JPH08143735A - Resin composition and solid lubricant composition containing the same and used for drawing metal material - Google Patents

Abstract

PURPOSE: To obtain a resin composition desirable as a solid lubricant which forms a dense, tough and solid lubricant film and used for drawing a metal material. CONSTITUTION: This resin compositions comprises a powder prepared by melt- blending a low trifluorochloroethylene polymer and a high trifluorochloroethylene polymer in a ratio of the low polymer to the high polymer of 95/5 to 30/70 by weight and grinding the blend and optionally blending a metal soap or an alkali soap. When this lubricant is used, no heat fusion among particles of the lubricant occurs and therefore extreme pressure lubricating properties can be attained during drawing a metal material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid lubricant composition used in drawing a metal material.

[0002]

2. Description of the Related Art Metal wires, rods, tubes, etc. are manufactured by drawing metal materials with a die or the like.
At this time, a liquid pretreatment agent is applied, and then a die is filled with an appropriate liquid lubricant or solid lubricant to perform drawing.

As the solid lubricant for the drawing process, for example, metal soap, alkali soap, etc. are used, and as the liquid lubricant, for example, trifluorochloroethylene low polymer (melting point: about 50 to 90 ° C.). , Number average molecular weight:
It is known that about 1100 to 2000) is added to an organic solvent (Japanese Patent Publication No. 57-2405).

[0004]

When using a liquid lubricant, when using an organic solvent such as benzene, there is a risk of fire, and when using a chlorine-based solvent such as trichlorethylene, be careful of toxicity. However, there is a problem in terms of equipment and work environment.

Further, solid lubricants such as metal soaps and alkali soaps are inferior in baking load and die life, and are still insufficient as solid lubricants for metal drawing.

The trifluorochloroethylene low polymer used as an additive for liquid lubricants not only has extremely excellent extreme pressure lubricity but also has a low melting point, so that it is subjected to extreme pressure reduction during drawing. Rapidly forms an oil film, forms a wax-like smooth film even when solidified after wire drawing, and has good adhesion to metal. However, since the melting point of ethylene trifluoride chloride low polymer is close to the ambient temperature at the time of drawing, when used alone, the powders fuse together in the die box, and as a result, the surface of the metal material to be processed becomes The phenomenon that the sufficient contact is not maintained (due to the so-called tunnel effect) and is not supplied to the surface occurs. for that reason,
Conventionally, an organic solvent has been used as a liquid lubricant, but as described above, there are problems in terms of equipment and working environment.

The object of the present invention is to provide a solid lubricant which does not cause heat fusion during metal drawing or storage, has an excellent lubricating effect, and is capable of forming a dense and tough lubricant film. It is intended to provide a composition and a solid lubricant for drawing a metallic material using the composition. Since the solid lubricant of the present invention has excellent lubricity and excellent ability to form a lubricating coating on metal, it is possible to omit the conventional coating step of the liquid pretreatment agent.

The inventors of the present invention have conducted various studies to eliminate the drawbacks of the low polymerization product of trifluoroethylene chloride, and the powder obtained by melt-mixing with the high polymerization product of trifluoroethylene chloride has a melting starting temperature. Surprisingly, the melting point of the low-polymerized ethylene trifluoride chloride was significantly higher, and it was found that the fusion of the powders can be suppressed. The melting start temperature of the melt-mixed powder is higher than the melting point of the low polymer and lower than the melting point of the high polymer. Although the reason for this is not clear, such a drastic change in the melting start temperature is not observed by simply mixing the powders.

[0009]

Means for Solving the Problems That is, the present invention provides a solid lubrication for drawing a metal material containing a powder obtained by melt-mixing and pulverizing a trifluorochloroethylene low polymer and a trifluoroethylene high polymer. The present invention relates to a resin composition suitable as an agent.

