KR100531616B1 - Polyvinyl alcohol fiber having excellent hot water resistance - Google Patents

Abstract

In the present invention, A) Polyvinyl alcohol having a degree of polymerization of 1,500 to 7,000 and a saponification degree of 99.9 mol% or more is dissolved in dimethyl sulfoxide and spun after dry or wet spinning, and the unstretched yarn is an extraction tank containing aromatic dialdehyde and methanol. Penetrating the aromatic dialdehyde into the unstretched yarn by passing through it, followed by stretching at high magnification and then heat-treating; B) imparting twist to the polyvinyl alcohol stretched yarn including the aromatic dialdehyde to produce a lower twisted yarn, and adding the upper twisted yarn by adding two or three lower twisted yarns to produce a raw cord; C) provides a cross-linked raw cord prepared by the method comprising the step of immersing the raw cord comprising the aromatic dialdehyde in an acid to crosslinking treatment. The cross-linked raw cord has hot water resistance and high fatigue resistance of 80% or higher at 150 ° C or higher.

Description

Polyvinyl alcohol fiber having excellent hot water resistance

The present invention relates to a polyvinyl alcohol (hereinafter, abbreviated as PVA) fiber having excellent hot water resistance and high strength fiber property, and a method of manufacturing the same, and more particularly, to dimethyl sulfoxide containing methanol. And dissolve PVA resin of 98% or more of saponification degree, and dry-wet gel spinning with methanol as a coagulation solvent to prepare unstretched yarn, and pass the unstretched yarn through an extraction tank containing aromatic aldehyde and methanol. After infiltrating the aromatic dialdehyde into the unstretched yarn, the polyvinyl alcohol stretched yarn was twisted at high magnification and then subjected to heat treatment to give twisted yarn. After the raw material is added to the raw cord, crosslinking reaction treatment is carried out using acid on the synthetic cord, so that excellent hot water resistance and high strength fiber properties can be exhibited. The present invention relates to a green PVA cord for tire reinforcement and a method of manufacturing the same.

PVA fiber has higher strength and elastic modulus than polyamide, polyester, and polyacrylonitrile fiber, which are general-purpose fibers. Especially, PVA fiber is used as various industrial materials because of its excellent adhesion, water dispersibility, alkali resistance and chemical resistance. .

Recently, it has been used in various ways as reinforcing materials such as concrete and cement reinforcing materials and rubber and plastics, and has been researched and developed as a material having high application potential in new fields.

To date, several methods for obtaining high strength PVA fibers have been introduced.

In US Pat. No. 4,440,711, a high-strength PVA fiber is manufactured by using a gel spinning method (US Pat. No. 4,698,194), which can obtain a high strength fiber through a high magnification stretching process using high molecular weight polyethylene as a raw material. V Gel spinning is a general method for preparing high strength fibers by mixing polymer compounds and solvents to produce a homogeneous solution and stretching them at high magnification while controlling the phase separation and gelation rates in the spinning process.

In addition, a technique for spinning wet and dry spinneret has been published to facilitate the gel spinning method.

Japanese Laid-Open Patent Publication No. 7-109616 has a spinneret having a spinneret diameter (D) of 0.1-1 mm and a spinneret length (L) and a ratio (L / D) of spinneret diameter of 3-20. A method of producing PVA multifilament fibers with a spinneret, wet and dry spinning, tensile strength of 22 g / denier or more, initial elastic modulus of 440 g / denier or more, and single yarn fineness uniformity (CV) value of 5% or less has been published. .

However, although PVA fiber produced by the above method has excellent mechanical properties, the hydrophilic property of PVA resin itself is solubilized in high temperature hot water of 100 ° C. or higher, and the mechanical properties are degraded. There was this.

Although a very small amount of water is present inside the tire, excess water may be introduced when the tire is damaged, and the water may be thermally hydrated when the temperature of the tire rises to about 130 ° C according to high-speed driving. This impairs the stability of the vehicle as it damages the PVA fibers. As a result, ordinary PVA fibers could not be used as a reinforcing material for tires.

In addition, the high crystallinity of PVA fibers reduces fatigue resistance required for tire cords, automobile brake hoses, etc., and therefore, problems must be solved through crosslinking treatment.

Therefore, as a conventional technique for improving the heat and humidity resistance, various methods such as high magnification thermal stretching and heat treatment, acetalization, and crosslinking reaction by acid catalyst have been developed by spinning PVA of high polymerization degree, but problems occur when used at a high temperature of 130 ° C. or higher. .

