JPS6328129B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing vividly dyeable polyester fibers. More specifically, it has special micropores,
This invention relates to a method for producing polyester fibers that 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 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 of imparting irregularities to the surface of polyester fibers, polyester fibers made of polyoxyethylene glycol or 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 fiber surface, or polyester fibers containing fine particles of inert inorganic substances such as zinc oxide or calcium phosphate are treated with an alkaline aqueous solution to elute the inorganic fine particles. A method for producing hygroscopic fibers that forms pores has been proposed. However, the fibers obtained by these methods do not have the effect of improving color depth, and instead show a decrease in visual density. 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, Perhaps due to the diffuse reflection of light by the micropores, the visual density decreases, and even when dyed in a dark color, it appears whitish.Furthermore, the strength of the resulting fibers decreases markedly, and they become easily fibrillated. and cannot be put to practical use. In addition, polyester fibers containing inorganic fine particles such as silica sol with a particle size of 80 mμ or less are subjected to alkali weight reduction treatment to provide irregular irregularities of 0.2 to 0.7 μm on the fiber surface and 50 to 200 μm within these irregularities.
A method of improving the depth of color by creating microscopic irregularities of mμ, or dry process silica containing aluminum oxide with a particle size of 100mμ or less, or dry process silica with a particle size of 100mμ or less that blocks silanol groups on the particle surface. A method has been proposed for improving color development by imparting a specific surface morphology to the blended polyester fibers by subjecting them to alkali dissolution treatment. However, even with this method, the effect of improving the depth of color is insufficient, and in addition, the unevenness is destroyed by external physical effects such as friction, probably due to the extremely complex uneven shape. There are disadvantages in that the portions are significantly discolored or have a difference in gloss compared to other undestructed portions, and furthermore, they easily become fibrillated. The inventor of the present invention has conducted extensive research in an attempt to provide polyester fibers that are free from the above-mentioned drawbacks and have excellent color depth and clarity by adding micropores to polyester fibers. The phosphorus compound and the alkaline earth metal compound in a specific ratio are added to the polyester reaction system without reacting in advance, and the two are reacted inside the reaction system to precipitate insoluble fine particles. By treating fibers melt-spun from polyester with alkali, it is possible to form many irregularities on the fiber surface that are smaller than the wavelength of visible light, and this increases the depth of the color when colored. It was discovered and proposed earlier that polyester fibers with excellent clarity, sufficiently small discoloration due to friction, and excellent fibril resistance can be obtained. However, the use of polyester fibers obtained in this manner is limited in fields where more vivid dyeing properties are required, and further improvement in vivid dyeing properties is desired. The inventor of the present invention has conducted extensive research in an effort to provide a polyester fiber that has better color staining and clarity when dyed, has sufficiently little discoloration due to friction, and has sufficient fibrillation resistance for practical use. It has been discovered that the above object can be achieved by treating polyester fibers containing a specific imide compound in addition to internally precipitated particles consisting of a compound and an alkaline earth metal compound with an aqueous alkaline solution. Furthermore, the color improvement effect of using an imide compound in combination was also observed when it was used in combination with an alkali-soluble or soluble metal-containing compound such as the above-mentioned silica sol or dry process silica. The reason why the color is synergistically improved by the combined use of such imide compounds is not clear, but it is due to the fact that the imide compound is compatible with polyester, in addition to the effect of the fine irregularities on the fiber surface mentioned above. It is thought that the effects of ultrafine pore formation are complicatedly superimposed. The present invention was completed after further studies based on these findings. That is, in the present invention, when a polyester fiber containing an alkali-soluble or decomposable metal-containing compound is subjected to a weight reduction treatment with an aqueous solution of an alkali compound to produce brightly dyeable polyester fiber, the polyester fiber is previously subjected to the following conditions ( An imide compound that satisfies 1) to (4) is blended, and the weight loss rate of the polyester fiber by treatment with an aqueous alkali compound solution is 2% by weight.
