KR20180063924A - A Hybrid Dipped Cord Having Excellent Fatigue Resistance and Radial Tire Using the Same - Google Patents

Abstract

The present invention relates to a tire cord and a radial pneumatic tire. According to the present invention, when a raw cord, which is formed by twisting each of one set of polyethylene terephthalate yarns and one set of aramid yarns and combining the twisted yarns, is untwisted, the aramid yarns are supplied by 5 to 100 mm/m longer than the polyethylene terephthalate yarns. The hybrid dip cord according to the present invention has excellent fatigue resistance which is 80% or more, generates, in a tensile test, a low modulus by the nylon during initial deformation, and a high modulus from a section where aramid begins to receive strength, so the dip cord easily acts on deformation in the process of inflating a green tire inside a mold by using a bladder, thus a tire is easily manufactured.

Description

[0001] The present invention relates to a hybrid dipped cord having excellent fatigue resistance and a radial pneumatic tire using the same,

The present invention relates to a method for manufacturing a hybrid dipped cord having excellent fatigue resistance using polyethylene terephthalate yarn and aramid yarn, and a radial pneumatic tire to which the method is applied.

In recent years, the performance of tires has been continuously improved according to improvement of the road environment and the performance of the vehicle. Especially, as the weight of the vehicle increases and the limit speed increases, safety is more importantly considered as a quality factor of the tire. The safety standards of tires are also being changed in accordance with the increasing demand for safety of tires. Researches on methods for imparting safety of tires in the tire industry are also being actively conducted.

Generally, a tire cord is formed by twisting a yarn of the same kind to make a raw cord, dipping it in a dipping solution, and then heat-treating the same to form a dip cord. The hybrid cord is made of different kinds of yarns Is a code made by twisting two kinds of yarns in order to express the yarn.

On the other hand, in the step of imparting twist to the yarn, when the number of kinks is increased, the strength is lowered, the middle / consecutive is increased, and the fatigue is increasing. When the number of kinks is lowered, the strength is higher, . ≪ / RTI >

The twist is accomplished by a step (Ply) giving the lead to each yarn, followed by a step of twisting the yarns together. Leading the ply is to prevent double twisting during cabling.

In the case of producing the raw cord by twisting the same kind of yarn, it is common that the conditions of the inter-ply twist are the same, but in the case of the hybrid code, the properties of the raw code and further the dipped cord are adjusted .

In the hybrid cord, conventionally, there has been a method of giving twist numbers of different types of yarns differently to each other in the method of varying the twist conditions for the different types of yarns. That is, a fiber yarn having a high modulus and a low yarn endurance (for example, aramid yarn) gives less than the number of twisted yarns when the lower yarn is fed, and a yarn having a low modulus and a high yarn endurance (for example, nylon yarn) When the number of yarns is increased, since the yarn having a high modulus after staging is less than that of the upper yarn, twisting is imparted in the twisting direction of the upper yarn. However, since the yarns having a low modulus have the same upper and lower yarns, The initial modulus is lowered. However, such a technique can be applied only to a spinner (DRT, RT) to which a posterior edge is given, and can not be used in a direct barrel in which a vertical bar is simultaneously generated.

U.S. Patent No. 6601378

Disclosure of the Invention The present invention has been made to solve the problems of the prior art described above, and an object of the present invention is to provide a hybrid cord manufacturing method using a polyethylene terephthalate yarn and an aramid yarn, in a direct crawler A method of producing a raw cord having improved fatigue resistance by adding aramid yarn longer than polyethylene terephthalate yarn to produce a twisted yarn by applying a suitable twist to the twisted yarn, .

Another object of the present invention is to provide a method for manufacturing a carcass ply or a cap ply layer of an air inlet radial tire having a certain degree of fatigue, which is produced by dipping a raw cord using the polyethylene terephthalate yarn and aramid yarn in a dipping solution, And to provide a hybrid dip code.

According to a preferred embodiment of the present invention, the hybrid cord is made of a single cord of polyethylene terephthalate yarn and a single yarn of aramid yarn, 100 mm / m.

According to another preferred embodiment of the present invention, when the raw cord is melted, the aramid yarn is inserted in a length of 5 to 50 mm / m longer than that of the polyethylene terephthalate yarn.

According to another preferred embodiment of the present invention, the hybrid dip code is produced by dipping the raw cord into an adhesive liquid.

According to another preferred embodiment of the present invention, the fatigue resistance of the hybrid dip cord is 80% or more.

According to a preferred embodiment of the present invention, a method of manufacturing a hybrid dipped cord for a radial pneumatic tire comprises the steps of preparing a single polyethylene terephthalate yarn and a single aramid yarn; Adding the single aramid yarn longer than the polyethylene terephthalate yarn to produce a twisted yarn of 200 to 500 TPM yarns each to produce a lower yarn; Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And dipping the raw cord in a dipping solution followed by heat treatment to produce a dipped cord, wherein the aramid yarn is 5 to 100 mm / m longer than the polyethylene terephthalate yarn in the raw cord step.

According to another preferred embodiment of the present invention, the fineness of the polyethylene terephthalate yarn and the aramid yarn are respectively 500 to 3000 denier.

