JPS62224581A - Grinding tape - Google Patents

Abstract

PURPOSE:To utilize always a same grinding performance by forming a high viscosity silicone on a surface of a supporting body on which a grinding layer is not formed, thereby improving frictional condition between the supporting body and a tape running mechanism. CONSTITUTION:A grinding layer 2 containing abrasive 3, binder and additives is applied on a surface 1a of a flexible supporting body 1 of a grinding tape 1. High viscosity silicone exists on the other surface 1b of the tape so that friction between the other surface 1b and running mechanism is stabilized and that instability of friction coefficient during running of the tape can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polishing tape used for polishing magnetic heads and the like.

(Prior Art) Magnetic heads for video or high-end audio are polished using an abrasive tape. The head surface requires precision polishing, and generally the magnetic head is placed in a predetermined position.
An rIII polishing tape is run between two reels sandwiching this magnetic head to smooth the tape drive surface of the magnetic head. Such an abrasive tape consists of a flexible support, a fine particle abrasive, a binder,
The polished rN layer is formed by coating additives containing lubricants, etc., and because it is flexible, it adapts to the curved shape of the tape sliding surface (polished surface) of the magnetic head. Can be finished by polishing.

However, even polishing tapes with the same composition, which are supposed to have the same polishing ability, show variations in polishing performance. For example, there are differences in polishing performance depending on the loft of the tape, or between the beginning and end of the tape roll, etc., and the polishing performance of the polishing tape also varies depending on the usage environment such as dry g1. Differences occur in polishing performance.

With such polishing tapes that show variations in polishing performance, the yield of heads is poor, and it is necessary to reset the polishing conditions each time.As mentioned above, the rtl'f of magnetic heads that require precision polishing is 11! It is inconvenient for Therefore, there is a need for an abrasive tape that does not cause such inconveniences and has stable abrasive performance.

<Object of the Invention> The present invention is intended to meet the above-mentioned demands and provide a polishing tape having stable polishing performance.

(Structure of the Invention) The polishing tape according to the present invention is characterized in that high-viscosity silicone is present on the surface of the flexible support that is not coated with the polishing layer.

In other words, in an abrasive tape having an abrasive layer coated on one side of a support, the other side of the support, which is not coated with the abrasive layer, has a high viscosity when the abrasive tape runs. By the presence of silicone, this high viscosity silicone acts as a lubricant, allowing stable running of the polishing tape and stabilizing the polishing ability.

The high viscosity silicone may be present on the other surface of the support during use, and instead of being applied directly to the other surface, it may be added to the polishing layer during tape handling (when the tape is wound). The silicone may be transferred from the polishing layer to the back surface.

Note that the other side of the support is the side of the support on which the polishing layer is not formed, and means the so-called back side of the polishing tape.

(Embodiment) Hereinafter, the embodiment IIAra+ aspect of the present invention will be described in detail.

The polishing tape according to the present invention has a tape shape, and as partially shown in the drawing, includes a flexible support 1 and a flexible support 1.
The polishing layer 2 is coated on a portion 1a of the polishing layer 2. This polishing layer 2 is formed by kneading a polishing agent 3, a binder, etc.

When polishing the tape sliding surface of the magnetic head 4 with a wound polishing tape, the polishing tape is placed at two positions sandwiching the magnetic head 4, and the polishing tape is moved from one side of a wheel (not shown) to the other. is run at a constant speed, and the magnetic head 4 is made to apply the polishing layer 2 once. At this time, the hard particulate abrasive 3 protruding from the surface of the polishing M layer 2 polishes the tape 1 of the magnetic head 4 smoothly. The particle size of this abrasive 3 may be adjusted depending on the purpose.
Approximately 6μTrL to 1μmrL, 1μ7 for final finish
It is sufficient if the particle diameter deviates from about FL to 0.1 μTrL.

Further, the abrasive 3 is preferably a hard abrasive having a Mohs hardness of 6 or higher, more preferably a Mohs hardness of 8 or higher.

The binder for bonding the abrasive 3 is required to have a high retention force J3 and good dispersibility.

