JP2010180392A - Water-soluble working fluid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic water-soluble working fluid which is applicable to the cutting, grinding or polishing of metal members such as steel, alloy steel and aluminum, brittle materials such as quartz, silicon and ceramics, or composite materials such as vitreous carbon, exerts excellent lubricating properties even in high-load regions, brings about improvement in working speed, inhibits tool wear, thus attaining high productivity, and which is excellent in cost merit, contains neither mineral oil nor extreme pressure agents such as chlorine compounds and sulfur compounds and is extremely reduced in the contents of an oiliness improver and synthetic oil, thus lowering environmental loads. <P>SOLUTION: The water-soluble working fluid contains poly(meth)acrylamidoalkylcarboxylic acid or a (meth)acrylamidoalkylcarboxylic acid copolymer. Poly(meth)acrylamidododecanoic acid is exemplified as one example of the poly(meth)acrylamidoalkylcarboxylic acid. A copolymer of (meth)acrylamidododecanoic acid and acrylic acid is exemplified as one example of the (meth)acrylamidoalkylcarboxylic acid copolymer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-based lubricant, and more particularly to a water-soluble metalworking fluid used in cutting and grinding of metal members and brittle materials.

  Oils widely used in the cutting and grinding fields include water-insoluble oils containing mineral oil and water-soluble processing oils containing mineral oil, surfactants, organic amines, etc. and diluted in water. . As the water-soluble cutting fluid and the water-soluble grinding fluid, individual fluids were used according to the processing contents. However, from the viewpoint of preventing deterioration of the global environment or saving resources, there has been a demand for the development of oils that have a lower environmental impact than conventional oils and that can be used for as long as possible. Furthermore, with the recycling in mind, there has been a demand for an oil that can be used for both cutting and grinding.

  In view of this, synthetic type processing oils that do not contain mineral oil, have excellent rot resistance, and can be used for a long time have been proposed. Synthetic type (water-soluble) processing oil is composed of components that are completely soluble in water, and can be completely washed with water, so it has excellent cleanability, and no oil mist is generated, which is also effective in improving the workplace environment. Is shown. As such a water-soluble processing oil, for example, a lubricant composition (for example, Patent Document 1) using a polyoxyalkylene glycol compound as a base oil is known.

Furthermore, in recent years, there has been a demand for suppressing / preventing the reduction in the life of machining tools from the cost side, reducing machining defects from the production side, and improving the machining speed. Satisfactory performance is not obtained although oily agents such as vegetable oils, fatty acids and fatty acid esters (Patent Document 2) and extreme pressure agents containing chlorine and sulfur (Patent Document 3) are blended.
In addition, as the amount of the oil-based agent increases, problems such as degreasing, washing, acceleration of emulsification with sliding oil, and foaming occur.
Furthermore, examples of extreme pressure agents include chlorine-containing compounds, sulfur-containing compounds, and molybdenum-containing compounds. When used oil is incinerated, generation of chlorine gas, hydrogen chloride gas, sulfur oxide gas, etc. Arise. Molybdenum compounds, on the other hand, are subject to the PRTR law and must be strictly managed. From the viewpoint of saving resources and preventing environmental deterioration in recent years, those with less environmental pollution than conventional ones are desired. A water-soluble processing oil in which powder is dispersed has been studied (Patent Document 4).
On the other hand, polymer compounds such as poly (meth) acrylic acid derivatives and poly (meth) acrylamide derivatives are oil mist inhibitors (Patent Document 5), rust inhibitors, oil agents, extreme pressures in aqueous lubricants and processing oils. Improvement of agent (Patent Document 6), extrusion in cold region and hot region of aluminum alloy, lubricity at the time of plastic working such as press, releasability improver (Patent Document 7), sliding oil and hydraulic oil Etc. are utilized as an emulsification inhibitor (Patent Document 8). Polymer compounds such as polycarboxylic acids are also used as metal work compositions for metal cutting, grinding, and shaping (Patent Document 9).
The present invention has been achieved under the circumstances as described above.

