JP2003170207A - Method for rolling metal plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for rolling a metal plate capable of easily supplying an oil-in-water type rolling oil having the most proper lubricating performance for workability of each metal plate when a variety of metal plates with different workability are rolled by the same rolling mill. <P>SOLUTION: The method for rolling the metal plate is characterized in that the method includes a process to separate into an emulsion of the oil-in-water type of the oil content having required lubricating performance and other mixers by centrifugally separating all or a part of the oil-in-water type emulsions, and a process to use other mixers and the nonseparable oil-in-water type emulsions as rolled cooling water, while using the emulsions of the oil-in-water type after separation as the rolling oil, and centrifugal separation is performed under the conditions that the accumulative 80% particle size from the small particle size side of dispersion oil spot included in the emulsions of the oil-in- water type after separation is less than twofold against the accumulative 80% particle size from the small particle size side of dispersion oil spot included in the emulsions of the oil-in-water type at bathing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling a metal plate using an oil-in-water emulsion as a rolling oil.

[0002]

2. Description of the Related Art A metal plate such as an Al plate, an Al alloy plate, and a steel plate is manufactured to have a desired thickness through hot rolling and cold rolling. When rolling such a metal plate, the deformation heat and friction heat generated are cooled,
Further, rolling oil is used for the purpose of imparting lubricity in order to reduce the amount of frictional heat generated per se.

As the above rolling oil, a mineral oil is usually used as a base oil, and an oiliness improver such as a fatty acid, an oil and a fatty acid ester, an extreme pressure agent, a rust preventive, an antioxidant, etc. are added to these base oils. An oil-in-water emulsion having a concentration of 3 to 10% and an oil particle size of about 1 to 3 μm, which is mainly emulsified with an anionic surfactant, is used.

Since the oil-in-water emulsion uses water as a medium, it has a larger cooling capacity than that of the oil alone, and can suppress the enlargement of the crystal structure of the metal sheet rolled along with the cooling of the equipment. To facilitate control of mechanical strength by rolling, during rolling, the temperature of rolling oil becomes extremely high due to heat generated by deformation of the metal plate and frictional heat,
Although there is concern that a fire may occur due to the combustion of the rolling oil, the oil-in-water emulsion is nonflammable because the medium is water, and there is almost no risk of fire. Since it is used after being diluted with, it has many advantages such as low oil consumption.

By the way, in the rolling of a metal plate, it is desired that the grain size, the oil concentration, and the blending composition correspond to the characteristics of the metal plate to be processed. Therefore, when rolling a variety of metal sheets with the same rolling mill, it is preferable to supply different rolling oils for each condition, but for that purpose, a plurality of oil supply systems (tanks, tanks,
Since a pump, a supply pipe, a recovery pipe, etc.) are required, the equipment becomes complicated and its cost becomes excessive. Also,
It is extremely difficult to maintain the optimum oil condition because different rolling oils are mixed with each other in a common portion such as a rolling oil supply pipe to a roll. Under these circumstances, the same rolling oil is usually used under the different processing conditions.

[0006] However, for example, 50 is poor in workability.
In the finish hot rolling of the 00 series Al alloy plate, biting property and high lubricity are required, but if a rolling oil having an optimized composition according to such materials is used for the 1000 series Al alloy plate, Excessive lubrication will occur. Conversely, 1
If the optimum rolling oil for the 000 series Al alloy plate is used for the 5000 series Al alloy plate, the lubricity becomes insufficient, the load increases, and the plate surface quality deteriorates. Therefore, even if there is a rolling oil suitable for processing a 5000 series Al alloy plate, it is necessary to process another material with the same rolling mill, so that the lubrication performance of the 5000 series Al alloy is suppressed by intentionally suppressing the lubricity. There was a need to strike a balance.

Several techniques have been proposed as methods for solving these problems. For example, JP-A-7-417
Japanese Patent Laid-Open No. 90 discloses a technique in which a specific oil-water separation type rolling oil is poured into water to form an aqueous emulsion and then supplied to a rolling roll. In this technique, the oil concentration can be adjusted by changing the rolling oil / water mixing ratio at the time of injection. However, this technique is not always efficient because the rolling oil must be poured into water in the system to prepare an aqueous emulsion. Also, since it is an oil-water separation type rolling oil, it is necessary to mix it by mechanical stirring to adjust the dispersed oil droplet particle size immediately before use, and the rolling oil / water after mixing is used as is for rolling. Is virtually impossible to do.

The inventors of the present invention also disclosed in Japanese Patent Laid-Open No. 10-158.
Japanese Patent No. 679 discloses a technique in which a water-dispersed rolling oil mixed with a cationic polymer compound is used to optimize the oil concentration according to the material temperature. However, even with this technique, there is still room for improvement in terms of speed in responding to changes in material temperature due to changes in the material to be processed.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to roll a wide variety of metal sheets having different workability with the same rolling mill. It is an object of the present invention to provide a rolling method for a metal plate, which can easily supply an oil-in-water rolling oil having an optimal lubricating performance for the workability of the metal plate.

