KR20080061702A - High performance radial tire with polyethylenenaphthalate cord for cap ply - Google Patents

Abstract

A high performance radial tire with a cap ply layer of a polyethylene naphthalate deep cord is provided to improve the adhesion force to rubber and the anti-fatigue property. A bead area(35) of a tire(31) is an annular bead core(36) with the non-extension type. The bead core is made of mono filament steel line wound continually, preferably. The bead area has a bead pillar(37) with hardness of above constant level such as shore A hardness of above 40. A crown portion of the tire is reinforced by a belt structure(38) and a cap ply(39). The belt structure includes a cutting belt ply(40) made of two belt cords(41,42). The belt cord of the belt ply is aligned with about 20 degrees about the center surface of the circumferential direction of the tire. A belt cord of the belt ply is arranged toward the contrary direction to the belt cord of another belt ply. The belt structure includes any number of plies arranged at the range of 16 to 24 degrees.

Description

High performance radial tire with Polyethylenenaphthalate cord for cap ply}

Figure 1 schematically illustrates a polyethylene naphthalate spinning process according to the present invention.

Figure 2 schematically shows the structure of a tire for a passenger car manufactured using the polyethylene naphthalate dip cord according to the present invention in a cap fly cord.

※ Brief description of the main symbols in the drawing

31: tire 32: carcass layer

33: code for reinforcing the carcass layer 34: fly turn-up

35: bead area 36: bead core

37: Bead Filler 38: Belt Structure

39: cap fly 40: belt fly

41, 42: belt code 43: tread

44: edge fly 45: cap fly code

The present invention relates to a radial tire with a cap ply made of polyethylene naphthalate dip cord.

In recent years, tire performance has been continuously improved as road environments and vehicle performances improve. In particular, as the weight of the vehicle increases and the limit speed increases, safety is recognized as an important tire quality factor. In accordance with the demand for increased tire safety, tire safety standards are also changing, and the tire industry is actively researching methods for providing tire safety.

The installation of a cap ply on a tire for a passenger car is for the safety of the tire. Recently, a tire having such a cap ply has become common. The cap ply refers to a part that is continuously wound between the tire tread portion and the belt reinforcing steel cord layer without breaking in the circumferential direction of the tire to maintain the shape stability of the tire. Such cap plies are typically reinforced with materials that have heat shrinkage at high temperatures. When the vehicle runs, a load is applied in the axial direction of the tire cord, and the tire cord is deformed and recovered in the axial direction by this load. In this strain-recovery, the tension-load curves during deformation and recovery occur along the curves, and the work loss of the tire cord itself occurs due to the difference in recovery curves that appear as the deformation and loads are removed by the tensile load. Done. This work loss contributes to the temperature rise of the tire and the tire cord, and the work loss causes energy loss while the tire rotates, resulting in energy loss while driving. This energy loss leads to the rolling resistance of the vehicle, and in general, when using a material having high energy loss characteristics, the fuel efficiency of the vehicle is increased due to the increase in the rolling resistance of the tire and the temperature of the tire is increased due to driving. . The role of the cap ply material is to prevent the size of the tire from growing by driving the cap ply when the temperature of the tire increases due to the driving of the vehicle. In this case, since the tire does not increase in size, an increase in tire rotational inertia is prevented, resulting in a reduction in energy consumption and suppression of heat generation of the tire, thereby leading to an increase in fatigue life and an increase in durability.

In general, the most widely used material for cap ply material is nylon 66 due to the high shrinkage of nylon 66. The part where the cab ply is reinforced is known to be the hottest part of the tire. Therefore, besides the heat shrinkage force, a material having heat resistance should be used, and a material having a low deterioration in adhesion force by heat should be used. Nylon 66 is the material used for tire cords with these properties. The research for applying to the cap ply using other materials, such as PET, is also in progress, but these materials are weak to heat, and in particular, it is difficult to be applied to the cap ply due to the large decrease in adhesive strength due to heat.

