JP2013036147A - Polyamide crimped yarn and carpet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyamide crimped yarn suitable for a carpet, in which the polyamide crimped yarn has excellent crimp characteristics, good feeling when stepping on, and excellent compressive elastic recovery ratio, and is hard to set, by using a polyamide composition with good crystallinity in a process of forming a fiber structure although a small amount of spherulites are formed therein.SOLUTION: A polyamide crimped yarn comprises a polyamide composition including a polyamide comprising a hexamethylene adipamide unit and satisfying the following formulae (1)-(3), and has the following fiber characteristics (A)-(E). (1) Tc(270)-Tc(300)≥15°C, (2) Tc(300)≤188°C, Tc(270)≥200°C, and (3) Tm≥260°C, where Tc(T) represents a crystallization peak temperature on cooling down as measured by melting at a temperature of T°C and Tm represents a melting point. (A) filament fineness=400 to 4000 dtex, (B) single filament fineness=3 to 100 dtex, and (C) strength=2.0 to 5.5 cN/dtex, (D) boiling water shrinkage percentage=2 to 10%, and (E) crimp elongation percentage=12 to 22%.

Description

  The present invention relates to a polyamide crimped yarn and a carpet composed of a polyamide composition, which is suitable as a polyamide crimped yarn for tufted carpets, has less spherulite formation and exhibits a unique crystallization behavior. More specifically, since the formation of spherulites is small despite the fact that the single yarn fineness is large, it has excellent crimp characteristics, and when used as a tufted carpet, it feels good when stepped on and has an excellent compression elastic recovery rate. More particularly, the present invention relates to a polyamide crimped yarn suitable for a high-grade carpet such as a saxony twisted crimped cut-cut pile carpet and a carpet comprising the same. Furthermore, the present invention relates to a polyamide crimped yarn that is excellent in drawability and crimp processability, has little yarn breakage, and has an excellent yarn production yield when producing crimped yarn.

  Polyamide fibers are useful as crimped yarns for carpets, taking advantage of their crimping properties, durability such as set resistance and abrasion resistance, and easy dyeability.

  In particular, polyhexamethylene adipamide (hereinafter referred to as nylon 66) fiber has a high melting point and excellent heat resistance among the commonly used polyamide fibers. For example, it can be crimped at a higher temperature than nylon 6 fiber. Not only has excellent crimp characteristics, but also has excellent characteristics such as high crimpability and high resilience, so that when used as a carpet, it has excellent covering properties, treading resistance, and set resistance. .

  However, since nylon 66 has a high crystallization rate, spherulites are likely to be generated during spinning cooling, and particularly when a single-filament fine yarn that is difficult to cool is produced, spherulites tend to be remarkably generated.

  The crimped yarn for carpets has a particularly large single yarn fineness, usually 10 to 30 dtex, which is much thicker than the number dtex of general clothing fibers and 3 to 7 dtex of industrial fibers. However, when spherulites are generated in the fiber, it is difficult to draw, so it is usually difficult to produce high-strength fibers, but even in the case of crimped yarn, sufficient molecular chain orientation is not achieved in the drawing process. There is a problem that sufficient crimping is not performed in the crimping process, and high crimping characteristics cannot be obtained. Furthermore, if you try to use it as a high-grade carpet such as a saxony twisted crimped carpet that performs steam setting after twisting, it is inferior in twist setability, such as insufficient pinpoint property, volume feeling, and resilience There is. In addition, when spherulites are remarkably generated, there is a possibility that the transparency is lost and there is a disadvantage that the color is not clearly developed even when dyed. In addition, if a large amount of spherulites are generated, more severe drawing conditions and crimping conditions must be applied in order to obtain the desired crimped yarn. There is also a drawback that the yield is reduced due to the decrease in the properties, yarn breakage.

  The main causes of the formation of spherulites in nylon 66 fiber are as follows.

  That is, in the polymerization process and the melt spinning process of the polyamide polymer, the polyamide polymer is thermally decomposed, fine foreign matters generated by the thermal decomposition become spherulite nuclei, and additives such as heat-resistant agents and colorants are thermally decomposed. Is to produce minute foreign matters, which become spherulite nuclei. In particular, during polymerization and melt spinning, the flow of the polymer is poor and it stays for a long time, so that the polymer itself is thermally decomposed and gelled to generate minute foreign substances that become spherulite nuclei. In addition to the formation of the above spherulite nuclei, the spherulite formation also depends on the crystallization rate of the polyamide polymer because spherulites are formed by crystal growth. In particular, since nylon 66 has a high crystallization speed, the formation of spherulites and the resulting yarn-making trouble are remarkable. Thus, as techniques for suppressing the formation of spherulites, methods such as the addition of a thermal decomposition and gelation inhibitor, a method of reducing the crystallization rate by copolymerizing a small amount of a copolymer component, and the like are performed. In addition, a method has been proposed in which a specific copolymer component is added to obtain a copolyamide that hardly gels even if thermal decomposition occurs.

  Further, as another method for suppressing spherulites, a spinning technique in which quenching is performed in the spinning cooling process and the crystallization temperature range is passed in a short time is generally applied.

  Therefore, for the purpose of suppressing the spherulite to improve the yarn-making property and producing a high-quality polyamide fiber, a method of suppressing the spherulite by using a copolymerized polyamide and reducing the crystallization rate of the polymer, and For example, the following four methods have been proposed with respect to a method of suppressing spherulite by suppressing thermal decomposition and gelation of a polyamide polymer.

  First, a ternary polyamide containing 2-methylpentamethylenediamine and other amide units is used for the purpose of improving the spinning property by suppressing the spherulites (spherical aggregates) of nylon 66 and increasing the gel time. There are known multi-component polyamides and methods for producing products produced therefrom (see, for example, Patent Document 1). According to this method, spherulite formation can be reduced and gelation time can be increased. It is disclosed that useful effects such as stretchability, optical transparency, and dyeing speed can be obtained.

