Conductive polyamide composite fibers and fiber structures using the same
The conductive polyamide composite fiber addresses strength and dyeability issues by using a terminal-modified polyamide resin with a sulfonate-containing triazine derivative, ensuring high conductivity and ease of dyeing, suitable for various fabric applications.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KB SEIREN LTD
- Filing Date
- 2022-03-31
- Publication Date
- 2026-06-23
AI Technical Summary
Conductive fibers made using modified polyesters with sulfo groups as copolymer components have lower strength and are weakened by alkali in cationic dyeing solutions, leading to reduced conductive performance and complexity in manufacturing, while conductive acrylic fibers are difficult to manufacture and unsuitable for high conductivity applications.
A conductive polyamide composite fiber is developed with a non-conductive layer made of a terminal-modified polyamide resin, where some terminal amino groups are substituted with a sulfonate-containing triazine derivative, and a conductive layer containing a conductive substance, allowing for good dyeability with both cationic and acidic dyes.
The conductive polyamide composite fiber maintains strength, exhibits good conductive performance, and can be dyed easily, making it suitable for applications requiring high conductivity and design appeal.
Smart Images
Figure 0007879136000001 
Figure 0007879136000002 
Figure 0007879136000003
Abstract
Description
Technical Field
[0001] The present invention relates to a conductive polyamide composite fiber that can be dyed with cationic dyes and acid dyes, has conductive performance, and suppresses the charging of static electricity.
Background Art
[0002] Conductive fibers are mainly used for work clothes and protective clothes for handlers of flammable dangerous goods, dust-proof clothes for clean rooms, fabrics for carpets, curtains, etc., for the purpose of preventing sparks and dust adhesion caused by static electricity. Usually, when the conductive fiber is a filament, it is used for a fabric in a form where the conductive fibers are inserted in a grid or stripe pattern at a pitch of several millimeters to several centimeters. When the conductive fiber is a staple, a fiber blended with other short fibers is used for the fabric. Examples of conductive fibers used for such fabrics include metal fibers made of metal itself, metal-plated fibers obtained by plating a metal on a general fiber, conductive coated fibers obtained by melting or solution coating a conductive substance composite resin on a general fiber, conductive composite fibers obtained by composite spinning a kneaded resin composition of a conductive substance and a thermoplastic resin, and the like. Among them, in view of conductive performance that does not cause sparks, texture when made into a fabric, corrosion resistance, chemical resistance, stretch resistance, abrasion resistance, washing durability, manufacturing cost, etc., as the conductive substance, conductive carbon black, titanium oxide particles having a conductive film, conductive inorganic particles, etc. are used, and as the thermoplastic resin, conductive composite fibers using a polyester resin or a polyamide resin are most preferably used. Among them, when a conductive fiber is mixed and used in a fabric of a fiber that can be dyed with a cationic dye, such as aramid fiber often used for work clothes and protective clothes, acrylic fiber used for sweaters and fleeces, etc., the conductive fiber contained in the fabric is not dyed during cationic dyeing, and the conductive fiber becomes conspicuous on the fabric, resulting in a loss of design. This has been a problem. To solve the above problems, for example, Patent Document 1 proposes a conductive polyester fiber that can be dyed with cationic dyes by using conductive composite fibers consisting of a conductive layer and a non-conductive layer, wherein the conductive layer uses conductive carbon black or titanium oxide having a conductive coating, and the non-conductive layer uses a modified polyester containing a dicarboxylic acid component including phosphonium sulfonate as a copolymer component. Furthermore, Patent Documents 2 and 3 propose conductive composite fibers in which an acrylic copolymer resin is used as the non-conductive layer, as well as fabrics containing conductive acrylic fibers and aramid fibers. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] International Publication No. WO2020 / 261914 [Patent Document 2] Japanese Patent Publication No. 2009-221632 [Patent Document 3] International Publication No. WO2018 / 084040 [Overview of the Initiative] [Problems that the invention aims to solve]
[0004] However, conductive fibers made using modified polyesters containing a dicarboxylic acid component with a sulfo group and some kind of salt as copolymer components tend to have lower strength compared to conductive fibers made using polyester polymerized only with diols and dicarboxylic acids that do not contain sulfo groups, which are the materials for general polyesters. Conductive polyester fibers are further weakened by the alkali in cationic dyeing solutions. In addition, there is a problem that the conductive performance tends to deteriorate during processes such as spinning, warping, knitting, and dyeing, and the lower strength can lead to the conductive paths of conductive carbon black being easily broken, potentially reducing the conductive performance. Furthermore, conductive acrylic fibers have the drawback of being significantly more complicated to manufacture compared to polyester or polyamide fibers. Additionally, voids generated during solvent leaching can affect conductivity, making them unsuitable for applications requiring high conductivity (such as cleanroom wear used in semiconductor manufacturing).
[0005] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a conductive polyamide composite fiber that exhibits less reduction in strength compared to conductive fibers using unmodified resins, has good conductive performance, and has good dyeability not only with cationic dyes but also with acidic dyes. [Means for solving the problem]
[0006] The inventors focused on using a polyamide resin in which a sulfonate-containing triazine derivative reacts with the terminal amino groups of the polyamide resin, thereby introducing sulfonates to some of the terminal amino groups, as the non-conductive layer of a conductive composite fiber. They found that this yields a conductive polyamide composite fiber with good dyeability for cationic and acidic dyes. In other words, the present invention relates to a conductive polyamide composite fiber comprising a non-conductive layer made of a terminal-modified polyamide resin shown in Formula 1, in which some of the hydrogen atoms of the terminal amino groups of the polyamide resin are substituted with a sulfonate-containing triazine derivative, and a conductive layer made of a fiber-forming resin containing a conductive substance, wherein the sulfonate-containing triazine derivative is present in an amount of 0.4 equivalents or more and 1.5 equivalents or less relative to the amount of terminal amino groups of the polyamide resin.
