JPS61124622A - Monofilament of nylon 46 - Google Patents

Abstract

PURPOSE:The titled monofilament that has specific tensile strength, knot strength, elongation at break, thermal shrinkage and melting point, simultaneously, further shows high dimensional stability and heat resistance, therefore, it is suitably used as ropes, fish nets, fishing lines, etc. CONSTITUTION:The objective monofilament has following properties at the same time: tensile strength (dry), 7.5-15.0g/d; knot strength, higher than 4.0g/d; elongation at break, 10.0-30.0%; dry heat shrinkage, less than 10.0%; melting point, 280-310 deg.C; monofilament denier, higher than 50d, preferably higher than 100d. The wet tensile strength is preferably 6.0-15.0g/d.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyamide monofilament that has excellent dimensional stability and excellent heat resistance.

More specifically, the applications include general ropes and fishing nets.

This relates to monofilament used in fishing lines and the like.

(Prior Art) Polyamide monofilaments are utilized for fishing lines, fishing nets, and the like because of their characteristics such as toughness, transparency, and flexibility. When used in these applications, monofilaments often generate heat due to friction with rocks, etc., causing fibrillation and fusing. In addition, monofilaments are often exposed to sunlight, but if left unattended, the monofilament expands and contracts due to an increase in ambient temperature, and there are cases where the monofilament becomes unusable.

Also, as for the monofilament strength when wet.

Although polyamide is superior to other materials, it is desired that the current polyamide, which is mainly made of nylon 6 or nylon 66, has even higher wet strength retention.

Polytetramethylene adipamide (nylon 46) is 30
For more than a year (e.g. J, Polymer Scf,
+ 3?609C1948) is a known polyamide, solid phase polymerization is carried out under high temperature dry nitrogen, vacuum or steam (it is believed that it is also known from the example of nylon 66 that it becomes a higher molecular weight polymer). It will be done.

In JP-A-56-149431, a method for producing high molecular weight nylon 46 is proposed. Despite this early knowledge, nylon 46 has a high melting point of approximately 290°C, and is expected to deteriorate during melting (mainly a decrease in molecular weight), making molding difficult. This is probably one of the reasons why it has not been put into practical use. The only proposal is JP-A-1983-1. However, the potential as a plastic is limited to that given in No. 149429.

The difficulty in melt molding nylon 46 is most noticeable when it is made into fibers.

Decrease in molecular weight can be minimized by shortening the residence time during melting in a melt extruder, but it is difficult to draw the undrawn yarn spun in a conventional manner. However, it is not possible to obtain fibers with higher strength.

(Problems to be Solved by the Invention) Conventional monofilaments that have been put to practical use include polyamide monofilaments such as nylon 6 and nylon 66, polyethylene terephthalate, polybutylene terephthalate, polyvinylidene fluoride, high-density polyethylene, polypropylene, etc. However, it has not been possible to put into practical use a monofilament that is excellent in heat resistance, dimensional stability, and wet strength retention as intended by the present invention.

(Means for Solving the Problems) Means for solving the above problems, that is, 1 configuration of the present invention is a nylon 46 monomer characterized by having the following characteristics (a) to (f) at the same time. Ifment.

(a) Tensile strength (dry) 7.5 to 15.0 (g/d
) (b) Nodule strength 4.0 or more (g/
d) (c) Elongation at break 1060-30.0
(%) (d) Dry heat shrinkage rate 10.0 or less (high) (e) Melting point 280
~310 (℃) (to) Monofilament Denny I
v 50 or more (d) The present invention is achieved by the method shown below. That is.

(1) M! A polyamide polymer consisting essentially of polytetramethylene adipamide, which has 90 moIv% or more of detramethylene adipamide as a 7-turn unit and has a high degree of polymerization with a relative viscosity of 2.7 or more, has a moisture content of After drying to 0.4% or less, it is melted at a temperature range of 270°C or higher and 320°C or lower, and spun through a spinneret nozzle. ~
5QQ[, After passing through a heating cylinder filled with an inert gas (for example, N2.Ar) having an internal air temperature of 200 to 350°C, it is rapidly cooled in a cold water bath.

(3) Continue to heat the taken yarn at 70 to 120°C.
Stretched at a ratio of 70% or more of the total stretching ratio in a hot water bath of 1
Then, the film is stretched in a non-contact heater at 120 to 200°C, preferably a steam heater within 15%, and more preferably subsequently stretched in a non-contact heater at 150 to 250°C, preferably a hot air heater. rear.

Perform relaxation treatment within 10% in warm water.

