JPH02124998A - Cold rolling oil - Google Patents

Abstract

PURPOSE:To obtain a cold rolling oil excellent in both stability and lubricity and scarcely causing contamination by emulsifying and dispersing a lubricating oil component in water containing a specified polymeric dispersant. CONSTITUTION:A polymeric dispersant composed essentially of a phosphate of a copolymer (having a molecular weight of 1,000 to 1,000,000) containing both repeating units of formula I (wherein L is H or methyl; M is alkylene oxide; n is 1 to 100; R1 is H, or 1-24C alkyl or alkenyl) and repeating units of formula II (wherein X is H, Na or K; R2 is H or 1-24C aliphatic straight- chain alkyl) in a ratio of the former units to the latter units of 1:3 to 2:1 is dissolved in an amount of 0.3-5wt.%, based on a lubricating oil component, in water. This aqueous solution is mixed with 0.5-10wt.%, based on water, lubricating oil component wherein the base oil comprises one or more of a mineral oil, natural oil or fat, and a synthetic fatty acid ester, so that particles having a uniform particle diameter distribution are formed by pump shearing, etc.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a cold rolling method that can stably emulsify and disperse a lubricating oil component in water when cold rolling metal, and has even better lubricity. Regarding rolling oil.

(Prior art) Rolling oil is generally used for cold rolling for two purposes: (1) to reduce friction between the rolls and the rolled material, and (2) to cool the heat generated by the rolling process and friction. 1 to 1
It is used in a circulation system as a rolling oil coolant with 0% lubricating oil component emulsified and dispersed. When using this rolling oil coolant in circulation, two points are simultaneously satisfied: (1) Uniformly emulsifying and dispersing the lubricating oil components in water, and (2) Adhering the appropriate amount of lubricating oil components to the rolls and rolling materials to alleviate friction. It is necessary to do so. The rolling oil coolant currently in use uses a small amount of monomolecular surfactant in order to satisfy the above conditions (1) and (2) at the same time, and is in an emulsion state (referred to as a loose emulsion) that cannot be made uniform without the use of a stirrer.
This increases the amount of lubricant components that adhere to rolls and rolled materials.

(Problem to be solved by the invention) However, in such a loose emulsion, the emulsion state deteriorates when it is made up (when new oil is poured) due to deterioration of the components due to wear particles generated during rolling work and absorbed heat. The emulsion changes more significantly, making it impossible to obtain a uniform emulsion state, leading to problems such as an increase in the amount of replenishment and an unstable rolling state. In such cases, the rolling oil coolant is generally replaced with new rolling oil coolant (dumped out).

If a large amount of monomolecular surfactant is used to stabilize the above emulsion state, the amount of lubricant component that adheres to the rolling material and rolls will be insufficient, and heat marks and chattering will occur due to insufficient lubrication, making rolling operations impossible. becomes. Therefore, at present, it is not possible to obtain a rolling oil that maintains a stable emulsified dispersion state for a long period of time and exhibits good and stable lubricity.

The present invention aims to supply a rolling oil coolant that does not have the above-mentioned problems, that is, it is uniform, has good circulation stability, has an emulsion state that does not change much even when wear particles are mixed in, and has good lubricity that does not change much. At the same time, the purpose is to provide a satisfying rolling oil.

(Means for Solving the Problems) As a result of intensive research in order to solve the above problems, the present inventors found that by diluting a specific polymer dispersant in water and emulsifying and dispersing lubricating oil components, The present invention was achieved by discovering that the object of the present invention can be achieved.

That is, the cold rolling oil of the present invention has (A) a lubricating oil component whose base oil is one or more selected from the group consisting of mineral oils, natural oils and fats, and synthetic fatty acid esters, and (B) the following general formula: (1) and (2) 0(M), -R.

