JP2000026878A - Water-soluble cold rolling oil for stainless steel sheet and rolling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-soluble cold rolling oil for stainless steel sheet which is excellent not only in lubricity and gloss but also in eliminating abrasion powder and a rolling method for stainless steel sheet using the same. SOLUTION: This water-soluble cold rolling oil for stainless steel sheet, which contains a base oil, a nonionic surfactant, and an anionic surfactant, is characterized in that the base oil contains at least one oil selected from among mineral oils, synthetic ester oils, and synthetic hydrocarbon oils and has a kinemaic viscosity at 40 deg.C of 15 mm2/s or lower; that the amt. of a nonionic surfactant having an HLB of 14 or higher accounts for 10 wt.% or lower of the total amt. of the nonionic surfactant; and that the cold rolling oil has a knematic viscosity at 40 deg.C of 20 mm2/s or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble cold rolling oil agent for stainless steel sheets and a cold rolling method using the same.

[0002]

2. Description of the Related Art Stainless steel sheets are often used in parts that are easily visible, such as construction materials and outer panels of machines, because they have good gloss and are resistant to rust. Therefore, a stainless steel plate having always high gloss is required. To obtain a high-gloss stainless steel sheet, use a rolling mill with a small roll diameter, and use a rolling oil based on mineral oil with a low viscosity and relatively high flash point without diluting it with water. Rolling and lubricating the surface, or rolling oil having a relatively low kinematic viscosity of the stock solution (oil before dilution with water) with a small particle size of 5 to 20% (average particle size of 5 to 20%).
μm or less) By supplying and rolling as an emulsion,
Was compatible. Conventional water-soluble cold-rolling oil for stainless steel sheets has the purpose of rapidly reducing the emulsion particle size,
Nonionic surfactants having an HLB of 14 or more and anionic surfactants have been used in combination in order to achieve both the purpose of maintaining a small particle size stably over a long period of time. However, HLB1
When a large amount of 4 or more nonionic surfactants is used, the nonionic surfactant of HLB 14 or more is preferentially adsorbed to the surface of the wear powder generated during rolling, and the surface of the wear powder becomes hydrophilic. However, the redispersibility in the emulsion is reduced, and the abrasion powder adhering to the rolling mill or the draining plate causes indentation flaws in the rolled material, thereby deteriorating the surface glossiness of the rolled material.

[0003]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a water-soluble cold-rolling oil agent for stainless steel sheets which is excellent in lubricity and gloss and excellent in removing abrasion powder. Another object of the present invention is to provide a water-soluble cold rolling oil for a stainless steel sheet that can be rolled at a high speed and can obtain a stainless steel sheet having good gloss. Still another object of the present invention is to provide a method for rolling a stainless steel sheet using the above water-soluble cold rolling oil.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a base oil,
A water-soluble cold-rolling oil agent for stainless steel sheets containing a nonionic surfactant and an anionic surfactant, comprising: B. the base oil contains at least one member selected from the group consisting of mineral oil, synthetic ester oil, and synthetic hydrocarbon oil, and has a kinematic viscosity at 40 ° C. of 15 mm ² / s or less; B. the amount of the nonionic surfactant having an HLB of 14 or more in the nonionic surfactant is 10% by weight or less of the total amount of the nonionic surfactant; The kinematic viscosity at 40 ° C. is not more than 20 mm ² / s.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The base oil used in the present invention is preferably one which can lower the viscosity of the entire oil agent, and contains at least one selected from the group consisting of mineral oil, synthetic ester oil, and synthetic hydrocarbon oil. . 40 ° C. of the base oil used in the present invention
Has a kinematic viscosity of 15 mm ² / s or less, preferably 10 mm ² / s
s or less, more preferably 7 mm ² / s or less, and most preferably 4 to 6 mm ² / s. Mineral oils having a kinematic viscosity at 40 ° C. of 15 mm ² / s or less include, for example, spindle oils and machine oils, and those having a high degree of purification with a difference between an initial distillation temperature and an end temperature of 30 ° C. or less are preferable. Kinematic viscosity at 40 ° C is 15mm ² / s
As the following synthetic esters, the total carbon number is 15 to 30,
Preferably, 15 to 25 synthetic esters are used. More specifically, the number of carbon atoms is 22 or less (for example, 10 to 14).
(Monoester, diester, triester, etc.) of an aliphatic carboxylic acid or aromatic carboxylic acid or carbonic acid of the above with an aliphatic alcohol having 4 to 12, preferably 10 or less carbon atoms. For example, methyl oleate, ethyl oleate, butyl oleate, butyl laurate, 2-ethylhexyl laurate, butyl stearate, 2-ethylhexyl stearate, butyl palmitate, 2-ethylhexyl palmitate, dioctyl succinate, dioctyl carbonate , Di-2-ethylhexyl sebacate, di-2-ethylhexyl azelate, di-2-ethylhexyl phthalate, pentaerythritoldiolate, trimethylolpropane triolate and the like. Examples of the synthetic hydrocarbon oil having a kinematic viscosity at 40 ° C. of 15 mm ² / s or less include low-molecular-weight poly-α-olefin (PAO), low-molecular-weight polybutene, and alkylbenzene. The kinematic viscosity at 40 ° C. of the oil agent of the present invention is 20 mm ² / s or less, and preferably 10 mm ² / s or less. If the kinematic viscosity of the oil exceeds 20 mm ² / s, good surface gloss cannot be obtained.

