JP2002164206A - Anisotropic bonded magnet, rotating machine, and magnet roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new high-performance anisotropic bonded magnet, which has maximum energy product (BH)max equivalent to or higher than that of the conventional anisotropic ferrite bonded magnet or anisotropic sintered ferrite magnet, and in addition, is improved in magnetization and heat resistance. SOLUTION: This anisotropic bonded magnet is composed substantially of R-T-N-based magnetic powder the main component expressed by RαT100-α-βNβ (where R and T respectively denote at least one kind of rare-earth element, including Y and Fe or Fe and Co and α and β respectively denote atomic % meeting 5<=α<=20 and 5<=β<=30), sintered ferrite magnetic powder, substantially having a magnetoplumbite type crystal structure and a mean particle diameter of 10-1,000 μm, and a binder which binds the two kinds of magnetic powder to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide range of magnet-applied product fields, for example, various rotating machines for automobiles or electric equipment, magnet rolls used for developing rolls in electrophotography and electrostatic recording, etc. Useful for loudspeakers, buzzers, magnets for attracting or generating magnetic fields, etc.
The present invention relates to a novel high-performance anisotropic bonded magnet having (BH) max and further improved magnetizability or heat resistance. The present invention also relates to a high-performance rotating machine and a magnet roll configured using the high-performance anisotropic bonded magnet.

[0002]

2. Description of the Related Art In recent years, poor magnetization and a measure of heat resistance, for example, a permeance coefficient: Pc = 1 to 2 (Pc = Bd / (−
Hd)), where Bd and Hd are the B and H values at the operating point on the BH demagnetization curve. The Sm ₂ Fe ₁₇ N _x (x = 2 to 6) system can be used as a substitute for a rare-earth bonded magnet using magnetic powder having a main phase of Nd ₂ Fe ₁₄ B intermetallic compound having a large irreversible demagnetization rate evaluated in (1). Practical use of bonded magnets (Patent No. 2703281 and the like) has been promoted. However, Sm ₂ Fe ₁₇ N _x system bonded magnets miniaturization of recent magnet applied products, no heat resistance and magnetizability is sufficient to severe needs for high performance, improvements are desired.

[0003] International Publication WO98 / 38654 discloses that at least one element selected from Sr, Ba, Ca and Pb, which contains a ferrite having a hexagonal structure as a main phase, and which always contains Sr. A, R is at least one element selected from rare earth elements (including Y) and Bi and always contains La, and is Co or C
When o and Zn are M, the total composition ratio of the metal elements of A, R, Fe and M is A: 1 to 13 at%, R: 0.05 to 10 at%, based on the total metal element amount, Fe:
A bond magnet using ferrite particles containing an oxide magnetic material having a composition of 80 to 95 atomic% and M: 0.1 to 5 atomic% is described. As a specific example, the final composition is Sr _0.7 La _0.3 Fe _12-7 Co _0.3 O ₁₉
The calcined body (adding 0.2% by weight of SiO ₂ and 0.15% by weight of CaCO ₃ before calcining) was pulverized by a dry vibration mill, and then annealed in the air at 1000 ° C. for 5 minutes to obtain a bonded magnet. The specific coercive force iHc of ferrite powder is 343.0kA / m (4.31kOe)
There is a statement that it is. However, (BH) of an anisotropic bonded magnet produced by binding this ferrite powder with a binder
max is less than the sintered anisotropic ferrite magnet.

Japanese Patent Application Laid-Open No. 60-223095 discloses that a hard ferrite magnetic powder, a rare earth cobalt magnetic powder and a binder are blended at a predetermined ratio, kneaded and molded, and the temperature coefficient of magnetic flux density is -0.03 to -0.20. A field magnet bonded to a magnetic field device for a bubble memory device at% / ° C. is described. However, the field magnet has a temperature coefficient of the magnetic flux density adjusted to the above range, and thus has poor heat resistance and poor magnetization.

In Rare Metal News, No. 1936 (published on Feb. 8, 1999), Sm—Fe—N-based magnetic powder, ferrite magnetic powder, and a binder are blended at a predetermined ratio and kneaded.
(BH) max of anisotropic bonded magnet obtained by molding in a magnetic field is 31.8 to 39.8 kJ, which is equivalent to high-performance material of sintered ferrite magnet
There is a suggestion that it can be / m ³ (4-5 MGOe). However, from the study of the present inventors, the bond magnet produced by mixing the conventional Sm-Fe-N-based magnetic powder, the ferrite magnetic powder, and the binder at a predetermined ratio, has insufficient magnetizability and heat resistance, and is not practical. It turned out to be low.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a new high-performance magnet having a maximum energy product (BH) max exceeding that of a conventional anisotropic ferrite sintered magnet and further having improved magnetization or heat resistance. It is to provide a high performance anisotropic bonded magnet. Another object of the present invention is to provide a high-performance rotating machine and a magnet roll configured using the high-performance anisotropic bonded magnet.

[0007]

The anisotropic bonded magnet of the present invention which has solved the above-mentioned problems has a main component composition of R _α T _10.
0-α-β N _β (R is at least one of the rare earth elements including Y
T is Fe or Fe and Co;
α and β are 5% α ≦ 20 and 5 ≦ β ≦ 30 in atomic%, respectively. ) And an average particle size of more than 10 μm having a substantially magnetoplumbite type crystal structure.
It is characterized by being substantially composed of a ferrite sintered magnetic powder having a size of 00 μm or less and a binder binding the two types of magnetic powder. In the anisotropic bonded magnet of the present invention, the main component composition is R _α T _100-α-β N _β (R is at least one rare earth element including Y, and T is Fe or Fe and Co
Where α and β are each atomic% and 5 ≦ α ≦ 20, 5 ≦ β
≦ 30. ) And an RTN-based magnetic powder represented by the following formula:
e It is characterized by being substantially composed of a ferrite sintered magnetic powder having an e ²⁺ content of 0.10% by weight or less and a binder binding the two magnetic powders. The anisotropic bonded magnet of the present invention has a (BH) max exceeding that of an anisotropic ferrite sintered magnet, and has better magnetizability or better heat resistance than conventional rare earth bonded magnets.

[0008] The ferrite sintered magnetic powder constituting the anisotropic bonded magnet of the present invention has a main component composition of (A1 _{- xR'x} ) O.
· N is _{[(Fe 1-y M y} ) 2 O 3] ( atomic ratio) (A is Sr and / or Ba, R 'is at least one of rare earth elements including Y La, Pr, Nd And at least one selected from Ce
Is Co or Co and Zn. ), 0.01 ≦ x ≦
0.4, 0.005 ≦ y ≦ 0.04 and 5.0 ≦ n ≦ 6.4
When substantially consisting of an anisotropic ferrite sintered magnet powder having a magnetoplumbite type crystal structure, the bonded magnet of the present invention has a (BH) max exceeding that of the anisotropic ferrite sintered magnet and has good magnetism. And has remarkably good heat resistance.

