Polyester resin and method for producing polyester resin

Abstract

To provide a polyester resin that can maintain excellent water repellency even when used for a long time.SOLUTION: A polyester resin comprises a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol, the polyester containing silicone. 90% or more of the silicone is copolymerized with the polyester. In the polyester resin, the content of copolymerized silicone is 1-60 mass%. The inventive polyester resin preferably has an intrinsic viscosity of 0.5-0.8.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyester resin that can maintain good water repellency even when used for a long period of time. [Background technology]

[0002] Polyester resins have excellent properties such as heat resistance, dimensional stability, and mechanical properties, and are therefore widely used in various fields such as fibers, films, molded articles, etc. In order to impart properties such as water repellency, it is known that, for example, fibers, fabrics, etc. made of polyester resins are treated with a dispersion containing a fluorine-based resin or a silicone-based resin as a water-repellent resin, thereby adhering the resin to the surface (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-106171 Summary of the Invention [Problem to be solved by the invention]

[0004] As in Patent Document 1, the water repellency imparted by surface treatment has the drawback of being low in durability, and the water repellency decreases with long-term use, repeated washing, etc. Furthermore, when surface treatment is performed using a resin in an amount that can impart sufficient durability to the water repellency, there is a problem that when the material is made into fibers, films, etc., the texture becomes hard and the touch becomes rough.

[0005] In view of the current situation, an object of the present invention is to provide a polyester resin that, when formed into molded products such as fibers and films, has excellent water-repellent properties without the need for water-repellent treatment and has excellent water-repellent durability (water-repellent durability). [Means for solving the problem]

[0006] The present inventors have conducted extensive research in light of the problems of the prior art and have found that the above object can be achieved if the polyester is copolymerized with silicone in a specific range and the copolymerized silicone has a high reactivity, thereby completing the present invention.

[0007] That is, the gist of the present invention is as follows. (1) A polyester resin containing silicone in a polyester made of an aromatic dicarboxylic acid and an aliphatic diol, wherein 90% or more of the silicone is copolymerized with the polyester, and the content of the copolymerized silicone in the polyester resin is 1 to 60% by mass. and the intrinsic viscosity is 0.5 to 0.8. Polyester resin. (2)(1) Fiber containing polyester resin. (3)(1) A film containing a polyester resin. (4)(1) A molded article containing the polyester resin. (5)(1) A resin solution containing a polyester resin. (6)(1) Powder containing polyester resin. (7) A method for producing a polyester resin by carrying out an esterification reaction and a polycondensation reaction, comprising: adding to a mixture of a polyester raw material and a silicone: A tin-based esterification catalyst was used in an amount of 1 × 10 per mole of the total acid component of the polyester. -5 ~1×10 -4 After the esterification reaction was carried out at a reaction temperature of 250 to 270°C, The polycondensation catalyst was used in an amount of 1 × 10 per mole of the total acid component of the polyester. -5 ~1×10 -4 and carrying out a polycondensation reaction at a reaction temperature of 250 to 270°C. [Effects of the Invention]

[0008] The polyester resin of the present invention is excellent in water repellency and water repellency durability. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. The polyester resin of the present invention is a polyester made from an aromatic dicarboxylic acid and an aliphatic diol, and further contains silicone.

[0010] The aromatic dicarboxylic acid in the polyester resin of the present invention is preferably composed mainly of terephthalic acid. The content of terephthalic acid in the total acid components is preferably 80 mol% or more, more preferably 90 mol% or more. If the content of terephthalic acid is less than 80 mol%, the crystallinity and heat resistance may be poor.

[0011] Examples of the acid component other than terephthalic acid in the polyester resin of the present invention include isophthalic acid, phthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, dodecanedioic acid, dimer acid, etc. Two or more of these may be used in combination, and ester-forming derivatives of these acids may also be used.

[0012] The aliphatic diol in the polyester resin of the present invention preferably contains ethylene glycol as a main component. The content of ethylene glycol in the total aliphatic diols is preferably 80 mol% or more, more preferably 90 mol% or more. If the content of ethylene glycol is less than 80 mol%, the crystallinity and heat resistance may be poor.

