LUBRICANTS FOR USE IN PROCESSING OF METALLIC MATERIAL AND METHODS FOR PROCESSING THE METALLIC MATERIAL USING THE LUBRICANTS

- Toyota

A nonchlorine lubricant for use in processing of a metallic material includes a lubricant base. The lubricant base includes at least one member selected from the group consisting of the vegetable oils and the neopentylated polyol esters. The lubricant may further include an additive added to the lubricant base. The additive comprises a sulfuric extreme pressure agent, an organozinc compound and a calcium ingredient. Preferably, the additive is added to the lubricant base such that sulfur content, zinc content and calcium content in the lubricant are respectively 5.0-50 wt %, 0.2-10 wt % and 0.01-10 wt % of total weight of the lubricant.

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Description
TECHNICAL FIELD

The present invention relates to lubricants for use in processing (e.g., press working) of a metallic material (which is also referred to as metal processing). Further, the present invention relates to methods for processing the metallic material using the lubricants.

BACKGROUND ART

Examples of known metal processing technique for manufacturing a product (e.g., a car part) may include press working (e.g., press forming, shearing (blanking, die cutting, half die cutting and punching)), bending, burring, drawing and rolling, each of which can be performed by means of a processing tool (e.g., a mold). For example, in shearing (one of press working), a metallic material (a processed material) may preferably be stamped out with a mold (i.e., a punch and die assembly), thereby producing a formed article. The formed article thus produced is relatively finely finished. Therefore, the formed article produced by shearing does not substantially require additional processing such as cutting, grinding, or other such processing. In particular, in fine shearing, for example, in fine blanking (FB), the formed article is more finely finished than the formed article produced by normal shearing. Thus, the formed article produced by FB can be used as an end product without additional processing. This may lead to a reduced number of manufacturing processes of the product. For these reasons, in recent years, fine shearing as typified by FB has been broadly used in a metal processing field for manufacturing car parts or other such parts.

In processing of the metallic material, lubricants are generally applied between the metallic material and the processing tool, e.g., the mold (the punch and die assembly), in order to reduce frictional heat generated therebetween or to prevent formation of “burr” or “shear drop” on a processed surface (e.g., a shear surface) of the metallic material. The lubricants thus applied may effectively prevent the processing tool (the mold) from wearing by the frictional heat. In addition, the lubricants may effectively increase processing accuracy of the metallic material. Generally, shearing may generate a large shear stress between the metallic material and the mold (the punch and die assembly). In particular, fine shearing may generate a shear stress greater than the normal shearing. Therefore, the lubricants for use in shearing and fine shearing require excellent lubricity and seize resistance.

Conventionally, in metal processing, chlorine lubricants have been broadly used. The chlorine lubricants can provide good lubricity and seize resistance. However, chlorine ingredients contained in the chlorine lubricants can be easily decomposed to produce undesirable decomposition products during processing or with time. The decomposition products thus produced may rust the metallic material and the processing tool (the mold). Further, the chlorine ingredients may produce harmful or toxic substances when they are incinerated. Also, the chlorine ingredients may corrode or damage incinerators. In order to solve these problems, there is a need to develop improved or nonchlorine lubricants that can provide substantially the same lubricity and seize resistance as the chlorine lubricants.

Up to now some nonchlorine lubricants for use in metal processing have been developed. For example, Japanese Laid-open Patent Publication Number 2002-155293 teaches a nonchlorine lubricative composition for use in metal processing, which composition includes a lubricant base (mineral oils or synthetic oils) and an additive (a sulfuric extreme pressure agent, organozinc compounds and imide compounds) added to the lubricant base. Japanese Patent Number 2,641,203 teaches a nonchlorine lubricative composition for use in metal processing, which composition includes a lubricant base (mineral oils or other such oils) and an additive (a sulfuric extreme pressure agent and highly-basic metal sulfonates) added to the lubricant base Further, Japanese Laid-open Patent Publication Number 8-20790 teaches a nonchlorine lubricative composition for use in metal processing, which composition includes a lubricant base (mineral oils or synthetic oils) and an additive (a sulfuric extreme pressure agent (e.g., olefin polysulfides), highly-basic metal sulfonates and organozinc compounds) added to the lubricant base.