Japanese Patent Laid-Open No. 10-324888 JP 2006-082278 A, JP 2004-224814 A JP 2005-187650 A JP 2004-182879 A Special table 2003-50769 gazette Japanese Patent Laid-Open No. 7-179876 Japanese Patent Laid-Open No. 11-50083 JP-A-4-277598 JP-T-2001-507724

  The present invention is excellent in lubricity even in a high load region in cutting and grinding of a brittle material such as steel, alloy steel, and aluminum, quartz, silicon, ceramics, carbon, etc. By preventing wear, it is highly productive and has excellent cost merit. Further, the content of mineral oil, oiliness agent and synthetic oil is reduced as much as possible, and it does not contain extreme pressure agents such as chlorine compounds and sulfur compounds. An object is to provide a low-synthetic water-soluble processing oil.

（式中、ＲはＨ若しくはＣＨ₃、ｎは５〜１１の整数を示す。）
を提供するものである。 As a result of research to solve such problems, the present inventors have found that the problem can be solved by blending a homopolymer or copolymer of (meth) acrylamide alkyl carboxylic acid into the metal working fluid, and the present invention Reached.
That is, the present invention
(1) A water-soluble processing oil containing a homopolymer of (meth) acrylamide alkyl carboxylic acid or a copolymer of (meth) acrylamide alkyl carboxylic acid and a vinyl monomer,
(2) The vinyl monomer contains at least one monomer selected from the group consisting of (meth) acrylic acid, (meth) acrylamide, N, N-diethylacrylamide, N, N-dimethylacrylamide, and N-isopropylacrylamide. The water-soluble processing oil according to (1) above,
(3) The water-soluble processing oil according to (1) or (2), wherein the (meth) acrylamide alkylcarboxylic acid is represented by the following general formula [1],

(In the formula, R represents H or CH ₃ , and n represents an integer of 5 to 11)
Is to provide.

  The water-soluble metalworking fluid of the present invention does not contain mineral oil, has no risk of fire, has excellent anti-corrosion properties, and can be completely washed with water, and further has no oil mist. It is also effective in improving the workplace environment. In addition, since the lubricity can be maintained even in a high load region, the wear of the processing tool can be reduced, the cost can be reduced, the production efficiency can be improved, and the environmental load is low because it does not contain a chlorine-based or sulfur-based extreme pressure agent.

Hereinafter, the present invention will be described in detail.
The present invention relates to cutting and grinding of brittle materials such as iron, steel, alloy steel, aluminum and the like, quartz, silicon, ceramics, carbon and the like containing a homopolymer or copolymer of (meth) acrylamide alkyl carboxylic acid It is related to water-soluble metalworking fluids for use in water and contains a homopolymer or copolymer of polyacrylamide alkyl carboxylic acid to improve the lubricity of metal cutting and grinding fluids. The reduction of the coefficient and the improvement of the load carrying capacity are realized.

  The homopolymer of poly (meth) acrylamide alkyl carboxylic acid of the present invention is a polymer obtained by polymerizing (meth) acrylamide alkyl carboxylic acid alone, and is hereinafter also referred to as poly (meth) acrylamide alkyl carboxylic acid. (Meth) acrylamide alkyl carboxylic acid has 4 or more carbon atoms in the alkyl group, and examples thereof include (meth) acrylamide hexanoic acid and (meth) acrylamide dodecanoic acid.

