KR102515983B1 - Rubber composition for tire tread with improved wear performance and tire manufactured using the same - Google Patents

Abstract

A rubber composition for tire tread according to an embodiment of the present invention includes a novel styrene-butadiene rubber including a styrene content of 33% to 40% by weight and a vinyl content of 20% to 30% by weight; and 100 parts by weight of raw rubber including butyl rubber polymerized under an alkyllithium catalyst, having a cis content of 30 wt% to 50 wt%, and a vinyl content of 5 wt% to 15 wt%.
A tire according to an embodiment of the present invention is manufactured from the rubber composition for tire tread of the present invention.

Description

Rubber composition for tire tread with improved wear performance and tire manufactured therefrom {Rubber composition for tire tread with improved wear performance and tire manufactured using the same}

The present invention relates to a rubber composition for tire tread with improved abrasion performance comprising a novel synthetic rubber and a tire manufactured therefrom.

Today, exhaust gas regulations are getting stricter, and improving fuel efficiency by reducing the rolling resistance of tires mounted on automobiles is a very important technical task.

Since the tread portion of the tire occupies the most weight, it has the greatest influence on wear performance and fuel efficiency.

Conventionally, to improve wear performance, methods such as reducing filler content or applying butadiene rubber (BR) have been used, but wet road performance and fuel economy performance have to be sacrificed to improve wear performance. there is.

An object of the present invention is to provide a rubber composition for a tire tread capable of significantly improving wear characteristics and reducing a tread height without sacrificing wet road performance and fuel economy, and a tire manufactured therefrom.

A rubber composition for tire tread according to an embodiment of the present invention includes a novel styrene-butadiene rubber including a styrene content of 33% to 40% by weight and a vinyl content of 20% to 30% by weight; and 100 parts by weight of raw rubber including butyl rubber polymerized under an alkyllithium catalyst, having a cis content of 30 wt% to 50 wt%, and a vinyl content of 5 wt% to 15 wt%.

A tire according to an embodiment of the present invention is manufactured from the rubber composition for tire tread of the present invention.

A tire using the tire rubber composition according to various embodiments of the present invention has remarkably improved wear characteristics without sacrificing wet road performance and fuel efficiency.

In addition, since the tire of the present invention can have a low tread depth, weight can be saved, and dust generated during tire wear can also be reduced, so it is environmentally friendly.

1 is a view schematically showing a novel styrene-butadiene rubber according to an embodiment of the present invention.
2 is a diagram schematically showing the structure of a tire according to an embodiment of the present invention.

In the present invention, a tire rubber composition that can be actually applied and used in tires through confirmation of the basic performance level using a novel synthetic rubber and has significantly improved wear characteristics without sacrificing wet road performance and fuel economy performance was prepared.

The inventive idea disclosed in this specification can be subjected to various transformations and can have various embodiments, and specific embodiments are described in detail in the detailed description and, if necessary, specific embodiments are illustrated in the drawings. Effects and characteristics of the inventive idea of the present specification, and methods for achieving them will become clear with reference to the embodiments described later in detail together with the drawings. However, the inventive idea of the present specification is not limited to the embodiments disclosed below and may be implemented in various forms.

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from another component without limiting meaning.

In the following examples, expressions in the singular number include plural expressions unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have mean that features or components described in the specification exist, and do not preclude the possibility that one or more other features or components may be added.

In case an embodiment is otherwise implementable, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order reverse to the order described.

Hereinafter, if necessary, embodiments of the present invention will be described in detail with reference to the accompanying drawings. do it with

In the drawings, the size of components may be exaggerated or reduced for convenience of description. For example, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, the inventive ideas disclosed herein are not necessarily limited to those shown.

Rubber composition for tire tread

A rubber composition for tire tread according to an embodiment of the present invention includes 100 parts by weight of raw rubber, and the raw rubber includes novel styrene-butadiene rubber (S-SBR) and butyl rubber.

Raw material rubber serves as a base of a rubber composition for tire treads, and serves to impart basic performance, such as braking force and steering stability, to the tire.

