used in applications that are used under high temperature conditions, such as drive motors for fuel cell vehicles and hybrid cars.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, an embodiment of the rare earth magnet of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a rare earth magnet according to a preferred embodiment. FIG. 2 is a cross-sectional view taken along line II-II of the rare earth magnet shown in FIG. A rare earth magnet 1 shown in FIGS. 1 and 2 has a configuration in which a protective layer 4 is formed on the surface of a magnet body 2. Hereinafter, the components constituting the protective layer 4 and the magnet body 2 will be described.

  First, the components of the protective layer 4 will be described. The protective layer 4 has an organic structural unit and an inorganic structural unit, and a compound in which these structures are bonded by a covalent bond (such a compound is hereinafter referred to as “organic-inorganic hybrid compound”). It is mainly composed.

  The organic structural unit in this organic-inorganic hybrid compound refers to a polymer structure having a main chain composed of bonds between carbon atoms. The main chain may have an atom other than carbon, for example, an oxygen atom, a nitrogen atom, or the like in a part thereof.

  Such an organic structural unit is not particularly limited as long as it is a polymer structure usually formed from an organic compound. For example, there are no restrictions on the polymerization of organic compounds formed by various polymerization reactions such as addition polymerization, polycondensation, and polyaddition. An example is a combined structure. Of these, vinyl polymer structures formed from vinyl group-containing monomers and epoxy polymer structures obtained from epoxy group-containing monomers are preferred.

  In the organic-inorganic hybrid compound, the above-described organic structural unit preferably has a weight average molecular weight of 2000 or more, more preferably 2,000 to 500,000, and further preferably 4,000 to 100,000. Here, the “weight average molecular weight” is defined as a value obtained by measurement by gel permeation chromatography and conversion by a calibration curve using standard polystyrene. When the weight average molecular weight is 2000 or more, the stress relaxation property of the protective layer is improved, and cracks and the like tend not to occur in the protective layer. On the other hand, when it exceeds 500,000, the viscosity of the coating solution described later increases, making it difficult to apply, and forming the protective layer 4 may be difficult.

  The inorganic structural unit in the organic-inorganic hybrid compound is a polymer structure having a main chain composed of elements other than carbon atoms. Further, the main chain contains a metal atom as an element other than carbon, and has a structure in which metal atoms and oxygen atoms are alternately bonded in a preferred case.

  The metal atom contained in the main chain of such an inorganic structural unit is preferably at least one element selected from the group consisting of Si, Al, Ti, Zr, Ta, Mo, Nb and B. Among them, a polymer having a main chain containing a —Si—O— bond, in particular, a polysiloxane structure can be synthesized relatively easily, and polymers having various structures can be formed. The polymer structure constituting the main chain is particularly preferable.

As the polymer having a main chain containing a —Si—O— bond, a polymer structure obtained by condensation or cocondensation of a compound represented by the following formula (1) and / or a hydrolysis product thereof is particularly preferable. It is. Since the inorganic structural unit comprising such a polymer structure has excellent stress relaxation properties, the protective layer containing the organic-inorganic hybrid compound containing this structure is less prone to cracks and the like. In the following formulae, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. In the case where R ¹ or R ² there are a plurality, it may be the same or different each.
[Chemical formula 3]
R ¹ _m Si (OR ² ) _4-m (1)

  The covalent bond in the organic-inorganic hybrid compound having these structural units is mainly a bond between a carbon atom in the organic structural unit and a metal atom in the inorganic structural unit. This covalent bond may be formed by directly bonding the carbon atom and the metal atom, or may be formed by bonding the carbon atom and the metal atom via other elements. In the latter case, only a covalent bond is formed between the carbon atom and the metal element.

  The covalent bond is -C-M- (C is a carbon atom in an organic structural unit, M is a metal atom in an inorganic structural unit), or -C-X-M- (X is other than a carbon atom and a metal atom) Is a bond represented by: In the latter case, the bond represented by —C—O—M— is particularly preferable because it is particularly easy to form.

  Among these, as the covalent bond, a bond represented by -C-M-, in which a carbon atom in an organic structural unit and a metal atom in an inorganic structural unit are directly bonded, is particularly preferable. For example, the bond represented by —C—O—M— described above has characteristics close to ionicity, and thus is susceptible to depolymerization with water in the presence of an acid or base, or under conditions such as high temperature. It has properties. On the other hand, since the bond represented by the above -C-M- has a large binding energy, it is difficult to cause such decomposition. For this reason, the organic-inorganic hybrid compound having a covalent bond represented by -C-M- has a characteristic that the phase separation caused by the cleavage of the covalent bond is extremely rare even when exposed to high temperature conditions. It will have.