  However, the copolymer polymer produced by the technique described in Patent Document 1 has a relatively large melting point drop, and even in the examples of the same document, the melting point drop is the smallest at 2.1 ° C., and most often 5 to 10 ° C. It is descending. Such a melting point drop may not be a significant disadvantage in the performance of ordinary carpet BCF products, but it cannot be crimped at a high temperature such as nylon 66 homopolymer crimped yarn, and a high crimped yarn can be obtained. It becomes difficult to obtain. In particular, when a saxony twisted crimped yarn is used, it is difficult to obtain a high-quality carpet with poor twisted steam set property and high pinpoint property and resilience. That is, in the method described in Patent Document 1, although the formation of spherulites is suppressed, the crystallinity at the time of forming the fiber structure also decreases, and the excellent characteristics of the nylon 66 crimped yarn are lost. was there.

  Next, an object of the present invention is to provide nylon 66 fibers that suppress spherulite of nylon 66 fibers for BCF carpets, have a smooth filament surface, and can be dyed at room temperature. A method achieved by copolymerizing nylon 6 in a small amount (for example, see Patent Document 2), more specifically, 94-96% hexamethylene adipamide, 1-6% caprolactam, water-soluble inorganic A method of applying N66 copolymer polyamide containing 0.001 to 2% of calcium salt is known.

  The technique described in Patent Document 2 is characterized in that the crystallization speed of nylon 66 is reduced by copolymerizing caprolactam, and according to this method, the single yarn fineness is thick like BCF for carpets. In fibers that are difficult to cool, the effect of suppressing spherulite is noticeable. However, the method of copolymerizing caprolactam has a great effect of suppressing spherulite, but at the same time the melting point of the polymer is greatly reduced. Although not specifically described in Patent Document 2, the copolymer nylon 66 obtained there is difficult to obtain a high crimp unique to N66 crimped yarn as in the case of Patent Document 1, and saxony. When used as a twisted crimped yarn, the pinpoint property and the resilience were inferior, and there was a problem that sufficient quality for a high-grade carpet could not be obtained.

  In addition, it aims to improve the thermal stability of polyamides containing polyhexamethylene adipamide as the main constituent, to suppress gel formation and spherulite, and to improve continuous batch properties. A polyamide comprising a pamide unit is copolymerized with a specific linear aliphatic diamine and an amide unit comprising a dicarboxylic acid in an amount of 0.5 to 20 mol%, and the ratio of the carboxyl group concentration to the amino group concentration is within a specific range. Methods are known to be achieved by controlling the concentration of end groups to enter (see, for example, Patent Document 3). Examples of this document include hexamethylenediamine / adipate, a specific linear form. As an amide unit composed of an aliphatic diamine and a dicarboxylic acid, there is an example of a polyamide obtained by copolymerizing 2.9 mol% of 1,4 diaminobutane / adipic acid. It has been mounting.

  However, since the melting point of polyamide obtained by copolymerizing 2.9 mol% of 1,4 diaminobutane / adipic acid in Patent Document 3 is 4 ° C. lower than the melting point of hexamethylene adipamide homopolymer, the original N66 crimped yarn The high crimping property of this product cannot be obtained. Especially, even if it is used for saxony twisted crimped carpet, it is inferior in pinpoint property and resilience and cannot be used for high-quality carpets. It is difficult. Further, the cooling crystallization temperature was relatively high at 219 ° C., and the effect of suppressing spherulite was not sufficient due to a slight difference of 2 ° C. from 221 ° C. of the homopolymer (Comparative Example 1).

  Furthermore, with the aim of improving the thermal stability of polyamides comprising polyhexamethylene adipamide as the main constituent, suppressing gel generation and spherulite, and improving the continuous batch property, this purpose is set to 80 to 99.5. Copolyamide composed of mol% hexamethylene adipamide units and amide units composed of 0.5 to 20 mol% diamine and dicarboxylic acid containing an aromatic structure, There is known a method (for example, see Patent Document 4) which is achieved by controlling the terminal group concentration so that the ratio with the amino group concentration falls within a specific range. Examples of this document include hexamethylenediamine / Hexamethylene adipic acid / terephthalic acid is 2.9 as an amide unit composed of a dicarboxylic acid containing a diamine and an aromatic structure. Examples of Le% copolymerized polyamide are disclosed.

  However, the cooling crystallization temperature of the polyamide copolymerized with 2.9 mol% of hexamethylenediamine / terephthalic acid in Patent Document 4 is relatively high at 219 ° C., which is only 2 compared to 221 ° C. of the homopolymer (Comparative Example 1). Due to the difference in ° C., the effect of suppressing spherulite was not sufficient.

: JP-T 6-502671 (Claims) : US Pat. No. 4,919,876 (specification) : JP 2000-38444 A (Claims) : JP 2000-53762 A (Claims)

  An object of the present invention is to use a copolymerized polyamide comprising polyhexamethylene adipamide as a main component and having good crystallinity in the process of forming a fiber structure even though the formation of spherulites is small. It is to obtain a polyamide crimped yarn suitable for tufted carpet and a carpet made thereof, which is highly crimped, has a good feel when stepped on, has an excellent compression elasticity recovery rate, and is difficult to set. It is an object to obtain a polyamide crimped yarn suitable for a high-grade carpet such as a twisted crimped carpet. A further object is to produce a polyamide crimped yarn excellent in drawability and crimping processability during production, with little yarn breakage and excellent yarn production yield.