Another material that can be used for the cap ply is aramid. Aramid has different characteristics from nylon 66. Aramid fibers are aromatic polyamide fibers which are polyamide fibers having a benzene ring in a repeating unit. When applied to a tire cap ply as a material that shows stable physical properties even at high temperatures, it is difficult to expect the development of shrinkage at high temperatures, but the deformation is suppressed because the property deterioration is very small even at high temperatures, which is similar to the result of applying the nylon cap ply. Therefore, the use of such aramid fibers is increasing, but aramid fibers have a problem of low fatigue resistance and at the same time the price is very expensive, the cost problem occurs.

In order to solve the problems with the material of the cap ply of the conventional radial tire of the present invention has the following object.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to provide a radial pneumatic tire having a capfly layer to which a deep cord is made of polyethylene naphthalate multifilament.

The radial pneumatic tire according to the present invention has excellent physical properties with improved adhesion and fatigue resistance to rubber, which is a disadvantage of polyethylene naphthalate fiber, and exhibits improved strength and high temperature properties.

According to a suitable embodiment of the invention, a pair of parallel bead cores; At least one radial carcass fly wound around the bead core; A belt layer laminated on a carcass ply outer circumference; And a radial pneumatic tire including a circumferential belt reinforcement layer formed on an outer circumference of the belt layer, wherein the cap ply includes a dip cord made of polyethylene naphthalate high strength yarn and polyethylene naphthalate high elongation yarn, and the dip cord is (1) 15 To 23 kg strength; (2) a median elongation of 2.2 to 2.4%; (3) at least 12 kg of adhesion to rubber; (4) at least 85% fatigue resistance; And (5) shrinkage ratios of 0.8 to 1.4%.

According to another suitable embodiment of the present invention, the polyethylene naphthalate high strength yarns have a strength of 9.2 to 9.7 g / d; Median elongation 2.4-3.0%; And elongation 8 to 10%.

According to another suitable embodiment of the present invention, the polyethylene naphthalate high elongation yarn has a strength of 8.8 to 9.2 g / d; Median elongation 3.0-3.5%; And elongation 10 to 15%.

According to another suitable embodiment of the present invention, the fineness of the polyethylene naphthalate high strength yarn and the polyethylene naphthalate high elongation yarn is 500 to 2000, respectively.

According to another suitable embodiment of the present invention, the deep cord fineness is 1000 to 6000 denier.

According to another suitable embodiment of the present invention, the cap ply is two layers.

Capfly cord for a radial pneumatic tire according to the present invention is manufactured through the following process.

Polyethylenenaphthalate multifilament is produced as a preliminary step for producing the cord for the capply layer.

Polyethylene naphthalate fibers, in particular polyethylene-2,6-naphthalate fibers, are produced through the following process.

Polyethylene-2,6-naphthalate polymers for the production of fibers contain at least 85 mole% of ethylene-2,6-naphthalate units and preferably comprise only ethylene-2,6-naphthalate units.

Optionally, the polyethylene-2,6-naphthalate comprises a small amount of units derived from one or more ester-forming compounds other than ethylene glycol and 2,6-naphthalene dicarboxylic acid or derivatives thereof as copolymer units. It may include. Polyethylene naphthalate units and other copolymerizable ester forming compounds include glycols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, terephthalic acid, isophthalic acid, hexahydroterephthalic acid, stilbenica Dicarboxylic acids such as carboxylic acid, bibenzoic acid, adipic acid, sebacic acid, and azelaic acid.

Polyethylene naphthalate chip is melt-mixed naphthalene-2,6-dimethylcarboxylate (NDC) and ethylene glycol raw material at 190 ℃ in the ratio of 2.0 to 2.3, and the melt mixture is transesterified (220 to 230 ℃ about 2 to 3 hours) and condensation polymerization (about 2 to 3 hours at 280 to 290 ° C.) to produce raw chips with an intrinsic viscosity of at least 0.42, followed by 0.80 at a temperature of 240 to 260 ° C. and vacuum. It can be prepared by the method of solid-phase polymerization to have an intrinsic viscosity of 1 to 1.20 and a moisture content of 30 ppm or less.

Optionally, an amount of manganese compound, preferably manganese acetate, may be added to the manganese metal in the final polymer so as to have a residual amount of 30 to 70 ppm as a transesterification catalyst in the transesterification process. If the amount is less than 30 ppm, the transesterification reaction is too slow. If the amount is more than 70 ppm, more than necessary manganese metal acts as a foreign matter, which may cause problems during solid state polymerization and spinning.

