JP3038444B2 - Cold rolling oil for stainless steel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rolling oil used for cold rolling of stainless steel. More specifically, the present invention relates to a cold rolling oil for stainless steel containing glycerin triester and having excellent extreme pressure lubrication characteristics and surface gloss.

[Related Art] Cold-rolling oil for stainless steel is mainly used to remove processing heat and reduce friction between a rolling roll and a stainless steel plate by supplying the rolled portion to stainless steel.

In general, when cold rolling of stainless steel is performed under high pressure to improve production efficiency, linear surface damage (seizure, heat scratch) parallel to the rolling direction is likely to occur, and high-speed rolling is performed. In such a case, it is known that a minute concave surface defect (oil bit) is generated on the stainless steel surface, so that the surface glossiness of the product is reduced.

In view of the relationship with the viscosity of the rolling oil, high-viscosity rolling oil enables rolling under high pressure, but the surface gloss of the product decreases, while the low-viscosity rolling oil improves the surface gloss of the product However, there is a problem in that rolling under high pressure generates heat scratches and is not suitable for rolling under high pressure.

Therefore, for the rolling oil used for cold rolling of stainless steel under high pressure and high speed rotation, products that reduce the friction between the rolling roll and the stainless steel plate, do not cause seizure, and have excellent surface gloss Obtained performance is required.

A conventionally used cold rolling oil for stainless steel is a composition containing at least 10% by weight of an ester of a fatty acid having 10 to 22 carbon atoms and an alcohol having 1 to 7 carbon atoms (JP-A-56-161496). Publication), a composition containing a saturated aliphatic monohydric alcohol such as lauryl alcohol and palmityl alcohol, or a saturated fatty acid such as lauric acid and stearic acid, or a saturated aliphatic monoester such as methyl laurate and butyl stearate. (Japanese Patent Publication No. 56-35624), a composition containing an aromatic dibasic acid, a dibasic acid ester of a linear saturated aliphatic dibasic acid and an aliphatic monohydric alcohol (Japanese Patent Publication No. 57-37639) ) Are known.

In addition, these rolling oils are used for cold rolling under high pressure and high-speed rotation in addition to a base oil having a comparative viscosity of high viscosity, and thus, the product lacks surface gloss. In order to solve such problems of the prior art, it has been reported that trimellitic acid ester can be used as a cold rolling oil of stainless steel which can be rolled under high pressure and high speed and further improves the surface gloss of products. (Japanese Unexamined Patent Publication No.
182396).

[Problems to be solved by the invention] However, due to the rapid progress of rolling technology in recent years,
As the rolling under high pressure and high speed, the number of rolling passes is reduced, and the specification of the rolled product is increased, the lubricating conditions of the rolling oil are becoming increasingly severe. Further, in the finish rolling of stainless steel, improvement in surface gloss of products is particularly required.

In view of this situation, the rolling oils conventionally known as described above have a low pressure-resistant load and are not yet sufficient as rolling oils under high pressure and high speed, and the surface gloss of products is not sufficient. .

Therefore, there is a need in the art for the development of a cold rolling oil for stainless steel that has a high pressure resistance, enables high-pressure, high-speed rolling, and has better surface gloss of the product.

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, when a rolling oil containing glycerin triester is used, the pressure resistance load is high and the extreme pressure lubrication property is high. The present inventors have found that excellent results and excellent surface gloss can be obtained, and have completed the present invention.

That is, the gist of the present invention is represented by the following general formula [In the formula, R ¹ , R ² and R ³ represent a linear or branched alkyl group having 7 to 11 carbon atoms. ] A cold rolling oil for stainless steel containing 5 to 100% by weight of a glycerin triester of a saturated fatty acid (excluding a cold rolling oil containing an aromatic amine salt of an organic acid phosphate) represented by the following formula: .

In the general formula, R ¹ , R ² and R ^{3 each} represent a linear or branched alkyl group having 7 to 11 carbon atoms. When the number of carbon atoms is 6 or less, the seizure resistance is poor. It is not preferable because glossiness is deteriorated. R ¹ , R ² and R ³ may all be the same or different, but examples of all the same are those obtained by esterifying 1 mol of glycerin and 3 mol of caprylic acid. Examples of different ones are glycerin 1mol, caprylic acid 2mol, capric acid 1m
Examples thereof include those obtained by esterifying ol.

The glycerin triester in the present invention is a triester of glycerin and a saturated fatty acid, and diesters and monoesters are not preferable because of poor seizure resistance.

Examples of the saturated fatty acids include linear saturated fatty acids such as caprylic acid, capric acid, and lauric acid, 2-ethylhexanoic acid,
Examples include branched saturated fatty acids such as 3,5,5-trimethylhexanoic acid. The glycerin triester in the present invention can be easily synthesized using glycerin and these saturated fatty acids by a method known per se.