The novel styrene-butadiene rubber is characterized by comprising a styrene content of 33% to 40% by weight and a vinyl content of 20% to 30% by weight. That is, the novel styrene-butadiene rubber is characterized by being designed with a high content of styrene. When the styrene content and the vinyl content are within the above ranges, braking performance may be improved. Preferably, the new styrene-butadiene rubber may include a styrene content of 36% by weight and a vinyl content of 26% by weight. In addition, the new styrene-butadiene rubber includes treated distillate aromatic extracted (TDAE) oil. In this case, 10 phr to 30 phr of TDAE oil may be included. Preferably, 20 phr of TDAE oil may be included relative to the total amount of the new styrene-butadiene rubber.

The novel styrene-butadiene rubber may have a weight average molecular weight of 650,000 g/mol to 750,000 g/mol, a molecular weight distribution of 1.0 to 2.0, and a glass transition temperature of -40 to -20 °C. Preferably, the novel styrene-butadiene rubber may have a weight average molecular weight of 710,000 g/mol, a molecular weight distribution of 1.6, and a glass transition temperature of -35 °C.

The novel styrene-butadiene rubber may be a rubber modified at both ends.

Specifically, referring to FIG. 1 , the newly synthesized styrene-butadiene rubber may be a rubber to which both ends are modified. The novel styrene-butadiene rubber may have a 2 arms constructure or a 3 arms constructure.

Specifically, since modifiers can be applied only to the end of a molecular chain, conventional techniques have been able to impart modifiers to only one end or both ends of a chain. To overcome this limitation, the first molecular chain was created using an initiator, and the end was activated with an anion. Modification of both ends may be applied by imparting a functional agent to the anion-activated terminal and polymerizing two or three polymer chains.

At this time, both terminals may be modified with at least one functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amine group, an alkoxyl group, a silanol group, a sulfonyl group, tin (Sn), and silicon.

Both ends of the novel styrene butadiene rubber may be modified with the same or different functional groups. For example, both ends of the new styrene butadiene rubber may be modified with the same carboxy group. For example, one end of the new styrene butadiene rubber may be modified with a carboxyl group and the other end with a hydroxyl group.

The novel styrene-butadiene rubber of the present invention can be produced by a batch like continuous method.

However, the examples are not limited thereto, and the novel styrene-butadiene rubber may be produced by a continuous method or a batch method.

According to one embodiment, the new styrene-butadiene rubber may be continuously polymerized. Compared to the novel styrene-butadiene rubber prepared by the batch method, the novel styrene-butadiene rubber produced by the continuous method has a somewhat disadvantageous processability due to its long molecular chain, but is advantageous in wear resistance due to its high molecular weight.

The novel styrene-butadiene rubber may be included in an amount of 60 parts by weight to 80 parts by weight based on 100 parts by weight of raw rubber. When the content of the new styrene-butadiene rubber is less than 60 parts by weight or greater than 80 parts by weight, abrasion resistance and fuel efficiency may be deteriorated.

Meanwhile, butyl rubber included in the raw rubber may be polymerized under an alkyllithium catalyst, have a cis content of 30 wt% to 50 wt%, and a vinyl content of 5 wt% to 15 wt%. When the butyl rubber has a cis content and a vinyl content within the above ranges, hysteresis of the rubber may be reduced to improve low fuel consumption performance. Preferably, the butyl rubber has a cis content of 40.5% and may have a vinyl content of 11.4%.

Butyl rubber may be included in an amount of 20 parts by weight to 40 parts by weight based on 100 parts by weight of raw rubber. Preferably, it may be included in 30 parts by weight based on 100 parts by weight of raw rubber.

In this case, the butyl rubber may be terminal-modified rubber. In the present invention, the dispersibility of chain-end functionalized silica can be improved by applying a functional group to butyl rubber. Through this, the affinity for silica may be improved, and low fuel consumption performance may be obtained.

The rubber composition for tire tread according to various embodiments of the present invention may include carbon black as a filler. Carbon black may be included in an amount of 3 to 7 parts by weight based on 100 parts by weight of raw rubber.

