JP2008037928A - Lubricating oil for cold rolling oil for steel sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil for cold rolling oil for steel sheet satisfying lubricating performance, washability and accumulated scum reducing property including low temperature atmosphere in high speed rolling, especially in continuous high speed rolling. <P>SOLUTION: The lubricating oil for cold rolling oil for steel sheet comprises (a) 3-20 wt.%. of a mineral oil and at least one kind of monoesters obtained from 12-22C aliphatic carboxylic acid and 1-12C aliphatic alcohol, (b) 55-85 wt.%. of oils and fats, (c) 5-20 wt.%. of composite esters obtained by esterification of a residual carboxyl group or hydroxyl group of a partial ester which is obtained from at least one selected from a group comprising a 16-22C dimer acid and polymer acid and polyols, with a monovalent alcohol or a monovalent aliphatic acid, and (d) 0.1-3%.wt. of a water soluble macromolecular compound including a specific amino based monomer and having 10,000-1,000,000 of weight average molecular weight. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubricating oil for steel sheet cold rolling oil. Moreover, this invention relates to the cold rolling oil for steel plates using the said lubricating oil for steel plate cold rolling oil. Furthermore, this invention relates to the manufacturing method of the cold rolled steel plate using the said cold rolled oil for steel plates.

  In cold rolling of steel sheets, rapid progress in rolling equipment and rolling technology in recent years has led to higher rolling speeds and mass production, and the required performance for the rolling oil used has long-term circulation stability and high lubricity (rolling) ), Ease of liquid management, wastewater treatment, etc. are becoming increasingly severe.

  As a factor hindering such required performance, lack of lubricity during high-speed production of cold-rolled steel sheets and a large amount of scum derived from rolling oil associated with high-speed productivity are known, and the invention aims to improve it Has been proposed. For example, Patent Document 1 discloses a rolling oil containing a complex ester and a polymer dispersant, and Patent Document 2 discloses a rolling oil containing a complex ester and specific fats and oils.

Japanese Patent No. 3096289 JP 2004-204214 A

  However, the rolling oil disclosed in Patent Document 1 is effective in reducing accumulated scum when the rolling roll is difficult to wear as in the batch rolling method, but exceeds 1800 m / min as in the continuous rolling method. It has been found that the lubricity when the rolling roll is worn by continuous rolling at high speed is not sufficient, and the washability at a steel plate temperature exceeding 150 ° C. after the rolling is insufficient.

  Further, the rolling oil disclosed in Patent Document 2 solves the problems of lubricity during high-speed rolling when the rolling roll is worn and the washability when the steel plate temperature after rolling during high-speed drawing is 150 ° C. or higher. Although it was possible, rolling oil and scum accumulation around the mill when the ambient temperature around the mill was less than 5 ° C. could not be said to be sufficient.

  It is an object of the present invention to provide a lubricating oil for steel sheet cold rolling oil that is capable of satisfying the lubrication property, the washability, and the reduction in accumulated scum including the low temperature atmosphere under high speed rolling, particularly in the continuous high speed rolling method. And Moreover, this invention makes it a subject to provide the cold rolling oil for steel plates using the said lubricating oil for steel plate cold rolling oil. Furthermore, this invention makes it a subject to provide the manufacturing method of the cold rolled steel plate using the said cold rolled oil for steel plates.

In the present invention, 3 to 20 selected from the group consisting of (a) mineral oil, and a monoester obtained from an aliphatic carboxylic acid having 12 to 22 carbon atoms and an aliphatic alcohol having 1 to 12 carbon atoms. weight%,
(B) 55 to 85% by weight of fats and oils having an iodine value of 25 to 50 (I ₂ g / 100 g),
(C) The remaining carboxyl group or hydroxyl group of the partial ester obtained from one or more selected from the group consisting of dimer acids and polymer acids of higher aliphatic unsaturated acids having 16 to 20 carbon atoms and polyols has 12 carbon atoms. 5 to 20% by weight of a complex ester having a weight average molecular weight of 750 to 20000, which is esterified with a monohydric alcohol or monohydric fatty acid of ˜22 and having an iodine value of 50 (I ₂ g / 100 g) or less, and (d) ( d1) General formula (1):

(Wherein R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ represent an alkyl group having 1 to ³ carbon atoms, A represents —O— or —NH—, and m represents an integer of 1 to 3). ), A homopolymer containing a structural unit derived from a monomer or a salt thereof, (d2) a copolymer containing a structural unit derived from two or more of the monomers, (d3) It is a polymer selected from one or more and a copolymer comprising (meth) acrylic acid, a salt thereof, an alkyl ester or a structural unit derived from one or more of the alkylamide, and the weight average molecular weight is 10,000 to 1,000,000. The present invention relates to a lubricating oil for steel sheet cold rolling oil containing 0.1 to 3% by weight of one or more water-soluble polymer compounds in the range of

  Moreover, this invention relates to the cold rolling oil for steel plates containing the said lubricating oil for steel plate cold rolling oil, and water.