However, the known nonchlorine lubricative compositions generally contain mineral oils as the lubricant base. Therefore, such lubricative compositions may produce a bad smell caused by the mineral oils during processing. This may lead to deterioration of working condition. In addition, the mineral oils generally have high kinetic viscosity. The high kinetic viscosity of the mineral oils may lead to clogging of filters of a metal processing machine. Also, due to the high kinetic viscosity of the mineral oils, the lubricative compositions may have reduced self-removability. Therefore, the lubricative compositions cannot be easily removed or washed out from a formed article. Further, the lubricative composition taught by Publication Number '293 does not have sufficient lubricity and seize resistance. Therefore, such a lubricative composition is not suitable for press working, in particular, fine shearing. In other words, if this lubricative composition is used in shearing, the mold (the punch and die assembly) can be rapidly worn out because of inferior lubricity of the lubricative composition. Naturally, shearing speed cannot be increased. This may lead to reduced productivity. Similarly, the lubricative compositions taught by patent Number '203 and Publication Number '790 do not have sufficient lubricity and seize resistance. Therefore, these lubricative compositions are also not suitable for press working such as fine shearing.

DISCLOSURE OF INVENTION

It is, accordingly, one object of the present invention to provide an improved nonchlorine lubricant for use in processing of a metallic material.

In one embodiment of the present invention, a nonchlorine lubricant is taught for use in processing of a metallic material. The lubricant includes a lubricant base. The lubricant base includes at least one member selected from the group consisting of the vegetable oils and the neopentylated polyol esters.

According to the present lubricant, the lubricant does not produce a bad smell because the lubricant does not contain mineral oils. Therefore, the lubricant does not deteriorate working condition. Furthermore, the lubricant may be friendly for the environment. In addition, the lubricant is less subject to solidifying because the lubricant does not contain animal oils.

The lubricant may further include an additive added to the lubricant base. The additive may include a sulfuric extreme pressure agent, an organozinc compound and a calcium ingredient. Preferably, the additive is added to the lubricant base such that sulfur content, zinc content and calcium content in the lubricant are respectively 5.0-50 wt %, 0.2-10 wt % and 0.01-10 wt % of total weight of the lubricant.

The lubricant thus formulated may have substantially the same lubricity and seize resistance as the conventional chlorine lubricants.

Further, in another embodiment of the present invention, a method is taught for processing a metallic material using a processing tool. The method includes the steps of feeding the nonchlorine lubricant that is described above between the metallic material and the processing tool.

According to the present method, frictional heat generated between the metallic material and the processing tool can be effectively reduced, so that the processing tool can be prevented from wearing. As a result, the processing tool may have a long service life. Further, formation of “burr” or “shear drop” on a processed surface (e.g., a shear surface) of the metallic material can be prevented.

Other objects, features and advantages of the present invention will be readily understood after reading the following detailed description together with the claims.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following, a detailed representative embodiment of the present invention will be described.

A lubricant for use in processing of a metallic material may include vegetable oils and/or neopentylated polyol esters as a lubricant base. Preferably, the lubricant may include a (nonchlorine) additive added to the lubricant base. The additive may be a sulfuric extreme pressure agent (Ingredient A), an organozine compound (Ingredient B) and a calcium ingredient (ingredient C). The lubricant may have substantially the same lubricity and seize resistance as known chlorine lubricants by appropriately controlling or determining the sulfur content, the zinc content and the calcium content contained therein. As will be recognized, the lubricant contains neither mineral oils nor chlorine ingredients. Therefore, the lubricant does not deteriorate working condition. Also, the lubricant does not produce harmful or toxic substances if it is incinerated. In addition, the vegetable oils contained in the lubricant are less subject to solidification than the other oils (e.g., animal oils). As a result, the lubricant may have increased self-removability. Further, according to the lubricant, filters of a metal processing machine may preferably be prevented from clogging.

First, the lubricant base of the lubricant will be described. In this embodiment, the lubricant base may be at least one member selected from the group consisting of the vegetable oils and neopentylated polyol esters. In other words, the vegetable oils and the neopentylated polyol esters can be used in either a pure form or in a combined form. In addition, when the vegetable oils and the neopentylated polyol esters are used in the combined form, they can be mixed in various combinations, i.e., combinations of one or more vegetable oils and one or more neopentylated polyol esters, combinations of two or more vegetable oils only, or combinations of two or more neopentylated polyol esters only. The vegetable oils and the neopentylated polyol esters may preferably include all vegetable oils and neopentylated polyol esters that are known per se for use in a composition for processing a metallic material. In other words, the vegetable oils and the neopentylated polyol esters are not limited to special vegetable oils and special neopentylated polyol esters. However, it is preferable that the vegetable oils and the neopentylated polyol esters may have kinetic viscosity of 1 mm2/s to 1000 mm2/s at 40° C., more preferably 5 mm2/s to 100 mm2/s at 40° C.

