WO2007123059A1

WO2007123059A1 - Heat-resistant crosslinked polyester fiber and heat-resistant crosslinked polyester fiber cord

Info

Publication number: WO2007123059A1
Application number: PCT/JP2007/058138
Authority: WO
Inventors: Shigenori Nagahara; Kenji Yoshino; Yasushi Aikawa
Original assignee: Toyo Boseki Kabushiki Kaisha
Priority date: 2006-04-18
Filing date: 2007-04-13
Publication date: 2007-11-01

Abstract

Disclosed are a polyester fiber and polyester fiber cord having excellent heat resistance which are capable of maintaining mechanical properties at medium and high temperatures and is not thermally melted, while maintaining characteristics such as dimensional stability, high strength and durability. The polyester fiber and polyester fiber cord are useful as a material for belt and carcass members of tires. Specifically disclosed is a heat-resistant crosslinked polyester fiber which is characterized in that the ratio between the storage modulus at 100˚C (E'100) and the storage modulus at 250˚C (E'250), namely E'100/E'250 is not more than 10 in a dynamic viscoelasticity measurement. Also specifically disclosed is a heat-resistant crosslinked polyester fiber cord which is characterized in that the heat-resistant crosslinked polyester fiber is at least partially contained therein and the ratio between the storage modulus at 100˚C (E'100) and the storage modulus at 250˚C (E'250), namely E'100/E'250 is not more than 4 in a dynamic viscoelasticity measurement.

Description

Specification

Heat-resistant cross-linked polyester fiber and heat-resistant cross-linked polyester fiber cord

K

Technical field

[0001] The present invention relates to a heat-resistant crosslinked polyester fiber and a heat-resistant crosslinked polyester fiber cord. Specifically, it has dimensional stability and heat resistance, and more specifically, tire cords, belt materials, canvas, screens that can maintain mechanical properties (storage elastic modulus) in the middle temperature range from room temperature. The present invention provides a heat-resistant cross-linked polyester fiber useful for industrial material applications such as, and a heat-resistant bridge-type polyester fiber cord useful for industrial material applications such as tire cords and belt materials.

Background art

Conventionally, organic fibers such as nylon fibers, rayon fibers, and polyester fibers have been used for tire cords as fiber reinforcing materials for tires. When nylon fibers are used for tire cords, they have high toughness and good adhesion to rubber, but their elongation is relatively large, so that they are inferior in dimensional stability and easily cause a flat spot phenomenon. Also, when rayon fibers are used for tire cords, the strength is lower than that of the nylon fiber tire cords. Therefore, when used for tire carcass members, the amount used must be increased, resulting in tire weight. There is a disadvantage that increases. Furthermore, there are concerns about the future supply of pulp, which is the raw material for rayon fibers. For this reason, attention has been paid to the use of high-strength polyester fibers as tire cords that are excellent in dimensional stability as materials to compensate for the disadvantages of both.

[0003] Further, in recent years, there is a growing need for run-flat tires for improving the safety of automobiles.

A run-flat tire is a tire that can travel at a predetermined speed for a certain distance even if the tire punctures during high-speed driving and the tire internal pressure becomes OKPa. This run-flat tire has a side reinforcement type that is 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 the beat part force of the tire sidewall, and in the tire air chamber. Core tie with an annular core made of metal or synthetic resin attached to the rim Is known.

[0004] This inner side reinforcement type supports the load by the inherent rigidity of the sidewall reinforced with a reinforced rubber layer when the tire punctures and the air escapes during driving, and is capable of traveling over a predetermined distance. In the case of tires with large deflection, frictional heat is generated due to contact with the road surface, and the internal temperature of the tire may be 200 ° C or higher, and extremely high even locally. Thus, the main cause of tire failure is deterioration due to heat generation. Therefore, particularly in the case of runflat tires, heat-resistant rayon fibers, aramide fibers, steel, and the like are used as carcass members.

[0005] Nylon fibers and polyester fibers can be mass-produced by melt spinning, and are advantageous in terms of price and suitable for industrial materials. However, the melting point of nylon 6 is 215-220. C, nylon 66 is 250-260. The melting point of C, positive ethylene terephthalate is 255-260. Although it is C, when the inside of the tire generates heat at 200 ° C or higher, the adhesive interface with the rubber begins to break down, and the strength, dimensional stability and mechanical properties suddenly decrease. Therefore, not only the carcass member for run-flat tires but also belts and other fabric cords are similarly restricted or unsuitable for applications requiring heat resistance.

[0006] As described above, polyester fibers made of copolymerized polyethylene terephthalate are less expensive than rayon fibers. However, if they are provided with functions of heat resistance and mechanical properties, their use is expanded and commercially available. It is advantageous. Furthermore, it can be useful if polyethylene naphthalate fibers or nylon fibers made of copolymerized polyethylene naphthalate are similarly given heat resistance and mechanical properties.

