JP2006249320A - Aqueous lubricant for machining and method for machining - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous lubricant for machining for preventing chips generated on processing expensive material such as jewel or noble metal from scattering and for effectively recovering them, and a method for carrying out machining work pieces using the lubricant. <P>SOLUTION: As the aqueous lubricant for machining comprises a thickener included therein and has high consistency, the lubricant itself is not scattered around even on carrying out cutting work of the work pieces. Therefore, chips taken in the lubricant are not scattered around. Therefore, the chips can be easily recovered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aqueous lubricant for machining and a machining method using the aqueous lubricant.

When cutting or grinding is performed on a work material such as metal, chips are always generated during processing. The shape and properties of the chips vary depending on the work material and the machining process, and the chips may be collected and reused, but generally they are not so valuable and are often discarded.
However, if the object to be processed is a high-priced substance such as a jewel or a precious metal, it is necessary to increase the recovery rate of the chips (gem powder or precious metal powder) to nearly 100%.

  Therefore, for example, as in Patent Document 1, an apparatus is known in which air nozzles are provided at a plurality of locations to blow away the chips generated by cutting the noble metal, and the chips are collected by a chip suction mechanism separately provided at a plurality of locations. It has been. According to this apparatus, the noble metal powder generated when cutting an expensive noble metal can be recovered.

Japanese Unexamined Patent Publication No. 7-314244

  However, in the collection device described in Patent Document 1, since the noble metal powder is blown off by air, the noble metal powder may be scattered around, and the noble metal powder cannot always be reliably collected by the suction mechanism.

  An object of the present invention is to provide a water-based lubricant for machining capable of preventing the scattering of chips generated when processing high-priced materials such as jewelry and precious metals and effectively recovering the same. An object of the present invention is to provide a method of machining a workpiece using an aqueous lubricant.

The water-based lubricant for machining according to the present invention is a water-based lubricant for machining which is used in machining and is removed by washing after the processing, wherein the water-based lubricant contains a thickener. And
Here, the water-based lubricant for machining is a liquid that exhibits a cooling and lubricating action when machining a workpiece (workpiece), and is also referred to as an aqueous coolant. Machining includes cutting, grinding, rolling and the like, and further includes polishing performed by adding fine abrasive grains for polishing.
Here, the aqueous lubricant means a lubricant having a moisture content of 20% by mass or more, preferably 50% by mass or more, and includes a uniform aqueous solution type and an emulsion type. This water content is a value at the time of use, and the concentrated liquid may be diluted with water to have a predetermined content rate.
In order to improve the lubricating action and the melting point lowering action, additives such as polyhydric alcohols, ethers and esters may be added to the aqueous lubricant for machining according to the present invention.

  According to the present invention, since the water-based lubricant for machining contains a thickener, the consistency thereof increases, and the lubricant does not scatter around even when the workpiece is machined or the like. . As a result, the chips taken in the lubricant are not scattered around. Accordingly, the chips can be easily collected together with the coolant. In particular, it is suitable when cutting is performed on expensive materials such as jewelry and precious metals. In addition, since it is an aqueous | water-based lubricant, a chip | tip can be collect | recovered easily only by wash | cleaning with water after machining.

In the present invention, it is preferable that the thickener described above is a water-soluble polymer.
According to the present invention, since the thickener is a water-soluble polymer, the water-soluble polymer can be dissolved in water, and the viscosity of the lubricant can be effectively increased.

In the present invention, the aforementioned water-soluble polymer is preferably mucin and / or poly-γ-glutamic acid.
Here, mucin is a polymer having a molecular weight of 1 to 10 million (glycoprotein) in which sugar and protein are bound, and is also called a viscous protein. Further, it is water-soluble and has a very high consistency when it contains water. This mucin exists in nature in a form containing water, and can be easily obtained from natto, taro, yam, nameko, okra, moroheiya and kelp. It can also be easily obtained from animals (such as bovine saliva). Poly-γ-glutamic acid is also a main component of the mucin described above, and is an essential component that imparts viscosity to an aqueous solution.