[0007] [ka] (In the formula, PA represents polyamide.) R 1 These are aromatic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups, -NR 2 R 3 -SO3X, or polyamide. R 2 This represents a hydrogen atom or a methyl group. R 3 This represents an aliphatic linear substituent such as an ethylene group or an n-propylene group, or an aromatic substituent such as a phenylene group or a methylphenylene group. X represents a metallic cation such as sodium ion or lithium ion, or an organic cation such as tert-butylammonium ion, benzyltrimethylammonium ion, or p-methylphenylammonium ion.
[0008] Furthermore, it is preferable that the conductive material is one or more selected from conductive carbon black, titanium oxide particles having a conductive coating, and conductive inorganic particles. Furthermore, the ratio of conductive material to fiber-forming resin in the conductive layer is preferably 20% by mass or more and 40% by mass or less in the case of conductive carbon black, and 60% by mass or more and 80% by mass or less in the case of titanium oxide particles and conductive inorganic particles having a conductive coating. Furthermore, it is preferable that the ratio of the conductive layer to the entire fiber cross-section is 3% or more and 50% or less in terms of area ratio. Furthermore, the present invention is also a fibrous structure that uses the above-mentioned conductive polyamide composite fibers in at least a portion of it. [Effects of the Invention]
[0009] The conductive polyamide composite fiber of the present invention can be manufactured industrially easily and inexpensively, can be dyed with cationic and acidic dyes at atmospheric pressure, and exhibits good color development. Therefore, when blended with aramid, acrylic, wool, or silk materials, it can be dyed under the same conditions as the other materials, suppressing static electricity buildup in the product and enabling the provision of fabrics with high design appeal. [Modes for carrying out the invention]
[0010] The present invention relates to a composite fiber comprising a non-conductive layer made of a terminally modified polyamide resin represented by Formula 1, in which some of the hydrogen atoms of the terminal amino groups of the polyamide resin are substituted with a sulfonate-containing triazine derivative, and a conductive layer made of a fiber-forming resin containing a conductive substance.
[0011]
Chemical formula
[0012] The sulfonate-containing triazine derivative contains 0.4 equivalents or more and 1.5 equivalents or less with respect to the amount of terminal amino groups of the polyamide resin. Within this range, the effects of the present invention can be easily obtained. Among them, 0.6 equivalents or more is preferable, and more preferably 0.8 equivalents or more. Also, 1.4 equivalents or less is preferable, and more preferably 1.2 equivalents or less. In addition, from the viewpoint of obtaining good dyeability with both cationic dyes and acid dyes, it is particularly preferable to be 0.8 equivalents or more and 1.0 equivalents or less.
[0013] Examples of the compound that reacts with the terminal amino groups of the polyamide resin include, for example, a sulfonate-containing triazine derivative represented by the following Formula 2.
[0014]
Chemical formula
[0015] R in Equation 2 1′ If the terminal amino group is a halogen atom such as a chloro group or a bromo group, it reacts with the terminal amino group of the polyamide resin to generate a strong acid such as hydrochloric acid, which leads to the decomposition of the polyamide resin and is undesirable. Alkoxy groups such as methoxy, phenoxy, kresoxy, xylenoxy, and naphthoxy groups are preferred because they do not generate a strong acid when reacting with the terminal amino group, and aromatic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups are more preferred because they have good reactivity with the terminal amino group.
[0016] R in Equations 1 and 2 1 For the same reasons as in the previous paragraph, aromatic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups are more preferred. Also, R in formulas 1 and 2 1 R 1 ga-NR 2 R 3 -SO3X may also be used, and may be bonded to the terminal amino group of the polyamide resin as shown in Equation 3 below.
[0017] [ka] (In the formula, R 2 This represents a hydrogen atom or a methyl group. R 3 This represents an aliphatic linear substituent such as an ethylene group or an n-propylene group, or an aromatic substituent such as a phenylene group or a methylphenylene group. X represents a metallic cation such as sodium ion or lithium ion, or an organic cation such as tert-butylammonium ion, benzyltrimethylammonium ion, or p-methylphenylammonium ion.
[0018] R in Equation 2 2 A hydrogen atom or a methyl group is preferred. Bulky substituents are undesirable because they reduce the reaction rate when synthesizing the sulfonate-containing triazine derivative of formula 2.
[0019] R in Equation 2 3 The substituents are preferably aliphatic linear substituents such as ethylene groups and n-propylene groups, or aromatic substituents such as phenylene groups and methylphenylene groups. More preferably, aromatic substituents such as phenylene groups and methylphenylene groups are used because they cause less decrease in resin viscosity after reaction with the compound of formula 2 and react effectively with terminal amino groups.
[0020] In formula 2, X is preferably a metal cation such as a sodium ion or a lithium ion, or an organic cation such as a tert-butylammonium ion, a benzyltrimethylammonium ion, or a p-methylphenylammonium ion. In the case of an organic cation, a somewhat larger decrease in resin viscosity was observed after reaction with formula 2 and the polyamide resin; therefore, a metal cation such as a sodium ion or a lithium ion is more preferable.
[0021] There are no particularly limiting methods for synthesizing the sulfonate-containing triazine derivative of Formula 2, but a method using cyanuryl chloride as a starting material, reacting it with an aminosulfonic acid, and then reacting it with an alcohol to replace the chlorine atoms in the cyanuryl chloride with alkoxy groups is preferred because it offers good reaction efficiency.
