KR20060016538A - Surface treating method and rubber-reinforcement polyester fiber treated using its - Google Patents

Abstract

The present invention relates to a surface treatment method of the polyester fiber for rubber reinforcement and to a polyester fiber for rubber reinforcement treated by the above method, the polyester fiber treated by the surface treatment method of the polyester fiber for rubber reinforcement of the present invention is rubber Excellent adhesion to the, rigidity can be reduced when used as a tire cord to reduce the tire failure rate, because there is no toxic substances or impurities in the treatment process has the effect of improved workability and productivity.

Rubber Reinforcement Fiber, Epoxy, Low Alcohol, Adhesion, Stiffness, Tire Cord

Description

Surface treatment method of the fiber and polyester fiber for rubber reinforcement treated by the above-described method {SURFACE TREATING METHOD AND RUBBER-REINFORCEMENT POLYESTER FIBER TREATED USING ITS}

The present invention relates to a surface treatment method of a polyester fiber for rubber reinforcement for imparting adhesion between rubber and polyester fiber, and a polyester fiber for rubber reinforcement obtained by treating the method.

Rubber is largely divided into natural rubber and synthetic rubber. Since rubber has excellent physical properties such as elasticity, rubber is widely used in modern industrial fields such as tires, belts, and hoses. However, while rubber has excellent elasticity, low mechanical properties such as strength and rigidity are added to supplement the reinforcing material.

The rubber reinforcing material is mainly reinforcing fibers of twisted yarn cord, polyester fibers represented by polyethylene (terephthalate), poly represented by nylon (Nylon) Amide fibers (polyamide fibers), polyvinyl alcohol fibers (poly (vinylalcohol) fibers) and the like are used, of which polyester fibers are most commonly used. However, the reinforcing fibers have poor adhesiveness with the rubber to be applied, and require separate adhesives.

Specifically, polyethylene terephthalate fiber is added as a rubber reinforcing fiber when manufacturing a car tire, which is a rubber product. However, the rubber reinforcing fiber has little compatibility and adhesiveness with a rubber composition forming a tire, and thus has difficulty in manufacturing process. there was.

Therefore, in order to increase the adhesion, the surface of the fiber is introduced into the spinning or stretching process of the rubber reinforcing fiber using an adhesive mainly composed of p-chlorophenol-based resin (PEXUL, capsule), epoxy compound and isocyanate compound. As a result of coating, the adhesion to rubber was improved to some extent. On the basis of this, research on the adhesive of rubber reinforcing fibers is steadily progressing.

In addition, the improvement of the process in addition to the composition of the adhesive is also studied, a method of treating the adhesive at once or several times in multiple stages has been proposed. Recently, a method of treating the adhesive in two steps by changing the composition of the adhesive (double-dipping system) has been generally used.

As an example of such a two-stage treatment method, rubber reinforcing fibers are treated with p-chlorophenol-based resin called PEXUL as the first treatment solution, and then RFL resin is used as the second treatment solution. It is known to process by. At this time, the first treatment liquid is a dispersion of p-chlorophenol-based resin (PEXUL), resorcinol, formalin and rubber latex, the second treatment liquid is a mixture of resorcinol, formalin and rubber latex O / W dispersion (oil-in-water emulsion) obtained by water dispersion is used.

However, since 70% or more of ammonia water is used as a main solvent to disperse the capsules in the first treatment liquid, workability is reduced and contaminated due to the unique smell of the ammonia, and this is caused by the generation of harmful gases during the process. There is a big cost burden, such as the need to install a separate device for processing.

Furthermore, after the impregnation treatment, small gels (GEL), which are dust types, are frequently generated by resorcinol, formalin, and capsules, and the unit weight of the rubber reinforcing fibers used is high, resulting in an increase in the cost burden of the producer and deterioration of physical properties. In addition, the failure rate is high in the production of rubber products such as tires.

As a solution to this problem, U.S. Patent No. 3,234,067 discloses the adhesion of the reinforcing fibers to the rubber by coating the surface of the reinforcing fibers using an adhesive mainly composed of an epoxy compound, an isocyanate compound, and a halogenated phenol compound. It is disclosed that it can be improved. Specifically, the polyester fiber as a reinforcing fiber is treated with a first treatment liquid consisting of a mixture of an isocyanate blocked with an epoxy compound and caprolactam or phenol, and then a second treatment liquid consisting of RFL. A double dipping system is proposed.

