JPH0364559B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a rolling oil with high lubricity and high milklinity, that is, a cold rolling oil for steel with excellent lubricity and annealing properties. (Prior technology) Cold rolling oils used for thin steel sheets include those based on animal/vegetable oils (beef tallow, lard, soybean oil, rapeseed oil, palm oil, coconut oil, etc.) and those based on mineral oil. It is broadly classified into oil. In recent years, high-speed rolling, high-reduction rolling, and mill-clean rolling have been trending toward energy conservation and improved production efficiency. Rolling oils that use animal or vegetable oils as base oils are suitable for high-load, high-speed rolling, but if the oil deposits on a cold-rolled steel plate are directly annealed without degreasing, the steel plate will be damaged during the annealing process. Causes surface stains. In other words, although it has excellent lubricity, it is unsuitable for mill cleanliness. On the other hand, when a rolling oil with mineral oil as the base oil is used for cold rolling of a steel plate, surface staining does not occur even when the cold thin steel plate is directly annealed, and the mill cleanliness is excellent. However, it lacks high load and high speed rolling properties. Generally, rolling oils based on mineral oils are made using animal/vegetable oils, fatty acids (caprylic acid, lauric acid, myristic acid, stearic acid, oleic acid, linolenic acid, etc.) or oil chemistry '73 to improve rolling lubricity. , November issue, p.695-706 (synthetic esters such as monoesters, diesters, polyol esters, etc. whose alcohol component is trimethylolpropane, pentaerythritol, 2-ethylhexyl alcohol, etc.)
These oiliness improvers are added, but the amount of these additives is adjusted within a narrow range to the minimum necessary to maintain mill cleanliness. As mentioned above, various studies have been conducted on cold rolling oils that can simultaneously satisfy high lubricity and high mill cleanliness (for example, JP-A No. 56-135600, JP-A No. 59-Sho.
80498) Currently, sufficient performance has not been achieved. (Problems to be solved by the invention) The present invention is a cold rolling oil for steel that contributes to improving production efficiency through energy saving and process saving, and is stable against heat and mechanical shear generated under high speed and high pressure. It is also stable against chemical reactions such as oxidation, decomposition, and polymerization. In addition, the rolling oil is easily volatilized during the annealing process without producing thermal decomposition residues, and has both surface cleanliness (mill cleanliness) and high lubricity of the steel sheet. (Means for Solving the Problems) The present invention is a steel cold rolling oil containing synthetic ester as a main component, which has high lubricity and high mill cleanliness, and is useful for rolling thin steel plates and degreasing steel plates. This makes it possible to effectively perform annealing without any problems. (Function) The synthetic ester referred to in the present invention has been molecularly designed and synthesized for this purpose. In recent years, synthetic esters have been used as rolling oil additives or as base oils, but few of the synthetic esters used in cold rolling oils have been synthesized for this purpose, and are used in engine oils, hydraulic oils, In many cases, it is selected from existing synthetic esters used as other lubricants, and it is not a synthetic ester that can fully satisfy both high lubricity and high mill cleanliness. The synthetic ester of the present invention is used for cold rolling oil.
That is, it has the characteristics of both high lubricity and high mill cleanliness, and has the following molecular design. General formula RCOO-(R'-O)n-R''...(1) Where, R: Alkyl group having 7 or more carbon atoms R'; Alkyl group R'': Alkyl group n = Fatty acid represented by an integer from 1 to 5 and a glycol ether, provided that one or more of R, R' or R'' is necessarily a branched alkyl group. ) Examples of R in the formula include straight chain fatty acids octyl acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, montanic acid, and side chain fatty acids isooctyl. acid, isodecanoic acid, isolauric acid, isomyristic acid, isopalmitic acid, isostearic acid, isoarachidic acid, or is composed of fatty acid residues containing a mixture of two or more of them.In addition, R' is ethyl, propyl, isopropyl, butyl, It is an alkyl group such as an isobutyl group. As R'', methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl group, etc. are selected. Glycol ethers used in the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethyl glycol monomethyl ether, and diethylene glycol monopropyl ether. Ethyl ether, diethylene glycol monoisopropyl ether, diethyl glycol monobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, ethylene glycol monohexyl ether,
Diethylene glycol monohexyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monopropyl ether, etc. can be used. In addition, in the present invention, the carbon number of R in general formula (1) is 7.
