JP4321232B2 - Lightweight polyester composite fiber - Google Patents

Description

  The present invention relates to a polyester composite fiber excellent in lightness. More specifically, the present invention relates to a polyester composite fiber excellent in fiber physical 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 that emphasized “lightness” has been It is attracting attention in terms of expansion, the popularity of outdoor sports and the expansion of lightweight or warm clothing, and the reduction of vehicle interior materials due to energy savings.

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

A monofilament having a low specific gravity composed of polyamide and a low specific gravity resin has been proposed (see Patent Document 2). The monofilament is intended to be used as a tie fishing line, and certainly floats on the water surface or between 50 and 100 cm below the water surface, but is inferior in Wash & Wear because it uses polyamide. When used as a clothing application or industrial material, there was a concern that the application would be limited .

A lightweight polyester fiber composed of a polyester resin and a styrene / maleimide resin having a molecular weight of 60 to 170,000 has been proposed (see Patent Document 3). As for the light-weight polyester, since the blending amount of styrene / maleimide resin is 3 to 30% by weight and it has fine cavities, it can surely be excellent in lightness, but the resin density is higher than 1.0.・ Since maleimide resin is used and the difference in critical surface tension between polyester and styrene / maleimide resin is less than 10 dyn / cm and the adhesiveness between the resins is good, the apparent specific gravity of the fiber is reduced, while the fiber Since excessive voids were developed in the inside, the strength was greatly lowered, and yellowing was feared due to the inclusion of maleimide. Therefore, the operability such as stretching and the physical properties of the yarn were not satisfactory.
JP 09-157960 (Claims) JP-A 63-296641 JP 2000-154427 A (claims, paragraph [0012])

  An object of the present invention is to provide a polyester composite fiber that solves the above-described problems of the prior art, is excellent in lightness, and is excellent in light-shielding properties and fiber properties such as strength.

  The present invention relates to a fiber having excellent lightness, and has been intensively studied to obtain a polyester composite fiber having excellent fiber properties such as strength, useful for various clothing materials or industrial materials. It has been found that a specific fiber structure and fiber properties containing the above-mentioned substances can eliminate the disadvantages of the prior art and can provide further merits.

That is, the present invention is a sea-island polyester composite fiber comprising a polyester and a thermoplastic polymer (excluding polyester) having no maleimide structure.
(1) In a fiber single yarn cross section, polyester is a sea component and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island component is discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter in the cross section of the fiber single yarn of the island component is 5 μm or less.
(4) The glass transition temperature (Tg) of the island component is 130 ° C. or higher.
And having a void in at least a part of the sea-island composite interface, the apparent specific gravity of the fiber is 1.2 or less, and the fiber strength is 4.0 cN / dtex or more, and is excellent in lightness A polyester composite fiber is provided.

The polyester composite fiber obtained by the present invention is preferable because it has a void in the fiber and an apparent specific gravity of 1.2 or less because it is very excellent in light weight and light shielding properties. In addition, since a thermoplastic polymer (excluding polyester) having no maleimide structure is used for the color of the fiber, there is no concern about the yellowishness (yellowing) of the fiber. For example, restrictions on the use when used for clothing There is no. Furthermore, in terms of fiber properties, since the fiber strength is 4.0 cN / dtex or more, uniform clothes such as lab coats, underwear, T-shirts, shirts, swimwear, women's clothing, men's clothing, etc. for infants or the elderly In addition to being suitably used as lightweight 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 It can also be suitably used for clothing and uniforms such as shoes or outdoor sports applications such as shoes, bags, supporters, socks, and climbing clothes. In addition, automotive interior materials such as carpets and wall materials for automobiles, ships, airplanes, railways, etc., as well as ropes, tents, curtains, blinds, etc., which are required to be lightened due to energy savings as industrial materials. Alternatively, it is also suitably used for materials that require light shielding properties such as packing materials used for various transportations.

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

  The polymer formed from the ester bond of the dicarboxylic acid compound and the diol compound may be copolymerized with other components within a range not impairing the gist of the present invention. Examples of the compound include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, anthracene dicarboxylic acid, phenanthrene dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylethanedicarboxylic acid, adipic acid, sebacic acid, 1 , 4-cyclohexanedicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium isophthalic acid, azelaic acid, dodecanedioic acid, hexahydroterephthalic acid, aromatic, aliphatic and alicyclic dicarboxylic acids And derivatives, adducts, structural isomers, and optical isomers such as alkyl, alkoxy, allyl, aryl, amino, imino, and halides, and one of these dicarboxylic acid compounds can be used alone. Alternatively, two or more kinds may be used in combination as long as the gist of the invention is not impaired.

  Examples of the copolymer component include diol compounds such as ethylene glycol, propylene glycol, butylene glycol, pentanediol, hexanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, hydroquinone, resorcin, dihydroxybiphenyl, naphthalenediol, anthracene. Aromatic, aliphatic and alicyclic diol compounds such as diol, phenanthrenediol, 2,2-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl ether, bisphenol S, and their alkyl, alkoxy, allyl, Derivatives, adducts, structural isomers, and optical isomers such as aryl, amino, imino, and halide can be listed. 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 copolymer component include a compound having a hydroxyl group and a carboxylic acid in one compound, that is, a hydroxycarboxylic acid. Examples of the hydroxycarboxylic acid include lactic acid, 3-hydroxypropionate, and 3-hydroxybutyrate. Aromatic, aliphatic and alicyclic diol compounds such as acrylate, 3-hydroxybutyrate valerate, hydroxybenzoic acid, hydroxynaphthoic acid, hydroxyanthracenecarboxylic acid, hydroxyphenanthrenecarboxylic acid, (hydroxyphenyl) vinylcarboxylic acid, and their Derivatives, adducts, structural isomers and optical isomers such as alkyl, alkoxy, allyl, aryl, amino, imino, and halide can be mentioned, and 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.

  The polyester in the present invention may be a polymer in which one compound such as aromatic, aliphatic, alicyclic, etc. is mainly composed of a hydroxycarboxylic acid compound having both a carboxylic acid and a hydroxyl group, Although not limited, for example, polymers related to these include polylactic acid, poly (3-hydroxypropionate), poly (3-hydroxybutyrate), poly (3-hydroxybutyrate valerate), In addition, poly (hydroxycarboxylic acid) such as aromatic, aliphatic, alicyclic dicarboxylic acid, or aromatic can be used as long as they do not impair the gist of the present invention. Aliphatic, aliphatic and alicyclic diol components may be used, or multiple types of hydroxycarboxylic acids may be copolymerized. Even though it may.

  Of these polyesters, preferred are polyesters whose main repeating unit is ethylene terephthalate, propylene terephthalate, butylene terephthalate, or lactic acid, and more preferred are polyesters whose main repeating unit is ethylene terephthalate.

