KR101794916B1 - Rubber composition and Tire comprising rubber composition - Google Patents

Abstract

Provided are a rubber composition and a tire comprising the rubber composition, wherein the rubber composition comprises: raw rubber comprising at least one selected from natural rubber and synthetic rubber; an inorganic filler comprising silica; and a softener comprising a triterpenoid compound containing a plurality of fused aliphatic rings.

Description

Rubber compositions and tires comprising them [0002]

Rubber compositions and tires comprising the same.

When the filler is reinforced in the rubber composition having a high viscosity in the rubber composition, the softening agent is used to improve the workability because the flexibility of the compounded rubber is lowered. As the softening agent, an oil acting as a lubricant between rubber molecules can be used. The oil used as a softener in the tire rubber composition may be paraffinic oil, aromatic oil, naphthenic oil, or the like. As the softening agent, a chemical peptizer, a processing aid, or a polymer having a low molecular weight can be used. For example, Korean Patent Publication No. 2004-0055029 discloses a rubber composition comprising paraffin oil as a softener.

In particular, a rubber compound containing an aromatic oil has excellent processability such as extrusion and rolling, and can minimize the change in physical properties, and thus is used typically among the above-mentioned oils.

However, a new emollient that can replace aromatic oils containing polycyclic aromatic compounds (PCA) due to environmental regulations and other suspected carcinogens is required.

One aspect is to provide a novel composition of a rubber composition comprising a new softener.

Another aspect is to provide a tire comprising the rubber composition.

According to one aspect,

A raw rubber comprising at least one selected from natural rubber and synthetic rubber;

An inorganic filler comprising silica; And

A softener comprising a triterpenoid compound containing a plurality of fused aliphatic rings,

There is provided a rubber composition for a tire comprising a dammar compound obtained from a dammar resin in which a triterpenoid compound containing a plurality of fused aliphatic rings is obtained.

According to another aspect,

There is provided a tire comprising a tread rubber made of the above-mentioned rubber composition.

According to one aspect there is provided a triterpenoid compound containing a plurality of fused aliphatic rings wherein the triterpenoid compound containing a plurality of the fused aliphatic rings is selected from the group consisting of the extrusion performance, the tensile properties and the braking characteristics of the rubber composition can be improved by including the dammar compound obtained from the dammar resin.

1 is a view schematically showing the structure of a tire according to one embodiment.

Hereinafter, a rubber composition for a tire and a tire will be described in more detail in an exemplary embodiment.

The inventive concepts disclosed herein are capable of various modifications and various implementations, and specific implementations are described in detail in the detailed description and, where necessary, specific implementations are illustrated in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The effect and features of the inventive concepts herein, and how to accomplish them, will become apparent with reference to the embodiments described in detail below with reference to the drawings. However, the inventive concept of the present invention is not limited to the embodiments disclosed below, but may be embodied in various forms.

In the following embodiments, the terms first, second, etc. are used for the purpose of distinguishing one element from another element, rather than limiting.

In the following implementations, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

In the following implementations, terms such as comprise, or having are meant to imply the presence of features, or components, that are described in the specification and do not preclude the possibility that one or more other features or components may be added.

If one embodiment is otherwise feasible, the particular process sequence may be performed differently from the sequence described. For example, two processes that are described in succession may be performed substantially concurrently, and may be performed in the reverse order of the order described.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. .

In the drawings, components may be exaggerated or reduced in size for convenience of explanation. For example, the sizes and thicknesses of the individual components shown in the drawings are arbitrarily shown for convenience of explanation, and therefore, the inventive concepts disclosed in this specification are not necessarily limited to those shown in the drawings.

The rubber composition for a tire according to one embodiment includes a raw rubber comprising at least one selected from natural rubber and synthetic rubber; An inorganic filler comprising silica; And a softener comprising a triterpenoid compound containing a plurality of fused aliphatic rings, wherein the triterpenoid compound containing a plurality of the fused aliphatic rings is selected from the group consisting of And a dammar compound obtained from a dammar resin or gum.

