阅读说明：本技术 注射成型用高流动性钐铁氮柔性粘结永磁体及其制备方法 (High-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding and preparation method thereof ) 是由 王峰 刘冬 熊君 胡国辉 全小康 刘荣明 刘辉 贾立颖 于 2020-07-11 设计创作，主要内容包括：本发明公开了注射成型用高流动性钐铁氮柔性粘结永磁体及其制备方法,包含以下组分：钐铁氮磁粉90-94重量份、橡胶类粘结剂3-5重量份、增塑剂2-3重量份、热稳定剂0.5-1重量份和润滑剂0.5-1重量份。本发明使钐铁氮柔性粘结永磁体符合可最新的ROHS2.0标准认证标准,具备了出口创汇的条件；填补了注射成型柔性钐铁氮磁体高流动性区域的空白,提升了目前柔性粘结磁体的使用温度上限,从目前的80度提高到了120度,拓宽了使用领域,增加了其稳定性和可靠性。(The invention discloses a high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding and a preparation method thereof, wherein the high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet comprises the following components: 90-94 parts of samarium-iron-nitrogen magnetic powder, 3-5 parts of rubber binder, 2-3 parts of plasticizer, 0.5-1 part of heat stabilizer and 0.5-1 part of lubricant. According to the invention, the samarium-iron-nitrogen flexible bonded permanent magnet meets the latest ROHS2.0 standard authentication standard, and has the condition of earning foreign exchange through export; the blank of the high-fluidity area of the injection-molded flexible samarium-iron-nitrogen magnet is filled, the upper limit of the service temperature of the conventional flexible bonded magnet is improved, the service temperature is improved to 120 ℃ from 80 ℃, the use field is widened, and the stability and the reliability of the flexible samarium-iron-nitrogen magnet are improved.)

1. Injection moulding is with flexible bonding permanent magnet of high mobility samarium iron nitrogen, its characterized in that: comprises the following components:

90-94 parts of samarium-iron-nitrogen magnetic powder, 3-5 parts of rubber binder, 2-3 parts of plasticizer, 0.5-1 part of heat stabilizer and 0.5-1 part of lubricant.

2. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 1 and the preparation method thereof are characterized in that: the rubber adhesive component is a blending system consisting of chlorinated polyethylene, polyvinyl chloride and thermoplastic polyurethane elastomer.

3. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 2, characterized in that: the rubber adhesive comprises the following components: 5-15 parts of chlorinated polyethylene, 40-45 parts of polyvinyl chloride and 45-50 parts of thermoplastic polyurethane elastomer.

4. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 3, characterized in that: the average polymerization degree of the polyvinyl chloride is before 650-980.

5. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 4, characterized in that: the plasticizer is a blending plasticizer system consisting of a modified citrate plasticizer which does not contain benzene ring structure and has molecular weight more than 500 and epoxidized soybean oil,

the components are as follows: 50-70 parts of modified citrate plasticizer and 30-50 parts of epoxidized soybean oil.

6. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 1, characterized in that: the heat stabilizer is a blending system of a calcium zinc stabilizer and a magnesium oxide component, and comprises the following components: 30-60 parts of calcium zinc stabilizer and 40-70 parts of magnesium oxide.

7. The high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding according to claim 1, characterized in that: the lubricant is a blending system consisting of modified ethylene bis fatty acid amide and chlorinated paraffin, and comprises the following components: 20-40 parts of modified ethylene bis fatty acid amide and 60-80 parts of chlorinated paraffin.

8. The preparation method of the high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding is characterized by comprising the following steps of: comprising preparing a high-fluidity samarium-iron-nitrogen flexibly bonded permanent magnet for injection molding according to any one of claims 1 to 7, comprising the steps of:

s1: two-stage mixing plasticizing treatment: weighing the components according to the corresponding weight parts, putting the components into an internal mixer for mixing and plasticizing by a one-stage method, wherein the mixing temperature of the internal mixer is 150-; rolling the obtained banburying material on a rolling mill at the roll temperature of 140-;

s2: rolling treatment: rolling the obtained banburying material on a rolling mill at the roll temperature of 120 ℃ and 130 ℃ until the banburying material is rolled into a plate-shaped material with the thickness of 3-3.5mm,

s3: cutting into granules and injection molding: cutting the obtained plate-shaped material into particles with the size of 3-3.5mm multiplied by 3-3.5mm, and then molding on an injection machine at the injection temperature of 170-190 ℃.

Technical Field

The invention relates to the technical field of samarium-iron-nitrogen flexible bonded permanent magnets, in particular to a high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding and a preparation method thereof.

Background

Samarium iron nitrogen magnetic powder is anisotropic rare earth magnetic powder used for bonded magnet, and is especially suitable for bonded magnet formed by injection molding due to the characteristics of small particle size (about 1-2 microns), high magnetic powder performance and magnetic field orientation.

Injection molded magnets require high melt flow to fill the mold for injection molding into complex shaped magnetic devices. At present, injection molding magnetic devices are divided into rigid magnets and flexible magnets in forms, wherein the rigid magnets have higher strength after being molded and cooled, but cannot be bent and deformed, and are not suitable for deformation assembly and use, such as micromotor motors, inductors and other application fields; the latter can be bent and deformed after being formed and cooled, and can be matched with complex firmware for installation and use.

In the prior art, PPS or PA is mostly adopted as a binder to be mixed with samarium-iron-nitrogen magnetic powder for injection molding in the aspect of injection molding of a bonded magnet, and a molded product is rigid; the patent documents of the injection molding of the flexible samarium-iron-nitrogen magnetic powder are rarely reported, and due to the limitation of the formula, the used plasticizer is a dicarboxylate plasticizer containing a benzene ring structure, so that the plasticizer does not meet the latest ROHS2.0 standard requirement, the use temperature is lower than 80 ℃, and the use environment is limited; the most important point is that the melt fluidity of the material is lower, less than 80g/10min, which is not beneficial to the molding of the device with complex shape by filling the mold.

