KR102332842B1 - Rubber composition for tire sidewall and tire manufactured by using the same - Google Patents

Abstract

The present invention relates to a rubber composition for a tire sidewall comprising a raw rubber, a reinforcing filler, and a polyoctenamer.

Description

A rubber composition for a tire sidewall and a tire manufactured using the same

The present invention is a rubber composition for a tire sidewall comprising raw rubber, a reinforcing filler, and polyoctenamer, and by using recycled carbon black and polyoctenamer, it has excellent low fuel efficiency and low manufacturing cost. It relates to a rubber composition for a sidewall that is inexpensive and has good tire performance.

Recently, as people frequently experience abnormal symptoms such as abnormal climate and ecosystem disturbance due to the influence of global warming, consumers' demand for low-carbon and fuel-efficient vehicles is growing. As a part of this, research to improve the fuel-efficient performance of the rubber constituting the tread and sidewall of the tire is continuing.

However, when one performance of a tire is improved, a so-called 'trade off phenomenon' occurs, in which one or more other performances are lowered. Development of a rubber composition with improved various performances required for driving is not an easy situation.

Specifically, when improving the low fuel consumption performance of the tire, there is a problem in that the handling and braking performance of the tire are deteriorated. Therefore, it is important to prevent deterioration of the handling and braking performance while improving the low fuel consumption performance. In order to solve this problem, the amount of carbon black was reduced or carbon black with a large particle size was used. There is an inappropriate problem with

On the other hand, as the cost of carbon black, which is essentially added to the tire, is improved due to the continuous increase in oil price, there is a problem in that the manufacturing cost of the tire is increased.

In order to solve this problem, by using recycled carbon black obtained by recovering carbon black, a method of reducing the cost of tires by replacing the amount of carbon black used while reducing carbon emission has emerged.

However, when only recycled carbon black is used, there is a problem in that the physical properties of the tire are greatly deteriorated. Therefore, while preventing the deterioration of the physical properties of the tire, the technical research for reducing the manufacturing cost of the tire and improving the low fuel efficiency performance is continued.

An object of the present invention is to provide a rubber composition for a tire sidewall that has good physical properties of a tire while enabling low fuel consumption performance and reduction in manufacturing cost of the tire.

Another object of the present invention is to provide a rubber composition for a tire sidewall having an optimal content in consideration of tire performance and manufacturing cost reduction effect.

Another object of the present invention is to provide a tire prepared from the rubber composition for a tire.

The present invention provides a rubber composition for a tire sidewall comprising a raw rubber, a reinforcing filler, and a polyoctenamer.

In one embodiment of the present invention, the reinforcing filler may include carbon black and recycled carbon black.

In one embodiment of the present invention, the rubber composition for a tire may include 100 parts by weight of the raw rubber, 20 to 70 parts by weight of the reinforcing filler, and 1 to 10 parts by weight of the polyoctenamer.

In an embodiment of the present invention, the polyoctenamer may have a cis/trans ratio of 15:85 to 25:75.

In one embodiment of the present invention, the polyoctenamer may have a glass transition temperature of -75 to -55 ℃.

In one embodiment of the present invention, the raw rubber may include natural rubber and butadiene rubber in a weight ratio of 2:8 to 8:2.

In one embodiment of the present invention, the reinforcing filler may include carbon black and recycled carbon black.

In one embodiment of the present invention, the rubber composition for tires may further include at least one selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a softener, a processing oil, and an anti-aging agent.

The present invention also provides a tire manufactured from the rubber composition for a tire sidewall of the present invention.

According to the present invention, when a tire is manufactured using the same, the tire has excellent fuel-efficiency performance and reduced manufacturing cost.

In the present invention, when a tire is manufactured using the same, the tire has excellent physical properties while excellent in fuel-efficient performance.

Another object of the present invention is to provide a tire prepared from the rubber composition for a tire.

Hereinafter, each configuration of the present invention will be described in more detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents not limited.

