KR102261767B1 - Winter rubber composition with improved fuel efficiency and winter tire manufactured from it - Google Patents

Abstract

A rubber composition for a tire tread according to an embodiment of the present invention comprises 100 parts by weight of raw rubber containing solution-polymerized styrene-butadiene rubber (S-SBR) with both ends modified and modified functionalized third monomer imparted, wherein the glass transition temperature of the solution-polymerized styrene-butadiene rubber is -80 to -40°C. The tire according to an embodiment of the present invention is prepared from the rubber composition for a tire tread of the present invention.

Description

Winter rubber composition with improved fuel efficiency and winter tire manufactured from it}

The present invention relates to a rubber composition for a tread of a winter tire with improved fuel efficiency, including a novel synthetic rubber, and a winter tire manufactured therefrom.

Nowadays, exhaust gas regulations are getting stricter, and it is a very important technical task to improve fuel efficiency by reducing the rolling resistance of tires installed in automobiles.

Since the tread part occupies the most weight in the tire, it has the greatest influence on fuel efficiency performance.

Synthetic rubber solution-polymerized styrene-butadiene rubber (S-SBR) is widely used in the tread to improve braking performance.

In particular, since the rubber composition for winter tires is designed to have a low glass transition temperature (Tg), styrene-butadiene rubber having a low glass transition temperature is manufactured and used by designing the styrene and vinyl content of the raw rubber to be low. .

In addition, in order to improve abrasion resistance, braking performance, and fuel efficiency, styrene-butadiene rubber is applied to the tread by imparting modifiers to the terminal end or both ends of the molecular chain to the styrene-butadiene rubber, but the demand for improved performance is continuously emerging.

An object of the present invention is to provide a rubber composition for a tread of a winter tire having excellent abrasion resistance, braking performance and fuel efficiency, and having reduced rolling resistance, and a winter tire manufactured therefrom.

The rubber composition for a tread of a winter tire according to an embodiment of the present invention has both ends modified and solution-polymerized styrene-butadiene rubber (S-SBR) to which a modified Functionalized third monomer is given. 100 parts by weight of a raw rubber containing a, and the solution-polymerized styrene-butadiene rubber has a glass transition temperature of -80°C to -40°C.

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

The winter tire rubber composition according to various embodiments of the present invention has excellent braking force and high control stability on ice and snow, and high abrasion resistance.

A winter tire using the winter tire rubber composition according to various embodiments of the present invention has excellent abrasion resistance, braking characteristics, and fuel efficiency on ice and snow.

1 is a diagram schematically showing a solution-polymerized styrene-butadiene rubber modified at both ends according to an embodiment of the present invention.
2 is a view schematically showing the structure of a tire according to an embodiment of the present invention.

In the present invention, a winter compound with improved fuel efficiency that can be actually applied and used in tires was manufactured by checking the basic performance level using a novel synthetic rubber.

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

Since the creative idea disclosed in this specification is capable of various transformations and can have various implementations, specific implementations are described in detail in the detailed description and, if necessary, specific implementations are illustrated in the drawings. Effects and characteristics of the inventive idea of the present specification, and a method of achieving them will become clear with reference to the embodiments described below in detail in conjunction with the drawings. However, the inventive concept 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, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense.

In the following embodiments, the singular expression includes the plural expression unless the context clearly dictates otherwise.

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

Where one embodiment is otherwise feasible, 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 opposite to the order described.

Hereinafter, if necessary, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, identical or corresponding components are given the same reference numerals, and overlapping descriptions thereof will be omitted. do it with

In the drawings, the size of the 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 indicated for convenience of description, the inventive concept disclosed herein is not necessarily limited to the illustrated bar.

Rubber composition for winter tire tread

The rubber composition for a winter tire tread according to an embodiment of the present invention includes 100 parts by weight of a raw rubber, and the raw rubber includes a newly synthesized solution-polymerized styrene-butadiene rubber (S-SBR).

The raw rubber serves as a base of the rubber composition for a tread of a winter tire, and serves to impart basic performance, for example, braking force, steering stability, and the like, to the tire.

