JPH0425003A - Rare-earth and iron system resin coupling type magnet - Google Patents

Abstract

PURPOSE:To contrive to cut off air, hot-air, solvents, chemicals or the like and to prevent from oxidizing by a method wherein organic resin is added to a magnet powder, of which a fundamental composition comprises a rare-earth metal, iron, and boron, and which is manufactured by a rapid solidification method, to mold a magnet surface on which on organic resin film having a specific thickness are electrodeposited. CONSTITUTION:Organic resin is added to a magnet powder, of which a fundamental composition comprises a rare-earth metal, iron, and boron, and which is manufactured by a rapid solidification method, to mold a magnet surface on which an organic resin film of 5 to 50mum is electrodeposited. Electrodepositing material to be used is one in which resin having an amino group (-NH2) is neutralized and by an acid such as a lower organic acid or the like in the cation type electrodepositing, and the resin and pigment are charged in the water and electrodeposited on an object to be cooled which is the negative pole, thereby depositing a film to coat. Then, a portion of iron is replaced with one or more transition metals such as Al, CO, and Nb.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention involves adding an organic resin to a magnetic powder whose basic composition is rare earth metal, iron, and poron and produced by an ultra-quenching method. Electrodeposition coating on the magnet surface for anti-rust power.
Concerning high-performance rare earth and iron-based resin bonded magnets with excellent dust resistance.

[Prior Art] Rare earth magnets, which are effective in reducing size and increasing efficiency, are broadly classified into rare earth metal, cobalt-based, and rare earth metal iron-based magnets based on their composition.

Rare earth and iron-based magnets have Nd (neodymium) and iron boron as their main components, and were announced by GM (General Motors) and Sumikata Special Metals Co., Ltd. in 1983.
Among these, the magnet announced by GM was manufactured by molding ribbon-shaped powder obtained by an ultra-quenching method.

[Problem to be solved by invention C] However, rare earth and iron-based resin bonded magnets are extremely prone to rust, and when incorporated into motors, speakers, relays, etc., there is a problem in that the rust significantly reduces performance. Ta. In order to solve these conventional problems, the present invention aims to coat the surface of a magnet with an organic resin by electrodeposition to block air, heat, solvents, chemicals, etc. and prevent oxidation.

[Means for Solving the Problems 1] In order to solve the above problems, the rare earth and iron-based resin bonded magnet of the present invention is a magnet whose basic composition is a rare earth metal, iron, and poron, and which is manufactured by an ultra-quenching method. It is characterized in that an organic resin film of 5 to 50 μm is electrodeposited on the surface of a magnet formed by adding an organic resin to powder.

The electrodeposition coating material used in the present invention is made by neutralizing a resin having an amino group (-NH2) with an acid such as a lower organic acid to make it water-soluble through cationic electrodeposition coating, and the 161 fat and pigment are dissolved in water. It is highly charged and is electrodeposited on the object to be coated, which is the cathode, to deposit and coat the coating.

The coating thickness was set to be 1 μm or more since it is difficult to ensure reliability due to the occurrence of a non-uniform layer if the coating thickness is 1 μm or less.

If the thickness is 50 μm or more, the work time will be longer and the cost will be higher.
become. The basic composition of the rare earth magnet powder produced by the ultra-quenching method is 8 to 18%, 73 to 88%, and 4 to 9% in atomic ratio, and the rare earth metals are Y, La, etc. , Ce, Pr, Sm, Nd, Eu,
Gd, Tb, Dy, a single substance or a mixture of two or more types, and a part of iron replaced with one or more transition metals such as Ag, Co, Nb, etc., but the present invention applies to other compositions as well. This effect is not limited to a specific composition.

[Example 1] A magnet having an atomic ratio of N d +4F e 20CO + oB s was obtained by mixing an epoxy resin with a powder obtained by an ultra-quench cooling method, compression molding the mixture, and then thermosetting it. This magnet was electrodeposited with epoxy resin in various thicknesses.

Table 1 shows the state and performance after the salt spray 24H test.

No rust occurred when the film thickness was 5 μm or more. Also, no performance deterioration was observed. The effect of electrodeposition coating can be seen.

[Example 21 In addition, Table 2 shows the results of a dual-temperature test conducted on the Zamburu of Example 1 at 80°C x 90% RH〇-No rust observed under a microscope〇-No rust observed visually None - Rust occurred in several places × - Rust occurred throughout The above results show that the electrodeposition coating has excellent temperature resistance.

[Effects of the Invention] As described above, the present invention has a rare earth and iron-based resin bonded magnet with an electrodeposited coating, so it has excellent rust prevention properties, and when used in motors, speakers, sensors, etc. This has the effect of not only improving the stability of the magnetic flux in the magnetic circuit, but also improving its reliability.

Claims (2)

[Claims] (1) The basic composition is a rare earth metal, iron, and boron, and an organic resin is added to magnet powder manufactured by an ultra-quenching method, and an organic resin film of 1 to 50 μm is electrodeposited on the surface of the magnet. A rare earth and iron-based resin bonded magnet. (2) The rare earth/iron resin bonded magnet according to claim 1, wherein a part of the iron is replaced with a transition metal other than iron, such as cobalt.