Optionally, in the polycondensation reaction, as the polymerization catalyst, a certain amount of the antimony compound, preferably an amount such that the amount of antimony trioxide remaining as antimony metal in the final polymer is 180 to 300 ppm can be added. If the amount is less than 180 ppm, the polymerization reaction rate is lowered, and the polymerization efficiency is lowered. If the amount is more than 300 ppm, more than required antimony metal acts as a foreign material, which may lower the radio-stretching workability. In addition, a certain amount of the phosphorus heat resistant stabilizer, preferably an amount such that the amount of trimethyl phosphate remaining as a phosphorus element in the final polymer as 35 to 45 ppm can be added, and the manganese / phosphorus content ratio is 2.0 or less. do. If the manganese / phosphorus content ratio is higher than 2.0, the oxidation is promoted during the solid phase polymerization, so that normal physical properties cannot be obtained during spinning.

The polyethylene naphthalate chip thus produced is made of fibers and FIG. 1 schematically shows the process of making the fibers.

Referring to FIG. 1, the polyethylene naphthalate chip is produced through a pack 1 and a nozzle 2 at a spinning temperature of preferably 290 to 328 ° C., preferably of a spinning draft ratio of 20 to 200 (on the first winding roller). Low-temperature melt spinning at a linear velocity / linear velocity at the nozzle). This process is intended to prevent the lowering of the viscosity of the polymer by pyrolysis and hydrolysis. In this process, if the spinning draft ratio is less than 20, the uniformity of the filament cross-section is worsened, the drawing workability is significantly reduced, and if it exceeds 200, filament breakage occurs during spinning, making it difficult to produce a normal yarn.

The produced melt-discharge yarn 4 passes through the cooling zone 3 to rapidly cool. In addition, if necessary, a short heating device may be installed at a distance from the nozzle 2 directly to the start point of the cooling zone 3, that is, the length L of the hood.

The zone in which the heating device is installed is a delayed cooling zone or heating zone and maintains a length of 50 to 250 mm and a temperature of 250 to 400 ° C. (air contact surface temperature).

In the cooling zone (3), open quenching, circular closed quenching, and radial outflow quenching may be applied depending on the method of blowing cooling air. The invention is not limited by this method. Then, the discharged yarns 4 solidified through the cooling zone 3 are oiled at 0.5 to 1.0% by the oil agent imparting device 5 to be manufactured as unburned yarns.

The produced non-drawn yarn passes through a series of drawing rollers 6, 7, 8, 9 and 10 by spin draw method, and has a total draw ratio of at least 4.0 times, preferably within 4.5 To 6.5 to obtain a final drawn yarn (11).

As close as possible to the distance between the nozzle and the top of the cooling section during spinning, it is advantageous to have a high strength in the final stretched yarn. If the distance from the bottom of the heater to the bottom of the heater is 50 mm or less during the spinning (in fact, there is a spinning block about 50 mm in length directly under the nozzle, so if you use a 50 mm length heater, the distance from the bottom of the heater to the bottom of the heater 100mm) or when the distance between the bottom of the heating device and the top of the cooling device is out of 50 to 150mm, non-uniformity of undrawn yarn is generated to a large extent, and drawing of normal physical properties becomes impossible.

Stretched polyethylene naphthalate fibers produced according to the process of the invention have a fineness of 500 to 2000 denier, and (1) intrinsic viscosity of 0.60 to 0.90; (2) a strength of at least 8.5 g / d; (3) elongation at least 6.0%; (4) birefringence of 0.35 or greater; (5) a density of 1.355 to 1.375; (6) melting point of # 270 to 285 ° C; And (7) a shrinkage of 1 to 4%.

In addition, according to the present invention, the high-strength yarn and the high-strength yarn are used for spinning. High strength yarns of strength from 9.2 to 9.7 g / d; Median elongation 2.4-3.0%; And elongation 8-10%, high elongation yarn strength 8.8-9.2 g / d; Median elongation 3.0-3.5%; And elongation 10 to 15%.

