JP2008308644A - Flame-retardant copolyester composition and flame-retardant polyester fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant copolyester composition which has improved drip resistance and a good self fire-extinguishing property, when contacting with flames, has good physical properties and heat resistance, and can give flame-retardant polyester fibers and the like, and to provide flame-retardant polyester fibers. <P>SOLUTION: The present invention relates to the flame-retardant copolyester composition, characterized by copolymerizing a specific phosphaphenanthrene-based phosphorus compound in a phosphorus atom content of 0.3 to 1.5 wt.% in the copolyester composition, copolymerizing an organic sulfonate in an amount of 0.05 to 0.5 mol% on the basis of all acid components (excluding the organic sulfonate) constituting the copolyester, and containing a laminar compound in an amount of 0.1 to 5 wt.% based on the copolyester composition, and to fibers using the flame-retardant copolyester composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flame retardant polyester copolymer composition and a flame retardant polyester fiber. More specifically, the present invention relates to a flame retardant polyester copolymer composition and a flame retardant polyester fiber excellent in melt dripping resistance (drip resistance) and self-extinguishing properties.

  In recent years, various organic polymer materials are required to be provided with flame retardancy, and various techniques have been developed. Polyester is widely used as a fiber, film, and resin because it has many excellent properties, but its flammability is classified as “flammable” and burns in air. For this reason, various methods for increasing the flame retardancy of polyester have been developed. For example, polyester fibers mainly composed of polyethylene terephthalate will be described. As methods for enhancing the flame retardancy, there are known three methods: (1) post-processing method, (2) blending method, and (3) copolymerization method.

  (1) The post-processing method is a method of treating with yarn or woven or knitted fabric. A method of exhausting or adhering a halogen-based flame retardant to a fiber by a bathing method or a padding method (see Patent Document 1), global environmental conservation As a flame retardant processing technique with less environmental burden, a method of exhausting or adhering a phosphorus flame retardant to a fiber by a bathing method or a padding method has been proposed (see Patent Document 2). The blending method (2) is a method in which a flame retardant is kneaded into a polymer at the polyester production stage or spinning stage, but there are various technical difficulties and few examples have been put to practical use. As a copolymerization method of (3), a method in which a copolymerizable monomer (flame retardant) containing phosphorus is added to the reaction system in the polyester production stage and copolymerized randomly with the polyester has been put into practical use. As such monomers, carboxyphosphinic acid compounds (see Patent Document 3) and phosphaphenanthrene compounds (see Patent Document 4) have been proposed.

  On the other hand, as a cationic dye-dyeable flame-retardant polyester fiber, a polyester fiber obtained by copolymerization of the phosphaphenanthrene compound and isophthalic acid having a metal sulfonate group has been proposed (Patent Documents 5 to 8). reference).

  However, all of the above methods are difficult to drip-promoting due to the effects of self-extinguishing that are characteristic of phosphorus compounds and the effect of melting dripping that is based on the decrease in melt viscosity caused by phosphorus compounds and the fibers are melted and dropped from the fire source. It is a method of imparting flammability, and there are problems that it is difficult to apply to blended fiber products that inhibit melting, there is a risk of burns if it adheres to the skin, and there is also a risk of secondary fire spread by drip .

  Furthermore, in the above-mentioned cationic dye-dyeable flame-retardant polyester fiber, due to the use of a considerable amount of isophthalic acid having a sulfonic acid metal base, the process passability during melt spinning is deteriorated and obtained. There is a problem that the fiber physical properties such as strength of the fibers to be obtained and heat resistance are inferior.

Further, it contains a polyester composition containing a layered compound treated with a polyether and / or silane compound and a thermoplastic polyester resin, or a thermoplastic polyester resin obtained by copolymerizing the layered compound and a phosphorus flame retardant. A flame retardant polyester fiber with improved drip resistance formed from a polyester composition has been proposed (see Patent Document 9). However, this proposal also has insufficient drip resistance during combustion and flame retardant improvement effects.
From such a background, a flame retardant polyester fiber having improved drip resistance at the time of flame contact and having self-extinguishing properties and good physical properties has been desired.

JP 62-57985 A JP 2001-11775 A Japanese Patent Publication No.53-13479 Japanese Patent Publication No. 55-41610 JP 56-106921 A JP 2004-107516 A JP 2005-162817 A JP 2005-320533 A WO2002 / 086209 pamphlet

  The present invention has been made in view of the above-mentioned background, and its purpose is to improve the drip resistance at the time of flame contact and also has a self-extinguishing property, and has a good physical property and heat resistance, etc. Is to provide a flame retardant polyester copolymer composition and a flame retardant polyester fiber.

