JP2021094962A - tire - Google Patents

Abstract

To provide a tire which uses a cord using polyamide as a reinforcement cord of a reinforcement member of the tire and has improved performance.SOLUTION: In a tire 10 provided with a belt 2 composed of at least one belt layer outside in a tire radial direction of a carcass 1, and a belt reinforcement layer 3 composed of a rubber coated layer of a reinforcement cord extending in a tire circumferential direction outside in a tire radial direction of the belt 2, at least either the carcass 1 or the belt reinforcement layer 3 has as a structural element a rubber-cord composite in which a reinforcement cord arranged in parallel without being twisted is embedded in the rubber. The reinforcement cord contains a semiaromatic polyamide monofilament composed of condensation polymer of dicarboxylic acid and non-aromatic diamine containing aromatic dicarboxylic acid or diamine condensation polymer containing non-aromatic dicarboxylic acid and aromatic diamine.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tire, and more specifically, to provide a tire having improved performance by using a cord using polyamide as a reinforcing cord of a tire reinforcing member.

In recent years, environmental problems such as global warming due to an increase in _{CO 2 emissions and resource depletion problems have become more serious.} For this reason, tires are required to be lightweight and have low fuel consumption. Conventionally, tires have been actively improved and developed in terms of shape, structure, rubber characteristics such as tread, etc., and the weight has been reduced by reducing the amount of rubber used and the rolling resistance of the tire. , Fuel efficiency has been improved. Since the rubber member is greatly involved in rolling resistance, for example, the loss of the rubber member itself such as tread rubber, bead filler rubber, belt coating rubber, and bead filler rubber can be reduced, and the shape and structure of the rubber member can be adjusted. Low distortion has been studied and optimized.

Recently, with the progress of lowering the loss of the rubber member itself, the involvement of the loss in the rolling resistance due to the dynamic repetitive strain of the members other than the rubber member cannot be ignored. Members other than the rubber member include a carcass ply layer, a belt layer, a belt reinforcing layer, etc. Among these, the belt reinforcing layer has a large strain fluctuation at the time of rolling contact, so that the loss of the belt reinforcing layer is reduced. Technology is desired. Under such circumstances, in Patent Document 1, it can be suitably used as a cap ply layer (belt reinforcing layer) in a tire, has excellent mechanical characteristics such as rigidity, thermal characteristics, etc., and reinforcement with reduced loss only. Cord materials have been proposed.

JP-A-2002-103913

Currently, organic fibers such as polyester, rayon, and nylon are used for reinforcing members of tires. Among these, nylon fiber, which is a polyamide fiber, has an advantage that it has excellent adhesiveness to rubber and also has excellent fatigue resistance as compared with other fiber types. However, the weight reduction and durability are not always sufficient, and further improvement is required at present.

Therefore, an object of the present invention is to provide a tire having improved performance by using a cord using polyamide as a reinforcing cord of a tire reinforcing member.

As a result of diligent studies to solve the above problems, the present inventor has obtained the following findings. That is, by using a predetermined polyamide monofilament as a cord instead of a cord composed of a multifilament in which polyamide filaments are twisted as a reinforcing cord, a cord composed of a multifilament in which polyamide filaments are twisted is compared with a cord. It has been found that the tensile strength can be improved, the durability can be further improved, and the rolling resistance can be reduced. As a result of further diligent studies based on such findings, the present inventor has found that the above problems can be solved by adopting the following configuration, and has completed the present invention.

That is, the tire of the present invention is a tire provided with a belt composed of at least one belt layer on the outer side in the radial direction of the carcass tire and at least one layer of a belt reinforcing layer on the outer side in the radial direction of the tire of the belt. ,
At least one of the carcass and the belt reinforcing layer has a rubber-cord composite as a component, in which reinforcing cords arranged in parallel without twisting are embedded in rubber.
The reinforcing cord comprises a semi-aromatic polyamide monofilament composed of a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine or a polycondensate of a diamine containing a non-aromatic dicarboxylic acid and an aromatic diamine. It is characterized by.