Meanwhile, referring to FIG. 1 , the newly synthesized solution-polymerized styrene-butadiene rubber may be a rubber in which both ends are modified and a modified Functionalized third monomer is applied.

Specifically, since the provision of a modifier can be applied only to the end of a molecular chain, it was possible to impart a modifier to only one or both ends of the chain with the prior art. In order to overcome this limitation, the first molecular chain was made using an initiator, and a modified oligomeric monomer was added to the end, not a modified group. Two polymer chains were simultaneously provided at the end of the oligomer monomer, and a total of three modifiers were provided by applying a modifier to each end of the polymer chain.

The solution-polymerized styrene-butadiene rubber may be a rubber prepared by using a third modified monomer in the process of attaching the modified molecular chain to both ends to the main molecular chain. This solution-polymerized styrene-butadiene rubber may have a three-arm constructure.

In the present invention, both ends of the solution-polymerized styrene-butadiene rubber are modified with functional groups and at the same time, the modified third monomer is added to the middle position of the main chain, thereby improving the abrasion resistance of the tire and improving fuel efficiency, especially in ice and snow. It has excellent braking force and high control stability from above, and high wear resistance.

In this case, both ends may be modified with one or more functional groups 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 solution-polymerized styrene butadiene rubber may be modified with the same or different functional groups. For example, both ends of the solution-polymerized styrene butadiene rubber may be modified with the same carboxyl group. For example, one end of the solution-polymerized styrene butadiene rubber may be modified with a carboxy group and the other end may be modified with a hydroxyl group.

The solution-polymerized styrene-butadiene rubber may have a weight average molecular weight of 500,000 g/mol to 600,000 g/mol, and a molecular weight distribution of 1.0 to 2.0. When the weight average molecular weight and molecular weight distribution of the solution-polymerized styrene-butadiene rubber are within the above ranges, there is an excellent effect in abrasion resistance, braking performance and fuel economy performance.

The solution-polymerized styrene-butadiene rubber may have a styrene content of 5 wt% to 15 wt%, and a vinyl content of 30 wt% to 50 wt%. When the solution-polymerized styrene-butadiene rubber has a styrene content and a vinyl content within the above ranges, hysteresis of the rubber may be reduced to improve fuel economy performance.

The solution-polymerized styrene-butadiene rubber may have a glass transition temperature of -80°C to -40°C. In the case of having a glass transition temperature within the above range, the fluidity of the rubber is increased at room temperature, so that the cut and chip performance, abrasion performance, and low fuel efficiency performance can be improved by reducing the hysteresis loss. In addition, the snow performance can be improved when the composition of the present invention is applied to winter tires.

The solution-polymerized styrene-butadiene rubber may be manufactured by a continuous method or a batch method.

According to an embodiment, the solution-polymerized styrene-butadiene rubber may be continuously polymerized. The solution-polymerized styrene-butadiene rubber produced by the continuous method has somewhat disadvantageous processability due to its long molecular chain compared to the solution-polymerized styrene-butadiene rubber produced by the batch method, but is advantageous in abrasion resistance due to its high molecular weight.

The solution-polymerized styrene-butadiene rubber may be included in an amount of 30 to 100 parts by weight based on 100 parts by weight of the raw rubber. For example, it may be included in an amount of 40 to 100 parts by weight based on 100 parts by weight of the raw rubber. When the content of the solution-polymerized styrene-butadiene rubber is less than 30 parts by weight, abrasion resistance and fuel economy performance may be deteriorated.

In addition, the newly synthesized solution-polymerized styrene-butadiene rubber described above as the raw material rubber can be used alone, and in some cases, it is mixed with emulsion-polymerized styrene-butadiene rubber having a low glass transition temperature (Tg) (Low Tg solution styrene butadiene rubber). can be used by

For example, by partially applying emulsion-polymerized styrene-butadiene rubber for designing a tread rubber for a winter tire, excellent fuel economy performance on ice and snow, and abrasion performance can be improved.

