CN1770337A - Method for preparing bonded permanent ferrite by direct injection forming after in-situ polymerization - Google Patents
Method for preparing bonded permanent ferrite by direct injection forming after in-situ polymerization Download PDFInfo
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- CN1770337A CN1770337A CN 200510037291 CN200510037291A CN1770337A CN 1770337 A CN1770337 A CN 1770337A CN 200510037291 CN200510037291 CN 200510037291 CN 200510037291 A CN200510037291 A CN 200510037291A CN 1770337 A CN1770337 A CN 1770337A
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Abstract
This invention relates to one process method to process sticking permanent magnetic iron oxidation by direct injection and shaping, which comprises the following steps: adding the strontium ferrite powder into the aminocaprolactam solution to make it into adhesive agent of polyamide by use of in-situ polymerization reaction technique; each magnetic power surface is evenly covered with one layer of polyamide to realize the evenly mixing; then using the double screw bar or single screw to cover thepolyamide adhesive for injection mole to prepare adhesive permanent magnetic part.
Description
Technical field
The present invention relates to magnet forming processing technology field, specifically be meant the method for preparing bonded permanent ferrite by direct injection forming after in-situ polymerization.
Background technology
Bonded permanent magnet is with magnetic and resin or macromolecular material is mixing is prepared into final size and shape with mold pressing, injection moulding, rolling process etc. with it, makes after solidifying again.Bonded permanent magnet because have that cost is low, dimensional accuracy is high, freedom shape is big, mechanical strength is good, light specific gravity, can automated production in enormous quantities continuously, the production efficiency height, advantages such as good product consistency, industry, agricultural, military affairs, science and technology, medical science, life various aspects have been widely used in, the spindle motor of for example a large amount of miniature precision electric motors that use, stepping motor, hard disk drive etc.Wherein, bonded permanent magnet accounts for 94% of total output in the application quantity maximum of rotary device (mainly being the electrical micro-machine that computer is used).
Injection moulding bonded permanent magnet body technology is that the permanent magnetism powder with certain particle size mixes with binding agent that (binding agent can account for 30%, volume fraction) carries out granulation after, in injector, to be heated to uniform temperature through the magnetic of granulation is injected to powder in the die cavity by an aperture with screw rod again, magnetic is squeezed into required form in die cavity, and in die cavity, cool off and curing, obtain the bonded permanent magnet of required size and shape.Can be used for injection molding magnetic has the mixed powder etc. of NdFeB, SmCo, ferrite, Alnico and above-mentioned several powder, and wherein the magnetic of injection moulding bonding NdFeB magnet is the highest.According to the used magnetic and the difference of technology, the injection magnet has the branch of isotropism and anisotropy again.
The injection moulding bonded permanent magnet has following several characteristics:
(1) magnet shape degree of freedom height.Can prepare comparatively complicated shape, as motor with thin-walled ring bonded permanent magnet.If use die pressing, then be difficult to preparation.
(2) dimensional accuracy height.Adopt the injection molding of high dimensional accuracy to make high accuracy injection moulding bonded permanent magnet, do not need the back processing as sintered magnet, product can directly be used in precision optical machinery and automobile with on the device.
(3) cost is lower than compression molding method.To compare processing step few with die pressing, the efficient height, but and a plurality of magnets of a shot, therefore, have lower technology cost.
(4) can carry out combination forming.Utilize injection molding technology bonded permanent magnet and metalwork can be combined and carry out one-shot forming, form embedded assembling device, realize the shape variation, complicated of moulding article assembly.This is the great advantage of injection moulding bonded permanent magnet.
As mentioned above, the injection molding technique process of bonded permanent magnet mainly comprises: (1) mixes magnetic and binding agent, through mixing and granulation, obtains dry pellet; (2) pellet is delivered to the heating chamber heating with spiral guide bar, be injected into mould molding, promptly get product after the cooling.
Nylon 6 is a kind of binding agents the most frequently used in the injection molding technique of bonded permanent magnet, and addition generally is 20～30% (percentage by volumes).