Carbon black can prevent wear performance deterioration due to the use of silica, and can improve the appearance characteristics of tire treads, such as increasing the degree of coloring by developing black. In addition, the scorch phenomenon and weakening of the bond between the silica and the silane coupling agent can be prevented because the mixing temperature is increased compared to when silica alone is used.

The rubber composition for tire tread according to an embodiment of the present invention may further include a filler to improve tire reinforcing properties. The filler may be silica.

Silica may have a nitrogen adsorption specific surface area of 160 to 180 m 2 /g and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 150 to 170 m 2 /g. Since silica used in the rubber composition for tire tread of the present invention has a large specific surface area, it is possible to improve abrasion resistance and braking performance of a tire.

Silica may be included in 75 to 85 parts by weight based on 100 parts by weight of raw rubber. When the content of silica is in the above range, braking and wear resistance may be improved, and when the content of silica is less than 75 parts by weight or greater than 85 parts by weight, fairness may be significantly deteriorated. In the present invention, the fuel efficiency can be supplemented by reducing the silica content.

Silica may be surface treated with a coupling agent, and a silane coupling agent may be used as the coupling agent. A tetrasulfide-based compound may be used as the silane coupling agent. The tetrasulfide-based compound may have a sulfur content of 21% to 25% by weight and a molecular weight of 500 g/mol to 550 g/mol. The coupling agent may be surface treated by using 6 to 10 parts by weight based on 100 parts by weight of raw rubber.

The rubber composition for tire tread according to various embodiments of the present invention may further include an additive. The additive may include at least one selected from an anti-aging agent, a vulcanizing agent, a vulcanization accelerator, and a vulcanization accelerator.

Anti-aging agents can maintain the elasticity, durability and lifespan of tires. The anti-aging agent may include at least one selected from the group consisting of Parrafine wax, N-(1,3-dimethylbutyl)-N-phenylenediamine, and 2,2,4-trimethyl-1,2-dihydroquinoline. can In the present invention, wax may be included as an antiaging agent, and 1 to 3 parts by weight of wax may be included based on 100 parts by weight of raw rubber.

The vulcanizing agent may include a sulfur-based vulcanizing agent, an organic peroxide, a resin vulcanizing agent, and a metal oxide such as magnesium oxide.

Sulfur-based vulcanizing agents include inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), and colloidal sulfur, tetramethylthiuram disulfide (TMTD), tetraethyl tea It may contain organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine, and other elemental sulfur or vulcanizing agents that produce sulfur, such as amine disulfide and polymeric sulfur etc. may be included.

In addition, organic peroxides include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3 -bis(t-butylperoxypropyl)benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxybenzene, 2,4-dichlorobenzoyl peroxide, 1,1-dibutylperoxy- 3,3,5-trimethylsiloxane, n-butyl-4,4-di-t-butylperoxyvalerate, and the like may be included.

The amount of the vulcanizing agent may be 0.5 to 2 parts by weight based on 100 parts by weight of the raw rubber. When the content of the vulcanizing agent is within the above range, the raw rubber may be less sensitive to heat and chemically stable due to an appropriate vulcanization effect.

The vulcanization accelerator means an accelerator that accelerates the vulcanization rate or promotes a delay action in the initial vulcanization step. Vulcanization accelerators are sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, xanthate-based, and mixtures thereof. can be chosen

Sulfenamide-based vulcanization accelerators are N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), N,N-dicyclohexyl-2-benzo thiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, and mixtures thereof.

Thiazole-based vulcanization accelerators include, for example, 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole, 2 -Copper salt of mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-diethyl 4 -morpholinothio)benzothiazole and mixtures thereof.

Thiuram-based vulcanization accelerators include, for example, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuramdisulfide, dipentamethylenethiurammonosulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, tetrabutylthiuramdisulfide, pentamethylenethiuramtetrasulfide, and mixtures thereof.

The thiourea-based vulcanization accelerator may be selected from, for example, thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diortotolylthiourea, and mixtures thereof.