[0007] When the polyester fiber is used for a tire cord, water molecules generated by the neutralization reaction of amine compounds in the rubber with canolepoxy end groups attack the ester bond of the polyester, causing hydrolysis and deterioration. There is a problem to make. Various proposals have been made to solve this problem. For example, a method of providing a polymer having acrylic acid and Z or methacrylic acid (see Patent Document 1), an epoxy compound or a specific diepoxy compound is added to the polyester, and the terminal amount of the carboxy group of the polyester is reduced. (See Patent Documents 2 to 4), a polyester containing a carpositimide compound A method for reducing the amount of terminal carboxyl groups (see Patent Documents 5 to 9) is disclosed. These methods are effective in suppressing the decrease in strength and fatigue resistance by reducing the concentration of carboxy groups, but it is difficult to completely eliminate the terminal amount of carboxyl groups. It does not solve the lack of heat resistance.

[0008] Further, as a method of preventing the deterioration of the carcass member in rubber, a method of protecting by a dipping method after cording is disclosed (see Patent Documents 10 to 12). However, all of these only prevent and protect the fiber surface from entering the amine compound, and the internal structure has not been modified, and the expected effect is small.

[0009] Polyester fiber cords such as copolyester fibers that provide dimensional stability, durability, thermal properties, and the like, and methods for producing the same (see Patent Documents 13 to 17) are disclosed.

[0010] However, all of these tire cords can achieve their objectives by satisfying specific conditions. However, they cannot be improved dramatically and satisfy the heat resistance and mechanical properties as described above. It ’s not something to do.

[0011] On the other hand, a method for improving the heat resistance of a polyester fiber by crosslinking (see Patent Document 18) is disclosed. According to this method, it is described that the melt resistance of tobacco can be improved by immersing the yarn immediately after melt spinning in a crosslinking agent and irradiating it with an electron beam while drawing to form a crosslinked polyester fiber. However, this method has problems in operability and stability, and does not retain the phenomenon of thermal melting or mechanical properties at temperatures above the melting point of polyester.

[0012] A fiber made of a copolymerized polyester fiber having excellent dimensional stability, high strength, durability and the like used for a carcass member belt material is produced by a known method in the art, but is particularly preferable. Examples of the method include methods described in Patent Documents 19 and 20.

Patent Document 1: Japanese Patent Laid-Open No. 55-166235

Patent Document 2: Japanese Patent Laid-Open No. 54-6051

Patent Document 3: Japanese Patent Laid-Open No. 7-166419

Patent Document 4: JP-A-7-166420

Patent Document 5: Japanese Patent Laid-Open No. 58-23916

Patent Document 6: Japanese Patent Application Laid-Open No. 5-163612 Patent Document 7: Japanese Patent Laid-Open No. 10-168661

Patent Document 8: Japanese Patent Laid-Open No. 10-168655

Patent Document 9: Japanese Patent Laid-Open No. 2003-193331

Patent Document 10: JP-A-2-99667

Patent Document 11: JP-A-2-127562

Patent Document 12: JP-A-3-59168

Patent Document 13: Japanese Unexamined Patent Publication No. 2001-115354

Patent Document 14: JP-A-5-71033

Patent Document 15: JP-A-5-59627

Disclosure of the invention

Problems to be solved by the invention

[0014] An object of the present invention is to maintain the excellent dimensional stability, high strength, and durability of a polyester fiber having copolyester strength, and in particular, to maintain heat resistance and mechanical properties at medium temperature and high temperature range. Means for solving the problems of obtaining a heat-resistant crosslinked polyester fiber excellent in shape retention at high temperature, a heat-resistant crosslinked polyester fiber cord, and a rubber composite using the same

[0015] As a result of intensive research, the inventors of the present invention have found that polyester undrawn yarn and Z or drawn yarn obtained by melt-spinning a polymer such as a copolyester cable have at least 2 unsaturated bonds. After impregnating with aliphatic and Z or alicyclic compounds having at least one, it was found that the above object was achieved by irradiating with active light, and the present invention was achieved.

[0016] Specifically, (1) Polyester fibers obtained by melt spinning a polymer having copolyester strength are impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds. Irradiated with actinic rays to form heat-resistant cross-linked fibers, (2) and then twisted into cords, and (3) polyester fibers obtained by melt spinning a polymer that has copolyester strength Polyester fiber cords are impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds and irradiated with actinic rays to withstand resistance. (4) Polyester fiber and Z or polyester fiber cord obtained by melt-spinning a polymer made of copolymerized polyester fiber are treated with a carrier agent in advance, and then (2) or (3 ) By obtaining the code.

[0017] The present invention is as follows.

[0018] 1. Storage modulus E 'at 100 ° C and storage modulus at 250 ° C in dynamic viscoelasticity measurement

100

A heat-resistant cross-linked polyester characterized by a ratio E 'ZE,

250 100 250

Tell fiber.

2. After impregnating the polyester undrawn yarn and Z or drawn yarn obtained by melt spinning the copolyester with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds, 2. The heat-resistant crosslinked polyester fiber as described in 1 above, which is obtained by irradiating actinic rays.

3. An aliphatic and Z or alicyclic group having at least two unsaturated bonds after the polyester undrawn yarn and Z or drawn yarn obtained by melt spinning the copolyester are treated with a carrier agent. 2. The heat-resistant crosslinked polyester fiber according to 1 above, which is obtained by impregnating a compound and then irradiating with actinic rays.

4. The heat-resistant crosslinked polyester fiber according to any one of 1 to 3 above, wherein the actinic ray is an electron beam or a γ-ray.

