JP2009052160A - Fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber which can improve the strength and can suitably be used for reinforcing rubbers such as industrial materials, especially tire cords and cap materials, because of maintaining a molecular weight and controlling the inhibition of extension and deformation in spinning and drawing steps. <P>SOLUTION: This fiber including a polymer blend obtained by blending a thermoplastic matrix polymer with 0.1 to 10 wt.% of a dendritic polyester having structural units of an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), and an aromatic dicarbonyl unit (R) and tri- or more-functional organic residues (B), wherein the content of the component B is within the range of 7.5 to 50 mol% based on the total monomer content constituting the dendritic polyester, wherein an NDR ratio calculated by the following equation is more than 30%. NDR ratio = natural draw ratio / breaking elongation × 100 (%). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fiber comprising a polymer blend obtained by blending a dendritic polyester with a matrix polymer.

  Fibers using thermoplastic polymers such as polyester and polyamide are widely used, and the industrial value is extremely high. And these manufacturing methods employ | adopt melt spinning which extrudes from a thin nozzle | cap | die after melt | dissolving a polymer. At this time, the spinning temperature in melt spinning is determined by the melting point and melt viscosity of the polymer, but even when the melting point is the same, when spinning a high viscosity polymer, it is necessary to set a higher spinning temperature than in the case of a low viscosity polymer. There is. However, when the temperature is excessively high, decomposition of the polymer itself is promoted. In addition, in order to add functionality to the fiber, the function-added component is spun simultaneously. If the heat-resistant component of this function-added component is low, decomposition and accompanying gas may be generated. For this reason, in particular, when spinning a high viscosity polymer or simultaneously spinning a functional addition component having low heat resistance, a technique for improving the fluidity of the polymer and lowering the spinning temperature as much as possible is important.

  For this reason, various thinning agents may be used, but there have been few successful examples to date. Of particular interest among conventional techniques is an example in which a hyperbranched polymer (hyperbranched polymer) is added to nylon (Patent Document 1). Here, it is described that by adding a hyperbranched polymer that is non-reactive with the matrix polymer to the matrix polymer, the molecular weight reduction is less than 7% and the fluidity is improved as compared with the case where the matrix polymer is not added. However, since the branch structure portion (D) that is the main chain of the hyperbranched polymer is actually aliphatic (in the examples, derived from ε-caprolactam), the flexibility is extremely high. For this reason, even if the hyperbranched polymer and the matrix polymer are non-reactive, there is a possibility that many so-called molecular chains are entangled between the hyperbranched polymer main chain part and the matrix polymer main chain part. This is not a big problem because the amount of deformation is small in extrusion processing of resin and shear deformation is dominant, but it causes serious problems especially when accompanied by large elongation deformation such as spinning. was there. That is, the degree of entanglement of the molecular chains is increased, so that the smooth elongation deformation of the matrix polymer molecular chains is hindered, and the spinnability is remarkably deteriorated. In some cases, the elastic behavior of the polymer becomes remarkable and the spinning becomes impossible. there were. In addition, since the undrawn yarn obtained does not become unspinnable, the stretchability of the obtained unstretched yarn is low, so that it is difficult to improve the strength even if it is stretched, and fibers suitable for industrial materials may not be obtained. It was. This tendency was particularly remarkable when a high viscosity polymer or a high molecular weight polymer was used as the matrix polymer.

For this reason, a hyperbranched polymer suitable for spinning and fiber and a fiber to which this polymer is added have been demanded.
JP-T-2005-513186 (page 6-12)

  Unlike conventional ones, by using dendritic polyester that is difficult to inhibit elongation deformation, the fluidity in the spinning process is improved and the spinning temperature is lowered to suppress the IV drop during melt spinning, and the matrix polymer Since the entanglement of the molecular chain is suppressed, the strength is improved in the drawing step, and a fiber having excellent mechanical properties is provided.

The above object is achieved by the following means.
(1) an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), a structural unit composed of an aromatic dicarbonyl unit (R), and a trifunctional or higher functional organic residue (B); From a polymer blend in which a dendritic polyester having a B content in the range of 7.5 to 50 mol% with respect to all monomers constituting the dendritic polyester is blended with a thermoplastic matrix polymer in an amount of 0.1 to 10 wt%. A fiber comprising an NDR ratio calculated by the following formula of 30% or more,
NDR ratio = natural stretch ratio / breaking elongation × 100 (%)
(2) a structural unit composed of an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), and an aromatic dicarbonyl unit (R) and a trifunctional or higher functional organic residue (B), and From a polymer blend in which a dendritic polyester having a B content in the range of 7.5 to 50 mol% with respect to all monomers constituting the dendritic polyester is blended with a thermoplastic matrix polymer in an amount of 0.1 to 10 wt%. A fiber having a strength of 5.0 cN / dtex or more,
(3) The fiber according to (1) or (2), wherein the thermoplastic matrix polymer is polyester,
(4) The fiber according to any one of (1) to (3), wherein the total carboxyl end group amount is less than 50 eq / ton,
(5) U% is 0.1 to 5% or less, The fiber according to any one of (1) to (4),
(6) The fiber according to any one of (2) to (5), wherein the single yarn fineness is 1 to 15 dtex,
(7) The fiber according to any one of (2) to (6), wherein the elastic modulus is 110 cN / dtex or more,
(8) A textile product using at least a part of the fiber according to any one of (1) to (7),
It is.

  The fiber of the present invention can suppress the inhibition of elongation and deformation in the spinning and stretching process while maintaining the molecular weight, so that the strength can be improved, and industrial materials, particularly tire cords and cap materials are used. It can be suitably used for applications intended to reinforce rubber.

  The dendritic polyester referred to in the present invention is a kind of hyperbranched polymer, but the dendritic polyester used in the present invention is composed of an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), and an aromatic diester. It contains a structural unit composed of a carbonyl unit (R) and a trifunctional or higher functional organic residue (B), and the B content is 7.5 to 50 mol with respect to all monomers constituting the dendritic polyester. % Dendritic polyester in the range of%.

  Here, the aromatic oxycarbonyl unit (P), the aromatic dioxy unit (Q), and the aromatic dicarbonyl unit (R) are each preferably a structural unit represented by the following formula (1).

  Here, R1, R2, and R3 are each an aromatic residue. R1, R2, and R3 may each include a plurality of structural units.

  Examples of the aromatic residue include a substituted or unsubstituted phenylene group, naphthylene group, and biphenylene group. R1, R2 and R3 are preferably at least one structural unit selected from structural units represented by the following formulas.

  In the dendritic polyester of the present invention, the trifunctional or higher functional organic residue (B) is selected directly from an ester bond and / or an amide bond, or selected from P, Q and R constituting the branch structure part (D). The basic skeleton is a branched structure of three or more branches connected through a structural unit. The branched structure may be formed of a single basic skeleton such as three branches and four branches, or a plurality of basic skeletons such as three branches and four branches may coexist. It is not necessary for all of the polymers to be composed of the basic skeleton, and other structures may be included at the ends, for example, for end-capping. When B is a trifunctional organic residue, the dendritic polyester has a structure in which all three functional groups of B have reacted, a structure in which only two have reacted, and 1 A structure that reacts with only one may be mixed. Preferably, the structure in which all three functional groups of B have reacted is preferably 15 mol% or more, more preferably 20 mol% or more, and still more preferably 30 mol% or more based on the entire B. When B is a tetrafunctional organic residue, the dendritic polyester has a structure in which all four functional groups of B are reacted, a structure in which only three are reacted, two A structure in which only one reacts and a structure in which only one reacts may be mixed. Preferably, the structure in which all four functional groups of B are reacted is preferably 10 mol% or more with respect to the entire B, and the structure in which three functional groups are reacted is preferably 20 mol% or more, more preferably four functional groups. The structure in which the functional group is reacted is 20 mol% or more with respect to the entire B and the structure in which three functional groups are reacted is 30 mol% or more with respect to the entire B, more preferably the structure in which four functional groups are reacted is the entire B The structure in which three functional groups react with each other at 25 mol% or more is 35 mol% or more with respect to the entire B.

  B is preferably an organic residue of a trifunctional compound and / or a tetrafunctional compound, and most preferably an organic residue of a trifunctional compound.

  The above three-branch basic skeleton is schematically represented by the formula (2). Further, the above four-branch basic skeleton is schematically represented by the formula (3).

  The dendritic polyester of the present invention preferably exhibits molten liquid crystallinity. The term “showing melt liquid crystallinity” means that the liquid crystal state is exhibited in a certain temperature range when the temperature is raised from room temperature (25 ° C.). The liquid crystal state is a state showing optical anisotropy under shear.

  In order to exhibit molten liquid crystallinity, the basic skeleton in the case of three branches is a branched structure portion (D) in which B is composed of a structural unit selected from P, Q and R as shown by the following formula (4): It is preferable that it couple | bonds through.

  Similarly, the basic skeleton in the case of four branches is preferably a structure represented by the following formula (5).

