JP4271594B2 - Ethylene-vinyl alcohol copolymer fiber - Google Patents

Description

  The present invention relates to a fiber which is made of an ethylene-vinyl alcohol copolymer having excellent hygroscopicity, has good dyeing processability and hot water resistance, and has excellent fiberizing processability.

Traditionally, synthetic fibers, such as polyester and polyamide, have excellent physical and chemical properties, and are widely used not only for clothing but also for industrial purposes. have.
However, since these synthetic fibers have low moisture absorption and water absorption, the actual situation is that entry into the field where moisture absorption and water absorption such as underwear, pants, sheets and towels are required is limited. In the case of polyester fibers, various proposals for improving moisture absorption and water absorption, which can be said to be the greatest defects, have been made. Specifically, a method of post-treating polyester fibers with a hydrophilization imparting agent, a method of imparting moisture absorption and water absorption by making the polyester fiber surface or fiber interior porous, and the like have been proposed.
However, all of these methods have a problem that moisture absorption and water absorption are insufficient, and performance imparted by washing deteriorates.

  In order to improve these problems in recent years, a saponified ethylene-vinyl acetate copolymer, a resin excellent in moisture absorption and water absorption, so-called ethylene-vinyl alcohol copolymer is combined with polyester, polyamide, etc. There are known methods for improving the low moisture absorption and water absorption of polyamide and polyester by making them into fibers (Japanese Examined Patent Publication Nos. 56-5846, 55-1372, 7-84681, etc.) .

  However, in the case of a method in which this ethylene-vinyl alcohol copolymer is combined with polyester, polyamide, or the like and made into a fiber, the ethylene-vinyl alcohol copolymer is inferior in hot water resistance. By sewing or using a steam iron, the ethylene-vinyl alcohol copolymer exposed on the surface is partially softened or slightly glued, resulting in a new problem that the texture as a woven or knitted fabric is cured. As a method for solving this problem, a method of acetalizing an ethylene-vinyl alcohol copolymer with a dialdehyde compound is disclosed in the above patent publication.

  However, since the acetalization treatment requires a separate process other than the current dyeing process, there is a problem of an increase in processing cost, and further, the acid resistance of the treatment apparatus by using a strong acid at a high concentration at the time of acetalization treatment. Problems, problems of deterioration of light resistance due to dye fading due to unreacted dialdehyde compound during acetalization treatment, problems of lack of natural fiber-like swelling, excessive heat treatment such as steam iron and transfer print There was a problem of softening and fine sticking of the ethylene-vinyl alcohol copolymer due to the above.

  As a method for solving such a problem, Japanese Patent Publication No. 7-84681 proposes a method of performing a crosslinking treatment using a mixture of a dialdehyde and a surfactant. However, this method has a problem with the degree of freedom in dye selection. According to the study by the present inventors, it is difficult to crosslink simultaneously with scouring with this technique. As a result, it is necessary to crosslink simultaneously with dyeing, and the selection of dyes is limited.

As a method for improving the hot water resistance of an ethylene-vinyl alcohol copolymer, JP-A-2003-171821 proposes a sea-island fiber made of a kneaded mixture of an ethylene-vinyl alcohol copolymer and a polyamide resin. ing. This fiber can easily impart heat resistance, hot water resistance, and dye resistance without losing the high hygroscopicity, oil resistance, and solvent resistance of the ethylene-vinyl alcohol copolymer. However, increasing the blending amount of polyamide to provide heat resistance, hot water resistance, and dyeing resistance at higher temperatures (the dyeing temperature increases in the same bath dyeing with polyester fibers, etc.) When both the vinyl alcohol copolymer and the polyamide-based resin react with each other, a gel is generated in the fiber, resulting in a new problem that the long-run property during fiber formation is inferior. Specifically, the clogging with the gel causes the pressure increase of the filter, and as a result, early replacement of the pack becomes necessary, and frequent occurrence of fluff and yarn breakage occurs.
From the above, further improvement of ethylene-vinyl alcohol copolymer fibers has been desired.

Japanese Patent Publication No.56-5846 Japanese Patent Publication No.55-1372 Japanese Examined Patent Publication No. 7-84681 JP 2003-171821 A

  The present invention overcomes the above-mentioned problems of the prior art and simplifies and lowers the cost of dyeing without increasing the inherent properties of the ethylene-vinyl alcohol copolymer resin. It is an object of the present invention to provide an ethylene-vinyl alcohol copolymer-based fiber having a good size and good dyeability and excellent fiberizing processability.

  The above-mentioned purpose is that the resin constituting the fiber is an ethylene-vinyl alcohol copolymer (A) having 25 to 70 mol% of ethylene units and a polyamino resin (B) in which at least a part of terminal amino groups are blocked. This is achieved by a fiber comprising a kneaded product and having a weight ratio of (A) :( B) of 55:45 to 90:10.