In particular, the cross-linking technique proposed in the prior art mixed the cross-linking agent in the spinning Dope before the stretching process, or added the cross-linking agent in the extraction process or the emulsion process.

Republic of Korea Patent Publication No. 210727 is a method for producing a polyvinyl alcohol-based fiber having excellent hot water resistance to prepare a yarn containing an acetal compound of aliphatic dialdehyde as a crosslinking agent, and then dry heat-stretched and crosslinked using an acid A method was proposed.

Korean Unexamined Patent Publication No. 96-41438 proposes a method of preparing polyvinyl alcohol fibers having excellent hot water resistance, followed by dry heat stretching of yarns containing ammonium sulfate crosslinking agent, followed by crosslinking treatment.

As described above, the crosslinking technique proposed so far has achieved crosslinking reaction by mixing the crosslinking agent in the spinning Dope before the stretching process or by adding the crosslinking agent in the extraction process or the emulsion process. Such conventional crosslinking treatment methods cause crosslinking reactions in the PVA unstretched yarn to cause crosslinking reactions when hot drawn at a high temperature of 200 ° C. or higher to lower elongation, or to lower the crosslinking efficiency due to volatilization. It is difficult to have hot water resistance.

The present invention relates to a polyvinyl alcohol (hereinafter, abbreviated as PVA) fiber having excellent hot water resistance and high strength fiber property, and a method of manufacturing the same, and more particularly, to dimethyl sulfoxide containing methanol. And dissolve PVA resin of 98% or more of saponification degree, and dry-wet gel spinning with methanol as a coagulation solvent to prepare unstretched yarn, and pass the unstretched yarn through an extraction tank containing aromatic aldehyde and methanol. After infiltrating the aromatic dialdehyde into the unstretched yarn, the polyvinyl alcohol stretched yarn was twisted at high magnification and then subjected to heat treatment to give twisted yarn. After the raw material is added to the raw cord, crosslinking reaction treatment is carried out using acid on the synthetic cord, so that excellent hot water resistance and high strength fiber properties can be exhibited. The technical problem is to provide a green tire reinforcement PVA cord and its manufacturing method.

Accordingly, the present invention,

A) Polyvinyl alcohol having a degree of polymerization of 1,500 to 7,000 and a saponification degree of 99.9 mol% or more is dissolved in dimethyl sulfoxide and spun after wet or wet spinning, and then the unstretched yarn is passed through an extraction tank containing aromatic dialdehyde and methanol. Infiltrating the aromatic dialdehyde into the unstretched yarn, and then stretching it at a high magnification and then heat-treating it;

B) imparting twist to the polyvinyl alcohol stretched yarn including the aromatic dialdehyde to produce a lower twisted yarn, and adding the upper twisted yarn by adding two or three lower twisted yarns to produce a raw cord;

C) provides a cross-linked raw cord prepared by the method comprising the step of immersing the raw cord comprising the aromatic dialdehyde in an acid to crosslinking treatment.

In addition, the crosslinking reaction of step C) is preferably crosslinked by immersing the raw cord in an acid in a state wound in a bobbin.

In addition, it is preferable that the twist number of the lower or upper edge in step B) is 300 to 500 TPM.

In addition, the content of the aromatic dialdehyde compound contained in the unstretched yarn in step A) is preferably 0.5 to 2.0 wt% by weight.

In addition, it is preferable that the aromatic aldehyde contained in the unstretched yarn in step A) is terephthaldicarboxaldehyde.

In addition, the acid catalyst in step C) is preferably acetic acid.

The present invention also provides a deep cord for a cord having the following physical properties, manufactured by treating the cross-linked raw cord with an adhesive liquid (RFL).

(1) cutting load 20.0 to 50.0 kg, (3) fineness 2,000 to 6,000 denier, (4) fatigue resistance more than 80%

In the present invention, the crosslinking agent used in the unstretched yarn may be an aldehyde compound capable of crosslinking reaction with a hydroxyl group of PVA, but a compound having two or more aldehyde groups is preferred to increase crosslinking efficiency. As an aldehyde compound, the aromatic compound which permeates only a fiber amorphous region is preferable.