[0010]

[Means for Solving the Problems] The rolling method of a metal plate of the present invention (hereinafter, simply referred to as “rolling method”) capable of achieving the above object is to use an oil-in-water emulsion as rolling oil. In the method for rolling a metal plate, (A) the whole or a part of the oil-in-water emulsion is centrifuged to separate it into an oil-in-water emulsion having an oil concentration having a required lubricating performance and another mixed solution. And the step (B)
The step of using the oil-in-water emulsion after separation as a rolling oil, using the other mixed liquid and the oil-in-water emulsion that does not separate as roll cooling water, and performing the centrifugal separation after the separation. From the small particle size side of the dispersed oil drops contained in the oil-in-water emulsion, the cumulative particle size of 80% is X (μm), from the small particle size side of the dispersed oil-drops contained in the oil-in-water emulsion at the time of bathing The cumulative particle size of 80% is Y (μ
In the case of m), the essential point is that it is carried out under the condition of X / Y <2 below.

The above-mentioned "other mixed liquid" is an oil-in-water emulsion before separation, which is prepared by centrifuging to prepare an oil-in-water emulsion having an oil concentration suitable as a rolling oil.
This is the remaining part excluding this, and the "other mixed liquid" itself is also an oil-in-water emulsion.

Further, in the rolling method of the present invention, (C) the used rolling oil and the roll cooling water are recovered,
It is preferable to include a step of supplying all or a part thereof to the centrifugation step.

The rolling method of the present invention comprises a rolling roll,
It can be carried out using a rolling mill having one unit including a backup roll and a centrifugal separator, and can also be carried out using a rolling mill having two or more sets of the unit (so-called tandem mill rolling mill). is there.

The oil-in-water emulsion used in the rolling method of the present invention has, as an oil component, (a) a mineral oil having a viscosity at 40 ° C. of 80 cSt or less: 50
To 96.4 parts by mass, (b) at least one compound selected from the group consisting of fatty acids, fats and oils and monoesters of fatty acids and alcohols: 30 to 3 parts by mass, (c) carbon number of 4 to 18 At least one kind of phosphoric acid ester or phosphorous acid ester having an alkyl group or an alkenyl group of: 10 to 0.5 parts by mass, (d) the following general formula (1)

[0015]

[Chemical 2]

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² and R ³ are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, m is 0 or 1, and n is an integer of 1 to 3). Is a copolymer of one or more of the monomers represented by the formula (1) and (meth) acrylamide and / or (meth) acrylic acid salt, and has an average molecular weight of 10,000 to 1,000,0.
The following general formula (2) R ⁴ COOH (2) (wherein R ⁴ is an alkyl group having 1 to 5 carbon atoms or a hydroxyalkyl group, or an alkyl moiety having 1 carbon atom) ~
5, a salt with an organic acid represented by a carboxyalkyl group or a carboxyl group): 10 to 0.1 parts by mass is recommended.

The centrifugation conditions are 100 to 3
It is preferably 000G.

The rolling method of the present invention as described above can be preferably adopted for finish rolling of a metal plate, and is suitable for hot rolling of an Al plate or an Al alloy plate.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The rolling method for a metal sheet of the present invention includes the above steps (A) and (B), and has the greatest feature in controlling the centrifugation conditions in the step (A). .

In rolling a specific type of metal plate, the oil content of the oil-in-water emulsion used as rolling oil is adjusted in advance to a level at which the lubricating performance required for rolling the metal plate can be exhibited. can do. However, when the same rolling mill is used to roll a metal sheet of a different type from the above, the lubricating performance required for rolling oil is often different.

Therefore, when different types of metal sheets are rolled by the same rolling mill, as described above, the same oil-in-water emulsion is used as the rolling oil regardless of the difference in the workability of the metal sheets. A method or a method in which the emulsion is completely separated into water and oil, an emulsion having a desired oil concentration is prepared, and used as a rolling oil (for example, JP-A-7-41790) is employed. In contrast to these conventional techniques, in the rolling method of the present invention, the supplied oil-in-water emulsion is subjected to centrifugal separation, and an oil-in-water emulsion having an oil concentration capable of exhibiting lubricating performance according to the type of metal plate to be rolled. And used as it is for rolling oil.

However, depending on the above centrifugation conditions, a plurality of dispersed oil droplets in the oil-in-water emulsion contact each other to form one oil droplet, and as a result, in the oil-in-water emulsion after separation, The particle size of the dispersed oil droplets may be enlarged.

When the dispersed oil droplet size in the oil-in-water emulsion separated in the step (A) becomes too large, the emulsion is fed as rolling oil near the metal plate to be rolled [step (B) above]. ], The amount of oil introduced into the roll bite increases, and the rolled metal plate may slip. Also, when locally enlarged oil droplets enter the roll bite in a non-uniform state in the width direction of the metal plate (roll width direction), uneven thickness of the oil film locally occurs, and the metal after rolling is rolled. Appearance spots appear on the surface of the board.