  In order to achieve the above object, the present inventor has made various studies focusing on polyesters copolymerized with the above-described phosphaphenanthrene compounds, and as a result, has copolymerized a specific amount of the phosphaphenanthrene compounds. A polyester copolymer composition comprising a cationic dye and a specific amount of a layered compound with respect to a non-dyeable polyester copolymer, which is copolymerized with a small amount of isophthalic acid having a sulfonate group, In addition, the drip resistance and flame retardancy are remarkably improved synergistically, and a flame retardant polyester copolymer composition having good physical properties and heat resistance is obtained, and the object of the present invention can be achieved. I found it. The present invention has been completed as a result of repeated studies based on these findings.

  That is, the present invention relates to the following flame retardant polyester copolymer composition and fibers comprising the flame retardant polyester copolymer composition.

（式中、Ｒ_１は１価のエステル形成性官能基であり、Ｒ_２、Ｒ_３は同一又は異なる基であって、それぞれ１価の炭素原子数１〜１０の炭化水素基およびＲ_１より選ばれ、Ａは２価もしくは３価の有機残基を示す。ｎ１は１または２であり、ｎ２、ｎ３はそれぞれ０〜４の整数を表わす。）で表わされる有機リン化合物がポリエステル共重合体組成物中のリン原子の含有量として０．３〜１．５重量％および下記一般式（２）

（式中、Ｚは３価の芳香族炭化水素基または脂肪族炭化水素基、Ｘ_１はエステル形成性官能基、Ｘ_２はＸ_１と同一もしくは異なるエステル形成性官能基あるいは水素原子、Ｍはアルカリ金属、アルカリ土類金属または第４級ホスホニウム、ｍは１または２を示す。）で表わされる有機スルホン酸塩がポリエステル共重合体を構成する全酸成分(前記有機スルホン酸塩を除く)に対して０．０５〜０．５モル％となる量共重合されており、かつ層状化合物がポリエステル共重合体組成物に対して０．１〜５重量％となる量含有されている難燃性ポリエステル共重合体組成物。
２．上記１に記載の層状化合物の平均粒径が５〜１００ｎｍの範囲にある上記１記載の難燃性ポリエステル共重合体組成物。
３．上記１に記載の層状化合物が層状ケイ酸塩である上記１記載の難燃性ポリエステル共重合体組成物。
４．窒素雰囲気下において室温から１０℃／分の昇温速度で加熱したときの６００℃到達時点における加熱残分量が１５重量％以上、かつ空気雰囲気下において室温から１０℃／分の昇温速度で加熱したときの減量開始温度が４０５℃以上である、上記１〜３のいずれかに記載の難燃性ポリエステル共重合体組成物。
５．上記１〜４記載のいずれかに記載の難燃性ポリエステル共重合体組成物を溶融紡糸してなる、ＬＯＩ値が２７以上である難燃性ポリエステル繊維。 1. The following general formula (1)

(In the formula, R ₁ is a monovalent ester-forming functional group, R ₂ and R ₃ are the same or different groups, and each is a monovalent hydrocarbon group having 1 to 10 carbon atoms and R ₁ . A represents a divalent or trivalent organic residue, n1 is 1 or 2, and n2 and n3 each represents an integer of 0 to 4). The phosphorus atom content in the composition is 0.3 to 1.5% by weight and the following general formula (2)

Wherein Z is a trivalent aromatic hydrocarbon group or aliphatic hydrocarbon group, X ₁ is an ester-forming functional group, X ₂ is the same or different ester-forming functional group or hydrogen atom as X _1, and M is The organic sulfonate represented by alkali metal, alkaline earth metal or quaternary phosphonium, m represents 1 or 2) is a total acid component (excluding the organic sulfonate) constituting the polyester copolymer. Flame retardancy is copolymerized in an amount of 0.05 to 0.5 mol% and the layered compound is contained in an amount of 0.1 to 5% by weight based on the polyester copolymer composition. Polyester copolymer composition.
2. The flame retardant polyester copolymer composition according to the above 1, wherein the layered compound according to the above 1 has an average particle diameter in the range of 5 to 100 nm.
3. 2. The flame retardant polyester copolymer composition according to 1 above, wherein the layered compound according to 1 is a layered silicate.
4). When heated at a rate of temperature increase of 10 ° C./min from room temperature in a nitrogen atmosphere, the amount of heating residue when reaching 600 ° C. is 15% by weight or more and heated at a rate of temperature increase of 10 ° C./min from room temperature in an air atmosphere The flame-retardant polyester copolymer composition according to any one of the above 1 to 3, wherein the weight loss starting temperature is 405 ° C or higher.
5. A flame retardant polyester fiber having a LOI value of 27 or more, obtained by melt spinning the flame retardant polyester copolymer composition according to any one of the above 1 to 4.

