KR101838490B1 - A High Tenacity Tire Cord using Polyethyleneterephthalate and Aramid, and Radial Tires Produced by the Same - Google Patents

Abstract

The present invention relates to a high tenacity hybrid dip cord using polyethylene terephthalate yarn and aramid yarn, and a radial pneumatic tire using the same. According to the present invention, a method for producing the hybrid dip cord comprises the following steps: preparing one polyethylene terephthalate yarn and one aramid yarn; adding one of the polyethylene terephthalate yarn longer than the aramid yarn to produce primarily twisted yarn by imparting twist of 200 to 500 twist per meter (TPM); folding the primarily twisted yarn in two to produce a raw cord by imparting twist of 200 to 500 TPM; and thermally treating the raw cord by dipping the raw cord into an adhesive liquid, wherein the polyethylene terephthalate yarn is thermally shrunk so that the polyethylene terephthalate yarn has the same length as the aramid yarn.

Description

TECHNICAL FIELD [0001] The present invention relates to a high tenacity tire cord made of polyethylene terephthalate yarn and aramid yarn, and a radial pneumatic tire using the same. More particularly, the present invention relates to a high tenacity tire cord made of polyethyleneterephthalate

The present invention relates to a high strength tire cord using polyethylene terephthalate yarn and aramid yarn, and a radial pneumatic tire using the same.

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 imparting different twist numbers to the twist yarns in the different yarn conditions for different yarn 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.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method for producing a polyethylene terephthalate yarn and an aramid yarn by appropriately twisting the polyethylene terephthalate yarn and the aramid yarn, The present invention provides a high-strength hybrid dip cord for a radial pneumatic tire having a length equal to that of a polyethylene terephthalate yarn and an aramid yarn, and a method for manufacturing the same.

Another object of the present invention is to provide a hybrid dip cord for a carcass ply or cap ply layer of an air inlet radial tire having a high initial modulus value by thermally shrinking the polyethylene terephthalate yarn to make it equal in length to the aramid yarn.

According to a preferred embodiment of the present invention, the hybrid dipped cord of the present invention comprises a polyethylene terephthalate yarn and a single aramid yarn, respectively, And the polyethylene terephthalate yarn is thermally shrunk by heat treatment so that the length of the polyethylene terephthalate and the aramid yarn becomes equal when the dipped cord formed by heat treatment of the raw cord is melted.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is characterized in that the polyethylene terephthalate yarn is shrunk by adjusting the tension or adjusting the temperature during the heat treatment of the raw cord.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is characterized in that when the raw cord is melted, polyethylene terephthalate yarn is inserted into the aramid yarn by 7 to 50 mm / m longer than that of the aramid yarn.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is characterized in that when the raw cord is melted, the polyethylene terephthalate yarn is inserted 10 to 30 mm / m longer than the aramid yarn.

According to another preferred embodiment of the present invention, the hybrid dip cord of the present invention is characterized by having a strength of 25.5 kg or more and an intermediate elongation of 2.0% or less.

According to a preferred embodiment of the present invention, a method for producing a hybrid dipped cord of the present invention comprises: preparing a single polyethylene terephthalate yarn and a single aramid yarn; Adding one polyethylene terephthalate yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM, respectively; Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And a step of dipping the raw cord into an adhesive liquid and performing heat treatment. In the step of preparing the bottom yarn, a single polyethylene terephthalate yarn is inserted into the single aramid yarn by 5 to 100 mm / m, And the polyethylene terephthalate yarn is thermally shrunk so that the polyethylene terephthalate yarn becomes the same as the aramid yarn during the heat treatment.

According to another preferred embodiment of the present invention, the method for producing the hybrid dipped cord of the present invention is characterized in that the fineness of the polyethylene terephthalate yarn and the aramid yarn are respectively 500 to 3000 denier.

According to another 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; Wherein the cap ply and carcass layers as the belt reinforcing layers comprise a hybrid dipped cord according to the invention and the cap ply or carcass layer comprises one or two layers Is used.