  According to the present invention, since the water-soluble polymer used as the thickener is mucin and / or poly-γ-glutamic acid, it can be dissolved in water to exhibit a very high consistency. Therefore, when the workpiece is cut or the like, the lubricant can further exhibit the aforementioned effects.

In this invention, it is preferable that the content rate of the thickener mentioned above is 0.1-30 mass%.
According to the present invention, since the content of the thickener is in a specific range, the viscosity of the lubricant is sufficiently increased, and the effect of easy cleaning after processing can also be exhibited. The effects of the invention can be more suitably exhibited.

The machining method of the present invention includes a step of providing the above-mentioned aqueous machining lubricant on a surface of a workpiece, a machining step of machining the workpiece provided with the aqueous machining lubricant, And a removing step for washing the aqueous machining lubricant adhering after the processing step.
According to the present invention, since the aqueous lubricant for machining has the above-described configuration, the above-described effects can be suitably achieved in the processing step and the lubricant removal step after processing. In particular, if water is used for cleaning, it is possible to easily clean the workpiece and collect chips.

The aqueous lubricant for machining according to the present invention includes a thickener.
Thickeners include amino acid derivatives such as N-lauroyl-L-glutamic acid, α, γ-di-n-butylamine, dextrin palmitate, dextrin stearate, dextrin 2-ethylhexanoate palmitate, etc. Fatty acid esters, sucrose fatty acid esters such as sucrose palmitate, sucrose stearate, benzylidene derivatives of sorbitol such as monobenzylidene sorbitol, dibenzylidene sorbitol, dimethylbenzyl dodecyl ammonium montmorillonite clay, dimethyl dioctadecyl ammonium montmorillonite clay, etc. Organic modified clay minerals, chondroitin sulfate, hyaluronic acid, mucin, poly-γ-glutamic acid, dermatan sulfate, heparin and keratan sulfate Mucopolysaccharides and salts thereof selected from: gum arabic, tragacanth, galactan, carob gum, guar gum, caraya gum, carrageenan, pectin, agar, quince seed, alge colloid, trant gum, locust bean gum, galactomannan, etc. Microbial polymers such as xanthan gum, dextran, succinoglucan and pullulan, animal polymers such as collagen, casein, albumin and gelatin, starch polymers such as starch, carboxymethyl starch and methylhydroxypropyl starch, methylcellulose and ethylcellulose , Methyl hydroxypropyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxypropyl cellulose, nitrocellulose, cellulose sulfate sodium Cellulose polymers such as sodium, carboxymethylcellulose sodium, crystalline cellulose, cellulose powder, alginic acid polymers such as sodium alginate and propylene glycol alginate, vinyl polymers such as polyvinyl methyl ether, carboxyvinyl polymer, and alkyl-modified carboxyvinyl polymer , Polyoxyethylene polymer, polyoxyethylene polyoxypropylene copolymer polymer, acrylic polymer such as sodium polyacrylate, polyethyl acrylate, polyacrylamide, polyethyleneimine, cationic polymer, bentonite, laponite, hectorite Inorganic water-soluble polymers such as Also included are film forming agents such as polyvinyl alcohol and polyvinyl pyrrolidone.

Among these, water-soluble polymers such as mucin and poly-γ-glutamic acid are preferable in terms of their viscosity imparting function. This mucin exists in nature in a form containing water, and can be easily obtained from natto, taro, yam, nameko, okra, moroheiya and kelp.
Poly-γ-glutamic acid, which is a viscosity-imparting compound that constitutes mucin, is also readily available.

  Moreover, in order to provide sufficient consistency, the content of the thickener is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably with respect to the entire lubricant. 1% by mass or more. However, if it exceeds 30% by mass, the viscosity of the liquid becomes too high, and machining itself and the operation of removing the lubricant from the workpiece after processing become somewhat difficult. Therefore, the content of the thickener is preferably 20% by mass or less, and more preferably 10% by mass or less.

