KR100482203B1 - An Additive For Rolling Oil and Rolling Composition Comprising The Same - Google Patents

Abstract

There is provided a rolling oil additive added to the rolling oil and a rolling oil composition comprising the same. The rolled oil additive comprises at least one ester selected from hindered triesters of 20 to 40% by weight of C8 to C12 fatty acids and diesters of 10 to 20% by weight of C12 to C18 fatty acids based on the total weight of the rolled oil composition; And 1 to 5% by weight of a C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid, the rolling oil composition comprising the same has excellent heat stability and improved degreasing property of the material after rolling.

Description

Rolled oil additive and rolling oil composition comprising the same {An Additive For Rolling Oil and Rolling Composition Comprising The Same}

The present invention relates to a rolling oil additive added to rolling oil for the purpose of lubrication for rolling of general steel and electrical steel, in particular electrical steel, and a rolling oil composition comprising the same. More specifically, the present invention exhibits a stable lubrication state as well as a low thermal change of the rolling oil during the warm processing of the electrical steel sheet, which has a higher deformation resistance than the general steel and the temperature conditions of the material are more severe (250 ° C). It relates to an additive used in rolling oil for electric steel sheet having good oil resistance and a rolling oil composition comprising the same.

The water-soluble cold rolled oil used for the conventional electrical steel sheet is basically configured similar to the cold rolled oil for general steel. In the case of cold rolled oil, base oils (base oils) include animal and vegetable oils and mineral oils, and oil additives such as fatty acids and alcohols, extreme pressure additives, antirust additives, antioxidants, and emulsifiers have been used as additives. In the actual use, such cold rolled oil is diluted with water at a concentration of 1 to 15% by weight, prepared in an emulsion state, and circulating and used rolling oil in an emulsion state.

On the other hand, the rolling equipment has been speeded up and thinned through new painting, and the rolling condition of the GO materials (HGO, CGO) having high added value in terms of materials has increased (increasing the hot rolling amount) and the rolling conditions have been severe (material release temperature; 170 ° C. to 250 ° C.) Therefore, the demand for heat stability and work stability of rolling oil is increasing.

However, the conventionally used rolling oil had the following problems with respect to the required rolling oil properties.

Conventionally, as a base oil (base oil) of rolling oil, mineral oil was mixed and used for fat and oil holding with excellent lubricity. However, in the case of electric steel sheet, the high temperature frictional heat, processing heat and pressure conditions generated during rolling are more severe than those of general cold rolling. Easily generated. The oxidatively modified rolling oil is adhered to the material through the rolling operation and causes a serious effect on the post-degreasing degreasing process.

In addition, deteriorated oil combines with iron produced during rolling to produce a lot of scum material. Scum material has a negative effect on the environment by polluting the rolling mill and surroundings.

The present invention is to solve the problems with the conventional rolled oil for electrical steel sheet, an object of the present invention is to provide a rolled oil additive that provides excellent heat stability, degreasing resistance, emulsion stability and pollution resistance to the rolling oil.

Another object of the present invention is to provide a rolled oil composition having excellent heat stability, degreasing resistance, emulsion stability and fouling resistance, comprising the rolling oil additive of the present invention.

According to one aspect of the invention,

At least one ester selected from hindered triesters of 20 to 40% by weight of C8 to C12 fatty acids and diesters of 10 to 20% by weight of C12 to C18 fatty acids based on the total weight of the rolled oil composition; And 1 to 5% by weight of a C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid.

According to another aspect of the present invention,

At least one ester selected from hindered triesters of 20 to 40% by weight of C8 to C12 fatty acids and diesters of 10 to 20% by weight of C12 to C18 fatty acids based on the total weight of the rolled oil composition; And a rolling oil additive composed of 1 to 5% by weight of a C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Conventionally, as a base oil (base oil) of rolling oil, mineral oil was mixed and used for fat and oil holding with excellent lubricity. However, in the case of electrical steel sheets (especially CGO materials), due to the high frictional heat, processing heat, and pressure conditions generated during rolling, the chemical reactions such as hydrolysis occur easily in rolling oil using animal and vegetable fats and oils. As the rolled oil is easily oxidized or a polymer material is easily produced, a large amount of scum material is formed. In addition, since the viscosity change due to high temperature oxidation is large, it acts as a detrimental factor in the stable rolling operation, resulting in a decrease in the degreasing rate in the post-degreasing operation.

