JPH09207508A - Pneumatic radial tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an adhesion quantity of an adhesive and to accomplish softening and reduction in weight of fiber by covering a carcass ply reinforcing polyester fiber surface with an adhesive composition containing a silicate compound with the predetermined weight ratio of silicon to magnesium. SOLUTION: For polyester fiber used as carcass ply reinforcing fiber, polyethylene terephthalate or high polymer linear polyester consisting of ethylene terephthalate units mainly is used. A silicate compound contained in an adhesive composition covering the surface of the reinforcing polyester fiber contains silicon and magnesium at the weight ratio of 1/(0.1-1.0). In addition, sodium, fluorine, and aluminum can be contained. A silicate compound, synthetic smectites especially, works as a permeation suppressing agent and a softening agent, so that adhesion between the polyester fiber and rubber can be stabilized even if an adhesion quantity to the polyester fiber is reduced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an improvement in a pneumatic radial tire. More specifically, the present invention relates to a pneumatic radial tire for passenger cars, which is effective in reducing the weight and improving the durability.

[0002]

2. Description of the Related Art Rayon fiber, polyamide fiber and polyester fiber have been conventionally used as an organic fiber as a carcass reinforcing material for radial tires for passenger cars. However, rayon fiber has problems such as dirty water and bad odor in the manufacturing process. Polyamide fibers are mainly used in recent years because they are large and polyamide fibers have excellent durability but poor creep resistance.

However, while polyester fibers have high strength and excellent physical properties such as excellent creep resistance and fatigue resistance, on the other hand, the adhesiveness between the fibers and rubber is not sufficient, so that the characteristics are sufficient. It was difficult to make it work.

For this reason, many proposals have been made in the past for improving the adhesiveness of polyester fibers to rubber. For example, Japanese Patent Publication No. 60-22626 discloses a blocked isocyanate compound, an epoxy, and the like as a first treatment liquid. Polyester fiber is treated with a mixture of highly reactive compounds such as compounds and rubber latex to activate the fiber surface, and then resorcin
Mixture of formalin resin and rubber latex (hereinafter RF
(Referred to as L).

However, although the polyester fiber obtained by the above method has improved adhesiveness, the treated fiber becomes hard, and the fiber is apt to fatigue when repeatedly stretched and contracted in the tire. However, there is a problem that the tire life is shortened and that the molding process of the tire becomes difficult due to the hard fibers.

In Japanese Patent Publication No. 57-29586, a method of applying an adhesive in a two-step system, that is, a polyester fiber is first treated with a first treatment liquid consisting of a mixed liquid of an epoxy compound, a blocked isocyanate compound and bentonite. A method of treating and then treating with a second treatment liquid in which an ethylene urea compound is added to RFL is disclosed.
The polyester fiber obtained by this method has a low heat-resistant adhesive strength and thus has a poor tire life during high-speed running. Further, the bentonite contained in the first treatment liquid has a high true specific gravity and has a large particle size, which easily settles and adheres. There was a problem with the stability of the agent.

On the other hand, since the amount of adhesion of the adhesive to the polyester fiber and the adhesiveness are in a proportional relationship, if the amount of the adhesion of the adhesive to the polyester fiber is reduced, the adhesiveness between the fiber and the rubber will decrease, and the tire The problem arises that burst failures are more likely to occur. Therefore, it has been conventionally considered difficult to reduce the amount of adhesive attached.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of studying how to solve the above-mentioned problems in the prior art.

Therefore, the main object of the present invention is to reduce the amount of the adhesive adhered to the tire-reinforcing polyester fiber so that the excellent adhesiveness can be maintained even if the fiber is made soft and lightweight. Accordingly, it is to provide a pneumatic radial tire capable of reducing the weight and improving the durability of the tire.

