JP4363890B2 - Water-based polishing fluid - Google Patents

Description

【００２１】
【表２】

【００２２】
各実施例および比較例で試作した水系研磨加工液を使い、図１に示す研磨加工機で以下のとおり研磨加工をした。予めフェーシングした錫下定盤を用い硬質材料のワーク用テストピースとしてＳＵＳ３０４（５ｍｍ×５ｍｍ）をセラミックス上定盤にワックスで貼り付けた。水系研磨加工液を３０秒毎に３ミリリットル噴霧しながら、セラミックス板に３６．５ｋｇの荷重をかけ６０ｒｐｍで６０分研磨した。
【００２３】
研磨の終了したテストピースの研磨面を表面粗さ計（東京精密社製サーフコム５９０Ａ）で測定した。テストピースの研磨前後の重量差から加工レートを算出した。表面粗さRa(nm)、加工レートmg/mgのデータを、表１および表２に併せて記載してある。表１および表２から明らかなように本発明の水系研磨加工液を使った研磨面の表面粗さの値は小さく、加工レート、すなわち同一定条件下における研磨による減量が大きいことが分かる。
【００２４】
【発明の効果】
以上、詳細に説明したように、本発明の水系研磨加工液は研磨砥粒を安定して均一に分散でき、研磨能、浸透性がよく、摩擦熱の冷却効率が優れている。そのため本発明の水系研磨加工液を使うことによって、研磨加工面の表面粗さが小さいものとなる。また研磨加工による減量が大きく短時間で研磨できるようになる。すなわち、本発明の水系研磨加工液は、研磨精度の向上と研磨加工の時間短縮に資するところが大である。
【図面の簡単な説明】
【図１】研磨加工機による研磨加工の状態を示す図である。
【符号の説明】
１はワーク、１０は定盤、１１は溝、１２はセラミック板、１４は荷重回転軸、１５はタンク、１６はバルブ、１７は給液ノズル、１８はポンプである。[0001]
BACKGROUND OF THE INVENTION
The present invention is an aqueous system used when polishing various hard materials such as super hard metals, metals such as stainless steel and titanium, ceramics such as silicon carbide and gallium nitride, and electronic materials such as sapphire and crystallized glass. It relates to a polishing liquid.
[0002]
[Prior art]
The polishing of the hard material is performed by pressing the polishing pad against the polishing surface of the material with a constant load while applying a polishing liquid in which polishing abrasive grains are dispersed. Start with a small (grainy) abrasive grain and increase the count step by step. Recently, it has become possible to obtain diamond grains that are small in size, and it has become possible to efficiently finish polished surfaces with high flatness using diamond grains from the initial stage of polishing. . There are two types of polishing liquids, water-based and non-aqueous (oil-based), but water-based is mainly used because it is easy to handle.
[0003]
The polishing liquid used for such polishing is to uniformly disperse the abrasive grains and send them abundantly to the polishing surface, to lubricate between the polishing surface plate and the polishing surface, to generate frictional heat between the polishing surface plate and the polishing surface. It has a role of cooling. As conventional polishing processing liquids, for example, those containing alkylene glycol monoalkyl ethers and higher fatty acid salts thereof as described in Patent Document 1 are shown. Patent Document 2 describes a polishing liquid containing a glycol compound and a higher fatty acid metal salt.
[0004]
[Patent Document 1]
JP-A-8-287456 [Patent Document 2]
Japanese Patent Laid-Open No. 2000-141210
[Problems to be solved by the invention]
When a hard material such as stainless steel was polished with a polishing liquid of alkylene glycol and a higher fatty acid salt for a follow-up test by the inventors of the present application, the surface roughness of the polished surface was good, but slipping during polishing The result is that the polishing rate does not increase because of too good.
[0006]
The present invention was made in order to improve the conventional polishing liquid shown in Patent Document 1 and Patent Document 2, and can stably and uniformly disperse abrasive grains, and has good polishing ability and permeability. It is an object of the present invention to provide a polishing liquid with excellent frictional heat cooling efficiency.
[0007]
[Means for Solving the Problems]
The aqueous polishing liquid of the present invention made to achieve the above object includes oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, lactic acid, gluconic acid, malic acid, tartaric acid, citric acid, phthalate A carboxylate comprising at least one acid selected from acids, trimesic acid, and trimellitic acid, and at least one base selected from sodium, potassium, and ammonium;
At least one glycol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol having a molecular weight of 100 to 1000;
The aqueous solution containing any of the salt of phosphoric acid and pyrophosphoric acid,
Diamond abrasive grains having a particle diameter of 3 to 10 μm are dispersed.
[0008]
Examples of the alkylene glycol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol having a molecular weight of 100 to 1000.
[0009]
The proportion of the alkylene glycol in the mixed aqueous solution is preferably 1 to 90%, more preferably 20 to 40%. If it is less than 1%, the diamond abrasive grains tend to settle and the surface roughness of the polished surface becomes poor. If it is 90% or more, the viscosity becomes too high, and the solubility of other additives also deteriorates.
[0010]