In order to solve the above-mentioned problems, according to the present invention, a polyamide composition containing a polyamide mainly composed of hexamethylene adipamide units and satisfying the following formulas (1), (2) and (3) is used. A polyamide crimped yarn having the fiber characteristics of A) to (E) is provided.
Tc (270) −Tc (300) ≧ 15 ° C. (1)
Tc (300) ≦ 188 ° C., Tc (270) ≧ 200 ° C. (2)
Tm ≧ 260 ° C. (3)

Here, Tc (T) is a cooling crystallization peak temperature measured by melting at a temperature T ° C., and Tm is a melting point.
(A) Fineness = 400 to 4000 dtex
(B) Single yarn fineness = 3 to 100 dtex
(C) Strength = 2.0 to 5.5 cN / dtex
(D) Boiling water shrinkage = 2-10%
(E) Crimp elongation = 12-22%

In the polyamide crimped yarn of the present invention,
The polyamide composition contains polyhexamethylene adipamide and a compound having a melting point of 270 to 300 ° C .;
The compound having a melting point of 270 to 300 ° C. is polyamide;
A preferable condition is that the polyamide having a melting point of 270 to 300 ° C. is polytetramethylene adipamide and / or a copolymer thereof.

  The carpet of the present invention is characterized by using the above-mentioned polyamide crimped yarn, and is particularly preferably a cut pile carpet using a saxony twisted crimped yarn.

  According to the present invention, a polyamide crimped yarn having a high crimp rate can be obtained with little generation of spherulites despite the fact that the single yarn fineness is large and it is difficult to cool. The polyamide crimped yarn of the present invention has excellent crystallinity in the fiber structure formation process even though there is little spherulite formation. It has the characteristics of being excellent in elastic recovery rate and being difficult to stick. In particular, when used as a saxony twisted crimped carpet, it is possible to obtain a high-quality carpet with good twist setting and excellent pinpoint, volume and resilience. Further, when producing crimped yarns, polyamide crimped yarns having excellent drawability and crimping processability, less yarn breakage and excellent yarn production yield can be obtained.

  The present invention is described in detail below.

  The polyamide crimped yarn of the present invention is obtained by producing a polyamide composition that mainly contains a hexamethylene adipamide unit and satisfies the following formulas (1) to (3).

Although the polyamide composition used for the polyamide crimped yarn of the present invention has a remarkable effect of suppressing spherulite, crystallization is likely to proceed in the process of forming the fiber structure. There is very little. As a result, a high crimp rate and a compression elastic recovery rate are further improved, and a carpet excellent in covering property and settling resistance is obtained. In addition, yarn breakage in the yarn making process and the crimping process is reduced, and there is an advantage that a product can be obtained with a high yield. The polyamide composition of the present invention having such effects is characterized by satisfying the following formulas (1) to (3).
Tc (270) −Tc (300) ≧ 15 ° C. (1)
Tc (300) ≦ 188 ° C., Tc (270) ≧ 200 ° C. (2)
Tm ≧ 260 ° C. (3)

  Here, Tc (T) indicates a cooling crystallization peak temperature measured by melting at a temperature T ° C., and Tm indicates a melting point. The melting point Tm was measured by using a differential scanning calorimeter and completely melting at a sample amount of 4 mg at a heating rate of 80 ° C./min, then cooling at a cooling rate of 80 ° C./min, and further at a heating rate of 80 ° C./min. The peak top temperature of the endothermic peak based on melting when the temperature is raised is defined as the melting point Tm (however, it is determined as an average value where n is 5). The crystallization temperature (Tc) is also observed when the temperature is raised to a temperature T ° C., held at the temperature T ° C. for 6 minutes, and then lowered at a rate of temperature drop of 80 ° C./min using a differential scanning calorimeter. The peak top temperature of the exothermic peak due to crystallization is defined as the crystallization temperature Tc (T) (however, it is determined as an average value where n is 5). The average value of polyhexamethylene adipamide polymerized only from hexamethylenediamine and adipic acid (hereinafter referred to as polyhexamethylene adipamide alone) measured under the above conditions is Tc (300) = 193 (each measurement The value variation is 193.0 ± 0.2) ° C., and Tm = 263 (variation of each measurement value 263.3 ± 0.2) ° C.

  In the above formula (1), the crystallization temperature Tc (300) when cooling and crystallizing after heating and melting to 300 ° C., which is a general melt spinning temperature of nylon 66, is equal to or higher than the melting point of nylon 66. However, it shows that it is lower by 15 ° C. or more than the crystallization temperature Tc (270) when it is cooled and crystallized after melting at 270 ° C., which is a relatively low temperature.

  That is, when the polyamide composition of the present invention is melted at a relatively high temperature, the cooling crystallization rate is slow, and conversely, when melted at a relatively low temperature, the crystallization rate is fast, and the polyamide composition melts at 300 ° C. In this case, the component that becomes the crystal nucleus is almost completely dissolved, whereas when it melts at 270 ° C., it means that the component that becomes the crystal nucleus remains.

  When Tc (300) is low, crystallization in the melt spinning process is difficult to proceed and the effect of suppressing spherulite is large, so that it is possible to suppress deterioration of orientation characteristics and deterioration of yarn-making property due to spherulites. On the other hand, a high Tc (270) means that crystallization is likely to proceed during the fiber structure formation process, and that the fiber structure oriented by stretching is likely to be thermally crystallized. Excellent twist setting and pinpointing properties when compressed into a yarn, resulting in a high-quality, high-quality carpet. That is, the large crystallization temperature difference between Tc (270) and Tc (300) satisfies both the spherulite suppression effect in the melt spinning process and the fiber structure heat setting effect in the stretching orientation process at the same time. This means that a high crimping rate and a compression elastic recovery rate are further improved, and a carpet excellent in covering property and sag resistance is easily obtained. This crystallization temperature difference needs to be 15 ° C. or higher, and is preferably 16 ° C. or higher. As an upper limit, it is preferable that it is 50 degrees C or less at the point that sufficient effect of the said characteristic is acquired.