Such aromatic aldehyde compounds include terephthaldicarboxaldehyde (TDA), isophthaldicarboxaldehyde (IDA), naphthaldicarboxaldehyde (NDA) and the like, and may be used by mixing two or more kinds of aldehyde compounds.

Preferred aromatic aldehyde compounds in the present invention are terephthaldicarboxaldehyde (TDA).

A key technical aspect of the present invention is to use an aromatic aldehyde that can penetrate only to amorphous regions of the stretched yarn as a crosslinking agent. Since the aromatic aldehyde mainly penetrates only to the amorphous region, it is possible to prevent the strong deterioration of the stretched yarn by the crosslinking agent.

The most important feature of the present invention is the crosslinking process. Conventional general crosslinking reactions cause crosslinking by reacting a crosslinking agent with an acid in an unstretched or stretched yarn state. In this way, the undrawn yarn in which the crosslinking reaction is completed deteriorates the drawing workability in the hot drawing step of 200 ° C. or higher temperature, so that the strength of the drawn yarn is not sufficient. In addition, the finished yarn cross-linked reaction is reduced in flexibility resulting in strong damage in the twisting process to give the lower and upper edge.

Therefore, in the present invention, in order to increase the stretchability of the unstretched and to prevent fiber damage in the twisting process, after spinning the polyvinyl alcohol according to dry or wet spinning, the unstretched yarn is extracted with aromatic dialdehyde and methanol. After passing through, the aromatic dialdehyde as a crosslinking agent penetrates into the unstretched yarn and is stretched at a high magnification. The twisted yarn is twisted to prepare a raw cord, and then immersed in an acid to perform crosslinking reaction. PVA raw cords produced by the present invention have a hot water resistance of 150 ° C. or higher and a high fatigue resistance of 80% or more. Such a crosslinking treatment method also serves to improve the workability and productivity by simplifying the overall process.

Hereinafter, the PVA fiber manufacturing method of the present invention will be described in detail as follows.

PVA polymerization degree is about 1,500 to 7,000 is used, preferably high polymerization degree PVA of 1,700 to 3,000 is effective. When the degree of polymerization is less than 1,500, fiber formation is difficult, and when the degree of polymerization is 7,000 or more, the viscosity is so high that spinning processability is poor. High-strength PVA fiber, which is mostly used in the industrial material field, needs hot water resistance, so the saponification degree is higher than 99.9 mol%. Ethylene glycol, glycerin and DMSO may be used as the organic solvent, but DMSO having the best solubility in PVA is suitable. Such DMSO is preferably used to purify the water content to several tens ppm or less.

As for methyl alcohol mixed in DMSO, about 5-40 volume% is used, Preferably it is 10-20 volume%. If the content of methyl alcohol in the solvent is less than 5% by volume, the PVA spinning dope coagulates at 0 ℃ or less, and the gel spinning is impossible. If the volume is above 40%, the spinning dope coagulates, but the entire gel forms a turbidity, forming a uniform gel. I can't. It is preferable to adjust the concentration of PVA Dope so that the viscosity is in the range of 50 to 4,000 Poise, but 500 to 3,000 Poise is effective to obtain excellent physical properties. If the viscosity is 50 or less, it is difficult to form fibers, and at 4,000 or more, the fiber spinning property is poor.

The coagulation bath can spin at a temperature of -30 to 30 ° C, but -10 to 10 ° C is effective for uniform gel formation. If the coagulation bath temperature is -30 ℃ or less, the methyl alcohol content of the solvent should be mixed with 30%, so the PVA dissolving power is lowered, making it impossible to produce a uniform PVA spinning Dope. If the coagulation bath temperature is above 30 ° C, gel formation is impossible and radioactivity is poor.

Subsequent to the coagulation bath, an extraction tank containing aromatic dialdehyde and methanol is provided. The extraction tank serves to penetrate the aromatic dialdehyde crosslinking agent in the unstretched yarn formed in the coagulation tank after spinning.

Preferred aromatic dialdehyde compounds in the present invention are terephthaldicarboxaldehyde (TDA). The crosslinking agent is used in a concentration of 0.1 to 5 wt% with respect to the unstretched yarn, but a range of 0.5 to 2.0 wt% is preferred. If it is less than 0.1wt%, the fatigue resistance is improved, but if the hot water resistance is less than 130 ° C and not more than 5.0wt%, the strong drop is large, making it difficult to use a high strength tire cord.

