JPS60136207A - Forming material for resin magnet and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate injection molding and to increase magnetic characteristics by adding and mixing a plasticizer in synthetic resin in advance and then adding ferromagnetic powder to mix it in said resin. CONSTITUTION:A plasticizer is added and mixed in synthetic resin and ferromagnetic powder is then added and mixed. The synthetic resin is of pellet or powder state such as of polyamide group, polyolefin group, polyvinyl chloride, etc. The placticizer is normal butyl benzene sulfon amide expressed by a formula C6H5SO2NH(CH2)3CH3 or the like. Also the ferromagnetic powder is ferrite expressed by a formula MO.nFe2O3 (wherein M is Sr or Ba, n=5-6), samarium compound expressed a formula RnCOm (wherein R is Sm, n=1 or 2, n=5 or 17) and so on.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molding material for a resin magnet that contains a large amount of magnetic powder and provides a highly oriented resin magnet molded product, and a method for producing the same.

BACKGROUND ART Conventionally, as a resin magnet molding material, a mixed material obtained by mixing and kneading a ferromagnetic It 2 material and a synthetic resin such as polyamide, polypropylene, or polyvinyl chloride has been used for injection molding. In order to improve the magnetic properties of a molded article, it is necessary to fill the molded article with a high concentration of ferromagnetic powder and to make the ferromagnetic powder highly oriented.

However, when ferromagnetic powder is filled in a high concentration, the melt viscosity of the molded material increases, leading to problems such as injection molding being impossible or insufficient orientation during magnetic field molding, resulting in molded products with high magnetic properties. was not obtained.

An object of the present invention is to provide a molding material for a resin magnet that contains a large amount of ferromagnetic powder and is capable of forming a highly oriented resin magnet molded product, and a method for manufacturing the same.

That is, the molding material of the present invention is characterized in that it contains a synthetic resin as a matrix mixed with ferromagnetic powder, and a plasticizer is added thereto.

In this molding material, since the melt viscosity is reduced by the action of a plasticizer, injection molding can be easily performed, and the rotational movement of the ferromagnetic powder in a magnetic field becomes easy, resulting in a high orientation rate. This means that even with a molding material containing a high concentration of ferromagnetic powder, it is possible to easily mold a resin magnet molded product in which the ferromagnetic powder is highly oriented.

The molding material of the present invention can also be obtained by simultaneously mixing and kneading a synthetic resin, ferromagnetic powder, and plasticizer (ζ), but the following manufacturing method can further improve the characteristics of resin magnet molded products. I can do it.

That is, this is a manufacturing method in which a plasticizer is added and mixed in advance to a synthetic resin, and then an elastomagnetic powder is added and mixed and kneaded. The synthetic resin is in the form of pellets or powder, such as polyamide, polyolefin, or polyvinyl chloride. The plasticizer has the formula c, ■, s at NH(cHt) ICEI
Normal butylbenzenesulfonamide (
(referred to as I lower N B B SA) etc. Further, the ferromagnetic powder is a ferrite represented by the formula MO・n Fe, O+ (M is 3r or Ba, TI=5 to 6), a ferrite represented by the formula R
It is a samarium compound represented by nC0m (R is 3m%, n=1 or 2, m=s or 17), and the like.

Next, the present invention will be explained with examples.

Example I Melt viscosity: 2000 Boise (250°C, 100SeC) 5 parts by weight of NBBSA was added to 100 parts by weight of one 6-nylon powder, mixed in a super mixer, and this mixture was extruded while maintaining the melting point of 6-nylon or higher. They were kneaded in a machine to form pellets. 11 parts by weight of these pellets were filled with 89 parts by weight of strontium ferrite, mixed in a super mixer, and mixed and kneaded in a twin-screw extruder kept above the melting point of nylon 6 to form a resin magnet. A molding material was obtained.

The above-mentioned molding material was injection molded in a magnetic field to obtain a specimen (φ20×H10) for measuring magnetic properties.

Similarly, specimen for measuring mechanical strength (T3XW25XL60)
I got it. The magnetic properties, orientation rate, and mechanical strength of the sample 1ζ obtained were measured and are shown in Table 1 along with the melt viscosity of the molding material.

Example 2 9 parts by weight of NBBSA-added pellets in Example 11,
A molding material was obtained by straining in the same manner as in Example 1 except that the ferromagnetic powders were Sm and CO++. Table 1 shows the results of the same evaluation.

Comparative Example 1 A molding material was obtained in the same manner as in Example 1 except that NBBSA was not added to the 6 nylon powder. Table 1 shows the results of the same evaluation.

Comparative Example 2 A molding material was obtained in the same manner as in Example 2 except that NBBSA was not added to the nylon 6 powder. Table 1 shows the results of the same evaluation.

Example 3 6 nylon powder in Example 11 - 105 parts by weight,
0.5 parts by weight of NBBSA and 89 parts by weight of strontium ferrite were simultaneously mixed in a super mixer and kneaded in a twin screw extruder maintained above the melting point of nylon 6 to obtain a molding material for a resin magnet. This was evaluated in the same manner as in Example 1, and the results are shown in Table 1.

As shown in Table 1, the molding material for resin magnets of the present invention has a very low viscosity, making injection molding easy, and the ferromagnetic powder is easily oriented in a magnetic field, increasing the orientation rate. As a result, a molded product with high magnetic properties can be obtained, and the mechanical strength of the molded product is sufficiently maintained. Furthermore, as is clear from the comparison between Example 1 and Example 3, according to the production method of the present invention, it is possible to obtain a molding material that provides a resin magnet molded product with even better characteristics, and its industrial value is It is extremely large.

patent applicant

Claims (1)

[Scope of Claims] 1. A molding material for a resin magnet, characterized in that a plasticizer is added to a synthetic resin matrix mixed with ferromagnetic powder. 2. A molding material for a resin magnet, which is a mixture of synthetic resin as a matrix and ferromagnetic powder, which is characterized in that a plasticizer is added to the synthetic resin in advance and mixed, and then ferromagnetic powder is added and mixed and kneaded. Manufacturing method.