JP2736366B2 - Aqueous emulsion - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to novel aqueous emulsions,
The present invention relates to an aqueous emulsion useful as a hydraulic oil, a cutting oil, and the like.

Conventional technology Conventionally, mineral oil has been used as hydraulic oil or cutting oil.However, at high temperatures, there is a high risk of fire. Is being replaced.

However, these water-based hydraulic oils and cutting oils have a problem of inferior lubricity as compared with mineral oil-based oils. Therefore, water-based hydraulic oils and cutting oils are excellent in lubricity and have no danger of fire even when used at high temperatures. There is a strong demand for the development of hydraulic and cutting oils.

Problems to be Solved by the Invention Therefore, for example, an aqueous emulsion suitable for a cutting oil composed of a liquid ethylene / α-olefin copolymer, a surfactant and water has already been proposed.

As a result of further intensive studies on an aqueous emulsion containing such a liquid polymer, the present inventors have obtained an aqueous emulsion having even better lubricity and have reached the present invention.

Accordingly, an object of the present invention is to provide an aqueous emulsion which has excellent lubricity and is useful as a working oil and a cutting oil without danger of fire.

Means for Solving the Problems The aqueous emulsion according to the present invention comprises an ethylene component unit of 20 to 80 mol% and an α-
A liquid ethylene random copolymer composed of 80 to 20 mol% of olefin component units is oxidatively modified, and has a number average molecular weight of 500 to 10,000, an oxygen content of 1 to 20% by weight, an acid value of 1 to 50,
An oil-in-water aqueous solution comprising an oxidatively modified liquid α-olefin copolymer having a saponification value of 1 to 200, (b) a basic compound, (c) a nonionic surfactant, and (d) water. Emulsion.

The oxidatively modified liquid α-olefin copolymer used in the present invention is a liquid ethylene-based random copolymer comprising 20 to 80 mol% of ethylene component units and 80 to 20 mol% of α-olefin component units having 3 to 20 carbon atoms. The combined product is oxidatively modified, and has a number average molecular weight of 500 to 10,000, an oxygen content of 1 to 20% by weight, an acid value of 1 to 50 and a saponification value of 1 to 200.

Such an oxidatively modified liquid α-olefin copolymer is composed of 20 to 80 mol% of ethylene component units and 80 to 20 mol% of α-olefin component units having 3 to 20 carbon atoms, and has a number average molecular weight of 500 to 500 mol%. It can be obtained by oxidizing 10,000, preferably 800 to 5,000 liquid ethylene-based random copolymers with air and / or ozone while heating.

In the liquid ethylene-based random copolymer, as the α-olefin component unit having 3 to 20 carbon atoms, for example,
Propylene, 1-butene, 1-hexene, 4-methyl-
1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1
-Hexadecene, 1-octadecene, 1-eicosene and the like. In particular, according to the present invention, in the liquid ethylene-based random copolymer, the ethylene component unit is preferably from 30 to 70 mol%, most preferably from 40 to 70 mol%.
The α-olefin component unit is preferably in the range of 70 to 30 mol%, most preferably in the range of 60 to 40 mol%.

As already known, the liquid ethylene-based random copolymer is disclosed in JP-A-57-123205 and JP-A-61-22.
It can be obtained by the method described in Japanese Patent No. 1207. For example, it can be obtained by subjecting ethylene and α-olefin to Ziegler copolymerization using a Ziegler catalyst in the presence of hydrogen or by cationic polymerization. If necessary, the obtained polymer may be further hydrogenated or distilled.

In the present invention, the oxidatively modified liquid α-olefin copolymer has a number average molecular weight of 500 to 10,000, an oxygen content of 1 to 20% by weight, and an acid value of 1 for the purpose of obtaining a stable emulsion. ~ 50, saponification value is in the range of 1 ~ 200. Further, the oxidized liquid α-olefin copolymer preferably has a Q value (weight average molecular weight / number average molecular weight) of 4 or less, particularly preferably 3.5 or less.

When the number average molecular weight of the oxidatively modified liquid α-olefin copolymer is less than 500, the flash point is low, and when the aqueous emulsion is used as a working oil or cutting oil, a tough oil film is formed. Difficult to do. On the other hand, the number average molecular weight is
If it exceeds 10,000, it is difficult to form a stable aqueous emulsion.

In the present invention, as the basic compound, sodium hydroxide, alkali metal hydroxide such as potassium hydroxide, ammonia, mono-, di- or trialkylamine, for example, methylamine, dimethylamine, trimethylamine, Ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine,
Organic amines such as triethanolamine and morpholine are preferably used.

In these basic compounds and emulsions, the carboxyl groups and oxycarbonyl groups in the above-mentioned oxidatively modified liquid α-olefin copolymer are converted into a salt form to enhance the hydrophilicity of the polymer, The resulting emulsion is used to obtain a stable emulsion by adjusting the pH of the emulsion to 7 to 12, preferably 8 to 11.