Specific examples of the acid mosquitoes carboxylic acid salt, caprylic acid, pelargonic acid, monocarboxylic acids such as capric acid, oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, dicarboxylic acids such as sebacic acid, lactic acid, gluconic acid , Oxycarboxylic acids such as malic acid, tartaric acid and citric acid, aromatic carboxylic acids such as phthalic acid, trimesic acid and trimellitic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid and the like. Sodium as the base for mosquito carboxylic acid salts, potassium, ammonium, water soluble amines such as triethanolamine can be used. These acids and bases are arbitrarily combined.
It is preferable that any salt of phosphoric acid and pyrophosphoric acid is trisodium phosphate or potassium pyrophosphate.
[0011]
Mosquito carboxylic proportion of the aqueous polishing liquid of salt from 0.01 to 5% is preferred. If it is 0.01% or less, the polishing ability is low and the processing rate does not increase. Even if 5% or more is added, the polishing ability is not improved so much that it is wasted.
[0012]
The type of diamond abrasive particles dispersed in the aqueous polishing liquid may be either single crystal or polycrystalline, and natural or synthetic diamond can be used. The particle size is preferably 0.5 μm or more, more preferably 1 μm or more in order to improve the polishing ability and increase the processing rate. The larger the size, the higher the polishing ability. However, since the surface roughness of the polished surface increases, a particle size up to about 10 μm is usually used.
It is particularly preferable that diamond abrasive grains having a particle diameter of 3 to 10 μm are dispersed.
[0013]
The aqueous polishing liquid of the present invention may contain a rust inhibitor, a surfactant and a preservative in addition to the above components.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The aqueous polishing liquid of the present invention is prepared as follows. Dissolved alkylene glycol in purified water appropriate amount, to prepare a solution by dissolving it in mosquito carboxylic acid salt. A pure aqueous solution of phosphate is added to the aqueous solution, and other additive components such as a rust inhibitor are added, and then the concentration is adjusted with pure water to obtain a mixed aqueous solution. When diamond abrasive grains are added to this mixed aqueous solution and stirred at high speed with a mixer, the diamond abrasive grains are dispersed and suspended, and an aqueous polishing liquid is obtained.
[0015]
In addition, in order to obtain mixed aqueous solution, adding all components simultaneously to the whole amount of pure water is not a problem as long as the dissolution proceeds sufficiently. Further, in order to disperse the diamond abrasive grains, an ultrasonic disperser or a bead mill may be used together if necessary.
[0016]
The aqueous polishing liquid of the present invention is used when a hard material workpiece 1 is polished by a polishing machine as shown in FIG. A plurality of workpieces 1 are affixed to a ceramic plate 12 connected to the load rotation shaft 14 by wax. The load rotation shaft 14 is connected to a rotation drive source (not shown). The rotating surface plate 10 in which several circular grooves 11 are cut is connected to a rotational driving source with a receiving member (not shown). The aqueous polishing liquid is stored in the tank 15 and sprayed from the liquid supply nozzle 17 onto the rotating surface plate 10 through the valve 16 by a pipe pipe. It is sucked into the tank 15 by a pump 18 from a piping pipe connected to the lower drain of the receiving plate of the rotating surface plate 10. In this way, the water-based polishing fluid circulates from the tank 15 → the valve 16 → the sliding contact surface (polishing surface) of the work 1 and the polishing pad 13 → the drain (not shown) → the pump 18 → the tank 15.
[0017]
At the time of polishing, when the rotating surface plate 10 rotates and the ceramic plate 12 rotates, the workpiece 1 is brought into sliding contact with the rotating surface plate 10 while receiving a load. At this time, the water-based polishing liquid wets the surface of the rotating surface plate 10 while accumulating in the groove 11, so that a polishing function is achieved on the sliding contact surface between the workpiece 1 and the rotating surface plate 10.
[0018]
【Example】
Hereinafter, an example in which a water-based polishing liquid of an example to which the present invention is applied and a comparative example to which the present invention is not applied is made and subjected to polishing will be described.
[0019]
For reference, Example 1, Comparative Example 1, Example 2, Comparative Example 2, Example 3, Example 4, and Comparative Example 3, Comparative Example 4, and Comparative Example according to Table 2 5, Comparative Example 6, Comparative Example 7, Comparative Example 8, and Example 5 were prepared by the above-described procedure.
[0020]
[Table 1]