The guanidine-based vulcanization accelerator may be selected from N,N-diphenylguanidine (DPG), diortolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate, and mixtures thereof.

Dithiocarbamic acid-based vulcanization accelerators include ethylphenyldithiocarbamate zinc, butylphenyldithiocarbamate zinc, dimethyldithiocarbamate sodium, dimethyldithiocarbamate zinc, diethyldithiocarbamate zinc, dibutyldithio Zinc Carbamate, Diamyldithiocarbamate Zinc, Dipropyldithiocarbamate Zinc, Pentamethylene Dithiocarbamate Zinc and Piperidine Complex Salt, Hexadecylisopropyldithiocarbamate Zinc, Octadecylisopropyldithio Zinc Carbamate Dibenzyldithiocarbamate Zinc, Sodium Diethyldithiocarbamate, Piperidine Pentamethylenedithiocarbamate, Selenium Dimethyldithiocarbamate, Tellurium Diethyldithiocarbamate, Diamyldithiocarb cadmium bamrate and mixtures thereof.

The aldehyde-amine or aldehyde-ammonia vulcanization accelerator may be selected from acetaldehyde-aniline reactants, butyraldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde-ammonia reactants, and mixtures thereof.

The imidazoline-based vulcanization accelerator may include an imidazoline-based compound such as 2-mercaptoimidazoline, and the xanthate-based vulcanization accelerator may include a xanthate-based compound such as zinc dibutylxantogenate.

The content of the vulcanization accelerator may be 1 to 3 parts by weight based on 100 parts by weight of the raw rubber in order to maximize the improvement of productivity and rubber properties by accelerating the vulcanization rate.

The vulcanization accelerator is a compounding agent used in combination with a vulcanization accelerator to completely promote the effect, and may be selected from inorganic vulcanization accelerators, organic vulcanization accelerators, and mixtures thereof.

The inorganic vulcanization accelerator may be selected from zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and mixtures thereof.

The organic vulcanization accelerator may be selected from stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, and mixtures thereof.

In particular, zinc oxide and stearic acid can be used together as a vulcanization accelerator, and in this case, zinc oxide is dissolved in stearic acid to form an effective complex with the vulcanization accelerator, which creates advantageous sulfur during the vulcanization reaction, thereby leading to a crosslinking reaction of rubber. facilitates

When zinc oxide and stearic acid are used together, the content of zinc oxide and stearic acid may be 1 to 3 parts by weight based on 100 parts by weight of raw rubber, respectively, so that they can serve as an appropriate vulcanization accelerator.

Meanwhile, the resin may be included in an amount of 6 to 10 parts by weight based on 100 parts by weight of raw rubber. The resin can improve the grip of the tire by coating the rubber surface. The resin may be, for example, α-Methylstyrene (AMS)-based resin.

Such a rubber composition for tire tread can be prepared by kneading each of the above-described components using a known device (eg, intermeshing type mixer, kneader, roll, etc.).

tire

The tire of the present invention is a tire made from the rubber composition described above. In the tire of the present invention, the above-described rubber composition according to various embodiments of the present invention may be used in the tire tread part.

2 is a diagram schematically showing a tire according to an embodiment of the present invention.

Referring to FIG. 2 , the tire 10 includes a tread part 100 , a sidewall part 200 and a bead part 300 .

The tread portion 100 is a portion in contact with the ground in cross section, and serves to protect the tire from impact and trauma from the road surface. A plurality of blocks partitioned by grooves may be formed on the surface of the tread portion as described above to improve drainage of the tire.

The tread part 100 includes the rubber composition according to an embodiment of the present invention. The tread unit 100 of the present invention may have a lower tread depth than the conventional tread unit. For example, the tread part 100 of the present invention may have a depth of 6.0 mm to 8.0 mm. Through this, weight can be saved, and dust generated during tire wear can also be reduced, making it eco-friendly.

Sidewalls 200 and bead parts 300 are sequentially positioned on both sides of the tread part 100 along the width direction of the tire.

