JPS5994616A - Polybutylene terephthalate monofilament - Google Patents

Abstract

PURPOSE:To obtain a polybutylene terephthalate (PBT) monofilament having specific intrinsic viscosity and specific birefringence, and excellent tensile strength and knot strength, and applicable to a fishery material, fastener, etc., by using a specific PBT polymer as the raw material. CONSTITUTION:A PBT polymer containing 3-30wt%, preferably 3-25wt% of a poly(branched alkylene) terephthalate component (e.g. polyneopentyl terephthalate) as a copolymerized or mixed component, is subjected to melt spinning, cooling, and thermal drawing until the birefringence reaches >=0.15 to obtain the objective PBT monofilament having an intrinsic viscosity of >=1.1.

Description

Detailed Description of the Invention: Polybutylene terephthalate (copolymerized or mixed with
Hereinafter referred to as PUT. ) type polymer with excellent tensile strength and knot strength.

Nylon has traditionally been the material for monofilament.

Polyethylene terephthalate 1- (hereinafter referred to as PI (T).

) is generally known.

In particular, nylon monofilament has excellent tensile strength and knot strength, and is most commonly used in commercial materials such as fishing nets and lines. however.

Bouillon monofilament is also a material that has a property of significantly decreasing strength due to insufficient weather resistance and water absorption.

On the other hand, PET has relatively excellent resistance to aging and extremely low water absorption, making it less susceptible to strength loss due to water absorption, but monofilament made of PET has an extremely high bending rigidity.

It is unsuitable as a fishing material, and is only used for fishing lines in a limited number of applications.Therefore, a material that does not have the drawbacks of nylon and PET mentioned above and has satisfactory properties in terms of weather resistance, water absorption, and bending rigidity. Using PBT as a material,
Several proposals have been made to form monofilaments.

For example, a method is used in which the melt is cooled in a hot water bath and then stretched in two stages with a limited stretching ratio to increase the knot strength (Japanese Patent Laid-Open No. 51-156
9197, a method of limiting shrinkage or tension heat treatment after two-stage stretching (Japanese Patent Application Laid-Open No. 123316/1982), PBT monofilament with limited density and birefringence (Japanese Patent Application Laid-Open No. 49-6691)
6-1! -) etc.

However, fishing materials such as fishing nets and fishing lines are required to have particularly high knot strength characteristics, but the knot strength of the monofilament obtained by the above method is at most 3.5 Q/d, which is not suitable for practical use. .

The present inventors have conducted intensive studies to improve the strength characteristics of PBT, which has properties that nylon and PET do not have, and as a result, they have arrived at the present invention.

That is, 9 the present invention is a PET fiber-combined fiber body copolymerized or mixed with a polybranched alkylene terephthalate component in an amount of 6 to 60%, and has an intrinsic viscosity of 1.1 or more and a bi/lli fold of 0.15 or more. The gist is a PBT monofilament having the following characteristics.

The branched alkylene glycol of the polybranched alkylene terephthalate component in the present invention includes:

2-Methyl-propanediol-1,5, neopentyl glycol (2,2-dimethyl-propanediol-4
,3),2-methyl-butanedimer-1,4,2,2
-Dimethylbutanediol--Nityl-octatecanediol-1.18, etc., but neopentyl glycol is preferred because it is available at a low cost.

The appropriate amount of the polybranched alkylene terephthalate component in the PBT polymer is 3 to 30% by weight, preferably 3 to 25% by weight. If this amount is less than 6% by weight, the effect of improving the strength of the nodule portion will not be sufficient, and if it exceeds 60% by weight, a monofilament with sufficient strength will not be obtained.

Further, the monofilament of the present invention needs to have an intrinsic viscosity of 1.1 or more. In general, increasing the intrinsic viscosity improves strength performance, but in the case of PBT homopolymers, increasing the intrinsic viscosity causes the resulting monofilament to become cloudy and reduce knot strength. However, the PBT polymer containing the polybranched alkylene terephthalate component of the present invention does not have this problem, and by increasing the intrinsic viscosity, a transparent monofilament with dramatically improved knot strength was obtained. It is. However, if the intrinsic viscosity is increased too much, the melting temperature during spinning must be increased and the decomposition reaction becomes more intense, so the intrinsic viscosity is preferably 1.6 or less.

Furthermore, it is necessary for the monofilament of the present invention to have a birefringence of 0.15 or more; if it is less than 0.15, the stretching orientation is insufficient, resulting in low bow 1 tensile strength and low knot strength.

In addition, although transparency is required as a necessary characteristic for fishing materials, according to the present invention, by satisfying the six requirements of polymer composition, intrinsic viscosity, and birefringence, it has excellent strength characteristics. Additionally, a monofilament having a transparency of 1% jt can be obtained.
Other polyester components, especially PE
A small amount of the T component may be copolymerized or mixed, and the total amount of the polybranched alkylene terephthalate component is 3 to 30%.
%, when the PBT component is contained in an amount of 70% by weight or more, a monofilament 1 with superior performance can be obtained.

The monofilament of the present invention is preferably manufactured by the following method, whereby a high-strength monofilament can be easily obtained.

