JP2004183196A - Polyester conjugate fiber excellent in lightweight property - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide polyester conjugate fibers excellent in lightweight property together with light shielding properties and physical properties. <P>SOLUTION: The polyester conjugate fibers excellent in lightweight property, is a sea-island type polyester conjugate fiber comprising the polyester and a thermoplastic polymer (excluding polyester) not having a maleimide structure, wherein the island components comprise more than two components and not continuously dispersing in the fiber axis direction, the fiber has maximum dispersion diameter ≤5 μm in the cross section of the monofilament, ≤1.2 of fiber apparent specific gravity and 2.5 cN/dtex of fiber strength. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a polyester composite fiber having excellent lightness. More specifically, the present invention relates to a polyester composite fiber excellent in fiber properties such as strength, lightness and light-shielding properties.

  In recent years, the technological development of synthetic fibers has made remarkable progress, and fibers with various new functions have been developed. Among them, the development of fibers declaring “lightweight” has been Attention has been paid to the expansion, the popularity and establishment of outdoor sports, the expansion of lightweight or warm clothing, and the reduction of vehicle interior materials due to energy conservation.

For example, a composite fiber containing polymethylpentene (hereinafter abbreviated as PMP) as one component has been proposed (see Patent Document 1). In the conjugate fiber, a conjugate fiber in which the ratio of PMP in the conjugate fiber is 60 to 90% by weight and the fiber density is 1.0 g / cm ³ or less, or 30 to 50% by mass and the specific gravity of the fiber is 1.03 or less. By doing so, it is possible to make the fiber excellent in lightness, but conversely, it is necessary to include a large amount of PMP as a main component in order to achieve lightness of 1.0 g / cm ³ or less or 1.03. Therefore, the yarn properties were poor such as low fiber strength or low shrinkage. .

  A low specific gravity monofilament composed of a polyamide and a low specific gravity resin has been proposed (see Patent Document 2). The monofilament is intended to be used as a fishing line for fin fishing, and although it is intended to float above or below the water surface for 50 to 100 cm, it is inferior in Wash & Wear properties due to the use of polyamide, When used as clothing or industrial materials, there is a concern that the applications are limited. .

Further, a lightweight polyester fiber comprising a polyester resin and a styrene / maleimide resin having a molecular weight of 60,000 to 170,000 has been proposed (see Patent Document 3). Regarding the lightweight polyester, although the blending amount of the styrene / maleimide resin is 3 to 30% by weight and having fine cavities, the lightweight polyester can certainly be excellent in lightness, but styrene having a resin density of more than 1.0 The use of a maleimide resin, and the difference in the critical surface tension value of the styrene / maleimide resin with the polyester is less than 10 dyn / cm and the adhesiveness between the resins is good. Since excessive strength was generated in the medium to cause a large decrease in strength, and yellowing was a concern due to the inclusion of maleimide, the operability of drawing and the like and the yarn physical properties were not satisfactory.
Japanese Patent Application Laid-Open No. 09-157960 (Claims) JP-A-63-296641 JP-A-2000-154427 (Claims, paragraph [0012])

  It is an object of the present invention to provide a polyester composite fiber which solves the above-mentioned problems of the prior art, is excellent in light weight, and is excellent in fiber properties such as light-shielding property and strength.

  The present invention relates to a fiber excellent in light weight, and has intensively studied to obtain a polyester composite fiber excellent in fiber physical properties such as strength, which is useful for various clothing materials or industrial materials, and in particular, It has been found that by making a specific fiber structure and fiber physical properties containing the substance described above, the disadvantages of the prior art can be eliminated and further advantages can be provided, and the present invention has been achieved.

That is, the present invention is a sea-island-like polyester composite fiber comprising a polyester and a thermoplastic polymer having no maleimide structure (excluding polyester),
(1) In the cross section of a single fiber fiber, polyester is a sea component, and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island components are present discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter of the island component in the single fiber cross section is 5 μm or less.
And having voids in at least a part of the sea-island-like composite interface, an apparent specific gravity of the fiber of 1.2 or less, and a fiber strength of 2.5 cN / dtex or more. And polyester composite fibers.

  The polyester conjugate fiber obtained by the present invention is preferable because it has voids in the fiber and an apparent specific gravity of 1.2 or less, which is extremely excellent in lightness and light-shielding properties. Also, regarding the color of the fiber, since a thermoplastic polymer (excluding polyester) having no maleimide structure is used, there is no fear of yellowing (yellowing) of the fiber. There is no. Furthermore, in terms of fiber properties, since the fiber strength is 2.5 cN / dtex or more, in addition to uniform clothes such as white coats, underwear, T-shirts, shirts, swimwear, women's clothes, men's clothes, etc., lightweight for infants or elderly people In addition to being suitably used as clothing, sports clothing such as golf wear, gateball, baseball, tennis, soccer, table tennis, volleyball, basketball, rugby, American football, hockey, athletics, triathlon, speed skating, ice hockey, etc. And uniforms, or outdoor sports applications, such as shoes, bags, supporters, socks, and mountain climbing clothing. Furthermore, as interior materials, car interior materials such as carpets and wall materials for automobiles, ships, aircraft, railways, etc., and other ropes, tents, curtains, and blinds, which are required to be lighter due to energy savings. Also, it is suitably used for materials requiring light-shielding properties such as packing materials used for various types of transportation.

  The polyester composite fiber of the present invention is mainly composed of polyester. The polyester in the present invention is a polyester formed by an esterification reaction between a carboxylic acid and an alcohol, and is not particularly limited. For example, a polymer formed from an ester bond between a dicarboxylic acid compound and a diol compound Examples of such polymers include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polycyclohexanedimethanol terephthalate.

  Further, the polymer formed from the ester bond of these dicarboxylic acid compound and diol compound may be copolymerized with other components as long as the gist of the present invention is not impaired. Examples of the compound include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, anthracenedicarboxylic acid, phenanthylenedicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylethanedicarboxylic acid, adipic acid, sebacic acid, Aromatic, aliphatic and alicyclic dicarboxylic acids such as 4,4-cyclohexanedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, azelaic acid, dodecandionic acid and hexahydroterephthalic acid And derivatives thereof such as alkyl, alkoxy, allyl, aryl, amino, imino, and halides, adducts, structural isomers, and optical isomers. One of these dicarboxylic acid compounds can be used alone. Or two or more of them may be used in combination within a range that does not impair the gist of the invention.

  Further, as the copolymerization component, for example, diol compounds such as ethylene glycol, propylene glycol, butylene glycol, pentanediol, hexanediol, 1,4-cyclohexanedimethanol, neopentylglycol, hydroquinone, resorcinol, dihydroxybiphenyl, naphthalenediol, and anthracene Aromatic, aliphatic, alicyclic diol compounds such as diol, phenanthylene diol, 2,2-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl ether, bisphenol S and their alkyl, alkoxy, allyl, Derivatives such as aryl, amino, imino, and halide, adducts, structural isomers, and optical isomers can be mentioned. One of these diol compounds can be used alone. Also it may be, or in a range that does not impair the gist of the invention may be used in combination of two or more.

  Examples of the copolymerization component include a compound having a hydroxyl group and a carboxylic acid in one compound, that is, hydroxycarboxylic acid. Examples of the hydroxycarboxylic acid include lactic acid, 3-hydroxypropionate, and 3-hydroxybutyrate. , 3-hydroxybutyrate valerate, hydroxybenzoic acid, hydroxynaphthoic acid, hydroxyanthracene carboxylic acid, hydroxyphenanthrene carboxylic acid, (hydroxyphenyl) vinyl carboxylic acid, and other aromatic, aliphatic, and alicyclic diol compounds; Derivatives such as alkyl, alkoxy, allyl, aryl, amino, imino, and halide, adducts, structural isomers, and optical isomers can be given. One of these hydroxycarboxylic acids may be used alone. Or invention It may be used in combination of two or more in a range that does not impair the gist.

  Further, the polyester in the present invention may be a polymer in which one compound such as aromatic, aliphatic, or alicyclic is a hydroxycarboxylic acid compound having both a carboxylic acid and a hydroxyl group as a main repeating unit, and in particular, Although not limited, for example, such polymers include polylactic acid, poly (3-hydroxypropionate), poly (3-hydroxybutyrate), poly (3-hydroxybutyrate valerate), And poly (hydroxycarboxylic acids). In addition, these poly (hydroxycarboxylic acids) include aromatic, aliphatic, and alicyclic dicarboxylic acids, and aromatic compounds as long as the gist of the present invention is not impaired. Aliphatic, alicyclic diol components may be used, or a plurality of types of hydroxycarboxylic acids may be copolymerized. Even though it may.

  Among these polyesters, polyesters whose main repeating units are ethylene terephthalate, propylene terephthalate, butylene terephthalate or lactic acid are preferable, and polyesters whose main repeating units are ethylene terephthalate are more preferable.

