WO2007119670A1

WO2007119670A1 - Highly heat-resistant polyester fiber material, tire cord, dipped cord, and method for producing highly heat-resistant polyester fiber material

Info

Publication number: WO2007119670A1
Application number: PCT/JP2007/057541
Authority: WO
Inventors: Masanao Kohashi; Kenji Yoshino; Shigenori Nagahara; Yasushi Aikawa; Hirokazu Nishimura; Morihito Tozuka; Norio Iizuka
Original assignee: Toyo Boseki Kabushiki Kaisha
Priority date: 2006-04-13
Filing date: 2007-04-04
Publication date: 2007-10-25
Also published as: JP2007303056A

Abstract

Disclosed is a highly heat-resistant polyester fiber material which is capable of maintaining mechanical characteristics at high temperatures, particularly at a temperature not less than the melting point of the polyester. Also disclosed are a tire cord, a dipped cord and a method for producing a highly heat-resistant polyester fiber material. Specifically disclosed is a highly heat-resistant polyester fiber material which is composed of a polyester fiber containing an ethylene terephthalate unit as a main repeating unit and satisfies the conditions (a) and (b) below at the same time in a dynamic viscoelasticity measurement. (a) Storage modulus at 275˚C (E') ≥ 0.1 MPa (b) Main dispersion peak temperature of loss tangent (tan δ) ≤ 148˚C

Description

Specification

High heat resistant polyester fiber material, tire cord, dip cord, and method for producing high heat resistant polyester fiber material

Technical field

[0001] The present invention relates to a rubber fiber-reinforced polyester fiber material applied to industrial materials such as tire cords, V-belts, conveyor belts, hoses, and the like. More specifically, the present invention relates to a melting point of ordinary polyester at high temperatures. The present invention relates to a polyester fiber material for rubber reinforcement excellent in high heat resistance and capable of maintaining mechanical properties.

Background art

[0002] As typical examples of fibers that are generally used as rubber reinforcing materials, particularly as rubber reinforcing materials for tires, polyester, nylon, and rayon are well known as organic fibers, and inorganic fibers include Typical examples are steel and glass fiber. These materials are used in place due to their inherent properties.

[0003] In recent years, with the progress of the tire structure of Radial Ivy, the demand for high elastic modulus, low shrinkage, fatigue resistance, and low cost has increased for fiber materials used in carcass materials. As a result, polyester fiber rayon is widely used as an alternative to nylon, which is an organic fiber with a good balance in physical properties and cost.

[0004] Further, in recent years, run-flat tires have been developed that can travel at a predetermined speed over a certain distance even when the tire pressure is punctured and the tire internal pressure becomes OkPa. In this run-flat tire, the bead part of the tire side wall is also reinforced by placing a relatively hard rubber layer with a crescent-shaped cross section on the inner surface of the carcass over the shoulder area, and in the tire air chamber. A core type with a metal or synthetic resin ring core attached to the rim is known.

[0005] Of these, the side-reinforcement type supports the load by the inherent rigidity of the sidewall strengthened by the reinforcement rubber layer when the tire punctures and the air escapes during driving, and the predetermined distance is set to a predetermined speed. It is possible to run on. However, if run-flat running is continued, the reinforcing rubber layer generates heat due to repeated compression and expansion, and the tire internal temperature is 200 ° C. It may become extremely hot at or above ° C and even more locally. For this reason, rayon fiber, garamide fiber, steel, etc., which are excellent in heat-melting resistance, are preferred as carcass ply cords for run flat tires!

[0006] On the other hand, tire cords made of polyester fiber or nylon fiber begin to break the adhesion interface with tire rubber at high temperatures of 150 to 200 ° C, and the strength and elastic modulus rapidly decrease, and further exceed the melting point. At higher temperatures, the fiber shape could not be maintained and melt fracture occurred, making it unsuitable as a cord material for run-flat tires. However, since these fibers are characterized by their abundant supply, low price and light weight, in order for runflat tires to become more widespread, tire cords made of polyester fibers or nylon fibers are required. It is desired to use it.

[0007] Various methods for improving the heat resistance of polyester tire cords in tire rubber have been proposed so far. For example, a method for suppressing hydrolysis in rubber by applying a reduction in the amount of carboxylic group ends of polyester fiber (see, for example, Patent Document 1 and Patent Document 2), acrylic acid and Z or methacrylic acid. A method for imparting a strong polymer (for example, see Patent Document 3), a method for containing a fluoropolymer (for example, see Patent Document 4), a method for containing a cyclic olefin polymer (for example, see Patent Document 5) ). However

However, these are all improvements in strength properties related to heat resistance at 150 to 160 ° C., and did not hold the shape above the melting point of the polyester and can maintain the predetermined strength and elastic modulus.

