KR20240036420A - Rubber for tire tread and tire comprising the same - Google Patents

Abstract

The present invention discloses rubber for tire treads and tires including the same.
The rubber for tire tread and the tire containing the same according to the present invention are a rubber composition containing raw rubber, a reinforcing agent, and additives, and the reinforcing agent has the characteristic of containing hydrophobically modified wood powder. Accordingly, the conventional rubber composition for tire tread is Compared to others, it is more environmentally friendly and can be effective in improving braking power on snow, ice, or rainy roads.

Description

Rubber for tire tread and tire including the same {Rubber for tire tread and tire comprising the same}

The present invention relates to rubber for tire treads and tires containing the same, and more specifically, to rubber for tire treads and tires containing the same, which are environmentally friendly compared to conventional rubber compositions for tire treads and can improve braking power on snow, ice, or rainy roads. It's about.

In general, tire rubber compositions are manufactured based on rubber as a raw material and using fillers such as carbon and silica for the purpose of reinforcing effect and reducing costs by increasing volume.

When these tires are in use, they pollute the air environment due to particles caused by wear of the tread portion while driving, and if they flow into the water system, they can also cause water pollution.

In addition, there is a problem that it causes environmental problems because it is not decomposable at all when discarded after use.

To solve this problem, technologies using eco-friendly materials such as starch, cellulose, protein, and wood flour have recently been researched, but the miscibility between hydrophilic eco-friendly materials and hydrophobic rubber is poor, which significantly reduces tire durability and performance. Because of this, commercialization is difficult.

Meanwhile, in terms of tire performance, in areas where it rains frequently or high latitudes where there is a lot of snow, such as Europe, the performance of tires on wet roads is considered important.

These tires have poor performance on wet roads due to the formation of a water film during driving due to the hydrophobic nature of the rubber material.

In order to minimize these vulnerabilities, hydrophilic fillers such as silica are used to improve tire performance on wet roads. However, since silica is also an inorganic material, it does not help the decomposability of tires when discarded after use, which still causes environmental problems. There is.

Republic of Korea Patent Registration No. 705785B (registration date: April 10, 2007)

The technical problem to be solved by the present invention is to provide a tire tread rubber and a tire containing the same that are environmentally friendly and can improve braking power on snow, ice, or rainy roads compared to conventional rubber compositions for tire treads.

In order to solve the above-mentioned technical problems, the present invention provides a rubber for tire treads, wherein the rubber composition includes raw rubber, a reinforcing agent, and an additive, and the reinforcing agent includes hydrophobically modified wood powder.

According to another embodiment of the present invention, the wood flour may be modified with a polyolefin-based resin that combines with hydroxyl groups.

Meanwhile, the present invention provides a tire characterized by being manufactured from the above-described tire tread rubber.

According to the tire tread rubber and the tire containing the same according to the present invention, compared to the conventional tire tread rubber composition, it is environmentally friendly and has the effect of improving braking power on snow, ice, or rainy roads.

Hereinafter, the present invention will be described in detail.

However, it should be noted that the technical terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention.

In addition, the technical terms used in the present invention, unless specifically defined in a different sense in the present invention, should be interpreted as meanings generally understood by those skilled in the art in the technical field to which the present invention pertains, and are not overly comprehensive. It should not be construed in a literal or excessively reduced sense, and if the technical term used in the present invention is an incorrect technical term that does not accurately express the idea of the present invention, it should be used as a technical term that can be correctly understood by a person skilled in the art. It should be understood as a replacement, and general terms used in the present invention should be interpreted as defined in the dictionary or according to the context, and should not be interpreted in an excessively reduced sense, and the singular terms used in the present invention The expression includes plural expressions unless the context clearly indicates otherwise, and in the present invention, terms such as 'consists' or 'comprises' necessarily include all of the various components or steps described in the invention. It should not be construed that some of the components or steps may not be included, or that additional components or steps may be included, and in describing the present invention, related known technologies should be used. If it is determined that a detailed description may obscure the gist of the present invention, the detailed description will be omitted.

The tire tread rubber and the tire containing the same according to the present invention are a rubber composition containing raw rubber, a reinforcing agent, and an additive, and the reinforcing agent has the characteristic of containing hydrophobically modified wood powder.

The raw rubber can be used as natural rubber or synthetic rubber, and the synthetic rubber is not particularly limited, but the synthetic rubber includes styrene butadiene rubber (SBR), modified styrene butadiene rubber, butadiene rubber (BR), and modified butadiene rubber. At least one selected from the group of rubbers may be used.

In addition, the reinforcing agent is used as a filler, and carbon, carbon black, silica, etc. can be used for the purpose of reinforcing effect and cost reduction by increasing volume.

In addition, the above additives are used by mixing with rubber to demonstrate various functions or characteristics of tire rubber, and include process oil, dispersant, zinc oxide, stearic acid, wax, anti-aging agent, vulcanizing agent, vulcanization retardant, vulcanization accelerator, and vulcanizing agent. It may include the like.

