JPS60156752A - Magnetic material composition having high fluidity - Google Patents

Abstract

PURPOSE:A composition providing a resin magnet having high fluidity, improved molding properties and mechanical properties, obtained by blending a polyamide copolymer containing laurolactam, etc. with a plasticizer and a stabilizer to give a blend, mixing the blend with magnetic material powder. CONSTITUTION:5-30wt% polyamide resin composition consisting of 100pts.wt. comprising a polyamide copolymer containing 10-98wt%, preferably 70-95wt% laurolactam, 12-omegaaminododecanoic acid and/or 11-omegaaminoundecanoic acid, having 1.20-1.80, preferably 1.30-1.60 relative viscosity, 1-30pts.wt. plasticizer, and 0.1-2.0pts.wt. stabilizer is blended with 95-70wt% magnetic material powder. A sulfonamide or an oxybenzoic ester is preferable as the plasticizer. Magnetic material powder having 0.5-10mu, preferably 1-5mu, is used as the magnetic material powder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic composition having good fluidity, good moldability, high magnetic properties, and good mechanical properties.

polyethylene, chlorinated polyethylene, polyvinyl chloride,
Injection molding by mixing magnetic powder into synthetic rubber, nylon, polypropylene, or ethylene-vinyl acetate copolymer, etc.
Alternatively, it is well known that extrusion molded products can be used as plastic magnets.

It is also well known to mix magnetic powder into natural rubber or synthetic rubber and produce rubber magnets by hot rolling, extrusion molding, or the like.

In order to improve the magnetic properties of such plastic magnets or rubber magnets, it is necessary to increase the content of magnetic powder and to orient the magnetic powder in a certain direction to provide anisotropy. . However, increasing the content of magnetic powder causes problems in that the mechanical properties of the molded product deteriorate and moldability becomes extremely difficult.

Furthermore, when ethylene-vinyl acetate copolymer, polyethylene, polypropylene, etc. are used together with ferrite as a magnetic composition, the heat resistance is insufficient, and deformation phenomenon is observed when left at temperatures of 100°C or higher. Moreover, the impact strength is also weak.

Furthermore, when polyamide was used in the same manner, it had good heat resistance during use but insufficient impact resistance, and there were also problems in magnetization. □ Solve the above-mentioned drawbacks, points, and problems of the present invention Cicada Plastic, Techino, Kusuma: Gunenoto, and □ Magnetic properties'? ;
The present invention provides a resin magnet that has good heat resistance, good mechanical properties, and excellent moldability.

That is, the present invention provides lauric lactam, 12-ω-aminododecanoic acid and/or 11-ω-aminoundecanoic acid.
100 parts by weight of a polyamide copolymer containing 0 to 98 parts by weight and having a relative viscosity of 1.20 to 180, 1.30 parts by weight of a plasticizer, and 0.1 to 2 parts by weight of a stabilizer.
This relates to a polyamide resin composition consisting of 0 parts by weight of 5 to 30 parts by weight and a hereditary magnetic resin composition of 70 to 95 parts by weight of magnetic powder.

The magnetic resin composition of the present invention will be explained in detail below.

The magnetic powder used in the present invention is usually an oxide of an iron group element (molecular formula: MFe2O4, M is iron oxide or an iron group element), which is commonly called ferrite in the industry.
For example, Mn-ferrite 1. Ni-
Ferrite, zn-ferrite, and solid solutions of these, Mn-Zn ferrite, Mn'LZn-'Ft
, Fe7 ferrite-Zn ferrite, or Co-F
e7 elite, Ba-7 ela, (To 1, Sr 7 elite, Mn -Mg -A I-based ferrite 1.Cr, -
There are ferrites, etc. Furthermore, examples include those in which various characteristics are added by adding trace amounts of oxides of various elements to these '0□te:elites.

RFe containing rare earth elements other than iron group elements
O3 (R is Tm, Lu, Yb, Er, Ho,
Examples include rare earth orthoferrites such as rare earth elements such as YlNdlSm and Eu.

"!"*#:"Ir:"*Ma; Magnetic material I material consisting of a combination of iron □ group element □ elementary oxide □ is also mentioned.

The particle size of the magnetic integrated powder is preferably 0.5 to 10μ.
<Orientation and magnetic properties during injection molding□Final manufacturing process□
Considering the above, 175-μ is preferable from a viewpoint. 6. Magnetic powder in the magnetic resin composition of the present invention. Mixed amount U70~95. t%Aachi・□・Pa, 8
．． ~95Wt4 is a preferable amount of mixing. If the amount is less than 7Qwt%, the magnetic performance will not be sufficient, and if it exceeds 95wt%, there will be a significant deterioration in moldability.

