JP6702375B2 - Lubricant composition for chain and chain - Google Patents

Description

The present invention relates to a chain lubricant composition and a chain to which the lubricant composition is applied.

BACKGROUND ART Conventionally, as a chain lubricant composition used for chain lubrication, a composition containing a base oil and a thickener is known. For example, as disclosed in Patent Document 1, polymerized polyethylene wax, polymethacrylate, and polyisobutylene are known as thickeners used in a lubricant composition for chains.

JP, 2005-013966, A

In the chain lubricant composition containing polyethylene wax as the thickener as in the above-mentioned conventional technique, the base oil and the polyethylene wax are easily separated. The base oil separated in this way exudes from the chain, and the area around the chain easily becomes dirty. Here, from the viewpoint of suppressing the exudation of the base oil from the chain, there are thickeners more preferable than polyethylene wax, but when such a thickener is used, the outer surface of the chain becomes easily sticky. If the outer surface of the chain becomes sticky, dust is likely to adhere to the chain, which may impair the appearance of the chain and may require time and effort to remove the dust adhering to the chain.

The present invention has been made paying attention to such an actual situation. It is an object of the present invention to provide a chain lubricant composition capable of suppressing stickiness on the outer surface of the chain even when the resistance to exudation from the chain is enhanced, and a chain.

A chain lubricant composition for solving the above-mentioned problems is a chain lubricant composition containing a base oil and a thickener and used in a state of being attached to a chain, wherein the thickener is styrene- The content of the styrene-isoprene copolymer is 1% by mass or more and 10% by mass or less, when the whole chain lubricant composition containing the isoprene copolymer and polyethylene wax is 100% by mass. The content of the polyethylene wax is 1% by mass or more and 10% by mass or less, and the total content of the styrene-isoprene copolymer and the polyethylene wax is 11% by mass or less.

In the above lubricant composition for chains, the content of at least one of the styrene-isoprene copolymer and the polyethylene wax is preferably 1.5% by mass or more.

In the above lubricant composition for chains, it is preferable that the styrene-isoprene copolymer is a styrene-isoprene block copolymer and the polyethylene wax is a polymerizable polyethylene wax.

The chain lubricant composition is preferably used by lubricating the chain in the state of a diluted liquid diluted with a solvent.
A chain that solves the above problem is a chain to which the above lubricant composition for a chain is applied.

According to the present invention, it is possible to suppress stickiness on the outer surface of the chain even when the exudation resistance from the chain is improved.

FIG. 3 is an exploded perspective view schematically showing a part of the chain of the embodiment. The fragmentary sectional view which shows a chain schematically.

Hereinafter, an embodiment of the chain lubricant composition and the chain will be described.
The chain lubricant composition contains a base oil and a thickener. The lubricant composition for chains is used in a state of being attached to the chains.

As the base oil, at least one selected from mineral oil and synthetic oil is preferably used. Mineral oil can be selected from commercially available process oils and used. Examples of components of mineral oil include paraffin hydrocarbons such as liquid paraffin. Paraffin hydrocarbons have a paraffin carbon number (% CP) of 50 or more in a ring analysis by the ndM method.

Examples of synthetic oils include synthetic hydrocarbons (poly-α-olefin: PAO, cooligomers of ethylene and α-olefin, polybutene, etc.), esters, polyphenyl ethers, polyalkylene glycols, silicones, and fluorocarbons. .. Examples of the ester include hindered ester (dibasic acid ester, polyol ester, etc.), diester, and silicic acid ester.

As the base oil, one kind or two or more kinds can be used. The content of the base oil in the chain lubricant composition is preferably 70% by mass or more.
The thickener has a function of thickening the base oil by dispersing or dissolving it in the base oil. Thickeners include styrene-isoprene copolymers and polyethylene waxes.

The styrene-isoprene copolymer and the polyethylene wax are contained in the chain lubricant composition in the following contents, when the total amount of the chain lubricant composition is 100% by mass.