The surfactant used in the present invention contains both a nonionic surfactant and an anionic surfactant. The amount of the nonionic surfactant having an HLB of 14 or more in the nonionic surfactant is as follows: It is 10% by weight or less of the total amount of the nonionic surfactant.

[0007] Nonionic surfactants include HLB1
The amount of the ether-type surfactant having an ether surfactant of 4 or more is 10% by weight or less of the total amount of the ether-type surfactant and / or the amount of the ester-type surfactant having an HLB of 14 or more is the total amount of the ester-type surfactant. An ester type surfactant having a content of 10% by weight or less is preferable, and HLB is more preferable.
An ether surfactant having an amount of 14 or more ether surfactants of 10% by weight or less of the total ether surfactant amount and an ester surfactant having an HLB of 14 or more being 10 weight% of the total ester surfactant amount. % Or less of an ester type surfactant. The reason that the combined use of the ether type surfactant and the ester type surfactant is more preferable because the emulsifying power for the base oil is stronger than the ester type surfactant because the ether type surfactant can reduce the emulsion particle size by adding a small amount. On the other hand, the ester surfactant has an effect of making it less susceptible to the effects of other oils such as tramp oil since it is likely to be present on the oil droplet surface.

The reason why the total amount of HLB 14 or more based on the total amount of nonionic surfactants is set to 10% by weight or less for both the ether type surfactant and / or the ester type surfactant is that the nonionic surfactant having an HLB of 14 or more is used. When a large amount of the agent is used, a nonionic surfactant having an HLB of 14 or more migrates to the aqueous layer over time, resulting in poor emulsion stability (increase in particle size.
HLB1 on the surface of wear powder generated by rolling.
Four or more nonionic surfactants are strongly adsorbed, changing the surface of the wear powder to hydrophilicity, reducing the dispersibility of the wear powder in the emulsion, and causing the dirt on the rolling mill and indentation flaws in the rolled material. Is larger.

Examples of the ether type surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene / polyoxypropylene alkyl ether and the like, and polyoxyethylene alkyl phenol ether is most preferable. This is because polyoxyethylene alkylphenol ether has the best emulsifiability with respect to the base oil.

Examples of the ester type surfactant include a sorbitan type, a fatty acid ester type and a polyglycerin fatty acid ester type, and the sorbitan type is most preferable.
This is because the sorbitan surfactant is least affected by mixing with other oils. Examples of the sorbitan-type surfactant include sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and more specifically, sorbitan monolaurate, sorbitan monostearate, sorbitan triolate, sorbitan sesquiolate, and sorbitan. Distearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan triolate, polyoxyethylene sorbitan tristearate, etc. Is mentioned.

