JP4838691B2 - Monofilament and fishing line - Google Patents

Description

  The present invention relates to a monofilament made of a polyamide-based resin and a fishing line using the same.

  Conventionally, as a fishing line using a polyamide-based resin, one made of nylon 6/66 monofilament obtained by copolymerizing nylon 6 with a small amount of nylon 66 has been widely used. Such monofilaments are known to have properties suitable for fishing lines, such as excellent strength and flexibility, and being difficult to curl.

  However, such a monofilament has a higher specific gravity than water, so that it easily sinks and is not suitable for a fishing technique that floats a fishing line on water. For example, as a fishing technique, `` Fukase fishing '' that floats the road line and sinks a light mechanism naturally is used frequently in carp fishing etc., but the monofilament mentioned above has a large specific gravity, so this It was not suitable for such a method. In addition, the monofilament using nylon 6/66 has a high water absorption, so that it has a problem that it absorbs water during fishing and is more likely to sink. For this reason, monofilaments made of polyamide-based resin are desired to have a lower specific gravity while maintaining the above-mentioned preferable characteristics.

The following is known as a monofilament made of a polyamide resin and having a specific gravity lower than that of the conventional one. That is, firstly, one using a polyamide resin with a low specific gravity (see Patent Document 1) or one made of a polyamide resin blended with a low specific gravity polyamide resin (see Patent Documents 2 and 3) is known. . Also known are composite monofilaments (see Patent Document 4) in which a conventional polyamide resin and a low specific gravity polyamide resin are combined as a core material and a sheath material, respectively, and monofilaments having a hollow structure (see Patent Documents 5 and 6). It has been.
JP 2002-129431 A Japanese Patent No. 2622837 JP 2005-237228 A Japanese Patent Publication No. 6-12970 JP 55-159743 A JP 2001-161237 A

  However, as a result of investigations by the present inventors, it has been confirmed that the conventional monofilaments having a reduced specific gravity have the following disadvantages when applied to fishing lines. That is, first, conventionally, nylon 6/12 is known as a low specific gravity polyamide resin, and it is also frequently used for fishing lines, but this is sufficiently low specific gravity for the above-mentioned uses. It wasn't. Further, nylon 11 and nylon 12 having lower specific gravity are known, but these have low strength and are difficult to apply as fishing lines. In particular, it is important for fishing lines to have a characteristic that is difficult to break when a knot is formed, i.e., a high knot strength, but monofilaments made of a polyamide resin having a low specific gravity as described above have a particularly high knot strength. There was an inadequate trend.

  In addition, when blending a low specific gravity polyamide resin with conventional nylon 6/66 or the like, the blending amount of the low specific gravity polyamide resin is increased (for example, 10% or more) in order to sufficiently reduce the specific gravity. There is a problem that spinning becomes unstable and a good monofilament cannot be obtained. For this reason, it has been difficult to obtain a monofilament having a sufficiently low specific gravity by such a blending method.

  Furthermore, composite monofilaments whose surfaces are covered with a low specific gravity polyamide resin as a sheath material and monofilaments having a hollow structure can be sufficiently reduced in specific gravity, but the resulting monofilament has extremely low knot strength. It was confirmed.

  As described above, monofilaments made of a polyamide resin having a low specific gravity by a conventional method tend to be difficult to sufficiently satisfy both characteristics of a low specific gravity and a high knot strength. It has been found that the fishing line used in fishing techniques is not necessarily suitable.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a monofilament made of a polyamide-based resin that can satisfy both characteristics of low specific gravity and high knot strength. Another object of the present invention is to provide a fishing line using such a monofilament.

In order to achieve the above object, the monofilament of the present invention is a core / sheath composite monofilament having a core material extending in the axial direction and a sheath material covering the core material, each of the core material and the sheath material being polyamide. When the number of amide groups per 100 atoms constituting the main chain of the polyamide resin is defined as the amide group concentration, the amide group concentration of the polyamide resin constituting the core material is rather smaller than the amide group concentration of the polyamide resin constituting the sheath material, polyamide-based resin constituting the core material, nylon 12, or a nylon 6/12 amide group concentration is 12 or less, the sheath material The polyamide-based resin to be formed is nylon 6, nylon 66, nylon 6/66, or nylon 6/12 having an amide group concentration higher than 12 .