In order to manufacture a radial pneumatic tire according to the present invention, a deep cord must be manufactured using the polyethylene naphthalate high strength yarn and the polyethylene naphthalate high elongation yarn multifilament yarn. In addition, as a preliminary step of the deep cord manufacturing, a step of giving a cord to the cord (a twisting process) is required.

In the present invention, in manufacturing a deep cord using the polyethylene naphthalate high-strength yarn and polyethylene naphthalate high elongated yarn, as a pre-step of the deep cord manufacturing, the raw cord is subjected to a twist (manufacturing process) by applying a twist to the cord. .

The method for producing a raw cord according to the present invention comprises the steps of producing a twisted yarn by giving S-direction twist of 30 to 90 TPM soft water to one polyethylene naphthalate high elongated yarn, the first polyethylene naphthalate high elongated yarn and Giving twist in the Z direction of 300 to 500 TPM soft water to one polyethylene naphthalate high-strength yarn which is not twisted, respectively, to prepare a lower twisted yarn; It is prepared by the method comprising the step of adding the aromatic phase lead to the raw cord, the method comprising the step of immersing the raw cord in a dipping solution, or, one polyethylene naphthalate high elongated yarn and one polyethylene naphthalate high strength Twist the number of softeners of polyethylenenaphthalate high elongated yarn in the Z direction to 30 to 90 TPM lower than that of high strength polyethylenenaphthalate yarn Preparing a CS and to give, to braided and the CS and in the second stage was added to S direction of 300 to 500 TPM training comprises the steps of preparing a raw cord. The raw cord manufactured according to the manufacturing method of the present invention becomes a dip cord through a step of dipping in a dipping liquid.

According to the present invention, the raw cord is produced by twisting the S-direction of 30 to 90 TPM soft water to one polyethylene naphthalate high elongated yarn to produce linear twisted yarn, or one polyethylene naphthalate high elongated yarn and one used in the lower rolling process. Polyethylene naphthalate high-strength yarn in polyethylene naphthalate high elongated yarn is adjusted to 30 to 90 TPM lower than polyethylene naphthalate high-strength yarn is produced through the twisting method of producing a low-twist yarn after the upper twist process. This process is designed so that the tensile stress acts preferentially on the polyethylene naphthalate high elongated yarn during the initial extension of the raw material by adjusting the final twist number (the number of twists applied after the lower lead to the upper edge) to the high elongated polyethylene naphthalate high elongated yarn. By doing so, the break point of the polyethylene naphthalate high strength yarn and the polyethylene naphthalate high elongation yarn can be made the same, and therefore, the strength of the raw cord can be improved. At this time, giving less than 30 TPM edge to the polyethylene naphthalate high-strength yarn may have a negligible effect on the edge, so that the tensile stress may act on the polyethylene naphthalate high-strength yarn when the raw cord is stretched. Giving edges may cause problems that the tensile stress is excessively concentrated in the polyethylene naphthalate high elongation yarn during the extension of the raw cord.

Further, in the present invention, physical properties such as the elongation, the core and fatigue resistance of the cord change depending on the level of twisting (the number of years) applied to the polyethylene naphthalate high elongation yarn and the polyethylene naphthalate high strength yarn at the time of lower or upper edge. In general, when the twist is high, the strength decreases, and the trunk and the body tend to increase. In addition, fatigue fatigue tends to improve with increasing twist. The number of years of hybrid tire cords produced in the present invention was produced at 300/300 TPM to 500/500 TPM at the same time as the upper and lower edges, and the upper and lower edges were given the same value, and the produced tire cords did not show rotation or twist. It is to maximize physical expression by making it easy to maintain a straight line without. At this time, if less than 300/300 TPM, the extension of the raw cord is reduced and fatigue fatigue is easy to fall, and if it exceeds 500/500 TPM, the strong degradation is large and is not suitable for the tire cord.

The produced 'Raw Cord' is woven into a fabric using a weaving machine and the obtained fabric is immersed in a dipping liquid. Then, the fabric is cured to produce a 'Dip Cord' for a tire cord having a resin layer attached to the raw cord surface.

In the above process, dipping refers to impregnating a surface of a fiber with a resin layer called Resorcinol Formaline Latex (RFL). This is done to ameliorate the disadvantages of the fibers for tire cords which are inherently poor in adhesion with rubber.