According to a preferred embodiment of the present invention, there is provided a belt comprising: a pair of parallel bead cores; at least one radial carcass layer wound around the bead cores; a belt layer laminated on the outer circumferential side of the carcass layer; Radial pneumatic tires comprising a belt reinforcing layer in the direction of the carcass ply include a hybrid dipped cord as shown above for a carcass ply or belt layer and may be used as one or two layers.

In the present invention, since the aramid yarn is inserted into the polyethylene terephthalate yarn for a long time, the strength is lowered and the mid / yarn height is increased, thereby causing an increase in fatigue resistance, so that the initial strain during the tensile test causes low modulus by the polyethylene terephthalate yarn And a high modulus can be generated from the section where aramid begins to receive the force. Therefore, when the green tire (tires) is blown into the bladder inside the mold at the time of vulcanization, It is easy to do. According to the present invention, it is possible to overcome the disadvantage of difficulty in deformation in a mold with high modulus when the aramid is used alone, and to improve the low fatigue resistance and adhesion which are problems in using aramid alone, Terephthalate or nylon 6 alone, it is possible to manufacture a high-performance tire by improving low modulus and heat resistance.

Fig. 1 is an example schematically showing a structure of a tire for a passenger car produced by using the hybrid dipped cord according to the present invention in a carcass layer or a cap ply layer.

Hereinafter, preferred embodiments of the present invention will be described in detail. The present invention is not limited to the scope of the present invention, but is merely an example, and various modifications can be made without departing from the technical gist of the present invention.

The method for producing a polyethylene terephthalate tire cord according to the present invention will be described in detail as follows.

First, a polyethylene terephthalate chip having an intrinsic viscosity of 1.0 to 1.15 is melted and extruded while passing through a nozzle to produce a discharged yarn. Here, the polyethylene terephthalate polymer may contain at least 85 mol% of ethylene terephthalate units, but may optionally contain only ethylene terephthalate units.

Optionally, the polyethylene terephthalate may comprise small amounts of units derived from ethylene glycol and terephthalenedicarboxylic acid or derivatives thereof and one or more ester-forming components in copolymer units. Examples of other ester forming components copolymerizable with the polyethylene terephthalate unit include glycols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and the like, and glycols such as terephthalic acid, isophthalic acid, hexahydroterephthalic acid, Dicarboxylic acids such as dicarboxylic acid, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid, dicarboxylic acid,

The terephthalic acid (TPA) and the ethylene glycol raw material are melt-mixed at a ratio of 2.0 to 2.3 to the polyethylene terephthalate chip thus prepared, and the molten mixture is transesterified and condensed to form a raw chip. Then, the low chip is subjected to solid phase polymerization so as to have an intrinsic viscosity of 1.0 to 1.15 at a temperature of 240 to 260 DEG C and a vacuum. If the intrinsic viscosity of the raw chips is less than 1.0, the intrinsic viscosity of the final drawn yarn is lowered and the processed cord after heat treatment can not exhibit high strength. If the intrinsic viscosity of the chips exceeds 1.15, the radiation tension is excessively increased, The cross section becomes nonuniform, and many filament cuts occur during stretching, resulting in poor workability in stretching.

Alternatively, an antimony compound, preferably antimony trioxide, may be added as a polymerization catalyst in the course of the condensation polymerization reaction so that the residual amount of antimony metal in the final polymer is 180 to 300 ppm. If the residual amount is less than 180 ppm, the polymerization reaction rate is slowed to lower the polymerization efficiency. If the residual amount exceeds 300 ppm, unnecessary antimony metal acts as a foreign substance and the radiation-drawing workability may be lowered. The polyethylene terephthalate chip is melted and extruded while passing through a nozzle to produce a discharged yarn. At this time, the diameter of the nozzle is preferably 1.1 to 1.4 mm.

Thereafter, the discharged yarn is quenched and solidified by passing through a cooling zone. At this time, if necessary, a heating device of a certain length is provided in a distance from the nozzle to the starting point of the cooling zone, that is, the length (L) of the hood. This zone is referred to as the delayed cooling zone or heating zone, which has a length of 50 to 250 mm and a temperature of 250 to 400 ° C (air contact surface temperature).

In the cooling zone, an open quenching method, a circular closed quenching method, a radial outflow quenching method, and a radial in flow quenching ) Method, but the present invention is not limited thereto.

At this time, the temperature of the cooling air injected for quenching in the cooling zone is adjusted to 20 to 50 캜. Such quenching using the sudden temperature difference between the hood and the cooling zone is intended to increase the solidification point and the radiation tension of the radiated polymer to increase the orientation of the undrawn yarn and the formation of the connection chain between the crystal and the crystal.

Thereafter, the solidified yarn passing through the cooling zone can be oiled at 0.5 to 1.2% by weight with respect to the discharged yarn by reducing the coefficient of friction between the tweezers and applying an emulsion applying apparatus having excellent stretchability and thermal efficiency.

And the oiled discharged yarn is radiated to form an unstretched yarn. In this case, the spinning draft is preferably 1500 to 1800, and the spinning speed is preferably 3,000 to 3,200 m / min. When spinning at the spinning draft and spinning speed in the above range, excellent strength of the yarn can be secured even at a low stretching ratio.