The rubber composition for a tire sidewall according to the present invention includes a raw rubber, a reinforcing filler, and a polyoctenamer.

In particular, as the reinforcing filler, carbon black and recovered carbon black (rCB) may be included.

Specifically, the carbon black uses a carbon black having an iodine adsorption amount of 30 to 41 mg/g and an DBP (dibutylphthalate) oil absorption of 85 to 97 cc/100 g, and the regenerated carbon black is recycled by processing waste tires, etc. As the carbon black obtained by water purification, the use of crude oil is reduced by re-using the used carbon black, and the raw material price is low, so that the manufacturing cost of the tire can be reduced.

However, in the present invention, the reinforcing filler does not use only recycled carbon black, but uses a mixture of carbon black and recycled carbon black, and uses the carbon black and the recycled carbon black in a weight ratio of 1: 0.1 to 0.5. Mix and use. Preferably, it is mixed and used in a weight ratio of 1: 0.12 to 0.3. This is because, when only recycled carbon black is used, it is difficult to maintain low fuel efficiency and there is a problem in that the physical properties of the manufactured tire are greatly deteriorated.

Therefore, when a small amount of recycled carbon black is added than the above ratio, there is a problem that the cost saving effect is insufficient compared to the physical properties. there is

In the rubber composition for a tire sidewall according to the present invention, the reinforcing filler may be added in an amount of 20 to 70 parts by weight based on 100 parts by weight of the raw rubber. Preferably, it may be added in an amount of 30 to 60 parts by weight, and when it is added in a smaller amount than the above content, handling performance and fatigue performance are reduced due to low hardness and modulus, and there is a problem in that workability is lowered, and the content is excessive There is a problem in that the rotational resistance performance is reduced when it is added.

On the other hand, when a reinforcing filler is added to the rubber composition, the fuel-efficient performance manufactured using the same is improved, but there is a problem in that handling and braking performance during vehicle driving are reduced. It is characterized in that it contains a mer (Polyoctenamer).

Specifically, the polyoctenamer included in the rubber composition for a tire sidewall of the present invention is 1,8-trans-polyoctenamer rubber [CAS No. 28730-09-8], which is also called trans-polyoctenylene.

It is obtained from cyclooctene through ring-opening metathesis polymerization (ROMP), and is a material containing both linear and cyclic macromolecules.

In the present invention, the polyoctenamer may have a cis/trans ratio of 15:85 to 25:75. Preferably, it may be 17:83 to 27:73, and most preferably, it may be 20:80. More specifically, the polyoctenamer may have a glass transition temperature (T _g ) of -75 to -55°C, and most preferably, -65°C. The polyoctenamer may have a weight average molecular weight of 80,000 to 100,000 Mw (g/mol).

Polyoctenamer suitable for the present invention satisfying the above conditions may be, for example, Vestenamer® 8012 manufactured by Evonik of Germany. However, it is not limited thereto, and all compounds identical or similar thereto can be used.

In the present invention, the polyoctenamer may be added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the raw rubber, preferably, 2 to 8 parts by weight, most preferably, 3 to 5 parts by weight. have.

When added in a small amount than the above content, the effect of preventing deterioration of tire properties is not great, and when added in an excess of the above content, there is a problem in that the effect of reducing tire manufacturing cost is not large.

In the rubber composition for a tire sidewall according to the present invention, the raw rubber may include natural rubber and butadiene rubber (BR), and natural rubber and butadiene rubber are mixed in a ratio of 2:8 to 8:2. may be included in a weight ratio of Preferably, it may be included in a weight ratio of 2.8:7.2 to 7.7:2.8.

When the natural rubber is added in a small amount than the above ratio, there is a problem in that low fuel consumption performance and workability are lowered.

As the natural rubber, both general natural rubber and modified natural rubber may be used. Although it mainly contains cis-1,4-polyisoprene, it is not necessarily limited thereto, and natural rubber containing trans-1,4-polyisoprene may also be used.

