JPH0826484B2 - Polyamide monofilament - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyamide monofilament having excellent balance of flexibility, tensile breaking strength, tensile breaking elongation and spinning stability.

(Prior Art) Generally, a monofilament is an expression used in comparison with a multifilament. However, not only does it indicate that the number of convergent filaments is singular, but as a common sense among those skilled in the art,
It means a yarn with a relatively thicker wire diameter than a multifilament.

Generally, in the case of a multifilament, flexibility may be required for the purpose of improving drape property and feel of the woven fabric.

On the other hand, in the case of monofilaments, due to the large wire diameter as described above, flexibility is strongly required particularly in many fields such as fishing yarn, rope yarn and cutter cord for mowers. . Usually, the bending hardness of the yarn is proportional to the fourth power of the wire diameter, and therefore, in the case of a very thick monofilament having a particularly large wire diameter, softening has an extremely significant meaning.

As a typical method of the conventionally known monofilament softening technology, Nn
A method of adding a plasticizer typified by butylbenzene / sulfonamide and a method of copolymerizing a polymer that is a monofilament material, for example, in the case of polyamide, a method of copolymerizing nylon 6 with a small proportion of nylon 66. Are known.

However, although the above-mentioned conventional method allows a considerable degree of softening, even if it is applied to a polyamide monofilament, there is a limit to the effect of improving the flexibility, and in reality, sufficient modification has not been achieved yet. Is.

Furthermore, it is known that ε-caprolactam exerts a plasticizing effect on polyamide to some extent, but the degree of softening by that is smaller than the effect by the plasticizer.

(Problems to be solved by the present invention) Therefore, as a result of intensive investigations by the present inventors for the purpose of obtaining a polyamide monofilament having more excellent flexibility than that obtained by the above-mentioned conventional technique, On the other hand, a specific compound, namely ε
-It was found that an effect of improving flexibility can be obtained by adding caprolactam and ethylene bisstearyl amide together in a specific ratio and melt-spinning the same, and previously disclosed Japanese Patent Application No. 60-175645 (Japanese Patent Publication No. -23564).

However, in the above method proposed by the present inventors, for example, the bending hardness, which is a measure of flexibility, is 2.0 Kg.
When trying to obtain the following polyamide monofilament, it is necessary to set the addition amount of ε-caprolactam to a large amount of about 10 parts by weight, so that the properties such as tensile breaking strength and elongation of the monofilament itself must be sacrificed. In addition to not being obtained, there still remains a problem that the spinning stability is hindered, for example, the biting of the raw material into the extruder is reduced.

Therefore, the present inventors continued the study for the purpose of obtaining a polyamide monofilament excellent in flexibility, tensile breaking strength, tensile breaking elongation and spinning stability, as a result, with respect to polyamide which is a monofilament material, When ε-caprolactam and ethylene bisstearylamide are added together, by adding a low molecular weight plasticizer in a specific ratio, not only the flexibility of the monofilament can be further improved, but also the blending amount of ε-caprolactam is higher than before. The present inventors have found that it is possible to obtain a polyamide monofilament in which the tensile breaking strength, the tensile breaking elongation, and the spinning stability are favorably maintained due to the reduction of the polyamide monofilament.

(Means for Solving Problems) That is, the present invention is based on 80 to 96 parts by weight of polyamide, 2 to 10 parts by weight of ε-caprolactam, and 2 to 10 parts by weight of a low molecular weight plasticizer in total of 100 parts by weight, and It is intended to provide a polyamide monofilament, which is obtained by melt spinning a composition to which 0.1 to 0.5 parts by weight of stearylamide is added.

Examples of the polyamide used in the present invention include homopolymers such as nylon 6, nylon 66, nylon 610, nylon 612, nylon 11 and nylon 12, or copolymerized polyamides containing these as the main components.