This is a method for producing vividly dyeable polyester fiber, characterized by the above. (1) It is substantially stable under the melting conditions of the polyester that is the base of the polyester fiber, is non-reactive with the polyester, and is compatible with the polyester. (2) No phase separation occurs when the molten mixture with the polyester is cooled and solidified. (3) Melting point is 100℃ or higher. (4) Molecular weight is 1000 or less. The polyester in the present invention has terephthalic acid as the main acid component and at least one type of glycol, preferably at least one type of alkylene selected from ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, and hexamethylene glycol. The main target is polyester whose main glycol component is glycol. 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. Furthermore, polycarboxylic acids such as trimellitic acid, pyromellitic acid, etc., glycerin,
There is no problem even if polyols such as trimethylolpropane, pentaerythritol, etc. are copolymerized. Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, terephthalic acid and ethylene glycol are usually subjected to a direct esterification reaction, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol are transesterified, 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 the present invention, the alkali-soluble or decomposable metal-containing compound contained in the above polyester fiber is one that can form micropores by alkali treatment of the metal-containing compound-containing polyester fiber. If so, there is no need to limit it in particular; for example, at any stage until the synthesis of the polyester described above is completed, (a) 0.3% of the acid component constituting the polyester.
~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 group; m represents 0 or 1; ] A phosphorus compound represented by and (b) an alkaline earth metal compound are prepared without reacting (a) and (b) in advance.
By adding so that the total number of equivalents of metals (a) and (b) is 2.0 to 3.2 times the number of moles of the phosphorus compound of (a), (a )and
Examples include insoluble particles precipitated by reaction with (b). In the above formula () representing a phosphorus compound, R ¹ and R ² are a hydrogen atom or a monovalent organic group. Specifically, this monovalent organic group is 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, and 1
The valent organic group is the same as the definition of the organic group for R ¹ and R ² above, and may be the same as or different from R ¹ and R ² , and the metal is particularly an alkali metal or an alkaline earth metal. is preferable, especially
Particularly preferred are Li, Na, K, Mg _1/2 , Ca _1/2 , Sr _1/2 and Ba _1/2 . 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, phosphorous acid Phosphite triesters such as trimethyl acid, triethyl phosphite, tributyl phosphite, and triphenyl phosphite; phosphorous acid mono- and diesters such as methyl acid phosphite, ethyl acid phosphite, butyl acid phosphite; A phosphorus compound obtained by reacting a compound with glycol and/or water, and a predetermined amount of the above phosphorus compound with a compound of an alkali metal such as Li, Na, K, etc. or an alkali such as Mg, Ca, Sr, Ba, etc. One or more phosphorus compounds selected from phosphorus compounds obtained by reacting with earth metal compounds can be used. The alkaline earth metal compound to be used in combination with the above phosphorus compound is not particularly limited as long as it reacts with the above phosphorus compound to form a salt insoluble in polyester, and alkaline earth metal acetates, oxalates, etc. , organic carboxylates such as benzoates, phthalates, stearates, inorganic acid salts such as borates, sulfates, silicates, carbonates, bicarbonates, halides such as chlorides, ethylenediamine 4 Examples include chelate compounds such as acetic acid complexes, hydroxides, oxides, alcoholates such as methylates, ethylates, and glycolates, and phenolates. organic carboxylates, halides, chelate compounds that are particularly soluble in ethylene glycol;
Alcoholates are preferred, and organic carboxylates are particularly preferred. The above alkaline earth metal compounds may be used alone or in combination of two or more. When adding the above phosphorus compound and alkaline earth metal compound, in order to give the final polyester fiber excellent color depth and friction durability, the amount of phosphorus compound to be used and the amount of the phosphorus compound It is necessary to specify the ratio of the amount of alkaline earth metal compound used to the amount 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. If the amount increases, the depth of the color will no longer show any significant improvement, the abrasion resistance will deteriorate, and furthermore, it will be difficult to obtain a polyester with a sufficient degree of polymerization and softening point, and furthermore, yarn breakage will occur frequently during spinning. This problem occurs. For this reason, the amount of the phosphorus compound added should be in the range of 0.3 to 3 mol%, particularly preferably in the range of 0.5 to 2 mol%, based on the total acid components constituting the polyester. In addition, if the total number of metal equivalents contained in the phosphorus compound and the alkaline earth metal compound is less than 2.0 times the number of moles of the phosphorus compound, the color depth of the resulting polyester fiber will be insufficient, Moreover, 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, not only the depth of color becomes saturated, but also the strength and fibril resistance of the fibers decrease. Therefore, the total number of metal equivalents of the phosphorus compound and the alkaline earth metal compound is 2.0 to 3.2 with respect to the number of moles of the phosphorus compound.
