JPS61207479A - Processing liquid for polishing - Google Patents

Abstract

PURPOSE:To obtain a processing liquid for polishing which is low in rate of settle with time of an abrasive grain contained therein and can stably supplied with ease, by incorporating a polyethylene glycol, water and abrasive grain of diamond. CONSTITUTION:A processing liquid for polishing containing a polyethylene glycol, water and an abrasive grain of diamond. The polyethylene glycol to be used includes those of which the molecular weight is generally 1,000-100,000, preferably 1,000-20,000 from the standpoint of availability. When the molecular weight is less than 1,000, no sufficient effect can be attained by dispersing an abrasive grain of diamond in water while a polyethylene glycol having a molecular weight of more than 100,000 is difficult to be synthesized. The average diameter of the diamond used is generally 20mu or less. The content of the abrasive grain of diamond is usually 0.1-10% based on the weight of the processing liquid. When the content is less than 0.1%, a longer period of time is required for polishing, while the content exceeding 10% causes an increase in amount of sag of a material to be polished at its edge portions.

Description

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

[Conventional technology]

Conventionally, a polishing liquid has been prepared by mixing abrasive grains such as magnesium oxide with water to which a thickener such as glycerin has been added (Japanese Patent Application Laid-open No. 189479/1983).

However, with this method, the abrasive grains tend to settle over time, so a machining fluid with a low abrasive grain content is supplied to the material to be polished, prolonging the polishing time, or the machining fluid is stirred in advance before being supplied. There is a problem in that it requires mixing, which significantly reduces workability.

[Problems that the invention attempts to solve]

The present inventors have arrived at the present invention as a result of intensive studies aimed at obtaining a polishing liquid in which abrasive grains are less likely to settle over time and can be easily supplied stably.

[Means for solving problems]

The present invention is a polishing liquid characterized by containing polyethylene glycol, water and diamond abrasive grains.

The polyethylene glycol used in the present invention usually has a molecular weight of 1,000 to 109, preferably 1,000 to 20,000 in view of easy availability. Molecular weight is 1000
If the diameter is smaller, the effect of stably dispersing diamond abrasive grains in water will be reduced, and if the molecular weight is greater than 100,000, it will be difficult to synthesize.

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 more, preferably 10μ or less.

If the average grain size is larger than 20μ, the polishing time will be shortened, but the surface roughness of the polished surface will increase, and it will be necessary to polish again with a machining fluid 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 (monoethane-amine, triethanolamine, cyclohexylamine, morpholine, etc.), organic amine derivatives (alkylene oxide adducts of the above 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 the above-mentioned amines and alkali metal hydroxides, and antifoaming agents such as silicone compounds and Examples include polyether compounds.

The formulation of the processing fluid of the present invention is as follows. [Chi is expressed as chi relative to the weight of the processing fluid.

Polyethylene glycol Usually 0.1-50 inches (preferably 1-80 inches) Diamond abrasive grain Usually 0.1-10% (preferably 0.2-5 inches) Water Usually 35-99.8 inches (preferably 1-80 inches) 98.7 inches) Additives Usually 0 to 5 inches (preferably 0
．． 1 to 3) In the above, the content of polyethylene glyco-ρ is 0.1
If it is less than 50%, the effect of stably dispersing diamond abrasive grains in water will be reduced, and if it exceeds 50%, the viscosity of the processing fluid will increase and it will be difficult to handle.

If the content of diamond abrasive grains is less than 0.1 inch, the polishing time will be longer, and if it exceeds 10 inch, the edge sagging of the surface of the material to be polished will be large, and the effect of just adding diamond abrasive grains 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 polyethylene glycol has been dissolved in advance and dispersing it by stirring, or by mixing polyethylene glycol, water and diamond abrasive grains simultaneously and dispersing by stirring. It may be a method. The additive component may be added after the diamond abrasive grains are dispersed in water using polyethylene glycol, or may be added and dissolved simultaneously with these three components. 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 (shoulderstone-based, alumina-based, silicon carbide-based, silicon nitride-based, etc.), metals (steel, stainless steel, aluminum,
copper, nickel, etc.)I 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, for example, the machining fluid may be dropped or sprayed onto a lap 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 numbers in the examples are based on weight.

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

Table-1 ★1: Polyethylene glycol) v (average molecular weight -200
0)★2. (1-8500
)★a: (# -20
Table 2 shows the results of the stability over time using the processing fluid of the present invention and a commercially available processing fluid as a comparative product.

Table = 2 ★4: Comparative products 1 and 2 both have an average particle size of 0.5μ
This is a machining fluid that uses water as a dispersion medium and contains one inch of diamond abrasive grains. Comparative product 3 has the composition of the machining fluid (
Magnesium oxide with a particle size of 0.08 to 0.1μ is added to a mixture of glycerin and water), diamond abrasive grains with an average particle size of 01μ are used instead of magnesium oxide, and diamond abrasive grains t, o%, 2.5% glycerin, and 96.5% water.

In the stability test over time, each processing solution was allowed to stand at room temperature, and the dispersion state was observed with the naked eye. The signals in Table 2 are as follows.

○: Uniformly dispersed Δ: Slightly separated ×: Separated From the results in Table 2, it can be seen that the processing fluid of the present invention has extremely good dispersion stability.

Example 11゜When a magnetic head made of a composite material of ceramic and ferrite was polished using the working fluid of Example 4, the surface roughness was almost the same as that of comparative product 1, but the polishing time was approximately The results showed that the process was shortened to V3, and that it was sufficient to perform water washing once after processing, compared to 2 to 3 times for Comparative Product 1. As the polishing machine, a pipeless automatic precision mirror lapping machine Mode+ 12 manufactured by Engis was used.

〔Effect of the invention〕

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

(1) The dispersion stability of the machining fluid is good, and the abrasive grains are less likely to settle over time.

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

(3) By changing the content and molecular weight of polyethylene glycol, it is possible to use processing fluids from low viscosity to high viscosity depending on the purpose.

(4) A high quality and highly accurate polished surface can be obtained.

(5) Since water is used 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)

[Claims] 1. A polishing liquid characterized by containing polyethylene glycol, water and diamond abrasive grains. 2. The molecular weight of polyethylene glycol is 1000-10
The machining fluid according to claim 1, which is 3. The machining fluid according to claim 1 or 2, wherein the content of polyethylene glycol is 0.1 to 50% based on the weight of the machining fluid. 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. The machining fluid according to any one of claims 1 to 4, wherein the content of diamond abrasive grains is 0.1 to 10% based on the weight of the machining fluid.