The content of the styrene-isoprene copolymer is 1% by mass or more and 10% by mass or less. The content of polyethylene wax is 1% by mass or more and 10% by mass or less. By containing each of the styrene-isoprene copolymer and the polyethylene wax in an amount of 1% by mass or more, stickiness on the outer surface of the chain can be suppressed and exudation resistance from the chain can be enhanced. However, in order to suppress stickiness on the outer surface of the chain, the total content of the styrene-isoprene copolymer and the polyethylene wax needs to be 11% by mass or less.

The content of at least one of the styrene-isoprene copolymer and the polyethylene wax is preferably 1.5% by mass or more. The styrene-isoprene copolymer is more preferably 1.5% by mass or more and 8% by mass or less, further preferably 2% by mass or more and 6% by mass or less.

The content of the polyethylene wax is more preferably 1.5% by mass or more and 8% by mass or less, and further preferably 2% by mass or more and 6% by mass or less.
The total content of the styrene-isoprene copolymer and the polyethylene wax is 2% by mass or more, more preferably 3% by mass or more, further preferably 4% by mass or more, and further preferably, It is 5 mass% or more.

Examples of the styrene-isoprene copolymer include a styrene-isoprene random copolymer and a styrene-isoprene block copolymer. The number average molecular weight of the styrene-isoprene copolymer is preferably in the range of 100,000 or more and 200,000 or less. The styrene-isoprene copolymer may be used alone or in combination of two or more.

The styrene-isoprene copolymer contained in the lubricant composition for chains in the above content is preferably a styrene-isoprene block copolymer. As the styrene-isoprene block copolymer, for example, a commercially available product such as "JSR SIS" manufactured by JSR Corporation, manufactured by Lubrizol, "Product name: Lubrizol 7306" can be used.

Examples of the polyethylene wax include polymerized polyethylene wax (Mitsui Chemicals Co., Ltd., Mitsui High Wax (registered trademark), 100P, 110P, 200P, 210P, 220P, 400P, 420P, 720P, 800P, Sanyo Chemical Industries ( Sun wax (registered trademark), 131-P, 151-P, 161-P, 165-P, 171-P, etc., degradable polyethylene wax (Mitsui Chemicals, Inc., Mitsui High Wax (registered) Trademark), NL100, NL200, NL500, NL800 and the like). One kind or two or more kinds of polyethylene wax can be used.

The polyethylene wax contained in the lubricant composition for chains with the above content is preferably a polymerized polyethylene wax. The number average molecular weight of the polymerizable polyethylene wax is preferably, for example, in the range of 1,000 or more and 8,000 or less.

The chain lubricant composition may contain a thickener other than those mentioned above, if necessary. Examples of thickeners other than the above include polymethacrylate, polyisobutylene, various waxes, and the like. The thickener containing the styrene-isoprene copolymer and polyethylene wax is preferably solid at room temperature (25°C).

The chain lubricant composition may contain a rust inhibitor, an oiliness agent, an extreme pressure agent, an antioxidant, an antifoaming agent, etc., if necessary.
The lubricant composition for chains is prepared by stirring a base oil and a thickener with a well-known stirrer. When preparing the lubricant composition for chains, it is preferable to heat it to the melting temperature of the thickener or higher.

Next, the chain will be described.
As shown in FIG. 1, the chain 11 of this embodiment is a roller chain, and has a structure in which an inner link 21 and an outer link 31 arranged adjacent to each other are rotatably connected.

The inner link 21 includes two inner plates 22 and 23 arranged to face each other, cylindrical bushes 24 and 25 that support the inner plates 22 and 23, and a cylindrical shape that is rotatably supported by the bushes 24 and 25. Rollers 26 and 27.

The inner plates 22 and 23 are held by being separated from each other by being connected by the bushes 24 and 25. More specifically, one end and the other end of the inner plate 22 in the direction along which the chains 11 are connected have through holes 22a and 22b. Also in the inner plate 23, the one end and the other end have through holes 23a and 23b.

The holes of the bushes 24 are opened through the through holes 22a and 23a to the outer surfaces of the inner plates 22 and 23 opposite to the facing surfaces. The holes of the bush 25 are also opened through the through holes 22b and 23b to the outer surface opposite to the surfaces of the inner plates 22 and 23 facing each other.

