KR102620796B1 - Rubber composition for tire belt and Tire comprising the same - Google Patents

Abstract

raw rubber; filler; and a hygroscopic monomer or hygroscopic polymer. A tire belt rubber composition comprising the rubber composition, a tire belt comprising the rubber composition, and a tire including the belt are provided.

Description

Tire belt rubber composition and tire comprising the same {Rubber composition for tire belt and Tire comprising the same}

It relates to a tire belt rubber composition and a tire containing the same.

In general, a tire belt functions to increase the rigidity of the tread section by overlapping steel cord layers. Accordingly, the belt rubber must have good adhesion to the steel cord and not deteriorate even during long-term driving. For this purpose, a belt rubber with high modulus and favorable fatigue performance is required.

Cobalt salt, which is common in steel cord coating rubber compounds, promotes the crosslinking reaction of sulfur, which is contained in large amounts in this rubber compound. This increase in crosslink density increases the pulling force between the rubber and steel cord.

More importantly, cobalt salt forms cobalt (Co) ions from the brass surface during the crosslinking reaction, which helps form copper sulfide (CuS).

The difference in efficiency between cobalt adhesion promoters lies in how quickly they form cobalt ions. For example, Zn or Brass works more easily with Coalt Boron Decanoate Complexes than with Cobalt Napthanate or Cobalt Stearate.

However, the adhesion between the cobalt compound and the steel cord weakens as the vehicle driving distance increases. This is an important issue as it relates to safety.

There may be several causes for this weakening of adhesion, but one of the causes is the penetration of water molecules [moisture]. Water molecules that penetrate into the belt layer act as a ligand and form a bond with the steel cord or cobalt metal, resulting in the -SH, -S- moiety of the polymer chain that was coordinating with the steel cord or cobalt metal. However, the double bond portions come apart, resulting in a decrease in bonding strength. Additionally, corrosion of steel cords due to water molecules [moisture] is a natural result.

Therefore, it is important to prevent the penetration and progression of water molecules into the steel belt layer.

One aspect is to provide a tire belt rubber composition having excellent wet heat adhesion.

Another aspect is to provide a tire belt containing the rubber composition.

Another aspect is to provide a tire equipped with the tire belt.

According to one aspect,

raw rubber; filler; and a hygroscopic monomer or hygroscopic polymer. A tire belt rubber composition comprising a hygroscopic monomer or hygroscopic polymer is provided.

According to one other aspect,

A tire belt comprising the tire belt rubber composition is provided.

According to another aspect,

A tire equipped with the tire belt is provided.

The tire belt rubber composition according to one embodiment of the present invention has excellent absorption ability for water molecules (moisture) and effectively inhibits the progression of water molecules penetrating into the steel belt layer. Therefore, it can greatly contribute to tire safety by preventing weakening of the adhesion between rubber and steel cord.

1 is a diagram schematically showing the structure of a tire according to an embodiment.

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

The creative idea disclosed in this specification can be subjected to various transformations and can have various implementation examples, and specific implementation examples are described in detail in the detailed description and, if necessary, specific implementation examples are illustrated in the drawings. The effects and features of the creative ideas of this specification and methods for achieving them will become clear by referring to the implementation examples described in detail below along with the drawings. However, the creative ideas of the present specification are not limited to the implementation examples disclosed below and may be implemented in various forms.

In the following implementation examples, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component.

In the following embodiments, singular terms include plural terms unless the context clearly dictates otherwise.

In the following implementation examples, terms such as include or have mean that the features or components described in the specification exist, and do not preclude the possibility of adding one or more other features or components.

In cases where an embodiment can be implemented differently, a specific process sequence may be performed differently from the described sequence. For example, two processes described in succession may be performed substantially at the same time, or may be performed in an order opposite to that in which they are described.

Hereinafter, when necessary, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. Do this.

In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are shown arbitrarily for convenience of explanation, so the creative ideas disclosed in this specification are not necessarily limited to what is shown.

A tire belt rubber composition according to one embodiment includes raw rubber; filler; and hygroscopic monomer or hygroscopic polymer.