  Although the hot water resistance can be increased by adding a polyamide resin to the ethylene-vinyl alcohol copolymer (A), gelation occurs and the spinnability is inferior simply by adding the polyamide resin. In the present invention, the terminal amino group of the polyamide resin is blocked in order to prevent gelation.

In the present invention, the polyamide resin (B) is preferably a case where 30% or more of all terminals are blocked with a structural unit capable of forming a cyclic imide bond with an amino group. Further, the dispersion state of the polyamide resin (B) in the ethylene-vinyl alcohol copolymer (A) component is an island shape, and the size of one island is 1 nm to 300 nm, and the island is arranged in the fiber cross-sectional direction. A case where the number is 10 / μm ² or more is also preferable in the present invention. The polyamide resin (B) is at least one polyamide resin selected from the group consisting of nylon 6/12, nylon 6 and nylon 6,6, and at least a part of the terminal amino group is blocked. Some cases are also preferred in the present invention.

  It is also preferred that the structural unit of the cyclic imide bond formed with the amino group of the polyamide resin (B) is phthalimide or succinimide. Furthermore, the polyamide resin (B) is subjected to ring-opening polymerization of a polyamide-forming monomer mainly composed of one or both of caprolactam and lauryl lactam in the presence of a diamine having 4 to 20 carbon atoms, so that 75% of all terminals are obtained. A polyamide resin (C) mainly composed of one or both of caproamide and laurylamide having an amino group and a relative viscosity [ηr] of 2.0 to 7.0 is once produced and then obtained. It is also preferable that the polyamide resin (C) is reacted with a terminal blocking agent capable of forming a cyclic imide bond with the terminal amino group of the polyamide resin (C). It is also preferred that the end-capping agent is a cyclic acid anhydride, and particularly where the cyclic acid anhydride is either phthalic anhydride or succinic anhydride.

  The ethylene-vinyl alcohol copolymer (A) according to the present invention is a saponified polymer of an ethylene-vinyl acetate copolymer. The amount of ethylene contained in the polymer needs to be 25 to 70 mol%, preferably 30 to 55 mol%. If the ethylene content of the copolymer is higher than 70 mol%, that is, if the content of the vinyl alcohol component is low, the melting point of the resulting polymer is lowered, and a heat-resistant material that is satisfactory for practical use is obtained. I can't. In addition, the properties such as hydrophilicity are reduced due to the reduction of hydroxyl groups, and it becomes difficult to obtain the natural fiber-like texture having the desired hydrophilicity. On the other hand, from the viewpoint of the fiber structure, if the content of the vinyl alcohol component exceeds 75% and becomes too high, the melt spinnability deteriorates and the spinnability at the time of fiberization becomes poor, and at the time of spinning or stretching. Single yarn breakage and fluff increase.

  In particular, in the present invention, when the ethylene-vinyl alcohol copolymer (A) is spun, if the content of the vinyl alcohol component in the copolymer increases, the melting point by differential scanning calorimetry (DSC) measurement. The peak shifts to the high temperature side, and the polyamide resin (B) and blend spinnability are improved. On the other hand, the melt spinnability tends to decrease due to the low ethylene content. Accordingly, in consideration of blend spinning of the polyamide resin (B), it is necessary to use an ethylene-vinyl alcohol copolymer having an ethylene content of 25 to 70 mol%.

  In the present invention, in order to introduce a crosslinked structure into the fiber composed of the polymer having a hydroxyl group, it is important to mix the polyamide resin (B) with the copolymer at a ratio of 10 to 45% by weight. . Preferably it is the range of 15-40 weight%. When the amount is less than 10% by weight, the effect of addition cannot be obtained, and when the amount exceeds 45% by weight, a dispersion state contributing to the fiberization processability cannot be obtained, and in some cases, reversal of sea-island relations occurs. Dyeing processability and improved texture of the resulting fabric cannot be obtained.

  Cross-linked structure is mainly due to reaction of terminal carboxyl group of polyamide and -OH of ethylene-vinyl alcohol copolymer, reaction of terminal amino group of polyamide group and carboxyl group of ethylene-vinyl alcohol copolymer, etc. It is estimated that The degree of cross-linking is preferably such that heat resistance without sticking is obtained in boiling water at 95 ° C. to 125 ° C., and this is greatly influenced by the dispersion state of the polyamide. Since the dispersion state of the polyamide which is the island component is related to the reaction efficiency of the crosslinking reaction between the island surface and the sea component, it is preferably dispersed within a certain range. The presence of polyamide is effective in improving heat resistance without causing sticking between fibers or excessive shrinkage during high temperature dyeing, steam ironing, washing or drying.

