JPH06322385A - Cold rolling oil - Google Patents

Abstract

PURPOSE:To obtain a cold rolling oil not causing surface defects even in use of rolling of extremely thin steel plate, comprising a trimethylolpropane ester of a mixed fatty acid containing lauric acid and a monoenecarboxylic acid in a ratio satisfying specific correlation. CONSTITUTION:The objective cold rolling oil comprises >=70wt.% of a triester of a mixed fatty acid and a polyhydric alcohol (e.g. trimethylolpropane), composed of (A) lauric acid and (B) a 14-18C monoenecarboxylic acid (e.g. myristoleic acid) or the component A, the component B and (C) a 14-18C straight-chain saturated fatty acid (myristic acid) in the ratio of the component A and B of 1:(0.12-1.5) by weight and the wt.% of the component C in the whole mixed fatty acids of 0-25 or in the ratio of the component A and B of 1:(1.5-4.0) by weight and the wt.% (x) the component C in the whole mixed fatty acids in the range of the formula [(y) is weight ratio of the component B based on the component A (y=B/A)] and reduces bad de-fatting and contamination of mill housing.

Description

Detailed Description of the Invention

[0001]

This invention relates to cold rolling oils.

[0002]

2. Description of the Related Art In recent years, good lubricity is required as the speed of cold rolling mills increases. Especially the tin gauge (eg.
4mm or less) cold rolling for ultra-thin steel has a large reduction ratio,
In addition, since it is necessary to roll at a high speed of 1500 m / min or more in order to improve productivity, the cold rolling oil is required to have good lubricity. Therefore, conventionally, natural fats and oils having a relatively high pour point, such as beef tallow, have been used as rolling oil bases. However, when such a cold rolling oil is used, the stain in the mill housing is severe due to the high pour point, and many quality defects occur on the surface of the rolled steel sheet,
The work environment has also become a problem. On the other hand, since a low pour point is used, when a low pour point oil or fat is used as a rolling oil base, the thermal oxidation stability is low, so that oil burning or poor degreasing occurs.

In recent years, in order to improve the problems of the cold rolling oil using the natural fat and oil as described above, it has been attempted to use the cold rolling oil using the synthetic ester, and some of them have already been practically used. There is. However, synthetic esterification of cold rolling oil for cold rolling for ultra-thin steel such as tin gauge, which has particularly severe rolling conditions, has not yet been put to practical use.

JP-B-48-27867 discloses a cold rolling oil using a partial ester of neopentyl polyol and fatty acid. By using a partial ester, a cold rolling oil having a viscosity suitable for cold rolling for ultra-thin steel and a low pour point can be obtained with an ester of a saturated fatty acid having 8 to 10 carbon atoms, but the viscosity index is low. However, sufficient rolling characteristics cannot be obtained.

Japanese Unexamined Patent Publication (Kokai) No. 55-145638 discloses a complex ester synthesized from three components of a polyhydric alcohol, diglycolic acid and a monobasic acid, but it has a high viscosity and a low viscosity index, and therefore is accelerated. At times, the oil film thickness becomes excessively large and slippage is likely to occur, and at the same time, oil and fat breakage occurs in the high-speed rolling region, and heat scratches easily occur, which is not suitable for cold rolling oil for ultra-thin steel sheets.

[0006]

The present invention is a cold rolling oil,
Especially in the high-speed cold rolling of ultra-thin steel sheets such as tin gauge, fluctuations in the thickness due to chattering, surface defects due to heat scratches, problems in the next process such as poor degreasing, dirt in the mill housing and the surface of indentation flaws resulting from this. Provided is a cold rolling oil which can be rolled without causing defects.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have found that cold rolling oils based on mixed fatty acid esters described below as base oils have low pour points necessary for keeping the mill housing clean and rolling for ultra-thin steel sheets. The present invention has been completed by finding that they simultaneously satisfy good degreasing properties, a high viscosity index, and an appropriate viscosity required as an oil.

The present invention comprises (a) lauric acid and (b) 14 to 14 carbon atoms.
18 monoenecarboxylic acids, or (a), (b) and (c)
Cold tinplate comprising 70% by weight or more of an ester of a mixed fatty acid represented by the following (i) or (ii) and a polyhydric alcohol, which is composed of a linear saturated fatty acid having 14 to 18 carbon atoms. Regarding rolling oil. (i) The weight ratio of a and b is 1: 0.12 to 1.5, and the weight ratio of c in the total mixed fatty acid is 0 to 25. (ii) The weight ratio of a and b is 1: A mixed fatty acid in which the weight% (x) of c in the total mixed fatty acid in the range of 1.5 to 4.0 is within the range of the following inequality.

