KR100511724B1 - Devices for crosslinking and process for preparing polyvinyl alcohol fiber using them - Google Patents

Abstract

The present invention relates to a method for producing polyvinyl alcohol fibers, and more particularly, to dissolve PVA resin of 98% or more of saponification degree in dimethyl sulfoxide (hereinafter referred to as DMSO) containing methanol. A twisted yarn was prepared by applying twist to a wet-and-dry gel spinning, stretched and heat treated 1000 to 2000 denier polyvinyl alcohol stretched yarn as a coagulation solvent. After the cord is wound into a bobbin for crosslinking reaction and the crosslinking reaction is carried out by adding alcohol to a crosslinking aqueous solution containing an aromatic aldehyde compound and an acid catalyst, the raw cord wound up in the crosslinking reaction bobbin undergoes a crosslinking reaction. The present invention relates to a crosslinking agent input device capable of effectively inducing a crosslinking reaction of a cord, and a method for producing a heat resistant polyvinyl alcohol fiber using the same.

Description

Crosslinking agent input device and manufacturing method of polyvinyl alcohol fiber using the same {Devices for crosslinking and process for preparing polyvinyl alcohol fiber using them}

The present invention relates to a method for producing polyvinyl alcohol fibers, and more particularly, to dissolve PVA resin of 98% or more of saponification degree in dimethyl sulfoxide (hereinafter referred to as DMSO) containing methanol. A twisted yarn was prepared by applying twist to a wet-and-dry gel spinning, stretched and heat treated 1000 to 2000 denier polyvinyl alcohol stretched yarn as a coagulation solvent. After the cord is wound into a bobbin for crosslinking reaction and the crosslinking reaction is carried out by adding alcohol to a crosslinking aqueous solution containing an aromatic aldehyde compound and an acid catalyst, the raw cord wound up in the crosslinking reaction bobbin undergoes a crosslinking reaction. The present invention relates to a crosslinking agent input device capable of effectively inducing a crosslinking reaction of a cord, and a method for producing a heat resistant polyvinyl alcohol fiber using the same.

Polyvinyl alcohol fibers (hereinafter abbreviated as PVA) exhibit superior strength and elastic modulus compared to general-purpose fibers such as polyamide, polyester, and polyacrylonitrile fibers, and particularly have excellent adhesion, water dispersibility, alkali resistance and chemical resistance. Because of its superiority, it is used as a variety of industrial materials.

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 mixed the crosslinking agent in the spinning Dope before the stretching process or injecting the crosslinking agent in the extraction process or the emulsion process. These conventional cross-linking treatment methods, the cross-linking agent contained in the PVA unstretched yarn causes cross-linking reaction when the heat stretching at a high temperature of 200 ℃ or more to lower the elongation or lower the cross-linking agent having a lower boiling point to reduce the cross-linking efficiency to 130 ℃ or more It is difficult to have hot water resistance.

In addition, the cross-linking method as described above is cross-linked by simply immersing the bobbin wound in the unstretched yarn into the crosslinking agent, so that the cross-linking agent does not penetrate into the unstretched yarn wound inside the bobbin, so that There was a problem that the crosslinking treatment was incomplete, or the crosslinking treatment on the inside and the outside of the undrawn yarn wound on the bobbin were significantly different.

The present invention is to give a twist to the polyvinyl alcohol stretched yarn of 1000 to 2000 denier to produce a low-twisted yarn, the lower twisted yarn is plyed in two or three to add the upper edge to prepare a raw cord and wound in the cross-linking bobbin After the cross-linking reaction is carried out by adding alcohol to the cross-linking aqueous solution containing the aromatic aldehyde compound and the acid catalyst, the raw cord wound up in the cross-linking bobbin is subjected to a crosslinking agent input device to exhibit excellent hot water resistance and high strength fiber properties. And the technical problem to provide a method for producing a heat-resistant polyvinyl alcohol fiber using the same.

Accordingly, the present invention,

Hollow is formed and a plurality of through-holes are formed in the circumferential surface is provided with a cylindrical bobbin shaft for winding the PVA raw cord, a first bobbin having a coupling jaw is formed on the other side of the bobbin shaft, the hollow is formed and the circumferential surface A plurality of through-holes are formed in the cylindrical bobbin shaft to which the PVA raw cord is wound, and a bobbin wheel is coupled to the other side of the bobbin shaft to prevent separation of the PVA raw cord wound around the bobbin shaft. On one side of the hollow shaft is formed in a shape corresponding to the coupling jaw formed in the first bobbin crosslinking reaction bobbin composed of a second bobbin is formed with a coupling groove coupled to the coupling jaw, and the first bobbin hollow on the other side The PVA live cord coupled and wound on the hollow side of the first bobbin wheel and the hollow side of the second bobbin while preventing the separation of the PVA live cord coupled and wound A second bobbin wheel to which the crosslinking agent supply line for supplying the crosslinking agent by pressurizing or depressurizing the crosslinking agent to the hollow inside of the crosslinking reaction bobbin and preventing the separation of the crosslinking agent is filled; It is provided with a cross-linking agent input device, characterized in that the closed container provided to be immersed.

