KR20210002240A - A grease composition for automobile switch - Google Patents

Abstract

The present invention relates to a grease composition for a highly-functional vehicle switch applied to a switch device which performs functions of a vehicle steering wheel front direction indicator, a headlight, a fog lamp, and a wiper. More specifically, the present invention relates to a grease composition for a vehicle switch, comprising 85 to 95 wt% of base oil, 5 to 15 wt% of a thickener, and 0.1 to 1 wt% of an antioxidant.

Description

Grease composition for automotive switches {A GREASE COMPOSITION FOR AUTOMOBILE SWITCH}

The present invention relates to a grease composition for an automobile switch, and more particularly, to a grease composition for a highly functional automobile switch applied to a switch device that performs a vehicle steering wheel front direction indicator, a headlight, a fog lamp, and a wiper function.

There are many fields that are not suitable for applying liquid lubricants because the greasing point of the liquid lubricant is relatively "drift". These unsuitable areas are particularly those that do not include rolling and sliding bearings, open gears, metal cables and chain drives, and generally no sealing systems.

For these applications, lubricant greases of solid or semi-fluid material are used to disperse a thickener in a liquid lubricant and add additives that provide specific properties.

Many of the lubricant greases are made with fatty acid metal salt type thickeners. After dissolving the fatty acid in the base oil at a relatively high temperature, a suitable metal hydroxide is added. The water, formed during the reaction, is evaporated by baking and then cooled for a defined period to form a soap lattice.

Metal compounds suitable for making greases are lithium hydroxide, sodium hydroxide, calcium hydroxide, barium hydroxide, titanium hydroxide or aluminum hydroxide. Long-chain fatty acids of about C14 to C28, mainly C18, are generally derived from vegetable oils (eg castor oil) or animal oils (eg tallow). These long chain fatty acids can be hydrogenated. The most known derivative is 12-hydroxystearic acid, derived from ricinoleic acid.

Short-chain fatty acids typically containing 6 to 12 carbon atoms, such as azelaic acid, etc., can be used with long-chain fatty acids. This forms a so-called complex grease.

Soap forms a fibrous structure that holds the lubricant oil. Aluminum soap has a spherical gel structure.

Other inorganic thickeners such as bentonite, silica gel, etc. may be used.

Polycarbamide (polyurea) is also a viscosity enhancer.

This thickener is generally used in special applications such as high temperature grease.

For certain applications, such as lubricated rolling bearings, and also machine tool slide rails, or centralized greasing systems in automobiles and transmissions, a low coefficient of friction of the grease is desirable. , This can increase the efficiency of the system and save fuel ("ecofuel" or "fuel saving" nature).

These greases must be sufficiently consistent so that they do not work outside the greasing point, and must serve to reduce wear and prevent seizing.

Patent application JP 55082196 discloses a specific grease composition in which a solid lubricant in particulate form is added as an additive to improve the coefficient of friction and prevent seizing of the system.

It is known that solid lubricants, in particular polytetrafluoroethylene (PTFE), must be added to the grease in high amounts, at least 5% by mass, or 10% by mass, sometimes up to 40% by mass, in order to be effective.

It is also known that the anti-friction and anti-wear properties of these particulate solids are improved when the particles are nanometer sized. Patent application WO 2008/069936 discloses that a solid lubricant is used in the form of nanoparticles having a diameter of less than 500 nm in a liquid lubricant or grease to improve wear resistance and lubricity. However, the amount of solid lubricant required to obtain a significant effect is still significant, about 20% by mass, 15% by mass or more.

This poses a cost issue of the formulation, and such high content can also spoil the other properties of the lubricant and grease, and can significantly affect the viscosity, or consistency, with respect to the grease.

For example, such nanoparticulate solid lubricants in polytetrafluorethylene (PTFE) are used as described in patent application US 2005/0124504, organomolybdenum, zinc dithiophosphate to improve lubrication. (zinc dithiophosphate), a boron compound type compound, can be added to the motor oil in an amount of 0.01 to 10% by mass.

However, it appears that the prior art did not adjust the overall parameters of obtaining the maximum antifriction effect of solid nanoparticles in the lubricant or grease, in particular the parameters determining the somewhat adequate dispersion of these particulate solids in the lubricant or grease. It will be demonstrated that these parameters differ substantially between one medium and another, such as between grease and liquid lubricant, and depend on the properties of the particles used, of the base, and of the thickener used.

