KR101838492B1 - A High Tenacity Tire Cord using Nylon 6,6 or Nylon 6 and Aramid, and Radial Tires Produced by the Same - Google Patents

Abstract

The present invention relates to a high strength hybrid dipped cord using nylon 6.6 or nylon 6 yarn and an aramid yarn, and radial tires using the same. A method for producing the hybrid dipped cord according to the present invention comprises: a step of preparing one nylon 6.6 yarn or nylon 6 yarn and one aramid yarn; a step of adding one nylon 6.6 or nylon 6 yarn longer than the aramid yarn to produce twisted yarns of 200-500 TPM yarns each, thereby producing a lower yarn; a step of folding the twisted yarn in two to produce twisted yarns of 200-500 TPM to produce a raw cord; and a step of dipping the raw cord into adhesive liquid and performing heat treatment. During the heat treatment, the nylon 6.6 yarn or the nylon 6 yarn is heat-shrunk so that the length of the nylon 6.6 yarn or the nylon yarn 6 becomes equal to the length of the aramid yarn.

Description

TECHNICAL FIELD [0001] The present invention relates to a high tenacity tire cord using nylon 6.6 or nylon 6 yarn and an aramid yarn, and a radial pneumatic tire using the same, and more particularly, to a radial pneumatic tire using a high tenacity tire cord using Nylon 6,6 or Nylon 6 and Aramid,

The present invention relates to a high-strength tire cord using nylon 6,6 or nylon 6 and aramid yarns 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.

Polyethylene terephthalate is widely used as an air inlet radial tire, and more particularly, as a carcass ply material of air inlet radial tires having a flatness ratio of 0.65 to 0.82. In addition, a flat flat tire having a low flatness ratio, more specifically, a flatness ratio of less than 0.70 Rayon is used as a carcass ply reinforcement of high-speed air inlet radial tires.

In recent years, some of polyethylene naphthalate has been used for radial tires having a low flatness ratio at high speed. However, polyethylene naphthalate is superior to polyethylene terephthalate in terms of high temperature property and shape stability, but its price is high and its application is restricted. U.S. Patent No. 6,601,378 proposes a hybrid cord made by twisting a wound yarn of polyethylene terephthalate and polyethylene naphthalate, respectively. Polyethylene naphthalate fibers have a significantly higher modulus than polyethylene terephthalate fibers. Due to such differences in physical properties, when one of each of the wound yarns of polyethylene terephthalate and polyethylene naphthalate is twisted, it causes unevenness of tension in the raw cord. Due to such a problem, the strength utilization ratio at the time of twisting and dipping is rapidly deteriorated.

SUMMARY OF THE INVENTION The object of the present invention is to provide a nylon 6.6 or nylon 6 yarn and an aramid yarn with a suitable twist and a nylon 6.6 yarn or a nylon 6 yarn with a longer length than the aramid yarn, The present invention provides a high-strength hybrid dip cord for radial pneumatic tires having a length equal to the length of nylon 6.6 or nylon 6 and aramid yarns by thermally shrinking Si-nylon 6.6 or nylon 6 yarns, .

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 heat shrinking the nylon 6.6 or nylon 6 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 is characterized in that when one raw nylon 6.6 yarn, nylon yarn 6 yarn and one aramid yarn are respectively laid out and joined together, Or nylon 6 yarn is 5 to 100 mm / m longer than the aramid yarn, and when the dipped cord formed by heat treatment of the raw cord is melted, the nylon 6.6 yarn or the nylon yarn 6 and the aramid yarn are heat- Or a hybrid dipped cord obtained by heat shrinking nylon 6 yarns.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is characterized in that nylon 6.6 or nylon 6 yarn is shrunk by controlling the tension or 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 a hybrid dipped cord in which nylon 6.6 or nylon 6 yarn is inserted in a length of 7 to 50 mm / m longer than that of aramid yarn when the raw cord is finished.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is a hybrid dipped cord in which nylon 6.6 or nylon 6 yarn is inserted 10 to 30 mm / m longer than aramid yarn when the raw cord is finished.

