JPS641583B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyester fibers.
More particularly, the present invention relates to a method for producing polyester fibers that have special pores and exhibit improved color depth and clarity when colored. Polyester is widely used as a synthetic fiber because it has many excellent properties. However, compared to natural fibers such as wool and silk, cellulose fibers such as rayon and acetate, and acrylic fibers, polyester fibers lack the depth of color when colored, resulting in inferior color development and clarity. There is. Conventionally, attempts have been made to improve dyes, chemically modify polyester, etc. in an attempt to overcome this drawback, but none of them have been sufficiently effective. In addition, methods have been proposed in which a transparent thin film is formed on the surface of polyester fibers, and a method in which plasma irradiation at 80 to 500 mA·sec/cm ² is applied to the surface of a woven or knitted fabric to form fine irregularities on the fiber surface. however,
Even with these methods, the effect of improving the depth of color is insufficient, and in addition, the transparent thin film formed on the fiber surface easily falls off when washed, etc., and its durability is insufficient. In the plasma irradiation method, unevenness does not occur on the surface of the fibers in the woven and knitted parts that are shadowed by the irradiated surface, so the smooth fiber surface does not become uneven due to the rolling of threads within the fiber structure that occurs during wear. There is a drawback that color spots appear. On the other hand, as a method for imparting irregularities to the surface of polyester fibers, fibers made of polyoxyethylene glycol or polyester blended with polyoxyethylene glycol and a sulfonic acid compound are treated with an alkaline aqueous solution to form wrinkles arranged in the fiber axis direction. A method for producing hygroscopic fibers in which micropores are formed on the surface of the fibers, or polyester fibers prepared by adding fine particles of an inert inorganic substance such as zinc oxide, calcium phosphate, etc. to a polyester reaction system are treated with an alkaline aqueous solution. A method for producing hygroscopic fibers has been proposed in which fine pores are formed by eluting inorganic fine particles. however,
In the fibers obtained by these methods, no effect of improving the depth of color is observed, and on the contrary, a decrease in visual density is observed. In other words, in these methods, if the treatment with the alkaline aqueous solution is not sufficient, no effect of improving the depth of color will be observed, and if the treatment with the alkaline aqueous solution is sufficient, it will not improve the depth of the color but will improve the depth of the color. Perhaps due to the diffused reflection of light by the pores, the visual density decreases, making it appear whitish even when dyed in a dark color.Furthermore, the strength of the resulting fibers decreases markedly and becomes easily fibrillated. It is not practical. In addition, fibers made of polyester containing inorganic fine particles such as silica with a particle size of 80 millimicrons or less are subjected to alkali weight reduction treatment, so that the fiber surface has a 0.2 to 0.7
A method has been proposed in which the depth of color is improved by providing irregular irregularities of microns and causing fine irregularities of 50 to 200 millimicrons to exist within these irregularities. However, even with this method, the effect of improving color depth is insufficient;
Moreover, due to the extremely complex shape of the unevenness, the unevenness is destroyed by external physical effects such as friction, and the destroyed part becomes significantly discolored or has a difference in gloss compared to other undamaged parts. They have the disadvantage that they easily form and even fibrillate. The inventors of the present invention have conducted intensive studies to produce polyester fibers with excellent color depth and clarity that do not have the above-mentioned defects. If inert inorganic ultrafine particles with an average primary particle size of 100 millimicrons or more or less than 100 millimicrons are used, secondary agglomeration may easily occur depending on the formulation, resulting in secondary agglomerated particles of 100 millimicrons or more. As a result, in each case, there are many particles of 100 millimicrons or more inside the polyester fiber, and therefore, by alkali reduction treatment, particles in the visible light wavelength range or larger order It was discovered that unevenness was formed on the fiber surface, reducing the effect of improving color depth and sharpness and making fibrillation resistance inferior. Based on this knowledge, further investigation revealed that the average primary By alkali-treating polyester fibers containing a specific amount of inert fine particles with a particle diameter of less than 100 millimicrons and a number of secondary agglomerated particles of 100 millimicrons or more below a specific level, visible light rays can be removed. We have discovered that polyester fibers can be obtained that have unevenness smaller than the wavelength of proposed. However, since the polyester fibers obtained in this way can only be dyed by high-pressure dyeing, it is desirable to modify them into easily dyeable types that can be dyed by normal pressure boiling. The present inventor has conducted various studies on methods for modifying the above-mentioned polyester fiber into an easily dyeable type, and has surprisingly found that by spinning the above-mentioned inert fine particle-containing polyester under specific conditions at high speed. The microporous polyester fiber obtained by forming an undrawn fiber with a special high-order microstructure, then drawing it to a specific magnification in an unheated state, and then applying an alkali treatment, can be used for the intended purpose. It has been found that in addition to a certain dyeing-facilitating effect, it also has the effect of further improving the depth and clarity of colors. The present invention was completed as a result of further studies based on this knowledge. (1) In the reaction system for producing polyester, which is the base material of fibers, (a) the following general formula (In the formula, R ¹ and R ² are hydrogen atoms or monovalent organic groups, X is hydrogen atoms, monovalent organic groups, or metals, m
indicates 0 or 1. ) and (b) an alkaline earth metal compound and/or a lithium compound, and the average primary particle diameter of the internal precipitation system is less than 100 millimicrons. ~5% by weight
The inert fine particles are secondary agglomerated particles defined below of 100 millimicrons or more in the fiber cross section.
