JP2010132870A - Lubricant composition for warm working of magnesium alloy and aluminum alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition for warm working of a magnesium alloy and aluminum alloy having an excellent processing load reducing property, scratch preventing property, low smoking property, burning resistance and degreasing property in calendaring and pressing working in a warm region of the magnesium alloy and aluminum alloy. <P>SOLUTION: 10-100 pts.wt. of a polyether compound synthesized from an alkyl glycidyl ether and a polyhydric alcohol or of an acetylated polyether compound obtained by acetylating the polyether compound is included in the compound when a total amount of the composition is 100 pts.wt. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention provides a lubricating performance that reduces the processing load in processing in the temperature region when plastic processing a magnesium alloy or an aluminum alloy, a low smoke generation performance that reduces smoke generation during processing, and a lubricant at a high temperature. The present invention relates to a lubricating oil that is excellent in anti-koge performance to suppress deterioration, and further has excellent degreasing properties after plastic working.

Magnesium alloys and difficult-to-work aluminum alloys are extremely poor in workability in a temperature region where there are few sliding surfaces at 180 ° C. or less, and are usually rolled or pressed in a warm region of 180 ° C. to 350 ° C.

As such a lubricant for magnesium and magnesium alloy, for example, Patent Document 1 has been proposed, but this lubricant is mainly composed of polyisobutylene and has a good stainability after rolling, but has a good fuming property. There is a problem, and high-strength press molding generates wrinkles that are insufficiently lubricated.

In addition, Patent Document 2 proposes to improve low smoke generation and kogation resistance by using a heat-resistant ester as a base, but it completely satisfies the required performance of low smoke generation and kogation resistance. In addition, the lubricating performance was insufficient, and it was insufficient as a lubricant for magnesium and magnesium alloy to be warm processed.

Furthermore, the silicone oil excellent in heat resistance proposed in Patent Document 3 has low smoke generation and good kogation resistance. However, silicone oil has a high coefficient of friction and is particularly poor in degreasing, so it has a problem in the subsequent process. Has occurred.

In addition, although the lubricating oil added with fluorine-based oil has a high coefficient of friction, it can satisfy the above-mentioned required performance from silicone oil including degreasing properties, but there are problems in terms of cost and environment. Therefore, magnesium and magnesium alloy warm, which has low smoke generation and scoring resistance equivalent to silicone oil base and fluorinated oil lubricants, lubrication performance to reduce processing load, and excellent degreasing after plastic processing Processing lubricants are eagerly desired.

JP 2006-131726 A JP 2004-323563 A JP 2003-253281 A

The object of the invention is the lubrication for warm working excellent in reduction of working load, prevention of wrinkles, low smoke generation, kogation resistance, and degreasing in rolling and pressing of magnesium alloy and aluminum alloy in the warm region. It is to provide an agent composition.

The applicant of the present application has previously filed an application for solving the above-mentioned problems (Japanese Patent Application No. 2007-209783). However, the present inventors have conducted extensive studies to solve the above-mentioned problems. An effective lubricant composition that can be applied to the warm working of magnesium alloys and aluminum alloys by finding that polyether compounds synthesized from ethers and polyhydric alcohols have excellent heat resistance and excellent kogation resistance. Found as a thing. In other words, because it has good heat resistance, there is little smoke generation, good lubricity during warm processing, and it evaporates after a certain time after processing, leaving no residue in the material or mold, It has been found that the lubricant composition also has good stain resistance. Furthermore, a synthetic ester, an extreme pressure agent, etc. were added, the lubricant composition which improved lubricity was discovered, and it came to complete this invention.

  That is, the lubricant for warm working of the magnesium alloy and aluminum alloy of the present invention is 10 to 100 parts by weight when a polyether compound synthesized from an alkyl glycidyl ether and a polyhydric alcohol is 100 parts by weight of the entire lubricant composition. It is characterized by containing.

The lubricant composition is characterized by containing 10 to 100 parts by weight of an acetylated polyether compound obtained by acetylating the OH group of the polyether compound when the lubricant composition is 100 parts by weight.