The emulsion-polymerized styrene-butadiene rubber may be included in an amount of 20 to 50 parts by weight based on 100 parts by weight of the raw rubber. If the ?t amount of the emulsion-polymerized styrene-butadiene rubber is less than 20 parts by weight or exceeds 50 parts by weight, it may be difficult to apply to snow tires.

The weight average of the emulsion-polymerized styrene-butadiene rubber is 750,000 g/mol to 950,000 g/mol, and the glass transition temperature may be -130°C to -190°C. When the weight average molecular weight and the glass transition temperature of the emulsion-polymerized styrene-butadiene rubber are within the above ranges, there is an excellent effect in the abrasion resistance, braking performance and fuel efficiency of the winter tire.

The emulsion-polymerized styrene-butadiene rubber may contain 25 to 45 parts by weight of oil based on 100 parts by weight of the emulsion-polymerized styrene-butadiene rubber. For example, the emulsion-polymerized styrene-butadiene rubber may include treated distillate aromatic extracted (TDAE) oil, and the TDAE oil may be included in an amount of 25 to 45 parts by weight based on 100 parts by weight of the emulsion-polymerized styrene-butadiene rubber. When the oil content contained in the emulsion-polymerized styrene-butadiene rubber is within the above range, there is an excellent effect in the abrasion resistance, braking performance and fuel efficiency of the winter tire.

The emulsion-polymerized styrene-butadiene rubber may have a 1,4-cis (Cis) content of 94 wt% to 98 wt%. When the emulsion-polymerized styrene butadiene rubber has a 1,4-cis (Cis) content within the above range, hysteresis of the rubber may be reduced to improve low fuel consumption performance.

In addition, the raw rubber may further include a solution-polymerized styrene-butadiene rubber modified at the terminal end.

For example, by partially applying a solution-polymerized styrene-butadiene rubber modified at the terminal end to design a tread rubber for a winter tire, it is possible to improve fuel efficiency and abrasion performance, followed by snow performance.

The terminal end-modified solution-polymerized styrene-butadiene rubber may be included in an amount of 10 to 30 parts by weight based on 100 parts by weight of the raw rubber. If the ?t amount of the solution-polymerized styrene-butadiene rubber modified at the terminal end is less than 10 parts by weight or exceeds 30 parts by weight, it may be difficult to apply to snow tires.

The terminal end-modified solution-polymerized styrene-butadiene rubber may have a weight average of 950,000 g/mol to 1,150,000 g/mol, and a glass transition temperature of -40°C to -20°C. When the weight average molecular weight and the glass transition temperature of the terminal end-modified solution-polymerized styrene-butadiene rubber are within the above ranges, there is an excellent effect in the abrasion resistance, braking performance and fuel efficiency of the winter tire.

The terminal-modified solution-polymerized styrene-butadiene rubber may contain 15 to 35 parts by weight of oil based on 100 parts by weight of the terminal-modified solution-polymerized styrene-butadiene rubber. When the oil content included in the terminal end-modified solution-polymerized styrene-butadiene rubber is within the above range, there is an excellent effect in the abrasion resistance, braking performance and fuel efficiency of the winter tire.

The terminal-end-modified solution-polymerized styrene-butadiene rubber may have a styrene content of 25 wt% to 45 wt%. When the terminal-end-modified solution-polymerized styrene-butadiene rubber has a styrene content within the above range, hysteresis of the rubber may be reduced to improve low fuel consumption performance.

The rubber composition for a 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 105 to 125 m 2 /g, and a cetyltrimethyl ammonium bromide (CTAB) adsorption specific surface area of 100 to 120 m 2 /g. Since the silica used in the rubber composition for a tire tread of the present invention has a large specific surface area, it is possible to improve the abrasion resistance and braking performance of the tire.

Silica may be included in an amount of 70 to 110 parts by weight based on 100 parts by weight of the raw rubber. When the content of silica is within the above range, braking and abrasion resistance may be improved, and if the content of silica is less than 70 parts by weight or exceeds 110 parts by weight, fairness may be significantly deteriorated.