  Here, the “amide group concentration” of the polyamide-based resin is the number of amide groups per 100 atoms constituting the main chain of the polyamide-based resin. The number of atoms constituting the main chain includes carbon atoms and nitrogen atoms constituting the amide group. Specifically, in the case of a homopolymer composed of only a single repeating unit, the “amide group concentration” is the number of amide groups in the repeating unit and the number of atoms constituting the main chain of the repeating unit. It can be made into the value obtained by dividing by the number of and converting this into the number per 100 atoms of the main chain. In the case of a copolymer composed of a plurality of repeating units, the amide group concentration for each repeating unit is calculated, and the value obtained by adding the values obtained by multiplying the respective copolymerization ratios by these values can do.

  The polyamide resin tends to have a lower specific gravity as the amide group concentration is lower. Therefore, the monofilament of the present invention can be reduced in specific gravity by using a core material made of a polyamide resin having a low amide group concentration. However, as described above, in the past, sufficient knot strength was obtained even when only a low specific gravity polyamide-based resin was used or a composite structure using a low specific gravity polyamide-based resin only for a sheath material. There was a tendency not to be obtained. In contrast, the present inventors have a case where a core material having a low specific gravity and a low knot strength is provided by arranging a sheath material made of a polyamide resin having a higher amide group concentration outside the core material. However, it has been found that the knot strength of the entire monofilament can be improved. In other words, the monofilament of the present invention can be reduced in specific gravity by covering the core material with a sheath material, and the core material is composed of a polyamide-based resin having a lower amide group concentration than the sheath material, and is sufficient. It is now possible to maintain a high nodule strength.

  Here, the knot strength of the monofilament indicates resistance to breakage of the knot portion (knot). Usually, when a knot is provided on a monofilament and both sides thereof are pulled, a compression / shearing force acts on the knot portion together with a pulling force. Therefore, in order to increase the knot strength, it is necessary to have not only a resistance force against a pulling force but also a resistance force against compression / shear. It is considered that the polyamide-based resin has a high bonding strength between structural units of the molecular chain due to hydrogen bonding between the amide groups and the like due to a hydrogen bond between the amide groups, thereby increasing resistance to compression / shearing force. And according to the knowledge of the present inventors, the monofilament can maintain a high resistance as a whole when at least its surface layer portion has a high resistance to the compression / shearing force. Guessed. Therefore, it is considered that the monofilament of the present invention can maintain excellent knot strength as a whole by providing a sheath material having a higher amide group concentration. However, the factor of the effect obtained by the present invention is not necessarily limited to this.

  In the monofilament of the present invention, the amide group concentration of the sheath material is preferably 13 or more. When the amide group concentration of the sheath material is 13 or more, the resistance of the sheath material to the compression / shear force is particularly strong, and the knot strength of the monofilament is further increased.

  The amide group concentration of the core material is preferably 12 or less. A core material having such an amide group concentration has a sufficiently low specific gravity, and a monofilament having a lower specific gravity and a higher knot strength can be obtained by combining with a sheath material having a higher amide group concentration.

In other words, the monofilament of the present invention is a core / sheath composite monofilament having a core material extending in the axial direction and a sheath material covering the core material, each of the core material and the sheath material being polyamide-based. is composed of a resin, the specific gravity of the polyamide resin constituting the core material, rather smaller than the specific gravity of the polyamide resin constituting the sheath material, polyamide-based resin constituting the core material, nylon 12, or, amide Nylon 6/12 having a base concentration of 12 or less, and the polyamide resin constituting the sheath material is nylon 6, nylon 66, nylon 6/66, or nylon 6/12 having an amide group concentration higher than 12. it may be characterized in that there.

  Such a monofilament of the present invention has a configuration in which the core material made of a polyamide resin having a lower specific gravity is covered with a sheath material made of a polyamide resin having a higher specific gravity, so that the specific gravity is reduced as a whole and is excellent. Have nodule strength.

  More specifically, in the monofilament of the present invention, the polyamide resin constituting the core material is nylon 11, nylon 12, or nylon 6/12 having an amide group concentration of 12 or less, and the sheath material is The polyamide-based resin to be formed is preferably nylon 6/66 or nylon 6/12 having an amide group concentration of more than 12. By doing so, the amide group concentration and specific gravity of the core material and the sheath material are each in a suitable range, and a monofilament having a sufficiently low specific gravity and an excellent knot strength can be obtained.

  The present invention also provides a fishing line comprising the monofilament of the present invention. Since such a fishing line is made of the monofilament of the present invention, it has a low specific gravity and a high knot strength. Therefore, the present invention is suitable for use in fishing methods such as “Fake fishing” as described above and “Top water fishing” using a lure that floats on the water surface.

