JPH11228939A - Abrasive composition and abrading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an abrasive compsn. which provides high abrading speed and good abrasion quality by compounding an abrasive material with a polycarboxylic acid polymer having carboxyl groups and polyalkylene oxide structures on the side chains. SOLUTION: An esterification product of an alkylene glycol compd. (e.g. a vinyl ether-maleic anhydride copolymer), esp. a polyalkylene glycol alkenyl ether-maleic anhydride copolymer of the formula (wherein R<1> is vinyl or allyl; AO is 2-4C oxyalkyl; n is 1-200; and R<2> is H or a 1-20C org. residue) or its hydrolyzate, is pref. as the polycarboxylic acid polymer having carboxyl groups and polyalkylene oxide structures on the side chains. A generally used abrasive material, such as an alumina- or zirconia-based one or diamond, can be used and is compounded in an amt. of 1-50 wt.% of the compsn. The amt. of the polycarboxylic acid polymer compounded is 0.1-50 wt.%, pref. 0.5-6 wt.%, of the abrasive material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polishing composition for an aqueous slurry. More specifically, an aluminum magnetic disk which is a storage device of a computer or the like in which an aluminum substrate and a nickel substrate obtained by electroless plating nickel phosphorus on an aluminum substrate, an alumite substrate obtained by anodizing an aluminum substrate, and the like are used. Substrate and active matrix type LC
D, LCD color filter, LC for clock / calculator / camera
D or glass substrate for display such as solar cell, LS
Various glass materials such as glass substrates for I-photomasks, glass substrates for optical disks and magnetic disks or optical lenses, and carbon substrates such as graphite and glassy carbon for disk substrates used as storage devices for semiconductor wafers and computers. Plastic products such as plastic lenses for optics, plastic lenses for cameras, plastic lenses for eyeglasses, silicon carbide, silicon nitride, titanium nitride,
Ceramic molded or sintered bodies such as titanium carbide, boron carbide, boron nitride, alumina, aluminum nitride, silicon oxide, beryllium oxide, titanium oxide, zirconium oxide, mullite, spinel, cordierite, amenite, sialon, and iron, steel , Stainless steel, copper, copper alloy, zinc,
The present invention relates to a polishing composition and a polishing method used for polishing a metal product such as a cemented carbide.

[0002]

2. Description of the Related Art In various applications such as magnetic disks, optical disks, LCDs, and photomasks, high surface precision is required for polishing a substrate material. In general, a polishing composition of an aqueous slurry in which a powder of alumina, zirconia, ceria, silica, or the like is dispersed in water as an abrasive is used for the polishing. However, conventional polishing slurries
The polishing amount is small and the efficiency of the polishing operation is poor, and there are quality problems such as surface defects called scratches, orange peels, pits, etc., and low shape accuracy of the polished surface.

In order to improve this and improve the polishing efficiency and the polishing quality, polishing compositions to which various polishing accelerators have been added have been studied, but they have not always been satisfactory. In addition, the conventional polishing composition has insufficient dispersion stability of the abrasive particles in a water slurry, causes agglomeration of the abrasive particles during storage, and requires re-dispersion at the time of use because precipitation occurs. When agglomerated, secondary particles are generated, the apparent particle diameter increases, and the polishing surface is scratched, resulting in a problem of surface defects.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and has a high polishing rate.
An object of the present invention is to provide a polishing composition having good polishing quality and excellent dispersion stability of a polishing material.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and found that an abrasive, a polycarboxylic acid-based polymer having a carboxyl group and a polyalkylene oxide structure in a side chain (hereinafter referred to as “polycarboxylic acid polymer”). The polishing composition containing "a polycarboxylic acid-based polymer") and water as the active ingredients has a large polishing amount and good polishing efficiency, is hard to generate surface defects such as scratches and pits, and has a high shape precision. And excellent dispersion stability of the abrasive, and completed the present invention.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
As the polycarboxylic acid polymer used in the present invention,
For example, Japanese Unexamined Patent Publication No.
No. 818, Japanese Patent Publication No. 6-88817, etc. and unsaturated vinyl monomers such as vinyl ether-maleic anhydride copolymer, olefin-maleic anhydride copolymer and styrene-maleic anhydride copolymer. There is an esterified product of a copolymer of a saturated dicarboxylic acid and an alkylene glycol compound.

(Meth) acrylic acid esters as unsaturated groups described in JP-A-8-12396, JP-A-62-216950, JP-A-1-226575, JP-A-6-206750 and the like. There is a copolymer of a polyalkylene glycol derivative having a group, an unsaturated monocarboxylic acid or unsaturated dicarboxylic acid, and a monomer having a sulfonic acid group such as allylsulfonic acid and methallylsulfonic acid.

A monomer comprising a polyoxyalkylene derivative described in JP-A-7-53249, JP-A-7-215746, JP-A-8-165157, JP-A-7-232945, etc. There is a copolymer containing a group-containing monomer as an essential component.