  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, if it is polyethylene terephthalate, IV is preferably 0.4 to 1.5, and more preferably 0.5 to 1.3. Moreover, if it is a polypropylene terephthalate, it is preferable that it is IV0.7-2.0, and it is more preferable that it is 0.8-1.8. Or if it is polybutylene terephthalate, it is preferable that it is IV0.6-1.5, and it is more preferable that it is 0.7-1.4. Polyesters used in the present invention include poly (hydroxycarboxylic acids) represented by polylactic acid that are not evaluated in IV, and these are described in terms of weight average molecular weight (hereinafter sometimes simply referred to as average molecular weight). For example, in the case of polylactic acid, those having an average molecular weight of 50,000 to 500,000 are usually used, preferably 100,000 to 300,000, and an average of 150,000 to 250,000 in view of processability and spinnability Molecular weight polylactic acid is more preferably used.

  Since the polyester content in the polyester composite fiber of the present invention is a main component, it is necessary that the content is 50% by weight or more, but the content of 50% by weight or more is not particularly limited and is arbitrary. The content of can be taken. In particular, since it is preferable that the fiber properties have high strength, the polyester content in the composite fiber is preferably 70% by weight or more, more preferably 80% by weight or more, and even more preferably 85% by weight or more. .

  The polyester composite fiber of the present invention has a thermoplastic polymer having no maleimide structure (excluding polyester, which may be simply referred to as a thermoplastic polymer hereinafter) as an island component. 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 in the molecular chain size order of the polymer, and the average size of islands formed by the thermoplastic polymer in the polyester (the shortest of the islands). (Corresponding to the length corresponding to the diameter) refers to that having a size of at least 10 nm. If the polyester and thermoplastic polymer are compatible, that is, if the average size of the islands formed is 10 nm or less, the islands formed by the thermoplastic polymer will be very small in size and will not have voids or will be lightweight The voids necessary for producing excellent fibers are not sufficiently developed, and as a result, the composite fibers are inferior in lightness, 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 a wide variety of thermoplastic polymers should be used. Can do. For example, polyamide polymer, polyolefin polymer and other vinyl polymers, fluorine polymer, silicone polymer, elastomer, polycarbonate polymer, polyimide polymer formed by cyclization polycondensation of carboxylic acid anhydride and diamine, dicarboxylic acid Polybenzimidazole polymers formed by the reaction of esters and diamines, polysulfone polymers, aliphatic polyether polymers, aromatic polyether polymers, polyphenylene sulfide polymers, polyetheretherketone polymers, polymers Examples thereof 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, polyolefins and other vinyl polymers synthesized by a mechanism in which a monomer having a vinyl group such as radical polymerization, anionic polymerization, or cationic polymerization is formed by addition polymerization reaction or ring-opening polymerization reaction. In the case of polyolefins, homopolymers, copolymers, and derivatives of polyethylene, polypropylene, polybutylene, and polymethylpentene can be used as polyolefins, and polystyrene, polyacrylic acid, polymethacrylic acid can be used as other vinyl polymers. , Polymethyl methacrylate, polyacrylonitrile, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene chloride, poly (vinylidene 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-based polymers, first, as a polyolefin mainly composed of olefins, for example, ethylene, propylene, butene, methylbutene, methylpentene, ethylpentene, hexene, ethylhexene, octene, decene, tetradecene, octadecene as monomers In addition to the polyolefin used as the polymer, a polyolefin polymer having a cyclic structure represented by the following chemical formula 1, chemical formula 2, or chemical formula 3, for example, synthesized by ring-opening polymerization or addition polymerization of an alicyclic monomer can be given.

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 polyolefins having a cyclic structure, such as Arton (registered trademark) manufactured by JSR Corporation, Zeonoa (registered trademark) manufactured by Nippon Zeon Co., Ltd., and the like. is not.

  These polyolefin polymers may be homopolymers using one kind of monomer alone, or may be a copolymer using two or more kinds, and further copolymerize olefins with other vinyl compounds. It may be a copolymer. Specific examples of the copolymer component include vinyl esters of saturated aliphatic carboxylic acids having 2 to 6 carbon atoms, acrylic acid esters and methacrylic acid esters derived from alcohols having 1 to 20 carbon atoms, Unsaturated carboxylic acids such as fumaric acid, maleic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, nadic acid, acid halides, amides, imides, acid anhydrides and esters of the unsaturated carboxylic acids, Examples thereof include vinyl compounds such as styrene or styrene derivatives, acrylonitrile or acrylonitrile derivatives, vinyloxyalkyl derivatives (alcohol type or carboxylic acid type), or vinyl compounds having an alicyclic structure. In particular, examples of the polyolefin-based polymer having the alicyclic structure as a copolymerization component include, for example, Apel (registered trademark) manufactured by Mitsui Chemicals, Inc. Of course, the copolymerized polyolefin-based polymer having the alicyclic structure is this. It is not limited to.

  Of the polyolefin polymers exemplified as preferred among these thermoplastic polymers (excluding polyester), polyolefins having propylene and / or methylpentene as the main repeating unit in that the void formation of the formed fiber is high. A polymer, a polyolefin polymer having a cyclic structure, or a copolymerized polyolefin polymer having an alicyclic structure is preferable.

  The thermoplastic polymer (excluding polyester) of the present invention includes a polyether polymer in addition to the polyolefin polymer, and among them, an aromatic polyether polymer typified by polyphenylene ether is preferable. The polyphenylene ether may be a homopolymer mainly composed of phenylene oxide, or may be a copolymer obtained by copolymerizing the second component, and may be added within the range not impairing the gist of the invention. It may be a modified polyphenylene ether alloyed with a contained component, that is, a polystyrene polymer, a polyamide polymer, a polyester polymer, a polyolefin polymer, or the like as a second component. Examples of the modified polyphenylene ether include Iupiace (registered trademark) and Remalloy (registered trademark) manufactured by Mitsubishi Engineering Plastics Co., Ltd., Noryl (registered trademark) manufactured by GE Plastics Co., Ltd., and Asahi Kasei Co., Ltd. Zylon (registered trademark), Art Rex (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., Artley (registered trademark), and the like. Needless to say, aromatic polyether polymers mentioned as preferred thermoplastic polymers are these. It is not limited to.

  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 is the demerit that the resulting fiber yellows, but the gap between the polyester and the thermoplastic polymer is too high. It is not preferable because not only the lightness is insufficient and sufficient lightness is not exhibited, but also the light shielding property of the fiber obtained by inferior void formation is lowered. Examples of the thermoplastic polymer having a maleimide structure include styrene maleimide polymer (type: MS-NA, etc.) manufactured by Electrochemical Co., Ltd.

  As the thermoplastic polymer (excluding polyester) having no maleimide structure in the present invention, one kind of the aforementioned 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 larger than 1.0 g / cm ³ , for example, in order to make the apparent specific gravity of the fiber 1.2 or less, for example, it may be present in a larger amount when voids are formed. . However, if there are too many voids, the strength will be reduced and the yarn will break easily.