If the radiation draft is less than 1,500 or the spinning speed is less than 3,000 m / min, the uniformity of the cross section of the yarn is deteriorated to deteriorate the drawing workability and the degree of orientation of the unstretched yarn is decreased to degrade the crystallization degree. , The thermal stability is lowered, the strength of the tire cord is lowered, and the shape stability may be lowered when the high stretching is performed to improve the strength and modulus. When the breaking strength is higher than 3,200 m / min, The strength and elongation workability are deteriorated.

If the degree of orientation of the undrawn yarn is less than 0.06, the crystallinity and the denseness of the crystal can not be increased in the microstructure of the yarn. If the degree of orientation is less than 0.80, the drawability is deteriorated.

Thereafter, the non-drawn yarn is passed through a stretching roller to be multi-step stretched to produce a yarn. The yarn passed through the first stretching roller is stretched while passing through a series of stretching rollers by a spin draw method to form a yarn. In the drawing step, the non-drawn filaments may be multi-filament drawn, and the temperature of each of the drawn filaments is preferably higher than the glass transition temperature of the unstretched filament and lower than 95 캜, but the final filament roller temperature is preferably 200 to 250 캜. If the temperature of the last stretching roller is lower than 200 ° C, the crystallinity and the size of crystals do not increase in the stretching process, and the strength and thermal stability of the yarn are not exhibited, so that the morphological stability is deteriorated at high temperature. There is a problem that the microstructure of the yarn becomes uneven and the strength of the yarn is lowered. At this time, the winding speed of the drawn yarn is preferably 5,800 m / min or more. If the winding speed is less than 5,800 m / min, the productivity may be deteriorated.

Further, it is preferable that the total yarn m of the yarn formed by winding as described above is 2.14 to 2.22. When the stretching ratio is less than 2.14, the productivity is lowered and the strength of the yarn and the cord is lowered. When the stretching ratio exceeds 2.22, crystallization of the oriented non-gelling portion is increased, It is not preferable because the molecular chain of the noncrystalline chain is broken and the uniformity of the molecular chain is lowered and the strength utilization ratio may be lowered.

Hereinafter, the method for producing the aramid yarn used in the present invention will be described in detail.

The apparatus for producing an aramid fiber comprises a dope supply unit; Spinning detention; As a solidifying portion; Wherein the solidifying portion comprises: a coagulation bath located at a lower portion of the spinneret and containing a coagulating solution; A first coagulation tube positioned below the coagulation bath to provide a discharge passage for the coagulation liquid; An injection port attached to one side of the first coagulation tube at an angle of 20 to 40 degrees to inject a second coagulating solution; A second solidification tube attached to a lower end portion of the injection port; And the second solidification tube has a concavo-convex shape.

The dope containing the aromatic polyamide supplied from the dope supply portion is extruded through the spinneret and then solidified while passing through the solidifying portion to form the multifilament. The aromatic polyamide is a para-aramid having a high strength and a high modulus of elasticity, and is a polyparaphenylene terephthalamide (PPD-T), a poly (4,4'-benzanilide terephthalamide), a poly , 4'-biphenylene-dicarboxylic acid amide), poly (paraphenylene-2,6-naphthalene dicarboxylic acid amide), or a mixture of two or more thereof. The aromatic polyamide can be produced by the following method. First, an inorganic salt is added to an organic solvent to prepare a polymerization solvent. Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N, N'-dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA) Methyl urea (TMU), N, N-dimethylformamide (DMF) or mixtures thereof may be used. As the inorganic salt, CaCl2, LiCl, NaCl, KCl, LiBr, KBr, or a mixture thereof may be used. The inorganic salt is added in order to increase the polymerization degree of the aromatic polyamide. However, since the inorganic salt which is not dissolved when the inorganic salt is added in an excess amount may be present in the polymerization solvent, the content of the inorganic salt in the polymerization solvent is preferably 10% by weight or less. Since the solubility of the inorganic salt in the organic solvent is poor, water is added to completely dissolve the inorganic salt, and then the water is removed through a dehydration process, whereby a final polymerization solvent can be prepared.

Next, the aromatic diamine is dissolved in the polymerization solvent to prepare a mixed solution. The aromatic diamine may be para-phenylenediamine, 4,4'-diaminobiphenyl, 2,6-naphthalenediamine, 1,5-naphthalenediamine, or 4,4'-diaminobenzanilide. Then, a primary polymerization is carried out by adding a predetermined amount of aromatic diacid halide to the mixed solution while stirring the mixed solution. The aromatic diacid halide may be terephthaloyl dichloride, 4,4'-benzoyl dichloride, 2,6-naphthalene dicarboxylic acid dichloride, or 1,5-naphthalene dicarboxylic acid dichloride. Through the primary polymerization, a prepolymer is formed in the polymerization solvent. Subsequently, an aromatic diacid halide is further added to the above polymerization solvent to carry out a secondary polymerization, and through this secondary polymerization, an aromatic polyamide is finally obtained. The aromatic polyamide may be selected from the group consisting of polyparaphenylene terephthalamide (PPD-T), poly (4,4'-benzanilide terephthalamide), poly (paraphenylene- 4,4'-biphenylene-dicarboxylic acid amide), or poly (paraphenylene-2,6-naphthalene dicarboxylic acid amide).