Examples of the anionic surfactant include a fatty acid salt, an alkyl sulfonate, an aromatic sulfonate, a petroleum sulfonate, a dialkyl sulfosuccinate, and an alkyl sulfate, and are easily dissolved in a base oil. Aromatic sulfonates, petroleum sulfonates, and dialkyl sulfosuccinates are particularly preferred. The total amount of the nonionic surfactant and the anionic surfactant used is preferably 3 to 30% by weight, more preferably 5 to 30% by weight, and most preferably the rolling oil (rolling oil before dilution with water). 10 to 25% by weight. The weight ratio of the nonionic surfactant to the anionic surfactant is preferably from 95: 5 to 50:50, and more preferably from 95: 5 to 70:30.

The reason why the effect of the present invention is exhibited by using a nonionic surfactant and an anionic surfactant in combination is considered as follows. Since the anionic surfactant is excellent in wet permeability, it suppresses re-aggregation of wear powder generated by rolling, and prevents indentation flaws in a rolled material due to falling of wear powder stains around the rolling mill. On the other hand, the nonionic surfactant improves the dispersibility of the abrasion powder in the emulsion by adsorbing on the abrasion powder surface and changing the abrasion powder surface to an appropriate lipophilic property, whereby the abrasion powder is quickly removed. It contributes to reducing the amount of wear powder on the rolled material surface (improving the cleanliness of the rolled material). Furthermore, since nonionic surfactants have a large temperature dependence on the emulsifying action, emulsification stability is reduced under high coolant temperature conditions such as high-speed rolling, and the gloss of the rolled material is reduced due to an increase in the particle size, and floating oil is increased. Has the drawback of causing deterioration of the oil consumption rate due to the increase in oil content, but the combined use of an anionic surfactant makes it possible to maintain the emulsion stability even under high coolant temperature conditions, thereby ensuring long-term emulsion stability. It will be.

The rolling oil of the present invention may contain, if necessary, a general sulfur-based or phosphorus-based extreme pressure agent, a phenol-based or amine-based antioxidant, an oily agent such as an aliphatic carboxylic acid or an aliphatic alcohol, An amine salt of an aliphatic carboxylic acid or a rust preventive such as succinic acid may be added. The amount of these additives used in the rolling oil (rolling oil before dilution with water) is 0.1 to 0.1%.
It is about 10% by weight.

The rolling oil of the present invention can be easily produced by adding other components to a base oil, heating and dissolving at about 50 to 60 ° C., and stirring. The rolling oil agent of the present invention has a
It is diluted with water so as to be 0% by weight, for example, about 10% by weight to obtain a rolling oil emulsion, and is supplied to a rolling roll and / or a stainless steel sheet material surface by, for example, a nozzle. The supply amount is suitably about 1000 to 6000 m ³ / min. The rolling oil agent of the present invention has an average particle size of the emulsion particles of 5% when diluted with water so as to be 10% by weight.
It is preferably not more than μm, particularly preferably 0.5 to 3 μm.
More preferably, it is 1 to 3 μm.

As described above, by having a relatively high concentration and reducing the average particle size of the emulsion particles, good surface properties (glossiness) and lubricity can be obtained even when rolling is performed at a high speed (for example, 800 m / min or more). Can be obtained. If the average particle size of the emulsion particles is large, the amount of the rolling oil applied becomes large and uneven adhesion is apt to occur, and wear powder is liable to be entrained in the emulsion, thereby lowering the glossiness of the stainless steel sheet. On the other hand, if the average particle size of the emulsion particles is less than 0.5 μm, the lubricity decreases. The rolling oil agent of the present invention is also applicable to ferritic stainless steel sheets and austenitic stainless steel sheets.

[0016]

The present invention will be described in more detail with reference to the following examples.

Examples 1 to 23 and Comparative Examples 1 to 6 Each component (weight ratio) was added to the base oils shown in Tables 1 to 4, dissolved by heating, and mixed by stirring to prepare a rolling oil. The rolling oil was diluted with water to 10% by weight, and various characteristics were examined using the diluted liquid. A commercially available cold-rolling oil agent for a water-insoluble stainless steel sheet was used as Comparative Example 6. The results are shown in Tables 5 to 8.

