JP3382322B2 - Vehicle tires - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to tires for agricultural and construction vehicles. More specifically, the present invention relates to a vehicle tire in which mud is prevented from adhering when traveling in a muddy area including a caking soil or a field area such as a wetland.

[0002]

2. Description of the Related Art When an agricultural vehicle crosses or runs on a paved road, it scatters the mud adhered to the tires of the vehicle on the paved road in a muddy area or in a wetland to protect the road surface. It often gets dirty. Also, if mud from a field contaminated with a pathogen is moved to a field that is not contaminated with a pathogen while adhering to a tire, agricultural crops not contaminated with a pathogen may be contaminated, which may increase damage due to the transmission of the pathogen. is there. Thus, if the mud is clogged between the lug grooves of the agricultural tire or adheres to the tire tread surface, it causes the various problems described above, and this tendency is particularly remarkable in the soft regions and wetlands.

In order to solve such a problem, it is possible to improve the tread pattern of the tire. For example, it is possible to improve the mud handling property by enlarging the lug groove. However, changing the tread pattern such as enlarging the lug groove makes vehicle traction in muddy ground,
Also, the wear life of the tire is shortened. On the other hand, since the adhesion between the rubber used in the tread portion of the tire (hereinafter simply referred to as "tread rubber") and mud occurs through the water contained in the mud, the affinity of the tire tread rubber for water is increased. It is possible to improve the mud-removing property. For example, a vehicle tire in which a silicone rubber sheet having excellent water repellency and non-adhesiveness is attached to the tread surface has been proposed. However, silicone rubber has problems that it is inferior in mechanical strength, particularly tensile strength, has lower abrasion resistance than black rubber, and that diene rubber and silicone rubber cannot be co-vulcanized.

It is also conceivable to use a rubber composition obtained by blending a silicone rubber and a diene rubber as the tread rubber, but since the silicone rubber and the diene rubber have poor compatibility, a tread rubber having high strength is obtained. I can't. Furthermore, since silicone rubber is more expensive than diene rubber, use of silicone rubber leads to an increase in the price of vehicle tires. The present invention has been made in view of the above circumstances, and its purpose is to reduce the affinity for water without reducing wear resistance, mechanical strength, etc. Another object of the present invention is to provide a vehicle tire that is provided with excellent mud resistance.

[0005]

A vehicle tire according to the present invention has a diene rubber component containing general formula Y-Si (OR) ₃ (where Y
Represents C ₆ H ₅ −, CH ₃ C ₆ H ₄ −, CF ₃ C ₂ H ₄ −, NCC ₃ H ₆ −, where
R represents CH ₃ — or C ₂ H ₅ —) is a vehicle tire using a rubber composition containing an organic silane represented by the formula and a reinforcing agent as a tread rubber, wherein the content of the organic silane is the reinforcing agent content of Ri <br/> Ah in an amount of 5 to 15 wt% of the carbon in terms of content in terms of carbon black, is and the reinforcing agent, carbon black and silica
Or clay vehicle tire, wherein the mixture der Rukoto consisting only of at least one.

[0006] The amount of pre Kiho strong agent comprising 35 to 65 parts by weight of carbon in terms of content per 100 parts by weight of the rubber component, the content of carbon black relative to 100 parts by weight of the rubber component B, and the content of silica S, clay content is C
It is preferable that the following formula B ≧ (S / 1.2) + (C / 1.4) is satisfied. Also, the rubber component 100
The content of organosilane per part by weight is 2.5 to 7.5.
It is preferable to use parts by weight.

[0007]

EXAMPLES The rubber used for the tread surface of the vehicle tire of the present invention, that is, the rubber component constituting the tread rubber, is a diene rubber normally used for tread rubber,
For example, natural rubber, BR, SBR or the like is used. As the reinforcing agent to be added to the rubber composition according to the present invention, in addition to carbon black alone, a mixture of carbon black and silica, a mixture of carbon black and clay, or a mixture of carbon black, silica and clay may be used. it can.

The content of the reinforcing agent in the rubber composition is 3 as the content converted to carbon black per 100 parts by weight of the rubber component (hereinafter referred to as "carbon equivalent content").
5 to 65 parts by weight is preferable. Here, the content in terms of carbon means the amount converted into the amount of carbon black capable of exerting a reinforcing effect equivalent to the reinforcing effect of silica or clay when silica or clay is compounded. The reinforcing effect of silica is about the same as carbon black of 1 / 1.2 times the actual blending amount, and the reinforcing effect of clay is the same as carbon black of 1 / 1.4 times the actual blending amount. It is a degree. Therefore, the carbon conversion content of the reinforcing agent content (W _B) can be obtained by the following equation.