  According to the present invention, it is possible to provide a monofilament made of a polyamide-based resin that has a low specific gravity so that it does not immediately sink in water and has sufficient knot strength. Further, it is possible to provide a fishing line that is made of such a monofilament and is suitable for a fishing technique that floats the fishing line on water.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a structure near the end of a monofilament according to a preferred embodiment. A monofilament 1 shown in FIG. 1 has a core material 2 extending in a certain axial direction and a sheath material 3 covering the core material. The sheath material 3 is formed on the outer peripheral surface parallel to the length direction of the core material 2 and is disposed on the outermost surface of the monofilament 1. In this monofilament 1, both the core material 2 and the sheath material 3 are mainly composed of a polyamide-based resin. The amide group concentration of the polyamide resin constituting the core material 2 is smaller than the amide group concentration of the polyamide resin constituting the sheath material 3.

  As the polyamide-based resin constituting the core material 2 and the sheath material 3, aliphatic polyamide (nylon) is suitable. Polyamide resins include aliphatic polyamides (l-type nylon; nylon 6, nylon 11, nylon 12, etc.) obtained by self-polycondensation of ω-amino acids and ring-opening polymerization of lactam, and polycondensation of diamine and dicarboxylic acid. Examples thereof include aliphatic polyamides (mn type nylon; nylon 66, nylon 610, nylon 612, etc.) and aliphatic polyamides (copolymerized nylon; nylon 6/12, nylon 6/66, etc.) copolymerized with these.

  The polyamide-based resin constituting the core material 2 and the sheath material 3 is selected so as to be a combination satisfying the relationship of the amide group concentration between the core material 2 and the sheath material 3 as described above. Here, the amide group concentration of the polyamide-based resin is the number of amide groups (—CONH—) per 100 atoms constituting the polyamide-based main chain as described above. The main chain means the longest chain constituting the polyamide resin. The polyamide-based resin may have a structural unit other than the main repeating unit. In this case, the number of amide groups and the number of main chain atoms in the structural unit are not considered. Therefore, the amide group concentration may be a value obtained based on the number of main chain atoms and the number of amide groups per repeating unit constituting the polyamide-based resin.

  For example, in the case of nylon 6 which is l-type nylon, the number of atoms of the main chain per one repeating unit is 7 pieces of carbon (C) + nitrogen (N). The number of amide groups per repeating unit is one. Since the amide group concentration is obtained by converting the amide group concentration in one repeating unit per 100 atoms of the main chain, (1 (number of amide groups) / 7 (number of main chain atoms)) X100 = 14.3.

  In the case of nylon 66, which is an mn-type nylon, the number of atoms in the main chain per repeating unit is 6 for C derived from hexamethylenediamine, 2 for N, and 6 for C derived from adipic acid. 14 in total. Further, the number of amide groups per repeating unit is two. Therefore, the amide group concentration is (2 (number of amide groups) / 14 (number of atoms in the main chain)) × 100 = 14.3.

  Further, in the case of nylon 6/12, which is a copolymer nylon, the amide group concentration of nylon 6 is 14.3, and the amide group concentration of nylon 12 is 7.7. Therefore, for example, if the copolymerization ratio is nylon 6 / nylon 12 = 80/20, the total amide group concentration is 14.3 × 0.8 + 7.7 × 0.2 = 13.0.

  In the monofilament 1, the polyamide-based resin constituting the sheath material 3 preferably has an amide group concentration higher than 12, more preferably 13 or higher. By having the sheath material 3 made of such a polyamide-based resin, the knot strength of the monofilament 1 becomes more excellent.

  Moreover, the amide group concentration of the polyamide-based resin constituting the core material 2 is preferably 12 or less, more preferably 9 or less, and even more preferably 8.3 or less. If it carries out like this, even if it is a case where it combines with the sheath material 3, a sufficiently low specific gravity monofilament will come to be obtained.

  The polyamide resin constituting the core material 2 has a specific gravity smaller than that of the polyamide resin constituting the sheath material 3 in order to reduce the specific gravity of the monofilament 1. The specific gravity of the polyamide resin constituting the core material 2 is preferably 1.10 or less, and more preferably 1.05 or less. When the core material 2 is composed of such a polyamide-based resin, the specific gravity is low enough that the monofilament 1 does not sink into water immediately.