In the copolymer of the (meth) acrylamide alkylcarboxylic acid and vinyl monomer of the present invention, the vinyl monomer may be N-acryloylpiperidine, N-3-isopropoxypropyl (meth) acrylamide, N-8-acyloyl-1. , 4-Dioxa-8-azaspiro [
4,5] decane, N-1-methoxymethylpropyl (meth) acrylamide, (meth) acryloyl-L-proline methyl ester, N-2-methoxyethyl-Nn-propylacrylamide, N-2-methoxyethyl- N-isopropylacrylamide, N-methyl-Nn-propyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-methyl-N-isopropylacrylamide, N-3-ethoxypropyl (meth) acrylamide, N -Tetrahydrofurfuryl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-diethylacrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N-1-methyl-2-methoxyethyl (meth) acrylamide N-2-ethoxye Ru (meth) acrylamide, N-2-methoxyethyl-N-ethylacrylamide, N, N-bis (2-methoxyethyl) acrylamide, N-3-methoxypropyl (meth) acrylamide, N-cyclopropyl (meth) acrylamide N-ethyl (meth) acrylamide, N- (1,3-dioxolan-2-ylmethyl) -N-methylacrylamide, N-methyl-N-ethylacrylamide, N-acryloylpyrrolidine, N- (2,2-dimethoxy N) -substituted (meth) such as ethyl) -N-methylacrylamide, N-3- (2-methoxyethoxy) propyl (meth) acrylamide, N-hydroxymethylacrylamide, N-hydroxyethylacrylamide, and acrylamide compounds containing amino acid groups Acrylamide derivatives, N -N-vinyl substituted amide derivatives such as vinylcaprolactam, N-vinylisobutyramide, N-vinyl-N-methylacetamide, 2-morpholinoethyl (meth) acrylate, 2- (2-morpholinoethoxy) ethyl (meth) acrylate, 2-morpholinopropyl (meth) acrylate, morpholine tetraethyleneoxy (meth) acrylate, 3,5-dimethylmorpholine tetraethyleneoxy (meth) currate, methoxypolyethyleneglycol mono (meth) acrylate, methoxypolyethyleneglycol / polypropyleneglycolmono (meth) ) Acrylate, methoxypolyethyleneglycol / polybutyleneglycol mono (meth) acrylate, ethoxypolyethyleneglycol mono (meth) acrylate, ethoxypolyethylene Glycol / polypropylene glycol mono (meth) acrylate, ethoxy polyethylene glycol / polybutylene glycol mono (meth) acrylate, butoxypolyethylene glycol mono (meth) acrylate, phenoxypolyethylene glycol mono (meth) acrylate, benzyloxypolyethylene glycol mono (meth) Ester-type vinyl monomers such as acrylate and hydroxypropyl acrylate, ether-type vinyl monomers such as vinyl methyl ether, methoxyethyl vinyl ether, and ethoxyethyl vinyl ether, (meth) acrylic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, p-styrene sulfonic acid, vinyl sulfonic acid, ammonium salt, methallyl sulfonic acid, 2- (meth) a Various quaternary derivatives derived from anionic vinyl monomers such as liroyloxyethanesulfonic acid, mono (2- (meth) acryloyloxyethyl) acid phosphate, maleic acid and itaconic acid, and (meth) acrylate derivatives having a tertiary amino group Cationic vinyl monomers such as ammonium salts, various quaternary ammonium salts derived from (meth) acrylamide derivatives having tertiary amino groups, and molecules having various zwitterionic groups derived from (meth) acrylate derivatives having tertiary amino groups Inner salt-forming monomers, amphoteric vinyl monomers such as inner salt-forming monomers having various zwitterionic groups derived from (meth) acrylamide derivatives having tertiary amino groups, acrylamide derivatives containing amino acid salts, etc. (Meth) acrylic acid, ( Preferred are (meth) acrylamide, N, N-diethylacrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminopropylacrylamide, and acryloylmorpholine.

  As a ratio of the monomer constituting the copolymer, it is desirable that the ratio of the (meth) acrylamide alkyl carboxylic acid in the entire monomer to be polymerized is 20% or more by mass ratio.

The molecular weight of the poly (meth) acrylamide alkyl carboxylic acid or (meth) acrylamide alkyl carboxylic acid copolymer used in the present invention is 200 to 1,000,000, more preferably 1,000 to 100,000. When the molecular weight is 1 million or more, the solubility is lowered and the viscosity is extremely increased.
The polymer salt is preferably an alkali metal salt such as sodium or potassium, an ammonia neutralized salt, or an alkanolamine salt.

  The addition amount of the poly (meth) acrylamide alkyl carboxylic acid or the (meth) acrylamide alkyl carboxylic acid copolymer is 0.001 to 30 parts by weight, preferably 0.01 to 100 parts by weight of the working liquid in use. -3 parts by weight, more preferably 0.05-0.2 parts by weight. When the addition is less than 0.001 part by weight, improvement in lubricity is not observed, and when it is 30 parts by weight or more, not only the compatibility with other additives is lowered, but also the viscosity is increased, making the preparation difficult. Become.

  In the water-soluble metal working fluid of the present invention, if necessary, conventional additives such as metal rust preventives, oily agents, extreme pressure agents, antifoaming agents, nonferrous metal anticorrosives, antiseptics, and sequestering agents A surfactant can be included.