  In the case of polyhexamethylene adipamide alone, the temperature difference between Tc (300) and Tc (270) is usually about 12 ° C. In addition, copolymer polyamides such as lactam, which have been conventionally known as a spherulite suppression technique, decrease both Tc (300) and Tc (270), but decrease Tc (270) more than Tc (300). Since it is large, the melting temperature dependency is small. Further, when a polyamide having a melting point of 300 ° C. such as inorganic fine particles such as talc and silica or polyhexamethylene terephthalate (hereinafter referred to as nylon 6T), which is known as a crystal nucleating agent, is added, Tc (270) Although both Tc (300) rise, since the rise of Tc (300) is larger than Tc (270), the melting temperature dependency is small as in the case of lactam copolymerization.

  The above formula (2) shows that the polyamide composition measured by melting at 300 ° C. has a cooling crystallization peak temperature Tc (300) of 188 ° C. or less and measured by melting at 270 ° C. It shows that the cooling crystallization peak temperature Tc (270) of the product is 200 ° C. or higher. That is, Tc (300) of the polyamide composition of the present invention is 5 ° C. or more lower than 193 ° C., which is Tc (300) of polyhexamethylene adipamide, and the Tc (270) of the polyamide composition is 200 ° C. or more obtained by adding 12 ° C. which is the difference in crystallization temperature between Tc (300) and Tc (270) of polyhexamethylene adipamide alone to 188 ° C. which is the maximum temperature of Tc (300) of the polyamide composition It means that.

  That is, this indicates that the polyamide composition of the present invention has a large spherulite-inhibiting effect and can simultaneously satisfy both the fiber structure heat-setting effect in the stretching orientation process, a high crimp rate, and a compression elasticity. This means that the recovery rate is further improved, and it is easy to obtain a carpet excellent in covering property and settling resistance. If the Tc (300) of the polyamide composition exceeds 188 ° C., it cannot be said that the crystallization rate was sufficiently slow, and the effect of suppressing spherulite cannot be clearly obtained. Further, when the Tc (270) of the polyamide composition is less than 200 ° C., the fiber structure heat fixation in the drawing and orientation process cannot be sufficiently performed as in the case of the conventional copolymerized polyamide polymer. Not only a certain high crimped yarn cannot be obtained, but also the inferior twist setability when producing a saxony twisted crimped yarn, and a high-quality carpet cannot be obtained. Tc (300) is preferably 186 ° C. or lower, and more preferably 180 ° C. or higher. Tc (270) is preferably 201 ° C. or higher, and more preferably 225 ° C. or lower. When Tc (300) is less than 180 ° C., crystallization during fiber structure formation does not proceed sufficiently, so that a high crimped yarn cannot be obtained, and the heat setting property when producing a saxony twisted crimped yarn is inferior. Since point property falls, it is not preferable. In addition, a polyamide composition having a Tc (270) exceeding 225 ° C has not been found, but a sufficient effect can be obtained when the Tc (270) is in the range of 200 to 225 ° C.

  Further, the above formula (3) indicates that the melting point Tm of the polyamide composition of the present invention is 260 ° C. or higher, that is, the melting point drop from the polyhexamethylene adipamide alone is within 3 ° C. . The melting point drop is preferably within 2 ° C., that is, the melting point is 261 ° C. or more. The upper limit is not particularly defined as long as melt spinning is possible under general conditions. When the melting point drop exceeds 3 ° C., that is, when the melting point Tm is 260 ° C. or less, it is difficult to obtain a highly crimped yarn. In particular, when a saxony twisted crimped yarn is used, it is difficult to obtain a high-quality carpet with poor twisted steam set property and high pinpoint property and resilience.

In the present invention, the following (A) to (E) are produced by spinning a polyamide composition having the crystallization characteristics represented by the above formulas (1) and (2) and having the melting point of the above formula (3). A polyamide crimped yarn having the following fiber characteristics is obtained.
(A) Fineness = 400 to 4000 dtex
(B) Single yarn fineness = 3 to 100 dtex
(C) Strength = 2.0 to 5.5 cN / dtex
(D) Boiling water shrinkage = 2-10%
(E) Crimp elongation = 12-22%

  The polyamide crimped yarn of the present invention needs to have a fineness of 400 to 4000 dtex, preferably 500 to 3000 dtex. Although the technology of the present invention can be applied to thick fine yarns of less than 400 dtex or more than 4000 dtex, the crimped yarn for tufted carpet which is the object of the present invention is usually used in this fineness range.

  The strength needs to be 2.0 to 5.5 cN / dtex, and preferably 2.0 to 4.0 cN / dtex. If it is less than 2.0 cN / dtex, the strength is insufficient, the pile breaks, and the durability is inferior. A strength exceeding 5.5 cN / dtex is not usually required as a crimped yarn for tufted carpet.

  The boiling water shrinkage is required to be 2 to 10%, and preferably 3 to 8%. When trying to obtain less than 2%, it is difficult to achieve the high crimp rate of the present invention. On the other hand, if it exceeds 10%, the shrinkage rate is too high, so that the volume feeling is lost and the covering property is also deteriorated.

  The crimp elongation is required to be 12 to 22%, and preferably 14 to 20%. If it is less than 12%, a good tufted carpet such as insufficient crimping, inferior elastic elasticity recovery, and easy settling cannot be obtained. On the other hand, if it exceeds 22%, crimps are excessively developed, and although the volume feeling and covering property are excellent, the carpet is not preferred because it does not have a waist and does not respond.

  Next, the polyamide composition used for the polyamide crimped yarn of the present invention is preferably a polyamide composition characterized by containing polyhexamethylene adipamide and a compound having a melting point of 270 to 300 ° C. In the case of a polyamide composition using a compound having a melting point of less than 270 ° C., the cooling crystallization peak temperature Tc (300) measured by melting at 300 ° C. is sufficiently lowered, but measured by dissolving at 270 ° C. The cooling crystallization peak temperature Tc (270) also decreases at the same time. Such a polyamide composition, like the conventional copolymer, does not sufficiently crystallize at the time of forming the fiber structure, and as a result, the high crimped yarn characteristic of the present invention cannot be obtained, and the saxony twisted crimped yarn is obtained. The carpet is inferior in twist setability when producing a high-quality carpet. On the other hand, with a polyamide composition using a compound having a melting point exceeding 300 ° C., it is difficult to obtain a stable polymer, and it is therefore difficult to produce a polyamide fiber. When a compound having a melting point of 270 ° C. or more and less than 300 ° C. is added, if it is melted at 270 ° C., the additive acts as a crystal nucleating agent, Tc (270) can be maintained high, and the compound is melted at 300 ° C. In this case, the additive acts as a crystallization inhibitor and Tc (300) is lowered.

