JPH11279539A - Composition for polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compsn. for polishing which is excellent in the dispersion stability of abrasive particles and provides a high polishing quality at a high polishing speed by incorporating an abrasive material and a polycarboxylic acid polymer having carboxyl groups and polyalkylene oxide structures on side chains into the same. SOLUTION: This compsn. comprises (A) an abrasive material having an average particle size of 0.005-50 μm and (B) a copolymer of a polyalkylene glycol alkenyl ether of the formula: R<1> O(AO)n R<2> with maleic anhydride, or its hydrolyzate and/or its salt with an at least divalent metal (e.g. calcium or aluminum), in an amt. of ingredient B of 0. 1-50 wt.%, and if necessary is further mixed with a specified amt. of a solvent and used in the form of a slurry. Examples of the abrasive material are aluminum oxide (e.g. fused white alumina or active alumina) and ceramics such as coprecipitated stable zirconia, silicon carbide, titanium carbide, and sialon. In the formula, R<1> is vinyl or allyl; AO is a 2-4C oxyalkylene; n is 1-200; and R<2> is H or a 1-20C org. group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a powdery polishing composition.

[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 polishing efficiency and polishing quality, chemical etching agents such as acids or alkali chemicals, and polishing compositions containing a dispersant such as a polycarboxylic acid solution have been studied, but they are not always satisfactory. In addition, since the composition is complicated, a composition previously prepared as a slurry composition must be used, and the method of use is restricted.

In addition, the conventional polishing composition has insufficient dispersion stability of the abrasive particles in the slurry, and causes agglomeration of the abrasive particles during storage to cause precipitation. Or agglomerate to form secondary particles,
There is a problem that the apparent particle diameter becomes large and the polished surface is scratched to cause surface defects. Therefore, measures such as adding an anti-caking agent and using a dispersant having more excellent sedimentation stability have been performed. However, these have not always been satisfactory. Therefore, there has been a demand for a powdery polishing composition that can easily adjust the polishing slurry as required at the actual polishing site or the like, and has excellent polishing efficiency and polishing quality. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of these circumstances, and has a high polishing rate, good polishing quality, excellent dispersion stability of abrasive particles, and requires only mixing with a solvent. The present invention relates to a powdery polishing composition capable of easily adjusting a polishing slurry.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that they contain an abrasive and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain. The powdery polishing composition to be formed easily becomes a polishing slurry simply by being mixed with a solvent, the polishing amount is large, the polishing operation is efficient, and surface defects such as scratches and pits are hardly generated, and the shape precision is also reduced. The present invention was found to be excellent and the dispersion stability of the abrasive was also excellent, and the present invention was completed.

That is, a first aspect of the present invention is powdery polishing containing an abrasive and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain (hereinafter, referred to as “polycarboxylic acid polymer”). It is a composition for use.
In the second invention, the polycarboxylic acid-based polymer has a general formula (1)
Or a copolymer of a polyalkylene glycol alkenyl ether and maleic anhydride, or a hydrolyzate thereof and / or a salt of the hydrolyzate (hereinafter, referred to as “MA polycarboxylic acid polymer”). It is a powdery polishing composition of the first invention.

[0007]

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,
R ² is hydrogen or an organic residue having 1 to 20 carbon atoms)

A third invention relates to a powdery MA polycarboxylic acid polymer in which the MA polycarboxylic acid polymer is a salt with a divalent or higher-valent metal (hereinafter referred to as a “divalent salt MA polycarboxylic acid polymer”). "). The powdery polishing composition according to the second aspect of the present invention. The fourth invention is to adjust the slurry by mixing the abrasive and the polycarboxylic acid polymer and the solvent,
This is a method for producing the powdery polishing composition of the first, second or third invention by drying the slurry to powder. A fifth invention is a method for producing the powdery polishing composition according to the third invention, by mixing the abrasive and the powdery MA polycarboxylic acid polymer according to the third aspect.

[0010]

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., vinyl ether-maleic anhydride copolymer, olefin
There is an esterified product of an unsaturated vinyl monomer and an unsaturated dicarboxylic acid copolymer such as a maleic anhydride copolymer and a styrene-maleic anhydride copolymer with an alkylene glycol compound.

As the unsaturated groups described in JP-A-8-12396, JP-A-62-216950, JP-A-1-226575, JP-A-6-206750, etc., a (meth) acrylate group is used as an unsaturated group. And a copolymer of 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, an MA polycarboxylic acid polymer which is a salt of a hydrolyzate is suitably used. Particularly, those in which R1 is a vinyl group are most preferably used.