Furthermore, the present invention is a method for producing a cold rolled steel sheet comprising a step of rolling a steel sheet with a cold rolling mill while supplying cold rolling oil for the steel sheet,
The present invention relates to a method for producing a cold rolled steel sheet, wherein the cold rolled oil for steel sheet is used as the cold rolled oil for steel sheet, and the cold rolled oil for steel sheet is circulated and used.

  INDUSTRIAL APPLICABILITY The present invention can provide a lubricating oil for steel sheet cold rolling oil that can satisfy lubrication, washability and deposition scum reduction including low temperature atmosphere under high-speed rolling, particularly in a continuous high-speed rolling system. . Moreover, this invention can provide the cold rolling oil for steel plates using the said lubricating oil for steel plate cold rolling oil. Furthermore, this invention can provide the manufacturing method of the cold rolled steel plate using the said cold rolled oil for steel plates.

As described above, the lubricating oil for steel sheet cold rolling oil of the present invention is a monoester obtained from (a) mineral oil, an aliphatic carboxylic acid having 12 to 22 carbon atoms, and an aliphatic alcohol having 1 to 12 carbon atoms. 3 to 20% by weight of one or more selected from the group consisting of
(B) 55 to 85% by weight of fats and oils having an iodine value of 25 to 50 (I ₂ g / 100 g),
(C) The remaining carboxyl group or hydroxyl group of the partial ester obtained from one or more selected from the group consisting of dimer acids and polymer acids of higher aliphatic unsaturated acids having 16 to 20 carbon atoms and polyols has 12 carbon atoms. 5 to 20% by weight of a complex ester having a weight average molecular weight of 750 to 20000, which is esterified with a monohydric alcohol or monohydric fatty acid of ˜22 and having an iodine value of 50 (I ₂ g / 100 g) or less, and (d) ( d1) General formula (1):

(Wherein R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ represent an alkyl group having 1 to ³ carbon atoms, A represents —O— or —NH—, and m represents an integer of 1 to 3). ), A homopolymer containing a structural unit derived from a monomer or a salt thereof, (d2) a copolymer containing a structural unit derived from two or more of the monomers, (d3) It is a polymer selected from one or more and a copolymer comprising (meth) acrylic acid, a salt thereof, an alkyl ester or a structural unit derived from one or more of the alkylamide, and the weight average molecular weight is 10,000 to 1,000,000. 0.1 to 3% by weight of one or more water-soluble polymer compounds in the range of

  The component (a) contributes to scum solubility and has an effect of improving the cleanliness around the mill.

  Examples of the mineral oil as component (a) include spindle oil, machine oil, turbine oil, cylinder oil, and neutral oil. From the viewpoint of heat resistance and lubricity, paraffinic mineral oil is more preferable. The viscosity of the mineral oil is preferably 30 cSt (40 ° C.) or less from the viewpoint of improving the cleanability around the mill.

  The monoester of component (a) is obtained from a higher fatty acid having 12 to 22 carbon atoms and an aliphatic monohydric alcohol having 1 to 12 carbon atoms. For example, methyl stearate, butyl stearate, 2 ethyl Hexyl stearate, isodecyl stearate, lauryl stearate, methyl oleate, isodecyl oleate, butyl palmitate, methyl behenate, methyl ester of beef tallow fatty acid, butyl ester of palm oil fatty acid, 2-ethylhexyl ester of palm oil fatty acid, palm oil Typical examples include fatty acid lauryl esters. These monoesters contribute to scum solubility like mineral oil, and have an effect of improving cleanability around the mill.

  The component (a) is preferably a monoester from the viewpoint of heat resistance and scum solubility. When the carbon number of the aliphatic carboxylic acid used in the monoester is 22 and the carbon number of the aliphatic alcohol is greater than 12, the scum solubility tends to decrease, and when the aliphatic carboxylic acid has a carbon number of less than 12 There is a tendency for lubricity to decrease. The carbon number of the aliphatic carboxylic acid is preferably 12-22, and the carbon number of the aliphatic alcohol is preferably 4-10.