The thermoplastic polymer is suitable as the density is small, 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, as the one having a density of 1.0 g / cm ³ or less, for example, the above-mentioned polyolefin is exemplified, and ethylene, propylene, butene, methylbutene, methylpentene, ethylpentene, hexene, Ethylhexene, octene, decene, tetradecene, octadecene, etc. can be used as the monomer. These polyolefins may be a homopolymer using one kind of monomer alone, or may be a copolymer using a plurality of kinds. Moreover, the copolymer which copolymerized these olefins and another ethylenically unsaturated compound may be sufficient, Specifically, the vinyl ester of the saturated aliphatic carboxylic acid which has 2-6 carbon atoms, Acrylic acid esters and methacrylic acid esters derived from alcohols having 1 to 20 carbon atoms, unsaturated carboxylic acids such as fumaric acid, maleic acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, nadic acid Acids or acid halides, amides, imides, acid anhydrides and esters of the unsaturated carboxylic acids, styrene or styrene derivatives, acrylonitrile or acrylonitrile derivatives, vinyloxyalkyl alcohols or derivatives thereof, vinyloxyalkyl carboxylic acids or their Ethi such as derivatives Emissions unsaturated compounds. One of these thermoplastic polymers other than polyester may be used alone, or a plurality of them may be used in combination as long as the gist of the invention is not impaired. Among these thermoplastic polymers other than polyester, a homopolymer or copolymer of polyolefin in which ethylene and / or propylene and / or butylene and / or methylpentene account for 80 mol% or more is preferable, and propylene and / or methylpentene. Is more preferably a homopolymer or a copolymer occupying 80 mol% or more. In such a copolymer in which propylene and / or methylpentene account for 80 mol% or more, the copolymerization is not particularly limited, but, for example, an aliphatic hydrocarbon or fatty acid having 5 or more carbon atoms. Examples thereof include vinyl compounds having cyclic hydrocarbons, aromatic hydrocarbons, or derivatives thereof in the side chain.

  Further, 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 2000 from the viewpoint of excellent kneadability with polyester, form retention in fibers, and rigidity. It is preferably -10000000, more preferably 5000 to 5000000, and even more preferably 10000 to 1000000.

  The thermoplastic polymer (excluding polyester) of the present invention is preferably 1 to 30% by weight in terms of excellent lightness and excellent yarn physical 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 (excluding polyester) of the present invention is a thermoplastic polymer in terms of facilitating the formation of voids at the composite interface of the polyester sea-island composite fiber of the present invention, resulting in a smaller specific gravity and excellent lightness. The critical surface tension of the polymer is preferably 10 to 35 dyn / cm, more preferably 12 to 30 dyn / cm, and even more preferably 15 to 25 dyn / cm. The thermoplastic polymer satisfying the critical surface tension range is a homopolymer in which propylene and / or methylpentene account for 80 mol% or more of the polyolefins comprising the above-mentioned olefin monomers or other ethylenically unsaturated compounds. 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 as described above, it is preferable that the peelability from the thermoplastic polymer is higher when voids are formed, so the critical surface tension of the polyester is It is preferably 35 dyn / cm or more, and more preferably 38 dyn / cm or more. For example, polyester polymers such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate 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. In addition, copolymer components that can increase the critical surface tension, for example, a copolymer polyester obtained by copolymerizing a component having a polar group such as sulfoisophthalate or a phosphate, co-polymerize these components having a polar group. Compared to unpolymerized polyester, it is preferable because it can have a larger critical surface tension. The critical surface tension is described in G. It is defined by the method.

  The thermoplastic polymer (excluding polyester) of the present invention preferably has a melting point (Tm) of 150 ° C. or higher in terms of good heat resistance of the polyester composite fiber and excellent lightness at high temperatures. More preferably, the temperature is 180 ° C. or higher. Here, the melting point (Tm) means F. It is defined by the method. As the thermoplastic polymer satisfying the Tm range, a homopolymer or copolymer in which propylene and / or methylpentene account for 80 mol% or more of the polyolefins composed of the above-mentioned olefin monomers or other ethylenically unsaturated compounds. 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 occupies 80 mol% or more is also preferable in that it does not easily yellow.

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

The thermoplastic polymer (excluding polyester) that forms an island component with the polyester composite fiber of the present invention is a glass of thermoplastic polymer in that voids are easily generated when the polyester composite fiber is stretched, and the resulting fiber is lightweight. The transition temperature (Tg) is preferably 5 ° C. or more higher than the glass transition temperature (Tgp) of the polyester. Here, the glass transition temperature (Tg) is F. of Examples described later. It is defined by the method. The Tg is more preferably at least 10 ° C higher than Tgp, even more preferably at least 30 ° C, and particularly preferably at least 50 ° C. When the Tg of the thermoplastic polymer is higher than that of the polyester by 5 ° C. or more, not only the interfacial peeling between the polyester and the thermoplastic polymer is manifested in the void formation during stretching, but also the splitting and peeling of the thermoplastic polymer itself. Further, in melt spinning, a thermoplastic polymer is solidified at a temperature higher than that of polyester and forms an island structure that is advantageous for void formation. And the glass transition temperature of the thermoplastic polymer forming the island component (Tg) of, in that they more suitable for void generation is 130 ° C. or higher. The glass transition temperature Tgp of each polyester is as follows. In this method, polyethylene terephthalate is 72 ° C., polypropylene terephthalate is 47 ° C., polybutylene terephthalate is 24 ° C., polylactic acid is 58 ° C., and polycyclohexanedimethanol terephthalate is 87. In the case of polyethylene naphthalate, it is observed at 122 ° C., respectively.

  The thermoplastic polymer of the present invention (excluding polyester) is not particularly limited, but within the range that does not impair the gist of the invention, addition of a flame retardant, a lubricant, an antioxidant, a crystal nucleating agent, a terminal group sealing agent, etc. A small amount of an agent may be contained.

  The method for adding the island component to the sea component in the present invention is not particularly limited. For example, (A) In a normal polyester polymerization reaction, it is added at an arbitrary stage before the polyester polymerization reaction stops. Method, (B) a method in which a thermoplastic polymer other than polyester is added at the time of spinning of the polyester, and melt kneading is performed under normal pressure or reduced pressure by a kneader such as an extruder or a static mixer, and (C) other than polyester in a normal polyester polymerization reaction. A method in which a thermoplastic polymer is added at a high concentration, and a polyester not added with a thermoplastic polymer other than polyester is simultaneously added and diluted by a kneader such as an extruder or a static mixer, and melt-kneaded at normal pressure or reduced pressure. D) Use a thermoplastic polymer other than polyester. Polyester which is added to ester and melted and kneaded at high concentration under normal pressure or reduced pressure using a kneader such as an extruder or static mixer, and then added with a thermoplastic polymer other than polyester by a kneader such as extruder or static mixer when spinning the polyester Are simultaneously added and diluted, melt-kneaded under normal pressure or reduced pressure, (E) a method of adding and kneading a thermoplastic polymer other than polyester to the polyester in a solution state, and subjecting to spinning, (F) spinning of polyester The method of discharging a melt or solution of a thermoplastic polymer other than polyester from a nozzle-like tube or the like at any stage prior to discharge in the polyester is preferable, and preferably the above-mentioned (B), ( Method C) or (D) is adopted

  The polyester conjugate fiber of the present invention may have poor compatibility between the polyester and the thermoplastic polymer (excluding polyester). Therefore, it is preferable to contain a compatibilizing agent. The compatibilizing agent in the present invention is a compound that controls the dispersion diameter of the island component by changing the interaction at the composite interface to increase the compatibility of the island component when the island component is contained in the sea component. As the compatibilizing agent, a wide variety of compounds such as a low molecular compound or a high molecular compound can be adopted. For example, as the low molecular compound, sodium dodecylbenzenesulfonate, sodium alkylsulfonate, glycerin monostearate, Anionic or cationic surfactants such as tetrabutylphosphonium paraaminobenzenesulfonate and amphoteric surfactants, poly (alkylene oxide) glycols such as polyethylene glycol, methoxypolyethylene glycol, polytetramethylene glycol, and polypropylene glycol, and ethylene oxide / propylene Nonionic surfactants, such as an oxide copolymer, are mentioned.