[0009]

[Equation 2]

The ester used as the base oil of the rolling oil of the present invention is a complete ester of the above fatty acid and a polyhydric alcohol, particularly trimethylolpropane. At least 80% by weight, more preferably 90% by weight or more of the polyhydric alcohol component is trimethylolpropane. A partial ester having one or more hydroxyl groups in the ester molecule has a low viscosity index and a high viscosity, and is not suitable as a base oil for cold rolling oil for ultra-thin steel sheets such as tin steel sheet. Esters of diols such as neopentyl glycol have low viscosity and cannot secure a sufficient oil film at high temperatures. Also, polyglycerin such as glycerin and diglycerin, pentaerythritol,
The ester of dipentaerythritol has a higher pour point than the ester of trimethylol propane, and it is not possible to simultaneously satisfy the pour point condition of rolling oil for keeping the mill housing clean and the degreasing condition after rolling. However, the esters of the above polyhydric alcohols other than trimethylolpropane may be partially mixed and used. Also in this case, the effect of the present invention is impaired if a large amount is mixed, so the content should be 20% by weight or less based on the total ester.

The fatty acids constituting the ester are lauric acid,
A monoenecarboxylic acid having 14 to 18 carbon atoms such as myristoleic acid, palmitoleic acid, oleic acid and the like and 1 carbon atom
4-18 linear saturated fatty acids, for example, mixed fatty acids such as myristic acid, palmitic acid, stearic acid, etc., but the ratio must be within the following range (i) or (ii). (i) The weight ratio of lauric acid to the monoenecarboxylic acid having 14 to 18 carbon atoms is 1: 0.12 to 1.5, and the straight chain saturated fatty acid having 14 to 18 carbon atoms accounts for 0 to 25% by weight of the total fatty acids. Is a mixed fatty acid.

When the weight ratio of the monoenecarboxylic acid having 14 to 18 carbon atoms to lauric acid is 0.12 or less, the pour point exceeds 0 ° C. A lower pour point is better for maintaining mill cleanliness, but the pour point needs to be 0 ° C. or lower in consideration of the winter season when the mill atmosphere temperature is the lowest. Further, if the weight ratio of the monoenecarboxylic acid having 14 to 18 carbon atoms is 1.5 or more, the degreasing rate of 90% or more cannot be secured by the degreasing method described in the examples depending on the amount of the linear saturated fatty acid.

If the weight percentage of the straight chain saturated fatty acid in the total fatty acids exceeds 25, the pour point exceeds 0 ° C., which is not suitable. (ii) The weight ratio of lauric acid to the monoenecarboxylic acid having 14 to 18 carbon atoms is 1: 1.5 to 4.0, and the weight% of the linear saturated fatty acid having 14 to 18 carbon atoms in the total fatty acid (x) A mixed fatty acid wherein is within the following inequality:

[0014]

[Equation 3] When the weight ratio of the monocarboxylic acid having 14 to 18 carbon atoms to lauric acid exceeds 4.0, both the conditions of pour point and degreasing property are simultaneously satisfied regardless of the amount of the linear saturated fatty acid having 14 to 18 carbon atoms. I can't.

The amount of linear saturated fatty acids having 14 to 18 carbon atoms in the total fatty acids is (0.4-0.6 / y) × 100% by weight.
In the following cases, the degreasing rate of 90% or more cannot be secured, and in the case of 25% by weight or more, the pour point cannot be 0 ° C. or less.

When a straight chain saturated fatty acid having 8 to 10 carbon atoms such as capric acid, caprylic acid, or pelargonic acid is used instead of lauric acid, the odor becomes strong, which is not preferable. Even when mixed with lauric acid, it should be 10% by weight or less, preferably 5% by weight or less.

Since diene carboxylic acids such as linoleic acid and triene carboxylic acids such as linolenic acid remarkably deteriorate the degreasing property, the diene carboxylic acid is contained in the monoene carboxylic acid in an amount of 10% by weight or less, preferably 5% by weight or less. It is better to use as little carboxylic acid as possible.

Branched fatty acids such as isostearic acid have the same effect of lowering the pour point as monoenecarboxylic acid, but are not preferred because they lower the viscosity index. Even when used in combination with a monoenecarboxylic acid, the amount is 10% by weight or less, preferably 5% by weight or less.

The ester used in the present invention is essentially a complete ester. When trimethylolpropane is used as the polyhydric alcohol, the molar ratio with the mixed fatty acid is preferably 1: 2.6 to 3.0. When the ratio of the mixed fatty acid is 2.6 or less, the viscosity index decreases.

The rolling oil of the present invention may be used as a mixture of two or more kinds of the above esters. The dimer acid used in the present invention is a dibasic acid having 21 to 36 carbon atoms, such as a dimer of oleic acid, and is added in an amount of 1 to 3% by weight based on the rolling oil. If the amount of dimer acid added is less than 1% by weight, heat scratches cannot be prevented during high-speed rolling, and if it is 3% by weight or more, wear of work rolls becomes a problem.

Examples of other components which may be added to the rolling oil of the present invention include fatty acids, extreme pressure additives, particularly phosphate ester type, emulsifiers, antioxidants and the like. The rolling oil of the present invention is used by diluting it with water to 0.5 to 20% by volume.

The present invention will be described below with reference to examples and comparative examples.

【Example】

Example 1 Table 1 shows the charging ratio of the fatty acid and alcohol of the synthetic ester used in the rolling oil of the present invention and the physical properties of the rolling oil prepared based on the following rolling oil formulation using the synthetic ester.

