JP2003027345A - Biodegradable fishing line and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable fishing line resistant to permanent deformation and having performance required as a fishing line and biodegradability and provide a method for efficiently producing the biodegradable fishing line. SOLUTION: The fishing line is a monofilament of a biodegradable synthetic resin having a tensile strength of >=500 MPa, a knot strength of >=350 MPa and a flexural recovery factor of >=60%. The fishing line is produced by carrying out the melt-spinning, cooling, drawing and heat-setting of a biodegradable resin, winding the obtained monofilament, rewinding the wound monofilament in the form of a hank and subjecting the hank to relaxed treatment in a warm water of 35-65 deg.C for 3-60 min.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable fishing line which is difficult to be squeezed and has both basic performance as a fishing line and biodegradability, and an efficient method for producing the same.

[0002]

2. Description of the Related Art As a conventional fishing line material, a synthetic resin mainly composed of polyamide, polyester, polyolefin and polyvinylidene fluoride has been used because of its required mechanical properties. However, since fishing lines made of synthetic fibers made from these synthetic resins hardly decompose in the natural environment, they should remain semi-permanently in the natural world if they are discarded or left unused after use. Therefore, this has become a major environmental health problem.

In other words, the discarded waste fishing line stands on the seabed and interferes with the reproduction of fish, and the waste fishing line is often entangled with birds and marine life and killed. And the improvement was strongly desired from both sides of nature conservation.

Therefore, recently, a fishing line which is naturally disappeared by fungi and microorganisms in the natural world after the practical use, that is, a biodegradable fishing line has been actively developed.

As a conventional technique relating to these biodegradable fishing lines, (A) fishing line made of polylactide (Japanese Patent Laid-Open No. 183428/1993) and (B) fishing line made of polyglycolic acid (Japanese Patent Laid-Open No. 3-183428). No. 259029), (C) a fishing line comprising polycaprolactone monofilament (JP-A-5-59611), and (D) a fishing line having both a basic performance as a fishing line and an appropriate biodegradation rate (JP-A-9- No. 74961) has already been proposed.

However, the above-mentioned biodegradable fishing lines (A) and (B) are both hard and fragile in terms of material and have low knot strength, so they satisfy the basic performance as a fishing line. Is hard to say. Further, since the biodegradable fishing line of (C) has a low melting point of about 60 ° C., it has a drawback that scratches and creases are likely to occur due to scratching.
The (D) biodegradable fishing line has a certain improvement effect in that it has both basic performance as a fishing line such as strength and appropriate biodegradability, but it is one of the other important characteristics of the fishing line. There is a problem with a certain string, and since the string is likely to occur, there is a problem that the operability during casting and winding is poor.

Therefore, the conventional biodegradable fishing line is not necessarily satisfactory in its improvement effect in that it has both the performance required for the fishing line such as the lineability and mechanical properties and the biodegradability. It ’s hard to say,
The reality is that the improvement is strongly desired.

[0008]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying how to solve the above-mentioned problems in the prior art.

[0009] Therefore, an object of the present invention is to provide a biodegradable fishing line which is less likely to be lined and has both the performance and biodegradability required as a fishing line, and a method for efficiently producing this biodegradable fishing line. To do.

[0010]

In order to achieve the above object, the biodegradable fishing line of the present invention is a fishing line composed of a monofilament of a biodegradable synthetic resin, which is JISL101.
The tensile strength measured according to the rule of 3 is 500 MPa or more, the knot strength is also 350 MPa or more, and a pair of two loops crossed from the monofilament sample is formed,
The upper loop is fixed to the stopper plate, and the load is applied to the lower loop (load [1/2] of monofilament fineness [denier] [g]
Weight) was applied for 3 minutes, and then a pair of pine needle-shaped samples formed at the intersections of the loops were cut to a length of about 3 cm and collected, and the samples were left for 60 minutes and then measured for the open angle ( The bending recovery rate calculated by the equation (θ / 180) × 100 from 60) is 60% or more.

In the biodegradable fishing line of the present invention,
The following conditions (1) to (4) are preferable conditions, and by satisfying these conditions, it is possible to expect to obtain a more excellent effect.

(1) The biodegradable synthetic resin is an aliphatic polyester, (2) the aliphatic polyester is selected from polyalkylene dicarboxylates, polylactic acid and poly (β-hydroxyalkanoate) s. And (3) the aliphatic polyester is at least one of polyalkylenedicarboxylates having a melting point of 70 ° C. or higher, and (4) the polyalkylenedicarboxylate having a melting point of 70 ° C. or higher, At least one selected from polybutylene succinate, polyethylene succinate, and polybutylene (succinate / adipate).