A triterpenoid compound containing a plurality of aliphatic rings fused with a rubber composition for a tire comprises a darmeric compound and the darmar compound includes a plurality of rings so that the braking on the wet surface Performance can be improved and other properties can be improved. Therefore, the rubber composition for a tire can improve physical properties such as braking performance on a wet road surface without environmental problems.

The molecular weight of the dammar compound including the triterpenoid compound containing a plurality of the fused aliphatic rings may be 1000 to 2000. For example, the molecular weight of a damar compound including a triterpenoid compound containing a plurality of fused aliphatic rings may be 1000 to 1500. For example, the molecular weight of a dammar compound including a triterpenoid compound containing a plurality of fused aliphatic rings may be 1200 to 1500. It is possible to provide more improved physical properties in the molecular weight range.

For example, a damar compound including a triterpenoid compound containing a plurality of fused aliphatic rings may be a compound represented by the following general formulas (1) to (6), but is not limited thereto, In the technical field, any compound containing a plurality of aliphatic rings as a dammar compound is all possible:

&Lt; Formula 1 > < EMI ID =

&Lt; Formula 3 > < Formula 4 >

&Lt; Formula 5 > < EMI ID =

In the above formulas, R &lt; 1 &gt; is hydrogen, a hydroxy group, or a carbonyl group.

And a triterpenoid compound containing a plurality of aliphatic rings fused with a softener in a rubber composition for a tire, and a triglyceride.

For example, 1 to 20% by weight of a damar compound and 80 to 99% by weight of a triglyceride, which is contained in a triterpenoid compound containing a plurality of aliphatic rings fused with a softening agent can do. For example, if the content of the dammar compound contained in the triterpenoid compound containing a plurality of fused aliphatic rings is less than 1% by weight, the effect may be insignificant. For example, when the amount of the dammar compound contained in the triterpenoid compound containing a plurality of fused aliphatic rings exceeds 20% by weight, the softener is solidified by precipitation or the like, It may be difficult to function as a softening agent acting as a solvent. For example, the softening agent may comprise 3 to 20% by weight of the tamaran-based compound and 80 to 97% by weight of triglycellite. For example, the softening agent may comprise 5 to 20% by weight of the tamarin compound and 80 to 95% by weight of triglycellite. For example, the softening agent may comprise 7 to 20% by weight of the tamarin compound and 80 to 93% by weight of triglycellite.

The triglyceride additionally included as a softener in the rubber composition for a tire may be represented by the following general formula (7)

&Lt; Formula 7 >

Wherein R1, R2, and R3 are each independently an alkyl group having 10 to 20 carbon atoms, and at least one alkyl group among R1, R2, and R3 includes at least one double bond. The R1, R2, and R3 may be derived from a fatty acid. For example, when R1, R2 and R3 are selected from the group consisting of luaric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, acid, lactic acid, lignoceric acid, cerotic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, May be derived from one or more fatty acids selected from the group consisting of elaidic acid, vaccenic acid, linoleic acid, and arachidonic acid.

The rubber composition for a tire includes silica as an inorganic filler.

Since the rubber composition for a tire contains silica as an inorganic filler, the mechanical strength of the rubber composition for a tire can be well maintained.

The BET specific surface area of silica may be at least 110 m ² / g. For example, the BET specific surface area of silica may be at least 130 m ² / g. For example, the BET specific surface area of silica may be at least 150 m ² / g. Further, the BET specific surface area of the silica may be 290 m ² / g or less. In this case, the workability can be improved. For example, the BET specific surface area of silica may be 190 m ² / g or less. For example, the BET specific surface area of silica may be less than 180 m ² / g. For example, the BET specific surface area of silica may be, for example, 110 to 190 m ² / g.

The silica may be prepared by a wet process or may be prepared by a dry process. As a preferable commercial product of silica, for example, ULTRASIL 7000GR manufactured by EVONIK Co., Ltd. and the like can be mentioned.