There is following deficiency in prior art: (1) prior art adopts earlier mixes magnetic and binding agent, through mixing and granulation, then pellet with screw extruder heating, injection molding production technology, complex technical process, need the technological parameter of control many, as mix, temperature control during mixing, moulding, the time control when pressure control during mixing, moulding and mixing, mixing, moulding etc.; (2) carry out granulation and processing and forming after prior art adopts ferromagnetic oxide powder and polymer directly mixes, because the difference of magnetic and polymer proportion in order to make two kinds of material mixing even, must be carried out Forced Mixing, to mixing apparatus and technological requirement height; (3) combine as the form of mainly utilizing coupling agent to pass through chemical bond between the magnetic of inorganic matter and the organic binder bond, bond strength is low, also can the uniformity of mixing between magnetic and the binding agent be exerted an influence.
Summary of the invention
Purpose of the present invention is exactly in order to solve above-mentioned the deficiencies in the prior art part, to propose to utilize the method for preparing bonded permanent ferrite by direct injection forming after in-situ polymerization.
The present invention is achieved through the following technical solutions: described preparing bonded permanent ferrite by direct injection forming after in-situ polymerization comprises the steps and process conditions:
The first step, in mass fraction, it is dry that the strontium ferrite magnetic powder of 1～3 part coupling agent and 97～99 parts is mixed the back, coats processing strontium ferrite magnetic powder is carried out surface;
Second step was heated to 60～80 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-4～1 * 10
-1Pa dewatered 5～10 minutes;
The 3rd step charging under the condition of nitrogen gas, in mass fraction, joined 2～5 parts catalyst, 0.1～0.5 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, made caprolactam monomer solution; In 9～20 parts of described caprolactam monomer solution, add 80～91 parts of strontium ferrite magnetic powders of handling through first step coating, stir, make mixed system; Described mixed system is heated to 150 ℃, insulation 30～120, be heated to 180 ℃ again, be incubated 30～120 minutes, and then be heated to 250～260 ℃, be incubated 180～360 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of strontium ferrite magnetic powder surface in situ;
The 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer uses twin screw or single screw extruder under the effect of 1000kA/m alignment magnetic field, be injected into die for molding, cooling in 280～300 ℃, prepare bonded permanent ferrite.
Coupling agent that the first step in the technique scheme is used and used catalyst of the 3rd step are general coupling agent and catalyst in such technology, in order to realize the object of the invention better, coupling agent preferred silane coupling agent KH of the present invention～550, KH～560 or KH～570; The preferred 6-aminocaprolc acid of described catalyst, 12-aminolauric acid or 12.
In order to realize the object of the invention better, the described condition of nitrogen gas that charges into preferably charged into 0.2～0.8Pa high pure nitrogen the 3rd step in the technique scheme.
The present invention compared with prior art has following advantage and beneficial effect:
1, the present invention by home position polymerization reaction after magnetic surface forms uniform binding agent coating, utilize twin-screw (single screw rod) extruder directly magnetic to be injected cavity forming, magnetic polymer mixed, magnet molding process are finished continuously, omitted granulation and pellet reheats process, simplify the magnet moulding process, saved the Granulation Equipments investment;
2, the present invention mixes the permanent magnetism powder with polymer monomer, utilize the home position polymerization reaction technology, polymer as binding agent is generated at the magnetic surface in situ, coated equably the one layer of polymeric on the surface of every magnetic, magnetic and polymer reliable connection have guaranteed that magnetic mixes with the full and uniform of binding agent.
Embodiment
Below in conjunction with embodiment, the present invention is done detailed description further, but embodiments of the present invention are not limited thereto.