In the tire of the present invention, the semi-aromatic polyamide is preferably a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine, and the non-aromatic diamine is an aliphatic diamine and an alicyclic. It is preferably at least one of the group diamines. Further, in the tire of the present invention, the diameter of the monofilament is preferably 0.1 to 1.0 mm. Further, in the tire of the present invention, the driving interval of the monofilaments is preferably 0.01 mm to 1.0 mm.

Further, in the tire of the present invention, the ratio of the aromatic dicarboxylic acid to the dicarboxylic acid of the monofilament is preferably 50 mol% or more. Further, in the tire of the present invention, the ratio of the dicarboxylic acid having one aromatic ring to the aromatic dicarboxylic acid is 20 mol% or more, and the dicarboxylic acid having two aromatic rings to the aromatic dicarboxylic acid. The ratio of the dicarboxylic acid having three aromatic rings to the aromatic dicarboxylic acid is 20 mol% or more, and the ratio of the dicarboxylic acid having three aromatic rings is 20 mol% or more. Furthermore, in the tire of the present invention, the ratio of the diamine having 7 to 12 carbon atoms to the diamine is preferably 20 mol% or more.

The tire of the present invention is suitable for a passenger car tire.

Here, "the ratio of the dicarboxylic acid having one aromatic ring to the aromatic dicarboxylic acid is 20 mol% or more" means that "the ratio of the structural unit derived from the aromatic dicarboxylic acid to the structural unit derived from the raw material monomer component is 10 mol". It means "% or more". "The ratio of a dicarboxylic acid having two aromatic rings to an aromatic dicarboxylic acid is 20 mol% or more", "the ratio of a dicarboxylic acid having three aromatic rings to an aromatic dicarboxylic acid is 20 mol% or more" and "diamine". The ratio of diamine having 7 to 12 carbon atoms to 20 mol% or more is the same.

According to the present invention, it is possible to provide a tire having improved performance by using a monofilament cord using polyamide as a reinforcing cord of a tire reinforcing member.

It is the schematic sectional drawing in the tire width direction of the tire which concerns on one preferred embodiment of this invention. It is sectional drawing of the rubber-cord complex which concerns on one preferred embodiment of the tire of this invention. It is sectional drawing of the rubber-cord complex which concerns on other preferred embodiments of the tire of this invention.

Hereinafter, the tire of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a tire according to a preferred embodiment of the present invention in the tire width direction. The tire 10 of the present invention comprises a belt 2 composed of at least one belt layer on the outer side of the carcass 1 in the tire radial direction, and a rubberized layer of a reinforcing cord extending in the tire circumferential direction on the outer side of the belt 2 in the tire radial direction. It is a tire provided with a belt reinforcing layer 3. In the illustrated example, the carcass 1 straddling the pair of bead cores 4 is composed of one layer of carcass ply, the belt 2 is composed of two layers of belt layers 2a and 2b, and the bead core 4 is outside in the tire radial direction. A bead filler 5 is arranged in the bead filler 5.

In the illustrated example, the belt reinforcing layer 3 is composed of a cap layer 3a arranged so as to cover the entire belt 2 and a pair of layer layers 3b arranged so as to cover only both ends of the cap layer 3a. The cap layer 3a is arranged so as to intersect and continue with the tire equatorial plane E from one tire half to the other tire half, whereas the layer layer 3b does not intersect with the tire equatorial plane E, respectively. The tire is composed of a pair arranged so as to cover only the end portion of the cap layer 3a in the half portion of the tire. In the tire 10 of the present invention, the belt reinforcing layer 3 may include both the cap layer 3a and the layer layer 3b, or may be only the cap layer 3a. Further, the cap layer 3a may be two or more layers, or may be a combination with two or more layer layers 3b. The belt reinforcing layer 3 is usually composed of a rubberized layer of cords arranged substantially parallel to the tire circumferential direction.