The low-polymerized trifluoroethylene chloride used in the present invention is a wax which is solid at room temperature and has a number average molecular weight of about 1100 to 3000, preferably 1300 to 3000.
The melting point is about 45-90 ° C, preferably 50-90 ° C. As such a trifluoroethylene chloride low polymer, for example, a trifluoroethylene chloride low polymer conventionally used for a liquid lubricant can be used.

A preferred high polymer of trifluorochloroethylene has a zero strength time (ZST) of about 200.
~ 450 seconds, preferably 200-270 seconds, which is about 210-230 ° C, preferably 212.
It has a melting point of ˜217 ° C. In addition, Z. S. T
Is an abbreviation for Zero strength time (strength disappearance time) and is used as a simple measure of the molecular weight of a highly polymerized ethylene trifluorochloride. 2 "(inch) in length,
1 "from the bottom edge of a test piece with a width of 3/16" and a thickness of 1/16 "
It is represented by the time (in seconds) until cutting when a right-angled notch having a width of 3/64 "is cut at that position, 7.5 g of weight is attached to the lower end, and the product is held in a furnace at 250 ° C.
Z. S. T. The logarithm of is almost proportional to the molecular weight.

The melt mixture powder is produced, for example, by powdering a trifluoroethylene chloride low polymer (hereinafter sometimes referred to simply as "low polymer") and a trifluoroethylene chloride high polymer (hereinafter simply referred to as "high polymer"). (Also referred to as a "polymer") may be sufficiently mixed, heated to a temperature higher than the melting point of the high polymer, melt-mixed, cooled and solidified, and then pulverized.

The particle size of the low polymerized product powder and the high polymerized product powder is not particularly limited, but both are preferably about 500 μm or less, and more preferably about 10 μm or more from the viewpoint of melt mixing.

Mixing is carried out below the melting point of the low polymer, usually 20 to 3
It is preferably carried out at 5 ° C. using, for example, a V type blender.

The melting by heating is carried out at a temperature not lower than the melting point of the high polymer, preferably at 260 to 290 ° C., using a kneader or the like, and is sufficiently mixed at the time of melting.

After melt mixing, the mixture is cooled and the solidified product is crushed. The particle size is preferably about 2 mm or less, and the lower limit is preferably about 10 μm.

The melting start temperature of the molten mixture powder changes depending on the mixing ratio of the low polymer and the high polymer, and becomes higher as the amount of the high polymer increases. However, when the proportion of the high polymer is high, the melting and mixing requires a relatively long time at a high temperature, so that the decomposition is increased, and as a result, the melting start temperature of the molten mixture powder is lowered. Therefore, the mixing ratio of the low-polymerized product and the high-polymerized product is mainly the desired lubricity, ease of melt mixing, etc.
It may be determined in consideration of the melting start temperature of the molten mixture powder. Usually, the weight ratio of low polymer / high polymer is 95/5 to 3
It is 0/70, preferably 95/5 to 50/50, and particularly preferably 95/5 to 80/20.

Other solid lubricants, extreme pressure additives, rust preventives and the like may be added to the lubricant composition of the present invention.

Other solid lubricants include, for example, metal soap, alkali soap, and the like. Among them, metal stearates such as calcium stearate and barium stearate, and alkalis such as lithium stearate and sodium stearate. Soken is preferred. These other solid lubricants need only be mixed with the molten mixture powder.
By adding metal soap and alkali soap, the lubricating effect of the metal soap itself and the viscosity of the oil film under extreme pressure increase, making it difficult for the oil film to break even under high load, so the extreme pressure lubricity is greatly improved. Improve to. The amount of the other solid lubricant to be blended is usually about 1000 parts or less, preferably 30 to 300 parts, particularly preferably 80 to 120 per 100 parts (parts by weight, the same below) of the trifluoroethylene chloride molten mixture powder.
It is a department. The particle size is preferably about 500 μm or less.

Examples of the extreme pressure additive include molybdenum disulfide, graphite, carbon fluoride and the like.
About 100 parts or less can be added per 100 parts of the trifluoroethylene chloride molten mixture powder.