As a result, by using the primary treatment liquid containing the epoxy compound, problems such as environmental problems and gel (GEL) generation caused by the use of conventional capsules have been solved. However, due to the strong curing properties of the epoxy compound and the isocyanate compound itself, the stiffness of the polyester fiber obtained after the treatment solution was excessively increased. Due to this increased stiffness, when tires are manufactured using the impregnated polyester fibers, a so-called tip-rise phenomenon, called curl-up phenomenon, occurs, resulting in process defects and finally obtained. Another problem has been raised, such as increased tire failure rates.

Accordingly, although a softner is used in the heat treatment process to lower the stiffness of the impregnated polyester fiber, in order to have the appropriate stiffness of the fiber, excessive use of the softener is required. Curl-up occurred again in the fiber itself. Therefore, there is a need to lower the stiffness of the polyester fiber itself impregnated prior to the softener treatment, rather than the excessive use of additives such as the softener.

In addition, in the double-dipping system as described above, it should be made first to ensure that the first treatment liquid has a high reactivity with the RFL used as the second treatment liquid.

The present invention is to solve the above problems, an object of the present invention is excellent adhesion to rubber, low stiffness (stiffness) can reduce the tire failure rate, since no toxic substances or impurities in the treatment process It is to provide a surface treatment method of a rubber reinforcement polyester fiber having an effect of improving workability and productivity, a primary treatment liquid having excellent dispersion stability used in the treatment method, and polyester fiber for rubber reinforcement. .

In order to achieve the above object, the present invention

a) demineralized water, sorbitol type epoxy, blocked isocyanates, lower alcohols, VP latex (a mixture of vinylpyridine monomer, styrene, and butadiene), and RFL adhesives (lesosinol, formalin) , And a mixture of latex) to prepare a first treatment liquid;

b) passing through the primary treatment liquid while applying a tensile force to the polyester fiber;

c) drying the polyester fibers having passed through the first treatment liquid;

d) stretching the dried polyester fiber by heat treatment at a temperature of 220 to 245 ° C .;

e) passing the heat treated polyester fiber through a RFL adhesive solution, which is a secondary treatment liquid; And

f) It provides a surface treatment method of the polyester fiber for rubber reinforcement comprising the step of drying the polyester fiber passed through the secondary treatment liquid, and stabilizing at a temperature of 220 to 240 ℃.

At this time, it is preferable to perform a rubber reinforcing fiber at a tension of 1.5kg / cord or more during the first dipping process.

And, the drying of the polyester fibers after the first and second treatment liquid is preferably carried out at 140 to 155 ℃.

The present invention also relates to 0.5 to 1.0 parts by weight of sorbitol type epoxy compound, 1.0 to 4.0 parts by weight of blocked isocyanate compound, 1.0 to 6.0 parts by weight of lower alcohol, 0.5 to 1.5 parts by weight of VP latex, and RFL. Provided is a first treatment liquid for surface treatment of a polyester fiber for rubber reinforcement containing 0.1 to 1.0 parts by weight of an adhesive.

The primary treatment liquid may further include a tertiary amine compound, which is a catalyst, and the content thereof is preferably 0.08 to 0.1 parts by weight based on 100 parts by weight of pure water.

The present invention also provides a polyester fiber for rubber reinforcement having an adhesion of 14.0 to 17.0 kgf and a stiffness of 30.0 to 35.0 g / cord processed by the above method.

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

The present invention uses a first treatment liquid mainly composed of an epoxy compound and an isocyanate compound and a second treatment liquid mainly composed of an RFL adhesive in order to impart adhesiveness to the polyester fiber for rubber reinforcement.

In the present invention, the primary treatment solution provides the adhesion between the polyester fiber to be treated and RFL, the secondary treatment solution, and the secondary treatment solution bonds the primary treated polyester with rubber. Play a role.

More detailed components and process conditions of the treatment solution are as follows.

First, in order to prepare the primary treatment liquid composition, 0.5 to 1.0 part by weight of sorbitol type epoxy compound, 1.0 to 4.0 part by weight of blocked isocyanate compound, 1.0 to 6.0 part by weight of lower alcohol, VP latex, based on 100 parts by weight of pure water 0.5 to 1.5 parts by weight, and 0.1 to 1.0 part by weight of the RFL adhesive are mixed.

