JPH0555095B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Oriented polymer monofilaments are widely used as fishing lines. For this purpose, it is important that some of the properties of the filament, which are important when used as a fishing line, are balanced. These properties include tensile strength, impact strength, abrasion resistance,
These include knot strength, flexibility, stretchability and visibility. Over the years, for example, U.S. Pat.
Significant improvements have been made in one or more of these properties, as shown in US Pat. No. 3,156,750 and US Pat. Despite improvements in monofilament fishing lines, a continuing challenge is maintaining a balance between hook setting performance and castability.
Generally, yarns that are sensitive to percussion and yarns that have good hookability are characterized by low elasticity and high tensile strength. However, as stiffness increases and stretchability decreases, the ease of casting monofilament fishing line decreases. Therefore, it has previously been difficult to obtain a material that has both of these seemingly incompatible properties. The present invention provides an improved monofilament fishing line characterized by outstanding hookability and hit (sensitivity) as well as excellent castability. More specifically, the present invention provides a coextruded oriented fishing line having a diameter of about 0.1 to 0.2 mm, which has a substantially circular cross-sectional shape, has a core-sheath concentric structure, and has an oriented type fishing line that constitutes a core. The initial wet tensile modulus of the polymer is at least about 5 times the initial wet tensile modulus of the oriented polymer forming the sheath, and the ratio "α" of the volume fraction of the core to the total volume of the monofilament is (where n is the ratio of the initial wet tensile modulus of the oriented polymer forming the core to the initial wet tensile modulus of the oriented polymer forming the sheath), and the core weight At least 50% of the incorporation is polyamide or polyester. Figures 1 and 2 graphically illustrate the elongation of fishing line under stress. The monofilament of the present invention is a coextruded structure having a sheath and a core. These monofilaments are made by conventional coextrusion techniques, such as those described in US Pat. No. 2,936,482 (incorporated by reference). The core of the coextruded monofilament of the present invention is comprised of at least about 50% polyester or polyamide, preferably at least about 70%, and is formed into a filament and oriented by stretching from about 4.5 to 6 times its original length. It also exhibits a wet tensile strength greater than about 500 MPa and a wet initial tensile modulus greater than about 3500 MPa. The wet tensile strength and wet initial tensile modulus described herein are at least about 2
Determined by ASTM test D-2101-79 on filament samples equilibrated with water at room temperature for hours. A polymer capable of exhibiting the required wet tensile strength and wet initial tensile modulus is:
Poly(hexamethylene dodecanoamide) (nylon 612) and blends containing at least about 80% of this polyamide, poly(hexamethylene sebaamide) (nylon 610) and at least about 80% of this polyamide
Copolymers and polymer blends containing % by weight of this polyamide, as well as poly(dodecanolactam) (nylon 12) and at least about 80% by weight
Polyamides such as copolymers and polymer blends containing this polyamide are included. Other polymers exhibiting the required wet tensile strength and initial wet tensile modulus include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and each of these with other polymers such as each other and elastomers. Includes a blend of Elastomers that can be used in this manner include, for example, copolyetheresters such as those commercially available as Hytrel copolyetheresters from EI du Pont de Nemours & Company. Particularly desirable polymer blends for use as core materials in the coextruded monofilaments of the present invention include:
It is a copolymer of at least about 80% polyethylene terephthalate and at least about 5% terephthalic acid and isophthalic acid with 1,4-butanediol and polytetramethylene ether glycol. The copolyester esters described above can be prepared according to the teachings of US Pat. No. 3,651,014 and US Pat. No. 3,763,109, both of which are incorporated by reference. Factors that influence the wet tensile strength and initial wet tensile modulus of the polymer used for the core are:
Includes molecular weight, stretch ratio and composition. Generally, the required wet tensile strength and wet initial tensile modulus are achieved with a number average molecular weight of at least about 12,000. Polymers that can be used for the coextruded monofilament sheath of the present invention are those that exhibit a wet tensile strength of greater than about 500 MPa and a wet initial tensile modulus of greater than about 1400 MPa. Polymers that can exhibit these properties include polycaprolactam (nylon 6) or blends of nylon 6 with other polymers, where nylon 6 represents at least about 60% of the blend. Typical polymers that can be blended with nylon 6 include nylon 11, nylon 12 and nylon 6,6. Nylon 6 can also be blended with copolymers of nylon 6 or one or more other nylons, such as nylon 11, nylon 12, and nylon 6,6. The relative proportions of the polymers that make up the sheath and core of the monofilament fishing lines of this invention can vary widely. However, the core should represent about 10-50% of the total weight of the coextruded monofilament. The approximate volume fraction of core to total filament, "α", is specified by the following relationship: (where n is the ratio of the initial wet tensile modulus of the aligned polymer forming the core to the initial wet tensile modulus of the oriented polymer forming the sheath).