A polyester fiber containing inert fine particles that does not contain 3 or more particles per 10 square microns, the birefringence Δn of the entire fiber is 0.07 to 0.14, the birefringence Δna of the amorphous region is 0.06 or less, and the crystallinity Xc is 30 %
The above undrawn polyester fibers are unheated.
At least 2% by weight of the fiber is drawn by a factor of 1.05 to 1.35 and then treated with alkali.
This is a method for producing polyester fiber, which is characterized by eluting. However, secondary agglomerated particles are particles in which the distance between the centers of adjacent primary particles is less than twice the diameter of the primary particles, as seen in an electron micrograph magnified to the extent that the primary particle diameter can be discerned. A group. According to the findings of the inventor's numerous studies,
The inert fine particles contained in the inert fine particle-containing polyester fiber referred to in the present invention must have an average primary particle diameter of less than 100 millimicrons, and the secondary agglomerated particles of 100 millimicrons or more must have a fiber cross section of 10 There shall be no more than 3 per square micron. When the average primary particle diameter is 100 millimicrons or more, or when there are three or more secondary agglomerated particles of 100 millimicrons or more per 10 square microns of fiber cross section, sufficient color can be obtained within a low alkali loss rate. Depth and clarity cannot be obtained, and conversely, if the alkali weight loss rate is increased in an attempt to obtain sufficient color depth and vividness or to create a good texture, the abrasion resistance and fibrillation resistance will deteriorate, making it impractical for practical use. cause problems. The average primary particle diameter is preferably in the range of 50 millimicrons or less, particularly preferably in the range of 30 millimicrons or less. Furthermore, the number of secondary agglomerated particles present per 10 square microns of fiber cross section is preferably less than 2, particularly preferably less than 1. The primary particle diameter as used in the present invention means the diameter of an imaginary sphere having the same volume as the primary particle. In addition, secondary agglomerated particles refer to a group of particles in which primary particles are close to each other at intervals smaller than the primary particle diameter, that is, the distance between the centers of adjacent primary particles is less than twice the primary particle diameter. , the maximum distance from end to end of the secondary agglomerated particles is defined as the size of the secondary agglomerated particles. Secondary agglomerated particles according to this definition can be observed using an electron micrograph magnified to such an extent that the primary particle size can be identified. The inert fine particles referred to in the present invention are represented by (a) the following general formula: [In the formula, R ¹ and R ² are hydrogen atoms or monovalent organic groups,
X represents a hydrogen atom, a monovalent organic group or a metal, and m represents 0 or 1. ] These are internally precipitated fine particles consisting of a phosphorus compound represented by (b) an alkaline earth metal compound and/or a lithium compound. The above-mentioned inert fine particles may be contained alone in the polyester fiber, or two or more types may be contained together. If the content of such inert fine particles is too small, the surface roughness of the final polyester fiber obtained will be insufficient and it will be difficult to see the effect of improving the depth and clarity of the color. The depth and sharpness increase, but if the amount is too large, the depth and sharpness of the color will no longer show any significant improvement, and instead the fibril resistance will deteriorate, and on top of that, spinning becomes extremely difficult and virtually impossible. This is the scope of implementation. Therefore, the content of inert fine particles needs to be in the range of 0.1 to 5% by weight.