  Further, as the polymer compound mentioned as the compatibilizing agent, a polymer compound having high compatibility or affinity for each of polyester and thermoplastic polymers other than polyester may be used. For example, polystyrene polymer, polymer 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- Propylene) copolymer, poly (vinyl acetate-styrene) copolymer such as vinyl polymers or copolymers, ionomers, polysaccharides having improved heat resistance and melt plasticity by chemically modifying the side chain moiety, polyalkylene polymers Copolymers of alkylene oxides and vinyl derivatives, such as side or poly (alkylene oxide-ethylene) copolymers, 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) glycol, copolymers of alkylene terephthalate and polyalkylene diol, and the like. Among them, considering the fact that the effect as a compatibilizing agent is great and the yarn physical properties when the fiber of the present invention is formed are good, polystyrene polymer, polyacrylate polymer, polymethacrylate polymer, alkylene terephthalate and Preferred are copolymers of alkylene glycol, copolymers of alkylene terephthalate and poly (alkylene oxide) glycol, poly (alkylene oxide) glycol, copolymers of alkylene terephthalate and polyalkylene diol, or derivatives of these polymers.

  Specific examples of alkylene terephthalate and polyalkylene diol, a copolymer of alkylene terephthalate and alkylene glycol, a copolymer of alkylene terephthalate and poly (alkylene oxide) glycol, or poly (alkylene oxide) glycol or a derivative thereof, which are considered preferable, are described below. Needless to say, the compatibilizer in the present invention is not limited thereto.

  As a copolymer of alkylene terephthalate and polyalkylene diol, an alkylene terephthalate selected from ethylene terephthalate, propylene terephthalate, butylene terephthalate, pentamethylene terephthalate, hexamethylene terephthalate, and the like, polyalkylene diol selected from polyethylene diol, polybutylene diol, etc. One type of each of alkylene terephthalate and alkylene glycol may be used, or a plurality of types may be used. Specific examples include poly (ethylene terephthalate-polyethylene diol) copolymer, poly (propylene terephthalate-polyethylene diol) copolymer, poly (butylene terephthalate-polybutylene diol) copolymer, and the like. .

  As the copolymer of alkylene terephthalate and alkylene glycol, alkylene terephthalate selected from ethylene terephthalate, propylene terephthalate, butylene terephthalate, pentamethylene terephthalate, hexamethylene terephthalate, ethylene glycol, propylene glycol, butylene glycol (or tetramethylene glycol), penta It is a copolymer comprising an alkylene glycol selected from methylene glycol and hexamethylene glycol, and one or more of each of alkylene terephthalate and alkylene glycol may be used. Specific examples include, but are not limited to, polyethylene terephthalate-butylene glycol copolymer, polypropylene terephthalate-ethylene glycol copolymer, polybutylene terephthalate-tetramethylene glycol copolymer, and the like.

  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, and the like, 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 composed of a copolymer of ethylene oxide and propylene oxide, and alkylene terephthalate And 1 each of poly (alkylene oxide) glycol 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 so on.

The main chemical structure of poly (alkylene oxide) glycol or its derivative is a group (or group) of aliphatic, aromatic, alicyclic, etc. carbon having a main chain and oxygen atoms bonded alternately. Any 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)
Examples of satisfying the formula (1) include poly (ethylene oxide) glycol (a = 2), poly (propylene oxide) glycol (a = 3), poly (tetramethylene oxide) glycol (a = 4), and the like. Of poly (alkylene oxide) glycols.

The poly (alkylene oxide) glycol may be 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.) For example, copolymers of different alkylene oxides.

  Furthermore, as the poly (alkylene oxide) glycol, the polyalkylene oxide represented by the above general formula (1) or (2) may be used alone or in a range not impairing the gist of the invention. You may use what combined 2 or more types in the range which does not impair the main point of invention.

  One of these compatibilizers which are low molecular weight compounds or high molecular weight compounds may be used alone, or two or more may be used in combination as long as the gist of the invention is not impaired. The compatibilizers include, but are not limited to, polyethylene oxide Alcox (registered trademark) manufactured by Meisei Chemical Industry, Hytrel (registered trademark) manufactured by Toray DuPont, and polystyrene-based styrene resin manufactured by Nippon Steel Chemical. (Registered trademark) and the like can be mentioned as preferable ones.

  The content of the compatibilizing agent in the polyester composite fiber of the present invention is such that the compatibilization is more effectively expressed and the fiber physical properties of the resulting 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 for adding the compatibilizer to the polyester in the present invention is not particularly limited. For example, (A) In a normal polyester polymerization reaction, it is added at any stage before the polyester polymerization reaction stops. Method, (B) a method in which a compatibilizing agent is added at the time of spinning of the polyester, and melt kneading is carried out by a kneader such as an extruder or a static mixer under normal pressure or reduced pressure. (C) a high concentration of the compatibilizing agent in a normal polyester polymerization reaction. Add the polyester without adding the compatibilizer with a kneader such as an extruder or static mixer and dilute it at the same time, then melt and knead it under normal pressure or reduced pressure. (D) Add the compatibilizer to the polyester Normal pressure or reduced by a kneader such as an extruder or static mixer A method of melt-kneading under normal pressure or reduced pressure after melt-kneading at a high concentration at the bottom and then simultaneously adding and diluting polyester without adding a compatibilizer by a kneader such as an extruder or static mixer during spinning of the polyester, (E) A method in which a compatibilizing agent is added to a polyester in a solution state, kneaded and used for spinning, and the like. Although not particularly limited, preferably the above-mentioned (A), (B) or (C) The method is adopted.

  The polyester composite fiber in the present invention needs to have a fiber shape. The fiber refers to one having an elongated shape and a ratio of the length to the apparent diameter of at least 20, for example, a long fiber (filament) or a short fiber (staple) made by manufacturing a conventional synthetic fiber. ) 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 that the fiber properties are excellent or the processability is further improved in forming the fabric. Is more preferably 1000 μm or less, and even more preferably 200 μm or less. In addition, 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, but a round shape is preferable in that the fiber has stable physical properties, or From the viewpoint of improving lightness, a multi-leaf type or a hollow type is preferable. Although not particularly limited, as a hollow mold, hollow fibers can be obtained by forming a spinning discharge hole into a discharge shape that can be formed, for example, as a C shape or a well shape, or by using a reagent. Examples include a method in which a core-sheath fiber is obtained using a component that can be eluted as a core component, and then a hollow fiber is obtained by eluting the core component.

