KR20230060216A - Hybrid cord for cap ply and tire comprising the same - Google Patents

Abstract

The present invention discloses a hybrid cord for capply and a tire thereof.
The hybrid cord for cap ply according to the present invention includes a polyurethane under-twisted yarn and a nylon under-twisted yarn, and the polyurethane under-twisted yarn and the nylon under-twisted yarn are performed together, whereby low-speed driving and tire manufacturing process When driving at high speed, the lower twisted yarn is mainly stressed, and when driving at high speed, the lower twisted yarn at high speed is stressed and can resist heat, thereby reducing the fatigue caused by the high heat continuously generated in high speed driving, thereby reducing the risk of accidents. Due to the high characteristics, the ride comfort and handling performance can be enhanced even when the vehicle is running at low and medium speeds.

Description

Hybrid cord for cap ply and tire comprising the same

The present invention relates to a hybrid cord for capply and a tire including the same, and more particularly, during low-speed driving and a tire manufacturing process (particularly, CASE LIFTING), the low-speed lower-twisted yarn mainly receives stress, and during high-speed driving, the high-speed lower-twisted yarn It can resist heat while receiving stress, thereby reducing the fatigue caused by the high heat continuously generated during high-speed driving, thereby reducing the risk of accidents, and because of its high elasticity, the ride comfort and handling performance can be enhanced even during low-medium speed driving. It relates to a hybrid cord for capply that can be used and a tire including the same.

In general, tire cords are used in various ways as a reinforcing material for tires, which is an important factor in maintaining durability and riding comfort of tires.

Tire cords used in recent technologies are polyester, nylon, aramid, rayon, lyocell, etc., and they can be applied in various ways according to the design concept and target performance of the tire.

Recently, as the demand for electric vehicles has greatly increased in the global automobile market, research on reinforcing materials that can withstand high loads and high power, has excellent physical properties such as shape stability, and adhesion between cord and rubber is continuing.

Nylon and aramid are mainly used as materials for tire cords for capply (reference: Korean Patent Publication No. 2009-0164609), and these nylons are easy to mold, have a lower price than other materials, and have excellent adhesive performance and resistance to fatigue. It is applied to most tires because it shows characteristics, but nylon has a low modulus and changes greatly in shape due to temperature changes, so the tire growth rate due to heat and centrifugal force during high-speed driving is high, which can reduce driving stability and durability. .

In addition, since the aramid has a high modulus and a small change in modulus at room temperature and high temperature, steering stability can be improved during high-speed driving, but aramid is relatively difficult to mold due to its high modulus, resulting in poor tire appearance and elongation at break. is low, so the fatigue resistance and durability are low. In addition, there is a problem that ride comfort is reduced.

In order to solve this problem, Republic of Korea Patent Registration No. 1831399, as can be seen in Figure 3, the tread portion 100 in contact with the ground, the side wall portion 200 extending from the tread portion to absorb external force during flexion and extension exercises, side In the tire 10 including the bead part 300 extending from the wall part and supported by the wheel of the vehicle, the carcass ply 400 provided inside the tire and forming the skeleton is turned up and attached while surrounding the bead core 500, , The belt layer 600 is interposed between the tread part and the body ply to disperse the external force rising from the road surface, and an inner liner 700 having airtightness to maintain high pressure inside the tire is provided inside the body ply, Disclosure of an invention for preventing deformation of a belt layer supporting a load of a vehicle during high-speed driving through a cap ply 800 stacked on top of the belt layer 600, an invention using a hybrid cord for such a cap ply Disclosed, which includes a first lower twisted yarn and a second lower twisted yarn simultaneously performed, has an elastic modulus of 40 g/d to 110 g/d in an elongation range of 2% to 4%, and at an elongation of 2% The ratio of the elastic modulus at 4% elongation to the elastic modulus is 104 to 105, and the ratio of the strength at 4% elongation to the stress at 2% elongation is 19 to 21 This improves the steering stability and high-speed durability of the tire.

Therefore, the technical problem to be solved by the present invention is that the low-speed lower-twisted yarn is mainly stressed during low-speed driving and the tire manufacturing process, and the high-speed lower-twisted yarn is mainly stressed during high-speed driving and can resist heat generation, so that it can be continuously operated at high speed It is possible to reduce the risk of accidents by reducing fatigue caused by high heat generated, and to provide a hybrid cord for cab ply and a tire including the same that can enhance ride comfort and handling performance even when driving a vehicle at low and medium speeds due to its high elasticity. .