[0022] The aminosulfonic acid used in the reaction is preferably, for example, taurine, N-methyltaurine, 3-amino-1-propanesulfonic acid, sulfanilic acid, N-methylsulfanilic acid, aminomethylbenzenesulfonic acid, or 2-((2-aminoethyl)amino)ethylsulfonic acid. More preferably, sulfanilic acid, N-methylsulfanilic acid, or aminomethylbenzenesulfonic acid are used.
[0023] The alcohol used in the reaction is preferably an organic compound containing an aromatic hydroxyl group, such as phenol, cresol, xylenol, or naphthol. More preferably, it is phenol.
[0024] When reacting cyanuric chloride with aminosulfonic acid, it is preferable to use an aqueous solvent. Although aminosulfonic acid is water-soluble, the reactant becomes water-insoluble, making purification easier. Cyanuric chloride is poorly soluble in water but readily soluble in acetone, so a mixed solvent containing water and acetone is more preferable. Furthermore, in the reaction in which alcohol is added to replace chlorine atoms in cyanuryl chloride with alkoxy groups, it is preferable to carry out the reaction in a basic aqueous solution.
[0025] When synthesizing the sulfonate-containing triazine derivative of formula 2, if the molar ratio of cyanuryl chloride is 1, the molar ratio of aminosulfonic acid is preferably 1 or more and 2 or less. As a result, formula 4 or formula 5 is produced, but the larger the molar ratio of aminosulfonic acid, the more of formula 5 is produced. Equation 5 has high water solubility, and the recrystallization yield from water is low, so for better synthesis efficiency, the molar ratio of aminosulfonic acid is preferably 1.0 or higher and 1.2 or lower. Furthermore, since the cationic staining properties of the end-modified polyamide resin using formula 4 and the end-modified polyamide resin using formula 5 were similar, there is no advantage to using formula 5 in terms of staining properties.
[0026] [ka] (In the formula, R 1′ This represents aromatic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups. R 2 This represents a hydrogen atom or a methyl group. R 3 This represents an aliphatic linear substituent such as an ethylene group or an n-propylene group, or an aromatic substituent such as a phenylene group or a methylphenylene group. X represents a metallic cation such as sodium ion or lithium ion, or an organic cation such as tert-butylammonium ion, benzyltrimethylammonium ion, or p-methylphenylammonium ion.
[0027] [ka] (In the formula, R 1′ This represents aromatic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups. R 2 This represents a hydrogen atom or a methyl group. R 3 These are aliphatic linear substituents such as ethylene groups and n-propylene groups, or aromatic substituents such as phenylene groups and methylphenylene groups. X represents a metallic cation such as sodium ion or lithium ion, or an organic cation such as tert-butylammonium ion, benzyltrimethylammonium ion, or p-methylphenylammonium ion.
[0028] In the present invention, a preferred method for producing a terminally modified polyamide resin in which a sulfonate salt is introduced to the terminal amino group is to melt-knead a sulfonate-containing triazine derivative and a polyamide resin. The melt-kneading temperature is preferably 240°C or higher and 280°C or lower.
[0029] When producing a terminally modified polyamide resin in which a sulfonate salt is introduced to the terminal amino group of Formula 1, the polyamide resin used is preferably a polymer or copolymer thereof of polyamide 6 (hereinafter sometimes referred to as PA6), polyamide 12, polyamide 66, etc., and polyamide 6 is particularly suitable when used for clothing applications.
[0030] The amount of terminal amino groups in commonly used polyamide resins is approximately 30-40 meq / kg. In the polyamide resin used in the present invention, an amino group amount within this range is acceptable, but preferably it is 60 meq / kg or more. More preferably it is 80 meq / kg or more.
[0031] The relative viscosity of the polyamide resin used in this invention is preferably 2.20 or higher and 4.20 or lower. If the relative viscosity is any other, yarn breakage occurs frequently during melt spinning, spinning filterability is poor, and the spinneret life is shortened, resulting in poor operability. More preferably, the relative viscosity is 2.30 or higher and 3.60 or lower.
[0032] The preferred mixing ratio of the sulfonate-containing triazine derivative is 0.4 equivalents or more and 1.5 equivalents or less relative to the amount of terminal amino groups in the polyamide resin. If the amount is less than 0.4 equivalents, the sulfonate is not sufficiently introduced to the terminal amino groups, and if it is added in amounts exceeding 1.5 equivalents, no decrease in the amount of terminal amino groups is observed, and the reaction efficiency does not improve. More preferably, the ratio is 0.6 equivalents or more and 1.2 equivalents or less, and even more preferably, 0.8 equivalents or more and 1.0 equivalent or less, because good dyeing properties are observed with both cationic and acidic dyes.
[0033] The conductive material contained in the conductive layer is preferably one or more selected from conductive carbon black, titanium oxide with a conductive coating, and conductive inorganic particles. As a result, the composite conductive fiber has conductive properties, and when used in combination with acrylic fibers to make clothing and worn, it generates almost no static electricity. For better aesthetic reasons, titanium oxide with a conductive coating or conductive inorganic particles are more preferable, and considering cost, titanium oxide with a conductive coating is the most preferable.