The amount should be in the range of 2.0 to 3.0, especially 2.0 to 3.0
A range of is preferred. The above-mentioned phosphorus compound and alkaline earth metal compound can be added in any order at any stage until the synthesis of the polyester is completed. However, only phosphorus compounds are
If the alkaline earth metal compound is added before the first stage reaction is completed, the completion of the first stage reaction may be inhibited, and if only the alkaline earth metal compound is added before the first stage reaction is completed, the reaction may be inhibited. When is an esterification reaction, coarse particles are generated during this reaction,
In the case of transesterification, the reaction may proceed abnormally quickly and cause bumping, so in this case it is preferably about 20% by weight or less. It is preferable that at least 80% by weight of the alkaline earth metal compound and the total amount of the phosphorus compound are added after the first stage reaction of polyester synthesis is substantially completed. In addition, the timing of addition of phosphorus compounds and alkaline earth metal compounds is
When the reaction in the second stage has progressed too much, particles tend to aggregate and coarsen, and the color depth of the final polyester fiber tends to be insufficient. Preferably, the viscosity is before reaching 0.3. The above-mentioned phosphorus compound and alkaline earth metal compound may each be added at once, added in two or more divided portions, or added continuously. The above-mentioned phosphorus compound and alkaline earth 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 alkaline earth 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 will be contained. This is not preferable because the effect of improving the color depth of the polyester fiber finally obtained is not recognized. In the present invention, any catalyst can be used for the first stage reaction, but among the above alkaline earth metal compounds, there are some that have the ability to catalyze the first stage reaction, particularly the transesterification reaction. When such a compound is used, it is not necessary to use a separate catalyst, and the alkaline earth metal compound can be added before or during the first stage reaction to also serve as a catalyst. Since the bumping phenomenon may occur as described above, the amount used is preferably limited to less than 20% by weight of the total amount of the alkaline earth metal compound added. In addition to the above-mentioned compounds, examples of the alkali-soluble or decomposable metal-containing compounds to be contained in the polyester fibers in the present invention include silica sol,
An average consisting of at least one selected from dry process silica containing aluminum oxide, dry process silica with blocked silanol groups on the particle surface, alumina sol, fine particulate alumina, ultrafine titanium oxide, calcium carbonate sol, and fine particulate calcium carbonate. Inert inorganic fine particles having a primary particle diameter of 100 mμ or less can also be preferably mentioned. The average primary particle diameter of the above inert inorganic fine particles is
The preferred range is 100 mμ or less, preferably 6 to 75 mμ, more preferably 10 to 50 mμ. In addition, the content of such inert inorganic fine particles in polyester fiber is
The range of 0.3 to 10% by weight is preferable, especially 0.5 to 10% by weight.
A range of 5% by weight is particularly preferred. The above-mentioned inert inorganic fine particles are prepared as a dispersion slurry or sol of glycol, alcohol, water, etc. For example, in the case of silica sol, an aqueous silica sol obtained by removing alkali from water glass is directly added to the aqueous silica sol with glycol and/or water. Alternatively, it is preferable to mix alcohol and add it at any stage until the water in the aqueous silica sol is replaced with glycol and/or alcohol and the polyester synthesis reaction is completed. In the present invention, the imide compound used in combination with the above alkali-soluble or decomposable metal-containing compound is:
(1) Substantially stable under the melting conditions of polyester, which is the base material of polyester fibers, for example at a temperature of 20°C above the melting point of polyester, and non-reactive with polyester, and uniform without phase separation when mixed with polyester. It is necessary that the material be compatible with the above. Here, "substantially stable and non-reactive with the polyester" means that it does not decompose itself, does not decompose the polyester, and does not react with the polyester. The imide compound is further melt-mixed with (2) polyester, and the resulting homogeneous melt is cooled and solidified.
It needs to be able to maintain a homogeneous state of compatibility with the polyester without causing phase separation. This provides a homogeneous transparent solid, for example, when the homogeneous transparent melt is cooled at a cooling rate sufficient to provide an amorphous solid. This can be easily determined by observing whether phase separation occurs to give an opaque solid. Furthermore, the imide compound needs to have (3) a melting point of 100° C. or higher, and (4) a molecular weight of 1000 or lower.
If the melting point of the imide compound is lower than 100° C., when it is melt-mixed with polyester, it will significantly lower the secondary transition point of the polyester, making it difficult to handle during melt spinning. The imide 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 imide compound has a boiling point at normal pressure.