Conventionally, in the method for rolling a metal sheet having the above-mentioned steps (A) and (B), it was extremely difficult to roll the metal sheet satisfactorily due to the above problems, but in the method of the present invention. It is possible to adjust the various conditions in each step and to perform the centrifugation in the step (A) under the condition of "X / Y <2", thereby solving the problem.

In the rolling method of the present invention, the centrifugal separation condition of the step (A) is such that the cumulative oil particle size X of the dispersed oil droplets contained in the oil-in-water emulsion after separation is 80% from the small particle diameter side. , And of the dispersed oil droplets contained in the oil-in-water emulsion at the time of building the bath are controlled by the cumulative particle size Y from the small particle size side to the dispersion in the oil-in-water emulsion at the time of building the bath. This is because, among the oil droplets, the particle size in the vicinity of the cumulative 80% from the small particle size side is most likely to change due to the above-mentioned centrifugation, and the above-mentioned problem is likely to occur when the particle size is enlarged.

In the step (A) of the rolling method of the present invention,
Centrifugation must be done under conditions where the "X / Y" value is less than 2. If the "X / Y" value is less than 2, in the process of supplying the oil-in-water emulsion after separation to the rolling roll as a rolling oil, the oil-in-water emulsion may become an inner wall surface of a pipe through which the oil-in-water emulsion passes. Due to shearing or shearing with the inner wall surface of the spray nozzle when spraying the oil-in-water emulsion as a rolling oil onto a rolling roll, the dispersed oil-droplet particle size in the oil-in-water emulsion is reduced to some extent. , The particle size of dispersed oil droplets in the oil-in-water emulsion actually sprayed on the rolling rolls is almost the same as the dispersed oil droplet size in the oil-in-water emulsion at the time of building bath. it is conceivable that.

In the step (A), the concentration of oil in the oil-in-water emulsion after centrifugation can be changed. Therefore, using the same rolling mill, even when rolling a wide variety of metal sheets with different workability,
From the same oil-in-water emulsion, it is possible to easily obtain an oil-in-water emulsion having an oil concentration capable of imparting suitable lubricity to each metal plate, and this can be supplied to a rolling roll as a rolling oil. . The above "X / Y" value is
It is recommended to centrifuge under conditions of less than 1.7, more preferably less than 1.5.

Furthermore, in the rolling method of the present invention, in addition to the above steps (A) and (B), the above step (C),
That is, it is recommended to include a step of collecting the used rolling oil and roll cooling water, and supplying all or a part thereof to the centrifugation step [(A) step].

The used rolling oil is an oil-in-water emulsion, and the used roll cooling water is an oil-in-water emulsion or water (described later). Therefore,
By collecting these together and subjecting them to the centrifugation in the step (A), it is possible to circulate and reuse the oil-in-water emulsion semipermanently in the system for carrying out the rolling method of the present invention. Become.

As a conventional technique for recovering and reusing such rolling oil, for example, the one described in the above-mentioned JP-A-7-41790 can be cited. However, in this technique, the rolling oil / water mixed solution recovered after use is completely separated into rolling oil and water, and the rolling oil is injected into water to prepare an aqueous emulsion again, so that it is reused after each reuse. Aqueous emulsions must be prepared and are not always efficient.

On the other hand, in the rolling method of the present invention including the above steps (A), (B) and (C), if the centrifugal separation condition in the step (A) is within the above predetermined range, oil-in-water Since re-adjustment of the dispersed oil droplet particle size in the droplet emulsion is substantially unnecessary, the circulation and reuse of the oil-in-water emulsion in the system can be performed very efficiently. It should be noted that the above-mentioned "re-adjustment of the particle size of dispersed oil droplets in an oil-in-water emulsion is substantially unnecessary" means that dispersed oil that is necessary due to some unexpected situation or long-term suspension of rolling operation. This means excluding readjustment of the drop particle size.

FIG. 1 shows an example of a preferred embodiment of the rolling method of the present invention including the steps (A), (B) and (C). In FIG. 1, a: a pipe through which the oil-in-water emulsion before centrifugation passes, b: a pipe through which an oil-in-water emulsion after centrifugation passes, and c: a pipe through which another mixed liquid after centrifugation passes. Is.

An oil-in-water emulsion having an oil concentration and a dispersed oil droplet particle size adjusted is placed in a supply tank 5, and the emulsion is supplied to a centrifugal separator 8 by a pump 7. The oil-in-water emulsion is centrifugally separated by the centrifugal separator 8 to separate the oil-in-water emulsion having a desired oil concentration into another mixed solution [(A) step].

The separated oil-in-water emulsion after separation is supplied to the rolling roll 1 to be used as rolling oil, and the above-mentioned other mixed liquid after separation is supplied to the backup roll 2 as roll cooling water (for example, Spraying from the spray nozzle onto the roll surface) [(B) step].

The used rolling oil and the other mixed liquid are collected together, stored in the primary receiving tank 4, and further sent to the supply tank 5 by the pump 7. By supplying the recovered oil-in-water emulsion in the supply tank 5 to the centrifugal separator 8 [step (C)], the oil-in-water emulsion can be circulated and reused in the system.