The outer link 31 has two outer plates 32 and 33 arranged to face each other, and two columnar pins 34 and 35 connecting the outer plates 32 and 33. The outer plates 32 and 33 are held by being separated from each other by being connected by the pins 34 and 35.

The pins 34 and 35 are respectively inserted into the bush 25 of the inner link 21 and the bush 24 of the inner link 21 arranged adjacent to the inner link 21. As a result, the adjacent inner links 21 and 21 are connected to each other via the outer link 31.

As shown in FIG. 2, gaps are formed between the outer peripheral surfaces of the pins 34 and 35 and the inner peripheral surfaces of the bushes 24 and 25. The outer peripheral surfaces of the pins 34 and 35 and the inner peripheral surfaces of the bushes 24 and 25 are lubricated using the chain lubricant composition. The chain 11 can be formed of steel, for example.

Next, the usage mode and action of the chain lubricant composition will be described.
In order to apply the chain lubricant composition to the chain 11, first, a diluent is prepared by diluting the chain lubricant composition with a solvent. Next, by dipping the chain 11 in this diluent, the diluent is supplied (oiled) between the outer peripheral surfaces of the pins 34 and 35 and the inner peripheral surfaces of the bushes 24 and 25. Subsequently, the diluted liquid supplied (lubricated) to the chain 11 is dried, that is, the solvent in the diluted liquid is volatilized to obtain the chain 11 lubricated with the lubricant composition for a chain.

The viscosity (25° C.) of the diluent for the chain lubricant composition is preferably 100 to 750 mPa·s, and more preferably 150 to 500 mPa·s.
The chain 11 is used, for example, for conveying articles or transmitting power. The chain 11 is used by being wound around a plurality of sprockets, for example. At this time, the space between the outer peripheral surfaces of the pins 34 and 35 and the inner peripheral surfaces of the bushes 24 and 25 is lubricated with the chain lubricant composition. At this time, since the chain lubricant composition contains the styrene-isoprene copolymer and the polyethylene wax as the thickener in the above-mentioned predetermined range, the outer peripheral surfaces of the pins 34 and 35 and the bushes 24 and 25 are not formed. Outflow of the lubricant composition for chains from between the inner peripheral surface and the inner peripheral surface is suppressed. Further, stickiness of the chain lubricant composition attached to the outer surface of the chain is also suppressed.

Next, the effect of this embodiment will be described.
(1) The chain lubricant composition contains a base oil and a thickener, and is used in a state of being attached to the chain. Thickeners include styrene-isoprene copolymers and polyethylene waxes. When the total amount of the lubricant composition for chains is 100% by mass, the content of the styrene-isoprene copolymer is 1% by mass or more and 10% by mass or less. The content of polyethylene wax is 1% by mass or more and 10% by mass or less. The total content of the styrene-isoprene copolymer and the polyethylene wax is 11% by mass or less.

According to this configuration, it is possible to suppress the stickiness of the outer surface of the chain even when the resistance to exudation from the chain is enhanced. As a result, the surroundings of the chain are less likely to become dirty during use, and dust is less likely to adhere to the chain. Therefore, the usage environment of the chain is improved and the maintenance of the chain itself is facilitated.

(2) The content of at least one of the styrene-isoprene copolymer and the polyethylene wax in the chain lubricant composition is preferably 1.5% by mass or more. In this case, stickiness on the outer surface of the chain or exudation from the chain can be further suppressed.

(3) The chain lubricant composition is preferably used by lubricating the chain in the state of a diluted liquid diluted with a solvent. In this case, since the diluent has a lower viscosity than the chain lubricant composition, for example, the chain lubricant composition is provided between the outer peripheral surfaces of the pins 34 and 35 and the inner peripheral surfaces of the bushes 24 and 25 of the chain. It becomes easy to refuel things.

(Example of change)
The above embodiment may be modified as follows.
The chain to which the lubricant composition for a chain is applied is not particularly limited, and for example, the lubricant composition for a chain can be applied to a bush chain in which the rollers 26 and 27 are omitted.

-The chain lubricant composition may be heated without being diluted with a solvent to reduce its viscosity, and then the chain may be lubricated. However, from the viewpoint of avoiding thermal decomposition of the styrene-isoprene copolymer as much as possible, it is preferable to lubricate the chain lubricant composition in the state of the diluted liquid diluted with the solvent as described above.