The silica may be surface-treated with a silane coupling agent, and a tetrasulfide-based compound may be used as the silane coupling agent. The tetrasulfide-based compound may have a sulfur content of 21 wt% to 25 wt%, and a molecular weight of 500 g/mol to 550 g/mol. The coupling agent may be surface-treated using 5 to 20 parts by weight based on 100 parts by weight of silica.

The rubber composition for a tire tread according to various embodiments of the present invention may include carbon black as a filler.

Carbon black can improve the appearance characteristics of the tire tread, such as preventing deterioration of wear performance due to the use of silica, and increasing the degree of coloration by developing black. In addition, the mixing temperature rises compared to when silica alone is used, thereby preventing scorch and weakening of the bonding between silica and the silane coupling agent.

The rubber composition for a 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 longevity of tires. The antioxidant 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 For example, all three substances may be included as an anti-aging agent.

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, and tetramethylthiuram disulfide (TMTD), tetraethylthi It may include an organic vulcanizing agent such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine, and other elements sulfur or a vulcanizing agent that produces sulfur, for example, amine disulfide, polymeric sulfur and the like.

In addition, organic peroxides include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl 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, or n-butyl-4,4-di-t-butylperoxyvalerate, and the like.

The content of the vulcanizing agent may be 0.5 to 10 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, it is possible to make the raw rubber less sensitive to heat and chemically stable as an appropriate vulcanizing effect.

The vulcanization accelerator refers to an accelerator that accelerates the vulcanization rate or promotes a delayed action in the initial vulcanization stage. The vulcanization accelerator is selected from among 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 selected.

Sulfenamide-based vulcanization accelerators include 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), dibenzothiazyldisulfide (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-diethyl4 -morpholinothio)benzothiazole and mixtures thereof.

Thiuram-based vulcanization accelerators are, for example, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuramhexasulfide, tetrabutylthiuramdisulfide, pentamethylenethiuramtetrasulfide and mixtures thereof.

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

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

The dithiocarbamic acid vulcanization accelerator is ethylphenyldithiocarbamate zinc, butylphenyldithiocarbamate zinc, dimethyldithiocarbamate sodium, dimethyldithiocarbamate zinc, diethyldithiocarbamate zinc, dibutyldithio Zinc carbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, complex salt of pentamethylenedithiocarbamate zinc and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecylisopropyldithio Zinc carbamate dibenzyldithiocarbamate, sodium diethyldithiocarbamate, pentamethylenedithiocarbamate piperidine, dimethyldithiocarbamate selenium, diethyldithiocarbamate tellunium, diamyldithiocarbamate cadmium bamate and mixtures thereof.

The aldehyde-amine-based or aldehyde-ammonia-based vulcanization accelerator may be selected from acetaldehyde-aniline reactants, butylaldehyde-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 dibutylxanthogenate zinc.

The content of the vulcanization accelerator may be 0.1 to 10 parts by weight based on 100 parts by weight of the raw rubber in order to maximize productivity and rubber properties through acceleration of the vulcanization rate.

The vulcanization accelerator is a compounding agent used in combination with a vulcanization accelerator to perfect the accelerating 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, as a vulcanization accelerator, zinc oxide and stearic acid can be used together. In this case, zinc oxide is dissolved in stearic acid to form an effective complex with the vulcanization accelerator, thereby generating advantageous sulfur during the vulcanization reaction, thereby causing a crosslinking reaction of rubber. to facilitate

When zinc oxide and stearic acid are used together, the content of zinc oxide and stearic acid may be 1 to 10 parts by weight based on 100 parts by weight of the raw rubber, respectively, so as to serve as an appropriate vulcanization accelerator.

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

winter tires

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

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

The tread includes the rubber composition according to an embodiment of the present invention.

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

The sidewall 200 is a portion extending from both ends of the tread to form the side surface of the tire, and serves to withstand the continuously repeated contraction and expansion action while driving, and to protect the carcass layer 400 located on the inner surface. do

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. Moreover, in the bead part 300, a rim cushion (not shown) is arrange|positioned at the part in contact with a rim.