[0010]

In order to achieve the above object, a pneumatic radial tire of the present invention is a pneumatic radial tire in which a carcass ply reinforced with polyester fiber is arranged inside a tread of the tire. The surface of the polyester fiber is coated with an adhesive composition containing an adhesive matrix component containing at least a silicate compound, and the silicate compound is composed of at least silicon and magnesium.
The weight ratio of magnesium is 1 / (0.1 to 1.0).

Further, in the pneumatic radial tire of the present invention, the silicate compound has a magnesium content of 5% by weight or more and a light transmittance T of a 1% aqueous dispersion.
Is 50% or more, and the thixotropy index of a 2% aqueous dispersion is preferably 2.0 to 10.0. An optimum example of this silicate compound is smectite of synthetic clay. .

Further, the polyester fiber used as a reinforcing material for the pneumatic radial tire of the present invention is preferably a cord having a lower twist and an upper twist, and the adhesion of the adhesive composition coating the surface thereof. The agent matrix component is composed mainly of a mixture of resorcinol / formaldehyde / rubber latex, or 10 to 25% by weight of polyepoxide compound and 20 to 35% by weight of blocked polyisocyanate compound and / or ethyleneurea. It is preferably composed of a mixture containing a compound and 0 to 70% by weight of rubber latex,
Further, the composition should have a silicate compound added in an amount of 1 to 15% by weight, and the amount of the adhesive composition deposited should be 0.5 to 3.0% by weight based on the dry weight of the polyester fiber. preferable.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

In the pneumatic radial tire of the present invention, the tire reinforcing material, that is, the polyester fiber used as the reinforcing fiber of the carcass ply is made of polyethylene terephthalate or a high molecular weight linear polyester mainly composed of ethylene terephthalate units. Preferably, this is in the form of filament yarns, cords, woven fabrics, woven fabrics and the like made of a material, and is characterized in that the surface thereof is coated with an adhesive composition described in detail below, with a twist coefficient of 1500 in particular. It is desirable to have a cord form in which the twist of ~ 2300 is applied in the opposite directions of the lower twist and the upper twist.

Next, in the pneumatic radial tire of the present invention, the silicate compound contained in the adhesive composition for coating the surface of the reinforcing polyester fiber is silicon and magnesium in a weight ratio of 1 / (0.1 To 1.0), preferably an inorganic compound further containing sodium and lithium, and may further contain fluorine and / or aluminum as constituent elements. A typical example thereof is a synthetic inorganic compound generally called smectite. The content of magnesium is 5% by weight, particularly 10% by weight or more, and the light transmittance T of the 1% aqueous dispersion is preferably 50% or more, particularly 70% or more, and the thixotropy index TI of the 2% aqueous dispersion is preferable. Is 2.0-1
It is preferably 0.0, particularly 3.0 to 9.0. Furthermore, B. E. FIG. The specific surface area measured by the T1 point method is 1
It is preferably in the range of 00 to 500, particularly 150 to 400.

The light transmittance T, thixotropy index and specific surface area referred to in the present invention are values obtained by the following method.

[Light transmittance T] A 1% aqueous solution of a silicate compound was thoroughly stirred and then put into a 10 mm cell to give U-33.
Wavelength 500nm using 00 type spectrophotometer (Hitachi)
It is a value obtained by measuring the light transmittance in.

[Thixotropic index TI] A 2% aqueous dispersion of a silicate compound was thoroughly stirred and then allowed to stand for one day and night, and the viscosity of the aqueous dispersion which had not been separated by sedimentation was measured by a B-type viscometer (manufactured by Shibaura System Co., Ltd.). ). The rotor is No. Use 3 and rest at 6 rpm and 60 rpm for 2 minutes before measurement,
It is the ratio of the viscosities after one minute of rotation. TI = (viscosity at 6 rpm) / (viscosity at 60 rpm) [specific surface area] Specific surface area meter A special cell of a Qantasoap (manufactured by Yuasa Ionics Co., Ltd.) was weighed, and then the silicate compound was ½ in this cell Weigh about (about 0.15g), weigh,
The specific surface area is calculated by the following formula by measuring with a canter soap according to a conventional method. Specific surface area (m ² /g)=(A/AC)×(V×2.81
/ Sample amount g) A: Value of integrator after removing cell from liquid nitrogen and immersion in water at room temperature AC: Value of integrator after injecting pure liquid nitrogen gas V: A / 1300