According to one embodiment of the present invention, the hygroscopic monomer has a reactive double bond; And it may include an OH group or NH ₂ group.

According to one embodiment of the present invention, the hygroscopic polymer may include an alkyl chain containing an OH group.

For example, the hygroscopic monomer may include acrylic acid, acrylamide, or any combination thereof.

Acrylic acid is a compound with the following structure,

Acrylamide is a compound with the following structure.

For example, the hygroscopic polymer may include polyvinyl alcohol.

Polyvinyl alcohol is a compound with the following structure.

The average molecular weight of polyvinyl alcohol is 4000 to 60000, and n is the corresponding natural number.

The tire belt rubber composition according to one embodiment of the present invention contains a hygroscopic monomer or a hygroscopic polymer, thereby blocking the movement of moisture that may infiltrate from the external environment or moisture present inside the belt rubber composition.

Water molecules that penetrate into the belt layer act as a ligand and form a bond with the steel cord or cobalt metal, resulting in the -SH, -S- moiety of the polymer chain that was coordinating with the steel cord or cobalt metal. However, the double bond portions come apart, resulting in a decrease in bonding strength.

The hygroscopic monomer can block the movement of water molecules when combined with the raw rubber, and when the hygroscopic polymer is mixed with the raw rubber. As a result, corrosion of the steel cord can be prevented and deterioration of the adhesion between rubber and steel cord can be prevented.

According to one embodiment of the present invention, the belt rubber composition may include 0.5 to 1.2 parts by weight of a hygroscopic monomer or hygroscopic polymer based on 100 parts by weight of raw rubber. If the amount is less than 0.5 parts by weight, the moist heat anti-aging effect is not observed, and if it exceeds 1.2 parts by weight, the rubber properties deteriorate.

According to one embodiment of the present invention, the rubber composition may include natural rubber as a raw rubber. For example, the raw rubber of the rubber composition may be made of natural rubber. The natural rubber may be general natural rubber or modified natural rubber.

The general natural rubber can be used as long as it is known as natural rubber, and its place of origin is not limited. The natural rubber mainly contains cis-1,4-polyisoprene, but may also contain trans-1,4-polyisoprene depending on required properties. Accordingly, the above-mentioned natural rubber includes, in addition to natural rubber containing cis-1,4-polyisoprene as a main body, natural rubber containing trans-1,4-isoprene as a main body, such as balata, a type of rubber of the Sapotaceae family from South America. It may also contain rubber.

The modified natural rubber refers to the general natural rubber that has been modified or refined. For example, the modified natural rubber includes epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), and hydrogenated natural rubber.

According to one embodiment of the present invention, the rubber composition may include a filler, for example, carbon black.

The carbon black may have a nitrogen adsorption specific surface area per gram (N ₂ SA) of 30 to 300 m ² /g and a DBP (n-dibutyl phthalate) oil absorption of 60 to 180 cc/100 g, but according to the present invention This is not limited to this.

If the nitrogen adsorption specific surface area of the carbon black exceeds 300 m ² /g, the processability of the rubber composition for tires may be disadvantageous, and if it is less than 30 m ² /g, the reinforcement performance by carbon black as a filler may be disadvantageous. In addition, if the DBP oil absorption of the carbon black exceeds 180cc/100g, the processability of the rubber composition may be reduced, and if it is less than 60cc/100g, the reinforcement performance by the carbon black as a filler may be disadvantageous.

Representative examples of the carbon black include N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N320, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550. , N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991.

The carbon black may be included in an amount of 30 to 80 parts by weight, preferably 45 to 75 parts by weight, and more preferably 53 to 67 parts by weight, based on 100 parts by weight of the raw rubber. If the carbon black content is less than 30 parts by weight, the reinforcing performance by carbon black as a filler may be reduced, and if it exceeds 80 parts by weight, the processability of the rubber composition may be disadvantageous.

The tire belt rubber composition may optionally further include various additives such as additional vulcanizing agent, vulcanization accelerator, vulcanization accelerator aid, anti-aging agent, antioxidant, or softener. Any of the above various additives can be used as long as they are commonly used in the field to which the present invention pertains, and their content is not particularly limited as it depends on the mixing ratio used in a typical tire belt rubber composition.