The lubricant composition for a chain may be applied to the chain 11 for so-called pre-lubrication, or may be applied to the chain 11 for maintenance of refueling during use of the chain 11.

Next, examples and comparative examples will be described.
(Examples 1 to 5, Reference Examples 6 and 7)
The chain lubricant composition of each example was prepared by mixing the components shown in Table 1. The unit of the numerical value indicating the content of each component in Table 1 is% by mass, and the “(A)+(B)” column in Table 1 indicates (A) a styrene-isoprene copolymer and (B). The total content with polyethylene wax is shown. In each example, as the base oil, refined mineral oil (poly-α-olefin type), (A) styrene-isoprene copolymer, styrene-isoprene block copolymer (number average molecular weight: 100,000 or more, 200, 000 or less), and (B) polyethylene wax, a polymerizable polyethylene wax (number average molecular weight: 5000) was used.

(Comparative Examples 1 to 7)
The chain lubricant composition of each comparative example was prepared by mixing the components shown in Table 2. The unit of the numerical value indicating the content of each component in Table 2 is% by mass, and the “(A)+(B)” column in Table 2 indicates (A) a styrene-isoprene copolymer and (B). The total content with polyethylene wax is shown. In each comparative example, as the base oil, refined mineral oil (poly-α-olefin type), (A) styrene-isoprene copolymer as styrene-isoprene block copolymer, and (B) polyethylene wax as polymerizable polyethylene wax. Was used.

<Resistance to seeping from chain>
Samples prepared by diluting the chain lubricant composition of each example with a solvent in a constant temperature bath at 120° C. and volatilizing the solvent until the content of the solvent in the diluent reaches 20% by mass. Prepared. The viscosities of the samples at this time are shown in Tables 1 and 2.

Next, each sample was applied to the filter paper using a jig having a circular hole with a diameter of 10 mm and a thickness of 5 mm. At this time, by applying the sample into the circular hole of the jig arranged on the filter paper, the size of the applied sample becomes the size of the circular hole of the jig. Subsequently, a test was performed in which the filter paper coated with the sample was left in a constant temperature bath at 40° C. for 72 hours, and then the diameter D1 (mm) of the base oil exuded was measured. Further, the same test was performed on the current oil (current chain lubricant composition), and the diameter D2 (mm) of the base oil exuded was measured.

The exudation resistance of the chain lubricant composition of each example was evaluated as follows.
Diameter D1 is less than 70% of diameter D2: very excellent (evaluation 4)
Diameter D1 is 70% or more and less than 80% of diameter D2: excellent (evaluation 3)
Diameter D1 is 80% or more and less than 90% of diameter D2: good (evaluation 2)
Diameter D1 is 90% or more of diameter D2: inferior (evaluation 1)
<Suppressing stickiness on the outer surface of the chain>
A chain lubricated with the lubricant composition for a chain of each example was prepared. After pressing a sheet (made of polyvinyl chloride resin, 10×50×t0.2 mm) at the center of the outer link of each chain, a digital force gauge (made by Nidec Shinpo Co., Ltd., FGP-0.2) was attached to the sheet. A peeling test of pulling up using the sheet was performed, and the maximum load L1 (N) until the sheet was peeled from the outer link was measured. Further, a peeling test was similarly performed on a chain supplied with the current oil (current chain lubricant composition), and the maximum load L2(N) was measured. The effect of suppressing stickiness of the lubricant composition for chains of each example was evaluated as follows.

Maximum load L1 is less than maximum load L2: Very good (evaluation 4)
The maximum load L1 is 100% or more and less than 110% of the maximum load L2: excellent (evaluation 3)
The maximum load L1 is 110% or more and less than 120% of the maximum load L2: good (evaluation 2)
The maximum load L1 is 120% or more of the maximum load L2: inferior (evaluation 1)
<Chain wear life>
A chain to which the lubricant composition for a chain of each example was supplied was endlessly wound around a pair of sprockets, and a continuous operation was performed to continuously rotate the chain under a load. The time T1 until the elongation of each chain reaches a predetermined value was measured. Further, a continuous operation was performed in the same manner with respect to a chain supplied with the current oil (current chain lubricant composition), and the time T2 until the elongation reached a predetermined value was measured.