A) dissolving polyvinyl alcohol having a degree of polymerization of 1,500 to 7,000 and a saponification degree of 99.9 mol% or more in dimethyl sulfoxide and spinning according to dry or wet spinning, followed by stretching and then heat-treating the prepared non-stretched yarn at high magnification; B) imparting twist to the polyvinyl alcohol stretched yarn to prepare a lower twisted yarn, and adding the upper twisted yarn to two or three yarns to produce a raw cord; C) provides a cross-linked raw cord prepared by the method comprising the step of adding the alcohol to the cross-linking aqueous solution containing an aromatic aldehyde compound and an acid catalyst to react by the cross-linking device.

In addition, it is preferable that the alcohol added to the crosslinking aqueous solution in step C) is methanol.

In addition, the content of the alcohol added to the crosslinking aqueous solution in the step C) is preferably 1 to 30wt%.

In addition, the content of the aromatic aldehyde compound crosslinked to the raw cord in step C) is preferably 0.5 to 2.0wt% by weight.

In addition, it is preferable that the aromatic aldehyde crosslinked to the raw cord in step C) is terephthaldicarboxaldehyde (TDA).

In addition, in the step C), it is preferable to use an acid catalyst during the crosslinking treatment reaction to the raw cord.

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

In addition, there is provided a deep cord for a tire 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%

The crosslinking agent used in the present invention is an aldehyde compound capable of crosslinking reaction with a hydroxyl group of PVA. In order to increase crosslinking efficiency, a compound having two or more aldehyde groups is preferable. As an aldehyde compound, the aromatic compound which permeates only a fiber amorphous region is more 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. In general, the cross-linking treatment uses a method of dissolving the cross-linking agent in an organic solvent in the extraction process in order to penetrate the cross-linking agent to the inside of the fiber. It does not have sufficient hot water resistance and fatigue resistance. The crosslinking agent used in the extraction process makes it difficult to recover the organic solvent, making the overall process difficult.

Therefore, in the present invention, in order to increase the crosslinking efficiency and prevent fiber damage, the crosslinking agent is penetrated and then crosslinked into the PVA raw cords that are twisted to produce high strength PVA fibers having heat resistance of 150 ° C. or higher and high fatigue resistance of 80% or more.

In the present invention, a key technical matter is to crosslink the raw cord with an alcohol to a crosslinked aqueous solution containing an aromatic aldehyde compound and an acid catalyst. By adding alcohol to the crosslinking solution, it was possible to prevent the significant decrease in strength after the crosslinking reaction.

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 10-20 volume% is effective. 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.

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).

In order to improve the hot water resistance and the fatigue resistance, the PVA raw cords are twisted and reacted with a crosslinking agent.

 In order to penetrate the crosslinking agent only in the amorphous region of the PVA fiber drawn at high magnification, aromatic aldehyde is used as described above as the crosslinking agent.

Preferred aromatic aldehyde compounds in the present invention are terephthaldicarboxaldehyde (TDA). The crosslinking compound is used in a concentration of 0.1 to 5 wt% with respect to the fiber, 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 5 to 30 wt% with respect to the aqueous solution of the crosslinking compound. If it is less than 5 wt%, the crosslinking reaction rate is too slow, and if it is used more than 30 wt%, it is difficult to remove it in the washing process after the reaction.

In the present invention, a key technical matter is to crosslink the raw cord with an alcohol to a crosslinked aqueous solution containing an aromatic aldehyde compound and an acid catalyst. By adding alcohol to the crosslinking solution, it was possible to prevent the significant decrease in strength after the crosslinking reaction.

Preferred alcohols added to the crosslinked aqueous solution in the present invention include methanol, ethanol, propanol, butanol, and the like, more preferably methanol. The wind alcohol to be added is preferably in the range of 1 to 30 wt% based on the crosslinked aqueous solution. If less than 1wt%, the strong deterioration in the crosslinking reaction is large, making it difficult to use high-strength tire cords. If it exceeds 30wt%, the cost is disadvantageous and the crosslinking reaction proceeds too slowly.