[0013] Examples of the aliphatic diol component other than ethylene glycol in the polyester resin of the present invention include diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexamethylenediol, 1,4-cyclohexanedimethanol, dimer diol, etc. Two or more of these may be used in combination.

[0014] In the polyester resin of the present invention, the content of silicone copolymerized in the polyester resin is 1 to 60% by mass, preferably 2 to 40% by mass, and more preferably 3 to 30% by mass. If the content of silicone copolymerized in the polyester is less than 1% by mass, the water repellency and water repellency durability will be poor. On the other hand, if the content of silicone copolymerized in the polyester exceeds 60% by mass, the operability will be poor, for example, when attempting to obtain fibers from the polyester resin of the present invention.

[0015] In the polyester resin of the present invention, 90% or more of the silicone is copolymerized with the polyester, preferably 98% or more, and more preferably 100%. In other words, the reaction rate of the silicone copolymerized with the polyester is 90% or more, preferably 98% or more, and more preferably 100%. By ensuring that the reactivity of silicone with polyester resin is in a high range of 90% or more, it is possible to reduce breakage of yarns during spinning, improving operability, and to reduce defects in appearance when the resulting molded product is produced, and it also results in excellent water-repellent durability.

[0016] In the present invention, the reaction rate (copolymerization rate) is calculated by the following formula. Silicone reaction rate (%) = ((mass of copolymerized silicone / (total mass of copolymerized silicone and unreacted silicone))) × 100 The method for determining the mass of copolymerized silicone and the mass of unreacted silicone will be described in detail in the Examples.

[0017] In the polyester resin of the present invention, an example of the silicone copolymerized by reacting with the polyester is shown in the following chemical formula (1), and an example of the silicone that has not copolymerized with the polyester and remains unreacted is shown in the following chemical formula (2).

[0018] [ka]

[0019] [ka]

[0020] In chemical formula (1) and chemical formula (2), R 1 is preferably an alkyl group having 1 to 10 carbon atoms or a phenyl group, and may be the same or different. Among these, a methyl group or an ethyl group is preferred from the viewpoint of small steric hindrance and good reactivity with polyester. In chemical formula (1) and chemical formula (2), R is a divalent organic group.

[0021] In chemical formula (1) and chemical formula (2), n is preferably an integer of 1 to 100, more preferably an integer of 2 to 50, and even more preferably an integer of 3 to 30. When n is an integer of 101 or greater, the reactivity with the ester may decrease. On the other hand, when n is 0, it may be difficult to impart silicone-derived properties to the polyester, and the water repellency and water repellency durability may be poor.

[0022] In chemical formula (2), X represents a substituent capable of forming an ester, and may be the same or different. Examples of X include an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a methacryl group, a polyether group, a mercapto group, a carboxyl group, a phenol group, a silanol group, an acrylic group, a carboxylic anhydride group, a polyethylene oxide group, and a polypropylene oxide group. Among these, a carbinol group, a carboxyl group, and a polyether group are preferred from the viewpoint of reactivity with polyester.

[0023] Examples of silicones represented by chemical formula (2) include silicones modified with carbinol groups, silicones modified with carboxyl groups, silicones modified with polyether groups, silicones modified with epoxy groups, silicones modified with silanol groups, silicones modified with carboxylic acid anhydrides, etc. Among these, from the viewpoint of reactivity with polyester, silicones modified at both ends with carbinol groups, silicones modified at both ends with carboxyl groups, and silicones modified at both ends with polyether groups are more preferred.

[0024] The intrinsic viscosity of the polyester resin of the present invention is preferably 0.5 to 0.80, and more preferably 0.50 to 0.75. If the intrinsic viscosity is less than 0.5, when a fiber is obtained from the polyester resin of the present invention, the strength is low and the operability is reduced. On the other hand, if the intrinsic viscosity exceeds 0.80, the handleability may be poor. The intrinsic viscosity is measured at a temperature of 20°C using an equal weight mixture of phenol and tetrachloroethane as a solvent.

[0025] The polyester resin of the present invention may contain various additives, as needed, to the extent that the properties of the resin are not impaired, such as other resins, heat stabilizers, antioxidants, reinforcing materials, pigments, antidegradants, weather resistance agents, flame retardants, plasticizers, preservatives, ultraviolet absorbers, antistatic agents, antiblocking agents, etc. These additives may be used alone or in combination of two or more.