In the method for producing a biodegradable fishing line according to the present invention, the biodegradable resin is melt-spun, cooled, stretched, heat-fixed, and once wound, the monofilament is rewound into ridges, and then the ridges are removed. It is characterized by being subjected to relaxation treatment in warm water of ~ 65 ° C for 3 to 60 minutes.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

First, the biodegradable synthetic resin used in the present invention is preferably an aliphatic polyester typified by polyalkylene dicarboxylates, polylactic acid and poly (β-hydroxyalkanoate) s. It may be a biodegradable resin (eg, a semi-aromatic polyester such as polybutylene succinate / terephthalate) capable of sufficiently exhibiting the performance as a fishing line such as, but is not necessarily limited thereto.

The aliphatic polyester used in the present invention has a melt index (hereinafter referred to as MI) measured under the conditions of 190 ° C. and a load of 2.16 Kg.
Is particularly preferably 10 g / min or less and a melting point of 70 ° C. or higher. Here, when the MI exceeds 10 g / min, the strength required for the fishing line is difficult to develop, and when the melting point falls below 70 ° C., there is a problem in heat resistance such as when the fishing line is left in a car in the summer. It will happen.

Specific examples of the above polyalkylene dicarboxylates include polybutylene succinate, polyethylene succinate and polybutylene succinate /
Adipate) and the like, but are not limited thereto.

The polylactic acid may be poly-L-
Examples thereof include, but are not limited to, lactic acid, poly-D-lactic acid, and a copolymerized polymer having a mixture of L-lactic acid / D-lactic acid / racemic lactic acid as a monomer.

Further, as the above poly (β-hydroxyalkanoates), poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, and poly-3 are used.
-Hydroxy (butyrate / valilate) and the like, but not limited thereto.

Each of the above-mentioned polymers used in the present invention has various additives such as pigments, dyes, light stabilizers, ultraviolet absorbers, antioxidants, crystallization inhibitors, and plasticizers. Can be added as long as it does not inhibit the polymerization process, after the polymerization, or immediately before spinning.

The biodegradable fishing line of the present invention comprising a monofilament of the above biodegradable synthetic resin has a tensile strength of 500 MPa or more, particularly 600 MPa or more, and a knot strength of 350 MPa or more, particularly 450 MPa or more, as measured according to JIS L1013. And make a set of two loops intersecting from the monofilament sample, fix the upper loop to the stopper plate, and load the lower loop with a load (1/2 of the monofilament fineness [denier] [g] weight). 1) formed at the intersection of the loops after 3 minutes
A pair of pine-bent bent samples were cut to a length of about 3 cm, collected, left for 60 minutes, and then measured from the open angle (θ). The bending recovery rate was calculated by the formula (θ / 180) × 100. Is more than 60%, especially more than 65%.

Here, the tensile strength and the knot strength are
It is an important property for the proof stress that can withstand the force applied when the fish is caught on the fishing line.If the tensile strength and knot strength are less than the above ranges, the mechanical properties required for the fishing line will not be sufficiently satisfied and high cutting (linear cutting) This results in fishing lines that are prone to problems such as thread breakage at parts) and thread breakage at knots.

Further, the above-mentioned bending recovery rate is an important characteristic with respect to the twisting of the fishing line. If the bending recovery rate is less than the above range, the twisting tends to occur and the operability during casting or winding is poor. Will be.

That is, a fishing line made of a conventional biodegradable resin has a highly oriented and highly crystallized fiber structure because it is highly stretched for the purpose of increasing the strength, which causes a twisting due to the stretching strain. It was easy to do.
Here, the thread line related to fishing line is a line that is generated by rubbing with obstacles such as guides and rocks, a line that appears when it is wound around a winding tool such as a piece and then released, and cast from the reel. It means a curl or the like generated by repeatedly applying elongation to. It is a generally well known fact that one of the causes of these yarn creases is stretching strain. As a method for removing this stretching strain, after a single-stage or multi-stage drawing, it is possible to determine a proper level. Long,
Relaxation heat fixation is performed.