Examples of the vegetable oils are linseed oil, safflower oil, soy been oil, sesame oil, corn oil, canola oil, cotton seed oil, olive oil, rice bran oil, coconut oil, palm oil, palm kernel oil and hydrogenated products thereof. Generally, it is preferable that the vegetable oils mainly contain fatty acids (more preferably linear fatty acids) having a carbon number of 8-22. Further, in view of the fact that the vegetable oils are usually used for foods, the vegetable oils do not generally produce a bad smell.

Examples of the neopentylated polyol esters are neopentylglycol, trimethylolpropane, pentaerythritol and dipentaerythritol. These exemplified compounds may have excellent heat resistance and lubricity, high ignition points and low volatility. However, trimethylolpropane and pentaerythritol are more preferable in view of heat resistance, volatility and lubricity. Generally, it is preferable that the neopentylated polyol esters contain alkyl groups having a carbon number of 7-22.

In the present invention, content of the vegetable oils and/or the neopentylated polyol esters in the lubricant is 40-80 wt % (not less than 40 wt % and not greater than 80 wt %) of total weight of the lubricant, preferably 50-70 wt %, and more preferably 55-65 wt %. In such a range of content of the vegetable oils and/or the neopentylated polyol esters, the lubricant may have sufficient lubricating performance and have substantial effects of the additive. In the content of 55-65 wt %, the lubricating performance and the effects of the additive are maximized. If the content of the vegetable oils and/or the neopentylated polyol esters in the formulated lubricant is less than 30 wt % of total weight of the lubricant, the lubricant may have insufficient lubricating performance. On the contrary, even if the content of the vegetable oils and/or the neopentylated polyol esters in, the formulated lubricant is greater than 80 wt % of total weight of the lubricant, the lubricant may only have limited performance and effects. In addition, if the content of the vegetable oils and/or the neopentylated polyol esters is excessively increased (e.g., greater than 80 wt %), content of the additive is inversely extremely reduced, so that the lubricant cannot have substantial effects of the additive.

Next, the additive of the lubricant, i.e., the sulfuric extreme pressure agent (Ingredient A), the organozinc compound (Ingredient B) and the calcium ingredient (Ingredient C) will be described.

In this embodiment, the sulfuric extreme pressure agent (Ingredient A) may preferably include various types of sulfuric compounds that can provide extreme pressure property. In other words, the sulfuric extreme pressure agent is not limited to special sulfuric compounds. Examples of the sulfuric extreme pressure agent are sulfurized fats, sulfurized fatty acids, sulfuric esters, sulfurized olefins, polysulfides, thiocarbamates and sulfurized mineral oils. The exemplified compounds for the sulfuric extreme pressure agent can be used in either a pure form or in a combined form.

Further, the sulfurized fats may preferably be made by reacting sulfur with various types of fats (e.g., lard oils, whale oils, vegetable oils and fish oils). The sulfurized fats may include a sulfurized lard, a sulfurized canola oil, a sulfurized caster oil and a sulfurized soy been oil.

In addition, the sulfurized fatty acids may include a sulfide of oleic acid. Also, the sulfuric esters may include a sulfide of methyl oleate and a sulfide of octyl rice bran fatty acid. The sulfurized olefins may preferably be produced by reacting C2-C15 olefins or their multimers (e.g., dimers, trimers or tetramers) with a sulfurizing agent such as sulfur and sulfur chloride.

Examples of the polysulfides are dibenzylpolysulfides, di-tert-nonylpolysulfides, didodecylpolysulfides, di-tert-butylpolysulfides, dioctylpolysulfides, diphenylpolysulfides and dicyclohexylpolysulfides.

Examples of the thiocarbamates are zinc thiocarbamates, dilaurylthiodipropionates and distearylthiodipropionates.

The sulfurized mineral oils may preferably be produced by dissolving elementary sulfur into mineral oils. The mineral oils for use in preparation of the sulfurized mineral oils may be, for example, but are not limited to, many kinds of oils that can be produced in a general petroleum refinery process.

The organozine compound (ingredient B) may include zinc dialkyldithiophosphate (which will be referred to ZnDTP hereinafter) and zinc dialkyldithiocarbamic acid (which will be referred to ZnDTC hereinafter). Alkyl groups contained in ZnDTP and ZnDTC may be identical with or different from each other. That is, in ZnDTP, two alkyl groups bonding to a phosphorus atom via an oxygen atom may be identical with or different from each other. Similarly, in ZnDTC, two alkyl groups bonding to a nitrogen atom may be identical with or different from each other. The alkyl groups contained in ZnDTP and ZnDTC may preferably be alkyl groups having a carbon number of three or more. Further, these alkyl groups can be replaced by aryl groups. In addition, the above-described compounds for the organozinc compound can be used in either a pure form or in a combined form.