In the tire 10 of the present invention, at least one of the carcass 1 and the belt reinforcing layer 3 has a rubber-cord complex as a component, in which reinforcing cords arranged in parallel without being twisted are embedded in rubber. doing. Then, the reinforcing cord contains a monofilament of a semi-aromatic polyamide composed of a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine or a polycondensate of a diamine containing a non-aromatic dicarboxylic acid and an aromatic diamine. .. The semi-aromatic polyamide may have a dicarboxylic acid containing an aromatic dicarboxylic acid or a diamine containing an aromatic diamine, but in particular, the dicarboxylic acid contains an aromatic dicarboxylic acid and a diamine. Is preferably a code using a monofilament made of a polyamide using at least one of an aliphatic diamine and an alicyclic diamine. Nylon 66 is generally used as a reinforcing cord for the carcass 1 and the belt reinforcing layer 3. However, since such a reinforcing cord has a low glass transition temperature Tg (50 ° C.), its rigidity at high temperature is low and steering stability is achieved. Not excellent in sex. On the other hand, the reinforcing cord using aramid fiber can secure the rigidity at high temperature, but has a problem that the rigidity is too high and the tire manufacturability is remarkably poor.

On the other hand, the semi-aromatic polyamide has a high Tg due to intermolecular interaction and has an appropriate rigidity. Therefore, by using it as a reinforcing cord for the carcass 1 and the belt reinforcing layer 3, the productivity of the tire is not impaired. , Durability and steering stability at high speeds can be improved. In addition, the loss tangent tan δ in the tire use range is small, which is advantageous for reducing the rolling of the tire. Further, a polyamide composed of an alicyclic dicarboxylic acid and an aliphatic diamine has high water absorption and low physical stability. On the other hand, since semi-aromatic polyamide has low water absorption, it is possible to secure the stability of physical properties.

FIG. 2 is a cross-sectional view of the rubber-cord complex 20 according to a preferred embodiment of the tire of the present invention. In the illustrated example, five semi-aromatic polyamide monofilaments 21 are arranged in parallel without twisting to form a bundle cord 22, and the bundle cord 22 is embedded in the rubber 23. Further, FIG. 3 is a cross-sectional view of the rubber-cord complex 30 according to another preferred embodiment of the tire of the present invention. In the illustrated example, the monofilament 31 of the semi-aromatic polyamide is evenly embedded in the rubber 33.

The reinforcing cord according to the tire of the present invention, that is, the diameter d of the monofilament made of semi-aromatic polyamide is preferably 0.1 to 1.0 mm. By setting the diameter of the monofilament within such a range, the tensile strength of the monofilament can be made sufficient, and the durability of the tire can be improved. If the diameter d of the filament is less than 0.1 mm, the strength of the single filament is too low and the durability is impaired. On the other hand, if the diameter d of the filament exceeds 1.0 mm, the strain applied to the filament becomes large, and the durability is also impaired. Further, by arranging the cords in parallel without twisting them, the thickness of the carcass ply and the belt reinforcing layer per layer can be reduced, which is advantageous for reducing the weight of the tire 10.

In the tire 10 of the present invention, the driving interval w1 of the monofilament made of the semi-aromatic polyamide in the carcass 1 and the belt reinforcing layer 3 is preferably 0.01 mm to 1.0 mm. By satisfying such a range, the strength and durability of the carcass 1 and the belt reinforcing layer 3 can be sufficiently ensured. If the driving interval w1 is less than 0.01 mm, adjacent cords interfere with each other and durability is impaired. On the other hand, if the number of hits exceeds 1.0 mm, sufficient strength as a treat cannot be exhibited. As shown in FIG. 2, when a plurality of semi-aromatic polyamide monofilaments (five in the illustrated example) are bundled to form a bundle cord, the bundle cord interval w2 is preferably 0.01 to 1.0 mm.

In the tire 10 of the present invention, the Tg of the monofilament of the semi-aromatic polyamide taken out from the tire 10 is preferably 80 to 230 ° C. As described above, by using the cord having a high Tg as the reinforcing cord of the carcass 1 and the belt reinforcing layer 3, the loss tangent tan δ in the tire use area can be reduced, and the rolling resistance of the tire 10 can be improved. Further, since the rigidity can be ensured even at a high temperature, the steering stability at a high speed can be improved. Preferably, the Tg is 100-160 ° C. Here, the glass transition temperature (Tg) is a value measured by differential scanning calorimetry (DSC).