  The amount of the compound having a melting point of 270 to 300 ° C. is preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of nylon 66 monomer which is a raw material of polyamide mainly composed of hexamethylene adipamide units. More preferably, it is 4 parts by weight. When the addition amount is less than 0.5 parts by weight, the spherulite suppression effect of the polyamide composition is not sufficient. On the other hand, if it exceeds 5 parts by weight, crystallization at the time of forming the fiber structure is difficult to proceed, the high crimped yarn that is the feature of the present invention cannot be obtained, and the twist setting property when manufacturing the saxony twisted crimped yarn is achieved. Inferior, high-quality carpet cannot be obtained.

  The above compound is not particularly limited as long as it satisfies the temperature range of 270 to 300 ° C., but is preferably similar in structure to polyhexamethylene adipamide, It is a polyamide that can be finely dispersed in it. Particularly preferred is polytetramethylene adipamide (nylon 46) and / or a copolymer thereof. In order to satisfy the characteristics of the polyamide composition of the present invention, these polymers are added in an amount of 0.5 to 5 parts by weight with respect to 100 parts by weight of nylon 66 monomer which is a raw material of polyamide comprising hexamethylene adipamide units. Is preferred. The polyamide having a melting point of 270 to 300 ° C. may be added alone, but two or more other polyamide components may be added.

  The polyamide crimped yarn of the present invention can be used for tufted carpets such as pile carpets and cut pile carpets because of its high crimpability, compression elasticity recovery, treading feeling, and durability. In particular, when used as a saxony twisted set crimped carpet, a carpet full of luxury can be obtained due to its pinpoint and tailoring properties. In addition, when a crimped yarn is produced using the polyamide composition of the present invention, it has the advantage that the product yield of the crimped yarn is good and the tufting property is also good because the yarn forming property and the crimping processability are good.

  In the following, the method for producing the polyamide crimped yarn of the present invention will be briefly described with reference to saxony twisted crimped yarn as an example.

  In the production of the polyamide composition used for the polyamide fiber of the present invention, a terminal blocking agent such as monocarboxylic acid, a matting agent such as titanium oxide, a polymerization catalyst such as a phosphorus compound, etc., as long as the effects of the present invention are not impaired. One or more lactam units other than heat-resistant agents, copper compounds and antioxidants such as halides of alkali metals or alkaline earth metals, heat stabilizers and tetramethylenediamine units and adipic acid units, which are the main constituent units A polyamide having a dicarboxylic acid unit and a diamine unit can be added at any time. The liquid phase polymerization can be produced by either a continuous polymerization method or a batch polymerization method, and then a solid phase polymerization can be performed to increase the degree of polymerization. A method for producing a polyamide fiber obtained from the polyamide composition of the present invention is shown as an example as follows.

  First, nylon, which is a raw material of polyamide comprising hexamethylene adipamide units, is added to an autoclave, an equimolar amount of 50 to 90% by weight of hexamethylenediamine and adipic acid, and a compound having a melting point of 270 to 300 ° C. of the present invention. Charge 0.5 to 5 parts by weight with respect to 100 parts by weight of 66 monomers. Nitrogen replacement was performed, and hermetic heating was performed until the internal pressure reached 1.7 to 1.8 MPa. While maintaining the internal pressure 1.7-1.8 MPa until the autoclave internal temperature reaches 250-260 ° C., the internal pressure is gradually released to atmospheric pressure over about 1-2 hours while continuing the heating, During this time, the internal temperature is raised to 280-290 ° C. Then, after reducing the pressure in the autoclave and proceeding the polymerization, the pressure is increased, and the polymer is extruded into a strand having a diameter of about 2 to 4 mm and cut to about 3 to 5 mm to obtain a polymer chip. The relative viscosity of the polymer chip is preferably 2.5 to 3.0.

  Next, the polymer chip is dried by a batch type drying apparatus or a tower type continuous drying apparatus. The dried polymer chip is conditioned to a moisture content of 0.07 to 0.10 and then supplied to the yarn making hopper.

  The polyamide crimped yarn of the present invention can be obtained through a normal crimped yarn production process comprising the copolymerized polyamide, which includes the steps of known melt spinning, cooling, oiling, drawing, and crimping. The melt spinning apparatus used in the present invention can be used in both an extruder-type spinning machine and a pressure melter-type spinning machine, but an extruder-type spinning machine is preferable in terms of product uniformity, yarn production yield, etc. Is particularly advantageous when blend spinning. The colorant may be either organic or inorganic, but generally, carbon black, bengara, and phthalocyanine pigments are preferably used, and can be appropriately used depending on the required hue. The addition ratio of the colorant to the crimped yarn is not particularly limited and may be set as appropriate, but is usually preferably 0.01 to 3.0% with respect to the entire components constituting the crimped yarn.