Among these, a range of 0.3 to 3% by weight is preferred. The polyester in the present invention is a polyester having terephthalic acid as the main acid component and at least one type of glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol, and tetramethylene glycol as the main glycol component. The main target is It may also be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/or a part of the glycol component is replaced with the above-mentioned glycol other than the main component or other diol component. It may also be made of polyester. Examples of difunctional carboxylic acids other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid,
Diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, 5-
Examples include aromatic, aliphatic, and alicyclic difunctional carboxylic acids such as sodium sulfoisophthalic acid, adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid. In addition, examples of diol compounds other than the above-mentioned glycols include cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S.
Examples include aliphatic, alicyclic, and aromatic diol compounds such as, and polyoxyalkylene glycols. Such polyesters may be produced by any method. For example, in the case of polyethylene terephthalate, usually terephthalic acid and ethylene glycol are directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene glycol are transesterified. The first stage reaction is to react with terephthalic acid to produce a glycol ester and/or its low polymer, and the first stage reaction product is heated under reduced pressure until the desired degree of polymerization is achieved. It is produced by a second step of polycondensation reaction. In order to produce the inert fine particle-containing polyester referred to in the present invention, at any stage until the production of the polyester described above is completed, (a) 0.3 to 3 mol% of the following general formula [In the formula, R ¹ and R ² are hydrogen atoms or monovalent organic groups,
X represents a hydrogen atom, a monovalent organic group or a metal, and m represents 0 or 1. ] A phosphorus compound represented by (b) an alkaline earth metal compound and/or a lithium compound without reacting (a) and (b) in advance, and the total number of equivalents of the metals (a) and (b). 2.0 for the number of moles of phosphorus compound whose amount is (a)
A method is preferably employed in which the amount is added to be 3.2 times as much, and then the synthesis of the polyester is completed. The phosphorus compound used here has the following general formula It is a phosphorus compound represented by the formula, where R ¹ and R ²
is a hydrogen atom or a monovalent organic group. This monovalent organic group is specifically an alkyl group, an aryl group, an aralkyl group, or [-(CH ₂ ) _l O] _k R ³ (wherein R ³ is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, l is an integer of 2 or more, k is an integer of 1 or more), etc., and R ¹ and R ² may be the same or different. ^X is a hydrogen atom, a ^monovalent organic group, or ^a metal ^. As the metal, alkali metals and alkaline earth metals are particularly preferable, and among them, alkaline earth metals are particularly preferable. m is an integer of 0 or 1. Such phosphorus compounds include, for example, orthophosphoric acid,
Phosphoric acid triesters such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, phosphoric acid mono- and diesters such as methyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, phosphorous acid,
Phosphite triesters such as trimethyl phosphite, triethyl phosphite, tributyl phosphite, triphenyl phosphite, mono- and phosphorous acids such as methyl acid phosphite, ethyl acid phosphite, butyl acid phosphite Diester, a phosphorus compound obtained by reacting the above phosphorus compound with glycol and/or water, and further obtained by heating the above phosphorus compound and a predetermined amount of the corresponding metal compound in the presence of a solvent. One or more phosphorus compounds selected from phosphorus compounds and the like can be used. In addition, as a solvent when making the above-mentioned phosphorus compound and metal compound react, it is most preferable to use glycol used as a raw material for the target polyester. The metal compound selected from the group consisting of alkaline earth metal compounds and lithium compounds to be used in combination with the phosphorus compound is not particularly limited as long as it reacts with the phosphorus compound to form a metal salt insoluble in the polyester. For example, Mg, Ca, Sr,
Organic carboxylates such as Ba, Li acetates, oxalates, benzoates, phthalates, stearates, inorganic acids such as borates, sulfates, silicates, carbonates, bicarbonates. Examples include salts, halides such as chlorides, chelate compounds such as ethylenediaminetetraacetic acid complex salts, hydroxides, oxides, alcoholates such as methylates, ethylates, and glycolates, and phenolates. Particularly preferred are organic carboxylates, halides, chelate compounds, and alcoholates that are soluble in ethylene glycol, and among them, organic carboxylates are particularly preferred. The above alkaline earth metal compounds and lithium compounds may be used alone or in combination of two or more. When adding the above-mentioned phosphorus compounds and metal compounds, in order to give the final polyester fiber excellent color depth and friction durability,
It is necessary to specify the amount of the phosphorus compound used and the ratio of the amount of the metal compound used to the amount of the phosphorus compound used. That is, if the amount of the phosphorus compound used in the present invention is too small, the color depth of the final polyester fiber obtained will be insufficient. When the number increases, the depth of color no longer shows a significant improvement;
On the contrary, the friction durability deteriorates, and furthermore, it becomes difficult to obtain a polyester having a sufficient degree of polymerization and softening point, and furthermore, troubles such as frequent yarn breakage occur during spinning. Therefore, the amount of phosphorus compound added is 0.3 to the acid component that makes up the polyester.