  The type of polyamide-based resin (B) used in the present invention is not particularly limited. For example, polycaprolamide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), polyundecanamide (nylon) 11), polylaurin lactam (nylon 12), polyethylenediamine adipamide (nylon 2,6), polytetramethylene adipamide (nylon 4,6), polyhexamethylene adipamide (nylon 6,6), poly Hexamethylene sebamide (nylon 2,10), polyhexamethylene dodecamide (nylon 6,12), polyoctamethylene adipamide (nylon 8,6), polydecanomethylene adipamide (nylon 10,6) , Polydodecamethylene sebacamide (nylon 10, 8) or caprolactam / laurinlac Copolymer (nylon 6/12), caprolactam / ω-aminononanoic acid copolymer (nylon 6/9), caprolactam / hexamethylene adipate copolymer (nylon 6/6, 6), lauric lactam / hexamethylenediamine Adipate copolymer (nylon 12 / 6,6), hexamethylenediamine adipate / hexamethylenediamine sebacate copolymer (nylon 6,6 / 6,10), ethylenediamine adipate / hexamethylenediamine adipate copolymer (nylon 2 6/6, 6), caprolactam / hexamethylenediamine adipate / hexamethylenediamine sebacate copolymer (nylon 6, 6/6, 10), and the like. In the above nylon display, the numerical values before and after “,” indicate the carbon numbers of the dicarboxylic acid component and the diamine component constituting the polyamide, and “/” indicates between the polyamides indicated by the numerical values before and after. It represents a copolymer.

These polyamides, particularly nylon 6/12, may be converted to a polyamide having a polyether bond in a polymer chain by adding a polyether diamine and a dicarboxylic acid (such as dimer acid) at the time of condensation polymerization.
A metaxylylene group-containing polyamide resin is also effective. A mixed xylylenediamine containing metaxylylenediamine and 80% or less of the total amount of paraxylylenediamine, and an α, ω-aliphatic dicarboxylic acid having 6 to 10 carbon atoms. A polymer containing at least 70 mol% of a structural unit generated from an acid in the molecular chain is also preferred. Examples of these polymers include homopolymers such as polymetaxylylene adipamide, polymetaxylylene sebacamide, and the like, and metaxylylene / paraxylylene adipamide copolymers, metaxylylene / paraxylylene azelamide Copolymers such as copolymers and the like, as well as homopolymer or copolymer components and aliphatic diamines such as hexamethylenediamine, alicyclic diamines such as piperazine, para-bis- (2- Of aminodiamine) benzene, aromatic dicarboxylic acid such as terephthalic acid, lactam such as ε-caprolactam, ω-aminocarboxylic acid such as γ-aminoheptanoic acid, para-aminomethylbenzoic acid And a copolymer obtained by copolymerizing such an aromatic aminocarboxylic acid. In the copolymer, paraxylylenediamine is preferably 80% or less, more preferably 75% or less, based on the total xylylenediamine.
It is also desirable to include at least 70 mol% or more of structural units generated from xylylenediamine and aliphatic dicarboxylic acid in the molecular chain. These polymers may contain polymers such as nylon 6, nylon 6,6, nylon 6,10, nylon 11, nylon 12, nylon 6,12 and the like.

Furthermore, amorphous polyamides, that is, those having substantially no endothermic crystal melting peak in DSC measurement, are mainly used polycondensates of aliphatic diamines and aromatic dicarboxylic acids.
Examples of the aliphatic diamine include hexamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, 2-methylpentamethylene diamine, and bis- (4-aminohexyl) -methane. 2,2-bis- (4-aminohexyl) -isopropylidine, 1,4- (1,3) -diaminocyclohexane, 1,5-diaminopentane, 1,4-diaminobutane, 1,3-diaminopropane , And 2-ethyldiaminobutane. One or more of these diamines can be used at the same time. Of these, hexamethylenediamine, 2-methylpentanemethylenediamine, 1,5-diaminopentane, 1,4-diaminobutane, and 1,3-diaminopropane are preferably used.

  Examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, alkyl-substituted isophthalic acid, alkyl-substituted terephthalic acid, naphthalenedicarboxylic acid, and diphenyl ether dicarboxylic acid. One or more of these dicarboxylic acids can be used simultaneously. Of these, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, diphenyl ether dicarboxylic acid and the like are preferable in terms of thermoformability.

  Examples of amorphous polyamides include hexamethylenediamine-isophthalic acid polycondensate, hexamethylenediamine-isophthalic acid / terephthalic acid polycondensate, 2,2,4-trimethylhexamethylenediamine, and 2, Examples include 4,4-trimethylhexamethylenediamine-terephthalic acid polycondensate. Among them, a polycondensate of hexamethylenediamine-isophthalic acid / terephthalic acid having a molar ratio of isophthalic acid / terephthalic acid in the range of 60/40 to 95/5, particularly 65/35 to 90/10 is preferable. .