Examples of the filler that can be blended in addition to silica as the inorganic filler include calcium carbonate, aluminum hydroxide, clay, mica, magnesium oxide and the like. Particularly, the filler other than silica (hereinafter, simply referred to as another filler) among the inorganic fillers may be at least one selected from the group consisting of calcium carbonate, aluminum hydroxide, clay, mica, and magnesium oxide.

Further, the rubber composition for a tire may further include carbon black. The blending amount of carbon black may be 2 to 5 parts by weight based on 100 parts by weight of the rubber component, but is not necessarily limited to this range and can be adjusted within the range of providing a rubber composition for a tire having improved physical properties. For example, if the content of carbon black is too low relative to 100 parts by weight of the raw material rubber, crack resistance and workability may be deteriorated. For example, if the content of carbon black is too high relative to 100 parts by weight of the starting rubber, it may be difficult to impart low heat build-up.

The iodine adsorption specific surface area of the carbon black may be 30 g / kg or more. The mechanical strength of the rubber composition for a tire in the above range can be improved. For example, the iodine adsorption specific surface area of carbon black may be at least 40 g / kg. For example, the iodine adsorption specific surface area of the carbon black may be 70 g / kg or more. For example, the iodine adsorption specific surface area of the carbon black may be 150 g / kg or less. The workability of the rubber composition for a tire in the above range can be improved. For example, the iodine adsorption specific surface area of the carbon black may be even 130 g / kg or less. For example, the iodine adsorption specific surface area of carbon black may be less than 125 g / kg.

As a preferable commercially available product of carbon black, for example, [N-330] of Ebonic Co., Ltd. and the like can be mentioned.

For example, 10 to 100 parts by weight of an inorganic filler and 1 to 40 parts by weight of a softener may be contained in 100 parts by weight of the raw material rubber in the rubber composition for a tire.

For example, the rubber composition for a tire may contain 30 to 100 parts by weight of an inorganic filler based on 100 parts by weight of the raw material rubber. For example, the rubber composition for a tire may contain 50 to 100 parts by weight of an inorganic filler per 100 parts by weight of the raw rubber. For example, the rubber composition for a tire may contain 70 to 100 parts by weight of an inorganic filler per 100 parts by weight of the raw rubber. A rubber composition for a tire which provides further improved physical properties to the above composition range can be obtained.

For example, the rubber composition for a tire may contain 1 to 40 parts by weight of a softening agent based on 100 parts by weight of the raw rubber. For example, the rubber composition for a tire may contain 10 to 40 parts by weight of a softening agent based on 100 parts by weight of the raw rubber. For example, 20 to 40 parts by weight of a softening agent may be contained in 100 parts by weight of the raw rubber in the tire rubber composition. A rubber composition for a tire which provides further improved physical properties to the above composition range can be obtained.

In the rubber composition for a tire, the starting rubber is not particularly limited, and synthetic rubber, natural rubber or a mixture thereof may be used.

Natural rubber is natural rubber (NR) conventionally used in the rubber industry; And other diene rubbers such as isoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber and the like; Epoxy clipped natural rubbers (ENR); Thermoplastic natural rubbers (TPNR); Liquid natural rubbers and the like can be used.

The synthetic rubber is not limited as long as it is an amorphous and thermoplastic polymer material commonly used in the art. For example, chloroprene rubber (CR), acrylonitrile-butadiene rubber (nitrile rubber), NBR ), Hydrogenated nitrile rubber (HNBR), ethylene-acrylic rubber (AEM), chlorosulphonated polyethylene rubber (CSM), fluorocarbon rubber, FPM), vinyl-methyl silicone rubber (VMQ), epichlorohydrin rubber (ECO), polyester urethane (AU), polyether urethane EU) and thermoplastic polyether-ester (YBPO), isoprene rubber (IR), styrene-butadiene rubber (SB) Non-polar hydrocarbon rubbers such as ethylene-propylene-diene rubber (EPDM) and ethylene-propylene rubber (EPM), bromobutyl rubber (BIIR) Butadiene rubber (BR), isobutene-isoprene rubber (butyl rubber), IIR) such as chlorobutyl rubber (CIIR), polyacrylate rubber (ACM ), Perfluorocarbon rubber (FFKM), fluorosilicone rubber (FMQ), and the like can be used.

