JPH0672229B2 - Cold rolling oil for steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a highly lubricating generated rolling oil having an excellent friction coefficient and pressure resistance under high pressure and high speed rotation, and electrolytic cleaning or Without reducing other cleaning processes
Even if it is annealed as it is, no stain is generated on the surface. That is, the present invention relates to a cold rolling oil for steel sheets having excellent mill cleanliness.

(Prior art) Cold rolling oils used during cold rolling of thin steel sheets are based on animal and vegetable oils (beef tallow, lard, palm oil, coconut oil, etc.) and mineral oils as base oils. They are roughly divided into those that do. In recent years, with the improvement of production efficiency such as energy saving and process saving, high pressure rate rolling, high speed rolling, and Micklean rolling have been aimed. Rolling oil using animal and vegetable oils and fats as a base oil is suitable for high-load and high-speed rolling.However, when the cold-rolled steel sheet is annealed as it is without degreasing the adhering oil content, the steel sheet surface in the annealing process It causes dirt. That is, fats and oils produced by triglyceride have excellent lubricity, but are unsuitable for mill cleanliness (direct annealing).

On the other hand, when a rolling oil using a mineral oil as a base oil is subjected to cold rolling of a steel sheet, it is excellent in mill cleanliness without causing surface stains even when directly annealed a cold thin steel sheet, Inferior to high-pressure reduction rolling and high-speed rolling.

In general, rolling oils based on mineral oils are used in order to improve rolling lubricity, animal and vegetable fats and oils and fatty acids (capric acid, lauric acid, myristic acid, stearic acid, oleic acid, linolenic acid, etc.) or oil chemistry '73. Improving the oiliness of esters (monoesters such as trimethylolpropane, pentaerythritol, 2-ethylhexyl alcohol, etc., synthetic esters such as diesters and polyol esters) listed in the November issue, p.695-706 The agents are used by adding them, and the amount of these agents added is adjusted to the narrowest range necessary to maintain mill cleanliness. As described above, various studies have been made on cold rolling oils that simultaneously satisfy high lubricity and mill cleanliness (for example, JP-A-56-135600 and JP-A-59-8049).
The current situation is that it has not reached sufficient performance.

(Problems to be Solved by the Invention) The present invention is a cold rolling oil for thin steel sheets, which contributes to the improvement of production efficiency such as energy saving and process saving, against heat and mechanical shearing generated at high speed and high pressure. Stable, stable against chemical reactions such as oxidation, decomposition, polymerization, etc. In the annealing process, the residual salt of thermal decomposition of rolling oil is less likely to be generated and easily volatilized. It provides a cold rolling oil for a steel sheet having both.

[Means and Actions for Solving Problems] The present invention is a cold rolling oil for steel, which is mainly composed of a synthetic ester of sorbitol and a non-α-methyl branched fatty acid having 12 or more carbon atoms, and has high lubricity and It has high mill cleanliness and enables rolling of thin steel sheets and effective annealing without degreasing the steel sheets.

The synthetic ester referred to in the present invention is an ester compound which is molecularly designed and synthesized for such purpose.

In recent years, synthetic esters have been used as a rolling oil additive component or as a base oil, but few synthetic esters currently used for cold rolling oil have been synthesized for this purpose, and engine oil and hydraulic oil are used. In many cases, it is selected from existing synthetic esters used as hydraulic oils or other lubricants, and it is not a synthetic ester that can sufficiently satisfy both high lubricity and high mill cleanliness.

INDUSTRIAL APPLICABILITY The synthetic ester of the present invention is used for cold rolling oil, that is, has the characteristics of having high lubricity and high mill cleanliness, and has the following molecular design.

That is, the present invention relates to solibitol and non-α having 12 or more carbon atoms.
It is a cyclized product-containing esterification product with a branched methyl branched fatty acid, which is a cold rolling oil for a steel sheet containing the esterification product having two or more ester groups.

Furthermore, a cyclized product-containing esterification product of a mixed fatty acid and sorbitol in which 50 mol% or less of a non-α-methyl-branched fatty acid having 12 or more carbon atoms is replaced with a linear fatty acid having 12 or more carbon atoms, and two ester groups are included. It is a cold rolling oil for a steel sheet containing the above esterified product.

As the non-α-position methyl branched fatty acid having 12 or more carbon atoms shown here, those having a methyl group as a side chain on the carbon excluding the α-position, indotecanic acid, intridecanoic acid, isomyristic acid, isopalmitic acid, Isostearic acid, isoarachidic acid, isobehenic acid, isolignoceric acid, isocerotic acid, isomotantanic acid and the like can be used.