  In the organic-inorganic hybrid compound having such a configuration, the content of the organic structural unit is preferably 10 to 80% by mass, more preferably 20 to 70, with respect to the total amount of the organic structural unit and the inorganic structural unit, and The content of the inorganic structural unit is preferably 90 to 20% by mass, and more preferably 80 to 30%. When the content of the organic structural unit is less than 10% by mass (that is, when the content of the inorganic structural unit exceeds 90% by mass), the stress relaxation property of the protective layer obtained tends to be small. On the other hand, when the content of the organic structural unit exceeds 80% by mass (that is, when the content of the inorganic structural unit is less than 20% by mass), the heat resistance and moisture resistance of the resulting protective layer tend to decrease. is there.

In addition, as long as the protective layer 4 has the organic-inorganic hybrid compound mentioned above as a main component, it may contain another substance. Other substances to be included in the protective layer 4 include fine metal powders such as Al, Mg, Ca, Zn, Si, and Mn, and fine metal oxide powders such as SiO ₂ , TiO ₂ , ZrO ₂ , and Al ₂ O _3. Examples thereof include resin components such as acrylic resin and epoxy resin, and clay minerals such as montmorillonite.

  Next, the constituent material of the magnet body 2 in the rare earth magnet 1 will be described. The magnet body 2 is a permanent magnet containing a rare earth element. In this case, the rare earth element refers to an element belonging to the third period of the long-period type periodic table and an element belonging to the lanthanoid. Examples of such rare earth elements include yttrium (Y), lanthanum (La), cerium ( Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium ( Tm), ytterbium (Yb), lutetium (Lu) and the like.

  Examples of the constituent material of the magnet body 2 include those containing the rare earth element and the transition element in combination. In this case, as the rare earth element, at least one element selected from the group consisting of Nd, Dy, Pr and Tb is preferable, and these elements include La, Sm, Ce, Gd, Er, Eu, Tm, Yb and Y. More preferably, it further contains at least one element selected from the group consisting of:

  More specifically, examples of the constituent material of the magnet body 2 include those having an R—Fe—B (R is a rare earth element) type or R—Co type structure. In the material having the former structure, R is preferably Nd, and in the material having the latter structure, R is preferably Sm.

  Especially, as a constituent material of the magnet body 2 in the rare earth magnet 1, a material having an R—Fe—B structure is preferable. Such a material has a main phase having a substantially tetragonal crystal structure, and a rare earth-rich phase having a high rare earth element content in the grain boundary portion of the main phase, and a boron atom content ratio. Has a high boron-rich phase. These rare earth-rich phase and boron-rich phase are nonmagnetic phases that do not have magnetism, and such a nonmagnetic phase is usually contained in an amount of 0.5 to 50% by volume in the magnet constituting material. Moreover, the particle size of the main phase is usually about 1 to 100 μm.

  In the constituent material of the magnet body 2 having such a configuration, the rare earth element content is preferably 8 to 40 atomic%. When the rare earth element content is less than 8 atomic%, the crystal structure of the main phase becomes almost the same as that of α-iron, and the coercive force (iHc) tends to decrease. On the other hand, if it exceeds 40 atomic%, a rare earth-rich phase is excessively formed, and the residual magnetic flux density (Br) tends to be small.

  The Fe content is preferably 42 to 90 atomic%. When the Fe content is less than 42 atomic%, Br decreases, and when it exceeds 90 atomic%, iHc tends to decrease. Furthermore, the B content is preferably 2 to 28 atomic%. When the content of B is less than 2 atomic%, a rhombohedral structure is likely to be formed, and this tends to reduce iHc, and when it exceeds 28 atomic%, a boron-rich phase is excessively formed. Br tends to be small.

  In the constituent materials described above, a part of Fe in R—Fe—B may be substituted with Co. Thus, if a part of Fe is replaced by Co, the temperature characteristics can be improved without deteriorating the magnetic characteristics. In this case, it is desirable that the amount of substitution of Co not be larger than the content of Fe. When the Co content exceeds the Fe content, the magnetic properties of the magnet body 2 tend to be reduced.

  A part of B in the constituent material may be substituted with an element such as C, P, S or Cu. By replacing a part of B in this way, the magnet body can be easily manufactured and the manufacturing cost can be reduced. At this time, the substitution amount of these elements is desirably an amount that does not substantially affect the magnetic properties, and is preferably 4 atomic% or less with respect to the total amount of constituent atoms.

