JP2545312B2 - Cold rolling oil composition for stainless steel strip - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cold rolling oil composition for a stainless steel strip.

[0002]

2. Description of the Related Art Conventionally, in cold rolling of a stainless steel strip, rolling using a small diameter work roll having a diameter of 150 mm or less, such as Sendzimir rolling, is carried out because it is necessary to improve the surface gloss of the rolled steel strip. ing. Further, in order to improve gloss and ensure gloss uniformity, rolling oil is supplied and used as it is (hereinafter referred to as "neat oil").

Recently, in order to improve the productivity, the production of good stainless steel strip surface gloss by cold motor Ndemumiru with large diameter work roll has been attempted. However, rolled stainless steel strip by cold motor Ndemumiru, compared to the rolling with small-diameter work roll such as Zenjimia rolling, the temperature of the contact interface between the steel strip and the work roll is increased due to the large rolling load It is easy to supply neat oil like the case of using a conventional small diameter work roll.
When the method used is adopted, there is an unavoidable occurrence of a seizure flaw called a heat streak, and as a result, a product having a poor commercial value is obtained.

[0004] Therefore, recently, it has been considered a method of rolling have use the emulsion rolling oil was emulsified and dispersed in water in place of the neat oil (JP-63-393, JP-
Iwasaki et al., 38th Plastic Working Joint Lecture (1987), 1
13). However, such a method also be possible to apply the method to the case of rolling using a small-diameter work roll, the rolling by cold motor down de <br/> Mumiru with large work roll Has the drawback that the uniformity of surface gloss is significantly impaired, and only products with poor commercial value can be obtained.

Further, in the conventional stainless rolling oil, mineral oil must be used as a base oil in order to prevent clogging of the filter and improve the surface gloss, so that the lubricity is remarkably insufficient and a heat streak occurs. , it applied to the cold data Ndemumiru is quite difficult.

[0006]

[Present SUMMARY OF THE INVENTION The present invention, which has been made to solve the above drawbacks, when used during the cold data tandem rolled stainless steel sheet, lubricity generate good heat streak The resulting product provides a cold rolling oil composition having excellent surface gloss and uniformity of gloss.

[0007]

That is, the present invention is a cold rolling oil composition used as an emulsion emulsified and dispersed at a concentration of 1 to 20 wt% in water, which is selected from synthetic fatty acid esters. 0.5 to 20 wt% of thiophosphates and / or thiophosphites in one or more base oils
%, 3 to 20 wt% of glycol monoethers and 0.1 to 10 wt% of fatty acids, 100 wt% of rolling oil composition
The present invention relates to a cold rolling oil composition for a stainless steel strip, which is characterized by being added to.

In the cold rolling oil composition of the present invention, at least one selected from synthetic fatty acid esters is used as a base oil. As the synthetic fatty acid ester, conventionally known ones can be widely used, and examples thereof include stearic acid butyl ester, behenic acid 2-ethylhexyl ester, oleic acid neopentyl glycol ester, and isostearic acid trimethylolpropane ester.

As the thiophosphates used in the present invention, conventionally known ones can be widely used.
2-ethylhexyl thiophosphate, trilauryl thiophosphate, trioleyl thiophosphate, tristearyl thiophosphate, di-2-ethylhexyl thiophosphate, dilauryl thiophosphate, dioleyl dithiophosphate and the like can be mentioned.

As the thiophosphites used in the present invention, conventionally known ones can be widely used.
2-ethylhexyl trithiophosphite, trilauryl trithiophosphite, trioleyl trithiophosphite, tristearyl thiophosphite, tris (2
-Ethylhexyl-3-mercaptopropionate) phosphite, tris (lauryl-3-mercaptopropionate) phosphite and the like can be mentioned.

In the present invention, the above-mentioned thiophosphates and / or thiophosphites are added to the rolling oil composition 10 of the present invention.
0.5 to 20 wt% is added to 0 wt%. When the amount of the thiophosphates and / or thiophosphites added is less than 0.5 wt%, an extremely thin oil film cannot be retained in the boundary lubrication state, heat streak easily occurs, and the rolling oil emulsion adheres There is a drawback that it becomes non-uniform and uniform gloss cannot be obtained. On the other hand, on the contrary, 2
If it is more than 0 wt%, the viscosity of the composition of the present invention increases and the boundary lubrication state cannot be maintained, and as a result, the surface gloss decreases. In the present invention, it is particularly preferable to add 1 to 15 wt% of thiophosphates and / or thiophosphites to 100 wt% of the composition of the present invention.