In the present invention, the adhesive solution for the adhesion of the cord and rubber can be prepared using the following method.

Manufacturing method of adhesive liquid

45.6 parts by weight of 29.4 wt% resorcinol;

255.5 parts by weight of distilled water;

20 parts by weight of 37% formalin; And

10 wt% sodium hydroxide 3.8 parts by weight

Prepare a solution containing the reaction after stirring for 5 hours at 25 ℃ add the following components.

40wt% VP-latex 300 parts by weight

129 parts by weight of distilled water

23.8 parts by weight of 28% aqueous ammonia.

After the addition of the ingredients it is aged for 20 hours at 25 ℃ to maintain a solid concentration of 19.05%.

The adhesive is applied after the dip cord is dried. In order to control the adhesion amount of the adhesive liquid, a stretch of 0 to 3% is required, and preferably 1 to 2% of stretching can be made. If the elongation ratio is too high, the adhesion amount of the adhesive liquid can be controlled but the elongation is reduced and consequently the fatigue resistance is reduced. On the other hand, if the elongation rate is too low, for example, when the elongation rate is lowered to less than 0%, a problem arises in that the dipping liquid penetrates into the polyethylene naphthalate high-conductor cord, making it impossible to control the DPU.

The adhesive amount is preferably 4 to 6% by weight of the fiber based on the solid content. After passing through the adhesive liquid, the dip cord is dried at 120 to 150 ℃. The drying time may be 180 seconds to 220 seconds, and in the drying process, the deep cord may be stretched by 1 to 2%. When the elongation ratio is low, the core and the elongation of the cord may increase, indicating physical properties that are difficult to apply to the tire cord. On the other hand, if the elongation rate is over 3%, the neutrophil level is appropriate but the body length is too small, which may reduce fatigue resistance.

After drying, heat treatment is carried out in a temperature range of 130 to 240 ℃. Elongation ratio during the heat treatment is maintained between -2 to 0%, heat treatment time is appropriate 50 seconds to 90 seconds. When the heat treatment is performed for less than 50 seconds, the reaction time of the adhesive liquid is insufficient, resulting in low adhesive strength. When heat treatment is performed for 90 seconds or more, the hardness of the adhesive liquid may be increased, thereby reducing the fatigue resistance of the cord. .

Dipping may be performed using a two bath dipping machine but heat treatment may be performed under the same conditions using a one bath dipping machine.

Polyethylene naphthalate deep cord prepared according to the above-described method has a fineness of 1000 to 6000, and the adhesive force of at least 6 kg, preferably 10 to 30 kg; And the cutting load can be advantageously used as a tire cord for passenger cars in the range of 10.0 to 35.0 kg.

Polyethylenenaphthalate deep cords prepared according to the methods described above can be used for the preparation of the capply layer. And the high performance radial pneumatic tire made in accordance with the present invention comprises such a capply layer.

Figure 2 shows a partial cross-sectional view of the structure of a tire for a passenger car manufactured using a polyethylene naphthalate deep cord according to the present invention as a cap ply.

Referring to FIG. 2, the bead regions 35 of the tire 31 become annular bead cores 36 that are each non-extensible. The bead core 36 is preferably made from a single filament steel wire wound continuously. In a preferred embodiment, the high strength steel wire of 0.95 mm to 1.00 mm diameter becomes a 4x4 structure or a 4x5 structure. In the embodiment of the tire cord according to the present invention, the bead region 35 may have a bead filler 37, the bead filler 37 should have a hardness of a predetermined level or more, preferably Shore A hardness ( Shore A hardness) It may have a hardness of 40 or more.