For example, the invention named as '2011103338872' is an injection molding permanent magnet composite material containing polyphenylene sulfide and a preparation method thereof, the patent adopts an injection molding permanent magnet composite material which is formed by blending and injection molding polyphenylene sulfide and a magnetic powder system consisting of neodymium iron boron, samarium iron nitrogen and ferrite, an injection product is rigid, contains neodymium iron boron, belongs to rare earth neodymium, is limited by rare earth resources, and has higher price.

The invention with the application number of '201810730159' is named as an environment-friendly flexible magnet injection soft granule, a preparation method thereof and an environment-friendly permanent magnet ring for a pneumatic device prepared by using the same, and the patent does not specifically indicate that the environment-friendly flexible magnet injection soft granule contains samarium iron nitrogen magnetic powder; the plasticizer component contains a benzene ring structure; the melt flow rate is less than 80g/10 min; the upper temperature resistance limit of the material is not specified.

Also disclosed is a high performance polyamide/samarium iron nitrogen magnetic composite and method of making the same, as disclosed in application No. 2015104541078, which uses polyamide as the binder and the article is rigid.

Disclosure of Invention

The invention aims to overcome the existing defects and provide a high-fluidity samarium iron nitrogen flexible bonded permanent magnet for injection molding and a preparation method thereof, wherein a modified citrate plasticizer without a benzene ring structure is adopted to ensure that the samarium iron nitrogen flexible bonded magnet meets the latest ROHS2.0 standard certification standard, and through the research and development of a formula, the melt fluidity and the upper limit of the use temperature of the samarium iron nitrogen flexible bonded magnet are improved, the melt fluidity is more than 80g/10min, the device with a complex shape and a large length-diameter ratio is convenient to mold, the upper limit of the temperature resistance of the device is improved to 120 ℃ from the current 80 ℃, the use field is widened, the stability and the reliability of the device are improved, and the problems in the background technology can be effectively solved.

In order to solve the technical problems, the invention provides the following technical scheme:

in a first aspect, the present invention provides a high flow samarium-iron-nitrogen flexible bonded permanent magnet for injection molding comprising the following components:

90-94 parts of samarium iron nitrogen magnetic powder, 3-5 parts of rubber binder, 2-3 parts of plasticizer meeting ROHS2.0 standard, 0.5-1 part of heat stabilizer and 0.5-1 part of lubricant, wherein the samarium iron nitrogen magnetic powder is commercially available isotropic or anisotropic magnetic powder.

Preferably, the rubber binder component is a blending system composed of chlorinated polyethylene, polyvinyl chloride and thermoplastic polyurethane elastomer.

Preferably, the rubber adhesive comprises the following components: 5-15 parts of chlorinated polyethylene, 40-45 parts of polyvinyl chloride and 45-50 parts of thermoplastic polyurethane elastomer.

Preferably, the polyvinyl chloride is products of model SG 6-model SG8 which conform to the GB/T5761-2006 standard, and the average polymerization degree of the polyvinyl chloride is before 650-980.

Preferably, the plasticizer meeting the ROHS2.0 standard is a blended plasticizer system consisting of a modified citrate plasticizer which does not contain a benzene ring structure and has a molecular weight of more than 500 and epoxy soybean oil,

the components are as follows: 50-70 parts of modified citrate plasticizer and 30-50 parts of epoxidized soybean oil.

Preferably, the heat stabilizer is a blending system of a calcium zinc stabilizer and a magnesium oxide component, and the components are as follows: 30-60 parts of calcium zinc stabilizer and 40-70 parts of magnesium oxide.

Preferably, the lubricant is a blending system consisting of modified ethylene bis fatty acid amide and chlorinated paraffin, and comprises the following components: 20-40 parts of modified ethylene bis fatty acid amide and 60-80 parts of chlorinated paraffin.

The technical scheme of the invention has the following beneficial effects: by implementing the scheme of the invention, the samarium-iron-nitrogen flexible bonded permanent magnet meets the latest ROHS2.0 standard authentication standard and has the condition of earning foreign exchange by export; the blank of the high-fluidity area of the injection-molded flexible samarium-iron-nitrogen magnet is filled, the upper limit of the service temperature of the conventional flexible bonded magnet is improved, the service temperature is improved to 120 ℃ from 80 ℃, the use field is widened, and the stability and the reliability of the flexible samarium-iron-nitrogen magnet are improved.

In a second aspect, a method for preparing a high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding comprises the following steps:

s1: two-stage mixing plasticizing treatment: weighing the components according to the corresponding weight parts, putting the components into an internal mixer for mixing and plasticizing by a one-stage method, wherein the mixing temperature of the internal mixer is 150-; rolling the obtained banburying material on a rolling mill at the roll temperature of 140-;

s2: rolling treatment: rolling the obtained banburying material on a rolling mill at the roll temperature of 120 ℃ and 130 ℃ until the banburying material is rolled into a plate-shaped material with the thickness of 3-3.5mm,

s3: cutting into granules and injection molding: cutting the obtained plate-shaped material into particles with the size of 3-3.5mm multiplied by 3-3.5mm, and then molding on an injection machine at the injection temperature of 170-190 ℃.

The effect of the second aspect is the same as that of the first aspect, and therefore, the description thereof is omitted.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

In the drawings:

FIG. 1 is a schematic flow diagram of a method for making a high-fluidity samarium-iron-nitrogen flexible bonded permanent magnet for injection molding.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

For better understanding of the above technical solutions, the following detailed descriptions will be provided in conjunction with the drawings and the detailed description of the present invention.