Examples of metal rust preventives include organic acids and alkali components.
[Monoalkylcarboxylic acid]
Acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, caproic acid, enanthic acid, capric acid, caprylic acid, undecanoic acid, undecylenic acid, dodecanoic acid, tridecanoic acid, Pentadecanoic acid, heptadecanoic acid, nonadecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, isostearic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, lactic acid, hydroxylauric acid , Hydroxymyristic acid, hydroxypalmitic acid, hydroxystearic acid, hydroxyarachidic acid, hydroxybehenic acid, hydroxyoctadecenoic acid, dodecyl succinic acid, lauryl succinic acid, stearyl succinic acid, isostearyl succinic acid, naphthenic acid Benzoic acid, para tertiary butyl benzoic acid, phthalic acid, salicylic acid
[Dicarboxylic acid]
Malic acid, citric acid, oxalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid and other organic carboxylic acids, and phosphoric acid, phosphonic acid Examples include acids and sulfonic acids.
Furthermore, you may use together inorganic type rust preventives, such as a phosphate, a silicate, bicarbonate.
Among them, monocarboxylic acids having 6 to 12 carbon atoms (hexanoic acid, caprylic acid, decanoic acid, lauric acid, etc.), dicarboxylic acids (eg azelaic acid, sebacic acid, dodecanedioic acid, etc.), or benzoic acid derivatives (tert-butylbenzoic acid) Acid, hydroxybenzoic acid, etc.), phosphoric acid and phosphonic acid derivatives are preferably ethylenediaminetetramethylenesulfonic acid and hydroxyethanediphosphonic acid.
Examples of the alkali component include alkali metal, ammonia, and alkanolamine. Examples of the alkali metal include sodium and potassium, and examples of the alkanolamine include monoethanolamine, mono (iso) propanolamine, monobutanolamine, diethanolamine, di (iso) propanolamine, dibutanolamine, and monoethanolmono (iso). Examples include propanolamine, monoethanol monobutanolamine, mono (iso) propanol monobutanolamine, triethanolamine, and triisopropanolamine.
These metal rust inhibitors need to maintain a pH of 8.0 to 12.0 when mixing an organic acid and an alkali component in order to obtain good rust prevention properties.

Examples of oily agents include fats and oils, long chain fatty acids having 8 to 36 carbon atoms, such as octylic acid, lauric acid, palmitic acid, oleic acid, stearic acid, and esters of these fatty acids and monohydric and polyhydric alcohols, For example, esters composed of octyl alcohol, lauryl alcohol, palmityl alcohol, oleyl alcohol, stearyl alcohol, or amides composed of alkylamine, such as amides composed of octylamine, laurylamine, palmitylamine, oleylamine, stearylamine Can be mentioned.
Examples of extreme pressure agents include zinc dioctyl dithiophosphate and dilauryl dipropionate.
As an antifoamer, a silicone type antifoamer and an organic type antifoamer are mentioned.

Non-ferrous metal anticorrosives include sodium metasilicate, sodium orthosilicate, 1,2,3-benzotriazole, 1- {N, N-bis (2-ethylhexyl) aminomethyl} benzotriazole, carboxybenzotriazole, mercapto Examples include benzothiazole.
In addition, a nonferrous metal anticorrosive agent can also use together 1 type, or 2 or more types.
Examples of preservatives include O-phenylphenol, benzothiazoline, and triazine compounds.

Examples of the sequestering agent include ethylenediaminetetraacetate, nitrilotriacetate, 1-hydroxyethylidene-1,1-diphosphonate, citrate and the like.
Examples of the surfactant include nonionic hydrocarbon surfactants such as polyoxyethylene alkyl ether and carboxylic acid alkanolamide.

  The processing oil of the present invention may be used as a processing liquid as it is, or a processing oil having a high concentration may be prepared and diluted with water (tap water) before use. When used diluted, the concentration of poly (meth) acrylamide alkyl carboxylic acid should not be 0.001% by weight or less, and the concentration should not hinder the effect of additives such as rust preventives. To.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example.

The method for evaluating lubricity is as follows.
<Lubricity evaluation conditions>
Apparatus: Wear test system (manufactured by JT Toshi Co., Ltd., model FPD-005 / 3000H-1X)
Test method: Iwata type 4 ball (steel ball material SUJ-2, 3/4)
Load: 300-5000N (step method, step width 300N)
Step time: 1 minute Sliding speed: 48 m / min

[Production Example 1]
Synthesis of polyacrylamide hexanoic acid 200 g of acrylamide hexanoic acid and 572 g of ethanol were added to a 1 L separable flask and dissolved by heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 28 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was poured into 2 L of water under stirring to obtain a candy-like precipitate. The precipitate was washed several times with a small amount of water and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of polyacrylamide hexanoic acid having a molecular weight of about 10,000 (GPC measurement).