The chain wear life of the lubricant composition for chains of each example was evaluated as follows.
Time T1 is time T2 or more: Very excellent (evaluation 4)
Time T1 is 90% or more and less than 100% of time T2: excellent (evaluation 3)
Time T1 is 80% or more and less than 90% of time T2: good (evaluation 2)
Time T1 is less than 80% of time T2: inferior (evaluation 1)

In the lubricant compositions for chains of Examples 1 to 5 and Reference Examples 6 and 7, the evaluation of the exudation resistance from the chain and the suppression of stickiness on the outer surface of the chain was 2 to 4. In the chain lubricant compositions of Examples 1 to 5 and Reference Examples 6 and 7, the chain wear life was evaluated to be 3 or 4.

The chain lubricant composition of Example 4 was superior to the chain lubricant composition of Reference Example 6 in the resistance to exudation from the chain. From this result, it is understood that the content of the (A) styrene-isoprene copolymer is preferably 1.5% by mass or more.

With the chain lubricant composition of Example 5, the same effect as that of the chain lubricant composition of Reference Example 7 was obtained with respect to resistance to seepage from the chain, and with respect to the suppression of stickiness on the outer surface of the chain, Reference Example was used. Results were obtained which were superior to the 7 chain lubricant composition. From this result, it is understood that the content of the (B) polyethylene wax is preferably 1.5% by mass or more.

The chain lubricant composition of Comparative Example 1 does not contain the (A) styrene-isoprene copolymer. The chain lubricant composition of Comparative Example 2 does not contain (B) polyethylene wax. In the lubricant composition for chains of Comparative Example 4, the content of the (A) styrene-isoprene copolymer is less than 1% by mass. With respect to the chain lubricant compositions of Comparative Examples 1, 2, and 4, the evaluation of the exudation resistance from the chain was 1.

When an excessive amount of the (A) styrene-isoprene copolymer was contained as in the chain lubricant composition of Comparative Example 3, the evaluation of the stickiness control on the outer surface of the chain was 1. When the total content of the (A) styrene-isoprene copolymer and the (B) polyethylene wax exceeds 11% by mass as in the lubricant composition for chains of Comparative Example 5, the stickiness of the outer surface of the chain is suppressed. The evaluation was 1.

The lubricant composition for chains of each example in which (A) styrene-isoprene copolymer and (B) polyethylene wax were used together as a thickener was obtained from Comparative Examples 6 and 7 using polyisobutylene as a thickener. It can be seen that it is more advantageous than the lubricant composition for chains in terms of suppressing stickiness on the outer surface of the chain.

11... Chain, 21... Inner link, 22, 23... Inner plate, 22a, 22b, 23a, 23b... Through hole, 24, 25... Bush, 26, 27... Roller, 31... Outer link, 32, 33... Outer plate , 34, 35... Pins.

Claims (5)

A lubricant composition for a chain containing a base oil and a thickener, which is used in a state of being attached to a chain,
The thickener includes styrene-isoprene copolymer, and polyethylene wax,
When the total amount of the chain lubricant composition is 100% by mass,
The content of the styrene-isoprene copolymer is 1.5 % by mass or more and 10% by mass or less,
The content of the polyethylene wax is 1.5 % by mass or more and 10% by mass or less,
The lubricant composition for chains, wherein the total content of the styrene-isoprene copolymer and the polyethylene wax is 11% by mass or less. The lubricant composition for chains according to claim 1, which does not contain lithium soap . The chain lubricant composition according to claim 1 or 2, wherein the styrene-isoprene copolymer is a styrene-isoprene block copolymer, and the polyethylene wax is a polymerized polyethylene wax. object. The chain lubricant composition according to any one of claims 1 to 3, wherein the chain lubricant composition is used by supplying oil to the chain in a state of a diluted liquid diluted with a solvent. Composition. A chain to which the lubricant composition for chains according to any one of claims 1 to 4 is applied.