  These mineral oils and monoesters as component (a) may be used alone or in combination of two. Component (a) is used in an amount of 3 to 20% by weight based on the total amount of the lubricating oil. When the amount added is 20% by weight or less, the lubricity is good and more than 3% by weight. In this case, the scum solubility is excellent, and the effect of improving the cleanliness around the mill is exhibited, which is preferable. From the balance between cleanliness around the mill and lubricity, the amount of component (a) added is more preferably in the range of 5 to 15% by weight.

(B) component of the present invention are fats and oils having an iodine value is _{25~50 (I 2 g / 100g)} . The component (b) has a relatively low iodine value of 50 (I ₂ g / 100 g) or less among the oils and fats conventionally used in steel sheet cold rolling oil, and the thermal deterioration of the steel sheet rolling oil is relatively low. Since it does not occur easily, it has an effect of suppressing a decrease in washability during high-speed rolling. On the other hand, the component (b) having an iodine value of 25 (I ₂ g / 100 g) or more can reduce the accumulation of rolling oil around the mill even in a low temperature atmosphere. The iodine value of the component (b) is preferably 30 to 45 (I ₂ g / 100 g) from the viewpoint of lubricity, washability, and ability to reduce accumulated scum including low temperature atmosphere. Oils and fats may be natural or synthetic. (B) Component fats and oils such as beef tallow, pork tallow, rapeseed oil, castor oil, palm oil, coconut oil, etc., and having an iodine value of 25 to 50 (I ₂ g / 100 g) Is preferably selected.

  Although the fats and oils which are the said (b) component may be 1 type, they can also be used in mixture of 2 or more types. Component (b) is preferably added in an amount of 55 to 85% by weight based on the total components of the lubricating oil from the viewpoint of improving the washability during high-speed rolling. (B) It is preferable that the addition amount of a component is 60 to 80 weight% of all the components of lubricating oil.

  (C) Component complex esters are preferred in terms of reducing accumulated scum, including under low-temperature atmosphere, and have a larger number of ester groups and higher kinematic viscosity than oils and fats such as beef tallow conventionally used as a lubricating component. Has significant lubricity improvement effect.

The complex ester as the component (c) of the present invention is a partial ester obtained from one or more selected from the group consisting of dimer acids and polymer acids of higher aliphatic unsaturated acids having 16 to 20 carbon atoms and polyols. The remaining carboxyl group or hydroxyl group is an ester compound with a monohydric alcohol or monovalent fatty acid having 12 to 22 carbon atoms, has an iodine value of 50 (I ₂ g / 100 g) or less, and has a weight average molecular weight of 750 to 20000. It is. When the molecular weight is 750 or more, the lubricity is superior to oils and fats, and when it is 20000 or less, the solubility in the lubricating component is good and the handling property is also good in terms of viscosity. The molecular weight is more preferably 1000 to 10,000, and most preferably 1500 to 4000. In addition, the weight average molecular weight of (c) component is measured by the gel permeation chromatography (GPC) method of the following conditions.

(conditions)
Column: G2000HXL + G1000HXL (manufactured by Tosoh Corporation)
-Column temperature: 40 ° C
・ Eluent: THF (tetrahydrofuran)
・ Detector: RI (refractometer)
Injection volume: 3 wt% THF solution, 20 μl
Liquid flow rate: 1.0 ml / min
・ Molecular weight standard: Polystyrene

  The dimer acid and polymer acid used for the production of the component (c) are higher aliphatic monoenoic acid or dienoic acid dimer acid and polymer acid having 16 to 20 carbon atoms, or hydrogenated products thereof such as zomarinic acid and oleic acid. , Linoleic acid, dimer acid and polymer acid of tall oil fatty acid, or hydrogenated products thereof. Examples of the polyols include propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, neopentyl glycol, butanediol, pentanediol, polyoxyethylene glycol, polyoxypropylene glycol, trimethylolpropane, pentaerythritol, and glycerin. . Examples of the monohydric alcohol having 12 to 22 carbon atoms include lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, oleyl alcohol and the like. Examples of the monovalent fatty acid having 12 to 22 carbon atoms include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, erucic acid, beef tallow fatty acid, palm oil fatty acid, coconut oil fatty acid and the like. .

The complex ester as component (c) is controlled to have an iodine value of 50 (I ₂ g / 100 g) or less from the viewpoint of washability. The iodine value of the component (c) is preferably 45 (I ₂ g / 100 g) or less, and more preferably 40 (I ₂ g / 100 g) or less. The iodine value of the component (c) can be controlled by selecting materials used for the production of the complex esters and adjusting the weight average molecular weight. Complex esters as component (c), from the viewpoint of lubricity improving effect, 40 kinematic viscosity ℃ is 400 mm ² / sec or more, and a more a complex ester of more than 750 mm ² / sec. In general, the complex ester as the component (c) preferably has an acid value of 10 mgKOH / g or less and a hydroxyl value of 10 mgKOH / g or less.