The emulsion according to the invention further contains a nonionic surfactant. Examples of such a nonionic surfactant include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonylphenyl ether, and polyoxyethylene octylphenyl. Polyoxyethylene alkyl ethers such as ethers and polyoxyethylene alkyl aryl ethers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan fatty acid esters such as sorbitan monooleate, polyoxyethylene sorbitan monooleate Polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monopalmitate, polyoxyethylene glycol Laurate, may be mentioned polyoxyethylene glycol fatty acid esters such as polyoxyethylene glycol monostearate. These surfactants are used alone or as a mixture of two or more. Particularly, in the present invention, a surfactant having an HLB of 8 to 18, especially 10 to 16, is preferably used. However, polyoxyethylene / polyoxypropylene block copolymers are not suitable for use.

The aqueous emulsion according to the present invention comprises 10 to 90% by weight, preferably 20 to 50% by weight of the liquid α-olefin copolymer, based on the total weight of the oxidatively modified liquid α-olefin copolymer and water. %, And 90 to 10% by weight of water, preferably 80 to 50% by weight. Further, the nonionic surfactant is contained in an amount of 6 to 20 parts by weight per 100 parts by weight of the oxidatively modified polymer.

The aqueous emulsion according to the present invention is an oil-in-water emulsion and usually has a translucent to milky white color unless otherwise colored. The particle size of the emulsion is
Usually, it is about 0.01 to 3 μm, preferably about 0.01 to 1 μm.

The aqueous emulsion according to the present invention may contain various additives such as a rust preventive, a preservative, an extreme pressure agent, an oil agent, and an antifoaming agent, if necessary. Further, if necessary, for example,
It may be used by mixing with other aqueous emulsions such as minerals and glycols.

Effect of the Invention As described above, the aqueous emulsion according to the present invention comprises an oxidized modified liquid α-olefin copolymer having a predetermined number average molecular weight, oxygen content, acid value and saponification value, a basic compound, An oil-in-water type aqueous emulsion containing an ionic surfactant and water, having excellent lubricity,
Moreover, since there is no danger of fire, it is useful as hydraulic oil and cutting oil. However, the aqueous emulsion according to the present invention can be suitably used for metal working oils other than those described above, such as rolling oil, drawing oil, chip oil for aluminum die casting, and metal release agents.

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

In the examples, the method for evaluating the aqueous emulsion and the method for measuring the physical properties of the liquid α-olefin copolymer and its oxidized modified product are as follows.

(1) Average particle size of aqueous emulsion Measured at 23 ° C. using NICOMP MODEL 270 manufactured by HIAC / ROYCO.

(2) Aqueous emulsion friction coefficient Measured under the following conditions using an SRV friction tester manufactured by Optimol Corporation.

 Load 100N Amplitude 0.51mm Frequency 40Hz Temperature 37 ° C Time 30min (3) Depth of friction mark of water-based emulsion Measured by Surfcom 200B manufactured by Tokyo Seimitsu Co., Ltd.

(4) Aqueous emulsion viscosity was measured using an E-type viscometer manufactured by Tokyo Keiki Co., Ltd. under the following conditions.

Temperature 20 ° C. Rotation speed 10 rpm (5) α-Olefin copolymer composition Measured by ¹³ C-NMR.

(6) Number average molecular weight The number average molecular weight was measured using a vapor pressure osmometer (VPO) manufactured by KNAUER, using benzyl and squalane as standard samples of known molecular weight, under the conditions of a toluene solvent and 80 ° C.

(7) Q value It was measured under the following conditions according to Takeuchi's "Gel Permeation Chromatography" (published by Maruzen).

Equipment 150-ALC / GPC column manufactured by WATERS EIDu Pont de Nemours and Company (Zorbax type) Temperature 140 ° C Flow rate 1ml / min Standard sample Monodisperse polystyrene manufactured by Tosoh Corporation (8) Oxygen content By organic element analysis It was measured.

(9) Acid value It was measured according to the total acid value measurement method described in JIS K 2501-1980.

(10) Saponification value It was measured according to the saponification value measurement method described in JIS K 0070-1966.

Example 1 Ethylene component unit 49 mol%, number average molecular weight 1240, Q value
800 g of 1.74 liquid ethylene / propylene copolymer at 130 ° C
Then, dry air was blown into the mixture at a rate of 100 / hour for 10 hours with stirring to obtain an oxidized modified liquid copolymer.
This copolymer had a number average molecular weight of 1130, a Q value of 1.64, an oxygen content of 5.97% by weight, an acid value of 15.3 mgKOH / g, and a saponification value of 39.5 mgKOH.
/ g.