  The polyester of the present invention is not particularly limited, and a polyester having an intrinsic viscosity (hereinafter referred to as IV) usually used for synthetic fibers can be used. Although not particularly limited, for example, in the case of polyethylene terephthalate, the IV is preferably 0.4 to 1.5, and more preferably 0.5 to 1.3. In the case of polypropylene terephthalate, the IV is preferably 0.7 to 2.0, more preferably 0.8 to 1.8. Alternatively, in the case of polybutylene terephthalate, the IV is preferably 0.6 to 1.5, and more preferably 0.7 to 1.4. Poly (hydroxycarboxylic acid) represented by polylactic acid is one of polyesters used in the present invention which is not evaluated by IV, and these are described in terms of weight average molecular weight (hereinafter sometimes simply referred to as average molecular weight). For example, polylactic acid having an average molecular weight of 50,000 to 500,000 is usually used, preferably 100,000 to 300,000, and an average of 150,000 to 250,000 in consideration of processability and spinnability. Polylactic acid having a molecular weight is more preferably used.

  Since the content of the polyester in the polyester composite fiber of the present invention is a main component, it is necessary that the content be 50% by weight or more. However, the content of 50% by weight or more is not particularly limited. Can be taken. In particular, the polyester content in the conjugate fiber is preferably 70% by weight or more, more preferably 80% by weight or more, and still more preferably 85% by weight or more, since it is preferable that the strength is high in fiber physical properties. .

  The polyester composite fiber of the present invention has, as an island component, a thermoplastic polymer having no maleimide structure (excluding polyester, which may be simply referred to as a thermoplastic polymer hereinafter). The thermoplastic polymer is substantially incompatible with the polyester because it forms islands in the cross section of the single fiber of the polyester composite fiber. In the present invention, the term "incompatible" means that the polyester and the thermoplastic polymer are not compatible with each other on the order of the molecular chain size of the polymer, and the average size of the islands formed by the thermoplastic polymer in the polyester (the shortest island) (Equivalent length) has a size of at least 10 nm. When the polyester and the thermoplastic polymer are compatible, that is, when the average size of the formed island is 10 nm or less, the island formed by the thermoplastic polymer has a very small size and has no voids or is lightweight. The voids required to obtain a fiber excellent in the fiber do not sufficiently appear, and as a result, the composite fiber is inferior in light weight, which is not preferable.

  The thermoplastic polymer (excluding polyester) of the present invention is not particularly limited as long as it does not have a maleimide structure and is incompatible with the polyester as described above, and various kinds of thermoplastic polymers can be used. Can be. For example, polyamide-based polymers, polyolefin-based polymers and other vinyl polymers, fluorine-based polymers, silicone-based polymers, elastomers, polycarbonate-based polymers, polyimide-based polymers formed by cyclopolycondensation of carboxylic anhydrides and diamines, dicarboxylic acids Polybenzimidazole polymers formed by the reaction of esters and diamines, as well as polysulfone polymers, aliphatic polyether polymers, aromatic polyether polymers, polyphenylene sulfide polymers, polyether ether ketone polymers, and poly Examples include synthetic polymers such as ether ketone ketone polymers, cellulose polymers, polymers derived from natural polymers such as chitin and chitosan derivatives, and various other engineering plastics.

  More specifically, for example, a polyolefin or other vinyl polymer synthesized by a mechanism in which a monomer having a vinyl group such as radical polymerization, anionic polymerization, or cationic polymerization is polymerized by an addition polymerization reaction or a ring-opening polymerization reaction. In the case of polyolefins, polyolefins include polyethylene, polypropylene, polybutylene, homopolymers or copolymers and derivatives of polymethylpentene, and other vinyl polymers include polystyrene, polyacrylic acid, and polymethacrylic acid. , Polymethyl methacrylate, polyacrylonitrile, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene chloride, polyvinylidene cyanide, and copolymers and derivatives thereof. Among the polymer synthesized by polymerization reaction, the critical surface tension described later, preferable from the viewpoint of density or glass transition temperature, (Tg), it may be mentioned first polyolefin polymer.

  Among the preferred polyolefin polymers, polyolefins whose main repeating structure is composed of olefins such as ethylene, propylene, butene, methylbutene, methylpentene, ethylpentene, hexene, ethylhexene, octene, decene, tetradecene, and octadecene are monomers. In addition to the polyolefin used as the above, for example, a polyolefin-based polymer having a cyclic structure, which is synthesized by ring-opening polymerization, addition polymerization, or the like of an alicyclic monomer and represented by the following Chemical Formula 1, Chemical Formula 2, or Chemical Formula 3, may be mentioned.

Here, each of the substituents X and Y is a group selected from hydrogen, an alkyl group, an alicyclic group, a cyano group, an alkyl ester group, and an alicyclic ester group.

  Examples of those having the structure include ARTON (registered trademark) manufactured by JSR Corporation and ZEONOR (registered trademark) manufactured by Zeon Corporation, and polyolefins having a cyclic structure are not particularly limited thereto. is not.

  These polyolefin-based polymers may be a homopolymer using one type of monomer alone, or a copolymer using a plurality of types, and further copolymerize an olefin with another vinyl compound. May be used. Specifically, as a copolymer component, a vinyl ester of a saturated aliphatic carboxylic acid having 2 to 6 carbon atoms, an acrylate ester and a methacrylate ester derived from an alcohol having 1 to 20 carbon atoms, Fumaric acid, maleic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, an unsaturated carboxylic acid such as nadic acid or an acid halide, amide, imide, acid anhydride and ester of the unsaturated carboxylic acid, Vinyl compounds such as styrene or a styrene derivative, acrylonitrile, an acrylonitrile derivative, a vinyloxyalkyl derivative (alcohol type or carboxylic acid type), and a vinyl compound having an alicyclic structure are exemplified. In particular, as the polyolefin-based polymer having the alicyclic structure as a copolymer component, for example, Apel (registered trademark) manufactured by Mitsui Chemicals, Inc. can be mentioned. Needless to say, the copolymerized polyolefin-based polymer having the alicyclic structure is However, the present invention is not limited to this.

  Among the polyolefin-based polymers exemplified as preferable among these thermoplastic polymers (excluding polyesters), polyolefin-based polymers containing propylene and / or methylpentene as a main repeating unit are preferred in that the formed fibers have a high void-forming property. Preferred are a polymer, a polyolefin-based polymer having a cyclic structure, and a copolymerized polyolefin-based polymer having an alicyclic structure.

  Examples of the thermoplastic polymer (excluding polyester) of the present invention include a polyether polymer in addition to the polyolefin polymer, and among them, an aromatic polyether polymer represented by polyphenylene ether is preferable. The polyphenylene ether may be a homopolymer in which phenylene oxide forms a main structure, or may be a copolymer obtained by copolymerizing a second component, and an additive may be added to the extent that the gist of the invention is not impaired. It may be a modified polyphenylene ether which is alloyed as a second component, ie, a polystyrene-based polymer, a polyamide-based polymer, a polyester-based polymer, a polyolefin-based polymer, or the like. Examples of the modified polyphenylene ether include Iupiace (registered trademark) and Remalloy (registered trademark) manufactured by Mitsubishi Engineering-Plastics Corporation, Noryl (registered trademark) manufactured by Nippon GE Plastics Co., Ltd., and Asahi Kasei Corporation Zylon (registered trademark), Artrex (registered trademark), Artly (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., and of course, aromatic polyether-based polymers mentioned as preferable thermoplastic polymers include these. However, the present invention is not limited to this.

  As described above, the thermoplastic polymer (excluding polyester) in the present invention needs to have no maleimide structure in the molecular skeleton. When the thermoplastic polymer has the maleimide structure, as described above, not only disadvantages such as yellowing of the formed fiber are observed, but also void formation due to too high affinity between the polyester and the thermoplastic polymer. This is not preferred because not only is the fiber not good enough to exhibit sufficient lightness, but also the light-shielding properties of the resulting fiber are poor due to poor void formation. Examples of the thermoplastic polymer having a maleimide structure include styrene maleimide polymer (type: MS-NA, etc.) manufactured by Denki Kagaku.

  As the thermoplastic polymer having no maleimide structure (excluding polyester) in the present invention, one kind of the above-mentioned polymers may be used alone, or a plurality of kinds may be used in combination as long as the gist of the invention is not impaired.

The thermoplastic polymer (excluding polyester) of the present invention preferably has a density of 1.0 g / cm ³ or less. When the density of the thermoplastic polymer is higher than 1.0 g / cm ³ , in order to reduce the apparent specific gravity of the fiber to 1.2 or less, for example, it is sufficient that a larger amount of the fiber is present when voids are formed. . However, it is necessary to pay attention to the fact that if there are too many voids, the strength is reduced and the yarn is easily broken.