should be in the range of ~3 mol%, especially 0.5-2
A mole % range is preferred. In addition, if the total number of equivalents of the metal contained in the phosphorus compound and the metal compound is less than 2.0 times the number of moles of the phosphorus compound, the color depth of the obtained polyester fiber will be insufficient, and The polycondensation rate decreases, making it difficult to obtain a polyester with a high degree of polymerization, and the softening point of the resulting polyester also decreases significantly. On the other hand, if this amount exceeds 3.2 times, coarse particles will be generated, and instead of improving the depth of color, the visual density will decrease. Therefore, the total number of equivalents of the metal in the phosphorus compound and the metal compound should be in the range of 2.0 to 3.2 times the number of moles of the phosphorus compound, and particularly preferably in the range of 2.0 to 3.0 times. . The phosphorus compound and metal compound need to be added to the polyester reaction system without reacting in advance. By doing so, the insoluble particles can be produced in the polyester in the form of uniform ultrafine particles. If the above-mentioned phosphorus compound and metal compound are reacted externally in advance to form insoluble particles and then added to the polyester reaction system, the dispersibility of the insoluble particles in the polyester will be poor and coarse agglomerated particles may be contained. Therefore, the effect of improving the color depth of the finally obtained polyester fiber is not recognized, which is not preferable. The above-mentioned phosphorus compound and metal compound can be added in any order at any stage until the production of the polyester is completed. However, if the phosphorus compound is added at a stage where the first stage reaction has not yet completed, the completion of the first stage reaction may be inhibited. If added, coarse particles may be generated during the esterification reaction, or the reaction may proceed abnormally quickly and cause bumping when the reaction is an transesterification reaction. It is preferable that the amount is about 20% by weight or less. The timing of addition of at least 80% by weight of the metal compound and the total amount of the phosphorus compound is determined at the first stage of the synthesis of the polyester.
It is preferable that the reaction is carried out after the stage in which the reaction of the stage has been substantially completed. Additionally, if the phosphorus compound and metal compound are added at a stage where the second stage reaction has progressed too much, particles tend to aggregate and coarsen, resulting in insufficient depth of color in the final polyester fiber. Therefore, it is preferable that the intrinsic viscosity of the reaction mixture in the second stage reaction reaches 0.3. The above-mentioned phosphorus compound and metal compound may be added all at once, added in two or more divided portions, or added continuously. Any catalyst can be used for the first stage reaction in polyester production, but some of the metal compounds mentioned above have the ability to catalyze the first stage reaction, particularly the transesterification reaction, and such compounds are used. In some cases, it is not necessary to use a separate catalyst, and this metal compound can be added before or during the first stage reaction to serve as a catalyst.
As mentioned above, it may cause bumping phenomenon, so the amount used should be 20% of the total amount of metal compound added.