[0034] Examples of conductive titanium oxide coatings include metal coatings. However, metal coatings have the disadvantage of being unstable and easily degraded by oxidation. Some metal oxides are stable and conductive, such as copper oxide, silver oxide, zinc oxide, cadmium oxide, antimony oxide, tin oxide, and manganese oxide. However, since metal oxides alone may not exhibit sufficient conductivity, it is preferable to use these metal oxides as the main component and add a small amount of a secondary component. Suitable combinations of the main and secondary components include, for example, copper oxide / copper, zinc oxide / aluminum oxide, tin oxide / antimony oxide, zinc oxide / zinc, aluminum oxide / aluminum, tin oxide / tin, and antimony oxide / antimony.
[0035] The conductive coating on titanium oxide particles can be formed, for example, by vacuum deposition, by depositing a metal compound (e.g., an organic acid salt) and then firing it to form an oxide, or by partial reduction of the oxide.
[0036] The conductive material has a resistivity of 9.9 × 10 in powder form. 4 Ω cm or less, especially 9.9×10 2 A value of Ω·cm or less is preferable.
[0037] The resistivity of the above conductive material is measured by filling a 1 cm diameter cylinder with 10 g of sample, applying a pressure of 200 kg from the top using a piston, and applying a direct current (0.1 to 100 V).
[0038] As the fiber-forming resin that forms the conductive layer, known thermoplastic polymers that form a fibrous shape when melt-spun can be used. Examples include polyamide, polyester, polyolefin, and polycarbonate.
[0039] The content ratio of conductive material to fiber-forming resin in the conductive layer is preferably 20% by mass or more and 40% by mass or less in the case of conductive carbon black, and 60% by mass or more and 80% by mass or less in the case of titanium oxide particles or conductive inorganic particles having a conductive coating. If the content ratio is within the above range, the conductive performance is good.
[0040] In the conductive polyamide composite fiber of the present invention, the ratio of the conductive layer to the entire fiber cross-section in the fiber cross-section is preferably 3% or more and 50% or less in terms of area ratio. If the ratio of the conductive layer exceeds 50%, the strength decreases significantly, and spinning and winding tend to become difficult. Also, if the ratio of the conductive layer is less than 3%, the conductivity is insufficient, and it tends to be difficult to exhibit conductive performance. More preferably, it is 4% or more and 40% or less.
[0041] In the conductive polyamide composite fiber of the present invention, the fiber cross-sectional shape is not particularly limited, as conductivity is greatly influenced by the ratio of the conductive layer. However, preferred structures include a core-sheath structure, a sea-island structure, a side-by-side structure, and a hamburger-type structure. Since the exposed area of the conductive layer also affects conductivity, it is more preferable that the sheath portion has a core-sheath structure with the conductive layer.
[0042] Furthermore, the fiber-forming resin containing the conductive material for the conductive layer in the present invention can be obtained by mixing the fiber-forming resin used for the conductive layer with the conductive material. Here, the method for mixing the resin used in the conductive layer of the conductive polyamide composite fiber of the present invention with conductive substances such as conductive carbon black, titanium oxide having an electrolytic coating, and conductive inorganic particles is not particularly limited and can be mixed by known methods such as the twin-screw compounding method.
[0043] The conductive polyamide composite fiber of the present invention can be manufactured by composite spinning using a fiber-forming resin containing a conductive substance in the conductive layer and the above-mentioned end-modified polyamide resin in the non-conductive layer. As a composite spinning method, a melt spinning method is preferred, in which a fiber-forming resin containing a conductive substance and a terminal-modified polyamide resin are melted in an extruder, each resin is extruded from a die while being measured using a gear pump, and then wound up after cooling. The spinning temperature is preferably above the melting point of each resin and below 300°C. As for winding methods, for example, a method in which the undrawn yarn is wound once at a low speed of about 400 to 1,200 m / min and then heat-stretched using a twisting machine to obtain a drawn yarn (conventional method), a method in which the yarn is wound at a high speed of 3,000 to 5,000 m / min to obtain a semi-drawn yarn (POY method), or a method in which a first roller (GR1) of 800 to 1,200 m / min and a second roller (GR2) of about 3,000 to 4,500 m / min are used to perform heat stretching between GR1 and GR2 to obtain a directly drawn yarn (direct stretching method). While there are no particular limitations on the stretching ratio, it is generally preferable to have a ratio of 2 to 4 times.
[0044] The fineness and number of fibers of the conductive polyamide composite fiber of the present invention are not particularly limited, but for clothing applications, a total fineness of 18 to 500 dtex and a number of fibers of approximately 1 to 96 f are preferred, and more preferably a total fineness of 20 to 400 dtex and a number of fibers of 1 to 72 f are preferred.
[0045] The conductive polyamide composite fiber of the present invention can be used as a filament yarn as is, or as a yarn made by blending cut staple yarn with other staple yarns, in woven or knitted fabrics. Woven or knitted fabrics can be suitably used for clothing such as general clothing, sportswear, work clothes, and protective clothing, as well as for bedding, vehicle interior materials, etc. As an example of a suitable use, when used in general clothing, sportswear, work clothes, protective clothing, etc., it can be used as a fiber structure consisting of a fabric made of yarn with a blended yarn (core yarn) of functional yarn having properties such as cooling sensation or flame retardancy and cotton, and the polyamide composite fiber of the present invention as a covering yarn (sheath yarn). In this case, the polyamide composite fiber of the present invention may be used alone as the covering yarn (sheath yarn), or a yarn may be made by covering or twisting the polyamide composite fiber of the present invention with other polyamide yarns, etc.
[0046] The composite fibers of the present invention may be used in part or all of a woven or knitted fabric. When used in part, the specific usage ratio is preferably 0.1% by mass or more, and more preferably 0.3% by mass or more, of the composite fibers of the present invention. [Examples]
[0047] The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Each evaluation was performed as described below.