On the other hand, by using the wood powder modified to be hydrophobic, it is possible to solve the problem of significantly reducing tire durability and various performance due to low miscibility with hydrophobic rubber due to the wood powder being hydrophilic.

Therefore, it may be modified with a polyolefin resin that binds to the hydroxyl group in the wood flour.

Such polyolefin-based resins include polyalkene resins, for example, polymers of alkenes such as ethylene, propylene, butene, and pentene, and copolymers thereof grafted with maleic anhydride. For example, polyalkene resins are grafted with maleic anhydride. Propylene, polyethylene grafted with maleic anhydride, polybutene grafted with maleic anhydride, and polypentene grafted with maleic anhydride can be used.

In addition, 5 to 15 parts by weight of surface-modified wood powder can be used for 100 parts by weight of the raw rubber. If this range is exceeded, difficulties may arise in improving braking power on snow, ice or wet roads. If the amount is less than 5 parts by weight, the development of hydrophilicity on the tire surface is minimal, so it is difficult to expect improvement in hydroplaning, and on the other hand, if it exceeds 15 parts by weight, the rubber properties of the tire may decrease significantly, reducing braking power.

On the other hand, the wood flour can be filtered through a 120 to 300 mesh before modification, and is pretreated with a solvent such as acetic acid to remove complex matrices such as lignin, dried, and then prepared as a polypropylene solution grafted with maleic anhydride. It can be obtained by impregnating all or part of the surface with modification.

If the mesh is less than 120 mesh, hydrophilicity on the tire surface is minimal, so it is difficult to expect improvement in hydroplaning. Conversely, if it exceeds 300 mesh, the rubber properties of the tire may decrease significantly, reducing braking power.

On the other hand, after drying the wood flour modified with the polymer resin, the surface of the wood flour can be coated with a non-polar polymer by acetylene low-temperature plasma treatment. This occurs when a polymerization reaction of acetylene monomers activated with Plusma occurs and the wood flour is wrapped in a non-polar thin polymer film. The bonding strength between the grafted polymer and wood flour can be further improved and the non-polar nature of the surface can be increased to further increase the bonding strength with rubber.

In addition, this can improve the significant decline in mechanical properties (modulus) caused by weak bonding with rubber, which was the biggest problem when using wood powder in existing rubber, and the hydrophilic properties of wood powder exposed due to wear on the tire surface prevent snow, While reducing hydroplaning on icy and rainy roads, it is possible to maintain braking characteristics without sacrificing much of the mechanical properties, resulting in improved braking power on snow, icy and rainy roads.

On the other hand, a tread rubber semi-finished product is manufactured from the above-mentioned tread rubber, and a secondary case is prepared by laminating the tread rubber semi-finished product like a belt on the primary case in which semi-finished products such as inner liner and carcass ply are laminated on a molded drum, and then vulcanized. Thus, tires can be manufactured.

Examples of possible implementations of the present invention are described below, but these are merely illustrative, and those skilled in the art will be able to make various modifications and other equivalent embodiments therefrom. You will understand.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the attached patent claims.

<Example 1>

For 100 parts by weight of raw rubber consisting of 50 parts by weight of natural rubber and 50 parts by weight of styrene butadiene rubber, 45 parts by weight of carbon black, 45 parts by weight of silica, 35 parts by weight of process oil, 5 parts by weight of surface-modified wood flour (120 mesh), 3 parts by weight of hexamethyldisilazane (HMDZ) as a silica dispersant, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, 1.5 parts by weight of wax, and N-(1) as an anti-aging agent. ,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine was added to 2 parts by weight and mixed in a Banbury mixer to obtain a rubber compound. Next, 2 parts by weight of sulfur as a vulcanizing agent, 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanization accelerator, and 0.2 part by weight of a vulcanization retardant (PVI) were added to the above rubber mixture in a Banbury mixer. and mixed to obtain the final rubber mixture. To test this, rubber specimens were prepared by vulcanizing at 160°C for 20±5 minutes. Here, the wood flour was filtered through a 120 mesh before modification, pretreated with a solvent such as acetic acid to remove complex matrices such as lignin, dried at 110°C for 1 hour to remove moisture, and made into a polypropylene solution grafted with maleic anhydride. A product in which all or part of the surface was modified by impregnation was used.

<Example 2>

A rubber specimen was manufactured in the same manner as in Example 1, except that 10 parts by weight of surface-modified wood flour (120 mesh) was used instead of 5 parts by weight.

<Example 3>

A rubber specimen was manufactured in the same manner as in Example 1, except that 15 parts by weight of surface-modified wood flour (120 mesh) was used instead of 5 parts by weight.

