JPH0796468A - Abrasive tape and its manufacture - Google Patents

Abstract

PURPOSE:To provide an abrasive tape where the abrasive dot is not present, and the polishing with high polishing performance can be realized, and its manufacturing method. CONSTITUTION:The resin for the binder on the surface of the abrasive layer is removed by executing the etching treatment on the surface of the abrasive layer consisting of the transfer layer after forming the abrasive layer by the transfer layer, and the abrasive grains which are present on the surface of the abrasive layer are exposed from the resin for the binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing tape used for finish polishing of magnetic heads and magnetic disks, precision finish polishing of dies, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art For finish polishing of magnetic heads and magnetic disks, precision finish polishing of dies, etc., a coating agent in which abrasive grains are dispersed in a binder resin solution is applied to a polishing tape base material and dried. A polishing tape having a polishing layer formed thereon (for example, JP-B-53-44714) is used.

[0003]

The conventional polishing tape is
Abrasive grains are embedded in the binder resin forming the polishing layer, and the abrasive grains in the polishing layer are in a state of being covered with the resin.

In the polishing work with this polishing tape,
Since the binder resin forming the surface of the polishing layer hits the processed surface of the object to be polished, highly efficient polishing cannot be performed.

A polishing tape having a polishing layer formed by applying a coating agent to a polishing tape substrate cannot have a uniform polishing finish because the polishing layer has a large surface roughness.

On the other hand, according to the present invention, since the surface of the polishing layer is flat, uniform polishing can be performed without unevenness of polishing, and since the abrasive grains are exposed on the surface of the polishing layer, the polishing is performed. Provided are a polishing tape capable of performing high-performance polishing and a method for manufacturing the same.

[0007]

The polishing tape of the present invention comprises:
The polishing layer formed on the surface of the base material for the polishing tape is one in which abrasive grains are dispersed in a binder resin, and the polishing layer is composed of a transfer layer and is present on the surface of the polishing layer. The abrasive grains are exposed from the binder resin.

The method of manufacturing the polishing tape of the present invention is
A step of obtaining a transfer material for forming a polishing layer by applying a coating agent in which abrasive particles are dispersed in a binder resin liquid to the surface of a release film and drying the coating agent to form a polishing layer; The step of transferring the polishing layer of the transfer material to the surface of the base material via the adhesive layer or the pressure-sensitive adhesive layer, and the surface of the polishing layer transferred to the base material for the polishing tape are subjected to an etching treatment, And removing the binder resin on the surface to expose the abrasive grains.

In the method of manufacturing the polishing tape of the present invention,
A plastic film, such as a polypropylene film or a polyethylene terephthalate film, optionally treated with a release agent such as silicone is used as the release film when obtaining the transfer material for forming the polishing layer.

On the release surface of the release film, in the binder resin liquid, abrasive grains made of high hardness inorganic fine powder such as aluminum oxide, silicon carbide, chromium oxide,
5 to 60 g (solid component) of a coating agent in which abrasive grains having a particle diameter of about 0.1 to 60 μ are dispersed with zirconium oxide, diamond, iron oxide, boron nitride, emery, etc.
A polishing layer is formed by applying the polishing layer at a coating amount of about / m ² .

As the binder resin for the polishing layer, polyester, vinyl chloride / vinyl acetate copolymer, vinyl chloride / vinylidene chloride copolymer, acrylic ester copolymer, methacrylic ester copolymer, urethane resin, etc. may be used. Thermosetting resins such as thermoplastic resins, phenolic resins, epoxy resins, urethane curable resins, melamine resins, etc., and reactive resins made from a mixture of the above-mentioned thermoplastic resins and a bridging binder such as an epoxy compound or an isocyanate compound. Further, a resin or the like which is polymerized and crosslinked by radiation is used.

[0012] Toluene diisocyanate (TDI), xylylene diisocyanate (XDI), and hexamethylesylisocyanate are used for the functional groups (-OH, -NH ₂ , -COOH, etc.) in the binder resin. A polishing layer in which an isocyanate-based curing agent such as (HMDI) is mixed to an extent that the equivalent ratio represented by [isocyanate group (-NCO) / functional group of resin] is in the range of about 0.5 to 10 By using a coating agent for formation, a polishing layer composed of a thermosetting resin layer formed by a reaction between a functional group in a binder resin and a curing agent is used, and the polishing layer exhibits extremely excellent wear resistance and heat resistance. Is obtained.

The application of the coating agent for forming the polishing layer on the release surface of the release film is performed by two rolls, three rolls, and four rolls.
It can be carried out by a method such as roll coating such as a main roll, gravure coating, kiss coating, knife coating, bar coating, rod coating, comma coating, spray coating, park coating and the like.