[0026] The polyester resin of the present invention may contain titanium oxide, which is generally used as a matting agent or white pigment, in order to improve the whiteness of the resulting fiber and to obtain a fabric with a good color tone. The content of titanium oxide is preferably 0.05 to 5 parts by mass relative to 100 parts by mass of the polyester resin of the present invention.

[0027] Next, the method for producing the polyester resin of the present invention will be described below. The polyester resin of the present invention is produced by carrying out an esterification reaction and a polycondensation reaction. First, a mixture of polyester raw material and silicone, and a tin-based esterification catalyst are placed in an arbitrary esterification reactor, and an esterification reaction is carried out.

[0028] Examples of polyester raw materials include aliphatic diols such as ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexamethylenediol, 1,4-cyclohexanedimethanol, and dimer diol; and aromatic dicarboxylic acid components such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, dodecanedioic acid, and dimer acids.

[0029] Ethylene terephthalate oligomers can also be used as polyester raw materials. Known or commercially available ethylene terephthalate can be used. It can also be produced by known production methods.

[0030] In particular, the ethylene terephthalate oligomer may be, for example, an esterification reaction product of ethylene glycol and terephthalic acid. The number-average degree of polymerization of the ethylene terephthalate oligomer is not particularly limited, but may be, for example, about 2 to 20.

[0031] The silicone used in the production method of the present invention includes the silicone represented by the above chemical formula (2). The molecular weight of the silicone is preferably 500 to 10,000, and more preferably 900 to 6,000. If the molecular weight is less than 500, the resulting polyester resin may have poor water repellency, while if it exceeds 10,000, the reaction between the silicone and the polyester may not proceed smoothly, leaving a large amount of unreacted silicone in the polyester, which may result in a reduced reaction rate.

[0032] In the production method of the present invention, by using a tin-based esterification catalyst as the esterification catalyst, the esterification reaction between silicone and polyester proceeds more rapidly, leaving less unreacted silicone, and making it possible to produce a polyester resin with excellent water repellency, compared to polyester resins produced by adding other esterification catalysts (for example, titanium-based esterification catalysts).

[0033] Examples of tin-based esterification catalysts include mono-n-butyltin oxide, tetrabutyltin, butylchlorotin dihydroxy, butyltris-2-ethylhexanoate, tin oxalate, dimethyltin maleate, etc. From the viewpoint of reactivity between silicone and polyester, mono-n-butyltin oxide is preferred.

[0034] In the method for producing a polyester resin of the present invention, the amount of the tin-based esterification catalyst added is 1×10 -5 ~1×10 -4 moles is 2 x 10 -5 ~6×10 -5 % by mole is preferable. If the amount of tin-based esterification catalyst added is less than this range, the reaction between the polyester raw material and the silicone does not proceed, and unreacted silicone remains in the resin, resulting in a decrease in the reaction rate. As a result, the unreacted silicone becomes a foreign substance, and when attempting to obtain fibers using the polyester resin, thread breakage is likely to occur during spinning, and when attempting to obtain molded products, appearance defects are likely to occur. Furthermore, when fibers are made, the water repellency durability is reduced. On the other hand, if the amount of tin-based esterification catalyst added is greater than this range, the silicone will decompose during the reaction, and the decomposed silicone will become a foreign substance in the resin. As a result, thread breakage will be more likely to occur during spinning, and defects in appearance will be more likely to occur when attempting to obtain a molded product. Furthermore, when the resin is made into fibers, etc., the water-repellent durability will decrease.

[0035] In the method for producing a polyester resin of the present invention, the esterification reaction temperature is 250 to 270°C, and preferably 255 to 265°C. If the reaction temperature is lower than this range, the reaction between the polyester raw material and the silicone will not proceed, and unreacted silicone will remain in the resin, resulting in a decrease in the reaction rate. As a result, the unreacted silicone will become a foreign substance, and as a result, when attempting to obtain fibers using the obtained polyester resin, thread breakage will be more likely to occur during spinning, and when attempting to obtain molded products, appearance defects will be more likely to occur. Furthermore, when made into fibers, etc., the water repellency durability will be reduced. On the other hand, if the reaction temperature is higher than this range, the silicone will decompose during the reaction and the decomposed silicone will become contained in the resin and become a foreign substance, and as a result, when an attempt is made to obtain fibers using the polyester resin, thread breakage will be more likely to occur during spinning, and when an attempt is made to obtain a molded product, appearance defects will be more likely to occur, etc. Furthermore, when the polyester resin is made into fibers, etc., the water repellency durability will be reduced.