100 g of the above copolymer was placed in a glass reactor (operating capacity: 500 ml) equipped with a stirrer and a condenser, and 75 g of an aqueous potassium hydroxide solution (10 g KOH / 190 g distilled water) was added thereto, followed by sufficient stirring. Next, 10 g of HLB12.0 polyoxyethylene ralliuether (Emulgen 108 manufactured by Kao Corporation)
Was added and the temperature was raised to 80 ° C. while stirring. After stirring at 80 ° C. for 1 hour, 80 g of distilled water was added, and the mixture was further stirred for 15 minutes, and then cooled to room temperature to obtain an oil-in-water type aqueous emulsion.

The emulsion had a pH of 10, a viscosity (20 ° C) of 210 cps, and an average particle size of 0.05 µm.

Example 2 The procedure of Example 1 was repeated, except that 10 g of HLB 15.3 polyoxyethylene lauryl ether (Emulgen 120 manufactured by Kao Corporation) was used as the surfactant.
An oil-in-water aqueous emulsion was obtained.

The emulsion had a pH of 10, a viscosity (20 ° C) of 200 cps, and an average particle size of 0.04 µm.

Example 3 In Example 1, 5 g of polyoxyethylene lauryl ether of HLB 15.3 (Emulgen 120 manufactured by Kao Corporation) and polyoxyethylene lauryl ether of HLB 12.0 (Emulgen 108 manufactured by Kao Corporation) were used as surfactants. An oil-in-water type aqueous emulsion was obtained in the same manner as in Example 1 except that a mixture with 5 g was used.

The emulsion had a pH of 10, a viscosity (20 ° C) of 170 cps, and an average particle size of 0.04 µm.

Example 4 Ethylene component unit 54 mol%, number average molecular weight 3300, Q value
2.33 liquid ethylene / propylene copolymer 800 g at 170 ° C
Then, dry air was blown into this under stirring at a rate of 200 per hour for 17 hours to obtain an oxidized modified copolymer. This copolymer has a number average molecular weight of 3100, a Q value of 3.00, and an oxygen content.
The content was 7.86% by weight, the acid value was 24.6 mgKOH / g, and the saponification value was 55.3 mgKHO / g.

In the same manner as in Example 1, 44 g of potassium hydroxide aqueous solution (10 g KOH / 190 g distilled water), 5 g of polyoxyethylene lauryl ether of HLB 15.3 (Emulgen 120 manufactured by Kao Corporation), and HLB 12.0 were added to 100 g of the above copolymer. Of polyoxyethylene lauryl ether (Emulgen 108 manufactured by Kao Corporation) and distilled water 1
By adding 00 g, an oil-in-water type aqueous emulsion was obtained.

The emulsion had a pH of 8, a viscosity (20 ° C) of 270 cps, and an average particle size of 0.06 µm.

Example 5 In Example 3, instead of the aqueous potassium hydroxide solution,
An oil-in-water aqueous emulsion was obtained in the same manner as in Example 3 except that 3.4 g of morpholine and 150 g of distilled water were added.

The physical properties of the emulsion were pH 8, viscosity (20 ° C.) 50 cps, and average particle diameter 0.13 μm.

Comparative Example 1 In Example 1, when sodium dialkyl succinate (Pelex OT-P manufactured by Kao Corporation), which is an anionic surfactant, was used as the surfactant, the surfactant could be diluted with a large amount of distilled water. Therefore, an oil-in-water emulsion could not be obtained.

Comparative Example 2 In Example 1, when lauryltrimethylammonium chloride (Kaomin 24P manufactured by Kao Corporation), which is an anionic surfactant, was used as the surfactant, the surfactant could not be diluted with a large amount of distilled water. An oil-in-water emulsion could not be obtained.

Comparative Example 3 In Example 3, when the total amount of distilled water was 150 g without using an aqueous potassium hydroxide solution, the mixture was separated into two phases and an oil-in-water emulsion could not be obtained.

Next, in order to evaluate the lubricity of the aqueous emulsions obtained in Examples 3 and 4, the friction coefficient and the depth of wear marks were examined. The results are shown in Table 1.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10M 143: 18 129: 16 125: 10 145: 36 133: 50) C10N 10:02 20:04 40:08 40:22 60:04

Claims (3)

(57) [Claims] 1. A liquid ethylene random copolymer comprising (a) 20 to 80 mol% of an ethylene component unit and 80 to 20 mol% of an α-olefin component unit having 3 to 20 carbon atoms, which is oxidatively modified, (B) a basic compound, (c) an oxidized liquid α-olefin copolymer having a number average molecular weight of 500 to 10,000, an oxygen content of 1 to 20% by weight, an acid value of 1 to 50, and a saponification value of 1 to 200. An oil-in-water aqueous emulsion comprising: () a nonionic surfactant; and (d) water. 2. The oil-in-water aqueous emulsion according to claim 1, wherein the α-olefin is propylene. 3. The composition according to claim 1, further comprising 10 to 90% by weight of the copolymer and 90 to 10% by weight of water, based on the total weight of the oxidatively modified liquid α-olefin copolymer and water. The oil-in-water aqueous emulsion according to claim 1, which contains 6 to 20 parts by weight of a nonionic surfactant per 100 parts by weight of the polymer.