A silicate compound having such characteristics,
In particular, synthetic smectite is a thixotropic dispersion when dispersed in water, and stable viscosity is obtained, so even if the concentration of the matrix component of the adhesive composition is low, aggregation of each adhesive matrix component is suppressed and stable. Since the adhesive matrix component uniformly adheres to the fiber surface, even if the amount of adhesive adhered to the polyester fiber is reduced, excellent adhesiveness with rubber can be obtained.

Furthermore, since the above silicate compound is hydrophilic, water molecules in the adhesive composition are adsorbed and penetrate into the inside of the fiber cord, and the epoxy compound, the isocyanate compound and the rubber matrix such as the rubber latex matrix are adsorbed. Permeation of the component into the fiber cord is suppressed. When heat treatment is applied in this state, the matrix component is solidified in the surface layer portion of the fiber cord, so that the degree of freedom between fiber single yarns is large and the fiber cord has improved flexibility.

That is, the silicate compound in the present invention acts as a penetration inhibitor and a softening agent, and even if the amount of adhesion of the adhesive composition containing the silicate compound to the polyester fiber is reduced, the polyester fiber The adhesiveness between rubber and rubber is stable and excellent, and the treated cord is flexible and maintains the original strength of the fiber.

The polyester fiber, which is a reinforcing material for the pneumatic radial tire of the present invention, is subjected to an adhesion treatment by a one-bath prescription or a two-bath prescription, but the silicate compound is treated in a one-bath prescription liquid or a two-bath prescription. It may be added to the first treatment liquid.

The above-mentioned one-bath formulation means that the adhesive composition is applied to the polyester fiber in one step, and subsequently 70 to 1 is applied.
This is a method of performing heat treatment at 200 to 225 ° C. after drying at 50 ° C., which is a one-bath adhesive composition (hereinafter referred to as treatment liquid A
Is a mixture of resorcin-formaldehyde initial condensate (RF resin) and rubber latex (RFL).
The main component of the RF resin is preferably an RF resin obtained under an alkali catalyst, and RFL is a novolac type condensate of resorcin and formalin or a chlorophenol compound for improving the adhesiveness. It is preferable to contain a sorption adhesive.

In the above RFL, the resorcinol and the formalin initial condensate are those obtained under an alkaline catalyst.
The molar ratio of resorcin and formalin is 1: 0.3 to 1:
The range of 5, especially 1: 0.75 to 1: 2.0 is preferable.

When using a novolak type condensate of resorcin and formalin in the above RFL,
It is preferable to add formalin after dissolution in an alkaline catalyst aqueous solution to obtain the same molar ratio as that of resorcin and formalin initial condensate.

As the rubber latex in the RFL (Treatment liquid A), natural rubber latex, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex, vinyl pyridine / styrene / butadiene rubber latex and the like are used. Can be used alone or in combination.

The treatment liquid A is preferably used as a solution (including a dispersion liquid) in which the total solid content concentration of the adhesive matrix component is 5 to 20%, particularly 8 to 16%.

The two-bath formulation is a method of applying the adhesive composition to polyester fibers in two steps,
First, the first adhesive composition (hereinafter, referred to as treatment liquid B) is applied, and subsequently dried at 70 to 150 ° C., and then 20
This is a method in which heat treatment is performed at 0 to 225 ° C., then a second adhesive composition (hereinafter referred to as treatment liquid C) is applied, and drying and heat treatment are performed as in the case of treatment liquid B.