Embodiment one
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite magnetic powder of 1 part KH550 and 99 parts, coats processing magnetic is carried out surface;
Second step was heated to 60 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-4Dewatered 5 minutes;
The 3rd step under the condition that charges into the 0.2Pa high pure nitrogen, in mass fraction, added 2 parts 12-aminolauric acid, 0.3 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, make caprolactam monomer solution; In 12 parts of caprolactam monomer solution, add 88 parts of strontium ferrite magnetic powders of handling through the first step, stir, make mixed system; Mixed system is heated to 150 ℃, and insulation 60 is heated to 180 ℃ again, be incubated 30 minutes, and then be heated to 250 ℃, be incubated 240 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 290 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.58g/cm
3, maximum magnetic energy product (BH)
MaxBe 13.3kJ/m
3
Embodiment two
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite powder of 3 parts KH550 and 97 parts, magnetic is carried out surface coat processing;
Second step was heated to 70 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-3Dewatered 7 minutes;
The 3rd step charged into the 0.5Pa high pure nitrogen, in mass fraction, added 5 parts 6-aminocaprolc acid, 0.4 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, made caprolactam monomer solution; In 10 parts of caprolactam monomer solution, add 90 parts of strontium ferrite magnetic powders of handling through the first step, make mixed system; Mixed system is heated to 150 ℃, be incubated 30 minutes, be heated to 180 ℃ again, be incubated 60 minutes, and then be heated to 250 ℃, be incubated 180 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 300 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.71g/cm
3, maximum magnetic energy product (BH)
MaxBe 14.6kJ/m
3
Embodiment three
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite powder of 3 parts KH560 and 97 parts, coats processing magnetic is carried out surface;
Second step was heated to 80 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-1Pa dewatered 10 minutes;
The 3rd step under the condition that charges into the 0.8Pa high pure nitrogen, in mass fraction, added 5 parts 12,0.5 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, make caprolactam monomer solution; In 9 parts of caprolactam monomer solution, add 91 parts of strontium ferrite magnetic powders of handling through the first step, stir, make mixed system; Mixed system is heated to 150 ℃, insulation 120, be heated to 180 ℃ again, be incubated 90 minutes, and then be heated to 260 ℃, be incubated 180 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 295 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.80g/cm
3, maximum magnetic energy product (BH)
MaxBe 15.2kJ/m
3
Embodiment four
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite powder of 3 parts KH570 and 97 parts, coats processing magnetic is carried out surface;
Second step was heated to 80 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-2Pa dewatered 8 minutes;
The 3rd step under the condition that charges into the 0.6Pa high pure nitrogen, in mass fraction, added 2 parts 6-aminocaprolc acid, 0.1 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, make caprolactam monomer solution; In 15 parts of caprolactam monomer solution, add 85 parts of strontium ferrite magnetic powders of handling through the first step, stir, make mixed system; Mixed system is heated to 150 ℃, and insulation 90 is heated to 180 ℃ again, be incubated 60 minutes, and then be heated to 250 ℃, be incubated 360 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 280 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.52g/cm
3, maximum magnetic energy product (BH)
MaxBe 12.8kJ/m
3
Embodiment five
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite powder of 1 part KH570 and 99 parts, coats processing magnetic is carried out surface;
Second step was heated to 80 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 3 * 10
-3Pa dewatered 8 minutes;
The 3rd step under the condition that charges into the 0.4Pa high pure nitrogen, in mass fraction, added 5 parts 12-aminolauric acid, 0.2 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, make caprolactam monomer solution; In 18 parts of caprolactam monomer solution, add 82 parts of strontium ferrite magnetic powders of handling through the first step, stir, make mixed system; Mixed system is heated to 150 ℃, insulation 120, be heated to 180 ℃ again, be incubated 120 minutes, and then be heated to 260 ℃, be incubated 220 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 300 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.40g/cm
3, maximum magnetic energy product (BH)
MaxBe 12.3kJ/m
3
Embodiment six
The first step in mass fraction, mixes the back intensive drying with the strontium ferrite powder of 1 part KH560 and 99 parts, coats processing magnetic is carried out surface;
Second step was heated to 60 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 5 * 10
-4Pa dewatered 6 minutes;
The 3rd step under the condition that charges into the 0.2Pa high pure nitrogen, in mass fraction, added 2 parts 12,0.4 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, make caprolactam monomer solution; In 20 parts of caprolactam monomer solution, add 80 parts of strontium ferrite magnetic powders of handling through the first step, stir, make mixed system; Mixed system is heated to 150 ℃, insulation 30, be heated to 180 ℃ again, be incubated 120 minutes, and then be heated to 260 ℃, be incubated 360 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of magnetic surface in situ;
In the 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer under the effect of 1000kA/m alignment magnetic field, is injected into die for molding, cooling in 290 ℃ with twin screw or single screw extruder, prepares bonded permanent ferrite.
After testing, the density of bonded permanent ferrite is 3.35g/cm
3, maximum magnetic energy product (BH)
MaxBe 11.4kJ/m
3
As mentioned above, can realize the present invention preferably.