The lower the density of the thermoplastic polymer is, the more suitable it is. Preferably, the density is 1.0 g / cm ³ or less, more preferably 0.95 g / cm ³ or less, and particularly preferably 0.90 g / cm ^3. It is as follows.

In the thermoplastic polymer (excluding polyester) of the present invention, those having a density of 1.0 g / cm ³ or less include, for example, the above-mentioned polyolefins, and ethylene, propylene, butene, methylbutene, methylpentene, ethylpentene, hexene, Ethylhexene, octene, decene, tetradecene, octadecene and the like can be used as monomers. These polyolefins may be a homopolymer using one type of monomer alone or a copolymer using a plurality of types. Further, a copolymer obtained by copolymerizing these olefins and another ethylenically unsaturated compound may be used. Specifically, a vinyl ester of a saturated aliphatic carboxylic acid having 2 to 6 carbon atoms, Acrylic esters and methacrylic esters derived from alcohols having 1 to 20 carbon atoms, and unsaturated carboxylic acids such as fumaric acid, maleic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, and nadic acid Acids or acid halides of the unsaturated carboxylic acids, amides, imides, acid anhydrides and esters, styrene or styrene derivatives, acrylonitrile or acrylonitrile derivatives, vinyloxyalkyl alcohols or derivatives thereof, vinyloxyalkylcarboxylic acids or the like Etch such as derivatives Emissions unsaturated compounds. One of these thermoplastic polymers other than polyester may be used alone, or two or more of them may be used in combination as long as the gist of the invention is not impaired. Among these thermoplastic polymers other than polyesters, homopolymers or copolymers of polyolefins in which ethylene and / or propylene and / or butylene and / or methylpentene account for 80 mol% or more are preferable, and propylene and / or methylpentene are preferred. Is more preferably 80% by mole or more of a homopolymer or a copolymer. In such a copolymer in which propylene and / or methylpentene occupies 80 mol% or more, the copolymerizable material is not particularly limited, but may be, for example, an aliphatic hydrocarbon having 5 or more carbon atoms, a fatty acid or the like. Examples include a vinyl compound having a cyclic hydrocarbon, an aromatic hydrocarbon, or a derivative thereof in a side chain.

  Although the average molecular weight of the thermoplastic polymer (excluding polyester) of the present invention is not particularly limited, the number average molecular weight is 2,000 in terms of excellent kneading with polyester, or shape retention in fibers, rigidity, and the like. It is preferably from 100 to 1000000, more preferably from 5000 to 5,000,000, and still more preferably from 10,000 to 1,000,000.

  The content of the thermoplastic polymer (excluding polyester) of the present invention is preferably from 1 to 30% by weight, and more preferably from 3 to 30% by weight, in view of excellent lightness and excellent yarn properties of the obtained polyester composite fiber. It is more preferably 20% by weight, and even more preferably 3 to 15% by weight.

  The thermoplastic polymer of the present invention (excluding polyester) is a thermoplastic interface in that the voids are easily formed at the composite interface of the polyester sea-island composite fiber of the present invention, and as a result, the specific gravity is smaller and the lightness is excellent. The polymer preferably has a critical surface tension of 10 to 35 dyn / cm, more preferably 12 to 30 dyn / cm, and still more preferably 15 to 25 dyn / cm. As the thermoplastic polymer satisfying the critical surface tension range, a homopolymer in which propylene and / or methylpentene occupies 80 mol% or more of the above-mentioned polyolefin comprising the olefin monomer or another ethylenically unsaturated compound. Alternatively, a copolymer is preferable, and a homopolymer or a copolymer in which methylpentene accounts for 80 mol% or more is more preferable. Also, the critical surface tension of the polyester of the present invention is not particularly limited, but it is preferable that the peelability with the thermoplastic polymer is higher when voids are generated as described above. It is preferably at least 35 dyn / cm, more preferably at least 38 dyn / cm. For example, polyester-based polymers such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate all have a critical surface tension of about 43 dyn / cm, and aliphatic polyesters such as polylactic acid and polyglycolic acid have a critical surface tension of about 36 dyn / cm. is there. Further, in the case of a copolymer component capable of further increasing the critical surface tension, for example, a copolymerized polyester obtained by copolymerizing a component having a polar group such as sulfoisophthalate or phosphate, the component having such a polar group is copolymerized. This is preferable because it can have a larger critical surface tension than a non-polymerized polyester. The critical surface tension is described later in G. Is defined in the following manner.

  The thermoplastic polymer (excluding polyester) of the present invention preferably has a melting point (Tm) of 150 ° C. or more in that the heat resistance of the polyester composite fiber is good and the lightness at high temperatures is excellent. , 180 ° C. or higher. Here, the melting point (Tm) refers to F.M. Is defined in the following manner. As the thermoplastic polymer satisfying the range of Tm, a homopolymer or a copolymer in which propylene and / or methylpentene occupies 80 mol% or more of the above-mentioned olefin monomer or other polyolefin comprising an ethylenically unsaturated compound. A polymer is preferable, and a homopolymer or a copolymer in which methylpentene accounts for 80 mol% or more is more preferable. A homopolymer or copolymer in which methylpentene accounts for 80 mol% or more is also preferable in that yellowing is unlikely to occur.

The melt viscosity of the thermoplastic polymer (excluding polyester) of the present invention is not particularly limited, and a polymer having a shear viscosity of 10 sec ^{-1 and} a shear viscosity of 1 to 10,000 Pascal second at the melt spinning temperature of the used polyester is usually used. And preferably between 10 and 5000 Pascal seconds.

  The thermoplastic polymer (excluding polyester) which forms an island component with the polyester composite fiber of the present invention is a glass of a thermoplastic polymer in that voids are easily generated when the polyester composite fiber is drawn, and the obtained fiber has high lightness. The transition temperature (Tg) is preferably 5 ° C. or higher than the glass transition temperature (Tgp) of the polyester. Here, the glass transition temperature (Tg) refers to the F.G. Is defined in the following manner. The Tg is more preferably higher than Tgp by 10 ° C. or higher, further preferably higher by 30 ° C. or higher, and particularly preferably higher by 50 ° C. or higher. When the Tg of the thermoplastic polymer is higher than that of the polyester by 5 ° C. or more, not only the void is generated during stretching at the interface peeling between the polyester and the thermoplastic polymer, but also the tearing and peeling of the thermoplastic polymer itself are generated. Further, also in melt spinning, the thermoplastic polymer is solidified at a higher temperature than the polyester to form an island structure advantageous for void generation, and is also preferable because it also improves the lightness. The glass transition temperature (Tg) of the thermoplastic polymer constituting the island component is preferably 85 ° C. or higher, more preferably 90 ° C. or higher, and more preferably 110 ° C., from the viewpoint that it is more suitable for void generation. The temperature is still more preferably at least 130 ° C. The glass transition temperature Tgp of each polyester is as follows: To 72 ° C. for polyethylene terephthalate, 47 ° C. for polypropylene terephthalate, 24 ° C. for polybutylene terephthalate, 58 ° C. for polylactic acid, and 87 ° C. for polycyclohexanedimethanol terephthalate. ° C and 122 ° C for polyethylene naphthalate.

  The thermoplastic polymer (excluding polyester) of the present invention is not particularly limited, but a flame retardant, a lubricant, an antioxidant, a crystal nucleating agent, an end group sealing agent, etc. are added as long as the gist of the invention is not impaired. An agent may be contained in a small amount.

  The method of adding the island component to the sea component in the present invention is not particularly limited. For example, in an ordinary polyester polymerization reaction, the addition is performed at an arbitrary stage before the termination of the polyester polymerization reaction. (B) a method in which a thermoplastic polymer other than polyester is added at the time of spinning the polyester, and the mixture is melt-kneaded at normal pressure or reduced pressure by a kneader such as an extruder or a static mixer; A method in which a thermoplastic polymer is added at a high concentration, a polyester to which a thermoplastic polymer other than the polyester is not added is simultaneously added and diluted by a kneader such as an extruder or a static mixer, and the mixture is melt-kneaded under normal pressure or reduced pressure. D) Thermoplastic polymers other than polyester Polyester that has been added to the ester and melt-kneaded at a high concentration under normal pressure or reduced pressure by a kneader such as an extruder or static mixer, and then a thermoplastic polymer other than polyester is not added by a kneader such as an extruder or a static mixer during spinning of the polyester. (E) a method of adding and kneading a thermoplastic polymer other than polyester to a polyester in a solution state, kneading the mixture, and subjecting the mixture to spinning, and (F) spinning of polyester. And a method in which a melt or a solution of a thermoplastic polymer other than polyester is discharged from a nozzle-shaped tube or the like at an arbitrary stage before the discharge so as to be contained in the polyester, and the above-mentioned (B) and (B) are preferable. Method C) or method D) is adopted

  In some cases, the polyester composite fiber of the present invention has poor compatibility between polyester and thermoplastic polymer (excluding polyester). Therefore, it is preferable to contain a compatibilizer. The compatibilizer in the present invention is a compound that changes the interaction at the composite interface when the island component is included in the sea component, enhances compatibility between the two, and controls the dispersion diameter of the island component. As the compatibilizer, a wide variety of compounds such as a low molecular weight compound or a high molecular weight compound can be adopted.For example, as the low molecular weight compound, sodium dodecylbenzenesulfonate or sodium alkyl sulfonate, glycerin monostearate, Anionic or cationic surfactants and amphoteric surfactants such as tetrabutylphosphonium para-aminobenzenesulfonate, poly (alkylene oxide) glycols such as polyethylene glycol, methoxypolyethylene glycol, polytetramethylene glycol and polypropylene glycol, and ethylene oxide / propylene A nonionic surfactant such as an oxide copolymer is exemplified.