The treatment liquid B contains a polyepoxide compound, a blocked polyisocyanate compound and / or an ethyleneurea compound, and a rubber latex in an amount of 10 to 25.
%, 20 to 35% by weight, and 0 to 70% by weight as a main component of the adhesive matrix.
Preferably has a mixture of RFL and an ethylene urea compound as the main component of the adhesive matrix.

Here, when the compounding amounts of the polyepoxide compound, the blocked polyisocyanate compound and / or the ethyleneurea compound are smaller than the above proportions, respectively, the initial adhesive strength of the treated synthetic fiber tends to be lowered. Therefore, it is not preferable.

The polyepoxide compound contained in the treatment liquid B is a compound containing two or more epoxy groups in one molecule, and specifically, glycerol, pentaerythritol, sorbitol, ethylene glycol, polyethylene glycol, propylene. Reaction products of polyhydric alcohols such as glycol and polypropylene glycol with halogen-containing epoxides such as epichlorohydrin, resorcin, bis (4-hydroxyphenyl) dimethylmethane, phenol / formaldehyde resin, polyhydric phenol such as resorcin / formaldehyde resin , A reaction product of halogen-containing epoxides with bis-
(3,4-epoxy-6-methyl-dicyclohexylmethyl) adipate, polyepoxide compound obtained by oxidizing unsaturated bond moiety such as 3,4-epoxycyclohexene epoxide, bisphenol A type epoxy compound or bisphenol A type urethane modified epoxy Examples thereof include compounds. Among them, reaction products of polyhydric alcohols and epichlorohydrin (polyglycidyl ether compounds of polyhydric alcohols) are preferably used.

The blocked polyisocyanate compound contained in the treatment liquid B is a compound which liberates a blocking agent by heat to produce an active isocyanate compound, and specifically, tolylene diisocyanate, metaphenylene diisocyanate, diphenyl methane. Polyisocyanate compounds such as diisocyanate, hexamethyline diisocyanate and triphenylmethane triisocyanate, and phenols such as phenol, cresol and resorcin, lactams such as ε-caprolactam and valerolactam, oximes such as acetoxime, methyl ethyl ketone oxime and cyclohexane oxime. And reaction products with a blocking agent selected from ethyleneimine and the like.

Among these blocked polyisocyanate compounds, the use of aromatic polyisocyanate compounds blocked with ε-caprolactam and aromatic compounds of diphenylmethane diisocyanate give particularly good results.

Similarly, the ethyleneurea compound contained in the treatment liquid B is a compound which reacts by opening the ethyleneimine ring upon heating to improve the adhesiveness, and representative examples thereof include hexamethylene diisocyanate and triethylene. Examples thereof include reactive products of aromatic and aliphatic isocyanates such as diisocyanate, diphenylmethane diisocyanate and triphenylmethane triisocyanate, and ethyleneimine. Among these ethylene urea compounds, the use of aromatic ethylene urea compounds of diphenylmethanediethylene urea gives particularly good results.

As the rubber latex contained in the treatment liquid B, a latex such as natural rubber latex, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex and vinylpyridine / styrene / butadiene rubber latex may be used alone or. It can be mixed and used.

The treatment liquid B is preferably used as a solution (including a dispersion liquid) having a total solid content concentration of the adhesive matrix component of 2 to 10%, particularly 4 to 7%.

The treatment liquid C (second treatment liquid) applied to the synthetic fibers after the treatment liquid B is preferably a mixture of RFL and an ethylene urea compound, and the rubber latex in the RFL is Vinylpyridine-styrene-similar to that used in the first treatment liquid
Butadiene copolymer latex, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, chloroprene rubber latex, chlorosulfonated polyethylene latex, acrylate rubber latex and natural rubber latex are used appropriately.

As the ethylene urea compound contained in the treatment liquid C, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate and the like are used as in the treatment liquid B. Examples thereof include a reaction product of an aromatic or aliphatic isocyanate and ethyleneimine.