Claims (4)
1, the method for preparing bonded permanent ferrite by direct injection forming after in-situ polymerization is characterized in that comprising the steps and process conditions:
The first step, in mass fraction, it is dry that the strontium ferrite magnetic powder of 1～3 part coupling agent and 97～99 parts is mixed the back, coats processing strontium ferrite magnetic powder is carried out surface;
Second step was heated to 60～80 ℃ with caprolactam monomer (CL) and is fused into liquid, was evacuated to 1 * 10
-4～1 * 10
-1Pa dewatered 5～10 minutes;
The 3rd step charging under the condition of nitrogen gas, in mass fraction, joined 2～5 parts catalyst, 0.1～0.5 part stearic bicine diester ethylenediamine (EBS) in the caprolactam melt of 100 part of second step preparation, made caprolactam monomer solution; In 9～20 parts of described caprolactam monomer solution, add 80～91 parts of strontium ferrite magnetic powders of handling through first step coating, stir, make mixed system; Described mixed system is heated to 150 ℃, insulation 30～120, be heated to 180 ℃ again, be incubated 30～120 minutes, and then be heated to 250～260 ℃, be incubated 180～360 minutes, make caprolactam monomer generate polyamide (nylon) 6, make the strontium ferrite magnetic powder that the surface is coating polyamide (nylon) 6 in the polymerization of strontium ferrite magnetic powder surface in situ;
The 4th step, the strontium ferrite magnetic powder that prepared surface of the 3rd step is being coated caprolactam monomer uses twin screw or single screw extruder under the effect of 1000kA/m alignment magnetic field, be injected into die for molding, cooling in 280～300 ℃, prepare bonded permanent ferrite.
According to the method for the described preparing bonded permanent ferrite by direct injection forming after in-situ polymerization of claim 1, it is characterized in that 2, the coupling agent of the described first step is a silane resin acceptor kh-550, KH-560 or KH-570.
According to the method for the described preparing bonded permanent ferrite by direct injection forming after in-situ polymerization of claim 1, it is characterized in that 3, the 3rd step, described catalyst was 6-aminocaprolc acid, 12-aminolauric acid or 12.
According to the method for the described preparing bonded permanent ferrite by direct injection forming after in-situ polymerization of claim 1, it is characterized in that 4, the 3rd step, the described condition of nitrogen gas that charges into was for charging into 0.2～0.8Pa high pure nitrogen.
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|---|---|---|---|
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| CNB2005100372912A CN100568418C (en) | 2005-09-16 | 2005-09-16 | The method of preparing bonded permanent ferrite by direct injection forming after in-situ polymerization |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100368344C (en) * | 2006-05-30 | 2008-02-13 | 华南理工大学 | Preparation process of anisotropic permanent magnetic ferrite |
| CN104658734A (en) * | 2013-11-21 | 2015-05-27 | 北矿磁材科技股份有限公司 | Spherical magnetic composite material and preparation method thereof |
| CN106750973A (en) * | 2016-12-31 | 2017-05-31 | 东莞市淦宏信息科技有限公司 | A kind of production technology of improved conductive agglomerate |
| CN106750974A (en) * | 2016-12-31 | 2017-05-31 | 东莞市淦宏信息科技有限公司 | A kind of production technology of conductive agglomerate |
| CN112223578A (en) * | 2020-09-30 | 2021-01-15 | 浙江工业大学 | Method for preparing high-toughness strontium ferrite/PPS injection molding granules through in-situ polymerization |
-
2005
- 2005-09-16 CN CNB2005100372912A patent/CN100568418C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100368344C (en) * | 2006-05-30 | 2008-02-13 | 华南理工大学 | Preparation process of anisotropic permanent magnetic ferrite |
| CN104658734A (en) * | 2013-11-21 | 2015-05-27 | 北矿磁材科技股份有限公司 | Spherical magnetic composite material and preparation method thereof |
| CN104658734B (en) * | 2013-11-21 | 2017-07-18 | 北矿磁材科技股份有限公司 | A kind of Magnetic Spherical composite and preparation method thereof |
| CN106750973A (en) * | 2016-12-31 | 2017-05-31 | 东莞市淦宏信息科技有限公司 | A kind of production technology of improved conductive agglomerate |
| CN106750974A (en) * | 2016-12-31 | 2017-05-31 | 东莞市淦宏信息科技有限公司 | A kind of production technology of conductive agglomerate |
| CN112223578A (en) * | 2020-09-30 | 2021-01-15 | 浙江工业大学 | Method for preparing high-toughness strontium ferrite/PPS injection molding granules through in-situ polymerization |
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| CN100568418C (en) | 2009-12-09 |
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Granted publication date: 20091209 Termination date: 20120916 |