JPS5838530B2 - polyester fishing net thread - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fishing net yarn made of polyester fibers that is strong and resistant to deterioration.

Nylon and polyethylene are often used as fishing net threads, but in the field of knotless nets, there is no problem of reduced knot strength, which is a drawback of polyester fibers, and the performance does not change even when polyester fibers get wet. In addition to its characteristics of quick drying and ease of handling, its use has increased in recent years due to its good network stability, high specific gravity, and excellent frictional strength.

However, sometimes polyester fishing net thread that has been used for more than a year,
A phenomenon in which an abnormal decrease in strength occurs may be observed, and when using large-scale and fine knotless nets such as purse seine nets, it is difficult to repair them. There were cases where this was an obstacle.

As a result of extensive research into the cause of this, the present inventor found that the concentration of carboxyl group terminals in polyester is an important factor in the decrease in tenacity, and was able to discover a polyester fishing net yarn that exhibits a very small decrease in tenacity, thus arriving at the present invention.

The present invention has a single fiber denier of 5 to 30 denier and a breaking strength and elongation of 5.5 to 5.5, respectively. / Denier or more and 20%
Above, single fiber denier X and carboxyl group terminal concentration y
(equivalent/polymer 106?) is a polyester fishing net yarn characterized by being made of multifilaments satisfying the following formula.

In the present invention, since the single fiber denier constituting the multifilament is 5 denier or more, a fishing net with good abrasion resistance can be obtained, and if it is a knotless net, there is no decrease in strength due to the thick single fiber denier. This is even more preferable because it can be avoided.

The single fiber denier is particularly preferably in the vicinity of 8.5 denier to 30 denier, and more preferably greater than 10 denier and less than 30 denier, and it is difficult to spin yarn with a denier of 30 denier or more.

In the fishing net of the present invention, a considerable impact force is applied, so
Breaking strength and elongation are 5.5 S'/denier or more and 20%, respectively.
It is necessary that there be more than one.

Further, it is more preferable that the elongation at break is 23% or more.

Further, the polyester fiber used in the present invention preferably has an intrinsic viscosity [η] of 0.60 to 1.00.

If it is less than 0.60, the strength and elongation and durability of a fishing net thread cannot be obtained, and if it is more than 1.00, spinning becomes difficult.

The terminal carboxyl group concentration needs to satisfy the above formulas (1) and (2), and y is 50 (equivalent/polymer 10
6 P) or less is required; if it is thicker than this, no matter how large the single fiber denier is, it will not be effective in preventing strength deterioration.

It has been empirically determined that y and y have a relationship with There is an advantage.

The terminal carboxyl group concentration can be adjusted by controlling the polymerization conditions, particularly the temperature and degree of vacuum, and the higher the polymerization temperature, the higher the concentration for the same degree of polymerization.

In the spinning process, the degree of polymerization generally decreases due to thermal decomposition, and the concentration increases.

Also, in the stretching heat treatment process, when the degree of polymerization decreases, the above concentration increases.

The polymer constituting the fishing net yarn made of polyester fibers of the present invention is a polyester containing 90 mol% or more, preferably 95 mol% or more of polyethylene terephthalate repeating units in the molecular chain.

The polyester is preferably polyethylene terephthalate, but it may contain other copolymer components in an amount of less than 10 mol%, preferably less than 5 mol%.

Examples of such copolymerization components include isophthalic acid,
Examples include naphthalene dicarboxylic acid, adipic acid, oxybenzoic acid, diethylene glycol, propylene glycol, trimellitic acid, and pentaerythritol.

These polyesters may also contain additives such as stabilizers and colorants.

The fishing net yarn of the present invention is usually dyed, and the lower the flood shrinkage rate at that time, the better, but it is preferable that the shrinkage rate is 4% or less, more preferably 3.5% or less. This is important in so-called knotless nets such as Raschel nets and knitted nets, in which knotless nets are mainly used.

y mentioned above is 1.0 in the state of drawn yarn after drawing in benzyl alcohol solution? /dl, using phenol as an indicator, put % normal NaOH/benzyl alcohol mixed reagent ('4.5S' NaOH into a volumetric flask, add 8% pure water and 10% ethyl alcohol.
Dissolved at 0 r/Ll, titrated by adding Hensyl alcohol to adjust the concentration to 11, and expressed as equivalent weight with respect to polymer 1061.