The ratio of the binder resin and the abrasive grains in the coating agent for forming the polishing layer is generally such that when the abrasive grains are less than 100 parts by weight relative to 100 parts by weight of the binder resin, the polishing is performed. There is a possibility that a polishing layer having a good action may not be obtained, and if the abrasive grains exceed 1400 parts by weight with respect to 100 parts by weight of the binder resin, the binder strength of the binder component in the polishing layer may be insufficient and the polishing tape Abrasive grains may fall off during the polishing process.

Therefore, it is preferable to form the polishing layer by using a coating agent containing 100 to 1400 parts by weight of abrasive grains with respect to 100 parts by weight of the binder resin.

After coating and drying the coating agent for forming the polishing layer, a post-treatment such as heating or radiation irradiation is applied depending on the kind of the binder resin in the coating agent.
Usually, a polishing layer having a thickness of about 5 to 80 μm is formed.

In the step of transferring the polishing layer in the transfer material for forming the polishing layer onto the surface of the base material for the polishing tape via the adhesive layer or the pressure-sensitive adhesive layer, the polishing tape is applied to the surface of the polishing layer of the transfer material for forming the polishing layer. This is carried out by the step of stacking and pressing the base materials for use.

The adhesive layer or pressure-sensitive adhesive layer used for transferring the polishing layer to the surface of the base material for the polishing tape may be formed on the surface of the polishing layer of the transfer material for forming the polishing layer,
Alternatively, it may be formed on the surface of the base material for the polishing tape.

The polishing tape base material is paper, non-woven fabric, synthetic paper, or a plastic film having a thickness of about 12 to 150 μm, which has excellent properties such as mechanical strength, dimensional stability, and heat resistance. Plastic films made of terephthalate, polypropylene, polycarbonate, di-acetate acetate, tri-acetate acetate, polyethylene, polybutylene terephthalate, polyarylate, etc. are used.

The transfer of the polishing layer to the surface of the base material for the polishing tape is completed by peeling and removing the release film of the transfer material for forming the polishing layer.

Thereafter, the surface of the polishing layer transferred to the base material for the polishing tape is subjected to an etching treatment to remove the binder resin on the surface of the polishing layer to expose the abrasive grains, whereby the object of the present invention. Get the polishing tape.

For the etching treatment of the surface of the polishing layer composed of the transfer layer, an etching method using, for example, an oxygen plasma etcher, ion milling or an optical ashing device can be used.

The surface of the polishing layer is preferably etched to a depth of about 0.01 to 1.00 μm by etching the surface of the polishing layer.

[0024]

In the polishing tape of the present invention, the polishing layer formed on the surface of the base material for the polishing tape has the abrasive grains dispersed in the binder resin, and the polishing layer is composed of the transfer layer. Moreover, the abrasive grains present on the surface of the polishing layer are exposed from the binder resin.

Further, the method for producing the polishing tape of the present invention is
By forming a polishing layer comprising a transfer layer on the surface of the base material for the polishing tape, the surface is flat, and the polishing layer in a clogged state in which the abrasive grains are coated with the binder resin is formed, and subsequently, By subjecting the surface of the polishing layer composed of the transfer layer to an etching treatment, the binder resin on the surface of the polishing layer is removed, and the abrasive grains present on the surface of the polishing layer are exposed from the binder resin.

Therefore, in the polishing tape of the present invention, since the polishing layer is composed of the transfer layer, the flatness of the surface of the polishing layer allows uniform polishing without polishing spots.

Further, in the polishing tape of the present invention, since the abrasive grains are exposed on the surface of the polishing layer, the abrasive grains in the polishing layer directly contact the processed surface of the object to be polished, so that polishing with high polishing efficiency is achieved. Can be done.

Further, according to the method for producing a polishing tape of the present invention, the surface of the polishing layer is flat, and the polishing tape has the abrasive grains exposed on the surface of the polishing layer, that is, the polishing tape has no unevenness and is uniform. A polishing tape that can be polished efficiently can be obtained easily and accurately.

[0029]

EXAMPLES The specific constitution of the polishing tape of the present invention will be described below based on manufacturing examples.