The oil content concentration of the oil-in-water emulsion in the step (A) is adjusted as follows. The (recovered) oil-in-water emulsion is separated by the centrifugal separator 8 into a light liquid having an extremely high oil concentration and a heavy liquid having an extremely low oil concentration (containing almost no oil). This light liquid and the amount of heavy liquid necessary for diluting to the desired oil concentration are taken out and used as rolling oil (oil-in-water emulsion), and the rest of the heavy liquid is used as roll cooling water (other mixed liquid). To use.

Some of the light and heavy liquids used for rolling oil are
It is mixed while passing through the piping b to form an oil-in-water emulsion having a desired oil content. Further, after centrifugation, a part of the extracted light liquid and a part of the heavy liquid may be mixed at a level at which the dispersed oil droplet particle size is not adjusted, and the composition of the rolling oil may be made more uniform and then supplied to the rolling roll. .

The centrifuge which is the main component of the centrifuge 8 is preferably one which can continuously process (recovered) oil-in-water emulsion, for example, wet cyclone, coalescer (manufactured by Mitsubishi Kakoki Co., Ltd.) and the like. Can be used.

In the rolling mill used in the rolling method of the present invention, as shown in FIG. 1, in order to remove metal powder, oil waste, etc. in the recovered oil-in-water emulsion, the primary receiving tank 4 has It is preferable to install the filter 6 before and / or after. The capacity of the filter used (for example, the ability to remove foreign matter and the amount of processing liquid per unit time)
Depending on the situation, the primary receiving tank 4 may not be provided. Depending on the processing capacity of the centrifugal separator 8, it is possible to directly supply the recovered oil-in-water emulsion to the centrifugal separator 8 without providing the supply tank 5.
As shown in FIG. 1, it is common to use a rolling mill provided with a primary receiving tank 4 and a supply tank 5.

Further, during rolling, the oil component (and water) in the oil-in-water emulsion adheres to the metal plate to be rolled, and it goes out of the system. Therefore, as the number of times of rolling advances, the amount of oil (and the amount of water) in the system decreases, and it becomes necessary to replenish the system with new oil (and the amount of water). In this case, it is common to replenish the supply tank 5 with the required amount of oil (and water) based on the amount of oil (and water) remaining in the system. In order to mix with the oil-in-water type emulsion present in 1., the supply tank 5 is preferably equipped with a stirring device (not shown). However, since the dispersed oil droplet particle size of the oil-in-water emulsion is not adjusted in the supply tank 5, a stirring device such as a propeller capable of making the oil concentration uniform may be provided.

As the roll cooling water, an oil-in-water emulsion that has not been separated may be used as it is in addition to the above-mentioned other mixed liquid after centrifugation, and water containing no oil is supplied from outside the system. You may use it. However, when water is used, if it is collected together with the oil-in-water emulsion used as a rolling oil, the oil content ratio in the system decreases, and since the total amount of oil-in-water emulsion in the system increases, It may interfere with storage and centrifugation. Therefore, it is desirable to control the amount of water supplied from outside the system so that such problems do not occur. For example, after rolling operation,
Water is supplied from outside the system for a predetermined time and used as roll cooling water, and after that time, the supply of water from outside the system is stopped, and the other mixed liquid or oil-in-water emulsion not separated is roll-cooled. It may be used as water.

Further, depending on the required lubricating performance, the oil-in-water emulsion at the time of construction or after recovery may be used as rolling oil without centrifugal treatment, so that it may be passed from the supply tank 5 through the centrifugal separator 8. Alternatively, a pipe for directly supplying to the pipe B may be separately provided.

Although FIG. 1 shows an example in which the roll cooling water is supplied only to the backup roll 2, it is also preferable to supply the roll cooling water to the rolling rolls as shown in FIG. 2 described later. .

As shown in FIG. 1, the rolling method of the present invention can be carried out using a rolling mill having one unit including a rolling roll, a cooling roll and a centrifugal separator, or two rolling units. It is also possible to use the rolling mill (tandem mill rolling mill) having the above.

For example, in the finish rolling of a metal plate, a tandem mill system for rolling continuously in a plurality of units as shown in FIG. 2 is adopted. The speed is different for each unit, and the required lubrication state is also different for each rolling stage from the upper stage to the lower stage. Therefore, it is preferable to supply an appropriate rolling oil according to the lubrication state at each stage, but as a conventional problem when it is necessary to cope with rolling of various metal plates using the same rolling mill, For the same reason as I did, I had to deal with the same rolling oil.

However, in the rolling method of the present invention, as described above, the oil concentration in the oil-in-water emulsion after centrifugation can be adjusted in the step (A).

Therefore, from one oil-in-water emulsion, an oil-in-water emulsion having an oil concentration capable of imparting suitable lubricity according to each stage of rolling is prepared for each unit and used as rolling oil. It can be used.

As an example of a preferred embodiment of the rolling method of the present invention, the case of using a rolling mill having five sets of the above units is shown in FIG. In FIG. 2, the pipes a, b and c are
All are the same as in FIG.