[0036] After the esterification reaction is complete, the resulting ester is transferred to a polycondensation reactor of your choice, where a polycondensation catalyst is added to carry out the polycondensation reaction. Examples of polycondensation catalysts include antimony-based polycondensation catalysts and titanium-based polycondensation catalysts, but titanium-based polycondensation catalysts are preferred because they allow the polycondensation reaction of the silicone copolyester to proceed in a relatively short time, resulting in a high silicone reaction rate and enabling the production of a polyester resin with excellent water-repellent durability.

[0037] In the method for producing a polyester resin of the present invention, the amount of polycondensation catalyst added is 1×10 -5 ~1×10 -4 moles is 2 x 10 -5 ~6×10 -5 It is preferable that the amount of polycondensation catalyst added is less than this range, the reaction between the polyester raw material and the silicone does not proceed, and unreacted silicone remains in the resin, resulting in a decrease in the reaction rate. As a result, the unreacted silicone becomes a foreign substance, and when the resulting resin is used to make fibers, breakage of the yarn is likely to occur during spinning, or defects in appearance may occur when a molded product is made. Furthermore, when the resin is made into fibers, the water repellency durability is reduced. On the other hand, if the amount of polycondensation catalyst added is greater than this range, the silicone will be decomposed during the reaction, and the decomposed silicone will be contained in the resin and become foreign matter.As a result, when the obtained resin is used to make fibers, thread breakage will easily occur during spinning, or when a molded product is made, appearance defects etc. will occur.In addition, when made into fibers, the water repellency durability will decrease.

[0038] In the method for producing a polyester resin of the present invention, the polycondensation reaction is carried out at a temperature of 250 to 270°C, preferably 255 to 265°C. If the reaction temperature is lower than this range, the reaction between the polyester raw material and the silicone does not proceed, and unreacted silicone remains in the resin, resulting in a decrease in reaction rate. As a result, the unreacted silicone becomes a foreign substance, and when the obtained resin is used to make fibers, breakage is likely to occur during spinning, or when a molded product is made, defects in appearance and the like occur. Also, when the resin is made into fibers, the water-repellent durability is reduced. On the other hand, if the reaction temperature is higher than this range, the silicone is decomposed during the reaction, and the decomposed silicone is contained in the resin and becomes a foreign substance. As a result, when the obtained resin is used to make fibers, breakage is likely to occur during spinning, or when a molded product is made, defects in appearance and the like occur. Also, when the resin is made into fibers, the water-repellent durability is reduced.

[0039] The polycondensation reaction is preferably carried out at a pressure in the reactor of 1.0 hPa or less. If the pressure during the polycondensation reaction exceeds 1.0 hPa, the polycondensation reaction time becomes long, which may result in poor productivity.

[0040] During the polycondensation reaction, if necessary, a hindered phenol-based antioxidant may be added together with the above-mentioned polymerization catalyst, or a phosphorus compound may be added for the purpose of suppressing thermal decomposition of the resin.

[0041] Examples of hindered phenol antioxidants include 2,6-di-t-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 4,4'-butylidenebis-(3-methyl-6-t-butylphenol), ... Examples of suitable compounds include ethylene glycol-bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate] and 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1'-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, but tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane is preferred from the standpoint of effectiveness and cost. These compounds can be used alone or in combination of two or more.

[0042] Examples of phosphorus compounds that can be used include phosphorous acid, phosphoric acid, trimethyl phosphite, triphenyl phosphite, tridecyl phosphite, trimethyl phosphate, tridecyl phosphate, triphenyl phosphate, etc. These compounds can be used alone or in combination of two or more.

[0043] The uses of the polyester resin of the present invention are not particularly limited, and examples thereof include fibers, films, molded articles, resin solutions, powders, etc. For each use, the polyester resin of the present invention can be used alone or in combination with other resin compositions, etc., and can be processed by known techniques in the production method.