In order to perform precision polishing with a polishing tape containing such a hard abrasive, stable polishing ability is required when using the polishing tape. However, the polishing ability may vary depending on the loft of the tape despite having the same composition, or the polishing ability may differ depending on the tape's part, for example, the polishing ability may differ between the beginning and end of the tape. If a difference occurs, precision polishing becomes impossible. Such instability in the polishing ability is due to the difference between the other surface 1b of the support 1 and the tape traveling system etc. when the polishing tape is running. This occurs because the J friction coefficient becomes unstable, and the tension of the polishing tape in contact with the object to be polished is no longer constant, which adversely affects tape running.

For this reason, high viscosity silicone having a lubricating effect is provided on the other surface 1b of the support 1 of the polishing tape. Thereby, the friction between the other surface 1b and the running system etc. becomes stable, and the instability of the friction coefficient during running can be eliminated.

High viscosity silicone is polysiloxane, specifically linear or cyclic dimethylpolysiloxane,
Methylphenylpolysiloxane.

It is marketed as diphenylpolysiloxane, dialkylborisiloxane, and their derivatives (modified products).

The viscosity is 10,000 centestokes (cst) at 25°C.
) or more, preferably 50,000 hinch stokes (cst) or more, and more preferably 100,000 to 1 million centistokes (cs
t) is preferred. That is, a so-called starch syrup-like viscosity is preferable, and even if the viscosity is low, if it is kneaded into the polishing layer as an additive, it will have a high migration property in the polishing layer, etc., and will easily change depending on the environment, making it ineffective. Therefore, it needs to have a high viscosity.

This high viscosity silicone must be present on the other surface 1b of the rIFl tape-like support 1 during use. Its presence m may be 5000*/m or less on the support, and 0.
1 to 500 IIg/Td is preferable, and more preferably 1 to 1001
1117go is preferred. In addition, since it is only necessary that the polishing tape be present on the other side 1b when using the polishing tape, there is a method in which the high viscosity silicone is applied on the other side 1b and then slit in a bulk roll state in which the tape is not slit according to the prescribed J method during manufacturing. Alternatively, after slitting, high viscosity silicone may be applied to the other surface 1b.

Furthermore, a method of adding it as an additive to the polishing layer 2 is also possible. At that time, the amount added is 5 parts or less, preferably 1.0 parts or less, and more preferably 0.005 to 0.0 parts per 100 parts of the abrasive.
5 parts is preferred.

Further, it is preferable that the amount is 5 parts or less with respect to the total solid content ff of the polishing layer of 1100 parts. In this case, since the polishing tape is wound after manufacturing, the other surface 1b and the surface of the polishing S layer 2 are
They are tightly wound together. Therefore, since the high viscosity silicone kneaded into the polishing layer 2 has a property that it tends to stand out on the upper surface, the high viscosity silicone oozes out onto the surface of the polishing layer 2, and the other surface of the support that is in contact with the surface of the polishing layer 2. 1
It will be applied to b.

Therefore, by forming it in this way, the same effect as when directly applying it to the other surface 1b can be obtained.

A specific example of high viscosity silicone is KF96H-10
000,K F96H-500001K F96H-1
00000°K F 961-1-500000. K
F 96H-1000000<Shin-Etsu Chemical), Lower 5F4
51 (10,000 cst, (30,000 cst, io million cst)
t, 300,000 cst) (Toshiba Silicone), etc.

It is known that silicone is used in polishing tapes, and some tapes contain 300 g of polishing agent A/polishing agent B and 2 g of silicone oil (dimethylpolysiloxane). (Unexamined Japanese Patent Publication No. 54-97408 Example 1, Fuji Photo Film) However, this was used as a general lubricant, and the amount added was the same as that required for a lubricant. be.

Next, examples of the composition of the coating liquid for the polishing tape of the present invention will be described.

Example (Example 1) Coating liquid composition Abrasive material α-ALzO3 (size 16 microns)...
300 parts Vinyl chloride-vinyl acetate-vinyl alcohol copolymer 55 parts Polyester polyol 35
Department K F -961-1-500000...
0.3 parts (dimethylpolysiloxane, viscosity g, 500,000 cs
t) n-butyl acetate...
・With a composition of 350 parts or more, use a ball mill to spread the fractionated liquid onto a 25 micron thick polyester film.
It was applied to a micron thickness. Thereafter, a 1/2 inch polishing tape was prepared. In the same manner, trial production was repeated a total of 10 times. All parts by weight are based on solid content.