Ε-caprolactam used in the present invention means nylon 6
Is a raw material for polymerization. [epsilon] -caprolactam remains in the nylon 6 immediately after the polymerization as an unreacted monomer in a considerable amount. Usually, this is subjected to extraction treatment so as to have a residual amount of 0.5% by weight or less and then subjected to melt spinning. When nylon 6 is used in the present invention, such residual unreacted monomer can be used as it is as an additive,
Alternatively, a separately prepared amount of ε-caprolactam may be added and used.

Examples of the low molecular weight plasticizer used in the present invention include N-n-butylbenzenesulfonamide, N-n-butylcyclohexanesulfonamide, N-ethylo-p-toluenesulfonamide, p-toluenesulfonamide, N-cyclohexyl-p. -Toluenesulfonamide, N-n-butyl-
Sulfonamide plasticizers such as p-toluenesulfonamide N-tert-butyl-2-benzothiazolyl sulfenamide and acetic acid-butylbenzenesulfonamide, benzoic acid ester plasticizers such as p-oxybenzoic acid-2-ethylhexyl ester Agent and 2-methyl-2,
Examples thereof include alcohol-based plasticizers such as 4-pentanediol, and among them, sulfonamide-based plasticizers are preferably used.

Next, ethylene bis-stearyl amide used in the present invention is a kind of wax having a melting point of 140 ° C. or higher, and is generally used as an internal smoothing agent or mold release agent in molding plastics represented by polyamide, and a smoothing agent in casting. It is a compound used as an agent, a lubricant in the drawing of iron wire, an anti-blocking agent in an adhesive tape, and the like. It is also known that ethylene-bisstearylamide is added to a synthetic resin monofilament material and melt-spun, but in this case, it is used as a smoothing agent to suppress stains on the spinning nozzle or to utilize the wax performance to perform spinning. The purpose is to suppress the generation of fine crystals during cooling of the spinning yarn and to maintain the transparency of the monofilament. By using this together with ε-caprolactam and a low molecular weight plasticizer, the flexibility of the polyamide monofilament is improved. That technical idea was not known at all.

In order to achieve the object of the present invention by adding the above-mentioned three kinds of additives to polyamide, the mixing ratio of these is 80 to 96 parts by weight of polyamide, 2 to 10 parts by weight of ε-caprolactam and 2 parts of low molecular weight plasticizer. It is necessary to add 0.1 to 0.5 part by weight of ethylene bisstearyl amide to 100 parts by weight of total 10 parts by weight. If the amount of each of ε-caprolactam and the low molecular weight plasticizer is less than 2 parts by weight, the effect of improving the flexibility of the monofilament is poor, and if it exceeds 10 parts by weight, not only the spinning property of the monofilament becomes unstable but also the monofilament becomes unstable. It is not preferable because it impairs other physical properties of itself. On the other hand, if the amount of ethylene bisstearyl amide added is less than 0.1 parts by weight, the effect of improving the flexibility of the monofilament is poor, and if it exceeds 0.5 parts by weight, the wax effect becomes too strong and the pushability of the raw material into the spinning extruder screw becomes unstable. Is not preferable.

In the above, with respect to a total of 100 parts by weight of 84 to 94 parts by weight of polyamide, 3 to 8 parts by weight of ε-caprolactam and 3 to 8 parts by weight of a low molecular weight plasticizer, the mixing ratio of 0.2 to 0.5 parts by weight of ethylene bisstearyl amide is It is more preferable.

The addition of ε-caprolactam, a low molecular weight plasticizer and ethylene / bisstearylamide to polyamide is performed by a dry blending method, and ε-caprolactam and a low molecular weight plasticizer are added to chips obtained by adding ethylene / bisstearylamide during the polymerization of polyamide. How to dry blend,
Examples thereof include a method of mixing a master chip to which a large amount of an additive is added and a polyamide chip, and a method of adding the additive from a vent of an extrusion spinning machine.