  According to the present invention, it is possible to obtain a highly flame-retardant polyester copolymer composition that suppresses drip during combustion, and has excellent drip-resistant flame resistance when formed into molded articles such as fibers, films, and resins. And a molded article having good physical properties and heat resistance can be obtained. Unlike conventional drip-type flame-retardant polyester fibers, polyester fiber produced by melt spinning the polyester copolymer composition of the present invention exhibits drip-type flame-retardant properties, so that drip at the flame-ignited portion is suppressed. Is done. For this reason, it is possible to prevent the risk of burns and spread of fire due to flammables and melts, so that it can be suitably used for home / living textile applications such as curtains, interiors and chairs, clothing applications, industrial applications, etc. .

  The polyester referred to in the present invention is mainly a polyalkylene terephthalate-based polyester having terephthalic acid as a main difunctional carboxylic acid component and ethylene glycol, butylene glycol, trimethylene glycol or the like as a main glycol component.

  Such polyester is synthesized by any method. In the case of polyethylene terephthalate (PET), which is a typical polyester, terephthalic acid and ethylene glycol are usually esterified directly, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol. Or the reaction of the first stage in which terephthalic acid and ethylene oxide are reacted to form a glycol ester of terephthalic acid and / or its low polymer, and the reaction product of the first stage is heated under reduced pressure to obtain the desired It is produced by a second stage reaction in which a polycondensation reaction is carried out until a polymerization degree of

  In the flame-retardant polyester copolymer of the present invention, a phosphaphenanthrene-based organophosphorus compound represented by the following general formula (1) is copolymerized as the first essential copolymer component in the polyester. It is necessary.

In Formula (1), R ₁ is a monovalent ester-forming functional group, R ₂ and R ₃ are the same or different groups, each having a monovalent hydrocarbon group having 1 to 10 carbon atoms and Selected from R ₁ , A represents a divalent or trivalent organic residue. n1 is 1 or 2, and n2 and n3 each represents an integer of 0 to 4.

  Preferable specific examples of such organic phosphorus compounds include compounds represented by the following formulas (a) to (c) and di (β-hydroxyethyl) esters thereof.

  The amount of copolymerization of the organophosphorus compound, which is the first essential copolymerization component, must be such that the content of phosphorus atoms in the polyester copolymer composition is in the range of 0.3 to 1.5% by weight. is there. A preferable phosphorus atom content is in the range of 0.5 to 1.0% by weight, more preferably in the range of 0.6 to 0.9% by weight. If the copolymerization amount of the organophosphorus compound is too small, the self-extinguishing property of the resulting polyester copolymer composition will be insufficient. On the other hand, if the copolymerization amount of the organophosphorus compound is too large, drip resistance will be insufficient, and it is difficult to achieve the object of the present invention.

  In the flame-retardant polyester copolymer composition of the present invention, an organic sulfonate represented by the following general formula (2) is copolymerized as a second essential copolymerization component in addition to the organic phosphorus compound.

In the above general formula (2), Z is an aromatic hydrocarbon group or aliphatic hydrocarbon group, X ₁ is an ester-forming functional group, X ₂ is the same or different ester-forming functional group or hydrogen atom as X ₁ , M Represents an alkali metal, alkaline earth metal or quaternary phosphonium, and m represents 1 or 2.

  That is, Z in the general formula (2) is an aromatic hydrocarbon group or an aliphatic hydrocarbon group, preferably an aromatic hydrocarbon group having 6 to 15 carbon atoms or an aliphatic hydrocarbon group having 10 or less carbon atoms. It is. Particularly preferred Z is an aromatic hydrocarbon group having 6 to 12 carbon atoms, particularly a benzene ring. M is an alkali metal, alkaline earth metal or quaternary phosphonium, and m is 1 or 2. Among these, those in which M is an alkali metal (for example, lithium, sodium or potassium) or quaternary phosphonium and m is 1 are preferable.

X ₁ represents an ester-forming functional group as described above, and X ₂ represents an ester-forming functional group that is the same as or different from X ₁ or represents a hydrogen atom, and is preferably an ester-forming functional group. The ester-forming functional group may be any group that reacts with and bonds to the main chain or terminal of the polyester copolymer, and specifically includes the following groups.

（上記式中、Ｒ’は低級アルキル基またはフェニル基を示し、ａおよびｄは１〜１０の整数を示し、ｂは２〜６の整数を示す。）

(In the above formula, R ′ represents a lower alkyl group or a phenyl group, a and d represent an integer of 1 to 10, and b represents an integer of 2 to 6.)

