KR102211666B1 - Rubber composition having improved lubricity and method for producing the composition - Google Patents

Abstract

The present invention relates to a rubber composition with improved lubricity and a method for manufacturing the composition, wherein when assembling a rubber composition used for a vehicle bushing into a housing, a rubber with improved lubricity for easy assembly without the use of separate press-fitting oil and lubricant Regarding the composition and the method for preparing the composition, a reinforcing agent, a vulcanizing agent, a vulcanization accelerator, and an activator are added to the raw rubber, and an additional additive to show the effect of lubricity is mixed with the mixture to maximize the effect of lubricity. It relates to a composition and a method for preparing the composition.

Description

Rubber composition having improved lubricity and method for producing the composition}

The present invention relates to a rubber composition with improved lubricity and a method for manufacturing the composition, wherein when assembling a rubber composition used for a vehicle bushing into a housing, a rubber with improved lubricity for easy assembly without the use of separate press-fitting oil and lubricant It relates to a composition and a method of preparing the composition.

First of all, looking at the prior art,

The anti-vibration rubber parts for vehicles play an important function in suppressing vibration and noise generated while driving and improving the comfort of the vehicle.

For the past several years, studies related to long-term durability performance and damage analysis of vehicles have been actively conducted, and in recent years, expectations for driving quietness are increasing with interest in ride comfort and steering stability.

Among the anti-vibration rubber parts, the suspension bushing is a part applied to the vehicle chassis arm-assembly part, and depending on which material is applied, the vehicle ride comfort and handling (R&H) performance can be greatly improved.

Accordingly, research and development is underway on materials that enable not only new car performance but also to maintain the same performance as the initial stage even after long-term driving, and simultaneously improve the initial quality index (IQS index) and durability quality index (VDS index). .

In addition, when assembling a rubber composition used for a vehicle bushing into a housing, the lubricity effect for assembly appears differently depending on the component of the raw rubber in terms of assembly properties.

NR rubber has a high assembly load even when self-lubricating agent is added, so assembly is not smooth due to the spring back phenomenon during assembly.

Therefore, conventionally,'EPDM rubber composition for outdoor insulation' of registration number 10-0307365,'natural rubber composition for vehicles' of publication number 10-2018-0058299, and'for automobiles with excellent heat resistance' of registration number 10-1847372. Although a rubber bushing composition and a method for manufacturing a rubber bushing for an automobile using the same are disclosed, the situation is still not improved with respect to the above problems.

The present invention was devised to solve the above problems of the prior art, by adding a reinforcing agent, a vulcanizing agent, a vulcanization accelerator, and an activator to the raw rubber, and mixing additional additives to exhibit the lubricity effect to the mixture. It was completed as a technical task with an emphasis on providing a rubber composition that maximizes the lubricity effect and a method for manufacturing the composition.

Accordingly, the present invention provides a rubber composition applied to a vehicle bushing, comprising: a terpolymer rubber (EPDM); A reinforcing agent added based on 100 Phr of the rubber but added in the range of 80 to 130 Phr; A vulcanizing agent added in the range of 0.5 to 2 Phr; Vulcanizing aid added in the range of 3 to 7 Phr; A vulcanization accelerator added in the range of 0.5 to 3 Phr; Activator added in the range of 1 to 2 Phr; Process oil added in the range of 20 to 50 Phr; Anti-aging agents added in the range of 1 to 4 Phr and lubricants added in the range of 1 to 13 Phr; It features a rubber composition with improved lubricity, characterized in that it comprises a.

In addition, a method for manufacturing a rubber composition applied to a vehicle bushing, comprising: a first step of injecting a terpolymer rubber (EPDM), a reinforcing agent, and a process oil into a rubber mixing device to complete a first compound; A second step of adding a vulcanization aid, an activator, an anti-aging agent, and a lubricant to the first formulation to complete the second formulation; A third step of cooling the second mixture; And a method for producing a rubber composition with improved lubricity, characterized in that the rubber composition is completed by adding a vulcanizing agent and a vulcanization accelerator to the cooled formulation.

According to the present invention, a rubber composition with improved lubricity and a method for producing the composition, in preparing a rubber bushing composition for a vehicle, a reinforcing agent, a vulcanizing agent, a vulcanization accelerator and an activator are added to EPDM rubber to add a reinforcing agent, a vulcanization accelerator, and an activator. In addition to the above ingredients, each compound can be added to rubber, reinforcing agent, and process oil to maximize the effect of lubrication.When assembling the rubber composition to the housing, it is possible to assemble the rubber composition without using separate press-fitting oil and lubricant. It is an invention with great effects such as ease.

