JPH0160598B2 - - 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 porous polyester fibers having special micropores and exhibiting 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 method of applying plasma irradiation, unevenness does not occur on the surface of the fiber in the part of the fiber that will be in the shadow of the irradiated surface, so the smooth fiber surface does not appear on the surface due to the rolling of threads within the fiber structure that occurs during wear. It has the disadvantage of causing color spots. 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. That is, in these methods, if the treatment with the alkaline aqueous solution is not sufficient, no effect of improving the color depth is observed at all, and when the treatment with the alkaline aqueous solution is sufficient, the color depth is not improved, The visual density decreases, probably due to the diffuse reflection of light by the micropores.
Even if the fibers are dyed in a deep color, they look whitish, and furthermore, the strength of the obtained fibers is significantly reduced and they become easily fibrillated, making them unsuitable for practical use. In addition, fibers made of polyester containing inorganic fine particles such as silica with a particle diameter of 80 mμ or less are subjected to alkali weight loss treatment to give irregular irregularities of 0.2 to 0.7 μm on the fiber surface, and 50 to 200 microns within these irregularities.
A method has been proposed for improving the depth of color by creating microscopic irregularities of mμ. However, even with this method, the effect of improving the depth of color is insufficient, and on top of that, perhaps due to the extremely complicated shape of the unevenness, the unevenness is destroyed and destroyed by external physical effects such as friction. There are disadvantages in that the damaged portions are significantly discolored or have a difference in gloss compared to other undestructed portions, and furthermore, they easily become fibrillated. The present inventor has created a polyester fiber that does not have the above drawbacks and has excellent color depth and clarity by adding micropores to polyester fiber and coating the fiber with a low refractive index polymer after dyeing. As a result of extensive research and research, we found that by treating polyester fiber obtained by melt-spinning polyester blended with a specific organic low-molecular compound with alkali, we were able to create irregularities smaller than the wavelength of visible light. It can be formed on the entire surface of the fiber, and by further coating the fiber with a low refractive index polymer after dyeing, it has excellent color depth and clarity, has sufficiently little discoloration due to friction, and has good fibril resistance. It was discovered that excellent polyester fibers can also be obtained, and the present invention was achieved. That is, the present invention provides 100 parts by weight of aromatic polyester with an organic low molecular compound that satisfies the following conditions (1) to (4).
A polyester composition containing 0.1 to 30 parts by weight is melt-spun, the resulting polyester fibers are treated with an aqueous solution of an alkali compound to elute 2% by weight or more of the fibers, and then subjected to a dyeing treatment,
Furthermore, it is a polyester fiber structure with improved color, characterized in that it is coated with a polymer having a lower refractive index than the fiber. (1) Substantially stable under the melting conditions of the aromatic polyester, non-reactive with the polyester, and compatible with the polyester. (2) Phase separation from the polyester does not occur when the polyester composition is cooled and solidified. (3) Melting point is 100℃ or higher. (4) Molecular weight is 1000 or less. The aromatic polyester used in the present invention is
The main acid component is aromatic dicarboxylic acid, and the aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, and diphenol dicarboxylic acid. Examples include siethanedicarboxylic acid, methyl terephthalic acid, and methyl isophthalic acid. In addition, glycol components include ethylene glycol,
Aliphatic glycols such as trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, etc.
Alicyclic glycols such as 1,4-cyclohexanedimethanol, hydroquinone, methylhydroquinone, butylhydroquinone, amylhydroquinone, resorcinol, 2,2-bis(4-
hydroxyphenyl)propane [bisphenol A], 1,1-bis(4-hydroxyphenyl)
Cyclohexane [bisphenol Z], bis(4
-hydroxyphenyl) ether and the like can be used. In addition to the above-mentioned dicarboxylic acid component and glycol component, an oxycarboxylic acid component may be used, and examples of the oxycarboxylic acid include oxybenzoic acid, oxynaphthoic acid, and β-hydroxyethoxybenzoic acid. In addition to the above components, the aromatic polyester used in the present invention contains a small proportion (usually 10 mol% or less of the total acid components) of aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and hexahydroterephthalic acid. It may contain alicyclic dicarboxylic acids, 5-sodium sulfone isophthalic acid, etc., and a small amount (usually 10% by weight or less) of polyoxyalkylene glycol may be copolymerized. trimellitic acid in a linear range (usually 1 mol% or less),