[0044] When fibers are obtained using the polyester resin of the present invention, not only can the entire single fiber be formed from the polyester resin of the present invention, but also conjugated fibers can be obtained from the polyester resin of the present invention and a resin composition other than the polyester resin of the present invention (for example, a polyester resin containing inorganic particles such as titanium dioxide in addition to a polyethylene terephthalate resin or a polyester resin containing other copolymerization components). Examples of conjugated fibers include a core-sheath type, a side-by-side type, and an islands-in-sea type. For example, when a core-sheath fiber is obtained using the polyester resin of the present invention, it is preferable to use the polyester resin of the present invention as the sheath portion from the viewpoint of water repellency. In this case, the mass ratio of the core to the sheath portion (core / sheath) is preferably 60 / 40 to 90 / 10. [Example]

[0045] The present invention will now be described in detail with reference to examples, in which the measurement and evaluation methods for various properties and the like are as follows. (a) Intrinsic viscosity Using the obtained polyester resin, a mixture of equal masses of phenol and tetrachloroethane was used as a solvent, and measurement was carried out at a temperature of 20°C by a known method.

[0046] (b) Silicone content and reaction rate in polyester resin The obtained polyester resin was dissolved in hexafluoroisopropanol, deuterated tetrachloroethane was added, and the mixture was heated at 130° C. to remove the hexafluoroisopropanol. Then, using a JNM-ECZ400R / S1 NMR device manufactured by JEOL, 1 H-NMR was measured. The content of copolymerized silicone was determined from the integrated intensity of the proton peaks of each component in the resulting chart (terephthalic acid peak (δ: approximately 8.0 ppm), ethylene glycol peak (δ: approximately 4.6 ppm), diethylene glycol peak (δ: approximately 3.8 ppm)) and the proton peaks in the silicone copolymerized by the reaction.

[0047] The reaction rate of silicone was calculated from the mass of copolymerized silicone and the mass of unreacted silicone using the following formula: Reaction rate of silicone (%) = (mass of copolymerized silicone / (total mass of copolymerized silicone and unreacted silicone) × 100

[0048] The mass of copolymerized silicone and the mass of unreacted silicone were determined as follows. In Examples 1 to 8 and 11 and Comparative Examples 1 to 11, the masses of the copolymerized silicone and the unreacted silicone were determined from the integrated intensity of the proton peak (δ: approximately 3.5 ppm) representing both the silicone that had reacted with the polyester and been copolymerized and the unreacted silicone, and the proton peak (δ: approximately 0.5 ppm) representing only the unreacted silicone.

[0049] In Example 9, the masses of the copolymerized silicone and the unreacted silicone were determined from the integrated intensity of the proton peak (δ: approximately 0.9 ppm) indicating the silicone that had reacted with the polyester and been copolymerized, and the proton peak (δ: approximately 0.8 ppm) indicating the unreacted silicone. In Example 10, the mass of the copolymerized silicone and the mass of the unreacted silicone were determined from the integrated intensity of the proton peak (δ: approximately 0.5 ppm) representing both the silicone that had reacted with the polyester and been copolymerized and the unreacted silicone, and the proton peak (δ: approximately 5.2 ppm) representing only the unreacted silicone.

[0050] (c) Molecular weight of silicone For the silicones used in the examples and comparative examples, the molecular weight was calculated from the hydroxyl value (mgKOH / g) and functional group equivalent (g / mol).

[0051] (d) Contact angle The obtained polyester resin was used to prepare a 0.2 mm thick sheet using an OCS gel counter under the following conditions: extruder temperature 260-290°C, rotation speed 130 rpm, winder temperature 30-50°C, rotation speed 2 m / min. The contact angle of this sheet was measured using the sessile drop method using a KRUSS DSA30 high-performance automatic contact angle meter. The larger the contact angle, the better the water repellency.

[0052] (e) Coefficient of kinetic friction, coefficient of static friction The sheet used to measure the contact angle was measured using a friction tester TR-2 manufactured by Toyo Seiki Seisaku-sho, under the following conditions: 200 g of plated chrome metal piece, test speed 100 mm / min, test distance: 180 mm, measurement environment: 23°C x 50% RH.