  The above resins are used alone or in combination of two or more. Among the above resins, nylon 6, nylon 12, nylon 6/12, metaxylylenediamine-containing nylon, amorphous nylon, etc. are spinnable as suitable polyamide resins. From the point of hot water resistance. Nylon 6, nylon 12, and nylon 6/12 are particularly preferable. The composition of 6 component and 12 component in nylon 6/12 is not particularly limited, but 12 component is preferably 60 mol% or less, more preferably 50 mol% or less.

  Furthermore, the polyamide resin (B) constituting the fiber of the present invention requires that at least a part of the terminal amino group is blocked from the viewpoint of the fiber forming process, and preferably the terminal amino group after the blocking treatment. This is a case where the group amount is 10 μeq / gram or less and 70% or more of all terminals are blocked with a structural unit capable of forming a cyclic imide bond with an amino group. The term “terminal amino group amount” as used herein refers to the terminal group concentration (equivalent) per weight of the polyamide resin obtained by dissolving the polyamide resin in phenol and titrating with 0.05N hydrochloric acid. In the resin composition after the blocking treatment of the present invention, the amount of terminal amino groups of the polyamide resin (B) is preferably 10 μequivalent / gram or less from the viewpoint of fiberizing process property, more preferably 7 μequivalent / gram or less, More preferably, it is a case of 4 μequivalent / gram or less.

  The structural unit capable of forming a cyclic imide bond with an amino group means a cyclic imide structure such as phthalimide, succinimide, glutarimide, 3-methylglutarimide, maleimide, dimethylmaleimide, trimellitimide, pyromelliticimide, and the present invention. It is preferable that 30% or more of all terminals of the polyamide resin (B) used in is blocked with this structural unit, more preferably 50% or more is blocked with this structural unit, more preferably 70% or more. More preferably, it is blocked with this structural unit. If the blockage rate is less than 30%, the fiber forming processability becomes poor, which causes pressure increase of the filter, fluff and yarn breakage, which is not preferable.

  A structural unit capable of forming a cyclic imide bond with an amino group can be imparted by using a cyclic acid anhydride. Examples of such cyclic acid anhydrides include succinic anhydride, phthalic anhydride, glutaric anhydride, 3-methylglutaric anhydride, maleic anhydride, dimethylmaleic anhydride, trimellitic anhydride, pyromellitic anhydride, etc. In view of reactivity with the terminal amino group of the polyamide resin or thermal stability of itself, it is particularly preferable to use phthalic anhydride or succinic anhydride.

  The relative viscosity [ηr] of these polyamide resins (B) used in the present invention is preferably 2.0 to 7.0, and more preferably 2.5 to 5.0. When [ηr] is less than 2.0, the fiberization processability is poor, and when [ηr] is more than 5.0, the melt viscosity is too high and dispersibility with respect to ethylene-vinyl alcohol is poor. It becomes worse and it becomes difficult to obtain desired hot water resistance.

  The polyamide-based resin (B) used in the present invention can be produced by an arbitrary manufacturing method. As described above, the polyamide-based resin (B) preferably has its terminal structure and molecular weight adjusted. It is preferable that a molecular weight regulator and a terminal regulator, that is, a cyclic acid anhydride are allowed to act in the production process. As a general production method, (1) a method of adjusting the degree of polymerization and terminal structure by adding a cyclic acid anhydride and a molecular weight regulator during polymerization of a polyamide resin, and (2) polymerization once using a molecular weight regulator. A method of adjusting the terminal structure by reacting the resulting polyamide resin with a cyclic acid anhydride can be mentioned.

  As described above, in the polyamide resin (B) used in the present invention, it is preferable that 30% or more of all terminals are blocked with a structural unit capable of forming a cyclic imide structure with an amino group. As a method for achieving the terminal blocking rate, it is particularly preferable to employ the following method as a method for producing the polyamide resin (B).

That is,
(I) A polyamide resin-forming monomer mainly composed of one or both of caprolamtam and lauryl lactam, and a diamine having 4 to 20 carbon atoms as a molecular weight regulator for adjusting the degree of polymerization described above are charged into the reactor.
(Ii) After performing melt polymerization in the range of 200 ° C. to 250 ° C. to obtain a polyamide resin (C) in which 75% or more, more preferably 85% or more of all terminals are amino groups,
(Iii) extruded as a strand and once obtained as a pellet,
(Iv) Next, a batch type reactor or a twin screw or single screw extruder is used to react and mix with a cyclic acid anhydride to obtain a polyamide resin (B) having a relative viscosity [ηr] of 2.0 to 7.0. Is the method.