Trimethylolpropane 1 as a mixed fatty acid ester of trimethylolpropane used in Example No. 1
5.86 parts by weight, 48.80 parts by weight of monoenecarboxylic acid having 14 to 18 carbon atoms, and 11.78 parts by weight of linear saturated fatty acid having 14 to 18 carbon atoms were obtained by reacting at 260 ° C. for 8 hours under a nitrogen stream. Acid number 5 ester. Examples No. 2 to No.
7 and the esters of Comparative Examples No. 9 to No. 17 were obtained in the same manner.

[0024]

[Table 1]

Rolling oil formulation Synthetic ester 88.9 (%) Mixed fatty acid 3.0 Dimer acid 2.0 Organic acid phosphoric acid ester Aromatic amine salt 2.0 Nonionic surfactant 2.9 Amine antioxidant 1 0.0 Anti-bacterial agent 0.2

Example 2 A degreasing test was conducted on the rolling oils in Table 1 under the following conditions. Degreasing conditions Test steel sheet: Using a rolling machine with a work roll diameter of 100 mm and a roll peripheral speed of 12 mpm, a SPCC cold steel sheet with a plate thickness of 0.8 mm was sprayed with a 4% emulsion of each rolling oil, and the rolling reduction was 2
Roll at 0%. Further stacking this steel plate, 130 ℃
It was installed in a constant temperature bath for 12 hours. Electrolytic solution: An electrolytic degreasing additive formula 613H-X 0.3% was added to a 2% aqueous sodium hydroxide solution. Temperature: 80 ° C. Current density: 10 A / dm ² Electrolysis time: 3 seconds The test results are shown in Table 2.

[0027]

[Table 2]

Example 3 Inventive product No. 2 and comparative products No. 8 and No. 12 in Table 1 were subjected to tandem high speed rolling of tin plate under the following conditions. Rolling mill: 5 stand tandem rolling mill with recirculation coolant system Rolling speed: 2100 mpm Max Work roll diameter: 576 mm (1 to 4 stands) 425 mm (5 stands) Rolled steel column: C: 0.03 to 0.06% , Si: 0 to 0.
03% Mn: 0.2 to 0.3%, P: 0 to 0.015% S: 0.01 to 0.025%, N: 0.0025 to 0.006
% Sol-Al: 0.02 to 0.06%, Cr: 0 to 0.06% Original plate thickness: 2 mm Finished plate thickness: 0.2 mm Reduction ratio: 1 → 2 → 3 → 4 → 5 37.3% 42.6% 38.6% 33.6% 32.0% Rolling oil concentration: 4% Rolling oil temperature: 60 ° C

[0029]

[Table 3]

[0030]

EFFECTS OF THE INVENTION By using the rolling oil of the present invention, it is possible to obtain an ultra-thin steel sheet free from fluctuations in sheet thickness due to chattering and surface defects due to heat scratch, particularly a steel sheet having excellent quality as a tin plate. At that time, the adhesion of dirt to the housing and the poor degreasing are significantly reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiyuki Morita 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) In-house 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Steel Tube Co., Ltd. (72) Inventor Toshikazu Ikeda 2-3 1-3 Shibukawa-cho, Yao-shi, Osaka Japan Quaker Chemical Co., Ltd. (72) Hiroshi Hayashi 2-3 1-3 Shibukawa-cho, Yao-shi, Osaka No. Japan Quaker Chemical Co., Ltd.

Claims (7)

[Claims] 1. A composition comprising (a) lauric acid and (b) a monoenecarboxylic acid having 14 to 18 carbon atoms, or (a), (b) and (c) a linear saturated fatty acid having 14 to 18 carbon atoms. A cold rolling oil containing at least 70% by weight of a triester of a mixed fatty acid and a polyhydric alcohol represented by the following (i) or (ii). (i) The weight ratio of a and b is 1: 0.12 to 1.5, and the weight ratio of c in the total mixed fatty acid is 0 to 25. (ii) The weight ratio of a and b is 1: A mixed fatty acid in which the weight% (x) of c in the total mixed fatty acid in the range of 1.5 to 4.0 is within the range of the following inequality. [Equation 1] 2. The cold rolling oil according to claim 1, wherein the polyhydric alcohol is trimethylolpropane. 3. 10% by weight or less of lauric acid has 8 carbon atoms
The cold rolling oil according to claim 1, which is substituted with a linear saturated fatty acid of 10 to 10. 4. The cold rolling oil according to claim 1, wherein 10% by weight or less of the monoenecarboxylic acid having 14 to 18 carbon atoms is replaced with a dienecarboxylic acid having 16 to 18 carbon atoms. 5. The cold rolling oil according to claim 1, wherein 10% by weight or less of the monoenecarboxylic acid having 14 to 18 carbon atoms is replaced with isostearic acid. 6. The cold rolling oil according to claim 2, wherein the molar ratio of trimethylolpropane to the mixed fatty acid is 1: 2.6 to 3.0. 7. The cold rolling oil according to claim 1, which contains 1 to 3% by weight of dimer acid.