로 인해 우수한 접착력 및 기계적 물성을 나타낸다. 상기 에폭시 결합은 후속 공정에서 고무 보강 섬유에 처리 후 열 처리 공정에서 상기 섬유의 표면에 존재하는 관능기와 가교 결합되어 상기 고무 보강 섬유의 접착능을 높인다. 이러한 가교 반응을 수행하기 위하여 본 발명의 소르비톨 타입 에폭시 화합물은 1 분자 중에 2 개 이상의 에폭시기를 함유하는 것이 바람직하며, 고온에서 가공 시 상기 화합물 자체가 휘발하는 경우가 있는 바, 그 분자량은 100 달톤(Dalton) 이상으로 하는 것이 바람직하다.The sorbitol type epoxy compound is obtained by reacting a sorbitol alcohol compound with a halogen-containing epoxide compound such as epichlorohydrin, and an epoxy group present in a molecular structure.

Due to its excellent adhesion and mechanical properties. The epoxy bond is crosslinked with a functional group present on the surface of the fiber in the heat treatment step after treatment to the rubber reinforcing fiber in a subsequent process to increase the adhesion of the rubber reinforcing fiber. In order to perform such a crosslinking reaction, the sorbitol type epoxy compound of the present invention preferably contains two or more epoxy groups in one molecule, and the compound itself may volatilize when processed at a high temperature, and its molecular weight is 100 Daltons ( Dalton) or more.

The sorbitol type epoxy compound according to the present invention may be suitably used within the range of the epoxy group and the molecular weight as long as it is commonly used in this field, and is not particularly limited in the present invention, except that the rubber reinforcing fiber is obtained according to the content of the compound. The physical properties of these are different, so their content is controlled.

Accordingly, the content of the sorbitol type epoxy compound of the present invention is 0.5 to 1.0 parts by weight based on 100 parts by weight of pure water. At this time, if the content of the epoxy compound is less than the above range can not expect the desired degree of crosslinking reaction, such as the physical properties such as adhesion of the rubber reinforcement fiber finally obtained is lowered, if exceeding the above range excessive crosslinking as described above Due to the reaction, the adhesion and stiffness of the finally obtained fiber becomes larger than necessary, so that the process is difficult to perform, such as a tip-rise phenomenon or the like.

Then, a blocked isocyanate compound, another component of the present invention, is also added to increase the adhesion of the rubber reinforcing fiber like the sorbitol type epoxy compound, which is also important in addition to the aforementioned sorbitol type epoxy compound. The blocked isocyanate may be one in which the terminal isocyanate group is blocked by caprolactam or phenol.

In the present invention, it is preferable that the isocyanate compound is included in the range of 1.0 to 4.0 parts by weight based on 100 parts by weight of pure water, and when it is out of the range, physical properties such as adhesion of the finally obtained rubber reinforcing fiber are reduced, or excessive curing reaction. As a result, the stiffness of the finally obtained fiber becomes larger than necessary, making the process difficult to perform.

In particular, the sorbitol type epoxy compound and the isocyanate compound contain a large amount of hydroxy functional groups in the molecule, and when the rubber reinforcing fiber is treated with a composition containing such a composition, a covalent bond is present on the surface of the rubber reinforcing fiber. The cross-linking reaction occurs, and when applied to the double-dipping system, the reactivity with the RFL treatment liquid, which is the second treatment liquid treated in the subsequent process, is also increased.

However, the sorbitol type epoxy compound and the isocyanate compound may increase the adhesion of rubber reinforcing fibers to be treated through a large amount of reactive groups, but the compounds are prepared in the form of an aqueous dispersion dispersed in an aqueous solution. Due to the low solubility in aqueous solutions, the dispersion instability of the resulting adhesive composition treatment solution is increased.

When a small amount of the compound is added to solve such solution instability, the desired level of adhesion cannot be obtained. In the present invention, in order to increase dispersion stability of the aqueous dispersion, lower alcohols, preferably methanol, ethanol, propanol and Butanol is added, more preferably methanol and ethanol.

By adding the lower alcohol, the solubility of the sorbitol epoxy compound and the isocyanate compound can be increased to obtain dispersion stability of the adhesive composition prepared in the form of an aqueous dispersion. In the present invention, the content is preferably 100 parts by weight of pure water. It is limited to 1.0 to 6.0 parts by weight.