Further, the ferrite sintered magnetic powder constituting the anisotropic bonded magnet of the present invention is A′O.nFe ₂ O ₃ (atomic ratio) (A ′ is Sr and / or Ba, and 5.0 ≦ n ≦
6.4. ) And (A _1−x R ′ _x ) On · ([Fe _{1− y My} ) ₂ O ₃ ] (atomic ratio) (A is Sr and And / or Ba; R ′ is at least one kind of rare earth element containing Y and always contains at least one kind selected from La, Pr, Nd and Ce;
Is Co or Co and Zn. ), 0.01 ≦ x ≦
When it is made of sintered ferrite magnetic powder having a main component composition represented by 0.4, 0.005 ≦ y ≦ 0.04, and 5.0 ≦ n ≦ 6.4, it has good magnetizability, has heat resistance enough for practical use, and is inexpensive. An isotropic bonded magnet can be obtained.

The anisotropic bonded magnet of the present invention has radial anisotropy or polar anisotropy, and thus has high practicality. Also,
The rotating machine using the anisotropic bonded magnet of the present invention has high efficiency, and a high-definition image can be obtained in a copying machine equipped with a magnet roll using the bonded magnet of the present invention.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The RTN-based magnetic powder used for the anisotropic bonded magnet of the present invention will be described below. RT-
The average particle size of the N-based magnetic powder is preferably 1 to 10 μm (measured by a laser diffraction type particle size distribution analyzer manufactured by Sympatec: Herros Rhodes), and more preferably 2 to 5 μm. If the average particle size is less than 1 μm, oxidative deterioration becomes remarkable, the packing density becomes remarkably small, and (BH) max of the anisotropic bonded magnet is greatly reduced. If the average particle size exceeds 10 μm, the (BH) max of the anisotropic bonded magnet is greatly reduced. R-
T-N magnet powder as _Th 2 _{Zn 17} type or _Th 2 Ni
_It is preferable to use Sm-TN-based magnetic powder (T is Fe or Fe and Co) having a _17- type crystal structure phase as a main phase.

The R content is preferably 5 to 20% in atomic%. If the R content is less than 5%, iHc is greatly reduced,
If it exceeds 0%, the residual magnetic flux density Br is greatly reduced. R for S
It is acceptable to contain at least one rare earth element (including Y) other than m, but at room temperature, it is 397.9 kA / m (5 kOe) or more.
In order to obtain iHc, the ratio of Sm to R in atomic% is 50% or more in atomic%, more preferably 90% or more, and particularly preferably R = Sm excluding the inevitable R component. The nitrogen content is preferably 5 to 30% in atomic%, and 10 to
More preferably, it is set to 20%. If the nitrogen content is less than 5%, iHc and (BH) max that can be used practically cannot be obtained, and if it exceeds 30%, iHc and (BH) max are greatly reduced.

Some of Sm and Fe are replaced with Co, Ni, Ti, C
r, Mn, Zn, Cu, Zr, Nb, Mo, Ta, W,
It can be substituted with at least one selected from Ru, Rh, Hf, Re, Oe and Ir. These substitution amounts are Co
It is preferred that the content be 10 atomic% or less based on the total amount of Sm and Fe except for the above. If it is more than this, (BH) max is significantly reduced. In the case of Co substitution, the decrease in (BH) max is small,
Substitution is possible in the range of 0.1 to 70 atomic% with respect to the content, and the Curie temperature can be increased. Part of nitrogen is C,
Substitution is possible with at least one selected from P, Si, S and Al, and the substitution amount is preferably 10 atomic% or less based on the nitrogen content. If the substitution amount is larger than this, the decrease in iHc becomes remarkable, which is not preferable.

As the RTN-based magnetic powder, ThMn is used.
_The main phase is a _12- type crystal structure phase, and R ″ in atomic%.
The main component composition of _{5 to 10} T _bal N _{3 to 20} (R ″ is at least one rare earth element including Y and includes Nd and / or Pr, and T is Fe or Fe and Co) And an average particle size of 1 to 10 μm (according to Herros Rhodes) .To increase (BH) max, the total R ″ content is set to 100 atomic% and the Nd and / or Pr content is set to The content is preferably at least 50 at%, more preferably at least 90 at%, and particularly preferably the case where R ″ comprises Nd and / or Pr except for the inevitable R ″ component. The N content is preferably from 3 to 20 at%, more preferably from 5 to 15 at%.
If the R ″ content is outside the range of 5 to 10 atomic% and the N content is outside the range of 3 to 20 atomic%, it becomes difficult to produce an anisotropic bonded magnet that can withstand practical use.

As a raw material alloy of the RTN-based magnetic powder, a strip casting method, a mold casting method or R / D (reduction / diffusion)
Adjusted to the corresponding composition of RTN-based magnetic powder by the method
It is preferable to use a system mother alloy. Next, the RT-based master alloy is heated to 1010 to 1280 ° C. in an inert gas atmosphere containing no nitrogen.
Heat for 1 to 40 hours and cool to room temperature. By the homogenization heat treatment, a segregated phase such as α-Fe forms a solid solution in the substrate. If the homogenizing heat treatment condition is less than 1010 ° C. × 1 hour, a solid solution effect useful for industrial production cannot be obtained, and if it exceeds 1280 ° C. × 40 hours, the effect of the homogenizing heat treatment is saturated.

Next, pulverization is performed. Grinding of the RT master alloy to be subjected to the nitriding treatment, or grinding of the RTN based alloy after the nitriding treatment is performed by a hammer mill, a disc mill, a vibration mill, an attritor, a jet mill, or the like maintained in an inert gas atmosphere. It is preferable to carry out. Nitriding is performed by reducing the powder of the nitriding master alloy with nitrogen gas, mixed gas of nitrogen and hydrogen, ammonia gas, mixed gas of ammonia and hydrogen, mixed gas of ammonia and nitrogen, or mixed reduction of ammonia and argon. 300 ~ 650 ℃ × 0 in gas atmosphere (air flow).
It is preferable to heat for 1 to 30 hours. Heating conditions for nitriding are 3
If the temperature is less than 00 ° C. × 0.1 hour or more than 650 ° C. × 30 hours, it becomes difficult to obtain useful magnetic properties. Although the mother alloy powder for nitriding inevitably contains hydrogen, the RTN-based magnetic powder obtained by nitriding in a nitriding gas containing hydrogen is allowed to contain 0.01 to 10 atomic% of hydrogen.

The ferrite sintered magnetic powder used for the anisotropic bonded magnet of the present invention will be described below. Suitable anisotropic ferrite sintered magnetic powders have a substantially magnetoplumbite crystal structure. Substantially having a magnetoplumbite-type crystal structure includes a phase having a magnetoplumbite-type crystal structure phase as a main phase, and it is preferable that the magnetic property manifesting phase comprises only the magnetoplumbite-type crystal structure phase.

The main component composition is (A _1−x R ′ _x ) On · ([Fe _{1− y My} ) ₂ O ₃ ] (atomic ratio) (A is Sr and / or Ba, and R ′ is Is at least one kind of rare earth element containing Y and always contains at least one kind selected from La, Pr, Nd and Ce;
Is Co or Co and Zn. ), 0.01 ≦ x ≦
0.4, 0.005 ≦ y ≦ 0.04 and 5.0 ≦ n ≦ 6.4
The reasons for limiting the composition of the sintered anisotropic ferrite magnetic powder having a substantially magnetoplumbite crystal structure will be described below. n (molar ratio) is preferably from 5.0 to 6.4, more preferably from 5.6 to 6.2, and particularly preferably from 5.8 to 6.0. When n exceeds 6.4, a different phase other than the magnetoplumbite phase (α-Fe ₂ O ₃ etc.)
Is remarkable, iHc is greatly reduced, and when n is less than 5.0, (BH) max is greatly reduced.