In order to solve the above-described technical problem, the present invention is a cap ply hybrid cord, comprising a polyurethane lower twisted yarn and a nylon lower twisted yarn, and the polyurethane lower twisted yarn and the nylon lower twisted yarn are performed together. Provides a hybrid cord for fly.

According to another embodiment of the present invention, the polyurethane is a reaction product of polyisocyanate and a polyol, and the polyisocyanate is tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, 4,4-diphenylene methane diisocyanate, 1,5-naphthalene diisocyanate, 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dodecanemethylene diisocyanate, 1,4-diisocyanatocyclohexane, isophorone At least one selected from the group consisting of diisocyanates, and the pollingol is polyisocyanate, ethylene glycol, 1,4 butanediol, 1,5-pentanediol, 1,6hexanediol, polyalkyl It may be at least one selected from the group consisting of rene glycol and polyester polyol.

According to another embodiment of the present invention, the polyurethane lower twisted yarn may have a linear density of 600 to 2200 denier (D).

On the other hand, the present invention provides a tire characterized in that it is manufactured by including the hybrid cord for the cap ply in the cap ply in order to solve the above-described technical problem.

According to the present invention, the low-speed lower-twisted yarn is mainly stressed during low-speed driving and the tire manufacturing process, and the high-speed lower-twisted yarn is mainly stressed during high-speed driving so that it can resist heat generated by high heat continuously generated in high-speed driving Fatigue can be reduced to reduce the risk of accidents, and because of its high elasticity, it can exert the effect of enhancing ride comfort and handling performance even when driving at low and medium speeds.

1 is a diagram showing the appearance of a hybrid cord according to the present invention,
2 is a diagram showing a cross section of the cord of FIG. 1;
3 is a half cross-sectional view of the upper part of a tire showing the location of a conventional cap ply.

Hereinafter, the present invention will be described in more detail.

It should be noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention, and the technical terms used in the present invention are not specifically defined in other meanings in the present invention. Unless otherwise specified, it should be interpreted in a meaning generally understood by those skilled in the art, and should not be interpreted in an excessively comprehensive meaning or in an excessively reduced meaning.

In addition, when the technical terms used in the present invention are incorrect technical terms that do not accurately express the spirit of the present invention, they should be replaced with technical terms that those skilled in the art can correctly understand. In addition, general terms used in the present invention should be interpreted as defined in advance or according to context, and should not be interpreted in an excessively reduced sense.

In addition, the singular expression used in the present invention includes a plurality of expressions unless the context clearly indicates otherwise. It should not be construed as necessarily including all of the various steps, and it should be construed that some components or some steps may not be included, or additional components or steps may be further included.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings, but the same or similar components are given the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

1 is a diagram showing the appearance of a hybrid cord according to the present invention, and FIG. 2 is a diagram showing a cross section of the cord of FIG. 1, which is referred to.

The present invention is a hybrid cord (1) for a cap ply, which includes a polyurethane lower-twisted yarn (2) and a nylon lower-twisted yarn (3), and is characterized in that the polyurethane lower-twisted yarn and the nylon lower-twisted yarn are performed together.

Here, the polyurethane lower-twisted yarn is strong and has high elasticity, so that the nylon lower-twisted yarn and plying are easy.

Primarily twisted yarn means a single yarn made by twisting one filament yarn in either direction, and a plied yarn (plied yarn) means two or more lower-twisted yarns together in one direction. It means twisted yarn.

In addition, the cord includes not only plied yarn, but also a dip cord, which means a plied yarn containing an adhesive that can be directly applied to a rubber semi-finished product. The adhesive-containing fabric produced by doing so is also included in the tire cord.

In addition, twist number means the number of twists per 1 m, and its unit is TPM (Twist Per Meter).

Polyurethane used in the polyurethane undertwisted yarn is not limited to its type as long as it is a material that can resist heat generation while receiving stress mainly during high-speed driving. Polyurethane can be used, and it is a compound in the form of alternating two unit compounds or one of which is interposed between them.