(Example 2) After forming a tape by removing silicone in Example 1, silicone was applied to the other side of the support at 80 Ily/rt.
It was applied to t.

Coating liquid composition Abrasive material α-ALzO3 (size 16 microns)...
300 parts Vinyl chloride-vinyl acetate-vinyl alcohol copolymer 55 parts Polyester polyol 35
Part vinegar ln-butyl...3
50 parts Coated on the other side K F -968-500000 (Dimethylpolysiloxane, viscosity 500,000 cst) (Comparative Example 1) In Example 1, the silicone was changed to a low viscosity one,
Other polishing tapes were prepared in the same manner.

Abrasive material α-A, L203 (size 16 microns)・
...300 parts Vinyl chloride-vinyl acetate-vinyl alcohol jLffi combination ...5
5 parts polyester polyol ・・・・・・
35 parts K116-100 (dimethylpolysiloxane, viscosity 100 cst) n-butyl acetate 350 parts (Comparative Example 2) After removing the silicone in Comparative Example 1 to form a tape, the other side of the support was Add silicone to 80■/TItk
: Applied.

Coating liquid composition Abrasive material α-A9J2o3 (size 16 microns)...
...300 parts Vinyl chloride-vinyl acetate-vinyl alcohol copolymer ...55 parts Polyester polyol ...35
Lobyl acetate...3
50 parts Coated on the other side KF96-100 (dimethylpolysiloxane, viscosity 100cst) For each of the polishing tapes of Examples 1 and 2 and Comparative Examples 1 and 2, the variations in the coefficient of friction and the variations in polishing ability were investigated and the results were reported. It is shown in Table 1.

In Table 1, the variation in friction coefficient is the friction coefficient with respect to the stainless steel rod.

Further, the variation in polishing ability is the variation in 10 head polishing cans [μ/min] when video heads are polished, expressed as a percentage of the average value.

According to Table 1, in this example, the variation in friction coefficient was also 0.18~0.20 → 0.02 0.18~0.1
8→0.00, and it can be seen that the variation in polishing ability is also a very small percentage compared to the comparative example.

<Effects of the Invention> Since the polishing tape according to the present invention has high viscosity silicone present on the surface of the support where the polishing layer is not formed, the high viscosity silicone acts as a lubricant on the support surface. Therefore, when the abrasive tape is running, the friction between the support surface and the abrasive tape running system is good, and abrasive tapes of the same composition always exhibit the same abrasive performance regardless of storage conditions or usage environment. It turns out.

Therefore, variations in polishing performance from lot to lot of polishing tape or from part to part within the same tape can be prevented, and repeatability of the polishing tape and the object to be polished is improved. Moreover, for this reason, the head yield is improved and the polishing effect is also improved.

Moreover, since high viscosity silicone is used, even if the amount added is small, a large effect can be achieved and efficiency is high.

[Brief explanation of drawings]

The drawing is an enlarged view of a polishing tape according to an embodiment of the present invention during polishing of a magnetic head. 1...Support 1a...-and 1b
・・・Other surface 2...Ken @ layer 3・
...Abrasive 4...Magnetic head (voluntary) procedure? mm Record, Indication of the case, Patent Application No. 61-68177 2, Name of the invention Abrasive tape 3, Person making the amendment Relationship with the case Patent applicant Location 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name Name
Fuji Photo Film Co., Ltd. 4, Agent Address: 7th Floor, Hauraiya Building, 5-2-1 Roppongi, Minato-ku, Tokyo 160 Exit (479) 2367 (73)
18) Patent attorney Yanagi 1) Seishi (and 2 others) 5. Date of amendment order None 6. Number of inventions increased by amendment None 7. Subject of amendment ``Detailed description of the invention'' column of the description 8. Contents of amendment 1) Specification, page 11, line 9

Claims (1)

[Claims] An abrasive tape comprising an abrasive layer containing an abrasive, a binder, and an additive coated on one side of a flexible support, characterized in that high-viscosity silicone is present on at least the other side of the flexible support. and polishing tape.