The value of x is preferably 0.01 to 0.4, and 0.1 to 0.3.
Is more preferable, and 0.15 to 0.25 is particularly preferable. x is 0.4
If it is more than (BH) max and iHc, the addition effect is not recognized when x is less than 0.01. R 'is allowed to inevitably contain rare earth elements (including Y) other than La, Pr, Ce and Nd. La, Pr, Ce as R 'raw material
It is inexpensive and preferable to use at least two kinds of mixed rare earth oxides or hydroxides selected from Nd and Nd. To increase the saturation magnetization, La, P occupying R '
The ratio of at least one selected from r, Ce and Nd is preferably at least 50 at%, more preferably at least 70 at%, and even more preferably at least 95 at%. R ′ is L except for the R ′ component which is unavoidably mixed.
Most preferably, it consists of a.

It is preferable to select Co as M in order to improve the heat resistance of the anisotropic bonded magnet of the present invention. When Co and Zn are selected as M, C occupying M
The ratio of o is preferably at least 50 atomic%, and 70 atomic%
More preferably, it is more preferably at least 90 atomic%. If the ratio of Co to M is less than 50 atomic%, iHc is greatly reduced and heat resistance is deteriorated.

To realize the purpose of charge compensation, y and x
Ideally, the relationship of y = x / (2.0n) needs to be established. However, if y is not less than x / (2.6n) and not more than x / (1.6n), the effect of the charge compensation can be reduced. Without any substantial damage,
preferable. For example, ideal charge compensation when R = La and M = Co can be treated as being canceled by La ³⁺ and Co ²⁺ . When the value of y deviates from x / (2.0 n), it is determined that the Fe ³⁺ of the Fe site in the magnetoplumbite phase of the anisotropic ferrite sintered magnetic powder becomes Fe ²⁺ and the charge compensation is performed. . Example 1 to be described later
From the comparison of ~ 3, it was found that heat treatment in an excess oxygen atmosphere resulted in iHc
Significantly the Fe ²⁺ reduction is possible to improve, it has been found can greatly improve the heat resistance of the anisotropic bonded magnet. Fe2 ⁺ content to increase iHc (heat resistance)
It is preferably 0.005 to 0.10% by weight, more preferably 0.01 to 0.07% by weight. Fe ²⁺ content 0.00
It is difficult for industrial production to make the content less than 5% by weight.
^When the content of ²⁺ exceeds 0.10% by weight, the effect of improving iHc is reduced. In a typical example, the preferred range of y is 0.005 to
0.04, and more preferably 0.01 to 0.03.

In the anisotropic ferrite sintered magnetic powder having the above-mentioned main component composition, it is recognized that the R 'concentration in the crystal grain boundaries tends to be higher than the R' concentration in the crystal grains. In particular, n = 5.7-6.2, x =
0.15 to 0.3 and 1.0 <x / 2ny ≦ 1.3, more preferably
R ′ excess composition of 1.05 ≦ x / 2ny ≦ 1.25, and C
The aO content to 0.5 to 1.5 wt%, 0 to SiO ₂ content.
High (BH) max and high iHc at 25-0.55% by weight
And the tendency that the R ′ concentration in the crystal grain boundaries is higher than the R ′ concentration in the crystal grains becomes remarkable.

The anisotropic ferrite sintered magnetic powder used in the present invention has a main component composition of A'O.nFe ₂ O ₃ (atomic ratio) (A 'is Sr and / or Ba, and n (molar ratio) =
5.0 to 6.4. The main components represented by ()) are highly practical.

Exceeds conventional anisotropic sintered ferrite magnets
In order to have (BH) max, the main component composition is (A _1-x R ′)
_{x) O · n [(Fe} 1-y M y) 2 O 3] ( Anisotropic sintered ferrite magnet powder and the main component composition A'O · n of atomic ratio)
It is preferable to mix the anisotropic ferrite sintered magnetic powder of Fe ₂ O ₃ (atomic ratio) at a weight ratio of 50 to 100: 50 to 0 to obtain an anisotropic bonded magnet magnetic powder. The advantages of using them in a mixture _A'O · nFe 2 _{O 3} magnetic powder _{(A 1-x} R '
_x ) On · n [(Fe _{1- y My} ) ₂ O ₃ ] (B
H) max and iHc are low but inexpensive.

The average particle size of the anisotropic ferrite sintered magnetic powder is preferably 2 to 1000 μm (measured by a laser diffraction type particle size distribution measuring device manufactured by Sympatec: Heros Rhodes), and more than 10 μm and 300 μm or less. More preferably, 30-1
00 μm is particularly preferred. If the average particle size is less than 2 μm, the packing density will decrease significantly and (BH) max will drop significantly. If the average particle size exceeds 1000 μm, the surface condition of the anisotropic bonded magnet will deteriorate, and it will be applied to applications with a narrow magnetic gap. May be difficult.

The production of the sintered anisotropic ferrite magnetic powder used in the present invention is carried out by the following steps: mixing of raw material powder → ferrite formation by calcination (solid phase reaction) → pulverization → forming in a magnetic field → sintering → pulverization → heat treatment → crushing "Is practical. Or “mixing of raw material powder → ferrite formation by calcination (solid-state reaction) → grinding → molding in a magnetic field → grinding → sintering → heat treatment → disintegration”
Is also useful. In the latter manufacturing process, the compact is pulverized to an average particle size of 2 to 1000 μm and sintered. “Crushing” is a process performed to improve the magnetic field orientation by dissolving the aggregation state after the heat treatment. If the aggregation is mild, “crushing” may be omitted. The heating conditions for calcination are preferably 1150-1300 ° C. × 1-5 hours. If the heating conditions for the calcination are less than 1150 ° C. × 1 hour, ferrite formation will be insufficient, and if it exceeds 1300 ° C. × 5 hours, the calcined material will be hardened and the grindability will deteriorate.

Coarse pulverization and fine pulverization are performed by arbitrarily combining known pulverizers. It is practical to use a dry or wet type attritor, ball mill, vibrating mill or the like. In order to increase iHc and (BH) max of the anisotropic bonded magnet, the average particle size of the finely ground powder is preferably 0.4 to 0.9 μm (measured by an air permeation method), more preferably 0.6 to 0.8 μm. More preferred. The average crystal grain size in the c-axis direction of the finally obtained anisotropic ferrite sintered magnetic powder can be made to be 2 μm or less, preferably 1 μm or less by making the finely pulverized average particle diameter.