[0014]

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,
R ² is hydrogen or an organic residue having 1 to 20 carbon atoms)

A powdery salt of the MA polycarboxylic acid polymer with a divalent or higher valent metal can be suitably used. Calcium, magnesium, aluminum and the like can be used as the divalent or higher metal,
The use of calcium is preferred in terms of cost and low hygroscopicity.
The polishing composition can be obtained by simply mixing the MA polycarboxylic acid polymer with an abrasive.

The divalent salt MA polycarboxylic acid polymer is prepared by adding a salt or hydroxide of a divalent or higher metal to an MA polycarboxylic acid polymer melt, an aqueous solution of the MA polycarboxylic acid polymer or an organic solvent solution. Can be reacted in the presence of a small amount of water, if necessary, to form a salt, and then dried and pulverized, or precipitated with a poor solvent, filtered and dried. As a drying method, a drum dryer,
A drying device such as a spray dryer or a filtration dryer can be used.

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 specified unconditionally because it depends on the type of 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 terms of average particle size.
In the range of 0.5 to 50 μm, preferably 0.01 to 10 μm.
μ.

The amount of the polycarboxylic acid polymer added can be in the range of 0.1 to 50% by weight based on the abrasive. It is preferably from 0.1 to 10% by weight, particularly preferably from 0.5 to 6% by weight.

The powdery polishing composition of the present invention is obtained by adding an abrasive or a raw material for an abrasive powder to a polycarboxylic acid-based polymer melt, an aqueous solution of a polycarboxylic acid-based polymer or an organic solvent. After that, if necessary, classification, drying,
It can be manufactured by a pulverized process. As a drying method, a drying device such as a drum drier or a spray drier can be used, but it is sufficient that the mixture of the polycarboxylic acid polymer and the inorganic powder is finally powdery, and the production method is not particularly limited.

The powdery polishing composition of the present invention is required for the final powdery polishing composition in a step of producing abrasive particles such as a step of wet grinding a raw material for an abrasive and a step of wet classification. A method of obtaining a powdery polishing composition by adding abrasive particles in advance by adding a polycarboxylic acid-based polymer in advance, or a method of previously manufacturing powdery abrasive particles having a high polycarboxylic acid-based polymer content. In addition, it can also be manufactured by a method of mixing in the final step with an abrasive required for the final powdery polishing composition, or a method of manufacturing a divalent salt MA polycarboxylic acid-based polymer and then mixing with the abrasive.

The powdery polishing composition further comprises a polishing accelerator, an anti-gelling agent, a surfactant, a dispersant,
Preservatives, stabilizers, defoamers, anti-caking agents and pH
An acid or alkali agent for adjustment may be contained.

The powdery polishing composition can be used as a polishing slurry by mixing with a required amount of a solvent.

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 type LCD, liquid crystal color filters, LCDs for watches, calculators, cameras, LCDs for solar cells, etc., glass substrates for LSI photomasks, glass substrates for optical disks and magnetic disks, and various glass materials such as optical lenses And carbon substrates such as graphite and glassy carbon for disk substrates that are storage devices for semiconductor wafers and computers, etc., plastic lenses for optics, plastic lenses for cameras, plastic lenses 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, and amenite , Sialon and the like, and metal products such as iron, steel, stainless steel, copper, copper alloy, zinc, and cemented carbide, but are not particularly limited thereto.

Next, the present invention will be described in more detail with reference to examples.

[0027]

EXAMPLES (1) Production Examples of Powdery Polishing Compositions (a) to (d) 100 parts of aluminum oxide (α-Al ₂ O ₃ , average particle size 1.2 μm) as a polishing material, polycarboxylic acid type After mixing 1 part of methoxypolyethylene glycol acrylate-acrylic acid copolymer sodium salt and 50 parts of pure water as a polymer to prepare a slurry, the slurry was spray-dried with a hot air inlet temperature of 125 ° C and a hot air outlet temperature of 75 ° C.
The composition was spray-dried at 1250 ° C. and a disk-type atomizer rotation speed of 12,500 rpm to obtain a powdery polishing composition (a). Also,
Powdered polishing compositions (b) to (d) were produced in the same manner except that the type and amount of the polycarboxylic acid polymer used were changed as shown in Table 1.