5. Storage elastic modulus E 'at 100 ° C and storage elastic modulus at 250 ° C in dynamic viscoelasticity measurement

100

There are few heat-resistant cross-linked polyester fibers whose ratio of E, to E 'ZE, is less than 10.

250 100 250

Storage elastic modulus E 'and 25 at 100 ° C in dynamic viscoelasticity measurement.

100

Storage elastic modulus E at 0 ° C, ratio E '/ E

250 100 250

Crosslinkable polyester fiber cord.

6. The polyester fiber obtained by melt spinning the copolyester is impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds and irradiated with active light, and then the fiber cord and 6. The heat-resistant crosslinked polyester fiber cord as described in 5 above.

7. Polyester fiber cords such as polyester fibers obtained by melt spinning a copolyester are aliphatic and Z or fat having at least two unsaturated bonds. 6. The heat-resistant crosslinked polyester fiber cord according to 5 above, wherein the cyclic compound is impregnated and irradiated with actinic rays.

8. Polyester fibers and Z or polyester fiber cords are pretreated with a carrier agent, and then impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds and irradiated with actinic rays. 8. The heat-resistant crosslinked polyester fiber cord according to 6 or 7 above.

9. The heat-resistant crosslinked polyester fiber cord according to any one of 5 to 8 above, wherein the actinic ray is an electron beam or a γ-ray.

10. A pneumatic radial tire using the heat-resistant crosslinked polyester fiber cord described in any one of 5 to 9 as a carcass material.

11. A rubber composite using a heat-resistant crosslinked polyester fiber cord described in 5 to 5 above: LO.

The invention's effect

[0019] The present invention relates to storage elastic modulus E 'at 100 ° C and storage at 250 ° C in dynamic viscoelasticity measurement.

100

The ratio of elastic modulus E, ratio E 'ZE, is 10 or less.

250 100 250

The present invention provides a re-ester fiber, and includes at least a part of the above-mentioned heat-resistant cross-linked polyester fiber, and has a storage elastic modulus E ′ at 250 ° C. and 250 in dynamic viscoelasticity measurement.

100

Storage elastic modulus E at ° C, ratio E '/ E, value power of

250 100 250

Cross-linking type

A polyester fiber cord is provided. Polyester fibers that also have copolyester strength are impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds, and then irradiated onto the surface layer of the polyester fibers by irradiation with electron beams, γ rays, etc. The cross-linking reaction between compounds with unsaturated bonds existing and the cross-linking reaction between compounds with unsaturated bonds penetrating inside or inside suppresses the fluidity of the amorphous and crystalline parts due to heating in the middle and high temperature range. As described above, the mechanical properties can be maintained and the shape can be maintained even at a temperature higher than the melting point temperature.

[0020] In general, polyester fibers gradually decrease in mechanical properties (storage elastic modulus Ε ') due to heating at a temperature of about 100 ° C. This is because the non-crystalline part has a large thermal motion due to heating. As the temperature rises further, the partial crystal force easily breaks down and the mechanical properties further decline, and as a result, fluidity is exhibited and this temperature is defined as the melting temperature. When the temperature reaches the melting point or higher, the shape cannot be maintained due to thermal fluidity. However, what is surprising in the present invention is that the storage elastic modulus E ′ does not significantly decrease in the melting point temperature range of 255 to 260 ° C. of the polyester fiber and does not melt at higher temperatures. As a result, the shape can be held.

Therefore, the present invention is useful as a run-flat tire cord member that particularly requires heat resistance, mechanical properties, and the like, and also provides heat resistance to functional fibers other than copolymerized polyester fibers by the method of the present invention. Application development is also possible.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The present invention is a heat-resistant cross-linking type that retains mechanical properties (storage elastic modulus) in the middle and high temperature range from room temperature to heat and can retain its shape without being melted by heat at a temperature equal to or higher than the melting point of the copolymer polyester. Polyester fiber, that is, the ratio of the storage elastic modulus E 'at 100 ° C and the storage elastic modulus E at 250 ° C in dynamic viscoelasticity measurement, E' / E, is less than 10

100 250 100 250

A thermally crosslinkable polyester fiber is provided. The ratio of the storage modulus E ′ at 100 ° C. to the storage modulus E at 250 ° C. in the dynamic viscoelasticity measurement is at least partially including the above heat-resistant crosslinked polyester fiber. E '/ E, the value of

100 250 100 250

A heat-resistant cross-linked polyester fiber cord is provided.

[0022] The copolyester, particularly the aromatic copolyester in the present invention is a polycondensate of an aromatic dicarboxylic acid component and a diol component, and is not particularly limited, including known ones. Further, an unsaturated group-containing polyester obtained by reacting with a glycidyl group-containing unsaturated compound using a polyester acid terminal may be used. Aromatic dicarboxylic acid components include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid Examples include 5-sodium sulfophthalic acid. Of these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferred. Diol components include ethylene glycol, diethylene glycol, triethylene glycol Aliphatic diols such as cornole, trimethylene glycol, tetramethylene glycol, propylene glycol, otaethylene glycol, decanmethylene glycol, polyethylene glycol; alicyclic diols such as cyclohexanediol and cyclohexanedimethanol; Examples include aromatic diols such as naphthalenediol, bisphenol A, and resorcin. Of these, aliphatic diols such as ethylene glycol and trimethylene glycol are preferred. In the aromatic polyester of the present invention, the aromatic dicarboxylic acid component and the diol component are each composed of a single monomer, and may be a copolyester composed of three or more kinds. Further, it may be a blend of two or more types of aromatic polyester resin.