Next, molding in a wet magnetic field or dry magnetic field is performed. Molding in a magnetic field is 397.9 to 1193.7 kA / m (5 to 15
It is preferable to carry out at a molding pressure of about 0.35 to 0.45 ton / cm ² while applying a magnetic field of kOe). The density of the molded body thus obtained is about 2.6 to 3.2 Mg / m ³ (g / cm ³ ). Next, the compact is sintered under heating conditions of 1180 to 1230 ° C. × 1 to 5 hours.
If the heating condition is less than 1180 ° C. × 1 hour, the density of the sintered body does not increase sufficiently and (BH) max decreases, and if the heating condition exceeds 1230 ° C. × 5 hours, the crystal grains become coarse and the decrease in iHc becomes remarkable. Next, if necessary, the sintered body is pulverized, and then sieved or air-classified to adjust the particle size distribution and the average particle size to predetermined values. Next, heat treatment is performed. Although iHc can be increased by air heat treatment, it is preferable that the oxygen partial pressure (PO ₂ ) be more than 0.02 MPa (0.2 atm),
More preferably 0.03MPa (0.3atm) or more, particularly preferably
Heat treatment is preferably performed at 750 to 950 ° C. for 0.5 to 5 hours in an excess oxygen atmosphere adjusted to 0.05 to 0.1 MPa (0.5 to 1 atm). When the oxygen partial pressure is 0.02 MPa or less, the improvement of iHc and the reduction of Fe ²⁺ are not sufficient, and when the oxygen partial pressure exceeds 0.1 MPa, the effect of the heat treatment is saturated. If the heating condition of the heat treatment is less than 750 ° C. × 0.5 hours, iHc cannot be practically improved, and if it exceeds 950 ° C. × 5 hours, the aggregation of ferrite magnetic powder becomes remarkable, and iHc and (BH) max decrease remarkably.

When the anisotropic ferrite sintered magnetic powder has an appropriate amount of S
When iO ₂ and CaO are contained, a dense sintered body structure is obtained, and useful magnetic properties are obtained. SiO ₂ is an additive that suppresses the growth of crystal grains during sintering.
Is preferably 0.05 to 0.55%, more preferably 0.25 to 0.55%. When the content of SiO ₂ is less than 0.05%, uneven crystal growth during sintering becomes remarkable, and iHc deteriorates. When the content exceeds 0.55%, the growth of crystal grains is excessively suppressed, and the degree of orientation progresses along with the growth of crystal grains. Is insufficiently improved, and Br and (BH) max are greatly reduced. On the other hand, CaO is an element that promotes crystal grain growth, and the CaO content is preferably 0.35 to 1.5% by weight, more preferably 0.4 to 1.2%, and particularly preferably 0.5 to 1.0%. If the CaO content exceeds 1.5%, the crystal grain growth proceeds excessively during sintering, and iHc is greatly reduced. If the CaO content is less than 0.35%, a useful addition effect cannot be obtained, and the degree of orientation is insufficiently improved. (BH) max deteriorates.

IH of the sintered ferrite magnetic powder at room temperature
c is 278.5 kA / m (3.5 kOe) or more, preferably 358.1 kA / m
(4.5 kOe) or more, particularly preferably 437.7 kA / m (5.5 kOe)
To above it is preferably to 0.1 to 1 wt% of the total Al content and the Cr content in the _{(Al 2 O 3 + Cr 2} O 3) in terms of, and more preferably, 0.2 to 0.5 wt% . If the content is less than this, the effect of addition is virtually not obtained,
If the content exceeds this, the superiority to the conventional ferrite magnetic powder for bonded magnets is lost.

The compounding weight ratio of the RTN-based magnetic powder and the sintered ferrite magnetic powder is preferably 5 to 95%: 95 to 5%, more preferably 20 to 80%: 80 to 20%. More preferred. If the ratio is out of this range, it exceeds the anisotropic ferrite sintered magnet (B
H) max and it is difficult to improve the magnetization and heat resistance.

It is practical to use a known thermosetting resin, thermoplastic resin or rubber material as a binder constituting the compound. Particularly, a binder having a low viscosity is selected by applying an orientation magnetic field having a practical strength of 159.2 to 795.8 kA / m (2 to 10 kOe), preferably 238.7 to 477.5 kA / m (3 to 6 kOe). It is preferable to increase (BH) max of the anisotropic bonded magnet to be obtained.

It is practical to employ a compression molding method in a magnetic field, an extrusion molding method in a magnetic field, or an injection molding method in a magnetic field as a molding method. Alternatively, heat the compound to 80-300 ° C,
Next, it is rolled into a sheet through a gap between twin rolls whose average interval is adjusted to 0.01 to 3 mm. Next, while maintaining the obtained sheet in the heating state, an orientation magnetic field of 159.2 to 795.8 kA / m (2 to 10 kOe) is applied along the thickness direction of a predetermined portion of the sheet to impart anisotropy, and then Cooling. By performing this operation over the entire length of the sheet, an anisotropic sheet-like bonded magnet can be produced. If the heating temperature is lower than 80 ° C, the moldability is poor and it is difficult to impart anisotropy. If the heating temperature is higher than 300 ° C, the binder is thermally decomposed and (BH) max is greatly reduced.

The shape and dimensions of the anisotropic bonded magnet of the present invention are not particularly limited, but the outer diameter is 5 to 60 mm, the thickness defined by (outer diameter−inner diameter) / 2 is 0.3 to 3 mm, and the axial length. : 0.
A ring-shaped molded product of 3 to 50 mm (preferably one having radial or polar anisotropy) is rich in practicality. The shape and dimensions of the anisotropic bonded magnet having radial or polar anisotropy for magnet roll use are not particularly limited, but the outer diameter is 10 to 60 mm, and the axial length is 200 to 3
Forming into a cylindrical shape with a length of 50 mm and (length / outer diameter) ≧ 5 is rich in practicality. For use in small copiers and printers, the outer diameter is preferably 10 to 30 mm, particularly 10 to 20 mm, and a small diameter of (axial length / outer diameter) ≧ 5 is preferred.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) [RTN magnetic powder] Sm _9.1 Fe _76.8 M in atomic%
R- having a main component composition represented by n _0.5 N _13.6
The TN magnetic powder was finely pulverized by a jet mill to an average particle size of 4.0 μm. Next, finely pulverized by a wet ball mill using hexane, the average particle size is 2.1 μm, the particle size distribution is 0.5 to 28.
Anisotropic R-T-N-based magnetic powder having a thickness of μm and a magnetic property exhibiting phase of a Th ₂ Zn ₁₇ type crystal structure phase was obtained. The average particle size and the particle size distribution were measured by a laser diffraction type particle size distribution measuring device (trade name: Heros Rhodes) manufactured by Sympatec.