According to another preferred embodiment of the present invention, the hybrid dipped cord of the present invention is characterized by having a strength of 40 kg or more and an intermediate elongation of 3.8% or less.

According to a preferred embodiment of the present invention, a method for producing a hybrid dipped cord of the present invention comprises the steps of: preparing one nylon 6.6 yarn or nylon 6 yarn and one aramid yarn; Adding one nylon 6.6 or nylon 6 yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM yarns, 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 dipping the raw cord into an adhesive liquid and heat-treating the single raw cord. In the step of preparing the bottom yarn, a single nylon 6.6 or nylon 6 yarn is inserted into the single aramid yarn by 5 to 100 mm / m And 6.6 yarns of nylon or 6 yarns of nylon 6 are thermally shrunk so as to be identical to aramid yarns 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 nylon 6.6 or nylon 6 yarn and aramid yarn is 500 to 3000 denier, respectively.

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 nylon 6.6 yarn or the nylon 6 yarn having high elongation equal to that of the aramid yarn having the high initial modulus to be equal in length after heat shrinkage so that the break point of the nylon 6.6 yarn or the nylon 6 yarn and the aramid yarn can be made equal , And the strength of the code can be improved.

According to the present invention, a hybrid dipped cord made of nylon 6.6 or nylon 6 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 reduce noise and steering stability And the like can be obtained satisfactorily.

Fig. 1 schematically shows a spinning and drawing process of nylon 6.6 yarn or nylon 6 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 nylon 6.6 yarn or the nylon 6 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, a method of manufacturing a nylon yarn used in the present invention will be described in detail with reference to the accompanying drawings.

The nylon used in the production of the hybrid tire cord of the present invention contains an amide group having strong polarity in the main chain and has a stereoregularity and symmetry and is crystalline. Generally, a polyamide refers to a generic term of a polymer linked by an amide bond (-CONH-), which can be obtained by condensation polymerization of a diamine and a dicarboxylic acid. Polyamides are characterized by amide bonds in the molecular structure, and their physical properties vary depending on the ratio of amide groups. For example, when the ratio of amide groups in the molecule is increased, specific gravity, melting point, absorbency, rigidity and the like are increased.

In addition, polyamide is a material used in a wide range of fields such as clothing, tire cord, carpet, rope, computer ribbon, parachute, plastic and adhesive due to its excellent resistance to corrosion, abrasion resistance, chemical resistance and insulation.

Generally, polyamides are classified into aromatic polyamides and aliphatic polyamides. Representative aliphatic polyamides include nylon. Nylon is originally a trademark of DuPont, Inc., but is now used as a generic name.

Nylon is a hygroscopic polymer and is sensitive to temperature. Representative nylons include nylon 6, nylon 66, and nylon 46.

First, nylon 6 is characterized by excellent heat resistance, moldability and chemical resistance, and is produced by ring-opening polymerization of ε-caprolactam in order to produce it. Nylon 6 means that caprolactam has 6 carbon atoms.

(Scheme 1) Nylon 6 polymerization of caprolactam

On the other hand, nylon 66 is generally similar in properties to nylon 6, but is superior in heat resistance to nylon 6 and superior in self-extinguishing and abrasion resistance. Nylon 66 is prepared by dehydration condensation polymerization of hexamethylenediamine and adipic acid.

(Scheme 2) Dehydration condensation of hexamethylenediamine with adipic acid Nylon 66 polymerization by polymerization

The polyhexamethylene adipamide polymer contains at least 85 mole percent hexamethylene adipamide repeat units, preferably only hexamethylene adipamide units.

Alternatively, optional polyamide homopolymers and copolymers may be used in place of polyhexamethylene adipamide. Such polyamides can be predominantly aliphatic. Poly (hexamethylene adipamide) (nylon 6.6); Poly (epsilon -caproamide) (nylon 6); And nylon 6.6 are most preferred, although widely used nylon polymers such as their copolymers can be used.