Next, an alkaline compound such as NaOH, Li2CO3, CaCO3, LiH, CaH2, LiOH, Ca (OH) 2, Li2O, CaO or the like is added to the polymerization solution to neutralize the hydrochloric acid generated during the polymerization reaction. On the other hand, it may be advantageous to carry out the subsequent processes by adding water to the polymerization solution obtained through the primary and secondary polymerization processes to prepare a slurry state to improve its flowability. At this time, the neutralization step and the slurry production step may be performed simultaneously by adding water in which the alkali compound is dissolved to the polymerization solution.

Subsequently, the polymerization solvent is extracted from the polymerization solution. Such an extraction process is most effective and economical to perform using water. For example, a filter may be installed in a bath equipped with an outlet, and the polymer may be placed on the filter, and then water may be poured to discharge the polymerization solvent contained in the polymer together with water to the outlet. On the other hand, if the particle size of the aromatic polyamide present in the polymerization solution is too large, it takes a long time to extract the polymerization solvent and the productivity may be lowered. Therefore, the step of pulverizing the aromatic polyamide may be performed before the polymerization solvent extraction step.

Then, the water remaining in the aromatic polyamide is removed through dehydration and drying processes. The dope prepared by the above method is supplied to the spinneret through the dope supplying section and then extruded. The spinneret has a plurality of capillaries having a diameter of 0.1 mm or less. If the diameter of the capillary formed in the spinneret exceeds 0.1 mm, the molecular orientation of the resulting monofilament is deteriorated, resulting in a decrease in the strength of the multifilament. The concavo-convex shape is formed to promote the generation of turbulence, and the second coagulation tube has a cross-sectional area of 8 to 11 mm and a concavo-convex radius of 0.5 to 1.5 mm. The sum of the lengths of the first and second coagulation tubes is preferably 100 to 150 mm. When the sum of the lengths is less than 100 mm, the effect of irregularities is insufficient and uniform coagulation is not achieved. For example, if the length exceeds 150 mm, the pumping ability of the coagulation solution stored in the coagulation bath It can fall. The injection port is attached to one side of the first solidification tube, preferably at an angle of 20 to 40 degrees, preferably at an angle of 30 degrees. If it is attached outside the above-mentioned angle, that is, 20 to 40 degrees, the pumping ability to the coagulating solution becomes too slow, and high-speed spinning becomes impossible. The secondary coagulation solution injected through the injection port is manufactured so that the composition and temperature of the primary coagulation solution and the solvent are different. This is also intended to promote the generation of turbulence as in the case of the second coagulation tube of concavo-convex shape. The promotion of the generation of the turbulent flow can improve the extraction of the residual solvent, particularly sulfuric acid, and prevent the deterioration of the properties of the finally produced aramid fiber.

The properties of the aramid fiber may include elongation and tensile strength. Needless to say, however, the present invention is not limited thereto and includes all physical properties that can be measured by a person skilled in the art.

In the present invention, in the production of a hybrid cord using the polyethylene terephthalate yarn and the aramid yarn, a step of providing a cord to the cord as a pre-stage of the dip cord production (twisting process) is performed.

The polyethylene terephthalate yarn and the aramid yarn produced by the above method will be described in more detail. The yarn is wound by a direct twisted yarn in which twisted yarns and twin yarns are simultaneously wound, . The raw cord is manufactured by adding polyethylene terephthalate for tire cord and aramid yarn to a ply twist and then applying a cable twist. Generally, the upper and lower yarns are subjected to the same softening. In the twisting process, which is important in the present invention, the aramid yarn is injected at a rate of 5 to 100 mm / m longer than the polyethylene terephthalate yarn at the time of applying the bottom yarn for producing the raw cord.

A method for producing a hybrid dipped cord excellent in fatigue resistance according to the present invention comprises the steps of: preparing a single polyethylene terephthalate yarn and a single aramid yarn; Adding the single aramid yarn to the polyethylene terephthalate yarn in an amount of 5 to 100 mm / m longer to produce twisted yarns of 200 to 500 TPM; Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And dipping the raw cord in a dipping solution followed by heat treatment to produce a dipped cord; .

Generally, when the twist is high, the strength decreases, and the midline and the twist tend to increase. My fatigue also shows a tendency to improve with increasing kinks. The hybrid tire cord manufactured according to the present invention was manufactured at 200 to 500 TPM (twist per meter) at the same time. At this time, when the temperature is less than 200/200 TPM, the loss of the cord is reduced and the fatigue resistance tends to be lowered. When the pressure is higher than 500 TPM, the strength drop is large and is not suitable for tire cords.

The fineness of polyethylene terephthalate yarn and aramid yarn used for twisting yarns is preferably 500 to 3000 denier. Below 500 denier, the strength drop is very large at 500 TPM and above 3000 denier is not preferred because the fatigue is reduced at 200 TPM.