  Various water-soluble substances may be dissolved in the aqueous lubricant for machining according to the present invention. Examples of the water-soluble substance include nonionic surfactants, fatty acid polyoxyethylene esters, ethylene glycol, tetramethylene glycol, diethylene glycol, propylene glycol and the like. Among these, ethylene glycol is widely used as a component of antifreeze and can be suitably used in the present invention. These contents are preferably 5% by mass or less based on the entire lubricant of the present invention. In addition, when manufacturing the aqueous | water-based lubricant for machining of this invention, 20 to 50 times of water may be added to these concentrated liquids, and a density | concentration may be adjusted finally.

  Further, if necessary, a water-soluble polyether, a hydrocarbon-based lubricating oil, an emulsifier, an extreme pressure agent, an oily agent, a rust preventive agent and the like may be appropriately added and used. These may use 1 type (s) or 2 or more types.

  Examples of the water-soluble polyether include polyethylene glycol having a number average molecular weight of 500 to 20,000, PO block adduct of polyethylene glycol, EO / PO random adduct of dihydric alcohol (20 to 40 mol addition), or glycerin, Examples include EO / PO random addition (20 to 100 mol addition) isomers of 3-6 valent polyhydric alcohols such as sorbitol. The content of the water-soluble polyether is preferably 5% by mass or less based on the entire lubricant of the present invention.

  Examples of the hydrocarbon-based lubricating oil include solvent refined oil, paraffinic mineral oil, naphthenic mineral oil, poly-α-olefin (weight average molecular weight 200 to 4,000), polybutene (weight average molecular weight 200 to 4,000), and the like. It is done. Of these, solvent refined oil, paraffinic mineral oil, and naphthenic mineral oil are preferred. The content of the hydrocarbon-based lubricating oil is preferably 7% by mass or less with respect to the entire lubricant of the present invention.

  Examples of the emulsifier include Na and K salts of sulfonic acids having 10 to 40 carbon atoms (alkylbenzene sulfonic acid, petroleum sulfonic acid, alkylnaphthalene sulfonic acid, etc.), fatty acids having 8 to 22 carbon atoms (palmitic acid, myristic acid, Oleic acid, castor oil fatty acid, etc.) Na, K salts, etc., PEG esters obtained by esterifying these fatty acids and polyethylene glycols having a number average molecular weight of 500-5,000, and alcohols having 8-24 carbon atoms (octyl alcohol, decyl alcohol) , Dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, oleyl alcohol, stearyl alcohol, etc.), a nonionic active agent obtained by adding 2 to 40 moles of ethylene oxide, sorbitan fatty acid ester and these ethylene oxides. Such as a non-ionic active agents 40 mols and the like. The amount of the emulsifier used is preferably 3% by mass or less based on the entire lubricant of the present invention.

  Extreme pressure agents include dialkyl (C1-36) zinc dithiophosphates such as zinc dioctyl dithiophosphate and zinc diallyl dithiophosphate; organic sulfides having 3 to 60 carbon atoms such as dilauryl thiodipropionate and tetrakis [methylene-3 -(Dodecylthio) propionate] methane and the like. The amount of the extreme pressure agent used is preferably 0.5% by mass or less based on the entire lubricant of the present invention.

  Examples of the oily agent include amine salts or alkali metal salts of fatty acids having 8 to 22 carbon atoms, alkali metal salts of alkyl phosphate esters having 8 to 22 carbon atoms, and fatty acids having 8 to 22 carbon atoms and 8 to 22 carbon atoms. Monohydric alcohol or polyhydric alcohol having 2 to 6 or more valences (ethylene glycol, propylene glycol, hexylene glycol, glycerin, neopentyl alcohol, pentaerythritol, etc.), animal and vegetable oils, and the like. The amount of the oily agent used is preferably 2% by mass or less based on the entire lubricant of the present invention.