Moreover, the calcium ingredient (Ingredient C) may include, but are not limited to, calcium sulfonates, calcium salicylates and calcium phenates. However, the calcium sulfonates are preferred in terms of kinetic viscosity and price. More preferred are basic calcium sulfonates. Further more preferred are highly-basic calcium sulfonates having base value of 300 mgKOH/g or more. In addition, the above-described compounds for the calcium ingredient can be used in either a pure form or in a combined form.

As described above, the lubricant of the present invention may preferably be formulated by adding the additive (Ingredient A, Ingredient B and Ingredient C) to the lubricant base (i.e., the vegetable oils and/or the neopentylated polyol esters). In the present invention, the lubricant may be formulated such that sulfur content in the formulated lubricant is preferably 5.0-50 wt % (not less than 5.0 wt % and not greater than 50 wt %) of total weight of the lubricant, more preferably 6.0-30 wt %. If the sulfur content in the formulated lubricant is less than 5.0 wt % of total weight of the lubricant, the lubricant may have insufficient seize resistance and lubricity. On the contrary, if the sulfur content in the formulated lubricant is greater than 50 wt % of total weight of the lubricant, the lubricant may only have limited performance and effects.

Further, the lubricant may be formulated such that zinc content in the lubricant is preferably 0.2-10 wt % (not less than 0.2 wt % and not greater than 10 wt %) of total weight of the lubricant, more preferably 0.3-5.0 wt %. If the zinc content in the formulated lubricant is less than 0.2 wt % of total weight of the lubricant, the lubricant may have insufficient seize resistance and lubricity. Conversely, even if the zinc content in the formulated lubricant is greater than 10 wt % of total weight of the lubricant, the lubricant may only have limited effects.

Further, the lubricant may be formulated such that calcium content in the lubricant is preferably 0.01-10 wt % (not less than 0.01 wt % and not greater than 10 wt %) of total weight of the lubricant, more preferably 0.5-5.0 wt %. If the calcium content in the formulated lubricant is less than 0.01 wt % of total weight of the lubricant, the lubricant may have insufficient seize resistance and lubricity. On the contrary, if the calcium content in the formulated lubricant is greater than 10 wt % of total weight of the lubricant, the lubricant may only have limited effects.

As described above, the additive for use in the preparation of the lubricant essentially consists of the sulfuric extreme pressure agent (Ingredient A), the organozinc compound (Ingredient B) and the calcium ingredient (Ingredient C). However, various types of known additional agents can be added to the lubricant without obscuring the object of the invention in order to increase or stabilize basic properties of the lubricant, if necessary. The known additional agents may include a viscosity modifying agent, a rust inhibitive agent, an antioxidizing agent, a corrosion prevention agent, a coloring agent, an antifoaming agent and a fragrant material.

The viscosity modifying agent may preferably include all viscosity modifying agents that are known per se for use in a composition for processing a metallic material. In other words, the viscosity modifying agent is not limited to special viscosity modifying agents. However, the viscosity modifying agent may preferably be added so that the lubricant may have kinetic viscosity of 1 mm2/s to 1000 mm2/s at 40° C., more preferably 5 mm2/s to 100 mm2/s at 40° C.

The rust inhibitive agent is not limited to special compounds. Examples of the rust inhibitive agent are calcium-based rust inhibitive agent, barium-based rust inhibitive agent and wax-based rust inhibitive agent. Examples of the antioxidizing agent are amine series compounds and phenolic compounds. Examples of the corrosion prevention agent, are benzotriazols, tolyltriazols and mercaptobenzothiazoles. Further, the coloring agent may be various types of dyes and pigments.

The lubricant of the present invention may have beneficial effects in various processing of the metallic material such as press working (e.g., press forming, shearing (blanking, die cutting, half die cutting and punching)), bending, burring, drawing and rolling, each of which can be performed by means of a special processing tool. In particular, the lubricant may have beneficial effects in shearing (in particular, fine shearing as typified by fine blanking (FB)).

Also, the lubricant of the present invention does not contain chlorine components. Therefore, the lubricant may have rust inhibiting performance greater than the conventional lubricants. That is, the lubricant may effectively prevent a processing tool (or a mold) and the processed metallic material from rusting. In addition, the lubricant may effectively increase processing accuracy of the metallic material when it is fed between the metallic material and the processing tool (the mold). Moreover, the lubricant can be use for processing various types of metallic materials, e.g., stainless steel, alloy steels, carbon steels and aluminum alloys. However, the lubricant may provide particularly beneficial effects when applied to the alloy steels and the carbon steels.