<Example 4>

For 100 parts by weight of raw rubber consisting of 50 parts by weight of natural rubber and 50 parts by weight of styrene butadiene rubber, 45 parts by weight of carbon black, 45 parts by weight of silica, 35 parts by weight of process oil, 5 parts by weight of surface-modified wood flour (120 mesh), 3 parts by weight of hexamethyldisilazane (HMDZ) as a silica dispersant, 3 parts by weight of zinc oxide (ZnO), 2 parts by weight of stearic acid, 1.5 parts by weight of wax, and N-(1) as an anti-aging agent. ,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine was added to 2 parts by weight and mixed in a Banbury mixer to obtain a rubber compound. Next, 2 parts by weight of sulfur as a vulcanizing agent, 1 part by weight of N-cyclohexyl-2-benzothiazole-sulfenamide (CZ) as a vulcanization accelerator, and 0.2 parts by weight of a vulcanization retardant (PVI) were added to the above rubber mixture in a Banbury mixer. and mixed to obtain the final rubber mixture. To test this, rubber specimens were prepared by vulcanizing at 160°C for 20±5 minutes. Here, the wood flour was filtered through a 120 mesh before modification, pretreated with a solvent such as acetic acid to remove complex matrices such as lignin, dried at 110°C for 1 hour to remove moisture, and made into a polypropylene solution grafted with maleic anhydride. Modify all or part of the surface by impregnating it, remove moisture by drying at 110°C for 1 hour, and then lower the internal pressure of the reactor to below 0.01 Torr at room temperature using radio frequency plasma in an acetylene atmosphere. The gas was fixed to flow at a flow rate of 0.5 SCCM, the electrodes of the reactor were connected to the power supply, the voltage was raised, and when plasma was formed, it was set to 10W and treated for 10 minutes.

<Comparative Example 1>

A rubber specimen was prepared in the same manner as in Example 1, except that 5 parts by weight of surface-modified wood flour (120 mesh) was not added.

<Comparative Example 2>

A rubber specimen was manufactured in the same manner as in Example 2, except that 10 parts by weight of regular wood flour (120 mesh) before surface modification was used instead of 10 parts by weight of surface-modified wood flour (120 mesh).

<Comparative Example 3>

A rubber specimen was manufactured in the same manner as Example 1, except that 3 parts by weight of surface-modified wood flour (120 mesh) was used instead of 5 parts by weight.

<Comparative Example 4>

A rubber specimen was manufactured in the same manner as in Example 1, except that 17 parts by weight of surface-modified wood flour (120 mesh) was used instead of 5 parts by weight.

<Test example>

Tensile properties such as hardness, 300% modulus, tensile strength (T.S.), and elongation balance (E.B.) were measured for the rubber specimens prepared in the above examples and comparative examples. Measurements were made according to ASTM related regulations, and the results and the rubber manufactured in Examples 1 to 3 and Comparative Examples were used as tire tread rubber, and for each tire, water, snow, and ice ( The braking force on wet roads such as ice was measured, and the results are shown in <Table 1> below.

division Comparative Example 1 Comparative example 2 Comparative Example 3 Comparative example 4 Example 1 Example 2 Example 3 Example 4 raw rubber 100 100 100 100 100 100 100 100 Wood flour before modification 0 0 3 17 5 10 15 0 Wood flour after reforming 0 10 0 0 0 0 0 0 plasma
Treated wood flour 0 0 0 0 0 0 0 15 Hardness 100 95 100 95 101 100 99 99 Modulus (300%) 100 70 98 70 98 95 90 95 elongation 100 70 98 70 97 94 90 95 Braking power (water) 100 92 100 93 103 109 111 115 Braking power (snow) 100 95 100 95 103 109 111 115 Braking power (ice) 100 93 100 94 102 106 108 112

In Table 1 above, the tensile properties, braking force, etc. of the examples are converted values based on the tensile properties and braking force of Comparative Example 1 based on 100, and the higher the value, the better the characteristics.

Compared to the rubber of Comparative Example 1, the rubber of the examples according to the present invention shows no significant decrease in tensile properties in Examples 1 to 3, but is suitable for use on watery road surfaces, snow, and ice ( It can be seen that the braking power is excellent on wet roads such as ice.

In addition, when compared to the rubber of Comparative Example 2 using wood powder without surface modification, it can be seen that Example 2 is superior in both tensile properties and braking force.

In addition, in Comparative Example 3 using less than 5 parts by weight, it is difficult to expect improvement in braking performance on roads where water films occur due to the minimal hydrophilicity on the tire surface, and in Comparative Example 4 using more than 15 parts by weight, the rubber properties decreased and performance was not improved. It's hard to expect.

Looking at Example 4, the modulus and elongation were increased compared to Example 3 before plasma treatment, and the bonding strength between the grafted polymer and wood flour was improved due to the plasma-treated wood powder, thereby increasing the bonding strength with the compound rubber and mechanical properties. (Modulus) has been improved, and it can be seen that braking power on snow, ice, and rain can be improved.

Claims (3)

In rubber containing raw rubber, reinforcing agents and additives,
Rubber for a tire tread, wherein the reinforcing agent includes hydrophobically modified wood flour.
According to claim 1,
Rubber for tire tread, characterized in that the wood flour is modified with a polyolefin resin that combines with hydroxyl groups.
A tire manufactured from the tire tread rubber of claim 1 or 2.