  Examples of the diamine having 4 to 20 carbon atoms used as the molecular weight regulator include 1,4-butanediamine, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,12-dodecanediamine, cyclohexanediamine, cyclohexanedimethanamine, aliphatic diamine such as trimethylpentanediamine, alicyclic diamine such as piperazine, Aromatic diamines such as para-bis- (2-aminoethyl) benzene, para-xylylenediamine, meta-xylylenediamine can be exemplified. From the viewpoint of the boiling point and reactivity of itself, 1,5-pentamethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, meta-xylylenediamine, para-xylylenediamine have a molecular weight. It is most preferable in that adjustment accuracy is obtained and that a polyamide resin (C) in which 75% or more of all terminals are amino groups is easily obtained. A suitable amount of the diamine to be used is in the range of 0.1 to 5 mol% with respect to the polyamide resin-forming monomer.

  Furthermore, as the molecular weight regulator, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, capric acid, pelargonic acid, myristic acid, palmitic acid, stearic acid, which are used as the molecular weight regulator of polyamide resins, are used. Aliphatic monocarboxylic acids such as acids, oleic acid, linoleic acid, cycloaliphatic carboxylic acids, cycloaliphatic monocarboxylic acids such as methylcyclohexanecarboxylic acid, benzoic acid, toluic acid, ethyl benzoic acid, aromatics such as phenylacetic acid A group monocarboxylic acid may be used in combination with a part thereof.

  The polyamide resin (C) thus obtained can be reacted and mixed with a cyclic acid anhydride using a batch reactor or a twin-screw or single-screw extruder to obtain a polyamide resin (B). it can. What was mentioned above can be used for the cyclic acid anhydride here.

  The addition amount of the cyclic acid anhydride with respect to the polyamide resin (C) is preferably 75% or more of the total terminal of the polyamide resin, more preferably 85% or more. An amount corresponding to 0.95 to 3.0 equivalents is preferable, and a range of 1.0 to 2.0 equivalents is more preferable. If it is less than 0.95 equivalent, it is difficult to block 70% or more of all terminals of the polyamide resin (B) with the cyclic imide structural unit. This is not preferable because problems such as bleed-out of reactants are caused.

Furthermore, in the present invention, the polyamide resin (B) is dispersed in the ethylene-vinyl alcohol copolymer (A), and the dispersion state is such that the polyamide resin (B) has an island shape. The size of the islands is 1 nm to 300 nm, preferably 10 nm to 200 nm, and the number of islands is preferably 10 / μm ² or more. If the size of the island exceeds 300 nm, the fiberizing process becomes unstable, which is not preferable. If it is less than 1 nm, it is difficult to obtain the desired heat resistance. When the number of islands is less than 10 / μm ² , it is difficult to obtain heat resistance and is inappropriate. The upper limit of the number of islands is not particularly limited, but if it is too large, gelation will occur and spinning becomes impossible, and therefore it is more preferable that it is 1000 pieces / μm ² or less, and further 500 pieces / μm ² or less. . The size of islands and the number of islands can be adjusted by the type of polyamide, the viscosity balance between polyamide and eval, the blending amount of polyamide, and the like.

  In the present invention, a stabilizer such as a copper compound, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, and a plasticizer, as necessary, within a range that does not impair its purpose and effect. , Lubricants, crystallization rate retarders, aldehyde scavengers, cross-linking agents such as boric acid, inorganic fillers, inorganic desiccants, and other polymers that do not significantly degrade fiber performance should be added during the polymerization reaction or in subsequent steps. Can do.

  If necessary, fine particles having an average particle size of 0.01 μm or more and 5 μm or less can be added in an amount of 0.05% by weight or more and 10% by weight or less during the polymerization reaction or in a subsequent step. The kind of fine particles is not particularly limited, and for example, inert inorganic fine particles such as silica, alumina, titanium oxide, calcium carbonate, and barium sulfate can be added. These can be used alone or in combination of two or more. Good. In particular, inorganic fine particles having an average particle size of 0.02 μm or more and 1 μm or less are preferable, and spinnability and stretchability are improved.

  In order to produce the fiber of the present invention, the ethylene-vinyl alcohol copolymer (A) and the polyamide resin (B) are mixed using a chip blend or a chip feeder to form a screw having a high kneading effect. It is introduced into the melt extrusion spinning head by an extruder. As extrusion conditions at this time, the temperature is in the range from the melting point to plus 10 ° C., based on the higher melting point of the ethylene-vinyl alcohol copolymer (A) and the polyamide resin (B), and the residence time in the extruder. Is set in the range of 2 to 30 minutes.

The ethylene-vinyl alcohol copolymer (A) begins to decompose when it stays at a temperature of 260 ° C. or higher for a long time. Therefore, when mixing and spinning with a high melting point polyamide, the spinning head temperature should be kept at 240 to 290 ° C. preferable. In this case, when the melt spinning speed (melt spinning speed) is about 20 to 50 g / spinning hole 1 mm ² · min, a high-quality composite fiber can be obtained with good spinning processability. This is preferable.