  Further, as the high molecular compound listed as the compatibilizer, a high molecular compound having high compatibility or affinity with each of the polyester and the thermoplastic polymer other than the polyester may be used. Acrylate polymer, polymethacrylate polymer, poly (vinyl alcohol-ethylene) copolymer, poly (vinyl alcohol-propylene) copolymer, poly (vinyl alcohol-styrene) copolymer, poly (vinyl acetate-ethylene) copolymer, poly (vinyl acetate-) Vinyl-based polymers or copolymers such as propylene) copolymers and poly (vinyl acetate-styrene) copolymers, ionomers, polysaccharides and polyalkylenes having improved heat resistance and melt plasticity by chemically modifying side chains. Copolymers of alkylene oxide and each vinyl derivative, such as side or poly (alkylene oxide-ethylene) copolymers and poly (alkylene oxide-propylene) copolymers, or derivatives of polyalkylene oxides, copolymers of alkylene terephthalate and alkylene glycol, alkylene terephthalate and poly ( Polymers such as copolymers of (alkylene oxide) glycols, copolymers of alkylene terephthalate and polyalkylene diol, and the like can be mentioned. Among them, the effect as a compatibilizer is large, and considering that the yarn physical properties when the fiber of the present invention is formed are good, polystyrene-based polymers, polyacrylate-based polymers, polymethacrylate-based polymers, and alkylene terephthalates. Preference is given to copolymers of alkylene glycols, copolymers of alkylene terephthalate and poly (alkylene oxide) glycol, poly (alkylene oxide) glycols, copolymers of alkylene terephthalate and polyalkylene diol, or derivatives of these polymers.

  Specific examples of preferred alkylene terephthalate and polyalkylene diol, copolymers of alkylene terephthalate and alkylene glycol, copolymers of alkylene terephthalate and poly (alkylene oxide) glycol, and poly (alkylene oxide) glycol or derivatives thereof are described below. Needless to say, the compatibilizer in the present invention is not limited to these.

  As the copolymer of alkylene terephthalate and polyalkylene diol, alkylene terephthalate selected from ethylene terephthalate, propylene terephthalate, butylene terephthalate, pentamethylene terephthalate, hexamethylene terephthalate, etc., and polyalkylene diol selected from polyethylene diol, polybutylene diol, etc. And alkylene terephthalate and alkylene glycol may be used alone or in combination. Although not particularly limited, specific examples include a poly (ethylene terephthalate-polyethylene diol) copolymer, a poly (propylene terephthalate-polyethylene diol) copolymer, and a poly (butylene terephthalate-polybutylene diol) copolymer. .

  Examples of the copolymer of alkylene terephthalate and alkylene glycol include alkylene terephthalate selected from ethylene terephthalate, propylene terephthalate, butylene terephthalate, pentamethylene terephthalate, hexamethylene terephthalate, etc., and ethylene glycol, propylene glycol, butylene glycol (or tetramethylene glycol), pentane It is a copolymer comprising an alkylene glycol selected from methylene glycol and hexamethylene glycol, and each of alkylene terephthalate and alkylene glycol may be used alone or in combination. Although not particularly limited, specific examples include a polyethylene terephthalate-butylene glycol copolymer, a polypropylene terephthalate-ethylene glycol copolymer, and a polybutylene terephthalate-tetramethylene glycol copolymer.

  As the copolymer of alkylene terephthalate and poly (alkylene oxide) glycol, alkylene terephthalate selected from ethylene terephthalate, propylene terephthalate, butylene terephthalate, pentamethylene terephthalate, hexamethylene terephthalate, etc., and diethylene glycol, triethylene glycol, poly (ethylene oxide) glycol, A copolymer comprising poly (alkylene oxide) glycol selected from dipropylene glycol, poly (propylene oxide) glycol, poly (ethylene oxide-propylene oxide) glycol comprising a copolymer of ethylene oxide and propylene oxide, and alkylene terephthalate And poly (alkylene oxide) glycol in 1 It may be used by classes, or may be used in combination. Although not particularly limited, specifically, polyethylene terephthalate-diethylene glycol copolymer, polyethylene terephthalate-poly (ethylene oxide) glycol copolymer, polybutylene glycol-poly (ethylene oxide) glycol copolymer, polypropylene terephthalate-poly (ethylene oxide) glycol copolymer And the like.

The main chemical structure of poly (alkylene oxide) glycol or a derivative thereof is that a group (or group) in which carbon forms a main chain, such as an aliphatic, aromatic, or alicyclic group, and an oxygen atom are alternately bonded. Any material having such a repeating structure may be used. For example, poly (alkylene oxide) glycol having a single alkylene oxide as a repeating unit represented by the following general formula (1) can be used.
_{- [(CH 2) a -O} ] m - ··· (1)
Those satisfying the formula (1) include, for example, poly (ethylene oxide) glycol (a = 2), poly (propylene oxide) glycol (a = 3), poly (tetramethylene oxide) glycol (a = 4), and the like. Poly (alkylene oxide) glycol.

The poly (alkylene oxide) glycol may be, for example, an alternating, random, or block copolymer of different alkylene oxides as represented by the following general formula (2).
-{[(CH ₂ ) _a -O] _m -[(CH ₂ ) _b -O] _n ｝ _x- (2)
As satisfying the formula (2), for example, a poly (oxyethylene-oxypropylene) copolymer (a = 2 or 3, b = 2 or 3, and a and b may be the same or different. ), Poly (oxytetramethylene-oxyethylene-oxypropylene) copolymer (a = 1 or 2 or 3, b = 1 or 2 or 3, and a and b may be the same or different) And copolymers of different alkylene oxides.

  Further, as the poly (alkylene oxide) glycol, one kind of the polyalkylene oxide represented by the above general formula (1) or (2) may be used alone, or within a range not to impair the gist of the invention. A combination of two or more types may be used without departing from the spirit of the invention.

  One of these compatibilizers, which is a low molecular weight compound or a high molecular weight compound, may be used alone, or two or more may be used in combination within a range that does not impair the gist of the invention. Although not particularly limited, examples of the compatibilizer include Alcox (registered trademark) of polyethylene oxide manufactured by Meisei Chemical Industry, Hytrel (registered trademark) manufactured by Du Pont-Toray, and Estyrene, a polystyrene resin manufactured by Nippon Steel Chemical. (Registered trademark) and the like can be mentioned as preferable ones.

  As the content of the compatibilizer in the polyester composite fiber of the present invention, the content of the compatibilizer is that the compatibilization is more effectively expressed and the fiber properties of the obtained polyester composite fiber are excellent. Is preferably 10 to 200% by weight, more preferably 20 to 100% by weight, based on the island component.

  The method of adding the compatibilizer to the polyester in the present invention is not particularly limited. For example, in the usual polymerization reaction of polyester, (A) is added at any stage before the polymerization reaction of polyester is stopped. (B) a method in which a compatibilizer is added during spinning of a polyester and melt-kneaded at normal pressure or reduced pressure by a kneader such as an extruder or a static mixer; (C) a high concentration of the compatibilizer in a normal polyester polymerization reaction. And adding and diluting the polyester with no compatibilizer at the same time using a kneader such as an extruder or a static mixer, and melt-kneading under normal pressure or reduced pressure. (D) Adding the compatibilizer to the polyester Normal pressure or reduced pressure by a kneader such as an extruder or static mixer. After melt-kneading at a high concentration below, a method of simultaneously adding and diluting a polyester to which no compatibilizer has been added by a kneader such as an extruder or a static mixer during spinning of the polyester, and melt-kneading under normal pressure or reduced pressure, (E) A method in which a compatibilizing agent is added to the polyester in a solution state, kneaded, and then subjected to spinning. The method is not particularly limited, but is preferably (A), (B) or (C) described above. Method is adopted.

