JP5449837B2 - Cold rolling oil for steel plate and cold rolling method - Google Patents

Description

  The present invention is an emulsion-type cold rolling oil used when cold-rolling steel sheets containing Si, particularly electrical steel sheets, and has excellent emulsifiability and lubricity at high temperatures and excellent oil stain resistance. The present invention relates to a cold rolling oil and a cold rolling method.

  In cold rolling of steel sheets, emulsion type rolling oil is generally used for the purpose of lubrication and cooling. Normally, it is used repeatedly in a circulating manner, so cold rolled oil has not only lubricity but also emulsification stability, lubrication stability, thermal stability, as well as corrosion resistance, milk cleanliness, and oil stain resistance of steel sheets. Various characteristics are required to be highly balanced.

  For example, if emulsification stability and lubrication stability are impaired, there is a risk that a portion of insufficient lubrication and excessive lubrication will occur during cold rolling, resulting in a poorly shaped steel plate after cold rolling, When oil stain is generated, a color difference on the surface of the steel sheet causes a temperature difference from the surroundings during subsequent annealing, resulting in a defective shape or a pattern remaining on the surface of the steel sheet.

  Furthermore, if the thermal stability of the rolling oil is inferior, when it is circulated and used repeatedly, it deteriorates by oxidation and the sludge adheres to the steel sheet. To do.

  In particular, a steel sheet containing Si, such as an electromagnetic steel sheet, is called a so-called difficult-to-roll material because the hardness of the steel sheet increases, the tendency of the rolling load to increase is remarkable, and the brittleness is inferior.

  In order to cold-roll such a difficult-to-roll material, it is common to improve the rollability by using a roll having a small diameter rather than rolling a general steel material, and a multi-stage roll such as a Sendzimir mill is difficult. It is often used for cold rolling of rolled material.

  In recent years, the required quality on the surface of rolled material has become more stringent, and there is a strong demand for rolling oil that does not generate shape defects and oil stains that lower the product value. Furthermore, in order to improve quality stability and yield, there is a strong demand for rolling oils that have superior lubricity and emulsification stability.

  In other words, in cold rolling using a small-diameter rolling roll such as a magnetic steel sheet, there is a case where gear oil used for a roll bearing or roll driving gear is mixed into the rolling oil.

  That is, until now, the required quality and yield of the rolled material have not been so high, so that gear oil mixed in a small amount is not considered so much, and only the performance of the rolling oil has been improved.

  However, because the required level of productivity such as the shape and oil stain for the rolled material, the lubrication speed and the yield is increased, by using the rolling oil in consideration of the mixing of gear oil, in the cold rolling of electrical steel sheet It is necessary to improve lubricity, emulsion stability, thermal stability, and oil stain resistance.

  Furthermore, if the mixed gear oil cannot be separated, the ratio of the gear oil in the rolling oil is increased, which adversely affects the lubricity and emulsification properties.

  For example, Patent Document 1 discloses a cold-rolled oil containing a base oil, a specific cationic emulsifier, a specific nonionic polymer compound, and a higher aliphatic alcohol. In addition, an abnormal phenomenon such as chattering is prevented. However, in the case of an electromagnetic steel sheet, since there is no suppressing action against oil stain, local discoloration is a concern, and rolling with a small diameter roll is not assumed.

  Patent Document 2 discloses a technique regarding a water-soluble cold rolling oil for a stainless steel plate containing a nonionic surfactant having a specific kinematic viscosity, a nonionic surfactant having a specific HLB value, and an anionic surfactant. In this case as well, although there is a description regarding the roll diameter of the rolling mill, since it is for a stainless steel plate, there is no suppression effect on the oil stain specific to the electromagnetic steel plate, and there is no such description.

  Further, Patent Document 3 discloses a rolling oil for aluminum or aluminum alloy comprising a base oil containing a specific amount of a compound having a mercaptoimidazole group, a polyoxyethylene polyoxypropylene polymer, a fatty acid, an alkanolamine, and an antioxidant. ing. In this case, the material is aluminum or an aluminum alloy and is sometimes called hot rolling, and the lubricity and oil stain resistance to the steel sheet are not considered.

  Patent Document 4 discloses a base oil having a specific kinematic viscosity, a pour point in a specific range and a viscosity index, an ethylene α-olefin copolymer having a specific molecular weight, zinc dialkyldithiophosphate, sulfurized fat and oil, calcium having a specific total base number. Techniques for gear oil compositions containing specific amounts of sulfonates are disclosed. However, it is naturally assumed that it is used alone, and there is no disclosure or description of the properties after mixing with emulsion type cold rolling oil.