  Preferable specific examples of the organic sulfonate represented by the general formula (2) include sodium 3,5-dicarbomethoxybenzenesulfonate, potassium 3,5-dicarbomethoxybenzenesulfonate, 3,5-dicarbo Lithium methoxybenzenesulfonate, sodium 3,5-dicarboxybenzenesulfonate, potassium 3,5-dicarboxybenzenesulfonate, lithium 3,5-dicarboxybenzenesulfonate, 3,5-di (β-hydroxyethoxycarbonyl) ) Sodium benzenesulfonate, potassium 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonate, lithium 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonate, 2,6-dicarbomethoxynaphthalene-4 -Sodium sulfonate, 2,6-di Carbomethoxynaphthalene-4-sulfonate potassium, 2,6-dicarbomethoxynaphthalene-4-sulfonate lithium, 2,6-dicarboxynaphthalene-4-sulfonate sodium, 2,6-dicarbomethoxysphthalene-1 -Sodium sulfonate, 2,6-dicarbomethoxynaphthalene-3-sodium sulfonate, 2,6-dicarbomethoxynaphthalene-4,8-sodium disulfonate, 2,6-dicarboxynaphthalene-4,8-disulfone Acid sodium, sodium 2,5-bis (hydroethoxy) benzenesulfonate, methyl m-Nasulfobenzoate, m-Nasulfobenzoic acid, α-sodium sulfosuccinic acid, tetrabutylphosphonium 3,5-dicarboxybenzenesulfonate 3,5-dicarboxybenzenesulfo Tetrabutylphosphonium acid, ethyl tributylphosphonium 3,5-dicarboxybenzenesulfonate, benzyltributylphosphonium 3,5-dicarboxybenzenesulfonate, phenyltributylphosphonium 3,5-dicarboxybenzenesulfonate, 3,5-dicarboxylate Tetraphenylphosphonium carboxybenzenesulfonate, butyltriphenylphosphonium 3,5-dicarboxybenzenesulfonate, benzyltriphenylphosphonium 3,5-dicarboxybenzenesulfonate, tetrabutylphosphonium 3,5-dicarbomethoxybenzenesulfonate , Ethyl tributylphosphonium 3,5-dicarbomethoxybenzenesulfonate, benzyltributylphosphonium 3,5-dicarbomethoxybenzenesulfonate, 3,5- Diphenylmethoxybenzenesulfonate phenyltributylphosphonium, 3,5-dicarbomethoxybenzenesulfonate tetraphenylphosphonium, 3,5-dicarbomethoxybenzenesulfonate ethyltriphenylphosphonium, 3,5-dicarbomethoxybenzenesulfone Butyl triphenyl phosphonium acid, benzyl triphenyl phosphonium 3,5-dicarbomethoxybenzene sulfonate, tetrabutyl phosphonium 3-carboxybenzene sulfonate, tetraphenyl phosphonium 3-carboxybenzene sulfonate, tetra tetra carbomethoxy benzene sulfonate Butylphosphonium, 3-carbomethoxybenzenesulfonic acid tetraphenylphosphonium salt, 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfone Tetrabutylphosphonium acid, 3,5-di (β-hydroxyethoxycarbonyl) benzenesulfonic acid tetraphenylphosphonium, 3- (β-hydroxyethoxycarbonyl) benzenesulfonic acid tetrabutylphosphonium, 3- (β-hydroxyethoxycarbonyl) Tetraphenylphosphonium benzenesulfonate, tetrabutylphosphonium 4-hydroxyethoxybenzenesulfonate, tetrabutylphosphonium 2,6-dicarboxynaphthalene-4-sulfonate, methyl m-tetrabutylphosphoniumsulfobenzoate, m-tetrabutylphosphonium Examples thereof include sulfobenzoic acid and α-tetrabutylphosphonium sulfosuccinic acid. The organic sulfonate may be used alone or in combination of two or more.

  The proportion of copolymerization of the organic sulfonate with the polyester copolymer is 0.05 mol% or more and 0.5 mol% with respect to the total acid component (excluding the organic sulfonate) constituting the polyester copolymer. The range is less than 0.1, and the range of 0.1 to 0.4 mol% is preferable. When the copolymerization ratio is less than 0.05 mol%, the drip resistance of the obtained polyester copolymer becomes insufficient, and when it exceeds 0.5 mol%, the self-extinguishing property of the polyester copolymer is insufficient. In addition, physical properties such as strength and heat resistance are deteriorated in the finally obtained molded article such as fiber.

  Thus, only when a specific amount of each of the above organic phosphorus compound and organic sulfonate is copolymerized, a special effect of becoming a copolymer having both drip resistance and self-extinguishing properties is exhibited. This was also unexpected for the present inventors.

  The polyester copolymer of the present invention is substantially non-dyeable to the cationic dye because of the small amount of copolymerization of the organic sulfonate. In the present invention, the non-dyeing property of the cationic dye means that the dyeing evaluation after dyeing becomes a rating of 3 or less when dyeing is carried out by the dyeing method described in Examples described later.

