JP3310686B2 - Polishing tape manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polishing tape used for a magnetic head, a magnetic disk, and other precision parts.

[0002]

2. Description of the Related Art Generally, a polishing tape of this kind is obtained by applying a coating material containing an abrasive powder and a binder on a tape base material and drying the coating material to form a polishing layer. The polishing power greatly depends on the filling ratio of the abrasive powder and the binder in the polishing layer. For this reason,
When preparing a paint containing an abrasive powder and a binder, a method of adding a dispersant to improve the dispersibility of the abrasive powder in the paint and thereby increase the above-mentioned filling rate is widely used.

[0003]

However, when a dispersant is used, the strength of the polishing layer is reduced, the abrasive particles are liable to fall off, and the durability as a polishing tape is deteriorated. In addition, usually, an organic solvent is used as a solvent in the coating for forming the polishing layer. However, drying after application causes generation of pores due to evaporation of the organic solvent in the polishing layer. Even so, the pores do not significantly improve the filling rate.

The present invention has been made in view of the above circumstances, and provides a method for producing a polishing tape having a high filling ratio of an abrasive powder and a binder in a polishing layer, excellent polishing power, and excellent durability. It is intended to be.

[0005]

Means for Solving the Problems The present inventor has conducted intensive studies to achieve the above object, and as a result, after forming a polishing layer on a tape base material, a specific high-density treatment was performed. In this case, the filling ratio of the abrasive powder and the binder in the polishing layer was remarkably increased, and it was found that a polishing tape having excellent polishing power and durability was obtained, which led to the present invention.

That is, the present invention provides a tape base material comprising:
After applying a coating material containing an abrasive powder and a binder and drying to form a polishing layer, the polishing layer is densified by a calendar , and the densification is performed.
The roll in contact with the surface of the polishing layer
The present invention relates to a method for producing a polishing tape, characterized in that the polishing tape is formed.

[0007]

In the present invention, when a polishing layer is formed on a tape base material and a high-density treatment is performed by a calendar, the polishing layer is formed in the polishing layer due to evaporation of an organic solvent. The pores shrink or disappear due to the compression of the polishing layer, and in the polishing layer, the filling ratio of the abrasive powder and the binder becomes remarkably high, and the abrasive particles are firmly bound to the binder, thereby increasing the toughness. Be rich.

Therefore, in the polishing tape obtained through this high-density treatment, the polishing layer is hardly deformed during polishing, and
In addition, the abrasive particles are less likely to fall off, exhibiting excellent durability. Since the energy required for polishing is spent on the deformation of the polishing layer is extremely small, the polishing power increases and the polishing efficiency increases. And the polished surface is sharpened.

Various roll arrangements can be used as a calendar used for such a high density treatment of the polishing layer. In particular, the roll in contact with the surface of the polishing layer is a cotton roll.
Preferably. That is, even if the filling ratio of the abrasive powder and the binder is improved by the high-density treatment, the polishing efficiency is lowered if the surface of the polishing layer is smoothed. Thereby, it is easy to increase the filling rate of the polishing layer while maintaining the surface of the polishing layer in a roughened state.

[0010] The filling ratio of the abrasive powder and the binder in the polishing layer is desirably 90% or more, and if it is too low, sufficient polishing power and durability cannot be obtained. The surface roughness of the polishing layer is preferably set to be 80% or more of the surface roughness before the high-density treatment. In order to achieve such a filling ratio and surface roughness, the roll temperature of the calendar by using the cotton roll is 30.
It is preferable that the pressure (linear pressure) is about 50 to 200 kg / cm ² .

As the abrasive powder, for example, Al
Examples include inorganic compound particles of high hardness such as ₂ O ₃ , SiC, Cr ₂ O ₃ , Fe ₂ O ₃ , and SiO ₂ , and those having an average particle diameter of about 0.1 to 10 μm are particularly preferable.

As the binder for the polishing layer, polyurethane resins, polyester resins, vinyl chloride-vinyl acetate copolymers, epoxy resins and the like, which are conventionally known for polishing layers, can be used alone or in combination of two or more. Can be used together. The amount of such a binder used is 100
The amount is preferably about 10 to 50 parts by weight with respect to parts by weight. If the amount is too small, the binding force is insufficient, and the abrasive particles tend to fall off, resulting in a decrease in durability. Conversely, if the amount is too large, the polishing power and the polishing efficiency become insufficient.