[0008] Patent Document 1: Japanese Patent Laid-Open No. 61-252332

Patent Document 2: JP-A-7-166420

Patent Document 3: Japanese Patent Laid-Open No. 55-166235

Patent Document 4: Japanese Patent Laid-Open No. 6-264307

Patent Document 5: JP-A-8-74126

Disclosure of the invention

Problems to be solved by the invention

[0009] The present invention has been made in view of the above-mentioned problems, and its purpose is usually at high temperatures. The present invention provides a high heat resistant polyester fiber material, a tire cord, a dip cord, and a method for producing a high heat resistant polyester fiber material that can maintain mechanical properties even at a melting point or higher of the polyester.

Means for solving the problem

[0010] As a result of intensive studies conducted by the present inventors to solve the above-mentioned problems, a compound having a specific structure is reacted at the end of the polyester molecular chain, and electron beam irradiation is performed after melt spinning. The present inventors have found that this problem can be solved by forming a crosslinked structure in at least a part of the fiber, and have completed the present invention.

[0011] That is, the present invention is as follows.

[0012] 1. A polyester fiber having an ethylene terephthalate unit as a main repeating unit, which simultaneously satisfies the following characteristics (a) and (b) in dynamic viscoelasticity measurement: material.

(a) Storage elastic modulus at 275 ° C (E,) ≥0. IMPa

(b) Main dispersion peak temperature of loss tangent (tan δ) ≤ 148 ° C

[0013] 2. The high heat-resistant polyester fiber material as described in 1 above, wherein the strength is 4. OcNZdtex or more.

[0014] 3. A polyester tire cord using the high heat-resistant polyester fiber material described in 1 or 2 above.

[0015] 4. A polyester tire cord for a run-flat tire using the high heat-resistant polyester fiber material described in 1 or 2 above.

[0016] 5. A polyester dip cord, wherein the high heat-resistant polyester fiber material according to 1 or 2 is subjected to a dip treatment with a treatment liquid containing at least a resorcin-formaldehyde latex (RFL) mixed solution. .

[0017] 6. The polyester dip cord according to 5 above, which uses a tire cord.

[0018] 7. The polyester dip cord according to 5 above, wherein the tire cord for a run-flat tire is used.

[0019] 8. Unstretched material obtained by blending 0.2 to 3.0% by weight of the following compound 1 in a polyester having ethylene terephthalate units as the main repeating unit, and melt spinning at a spinning speed of 2000 mZ or more. It is characterized by irradiating ionizing radiation to a drawn yarn, a drawn yarn obtained by thermally drawing the undrawn yarn, a twisted cord obtained by twisting one or more drawn yarns, or a woven fabric woven with the twisted cord. Manufacturing method of high heat-resistant polyester fiber material.

[0020] [Chemical 1]

[0021] 9. The method for producing a high heat-resistant polyester fiber material as described in 8 above, wherein the birefringence of the undrawn yarn is 0.04 or more.

[0022] 10. The method for producing a high heat-resistant polyester fiber material as described in 8 or 9 above, wherein the density of the undrawn yarn is 1. 340 gZcm ² or more.

The invention's effect

[0023] According to the present invention, it is possible to provide a highly heat-resistant polyester fiber material for rubber reinforcement capable of retaining mechanical properties at a high temperature, particularly above the melting point of polyester, and a method for producing the same.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. As described above, the present invention is used as a carcass ply cord for a run-flat tire that punctures and lowers the internal pressure, causing the tire internal temperature to be 200 ° C or higher, and locally extremely high temperatures that exceed the melting point of polyester. A high-heat-resistant polyester fiber material with improved heat resistance that can maintain the specified strength and elastic modulus at high temperatures, especially at temperatures above the melting point of ordinary polyester that does not have a crosslinked structure. It is to provide.

The polyester in the present invention includes terephthalic acid as a main acid component, and at least one glycol, preferably ethylene glycol, trimethylene glycol, tetramethylene glycol power, and at least one selected alkylene glycol as a main glycol component. The target is polyester. In addition, it may be a polyester in which a part of terephthalic acid is replaced with another bifunctional carboxylic acid component, and / or a polyester in which a part of the glycol component is replaced with the above-mentioned Daricol or other diol component other than the main component. Even if it is Le. Examples of the bifunctional carboxylic acid other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenol carboxylic acid, diphenoxyethane dicarboxylic acid, β-hydroxyethoxybenzoic acid, ρ-oxybenzoic acid, and azide. Aromatic, aliphatic and alicyclic bifunctional carboxylic acids such as pinic acid, sebacic acid and 1,4-cyclohexanedicarboxylic acid can be mentioned. Examples of the diol component other than the above-mentioned dallicol include aliphatic, alicyclic and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentylglycol bisphenol, bisphenol S, and polyoxyalkylene. A glycol etc. can be mentioned. In addition, the polyester is substantially linear.