Furthermore, when the total amount of the lubricant composition is 100 parts by weight, 10 to 88.5 parts by weight of the polyether compound or acetylated polyether compound, 10 to 80 parts by weight of the synthetic ester, and one or more kinds of extreme pressure agents are included. 10 to 10 parts by weight, and 0.5 to 10 parts by weight of an antioxidant can further improve lubricity and deterioration resistance.

  Conventionally, there has been no lubricant that satisfies all the required performance related to reduction of processing load, prevention of wrinkles, low smoke generation, burn resistance, and degreasing properties. This problem can also be solved, and it is possible to process even shapes that have been difficult to form due to the difficulty of workability unique to magnesium alloys and aluminum alloys.

The present invention will be specifically described below.
In the present invention, at least one polyether compound synthesized from an alkyl glycidyl ether and a polyhydric alcohol is used as a base oil.

Specifically, one or two or more kinds of ether-bonded polyether compounds are used with respect to two or more hydroxyl groups of a polyhydric alcohol in which an alkyl glycidyl ether having 4 to 18 carbon atoms has a branched carbon chain. To synthesize. Examples of the polyhydric alcohol include polypropylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and the like. Examples of the alkyl glycidyl ether having 4 to 18 carbon atoms include butyl glycidyl ether, ethylhexyl glycidyl ether, decyl glycidyl ether, didecyl glycidyl ether, and tetradecyl glycidyl ether.

The polyether compound synthesized from the alkyl glycidyl ether and the polyhydric alcohol is less effective if it is less than 10 parts by weight, and 10 parts by weight or more is required.

Moreover, this invention uses the acetylated polyether compound which acetylated the OH group of the polyether compound synthesize | combined from the said alkyl glycidyl ether and a polyhydric alcohol as a base oil. Acetylation is carried out in the usual manner. For example, acetylation can be performed by reacting a polyether compound having an OH group with acetic anhydride in the presence of a catalyst (pyridine).

This acetylated polyether compound is less effective if it is less than 10 parts by weight, and 10 parts by weight or more is required.

The aforementioned polyether compounds and acetylated polyether compounds may be blended in combination of two or more.

(A) As a synthetic ester, a branched ester in which a linear or branched saturated fatty acid having 6 to 18 carbon atoms is bonded to two or more hydroxyl groups of a polyhydric alcohol having a branched carbon chain is 1 Use seeds or two or more. Examples of the polyhydric alcohol include neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol and the like. From the viewpoint of heat resistance, esters in which the hydrogen atom is not contained in the β-position carbon of the alcohol molecule are preferable. Examples of fatty acids include linear or branched caproic acid, caprylic acid, lauric acid, myristic acid, stearic acid, and the like.

This synthetic ester is preferably contained in 10 to 80 parts by weight.

Examples of (B) antioxidants include BHT (2,6-di-t-butyl-p-cresol) as a phenol-based antioxidant, and phenyl-β-naphthylamine as an amine-based antioxidant. Examples of the sulfur-based antioxidant include dilauryl thiodipropionate, and examples of the phosphorus-based antioxidant include tridecyl phosphite.

This antioxidant preferably contains 0.5 to 10 parts by weight of one or more kinds.

(C) Examples of extreme pressure agents include alkylphosphonic acids for phosphorus-based materials, sulfurized fats and oils, sulfurized olefins, sulfurized lard, polysulfide and the like for sulfur-based materials.

This extreme pressure agent preferably contains 1 to 10 parts by weight of one or more of phosphorus and sulfur.

As magnesium alloys and difficult-to-work aluminum alloys that are the subject of the present invention, those conventionally known are widely included, but representative examples include AZ-31, AZ-61, A-5052, and A-5083. A-6061, A-7072, A-7075, and the like.

In order to facilitate understanding of the present invention, examples and comparative examples are shown below.
The components shown in Table 1 were blended to adjust the compositions of Examples 1 to 9 and Comparative Examples 1 to 3, and a Bowden test and a thin plate forging test were performed.