A temperature of 250°C or higher, particularly 300°C or higher is preferably used. The imide 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 ⁴ 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 ⁵ 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 one of A ¹ and R ⁴ 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 ⁵ in the above formula () is a monovalent, optionally substituted aliphatic residue 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 substituents that are non-reactive with polyester. 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,
Examples include a phenyl group, a phenoxy group, and a cyclohexyl group which may be substituted with a methyl group. As the n-valent (n=1 or 2) aromatic residue representing R ⁴ , for example, phenyl group, naphthyl group, formula

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

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

The groups of [Formula] can be mentioned. These groups representing R ⁴ 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

A monocyclic, condensed ring or polycyclic tetravalent aromatic group represented by the formula: (Z is the same as defined above) is preferred. The monovalent chain or cyclic aliphatic residue representing R ⁵ 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 ⁴ in the above formula (). Examples include alkyl groups. The groups exemplified above for A ² and R ⁵ 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-naphthalimide, N-butyl-1,8-naphthalimide, etc.; when n=2, compounds include N,N'-ethylenebisphthalimide, N,N'-tetramethylenebisphthal imide, N,N'-hexamethylene bisphthalimide, N,N'-octamethylene bisphthalimide, N,N'-decamethylene bisphthalimide, N,N'-dodecamethylene bisphthalimide, N,N'-neopentylene bisphthalimide, N,N'-tetramethylene bis(1,8
-naphthalimide), N,N'-hexamethylenebis(1,8-naphthalimide), N,N'-octamethylenebis(1,8-naphthalimide), N,N'-decamethylenebis(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'-bisphthalimide diphenyl ether, 3,4 '-bisphthalimido diphenyl ether, 3,3'-bisphthalimido diphenyl sulfone, 4,4'-bisphthalimido diphenyl sulfone, 4,4'-bisphthalimido diphenyl methane, etc. I can give it to you. 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. The above imide compounds may be used alone or in combination of two or more. It may be added to the polyester at any stage before the end of the spinning process of melt-spinning the polyester into fibers. For example, it may be added to the polyester raw materials, added during the synthesis of the polyester, or It may be added between the end of synthesis and the time of melt spinning. In any case, it is preferable to mix the components in a molten state after addition. If the amount of the imide compound added is too small, the effect of improving the color depth and clarity of the final polyester fiber will be insufficient; on the other hand, if it is too large, the color depth and clarity will no longer be improved. The effect does not show any significant improvement, and on the contrary, the abrasion resistance and durability deteriorate, and the melt viscosity of the polyester composition decreases significantly, making melt spinning difficult. Therefore, the amount of the imide compound added to the polyester is preferably in the range of 0.1 to 30% by weight, particularly preferably in the range of 0.5 to 20% by weight, based on the polyester fiber. In order to melt-spun the thus obtained polyester blended with an alkali-soluble or decomposable metal-containing compound and imide compound into fibers, there is no need to adopt any special method, and ordinary polyester A method of melt spinning the fibers is optionally employed. 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 to be spun may be circular or irregular. In order to remove a part of the polyester fiber obtained in this way, after subjecting it to stretching heat treatment or false twisting as necessary, or after making it into a fabric, heating it in an aqueous solution of an alkaline compound, or This can be easily carried out by subjecting an aqueous solution of an alkali compound to pad/steam treatment. 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. Further, alkaline dissolution promoters such as cetyltrimethylammonium bromide, lauryldimethylbenzylammonium chloride, etc. can be used as appropriate. The amount of alkaline compound eluted and removed by treatment with an aqueous solution should be in the range of 2% by weight or more based on the weight of the fiber. By treating the fiber with an aqueous solution of an alkaline compound in this manner, 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 appropriately subjected to a known post-deepening process. As the post-deepening treatment, a method of coating the surface of the polyester fiber with a polymer having a refractive index lower than that of the polyester, such as dimethylpolysiloxane, tetrafluoroethylene-propylene copolymer, etc., is preferred. Can be adopted. Furthermore, 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 whitening agents, 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 As a measure of 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. K/S=(1-R) ² /2R (measurement wavelength: 500 mμ) In addition, K shows an absorption coefficient and S shows 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 jersey made of 100% polyethylene terephthalate as the friction cloth. hand,
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. Examples 1 to 6 100 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 the mixture was heated to 140 parts over a period of 4 hours under a nitrogen gas atmosphere. The transesterification reaction was carried out while raising the temperature from °C to 230 °C and distilling the generated methanol out of the system. Subsequently, 0.5 part of trimethyl phosphate (relative to dimethyl terephthalate) is added to the resulting reaction product.