The polyester conjugate fiber in the present invention is
(1) In a fiber single yarn cross section, polyester is a sea component and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island component is discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter in the cross section of the fiber single yarn of the island component is 5 μm or less.
(4) The glass transition temperature (Tg) of the island component is 130 ° C. or higher.
It is a polyester composite fiber that satisfies the following conditions. In the polyester composite fiber of the present invention, in the fiber single yarn cross section, 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. Therefore, 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 weight is extremely low. Excellent polyester composite fiber. However, when the cross section of the single fiber is one island component and / or the island component is continuous (not dispersed) in the fiber axis direction, the cross-sectional shape of the resulting polyester composite fiber is the core-sheath type And / or a sea-island type composite fiber in which island components are continuously present in a lotus root shape, and the area of the composite interface becomes very small and voids are not generated or reduced, resulting in poor lightness. The presence of island components discontinuously dispersed in the fiber axis direction can be confirmed by observing the cross section in the fiber axis direction by a measurement method, etc., which will be described later. The ratio β / α of the diameter (α) of one dispersed island in the cross section of the fiber single yarn of the island component to the length (β) in the fiber axis direction of the dispersion is 1000 or less. It is defined that “a thermoplastic polymer other than polyester is discontinuously dispersed in the fiber axis direction”, and β / α is preferably 100 or less, and more preferably 10 or less.

  Further, when the maximum dispersion diameter in the cross section of the fiber single yarn of the island component in 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 voids existing in at least a part of the composite interface In addition to the fact that the polyester composite fiber is extremely superior in terms of weight and weight, the generated voids are not excessively large and are unlikely to be fiber defects, so the fiber strength of the polyester composite fiber is also reduced. It will be very good without. However, when the maximum dispersion diameter in the cross section of the single fiber of the island component is larger than 5 μm, the area of the composite interface is reduced, the number of voids is very small and the weight is inferior, and the fiber strength is low. The fiber properties become very inferior, or in the manufacturing stage, it is inferior in the spinning property and stretchability. In the present invention, the maximum dispersion diameter of the island component in the fiber single yarn cross section is preferably smaller than the fiber single yarn diameter, preferably 3 μm or less, more preferably 1 μm or less, and even more preferably 0.8 μm or less. is there. 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 more The value of [single fiber diameter / maximum dispersion diameter of island component] is preferably 2 or more, more preferably 4 or more, and more preferably 10 or more. Even more preferred.

  As described above, the polyester conjugate fiber of the present invention needs to have voids in at least a part of the conjugate interface. Having the voids makes the polyester composite fiber of the present invention extremely excellent in lightness and is preferable, and since the voids are fine, it is unlikely to be a defect in the fiber structure, and the fiber strength is also excellent. Further, although there is no particular limitation on the void ratio indicating the volume ratio of the voids in the fiber, the apparent specific gravity of the fiber of the present invention is 1.2 or less, and it is more lightweight. From the viewpoint, it is preferable to have a porosity of 15% or more, and more preferable to have a porosity of 25% or more. The method for developing the voids is not particularly limited, and may be any method that can apply stress to develop the voids. For example, the undrawn yarn obtained by winding the yarn into a yarn Examples include a method of stretching at a magnification, a method of continuously stretching at a high magnification without winding up an undrawn yarn during spinning, a method of drawing at a high speed in spinning, or heating the obtained yarn or applying specific light. Irradiation includes a method of shrinking a thermoplastic polymer other than polyester in the polyester composite fiber, and although any method can be employed, the process is simple and the control of void formation is easy. A method of drawing an undrawn yarn obtained by winding on a spinning at a high magnification or a method of drawing continuously at a high magnification without winding up the undrawn yarn at the time of spinning is preferred. There.

  The polyester conjugate fiber of the present invention is not particularly limited, but is excellent in form stability and weather resistance, or adopts shrinkage characteristics in various usage environments in various materials for clothing or industry. The shrinkage rate when held 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 excellent shape stability, in view of 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. Further, the lower limit of the elongation of the fiber is not particularly limited, but is preferably 3% or more, more preferably 5% or more as achievable in production.

  The means for producing the polyester conjugate fiber of the present invention is not particularly limited, and a commonly used synthetic fiber production method can be adopted, for example, a resin melt or solution is simultaneously discharged from a nozzle, Although a wide variety of manufacturing methods such as melt spinning, wet spinning, dry spinning, and dry and wet spinning can be adopted, the process is very simple, excellent in productivity, 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 and wet spinning method, the fiber is not particularly limited, but once used in the present invention as necessary. After cooling to a glass transition temperature of polyester or less, preferably after taking up at a take-up speed of 100 to 10000 m / min, after being taken up or once taken up, it is preferably drawn at a draw ratio of 1.5 times or more. It is preferable that the film is stretched false twisted. In the drawing process, the polyester composite fiber is heated without being heated or heated with a pin-like product, a roller-like product, a plate-like product, a liquid such as hot water, or a non-contact type heater, and the like. Or it extends | stretches by several steps. In the stretch false twisting process, the polyester composite fiber is not heated after being stretched, or a non-contact type liquid such as a pin-like product, a roller-like product, a plate-like product, hot water, or the like that has been heated. After heating with a heater or the like, false twisting is performed with a disk or belt. The stretched or stretched false twisted polyester conjugate fiber is preferably wound as it is or after being heat set, although not particularly limited.

  In the polyester composite fiber of the present invention, a polymer other than polyester and a thermoplastic polymer (excluding polyester) can be blended within a range not impeding the effects of the present invention.

  The apparent specific gravity of the polyester composite fiber in the present invention is required to be 1.2 or less. When used as clothing for infants or elderly people, as well as when used as sports uniforms or outdoor clothing, the apparent specific gravity of the fiber is small, and it is very favorable characteristics that it is excellent in lightness with the same bulk (volume). Become. Furthermore, when considering the case of using as an industrial material, the weight is reduced when the equivalent strength is assumed, so it is very preferable for transportation. Conversely, when the weight is equivalent, the strength is higher. 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. Further, although the lower limit of the apparent specific gravity is not particularly limited, it is possible to achieve a fiber having an apparent specific gravity of usually 0.30 or more, preferably 0.35 or more as what can be produced.

The fiber strength of the polyester composite fiber in the present invention is required to be 4.0 cN / dtex or more. Of course, when used as clothing for infants or elderly people, as well as when used as sports uniforms or outdoor clothing, and when used as an industrial material, it should be a durable material. There is. Further, even when the workability of fibers or fabrics is taken into consideration, the yarn properties are required to have high strength. The strength of the polyester composite fiber is more preferably 4.5 cN / dtex or more, and still more preferably 4.7 cN / dtex or more.

  The polyester composite fiber of the present invention may retain 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 synergistic effect of the voids formed in the fiber and the compatibilizer used. For example, with respect to hygroscopicity, when the polyester composite fiber of the present invention is used in part or all as a cloth for clothing, a more comfortable wearing feeling can be obtained without being sticky when worn. The value of the hygroscopic index (ΔMR), which is an index of hygroscopicity, is preferably 0.10% or more, and more preferably 0.20% or more. Specifically, ΔMR 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 to the outside air when the clothes are worn. The temperature in the clothes when performing light to moderate work or exercise is 30 ° C, 90% This is represented by RH, and the outside air temperature is represented by 20 ° C. and 65% RH, and the difference between the two is taken. In the present invention, this ΔMR is used as an index of the hygroscopic evaluation, and the larger ΔMR corresponds to the higher moisture absorption / release capability and the better comfort when worn.