  The trifunctional organic residue B is preferably an organic residue of a compound containing a functional group selected from a carboxyl group, a hydroxyl group and an amino group. For example, aliphatic compounds such as glycerol, 1,2,3-tricarboxypropane, diaminopropanol, diaminopropionic acid, trimesic acid, trimellitic acid, 4-hydroxy-1,2-benzenedicarboxylic acid, phloroglucinol, α Residues of aromatic compounds such as resorcinic acid, β-resorcinic acid, γ-resorcinic acid, tricarboxynaphthalene, dihydroxynaphthoic acid, aminophthalic acid, 5-aminoisophthalic acid, aminoterephthalic acid, diaminobenzoic acid, melamine are preferred Used. A residue of an aromatic compound represented by the following formula is more preferable.

  Specific examples of the above trifunctional organic residues include residues such as phloroglucinol, trimesic acid, trimellitic acid, trimellitic anhydride, α-resorcylic acid, 4-hydroxy-1,2-benzenedicarboxylic acid Are preferred, and more preferred are residues of trimesic acid and α-resorcylic acid.

  The tetrafunctional or higher functional organic residue B is preferably an organic residue of a compound containing a functional group selected from a carboxyl group, a hydroxyl group and an amino group. For example, erythritol, pentaerythritol, threitol, xylitol, glucitol, mannitol, 1,2,3,4-butanetetracarboxylic acid, 1,2,4,5-cyclohexanetetraol, 1,2,3,4,5- Cyclohexanepentaneol, 1,2,3,4,5,6-cyclohexanehexaneol, 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,3,4,5-cyclohexanepentacarboxylic acid, 1, Residues of aliphatic compounds such as 2,3,4,5,6-cyclohexanehexacarboxylic acid, citric acid, tartaric acid, 1,2,4,5-benzenetetraol, 1,2,3,4- Benzenetetraol, 1,2,3,5-benzenetetraol, 1,2,3,4,5-benzenepentaneol, 1,2,3,4,5, -Benzenehexaneol, 2,2 ', 3,3'-tetrahydroxybiphenyl, 2,2', 4,4'-tetrahydroxybiphenyl, 3,3 ', 4,4'-tetrahydroxybiphenyl, 3, , 3 ′, 5,5′-tetrahydroxybiphenyl, 2,3,6,7-naphthalenetetraol, 1,4,5,8-naphthalenetetraol, pyromellitic acid, merophanic acid, planitic acid, meritic acid, 2,2 ′, 3,3′-biphenyltetracarboxylic acid, 2,2 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 3,3 ′, 5,5′-biphenyltetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-naphthaleneteto All, 1,4,5,8-naphthalenetetraol, 1,2,4,5,6,8-naphthalenehexaol, 1,2,4,5,6,8-naphthalenehexacarboxylic acid, gallic acid, A residue of an aromatic compound such as A residue of an aromatic compound represented by the following formula is more preferable.

  Specific examples of the tetrafunctional organic residue of the above formula include 1,2,4,5-benzenetetraol, 1,2,3,4-benzenetetraol, 1,2,3,5. -Residues such as benzenetetraol, pyromellitic acid, merophanic acid, planitic acid and gallic acid are preferred, and residues of gallic acid are particularly preferred.

  Further, the aromatic oxycarbonyl unit (P), aromatic dioxy unit (Q), and aromatic dicarbonyl unit (R) of the dendritic polyester are units constituting the branch structure portion (D) between the branches of the dendritic polyester. It is. p, q and r are the average contents (molar ratio) of the structural units P, Q and R, respectively, and preferably in the range of p + q + r = 1 to 10 moles with respect to 1 mole of the content b of B. . p + q + r is more preferably in the range of 2 to 6 moles. If the branch structure length is too long, an effect such as shear responsiveness based on a rigid and detailed dendritic structure and an effect of suppressing entanglement with the matrix polymer molecular chain are not preferable.

  The values of p, q and r are determined by, for example, dissolving dendritic polyester in a mixed solvent of 50% by weight of pentafluorophenol and 50% by weight of deuterated chloroform, and performing nuclear magnetic resonance spectrum analysis of proton nuclei at 40 ° C. It can obtain | require from the peak intensity ratio derived from a structural unit. The average content is calculated from the peak area intensity ratio of each structural unit, and the three decimal places are rounded off. The average chain length of the branch structure portion (D) is calculated from the area intensity ratio with the peak corresponding to the content b of B, and is set as p + q + r. In this case, the three decimal places are rounded off.

  The ratio of p to q and the ratio of p to r (p / q, p / r) are preferably in the range of 5/95 to 95/5, more preferably 10/90 to 90/10, It is preferably 20/80 to 80/20. If it is this range, liquid crystallinity is easy to express and it is preferable. It is preferable to set the ratio of p / q and p / r to 95/5 or less because the melting point of the dendritic polyester can be within an appropriate range. Further, it is preferable that p / q and p / r be 5/95 or more because the melted liquid crystallinity of the dendritic polyester can be expressed.

  q and r are preferably substantially equimolar, but either component can be added in excess to control the end groups. The ratio of q / r is preferably in the range of 0.7 to 1.5, more preferably 0.9 to 1.1. Equimolar here means that the molar amount in the repeating unit is equal and does not include the terminal structure. Here, the term “end structure” means the end of the branch structure portion (D). When the end is blocked, it means the end of the branch structure portion (D) closest to the end.

  In the formula (1), R1 is a structural unit derived from an aromatic oxycarbonyl unit, and specific examples thereof include a structural unit generated from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. A structural unit derived from p-hydroxybenzoic acid is preferred, and a structural unit derived from 6-hydroxy-2-naphthoic acid can be used in combination. Further, structural units derived from aliphatic hydroxycarboxylic acids such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, and hydroxycaproic acid may be contained within a range not impairing the effects of the present invention.

  R2 is an aromatic-derived structural unit, for example, 4,4′-dihydroxybiphenyl, hydroquinone, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, t-butylhydroquinone, phenyl Examples include structural units derived from hydroquinone, methylhydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane, and 4,4′-dihydroxydiphenyl ether. Preferably, it is a structural unit derived from 4,4'-dihydroxybiphenyl or hydroquinone, and a structural unit derived from 4,4'-dihydroxybiphenyl and hydroquinone is preferable from the viewpoint of controlling liquid crystallinity.

  In the dendritic polyester used in the present invention, it is particularly important that the R2 unit is a structural unit containing an aromatic. In other words, by adding aromaticity, the branch structure is given rigidity (preferably giving liquid crystallinity), entanglement with the matrix polymer molecular chain is suppressed, and elongation deformation is inhibited even in the case of large deformation such as spinning. This can be suppressed. Thereby, industrially sufficient spinnability (spinnability, stability, etc.) can be obtained. Moreover, since elongation deformation is not inhibited in the stretching step, the fiber has excellent mechanical properties.

  R3 is a structural unit derived from an aromatic dicarbonyl unit such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 1,2-bis (phenoxy) ethane-4. , 4′-dicarboxylic acid, 1,2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid and 4,4′-diphenyl ether dicarboxylic acid. A structural unit derived from terephthalic acid or isophthalic acid is preferred, and when both are used in combination, the melting point can be easily adjusted. In addition, a part of structural units derived from aliphatic dicarboxylic acids such as sebacic acid and adipic acid may be included within a range that does not affect the effects of the present invention.

  The branch structure portion (D) of the dendritic polyester of the present invention is preferably mainly composed of a polyester skeleton, but it is also possible to introduce a carbonate structure, an amide structure, a urethane structure, etc. to such an extent that the properties are not greatly affected. It is. Among them, it is preferable to introduce an amide structure. By introducing such another bond, compatibility with a wide variety of thermoplastic resins can be adjusted, which is preferable. As a method for introducing an amide bond, p-aminobenzoic acid, m-aminobenzoic acid, p-aminophenol, m-aminophenol, p-phenylenediamine, m-phenylenediamine, tetramethylenediamine pentamethylenediamine, hexamethylene Diamine, 2-methylpentamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, m-xyl Range amine, p-xylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (4-Aminocyclohexyl Aliphatic, alicyclic or aromatic such as methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis (aminopropyl) piperazine, aminoethylpiperazine It is preferable to copolymerize such an amine compound. Of these, copolymerization of p-aminophenol or p-aminobenzoic acid is preferred.

  Specific examples of the branch structure part (D) of the dendritic polyester include those composed of structural units derived from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, structural units derived from p-hydroxybenzoic acid, 6- A structural unit derived from hydroxy-2-naphthoic acid, a structural unit derived from 4,4′-dihydroxybiphenyl and a structural unit derived from terephthalic acid, a structural unit derived from p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl A structural unit derived from, a structural unit derived from terephthalic acid and a structural unit derived from isophthalic acid, a structural unit derived from p-hydroxybenzoic acid, a structural unit derived from 4,4′-dihydroxybiphenyl, a structural unit derived from hydroquinone, Composed of structural units derived from terephthalic acid and structural units derived from isophthalic acid, p- A structural unit derived from loxybenzoic acid, a structural unit derived from hydroquinone, a structural unit derived from 4,4'-dihydroxybiphenyl, a structural unit derived from terephthalic acid, and a structural unit derived from 2,6-naphthalenedicarboxylic acid, p- Examples include a structural unit derived from hydroxybenzoic acid, a structural unit derived from 6-hydroxy-2-naphthoic acid, a structural unit derived from hydroquinone, and a structural unit derived from terephthalic acid.