As a result of preparing an adhesive composition with and without adding ethanol as the lower alcohol in order to examine the dispersion stability according to the addition of the lower alcohol, the former ethanol-containing adhesive composition has a stable dispersion degree in the process line. However, in the latter case, it was confirmed that dispersion stability such as gel generation during the treatment process was very poor.

Next, in addition to the above composition, a VP latex compound in which a vinylpyridine monomer, styrene and butadiene are mixed in a constant ratio is added. When the rubber reinforcing fiber is treated using the adhesive composition of the present invention, the sorbitol type epoxy compound and the isocyanate compound contained in the composition infiltrate a large amount into the fiber in a stretching process or the like. The addition of the VP latex not only prevents the sorbitol type epoxy compound from penetrating the interior of the rubber reinforcing fiber but also increases the viscosity of the final aqueous dispersion.

In the present invention, the content of the VP latex is controlled to 0.5 to 1.5 parts by weight with respect to 100 parts by weight of pure water, and when the content is out of the range, the stiffness and dispersion stability of the obtained rubber reinforcing fiber is lowered, resulting in lower workability or final Product defects will increase.

In particular, the VP latex may cause gelation (gelation) phenomenon over time, in order to prevent this, 0.1 to 1.0 parts by weight of a resorcinol-formaldehyde latex (RFL) compound based on 100 parts by weight of pure water. It is contained.

In addition to the above composition, the present invention adds an amine compound, preferably a tertiary amine compound, as a catalyst for increasing the rate of crosslinking reaction between the sorbitol type epoxy compound and the isocyanate compound and the rubber reinforcing fiber.

The conventionally known primary and secondary amine compounds directly participate in the ring-opening reaction of the sorbitol type epoxy compound to prevent crosslinking between the epoxy compound and the rubber reinforcing fibers, thereby reducing the adhesive strength of the finally obtained rubber reinforcing fibers. In the present invention, tertiary amine compounds are used which can minimize such side reactions.                     

The tertiary amine compound may be trialkylamine and trialcoholamine compounds such as triethylamine and triethanol amine, and may be contained in an amount of 0.08 to 0.1 parts by weight based on 100 parts by weight of pure water. In this case, when the content of the tertiary amine compound is less than the above range, it is not possible to obtain an improvement effect on the crosslinking reaction rate, thereby increasing the standing time of the fiber to be treated. On the other hand, when the content of the tertiary amine compound exceeds the above range, the reaction rate of the epoxy compound contained in the treatment solution is excessively increased, resulting in a drop in the process of the epoxy compound due to excessive crosslinking reaction, thereby greatly reducing the spinning workability. do.

As a result, the adhesive composition of the present invention is obtained in the form of an aqueous dispersion in which sorbitol type epoxy compound, isocyanate compound, lower alcohol, tertiary amine compound, VP latex and RFL compound are dispersed in water at a predetermined concentration.

The method for producing such an adhesive composition follows a method commonly used in the art and is not particularly limited in the present invention. According to a preferred embodiment of the present invention, alcohol, sorbitol-type epoxy compound and tertiary amine compound are injected into the water, dissolved, and then stirred for a predetermined time to obtain a stable dispersion. The isocyanate compound, rubber latex, and RFL compound are added thereto. It can be obtained by adding and stirring again.

The obtained adhesive composition is preferably used for the use of the treatment liquid for improving the adhesion of the rubber reinforcing fibers. The rubber reinforcing fiber is used to increase the physical properties of the rubber product, and is treated with the adhesive composition according to the present invention to include a functional group having an adhesive ability such as epoxy group on the surface of the rubber reinforcing fiber is excellent when mixed with the rubber composition By exhibiting adhesion, the mechanical properties of the rubber composition can be greatly increased.

Such rubber reinforcing fibers may be all fibers commonly used to increase the physical properties of the rubber composition, for example, poly (ethyleneterephthalate) and polybutylene terephthalate (poly (buthyleneterephthalate)) Polyester resins; Polyimide resins; Polyamide resins; And it is selected from the group consisting of poly (vinylalcohol) resins, preferably using a polyester resin.

At this time, the molecular properties of the rubber reinforcing fibers, denier, filament number, cross-sectional shape, yarn properties, fine structure, the presence or absence of additives, polymer properties such as terminal carboxyl concentration, etc. are not particularly limited in the present invention.

In the treatment of the rubber reinforcing fibers using the adhesive composition of the present invention, it is preferable to employ a double-dipping system in which the adhesive treatment agent is carried out in two steps, wherein the adhesive composition is used as the first treatment liquid or the second treatment liquid. It can be used, Preferably it is used as a 1st process liquid, and a following process is briefly demonstrated.