As the vulcanizing agent, a sulfur-based vulcanizing agent can be preferably used. The sulfur-based vulcanizing agent includes inorganic vulcanizing agents such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), and colloidal sulfur, tetramethylthiuram disulfide (TMTD), and tetraethyl Organic curing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. As the sulfur vulcanizing agent, elemental sulfur or a vulcanizing agent that produces sulfur, for example, amine disulfide, polymer sulfur, etc. may be used.

The vulcanizing agent is preferably included in an amount of 0.5 to 10.0 parts by weight based on 100 parts by weight of the raw rubber in order to achieve an appropriate vulcanization effect and makes the raw rubber less sensitive to heat and chemically stable.

The vulcanization accelerator refers to an accelerator that accelerates the speed of vulcanization or promotes a delay in the initial vulcanization stage.

The vulcanization accelerators include sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, xanthate-based and these. Any one selected from the group consisting of combinations may be used.

The sulfenamide-based vulcanization accelerators include, for example, N-cyclohexyl-2-benzothiazylsulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and N,N-dicyclohexyl. -2-benzothiazylsulfenamide, N-oxydiethylene-2-benzothiazylsulfenamide, N,N-diisopropyl-2-benzothiazolesulfenamide, and any one selected from the group consisting of combinations thereof. Sulfenamide-based compounds can be used.

The thiazole-based vulcanization accelerator includes, for example, 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, and zinc salt of 2-mercaptobenzothiazole. , copper salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(2,6-di Any one thiazole-based compound selected from the group consisting of ethyl4-morpholinothio)benzothiazole and combinations thereof can be used.

The thiuram-based vulcanization accelerator includes, for example, tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, and dipentamethylene. Any one thiuram-based compound selected from the group consisting of thiuram tetrasulfide, dipentamethylenethiuramhexasulfide, tetrabutylthiuram disulfide, pentamethylenethiuramtetrasulfide, and combinations thereof can be used.

The thiourea-based vulcanization accelerator includes, for example, any thiourea-based agent selected from the group consisting of thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and combinations thereof. Compounds can be used.

As the guanidine-based vulcanization accelerator, for example, any guanidine-based compound selected from the group consisting of diphenylguanidine, diorthotolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate, and combinations thereof may be used. You can.

The dithiocarbamate-based vulcanization accelerators include, for example, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, complex salt of zinc pentamethylenedithiocarbamate and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecyl Zinc isopropyldithiocarbamate, Zinc dibenzyldithiocarbamate, Sodium diethyldithiocarbamate, Piperidine pentamethylenedithiocarbamate, Selenium dimethyldithiocarbamate, Tellurium diethyldithiocarbamate, Dia. Any dithiocarbamate-based compound selected from the group consisting of cadmium milddithiocarbamate and combinations thereof can be used.

The aldehyde-amine or aldehyde-ammonia vulcanization accelerator includes, for example, an aldehyde selected from the group consisting of acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde-ammonia reactant, and combinations thereof. -Amine-based or aldehyde-ammonia-based compounds can be used.

As the imidazoline-based vulcanization accelerator, for example, imidazoline-based compounds such as 2-mercaptoimidazoline can be used, and as the xanthate-based vulcanization accelerator, for example, xanthate-based compounds such as zinc dibutylxanthogenate. Compounds can be used.

The vulcanization accelerator may be included in an amount of 0.5 to 4.0 parts by weight based on 100 parts by weight of the raw rubber in order to maximize productivity and rubber physical properties through acceleration of vulcanization speed.

The vulcanization accelerator is a compounding agent used in combination with the vulcanization accelerator to completely enhance its accelerating effect. Any one selected from the group consisting of inorganic vulcanization accelerator, organic vulcanization accelerator, and combinations thereof may be used. .

The inorganic vulcanization accelerator may be any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide, and combinations thereof. there is. The organic vulcanization accelerator is selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, and combinations thereof. You can use any one that works.