The polyamide copolymer used in the composition of the present invention preferably contains laurin lactam, 12-ω-aminododecanoic acid and/or 11-ω-aminoundecanoic acid in a weight range of 10 to 98% by weight, preferably 30 to 95% by weight. It's probably 70 hereditary.
It is a nylon copolymer having a relative viscosity of 1.20 to 1.80, preferably 1.30 to 1.60. The copolymerization component is a lactam or ω-aminocarboxylic acid having 6 to 13 carbon atoms, or a condensate of an alkylene dicarboxylic acid having 6 to 13 carbon atoms and an alkylene diamine having 6 to 13 carbon atoms.

Lactams or ω-aminocarboxylic acids having 6 to 13 carbon atoms include caprolactam and capryllactam, and condensates of alkylene dicarboxylic acids having 6 to 13 carbon atoms and alkylene diamines having 6 to 13 carbon atoms include 1
．． Hexamethylenediamine adipate, hexamethylenediamine sebacate, or a salt of the above-mentioned alkyl 1/lene dicarboxylic acid and 1°11-undecanediamine can be used.

lactam, or ωω-aminocarboxylic acid such as laurinlactam (12-ω-aminocarboxylic acid) or 11
When one of -ω-aminoundecanoic acids is used as one component, the other component can also be used as a copolymerizable monomer.

Moreover, the above-mentioned polymer of the present invention may be a copolymer of two or more elements. -"" □: Coporia M2 with a relative viscosity lower than 1.1 is weak against impact, and those with a relative viscosity exceeding 2.2 are weak.
□The fluidity of the resin during melting becomes significantly worse. :
Plasticizers used in the composition of the present invention include sulfonamides which have good compatibility with polyamide. Oxybenzoic acids and esters are preferred.

Ordinary non-ester plasticizers have poor compatibility with polyamides and are not suitable for mixing with polyamides. N-alkyltoluenesulfone 7 Mido, N-functional compound P-toluenesulfonamide, N-ethyl-〇.

Sulfonates such as P-toluenesulfonamide, N-butylbenzenesulfonamide 1-', and N-chlorohexyltoluenesulfonamide are preferably used. 100 parts of copolyaminyl-' (and 1 to 35 parts of plasticizer alone or in combination of two or more kinds, preferably 5 to 35 parts)
There are 35 copies. When the amount of plasticizer blended is less than 1 part per 100 parts of copolyamide, no plasticizing effect is observed;
If the amount of plasticizer exceeds 135 parts per 100 parts of copolyamide, precipitation of the plasticizer occurs.

Stabilizers include metal soaps, lead stabilizers, organic tin stabilizers, epoxy compounds, bisphenol stabilizers, and phosphite stabilizers, and these can be used alone or in combination.
The two can be used in a mixed form. Any stabilizer compatible with the copolyamide may be used. For 100 parts of copolyamide, 0.1 to 20 parts of stabilizer or two or more stabilizers, preferably 0.5 to 2 parts of stabilizer.
．． It is better to use 0 copies. If the amount of stabilizer added is less than 0.1 part per 100 parts of copolyamide, the stabilizing effect will be too weak, and if the amount added is more than 2.0 parts, there will be no significant difference in the stabilizing effect, but the price will be lower. be disadvantageous to

2) The following properties can be obtained by appropriately blending the above-mentioned copolyamide, plasticizer, and stabilizer and using them as a binder resin for a plastic magnet.

(2) Frictional wear between the magnetic powder and the resin during cross-wire reduction is reduced, and when injection molding is performed while applying an external magnetic field, the orientation of the magnetic powder becomes easier and the magnetic properties are improved.

2) When performing kneading, extrusion, and injection molding, the fluidity of the mixture becomes high, and molding can be performed even if it contains a large amount of magnetic powder.

3) Friction and wear on the surfaces of the molding machine and screener are reduced, making it possible to reduce the amount of impurities mixed into the molded product.

Also, the life of the device can be extended.

The composition of the present invention is produced by melt-mixing a magnetic powder, a polyamide polymer, and a plasticizer/stabilizer, usually using a twin-screw extruder.

Also, kneading may be carried out using a kneader. It is also possible to use a small amount of lubricant at this time.

Specifically, granules or powders of magnetic powder and polyamide polymer, premixed with plasticizers and stabilizers, or granules of polyamide copolymer with magnetic powder and plasticizers and stabilizers mixed in advance. Alternatively, a method of mixing powdered materials, charging the mixture into an extruder hopper, heating and melting the mixture and granulating it. Alternatively, the premixed material is kneaded in a kneader, and when the mixture is completed, the material discharged from the discharge port is granulated by cutting or pulverization, or by using an extruder, the polyamide copolymer, plasticizer, and stabilizer are mixed. Charge the powder into a part of the hopper, heat and melt it, and add the magnetic powder through the hole provided in the middle part of the cylinder of the extruder 1-7.
There is a way to mix it up. At this time, a mixture of a plasticizer and a stabilizer may be heated and kneaded in advance in an extruder or kneader to copolymerized polyamyl, and then granulated or a powder thereof may be used.