For example, the raw rubber may include solution styrene butadiene rubber (SSBR). By using solution-polymerized styrene-butadiene rubber as raw material rubber, it is possible to provide improved physical properties in the production of a tire component, for example, a tire tread in which a high molecular weight cured rubber is required.

The raw rubber may be a mixture of two or more rubbers, and two or more rubbers may be mixed in a weight ratio of 9: 1 to 1: 9.

The vulcanizing agent is not limited to any kind as long as it is used in the art as a rubber crosslinking agent such as an inorganic vulcanizing agent and an organic vulcanizing agent.

Examples of the inorganic vulcanizing agent include inorganic vulcanizing agents such as powdered sulfur, colloidal sulfur, precipitated sulfur, and insoluble sulfur. The organic vulcanizing agent includes 4,4'-dithiodimorpholine, N, N'-dithio-bis- (hexahydro-2H-azepinone-2), tetramethyl-thiuram disulfide, TMTD), tetraethyl-thiuram disulfide (TETD), tetrabutyl-thiuram disulfide (TBTD), P-Quinone-dioxine, dibenzoyl-para- (Dibenzoyl-P-quinonedioxine), tetrachloro-p-benzoquinone, and the like, but the present invention is not limited thereto.

The raw material rubber may be vulcanized by including a vulcanizing agent and optionally a vulcanization accelerator.

The vulcanizing agent may be used in an amount of 0.5 to 2.0 parts by weight based on 100 parts by weight of the raw material rubber. When the vulcanizing agent is less than 0.5 parts by weight, it may become unvulcanized, and when the vulcanization agent is more than 2.0 parts by weight, it may be vulcanized.

The vulcanization accelerator accelerates the vulcanizing power of the vulcanizing agent to shorten the vulcanization time, lower the vulcanization temperature, reduce the amount of vulcanizing agent used, and improve the quality. The vulcanization accelerator may be selected from mercaptobenzothiazole, dibenzolthiazyl disulfide, N-cyclohexyl-benzothiazyl-2-sulfenamide (CBS), N-oxydi N-oxydiethylene-benxothiazyl sulfenamide, N-tert-butyl-2-benxothiazyl sulfenamide, N, N-diphenylguanidine N- , N-diphenyl guanidine (DPG), Zinc salt of Mercaptobenzothiazole, Dibenzothiazyl disulfide, Sodium dimethyldithiocarbamate, Tetramethyl-thiuram disulfide thiuram disulfide, teramethyl-thiuram monosulfide, zinc dimethyldithiocarbamate, sodium diethyldithiocarbamate, tetraethyl-thiuram disulfide, Thiuram disulfide, Zinc diethyldithiocarbamate, Sodium dibutyl dithio carbamate, Tetrabutyl-thiuram disulfide, di-n-dodecyldithiocarbamate, Di-n-butyl-dithiocarbamate, and the like can be used. However, it is not limited thereto, and any of them can be used as the vulcanization accelerator in the related art. The vulcanization accelerator may be used by mixing two or more vulcanization accelerators.

The vulcanization accelerator may be used in an amount of 1.0 to 3.0 parts by weight based on 100 parts by weight of the raw rubber. When the vulcanization accelerator is less than 1.0 part by weight, it may become unhull sulfur. When the vulcanization accelerator is more than 3.0 parts by weight, it may be vulcanized.

The vulcanization accelerator aid may be used in combination with the vulcanization accelerator to activate the vulcanization accelerator and to further complete the accelerating reaction. For example, as a vulcanization accelerating assistant, zinc oxide (ZnO), active zinc oxide, surface-treated zinc oxide, zinc oxide paste, complex zinc oxide, zinc carbonate (ZnCO ₃ ), magnesium oxide (MgO), litharge monoxide, red read, potassium hydroxide (KOH), and the like; An organic vulcanization accelerator such as stearic acid, oleic acid, lauric acid, zinc stearate, dibutyl ammonium oleate and the like can be used.