  Although 1 type may be sufficient as the complex ester which is the said (c) component, 2 or more types can be mixed and used. Component (c) is added in an amount of 5 to 20% by weight of the total components of the lubricating oil from the viewpoints of lubricity, washability, and deposited scum reduction including low temperature atmosphere. Furthermore, the addition amount of the component (c) is preferably 6 to 18% by weight of the total components of the lubricating oil.

  Further, the ratio (b) / (c) of the component (b) to the component (c) is 3/1 to 15 in terms of weight ratio from the viewpoint of lubricity, washability, and deposited scum reduction including low temperature atmosphere. / 1, more preferably 7/2 to 12/1.

  The component (d) of the present invention is necessary for ensuring long-term circulation stability related to the lubricity of the lubricating oil of the present invention. The mechanism of action is estimated as follows. Although the surface potential of the rolling oil particles is negative, the surface potential of the rolling oil particles becomes almost zero as the component (d) is added, and the rolling oil particles are aggregated to become a coarse particle diameter. It exhibits excellent lubricity. When the component (d) is further added, the surface potential of the rolled oil particles becomes positive and the protective colloid action makes the rolled oil particles have a large particle size and good emulsification dispersibility, so that the plate-out property is good and excellent. It exhibits excellent lubricity and long-term circulation stability. (D) It is necessary not to add the component excessively in order to maintain the rolling oil particle diameter at an appropriate size and to ensure both the emulsifying dispersibility and the plate-out property.

The polymer compound of the component (d) used in the lubricating oil for cold rolling oil of the present invention is
(D1) A water-soluble polymer compound comprising a monomer represented by the general formula (1) or a structural unit derived from a salt thereof and having a weight average molecular weight in the range of 10,000 to 1,000,000;
(D2) Two or more kinds of copolymers containing a structural unit derived from the monomer represented by the general formula (1) or a salt thereof, and having a weight average molecular weight in the range of 10,000 to 1,000,000. Molecular compounds;
(D3) A structural unit derived from one or more of the monomer represented by the general formula (1) or a salt thereof, and one or more of acrylic acid, methacrylic acid, a salt thereof, an alkyl ester thereof, and an alkyl amide thereof. 1 or more selected from water-soluble polymer compounds having a weight average molecular weight in the range of 10,000 to 1,000,000. (D1) to (d3) have each essential constituent unit as a main component, but other units that can be copolymerized with the monomer from which these constituent units are derived, as long as the effects of the present invention are not impaired. A structural unit derived from a monomer can be contained. The constituent unit derived from the other monomer is preferably 10 mol% or less, 5 mol% or less, 1 mol% or less, and more preferably 0 mol% of the constituent unit of the copolymer.

  Specific examples of the monomer represented by the general formula (1) include dimethylaminomethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, diethylaminopropyl acrylate, dimethylaminoethylacrylamide, dimethylaminoethylmethacrylamide, dimethylaminopropyl. Examples include methacrylamide, diethylaminomethyl acrylamide, diethylaminomethyl methacrylamide and the like.

  Examples of the acid that forms a salt with the monomer include acetic acid, butyric acid, caproic acid, caprylic acid, glycolic acid, succinic acid, tartaric acid, phosphoric acid, butyl acid phosphate, octyl acid phosphate, boric acid and the like. .

  Further, in acrylic acid and methacrylic acid copolymerized with the above monomers, examples of the salt thereof include alkali metal, ammonium, alkylamine, polyoxyethylene alkylamine, alkanolamine, etc., and examples of the alkyl ester include acrylic acid. Examples thereof include butyl acid, lauryl acrylate, butyl methacrylate, lauryl methacrylate and the like, and alkyl amides thereof include, for example, acrylamide, dimethylacrylamide, methacrylamide and the like.

  The polymer compound (d) has a weight average molecular weight of 10,000 to 1,000,000, preferably 30,000 to 500,000. When the weight average molecular weight is 10,000 or more, the lubricating oil is emulsified and emulsified and dispersed. The stability is good, and when the weight average molecular weight is 1000000 or less, the polymer compound itself is excellent in stability and has an appropriate viscosity, and the handleability is also good. In addition, the weight average molecular weight of (d) component is measured by GPC method of the following conditions.