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

When the zinc oxide and the stearic acid are used together, they can be used in an amount of 1 to 10 parts by weight and 0.5 to 3 parts by weight, respectively, based on 100 parts by weight of the raw rubber to serve as an appropriate vulcanization accelerator. If the content of zinc oxide and stearic acid is less than the above range, the vulcanization speed may be slow and productivity may be reduced, and if it exceeds the above range, a scorch phenomenon may occur and physical properties may be reduced.

The softener is added to the rubber composition to provide plasticity to the rubber to facilitate processing or to reduce the hardness of vulcanized rubber, and refers to oils and other materials used when mixing rubber or manufacturing rubber. The softener refers to process oil or other oils included in the rubber composition. The softener may be any one selected from the group consisting of petroleum oil, vegetable oil, and combinations thereof, but the present invention is not limited thereto.

The petroleum oil may be any one selected from the group consisting of paraffin oil, naphthenic oil, aromatic oil, and combinations thereof.

Representative examples of the paraffinic oil include P-1, P-2, P-3, P-4, P-5, and P-6 of Michang Oil Co., Ltd., and representative examples of the naphthenic oil include Michang Oil. Examples include N-1, N-2, N-3, etc. from Co., Ltd., and representative examples of the aromatic oil include A-2, A-3, etc. from Michang Oil Co., Ltd.

However, with the recent increase in environmental awareness, it is known that when the content of polycyclic aromatic hydrocarbons (PAHs) contained in the aromatic oil is more than 3% by weight, there is a high possibility of causing cancer, and TDAE ( Treated distillate aromatic extract) oil, MES (mild extraction solvate) oil, RAE (residual aromatic extract) oil, or heavy naphthenic oil can be preferably used.

In particular, the oil used as the softener has a total content of PAHs of 3% by weight or less relative to the entire oil, a kinematic viscosity of 95 or more (210°F SUS), an aromatic component in the softener of 15 to 25% by weight, and a naphthenic component. TDAE oil containing 27 to 37% by weight and 38 to 58% by weight of paraffinic component can be preferably used.

The TDAE oil has excellent low-temperature characteristics and fuel efficiency performance of tires containing the TDAE oil, and also has advantageous properties against environmental factors such as the possibility of PAHs causing cancer.

The above vegetable oils include castor oil, cottonseed oil, linseed oil, canola oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, pine tar, tall oil, corn oil, rice bran oil, safflower oil, sesame oil, olive oil, sunflower oil, palm kernel oil, and camellia oil. , jojoba oil, macadamia nut oil, safflower oil, tung oil, and combinations thereof can be used.

The softener is preferably used in an amount of 0 to 10 parts by weight based on 100 parts by weight of the raw rubber in that it improves the processability of the raw rubber.

The anti-aging agent is an additive used to stop the chain reaction in which tires are automatically oxidized by oxygen. The anti-aging agent may be appropriately selected from the group consisting of amine-based, phenol-based, quinoline-based, imidazole-based, carbamate metal salts, waxes, and combinations thereof.

The amine-based anti-aging agent includes N-phenyl-N'-(1,3-dimethyl)-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-N' -Any one selected from the group consisting of cyclohexyl p-phenylenediamine, N-phenyl-N'-octyl-p-phenylenediamine, and combinations thereof may be used. The phenol-based anti-aging agents include phenol-based 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-isobutylidene-bis(4,6-dimethylphenol), 2 , 6-di-t-butyl-p-cresol, and any one selected from the group consisting of combinations thereof can be used. As the quinoline-based anti-aging agent, 2,2,4-trimethyl-1,2-dihydroquinoline and its derivatives can be used, specifically 6-ethoxy-2,2,4-trimethyl-1,2-di. Hydroquinoline, 6-anilino-2,2,4-trimethyl-1,2-dihydroquinoline, 6-dodecyl-2,2,4-trimethyl-1,2-dihydroquinoline, and combinations thereof Any one selected from the group can be used. As the wax, waxy hydrocarbon can be preferably used.

Considering the conditions that the anti-aging agent must have a high solubility in rubber in addition to anti-aging effect, must be low in volatility and inert to rubber, and must not inhibit vulcanization, it must be used in an amount of 1 to 10 parts by weight based on 100 parts by weight of the raw rubber. It may be included by weight.

