JPS62107953A - Polishing tape - Google Patents

Abstract

PURPOSE:To prevent the slipping-off of polishing particles from a polishing coated film, maintaining the high grinding faculty, by covering the surface of the polishing particle projecting from the surface of the polishing coated film by binder and increasing the contact area between the polishing particle and the binder. CONSTITUTION:When the tape sliding surface of a magnetic head is polished, a polishing tape is traveled at a constant speed, and a coated layer 2 is slided onto the magnetic head. At this time, the tape sliding surface of the magnetic head is polished smoothly by the hard polishing agent 4 dispersed in the coated layer 2. In order to increase the grinding faculty, the polishing particle 4 having the particle size larger than the thickness of the coated layer 2 is used as polishing agent. Therefore, though the upper part of the polishing particle 4 projects from the surface of the coated layer 2, this part is covered with a thin film 5 made of binding agent, and the contact area between the polishing particle and the binding agent is increased. Therefore, the polishing particle is firmly bonded with the coated layer 2, and hardly slipped off from the coated layer 2 even in the polishing of the magnetic head.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an abrasive tape used for precision polishing of magnetic heads of magnetic recording and reproducing devices, and is particularly suitable for smoothing magnetic heads for video or high-end audio. This invention relates to the polishing tape used.

(Prior Art) Magnetic heads for video or high-end audio equipment require particularly smooth tape sliding surfaces, so when manufacturing magnetic heads, abrasive tape is used to make the tape sliding surfaces smooth. Such abrasive tape is made by coating an abrasive film containing an abrasive and a binder on a flexible non-magnetic support, so it adapts to the curved shape of the tape contact surface of the magnetic head. This surface can be precisely polished.

By the way, such abrasive tapes require higher abrasive ability than cleaning tapes, etc., so generally M
For polishing, abrasive particles with a particle size larger than the thickness of the abrasive coating are used.

However, in this case, the upper part of the abrasive particle is arranged so as to protrude from the surface of the abrasive coating film, and the ratio of the area where the abrasive particle is in contact with the binder to the surface area of the abrasive particle is small, so that the abrasive particle and fA@ There was a problem in that the bonding force of the coating film became weak, and the abrasive particles easily peeled off from the abrasive coating film during magnetic head polishing.

(Object of the Invention) The present invention has been made to solve the above problems, and is an object of the present invention to prevent detachment of abrasive particles from the abrasive coating film while maintaining high grinding ability when polishing an object to be polished. The object of the present invention is to provide an abrasive tape that can be obtained.

(Structure of the Invention) The abrasive tape of the present invention is characterized in that the surface of the abrasive particles protruding from the surface of the abrasive coating film is covered with a film of a binder to increase the contact area between the abrasive particles and the binder. It is something.

Here, the abrasive coating film is one in which abrasive particles are arranged so as to protrude from the surface of the coating film.

Furthermore, the abrasive tape mentioned above broadly includes not only so-called tape-shaped polishing tapes but also disc-shaped or sheet-shaped polishing tapes.

(Effects of the Invention) According to the abrasive tape of the present invention, the ratio of the contact area between the abrasive particles and the binder to the total surface area of the abrasive particles is increased to strongly bond the abrasive particles to the abrasive coating film. When polishing a magnetic head with this polishing tape, it is possible to prevent the polishing particles from peeling off and detaching from the polishing coating.

This significantly increases the durability of the abrasive tape.

(Embodiments) Hereinafter, embodiments of the present invention will be described using the drawings.

As shown in FIG. 1, the polishing tape according to the embodiment of the present invention is composed of a flexible non-magnetic support 1 and a coating layer 2 formed on the support 1. The coating layer 2 is formed by kneading an abrasive, a binder, and a lubricant.

Here, the abrasive is granular CrzCh or A9, with an average particle size of 3 to 20μ and a large Mohs hardness.
03, etc., and the binder is vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer,
Nitrocellulose, polyamide.

Consists of polyamine, epoxy resin, etc. In addition, the above i1
! For example, silicone oil is used as the lubricant.

When polishing the tape sliding surface of the magnetic head 3, the polishing tape is run at a constant speed from one side of the reel (not shown) placed at two positions sandwiching the magnetic head 3. The coating layer 2 is made to slide on the magnetic head 3. At this time, the hard abrasive agent 4 dispersed in the coating layer 2 polishes the tape area of the magnetic head to make it smooth.

By the way, in order to obtain a large grinding ability with abrasive tape, abrasive particles 4 with a particle size larger than the thickness of the coating layer 2 are used as an abrasive.
Use. As a result, as shown in FIG. 2, the upper part of the abrasive particles 4 protrudes from the surface of the coating layer 2, so that the ratio of the contact area between the abrasive particles and the binder to the total surface area of the abrasive particles 4 becomes small, making it difficult to polish the magnetic head. When this abrasive particle is applied A2
There was a situation where it came off. Therefore, in the abrasive tape of the present invention, the parts of the abrasive particles protruding from the coating layer 2 are coated with a thin film 5 of a binder to increase the contact area between the abrasive particles and the binder.

In FIG. 2, this thin film 5 is formed to have a thickness of about 3 μm. This thin film 5 can be formed by, for example, the following method (1).
, (2>).

◎Method (1) Apply an organic solvent (butyl acetate, methyl ethyl ketone, toluene, etc.) to the surface of coating layer 2 to swell and dissolve the surface of layer 2, and then slowly dry to form the thin film 5. form.

◎Method (2) The binder and solution are again applied to the surface of the coating layer 2 to form the thin film 5 described above.

Due to the presence of this thin film 5, the abrasive particles are strongly bonded to the coating layer 2, and are not easily detached from the coating layer 2 even during polishing of the magnetic head.