  Particularly preferred is that the branch structure part (D) is composed of the following structural units (I), (II), (III), (IV) and (V). Here, (I) is the structural unit (P), (II) and (III) are the structural unit (Q) (IV), and (V) is the preferred mode of the structural unit (R).

  When the branch structural part (D) is composed of the structural units (I), (II), (III), (IV) and (V), the content p of the structural unit (I) is 30-70 mol% is preferable with respect to the sum total p + q + r of a structural unit, More preferably, it is 45-60 mol%.

  Further, the content q (II) of the structural unit (II) is preferably 60 to 75 mol%, more preferably 65 to 73 mol% with respect to the total content q of the structural units (II) and (III). is there. Further, the content r (IV) of the structural unit (IV) is preferably 60 to 92 mol%, more preferably 60 to 70 mol%, with respect to the total content r of the structural units (IV) and (V). More preferably, it is 62-68 mol%.

  In such a case, it is preferable because the effects of the present invention, such as shear responsiveness and the addition effect to the thermoplastic resin, are remarkably exhibited.

  As described above, the total content q of the structural units (II) and (III) and the total content r of (IV) and (V) are preferably substantially equimolar. An excess may be added.

  The terminal of the dendritic polyester of the present invention is preferably a carboxyl group, a hydroxyl group, an amino group, or a derivative thereof. Examples of the hydroxyl derivative or carboxylic acid derivative include alkyl esters such as methyl ester and aromatic esters such as phenyl ester and benzyl ester. It is also possible to end-block using a monofunctional epoxy compound, an oxazoline compound, an ortho ester, an acid anhydride compound, or the like. The end-capping method includes adding a monofunctional organic compound in advance when synthesizing the dendritic polyester, or adding a monofunctional organic compound when the dendritic polyster skeleton is formed to some extent. The method etc. are mentioned.

  Specifically, when blocking the hydroxyl terminal or acetoxy terminal, benzoic acid, 4-t-butylbenzoic acid, 3-t-butylbenzoic acid, 4-chlorobenzoic acid, 3-chlorobenzoic acid, 4- It is possible by adding methylbenzoic acid, 3-methylbenzoic acid, 3,5-dimethylbenzoic acid, and the like.

  Moreover, the carboxyl group terminal blockade can be performed by reacting a carboxylic acid-reactive monofunctional compound. Here, the carboxylic acid-reactive monofunctional compound refers to a compound having one functional group in the molecule that can react with carboxylic acid at room temperature or when heated to form an ester, amide, urethane, or urea bond. The carboxylic acid-reactive monofunctional compound reacts with the carboxylic acid group present at the molecular end of the dendritic polyester, and the monofunctional compound is introduced at the molecular end, thereby improving the residence stability and hydrolysis resistance of the dendritic polyester. When it is improved and further kneaded with other thermoplastic resins and fillers, it can suppress the decomposition of thermoplastic resins and fillers, and improve the dispersibility of dendritic polyester, thereby improving fluidity and physical properties. Can be expected.

  The carboxylic acid-reactive monofunctional compound that can be used in the dendritic polyester of the present invention is at least one compound selected from oxazoline, epoxide, orthoester, isocyanate, carbodiimide, and diazo compound. From the viewpoint of reactivity with carboxylic acid and handling properties, oxazoline, epoxide, orthoester, and isocyanate can be preferably used. The carboxylic acid-reactive monofunctional compound may be used alone or in combination of two or more carboxylic acid-reactive monofunctional compounds.

  Among the carboxylic acid-reactive monofunctional compounds that can be used in the present invention, examples of the oxazoline compound include 2-methoxy-2-oxazoline, 2-ethoxy-2-oxazoline, 2-propoxy-2-oxazoline, and 2-butoxy. 2-oxazoline, 2-pentyloxy-2-oxazoline, 2-hexyloxy-2-oxazoline, 2-heptyloxy-2-oxazoline, 2-octyloxy-2-oxazoline, 2-decyloxy-2-oxazoline, 2 -Cyclopentyloxy-2-oxazoline, 2-cyclohexyl-2-oxazoline, 2-allyloxy-2-oxazoline, 2-methallyloxy-2-oxazoline, 2-phenoxy-2-oxazoline, 2-cresyl-2-oxazoline, 2-p-phenylphenoxy- -Oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-butyl-2-oxazoline, 2-pentyl-2-oxazoline, 2-hexyl-2-oxazoline 2-heptyl-2-oxazoline, 2-octyl-2-oxazoline, 2-nonyl-2-oxazoline, 2-decyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-isobutyl-2-oxazoline, 2 -Sec-butyl-2-oxazoline, 2-tert-butyl-2-oxazoline, 2-cyclopentyl-2-oxazoline, 2-cyclohexyl-2-oxazoline, 2-allyl-2-oxazoline, 2-methallyl-2-oxazoline , 2-crotyl-2-oxazoline, 2-phenyl-2- Kisazorin, 2-biphenyl-2-oxazoline. Of these, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-butyl-2 from the viewpoints of reactivity and affinity with dendritic polyester and heat resistance -Oxazoline, 2-isopropyl-2-oxazoline, 2-isobutyl-2-oxazoline, 2-sec-butyl-2-oxazoline, 2-tert-butyl-2-oxazoline, 2-phenyl-2-oxazoline, 2-biphenyl 2-Oxazoline is preferable, and 2-phenyl-2-oxazoline is particularly preferable.

  Among the carboxylic acid-reactive monofunctional compounds that can be used in the present invention, examples of the epoxy compound include N-glycidylphthalimide, N-glycidyl-4-methylphthalimide, N-glycidyl-4,5-dimethylphthalimide, N- Glycidyl-3-methylphthalimide, N-glycidyl-3,6-dimethylphthalimide, N-glycidyl-4-ethoxyphthalimide, N-glycidyl-4-chlorophthalimide, N-glycidyl-4,5-dichlorophthalimide, N- Glycidylsuccinimide, N-glycidylhexahydrophthalimide, N-glycidylmaleimide, N-glycidylbenzamide, N-glycidyl-p-methylbenzamide, N-glycidylnaphthamide, N-glycidylsteramide, o-phenylphenyl Sidyl ether, 2-methyloctyl glycidyl ether, phenyl glycidyl ether, 3- (2-xenyloxy) -1,2-epoxypropane, allyl glycidyl ether, butyl glycidyl ether, lauryl glycidyl ether, benzyl glycidyl ether, cyclohexyl glycidyl ether, α -Cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, glycidyl methacrylate ether, ethylene oxide, propylene oxide, styrene oxide, octane oxide, glycidyl acetate, glycidyl propionate, glycidyl butanoate, pentanoic acid Glycidyl ester, hexanoic acid glycidyl ester, octanoic acid glycidyl ester, decanoic acid glycidyl And glycidyl ester of neodecanoic acid and glycidyl benzoate. Of these, ethylene oxide, propylene oxide, butyl glycidyl ether, phenyl glycidyl ether, and benzoic acid glycidyl ester are preferred, and benzoic acid glycidyl ester is particularly preferred from the viewpoints of reactivity and affinity with the dendritic polyester.

  Among the carboxylic acid-reactive monofunctional compounds that can be used in the present invention, ortho ester compounds include, for example, trimethyl orthoacetate, triethyl orthoacetate, tripropyl orthoacetate, tributyl orthoacetate, tribenzyl orthoacetate, trimethyl orthoformate, ortho Triethyl formate, tripropyl orthoformate, tributyl orthoformate, tribenzyl orthoformate, trimethyl orthopropionate, triethyl orthopropionate, tripropyl orthopropionate, tributyl orthopropionate, tribenzyl orthopropionate, trimethyl orthobenzoate, trimethyl orthobenzoate Triethyl, tripropyl orthobenzoate, tributyl orthobenzoate, tribenzyl orthobenzoate and the like can be mentioned. Of these, trimethyl orthoacetate, triethyl orthoacetate, trimethyl orthoformate, triethyl orthoformate are preferred, and trimethyl orthoacetate or triethyl orthoacetate is particularly preferred from the viewpoints of reactivity and affinity with dendritic polyester and handling properties. .

  Among the carboxylic acid-reactive monofunctional compounds that can be used in the present invention, examples of the isocyanate compound include methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, heptyl isocyanate, octyl isocyanate, nonyl isocyanate, Examples include decyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, benzyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, p-nitrophenyl isocyanate, 2-chloroethyl isocyanate, stearoyl isocyanate, and p-toluosulfonyl isocyanate. Of these, methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, and phenyl isocyanate are preferable from the viewpoint of reactivity and affinity with the dendritic polyester, and phenyl isocyanate is particularly preferable.

  Among the carboxylic acid-reactive monofunctional compounds that can be used in the present invention, examples of the diazo compound include diazomethane, diazoethane, diazopropane, diazobutane, and trimethylsilyldiazomethane. Of these, diazomethane and trimethylsilyldiazomethane are preferably used from the viewpoint of reactivity and affinity with the dendritic polyester.