Therefore, there is a need for a grease composition in which the antifriction effect of solid nanoparticles is improved. Thus, there is also a need for such a grease with improved wear resistance.

The technical problem to be solved by the present invention is to provide a grease composition for a highly functional automobile switch that has excellent wear resistance and is applied to a switch device that performs a vehicle steering wheel front direction indicator, a headlamp, a fog lamp, and a wiper function.

The grease composition for a vehicle switch according to the present invention for solving the above-described technical problem is composed of 85 to 95% by weight of a base oil, 5 to 15% by weight of a thickener, and 0.1 to 1% by weight of an antioxidant.

And in the present invention, the base oil is preferably composed of synthetic oil and mineral oil.

In addition, in the present invention, the synthetic oil is preferably made of a mixture of homopolymer and polybutylene.

In addition, in the present invention, the homopolymer is 1-Decene, homopolymer, and hydrogenated, and is preferably mixed with the polybutylene in a weight ratio of 3:1.

In addition, in the present invention, it is preferable that the synthetic oil is further mixed with a polyolefin synthetic oil.

In addition, in the present invention, the polyolefin-based synthetic oil is preferably a 1-Butene-propylene copolymer.

In addition, in the present invention, the mineral oil is preferably hydrogenated heavy paraffinic.

In addition, the thickener in the present invention is preferably a metal soap-based thickener.

In addition, in the present invention, the metal soap-based thickener is preferably 12-Hydroxyoctadecanoic acid monolithium salt: Lithium 12-hydroxystearate.

In addition, the antioxidant in the present invention is 2,6-di-t-butyl-4-methylphenol, 2, 6-di-t-butyl-paracresol, P, P'-dioctyldiphenylamine, N-phenyl It is preferable to contain -α-naphthylamine and phenothiazine.

The grease composition for automobile switches according to the present invention satisfies physical properties such as water resistance and mechanical stability at the same time compared to the conventional grease composition, and particularly has excellent friction reduction and is effective for use as a grease for automobiles and aerospace.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The grease composition for a vehicle switch according to the present embodiment comprises 85 to 95% by weight of a base oil, 5 to 15% by weight of a thickener, and 0.1 to 1% by weight of an antioxidant.

First, the base oil is an oil that is the basis of the grease composition for a vehicle switch according to the present embodiment, and is included to minimize the change in viscosity of the grease according to temperature, mineral oil, synthetic oil, and natural oil ( Natural oil). In this embodiment, the base oil is preferably mixed in an amount of 85 to 95% by weight based on the total grease composition.

In this embodiment, it is preferable that the base oil specifically includes synthetic oil and mineral oil, since it improves friction resistance. In particular, the synthetic oil is preferably made of a mixture of homopolymer and polybutylene. The homopolymer is preferably 1-Decene, homopolymer, or hydrogenated, and more preferably mixed with the polybutylene in a weight ratio of 3:1.

Meanwhile, in this embodiment, it is preferable that the synthetic oil is further mixed with a polyolefin-based synthetic oil, since it can increase the affinity and solubility with the additive. It is preferable that the polyolefin-based synthetic oil is specifically 1-Butene-propylene copolymer.

Next, the mineral oil may be selected from the group consisting of paraffinic, naphthine, aromatic hydrocracking oil, and gas-to-liquid (GTL) oil, and gas liquefaction (GTL) refers to a method of making gas into a liquid or natural It is produced by the method of producing fuel from gas. In particular, it is preferable that the mineral oil is hydrogenated heavy paraffinic in this embodiment.

Next, the thickener is mixed to increase the viscosity of the grease composition according to the present embodiment, and is preferably mixed in a ratio of 5 to 15% by weight of the total grease composition. If the content of the thickener is less than 5% by weight, penetration increases or oil separation (storage stability) becomes severe, and when the content of the thickener exceeds 15% by weight, the fluidity is Since a problem of deterioration occurs, it is preferable to use a thickener within the above range.

In addition, since the grease composition according to the present embodiment does not require high heat resistance, the thickener is preferably a metal soap thickener. The metal soap-based thickener includes fatty acids and metal hydroxides. As the fatty acid, carboxylic acids having 12 to 24 carbons may be used, and metal hydroxides such as lithium, calcium, aluminum, barium and sodium are used as metal hydroxides.