W _B = B + (S / 1.2) + (C / 1.4) In the formula, B represents the compounding amount of carbon black, S represents the compounding amount of silica, and C represents the compounding amount of clay. You As part of the reinforcement material, the use of silica or clay, the water repellency of the tread rubber can be further improved. On the other hand, wear resistance,
From the viewpoint of preventing a reduction in tear resistance, the balance between the amount of silica or clay and the amount of carbon black in the entire reinforcing agent is preferably selected so as to satisfy the formula.

B ≧ (S / 1.2) + (C / 1.4) ... The organic silane used in the present invention is represented by the general formula Y—Si (OR)
₃ (wherein Y represents C ₆ H ₅ −, CH ₃ C ₆ H ₄ −, CF ₃ C ₂ H ₄ −, NCC ₃ H ₆ −, and R represents CH ₃ −, C ₂ H ₅ −) Is a compound represented by. Specifically, phenyltrimethoxysilane (C ₆ H ₅
Si (OCH _{3) 3),} phenyltriethoxysilane _{(C 6 H 5 Si (OC} 2
H _{5) 3),} tolyl trimethoxysilane _{(CH 3 C 6 H 4 Si} (OCH 3)
_3), tolyl triethoxysilane _{(CH 3 C 6 H 4 Si} (OC 2 H 5) 3)
, 1,1 difluoropropyltrimethoxysilane (CF ₃ C ₂ H
₄ Si (OCH ₃ ) ₃ ), 1,1 difluoropropyltriethoxysilane (CF ₃ C ₂ H ₄ Si (OC ₂ H ₅ ) ₃ ), cyanopropyltrimethoxysilane (NCC ₃ H ₆ Si (OCH ₃ ) ₃ ) And cyanopropyltriethoxysilane (NCC ₃ H ₆ Si (OC ₂ H ₅ ) ₃ ).

[0011] The amount of the organic silane is an amount to be 5 to 15% by weight relative to the carbon in terms of the content of the reinforcing agent (W _B). This is because if it is less than 5% by weight, the water repellency effect becomes insufficient, and even if the amount exceeds 15% by weight, the effect is not changed and the cost is increased. In particular,
About 2.5 to 7.5 parts by weight is preferable per 100 parts by weight of the rubber component. Further, the rubber composition used in the present invention is a vulcanizing agent which is a compounding agent used in a usual rubber industry,
A vulcanization accelerator, a vulcanization acceleration aid, an antiaging agent, etc. are appropriately mixed.

A rubber composition satisfying the above requirements is
Explain that it is excellent in water repellency. In addition to the rubber composition shown in Table 1, carbon black (N22
0) was compounded in 50 parts by weight. This carbon black (N
A typical characteristic value of 220) is an iodine adsorption amount; 118 mg
/ G, DBP absorption amount; 114cm ³ / 100g, average particle
Diameter: 23 nm, nitrogen adsorption specific surface area: 114 m ² / g,
Is.

[0013]

[Table 1]

The relationship between the content (wt%) and the water absorption ratio (%) of the organic silane contained in this rubber composition with respect to the carbon equivalent content is shown in the graph of FIG. In the graph of FIG. 1, the vertical axis is the water absorption ratio (%), and the horizontal axis is the content ratio (% by weight) with respect to the carbon-equivalent content of the organic silane. As can be seen from FIG. 1, when the content of the organic silane is about 5% by weight, the water absorption ratio becomes about 50% or less, and when the content of the organic silane exceeds 15% by weight, the effect of reducing the water absorption ratio is so much. does not change. The tendency as shown in FIG. 1 generally shows a similar tendency although there are some differences depending on the type of rubber composition.

Here, the water absorption ratio is an index of the water absorption of the sample when the water absorption of an equivalent rubber composition except that it does not contain any organic silane is 100.
The water absorption is a sample after a rubber sample piece having a length x width x thickness of 1 cm x 1 cm x 2 mm is immersed in water at room temperature for 48 hours and then taken out, and water adhering to the surface of the sample piece is quickly wiped off. The weight of the piece was measured, the amount of increase due to immersion (increase amount = weight after immersion−weight before immersion) was calculated, and the increase amount was divided by the weight of the sample piece before immersion (water absorption =
(Increase / weight before immersion) × 100).