JP-A-11-124592 JP 2000-26878 A JP 11-106777 A JP-A-11-323370

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide excellent lubricity, emulsification and emulsification stability when gear oil is mixed, and excellent resistance. An object of the present invention is to provide a cold rolling oil for steel plate and a cold rolling method having oil stain properties and gear oil separation properties.

(1) Mineral oil and 5 to 30 mass% with respect to the total mass, 3 to 10 mass% with respect to the synthetic ester synthesized from a fatty acid and a divalent or higher alcohol and having a hydroxyl value of 100 to 300 and the total mass An amine-based emulsifier, and an aliphatic or aromatic carboxylic acid (excluding succinic acid) or an aliphatic or aromatic carboxylic acid derivative that is 1.0 to 5.0 mass% with respect to the total mass, And at least one oil-soluble alkenyl succinic acid or alkenyl succinic acid derivative of 0.1 to 5.0 mass% as an essential component . The aliphatic or aromatic carboxylic acid derivative is aliphatic or aromatic. Carboxylic acid (excluding succinic acid) is alkylated or alkenylated to make it oil-soluble, and used when gear oil is mixed with anti-emulsifying properties of 25 minutes or less. Steel for cold rolling oil, characterized in that.
(2) A circulation system in which the emulsion obtained by diluting the cold-rolled oil according to (1) is adjusted so that the mixing amount of gear oil having a demulsibility of 25 minutes or less is 0.1 to 5.0 mass%. Cold rolling method used in

  As described above, the cold-rolled oil of the present invention has not only lubricity but also good emulsifiability and emulsification stability, and has particularly excellent oil stain resistance and gear oil separability. Therefore, excellent surface quality of the rolled material can be obtained by the cold rolling method to which the cold rolling oil of the present invention is applied.

  The cold rolling oil and the cold rolling method of the present invention are suitable for, for example, steel sheets containing Si, particularly electromagnetic steel sheets.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The steel plate used in the embodiment of the present invention is suitably one containing Si, and a steel plate generally referred to as an electromagnetic steel plate is used. For example, the amount of Si added is suitably 0.6 mass% or more and less than 7.0 mass%. Furthermore, 0.8 mass%-3.5 mass% are suitable, More preferably, it is the range of 2.0 mass%-3.25 mass%. As other additive elements, for example, Al and Mn are suitable. For example, Al is preferably 0.1 mass% or more and less than 3.0 mass%, and Mn is preferably 0.01 mass% or more and less than 1.0 mass%, for example. The other typical elements are, for example, suitably 0.01 mass% or less in total, and more preferably 0.002 mass% or less.

  As the cold rolling oil used in the embodiment of the present invention, mineral oil is used as a base oil. There are paraffinic and naphthenic mineral oils, and any of them can be used. Specifically, machine oil, spindle oil, derby oil and the like.

  The synthetic ester used in the embodiment of the present invention is, for example, an esterified product of a fatty acid and a dihydric or higher alcohol, and particularly has a hydroxyl value of 100 or higher when partially esterifying the hydroxyl group of the alcohol. Examples of fatty acids include saturated fatty acids such as tridecanoic acid, myristic acid, palmitic acid, stearic acid, crotonic acid, undecylenic acid, lauroleic acid, Linderic acid, tuzuic acid, fizeteric acid, myristoleic acid, palmitoleic acid, petrothelic acid , Oleic acid, elaidic acid, vaccenic acid, erucic acid, and linoleic acid having multiple unsaturated bonds, hiragoic acid, eleostearic acid, linolenic acid, monooctyic acid, stearidonic acid, arachidonic acid, eicosapentaenoic acid, etc. Saturated fatty acids can be used.

  Specifically, the dihydric or higher alcohol used in the synthetic ester according to the embodiment of the present invention is ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, hexylene glycol, glycerin, polyglycerin, trimethylolethane, It is a polyhydric alcohol such as trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, etc., and may be one or a mixture of two or more selected from these.

  The synthetic ester used in the embodiment of the present invention is composed of the above fatty acid and a polyhydric alcohol and has a hydroxyl value of 100 or more and 300 or less. The hydroxyl value as used herein is determined by a test method defined in JIS K 0070, and defines the amount of hydroxyl groups in the molecule. If the structure of the synthetic ester is known, the calculated value can be calculated. It can be used.

  The hydroxyl value indicates the abundance of free hydroxyl groups in the synthetic ester molecule, and the inventors of the present application are very suitable rolling oil by blending a synthetic ester having a hydroxyl value defined in the range of 100 to 300. It has been found that characteristics can be obtained. This is because the synthetic ester having a hydroxyl group of less than 100 is inferior in affinity to the steel sheet surface, and if it exceeds 300, the lipophilicity is low, and in any case, the rust prevention effect is inferior.