  Theoretically, it is possible to block the end by adding the organic compound used for blocking the end in an amount corresponding to the end group to be blocked. It is preferable to use 1.005 times equivalent or more, more preferably 1.008 times equivalent or more of the organic compound used for terminal blocking with respect to the equivalent amount of the terminal group to be blocked. Moreover, it is preferable that the addition amount of the organic compound used for terminal blockage is 2.5 times equivalent or less. If the amount of the compound used for terminal blocking is too small, the terminal blocking is not sufficient. On the other hand, if the addition amount is too large, an excessively added compound remains in the system and generates gas, which is not preferable.

  Further, the content of B is 7.5 mol% or more, more preferably 10 mol% or more, further preferably 20 mol% or more with respect to the content of all monomers constituting the dendritic polyester. . In such a case, the chain length of the branch structure portion (D) is preferable because the dendritic polyester is suitable for taking a dendritic form. The upper limit of the B content is 50 mol% or less, preferably 45 mol% or less, and more preferably 40 mol% or less.

  The dendritic polyester of the present invention may have a partially crosslinked structure as long as the properties are not affected.

  In the present invention, a method for producing a dendritic polyester can be produced according to a known polyester polycondensation method. A monomer containing at least one structural unit selected from the structural unit represented by R1, a monomer containing at least one structural unit selected from the structural unit represented by R2, and R3 A method comprising reacting a monomer containing at least one structural unit selected from structural units, and a trifunctional or higher polyfunctional monomer forming a trifunctional or higher functional organic residue (B), A method is preferred in which the addition amount (mol) of the polyfunctional monomer is 7.5 mol% or more with respect to the total monomer (mol) constituting the dendritic polyester. The addition amount of the polyfunctional monomer is more preferably 10 mol% or more, more preferably 15 mol% or more, and further preferably 20 mol% or more. Moreover, as an upper limit of addition amount, 50 mol% or less is preferable, More preferably, it is 33 mol% or less, More preferably, it is 25 mol% or less.

  Further, in the above reaction, after acylating a monomer containing at least one structural unit selected from structural units represented by R1, R2 and R3, a polyfunctional monomer having three or more functionalities is reacted. Is also preferable. Also, a mode in which a monomer containing at least one structural unit selected from the structural units represented by R1, R2 and R3, and a trifunctional or higher polyfunctional monomer is acylated and then subjected to a polymerization reaction is also available. preferable.

A preferable production method will be described by taking as an example the production of a dendritic polyester composed of the structural units (I), (II), (III), (IV) and (V) and a trimesic acid residue. .
(1) After synthesizing a liquid crystalline polyester oligomer from p-acetoxybenzoic acid, 4,4'-diacetoxybiphenyl, diacetoxybenzene, terephthalic acid and isophthalic acid by deacetic acid condensation polymerization reaction, trimesic acid is added to remove acetic acid A method for producing by polymerization reaction.
(2) A method of producing from p-acetoxybenzoic acid, 4,4′-diacetoxybiphenyl, diacetoxybenzene, terephthalic acid, isophthalic acid and trimesic acid by a deacetic acid condensation polymerization reaction.
(3) p-hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, hydroquinone, terephthalic acid and isophthalic acid are reacted with acetic anhydride to acylate the phenolic hydroxyl group, and then the liquid crystalline polyester is subjected to deacetic acid polycondensation reaction. A method in which an oligomer is synthesized and further trimesic acid is added and subjected to a deacetic acid polymerization reaction.
(4) Acetic anhydride is reacted with p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid and trimesic acid to acylate the phenolic hydroxyl group, and then by deacetic acid polycondensation reaction. How to manufacture.
(5) After synthesizing a liquid crystalline polyester oligomer from a phenyl ester of p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid diphenyl ester and isophthalic acid diphenyl ester by a dephenol polycondensation reaction, trimesic acid was added. In addition, a method of producing by dephenol polycondensation reaction.
(6) A method of producing from phenyl ester of p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, diphenyl ester of terephthalic acid, diphenyl ester of isophthalic acid and phenyl ester of trimesic acid by dephenol polycondensation reaction.
(7) After reacting p-hydroxybenzoic acid, terephthalic acid, isophthalic acid, and trimesic acid with diphenyl carbonate to form phenyl esters, respectively, 4,4′-dihydroxybiphenyl and hydroquinone are added, and dephenol polycondensation reaction is performed. How to manufacture.

  Of these, the production methods (1) to (5) are preferred, the methods (3) and (4) are more preferred, and the production method (3) is most preferred from the viewpoint of chain length control and steric regulation.

  In the production method of (3), the amount of acetic anhydride used is preferably 0.95 equivalents or more and 1.10 equivalents or less, and 1.00 equivalents or more and 1.10 equivalents or less in terms of chain length control. The amount is more preferably 08 equivalents or less, and most preferably 1.02 equivalents or more and 1.05 equivalents or less. It is possible to control the terminal group by controlling the amount of acetic anhydride or adding an excess of either a dihydroxy monomer or a dicarboxylic acid monomer.

  In order to increase the molecular weight, an amount corresponding to the amount of carboxylic acid of trimesic acid is added in excess of dihydroxy monomer such as hydroquinone or 4,4′-dihydroxybiphenyl to the dicarboxylic acid monomer, and the carboxylic acid in all monomers is increased. The acid and the hydroxyl equivalent are preferably combined. On the other hand, when the carboxylic acid is intentionally left in the terminal group, it is preferable not to add the dihydroxy monomer as described above excessively. Furthermore, when the hydroxyl group is intentionally left at the terminal, the dihydroxy monomer is added in excess of the carboxylic acid equivalent of trimesic acid, and the amount of acetic anhydride used is less than 1.00 equivalent of the phenolic hydroxyl group. preferable.

  By these methods, the dendritic polyester of the present invention can be selectively provided with a terminal group structure rich in reactivity with various thermoplastic resins. However, depending on the thermoplastic resin used as the matrix, the dispersion state may be more easily controlled by blocking the ends with a monofunctional epoxy compound or the like in order to suppress excessive reactivity.

  When the deacetic acid polycondensation reaction is performed, a melt polymerization method in which the reaction is carried out at a temperature at which the dendritic polyester melts, optionally under reduced pressure, to distill a predetermined amount of acetic acid and to complete the polycondensation reaction, is preferable. For example, in a reaction vessel equipped with a predetermined amount of p-hydroxybenzoic acid, 4,4′-dihydroxybiphenyl, hydroquinone, terephthalic acid, isophthalic acid and acetic anhydride, equipped with a stirring blade and a distillation pipe, and provided with a discharge port at the bottom. Prepare. The mixture is heated with stirring under a nitrogen gas atmosphere to acetylate the hydroxyl group, and then heated to 200 to 350 ° C. to perform a deacetic acid polycondensation reaction to distill acetic acid. When acetic acid is distilled to 50% of the theoretical distillation amount, a predetermined amount of trimesic acid is added and acetic acid is further distilled to 91% of the theoretical distillation amount to complete the reaction.

  As conditions for acetylation, the reaction temperature is preferably in the range of 130 to 170 ° C, more preferably in the range of 135 to 155 ° C. The reaction time is preferably 0.5 to 6 hours, more preferably 1 to 2 hours.

  The polycondensation temperature is a temperature at which the dendritic polyester is melted, and is preferably a melting point of the dendritic polyester + 10 ° C. or higher. Specifically, for example, it is in the range of 200 to 350 ° C, and preferably 240 to 280 ° C. The atmosphere for polycondensation is satisfactory even under atmospheric pressure nitrogen, but a reduced pressure is preferable because the reaction proceeds faster and the residual acetic acid in the system decreases. The degree of vacuum is preferably 0.1 mmHg (13.3 Pa) to 200 mmHg (26600 Pa), more preferably 10 mmHg (1330 Pa) to 100 mmHg (13300 Pa). Note that acetylation and polycondensation may be carried out continuously in the same reaction vessel, or acetylation and polycondensation may be carried out in different reaction vessels.

After the polycondensation reaction is completed, the reaction vessel is kept at a temperature at which the dendritic polyester melts, and is pressurized to, for example, 0.01 to 1.0 kg / cm ² (0.001 to 0.1 MPa), and the bottom of the reaction vessel The dendritic polyester is discharged in a strand form from the discharge port provided in. A mechanism that opens and closes intermittently is provided at the discharge port, and it is also possible to discharge liquid droplets. The discharged dendritic polyester is cooled by passing through air or water, and then cut or pulverized as necessary.

  The obtained pellet-like, granular or powdery dendritic polyester further removes water, acetic acid and the like by heat drying or vacuum drying, if necessary. Further, in order to finely adjust the degree of polymerization, or to further increase the degree of polymerization, solid phase polymerization can also be performed. In the solid phase polymerization, for example, the dendritic polyester obtained as described above is subjected to a temperature range of a melting point of the dendritic polyester from −50 ° C. to a melting point of −5 ° C. (for example, 200 to 300 ° C.) under a nitrogen stream or under reduced pressure. And heating for 1 to 50 hours.

  The polycondensation reaction of the dendritic polyester proceeds even without catalyst, but metal compounds such as stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, and magnesium metal can also be used.

  The dendritic polyester of the present invention preferably has a number average molecular weight of 1,000 to 40,000, more preferably 1,000 to 20,000, still more preferably 1,000 to 10,000, Preferably it is the range of 1,000-5,000. The number average molecular weight is a value measured as an absolute molecular weight by a GPC-LS (gel permeation chromatography-light scattering) method using a solvent in which the dendritic polyester is soluble.