[SrLaCo-based anisotropic ferrite sintered magnetic powder heat-treated in an oxygen-excess atmosphere] SrCO ₃ powder (containing Ba and Ca as impurities), α-Fe ₂ O ₃ powder, La ₂
Using O ₃ powder and Co ₃ O ₄ powder, Sr after calcination
_0.80 La _0.20 Fe _11.70 Co _0.20 O
_18.85 , and a SiO ₂ powder and CaC were added to the mixture.
O ₃ powder was added 0.25 wt% and 0.2 wt%, and mixed. Next, it was calcined at 1300 ° C. for 2 hours in the air. The obtained calcined product was coarsely crushed and then dry coarsely crushed with a roller mill to obtain a coarse powder. Next, the resultant was finely wet-pulverized by an attritor to obtain a slurry containing finely pulverized powder having an average particle diameter of 0.6 μm (by an air permeation method). S as a sintering aid in the early stage of fine grinding
rCO ₃ powder, SiO ₂ powder, CaCO ₃ powder, Al ₂
O ₃ powder and La ₂ O ₃ powder, respectively 0.25 wt% based on the total weight of the coarse powder was charged into milled, 0.40 wt%, 0.8
%, 0.25% and 0.6% by weight. The obtained finely pulverized slurry was compression-molded in a magnetic field of 795.8 kA / m (10 kOe) to obtain a molded body. Next, the molded body is
Sintered at 00 ° C for 2 hours, La / Co = 1.2 (La excess composition)
The following anisotropic ferrite sintered magnet was obtained. (Sr _0.77 La _0.23 ) O.5.72 [(Fe
_0.983 Co _0.017 ) ₂ O ₃ ] SiO ₂ content: 0.40% by weight, CaO content: 0.57% by weight, converted to (Al ₂ O ₃ + Cr ₂ O ₃ ) (Al + C)
r) Content: 0.32% by weight The obtained sintered body was coarsely crushed by a jaw crusher and then dry coarsely ground by a roller mill to obtain a coarse powder. Next, it was sieved to 200 mesh under. Next, this powder was heat-treated at 870 ° C. × 2 hours in an excess oxygen atmosphere of oxygen partial pressure: PO ₂ = 0.1 MPa (1 atm), and then cooled to room temperature. Next, the heat-treated powder was immersed in water, and the immersion was heated to 80 ° C. to evaporate water. The average particle size of the obtained anisotropic ferrite sintered magnetic powder (hereinafter referred to as SrLaCo-based ferrite sintered magnetic powder-1) was 55.4 μm (according to Heros Rhodes). Analysis of Fe ^{2 +} content per unit weight of SrLaCo ferrite sintered magnetic powder-1
The content of Fe was 0.05% by weight, and all other Fe was Fe ³⁺ .

[Anisotropic Bonded Magnet] Prepared RTN
The magnetic powder and the SrLaCo ferrite sintered magnetic powder-1 were put into a stirrer at a weight ratio of 80/20 and mixed. Next, the mixed magnetic powder: 10
0 parts by weight, liquid epoxy resin: 2.8 parts by weight, curing agent (DD
S; diaminodiphenylsulfone): 0.7 parts by weight and methyl ethyl ketone (boiling point: 79.5 ° C.): 2.8 parts by weight were charged into a stirrer, and then stirred at 20 rpm for 20 minutes to form a slurry. According to the obtained slurry (compound),
At room temperature, compression molding was performed in a wet magnetic field under the conditions of an orientation magnetic field strength of 477.5 kA / m (6 kOe) and a molding pressure of 784 MPa (8 tons / cm ² ). The obtained molded body was heated at 85 ° C. for 1 hour to remove the solvent (demethyl ethyl ketone), and then heated at 170 ° C. for 2 hours.
After heating and curing for an hour, No. 1 anisotropic bonded magnet shown in Table 1 was obtained.

Next, Table 1 was prepared in the same manner as in No. 1 except that the RTN-based magnetic powder and the SrLaCo-based ferrite sintered magnetic powder-1 were blended in a weight ratio of 50/50 and 20/80. Nos. 2 and 3 anisotropic bonded magnets shown were produced. Next, assuming practical built-in magnetization, after demagnetizing each of the bonded magnets No. 1 to 3,
20 ℃ by BH tracer, magnetizing magnetic field intensity 795.8kA / m
The magnet was magnetized at (10 kOe), a demagnetization curve was drawn, and iHc and (BH) max were measured. Next, the magnetism of each of the bonded magnets Nos. 1 to 3 was defined by the following equation and evaluated. (Magnetization) = (Br _{5 kOe} ) / (Br _{50 kOe} ) × 100
(%) Br _{5 kOe} : Br value when the magnetizing magnetic field strength is 397.9 kA / m (5 kOe) Br _{50 kOe} : Br value when the _magnetizing magnetic field strength is 3979 kA / m (50 kOe) Were machined to have a permeance coefficient (Pc) of 2; (thickness in the magnetization direction) / (diameter) = 0.7. Next, it was magnetized at 2387.4 kA / m (30 kOe) at 20 ° C., and the total magnetic flux (Φ) was measured. Next magnetized No.1
Each of the bonded magnet samples Nos. 1 to 3 was taken at 40 ° C, 45 ° C, 50 ° C,
55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃
℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃
After heating for 1 hour to each temperature of 135 ° C., 135 ° C. and 140 ° C., it was cooled to room temperature. Next, the total magnetic flux of each sample after cooling (Φ ')
At the temperature at which the rate of change of the total magnetic flux (irreversible demagnetization rate) defined by the following formula reached 5%, the heat-resistant temperatures of the samples Nos. 1 to 3 were evaluated. (Irreversible demagnetization rate) = (Φ−Φ ′) / (Φ) × 100 (%) The above results are shown in Table 1.

(Example 2) [SrLaCo-based anisotropic ferrite heat-treated in air atmosphere]
Sintered magnetic powder] Oxygen partial pressure: PO_Two= 0.02MPa (0.2atm) atmosphere
Same as Example 1 except that the heat treatment was performed at 870 ° C. for 2 hours in an atmosphere.
Thus, the main component composition is (Sr_0.77La_0.23) O ・ 5.72 [(Fe
_0.983Co_0.017) ₂ O₃] And SiO₂Content: 0.41% by weight, Ca
O content: 0.55% by weight, (Al₂O₃+ Cr₂O₃)
(Al + Cr) content converted: 0.33% by weight, unit weight
Fe per²⁺Content = 0.08 wt%, other Fe
All Fe³⁺With an average particle size of 58.4μm
Sintered magnetic powder (hereinafter referred to as SrLaCo-based ferrite sintered magnetic powder-2)
Say. ) Got.

[Anisotropic bonded magnet] R-T- of Example 1
N-based magnetic powder: 20 parts by weight and SrLaCo-based ferrite sintered magnetic powder
-2: 80 parts by weight were mixed, and a slurry was prepared in the same manner as in Example 1 except that this mixed magnetic powder was used, and an anisotropic bonded magnet was prepared and evaluated. The results are shown in No. 13 of Table 1.

(Example 3) [SrLaCo-based anisotropic ferrite sintered magnetic powder without heat treatment] The 200-mesh-under sieved powder obtained in Example 1 was anisotropic ferrite-sintered magnetic powder (hereinafter referred to as SrLaCo-based ferrite). Sintered magnetic powder-3). The SrLaCo-based ferrite sintered magnetic powder-3 had a Fe ²⁺ content of 0.11% by weight, and all other Fe contained were Fe ³⁺ .

[Anisotropic bonded magnet] R-T- of Example 1
N-based magnetic powder: 20 parts by weight and SrLaCo-based ferrite sintered magnetic powder
-3: 80 parts by weight were mixed, and a slurry was prepared in the same manner as in Example 1 except that this mixed magnetic powder was used, and an anisotropic bonded magnet was prepared and evaluated. The results are shown in No. 23 of Table 1.