  Examples of the rust preventive include organic amines having 2 to 36 carbon atoms (aliphatic amines such as butylamine, octylamine, laurylamine, oleylamine; alicyclic amines such as cyclohexylamine; heterocyclic amines such as morpholine; C6-C36 aliphatic carboxylic acid amide (caprylic acid, lauric acid, nonanoic acid, decanoic acid, oleic acid amide, etc.); C6-C24 dibasic acid amide (azelaic acid, sebacic acid, dodecane 2) Acid, dimer acid amide, etc.); C6-C36 alkenyl succinic acid amide (octenyl succinic acid, dodecenyl succinic acid, pentadecenyl succinic acid, amide of octadecenyl succinic acid, etc.); aromatic carboxylic acid amide ( Benzoic acid, p-tert-butylbenzoic acid, nitrobenzoic acid amide, etc.); cyclohexyla Benzotriazole, mercaptobenzothiazole, N, N′-disalicylidene-1,2-diaminopropane, alizarin, etc. Examples of amines that are constituents of the amide include the amines and ammonia described above. The amount of the rust inhibitor used is preferably 1% by mass or less based on the entire lubricant of the present invention.

  Each of the above-mentioned additives can be mixed with the lubricant of the present invention by a conventionally known mixing device if necessary. The mixing conditions are not particularly limited, but the mixing conditions are preferably obtained easily by mixing at 0 to 30 ° C. for 0.5 to 3 hours. Of course, these concentrated liquids may be diluted with water.

According to such a water-based lubricant for machining according to the present invention, since the thickener is included, the consistency of the lubricant can be effectively increased.
Therefore, even when the workpiece is cut or the like, the lubricant itself does not scatter around. As a result, the chips taken in the lubricant are not scattered around. Therefore, the chips can be easily recovered together with the lubricant. In particular, it is suitable when cutting is performed on expensive materials such as jewelry and precious metals. Further, since this aqueous machining lubricant is water-based, it is possible to easily collect chips just by washing with water.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention. In addition, the specific structure, shape, and the like when carrying out the present invention may be other structures and the like as long as the object of the present invention can be achieved.

For example, in the above-described embodiment, abrasive grains are not added to the lubricant, but it is also possible to add abrasive grains and use the so-called polishing liquid (abrasive).
Here, examples of the abrasive grains include inorganic particles and organic particles. Examples of the inorganic particles include particles of components such as silicon dioxide, zirconium oxide, titanium oxide, silicon nitride, silicon carbide, and manganese dioxide. Of these, particles of silicon dioxide known as fumed silica and colloidal silica are preferable, and colloidal silica is particularly preferable. Colloidal silica is less likely to precipitate during storage, has a uniform particle size, and is less susceptible to scratches and scratches on the surface of the workpiece (workpiece).

  Further, fine powder of boron nitride (BN) can also be used as abrasive grains. Examples of boron nitride (BN) include amorphous boron nitride (a-BN), hexagonal boron nitride (h-BN) having a structure in which hexagonal mesh layers are stacked in a two-layer cycle, hexagonal boron nitride, Rhombohedral boron nitride (r-BN) having a structure in which a network layer is laminated in a three-layer cycle, boron nitride (t-BN) having a random layer structure in which hexagonal network layers are randomly laminated, and cubic nitriding in a high-pressure phase Boron (c-BN) is known.

  The organic particle is not particularly limited as long as it is a particle mainly composed of an organic polymer compound. For example, methacrylic resin such as PMMA, organic polymer compound such as phenol resin, melamine resin, polystyrene resin, and polycarbonate resin, emulsion polymerization Vinyl compound polymers obtained by the above, or ion exchange resins and chelate resins having the ability to adsorb specific metals.

  The organic lubricant for machining according to the present invention may contain both organic particles and inorganic particles, or each may contain alone. Of these, colloidal silica is particularly preferred.

The average particle diameter of the abrasive grains is preferably in the range of 0.005 to 10 μm, and more preferably in the range of 0.005 to 1.0 μm.
If the particle diameter exceeds 10 μm, the surface after polishing tends to be rough or scratches tend to occur, and if it is less than 0.005 μm, the polishing rate tends to decrease. In addition, it is desirable to use those abrasive grains having a uniform particle diameter as much as possible, but it is also possible to mix and use abrasive grains having a plurality of particle diameters as necessary. For example, it is possible to arbitrarily mix and use abrasive grains having an average particle diameter of 0.1 μm and 1.0 μm.

