JPS5921719A - Preparation of water absorbing polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the titled polyester fibers having improved hygroscopicity and durability thereof, etc., by melt spinning a polyester containing a water absorbing pore-forming agent and a specific organic compound, and treating the resultant fibers with an aqueous solution of an alkali. CONSTITUTION:A polyester containing (A) a water absorbing pore-forming agent, e.g. sodium benzenesulfonate-3,5-di(carboxylate Mg1/2), and (B) an organic compound satisfying substantially stable conditions under the melting conditions of the polyester, unreactive and compatible with the polyester, without causing the phase separation from the polyester on cooling and solidifying a melt mixture thereof with the polyester, and having >=100 deg.C melting point and <=1,000 molecular weight, e.g. N-methylphthalimide, is melt spun into fibers, which are then treated with an aqueous solution of an alkali compound, e.g. sodium hydroxide, to elute 2wt% or more fibers and give the aimed water absorbing polyester fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing water-absorbing polyester fibers. More specifically, the present invention relates to a method for producing polyester fibers that are sufficiently superior in water absorption, hygroscopicity, durability, etc., and have improved color depth when dyed.

Polyester has many excellent properties and therefore has an extremely wide range of uses as a synthetic fiber. However, since polyester fibers are hydrophobic, their use in fields where a water absorbency of 1 hygroscopicity is required is limited.

Conventionally, as a method for imparting thrust water absorbency and hygroscopicity to polyester PH1, a method has been used in which a hydrophilic compound such as polyalkylene glycol or polyalkylene glycol and an organic sulfonic acid metal salt is blended with polyester before forming it into fibers. is proposed. However, the fibers obtained by this method do not have sufficient water absorption and hygroscopicity, and their durability deteriorates more easily than when washing under equal pressure.Furthermore, their physical properties such as light resistance and heat resistance also deteriorate. be.

On the other hand, as a method for improving water absorption and hygroscopicity by imparting uneven water absorption pores to the surface of polynisder fibers, the above-mentioned polyester fibers containing polyalkylene glycol or polyalkylene glycol and an organic sulfonate are mixed in an alkaline aqueous solution. A method of forming wrinkle-like micropores arranged in the fiber axis direction on the fiber surface by treating the fiber with
1-element inorganic compounds, copper oxide, alumina, sodium oxide, tin oxide, titanium phosphate, zirconium oxide,
Polyester fibers containing fine particles of inert inorganic substances such as various inorganic compounds containing silicon are false-twisted as necessary, and then treated with an alkaline aqueous solution to elute the inorganic fine particles. Methods for forming holes have been proposed. However, the polyester fibers obtained by these methods have insufficient water absorption and hygroscopicity because shallow micropores are formed only on the surface of the fibers, and the scattering of light due to these micropores is insufficient. There is a rattle.

The inventors of the present invention have made intensive studies to provide polyester fibers with excellent water absorption and hygroscopicity, and have found that modified polyesters copolymerized with organic sulfonic acid compounds, phosphorus compounds such as monomethyl di-Na dibenzene sulfonate, and sodium benzenesulfonate.
-3,5-di(sodium carboxylate), alkylsulfone C
*The process of reducing the weight of polyester fibers mixed with sulfonic acid compounds such as Na etc. using an alkaline aqueous solution.
Therefore, it is possible to form a large number of water absorption pores consisting of fine pores communicating not only to the fiber surface but also to the inside of the fiber, and by doing so, it has excellent water absorption, moisture resistance, and durability, and is suitable for practical use. I learned that polyester fibers with strength and fibril resistance can be obtained, and proposed this method earlier.

However, it is undeniable that the color depth of the dyed polynisder fibers obtained in this way is inferior due to light scattering by the pores, and the density is the same as that of ordinary polyester fibers. Usually, a large amount of dye must be used to obtain this color, so in applications where deep colors and a high degree of color fastness are required, such as in the field of sportswear, dyeing agents such as laundry contamination must be avoided. There are cases where security becomes a problem, and it is desired that this problem be resolved.

As a result of intensive studies aimed at providing polyester fibers that are sufficiently superior in water absorption, hygroscopicity, and durability, and have improved color depth when dyed, the inventors have surprisingly found the above-mentioned polyester fibers. By melt-spinning a polyester blended with a specific imide compound in addition to a water-absorbing pore-forming agent, and treating the resulting polyester fiber with an alkaline aqueous solution, the fiber has water-absorbing pores and the entire surface of the fiber is exposed to visible light. A polyester fiber with a roughened surface with irregularities that are small in terms of wavelength υ is obtained, and despite the presence of water absorption holes, the depth and vividness of the color when dyed are improved, and the amount of dye used can be reduced. It has been found that the color fastness of deep colors is improved to a practical level, and that water absorption and hygroscopicity are synergistically improved, probably due to improved communication of water absorption pores.