This is because an ester compound having less than 7 carbon atoms improves the lubricity to a lesser extent when cold rolling a steel plate. On the other hand, the upper limit of the number of carbon atoms in R in the general formula is not regulated, but it is generally preferable that the number of carbon atoms is 29 or less as it can be obtained industrially at low cost. In addition, the general formula RCOO-(R'-O)n-
The reason why n in R'' is an integer from 1 to 5 is because when n is 6 or more, the rolling lubricity shows good results due to the increase in molecular weight, but it has a negative effect on annealing properties. In order to create a mill-clean rolling oil that satisfies both properties and annealing properties, n=1.
-5 range. In the present invention, the reason why any one or more of R, R' or R'' is necessarily a branched alkyl group is for the following reason. Namely, among the synthetic esters, the present substances A, B, Samples A′, B′, which have the same structure as C and consist only of linear alkyl groups
Table 1 shows a comparison of the physical properties, oxidation stability, and thermal stability of C'. In other words, it can be seen that the material of the present invention has a lower freezing point in all of the contrasting samples, and the material of the present invention is also far more stable in terms of oxidation stability and thermal stability.

[Table] *: Using a product manufactured by Emery Co. When using the synthetic ester of the present invention as a rolling oil, the synthetic ester alone can also be used as the rolling oil. It can also be used in combination with other base oils, such as mineral oils and animal/vegetable oils.
It is also possible to add an emulsifier to these and use them as an emulsion liquid. In addition, emulsifiers, fatty acids, antioxidants, which are commonly used as additives in mineral oils, animal/vegetable oils, and practical rolling oils, which are generally used as base oils,
It can also be used in combination with corrosion inhibitors. When the synthetic ester compound of the present invention is mixed with other base oils, etc., the effect is observed when it is added in an amount of 1% by weight or more, but the content should be 5% by weight or more, preferably 20% by weight or more. The characteristics become stable. An example of a method for synthesizing the synthetic ester of the present invention from a fatty acid and a glycol ether is shown below, but the present invention is not limited to this method, and other conventionally known synthesis methods such as the acid chloride method may be used. It is also possible to use known synthesis methods such as the like. Reference example 5 moles of palmitic acid and 6 moles of isopropylene glycol monoisopropyl ether were charged into a 4-necked flask equipped with a stirrer, thermometer, nitrogen gas blowing tube, and water separator, and 0.1% of the total amount was charged as a catalyst.