0.693 mol%) and 0.31 part of calcium acetate monohydrate (1/2 times the mole relative to trimethyl phosphate).
To 9.31 parts of a clear solution of diester calcium salt of phosphate prepared by reacting in 8.5 parts of ethylene glycol at a temperature of 120° C. for 60 minutes under total reflux, 0.57 parts of calcium acetate monohydrate (relative to trimethyl phosphate) was added at room temperature. 9.88 parts of a mixed transparent solution of diester calcium phosphate and calcium acetate obtained by dissolving 0.9 times mole) were added thereto, followed by 0.04 part of antimony trioxide, and the mixture was transferred to a polymerization vessel. Next, the pressure was reduced from 760 mmHg to 1 mmHg over 1 hour.
At the same time, the temperature was raised from 230°C to 285°C over 1 hour and 30 minutes. Polymerize for an additional 3 hours at a polymerization temperature of 285℃ under a reduced pressure of 1 mmHg or less, for a total of 4 hours and 30 minutes, to reduce the intrinsic viscosity.
A polymer with a softening point of 0.641 and a softening point of 259°C was obtained. After the reaction was completed, the polymer was made into chips according to a conventional method. A predetermined amount of the imide compound shown in Table 1 was dry-blended with 100 parts of this chip, and then the resulting mixture was melt-spun at 275°C using a spinneret with 36 circular spinning holes with a hole diameter of 0.3 mm. Then, according to the usual method, it was stretched at a stretching ratio of 3.5 times to 75 denier/
A raw yarn of 36 filaments was obtained. This yarn has S twist of 2500T/m and Z twist of 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, preset using a conventional method, and then treated with a 3.5% sodium hydroxide aqueous solution at boiling temperature to achieve a weight loss rate of 10. % fabric was obtained. Dianix fabrics after these alkali treatments
Black HG-FS (Mitsubishi Chemical Industries, Ltd. product) 15% owf
After staining at 130℃ for 60 minutes, sodium hydroxide 1
A black dyed cloth was obtained by reduction washing at 70° C. for 20 minutes with an aqueous solution containing 1 g/g/g/hydrosulfite and 1 g/g hydrosulfite. Table 1 shows the color depth and friction discoloration resistance of these black cloths after 200 abrasions. Example 7 100 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. 30 minutes after the start of the transesterification reaction, the average primary particle size using ethylene glycol as a dispersion medium was 30 m.
A silica sol having a concentration of 20% by weight was added so that silicon oxide particles accounted for 1.0% by weight based on the resulting polymer. After completion of the transesterification reaction, 0.06 parts (0.083 mol % based on dimethyl terephthalate) of trimethyl phosphate and 0.04 parts of antimony trioxide were added to the obtained reaction product, 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 °C for a total of 4 hours and 30 minutes to obtain a polymer having an intrinsic viscosity of 0.636 and a softening point of 262 °C. After the reaction was completed, the polymer was made into chips according to a conventional method. Hereinafter, using this chip, 1-phthalimido-3-phthalimidomethyl-
Dry blending with 3,5,5-trimethylcyclohexane, melt spinning, stretching, high twisting, untwisting, weaving, texturing, alkali weight reduction treatment, dyeing and reduction washing were carried out. The results were as shown in Table 1. Comparative Examples 1-2 The same procedures as in Examples 1 and 7 were carried out, except that the organic compound (imide compound) used in Examples 1 and 7 was not used. The results are shown in Table 1.

【table】

【table】

Claims (1)

[Scope of Claims] 1. When manufacturing polyester fibers having micropores by reducing the amount of polyester fibers containing an alkali-soluble or decomposable metal-containing compound with an aqueous solution of an alkali compound, the polyester fibers are subjected to the following treatment in advance. 1. A method for producing vividly dyeable polyester fibers, which comprises blending an imide compound that satisfies conditions (1) to (4) and controlling the weight loss rate of the polyester fibers by treatment with an aqueous alkali compound solution to 2% by weight or more. (1) It is substantially stable under the melting conditions of the polyester that is the base of the polyester fiber, is non-reactive with the polyester, and is compatible with the polyester. (2) No phase separation occurs when the molten mixture with the polyester is cooled and solidified. (3) Melting point is 100℃ or higher. (4) Molecular weight is 1000 or less.