However, a fishing line obtained from a biodegradable synthetic resin typified by polyalkylene dicarboxylates has a lower melting point and a twisted line as a material, as compared with existing polyamide fishing lines and fluorocarbon fishing lines. Since it is easy to perform, since the conventional method has not reached the satisfactory improvement level of the liner, only the biodegradable fishing line, which has a difficulty in operability during casting and winding, has been obtained. is there.

However, according to the present invention, it has been found that the evaluation of the stringiness of the biodegradable fishing line is accurately represented by the bending recovery rate, and this bending recovery rate and the above-mentioned tensile strength and knot strength. By satisfying the above ranges, it is possible to realize a biodegradable fishing line having both the performance required as a fishing line such as the stringing and mechanical properties and the biodegradability.

The biodegradable fishing line of the present invention having the above characteristics can be efficiently produced by the method described below.

First, when melt-spinning a biodegradable synthetic resin, usual conditions using an extrusion spinning machine can be adopted. For example, a polymer temperature is 170 to 240 ° C., an extrusion pressure is 10 to 500 Kg / cm ² , and a spinneret. Pore size 0.1-5m
m, spinning speed 0.3 to 100 m / min, and other conditions can be appropriately selected.

The monofilaments spun from the extruder spinneret are cooled in a cooling bath after passing through a short gas zone, the cooling medium here being a polymer-inert liquid, usually water. Used. Further, the cooling temperature needs to be 60 ° C. or lower, and if it is cooled at a temperature higher than 60 ° C., the stretchability in the next stretching step may be hindered.

The cooled and solidified monofilament is continuously sent to the first stage of the stretching process, and the atmosphere (bath) for stretching and heat setting is a heated heat medium such as hot water, polyethylene glycol, glycerin and silicone oil. A bath, a dry heat gas bath, a steam bath and the like are used.

Next, the conditions for stretching are different depending on the polymer constituting the monofilament,
Usually, the first stage drawing is first set to a draw ratio of 2.5 to 5.0, and then the total draw ratio is 5.0 or more (preferably 5.
The second stage or the second to third stage multistage stretching is performed at a stretching ratio of 5 times or more).

After the multi-stage stretching, moderate constant length and relaxation heat fixing can be carried out for the purpose of removing stretching strain as required.

Next, in the present invention, the monofilament thus obtained is once rewound into a ridge shape, and then the ridge is 35 to 65 ° C., more preferably 40 to 60 ° C.
In warm water at ℃ for 3 to 60 minutes, more preferably 10 to 3
It is important to perform a relaxation treatment for 0 minutes. Processing temperature is 35
When the temperature is lower than 0 ° C or the treatment time is less than 3 minutes, the improvement of the thread weaving aimed at by the present invention is insufficient, and the treatment temperature is 6
If the temperature exceeds 5 ° C or the treatment time exceeds 60 minutes, the strength required as a fishing line is significantly reduced, which is not preferable. Further, the shape of the ridge is not particularly limited, but generally, the perimeter is about 150 cm and the total length is about 2000 m.

As described above, in a completely relaxed state in which the fishing line is in the shape of a cord, by applying an appropriate warm water treatment at a relatively low temperature, the threading is improved to a satisfactory level with almost no decrease in strength. can do.

The thus-obtained biodegradable fishing line of the present invention sufficiently satisfies the tensile strength and knot strength required for fishing lines, and the line-break, which has been a problem of the biodegradable fishing line, is dramatically improved. Since it is improved and has biodegradability and is desirable for both environmental protection and natural protection, it is extremely useful for various fishing applications.

[0036]

EXAMPLES Next, the present invention will be explained based on examples. The fishing line in the examples was evaluated according to the following methods. [Tensile strength and knot strength]: Measured according to JIS L1013. [Bending recovery rate]: A set of two loops crossed from a monofilament was formed, the upper loop was fixed to a stopper plate, and the lower loop was loaded with a load (1/2 of the fiber fineness [denier] [g]). Weight) for 3 minutes. Next, a pair of pine needle-shaped samples formed at the intersections of the loops were cut to a length of about 3 cm, collected, and allowed to stand for 60 minutes, after which the open angle (θ) was measured, and the sample was bent by the following formula. The recovery rate was calculated.

Bending recovery rate (%) = (θ / 180) × 100 The number of measurements was 4 and the average value was shown. The larger the value, the better the bending recovery.

Example 1 Succinic acid / adipic acid (80
/ 20 mol%) and a random copolymer with 1.4 butanediol (MI: 1.0 g / 10 min, melting point 95 ° C ....
230 A of polymer A1) in an extruder type spinning machine
It was melted at 0 ° C, spun through a spinneret having a pore size of 1.5 mm, and further cooled in a water bath at 20 ° C.