Example 1 Thickness 25 whose surface is treated with a release agent of silicone
µ polyethylene terephthalate film "Teijin Ltd."
: SP-4 "on the release agent-treated surface of the release film, a coating agent for forming a polishing layer having the following composition" A "is applied at 20 g (dry) / m ² and dried to obtain a transfer material. It was

Composition “A” (1) Abrasive grains “White alumina with an average particle size of 2 μm (WA-6000) [Showa Denko KK]” 50 parts by weight (2) Binder Resin "Linear polyester resin [Toyobo Co., Ltd .: Byron ^# 200]" ... 20 parts by weight (3) Solvent "Toluene / MEK = 1/1" ...・ 30 parts by weight

Then, a urethane adhesive "Takeda Pharmaceutical Co., Ltd .: Takelac A-515 / Takenate A-50 = 9/1" was applied to the polishing layer surface of the transfer material at 5 g / m ² and then applied. A polishing tape substrate made of a 31 μm thick biaxially stretched polyethylene terephthalate film “Teijin KK: SG type” was laminated.

Further, after aging at 40 ° C. for 72 hours to cure the adhesive, the release film was peeled off and removed.

Then, the surface of the polishing layer was etched to a depth of 0.1 μ by an oxygen plasma etcher “Samco RIE 10NL” (manufactured by Samco International Laboratories), and the abrasive grains on the surface of the polishing layer were removed from the binder resin. A polishing tape (1) having an exposed polishing layer was obtained.

Comparative Example 1 A polishing tape base material made of a biaxially stretched polyethylene terephthalate film “Teijin KK: SG type” having a thickness of 31 μ was polished with the composition “A” used in Example 1 above. 20 g (dry) / m of coating agent for layer formation
² was applied and dried to obtain a polishing tape (2) for comparison.

Comparative Example 2 A polishing tape (3) for comparison was obtained by omitting the step of etching the polishing layer with the oxygen plasma etcher during the manufacturing process of the polishing tape of Example 1.

Experiment 1 The surface roughness (center line average roughness: Ra) of the polishing layer of each of the polishing tapes of Example 1 and Comparative Examples 1 and 2 was measured by a three-dimensional surface roughness meter "Kosaka Laboratory Ltd. ) ”. The results are shown in [Table 1].

Experiment 2 Using each of the polishing tapes of Example 1 and Comparative Examples 1 and 2, a rotary tape polishing machine was used to rotate at 4000 rpm.
m, pressure 0.7 kg / cm ² , polishing tape feed rate 5 m
The surface of the aluminum substrate for hard disk was polished under the polishing conditions of m / sec and polishing time of 3 sec.

The surface condition of the aluminum substrate for hard disk after polishing was observed with a 100 × optical microscope. The results are shown in [Table 1].

[0040]

[Table 1]

As is clear from the experimental results of the polishing tape of Comparative Example 1, the surface of the polishing tape base material was coated with a coating agent containing abrasive grains dispersed in a binder resin solution and dried to form a polishing layer. Since the surface roughness of the polishing layer of the formed polishing tape was large and non-uniform, there were many polishing spots on the surface of the polished aluminum base for a hard disk, and scratches were generated.

In the polishing tape having the polishing layer formed of the transfer layer, as is clear from the experimental results for the polishing tape of Comparative Example 2, the surface of the polishing layer is extremely flat, but the binder forming the polishing layer. Abrasive grains are buried in the resin for use, and the abrasive grains in the polishing layer are covered with the binder resin.

For this reason, at the time of polishing with the polishing tape of Comparative Example 2, the resin for the binder forming the surface of the polishing layer hits the surface of the aluminum substrate for hard disk, so that a good polishing effect was not obtained.

On the other hand, in the polishing tape according to Example 1, since the surface of the polishing layer was flat and the abrasive grains were exposed on the surface of the polishing layer, the surface of the aluminum base for hard disk was mirror-finished. It was possible to efficiently polish to a close state.

[0045]

According to the polishing tape of the present invention, uniform polishing without spots can be efficiently performed.

Further, according to the method for manufacturing a polishing tape of the present invention, it is possible to accurately obtain a polishing tape capable of efficiently performing uniform polishing without spots.

Claims (2)

[Claims] 1. A polishing tape having a polishing layer obtained by dispersing abrasive grains in a binder resin, wherein the polishing layer comprises a transfer layer, and the abrasive grains present on the surface of the polishing layer are exposed from the binder resin. Abrasive tape characterized by being. 2. A step of obtaining a transfer material for forming a polishing layer by applying a coating agent having abrasive particles dispersed in a binder resin liquid on the surface of a release film and drying the coating agent to form a polishing layer. And a step of transferring the polishing layer of the transfer material to the surface of the polishing tape base material via an adhesive layer or an adhesive layer, and subjecting the surface of the polishing layer transferred to the polishing tape base material to an etching treatment. And then removing the binder resin on the surface of the polishing layer to expose the abrasive grains, thereby producing a polishing tape.