Further, in the tire 10 of the present invention, the ratio of the loss tangent tan δ (25 ° C.) of the semi-aromatic polyamide monofilament taken out from the tire 10 at 25 ° C. to the loss tangent tan δ (100 ° C.) at 100 ° C., tan δ (25 ° C.). The value of ° C.) / tan δ (100 ° C.) is preferably 0.7 to 1.0. In particular, the semi-aromatic polyamide monofilament taken out from the tire preferably has a loss tangent tan δ (25 ° C.) of 0.01 to 0.06 at 25 ° C. Since such a semi-aromatic polyamide monofilament has a low tan δ at high temperatures, it is possible to suppress heat generation and improve the durability of the tire at high speeds. Preferably, the value of tan δ (25 ° C.) / tan δ (100 ° C.) is 0.85 to 1.0. Here, tan δ, which is a monofilament of semi-aromatic polyamide, has a reinforcing cord having a length of 5 cm, a predetermined temperature, a measurement frequency of 10 Hz, a static tension of 100 g, and a dynamic repeating strain of 1000 μm. , Spectrometer, metravib, etc.

Further, in the tire 10 of the present invention, the dynamic elastic modulus E'(25 ° C.) of the semi-aromatic polyamide monofilament taken out from the tire 10 at 25 ° C. and the dynamic elastic modulus E'(100 ° C.) at 100 ° C. The ratio of E'(100 ° C.) / E'(25 ° C.) is preferably 0.7 to 1.0. By setting the value of E'(100 ° C.) / E'(25 ° C.) in the above range, the steering stability at high temperature can be made better. In particular, the semi-aromatic polyamide monofilament taken out from the tire preferably has a dynamic elastic modulus E'(25 ° C.) at 25 ° C. of 0.7 to 0.8. Here, the dynamic elastic modulus E'of the monofilament of the semi-aromatic polyamide can be measured under the same conditions as the measurement of tan δ of the reinforcing cord.

Furthermore, in the tire 10 of the present invention, the water content of the monofilament of the semi-aromatic polyamide taken out from the tire 10 is preferably 0.1 to 2.0% by mass. As described above, the semi-aromatic polyamide monofilament according to the tire 10 of the present invention has low water absorption, so that the stability of the cord physical properties can be ensured. In particular, those having a water content of 0.1 to 2.0% by mass can satisfactorily obtain the effects of the present invention.

The values of tan δ (25 ° C.) / tan δ (100 ° C.) and E'(100 ° C.) / E'(25 ° C.) of the semi-aromatic polyamide monofilament are the types of semi-aromatic polyamide monofilaments. It can be adjusted by appropriately selecting the immersion conditions when immersing in the adhesive applied to the surface of the reinforcing cord, the type of the adhesive, and the conditions of the heat treatment after the adhesive treatment.

In the tire 10 of the present invention, in the rubber-cord composite constituting at least one of the carcass 1 and the belt reinforcing layer 3, all the reinforcing cords may be monofilaments made of semi-aromatic polyamide, but some of them. Reinforcing cords made of other fibers may be used. Examples of other fibers include at least one fiber selected from the group consisting of polyester fiber, nylon fiber, aramid fiber, polyketone fiber, glass fiber, carbon fiber, polyparaphenylene benzobisoxazole fiber and polyallylate fiber. be able to.

Next, a material and a manufacturing method of a monofilament made of a semi-aromatic polyamide according to the tire 10 of the present invention will be described in detail.

<Dicarboxylic acid>
In the semi-aromatic polyamide according to the tire 10 of the present invention, the ratio of the aromatic dicarboxylic acid to the dicarboxylic acid is preferably at least 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more. As a result, a semi-aromatic polyamide monofilament having high Tg, excellent strength and spinnability can be obtained.

The aromatic dicarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. For example, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methyl Examples thereof include aromatic dicarboxylic acids having 8 to 20 carbon atoms, which are unsubstituted or substituted with various substituents such as isophthalic acid and 5-sodium sulfoisophthalic acid. These may be used alone or in combination of two or more.