In order to form a polishing layer, a coating material comprising the above-mentioned abrasive powder, a binder and an organic solvent is prepared, and this coating material is coated on a tape base made of polyester or the like.
Apply so that the thickness after drying is about 3 to 50 μm,
It may be dried. After the formation of this polishing layer, the polishing tape of the present invention is obtained by performing the densification treatment using the above-mentioned calendar.

[0014]

As described above, according to the manufacturing method of the present invention, the filling rate of the abrasive powder and the binder in the polishing layer is high, the polishing power, the polishing efficiency, and the finish are all good. A highly durable polishing tape can be provided. In particular, in the high-density treatment using the calendar, according to the configuration in which the roll in contact with the surface of the polishing layer is a cotton roll, it is possible to avoid a decrease in polishing power due to the smoothing of the surface of the polishing layer.

[0015]

Next, an embodiment of the present invention will be described in more detail. In the following, “parts” means “parts by weight”.

Example 1 Al ₂ O ₃ powder (average particle size: 0.3 μm) 70 parts Polyurethane resin 30 parts (trade name N2301 manufactured by Nippon Polyurethane Co.) 100 parts methyl ethyl ketone The above composition was mixed to form a paint, This has a thickness of 25μ
It was applied on a tape base material having a thickness of 35 μm after drying, and dried to form a polishing layer.

Next, using a calender in which four cotton rolls each having a diameter of 30 cm are arranged in a stacked state, under the conditions of a roll temperature of 50 ° C. and a pressing force (linear pressure) of 80 kg / cm ² , the above-mentioned polishing layer is formed. The tape on which was formed was passed through at a speed of 50 m / min in a state where the surface of the polishing layer was in contact with the cotton roll, and a high-density treatment was performed to produce a polishing tape. The filling ratio of the polishing layer of this tape was 90%.

Example 2 A polished tape was produced in the same manner as in Example 1 except that the roll temperature of the calendar was changed to 70 ° C. This table
The filling rate of the polishing layer of the tape was 95%.

Example 3 A polishing tape was produced in the same manner as in Example 1 except that the pressure (linear pressure) of the calendar was changed to 100 kg / cm ² . The filling ratio of the polishing layer of this tape was 95%.

Comparative Example 1 Except that the high-density treatment by the calendar was not performed,
A polishing tape was produced in the same manner as in Example 1.

With respect to each of the polishing tapes obtained in Examples 1 to 3 and Comparative Example 1, the polishing amount, finishability, and durability were measured using a steel ball sliding wear tester.
The results are shown in Table 1 below together with the surface roughness of the polishing layer.

The finishability and durability were evaluated on a three-point scale, with 優秀 being excellent, △ being normal, and × being poor. The surface roughness of the polishing layer was measured by a needle contact type surface roughness meter, and expressed as a relative value with the value of the polishing tape of Comparative Example 1 taken as 100%. Further, the polishing amount was measured with a steel ball sliding wear tester as described above, and expressed as a relative value with the value of the polishing tape of Comparative Example 1 taken as 100%.

[0023]

[Table 1]

From Table 1 above, the polishing tapes (Examples 1 to 3) obtained by the method of the present invention are because the polishing layer has been subjected to a treatment for increasing the density of the polishing layer using a calendar after the formation of the polishing layer. Polished tape not subjected to this treatment (Comparative Example 1)
It is clear that, as compared with, the finish and the durability are excellent, and the abrasive has a sufficient polishing force.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-135481 (JP, A) JP-A-53-137493 (JP, A) JP-A-58-194192 (JP, A) JP-A-57-194 143737 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B24D 3/00-18/00

Claims (1)

(57) [Claims] 1. A tape - the flop substrate on a paint containing an abrasive powder and a binder, coating and drying, after forming the polishing layer, a calendar - the densification of the abrasive layer applied by the
In both cases, the surface of the polishing layer
A method for producing a polishing tape, characterized in that a roll in contact with a surface is a cotton roll .