  The polyester composite fiber in the present invention needs to be in the form of a fiber. Fibers are those having an elongated shape and a length to apparent diameter ratio of at least 20 and include, for example, long fibers (filaments), short fibers (staples) made in the production of conventional synthetic fibers. ), And natural fibers such as cotton, wool, hemp, and silk. Further, the fiber diameter of the fiber is not particularly limited, but the fiber diameter is 0.01 to 5000 μm in terms of excellent fiber physical properties, or that the workability is further improved in forming a fabric. Is more preferred, more preferably 1000 μm or less, and even more preferably 200 μm or less. The cross-sectional shape of the fiber is not particularly limited, and examples thereof include a round shape, a polygonal shape, a multi-leaf shape, and a hollow shape, and a round shape is preferable in that the fiber has stable physical properties, or From the viewpoint of improving the lightness, a multi-leaf type or a hollow type is preferable. Although it is not particularly limited, as the hollow type, the shape of the spinning discharge hole is, for example, a C type or a well shape, and a hollow fiber is obtained with a discharge shape capable of forming a hollow, or a reagent is used. After a core-sheath fiber is obtained by using a component that can be eluted as a core component, a method of eluting the core component to obtain a hollow fiber may be used.

The polyester composite fiber in the present invention,
(1) In the cross section of a single fiber fiber, polyester is a sea component, and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island components are present discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter of the island component in the single fiber cross section is 5 μm or less.
It is a polyester conjugate fiber satisfying the condition. In the polyester composite fiber of the present invention, in the cross section of the single fiber yarn, the polyester is a sea component, the thermoplastic polymer (excluding polyester) is two or more island components, and the island components are discontinuously dispersed in the fiber axis direction. By virtue of this, the area of the composite interface between the sea component and the island component in the polyester composite fiber becomes very large, the number of voids existing in at least a part of the composite interface becomes very large, and the Excellent polyester composite fiber. However, when one island component and / or the island component is continuous (not dispersed) in the fiber axis direction in the cross section of the single fiber fiber, the obtained polyester composite fiber has a core-sheath type cross section. And / or a sea-island type composite fiber in which island components are continuously present in a lotus root shape. The area of the composite interface is very small, and voids are not generated or reduced, resulting in poor lightness. It is possible to confirm that the island components are dispersed and discontinuous in the fiber axis direction by observing the cross section in the fiber axis direction by a measuring method described later, but the discontinuity is not described. The ratio β / α between the diameter (α) of one dispersed island and the length (β) of the dispersed island in the fiber axis direction in the cross section of the single fiber of the island component is 1000 or less. A thermoplastic polymer other than polyester is present discontinuously dispersed in the fiber axis direction ", and β / α is preferably 100 or less, more preferably 10 or less.

  Further, when the maximum dispersion diameter of the island component in the single fiber cross section of the polyester composite fiber of the present invention is 5 μm or less, the area of the composite interface becomes very large as described above, and the void existing in at least a part of the composite interface. In addition to the fact that the polyester composite fiber is extremely high in weight and extremely lightweight, the generated voids are not excessively large and are unlikely to be fiber defects, so the fiber strength of the polyester composite fiber also decreases. Without being very good. However, when the maximum dispersion diameter of the island component in the cross section of a single fiber of a fiber is larger than 5 μm, the area of the composite interface is reduced, the number of voids is extremely reduced, the lightness is inferior, and the fiber strength is also low. This leads to very poor fiber properties, or poor fiber-forming properties and drawability in the production stage. The maximum dispersion diameter of the island component in the fiber single yarn cross section of the present invention is preferably smaller than the single yarn diameter of the fiber, more preferably 3 μm or less, more preferably 1 μm or less, and still more preferably 0.8 μm or less. is there. Further, the ratio of the maximum dispersion diameter of the island component to the diameter of the fiber single yarn cross section (in other words, the single fiber diameter) is not particularly limited as long as the maximum dispersion diameter is 5 μm or less as described above, but is more In view that voids are formed or fiber properties are excellent, the value of [single fiber diameter / maximum dispersed diameter of island component] is preferably 2 or more, more preferably 4 or more, and more preferably 10 or more. Is even more preferred.

  As described above, the polyester composite fiber of the present invention needs to have voids in at least a part of the composite interface. By having voids, the polyester composite fiber of the present invention is very excellent in lightness and is preferable. In addition, since the voids are fine, it is unlikely to be a defect in the fiber structure, and fiber strength is also excellent. Further, the porosity indicating the ratio of the volume of the voids in the fiber is not particularly limited, but the apparent specific gravity of the fiber of the present invention is 1.2 or less, and the fiber is more excellent in lightness. From the viewpoint, it is preferable to have a porosity of 15% or more, more preferably 25% or more. The method for developing the voids is not particularly limited, and any method may be used as long as it can apply a stress to develop the voids. For example, an undrawn yarn obtained by winding into a spinning yarn may be used. A method of stretching at a magnification, a method of continuously stretching at a high magnification without winding an undrawn yarn at the time of spinning, a method of drawing at a high speed in spinning, and the like, or heating the obtained yarn or applying a specific light By irradiating, for example, a method of shrinking the thermoplastic polymer other than the polyester in the polyester composite fiber, and the like, although any method can be adopted, respectively, in that the process is simple and the control of void generation is easy, A method in which the undrawn yarn obtained by winding into a spinning yarn is drawn at a high magnification, or a method in which the undrawn yarn is continuously drawn at a high magnification without winding the yarn during spinning is preferred. There.

  Although the polyester composite fiber of the present invention is not particularly limited, it is excellent in form stability and weather resistance, or in that it adopts shrinkage characteristics in various use environments in various materials for clothing or industrial use. The shrinkage when kept in warm water or boiling water (about 70 to 100 ° C.) for 15 minutes is preferably 50% or less, more preferably 30% or less, and further preferably 25% or less. More preferred.

  Further, the polyester composite fiber of the present invention is not particularly limited, but in addition to being excellent in form stability, taking into account the allowable deformation degree of various materials for clothing or industrial use, the fiber at 20 ° C. The elongation is preferably 100% or less, more preferably 60% or less, and even more preferably 45% or less. Although the lower limit of the elongation of the fiber is not particularly limited, it is preferably at least 3%, more preferably at least 5%, which can be achieved in production.

  Means for producing the polyester composite fiber of the present invention is not particularly limited, and a method for producing a synthetic fiber that is usually used can be employed.For example, a resin melt or a solution is simultaneously discharged from a nozzle, Although various manufacturing methods such as melt spinning, wet spinning, dry spinning, and dry-wet spinning can be adopted, the process is very simple, the productivity is excellent, and the cross-sectional shape of the fiber is free. The melt spinning method is preferred because it has the advantage of being controllable. And, in the case of fibers obtained by a method such as a melt spinning method, a wet spinning method, a dry spinning method, or a dry-wet spinning method, although not particularly limited, if necessary, once used in the present invention. After being cooled below the glass transition temperature of the polyester and preferably taken up at a take-up speed of 100 to 10000 m / min, without or once taken up, preferably stretched at a draw ratio of 1.5 or more or It is preferred that the film be stretched and false-twisted. In the drawing process, the polyester composite fiber is heated without heating or by a heated pin-like material, roller-like material, plate-like material, a liquid material such as hot water, or a non-contact type heater, etc. Or it is stretched in a plurality of stages. In the draw false twisting process, the polyester composite fiber is not heated after drawing, or a non-contact type liquid material such as a heated pin-like material, a roller-like material, a plate-like material, hot water, or a non-contact type. After heating with a heater or the like, false twisting is performed with a disk-shaped material or a belt-shaped material. The stretched or stretched false twisted polyester composite fiber is preferably wound as it is or after being heat-set, though not particularly limited.

  In the polyester composite fiber of the present invention, a polymer other than the polyester and the thermoplastic polymer (excluding polyester) can be blended as long as the effects of the present invention are not impaired.

  It is necessary that the apparent specific gravity of the polyester composite fiber in the present invention is 1.2 or less. When used as clothing for infants or the elderly, as well as when used as sports uniforms or outdoor clothing, the apparent specific gravity of the fiber is small, and it is a very favorable property that it has the same bulk (volume) and excellent lightness. Become. Furthermore, considering the case of using it as an industrial material, it is very preferable for transportation because the weight is reduced when carrying the same strength, and conversely, when the weight becomes the same, the strength becomes larger. It is very excellent because it can form a material having The apparent specific gravity of the polyester composite fiber is preferably 1.0 or less, more preferably 0.95 or less, still more preferably 0.90 or less, and most preferably 0.85 or less. Although the lower limit of the apparent specific gravity is not particularly limited, a fiber having an apparent specific gravity of usually 0.30 or more, preferably 0.35 or more can be achieved as a product that can be produced.

  It is necessary that the fiber strength of the polyester composite fiber in the present invention is 2.5 cN / dtex or more. As mentioned above, it is necessary to use a durable material not only when used as clothing for infants or the elderly, but also when used as sports uniforms or outdoor clothing, or when used as industrial materials. There is. Further, even when the workability of the fiber or the fabric is considered, the yarn physical properties are required to have high strength. The strength of the polyester composite fiber is preferably at least 4.0 cN / dtex, more preferably at least 4.5 cN / dtex, even more preferably at least 4.7 cN / dtex.