Accordingly, the monofilament of the present invention is obtained.

The monofilament of the present invention thus obtained has the following properties (a) to (f).

(a) Tensile strength (dry) 7.5 to 15.0 (g/d
) (b) Nodule strength 4.0 or more (g/
d) (c) Breaking elongation 10.0 to 30.0 (
%) (d) Dry heat shrinkage rate 10.0 or more
Lower (C) (E) Melting point 280~
310 (℃) (to) Monofilament Denny/I
/50 or more, preferably 100 or more (d) Furthermore, the monofilament of the present invention has a wet tensile strength of 6.0 to 15. It has also been found that it has the characteristic of having Of/d.

If the tensile strength of the monofilament of the present invention is less than 7.5 f/d, the strength after being twisted into a rope or the like will be inferior to that of a conventional polyamide monofilament. It becomes difficult to take advantage of the desired characteristics of the monofilament. Furthermore, when the tensile strength of the monofilament exceeds 15 f/dt, the orientation of the molecular chains increases significantly and the monofilament becomes rigid.

Passability through post-processing steps decreases. Furthermore, the nodule strength is 4, O
If it is less than f/d, the actual durability when used for fishing lines etc. will be significantly reduced.

On the other hand, if the elongation at break is less than 10, the strength retention rate during twisting or loop formation will be severely reduced. If the elongation at break exceeds 30%, the creep properties will be significantly reduced, resulting in reduced suitability for industrial uses. 1+, dry heat shrinkage rate is 10
If it exceeds 1%, the dimensional stability of the monofilament decreases in an atmosphere such as when left in a car interior under sunlight irradiation.

It becomes difficult to apply it to uses such as fishing lines.

The nylon 46 monofilament in the present invention has tetramethyleneazibaritetramethylV as a repeating unit.
-Adivamide is a copolymer of a third component such as #-capramide component and hexamethylene adipamide component in a ratio of less than t-107 & or poly! -1 ie.

This means that it includes a blend of poly ξ-capfumide and polyhexamethylene adipamide at a ratio of less than 10%.

Here, it is preferable to copolymerize the third component or to blend a polymer made of these components from the viewpoint of improving the spinning stability.

High melting point and maximum temperature of crystallization rate of 275℃
When melt-spinning nylon 46, it is necessary to maintain the temperature of the heating cylinder near the thermal decomposition temperature of nylon 46 and to suppress thermal decomposition in order to control the thinning pattern of the spun yarn. Although this was the biggest bottleneck in fiberizing nylon 46 high-strength yarn, the present inventors discovered that filling a specific length of the heating cylinder with an inert gas made it possible to stably fiberize it.

The length of the heating cylinder directly below the cap is 500mm. If it exceeds 2, resonance is likely to occur, and the distance to the quenching water tank and the air gap length need to be very long, making it impractical.

On the other hand, when the heating cylinder length is 20111 mm or less, there is almost no effect of controlling the thinning pattern of the spun yarn necessary for stabilizing the spun part.

When the internal air temperature exceeds 350'Ct-, thread breakage occurs frequently even if the heating cylinder is filled with inert gas.

On the other hand, if the internal air temperature is less than 200° C., the effect of retarding yarn thinning is diminished.

If the relative viscosity of sulfuric acid is less than 2.7, it is difficult to increase the tensile strength of the drawn yarn to 7.59/d or more.

Deny p of the polyamide monofilament of the present invention is 50
It is preferable to have a denier of 1 denier or more, and in particular, a thick denier of 100 denier or more is preferable in consideration of labor saving in the case of secondary processing.

The polyamide monofilament of the present invention has high strength, transparency, gloss, and excellent flexibility when made into secondary processed products such as ropes.

(Example) The present invention will be explained in detail with reference to Examples below, and the measuring method used for evaluation of the present invention is as follows.

[Filament strength and elongation measurement method]

According to JIS-L1013. However, the chuck distance is 30
The temperature and humidity conditions were cfIM, a tensile rate of 30/min, 20° C., and 60% RH.

[Measurement method of relative viscosity]

Prepare a sample solution by dissolving the sample in 96.3 ± 0.1 wt% reagent special grade concentrated sulfuric acid so that the polymer concentration is 10 kg/yxl, and drop it on ice at a temperature of 20 °C ± 0.05 °C. Measure the relative viscosity of the solution using an Ostwald viscometer with 6-7 seconds. During the measurement, the same viscometer was used, and the same falling time To (seconds) of sulfuric acid 20111t as when preparing the sample solution and falling time T of the sample μ solution 20xtlO were used.
t@) (D Relative viscosity Rv is calculated using the following formula.