  Further, from the viewpoint of improving iHc and reducing manufacturing costs, in addition to the above-described structure, Al, Ti, V, Cr, Mn, Bi, Nb, Ta, Mo, W, Sb, Ge, Sn, Zr, Ni , Si, Ga, Cu, Hf and other elements may be added. These addition amounts are also preferably in a range that does not affect the magnetic properties, and are preferably 10 atomic% or less with respect to the total amount of constituent atoms. In addition, O, N, C, Ca, etc. are conceivable as components inevitably mixed, and these may be contained in an amount of about 3 atomic% or less with respect to the total amount of constituent atoms.

The magnet body 2 having such a configuration can be manufactured by powder metallurgy. In this method, first, an alloy having a desired composition is produced by a known alloy production process such as a casting method or a strip casting method. Next, this alloy was pulverized to a particle size of 10 to 100 μm using a coarse pulverizer such as a jaw crusher, brown mill, stamp mill, etc. The particle size is 5 to 5 μm. The powder thus obtained is preferably molded at a pressure of 0.5 to ⁵ t / cm ² in a magnetic field having a magnetic field strength of 600 kA / m or more.

  Thereafter, the obtained compact is preferably sintered in an inert gas atmosphere or under vacuum at 1000 to 1200 ° C. for 0.5 to 10 hours and then rapidly cooled. Further, the sintered body is subjected to heat treatment at 500 to 900 ° C. for 1 to 5 hours in an inert gas atmosphere or vacuum, and then the sintered body is processed into a desired shape to obtain the magnet body 2. .

  The rare earth magnet 1 of a preferred embodiment has a structure in which a protective layer 4 is provided on the surface of a magnet body 2. In the rare earth magnet 1, the thickness of the protective layer 4 is preferably 0.1 to 100 μm, and more preferably 5 to 50 μm. When the thickness is less than 0.1 μm, it is extremely difficult to sufficiently cover the magnet surface, and the formed film tends to easily peel off. On the other hand, when the thickness exceeds 100 μm, the protective layer tends to crack, and the reliability as the protective layer tends to be lowered. In this case, the thickness of the protective layer 4 refers to the average thickness of the protective layer 4 formed on the surface of the magnet body 2.

  Further, the rare earth magnet 1 may include one or more layers other than the protective layer 4 on the surface of the magnet body 2. For example, an inorganic oxide layer or a metal layer may be provided as a base layer of the protective layer 4, and a resin coat layer or the like may be further provided on the surface of the protective layer 4.

  Next, an embodiment of a method for producing the rare earth magnet 1 configured as described above will be described. The manufacturing method of the rare earth magnet 1 includes a step of preparing a coating solution capable of forming the protective layer 4 (coating solution preparation step), a step of applying a coating solution on the surface of the magnet body 2 (coating step), It has the process (protective layer formation process) which forms the protective layer 4 from a coating liquid.

  In the production of the rare earth magnet 1, first, in the coating liquid preparation step, it is possible to condense as an organic polymer, a compound comprising an organic structural unit having a functional group condensable at the terminal or side chain, and an inorganic polymer precursor. An inorganic monomer in which a functional group is bonded to a metal element and / or a condensation product of this inorganic monomer is prepared. Then, these are mixed in the state melt | dissolved or disperse | distributed to the predetermined | prescribed solvent.

  Here, the condensable functional group represents a functional group capable of causing a condensation reaction such as hydrolysis condensation between the functional groups. Examples of such functional groups include hydrolyzable groups such as hydroxyl groups, alkoxy groups, and epoxy groups. Among these, the case where one has a hydroxyl group and the other has an alkoxy group, or the case where both have a hydroxyl group, is the combination in which the condensation reaction is most likely to occur. In the organic polymer, it is more preferable that a metal element is bonded to a terminal or side chain carbon atom, and a functional group capable of condensation is bonded to the metal element. In the present invention, the condensable functional group includes a functional group that changes to a condensable functional group after a predetermined reaction. For example, if both have an alkoxy group and one of them is hydrolyzed to form a hydroxyl group, both can be condensed, and both alkoxy groups are included in the condensable functional group Will be.

  The organic polymer used in the coating solution preparation step can be obtained by the following method. That is, for example, a method of reacting an organic polymer compound with a monomer that should be a condensable functional group, or a method of polymerizing a vinyl compound into which a condensable functional group has been introduced and another vinyl compound. .

  In the former method for producing an organic polymer, the organic polymer compound and the monomer need to have a functional group capable of reacting with each other. For example, when an organic polymer compound has a carbon-carbon double bond or an epoxy group, and a monomer has a metal-hydrogen bond or an amino group, these functional groups can react with each other. It becomes. Preferable examples include a method of reacting an organic polymer compound having a carbon-carbon double bond with a hydrosilane compound having a condensable functional group. Such a reaction causes a reaction between the double bond of the organic polymer compound and the metal-hydrogen bond in the hydrosilane compound, thereby obtaining an organic polymer into which a silyl group having a condensable functional group is introduced.