Another essential technical matter in the present invention is a polyvinyl alcohol stretched yarn, which is spliced into two or three pieces to prepare a raw cord wound in a crosslinking bobbin, and then crosslinks the raw cord wound in the crosslinking bobbin. It is immersed in liquid and advances a crosslinking reaction.

In order to infiltrate the crosslinking compound into the amorphous region of the highly crystalline PVA fiber, a method of increasing the activity of the crosslinking compound by using a temperature of the reaction 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.

Here, the bobbin for crosslinking reaction used at the time of crosslinking process mentioned above, and its use state are demonstrated briefly.

1 is a perspective view showing a crosslinking bobbin according to the present invention, Figure 2 is a state diagram showing the use of the crosslinking reaction bobbin according to the present invention.

In the crosslinking treatment described above, a crosslinking reaction bobbin 10 is provided, and the crosslinking reaction bobbin 10 includes a first bobbin 10a and the first bobbin forming one side of the crosslinking reaction bobbin 10. A second bobbin (10b) is detachably coupled to (10a) to form the other side of the crosslinking bobbin (10), and the first and second bobbins (10a, 10b) are hollow (16a, 16b), respectively. Are formed, and a plurality of through holes 13a and 13b are formed on the circumferential surface thereof to provide cylindrical bobbin shafts 12a and 12b on which the PVA raw cord 1 is wound, and each of the bobbin shafts 12a and 12b. Opposing outer portions of the first and second bobbin wheels 14a and 14b for preventing separation of the PVA raw cord 1 wound around the bobbin shafts 12a and 12b are coupled to the first and second bobbins 10a. At the inner end of the 10b, a coupling jaw 18a and a coupling groove 18b are formed to couple the first bobbin 10a, the second bobbin 10b to each other.

Here, the first bobbin wheel 14a coupled to the first bobbin 10a is provided to seal one side of the hollow 16a formed by the crosslinking bobbin 10 coupled thereto. The second bobbin wheel 14b coupled to the second bobbin 10b forms the crosslinking agent 2 on the crosslinking reaction bobbin 10 by a supply device for supplying the crosslinking agent 2 at a predetermined pressure. A crosslinking agent supply pipe for supplying the crosslinking agent 2 such that the crosslinking agent 2 is introduced into the PVA raw cord 1 wound on the bobbin 10 for crosslinking by pressurizing or depressurizing the hollows 16a and 16b ( 30) is provided.

Accordingly, the crosslinking bobbin 10 having the PVA raw cord 1 wound thereon is provided in a state in which the crosslinking agent 2 is filled during the crosslinking process and is immersed in the crosslinking agent 2 in the sealed container 40. The crosslinking agent 2 is pressurized or decompressed at a predetermined pressure through the supply line 30, and the supplied crosslinking agent 2 is formed on each bobbin shaft 12a, 12b of the bobbin 10 for crosslinking reaction. It is moved outward from the inside of the PVA raw cord 1 wound through a plurality of through holes 13a and 13b or moved outward from the outside of the PVA raw cord 1 to be wound on the crosslinking bobbin 10. The PVA raw cord 1 can be crosslinked uniformly inside and outside.

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. 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 13.5 g / d and elongation of 8.0% are produced. The twisted yarn is twisted to be 360 / 360TMP in each of the lower and upper edges, thereby producing the twisted yarn. The raw cord strength produced has 34 kgf. The raw cord wound on the crosslinking reaction bobbin is crosslinked by dipping into a terephthaldicarboxaldehyde (TDA), which is an aromatic aldehyde, by a crosslinking agent input device capable of effectively inducing a crosslinking reaction. In the crosslinking treatment, after preparing a crosslinking aqueous solution in which 2 wt% of terephthaldicarboxaldehyde and 10wt% of acetic acid were dissolved in water, 10wt% of methanol was further added to the crosslinking aqueous solution, and the raw cord in the state of being wound on the crosslinking bobbin was After soaking at 70 ° C. for 1 hour, the reaction is followed by washing with water. After crosslinking, strong cord of 33kgf of raw cord was impregnated in RFL solution to prepare PVA deep cord. The results are shown in Table 1.

[Examples 2 and 3]

Terephthaldicarboxaldehyde, acetic acid, and methanol ratio were adjusted in the same ratio as in Table 1 to compare the strength and fatigue resistance after 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 compared with the fiber properties when methanol was not used in the aqueous solution.

[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 The cross-linked raw cord has hot water resistance of 150 ° C. or higher and high fatigue resistance of 80% or more. In order to increase the crosslinking efficiency and prevent fiber damage, twisted polyvinyl alcohol stretched yarn is produced to produce lower twisted yarn. After being wound on, the cross-linked raw cord prepared by the method comprising the step of immersing in aromatic dialdehyde by a cross-linking agent injector capable of effectively inducing the raw cord wound in the cross-linking bobbin for crosslinking reaction treatment. To provide.