[Production Example 2]
Synthesis of polyacrylamide undecanoic acid 200 g of acrylamide undecanoic acid and 580 g of ethanol were added to a 1 L separable flask and dissolved by heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 20 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of acetone under stirring to obtain a candy-like precipitate. The precipitate was washed several times with a small amount of acetone and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of polyacrylamide undecanoic acid having a molecular weight of about 30,000 (GPC measurement).

[Production Example 3]
Synthesis of polyacrylamide dodecanoic acid 200 g of acrylamide dodecanoic acid and 580 g of ethanol were added to a 1 L separable flask and dissolved by heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 20 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of acetone under stirring to obtain a candy-like precipitate. The precipitate was washed several times with a small amount of acetone and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of polyacrylamide dodecanoic acid having a molecular weight of about 40,000 (GPC measurement).

[Production Example 4]
Synthesis of Acrylamide Hexanoic Acid-Acrylic Acid Copolymer 100 g of acrylamide hexanoic acid, 100 g of acrylic acid and 572 g of ethanol were added to a 1 L separable flask and dissolved under heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 28 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of ethyl acetate under stirring to obtain a syrupy precipitate. The precipitate was washed several times with a small amount of ethyl acetate and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of acrylamide hexanoic acid-acrylic acid copolymer (hereinafter referred to as polyacrylamide hexanoic acid copolymer 1) having a molecular weight of about 30,000 (GPC measurement).

[Production Example 5]
Synthesis of Acrylamide Hexanoic Acid-N, N-Dimethylacrylamide Copolymer Add 80 g of acrylamide hexanoic acid, 120 g of N, N-dimethylacrylamide and 572 g of ethanol to a 1 L separable flask and dissolve by heating at 60 ° C. It was created. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 28 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of ethyl acetate under stirring to obtain a syrupy precipitate. The precipitate was washed several times with a small amount of ethyl acetate and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of acrylamide hexanoic acid-N, N-dimethyl acrylamide copolymer (hereinafter referred to as polyacrylamide hexanoic acid copolymer 2) having a molecular weight of about 30,000 (GPC measurement). It was.

[Production Example 6]
Synthesis of Acrylamide Dodecanoic Acid-Acrylic Acid Copolymer 100 g of acrylamide dodecanoic acid, 100 g of acrylic acid and 580 g of ethanol were added to a 1 L separable flask, and dissolved by heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 20 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of ethyl acetate under stirring to obtain a syrupy precipitate. The precipitate was washed several times with a small amount of ethyl acetate and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of an acrylamide dodecanoic acid-acrylic acid copolymer (hereinafter referred to as polyacrylamide dodecanoic acid copolymer 1) having a molecular weight of about 30,000 (GPC measurement).

[Production Example 7]
Synthesis of acrylamide dodecanoic acid-N, N-dimethylacrylamide copolymer 90 g of acrylamide dodecanoic acid, 110 g of N, N-dimethylacrylamide and 580 g of ethanol were added to a 1 L separable flask, and dissolved by heating at 60 ° C. Was made. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 20 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of acetone under stirring to obtain a candy-like precipitate. The precipitate was washed several times with a small amount of acetone and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of acrylamide dodecanoic acid-N, N-dimethylacrylamide copolymer (hereinafter referred to as polyacrylamide dodecanoic acid copolymer 2) having a molecular weight of about 40,000 (GPC measurement). It was.

[Production Example 8]
Synthesis of Acrylamide Dodecanoic Acid-N-Isopropylacrylamide Copolymer 80 g of acrylamide dodecanoic acid, 120 g of N-isopropylacrylamide and 580 g of ethanol were added to a 1 L separable flask and dissolved by heating at 60 ° C. to prepare a monomer solution. While the monomer preparation solution was stirred with a magnetic stirrer, nitrogen gas was bubbled for 1 hour while maintaining 60 ° C. Therefore, 20 g of a 5 wt% ethanol solution of 2,2′-azobis (2-methylpropionitrile) was added as a polymerization initiator and maintained at 60 ° C. for 10 hours.
The ethanol solution after the polymerization reaction was put into 2 L of acetone under stirring to obtain a candy-like precipitate. The precipitate was washed several times with a small amount of acetone and dried under reduced pressure at 60 ° C. The obtained solid was pulverized in a mortar to obtain a white powder of acrylamide dodecanoic acid-N-isopropylacrylamide copolymer (hereinafter referred to as polyacrylamide dodecanoic acid copolymer 3) having a molecular weight of about 40000 (GPC measurement).