The butadiene rubber is a homopolymer of 1,3-butadiene, and is also called polybutadiene rubber. The butadiene rubber has a cis-1,4-bond, a trans-1,4-bond, and a vinyl1 bond, but the type or ratio thereof is not particularly limited and can be used.

The rubber composition for a tire sidewall according to the present invention may further include at least one selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a softener, a processing oil, and an anti-aging agent. This is an additive used in the manufacture of the rubber composition for tires, and may be appropriately added as necessary.

Any of the additives may be used as long as they are commonly used in the art to which the present invention pertains, and the content thereof may be added according to the compounding ratio used in the art.

The vulcanizing agent may include a sulfur-based vulcanizing agent, an organic peroxide, a resin vulcanizing agent, a metal oxide, and the like.

Specifically, the sulfur-based vulcanizing agent is an inorganic vulcanizing agent such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloidal sulfur, and tetramethylthiuram disulfide (Tetramethylthiuram disulfide, TMTD) , tetraethyltriuram disulfide (TETD), an organic curing agent such as dithiodimorpholine (Dithiodimorpholine) can be used.

It is preferable that the vulcanizing agent is included in an amount of 0.5 to 2.5 parts by weight based on 100 parts by weight of the raw rubber in terms of making the raw rubber less sensitive to heat and chemically stable as an appropriate vulcanizing effect.

The organic peroxide is benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, t-butylcumylperoxide, methylethyl Ketone peroxide (Methylethylketone peroxide), cumene hydroperoxide (Cumene hydroperoxide), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (2,5-dimethyl-2,5-di (t) -butylperoxy)hexane), 2,5-dimethyl-2,5-di(benzoylperoxy)hexane (2,5-dimethyl-2,5-di(benzoylperox)hexane), 1,3-bis(t-butyl Peroxypropyl)benzene (1,3-bis(t-butylperoxypropyl)benzene), di-t-butylperoxy-diisopropyl benzene (Di-t-butylperoxy-diisopropyl benzene), t-butylperoxybenzene (t -butylperoxy benzene), 2,4-dichlorobenzoyl peroxide (2,4-dichlorobenzoyl peroxide), 1,1-dibutylperoxy-3,3,5-trimethylsiloxane (1,1-dibutylperoxy-3,3, 5-trimethylsiloxane), n-butyl-4,4-di-t-butylperoxyvalate (4,4-di-t-butylperoxyvalate), and any one selected from the group consisting of combinations thereof may be used.

The resin vulcanizing agent may be an alkyl phenol resin or the like, and in addition to this, as long as it is used in the relevant technical field, it is not particularly limited and can be used if necessary.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or delay action in the initial vulcanization step, and in order to maximize productivity and rubber properties through acceleration of vulcanization rate, 100 parts by weight of the raw rubber. It may be included in 0.5 to 5 parts by weight.

Examples of the vulcanization accelerator 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 their Any one selected from the group consisting of combinations may be used.

Each compound may be used without particular limitation as long as it is generally used in the relevant technical field, and components used for preparing the rubber composition for tires may be appropriately added as needed.

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

Any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate (ZnCO ₃ ), magnesium oxide (MgO), lead oxide (PbO), potassium hydroxide (KOH) and combinations thereof may be used as the inorganic vulcanization accelerator. can The organic-based vulcanization accelerator includes stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, Any one selected from the group consisting of dibutyl ammonium oleate, derivatives thereof, and combinations thereof may be used.

In order to serve as an appropriate vulcanization accelerator, the vulcanization accelerator may be included in an amount of 1.5 to 8 parts by weight based on 100 parts by weight of the raw rubber, and when the zinc oxide and the stearic acid are used together, 1 to 5 parts by weight of the zinc oxide and 0.5 to 3 parts by weight of the stearic acid.

The rubber composition for a tire sidewall according to the present invention does not need to include a softener because of its excellent processability, but a softener may be further added if necessary.

The softener is an additive added to reduce the hardness of the vulcanized rubber in order to facilitate processing by imparting plasticity to the rubber, and any one selected from the group consisting of process oil, vegetable oil, and combinations thereof. It can be used, but as long as it is used in the relevant technical field, it is not particularly limited and can be used.