A polycarboxylic acid such as pyromellitic acid, a polyol such as glycerin, trimethylolpropane, pentaerythritol, etc. may be copolymerized. Among the above aromatic polyesters, the following general formula (m represents an integer of 2 to 6) A polyester mainly having repeating units represented by the following is preferable, and among them, polyethylene terephthalate and polybutylene terephthalate are particularly preferable. Such aromatic polyester may be synthesized 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. a first step reaction of producing a glycol ester of terephthalic acid and/or a low polymer thereof by reacting with an oxide;
It is produced by a second stage reaction in which the reaction product of the first stage is heated under reduced pressure to perform a polycondensation reaction until a desired degree of polymerization is achieved. Next, the organic low-molecular compound (hereinafter simply referred to as low-molecular compound) to be blended into the aromatic polyester will be explained. In the present invention, the low molecular weight compound blended into the aromatic polyester is (1) substantially stable and non-reactive with the aromatic polyester under the melting conditions of the aromatic polyester, for example at a temperature of +20° C. to the melting point of the polyester; In addition, it is necessary that when blended with the aromatic polyester, it does not cause phase separation and is uniformly compatible with the aromatic polyester. Here, “substantially stable,
"Non-reactive with aromatic polyesters" means that it does not decompose itself, does not decompose aromatic polyesters, or does not react with aromatic polyesters. ) Even when the homogeneous melt obtained by melt-mixing the aromatic polyester and the low-molecular compound is cooled and solidified, the aromatic polyester and the low-molecular-weight compound do not undergo phase separation and remain uniformly compatible. It is necessary that the
For example, when the above-mentioned homogeneous transparent melt is cooled at a cooling rate sufficient to give an amorphous solid, a homogeneous transparent solid is obtained, or phase separation occurs to give an opaque solid. This can be easily determined by looking at the Furthermore, low molecular weight compounds (3) have a melting point of 100℃ or higher,
and (4) the molecular weight must be 1000 or less. If the melting point of the low molecular weight compound is 100℃ or less,
When melt-mixed with an aromatic polyester, it significantly lowers the secondary transition point of the aromatic polyester, making it difficult to handle during molding. The low-molecular compound used in the present invention may be one that satisfies the above conditions (1) to (4), but in addition, from the viewpoint of preventing volatilization during melt-mixing, the low-molecular compound has a boiling point at normal pressure.
A temperature of 250°C or higher, particularly 300°C or higher is preferably used. The low molecular weight compound used in the method of the present invention may be one that satisfies the above conditions, but for example, the following formula () [Here, A ¹ is a divalent aromatic residue or a chain or cyclic aliphatic residue, which may be substituted; R ¹ is an n-valent aromatic residue or a chain or cyclic aliphatic residue. Cyclic aliphatic residues, which may be substituted; n is 1 or 2. However, the imide ring in the above formula is 5 or 6 members. ] Imide compound represented by the following formula () [Here, A ² is a tetravalent aromatic residue, which may be substituted; R ² is a monovalent chain or cyclic aliphatic residue, which may be substituted. Good too. However, the imide rings in the above formula are 5 or 6 members. ] Examples include imide compounds represented by the following. As a compound of the above formula (), the above formula ()
A compound in which at least either A ¹ or R ¹ is an optionally substituted aromatic residue,
In particular, compounds in which A ¹ is a divalent, optionally substituted aromatic residue are preferably used. Further, as the compound of the above formula (), a compound in which R ² is a monovalent, optionally substituted aliphatic residue in the above formula () is preferably used. In the above general formula (), examples of the divalent aromatic residue representing A ¹ include 1,2-phenylene group, 1,2-, 2,3- or 1,8-naphthylene group. Examples of divalent aliphatic residues include linear alkylene groups such as ethylene or trimethylene, and cycloalkylene groups such as 1,2-cyclohexylene. These groups may be substituted with a substituent that is non-reactive with the aromatic polyester (A). Examples of such substituents include lower alkyl groups such as methyl and ethyl, lower alkoxy groups such as methoxy and ethoxy, halogen atoms such as chlorine and bromine, nitro groups, phenyl groups, phenoxy groups, and methyl groups. Good examples include cyclohexyl group and the like. Examples of the n-valent (n=1 or 2) aromatic residue representing R ¹ include phenyl group, naphthyl group,
or expression