In the treatment liquid C, the blending amount of the ethylene urea compound added for improving the adhesiveness is preferably 3 to 30% by weight, more preferably 10 to 20% by weight based on RFL. Here, the blending amount of the ethylene urea compound is 3
If it is less than 10% by weight, the effect of improving the adhesiveness is small, and even if it is added in an amount of more than 30% by weight, the improvement of the adhesiveness becomes saturated, which rather causes a negative factor such as a decrease in the curing strength, which is not preferable.

The treatment liquid C has a total solid content of the adhesive matrix component of 5 to 20%, particularly 7 to 15%.
It is preferable to use it as a solution (including a dispersion liquid).

The amount of the silicate compound added is the above-mentioned treatment liquid A.
Alternatively, the adhesive matrix component 10 contained in the treatment liquid B
The treatment liquid A is preferably 1 to 15% by weight with respect to 0% by weight.
2 to 5% by weight in the case of, and 3 to 10 in the case of treatment liquid B.
It is particularly preferable to add it in the range of% by weight.

If the amount of the silicate compound added is less than 1% by weight, the effect of improving the flexibility and fatigue resistance of the treated fiber cord is not sufficient, and if it exceeds 15% by weight, the treated fiber cord is added to the rubber. It is not preferable because the adhesiveness tends to decrease.

The adherence rate of the matrix component of the adhesive composition to the polyester fiber cord is 0.5 to 3.0% by weight, preferably 1 to 2% by weight, based on the dry weight of both the 1-bath formulation and the 2-bath formulation. The optimum range is 0.0 to 2.0% by weight.
If it is less than 0.5% by weight, the adhesive strength will be reduced, and if it exceeds 3.0% by weight, the cord will be hard and the fatigue resistance will be reduced, which is not preferable.

The pneumatic radial tire of the present invention, which is reinforced with the rubber-reinforced polyester fiber having the above constitution, is lightweight and exhibits high durability and high performance.

[0045]

EXAMPLES Next, the present invention will be described in detail with reference to examples. Each measurement value was obtained by the following method.

(1) Stability of treatment liquid After the treatment liquid is prepared, it is allowed to stand for one day and night. If the treatment liquid is in a uniform state, it is evaluated as good (◯), and if it is separated by sedimentation, it is evaluated as bad (×). .

(2) Adhesion Strength of Pulling Out According to the adhesion strength-A method of JIS L-1017 (1983), the treated cord was embedded in unvulcanized rubber under the following conditions.
After press vulcanization at 150 ° C for 30 minutes under pressure, after allowing the cord to cool, the cord was pulled out from the rubber block at a speed of 30 cm / min, and the pulling load was divided by the straight line fineness of the treated cord and displayed in g / d. Is.

(3) Cord hardness The treated cord was straightened and cut into 2 cm, and bridges (1 cm interval, φ: 0.6) of the Tensilon tensile tester were cut.
Hook bar (φ: 0.
6 mm) was applied to the center of the cord and lowered (2 cm / min) to obtain the maximum stress, which was defined as the cord hardness.

(4) Adhesion amount of resin Determined by a gravimetric method according to JIS L-1017 (1983).

(5) High-speed durability With respect to the test tires, a drum tester was used to run the tires at a speed of 80 km / hour for 120 minutes, and after allowing them to cool for 3 hours or more, the test air pressure was adjusted and the actual running was started. . The actual running starts from a speed of 120 km / hour, and the speed is increased stepwise by 10 km / hour every 30 minutes of running, and the failed speed is recorded, and the value of Comparative Example 2 is set to 100 and displayed as an index.

The silicate compounds used in the following examples are synthetic smectites satisfying the requirements of the present invention, and the silicate compounds used in Comparative Examples are natural silicate compounds not satisfying the requirements of the present invention. It is an acid salt compound.

[Examples 1 to 5, Comparative Examples 1 and 2] Epoxy / blocked isocyanate / rubber latex in a solid content weight ratio of 11.0 / 23.0 / 66.0, mixed 100 parts by weight To the parts, an aqueous solution of a silicate compound having the properties shown in Table 1 or Table 2 (2% by weight) was added at a ratio shown in Table 1 or Table 2, respectively, and the solid content of each mixed solution was 6% by weight. The first treatment liquid was adjusted by setting the percentage to be%.