  In order to copolymerize the organophosphorus compound and the organosulfonate in the polyester, it is preferable to carry out the reaction at any stage before the completion of the synthesis of the polyester, preferably at the beginning of the reaction in the second stage, specifically, The reaction product may be added at any stage before the intrinsic viscosity of the reaction product reaches 0.3 dl / g.

  The flame retardant polyester copolymer composition of the present invention needs to contain a layered compound. A layered compound is a compound in which atoms that are strongly bonded two-dimensionally form a plate-like layer, and these layers are stacked to form a crystal. It has the characteristics that it is easy to take in, and peeling between layers is possible. Specific layered compounds in the present invention include silicates, titanates such as potassium titanate phosphates such as zirconium phosphate, tungstates such as sodium tungstate, uranates such as sodium uranate, Examples thereof include one or more compounds selected from the group consisting of vanadates such as potassium vanadate, molybdates such as magnesium molybdate, niobates such as potassium niobate, and graphite. Of these, layered silicates are preferred from the viewpoint of availability and handling.

  The layered silicate is formed mainly from a tetrahedral sheet of silicon oxide and an octahedral sheet of mainly metal hydroxide, and examples thereof include smectite clay and swellable mica.

The smectite clay is a natural or synthesized one represented by the following general formula (3).

In the general formula (3), X ¹ is one or more selected from the group consisting of K, Na, 1 / 2Ca and 1 / 2Mg, and Y ¹ is Mg, Fe, Mn, Ni, Zn, Li, Al. And at least one selected from the group consisting of Cr, and Z ¹ is at least one selected from the group consisting of Si and Al (except when Z ¹ is only Al). H ₂ O represents water molecules bonded to interlayer ions, but n varies significantly depending on interlayer ions and relative humidity.

  Specific examples of such smectite group clays include, for example, montmorillonite, beidellite, nontronite, saponite, iron saponite, hectorite, soconite, stevensite, bentonite, and the like, substitution products, derivatives or mixtures thereof. Of these, montmorillonite, hectorite, and bentonite are preferable from the viewpoints of peelability between layers of the layered compound and fine dispersibility in the flame-retardant polyester copolymer composition.

The swellable mica is natural or synthesized represented by the following general formula (4).

In the general formula (4), X ² is at least one selected from the group consisting of Li, Na, K, Rb, Ca, Ba and Sr, and Y ² is Mg, Fe, Mn, Ni, Li and Al. Z ² is one or more selected from the group consisting of Si, Ge, Fe, B and Al (provided that Z ² is only Ge, Fe, B and Al). Except). These have the property of swelling in water, a polar solvent compatible with water at an arbitrary ratio, or a mixed solvent of water and the polar solvent. For example, lithium-type teniolite, sodium-type teniolite, lithium-type tetrasilicon mica, sodium-type tetrasilicon mica, etc., or their substitutes, derivatives, or mixtures thereof can be used. Of these, lithium-type tetrasilicon mica and sodium-type tetrasilicon mica are preferable in terms of the peelability between the layers of the layered compound and the fine dispersibility in the polyester copolymer composition.

Some of the above swellable mica have a structure similar to that of vermiculites, and such vermiculite equivalents can also be used. The vermiculite-equivalent products include a three octahedron type and a two octahedron type. Here, the trioctahedral type refers to a divalent metal ion in an octahedron sheet in which an octahedron surrounded by six OH ⁻ or O ²⁻ in a two-dimensional manner shares a ridge. All octagonal metal ion positions are full, including the octahedron type, which means that one-third of the octahedral metal ion positions are vacant like the octahedron containing trivalent metal ions. It means what is.

  The crystal structure of the layered silicate has a plate-like crystal structure, and the two orthogonal axes in the plane of the plate-like crystal are called a-axis and b-axis, and intersect perpendicularly to the plate-like crystal plane. The axis to be called is the c axis. In the present invention, a highly pure material that is regularly stacked in the c-axis direction is preferable, but so-called mixed layer minerals in which the crystal period is disturbed and plural kinds of crystal structures are intermingled can also be used.

  The above layered silicates may be used alone or in combination of two or more. Among these, montmorillonite, bentonite, hectorite, or swellable mica having sodium ions between layers can be mentioned as preferable examples.

  The above layered compound may be added in any process from the above-described polyester copolymer polymerization stage to melt molding into a molded body such as a fiber, film, resin, etc., polymerization addition method, melt kneading method, master batch The manufacturing method by law etc. is arbitrarily applied.