[0048] (1) Resin viscosity measurement An Ubbelohde viscometer was used to measure the relative viscosity of the polyamide resin. A solution of polyamide resin dissolved in 96.0% sulfuric acid at a concentration of 0.01 g / mL was prepared. The time it took for the solution to fall from the top to the bottom of the measurement mark at 25°C was measured. Three trials were performed, and the average value was taken. ave The following was done: The time it took for 96.0% by mass sulfuric acid to fall from the top to the bottom of the measurement mark at 25°C was measured three times, and the average value was taken as t0. The relative viscosity was calculated using the following formula.
[0049]
number
[0050] (2) Measurement of terminal amino group content of polyamide resin The polyamide resin was dissolved in a phenol-methanol mixed solvent at a concentration of 0.05 g / mL, and then an indicator (0.04% thymol blue) was added. The solution was then titrated with 0.02 mol / L HCl. The volume of titration until the solution changed from yellow to red was defined as A (mL). An indicator (0.04% thymol blue) was added to a phenol-methanol mixed solvent and titrated with 0.02 mol / L HCl. The volume of titration until the solution changed from yellow to red was defined as B (mL). The amount of terminal amino groups was calculated using the following formula.
[0051]
number
[0052] (3) Synthesis evaluation NMR analysis for the identification of organically synthesized sulfonate-containing triazine derivatives was performed using a BRUKER NMR spectrometer.
[0053] (4) Measurement of fiber breaking strength and elongation at break The tensile strength and elongation of conductive polyamide composite fibers were determined in accordance with JIS L 1013, using a Shimadzu AGS-1KNG Autograph® tensile testing machine, under the conditions of a sample yarn length of 20 cm and a tensile speed of 20 cm / min, by measuring the strength and elongation when the sample fractured under stretching conditions.
[0054] (5) Measurement of the conductivity of fibers (linear resistance value) The linear resistance was calculated by taking a 10 cm section of conductive polyamide composite fiber, attaching aluminum foil to both ends with conductive adhesive, and measuring the resistance (Ω) using an Agilent 4339B high-resistance meter. The resistance value was then divided by the distance between the electrodes (cm) to obtain the linear resistance value (Ω / cm).
[0055] (6) Stainability For dyeability, two types of comparative samples were prepared: a conductive polyamide composite fiber using a non-terminal modified polyamide resin in the non-conductive layer (hereinafter referred to as the polyamide control yarn), and a conductive polyester composite fiber using an atmospheric pressure cationic polyester resin in the non-conductive layer (hereinafter referred to as the atmospheric pressure cationic polyester control yarn). Using each of these, 8 cm wide tubular knitted fabrics were produced on a tubular knitting test machine (CR-B, 24 gauge, manufactured by Eiko Sangyo Co., Ltd.). The obtained tubular knitted fabrics were scouring at 70°C for 20 minutes using an aqueous solution of 2 g / L sodium bicarbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 2 g / L polyoxyethylene alkyl ether (manufactured by Kao Corporation). Hereinafter, the tubular knitted fabric of the present invention will be referred to as the sample, the tubular knitted fabric of the polyamide control yarn as the PA control, and the tubular knitted fabric of the atmospheric pressure cationic polyester control as the PE control. Cationic staining and acidic staining were performed using the scouring-treated sample, PA control sample, and PE control sample. Samples were prepared for cation staining at atmospheric pressure at 98°C with a bath ratio of 1:30 using the cationic dye Kayacryl Blue GSL-ED (manufactured by Nippon Kayaku Co., Ltd.) 2% owf, anhydrous sodium sulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 3 g / L, and acetic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 1 mL / L. Samples were prepared for acidic staining at atmospheric pressure at 98°C with a bath ratio of 1:30 using the acidic dye Nylosan blue N-KN 130% (manufactured by Arkroma Co., Ltd.) 2% owf, ammonium sulfate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 1 g / L, and acetic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.5 mL / L, and a bath ratio of 1:30. Before and after dyeing, the color of the samples was measured using a colorimeter (ZE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.) to determine the color before and after dyeing (L * ,a * ,b * ) was confirmed. Multiple E * The (ab) value is calculated using the following formula, and the resulting E * The staining rate was calculated from the (ab) values and the staining properties were evaluated. [Mathematics 3] ·E * (ab)(This sample after cation staining) = √{(L of this sample before and after cation staining)* (Difference in values) 2 +(a of this sample before and after cation staining) * (Difference in values) 2 +(b before and after cation staining of this sample) * (Difference in values) 2} [Mathematics 4] ·E * (ab)(Acid-stained sample) = √{(L of the sample before and after acid staining) * (Difference in values) 2 +(a of this sample before and after acid staining) * (Difference in values) 2 +(b before and after acid staining of this sample) * (Difference in values) 2} [Math 5] ·E * (ab) (PA control stained with acid) = √{(L of PA control before and after acid staining) * (Difference in values) 2 +(PA control a before and after acid staining) * (Difference in values) 2 +(b before and after acid staining of PA control) * (Difference in values) 2} [Mathematics 6] ·E * (ab) (Cation-stained PE control) = √{(L of PE control before and after cation staining) * (Difference in values) 2 +(a before and after cation staining of PE control) * (Difference in values) 2 +(b before and after cation staining of PE control) * (Difference in values) 2} [Mathematics 7] • Cation staining rate = E * (ab) (This sample stained with cations) / E * (ab) (Cation-stained PE control) ·Acid staining rate=E * (ab) (Acid-stained sample) / E * (ab) (PA control stained with acid) Cationic and acidic staining properties were evaluated according to the following criteria. ◎: The staining rate is between 0.8 and 1.0. ○: The staining rate is 0.7 or higher and less than 0.8. △: The staining rate is 0.4 or higher but less than 0.7. ×: The staining rate is less than 0.4.
