JPS61218680A - Liquid for polishing - Google Patents

Abstract

PURPOSE:To obtain a polishing liquid containing abrasive grains resistant to precipitation with time and feedable stably to a polisher, by using a water-soluble polymer containing an essential constituent component comprising an unsaturated monomer having a specific functional group. CONSTITUTION:Diamond abrasive grains are dispersed in a dispersion medium composed of water and a water-soluble polymer containing an essential constituent component comprising a monoethylenic unsaturated monomer having carboxylic acid (salt) group, amino group, hydroxyl group, ether group, amide group or quaternary ammonium salt group. The viscosity of the polishing liquid can be varied from a low level to a high level according to the use by changing the content and the molecular weight of the polymer.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a polishing liquid.

[Conventional technology]

Conventionally, polishing fluids have been prepared by mixing abrasive grains such as magnesium oxide with water to which a thickener such as glycerin has been added (Japanese Patent Laid-Open Publication No. 139479/1983).

However, in this method, the abrasive grains tend to settle over time, so a machining liquid containing a small amount of abrasive grains is supplied to the material to be polished, increasing the time required for polishing.

It is necessary to stir and mix the machining fluid before supplying it, which has the problem of significantly reducing workability.

[Problem that the invention seeks to solve]

The inventors of the present invention have conducted extensive studies in order to obtain a polishing liquid that prevents abrasive grains from settling over time and that can be easily supplied stably.
We have arrived at the present invention.

[Means for Solving the Problems] The present invention provides a monoethylenic compound containing a group selected from the group consisting of a carboxylic acid (salt) group, an amino group, a hydroxyl group, an ether group, an amide group, and a quaternary ammonium base. Water-soluble polymer (A) containing unsaturated monomer (a) as an essential component
, a polishing liquid characterized by containing water and diamond abrasive grains.

Examples of the monoethylenically unsaturated monomer that is an essential component of the water-soluble polymer in the present invention include the following monomers and mixtures of two or more thereof.

1. Monomers containing carboxylic acid (salt) groups (1) Monomers containing carboxylic acid groups: monoethylenically unsaturated mono- or polycarboxylic acids such as (meth)acrylic acid (meaning acrylic acid and/or methacrylic acid) (hereinafter the same expressions will be used), maleic acid and fumaric acid.

(Carboxylic anhydride group-containing monomer: monoethylenically unsaturated polycarboxylic anhydride such as maleic anhydride.

(3J carboxylic acid group-containing monomer: aqueous solution of monoethylenically unsaturated mono- or polycarboxylic acid [full h')
Metal (Na, K, etc.) salts, ammonium salts, amines (alkanolamines such as triethanolamine,
[lower alkyl amines, such as methylamine) salts, etc.] such as sodium (meth)acrylate, [meth)acrylic acid triethanolamine salt, sodium maleate, and methylamine maleate salt.

2. Amino group-containing monomers: amino group-containing esters of monoethylenically unsaturated mono- or dicarboxylic acids (dialkylaminoalkyl esters, dihydroxyalkylamino esters, morpholinoalkyl esters, etc.) such as dimethylaminoethyl [methacrylate, diethylaminoethyl ( meth)acrylate, morpholinoethyl [methacrylate, dimethylaminoethyl fumarate: heterocyclic vinyl compounds such as vinylpyridines (
A-vinylpyridine, 4-pinylpyridine, N-vinylpyridine), N-vinylimidazole or salts of these with monocarboxylic acids such as acetic acid and propionic acid.

3. Hydroxyl group-containing monomer: monoethylenically unsaturated alcohol such as (meth)allyl alcohol; polyol (alkylene glycol, glycerin).

monoethylenically unsaturated esters of polyoxyalkylene glycols, etc.) such as hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate,
Triethylene glycol (meth)acrylate and the monomer described in JP-A-51-112447.

4. Ether group-containing monomer (but not hydroxyl group-containing): alkyl CC+~p of alkylene oxide addition type compound of monoethylenically unsaturated mono- or polycarboxylic acid
4) Ethers such as (meth)acrylic acid ethylene oxide (A mol) adduct methyl ether, alkyl CC1-C4 of monoethylenically unsaturated alcohols) ethers such as methyl ether of (meth)allylic alcohol, and JP-A-51-112447. Monomer described in the publication.

5. Amide group-containing monomer: (meth)acrylamide: N
- alkyl (meth)acrylamides such as N-methylacrylamide; N,N-dialkyl (meth)acrylamides such as N,N'-dimethylacrylamide;
N-hydroxyalkyl (meth)acrylamide such as N-hydroxyethyl (meth)acrylamide, N
, N'-dihydroxyalkyl (meth)acrylamide such as N,N-dihydroxyethyl (meth)acrylamide; vinyl lactams such as N-vinylpyrrolidone.

6. Quaternary ammonium base-containing monomer: N, N, N
-trialkyl-N-(meth)acryloyloxyalkylammonium salts such as N,N,N-trimethyl-N
-(meth)acryloyloxyethylammonium chloride and the monomers described in British Patent No. 1,084,296.