For example, polyethylene terephthalate (PET) or polyethylene naphthalate is used as the non-magnetic support mentioned above.

Next, an example will be given and explained.

Example 1 Polyethylene terephthalate (PET) with a thickness of 38 μm
After coating a first liquid mixture having the following coating composition on the support to a thickness of about 8 μm, a second liquid mixture having the following coating composition is applied onto this coating layer.
Polishing tape 1 was prepared by applying the mixed solution to a thickness of approximately 3 μm (dry thickness). Note that this example is based on Japanese Patent Application Laid-open No. 53-1020.
This is similar to the Sambuno α41 disclosed in Publication No. 17. Moreover, in the following description, all parts indicate parts by weight.

◎First mixed liquid composition/granular CrzO3...300 parts <average particle size 1
0um, Mohs hardness 6) Vinyl chloride-vinylidene chloride copolymer...46.4 parts (copolymerization ratio = 7:3. Degree of polymerization = 400>) Epoxy resin
...28.3 parts (reaction product of bisphenol A and epichlorohydrin, molecular weight = 900, epoxy equivalent = 460-5201, hydroxyl group content = 0.29%,
Chell Orl Go, Epi D-To 100
1)・Silicone oil・・・・・・
・1.0 parts (dimethylpolysiloxane) ・Isocyanate compound ・・・・・・5.
6 parts (7 parts of the reaction product of 3 moles of 2,4-tolylene diisocyanate compound and 1 mole of trimethylolpropane)
5wt% ethyl acetate solution BaVerA, G, [
) esmodur l -, 75) Butyl acetate
...800 parts ◎ Second mixed liquid composition Vinyl chloride-vinylidene chloride copolymer...46.4
parts (copolymerization ratio -7:32 degree of polymerization -400)・Epoxy resin...28.3 parts (reaction product of bisphenol A and epichlorohydrin, molecular weight -900, epoxy equivalent -460 to 520, water! !!
Group content = 0.29%, Shell Oil C
o, Epicote 1001)・Isocyanate compound...5.6 parts (3 moles of 2.4-
75 wt% ethyl acetate solution of reaction product of tolylene diisocyanate compound and 1 mol of trimethylolpropane BaVer A, G, [)esmodur L
-75>・Butyl acetate ・・・・
...800 parts Example 2 After applying the first liquid mixture onto a support in the same manner as in Example 1 above, this applied layer was treated with butyl acetate and dried to prepare polishing tape 2.

Comparative Example A polishing tape 3 was prepared in the same manner as in Example 1 except that the second mixed solution was not applied on the coating layer after the first mixed solution was applied.

For each of the abrasive tapes of Example 1.2 and Comparative Example above, the number of abrasive particles that fell off after grinding the magnetic head was investigated. The results are shown in the table below as relative values.

In the above table, the number of fallen abrasive particles is determined by observing the surface of the abrasive tape after grinding the ferrite head with an electron microscope (5,000 times magnification) and counting the number of dents that are traces of the abrasive particles that have fallen off.

As is clear from the above table, Example 1.2 can extremely reduce the amount of abrasive particles falling off the tape surface.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an abrasive tape according to an embodiment of the present invention during polishing of a magnetic head, and FIG. 2 is an enlarged sectional view of the abrasive tape of FIG. 1. 1... Nonmagnetic support (PET) 2... Coating layer 3... Magnetic head 4.
...Abrasive (abrasive particles) 5...Tl! (Thin film) Figure 2 (Voluntary) Procedure amendment mouth To the Commissioner of the Patent Office October 1986
Patent Application No. 60-246065 dated March 3rd, 2003, Title of the invention: Abrasive tape 3, Relationship with the case of the person making the amendment Person of the patent applicant Location: 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name:
Fuji Photo Film Co., Ltd. 4, Agent: 7th floor, Uraya Building, 5-2-1 Roppongi, Minato-ku, Tokyo (7318) Patent attorney: Yanagi 1) Seishi (and 1 other person) 5
, Date of amendment order: None 6, Number of inventions increased by amendment: None 8, Contents of amendment 1) The scope of claims will be amended as shown in the attached sheet. 2) Insert rsi CJ after page 5, line 3, rcrz03J of the specification. 2) Insert "isocyanate compound" after "epoxy resin" in line 7 of the same page. 3) After "forming the thin film 5" on page 6, line 18, "the binder used for the thin film 5 may of course be different from the binder used for the coating layer." correct. Claims (1) An abrasive coating film made of abrasive particles dispersed in a binder is applied onto a flexible non-magnetic support, and the abrasive particles protruding from the surface of the abrasive coating film are coated on a flexible non-magnetic support. An abrasive tape with a bonding agent coating formed on its surface. (2) The polishing! The average particle diameter of l is 3 to 20 μm, and the thickness of the coating is 0.5 to 3 μm! 'The abrasive tape described in box 1. % formula % 2. Name of the invention Abrasive tape 3. Relationship with the person making the amendment Patent applicant Location 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name
Fuji Photo Film Co., Ltd. 4, Agent: 5-2-1 Roppongi, Minato-ku, Tokyo, January 8, 1986 (Delivery date: January 28, 1986). 6. Number of inventions increased by amendment None 7. Subject of amendment Drawings ・S+;
, 'i''' (8. Contents of amendment 1) Figure 1 of the drawings is amended as attached. (No change in content)

Claims (2)

[Claims] (1) An abrasive coating film made of abrasive particles dispersed in a binder is applied onto a flexible non-magnetic support, and the above-mentioned bonding is applied to the surface of the abrasive particles protruding from the surface of the abrasive coating film. An abrasive tape formed with a coating of agent. (2) the average particle diameter of the polishing layer is 3 to 20 μm,
The polishing tape according to claim 1, wherein the thickness of the coating is 0.5 to 3 μm.