Next, this unstretched yarn was stretched 4.3 times (E1) in a first stage drawing bath of hot water at 70 ° C., and subsequently at 85 ° C.
Was stretched to 2.21 times (E2) in the second-stage dry heat bath to obtain a monofilament having a total draw ratio (E1 × E2) of 9.5 times. Subsequently, it was passed through a dry heat bath at 80 ° C. at a treatment magnification of 0.9 times, heat-fixed, and once wound on a bobbin.

Then, the monofilament was cut to have a circumference of 15
0 cm, 2,000 m long, rewound, and soaked in a fully relaxed state in a warm water bath at 50 ° C for 15 minutes.
mm fishing line was obtained.

Example 2 Polybutylene succinate (MI: 1.2 g / 10 minutes, melting point: 114 ° C .... Polymer B1) was melt-spun and cooled in the same manner as in Example 1 to obtain an undrawn yarn.

Next, this undrawn yarn was drawn 3.7 times (E1) in the first drawing bath of warm water at 80 ° C., and subsequently at 95 ° C.
Was drawn 2.03 times (E2) in the second-stage dry heat bath to obtain a monofilament having a total draw ratio (E1 × E2) of 7.5 times. Subsequently, it was passed through a dry heat bath at 80 ° C. at a treatment magnification of 0.9 times, heat-fixed, and once wound on a bobbin.

Then, this monofilament was made to have a circumference of 15
0 cm, 2,000 m long, rewound, and soaked in a fully relaxed state in a warm water bath at 50 ° C for 15 minutes.
mm fishing line was obtained.

Example 3 Succinic Acid / Adipic Acid (80
/ 20 mol%) and a random copolymer of 1.4 butanediol (MI: 0.5 g / 10 min, melting point: 95 ° C.)
50/50 (parts by weight) of polymer A2) and polybutylene succinate having a melting point of 114 ° C. (polymer B2)
Blend polymer (MI: 0.5 when the mixed composition melts)
g / 10 min) was melt-spun and cooled in the same manner as in Example 1 to obtain an undrawn yarn.

Next, the undrawn yarn was drawn 3.7 times (E1) in the first drawing bath of warm water at 80 ° C., and subsequently at 95 ° C.
Was drawn to 2.11 times (E2) in the second-stage dry heat bath to obtain a monofilament having a total draw ratio (E1 × E2) of 7.8 times. Then, it was passed through a dry heat bath at 80 ° C. with a treatment magnification of 0.8 times, heat-fixed, and once wound on a bobbin.

Then, this monofilament was made to have a circumference of 15
It was rewound into a ridge shape having a length of 0 cm and a total length of 2000 m, immersed in a warm water bath at 50 ° C. for 15 minutes in a completely relaxed state, and the ridges taken out were air dried to obtain a fishing line having a diameter of 0.22 mm.

Example 4 Polymer A used in Example 3
2 and 50/50 (part by weight) of a blended polymer of polyethylene succinate (polymer C1) having a melting point of 104 ° C. (MI: 0.5 g / 10 min when the mixed composition melts) was melted in the same manner as in Example 1. An undrawn yarn was obtained by spinning and cooling.

Next, the undrawn yarn was drawn 4.3 times (E1) in a first hot water bath at 75 ° C., and then at 90 ° C. for 2 times.
A monofilament having a total draw ratio (E1 × E2) of 8.5 times was obtained by drawing 1.98 times (E2) in a stage dry heat bath. Subsequently, it was passed through a dry heat bath at 80 ° C. at a treatment magnification of 0.9 times, heat-fixed, and once wound on a bobbin.

Next, this monofilament was made to have a circumference of 15
0 cm, 2,000 m long, rewound, and soaked in a fully relaxed state in a warm water bath at 50 ° C for 15 minutes.
mm fishing line was obtained.

[Comparative Example 1] A diameter of 0.2 was obtained in the same manner as in Example 1 except that the treatment of hot water in the form of ridges was omitted.
A fishing line of 2 mm was obtained.

[Comparative Example 2] A diameter of 0.2 was obtained in the same manner as in Example 2, except that the hot water treatment in the form of ridges was omitted.
A fishing line of 2 mm was obtained.