As the glycol monoethers used in the present invention, conventionally known ones can be widely used. For example, the general formula R—O (A) _n H [wherein R is an alkyl group having 4 to 20 carbon atoms or An alkenyl group, A is an oxyalkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 3, respectively. ] The compound represented by these can be used effectively. Specific examples of the compound represented by the above general formula include propylene glycol monophenyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, and diethylene glycol monohexyl ether.

In the present invention, the above glycol monoethers are contained in an amount of 3 to 20 wt% based on 100 wt% of the composition of the present invention.
Added. The amount of glycol monoethers added is 3
If it is less than wt%, the detergency of the abrasion powder adhered to the steel strip or the work roll is deteriorated and the gloss becomes nonuniform. On the other hand, if it is more than 20 wt%, the viscosity of the composition of the present invention increases and the boundary lubrication state cannot be maintained, and as a result, the surface gloss decreases. In the present invention, it is particularly preferable to add 5 to 20 wt% of glycol monoethers to 100 wt% of the composition of the present invention.

The fatty acids used in the present invention include:
Conventionally known compounds can be widely used, and examples thereof include lauric acid, palmitic acid, stearic acid, oleic acid, isostearic acid, trimellitic acid, dimer acid and trimer acid.

In the present invention, 0.1 to 10 wt% of such fatty acids are added to 100 wt% of the rolling oil composition of the present invention. When the amount of the above fatty acids added is less than 0.1 wt%, an extremely thin oil film cannot be retained in the boundary lubrication state, heat streak is likely to occur, and the rolling oil emulsion is non-uniformly attached to give a uniform gloss. The drawback is that it cannot be obtained. On the other hand, on the contrary, when the content is more than 10 wt%
The viscosity of the composition of the present invention increases and the boundary lubrication state cannot be maintained, resulting in a decrease in surface gloss. In the present invention, especially fatty acids are added to the composition of the present invention 100w.
It is preferable to add 3 to 10 wt% with respect to t%.

In the composition of the present invention, one selected from the conventionally known anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants as emulsifiers. Alternatively, two or more kinds can be appropriately added. Further, if necessary, a phosphorus-based extreme pressure agent, a sulfur-based extreme pressure agent, an antioxidant, an oil burn inhibitor, etc. may be added to the composition of the present invention.

The viscosity of the composition of the present invention is not particularly limited, but is preferably 20 cst or less at 50 ° C.

In using the composition of the present invention, it is preferable to emulsify and disperse the composition of the present invention in water at a concentration of 1 to 20 wt% to form an emulsion, and use the emulsion by a usual method.

[0019]

INDUSTRIAL APPLICABILITY The cold rolling oil composition for a stainless steel strip of the present invention, when used in an emulsion state, has good lubricity and does not generate heat streak, and the product obtained has excellent surface gloss and It has a uniform gloss.

[0020]

EXAMPLES The present invention will be further clarified with reference to Examples and Comparative Examples below. In the following, "parts" simply means "parts by weight".

Example 1 Using 64 parts of stearic acid butyl ester and 15 parts of isostearic acid trimethylolpropane ester as a base oil,
To this, tris (2-ethylhexyl-3-mercaptopropionate) phosphite 10 parts, propylene glycol monophenyl ether 5 parts, dimer acid 3 parts, antioxidant (3,5-di-tert-butyl-4-hydroxy) Add 1 part of toluene, commonly known as BHT, and 1 part of emulsifier (polyoxyethylene nonylphenyl ether),
A rolling oil composition of the present invention was obtained. The viscosity (cst, 50 ° C.) of the obtained rolling oil composition was 15.8.

Examples 2 to 9 The components shown in Table 1 below were blended to obtain rolling oil compositions of the present invention. The viscosity of the obtained rolling oil composition (cst, 50
(° C) is also shown in Table 1.

[0023]

[Table 1]

Comparative Examples 10 to 16 The components shown in Table 2 below were blended to obtain rolling oil compositions. The viscosity (cst, 50 ° C.) of the obtained rolling oil composition is also shown in Table 2. In Table 2, commercially available mineral oil-based rolling oil (manufactured by Daido Chemical Industry Co., Ltd., 58 parts of mineral oil, 30 parts of synthetic ester, 2 parts of fatty acid, 1 part of antioxidant and 9 parts of emulsifier).
Part) and a commercially available beef tallow rolling oil (manufactured by Daido Chemical Industry Co., Ltd., beef tallow 92 parts, fatty acid 3 parts, extreme pressure additive 2 parts, antioxidant 1
Parts and 2 parts emulsifier) are also shown.