A monovalent aromatic residue such as the group [Formula] (where Z is -O-, -SO ₂ - or -CH ₂ -), or a 1,2-phenylene group, 1,2-, 2 , 3- or 1,8-naphthylene group or formula

Mention may be made of divalent aromatic residues such as the group [formula] (where Z is -O-, -SO ₂ - or -CH ₂ -), where n-valent (n = 1 or 2) Examples of aliphatic residues include those having 1 to 1 carbon atoms, such as methyl, ethyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, myricityl, and stearyl.
18 linear alkyl groups or 5- or 6-membered cyclic alkyl groups such as cyclohexyl or cyclopentyl, or ethylene, trimethylene, tetramethylene, hexamethylene, octamethylene,
2 or more carbon atoms such as decamethylene and dodecamethylene
12 linear alkylene groups, 1,3- or 1,4
- a cyclic alkylene group such as a cyclohexylene group,
or

Examples include groups such as [Formula]. These groups representing R ¹ may be substituted with the same substituents as described for A ¹ . In the above formula (), the tetravalent aromatic residue representing A ² is, for example,

【formula】

【formula】

【formula】

[Formula] or

Preferred examples include monocyclic, condensed ring, or polycyclic tetravalent aromatic groups represented by the formula: (Z is the same as defined above). The monovalent chain or cyclic aliphatic residue representing R ² may be a chain alkyl group having 1 to 18 carbon atoms or a 5- or 6-membered cyclic alkyl group as exemplified for R ¹ in the above formula (). Mention may be made of alkyl groups. The groups exemplified above for A ² and R ² may be substituted with the same substituents as described for A ¹ . Examples of the imide compound represented by the above formula () include N-methyl phthalimide, N-ethyl phthalimide, N-butylphthalimide,
N-ethyl-1,8-phthalimide, N-butyl-1,8-naphthalimide, etc.; as a compound when n=2, N,N'-ethylenebisphthalimide, N,N-tetramethylenebisphthalimide , N,N'-hexamethylene bisphthalimide, N,N'-octamethylene bisphthalimide, N,N'-decamethylene bisphthalimide, N,N'-dodecamethylene bisphthalimide, N , N'-neopentylenebisphthalimide, N,N'-tetramethylenebis(1,8-naphthalimide), N,N'-hexamethylenebis(1,8-naphthalimide), N,N'-octa Methylenebis(1,8-naphthalimide), N,
N'-decamethylene bis(1,8-naphthalimide), N,N'-dodecamethylene bis(1,8-
naphthalimide), N,N'-dodecamethylene bissuccinimide, N,N'-dodecamethylene bishexahydrophthalimide, N,N'-1,
4-cyclohexylene bisphthalimide, 1-
Phthalimido-3-phthalimidomethyl-
3,5,5-trimethylcyclohexane, 4,4
-bisphthalimido diphenyl ether, 3,
4′-bisphthalimido diphenyl ether,
Examples include 3,3'-bisphthalimidodiphenyl sulfone, 4,4'-bisphthalimidodiphenyl sulfone, and 4,4'-bisphthalimidodiphenylmethane. Examples of the imide compound represented by the above formula () include N,N'-diethylpyromellitimide, N,N'-dibutylpyromellitimide, N,
N'-dihexylpyromellituimide, N,N'-
Dioctylpyromellittimide, N,N'-didecylpyromellittimide, N,N'-dicyclohexylpyromellittimide, N,N'-bis(3,
3,5-trimethylcyclohexyl)pyromellitimide, N,N'-diethyl-1,4,5,8
-Naphthalenetetracarboxylic acid 1,8-,4,5
- Diimide, etc. can be mentioned. The imide compounds represented by the above formulas () and () can be easily produced from the corresponding acid anhydrides and organic amines by known methods. In the present invention, first, aromatic polyester
A polyester composition is obtained by blending 0.1 to 30 parts by weight of a low molecular compound with 100 parts by weight. If the amount of the low molecular weight compound is less than 0.1 part by weight, the depth and clarity of the color of the final polyester fiber will be insufficient, and as this amount is increased, the depth and clarity of the color will increase. If the amount exceeds 30 parts by weight, no significant improvement is achieved, and the abrasion resistance and durability worsen, and the melt viscosity of the resulting composition decreases significantly, making melt spinning difficult. The blending amount of the low molecular weight compound is more preferably 3 to 20 parts by weight. A composition consisting of an aromatic polyester and a low-molecular compound may be prepared by adding the low-molecular compound to the polyester raw material or the polymerization reaction mixture at any stage until the synthesis of the polyester is completed, and then adding the low-molecular compound to the polyester raw material or the polymerization reaction mixture. It may be a product that has been completely synthesized, or it may be a simple dry blend of polyester chips and a low-molecular compound, or it may be a product that has been melt-mixed in a melt extruder in advance. In addition, after mixing a low-molecular compound heated and melted above its melting point with aromatic polyester chips,