The sidewall 200 is a part extending from both ends of the tread part 100 to form the side surface of the tire, and endures the contraction and expansion actions continuously repeated during driving, and the carcass layer 400 located on the inner side serves to protect

The bead part 300 is provided at both ends of the sidewall 200 to surround the end of the cord paper, and the bead part 300 includes a bead core 500 including a ring-shaped steel wire. In addition, in the bead portion 300, a rim cushion (not shown) is disposed at a portion in contact with the rim.

The carcass layer 400 is located between the left and right pair of bead parts 300, and is bonded to the tire rubber sheet inside the tire to form the skeleton of the tire, and the carcass layer 400 forms the bead core 500 It winds up from the inside of the tire to the outside.

An inner liner 700 is located on one side of the inside of the carcass layer 400 and serves to prevent air inside the tire from escaping to the outside.

On the outer surface of the carcass layer 400 located on the tread part 100, a belt layer 600 is positioned as a reinforcing layer to increase the elasticity of the tread and to have maneuverability and stability.

The belt layer rubber may contain a cobalt compound, and the cobalt compound is a cobalt salt, cobalt-boron ester, organic cobalt salt, inorganic cobalt salt, non-cobalt salt, etc. As the adhesive system, cobalt salt alone, cobalt-RH , In addition to cobalt-HRH, resin [e.g., methylene acceptor: phenolic, resorcinol-based, cresol-based, etc., or donor: hexamethylenetetraamine (HMT), hexamethoxymethylmelamine (HMMA), pentamethoxymethylmelamine (PMMA)] and the like.

In general, in order to improve adhesion, the adhesive system of adhesive compounded rubber is improved (cobalt-RH, cobalt-HRH, and their modified systems), resins used as adhesive aids are improved and performance is improved, cobalt salts used as adhesive aids are improved, and adhesion Improvement of rubber vulcanization system, use of new compound composition (reinforcement, carbon black, silica, polymer, chemicals), etc. are being used.

The content of the cobalt compound may include 0.2 to 5.0 parts by weight based on 100 parts by weight of raw rubber, but is not limited thereto.

A cap ply 800 including a hybrid cord may be disposed between the belt layer 600 and the tread portion 100 . The cap ply 800 can maintain the performance of the tire by suppressing the flow of the belt layer 600 during driving.

Tires according to various embodiments of the present invention may use the above-described tire rubber composition when forming a green tire. As a method of forming a green tire using the tire rubber composition of the present invention, any method conventionally used for manufacturing tires can be applied, and thus detailed descriptions thereof are omitted herein.

In FIG. 2, a tire for a passenger car is exemplified, but is not limited thereto, and may be a tire for a passenger car, a tire for racing, an airplane tire, a tire for agricultural machinery, an off-the-road tire, a truck tire, or a bus tire. there is. Also, the tire may be a radial tire or a bias tire, and is preferably a radial tire.

The present invention is explained in more detail through the following Examples and Comparative Examples. However, the examples are for exemplifying the present invention, and the scope of the present invention is not limited only thereto.

EXAMPLES - PREPARATION OF A RUBBER COMPOSITION

Each of the components in Table 1 below was added to a Banbury mixer in the ratios (unit: parts by weight) and mixed. After all ingredients were put into a mixer of intermeshing type, the ratio of each ingredient was adjusted so that the fill factor of 1.65L capacity was 0.65 to 0.70.

The mixing step was carried out in two steps, and the first step was the step of introducing rubber, filler and other chemicals (non-productive mixing step), and mixing was performed while maintaining the silane reaction section for 180 seconds at a mixing temperature of 140 ° C. .