The vulcanization accelerating assistant may be used in an amount of 3.0 to 6.0 parts by weight based on 100 parts by weight of the raw rubber. When zinc oxide and stearic acid are used together, 2.0 to 3.5 parts by weight and 1.0 to 2.5 parts by weight may be used, respectively. In this case, zinc oxide and stearic acid work together to form an effective complex with the vulcanization accelerator, and the crosslinking action can be promoted.

Further, the rubber composition for a tire may further include any one or two or more additives selected from a tackifier, a modifier, an anti-scorch agent, a neutralizer and a light stabilizer within a range that does not impair the physical properties of the composition.

The tackifier is a drug for increasing the tackiness of the surface, and is compatible with the rubber component and can be kept sticky for a long time, so long as it can be used in the art. For example, coumarone-indene resins, terpene-phenolic resins, polybutenes, hydrogenated ester of resins and the like can be used.

The tackifier may be contained in an amount of 3 to 5 parts by weight based on 100 parts by weight of the raw material rubber. The physical properties of the rubber composition including the tensile strength may not be affected in the above content range.

The modifier may be used to improve the physical properties and processability of the vulcanizate. Examples thereof include P, P'-diaminodiphenylmethane (DAPM), N- (2-methyl- (2-methyl-2-nitropropyl) -4-nitrosoaniline, liquid polybutadiene, polyisobutyrene and the like can be used.

The modifier may be added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the rubber component. The caking property can be improved without impairing the impact resistance of the rubber composition produced in the above content range.

The scotch inhibitor serves to prevent the vulcanization reaction of the raw rubber from occurring in the rubber manufacturing working stage before the vulcanization process, and any scoop inhibitor can be used as long as it can be used in the technical field. Examples of the organic acid include organic acids such as anhydrous tallow acid, salicylic acid, acetylsalicylic acid and benzoic acid, N-nitrosodiphenylamine, N-nitrosophenyl-B-naphthalamine ) Can be used.

The scorch inhibitor may be included in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the rubber component.

The anti-corrosive agent is a material which imparts plasticity to the raw material rubber to have uniform dispersion and viscosity. For example, a mixture of 2,3,4,5,6-pentachlorobenzenethiolate and zinc filler of 2,3,4,5,6-pentachlorobenzene thiolate, such as Renacit-iV, Struktol A86, 40MS, and the like may be used but are not limited thereto, and any of them can be used as a bad agent in the art.

The miscibility agent may be used in an amount of 0.1 to 0.3 parts by weight based on 100 parts by weight of the raw rubber. If the content of the anti-corrosive agent is less than 0.1 part by weight, the rubber component may not be dispersed properly, and if the content of the anti-corrosive agent is more than 0.3 part by weight, the rubber component may chemically cut off the rubber compound.

The rubber composition for a tire can be produced by a conventional method used in the art. As the rubber composition manufacturing apparatus for a tire, for example, a mixing and crosslinking process can be performed using a roll mill, a Banbury mixer, an internal mixer, a continuous mixer, a kneader or a mixed extruder, but the present invention is not limited thereto.

In the mixing process, the rubber raw material, the additives and the filler are mixed before vulcanizing agent, vulcanization accelerator and the like. At this time, the temperature is preferably 100 to 170 DEG C, and the rubber composition is prepared by mixing for 10 to 20 minutes. Subsequently, a vulcanizing agent, a vulcanization accelerator and the like are mixed in the rubber composition. In the crosslinking step, the temperature is lowered to 40 to 80 캜 and mixed for 5 to 15 minutes, followed by extrusion to prepare an unvulcanized rubber composition. Then, the temperature in the vulcanization step is preferably 100 to 170 DEG C, and the vulcanized rubber composition is vulcanized for 10 to 20 minutes.