Among them, a copolymer of polyalkylene glycol alkenyl ether represented by the general formula (1) and maleic anhydride, or a hydrolyzate thereof and / or
Alternatively, a salt of a hydrolyzate is suitably used. In particular, those in which R ¹ is a vinyl group are most preferably used.

[0010]

Embedded image (R ¹ is a vinyl group, an allyl group, AO is an oxyalkyl group having 2 to 4 carbon atoms, n is an integer of 1 to 200, and R ² is hydrogen or an organic residue having 1 to 20 carbon atoms)

The material of the abrasive in the present invention is not particularly limited as long as it is a material generally used as an abrasive. Examples thereof include fused brown alumina, fused white alumina, plate alumina, low soda alumina, and high purity. Aluminum oxide such as alumina, fine-particle alumina, activated alumina, high-purity zirconia, low-purity zirconia, coprecipitation stabilized zirconia, zirconia oxide such as electrofusion stabilized zirconia, zirconium silicate, cerium oxide, silicon carbide, boron carbide, cubic nitriding Various ceramics such as boron, titanium carbide, tungsten carbide, titanium nitride, sialon and silicon nitride; silicon oxide such as colloidal silica and fumed silica; diamonds such as artificial diamonds and natural diamonds; corundum, boehmite, garnet, emery, silica sand , Tripoli, Stone, diatomaceous earth, natural abrasives dolomite etc., and mixtures thereof.

The particle size of the abrasive cannot be determined unconditionally because it depends on the type of the substrate and the purpose of polishing, such as rough polishing or finish polishing. However, the particle size of the abrasive alone is 0.00 in average.
In the range of 0.5 to 50 μm, preferably 0.01 to 10 μm.
μ.

The weight ratio of the abrasive in the polishing composition is preferably 1 to 50% by weight. The amount of the polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in the side chain is 0.1 to 50 with respect to the abrasive.
It can be used in the range of weight%. Preferably 0.1
-10% by weight, particularly preferably 0.5-6% by weight.

The water used is not particularly limited, and pure water, deionized water, well water, tap water and the like can be used. The amount of water can be adjusted so that the abrasive and the polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in the side chain have the desired addition ratio.

The polishing composition may contain, in addition to the above components, a polishing accelerator, an anti-gelling agent, a surfactant, a dispersant, a preservative, a stabilizer, a defoaming agent and an acid for adjusting pH. Or you may contain alkali.

The method for producing the polishing composition is not particularly limited. For example, ground and classified abrasive particles are mixed with water and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain. To obtain a polishing composition. Further, in the step of producing abrasive particles such as a step of wet grinding the abrasive particles or a step of wet classification, a polycarboxylic acid having a carboxyl group and a polyalkylene oxide structure in a side chain for the purpose of preventing aggregation and sedimentation. Abrasive particles are manufactured by adding a polymer in advance, and as a result, a mixture of the abrasive particles and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain, and using the mixture. The polishing composition can also be adjusted.

The polishing composition of the present invention can be used for various types of polishing. For example, an aluminum magnetic disk substrate, which is a storage device of a computer or the like in which an aluminum substrate and a nickel substrate obtained by electroless plating nickel phosphorus on an aluminum substrate, an alumite substrate obtained by anodizing an aluminum substrate, and the like are used. , Active matrix LCD, liquid crystal color filters, LCDs for watches, calculators, cameras, glass substrates for displays such as solar cells, glass substrates for LSI photomasks, glass substrates for optical disks and magnetic disks, and optical lenses Glass materials, carbon substrates such as graphite and vitreous carbon for disk substrates which are storage devices for semiconductor wafers and computers, optical plastic lenses, plastic lenses for cameras, plastic glasses for glasses Plastic products such as silicon carbide, silicon nitride, titanium nitride, titanium carbide, boron carbide, boron nitride, alumina, aluminum nitride, silicon oxide, beryllium oxide, titanium oxide, zirconium oxide, mullite, spinel, cordierite, It is suitably used for ceramic molded products or sintered products such as stones and sialons and metal products such as iron, steel, stainless steel, copper, copper alloys, zinc and cemented carbides.

[0018]

Next, the present invention will be described in more detail by way of examples.