  Moreover, in the latter method for producing an organic polymer, it has both a vinyl-based compound having a carbon-carbon double bond, a condensable functional group, and a carbon-carbon double bond. An organic polymer having a condensable functional group introduced can be obtained by copolymerizing any combination of vinyl compounds. From the viewpoint of efficiently producing such copolymerization, it is preferable to use a compound having a (meth) acryl group as the vinyl compound. In addition, a (meth) acryl group shall show an acryl group or a methacryl group.

  The organic polymer formed by these methods preferably has a weight average molecular weight of 2000 or more, more preferably 2000 to 500,000, and still more preferably 4000 to 100,000.

On the other hand, the inorganic monomer in the inorganic polymer precursor is a monomer in which a condensable functional group is bonded to a metal atom. Examples of the condensable functional group include a hydroxyl group or a hydrolyzable group. As the hydrolyzable group, an alkoxy group that generates a hydroxyl group by hydrolysis is preferable. Examples of such an inorganic monomer include a monomer made of Si to which a hydroxyl group or an alkoxy group is bonded. More specifically, examples of the inorganic monomer include compounds represented by the following general formula (1). In the following formulae, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2.
[Chemical formula 4]
R ¹ _m Si (OR ² ) _4-m (1)

Moreover, the condensation product of the inorganic monomer which is an inorganic polymer precursor is an oligomer or polymer obtained by polycondensation of the above-mentioned inorganic monomer by heating or the like. The condensation product is preferably the former oligomer. For example, when the inorganic monomer is a compound represented by the above formula (1), an oligomer or polymer having a group represented by —OR ² which is a functional group capable of condensing at the terminal is obtained. The group represented by —OR ² at the terminal contributes to the reaction with the condensable functional group in the organic polymer, as will be described later.

  In the production of the rare earth magnet 1, a coating step for coating the coating solution on the surface of the magnet body 2 is performed following the coating solution preparation step described above. The coating method is not particularly limited, and a known method can be appropriately selected and used. Examples thereof include a dip coating method, a spray coating method, and a spin coating method.

  At this time, the application of the coating solution takes into consideration the solvent volatilization or volume shrinkage after the application so that the thickness of the protective layer 4 to be obtained is a desired value (in the preferred case, 0.1 to 100 μm). It is preferable to make adjustments. For example, when application is performed by the dip coating method, the thickness of the application liquid to be applied can be adjusted by immersing the magnet body 2 in the application liquid and appropriately setting the pulling speed and time.

  In addition, from the viewpoint of performing such coating easily and improving the adhesion of the protective layer 4 to be formed, the surface of the magnet body 2 is subjected to a predetermined treatment before the coating process is performed. Is desirable. As this predetermined treatment, for example, after the surface of the magnet body 2 is smoothed by barrel polishing or the like, the surface of the element body is degreased and further cleaned with an acid solution or washed with water, etc. Thus, the magnet body 2 having the following can be obtained.

  And after implementing the said application | coating process, the protective layer 4 is formed from the apply | coated coating liquid in the protective layer formation process. In the protective layer forming step, for example, the magnet body 2 coated with the coating liquid is heated, or the magnet body 2 is left in the atmosphere to volatilize the solvent in the coating liquid. The protective layer 4 is formed from the coating solution.

  In the method for producing the rare earth magnet 1 according to the present invention, in at least one of the coating liquid preparation step, the coating step, and the protective layer forming step, the condensable functional group in the organic polymer and the inorganic polymer precursor are used. While condensing with the functional group which can be condensed, inorganic polymer precursors are polycondensed with the mutual condensable functional group.

  In the condensation reaction, for example, when the inorganic polymer precursor includes the inorganic monomer, condensation occurs between the condensable functional group in the organic polymer and the condensable functional group in the inorganic monomer, and both are covalently bonded. Are combined. Further, along with this condensation, condensation occurs between the condensable functional group in the inorganic monomer bonded to the organic polymer and the condensable functional group in the other inorganic monomer, and the reaction between the inorganic monomers occurs repeatedly, resulting in an inorganic reaction. A structural unit is formed. An organic-inorganic hybrid compound is produced by these two reactions.

  When the inorganic polymer precursor contains a condensation product of an inorganic monomer, the condensable functional group in the condensation product and the condensable functional group in the organic polymer react. Further, when the condensation product is in a state where a further condensation reaction can occur, a polycondensation reaction between the condensation products occurs together with the above reaction. These reactions produce an organic-inorganic hybrid compound. In addition, when an inorganic polymer precursor contains both an inorganic monomer and its condensation product, both above-mentioned reaction advances.