Carboxylic acids such as trimellitic acid and pyromellitic acid, polyols such as glycerin, trimethylolpropan, pentaerythritol, tri- or higher functional ester such as 5-hydroxyisophthalic acid and 3,5-dihydroxybenzoic acid Monomers having groups can be used.

[0026] Further, in the polyester, a small amount of any other polymer, acid-fastening agent, radical scavenger, antistatic agent, dyeing improver, dye, pigment, matting agent, fluorescent brightener, Active fine particles may contain other additives.

[0027] As a method for obtaining a strong polyester, it is not necessary to adopt special polymerization conditions. The polycarboxylic acid component and the reaction product of 成分 or an ester-forming derivative thereof and a glycol component are polycondensed into the polyester. Can be synthesized by any method employed in the process. The polymerization apparatus may be a batch type or a continuous type. Furthermore, after the polyester obtained in the liquid phase polycondensation step is granulated and pre-crystallized, it can be subjected to solid phase polymerization at a temperature below the melting point in an inert gas atmosphere or in a vacuum.

[0028] The polymerization catalyst is not particularly limited as long as it has a desired catalytic activity, but an antimony compound, a titanium compound, a germanium compound, and an aluminum compound are preferably used. These catalysts can be used alone or in combination of two or more. The dosage is preferably 0.002 to 0.1 mol% with respect to the carboxylic acid component constituting the polyester.

[0029] In addition, the intrinsic viscosity (IV) of the polyester in the present invention is preferably 0.6 dlZg or more, more preferably 0.8 dlZg or more. If the IV is less than 0.6 dlZg, the decrease in strength and elastic modulus due to thermal degradation of the yarn becomes large, which is not preferable. Further, the amount of carboxyl end groups of the polyester is preferably 50 eqZton or less, more preferably 30 eqZ ton or less. If it exceeds 50eqZton, the heat resistance in the rubber becomes insufficient, and the durability as a tire cord is likely to be insufficient.

[0030] The polyester fiber material of the present invention refers to, for example, a drawn yarn obtained by hot-drawing an undrawn yarn obtained by melt spinning the above polyester, a twisted yarn cord obtained by twisting several strands, or a cocoon made by weaving it. It is a woven fabric. There is no particular upper limit to the number of twisted drawn yarns, but it is usually 10 or less.

[0031] The polyester fiber material of the present invention retains mechanical properties at a temperature equal to or higher than the melting point of ordinary polyester, and has a storage elastic modulus (hereinafter referred to as E ') at 275 ° C in dynamic viscoelasticity measurement. 0. IMPa or more is preferable, 0.5 MPa or more is more preferable, and 1. OMPa or more is more preferable. If E 'at 275 ° C is less than 0. IMPa or less than 275 ° C, it will break in the reinforced rubber. E 'is measured using, for example, DMA-Q800 manufactured by TI'A Instruments Co., Ltd., and the sample is aligned so that the thread length is lcm and 12 OOOdtex, and the initial load is 0.01 N, Minimum Dynamic ForceO. 00001N, ForceTrack 25%, amplitude 10πι, frequency 11Hz, temperature range of 200 ° C to 370 ° C can be measured at a rate of temperature increase of 2 ° CZ. Further, when the sample was melt fractured during the measurement, the temperature was taken as the melt fracture temperature. However, there is no particular upper limit for E ′ at 275 ° C., but it is usually lOOOMPa or less and often lOMPa or less.

[0032] The polyester fiber material of the present invention has a cross-linked structure at least partly between the polyester molecular chains !, and the cross-linked structure is represented by the following chemical formula (1) introduced at the end of the polyester molecule. Formed by reacting the aliphatic unsaturated group of the compound It is preferable. The ionizing radiation is preferably an electron beam or γ-ray having a large irradiation transmission power, but is not limited to these.

[0033] [Chemical 2]

[0034] In addition, it is well known that heat-resistant melting properties are generally improved by forming a cross-linked structure in a polymer, or solubility in a solvent is lowered, and these increase the degree of cross-linking (cross-linking degree). It can be an indicator to show. The heat flow initiation temperature of the polyester fiber material in the present invention is not less than the melting point of the polyester resin before forming the crosslinked structure, preferably 265 ° C or more, more preferably 280 ° C or more, and further preferably 300 ° C. That's it. If it melts and flows at a temperature lower than the melting point, the shape cannot be maintained in the reinforced rubber and breaks, which is not preferable. The heat flow starting temperature can be measured by placing the sample on a hot plate that can be set to a constant temperature for 1 minute, and then determining whether it is hot-melting and flowing or visually.