RV=T+/T.

[Measurement method of dry heat shrinkage rate SHD]

After placing the sample in a case and leaving it in a temperature and humidity controlled room at 20°C and 65% RH for more than 24 hours, the sample length Jo was measured by applying a load corresponding to 0, if/d of the sample. After leaving it in the open at 150°C under tension for 30 minutes, take it out from the open and leave it in the humidity control room mentioned above for 4 hours, then apply the above load again and measure the length! 1 by the following formula.

G [Melting Point] The melting point refers to the temperature at the peak of the melting endothermic curve measured by the DSC measurement method. Naori SC measurement method is Shimazu Diffe
Rental Scanning Calorime
The test was carried out using TER 5C-20 at a heating rate of 20° C./i.

[Sedimentation velocity]

Using the sedimentation rate measuring device shown in FIG. 1, the sedimentation property t of the sample filament was evaluated.

1. Fill the glass cylindrical tank shown in FIG. 1 with water.

Adjust to 20°C.

The sample filament is cut into two lengths, immersed in water at 20° C. to 5° C. for 12 hours or more, and thoroughly deflated. The sample after the immersion treatment is allowed to settle from the water surface 2 at an initial velocity O, and the passing time of passing through the middle of the water between the reference line A-Bt - the starting point and the reference line C-Dt - the ending point is measured.
/ expressed as m.

Example 1 Nylon 46 polymer t-25jmφ with relative viscosity 3.4
Melt extruded using an extruder, mouth hole diameter 0.8j111φ
The nozzle pushed it out.

Next, 300301.300°C was installed directly below the nozzle.

It was passed through an air gap of 5 cm from the heating tube where the N2 barge was applied, and then rapidly cooled in water at 5°C, and then continuously stretched 4.3 times in a hot air heater at 110°C. After this.

Relaxation treatment was performed for 9 times in steam at 180°C.

Furthermore, it was stretched 1.2 times in hot air at 200°C, and subjected to a 7% relaxation treatment in hot water at 90°C. The properties of the obtained monofilament are shown in Table 1.

For comparison, the characteristics of commercially available nylon 6 strings were
Also listed in the table.

As is clear from Table 1, the monofimment of the present invention has far superior dimensional stability and heat resistance compared to commercially available nylon 6 wires, and has excellent dimensional stability and heat resistance, which is a very important factor for fishing lines, etc. It is clear that the speed is more than twice that of commercially available nylon 6 yarn, and that it has a high strength retention rate when wet, which is important as a marine material.

Table 1 Comparative Example 1゜ Silk production was attempted under the same spinning and drawing conditions as in Example 1 except that no N2 purge was applied to the heating cylinder directly below the nozzle, but yarn breakage occurred frequently and fiberization occurred. could not.

(Effects of the Invention) The polyamide monofilament of the present invention has the highest heat resistance among the organic material monofilaments produced by the melt spinning method that are currently in practical use as monofilaments, so it is inexpensive and has excellent dimensional stability and durability. We can provide monofilament.

Further, since the strength retention rate when wet is higher than that of conventional polyamide monofilament, K is particularly suitable for fibers for marine materials, such as fishing lines, fishing nets, and ropes for large ships (hawsers, tug ropes, etc.).

Furthermore, since the monofilament of the present invention has a specific gravity of 1.17, which is violet compared to 1.13 K of conventional polyamide monofilament, it has a fast settling speed and is very suitable as a fishing line.

It goes without saying that the monofilament of the present invention is suitable for use in all fields other than those described above, which require performance such as heat resistance, one-dimensional stability, and high wet strength retention.

[Brief explanation of drawings]

FIG. 1 is a model diagram of a sedimentation rate measuring device. 1...Glass cylindrical tank 2...Water surface

Claims (1)

[Scope of Claims] 1. A nylon 46 monofilament characterized by having the following properties (a) to (f) at the same time. (a) Tensile strength (dry) 7.5 to 15.0 (g/d) (
b) Knot strength 4.0 or more (g/d) (c) Breaking elongation 10.0 to 30.0 (%) (d) Dry heat shrinkage rate 10.0 or less (%) (e) Melting point 280 to 310 (°C) (f) The nylon 46 monofilament according to claim 1, wherein the monofilament denier is 50 or more (d) 2, and the monofilament denier is 100 or more denier. 3. Nylon 46 according to claim 1 or 2, which has a tensile strength (when wet) of 6.0 to 15.0 g/d.
series monofilament.