It is preferable to keep it below % by weight. In this way, in the present invention, the fine particles used are
Because they are precipitated by the reaction between the specific phosphorus compound and the alkaline earth metal compound in the polyester production reaction system, they become extremely finely dispersed, and the secondary agglomerated particles of 100 millimicrons or more as defined above are Ten
Polyesters with substantially no polyesters, let alone more than 3 per square micron, are easily obtained. In the present invention, the undrawn polyester fiber is made of polyester containing inert fine particles as described above, and although the fiber as a whole has a fairly high degree of orientation and crystallinity, the amorphous region is extremely low. It uses fibers with a special microstructure that only has a certain orientation. That is, the fiber has birefringence Δn of the entire fiber, birefringence Δna of the amorphous region, and crystallinity Xc that satisfy all of the following conditions. △n...0.07-0.14 (preferably 0.08-0.13) Xc...30% or more (preferably 40% or more) △na...0.06 or less (preferably 0.01-0.04) Such undrawn fibers are It is easy to stretch in an unheated state, and by such stretching, fibers with excellent dyeability, level dyeability, and thermal and mechanical properties can be obtained. However, if the birefringence △n of the entire fiber is lower than 0.07, the amount of deformation of the molecular chains during stretching is large, and the distribution of stress acting on each molecular chain is also greatly expanded, resulting in poor stretchability in an unheated state. Stretching unevenness tends to occur even if the stretching temperature is increased using a preheating roller or the like. On the other hand, those with △n exceeding 0.14 are usually
Because it is necessary to spin at a speed higher than 7000m/min,
Not only does it require a special high-performance winding device, which increases equipment costs, but also in terms of quality, the uniformity of the denier decreases significantly due to air resistance, and especially in the case of fine denier yarn, yarn breakage occurs and the stability becomes unstable. Furthermore, if Δn is larger than 0.14, the stretching tension increases during stretching in an unheated state and the mechanical properties of the stretched fibers deteriorate. On the other hand, if the crystallinity Xc of the undrawn fiber is less than 30%, the drawn fiber obtained from this has a fine structure that can be called highly oriented amorphous and lacks stability against heat. It requires heat setting at temperatures of about 10.degree. In the present invention, in the undrawn fiber, in addition to the birefringence Δn and crystallinity Xc of the entire fiber, it is also important to
molecule) is important, and it is necessary that the birefringence Δna of the amorphous region is 0.06 or less. That is, if the orientational cohesion of the molecular chains distributed between the crystals is high, stretching will not only lead to the destruction of the crystals accompanied by the unfolding of many molecular chains, but also make stretching irregularities more likely to occur.
The need for heat setting arises again. In other words, only when crystals that are oriented and developed beyond a certain level are connected by amorphous materials with low restraint, can rearrangement without destroying the crystals by stretching at a low magnification without heating. It is possible to obtain polyester fibers that have excellent dyeability and leveling properties without the need for heat setting, and have the same thermal and mechanical properties as ordinary drawn and heat-treated yarns. Note that Δn, Δna, and Xc mentioned here are values measured by the following methods, respectively. (i) △n (birefringence): The refractive index (n⊥) for light polarized at right angles to the fiber axis and the refractive index (n⊥) for light polarized parallel to the fiber axis.
), that is, Δn=n−n⊥. It is measured by a conventional method using a polarizing microscope equipped with a Beretsk compensator. (However, tricresyl phosphate was used as the immersion liquid.) (ii) △na (birefringence of the amorphous region): A parameter that indicates the orientation of molecular chains in the amorphous region. It is calculated by the following formula using the birefringence Δn and the crystal orientation function fc (described in JP-A-50-59526). △na=△n−0.212fc・Xρ/1−X〓 However, Xρ=(0.7491−1/ρ)/0.06178 (iii) Xe (crystallinity) (010) of polyester filament that appears in the equator direction in X-ray diffraction The diffraction intensity of the surface is separated into Ic and Ia after correction for air scattering as shown in Fig. 1, and is determined by the following equation. {Ic/(Ic+Ia)}×100=Xc(%) (X-ray diffraction was performed using a Rigaku Corporation D-9C type device.
Measurement conditions were 35kV x 20mA, Ni-filter used, divergence slit 2mmφ, scattering slit 1°, receiving slit 0.3.
Let it be mm. ) In order to produce an undrawn polyester fiber containing inert fine particles having such a fine structure, the polyester containing inert fine particles is melted and discharged from a spinneret, and the discharged yarn is cooled and solidified, after which it is spun for 4,000 to 7,000 m/s.
A method in which the fibers are drawn at a speed of 4,500 to 6,000 m/min is preferable because the productivity and the uniformity of the undrawn fibers obtained are excellent. However, other methods include increasing the hole diameter of the spinneret to increase the spinning draft to 1000 or more and increasing the above-mentioned take-up speed to 3500 m/min or more. It is also possible to adopt a method such as cooling the material to the glass transition temperature, then uniformly reheating it to 120 to 180° C. using a heating tube, slit heater, heating roller, etc., and then taking it off at a speed of 3500 m/min or more. The fibers spun here may be solid fibers having no hollow portions or hollow fibers having hollow portions. Further, the outer shape and the shape of the hollow portion in the cross section of the fiber may be circular or irregular. Furthermore, even if it is a core-sheath type composite fiber consisting of a modified polyester containing the above-mentioned inert fine particles and an unmodified polyester that does not contain the inert fine particles, the modified polyester is a sheath component, and the unmodified polyester is a core component. A side-by-side type composite fiber having two or more layers of polyester and polyester may also be used. According to the present invention, such undrawn fibers are drawn 1.05 to 1.35 times, preferably 1.10 to 1.30 times in an unheated state. This stretching may be carried out in a separate process after melt-spinning and winding it into a package, but it is possible to reduce the equipment space by performing so-called spinning direct stretching, in which the spun fibers are continuously drawn without being wound up.