In the semi-aromatic polyamide monofilament according to the tire 10 of the present invention, examples of the dicarboxylic acid other than the aromatic dicarboxylic acid include an alicyclic dicarboxylic acid having an alicyclic structure having 3 to 10 carbon atoms and a carbon atom. A linear or branched aliphatic dicarboxylic acid of the number 3 to 20 can be used.

Specific examples of the alicyclic dicarboxylic acid having 3 to 10 carbon atoms in the alicyclic structure include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. And so on. In the semi-aromatic polyamide monofilament used for the tire 10 of the present invention, the alicyclic dicarboxylic acid may be unsubstituted or have a substituent. Examples of the substituent include an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a tert-butyl group. However, it is not limited to this. Among these, 1,4-cyclohexanedicarboxylic acid is preferable from the viewpoint of heat resistance, dimensional stability, strength and the like of the monofilament of semi-aromatic polyamide. As the alicyclic dicarboxylic acid, one type may be used alone, or two or more types may be used in combination.

In addition, the cyclic dicarboxylic acid has geometric isomers of trans form and cis form. For example, 1,4-cyclohexanedicarboxylic acid as a raw material monomer may be used as either a trans form or a cis form, or may be used as a mixture of various ratios of the trans form and the cis form.

Examples of the linear or branched aliphatic dicarboxylic acid having 3 to 20 carbon atoms include malonic acid, dimethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylglutaric acid, and 2,2. -Diethylsuccinic acid, 2,3-diethylglutaric acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecane Examples thereof include, but are not limited to, diacid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosandioic acid, and diglycolic acid.

In general, when the number of aromatic rings contained in a dicarboxylic acid constituting a monofilament made of a semi-aromatic polyamide is increased, the binding force due to the interaction between aromatic rings between molecules is increased, and Tg is increased. Therefore, the aromatic ring contained in the dicarboxylic acid may be adjusted according to the required durability at high speed and steering stability. For example, the ratio of a dicarboxylic acid having one aromatic ring to an aromatic dicarboxylic acid is 20 mol% or more, and the ratio of a dicarboxylic acid having two aromatic rings to an aromatic dicarboxylic acid is 20 mol% or more. , And those in which the ratio of the dicarboxylic acid having three aromatic rings to the aromatic dicarboxylic acid is 20 mol% or more can be appropriately used. When the number of aromatic rings contained in the dicarboxylic acid increases, the melting point (Tm) also rises at the same time, so that the spinning workability of the fiber decreases, but the Tm can be lowered by increasing the number of carbon atoms of the diamine component. It is possible.

<Diamine>
The semi-aromatic polyamide monofilament according to the tire 10 of the present invention has a diamine ratio of 7 to 12 carbon atoms to diamine of 20 mol% or more from the viewpoint of spinning stability, heat resistance, and low water absorption. preferable. It is more preferably 30 mol% or more and 80 mol% or less, further preferably 40 mol% or more and 75 mol% or less, and particularly preferably 45 mol% or more and 70 mol% or less.

Generally, a polymer having a high Tg tends to have a high Tm. If the Tm is too high, the polyamide is thermally decomposed at the time of melting, the molecular weight and strength are lowered, coloring and decomposition gas are mixed, and the spinnability is deteriorated. However, by containing 20 mol% or more of diamine having 7 to 12 carbon atoms, it is possible to suppress the Tm to be suitable for melt spinning while maintaining a high Tg. Further, since the polyamide containing a diamine having 7 to 12 carbon atoms has high thermal stability at the time of melting, it is possible to obtain a monofilament having excellent spinning stability and good uniformity. Furthermore, by reducing the concentration of amide groups in the polyamide, it is possible to obtain a monofilament having excellent dimensional stability during water absorption. In particular, 1,9-nonanediamine and 1,10-decamethylenediamine are preferable from the viewpoint of achieving both spinning stability and strength.

The diamine other than 1,9-nonanediamine and 1,10-decamethylenediamine is not particularly limited, and even an unsubstituted linear aliphatic diamine is branched having a substituent such as an alkyl group having 1 to 4 carbon atoms. It may be an aliphatic diamine or an alicyclic diamine. Here, examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group and the like. Examples of diamines other than 1,9-nonandamine and 1,10-decamethylenediamine include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and undecamethylenediamine. , Dodecamethylenediamine, Linear aliphatic diamines such as tridecamethylenediamine, 2-methylpentamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2-methyloctamethylenediamine, 2,4-dimethyloctamethylenediamine , 1,4-Cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-cyclopentanediamine and the like.