An aromatic polyester in which a low-molecular compound obtained by cooling to below the melting point is adhered to the surface of the chip is also preferably used. The above composition may contain optional additives such as catalysts, oxidation stabilizers, ultraviolet stabilizers, flame retardants, optical brighteners, matting agents, colorants, etc. as necessary. In addition, from the viewpoint of increasing the degree of polymerization or suppressing a decrease in the degree of polymerization during melt spinning, 2.
Chain extenders such as 2'-bis(2-oxazoline) and 2,2'-bis(3,1-benzoxazin-4-one) can also be preferably incorporated. There is no need to employ any special method for melt-spinning the polyester composition obtained in this manner to form fibers, and any ordinary melt-spinning method for polyester fibers may be employed. The fibers spun here may be solid fibers having no hollow portions or hollow fibers having hollow portions. In addition, the outer shape and shape of the hollow part in the cross section of the fiber to be spun,
It may be circular or irregularly shaped. In order to remove a part of the polyester fiber obtained in this way and make it into a porous polyester fiber, after subjecting it to stretching heat treatment or false twisting as necessary, or after making it into a fabric, it is treated with an aqueous solution of an alkaline compound. This can be easily done by processing. Examples of the alkali compound used here include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate, potassium carbonate, and the like. Among these, 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 temperature is preferably in the range of room temperature to 100°C, and the processing time is 1 minute to 1 minute.
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, a large number of special micropores can be formed on the fiber surface and its vicinity, resulting in excellent color depth when dyed. Note that the polyester fiber obtained by the method of the present invention can be treated with an organic solvent as necessary to extract and remove low-molecular compounds remaining in the fiber. Examples of such organic solvents include toluene, xylene, pseudocumene, dioxane, chloroform, methylene chloride,
Examples include dichloroethane, ethanol, ethyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, and chlorobenzene.
These organic solvents are preferably selected appropriately depending on the type of aromatic polyester and low molecular weight compound, especially imide compound. Although this extraction treatment using an organic solvent can be carried out at room temperature, it is preferable to carry out heating within a range that does not impair the morphology and physical properties of the polyester fibers, for example, under conditions of reflux of the organic solvent. Next, the obtained porous polyester fiber is dyed and then coated with a polymer having a lower refractive index than the fiber. Examples of the low refractive index polymer in the present invention include polytetrafluoroethylene. ,
Tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-
Ethylene copolymer, tetrafluoroethylene
Fluorine-containing polymers such as tetrafluoropropylene copolymer, polyfluorovinylidene, polypentadecafluorooctyl acrylate, polyfluoroethyl acrylate, polytrifluoroisopropyl methacrylate, polytrifluoroethyl methacrylate, polydimethylsilane, polymethyl hydro silicon-containing compounds such as diene siloxane and polydimethylsiloxane; acrylic esters such as ethylene-vinyl acetate copolymer; polyethyl acrylate and polyethyl methacrylate;
Examples include, but are not limited to, polyurethane polymers. Among these polymers, one having a refractive index smaller than that of the fiber matrix constituting the fiber product may be appropriately selected and used. In this case, it is desirable to select a material that has as large a difference in refractive index as possible with the substrate fiber. The low refractive index polymer that coats the surface of porous polyester fibers is usually commercially available in the form of an organic solvent solution or an aqueous emulsion, but after dyeing,