The hybrid cord according to the present invention is characterized in that the aramid yarn is inserted into the aramid yarn by 5 to 100 mm / m longer than that of the polyethylene terephthalate yarn. When the load is less than 5 mm, the fatigue is reduced and it is not appropriate. When the load exceeds 100 mm, the strength is decreased, which is not suitable. It is more preferable that the aramid yarn is inserted 5 to 50 mm / m longer than the polyethylene terephthalate yarn when the raw cord is melted, and 10 to 30 mm / m longer than that of the aramid yarn when the raw cord is melted Most preferred.

When the input amount of the aramid yarn having a high initial elongation and the low yarn end is high and the input amount of the polyethylene terephthalate yarn is short, the aramid yarn can be produced longer than the polyethylene terephthalate yarn.

In the manufacturing method according to the present invention, as the length of the aramid yarn is increased compared to that of the polyethylene terephthalate yarn, the strength is lowered and the middle / folding tendency is increased, and the fatigue resistance can be increased. Especially in this case, the initial strain in the tensile test causes low modulus by polyethylene terephthalate, and high modulus is expressed from the section where aramid begins to receive the force.

 Conversely, the shorter the aramid yarn input (longer than the polyethylene terephthalate yarn, but shorter the length of the aramid yarn), the higher the strength, and the lower / middle yarn and fatigue tend to decrease.

The manufactured 'Raw Cord' is woven using a weaving machine, and the obtained fabric is immersed and cured in the dipping solution to form a 'cord' Dip cord ".

The dipping process of the present invention will be described in more detail. Dipping is accomplished by impregnating the surface of the fiber with a resin layer called RFL (Resorcinol Formalin-Latex). The disadvantage of the fiber for tire cords, .

In the case of using polyethylene terephthalate or polyethylene naphthalate fiber, since the reactor on the surface of the fiber is smaller than that of rayon fiber or nylon fiber, polyethylene terephthalate or polyethylene naphthalate The surface of the phthalate is activated first, followed by an adhesion treatment (2 bath dipping).

In the present invention, an adhesive liquid for bonding a hybrid cord and rubber can be manufactured by the following method. It is to be understood that the following examples are intended only for a better understanding of the present invention and are not intended to limit the scope of the present invention.

29.4 wt% resorcinol 45.6 parts by weight; 255.5 parts by weight of distilled water; 37% formalin 20 parts by weight; And 3.8 parts by weight of 10 wt% sodium hydroxide were prepared and reacted at 25 DEG C for 5 hours with stirring.

 Next, 300 parts by weight of 40% by weight of VP-latex, 129 parts by weight of distilled water and 23.8 parts by weight of 28% ammonia water were added and aged at 25 DEG C for 20 hours to maintain a solid concentration of 19.05%.

A stretch of 0 to 3% is required to adjust the adhesion amount of the adhesive liquid, and preferably 1 to 2% of the elongation can be achieved. If the elongation percentage is too high, the adhesion amount of the adhesive liquid can be adjusted but the yield is reduced and the fatigue resistance is reduced as a result. On the other hand, if the elongation percentage is too low, for example, if it is lowered to less than 0%, there is a problem that it is impossible to control the DPU by penetrating the dipping solution into the cord.

The adhesion amount of the adhesive is preferably 2 to 7% based on the weight of the fibers on a solid basis. After passing through the adhesive solution, the hybrid dip cords are dried at 120-180 占 폚. Dried for 180 seconds to 220 seconds, and dried in a state where the hybrid dipped cord is stretched to about 1 to 2% in the drying process. If the elongation ratio is low, the cords and the cord of the cord increase, which may result in a property that is difficult to apply to the tire cord. On the other hand, if the elongation ratio is more than 3%, the level of the medium is adequate but the turnover may be too small to reduce the fatigue resistance.

After drying, heat treatment is performed at a temperature range of 130 to 260 ° C. The elongation ratio during the heat treatment is maintained between -2 and 3%, and the heat treatment time is suitably between 50 and 90 seconds. If the heat treatment is performed for less than 50 seconds, the reaction time of the adhesive solution is insufficient and the adhesive force is lowered. If the heat treatment is performed for more than 90 seconds, the hardness of the adhesive solution becomes high and the fatigue resistance of the cord may be decreased have.

The hybrid dipped cord produced according to the above-described method is characterized in that its fatigue resistance is 80% or more. When the fatigue strength is less than 80%, the durability of the tire is reduced, which is not preferable.

The hybrid dipped cord manufactured through such a process is used for the manufacture of tires for passenger cars. When the aramid yarn is used solely for blasting the green tire inside the mold during vulcanization, Deformation can be easily performed as compared with the case where there is a difficulty in deformation, so that it is used for easy manufacture of a tire. The hybrid dipped cord manufactured through such a process is applied to a tire for a passenger car. It is mainly applied to a cap fly and a carcass ply to improve low fatigue resistance and adhesion, which is a problem when aramid yarn is used alone, and polyethylene terephthalate Is used to manufacture high performance tires with excellent fatigue resistance by improving the low modulus and heat resistance which are problematic when used alone.

1 shows a structure of a tire for a passenger car in which a hybrid dipped cord according to the present invention is applied as a carcass ply or a cap ply.