  The polyester composite fiber of the present invention is very useful as a fiber itself because it is excellent in lightness, and the fiber can be used as it is. However, since it is excellent in lightness, the polyester composite fiber of the present invention is used as a part of a fabric. Or you may use for all. Fabrics in which the polyester conjugate fiber of the present invention is used in part or in whole include fabrics such as taffeta, twill, satin, desine, palace, and georgette, flat knitting, rubber knitting, double knitting, single tricot knitting, half Shows knitted fabrics such as tricot, chemical bond method, thermal bond method, needle punch method, water jet punch (spun lace) method, stitch bond method, felt method, etc. There are no particular restrictions on the form of fibers such as yarn. Of course, if it is a woven or knitted fabric, it may be processed by conventional scouring, dyeing, heat setting, etc., or if it is a non-woven fabric, it may be a glazing press, embossing press, compact processing, flexible processing, heat setting, etc. Chemical processing such as physical processing, bonding processing, laminating processing, coating processing, antifouling processing, water repellent processing, antistatic processing, flameproofing processing, insectproof processing, sanitary processing, foam resin processing, etc. In addition, application processing such as microwave application, ultrasonic application, far-infrared application, ultraviolet application, and low-temperature plasma application may be performed, and the final form may be sewn as clothing.

  In addition, the fabric in which the polyester composite fiber of the present invention is used in part is a synthetic fiber, semi-synthetic fiber, natural fiber, etc. different from the polyester composite fiber of the present invention, such as cellulose fiber, wool, silk, A mixed fabric characterized in that at least one type of fiber selected from stretch fibers and acetate fibers is used. Specific examples of cellulose fibers include natural fibers such as cotton and hemp, steel ammonia rayon, rayon, polynosic, etc., and the content of polyester composite fibers mixed with these cellulose fibers is not particularly limited. However, it is preferably 25 to 75% in order to make use of the texture, moisture absorption, water absorption and antistatic properties of the cellulose fiber and to take advantage of the light weight of the polyester composite fiber of the present invention. In addition, existing wool and silk used for blended fabrics can be used as they are. The content of these wool or polyester composite fibers mixed with silk is the texture, warmth, bulkiness of the wool, In order to make use of the texture and squeak noise, and to make use of the lightweight property of the polyester composite fiber of the present invention, 25 to 75% is preferable. In addition, the stretch fiber used for the mixed fabric is not particularly limited, and is a polyester fiber typified by dry-spun or melt-spun polyurethane fiber, polybutylene terephthalate fiber, or polytetramethylene glycol copolymer polybutylene terephthalate fiber. Examples thereof include elastic yarns, and in a mixed fabric using stretch fibers, the polyester composite fiber content is preferably about 60 to 98%. When the content of the polyester composite fiber exceeds 70%, the stretchability can be suppressed, so that it can be used for outer and casual wear applications. If it is less than 70%, it can be used for innerwear, foundation, swimwear, etc. due to its stretchability. Moreover, the acetate fiber used for 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 texture, sharpness, and gloss of the acetate fiber and to make use of the light weight of the polyester composite fiber of the present invention.

  In these various blended fabrics, the form of the polyester composite fiber of the present invention and the blending method are not particularly limited, and known methods can be used. For example, mixed methods include woven fabrics such as union woven fabrics and reversible fabrics used for warp or weft yarns, knitted fabrics such as tricot and russell, and other knitting, doubling, and entanglement may be performed.

  The fabric of the present invention may be dyed including mixed fabrics. For example, it is preferable to take a process of scouring, presetting, dyeing, and final setting by a conventional method after weaving and weaving. Further, if necessary, it is also preferable to carry out an alkali reduction treatment by a conventional method after scouring and before dyeing. The scouring is preferably performed in a temperature range of 40 to 98 ° C. In particular, in the case of mixed use with stretch fibers, it is more preferable to scour the fabric while relaxing because it improves elasticity. One or both of the heat sets before and after dyeing can be omitted, but it is preferable to carry out both in order to improve the form stability and dyeability of the fabric. The heat setting temperature 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 according to the present invention uses, for example, sports clothing (golf wear, gateball, baseball, tennis, soccer, table tennis, volleyball, basketball, rugby, American football, hockey, athletics, etc. by utilizing excellent lightness and fiber properties. , Triathlons, speed skates, ice hockey uniforms), swimwear, infant clothing, women's clothing, elderly clothing, outdoor clothing (shoes, bags, supporters, socks, climbing clothes), etc. It is also suitably used for various vehicle interior materials such as railways, airplanes, ships, etc., BCF, or packing materials used for various transportations.

  Hereinafter, the present invention will be described specifically and in detail by way of examples. In the present invention, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) will be described as an example of the fiber material, and the examples will be described. However, the present invention is not limited to the following examples. In addition, the physical-property value in an Example was measured with the following method.

A. Measurement of fiber strength Using a Tensilon tensile tester manufactured by Orientec Co., Ltd., an initial sample length of 200 mm and a tensile speed of 200 mm / min were measured, and an average value measured five times was used as a measured value.

B. Measurement of Apparent Specific Gravity and Calculation of Porosity The apparent specific gravity of the fiber is based on the float / sink method defined in JIS-L-1013: 1999 8.17.1 (published by Japanese Standards Association, chemical fiber filament yarn test method). The measured specific gravity value (Q) was measured. The following formula was used for calculation of the porosity.
Porosity (%) = 100 (1-Q / R),
R = 100 / (S / V + (100−S) / Vp),
However, S: addition amount (weight%) of thermoplastic polymer,
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 was used for drawn yarn)
R: Apparent specific gravity of polyester composite fiber without voids Confirmation of fiber diameter and dispersion diameter of island components Using a scanning electron microscope ESEM-2700 manufactured by Nikon Corporation, platinum-palladium deposition (deposition film pressure: 25 to 50 angstroms) is performed at an acceleration voltage of 10 kV. Then, it confirmed with the arbitrary magnifications between 2000 times and 20000 times magnification. Samples were prepared by cooling the fibers and blades used as samples in liquid nitrogen and cutting them in liquid nitrogen after cooling for 15 minutes.

D. Confirmation of discontinuity of island component (dispersion length in fiber axis direction) 0.1 g of the obtained polyester composite fiber is impregnated in 200 ml of 0.1N sodium hydroxide aqueous 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 which is an island component, collected with a dropper, and observed with an optical microscope at about 100 to 600 times. For the discontinuity, the ratio β / α of the diameter (α) of one dispersed island in the cross section of the fiber single yarn of the island component and the length (β) of the dispersion in the fiber axis direction is obtained and observed. The maximum possible ratio was used as an index of the discontinuity of the fiber.

E. Evaluation of stretchability Regarding the stretchability in the stretching process, when 1 kg of unstretched yarn is stretched, it is evaluated by the number of times that single yarn breakage occurs and the single yarn is wound around the stretching roller. X (impossible) when the yarn is wound, △ (inferior) when the single yarn is wound 10 times or more and 19 times or less, ○ (good) when the number of times the single yarn is wound is 4 times or more and 9 times or less, The number of times the yarn was wound was evaluated as a double circle (excellent) when it was 3 times or less.