Among the monomers mentioned above, monomers containing carboxylic acid (salt) groups and amino groups are preferred from the viewpoint of easy formation of water-soluble polymers, and particularly preferred are monomers containing (meth) groups.
Acrylic acid, sodium (meth)acrylate, (meth)
Acrylic acid triethanolamine salt, dimethylaminoethyl (meth)acrylate, salt of dimethylaminoethyl (meth)acrylate with acetic acid, diethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)
It is a salt of acrylate and propionic acid.

The monomer in the present invention may be used in combination with a water-insoluble monomer that can be copolymerized with the monomer. Examples of such water-insoluble monomers include ester group-containing monomers such as lower alkyl (01-Cs) esters of monoethylenically unsaturated carboxylic acids [methyl [methacrylate], ethyl (meth)acrylate, 2-ethylhexyl (meth) ) acrylates, etc.; esters of monoethylenically unsaturated alcohols such as vinyl acetate, (meth)allyl acetate; nitrile group-containing monomers such as (meth)acrylonitrile; styrenic monomers such as styrene. Examples include α-methylstyrene.

The content of water-insoluble monomers is usually 50% by weight or less, preferably 20% by weight or less of the total monomers.

As the polymer used in the present invention, single or copolymers of the above-mentioned monomers, and water-soluble copolymers of the above-mentioned monomers and water-insoluble monomers can be used.

Examples of the polymers used in the present invention are as follows.

Sodium salt of Polymer A1 (niacrylic acid/2-hydroxyethyl methacrylate/methyl acrylate) (78:26:1) copolymer.

'N combination & 2 dimethylaminoethyl methacrylate-4
Polymeric propionate.

Polymer Todoroki 3: Sodium salt of maleic acid/acrylic acid/methyl methacrylate (80:60:10) copolymer.

Polymer 5: Triethanolamine salt of 4-niacrylic acid/2-hydroxyethyl methacrylate (70:30) copolymer.

Polymer & 5: Triethanolamine salt of maleic acid/acrylic acid/2-hydroxyethyl methacrylate ([):60:10) copolymer.

In the above, the numbers in parentheses indicate the weight ratio of the monomers.

The polymer used in the present invention can be produced by a known method. For example, the aforementioned monomers, optionally together with water-insoluble monomers, are used as polymerization initiators (eg peroxides such as benzoyl peroxide).

Azo compounds such as azobisisobutyronitrile.

Usually 40% in the presence of a persulfate (such as sodium persulfate)
Obtained by polymerizing at ~150°C,
be able to. Alternatively, a water-insoluble monomer that becomes water-soluble upon hydrolysis, such as a monomer f1 having at least one hydrolyzable group (ester group, nitrile group, etc.), is polymerized using a monomer (vinyl acetate, acrylonitrile, etc.), and then It can also be obtained by hydrolysis.

The polymer obtained by such filtration is either liquid or solid, and its viscosity is usually 100 to 20,000 cps, preferably 100 to IUOOQcps (measured at 80 DEG C. for a 50% aqueous solution).

The polymer of the present invention can also be used in combination with the polymer described in JP-A-54-48188. When used, the polymer in the present invention is generally used in an amount of 20% by weight or more, preferably 50% by weight or more of the total polymer.

The diamond abrasive grains in the present invention may be obtained from nature or may be artificially synthesized. The average particle size is usually 20μ or less, preferably 1011 or less. If the average grain size is larger than 20μ, the time required for polishing is shortened, but the surface roughness of the polished surface increases, and it is necessary to polish again using a machining liquid using abrasive grains with a smaller grain size.

Furthermore, it is difficult to stably disperse it in water.

Additives can be added to the processing fluid of the present invention if necessary. Such additives are rust preventive.

Anticorrosive agents such as organic amines (monoethanolamine, triethanolamine, cyclohexylamine 79morpholine, etc.), organic amine derivatives (J: alkylene oxide adducts of amines, fatty acid amides, etc.), aliphatic or aromatic carboxylic acids (caprylic acid, oleic acid, dimer acid, alkenylsuccinic acid, benzoic acid, etc.) and alkali metal salts and amine salts of these carboxylic acids; PH adjusters such as hydroxides of the above-mentioned amines and alkali metals.

and antifoaming agents such as silicone compounds and polyether compounds.

The formulation of the processing fluid of the present invention is as follows. 0%
is expressed as a percentage of the weight of the processing fluid. ) Polymer Usually 0.1-50% (preferably 1-80%) Diamond loose grain Usually 0.1-10% (preferably 0.
2-5%) Water Usually 35-99.8 colors (preferably 62-98 colors)
．． 7%) Additive Usually θ ~ 5% (preferably 0.1 to 3%) In the above, if the polymer content is less than 0.1%, the effect of stably dispersing diamond abrasive grains in water will be reduced. , and when it exceeds 50%, the viscosity of the machining fluid increases and is difficult to handle.

