Core-sheath composite fiber for support of water treatment separation membrane, support for water treatment separation membrane including the same, separation membrane for water treatment including the same, and filter module including the same

Abstract

The present invention relates to a core-sheath type composite fiber for a support of a separation membrane for water treatment, which does not elute heavy metals, is harmless to the human body, and has excellent hue transparency and strength; a support for a separation membrane for water treatment comprising the same; a separation membrane for water treatment comprising the same; and a filter module comprising the same.

Description

[Technical Field]

[0001] The present invention relates to a core-sheath type composite fiber for a support of a water treatment separation membrane, a support for a water treatment separation membrane including the same, a separation membrane for water treatment including the same, and a filter module including the same. [Background technology]

[0002] The nonwoven fabric used as the base material in most filters is polyethylene terephthalate fiber. Conventional polyethylene terephthalate fiber uses an antimony-based polymerization catalyst, which causes the problem of antimony, a type of heavy metal, leaching out when stagnant in water. In the future, the problem of heavy metals leaching out of nonwoven fabrics in the drinking water filter market could pose an issue of harmful substances being generated.

[0003] For these reasons, various compounds have been proposed as catalysts to replace antimony compounds and germanium compounds in the production of polyethylene terephthalate fibers. Among these, titanium (Ti) compounds have been proposed in various types due to their low cost and non-toxicity. However, polyester resins produced using titanium compounds as catalysts have drawbacks such as a characteristic yellow color and poor thermal stability. For example, decomposition reactions occur during polycondensation or melt molding, resulting in the production of large amounts of by-products such as acetaldehyde. Therefore, there is a need for a method for producing polyester resins that can solve problems such as improving the color and thermal stability of the produced polyester resins and reducing the acetaldehyde content. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned problems, and provides a core-sheath type composite fiber for a support of a water treatment separation membrane, which has excellent bonding strength with a support layer of the water treatment membrane, is significantly less harmful to humans, and has excellent color transparency and strength; a support for a water treatment separation membrane including the same; a separation membrane for water treatment including the same; and a filter module including the same. [Means for solving the problem]

[0005] The sheath-core composite fiber for a support of a water treatment separation membrane of the present invention, which solves the above-mentioned problems, is a sheath-core composite fiber including a core and a sheath, and the sheath contains a sheath polyester resin.

[0006] In a preferred embodiment of the present invention, the polyester resin for the sheath includes a polycondensate obtained by esterification and polycondensation of an acid component and a diol component, wherein the acid component includes 20 to 40 mol % of isophthalic acid (IPA) and the remaining amount of terephthalic acid (TPA), and the diol component may include a compound represented by the following Chemical Formula 1:

[0007] In a preferred embodiment of the present invention, the content of carboxyl groups (—COOH) in the polyester for the sheath is 4.5×10 7 It may be eq / g or less.

[0008] In a preferred embodiment of the present invention, the core-sheath type composite fiber has a ratio of the sheath portion to the core portion of 1:1.5 to 1:4.0. Cross-sectional area It may be included in the ratio.

[0009] Another object of the present invention is to produce a support for a water treatment separation membrane, which includes the above-mentioned core-sheath type composite fiber.

[0010] In a preferred embodiment of the present invention, the support for a water treatment separation membrane may be a nonwoven fabric.

[0011] In a preferred embodiment of the present invention, the support for a water treatment separation membrane may further contain a PET monofilament in addition to the core-sheath type composite fiber.

[0012] In a preferred embodiment of the present invention, the support for a water treatment separation membrane may be a hot-melt nonwoven fabric produced by mixing and opening core-sheath type composite fibers and PET monofilaments, followed by heat treatment.

[0013] In a preferred embodiment of the present invention, when a test piece obtained by cutting the support into a weight of 0.7 g is immersed in 1,000 g of deionized water (DI water) having a purity of 99.9% or more for 100 hours, the test piece is removed, and the concentration of heavy metal elements eluted into the deionized water is measured. The amount of eluted heavy metal is 1 ppm or less, and the heavy metal elements have an atomic weight of 63 to 200 Da (Daltons) and a density of 4.0 g / cm. 3 It may be more than that.

[0014] As another object of the present invention, a separation membrane for water treatment can be manufactured, including: the support; a support layer formed on one or both sides of the support; and an active layer formed on the surface of the support layer.

[0015] In a preferred embodiment of the present invention, the support layer may include one or more selected from the group consisting of polysulfone polymers, polyacrylonitrile polymers, and polyethersulfone polymers.