  Next, general aliphatic monoamine compounds, polyamine compounds and alcoholic amines can be used as the amine-based emulsifier used in the embodiment of the present invention. Specifically, monoamines include laurylamine, cetylamine, stearylamine, and monoamine compounds include N-aminopropyldecylamine, N-aminomyristylamine, N-aminopropylbehenylamine, and the like. Furthermore, examples of the polyamine include N-lauryl dipropylene triamine, N-stearyl dipropylene triamine, N-myristyl tripropylene tetramine, N-stearyl tripropylene tetramine, and the like. In the case of a linear aliphatic amine compound, those having 8 to 20 carbon atoms are particularly suitable. Furthermore, it is also possible to use a polyamine compound obtained by adding ethylene oxide or propylene oxide, or a mixture thereof. The ethylene oxide chain to be added preferably has 30 to 100 carbon atoms. The alcoholic amine has characteristics as both a primary amine and a primary alcohol, and specifically includes monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and the like.

  The aliphatic or aromatic carboxylic acid or the aliphatic or aromatic carboxylic acid derivative used in the embodiment of the present invention includes enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, and myristic acid. Saturated aliphatic carboxylic acids such as pentadecylic acid, palmitic acid, margaric acid and stearic acid are preferred, but oleic acid, linoleic acid and linolenic acid having a double bond for use as an addition reaction point in derivatization , Unsaturated aliphatic carboxylic acids such as arachidonic acid, hydroxyl groups such as sabinic acid, iprolic acid, yarapinolic acid, ricinoleic acid and licanoic acid as reaction points for partial esterification, and aliphatics such as malonic acid and succinic acid Fatty acids having a functional group other than carboxylic acid such as dicarboxylic acid may be used. Moreover, as aromatic carboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, melittic acid and the like can be used, and as derivatives thereof, alkylation, alkenylation, amine chloride, partial amidation, partial esterification, Examples thereof include those made anhydrous and oil-soluble. In the embodiment of the present invention, these may be used alone or in combination.

  The alkenyl succinic acid or derivative of alkenyl succinic acid used in the embodiment of the present invention is an organic material that stays on the oil phase side when cold rolling oil is used and exhibits an effect for preventing rusting and oil stain by adsorbing to a steel plate. A compound. Specific examples include alkenyl succinic acid, alkenyl succinic anhydride, and alkenyl succinic acid ester.

  The content of the amine emulsifier needs to be 3.0 to 10.0 mass%. If it is less than 3.0 mass%, the emulsion stability at high temperatures is insufficient, which is not preferable. On the other hand, if it exceeds 10.0 mass%, the effect is saturated, which is not economical, and the gear oil may be too emulsified to deteriorate the lubricity. The content of the amine emulsifier is preferably 4.0 to 6.0 mass%.

  Next, the synthetic ester content needs to be 5.0 to 30.0 mass%. If it is less than 5.0 mass%, the lubricity effect is insufficient, which is not preferable. If it exceeds 30.0 mass%, the oil stain resistance is deteriorated. The synthetic ester content is more preferably 8.0 to 20 mass%.

  Next, the content of the aliphatic or aromatic carboxylic acid or the aliphatic or aromatic carboxylic acid derivative needs to be 1.0 to 5.0 mass%. If it is less than 1.0 mass%, the emulsion stability is poor, and if it exceeds 5.0 mass%, the oil stain resistance is deteriorated. The content of the aliphatic or aromatic carboxylic acid or the aliphatic or aromatic carboxylic acid derivative is more preferably 1.5 to 3.0 mass%.

  Next, the content of the oil-soluble alkenyl succinic acid or alkenyl succinic acid derivative needs to be 0.1 to 5.0 mass%. If it is less than 0.1 mass%, there is no effect of addition, the oil stain resistance is lowered, and even if added over 5.0 mass%, the effect is saturated and it is not economical. The content of the oil-soluble alkenyl succinic acid or alkenyl succinic acid derivative is more preferably 0.5 to 3.0 mass%.

  Moreover, in embodiment of this invention, the gear oil used with the cold rolling oil for steel plates which concerns on embodiment of this invention needs to have a demulsibility for 25 minutes or less. This is because if the demulsibility exceeds 25 minutes, the gear oil present in the coolant cannot be separated, and the rollability may be deteriorated or the shape may be poor.