1, the bead region 35 of the tire 31 becomes an annular bead core 36 which is non-stretchable. The bead core 36 is preferably made of a single or single filament wire wound continuously. In a preferred embodiment, a high strength steel wire having a diameter of 0.95 mm to 1.00 mm forms a 4x4 structure and a 4x5 structure.

In an embodiment of the tire cord according to the present invention the bead region 35 may have a bead filler 37 and the bead filler 37 should have a hardness above a certain level and preferably a Shore A hardness 40 Or more.

According to the present invention, the tire 31 can be reinforced by the belt 38 and the cap ply 39. The belt 38 comprises a cut belt ply 40 consisting of two cords 41 and 42 and the cord 41 of the belt ply 40 is oriented at an angle of about 20 degrees with respect to the circumferential center plane of the tire. . One cord 41 of the belt ply 40 may be disposed opposite the direction of the cord 42 of the other belt ply 40 in a direction opposite the circumferential center plane. However, the belt 38 may comprise any number of plys, and may preferably be located in the range of 16 to 24 degrees. The belt 38 serves to provide lateral stiffness to minimize the rise of the tread 33 from the road surface during operation of the tire 31. The cords 41 and 42 of the belt 38 may be made of steel cords and have a 2 + 2 structure, but may be made of any structure. The cap ply 39 and the edge ply 44 are reinforced on the upper portion of the belt 38 so that the cord 45 of the cap ply 39 is reinforced in parallel with the circumferential direction of the tire, And the cord 45 of the cap ply 39 having a large heat-shrinking stress at a high temperature is used. The cord 45 of the cap ply 39 may be manufactured using a hybrid dipped cord made of polyethylene terephthalate yarn produced according to the method of the present invention and aramid yarn. One layer of cap ply 39 and one layer of edge ply 44 may be used, and preferably one or two layers of cap ply and one or two layers of edge ply may be reinforced.

Reference numerals 32 and 34, which are not described in FIG. 2, denote the carcass layer 32 and the fly-turn 34. And reference numeral 33 denotes a carcass layer reinforcing cord 33. [

Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples. However, the present invention is not intended to limit the scope of the present invention. In the following Examples and Comparative Examples, the properties of the hybrid dip cords were evaluated by the following methods.

(a) Hybrid dip cord strength (kgf) and moderate elongation (%)

Dried at 107 DEG C for 2 hours, and then measured at a sample length of 250 mm and a tensile speed of 300 m / min using a low-speed stretching type tester manufactured by Instron. The elongation at specific load was measured at a load of 4.5 kg.

(b) Dry Heat Shrinkage (%, Shrinkage)

The ratio of the length (L0) measured at a constant load of 0.05 g / d and the length (L1) after treatment at a constant load of 0.05 g / d for 30 minutes at 150 ° C To show dry heat shrinkage ratio.

S (%) = (L0 - L1) / L0 100

(c) hybrid dip code E-S value

The term "elongation under a constant load" is referred to as "elongation (E)" in the present invention. "S" means the dry heat shrinkage rate in the above (b), and the sum of the elongation at break (E) Respectively.

E-S = moderate elongation (%) + dry heat shrinkage (%)

(d) My fatigue

The residual fatigue strength was measured by using a Belt Fatigue Tester, which is commonly used for fatigue test of tire cords, and fatigue resistance was compared. The fatigue test conditions were normal temperature, load of 80 kg, and repeated 37,500 times. After the fatigue test, the rubber and cord were separated and the residual strength was measured. The residual strength was measured according to the above method (a) using a normal tensile strength tester.

Example 1

Polyethylene terephthalate and aramid fibers were respectively obtained according to the above-described method for producing tire reinforcing fibers. One 1000 t of polyethylene terephthalate yarn (1000 D) and one aramid yarn (1000 D) were each twisted with 400 TPM, and the yarn was folded to give a twist of 400 TPM. At this time, the aramid yarn was inserted 10 mm / m longer than the polyethylene terephthalate yarn. And then passed through an adhesive liquid prepared by the following method to give an adhesive liquid. A 2% stretch was applied during drying to prevent unevenness of raw cord due to heat shrinkage.

29.4 wt% resorcinol 45.6 parts by weight; 255.5 parts by weight of distilled water; 37% formalin 20 parts by weight; And 3.8 parts by weight of 10 wt% sodium hydroxide were prepared and reacted with stirring at 25 DEG C for 5 hours, and the following components were added: 300 parts by weight of 40 wt% VP-latex, 129 parts by weight of distilled water, 28% 23.8 parts by weight After the components were added, the mixture was aged at 25 DEG C for 20 hours to maintain the solid content concentration at 19.05%. The adhesive solution was applied and dried at 150 캜 for 2 minutes and then subjected to heat treatment at 170 캜 for 60 seconds to evaluate the physical properties of the prepared hybrid dip cords,

Example 2

A hybrid dipped cord was prepared in the same manner as in Example 1 except that the length of the aramid yarn was 20 mm / m longer than that of the polyethylene terephthalate yarn at the time of providing the bottom yarn at the twisting stage in the production of the raw cord. And the results are shown in Table 1. < tb > < TABLE >