The tensile strength of the rubber composition for a tire containing a dammar compound may be 230 kgf / cm ^{2 or} more. For example, the tensile strength of a rubber composition for a tire containing a dammar compound may be 235 kgf / cm ^{2 or} more. For example, the tensile strength of a rubber composition for a tire containing a dammar compound may be 240 kgf / cm ^{2 or} more. The rubber composition for a tire comprising a dammar compound has a tensile strength of 230 kgf / cm ² or more, whereby the extrusion characteristics of the tire including the rubber composition for a tire can be improved.

The elongation percentage of the rubber composition for a tire containing a dammar compound may be 480% or more. The elongation percentage of the rubber composition for a tire containing a dammar compound may be 490% or more. The elongation percentage of the rubber composition for a tire containing a dammar compound may be 500% or more. The elongation percentage of the rubber composition for a tire containing a dammar compound may be 510% or more. When the rubber composition for a tire containing a dammar compound has an elongation percentage of 480% or more, the flexibility of the tire including the rubber composition for a tire is improved and cracks can be prevented.

According to another embodiment, the tire comprises a tread rubber comprised of the rubber composition described above.

Referring to FIG. 1, a tire 10 includes a tread portion 100, a sidewall portion 200, and a bead portion 300.

 The tread portion 100 is a portion in contact with the ground in a sectional view, and serves to protect the tire from impacts and trauma from road surfaces and the like. A plurality of blocks partitioned by grooves may be formed on the surface of the tread portion in order to drain the tire.

The sidewall 200 and the bead 300 are sequentially positioned on both sides of the tread portion along the width direction of the tire.

The sidewall 200 is a portion extending from both ends of the tread to form a side surface of the tire. The sidewall 200 is capable of withstanding the repeated shrinkage and expansion action during traveling and protecting the carcass layer 400 located on the inner side .

The bead portion 300 is provided at both ends of the sidewall 200 to surround the end portion of the cord paper. The bead portion 300 includes a bead core 500 including a ring-shaped steel wire rod.

A carcass layer 400 is positioned between the pair of right and left bead parts 300 and is joined to a tire rubber sheet inside the tire to form a skeleton of the tire. The carcass layer 400 is bonded to the bead core 500 ) From the inside of the tire to the outside.

The inner liner 700 is disposed on one side of the carcass layer 400 so as to prevent the air inside the tire from escaping to the outside.

The belt layer 600 may be positioned on the outer surface of the carcass layer 400 located in the tread portion 100 as a reinforcing layer that enhances the elasticity of the tread and provides steering and stability.

In the tire, the tread rubber of the tread portion 100 is made of the above-mentioned rubber composition for a tire. That is, the tread portion 100 is formed by using the above-described rubber composition for a tire.

Fig. 1 exemplifies the tire for a passenger car, but the present invention is not limited to this, and a tire used for various vehicles such as passenger cars, trucks, buses, heavy vehicles, etc. is provided.

The tire can be manufactured by a conventionally known method. That is, for example, when the above-described rubber composition for a tire is used, the rubber composition for a tire having the above composition is mixed and extruded in accordance with the shape of the tread portion of the tire in the unvulcanized state, To form an unvulcanized tire. By heating and pressing the unvulcanized tire in a vulcanizer, the tire described above can be obtained.

These tires have reduced use of raw materials derived from petroleum resources, have been sufficiently considered for resource conservation and environmental protection, and exhibit excellent performance. Specifically, when the rubber composition for a tire, which is highly compatible with the braking performance on a wet road surface, the tensile characteristic, and the processability at the time of preparation, is used, it is possible to obtain a tire excellent in durability and fuel economy. Therefore, it can be suitably applied to various applications such as an eco-tires friendly to the global environment, such as passenger cars, trucks, buses, heavy vehicles, and the like.