[0056] [Organic Synthesis Example 1] Sodium-4-(4,6-diphenoxy-1,3,5-triazinyl-2-amino)benzenesulfonate (hereinafter referred to as organic compound 1) was synthesized by the following method. 18.5 g of cyanuric chloride (Sigma-Aldrich) was dissolved in 40 ml of acetone (Fujifilm Wako Pure Chemical Industries, Ltd.), and this was added to 60 ml of ice water while vigorously stirring with a stirrer. To the resulting slurry, 100 ml of aqueous solution of 17.3 g of sulfanilic acid (Fujifilm Wako Pure Chemical Industries, Ltd.) and 5.3 g of sodium carbonate (Fujifilm Wako Pure Chemical Industries, Ltd.) was added for a short time under ice cooling and the reaction was allowed to proceed. Furthermore, 20 ml of aqueous solution of 5.3 g of sodium carbonate was gradually added to maintain the pH at 7-8. After 2 hours of reaction, the precipitated material was filtered off and thoroughly washed with water. After further washing with acetone and drying under reduced pressure at room temperature, 27.1 g of a white solid was obtained. 17 g of the obtained white solid was suspended in 75 ml of acetone by vigorously stirring, and 125 ml of aqueous solution of 9.4 g of phenol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 4.2 g of sodium hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added at approximately 10°C and reacted for 30 minutes. The precipitated material was filtered off, thoroughly washed with water, recrystallized from hot water, and then dried under reduced pressure to obtain 16.8 g of white solid (organic compound 1). NMR measurements of the obtained organic compound 1 revealed proton peaks for phenylene (sodium sulfanilate) and phenol at concentrations of 7.0–7.5 ppm.
[0057] [Organic Synthesis Example 2] Sodium-2-(4,6-diphenoxy-1,3,5-triazinyl-2-amino)ethanesulfonate (hereinafter referred to as organic compound 2) was synthesized by the following method. Using the same method as in Organic Synthesis Example 1, 12.5 g of taurine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was reacted instead of sulfanilic acid to obtain 15.0 g of a white solid (organic compound 2). NMR measurements of the obtained organic compound 2 revealed a phenol proton peak at 7.0–7.5 ppm and a methyl taurine proton peak at 2.5–3.5 ppm.
[0058] [Mixing Example 1] 6.5 kg of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd., relative viscosity: 2.43, terminal amino group content: 40 meq / kg) was mixed with 92.0 g of organic compound 1 (molar amount: 0.21 mol, 0.8 equivalents relative to the terminal amino group content of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd.)). This mixture was supplied to a twin-screw extruder kneader (manufactured by Shibaura Machinery Co., Ltd.) at a rate of 10.0 kg / hr via a feeder (manufactured by Kubota) and melt-kneaded at 260°C. The cord-like molten material was water-cooled and pelletized using a pelletizer to obtain 3.5 kg of resin composition (1). The relative viscosity of the resin composition (1) obtained here was measured to be 2.44.
[0059] [Mixing Example 2] The process was carried out in the same manner as in kneading example 1, except that 103.5 g of organic compound 1 was used (molar amount: 0.24 mol, 0.6 equivalents relative to the amount of terminal amino groups of polyamide 6), and 3.5 kg of resin composition (2) was obtained. The relative viscosity of the resin composition (2) obtained here was measured to be 2.44.
[0060] [Mixing Example 3] The process was carried out in the same manner as in kneading example 1, except that 172.5 g of organic compound 1 was used (molar amount: 0.40 mol, 1.0 equivalent relative to the amount of terminal amino groups of polyamide 6), and 3.5 kg of resin composition (3) was obtained. The relative viscosity of the resin composition (3) obtained here was measured to be 2.43.
[0061] [Mixing Example 4] The process was carried out in the same manner as in kneading example 1, except that 138.0 g of organic compound 1 was used (molar amount: 0.32 mol, 1.2 equivalents relative to the amount of terminal amino groups of polyamide 6), and 3.5 kg of resin composition (4) was obtained. The relative viscosity of the resin composition (4) obtained here was measured to be 2.42.
[0062] [Mixing Example 5] The process was carried out in the same manner as in kneading example 1, except that 172.5 g of organic compound 1 was used (molar amount: 0.39 mol, 1.5 equivalents relative to the amount of terminal amino groups of polyamide 6), and 3.5 kg of resin composition (5) was obtained. The relative viscosity of the resin composition (5) obtained here was measured to be 2.38.
[0063] [Mixing Example 6] The process was carried out in the same manner as in kneading example 1, except that 46.0 g of organic compound 1 (molar amount: 0.11 mol, 0.4 equivalents relative to the amount of terminal amino groups of polyamide 6) was used to obtain 3.5 kg of resin composition (6). The relative viscosity of the resin composition (6) obtained here was measured to be 2.45.
[0064] [Mixing Example 7] The process was carried out in the same manner as in kneading example 1, except that 206.0 g (molar amount: 0.47 mol, 0.8 equivalents relative to the amount of terminal amino groups in polyamide 6 (manufactured by Ube Industries, relative viscosity: 2.50, amount of terminal amino groups: 90 meq / kg) of organic compound 1 was added to 6.5 kg of resin composition (7). The relative viscosity of the resin composition (7) obtained here was measured to be 2.48.