F. Measurement of Glass Transition Temperature (Tgp or Tg) and Melting Point (Tm) Measurement was performed with a differential scanning calorimeter (DSC-2) manufactured by PerkinElmer Co., Ltd., with a sample temperature of 10 mg and a heating rate of 16 ° C./min. The definitions of Tm and Tg are as follows: after observing the endothermic peak temperature (Tm1) observed once at a rate of temperature increase 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 room temperature holding time are kept for 5 minutes), and when the measurement is again performed at a temperature rise of 16 ° C./min, the endothermic peak temperature observed as a step-like baseline deviation is defined as Tg, and the melting temperature of the crystal And the endothermic peak temperature observed as Tm.

G. 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 Using 5 kinds of liquid selected from 59.3 dyne / cm organic solvent or aqueous solution of 5% ammonia water, a liquid is placed on a solid at 20 ° C. and humidity of 40 to 80% under standing conditions. When the droplet is stationary, the angle formed by the solid plane in contact with the droplet and the surface of the droplet in contact with the air layer is measured as the contact angle θ, and the cos θ is calculated with respect to the surface tension of the liquid used. Plot (Zisman plot) and extrapolate the plotted points for the surface tension when wetting is complete, ie cos θ = 1. The field surface tension was determined.

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

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

  Using this polyester, melt spinning is performed using a biaxial extruder type melt spinning machine at a spinning temperature of 290 ° C. using a die having a hole diameter of 0.3 mm and a number of holes of 24, at a take-up speed of 1200 m / min. The polyester multifilament fiber having a round cross section of 292 dtex-24 filament was obtained. No yarn breakage occurred during spinning, and the yarn making property was excellent.

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

Reference example 1
Polyester pentene (TPX (registered trademark)) manufactured by Mitsui Chemicals, Inc. was used as a thermoplastic polymer (excluding polyester) when melt spinning using a biaxial extruder type melt spinning machine using the polyester obtained in the Reference Example. (Trademark), type RT18, and the same type of the same product was used unless otherwise specified. Hereinafter, melt spinning was carried out in the same manner as in the Reference Example by adding 8% by weight of PMP). The film was stretched at a magnification of 3.5. The fiber properties such as strength or specific gravity of the obtained fiber, as well as the spinning property and stretchability were good. The results of Reference Example 1 are shown in Table 1.

Comparative Example 1
A styrene maleimide copolymer (manufactured by Denki Kagaku Kogyo Co., Ltd.) is used as a thermoplastic polymer (excluding polyester) when performing melt spinning using a polyester obtained in the Reference Example using a twin-screw extruder melt spinning machine. 10% by weight of MSN (average molecular weight of about 110,000, hereinafter abbreviated as MSN) was added and 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. The fiber properties such as strength and specific gravity of the obtained fiber were almost the same as those shown in Example 1 of Patent Document 1 (Japanese Patent Laid-Open No. 2000-154427). As for the yarn-making property or drawability, yarn breakage frequently occurred and the draw ratio was inevitably lowered, and in addition, the fiber strength was low as compared with Examples. Further, the obtained yarn and the drawn yarn obtained in Reference Example 1 were visually compared, and clear yellowing presumed to be caused by the addition of MSN was observed. The results of Comparative Example 1 are shown in Table 1.

Comparative Example 2
When performing melt spinning using the polyester obtained in Reference Example and the PMP of Reference Example 1, using a core / sheath compound spinning machine, the polyester is the sheath and PMP is the core, and the weight ratio is 8:92. The core-sheath 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 fiber properties such as strength or specific gravity of the obtained fiber. Although the yarn-making property and stretchability were good, the fiber was hardly reduced in weight to the extent that the core-sheath interface was peeled off.

Comparative Example 3
When performing melt spinning using the polyester obtained in Reference Example and the PMP of Reference Example 1, the weight fraction of polyester and PMP was PMP: polyester = 8: 92 using a normal pressure melter type melt spinning machine. As shown, melt-spinning is performed by filling the hopper with a dry-blended product in a chip state and kneading it in the polymer channel until it is discharged from the spinneret (mixer in the polymer channel). Etc. are not provided), and other yarns were produced under the same conditions as in the reference example to obtain fibers, and then stretched at a magnification of 3.5 times in the same manner as in the reference example. Table 1 shows the results of fiber properties such as strength or specific gravity of the obtained fiber. The spinning property and stretchability were very poor, and the stretching could not be carried out continuously for more than 5 minutes. Moreover, 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 exceeded 5 μm.

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

Comparative Example 4
In Reference Example 2, melt spinning and stretching were performed in the same manner as in Reference Example 2, except that PMP was not added. The results of Comparative Example 2 are shown in Table 1. When no PMP was added, the yarn-making property and stretchability were excellent, but no voids were seen and the weight was not reduced.

Reference example 3
In Reference Example 2, 15% by weight of polypropylene (grade J108M, hereinafter abbreviated as PP) made by Grand Polymer Co., Ltd. as a thermoplastic polymer (excluding polyester), butylene terephthalate and poly (tetramethylene oxide) glycol as compatibilizers Example 2 except that the copolymer (PBT-PTMG; 10% copolymerized poly (tetramethylene oxide) glycol component) was added in an amount of 20% by weight based on the added amount of PP. In this way, melt spinning and stretching were performed. The obtained drawn yarn had excellent fiber physical properties such as strength and specific gravity, and excellent drawability. The results of Reference Example 3 are shown in Table 1.

Reference example 4
In Reference Example 2, 15% by weight of Mitsui Chemicals Co., Ltd. polyethylene (Hizex (registered trademark), grade 8200B, hereinafter abbreviated as PE) was used as the thermoplastic polymer (excluding polyester), and a compatibilizer manufactured by Meisei Chemical Industries, Ltd. The same method as in Reference 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. And melt spinning. Subsequently, stretching was performed at a magnification of 3.6 times in the same manner as in the reference example. The obtained drawn yarn was excellent in fiber physical properties such as strength and specific gravity, and was excellent in drawability. The results of Reference Example 4 are shown in Table 1.

Reference Examples 5-8
In Reference Example 2, melt spinning was carried out in the same manner as in Reference Example 2, except that the PMP content was variously changed and the compatibilizer PET-PEG was added in an amount of 40% by weight based on the PMP content. . Then, in the same manner as in the reference example, the reference examples 5 and 7 were stretched at a magnification of 3.7 times, and the reference examples 6 and 8 were stretched at a magnification of 3.3 times.
As apparent from Table 2, even in Reference Examples 5 and 6 towards the Reference Examples 7 and 8 were excellent in lightweight properties and fiber properties. That is, when the content of the thermoplastic polymer (excluding polyester) is set to an appropriate amount, the obtained drawn yarn has superior lightness or fiber properties.

Reference Examples 9-12
In Reference Example 3, the melt spinning was carried out in the same manner as in Reference Example 3, except that the PP content was 10% by weight and the compatibilizer PBT-PTMG was variously changed with respect to the PP content. went. Subsequently, the film was stretched at a magnification of 3.5 times in the same manner as in the reference example. As apparent from Table 2, even in Reference Examples 9 and 10 towards the reference example 11 and 12 were excellent in lightweight properties and fiber properties. That is, when the content of the compatibilizing agent is set to an appropriate amount, the drawn yarn obtained has superior lightness or fiber properties.