A water-based emulsion is preferable because it involves a step of coating the surface area. The method for coating the surface of porous polyester fibers with a low refractive index polymer emulsion is preferably a woven or knitted fabric made of porous polyester fibers, such as a padding method, a spray method, a kiss roll method, a knife coating method, or an adsorption method in a bath. Any method such as the method can be used. The surface coating of the low refractive index polymer in the present invention can be applied to all types of textile products such as tows, filaments, yarn woven and knitted fabrics, and nonwoven fabrics. The reason why extremely excellent color depth and clarity can be obtained by coating the surface of a porous polyester fiber with a large number of micropores with a polymer having a lower refractive index than the porous polyester fiber is as follows. It is explained as follows. Except for objects that emit light by themselves, such as radiators, the color of an object is generally determined by the reflection and absorption of light, but in order to make colors appear deeper and clearer, reflect less light and absorb more light. Regarding light reflection, it is particularly necessary to reduce surface reflected light. This is because the surface-reflected light is reflected as white light, so it hardly contributes to deepening and sharpening the color of the colored body.
This surface reflected light can be broadly divided into specular reflection and diffuse reflection, but if the specular reflection component is reduced by making the surface of the fiber porous as in the present invention, the effect of deepening and sharpening the color can be achieved. It can be further increased. Furthermore, as a method for reducing the amount of surface reflected light, a technique is known both theoretically and empirically in which a material having a lower refractive index than the object constituting the substrate is applied to the surface of the object. An example of this is lens coating technology. This is a technology that reduces the amount of surface reflected light by coating the lens surface with a transparent thin film that has a lower refractive index than glass. Therefore, the synergistic effect of reducing the specular reflection component by making the surface of the fiber porous and reducing the amount of surface reflected light by coating the surface with a low refractive index polymer greatly increases the amount of absorbed light, resulting in an outstanding It is thought that a color effect can be obtained. A more specific explanation will be given below with reference to Examples.
Parts and % in the examples indicate parts by weight and % by weight,
The depth of color and frictional discoloration when the resulting polyester fibers were dyed were measured by the following methods. (i) Depth of color As a measure of the depth of color, bathochromicity (K/
S) was used. This value was determined by measuring the spectral reflectance (R) of the sample fabric using a Shimadzu RC-330 self-recording spectrophotometer.
−Munk). The larger this value is, the greater the deep color effect is. (Measurement wavelength 500
mμ) K/S=(1-R) ² /2R Note that K represents an absorption coefficient and S represents a scattering coefficient. (ii) Resistance to friction discoloration Using a Gakushin type flat abrasion machine for friction fastness testing, the test cloth was abraded a specified number of times under a load of 500 g using a dioset made of 100% polyethylene terephthalate as the friction cloth. hand,
The degree of discoloration was determined using a gray scale for browning. When the wear resistance was extremely low, it was ranked as 1st grade, and when it was extremely high, it was rated as 5th grade. For practical purposes, level 4 or above is required. Examples 1 to 6 100 parts of polyethylene terephthalate chips with an intrinsic viscosity of 0.645 and a softening point of 260°C were dry-blended with a predetermined amount of the low molecular weight compound shown in Table 1, and then the resulting mixture was passed through a circular spinning hole with a pore diameter of 0.3 mm. Melt-spun at 275℃ using a spinneret with 36 holes,
Then, it was stretched at a stretching ratio of 4.5 times according to a conventional method to 75
A raw yarn of denier/36 filament was obtained. This yarn is S-twisted at 2500T/m and Z-twisted at 2500T/m.
The highly twisted yarn was then subjected to a steam treatment at 80° C. for 30 minutes to untwist it. The twisted yarn has a warp density of 47 threads/cm and a weft density of 32.