A representative method for processing the metallic material using the lubricant will now be described.

As described above, the lubricant is formulated by adding the additive (i.e., Ingredient A, Ingredient B and Ingredient C) to the lubricant base. Subsequently, the formulated lubricant is applied between the metallic material and the processing tool (the mold) in order to lubricate therebetween when the metallic material is processed. Thus, the metallic material can be smoothly processed (e.g., sheared) with a high degree of processing accuracy.

Generally, the lubricant may be applied to the metallic material by means of, for example, but are not limited to, a roller and a sprayer. The lubricant thus applied may effectively increase processing accuracy of the metallic material. In addition, the lubricant that is applied between the metallic material and the processing tool (the mold) may effectively protect the processing tool from rusting and damaging, thereby providing a prolonged working life of the processing tool.

The examples of the lubricant of the present invention will now be described. Further, the following examples are illustrative and should not be construed as limitations of the invention.

In the following description, the content of each ingredient was expressed as a weight part. In addition, the sulfur content (%) was expressed as a weight percent of sulfur atom to the total weight of each lubricant. Similarly, the zinc content (%) was expressed as a weight percent of zinc atom to the total weight of each lubricant. Further, the calcium content (%) was expressed as a weight percent of calcium atom to the total weight of each lubricant.

In a first test, seven example lubricants (Examples 1-7; nonchlorine lubricants) and one control lubricant (Control 1; chlorine lubricant) were prepared by utilizing substances listed below as the lubricant base and the additive. Compositions of the seven types of example lubricants (Examples 1-7) and the control lubricant (Control 1) are shown in Table 1.

(1) The lubricant base (which will be referred to as “LB”)

    • LB1: canola oil
    • LB2: palm oil
    • LB3: safflower oil
    • LB4: trimethylolpropane (C12)
    • LB5: trimethylolpropane (C18)
    • LB6: pentaerythritol (C12)
    • LB7: pentaerythritol (C18)

(2) The additive

    • a) The sulfuric extreme pressure agent (Ingredient A)
      • a1: polysulfides (32 wt % sulfur content)
      • a2: sulfrized fats (15 wt % sulfur content)
    • b) The organozinc compound (Ingredient B)
      • b1: ZnDTP (9 wt % zinc content; 16 wt % sulfur content)
    • c) The calcium ingredient (Ingredient C)
      • c1: calcium sulfonates (15 wt % calcium content)
    • d) Other additives (Ingredient D)
      • d1: chlorinated paraffins (50 wt % chlorine content)

With regard to the lubricants of Examples 1-7 and Control 1, a lubrication performance evaluation test was performed. In order to perform the lubrication performance evaluation test, work pieces having the lubricants were respectively processed (sheared or punched), so as to produce formed articles (test pieces).

Preparation of the formed articles was carried out under following conditions.

Processing Machine

Link-motion pressing machine (AIDA) having two punches and dies

    • Work piece feed: 23.5 mm
    • Material of the punch 1: SKD11
    • Material of the punch 2: SKD11+TiN coating
    • Material of the dies: SKD11

Work Pieces

SPH 440

    • Width: 70 mm
    • Thickness 4.6 mm

Application of the Lubricants

    • The lubricants of Examples 1-7 and Control 1 were uniformly fed to the surfaces of the work pieces by a resin roll coater.

Processing

    • The work pieces having the lubricants were respectively subjected to processing (shearing or punching) by the punches 1 and 2, thereby producing the formed articles (test pieces) that have a pair of punched holes each having a size of 10 mm (length)×12 mm (width)×4.6 mm (depth). The two punches 1 and 2 were arranged such that the two punched holes were simultaneously formed. Further, with regard to each of the work pieces, a pressing load required for processing was measured.

After processing, the punches 1 and 2 were visually observed for the surface appearance thereof, so as to determine occurrence of defects, including wear, seizing, damage and stripping of TiN coating. From the appearance, the punches 1 and 2 were evaluated based on the following reference levels:

A: Superior (No defects)

B: Fine or Good (Substantially no defects)

C: Poor (Minor defects)

D: Inferior (Significant defects)

In addition, the formed articles thus formed were visually observed for the sheared surface appearance of the punched holes (i.e., processing accuracy of the formed articles), so as to determine occurrence of defects, including burr and shear drop. From the observed appearance, the sheared surface appearance of the punched holes were evaluated based on the following reference levels:

A: Superior (No defects)

B: Fine or Good (Substantially no defects)

C: Poor Minor defects)

D: Inferior (Significant defects)

Results are shown in Table 1.