If the content of diamond abrasive grains is less than 0.1%, the polishing time will be longer, and if it exceeds 10%, the amount of edge sag on the surface of the material to be polished will increase, and the effect of just adding it will not be seen, making it economical. disadvantageous to

The processing fluid of the present invention can be produced by mixing diamond abrasive grains into water in which the polymer has been dissolved in advance and dispersing the mixture by stirring, or by mixing the polymer, water, and diamond abrasive grains simultaneously and stirring. A method of dispersing the particles may also be used. Even after the additive components are dispersed in water by diamond abrasive grains.

Alternatively, these three components may be added and dissolved simultaneously. The stirring method is a magnetic stirrer.

Stirring may be carried out by any method, including a method using a blade stirrer, a homomixer, or the like. Further, heating may be performed during stirring if necessary.

Materials to be polished using the processing fluid of the present invention include ceramics (silica-based, alumina-based, silicon carbide-based, silicon nitride-based, etc.), metal c steel, stainless steel, aluminum,
copper, nickel, etc.), plastics (nylon, polyacetal, polycarbonate, modified polyphenylene oxide, etc.).

Examples include glass and composite materials thereof (ceramic-ferrite, etc.).

Such materials to be polished are generally processed using a conventional lapping machine (manufactured by Nippon Engis).

Polished with speed fam, Washino Kikai, Fujikoshi Kikai Kogyo, etc.

The method of applying the machining fluid of the present invention may be the same as the conventional method of applying the machining fluid, and for example, the machining fluid may be dropped or sprayed onto a rough plate during polishing.

〔Example〕

The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto. The percentages in the examples are by weight.

Examples 1-10. Comparative examples 1 to 3 The processing fluid of the present invention was prepared as shown in Table-1.

Table-1 ★1 Polymer 51 is Polymer 51 described in the detailed description of the invention
shows. (Similarly below)) Table 2 shows the stable fabrics made over time using the Kaloe liquid of the present invention and the commercially available two liquids as a refrigerant.

Table 2 Note that L comparative examples 1 and 2 are also average grain I.
This is a Kaloe solution using water as a dispersion medium containing 1% of diamond abrasive grains with a diameter (L5/44-). According to the composition of the Caloe liquid described in the explanation (magnesium oxide with a particle size of 0°08 to 0.2 mm added to a mixture of glycerin and water), average particles of QrO were added instead of magnesium oxide.
-Using mourning diamond abrasive grains~Diamond ilt
1.0% grains, 2.5% glycerin and 96% water. ．． 5%
It is mixed in the ratio of

For stability over time, each Caloe solution was placed at 11% at room temperature and the dispersion state was observed with the naked eye. The symbols in Table 2 are as follows.

0: Uniformly dispersed Δ: Slightly separated ×: Separation The strength of the present invention as shown in Table 2 is the dispersion stability of the Loe solution (very good quality).

Example 11 When a magnetic head made of a composite material of ceramic and ferrite was polished using the machining fluid of Example 8, the surface roughness C was almost the same as that of G118 above, but the polishing time was was reduced to about 273 - and the results showed that it was sufficient to perform water washing once after processing, compared to 2 to 3 times in Comparative Example 1. In addition, the polishing machine is a high-breath automatic precision mirror lapping machine Model made by Engis.
12).

C Effect of invention The processing fluid of the present invention has the following effects.

(1) The dispersion stability of the machining fluid is good - abrasive grains are unlikely to settle over time.

(A) Workability is improved because a certain amount of diamond abrasive grains can be stably supplied to the material to be polished.

From low viscosity processing fluids to high viscosity processing fluids can be used depending on the purpose.

(4) A polished surface of high quality and high precision can be obtained.

(5) T using water as a dispersion medium: There is no risk of fire.

(6) It is easy to remove the processing fluid from the material to be polished.

(7) The processing fluid of the present invention can be used for ceramics, metals, and glass.

Useful for surface polishing of materials such as plastics.

(8) The characteristics of the abrasive grains themselves are not impaired.

Claims (1)

[Scope of Claims] 1. A monoethylenically unsaturated monomer containing a group selected from the group consisting of a carboxylic acid (salt) group, an amino group, a hydroxyl group, an ether group, an amide group, and a quaternary ammonium base ( A polishing liquid characterized by containing a water-soluble polymer (A) having a) as an essential component, water, and diamond abrasive grains. 2. The processing liquid according to claim 1, wherein (a) is a monoethylenically unsaturated monomer containing a carboxylic acid (salt) group and/or an amino group. 3. The content of (A) is 0.1 to 0.1 based on the weight of the processing fluid.
50% of the processing fluid according to claim 1 or 2. 4. The machining fluid according to any one of claims 1 to 3, wherein the diamond abrasive grains have an average particle diameter of 20 μm or less. 5. Claims 1 to 4, wherein the content of diamond abrasive grains is 0.1 to 10% based on the weight of the machining fluid.
Processing fluid as described in any one of paragraphs.