  The melt viscosity of the dendritic polyester in the present invention is preferably 0.01 to 30 Pa · s, more preferably 0.5 to 20 Pa · s, and particularly preferably 1 to 10 Pa · s. In addition, this melt viscosity is a value measured by a Koka flow tester under the condition of a shear rate of 100 / s under the condition of the liquid crystal starting temperature of the dendritic polyester + 10 ° C.

  In the present invention, by blending the above-mentioned dendritic polyester with a matrix polymer, an effect of improving fluidity can be obtained and the spinning temperature can be lowered. This mechanism is estimated as follows. That is, J.H. Polym. Sci. Part B: Polum. Phys. , Vol. 34, 2433 (1996). According to the description, the viscosity of the polymer in the incompatible polymer blend is described by the molecular weight term + dispersion interaction term + slip effect term, but the dendritic polyester used in the present invention has a low molecular weight and dispersion interaction for the molecular weight term. It is considered that the fluidity of the polymer blend is improved by the dendritic structure for the term and the liquid crystal effect for the slip effect term. That is, it is possible to obtain a higher fluidity improving effect that cannot be obtained by simply blending a low-viscosity polymer, a liquid crystal polymer, or an aliphatic hyperbranched polymer. Also, Macromolecule, vol. 38, 10571 (2005). Then, when the sizes of the hyperbranched polymer and the normal linear polymer were compared with the same molecular weight, the hyperbranched polymer had a molecular size of 1/5 or less. Furthermore, Polymer, vol. 45, 7491 (2004), when the hyperbranched polymer and the normal linear polymer were evaluated for the entanglement between the molecules by the second virial coefficient A2, the hyperbranched polymer was A2 smaller by two orders of magnitude. It has been reported that there is very little intertwining. From the above, it is considered that the dendritic polyester used in the present invention behaves like an organic nanoparticle in the matrix polymer and improves the fluidity. Furthermore, since the R1, R2 and R3 portions are composed of aromatics, it is possible to control the entanglement of the molecular chains and suppress the inhibition of elongation deformation that has been a problem with conventional hyperbranched polymers. The original potential of the base polymer can be fully utilized while being melt-extrudable at a low temperature.

  In the present invention, it is important to blend the above-described dendritic polyester into a matrix polymer composed of 0.1 to 10 wt% of a thermoplastic polymer.

  Examples of the matrix polymer include polyester, polyamide, polyphenylene sulfide, polyolefin, polycarbonate, polyester carbonate, polyimide, polyamideimide, polyether ketone, polyether ether ketone, and polyvinylidene fluoride. Among them, polyester having high versatility and relatively high elastic modulus and polyphenylene sulfide having excellent heat resistance and chemical properties are preferable. In particular, a high molecular weight polyester having an intrinsic viscosity of 1.0 dL / g or more has an extremely high melting point although the melting point is not so high, and therefore the spinning temperature may be increased by about 10 to 20 ° C. compared to the case of polyester for clothing, This is useful from the viewpoint of maintaining a high molecular weight by inhibiting hydrolysis and thermal decomposition. In addition, although not general-purpose, polymers such as polyketone, polyetheretherketone, polyimide, and polyvinylidene fluoride, which are usually high in spinning temperature, are preferable polymers in view of the effect of lowering the spinning temperature due to the fluidity improving effect. It is. In particular, the effect of lowering the spinning temperature is useful for polymers that easily generate corrosive substances and harmful substances such as polyvinylidene fluoride. In particular, in the case of a high molecular weight polymer having a molecular weight of 100,000 or more, the effect of suppressing the entanglement of molecular chains is useful. In particular, in the present invention, from the viewpoint of versatility, it is preferable to use high molecular weight polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) having an intrinsic viscosity of 1.0 dL / g or more as the matrix polymer. Further, it is preferable to use a polylactic acid having a weight average molecular weight of 150,000 or more and a stereocomplex polylactic acid having an improved melting point as the matrix polymer, which has a high spinning temperature and easily undergoes thermal decomposition.

  Moreover, if the blend rate is 0.1 wt% or more, a spinning temperature lowering effect due to an improvement in fluidity or an elastic modulus is recognized, and if it is 0.7 wt% or more, the effect is further improved and preferable. On the other hand, by setting the blend rate to 10 wt% or less, good spinnability can be achieved without significantly inhibiting elongation deformation. Preferably it is 2 wt% or less.

It is important that the fiber of the present invention is an undrawn yarn and the NDR ratio calculated by the following formula is 30% or more.
NDR ratio = natural stretch ratio / breaking elongation × 100 (%)
In general, in the stress-strain curve (FIG. 1) obtained by a tensile test of a material, the stress is almost constant between the first yield point (FIG. 1-1) and the second yield point (FIG. 1-2). After exhibiting a region indicating the so-called constant stress elongation region, the stress increases with respect to the strain through the second yield point and breaks (FIGS. 1-3). The natural stretch ratio referred to in the present invention is the strain amount at the end point of the constant stress elongation region, that is, the strain amount up to the second yield point (FIG. 1-2). This means the amount of distortion at the point (FIGS. 1-3). The constant stress elongation region is a region where the neck is fluidly propagated and stretched, and the natural stretch ratio corresponds to the amount of strain at which the neck fluidly propagates. When there is a factor such as entanglement of molecular chains that hinders extensional deformation, propagation of the neck is inhibited, so that the natural stretch ratio is significantly lowered. In the case of the same polymer, the natural stretch ratio is known to increase by lowering the spinning tension (for example, lowering the spinning speed), but at the same time, the elongation at break also increases. By evaluating the NDR ratio, it is possible to evaluate the history of elongation deformation during spinning or the ease of elongation deformation of the fiber. The molecular chain becomes a structure with some degree of order from a disordered state in the constant stress extension region, but if this region is low, the disordered structure is exposed to high stress and not only frequent thread breakage occurs. Even if yarn breakage is suppressed, the portion where the constraint of the molecular chain is strong is locally oriented, so that there is a limit to the mechanical properties of the drawn yarn obtained. In order to improve the mechanical properties of the drawn yarn and increase the competitiveness in industrial material applications, the NDR ratio is preferably 45% or more. The higher the NDR ratio, the better, but it is 70% as a feasible range. Since the fiber of the present invention is intended for industrial materials, the higher the mechanical properties of the drawn yarn, the more it can be used for various applications. Needless to say, high strength is required for use in the case of industrial materials, but there are few cases where fibers are used as they are, and processing such as twisting is required. In many cases, these processes are exposed to high stress, and the fiber of the present invention is a drawn yarn and needs to have a strength of 5.0 cN / dtex or more in order to improve the processability. is there. Regarding the strength of the drawn yarn, it is better to be higher for the reasons described above. For example, when used for a tire cord or the like, if the strength of the drawn yarn is high, the amount of fiber used for the cord should be reduced. And the weight of the tire can be reduced. For this reason, it is preferable that it is 7.0 cN / dtex or more preferably, and 20 cN / dtex is mentioned as a realistic upper limit. In industrial material applications, stretching and compression are often repeated, and fibers with a low elastic modulus, that is, with a narrow elastic deformation region, undergo plastic deformation of the fiber over time, resulting in deterioration of mechanical properties and breakage. Deterioration progresses as A fiber having an excellent elastic modulus can bear the stress of elongation and compression by elastic deformation, so that plastic deformation is small and deterioration of the fiber and the structural material can be minimized. For this reason, in the fiber of this invention, it is preferable that an elasticity modulus is 110 cN / dtex or more, and it uses suitably not only for rubber reinforcement uses, such as a tire cord and a tire cap material, but also for a fishing net, agricultural materials, etc. Can do. A more preferable range is 130 cN / dtex or more, and a practical upper limit is 2000 cN / dtex.

  The elongation of the fiber of the present invention is preferably 2 to 60% for the drawn yarn, and particularly 2 to 30% in view of wear resistance even in industrial material applications that require strength and elastic modulus. In addition to wear resistance, it is necessary to consider durability such as hydrolysis in industrial materials. It is known that when the amount of all carboxyl end groups in the undrawn yarn or drawn yarn is large, the deterioration is promoted by autocatalytic reaction. In order to suppress this, the amount of total carboxyl end groups is 50 eq / It is preferably less than ton, and it is known that degradation due to hydrolysis proceeds when processed into a cord or used as a tire when used as an industrial material, particularly a tire cord or cap material. (Journal of the Textile Society of Japan, Vol. 41, No. 11, T-471 (1985)), and the total carboxyl end group amount is 35 eq / ton for use in rubber reinforcement applications such as tire cords and cap materials. More preferably. A realistic upper limit is 0 eq / ton.

  In the fiber of the present invention, it is important that the Wooster spot (U%), which is an index of thick and thin threads, is 5% or less. As a result, the unevenness in the longitudinal direction of the strength and elastic modulus of the yarn is reduced, and the material design is facilitated particularly when used for industrial materials. Although U% is preferably as small as possible, the practical lower limit is 0.1%.