In order to improve the thermal stability during the production of the polyhexamethylene adipamide chip, the residual amount of the copper metal in the final polymer may be 20 to 50 ppm. If this amount is less than 20 ppm, the thermal stability is lowered during the spinning and pyrolysis occurs. If it exceeds 50 ppm, more than necessary copper metal acts as a foreign substance, which may be a problem in spinning. The polyhexamethylene adipamide chips prepared are made of fibers by the apparatus shown in Fig.

1, a polyhexamethylene adipamide chip is packaged through a pack 1 and a nozzle 2, preferably at a spinning temperature of 270 to 310 DEG C, preferably a radiation draft ratio of 20 to 200 The linear velocity on the roller / the linear velocity on the nozzle). This process is intended to prevent a decrease in the viscosity of the polymer due to thermal decomposition. If the spinning draft ratio is less than 20, the uniformity of the filament cross section may be deteriorated to deteriorate the drawability. If it exceeds 200, filament breakage may occur during spinning, thereby making it difficult to produce normal yarns.

The filtration residence time in the pack of chips in the melt spinning process should be adjusted to 3 to 30 seconds. If the filtration retention time in the pack is less than 3 seconds, the filtering effect of the foreign substance is insufficient, and if it exceeds 30 seconds, the excessive packing pressure may increase the pyrolysis. It is also preferred that the L / D (length / diameter) of the extruder screw in the melt spinning process is from 10 to 40. If the L / D of the screw is less than 10, uniform melting is difficult. If the screw has an L / D of more than 40, the molecular weight may be lowered due to excessive shear stress.

The produced melt discharge yarn 4 is quenched and solidified by passing through the cooling zone 3. The quenching and solidifying process is classified into an open quenching method, a circular closed quenching method and a radial outflow quenching method according to a method of blowing cooling air in the cooling zone 3, Of these methods, an open quenching method is preferred. Thereafter, the discharged yarn 4 which has passed through the cooling zone 3 and solidified is oiled to 0.5 to 1.0% by the emulsion applying device 5 and becomes unstretched.

The preferred spinning speed of the prepared non-drawn yarn is 200 to 1,000 m / min. The yarn passed through the first stretching roller 6 is stretched by a spin draw method while passing through a series of stretching rollers 7, 8, 9 and 10 so that the total yarn ratio is 4.0 times or more, preferably 4.5 to 6.5 To obtain the final drawn yarn 11.

It is advantageous that the value of the dry heat shrinkage (160 DEG C, 30 minutes) of the produced fiber is 3 to 6%. The low shrinkage ratio of such fibers can be obtained by stabilizing the crystal structure of the drawn yarn in the heat treatment step after the two-stage stretching process. The multi-stage drawing process in the fiber manufacturing process includes a primary drawing process which proceeds at a high drawing magnification at a low drawing temperature and a secondary drawing process which proceeds at a relatively low drawing magnification at a high temperature. In the primary drawing step, crystallization mainly proceeds by orientation. Crystallization by this orientation is a factor that determines the heat shrinkage of the cord. The preferred stretching temperature in the primary stretching step is 20 to 50 DEG C and the stretching ratio is 3.0 times or more. If an additional cooling device is not provided in the drawing roller in the process, it is difficult to control the drawing temperature to be less than 20 캜, which is economically disadvantageous. On the other hand, if the drawing temperature exceeds 50 캜, crystallization by heat may proceed. Further, if the draw ratio is less than 3.0 times, sufficient orientation crystallization hardly occurs.

Through the second elongation process, crystallization proceeds by heat at a high temperature. At these high temperatures, heat-induced crystals affect the heat shrinkage of the cord. In the secondary drawing step of the present invention, the drawing temperature is preferably 200 to 250 ° C and the drawing magnification is 2.0 times or less. When the drawing temperature is less than 200 ° C, sufficient crystallization does not proceed by heat. When the drawing temperature exceeds 250 ° C Causing damage to the product. Also, when the draw ratio exceeds 2.0 times, the elongation of the yarn decreases sharply. The relaxation temperature is adjusted to 200 to 250 ° C and the relaxation rate is adjusted to 3 to 7% in order to stabilize the crystal structure of the drawn yarn. The low shrinkage characteristics of such fibers can be prevented from rapidly shrinking in the treatment process for a tire cord, and thus they are represented by a high strength utilization ratio.