Therefore, in the present invention, in order to improve the heat stability, lubricity and degreasing resistance of the conventional rolling oil, the hindered triester of C8-12 fatty acid having excellent heat stability and diester of C12-18 fatty acid having good lubricity alone or in combination Can be added. The hindered triester of C8-12 fatty acid has a lower viscosity than the diester of C12-18 fatty acid.

In addition, an alkylester emulsifier of pentaerythritol fatty acid is added to the conventional rolled oil composition at 1 to 5% by weight based on the total weight of the emulsifier composition.

The esters and emulsifiers are added to conventional rolling oils in order to improve heat resistance, lubricity, degreasing property, emulsification stability and fouling resistance, which are conventionally used. Therefore, it does not limit the kind and amount of other additives such as refined mineral oil, natural fat, emulsifier, extreme pressure additive, antioxidant, rust preventive agent, lubricant, and the like as base oil, which may be appropriately selected by those skilled in the art.

The hindered triester of C8-12 fatty acid is a reaction product of a polyhydric alcohol and C8-C12 linear or branched fatty acid, and acts as a base oil component in rolled oil to exhibit excellent heat stability. It is used at 20 to 40% by weight based on the total weight of the rolled oil composition. If the content of the hindered triester is less than 20% by weight, the lubricity decreases. If it contains more than 40% by weight, the lubricity is excellent, but the workability (slip occurrence) is a problem due to poor rolling workability.

The diester of C12-18 fatty acid is a reaction product of polyhydric alcohol and C12-C18 linear or branched fatty acid. It has excellent lubricity and is involved in viscosity control of rolling oil, which is one of the important factors in rolling. It is contained in 10 to 20% by weight based on the total weight of the rolling oil composition. When it contains less than 10 weight%, lubricity falls. When it contains 20% by weight or more, the lubricity is excellent, but the rolling workability is inferior due to slip generation due to the use of small diameter rolls.

The ester acts as a base oil component and these may be used alone or in combination. By using these together with refined mineral oil, the heat stability and the degreasing resistance of the rolling oil are improved.

As the natural fat or oil, one or two or more oils selected from the group consisting of tallow, palm oil and palm oil may be used together. Natural fats and oils are used in amounts of up to 20% by weight, preferably 5 to 20% by weight, based on the total weight of the rolled oil composition. Natural fats and oils may help degreasing as the amount added, but when the amount exceeds 20% by weight, rolling workability and pollution resistance is reduced.

In addition, the remainder of the total rolling oil composition including the additives described later is a refined mineral oil that has conventionally been used as a main component of base oil.

On the other hand, the emulsifier is applied so that the rolled oil is easily emulsified, which acts directly when the rolled oil is emulsified by diluting with water. Rolling lubrication is adjusted by the magnitude of the amount (plate out property) of oil adhering to the rolling material surface which is increased or decreased according to the addition amount of the emulsifier. In addition, the rolling operation stability also depends on the size and distribution of the rolling oil particle diameter formed by the emulsifier.

However, in the rolling conditions of high temperature and high pressure, the emulsifier is thermally denatured in addition to the base oil, thereby reducing the emulsifier inherent emulsification performance and promoting scum formation. On the other hand, in the recent rolling process, not only the rolling stability but also the cleanliness of the rolling mill or the rolled plate surface are required, so that the uniformity of the surface of the rolled plate and the ease of managing the rolled oil are important.

In other words, in order to improve the rolling work environment, less scum is generated during rolling and the processing is easier to clean the surroundings of the rolling mill, and uniform particle size is maintained, so that operation is stable even at high speed, high pressure, and high temperature rolling conditions. The required characteristics are required.

These properties cannot be solved entirely with the base oil alone, and are closely related to the emulsifying properties of the emulsifiers essential for the emulsification of the rolling oil together with the overall combination of various additives such as lubricant additives and antioxidants.