Example 3

A hybrid dipped cord was prepared in the same manner as in Example 1 except that the length of the aramid yarn was 30 mm / m longer than that of the polyethylene terephthalate yarn at the time of providing the bottom yarn at the twisting stage in the production of the raw cord. And the results are shown in Table 1. < tb > < TABLE >

Example 4

An experiment was conducted in the same manner as in Example 1 except that the length of the aramid yarn was 40 mm / m longer than that of the polyethylene terephthalate yarn at the time of providing the bottom yarn at the twisting stage in the production of raw cord, . The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

Comparative Example 1

In the twisting process for the production of raw cord, one aramid yarn (1000D) was subjected to a lead of 40 TPM, and then one aramid yarn (1000D) to which the leading yarn was applied and one polyethylene A hybrid dipped cord was prepared in the same manner as in Example 1, except that aramid yarn and polyethylene terephthalate yarn were fed in the same length while twisting yarns of 400 TPM each of terephthalate yarn (1000D) were manufactured and joined together . The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

Comparative Example 2

In the twisting process for the production of raw cord, one twisted polyethylene terephthalate yarn (1000D) and an aramid yarn (1000D) were each twisted with a twist of 400 TPM to produce a twisted yarn, and aramid yarn and polyethylene terephthalate yarn To prepare a hybrid dip cord in the same manner as in Example 1. The properties of the dipped cords prepared as described above were evaluated and are shown in Table 1.

Processing Code Properties
Remarks Power (kg) Intermediate stretch
4.5kg (%) Shrinkage (%) ES value (%) My fatigue (%) Example 1 25.3 2.5 0.8 3.3 85.4 Example 2 25.0 2.7 0.8 3.5 87.1 Example 3 24.9 2.8 0.8 3.5 89.3 Example 4 24.6 3.0 0.8 3.5 91.5 Comparative Example 1 22.5 2.8 0.9 3.7 71.1 My fatigue is low Comparative Example 2 25.5 2.4 0.8 3.2 69.2 My fatigue is low

From the results of the tests in Table 1, it can be seen that the fatigue resistance of the hybrid dipped cord according to the present invention is improved as compared with the comparative example.

Example 5

A radial tire manufactured using the hybrid dipped cord produced by Example 1 of the present invention as a cap ply has a carcass layer having a radially outer side fly-turn, and the carcass layer is provided so as to include one layer. At this time, the specifications of the carcass cords were as shown in the following Table 2 and aligned at an angle of 90 degrees with respect to the circumferential intermediate surface of the tire. The fly-turn 34 has a height of 40 to 80% with respect to the maximum cross-sectional height of the tire. The bead portion 35 has a bead core 36 having a high strength steel wire 4 having a diameter of 0.95 to 1.00 mm and a bead filler 37 having a shore hardness of 40 or more. The belt 38 is reinforced by a belt reinforcing layer consisting of one layer of cap ply 39 and one layer of edge ply 44 at the top so that the cap ply cords in the cap ply 39 are parallel to the circumferential direction of the tire Respectively.

Example 6

A tire was prepared in the same manner as in Example 5, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Example 2. [

Example 7

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Example 3.

Example 8

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Example 4.

Comparative Example 3

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was a dip cord manufactured by Comparative Example 1.

Comparative Example 4

A tire was produced in the same manner as in Example 5, except that the cord material for tire production was a dip cord manufactured by Comparative Example 2.

Example 5 Example 6 Example 7 Example 8 Comparative Example 3 Comparative Example 4 Kakas Material Polyethylene
Terephthalate Polyethylene
Terephthalate Polyethylene
Terephthalate Polyethylene
Terephthalate Polyethylene
Terephthalate Polyethylene
Terephthalate Specification (d / summing speaker) 1500d / 2 1500d / 2 1500d / 2 1500d / 2 1500d / 2 1500d / 2 Strong (Kg) 24 24 24 24 24 24 Modulus of elasticity (g / d) 60 60 60 60 60 60 Cap fly Material The hybrid dip code of Example 1 Example 2
Hybrid dip code Example 3
Hybrid dip code Example 4
Hybrid dip code The hybrid dip code of Comparative Example 1 Comparative Example 2
Hybrid dip code tire Flat rate 0.60 0.60 0.60 0.60 0.60 0.60 Number of carcass layers One One One One One One Cap fly layer number One One One One One One

Example 9

A radial tire produced by using the hybrid dipped cord manufactured by Example 1 of the present invention in a carcass layer has a carcass layer having a radially outer fly-up, and the carcass layer is installed so as to include one layer Respectively. At this time, specifications of the cap fly and carcass cord were as shown in the following Table 3, and tires were produced in the same manner as in Example 5.

Example 10

Tires were produced in the same manner as in Example 5, except that the cord material for making tires was a hybrid dipped cord prepared in accordance with Example 2.

Example 11

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Example 3.

Example 12

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Example 4.

Comparative Example 5

A tire was produced in the same manner as in Example 5, except that the cord material for tire fabrication was a dip cord manufactured by Comparative Example 1.

Comparative Example 6

A tire was produced in the same manner as in Example 5, except that the cord material for tire production was a dip cord manufactured by Comparative Example 2.