[0023] Further, a small amount of any other polymer, antioxidant, radical supplement, electrostatic agent, dyeing improver, dye, pigment, matting agent, fluorescent brightener, Active fine particles and other additives may be contained. The aromatic polyester can be obtained by polycondensing a reaction product of an aromatic dicarboxylic acid component and Z or an ester-forming derivative thereof with a diol component, which does not require special polymerization conditions, into a polyester. Can be synthesized by any method employed. The polymerization equipment can be batch or continuous. Furthermore, after the polyester obtained in the liquid phase polycondensation step is granulated and pre-crystallized, it can be subjected to solid phase polymerization in an inert gas atmosphere or under reduced pressure under a temperature below the melting point.

[0024] 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. When these catalysts are used alone or in combination of two or more, the amount used is 0.002 to 0.1 mol% based on the aromatic carboxylic acid component constituting the polyester. preferable.

[0025] In addition, the intrinsic viscosity (IV) of the copolyester in the present invention is preferably 0.6 or more, more preferably 0.8 or more. If IV is 0.6 or less, the intended strength and inertia cannot be obtained.

Further, the amount of carboxy terminal group of the aromatic polyester is preferably 50 eqZton or less, more preferably 30 eqZton or less. If it exceeds 50eqZton, polyester When used as a cord, durability is deteriorated due to the occurrence of hydrolysis by an amine compound entering from rubber, which is not preferable.

[0026] In the present invention, it is possible to employ a method in which the copolymerized polyester is used as a yarn under the usual melt spinning conditions. Then, it can be obtained by, for example, thermal stretching by a spin draw method of stretching. In general, the thermal stretching is performed by one-stage stretching at a high magnification or multi-stage stretching of two or more stages. The heating method includes a method using a superheated roll, superheated steam, a heat plate, a heat box or the like, and is not particularly limited.

As these polyester fibers, those excellent in dimensional stability, high strength and durability manufactured for industrial materials such as a reinforcing material for rubber products such as tires can be preferably used.

[0027] In the present invention, the undrawn yarn and Z or drawn yarn of the copolyester fiber thus obtained are impregnated with an aliphatic and Z or alicyclic compound having at least two unsaturated bonds, Polyester fibers with unsaturated compounds present on the surface and Z or inside of the polyester fibers are produced batchwise or continuously.

In the present invention, a heat-resistant crosslinked fiber cord can be obtained by the following method.

That is, (1) aliphatic and Z or alicyclic compounds having at least two unsaturated bonds using a drawn fiber of copolymer polyester fiber obtained by melt spinning a polymer having copolyester strength Is made into polyester fiber with aliphatic and Z or cycloaliphatic compounds present in the polyester fiber, then irradiated with actinic rays to form crosslinked polyester fiber, and then used as a cord with a ring twisting machine or straight twisting machine. (2) Fat having at least two unsaturated bonds in a ring twisting machine using a copolymerized polyester fiber obtained by melt spinning a polymer having copolyester strength as a cord with a direct twisting machine After impregnating with aliphatic and Z or alicyclic compounds, the polyester fiber is made to contain aliphatic and Z or alicyclic compounds, and then irradiated with actinic rays to form a crosslinked type. There are ways to Riesute Le fiber cord, producing batchwise or continuously.

[0029] In the present invention, a heat-resistant crosslinked fiber and a heat-resistant crosslinked fiber cord can be obtained by the following method. That is, (1) at least two unsaturated bonds using a drawn yarn of a copolyester fiber obtained by melt spinning a polymer having copolyester strength After impregnating with the aliphatic and Z or alicyclic compound possessed to make the polyester fiber a polyester fiber with the aliphatic and Z or alicyclic compound present, actinic rays are irradiated to form a crosslinked polyester fiber. (2) , A method in which this crosslinked polyester fiber is corded by a ring twisting machine or a straight twisting machine, and (3) a ring twisting machine using a copolymerized polyester fiber obtained by melt spinning a polymer comprising a copolymerized polyester fiber. It is implied that aliphatic and Z or alicyclic compounds having at least two unsaturated bonds impregnated in the cords of a straight twist machine and that the polyester fiber contains aliphatic and Z or alicyclic compounds. A method of irradiating actinic rays to form a crosslinked polyester fiber cord, and (4) a copolymer obtained by melt spinning a polymer such as a copolymerized polyester fiber. Polyester fibers and / or polyester fiber cords are pretreated with a carrier agent, impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds, and then irradiated with actinic rays to crosslink polyester. There are methods to make fibers and cross-linked polyester fiber cords, which are manufactured batchwise or continuously.