The kinematic viscosity is the kinematic viscosity of a base oil or an oil agent (before dilution with water) measured at 40 ° C. with a JIS K-2283 Ubbelohde viscometer. A. Measurement of Average Particle Size The average particle size was determined by diluting the rolling oil agent with ion-exchanged water to 10% by weight (using a 1 L glass beaker).
Tokushu Kika Kogyo Co., Ltd. K. Homomixer MARKII
After stirring at 8000 rpm for 3 minutes according to 2.5, 30 minutes using Coulter Multisizer (manufactured by Coulter).
It was measured at an orifice diameter of μm.

B. Emulsion stability and abrasion powder dispersibility test
SUS304 ultrafine powder (80n made by Taiheiyo Metal Co., Ltd.)
m) was added, and T.P. K. After stirring for 3 minutes at 8000 rpm with a homomixer MARKII2.5, the particle size change (A) and the state of the emulsion were determined. [Emulsification stability] A = particle size (μm) after adding SUS304 ultrafine powder−SUS
Particle size (μm) after addition of 304 ultrafine powder Judgment: Δ = 1 μm or less Δ = 1 μm or more and 2 μm or less × = 2 μm or more

[Wear powder dispersibility] Emulsion state during stirring Judgment: ○: SUS304 ultrafine powder is well dispersed in emulsion (beaker wall / no ultrafine powder adheres to stirrer) △ = SUS304 ultrafine powder is dispersed to some extent (beaker wall / 1. Ultra-fine powder adheres little to the stirrer. × = SUS304 ultra-fine powder hardly disperses (large adherence of ultra-fine powder to beaker wall / stirrer). Emulsion state after stopping stirring Judgment: ○ = SUS304 ultrafine powder sedimented and separated quickly × = No SUS304 ultrafine powder settled and separated (Large adhesion of ultrafine powder to beaker wall and stirrer) * Sedimentation and separation of fine powder after stopped stirring Good properties lead to improved emulsification stability and simplification of the filtration device in actual equipment.

C. Lubricity test Glossiness and rollability are measured for SU ferritic stainless steel sheet.
Using the S430 pickling coil, roll under the following conditions,
Evaluation was made based on glossiness, rolling load, and seizure limit rolling reduction. Rolling conditions Test material: SUS430 hot rolled, pickled material, thickness 3.2 mm, plate width 50 mm, coil weight: 280 kg Rolling roll: material and hardness SUJ-2, Hs = 91-93 Dimensions: φ100 mm × 200 mmw (2Hi : BUR 250 mm) Surface roughness: Ra: 0.13 μm Rolling conditions: Finished sheet thickness after 9 pass rolling 0.38 mm Rolling reduction: 22% for each pass Rolling speed: 1-2 passes 400 m / min 3-5 passes 600 m / min 6 -7 passes 800 m / min 8-9 passes 1000 m / min The water-insoluble rolling oil of Comparative Example 6 is 3-9 passes 600 m
/ Min.

1. Gloss Measured at 60 ° gloss Judgment: ○ = 400 or more □ = 350 or more and less than 400 Δ = 300 or more and less than 350 × = less than 300 Rolling load Evaluated by the sum of all loads of 9 passes Judgment: ○ = less than 160 t □ = 160 t or more and less than 180 t △ = 180 t or more and less than 200 t × = 200 t or more Critical rolling reduction rate at the 5th pass The rolling reduction at the 5th pass was set to 25%, 27.5% and 30% to observe the burning state, and the rolling reduction at which no burning occurred was defined as the critical burning reduction rate. The glossiness, rolling load, and seizure limit rolling reduction are required to be equal to or higher than those of a commercially available water-insoluble rolling oil. When the rolling was carried out under the above rolling conditions, the stain on the draining plate and the stain on the surface of the rolled material were evaluated by the following methods. 4. 4. Stained state of the drain board (visual) Judgment: ○ = no abrasion powder adhered to the drain board △ = medium degree of abrasion powder adhered to the drain board × = large abrasion powder adhered to the drain board Rolled material surface contamination Wash the rolled material surface thoroughly with absorbent cotton impregnated with hexane,
The absorbent cotton used for washing was ashed, and the ash content was determined. Judgment: ○ = Ash value is 30 (mg / m ² ) or less △ = Ash value is 50 (mg / m ² ) or less × = Ash value is 50 (mg / m ² ) or more