The effect of improving color, water absorption, and hygroscopicity by using the imide compound in combination was also observed when fine particles of the inert inorganic substance were used as the water absorption pore forming agent. The present invention was completed as a result of repeated studies based on these findings.

That is, the present invention provides a water absorption pore forming agent and the following conditions (1) to (4).
A water-absorbing polyester fiber characterized by melt-spinning polynisdel blended with an organic compound that satisfies the following, and treating the obtained polyester fiber with an aqueous solution of an alkaline compound to elute more than 2 folds of the fiber. This is the manufacturing method.

(1) Substantially stable under the melting conditions of the polyester, non-reactive with the polyester, and compatible with the polyester.

(2) No phase separation occurs from the polyester when the molten mixture with the polyester is cooled and solidified. (3) The melting point is 100°C or higher.

(4) The number of cotyledons is 1000 or less.

The polyester in the present invention has terephthalic acid as its main acid component and at least one type of glycol, preferably ethylene glycol, trimethylene glycol, or tetramethylene glycol.

The main target is polyester whose main glycol component is at least one alkylene glycol selected from pentamethylene glycol and hexamethylene glycol.

It may also be a polyester in which part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/
Alternatively, it may be a polyester in which a part of the glycol component is replaced with the above-mentioned glycol other than the main component or diol component other than 1.

The difunctional carboxylic acid other than terephthalic acid used here includes, for example, inctaric acid.

Aromatic, fatty acids such as naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, di;yenoxyethane dicarboxylic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, adipic acid, sepacic acid, 1,4-cyclohexane dicarboxylic acid Tribe.

Examples include alicyclic difunctional carboxylic acids. Examples of diol compounds other than the above-mentioned glycols include aliphatic compounds such as cyclohexane-1,4-dimetatool, neopentyl glycol, bisphenol A, and bisphenol.

Examples include alicyclic and aromatic diol compounds and polyoxyalyalene glycol.

Furthermore, polycarboxylic acids such as trimellitic acid, pyromellitic acid, etc., polyols such as glycerin, trimethylolpropane, pentaerythritol, etc. are copolymerized to the extent that the polyester is substantially linear (usually 1 mol% or less). There is no problem.

Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, it is usually a direct esterification reaction between prephthalic acid and ethylene glycol, or a transesterification reaction between a lower alkyl ester of terephthalic acid such as dimethyl pre-7talate and ethylene glycol. A first stage reaction in which terephthalic acid and ethylene oxide are reacted to produce a glycol ester of terephthalic acid and/or a low polymer thereof, and a desired polymerization is achieved by heating the first stage reaction product under reduced pressure. It is produced by a second step of polycondensation reaction up to 1iK.

The water absorption pore forming agent used in the present invention may be any material that can substantially improve the water absorption rate determined by the measuring method described below when polyester fibers containing the water absorption pore forming agent are treated with an alkaline aqueous solution. There are no particular restrictions, and one example is a modified polyester copolymerized with an organic sulfonic acid compound represented by the following general formula (1). be able to.

...(1) S OIM' In the formula, A is a trivalent aromatic group or an aliphatic hydrocarbon group, and among them, an aromatic group is preferable. Ml is a metal or a hydrogen atom, and particularly preferably an alkali metal or an alkaline earth metal. X is an ester-forming functional group, and its specific example is 0 0 0 70+OHt+b-(0÷0HdyJ, OH, -cmo0
+OHt%-%OH1 (However, R is a lower alkyl group or a phenyl group.

(a and d are integers of 1 or more, b is an integer of 2 or more), etc. Yl-1: represents a nonester-forming functional group or a hydrogen atom, which is the same as or different from Yl-1, and is preferably an ester-forming functional group. Among such organic metal sulfonates, particularly preferred specific examples include Na (or K) 3,5-di(carbomethoxy)benzenesulfonate + Na (or K) L7-di(carbomethoxy)naphthalene-1-sulfonate; Examples include Na (or K) 2,5'-bis(hydroxyethoxy)benzenesulfonate.

In order to produce a modified polyester copolymerized with such an organic sulfonic acid compound, an organic sulfone is added at any stage before the synthesis of the polyester described above is completed, preferably at any stage before the first stage reaction is completed. An acid compound may be added. At this time, the amount of the organic sulfonic acid compound to be used is within a range of 2 to 16 molti relative to the bifunctional carboxylic acid component (excluding the organic sulfonic acid component) K, mainly consisting of terephthalic acid, constituting the modified polyester. is preferred. The amount of the modified polyester to be mixed with the polyester is preferably 5 to 100 parts by weight of the modified polyester per 100 parts by weight of the polyester.

In addition to the above-mentioned modified polynistyl, the water absorption pore-forming agent may also preferably include a phosphorus compound or a sulfonic acid compound represented by the following general formula (U); (II) or (W).

(0) m 1 vo-p-oM' ・−・・−・−(DJ formula, Ml is a metal, especially an alkali metal.

r Alkaline earth metal, Mn+/Rose, cO+/Yi or Z
n(/! is preferable, especially LL, Na, K
, Oat/yHM3+/l is particularly preferred. m is 0
Or 1. (2) is a monovalent organic group, specifically an alkyl group, aryl group, alkylaryl group, aralkyl group, or , t is an integer greater than or equal to 2, p
is an integer of 1 or more), etc., 2 is -OH, -OV'
.

-OM' or a -valent organic group, V is the same as the definition of V above, V/, V and t may be the same or different, Ml is the same as the definition of M1 above, Ml and M
The di- or monovalent organic group which may be the same as or different from 2 is the same as the definition of the inorganic group in V above, and may be the same or different from .

Preferred specific examples of such phosphoric compounds include monomethyl di-sodium phosphate and dimethyl mono-sodium phosphate.

Monophenyl diphosphate, monomethylmonoMg phosphate,
MonomethylmonoMn phosphate, polyoxyethylene (go
5 mole addition] salt to lauryl ether phosphate ([05 mole addition means addition of 5 moles of ethylene oxide, hereinafter the same meaning), polyoxyethylene (io's mole addition) lauryl ether phosphate 7A) Mgm + polyoxyethylene (addition of 10,050 moles) methyl ether phosphate Na salt, monoethyl di-sulfite, diphenyl monolJa, polyoxyethylene (addition of go s o moles) methyl ether phosphite di Na, phenylphosphonate monomethylmonoNa, nonylbenzenephosphonate monomethylmonoNa, phenylphosphinate monomethylmonoNa, and the like can be mentioned.

505M' In the formula, Ml and M4 are metals, and Ml is particularly an alkali metal, an alkaline earth metal, Mn+/110o+
7t or Zn, C is preferable, especially lL+1°N
a, x, Oat/l+ Ml (t/l is particularly preferred - E
l, i. M′ metal is particularly preferably an alkali metal or an alkaline earth metal, especially Li, Na, K
, C! at/l 1Mg+/l is particularly preferred, M
8 and M4 may be the same or different. n is 1 or 2. W is a hydrogen atom or an ester-forming functional group, and the ester-forming functional group is 1000R'' (where R'' is a hydrogen atom.

C 1-4 aryl group or phenyl group) or -0
0moO(OH*+2.1B OH (however, t is an integer of 2 or more.

p is an integer of 1 or more), etc. are preferred.

Preferred specific examples of such sulfonic acid compounds include 3-
Carbomethoxybenzenesulfonic acid Na-5-carboxylic acid Na, 3-carbomethoxybenzenesulfonic acid Na-
5-carboxylic acid, 3-carbomethoxybenzenesulfonic acid K -5-carboxylic acid, 3-hydroxyethoxycarbonylbenzenesulfonic acid Na-5-carboxylic acid N
a.

Na-5-carboxylic acid Na-3-carboxybenzenesulfonic acid, Na-5-carboxylic acid 3-hydroxyeth-oxycarbonylbenzenesulfonic acid flRMgt7t.

Benzenesulfonic acid Na-3,5-di(carboxylic acid Na)
), benzenesulfonic acid Na, -3,5-di(carboxylic acid Mg+7t), and the like.

B-505M' ...... (■) In the formula, B is an alkyl group having 3 to 30 carbon atoms or 7 to 40 carbon atoms
B is an aryl group or an alkylaryl group, and when B is an alkyl group or an alkylaryl group, it may have a linear or branched side chain. Me is an alkali metal or alkaline earth metal, and Na and K are particularly preferred. Such a sulfonic acid compound need not be a single compound, but may be a mixture of sulfonic acid compounds having various alkyl groups or alkylaryl groups, for example.

Preferred specific examples of such sulfonic acid compounds include stearyl sulfone*na + octylsulfonic acid 1 (a
, 12Na dodecylsulfone, a mixture of Na alkylsulfonates having an average carbon gfi of 14, and Na dodecylbenzenesulfonate.

The above-mentioned phosphorus compound and sulfonic acid compound can be produced by any method. For example, monomethyl di-sodium phosphate is easily produced by heating trimethyl phosphate, dimethyl phosphate, or monomethyl phosphate and sodium acetate in glycol, and each is added during polyester synthesis and reacted in the polyester reaction system. It can also be manufactured by In addition, benzenesulfonic acid Na -3,5-
Di(Mg carboxylate + Ka) can be easily produced, for example, by subjecting Na 3,5-di(carboxy)benzenesulfonate to a heating reaction with magnesium acetate or magnesium hydroxide in glycol or water.

The above-mentioned phosphorus compound or sulfonic acid compound may be added to the polyester at any stage before the end of the spinning process of melt-spinning the polyester into fibers. They may be mixed or may be mixed after the completion of synthesis and before melt spinning.

A phosphorus compound represented by the general formula (I) or the general formula (I
The blending amount of the sulfonic acid compound represented by [l] is 0.3 to 0.3 to the acid component constituting the polyester to be added.
The range of 15% mole is suitable, and the range of 0.5 to 5% mole is preferable, and the amount of the sulfonic acid compound represented by the general formula (W) in the polyester is
The range of 0.1 to 40 parts by weight is appropriate, and the range of 0.3 to 5 parts by weight is particularly preferable.

Furthermore, as the water absorption pore forming agent used in the present invention, in addition to those mentioned above, the following inert inorganic fine particles are preferably used. In the present invention, inert inorganic fine particles mean inorganic fine particles that do not inhibit the polyester synthesis reaction, do not cause extreme coloring during polyester synthesis, are substantially insoluble in polyester, and among such inorganic fine particles, silicon-containing Inorganic fine particles 1 Inorganic fine particles made of oxides and/or salts of metals from Group 1 of the periodic table, fine particles of aluminum oxide, copper oxide, stannic oxide, thorium oxide, and zirconium oxide are particularly preferred as water absorption pore-forming agents.

The above-mentioned silicon-containing inorganic particles are inorganic fine particles that contain more than 20% silicon by weight as silicon oxide when heated at about 500°C, and specifically, they are particles obtained by crushing naturally occurring rough stones. Examples of such materials include mica, talc, kaolin, glass powder, zirconium silicate, and silicon oxide, regardless of whether they are synthesized or surface-treated.

In addition, the inorganic fine particles made of oxides and/or salts of group (III) metals include Be, M, which are elements of group (III) of the periodic table.
g, Oa, dayr, Ba, Zn, OeL oxides, sulfides, carbonates, sulfates, sulfites, phosphates,
It can be selected from birophosphates, polyphosphates, phosphites and titanates, with preferred examples being beryllium oxide, magnesium oxide, calcium oxide and strontium oxide.

Oxides such as barium oxide and zinc oxide, calcium sulfide,
Strontium sulfide, barium sulfide.

Sulfides such as zinc sulfide, carbonates such as magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, zinc carbonate, cadmium carbonate, magnesium sulfate, calcium sulfate r sulfate.

Sulfates such as sodium chloride, barium sulfate, sulfites such as magnesium sulfite, calcium sulfite, strontium sulfite, barium sulfite, phosphates such as magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, zinc phosphate, viroline Magnesium acid, calcium pyrophosphate, strontium birophosphate.

Throat salts such as barium pyrophosphate and zinc birophosphate, polyphosphates such as calcium polyphosphate, magnesium phosphite, calcium phosphite, strontium sulfite, barium phosphite, zinc phosphite, etc. Examples include acid salts and titanates such as magnesium titanate, calcium titanate, stolone titanate, tium, barium titanate, and zinc titanate.

Among these, magnesium oxide, zinc oxide, zinc sulfide,
Calcium carbonate, strontium carbonate 1 m.

Particularly preferred are barium carbonate, calcium phosphate, calcium phosphite, calcium pyrophosphate, calcium polyphosphate, magnesium titanate, calcium titanate, barium titanate, and zinc titanate.

These inert inorganic fine particles are classified by generally well-known methods such as natural sedimentation, centrifugation, and air sieve classification to prevent problems such as sand clogging or fiber breakage during the melt spinning process. However, excluding coarse particles, particles whose average particle size is adjusted to preferably 7 μm or less, particularly preferably 5 μm or less are used. Here, the average particle size is 50% by weight of all measured particles.
It means the "# spherical diameter" of the particle at the point. "Equivalent spherical iK diameter" refers to the diameter of an imaginary sphere with the same volume as the particle, 7 and can be calculated from electron micrographs of the particle or measurements by conventional sedimentation methods.

The appropriate amount of inert inorganic fine particles is 0.1 to 20 parts by weight per 100 parts by weight of polyester, especially 0.1 to 20 parts by weight per 100 parts by weight of polyester.
．． A range of 3 to 5 parts by weight is preferred.

Such inert inorganic fine particles are preferably dispersed in glycol, alcohol, water, etc., and can be added at any stage until the polymerization reaction is completed.

The organic compound used in combination with the water absorption pore forming agent described above in the present invention is (substantially stable under the melting conditions of the polyester, for example, at a temperature between the melting point of the polyester and 2°C, non-reactive with the polyester, and When mixed with polyester, it must be uniformly compatible without causing phase separation.Here, “substantially stable and non-reactive with polyester” means that it itself “decomposes”. It also means that it does not degrade polyester or react with polyester.

The organic compound is further defined as (2) a compound that does not cause phase separation with polyester and remains uniformly compatible even when the homogeneous melt obtained by melt-mixing with polyester is cooled and solidified. It is necessary that For example, when the homogeneous transparent melt is cooled at a cooling rate sufficient to give a non-quality solid, a uniform transparent solid can be obtained, or phase separation can occur and an opaque solid can be obtained. It is easier to judge by looking at whether K is given.

Further, the organic 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 organic compound is lower than 100° C., when melt-mixed with polyester, the secondary transition point of the polyester will be significantly lowered, making handling during spinning difficult.

The organic compound used in the present invention is under the above conditions (1) to
Any material may be used as long as it satisfies (4), but from the viewpoint of preventing volatilization during melt-mixing, those having a boiling point at latent pressure of 250° C. or higher, particularly 300° C. or higher are preferably used.

The organic compound used in the method of the present invention may be one that satisfies the above conditions, and examples thereof include an imide compound represented by the following general formula (V) 1 and the following general formula (M) 0 0 . Examples include imide compounds represented by 1+ 11 111 0 0 .

The compound of the above formula (V) is a compound in which at least one of AI and R1 in the above formula (v) is an optionally substituted aromatic residue, especially a compound in which A1 is divalent.
Compounds which are optionally substituted aromatic residues are preferably used.

In addition, as a compound of the above formula (■), the above formula (■)
A compound in which R1 is a monovalent, optionally substituted aliphatic residue is preferably used.

In the above general formula (V), the divalent aromatic residue representing A1 is, for example, a 1,2-7 enylene group, 1.2
Examples of divalent aliphatic residues include linear alkylene groups such as ethylene or trimethylene or i1,2-cyclohexylene groups. Examples include cycloargylene groups such as

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, methoxy,
Lower alkoxy groups such as ethoxy, chlorine atoms such as chlorine and bromine, nitro groups, phenyl groups, phenoxy, 4
．． Examples include a cyclohexyl group which may be substituted with a methyl group.

The zero-valent (n-1 or 2) □ aromatic residue representing R1 includes, for example, a monovalent aromatic residue such as a phenyl group, a naphthyl group -8ow- or -0H1-,
．． 2-phenylene group 1'+2-12.3- or 1.
Divalent aromatic residues such as 8-naphthylene group or -0H1-) group can be mentioned, and zero-valent (n-1
Or as the aliphatic residue/group of 2), for example, methyl, ethyl.

1 carbon number such as butyl, hexyl, heptyl, octyl, nonyl, decyl, dodel/l, myridityl, stearyl
~18 chain alkyl groups, 5- or 6-membered cyclic alkyl groups such as cyclohexyl and cyclopentyl, and chain alkylenes having 2 to 12 carbon atoms such as ethylene, trimegolene, tetramethylene, hexamethylene, octamethylene, decamethylene, and dodecamethylene. Basically, I can do it.

These groups representing R1 may be substituted with the same substituents as described for AI.

In the above formula (■), the tetravalent aromatic residue representing A' is preferably a monocyclic, condensed ring, or polynomial tetravalent aromatic group represented by, for example.

The monovalent chain or cyclic aliphatic residue representing Ut includes the same chain alkyl group having 1 to 18 carbon atoms as exemplified for R1 in formula (V) above, or a 5- or 6-membered cyclic alkyl group. I can give you the basics. The groups exemplified above for A1 and R' may be substituted with the same substituents as described for A'.

Examples of the imide compound represented by the above formula (V) include N-methyl phthalimide, N-ethyl 7-thallimide, N-butyl 7-thallimide, N-ethyl-1, 8-7 tarimide, N-butyl-1,8-naphthalimide, etc.; n=
The compounds in case 2 are N,N'-ethylenebisphthalimide and N,N'-tetramethylenebisphthalimide.

N,N'-hexamethylene bisphthalimide.

N,N'-octamethylenepisphthalimide.

N, N'-7'camethylene bisphthalimide, N, N
'-Dodecamethylene bis-7 tar imite, N, N'
- Neobenzene bis-7 tarimide, N,N'-tetodimethylene pis (1,8-su-7 tarimide).

N,N'-hexamethylenebis(1,8-naphthalimide), N,N'-octamethylenebis(1,8-
Naphthalimide) + N+N'-decamethylene bis(II8-7 tarimide) * NUN'-dodecamethylene bis(1,8-7 tar imide)
' * N+N'-dodecamethylene bissuccinimide, N,N'-dodecamethylene bishexahydrophthalimide, N+N'-1t4-cyclohexylene bis7-thallimide, 1-7 tarimido 3-phthalimidomethyl-3, 5,5-trimethylchlorohexane, 4.
4'-bisphthalimidiphenyl ether, 3.4
'-bisphthalimide diphenyl ether, 3.3'
-Bis 7 tarimido diphenyl sulfone, 4.4'-
Examples include bis-7-talimido-diphenyl sulfone and 444'-bis-phthalimido-siphenylmethane.

Examples of the imide compound represented by the above formula (W) include N,N'-diethylpyromellitimide.

N,N'-diethylpyromellitimide, N,N'-diethylpyromellitimide, N,N'-diokdirubyp
Meritimide, N,N'-didecylpyromellitimide, N,N'-dicyclohexylpyromellitimide,
N,N'-bis(3,3,5-)limethylcyclohexyl)pyromellitimide 1NIN'-diethyl-1,4
,5,8-naphthalenetetracarboxylic acid 1.8-,4
．． 5-diimide etc. can be raised.

The imide compounds represented by the above formulas (V) and (M) can be easily produced from the corresponding acid anhydrides and organic amines by known methods.

The above organic 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 raw materials of the polyester, or it may be added during the synthesis of the polyester. 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 organic compound added is too small, the effect of improving the water absorption and hygroscopicity and visual color density of the final polyester fiber will be insufficient; The effects of improving water absorption and hygroscopicity and visual color saturation did not show any significant improvement, and on the contrary, the abrasion resistance and durability deteriorated, and the melt viscosity of the polyester composition significantly decreased, making melt spinning difficult. Therefore, the amount of organic compound added to Polyvarnish T is 0.00 parts by weight per 100 parts by weight of polyester.
A weight range of 1 to 30 parts by weight is preferred, and a range of 25 to 20 parts by weight is preferred.

There is no need to adopt any special method to melt-spun the polyester blended with the water-absorbing pore-forming agent and organic compound obtained in this way into fibers, and any ordinary melt-spinning method for polyester fibers can be used. will be adopted. 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 some of the polyester fiber thus obtained, it is necessary! After applying stretching heat treatment 9 strong twisting or false twisting processing, etc. according to can be done.

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. In addition, alkaline solubility promoters such as cetyltrimethylammonium bromide, lauryldimethylbenzylammonium chloride, etc. can be used as appropriate.

The amount of the alkaline compound eluted and removed by the water-soluble treatment should be in the range of 2% by weight or more based on 1 fl:K of the fiber type. By treating with an aqueous solution of alkaline compounds, special water absorption pores and micropores can be formed, resulting in excellent water absorption and hygroscopicity, and improved color depth when dyed. .

Note that the polyester fiber obtained by the method of the present invention can be appropriately subjected to known post-hydrophilization processing.

Examples of such post-hydrophilization processing include a terephthalic acid component and/or an isophthalic acid component, and a lower alkylene glycol component.

Preferred treatments include treatment with an aqueous dispersion or solution of a polyester polyether polyester copolymer consisting of three or four polyalkylene glycol components. In the case of the polyester fiber produced by the method of the present invention, the initial performance after such post-processing and the washing durability of the performance are superior to those of ordinary polyester fiber.

In addition, the polyester fiber obtained by the method of the present invention includes:
Optional additives as necessary, such as catalyst 1 color inhibitor,
Heat resistant agents, flame retardants, fluorescent whitening agents, matting agents, colorants, etc. may also be included.

Further explanation will be given below with reference to Examples. In Examples, parts and t indicate parts by weight and t% by weight, and the water absorption, hygroscopicity, depth of color when dyed, and friction discoloration of the resulting polyester fibers were measured by the following methods.

(1) Water absorption rate test method (31st - according to L1018) The fibers are made into a cloth, and the cloth is soaked in a 0.3% aqueous solution of anionic detergent Zabu (manufactured by Kao Soap Co., Ltd.) at 40°C in a household electric washing machine. Repeat washing for 30 minutes a specified number of times, then dry.
The sample obtained by drying is stretched horizontally, one drop of water (0.04 CC) is dropped from a height of 1 cm above the sample, and the time required until the water is completely absorbed by the sample and no reflected light is observed is measured. Measure.

(11) Water absorption measurement method A sample □ obtained by drying a fabric is immersed in water for 30 minutes or more, and then dehydrated for 5 minutes using a dehydrator of a household electric washer. It was calculated using the formula F from the weight of the dry sample and the weight of the sample after dehydration.

10 Deep color depth As a measure of the depth of color, bathochromicity (K/S) was used. This value is the spectral reflectance (R) of the sample cloth using the Shimadzu RO
It was measured using a -330 type self-recording spectrophotometer and calculated from the Kubelka-Munk equation shown below. The larger this value is, the greater the deep color effect is.

(Measurement wavelength s o om/I) Note that K represents an absorption coefficient and S represents a scattering coefficient.

(iv) Friction discoloration resistance Using a single-oscillation flat abrasion machine for friction fastness testing, the test cloth was abraded a specified number of times under a load of 500 f, using a georgette made of 100 pieces of polyethylene terephthalate as the friction cloth. The degree of discoloration was determined using a gray scale for discoloration and fading. 1 for extremely low wear resistance
If it is extremely high, it is classified as grade 5. For practical purposes, a grade 4 or above is required.

100 parts of dimethyl terentate, 6 parts of ethylene glycol
0 parts and 0.06 parts of calcium acetate monohydrate were charged into a transesterification tank, and the temperature was raised from 140°C to 230°C over a period of 14 hours in a nitrogen gas atmosphere. Transesterification was carried out while distilling the generated methanol out of the system. The reaction was carried out. Subsequently, trimethyl phosphate o, o'-a part and 0.04 part of antimony dioxide were added to the obtained reaction product, and then + water absorption di(
Mgt/l) of 10% ethylene glycol
After adding 10 parts of a water mixed solution (ethylene glycol: water - 5sJxs), the mixture was transferred to a polymerization can. Next, the temperature was raised from 760#nIIg to 1285°C over 1 hour at G.

Polymerization was carried out for a further 3 hours at a polymerization temperature of 285° C. for a total of 4 hours and 30 minutes under reduced pressure of less than 100° C. to obtain a polymer having an intrinsic viscosity of 0.650 and a softening point of 261° C. After the reaction was completed, the polymer was made into chips according to a conventional method.

A predetermined amount of the organic compound shown in Table 1 was triblended to 100 parts of this chip, and then the resultant product 1. ．． The mixture was placed in a spinneret with a width of 0.05 mm. 24 spinning holes each having an arc-shaped opening with two closed circular slits each having a WM1 diameter of 0.6 mm.
A multifilament consisting of hollow fibers with 75 denier/24 filaments and a hollow ratio of 15% was obtained by melt spinning at 275° C. and then drawing at a draw ratio of 3.5 times according to a conventional method. . This multifilament was knitted into a knitted fabric, scoured by a conventional method, prescented, and then treated with a -3.5% aqueous sodium hydroxide solution at boiling temperature to obtain a fabric with a weight loss rate of 7%.

This fabric is DlaniX Black H (J-Fs (
Mitsubishi Chemical Industries, Ltd. product) 6 at 130℃ at 15thowf
After staining for 0 minutes, dyeing was carried out at 70°C for 2 hours in an aqueous solution containing 11/L of sodium hydroxide and 12/L of hydrosulfite.
A black fabric was obtained by light washing for 0 minutes.

Water absorption rate of this fabric, water absorption rate 1 color depth and abrasion 200
The friction discoloration resistance after washing was as shown in Table 1.

In addition, FIG. 1 is a photograph of the surface of the fibers constituting the knitted knitted fabric after the alkali treatment obtained in Example 1, magnified 2500 times.

Example 7 Benzenesulfonic acid Ha-3,5-di(carboxylic acid Mg+/l) used as a water absorption pore forming agent in Example I
The same procedure as in Example 1 was carried out except that 1 part of monomethyl di-Na phosphate was used in place of ). The results are shown in Table 1.

Example 8 100 parts of dimethyl terentate, s,s-(carbomethoxy)benzenesulfonic acid Nax 7. Part s (11.7 mol % based on dimethyl terephthalate), 70 parts of ethylene glycol.

0.03 part of manganese acetate tetrahydrate and 0.3 part of IJium acetate trihydrate were placed in a transesterification tank, and the temperature was raised from 140°C to 230°C over 4 hours, and the methanol produced was distilled out of the system. The transesterification reaction was carried out while removing the ester. Subsequently, 0.0% of a 56% aqueous solution of orthophosphoric acid was added to the resulting reaction product.
0.03 parts of antimony trioxide and 0.04 parts of antimony trioxide were added and transferred to a polymerization can. Next, the pressure was reduced from 11g of 760M to 1-(g over 1 hour, and at the same time 230M was reduced over 1 hour and 30 minutes.
The temperature was raised from °C to 280 °C. 1mm 1l! ? Polymerization was further carried out for 30 minutes and 42 hours at a polymerization temperature of 280°C under the following reduced pressure to obtain a copolymer having an intrinsic viscosity of 0.405 and a softening point of 200°C.

15 parts of chips of this copolymerized poly-i- and the intrinsic viscosity of 0.71
0 polyethylene terephthalate chips with 85 pieces of polyethylene terephthalate were mixed for 5 minutes in a Nauta mixer (manufactured by Sokyou Iron Works), and
After drying at 10°C for 2 hours and further at 150°C for 5 hours, the mixture was melt-kneaded at 275°C using a twin-screw extruder to form chips.

Using this polymer, 1-7 thalimido 3-7 thalimidomethyl 3.5.5-
) Tri-blending with remethylcyclohexane, melt spinning, stretching, knitting, alkali weight reduction treatment, dyeing, and reduction cleaning were performed. The results are shown in Table 1.

Example 9 ・Benzenesulfonic acid Na-3,5-di(carboxylic acid Mg+/l) used as a water absorption pore forming agent in Example 1
The same procedure as in Example 1 was carried out, except that 20 parts of a 10 ethylene glycol slurry of precipitated barium sulfate having an average primary particle size of 0.6 μm was used in place of the sample. The results were as shown in Table 1.

Comparative Examples 1 to 4 Organic compounds used in Examples 1.7.8 and 9 (
Example 1, respectively, except that imide compound) was not used.
7. The same procedure as in 8 and 9 was carried out. The results are shown in Table 1.

Comparative Example 5 The same procedure as in Example 1 was conducted except that Na-3,5-di(carboxylic acid + C) benzenesulfonic acid Na-3,5-di (carboxylic acid Mg + C) used as the water absorption pore forming agent in Example 1 was not used. The results are shown in Table 1.

[Brief explanation of drawings]

FIG. 1 is an electron microscope photograph showing the surface of a polyester fiber according to the method of the present invention, magnified 2500 times. Procedural amendment dated August 1980, Director General of the Patent Office 1, Indication of the case, Patent Application No. 125868, 1982, Name of the invention, Process for manufacturing water-absorbing polyester fibers 3, Person making the amendment, Relationship with the case, Special ¥r. Applicant 1-11 Minamihonmachi, Higashi-ku, Osaka (300) Teijin Ltd. Representative Tomoo Tokusue 6 Contents of the amendment (1) 1 oxide on page 3, line 10 of the specification The text "Lium oxide" has been corrected to "Thorium oxide." (:2) On page 5, line m12, I added the word ``condemned'' to 1.'' U corrected. (3) Same g 2571 13th line K rQ-zl-Q-
, J is heated and pressed into IQ-21-/LyJ. (4) On page 27, line 16, correct the text ``1-], 8-7 coolimide'' to ``1''-1,8-naphthalimide''. 2 2-

Claims (1)

[Claims] 1. Melt-spinning polyester blended with a water absorption pore-forming agent and an organic compound satisfying the following conditions (1) to (4), and treating the obtained polyester fiber with an aqueous solution of a wofulkali compound. 1. A method for producing water-absorbing polyester fibers, characterized in that at least 2 parts by weight of the fibers are eluted in 1 to 2 parts by weight. (1) Substantially stable under the melting conditions of the polyester, non-reactive with the polyester, and compatible with the polyester. (2) No phase separation occurs when the molten mixture with the polyester is cooled and solidified. (3) The melting point is 100°C or higher. (4) 1° with a molecular weight of 1000 or less