Examples 13 and 14
In Reference Example 2, as a thermoplastic polymer (excluding polyester), a norbornene resin Arton (registered trademark, Example 13, type F5023) manufactured by JSR Corporation or Iupiace (registered trademark, Examples) manufactured by Mitsubishi Engineering Plastics Co., Ltd. 14, type AH90) was melt melt-spun and stretched in the same manner as in Reference Example 2 except that 10% by weight of each was added. The obtained drawn yarn had excellent fiber physical properties such as strength and specific gravity, and excellent drawability. The results of Examples 13 and 14 are shown in Table 3. Arton or Iupiace was found to have excellent compatibility with polyester even without a compatibilizing agent, a high glass transition temperature, and excellent lightness. In addition, no yellowing was observed.

Example 15
In Reference Example 2, 10% by weight of ZEONOR (registered trademark, type 1600R, hereinafter referred to as ZEONOR) manufactured by Nippon Zeon Co., Ltd. as a thermoplastic polymer (excluding polyester) and PET-PEG as a compatibilizing agent with respect to the added amount of ZEONOR Melt spinning and stretching were performed in the same manner as in Reference Example 2 except that 40 wt% was added. The obtained drawn yarn had excellent fiber physical properties such as strength and specific gravity, and excellent drawability. The results of Example 15 are shown in Table 3. From the fact that zeonore has a high glass transition temperature, it was found that the obtained fiber was very lightweight and showed no yellowing.

Reference Example 16
To a low polymer obtained by ordinary esterification reaction from 166 parts by weight of terephthalic acid and 75 parts by weight of ethylene glycol, 0.03 part by weight of 85% phosphoric acid aqueous solution as a coloring inhibitor and antimony trioxide as a polycondensation catalyst The polycondensation reaction was performed by adding 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.

  Dimethyl terephthalate 130 parts (6.7 mole parts), 1,3-propanediol 114 parts (15 mole parts), calcium acetate monohydrate 0.24 parts (0.014 mole parts), lithium acetate dihydrate To a low polymer obtained by transesterifying 0.1 parts (0.01 mol) of salt and distilling off methanol, 0.065 parts of trimethyl phosphate and 0.134 parts of titanium tetrabutoxide were added. The polycondensation reaction was performed while distilling off 1,3-propanediol, and a chip-shaped prepolymer was obtained. 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) of IV1.12.

When melt spinning and stretching are performed using the obtained PPT in the same manner as in the reference example, 7% by weight of PMP manufactured by Mitsui Chemicals (however, type DX881, hereinafter abbreviated as PMP881) as a thermoplastic polymer (excluding polyester) is used. As a compatibilizer, Nippon Steel Chemical Co., Ltd. styrene (registered trademark, type MS200, hereinafter referred to as styrene) was added in an amount of 29% by weight with respect to the added amount of PMP881, respectively, and the spinning temperature was 260 ° C. and the temperature of the hot plate during stretching was adjusted. Melt spinning and stretching were performed in the same manner as in the reference example except that the temperature was 80 ° C. and the draw ratio was 4.5 times. The obtained drawn yarn was excellent in fiber properties such as strength and specific gravity, and was excellent in drawability. The results of Reference Example 16 are shown in Table 3.

Example 17
In Reference Example 16, 15% by weight of Mitsui Chemicals Appel (registered trademark, type 6015T, hereinafter referred to as Appel) was used as the thermoplastic polymer (excluding polyester), and Hytrel (registered trademark, Type 4057) manufactured by Toray DuPont Co., Ltd. was used as the compatibilizing agent. , Hereinafter Hytrel) was melt-spun and stretched in the same manner as in Reference Example 16 except that 13% by weight of each was added to the added amount of appel. The obtained drawn yarn had excellent fiber physical properties such as strength and specific gravity, and excellent drawability. The results of Example 17 are shown in Table 3.

Reference 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 carrying out nitrogen substitution, the reaction is carried out at 170 ° C. to obtain polylactic acid (hereinafter referred to as PLA) having a weight average molecular weight of 153,000. Obtained.

When melt spinning and stretching are performed using the obtained PLA in the same manner as in the reference example, 5% by weight ( reference example 18) or 10% by weight ( reference example 19) of PMP881 as a thermoplastic polymer (excluding polyester) is used. In addition, in Reference Example 19, 30% by weight of Type R-150 having an average molecular weight of 100,000 of Alcox (registered trademark) used in Reference Example 4 as a compatibilizer was added to the amount of PMP881 added. The melt spinning and stretching were performed in the same manner as in the 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 times. The obtained drawn yarn had excellent fiber physical properties such as strength and specific gravity, and excellent drawability. The results of Reference Examples 18 and 19 are shown in Table 3.

  Uniform garments such as white garments, underwear, T-shirts, shirts, swimwear, women's garments, men's garments, etc., as well as sports clothing such as golf wear, gateball, Wear and uniforms such as baseball, tennis, soccer, table tennis, volleyball, basketball, rugby, American football, hockey, athletics, triathlon, speed skating, ice hockey, etc., or outdoor sports applications such as shoes, bags, supporters, socks, climbing It can also be suitably used as a garment. In addition, automotive interior materials such as carpets and wall materials for automobiles, ships, airplanes, railways, etc., as well as ropes, tents, curtains, blinds, etc., which are required to be lightened due to energy savings as industrial materials. Alternatively, it is also suitably used for materials that require light shielding properties such as packing materials used for various transportations.

Claims (7)

In the sea-island polyester composite fiber composed of polyester and a thermoplastic polymer having no maleimide structure (excluding polyester), the following (1) to ( 4 ) are satisfied, and at least part of the sea-island composite interface has voids, A polyester composite fiber characterized by having an apparent specific gravity of 1.2 or less and a fiber strength of 4.0 cN / dtex or more.
(1) In a fiber single yarn cross section, polyester is a sea component and thermoplastic polymer (excluding polyester) is two or more island components.
(2) The island component is discontinuously dispersed in the fiber axis direction.
(3) The maximum dispersion diameter in the cross section of the fiber single yarn of the island component is 5 μm or less.
(4) The glass transition temperature (Tg) of the island component is 130 ° C. or higher. The polyester composite fiber according to claim 1, wherein the content of the island component is 1 to 30% by weight. The polyester composite fiber according to claim 1 or 2, wherein the island component has a critical surface tension of 10 to 35 dyn / cm. The density of an island component is 1.0 g / cm < ³ > or less, The polyester composite fiber of any one of Claims 1-3 characterized by the above-mentioned. The polyester composite fiber according to any one of claims 1 to 4 , wherein the island component has a melting point (Tm) of 150 ° C or higher. The polyester composite fiber according to any one of claims 1 to 5, wherein the polyester composite fiber contains a compatibilizing agent, and the content of the compatibilizing agent is 10 to 200% by weight based on the island component . A fiber product comprising the polyester conjugate fiber according to any one of claims 1 to 6 in part or in whole.