[0035] The gel fraction indicating the ratio of the insoluble residue to the predetermined solvent is preferably 10% by weight or more, more preferably 20% by weight or more, and still more preferably 30% by weight or more. If the gel fraction is lower than 10% by weight, the degree of cross-linking is too low and the dimensional stability and strength of the tire cord at high temperatures are insufficient, which is preferable! /. The solvent for measuring the gel fraction is not particularly limited as long as it is an organic solvent that completely dissolves the aromatic polyester before forming the crosslinked structure at a predetermined temperature and for a predetermined time. For example, phenol, o chlorophenol, m—Black-mouthed phenol, p Black-mouthed phenol, 2,3-Dichlorophenol, 2,4-Dichlorophenol, 2,5-Dichlorophenol, 2,6-Dichlorophenol, 3,4-Dichlorophenol, 3, 5—Dichroic mouth phenol, 2, 3, 4 Triclo mouth phenol, 2, 3, 5 Triclo mouth phenol, 2, 3, 6 Triclo mouth phenol, 2, 4, 5 Triclo mouth phenol, 2, 4, 6 Trichrome mouth phenol, 3, 4, 5 Triclo mouth phenol, 1, 1, 1, 2, 2-tetrachloro mouth ethane, 1, 1, 2, 2-tetrachloroethane, chlorohonolem, dichloromethane, carbon tetrachloride, dichloroacetic acid, helium Xafluoroisopropanol and the like can be exemplified, and these can be used alone or in combination of two or more. The temperature of the solvent at the time of dissolution is not particularly limited, but is, for example, 20 ° C to 200 ° C. The dissolution time is not particularly limited, but may be 10 minutes to 5 hours as long as it takes time for dissolution to reach a saturated state.

[0036] Furthermore, the polyester fiber material of the present invention preferably has a main dispersion peak temperature (hereinafter referred to as Ta) force of tan δ of 148 ° C or less in the dynamic viscoelasticity measurement of a drawn yarn at 110 Hz. More preferably, it is 147 ° C or lower. When To is higher than 148 ° C, the high elastic modulus and low shrinkage required for the tire cord, especially the carcass ply cord, are not sufficient. Here, Τα is an index indicating the degree of microstructural amorphous chain restraint, and a low α means that amorphous chain restraint is weak, and as a result, excellent thermal dimensions. Stability is developed. The drawn yarn with a To of 148 ° C or lower of the present application is, for example, a highly oriented undrawn yarn (so-called POY) taken at a relatively high spinning speed of 2000 mZ or more, which will be described later, 1.5 to 3.0 times. Low grade

It can be obtained by hot drawing at a draw ratio.

[0037] The polyester fiber material in the present invention is, for example, added to the polyester mainly composed of ethylene terephthalate units with the compound represented by the chemical formula (1) at an arbitrary position in the ethanol feed port or the melt extrusion process. Then, the force obtained by melt spinning may be preliminarily melt-kneaded and pelletized by a known method and used for melt spinning. Further, this kneaded resin can be used as a master batch by blending with polyester resin. The temperature at the time of melt-kneading is not particularly limited as long as it is substantially equal to or higher than the melting point of the polyester. However, if the temperature is excessively high, the polymer chain is broken due to thermal degradation, which is not preferable. The melting point is preferably in the range of (melting point + 70 ° C). Also, the time for melt kneading is not particularly limited, but is 1 minute to 40 minutes, preferably 2 minutes to 20 minutes.

In the present invention, the compounding amount of the compound represented by the chemical formula (1) with respect to the polyester is preferably 0.2 to 3.0% by weight. More preferably, it is 0.4 to 2.5% by weight. Arrangement If the total amount is less than 0.2% by weight, it is difficult to maintain the mechanical properties above the melting point where the cross-linked structure developed after irradiation with ionizing radiation is not sufficient, which is not preferable. Since this property is basically proportional to the content of the compound represented by the chemical formula (1), sufficient thermodynamic properties can be imparted by increasing the blending amount. However, if the blending amount exceeds 3.0% by weight, the spinnability is lowered, and it is difficult to obtain a spinning speed for realizing high elastic modulus and low shrinkage. Furthermore, it is difficult to obtain a high draw ratio and to obtain high strength. This is because an excess of the compound represented by the chemical formula (1) is crosslinked by heat during spinning to form a gelled product. When gelled products are generated, it becomes difficult to produce industrially stable production. Note that the content can be determined by, for example, H-NMR measurement and IR measurement before being irradiated with ionizing radiation. However, it is not limited to these measurements as long as the content of the compound represented by the chemical formula (1) can be determined.