The present invention will be described in more detail by way of the following examples and comparative examples. However, the examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

Examples 1 to 2 and Comparative Examples 1 to 2

(Preparation of unvulcanized rubber sheet)

Among the compounding ingredients shown in Table 1, the ingredients except for the sulfur and the vulcanization accelerator were metered into a Banbury mixer having a capacity of 1.6 L so as to have a fill factor of 0.70, and the mixture was mixed for 5 minutes. An unvulcanized rubber composition was prepared by adding sulfur and a vulcanization accelerator in the amounts shown in Table 1 and mixing for 1 minute and extruded to a predetermined thickness to prepare an unvulcanized rubber sheet having a predetermined shape. A mixture of natural oil and dammar was used as a softener.

(Preparation of test rubber sheet)

The unvulcanized rubber sheet of the predetermined shape prepared above was vulcanized at 160 DEG C for 30 minutes in a vulcanizer to prepare a test rubber sheet.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 combination
(Parts by weight) Synthetic rubber ¹⁾ 100 100 100 100 Silica ²⁾ 80 80 80 80 Silane coupling agent ₃₎ 12.8 12.8 12.8 12.8 ZnO ₂ 3 3 3 3 Stearic acid 2 2 2 2 Petroleum oil ⁴⁾ 37.5 (100) - - - Natural oil ⁵⁾ - 27 (100) 24.3 (90) 21.6 (80) Tamar ⁶⁾ - - 2.7 (10) 5.4 (20) sulfur 1.5 1.5 1.5 1.5 Vulcanization accelerator ⁷⁾ 1.5 1.5 1.5 1.5 Vulcanization accelerator ⁸⁾ One One One One

1) Synthetic rubber: Solution Styrene Butadiene Rubber (SSBR, JSR) having a vinyl content of 55 to 65% and a styrene content of 20 to 30%

2) Silica: ULTRASIL-7000GR (EVONIK)

3) Silane coupling agent: X-50S (EVONIK)

4) Petroleum oil: RAE (Residual Aromatic Extracts, SHELL)

5) Natural oil: oleic triglyceride (UNS CHEM, Korea, Ulsan)

6) Tamar: Gum Dammar (KTRADE)

7) Vulcanization accelerator: CBS (N-cylcohexylbenzo thiazole, SHANDONG SUNSINE)

8) Vulcanization accelerator: DPG (N, N-diphenyl guanidine, SHANDONG SUNSINE)

Although not shown in Table 1 above, when the mixing ratio of natural oil and dammar in the rubber composition is more than 8: 2 and the content of dammar is more than 20% by weight, the softener, which is a mixture of natural oil and dammar, solidification) and could not function as a softening agent.

Evaluation example

The properties of the rubbers prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated as described below, and the results are shown in Table 2 below.

Measurement of Mooney viscosity

It was measured by ASTM standard D 1646. The Mooney viscosity indicates the viscosity of the unvulcanized rubber. The lower the value, the better the workability of the unvulcanized rubber.

Measurement of hardness (rubber hardness)

And measured by a Shore A type hardness tester. The hardness indicates the stability of the specimen to the rigidity of the specimen. The higher the value, the better the stability of the manipulation.

300% modulus measurement (300% modulus)

Tensile stress at 300% elongation at 300% elongation was measured according to ASTM Specification D 412, and the higher the value, the better the strength.

Tensile strength

The force per unit area was measured as the maximum stress value until the test piece was broken in the tensile tester.

Measurement of strain at break

The strain was measured by a method in which the strain value at break of the test piece in the tensile tester was expressed as a percentage.

Stress at break

The force per unit area was measured as the value of the stress when the test piece was broken in the tensile tester.

Rebound resilience

The elastic modulus represents the elasticity of the rubber specimen, and the higher the elasticity, the greater the elasticity.

Fatigue characteristic

A method of measuring the crack growth rate according to the elongation rate after generating a 2 mm crack (hole) at 300 rpm and 5 Hz with a dynamic fatigue tester, and measuring the crack growth rate according to the test corresponding to 2000, 6000, and 10000 cycles And the crack length is measured. The shorter the crack length, the better the fatigue performance.