  In the case of applying the polymerization addition method, for example, the layered compound and the dispersion medium are preliminarily stirred and mixed using a known wet stirrer to form a dispersion, and at any stage before the above-described polyester synthesis is completed, Preferably, it may be added at any stage prior to the initial stage of the second stage reaction. In this case, a polar solvent such as ethylene glycol is preferably employed as the dispersion medium. The wet stirrer includes a high speed stirrer in which a stirring blade rotates at a high speed, a wet mill that wet pulverizes a sample in a gap between a rotor and a stator that is subjected to a high shear breaking speed, and a mechanical medium that uses a hard medium. Wet pulverizers, wet collision pulverizers that cause a sample to collide at high speed with a jet nozzle, wet ultrasonic pulverizers that use ultrasonic waves, and the like are preferably employed.

  When applying the melt mixing method, a method of melt kneading the polyester copolymer and the layered compound using various general kneaders is preferably employed. Examples of the kneader include a single screw extruder, a twin screw extruder, a roll, a Banbury mixer, and a kneader. A kneader with high shear efficiency is particularly preferable.

  In the present invention, the content of the above layered compound is in the range of 0.1 to 5% by weight, preferably in the range of 0.3 to 3% by weight, and more preferably in the range of 0.1 to 5% by weight with respect to the polyester copolymer composition. It is in the range of 5 to 2% by weight. When the content of the layered compound is less than 0.1% by weight, the drip resistance and self-extinguishing properties of the polyester copolymer composition obtained become insufficient, and when the content exceeds 5% by weight, the fiber finally obtained, etc. Thus, the physical properties and moldability of the molded article are lowered.

  In the polyester copolymer composition, the layered compound was obtained by observing the area equivalent circle diameter of 1000 layered compounds by observation with a transmission electron microscope, which will be described later. It is preferably in the range of 7 to 60 nm, particularly 10 to 30 nm. When the average particle size is in the above range, the drip resistance and the self-extinguishing property can be further improved, and the physical properties and moldability of the molded article such as the fiber finally obtained can be improved.

The flame retardant polyester copolymer composition of the present invention may contain optional additives such as an anti-coloring agent, a heat-resistant agent, a matting agent, a coloring agent, and particles as necessary.
The flame retardant polyester copolymer composition produced in this way is 600 ° C. when heated at a rate of temperature increase of 10 ° C./min from room temperature in a nitrogen atmosphere in an analysis using a TGA thermogravimetric apparatus. The amount of heating residue at the time of arrival is 15% by weight or more, in particular 20 to 25% by weight, and the weight loss starting temperature when heated at a heating rate of 10 ° C./min from room temperature in an air atmosphere is 405 ° C. or more, In particular, a temperature of 410 to 415 ° C. is preferable for obtaining a drip-proof flame resistance. A copolymer having such preferable characteristics can be obtained by appropriately adjusting the copolymerization ratio of each copolymer component and the content of the layered compound.

  In order to shape | mold the flame-retardant polyester copolymer composition of this invention, it is not necessary to employ | adopt a special method, The melt molding method of normal polyester is employ | adopted arbitrarily. For example, when forming into a fiber, the fiber spun may be a solid fiber which does not have a hollow part, or may be a hollow fiber which has a hollow part. Further, the outer shape and the shape of the hollow portion in the cross section of the fiber to be spun may be circular or irregular. As a spinning method, a method of melt spinning at a speed of 500 to 2500 m / min, drawing and heat treatment, a method of melt spinning at a speed of 1500 to 5000 m / min, and performing drawing and false twisting simultaneously or successively, 5000 m Spinning conditions such as a method of performing melt spinning at a high speed of at least / min and omitting the drawing step depending on the application may be arbitrarily adopted.

  Thus, the flame retardant polyester fiber produced from the flame retardant polyester copolymer composition by the melt spinning method has an LOI value (limit oxygen index) of 27 or more, particularly 28 to 31. preferable. If the LOI value (limit oxygen index) of the fiber is less than 27, the flame retardancy may be insufficient in applications where the fiber is mixed with other fibers.

  The flame-retardant polyester copolymer composition of the present invention can be formed into a molded product such as a film or a sheet, and any molding conditions can be employed. For example, an arbitrary condition such as a method of applying anisotropy by applying tension only in one direction after film formation, a method of stretching in two directions at the same time or in an arbitrary order, a method of multi-stage stretching of two or more steps is adopted.

  Thus, according to the present invention, it is possible to obtain a highly flame-retardant polyester copolymer that suppresses drip at the time of combustion, and has excellent drip-resistant flame resistance when formed into a molded body such as a fiber, film, or resin. Can be obtained. Unlike the conventional drip-type flame-retardant polyester fiber, the polyester fiber produced by melt spinning the polyester copolymer of the present invention exhibits a drip-proof flame resistance, so that the drip at the flame-bonding portion It is suppressed. For this reason, it is possible to prevent the risk of burns and spread of fire due to flammables and melts, so that it can be suitably used for home / living textile applications such as curtains, interiors and chairs, clothing applications, industrial applications, etc. .