[0016] As a further object of the present invention, a filter module can be manufactured, which includes a filter including at least one of the water treatment separation membranes and wound spirally around the outer surface of a perforated pipe. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a core-sheath type composite fiber for a support of a water treatment separation membrane, which has excellent bonding strength with a support layer of the water treatment membrane, is significantly less harmful to humans, and has excellent color transparency and strength, a support for a water treatment separation membrane containing the same, a separation membrane for water treatment containing the same, and a filter module containing the same. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will now be described with reference to the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present invention.

[0019] The core-sheath type composite fiber for a support of a water treatment separation membrane according to the present invention may comprise a core and a sheath.

[0020] In this case, the sheath-core composite fiber can be produced by a process including: a first step of conjugating a core resin and a sheath resin to obtain a spun product; and a second step of drawing the spun product to produce a sheath-core composite fiber.

[0021] The first-stage composite spinning can be carried out at a spinning speed of 3,000 to 5,400 mpm, preferably 4,000 to 5,200 mpm. If the spinning speed is less than 3,000 mpm, the desired draw ratio cannot be achieved in the subsequent drawing step, resulting in a problem of a decrease in the draw ratio. If the spinning speed is more than 5,400 mpm, the problem of fiber breakage during spinning may occur.

[0022] Next, the second-stage drawing can be performed at a ratio of 2.0 to 5.0, preferably 2.0 to 4.0. If the drawing is performed at a ratio of less than 2.0, poor orientation of the core and / or sheath of the core-sheath composite fiber can result in poor yarn uniformity and a decrease in core strength. If the drawing is performed at a ratio of more than 5.0, not only can spinning operability be poor, but the fusion rate can also be reduced due to overdrawing of the sheath.

[0023] The core-sheath type composite fiber thus produced has a sheath to core ratio of 1:1.5 to 1:4.0. Cross-sectional area The ratio is preferably 1:1.8 to 3.0. Cross-sectional area ratio In this case, it is better to include Cross-sectional area If the ratio is less than 1.5, there may be a problem that the mechanical properties such as the strength of the composite fiber are reduced, and the core Cross-sectional area The ratio is 4.0 Cross-sectional area If the ratio exceeds this, the mechanical properties of the composite fiber will be excellent, but the thermal adhesive strength of the composite fiber may be low.

[0024] [Resin for sheath] The melting point of the resin for the sheath may be 150 to 200° C., preferably 160 to 190° C. In this case, if the melting point of the resin for the sheath is less than 150° C., there may be a problem that the thermal adhesive properties are not exhibited, and if the melting point of the resin for the sheath is more than 200° C., there may be a problem that the article becomes hard and the soft feel is significantly reduced, so it is better to configure the melting point of the resin for the sheath to satisfy the above range.

[0025] The shell resin satisfying the above melting point range can be produced by carrying out a first step of esterifying an acid component and a diol component to produce an ester compound, and a second step of polycondensing a mixture containing the ester compound and the titanium chelate catalyst represented by Chemical Formula 2 to produce a polycondensation reaction product.

[0026] Furthermore, a resin for the shell can be produced by further carrying out a third step of mixing the polycondensation reaction product with a toner.

[0027] [ka]

[0028] In the above chemical formula 2, R1 to R4 may each independently represent a linear alkylene group having 1 to 3 carbon atoms, preferably a linear alkylene group having 1 to 2 carbon atoms, and more preferably a linear alkylene group having 1 carbon atom.

[0029] In this case, the polycondensation reaction is carried out by adding the catalyst to the reactant. The reaction can be carried out by adding the catalyst to a content of 10 to 20 ppm, preferably 5 ppm to 30 ppm. If the titanium atom content is less than 5 ppm, the reaction rate may be slowed and productivity may decrease. Conversely, if the titanium atom content exceeds 30 ppm, the reactivity may be sufficient, but the catalyst may act as a foreign substance, which may decrease the physical properties, such as mechanical strength and thermal adhesion, of the fibers produced by spinning the produced polyester resin.

[0030] The esterification reaction can be carried out by adding the acid component and the diol component in a molar ratio of 1:1 to 1:2.0, preferably 1:1.1 to 1:1.5. If the molar ratio of the diol component is less than 1:1, the acidity becomes excessively high during polymerization, promoting side reactions, and if the molar ratio of the diol component is less than 1:2.0, the degree of polymerization is insufficient.

[0031] The acid component and diol component in the first step of producing the resin for the sheath will be described below.

[0032] First, the acid component may include isophthalic acid and terephthalic acid.

[0033] In this case, the isophthalic acid may be contained in an amount of 20 to 40 mol %, preferably 25 to 35 mol %, of the acid component. If the isophthalic acid content is less than 20 mol %, the resulting core-sheath composite fiber may have a high bonding temperature or poor thermal bonding properties, while if it exceeds 40 mol %, the resulting composite fiber may have excellent thermal bonding properties but may have poor spinnability during production, resulting in a high reject rate.