(conditions)
-Column: α-M (manufactured by Tosoh Corporation) x 2-Column temperature: 40 ° C
-Eluent: 0.1M Na sulfate 1% acetic acid aqueous solution-Detector: RI (refractometer)
Injection volume: 0.5 wt% eluent solution, 100 μl
Liquid flow rate: 1.0 ml / min
・ Molecular weight standard: Pullulan

  The polymer compound (d) can be used alone or in combination of two or more.

  The amount of the component (d) added is 0.1 to 3% by weight, more preferably 0.5 to 2% by weight, based on all the components of the lubricating oil, from the viewpoint of rolling oil particle size and long-term circulation stability. When the addition amount is within this range, the rolling oil particle size is large and the long-term circulation stability is also excellent.

  The lubricating oil for cold rolled oil of the steel sheet according to the present invention has the same component (a) as that disclosed in Patent Document 1, but the lubricating oil for cold rolled oil of the steel sheet according to the present invention is (b). The iodine value of the component is limited to a specific range, and the iodine value of the component (c) and the usage rate of the complex ester are controlled to be small. By limiting the iodine value of the component (c), the deposition scum can be reduced under a low temperature atmosphere, and by controlling the component (c) to be small, the proportion of the component (a) and the component (b) is relatively large. This improves the lubricity of the rolling oil. In the present invention, the use of a specific water-soluble polymer compound as component (d) further improves the lubricity and improves the stability of the lubrication. Therefore, according to the cold rolling oil for steel plates using the lubricating oil, slippage and advanced during high-speed rolling when the productivity rolls up and the rolling roll is worn without causing poor lubrication such as chattering and heat scratching. High-speed rolling can be performed at a speed of 1800 m / min or more without generating fine wrinkles on the plate surface due to rate fluctuations, and productivity is further improved.

  Further, in the present invention, as a result of finding that the cleaning property tends to be worse as the use ratio of the component (c) increases, the cleaning property is controlled by controlling the component (c) to be small as described above. Is also satisfied.

  On the other hand, the addition of the component (c) is effective in reducing the deposition scum, but as described above, the amount of the component (c) is controlled to be small from the viewpoint of lubricity and washability. Therefore, in the present invention, the component (c) is used as the component (b) and the component (c) in a predetermined range in order to satisfy the lubricity and the washability while reducing the deposition scum including the low temperature atmosphere using the component (c). Low iodine value is used. As described above, in the present invention, the ability to reduce accumulated scum including a low-temperature atmosphere can be satisfied, and high-speed rolling at a speed of 1800 m / min or more while avoiding problems such as a risk of fire, deterioration of aesthetics and deterioration of workability. it can.

  In the present invention, as described above, the amount of component (c) used is reduced as compared with Patent Document 1, and components having a low iodine value within a predetermined range are used as component (b) and component (c). Thus, the present invention provides a lubricating oil for steel sheet cold rolling oil, which can satisfy lubricity, washability, and deposited scum reduction including low temperature atmosphere even under high speed rolling.

  Moreover, the steel sheet cold rolling oil using the lubricating oil for cold rolling oil of the present invention contains the component (d), and even when the steel sheet is cold-rolled at a high speed, an appropriate grain size is obtained. The uniform emulsification dispersibility and particle size distribution can be kept stable for a long period of time. Therefore, long-term circulation stability is good, and even when it is used after being circulated in a cold rolling mill, the initial good rolling lubricity can be maintained for a long time, and it is produced even when various types of steel sheets are cold-rolled at high speed. Can be improved.

  In addition, when the processing part becomes high temperature during high speed rolling, the conventional emulsification type rolling oil using a high viscosity base oil causes non-uniform adhesion of oil and causes slip and chattering. Since the lubricating oil for hot rolling oil contains the component (d), the base oil is uniformly wetted in the processed part by making the cold rolling oil steel sheet into a water-dispersed type. There is no occurrence of slip and the like, and the slip resistance is excellent. Furthermore, the use of a base oil with a high base oil viscosity and high seizure resistance suppresses temperature rise due to frictional heat at the roll-steel interface, so seizure resistance does not occur even during high-speed rolling. Excellent in properties. In addition, it has excellent drainage treatment. The present invention also has these characteristics and has the advantage that a steel sheet can be produced at a lower cost and with higher efficiency.

  In addition to the components (a) to (d), the lubricating oil for steel sheet cold rolling oil of the present invention is selected from the group consisting of (e) a phosphorus extreme pressure agent and a sulfur extreme pressure agent. More seeds can be added. As a component (e), a phosphorus extreme pressure agent and / or a sulfur extreme pressure agent are blended and used at a specific quantitative ratio, thereby enabling rolling at a higher speed.