(Example 4) [Sr-based anisotropic ferrite sintered magnetic powder heat-treated in oxygen-excess atmosphere] Sr-based anisotropic ferrite sintered magnet manufactured by Hitachi Metals, Ltd. (trade name: YBM-6BF) Was crushed and then sieved to 200 mesh under. Then, in an oxygen-excess atmosphere of oxygen partial pressure: PO ₂ = 0.1 MPa (1 atm),
Heat treatment was performed at 0 ° C. × 3 hours, and then cooled to room temperature. Next, the heat-treated powder is immersed in water, and
The mixture was heated to ℃ to evaporate water, and then cooled. Thus, an anisotropic ferrite sintered magnetic powder (hereinafter, referred to as Sr-based ferrite sintered magnetic powder) having a main component composition represented by SrO.6Fe ₂ O ₃ (atomic ratio) and having an average particle size of 60 μm was prepared.

[Anisotropic Bonded Magnet] R-T- of Example 1
N-based magnetic powder: 50 parts by weight, SrLaCo-based ferrite sintered magnetic powder
1:30 parts by weight and Sr-based ferrite sintered magnetic powder: 20 parts by weight were mixed. Example 1 was followed except that this mixed magnetic powder was used.
A slurry was prepared in the same manner as described above to prepare and evaluate an anisotropic bonded magnet. The results are shown in No. 32 of Table 1.

Comparative Example 1 RTN magnetic powder of Example 1: 100 parts by weight, liquid epoxy resin: 2.8 parts by weight, curing agent (DDS): 0.7 parts by weight, and methyl ethyl ketone: 2.8 parts
A part by weight was put into a stirrer and stirred to obtain a slurry. From this slurry, an anisotropic bonded magnet was prepared and evaluated in the same manner as in Example 1. The results are shown in No. 51 of Table 1.

(Comparative Example 2) Nd-Fe-B-based anisotropic magnetic powder (trade name: MQA-T material) manufactured by MQI (Magnequench International), 100 parts by weight, liquid epoxy resin: 2.8 parts by weight, cured 0.7 parts by weight of the agent (DDS) and 2.8 parts by weight of methyl ethyl ketone were charged into a stirrer and stirred to obtain a slurry. From this slurry, an anisotropic bonded magnet was prepared and evaluated in the same manner as in Example 1. The results are shown in No. 61 of Table 1.

Comparative Example 3 Nd-Fe-B based isotropic magnetic powder (trade name: MQP-B material) manufactured by MQI (Magnequench International), 100 parts by weight, liquid epoxy resin: 2.8 parts by weight, cured 0.7 parts by weight of the agent (DDS) and 2.8 parts by weight of methyl ethyl ketone were charged into a stirrer and stirred to obtain a slurry. From this slurry, an anisotropic bonded magnet was prepared and evaluated in the same manner as in Example 1. The results are shown in No. 71 of Table 1.

Comparative Example 4 SrCO ₃ powder (containing Ba and Ca as impurities), α-Fe ₂ O ₃ powder, La ₂ O
₃ powder and Co ₃ O ₄ powder, after calcination (Sr
_0.85 La _0.15 ) O.5.85 [(Fe _0.98 Co
_0.02 ) ₂ O ₃ ]. Next, it was calcined in the air at 1200 ° C. for 2 hours. The obtained calcined product was coarsely crushed and then dry coarsely crushed with a roller mill to obtain a coarse powder. Next, fine powder having an average particle size of 1.15 μm (by the air permeation method) was obtained by a dry vibration mill. Next, at 820 ° C x 2 in an atmosphere of PO ₂ = 0.02 MPa (0.2 atm).
Heat treated for an hour and then cooled to room temperature. Next, it is immersed in water and then dried to obtain a ferrite powder for bond magnet having an average particle size of 1.20 μm (by the air permeation method) (hereinafter referred to as SrLaCo
This is called a ferrite-bonded magnetic powder. ) Got.

Next, the RTN-based magnetic powder of Example 1 and SrLaCo
80/20, 50/50 and 20/80 with ferrite bonded magnetic powder
To obtain three types of mixed magnetic powder. Each of these three types of mixed magnetic powder: 100 parts by weight, liquid epoxy resin:
2.8 parts by weight, 0.7 parts by weight of a curing agent (DDS), and 2.8 parts by weight of methyl ethyl ketone were mixed and charged into a stirrer. Then, stirring was performed to obtain three kinds of slurries. From these three types of slurries, anisotropic bonded magnets were prepared and evaluated in the same manner as in Example 1 thereafter. The results are shown in Table 1 Nos. 81 to 8
See Figure 3.

[0051]

[Table 1] ・ Fe ²⁺ content of SrLaCo ferrite sintered magnetic powder-1: 0.
05% by weight ・ Fe ²⁺ content of SrLaCo ferrite sintered magnetic powder-2: 0.
08% by weight ・ Fe ²⁺ content of SrLaCo ferrite sintered magnetic powder-3: 0.
11% by weight

From Table 1, the following findings were obtained. (1) No. 3 of Example 1, Examples 2 and 3 and No. 83 of Comparative Example 4
It can be seen from the comparison that No. 3 containing SrLaCo-based ferrite sintered magnetic powder-1 heat-treated in excess oxygen had the highest (BH) max, iHc, magnetization and heat resistance temperature. Further, from a comparison between Examples 2 and 3, it can be seen that when the SrLaCo-based anisotropic ferrite sintered magnetic powder is subjected to a heat treatment in the air, (BH) max, iHc, and the heat resistance temperature are improved. That is, heat treatment is performed on the anisotropic ferrite sintered magnetic powder to obtain the (BH) of the anisotropic bonded magnet.
Since the iHc can be increased without lowering the max and the magnetization is improved, a rotating machine with high output and high heat resistance can be constructed even when the strength of the magnetization magnetic field is limited to a low level. The (BH) max and iHc of the anisotropic bonded magnet are improved by the heat treatment because the strain and minute defects introduced during the pulverization of the sintered ferrite magnetic powder are reduced or eliminated, and the Fe ²⁺ content is reduced. Is judged to be effective. (2) In Example 1 and Comparative Example 4, when the RTN-based magnetic powder and the ferrite magnetic powder were compared at the same compounding ratio, N
o.1 is No.81, No.2 is No.82, No.3 is No.8
It can be seen that (BH) max, iHc, and heat-resistant temperature are all higher than those of 3. (3) No. 2 of Example 1, Example 4 and No. 8 of Comparative Example 4
From the comparison of 2, a predetermined ratio of the RTN-based magnetic powder of Example 1, the SrLaCo-based ferrite sintered magnetic powder-1 heat-treated in excess oxygen, and the Sr-based ferrite sintered magnetic powder heat-treated in excess oxygen was obtained. (BH) max exceeding No. 82 of Comparative Example 4 was obtained in the anisotropic bonded magnet No. 32 produced by blending with the above, which proves to be useful as an inexpensive anisotropic bonded magnet. (4) It can be seen that the anisotropic bonded magnets of each of the above examples have better magnetizability and higher heat resistance temperature than the conventional rare earth bonded magnets of Comparative Examples 1 to 3, and are therefore more practical.