The compound represented by the chemical formula (1) reacts with the epoxy group and the carboxyl group terminal of the polyester by melt-kneading with the polyester, and a catalyst for promoting this reaction may be added simultaneously. Examples of the catalyst that are not particularly limited include alkali metal compounds represented by sodium acetate, potassium acetate, lithium acetate, sodium stearate, potassium stearate, lithium stearate, barium acetate, magnesium acetate, Alkaline earth metal compounds represented by strontium acetate, barium stearate, magnesium stearate, strontium stearate, etc., triethylamine, tributylamine, trihexylamine, triethanolamine, triethylenediamine, dimethylbenzyl Tertiary amines such as amine, pyridine and picoline, imidazole compounds such as 2-methylimidazole, 2-ethylimidazole and 2-isopropylimidazole, tetramethylammonium chloride, Quaternary ammonium salts such as laethylammonium chloride, trimethylbenzylammonium chloride, triethylbenzylammonium chloride, phosphine compounds such as trimethylphosphine, triethylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tetramethylphosphine Honium bromide, tetrabutinorephosphonium bromide, tetraphenolinophosphonium Phosphorus salts such as bromide, triphenyl-pentyl phosphomubromide, phosphate esters such as trimethinophosphate, triethinorephosphate, tribubutinorephosphate, triphenylenophosphate, oxalic acid, p-toluenesulfonic acid, dino -Organic acids such as lunaphthalene disulfonic acid and dodecylbenzene sulfonic acid, and Lewis acids such as boron trifluoride, aluminum tetrachloride, titanium tetrachloride and tin tetrachloride. These can be used alone or in combination of two or more. During ~

However, it is preferable to use an alkali metal compound, an alkaline earth metal compound, a phosphine compound, or an ester phosphate compound. The addition amount of the catalyst is not particularly limited, but 0.001 to 1 part by weight is preferable with respect to 100 parts by weight of the polyester, and further 0.01 to 0.5 part by weight.

[0040] In the present invention, it is preferred that a crosslinking group is introduced by the reaction of the compound represented by the chemical formula (1) with the carboxyl group terminal of the polyester. This also contributes to improved heat resistance. That is, the carboxyl group terminal of the polyester fiber material is considered to cause the degradation reaction of the polyester by autocatalysis in the rubber. This degradation reaction is also caused by blocking the carboxyl group terminal by the reaction of the above compound. It can be suppressed.

[0041] For example, a polyester containing a compound represented by the chemical formula (1) melt-kneaded by an etastruder is melted and discharged from a spinneret, and then cooled and solidified by cooling air in a spinning cylinder, and the spinning speed It is taken over at 2000 mZ or more, preferably 2500 mZ or more. This yarn is referred to as an undrawn yarn. A spinning speed of 2000 mZ or less is not preferable because sufficient spinning stress cannot be applied to promote orientation crystallization during spinning. However, if the spinning speed becomes too high, the unstretched birefringence and density become excessively large, so it is difficult to stretch and it is difficult to obtain high strength, so it is preferable to keep it at 6000 mZ or less, more preferably 4500 mZ or less. It is. Further, the birefringence of the obtained undrawn yarn is desirably 0.04 or more, preferably 0.05 or more, and more preferably 0.06 or more. A birefringence of less than 0.04 is not preferable because the high elastic modulus and low shrinkage required for tire cords, especially carcass ply cords, are insufficient. However, if the birefringence of the undrawn yarn becomes too large, it becomes difficult to draw and high strength can be obtained. It is preferable to keep it as below! /.

[0042] The density of the undrawn yarn is preferably 1.340 g / cm ² or more. More preferably, it is 1.345 gZcm ² or more, more preferably 1.350 gZcm ² or more. When the density is less than 1.340 gZcm ² , the high elastic modulus and low shrinkage are not sufficiently exhibited. However, if the density of the undrawn yarn becomes too high, it becomes difficult to draw and it becomes difficult to obtain high strength. The temperature of the cooling air is not particularly limited as long as it satisfies the desired birefringence and density, but is preferably 20 to 80 ° C, more preferably 40 to 70. C.

[0043] A drawn yarn can be obtained by drawing the undrawn yarn that has been taken up by heat drawing by the force of scooping once or by the spin draw method of drawing continuously after spinning. Hot stretching is performed by high-strength one-stage stretching or two-stage or more multi-stage stretching. The heating method includes a method using a heating roller, superheated steam, a heat plate, a heat box, etc., and is not particularly limited. The draw ratio can be drawn at any value depending on the desired physical properties, but is preferably 1.5 to 3.0 times.

[0044] The drawn yarn obtained in this manner is 10 to 10 cm per 10 cm in accordance with a conventional method: After applying LOO twists (bottom twist), a plurality of yarns are combined and 10 to 10 cm per 10 cm in the opposite direction: Use LOO twists (upper twist) to make twisted cords (raw cords). Furthermore, a woven fabric (raw fabric) can be obtained from this twisted cord according to a conventional method. Although the total number of twisted yarns is not particularly limited, it can be said that it is usually 10 or less.