When a methyl-branched fatty acid having less than 12 carbon atoms is used, the degree of improvement in lubricity during cold rolling of a steel sheet is small. on the other hand,
Although the upper limit of the carbon number of methyl-branched fatty acid is not particularly limited,
Generally, a carbon number of 28 or less, which is industrially available, is preferable. As the non-α-methyl branched fatty acid having 12 or more carbon atoms, a typical methyl-branched fatty acid in lanolin fatty acid,
Alternatively, there is methyl-branched fatty acid obtained as a by-product when producing dimer acid from oleic acid or linoleic acid. These are generally represented by the general formula (1).

(However, m + n is an integer of 8 or more; m is an integer of 1 or more) The sorbitol used in the production of the synthetic ester of the present invention is dehydrated and condensed in the course of the reaction to be converted into sorbitan, sorbite, etc. as described below. It produces a complex composition to react.

("Synthetic surfactants" published by Sankyo Publishing, Hirotaka Horiguchi, p.32
9) Conventionally, sorbitan fatty acid ester known by the general name Span is widely used as a nonionic surfactant, but as the fatty acid, an ester with a natural linear fatty acid such as lauric acid, stearic acid and oleic acid is used. An esterified product with a saturated fatty acid (lauric acid, stearic acid, etc.) is a high melting wax-like solid and is not suitable for use as a rolling oil like the present invention. Esterification products with unsaturated fatty acids such as oleic acid are liquid at room temperature, but as a cold rolling oil, stability and direct annealability are poor. Further, the degree of improvement in lubricity when cold rolling a steel sheet is small.

The present invention converts the esterification product of sorbitol and a straight-chain fatty acid, which has been widely used as a conventional surfactant, to an esterification product of a non-α-position methyl branched fatty acid, that is, sorbitol is converted to a cyclized product such as sorbitan and sorbite. Change,
And by making them products of esterification with non-α-methyl-branched fatty acids, it becomes a low freezing point, a highly stable oil agent, and the degree of improvement of lubricity when rolling steel sheets is obviously increased, and direct annealing property is improved. Very well, I found a performance that was previously unthinkable.

The non-α-position methyl-branched fatty acid suitable for rolling lubrication of the present invention has 12 or more carbon atoms, and if the carbon-branching fatty acid has less than 12 carbon atoms, the target rolling lubrication property is inferior. It is difficult to obtain industrially. The upper limit of the carbon number is not particularly specified, but the industrially available range is preferably 28 or less.

Generally, it is desirable that the main component is isostearic acid, which is an isomerized methyl-branched fatty acid having 18 carbon atoms, which is obtained from oleochemical raw materials.

Among saturated branched fatty acids, those having a branched fatty acid in the α-position are mainly those having a relatively long-chain alkyl group, so they have good thermal stability and oxidation stability, but are expected to have rolling lubricity. The performance to do is not obtained. This is considered to be a difference in performance due to the branched structure of fatty acids.

In the esterification products according to the invention, diester, triester or tetraester compounds having two or more ester groups give very favorable results for rolling lubrication. On the other hand, in the case of mainly a monoester, it exhibits the properties of an emulsifier like the monoester of sorbitan and a straight-chain fatty acid known as an emulsifier, and it is not preferable because it causes an inconvenient result in rolling lubrication of a target steel sheet. Absent.

In addition, 50 mol% or less of the non-α-methyl branched fatty acid has 12 carbon atoms.
The cyclized product-containing esterification products substituted with the above linear fatty acids also show good rolling performance. In this case, the linear fatty acid having less than 12 carbon atoms does not improve the lubricity of the steel sheet during cold rolling. The upper limit of the carbon number is not particularly limited, but it is generally industrially inexpensive and available as
30 or less is preferred, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, ontacosanoic acid, palmitooleic acid, oleic acid, erucic acid, ricinoleic acid, hydroxystearic acid, Linoleic acid or the like can be used. In the synthesis, the non-α-methyl branched fatty acid and the linear fatty acid are mixed in a predetermined ratio and used.

The cyclized product-containing esterification product obtained by substituting the straight chain fatty acid in an amount of more than 50 mol% of the non-α-position methyl branched fatty acid has a high melting point and is not preferable for use as a rolling oil.

That is, the present invention, when cold-rolling a steel sheet, the lubricity of the cyclized product-containing esterification product of sorbitol and a non-α-methyl branched fatty acid having 12 or more carbon atoms has been conventionally used. It is clearly superior to fats and oils and generally known synthetic ester oils, and shows excellent performance in terms of bath stains, heat and oxidation stability during practical use, and also as a saturated fatty acid. Nevertheless, the obtained esterification product remains liquid at room temperature and is very convenient for use as a rolling oil.

Conventionally, it is structurally similar to sorbitan linear fatty acid ester, which is widely known as the general name Span and is widely used as an emulsifier.
It is characterized by the use of branched methyl fatty acid, and is an esterification product having two or more ester groups. It retains a liquid state at room temperature and has excellent lubricity, and favorable results for oxidation stability and annealing. Indicates. What is known as the general name Span is its role as an emulsifier to the last, the present invention is a chemical molecular design to be suitable for the purpose of cold rolling of steel sheet, Span
Is a completely different idea.