Next, the effects of the present invention will be described based on specific examples. The rubber composition shown in Table 1 was mixed with the reinforcing agent shown in Table 2 and the organic silane in the amounts shown in Table 2 to prepare the rubber compositions of Examples 1 to 9 and the rubber compositions of Comparative Examples 1 to 3. . As the organic silane, phenyltrimethoxysilane manufactured by Toray Dow Corning Silicon Co., Ltd.
Nipsil VN3 (trade name) made by Nippon Silica as silica
As a clay, a hard clay crown manufactured by Shiraishi Calcium Co., Ltd. was used. Test pieces were prepared using the rubber compositions of Examples 1 to 9 and the rubber compositions of Comparative Examples 1 to 3, and the water absorption rate was measured based on the above method. The results are shown in Table 2. Further, tires using these rubber compositions for tread rubber were produced, and the wear ratio, the tensile resistance ratio, and the amount of mud carried out from the field were evaluated by the following methods. The evaluation results are also shown in Table 2. [Evaluation method] Abrasion ratio: After running on the paved road surface for 300 hours with the manufactured tire, the wear amount of the tread surface was measured. The abrasion amount in the case of the rubber composition (Comparative Example 1) in which only carbon black was blended as a reinforcing agent and no organosilane was blended at all was represented as an index by the abrasion amount after the running.
The smaller the wear ratio value, the larger the wear amount.

Tear resistance ratio: Measured based on JIS K6301, and the tear resistance was measured. The tear resistance value of the rubber composition (Comparative Example 1) containing only carbon black as a reinforcing agent and no organic silane at all was 10
The tear resistance value of the sample was represented by 0 as an index. The smaller the value of the tear resistance ratio, the smaller the tear resistance of the sample. Amount of mud carried out from the field: The tire was made to run in the field for 6 hours, the tread surface condition of the ear after running was visually observed, and the amount of mud adhered was evaluated as ○ (almost no adhesion) to × ( (A large amount is attached).

[0018]

[Table 2]

[Evaluation] As can be seen from Table 2, organic silane was used within the scope of the present invention.
That is, a vehicle tire manufactured using a rubber composition (Examples 1 to 9) containing an amount of 5 to 15% by weight with respect to the carbon-converted content has a low water absorption rate, and the mud from the field is reduced. It can be seen that the amount taken out of is also decreasing. On the other hand, when the organosilane was not contained at all or the content was small (Comparative Examples 1 and 2), the water absorption was high and the amount of mud taken out from the field was large and inferior. By replacing a part of the reinforcing agent with silica or clay, the wear ratio and the tear resistance ratio tend to be lowered, but the silica and clay contents and the carbon black content satisfy the above formula. In the range, it doesn't matter so much.

It should be noted that Comparative Example 3 has the same level of performance as that of the Example, but is not preferable because it is expensive.

[0021]

EFFECTS OF THE INVENTION A vehicle tire using a rubber composition containing a predetermined amount of a predetermined organic silane as a tread rubber,
The water absorption is small, and the adhesion of mud when traveling in mud and wetlands is greatly improved. Therefore, if the tire of the present invention is used for the tire of an agricultural or construction vehicle that travels in a field area such as a mud zone or a wetland containing a caking soil,
It is possible to prevent the paved road from being contaminated when moving through muddy ground, and to prevent the spread of infection by pathogenic bacteria even when traveling in multiple fields.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the content ratio of organic silane and the water absorption ratio with respect to the carbon content.

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Claims (3)

(57) [Claims] 1. A diene rubber component having a general formula of Y--Si (OR)
₃ (wherein Y represents C ₆ H ₅ −, CH ₃ C ₆ H ₄ −, CF ₃ C ₂ H ₄ −, NCC ₃ H ₆ −, and R represents CH ₃ − or C ₂ H ₅ −. Representing) is a vehicle tire using a rubber composition containing an organic silane and a reinforcing agent as a tread rubber, the content of the organic silane, the content of the reinforcing agent is converted to carbon black 5 for the converted carbon content
Ri amount der to be 15 wt%, and the reinforcing agent, car
Bon Black and at least one of silica or clay
Vehicle tire and wherein the mixture der Rukoto consisting only. 2. A 35 to 65 parts by weight as before Kiho strong amount 100 parts by weight per carbon converted content rubber component agent, the content of carbon black relative to 100 parts by weight of the rubber component B, containing silica The vehicle tire according to claim 1, wherein the following formula B ≧ (S / 1.2) + (C / 1.4) is satisfied, where S is the amount and C is the content of clay. 3. The content of the organic silane per 100 parts by weight of the rubber component is 2.5 to 7.5 parts by weight.
Or the vehicle tire according to 2.