  The polyester conjugate fiber of the present invention may contain a small amount of additives such as a flame retardant, a lubricant, an antioxidant, a crystal nucleating agent, and a terminal group sealing agent as long as the gist of the invention is not impaired.

  The polyester composite fiber of the present invention has effects such as hygroscopicity, water absorption, and heat retention due to the voids formed in the fiber and the synergistic effect of the compatibilizer used. For example, regarding the hygroscopicity, when the polyester composite fiber of the present invention is partially or wholly used as a cloth for clothing, a more comfortable wearing feeling can be obtained without stickiness when worn. The value of the hygroscopicity index (ΔMR), which is an index of hygroscopicity, is preferably 0.10% or more, more preferably 0.20% or more. Here, ΔMR will be specifically described. This is a value obtained by subtracting the moisture absorption rate (MR1) at 20 ° C. and 65% RH from the moisture absorption rate (MR2) at 30 ° C. and 90% RH (ΔMR (%) = MR2). -MR1). ΔMR is a driving force for obtaining comfort by releasing moisture in the clothes when the clothes are worn to the outside air. The temperature in the clothes is 30 ° C., 90% when light to medium work or exercise is performed. RH is represented by an outside air temperature of 20 ° C. and 65% RH, and the difference between the two is taken. In the present invention, the ΔMR is used as an index as a measure of the hygroscopicity evaluation. The larger the ΔMR, the higher the hygroscopic capacity and the better the comfort when worn.

  The polyester composite fiber of the present invention is very useful as a fiber itself because of its excellent lightness, and the fiber can be used as it is. Or you may use it for all. The fabric in which the polyester composite fiber of the present invention is partially or wholly used is a fabric such as taffeta, twill, satin, desin, palace, georgette, flat knit, rubber knit, double-side knit, single tricot knit, half Knitting such as tricot knitting, non-woven fabric formed by methods such as chemical bond method, thermal bond method, needle punch method, water jet punch (spunlace) method, stitch bond method, felt method, etc., raw silk, twisted yarn, processing There is no particular limitation on the form of fibers such as yarn. Naturally, if it is a woven or knitted fabric, it may be subjected to ordinary scouring, dyeing, heat setting, etc., or if it is a non-woven fabric, a glazing press, an embossing press, compact processing, flexible processing, heat setting, etc. Physical processing, bonding processing, laminating processing, coating processing, antifouling processing, water repellent processing, antistatic processing, flameproofing processing, insectproofing processing, sanitary processing, foaming resin processing and other chemical processing processing, etc. Microwave application, ultrasonic application, far-infrared application, ultraviolet application, low-temperature plasma application, etc. may be applied to the product, and as a final form, it may be sewn as clothing.

  Further, the fabric in which the polyester composite fiber of the present invention is partially used is a synthetic fiber different from the polyester composite fiber of the present invention and the present invention, a semi-synthetic fiber, a natural fiber, and the like, for example, a cellulose fiber, wool, silk, A mixed fabric using at least one kind of fiber selected from a stretch fiber and an acetate fiber. Specifically, examples of the cellulose fiber include natural fibers such as cotton and hemp, steel ammonia rayon, rayon, polynosic, and the like.The content of the polyester composite fiber mixed with these cellulose fibers is not particularly limited. However, the content is preferably 25 to 75% in order to make use of the feeling, moisture absorbency, water absorbency, and antistatic property of the cellulose fiber and to make use of the light weight of the polyester composite fiber of the present invention. In addition, wool and silk used in the mixed fabric can be used as they are, and these wools or the content of the polyester composite fiber to be mixed with the silk can be used for the wool texture, warmth, bulkiness, and silk content. In order to make use of the texture and the squeaking sound and to make use of the lightweight property of the polyester composite fiber of the present invention, the content is preferably 25 to 75%. The stretch fibers used in the mixed fabric are not particularly limited, and polyester fibers represented by dry-spun or melt-spun polyurethane fibers, polybutylene terephthalate fibers and polytetramethylene glycol copolymerized polybutylene terephthalate fibers. In a mixed fabric using stretch fibers, the content of the polyester composite fiber is preferably about 60 to 98%. When the content of the polyester composite fiber exceeds 70%, the stretchability is suppressed, so that the polyester composite fiber can be used for outerwear, casual wear, and the like. If it is less than 70%, it can be used for innerwear, foundation, swimwear, etc. due to its elastic properties. The acetate fiber used in the mixed fabric is not particularly limited, and may be a diacetate fiber or a triacetate fiber. The content of the polyester composite fiber mixed with these acetate fibers is preferably 25 to 75% in order to make use of the feel, clarity, and luster of the acetate fiber and to make use of the light weight of the polyester composite fiber of the present invention.

  In these various mixed fabrics, the form and mixing method of the polyester composite fiber of the present invention are not particularly limited, and known methods can be used. For example, as a mixing method, a woven fabric used for a warp or a weft, a woven fabric such as a reversible woven fabric, a knitted fabric such as a tricot or Russell, and the like may be used.

  The fabric of the present invention, including the mixed fabric, may be dyed. For example, after knitting and weaving, it is preferable to take the steps of scouring, presetting, dyeing, and final setting by a conventional method. Further, if necessary, after scouring and before dyeing, it is also preferable to carry out an alkali weight reduction treatment by an ordinary method. The scouring is preferably performed in a temperature range of 40 to 98 ° C. In particular, in the case of mixing with a stretch fiber, it is more preferable to refine the fabric while relaxing it, because the elasticity is improved. It is possible to omit one or both of the heat setting before and after dyeing, but it is preferable to perform both in order to improve the form stability and dyeability of the fabric. The temperature of the heat setting is 120 to 190 ° C., preferably 140 to 180 ° C., and the heat setting time is 10 seconds to 5 minutes, preferably 20 seconds to 3 minutes.

  The polyester composite fiber of the present invention can be used, for example, in sports clothing (golf wear, gateball, baseball, tennis, soccer, table tennis, volleyball, basketball, rugby, American football, hockey, athletics, etc.) by utilizing the excellent lightweight properties and fiber properties. , Triathlon, speed skating, ice hockey and other uniforms), swimwear, infant clothing, women's clothing, elderly clothing, outdoor clothing (shoes, bags, supporters, socks, mountain climbing), etc. It is also suitably used for various vehicle interior materials such as railroads, airplanes, ships, etc., BCF, and packaging materials used for various transportations.

  Hereinafter, the present invention will be specifically and more specifically described with reference to Examples. In the present invention, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) will be described as an example of a fiber material, and examples will be described. However, the present invention is not limited to the following examples. The physical properties in the examples were measured by the following methods.

A. Measurement of fiber strength Using a Tensilon tensile tester manufactured by Orientec, measurement was performed at an initial sample length of 200 mm and a tensile speed of 200 mm / min, and the average value measured five times was taken as the measured value.

B. Measurement of apparent specific gravity of fiber and calculation of porosity The apparent specific gravity of fiber is based on the floatation method specified in JIS-L-1013: 1999 8.17.1 (published by Japan Standards Association, chemical fiber filament yarn test method). It measured and set it as the measured specific gravity value (Q). The following formula was used to calculate the porosity.
Porosity (%) = 100 (1-Q / R),
R = 100 / (S / V + (100−S) / Vp),
However, S: the amount of the thermoplastic polymer added (% by weight),
V: density of thermoplastic polymer (g / cm ³ )
Vp: density of polyester (g / cm ³ ; for example, for polyethylene terephthalate, 1.34 was used for undrawn yarn and 1.38 for drawn yarn)
R: Apparent specific gravity of polyester composite fiber without voids Confirmation of fiber diameter and dispersion diameter of island component Platinum-palladium deposition (deposition film pressure: 25 to 50 angstroms) is performed at an accelerating voltage of 10 kV using a scanning electron microscope ESEM-2700 manufactured by Nikon Corporation. After that, confirmation was performed at an arbitrary magnification between 2000 × and 20000 ×. The sample was prepared by cooling the fiber and the knife used as a sample in liquid nitrogen, and cutting in liquid nitrogen after cooling for 15 minutes.

D. Confirmation of discontinuity of island component (dispersion length in the fiber axis direction) 0.1 g of the obtained polyester composite fiber is impregnated with 200 ml of a 0.1N aqueous sodium hydroxide solution and stirred at 50 ° C. for 24 hours. The polyester was dissolved by hydrolysis. The suspended matter floating on the surface of the aqueous solution was regarded as a thermoplastic polymer as an island component, collected with a dropper, and observed at about 100 to 600 times with an optical microscope. Regarding the discontinuity, the ratio β / α of the diameter (α) of one dispersed island and the length (β) of the dispersion in the fiber axis direction in the cross section of the single fiber of the island component was determined and observed. The maximum possible ratio was used as an index of the discontinuity of the fiber. When the ratio was 200 or less, it was evaluated as ○, and when it exceeded 200, it was evaluated as x.