[Example 1] [Example 2] [Example 3] [Example 4] [Example 5] [Example 6] [Example 7] [Example 8] [Comparative Example 1] [Comparative Example 2]
Using the polyacrylamide alkyl carboxylic acid or polyacrylamide hexanoic acid copolymer 1-2 or polyacrylamide dodecanoic acid copolymer 1-3 synthesized in Production Examples 1-8, the processing oil agent was prepared with the composition shown in Table 1. It prepared and it was set as the evaluation liquid.

[Comparative Example 3] [Comparative Example 4] [Comparative Example 5]
In Comparative Example 3, a water-soluble cutting fluid, Yushiroken FX-10 (manufactured by Yushiro), diluted 10 times with tap water was used as an evaluation solution.
In Comparative Example 4, a water-soluble cutting fluid, Cintilo 9974BF (manufactured by Castrol Co., Ltd.) diluted 10 times with tap water was used as an evaluation liquid.
In Comparative Example 5, a water-soluble cutting fluid, Sugicut CS-58XJ (manufactured by Sugimura Chemical Co., Ltd.) diluted 10 times with tap water was used as an evaluation solution.

Lubricity evaluation test Table 2 shows the measurement results of the friction coefficient and seizure load under the load of 600 N and 5000 N for the working fluids of Examples 1 to 8 and Comparative Examples 1 to 5.

The tool wear evaluation method is as follows.
<Processing equipment conditions>
Processing equipment: Lathe (made by Toyoka Sangyo, STRONG650)
Workpiece: S-45C (φ50mm, length 200mm)
Tool: TNMG160408MS, UTi20T (Mitsubishi Materials)
Processing conditions: cutting speed 150 m / min, feed 0.25 mm / rev, cutting 0.4 mm
Processing distance: 1500m
Liquid feed amount: 300 ml / min

<Tool wear evaluation equipment conditions>
Evaluation device: Microscope VHX-100 (KEYENCE)
Measurement conditions: x100 times

Tool Wear Evaluation Test With respect to the working fluids of Example 1 and Comparative Examples 2 and 3, the wear width of the tool flank at a working distance of 1500 m was evaluated.

According to Tables 2 and 3, it can be seen that the working fluids of Examples 1 to 8 do not seize even in a high load region compared to Comparative Example 1, exhibit good lubricity, and suppress tool wear.
Further, Comparative Examples 3 to 5 are commercially available general-purpose water-soluble metal working fluids, but Example 3 is not seized in a high load region, and the friction coefficient is low and good in each load region. It turns out that it shows lubricity and suppresses tool wear.

  As described above, the water-soluble processing liquid characterized by containing the polymer compound having the (meth) acrylamide alkyl carboxylic acid as a structural unit of the present invention does not seize even in a high load region and is good. Therefore, the wear of the tool can be reduced and the processing speed can be increased, so that the cost can be reduced and the production efficiency can be improved. In addition, the polymer compound of the present invention does not contain chlorine and sulfur elements, can reduce the amount of chlorine extreme pressure agent and oily agent added, and has a low environmental impact.

Claims (3)

  A water-soluble processing oil containing a homopolymer of (meth) acrylamide alkyl carboxylic acid or a copolymer of (meth) acrylamide alkyl carboxylic acid and a vinyl monomer.   The vinyl monomer includes one or more monomers selected from the group consisting of (meth) acrylic acid, (meth) acrylamide, N, N-diethylacrylamide, N, N-dimethylacrylamide, and N-isopropylacrylamide. 2. The water-soluble processing oil according to 1. The water-soluble processing oil according to claim 1 or 2, wherein the (meth) acrylamide alkylcarboxylic acid is represented by the following general formula [1].

(In the formula, R represents H or CH ₃ , and n represents an integer of 5 to 11)