(In the formula, M is a hydrogen atom or a methyl group, M is an alkylene oxide, n is an integer of 1 to 100, and R1 is a hydrogen atom or an alkyl group or alkenyl group having 1 to 24 carbon atoms)
, i X C)12 H2 (X in the formula is a hydrogen atom, sodium or potassium, R2
represents a hydrogen atom or an aliphatic linear alkyl group having 1 to 24 carbon atoms).
It is characterized by being emulsified and dispersed in water using a polymeric dispersant containing a phosphate having a molecular weight of 1.000 to 1.000.000 as an essential component.

(Function) The lubricating oil components used in the present invention include mineral oils such as machine oil (K-2238) and turbine oil (Ni-2213) listed in the Japanese Industrial Standards, pig intestine, beef tallow, fish oil, rapeseed oil, and palm oil. Natural fats and oils such as oil, coconut oil and rice bran oil, fatty acids obtained by decomposing these fats and oils, and aliphatic monohydric alcohols and polyhydric alcohols such as pentaerythritol, neopentyl alcohol, ethylene glycol and propylene glycol. One or more types selected from the group consisting of esters, or synthetic fatty acid esters such as esters of polymerized fatty acids such as dimers or more of unsaturated fatty acids and aliphatic monohydric alcohols can be used as the base oil. In addition to the above base oil, the lubricating oil components include oily agents and extreme pressure agents as necessary.

It contains various additives such as rust preventives, antioxidants, pour point depressants, etc., and is appropriately adjusted depending on the type and characteristics of the rolling mill, the rolling conditions of the material, etc.

In the polymer dispersant, which is an essential component of the present invention, the monomer portion of formula 1 has the function of strongly adsorbing the polymer dispersant to the emulsion particle surface, and the monomer portion of formula 2 has the function of strongly adsorbing the polymer dispersant to the emulsion particle surface.
It has the effect of increasing the ionicity of the emulsion particle surface to which the dispersant is adsorbed.

To explain these effects, the monomer portion of formula 1 has an alkyl group or an alkenyl group (R1). This part acts as a lipophilic group and becomes strongly adsorbed onto the surface of the emulsion particles.

Regarding polymer dispersants, JP-A-61-24629 has already been published.
Dispersants disclosed in No. 3 and JP-A No. 61-283694 are known, but the former does not have a suitable alkyl group that is easily adsorbed onto the particle surface. In the latter case, an alkyl group is bonded to the side chain, but since it is close to the main chain, it is thought that the adsorption property will not be strong due to the bulkiness of the ionic side chain. In Bunmu 2, the polarity of the nitrogen atom becomes stronger due to the oxygen in the hydroxyethyl group bonded to the nitrogen, and when it becomes a phosphate, it exhibits effective cationic properties, thereby increasing its adsorption to metals.

In order to simultaneously and effectively exhibit the effects of formulas 1 and 2, it is desirable that the ratio of the copolymer is 1 = 1 = 3 to 2:1. These two effects form a strong colloidal film on the surface of the emulsion particles, and the emulsion particles become difficult to coalesce together due to the repulsive force caused by the ionic charges on the surface. Therefore, the emulsion particles formed by sufficient shearing become stable in water and exhibit a uniform dispersion state when stirred by an agitator or the like.

The polymer dispersant used in the present invention increases its adsorption to metals by increasing its ionicity. Furthermore, this polymeric dispersant exhibits the property of being completely soluble in water but insoluble in oil. As a result, wear particles mixed into the rolling oil coolant are strongly adsorbed to the colloid coating on the surface of the emulsion particles, but cannot penetrate into the emulsion particles. Due to this effect, even if abrasion particles are mixed in, the emulsion particles will not change much, and circulation stability during use will be improved.

Furthermore, even if contamination called scum, which is a mixture of wear powder and lubricating oil components found in conventional rolling oil coolant, occurs, it is possible to keep the area around the machine clean.

Emulsion particles in the rolling oil coolant supplied to the rolling material and rolls during rolling operations are easily adsorbed to iron due to the effect of ionized nitrogen atoms on the highly ionic colloidal coating surface, forming a dense and strong single particle. A particle adhesion layer (hereinafter referred to as a single particle adhesion layer) is formed. The lubricating oil component is dense and firmly adhered to this single particle adhesion layer, so the amount of adhesion does not decrease due to turbulence of the emulsion at the roll inlet, and it is effective in alleviating friction between the roll and the rolled material, resulting in lubricity. will improve.