[0065] [Mixing Example 8] The process was carried out in the same manner as in kneading example 1, except that 87.0 g of organic compound 2 (molar amount: 0.21 mol, 0.8 equivalents relative to the amount of terminal amino groups in polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd., relative viscosity: 2.43, terminal amino group amount: 40 meq / kg) was added to 6.5 kg of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd.), and 3.5 kg of resin composition (8) was obtained. The relative viscosity of the resin composition (8) obtained here was measured to be 2.39.
[0066] [Mixing Example 9] The process was carried out in the same manner as in kneading example 1, except that 130.5 g of organic compound 2 was used (molar amount: 0.32 mol, 1.2 equivalents relative to the amount of terminal amino groups of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd.)), to obtain 3.5 kg of resin composition (9). The viscosity of the resin composition (9) obtained here was measured relative to 2.23.
[0067] [Mixing Example 10] The process was carried out in the same manner as in kneading example 1, except that 207.0 g of organic compound 1 (molar amount: 0.47 mol, 1.8 equivalents relative to the amount of terminal amino groups of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd.)) was used to obtain 3.5 kg of resin composition (10). The relative viscosity of the resin composition (10) obtained here was measured to be 2.32.
[0068] [Mixing Example 11] The process was carried out in the same manner as in kneading example 1, except that 23.0 g of organic compound 1 (molar amount: 0.06 mol, equivalent to 0.2 equivalents relative to the amount of terminal amino groups of polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd.)) was used to obtain 3.5 kg of resin composition (11). The relative viscosity of the resin composition (11) obtained here was measured to be 2.45.
[0069] [Example 1] A composite spinning process was carried out using an extruder-type composite spinning machine at a temperature of 240°C, using resin composition (1) and polyethylene (referred to as C-PE) having 75% by mass of titanium oxide particles coated with antimony oxide and tin oxide as spinning raw materials. The resin composition (1) was melted separately so that the sheath and C-PE formed the core. The resulting mixture was then spun from a core-sheath spinning die at 240°C, cooled, and oiled while being wound up at a spinning speed of 1,400 m / min. Subsequently, it was heat-stretched to 2.8 times its original size at 60°C using a stretcher, and then heat-set at 150°C using a plate heater to obtain a core-sheath composite fiber with a drawn yarn of 22 dtex / 6 f. The core-sheath ratio of this core-sheath composite fiber is 1:20 (area ratio). The resulting fiber had a breaking strength of 3.5 cN / dtex, a breaking elongation of 32.6%, and a linear resistance of 3.8 × 10⁻⁶. 9 The Ω / cm ratio was 0.83 for cationic staining and 0.83 for acidic staining.
[0070] [Example 2] The spinning process was carried out in the same manner as in Example 1, except that resin composition (1) was replaced with resin composition (2), to obtain a core-sheath type composite fiber that was a drawn yarn with a density of 22 dtex / 6 f. The resulting fiber had a breaking strength of 3.6 cN / dtex, a breaking elongation of 34.7%, and a linear resistance of 4.0 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.80, and acidic staining was 0.84.
[0071] [Example 3] Except for replacing resin composition (1) with resin composition (3), the spinning procedure was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber with a drawn yarn of 22 dtex / 6 f. The resulting fiber had a breaking strength of 3.5 cN / dtex, a breaking elongation of 35.6%, and a linear resistance of 3.6 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.85, and acidic staining was 0.81.
[0072] [Example 4] Except for replacing resin composition (1) with resin composition (4), the spinning procedure was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber with a drawn yarn of 22 dtex / 6f. The resulting fiber had a breaking strength of 3.4 cN / dtex, a breaking elongation of 34.9%, and a linear resistance of 4.1 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.89, and acidic staining was 0.71.
[0073] [Example 5] Except for replacing resin composition (1) with resin composition (5), the spinning procedure was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber with a drawn yarn of 22 dtex / 6 f. The resulting fiber had a breaking strength of 3.2 cN / dtex, a breaking elongation of 32.5%, and a linear resistance of 3.5 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.90, and acidic staining was 0.43.
[0074] [Example 6] Except for using resin composition (6) instead of resin composition (1), spinning was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber that was a drawn yarn with 22 dtex / 6f. The resulting fiber had a breaking strength of 3.6 cN / dtex, a breaking elongation of 36.7%, and a linear resistance of 2.8 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.48, and acidic staining was 0.90.
[0075] [Example 7] Except for replacing resin composition (1) with resin composition (7), the spinning procedure was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber with a drawn yarn of 22 dtex / 6 f. The resulting fiber had a breaking strength of 3.1 cN / dtex, a breaking elongation of 33.7%, and a linear resistance of 5.1 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.91, and acidic staining was 0.92.
[0076] [Example 8] Except for replacing resin composition (1) with resin composition (8), the spinning procedure was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber with a drawn yarn of 22 dtex / 6 f. The resulting fiber had a breaking strength of 3.0 cN / dtex, a breaking elongation of 32.6%, and a linear resistance of 5.2 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.82, and acidic staining was 0.86.
[0077] [Example 9] Spinning was carried out in the same manner as in Example 1, except that resin composition (1) was replaced with resin composition (9), to obtain a core-sheath type composite fiber which is a drawn yarn with 22 dtex / 6 f. The resulting fiber had a breaking strength of 2.9 cN / dtex, a breaking elongation of 35.2%, and a linear resistance of 6.4 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.91, and acidic staining was 0.73.
[0078] [Comparative Example 1] Spinning was carried out in the same manner as in Example 1, except that resin composition (1) was replaced with resin composition (10), to obtain a core-sheath type composite fiber. The resulting fiber had a breaking strength of 3.0 cN / dtex, a breaking elongation of 31.2%, and a linear resistance of 4.5 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.94, and acidic staining was 0.32.