(2) a strength of 9.0 g / d or more; (3) an elongation of 10% or more; (4) a shrinkage of 10% or more; ) 500 to 3000 denier.

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 production of hybrid cords using nylon 6.6 or nylon 6 and aramid yarns manufactured. And a step of giving a cord to the cord as a pre-stage of dip code production (a twisting process).

The nylon 6.6 yarn or the nylon yarn 6 produced by the above method and the aramid yarn manufactured by the above method can be obtained by twisting one yarn of each wound yarn with a direct twisted yarn in which both the twisted yarns and the twin yarns are simultaneously wound, Raw code '. The raw cord is manufactured by applying a ply twist to a nylon 6.6 yarn for a tire cord or a nylon 6 yarn and an aramid yarn, and then applying a cable twist to the aramid yarn. In general, the same yarn is applied to the upper and lower yarns. An important twist yarn process in the present invention is to supply polyethylene terephthalate yarn longer than aramid yarn using the fact that nylon 6.6 yarn or nylon 6 yarn is thermally shrunk by heat treatment when the lower yarn for producing raw cord is applied.

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 soft 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 nylon 6.6 or nylon 6 yarn and aramid yarn used in 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 method for producing the hybrid dipped cord according to the present invention comprises the steps of: preparing one nylon 6.6 yarn or nylon 6 yarn and one aramid yarn; Adding one nylon 6.6 or nylon 6 yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM yarns, 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 dipping the raw cord into an adhesive liquid and heat-treating the single raw cord. In the step of preparing the bottom yarn, a single nylon 6.6 or nylon 6 yarn is inserted into the single aramid yarn by 5 to 100 mm / m , And heat-shrinking the nylon 6.6 yarn or the nylon 6 yarn so that the length of the nylon 6.6 yarn or the nylon 6 yarn becomes equal to the length of the aramid yarn.

The present invention relates to a process for producing a nylon 6.6 yarn, a nylon yarn 6.6 yarn, and a nylon yarn 6. In the step of kneading a single nylon 6.6 yarn or a nylon 6 yarn and a single aramid yarn, / m longer, and is characterized by controlling the tension or temperature so that the heat-shrinkable nylon 6.6 yarn or the nylon 6 yarn is thermally shrunk to the same length as the aramid yarn.

That is, nylon 6.6 yarn or nylon yarn 6 having high dry heat shrinkage ratio is heat-shrunk by 3 to 6% due to heat treatment, while aramid yarn having low dry heat shrinkage hardly undergoes heat shrinkage even after heat treatment so that the degree of heat shrinkage of nylon 6.6 yarn or nylon 6 yarn Considering the difference in length to which aramid is thermally shrinkable, when producing raw cord, nylon 6.6 yarn or nylon 6 yarn is inserted longer than aramid yarn to produce a raw cord, and when the raw cord is heat-treated, The nylon 6.6 yarn or the nylon 6 yarn and the aramid yarn can be made to have the same breaking timing by making the high elongation nylon 6.6 yarn or the nylon yarn 6 equal in length to the aramid yarn having the high modulus, so that the strength of the hybrid dipped cord and the initial modulus Is an excellent advantage.

If the nylon 6.6 or nylon 6 yarn is not added for a longer period of time in the step of preparing the lower yarn, the heat-shrinkable nylon 6.6 or nylon 6 yarn becomes shorter than the aramid yarn by heat shrinkage and the nylon 6.6 There is a problem that the strength of the cord is lowered because the nylon 6 is first subjected to the force.

Methods for heat shrinking nylon 6.6 or nylon 6 yarn include tension-controlled and temperature-controlled methods. 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. Depending on the heat treatment conditions, the degree of shrinkage of nylon 6.6 or nylon 6 may vary.

The degree to which nylon 6.6 or nylon 6 is added longer than 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 into the dip 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.