In FIG. 2, the oil-in-water emulsion separated by the centrifugal separator 8 of each unit is used as the rolling oil, and the other mixed liquid after the separation is used as the cooling water for the rolling rolls. The oil-in-water emulsion that does not undergo centrifugal separation is used as it is for the cooling water of the backup roll.

In the rolling method of FIG. 2, the first (#
1) In the unit, since it is necessary to improve the biting of the metal plate 3 into the rolling roll 1, the centrifugal separator 8 is used to prepare an oil-in-water emulsion having a low oil concentration and a low lubricating performance, and then rolling the emulsion. Use it for oil and use another mixed liquid after separation (high oil content) for roll cooling water, or supply an oil-in-water emulsion with low oil content and low lubrication performance to the system beforehand. It is preferred to use this for rolling oil and roll cooling water without centrifugation.

On the other hand, the second (# 2) to the fifth (# 5)
In the unit, in order to improve the surface quality of the metal plate 3,
It is possible to prepare an oil-in-water emulsion having a high oil content and a high lubricating performance by the centrifugal separator 8 and use it as a rolling oil, and use another mixed liquid after separation (low oil content) for roll cooling water. preferable.

Since it is preferable that the amount of oil content in the oil-in-water emulsion adhered to the surface of the metal plate 3 to be wound up after the rolling of all stages is completed, the final stage of rolling (in FIG. 5 units), a low oil concentration oil-in-water emulsion may be used as the rolling oil.

Further, FIG. 2 shows an example in which an oil-in-water emulsion which is not centrifuged is used as cooling water for a backup roll, but as described in FIG. Water may be used as cooling water. The same applies to the cooling water for the rolling rolls. However, when water is supplied from outside the system, attention should be paid to the problems described in the explanation of FIG.

It should be noted that FIGS. 1 and 2 merely show one example of the embodiment of the present invention, and the method of the present invention is not limited to these.

In the rolling method of the present invention, the centrifugation conditions in the step (A) are specifically 100 G or more, preferably 500 G or more, and 3000 G or less, preferably 1000 G or less. To be done. "X /
The centrifugation conditions that allow the Y value to be in the above range are affected by the centrifuge used, the type of oil-in-water emulsion, the centrifugation time, etc., but if the centrifugal force is controlled within the above range, it will be easy. The "X / Y" value can be within the above range. That is, if the centrifugal separation condition is less than 100 G, enlargement of the dispersed oil droplet particle size can be suppressed, but the separation of oil droplets becomes insufficient. On the other hand, if it exceeds 3000 G, the dispersed oil droplet particle size tends to be enlarged.

The above-mentioned preferable centrifugal separation conditions (centrifugal force) are as follows: thickness and shape of the pipe in which the oil-in-water emulsion is circulated in the rolling mill used in the present invention, rolling oil to a rolling roll (after centrifugation) Depending on the shape of the spray nozzle for spraying (oil-in-water emulsion) and the capacity of the circulating pump used, the shearing force between the inner wall surface of these pipes and spray nozzle and the oil-in-water emulsion Since they are different, there may be some variation.

The oil-in-water emulsion according to the rolling method of the present invention comprises a base oil known as a rolling oil to which a dispersant (surfactant) for forming the oil as a dispersed oil is added. It is contained as. The base oil used for this oil component, the dispersant, etc. are not particularly limited as long as it can exhibit the action of the present invention, it is possible to provide a rolled plate having excellent lubrication performance and emulsion stability and good surface quality. ,
Furthermore, since there is little heat deterioration with long-term use,
Those containing the above components (a) to (d) as an oil component are preferably used. Hereinafter, each component of the oil-in-water emulsion suitable for the rolling method of the present invention will be described.

Examples of the mineral oil as the component (a) include spindle oil, machine oil, cylinder oil, neutral oil and the like, and paraffinic mineral oil is recommended from the viewpoint of heat resistance and lubricity. The viscosity of mineral oil is preferably 80 cSt or less at 40 ° C. Viscosity 80c
If it exceeds St, the quality of the surface of the metal plate after rolling tends to deteriorate.

The component (a) is a base oil, and its blending amount is not particularly limited, but it is 50 parts by mass or more, preferably 60 parts by mass or more, and 96.4 parts by mass or less, preferably in total oil content. Is recommended to be 85 parts by mass or less.

Among the components (b), oils and fats include whale oil,
Animal and vegetable oils such as beef tallow, pork oil, rapeseed oil, castor oil, palm oil and coconut oil can be mentioned. The fatty acid preferably has 10 to 22 carbon atoms, and specifically,
Examples thereof include capric acid, lauric acid, stearic acid, isostearic acid, oleic acid and erucic acid. As the fatty acid monoester, a fatty acid having 10 to 22 carbon atoms,
Monoesters with alcohols having 1 to 22 carbon atoms (for example, aliphatic monohydric alcohol, ethylene glycol, trimethylolpropane, pentaerythritol, glycerin, etc.) are preferable, and specifically, methyl caprate,
Examples thereof include butyl stearate, laurate oleate, 2-ethylhexyl erucate, penterythritol monooleate and glycerin monooleate.

