An additive to metal cold rolling oil

Abstract

 This invention relates to a cold rolling oil additive and an emulsion type cold rolling oil composition. The additive according to the invention is a compound obtainable by reacting at least one member of polyalkylenepolyamines and polyalkyleneimines each containing 3 to 200 N atoms with at least one member of fatty acid compounds, glycidyl ether com­pounds and epoxy compounds. With this additive, cold rolling oil compositions having excellent lubricating and stable circulation characteristics can be easily obtained.

Description

BACKGROUND OF THE INVENTION

[0001] This invention relates to a cold rolling oil additive and an emulsion type cold rolling oil composi­tion containing said additive.

[0002] The cold rolling oil in prevalent use today is generally based on, as the lubricating oil component, an animal or vegetable oil, a mineral oil, a fatty acid ester or the like and contains, as supplemental compo­nents, a rust inhibitor, high-pressure agent, oil improving agent, antioxidant, antifoam and/or other auxiliary agents. Such cold rolling oil is emulsified with an emulsifying agent into an O/W emulsion, which is then fed to the roll assembly of the mill generally at a concentration of about 1 to 20 percent. On the other hand, with the recent advance of rolling techn­ology, high-speed rolling and mas production have been implemented and there is consequently a demand for rolling oil with improved lubricating property, work­ability and amenability to effluent disposal.

[0003] Under the circumstances, the prior art cold rolling oil incorporating the conventional emulsifier controls rolling lubricity by adjusting the type and addition level of emulsifier to thereby increase or decrease the quantity of oil (plateout) that will be deposited on the surface of rolling work, with the result that the amount of plateout and the stability of the circulating emulsion cannot be reconciled. Stated differently, the higher the stability of the emulsion, the smaller is the amount of plateout on the rolling work, thus leading to an insufficiency of lubrication. On the other hand, if it is attempted to increase the amount of plateout, the stability of the emulsion is sacrificed so that various troubles are encountered while the emulsion is circulated. Furthermore, the iron particles produced in the course of cold reduction find their way into this unstable emulsion so that scums tend to be attached to the cold-rolled steel plate to adversely affect the subsequent washing and annealing processes. Furthermore, the scums attach themselves to the rolls and the equipment around the rolls to jeopardize the work environment and interfere with workability. To overcome these disadvantages, a variety of cold rolling oil compositions have been proposed (for example, Japanese Patent Publication No. 62-14599 and Japanese Kokai Patent Publication No. 62-121792). However, these compositions are invariably deficient in annealing process antifouling performance and in the assurance of cleanliness of the rolling mill equipment, thus being of no great field utility.

SUMMARY OF THE INVENTION

[0004] It is an object of this invention to provide a cold rolling oil composition which has excellent lubricating capability, emulsion stability and anneal­ing process antifouling property and assures the utmost cleanliness of rolling mill equipment.

[0005] It is another object of this invention to provide an additive for use as an active component of said metal cold rolling oil composition.

[0006] This invention relates, in one aspect, to a cold rolling oil additive which is a compound obtainable by reacting at least one member of the group consisting of polyalkylenepolyamines and polyalkyleneimines each containing 3 to 200 nitrogen atoms with at least one member of the group consisting of fatty acid compounds, glycidyl ether compounds and epoxy compounds and, in another aspect, to a cold rolling oil composition containing the same additive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The polyalkylenepolyamines which can be used in accordance with this invention include, among others, diethylenetriamine, triethylenetetramine, tetraethyl­enepentamine, pentaethylenehexamine, dipropylenetri­ amine and tetrapropylenepentamine. The polyalkylene­imines include polyethyleneimine, polypropyleneimine and so on.

[0008] The fatty acid compounds which react with the active hydrogen atoms of such polyalkylenepolyamines and polyalkyleneimines include, among others, higher fatty acids containing 8 to 22 carbon atoms, such as 2-ethylhexylic acid, lauric acid, stearic acid, coconut oil fatty acid, beef tallow fatty acid, oleic acid, linoleic acid, etc., and dimer and polymer acids of unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid and so on.

[0009] The glycidyl ether compounds which react with the active hydrogen atoms of said polyalkylenepolyamines and polyalkyleneimines include, among others, the glycidyl ethers of aliphatic alcohols or alkyl phenols, such as octyl alcohol glycidyl ether, lauryl alcohol glycidyl ether, stearyl alcohol glycidyl ether, nonyl­phenol glycidyl ether, dodecylphenol glycidyl ether, and so on.