Examples of the rust preventive agent include calcium oxide, calcium hydroxide, barium hydroxide, calcium carbonate, sodium carbonate, etc., and it is possible to add up to about 100 parts per 100 parts of the trifluoroethylene chloride molten mixture powder. it can.

The addition of powders such as other solid lubricants, extreme pressure additives, and rust inhibitors has the effect that they surround the trifluoroethylene chloride melt mixture powder particles and further prevent fusion of the melt mixture powder particles to each other. Also occurs. Further, when an alkaline substance such as a metal soap or an anticorrosive agent is used, chlorine released from the trifluorochloroethylene polymer under extreme pressure can be trapped and an effect of suppressing metal corrosion can be expected. Examples of substances that can be expected to have such effects include metal soaps such as calcium stearate and barium stearate, metal soaps such as calcium oxide, calcium hydroxide, barium hydroxide and calcium carbonate, and rust preventives.

The composition of the present invention can be advantageously used as an additive to other lubricants for drawing.
Other drawing lubricants include, for example, graphite and fluorinated graphite.

The conventional method can be adopted as it is for the drawing process of the metal material using the solid lubricant of the present invention. That is, for the drawing process, for example, a method of filling a die to be used with the solid lubricant of the present invention and using several dies in series to perform cold drawing (cold drawing method) is adopted.

[0025]

EXAMPLES Next, the present invention will be explained based on Examples and Comparative Examples, but the present invention is not limited to such Examples.

Example 1 A solid lubricant for metal drawing was prepared by using the components shown in Table 1 in the amounts shown in the same table.

Compounding type A is a low polymer of trifluorochloroethylene (number average molecular weight of 1100 to 3000, melting point of 45 to
90 ° C.) powder having a particle size of 500 μm or less and highly polymerized trifluorochloroethylene (ZST 250 seconds, melting point 212 ° C.) powder having a particle size of 150 μm or less are thoroughly mixed with a V-type blender, and then a kneader is used to form 270 to 270. It was heated to 290 ° C., melted and mixed, cooled and solidified, and then pulverized to obtain a powder having a particle size of 500 μm or less.

The compounding type B is a molten mixture powder of compounding type A trifluorochloroethylene and a powder of metallic soap (calcium stearate as a specific example) powder (particle size 150 μm).
m or less) and dry mixed with a V-type blender.

In the compounding type C, the low polymerized powder of ethylene trifluoride chloride used in the compounding type A and the highly polymerized powder of ethylene trifluoride chloride (particle size 20 μm or less) are dry-mixed by a V-type blender. Prepared.

[0030]

[Table 1]

Example 2 With respect to each lubricant composition prepared in Example 1, the melting start temperature and the storage stability were examined by the following methods. Table 2 shows the results
Shown in

(Melting Onset Temperature) The lubricant composition is heated at a temperature rising rate of 2 ° C./min, and the temperature at which the powder in the composition begins to melt is visually examined under a microscope.

(Storage stability) 300 g of the lubricant composition was added to 3
Place in a synthetic resin bag with a volume of 00 ml, 50 ℃, 6
The mixture is allowed to stand at 0 ° C., 80 ° C. and 100 ° C. for 3 hours, and after cooling, the fusion state of the powder is examined. The evaluation criteria are as follows.

5: Does not set. 4: It hardens, but it crushes when pressed very lightly. 3: It hardens, but it crushes when pressed lightly. 2: Hardens, but crushes when pressed hard. 1: It solidifies and does not collapse even if pressed hard.

[0035]

[Table 2]

As is apparent from Table 2, a molten mixture of a low polymer and a high polymer of trifluorochloroethylene (type A).
In addition, in the case where type A and the same amount of metal soap are blended (type B), the melting start temperature is low polymerized substance alone (PCTFL).
It is 20 to 25 ° C. higher than the above, and this effect cannot be obtained with a simple mixture of a low polymer and a high polymer (Type C).