These components (b) act as an oiliness improver and can be used alone or in combination of two or more. It is recommended that the added amount is 3 parts by mass or more, preferably 10 parts by mass or more, and 30 parts by mass or less, preferably 25 parts by mass or less in the total oil content.
If the amount of component (b) is less than the above range, the lubricity decreases.
On the other hand, if it exceeds the above range, the quality of the surface of the rolled metal sheet deteriorates. When fats and oils are used, the upper limit of the amount added is more preferably 20 parts by mass.

Specific examples of the phosphoric acid ester or phosphite ester having an alkyl group or an alkenyl group having 4 to 18 carbon atoms as the component (c) include dibutyl phosphate, monooctyl phosphate, trioleyl phosphate and tributyl phosphate. Examples thereof include phyto, diisooctyl phosphite and trioleyl phosphite. Among such monoesters, diesters or triesters, alkyl or alkenyl acid phosphates which are monoesters or diesters, or alkyl or alkenyl acid phosphites are particularly preferable.

The amount of the component (c) added is 0.5 in the total oil content.
It is recommended that the amount is not less than 1 part by mass, preferably not less than 1 part by mass and not more than 10 parts by mass, preferably not more than 5 parts by mass. This is because if the amount is less than the above range, the quality of the rolled metal plate surface is not improved, and if the amount exceeds the above range, further improvement in the metal plate surface quality due to the increase cannot be expected.

Examples of the polymer compound as the component (d) include copolymers of the monomer of the above formula (1) and (meth) acrylamide and / or (meth) acrylic acid salt.
Specific examples of the monomer of the above formula (1) are as follows: m = 1, dimethylaminoethylacrylamide, dimethylaminopropylacrylamide, diethylaminomethylacrylamide, dimethylaminoethylmethacrylamide, dimethylaminopropylmethacrylamide, diethylaminomethyl. Methacrylamide and the like can be mentioned.
Examples of m = 0 include allylamine, dimethylaminomethylethylene, diethylaminomethylethylene, dimethylaminomethylpropene, and diethylaminomethylpropene. Of these, m = 1
Particularly preferred are dimethylaminopropyl methacrylamide and dimethylaminopropyl acrylamide.

Examples of the (meth) acrylate include (meth)
(Meth) acrylic acid alkali metal salts such as sodium acrylate and potassium (meth) acrylate; (meth) acrylic acid monoethanolamine salts, (meth) acrylic acid diethanolamine salts, (meth) acrylic acid triethanolamine salts, etc. Examples thereof include (meth) acid organic amine salts.

The high molecular compound of the component (d) has an average molecular weight of 10,000 or more, preferably 30,000 or more and 1,000,000 or less, preferably 30.
It is 50,000 or less. If the average molecular weight is less than this range, the emulsion stability of the oil-in-water emulsion is low, and if it exceeds this range, the stability of the polymer compound itself is poor, and the viscosity becomes high, which makes handling difficult.

In the above formula (2) showing an organic acid for forming a salt with the polymer compound as the component (d), R ⁴ is an alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl having 1 to 5 carbon atoms. Examples thereof include a carboxyalkyl group having a carbon number of 1 to 5 in the alkyl moiety and a carboxyl group, and a hydroxyalkyl group having a carbon number of 1 to 5 is particularly preferable. R
Specific examples of ⁴ COO ⁻ include acetate ion, propionate ion, valerate ion, caproate ion, glycolate ion, lactate ion, hydroacrylate ion, oxalate ion, malonate ion, succinate ion, glutarate. Examples thereof include an ion and an adipate ion, but a glycolate ion, a lactate ion, and a hydroacrylate ion are particularly preferable.

In producing the above-mentioned polymer compound,
It is preferable that the monomer of the formula (1) is polymerized and then neutralized with the organic acid of the formula (2), but the monomer of the formula (1) is previously neutralized with the organic acid of the formula (2). You may polymerize things. For example, the component (d) can be obtained by copolymerizing a glycolic acid neutralized product of dimethylaminopropyl methacrylamide with another copolymerizable monomer.

The organic acid salt of the polymer compound as the component (d) may be used alone or in combination of two or more, and the total amount thereof is 0.1 parts by mass or more, preferably at least 0.1 part by mass in the total oil content. Is 0.5 parts by mass or more and 10 parts by mass or less, preferably 5 parts by mass or less is recommended. If these are less than the above range, the effect is not sufficiently exerted, and if it exceeds the above range, the oil droplet particle size becomes too small, the pressure resistance load performance of the rolling oil becomes small, and the seizure resistance decreases. Not preferable.

In the oil-in-water emulsion, in addition to the oil, known additives such as rust / corrosion inhibitors, antioxidants, and emulsifiers for improving the initial emulsifying property may be added as required. It is also possible to add. Examples of the rust / corrosion preventive agent include alkenyl succinic acid and its derivatives,
Fatty acids such as oleic acid, esters such as sorbitan monooleate, and other amines can be used. Examples of the antioxidant include 2,4-di-ter.
Phenolic compounds such as t-butyl-p-cresol and aromatic amines such as phenyl-α-naphthylamine can be used. As the emulsifier, for example, an anionic surfactant such as oleic acid triethanolamine salt or petroleum sulfonate sodium salt, or a nonionic surfactant such as polyoxyethylene nonylphenyl ether can be used. These rust / corrosion inhibitors, antioxidants and emulsifiers can be added to the above oil components in an amount of 2 parts by mass, 5 parts by mass and 2 parts by mass, respectively.