Further, in the reinforcing cord according to the tire 10 of the present invention, an aromatic diamine may be added to the diamine as long as the fluidity of the polyamide is not impaired. The aromatic diamine is a diamine containing an aromatic, and examples thereof include, but are not limited to, metaxylylenediamine, orthoxylylenediamine, and paraxylylenediamine.

As the diamine other than 1,9-nonanediamine and 1,10-decamethylenediamine, it is more preferable that the diamine contains 5 to 6 carbon atoms and the ratio of the diamine having 5 to 6 carbon atoms is 20 mol% or more. By copolymerizing a diamine having 5 to 6 carbon atoms in addition to 1,9-nonanediamine and 1,10-decamethylenediamine, a polymer having high crystallinity can be obtained while maintaining an appropriate melting point suitable for spinning. be able to. Examples of the diamine having 5 to 6 carbon atoms include pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, 2,5-dimethylhexanediamine, 2,2,4-trimethylhexamethylenediamine and the like. ..

Among diamines having 5 to 6 carbon atoms, 2-methylpentamethylenediamine is preferable from the viewpoint of spinnability, fluidity and strength. If the ratio of 2-methylpentamethylenediamine is too high, 2-methylpentamethylenediamine self-cyclizes and decomposes at the time of melting, causing a decrease in molecular weight, resulting in deterioration of spinnability and strength. The ratio of 2-methylpentamethylenediamine in the diamine needs to be set within a range in which decomposition does not occur at the time of melting while ensuring fluidity, and is preferably 20 mol% or more and 70 mol% or less, more preferably 20 mol%. It is 60 mol% or more, more preferably 20 mol% or more and 55 mol% or less.

Among diamines having 5 to 6 carbon atoms, hexamethylenediamine is preferable from the viewpoint of heat resistance of the monofilament of the semi-aromatic polyamide according to the tire 10 of the present invention. If the ratio of hexamethylenediamine is too high, the melting point becomes too high and spinning becomes difficult. Therefore, the ratio of hexamethylenediamine in the diamine is preferably 20 mol% or more and 60 mol% or less, more preferably 20 mol% or more and 50 mol. % Or less, more preferably 20 mol% or more and 45 mol% or less.

The amount of the dicarboxylic acid added and the amount of the diamine added are preferably around the same mol amount in order to increase the molecular weight. Considering the amount of diamine escaping to the outside of the reaction system during the polymerization reaction in the mol ratio, the mol amount of the entire diamine is 0.99 to 1.20 with respect to the mol amount of 1.00 of the entire dicarboxylic acid. It is preferably 0.95 to 1.10, and even more preferably 0.98 to 1.05.

When polymerizing a polyamide from a dicarboxylic acid and a diamine, a known end-capping agent can be further added to control the molecular weight. Examples of the terminal encapsulant include acid anhydrides such as monocarboxylic acid, monoamine and phthalic anhydride, monoisocyanate, monoacid halides, monoesters and monoalcohols, and from the viewpoint of thermal stability. , Monocarboxylic acid, monoamine are preferable. The end sealant may be used alone or in combination of two or more.

<Polyamide manufacturing method>
Examples of the method for producing polyamide include (1) a method of heating an aqueous solution of a dicarboxylic acid / diamine salt or a mixture thereof or a suspension of water and polymerizing while maintaining the molten state (thermal melt polymerization method), (2). ) A method of increasing the degree of polymerization of the polyamide obtained by the hot melt polymerization method while maintaining the solid state at a temperature below the melting point (hot melt polymerization / solid phase polymerization method), (3) Diamine dicarboxylate or a mixture thereof. A method of heating an aqueous solution or a suspension of water and further melting the precipitated prepolymer with an extruder such as a kneader to increase the degree of polymerization (prepolymer / extrusion polymerization method), (4) diamine / dicarbonate. A method of heating a suspension of an aqueous solution or water of an acid salt or a mixture thereof to increase the degree of polymerization of the precipitated prepolymer while maintaining a solid state at a temperature below the melting point of polyamide (prepolymer / solid phase polymerization method). ), (5) A method of polymerizing a diamine dicarboxylate or a mixture thereof while maintaining a solid state (solid phase polymerization method), (6) Polymerization using a dicarboxylic acid halide component and a diamine component equivalent to dicarboxylic acid. Examples thereof include a method for causing the polymer (solution method).