The size and number of spinning holes in the spinneret, the shape of the spinning hole, etc. can be adjusted according to the single fiber fineness, total denier, cross-sectional shape, etc. of the target fiber, but the spinning hole (single hole) It is desirable to keep the size of about 0.018 to 0.07 mm ² . Depending on the spinning head temperature conditions, nozzle dirt accumulates around the hole in the spinneret and thread breakage occurs.Therefore, the nozzle hole outlet has a tapered shape, or the atmosphere under the nozzle is steam-sealed to provide oxygen. A blocking method is preferred.

  The fiber melt-spun by the above is once cooled to a temperature not higher than the glass transition temperature, preferably 10 ° C. or lower than the glass transition temperature. The cooling method or cooling device in this case may be any method or device that can cool the spun fiber to its glass transition temperature or lower, and is not particularly limited. It is preferable to provide a cooling air blowing device and to cool the glass fibers to below the glass transition temperature by blowing cooling air to the spun fibers.

  At that time, the cooling conditions such as the temperature and humidity of the cooling air, the cooling air blowing speed, and the cooling air blowing angle with respect to the spun fiber should be such that the composite fiber spun from the base does not shake the fiber. However, it is only necessary to be able to cool quickly and uniformly to the glass transition temperature or lower. Among them, the cooling air temperature is about 20-30 ° C., the cooling air humidity is 20-60%, and the cooling air blowing speed is about 0.4-1.0 m / sec. It is preferable to cool the spun fibers with the direction perpendicular to the spinning direction because high quality fibers can be obtained smoothly. In addition, when cooling is performed under the above-described conditions using a cooling air blowing cylinder, a cooling air blowing cylinder having a length of about 80 to 160 cm with a slight gap or no gap immediately below the spinneret. Is preferably arranged.

  In addition, the take-up speed varies depending on whether the winding process is performed once after winding, when the film is spun and stretched in one step of direct spinning, or when the film is wound as it is at a high speed without being stretched. It can be picked up in the range of 6000m / min. Even if it is less than 500 m / min, there is no possibility of spinning, but there is little meaning in terms of productivity. On the other hand, at high speeds exceeding 6000 m / min, fiber breakage tends to occur. In terms of productivity and production cost, and fibers that cause a crosslinking reaction as in the present invention, it is preferable to fiberize by a high-speed spinning method (drawing omitted) or a direct-spinning drawing method.

The fiber of the present invention preferably has a thickness in the range of 0.001 to 1000 dtex from the viewpoint of apparel use, more preferably 0.01 to 100 dtex, and more preferably 0.1 to 5 dtex.
The fiber of the present invention may be used alone or in combination with other fibers, for example, natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as rayon, cupra, tencel, and acetate, nylon, polyester, acrylic, polyolefin, and the like. It can be made into a fabric such as a woven fabric, a knitted fabric, and a non-woven fabric by blending, blending, intertwisting, and interwoven with synthetic fibers.

  The fiber of the present invention is excellent in fiber production process passability, dyeing process passability, iron resistance, and the like, and also has excellent moisture absorption / water absorption, dyeability, texture, and hot water resistance.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all by these Examples. In addition, the measured value in an Example is measured with the following method.

[Relative viscosity (dL / g)]
The polyamide resin was dissolved in 97% concentrated sulfuric acid to a concentration of 1 g / dL and measured at 25 ° C. using an Ubbelohde viscometer.

[Amount of terminal amino group (μ equivalent / g)]
The polyamide resin was dissolved in phenol and determined by titration with 0.05N hydrochloric acid, and the end group concentration per weight of the polyamide resin was indicated.

[Amount of terminal carboxylic acid (μ equivalent / g)]
The polyamide resin was dissolved in benzyl alcohol and titrated with a 0.05N aqueous potassium hydroxide solution, and the end group concentration per weight of the polyamide resin was indicated.

[Terminal imide structure amount (μ equivalent / g)]
The polyamide resin was dissolved in deuterated hexafluoroisopropanol, the peak area of methylene group hydrogen adjacent to the terminal imide structure was determined by JEOL 500 MHz-NMR, and converted to the terminal group concentration per weight of the polyamide resin.

[Terminal amino group ratio (%)]
The total amount of the terminal amino group amount and the terminal carboxylic acid amount was calculated, and the proportion (%) of the terminal amino group amount in the total amount was calculated.

[Terminal imide structure ratio (%)]
The total amount of the terminal amino group amount, the terminal carboxylic acid amount, and the terminal imide structure amount was calculated, and the ratio (%) of the terminal imide structure amount occupying it was determined.

[Fiberification process properties]
The evaluation was based on the occurrence of fluff and breakage when spinning 100 kg. As for the fiberizing process property, ○ and Δ were judged as acceptable lines.
○: Good with no fluff and breakage △: No breakage and slight fluff generation ×: Fluff, yarn breakage, filter pressurization is confirmed XX: Fluff, yarn breakage is remarkable Generation, sudden increase in filter pressure is confirmed

[Dispersion of islands]
Using a transmission electron microscope (H-800NA type manufactured by Hitachi, Ltd.), the cross-section of the fiber was magnified 100000 times and observed. The size of the islands means the average diameter because the islands are dispersed in the fibers in a substantially spherical shape.