The above oil is diluted with water before use. The dilution ratio at this time is not particularly limited and may be appropriately selected depending on the type of the metal plate to be rolled, etc., but normally the oil content in the oil-in-water emulsion is 1 to 30% by volume. Is preferred.

Such an oil component has an appropriate particle size and heat resistance due to the electric aggregation effect, steric hindrance effect, protective colloid effect and high heat resistance of the organic acid salt of the high molecular compound of component (d). Even under severe use conditions such as hot rolling, its uniform emulsification dispersibility and particle size distribution can be kept stable for a long time, so that good rolling lubricity at the initial stage of use can be maintained for a long time. Further, the roll coating becomes uniform and thin due to the roll coating suppression effect of the component (b) oiliness improver and the uniform wetting effect of the organic acid salt of the polymer compound (d). The plate has a uniform surface and few defects.

As described above, the rolling method of the present invention is usually
Since it can be preferably applied to a tandem mill type rolling mill used for finish rolling of metal sheets, it is also suitable as a finish rolling method for metal sheets.

In the rolling method of the present invention, the metal plate to be rolled is not particularly limited, and an Al plate, an Al alloy plate,
It can be applied to the rolling of steel plates, copper plates, etc.
It is suitable for rolling 1 plate and Al alloy plate (especially hot rolling).

Other rolling conditions in the case of applying the rolling method of the present invention include the conditions adopted in ordinary rolling, depending on the type of metal plate to be rolled, the thickness of the metal plate before and after rolling, etc. It may be selected appropriately.

[0076]

EXAMPLES The present invention will be described in detail below based on examples. However, the following examples do not limit the present invention, and all modifications and implementations are included in the technical scope of the present invention without departing from the spirit of the above and the following. The "parts" shown below are based on mass unless otherwise specified.

Using a rolling mill of the type shown in FIG. 1 (rolling roll diameter: 300 mm), the roll surface temperature was heated to 80 ° C. and heated to 420 ° C. according to “JIS 5052”.
An Al alloy plate "(length: 550 mm, width: 20 mm, thickness: 5.0 mm) is rolled at a rolling speed of 160 m / min and a rolling reduction of 4
It was hot rolled at 0%.

For the hot rolling, an oil-in-water emulsion containing the components shown in Table 1 was used. This oil-in-water emulsion contains the components shown in Table 1 at an oil concentration of 4%.
(Volume%, same below), average particle size of dispersed oil droplets is about 10μ
It was prepared by stirring at 60 ° C. using a homogenizer so that the amount becomes m.

The average particle size of the dispersed oil droplets and the average particle size of the dispersed oil droplets after centrifugation, which will be described later, are determined by a laser diffraction particle size analyzer ("Microtrac 2" manufactured by Leeds and Northrup). Is the volume average value measured by using.

[0080]

[Table 1]

The centrifugation conditions in the step (A) are 500 G, 1
The treatment time was 1 to 2 minutes at 000 G and 5000 G.

The particle size distribution of the dispersed oil droplets in the oil-in-water emulsion when the above oil-in-water emulsion is supplied to the supply tank and centrifuged under the above conditions is shown in FIGS. The oil concentration after separation was 7.5 to 8.5% for light liquid and 0.2 for heavy liquid under any centrifugation conditions.
It was 5% or less.

When centrifugation is performed under the conditions of 500 G and 1000 G, the cumulative 80% particle size from the small particle size side is
Cumulative from the small particle size side of oil-in-water emulsion during bath building 8
It is less than twice the particle size of 0%, which satisfies the requirements of the present invention. After centrifugation under the conditions of 500 G and 1000 G, oil-in-water emulsions having oil concentrations of 2%, 4%, and 8% were obtained. All of these were suitable as rolling oil for Al alloy plates.

On the other hand, when the centrifugation is performed under the condition of 5000 G, both the centrifugation time of 1 minute and the centrifugation time of 2 minutes are twice or more, which does not satisfy the requirements of the present invention. The oil-in-water emulsion obtained by centrifugation under these conditions was unsuitable as a rolling oil for Al alloy plates.

[0085]

The present invention is configured as described above,
When rolling a wide variety of metal sheets with different workability on the same rolling mill, by separating the oil-in-water emulsion as rolling oil under specific centrifugal conditions to obtain the required oil concentration, each metal It has become possible to provide a rolling method for a metal plate that can easily supply an oil-in-water emulsion having an optimal lubricating performance for plate workability.