  Specific examples of the polyamide resins for constituting the core material 2 and the sheath material 3 that satisfy the above-described conditions include the following. That is, as the polyamide-based resin constituting the core material 2, nylon 11, nylon 12, nylon 610, nylon 612, or nylon 6/12 having an amide group concentration equal to or lower than the above-described preferred value is preferable. Examples of the nylon 6/12 include those having a copolymerization ratio of nylon 12 of 40% or more. Moreover, as a polyamide-type resin which comprises the sheath material 3, nylon 6/12 which has the amide group density | concentration more than the suitable value mentioned above is preferable for nylon 6, nylon 6/66. Examples of the nylon 6/12 include those having a copolymerization ratio of nylon 12 of less than 40%.

  The monofilament 1 has a core / sheath composite structure as described above, but the ratio of the core material 2 to the sheath material 3 (core material 2 / sheath material 3) in the structure is 90/10 to 10 in weight ratio. 10/90 is preferable, and 80/20 to 20/80 is more preferable. By satisfying such a core-sheath ratio, the monofilament 1 is satisfactorily reduced in specific gravity and has sufficient knot strength.

  The monofilament 1 preferably has an overall specific gravity of 1.02 or more and less than 1.10, and preferably has a knot strength of 600 MPa or more, more preferably 700 MPa or more. The monofilament 1 satisfying these conditions has a sufficiently small specific gravity, so that it is difficult to sink in water, and it has a high knot strength, so that it is suitable as a fishing line.

  Furthermore, the monofilament 1 preferably has a tensile modulus of 4.0 GPa or less, and more preferably 3.5 GPa or less. As a result, the monofilament 1 is flexible and difficult to be wound, and even if it has a hook, it can be easily removed. It will be more suitable as the required road thread.

  In addition, although the core material 2 and the sheath material 3 in the monofilament 1 are mainly composed of a polyamide resin, they may contain components other than the polyamide resin. Examples of such other components include plasticizers, heat stabilizers, lubricants, antioxidants, light-resistant agents such as UV absorbers and light stabilizers, water repellents, fluorescent whitening agents, colorants, inorganic fillers, and the like. Can be mentioned. These may be contained in a total amount of about 0.001 to 10% by weight with respect to the polyamide-based resin. Moreover, these other components may be contained in both the core material 2 and the sheath material 3, and may be contained only in any one.

  The monofilament 1 having the above-described structure can be manufactured, for example, by the following manufacturing method. That is, first, polyamide resins for forming the core material 2 and the sheath material 3 are charged into separate extruders. Next, these polyamide resins are melted at 200 to 260 ° C. Then, the melted polyamide resins are simultaneously extruded using a core / sheath type composite nozzle so that the polyamide resin for forming the sheath material 3 covers the periphery of the polyamide resin for forming the core material 2. Thus, core / sheath composite spinning is performed.

  In such spinning, the polyamide-based resin extruded from the nozzle is once put into water or the like and rapidly cooled, and then stretched while being heated again with hot water or hot air to obtain a monofilament 1 having a desired diameter. be able to. In this case, stretching may be repeated. The ratio between the core material 2 and the sheath material 3 in the monofilament 1 can be adjusted by appropriately setting the extrusion amount of each polyamide resin during extrusion.

  As described above, the monofilament 1 can be obtained satisfactorily, but the manufacturing method is not limited to the above method. For example, after the core material 2 is formed first, this is made of a polyamide-based resin for forming the sheath material 3. You may make it coat | cover.

  According to the monofilament 1 having the above-described configuration, a low specific gravity can be achieved as a whole by using a polyamide resin having a low amide group concentration and a low specific gravity for the core material 2. Conventionally, the core material 2 with low specific gravity has never been high in knot strength per se, but the monofilament 1 has such a core material 2, but the surface of the core material 2 is not provided. Is covered with a sheath material 3 made of a polyamide-based resin having a higher amide group concentration than the above, thereby having a good knot strength as a whole. As described above, the monofilament 1 can have a low specific gravity and a sufficient knot strength.

  And since such monofilament 1 has low specific gravity and high knot strength, it is suitable as a fishing line used for a fishing technique or the like that is required to float on water. Such a fishing line may be composed only of the monofilament 1 described above, or may be appropriately combined with another fishing line or the like.

  The monofilament of the present invention is not necessarily limited to that of the above-described embodiment, and the configuration may be appropriately changed without departing from the gist of the present invention. For example, in the above-described embodiment, the monofilament 1 in which the sheath material 3 is provided directly on the surface of the core material 2 is illustrated. However, the present invention is not limited thereto, and the core material 2 is provided at the center portion and the sheath material is formed on the outermost surface. If it is the structure which has 3, the other layer may be provided between the core material 2 and the sheath material 3. FIG.

EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to these Examples.
[Material of monofilament]

［モノフィラメントの製造：実施例１〜１９］ As materials for monofilaments of the following examples and comparative examples, polyamide resins (nylon), vinylidene fluoride resins and plasticizers shown in Table 1 below were appropriately selected and used. In the table, “Ny” represents “nylon” (the same applies hereinafter). Moreover, when the polyamide-based resin is copolymerized nylon, the copolymerization ratio is also shown.

[Production of Monofilament: Examples 1 to 19]

  The production of the monofilaments of Examples 1 to 19 was performed according to the following method. That is, first, a sheath material and a core material were prepared as monofilament materials. Each of these resins is separately fed into two extruders, melted at a predetermined extrusion temperature, and then a core / sheath type composite nozzle is used, so that each sheath material: core material has a predetermined weight ratio. A core / sheath composite spinning was carried out by setting the extrusion amount.

  The resin discharged from the nozzle is rapidly cooled in water at a cooling temperature of 5 ° C., then passed through hot water and stretched at a predetermined ratio (one-stage stretching), and then stretched so as to obtain a predetermined total stretch ratio in hot air ( The monofilament was obtained by two-stage stretching) and 8% relaxation heat treatment in hot air.

  Table 2 shows the types of materials for the core material and the sheath material and the ratio of the core material to the sheath material (weight ratio) in the production of each monofilament. The conditions (extrusion temperature, stretching temperature, stretching ratio, etc.) changed in each example were as follows. The yarn diameters (diameters) of the monofilaments obtained in each example are shown in Table 6.

Example 1
The extrusion temperature was 220 to 245 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 85 ° C., and the stretching ratio was 3.6 times. The temperature of the hot air during the two-stage stretching was 185 ° C., and the total stretching ratio was 5.6 times. Furthermore, the temperature of the hot air during the relaxation heat treatment was set to 165 ° C.

(Examples 2 to 5)
The extrusion temperature was 210-240 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 85 ° C., and the stretching ratio was 3.8 times. The temperature of the hot air during the two-stage stretching was 180 ° C., and the total stretching ratio was 5.6 times. Furthermore, the temperature of the hot air during the relaxation heat treatment was set to 160 ° C.

(Examples 6 to 12)
The conditions were the same as in Examples 2 to 5 except that the temperature of the hot air during the two-stage stretching was changed to 185 ° C and the temperature of the hot air during the relaxation heat treatment was changed to 165 ° C.

［モノフィラメントの製造：比較例１〜８］ (Examples 13 to 19)
The same conditions as in Examples 6 to 12 were used except that the resin for the sheath material and the core material was a material containing a plasticizer in the blending amount shown in Table 2 in addition to nylon. In Table 2, the plasticizer column shows the blending amount (parts by weight) of the plasticizer with respect to 100 parts by weight of nylon.

[Production of monofilament: Comparative Examples 1 to 8]

  In Comparative Examples 1 to 8, monofilaments having no core / sheath structure were produced using a single material. That is, first, a resin (nylon) for forming a monofilament was prepared, put into an extruder, melted at a predetermined extrusion temperature, and spun with a single layer nozzle. The resin discharged from the nozzle is quenched in water, then passed through hot water and stretched at a predetermined ratio (one-stage stretching), and then stretched in hot air to obtain a predetermined total stretch ratio (two-stage stretching). Further, it was subjected to relaxation heat treatment at a predetermined relaxation rate in hot air to obtain a monofilament.

  The types of materials used in each comparative example were as shown in Table 3. In addition, different conditions (extrusion temperature, cooling temperature, stretching temperature, stretching ratio, etc.) in each comparative example were as shown below. The yarn diameters (diameters) of the monofilaments obtained in the respective comparative examples are summarized in Table 7.

(Comparative Example 1)
The extrusion temperature was 230 to 250 ° C. The resin discharged from the nozzle was rapidly cooled at a cooling temperature of 5 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 85 ° C., and the stretching ratio was 3.6 times. The temperature of the hot air during the two-stage stretching was 185 ° C., and the total stretching ratio was 5.3 times. Further, the temperature of the hot air during the relaxation heat treatment was 165 ° C., and the relaxation rate was 5%.