Accordingly, in the present invention, the use of C12 to C18 alkyl ester emulsifiers of pentaerythritol fatty acid having excellent thermal stability together with nonylphenol-based, amine-based and glycol-based emulsifiers, which are conventionally used as emulsifiers, suppresses scum generation. And particle size distribution becomes uniform. By uniform particle size distribution, rolling operation stability is increased.

For the rolling operation stability through the maintenance of uniform particle size during rolling use of the rolling oil, the C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid is preferably used at 1 to 5% by weight based on the total weight of the rolling oil composition.

If the content is less than 1% by weight, the effect of suppressing scum generation of the rolling oil cannot be obtained. If the content is more than 5% by weight, the degreasing property and the emulsion stability decrease.

Nonylphenol-based emulsifiers, amine salt-based emulsifiers and glycol-based emulsifiers can be formulated in amounts generally used by selecting those commonly used in the art. Accordingly, the type and content thereof are not particularly limited, but for example, the nonylphenol-based emulsifier is in an amount of about 2 to 4% by weight based on the total weight of the rolled oil composition, and the amine salt-based emulsifier is the total weight of the rolled oil composition. In an amount of about 1 to 2.5% by weight and glycol-based emulsifiers may be used in an amount of about 0.5 to 3% by weight based on the total weight of the rolled oil composition.

In the rolling oil composition to which the rolling oil additive of the present invention is added, other additives such as extreme pressure additives, antioxidants, antirust additives, lubricating additives, and microbial growth inhibitors, which are generally used in the art, may be added as necessary. These types and amounts used are generally known in the art, and are not particularly limited.

As the extreme pressure additive, phosphorus-based and sulfur-based extreme pressure agents which are used as extreme pressure additives of ordinary cold rolling oil may be used. Examples of phosphorus suppressors include, but are not limited to, phosphate derivatives of aliphatic amines, phosphate derivatives of aromatic amines, zinc dithio posphate, trialkyl phosphates.

Examples of sulfur extreme pressure agents include, but are not limited to, sulfide oils, aromatics such as dididodecyl trisulfide, dibenzyl pentasulfide, or -CS-, -SS-,- Extreme pressure agents having a structure of SSSS-.

The extreme pressure additive may be used within 5% by weight based on the total weight of the rolled oil composition. There is a limit to the improvement of the extreme pressure lubrication characteristics of cold rolled oil according to the increase of the extreme pressure additive, and when added in excess of 5% by weight, the emulsion stability of the rolled oil is lowered. Such emulsion instability acts as a deterrent to operational stability.

Examples of lubricating additives include, but are not limited to, stearic acid, Uji fatty acid, palm fatty acid, oleic acid, C30-C36 dimer acid. The lubricant additive may be used within 8% by weight based on the total weight of the rolled oil composition. There is a limit to the improvement of lubricity of cold rolled oil for electrical steel sheet by increasing the amount of lubricating additive. When it exceeds 8% by weight, the occurrence of scum by fatty acid dagger during rolling oil is increased. Is lowered.

As the antioxidant, a phenol-based antioxidant, more specifically, a derivative of diphenylamine and the like may be used in an amount of 0.5 to 2% by weight based on the total weight of the composition. When added at less than 0.5% by weight, the effect of inhibiting viscosity increase and the formation of gum substances due to oxidation of the rolling oil during the rolling condition is weak, and the effect is not increased even if added at 2% by weight or more.

As the rust preventive additive, for example, but not limited to, an amine derivative, more specifically trialkyl amine, may be used in an amount of 2 to 4% by weight based on the total weight of the rolled oil composition. When added at less than 0.5% by weight, the rust prevention effect of the rolling oil is weak, and when more than 4% by weight is added emulsified instability due to the pH change of the rolling oil.

Microbial growth inhibitors are not limited to this, but for example, sodium benzoate salt derivatives may be used in less than 1% by weight based on the total weight of the rolled oil composition. The microbial growth inhibitor suppresses the formation and growth of scum material formed around the rolling mill during rolling operation, and suppresses the corrosion of rolling mill by iron bacteria (contained in scum), but the effect is higher even when added in excess of 1% by weight. It is no longer augmented.