<Bowden test = evaluation of lubricity and kogation resistance>
1. Test material:
Magnesium alloy AZ-31 (1x10x100mm)
Aluminum alloy A-5052 (1x15x100mm)
Test ball: SUJ-2 (3/16 inch φ)
Test temperature: 300 ° C, 250 ° C
Test load: 1kg
Speed: 3.88mm / s
Number of sliding times: 10 reciprocations (70mm / rot)
2. Test method:
A few drops of the sample were dropped on the test material, a steel ball was moved at a sliding speed of 3.88 [mm / s] under a load [N] of 1.0 kg, and the frictional force [F] was measured. The coefficient of friction μ is obtained from the following equation.
μ = [F] / [N]
3. Rating:
(1) Obtain the coefficient of friction from the above formula and confirm the lubrication performance of the test oil. In the evaluation method, a friction coefficient of 0.2 or less is denoted by ◎, a friction coefficient greater than 0.2 and 0.35 or less is denoted by ◯, and a friction coefficient greater than 0.35 is denoted by ×.
(2) Evaluate the kogation state on the surface of the test material after the test and confirm the kogation resistance.
If the test material after the test is burnt and there is no discoloration, `` ◎ '', although there is some discoloration,
Indicate “○” if there is no scoring, “×” if scoring is seen, and “△” if scoring is seen a little.

<Thin plate forging test = evaluation of formability, smoke generation, and kogation resistance>
1. Press machine: Komatsu servo press machine (H1F450)
2. Test material: AZ-31 (1.4 × 40 × 40 mm)
Mold material: SKD-61
Mold temperature: 300 ° C, 250 ° C
Test material heating time (with mold): 15 seconds Rolling ratio: 10-50%
3. Test method:
The test material is immersed in the test oil, and the test material to which the test oil is sufficiently adhered is placed on a 300 ° C. and 250 ° C. mold, heated for 15 seconds, and then press-molded at a predetermined reduction rate.
4). Rating:
(1) Molding was performed at a rolling reduction rate of 10 to 50%, and the molding was evaluated in terms of the maximum rolling reduction rate that could be molded into a predetermined shape and peeled well from the mold. 50% OK → ◎, 40% OK⇒ ○, 30% OK⇒ △, 20% OK⇒ ×
(2) If there is no smoke during the test, smoke ⇒ ◎, if it is very small, indicate ◯, if slightly more, indicate △, and indicate if it is severe.
(3) If the test material after the test is burnt and there is no discoloration, `` ◎ '', if there is a slight discoloration, but `` ○ '' if there is no burn, `` X '' if there is a burn, When a little is seen, “△” is written respectively.

  Tables 1 and 2 show the results of the Bowden tests of Examples 1 to 9 and Comparative Examples 1 to 3 when a magnesium alloy is used as the composition of the lubricant composition and the test material, and Table 3 shows the aluminum alloy as the test material. The result of the Bowden test of Examples 1-9 and Comparative Examples 1-3 when used is shown.

Table 4 shows the results of Examples 1 to 9 and Comparative Examples 1 to 3 of the thin plate forging test.

Polyether 1: A polyether compound synthesized from an alkyl glycidyl ether of general formula (2) and polypropylene glycol (R2 = mixed alkyl group having 12 and 14 carbon atoms, x = 1, y = 1, z = 4, GO = Oxypropylene group)
Polyether 2: Polyether compound synthesized from alkyl glycidyl ether of general formula (1) and neopentyl glycol (R1 = mixed alkyl group having 12 and 14 carbon atoms, l = 4, m = 4, A = methyl group , B = methyl group)
Polyether 3: A polyether compound synthesized from alkyl glycidyl ether of general formula (1) and trimethylolpropane (R1 = mixed alkyl group having 12 and 14 carbon atoms, l = 1, m = 1, A = ethyl group) , B = group—CH ₂ O (CH ₂ CH (OH) CH ₂ OR1) n, n = 1)
Acetylated polyether 4: An acetylated polyether compound obtained by acetylating a polyether compound synthesized from an alkyl glycidyl ether of the general formula (3) and neopentyl glycol (R1 = C4 alkyl group, l = 1, m = 1, A = CH3, B = CH3)
Acetylated polyether 5: An acetylated polyether compound obtained by acetylating a polyether compound synthesized from an alkyl glycidyl ether of the general formula (4) and polyethylene glycol (R2 = C4 alkyl group, x + y = 1, z = 2, GO = oxyethylene group)
・ Synthetic ester A: Pentaerythritol fatty acid ester (manufactured by NOF H-4810BR-32)
Synthetic ester B: Pentaerythritol fatty acid diester (HR-200, NOF Corporation)
Palm oil: (Fuji Oil PM-A-10)
Antioxidant J: 4,4′-thiobis (6-tertiarybutyl-3-methylphenol) (Sumitomo Chemical Sumitizer WX-R)
・ Antioxidant K: Bisphenol compound (Sumitomo GA80 manufactured by Sumitomo Chemical)
-Extreme pressure agent P: Phosphorus extreme pressure agent (Daido Chemical Alkylphosphonic acid diisopropyl ester)
・ Silicone oil: Dimethyl silicone oil (Shin-Etsu Chemical Silicon KF-96)