[0053] (f) Runnability (number of thread breakages) The obtained polyester resin was melt-spun in a spinning apparatus for 24 hours continuously, and the number of thread breaks per spindle was counted and evaluated as follows. ○: Thread breakage less than once ×: Thread breakage occurred more than twice

[0054] (g) Water repellency of the fabric The obtained cylindrical knitted fabric was evaluated according to the spray method described in JIS L 1092. Grade 4 or higher was considered to be acceptable.

[0055] (h) Water-repellent durability (washing durability) The obtained cylindrical knitted fabric was washed 10 times (HL10) according to the 103 method described in JIS L 0217, and then the water repellency was evaluated according to the spray method described in JIS L 1092. Grade 4 or higher was considered to be acceptable.

[0056] Example 1 A slurry of terephthalic acid (TPA) and ethylene glycol (EG) (TPA / EG molar ratio = 1 / 1.6) was supplied to an esterification reactor and reacted at a temperature of 250°C and a pressure of 50 hPa to obtain ethylene terephthalate oligomer (number average degree of polymerization: 5) with an esterification reaction rate of 95%. 70 parts by mass of this ethylene terephthalate oligomer was mixed with a carbinol-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6000", R 2 ;CH2CH2CH2-O-CH2CH2, molecular weight = 950) 30 parts by mass, dimethyltin oxide as a tin-based esterification catalyst was used in an amount of 5 × 10 per mole of the total acid components -5 The esterification reaction was carried out at a reaction temperature of 260°C for 2 hours.

[0057] [ka]

[0058] The resulting esterification reaction product was transferred from the esterification reactor to a polycondensation reaction vessel, and tetrabutyl titanate as a titanium-based polycondensation catalyst was added to the resulting esterification reaction product in an amount of 5 × 10 per mole of the total acid components. -5 The pressure was gradually reduced to 1.0 hPa or less after 75 minutes at a reaction temperature of 260°C. Under these conditions, a polycondensation reaction (melt polymerization reaction) was carried out for 5 hours with stirring to obtain a polyester resin with an intrinsic viscosity of 0.68.

[0059] [Manufacturing of fibers and cylindrical knitted fabrics] The resulting polyester resin was fed alone into an extruder and then into a spinning device, where it was melt-spun from a spinneret (hole diameter 0.20 mm, 36 spinning holes). After spinning, the mixture was cooled by airflow and passed through an oiling device to apply an oil to a coating amount of 0.5% by mass. The mixture was then focused using a focusing guide, entangled, and then taken up by a roller at a spinning speed of 1400 m / min and wound on a winder. The resulting fiber (semi-undrawn yarn) had a fiber density of 220 dtex / 36 f and was free of defects such as fluff or single yarn breakage. This was then drawn using a conventional drawing device at a speed of 725 m / min, a draw ratio of 2.77, and a temperature of 160°C to obtain a polyester fiber of 80 dtex / 36 f. Next, using this polyester fiber, a cylindrical knitted fabric of about 40 cm was made using a cylindrical knitting machine (NDP-01) manufactured by Eiko Sangyo Co., Ltd.

[0060] Examples 2 to 7, Comparative Examples 1 to 10 A polyester resin was obtained in the same manner as in Example 1, except that the amount of catalyst added, the esterification reaction temperature, the polycondensation reaction temperature, or the silicone content was changed. [Manufacturing of fibers and cylindrical knitted fabrics] Polyester fibers and tubular knit fabrics of 80 dtex / 36 f were obtained in the same manner as in Example 1, except that the polyester resins obtained in Examples 2 to 7 and Comparative Examples 1 to 10 were used, respectively.

[0061] Example 8 A polyester resin was obtained in the same manner as in Example 1, except that the type of silicone was changed to a carbinol-modified silicone shown in formula (3) (silicone manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", molecular weight = 1840). [Manufacturing of fibers and cylindrical knitted fabrics] A polyester fiber and a tubular knit fabric of 80 dtex / 36 f were obtained in the same manner as in Example 1, except that the obtained polyester resin was used.