[0045] The cross-linked structure of the polyester fiber material in the present invention is, for example, a structure resulting from the aliphatic unsaturated group of the compound represented by the chemical formula (1) introduced into the terminal end of the polyester molecule. Is preferably formed by irradiation with ionizing radiation. As ionizing radiation,

Electron beams and γ-rays having high radiation transmission power are preferable, but not limited thereto. This ionizing radiation can be applied in any process from the spinning process of the polyester fiber to the manufacturing process of the dip counter. However, in terms of irradiation efficiency and quality stability, undrawn yarn or LV, preferably irradiated in the state of drawn yarn or twisted cord or woven fabric. The dose of ionizing radiation is not particularly limited as long as it satisfies the desired physical properties. Although not, it is 20 to 3000 kGy, preferably 50 to 1500 kGy. If the irradiation dose is too low, the degree of cross-linking becomes insufficient, and if it is too high, the polyester is decomposed and the strength properties are reduced, which is preferable. The irradiation process is generally performed at room temperature, but can be performed in any temperature environment of 0 to 200 ° C. The atmosphere gas may be air or an inert gas, but is preferably irradiated in an inert gas since oxygen may inhibit the crosslinking reaction.

[0046] The strength of the polyester fiber material in the present invention is preferably 4. OcNZdtex or more. More preferably 5 cNZdtex, and still more preferably 6. OcNZdtex or more. If the strength is lower than 4. OcNZdtex, not only the physical properties of the final product but also the processability in the production process is lowered, which is not preferable. A force that can be said to be better as the strength is higher. Usually less than lOcNZ dtex.

[0047] Further, the polyester fiber material in the present invention can be subjected to a dip treatment for imparting adhesiveness to rubber to obtain a dip cord or a dip anti-dip. As the dip treatment liquid, a treatment liquid containing at least a resorcinol formaldehyde latex (RFL) mixed liquid is preferably used. The details of the dip treatment are those described in JP-A 2006-2327.

Example

[0048] Hereinafter, the ability to more specifically describe the present invention by way of examples. The present invention is not limited to these examples. In addition, the evaluation method of various characteristics followed the following.

[0049] (1) Dynamic viscoelasticity

a.Storage modulus (Ε ')

Using a DMA-Q800 manufactured by A'Instrument Co., Ltd., a sample aligned to a yarn length of 1cm and 12000dtex was loaded with an initial load of O. 01N, Minimum Dynamic ForceO. 0 0001N, ForceTrackl 25%, amplitude 10 200 under the conditions of / ζ πι and frequency 11Hz. The temperature range from C to 370 ° C was measured at a rate of temperature increase of 2 ° CZ, and the storage elastic modulus (Ε ') was determined. If the sample melts and breaks during measurement,

The temperature was defined as the melt fracture temperature (° C).

In addition, the measurement sample shall use untwisted drawn yarn, In such a case, each sample is untwisted, etc., and returned to the state of an untwisted drawn yarn to be used as a sample. b. Main dispersion peak temperature of loss tangent (tan δ)

Using a DMA-Q800 manufactured by A'Instrument Co., Ltd., a sample aligned to a thread length of 2 cm and 1500 dtex was prepared using an initial load of 0.049 N, Minimum Dynamic ForceO. 0 0001 N, Force Track 250%, and amplitude. 30 under conditions of 10 μm and a frequency of 110 Hz. The temperature range of C to 200 ° C was measured at a rate of temperature increase of 2 ° CZ, and the main dispersion peak temperature of the loss tangent (tan δ) was determined.

The measurement sample shall be untwisted drawn yarn, and in the case of twisted cords or woven fabrics, each shall be untwisted and returned to the state of untwisted drawn yarn.

[0050] (2) Gel fraction

Add 25ml of parachlorophenol Zl, 1, 2, 2-tetrachlorophethane ethane = 3Z1 mixed solvent to sample 0. lg (weighed), soak for 100 minutes at 90 ° C, then 30 minutes at 30 ° C

The residue obtained by suction filtration with a glass filter was dried under reduced pressure, and the weight percent of the insoluble matter was defined as the gel fraction (%).

[0051] (3) Strength

Measure the stress-strain curve under the conditions of 20 ° C ambient temperature and 65% relative humidity under the conditions of a specimen length of 20mm (length between chucks), elongation speed of 100% Z using “Tensilon” manufactured by Orientix. The value obtained by dividing the stress at the breaking point by the fineness was obtained as the strength (cNZdtex). Each value was the average of 5 measurements.