It is also possible to save labor. Typically, polyester undrawn fibers are drawn at a temperature higher than the glass transition temperature of polyester and further
The undrawn polyester fiber containing inert fine particles used in the present invention, which is heat set at a temperature of 130 to 200°C, has a special microstructure as described above, so it can be cold drawn with good drawing condition. Furthermore, by cold drawing, fibers with excellent dyeability and leveling properties and good dimensional stability can be obtained. (Therefore, conventional heat setting is not necessary.) However, when hot stretching is performed,
Not only is the easily dyeable fine structure formed during the spinning stage destroyed, resulting in a decrease in dyeability, but it is also difficult to heat the fibers completely uniformly, and the fibers are easily dyed due to slight temperature irregularities. Because staining spots occur, deterioration of level staining cannot be avoided. In addition, when the temperature of the roller rises above the glass transition temperature due to the heat of stretching, it is preferable to pass cooling water inside the roller to maintain the surface of the roller at around room temperature. The stretching ratio is
It needs to be 1.05 to 1.35 times (preferably 1.10 to 1.30 times). If the stretching ratio is less than 1.05, the stretching effect will be poor, and the mechanical properties (cutting strength, cutting elongation, primary yield point strength, etc.) will be inferior overall.
When the stretching ratio exceeds 1.35 times, not only the stretchability deteriorates but also the strength of the obtained fiber becomes extremely low. In order to remove a part of the polyester fiber containing inert fine particles obtained in this way, it may be subjected to strong twisting or false twisting as necessary, or after being made into a fabric, it may be treated with an aqueous solution of an alkaline compound. It can be done easily. The alkaline compounds used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate,
Examples include potassium carbonate. Among them, sodium hydroxide and potassium hydroxide are particularly preferred. The concentration of such an aqueous solution of an alkali compound varies depending on the type of alkali compound, processing conditions, etc., but is usually preferably in the range of 0.01 to 40% by weight, particularly
A range of 0.1 to 30% by weight is preferred. The processing time is preferably in the range of room temperature to 100°C, and the processing time is 1 minute to
It is usually carried out for a period of 4 hours. Further, the amount of the alkali compound eluted and removed by treatment with the aqueous solution should be in the range of 2% by weight or more based on the weight of the fiber. By treating with an aqueous solution of an alkaline compound in this way, irregularities smaller than the wavelength of visible light can be uniformly formed over the entire surface of the fiber, and the special high-order fine structure inside the fiber as described above can be created. The resulting microporous polyester fibers exhibit improved color depth and clarity when dyed compared to similar microporous polyester fibers with conventional microstructures. Note that the polyester fiber obtained by the method of the present invention may contain optional additives such as catalysts, color inhibitors, heat resistant agents, flame retardants, fluorescent brighteners, matting agents, colorants, etc. as necessary. May be included. Further explanation will be given below with reference to Examples. Parts and % in Examples indicate parts by weight and % by weight, and the depth of color and friction discoloration resistance when dyeing the obtained polyester fibers were measured by the following method. (i) Depth of color Bathochromaticity (K/
S) was used. This value is determined by measuring the spectral reflectance (R) of the sample cloth using a Shimadzu RC-330 self-recording spectrophotometer and using the KubelKa-Munk equation shown below. The larger this value is, the greater the deep color effect is. K/S=(1-R) ² /2R (measurement wavelength 500 mμ) In addition, K shows an absorption coefficient and S shows a scattering coefficient. (ii) Discoloration resistance by abrasion Using a Gakushin type plane abrasion machine for friction fastness testing, the test cloth was abraded a specified number of times under a load of 500g using a dioset made of 100% polyethylene terephthalate as the friction cloth. ,
The degree of discoloration was determined using a gray scale for discoloration. The case where the wear resistance was extremely low was rated as 1st grade, and the case where it was extremely high was rated as 5th grade. For practical purposes, level 4 or above is required. Example 1 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, and 0.06 parts of calcium acetate monohydrate (0.066 mol% relative to dimethyl terephthalate) were charged into a transesterification tank, and heated from 140°C over 4 hours under a nitrogen gas atmosphere. The transesterification reaction was carried out while raising the temperature to 230°C and distilling the generated methanol out of the system. Subsequently, 0.5 parts of trimethyl phosphate (0.693 mol % based on dimethyl terephthalate) and 0.31 parts of calcium acetate were added to the obtained reaction product in advance.