As a method for producing a polyamide, (1) Fused Deposition Modeling Method or (2) Heat is used because it is easy to maintain the trans isomer ratio at 85% or less and the color tone of the obtained polyamide is excellent. It is preferable to produce the polyamide by the melt polymerization / solid phase polymerization method. The polymerization form may be a batch type or a continuous type. The polymerization apparatus is not particularly limited, and examples thereof include known apparatus such as an autoclave type reactor, a tumbler type reactor, and an extruder type reactor such as a kneader.

<Semi-aromatic polyamide monofilament>
The semi-aromatic polyamide monofilament according to the tire 10 of the present invention is a monofilament of the above-mentioned polyamide. The production of the monofilament of the semi-aromatic polyamide can be carried out by a known method. For example, a method of extruding a molten semi-aromatic polyamide from a molten spinning pack and spinning it can be mentioned. Regarding the manufacturing method by melt spinning, it can be manufactured by any method such as a method in which a spinning-drawing step is continuously performed (direct spinning and stretching method), a method in which an undrawn yarn is once wound and then drawn (two-step method). However, from the viewpoint of productivity, the direct spinning and drawing method is preferable.

For the semi-aromatic polyamide monofilament according to the tire 10 of the present invention, it is preferable to use an adhesive for adhering the rubber constituting the tire and the monofilament, and the adhesive is a resorcin-formalin-latex liquid. (RFL liquid) is preferable.

After adhering the RFL liquid, the RFL liquid is dried, fixed and relaxed. The drying temperature of the RFL liquid is preferably 120 to 250 ° C., more preferably 140 to 200 ° C., and the drying time is preferably 10 seconds or longer, more preferably 20 to 120 seconds. After drying, the twisted material is subsequently heat-treated in the heat set zone and the normalizing zone. The temperature and time in the heat set zone and the normalizing zone are preferably 150 to 250 ° C. and 10 to 300 seconds, respectively. At this time, stretching of 2% to 10% is performed, and it is preferable that stretching of 3% to 9% is performed.

The tire 10 of the present invention includes a belt 2 composed of at least one belt layer on the outer side of the carcass 1 in the radial direction of the tire, and at least one layer of a belt reinforcing layer 3 on the outer side in the radial direction of the tire of two belts. In the tire, at least one of the carcass 1 and the belt reinforcing layer 3 has a rubber-cord composite in which reinforcing cords arranged in parallel without twisting are embedded in rubber, and the reinforcing cords are formed. Particularly limited except that it contains a monofilament of a semi-aromatic polyamide consisting of a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine or a polycondensate of a diamine containing a non-aromatic dicarboxylic acid and an aromatic diamine. Instead, a known structure can be adopted. In the tire 10 of the present invention, at least one layer of the carcass ply or the belt reinforcing layer may be made of the rubber-cord composite, and the other layers may have a conventional configuration.

For example, in the example shown in FIG. 1, the carcass 1 is composed of one layer of carcass ply, but in the tire 10 of the present invention, the number of layers of the carcass ply is not limited to this, and two or more layers are used. There may be. Further, when a cord other than the above-mentioned cord made of a monofilament of semi-aromatic polyamide is used as the reinforcing cord of the carcass 1 and the belt reinforcing layer 3, a known organic fiber cord can be used, and the angle of the cord of the carcass is determined. The direction may be substantially orthogonal to the tire circumferential direction, for example, 70 to 90 °. As the organic fiber cord, a commonly used known one can be used. For example, nylon or polyethylene terephthalate (PET) cords can also be used. Further, the locking structure of the carcass ply in the bead portion is not limited to the structure in which the carcass ply is wound and locked around the bead core 4 as shown in the figure, and the end portion of the carcass ply may be sandwiched between two layers of bead cores. (Not shown).