The second step is a step of adding a vulcanizing agent (sulfur, sulfur) and a vulcanization accelerator to the mixture of the first step (productive step), and the mixture was mixed at about 120 seconds and 100 ° C. and then dropped.

division comparative example Example Natural rubber ¹⁾ 20.00 - Terminal degeneration S-SSR ²⁾ 80.00 - New S-SSR ³⁾ - 70.00 Butyl rubber ⁴⁾ - 30.00 carbon black ⁵⁾ 5.00 5.00 Silica ⁶⁾ 90.00 80.00 Coupling agent ⁷⁾ 7.20 8.00 zinc oxide ⁸⁾ 2.00 2.00 stearic acid ⁹⁾ 2.00 2.00 Accelerator ¹⁰⁾ 2.00 2.00 wax ¹¹⁾ 2.00 2.00 Resin ¹²⁾ 8.00 8.00 oil ¹³⁾ 36.00 36.00 Sulfur ¹⁴⁾ 1.40 1.40

1) Natural rubber: CHANA S.T.R

를 가지며, 분자 사슬의 단말단에 변성되었으며, 용액중합법으로 만든 스티렌-부타디엔 고무 (SLR4602, TRINSEO사)2) S-SBR: weight average molecular weight 479,100g/mol, molecular weight distribution 1.21, styrene content 21%, vinyl content 60%, glass transition temperature -26

Styrene-butadiene rubber (SLR4602, TRINSEO) made by solution polymerization and modified at the end of the molecular chain.

를 가지며, 분자 사슬의 양말단에 변성기를 부여하였으며, Batch-like continuous로 제조한 스티렌-부타디엔 고무 3) New S-SBR: weight average molecular weight 710,000 g/mol, molecular weight distribution 1.6, styrene content 36%, vinyl content 26%, TDAE oil content 20.0 phr, glass transition temperature -35

Styrene-butadiene rubber manufactured by batch-like continuous

4) Butyl rubber: It is a material polymerized under an alkyllithium (alkyllithium) catalyst and has a cis content of 40.5%, a vinyl content of 11.4%, and a modified butyl rubber at the ends.

5) Carbon black: Iodine adsorption value 120mg/g, oil adsorption specific surface area (DBP) 125cc/100g, pore density 320Kg/m ³ (N-234, Hyundai OCI)

6) Silica: Silica: Silica with a nitrogen adsorption specific surface area of 170 m ² /g and a CTAB adsorption specific surface area of 160 m ² /g (7000 HD-165GRN, manufactured by EVONIK UNITED SILICA (SIAM))

7) Coupling agent (silane coupling agent): A tetrasulfide-based compound having a sulfur content of 23% by weight and a molecular weight of 535 g/mol (Si69 ^® , Evonik)

8) Zinc oxide: ZnO KS#2, Hanil Chemical Industry Co., Ltd.

9) Stearic Acid: Stearic Acid, LG HOUSEHOLD & HEALTH CARE

10) Accelerator: Zinc soap from STRUKTOL

11) Wax: Anti-aging agent Parrafine wax (SUNOC #315, Daeunsa Co., Ltd.)

12) Resin: SA-85 from KRATON

13) Oil: Residual Aromatic Extract (RAE Oil, Korea Shell Oil Co., Ltd.)

14) Sulfur (vulcanizing agent): Ground sulfur, oil 1% (Miwon Corporation)

Evaluation Example 1 - Evaluation of properties of vulcanized rubber

Each of the tire rubber compositions prepared in Table 1 was press-vulcanized in a mold (15 cmХ15 cmХ0.2 cm) at 165 ° C. for 10 minutes with a force of 100 tons to prepare vulcanized rubber.

The hardness, 300% modulus, tensile strength, elongation, viscoelasticity and abrasion of each vulcanized rubber were measured in the following manner, and the results are shown in Table 2.

HD (hardness)

Hardness was measured by a shore A type hardness tester. Hardness indicates the steering stability by the degree of hardness of the specimen, and the higher the value, the better the steering stability.

300% modulus

The 300% modulus was measured according to ASTM standard D412 as the tensile strength at 300% elongation, and the higher the value, the better the strength.

Tensile properties

Tensile strength of the crosslinked specimen was measured using a tensile tester (INSTRON) according to ASTM D412. The specimen for measurement was manufactured in a sheet form using a hydraulic press and produced in a dumbbell form using a specimen cutter. As for the test conditions, the tensile speed was measured at 500 mm/min at room temperature. Tensile strength (T/S) is a value representing the stress value until the test piece breaks in the tensile tester, and the force received per unit area was measured.