Water salt (1/2 mole relative to trimethyl phosphate)
To 9.31 parts of a clear solution of calcium acetate monohydrate (trimethyl phosphate) was added to 9.31 parts of a clear solution of diester calcium phosphate prepared by reacting 8.5 parts of ethylene glycol at 120°C for 60 minutes under total reflux. 9.88 parts of a mixed transparent solution of diester calcium phosphate salt and calcium acetate obtained by dissolving 0.9 times the mole of phosphoric acid diester calcium salt and calcium acetate were added thereto, and then 0.04 part of antimony trioxide was added and the mixture was transferred to a polymerization vessel.
Next, the pressure was reduced from 760 mmHg to 1 mmHg over 1 hour, and at the same time the temperature was raised from 230°C to 285°C over 1 hour and 30 minutes. Under reduced pressure of 1 mmHg or less, polymerization temperature 285
Polymerization was carried out for an additional 3 hours at 100°C for a total of 4 hours and 30 minutes to obtain a polymer having an intrinsic viscosity of 0.638, a softening point of 258°C, and containing 0.6% of inert fine particles. After the reaction was completed, the polymer was made into chips according to a conventional method. The chips were dried by a conventional method, melted and discharged through a spinneret with 24 circular spinning holes with a hole diameter of 0.3 mm at a spinning temperature of 285°C, and a wind speed of 0.25 m/min directly below the spinneret.
Cooled and solidified with cooling air for 2 seconds, then 4500m/
Taken off at a speed of 1 minute, wound onto a bobbin, 95 denier, cutting elongation 81%, primary yield strength 0.93 g/de.
An undrawn yarn with Xc of 40%, Δn 0.075, and Δna 0.028 was obtained. Next, this undrawn yarn is stretched at a drawing ratio without heating.
It was drawn at a factor of 1.27 to obtain a drawn yarn with a denier of 75, elongation at break of 30%, and shrinkage in boiling water of 8%. This drawn yarn (warp) has a twist number of 300T/M and a density of 40.
It was woven into a plain weave with a thread/cm, (weft) 0T/M, and a density of 40 threads/cm. After presetting the obtained gray fabric using a conventional method, 1%
The fabric was treated with an aqueous sodium hydroxide solution at boiling temperature to obtain a fabric with a weight loss rate of 20%. After dyeing this fabric with Dianix Black HG-FS (Mitsubishi Chemical Industries, Ltd. product) 15% owf at 130℃ for 60 minutes,
A black dyed cloth was obtained by reduction washing in an aqueous solution containing 1 g/l of sodium hydroxide and 1 g/l of hydrosulfite at 70°C for 20 minutes. The color depth and friction discoloration resistance of this black dyed fabric after 200 abrasions were as shown in Table 1. Example 2 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, and 0.06 parts of calcium acetate monohydrate were placed in a transesterification tank, and the temperature was raised from 140°C to 230°C over 4 hours in a nitrogen gas atmosphere to produce methanol. The transesterification reaction was carried out while distilling it out of the system. Subsequently, 0.64 parts of lithium acetate anhydrous (relative to dimethyl terephthalate) was added to the resulting reactant.
After 5 minutes, 0.35 part of orthophosphoric acid (0.69 mol% relative to dimethyl terephthalate) was added, and after another 5 minutes, 0.04 part of antimony trioxide was added.
0.04 part was added and transferred to a polymerization can. Next, 3,5-di(β-
4.6 parts of sodium hydroxyethoxycarbonyl)benzenesulfonate (2.5 mole % based on dimethyl terephthalate) was added to the polymerization kettle. Next, the pressure was reduced from 760 mmHg to 1 mmHg over an hour.
At the same time, the temperature was raised from 230°C to 280°C over 1 hour and 30 minutes. Polymerization was carried out for an additional 2 hours and 30 minutes at a polymerization temperature of 280℃ under reduced pressure of 1 mmHg or less, for a total of 4 hours, and the intrinsic viscosity
A polymer with a softening point of 0.512 and a softening point of 258°C was obtained. Using this polymer, high-speed spinning, cold stretching, weaving, presetting, and alkali treatment were carried out in the same manner as in Example 1 to obtain a plain woven fabric with a weight loss rate of 20%. The fabric after this alkali treatment is Aizen Cathilon.