The hybrid dipped cord of the present invention can make the polyethylene terephthalate yarn and the aramid yarn have the same breaking times by making the length of the polyethylene terephthalate yarn having a high elongation equal to that of the aramid yarn having a high initial modulus even after heat shrinking, Can be improved.

According to the present invention, a hybrid dipped cord made of polyethylene terephthalate yarn of the present invention and aramid yarn of the present invention is applied to a carcass ply and a cap ply (belt reinforcement) of air inlet radial tires of a passenger car to improve noise reduction and steering stability Satisfactory results can be obtained.

Fig. 1 schematically shows a spinning and drawing process of a polyethylene terephthalate yarn according to the present invention.
Fig. 2 schematically shows a manufacturing process of an aramid yarn according to the present invention.
Fig. 3 schematically shows 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 polyethylene terephthalate yarn and the aramid yarn for the production of the hybrid dipped cord according to the present invention are produced through the following process.

First, as a preliminary step for producing a hybrid cord, a process for producing a polyethylene terephthalate fiber will be described.

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, a method for producing the aramid yarn used in the present invention will be described in detail with reference to the accompanying drawings.

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, And a step of giving a cord to the cord as a pre-stage of dip code production (a twisting process).

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, polyethylene terephthalate yarn is supplied longer than aramid yarn using a point that polyethylene terephthalate yarn is heat-shrunk by heat treatment at the time of applying bottom yarn for producing a raw 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.

A method for manufacturing a hybrid dipped cord according to the present invention comprises the steps of: preparing a single polyethylene terephthalate yarn and a single aramid yarn; Adding one polyethylene terephthalate yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM, respectively; Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And a step of dipping the raw cord into an adhesive liquid and performing heat treatment. In the step of preparing the bottom yarn, a single polyethylene terephthalate yarn is inserted into the single aramid yarn by 5 to 100 mm / m, And heat-shrinking the polyethylene terephthalate to heat shrink such that the length of the polyethylene terephthalate is equal to the length of the aramid yarn.

In the present invention, one twisted polyethylene terephthalate yarn and one aramid yarn are twisted to produce a twisted yarn, and one twisted polyethylene terephthalate yarn is inserted into the twin yarn of aramid yarn at a rate of 5 to 100 mm / m And controlling the tensile strength or temperature so that the polyethylene terephthalate yarn is thermally shrunk to the same length as the aramid yarn during the heat treatment.

That is, the polyethylene terephthalate yarn having a high dry heat shrinkage ratio is 3 to 6% heat shrinkable by heat treatment, whereas the aramid yarn having a low dry heat shrinkage hardly undergoes heat shrinkage even after the heat treatment. Therefore, the degree of heat shrinkage of the polyethylene terephthalate yarn and the degree of heat shrinkage of the aramid yarn Considering the difference in length, polyethylene terephthalate yarn is added to the aramid yarn to produce a raw cord, and when the raw cord is heat-treated, the polyethylene terephthalate yarn having a high elongation due to the adjustment of the tension and the temperature, The aramid yarn and the polyethylene terephthalate yarn can be made to have the same breaking timing, and the strength and initial modulus of the hybrid dipped cord can be advantageously improved.

If the polyethylene terephthalate yarn is not added for a longer period of time in the step of preparing the lower yarn, the polyethylene terephthalate yarn is thermally shrunk during the heat treatment to be shorter than the aramid yarn, and the polyethylene terephthalate yarn having a low modulus There is a problem that the strength of the cord is lowered.

Methods for heat shrinking polyethylene terephthalate yarn include a tension control method and a temperature control method. The tension adjustment is performed by a speed difference between the feed roller and the take-up roller, but is not limited thereto. The temperature control method can be adjusted at 130 to 240 캜. Both methods involve adjusting the heat treatment time, which can be adjusted in 50 seconds to 5 minutes. The degree of shrinkage of polyethylene terephthalate can vary depending on the heat treatment conditions.