[0034] The terephthalic acid may be contained in the amount remaining after excluding the isophthalic acid from the acid components.

[0035] In addition to the isophthalic acid and terephthalic acid, the acid component may also contain C 6~14 Aromatic polycarboxylic acids, C 2~14 The acid component may further contain one or more selected from the group consisting of aliphatic polycarboxylic acids and sulfonate metal salts, and preferably, the acid component may be C other than terephthalic acid. 7~13 Aromatic polycarboxylic acids and C 4~12 The polycarboxylic acid may further contain one or more selected from the aliphatic polycarboxylic acids.

[0036] In this case, C other than isophthalic acid and terephthalic acid 6~14 The aromatic polycarboxylic acid can be selected without limitation from among polycarboxylic acid compounds known to be used in the production of polyester resins, but preferably, any one or more selected from the group consisting of dimethyl terephthalate and dimethyl isophthalate can be used.

[0037] Also, the above C 2~14The aliphatic polycarboxylic acid may be selected without limitation from among polycarboxylic acids known to be used in the production of polyesters, and non-limiting examples thereof include at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, citric acid, pimelic acid, azelaic acid, sebacic acid, pelargonic acid (nonanoic acid), decanoic acid, lauric acid (or dodecanoic acid), and palmitic acid (or hexadecanoic acid).

[0038] The diol component may include a compound represented by the following chemical formula 1.

[0039] [Chemical formula 1] H-O-R-OH

[0040] In the above chemical formula 1, R may be a linear alkylene group having 1 to 4 carbon atoms, a branched alkylene group having 2 to 5 carbon atoms, or -R1OR2-, and the R may preferably be a linear alkylene group having 1 to 3 carbon atoms, a branched alkylene group having 3 to 4 carbon atoms, or -R1OR2-, and the R1 and R2 may each independently be a linear alkylene group having 1 to 3 carbon atoms, or preferably a linear alkylene group having 1 to 2 carbon atoms.

[0041] More preferably, the chemical formula 1 may contain two or more compounds selected from the compounds represented by the following chemical formulas 1-1 to 1-4.

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] Preferably, the compound represented by Chemical Formula 1-1 may be contained in an amount of 13 to 40 mol%, preferably 20 to 40 mol%, and more preferably 30 to 40 mol% based on the total diol components. If the content of the compound represented by Chemical Formula 1-1 is less than 13 mol%, the polyester resin will have excellent spinnability when spun to produce fibers, but the bonding temperature may be high, the thermal bonding properties may be reduced, and the use temperature may be limited. Also, if the content of the compound represented by Chemical Formula 1-1 exceeds 40 mol%, the spinnability may be poor, problems with compatibilization may occur, and crystallinity may increase. , the thermal adhesive properties may be deteriorated.

[0047] In addition, when the compound represented by Chemical Formula 1-1 is used in an amount of 20 mol % or more, the compound represented by Chemical Formula 1-1 may be used and reacted with the compound represented by Chemical Formula 1-2 or 1-3 below to prepare a polyester resin, which is then spun to produce a polyester fiber, thereby further improving the thermal adhesion properties at low temperatures.

[0048] When the compound represented by the formula 1-2 is used as the diol component, it is preferable to use it in an amount of 0.1 to 5 mol % based on the total diol components. When the compound represented by the formula 1-3 is used as the diol component, it is preferable to use it in an amount of 0.1 to 20 mol % based on the total diol components.

[0049] Furthermore, when the compound represented by Chemical Formula 1-4 is used as a diol in combination with other diol compounds, the content of the compound represented by Chemical Formula 1-4 in the diol may be the remaining amount excluding compounds containing one or more compounds selected from Chemical Formulas 1-1 to 1-3.

[0050] In addition, the diol component may further include other diol components other than the compound represented by Chemical Formula 1, and non-limiting examples thereof include C 2~14 Specifically, the diol component may be any one or more selected from the group consisting of 1,3-propandiol, 1,4-butanediol, 1,6-hexandiol, tetramethyl glycol, pentamethyl glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, undecamethylene glycol, dodecamethylene glycol, and tridecamethylene glycol.

[0051] In the production of the sheath resin, the first-stage esterification reaction can be carried out at 200 to 300°C, preferably 230 to 270°C. If the esterification reaction is carried out at a temperature below 200°C, the reaction heat is insufficient, and the polycondensation reaction does not occur, or a low-molecular-weight polycondensate is formed, resulting in low strength and difficulty in fiberization. If the esterification reaction is carried out at a temperature above 300°C, the high reaction heat causes decomposition of the polycondensate, making it difficult to obtain a polycondensate with the desired high molecular weight. Alternatively, the high reaction heat other than the decomposition reaction produces by-products such as diethylene glycol and various dimers, which act as impurities, reducing the strength of the composite fiber and causing yellowing.