The amount of single particle deposition depends on the size and uniformity of the particles. The polymer dispersant used in the present invention can obtain a uniform particle size distribution by appropriately selecting the side chain substituents depending on the rolling oil base oil, and it is possible to obtain a uniform particle size distribution by changing the concentration of the polymer dispersant. This allows the average particle size of the emulsion particles to be controlled to the required state. In order to fully demonstrate the performance of the lubricating oil component, it is desirable that the active ingredient of the polymer dispersant be in the range of 0.3 to 5% by weight based on the lubricating oil component.

How to use The cold rolling oil of the present invention is prepared by dissolving a predetermined polymer dispersant in water, adding 0.5 to 10% of the lubricating oil component to the water, and forming particles with a uniform particle size distribution by pump shearing or the like. It is preferable to form it and then use it for circulation.

(Example) The present invention will be explained below with reference to Examples and Comparative Examples.

Examples 1-4. Comparative Examples 1 to 4 Examples 1 to 4 were carried out using polymer dispersants A to D shown in Table 1 and according to the formulations shown in Table 2. Rolling oils for Comparative Examples 1 to 4 were prepared. Table 2 also lists performance test results confirmed by the following test method.

Table 1 Test method 1) Circulation test sample Add 10g of commercially available fine powdered iron powder (200 people, manufactured by Vacuum Metallurgy) to oil emulsion 2H (3% 50-55°C),
Daily circulation (5β/min nozzle, full cone 086
5) Conduct a test and check the condition of the emulsion particles using a coulter
The particle size (μm) is measured using a counter, and at the same time, the state of dirt inside the tank is also observed.

Judgment 2 〇 No stain, △ Contamination, × Large stain 2) S-45C roll and rolling roll (Cr
=3%, Hs=80~85) (Both length 100m
240 m in diameter) under the following conditions, and the coefficient of friction was determined using the formula below.

(Conditions) Rolling oil; 3% 50-55℃ emulsion circulation 1.5
hr (151/min gear pump) 6 A/min oil supply Roll temperature; 50-55°C Roll speed; Roll load; Material roll 500 m/min Rolling roll 550 m/m1n 5 tons = 55 kgf/mm" 3 tons = 37 kgf/mm2 T = Rolling Axial torque W during sliding = Load R = Roll radius (Effects of the invention) The cold rolling oil of the present invention, which is a dispersion in which lubricating oil components are emulsified and dispersed in water using a specific polymer dispersant, is As shown in Table 2, a comparison of Examples 1 to 4 and Comparative Examples 1 to 4 shows that there was very little change in the dispersed particle size over time in the circulation test, indicating stable dispersion, and no staining. It turned out that there were very few.

°Furthermore, it was found that the friction coefficient in the lubricity test was low and the lubricity was excellent. Thus, the present invention has achieved the initial objective of producing a cold rolling process that is highly stable, has very little contamination, and has excellent lubricity even under the conditions of actual rolling operations in which wear particles are mixed and circulated. It was confirmed that rolling oil was obtained for the first time.

Patent applicant: Kyodo Yushi Co., Ltd.

Claims (1)

[Claims] 1. (A) A lubricating oil component whose base oil is one or more selected from the group consisting of mineral oils, natural oils and fats, and synthetic fatty acid esters, (B) the following general formula ( 1) and (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (1) (L in the formula is a hydrogen atom or a methyl group, M is an alkylene oxide, n is an integer from 1 to 100, R_1 is a hydrogen atom or a carbon ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (2) (X in the formula represents a hydrogen atom, sodium or potassium, R_
2 represents a hydrogen atom or an aliphatic linear alkyl group having 1 to 24 carbon atoms) A phosphate of a copolymer (molecular weight 1,000 to 1,000,000) is an essential component. A cold rolling oil characterized by being emulsified and dispersed in water using a polymeric dispersant.