<Formula 1>

(n: integer)

<Formula 2>

(* *unit compound)

In addition, the polyurethane is a reactant of polyisocyanate and polyol, has low intermediate elongation and heat shrinkage, high strength and modulus, excellent form stability, and low moisture content, so even when wet, strength retention and modulus retention are 80% or more. It has strong adhesion and corrosion resistance, so it can solve the disadvantage of low adhesive strength of rubber of existing aramid.

The polyisocyanate is an aliphatic polyisocyanate, which includes tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, 4,4-diphenylene methane diisocyanate, 1,5-naphthalene diisocyanate, 2-methylpentamethylene diisocyanate, It may be at least one polyisocyanate selected from the group consisting of 2,2,4-trimethylhexamethylene diisocyanate, dodecanemethylene diisocyanate, 1,4-diisocyanatocyclohexane, and isophorone diisocyanate.

In addition, the polyol is selected from the group consisting of ethylene glycol, 1,4 butanediol, 1,5-pentanediol, 1,6 hexanediol, polyalkylene glycol, and polyester polyol It can be at least one polyol.

It is preferable to use the polyurethane undertwisted yarn with a linear density of 600 to 2200 denier (D), and if it is less than 600 denier, the green case strength of the finished tire is low due to low tensile strength at break, which is dangerous for durability deterioration. Conversely, if it exceeds 2200 denier, the tensile breaking strength can be sufficiently secured, but the stiffener must be designed to be thick due to the thick cord diameter, which can cause a decrease in fuel efficiency due to an increase in tire weight.

On the other hand, the nylon can be used without limitation as long as it can mainly receive stress during low-speed driving and the tire manufacturing process. For example, nylon 6,6 may be used, and nylon 6,6 has excellent fatigue resistance against bending and Thermal shrinkage due to heat from high-speed running can improve separation resistance of the belt edge portion due to shrinkage of the cap ply.

The nylon undertwisted yarn preferably has a linear density of 400 to 1700 denier (D), and if it is less than 400 denier, heat shrinkage of the cap ply is insufficient to impart separation resistance to the belt reinforcement, and conversely, if it exceeds 1700 denier, the cord diameter ( As the cord diameter increases, the reinforcing material becomes thicker, which may cause a decrease in fuel efficiency due to an increase in tire weight.

As for the linear density relationship between the polyurethane under-twisted yarn and the nylon under-twisted yarn, the ratio of the linear density of the nylon under-twisted yarn to the polyurethane under-twisted yarn is preferably 70% to 100%. If it is less than 70 and exceeds 100, the difference in fiber diameter between nylon and polyurethane This may cause fatigue due to repeated stretching and stretching to accumulate in fibers with a large diameter, which may cause problems in maintaining long-term aging.

The hybrid cord for the cap ply of the polyurethane under-twisted yarn and the nylon under-twisted yarn is for a strong and elastic cap ply cord configuration, and is a cord in which a polyurethane under-twisted yarn and a nylon under-twisted yarn are performed, and the hybrid cord has an intermediate elongation of 3.5 to 6 %, exhibiting Tensile Strength of 13 to 34 kgf. If it is less than 3.5, it may be disadvantageous to the manufacturing process, riding comfort and steering stability, and if it exceeds 6, on the contrary, centrifugal force and heat generated by driving It may be difficult to maintain the growth inhibition function of the tire because of the tire's balance, reducing the rolling resistance and leading to deformation and destruction of the tire.

Since the polyurethane and nylon 6,6 described above show different characteristics in modulus and intermediate elongation (EASL), they may have a complementary relationship with respect to the required performance of the tire.

On the other hand, the tire according to the present invention is characterized in that it is manufactured by including the above-described hybrid cord for the cap ply in the cap ply, and the manufacturing method of the finished product follows a conventional tire manufacturing method.

Examples and Comparative Examples

Hybrid cord embodiments according to the present invention and conventional comparative examples, as shown in Tables 1 and 2 below, nylon 6,6 filament yarn and polyurethane filament yarn are put into a cable cord twisting machine, and the lower edge in the Z direction and the lower edge in the S-direction 2-ply yarn was produced by simultaneously performing upper twisting and upper twisting, and the cable cord twisting machine was set with the number of twists of 300 TPM for lower twisting and upper twisting, and the tension applied to the nylon filament yarn was 52 %, and the tension applied to the polyurethane filament yarn was set at 2.5 position.