[Comparative Example 3] A fishing line having a diameter of 0.22 mm was obtained in the same manner as in Example 1, except that the conditions for forming the ridges and applying the hot water treatment were changed to 70 ° C for 15 minutes.

[Comparative Example 4] A fishing line having a diameter of 0.22 mm was obtained in the same manner as in Example 1, except that the conditions for forming the ridges and applying the hot water treatment were changed to 30 ° C for 15 minutes.

[Comparative Example 5] A fishing line having a diameter of 0.22 mm was obtained in the same manner as in Example 1 except that the condition of applying the hot water treatment in the form of ridges was changed to 50 ° C for 1 minute.

[Comparative Example 6] A fishing line having a diameter of 0.22 mm was obtained in the same manner as in Example 1, except that the condition of applying the hot water treatment in the form of ridges was changed to 50 ° C for 120 minutes.

Table 1 also shows the results of evaluating the characteristics of the fishing lines obtained in Examples 1 to 4 and Comparative Examples 1 to 6.

[0057]

[Table 1] As is clear from the results shown in Table 1, all of the biodegradable fishing lines of the present invention (Examples 1 to 4) have high tensile strength and knot strength required for fishing lines, and have a dramatic bending recovery rate. In addition, it has an excellent performance in which the stringing, which has been a difficulty of the conventional biodegradable fishing line, is remarkably improved.

On the other hand, the biodegradable fishing lines (Comparative Examples 1 and 2) which were not subjected to the hot water treatment of the present invention had an inadequate flexion recovery rate, and due to a method out of the condition range of the production method of the present invention. The obtained biodegradable fishing lines (Comparative Examples 3, 4, 5 and 6) had insufficient tensile strength, knot strength and bending recovery rate, and sufficiently satisfied the effect aimed at by the present invention. Was not.

[Example 5] The biodegradable fishing line of Example 1,
The biodegradable fishing line of Comparative Example 1 was actually used as a lure fishing line, and the state of the fishing line after repeating casting several tens times was compared and observed. As compared with the biodegradable fishing line of No. 1, the line curl was extremely slight.

[0060]

As described above, the biodegradable fishing line of the present invention sufficiently satisfies the tensile strength and knot strength required as a fishing line and, at the same time, has a significant difficulty in the biodegradable fishing line. In particular, it is biodegradable and desirable for both environmental protection and natural protection, and thus is extremely useful for various fishing applications.

Further, according to the method for producing a biodegradable fishing line of the present invention, the biodegradable fishing line having the above-mentioned excellent characteristics can be obtained by adding a simple means of making the fishing line into a ridge shape and performing hot water treatment. Can be manufactured efficiently.

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Claims (6)

[Claims] 1. A fishing line comprising a monofilament of biodegradable synthetic resin, having a tensile strength of 500 MPa or more, a knot strength of 350 MPa or more, and two filaments crossed from a monofilament sample as measured according to JIS L1013. Make a pair of loops, fix the upper loops to the stopper plate, apply a load (weight of [1/2] of monofilament fineness [denier] to the lower loops) for 3 minutes, and then form at the intersection of the loops A pair of pine needle-shaped bent samples thus cut were cut to a length of about 3 cm, collected, left for 60 minutes, and calculated from the open angle (θ) measured by the formula (θ / 180) × 100. Flexion recovery rate is 60%
The biodegradable fishing line characterized by the above. 2. The biodegradable fishing line according to claim 1, wherein the biodegradable synthetic resin is an aliphatic polyester. 3. The aliphatic polyester according to claim 1, wherein the aliphatic polyester is at least one selected from polyalkylene dicarboxylates, polylactic acid and poly (β-hydroxyalkanoate) s. Biodegradable fishing line. 4. The aliphatic polyester is at least one kind of polyalkylene dicarboxylates having a melting point of 70 ° C. or higher, and any one of claims 1 to 3.
The biodegradable fishing line according to the item. 5. The polyalkylene dicarboxylate having a melting point of 70 ° C. or higher is at least one selected from polybutylene succinate, polyethylene succinate and polybutylene (succinate / adipate). 4. The biodegradable fishing line according to any one of 4 to 4. 6. A biodegradable resin is melt-spun, cooled, drawn,
After heat fixing and once winding, the monofilament is rewound into a ridge shape, and the ridge is then rehydrated in warm water at 35 to 65 ° C for 3 to
The method for producing a biodegradable fishing line according to any one of claims 1 to 5, wherein the relaxation treatment is performed for 60 minutes.