TABLE 1 Examples Control 1 2 3 4 5 6 7 1 LB1 60 LB2 60 LB3 60 LB4 60 LB5 60 LB6 60 LB7 60 a1 10 10 10 10 10 10 10 a2 10 10 10 10 10 10 10 b1 10 10 10 10 10 10 10 c1 10 10 10 10 10 10 10 d1 70 Sulfur 6.3 6.3 6.3 6.3 6.3 6.3 6.3 — Content (%) Zinc 0.9 0.9 0.9 0.9 0.9 0.9 0.9 — Content (%) Calcium 1.5 1.5 1.5 1.5 1.5 1.5 1.5 — Content (%) Chlorine — — — — — — — 35 Content (%) Pressing 93 93 98 93 92 98 97 97 Load (ton) Appearance A A A A A A A A of Punches Appearance A A B B A B A A of Punched Holes

As shown in Table 1, with regard to Examples 1-7 and Control 1, the punches 1 and 2 may have superior surface appearance. This means that the lubricants of Examples 1-7 and Control 1 may prevent the punches 1 and 2 from wearing during processing. Also, with regard to Examples 1-7 and Control 1, the punched holes of the formed articles may have superior sheared surface appearance. This means that the lubricants of Examples 1-7 and Control 1 may form the punched holes free from burr and shear drop. These results demonstrate that the lubricants of Examples 1-7 may have excellent seize resistance and lubricity that are same as or similar to the (chlorine) lubricant of Control 1.

Further, it is demonstrated that the lubricants of Examples 1, 2, 5 and 7 may have greater performance than the chlorine lubricant of Control I in that, according to these lubricant, the work pieces can be processed (punched) under a lesser pressing load (92-93 ton). In addition, it is demonstrated that the vegetable oils (Examples 1-3) may have substantially the same performance as the neopentylated polyol (Examples 4-7). Further, as will be apparent from comparing Examples 4 and 5 (or Examples 6 and 7), the neopentylated polyol esters having a larger carbon number may have a greater performance than the neopentylated polyol esters having a smaller carbon number. Moreover, as will be apparent from comparing Examples 1-3, the lubricant base substances LB1 and LB2 (canola oil and palm oil) may have a performance slightly greater than the lubricant base substance LB3 (safflower oil). Similarly, as will be apparent from comparing Examples 4-7, the lubricant base substances LB4 and LB5 (trimethylolpropane) may have a performance slightly greater than the lubricant base substances LB6 and LB7 (pentaerythritol).

In a second test, two example lubricants (Examples 8 and 9; nonchlorine lubricants) were prepared by utilizing the above listed substances as the lubricant base and the additive. Compositions of the two types of lubricants (Examples 8 and 9) are shown in Table 2. In Example 8, a combination of the lubricant base substances LB1 and LB4 are used as the lubricant base. As will be recognized, the lubricant base substances LB1 and LB4 are respectively have a relatively excellent performance as demonstrated in the first test. To the contrary, in Example 9, a combination of the lubricant base substances LB3 and LB6 are used as the lubricant base. As will be recognized, the lubricant base substances LB3 and LB6 are respectively have a relatively inferior performance as demonstrated in the first test.

With regard to the lubricants of Examples 8 and 9, a lubrication performance evaluation test was performed in the same manner as the first test. Results are shown in Table 2.

TABLE 2 Examples 8 9 LB 1 30 LB2 LB3 30 LB4 30 LB5 LB6 30 LB7 a1 10 10 a2 10 10 b1 10 10 c1 10 10 d1 Sulfur Content (%) 6.3 6.3 Zinc Content (%) 0.9 0.9 Calcium Content (%) 1.5 1.5 Chlorine Content (%) — — Pressing Load (ton) 93 98 Appearance of A A Punches Appearance of A B Punched Holes

Table 2 demonstrates that the lubricants of Examples 8 and 9 may have good seize resistance and lubricity similar to Examples 1-7. Further, as will be apparent from Tables 1 and 2, the combination of the lubricant base substances LB1 and LB4 may have substantially the same performance as the lubricant base substance LB1 or LB4 in the pure form. Similarly, the combination of the lubricant base substances LB3 and LB6 may have substantially the same performance as the lubricant base substance LB3 or LB6 in the pure form.