Rolled oil composition comprising the additive of the present invention is diluted with water when in use is applied at a concentration of 1 to 15% by weight.

The rolling oil additive of the present invention and the rolling oil composition containing the same are applicable to the rolling of any steel sheet, and are particularly advantageously used for rolling electrical steel sheets. More preferably it is advantageously used for rolling oriented electrical steel sheets (GO materials).

Furthermore, the rolling oil additive of the present invention and the rolling oil composition including the same do not limit the temperature at the rolling conditions to which the rolling oil additive is applied.

Hereinafter, the present invention will be described in more detail according to examples.

(Example 1)

The results and overall evaluation results of the thermal stability, degreasing resistance, lubricity, stain resistance and emulsification stability of the Comparative Examples 1 to 6, Inventive Examples 1 to 4, and the conventional rolled oil composition, as shown in Table 1, were measured. It is shown in Table 1 below.

Test Items and Test Methods

■ Thermal stability test (RBOT method, ASTM D 2272)

The heat stability was evaluated by measuring the time in which the pressure in the cylinder showed a pressure drop of 1.75 kgf / cm 2 (172 kPa) at the maximum pressure under the following conditions, and the results are shown in Table 1 below.

As can be seen from Table 1, in the case of the invention example, the heat stability was increased as compared with the conventional rolling oil.

In addition, the iodine number (IV) of the rolled oil composition is shown in Table 1, from which it can be seen that the thermal stability of the rolled oil composition according to the present invention is increased.

Oxygen Pressure 6.3kgf / ㎠ (620kPa)

150 ℃ thermostat

Bomb angle 30 degrees

100 revolutions per minute

50 g of rolled oil, 5 ml of water and cocatalyst coil

■ Degreasing test:

Sample oil was prepared by dissolving each of the rolling oil compositions of Comparative Examples, Invention Examples and Conventional Examples at 25% by weight in hexane as an organic solvent. Thus, after immersing the clean washed test piece (Dipping) and dried for 24 hours, the degreasing test with a degreasing solution after heating for 2 hours to 150 ℃ in a dry oven, copper plating was carried out to observe the degree of degreasing. The results are shown in Table 1 below.

Degreaser: Caustic Soda and Osososilicate Complex Degreaser (concentration 3%), temperature 85 ℃

Copper plating solution: CuSO5H2O, 1%, 50 ℃

Degreasing time 10 seconds, plating time 10 seconds

Lubrication Evaluation (FALEX TEST and 4-BALL TEST (ASTM D-2783))

(1) The lubricity of each rolled oil composition was measured using a Falex Lubricant Tester. The results are shown in Table 1.

② The lubrication and fire resistance were evaluated using the shell type high speed sand ball tester, and the final arsenic and melting points are shown in Table 1.

③ The saponification value (SV) and the viscosity at 50 ° C. were measured and shown in Table 1 below.

■ Pollution resistance (measurement of pollution and scum production)

In the test apparatus of Figure 1 it was carried out under the following conditions. The rolled oil composition is placed in the vessel 1 and agitated with the stirrer 2 while being sprayed onto the specimen through a pump.

① Specimen fouling was circulated for 8 hours in each rolled oil, and then sprayed on the specimen for 1 hour to measure the amount of contamination attached to the specimen.

Rolling flow rate: 20 liters

Temperature 50-60 ° C, concentration 5% by weight,

Stirrer: Screw Type, 1200rpm / min.

Iron addition: 2,000ppm

Nozzle: 1/4 KBA02365

Pressure: 2.5 ㎏ / ㎠

Specimen: SPCC 1mmt × 60 × 80mm

(Evaluation standard)

Contaminant (Sample) Item: ○: Contamination amount 40mg / ㎡

○ △: contamination amount 40 ~ 80mg / ㎡

△: contamination amount 80-120mg / ㎡

×: contamination adhesion amount 120 mg / m 2 or more

② The amount of scum generated was suspended in 50 Hr. In the test apparatus of FIG. 1, the stirring was stopped, and the amount of scum scum of the upper portion of the tank was measured.