Specifically, in this embodiment, the metal soap-based thickener is preferably 12-Hydroxyoctadecanoic acid monolithium salt: Lithium 12-hydroxystearate.

Next, the antioxidant is an additive added to improve the function of the grease composition, and is preferably mixed in an amount of 0.1 to 1% by weight based on the total composition of the grease composition according to the present embodiment. When the content of the antioxidant exceeds 1% by weight, the antioxidant effect is no longer increased, and when the content of the antioxidant is less than 0.1% by weight, there is a problem in that the antioxidant effect is lowered. It is preferable to use antioxidants within.

In this embodiment, the antioxidant is specifically, 2,6-di-t-butyl-4-methylphenol, 2, 6-di-t-butyl-paracresol, P, P'-dioctyldiphenylamine, N -Phenyl-α-naphthylamine, phenothiazine, and the like.

Meanwhile, nanodiamonds may be further added as an additive to the grease composition for an automobile switch according to the present embodiment. Most of the nanodiamonds have a particle size distribution in the range of 100 to 1000 nm, and the function of the grease composition is improved only when an amount of 1 wt% or more is added. The nanodiamond particles added should not be deposited on the bottom of the oil tank in order to form a flexible metal film on the surface of the tribometer to reduce friction and abrasion of the machine, and are evenly distributed throughout the lubricant by Brownian motion In order to have possible dispersibility, it is essential that the particle shape is spherical.

The nanodiamonds mixed with the grease composition additive should be capable of super-dispersing nanoscales of a size of 100 nm or less, which can exhibit performance even in a content of 0.1% or less, and should maintain a dispersion stability period. In this example, primary nanodiamond particles manufactured by the explosion method are used. The detonation nanodiamond produced by the explosion method is a type of nanocarbon along with carbon nanotubes (CNT), graphite, graphene, and fullerene.

The nanodiamond crystals formed immediately after the explosion are aggregated and exist in the Soot mixed with various impurities, which are the residues of the explosion. When other impurities are removed while purifying this process through several processes, only nanodiamond particles characterized by a diamond core and a graphite layer on the surface remain.

Nanodiamonds exist in the form of crystals composed of sp3 hybrid orbital functions, but since the surface has an sp2 orbital structure, the center retains the diamond characteristics, but the surface is highly reactive, so impurities exist around the surface. Therefore, in order to remove impurities on the surface of the nanodiamond and increase its applicability, a method of oxidizing the surface has been developed.

However, even after such treatment, the nanodiamonds exist as aggregates having various sizes in the solution due to the strong interaction between the nanodiamonds and the highly reactive oxygen groups. Therefore, the compound bonds present on the surface of the particles not only contribute to stabilizing the surface of the nanodiamond particles, but also various functional groups can be attached to the surface of the nanodiamond through new chemical reactions.

Claims (10)

A grease composition for automotive switches comprising 85 to 95% by weight of base oil, 5 to 15% by weight of a thickener, and 0.1 to 1% by weight of an antioxidant. The method of claim 1,
The base oil is a grease composition for a vehicle switch, characterized in that it comprises synthetic oil and mineral oil. The method of claim 2,
The synthetic oil is a grease composition for automobile switches, characterized in that consisting of a mixture of homopolymer and polybutylene. The method of claim 3,
The homopolymer is 1-Decene, homopolymer, hydrogenated, and is mixed with the polybutylene in a weight ratio of 3:1. The method of claim 3,
Grease composition for automobile switches, characterized in that the synthetic oil is further mixed with a polyolefin-based synthetic oil. The method of claim 5, wherein the polyolefin-based synthetic oil,
Grease composition for automotive switches, characterized in that 1-butene-propylene copolymer. The method of claim 2,
The mineral oil is a grease composition for automobile switches, characterized in that hydrogenated heavy paraffinic. The method of claim 1,
The grease composition for automobile switches, characterized in that the thickener is a metal soap-based thickener. The method of claim 8, wherein the metallic soap-based thickener,
12-Hydroxyoctadecanoic acid monolithium salt: A grease composition for automotive switches, characterized in that it is Lithium 12-hydroxystearate. The method of claim 1, wherein the antioxidant,
2,6-di-t-butyl-4-methylphenol, 2, 6-di-t-butyl-paracresol, P, P'-dioctyldiphenylamine, N-phenyl-α-naphthylamine, phenothi A grease composition for automotive switches comprising azine.