  The cross-section of the polyamide crimped yarn of the present invention is an irregular cross-section, and can be Y-shaped, field-shaped, flat, hollow, and other various shapes. In particular, the cross-sectional shape suitable for the polyamide crimped yarn of the present invention is Y-type, Y-type hollow, paddy-shaped, flat, flat hollow, and the like. In order to obtain a crimped yarn having such a cross-sectional shape, spinning conditions such as the molecular weight of the polymer, the spinning temperature, the die hole shape, the discharge amount, and the cooling are appropriately set. The degree of deformation in the Y-type or Y-type hollow cross-sectional shape is preferably 1.5 to 6.0. 2.0-5.0 is more preferable. The degree of deformation referred to here is expressed by the ratio (D / d) of the diameter D of the circumscribed circle of the single yarn cross section and the diameter d of the inscribed circle of the single yarn cross section, and the degree of deformation is less than 1.5. If it exists, the space | gap between single yarns will decrease in a multifilament, and the bulkiness and feel of a carpet will fall. Further, when the degree of deformation exceeds 6.0, the yarn-making property may be deteriorated, and the quality such as single yarn breakage and tarmi may be deteriorated. In the case of a hollow cross section, the hollowness is preferably 5 to 30%, more preferably 10 to 20%. If the hollowness is less than 5%, the bulkiness and texture of the carpet are lowered. When the hollow ratio exceeds 30%, the yarn-making property may be deteriorated, and the quality such as single yarn breakage and tarmi may be deteriorated. Further, the number of hollow portions is not limited, and may be one or plural, such as a cross section. The melt-spun yarn is cooled and solidified by cold air, and after applying an oil, it is wound around a take-up roll that rotates at a predetermined take-up speed. The take-up speed is preferably 300 to 1000 m / min. The drawn yarn is usually continuously stretched and crimped continuously. As another method, a method of once winding with undrawn yarn and then drawing and crimping in another step, or a method of once winding drawn yarn and then crimping in another step is also possible. .

  The polyamide crimped yarn of the present invention has a high crimp elongation, and for that purpose, it is necessary to raise the molecular chain orientation sufficiently in the drawing step before crimping. The stretching ratio is preferably in the range of 2.0 to 4.0 times, and the stretching is preferably performed so that the elongation becomes 30 to 80%.

  Next, the drawn yarn is subjected to a crimping process through a crimping device. Crimping is performed using a heated fluid. The polyamide crimped yarn of the present invention is usually crimped by a jet nozzle system having the crimped nozzle, and a high-temperature fluid of 250 to 280 ° C. such as heated steam is brought into contact with the yarn passing through the needle from the surroundings. It is crimped by releasing into the atmosphere and cooling. Furthermore, for the purpose of fixing the crimp, a method of blowing cold air to the crimped yarn that has passed through the crimp nozzle, or depositing the crimped yarn on the surface of the rotary filter that sucks into the inside and cooling it is also adopted. The

  An appropriate stretch is given to the crimped yarn that has been crimped to make a portion of the crimp latent, and then wound by a winder. The crimped yarn is usually subjected to an entanglement process in order to impart convergence before winding.

  The crimped yarn obtained by the above method is tufted as it is or mixed with two or three differently colored crimped yarns to obtain a tufted carpet.

  In the case of saxony twisted crimped yarn, it is used after twisted. The twisted yarn is twisted in one piece, and then twisted in two or three opposite directions to form various twists. The number of twists is 100 to 290 t / m, preferably 150 to 260 t / m.

  The above-mentioned various twisted crimped yarns are treated with a steam setter and fixed by twisting to obtain saxony twisted crimped yarns. The saxony twisted crimped yarn is tufted into a cut pile carpet. The steam setter is performed using, for example, a Superba set machine manufactured by Superba. Usually, heat treatment is performed using saturated or superheated steam at 120 to 270 ° C. for 30 seconds to 3 minutes, preferably 50 seconds to 2 minutes.

Tufting can be performed by a known ordinary method, but the stitch, gauge, pile height, etc. are determined in consideration of the fineness and crimping characteristics of the saxony twisted crimped yarn. For example, the tuft standard for expressing a high-class feeling is, for example, basis weight: 600 to 900 g / m ² , stitch: 10 to 20 pieces / inch, gauge: 1/8 to 1/15 G, pile length = 5 to 12 mm, Is preferred.

  The tufted cut pile carpet is dyed and backed by a known method. Dyeing can be continuous dyeing, Wins dyeing, rope dyeing, or the like. Of course, the carpet using the original crimped yarn or the cheese dyed yarn can be backed without being dyed.

  Next, raising treatment or water jet punching treatment may be performed for the purpose of producing a sense of volume by slightly disturbing the convergence of the saxony twisted crimped yarn. These processes may be performed continuously in the backing process or in a separate process. While moving the tuft fabric at a constant speed, a needle or high-pressure water stream is mechanically collided with the cut pile surface, and the single yarn of the surface layer portion of the saxony twisted crimped yarn is separated.

  Thus, the saxony twisted crimped yarn of the present invention and a cut pile carpet using the same are obtained. The polyamide crimped yarn of the present invention has the characteristics specified in the present invention, and a saxony twisted crimped yarn and a cut pile carpet using the polyamide crimped yarn have a volume feeling, a point feeling, a resilience, a high-class feeling, etc. It is an excellent carpet, and is particularly suitable as a high-grade roll carpet or a line mat for a high-end vehicle.

Hereinafter, the present invention will be specifically described by way of examples. Definitions of characteristic values and measurement methods described in the specification text and examples are as follows.

  (1) Relative viscosity: 0.25 g of a sample was dissolved in 25 ml of 98% sulfuric acid and measured at 25 ° C. using an Ostwald viscometer. The relative viscosity was determined from the ratio of the number of seconds that the polymer solution and sulfuric acid dropped.

  (2) Moisture content: Measured using a Karl Fischer measuring device (vaporizer: SE-24 type, electrolytic cell: AQ-6 type) manufactured by Hiranuma Sangyo Co., Ltd. The sample was 3 g, and the nitrogen used for water vaporization was 220 ° C. and 200 ml / min.

  (3) Melting point (Tm): Measured using a differential scanning calorimeter of Diamond DSC manufactured by Perkin-Elmer. The sample was measured at 4 mg and the heating rate was 80 ° C./min, and the peak temperature of the melting endothermic curve was taken as the melting point.