Hereinafter, a preferred configuration and operation of the present invention for achieving the above object will be described with reference to the accompanying contents.

priority,

The rubber composition having improved lubricity according to the present invention,

A rubber composition applied to a vehicle bushing, comprising: terpolymer rubber (EPDM); A reinforcing agent added based on 100 Phr of the rubber (EPDM) but added in a range of 80 to 130 Phr; A vulcanizing agent added in the range of 0.5 to 2 Phr; Vulcanizing aid added in the range of 3 to 7 Phr; A vulcanization accelerator added in the range of 0.5 to 3 Phr; Activator added in the range of 1 to 2 Phr; Process oil added in the range of 20 to 50 Phr; Anti-aging agents added in the range of 1 to 4 Phr and lubricants added in the range of 1 to 13 Phr; Consists of

In the present invention, the reinforcing agent is used as carbon black,

The vulcanizing agent uses sulfur,

Zinc oxide is used as a vulcanization aid,

As the vulcanization accelerator, zinc-ethylphenyldithiocarbamate and dibenzothiyl disulfide are selectively used singly or simultaneously,

Stearic acid is used as the activator,

Paraffin oil is used as the process oil,

As an antioxidant, 2,2,4-trimethyl-1,2 dihydroquinoline is used,

Lubricant uses unsaturated fatty acid amide, titanium potassium fiber, and synthetic wax.

In the case of the unsaturated fatty acid amide, the first unsaturated fatty acid amide and the second unsaturated fatty acid amide may be used selectively or simultaneously.

In addition, unsaturated fatty acid amide, titanium potassium fiber, and synthetic wax, which are lubricants, may be used singly or may be used in combination.

When describing each of the above components additionally,

Rubber (EPDM),

It became a terpolymer with ethylene, propylene, and a small amount of non-conjugated dienes that were hooked on the side chains of the fully saturated main chain to provide unsaturation.

As the non-conjugated diene used as the third component, dicyclopentadiene (DCPD), 1,4-hexadiene (1,4-HD), 5-ethylene norbornene (ENB), and the like are used.

EPDM with ENB has a great activity in sulfur vulcanization, and its reactivity increases as the ENB content increases.

EPDM has excellent ozone resistance, weather resistance, chemical resistance, and excellent electrical insulation.

In the present invention, a terpolymer EPDM material prepared using ethylene norbornene (ENB) as a diene monomer is used.

In general, EPDM containing ENB has a composition ratio of 40 to 80% by weight of ethylene monomer and 2 to 10% by weight of ENB monomer.

As the EPDM polymer used in the present invention, two types of EPDM containing oil and EPDM containing no oil are used.

The oil-containing EPDM is prepared by blending an extended oil during the EPDM manufacturing process.

Specifically, the monomer is polymerized to have a composition ratio of 50 to 80% by weight of ethylene monomer and 4 to 7% by weight of ENB monomer, and oil is added before adding oil during the EPDM polymerization process or removing volatile substances after polymerization. It can be prepared by adding.

For EPDM containing oil, it is preferable to use a polymer containing oil in the range of 50 to 100 parts by weight based on 100 parts by weight of the EPDM.

If a polymer having an oil content of less than 50 parts by weight is used, processing performance may be deteriorated, and if it exceeds 100 parts by weight, the viscosity may be lowered and processing may be difficult.

As the oil, a paraffinic aliphatic oil or a naphthalene-based aromatic oil commonly used in the art may be used, but a paraffinic oil is preferably used.

EPDM, which does not contain oil, uses a slightly higher EPDM with an ethylene norbornene (ENB) content of 7-10% by weight.

Carbon black used as a reinforcing agent,

It plays a role in improving the physical and mechanical properties of rubber when mixing rubber.

As the reinforcing agent in the present invention, carbon black, inorganic fillers, organic fillers, and the like are usually used as those blended in rubber.

Examples of the carbon black include furnace blacks such as HAF carbon black, MAF carbon black, FEF carbon black, and SRF carbon black, and thermal blacks such as MT carbon black.

Sulfur used as a vulcanizing agent,

When the rubber is heated to an appropriate temperature, it serves to create a crosslink between the polymer chains.

Zinc oxide used as a vulcanizing aid,

It acts together with the vulcanizing agent to increase the vulcanization rate, thereby lowering the vulcanization temperature, shortening the vulcanization time, and also plays a role to complete the accelerating effect of the vulcanization accelerator.

Zinc-ethylphenyldithiocarbamate and dibenzothiyl disulfide, which are used as vulcanization accelerators, increase the vulcanization rate to shorten the vulcanization time and increase physical properties.