D. Roll dirt test Under the following conditions, a two-cylinder rolling slip test was performed to measure the amount of abrasion powder adhering to the rolling rolls. Slip test condition Rolling roll: SUJ-2, Hs = 91-93 Dimension: Φ150 mm × 20 mm width Surface roughness: 2.5 μmRa Number of rotations: 200 rpm Material roll: SUS430 Dimension: Φ150 mm × 20 mm width Surface roughness: 2.5 μmRa rotation Number: 100 rpm Pressing load: 300 kgf Average wear amount of material roll: 7.4 (g / h) Judgment: ○ = Adhesion amount of rolling roll is 0.5 (g / h) or less △ = Adhesion amount of rolling roll is 2 Less than 0.0 (g / h) × = the adhesion amount of the rolling roll is 2.0 (g / h) or more

[0023]

Table 1 Example 1 2 3 4 5 6 7 8 Base oil Mineral oil 1 52 52 53 53-----2----53---3-----53--Synthetic ester oil 130- − − 30 30 − − 2 − 30 − − − − − − − 3 − − 30 − − − − − 4 − − − 30 − − 30 50 Synthetic hydrocarbon oil 1 − − − − − − 53 33 Nonionic surfactant Agent 3 2 2 2 2 2 2 2 2 4 3 3 3 3 3 3 3 3 5 3 3 3 3 3 3 3 3 3 9 ............... ... ... ... ... ... 2 7 7 7 7 7 7 7 7 7 Anion surfactant Agent 14 1 1 1 1 2 − 1 1 15 1 1 1 1 − 2 1 1 Extreme pressure agent 11 1 − − − − − − − − 2 − 1 − − − − − − −

[0024]

[Table 2] Example 9 10 11 12 13 14 15 16 Base oil Mineral oil 1 53 77 52 52 52 45 53 51 Synthetic ester oil 1 30-30 30 30 30 30 30 Nonionic surfactant 3-2-22 2 3 −2 4 8 3 3 3 3 5 − 3 5 − 3 3 3 3 5 − 3 6 − − − − − − − − 19 2 2 − − − − − − − − 10 5 7 7 7 7 10 15 7 Anion interface Activator 14 2 − 1 1 1 1 2 1 15 − 2 1 1 1 1 − 1 Extreme pressure agent 1 − − 1 1 1 − − 1 BHT − 1 − − − − − − Oleyl alcohol − 5 − − − − − −

[0025]

Table 3 Example 17 18 19 20 21 22 23 Base oil Mineral oil 1 52.5 51.5 52 52 52 52 52 Synthetic ester oil 1 30 30 30 30 30 30 30 Nonionic surfactant 1--16----2 ^* 0.5 − − − − − − − 3 2 2 − − − − − 2 4 3 3 − − − − 3 5 3 3 − 16 − − 37 − − − − − 16 − − 8 ^* − 1 − − − − − 10 7 7 − − − 16 8 Anionic surfactant 12 − 0.5 − − − − − 13 − − − − − − 1 14 2 2 2 2 2 2 1

[0026]

Table 4 Comparative Example 1 2 3 4 5 6 Base oil Mineral oil 1 52 52 52 44 52- Synthetic ester oil 1 30 30 30 30 30- Nonionic surfactant 2 ^* -----3-2 2 2 2 2 2 − 4 3 3 3 3 3 − 5 − 3 − − − − − 6 ^* 3 − 36 − − 10 7 − − 13 7 − 11 ^* − 7 7 − − − Anionic surfactant 14 1 1 1 1 1 − 15 1 1 1 1 1 − Extreme pressure agent 1 1 1 1 − 1 −