Black CD-GLH (Hodogaya Chemical Co., Ltd. product) 8% owf
After dyeing at 120° C. for 60 minutes in a dye bath containing 2 g of Glauber's salt, a black dyed cloth was obtained by soaping according to a conventional method. The color depth and friction discoloration resistance of this black dyed fabric after 200 abrasions were as shown in Table 1. In addition, the undrawn yarn obtained here has Xc of 37% and △
It had a fine structure of n0.078 and △na0.025. Comparative Example 1 Example 1 except that instead of the high-speed spinning and cold stretching carried out in Example 1, ordinary spinning at a take-up speed of 1100 m/min and ordinary stretching at a stretching temperature of 85°C and a draw ratio of 3.5 times were carried out. Do the same as 75 denier /
A drawn yarn of 24 filaments was obtained, and the same procedure as in Example 1 was carried out to obtain a black dyed cloth with a weight loss rate of 20%. The results were as shown in Table 1. Comparative Example 2 Same as Example 2, except that instead of the high-speed spinning and cold stretching carried out in Example 2, ordinary spinning at a take-up speed of 1100 m/min and ordinary stretching at a stretching temperature of 85°C and a draw ratio of 3.5 times were carried out. Do the same 75 denier/24
A drawn filament yarn was obtained, and the same procedure as in Example 2 was carried out to obtain a black dyed cloth with a weight loss rate of 20%. The results were as shown in Table 1. Example 3 The dyeing conditions used for dyeing the alkali weight loss treated fabric in Example 1 were 130°C for 60 minutes.
The same procedure as in Example 1 was carried out except that the temperature was changed to 60 minutes. The results are shown in Table 1. Comparative Example 3 The dyeing conditions used for dyeing the alkali weight loss treated fabric in Comparative Example 1 were 130°C for 60 minutes.
The same procedure as in Comparative Example 1 was conducted except that the temperature was changed to 60 minutes. The results are shown in Table 1. Comparative Example 4 An aqueous silica sol with an average single particle diameter of 10 millimicrons and a concentration of 20% by weight was mixed with ethylene glycol at room temperature, thoroughly stirred, mixed with terephthalic acid, and then directly polymerized to produce silica with an intrinsic viscosity of 0.67. Polyethylene terephthalate containing 0.5% by weight was obtained. Using the obtained polyethylene terephthalate, chips were dried in the same manner as in Example 3.
Spinning, stretching, weaving, presetting, alkali weight loss (weight loss rate 20%), dyeing (100°C, 60 minutes), and reduction washing were performed. The results are shown in Table 1.

【table】

【table】 [Brief explanation of drawings]

FIG. 1 is an X-ray diffraction intensity curve for explaining the method of measuring crystallinity Xc, where Ic indicates the diffraction intensity due to crystals, and Ia indicates the diffraction intensity due to amorphous crystals.

Claims (1)

[Scope of Claims] 1. In the reaction system for producing polyester as the base of fibers, (a) 0.3 to 3 mol% of the following general formula based on the acid component constituting the polyester. (In the formula, R ¹ and R ² are hydrogen atoms or monovalent organic groups,
X represents a hydrogen atom, a monovalent organic group or a metal, and m represents 0 or 1. ) and (b) an alkaline earth metal compound and/or a lithium compound.
The average primary particle diameter of the internal precipitation system precipitated by reacting the amount such that the total number of equivalents of metals (a) and (b) is 2.0 to 3.2 times the number of moles of (a) is 100 Contains 0.1 to 5% by weight of inert fine particles of less than millimicrons, and the inert fine particles have secondary agglomerated particles of 100 millimicrons or more as defined below in the fiber cross section.
A polyester fiber containing inert fine particles that does not contain 3 or more particles per 10 square microns, the birefringence △n of the entire fiber is 0.07 to 0.14, and the birefringence △ of the amorphous region
Undrawn polyester fibers with na of 0.06 or less and crystallinity Xc of 30% or more are 1.05 to 1.35 in an unheated state.
1. A method for producing polyester fibers, which comprises stretching the fibers twice and then treating them with an alkali to elute at least 2% by weight of the fibers. However, secondary agglomerated particles are particles in which the distance between the centers of adjacent primary particles is less than twice the diameter of the primary particles, as seen in an electron micrograph magnified to the extent that the primary particle diameter can be discerned. A group.