The glycerin triester in the present invention may be a single kind of glycerin triester, and R ¹ , R ² and R ³ may be all the same or different as described above, but R ¹ , R ² and R ³ which is appropriately mixed glycerol triester are different from all the ingredients same glycerol triesters, R ^1, R ^2, and those wherein R ³ and completely mixed appropriately same two or more glycerol esters, or R ¹ , R ² and R
Any of those obtained by appropriately mixing two or more glycerin triesters having different ³ may be used.

The cold-rolling oil of the present invention is used for cold-rolling stainless steel. Here, stainless steel is a steel that forms a passive body and retains its stainless steel, and contains chromium as a main component. Say. For example, as austenitic, SUS304
(18Cr-8Ni), SUS301 (17Cr-6Ni), SUS305 (18Cr-
12Ni), SUS316 (18Cr-12Ni-2.5Mo), ferrite-based SUS410L (1owC-12Cr), SUS430 (17Cr), SUS
430LX (17Cr-Ti), SUS444 (1owC-18Cr-2Mo-Ti),
SUS410 (12Cr), SUS420J2 as martensite
(0.35C-13Cr), SUS440A (0.7C-17Cr) and the like.

The cold-rolled oil of the present invention contains the above-mentioned glycerin triester in an amount of 5 to 100% by weight, and is prepared by blending it with one or more kinds selected from oils and fats, fatty acid esters and mineral oils as necessary. You. For example, fats and oils include natural fats and oils such as lard, beef tallow, coconut oil, and palm oil. Examples of the fatty acid ester include a fatty acid obtained by decomposing natural fats and oils, and an ester obtained by reacting a synthetic fatty acid obtained by an oxo method or the like with an alcohol. Fatty acids used as a raw material of this ester include fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, hydroxystearic acid, ricinoleic acid, behenic acid, dicarboxylic acids such as glutaric acid and adipic acid, and trimet Examples include tricarboxylic acids such as acids, and polymerized fatty acids such as dimer acids and trimer acids. In addition, as the alcohols used as the raw material of this ester,
Methanol, ethanol, propanol, butanol,
Hexanol, monoethyl alcohol, octyl alcohol, lauryl alcohol, tridecanol, myristyl alcohol, palmityl alcohol, stearyl alcohol, monohydric alcohols such as oleyl alcohol, glycols, polyhydric alcohols such as trimethylolpropane, pentaerythritol, etc. Is exemplified. Examples of the mineral oil include known mineral oils such as spindle oil, machine oil, motor oil, and neutral oil.

In the cold rolling oil of the present invention, various additives as necessary,
For example, conventionally used oiliness improvers, extreme pressure agents, antioxidants, preservatives, rust preventives, emulsifiers, dispersants and the like can be used in combination.

The oiliness improver may be any of those conventionally used in cold rolling oils, such as lauric acid, myristic acid, palmitic acid, stearic acid, fatty acids such as oleic acid, dimer acid, and trimer acid. Polymerized fatty acids and alcohols such as octyl alcohol, lauryl alcohol, tridecanol, myristyl alcohol, stearyl alcohol, and oleyl alcohol are used.

As the extreme pressure agent, an organic phosphorus compound, a sulfur compound, a chlorine compound, an iodine compound and the like are generally used.

As the antioxidant, a chain-stopping type, for example, 2,
6-di-t-butyl-methylphenol, phenyl-β
Peroxide-decomposable types such as naphthylamine and the like, for example, dithiocarbonate, monosulfide, metal dialkyldithiophosphate, selenide and the like are used.

Further, as a preservative, 2-bromo-2-nitropropane 1,3 diol and the like are used, and as a rust preventive, fatty acid amines, organic phosphorous acid and phosphoric acid ester, organic sulfonate and the like are used.

Examples of the emulsifier include anionic surfactants such as fatty acid salts and alkyl sulfate salts, cationic surfactants such as alkylamine salts and quaternary ammonium salts, and nonionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene sorbitan fatty acid esters. A surfactant or the like is used, and a polymer dispersant is usually used as the dispersant.

The cold-rolled oil of the present invention thus prepared has a pressure resistance against stainless steel of 3.0 to 3.5 kg / cm ² , has no seizure, and has a surface gloss (20 mm), as described in Examples below. Gs) has a performance of about 900, and is a rolling oil with excellent surface luster as well as extreme pressure lubrication.

As a method of using the cold-rolling oil of the present invention, the cold-rolling oil is supplied to the rolled portion of stainless steel in the same manner as the conventional method of using the cold-rolling oil. It is preferably used as a 0.5% to 20% emulsion using the agent.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, Comparative Examples, and Test Examples, but the present invention is not limited to these Examples.