[0052] (4) Intrinsic viscosity [IV]

The polymer was dissolved in a mixed solvent of parachlorophenol Zl, 1, 2, 2-tetrachlorophthane = 3/1 at a concentration of 0.4 gZdl and measured at 30 ° C (dlZg).

[0053] (5) Melting point

Accompanying the melting of a 10 mg sample in a nitrogen stream using a differential scanning calorimeter Mac Science DSC 3100 S with an exothermic / endothermic curve (DSC curve) measured at a rate of 20 ° CZ. The peak temperature of the endothermic peak was defined as the melting point Tm (° C). [0054] (6) Birefringence

Using a deflection microscope, the measurement was performed by the Belek Compensator method.

[0055] (7) Density

Measurement was performed at 30 ° C. by a density gradient tube method using an aqueous calcium nitrate solution.

[0056] (8) Spinning status

The spinning situation was evaluated on the basis of yarn breakage. Yes, when stable take-up is possible without thread breakage for more than 1 hour. Sampling is possible. △: Case where thread breakage occurs in less than 1 hour. When it was impossible, X was assigned.

[0057] (9) Dip code strength

JIS—L1017 compliant, temperature-humidity controlled at 20 ° C and 65% RH for 24 hours or longer, and then strong with a tensile tester. 2. Elongation under load of OcNZdtex (hereinafter referred to as intermediate elongation) The cutting elongation was measured. Here, the cord strength is a value obtained by dividing the cord strength by the reference fineness in the cord configuration. For example, if two yarns of 1440dtex are twisted, the standard fineness is 2880dtex, and the intermediate elongation is 57.6N.

[0058] (10) Dip code shrinkage

In accordance with JIS-L1017, after standing for 24 hours or more in a temperature-controlled room at 20 ° C and 65% RH, heat treatment is performed at 150 ° C for 30 minutes without load in the dryer. It was calculated from the difference in test length before and after the reason.

[0059] (11) Dip code dimensional stability index

The sum of the intermediate elongation and shrinkage of the dip cord was used as an index of dimensional stability. This value is small

V ヽ means that dimensional stability is excellent.

[0060] (Examples 1 to 3)

Take 100 mol parts of terephthalic acid, 200 mol parts of ethylene glycol, 0.025 monolayer of antimony trioxide and 0.3 monolayer of stabilizer as stabilizer, and dehydrate for 150 minutes at 250 ° C, internal pressure of 2.5 kgZcm2. Reaction was performed. Thereafter, the temperature was gradually increased and the pressure was reduced, and a polycondensation reaction was performed at 275 ° C. and 0.1 mmHg to a predetermined torque. After completion of the reaction, the polymer was chipped according to a conventional method, and further solid phase polymerization was performed under a vacuum of 230 ° C and 0. OlmmHg to obtain a polyethylene terephthalate chip having an intrinsic viscosity of 1.05. Always use this tip After drying according to the method, diaryl monoglycidyl isocyanurate fed to the melt extruder and heated to 50-60 ° C. at the same time from the etastruder inlet to the polymer is 0.5 in Example 1. It was added at a constant flow rate so that it was 1.5% by weight in Example 2, 1.3% by weight in Example 2, and 2.5% by weight in Example 3. The kneaded polymer was ejected from a spinneret at 310 ° C with 336 orifices with a hole diameter of 0.5 mm, cooled and solidified with a cooling air of 70 ° C, 1. OmZsec, and after spinning, the spinning speed was 3000 mZ. Takes in minutes and does not wind up 1.30 times at 70 ° C, 1st drawing temperature, 1.31 times at 90 ° C, 2nd drawing temperature, heat treatment at 210 ° C, then 4.0 at 130 ° C 4.0 % Relaxation treatment was performed to obtain a 1440 dtex, 336 filament drawn yarn. The drawn yarn was irradiated with an electron beam with an acceleration voltage of 300 keV under a constant tension in a nitrogen atmosphere at 500 kGy. The results are shown in Table 1. In the dynamic viscoelasticity measurement, E 'is kept at 0. IMPa or higher without melting and breaking even at a temperature of 275 ° C or higher.

However, it was divided. Furthermore, from the comparison of Examples 1, 2, and 3, by increasing the blending amount of diallyl monoglycidyl isocyanurate, E 'at 275 ° C can be increased and the melt fracture temperature can be increased. I was divided.

[0061] Next, two drawn yarns after the electron beam irradiation were twisted together to obtain 1440dtexZ2, twist number 43

A raw code of X 43 (t / 10cm) was obtained.