First, when the preparation of the first treatment liquid composition including the composition as described above is finished, it is passed through the prepared first treatment liquid composition while applying a tensile force to the polyester fiber. At this time, the passing speed is preferably 40 to 50 m / min, in order to prevent the treatment liquid composition from penetrating into the polyester fiber, the tensile force is maintained at 1.5 g / cord or more, preferably 2.0 g / Keep above cord.

The polyester fiber passing through the first treatment liquid composition is dried in a drying zone, and the drying temperature is preferably 145 to 155 ° C. The dried polyester fiber is stretched (stretched) by heat treatment at a temperature of 220 to 245 ° C. in a stretching zone. If the heat treatment temperature is less than 220 ℃ dimensional stability of the tire cord is reduced due to lack of thermal history, if it exceeds 245 ℃ polyester fiber is thermally decomposed may deteriorate physical properties such as strength.

At this time, the rubber reinforcing fibers stretched after the heat treatment is 2 to 4 with respect to the weight of the fiber as a solid content of the first treatment liquid in consideration of the reactivity with the first treatment liquid in the subsequent process and the adhesion of the rubber reinforcing fibers. % Is contained.

The heat treated (stretched) polyester fiber is passed through a second treatment liquid containing RFL adhesive as a main component, and the polyester fiber passed through the second treatment liquid is again dried and then stabilized. By stabilizing by heat treatment at a temperature of 220 to 240 ℃ in the normalizing zone, it is possible to impart the adhesive force to the surface of the polyester fiber for rubber reinforcement.

However, the residence time in the stretch area and the stabilization area is preferably 40 to 50 seconds. If the dwell time is less than 40 seconds, sufficient stretching and stabilization effects may not be achieved, and if the dwell time exceeds 50 seconds, the adhesive strength of the polyester fibers may be reduced.                     

The polyester fiber for rubber reinforcement treated through the above process has an adhesive force of 14.0 kgf or more, preferably 14.0 to 17.0 kgf. In addition, the rubber reinforcing polyester has a rigidity of 35.0 g / cord or less, preferably has a rigidity of 30.0 to 35.0 g / cord.

As the secondary treatment liquid used, an adhesive composition generally used is used, and an RFL adhesive composition composed of an initial condensate of resorcinol / formaldehyde and rubber latex is usually used.

Therefore, the polyester fiber for rubber reinforcement treated with the primary treatment liquid composition of the present invention causes environmental problems, workability deterioration, and tire failure, which are problems in using the treatment liquid using a p-chlorophenol-based resin (packet). Suitable for use as a soft polyester tire cord without the problem of gel formation, high cost and tip rise in tire manufacturing due to the high stiffness of epoxy and isocyanate. .

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the following examples are only examples of the present invention, and the present invention is not limited to these examples.

Example 1 Preparation of Polyester Fiber for Rubber Reinforcement

An impregnated polyester cord was prepared by employing a double-dipping system to use the adhesive composition of the present invention as the primary treatment liquid and a conventional RFL adhesive composition as the secondary treatment liquid.                     

Specifically, 5.5 kg of ethanol, 0.8 kg of sorbitol type epoxy compound and 0.1 kg of triethanolamine were dispersed in 88.8 kg of water with a catalyst and aged at 20 ° C. for 4 hours. Subsequently, 3.3 kg of an isocyanate compound was added to the aqueous solution, and then 1.0 kg and 0.5 kg of VP latex and RFL were respectively added, and then aged at 20 ° C. for 1 hour to prepare a primary treatment solution.

1,500 denier / 2-ply of polyester cord for tire reinforcement as a rubber reinforcing fiber was passed through the first treatment liquid at 50 meters per minute so that 1 to 3% of an adhesive composition component was attached, and dried at 150 ° C. for 40 seconds. Subsequently, the polyester fiber was coated with a first treatment liquid by heat treatment at 240 ° C. for 40 seconds.

Subsequently, the dried polyester fiber was passed through the bath containing the secondary treatment liquid in the same manner, and then heat-treated at 240 ° C. for 40 seconds to prepare a polyester fiber for rubber reinforcement.

At this time, RFL 51 obtained by mixing resorcinol, formalin, sodium hydroxide and styrene / 1,3-butadiene / vinylpyridine in a ratio of 15:70:15 in the composition shown in Table 1 as a secondary treatment liquid. The kg was used as an aqueous dispersion dispersed in 49 kg of water.