[0062] Example 9 The type of silicone was a carboxyl-modified silicone shown in formula (4) (silicone manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-22-162C", R 3 A polyester resin was obtained in the same manner as in Example 1, except that the copolymer was changed to ethylenediaminetetraacetic acid (CH2CH2, molecular weight = 2280). [Manufacturing of fibers and cylindrical knitted fabrics] A polyester fiber and a tubular knit fabric of 80 dtex / 36 f were obtained in the same manner as in Example 1, except that the obtained polyester resin was used.

[0063] [ka]

[0064] Example 10 The type of silicone was polyether-modified silicone shown in formula (5) (silicone manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-22-4952", R 4A polyester resin was obtained in the same manner as in Example 1, except that the copolymer was changed to ethylenediaminetetraacetic acid; CH2CH2CH2-O, molecular weight = 2240). [Manufacturing of fibers and cylindrical knitted fabrics] A polyester fiber and a tubular knit fabric of 80 dtex / 36 f were obtained in the same manner as in Example 1, except that the obtained polyester resin was used.

[0065] [ka]

[0066] Example 11 A polyester resin was obtained in the same manner as in Example 1, except that the reaction time for the polycondensation reaction was changed to 4 hours. [Manufacturing of fibers and cylindrical knitted fabrics] A polyester fiber and a tubular knit fabric of 80 dtex / 36 f were obtained in the same manner as in Example 1, except that the obtained polyester resin was used.

[0067] Example 12 [Manufacturing of fibers and cylindrical knitted fabrics] The polyester resin obtained in Example 1 was used as the sheath, and polyethylene terephthalate resin (PET) containing 0.35% by mass of titanium dioxide with an intrinsic viscosity of 0.64 was used as the core. The materials were then fed into an extruder, and subsequently fed into a spinning apparatus. A concentric sheath-core composite fiber with a core / sheath mass ratio of 85 / 15 was melt-spun from a spinneret (hole diameter 0.35 mm, 48 spinning holes). After spinning, the fiber was cooled by airflow and passed through an oiling device to apply an oil to a coating amount of 0.5% by mass. The fiber was then focused using a focusing guide, entangled, and then taken up by a roller at a spinning speed of 3000 m / min and wound on a winder. The resulting fiber (semi-undrawn yarn) had a density of 125 dtex / 48 f and was free of defects such as fluff or single yarn breakage. This was stretched at a speed of 725 m / min, a ratio of 1.53, and a temperature of 160° C. using a conventional stretching device to obtain a core-sheath bicomponent polyester fiber of 80 dtex / 48 f. Next, using this core-sheath composite polyester fiber, a cylindrical knitted fabric of about 40 cm was made using a cylindrical knitting machine (NDP-01) manufactured by Eiko Sangyo Co., Ltd.

[0068] Example 13 [Manufacturing of fibers and cylindrical knitted fabrics] An 80 dtex / 48 f core-sheath composite polyester fiber and a tubular knit fabric were obtained in the same manner as in Example 12, except that the polyester resin obtained in Example 2 was used as the sheath portion.

[0069] Example 14 [Manufacturing of fibers and cylindrical knitted fabrics] An 80 dtex / 48 f core-sheath composite polyester fiber and a tubular knit fabric were obtained in the same manner as in Example 12, except that the polyester resin obtained in Example 3 was used as the sheath portion.

[0070] Example 15 [Manufacturing of fibers and cylindrical knitted fabrics] An 80 dtex / 48 f core-sheath composite polyester fiber and a tubular knit fabric were obtained in the same manner as in Example 12, except that the polyester resin obtained in Example 8 was used as the sheath.

[0071] Example 16 [Manufacturing of fibers and cylindrical knitted fabrics] An 80 dtex / 48 f core-sheath composite polyester fiber and a tubular knit fabric were obtained in the same manner as in Example 12, except that the polyester resin obtained in Example 9 was used as the sheath portion.

[0072] Example 17 [Manufacturing of fibers and cylindrical knitted fabrics] An 80 dtex / 48 f core-sheath composite polyester fiber and a tubular knit fabric were obtained in the same manner as in Example 12, except that the polyester resin obtained in Example 10 was used as the sheath.