According to the present invention, the tire 31 may be reinforced with the crown portion by the belt structure 38 and the cap fly 39. The belt structure 38 comprises a cutting belt ply 40 consisting of two belt cords 41 and 42 and the belt cord 41 of the belt ply 40 is about 20 with respect to the circumferential center surface of the tire. Can be oriented at an angle of k. One belt cord 41 of the belt ply 40 may be arranged in a direction opposite to the circumferential center surface, opposite to the direction of the belt cord 42 of the other belt ply 40. However, the belt structure 38 may comprise any number of plies, and may preferably be arranged in the range of 16 to 24 degrees. The belt structure 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 belt cords 41 and 42 of the belt structure 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 structure 38. The cap ply cord 45 of the cap ply 39 is reinforced in parallel with the circumferential direction of the tire to prevent high speed rotation of the tire. The cap fly cord 45 of the cap ply 39 which acts to suppress the size change in the circumferential direction and has a large heat shrinkage stress at high temperature is used. The capply cord 45 of the capply 39 may be manufactured using a deep cord made of a high strength yarn and a high elongated yarn manufactured according to the method of the present invention. One layer of cap ply 39 and one layer of edge ply 44 may be used, preferably one or two layers of cap ply and one or two layers of edge plies.

Reference numerals 32 and 34, which are not described in FIG. 2, represent the carcass layer 32 and the fly turn up 34. Reference numeral 33 denotes a carcass layer reinforcing cord 33.

Examples and comparative examples which do not limit the scope of the invention are described below. In the following Examples and Comparative Examples, the properties of the deep code were evaluated in the following manner.

Property measurement method

(a) Polyethylenenaphthalate tire cord strength (kgf) and medium elongation (%)

After drying at 107 ° C. for 2 hours, an Instron low speed tensile tester was used. After twisting 80 TPM (80 twist / m), the sample length was measured at 250 mm and a tensile speed of 300 m / min. At this time, the elongation at specific load is measured by applying different loads according to the fineness of the deep cord as follows.

end. 1000 (PEN) denier high strength yarn and high tensile yarn / 2ply hybrid deep cord, load 4.5kg

I. 1500 (PEN) Denier High Strength Yarn and High Tensile Yarn / 2ply Hybrid Deep Cord, Load 6.8kg

All. 1000 (PEN) denier / 2 go deep cord, load 4.5kg

la. 1500 (PEN) Denier / 2 go deep cord, load 6.8kg

hemp. 1500 (polyethylene terephthalate) denier / 2 go deep cord, load 6.8 kg

(b) Dry heat shrinkage (%, Shrinkage)

After leaving at 25 ° C and 65% RH for 24 hours, using the ratio of the length (L ₀ ) measured in 20g stop and the length (L ₁ ) after treatment at 20g static load for 30 minutes at 150 ° C The dry heat shrinkage is indicated by.

S (%) = [(L ₀ -L ₁ ) / L ₀ ] × 100

(c) Polyethylenetaphthalate deep cord ES

Elongation under a constant load is referred to as the median elongation (E) in the present invention, 'S' means the dry heat shrinkage of the above (b), the sum of the intermediate elongation (E) and dry heat shrinkage (S) is called 'ES' And the following formula.

ES = median elongation (%) + dry heat shrinkage (%)

(d) even with fatigue

The fatigue strength of the tire cord was measured by using a belt fatigue tester (Belt Fatigue Tester) that is commonly used for fatigue testing of tire cords. Fatigue test conditions were 40 ℃, load 70 kg, compression 34.58% conditions, and after the fatigue test was swelled in a tetrachloroethylene solution for 24 hours to swell the rubber, and the rubber and the cord was separated to measure the remaining strength. The residual strength was measured after drying at 107 ° C. for 2 hours using a conventional tensile strength tester according to the method (a) above.

(f) adhesion

H-test was performed to measure the initial adhesion of the polyethylenetaphthalate dip cord to the rubber. H-test measures the maximum load that the rubber-cord separation occurs by pulling both rubbers while keeping both ends of the deep cord embedded in 9.5mm rubber lumps and keeping the distance between the rubber lumps at both ends 9mm. It is a method of evaluating adhesive force. In addition, sufficient strength is given to a rubber | gum by measuring at 20 degreeC and the pressure of 25 kg / cm <^2> for 20 minutes, before adhesive force evaluation. The rubber composition used in the test was 100 parts of natural rubber, 3 parts of zinc oxide, 28.9 parts of carbon black, 2 parts of stearic acid, 7.0 parts of pintar, 1.25 parts of MBTS, 3 parts of sulfur, 0.15 parts of diphenyl guanidine and phenylbeta naphthylamine 1.0 part is mix | blended.