[0052] In preparing the resin for the shell, the mixture in the second step may further contain a phosphorus compound as a thermal stabilizer. In this case, the phosphorus compound is preferably a phosphoric acid or a derivative thereof, such as phosphoric acid, monomethyl phosphoric acid, trimethyl phosphoric acid, or triethyl phosphoric acid, among which trimethyl phosphoric acid or triethyl phosphoric acid is particularly preferred due to its excellent effects.

[0053] The content of the phosphorus compound is 10 to 30 parts by weight of phosphorus atoms relative to the total resin produced. If the phosphorus compound is contained in an amount of less than 10 ppm, there may be a problem of weakening of physical properties due to excessive side reactions, whereas if the phosphorus compound is contained in an amount of more than 30 ppm, there may be a problem of slowing down of the reaction rate.

[0054] The polyester resin may further contain a deodorizer. The deodorizer may be a photocatalytic oxide doped with a transition metal. While there are no particular limitations on the transition metal, considering reactivity, it is preferable to use two or more selected from the group consisting of zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), nickel (Ni), cobalt (Cr), vanadium (V), zirconium (Zr), molybdenum (Mo), silver (Ag), tungsten (W), bismuth (Bi), platinum (Pt), and gold (Au). Specific examples of the photocatalytic oxide include TiO2, SrTiO3, ZrO, SnO2, WO3, Bi2O3, and Fe2O3. TiO2 is particularly preferred, and TiO2 with an anatase structure is more preferred.

[0055] In the preparation of the sheath resin, the third step is a process for applying a toner, and the toner may be contained in an amount of 0.1 to 20 ppm, preferably 0.1 to 15.0 ppm, and more preferably 1.0 to 10.0 ppm, based on the total weight of the sheath resin (or the sheath of the composite fiber). In this case, if the amount of toner used is less than 0.1 ppm, the amount is too small, and the effect of adjusting the color tone of the composite fiber by using the toner is insufficient, while if it is used in an amount exceeding 20 ppm, it is an excessive amount, and the color tone of the composite fiber is rather deteriorated. * Since it is difficult to adjust the value, it is better to use it within the above range.

[0056] The toner preferably contains a non-cobalt dye that is less harmful to humans, and preferably contains one or more non-cobalt blue dyes and non-cobalt red dyes. From the viewpoint of fine control of color tone, a mixture of the non-cobalt blue dye and the non-cobalt red dye is more preferable. When a mixture of toners is used in the production of the core resin, a mixture of the non-cobalt blue dye and the non-cobalt red dye in a weight ratio of 1:0.3 to 0.8, preferably 1:0.3 to 0.6, is suitable for achieving the appropriate hue (tone) of the composite fiber to be produced.

[0057] The polyester resin for the sheath produced by the above method has a carboxyl group (-COOH) content of 4.5 × 10 7 eq / g or less, preferably (1.0 to 4.0) × 10 7 The carboxyl group content may be measured in eq / g. For example, the carboxyl group content can be measured by alcoholic NaOH titration, in which the polyester resin is dissolved in a benzyl alcohol solvent in an oil bath at 240°C, and then titrated with 1 / 100N alcoholic NaOH. In this case, if the carboxyl group content is 4.5×10 7 If it exceeds eq / g, the yield of the polyester resin for the sheath will be low, and the molecular weight of the polyester resin for the sheath will be low or the intrinsic viscosity will be too low, which may result in problems such as low strength of the fiber produced using the polyester resin.

[0058] The polyester resin for the sheath is L * a * b * Color space color b * The value may be 2.5 to 8, and preferably 2.5 to 5.

[0059] In addition, the polyester resin for the sheath may preferably be amorphous. When the polyester resin is contained as the sheath in a core-sheath type composite fiber, it can exhibit excellent fiber bonding function and can also realize good tactile properties at the bonded area after bonding.

[0060] The sheath-core composite fiber manufactured by the above-mentioned method has a sheath-to-core ratio of 1:1.5 to 4.0. The cross-sectional area ratio of the core to the composite fiber may be 1:1.5, preferably 1:1.8 to 3.0. If the cross-sectional area ratio of the core is less than 1.5, the strength of the composite fiber may decrease as well as the strength of the support, whereas if it exceeds 4.0, the adhesive strength of the support may decrease.

[0061] [Core resin] Next, the core resin used to produce the core of the core-sheath type composite fiber may have a melting point of 230 to 260°C, and preferably 235 to 245°C.