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

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

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

The belt layer rubber may include a cobalt compound, and the cobalt compound is a cobalt salt, a cobalt-boron ester, an organic acid cobalt salt, an inorganic acid cobalt salt, a non-cobalt salt, and the like. In addition to RH, cobalt-HRH, resins [e.g., methylene acceptor: phenolic, resorcinol, cresol, etc., or donor: hexamethylenetetraamine (HMT), hexamethoxymethylmelamine (HMMA), pentamethoxymethyl There is an adhesive system modified with melamine (PMMA)].

In general, to improve adhesion, improvement of the adhesive system of adhesive compounded rubber (cobalt-RH, cobalt-HRH, their modified systems), improvement and performance improvement of resins used as adhesion aids, improvement of cobalt salts used as adhesion aids, adhesion Improvements in the vulcanization system of rubber and the use of new compounding compositions (reinforcing agents, carbon black, silica, polymers, chemicals) 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 the 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 part 100 . The cap ply 800 may suppress the flow of the belt layer 600 during driving to maintain the performance of the tire.

A tire according to another embodiment of the present invention includes the step of using the tire rubber composition when forming a green tire. Any method of forming a green tire using the tire rubber composition may be applied as long as it is a method conventionally used for manufacturing a tire, and a detailed description thereof will be omitted herein.

2 exemplifies a tire for a passenger car, but is not limited thereto, and may be a tire for a passenger car, a race tire, an airplane tire, a tire for an agricultural machine, an off-the-road tire, a truck tire, or a bus tire. have. Also, the tire may be a radial tire or a bias tire, preferably a radial tire.

The present invention will be described in more detail through the following examples and comparative examples. However, the examples are provided to illustrate the present invention, and the scope of the present invention is not limited thereto.

Example- Preparation of rubber composition

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

The mixing step was carried out in a total of two steps, and the first step was a step of adding rubber, fillers 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 (productive step) of adding a vulcanizing agent (sulfur) and a vulcanization accelerator to the mixture of step 1, mixing at a level of about 120 seconds and 100° C. and then dropping.

division Comparative Example 1 Example 1 Comparative Example 2 Example 2 end-end metamorphosis S-SBR ¹⁾
(content with oil) 20
(25) 20
(25) S-SBR ²⁾
(oil free) 100 50 Both ends and third monomer modified product S- SBR ³⁾ 100 50 BR ⁴⁾
(content with oil) 30
(41.25) 30
(41.25) carbon black ⁵⁾ 5 5 Silica ⁶⁾ 80 80 105 105 Silane coupling agent ⁷⁾ 6.4 6.4 8.0 8.0 stearic acid ⁸⁾ 2 2 One One zinc oxide ⁹⁾ 2 2 2 2 Anti-Aging 1 ¹⁰⁾ 2 2 2 2 Anti-Aging 2 ¹¹⁾ 2 2 2 2 Anti-Aging 3 ¹²⁾ One One 1.5 1.5 processing aid ¹³⁾ 3 3 oil ¹⁴⁾ 37.50 37.50 38.75 38.75 Sulfur ¹⁵⁾ 1.5 1.5 2.0 2.0 vulcanization accelerator 1 ¹⁶⁾ 2 2 One One vulcanization accelerator 2 ¹⁷⁾ 2 2 2 2

1) S-SBR: Weight average molecular weight 1,050,000 g/mol, molecular weight distribution 2.20, styrene content 36%, vinyl content 26%, oil 25 parts by weight (phr), has a glass transition temperature of -33°C, Styrene-butadiene rubber modified at the terminal end and made by solution polymerization (F3626Y, LG CHEMICAL)

2) S-SBR (oil-free): It has a weight average molecular weight of 560,000 g/mol, a molecular weight distribution of 1.40, a styrene content of 15%, a vinyl content of 30%, a glass transition temperature of -60 ° C, and is modified at the terminal end of the molecular chain. , Styrene-butadiene rubber made by solution polymerization (SLR3402, TRINSEO)