Example

Example 1

In order to manufacture the fiber for tire reinforcement, polyethylene naphthalate high strength yarn and polyethylene naphthalate high elongation yarn filament fiber were obtained as described above. In twisting the obtained polyethylene naphthalate high strength and polyethylene naphthalate high elongation fibers at 1000 denier / 2ply, respectively, the yarn tension was maintained at a level of 200 g per head, and twisted in the S direction of 90 TPM soft water to one polyethylene naphthalate high elongation yarn. The step of preparing the twisted yarn to give, the twisted yarn in the Z direction of 390 TPM soft water to give one polyethylene naphthalate high-strength yarn twisted yarn and one polyethylene naphthalate high-strength yarn is not twisted, respectively In the manufacturing step, the lower twisted yarn was spliced into two and added to the S-direction upper edge of 390 TPM soft water.

The obtained record was dried at 100 ° C. for 130 seconds, and then passed through an adhesive prepared in the following manner to give an adhesive. 2% stretch was applied during drying to prevent non-uniformity of the record due to heat shrinkage.

45.6 parts by weight of 29.4 wt% resorcinol;

255.5 parts by weight of distilled water;

20 parts by weight of 37% formalin; And

10 wt% sodium hydroxide containing 3.8 parts by weight

After the solution was prepared, it was reacted with stirring at 25 ° C. for 5 hours and the following components were added:

40wt% VP-latex 300 parts by weight

129 parts by weight of distilled water

23.8 parts by weight of 28% aqueous ammonia

After the ingredient was added, it was aged at 25 ° C. for 20 hours to maintain a solid concentration of 19.05%.

After giving an adhesive liquid and drying at 150 degreeC for 2 minutes, it heat-processed at 170 degreeC for 1 minute, and the adhesive process was complete | finished. The physical properties of the hybrid dip cord thus prepared are shown in Table 1 below.

Example 2

Except that the polyethylene naphthalate high-strength yarn and polyethylene naphthalate high-strength fibers were twisted in 1500 denier / 2 polyps, the experiment was carried out in the same manner as in Example 1 to prepare a raw cord and a dip cord.

Comparative example

Comparative Example 1

Except that the polyethylene naphthalate multi-filament was twisted to 1000 denier / double sum, the experiment was carried out in the same manner as in Example 1 to prepare a raw cord and a deep cord. Table 1 shows the physical properties of the dip cord thus prepared.

Comparative Example 2

Except that the polyethylene naphthalate multi-filament was twisted to 1500 denier / double sum, the experiment was carried out in the same manner as in Example 1 to prepare a raw cord and a deep cord. Table 1 shows the physical properties of the dip cord thus prepared.

Table 1

As a result of the test of Table 1, in the case of the deep cord according to the present invention (Example 1-2), a deep cord using only polyethylene naphthalate of the same physical property (Comparative Example 1) or a general polyethylene terephthalate deep cord It can be seen that the adhesion is slightly improved compared with the fatigue resistance significantly improved.

Example

Example 3

The radial tire manufactured by using the hybrid deep cord manufactured according to Example 1 of the present invention as a cap ply has a carcass layer having a radially outer ply turnup, and the carcass layer is formed to be one layer. At this time, the specifications of the carcass cord were as shown in Table 3 below, and were oriented at a 90 degree angle with respect to the circumferential intermediate surface of the tire. The fly turn-up 34 was to have a height of 40 to 80% with respect to the tire maximum cross-sectional height. The bead region 35 has a bead core 36 having a high strength steel wire having a diameter of 0.95 to 1.00 mm and a bead filler 37 having a shore A hardness of 40 or more. The belt structure 38 is reinforced by a belt reinforcement layer having a capfly 39 of one layer and an edge ply 44 of one layer on the top thereof, and the cap fly cord 45 in the cap ply 39 has a circumferential direction of the tire. Arranged parallel to.

Example 4

A tire was manufactured in the same manner as in Example 3, except that a cord material for manufacturing a tire was used as the deep cord manufactured according to Example 2.

Comparative example

Comparative Example 3

A tire was manufactured in the same manner as in Example 3, except that the cord material for manufacturing the tire was a deep cord obtained by twisting the polyethylene naphthalate prepared in Comparative Example 1 with 1000 denier / 2 sum.