Mineral oil 1: Kinematic viscosity at 40 ° C. 4.8 mm ² / s Mineral oil 2: Kinematic viscosity at 40 ° C. 6.8 mm ² / s Mineral oil 3: Kinematic viscosity at 40 ° C. 8.7 mm ² / s Synthetic ester oil 1: Methyl oleate (Kinematic viscosity at 40 ℃
4.3 mm ² / s) Synthetic ester oil 2: butyl laurate (kinematic viscosity at 40 ° C)
3.7 mm ² / s) Synthetic ester oil 3: butyl stearate (kinematic viscosity at 40 ° C)
6.7 mm ² / s) Synthetic ester oil 4: 2-ethylhexyl laurate (40 ° C)
Kinematic viscosity of 9.3 mm ² / s) Synthetic hydrocarbon oil 1: poly-α-olefin (kinematic viscosity at 40 ° C. 5.9 mm ² / s) Synthetic hydrocarbon oil 2: poly-α-olefin (kinematic viscosity at 40 ° C. 12 mm ² / s) Nonionic surfactant (* is attached to those with an HLB of 14 or more) Surfactant 1: polyoxyethylene glycol monooleate (HLB = 11.6) Surfactant 2 ^* : polyoxy Ethylene glycol distearate (HLB = 18.3) Surfactant 3: Sorbitan monooleate (HLB = 4.7) Surfactant 4: Polyoxyethylene sorbitan monooleate (HLB = 10.0) Surfactant 5: Polyoxyethylene sorbitan monolau Rate (HLB = 13.3) Surfactant 6 ^* : polyoxyethylene sorbitan monooleate (HLB = 15.0) Surfactant 7: polyoxyethylene lauryl ether (H
LB = 9.6) Surfactant 8 ^* : polyoxyethylene lauryl ether
(HLB = 15.3) Surfactant 9: polyoxyethylene alkylphenol ether (HLB = 10.5) Surfactant 10: polyoxyethylene alkylphenol ether (HLB = 11.7) Surfactant 11 ^* : polyoxyethylene alkylphenol ether (HLB = 14.5) ) Anionic surfactant Surfactant 12: Potassium semi-hardened tallow fatty acid Surfactant 13: Sodium alkylnaphthalene sulfonate Surfactant 14: Sodium dialkyl sulfosuccinate Surfactant 15: Sodium petroleum sulfonate Extreme pressure agent 1: Dialkyl Polysulfide (sulfur content 22
%) Extreme pressure agent 2: dilauryl hydrogen phosphite (phosphorus content: 6.7%) BHT: dibutylhydroxytoluene

[0028]

Example 5 Viscosity of base oil (mm ² / s) 4.5 4.0 6.8 7.3 5.7 6.7 7.8 7.8 10.5 Viscosity of oil (mm ² / s) 5.6 5.6 7.8 8.3 6.6 7.6 8.6 11.0 Average Particle size (μm) 2.3 2.5 2.8 3.0 2.4 2.8 3.1 3.6 Emulsion stability ○ ○ ○ ○ ○ ○ △ ○ Emulsion state (while stirring) ○ ○ ○ ○ ○ ○ △ ○ Emulsion state (stop stirring) ○ ○ ○ ○ ○ ○ △ ○ Emulsion concentration during rolling test (%) 10 10 10 10 10 10 10 10 10 Glossiness of rolled material ○ ○ ○ □ ○ ○ □ △ Rolling load (9 pulse meter) △ △ □ ○ □ □ ○ ○ Under baking limit pressure Rate (%) 27.5 27.5 27.5 30 27.5 27.5 30 30 Drain plate contamination ○ ○ ○ ○ ○ ○ △ ○ Surface contamination of rolled material ○ ○ ○ ○ ○ ○ △ ○ Roll roll contamination during cylindrical sliding test ○ ○ ○ ○ ○ ○ △ ○

[0029]

Example 9 Viscosity of base oil (mm ² / s) 4.5 4.8 4.5 4.5 4.5 4.5 4.5 4.5 Viscosity of oil (mm ² / s) 5.9 6.1 5.6 5.6 5.6 6.2 7.0 5.7 Average Particle size (μm) 3.2 2.6 2.3 2.3 2.3 2.1 3.3 2.2 Emulsion stability △ △ ○ ○ ○ ○ △ ○ Emulsion state (while stirring) △ △ ○ ○ ○ ○ △ △ Emulsion state (stop stirring) △ △ ○ ○ ○ ○ △ △ Emulsion concentration during rolling test (%) 10 10 5 15 20 10 10 10 Glossiness of rolled material ○ ○ ○ ○ □ ○ ○ □ Rolling load (9 pulse total) □ □ △ ○ ○ □ □ ○ Rate (%) 25 27.5 27.5 30 30 25 25 27.5 Drained plate stain △ △ ○ ○ ○ ○ △ △ Rolled material surface stain △ △ △ ○ ○ ○ △ △ Roll roll stain during cylindrical sliding test △ △ △ ○ ○ ○ △ △