  When the inorganic polymer precursor is condensed in the coating liquid preparation step, these reactions are performed by, for example, mixing the organic polymer and the inorganic polymer precursor and then adding water to the mixture. Can be generated.

  In addition, when the condensation reaction is caused in the coating solution preparation step, the reaction solution may be heated to accelerate the reaction. Furthermore, when the inorganic monomer contains Si, it is more preferable to add a catalyst because the polycondensation reaction tends to progress slowly. Examples of the catalyst in this case include an acid, a base, an organometallic compound, and the like, and a base or an organometallic salt is preferable.

  Thus, when implementing the said condensation in a coating liquid preparation process, it is preferable to stir etc. the said liquid mixture on the conditions of 20-150 degreeC and 10 minutes-48 hours. Under such conditions, the condensation reaction tends to occur efficiently.

  When the inorganic polymer precursor is condensed in the protective layer forming step, the magnet body 2 with the coating liquid applied is heated or left in the atmosphere for a predetermined time. For example, when tetrabutoxyzirconium or the like is used as the inorganic monomer, the condensation reaction between the inorganic monomers is promoted by moisture in the air by leaving it in the air.

  In order to efficiently cause the condensation in the protective layer forming step, the magnet body 2 coated with the coating liquid is preferably treated at room temperature to 300 ° C. for 1 minute to 24 hours. When these temperatures are low or the treatment time is short, a sufficient polymerization reaction of the inorganic monomer is difficult to occur, and the inorganic structural unit is not sufficiently formed, which tends to lower the heat resistance of the protective layer. On the other hand, when the treatment temperature exceeds 300 ° C., the organic structural unit is decomposed and the flexibility of the protective layer tends to be lowered.

  Furthermore, in the coating step, the above condensation can be caused at the same time as the coating liquid is applied to the magnet body 2. In this case, in order to further promote the condensation reaction, the magnet element body 2 may be applied while being heated.

  The above-mentioned condensation between the organic polymer and the inorganic polymer precursor and the polycondensation between the inorganic polymer precursors may occur in any of the coating liquid preparation step, the coating step, and the protective layer formation step. Preferably, it is generated at least in the protective layer forming step. Thereby, the hydroxyl group etc. which accompany a polycondensation reaction react with the active functional group which exists in the magnet element body 2 surface, and the adhesiveness to the magnet element body 2 of the protective layer 4 further improves.

  Then, in the case where the production method of the present invention is particularly suitable, after a part of the condensation reaction is caused in the coating liquid preparation step (that is, the condensation does not proceed completely), the coating is applied in the protective layer forming step. Condensation by the inorganic polymer precursor remaining in the liquid preparation step is further caused. By doing so, a large amount of the organic-inorganic hybrid compound is contained at the coating liquid stage, and the protective layer 4 in which the organic structural unit and the inorganic structural unit are uniformly dispersed is obtained. In addition, since the condensation occurs in the protective layer forming step, the adhesion of the protective layer 4 to the magnet body 2 is improved.

By such a reaction between the organic polymer and the inorganic polymer precursor, an organic-inorganic hybrid compound in which the organic structural unit and the inorganic structural unit are bonded by a covalent bond is generated. Hereinafter, specific examples of the covalent bond in the organic-inorganic hybrid compound will be shown. For example, as the organic polymer, a hydroxyl group that is a condensable functional group is directly bonded to an organic structural unit (C ¹ —OH: C ¹ represents a carbon atom in the organic structural unit), and the above hydroxyl group is used as an inorganic monomer. When an alkoxy group that can be condensed with a metal element (M ¹ -OR: M ¹ represents a metal element) is used, the hydroxyl group of the organic polymer and the alkoxy group of the inorganic monomer are condensed. Produces a bond having the structure -C ¹ -OM ^1- . And an inorganic structural unit is formed by the polycondensation of an inorganic monomer after that. Accordingly, in the organic-inorganic hybrid compound obtained, the -C 1 ^-O-M 1 ^- bond represented by is, corresponds to covalent coupling the organic structural unit and an inorganic structural unit.

On the other hand, in the preferred case, as described above, the condensable functional group in the organic polymer is in a state of being bonded to the organic structural unit via the metal element. An organic polymer having such a structure and having an alkoxy group as a condensable functional group (C ² -M ² -OR: C ² is a carbon atom in the organic structural unit, M ² is an alkoxy group When an inorganic polymer having an alkoxy group that is a condensable functional group bonded to a metal element (M ³ -OR: M ³ represents a metal element) is used as the inorganic polymer A bond structure represented by —C ² —M ² —OM ³ — is generated by a hydrolysis-condensation reaction occurring between the two alkoxy groups. And an inorganic structural unit is formed by the polycondensation of inorganic monomers after that.