(Example 5) The slurry No. 2 of Example 1 was placed in a molding cavity having an outer diameter of 25 mm at room temperature and an inner diameter (outer diameter of the core of the die) of 22 mm, which was installed in a compression molding machine. Filled. Next, radial orientation magnetic field: 318.3 kA / m (4 kO
While applying e), molding was performed in a wet magnetic field at a molding pressure of 784 MPa (8 tons / cm ² ) to obtain a molded body. 80
Deheated by heating to ℃, then heat-cured and outer diameter: 25m
m, an inner diameter: 22 mm, and a length in the axial direction: 15 mm were obtained. FIG. 1 shows the result of performing symmetrical 8-pole magnetization under the condition that the total magnetic flux amount is saturated in the circumferential direction of the outer diameter surface of the bonded magnet, and then measuring the surface magnetic flux density waveform in the circumferential direction of the outer diameter surface. From Fig. 1, the maximum value of the surface magnetic flux density is 0.
High values of 275 to 0.28 T (2.75 to 2.8 kG) were obtained.
It was also measured surface magnetic flux density (Bo) along the axial direction of the outer diameter surface N ₁ pole magnetized ring-like bonded magnet. This Bo measurement was performed over an axial length of 9 mm (± 4.5 mm from the axial center) excluding the portion from the axial ends to 3 mm toward the center in order to exclude the influence of both ends. . As a result, the maximum (Bo.max.) And minimum (Bo.mi.)
Difference from n.): dBo was less than 0.004 T (40 G), and the variation in Bo was small.

(Comparative Example 5) Radial anisotropy was obtained in the same manner as in Example 5 except that the slurry of Comparative Example 2 was used.
Ring-shaped bonded magnet with symmetric 8-pole magnetization (outer diameter:
(25 mm, inner diameter: 22 mm, axial length: 15 mm), and the surface magnetic flux density waveform and dBo in the outer diameter surface circumferential direction were measured. FIG. 1 shows the surface magnetic flux density waveform in the circumferential direction of the outer diameter surface. The maximum value of the surface magnetic flux density was as low as about 0.190 T (1900 G). In addition, dBo exceeded 0.005 T (50 G), and it was found that the variation in Bo was large.

(Example 6) The slurry of No. 2 of Example 1 was placed in a molding die cavity having an outer diameter of 25 mm at room temperature and an inner diameter (outer diameter of the core of the die) of 22 mm, which was installed in a compression molding machine. Filled. Next, the polar anisotropic orientation magnetic field (symmetric 8 poles): 318.
While applying 3 kA / m (4 kOe), molding pressure: 784 MPa (8
Ton / cm ² ) in a wet magnetic field to obtain a molded body. The obtained molded body was heated to 80 ° C. to remove the solvent, and then heat-cured to obtain a ring-shaped polar anisotropic bonded magnet having an outer diameter of 25 mm, an inner diameter of 22 mm, and an axial length of 15 mm. Symmetrical 8-pole magnetization was performed under the condition that the total magnetic flux was saturated along the anisotropy imparting direction of the bonded magnet. Thereafter, the surface magnetic flux density waveform and dBo in the circumferential direction of the outer diameter surface were measured in the same manner as in Example 5. As a result, the maximum value of the surface magnetic flux density is 0.27 to 0.28 T (2.7 to 2.8
kG). DBo is 0.005T (50
G) and the variation in Bo was small.

Comparative Example 6 A ring-shaped bonded magnet (outer diameter) having symmetric 8-pole polar anisotropy and magnetized in the same manner as in Example 6 except that the slurry of Comparative Example 2 was used. : 25mm,
(Inner diameter: 22 mm, axial length: 15 mm), and the surface magnetic flux density waveform and dBo in the outer peripheral surface circumferential direction were measured. As a result, the maximum value of the surface magnetic flux density was as low as about 0.195 T (1.95 kG), and dBo was more than 0.005 T (50 G), and the variation in Bo was large.

Each of the ring-shaped bonded magnets produced in Examples 5 and 6 and Comparative Examples 5 and 6 was assembled on the rotor side of a brushless motor to form a brushless motor. As a result of measuring the maximum efficiency of each of these brushless motors, the maximum efficiency of the motor incorporating the ring-shaped bonded magnets of Example 5 and Example 6 was relatively high, and the ring-shaped bonded magnets of Comparative Examples 5 and 6 were compared. It has been found that the maximum efficiency of the motor incorporating the A is low. The average air gap spacing between the rotor and stator of each brushless motor is
0.3 mm.

(Example 7, Comparative Example 7) [Sheet-shaped bonded magnet] Three types of magnetic powders listed in Table 2: 9
1.5 parts by weight, EEA resin (MB-870): 6.2 parts by weight, dispersant (DH-37): 1.0 part by weight, lubricant (Slipax E): 0.5
Parts by weight and silicone oil (KF968, manufactured by Shin-Etsu Chemical Co., Ltd.): 0.8 parts by weight were put into a heating / pressing type kneader and kneaded to prepare three types of compounds. Each of the RTN-based magnetic powders described in Table 2 was produced in Example 1. Further, the SrLaCoZn-based ferrite sintered magnetic powder shown in Table 2 is obtained by calcining Sr _0.80 La _0.20 Fe _11.70 Co.
_0.10 Zn _0.10 O _{18. 85} , and Al ₂ O ₃ at the time of pulverization.
This is an anisotropic ferrite sintered magnetic powder having an average particle diameter of 62.9 μm prepared in the same manner as the SrLaCo-based ferrite sintered magnetic powder-1 of Example 1 except that no was added. The main component composition of the SrLaCoZn-based ferrite sintered magnetic powder is represented by the following composition formula: (Sr _0.77 La _0.23 ) O.5.72 [(Fe _0.983
Co _0.0085 Zn _{0 . 0085) 2 O 3], SiO} 2 content: 0.42 wt%, CaO content: 0.59 _wt%, in terms of _{(Al 2 O 3 + Cr 2} O 3) (Al + C
r) Content: 0.04% by weight, Fe ²⁺ = 0.05% by weight, and all other Fe contained were Fe ³⁺ . Next, each of the compounds was put into an extruder that was sequentially heated, and extruded by passing through a parallel orientation magnetic field zone (applied magnetic field intensity: 397.9 kA / m (5 kOe)) provided near the extrusion port of the extruder. Next, the sheet was cut to a length of 320 mm in the axial direction to obtain a sheet-like anisotropic bonded magnet 16 having a thickness t of 2 mm as shown in the sectional view of FIG.