[0010] The epoxy compounds include, among others, C₈₋₂₆ aliphatic α-olefin epoxides, C₈₋₂₂ cycloolefin epoxides and C₈₋₂₀ alkyl diepoxides and so on.

[0011] The metal cold rolling oil additive of this invention is a compound obtainable by reacting at least one member selected from the group consisting of the aforementioned polyalkylenepolyamines and polyalkylene­imines each containing 3 to 200 nitrogen atoms with at least one member selected from the group consisting of the aforementioned fatty acid compounds, glycidyl ether compounds and epoxy compounds, and functions as a basic surface active agent.

[0012] In the practice of this invention, the aforesaid basic compound may be used alone but is preferably used in combination with an acidic surface active agent such as phosphoric acid ester compounds, sulfonic acid compounds, sulfonic acid ester compounds and so on, in the form of a neutral salt at pH 3 to 10.

[0013] The phosphoric acid ester compounds mentioned above include, among others, the compounds obtainable by reacting 2 to 5 moles of the adduct of 1 to 30 moles of ethylene oxide to an alkylphenol such as butyl-­phenol, nonylphenol, dodecylphenol, etc., or a higher alcohol such as octyl alcohol, lauryl alcohol, oleyl alcohol, etc. with 1 mole of phosphoric anhydride generally at a temperature of 30 to 90°C or the com­pounds obtainable by reacting 2 to 5 moles of the block or random adduct of 1 to 10 moles of propylene oxide and 1 to 30 moles of ethylene oxide to said alkylphenol or higher alcohol with 1 mole of phosphoric anhydride generally at a temperature of 30 to 90°C.

[0014] As examples of said sulfonic acid compounds or sulfonic acid ester compounds, there may be mentioned the compounds obtainable by reacting 1 to 2 moles of an alkylbenzene containing 6 to 24 carbon atoms, an α-olefin containing 8 to 26 carbon atoms, an alkyl­phenol containing 6 to 24 carbon atoms, a higher alcohol containing 6 to 22 carbon atoms, or an alkyl­phenol or higher alcohol-alkylene oxide adduct with 1 mole of a sulfonating agent such as sulfuric acid, fuming sulfuric acid, sulfuric anhydride, chloro­sulfonic acid, sulfamic acid, etc. at a temperature from 10 to 120°C. As examples of said alkylphenol or higher alcohol-alkylene oxide adduct, there may be mentioned the block or random adduct obtainable by adding 1 to 30 moles of ethylene oxide or 1 to 10 moles of propylene oxide plus 1 to 30 moles of ethylene oxide.

[0015] The basic compound and neutral salt thereof, which constitutes the cold rolling oil additive of this invention, can be synthesized in any known manner. For example, they can be produced by the following method. To tetraethylenepentamine (which contains 5 nitrogen atoms) is added stearic acid and the mixture is subject­ed to condensation with elimination of water at an elevated temperature of 120 to 180°C to give an amide compound. To this is added polyoxyethylene nonylphenol ether phosphate or sulfonate at a temperature of 30 to 100°C to give a neutral salt with pH 7.

[0016] Furthermore, the additive according to this invention preferably contains a nonionic surface active agent with a HLB number of not less than 6. As examples of such nonionic surfactant, there may be mentioned the adducts of ethylene oxide, propylene oxide, butylene oxide or the like to C₈₋₂₂ alcohols, alkylphenols, fatty acids or polyhydric alcohol fatty acid esters. If the HLB number is less than 6, the stability of the emulsion is unsatisfactory and the incidence of oil stain increases. The above-mentioned C₈₋₂₂ alcohols include octyl alcohol, lauryl alcohol, stearyl alcohol, oleyl alcohol and so on. The alkylphenols include, among others, butylphenol, octylphenol, nonylphenol, dodecylphenol, etc. and the corresponding condensates with formaldehyde. The fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and so on. The polyhydric alcohol fatty acid esters include, among others, the esters obtainable by reacting said fatty acids with glycerol, polyglycerol, pentaerythritol, sorbitol, ethylene glycol, propylene glycol or the like.

[0017] The cold rolling oil composition of this invention comprises the above-described additive and a lubricat­ing oil component. As this lubricating oil component, any of the components heretofore in use as this type of rolling oil can be employed. As examples of such components, there may be mentioned animal oils, vege­table oils, mineral oils, and synthetic fatty acid esters. These oil components can be used singly or in combination. To be specific, there may be used any of mineral oils such as spindle oil, machine oil, turbine oil, cylinder oil etc.; animal and vegetable oils such as sperm oil, beef tallow, lard, rapeseed oil, castor oil, rice bran oil, soybean oil, palm oil, coconut oil, etc.; esters of fatty acids from beef tallow, coconut oil, castor oil, etc. with aliphatic monohydric alcohols containing 1 to 22 carbon atoms; and fatty acid esters synthesized from such fatty acids and polyhydric alcohols such as propylene glycol, pentaerythritol, sorbitol and so on.