In this case, as represented by the above-described bonding structure, M ² that is a metal element that the organic polymer originally had is incorporated as a constituent element of the inorganic structural unit after the condensation. Therefore, in such a case, in the obtained organic-inorganic hybrid compound, the bond represented by —C ² —M ² — that was initially present in the organic polymer is a covalent bond that binds the organic structural unit and the inorganic structural unit. It becomes a bond.

  In the protective layer 4 containing the organic-inorganic hybrid compound thus formed, as described above, the carbon atom in the organic structural unit and the metal element in the inorganic structural unit are bonded by a covalent bond. For this reason, in the protective layer 4, the phase separation of an organic component and an inorganic component which is generated when a conventional organic-inorganic hybrid material in which only an organic material and an inorganic material are mixed is used hardly occurs. Become. If it becomes like this, in the protective layer 4 formed, both structural units will come to exist uniformly and exhibit high performance as a protective layer for magnets.

In particular, when the covalent bond is represented by —C ² —M ² — in the above example, the organic structural unit and the inorganic structural unit are directly bonded by the carbon bond and the metal element that each has. Since both structural units are in a more firmly bonded state, the reliability of the protective layer 4 is further increased.

  According to the rare earth magnet 1 configured as described above, the following effects can be obtained. That is, the rare earth magnet 1 has the protective layer 4 including the organic-inorganic hybrid compound having a structure in which an organic structural unit and an inorganic structural unit are bonded by a covalent bond on the surface of the magnet body 2 as described above. Yes. In such a protective layer, the organic component and the inorganic component are uniformly dispersed due to the fact that both structural units are bonded by a covalent bond.

  For this reason, the protective layer 4 has the characteristics obtained using an organic material and an inorganic material. For example, it has excellent moisture resistance and heat resistance compared to a protective layer obtained only from an organic material, and excellent stress relaxation properties compared to a protective layer obtained only from an inorganic material. doing.

  Furthermore, the rare earth element contained in the magnet body 2 has a strong reactivity with oxygen atoms even under relatively low temperature conditions. Moreover, the organic-inorganic hybrid compound in the protective layer 4 formed by the manufacturing method described above has an oxygen atom such as a hydroxyl group in its structure. For this reason, the rare earth element in the magnet body 2 and the oxygen atoms in the protective layer 4 have a strong tendency to cause chemical bonds. That is, the magnet body 2 and the protective layer 4 are in a state of being bonded by chemical bonding. As a result, in the rare earth magnet 1, the adhesion between the magnet body 2 and the protective layer 4 is significantly improved.

  More specifically, the magnet body 2 often has a hydroxyl group derived from the constituent material of the magnet on the surface thereof. In addition, since the organic-inorganic hybrid compound has a functional group capable of condensing the organic polymer or inorganic polymer precursor as a raw material, the organic-inorganic hybrid compound formed by condensation of these is also present in the molecule. It has a plurality of condensable functional groups. If it becomes like this, dehydration condensation will arise between the functional group which can be condensed in an organic inorganic hybrid compound, and the hydroxyl group of the magnet surface, and, thereby, the adhesiveness with respect to the magnet base body 2 of the protective layer 4 will become remarkably favorable.

  Thus, since the protective layer 4 has extremely excellent corrosion resistance, the rare earth magnet 1 provided with the protective layer 4 has magnetic characteristics even when used under conditions exposed to high temperature and high humidity. It will be less likely to cause degradation of. For this reason, such a rare earth magnet 1 is extremely suitable as a permanent magnet used for a drive motor of a fuel cell vehicle or a hybrid car.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples.

(Example 1)
A sintered body having a composition represented by 14Nd-1Dy-7B-78Fe (numbers are atomic ratio) prepared by powder metallurgy is subjected to heat treatment under conditions of 600 ° C. for 2 hours in an argon atmosphere. The sintered body was cut into a size of 56 mm × 40 mm × thickness 8 mm to obtain a magnet body. The magnet body was washed with an alkaline degreasing solution and further treated with a nitric acid solution to activate the surface of the magnet body, and then the surface was repeatedly washed with water.

  Separately, 28 g of methyl methacrylate, 6 g of 2-ethylhexyl methacrylate and 6 g of γ-methacryloxypropyltrimethoxysilane were added to 40 g of 2-propanol and mixed, and then 2,2′- 1.6 g of azoisobutyronitrile was added and reacted at 80 ° C. for 6 hours to prepare a solution of an acrylic resin having a silyl group. In addition, when the molecular weight of this acrylic resin was measured by gel permeation chromatography, the weight average molecular weight was about 10,000 (converted by a calibration curve using standard polystyrene).