Elongation

Elongation was measured by a method of expressing the strain value in % until the test piece breaks in a tensile tester.

Viscoelasticity (Viscoelastomer)

For viscoelasticity, Tanδ values were measured from -80°C to 70°C under a 10Hz Frequency at 0.2% strain using a Gabo viscometer. At this time, the temperature at which the Tanδ value is the largest is defined as the glass transition temperature, and the smaller the Tanδ value at 60° C., the less heat generated during driving and the better the rolling resistance.

Wear (index)

It was measured using a LAT-100 abrasion tester, and the higher the abrasion resistance index, the better the abrasion resistance.

division comparative example Example Hardness (Shore A) 64 62 300% Modulus (kgf/cm ² ) 121 103 Tensile strength (kgf/cm ² ) 160 187 Elongation (%) 380 460

tanδ @ 60

0.100 0.082 Wear (index) 100 130

Referring to Table 2, it can be seen that tanδ60 ° C, which is a substitute characteristic of rolling resistance, is improved by 18%, and the LAT-100 characteristic, which is a substitute characteristic of wear performance, is improved by 30% in the example compared to the comparative example. In addition, it was confirmed that the hardness and 300% modulus were at the same level, and it could be seen that the tensile strength and elongation were improved.

Evaluation Example 2 - Tire Evaluation

A tire tread was prepared from the rubber compositions of the comparative examples and examples in Table 1, and a 215/60R16V standard tire containing the tread rubber as a semi-finished product was manufactured, and for this tire, vehicle wear performance, fuel economy performance, dry road braking, Wet braking, dry and wet handling were evaluated. The results are shown in Table 3 below.

division comparative example Example Actual vehicle wear performance (index) 100 115 Fuel economy performance (index) 100 101 Dry braking (index) 100 99 Wet braking (index) 100 101 Dry and wet road handling (index) 100 100

Referring to Table 3, as a result of the actual vehicle wear evaluation (our company's general road surface condition, 12,000 km), the wear performance was improved by 15% compared to the comparative example, and the fuel economy, braking, and handling performance were confirmed to be at the same level.

So far, the present invention has been looked at with respect to its preferred embodiments. Those skilled in the art to which the present invention pertains will be able to understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent scope will be construed as being included in the present invention.

10: tire
100: tread part
200: side wall
300: bead part
400: carcass layer
500: bead core
600: belt layer
700: inner liner
800: cap ply

Claims (8)

a novel styrene-butadiene rubber comprising a styrene content of 33% to 40% by weight and a vinyl content of 20% to 30% by weight; and
100 parts by weight of raw rubber including butyl rubber polymerized under an alkyllithium catalyst, having a cis content of 30% to 50% by weight, and a vinyl content of 5% to 15% by weight,
The novel styrene-butadiene rubber,
TDAE (treated distillate aromatic extracted) oil is included at 10 phr to 30 phr, characterized in that both ends are denatured,
The butyl rubber is a rubber composition for tire tread, characterized in that the end is modified. According to claim 1,
The styrene-butadiene rubber is contained in 60 parts by weight to 80 parts by weight based on 100 parts by weight of the raw rubber, a rubber composition for tire tread. According to claim 1,
The butyl rubber is contained in 20 parts by weight to 40 parts by weight based on 100 parts by weight of the raw rubber, a rubber composition for tire tread. delete delete delete According to claim 1,
With respect to 100 parts by weight of the raw rubber,
3 to 7 parts by weight of carbon black,
75 to 85 parts by weight of silica,
6 to 10 parts by weight of a coupling agent,
1 to 3 parts by weight of zinc oxide;
1 to 3 parts by weight of stearic acid;
1 to 3 parts by weight of a vulcanization accelerator,
1 to 3 parts by weight of wax,
6 to 10 parts by weight of resin;
A rubber composition for tire tread, containing 0.5 to 2 parts by weight of sulfur. A tire manufactured from the rubber composition for tire tread according to any one of claims 1 to 3 and claim 7.

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