  According to such an aqueous lubricant for machining containing abrasive grains, in the local polishing with a predetermined amount of polishing liquid adhered, the polishing liquid does not scatter, so the abrasive grains do not scatter, Local polishing can be efficiently performed with a small amount of polishing liquid. Therefore, it is suitable for local polishing of expensive noble metals and the like.

  The following examples further illustrate the invention, but the invention is not limited thereto.

(1) Preparation of aqueous lubricant for machining A 5 mass% aqueous solution (aqueous coolant) of Meiji γ-PGA (poly-γ-glutamic acid manufactured by Meiji Seika Co., Ltd.) was prepared and used as a product of the present invention. Further, pure water that does not dissolve poly-γ-glutamic acid was used as a comparative product.

(2) Aqueous Lubricant Scattering Test For each sample of the product of the present invention and the comparative product, the scattering property (scattering prevention property) of the aqueous lubricant was confirmed under the following conditions.
[Test conditions]
・ Used machine: Cutting machine (VR0222L TYPE MIZ manufactured by Toshiba Machine Co., Ltd.)
・ Processing shape: processing depth 0.5mm, groove width 0.1mm
・ Tool used: Ball end mill φ1 (0.05R)
・ Work material: Platinum plate 5mm × 50mm × 50mm

[Test method]
The cutting situation is schematically shown in FIGS.
First, the aqueous lubricant 3 was dropped onto the surface of the work 2 with a dropper, and the droplet was brought into close contact with the surface of the work in a substantially hemispherical shape. Next, while rotating the rotary blade 1 of the cutting tool at a high speed of 150,000 revolutions per minute at the center, the workpiece 2 is cut to the predetermined depth described above (FIG. 1), and then in the horizontal direction. Moved 0.5 mm at a speed of 250 mm per minute (FIGS. 2 and 3).

[result]
The water-based lubricant 3 of the present invention has a substantially hemispherical shape as shown in FIG. 1, and even if the rotary blade 1 is moved in the horizontal direction, it moves following the tip of the rotary blade 1 while maintaining its shape ( Figure 2). Further, in the aqueous lubricant 3, the cut chips (platinum powder) 4 remained as they were. Thereafter, the aqueous lubricant 3 was recovered and washed with water, whereby the chip (platinum powder) 4 could be easily recovered.
On the other hand, in the comparative aqueous lubricant 3, when the rotary blade 1 of the tool rotates, the viscosity of the aqueous lubricant 3 is low, so that the liquid splatters violently and follows the tip of the rotary blade 1. Was slight (FIG. 3). Therefore, it has been difficult to recover the chips (platinum powder) 4.

  The water-based lubricant for machining of the present invention can be suitably used for machining as cutting oil, grinding oil, polishing oil, rolling oil, drawing oil, press oil, and the like. In particular, it can be suitably used for cutting and grinding precious metals and gemstones.

The schematic diagram of the cutting condition which concerns on the Example of this invention (the cutting condition of a rotary blade) Schematic diagram of cutting situation according to an embodiment of the present invention (product of the present invention) Schematic diagram of cutting situation according to an embodiment of the present invention (comparative product)

Explanation of symbols

1 ... Rotating blade 2 ... Work material
3 ... Water-based lubricant 4 ... Chip

Claims (5)

A water-based lubricant for machining that is used in machining and is removed by washing after the machining,
An aqueous lubricant for machining, wherein the aqueous lubricant contains a thickener. The aqueous lubricant for machining according to claim 1,
A water-based lubricant for machining, wherein the thickener is a water-soluble polymer. The aqueous lubricant for machining according to claim 2,
An aqueous lubricant for machining, wherein the water-soluble polymer is mucin and / or poly-γ-glutamic acid. In the water-based lubricant for machining according to any one of claims 1 to 3,
An aqueous lubricant for machining, wherein the content of the thickener is 0.1 to 30% by mass. Providing the machining water-based lubricant according to any one of claims 1 to 4 on the surface of the workpiece;
A machining step of machining a workpiece provided with the aqueous machining lubricant;
And a removing step for washing the aqueous machining lubricant adhering after the machining step.

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