When using the synthetic ester of the present invention for rolling oil,
The synthetic ester alone can be used as a rolling oil. It can also be used in combination with other base oils such as mineral oils, animal and vegetable oils and fats or practical rolling oils, which are commonly used as additives, such as emulsifiers, fatty acids, antioxidants and corrosion inhibitors.

When the synthetic ester compound of the present invention is used in a mixture with other base oils, the effect is recognized by the addition of 1% by weight or more, but the content is 5% by weight or more, preferably 20% by weight or more. This stabilizes its characteristics.

The synthetic ester of the present invention can be produced by a usual method without a catalyst or in the presence of a catalyst, but the synthetic method is not particularly limited.

Hereinafter, specific synthesis examples and examples will be shown and described.

Synthesis example 4 equipped with stirrer, thermometer, nitrogen gas suction pipe, water separator
260 g of 70% sorbitol in a neck flask, Emerol 871 instearate manufactured by Emery Co. (neutralization value 175, iodine value 10,
Unsaponifiable matter 6%) 1120g was charged, sodium hydroxide 5g
Was added as a catalyst, xylene was used as a reflux solvent, 5% of the charged amount was added, and the mixture was stirred well and the mixture was reacted at 160 to 240 ° C. until a calculated amount of water was distilled. The required time was 7 hours. After completion of the reaction, xylene was distilled off under reduced pressure, and then decolorizing filtration was performed using activated clay to obtain a yellowish brown liquid. The yield was 1140 g and the acid value was 4.7.

(Synthesis example B) According to the method shown in the said synthesis example, the ester compound was synthesize | combined using sorbitol, methyl branched fatty acid, etc. as shown in Table 1.

(Example) Mineral oil and palm oil used as a base oil of a practical rolling oil,
The lubrication property and the annealing property of the rolling oil composition obtained when the emulsifiers, fatty acids, antioxidants and the like commonly used as additives and the synthetic ester which is the rolling oil of the present invention were blended were evaluated.

Emulsion rolling is a two-roll rolling mill, and rolling material (spcc) 1.2 x 20 x 200 mm is evaluated for rolling lubricity by measuring the rolling load at a rolling reduction of 40% at an oil concentration of 3% and a bath temperature of 50 ° C. did. Regarding the anneal property, several tens of steel sheets that had been rolled with the emulsion solution under test were stacked, then fixed with a narrow steel strip and annealed in a small annealing furnace.

The heating strip during annealing is heated to 500 ° C in a HNx gas (H ₂ : 5%) 120 ml / min atmosphere at a heating rate of 10 ° C / min.
It was kept at 00 ° C for 1 hour and then left to cool. After that, a cellophane tape was attached to the surface of the steel sheet, surface deposits were collected, and this was attached to white paper to visually determine the degree of stain, and the steel sheet surface cleanliness was evaluated.

The results are summarized in Table 2.

(Effects of the Invention) The cyclized product-containing esterification product of sorbitol of the present invention and a non-α-methyl branched fatty acid having 12 or more carbon atoms has a purpose of use as a cold rolling oil for steel sheet, and the necessary conditions therefor are satisfied. It is a molecule designed with consideration, and unlike the one that uses existing synthetic ester oil as cold rolling oil or as an additive, by improving the rolling lubricity of steel sheets,
Compared with the case of using conventional animal and vegetable oils and fats, it brings about the effect of energy saving and resource saving such as reduction of power cost, and also has excellent annealing property, so electrolytic degreasing can be omitted and the equipment cost can be reduced. It will be possible.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Goto 1-3, Chiwaka-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nisshin Oil Co., Ltd. (56) Reference JP-A-58-13698 (JP, A) Kai 57-162794 (JP, A) JP 53-140259 (JP, A) JP 52-97349 (JP, A)

Claims (4)

[Claims] 1. A cold rolled steel sheet containing a cyclized esterification product of sorbitol and a non-α-methyl branched fatty acid having 12 or more carbon atoms, the esterification product having two or more ester groups. oil. 2. 50% by mol of sorbitol, a non-α-methyl branched fatty acid having 12 or more carbon atoms and a linear fatty acid having 12 or more carbon atoms
A cold rolling oil for a steel sheet, which is a cyclized product-containing esterification product with a mixed fatty acid consisting of the following, and which contains the esterification product having two or more ester groups. 3. The cold rolling oil for steel sheet according to claim 1, wherein the methyl-branched fatty acid having 12 or more carbon atoms is isostearic acid. 4. The cold rolling oil for steel sheet according to claim (2), wherein the methyl-branched fatty acid having 12 or more carbon atoms is isostearic acid.