 O: Less scum occurrence (0-2 cm height of scum layer in tank)

ㅿ: middle of scum occurrence (2-4 cm in height of scum layer in tank)

X: High scum occurrence (more than 4cm in height of scum layer in tank)

Emulsification stability (measurement of particle size and ESI measurement)

In the test apparatus of FIG. 1, the rolling oil emulsion having a concentration of 5% by weight was circulated for 30 hours, and the average particle diameter, shape, and ESI-15 'of the emulsion were measured by a Coulter Counter.

ESI-15 'was put into a 200ml separator in the stirred rolling oil emulsion in the test apparatus of Figure 1 and allowed to stand in a thermostat (50 ℃) for 15 minutes and 100ml was collected from the bottom to measure the concentration.

Average particle size distribution: S = Sharp: More than 80% of particles in 10㎛ distribution

M = Medium: More than 80% of particles in 15㎛ distribution

B = Broad: less than 80% of the particles in the 15㎛ distribution.

Slip resistance evaluation

Each rolled oil composition of Table 1 as a 5% by weight emulsion in a small pilot mill roll diameter: 100mm, rolling reduction test by directional CGO material at a rolling reduction of 40% to observe the slip generation state.

○: No slip

△: slight slip occurrence

×: slip occurrence

[Table 1] (Content unit of each component: wt%)

Comparative oil 1 Comparative oil 2 Invention 1 Invention 2 Invention 3 Comparative oil 3 Invention 4 Comparative oil 4 Invention 5 Comparative oil 5 Comparative oil 6 Conventional oil Refined mineral oil 52 33 33.25 33.5 33.5 24.5 22.5 30 31.5 33 43 33 Synthetic Oil A Synthetic Oil B 10- 10- 20- 30- 40- 50- 2010 2010 -20 -30 -30 - Natural oil Uji 10 Palm oil 20 Palm oil 10 Palm oil 20 Palm oil 10 Maintain 20 Palm oil 10 Palm oil 20 Palm oil 10 Palm oil 20 Emulsifier 1 Emulsifier 2 Emulsifier 3 Emulsifier 4 31.50.54 2.521.52 2.51.751.53 2.51.522 21.532 3212 2.5115 2.51.5-7 3.5213 2.51.522 42.51.5- 42.51.5- Extreme pressure additive 5 5 5 5 5 5 5 5 5 5 5 5 Lubricant Additive 8 8 7 8 7 7 7 8 8 8 8 8 Antioxidant 1.5 1.5 1.5 One 1.5 One 1.5 1.5 1.5 1.5 1.5 1.5 Other additives 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 4.5 Sum 100 100 100 100 100 100 100 100 100 100 100 100 Thermal stability and degreasing ○ ○ ○ ○ ○ ○ ○ × ○ ○ ○ × Thermal stability (RBOT, min) Degreasing rate (%) IV (mgKI / g) 16 8018 16 8026 15 8032 16 8031 16 8027 18 8028 15 8035 12 4038 15 8031 13 6043 16 8036 11 4064 Lubricity × ○ ○ ○ ○ ○ ○ ○ ○ ○ × ○ Falex Test Small load (Lbs.) High speed sand ball test (final arsenic point) (kg) (fusion point, kg) SV (mgKOH / g) Viscosity (50 ° C, cSt) 2000 50126105 31 2500 50160140 29 2250+ 50160131 33 2250+ 50160130 30 2500 50200132 28 2500 50200153 27 2250+ 50160129 31 2500 50160140 30 2250+ 50160132 34 2500 63200120 38 2000 50126102 32 2250+ 50160120 35 Pollution resistance ○ △ ○ ○ ○ ○ ○ △ ○ ○ △ × Contaminated (Sample) Tank Floating Scum ○○ ○ △△ ○○ ○○ ○○ ○○ ○○ ○ △△ ○○ ○○ ○ △△ △ × Oil painting stability ○ ○ ○ ○ ○ ○ ○ △ ○ ○ × × Particle Size (µm) Particle Type ESI-15 ' 4.5S95 4.5M92 4.5S92 5S92 5M92 4.5S95 4.5S90 4.5B90 5M92 4S95 4.5B88 5B85 Slip resistance ○ △ ○ ○ ○ × ○ ○ ○ × ○ ○