[0062] The core resin can be produced by a process including: a first step of producing an ester compound by esterifying an acid component and a diol component; and a second step of producing a polycondensation reaction product by polycondensing a mixture containing the ester compound and the titanium chelate catalyst represented by Chemical Formula 2.

[0063] Furthermore, a third step of mixing the polycondensation reaction product with a toner may be further carried out.

[0064] In the production of the core resin, the acid component of the first stage may include terephthalic acid.

[0065] The diol component of the first step may include one or more selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, and isopropanol, and preferably, may include one or more selected from ethylene glycol and 1,3-propanediol.

[0066] The esterification reaction can be carried out by using the acid component and the diol component in a molar ratio of 1:1.0 to 2.0, preferably 1:1.1 to 1.5. If the molar ratio of the diol component is less than 1, it may be difficult to form a polycondensate using the desired ester compound into fiber, and if the molar ratio of the diol component is more than 2, excessive by-products may be generated, so it is better to use it within this range.

[0067] In the production of the core resin, the first stage esterification reaction can be carried out at 200 to 300°C, preferably 230 to 270°C, under a pressure of 1,000 to 1,300 torr, preferably 1,050 to 1,200 torr.

[0068] In the production of the core resin, the mixture in the second step may contain the ester compound in the first step and the titanium chelate catalyst represented by Chemical Formula 2.

[0069] The second-stage polycondensation reaction can be carried out by adding the titanium chelate catalyst to the reactants so that the titanium atom content is 5 to 30 ppm, preferably 10 to 20 ppm. If the titanium atom content is less than 5 ppm, the reaction rate may be slowed and productivity may decrease. Conversely, if the titanium atom content exceeds 30 ppm, the reactivity may be sufficient, but the catalyst may act as a foreign substance, which may reduce the physical properties, such as mechanical strength and thermal adhesion, of the fibers produced by spinning the produced polyester resin.

[0070] In the preparation of the resin for the core, the mixture in the second step may further contain a deodorizer. As the deodorizer, a photocatalytic oxide doped with a transition metal may be used. The transition metal is not particularly limited, but considering reactivity, zinc (Zn), manganese (Mn), iron (Fe), copper (Cu), nickel (Ni), cobalt (Cr), vanadium (V), zirconium (Zr), molybdenum (Mo), silver (Ag), tungsten (W), bismuth ( It is preferable to use two or more selected from the group consisting of Bi, platinum (Pt), and gold (Au). Specific examples of the photocatalytic oxide include TiO2, SrTiO3, ZrO, SnO2, WO3, Bi2O3, and Fe2O3, but TiO2 is particularly preferable, and it is more preferable to use TiO2 having an anatase structure.

[0071] In addition, the mixture of the second step may further contain titanium dioxide as a quencher that can improve the surface gloss of the fiber. In the case of semi-dull (SD), it can be used in an amount of about 0.2 wt % or more, preferably 0.3 to 1.4 wt %, based on the total weight of the mixture, and in the case of full-dull (FD), it can be used in an amount of 1.5 wt % or more based on the total weight of the mixture.

[0072] The mixture of the second step may further include a thermal stabilizer, and the thermal stabilizer may include a phosphorus compound. The phosphorus compound is preferably a phosphoric acid or a derivative thereof, such as phosphoric acid, monomethyl phosphoric acid, trimethyl phosphoric acid, or triethyl phosphoric acid. Among these, trimethyl phosphoric acid or triethyl phosphoric acid is particularly preferred due to its excellent effects. The phosphorus compound is preferably included in an amount such that the weight of phosphorus atoms is 10 to 30 ppm relative to the total resin produced. If the phosphorus compound contains less than 10 ppm of phosphorus (P), excessive side reactions may result in weakened physical properties. Conversely, if the phosphorus compound contains more than 30 ppm of phosphorus, the reaction rate may be slow.

[0073] The second stage polycondensation reaction can be carried out at a temperature of 230 to 320°C, preferably 270 to 300°C.

[0074] The polycondensation reaction can be carried out under a pressure of 0.1 to 5.0 torr, and is preferably carried out under a pressure of 0.3 to 1.0 torr, but is not limited thereto.

[0075] The third step is a process for applying a toner, and the toner may be contained in an amount of 0.1 to 12 ppm, preferably 1.0 to 10.0 ppm, and more preferably 1.0 to 5.0 ppm, based on the total weight of the core resin (or the core of the composite fiber). In this case, if the amount of toner used is less than 0.1 ppm, the amount is too small, and the effect of adjusting the color tone of the composite fiber by using the toner is insufficient. If the amount of toner used is more than 10 ppm, it is an excessive amount, and the color tone b value (b * ) is difficult to adjust, so it is better to use it within the above range.