Within the tensile modulus requirements set forth above, the ratio of the tensile modulus of the core material to the tensile modulus of the oriented polymer making up the sheath should be greater than about 5, and a ratio greater than about 10 is particularly important for the core. has been found to provide the finished fishing line with particularly desirable performance characteristics when it consists of at least about 50% polyethylene terephthalate. After coextruding the sheath material and core material, the coextruded material is oriented by stretching it to about 4.5 to 6.0 times its original length, preferably about 5.0 to 5.7 times its original length. to increase the strength of the monofilament. This compounded monofilament has a diameter of about 0.1-1.2 mm depending on the pound test required for fishing line. A particularly satisfactory alignment technique is the U.S. Patent No.
This is a two-stage stretching method described in No. 3156750.
After orientation, the coextruded monofilament can be further processed to improve other physical properties, such as by steam conditioning as described in US Pat. No. 3,595,952. The preferred combination of a polyethylene terephthalate polymer blend for use as the core and nylon 6 as the sheath provides particularly outstanding performance characteristics as a fishing line. Furthermore, these two
The two basic components are particularly easy to manufacture in that the melt processing temperatures of the core and sheath polymers are relatively close and the drawing properties are compatible with the orientation of the coextruded monofilament. The invention is further illustrated by the following specific examples. Examples and percentages are by weight unless otherwise specified. Example 1 and Comparative Examples A-C In Example 1, a coextruded filament was produced consisting of a core containing an extruded blend of 9% Hytrel 7246 copolyetherester and 91% poly(ethylene terephthalate) and a polycaprolactam sheath. and tested. Mix the dry pellets of the polymer that makes up the core,
It was fed into an extruder maintained at about 280°C. The molten blend was then delivered to the spin head through the spin pump. At the same time, the dry polymer constituting the sheath was fed to an extruder maintained at approximately 260°C. The melt from the sheath was also sent to the spin head through a metering pump. The spinhead was kept at approximately 260°C. The two melts are combined in a spin head and 4
Two coextruded filaments were obtained. The sheath and core metering pump was adjusted so that 25% of the coextruded filament volume was core. The filaments were quenched in water at 20°C, oriented by a two-stage drawing process, and relaxed with steam to determine knot strength. The resulting 0.32 mm filament was wound onto a spool. The breaking load of this filament after being wetted for 2 hours was 43.2N (9.7
lb). The ratio of the initial wet tensile modulus of the blended polymer forming the sheath to that of the blended polymer forming the core is 10. The volume fraction of the wick relative to the total volume of the monofilament, α, is 0.25. In Comparative Examples A, B, and C, nylon monofilament fishing lines were obtained from commercial sources. Comparative example A
uses Dupont's 53.4N (12 lb.) tested Stren clear monofilament fishing line (0.35 dia.
mm, commercially available from E.I. Dupont de Nemours & Company).
Example B is a 53.4N (12 lb) test Trilene XL fluorescent clear/blue fishing line (0.33 dia.
mm, commercially available from Berkeley & Company). Example C is 53.4N (12 pounds)
Test Sigma Transparent Blue Fluorescent Fishing Line (Diameter
0.34 mm, commercially available from Shakespeare Company). The fishing lines of Example 1, Comparative Examples A, B and C were 23
Placed in a pan filled with water at ℃. The thread was soaked until it reached equilibrium with the water. Next, cut each thread individually from 0 to 60
cm tensile force measurements were recorded. The results are shown in Figure 1. The coextruded filaments of the present invention exhibited significantly greater resistance than Comparative Examples A, B, and C at low elongations and were therefore more sensitive to fish hits. Example 2 and Comparative Examples D and E In Example 2, the monofilament had a diameter of 0.29 mm.