  The fiber of the present invention preferably has a single yarn fineness of 1 to 15 dtex of the drawn yarn, and the resin and the fiber are well adapted when impregnated with other resins such as industrial materials, particularly rubber reinforcement. More preferably from the viewpoint of, for example, 1 to 8 dtex.

  In the fiber of the present invention, the NDR ratio can be increased as compared with the case where a conventional hyperbranched polymer is added. This is estimated as follows. That is, in the dendritic polyester of the present invention, since R1, R2 and R3 are composed of aromatics, they do not inhibit the elongation deformation of the matrix polymer during spinning and stretching, so that the molecular chain is locally restricted during spinning. Thus, unnecessary orientational crystallization due to spinning tension is suppressed, and elongation deformation is not inhibited during stretching. Even with a high molecular weight PET having an intrinsic viscosity of 1.0 dL / g or more, a sufficient effect can be obtained by adding 1 wt%.

  The above-described fibers can be made into various fiber products such as fiber winding packages, tows, cut fibers, cotton, fiber balls, cords, piles, knitted fabrics, nonwoven fabrics, paper, and liquid dispersions.

  An example of a method for obtaining the fiber of the present invention will be described. The dendritic polyester is as described above, and for blending and fiberizing, for example, the following methods can be used. That is, a dendritic polyester having a molecular weight in the range of 2000 to 5000 having a terminal acetyl group blocked with benzoic acid in a dendritic polyester composed of the above structural units (I) to (V) and a trimesic acid residue, and a matrix polymer Is dried if necessary and introduced into a twin screw extruder. At this time, the blending apparatus is preferably a biaxial extrusion kneader in order to reduce blend spots. Here, the produced polymer blend may be guided directly to a spinning machine or may be once pelletized as a master pellet. In order to save labor, kneaded direct spinning is preferable, but master pelletization is preferable in order to provide versatility such as making several varieties having different dendritic polyester blend ratios and polyester molecular weights. Also, in the case of kneaded direct-spun yarns, unlike a single-screw extrusion kneader, in a biaxial extrusion kneader, foaming induced in the kneader is difficult to escape to the charging side, so that the foam is mixed into the fiber and the yarn Cutting may occur frequently. For this reason, in particular, when a high viscosity polymer such as high molecular weight polyester is used as the matrix polymer, it is preferable to perform an operation of venting on the discharge side of the biaxial extrusion kneader to remove bubbles. In addition, it is preferable to vent when a piece of gut frequently occurs in the case of master pelletization. Further, in the present invention, due to the good fluidization effect due to the addition of the dendritic polyester, the screw torque is reduced at the same temperature as compared with the case where it is not added, so that the kneading temperature can be lowered. As a result, thermal decomposition, thermal denaturation, hydrolysis and the like of the polymer can be suppressed, and the high molecular weight and easy processability inherent to the virgin polymer can be easily utilized.

  In the case of resin processing, mechanical properties (such as improved elastic modulus) and gas barrier properties are often improved by mixing a large amount of inorganic filler such as glass fiber, but in the case of fiberization, inorganic filler is mixed. In such a case, the filter in the spinning machine may be clogged and the filtration pressure may increase rapidly, or the spinneret hole may be clogged with inorganic fillers and spinning may become impossible. Even if spinning is not possible, the discharge of the polymer from the spinneret hole is not stable, and problems such as frequent thread breakage and deterioration of yarn unevenness may occur. For this reason, in the case of fiberization, unlike resin processing, it is better not to mix the inorganic filler, and even if mixed, it is less than 0.5 wt% with respect to the entire blend polymer. When the inorganic filler is mixed in an amount of 0.5 wt% or more, U% cannot be 5% or less. The term “inorganic filler” as used herein means that 80 wt% or more is composed of an inorganic substance, the average diameter in terms of circle is 10 nm or more, and the average length is 100 nm or more.

  When master pelletized with the above dendritic polyester blend, it is diluted with a virgin polymer in the spinning process, but at this time, it is preferable to use a biaxial extrusion kneader from the viewpoint of uniformity of bun-lend. This is because, in the present invention, the degree of good fluidization effect varies depending on the dendritic polyester blend ratio, so if the blend is not uniform in the polymer blend, screw torque, tip pressure, filtration pressure, back pressure of the base, and spinning stress This is because spots such as the above occur and stable spinning may become impossible. When a uniaxial extrusion kneader is unavoidably used, a kneading function such as dull mage is added, and a static kneader is provided near the discharge of the uniaxial extrusion kneader or in the spinning machine or spinning pack to sufficiently homogenize the blend. preferable.

  As described above, because of the good fluidization effect due to the dendritic polyester blend, the kneader temperature can be lowered compared to the case where it is not added, but the set temperature can also be lowered for the spinning machine, for example, Even when the spinning temperature must be significantly higher than the melting point due to the high viscosity due to the high molecular weight polymer, it can be lowered to 5 ° C. or more by addition of dendritic polyester. This effect is more pronounced with higher viscosity polymers. In addition, the good fluidization effect stabilizes the discharge of the polymer from the spinneret hole, and the yarn unevenness can be reduced even in high-viscosity polymer spinning in which spinning is inherently unstable and yarn unevenness is likely to occur.

  In addition, the dendritic polymer used in the present invention is composed of an aromatic component in the branch structure, and is improved in rigidity, preferably exhibiting liquid crystallinity. As a result, the spinnability is improved, and high-speed spinning, which has been difficult with conventional hyperbranched polymer addition, becomes possible. This is also an effect peculiar to the elongation deformation field called spinning.

  In the present invention, the spinning temperature is preferably lowered by 5 to 20 ° C. as compared with the case where no dendritic polyester is added. More preferably, it is a 7-15 degreeC fall.

  The spinning speed varies depending on the physical properties of the matrix polymer and the purpose of the fiber, but can be about 500 to 6000 m / min. In particular, when the fiber for industrial material has excellent mechanical properties, it is preferable to use a high molecular weight polymer, set to 500 to 2000 m / min, and then stretch at a high magnification.

  In stretching, it is preferable to set the stretching temperature appropriately. This is because the dendritic polyester used in the present invention may have a softening temperature such as a glass transition temperature higher than 70 ° C. For example, at about 85 to 95 ° C, which is a normal stretching temperature of PET, the dendritic polyester is in the stretching process. As a result of acting as a foreign object, the toughness of the drawn yarn may be reduced. This effect is particularly prominent as the film is stretched at a high magnification. For this reason, even if the addition amount of dendritic polyester is trace amount, it is preferable to set extending | stretching temperature more than the glass transition temperature and softening temperature of dendritic polyester. However, when the drawing temperature is excessively increased, the yarn path may not be disturbed due to the spontaneous elongation of the fiber during the preheating process. For this reason, in order to improve the passability of the drawing process and to improve the mechanical properties of the obtained drawn yarn, for example, a drawing machine equipped with one or more pairs of heating rollers as shown in FIG. It is preferable to perform stretching in two or more stages. In this case, the first heating roller and the second heating roller set to be higher than the softening point of the matrix polymer are stretched at a magnification higher than the natural stretching ratio, and the molecular chain is somewhat ordered, and then the second heating roller temperature is set. By setting the dendritic polymer to a softening point or more and performing substantial stretching, the behavior of the dendritic polyester as a foreign substance is suppressed, the permeability in the stretching process is good, and excellent mechanical properties can be obtained.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, the measuring method in an Example used the following method.

A. Absolute molecular weight The absolute molecular weight of dendritic polyester is GPC-MALLS (gel permeation chromatograph (Shodex GPC-101) -light scattering detector (DAWN HELEOS made by Wyatt) using a solvent in which dendritic polyester is soluble. )), The sample concentration was 0.04%, and the measurement temperature was 23 ° C.

B. Weight average molecular weight The weight average molecular weight of the thermoplastic matrix polymer of the present invention is a value in terms of standard PMMA measured by gel permeation chromatography (GPC). The GPC measurement was performed using a WATERS differential refractometer WATERS410 as a detector, a pump using MODEL510 high performance liquid chromatography, and a solvent using hexafluoroisopropanol.

  However, the weight average molecular weight of polylactic acid was determined as follows. THF (tetrohydrofuran) was mixed with the sample chloroform solution to obtain a measurement solution. This was measured at 25 degreeC using GPC WATERS2690 by WATERS, and the weight average molecular weight was calculated | required in polystyrene conversion.

C. Intrinsic Viscosity of Polyester The intrinsic viscosity of polyester was dissolved in o-chlorophenol and measured at 25 ° C. using an Ostwald viscometer.

D. Chemical composition ratio of dendritic polyester The chemical composition ratio of dendritic polyester is dissolved in a mixed solvent of pentafluorophenol / deuterated chloroform (50/50) using a nuclear magnetic resonance apparatus (JNM-AL400 manufactured by JEOL). 1H-NMR measurement was performed at 40 ° C., and the chemical composition ratio of each component was calculated from the peak intensity ratio.

E. Melting point and glass transition point Using a DS Instruments 2SC Modulated DSC manufactured by TA Instruments, the peak top temperature indicating the melting of the polymer at 2nd run was taken as the melting point of the polymer. The temperature rising rate at this time was 16 ° C./min, and the sample amount was 10 mg.
Similarly, the midpoint of the region showing stepwise endotherm at 2nd run was taken as the glass transition point.