  Next, 80 g of methyltrimethoxysilane, 15 g of 2-propanol, and 17.5 g of 0.1% ammonia water were further added to 40 g of this acrylic resin solution, and reacted at 50 ° C. for 5 hours, whereby acrylic resin and methyl A coating solution containing an organic-inorganic hybrid compound formed by combining with a polymer of trimethoxysilane was obtained.

  Furthermore, after this coating solution is applied to the surface of the magnet body described above by the dip coating method, the surface of the magnet body is protected from an organic-inorganic hybrid compound by heating at 150 ° C. for 20 minutes. A layer was formed to obtain a rare earth magnet.

<Characteristic evaluation>
Using the obtained rare earth magnet, the thickness of the protective layer was measured, the surface was observed, and the corrosion resistance was evaluated by an acceleration test. That is, first, the average thickness of the protective layer was measured by cutting the rare earth magnet at the central portion in the width direction (in the depth direction in FIG. 1) and observing the cut surface with an electron microscope. As a result, the thickness of the protective layer was 30 μm. Next, when the surface of the rare earth magnet was observed with an electron microscope, it was found that no defects such as cracks were formed on the surface of the protective layer of the magnet.

  Next, an accelerated corrosion resistance test was performed in which the rare earth magnet was treated at 80 ° C. and 90% RH. As a result, even after 300 hours from the start of the test, no rust was observed in the magnet body, and it was found that the magnet body was not corroded.

(Example 2)
A rare earth magnet was produced in the same manner as in Example 1 except that the coating solution was adjusted by the method described below. That is, first, 28 g of methyl methacrylate, 6 g of 2-ethylhexyl methacrylate and 6 g of γ-methacryloxypropyltrimethoxysilane were added to 60 g of 2-propanol and mixed, and then 2,2′-azoisobutyrate was added to this solution. 2.4 g of nitrile was added and reacted at 80 ° C. for 6 hours to prepare an acrylic resin solution having a silyl group. The acrylic resin had a weight average molecular weight of about 4000. Next, 80 g of a tetrabutoxyzirconium solution (80% n-butanol solution) and 16.7 g of acetylacetone were added to 50 g of this acrylic resin solution to obtain a coating solution.

  Using the obtained rare earth magnet, the thickness of the protective layer was measured, the surface was observed, and the corrosion resistance was evaluated by an acceleration test in the same manner as in Example 1. As a result, the thickness of the protective layer was 15 μm, and no defects such as cracks were observed on the surface of the protective layer in the magnet. Furthermore, in the accelerated test, no rust was observed in the magnet body even after 300 hours had elapsed from the start of the test.

(Comparative Example 1)
A rare earth magnet was produced in the same manner as in Example 1 except that the coating solution was prepared by the method described below. That is, after adding 68 g of methyltrimethoxysilane to 50 g of 2-propanol and mixing, 15 g of 0.1% ammonia water was added to this solution and reacted at 80 ° C. for 6 hours to prepare a coating solution containing an acrylic resin. did.

  Using the obtained rare earth magnet, the thickness of the protective layer was measured, the surface was observed, and the corrosion resistance was evaluated by an acceleration test in the same manner as in Example 1. As a result, the thickness of the protective layer was 10 μm, and it was confirmed that cracks were generated on the surface of the protective layer in the rare earth magnet. Further, in the accelerated test, rust was generated in the magnet body after 300 hours had elapsed from the start of the test.

(Comparative Example 2)
A rare earth magnet was produced in the same manner as in Example 1 except that the coating solution was prepared by the method described below. That is, first, 28 g of methyl methacrylate and 12 g of 2-ethylhexyl methacrylate were added to 40 g of 2-propanol and mixed, and then 1.6 g of 2,2′-azoisobutyronitrile was further added to this solution. The solution was reacted at 6 ° C. for 6 hours to prepare a solution containing an acrylic resin. Separately, 160 g of methyltrimethoxysilane was added to 30 g of 2-propanol and dissolved by stirring, and 35 g of 0.1% aqueous ammonia was added to this solution and reacted at 50 ° C. for 5 hours. A solution containing a polymer of trimethoxysilane was produced. Then, the coating liquid containing the mixture of an acrylic resin and the said polymer was prepared by mixing these solutions.

  Using the obtained rare earth magnet, the thickness of the protective layer was measured, the surface was observed, and the corrosion resistance was evaluated by an acceleration test in the same manner as in Example 1. As a result, the thickness of the protective layer was 30 μm, and a sea-island structure having a size of about 1 μm due to phase separation was confirmed on the surface of the protective layer. Further, in the accelerated test, rust was generated in the magnet body after 300 hours had elapsed from the start of the test.