A coextruded filament was made from the same material by the same procedure as in Example 1, except that it had a 2 hour wet failure load of 38.7 N (8.7 lbs). In Comparative Examples D and E, nylon monofilament fishing lines were obtained from commercial sources. Example D is 35.6N
(8 lb.) Test Strain Clear monofilament fishing line (0.28 mm diameter). Comparative example E is
35.6N (8 lbs) Test Trilene XL Fluorescent Clear/
It is a blue fishing line (0.26mm in diameter). These fishing lines were tested in a 9 m long pan as in Example 1 and Comparative Examples AC. The results are shown in Figure 2. The coextruded monofilaments of the present invention exhibit significantly greater resistance than those of Comparative Examples D and E. Examples 3-8 and Comparative Examples F-1 In Examples 3-8 and Comparative Examples F-H, coextruded monofilaments were made as in Example 1, except that different core polymers were used. All of these filaments have a polycaprolactam sheath. The table shows the core polymers and their proportions for these filaments. After conditioning the filament to equilibrate with water at 23°C, the samples were tested on an Instron tensile tester. The stress at 1, 5 and 10% elongation is shown in the table. The ratio of the wet initial tensile modulus of the sheath to that of the core (n) and the percentage of core to the total volume of the monofilament are also shown in the table. In Comparative Example I, DuPont's 75.6N (17 lbs.)
Test Strain Monofilament fishing line was obtained from a commercial product. This filament was tested as above and
The data obtained are shown in the table. As a result of Examples 3-8 all having high modulus, low stretch cores, the stresses of the coextruded filaments at 1, 5, and 10% elongation are greater than the nylon monofilament of Comparative Example I. Comparative Examples G and H are coextruded filaments with polycaprolactam core and sheath.
The stress values indicate that there is no advantage to coextruding the same polymers. Comparative Example F is a coextruded filament with a polyethylene core. The initial wet tensile modulus of polyethylene is similar to polycaprolactam at the stretch ratio used. Therefore, this stress value is lower than Comparative Example I, indicating that there is no advantage to coextruding filaments with cores of similar or lower modulus. 【table】

[Brief explanation of the drawing]

FIG. 1 graphically shows the elongation under stress of the fishing lines of Example 1 and Comparative Examples A, B and C. FIG. 2 graphically shows the elongation under stress of the fishing lines of Example 2 and Comparative Examples D and E.

Claims (1)

[Scope of Claims] 1. A coextruded oriented monofilament fishing line having a diameter of about 0.1 to 1.2 mm, which has a substantially circular cross-sectional shape, has a core-sheath concentric structure, and has an oriented core. the initial wet tensile modulus of the type polymer is at least about 5 times the initial wet tensile modulus of the oriented polymer forming the sheath, and the ratio "α" of the volume fraction of the core to the total volume of the monofilament is (where n is the ratio of the initial wet tensile modulus of the oriented polymer forming the core to the initial wet tensile modulus of the oriented polymer forming the sheath). 2. When the core is polyamide and is formed into a filament and stretched and oriented to about 4.5 to 6.0 times its original length, the initial wet tensile strength is greater than about 500 MPa and the initial wet tensile modulus is greater than 3500 MPa. The coextruded fishing line according to claim 1, which shows: 3. Claim 2 in which the core comprises at least about 80% poly(hexamethylene dodecanoamide)
Coextruded monofilament fishing line as described in Section 1. 4. Claim 2 in which the core comprises at least about 80% by weight poly(hexamethylene sebaamide)
Coextruded monofilament fishing line as described in Section 1. 5 When the core is polyester and it is stretched and oriented to approximately 4.5 to 6.0 times its original length, approximately
The coextruded monofilament fishing line of claim 1 exhibiting a wet tensile strength of greater than 500 MPa and a wet initial tensile modulus of greater than about 3500 MPa. 6. The coextruded monofilament of claim 5, wherein the initial wet tensile modulus of the oriented polymer forming the core is at least about 10 times the initial wet tensile modulus of the oriented polymer forming the sheath. fishing line. 7. The coextruded monofilament fishing line of claim 6, wherein the core is at least about 50% polyethylene terephthalate. 8. The core of claim 6, wherein the core is a copolymer of at least about 80% polyethylene terephthalate and at least about 5% tere- and isophthalic acid with 1,4-butanediol and polytetramethylene ether glycol. Co-extruded monofilament fishing line. 9. Claims in which the sheath polymer exhibits a wet tensile strength of greater than about 500 MPa and an initial wet tensile modulus of less than about 1400 MPa when stretched and oriented to about 4.5 to 6.0 times its original dimensions. The coextruded monofilament fishing line according to item 1. 10. The coextruded monofilament fishing line of claim 9, wherein the sheath comprises at least about 50% polycaprolactam.