In order to react the crosslinking compound with the OH group of the PVA, an acid catalyst is required in the aqueous solution of the crosslinking compound. Acids such as sulfuric acid or acetic acid may be used as the acid catalyst, but acetic acid is preferred in view of reaction rate control and stability. The acid catalyst concentration is preferably 5wt% or more with respect to the aqueous solution of the crosslinking compound, but if an appropriate amount is used, it is important to use an appropriate amount because it is difficult to remove in the washing step after the reaction.

PVA fiber manufacturing methods include a dry method, a wet method, and a dry and wet method in which the two methods are mixed. However, the wet and dry method is effective in the high strength PVA fiber manufacturing method requiring a high magnification stretching process. Air-gap can be 10 ~ 300mm in wet and dry method for manufacturing PVA filament, but narrow air-gap of 20 ~ 100mm is preferable for high magnification of thermal stretching. Air-gap is less than 10mm workability. On the other hand, higher than 300 mm thermal crystallization is impossible because the degree of crystallinity is larger than gelation, and the productivity decreases because fusion between fibers occurs at the nozzle cross section.

In the high-strength PVA fiber manufacturing process, the stretching process is very important for improving the high strength and hot water resistance. The heating method of the stretching process includes hot air heating and roller heating, but hot air heating is more effective for producing high strength PVA fibers because the filament is in contact with the roller surface and the fiber surface is easily damaged. Although heating is possible at the temperature of 140-250 degreeC, 160-230 degreeC is preferable. When the heating temperature is below 140 ° C, the molecular chain does not behave sufficiently, so high magnification thermal stretching is impossible, and above 250 ° C, PVA is easily decomposed, resulting in deterioration of physical properties.

Next, high strength and fatigue resistance are required for PVA fibers used as tire cords among industrial materials. For this purpose, raw cords are manufactured by twisting PVA drawn yarns. In the general synthetic fiber twisting process, increasing the number of softening decreases the strength but tends to improve fatigue resistance. Therefore, it is very important to select the appropriate training according to the purpose of use. For example, the tire cord used for the liar tire carcass part is used by giving the number of years of lower and upper edges to 1500d / 2p with 300-500 TPM (twist / M).

A key technical aspect of the present invention is to proceed with the crosslinking reaction after the twisting process. An acid catalyst is added to the raw cord containing the crosslinking agent and crosslinked.

A catalyst is required for the crosslinking reaction to crosslink with the OH group of the PVA. In the present invention, an acid such as sulfuric acid or acetic acid may be used as the acid catalyst, but acetic acid is preferred in consideration of reaction rate control and stability. The acid catalyst concentration is preferably 5wt% or more with respect to the crosslinking agent contained in the unstretched yarn, but if an appropriate amount is used, it is important to use an appropriate amount because it is difficult to remove in the washing process after the reaction.

Another key technical aspect of the present invention is to advance the crosslinking reaction by immersing the raw cord containing the crosslinking agent in the aqueous solution in which the acid catalyst is present.

In order to infiltrate the acid catalyst into the raw cord containing the crosslinking agent, a method of increasing the activity of the crosslinking agent by using the temperature of the aqueous solution at 50 ° C or higher was used, and the reaction vessel was used under pressure. In addition, the cross-linking reaction time is different depending on the cross-linking compound and conditions, but more than 30 minutes is effective, but if the cross-linking reaction for too much time is strongly reduced.

The crosslinked PVA raw cord is dried and heat treated by attaching RFL liquid (hereinafter referred to as "dipping") to clean and dry to improve adhesion to rubber. In more detail, the dipping process is achieved by impregnating the surface of the fiber with a resin layer called Resorcinol- Formaline-Latex (RFL) to improve the disadvantages of fibers for tire cords that are inherently less adhesive with rubber. Is carried out.

In the present invention, as an example of the adhesive liquid for the adhesion of the PVA raw cord and rubber can be prepared and used using the following method. The examples described below are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention.

29.4 wt% Resorcinol 45.6

Pure 255.5

37% formalin 20

10wt% sodium hydroxide 3.8

After preparing the reaction, the reaction was stirred at 25 ° C for 5 hours, and then the following components were added.

40wt% VP-Latex 300

Pure 129

28% ammonia water 23.8

After the ingredient is added, the mixture is aged at 25 degrees for 20 hours to maintain a solid concentration of 19.05%.