(Comparative Example 2)
The extrusion temperature was 220 to 245 ° C. The resin discharged from the nozzle was rapidly cooled at a cooling temperature of 5 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 85 ° C., and the stretching ratio was 3.8 times. The temperature of the hot air during the two-stage stretching was 185 ° C., and the total stretching ratio was 5.6 times. Furthermore, the temperature of the hot air during the relaxation heat treatment was 165 ° C., and the relaxation rate was 8%.

(Comparative Example 3)
The conditions were the same as in Comparative Example 2 except that the resin used was a resin containing a plasticizer in the amount shown in Table 3. In Table 3, the plasticizer column shows the blending amount (parts by weight) of the plasticizer with respect to 100 parts by weight of nylon.

(Comparative Example 4)
The conditions were the same as in Comparative Example 2 except that the temperature of the hot air during the two-stage stretching was changed to 145 ° C. and the relaxation rate during the relaxation heat treatment was changed to 3%.

  In this comparative example, although a monofilament was obtained, the spinning was slightly unstable, and a thickness unevenness of about 9% was generated on the undrawn yarn. In addition, a phenomenon was observed in which the yarn was attracted to the rotary roll used for taking-up. Furthermore, when the temperature during the two-stage drawing was raised to a normal temperature, yarn fusing was likely to occur, so it had to be lowered to 145 ° C.

(Comparative Example 5)
The conditions were the same as in Comparative Example 2 except that the relaxation rate during relaxation heat treatment was changed to 3%.

  In this comparative example, although monofilaments were obtained, yarn waving occurred during rapid cooling, and a thickness spot of about 7% occurred on the yarn.

(Comparative Example 6)
The conditions were the same as in Comparative Example 2 except that the total draw ratio during the two-stage drawing was changed to 5.6 times and the relaxation rate during the relaxation heat treatment was changed to 3%.

(Comparative Example 7)
The conditions were the same as in Comparative Example 5.

(Comparative Example 8)
The extrusion temperature was 235 to 260 ° C. The resin discharged from the nozzle was rapidly cooled at a cooling temperature of 6 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 88 ° C., and the stretching ratio was 3.4 times. The temperature of the hot air during the two-stage stretching was 195 ° C., and the total stretching ratio was 5.3 times. Further, the temperature of the hot air during the relaxation heat treatment was 175 ° C., and the relaxation rate was 5%.

［モノフィラメントの製造：比較例９〜１４］ In this comparative example, a phenomenon that the yarn was twisted during quenching was observed, but generally good spinning was possible.

[Production of Monofilament: Comparative Examples 9 to 14]

  In Comparative Examples 9 to 14, monofilaments having no core / sheath structure were produced by blending two kinds of materials. The manufacture of monofilaments is the same except that two types of resins (nylon 1 and nylon 2) were mixed in advance according to the types and blending amounts (parts by weight) shown in Table 4 as resins for forming monofilaments. It carried out by the method similar to Examples 1-8. The conditions (extrusion temperature, cooling temperature, stretching temperature, stretching ratio, etc.) that differ in each comparative example were as shown below. The yarn diameters (diameters) of the monofilaments obtained in the respective comparative examples are summarized in Table 7.

(Comparative Example 9)
The extrusion temperature was set to 215 to 245 ° C., and the resin discharged from the nozzle was rapidly cooled at a cooling temperature of 5 ° C., but the two resins were not compatible, the discharged resin was cloudy and opaque, and from the nozzle Because of the large variation in the discharge amount, it could not be taken up and could not be spun.

(Comparative Example 10)
An attempt was made to manufacture a monofilament under the same conditions as in Comparative Example 9, but the two resins were not compatibilized, the discharged resin was cloudy and opaque, and the variation in the discharge amount from the nozzle was large. It could not be taken up and could not be spun.

(Comparative Example 11)
The extrusion temperature was 235 to 250 ° C. The resin discharged from the nozzle was rapidly cooled at a cooling temperature of 8 ° C. Moreover, the temperature of the hot water at the time of one-stage stretching was 80 ° C., and the stretching ratio was 4.0 times. The temperature of the hot air during the two-stage stretching was 190 ° C., and the total stretching ratio was 5.5 times. Furthermore, the temperature of the hot air during the relaxation heat treatment was 170 ° C., and the relaxation rate was 5%.

  In this comparative example, although the resin discharged from the nozzle was slightly cloudy, it could be taken out and a monofilament could be obtained.

(Comparative Example 12)
An attempt was made to produce a monofilament under the same conditions as in Comparative Example 11, but the two resins were not compatibilized, the discharged resin was cloudy and opaque, and the variation in the discharge amount from the nozzle was large. It could not be taken up and could not be spun.