The following can be understood from Tables 1 to 4.

(1) The results of Examples 1 to 9 at 300 ° C. confirmed that the moldability was good and the kogation resistance was good compared to Comparative Examples 1 to 3 in any case. In Examples 1 to 9, the smoke generation is also very small, and it is judged that there is no problem in the working environment at the time of actual press molding at 300 ° C.
(2) Comparative Example 1 has poor smoke generation and kogation resistance and is not very good in moldability.
(3) Comparative Example 2 in which an antioxidant and an extreme pressure agent are added to the synthetic ester has relatively good lubricity (friction coefficient), but is inferior in moldability, and has poor smoke generation and kogation resistance.
(4) The silicone oil of Comparative Example 3 is good in smoke generation and kogation resistance, but has a poor lubricity (coefficient of friction) and a problem because the silicon film remains after molding.
(5) At 300 ° C., Examples 1 to 9 all had good friction coefficients and moldability.
(6) The results of Examples 6 to 9 confirmed that the kogation resistance at 250 ° C. was good.
(7) Both 300 ° C. and 250 ° C. have good Bowen friction coefficient and formability in the forging test in Examples 1 to 9, and are considered to have good lubricity.

Claims (3)

10 to 100 parts by weight of a polyether compound synthesized from an alkyl glycidyl ether represented by the general formula (1) or (2) and a polyhydric alcohol when the total composition is 100 parts by weight A lubricant composition for warm working of magnesium alloys and aluminum alloys.

(Wherein A and B are groups —CH ₃ , —C ₂ H ₅ , or groups —CH ₂ O (CH ₂ CH (OH) CH ₂ OR1) n, —CH ₂ O (CH ₂ CH (OH) CH indicates ₂ OR1) o, R1 represents a hydrocarbon group having 4 to 18 carbon atoms, showing l, m, n, o is an integer from 1 to 10.)

(In the formula, GO represents an oxyethylene group, an oxypropylene group or an oxybutylene group, R2 represents a hydrocarbon group having 4 to 18 carbon atoms, x and y represent an integer of 1 to 10, and z represents 1 to Indicates an integer of 30.) When the total composition is 100 parts by weight, the acetyl represented by the general formula (3) or (4) obtained by acetylating the OH group in the polyether compound represented by the general formula (1) or (2) A lubricant composition for warm working of magnesium alloys and aluminum alloys, characterized by having 10 to 100 parts by weight of a modified polyether compound.

(Wherein A and B are groups —CH ₃ , —C ₂ H ₅ , or groups —CH ₂ O (CH ₂ CH (OH) CH ₂ OR1) n, —CH ₂ O (CH ₂ CH (OH) CH indicates ₂ OR1) o, R1 represents a hydrocarbon group having 4 to 18 carbon atoms, showing l, m, n, o is an integer from 1 to 10.)

(In the formula, GO represents an oxyethylene group, an oxypropylene group or an oxybutylene group, R2 represents a hydrocarbon group having 4 to 18 carbon atoms, x + y represents an integer of 1 to 20, and z represents 1 to 30. Indicates an integer.)
When the total composition is 100 parts by weight, either a polyether compound represented by general formula (1) or (2) or an acetylated polyether compound represented by general formula (3) or (4) Or 10-88.5 parts by weight in combination of two or more, (A) 10-80 parts by weight of synthetic ester, (B) 0.5-10 parts by weight of one or more antioxidants and / or ( C) Lubricant composition for warm working of magnesium alloy and aluminum alloy containing 1 to 10 parts by weight of one or more extreme pressure additives.