In particular, in the present invention, nylon 6.6 yarn or nylon 6 yarn is inserted longer than aramid yarn in the raw cord step, but in the heat treatment step, nylon 6.6 yarn or nylon 6 yarn is thermally shrunk It is characterized in that it is made equal to the length of the aramid yarn.

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 prepared according to the method described above is characterized by having a strength of 40 kg or more and an intermediate elongation of 3.8% or less. When the strength is less than 40 kg, the stability of handling is reduced when the tire is manufactured, and when the intermediate elongation is more than 3.8%, 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 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]

Nylon 6.6 and aramid fibers were obtained in the same manner as described above to produce tire reinforcing fibers. One knot of nylon 6.6 yarn (1260D) and one yarn of aramid yarn (1500D) were each twisted at 400 TPM, and the yarn was folded to give a twist of 400 TPM. The nylon 6.6 yarn was inserted 10 mm / m longer. 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 laminate was heat treated at 240 ° C for 60 seconds to shrink the nylon 6.6 yarn so that the shrinked length was the same as 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]

A hybrid dipped cord was prepared in the same manner as in Example 1 except that the fineness of the aramid yarn was 1000 denier and the fineness of the nylon 6.6 yarn was 840 denier. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Example 3]

Nylon 6.6, and 20 mm / m longer, and heat-treated for 70 seconds, thereby producing a raw cord and a dipped cord. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Example 4]

Nylon 6.6, yarn 30 mm / m longer, and heat-treated for 80 seconds to prepare a raw cord and a dipped cord. The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Example 5]

Nylon 6.6, yarn 40 mm / m longer, and heat-treated for 90 seconds to prepare a raw cord and a dipped 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 (1500D) was subjected to a lead of 40 TPM, followed by one aramid yarn (1500D) and one nylon yarn 6 and 6 yarns (1260D) were each twisted at 400 TPM to produce a hybrid dipped cord in the same manner as in Example 1, except that the nylon 6.6 yarn and the aramid yarn were fed in the same length while the lower yarn was manufactured and joined . The properties of the thus-prepared dip cords were evaluated and are shown in Table 1.

[Comparative Example 2]

During the twisting process for the production of raw cord, a nylon 6.6 yarn (1260D) and an aramid yarn (1500D) were each twisted with a twist of 400 TPM to produce a twist yarn, while the nylon 6.6 yarn and the aramid yarn were fed in the same length , A hybrid dipped cord was prepared in the same manner as in Example 1. The results are shown in Table 1. < tb > < TABLE > 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
6.8kg (%) Shrinkage (%) ES value (%) My fatigue (%) Example 1 40.5 3.8 1.1 4.9 70.8 Example 2 26.8 3.6 1.1 4.7 71.2 Example 3 41.1 3.5 1.3 4.8 68.8 Example 4 40.7 3.2 1.5 4.7 67.2 Example 5 41.3 3.0 1.6 4.6 65.0 Comparative Example 1 35.4 5.0 1.7 6.7 72.1 Comparative Example 2 36.3 4.6 1.8 6.4 71.2 My fatigue is low

In the case of the hybrid dipped cord according to the present invention (Examples 1, 2, 3, 4 and 5), the strength of the hybrid dipped cord according to the present invention is improved compared with the hybrid dipped cord prepared according to the comparative example Able to know.

[Example 6]

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 7]

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 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 3.

[Example 9]

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.

[Example 10]

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 5.

[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 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 3 Comparative Example 4 Kakas Material Polyethylene
Terephthalate 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 1500d / 2 Strong (Kg) 24 24 24 24 24 24 24 Modulus of elasticity (g / d) 60 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 Example 5 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 0.60 Number of carcass layers One One One One One One One Cap fly layer number One One One One One One One

[Example 11]

A radial tire produced by using the hybrid dipped cord prepared in 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 . At this time, 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 6.

[Example 12]

Tires were produced in the same manner as in Example 6, except that the hybrid dipped cord prepared in Example 2 was used as the cord material for tire production.

[Example 13]

A tire was produced in the same manner as in Example 6, except that the hybrid dipped cord prepared in Example 3 was used as a cord material for tire production.