E. FIG. Evaluation of stretchability Regarding the stretchability in the stretching process, when 1 kg of undrawn yarn was stretched, the single yarn was broken and evaluated by the number of times the single yarn was wound around the stretching roller. × (impossible) when the yarn is wound, Δ (poor) when the single yarn is wound 10 to 19 times, ○ (good) when the single yarn is wound 4 to 9 times, and When the number of times the yarn was wound was 3 or less, it was evaluated as a double circle (excellent).

F. Measurement of glass transition temperature (Tgp or Tg) and melting point (Tm) Using a differential scanning calorimeter (DSC-2) manufactured by Perkin Elmer, a 10 mg sample was measured at a heating rate of 16 ° C./min. The definitions of Tm and Tg are as follows: After observing the endothermic peak temperature (Tm1) once measured at a heating rate of 16 ° C./min, hold at a temperature of Tm1 + 20 ° C. for 5 minutes, and then rapidly cool to room temperature, The quenching time and the holding time at room temperature were held together for 5 minutes), and the temperature was measured again under the heating condition of 16 ° C./min. The endothermic peak temperature observed as was defined as Tm.

G. FIG. Measurement of critical surface tension In a film made of polyester or thermoplastic polymer, pure water 72.8 dyne / cm, ethyl alcohol (special grade or higher) 22.3 dyne / cm, dioxane 33.6 dyne / cm, hexane 18.4 dyne / cm, 20 5% aqueous solution of 59.3 dyne / cm or 5 kinds of liquids selected from aqueous solutions and placed on a solid at 20 ° C., 40 to 80% humidity, and at room temperature under the condition of static liquid. When the droplet comes to rest, the angle between the solid surface where the droplet is in contact and the surface of the droplet where the droplet is in contact with the air layer is measured as the contact angle θ, and cos θ is determined for the surface tension of the liquid used. Plotting (Zisman plot), extrapolation is performed by extrapolating a point where the surface tension when completely wetted, that is, when cos θ = 1, is plotted. The interfacial surface tension was determined.

H. Measurement of weight average molecular weight High performance liquid chromatograph LC-6A manufactured by Shimadzu Corporation (differential refractometer RID-6A, pump LC-9A, column oven CTO-6A, column Shim-pack GPC-801C, -804C, -806C) , -8025C) using chloroform as a solvent (flow rate 1 mL / min, sample volume 200 μL (sample 0.5 w / w% dissolved in chloroform) at a column temperature of 40 ° C.). .

I. Measurement of Intrinsic Viscosity (IV) A sample was dissolved in an orthochlorophenol solution and measured at 25 ° C. using an Ostwald viscometer.
Reference Example To a low polymer obtained by a usual esterification reaction from 166 parts by weight of terephthalic acid and 75 parts by weight of ethylene glycol, 0.03 part by weight of a 85% aqueous solution of phosphoric acid as a coloring inhibitor, and trioxide as a polycondensation catalyst 0.06 parts by weight of antimony and 0.06 parts by weight of cobalt acetate tetrahydrate as a toning agent were added to carry out a polycondensation reaction to obtain a commonly used polyethylene terephthalate having an IV of 0.70.

  Using this polyester, melt spinning was performed at a spinning temperature of 290 ° C. using a spinneret having a hole diameter of 0.3 mm and 24 holes using a twin-screw extruder type melt spinning machine. The polyester multifilament fiber having a round cross section of 292 dtex-24 filaments was obtained. No yarn breakage occurred during spinning, and the spinning properties were excellent.

  When the obtained polyester fiber is drawn, the feeding speed of the feeding roller is set to 100 m / min. In order to perform the drawing between the first roller and the second roller, using a hot plate of 100 ° C. as a heat source, the draw ratio is set. Was stretched at 3.5 times, and the second roller was heat-treated at 150 ° C., and then cooled with a cold roller to a polyester Tg or less, and then wound up. No yarn breakage occurred during stretching, and the stretchability was excellent.

Example 1
When melt spinning is performed using a polyester obtained in the reference example using a twin-screw extruder-type melt spinning machine, a polymethylpentene (TPX (registered trademark) manufactured by Mitsui Chemicals, Inc.) is used as a thermoplastic polymer (excluding polyester). (Trademark), type RT18, and the same type of product (hereinafter abbreviated as PMP) unless otherwise specified. The melt spinning was carried out in the same manner as in the reference example by adding 8% by weight. And stretched at 3.5 times magnification. The fiber properties such as strength and specific gravity of the obtained fiber, as well as spinning property and stretchability were good. Table 1 shows the results of Example 1.

Comparative Example 1
When melt spinning is performed using a polyester obtained in the reference example using a twin-screw extruder-type melt spinning machine, a styrene maleimide copolymer (manufactured by Denki Kagaku Kogyo Co., Ltd.) as a thermoplastic polymer (excluding polyester) ( MSN (average molecular weight: about 110,000; hereinafter abbreviated as MSN) was added at 10% by weight, melt spinning was performed in the same manner as in the Reference Example, and stretching was performed at a magnification of 3.0 times in the same manner as in the Reference Example. Fiber properties such as strength or specific gravity of the obtained fiber were substantially the same as those shown in Example 1 of Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-154427). Regarding the yarn forming property or the stretching property, the yarn was frequently broken and the stretching ratio had to be lowered, which was inferior. In addition, the fiber strength was lower than that of the examples. Further, the obtained yarn and the drawn yarn obtained in Example 1 were visually compared, and a clear yellowing which was presumed to be derived from the addition of MSN was found. Table 1 shows the results of Comparative Example 1.

Comparative Example 2
When melt-spinning is performed using the polyester obtained in the reference example and the PMP of Example 1, the weight ratio of the core and the sheath is 8:92 with the polyester and the PMP as the core using the core-sheath composite spinning machine. , Composite spinning was performed, melt spinning was performed in the same manner as in the reference example, and stretching was performed at a magnification of 3.5 times in the same manner as in the reference example. Table 1 shows the results of the fiber properties such as the strength and specific gravity of the obtained fiber. Although the spinning property and the stretching property were good, the fiber was hardly lightened to the extent that the interface between the core and the sheath was separated.

Comparative Example 3
When melt-spinning is performed using the polyester obtained in the reference example and the PMP of Example 1, the weight fraction of the polyester and the PMP is determined to be PMP: polyester = 8: 92 using a normal pressure melter type melt spinning machine. The melted spinning is performed by filling the hopper with the dry-blended product in the chip state and kneading it in the polymer channel until it is discharged from the spinneret (mixer in the polymer channel). And the like were not provided), and the other conditions were the same as in Reference Example to obtain a fiber, which was then stretched at 3.5 times magnification in the same manner as in Reference Example. Table 1 shows the results of the fiber properties such as the strength and specific gravity of the obtained fiber. The spinnability and stretchability were very poor, and stretching could not be continuously performed for 5 minutes or more. In addition, as a result of observing the cross-sectional direction perpendicular to the fiber axis direction of the obtained drawn yarn using an electron microscope, the maximum dispersion diameter of PMP was more than 5 μm.

Example 2
When melt spinning using the polyester obtained in Reference Example with a twin-screw extruder-type melt spinning machine, 5% by weight of PMP was used as a thermoplastic polymer (excluding polyester), and ethylene terephthalate and polyethylene were used as compatibilizers. A copolymer with (ethylene oxide) glycol (hereinafter referred to as PET-PEG; poly (ethylene oxide) glycol component copolymerized at 10%) was added in an amount of 20% by weight based on the added amount of PMP, and the same as in Reference Example. , And the resulting fiber was stretched 3.7 times in the same manner as in Reference Example. The fiber properties such as strength and specific gravity were excellent, and the spinning properties and stretchability were also excellent. Table 1 shows the results of Example 2.

Comparative Example 4
In Example 2, melt spinning and stretching were performed in the same manner as in Example 2 except that PMP was not added. Table 1 shows the results of Comparative Example 2. When PMP was not added, although the spinning property and the stretchability were excellent, no void was observed and the weight was not reduced.

Example 3
In Example 2, 15% by weight of polypropylene (grade J108M, hereinafter abbreviated as PP) manufactured by Grand Polymer Co., Ltd. as a thermoplastic polymer (excluding polyester), butylene terephthalate and poly (tetramethylene oxide) glycol as compatibilizers (PBT-PTMG; 10% by weight of a poly (tetramethylene oxide) glycol component was copolymerized) in the same manner as in Example 2 except that the copolymer contained 20% by weight, based on the amount of PP added. The melt spinning and stretching were carried out by the methods described above. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 1 shows the results of Example 2.