Example 9 Example 10 Example 11 Example 12 Comparative Example 5 Comparative Example 6 Kakas Material The hybrid dip code of Example 1 Example 2
Hybrid dip code Example 3
Hybrid dip code Example 4
Hybrid dip code The hybrid dip code of Comparative Example 1 Comparative Example 2
Hybrid dip code Cap fly Material Nylon 6,6 Nylon 6,6 Nylon 6,6 Nylon 6,6 Nylon 6,6 Nylon 6,6 Specification (d / summing speaker) 1260d / 2 1260d / 2 1260d / 2 1260d / 2 1260d / 2 1260d / 2 Power (kg) 24 24 24 24 24 24 Modulus of elasticity
(g / d) 50 60 60 60 60 60 tire Flat rate 0.60 0.60 0.60 0.60 0.60 0.60 Number of carcass layers One One One One One One Cap fly layer number One One One One One One

The 205/65 R15 V tire manufactured according to Examples 5, 6, 7, 8, 9, 10, 11, 12 and Comparative Examples 3, 4, 5 and 6 was mounted on a 2000cc class passenger car, (DB) in the audible frequency range, and the stability and ride quality of the vehicle are measured by a skilled driver on a test course and evaluated in units of 5 points on a scale of 100 And the results are shown in Table 4 below. The durability was measured in accordance with FMVSS 109 P-metric tire endurance test method at a measurement temperature of 38 ° C (° C), 85, 90, 100% (OK) when no traces of bead separation, cord cutting, belt separation, etc. were found in any part of the tread, sidewall, carcass cord, inner liner, bead or the like.

division Tire weight
(kg) Ride comfort Steering stability durability Uniformity Noise (dB) Example 5 9.98 100 100 OK 100 60.4 Example 6 9.98 100 100 OK 100 60.4 Example 7 9.99 100 100 OK 100 60.5 Example 8 10.02 100 100 OK 100 61.2 Comparative Example 3 10.01 97 96 OK 92 62 Comparative Example 4 10.08 94 95 OK 93 62.1 Example 9 10.2 100 100 OK 100 60.4 Example 10 10.2 100 100 OK 100 60.3 Example 11 10.12 100 100 OK 100 60.4 Example 12 10.0 100 100 OK 100 60.6 Comparative Example 5 10.5 95 97 OK 94 61.5 Comparative Example 6 10.6 95 94 OK 93 63

The results of the tests of Table 4 show that the tires using the hybrid cord according to the present invention (Examples 5 to 12) were more effective in noise reduction and steering stability than the Comparative Examples 3 to 6, Te is also improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above teachings. will be.

31: Tire 32: Carcass layer
33: Carcass layer reinforcement cord 34: Fly turn-up
35: bead region 36: bead core
37: bead filler 38: belt structure
39: cap fly 40: belt fly
41, 42: belt cord 43: tread
44: edge fly 45: cap fly cord

Claims (9)

A hybrid tire cord for a radial pneumatic tire,
Wherein the aramid yarn has a length of 5 to 100 mm / m longer than that of the polyethylene terephthalate yarn when one raw yarn cord of the single yarn of the polyethylene terephthalate yarn and one yarn of the aramid yarn is combined, . The method according to claim 1,
Wherein the aramid yarn is inserted into the yarn of 5 to 50 mm / m longer than that of the polyethylene terephthalate yarn. The method according to claim 1,
Wherein the aramid yarn is 10 to 30 mm / m longer than the polyethylene terephthalate yarn when the raw cord is finished. A hybrid dip cord produced by dipping the raw cord of claim 1 into an adhesive liquid. 5. The method of claim 4,
Hybrid Deep Cord with fatigue of 80% or more. A pair of parallel bead cores, at least one radial carcass layer wound around the bead cores, a belt layer laminated on the outer circumferential side of the carcass layer, and a radial air layer including a circumferential belt reinforcing layer formed on the outer circumferential side of the belt layer In the mouth tires,
Wherein the carcass layer comprises the hybrid dipped cord according to any one of claims 4 to 5, wherein the carcass layer is used as one or two layers. A pair of parallel bead cores, at least one radial carcass layer wound around the bead cores, a belt layer laminated on the outer circumferential side of the carcass layer, and a radial air layer including a circumferential belt reinforcing layer formed on the outer circumferential side of the belt layer In the mouth tires,
Wherein the cap reinforcing layer comprises a hybrid dipped cord according to any one of claims 4 to 5, wherein the cap ply is used as one or two layers. A method of manufacturing a hybrid dipped cord for a radial pneumatic tire,
Preparing one polyethylene terephthalate yarn and one aramid yarn;
Adding the single aramid yarn longer than the polyethylene terephthalate yarn to produce a twisted yarn of 200 to 500 TPM yarns each to produce a lower yarn;
Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And
Immersing the raw cord in a dipping solution, and then heat-treating the raw cord to produce a dipped cord; Wherein the aramid yarn is 5 to 100 mm / m longer than the polyethylene terephthalate yarn when the yarn is formed in the raw cord step. 9. The method of claim 8,
Wherein the fineness of the polyethylene terephthalate yarn and the aramid yarn is 500 to 3000 denier, respectively.

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