[Example 14]

A tire was prepared in the same manner as in Example 6, except that the hybrid dipped cord prepared in Example 4 was used as a cord material for tire production.

[Example 15]

A tire was produced in the same manner as in Example 6, except that the hybrid dipped cord prepared in Example 5 was used as the cord material for tire production.

[Comparative Example 5]

A tire was produced in the same manner as in Example 6, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Comparative Example 1. [

[Comparative Example 5]

A tire was produced in the same manner as in Example 6, except that the cord material for tire fabrication was the hybrid dipped cord prepared in Comparative Example 1. [

Example 11 Example 12 Example 13 Example 14 Example 15 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 Example 5 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 Nylon 6, 6 Specification (d / summing speaker) 1260d / 2 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 22.4 Modulus of elasticity
(g / d) 50 50 50 50 50 50 50 tire Flat rate 0.60 0.60 0.60 0.60 0.60 0.60 0.60 Number of carcass layers One One One One One One One Cap fly layer number One One One One One One One

The 205/65 R15 V tire manufactured according to Examples 6 to 15 and Comparative Examples 3 to 6 was mounted on a 2000cc class passenger car and traveling at a speed of 60 km / h to measure the noise generated in the vehicle, (DB). Steering stability and riding comfort were evaluated by a skilled driver on a test course in five 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 6 9.98 100 100 OK 100 60.4 Example 7 9.98 100 100 OK 100 60.4 Example 8 9.99 100 100 OK 100 60.5 Example 9 10.02 100 100 OK 100 61.2 Example 10 10.1 100 100 OK 100 61 Comparative Example 3 10.01 97 96 OK 92 62 Comparative Example 4 10.08 94 95 OK 93 62.1 Example 11 10.2 100 100 OK 100 60.4 Example 12 10.2 100 100 OK 100 60.3 Example 13 10.12 100 100 OK 100 60.4 Example 14 10.0 100 100 OK 100 60.6 Example 15 10.21 100 100 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

As a result of the tests of Table 4, the tires (Examples 6 to 15) using the hybrid cord according to the present invention were more effective in noise reduction and steering stability than 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,
When one raw nylon 6,6 yarn or nylon 6 yarn and one aramid yarn were respectively laid and knitted together, the nylon 6.6 yarn or the nylon 6 yarn was used as the aramid yarn When the dipped cord formed by heat treatment of the raw cord is melted, nylon 6.6 yarn or nylon 6 yarn is used for the heat treatment so that the length of the aramid yarn becomes equal to that of the nylon 6.6 yarn or the nylon yarn 6. [ As heat-shrinkable,
Wherein the hybrid dipped cord has a strength of 40 kg or more and an intermediate elongation of 3.8% or less. The method according to claim 1,
Characterized in that the nylon 6.6 or nylon 6 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 nylon 6.6 or nylon 6 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 nylon 6.6 or nylon 6 yarn is inserted into the aramid yarn by 7 to 50 mm / m longer than the aramid yarn. The method according to claim 1,
When the raw cord is melted, the nylon 6.6 or nylon 6 yarn is inserted 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 nylon 6.6 yarn or nylon 6 yarn and one aramid yarn;
Adding one nylon 6.6 or nylon 6 yarn to the aramid yarn longer than the aramid yarn to produce a twisted yarn of 200 to 500 TPM yarns, 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 single raw cord. In the step of preparing the bottom yarn, one nylon 6.6 or nylon 6 yarn is inserted into the single aramid yarn by 5 to 100 mm / During the heat treatment, nylon 6.6 yarn or nylon 6 yarn is thermally shrunk so that the length of the nylon 6.6 yarn or the nylon 6 yarn becomes equal to the length of the aramid yarn,
Wherein the hybrid dipped cord has a strength of not less than 40 kg and an intermediate elongation of not more than 3.8% 10. The method of claim 9,
Wherein the fineness of the nylon 6.6 or nylon 6 yarn and the aramid yarn are respectively 500 to 3000 denier

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