[0076] Furthermore, the toner preferably contains a non-cobalt dye that is less harmful to humans, and may preferably contain one or more non-cobalt blue dyes and non-cobalt red dyes. More preferably, a mixture of the non-cobalt blue dye and the non-cobalt red dye can be used to finely control the color tone. When a toner is mixed and used in the production of the core resin, the non-cobalt blue dye and the non-cobalt red dye are mixed in a weight ratio of 1:0.4 to 1.2, preferably 1:0.4 to 1.0, to achieve the appropriate color (tone) of the composite fiber and / or tricot filtration fabric to be produced.

[0077] Another object of the present invention is to produce a support for a water treatment separation membrane, which contains the above-mentioned core-sheath type composite fiber.

[0078] In this case, the support has an atomic mass of 63 to 200 Da (Dalton) and a density of 4.0 g / cm 3 When the above heavy metal elements are measured by the following measurement method, they may be contained at 1 ppm or less, preferably 0.7 ppm or less.

[0079] [Measurement method] The support is cut into a test piece weighing 0.7 g and placed in 1,000 g of DI water with a purity of 99.9% or higher for 100 hours, after which it is removed and the concentration of the metal elements dissolved in the DI water is measured.

[0080] The support may also have an average pore size of 0.5 μm or less, preferably 0.1 μm or less.

[0081] The support may have an average thickness of 50 to 200 mm, preferably 90 to 150 mm.

[0082] In addition, when the support for a water treatment separation membrane manufactured using the core-sheath type composite fiber described above is manufactured by applying an organic toner to the sheath and core-sheath polyester resin used in manufacturing the composite fiber, the color tone is measured according to the modified ASTM-D-1925 method and is found to be L * The (L value) value can satisfy the range of 82.0 to 95.0, preferably 84.0 to 94.0, and more preferably 85.0 to 92.0. * The (b value) value can satisfy the range of 1.0 to 6.5, preferably 1.5 to 5.0, and more preferably 1.8 to 4.4.

[0083] The support has an adhesive strength of 118 to 135 N / mm 2 , preferably 120 to 130 N / mm 2 may have

[0084] The support for the water treatment separation membrane may be a nonwoven fabric. A preferred example of producing the nonwoven fabric is to mix and open the above-described core-sheath type composite fiber and PET (polyethylene phthalate) single fiber, and then mix and open the fiber in a ratio of 1:0.5 to 1.5. Cross-sectional area After mixing and opening the fibers in the ratio, they are subjected to multi-stage heat treatment at temperatures of 120℃, 140℃ and 160℃, and the basis weight is 20-50g / m 2 The PET single fibers may have a fiber length of 30 to 80 mm and a fineness of 2.0 to 6.0 denier.

[0085] In addition, the method for producing a water treatment separation membrane of the present invention may include the steps of forming a support layer by performing a primary coating and a secondary coating on one or both sides of the support, and forming an active layer on the surface of the support layer.

[0086] In this case, the support is the same as above, and therefore its description is omitted.

[0087] First, the primary coating can be performed by coating at least one selected from polysulfone polymer, polyacrylonitrile polymer, and polyethersulfone polymer.

[0088] The secondary coating can be performed by coating a functional polymer that can impart functionality to the porous substrate, and can be any commonly known polymer without limitation.

[0089] The active layer may then preferably be a polyamide active layer, generally known Any polyamide active layer that meets the above requirements can be used in the present invention without any restrictions. A detailed description of the active layer will be omitted.

[0090] The water treatment separation membrane prepared by the above method may include the support; a support layer formed on one or both sides of the porous support; and an active layer formed on the surface of the support layer.

[0091] The separation membrane for water treatment may be a reverse osmosis separation membrane or a nanofiltration membrane.

[0092] As a further object of the present invention, a filter module can be manufactured which includes a filter including the above-mentioned water treatment separation membrane and spirally wound around the outer surface of a perforated pipe.

[0093] In this case, the filter module may include at least one of the water treatment separation membranes, and preferably may be formed by stacking a plurality of layers and winding them up.

[0094] The filter module may also be a cylindrical filter module.

[0095] The present invention will be described in more detail below with reference to examples. However, it should be understood that the following examples do not limit the scope of the present invention, but are merely intended to aid in the understanding of the present invention.

[0096] [Example] Preparation Example 1: Production of core-sheath composite fibers for use as supports for water treatment separation membranes (1) Manufacture of polyester resin for sheath An acid component containing 70 mol% terephthalic acid (TPA) and 30 mol% isophthalic acid (IPA), and a diol component containing 12 mol% of a compound represented by the following formula 1-3 and 88 mol% of a compound represented by the following formula 1-4 were added to an esterification reactor in a molar ratio of 1:1.2, and the reaction was carried out at 250°C and 1,140 Torr to produce an ester reaction product. The formed ester reaction product was transferred to a polycondensation reactor, where 15 ppm (based on the Ti content) of a compound represented by the following formula 2 was added as a polycondensation catalyst and 25 ppm (based on the P content) of triethyl phosphate as a thermal stabilizer. The pressure was gradually reduced to a final pressure of 0.5 Torr, and the temperature was raised to 280°C to carry out a polycondensation reaction, producing a polycondensation reaction product.