3) S-SBR: has a weight average molecular weight of 553,650 g/mol, a molecular weight distribution of 1.34, a styrene content of 10%, a vinyl content of 40%, a glass transition temperature of -60°C, both ends of the molecular chain are modified, and the modified third monomer new styrene-butadiene rubber made by solution polymerization (SOL5140X, Kumho Petrochemical)

4) Butadiene rubber: weight average molecular weight 860,000g/mol, molecular weight distribution 2.60, 1,4-cis content 96%, glass transition temperature -110 ℃, TDAE (Treated distillate aromatic extracted) oil Contains 37.5 parts by weight (phr), butadiene rubber polymerized with a neodymium catalyst (CB29, LANXESS)

5) Carbon black: Iodine adsorption value 90mg/g, oil adsorption specific surface area (DBP) 122cc/100g, pore density 340Kg/m ³ (N-339, Hyundai OCI)

6) Silica: Silica: Silica having a nitrogen adsorption specific surface area of 115 m ² /g and a CTAB adsorption specific surface area of 110 m ² /g (5000GR, EVONIK UNITED SILICA (SIAM))

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

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

10) Anti-aging agent 1: Parrafine wax (SUNOC #315, Daewoon Corporation)

11) Anti-aging agent 2: N-(1,3-dimethylbutyl)-N-phenylenediamine (DUSANTOX 6PPD, DUSLO)

12) Anti-aging agent 3: 2,2,4-trimethyl-1,2-dihydroquinoline (RD, SONGWON)

13) Processing aid 1: Fatty acid zinc oxide/potassium soap for improving processability and dispersibility (EF-44, Dongeun Chemical)

14) Oil: Residual Aromatic Extract (RAE Oil, Korea Shell Oil)

15) Vulcanizing agent (sulfur): Ground sulfur, oil 1% (Miwon Corporation)

16) Vulcanization accelerator 1: N-cyclohexyl-2-benzocyazoyl sulfenamide (CBS, SHANDONG SHANXIAN CHEMICALS)

17) Vulcanization accelerator 2: diphenylguanidine (DPG, SHANDONG SHANXIAN CHEMICALS)

Evaluation Example 1- Evaluation of physical properties of unvulcanized rubber

pattern (Mooney viscosity

The Mooney viscosity (ML 1+4 (100° C.) of the rubber composition for tires prepared in Table 1 was measured according to ASTM standard D1646, and is shown in Table 2).

ML1+4 is a value indicating the viscosity of the unvulcanized rubber, and the lower the value, the better the processability of the unvulcanized rubber.

Evaluation Example 2 Evaluation of Vulcanized Rubber Physical Properties

Each of the rubber compositions for tires prepared in Table 1 was press-cured in a mold (15cmХ15cmХ0.2cm) at 165° C. for 10 minutes with a force of 100 tons to prepare vulcanized rubbers, respectively.

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

HD (hardness)

Hardness was measured by a shore A type hardness machine. The hardness indicates the handling stability to the degree of hardness of the specimen, and the higher the value, the better the handling 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.

Elongation

The elongation was measured by a method in which the strain value until the specimen was broken in a tensile tester was expressed in %.

Tensile properties

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

Wear

The degree of abrasion was tested with an abrasion tester of Lambourn and William abrasion Tester. It is a measure of the loss of rubber worn at room temperature. The lower the number, the better the abrasion performance.

Viscoelasticity (Viscoelastomer)

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

division Comparative Example 1 Example 1 Comparative Example 2 Example 2 Mooney Viscosity (100℃) 85 93 66 69 Hardness (Shore A) 64 63 65 65 300% modulus (kgf/cm ² ) 102 111 92 93 Tensile strength (kgf/cm ² ) 183 189 192 199 Elongation (%) 430 420 510 510 Wear (Lambourn, %) 0.166 0.135 0.151 0.144 Wear (William, %) 0.372 0.361 0.228 0.209 Glass transition temperature (Tg) -34 -32 -31 -30 viscoelastic E' @ -30℃ 65 67 136 138 tanδ @ 0 ℃ 0.233 0.258 0.287 0.299 tanδ @ 60 ℃ 0.097 0.080 0.128 0.107

As shown in Table 2, both Examples 1 and 2 exhibited improved tensile strength compared to Comparative Examples 1 and 2, resulting in improved wear resistance in medium severity Lambourn and high severity (William).

