JPS59126498A - Lubrication oil for cold rolling of aluminum - Google Patents

Abstract

PURPOSE:To provide a lubrication oil for cold rolling of aluminum, giving high rolling reduction and having excellent filterability and oxidation resistance and low tendency of oil staining, by adding a specific amount of a specific phosphite compound to a mineral oil. CONSTITUTION:The objective lubrication oil for the cold rolling of aluminum can be prepared by adding 0.01-5wt% (preferably 0.1-2wt%) of a phosphite compound of formula (RO)3P (R is 4-18C alkyl or aryl) [e.g. trisdecyl phosphite, tris(nonylphenyl) phosphite, etc.] to a mineral oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lubricating oil for cold rolling of aluminum.

The lubricating oil for aluminum cold rolling (hereinafter simply referred to as rolling oil) has the following characteristics.

+11 Excellent load-bearing performance (2) Good cooling performance (3) Good surface finish (4) Low oil stain property and (5)
Since good rolling workability is required, much research has been conducted to improve these properties.

Some of the inventors of the present application discovered that dialkyl phosphite-based compounds were effective as additives for rolling oil and filed an application (Japanese Unexamined Patent Publication No. 56-65095, hereinafter referred to as the "previous invention"). Although the dialkyl phosphite compound used in the above fully satisfies the above five properties.

(b) Since the optimum concentration range under certain rolling conditions is narrow, its control becomes difficult.

(b) The viscosity of the rolling oil gradually increases because the fine aluminum powder mixed into the rolling oil is quite common.

For example, if it is used continuously for about 2 to 3 months, the transient properties deteriorate and rolling workability deteriorates.

and.

(c) Due to long-term continuous use, the rolling oil deteriorates (increases in acid value), and the roll clogging becomes worse, making it impossible to maintain a high rolling reduction ratio, and the reactivity increases, making oil staining more likely.

It turns out that there is a drawback.

The rolling oil of the present invention has improved the problems of the previous invention described above, and has the general formula (RO) in mineral oil as a base oil.
The @ sign indicates that a phosphite compound represented by 3P has been added.

In the above general formula, R is an alkyl group or an alkyl group having 4 to 18 carbon atoms, for example.

04 Nibutyl, C8: Octyl, 2-ethylhexyl.

CI2 nilauryl, 0. , : 7 osphite compounds of each fatty acid alcohol of stearyl, and C6: feni/
l/, oa: xylyl*0+o: P-isobutylphenyl.

0□7: Examples include aryl group phosphite compounds such as nonylphenyl.

If the number of carbon atoms is 6 or less, a hydrolysis reaction due to trace amounts of water in the mineral oil is likely to occur, producing phosphoric acid that causes corrosion of rolling rolls and rolled materials, which is not preferable.
On the other hand, if it exceeds 18, the miscibility with mineral oil becomes poor, making it difficult to achieve the object of the present invention. In addition, the appropriate amount of phosphite compound added to mineral oil is in the range of 0.01 to 5% by weight; if it is less than 0.01% by weight, the addition has no effect, while if it is more than 5% by weight, the rolling roll Or, the 6M deviation toward the surface of the rolled material becomes worse. The preferred range is 0.1 to 2% by weight, since the change in properties of this additive depending on the amount added is smaller than in the previous invention.

Adjusting the rolling oil is easy.

In the rolling oil according to the present invention, additives conventionally used to increase the rolling reduction ratio, such as higher fatty acids (for example, lauric acid, myristic acid, oleic acid, stearic acid, etc.), higher alcohols (for example, lauryl alcohol, Myristyl alcohol, etc.) or esters of higher fatty acids (for example, lauric acid methyl ester, palmitin Y butyl ester, stearic acid butyl ester, oleic acid butyl ester, etc.) can be added at the same time. The amount is preferably 0.1 to 5% by weight based on the mineral oil (however, the total amount including the phosphite compound is 6% by weight or less).

Examples are shown below along with comparative examples (previous invention examples), and the test methods and evaluation methods are as follows.

(Hata) Apply rolling oil to both sides of an aluminum plate of the same thickness,
The specimen was rolled with the same roll gap using a multi-stage cold rolling mill, and the reduction ratio was determined from the thickness before and after rolling. The larger the rolling reduction ratio, the better the lubricity. The aluminum materials used were soft material (1100-0 material) and hard material (5052-0 material).
material).

(b) 5 omt of filterable rolling oil was filtered using a 0.22 μm Millipore filter, and the Fl filtration rate was determined.

(c) Degree of deterioration (acid value) Rolling oil was placed in an aluminum cup, kept in an air bath at 120°C for 46 hours, and the acid value was measured. The degree of deterioration was expressed as an increase in acid value obtained by subtracting the acid value before heating from the acid value after heating.

(d) Oil stain property Rolling oil is sealed between two aluminum plates, the whole is wrapped in aluminum foil, and this is heated at 650°C for 2 hours.
The surface condition of the plate was visually observed. The oil stains are listed as Man, B, O, and D in descending order of oil stain.

Table 1 of Examples shows the composition of rolling oil prepared by adding various additives to mineral oil having a kinematic viscosity of 3.97 inches at 100"F. The results are summarized in Table 2.The oil stain properties immediately after preparation of the rolling oil are almost the same in the examples and comparative examples (A-B
)Met.

Table 1 *% by weight From the above results, the rolling oil according to the present invention has improved the drawbacks of the rolling oil according to the previous invention that appeared after long-term use.

It is clear that it has excellent performance.

Patent applicant: Nippon Light Metal Co., Ltd.

Claims (1)

[Claims] Mineral oil has the general formula (RO), P (where 几 has a carbon number of 4).
A lubricating oil for cold rolling of aluminum, which contains 0.01 to 5% by weight of a phosphite compound represented by an alkyl group or an aryl group (N18).