Example 4
In Example 2, 15% by weight of a polyethylene manufactured by Mitsui Chemicals, Inc. (Hizex (registered trademark), grade 8200B, hereinafter abbreviated as PE) was used as a thermoplastic polymer (excluding polyester), and a compatibilizer manufactured by Meisei Chemical Industry was used. A method similar to that of Example 2 except that Alcox (registered trademark, type E-30), which is poly (ethylene oxide) having an average molecular weight of about 300,000, was contained in an amount of 33% by weight based on the PE content. Was used for melt spinning. Subsequently, stretching was performed at a magnification of 3.6 times in the same manner as in Reference Example. The obtained drawn yarn was excellent in fiber properties such as strength and specific gravity, and also excellent in drawability. Table 1 shows the results of Example 4.

Examples 5 to 8
In Example 2, melt spinning was performed in the same manner as in Example 2 except that the content of PMP was variously changed and the compatibilizer PET-PEG was contained in an amount of 40% by weight based on the content of PMP. . Then, in the same manner as in the Reference Example, stretching was performed at 3.7 times for Examples 5 and 7 and at 3.3 times for Examples 6 and 8, respectively.
As is clear from Table 2, Examples 7 and 8 were superior to Examples 5 and 6 in light weight and fiber properties. That is, by adjusting the content of the thermoplastic polymer (excluding polyester) to an appropriate amount, the obtained drawn yarn became more excellent in lightness or fiber properties.

Examples 9 to 12
In Example 3, melt spinning was performed in the same manner as in Example 3 except that the PP content was set to 10% by weight and the compatibilizing agent PBT-PTMG was variously changed with respect to the PP content. went. Subsequently, stretching was performed at 3.5 times magnification in the same manner as in Reference Example. As is clear from Table 2, Examples 11 and 12 were superior to Examples 9 and 10 in light weight and fiber properties. In other words, by adjusting the content of the compatibilizer to an appropriate amount, the obtained drawn yarn has better lightness or superior fiber properties.

Examples 13 and 14
In Example 2, as a thermoplastic polymer (excluding polyester), norbornene-based resin Arton (registered trademark, Example 13, type F5023) manufactured by JSR Corporation or Iupiace (registered trademark, Example manufactured by Mitsubishi Engineering-Plastics Corporation) manufactured by JSR Corporation. 14, type AH90) was carried out in the same manner as in Example 2 except that 10% by weight of each was melt-spun and stretched. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 3 shows the results of Examples 13 and 14. It was found that Arton or Ipiace had excellent compatibility with polyester even without a compatibilizer, had a high glass transition temperature, and was extremely excellent in lightness. No yellowing was observed.

Example 15
In Example 2, ZEONOR (registered trademark, type 1600R; hereinafter, ZEONOR) manufactured by Nippon Zeon Co., Ltd. was used as a thermoplastic polymer (excluding polyester) at 10% by weight, and PET-PEG as a compatibilizer was added to the amount of ZEONOR added. Melt spinning and stretching were carried out in the same manner as in Example 2 except that they were each contained at 40% by weight. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 3 shows the results of Example 15. It was found that the resulting fiber was very light in weight and did not show yellowing because Zeonoa had a high glass transition temperature.

Example 16
To a low polymer obtained by a usual esterification reaction from 166 parts by weight of terephthalic acid and 75 parts by weight of ethylene glycol, 0.03 parts by weight of a 85% aqueous solution of phosphoric acid as a coloring inhibitor and antimony trioxide as a polycondensation catalyst were added. A polycondensation reaction was carried out by adding 0.06 parts by weight of 0.06 parts by weight of cobalt acetate tetrahydrate as a toning agent to obtain a commonly used polyethylene terephthalate having an IV of 0.70.

  130 parts (6.7 mol parts) of dimethyl terephthalate, 114 parts (15 mol parts) of 1,3-propanediol, 0.24 part (0.014 mol part) of calcium acetate monohydrate, lithium acetate dihydrate 0.165 parts of trimethyl phosphate and 0.134 parts of titanium tetrabutoxide were added to a low polymer obtained by performing a transesterification reaction while charging 0.1 part (0.01 mol part) of a salt and distilling off methanol. In addition, a polycondensation reaction was performed while distilling off 1,3-propanediol to obtain a chip-shaped prepolymer. The obtained prepolymer was further subjected to solid phase polymerization at 220 ° C. under a nitrogen stream to obtain polytrimethylene terephthalate (hereinafter referred to as PPT) having IV1.12.

  When performing melt spinning and stretching using the obtained PPT in the same manner as in the Reference Example, 7 wt% of a PMP (type DX881, hereinafter abbreviated as PMP881) manufactured by Mitsui Chemicals as a thermoplastic polymer (excluding polyester). Nippon Steel Chemical's Estyrene (registered trademark, type MS200, hereinafter referred to as Estyrene) as a compatibilizer was added in an amount of 29% by weight based on the amount of PMP881, and the spinning temperature was 260 ° C. Melt spinning and stretching were carried out in the same manner as in Reference Example, except that the temperature was 80 ° C. and the stretching ratio was 4.5. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 3 shows the results of Example 16.

Example 17
In Example 16, 15% by weight of Mitsui Chemicals Apel (registered trademark, type 6015T; hereinafter, Apel) was used as a thermoplastic polymer (excluding polyester), and Hytrel (registered trademark, type 4057, manufactured by Toray Dupont) was used as a compatibilizer. , Hereinafter referred to as Hytrel), and melt spinning and stretching were carried out in the same manner as in Example 16 except that they were each added in an amount of 13% by weight based on the amount of the Apel. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 3 shows the results of Example 17.

Examples 18 and 19
After adding 0.005 parts by weight of tin octylate as a catalyst to 300 parts by weight of L-lactide and performing nitrogen substitution, the mixture was reacted at 170 ° C. to obtain polylactic acid (hereinafter, PLA) having a weight average molecular weight of 153,000. Obtained.

  When melt-spinning and drawing are performed using the obtained PLA in the same manner as in the Reference Example, 5% by weight (Example 18) or 10% by weight (Example 18) of PMP881 as a thermoplastic polymer (excluding polyester) is used. In Example 19, Alcox (registered trademark) used in Example 4 had a type R-150 having an average molecular weight of 100,000 as a compatibilizer in an amount of 30% by weight with respect to the added amount of PMP881. Melt spinning and stretching were performed in the same manner as in Reference Example, except that the spinning temperature was 240 ° C., the hot plate temperature during stretching was 90 ° C., and the stretching ratio was 4.5. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and also excellent in drawability. Table 3 shows the results of Examples 18 and 19.

  Uniform clothing such as white clothing, underwear, T-shirts, shirts, swimwear, women's clothing, men's clothing, etc., as well as being suitably used as lightweight clothing for infants or the elderly, sports clothing such as golf wear, gateball, Baseball, tennis, soccer, table tennis, volleyball, basketball, rugby, American football, hockey, athletics, triathlon, speed skating, ice hockey and other clothing and uniforms, or outdoor sports applications, such as shoes, bags, supporters, socks, and mountain climbing It can also be suitably used as clothing. Furthermore, as interior materials, car interior materials such as carpets and wall materials for automobiles, ships, aircraft, railways, etc., and other ropes, tents, curtains, and blinds, which are required to be lighter due to energy savings. Also, it is suitably used for materials requiring light-shielding properties such as packing materials used for various types of transportation.

Claims (10)

In a sea-island-like polyester composite fiber comprising a polyester and a thermoplastic polymer having no maleimide structure (excluding polyester), the following (1) to (3) are satisfied, and at least a part of a sea-island-like composite interface has a void, A polyester composite fiber, wherein the apparent specific gravity of the fiber is 1.2 or less, and the fiber strength is 2.5 cN / dtex or more.
(1) In the cross section of a single fiber fiber, polyester is a sea component, and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island components are present discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter of the island component in the single fiber cross section is 5 μm or less.   The polyester composite fiber according to claim 1, wherein the content of the island component is 1 to 30% by weight.   3. The polyester composite fiber according to claim 1, wherein the critical surface tension of the island component is 10 to 35 dyn / cm. Polyester composite fiber according to any one of claims 1 to 3, characterized in that the density of the island component is 1.0 g / cm ³ or less.   The polyester composite fiber according to any one of claims 1 to 4, wherein the glass transition temperature (Tg) of the island component is higher than the glass transition temperature (Tgp) of the polyester by 5C or more.   The polyester composite fiber according to any one of claims 1 to 5, wherein a glass transition temperature (Tg) of the island component is 130 ° C or more.   The polyester composite fiber according to any one of claims 1 to 6, wherein the melting point (Tm) of the island component is 150 ° C or higher.   The polyester composite fiber according to any one of claims 1 to 7, further comprising a compatibilizer.   The polyester composite fiber according to any one of claims 1 to 8, wherein the content of the compatibilizer is 10 to 200% by weight based on the island component.   A fiber product, wherein the polyester composite fiber according to any one of claims 1 to 9 is partially or entirely used.