In a third test, six example lubricants (Examples 10-15) were prepared by utilizing the above listed substances as the lubricant base and the additive. Compositions of the six types of lubricants (Examples 10-15) are shown in Table 3. In these examples, only the lubricant base substance LB1 having a relatively excellent performance as demonstrated in the first test is used as the lubricant base. Also, only the additive substances a1 and a2 (Ingredient A) are used as the additive. The additive substances a1 and a2 are respectively added so that the formulated lubricants may have various sulfur content.

With regard to the lubricants of Examples 10-15, a lubrication performance evaluation test was performed in the same manner as the first test. Results are shown in Table 3.

TABLE 3 Examples 10 11 12 13 14 15 LB1 70 80 90 70 80 90 a1 30 20 10 15 10 5 a2 15 10 5 Sulfur Content (%) 9.6 6.4 3.2 7.1 4.7 2.1 Zinc Content (%) — — — — — — Calcium Content (%) — — — — — — Pressing Load (ton) 93 98 106 94 100 110 Appearance of B B D B C D Punches Appearance of B C D B C D Punched Holes

As shown in Table 3, according to the lubricants of Examples 10 and 13 having a greater sulfur content, the punches 1 and 2 may have excellent surface appearance. Also, the punched holes of the formed articles may have excellent sheared surface appearance. To the contrary, according to the lubricants of Examples 12 and 15 having a lesser sulfur content, the punches 1 and 2 may have inferior surface appearance. Also, the punched holes of the formed articles may have inferior sheared surface appearance. These results means that the lubricants having a greater sulfur content may generally have greater seize resistance and lubricity than the lubricants having a lesser sulfur content. Further, by comparing Example 11 with Example 14, it is presumed that an appropriate sulfur content may preferably be about 5.0% or more, more preferably be about 6.0% or more.

In a fourth test, three example lubricants (Examples 16-18) were prepared by utilizing the above listed substances as the lubricant base and the additive. Compositions of the three types of lubricants (Examples 16-18) are shown in Table 4. In these examples, only the lubricant base substance LB1 is used as the lubricant base. However, all of the additive substances a1, a2, b1 and c1 (Ingredients A-C) are used as the additive. The additive substances b1 is added so that the formulated lubricants may have various zinc content.

With regard to the lubricants of Examples 16-18, a lubrication performance evaluation test was performed in the same manner as the first test. Results are shown in Table 4.

TABLE 4 Examples 16 17 18 LB 1 74 72 70 a1 10 10 10 a2 10 10 10 b1 1 3 5 c1 5 5 5 Sulfur Content (%) 4.9 5.2 5.5 Zinc Content (%) 0.1 0.3 0.5 Calcium Content (%) 0.75 0.75 0.75 Pressing Load (ton) 101 97 96 Appearance of C B A Punches Appearance of C B A Punched Holes

As will be apparent from Table 3, the lubricants having a greater zinc content may generally have greater seize resistance and lubricity than the lubricants having a lesser zinc content. Further, by comparing Example 16 with Example 17, it is presumed that an appropriate zinc content may preferably be about 0.2% or more, more preferably be about 0.3% or more.

In a fifth test, four example lubricants (Examples 19-22) were prepared by utilizing the above listed substances as the lubricant base and the additive. Compositions of the four types of lubricants (Examples 19-22) are shown in Table 5. In these examples, only the lubricant base substance LB1 is used as the lubricant base. However, all of the additive substances a1, a2, b1 and c1 (Ingredients A-C) are used as the additive. The additive substances c1 is added so that the formulated lubricants may have various calcium content.

With regard to the lubricants of Examples 19-22, a lubrication performance evaluation test was performed in the same manner as the first test. Results are shown in Table 5.

TABLE 5 Examples 19 20 21 22 LB 1 69.5 69 67 65 a1 10 10 10 10 a2 10 10 10 10 b1 10 10 10 10 c1 0.5 1 3 5 Sulfur Content (%) 6.3 6.3 6.3 6.3 Zinc Content (%) 0.9 0.9 0.9 0.9 Calcium Content (%) 0.1 0.2 0.5 0.75 Pressing Load (ton) 97 97 95 95 Appearance of B B B A Punches Appearance of C C B A Punched Holes

As will be apparent from Table 5, the lubricants having a greater calcium content may generally have greater seize resistance and lubricity than the lubricants having a lesser calcium content. Further, from these results shown in Table 5, it is presumed that an appropriate calcium content may preferably be about 0.01% or more, more preferably be about 0.5% or more.

In a sixth test, four control lubricants (Controls 2-5) were prepared by utilizing the above listed substances. Compositions of the four types of control lubricants (Controls 2-5) are shown in Table 6. As will be apparent form Table 6, in these controls, the lubricant base is not used. That is, the controls are formulated from only the additive substances a1, a2, b1 or c1.