of sulfuric acid was added, the mixture was thoroughly stirred using excess isopropylene glycol monoisopropyl ether as a refluxing solvent, and the mixture was reacted at 160 to 230°C until the calculated amount of water was distilled out. The required time was 8 hours. After the reaction was completed, the catalyst was removed by washing with water, and unreacted glycol was distilled off under reduced pressure, followed by decolorizing filtration using activated clay to obtain a yellow liquid. yield
It had an acid value of 0.9 and a saponification value of 164. Synthetic esters were produced in the same manner using different types of fatty acids and glycol ethers. Next, the present invention will be described in more detail by way of examples. (Examples) Example 1 A hot rolled pickled steel sheet was cold rolled and annealed using the synthetic esters shown in Table 1 solely as rolling oil. Lubricity and annealing properties during cold rolling were evaluated using the following methods. The results are summarized in Table 2, and the symbols A to C in the table are the same as in Table 1. For the evaluation of lubricity, a 2.30 mm hot-rolled pickled steel plate was used, three passes of cold rolling were performed, the steel plate rolled to 1.20 mm was degreased, and each sample oil was diluted to 5.0% with n-hexane. The steel plate was immersed in an oil bath for a certain period of time, and the steel plate was uniformly and quantitatively coated with rolling oil in which the solvent had been volatilized, and then subjected to cold rolling. The rolling load at a reduction rate of 45% was measured to evaluate rolling lubricity. In addition, Bauden type friction tester (load 1
The lubricity of the rolling oil was evaluated by determining the friction coefficient of each rolling oil based on the temperature (kg, temperature: 100°C). For evaluation methods regarding the annealing properties of rolling oil, please refer to
An amount equivalent to approximately 630 mg/m ² of each test oil was dropped onto the surface of a cold-rolled steel plate (80 x 100 x 0.8 mm) using a microsyringe, and a cold-rolled steel plate of the same size was placed on top. After stacking several dozen steel plates in this way,
The specimen was fixed with a narrow steel strip and annealed in a small annealing furnace. The heating conditions during annealing are HNX gas (H ₂ : 5%)
Temperature increase rate is 10℃/min in 120ml/min atmosphere
The mixture was heated to 600°C, held at 600°C for 1 hour, and then allowed to cool. Thereafter, a cellophane tape was attached to the surface of the steel plate, and the surface deposits were collected and attached to white paper to visually determine the degree of contamination, and the cleanliness of the steel plate surface was evaluated. The results of the evaluation of rolling lubricity using a single-component rolling oil, the measurement results of lubrication properties using a Bowden lubrication tester, and the test results of direct annealing properties are summarized in Table 2. Example 2 Next, when mineral oil or beef tallow, which is used as the base oil of practical rolling oil, is blended with commonly used additives such as emulsifiers, fatty acids, antioxidants, etc., and the synthetic ester which is the rolling oil of the present invention. The lubricity and annealing properties of the obtained rolling oil composition were evaluated in the same manner as in Example 1. In addition, emulsion rolling was performed using a two-high roll rolling mill, and the rolling load of the rolled material (SPCC) 1.2 x 20 x 200 mm was measured at a rolling reduction rate of 40% under the conditions of an oil concentration of 3% and a bath temperature of 50°C to determine the rolling lubricity. was evaluated. As for annealing properties, tens of steel plates rolled with the sample emulsion liquid were stacked together, fixed with a narrow steel strip, and annealed in a small annealing furnace. The annealing conditions are the same as in the case of using rolling oil alone in the previous example. The method for determining surface cleanliness is also the same.

[Table] (Effects of the Invention) The synthetic ester compound obtained from the fatty acid and glycol ether of the present invention was intended to be used as a rolling lubricant for steel plates, and its molecular design was performed taking into consideration the necessary conditions for that purpose. Unlike existing synthetic esters that are used as cold rolling oil or as additives, the rolling lubricity of steel plates,
It has excellent annealing properties.

Claims (1)

[Claims] 1 General formula RCOO-(R'-O)n-R''...(1) [In the formula, R: Alkyl group having 7 or more carbon atoms R': Alkyl group R'': Alkyl group (However, , R, R' or R'', at least one of which is necessarily a branched alkyl group) n = an integer of 1 to 5] Contains an esterification product of a fatty acid and a glycol ether represented by Cold rolling oil for steel sheets characterized by: 2. R in general formula (1) is a linear fatty acid such as octyl acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, A group selected from montanic acid and side chain fatty acid residues of isooctylic acid, isodecanoic acid, isolauric acid, isomyristic acid, isopalmitic acid, isostearic acid, and isoaracic acid, and R' is ethyl or propyl. , isopropyl, butyl, is an alkyl group selected from isobutyl groups, and R″ is methyl, ethyl, propyl,
Isopropyl, butyl, isobutyl, pentyl,
The steel sheet according to claim 1, characterized in that it contains an esterification product of a glycol ether and a fatty acid that is an alkyl group selected from isopentyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, and isooctyl. Cold rolling oil.