[0030] In the present invention, a raw cord can be formed by a ring twisting machine or a straight twisting machine by a conventional method. The standard raw cord is 10 ~ per 10cm: After applying the LOO twist (lower twist), combine multiple yarns, and the opposite side is 10 ~ per 10cm: the twist (upper twist) And

[0031] The aliphatic and Z or alicyclic compounds having at least two unsaturated bonds used in the present invention are compounds capable of proceeding radical polymerization reaction by irradiation with ultraviolet rays, electron beams, γ rays, etc. Unsaturated group in one molecule consisting of attalyloyl group, methacryloyl group, itaconol group, maleolyl group, fumaroyl group, crotoyl group, attalyloylamino group, methacryloylamino group, cinnamoyl group, vinyl group, aryl group, styryl group, etc. A compound having two or more and derivatives thereof. Specific examples include (ethylene, diethylene, triethylene) glycol dimetatalate, polyethylene glycol dimetatalate, 1, 3 butylene glycol dimetatalate, 1, 4 butanediol dimetatalate, 1, 6 Xanthandiol dimetatalylate, 1,9-nonanediol dimetatalylate, neopentyl dallicol dimetatalylate, trimethylolpropane tri (meth) acrylate, trimethylol methane (meth) acrylate, tetramethylol methane tetra acrylate, Pentaerythritol tetraatalylate, dipentaerythritol pentaatalylate, bisphenol in one molecule Examples thereof include, but are not limited to, epoxyacrylates obtained by (meth) atalylating an aliphatic or alicyclic group having a Nord A skeleton.

[0032] The concept for maintaining the storage elastic modulus E 'in the high temperature range from the normal temperature according to the present invention is how to reduce the thermal motion due to the heating temperature of the crystalline part and the amorphous part. In the method according to the present invention, the surface layer formed on the polyester fiber and fiber cord acts as a thermal noria layer by the cross-linking reaction, and a small amount of unsaturated compound inside the polyester fiber and cord is impregnated. As a result of the cross-linking reaction between the unsaturated compounds and the cross-linking reaction between the unsaturated compound in the surface layer and the internal unsaturated compound, the polyester structure (non-crystalline part and crystalline part) It is presumed that the thermal motility due to heating is suppressed to a small extent, and that is why the storage elastic modulus E ′ is maintained without significantly decreasing. Particularly, the crosslinking reactivity of unsaturated compounds becomes important, and in the present invention, unsaturated compounds having an unsaturated group functional group number of more than ^, particularly preferably an unsaturated functional group number of 3 or more are preferred. Especially

-(R) group-containing (meth) atalylate compounds can be preferably used. As a means for advancing the radical reaction of these unsaturated compounds, the ultraviolet rays, electron beams, γ rays, etc. can be used, and in order to advance the crosslinking reaction of the impregnated unsaturated compounds, electrons having excellent permeability are used. Lines and gamma rays can be preferably used. However, depending on the intended use, ultraviolet rays for cross-linking the surface layer can be used and are not limited. In order to advance the crosslinking reaction with ultraviolet rays, it is preferable to add a radical polymerization initiator. In particular, the type and amount of the radical polymerization initiator are not limited.

[0033] A preferable viscosity of the unsaturated compound used in the present invention can be used in the range of 5 to LOOOcps at room temperature (25 ° C), but it may be heated to such an extent that the compound does not volatilize. Yes. Furthermore, it is preferable to warm up to the vicinity of the glass transition point of the aromatic copolyester so that the compound is actively impregnated into the polyester fiber.

[0034] The conditions for impregnating the polyester fiber and fiber cord with the unsaturated compound are not particularly limited, but it is preferable to immerse in a warm bath at 30 to L00 ° C for about 3 to 15 minutes. Polyester fiber and fiber cord attached to the fiber cord can be It is preferable that the thickness after removal of the polyester fiber and the fiber cord surface layer after cross-linking is: m or more, preferably 4 m or more. When the thickness of the surface layer is 1 m or less, it is disadvantageous because the crosslinking density is insufficient and the heat resistance is insufficient.

In the present invention, it is preferable to use a carrier agent in order to improve the permeability when the copolymerized polyester fiber and the copolymerized polyester fiber cord are impregnated with an unsaturated compound. In particular, the use of a carrier agent is preferably recommended in order to improve the permeability when an unsaturated compound is impregnated into a polyester fiber that has already been twisted and corded. The overlap caused by twisting of polyester fibers tends to be insufficient for unsaturated compound permeability, and as a result, the heat resistance due to insufficient crosslinking due to insufficient permeability for unsaturated compounds is prevented. It is to do. There are methods such as increasing the impregnation time or positively heating, but this is not industrially preferable.

[0036] Specific examples of the carrier agent include 1,2,4-trichlorodiethylbenzene, orthodichlorobenzene, orthophenylphenol, diethyl ether, methylnaphthalene, butyl benzoate, dimethyl terephthalate, and methyl salicylate. Carriers are exemplified, and in the case of spray treatments where immersion treatment and spraying treatment are preferred, the carrier treatment is preferably heated and treated before 100 ° C.