[Texture after dyeing]
Dyeing is performed under the following staining conditions (staining condition 1 or staining condition 2). Evaluate the texture between fibers after dyeing.
○: soft and bulky texture ×: stuck and hardened

Staining condition 1:
Dye: Sumikaron Navy Blue SPH conc 5% owf
Disper TL (Meisei Chemical) 1g / l
Acetic acid (50%) 0.3cc / l
Bath ratio 1:50
105 ° C x 40 minutes reduction cleaning:
NaOH 2g / l
Na ₂ SO ₄ 2g / l
Amiradine D 2g / l
85 ° C x 20 minutes

Dyeing condition 2 (high temperature dyeing):
Dye: Sumikaron Navy Blue SPH conc 5% owf
Disper TL (Meisei Chemical) 1g / l
Acetic acid (50%) 0.3cc / l
Bath ratio 1:50
115 ° C x 40 minutes reduction cleaning
NaOH 2g / l
Na ₂ SO ₄ 2g / l
Amiradine D 2g / l
95 ° C x 20 minutes

Reference Example 1: Production of polyamide resin (B-1) In a 30 liter pressure-resistant reactor, ε-caprolactam (8 kg), ω-lauryl lactam (2 kg) as a polyamide monomer, and meta-xylylenediamine (35 g) as a molecular weight regulator Water (1.0 kg) was charged and heated to 240 ° C. with stirring to increase the pressure to 0.5 MPa. Thereafter, the pressure was released to normal pressure, and polymerization was carried out at 240 ° C. for 3 hours. When the polymerization was completed, the reaction product was discharged into a strand, cooled, solidified, and then cut into nylon 6/12 (weight ratio 80/20) resin pellets. The obtained pellets were treated with hot water at 95 ° C. and dried to obtain raw material polyamide C-1. The raw material polyamide C-1 has a relative viscosity of 2.8 dl / g, a terminal amino group amount of 47 microequivalent / g, and a terminal carboxylic acid group amount of 58 microequivalent / g. The percentage was 45%.
This polyamide C-1 (5 kg) was dry blended with phthalic anhydride (56 g), reacted and mixed at a temperature of 260 ° C. using a twin screw extruder, discharged into a strand, and cut to give a polyamide resin B- 1 was obtained. The relative viscosity of polyamide B-1 is 2.7 dl / g, and the terminal amino group amount, terminal carboxylic acid group amount, and terminal phthalimide group amount are 4 microequivalent / g, 60 microequivalent / g, and 45 microequivalent / g, respectively. The ratio of the cyclic phthalimide group in the total terminal amount was 41%. These results are shown in Table 1.

Reference Example 2: Production of polyamide resin (B-2) The same as Reference Example 1 except that the amount of the molecular weight modifier meta-xylylenediamine was changed to 75 g and the terminal modifier was changed to phthalic anhydride (101 g). Thus, raw material polyamide C-2 and polyamide resin B-2 were obtained. Table 1 shows the results of evaluating these relative viscosities and terminal structures.

Reference Example 3: Production of polyamide resin (B-3) In a 30 liter pressure-resistant reactor, ε-caprolactam (10 kg) as a polyamide monomer, 1,6-hexanediamine (82 g) as a molecular weight regulator, water (1.0 kg) Was heated to 260 ° C. with stirring and the pressure was increased to 0.5 MPa. Thereafter, the pressure was released to normal pressure, and polymerization was carried out at 260 ° C. for 3 hours. When the polymerization was completed, the reaction product was discharged in a strand form, cooled, solidified, and then cut into nylon 6 resin pellets. The obtained pellets were treated with hot water at 95 ° C. and dried to obtain raw material polyamide C-3. The raw material polyamide C-3 has a relative viscosity of 2.7 dl / g, a terminal amino group amount of 81 microequivalent / g, and a terminal carboxylic acid group amount of 16 microequivalent / g. The percentage was 84%.
This polyamide C-3 (5 kg) was dry blended with phthalic anhydride (80 g), reacted and mixed at a temperature of 260 ° C. using a twin screw extruder, discharged into a strand, and cut to give a polyamide resin B- 3 was obtained. Polyamide B-4 has a relative viscosity of 2.6 dl / g, and the terminal amino group amount, terminal carboxylic acid group amount, and terminal phthalimide group amount are 4 microequivalent / g, 20 microequivalent / g, and 77 microequivalent / g, respectively. The ratio of the cyclic phthalimide group in the total terminal amount was 76%. These results are shown in Table 1.