[0097] Next, the polycondensation reaction product was mixed with an organic toner containing a non-cobalt blue dye and a non-cobalt red dye in a weight ratio of 1:0.4 to prepare a polyester resin for the sheath, in which the content of the organic toner in the polyester resin for the sheath was 3.0 to 6.0 ppm.

[0098] The produced polyester resin for the sheath has a melting point of 175°C.

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] In the above chemical formula 2-1, R1 to R4 are each independently an alkylene group having one carbon atom.

[0103] (2) Manufacturing of polyester resin for core The core polyester resin was prepared using the same composition and method as the sheath polyester resin, but by mixing terephthalic acid as the acid component and ethylene glycol as the diol component in a molar ratio of 1:1.2 during the preparation of the ester reactant. The melting point of the core polyester resin was 245°C.

[0104] (3) Manufacturing of core-sheath composite fibers The core polyester resin was used as the core and the sheath polyester resin was used as the sheath, and the fibers were spun at 5,000 mpm, and then drawn at a draw ratio of 2.2 to produce a sheath-core composite fiber. The sheath-core composite fiber produced had a sheath to core ratio of 1:2.33. Cross-sectional area Includes ratio.

[0105] Preparative Examples 2 to 7 and Comparative Preparative Examples 1 to 4: Production of core-sheath composite fibers for use as supports for water treatment separation membranes Preparatory Examples 2 to 7 and Comparative Preparatory Examples 1 to 4 were produced using the same method as Preparatory Example 1, but under the conditions shown in Tables 1 and 2 below.

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] Experimental Example 1: Analysis of terminal groups The terminal carboxyl group (—COOH) content of the polyester resins for the sheath produced in Preparative Examples 1 to 9 and Comparative Preparative Examples 1 to 6 was measured by 1 / 100N alcoholic NaOH titration method.

[0111] 0.15 g of polyester resin powder, crushed to a 20-mesh size, was precisely measured and placed in a test tube. 5 mL of benzyl alcohol was added and dissolved at 240°C for 150 seconds while stirring with a micromixer. Immediately after dissolution, the test tube was immersed in 25°C water for 7 seconds to rapidly cool. The contents were then poured into a 50 mL beaker containing 10 mL of chloroform. An additional 5 mL of benzyl alcohol was added to the test tube and stirred for 60 seconds to completely wash out any remaining polyester resin solution. This was then immediately added to the beaker and used as the titrant. The carboxyl group content was determined by neutralization titration using phenol red (0.1% benzyl alcohol solution) as an indicator with 0.1 N sodium hydroxide benzyl alcohol solution using a microsyringe (100 μL volume). The titration value was corrected for the background test results for the titrant.

[0112] [Table 1]

[0113] [Table 2]

[0114] Example 1: Production of a support for a water treatment separation membrane The core-sheath type composite fiber of Preparation Example 1 and polyethylene terephthalate (PET) single fiber (fiber length 51 mm, fineness 4.0 de) were mixed in a ratio of 1:1. Cross-sectional area After mixing and opening the fibers at the ratio of 120℃, 14 Multi-stage heat treatment at temperatures of 0°C and 160°C results in a basis weight of 35 g / m 2 The water treatment membrane support thus produced had an average pore size of 0.05 μm and an average thickness of 125 μm.

[0115] Examples 2 to 7 and Comparative Examples 1 to 4: Production of support for water treatment separation membrane Although the support was produced in the same manner as in Example 1, Examples 2 to 7 and Comparative Examples 1 to 4 were carried out under the conditions shown in Table 3 below.

[0116] Experimental Example 2: Evaluation of the physical properties and performance of the support The physical properties and performance of the supports for water treatment separation membranes produced in Examples 1 to 7 and Comparative Examples 1 to 4 were evaluated by the following methods and are shown in Table 3 below.

[0117] (1) Measurement of heavy metal elution amount Specifically, test pieces of the support were prepared in 99.9% pure deionized water (DI water), and each test piece weighed 0.7 g. Next, each of the test pieces was immersed in the deionized water and left at room temperature. Next, after 24 hours, 48 ​​hours, 70 hours, and 90 hours, the amount of heavy metal elution from the deionized water was measured using ICP-MS (Perkin Elmer, NexION 300X), where the heavy metal refers to antimony.