Synthetic Oil A: Hindered Triesters of C8-12 Fatty Acids

Synthetic oil B: diesters of C12-18 fatty acids

Emulsifier 1: Nonylphenyl EO Adduct Ether Emulsifier

Emulsifier 2: Salts of branched chain hydrocarbon amines with fatty acids (C8-12)

Emulsifier 3: PEG 400 Fatty Acid Ester

Emulsifier 4: C12-18 Alkyl Ester of Pentaerythritol Fatty Acid

Extreme pressure additive: mixed use of phosphate derivative of aliphatic amine salt derivative and aromatic amine

Lubricant Additives: Palm Fatty Acid

Antioxidant: Diphenylamine Derivative

Other additives: 4 wt% of trialkylamine as an additive

            0.5 wt% sodium benzoate derivative as microbial growth inhibitor

Example 2 Rolling Test

After a rolling test of the conventional rolled oil and the rolled material of Inventive Example 1 using a 300Ton-class 4Hi test mill, specimens were taken and tested for degreasing under the following conditions.

Test condition: Degreasing agent (3%, temperature 85 ℃) used in electrical steel sheet factory

Copper plating solution: 1%, 50 ℃, Degreasing time: 2 seconds, Plating time: 2 seconds

[Table 2] Specification of Test Mill

Rolling mill type 4-stage reversible rolling mill Rolling load 300ton Tension 4000 kgf Max rolling speed 200 mpm Work roll 100 mm Work roll barrel length 470 mm Rolling Material-Coil Thickness-Coil Inner Diameter-Coil Outer Diameter-Sheet Width-Rolled Material 508 mm 1100 mm 150 mm Electric steel pickling coil Class 2 A material: High-grade CGO low temperature material (directional) B material: Non-oriented NO material Rolling oil supply system-Supply method-Tank capacity-Maximum injection amount-Rolled oil Temperature stirrer Rotating speed 3000 liters 260 liters / minute 50 degrees Celsius 1800 rpm

TABLE 3

Rolling condition Conventional oil (% degreasing) Invention oil 1 (degreasing rate%) Grater Rolled oil concentration (% by weight) Amount of scum added (ppm) A ash 10 0 65 95 B ash 10 0 70 90 A ash 10 1000 80 95 B ash 10 1000 65 85 A ash 8 2000 75 90 B ash 8 2000 85 95

A ash: high quality CGO (directional)

B ash: non-oriented NO ash

Degreasing evaluation using the test rolled specimen showed that the invention oil (1) improved the degreasing performance by 30% or more on average compared to the conventional oil.

By using the rolling oil additive for electrical steel sheet according to the present invention in addition to the rolling oil, it is excellent in heat resistance compared to the conventional rolling oil, and improves the degreasing property of the material after rolling.

1 is a schematic view showing the apparatus used in the evaluation of fouling resistance and lubrication stability of the rolled oil composition in the Examples.

   Brief description of symbols in the drawings

          1 .... vessel 2 .... agitator

          3 .... burner

Claims (5)

At least one ester selected from hindered triesters of 20 to 40% by weight of C8 to C12 fatty acids and diesters of 10 to 20% by weight of C12 to C18 fatty acids based on the total weight of the rolled oil composition; And 1 to 5% by weight of a C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid. At least one ester selected from hindered triesters of 20 to 40% by weight of C8 to C12 fatty acids and diesters of 10 to 20% by weight of C12 to C18 fatty acids based on the total weight of the rolled oil composition; And 1 to 5 wt% of a C12 to C18 alkyl ester emulsifier of pentaerythritol fatty acid. The rolled oil composition of claim 2, wherein the rolled oil composition comprises at least 20% by weight of the rolled oil composition based on the weight of the rolled oil composition. The rolling oil composition according to claim 3, wherein the content of the natural oil or fat is 5 to 20% by weight based on the weight of the rolling oil composition. The rolled oil composition according to any one of claims 2 to 4, wherein the rolled oil composition is used for rolling an electrical steel sheet.