That is, the PBT polymer [poly(butylene terephthalate/branched alkylene terephthalate) copolymer or a mixture of polybutylene terephthalate and polybranched alkylene terephthalate] is melt-extruded using a melt extruder. After melt spinning and cooling.

(1, 1) Hot-stretched until it shows 5 or more folds.

The monofilament of the present invention has a soaked strength characteristic and can be fully applied not only as fishing materials such as fishing nets and fishing lines, but also for other uses such as zippers, canvases, pouches, etc. It is.

The present invention will be explained in more detail below using examples.

In the examples, the intrinsic viscosity [η] is a value measured at a temperature of 30°C using an equal weight mixture of phenol and tetrachloroethane as a solvent, and the birefringence is a value measured using a polarized I11ii microphotograph after cutting a monofilament into a wedge shape. This is the value obtained from the interference image of .

Examples 1-4. Comparative Example 1 Intrinsic viscosity [η] = 4.25 from terephthalic acid, 1,4-butanediol and neopentyl glycol by a conventional method
A random copolymer chip of PBi'/polyneopentyl terephthalate (composition weight ratio: PB'l'/polyneopentyl terephthalate = 85/15) was synthesized,
After drying for 24 hours in a nitrogen stream at 13[]'C, 26
It was melted using an extruder set at 0°C, extruded into a water bath at 30°C, and rapidly cooled. Then in a hot water bath at 80°C
．． It was stretched to 8 times, and then further stretched in an air bath at 450°C to a total stretching ratio of 6 and 0. 6,5. 7.0. A second stage of stretching was performed so that the film was stretched 7.5 times. Heat death f during first stage stretching
11i is approximately 1 second, and the heat treatment time during the second stage stretching is 0.
It was 4-05 seconds.

As a result of comparing the physical properties of the drawn monofilaments obtained,
It was as shown in Table 1.

For comparison, the same operation as in Example 1 was performed except that the total stretching ratio of the unstretched product was increased to 4.0 times, and the results are also shown in Table 1.

Table 1 As a result, the birefringence becomes thicker (otherwise, not only the nodule strength but also
It is clear that the tensile strength is also lower.

To make the birefringence 0.15 or more, the total stretching ratio should be 7.
- The material must be fully stretched and oriented.

Examples 5-6. Comparative Example 2 PBT copolymers having the same composition as in Examples 1 to 4 and having intrinsic viscosities of 1.15 and 1.40 were used, and spinning and stretching were performed using the same apparatus as in Examples 1 to 4. The spinning and drawing conditions at this time are shown in Table 2, and the physical properties of the obtained monofilament are shown in Table 5. For comparison, P with the same composition as Examples 1 to 6
Table 6 shows the conditions when using a BT copolymer with an intrinsic viscosity of 1.00.

The physical property values of the monofilament are also listed in Table 4.

Table 2 Table 6 From the results, it is clear that as the intrinsic viscosity increases, both the tensile strength and knot strength improve.

Examples 7-9. Comparative Examples 3 to 4 pBT copolymers having different copolymerization ratios of polyneopentyl terephthalate were molded into monofilaments in the same manner as in Examples 1 to 6. -1 (polymerization ratio and monofilament spinning and drawing conditions are shown in Table 4, and physical property values of the monofilament are shown in Table 5).

Table 4 Table 5 From these results, it is clear that when the copolymerization ratio of polyneopentyl terephthalate deviates from the range of the present invention, the strength performance of the monofilament decreases. Furthermore, PBT
In the case of a homopolymer, whitening was significant and it was unsuitable for use as a fishing line.

Examples 10-11. Comparative Example 5 A blend of PBT twig having an intrinsic viscosity of 1.50 and borine mepentyl terephthalate chips having a relative viscosity of 1.54, and this blended chip having an intrinsic viscosity of 1.020.
Additional PET chips were blended to form a monofilament. The conditions at this time are shown in Table 6, and the physical property values of the monofilament are shown in Table 7.

For comparison, PET with an intrinsic viscosity of 1.02 was compared to PET with an intrinsic viscosity of 1.
Spinning when blending 3(+17) PBT chips.

Stretching conditions and physical property values are also listed in Tables 6 and 7.

Table 6 Table 7 From the results, it is clear that even when a chip blend is used as the PBT polymer, good performance is exhibited.

In addition, according to Comparative Example 5, in the composition obtained by blending PET with PBT, polybranched alkylene terephthalate L
/- Because it does not have a component, it does not show any improvement in knot strength, and the smooth monofilament car becomes cloudy.

It turns out that it is not possible to obtain a monofilament with the desired performance.

Patent applicant: Unitika Co., Ltd.

Claims (1)

[Claims] 1 polyalkylene terephthalate component is 5 to 50%
jlj jft, % co-electric or mixed polyglylene
A polybutylene terephthalate monofilament, which is made of a polybutylene/Fukray] type polymer and has an intrinsic viscosity of 1.1 or more and a birefringence of 0.15 or more. 2. The monofilament according to claim 1, wherein the polyalkylene terephthalate is polyneopentyl terephthalate.