A typical amount of the antioxidant may be, for example, about 0.1 to about 5 parts by weight, for example, 0.1 to 1.0 parts by weight. Examples of antioxidants include, but are not limited to, diphenyl-p-phenylenediamine and others.

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

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

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

The sidewall 200 is a part that extends from both ends of the tread to form the side of the tire, withstands continuously repeated contraction and expansion during driving, and protects the carcass layer 400 located on the inner side. Do it.

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

A carcass layer 400 is located between a pair of left and right bead portions 300 and is bonded to the tire rubber sheet inside the tire to form the frame of the tire. The carcass layer 400 is connected to the bead core 500. ) It is wrapped around the tire from the inside to the outside.

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

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

The belt layer includes a rubber composition according to an embodiment of the present invention. The internal pressure of the tire is much higher than atmospheric pressure, and as the driving time increases, the temperature reaches a high temperature exceeding 120℃. Therefore, it is important to ensure the safety of the vehicle in such high temperature and high pressure conditions. In particular, steel belts play a significant role in physically supporting and protecting tires against the vehicle load. Therefore, the adhesion between the steel cord and the rubber composition is important.

Even after vulcanization, water molecules that may remain in the rubber matrix or water molecules present in the inner space of the tire diffuse and move through the inner liner, and when the water molecules meet the steel cord of the belt area, the penetrated water molecules act as ligands. It acts to form a bond with the steel cord or cobalt metal, and as a result, -SH, -S- moieties, or double bond portions in the polymer chain that are coordinating with the steel cord or cobalt metal are separated, resulting in a decrease in bonding strength. Brings . Corrosion of the steel cord due to the combination of water molecules and the steel cord is a natural result.

According to one embodiment of the present invention, the hygroscopic monomer contained in the tire belt rubber composition is combined with the raw rubber, and the hygroscopic polymer, when mixed with the raw rubber, binds to water molecules and adsorbs water molecules, thereby absorbing water molecules. It can stop or slow down the movement of.

The tire belt rubber composition may include a cobalt compound.

The cobalt compounds include cobalt salts, cobalt-boron esters, organic acid cobalt salts, inorganic acid cobalt salts, and non-cobalt salts, and as adhesive systems, in addition to cobalt salts alone, cobalt-RH, and cobalt-HRH, resins [e.g. Methylene acceptor: phenol-based, resorcinol-based, cresol-based, etc., or donor: adhesive system modified with hexamethylenetetraamine (HMT), hexamethoxymethylmelamine (HMMA), pentamethoxymethylmelamine (PMMA)] there is.

In general, to improve adhesion, improvement of the adhesive system of adhesive compound rubber (cobalt-RH, cobalt-HRH, their modified system), improvement of resin used as an adhesive aid and improved performance, improvement of cobalt salt used as an adhesive aid, and adhesion Improvements to the rubber vulcanization system and use of new compounding compositions (reinforcers, carbon black, silica, polymers, chemicals) are being used.

The content of the cobalt compound may include 0.2 to 5.0 parts by weight, for example, 0.2 to 2.0 parts by weight, based on 100 parts by weight of raw rubber, but is not limited thereto.

If the content of the cobalt compound is less than 0.2 parts by weight based on 100 parts by weight of the raw rubber, the adhesion effect is minimal, and if it exceeds 5.0 parts by weight, there may be a problem of reduced adhesion.

The tire belt rubber composition can be manufactured through a conventional two-step continuous manufacturing process. That is, during the first step of thermomechanical treatment or kneading at a maximum temperature ranging from 110 to 190° C., preferably at a high temperature of 130 to 180° C. and the finishing step in which the crosslinking system is mixed, typically below 110° C., e.g. It can be prepared in a suitable mixer using a second step of mechanical treatment at a low temperature of 40 to 100°C, but is not limited to this.

A tire belt according to another embodiment of the present invention includes the tire belt rubber composition.

A tire according to another embodiment of the present invention includes using the belt when forming a green tire. The method of manufacturing a tire belt using the tire belt rubber composition and the method of forming a green tire using a permanent belt can be applied to any method conventionally used for manufacturing tires, and is detailed in the specification. The explanation is omitted.