Zinc-ethylphenyldithiocarbamate has a melting point of 105°C or higher when used, an effective super accelerator, non-polluting, and excellent storage stability.

In addition, dibenzothiyl disulfide has a critical temperature of 130°C or higher, is the most widely used accelerator, and has excellent scorch stability.

Vulcanization accelerators can contribute to lowering the production cost in the process of producing parts by increasing the crosslinking speed, and can contribute to quality improvement by controlling the crosslinking density by preventing scorch when molding into parts.

If too little of the vulcanization accelerator is used, there is a problem of deterioration of the molding quality due to the occurrence of scorch during molding, and there is a problem that the production time is lengthened, and if too much is used, there is a problem that the moldability is deteriorated due to short processing time.

Stearic acid used as an activator,

It serves to improve the processability and vulcanization properties of rubber compounding.

If the content is too small or not, the crosslinking reaction is slow, and if the content is too large, the crosslinking reaction is accelerated, resulting in a problem in productivity.

Paraffin oil used as process oil,

It plays a role in improving processability and low temperature properties in the rubber manufacturing process.

As the process oil used to improve the processability of EPDM, those commonly used for rubber or thermoplastic elastomers can be used.

For example, a petroleum-based softener, a fatty oil-based softener, and an ester plasticizer may be mentioned.

In general, it is preferable to use the same paraffinic oil used in the manufacturing process of the EPDM polymer containing oil.

In general, the absolute value of the difference in the solubility parameter between the polymer and the process oil should be within 0.3 (cal/cm ³ ) ^1/2 , and the solubility parameter of EPDM is 7.9 (cal/cm ³ ) ^1/2 . , Paraffin oil 7.9 (cal/cm ³ ) ^1/2 or naphthenic oil 8.1 (cal/cm ³ ) ^1/2 .

If the absolute value of the difference in the solubility parameter value is exceeded, compatibility with EPDM may deteriorate, resulting in defects in which extraction occurs in the rubber compound.

2,2,4-trimethyl-1,2 dihydroquinoline used as an anti-aging agent,

It can extend the life of rubber products by slowing down the rate of deterioration due to aging, and protects rubber from oxygen, ozone, heat, sunlight, radiation and moisture.

When explaining unsaturated fatty acid amide and titanium potassium fiber and synthetic wax used as lubricants,

The first unsaturated fatty acid amide,

By imparting lubricity to the rubber, it reduces the coefficient of friction outside the rubber, is composed of oleamide, and can exhibit a fast moving speed.

The second unsaturated fatty acid amide,

By imparting lubricity to the rubber, it reduces the coefficient of friction outside the rubber, and is composed of erucamide, and has excellent heat stability.

Titanium potassium fiber,

It has high strength and rigidity and plays a role in improving the friction performance of rubber.

Synthetic wax,

As a dissolved synthetic wax derived from hydrogenated castor oil, it plays a role in creating a low coefficient of friction on the rubber surface.

The first compound, the second compound, and the third compound may be added to the rubber composition selectively or in mutual mixing to maximize the effect of improving performance and lubricity for the rubber composition.

The first compound is

The rubber is added based on 100 Phr, but includes a poly-transoctenamer rubber added in the range of 8 to 12 Phr, and an aliphatic hydrocarbon resin added in the range of 2 to 5 Phr. .

The polytransoctenamer rubber serves to improve dynamic properties, heat resistance, abrasion resistance, molding workability, dispersion properties, etc. by reducing internal heat generation in terms of modulus improvement and fatigue durability.

The aliphatic hydrocarbon resin is effective in blending the EPDM polymer, and aids in the processing of the next step by securing the compound's viscosity drop and network structure.

In addition, it helps to disperse chemicals such as reinforcing agents by making the polymer uniform.

The second compound is

The reinforcing agent is added based on 100 Phr, and includes high styrene resin added in the range of 15 to 25 Phr.

When the high-styrene resin is compounded with rubber, it acts as a plasticizer at high temperature to improve processability, and improves wear resistance, tear resistance, and bending resistance.

The third compound is

Resorcinol formalde-hyde resin added based on 100 Phr of the process oil, but added in the range of 2 to 4 Phr, and hexamethylenetetramine added in the range of 1 to 2 Phr. do.

The resorcinol formaldehyde resin improves the adhesion between the rubber and the metal, and hexamethylenetetramine binds with formaldehyde to improve the adhesion between the rubber and the metal.