[Magnet Roll] The magnet roll 23 shown in FIG. 2 was manufactured and evaluated as follows. First, the groove 13 penetrating in the axial direction was formed in the developing magnetic pole portion of the cylindrical isotropic ferrite sintered magnet 17 fixed to the shaft 22. Next, the produced sheet-like anisotropic bonded magnets 16 were fixed to the grooves 13, respectively, to form magnet rolls 23. Since the concave portion 14 is formed to extend in the axial direction of the sheet-like anisotropic bonded magnet 16, the air gap magnetic flux distribution waveform immediately above the developing magnetic pole is configured to have two peaks.
The surface magnetic flux density Bo immediately above N ₁ pole along the axial direction of the magnet roll 23 is measured to obtain the results shown in Table 2. Bo in Table 2
(Average value) is shown as a relative value. In this Bo measurement, in order to exclude the influence of both ends, the portion from the both ends in the axial direction to 10 mm toward the center is excluded, and the axial length is 300 m
m (± 150 mm from the axial center). As a result, the magnet rolls of Nos. 106 and 107 were No. 1 of Comparative Example 7.
It has a higher Bo (average value) than the 11 magnet rolls, indicating that it has high performance. It should be noted that even when the cylindrical magnet 17 is made of a conventional isotropic bonded magnet or anisotropic ferrite bonded magnet, a high-performance magnet roll can be formed.

Example 7 is a case where the thickness t of the sheet-like anisotropic bonded magnet is 2 mm, and is 159.2 to 795.8 kA / m (2 to
Extrusion molding or calender roll molding while applying a practical orientation magnetic field strength of 10 kOe) yields a thickness with a (BH) max exceeding that of a conventional anisotropic ferrite sintered magnet: 0.0
A sheet-like anisotropic bonded magnet of 1 to 3 mm can be produced.

[0061]

[Table 2]

From Table 2, it was found that the No. 106 magnet roll formed using a sheet-like anisotropic bonded magnet prepared by blending SrLaCoZn-based ferrite sintered magnetic powder had the highest (average Bo value). . In the case of No. 107 using SrLaCo-based ferrite sintered magnetic powder-1, it was higher than Comparative Example 7 (Bo
Average value).

When each of the anisotropic ferrite sintered magnetic powders described in the above examples was subjected to X-ray diffraction, only the X-ray diffraction peak of the magnetoplumbite type crystal structure phase was observed.
It was found to have a magnetoplumbite type crystal structure.

In Examples 1 to 6, a case was described in which a slurry was prepared using a liquid epoxy resin as a binder and compression-molded in a magnetic field, but the present invention is not limited to this. For example, if a compound is manufactured by using a thermoplastic resin such as polyamide resin as the binder, and compression molding in a magnetic field or injection molding in a magnetic field is performed in a warm state, a high-performance anisotropic bonded magnet can be manufactured, and the compound and anisotropic material can be formed. It is possible to recycle the bonded magnet and to reduce the cost.

In the compound used in the present invention, in addition to the magnetic powder and the binder, a dispersant of the magnetic powder (for example, phenol type), a coupling agent (for example, a silane type coupling agent), a lubricant (for example, waxes), and a plasticizer (for example, wax). For example
DOP, DBP, etc.), an antioxidant or the like is added alone or in combination to improve moldability, oxidation resistance, strength, magnetic properties and the like. The total amount of these additives is preferably 3% by weight or less, more preferably 0.1 to 2% by weight.

[0066]

As described above, according to the present invention, the maximum energy product exceeding the conventional sintered anisotropic ferrite magnet is obtained.
It is possible to provide a new high-performance anisotropic bonded magnet having (BH) max and further improved magnetization or heat resistance. Further, a high-performance rotating machine and a magnet roll can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a surface magnetic flux density waveform of an anisotropic bonded magnet of the present invention.

FIG. 2 is a sectional view of a main part showing an example of a magnet roll of the present invention.

[Explanation of symbols]

13 grooves provided in parallel with the axial direction, 14 concave parts, 15 convex parts,
16 sheet-like bonded magnets, 17 magnet roll base, 22 shafts, 23 magnet rolls.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kubota 5200 Sankajiri, Kumagaya-shi, Saitama Hitachi Metals, Ltd. Inside Magnetic Materials Research Laboratories (72) Takashi Takami 5200 Sankajiri, Kumagaya-shi, Saitama Magnet Hitachi Metals, Ltd. F-term in Materials Research Laboratory (reference) 4K018 AA27 AB01 AC01 BA11 BA18 BC12 BD01 GA02 JA01 KA46 5E040 AA04 AA09 AB04 BB04 BB05 BD01 HB01 HB03 HB06 HB11 HB15 HB17 NN01 NN06 NN18

Claims (9)

[Claims] 1. The composition of the main component is R _α T _100-α-β N
_β (R is at least one kind of rare earth element including Y, T is Fe or Fe and Co, and α and β are respectively 5% α ≦ 20 and 5 ≦ β ≦ 30 in atomic%.) From an RTN-based magnetic powder represented by the following formula, a ferrite sintered magnetic powder having a magnetoplumbite-type crystal structure and having an average particle diameter of more than 10 μm and not more than 1000 μm, and a binder binding the two types of magnetic powder. An anisotropic bonded magnet, which is substantially obtained. 2. The main component composition is R_αT_100-α-βN
_β(R is at least one rare earth element including Y
T is Fe or Fe and Co, and α and β are
In atomic%, 5 ≦ α ≦ 20 and 5 ≦ β ≦ 30. )so
R-T-N-based magnetic powder and substantially magnetoplan
It has a bite type crystal structure and Fe ²⁺Content is 0.
10% by weight or less of ferrite sintered magnetic powder and the above two types of magnetic powder
And a binder that binds substantially.
Anisotropic bonded magnet. 3. The ferrite sintered magnetic powder having a substantially magnetoplumbite type crystal structure comprises: (A _1-x R ′ _x ) On · ([Fe _{1- y My} ) ₂ O ₃ ] (atom (A is Sr and / or Ba, R ′ is at least one kind of rare earth element including Y, and always contains at least one kind selected from La, Pr, Nd and Ce, and M ′
Is Co or Co and Zn. ), 0.01 ≦ x ≦
3. The anisotropic bonded magnet according to claim 1, having a main component composition represented by 0.4, 0.005≤y≤0.04, and 5.0≤n≤6.4. 4. The ferrite sintered magnetic powder having substantially a magnetoplumbite type crystal structure, wherein A′O.nFe ₂ O ₃ (atomic ratio) (A ′ is Sr and
/ Or Ba, and 5.0 ≦ n ≦ 6.4. ) And (A _1−x R ′ _x ) On · ([Fe _{1− y My} ) ₂ O ₃ ] (atomic ratio) (A is Sr and And / or Ba; R ′ is at least one kind of rare earth element containing Y and always contains at least one kind selected from La, Pr, Nd and Ce;
Is Co or Co and Zn. ), 0.01 ≦ x ≦
3. The anisotropic bonded magnet according to claim 1, comprising sintered ferrite magnetic powder having a main component composition represented by 0.4, 0.005≤y≤0.04, and 5.0≤n≤6.4. 5. The ratio of the RTN-based magnetic powder to the whole magnetic powder contained in the anisotropic bonded magnet is 5 to 95% by weight, and the ratio of the sintered ferrite magnetic powder is 95 to 5% by weight. The anisotropic bonded magnet according to claim 1. 6. The anisotropic bonded magnet according to claim 1, which has radial anisotropy or polar anisotropy. 7. The anisotropic bonded magnet according to claim 1, which has a sheet shape having a thickness of 0.01 to 3 mm. 8. A rotating machine comprising the anisotropic bonded magnet according to any one of claims 1 to 7. 9. A magnet roll comprising the anisotropic bonded magnet according to any one of claims 1 to 7.