  (4) Crystallization temperature (Tc): Measured using a DSC-7 type differential scanning calorimeter manufactured by Perkin-Elmer. The sample amount was 4 mg, the temperature was raised to T ° C. at a temperature rising rate of 80 ° C./min, held at the temperature T ° C. for 6 minutes, and then cooled at a temperature lowering rate of 80 ° C./min. (T).

  (5) Total fineness: JIS L1013 (2010) 8.3.1 b) The positive fineness was measured by the B method to obtain the total fineness.

  (6) Single yarn fineness: Determined by dividing the fineness by the number of filaments.

  (7) Strength / Elongation: Measured under constant speed elongation conditions shown in JIS L1013 (2010) 8.5.1 standard time test. The sample was “TENSILON” UCT-100 manufactured by Orientec Co., Ltd., and the gripping interval was 25 cm and the pulling speed was 30 cm / min. In addition, elongation was calculated | required from elongation of the point which showed the maximum strength in a SS curve.

  (8) Boiling water shrinkage ratio: JIS L1013 (2010) 8.18.1 b) Measured according to filament dimensional change rate (Method B).

  (9) Degree of deformation: A single yarn cross section of the sample was cut out and observed at 500 times using a digital microscope “VHX-500” manufactured by KEYENCE, and the diameter D of the circumscribed circle of the convex portion of the single yarn fiber cross section was It calculated | required from ratio (D / d) of the diameter d of the inscribed circle of the recessed part of a thread | yarn cross section, and computed from the average value of 10 samples.

  (10) Degree of spherulite formation: An undrawn yarn filament was used as a sample, embedded in paraffin to obtain a section, and this section was dropped on a slide glass by adding xylene dropwise to dissolve and remove the paraffin. . The sample was observed with a polarizing microscope at 200 times, and the image was printed to determine the area (%) of spherulites in the cross section.

(11) Crimp elongation: The skeined yarn is allowed to stand for 3 hours in a room at 20 ° C. and 65% RH to release it. Next, it is immersed in boiling water for 20 minutes to perform boiling water treatment. The skeined yarn treated with the rising water is left to dry in the aforementioned room for 12 hours. Next, the yarn was cut to a length of about 1 m, and when the total fineness of the yarn was A (dtex), an initial load of 17.7 A (μN) (1.8 A (mg)) was applied for 30 seconds. First, the yarn length L1 is measured. Next, the length L2 of the yarn after applying a constant load of 883A (μN) (90A (mg)) for 30 seconds is measured. The crimp elongation rate G (%) in the present invention is determined from the following formula using L1 and L2.
G = ((L2−L1) / L1) × 100 (%)

(12) Carpet evaluation (1) Sensory evaluation: Waist, point feeling, color tone (dyeability) and appearance by appearance evaluation were evaluated in four stages as follows.
◎: Level substantially superior to conventional N66BCF Saki Sony ○: Level slightly superior to conventional N66BCF Saki Sony △: Level equivalent to conventional N66BCF Saki Sony ×: Level inferior to conventional N66BCF Saki Sony

(13) Carpet evaluation (2) Practical evaluation: Crimp sag durability was measured using a circular pressurizer having an area of 1000 mm ² according to the method of JIS L1021-6 (2007) 3.2, and the above (12 Evaluation was made in four stages.

  (14) Thread breakage frequency: The number of yarn breaks per 1 ton of production was obtained, and the yarn breakage frequency was indicated by times / t.

[Example 1]
Autoclave 6 m ^3, triturated with 90 wt% aqueous solution of 3000kg and advance mixer is a salt of hexamethylene diamine and adipic acid hexamethylene diammonium adipate (AH salt), 36 passes through the mesh, the powder to stay 100 mesh Nylon 46 (manufactured by Aldrich Chemical Co., Ltd., melting point: 293 ° C.) was charged in the amount shown in Table 1, and liquid phase polymerization was performed.

  The liquid phase polymerization conditions were as follows. The autoclave was heated at 300 ° C. in a closed system, and when the internal pressure rose to 1.7 MPa (internal temperature 210 ° C.), the pressure was controlled by opening the valve on the top of the autoclave so as to maintain the pressure. . When the internal temperature reached 245 ° C., the internal pressure was gradually released to 0.1 MPa in 1 hour. Further, the pressure in the system was reduced to 0.05 MPa using a vacuum pump and maintained for 15 minutes to complete the polymerization. Next, the polyamide obtained by polymerization was extruded into cold water in the form of a strand having a diameter of about 3 mm and cut to a length of about 3 mm to obtain a polymer chip. The relative viscosity of the obtained polymer chip was 2.81.

  Next, the obtained polyamide composition was dried at 105 ° C. using a batch type drying apparatus to obtain dry chips. The dried polymer chip was conditioned to a moisture content of 0.10% and then supplied to a yarn hopper.

  Melt spinning was performed using a 45φ extruder-type spinning machine. Using a die having a spinning temperature of 300 ° C. and a Y-shaped hole (slit length / slit width = 4.5), yarn was produced so that the total fineness of crimped yarn was 1360 dtex, the number of filaments was 136, and the single yarn fineness was 10 dtex. The film was drawn hot at a take-up speed of 800 m / min, a draw ratio of 2.2 times, and a drawing temperature of 230 ° C. Next, the drawn yarn was continuously crimped by a crimping nozzle at 270 ° C., stretched by applying 0.12 cN / dtex, and after latentizing the crimping, about 15 pieces / m were passed through the entanglement nozzle. Wound up with confounding. In addition, the undrawn yarn used for the evaluation of the degree of spherulite formation was sampled with a small amount of squeezing on a take-up roll.

  Next, the crimped yarn obtained above was formed into a twisted crimped yarn by applying a twist of 240 t / m in the Z direction and 240 t / m from the top in the Z direction by a Beldoll type twisting machine. Furthermore, the twisted crimped yarn was processed for 1 minute at 150 ° C. with a spell bar type steam processing machine to obtain the saxony twisted crimped yarn of the present invention.