The breaking strength is the value obtained by dividing the strength at break by the denier before the test when the sample is pulled at a speed of 120% per minute with a Schopper tensile tester at 20 ° C. and 65% RH,
The elongation at break is 11 mm ((ll-10) l when a sample with a length of 1 o is cut under the same conditions.

]×100%. The flood contraction rate is the length l
.

After immersing the sample in boiling water for 30 minutes, the sample length is 1□ to C.
(to-It)/1o)x1o.

This is the value calculated in %.

The polyester yarn for fishing net line as described above can be advantageously produced, for example, under the following conditions.

That is, undrawn filaments obtained by a conventional method are
2.5 between a supply roller heated to 110°C, preferably 70-105°C, and a stretching roller heated to 150-230°C.
Stretched to ~6 times, then 13% or less, preferably 7 to 11
% and subjected to limited shrinkage treatment (using a non-heated relaxation roller).

The contact residence time of the yarn on the drawing roller is 0.03 to 2 seconds, preferably 0.06 to 1 second.

The present invention will be explained in more detail below with reference to Examples.

Example Polyethylene terephthalate having an intrinsic viscosity of 0.96 was melt-spun from a spinneret with a pore diameter of 0.55% and a number of holes of 120 at a temperature of 300°C, and after cooling and solidifying, a filament to which an oil agent had been added was supplied heated to 97°C. Roller (peripheral speed 66 m)
7mltt) 8 times and 5 times around a stretching roller (peripheral speed 337m/am) heated to 200°C.
．． The contact was held for 21 seconds, and then the take-up roller (peripheral speed 300
m/min) three times, and then wound with a spindle-driven winding machine to 1250 de/120 fil.
A drawn filament was obtained.

At this time, y is 29. O and 21.0 (equivalent/polymer 106P).

Next, each filament was twisted with a first twist of 429T/M, three yarns were combined, and a final twist of 266T/M was applied with a twist of 1250/3.
The fishing net thread A was dyed at 130°C for 60 minutes, and then finished at 160°C for 1 minute under a 2% elongation condition.

This was used as a fishing net by knitting a knotless fishing net and using it at a fishing ground for one year, and the strength and elongation data before and after use are shown in Table 1.

As yet another example, 1000de'150fil
The results of using the drawn filament as fishing net thread are also shown in Table 1.
It is written in .

As a comparative example, polyethylene terephthalate with an intrinsic viscosity of 0.92 was spun using a spinneret with 180 holes under the same conditions as above (y at this time was 44.0).
The yarn was twisted, dyed, finished, knitted, and used for one year, and the strength and elongation data before and after use were measured.

Furthermore, the intrinsic viscosity is 0.97, and the carboxyl group terminal concentration is 20.
．． Polyethylene terephthalate 10007' Neil/250 fi with 0 and 29.0 (equivalent weight/106 g)
1 drawn filament is twisted at 480T/M,
A fishing net consisting of 100/X fishing net line was used, with three yarns plied together and twisted to a 300 T/M.

The strength and elongation before and after use were measured after one year of use.

As another comparative example, polyethylene terephthalate 1000 denier/100 drawn filaments having an intrinsic viscosity of 0.94 and a terminal carboxyl group concentration of 36.0 (equivalent weight/io6 y) were used as a fishing net thread.

The strength and elongation before and after use were measured after one year of use.

Furthermore, 1250de/120fil (y=55.0
), 1000 de/45 fil (y=51
) All results using the drawn filament are shown in the table below.

(In all examples, almost no change in denier was observed before and after use.

) (Concerning the conditions for drying the fishing nets, we adopted a method in which fishing nets were piled up directly on the new concrete and dried in the sun after fishing at the fishing grounds and returning to the port, which had been newly constructed using concrete through land reclamation or other methods. The results of repeated operation and drying for one year are shown.

Claims (1)

[Claims] 1 Single fiber denier is 5 to 30 denier, breaking strength and elongation are 5.5 P/denier or more and 20% or more, respectively,
Single fiber denier X and carboxyl group terminal concentration y (equivalent/
A polyester fishing net yarn characterized in that the polymer (1o6y) is a multifilament that satisfies the following formula.