  The anti-emulsifying property is measured in accordance with JIS K 2520 by the time required to separate the emulsified emulsion by stirring at 1500 rpm for 5 minutes at 82 ° C. into an aqueous phase and an oil phase.

  In the cold rolling method according to the embodiment of the present invention, the cold rolling oil for steel sheet according to the embodiment of the present invention has a concentration of, for example, 0.5 to 15.0 mass% with respect to a solvent such as deionized water. The emulsion diluted above is adjusted, and the above-mentioned gear oil whose amount is mixed so as to be 0.1 to 5.0 mass% with respect to the emulsion is used in a circulating manner.

  When the dilution concentration of the cold rolling oil for steel sheet is less than 0.5 mass%, the rolling property is lowered, which is not preferable, and when the dilution concentration is more than 15.0 mass%, excessive lubrication is not preferable. In order to maintain the concentration of gear oil mixed in the emulsion below 0.1 mass%, it is not preferable because of high cost, and when it exceeds 5.0 mass%, excessive lubrication is not preferable.

  Note that the cold-rolled oil of the present invention has various additions such as fats and oils, oiliness improvers, extreme pressure additives, antioxidants, preservatives, etc., as long as the effects of the present invention are not impaired. An agent can be added.

  In the present invention, the mechanism for improving lubricity and oil stain resistance when cold rolling a magnetic steel sheet containing Si with a small diameter roll is not clear in detail. The amount of heat to be generated is very large, and it is considered that the alloy film such as Si or Al contained in the oxide film formed on the new surface to be produced exhibits a property different from that of a general steel plate. Therefore, in general rolling oil, the deterioration of emulsion stability proceeds rapidly, and therefore the lubricity is inferior, the generation of oil stains cannot be suppressed, and a specific substance disclosed in the present application is blended in a specific amount. It is thought that stable rolling becomes possible.

  The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Test method for emulsification and emulsion stability]
(1) Preparation of Test Emulsion A test rolling oil (No. 1 to 20) shown in the composition of Table 1 was prepared, and the emulsion was bathed under the following conditions.

Rolling oil concentration: 3 mass%
Built bath amount: 1L
Water used: Deionized water Bath temperature: 60 ° C
Stirring conditions: Homomixer 5500 rpm x 15 min
Iron powder contamination amount: 0 ppm (emulsification) and 1000 ppm (emulsification stability) added to the emulsion Gear oil contamination amount: 3.0 mass% relative to the emulsion

[Emulsification and emulsion stability]
The emulsification was evaluated by the average volume particle size of the emulsion immediately after stirring, and the emulsification stability was evaluated by the rate of change of the average volume particle size when iron powder was added. In addition, the average volume particle diameter was measured in accordance with the electrical resistance test method described in JIS R6002 using a Beckman Coulter Coulter Counter.

Emulsification ○: Average particle size of 6 μm or less Δ: Average particle size of 6-12 μm
X: Average particle size over 12 μm

Rate of change = (average volume particle size when iron powder is added-average volume particle size when no additive is added) / average volume particle size when no additive is added ◎: Less than 0.1 ○: 0.1 to 0.2
Δ: 0.2 to 0.4
Δ to ×: 0.4 to 0.6
×: 0.6 or more

[Lubricity and oil stain resistance test method]
The emulsions prepared in the emulsification and emulsion stability tests were evaluated for lubricity and oil stain resistance.

(2) Preparation of test plate An electromagnetic steel plate (thickness 1.2 mm, width 30 mm, length 100 mm) containing 3.0 mass% Si and 0.3 mass% Al was immersed in the above test emulsion, and then on the steel plate. 1 ml of the emulsion was dropped and rolled under the following conditions. The rolled steel plate was used as a test plate for oil stain resistance test.

Roll: 100 mmφ bright roll Rolling speed: 10 m / min
Reduction ratio: 5-pass rolling, total reduction ratio 50%

Lubricity was evaluated using the rolling load at this time.
○: Maximum rolling load 350N or less △: Maximum rolling load 350-400N
×: Maximum rolling load over 400N

(3) Preparation of sample for oil stain resistance test and acceleration of oil stain The rolled steel sheet is cut into 30 mm × 100 mm, and 0.3 ml of the emulsion is dropped on the surface to form four sheets. Next, the four stacked test pieces are double-wound with aluminum foil, and the four corners are sandwiched with double clips. This was left for 16 hours in an environment of 110 ° C.

(4) Oil stain resistance evaluation criteria The steel plate surface after the above test was wiped with a solvent (diethyl ether), and the oil stain on the test piece was visually evaluated based on the following evaluation criteria.