The extent to which the polyethylene terephthalate yarn is inserted longer than the aramid yarn is related to the degree of heat shrinkage. More preferably 5 to 100 mm / m, more preferably 7 to 50 mm / m. When the amount is less than 5 mm / m, the fatigue resistance is decreased, which is not preferable as a tire cord. When the tire is supplied at a load of more than 100 mm / m, strength is not ensured. According to one embodiment of the present invention, it is most preferable to add 10 to 30 mm / m more.

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, the surface of the polyethylene terephthalate is first exposed to the surface of the fiber because the reactor on the surface of the fiber is smaller than that of the rayon fiber or the nylon fiber After activation, the adhesive treatment is performed (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.

Particularly, in the present invention, the polyethylene terephthalate is inserted longer than the aramid yarn in the raw cord step, but the polyethylene terephthalate is heat-shrunk by controlling the tension or adjusting the temperature in the heat treatment step so as to have the same length as the aramid yarn This is one of the characteristics of

The present invention mainly describes the case of performing dipping using a two-bath dipping machine, but it is also possible to perform heat treatment under the same conditions using a single-bath dipping machine as long as a person skilled in the art is familiar.

The hybrid dipped cord produced according to the above-described method is characterized by having a strength of 25.5 kg or more and an intermediate elongation of 2.0% or less. When the strength is less than 25.5 kg, the stability of handling is reduced when the tire is manufactured, and when the intermediate elongation is more than 2.0%, the noise is increased when the tire is manufactured.

The hybrid dipped cord produced through such a process is applied as a carcass ply and a cap ply and is used for manufacturing tires for passenger cars.

Fig. 3 shows the structure of a tire for a passenger car in which the hybrid dipped cord according to the present invention is applied as a carcass ply or a cap ply.

Referring to Fig. 3, the bead region 35 of the tire 31 becomes an annular bead core 36 that 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 hybrid dipped cords made of lyocell yarns and para-aramid yarns. 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. [

Embodiments and comparative examples which do not limit the scope of the present invention are described below. 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 40 ℃, 70kg of load and 34.58% of compression. After the fatigue test, the rubber was immersed in tetrachlorethylene solution for 24 hours to swell the rubber, and then the rubber and cord were separated and the residual strength was measured. The residual strength was measured by a conventional tensile strength tester after drying at 107 占 폚 for 2 hours in accordance with the above method (a).

[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 polyethylene terephthalate yarn was inserted 10 mm / m longer than the aramid 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% ammonia water, 23.8 parts by weight After the components were added, they were aged at 25 캜 for 20 hours to maintain a solid content concentration of 19.05%.

After the adhesive liquid was applied and dried at 150 ° C for 2 minutes, the polyethylene terephthalate yarn was shrunk by heat treatment at 240 ° C for 60 seconds while stretching to make the length of the shrinkage equal to that of the aramid yarn, and the adhesive treatment was terminated. The physical properties of the thus prepared hybrid dip cords were evaluated and shown in Table 1

[Example 2]

The raw cord and the dip cord were prepared in the same manner as in Example 1, except that polyethylene terephthalate yarn was fed at a rate of 20 mm / m. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Example 3]

The raw cord and dip cord were prepared in the same manner as in Example 1, except that the polyethylene terephthalate yarn was fed 30 mm / m longer. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Example 4]

The raw cord and the dip cord were prepared in the same manner as in Example 1, except that the polyethylene terephthalate yarn was fed 40 mm / m longer. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

Comparative Example 1

In the twisting process for producing a raw cord, one aramid yarn (1000D) was subjected to 40 TPM leading yarn, and then one aramid yarn (1260D) to which the leading yarn was given and one polyethylene A hybrid dipped cord was prepared in the same manner as in Example 1, except that polyethylene terephthalate yarn and aramid yarn were fed at the same length while twisted yarn of 400 TPM was added to terephthalate yarn (1000D), respectively, . 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, polyethylene terephthalate yarn (1000D) and aramid yarn (1500D) were each twisted at 400 TPM to produce a twisted yarn, and polyethylene terephthalate yarn and aramid 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.