On the other hand, as the second treatment liquid, the molar ratio of resorcin-formalin (R / F) was 1 / 1.5 and the solid content concentration was 10% by weight.
14.3 parts by weight of resorcin / formalin initial condensate (RF resin) obtained by aging for 24 hours was added to 100 parts by weight of vinyl pyridine / styrene / butadiene copolymer latex (VP latex), followed by aging for 24 hours, RFL
The solid content concentration is set to 20% by weight, and the RFL100
In parts by weight diphenylmethane-bis 4,4'-N, N'-
It was adjusted by adding 10 parts by weight of an aqueous dispersion of diethylene urea and adjusting the solid content concentration to 12%.

[0054] The polyethylene terephthalate was melt-spun by a conventional method high Haya引up and stretched to 1500 denier obtained, which is a single number of yarns 360 multifilament (intrinsic viscosity 0.95), 40 times each per 10cm After twisting the lower twist, two of the lower twist cords were combined and the same number of upper twists were applied in the opposite direction of the lower twist to obtain a raw cord.

Then, using a Ritzler computer treating machine single dipping machine, each of the first treatment liquids was applied to the raw cord so that the resin adhesion amount was 1.5%, and then the drying zone was set to 120. 1 at ℃
After passing a fixed length for 00 seconds, stretching was applied so that the tension in the hot stretch zone would be 0.80 g / d, and treatment was performed at 240 ° C. for 40 seconds. Subsequently, the second treatment liquid was applied so that the amount of resin adhering to the resin was 1.5%, and after passing through the drying zone at 100 ° C. for a fixed length of 100 seconds, the tension in the hot stretch zone was 0.70 g. / D
And stretch for 30 seconds at 240 ° C, then in normalizing zone at 240 ° C for 30 seconds.
Heat treatment was applied for 2.0 seconds with a relaxation of 2.0%.

Radial tires (tire size 165-SR13) were obtained by using each of the treated cords obtained by the above-mentioned method as a carcass material in the same manner as in a normal tire manufacturing process.
Was manufactured. Two steel belts were arranged inside the tread for reinforcement.

In Comparative Examples 1 and 2, only the silicate compound of the first treatment liquid was changed and the silicate compound was not added. The procedure was the same as in the example. The evaluation results of the first treatment liquid, the adhesive cord, and the tire are also shown in Tables 1 and 2.

[0058]

[Table 1]

[0059]

[Table 2]

As shown in Tables 1 and 2, in the case of the present invention, a tire having higher adhesiveness than the case of the comparative example, a flexible cord, and a markedly excellent high-speed durability was obtained. .

[Examples 6 to 9 and Comparative Examples 3 to 5] 1 mol of resorcin and 1.50 of formalin in the presence of an alkali catalyst.
The vinylcondensate / styrene / butadiene copolymer latex (VP latex) 10 was used as an initial condensate (RF resin) having a solid content concentration of 10%, which was obtained by aging 2 moles for 2 hours.
12.5 parts by weight was added to 0 parts by weight and aged for 24 hours.

Then, as a sorption adhesive, "Denabond" (manufactured by Nagase Kasei Co.) or "Sumikanol" 750
2 (manufactured by Sumitomo Chemical Co., Ltd.) based on 100 parts by weight of the RFL.
5 parts by weight was added, the solid content was adjusted to 14% with water, and the mixture was aged for 24 hours.

An aqueous solution (2% by weight) of a silicate compound having the properties shown in Table 3 or Table 4 was added to 100 parts by weight of the above mixture at a ratio shown in Table 3 or 4, respectively, The treatment liquid was adjusted by adjusting the solid content of each mixed liquid to 12% by weight.