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.

In Figure 1, tires for passenger cars are illustrated, but the tire is not limited thereto, and may be tires for passenger cars, racing tires, airplane tires, tires for agricultural machinery, off-the-road tires, truck tires, or bus tires. there is. Additionally, 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 illustrating the present invention and are not intended to limit the scope of the present invention.

Examples 1 to 3 and Comparative Examples 1 to 3

The compositions shown in Table 1 below were added to a Banbari mixer to mix the rubber compositions of Examples and Comparative Examples.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Comparative Example 3 natural rubber 100 100 100 100 100 100 Carbon Black ¹⁾ 60 60 60 60 60 60 Hygroscopic monomer ²⁾ - 0.3 0.5 0.8 1.1 1.4 Cobalt ³⁾ 1.5 1.5 1.5 1.5 1.5 1.5 sulfur 8.0 8.0 8.0 8.0 8.0 8.0 Accelerator ⁴⁾ 0.5 0.5 0.5 0.5 0.5 0.5

1) Carbon black: N320

2) Acrylic acid

3) Cobalt: COBALT BORO NEODECANOATE

4) Accelerator: N,N-Dicyclohexyl-2-benzothiazolesulfenamide

A steel cord (2+2x0.35 HT) was added to the rubber sheet prepared above and vulcanized in a vulcanizer at 165°C for 16 minutes to produce a specimen.

Evaluation example

The physical properties of the specimens prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated as follows, and the results are shown in Table 2 below.

Measurement of heat resistance adhesion [heat resistance aging]

Measured according to ASTM standards (D2229-04). Heat-resistant adhesion is a value that expresses the adhesion between steel cord and vulcanized rubber at high temperatures. The higher the value, the higher the safety of the tire.

Moist heat adhesion measurement [moist heat aging]

Measured according to ASTM standards (D2229-04). Wet heat adhesion is a value expressing the adhesion between steel cord and vulcanized rubber in a high temperature and humid environment. The higher the value, the higher the safety of the tire.

Tensile properties

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

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Comparative Example 3 Early 50.0(100) 51.0(100) 50.0(100) 49.0(100) 50.5(100) 42.0(95) heat aging 49.0(100) 50.0(100) 48.5(100) 50.0(100) 49.5(100) 41.0(95) wet heat adhesion 42.0(85) 42.0(85) 45.0(90) 45.5(90) 46.0(95) 39.0(85) 50% modulus (kgf/cm ² ) 25 24 25 24 25 27 Tensile strength (kgf/cm ² ) 250 253 252 251 253 225

The values in Table 2 above represent the amount (%) of rubber remaining on the surface of the steel cord after evaluating the pull-out adhesion, and the values in parentheses are indexed based on the initial value of 100, indicating that the heat aging resistance and moist heat aging values are high. The more excellent it is.

From the results in Table 2, it can be seen that the wet heat adhesion of the steel belts topped with the rubber compositions of Examples 1 to 3 was superior to that of Comparative Examples 1 to 3.

Specifically, it can be seen that Comparative Example 2, where the content of the hygroscopic monomer was 0.3 parts by weight, and Comparative Example 3, where the content of the hygroscopic monomer was 1.4 parts by weight, showed lower adhesive strength than Examples 1 to 3. In particular, Comparative Example 3 showed lower initial adhesion and heat-resistant adhesive strength than Examples 1 to 3.

Although the above has been described with reference to the embodiments, those skilled in the art may modify and modify the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims of the present invention. You will understand that you can change it.

10: tires
100: Tread part
200: Side wall part
300: Bead part
400: Carcass layer
500: bead core
600: Belt layer
700: Innerliner
800: Capfly

Claims (9)

raw rubber; filler; and acrylamide; a tire belt rubber composition comprising. delete delete delete delete According to paragraph 1,
A tire belt rubber composition comprising 0.5 to 1.2 parts by weight of acrylamide based on 100 parts by weight of raw rubber. According to paragraph 1,
A tire belt rubber composition, wherein the raw rubber is made of natural rubber. A tire belt comprising the tire belt rubber composition of claim 1. A tire equipped with the tire belt of paragraph 8.

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