Raw material name weight% Resorcinol 8.8 Formalin (37%) 4.76 NaOH (10%) 10 Styrene / 1.3-butadiene / vinyl pyridine rubber (41%) 56 water 17.6 * Content ratio = 15:15:70 content ratio

Example 2 Preparation of Polyester Fibers for Rubber Reinforcement

A polyester fiber for rubber reinforcement was prepared in the same manner as in Example 1, except that a small amount of isocyanate blocked with phenol was added to the secondary treatment liquid.

Example 3 Preparation of Polyester Fibers for Rubber Reinforcement

A polyester fiber for rubber reinforcement was prepared in the same manner as in Example 1 except that the amine compound as a catalyst was not used in the first treatment liquid.

Comparative Example 1 Preparation of Polyester Fiber for Rubber Reinforcement

A polyester fiber for rubber reinforcement was prepared in the same manner as in Example 1, except that alcohol and amine compounds were not used in the first treatment solution.

Comparative Example 2: Preparation of Polyester Fiber for Rubber Reinforcement

A polyester fiber for rubber reinforcement was prepared in the same manner as in Example 1 except that no alcohol was used in the first treatment liquid.

Specific matters of the composition applied in Examples 1 to 2 are as shown in Table 2 below.

Treatment solution Composition (% by weight, kg) Example 1 2 to implementation Example 3 Comparative Example 1 Comparative Example 2 Primary treatment liquid Epoxy compound ¹⁾ 0.8 0.8 0.8 0.8 0.8 Isocyanate ²⁾ 3.3 3.3 3.3 3.3 3.3 ethanol 5.5 5.5 5.5 - - Triethylamine 0.1 0.1 - - 0.1 VP latex ³⁾ 1.0 1.0 1.0 1.5 1.5 RFL 0.5 0.5 0.5 1.0 1.0 water 88.8 88.8 88.9 93.4 93.3 Secondary treatment RFL ⁴⁾ 51.0 50.7 51.0 51.0 51.0 Isocyanate - 0.8 - - - water 49.0 48.5 49.0 49.0 49.0 Primary treatment tension (kgf / cord) 2.0 2.0 2.0 2.0 2.0 Temperature (℃) Drying 150 150 150 150 150 stretching 243 243 243 243 243 Normalizing 240 240 240 240 240 1) Sorbitol type epoxy resin 2) Dispersion of phenolic additive of 18% diphenylmethane-4,4'-isocyanate 3) Vinylpyridine monomer / styrene / butadiene content ratio 15:15:70 (40% solution) 4) RFL: Resorcinol / 37% formalin / 10% NaOH / 41% SBR / water = 8.8 / 4.76 / 10/56 / 17.6 (parts by weight)

Test Example

A: Adhesion Test (H-test)

In order to measure the adhesion of the rubber reinforcing polyester fiber obtained in the above Examples and Comparative Examples, a rubber composition having a composition as shown in Table 3 below was treated in accordance with the provisions of ASTM D-2138-72 and 20 kg / cm 2 It was vulcanized at 160 ° C. for 20 minutes at a vulcanization pressure of.

Raw material name Addition amount (part) Styrene-Butadiene Rubber (SBR) 100 Zinc oxide 5 Carbon black 50 Stearic acid One Neutron 60 ^AM 25 Tetra methyl thiurammonosulfide 1.5 2-Mercapto benzothiazole 0.5 Yiwu 1.5

Subsequently, the vulcanized polyester fiber was heat aged and cut in an oven at 150 ° C. for 76 hours to prepare a specimen (3/8 ′), and then drawn at 300 ° C./min at 25 ° C. with Intron. The adhesive force (kgf / 25 mm) was evaluated. The obtained results are as shown in Table 4 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesive force (kgf) ^* 16.1 16.8 14.3 14.4 15.0 Stiffness (g / cord) ^** 33.8 34.1 33.3 30.8 31.8 Primary Treatment Fluid Dispersibility Great Good Good Partial gelation occurs Partial gelation occurs Second Treatment Fluid Dispersibility Good Good Good Good Good Curl-up phenomenon None None None Partial occurrence Partial occurrence *: H-TEST **: ASTM D 885M

According to Table 4, the polyester fiber for rubber reinforcement of the embodiment according to the present invention showed an adhesion of about 14 to 17 kgf, the stiffness of about 33 to 34 g / cord.