(2) Preparation Examples of Powdery Polishing Compositions (e) and (f) As the polycarboxylic acid polymer, an MA polycarboxylic acid polymer, methoxypolyethylene glycol vinyl ether-maleic anhydride copolymer 100 And an aqueous solution consisting of 50 parts of pure water while heating the solution to a temperature of 60 ° C.
Calcium hydroxide is added so that H becomes 7 to 8;
An aqueous calcium salt solution of a methoxypolyethylene glycol vinyl ether-maleic anhydride copolymer, which is a multivalent salt MA polycarboxylic acid polymer, was obtained. Next, the aqueous solution was dried and roughly pulverized at 80 ° C. by a ventilation rotary drier containing iron balls. The coarsely pulverized product was finely pulverized and classified by an ACM pulperizer to obtain a powdery divalent salt MA polycarboxylic acid polymer. And aluminum oxide (α-Al
1 part of the polymer was added to and mixed with 100 parts of ₂ O ₃ (average particle size: 1.2 μm) to prepare a powdery polishing composition (e). Further, a powdery polishing composition (f) was produced in the same manner except that the amount of the divalent salt MA polycarboxylic acid polymer used was changed as shown in Table 1.

[0029]

[Table 1]

(Examples 1 to 6) A slurry prepared on site by adding 400 parts of pure water to 100 parts of the powdery polishing composition shown in Table 1 obtained in the production example, and having a thickness of 130 mm outside aluminum 30μm thick on both sides of disk-shaped substrate
Table 2 shows the results of evaluating the polishing rate and the surface defect of the polished body when the polished body having been subjected to the nickel-phosphorus plating was polished.

(Comparative Example 1) The same procedure as in Example 1 was carried out except that the powdery polishing composition of Example 1 was changed to the same amount of abrasive as the abrasive in the powdery polishing composition. .

(Evaluation method) A polishing machine used was a double-side polishing machine, and a suede cloth was used as a polishing pad. Polishing was performed for 10 minutes by attaching the object to be polished to the polishing machine, abutting the polishing pad, and relatively sliding the object to be polished and the polishing pad. The conditions are a polishing pressure of 50 g / cm 2, a polishing slurry supply rate of 200 ml between the object to be polished and the polishing pad.
/ Min. The polishing rate was calculated from the thickness of the object before and after polishing, and the surface after polishing was inspected to measure the surface defects.

[0033]

[Table 2]

(Examples 7 to 12) The same as the powdery polishing compositions (a) to (d) used in Example 1 except that cerium oxide (average particle size: 0.6 μm) was used as the abrasive. Powdery polishing compositions (g) to (j) are produced by the method of
(K) and (l) were produced in the same manner as the powdery polishing compositions (e) and (f), and a comparative polishing test was performed using a disc-shaped glass substrate as the object to be polished. Was performed in the same manner as described above. Powdery polishing composition used (g)-
(L) is shown in Table 3, and the test results are shown in Table 4.

(Comparative Example 2) The same procedure as in Example 7 was carried out except that the powdery polishing composition of Example 7 was changed to the same amount of abrasive as the abrasive in the powdery polishing composition. .

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

(Examples 13 to 18) In the same manner as in Examples 1 to 6, powdery polishing compositions (a) to (f) were used, and a disc-shaped glassy carbon substrate was used as the object to be polished. A polishing property comparison test was performed in the same manner as in Examples 1 to 6, except that the polishing conditions were a polishing pressure of 100 kgf / cm2, a polishing time of 30 minutes, and a polishing slurry supply rate of 50 cc / min. The polishing rate is calculated by calculating the ratio of the polishing rate when the amount of polishing when the polycarboxylic acid polymer is not added to 1 is calculated from the thickness of the object to be polished before and after polishing, and measuring the stylus type surface roughness. did. Table 5 shows the test results.
Shown in

Comparative Example 3 The same procedure as in Example 13 was carried out except that the powdery polishing composition of Example 13 was changed to the same amount of abrasive as the abrasive in the powdery polishing composition. .

[0041]

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 (5)

[Claims] 1. A powdery polishing composition containing an abrasive and a polycarboxylic acid polymer having a carboxyl group and a polyalkylene oxide structure in a side chain. 2. The polycarboxylic acid-based polymer is a copolymer of polyalkylene glycol alkenyl ether represented by the general formula (1) and maleic anhydride, or a hydrolyzate and / or a salt of the hydrolyzate thereof. The powdery polishing composition according to claim 1, wherein 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) 3. The powdery polishing composition according to claim 2, wherein the polycarboxylic acid polymer is a powdery salt with a divalent or higher valent metal. 4. The powdery polishing composition according to claim 1, wherein the slurry is prepared by mixing an abrasive, a polycarboxylic acid polymer, and a solvent to prepare a slurry, and then drying the slurry to form a powder. Method of manufacturing a product. 5. The powdery polishing composition according to claim 3, wherein a powdery polycarboxylic acid-based polymer which is a salt of the abrasive and the divalent or higher valent metal according to claim 3 is mixed. Manufacturing method.