[0118] (2) Measurement of color difference meter values The support for the water treatment separation membrane was cut into a size of 5 cm x 5 cm to prepare a test piece, and the test piece was placed in a cell of a spectrophotometer of Konica Minolta. * and b * The values ​​were measured.

[0119] (3) Measurement of adhesive strength A test piece of the support for the water treatment separation membrane was prepared in a size of 100 mm (L) x 20 mm (W) x 10 mm (D), and the adhesive strength was measured using a universal testing machine (UTM) according to the KSMISO36 method.

[0120] [Table 3]

[0121] The measurement results of the support physical properties in Table 3 confirm that the supports of Examples 1 to 7 had no heavy metal elution, appropriate color difference values, and high adhesive strength. The support including the core-sheath type composite fiber manufactured using a resin in which IPA was used at 18 mol %, less than 20 mol %, during the production of the sheath polyester resin, had a problem of a sharp decrease in adhesive strength of the support compared to Example 2 (IPA 25 mol % used).

[0122] The support containing the core-sheath composite fiber produced using a resin in which IPA was used at 50 mol%, more than 40 mol%, during the production of the sheath polyester resin, showed excellent results in adhesive strength compared to Example 3 (IPA 35 mol% was used). However, there was a problem in that the spinnability during the production of the core-sheath composite fiber was poor, resulting in a very high reject rate.

[0123] In the case of Comparative Example 3, which was a support made of composite fibers with a cross-sectional area ratio of sheath to core of less than 1:1.5, the adhesive strength was relatively superior compared to Examples 1 and 6, but the strength of the composite fibers was low, and as a result, the strength of the support was also poor.

[0124] Furthermore, in the case of Comparative Example 4, which is a support body made of composite fibers with a sheath-to-core cross-sectional area ratio exceeding 1:4.0, it was confirmed that there was a problem in that the adhesive strength was relatively very low compared to Examples 1 and 7.

[0125] Manufacturing Example 1: Manufacturing of water treatment separation membranes A primary coating and a secondary coating were performed on the support prepared in Example 1 to form a support layer.

[0126] In this case, the first coating was performed by coating a polysulfone polymer, and the second coating was performed by coating a functional raw material. Next, a polyamide active layer was formed on the surface of the support layer to prepare a separation membrane for water treatment.

[0127] Although one embodiment of the present invention has been described above, the concept of the present invention is not limited to the embodiment presented in this specification, and a person skilled in the art who understands the concept of the present invention can easily propose other embodiments by adding, changing, deleting, or adding components within the same concept, which can also be said to fall within the concept of the present invention.

Claims

1. A core-sheath type composite fiber comprising a sheath portion and a core portion in a cross-sectional area ratio of 1:1.5 to 1:4.0, the sheath portion contains a polyester resin for the sheath portion, the polyester resin for the sheath portion contains a polycondensate obtained by esterification and polycondensation of an acid component and a diol component, The acid component contains 20 to 40 mol% of isophthalic acid (IPA) and the remaining amount of terephthalic acid (TPA), the diol component comprises 13 to 40 mol % of a compound represented by Chemical Formula 1-1 and the remaining balance of a compound represented by Chemical Formula 1-4, or 0.1 to 5 mol % of a compound represented by Chemical Formula 1-2 and the remaining balance of a compound represented by Chemical Formula 1-4; The polyester resin for the sheath has a carboxyl group (—COOH) content of (1.0 to 4.0)×10 ７ a core-sheath type composite fiber for a support of a separation membrane for water treatment, characterized in that the fiber has a molecular weight of 1000 sq. eq / g; [Chemical formula 1-1] [Chemical formula 1-2] [Chemical formula 1-4]

2. A support for a water treatment separation membrane, comprising the core-sheath type composite fiber according to claim 1.

3. The support is The support is cut into a test piece weighing 0.7 g and immersed in 1,000 g of deionized water (DI water) having a purity of 99.9% or more for 100 hours. The test piece is then removed and the concentration of heavy metal elements eluted into the deionized water is measured. The amount of eluted heavy metals is 1 ppm or less. The heavy metal element has an atomic weight of 63 to 200 Da (Dalton) and a density of 4.0 g / cm ３ The support for a water treatment separation membrane according to claim 2, characterized in that:

4. A support according to claim 2; a support layer formed on one or both sides of the support; and an active layer formed on the surface of the support layer.

5. 5. The water treatment separation membrane according to claim 4, wherein the support layer comprises at least one selected from the group consisting of polysulfone polymers, polyacrylonitrile polymers, and polyethersulfone polymers.

6. A filter module comprising: a filter in which at least one water treatment separation membrane according to claim 4 is spirally wound on the outer surface of a perforated tube.

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