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited by these. In the examples and comparative examples, “parts” and “%” respectively represent “parts by weight” and “% by weight” unless otherwise specified. Each measured value is a value measured by the following method.

(1) Amount of heating residue when reaching 600 ° C .:
In the analysis using the TGA thermogravimetry apparatus (Mettler Toledo thermogravimetry apparatus TGA851e), when the dry polymer sample was heated from room temperature to 10 ° C./min in a nitrogen atmosphere at the time of reaching 600 ° C. The amount of heating residue was displayed as a value relative to the sample weight at the start of measurement at room temperature.

(2) Weight loss start temperature:
Using a TGA thermogravimetry apparatus (Metra Toledo thermogravimetry apparatus TGA851e), a thermogravimetric curve was measured when the dried polymer sample was heated from room temperature to 10 ° C./min in an air atmosphere. The weight loss starting temperature was determined according to K 7120.

(3) Average particle size of the layered compound:
The resin composition in a chip state has a thickness that is larger than the average particle diameter of each layered compound in the direction orthogonal to the extrusion direction of the resin composition when being molded into the chip shape, and is several times the average particle diameter. Slice with an ultramicrotome within a thickness of several tens nm to several hundreds nm. When the resin composition is a fiber, it is an ultramicrotome in the direction perpendicular to the fiber axis direction, and when the resin composition is a film or a hollow molded body, the direction is perpendicular to the extrusion direction during film formation or molding. Slice. The sliced ultrathin section is enlarged to several thousand times to 100,000 times by a transmission electron microscope to obtain individual area equivalent circle diameters for 1000 layered compounds, and the average value thereof is the average particle diameter of the layered compounds. It was.

(4) Yarn strength:
A tensile test using Tensilon RTC-1210A type manufactured by Orientec Co., Ltd. was carried out, and the tensile elongation curve was obtained (yarn length 20 cm, tensile speed 20 cm / min).

(5) LOI value (limit oxygen index) of fiber fabric:
Measured according to JIS L 1091 (issued in 1999) E method E-3 (glass fiber sewing).

(6) Combustion test of tubular knitted fabric sample:
The number of flame contacts (average number of flame contacts of four samples) of the tubular knitted fabric sample was evaluated by the JISL-1091D method (45 ° coil method) (the higher the average number of flame contacts, the higher the flame resistance). At the same time, in accordance with the JISL-1091D method (45 ° coil method), the number of drip cycles (average number of drip cycles of four samples) until the 10 cm width × 1 g winding tubular knitted fabric sample was all burned out was evaluated (average drip number is Less drip resistance is higher).

[Example 1]
100 parts of dimethyl terephthalate, 0.16 part of sodium 3,5-dicarbomethoxybenzenesulfonate (0.1 mol% based on dimethyl terephthalate), 60 parts of ethylene glycol, 0.06 part of manganese acetate tetrahydrate ( 0.03 mol% with respect to dimethyl terephthalate), 0.004 part of cobalt acetate tetrahydrate as a color adjuster (0.003 mol% with respect to dimethyl terephthalate), and sodium acetate 3 water as an ether by-product inhibitor 0.02 parts of salt (0.03 mol% with respect to dimethyl terephthalate) was charged into a transesterification vessel, and the methanol produced by heating from 140 ° C to 220 ° C over 4 hours in a nitrogen gas atmosphere was removed from the system. The ester exchange reaction was carried out while distilling off. After the transesterification reaction, 0.026 part of trimethyl phosphate (0.036 mol% based on dimethyl terephthalate) was added as a stabilizer. Then 10 minutes later, 0.04 part of antimony trioxide (0.027 mol% with respect to dimethyl terephthalate) was added, and 10 minutes later, a bead-type wet fine particle dispersion pulverizer was used in advance under a stirring speed of 1700 rpm. 50 parts of 2% ethylene glycol dispersion (0.92% as smectite SWN in the polyester copolymer composition) of smectite SWN (manufactured by Co-op Chemical) prepared by time circulation treatment was added. At the same time, the temperature was raised to 240 ° C. while expelling excess ethylene glycol, and then transferred to a polymerization can.

  15.4 parts of a 63% ethylene glycol solution of a di (β-hydroxyethyl) ester of an organophosphorus compound represented by the above formula (a) in a polymerization can (0.64% as a phosphorus atom in the polyester copolymer composition) Then, the pressure was reduced from 760 Torr to 1 Torr over 1 hour, and at the same time, the temperature was raised from 240 ° C. to 280 ° C. over 1 hour 30 minutes. Polymerization was further performed for 2 hours at a polymerization temperature of 280 ° C. under a reduced pressure of 1 Torr or less. The obtained polymer was chipped according to a conventional method. This chip was subjected to TGA thermogravimetry and a combustion test. The results are shown in Table 2.