[0018] Generally, the rolling oil composition is based on an animal or vegetable oil, a mineral oil or a synthe­tic fatty acid ester and, if required, contains as a supplemental component one or more members of the group consisting of oil improving agents, high-pressure additives, rust inhibitors, antioxidants, emulsifiers, antifoams, etc. and is used as diluted with water into an emulsion of 0.1 to 10% concentration. The cold rolling oil composition of this invention can also be used in the same manner. Thus, the additive of this invention is first dissolved in a base oil component and, then, diluted with water to form an emulsion. Alternatively, the additive of this invention may be first dissolved in water and then emulsified with the base oil component to form an emulsion. The level of addition of the additive of this invention based on the total weight of the cold rolling oil composition is 0.1 to 10 percent by weight and preferably 0.5 to 5 percent by weight.

[0019] In addition to the above components, the cold rolling oil composition of this invention may further contain, as required, any of the known oil improving agents, high-pressure additives, rust inhibitors, antioxidants, defoamers and so on.

[0020] Since, in the cold rolling oil composition, the protective colloid action of the additive of this invention allows the lubricating oil to be stably dispersed in water as fairly large particles, the oil component maintains a stable and fairly large particle size distribution even under agitated conditions with high shearing forces in the tank, circulating pump and so on.

[0021] Moreover, since the large oil particles form a thick lubricating film on the metal work upon supply to the roll, the composition exhibits an excellent cold roll lubricating performance and insures a satisfactory circulation stability (the large particle size of oil is retained and no separation of the oil occurs even if the composition is recycled).

[0022] Furthermore, when the neutral salt of a basic surfactant and an acidic surfactant is employed, its ability to become quickly adsorbed on the liquid and solid particles to render them hydrophilic helps eliminate the entrapping of infiltrating dirty oil or contaminents such as metal dust during the rolling operation and prevent fouling of the tank and mill line. These effects are not obtained with the con­ventional rolling oil compositions prepared using the ordinary emulsifiers. As a consequence, the com­position of this invention has a laudable feature that it helps insure a clean environment which has never been achieved with the conventional cold rolling oil emulsions. Furthermore, since the rolling oil com­position of this invention retains a stable cold-roll lubricating property, it is by far superior to the commercial rolling oil compositions heretofore avail­ able in lubricating performance and clean mill character­istic.

[0023] Providing, thus, a cold rolling oil composition having excellent cold-roll lubricating and stable recycling characteristics, this invention contributes a great deal to the progress of rolling technology.

[0024] The following examples and comparative examples are merely illustrative of this invention and should by no means be construed as limiting the scope of the invention.

[0025] The additives A through T according to this invention, which are to be incorporated in rolling oil compositions are shown in Tables 1 and 2. The rolling oil compositions of this invention, which were prepared by using these additives in predetermined proportions (by weight), are shown in Tables 3 and 4.

[0026] The performance of these rolling oil compositions was evaluated by the following tests. The results are set forth in Tables 5 and 6.

(1) Lubrication test

[0027] Using a Timken tester, the test was performed in accordance with JIS K 2519. Thus, in a tank, each rolling oil composition was diluted with water to a concentration of 5% and stirred by means of a homomixer at 8000 rpm to provide a dispersion at a temperature of 60°C and this dispersion was fed for circulation. The evaluation was made on the basis of the specific area within the seizure limit curves. The poorest rating was 1.0 (ratio). The larger this ratio, the more desirable is the lubricating property.

(2) Annealing process antifouling test

[0028] To a 5% aqueous dispersion of each rolling oil composition was added 0.1% of iron power (particle size: not more than 1 µm) to provide a rolling oil dispersion at 60°C. Using a gear pump, this rolling oil dispersion was sprayed from a nozzle against the surface of a test steel plate (0.5 ℓ/min., 1 atm., 5 seconds) and dried. Two steel plates similarly treated were laid one on the other, pressed together at a pressure of 40 kg/cm² and heated at 130°C for 15 hours. Then, the assembly was annealed in an atmos­phere of N₂ + 5%H₂ gas in an annealing furnace at 700°C for 2 hours and the degree of fouling of the surface of the steel plates was visually evaluated and rated according to the following criteria.
ⓞ: neat condition without deposits
o: neat condition, although slight deposits are found
x: poor condition with much deposits