  Examples of the phosphorus extreme pressure agent of the component (e) include trioctyl phosphate, tricresyl phosphate, trioleyl phosphate, dioctyl acid phosphate, dilauryl acid phosphate, tributyl phosphite, trioleyl phosphate, ditridecyl acid phosphate. Phyto, dioleyl acid phosphite, aromatic amine salt of mono-2-ethylhexyl acid phosphate, and the like.

  Examples of the sulfur-based extreme pressure agent of component (e) include sulfurized lard, sulfurized fats and oils such as sulfurized beef tallow and sulfurized vegetable oil esters, sulfurized olefins and sulfurized mineral oils, active and inactive types, dibenzyl disulfide, and ditial, respectively. Examples include butyl disulfide and zinc-dialkyldithiophosphate.

  The phosphorus-based extreme pressure agent and sulfur-based extreme pressure agent as the component (e) contribute to seizure resistance, and the high lubricity of the steel sheet cold rolling oil using the lubricating oil for steel sheet cold rolling oil of the present invention. Has the effect of further improving. These phosphorus-based extreme pressure agents and sulfur-based extreme pressure agents of component (e) may be used alone or in combination of two.

  The added amount of the component (e) is used in the range of 0.5 to 5% by weight of the total components of the lubricating oil. Lubricability improves as the amount added increases. However, when the amount exceeds 5% by weight, the oil price becomes expensive and the improvement in seizure resistance against the increase is reduced, which is not practical. A range of 1 to 3% by weight is more practical and preferable in view of oil price and lubricity improvement effect.

  The cold-rolled oil for steel sheets of the present invention can be obtained by dispersing the lubricating oil for cold-rolled steel sheets of the present invention in water by a known method. Although the dilution ratio in this case is not particularly limited, it is usually preferable that the concentration of the lubricant is 1 to 20% by weight. By setting the concentration to 1% by weight or more, the effect as a rolling oil is suitably obtained. In addition, even if it uses exceeding 20 weight%, the improvement of the effect corresponding to an increase cannot be expected.

  In addition to the above components, various known additives such as oiliness improvers, rust inhibitors, antioxidants, and emulsifiers are added to the cold-rolled oil composition for water-dispersed steel sheets of the present invention as necessary. You can also.

  As the oiliness improver, for example, fatty acids such as oleic acid, beef tallow fatty acid, polymer acid of tall oil fatty acid and the like can be used, and these can be added in the range of 10% by weight or less of the total components of the lubricating oil.

  As the rust preventive, for example, alkenyl succinic acid and derivatives thereof, fatty acids such as oleic acid, esters such as sorbitan monooleate, and other amines can be used, and these are in the range of 2% by weight or less of the total components of the lubricating oil. Can be added.

  Examples of the antioxidant include phenols such as 2,4-di-tert-butyl p-cresol and tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane. Series compounds, aromatic amines such as phenyl α-naphthylamine, phenothiazine and the like can be used, and these can be added in a range of 5% by weight or less of the total components of the lubricating oil.

  Further, as an emulsifier, for example, anionic surfactants such as oleic acid triethanolamine salt, petroleum sulfonate sodium salt, nonionic surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene sorbitan trioleate, etc. These can be used and can be added in the range of 2% by weight or less of the total components of the lubricating oil.

  The cold rolling oil for steel sheet of the present invention is used in a process of rolling a steel sheet with a cold rolling mill in a method for producing a cold rolled steel sheet. As rolling oil supply system in cold rolling of steel sheet, a large amount of rolling oil emulsion is supplied to the steel sheet and roll, and the rolling oil emulsion is used for a long time while circulating the used rolling oil emulsion and removing iron wear powder. There are two systems: a direct rolling oil supply system that supplies an oil supply system and a small amount of rolling oil emulsion to the rolled steel sheet, supplies a large amount of water to the roll, and treats the used rolling oil emulsion as wastewater without circulating it. is there. Although the cold rolling oil for steel plates of this invention can be employ | adopted in any system, it is suitable when employ | adopting a circulating rolling oil supply system. It is particularly suitable when a tandem cold rolling mill using a circulation method is used.

Examples 1-7, Comparative Examples 1-10
As shown in Table 1, each component of the steel plate cold rolling oil lubricant was mixed and then stirred and dissolved uniformly while heating at 60 to 90 ° C. Next, the lubricating oil and tap water are mixed so that the oil concentration becomes 3% by weight of rolling oil (emulsion), and then heated and stirred with a homomixer, so that the average particle size of the emulsion is 10 ±. A 1 μm rolling oil was prepared. The average particle size of the emulsion is determined by the method described later.