With regard to the control lubricants of Controls 2-5, a lubrication performance evaluation test was performed in the same manner as the first test. Results are shown in Table 6.

TABLE 6 Controls 2 3 4 5 LB 1 — — — — a1 100 a2 100 b1 100 c1 100 Sulfur Content (%) 32 15 16 Zinc Content (%) 9 Calcium Content (%) 15 Pressing Load (ton) 108 100 102 110 Appearance of D C C D Punches Appearance of C C C C Punched Holes

As will be apparent from Table 6, the control lubricants containing no lubricant base may have inferior seize resistance and lubricity.

The results of the first to sixth tests demonstrate that the lubricant of the present invention may have excellent performance (e.g., excellent seize resistance and lubricity) that are same as or similar to the conventional chlorine lubricant when they are used for processing (in particular, shearing) of the metallic material. This means that the present lubricant may be suitable for processing (in particular, shearing) of the metallic material. The lubricant may preferably contain both of the lubricant base and the additive at a desired ratio. The lubricant base may be the vegetable oils and/or the neopentylated polyol esters. The additive may be the sulfuric extreme pressure agent (Ingredient A), the organozinc compound (Ingredient B) and the calcium ingredient (Ingredient C). The sulfur content in the lubricant may preferably be 5.0-50% of total weight of the lubricant. The zinc content in the lubricant may preferably be 0.2-10% of total weight of the lubricant. The calcium content in the lubricant may preferably be 0.01-10% of total weight of the lubricant.

A representative embodiment of the present invention has been described in detail. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the foregoing detail description, may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe detailed representative examples of the invention. Moreover, the various features taught in this specification may be combined in ways that are not specifically enumerated in order to obtain additional useful embodiments of the present teachings.

Claims

1-8. (canceled)

9. A nonchlorine lubricant for use in processing of a metallic material, comprising:

a lubricant base, and
an additive added to the lubricant base,
wherein the lubricant base comprises at least one member selected from the group consisting of vegetable oils and neopentylated polyol esters,
wherein content of the vegetable oils and/or the neopentylated polyol esters in the lubricant is 40-80 wt % of total weight of the lubricant,
wherein the additive comprises a sulfuric extreme pressure agent, an organozinc compound and a calcium ingredient,
wherein the additive is added to the lubricant base such that sulfur content, zinc content and calcium content in the lubricant are respectively 5.0-50 wt %, 0.2-10 wt % and 0.01-10 wt % of total weight of the lubricant, and
wherein the calcium ingredient comprises highly-basic calcium sulfonates having base value of 300 mgKOH/g or more.

10. The nonchlorine lubricant as defined in claim 9, wherein the processing of a metallic material comprises shearing of the metallic material.

11. The nonchlorine lubricant as defined in claim 9, wherein the organozinc compound comprises at least one member selected from the group consisting of zinc dialkyldithiophosphate and zinc dialkyldithiocarbamic acid.

12. A method for processing a metallic material using a processing tool, comprising the steps of:

feeding a nonchlorine lubricant between the metallic material and the processing tool,
wherein the lubricant comprises a lubricant base and an additive added to the lubricant base,
wherein the lubricant base comprises at least one member selected from the group consisting of vegetable oils and neopentylated polyol esters,
wherein content of the vegetable oils and/or the neopentylated polyol esters in the lubricant is 40-80 wt % of total weight of the lubricant,
wherein the additive comprises a sulfuric extreme pressure agent, an organozinc compound and a calcium ingredient,
wherein the additive is added to the lubricant base such that sulfur content, zinc content and calcium content in the lubricant are respectively 5.0-50 wt %, 0.2-10 wt % and 0.01-10 wt % of total weight of the lubricant, and
wherein the calcium ingredient comprises highly-basic calcium sulfonates having base value of 300 mgKOH/g or more.

13. The method as defined in claim 12, wherein the processing of a metallic material comprises shearing of the metallic material.

14. The method as defined in claim 12, wherein the organozinc compound comprises at least one member selected from the group consisting of zinc dialkyldithiophosphate and zinc dialkyldithiocarbamic acid.

Patent History
Publication number: 20090239774
Type: Application
Filed: Jun 15, 2007
Publication Date: Sep 24, 2009
Applicant: TOYOTA BOSHOKU KABUSHIKI KAISHA (Aichi-ken)
Inventors: Mami Kato ( Aichi), Teruo Fukaya ( Aichi)
Application Number: 12/302,307