Comparative Example 4

A tire was manufactured in the same manner as in Example 3, except that the cord material for manufacturing the tire was a deep cord obtained by twisting the polyethylene naphthalate prepared in Comparative Example 2 to 1500 denier / 2 sum.

Comparative Example 5

A tire was manufactured in the same manner as in Example 3, except that a cord material for manufacturing a tire was used by using a deep cord twisted with ordinary nylon 840 denier / 2 sum.

TABLE 2

The 215/60 R15 V tires manufactured according to Examples 3-4 and Comparative Examples 3-5 were mounted on a 2000cc class passenger car, and the noise generated in the vehicle was measured while driving at a speed of 60 km / h. The values are expressed in noise (dB), and the steering stability and ride comfort were evaluated by experienced drivers on a test course in units of 5 out of 100 points, and the results are shown in Table 3 below. Durability is based on FMVSS 109's P-metric tire endurance test method, measuring 38 ° C (± 3 ° C) and 85, 90, 100% of the tire's nominal load. A total of 34 hours, h, beading, side cutting, carcass cord, innerliner, bead, etc. If no trace of bead separation, cord cutting, belt separation, etc. Determined.

TABLE 3

division Example 3 Example 4 Comparative Example 3 Comparative Example 4 Comparative Example 5 Tire weight (kg) 9.70 9.90 9.60 9.89 9.78 Ride 100 100 98 98 95 Steering stability 100 100 98 98 95 durability OK OK OK OK OK Uniformity 100 100 97 97 97 Noise (dB) 61.4 61.8 62.2 62.6 63.2

As a result of the test results of Table 3, the tire according to the present invention (Example 4) has a reduced ride comfort, steering stability, and noise reduction in the case of the present invention using the deep cord manufactured by the present invention in terms of performance. It was found that the effect was excellent on the surface, and the uniformity of the tire was also improved.

The deep cord made of polyethylene naphthalate high strength yarn and polyethylene naphthalate high elongation yarn of the present invention can overcome the disadvantage of low adhesive strength with conventional rubber, and the treatment cord formed from this yarn has excellent adhesion and strength. It can be usefully used as a reinforcement for rubber products such as tires and belts or for other industrial uses.

According to the present invention, by applying a deep cord made of the polyethylene naphthalate high strength yarn and the polyethylene naphthalate high elongation yarn of the present invention to the cap fly layer of a pneumatic radial pneumatic tire for a passenger car, the adhesion to rubber can be improved and the tire Satisfactory results can be obtained for the durability, ride comfort and steering stability.

While the invention has been described in detail in the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (6)

A pair of parallel bead cores; At least one radial carcass fly wound around the bead core; A belt layer laminated on a carcass ply outer circumference; And a belt reinforcing layer in a circumferential direction formed on an outer circumference of the belt layer, the radial pneumatic tire comprising: The capply comprises a dip cord made of a polyethylenenaphthalate high strength yarn having a strength of 9.2 to 9.7 g / d and a polyethylene naphthalate high elongation yarn having an elongation of 10 to 15%, and the dip cord comprises: (1) a strength of 15 to 23 kg; (2) a median elongation of 2.2 to 2.4%; (3) at least 12 kg of adhesion to rubber; (4) at least 85% fatigue resistance; And (5) radial pneumatic tires, characterized by having physical properties of shrinkage of 0.8 to 1.4%. The radial pneumatic tire according to claim 1, wherein the polyethylene naphthalate high strength yarn has physical properties of an intermediate elongation of 2.4 to 3.0% and an elongation of 8 to 10%. The radial pneumatic tire according to claim 1, wherein the polyethylene naphthalate high elongated yarn has physical properties of strength 8.8 to 9.2 g / d and medium elongation 3.0 to 3.5%. The radial pneumatic tire according to claim 1, wherein the fineness of the polyethylene naphthalate high strength yarn and the polyethylene naphthalate high elongation yarn is 500 to 2000, respectively. The radial pneumatic tire according to claim 1, wherein the deep cord has a fineness of 1000 to 6000 denier. The radial pneumatic tire according to claim 1, wherein the cap ply has two layers.

Images