A plastic magnet can be obtained by further molding the bell/mouth thus obtained by injection molding or the like while applying a magnetic field. Alternatively, instead of such two-stage molding, a mixture of magnetic powder and copolyamide, a plasticizer, and a stabilizer, or a polyamide copolymer and magnetic powder that have been heated and kneaded with a plasticizer and stabilizer in advance can be used in an injection molding machine. Molded products can also be obtained at one time by charging.

The nylon copolymer used in the present invention contains 0.5% m-
It is preferable that the relative viscosity in cresol solution is 1.2 to 18. Copolymerized polyamides have long assimilation times, difficult mold release properties, and are susceptible to deformation, so they are rarely used as injection molding materials. However, materials with plasticizers added thereto, or with plasticizers and stabilizers added thereto, have not been used for these purposes. The greatest feature of the present invention is to use this combination as a binder for magnetic powder, a combination that is rarely used for molding materials (... is also possible.

In other words, the material made of the combination of nylon copolymer and plasticizer used in the present invention is rarely used alone as a molding material, but when used as a binder for magnetic materials according to the present invention, its fluidity can be improved. The good properties of the material have an advantageous effect on the good moldability as a plastic magnet material, and the problems that were considered as a single product have been resolved, and fully satisfactory mechanical properties can be obtained.

Therefore, when obtaining a plastic magnet molded article using the magnetic resin composition of the present invention, a wide range of molding temperatures can be selected even if the magnetic material content is the same. Additionally, improved fluidity allows molding at lower temperatures, extending machine life and saving power consumption.

As described above, according to the magnetic resin composition of the present invention, it is possible to obtain a plastic magnet that has good magnetic properties, no decrease in strength, and good moldability.

Next, the present invention will be explained with reference to examples.

EXAMPLE - The blending ratio as shown in Table 1 is as follows: the binder is a copolymer with a copolymerization weight of JtsO/2oo, butylbenzenesulfonamide and parahydroxyoctylbenzoate are used as plasticizers, and Irganox is used as a stabilizer. The test was conducted using 1010. Table 1 shows the properties of binder resins obtained with the combinations shown in Table 1.
Each plastic binder shown in No. 2 is mixed with magnetic powder prepared in advance so as to have a predetermined magnetic powder concentration. The magnetic powder used at this time is strontium ferrite and has an average particle size of 1.24μ.

In this experiment, the amount of magnetic powder was 88 wt% and 90%.

I made it so that i←44. .

Next, mix these magnetic powders and sample resin.
It was weighed to have a volume of cc, and the crosstalk torque at the time of crosstalk was investigated. Rheocord is used to investigate crosstalk and torque.

Using Type M (Hoake, Inc.), the measurement temperature was 270°C and the rotation speed was 5 Qr.
15 minutes after the start of kneading (7) Luk was observed at pm.

The results of the kneading torque thus obtained were as shown in Table 3. The four-line mixture obtained at this time was pulverized and used as a sample for measuring fluidity. ASTM D12 is an indicator of fluidity as a plastic magnet molding material.
The method of MeltIndex measurement according to No. 38 was adopted. MeltIndex for measuring fluidity
Measurements were made using r. Measurement conditions are 280℃
A load of 10 kg was adopted. The results were as shown in Table 4.

The above mixture of magnetic powder and resin was extruded using a 25mm extruder at a cylinder temperature of 270'C. By repeating extrusion molding twice, more uniform cross-wires were expected. The thus extruded product was canted to a length of 1 to 4 ys* to obtain a sample for molding.

In order to examine the mechanical properties of the magnetic resin composition, test pieces were prepared using the method described below.

That is, the molding sample obtained as described above was used at Kawaguchi Iron Works (
Co., Ltd.) KY-1QQS injection molding machine to test the
, molding was carried out. The molding conditions are cylinder temperature 28
0℃, nozzle temperature 270℃, injection pressure・i, 300#/
mG and a mold temperature of 85°C were used. The results of measuring the mechanical properties at that time were as shown in Table 5.

The results of Tables 4 and 5 are clearer than the results.
Even with the magnetic powder content, fluidity and moldability vary greatly depending on the blending ratio of binder/resin and plasticizer.

If the magnetic powder content, plasticizer content, and content are the same, the relative viscosity of the 0.5% meta-cresol solution of the binder resin is
Use of the lower part gives better moldability.

As long as the magnetic powder content and the binder resin content are the same, the plasticizer added will give good moldability regardless of the type of plasticizer.

By using a binder, a copolyamide with a low relative change in a 0.5% metacresol solution of a resin, a plasticizer, and a stabilizer, a plastic mag with good moldability can be obtained.

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Claims (1)

[Claims] Polyamide 1, a hereditary polyamide copolymer containing 10 to 98% by weight of laurin lactam, 12-ω-aminododecanoic acid and/or 11-ω-aminoundecanoic acid, and having a relative viscosity of 1°20 to 1.80; 00 parts by weight, 1 to 30 parts by weight of a plasticizer, and 0.1 to 2.0 parts by weight of a stabilizer, a resin composition of 5 to 30 parts by weight, a hereditary body powder of 95 to 70 parts by weight, and a hereditary magnetism. body composition.