[0073] Tables 1 and 2 show the production conditions, property values, and evaluation results of the polyester resins, sheets, and fibers obtained in the examples and comparative examples. [Table 1] [Table 2]

[0074] Table 3 shows details of the silicones used in the examples and comparative examples. [Table 3]

[0075] As is clear from Tables 1 and 2, the polyester resins obtained in Examples 1 to 11 had silicone copolymerized therein and had high reaction rates, which resulted in excellent spinning operability, and the resulting sheets and fibers (single-component polyester fibers and core-sheath composite polyester fibers) had excellent water repellency and water repellency durability.

[0076] On the other hand, the polyester resin obtained in Comparative Example 1 had a low content of copolymerized silicone, and therefore was inferior in water repellency and water repellency durability. The polyester resin obtained in Comparative Example 2 had an excessively high content of copolymerized silicone, which resulted in frequent thread breakage during spinning and poor spinning operability.

[0077] The polyester resin obtained in Comparative Example 3 had a low reaction rate due to the small amount of dimethyltin oxide (esterification catalyst) added, and unreacted silicone remained in the resin as foreign matter, resulting in frequent yarn breakage during spinning and poor operability. Furthermore, the water-repellent durability was also poor. The polyester resin obtained in Comparative Example 4 contained a large amount of dimethyltin oxide, an esterification catalyst, which caused decomposition of the silicone, and the decomposed silicone became a foreign substance in the resin, causing frequent yarn breakage during spinning and resulting in poor operability.The resin also had poor water repellency durability.

[0078] In Comparative Example 5, the esterification reaction temperature was as low as 240° C., so the reaction did not proceed sufficiently and a polyester resin could not be obtained, and therefore the product could not be evaluated. The polyester resin obtained in Comparative Example 6 had a high esterification reaction temperature of 280°C, which accelerated silicone decomposition, and the silicone decomposition products present in the resin became foreign matter, causing frequent yarn breakage during spinning and resulting in poor operability. Furthermore, the water-repellent durability was also poor.

[0079] The polyester resin obtained in Comparative Example 7 had a low silicone reaction rate due to the small amount of tetrabutyl titanate added as a polycondensation catalyst, and the presence of unreacted silicone in the polyester resin resulted in foreign matter, which caused frequent yarn breakage during spinning and resulted in poor operability. Furthermore, the water-repellent durability was also poor. The polyester resin obtained in Comparative Example 8 contained a large amount of tetrabutyl titanate, a polycondensation catalyst, which caused decomposition of the silicone, and the decomposed silicone became a foreign substance in the resin, causing frequent thread breakage during spinning and resulting in poor operability.The water repellency durability was also poor.

[0080] In Comparative Example 9, the polycondensation reaction temperature was as low as 240° C., so the reaction did not proceed sufficiently and a polyester resin could not be obtained, and therefore the product could not be subjected to evaluation.

[0081] In Comparative Example 10, the polycondensation reaction temperature was as high as 280°C, which accelerated the decomposition of the silicone, and the silicone decomposition products became foreign matter in the polyester resin, resulting in frequent yarn breakage during spinning and poor operability. In addition, the water repellency durability was poor.

Claims

1. A polyester resin comprising a polyester made of an aromatic dicarboxylic acid and an aliphatic diol and silicone contained therein, 90% or more of the silicone is copolymerized with polyester; the content of copolymerized silicone in the polyester resin is 1 to 60 mass %, A polyester resin having an intrinsic viscosity of 0.5 to 0.

8.

2. A fiber comprising the polyester resin according to claim 1.

3. A film comprising the polyester resin according to claim 1.

4. A molded article comprising the polyester resin according to claim 1.

5. A resin solution containing the polyester resin according to claim 1.

6. A powder containing the polyester resin according to claim 1.

7. A method for producing a polyester resin by carrying out an esterification reaction and a polycondensation reaction, A mixture of polyester raw materials and silicone, A tin-based esterification catalyst was used in an amount of 1×10 per mole of the total acid component of the polyester. －５ ~1 x 10 －４ After adding 1 mole of methyl methyl acrylate, the esterification reaction was carried out at a reaction temperature of 250 to 270°C. The polycondensation catalyst was used in an amount of 1×10 －５ ~1 x 10 －４ A method for producing a polyester resin, comprising adding 1 mole of methyl methylcellulose and carrying out a polycondensation reaction at a reaction temperature of 250 to 270°C.

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