[0021]
[Table 2]

[0022]
Using the water-based polishing fluids produced in each example and comparative example, polishing was performed as follows with the polishing machine shown in FIG. SUS304 (5 mm × 5 mm) as a hard material workpiece test piece was affixed to the ceramic upper surface plate with wax using a pre-facing tin lower surface plate. While spraying 3 ml of aqueous polishing liquid every 30 seconds, a load of 36.5 kg was applied to the ceramic plate and polished at 60 rpm for 60 minutes.
[0023]
The polished surface of the test piece after polishing was measured with a surface roughness meter (Surfcom 590A manufactured by Tokyo Seimitsu Co., Ltd.). The processing rate was calculated from the weight difference before and after polishing the test piece. Data of surface roughness Ra (nm) and processing rate mg / mg are shown in Table 1 and Table 2 together. As is apparent from Tables 1 and 2, the surface roughness value of the polished surface using the aqueous polishing liquid of the present invention is small, and it can be seen that the processing rate, that is, the weight loss due to polishing under the same constant condition is large.
[0024]
【The invention's effect】
As described above in detail, the aqueous polishing liquid of the present invention can stably and uniformly disperse abrasive grains, has good polishing ability and permeability, and has excellent frictional heat cooling efficiency. Therefore, by using the aqueous polishing liquid of the present invention, the surface roughness of the polished surface becomes small. Further, the weight loss due to polishing is large, and polishing can be performed in a short time. That is, the water-based polishing liquid of the present invention greatly contributes to improvement of polishing accuracy and shortening of polishing time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a state of polishing by a polishing machine.
[Explanation of symbols]
1 is a work, 10 is a surface plate, 11 is a groove, 12 is a ceramic plate, 14 is a load rotating shaft, 15 is a tank, 16 is a valve, 17 is a liquid supply nozzle, and 18 is a pump.

Claims (3)

At least one acid selected from succinic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, lactic acid, gluconic acid, malic acid, tartaric acid, citric acid, phthalic acid, trimesic acid, and trimellitic acid; A carboxylate comprising at least one base selected from sodium, potassium, and ammonium;
At least one glycol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol having a molecular weight of 100 to 1000;
The aqueous solution containing any of the salt of phosphoric acid and pyrophosphoric acid,
An aqueous polishing liquid in which diamond abrasive grains having a particle diameter of 3 to 10 μm are dispersed. The aqueous polishing liquid according to claim 1 , wherein glycol in the aqueous solution is 1 to 90%, and the carboxylate in the processing liquid is 0.01 to 5% . The aqueous polishing liquid according to claim 1, wherein the salt of either phosphoric acid or pyrophosphoric acid is trisodium phosphate or potassium pyrophosphate .

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