By adopting the above centrifugal separation conditions, the used oil-in-water emulsion (rolling oil) can be used.
When the oil-in-water emulsion used as rolling oil and roll cooling water is circulated in the system and reused, including the step of recovering the roll cooling water and the roll cooling water, and supplying it to the centrifugal separation step. Re-adjustment of the dispersed oil droplet particle size in the drop emulsion has become virtually unnecessary.

Further, the rolling method of the present invention can be applied to a tandem mill type rolling mill. In this case, an oil-in-water type emulsion having an optimum oil content is used as a rolling oil according to each rolling stage. Can be supplied. Therefore, unlike the conventional, it does not require a plurality of rolling oils and its circulation system,
The rolling mill can be simplified.

[Brief description of drawings]

FIG. 1 is an explanatory view of a rolling method of the present invention using a rolling mill having one unit including a rolling roll, a backup roll and a centrifugal separator.

FIG. 2 is an explanatory diagram of a rolling method of the present invention using a rolling mill having five sets of units including rolling rolls, backup rolls, and a centrifugal separator.

FIG. 3 is a graph showing the distribution of dispersed oil droplet particle size in an oil-in-water emulsion that has been centrifuged at 500 G.

FIG. 4 is a graph showing the distribution of particle size of dispersed oil droplets in an oil-in-water emulsion that has been centrifuged at 1000 G.

FIG. 5 is a graph showing the distribution of particle size of dispersed oil droplets in an oil-in-water emulsion that has been centrifuged at 5000 G.

[Explanation of symbols]

1 rolling roll 2 backup roll 3 metal plates 4 Primary receiving tank 5 supply tanks 6 filters 7 pumps 8 Centrifuge 9 three-way valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C10M 101/02 C10M 101/02 129/26 129/26 129/70 129/70 137/02 137/02 137 / 04 137/04 149/18 149/18 159/08 159/08 173/00 173/00 // C10N 20:02 C10N 20:02 40:24 40:24 Z (72) Inventor Masahiro Hata Maoka, Tochigi Prefecture 15 Kinugaoka, Ichi, Kamito Steel Works Co., Ltd. in Moka Works (72) Inventor Masanori Ikeda 15 Kinugaoka, Moka City, Tochigi Prefecture Kamito Steel Works, Ltd. in Moka Works (72) Inventor Hironobu Nakanishi Nishi Ward, Kobe City Takatsukadai 1-5-5 Stock Company Kobe Steel Works Kobe Research Institute F-term (reference) 4E002 AA08 AD04 BC08 CB09 4H104 AA01Z BB14C BB15C BB19C BB22C BH02C BH03C CE13C DA02A DA06C EA02A PA23 QA03

Claims (6)

[Claims] 1. A method for rolling a metal plate using an oil-in-water emulsion as rolling oil, wherein all or part of the oil-in-water emulsion is centrifuged to obtain water having an oil concentration having a required lubricating performance. Oil drop type emulsion, a step of separating into another mixed liquid, and the oil-in-water emulsion after separation as the rolling oil, the other mixed liquid and the oil-in-water emulsion not separated as the roll cooling water The step of using, and performing the centrifugation, the cumulative 80% particle size of the dispersed oil droplets contained in the oil-in-water emulsion after separation from the small particle size side is X (μm), Rolling of a metal plate, which is performed under the condition of X / Y <2, where Y (μm) is a cumulative particle size of 80% from the small particle size side of dispersed oil drops contained in an oil drop type emulsion. Method. 2. The method of rolling a metal plate according to claim 1, further comprising a step of recovering the used rolling oil and the roll cooling water and supplying all or a part thereof to the centrifuging step. . 3. The oil-in-water emulsion comprises (a)
Mineral oil having a viscosity of 80 cSt or less at 40 ° C .: 50 to 9
6.4 parts by mass, (b) fatty acid, oil and fat, and at least one compound selected from the group consisting of monoesters of fatty acids and alcohols: 30 to 3 parts by mass, (c) carbon number of 4 to 18 At least one kind of phosphoric acid ester or phosphorous acid ester having an alkyl group or an alkenyl group of: 10 to 0.5 parts by mass, (d) the following general formula (1): (In the formula, R ¹ is a hydrogen atom or a methyl group, and R ² and R
³ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, m is 0 or 1, and n is an integer of 1 to 3), and (meth) acrylamide and / Alternatively, a copolymer of (meth) acrylic acid salt and a polymer compound having an average molecular weight in the range of 10,000 to 1,000,000, represented by the following general formula (2) R ⁴ COOH (2) ( In the formula, R ⁴ is an alkyl group having 1 to 5 carbon atoms or a hydroxyalkyl group, or an alkyl moiety having 1 to 5 carbon atoms.
5. A method for rolling a metal plate according to claim 1 or 2, which comprises a salt with an organic acid represented by the carboxyalkyl group of 5 or a carboxyl group: 10 to 0.1 part by mass. 4. The method for rolling a metal plate according to claim 1, wherein the centrifugation is performed at 100 to 3000 G. 5. The method for rolling a metal plate according to claim 1, which is applied to finish rolling of a metal plate. 6. The method for rolling a metal plate according to claim 1, which is applied to hot rolling of an Al plate or an Al alloy plate.