In addition, the method for producing a rubber composition according to the present invention,

A method for producing a rubber composition applied to a vehicle bushing, comprising: a first step of injecting a terpolymer rubber (EPDM), a reinforcing agent, and a process oil into a rubber mixing device to complete a first compound; A second step of adding a vulcanizing aid, an activator, an anti-aging agent, and a lubricant to the first formulation to complete the second formulation; A third step of cooling the second mixture; A vulcanizing agent and a vulcanization accelerator are added to the cooled formulation to complete the rubber composition.

In the rubber composition manufacturing method, the first compound, the second compound, and the third compound may be added selectively or mixed with each other in order to maximize the effect of improving performance and lubricity for the rubber composition.

The first compound is

The rubber (EPDM) includes a polytransoctenamer rubber and an aliphatic hydrocarbon resin.

The mixing of the rubber and the first compound,

Rubber and polytransoctenamer rubber are firstly mixed,

The aliphatic hydrocarbon resin is secondarily mixed with the mixed mixture.

The second compound is

High styrene resin is included in the reinforcing agent.

The mixing of the reinforcing agent and the second compound,

The reinforcing agent and high styrene resin are mixed.

The third compound is

Resorcinol formaldehyde resin and hexamethylenetetramine are included in the process oil.

The mixing of the rubber and the third compound,

Rubber and resorcinol formaldehyde resin are firstly mixed,

Hexamethylenetetramine is secondarily mixed with the mixed mixture.

According to the present invention as described above, in preparing a rubber bushing composition for a vehicle, a reinforcing agent, a vulcanizing agent, a vulcanization accelerator, and an activator were added to the EPDM rubber to increase the lubricity for the bushing rubber composition. , By adding each compound to the reinforcing agent and process oil, the lubricity effect can be maximized, and when assembling the rubber composition to the housing, assembly is easy without using separate press-fitting oil and lubricant.

Claims (3)

Terpolymer rubber (EPDM), added based on 100 Phr of the rubber (EPDM), but added in the range of 80 to 130 Phr, a reinforcing agent using carbon black, and a vulcanizing agent that is added in the range of 0.5 to 2 Phr and using sulfur Wow, a vulcanization aid that is added in the range of 3 to 7 Phr and uses zinc oxide, and is added in the range of 0.5 to 3 Phr, and zinc-ethylphenyldithiocarbamate and dibenzotiyl disulfide are selectively used alone, or Vulcanization accelerator used at the same time, added in the range of 1 ~ 2 Phr, activator using stearic acid, added in the range of 20 ~ 50 Phr, process oil using paraffin oil, and added in the range of 1 ~ 4 Phr, 2,2 In the rubber composition applied to a vehicle bushing consisting of an anti-aging agent using ,4-trimethyl-1,2 dihydroquinoline and a lubricant that is added in the range of 1 to 13 Phr and uses unsaturated fatty acid amide, titanium potassium fiber, and synthetic wax ,
The first compound, the second compound and the third compound are added to the rubber composition based on 100 Phr of terpolymer rubber (EPDM).
In the first compound,
Poly-transoctenamer rubber added in the range of 8 to 12 Phr and aliphatic hydrocarbon resin added in the range of 2 to 5 Phr,
In the second compound,
High styrene resin added in the range of 15 ~ 25 Phr is included,
In the third compound,
Rubber with improved lubricity, characterized by containing resorcinol formalde-hyde resin added in the range of 2 to 4 Phr and hexamethylenetetramine added in the range of 1 to 2 Phr. Composition.
delete The first step of completing the first blend by adding terpolymer rubber (EPDM), reinforcing agent and process oil to the rubber blending device, and the second blend by adding a vulcanizing aid, activator, anti-aging agent and lubricant to the first blend. In the second step of completing and, in the method for producing a rubber composition applied to a bushing for a vehicle to complete a rubber composition by adding a vulcanizing agent and a vulcanization accelerator to the second compound,
After the second step, a third step of cooling the second blend is configured,
In the first blend of the first step,
A third compound containing resorcinol formaldehyde resin and hexamethylenetetramine are added to the first compound containing polytransoctenamer rubber, an aliphatic hydrocarbon resin, and a second compound that is a high styrene resin, and a process oil,
In the terpolymer rubber (EPDM), a polytransoctenamer rubber of a first compound and a resorcinol formaldehyde resin as a third compound are first mixed,
The aliphatic hydrocarbon resin of the first compound and hexamethylenetetramine, which is a third compound, are secondarily mixed in the first mixture,
The method for producing a rubber composition with improved lubricity, characterized in that the reinforcing agent is mixed with a second compound of high styrene resin.