Specifically, in the case of Example 2, the isocyanate compound was added to the secondary treatment solution to treat it, but compared with that of Example 1, the adhesion and stiffness increased slightly with addition of the isocyanate, but it was not a significant value.

In addition, in Example 3, the first treatment liquid was treated without adding an amine compound, but compared with Example 1, the reaction rate of the epoxy compound did not increase due to the non-addition of the amine compound acting as a catalyst. As a result, the crosslinking reaction between the epoxy compound and the polyester fiber was small, and thus the adhesion was about 14.3 kgf, which was lower than that of Example 1. However, in terms of stiffness, the values were almost similar.

In comparison, Comparative Examples 1 and 2 without the amine compound and / or alcohol in the primary treatment solution showed about 14-15 kgf of adhesion and 30-32 stiffness (g / cord) under the same treatment conditions. It was.

More specifically, as a result of comparing the comparative examples 1 and 3 to examine the effect of the rubber-reinforced polyester fiber according to the addition of the alcohol, it can be seen that the adhesive strength is almost similar but reduced by about 10% in terms of stiffness there was.

In addition, as a result of comparing Comparative Example 2 and Example 1, it was confirmed that both the adhesive force and the stiffness also decreased.

In particular, in the examples of Comparative Examples 1 and 2, dispersion stability such as partial gelation occurred in the first treatment liquid during the treatment process using the first treatment liquid, and on the contrary, performance of the embodiment according to the present invention was performed. In the case of the first treatment liquid used in the case it was found that the dispersion stability is excellent.

As described above, according to the present invention, an adhesive composition having excellent dispersion stability was obtained, and a polyester fiber for rubber reinforcement having excellent adhesion and stiffness was prepared using the same. As a result, the obtained polyester fiber for rubber reinforcement can effectively increase the physical properties of the rubber composition due to excellent adhesion.

In addition, the adhesive composition is excellent in reactivity with the RFL used as a conventional adhesive treatment agent to facilitate the adoption of a double-dipping system when processing rubber reinforcing fibers.                     

Moreover, as the tip-rise phenomenon does not occur conventionally during the process, not only the defect rate of the final product is lowered but also the curl-up phenomenon of the fiber itself does not occur, and thus the cost reduction effect is suppressed to suppress excessive use of additives. Can be obtained.

Therefore, the polyester fiber treated by the surface treatment method of the rubber reinforcing polyester fiber of the present invention has excellent adhesion to rubber, low rigidity can reduce the tire failure rate when used as a tire cord, toxic in the treatment process Since no substance or impurities are generated, workability and productivity are improved.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (5)

a) demineralized water, sorbitol type epoxy, blocked isocyanates, lower alcohols, VP latex (a mixture of vinylpyridine monomer, styrene, and butadiene), and RFL adhesives (lesosinol, formalin) , And a mixture of latex) to prepare a first treatment liquid; b) passing through the primary treatment liquid while applying a tensile force to the polyester fiber; c) drying the polyester fibers having passed through the first treatment liquid; d) stretching the dried polyester fiber by heat treatment at a temperature of 220 to 245 ° C .; e) passing the heat treated polyester fiber through a RFL adhesive solution, which is a secondary treatment liquid; And f) drying the polyester fiber passed through the secondary treatment solution, and stabilizing at a temperature of 220 to 240 ℃ Surface treatment method of the polyester fiber for rubber reinforcement comprising a.  According to claim 1, wherein the first treatment liquid composition is based on 100 parts by weight of pure water, 0.5 to 1.0 parts by weight of sorbitol type epoxy, 1.0 to 4.0 parts by weight of blocked isocyanate, 1.0 to 6.0 parts by weight lower alcohol, VP latex 0.5 To 1.5 parts by weight, and 0.1 to 1.0 parts by weight of the RFL adhesive. The process according to claim 1 or 2, wherein the lower alcohol is methanol or ethanol. The process according to claim 2, further comprising 0.08 to 0.1 parts by weight of tertiary amine compound, based on 100 parts by weight of pure water. The method of claim 4, wherein the tertiary amine compound is characterized in that at least one compound selected from the group consisting of triethylamine (triethylamine), tripropylamine (tripropylamine), triethanolamine (triethanolamine) and tripropanolamine (tripropanolamine) Adhesive composition made into.