Example 1
Polyethylene resin (B-1) with an ethylene-vinyl alcohol copolymer (ethylene unit content 44 mol%, saponification degree 99.6%, melt index MI = 2160 g (190 ° C., load 5.5 g / 10 min)). ) Was melt-kneaded 20% by weight, discharged from a round nozzle under the condition of a die temperature of 260 ° C., wound around a heating roller at a speed of 1000 m / min, and then directly stretched at a speed of 3000 m / min, 83 dtex / 24 A multifilament filament was obtained. There was no particular problem with the fiber forming process. Next, a knitted fabric was prepared using the obtained fibers, dyeing and reduction washing were performed under the following conditions, and as a result of evaluation, both color development and texture were good (see Table 1). The cooling air conditions during spinning were a temperature of 20 ° C., a humidity of 30%, and a spraying speed of 0.5 / second.

Examples 2-5
Fiberization, knitting, as in Example 1, except that the ethylene unit content of the ethylene vinyl alcohol copolymer (A) and the type and addition amount of the polyamide resin (B) are changed as shown in Table 2. Staining was performed. In any case, there was no problem in the fiberizing process property, and the texture of the knitted fabric was good.

Comparative Examples 1 and 2
Fiberization, knitting, and dyeing treatment were performed in the same manner as in Example 1 except that the addition amount of the polyamide resin (B) was changed as shown in Table 2. When the amount of (B) added was 1% by weight, there was no problem in fiber formation, but the texture was hard because the crosslinking reaction with the ethylene-vinyl alcohol copolymer did not proceed. In addition, when the amount of (B) added was 70% by weight, the viscosity decreased greatly, and as a result, the fiberization processability was extremely poor, and the texture of the resulting knitted fabric had a lot of sliminess.

Comparative Examples 3 and 4
Fiberization, knitting, and dyeing treatment were performed in the same manner as in Example 1 except that the type and addition amount of the polyamide resin (B) were changed as shown in Table 2. The fiber processability was not particularly problematic. There was no problem with the texture of the knitted fabric obtained under the dyeing condition 1, but the knitted fabric obtained under the higher dyeing condition 2 had a hard texture.

Comparative Example 5
Fiberization, knitting, as in Example 1 except that the polyamide resin (B) is changed to Ube nylon 7024B (Ube Industries, Ltd., amine value 47, terminal imide structural unit 0%) which is not terminal-adjusted. Staining was performed. The texture was good, but in these, the terminal amino group did not have a terminal imide structure, and as a result, a large amount of fluff and yarn breakage occurred. Also, the pressure increase of the filter suddenly occurred, which was not satisfactory with respect to the fiberization processability.

The fiber of the present invention is excellent in fiber production process passability, dyeing process passability, iron resistance, etc., and also has excellent moisture absorption / water absorption, dyeability, texture, and hot water resistance. Ideal for underwear, shirts, blouses, children's clothing, sports clothing, sports shoes, gloves, hats, pajamas, yukata, sheets, duvet covers, pillowcases, towels, etc.

Claims (8)

  The resin constituting the fiber consists of a kneaded product of an ethylene-vinyl alcohol copolymer (A) having 25 to 70 mol% of ethylene units and a polyamide resin (B) in which at least a part of the terminal amino groups are blocked. And the weight ratio of (A) :( B) is 55: 45-90: 10, The fiber characterized by the above-mentioned.   The fiber according to claim 1, wherein the polyamide resin (B) is a resin in which 30% or more of all terminals are blocked with a structural unit capable of forming a cyclic imide bond with an amino group. The dispersion state of the polyamide resin (B) in the ethylene-vinyl alcohol copolymer (A) component is an island shape, the size of one island is 1 nm to 300 nm, and the number of islands is 10 in the fiber cross-sectional direction. The fiber according to claim 1, wherein the fiber is at least ² / μm ² . The polyamide resin (B) is at least one polyamide resin selected from the group consisting of nylon 6/12, nylon 6 and nylon 6,6, and at least a part of the terminal amino group is blocked. Item 4. The fiber according to any one of Items 1 to 3 .   The fiber according to claim 2, wherein the structural unit of the cyclic imide bond formed with the amino group of the polyamide resin (B) is phthalimide or succinimide.   The polyamide resin (B) undergoes ring-opening polymerization of a polyamide-forming monomer mainly composed of one or both of caprolactam and lauryl lactam in the presence of a diamine having 4 to 20 carbon atoms. A polyamide resin (C) mainly composed of one or both of caproamide and laurylamide having an amino group and a relative viscosity [ηr] of 2.0 to 7.0 is once produced, and then the terminal amino group and The fiber according to claim 1, which has been reacted with an end-capping agent capable of forming a cyclic imide bond.   The fiber according to claim 6, wherein the end-capping agent is a cyclic acid anhydride.   The fiber according to claim 7, wherein the cyclic acid anhydride is either phthalic anhydride or succinic anhydride.