As the processing oil, any one selected from the group consisting of paraffin-based processing oil, naphthenic processing oil, aromatic processing oil, and combinations thereof may be used.

However, when the content of polycyclic aromatic hydrocarbons (PAHs) contained in the aromatic process oil is 3% by weight or more, along with the recent increase in environmental awareness, it is known that the cancer-causing potential is high, and used as the softener The processed oil has a total content of PAHs of 3% by weight or less with respect to the entire processing oil, a kinematic viscosity of 95°C or higher (210°F SUS), 15 to 25% by weight of aromatic components in the softener, and 27 to naphthenic components It is preferable to use 37 wt% and 38 to 58 wt% of the paraffinic component.

When the rubber composition for a tire sidewall according to the present invention includes the processing oil, the low-temperature characteristics and fuel efficiency of the tire sidewall manufactured using the rubber composition are improved, and advantageous characteristics against environmental factors such as the possibility of cancer inducing PAHs has

The 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, camellia oil , jojoba oil, macadamia nut oil, safflower oil, tung oil, and any one selected from the group consisting of combinations thereof may be used.

The softener may be included in an amount of 0 to 50 parts by weight, or 20 to 40 parts by weight, based on 100 parts by weight of the raw rubber in order to improve the processability of the raw rubber.

The antioxidant is an additive used to stop the chain reaction in which the tire is automatically oxidized by oxygen. As the antioxidant, any one selected from the group consisting of amine-based, phenol-based, imidazole-based, carbamic acid metal salts and combinations thereof may be added.

The antioxidant includes N-(1,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (N-(1,3-Dimethylbutyl)-N-phenyl-p-phenylenediamine, 6PPD), N-phenyl -n-isopropyl-p-phenylenediamine (N-phenyl-n-isopropyl-p-phenylenediamine, 3PPD) and poly (2,2,4-trimethyl-1,2-dihydroquinoline (Poly (2,2) ,4-trimethyl-1,2-dihydroquinoline, RD) and a compound selected from the group consisting of combinations thereof may be preferably used.

In consideration of the conditions such as that the antioxidant should have high solubility in rubber, low volatility, inert to rubber, and not inhibit vulcanization, in addition to the anti-aging action, 0 based on 100 parts by weight of the raw rubber to 10 parts by weight.

The present invention also provides a tire manufactured using the above-described rubber composition for a tire sidewall.

The tire may be a passenger car tire, a racing tire, an airplane tire, an agricultural machine tire, an off-the-road tire, a truck tire, or a bus tire. Also, the tire may be a radial tire or a bias tire.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents not limited.

[Production Example: Preparation of rubber composition for tire sidewall]

Rubber compositions according to Examples and Comparative Examples were prepared with the composition shown in Table 1 below. The rubber composition was prepared according to a conventional tire manufacturing method.

(Unit: phr) comparative example Example One 2 3 4 5 One 2 3 4 natural rubber 60 60 60 60 60 60 60 60 60 butadiene rubber 40 40 40 40 40 40 40 40 40 carbon black 30 30 30 30 30 30 30 30 30 Recycled Carbon Black - - - 5 10 5 5 5 10 Vestenamer - 3 5 - - One 3 5 3 zinc oxide 3 3 3 3 3 3 3 3 3 stearic acid 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 anti-aging agent 5 5 5 5 5 5 5 5 5 process oil 12 12 12 12 12 12 12 12 12 brimstone 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 vulcanization accelerator 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5

[Experimental Example: Measurement of physical properties of rubber composition]

For the rubber specimens of Examples and Comparative Examples prepared according to Preparation Example, physical properties were measured in the following manner, and the results are shown in Table 2.

(1) Mooney Viscosity (ML(1+4), 125℃): Large Rotor using Mooney MV2000 (Alpha Technology Co.) device, preheated for 1 minute, then operated for 4 minutes. did.