division Processing Code Properties Remarks strong
(kg) Intermediate stretch
4.5kg (%) Shrinkage rate
(%) ES value
(%) My Fatigue
(%) Example 1 26.3 2.0 1.0 3.0 82.4 Example 2 26.0 2.0 1.0 3.0 80.3 Example 3 25.7 1.9 1.1 3.0 81.2 Example 4 25.8 1.9 1.2 3.1 82.1 Comparative Example 1 24.7 2.6 0.8 3.4 72.1 Comparative Example 2 25.1 2.2 0.9 3.1 71.2

[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 they were aligned at an angle of 90 degrees with respect to the circumferential middle 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 hardness of 40 or more and a shore A 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]

Tires were prepared in the same manner as in Example 5, except that the cord material for tire fabrication was a hybrid 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 hybrid dipped cord prepared 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 side fly-turn, and the carcass layer is installed so as to include one layer . The specifications of the cap ply 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]

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 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]

Tires were prepared in the same manner as in Example 5, except that the cord material for tire fabrication was a hybrid 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) 22.4 22.4 22.4 22.4 22.4 22.4 Modulus of elasticity
(g / d) 50 50 50 50 50 50 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 and 12 and Comparative Examples 3, 4, 5 and 6 was mounted on a 2000cc class passenger car, (DB), 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 the P-metric tire endurance test of FMVSS 109 at a temperature of 38 ° C (Celsius), 85, 90 and 100% of the rated tire load, at a running speed of 80 km / h And it was judged as OK (OK) when no traces such as bead separation, cord cutting, belt separation were found in any part such as tread, sidewall, carcass cord, inner liner and bead.

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 will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the appended claims. .

1: Pack 2: Nozzle
3 Cooling zone 4 outflow
5 emulsifying device
6, 7, 8, 9, 10 stretching roller
11 Final Opening Ceremony
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 (10)

In hybrid dipped cords for radial pneumatic tires,
A polyethylene terephthalate yarn and an aramid yarn are respectively laid one on top of one another and the raw cord made by joining them together is melted, the polyethylene terephthalate yarn is put in a state of 5 to 100 mm / m longer than the aramid yarn, The polyethylene terephthalate yarn is thermally shrunk during the heat treatment so that the length of the polyethylene terephthalate yarn and the length of the aramid yarn become the same when the dipped cord formed by heat treatment of the raw cord is melted,
Wherein the hybrid dipped cord has a strength of 25.5 kg or more and an intermediate elongation of 2.0% or less. The method according to claim 1,
Characterized in that the polyethylene terephthalate yarn is shrunk by controlling the tension during the heat treatment of the raw cord. The method according to claim 1,
Characterized in that the polyethylene terephthalate yarn is shrunk by temperature control during the heat treatment of the raw cord. The method according to claim 1,
When the raw cord is melted, the polyethylene terephthalate yarn is inserted into the aramid yarn by 7 to 50 mm / m longer than that of the aramid yarn, The method according to claim 1,
When the raw cord is melted, the polyethylene terephthalate yarn is inserted into the aramid yarn 10 to 30 mm / m longer than the aramid yarn. delete 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 ply as the belt reinforcing layer comprises the hybrid dipped cord according to any one of claims 1 to 5 and the cap ply 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,
Characterized in that the carcass layer comprises the hybrid dipped cord according to any one of claims 1 to 5 and the carcass layer 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 one polyethylene terephthalate yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM, respectively;
Folding the twisted yarn in two, and twisting the twisted yarn in a number of 200 to 500 TPM to produce a cord; And
And dipping the raw cord into an adhesive liquid and heat-treating the same, wherein a single polyethylene terephthalate yarn is inserted into the single yarn at a rate of 5 to 100 mm / m longer than the single aramid yarn, The polyethylene terephthalate yarn is thermally shrunk so that the length of the polyethylene terephthalate yarn becomes equal to the length of the aramid yarn,
Wherein the hybrid dipped cord has a strength of 25.5 kg or more and an intermediate elongation of 2.0% or less 10. The method of claim 9,
And the fineness of the polyethylene terephthalate yarn and the aramid yarn are respectively 500 to 3000 denier

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