As a result, the storage stability of type A is type C.
It is one rank higher than that.

In Type B, surprisingly, fusion and solidification do not occur even when the melting start temperature is exceeded.

Example 3 The extreme pressure lubricity of the lubricant composition prepared in Example 1 was examined with a Falex tester. For comparison, in addition to a single powder of ethylene trifluoride chloride low polymer (PCTFEL) and a single powder of ethylene trifluoride chloride high polymer (PCTFEH), a metal soap that has been conventionally used alone, as specific examples Was also investigated for calcium stearate.
The results are shown in Table 3.

(Extreme pressure lubricity) Falex Corporation's Falex testing machine (standard type)
The lubricant composition is mixed with the same weight of di-2-ethylhexyl adipate in a mortar to form a grease, which is applied to a pin for measurement. The measurements were started with a static load of up to 300 lbs, started for 3 minutes, then manually turned the load gear to increase the load to 400 lbs.
The operation of driving for 1 minute and then driving for 1 minute while increasing the load by 100 pounds is continued, and the load (baking load) and time (baking start time) at the time when seizure occurs are examined.

[0041]

[Table 3]

As is clear from Table 3, the low-polymerization product of ethylene trifluoride chloride (PCTFEL) alone is superior in extreme pressure lubricity to metal soap, but it is a low-polymerization product of ethylene trifluoride chloride chloride. When metal soap (specific example, calcium stearate) is added to the molten mixture of the high polymer (Type B-1), the extreme pressure lubricity is significantly improved. This can be said to be the result of the two exhibiting their characteristics while complementing each other's drawbacks.

Example 4 A stainless steel wire (SUS-304) having a diameter of 2.0 mm was pulled down to a diameter of 0.7 mm using nine dies. With conventional metal soaps, the wire drawing speed was 200 m / min, and the die life was about 2 tons in terms of stainless steel wire.

In this case, as a lubricant, a die was subjected to a drawing process using the formulation example B-1 prepared in Example 1. The wire drawing speed could be increased to 600 m / min, and the die life could be doubled to about 4 tons.

[0045]

EFFECTS OF THE INVENTION When the solid lubricant composition for drawing metal material of the present invention is used, heat fusion of lubricant particles does not occur during use, and excellent extreme pressure lubricity is obtained during drawing metal material. In addition, the lubricant film on the metal surface after processing is in good condition, and excellent effects such as improvement of product quality and yield are achieved, work safety is high, and drawing speed and area reduction rate are high. Machining conditions such as and die life are also greatly improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C10M 107: 38 105: 24) C10N 20:00 A 30:06 40:24 Z 50:08 50: 10 (72) Inventor Masanori Yamada 1-33 Nishiichitsuya, Settsu City, Osaka Prefecture Kyoei Kasei Kogyo Co., Ltd. (72) Inventor Takeshi Kimura 1-32 Hotaruikenishicho, Toyonaka City, Osaka Prefecture

Claims (5)

[Claims] 1. A low polymer of trifluorochloroethylene and a high polymer of trifluorochloroethylene are melt-mixed and pulverized at a low polymer / high polymer weight ratio of 95/5 to 30/70. A resin composition containing the obtained powder. 2. A low polymer of trifluorochloroethylene and a high polymer of trifluorochloroethylene are melt-mixed and pulverized at a low polymer / high polymer weight ratio of 95/5 to 30/70. A solid lubricant composition for drawing a metal material containing the powder thus obtained. 3. The composition according to claim 1, wherein the low melting point polymer of ethylene trifluoride chloride has a melting point of 45 to 90 ° C., and the melting point point of the high polymer of ethylene trifluoride chloride is 210 to 230 ° C. 4. A composition according to claim 1, 2 or 3 which comprises a powder of metallic soap or alkaline soap. 5. The composition according to claim 4, wherein the amount of the metal soap or alkali soap is 1000 parts by weight or less per 100 parts by weight of the composition.