(2) Tensile test: The hardness was measured using a Shore A durometer, and the tensile test was measured using an Instron tester according to the ASTM D412 test method.

(3) Viscoelasticity test: Using a DMTS (Dynamic Material Testing System) tester, it was measured while performing a temperature sweep from -60°C to 80°C under the conditions of 10Hz, 5% static strain, and 0.5% dynamic strain.

(4) Price: It was calculated considering the raw material price and phr at the present time, and the higher the Index value, the higher the price.

comparative example Example One 2 3 4 5 One 2 3 4 Mooney viscosity
(Unit: MU) 41.2 40 38.5 42.3 44.5 42.1 39.1 39 42.7 Hardness 50 50 49 51 51 51 51 50 51 300% modulus 59 56 53 62 64 62 63 66 66 Elongation (%) 569 580 593 555 530 542 539 557 544 60℃ tanδ 0.068 0.097 0.078 0.083 0.093 0.081 0.061 0.058 0.081 Price (Index) 100 104 107 95 92 96 99 102 98

Mooney viscosity is a value indicating the viscosity of unvulcanized rubber, and the lower the numerical value, the better the processability of the unvulcanized rubber. The hardness indicates steering stability, and the higher the number, the better the steering stability performance. As for the 300% modulus and elongation, the higher the numerical value, the better the tensile properties.

60℃ tanδ represents the rolling resistance characteristics, and the lower the value, the better the fuel economy performance. For price, the higher the index value, the higher the raw material cost.

Referring to Tables 1 and 2, it can be seen that Examples 1 to 3 have better processability than Comparative Example 4 in which the same amount of recycled carbon black is added, and Example 4 has better processability than Comparative Example 5. As a result, it can be seen that the processability of rubber is improved when polyoctenamer is added.

On the other hand, in Comparative Example 3, in which only polyoctenamer was added in excess, it was confirmed that the hardness was lower than that of other specimens. It can be seen that there is a slight drop.

As for the 300% modulus and elongation, Example 4 had higher values than Comparative Example 5, confirming that the tensile properties were excellent. In Examples 1 to 3, the modulus value was measured to be higher than that of Comparative Examples, and the elongation was somewhat lowered, but this was at a good level compared to Comparative Example 1 in which only carbon black was added. It can be seen that when tenamer is used together, the physical properties of the tire are not deteriorated.

The 60°C tanδ was measured to be generally lower than that of the comparative examples in the Examples, and it can be confirmed that all of them have excellent rotational resistance characteristics and excellent low fuel efficiency. In particular, it was confirmed to be excellent in Examples 2 and 3.

In terms of price, Comparative Examples 4 and 5, in which only recycled carbon black was added without adding polyoctenamer, showed the lowest manufacturing cost, but as described above, when only recycled carbon black is added, rubber processability, It was confirmed that there was a problem that the tensile properties and the rolling resistance properties were greatly deteriorated, so that it was not suitable for use in tires.

Claims (5)

Including raw rubber, reinforcing filler and polyoctenamer (Polyoctenamer),
wherein the reinforcing filler comprises carbon black and recycled carbon black;
Based on 100 parts by weight of the raw rubber, 20 to 70 parts by weight of the reinforcing filler and 3 to 5 parts by weight of the polyoctenamer are included,
The raw rubber contains natural rubber and butadiene rubber in a weight ratio of 2:8 to 8:2,
The rubber composition for a tire sidewall comprising the carbon black and the regenerated carbon black in a weight ratio of 1: 0.1 to 0.50. According to claim 1,
The rubber composition for a tire sidewall, characterized in that the polyoctenamer has a cis/trans ratio of 15:85 to 25:75. According to claim 1,
The rubber composition for a tire sidewall, characterized in that the polyoctenamer has a glass transition temperature of -75 to -55°C. According to claim 1,
The rubber composition for a tire sidewall further comprises at least one selected from the group consisting of a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a softener, a processing oil, and an anti-aging agent. A tire manufactured from the rubber composition for a tire sidewall according to claim 1.