Further, in the illustrated tire 10, the belt 2 is composed of two layers of belt layers 2a and 2b, but in the tire 10 of the present invention, the belt layer may be three or more layers. The belt layer can be, for example, a rubberized layer of a cord extending at an inclination of ± 15 to 40 ° with respect to the tire circumferential direction, preferably a rubberized layer of a metal cord such as steel. For example, the two belt layers 2a and 2b shown in the figure may be laminated so that the metal cords constituting the respective belt layers intersect each other with the tire equatorial plane E in between. The metal cord may be a metal cord in which a plurality of metal filaments are twisted together, or may be a metal cord in which a plurality of metal filaments are bundled without being twisted. Further, a plurality of metal filaments may be arranged in parallel without being twisted, and the metal filaments at that time may be straight or molded.

The form of the metal cord in which a plurality of metal filaments are arranged in parallel without twisting is preferably 2 or more, more preferably 5 or more, preferably 20 or less, and more preferably. Examples thereof include those in which metal filaments are arranged in parallel as a bundle of 12 or less, more preferably 10 or less, and particularly preferably 9 or less.

A rubber-metal composite having a metal cord in which a plurality of metal filaments are arranged in parallel without twisting or a bundled metal cord can be produced by a known method. For example, metal cords can be arranged in parallel at predetermined intervals, and the metal cords can be coated from both the upper and lower sides with a sheet made of an elastomer and having a thickness of about 0.5 mm. Further, the metal filament can be molded by a conventional method using a normal molding machine.

Further, in the tire 10 of the present invention, although not shown, an inner liner may be arranged in the innermost layer. In the tire 10 of the present invention, as the gas to be filled in the tire, normal or variable oxygen partial pressure air or an inert gas such as nitrogen can be used. The tire of the present invention is suitable for a passenger car tire.

10 Tires 1 Carcass 2 Belts 3 Belt Reinforcement Layer 4 Bead Core 5 Bead Filler
20,30 Rubber-cord composite 21,31 Monofilament 22 Bundle cord 23,33 Rubber

Claims (11)

In a tire having a belt composed of at least one belt layer on the outer side in the radial direction of the carcass tire and at least one layer of a belt reinforcing layer on the outer side in the radial direction of the tire of the belt.
At least one of the carcass and the belt reinforcing layer has a rubber-cord composite as a component, in which reinforcing cords arranged in parallel without twisting are embedded in rubber.
The reinforcing cord comprises a semi-aromatic polyamide monofilament composed of a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine or a polycondensate of a diamine containing a non-aromatic dicarboxylic acid and an aromatic diamine. A tire that features. The tire according to claim 1, wherein the semi-aromatic polyamide is a polycondensate of a dicarboxylic acid containing an aromatic dicarboxylic acid and a non-aromatic diamine. The tire according to claim 1 or 2, wherein the diamine is at least one of an aliphatic diamine and an alicyclic diamine. The tire according to any one of claims 1 to 3, wherein the diameter of the monofilament is 0.1 to 1.0 mm. The tire according to any one of claims 1 to 4, wherein the monofilament driving interval is 0.01 mm to 1.0 mm. The tire according to any one of claims 1 to 5, wherein the ratio of the aromatic dicarboxylic acid to the dicarboxylic acid of the monofilament is 50 mol% or more. The tire according to any one of claims 1 to 6, wherein the ratio of the dicarboxylic acid having one aromatic ring to the aromatic dicarboxylic acid is 20 mol% or more. The tire according to any one of claims 1 to 7, wherein the ratio of the dicarboxylic acid having two aromatic rings to the aromatic dicarboxylic acid is 20 mol% or more. The tire according to any one of claims 1 to 8, wherein the ratio of the dicarboxylic acid having three aromatic rings to the aromatic dicarboxylic acid is 20 mol% or more. The tire according to any one of claims 1 to 9, wherein the ratio of the diamine having 7 to 12 carbon atoms to the diamine is 20 mol% or more. The tire according to any one of claims 1 to 10, which is for a passenger car.

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