F. Liquid crystal starting temperature The temperature at which the entire field of view starts to flow as measured with a shear stress heating device (CSS-450) at a shear rate of 1.0 (1 / second), a heating rate of 5.0 ° C./min, and an objective lens 60 times. It was.

G. Single-Fine Fineness The fiber was made into a 100 m small wrinkle with a measuring machine, and its weight was multiplied by 100 to obtain the total fineness. The single yarn fineness was calculated by dividing the total fineness by the number of filaments.

H. Fiber mechanical properties (strength, elongation, elastic modulus)
In the case of an undrawn yarn at room temperature (25 ° C.), the initial sample length = 50 mm, the pulling speed = 400 mm / min, and in the case of the drawn yarn, the initial sample length = 200 mm and the pulling speed = 200 mm / min, which are shown in JIS L1013. A stress-strain curve was obtained under the conditions. The natural stretching ratio and the breaking elongation were read from the obtained stress-strain curve, and the NDR ratio was calculated according to the following formula. The strength and elongation were the stress and strain at break, respectively, and the elastic modulus was obtained from the slope of a linear approximation of the initial rising portion of the stress-strain curve.

I. Worcester spots on fibers (U%)
Measurement was performed in a normal mode at a yarn feeding speed of 200 m / min using a USTER TESTER 4 manufactured by Zerbegger Worcester.

J. et al. Total amount of carboxyl end groups of fiber A precisely weighed sample was dissolved in an o-cresol (5% water content) adjustment solution, an appropriate amount of dichloromethane was added to this solution, and then titrated with a 0.02 N KOH methanol solution. It was measured.

Reference Example 1 (Synthesis of Dendritic Polyester A-1)
In a reaction vessel equipped with a stirring blade and a distillation pipe, 40.3 g (0.292 mol) of p-hydroxybenzoic acid, 20.3 g (0.108 mol) of 6-hydroxy-2-naphthoic acid, 4,4-dihydroxy While charging 21.3 g (0.114 mol) of biphenyl, 36.0 g (0.171 mol) of trimesic acid and 70.6 g of acetic anhydride (1.10 equivalents of the total phenolic hydroxyl groups), stirring under a nitrogen gas atmosphere After reacting at 145 ° C. for 1.5 hours, the temperature was raised to 280 ° C. and stirred for 3 hours. When 91% of the theoretical distillation amount of acetic acid was distilled, 12.6 g (0.103 mol) of benzoic acid was added. In addition, heating and stirring were stopped when 100% of the theoretical distillation amount of acetic acid was distilled off, and the contents were discharged into cold water.

  As a result of nuclear magnetic resonance spectrum analysis, this dendritic polyester resin (A-1) has a structure in which the R portion has a p-oxybenzoate unit and 6-oxy-2-naphthoate unit content p of 2.33, 4, The content q of 4′-dioxybiphenyl units was 0.66, p + q + r = 3, and the branch point, that is, the content of B was 25 mol% with respect to the total monomers constituting the dendritic polyester. It was. The obtained dendritic polyester resin had a melting point Tm of 155 ° C., a liquid crystal starting temperature of 138 ° C., and an absolute molecular weight of 2300.

Reference Example 2 (Synthesis of dendritic polyester A-2)
After dendritic polyester A-1 was dried at 110 ° C. for 5 hours using a dryer, it was pulverized using a blender, and the resulting dendritic polyester powder was used at 100 ° C. for 12 hours using a vacuum heat dryer. Heated to vacuum dry.

  The dried dendritic polyester powder (70 g) and ethyl orthoacetate (31.4 g, 0.194 mol) were charged into a 500 mL reaction vessel equipped with a stirring blade and heated to 200 ° C. After stirring at 200 ° C. for 20 minutes, the contents were discharged into cold water.

  The obtained dendritic polyester resin (A-2) had a melting point Tm of 149 ° C., a liquid crystal starting temperature of 132 ° C., and an absolute molecular weight of 2700.

Reference Example 3 (Synthesis of dendritic polyester A-3)
In a reaction vessel equipped with a stirring blade and a distillation tube, 53.4 g (0.387 mol) of p-hydroxybenzoic acid, 26.9 g (0.143 mol) of 6-hydroxy-2-naphthoic acid, 27 of α-resorcinic acid .2 g (0.177 mol) and acetic anhydride 99.2 g (1.10 equivalents of total phenolic hydroxyl groups) were added and reacted at 145 ° C. for 1.5 hours with stirring under a nitrogen gas atmosphere. And the mixture was stirred for 3 hours. When 85% of the theoretical distillation amount of acetic acid was distilled, 8.63 g (0.071 mol) of benzoic acid was added, and 100% of the theoretical distillation amount of acetic acid was distilled off. Then, heating and stirring were stopped, and the contents were discharged into cold water.

  As a result of nuclear magnetic resonance spectrum analysis, this dendritic polyester resin (A-3) has a structure in which the R portion has a p-oxybenzoate unit and 6-oxy-2-naphthoate unit content p of 3.00, p + q + r = 3, and the branch point, that is, the content of B was 25 mol% with respect to the total monomers constituting the dendritic polyester. The obtained dendritic polyester resin had a melting point Tm of 138 ° C., a liquid crystal starting temperature of 115 ° C., and an absolute molecular weight of 2600.

Reference Example 4 (Synthesis of dendritic polyester A-4)
After dendritic polyester A-3 was dried at 80 ° C. for 5 hours using a dryer, it was pulverized using a blender, and the resulting dendritic polyester powder was used at 80 ° C. for 12 hours using a vacuum heat dryer. Heated to vacuum dry.

  70 g of dried dendritic polyester powder and 26.0 g (0.160 mol) of ethyl orthoacetate were charged into a 500 mL reaction vessel equipped with a stirring blade and heated to 200 ° C. After stirring at 200 ° C. for 20 minutes, the contents were discharged into cold water.

  The obtained dendritic polyester resin (A-4) had a melting point Tm of 131 ° C., a liquid crystal starting temperature of 110 ° C., and an absolute molecular weight of 2900.

Reference Example 5 (Synthesis of Dendritic Polyester A-5)
In a reaction vessel equipped with a stirring blade and a distillation tube, 48.0 g (0.35 mol) of p-hydroxybenzoic acid, 30.9 g (0.17 mol) of 4,4′-dihydroxybiphenyl, 5.41 g of terephthalic acid ( 0.033 mol), 10.4 g (0.054 mol) of polyethylene terephthalate having an intrinsic viscosity of about 0.6 dl / g, 42.0 g (0.20 mol) of trimesic acid, and 76.3 g of phenolic anhydride (phenolic hydroxyl group) A total of 1.1 equivalents) was charged, and the mixture was allowed to react at 145 ° C. for 1.5 hours with stirring under a nitrogen gas atmosphere. After the reactor internal temperature reached 250 ° C., 14.7 g (0.12 mol) of benzoic acid was added and the temperature was raised to 280 ° C. When 100% of the theoretical distillation amount of acetic acid was distilled, heating and stirring were stopped, and the contents were discharged into cold water to obtain a dendritic polyester resin (A-1).

  As a result of nuclear magnetic resonance spectrum analysis, this dendritic polyester resin (A-5) was found to have a structure of R portion having a p-oxybenzoate unit content p of 2.0, 4,4′-dioxybiphenyl unit and ethylene oxide. The unit content q is 0.5, the terephthalate unit content r is 0.5, and p + q + r = 3. The branching point, that is, the B content is 25 with respect to the total monomers constituting the dendritic polyester. Mol%. The terminal structures were carboxylic acid and benzoic acid ester.

  The obtained dendritic polyester resin A-5 had a melting point Tm of 182 ° C., a liquid crystal starting temperature of 163 ° C., and an absolute molecular weight of 5,500.

Reference Example 6 (Synthesis of aliphatic hyperbranched polymer A-6)
An aliphatic hyperbranched polymer was synthesized according to JP 2005-513186 A.

Examples 1-4, Comparative Example 1
After the dendritic polyester (A-1) synthesized in Reference Example 1 and high molecular weight PET having an intrinsic viscosity of 1.11 dL / g (weight average molecular weight = 25,500) were dried, they were weighed separately and independently biaxial An extrusion kneader was charged. At this time, the amount of dendritic polyester added was 1 wt% with respect to the polymer blend. Venting was performed on the discharge side of the biaxial extrusion kneader to eliminate bubbles. The kneader and spinning temperature were set as shown in Table 1. After discharging with a metal nonwoven fabric with an absolute filtration diameter of 10 μm at a discharge rate of 42.3 g / min, spinning was performed from a die with a round hole of 24 holes (φ = 0.6 mm), and after passing through a cooling air zone of Uniflow, Refueled and wound up.