(Comparative Example 13)
An attempt was made to manufacture a monofilament under the same conditions as in Comparative Example 9, but the two resins were not compatibilized, the discharged resin was cloudy and opaque, and the variation in the discharge amount from the nozzle was large. It could not be taken up and could not be spun.

［モノフィラメントの製造：比較例１５及び１６］ (Comparative Example 14)
An attempt was made to manufacture a monofilament under the same conditions as in Comparative Example 9, but the two resins were not compatibilized, the discharged resin was cloudy and opaque, and the variation in the discharge amount from the nozzle was large. It could not be taken up and could not be spun.

[Production of Monofilament: Comparative Examples 15 and 16]

  In Comparative Examples 15 and 16, monofilaments having a core / sheath structure that did not satisfy the conditions of the present invention were produced. Monofilaments were manufactured in the same manner as in Examples 1 to 19 except that the types of the core material and the sheath material and the ratio of the core material to the sheath material (weight ratio) were as shown in Table 5. went. The different conditions (extrusion temperature, stretching temperature, stretching ratio, etc.) in each comparative example were as shown below. The yarn diameters (diameters) of the monofilaments obtained in the respective comparative examples are summarized in Table 7.

(Comparative Example 15)
The conditions were the same as in Examples 6-12.

(Comparative Example 16)
The extrusion temperature was 220 to 245 ° C. for the sheath material and 200 to 265 for the core material. Moreover, the temperature of the hot water at the time of one-stage stretching was 85 ° C., and the stretching ratio was 3.6 times. The temperature of the hot air during the two-stage stretching was 185 ° C., and the total stretching ratio was 5.6 times. Furthermore, the temperature of the hot air during the relaxation heat treatment was set to 165 ° C.

［特性評価１］ In Comparative Example 16, voids that appear to be caused by volume shrinkage due to rapid cooling occurred in the core material made of vinylidene fluoride resin. Moreover, when this was extended | stretched, the extending | stretching fracture | rupture occurred frequently. Even those that could be stretched were peeled off at the interface between the sheath material and the core material, and a good monofilament could not be obtained.

[Characteristic evaluation 1]

  First, for each monofilament obtained in Examples 1 to 19 and Comparative Examples 1 to 16, specific gravity measurement and tensile test were performed as shown below, and the specific gravity, knot strength, knot elongation, tensile strength of each monofilament, Tensile elongation and tensile modulus were measured. The obtained results are summarized in Tables 6 and 7.

In Tables 6 and 7, the spinning state at the time of manufacturing each monofilament is also shown. The spinning states are as follows.
Good: Good spinning was possible.
Almost good: Slightly unstable behavior was observed, but normal spinning was possible.
Unstable: Spinning was unstable to the extent that thick spots occurred, but a monofilament could be obtained.
Bad: A monofilament could not be obtained.

(Specific gravity measurement)
The monofilament was vacuum dried at 60 ° C. for 24 hours, and then the specific gravity was measured using an Accuvic 1330 gas displacement type density measuring device manufactured by Shimadzu Corporation. In addition, this measurement was performed on the conditions of the measurement number (n) = 5 about the monofilament of each Example or the comparative example.

(Tensile test)
Each monofilament was allowed to stand overnight in a room at 23 ° C. and 65% RH, and then in accordance with JIS L 1013, using a Tensilon UTM-III-100 type tensile tester manufactured by Orientec Co., Ltd. The test was conducted under the conditions of length 300 mm, tensile speed 300 mm / min, and measurement number n = 5 in this chamber, thereby measuring nodule strength, nodule elongation, tensile strength, tensile elongation and tensile modulus. The knot strength and the elongation are values measured in the same manner as the tensile strength and the tensile elongation after a test with the knot provided. The value obtained by this is defined as the dry strength.

  As shown in Table 6, the monofilaments obtained in Examples 1 to 19 are sufficiently low in specific gravity so that they do not immediately sink in water, and both have high nodule strength and elongation. As well as tensile strength and elongation. From this, it was confirmed that the monofilament of Examples 1-19 can provide a fishing line suitable for the fishing technique which floats a fishing line on water.

  On the other hand, as shown in Table 7, when only a single type of nylon was used as in Comparative Examples 1 to 8, it was possible to produce a monofilament well, but low specific gravity and high strength ( In particular, it was difficult to achieve both high nodule strength.

