Magnetic core coated with tin free electrodeposition coatings

• US 5,658,660 A
• Filed: 11/14/1995
• Issued: 08/19/1997
• Est. Priority Date: 11/15/1994
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hasegawa, Makoto, Nakamura, Kazuya, Teshima, Hiroyoshi, Uda, Shigenori
• Primary Examiner(s): Resan, Stevan A.
• Application Number:
  US08/557,949
• Time in Patent Office: 644 Days
• Field of Search: 428/334, 428/416, 428/692, 428/900, 336/219, 335/297, 310/45
• US Class Current: 428/334
• CPC Class Codes: H01F 3/00 Cores, Yokes, or armatures magnetic materials H01F1/00; permanent magnets H01F7/02
• CPC Class Codes: H02K 1/04 characterised by the material used for insulating the magnetic circuit or parts thereof
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/11 Magnetic recording head
• CPC Class Codes: Y10T 428/263 Coating layer not in excess of 5 mils thick or equivalent
• CPC Class Codes: Y10T 428/31522 Next to metal

Abstract

In order to prevent clouding of a hard disc and a polygon mirror, a tin-free electrodepositing coating composition is used as an insulating coated film of a motor for driving the hard disc and polygon mirror.

Claims

1. A magnetic core coated with a film of a cationic electrodeposition coating composition comprising cationic-electrodepositable resins and blocked isocyanates without tin.

2. The magnetic core of claim 1, wherein said cationic electrodeposition coating composition is coated on an iron core of a motor.

3. The magnetic core of claim 1, wherein said cationic electrodeposition coating composition comprises a cationic epoxy electrodeposition coating composition.

4. The magnetic core of claim 3, wherein said cationic epoxy electrodeposition coating composition contains a cationic polymer obtained from a reaction product of polyglycidyl ether of a polyphenol having an average molecular weight of 300 to 3500 or a derivative thereof and a secondary amine, and a blocked isocyanate.

5. The magnetic core of claim 1, wherein said cationic electrodeposition coating composition is coated on a multi-layer core.

6. The magnetic core of claim 1, wherein said film of a cationic electrodeposition coating composition has a thickness of 20 to 100 micrometers.

7. A spindle motor of a hard disc drive comprising the magnetic core of claim 1.

8. A motor of a polygon mirror driving device comprising the magnetic core of claim 1.

9. A transformer comprising the magnetic core of claim 1.