Viscoelasticity

Using a Gabo viscometer, the value of Tan δ was measured from -60 ° C to 80 ° C under a frequency of 10 Hz with a 0.2% strain. At this time, the temperature with the highest tan δ is defined as the glass transition temperature, and the larger the value of 0 ° C tan δ, the better the braking performance on the wet road surface. The lower the tan δ value of 60 ° C, .

Extrusion property

The extrusion performance was evaluated according to the method B of ASTM D2230, the edges of the extrudate were scored from 1 to 10, and the scoring of the surface states A to E was scored. The edge was the weakest at 1 and the best at 10. The surface state was the best in A and the lowest in C.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 evaluation Pattern viscosity 110 105 107 110 Hardness 69 71 69 71 300% modulus
[kgf / cm ² ] 130 127 121 132 The tensile strength
[kgf / cm ² ] 203 226 242 246 Elongation [%] 380 460 520 490 Breaking strength
[kgf / cm ² ] 55 58 54 58 Rebound resilience [%] 21.0 46.6 40.6 34.6 Fatigue characteristics [mm] 5.27 3.19 3.47 3.30 Tg [캜] -7.2 -19.0 -17.3 -16.0 0 ℃ Tanδ 0.860 0.373 0.417 0.431 60 캜 Tanδ 0.112 0.093 0.101 0.107 Extrusion characteristics (edge) 3 4 5 5 Extrusion characteristics (surface state) C A A A

The results of Table 2 show that the rubber compositions of Examples 1 and 2 to which a vegetable oil containing a dammar is applied have lower Tg than the rubber composition of Comparative Example 1 including a petroleum oil, The elasticity was also improved.

Compared with the rubber composition of Comparative Example 2 containing only triglyceride, the rubber compositions of Examples 1 and 2 had a somewhat higher pattern viscosity but improved workability by improvement of extrusion characteristics.

Compared with the rubber composition of Comparative Example 2 containing only triglyceride, the rubber composition of Examples 1 and 2 had an increase in tan? Value of 0 占 폚 and improved braking performance on a wet road surface.

Compared with the rubber composition of Comparative Example 2 containing only triglyceride, the rubber compositions of Examples 1 and 2 have increased tensile strength, elongation percentage, fracture strength and the like and improved tensile properties.

Therefore, the rubber compositions of Examples 1 and 2 have improved extrusion characteristics, tensile properties, and braking performance on a wet road surface as compared with the rubber composition of Comparative Example 2 using only vegetable oil.

10: Tire 100: Tread
200: side wall portion 300: bead portion
400: carcass layer 500: bead core
600: belt layer 700: inner liner

Claims (8)

A raw rubber comprising at least one selected from natural rubber and synthetic rubber; An inorganic filler comprising silica; And a softener comprising a triterpenoid compound containing a plurality of fused aliphatic rings,
1 to 20% by weight of a triterpenoid compound containing a plurality of aliphatic rings fused with the softening agent and 80 to 99% by weight of triglyceride,
Wherein the triterpenoid compound containing a plurality of the fused aliphatic rings is a dammar compound represented by the following formulas (1) to (6):
&Lt; Formula 1 >< EMI ID =

&Lt; Formula 3 &gt;&lt; Formula 4 &gt;

&Lt; Formula 5 &gt;&lt; EMI ID =

In the above formulas, R < 1 > is hydrogen, a hydroxy group, or a carbonyl group. delete delete delete The rubber composition for a tire according to claim 1, wherein the triglyceride is represented by the following formula (7)
&Lt; Formula 7 >

In this formula,
R 1, R 2, and R 3 are each independently an alkyl group having 10 to 20 carbon atoms,
At least one alkyl group of R 1, R 2, and R 3 contains at least one double bond. The rubber composition for a tire according to claim 1, which comprises 10 to 100 parts by weight of an inorganic filler and 1 to 40 parts by weight of a softening agent based on 100 parts by weight of the raw rubber. The rubber composition for a tire according to claim 1, comprising a solution-styrene butadiene rubber (SSBR) solution-polymerized with the raw rubber. A tire comprising a tread rubber consisting of the rubber composition according to any one of claims 1 to 7.

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