  Further, as in Comparative Examples 9 to 14, when two types of nylon were combined to reduce the specific gravity, spinning was difficult and monofilaments were often not obtained well. In Comparative Example 11 in which the content of low specific gravity nylon (Ny12 (B)) was reduced, monofilaments could be obtained only, but sufficient specific gravity could not be reduced.

Further, when nylon having a low amide group concentration is used as the sheath material as in Comparative Example 15, the specific gravity can be reduced similarly to the examples and the like, but the knot strength is extremely low and the tensile elastic modulus is also high. This proved inappropriate for fishing lines. Furthermore, as in Comparative Example 16, when attempting to reduce the specific gravity using a material that is not a polyamide resin for the core material, spinning becomes difficult, and between the core material and the sheath material made of the polyamide resin, It was confirmed that peeling occurred.
[Characteristic evaluation 2]

  In addition, the monofilaments obtained in Examples 1 and 19 and Comparative Examples 1 and 2 were used to evaluate the influence of water absorption on each characteristic as described below.

(Characteristic retention after water immersion)
First, the dry strength (nodule strength, knot elongation, tensile strength and tensile elongation) of each monofilament was measured by the same method as described above. Next, after immersing them in water at 23 ° C. for 6 hours, the monofilament was subjected to the same tensile test to measure the knot strength, knot elongation, tensile strength and tensile elongation. These values are the wet strength. And the ratio (%) which the intensity | strength in the wet changed with respect to the intensity | strength at the time of dryness was calculated | required, and the obtained value was made into the characteristic retention after water immersion. Table 8 shows the obtained results.

(Water absorption rate and shrinkage rate)
First, each monofilament was cut to a length of 1 m to prepare a sample, which was left in the air at 23 ° C. and 65% RH for 24 hours, and then immersed in water at 23 ° C. for a maximum of 24 hours. And the weight of the sample before and after being immersed in water was measured, and the water absorption rate by each sample was computed from the change of this weight. Moreover, the dimension of the sample before and after being immersed in water was also measured, and the rate of change in length (shrinkage) due to water absorption was calculated from the change in dimension. In addition, these values were calculated | required both at the time of 6 hours after the immersion start in water, and the time of 24 hours having passed. Moreover, the said measurement was performed on the conditions of the measurement number (n) = 5 about the monofilament corresponding to each Example or a comparative example. Table 8 shows the obtained results.

  From Table 8, the monofilaments of Examples 1 and 19 have higher property retention after water immersion, and the water absorption rate and shrinkage rate than those of Comparative Example 1 using Ny6 / 66, which is particularly frequently used as a normal fishing line. It was found that the increase in specific gravity due to water absorption can also be suppressed.

It is a perspective view which shows the structure of the edge part vicinity of the monofilament of preferable embodiment.

Explanation of symbols

  1 ... monofilament, 2 ... core material, 3 ... sheath material.

Claims (6)

A core / sheath composite monofilament having a core material extending in the axial direction and a sheath material covering the core material,
The core material and the sheath material are each composed of a polyamide-based resin,
When the number of amide groups per 100 atoms constituting the main chain of the polyamide resin is defined as the amide group concentration, the amide group concentration of the polyamide resin constituting the core material constitutes the sheath material. rather smaller than the amide group concentration of a polyamide resin,
The polyamide resin constituting the core material is nylon 12 or nylon 6/12 having an amide group concentration of 12 or less, and the polyamide resin constituting the sheath material is nylon 6, nylon 66, nylon 6 / 66, or nylon 6/12 having an amide group concentration greater than 12 ;   The monofilament according to claim 1, wherein the sheath material has an amide group concentration of 13 or more.   The monofilament according to claim 1 or 2, wherein the core material has an amide group concentration of 12 or less. A core / sheath composite monofilament having a core material extending in the axial direction and a sheath material covering the core material,
The core material and the sheath material are each composed of a polyamide-based resin,
The specific gravity of the polyamide resin constituting the core material, rather smaller than the specific gravity of the polyamide resin constituting the sheath material,
The polyamide resin constituting the core material is nylon 12 or nylon 6/12 having an amide group concentration of 12 or less, and the polyamide resin constituting the sheath material is nylon 6, nylon 66, nylon 6 / 66, or nylon 6/12 having an amide group concentration greater than 12 ; The monofilament according to any one of claims 1 to 4, wherein the polyamide resin constituting the sheath material is nylon 6/12 having an amide group concentration higher than 12. A fishing line using the monofilament according to any one of claims 1 to 5.

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