  About the obtained rolling oil, rolling property (lubricity), washability, scum depositability, and particle size stability were evaluated by the following test examples. The results are shown in Table 1.

Test Example 1 (Rolling test: Rollability and washability)
The various rolling oils prepared were subjected to a strip single pass rolling test under the following conditions using a two-stage rolling mill (200 mmφ × 200 mm width, SUJ-2, Hs = 90), and the rolling load at a reduction rate of 40% (MPa ) To evaluate the lubricity. If the rolling load is 95 to 105% of the value of conventional beef tallow cold rolling oil (Comparative Example 9), the lubricity is good. Further, if it is higher than 105%, the lubricity is insufficient, and if it is lower than 95%, the lubricity is excessive. Moreover, the washability (alkali degreasing property) was evaluated based on the water wetted area ratio (%) of the degreased rolled steel sheet under the following conditions. In addition, if the water wetted area ratio is 80% or more, the washability is good. In the performance evaluation, “good” is indicated by “◯”, and poor “×” is indicated.

(Rolling conditions)
Rolled material: Mild steel (SPCC-B, 30 mm width x 700 mm length x 2 mm thickness, Ra = 0.02 µm)
Roll roughness: Polished in the rolling direction with abrasive paper and adjusted to Ra = 0.3 to 0.4 μm (Rz = 2.8 to 3.2 μm).
Plate temperature: 100 ° C
Rolling speed: 400 m / partial reduction: 40%
Rolling oil concentration: 3% by weight
Liquid conditions: 60 ° C., 10 liters Stirrer: M-type homomixer (manufactured by Special Machine Industries Co.)
Rotation speed: 9000r / min Spray amount: 2 liter / min x 1 each for top and bottom, 100kPa

(Degreasing conditions)
Pre-heat treatment: 150 ° C. × 12 hours (in air) (This pre-heat treatment was performed assuming high-speed rolling with an actual machine)
Degreasing solution: caustic soda 2% + polyoxyethylene nonylphenyl ether (HLB = 12.4) 0.1% by weight + sodium gluconate 0.1% by weight Solution degreasing method: dipping → electrolysis → rinse dipping condition: 80 ° C., 1 Second electrolysis condition: 80 ° C., 5 A / dm ² , 1 second rinse condition: 60 ° C. hot water spray (one side 1 liter / minute × 1 second)

Test Example 2 (Scum Deposition Test: Scum Deposition Resistance and Particle Size Stability)
About various prepared rolling oils, using a spray test device (300 mm width x 400 mm depth x 400 mm height), iron powder was added and a scum deposition test was conducted under the following conditions, and the scum resistance was determined by the amount of accumulated scum (g / m ² ). Sedimentability was evaluated. If the amount of accumulated scum is less than 110% of the value of the conventional ester cold rolling oil (Comparative Example 10), the scum accumulation resistance is good. In addition, the particle size of the emulsion before and after the addition of iron powder was measured with a Coulter counter (Multisizer, manufactured by BECKMAN COULTER), and the particle size stability was evaluated from the absolute value (μm) of the average particle size (volume distribution) change. . When the absolute value of change is 3 μm or less, the particle size stability is good. In the performance evaluation, “good” is indicated by “◯”, and poor “×” is indicated.

(Scum accumulation test conditions)
Test piece: Mild steel (SPCC-D, 100 mm × 100 m × 0.5 mm thickness), rolling oil concentration applied to the center of the left and right wall surfaces: 4% by weight
Iron powder amount: 2000 mg / kg (0.02 μm commercial iron powder)
Liquid conditions: 60 ° C., 3 liters Stirring conditions: M-type homomixer 9000 r / min Spray amount: 2 liters / min, 200 kPa (one nozzle installed in the front center)
Atmospheric temperature: 0 ° C
Test time: 30 minutes

(Kinematic viscosity, pour point)
The kinematic viscosity was measured according to JIS K2283. The pour point was measured according to JIS K2269.

  In addition, the mineral oil, monoester, fats and oils, complex ester, polymer compound, extreme pressure agent, and other additives in the above table mean the following.