A polyethylene terephthalate was melt-spun and stretched by a conventional method to obtain 1,500 denier multifilaments (intrinsic viscosity 0.95).
After twisting 40 times per cm, this twisted cord 2
The cords were put together and the same number of upper twists was applied in the opposite direction to the lower twist to make a raw cord.

Next, each processing liquid was applied to the above-mentioned raw cord so that the amount of resin adhered to the raw cord was 1.5% by using a computer treating machine single dipping machine manufactured by Ritzler. After passing a fixed length for 2 seconds, stretch it so that the tension in the hot stretch zone is 0.80 g / d.
It was treated at 50 ° C. for 30 seconds and then heat treated in the normalizing zone at 250 ° C. for 30 seconds with a relaxation of 1.5%.

Radial tires (tire size 165-SR13) were manufactured in the same manner as in the normal tire manufacturing process, using the treated cords obtained by the above-mentioned method as carcass materials. Two steel belts were arranged inside the tread for reinforcement.

Comparative Examples 3, 4 and 5 were the same as those in Examples 8 and 7 except that only the silicate compound in the first treatment liquid was changed, and the silicate compound was not added. Example 8 is the same as Example 8, and the tire manufacturing method is Example 6
The same was done as in ~ 9. The evaluation results of each treatment liquid, the adhesive cord and the tire are also shown in Tables 3 and 4.

[0068]

[Table 3]

[0069]

[Table 4]

As shown in Tables 3 and 4, the radial tires of the present invention were remarkably excellent in high speed durability as compared with the comparative examples.

[0071]

According to the present invention, it is possible to maintain excellent adhesiveness with rubber even if the amount of adhesive attached to the cord is reduced to make the cord softer and lighter. Therefore, it is possible to reduce the weight of the tire. It is a pneumatic radial tire with improved durability and high performance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C09J 121/02 JEJ C09J 121/02 JEJ 161/06 JET 161/06 JET 163/00 JFL 163/00 JFL 175/04 JEZ 175/04 JEZ

Claims (10)

[Claims] 1. A pneumatic radial tire comprising a carcass ply reinforced with polyester fibers arranged inside a tire tread, wherein the surface of the polyester fibers contains at least a silicate compound as an adhesive matrix component. The silicate compound is composed of at least silicon and magnesium, and the weight ratio of silicon / magnesium is 1 / (0.1 to 1.0). Pneumatic radial tire. 2. The magnesium content in the silicate compound is 5% by weight or more.
The described pneumatic radial tire. 3. The pneumatic radial tire according to claim 1, wherein the silicate compound further contains sodium and lithium elements. 4. A 1% aqueous dispersion of the silicate compound has a light transmittance T of 50% or more, and a 2% dispersion has a thixotropy index TI of 2.0 to 10.0. The pneumatic radial tire according to claim 1, 2, or 3. 5. The pneumatic radial tire according to claim 1, wherein the silicate compound is smectite. 6. The polyester fiber has a twist coefficient of 150.
The pneumatic radial tire according to any one of claims 1 to 5, which is a cord in which the lower twist and the upper twist of 0 to 2300 are respectively applied in opposite directions. 7. The air according to claim 1, wherein the adhesive matrix component of the adhesive composition is mainly composed of resorcin / formaldehyde / rubber latex. Radial tires with. 8. The adhesive matrix component of the adhesive composition comprises 10 to 25% by weight of a polyepoxide compound.
7. A mixture of 20-35% by weight blocked polyisocyanate compound and / or ethyleneurea compound and 0-70% by weight rubber latex, characterized in that it is composed of a mixture. Pneumatic radial tire as described in. 9. The pneumatic radial tire according to claim 1, wherein the amount of the silicate compound added to the adhesive matrix component is 1 to 15% by weight. 10. The amount of the adhesive composition deposited is 0.5 to 3.0% by weight based on the dry weight of the polyester fiber.
The pneumatic radial tire according to any one of claims 1 to 9, wherein