  Further, this chip was dried according to a conventional method, and then melt-spun at 285 ° C. using a spinneret having 24 circular spinning holes having a hole diameter of 0.3 mm. Next, the obtained undrawn yarn was drawn and heat-treated using a heating roller at 84 ° C. and a plate heater at 180 ° C. at a draw ratio such that the elongation of the drawn yarn finally obtained was 30%. A drawn yarn having a strength of 4.3 cN / dtex with a / 24 filament was obtained. Using the obtained drawn yarn, a tubular knitted fabric was knitted according to a conventional method, subjected to scouring and presetting, and then the LOI value was measured. The results were as shown in Table 1. As a result of observing the dispersion state of the smectite SWN in the fiber with a transmission electron microscope, the smectite SWN was dispersed in a plate shape having a layer thickness of 10 to 40 nm and a layer length of 30 to 120 nm.

[Examples 2 to 7 and Comparative Examples 1 to 4]
The same procedure as in Example 1 was conducted except that the amounts of sodium 3,5-dicarbomethoxybenzenesulfonate, sodium acetate trihydrate and smectite SWN used in Example 1 were changed to those shown in Table 1. The results are shown in Table 1.

[Example 8]
The same procedure as in Example 1 was performed except that smectite SAN (manufactured by Co-op Chemical) was used instead of the smectite SWN used in Example 1. The results are shown in Table 1.

[Example 9]
The same procedure as in Example 1 was performed except that swellable mica ME / e (manufactured by Co-op Chemical) was used instead of the smectite SWN used in Example 1. The results are shown in Table 1.

[Example 10]
The same procedure as in Example 1 was carried out except that m-Nasulfobenzoic acid was used instead of sodium 3,5-dicarbomethoxybenzenesulfonate used in Example 1 and the addition time was changed to after the end of the transesterification reaction. It was. The results were as shown in Table 1.

  According to the present invention, it is possible to obtain a highly flame-retardant polyester copolymer composition that suppresses drip during combustion, and has excellent drip-resistant flame resistance when formed into molded articles such as fibers, films, and resins. Can be obtained. Unlike conventional drip-type flame-retardant polyester fibers, polyester fiber produced by melt spinning the polyester copolymer composition of the present invention exhibits drip-type flame-retardant properties, so that drip at the flame-ignited portion is suppressed. Is done. For this reason, it is possible to prevent the risk of burns and spread of fire due to flammables and melts, so that it can be suitably used for home / living textile applications such as curtains, interiors and chairs, clothing applications, industrial applications, etc. .

Claims (5)

A polyester copolymer composition comprising a polyester copolymer and a layered compound,
In the polyester copolymer, the organophosphorus compound represented by the following general formula (1) is represented by 0.3 to 1.5% by weight of phosphorus atom based on the weight of the composition and the following general formula (2). The organic sulfonate is copolymerized in the range of 0.05 to 0.5 mol% based on the total acid component of the polyester copolymer (excluding the organic sulfonate), and layered The flame retardant polyester copolymer composition, wherein the compound is contained in an amount of 0.1 to 5% by weight based on the weight of the composition.

(In the formula, R ₁ is a monovalent ester-forming functional group, R ₂ and R ₃ are the same or different groups, and each is a monovalent hydrocarbon group having 1 to 10 carbon atoms and R ₁ . A is a divalent or trivalent organic residue, n1 is 1 or 2, and n2 and n3 each represents an integer of 0 to 4.)

Wherein Z is a trivalent aromatic hydrocarbon group or aliphatic hydrocarbon group, X ₁ is an ester-forming functional group, X ₂ is the same or different ester-forming functional group or hydrogen atom as X _1, and M is (Alkali metal, alkaline earth metal or quaternary phosphonium, m represents 1 or 2)   The flame retardant polyester copolymer composition according to claim 1, wherein the layered compound has an average particle diameter in the range of 5 to 100 nm.   The flame retardant polyester copolymer composition according to claim 1, wherein the layered compound is a layered silicate.   When heated at a rate of temperature increase of 10 ° C./min from room temperature in a nitrogen atmosphere, the amount of heating residue when reaching 600 ° C. is 15% by weight or more and heated at a rate of temperature increase of 10 ° C./min from room temperature in an air atmosphere The flame-retardant polyester copolymer composition according to any one of claims 1 to 3, wherein the weight loss starting temperature is 405 ° C or higher.   A flame retardant polyester fiber having a LOI value of 27 or more, obtained by melt spinning the flame retardant polyester copolymer composition according to claim 1.