Mineral oil A ... Paraffinic mineral oil (10mm ² / s, 40 ° C)
Mineral oil B ... Paraffinic mineral oil (28mm ² / s, 40 ° C)
Monoester A ... 2-ethylhexyl stearate monoester B ... Isodecyl stearate

Oil A ... Palm oil (iodine value 40, pour point 23 ° C)
Oil B: Palm oil (iodine value 30, pour point 25 ° C)
Oil C: Palm kernel oil (iodine number 19, pour point 28 ° C.)
Oil D: Palm oil (Iodine value 65, Pour point 3 ° C)
Oil E ... Tallow (iodine value 49, pour point 25 ° C)

Compound ester A ... ester (acid) obtained from polymer acid of tall oil fatty acid (dimer acid: polymer acid of trimer acid or higher = 75: 25) / pentaerythritol / coconut oil fatty acid = 0.9 / 2/6 (molar ratio) (Valence 3, hydroxyl value 4, iodine value 40, average molecular weight 2500)
Complex ester B: obtained from polymer acid hydrogenated product of tall oil fatty acid (dimer acid: polymer acid of trimer acid or higher = 94: 6) / trimethylolpropane / coconut oil fatty acid = 0.9 / 2/4 (molar ratio) Ester (acid value 3, hydroxyl value 6, iodine value 10, average molecular weight 1900)
Complex ester C: ester obtained from polymer acid of tall oil fatty acid (dimer acid: polymer acid of trimer acid or higher = 75: 25) / pentaerythritol / oleic acid = 1/2/6 (molar ratio) (acid value 4, (Hydroxyl value 8, iodine value 95, average molecular weight 3000)

Polymer compound A: Copolymer of neutralized glycolic acid of dimethylaminoethyl methacrylate / sodium acrylate = 6/1 (molar ratio) (average molecular weight = 400,000)
Polymer compound B ... Copolymer of glyceric acid neutralized product of dimethylaminopropylmethacrylamide / sodium acrylate = 3/1 (molar ratio) (average molecular weight = 180,000)

Extreme pressure agent A ... Trioleyl phosphate Extreme pressure agent B ... Tricresyl phosphate extreme pressure agent C ... Sulfurized lard (active type, S% = 10.5%)

Other A ... Oiliness improver (palm oil fatty acid)
Other B ... antioxidant (2,4-di-tert-butyl p-cresol)
Other C ... Rust preventive (hexadecenyl succinic acid)
Other D ... emulsifier (polyoxyethylene lauryl ether, HLB = 12.1)

  As is apparent from Table 1, only the examples satisfy all of the lubricity, washability, scum depositability and particle size stability. It can be seen that the comparative example has a problem with at least one of the performances.

Claims (4)

(A) 3 to 20% by weight of at least one selected from the group consisting of mineral oils and monoesters obtained from aliphatic carboxylic acids having 12 to 22 carbon atoms and aliphatic alcohols having 1 to 12 carbon atoms,
(B) 55 to 85% by weight of fats and oils having an iodine value of 25 to 50 (I ₂ g / 100 g),
(C) The remaining carboxyl group or hydroxyl group of the partial ester obtained from one or more selected from the group consisting of dimer acids and polymer acids of higher aliphatic unsaturated acids having 16 to 20 carbon atoms and polyols has 12 carbon atoms. 5 to 20% by weight of a complex ester having a weight average molecular weight of 750 to 20000, which is esterified with a monohydric alcohol or monohydric fatty acid of ˜22 and having an iodine value of 50 (I ₂ g / 100 g) or less, and (d) ( d1) General formula (1):

(Wherein R ¹ represents a hydrogen atom or a methyl group, R ² and R ³ represent an alkyl group having 1 to ³ carbon atoms, A represents —O— or —NH—, and m represents an integer of 1 to 3). ), A homopolymer containing a structural unit derived from a monomer or a salt thereof, (d2) a copolymer containing a structural unit derived from two or more of the monomers, (d3) It is a polymer selected from one or more and a copolymer comprising (meth) acrylic acid, a salt thereof, an alkyl ester or a structural unit derived from one or more of the alkylamide, and the weight average molecular weight is 10,000 to 1,000,000. A lubricating oil for steel sheet cold rolling oil containing 0.1 to 3% by weight of one or more water-soluble polymer compounds in the range of   The lubricating oil for cold-rolled steel sheet according to claim 1, wherein the ratio (b) / (c) of the component (b) to the component (c) is 3/1 to 15/1 in terms of weight ratio.   The cold rolling oil for steel plates containing the lubricating oil for cold rolling oil of steel plates of Claim 1 or 2, and water. A method for producing a cold rolled steel sheet comprising a step of rolling a steel sheet with a cold rolling mill while supplying cold rolled oil for the steel sheet,
A method for producing a cold rolled steel sheet, wherein the cold rolled oil for steel sheet according to claim 3 is used as the cold rolled oil for steel sheet, and the cold rolled oil for steel sheet is circulated and used.