In addition, both the viscoelastic braking substitute characteristics (tanδ@0℃) and fuel economy substitute characteristics (tanδ@60℃) were improved. In particular, in the case of fuel economy substitute characteristics, compared to Comparative Example 1 in which 100 parts by weight of S-SBR at the end of the oil-free modified product was applied, it was improved by about 18% in Example 1, and Comparative Example 2 in which 50 parts by weight of S-SBR at the end of the oil-free modified product was applied. Compared to Example 2, the result was improved by about 16%.

Evaluation Example 3 - Tire Evaluation

The fuel efficiency performance, grip, and braking of the tires manufactured using Comparative Examples 2 and 2 of Table 1 were evaluated. The results are shown in Table 3 below.

tire pattern N'PRIZ 4 SEASON tire size 205/60R16 96H XL evaluation version
(Based on Tables 1 and 2) Comparative Example 2 Example 2 Tire weight (kg) 9.82 9.86 fuel efficiency RRc ¹⁾ 8.40 8.16 Grade ²⁾ C C ??Grip ³⁾ G 1.26 1.25 Grade ²⁾ C C braking ⁴⁾ dry road surface
(asphalt) 48.20 47.40 wet road surface
(asphalt) 32.40 31.60

1) Performance evaluation method of rolling resistance coefficient: ISO28580 standard

2) Classification criteria: Europe

3) Wet Grip: Trailer method

4) Braking performance evaluation: Avante vehicle

Referring to Table 3, in the case of the tire manufactured using Example 2, compared to Comparative Example 2, dry road braking performance was improved by about 2%, wet road braking performance was improved by about 3%, and tire fuel efficiency improved by about 3%. results were shown.

So far, with respect to the present invention, the preferred embodiments have been looked at. Those of ordinary skill in the art to which the present invention pertains will 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 are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

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

Claims (12)

A modified third monomer (Functionalized third monomer) is given, two polymer chains are given to the end of the monomer, a carboxyl group is given to one end of the polymer chain, and a hydroxyl group is given to the other end of the solution-polymerized styrene- Contains 100 parts by weight of raw rubber containing butadiene rubber (Solution styrene butadiene rubber, S-SBR),
The solution-polymerized styrene-butadiene rubber comprises 40 parts by weight to 60 parts by weight based on 100 parts by weight of the raw rubber,
The glass transition temperature of the solution-polymerized styrene-butadiene rubber is -60 ℃ to -50 ℃, a rubber composition for a winter tire tread. delete According to claim 1,
The weight average molecular weight of the solution-polymerized styrene-butadiene rubber is 500,000 g/mol to 600,000 g/mol, a rubber composition for a winter tire tread. According to claim 1,
The solution-polymerized styrene-butadiene rubber has a molecular weight distribution of 1.0 to 2.0, a rubber composition for a winter tire tread. According to claim 1,
The solution-polymerized styrene-butadiene rubber has a styrene content of 5 wt% to 15 wt%, and a vinyl content of 30 wt% to 50 wt%, a rubber composition for a winter tire tread. delete According to claim 1,
The rubber composition for winter tire tread further comprising an emulsion-polymerized styrene-butadiene rubber having a low glass transition temperature (Tg). 8. The method of claim 7,
The emulsion-polymerized styrene-butadiene rubber is included in an amount of 30 to 50 parts by weight based on 100 parts by weight of the raw rubber, a rubber composition for a winter tire tread. 8. The method of claim 7,
The glass transition temperature of the emulsion-polymerized styrene-butadiene rubber is -130 ℃ to -110 ℃, the weight average molecular weight is 750,000 g / mol to 950,000 g / mol, a rubber composition for a winter tire tread. delete delete A winter tire manufactured from the rubber composition for a tire tread according to any one of claims 1, 3 to 5, and any one of claims 7 to 9.

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