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% / aqueous solution) 2 2 2 - 2 2 2 Acetic acid concentration (wt% / aqueous solution) 10 10 15 - 10 10 10 Methanol concentration (wt% / aqueous solution) 10 5 10 - - 10 10 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) 13.5 13.5 13.5 13.5 13.5 13.5 13.5 Raw code strong (kgf) 34 34 34 34 34 34 34 Cross-linked cord strength (kgf) 33.6 32.8 32.1 - 28.2 30.2 33.4 Deep Code Strong (kgf) 37.9 37.2 36.5 38 32.4 34.5 38.2 Fatigue Resistance (%) 99 95 97 62 98 98 68 Hot water resistance (℃) 172 167 172 107 170 171 108

In the present invention, the twisted yarn is prepared by imparting twist to the polyvinyl alcohol stretched yarn of 1000 to 2000 denier, and the lower twisted yarn is spliced into two or three yarns, and the upper edge is added to prepare a raw cord and wound into a crosslinking bobbin. Thereafter, the raw cord wound on the crosslinking bobbin provides a crosslinked raw cord prepared by the method comprising the step of crosslinking the alcohol by adding an alcohol to a crosslinking aqueous solution containing an aromatic aldehyde compound and an acid catalyst. Such cross-linked raw cord is excellent in hot water resistance and can be suitably used for tire cords.

1 is a perspective view showing a bobbin for crosslinking reaction according to the present invention.

Figure 2 is a state of use showing a cross-linking agent input device using a cross-linking bobbin according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: bobbin for crosslinking reaction 12a, 12b: bobbin shaft

13a, 13b: through hole 14a, 14b: bobbin wheel

30: crosslinking agent supply line 40: airtight container

Claims (9)

Hollow is formed and a plurality of through-holes are formed in the circumferential surface is provided with a cylindrical bobbin shaft for winding the PVA raw cord, a first bobbin having a coupling jaw is formed on the other side of the bobbin shaft, the hollow is formed and the circumferential surface A plurality of through-holes are formed in the cylindrical bobbin shaft to which the PVA raw cord is wound, and a bobbin wheel is coupled to the other side of the bobbin shaft to prevent separation of the PVA raw cord wound around the bobbin shaft. A bobbin for a crosslinking reaction, which is formed in a shape corresponding to the coupling jaw formed at the first bobbin on one side of the hollow shaft, and includes a second bobbin having a coupling groove coupled to the coupling jaw; A first bobbin wheel which is coupled to the other side of the first bobbin hollow to prevent detachment of the PVA live cord wound up and at the same time seals the hollow of the crosslinking bobbin; The second bobbin wheel coupled to the hollow one side of the second bobbin to prevent the separation of the PVA live cord wound and at the same time the crosslinking agent supply pipe for supplying the crosslinking agent by pressing or reducing the pressure inside the hollow of the crosslinking reaction bobbin and , Filling the cross-linking agent, the cross-linking agent input device, characterized in that the cross-linking container is provided with a sealed container provided to immerse the cross-linking bobbin. A) dissolving polyvinyl alcohol having a degree of polymerization of 1,500 to 7,000 and a saponification degree of 99.9 mol% or more in dimethyl sulfoxide and spinning according to dry or wet spinning, followed by stretching and then heat-treating the prepared non-stretched yarn at high magnification; B) imparting twist to the polyvinyl alcohol stretched yarn to prepare a lower twisted yarn, and adding the upper twisted yarn to two or three yarns to produce a raw cord; C) The cross-linked raw cord prepared by the method comprising the step of cross-linking the raw code by using a cross-linking agent of claim 1 by adding alcohol to the aqueous cross-linking solution containing an aromatic aldehyde compound and an acid catalyst. The method of claim 2, The cross-linked raw cord, characterized in that the alcohol added to the cross-linking aqueous solution in step C) is methanol. The method of claim 2, Cross-linked raw cord, characterized in that the content of the alcohol added to the cross-linking aqueous solution in step C) is 1 to 30wt%. The method of claim 2, The cross-linked raw cord, characterized in that the content of the aromatic aldehyde compound cross-linked to the raw cord in step C) is 0.5 to 2.0wt% by weight. The method of claim 2, Crosslinked raw cord, characterized in that the aromatic aldehyde cross-linked to the raw cord in step C) is terephthaldicarboxaldehyde (TDA). The method of claim 2, Cross-linked raw cord, characterized in that to use the acid catalyst during the cross-linking treatment reaction to the raw cord in step C). The method of claim 7, wherein 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 2 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%