[0030]

Example 17 Viscosity of base oil (mm ² / s) 4.4 4.9 4.9 4.9 4.9 4.9 4.5 Viscosity of oil (mm ² / s) 5.6 6.1 6.5 6.8 6.8 6.7 6.7 5.7 Average particle size ( Table 7) μm) 2.3 2.8 3.8 3.5 3.6 3.7 2.4 Emulsion stability ○ △ △ △ △ △ ○ Emulsion state (while stirring) △ △ △ △ △ △ ○ Emulsion state (stop stirring) △ △ △ △ △ △ ○ Emulsion during rolling test Concentration (%) 10 10 10 10 10 10 10 Glossiness of rolled material ○ ○ ○ ○ ○ ○ ○ Rolling load (9-base meter) ○ ○ ○ ○ ○ ○ ○ Critical reduction rate of baking (%) 27.5 27.5 27.5 27.5 27.5 27.5 27.5 Stained state of draining board △ ○ △ △ △ △ ○ Surface stain of rolled material △ △ △ △ △ △ ○ Roll roll stain during cylindrical sliding test △ △ △ △ △ △ ○

[0031]

Table 8 Comparative Example 1 Viscosity of base oil (mm ² / s) 4.5 4.5 4.5 4.4 4.6- Viscosity of oil (mm ² / s) 5.7 5.8 5.8 7.3 5.8 7.6 Average particle size (μm) 2.1 2.0 2.0 1.8 1.9- Emulsion stability △ △ × △ ×-Emulsion state (while stirring) △ × × × × -Emulsion state (stop stirring) × × × × × -Emulsion concentration during rolling test (%) 10 10 10 10 10 100 Glossiness of rolled material □ △ × △ × ○ Rolling load (9 pulse meter) △ △ △ × × □ Critical reduction rate of baking (%) 27.5 27.5 25 25 25 25 Stained drain board △ × × × × ○ Surface contamination of rolled material △ × × × × ○ Roll roll contamination during cylindrical slip test △ × × × × ○

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // C10N 20:00 20:02 40:24 50:02 (72) Inventor Hiroshi Ueya 1 Tsujido Jindai 1, Fujisawa-shi, Kanagawa -4-1 Kyodo Yushi Co., Ltd. Tsujido Plant (72) Inventor Hideo Yamamoto 4-5-33 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Inventor Satoshi Matsushita Kitahama, Chuo-ku, Osaka City, Osaka Prefecture 4-5-33 Sumitomo Metal Industries, Ltd. F-term (reference) 4H104 AA01Z BB34C BB35C BB44C BB47C BG06C DA02A EA02A EA08A EA30A EB02 EB04 LA10 PA28 PA35 QA01 QA02

Claims (5)

[Claims] 1. A water-soluble cold-rolling oil agent for stainless steel sheets containing a base oil, a nonionic surfactant and an anionic surfactant, comprising: B. the base oil contains at least one member selected from the group consisting of mineral oil, synthetic ester oil, and synthetic hydrocarbon oil, and has a kinematic viscosity at 40 ° C. of 15 mm ² / s or less; B. the amount of the nonionic surfactant having an HLB of 14 or more in the nonionic surfactant is 10% by weight or less of the total amount of the nonionic surfactant; A water-soluble cold-rolling oil agent for stainless steel sheets, which has a kinematic viscosity at 40 ° C of 20 mm ² / s or less. 2. The oil agent according to claim 1, wherein the nonionic surfactant contains an ether type surfactant and an ester type surfactant. 3. The oil agent according to claim 1, wherein the ester surfactant is a sorbitan surfactant. 4. The anionic surfactant comprises at least one selected from the group consisting of petroleum sulfonates, aromatic sulfonates, and dialkyl sulfosuccinates.
The oil agent according to claim 1. 5. A method for rolling stainless steel, comprising using the oil agent according to claim 1 as a rolling oil emulsion having an average particle size of 0.5 to 3 μm.