Furthermore, in order to give the green cord adhesion to rubber, the cord is immersed in a mixed solution of a blocked isocyanate solution and chlorophenol'resorcin formaldehyde (RF) as a first treatment liquid. Then, it was dried in an oven at 120 ° C for 56 seconds, and then heat-treated in an oven at 235 ° C for 45 seconds while applying a tension of 0.5 cNZdtex. Subsequently, the cord was dipped in a mixed solution of resorcinol-formaldehyde-latex (RFL), aqueous solution of blocked isocyanate, and aqueous dispersion of epoxy compound as the second treatment liquid, and then dried in an oven at 120 ° C for 56 seconds. Then, heat treatment was performed in an oven at 235 ° C. for 45 seconds while applying a tension of 0.5 cNZdtex to obtain a dip cord.

[Example 4]

A drawn yarn, a drawn yarn after electron beam irradiation, and a dip cord were obtained in the same manner as in Example 1 except that the spinning speed was 2200 mZ, the one-stage draw ratio was 1.50 times, and the two-stage draw ratio was 1.33 times. It was. Table 1 shows the results. There is no significant difference in E 'at 275 ° C, but D It was found that the dimensional stability of was slightly deteriorated.

[0063] (Example 5)

Table 1 shows the results of Example 1 where the electron beam dose was lOOOkGy. Compared to Example 1, the strength was slightly decreased, but it was found that E ′ at 275 ° C. was increased.

[0064] (Comparative Example 1)

A drawn yarn, a drawn yarn after electron beam irradiation, and a dip cord were obtained in the same manner as in Example 1 except that diaryl monoglycidyl isocyanurate was not added. The results are shown in Table 1. It was found that melt fracture occurred at 268 ° C, and that E 'at 275 ° C could not be maintained even when ordinary polyethylene terephthalate fiber was irradiated with an electron beam of lOOOkGy.

[0065] (Comparative Example 2)

In Example 1, the result of not irradiating the electron beam is shown in Table 1. It was found that melt fracture occurred at 268 ° C, and E 'at 275 ° C could not be maintained.

[0066] (Comparative Example 3)

A drawn yarn, a drawn yarn after electron beam irradiation, and a dip cord were obtained in the same manner as in Example 1 except that the spinning speed was 500 mZ, the one-stage draw ratio was 3.5 times, and the two-stage draw ratio was 1.23 times. . Table 1 shows the results. There is no significant difference in E 'at 275 ° C, but Τα rises to 150 ° C and

The dimensional stability of the zip cord was greatly reduced.

[0067] (Comparative Example 4)

Diaryl monoglycidyl isocyanurate was adjusted to 3.5% by weight with respect to the polymer, and melt extrusion was performed. However, smoke and thread breakage occurred frequently, and stable winding was impossible.

[0068] [Table 1]

Industrial applicability

The high heat-resistant polyester fiber material of the present invention is characterized in that it has a cross-linked structure in at least a part between polyester molecular chains, and has mechanical properties that do not melt even at high temperatures above the melting point of polyester. Therefore, it is suitable for rubber reinforcement applications exposed to high temperatures, particularly for tire cords for run-flat tires.

Claims

The scope of the claims

[1] A high-heat-resistant polyester fiber material, which is a polyester fiber having ethylene terephthalate units as main repeating units and simultaneously satisfies the following characteristics (a) and (b) in dynamic viscoelasticity measurement.

(a) Storage elastic modulus at 275 ° C (E,) ≥0. IMPa

(b) Loss tangent (tan δ) main dispersion peak temperature ≤ 148 ° C

[2] The heat-resistant polyester fiber material according to claim 1, having a strength of 4. OcNZdtex or more.

[3] A polyester tire cord using the high heat-resistant polyester fiber material according to claim 1 or 2.

[4] A polyester tire cord for a run-flat tire using the high heat-resistant polyester fiber material according to claim 1 or 2.

[5] A polyester dip cord, wherein the highly heat-resistant polyester fiber material according to claim 1 or 2 is subjected to a dip treatment with a treatment liquid containing at least a resorcin-formaldehyde latex (RFL) mixed liquid.

[6] The polyester dip cord according to claim 5, which is used for a tire cord.

[7] The polyester date cord according to claim 5, which is used for a tire cord for a run-flat tire.

[8] An undrawn yarn obtained by blending 0.2 to 3.0% by weight of the following compound 1 with a polyester having ethylene terephthalate units as a main repeating unit and melt-spun at a spinning speed of 2000 mZ or more, and the undrawn yarn A method for producing a highly heat-resistant polyester fiber material, characterized by irradiating ionizing radiation to a hot-drawn drawn yarn, a twisted cord obtained by twisting one or more of the drawn yarns, or a woven fabric woven with the twisted cord.

[Chemical 1] o 丫 N 丫.

9. The method for producing a high heat resistance polyester fiber material according to claim 8, wherein the birefringence of the undrawn yarn is 0.04 or more.

10. The method for producing a high heat-resistant polyester fiber material according to claim 8, wherein the density of the undrawn yarn is 1.340 gZcm ² or more.