  First, the spinning speed was set to 500 m / min, and the fluidity improvement effect by adding dendritic polyester was confirmed. As is clear from the comparison between Examples 1 to 5 and Comparative Example 1, the addition of the dendritic polyester causes a significant decrease in the spin pack pressure, and the fluidity of the high molecular weight PET is improved. It was confirmed. Also, FIG. 2 plots the relationship between the spinning temperature and the spinning pack pressure. When compared with the same spinning pack pressure, the addition of 1 wt% dendritic polyester (Examples 1 to 5) can expect a spinning temperature lowering effect of 13 ° C. I understood it. As a precaution, the weight average molecular weight of PET was measured in Example 2 (addition of 1% by weight of dendritic polyester, spinning temperature of 295 ° C.), which was 19,400 and no addition of dendritic polyester (Comparative Example 1). It was the same value, and neither hydrolysis nor thermal decomposition was promoted by addition of dendritic polyester. The obtained fiber has an NDR ratio of 30% or more, and it can be seen that the inhibition of elongational deformation is suppressed.

Example 5
Furthermore, after drying Adeka Corporation ADEKA STAB AX-71, which is an aliphatic phosphate ester transesterification inhibitor, 0.1 wt% was added to the polymer blend, and the same as in Example 4 (spinning temperature 287 ° C.). When the spinning was carried out, a further noticeable decrease in the spinning pack pressure occurred, which was very effective in improving the fluidity (Table 1, FIG. 3).

Example 6
When the dendritic polyester (A-2) synthesized in Reference Example 2 was used and spinning was performed in the same manner as in Example 4 (spinning temperature 287 ° C.), the spinning pack pressure was 6.1 MPa, and A-1 of the present invention was It was found that the fluidity was excellent as in the case of using. Moreover, the NDR ratio of the obtained undrawn yarn was 49%, and it was found that the inhibition of elongation deformation was further improved.

Comparative Example 2
Using the dendritic polyester (A-3) synthesized in Reference Example 3 and spinning in the same manner as in Example 3, the spinning pack pressure was 6.9 MPa, which is slightly better than A-1 of the present invention. It was found that the fluidity was inferior. Moreover, the NDR ratio of the obtained undrawn yarn was 25%, and the entanglement of molecular chains increased due to the presence of aliphatic in the branched structure.

Examples 7-9
Next, various addition amounts of the dendritic polyester (A-1) were changed and spinning was performed in the same manner as in Example 4. As a result, an effect of improving fluidity according to the addition amount was obtained.

Examples 10 and 11
Next, the spinning speed was changed and spinning was carried out in the same manner as in Example 4. However, the spinning performance was good even when the spinning speed was increased.

Examples 12-16, Comparative Examples 3-5
The undrawn yarns obtained in Examples 2, 4, 6 and Comparative Example 2 were subjected to drawing / heat treatment experiments. At this time, a 3 hot roller type stretching machine as shown in FIG. 2 is used as a stretching machine, and a feed roller (non-heating), a first heating roller, a second heating roller, a third heating roller, and a delivery roller (non-heating). The yarn was drawn and heat-treated through the yarn. The first heating roller temperature (preheating temperature) is 90 ° C., the second heating roller temperature is 140 ° C., the third heating roller temperature is 230 ° C., and the draw ratio between the first heating roller and the second heating roller is 3.85. The stretching ratio between the second heating roller and the third heating roller was changed. Table 2 shows the total draw ratio from the feed roller to the delivery roller.

Examples 17-20
Except that the second heating roller temperature was 165 ° C., and the draw ratio between the first heating roller and the second heating roller was 4.2 times using the unstretched obtained in Example 6, all in accordance with Example 11. Carried out.

  Regarding Examples 12 to 20 and Comparative Examples 3 to 5, there was no problem in stretchability, and yarn breakage, fluff, etc. did not occur. Moreover, although the relationship between strength and elongation was plotted in FIG. 2, Examples 12 to 16 to which A-1 was added had a strength at 10% or more compared to Comparative Examples 3 to 5 to which A-5 was added. It was expensive. In addition, regarding Examples 17 to 20 in which the temperature of the second heating roller was increased, the strength per elongation was further improved.

Example 21
Using the dendritic polyester (A-3) synthesized in Reference Example 3 and performing spinning in the same manner as in Example 3, the spinning pack pressure was 5.4 MPa, and a good fluidization effect was confirmed. Further, the NDR ratio of the obtained undrawn yarn was 50%, and the inhibition of elongation deformation was greatly improved.
This was stretched and heat-treated in the same manner as in Example 19 at a second hot roller temperature of 165 ° C. and a total draw ratio of 5.6 times, strength = 7.8 cN / dtex, elongation = 18%, U% = 0.77. %, Elastic modulus = 125 cN / dtex, and total carboxyl end group amount = 48 eq / ton.

Example 22
When the dendritic polyester (A-4) synthesized in Reference Example 4 was used for spinning in the same manner as in Example 3, the spinning pack pressure was 5.5 MPa, and a good fluidization effect could be confirmed. Further, the NDR ratio of the obtained undrawn yarn was 50%, and the inhibition of elongation deformation was greatly improved.
This was stretched and heat-treated in the same manner as in Example 19 at a second hot roller temperature of 165 ° C. and a total draw ratio of 5.6 times, strength = 8.0 cN / dtex, elongation = 17%, U% = 0.78. %, Elastic modulus = 119 cN / dtex, and total carboxyl end group amount = 27 eq / ton.

Comparative Example 6
When spinning was performed in the same manner as in Example 11 using the aliphatic hyperbranched polymer (A-4) synthesized in Reference Example 4, the spinning pack pressure was 8.0 MPa, and A-1 and A-2 of the present invention. The good fluidization effect was small compared to the case of using. Further, the spinning property was not as good as in Example 6 because the spinning was not stable and the yarn breakage occurred frequently.

Example 23
Poly L-lactic acid (weight average molecular weight 190,000) having an optical purity of 99% was dried, blended and melt-spun as in Example 3. At this time, the kneader temperature was 220 ° C., the spinning temperature was 230 ° C., the discharge rate was 30 g / min, a nozzle with a hole diameter of 0.30 mm and 18 holes was used, and the spinning speed was 1000 m / min. The spinning pack pressure at this time was 14 MPa. Since the spinning temperature could be lowered below the temperature at which polylactic acid was significantly decomposed (240 ° C.), generation of decomposition gas could be suppressed. The NDR ratio of the obtained fiber was 30%.

Comparative Example 7
Melt spinning was carried out in the same manner as in Example 21 except that the dendritic polyester and the transesterification inhibitor were not added and the kneader temperature was 240 ° C and the spinning temperature was 245 ° C. The spinning pack pressure at this time was 17 MPa. Since the spinning temperature was higher than that of polylactic acid, the generation of decomposition gas was remarkable and the working environment was deteriorated.

Example 24
PEN having an intrinsic viscosity of 0.75 dL / g was dried, blended and melt-spun as in Example 3. At this time, the kneader temperature was 290 ° C., the spinning temperature was 290 ° C., the discharge rate was 20 g / min, the spinneret was φ0.60 mm, 10 holes, and the spinning speed was 1350 m / min. The spinning pack pressure at this time was 5.4 MPa, and the effect of improving fluidity could be confirmed. The NDR ratio of the obtained fiber was 30%. Comparative Example 8
Melt spinning was carried out in the same manner as in Example 22 except that the dendritic polyester and the transesterification inhibitor were not added and the kneader temperature was 295 ° C. and the spinning temperature was 300 ° C. The spinning pack pressure at this time was 6.8 MPa.

Diagram showing stress-strain curve of undrawn yarn Diagram showing stretching machine Diagram showing the relationship between spinning temperature and pack pressure Diagram showing the relationship between strength and elongation of drawn yarn

Explanation of symbols

1: primary yield point 2: secondary yield point 3: break point 4: undrawn yarn 5: feed roller 6: first heating roller 7: second heating roller 8: third heating roller 9: delivery roller 10 : Drawn yarn

Claims (8)

A structure unit comprising an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), and an aromatic dicarbonyl unit (R) and a trifunctional or higher functional organic residue (B), and containing B A fiber comprising a polymer blend obtained by blending a dendritic polyester having an amount in a range of 7.5 to 50 mol% with respect to all monomers constituting the dendritic polyester in a thermoplastic matrix polymer in an amount of 0.1 to 10 wt%. A fiber having an NDR ratio calculated by the following formula of 30% or more.
NDR ratio = natural stretch ratio / breaking elongation × 100 (%)   Containing a structural unit composed of an aromatic oxycarbonyl unit (P), an aromatic dioxy unit (Q), and an aromatic dicarbonyl unit (R) and a trifunctional or higher functional organic residue (B), and containing B A fiber comprising a polymer blend obtained by blending a dendritic polyester having an amount in a range of 7.5 to 50 mol% with respect to all monomers constituting the dendritic polyester in a thermoplastic matrix polymer in an amount of 0.1 to 10 wt%. A fiber having a strength of 5.0 cN / dtex or more.   The fiber according to claim 1 or 2, wherein the thermoplastic matrix polymer is polyester.   The fiber according to any one of claims 1 to 3, wherein the total carboxyl end group amount is less than 50 eq / ton.   The fiber according to any one of claims 1 to 4, wherein U% is 0.1 to 5% or less.   The fiber according to any one of claims 2 to 5, wherein the single yarn fineness is 1 to 15 dtex.   The fiber according to any one of claims 2 to 6, wherein the elastic modulus is 110 cN / dtex or more.   The fiber product which used the fiber of any one of Claims 1-7 for at least one part.

Images