It is a perspective view which shows the rare earth magnet which concerns on suitable embodiment. It is sectional drawing along the II-II line of the rare earth magnet shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rare earth magnet, 2 ... Magnet base body, 4 ... Protective layer.

Claims (19)

A magnet body containing a rare earth element, and a protective layer formed on the surface of the magnet body,
The protective layer is
A rare earth magnet comprising a compound in which a structural unit composed of an organic polymer and a structural unit composed of an inorganic polymer are bonded by a covalent bond.   2. The rare earth magnet according to claim 1, wherein the structural unit made of the inorganic polymer is a structural unit including a main chain formed by alternately bonding metal atoms and oxygen atoms.   The rare earth magnet according to claim 1, wherein the covalent bond is a covalent bond between a carbon atom in the structural unit made of the organic polymer and a metal atom in the structural unit made of the inorganic polymer.   4. The metal atom according to claim 1, wherein the metal atom is at least one element selected from the group consisting of Si, Al, Ti, Zr, Ta, Mo, Nb, and B. 5. Rare earth magnet.   The rare earth magnet according to claim 1, wherein the metal atom is Si. The structural unit comprising the inorganic polymer has the following formula (1):
[Chemical 1]
R ¹ _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. ^{When a} plurality of ¹ or R ² are present, each may be the same or different.)
The rare earth magnet according to any one of claims 1 to 5, comprising a structural unit obtained from a compound represented by formula (1) and / or a hydrolysis product thereof.   The rare earth magnet according to any one of claims 1 to 6, wherein the structural unit comprising the organic polymer includes a structural unit obtained from a vinyl group-containing monomer or an epoxy group-containing monomer.   The rare earth magnet according to any one of claims 1 to 7, wherein a weight average molecular weight of the structural unit composed of the organic polymer is 2000 or more.   The content of the structural unit composed of the organic polymer is 10 to 80% by mass with respect to the total amount of the structural unit composed of the organic polymer and the structural unit composed of the inorganic polymer. The rare earth magnet as described in any one of -8. An organic polymer composed of an organic polymer composed of a structural unit having a functional group condensable at the terminal or side chain, an inorganic monomer in which the condensable functional group is bonded to a metal atom, and / or condensation of the inorganic monomer A coating liquid preparation step for preparing a coating liquid to be a protective layer through mixing with an inorganic polymer precursor containing a product,
A coating step of coating the coating liquid on the surface of a magnet body containing a rare earth element;
A protective layer forming step of forming the protective layer from the coating solution,
The protective layer is
A method for producing a rare earth magnet comprising a compound in which a structural unit composed of an organic polymer and a structural unit composed of an inorganic polymer are bonded by a covalent bond.   In the coating liquid preparation step, after the mixing, the condensable functional group in the organic polymer and the condensable functional group in the inorganic polymer precursor are condensed, and the inorganic polymer precursor The method for producing a rare earth magnet according to claim 10, wherein the coating liquid is prepared by polycondensing each other with the condensable functional groups.   In the coating step and / or the protective layer forming step, the condensable functional group in the organic polymer and the condensable functional group in the inorganic polymer precursor are condensed and the inorganic polymer precursors are The method for producing a rare earth magnet according to claim 10, wherein polycondensation is performed using the mutually condensable functional groups.   The method for producing a rare earth magnet according to any one of claims 10 to 12, wherein the condensable functional group in the organic polymer and the inorganic monomer is a hydroxyl group and / or a hydrolyzable group.   14. The organic polymer according to claim 10, wherein a metal atom is bonded to a terminal or side chain carbon atom, and the condensable functional group is bonded to the metal atom. The manufacturing method of the rare earth magnet as described in any one.   The method for producing a rare earth magnet according to claim 14, wherein the metal atom in the organic polymer is Si.   The method for producing a magnet according to any one of claims 10 to 15, wherein the organic polymer includes a structural unit obtained from a vinyl group-containing monomer or an epoxy group-containing monomer.   The method for producing a magnet according to any one of claims 10 to 16, wherein an organic polymer having a weight average molecular weight of 2000 or more is used.   18. The metal atom in the inorganic monomer is at least one element selected from the group consisting of Si, Al, Ti, Zr, Ta, Mo, Nb and B. 18. A method for producing the rare earth magnet according to 1. As said inorganic monomer, following formula (1);
[Chemical 2]
R ¹ _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents an organic group having 1 to 8 carbon atoms, R ² represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 4 carbon atoms, and m is 1 or 2. ^{When a} plurality of ¹ or R ² are present, each may be the same or different.)
A method for producing a rare earth magnet according to any one of claims 10 to 18, wherein a compound represented by the formula (1) and / or a hydrolysis product thereof is used.

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