[0037] In order to obtain the heat-resistant crosslinked polyester fiber and the heat-resistant crosslinked polyester fiber cord of the present invention, the impregnated compound is impregnated with actinic rays such as ultraviolet rays, electron beams, and γ rays. An electron beam or _γ- ray that is irradiated and generates a radical reaction to be crosslinked and has a particularly high transmittance of irradiation energy among actinic rays can be preferably used. In the present invention, the irradiation energy of the active rays, 50~: LOOOOKGy, is preferably irradiated with an electron beam at 1000～6000KG _y crosslinking. When the irradiation energy of the electron beam is 50KGy or less, the crosslinking reaction does not proceed sufficiently, so heat resistance cannot be obtained and the storage elastic modulus E 'cannot be maintained, and the formed crosslinking reaction layer becomes brittle when irradiated with lOOOOKGy or more. Furthermore, the polyester is further decomposed and the strength properties are deteriorated, which may make it difficult to maintain the storage elastic modulus E '. /.

[0038] The dynamic viscoelasticity measurement of the heat-resistant crosslinked polyester fiber of the present invention at 100 ° C Storage elastic modulus E '100 and storage elastic modulus at 250 ° C E' 250 Ratio E, / E 'is within 10

100 250

Is preferred. When this ratio is 10 or more, the heat resistance of the polyester fiber is insufficient, and the mechanical properties are lowered and the shape is difficult to maintain. More preferably, the values of storage elastic modulus E and ZE 'are 5

It is preferably within 100 250, more preferably within 2.

[0039] Ratio E, / E 'of storage elastic modulus E' at 100 ° C and storage elastic modulus E 'at 250 ° C in dynamic viscoelasticity measurement of heat-resistant crosslinked polyester fiber cord of the present invention Value within 4

100 250 100 250

Is preferred. When this ratio is 5 or more, the heat resistance of the polyester fiber cord is insufficient, and the mechanical properties are deteriorated and the shape is difficult to maintain. More preferably, the ratio of storage elastic modulus E 'E' /

100

The value of E ′ is preferably within 2.

250

Example

[0040] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Various measuring instruments and measuring methods are shown below.

[0041] (1) Electron beam irradiation

measuring equipment

Irradiator Elect mouth curtain lab machine

Acceleration voltage 165KV

Electron current 5mA

Measuring method

A sample obtained by the immersion treatment was set on a tray and irradiated with an electron beam. The electron beam was irradiated evenly on the front and back, and the irradiation amount was the sum of them.

[0042] (2) Dynamic viscoelasticity

measuring equipment

Equipment Rheogel-E4000 Made by UBM

Measurement conditions Frequency 11Hz

Starting temperature 30 ° C

Step temperature 2 ° C

End temperature 300 ° C

Temperature increase rate 5 ° C / min Sample width 5mm, length 15mm

Measuring method

After setting the sample in a measuring instrument, the measurement was performed under the measurement conditions. After the measurement was completed, the shape was maintained!

[0043] (3) Intrinsic viscosity

The polymer was dissolved in parachlorophenol Z tetrachloroethane = 3 Zl mixed solvent at a concentration of 0.4 gZdl and measured at 30 ° C.

[0044] (4) Fineness

According to the definition of JIS-L1017, the fineness was measured after leaving in a room where temperature and humidity were controlled at 20 ° C and 65% RH for 24 hours.

[0045] (5) Strength

According to the definition of JIS-L1017, it was measured in a tensile tester after being left for 24 hours in a room controlled at 20 ° C and 65% RH.

[0046] (6) Surface layer thickness

It measured using the thickness measuring machine.

The thickness of the surface layer was determined by subtracting the thickness of the polyester fiber before impregnation from the thickness power of the impregnated and crosslinked polyester fiber.

[0047] (7) Heat flow start temperature

After placing the sample on a hot plate that can be set to a certain temperature for 1 minute, it is judged whether it melts and flows by heat or visually or under a microscope. ).

[0048] (Example 1)

Adjust the discharge rate of polyethylene terephthalate chips with an intrinsic viscosity (IV) of 0.95 at a spinning temperature of 310 ° C and a spinneret of 336 holes so that the fineness becomes 1440dtex, and 70 ° C in the spinning cylinder. 1. After pulling the yarn cooled and solidified with OmZsec cooling air at a spinning speed of 3400 mZmin, a polyester fiber stretched at a draw ratio of 1.6 to obtain a strength of 6.9 cNZdtex was obtained. . Using this polyester fiber, after being immersed for 5 minutes in a bath made of pentaerythritol tetratalate (viscosity 342cps, 25 ° C) at room temperature, The required impregnated polyester fibers were squeezed with a roller and placed in a required amount tray, and irradiated with an electron beam with a total electron energy of 6000 kgy. Using the obtained electron beam cross-linked polyester fiber, measurement was performed by each measurement method.

[0049] (Example 2)

It was processed and measured in the same manner as in Example 1 except that the bath temperature of pentaerythritol tetraatalylate was heated to 70 ° C and processed.

[Example 3]

The polyester fiber used in Example 1 was preliminarily treated with a 100 ° C. warm-mouthed benzene carrier for 5 minutes, and then treated and measured in the same manner as in Example 2.

[0051] (Example 4)

Electron beam cross-linking obtained by obtaining an impregnated polyester fiber in the same manner as in Example 1 except that pentaerythritol tetraatalylate was switched to trimethylolpropane tritalylate, and irradiating with an electron beam in the same manner as in Example 1. 7 pieces measured with each measuring method using the polyester fiber.