  The obtained saxony twisted crimped yarn was tufted according to the following tuft standard to obtain a cut pile carpet.

Weight per unit area: 700 g / m ² , gauge: 1/10 G, pile height: 8 mm, number of stitches: 16 pieces / inch, pile: cut pile The above cut pile is subjected to wins dyeing at 98 ° C. × 60 minutes and dried. The cut pile carpet of the present invention was obtained.

  Table 1 shows the properties of the polyamide composition, polyamide crimped yarn and cut pile carpet obtained by the above polymerization, yarn production and higher processing conditions.

[Example 2]
A polyamide composition was obtained in the same manner as in Example 1 except that the addition amount of nylon 46 was changed as shown in Table 1. The relative viscosity of the polymer chip was 2.83. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. Table 1 shows properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet.

[Example 3]
A polyamide composition was obtained in the same manner as in Example 1 except that the addition amount of nylon 46 was changed as shown in Table 1. The relative viscosity of the polymer chip was 2.84. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. Table 1 shows properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet.

[Example 4]
Instead of nylon 46, the copolymer of nylon 46 / nylon 66 shown in Table 1 (molar ratio: nylon 46/66 = 95/5, melting point Tm = 288 ° C., tetramethylene adipamide (nylon 46 component) and A polyamide composition was obtained in the same manner as in Example 1 except that a copolymer of hexamethylene adipamide (nylon 66 component) (hereinafter, “/” means copolymerization) was used. The relative viscosity of the polymer chip was 2.81. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. Table 1 shows properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet.

[Example 5]
A polyamide composition was obtained in the same manner as in Example 1 except that a nylon 46 / nylon 66 copolymer shown in Table 1 was used instead of nylon 46. The relative viscosity of the polymer chip was 2.82. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. Table 1 shows properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet.

[Comparative Example 1]
A polyamide composition was obtained in the same manner as in Example 1 except that nylon 46 was not added. The relative viscosity of the polymer chip was 2.83. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. The properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet are shown in Table 2.

[Comparative Example 2]
A polyamide composition was obtained in the same manner as in Example 1 except that the addition amount of nylon 46 was changed as shown in Table 2. The relative viscosity of the polymer chip was 2.80. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. The properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet are shown in Table 2.

[Comparative Example 3]
A polyamide composition was obtained in the same manner as in Example 4 except that 8 parts by weight of a nylon 46 / nylon 66 copolymer was used. The relative viscosity of the polymer chip was 2.82. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. The properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet are shown in Table 2.

[Comparative Example 4]
A polyamide composition was obtained in the same manner as in Example 3 except that nylon 6 shown in Table 1 (“CM1010” melting point Tm = 220 ° C., manufactured by Toray Industries, Inc.) was used instead of nylon 46. The relative viscosity of the polymer chip was 2.81. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. The properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet are shown in Table 2.

[Comparative Example 5]
A polyamide composition was obtained in the same manner as in Example 1 except that nylon 6T shown in Table 1 (“AE4200” melting point Tm = 320 ° C., manufactured by Aalen) was used instead of nylon 46. The relative viscosity of the polymer chip was 2.83. Further, melt spinning of the polyamide composition obtained in the same manner as in Example 1 was performed. The properties of the obtained polyamide composition, polyamide crimped yarn and cut pile carpet are shown in Table 2.

  Examples 1 to 5 and Comparative Examples 1 to 5 are evaluations of saxony twist set crimped carpets. From the results of Table 1, all the examples satisfy the polymer characteristics and crimped yarn characteristics of the present invention, and have the characteristics that the stepping feeling important as a saxony twist set crimped carpet is good and difficult to stick. You can see that you are fully satisfied. On the other hand, none of the comparative examples satisfy either of the polymer characteristics of the polyamide composition of the present invention, so that the crimped yarn characteristics and the saxony twist set crimped carpet characteristics are inferior.

  The polyamide crimped yarn of the present invention has a high single yarn fineness and is difficult to cool, so that the formation of spherulites is small and the crimp rate is high, so when used as a tufted carpet, the tread feel is good. , It has the characteristics that it is excellent in the compression elastic recovery rate and difficult to stick. In particular, it is suitable for high-grade carpets such as saxony twisted crimped carpets. Further, it is possible to obtain a polyamide crimped yarn which is excellent in drawability and crimp processability during production, has few yarn breaks and has an excellent yarn production yield.

Claims (6)

It contains a polyamide mainly composed of hexamethylene adipamide units, is composed of a polyamide composition satisfying the following formulas (1), (2) and (3), and has the following fiber characteristics (A) to (E). Polyamide crimped yarn characterized by
Tc (270) −Tc (300) ≧ 15 ° C. (1)
Tc (300) ≦ 188 ° C., Tc (270) ≧ 200 ° C. (2)
Tm ≧ 260 ° C. (3)
Here, Tc (T) is a cooling crystallization peak temperature measured by melting at a temperature T ° C., and Tm is a melting point.
(A) Fineness = 400 to 4000 dtex
(B) Single yarn fineness = 3 to 100 dtex
(C) Strength = 2.0 to 5.5 cN / dtex
(D) Boiling water shrinkage = 2-10%
(E) Crimp elongation = 12-22% The polyamide crimped yarn according to claim 1, wherein the polyamide composition contains polyhexamethylene adipamide and a compound having a melting point of 270 to 300 ° C. The polyamide crimped yarn according to claim 2, wherein the compound having a melting point of 270 to 300 ° C is polyamide. The polyamide crimped yarn according to claim 2 or 3, wherein the polyamide having a melting point of 270 to 300 ° C is polytetramethylene adipamide and / or a copolymer thereof. A carpet comprising the polyamide crimped yarn according to any one of claims 1 to 4. The carpet according to claim 5, wherein the carpet is a cut pile carpet using saxony twisted crimped yarn.