[0025]

[Table 2]

Example of use Using a two-stage cold rolling mill with a work roll diameter of 76 mm,
A 1 mm-thick SUS430 steel strip was cold-rolled in four passes. The rolling reduction of each pass was 20% for 1 to 3 passes and 30% for 4 passes. Rolling speed is 1 to 3 passes at 50mp
m and 4 passes were 300 mpm. In addition, No. 1 shown in Table 1 and Table 2. 1 to 18 of each composition at a concentration of 5%, 50
The emulsion was fed at a flow rate of 2 l / min. still,
The work roll roughness of each pass was set to an average roughness Ra of 0.1 μm.

As an evaluation of the heat streak prevention performance of the rolling oil composition, the rolling load of each pass was measured and the sum (Σ
Pt) divided by the product of the unit width b and the reduction amount Δh {ΣP
t / (b · Δh)} is calculated and the conventional beef tallow rolling oil (N
o. The relative ratio of the load of each rolling oil composition is shown based on the load of 18). The smaller this value, the better the heat streak prevention performance of the rolling oil composition.

As an evaluation of the surface gloss, the gloss and whiteness of the steel strip after 4-pass rolling were measured. Gloss is JIS Z
8741 The glossiness was measured under the conditions of measurement method 5 (GS20 °), and the whiteness was measured by the L value by a color difference meter. still,
The larger the value of gloss, the better the surface gloss, and the smaller the value of whiteness, the better the surface gloss.

In order to evaluate the uniformity of the surface gloss, the whiteness of the steel sheet rolled under the same conditions with the same rolling oil was measured at 20 points, and the standard deviation of the measured values was obtained.

The results are shown in Tables 3 and 4.

[0031]

[Table 3]

[0032]

[Table 4]

From Tables 3 and 4, the following can be seen. That is, the commercially available beef tallow rolling oil (No. 18) has a smaller rolling load relative ratio and is superior in heat streak performance as compared with other rolling oil compositions, but is significantly inferior in surface gloss and gloss uniformity. You can see that Further, it is understood that the commercially available mineral oil-based rolling oil (No. 17) is excellent in surface gloss and uniformity of gloss, but has a large rolling load relative ratio and is significantly inferior in heat streak prevention performance. Further, the comparative rolling oil composition (No. 10 to 16) contains a mineral oil or / and a fat and oil (No. 10 to 12), the synthetic fatty acid ester of the present invention as a base oil, and thiophosphates and / or It is roughly classified into the case where only one or two kinds of the group consisting of thiophosphites, glycol monoethers and fatty acids are contained (No. 13 to 16). Among these, No. It can be seen that the rolling load relative ratios of 10 to 14 are inferior to the commercially available beef tallow rolling oil and are inferior in heat streak preventive performance, and are inferior in surface gloss and gloss uniformity compared to the commercially available mineral oil rolling oil. In addition, No. 15 and N
o. No. 16 has a good surface gloss, but is significantly inferior in gloss uniformity and heat streak preventive performance.

On the other hand, the rolling oil composition (N
o. 1 to 9) have a rolling load relative ratio almost equal to that of a commercially available beef tallow rolling oil, have excellent heat streak prevention performance, and have surface gloss and gloss uniformity that exceed those of a commercially available mineral oil rolling oil. You can see that

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10M 129: 16 137: 10 129: 38 137: 02) C10N 20:02 30:00 40:24 ( 72) Inventor Eisuke Kawasumi 1st Kawasaki-cho, Chiba-shi, Chiba Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Takahiko Okamoto 1021, Kitamachi Kitamachi, Yamatokoriyama City, Nara Daido Chemical Industry Co., Ltd. ) Inventor Masasuke Tanaka 1021 Kitamachi Kitamachi, Yamatokoriyama City, Nara Daido Chemical Industry Co., Ltd.Nara Production Technology Office (72) Inventor Yoshio Yamashita 1021, Kitamachi, Yamatokoriyama City, Nara Daido Chemical Industry Co., Ltd. In-house (56) Reference JP-A-59-33395 (JP, A) JP-A-62-277495 (JP, A) JP-A-4-161495 (JP, A)

Claims (2)

(57) [Claims] 1. A cold rolling oil composition used as an emulsion emulsified and dispersed in water at a concentration of 1 to 20 wt%, wherein one or more base oils selected from synthetic fatty acid esters are added to thiophosphates. And / or thiophosphite 0.5 to 20 wt%, general formula: R—O (A) _n H [formula
Wherein R is an alkyl group or an alkenyl group having 4 to 20 carbon atoms
, A is an oxyalkylene group having 2 to 6 carbon atoms, and n is 1
The integers of 3 are shown respectively. ] 3-20 wt% of glycol monoethers and fatty acids of 0.1
A cold rolling oil composition for a stainless steel strip, wherein 10 wt% is added to 100 wt% of the rolling oil composition. 2. The rolling oil composition has a viscosity of 20 at 50.degree.
The cold rolling oil composition according to claim 1, which has a cst or less.