[Example 5]

In the same manner as in Example 3, after immersion treatment with a carrier agent, the bath temperature comprising trimethylolpropane tritalate was heated to 70 ° C. and treated in the same manner as in Example 3 and measured.

[0053] (Comparative Example 1)

The polyester fiber used in Example 1 was measured for the state of fiber without compound impregnation treatment or electron beam crosslinking.

[Comparative Example 2]

Polyethylene terephthalate chips with an intrinsic viscosity (IV) of 1.05 were fed to the melt extruder and at the same time diaryl monoglycidyl isocyanurate heated to 50-60 ° C from the etastruder inlet to polyethylene terephthalate. It was added at a constant flow rate so as to be 0.7 weight ^_0/0. Adjust the discharge rate of this kneaded polymer at a spinning temperature of 310 ° C from a spinneret with 336 pores so that the fineness becomes 1440dtex, and cool and solidify in the spinning cylinder at 70 ° C, 1. OmZsec cooling air After pulling the caulked yarn at a spinning speed of 3400mZmin, the strength continues. 6. A polyester fiber stretched at a stretch ratio of 1.6 to obtain 5 cNZdtex was obtained. The necessary amount of the polyester fiber was placed in a tray and irradiated with an electron beam with a total electron energy of lOOOKGy. The obtained electron beam cross-linked polyester fiber was used and measured by each measuring method.

[table 1]

* 1: In Comparative Example 2, a building agent is added to a polymer that is not indulgent. Carrier A: Black mouth benzene

PETA: Pentaerisuri!

TMPA: Tri-Met mouthpiece, Rubropan Triacre

DA-MGIC: diallyl monoglycidyl isocyanurate

[Example 6]

Two pieces of the electron beam cross-linked polyester fiber obtained in Example 1 were twisted to obtain a raw cord of 1440 dtex Z2 and a twist number of 43 × 43 (tZl0 cm), and measurement was performed by each measurement method.

[0057] (Example 7)

Using the electron beam cross-linked polyester fiber obtained in Example 2, the raw cord was measured in the same manner as in Example 6.

[Example 8]

Using the electron beam cross-linked polyester fiber obtained in Example 4, the raw cord was measured in the same manner as in Example 6.

[Example 9]

Only the necessary measurement was performed on the polyester fiber which had been treated and crosslinked in the same manner as in Example 1 except that trimethylolpropane tritalylate was used and the immersion condition was a 70 ° C. bath. Next, measurement was performed using raw cords in the same manner as in Example 6.

[Example 10]

Twist the polyester fibers used in Example 1 and immerse the raw cord made of 1440dtexZ2 and twist number 43 X 43 (tZlOcm) in advance with a black mouth benzene carrier heated at 100 ° C for 5 minutes, and then Then, the sample was immersed in a trimethylolpropane tritalylate at 70 ° C for 5 minutes and irradiated with an electron beam with an electron energy of 6000KGy. The obtained electron beam cross-linked polyester fiber cord was measured by each measuring method.

[0061] (Comparative Example 3)

Using the polyester fiber of Comparative Example 1, measurement was performed using the same method as in Example 6 to obtain a raw cord.

[0062] (Comparative Example 4)

Using the electron beam cross-linked polyester fiber obtained in Comparative Example 2, a raw cord was measured in the same manner as in Example 6.

As apparent from Table 1 and FIGS. 1 and 2, the polyester fibers obtained in Examples 1 to 5 retain the stored viscoelastic modulus E ′. Furthermore, even when the heat flow start temperature was 340 ° C, the polyester fiber was excellent in heat resistance with no heat flow and shape. [0064] On the other hand, as shown in Table 1 and FIG. 3, the uncrosslinked polyester fiber obtained in Comparative Example 1 gradually decreased in storage elastic modulus E ′ from 100 ° C. or higher, and had a melting point and Mechanical properties are not maintained at temperatures above the melting point. In addition, the heat flow start temperature flowed around 255 ° C near the melting point, and it did not maintain its shape. In addition, as shown in Table 1 and FIG. 4, the polyester fiber obtained in Comparative Example 2 has a storage elastic modulus E ′ that gradually decreases from 100 ° C or higher, and has a mechanical strength at the melting point and above the melting point. Physical properties are not maintained. In addition, the heat flow start temperature was around 264 ° C near the melting point, and it did not maintain its shape.

As is clear from Table 2 and FIGS. 5 to 6, the polyester fiber cords obtained in Examples 6 to 10 retain the storage viscoelastic modulus E ′. Further, even when the heat flow starting temperature was 340 ° C, the polyester fiber cord had excellent heat resistance and no heat flow and the shape was maintained.

[0066] On the other hand, as shown in Table 2 and FIG. 7, the polyester fiber cord obtained in Comparative Example 3 has a storage elastic modulus that gradually decreases from 130 ° C or higher. The physical properties are not maintained. In addition, the heat flow start temperature was around 255 ° C near the melting point, and it did not maintain its shape.

In addition, as shown in Table 2 and FIG. 8, the polyester fiber cord obtained in Comparative Example 4 gradually decreased in storage modulus from 130 ° C or higher, and the mechanical properties were maintained at the melting point and above the melting point. Not. Also, the heat flow starting temperature flowed around 267 ° C near the melting point and did not retain its shape.