As the melt spinning method of the above polyamide composition, a usual polyamide monofilament spinning means, for example, a melt spun yarn is introduced into a cooling bath to be cooled and solidified, and subsequently introduced into a drawing atmosphere such as hot water or heated air, A method of stretching to a desired stretching ratio can be adopted.

The thus obtained polyamide monofilament of the present invention has excellent tensile strength at break, tensile elongation at break, and yarn-forming stability together with excellent flexibility not conventionally obtained, and is used as a raw yarn for fishing and a raw yarn for ropes. And it is expected to be applied to various fields such as cutter cords for mowers.

The effects of the present invention will be described in more detail below with reference to examples.

(Example) Nylon 6 having a relative viscosity of 4.2 measured with 98% concentrated sulfuric acid as a solvent was dry-blended with various kinds of additives, combinations and addition amounts thereof as shown in the table. Each of them was melt-spun at a temperature of 260 ° C., cooled and solidified in a cooling water bath of 20 ° C., and subsequently stretched 4 times in a hot water bath of 95 ° C. to obtain drawn monofilaments each having a diameter of 2 mm.

The results of evaluating the bending hardness, the tensile breaking strength, the tensile breaking elongation, and the spinning stability of each of the obtained monofilaments are also shown in the table.

 Each property was evaluated according to the following methods.

"Bending hardness" On two stainless steel rods with a diameter of 5 mm placed in parallel with an interval of 30 mm, the object to be measured (monofilament) is placed in the direction perpendicular to them, and a hook with a diameter of 5 mm is placed in the center thereof. It was expressed by the maximum stress (Kg) when vertically pulling out between two stainless steel bars by multiplying. The pulling speed for moving the hook was 50 mm / min, and the atmospheric conditions during measurement were set to 20 ° C. and 65% RH. The monofilament to be measured was left for 24 hours or more in the atmosphere of 20 ° C. and 65% RH in advance and then used for the measurement.

"Tensile breaking strength and tensile breaking elongation" Measured according to JIS L-1013.

"Spinning Stability" The state during the connection melt spinning under the above conditions was observed and evaluated according to the following three criteria.

○ …… Good △ …… Slightly unstable pushing of raw material × …… Unstable pushing of raw material As is clear from the results in the table, the bending hardness of the polyamide monofilaments (9 to 15) of the present invention is significantly reduced,
Due to the synergistic action of the three kinds of additives, the flexibility is dramatically improved, and the tensile breaking strength, the tensile breaking elongation and the spinning stability are well maintained.

On the other hand, when only one kind of each additive is added (No.2 to 6), the effect of improving flexibility is not obtained in any case, and when two kinds are used in combination (No.7, 8 and 16). Has some flexibility but is still insufficient.

Even if three additives are used in combination, if the amount of ε-caprolactam or the low molecular weight plasticizer added is too large (No. 18
And 19) shows that not only the pushing of the raw material into the spun fabric becomes unstable, but also other target properties tend to deteriorate.
On the contrary, when the addition amount of ε-caprolactam or the low molecular weight plasticizer is small (Nos. 20 and 21), the softening effect is unsatisfactory. Similarly, even if three additives are used together, if the amount of ethylene bisstearylamide added is too large (No. 17), the pushing of the raw material into the spinning machine becomes unstable, and the spinning becomes impossible.

(Effects of the Invention) As described above, the polyamide monofilament of the present invention has excellent flexibility that has not been conventionally obtained,
It has good tensile strength at break, tensile elongation at break and yarn stability, and is expected to be applied to various fields such as raw yarn for fishing, raw yarn for ropes and cutter cords for mowers.

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Claims (1)

[Claims] 1. An ethylene bisstearyl amide based on 100 parts by weight of 80 to 96 parts by weight of polyamide, 2 to 10 parts by weight of ε-caprolactam and 2 to 10 parts by weight of a low molecular weight plasticizer.
A polyamide monofilament, which is obtained by melt spinning a composition to which 0.1 to 0.5 parts by weight is added.