The polyurethane used here is synthesized by polymerization of 4,4-diphenylmethane diisocyanate, poly ethylene adipate, and 1,4-butane diol. 0.25 mol of poly ethylene adipate (Mn = 1000), 0.50 mol of 4,4-diphenylmethane diisocyanate and 0.25 mol of 1,4-butane diol were used.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 polyurethane linear density 1000 (PU) 1000 (PU) 840 (N-6,6) 1000 (Aramid) Nylon 6,6 linear density 840 (N-6,6) 1000 (PU) 840 (N-6,6) 840 (N-6,6)

division Example 1 Example 2 Example 3 Example 4 Comparative Example 4 polyurethane linear density 1000 850 840 1500 1500 NYON-6,6 linear density 840 840 630 1260 840 PU to nylon ratio 84% 99% 74% 84% 56%

Experimental example

For the examples and comparative examples according to the present invention, tensile evaluation is based on ASTM D-885 (M) and ASTM-D2256 (M), and heat shrinkage evaluation is based on ASTM-D4974, and the results are shown in Table 3 below. , as shown in 4.

division Example 1 Comparative Example 1 (PU) Comparative Example 2 (Nylon) Comparative Example 3 Tensile Strength 100 141 70 101 Elongation (@break) 100 114 84 31 EASL 100 65 141 87 Thermal Shrinkage 100 56 152 45 E-S stability 100 139 53 134

division Example 1 Example 2 Example 3 Example 4 Comparative Example 4 Strength 100 89 82 150 135 Elongation (@break) 100 99 101 100 103 EASL 100 103 98 100 93 Thermal Shrinkage 100 104 97 100 91 E-S stability 100 97 103 100 108

(Unit: Example 1 is set as 100, and the values of Examples and Comparative Examples are converted into relative values and expressed as exponents)

* Tensile strength refers to the value expressed in kgf as the maximum force required until the cord is pulled and broken.

* Elongation (@break) refers to the percentage (%: (length at cutting/original length) * 100) of the degree of elongation from the original length when the cord is stretched and broken.

* Intermediate elongation (EASL) refers to the value expressed as a percentage (%) of the elongated length of the cord when it reaches the specified tensile force (kgf) while being stretched.

* Thermal Shrinkage refers to the value expressed as a percentage of the length shrunk when the fiber cord is left under a certain temperature, time, and load.

* E-S stability is the sum of intermediate elongation and heat shrinkage, and indicates thermal stability.

Referring to Tables 3 and 4, it can be seen that the hybrid cords according to the examples have strong modulus and are well-balanced in thermal contraction rate and shape stability, thus satisfying the required performance of the finished tire.

In addition, in Examples 1 to 4, there is no bias in the linear density of the lower twisted yarn, and the tensile strength of the hybrid cord is excellent. On the other hand, as in Comparative Example 4, if the ratio of polyurethane and nylon is out of range, fatigue caused by tire driving and repeated bending Since the accumulation is biased, it can be seen that the durability is disadvantageous.

Hybrid cord 1, polyurethane under-twisted yarn 2, nylon under-twisted yarn 3.

Claims (4)

In the hybrid cord for capply,
Polyurethane undertwist yarn: and
Including; nylon lower twisted yarn;
Hybrid cord for cap ply, characterized in that the polyurethane lower twisted yarn and the nylon lower twisted yarn are staged together.
According to claim 1,
The polyurethane is a reaction product of a polyisocyanate and a polyol,
The polyisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, 4,4-diphenylene methane diisocyanate, 1,5-naphthalene diisocyanate, 2-methylpentamethylene diisocyanate, 2,2, At least one selected from the group consisting of 4-trimethylhexamethylene diisocyanate, dodecanemethylene diisocyanate, 1,4-diisocyanatocyclohexane, and isophorone diisocyanate,
The pollingol is a group consisting of polyisocyanate, ethylene glycol, 1,4 butanediol, 1,5-pentanediol, 1,6 hexanediol, polyalkylene glycol, and polyester polyol. Hybrid code for cap fly, characterized in that at least one selected from.
According to claim 1,
The polyurethane lower twisted yarn is a hybrid cord for cap ply, characterized in that the linear density of 600 to 2200 denier (D).
According to claim 1 to 3,
A tire characterized in that manufactured by including the hybrid cord for the cap ply in the cap ply.

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