[0067] [Table 2]

* 2: Comparative Example 4 does not contain *. Carrier A: Black mouth benzene

PETA Bentaerythritol tetraacrylate

TMPA: Tri-Met mouthpiece, Rubropan Triacre

DA—MGIC: diallyl monoglycidyl isocyanurate

[0068] Storage elastic modulus E 'at 100 ° C and storage at 250 ° C in the dynamic viscoelasticity measurement of the present invention

100

Heat resistant cross-linked polyester fiber with a modulus E, ratio E '/ E, of 10 or less

250 100 250

Can maintain the mechanical properties and maintain the shape even at temperatures higher than the melting point temperature, and the storage elastic modulus E ′ at 100 ° C and 250 ° C in the dynamic viscoelasticity measurement of the present invention. of

100

Storage elastic modulus E, ratio E '/ E, value power

250 100 250

The type polyester fiber cord can retain its mechanical properties and retain its shape even at a temperature higher than the melting point temperature. The method of impregnating aliphatic and Z or alicyclic compounds having at least two unsaturated bonds and irradiating them with actinic rays, thereby improving the heat resistance and mechanical properties, as well as the fibers of copolyester strength. It can be used for other natural fibers, organic fibers, and fiber cords using the same. It is also expected to be used in other fields such as film and engineering plastics where heat resistance and dimensional stability are required.

Brief Description of Drawings

[0069] [FIG. 1] Storage elastic modulus E ′ of the heat-resistant crosslinked polyester fiber obtained in Example 1.

FIG. 2 is a storage elastic modulus E ′ of the heat-resistant crosslinked polyester fiber obtained in Example 4.

FIG. 3 is a storage elastic modulus E ′ of the polyester fiber of Comparative Example 1.

FIG. 4 is a storage elastic modulus E ′ of the crosslinked polyester fiber of Comparative Example 2.

FIG. 5 is a storage elastic modulus E ′ of the heat-resistant crosslinked polyester fiber cord obtained in Example 1.

FIG. 6 is a storage elastic modulus E ′ of the heat-resistant crosslinked polyester fiber cord obtained in Example 3.

FIG. 7 is a storage elastic modulus E ′ of the polyester fiber cord of Comparative Example 1.

FIG. 8 is a storage elastic modulus E ′ of the polyester fiber cord of Comparative Example 2.

Claims

The scope of the claims

[1] Storage elastic modulus E 'at 100 ° C and storage elastic modulus E' at 250 ° C in dynamic viscoelasticity measurement

100

Heat-resistant cross-linked polyester, characterized in that the ratio of E 'ZE, is 10 or less

250 100 250

fiber.

[2] After the polyester undrawn yarn and Z or drawn yarn obtained by melt spinning the copolyester are impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds 2. The heat resistant cross-linked polyester fiber according to claim 1, obtained by irradiating with actinic rays.

[3] After the polyester undrawn yarn and Z or drawn yarn obtained by melt spinning the copolyester are treated with a carrier agent, an aliphatic and Z or alicyclic compound having at least two unsaturated bonds 2. The heat-resistant crosslinked polyester fiber according to claim 1, obtained by irradiating with actinic rays after impregnation.

[4] The heat-resistant crosslinked polyester fiber according to any one of claims 1 to 3, wherein the actinic ray is an electron beam or a γ-ray.

[5] Storage elastic modulus E 'at 100 ° C and storage elastic modulus E' at 250 ° C in dynamic viscoelasticity measurement

100

At least a heat-resistant cross-linked polyester fiber having a ratio E'ZE of 10 or less

250 100 250

Included in part, storage elastic modulus E 'at 100 ° C and 250 ° C in dynamic viscoelasticity measurement

Heat resistance characterized by a storage elastic modulus E at 100, the ratio E '/ E

250 100 250

Cross-linked polyester fiber cord.

[6] Polyester fibers obtained by melt spinning the copolyester are impregnated with aliphatic and Z or alicyclic compounds having at least two unsaturated bonds and irradiated with actinic rays, and then fibers 6. The heat-resistant crosslinked polyester fiber cord according to claim 5, wherein the cord is a cord.

[7] A polyester fiber cord obtained by melt spinning a copolyester is impregnated with an aliphatic and Z or alicyclic compound having at least two unsaturated bonds and irradiated with actinic rays. 6. The heat resistant cross-linked polyester fiber cord according to claim 5, wherein the cord is irradiated.

[8] Polyester fibers and Z or polyester fiber cords are pre-treated with a carrier agent After that, the heat-resistant crosslinked polyester fiber cord according to claim 6 or 7, which is impregnated with an aliphatic group having at least two unsaturated bonds and Z or an alicyclic compound and irradiated with actinic rays. .

[9] The heat-resistant crosslinked polyester fiber cord according to any one of [5] to [8], wherein the actinic ray is an electron beam or a gamma ray.

[10] A pneumatic radial tire using the heat-resistant crosslinked polyester fiber cord according to any one of claims 5 to 9 as a carcass material.

[11] A rubber composite using the heat-resistant crosslinked polyester fiber cord according to any one of claims 5 to 10.