(3) Dispersion stability test

[0029] 

[0030] To a 5% aqueous dispersion of each rolling oil composition was added 0.1% of iron powder (particle size: not more than 1 µm) to provide a rolling oil dispersion at 60°C. Using a gear pump, this dispersion was continuously sprayed at a pressure of 2.5 kg/cm² against an iron roll heated to 150°C in a closed liquid circuit. After 48 hours, the oil fraction of the dispersion, to the exclusion of the surface floating oil phase, was quantitated and the percent decrease from the initial concentration was determined by means of the following equation.
% Decrease = [(initial concentration - final concentration)/initial concentration] x 100

(4) Effluent disposability test

[0031] To the rolling oil dispersion prepared in the above test (1) was added 3 g of aluminum sulfate and the mixture was stirred for 2 minutes. After adjust­ment to pH 7.0 with Ca(OH)₂, the mixture was further stirred for 10 minutes and, then, allowed to stand for 30 minutes. The surface oil phase was discarded and the clear liquid was recovered and tested for COD (chemical oxygen demand, KMnO₄ method).

Table 5

	Lubricating property	Antifouling performance in annealing step	Stability of dispersion (%)	COD (ppm)
Example
1	2.75	ⓞ	5	250
2	2.45	ⓞ	6	320
3	2.50	ⓞ	8	240
4	2.70	o	11	120
5	2.40	o	14	145
6	2.65	o	12	130
7	2.70	ⓞ	4	220
8	2.80	ⓞ	3	255
9	2.65	o	7	160
10	2.50	o	6	265
11	2.60	ⓞ	5	195
12	2.75	o	4	230
13	2.65	o	8	180
14	2.50	o	10	210

Table 6

	Lubricating property	Antifouling performance in annealing step	Stability of dispersion (%)	COD (ppm)
Example
15	2.30	ⓞ	8	280
16	2.60	ⓞ	4	220
17	2.70	ⓞ	7	150
18	2.45	o	13	270
19	2.55	o	10	235
20	2.75	o	15	210
21	2.40	ⓞ	6	185
22	2.90	ⓞ	3	190
23	2.85	ⓞ	5	230
24	2.65	ⓞ	9	270
25	2.50	ⓞ	4	175
26	2.80	ⓞ	8	140

Comparative Example
1	1.90	x	31	2800
2	1.85	x	35	2520
3	1.70	x	36	2210

[0032] It will be apparent from Tables 5 and 6 that the cold rolling oil composition of this invention is superior to the conventional composition (Comparative Examples) in all of lubricating property, annealing process antifouling performance, dispersion stability and effluent disposability.

Claims

1. A cold rolling oil additive which is a compound obtainable by reacting at least one member selected from the group consisting of polyalkylenepolyamines and polyalkyleneimines each containing 3 to 200 nitrogen atoms with at least one member selected from the group consisting of fatty acid compounds, glycidyl ether compounds and epoxy compounds.

2. A cold rolling oil additive according to Claim 1 wherein said fatty acid compound is at least one member selected from the group consisting of higher fatty acids containing 8 to 22 carbon atoms, dimer acids of unsaturated fatty acids, and polymer acids of unsaturated fatty acids.

3. A cold rolling oil additive according to claim 1 or 2, wherein said glycidyl ether compound is at least one member selected from the group consisting of aliphatic alcohol glycidyl ethers and alkylphenol glycidyl ethers.

4. A cold rolling oil additive according to claim 1 or 2, wherein said epoxy compound is at least one member selected from the group consisting of aliphatic α-olefin epoxides containing 8 to 26 carbon atoms, cycloolefin epoxides containing 8 to 22 carbon atoms and alkyl diepoxides containing 8 to 20 carbon atoms.

5. A cold rolling oil additive according to any of the claims 1 to 4 which further contains an acidic surface active component.

6. A cold rolling oil additive according to Claim 5 wherein said acidic surface active component is at least one member selected from the group consisting of phosphoric acid ester compounds, sulfonic acid compounds and sulfonic acid ester compounds.

7. A cold rolling oil additive according to any of the claims 1 to 4, which further contains a nonionic surface active component with a HLB number of not less than 6.

8. A cold rolling oil additive according to claim 5 or 6, which further contains a nonionic surface active component with a HLB number of not less than 6.

9. A cold rolling oil composition comprising the cold rolling oil additive of any of the claims 1 to 8 and a lubricating oil component.

10. A cold rolling oil composition according to Claim 9 wherein said lubricating oil component is at least one member selected from the group consisting of animal and vegetable oils and fats, mineral oils and synthetic fatty acid esters.