Example 1 85% by weight of glycerin triester of caprylic acid at 40 ° C.
Blended in 10% by weight of paraffinic mineral oil (mineral oil B) having a kinematic viscosity of 50 cSt, and polyoxyethylene nonylphenyl ether (ethylene oxide addition mole =
5) By adding 5% by weight, the kinematic viscosity at 40 ° C.
A 15 cSt rolling oil 1 was prepared.

Examples 2 to 5 As in Example 1, rolling oils 2 to 2 were mixed at the compounding ratios shown in Table 1.
5 was prepared. The mineral oil A has a kinematic viscosity at 40 ° C.
4.5 cSt paraffinic mineral oil was used.

Comparative Examples 1 to 9 wherein R ¹ , R ² and R ^{3 in} the general formula have 4 or less carbon atoms,
Rolling oils were prepared in the same manner as in Example 1 at a compounding ratio shown in Table 1 for two or more, those containing no glycerin diester, glycerin monoester, and glycerin ester, and used as comparative rolling oils 1 to 9.

Test Example Rolling oils 1 to 5 obtained in Examples 1 to 5, Comparative Example 1
Various performances of the comparative rolling oils 1 to 9 obtained by the methods described below were tested by the following methods.

Viscosity measurement The viscosity was measured at 40 ° C. using a Canon Fenske viscometer according to JIS-K-2283.

Method of Supplying Rolling Processing Oil The rolling processing oil shown in Table 1 was put into water so that the oil concentration became 5%, and the emulsion temperature was kept at 55 ° C while stirring with a homomixer. This emulsion was supplied to lubricated parts of a soda four-ball testing machine, a rolling mill and the like by a pump.

Seizure resistance evaluation test To examine seizure resistance to stainless steel, 1.
Stainless steel was used as the test material in both the Soda four-ball friction test and the rolling test.

1. Soda Four-Ball Friction Test Apparatus: Soda Four-Ball Friction Tester Test material: Upper ball, SUS304 ball Lower ball, SUJ ball Measurement method of pressure resistance: The pressure resistance at 100 rpm was determined. (Shock road method) 2. Rolling test Rolling mill specifications: Passive mill Rolling conditions: Rolling method Coil rolling Roll diameter 50mmφ Barrel length 30mm Roll roughness Rmax 0.1μm Roll material SUJ-2 Hardness Hs = 95 Rolling speed: plate speed 120m / min Roll peripheral speed 80m / min Reduction rate: 10% Specimen: Material SUS430-2B Dimension 0.4mm x 15mm x Coil Rolling oil coolant: Flow rate 1.0 / min Spray pressure: 1kg / cm ² Evaluation method in rolling test: Rolling Judgment was made based on the degree of seizure scratches on the surface of the steel sheet later.

Gloss evaluation test Rolling mill specifications: Two-high rolling mill Rolling conditions: Rolling method Strip rolling Roll diameter 200mmφ Barrel length 200mm Roll roughness Rmax 0.1μm Roll material SUJ-2 Hardness Hs = 95 Rolling speed: Roll peripheral speed 100m / min Rate: 65% (4 passes) Specimen: Material SUS430-2B Dimensions 1.0mm x 50mm x 800mm Rolling oil coolant: Flow rate 1.0 / min Spray pressure: 1kg / cm ² Evaluation method in rolling test: Surface of steel sheet after rolling Judge the gloss.

Gloss measurement method: Measure the 20 degree specular gloss by the method according to JIS-Z-8741. 800 SUS430-2B on the market, SUS430
-BA shows a value of about 1000, and the larger the value, the higher the glossiness.

Table 1 shows the results of these tests.
In the case of No. 5, the withstand pressure load was 3.0 to 3.5 kg / cm ² , the surface properties were no seizure (（) in all cases, and the surface gloss was about 90.
It showed excellent performance of 0 (20 ゜ Gs).

On the other hand, the comparative rolling oil 1 using glycerin triester of butyric acid was inferior in pressure resistance load and also suffered seizure, and the comparative rolling oils 2 and 3 using glycerin triester of palmitic acid and stearic acid had a lower surface. The results showed that the glossiness was poor, and that the comparative rolling oils 4 to 7 using diesters and monoesters of glycerin had poor pressure resistance load and poor surface properties.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C10M 105/38 C10N 40:24

Claims (1)

(57) [Claims] 1. The following general formula: [In the formula, R ¹ , R ² and R ³ represent a linear or branched alkyl group having 7 to 11 carbon atoms. A cold rolling oil for stainless steel containing 5 to 100% by weight of a glycerin triester of a saturated fatty acid represented by the following formula (excluding a cold rolling oil containing an aromatic amine salt of an organic acid phosphate).