In order to prevent the RFL solution from penetrating deeply to the inside of the RFL attachment, a stretch of 0.5 to 3% is given when the RFL solution is attached, and the RFL solution adhesion rate (hereinafter referred to as DPU) is 3.0 to 9.0 wt%. At 0.5% or less stretch, the DPU becomes over 9wt% and penetrates deep into the short fiber to reduce fatigue resistance. In addition, over 3% of the live cord may be over-tensioned, causing damage to the live cord. The heat treatment should be carried out at 170 to 230 ° C., in particular at 200 to 220 ° C. which is the best in PVA molecular motion of the amorphous portion. As a result, high strength PVA deep cords can be manufactured by maximizing the heat treatment effect by minimizing the tension imparted to the fiber to maximize molecular movement. It is important to set the stretch ratio to 0 to -5% in the heat treatment step after immersing the raw cord in the dipping liquid. If the stretch is more than 0% in heat treatment, the deep cord elongation is low, so when used for tire cords requiring high fatigue resistance with less than 60% fatigue resistance, cord breakage or breakage occurs. On the other hand, in the case of -5% or less, recrystallization occurs in a direction perpendicular to the fiber axis due to excessive molecular movement, causing strong degradation. If the crosslinking agent that is not washed in the previous crosslinking step remains inside the fiber, the PVA fiber acts as an impurity in the available product, and thus the crosslinking efficiency may be further improved by reacting or volatilizing the remaining crosslinking agent by heat treatment at 200 ° C. or higher.

Hereinafter, the structure and effects of the present invention will be described in more detail with specific examples and comparative examples, but these examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention. Properties in Examples and Comparatives were evaluated for physical properties in the following manner.

(a) PVA code strong (kgf)

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 was measured at 250 mm and a tensile rate of 300 m / min.

(b) Hot water resistance (WTb, ℃)

Select the stranded raw cord as 3,000 denier, cut it to 4cm and make the load 3g / bone at the end. This is immersed in a pressurized glass container with water, and the temperature at which the fiber is cut is measured while raising the temperature at a rate of 2 ° C / min.

(c) even with fatigue

The fatigue strength of the tire cord was measured using the Goodrich Disc Fatigue Tester, which is commonly used for fatigue testing of tire cords. Fatigue test conditions were 120 ℃, 2500RPM, compression 10% and 18% conditions, and after the fatigue test immersion in Tetra chloro ethylene solution for 24 hours to swell the rubber and to separate the rubber and cord to measure the residual strength. The residual strength was measured according to the method (a) using a conventional tensile strength tester after drying for 2 hours at 107 ° C.

Example 1

PVA used 99.9 mol% and 2,000 respectively in saponification degree and polymerization degree, and methyl alcohol and DMSO used 100ppm or higher purified solvent. A mixed solvent was prepared by mixing DMSO and methyl alcohol so that the content of methyl alcohol in the solvent was 5% by volume, and PVA was dissolved to 22wt% with respect to PVA spinning Dope. Thereafter, PVA fibers were prepared by wet and dry spinning using gel spinning. At this time, the number of nozzle odds and hole diameters were 500 and 0.5 mm, respectively, and a circular nozzle having an L / D of 5 was used. Air-gap was 50 mm and methanol was used as a solvent in the coagulation bath. At this time, the coagulation bath was maintained at a solvent / methanol mixing ratio of 20/80 and a temperature of 0 ° C. The unstretched yarn having passed through the coagulation bath is continuously passed through an extraction tank containing terephthaldicarboxaldehyde and methanol to infiltrate aromatic dialdehyde into the unstretched yarn. After passing through the extraction bath, the PVA fibers should be free of solvent, DMSO. If the solvent remains in the filament is discolored in the hot stretching process is a major cause of the degradation of the physical properties of the final filament. Two stage hot air heating was used for hot drawing. The hot air heating temperature was 200 ℃ for first stage and 220 ℃ for two stages. The draw ratio of each stage was 9.0 times -1.5 times, and the total draw ratio was 13.5 times. As a result, high-strength PVA fibers having a strength of 12.8 g / d and elongation of 7.0% are produced. The raw cord is prepared by twisting the drawn yarn containing such terephthaldicarboxaldehyde to be 360 / 360TMP in each of the lower and upper edges. The raw code strength produced has 32 kgf. The raw cord containing terephthaldicarboxaldehyde wound in bobbin was immersed in an aqueous solution of 15 wt% of acetic acid in water at 70 ° C. for 1 hour for crosslinking reaction, and then washed with water. After crosslinking reaction, PVA deep cord was prepared by impregnating RFC solution with 27kgf of raw cord. The results are shown in Table 1.