[0079] [Comparative Example 2] Spinning was carried out in the same manner as in Example 1, except that resin composition (1) was replaced with resin composition (11), to obtain a core-sheath type composite fiber. The resulting fiber had a breaking strength of 3.3 cN / dtex, a breaking elongation of 33.3%, and a linear resistance of 3.0 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.36, and acidic staining was 0.92.
[0080] [Comparative Example 3] Except for using polyamide 6 (manufactured by Ji Sheng Industrial Co., Ltd., relative viscosity: 2.43, terminal amino group content: 40 meq / kg) as the resin composition (1), spinning was carried out in the same manner as in Example 1 to obtain a core-sheath type composite fiber. The resulting fiber had a breaking strength of 3.3 cN / dtex, a breaking elongation of 35.3%, and a linear resistance of 2.7 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 0.30, and acidic staining was 1.00.
[0081] [Comparative Example 4] The resin composition (1) was a polyester copolymer of metal sulfonate group-containing isophthalic acid and polyalkylene glycol (manufactured by KB Seiren, intrinsic viscosity: 0.54), and the spinning temperature was 280°C and the spinning speed was 1,400 m / min, except that it was wound up in the same manner as in Example 1. Then, it was heat-stretched to 2.7 times its original size at 95°C using a stretcher, and then heat-set at 150°C using a plate heater to obtain a core-sheath type composite fiber which was a drawn yarn of 22 dtex / 6f. The resulting fiber had a breaking strength of 2.9 cN / dtex, a breaking elongation of 32.5%, and a linear resistance of 2.6 × 10⁻⁶. 9 The values were Ω / cm, cationic staining was 1.00, and acidic staining was 0.27.
[0082] Tables 1 and 2 show the core resin, sheath resin, and the properties and evaluation results of the core-sheath composite fibers used in the examples and comparative examples. Note that the amount added relative to the terminal amino group amount of the sheath resin in the table represents the content of the sulfonic acid base-containing triazine derivative in the sheath resin.
[0083] [Table 1]
[0084] [Table 2]
[0085] From the results described above, the fibers obtained from Examples 1 to 7, in which the content of sulfonate-containing triazine derivative was between 0.4 equivalents and 1.5 equivalents relative to the amount of terminal amino groups in the polyamide resin, exhibited good cationic and acidic staining properties. In particular, the fibers obtained from Examples 1, 2, 3, 7, and 8, in which the content of sulfonate-containing triazine derivative was between 0.6 equivalents and 1.0 equivalents relative to the amount of terminal amino groups in the polyamide resin, exhibited particularly good cationic and acidic staining properties. [Industrial applicability]
[0086] The conductive composite fiber of the present invention is a conductive polyamide composite fiber that can be dyed using both atmospheric pressure cation dyeing and acid dyeing, has good color development, and can suppress static electricity buildup, and is suitable for use in combination with acrylic fibers and polyamide fibers.
Claims
1. A method for producing a conductive polyamide composite fiber comprising a non-conductive layer made of a terminal-modified polyamide resin shown in Formula 1, in which some of the hydrogen atoms of the terminal amino groups of the polyamide resin are substituted with a sulfonate-containing triazine derivative, and a conductive layer made of a fiber-forming resin containing a conductive substance, wherein the content of the sulfonate-containing triazine derivative is 0.4 equivalents or more and 1.5 equivalents or less with respect to the amount of terminal amino groups of the polyamide resin, To synthesize a sulfonate-containing triazine derivative by reacting a reaction product of cyanuryl chloride and aminosulfonic acid with an alcohol, A terminally modified polyamide resin of formula 1, in which a sulfonate salt is introduced into the terminal amino groups, is produced by melt-kneading the sulfonate-containing triazine derivative and the polyamide resin such that the content of the sulfonate-containing triazine derivative is 0.4 equivalents or more and 1.5 equivalents or less relative to the amount of terminal amino groups of the polyamide resin. A manufacturing method comprising melt spinning, wherein the end-modified polyamide resin is used as a non-conductive layer and a fiber-forming resin containing a conductive substance is used as a conductive layer. [Formula 1] (In the formula, PA represents polyamide.) R １ These are phenolic hydroxyl groups such as phenoxy, kresoxy, xylenoxy, and naphthoxy groups, -NR ２ R ３ -SO ３ X indicates polyamide. R ２ This represents a hydrogen atom or a methyl group. R ３ This represents an aliphatic linear substituent such as an ethylene group or an n-propylene group, or an aromatic substituent such as a phenylene group or a methylphenylene group. X represents a metallic cation such as sodium ion, magnesium ion, manganese ion, or lithium ion, or an organic cation such as tert-butylammonium ion, benzyltrimethylammonium ion, or p-methylphenylammonium ion.
2. A method for producing conductive polyamide composite fibers according to claim 1, wherein the conductive material is one or more selected from conductive carbon black, titanium oxide particles having a conductive coating, and conductive inorganic particles.
3. A method for producing conductive polyamide composite fibers according to claim 1 or 2, wherein the content ratio of the conductive substance to the fiber-forming resin in the conductive layer is 20% by mass or more and 40% by mass or less in the case of conductive carbon black, and 60% by mass or more and 80% by mass or less in the case of titanium oxide particles or conductive inorganic particles having a conductive coating.
4. A method for producing conductive polyamide composite fibers according to any one of claims 1 to 3, wherein the ratio of the conductive layer to the entire fiber cross-section in the fiber cross-section is 3% or more and 50% or less in terms of area ratio.