A: Almost no oil stain is seen.
○: Slight oil stain is observed.
Δ: Oil stain is slightly noticeable.
Δ to ×: oil stain is conspicuous ×: oil stain is conspicuous.

[Gear oil separability]
After adding 20 g of gear oil 1 or gear oil 2 to 400 ml of the test emulsion prepared with the rolling oil shown in Table 1, the mixture was stirred at 5500 rpm for 15 minutes, then transferred to a graduated cylinder, allowed to stand for 20 minutes, and above the emulsion solution. Separation was evaluated by measuring the amount of floating oil phase.

◎: Separation almost completely ○: Obvious oil phase is observed △: The boundary between the oil phase and the aqueous phase is not clear but is floating △ ~ ×: Emulsion can be separated in upper and lower layers by color tone ×: Separation Not

  Table 2 shows the test results of Examples 1 to 9 and Comparative Examples 1 to 11 of the present invention. ◎ and ○ were accepted.

The components shown in Table 1 were as follows.
Oil 1: Naphthenic mineral oil Oil 2: Paraffinic mineral oil E1 (Synthetic ester 1): Oleic acid trimethylolpropane ester (hydroxyl value 257)
E2 (synthetic ester 2): oleic acid sorbitan ester (hydroxyl value 201)
E3 (synthetic ester 3): linoleic acid polyglyceride (hydroxyl value 115)
E4 (synthetic ester 4): palmitic acid glyceride (hydroxyl value 87)
E5 (synthetic ester 5): triisostearic acid diglyceride (hydroxyl value 310)
A1 (amine-based surfactant 1): triethanolamine A2 (amine-based surfactant 2): N-aminopropyl behenylamine A3 (amine-based surfactant 3): polyamine ethylene oxide adduct C1 (carboxylic acid 1): Oleic acid C2 (carboxylic acid 2): alkenylated linoleic acid C3 (carboxylic acid 3): alkylated malonic acid T1 (alkenyl succinic acid): alkenyl succinic acid Gear oil 1: Mineral oil base gear oil (demulsifying 20 minutes)
Gear oil 2: Mineral oil base gear oil (demulsibility 30 minutes)

  In Examples 1 to 9 to which the cold rolling oil of the present invention was applied, oil stain resistance was good. On the other hand, in Comparative Examples 1 and 2 (out of the upper and lower limits of the hydroxyl value of the synthetic ester), sufficient characteristics such as emulsion stability and oil stain resistance were not obtained. In Comparative Example 3 (exceeding the lower limit of the amine surfactant), the emulsion stability was improved. In Comparative Example 4 (exceeding the upper limit of the amine surfactant), the lubricity was improved. In Comparative Example 5 (exceeding the lower limit of the carboxylic acid), the emulsion stability was improved. In Comparative Example 6 (out of the carboxylic acid upper limit), the oil stain resistance was in Comparative Example 7 (No addition of alkenyl succinic acid) and in Comparative Example 8 (out of the lower limit of alkenyl succinic acid addition), the oil stain resistance was Comparative Example 9 ( Synthetic ester addition amount off the lower limit), particularly lubricity, Comparative Example 10 (out of the upper limit of the synthetic ester addition amount) oil stain resistance, Comparative Example 11 (out of the demulsification of the gear oil) gear oil separability , Could not be obtained respectively. In Comparative Examples 3, 4, 6, and 9, the separability of the gear oil was not sufficient.

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

Claims (2)

Mineral oil,
A synthetic ester having a hydroxyl value of 100 or more and 300 or less, synthesized from a fatty acid and a dihydric or higher alcohol, and 5 to 30% by mass relative to the total mass;
An amine-based emulsifier that is 3 to 10 mass% based on the total mass;
An aliphatic or aromatic carboxylic acid (excluding succinic acid) or an aliphatic or aromatic carboxylic acid derivative that is 1.0 to 5.0 mass% with respect to the total mass;
One or more oil-soluble alkenyl succinic acid or alkenyl succinic acid derivative of 0.1 to 5.0 mass% with respect to the total mass;
As an essential component ,
The aliphatic or aromatic carboxylic acid derivative is obtained by alkylating or alkenylating the aliphatic or aromatic carboxylic acid (excluding succinic acid) to make it oil-soluble,
Cold-rolling oil for steel sheet, which is used when gear oil mixed with demulsibility of 25 minutes or less is mixed . The emulsion prepared by diluting the cold-rolled oil according to claim 1 is adjusted in such a manner that the mixing amount of the gear oil having a demulsibility of 25 minutes or less is 0.1 to 5.0 mass%. Cold rolling method.