[Examples 2 and 3]

The ratio of terephthaldicarboxaldehyde and acetic acid, which is a crosslinking agent, was adjusted in the ratio as shown in Table 1, and the strength and fatigue resistance were compared after the crosslinking treatment.

[Comparative Examples 1 and 2]

In Comparative Example 1, the crosslinking treatment was not performed, and the results are shown in Table 1, and Comparative Example 2 was used to compare the fiber properties when the concentration of terephthaldicarboxaldehyde was used at 2 wt%.

[Comparative Examples 3 and 4]

Comparative Example 3 is shown in Table 1 when the crosslinking reaction was performed for 3 hours. Comparative Example 4 is a case where the reaction temperature is 30 ℃, the results are shown in Table 1.

Table 1

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Cross-linking conditions Terephthaldicarboxaldehyde concentration (wt% / methanol) 10 15 20 - 2 10 10 Acetic acid concentration (wt% / aqueous solution) 15 15 30 - 15 15 15 Reaction temperature (℃) 70 70 70 - 70 70 30 Response time (minutes) 60 60 60 - 60 180 60 Fiber properties Drawn yarn tensile strength (g / d) 12.8 12.2 11.9 13.5 13.1 12.8 12.8 Raw code strong (kgf) 32 31.1 30.8 34 33.1 32 32 Cross-linked cord strength (kgf) 27 26.1 26.1 - 28.9 21.4 31.9 Deep Code Strong (kgf) 33.4 32.4 32.1 38 34.3 25.1 35.1 Fatigue Resistance (%) 97 92 91 62 76 99 67 Hot water resistance (℃) 160 155 165 107 130 170 108

In the present invention, in order to increase the stretchability of the unstretched and to prevent fiber damage in the twisting process, after spinning the polyvinyl alcohol according to wet or wet spinning, the unstretched yarn passes through an extraction tank containing aromatic dialdehyde and methanol. In this case, the aromatic dialdehyde, which is a crosslinking agent, is penetrated into the unstretched yarn and stretched at a high magnification.The twisted yarn is then twisted to prepare a raw cord, and then immersed in an acid to perform crosslinking reaction to exert excellent hot water resistance and high strength fiber property. A tire reinforcement PVA raw cord and a method of manufacturing the same are provided. Such cross-linked raw cord is excellent in hot water resistance and can be suitably used for tire cords.

Claims (7)

A) Polyvinyl alcohol having a degree of polymerization of 1,500 to 7,000 and a saponification degree of 99.9 mol% or more is dissolved in dimethyl sulfoxide and spun after wet or wet spinning, and then the unstretched yarn is passed through an extraction tank containing aromatic dialdehyde and methanol. Infiltrating the aromatic dialdehyde into the unstretched yarn, and then stretching it at a high magnification and then heat-treating it; B) imparting twist to the polyvinyl alcohol stretched yarn including the aromatic dialdehyde to produce a lower twisted yarn, and adding the upper twisted yarn by adding two or three lower twisted yarns to produce a raw cord; C) A cross-linked raw cord prepared by the method comprising the step of immersing the raw cord containing the aromatic dialdehyde in an acid to crosslinking treatment. The method of claim 1, The cross-linking reaction of step C) is cross-linked raw cord, characterized in that the cross-linking reaction by immersing the raw cord in the acid wound in the bobbin. The method of claim 1, Cross-linked raw cord, characterized in that the twist of the lower or upper edge in step B) is 300 ~ 500TPM. The method of claim 1, The cross-linked raw cord, characterized in that the content of the aromatic dialdehyde compound in the non-drawn yarn in step A) is 0.5 to 2.0wt% by weight. The method of claim 1, Cross-linked raw cord, characterized in that the aromatic aldehyde contained in the non-stretched yarn in step A) is terephthaldicarboxaldehyde. The method of claim 1, Cross-linked raw cord, characterized in that the acid catalyst in step C). A cord for a tire cord having the following physical properties, prepared by treating the cross-linked raw cord of claim 1 to an adhesive liquid (RFL). (1) cutting load 20.0 to 50.0 kg, (3) fineness 2,000 to 6,000 denier, (4) fatigue resistance more than 80%