A satin jersey fabric was woven by alternately arranging two S and Z twists at a thread/cm ratio. The obtained gray fabric was relaxed with a rotary washer for 20 minutes at boiling temperature, then grained, and after blissetting in a conventional manner, it was treated with a 3.5% aqueous sodium hydroxide solution at boiling temperature to achieve a weight loss rate of 10. % fabric was obtained. The fabric after this alkali treatment is made into Dianix Black.
HG-FS (Mitsubishi Chemical Industries, Ltd. product) 130℃ at 15% owf
After dyeing for 60 minutes, the fabric was reduced and washed in an aqueous solution containing 1 g of sodium hydroxide and 1 g of hydrosulfite at 70° C. for 20 minutes to obtain a black dyed fabric. Also, instead of Dianix Black HG-FS15%owf
A blue dyed cloth was obtained by dyeing in the same manner with Resoline Blue FBL (manufactured by BAYER) 4% owf. The dyed fabric was then coated with a low refractive index polymer.
The production of the low refractive index polymer and the surface coating method of polyester fibers were carried out under the following conditions. 30g of dimethylpolysiloxane with a viscosity of 1000CS,
2g tall oil fatty acids containing basic oleic acid, 28
An emulsion was obtained by mixing 0.5 g of wt% ammonia water, 0.75 g of triethanolamine, and 66.75 g of water using a homogenizer. An anionic emulsion treatment agent consisting of 5 g of polymer solids obtained under the above conditions and 300 g of water was applied to the dyed cloth (pickup 75 g).
%), and after drying, it was heat set at 160°C for 1 minute. Table 1 shows the depth and sharpness of the treated fabrics obtained.
Furthermore, the abrasion discoloration resistance of the black-dyed fabric after 200 abrasions was also shown. Example 7 In place of the polyethylene terephthalate chips used in Example 1, 2.5 mol% of 5-Na sulfoisophthalic acid was copolymerized and the intrinsic viscosity was
The same procedure as in Example 1 was carried out except that 100 parts of copolymerized polyethylene terephthalate chips having a softening point of 0.490°C and a softening point of 258°C were used. The results are shown in Table 1. Example 8 In place of the polyethylene terephthalate chips used in Example 1, 100 parts of copolymerized polyethylene terephthalate chips with an intrinsic viscosity of 0.640 and a softening point of 259°C, which were copolymerized with 4% by weight of polyoxyethylene glycol having an average molecular weight of 600, were used. The same procedure as in Example 1 was carried out except that . The results are shown in Table 1. Example 9 The same procedure as in Example 1 was carried out except that polytetramethylene terephthalate chips having an intrinsic viscosity of 0.88 were used in place of the polyethylene terephthalate chips used in Example 1, and the melt spinning temperature was 235°C. The results are shown in Table 1. Comparative Examples 1 to 4 Examples 1, 7, 8, and 9 except that the low molecular weight compounds used in Examples 1, 7, 8, and 9 were not used, respectively.
The same procedure as 8 and 9 was carried out. The results are shown in Table 1. Table 1 shows the depth of color of the black dyed fabric and the abrasion discoloration resistance after 200 abrasions. The vividness of the color of the blue-dyed fabric was visually judged according to the following criteria and is shown in Table 1. ◎; Sharpness is significantly higher than the standard 〇; Sharpness is higher than the standard st; Standard △; Sharpness is lower than the standard ×; Sharpness is significantly lower than the standard

【table】

【table】

Claims (1)

[Claims] 1. The following conditions (A) are added to 100 parts by weight of aromatic polyester.
A polyester composition containing 0.1 to 30 parts by weight of an organic low-molecular compound that satisfies (D) is melt-spun, and the resulting polyester fibers are treated with an aqueous solution of an alkaline compound so that 2% by weight or more of the fibers are 1. A polyester fiber structure with improved color, characterized in that it is eluted, dyed, and then coated with a polymer having a lower refractive index than the fiber. (A) Substantially stable under the melting conditions of the aromatic polyester, non-reactive with the polyester, and compatible with the polyester. (B) No phase separation occurs from the polyester when the polyester composition is cooled and solidified. (C) Melting point is 100℃ or higher. (D) The molecular weight is 1000 or less. 2 Aromatic polyester has the following general formula (m represents an integer of 2 to 6) The polyester fiber structure with improved color according to claim 1, which is a polyester mainly containing repeating units represented by the following.