(Examples 1 to 6, Comparative Examples 1 to 3)
Aluminum oxide (α-Al ₂ O ₃ , average particle size 1.2
μ) and a slurry-like polishing composition was prepared from the polycarboxylic acid-based polymers listed below. Polymer: sodium salt of methoxypolyethylene glycol acrylate-acrylic acid copolymer Polymer: ammonium salt of hydrolyzate of polyethylene glycol monoallyl ether-maleic anhydride copolymer Polymer: methoxypolyethylene glycol vinyl ether-maleic acid Ammonium salt of polymer hydrolyzate

The content of the aluminum oxide in the polishing composition was adjusted to 20% by weight. The polycarboxylic acid-based polymer was adjusted to 1 to 5 by weight% based on aluminum oxide. For comparison, a slurry-like polishing composition containing no polycarboxylic acid-based polymer,
A polishing composition containing no polyalkylene oxide structure in the side chain was also prepared. Polymer: ammonium polyacrylate

For polishing, a double-side polishing machine was used as a polishing machine, and a suede cloth was used as a polishing pad.
A material to which 0 μm nickel-phosphorus plating was applied was used as a polishing object. The object to be polished was attached to a polishing machine, a polishing pad was brought into contact with the object, and the object to be polished and the polishing pad were slid relatively to each other for polishing for 10 minutes. The polishing pressure is 50 g / cm2. During polishing, apply the polishing composition between the object to be polished and the polishing pad.
It was supplied at a rate of 00 ml / min.

Before and after polishing, the thickness of the object to be polished was measured to calculate the polishing rate. The polished surface after polishing was inspected to measure surface defects. Further, in order to evaluate the dispersion stability of the polishing composition, a settling state after the polishing composition was left for one day was observed. Table 1 shows the experimental results.

[0023]

[Table 1]

As is clear from Table 1, Examples 1 to 6, and especially Examples 3 to 6, were superior to Comparative Examples 1 to 3 in polishing rate, polishing accuracy, and dispersion stability. Further, the cross-sectional shape of the object to be polished was observed, and the edge sag (shape accuracy) was also evaluated.

(Examples 7 to 12, Comparative Examples 4 to 6) Except that cerium oxide (average particle diameter: 0.6 μm) was used as an abrasive and a circular disk glass disk was used as an object to be polished.
The test was performed in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 3.
Table 2 shows the results.

[0026]

[Table 2]

As is clear from Table 2, Examples 7 to 12, and particularly Examples 9 to 12, were superior to Comparative Examples 4 to 6 in polishing rate, polishing accuracy, and dispersion stability.

(Examples 13 to 18 and Comparative Examples 7 to 9) A circular disk-shaped substrate made of polycarbonate was used as the object to be polished.
Polishing pressure 200 g / cm2, supply rate of polishing composition 2
The test was carried out in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 3, except that 1 / min was used. The polishing amount was calculated from the weight before and after polishing. Table 3 shows the results.

[0029]

[Table 3]

As is clear from Table 3, Examples 13 to 18, especially Examples 15 to 18, were compared with Comparative Examples 7 to 9.
The polishing rate, polishing accuracy and dispersion stability were excellent.

(Examples 19 to 24, Comparative Examples 10 to 12)
Aluminum oxide (α-Al ₂ O ₃ , average particle size 1.2 μm) was used as the abrasive, and a disc-shaped carbon substrate was used as the object to be polished. The same method as in Examples 1 to 6 and Comparative Examples 1 to 3 was used. The polishing test was performed under the conditions of a polishing pressure of 100 kgf / cm2, a polishing time of 30 minutes, and a supply rate of the polishing composition of 50 cc / min. The polishing rate ratio when the polishing rate when the polycarboxylic acid-based polymer was not added was set to 1 was calculated from the thickness of the object to be polished before and after polishing, and the surface roughness was measured using a stylus type surface roughness meter. Was measured.

[0032]

[Table 4]

As apparent from Table 4, Comparative Examples 10 to 1
As compared with Example 2, Examples 19 to 24, especially Examples 21 to 24
Was excellent in polishing rate, polishing accuracy and dispersion stability.

[0034]

The powdery polishing composition of the present invention can be prepared in the same manner as when a slurry comprising a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain, an abrasive and a solvent is used. The polishing amount is large, the polishing operation is efficient, the defects on the polished surface hardly occur, and the shape accuracy is excellent, so that it is suitable for various precision polishing.

Claims (6)

[Claims] 1. A polishing composition comprising an abrasive and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain. 2. A polishing composition comprising an abrasive, a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain, and water. 3. A polycarboxylic acid-based polymer having a carboxyl group and a polyalkylene oxide structure in a side chain is a copolymer comprising a polyalkylene glycol alkenyl ether represented by the general formula (1) and maleic anhydride, or a copolymer thereof. 3. The polishing composition according to claim 1, which is a hydrolyzate and / or a salt of the hydrolyzate. Embedded image (R ¹ is a vinyl group, an allyl group, AO is an oxyalkyl group having 2 to 4 carbon atoms, n is an integer of 1 to 200, and R ² is hydrogen or an organic residue having 1 to 20 carbon atoms) 4. A polishing method comprising using the polishing composition according to claim 1. 5. The polishing method according to claim 4, wherein the object to be polished is a carbon substrate. 6. A polishing composition for a carbon substrate, comprising the polishing composition according to claim 1. Description: