JP2020165027A - Sea-island type conjugate fiber - Google Patents

Abstract

To provide a sea-island type conjugate fiber capable of restricting emission of an organic waste liquid containing a heavy metal or a harmful ash content, easily forming a conjugate fiber cross section, and removing a readily soluble polymer in a short time.SOLUTION: The sea-island type conjugate fiber is a conjugate fiber formed of a polyester component A used as a sea component or an island component and a polymer B different from A, and has a cross-sectional shape where the polymer component B is divided into several portions by the component A or the component A is divided into several portions by the component B. The component A is a copolymerized polyester composition obtained by copolymerization of polyoxyalkylene glycol having a number-average molecular weight of 400-30000, a hindered phenol compound and diethylene glycol with a polyester to which a compound containing a basic metal sulfoisophthalate group has been copolymerized, which can be removed by using an alkali aqueous solution or hot water. The component A is a polyester that uses a titanium compound as a polymerization catalyst and does not contain the heavy metal.SELECTED DRAWING: None

Description

The present invention relates to a sea-island type composite fiber. More specifically, the present invention relates to the production of ultrafine fibers obtained by extracting and removing sea components from sea-island type composite fibers and porous fibers obtained by extracting and removing island components by treating with an alkaline aqueous solution or hot water. The present invention relates to an environment-friendly sea-island type composite fiber capable of easily and efficiently providing ultrafine fibers or porous fibers and reducing heavy metal components contained in an alkaline aqueous solution or a waste liquid of hot water.

Conventionally, a split-type composite fiber in which an alkali-soluble component is arranged so as to divide an alkali-insoluble component (or an alkali-insoluble component) into a plurality of parts is prepared by removing the alkali-soluble component. It is widely known that ultrafine fiber threads can be obtained, and that a cloth having a silky texture can be obtained by alkali-treating the composite fiber after forming the cloth (for example, Patent Documents 1, 2, and 3). See 4.). As the alkali-soluble component, sulfoisophthalic acid metal salt copolymerized polyethylene terephthalate, and further, a polyester polymer copolymerized with polyalkylene glycol is used. As described in Patent Document 4, a heavy metal such as antimony trioxide is usually used as a polymerization catalyst for an alkali-soluble polyester polymer, but a large amount of wastewater containing a polyester decomposing component and a heavy metal removed by alkali dissolution. There are many unfavorable aspects in terms of environmental conservation such as wastewater treatment and ash treatment after residual inspection incineration, and energy required for volume reduction by increasing the concentration of waste liquid.

It has been proposed to use a titanium compound such as titanium tetrabutoxide as a polycondensation reaction catalyst other than the antimony compound (for example, Patent Document 5). However, when this type of titanium compound is used, the obtained polyester itself is colored yellow, the heat stability of fusion is poor, and the catalytic activity is high, so that the control of molecular weight and melt viscosity is unstable. Therefore, a new problem arises in which the cross-sectional shape of the sea-island type composite fiber becomes unstable. In addition, chemical substances are used to neutralize the alkaline weight loss liquid, the problem of generating organic and inorganic substances generated from polymer decomposition products, and environmentally preferable non-alkaline solvent, non-acidic solvent, and water which is a non-organic solvent. Regarding the technique of eluting with, Patent Document 6 states that the sea component is polyolefin, the island component has an average degree of polymerization of 200 to 500, a degree of saponification of 90 to 99.99 mol%, and a water-soluble heat having a melting point of 160 to 230 ° C. Disclosed is a technique for obtaining porous polyolefin fibers by eluting PVA of islands in hot water containing a solvent in sea-island type composite fibers using plastic polyvinyl alcohol (hereinafter abbreviated as PVA).
However, it is necessary to extract PVA over a long period of time under conditions that give a relatively mechanical impact to the liquid flow dyeing machine, it takes a relatively long time, it is necessary to select an elution process, and the side that does not elute. Depending on the composition of the polymer, sea island formation may be difficult due to interfacial tension (compatibility parameter), melt viscosity difference, melting point difference, etc. (island components are fused and bonded to each other), and control is also difficult. there were.

JP-A-54-138620 Japanese Patent Application Laid-Open No. 1-162825 JP-A-5-9811 JP-A-8-109522 Japanese Unexamined Patent Publication No. 2010-70739 Japanese Unexamined Patent Publication No. 2011-252250

An object of the present invention is to solve the problems of the above-mentioned prior art, to intentionally regulate the discharge of organic waste liquid containing heavy metals and harmful ash with respect to the removal of the easily soluble polymer, and to obtain a composite fiber cross section. It is an object of the present invention to provide a sea-island type composite fiber which is a raw fiber of an ultrafine fiber or a porous fiber, which is easy to form and can efficiently remove an easily soluble polymer in a short time.

As a result of diligent studies in view of the above-mentioned prior art, the present inventors have completed the present invention.

That is, the object of the present invention is
1. 1. A sea-island type composite fiber composed of a polyester component A used as a sea component or an island component and a polymer B different from the polyester component A, and the polymer component B is divided into a plurality of parts by the polyester component A. Alternatively, the polyester component A has a fiber cross-sectional shape divided into a plurality of parts by the polymer component B, and the polyester component A contains a compound containing a metal base of sulfoisophthalate and a total acid component (which constitutes the polyester). 1 to 20 polyoxyalkylene glycols having a number average molecular weight of 400 to 30,000 based on the polyester component A are added to a polyester copolymerized in an amount of 5 to 15 mol% based on (containing a compound containing a metal base of sulfoisophthalate). Remove by weight%, 0.02 to 3% by weight of hindered phenol compound, and diethylene glycol using 0.5 to 25.0% by weight of the polyester component A copolymerized with an alkaline aqueous solution or hot water. A sea-island type composite fiber, which is a copolymerized polyester composition characterized by being capable of being formed, and the polyester component A is a polyester obtained by polymerizing a titanium compound as a polymerization catalyst and containing no heavy metal.
2. The sea-island type composite fiber according to 1 above, wherein the number of islands of the sea-island type composite fiber is 100 to 1,000, and the dissolution rate of the polyester component A in an alkaline aqueous solution or hot water is 200 times or more.
3. 3. The sea-island type composite fiber according to any one of claims 1 and 2, wherein the amount of titanium metal element soluble in the polyester component A is 5 to 120 wt ppm among the titanium compounds contained in the composite fiber.
4. A group in which the polyester component A is a product obtained by reacting a titanium compound represented by the following general formula (I) described later with an aromatic polyvalent carboxylic acid represented by the following general formula (II) or an anhydride thereof. It is achieved by the sea-island type composite fiber according to any one of claims 1 to 3, which is polymerized by a catalytic system substantially consisting of a titanium compound component containing at least one selected from.

According to the present invention, regarding the removal of the easily soluble polymer, the discharge of organic waste liquid containing heavy metals and harmful ash can be intentionally regulated, the composite fiber cross section can be easily formed, and the easily soluble polymer can be efficiently formed in a short time. It is an object of the present invention to provide a sea-island type composite fiber which is a raw fiber of an ultrafine fiber or a porous fiber capable of removing.

An example of a spinneret for a sea-island type composite fiber used for melt spinning of a sea-island type composite fiber bundle of the present invention is shown.

Hereinafter, the present invention will be described in detail. The sea-island type composite fiber of the present invention is a composite fiber composed of a polyester component A used as a sea component or an island component and a polymer B different from the polyester component A, and the polymer component B is based on the polyester component A. It has a fiber cross-sectional shape that is divided into a plurality of pieces, or the polymer component B is divided into a plurality of pieces by the polyester component A.

Here, the polyester component A is a copolymerized polyester obtained by copolymerizing 5 to 15 mol% of a compound containing a metal base of sulfoisophthalate, and further, polyoxyalkylene glycol having a number average molecular weight of 400 to 30,000 based on the polyester component A. A copolymerized polyester composition obtained by copolymerizing 1 to 20% by weight, 0.02 to 3% by weight of a hindered phenol compound, and 0.5 to 25.0% by weight of diethylene glycol based on the polyester component A.
Here, the polyester component A preferably uses ethylene terephthalate as the main repeating unit, and is preferably a copolymerized polyethylene terephthalate. Here, "main" means that it is 80 mol% or more of all repeating units. Further, the copolymerized polyester may be copolymerized in a small amount, preferably 10 mol% or less, of components other than the sulfoisophthalic acid metal salt compound and the polyoxyalkylene glycol.

Here, the metal sulfoisophthalate base includes a group in which a lithium sulfonate group, a sodium sulfonate group, a potassium sulfonate group and the like are bonded to an isophthalate group, and examples of the compound containing the metal sulfoisophthalate base include Examples thereof include 5-lithium sulfoisophthalic acid, 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, and the compounds containing these metal sulfoisophthalate bases are total acid components (sulfos) constituting the copolymerized polyester. It is necessary to be copolymerized in an amount of 5 to 15 mol% based on (including a compound containing a metal base isophthalate). If the copolymerization amount is less than 5 mol%, the solubility of the component A in the alkaline aqueous solution and / or hot water becomes insufficient, and the desired ultrafine fibers or porous fibers cannot be obtained. On the other hand, when it is more than 15 mol%, the heat resistance is remarkably lowered or the melt viscosity is remarkably increased, so that the formation of the sea-island shape becomes non-uniform, the yarn breakage at the time of spinning the composite fiber increases, and the process stability is improved. Inappropriate as it tends to worsen. The copolymerization amount of the compound containing the metal base sulfoisophthalate is preferably in the range of 6 to 14 mol%.

Further, the copolymerized polyester composition used as the polyester component A needs to contain 1 to 20% by weight of polyoxyalkylene glycol having a number average molecular weight of 400 to 30,000. If the number average molecular weight of the polyoxyalkylene glycol is less than 400, a sufficient alkali weight loss rate cannot be obtained, and if it exceeds 30,000, the cost increases, which is not preferable.
Further, when the content of the polyoxyalkylene glycol is less than 1% by weight, a sufficient alkali weight loss rate cannot be obtained, and when the content of the polyoxyalkylene glycol is more than 20% by weight, the heat resistance is lowered. As a result, yarn breakage during spinning of composite fibers tends to increase, and process stability tends to deteriorate, which is inappropriate.

The polyoxyalkylene glycol may be simply contained without being bonded to the polyester component A via a covalent bond, but since it is more preferably copolymerized with the polyester component A, the number average molecular weight is 600 to The range of 10000 is preferable, and the range of 1000 to 6000 is even more preferable. When the polyoxyalkylene glycol is copolymerized, the content is preferably in the range of 1 to 17% by weight, more preferably in the range of 2 to 15% by weight.

Here, examples of the polyoxyalkylene glycol are polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, but polyethylene glycol is particularly preferable from the viewpoint of alkali weight loss rate.
Further, the copolymerized polyester composition used as the polyester component A needs to be copolymerized with diethylene glycol in an amount of 0.5 to 25.0% by weight based on the polyester component A. The diethylene glycol unit referred to here may be a diethylene glycol unit added at the time of manufacturing the polyester component A and copolymerized, or a diethylene glycol component naturally occurring in the polyester component A manufacturing process, and the diethylene glycol unit is defined as 0. In order to make it less than 5% by weight, it is necessary to extremely reduce the productivity of the polyester component A, which is not preferable because it is technically difficult and costly. On the other hand, if it exceeds 25.0% by weight, the yarn breakage during spinning of the composite fiber increases, and the process stability deteriorates. In addition, the heat resistance of the obtained copolymerized polyester is also reduced. It is preferably 0.7 to 22.0% by weight, more preferably 1.0 to 20.0% by weight.

The speed and efficiency of removal of polyester A with an alkaline aqueous solution and removal of hot water, as well as the island-forming property of sea-island fibers, are the molar ratio of metal base sulfoisophthalate, the molecular weight and weight ratio of polyoxyalkylene glycol, and the diethylene glycol. It is appropriately controlled by the balance of the copolymerization ratio and the melt viscosity during spinning, but when it comes to the hot water solubility of polyester, it is preferable that the molar ratio of the metal base sulfoisophthalate is high, and the molecular weight of polyoxyalkylene glycol is high. Is preferably low, and its weight ratio is high, the amount of diethylene glycol is high, and the molecular weight (intrinsic viscosity) of polyester A is preferably low, but the yarn-making process tone and sea-island fiber , The final product after extraction is adjusted appropriately from the aspect of quality.

Furthermore, the copolymerized polyester composition used as the polyester component A needs to contain 0.02 to 3% by weight of the hindered phenol compound. It is preferably contained in an amount of 0.1 to 2% by weight. When the content of the hindered phenol compound is less than 0.02% by weight, the thermal stability is poor, the yarn breakage during spinning of the composite fiber is increased, and the process stability is deteriorated, while exceeding 3% by weight. In this case, the yarn breakage during spinning increases, and the process stability deteriorates. Specific examples of the hindered phenol compound include pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and 3,9-bis {2- [3- [3-]. (3-tert-Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] Undecane {Sumitomo Chemical Industry (Sumitomo Chemical Industry) Same as "Smilizer" GA-80 manufactured by Co., Ltd. }, 1,1,3-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert) -Butyl-4-hydroxybenzyl) benzene, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzene) isophthalic acid, triethylglycol-bis [3- (3-tert- Butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thio- Diethylene-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. Be done. It is also preferable to use these hindered phenol compounds in combination with a thioether-based secondary antioxidant. The method of adding the hindered phenol compound to the polyester is not particularly limited, but a method of adding the hindered phenol compound at an arbitrary stage after the completion of the transesterification reaction or the esterification reaction until the polymerization reaction is completed can be mentioned. ..
In the present invention, the polymer component B is a polyester such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene naphthalate, polybutylene naphthalate, etc., and has an alkali weight loss property with respect to polyester A. As long as the difference in hot water elution is large, the copolymerization may be carried out according to the purpose without affecting the difference in weight loss rate.

The third component (copolymerization component) may be either a dicarboxylic acid component or a glycol component. As the component preferably used as the third component, the dicarboxylic acid component includes aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid, isophthalic acid and phthalic acid, adipic acid, azelaic acid, sebacic acid and decandicarboxylic acid. Alicyclic dicarboxylic acids such as aliphatic dicarboxylic acids and cyclohexanedicarboxylic acids, and glycol components such as trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, hexamethylene glycol, cyclohexanedimethanol, 2,2-bis [4- (2-Hydroxyethoxy) phenyl] propane and the like are exemplified, and these can be used alone or in combination of two or more.
As the polymer component B, other than polyester-based, aliphatic polyamides such as polyamide 6 and polyamide 66, aromatic aliphatic polyamides such as polynonane terephthalamide, high density polyethylene, medium density polyethylene, linear low density polyethylene, Polyesters such as low density polyethylene, isotactic polypropylene, syndiotactic polypropylene, ethylene-propylene-butene copolymer, polybutene 1, polymethylpentene 1, isotactic polystyrene, syndiotactic polystyrene, atactic polystyrene, polyphenylene Polyarylen sulfide such as sulfide, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and other thermoplastic cellulose esters can be arbitrarily selected in addition to polyesters, but utilization of sea-island type composite fibers For this purpose, the dissolution rate of the polyester component A in an alkaline aqueous solution or hot water at 90 ° C. or higher must be 1/200 or less. (That is, the dissolution rate of the polyester component A with respect to the polymer component B in an alkaline aqueous solution or hot water at 90 ° C. or higher must be 200 times or more. If the dissolution rate ratio is less than 200 times, both the sea and the island Dissolves and the uniform island shape or pore shape, or the uniformity of the island diameter or pore diameter is broken. The preferable solubility ratio is 250 times or more, more preferably 500 times or more.

The purpose of the present invention is to elute the polyester component A with an alkaline aqueous solution or hot water to obtain ultrafine fibers composed of the polymer component B, or to obtain porous fibers. , A component may be an island component, or B component may be an island component. The number of islands may be limited depending on the purpose of the final product, but the number of islands per single yarn of the composite fiber is 100 to 1,000, which emphasizes the features of the sea-island type composite fiber and the final product. preferable.

Further, examples of the polymerization catalyst of the polyester component A in the present invention include magnesium compounds, aluminum compounds, calcium compounds and titanium compounds other than heavy metals other than antimony compounds and germanium compounds. In particular, titanium compounds are industrially produced. The synthesis technology of the above compounds is being established, and it is particularly preferably used. The titanium compound referred to here is not an inorganic particle such as titanium oxide, but a titanium compound that is substantially soluble in polyester. More specifically, it is an organic titanium compound, and refers to a titanium compound extracted into a hydrochloric acid layer when polyester is dissolved in orthochlorophenol and then extracted with hydrochloric acid. The amount of titanium metal element soluble in polyester contained in the polyester component A in the present invention is preferably in the range of 5 to 120 ppm by weight. The titanium metal element is a titanium metal element used as the above-mentioned polycondensation catalyst, does not include inorganic particles such as titanium oxide, and is substantially the total amount of the polycondensation catalyst of the polyester component A. Therefore, if the amount of this element is less than 5 ppm, the polymerization activity is insufficient, and if it exceeds 120 ppm, the heat resistance is insufficient. The amount of titanium metal element in the polyester-based composite fiber is preferably in the range of 7 to 100 wt ppm, more preferably in the range of 10 to 70 wt ppm.

The polyester component A in the present invention is polymerized without using a conventionally known heavy metal catalyst.
The titanium compound as the polycondensation catalyst used for polymerizing the polyester component A in the present invention is not particularly limited, and general titanium compounds as the polycondensation catalyst of polyester, for example, titanium acetate or tetra-n- Butoxytitanium and the like can be mentioned, but as shown in Patent Document 5, these relatively high catalytically active ones have unstable polymerization, and it is difficult to control the molecular weight and melt viscosity, and the cross-sectional shape of the multi-island sea-island type composite fiber. Judged that it is not suitable for making the
Therefore, as one preferable form as a polymerization catalyst of the polyester component A, a titanium compound represented by the following general formula (I) and an aromatic polyvalent carboxylic acid represented by the following general formula (II) or an anhydride thereof are used. It is polymerized by a catalytic system substantially consisting of a titanium compound component containing at least one selected from the group consisting of products obtained by reacting with.

［上記式中、Ｒ１、Ｒ２、Ｒ３及びＲ４はそれぞれ同一若しくは異なって、アルキル基又はフェニル基を示し、ｍは１〜４の整数を表し、かつｍが２、３又は４の場合、２個、３個又は４個のＲ２及びＲ３は、それぞれ同一であっても異なっていてもどちらでもよい。］

[In the above formula, R1, R2, R3 and R4 are the same or different, respectively, indicating an alkyl group or a phenyl group, m represents an integer of 1 to 4, and when m is 2, 3 or 4, two. The three or four R2 and R3 may be the same or different, respectively. ]

［上記式中、ｎは２〜４の整数を表わす。］

[In the above equation, n represents an integer of 2-4. ]

Here, as the titanium compound represented by the general formula (I), specifically, tetraisopropoxytitanium, tetrapropoxytitanium, tetra-n-butoxytitanium, tetraethoxytitanium, tetraphenoxytitanium, octaalkyltrititanate, And hexaalkyl dititanate and the like are preferably used. Further, as the aromatic polyvalent carboxylic acid represented by the general formula (II) or its anhydride to be reacted with the titanium compound, phthalic acid, trimellitic acid, hemmellitic acid, pyromellitic acid and their anhydrides are used. It is preferably used.
When the titanium compound is reacted with the aromatic polyvalent carboxylic acid or its anhydride, for example, a part or all of the aromatic polyvalent carboxylic acid or its anhydride is dissolved in a solvent, and the titanium compound is dissolved in this mixed solution. Is dropped and heated at a temperature of 0 to 200 ° C. for at least 30 minutes, preferably at a temperature of 30 to 150 ° C. for 40 to 90 minutes. The reaction pressure at this time is not particularly limited, and normal pressure is sufficient.

As a solvent for dissolving the aromatic polyvalent carboxylic acid or its anhydride, any of ethanol, ethylene glycol, trimethylene glycol, tetramethylene glycol, benzene, xylene and the like can be used as desired.
Here, the reaction molar ratio of the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride is not particularly limited, but if the ratio of the titanium compound is too high, the color tone of the obtained polyester deteriorates or the softening point. On the contrary, if the ratio of the titanium compound is too low, the polymerization reaction may be difficult to proceed. Therefore, the reaction molar ratio of the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride is preferably in the range of 2/1 to 2/5. Further, there is no particular limitation as long as the titanium compound can be reacted with the aromatic polyvalent carboxylic acid or its anhydride under other conditions.

By taking this form, the catalytic activity can be weakened, and the molecular weight distribution of the polyester A, the intramolecular polymerization state, the variation in the melt viscosity, and the like can be made more uniform. Preferably, the form of titanium trimellitic acid is excellent in terms of cost and quality stability.
Further, in polymerizing the polyester component A, the compound represented by the following general formula (I), the titanium compound represented by the following general formula (I), and the aromatic polyvalent represented by the following general formula (II) An unreacted mixture of a titanium compound component containing at least one selected from the group consisting of a product obtained by reacting a carboxylic acid or an anhydride thereof with a phosphorus compound represented by the following general formula (III) is a catalytic system. Can be used more preferably.

［上記式中、Ｒ１、Ｒ２、Ｒ３及びＲ４はそれぞれ同一若しくは異なって、アルキル基又はフェニル基を示し、ｍは１〜４の整数を表し、かつｍが２、３又は４の場合、２個、３個又は４個のＲ２及びＲ３は、それぞれ同一であっても異なっていてもどちらでもよい。］

[In the above formula, R1, R2, R3 and R4 are the same or different, respectively, indicating an alkyl group or a phenyl group, m represents an integer of 1 to 4, and when m is 2, 3 or 4, two. The three or four R2 and R3 may be the same or different, respectively. ]

［上記式中、ｎは２〜４の整数を表わす。］

[In the above equation, n represents an integer of 2-4. ]

［上記式中、Ｒ５、Ｒ６及びＲ７は、同一又は異なって炭素数原子数１〜４のアルキル基を表し、Ｘは、−ＣＨ２−又は―ＣＨ（Ｙ）を表す（Ｙは、ベンゼン環を示す）。］

[In the above formula, R5, R6 and R7 represent the same or different alkyl groups having 1 to 4 carbon atoms, X represents -CH2- or -CH (Y) (Y represents a benzene ring). Show). ]

Here, as the titanium compound represented by the general formula (I), specifically, tetraisopropoxytitanium, tetrapropoxytitanium, tetra-n-butoxytitanium, tetraethoxytitanium, tetraphenoxytitanium, octaalkyltrititanate, And hexaalkyl dititanate and the like are preferably used. Further, as the aromatic polyvalent carboxylic acid represented by the general formula (II) or its anhydride to be reacted with the titanium compound, phthalic acid, trimellitic acid, hemmellitic acid, pyromellitic acid and their anhydrides are used. It is preferably used.
When the titanium compound is reacted with the aromatic polyvalent carboxylic acid or its anhydride, for example, a part or all of the aromatic polyvalent carboxylic acid or its anhydride is dissolved in a solvent, and the titanium compound is dissolved in this mixed solution. Is dropped and heated at a temperature of 0 to 200 ° C. for at least 30 minutes, preferably at a temperature of 30 to 150 ° C. for 40 to 90 minutes. The reaction pressure at this time is not particularly limited, and normal pressure is sufficient.

As a solvent for dissolving the aromatic polyvalent carboxylic acid or its anhydride, any of ethanol, ethylene glycol, trimethylene glycol, tetramethylene glycol, benzene, xylene and the like can be used as desired.
Here, the reaction molar ratio of the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride is not particularly limited, but if the ratio of the titanium compound is too high, the color tone of the obtained polyester deteriorates or the softening point. On the contrary, if the ratio of the titanium compound is too low, the polymerization reaction may be difficult to proceed. Therefore, the reaction molar ratio of the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride is preferably in the range of 2/1 to 2/5. Further, there is no particular limitation as long as the titanium compound can be reacted with the aromatic polyvalent carboxylic acid or its anhydride under other conditions.

The catalytic system used as the polymerization catalyst in the present invention is substantially composed of an unreacted mixture of the above-mentioned titanium compound component and the phosphorus compound represented by the general formula (III), and the phosphorus compound includes Carbomethoxymethanephosphonic acid, carboethoxymethanephosphonic acid, carbopropoxymethanephosphonic acid, carbobutoxymethanephosphonic acid, carbomethoxy-phosphono-phenylacetic acid, carboethoxy-phosphono-phenylacetic acid, carboprotoxy-phosphono-phenylacetic acid and carbo It is preferably selected from dimethyl esters, diethyl esters, dipropyl esters and dibutyl esters of butoxy-phosphono-phenylacetic acid.

The above-mentioned phosphorus compound proceeds relatively slowly with the titanium compound or the titanium compound component (hereinafter abbreviated as "titanium compound or the like") as compared with the phosphorus compound usually used as a stabilizer. The duration of catalytic activity of the titanium compound or the like during the reaction is long, and as a result, the amount of the titanium compound added to the polyester can be reduced, and when a large amount of stabilizer is added to the catalyst as in the present invention. Even so, it has the property of not impairing the thermal stability of polyester.

At least one selected from the group consisting of a product obtained by reacting a titanium compound represented by the general formula (I) with an aromatic polyvalent carboxylic acid represented by the general formula (II) or an anhydride thereof. Ratio m of titanium atom equivalent molar amount m _Ti and phosphorus atom equivalent molar amount m _{P in} a catalyst mixture for producing polyester composed of an unreacted mixture of the titanium compound component contained and the phosphorus compound represented by the above general formula (III). _Ti / m _P is preferably in the range of 0.3 to 1.0, preferably 0.5 to 1.0. Here, the titanium atom-equivalent molar amount and the phosphorus atom-equivalent molar amount are the titanium atomic molar amount and the phosphorus atomic molar amount contained in one mol of the catalyst composed of the above-mentioned mixture of the titanium compound and the phosphorus compound. When m _Ti / m _P is larger than 1.0, that is, when the amount of the titanium compound component is excessive, the heat resistance of the polyester obtained by using the obtained catalyst may decrease. Further, when m _Ti / m _P is less than 0.3, that is, when the amount of the titanium compound component is too small, the catalytic activity of the obtained catalyst for the polyester production reaction may be insufficient.
The method for producing the polyester component A used in the present invention is not particularly limited, and is a method in which terephthalic acid is directly esterified with the glycol component and then polymerized, and an ester-forming derivative of terephthalic acid is transesterified with the glycol component. After that, any method such as polymerization may be adopted, but as the compound containing the sulfoisophthalic acid metal base, a dimethyl ester of a sulfoisophthalic acid metal salt which is superior to the transesterification reaction can be obtained at a relatively low cost. , It is cost-effective. Further, in the production method using dimethyl terephthalate as a raw material as an ester-forming derivative of terephthalic acid, a part and / or all of the titanium compound, which can reduce the amount of the titanium compound added, is added before the start of the transesterification reaction. A production method in which two catalysts, an ester exchange reaction catalyst and a polycondensation reaction catalyst, are used in combination is preferable. The transesterification reaction may be carried out under normal pressure reaction or under a pressure of 0.05 to 0.20 MPa.
In the above-mentioned production method using dimethyl terephthalate as a raw material, a polyester is obtained by performing a polycondensation reaction via a transesterification reaction. A calcium compound and / or a magnesium compound can also be used as the transesterification reaction catalyst used here. The calcium compound and magnesium compound referred to here need to be a compound that is active as an ester exchange reaction catalyst. Specifically, the calcium compounds include calcium acetate, calcium sulfate, calcium carbonate, calcium chloride, and calcium benzoate. , Calcium formate, calcium stearate and their hydrates, etc., and magnesium acetate, magnesium sulfate, magnesium carbonate, magnesium chloride, magnesium benzoate, magnesium formate, magnesium stearate and their hydrates, etc. as magnesium compounds, respectively. These may be used alone or in combination of two or more. Of these, calcium acetate monohydrate and magnesium acetate tetrahydrate are particularly preferably used.
In the case of polymerizing the polyester component A after directly esterifying the terephthalic acid with the glycol component, the polymerization can be further carried out using the following catalyst. That is, it depends on a catalytic system substantially composed of the compound represented by the following general formula (IV).

〔上記式中Ｒ８及びＲ９は、それぞれ互いに独立に、２〜１０個の炭素原子を有するアルキル基、又は６〜１２個の炭素原子を有するアリール基を表す〕

[In the above formula, R8 and R9 each independently represent an alkyl group having 2 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms].

It is composed of a catalyst composed of the reactants of the general formula (I) and the general formula (II), the reactant of the general formula (I) and the general formula (II), and the unreacted product of the general formula (III) introduced above. Both the catalyst and the catalyst of the general formula (IV) are easier to control the reactivity than the highly reactive titanium-based catalyst such as titanium tetrabutoxide, and the thermal decomposition of polyester A after polymerization is suppressed. There is little formation of gel foreign matter and deterioration of hue, uniform distribution of copolymerization and molecular weight distribution, no unevenness in melt viscosity, uniform island formation of sea-island type composite fiber, process tone and product quality after removal of polyester A. You can do good things.
The ratio m _Ti / m _P of the titanium atom-equivalent molar amount m _Ti and the phosphorus atom-equivalent molar amount m _{P in} the catalyst for producing polyester of the general formula (IV) is 0.3 to 1.0, preferably 0.5 to 1. It is preferably in the range of 0.0. Here, the molar amount of titanium atom and the molar amount of phosphorus atom are the molar amount of titanium atom and the molar amount of phosphorus atom contained in 1 mol of the catalyst compound of the general formula (IV). When m _Ti / m _P is larger than 1.0, that is, when the ratio of titanium atoms is excessive, the heat resistance of the polyester obtained by using the obtained catalyst may decrease. Further, when m _Ti / m _P is less than 0.3, that is, when the ratio of titanium atoms is too small, the catalytic activity of the obtained catalyst for the polyester production reaction may be insufficient.

The polyester component A and the polymer component B used in the present invention may contain, if necessary, a small amount of additives such as lubricants, pigments, dyes, antioxidants, solid phase polymerization accelerators, optical brighteners, antistatic agents. It may contain an antibacterial agent, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a light shielding agent, a matting agent and the like.
In order to produce the sea-island type polyester composite fiber of the present invention described above, a conventionally known composite spinneret and composite spinner can be used, and any yarn-making conditions can be adopted without any trouble. For example, a method of melt-spinning at a speed of 500 to 2500 m / min, winding once, then drawing and heat-treating, a method of melt-spinning at a speed of 500 to 2500 m / min, stretching and heat-treating without winding once, 1000 Any method such as a method of melt-spinning at a speed of ~ 5000 m / min and performing drawing and false twisting at the same time or continuously, a method of melt-spinning at a high speed of 5000 m / min or more and omitting the drawing step depending on the application, etc. Spinning conditions can be adopted. Further, the obtained fiber or a woven or knitted product produced from the fiber may be heat-treated at a temperature of 100 ° C. or higher to improve the stability of the structure, and if necessary, relaxation heat treatment or the like may be used in combination. ..
The polyester composite fiber of the present invention preferably has a fiber cross-sectional shape in which the polymer component B is completely covered with the polyester component A.

The sea-island type composite fiber can be made into a fabric and then treated with alkali or hot water to remove only the polyester component A and form an ultrafine fiber of the polymer component B. At the same time, a space can be provided between the fibers, which is suitable for obtaining a fabric having a bulky and soft texture. Here, in order to carry out the alkali treatment, for example, a method of keeping an aqueous solution of sodium hydroxide having a concentration of 10 to 100 g / L at 60 ° C. or higher and immersing the cloth in this solution is usually performed. Further, in order to perform the hot water treatment, for example, a method of immersing the cloth in water having a temperature of 90 ° C. or higher is performed. The treatment time is an appropriate time for removing the polyester component A, usually 0.5 to 30 hours, which can be easily grasped by those skilled in the art. There is no problem whether these processes are performed by batch method or continuous method. After the completion of these treatments, washing, drying and the like can be performed to obtain a fabric containing the above-mentioned ultrafine fibers. In the ultrafine fiber of the present invention, one structural unit (single yarn) composed of only the polymer component B is 0.0001 dtex or more and 0.1 dtex or less (100 nm or more and 3000 nm or less), and the number of the structural units is 16. As described above, particularly when the number of fibers is 24 or more, the obtained effect (exhibiting a bulky and soft texture) becomes remarkable, which is preferable.

On the other hand, in the above case and in the case of making a sea-island type composite fiber in which the polyester component A is an island component and the polymer component B is a sea component, the fabric is made into a cloth and then subjected to alkali treatment or heat, as in the case of the above-mentioned ultrafine fibers. By water treatment, only the polyester component A can be removed to form a porous fiber of the polymer component B. Expected effects include lightweight fabric, hygroscopic liquid absorption (sweat absorption), and flexibility due to the internal porosity.

The composite ratio of the polyester component A and the polymer component B in the sea-island type composite fiber is determined from the viewpoint of achieving both the ease of division by alkali treatment or hot water treatment and the fiber physical properties of the composite fiber (polyester component A: polyester component). B) is preferably in the range of (80:20) to (2:98) in weight ratio, and more preferably in the range of (60:40) to (5:95).

An example of a spinneret for a sea-island type composite fiber used for melt spinning of a sea-island type composite fiber bundle of the present invention is shown in FIG. 1, and an explanation will be added. Appropriate ones such as those having a hollow pin group and a micropore group for forming an island component can be used. For example, the island component extruded from a hollow pin or micropores and the sea component flow supplied from a flow path designed to fill the space between them are merged, and this combined fluid flow is extruded from the discharge port while gradually narrowing. Any spinneret may be used as long as it can form a sea-island type composite fiber.

In the spinneret 1 shown in FIG. 1, the island component polymer (melt) in the distribution front island component polymer reservoir 2 is distributed in the island component polymer introduction path 3 formed by a plurality of hollow pins. On the other hand, the sea component polymer (melt) is introduced into the pre-distribution sea component polymer reservoir 5 through the sea component polymer introduction passage 4. The hollow pin forming the island component polymer introduction path 3 penetrates the sea component polymer reservoir 5, and is the center of each inlet of the plurality of core-sheath type composite diversion passages 6 formed below the hollow pin. The portion is open downward. From the lower end of the island component polymer introduction path 3, the island component polymer flow is introduced into the central portion of the core-sheath type composite diversion passage 6, and the sea component polymer flow in the sea component polymer reservoir 5 is a core-sheath type. A core-sheath type composite flow is introduced into the composite diversion passage 6 so as to enclose the island component polymer flow, and the island component polymer flow is the core and the sea component polymer flow is the sheath, and a plurality of core-sheath type composite flows are formed. It is introduced into the funnel-shaped merging passage 7, and in the merging passage 7, the sheath portions of the plurality of core-sheath type composite flows are joined to each other to form a sea-island type composite flow. While flowing down the funnel-shaped merging passage 7, the sea-island type composite flow gradually decreases its horizontal cross-sectional area and is discharged from the discharge port 8 at the lower end of the merging passage 7.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Each value in the examples was obtained according to the following method.
(1) Intrinsic viscosity of polyester A:
The measurement was carried out at 35 ° C. using a mixed solution of phenol: 1,1,2,2,-tetrachloroethane (mass ratio 60:40) as a solvent.
(2) Amount of diethylene glycol:
The sample was decomposed using hydrazine hydrazine (hydrazine hydrazine), and the amount of diethylene glycol was quantified by using gas chromatography (HP6890 Series GC System, manufactured by HEWLETT PACKARD). From the quantitative value, the copolymerization amount of diethylene glycol based on the measured weight of the polymer was determined by weight percentage.
(3) Polymer color tone (color L value and color b value):
The polymer chip was dried and crystallized at 130 ° C. for 1 hour, and then measured using a colorimetric color difference meter Z-1001DP manufactured by Nippon Denshoku Industries Co., Ltd. The L value indicates the brightness, and the larger the value, the higher the brightness, and the larger the b value, the greater the degree of yellowness. Other detailed measurement methods were performed according to JIS Z-8729.
(4) Titanium atom and phosphorus atom contents of polyester component A in the composite fiber:
Only the polyester component A was removed from the composite fiber sample using a 35 g / L sodium hydroxide aqueous solution at 90 ° C. The sodium hydroxide aqueous solution containing the removed polyester component A was quantified using a Z-8100 type atomic absorption spectrophotometer manufactured by Hitachi, Ltd.
(5) Composite fiber cross-sectional shape:
The composite fiber discharged from the spinneret for Kaijima type composite fiber (Discharge port 8 in FIG. 1) is cut with a sword, and the cross-sectional shape of the fiber is observed using a scanning electron microscope S-3500 manufactured by Hitachi, Ltd. The state of island formation was evaluated as follows.
・ "Good" when the components that have become islands do not adhere to each other and the islands are formed uniformly.
・ When there are 1 or 2 places where two or more islands are in close contact with each other "Slightly defective"
・ If there are two or more islands in close contact with each other in three or more places, or if no islands are formed, "defective"
(6) Method for measuring the content of a compound containing a metal base of sulfoisophthalate:
After the obtained copolymerized polyester composition is heated and melted on an aluminum plate, a test molded product having a flat surface is prepared by a compression press, and a fluorescent X-ray apparatus (3270E type manufactured by Rigaku Denki Kogyo Co., Ltd.) is used. The content of the sulfur element was measured to determine the molar percentage of the total acid component.
(7) Content of polyoxyalkylene glycol and hindered phenol compound:
After dissolving the polymer sample in deuterated trifluoroacetic acid / deuterated chloroform = 1/1 mixed solvent, nuclear magnetic resonance spectrum ( ¹ H-) using JEOL A-600 superconducting FT-NMR manufactured by JEOL Ltd. NMR) was measured, and the content of the polyoxyalkylene glycol component and the content of the hindered phenol compound were quantified from the spectrum pattern according to a conventional method.

[Reference example 1]
Adjustment of Titanium Trimellitic Acid (TMT):
To a solution of trimellitic anhydride (0.2%) in ethylene glycol (0.2%) was added 1/2 mol of tetrabutoxytitanium to trimellitic anhydride, and the mixture was kept at 80 ° C. under normal pressure in air for 60 minutes. Then, the mixture was cooled to room temperature, the production catalyst was recrystallized from 10 times the amount of acetone, the precipitate was filtered through a filter paper, and dried at 100 ° C. for 2 hours to obtain the desired catalyst.

[Reference example 2]
Manufacture of polymers for polyester component A:
A mixture of 97.5 parts of dimethyl terephthalate, 3.8 parts of dimethyl 5-sodium sulfoisophthalate, and 65 parts of ethylene glycol, 0.017 parts of tetra-n-butyl titanate (hereinafter abbreviated as TBT), and 0 parts of sodium acetate. .109 parts were charged in a reactor equipped with a stirrer, a rectification tower and a methanol distilling condenser, and the temperature was gradually raised from 140 ° C., and the methanol produced as a result of the reaction was distilled out of the system at 240 ° C. The temperature was raised to 1 and the transesterification reaction was carried out.
Next, 11 parts of polyethylene glycol having a number average molecular weight of 4000 and 0.30 part of a hindered phenol compound (“Smilizer” GA-80 manufactured by Sumitomo Chemical Industries, Ltd.) were added to the obtained reaction product, and a stirrer and glycol were added. The compound was transferred to another reactor provided with a distillation condenser, and the temperature was gradually raised from 240 ° C. to 285 ° C., and the polymerization reaction was carried out while lowering the pressure to a high vacuum of 70 Pa or less. While tracing the melt viscosity of the reaction system, the polymerization reaction was terminated when the intrinsic viscosity reached 0.39.
The molten polymer was extruded into the cooling water in a strand shape from the bottom of the reactor and cut into chips using a strand cutter. As a result of analyzing the obtained copolymerized polyester, the hindered phenol compound was contained in an amount of 0.3% by weight. Other results are shown in Table 1.

[Reference example 3]
Manufacture of polymers for polyester component A:
In Reference Example 2, the same operation was carried out except that the titanium compound was changed to 0.032 part of titanium trimellitic acid (hereinafter abbreviated as TMT) prepared by the method of Reference Example 1 above. The hindered phenol compound was contained in an amount of 0.3% by weight. Other results are shown in Table 1.

[Reference example 4]
Manufacture of polymers for polyester component A:
In Reference Example 3, 0.023 parts of triethylphosphonoacetate (diethyl ethoxycarbonylmethanephosphorus) was added as a phosphorus compound at the end of the transesterification reaction (0.055 parts in total of the titanium compound and the phosphorus compound), and the transesterification reaction was carried out. The same operation was performed except that was terminated. The hindered phenol compound was contained in an amount of 0.3% by weight. Other results are shown in Table 1.

[Reference example 5]
Manufacture of polymers for polyester component A:
In Reference Example 4, 0.010 part of diethylene glycol was added at the end of the transesterification reaction, and the same operation was performed except that the transesterification reaction was terminated. The hindered phenol compound was contained in an amount of 0.3% by weight. Other results are shown in Table 1.

[Reference example 6]
The type of the polyester A polymerization catalyst was the same as that of Reference Example 2 except that the titanium / phosphoric acid-based composite catalyst represented by the general formula (IV) using a butyl group for both R8 and R9. The results are shown in Table 1.

[Examples 1 to 5, Comparative Example 1]
As shown in Table 2, the polymers obtained in Reference Examples 1 to 6 are used as the polyester component A and the polymer component B, and the base of the mold shown in FIG. 1 is used, and the composite ratio of the polyester component A and the polymer component B is used. 30/70 (weight ratio), islands and sea components were simultaneously spun from the composite spinneret to obtain a sea-island type composite undrawn yarn. At that time, the spinning temperature was 290 ° C. and the spinning speed was 1000 m / min. As a result, the total fineness was 230 dtex, the number of filaments was 10, the number of islands in one filament was 800, the weight ratio of the island component was 70%, and the sea component. 30% undrawn yarn was obtained. This composite undrawn yarn was drawn under the conditions of a heating plate temperature of 200 ° C. and a drawing ratio of 4.1 times to obtain a drawn yarn having a total fineness of 56 dtex. Next, the obtained composite fiber was used as a plain woven fabric and subjected to an alkali weight loss treatment of 30% by weight in an aqueous sodium hydroxide solution (concentration 35 g / liter) at a temperature of 90 ° C. to obtain a woven fabric of ultrafine fibers. The results are shown in Table 2.

[Examples 6 to 8]
The same procedure as in Example 5 was carried out except that the polymer B was changed from PET (polyethylene terephthalate) to polyamide 6 (abbreviated as PA6), isotactic polypropylene (abbreviated as i-PP), and polyphenylene sulfide (abbreviated as PPS), respectively. .. The results are shown in Table 2.

[Example 9, Comparative Example 2]
This was carried out in the same manner as in Example 5 and Comparative Example 1, respectively, except that the polyester A and the island component were replaced with the polymer B with the sea component. The same base as in FIG. 1 was used. The results are shown in Table 2.

According to the present invention, it is possible to intentionally regulate the discharge of organic waste liquid containing heavy metals and harmful ash by removing the easily soluble polymer, the composite fiber cross section is easily formed, and the easily soluble polymer can be efficiently produced in a short time. It is possible to provide a sea-island type composite fiber which can be removed and is a raw fiber of an ultrafine fiber or a porous fiber.
A woven or knitted fabric is produced using the composite fibers, and then alkali weight loss or the like is performed to provide a space between the fibers. As a result, the woven or knitted fabric is suitable for obtaining a fabric having a bulky and soft texture and good hygroscopicity and sweat absorption. Further, in the case of a woven or knitted fabric made of porous fibers, a lightweight and heat-insulating fabric can be obtained.

1: Spinning cap 2: Polymer reservoir for island component before distribution 3: Polymer introduction path for island component 4: Polymer introduction passage for sea component 5: Polymer reservoir for sea component before distribution 6: Core-sheath type composite diversion passage 7: Confluence Passage 8: Discharge port

Claims (6)

A sea-island type composite fiber composed of a polyester component A used as a sea component or an island component and a polymer B different from the polyester component A, and the polymer component B is divided into a plurality of parts by the polyester component A. Alternatively, the polyester component A has a fiber cross-sectional shape divided into a plurality of parts by the polymer component B, and the polyester component A contains a compound containing a metal base of sulfoisophthalate and a total acid component (which constitutes the polyester). 1 to 20 polyoxyalkylene glycols having a number average molecular weight of 400 to 30,000 based on the polyester component A are added to a polyester copolymerized in an amount of 5 to 15 mol% based on (containing a compound containing a metal base of sulfoisophthalate). Remove by weight%, 0.02 to 3% by weight of hindered phenol compound, and diethylene glycol using 0.5 to 25.0% by weight of the polyester component A copolymerized with an alkaline aqueous solution or hot water. A sea-island type composite fiber which is a copolymerized polyester composition characterized by being capable of being formed, and the polyester component A is a polyester which is polymerized using a titanium compound as a polymerization catalyst and does not contain heavy metals. The sea-island type composite fiber according to claim 1, wherein the number of islands of the sea-island type composite fiber is 100 to 1,000, and the dissolution rate of the polyester component A in an alkaline aqueous solution or hot water is 200 times or more. The sea-island type composite fiber according to any one of claims 1 and 2, wherein the amount of titanium metal element soluble in the polyester component A is 5 to 120 wt ppm among the titanium compounds contained in the composite fiber. The polyester component A is selected from the group consisting of a product obtained by reacting a titanium compound represented by the following general formula (I) with an aromatic polyvalent carboxylic acid represented by the following general formula (II) or an anhydride thereof. The sea-island type composite fiber according to any one of claims 1 to 3, which is polymerized by a catalytic system substantially composed of a titanium compound component containing at least one of them.

[In the above formula, R1, R2, R3 and R4 are the same or different, respectively, indicating an alkyl group or a phenyl group, m represents an integer of 1 to 4, and when m is 2, 3 or 4, two. The three or four R2 and R3 may be the same or different, respectively. ]

[In the above equation, n represents an integer of 2-4. ] The polyester component A is a titanium compound represented by the following general formula (I), a titanium compound represented by the following general formula (I), an aromatic polyvalent carboxylic acid represented by the following general formula (II), or a polyvalent carboxylic acid thereof. By a catalytic system substantially consisting of an unreacted mixture of a titanium compound component containing at least one selected from the group consisting of products reacted with an anhydride and a phosphorus compound represented by the following general formula (III). The sea-island type composite fiber according to any one of claims 1 to 3, which is a polymer.

[In the above formula, R1, R2, R3 and R4 are the same or different, respectively, indicating an alkyl group or a phenyl group, m represents an integer of 1 to 4, and when m is 2, 3 or 4, two. The three or four R2 and R3 may be the same or different, respectively. ]

[In the above equation, n represents an integer of 2-4. ]

[In the above formula, R5, R6 and R7 represent the same or different alkyl groups having 1 to 4 carbon atoms, X represents -CH2- or -CH (Y) (Y represents a benzene ring). Show). ] The sea-island type composite fiber according to any one of claims 1 to 3, wherein the polyester component A is polymerized by a catalytic system substantially composed of a compound represented by the following general formula (IV).

[In the above formula, R8 and R9 each independently represent an alkyl group having 2 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

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