JPS6012460B2 - Aromatic polyamide composite yarn - Google Patents

Description

[Detailed Description of the Invention] Compared to conventional organic fibers, aromatic polyamide fibers have
It has excellent heat resistance and chemical resistance, as well as high tensile strength and high modulus close to that of steel wire. In actual use, there are undesirable phenomena such as elongation due to untwisting, fuzzing due to friction, and a decrease in strength due to knots.

As a means to prevent this and to improve water resistance, a method has conventionally been adopted in which an aggregate of doubled or lacquered threads is impregnated with resin and fixed by heating.

In this conventional side resin impregnation method, in order to ensure water repellency, a relatively low viscosity resin solution is applied and impregnated so as to completely cover the yarn surface so that no part of it is exposed. It fills the spaces between the twisted fibers, fixing them together and significantly increasing rigidity. Increased stiffness is an undesirable property depending on the use of the filament. On the other hand, if the amount of coated resin is limited in order to avoid an increase in rigidity, the hydrophilic nature of the filament remains, and fluffing is likely to occur due to friction. The present invention aims to improve the above-mentioned drawbacks.The core body made of aromatic polyamide threads is twisted to a specific coefficient or less, and the surface of the core body is coated with polyamide resin extremely thinly, uniformly, and continuously. As a result, we succeeded in improving abrasion resistance and water repellency, as well as increasing knot strength, while maintaining the degree of freedom of the individual aromatic polyamide yarns assembled or twisted together. This is what I did.

The aromatic polyamide yarn or twisted yarn in the present invention has the general formula (where n is a positive integer).

) The organic polymer compound (polyparaphenylene terephthalamide) represented by Table 1 shows the comparison with yarn.

As shown in Table 1, the tensile strength of aromatic polyamide yarn is more than twice that of nylon yarn or polyester yarn, and 1.2 times stronger than that of glass yarn.

In addition, the elongation is about 1'2 for glass yarn and less than 1'5 for nylon yarn and polyester yarn.The core of the aromatic polyamide composite yarn of the present invention has a general formula (however, n
is a positive integer.

) Polyparaphenylene terephthalamide represented by ★ paper yarn is prepared by arranging two or more threads of doubling or burning thread to form the general formula K (
Twist coefficient) = n (number of twists per thread) x ′○(
Twist coefficient (K) defined by denier value) 2870 is 6
It is twisted as shown below.

Generally, there is a specific relationship between the tensile strength or elongation of twisted yarn and the twist coefficient.

In the case of aromatic polyamide yarn, the relationship between its twist coefficient and tensile strength is shown in Figure 1. Also,
The relationship between twist coefficient and elongation at break is shown in Figure 2.
As can be seen from Figure 1, in the core of aromatic polyamide composite yarn, the tensile strength is maximum when the twist coefficient is 1. Decrease.

On the other hand, as shown in FIG. 2, the relationship between twist coefficient and elongation at break is such that as the twist coefficient increases, elongation increases. Therefore, in order to keep the tensile strength, which is a feature of the core of aromatic polyamide composite yarn, as high as possible and to keep the elongation as small as possible, the twist coefficient (K) must be 6 or less, preferably 2.5 or less. Must be.

In the present invention, when the twist coefficient (K) exceeds 6, the tensile strength decreases, the elongation rate increases, and the desired effect cannot be obtained.

The surface of the core of the aromatic polyamide composite yarn of the present invention is provided with a thin continuous coating of polyamide resin, polyamide copolymer resin, or mixed resin containing these.

Here, polyamide resin is a linear synthetic polymer made of a large number of alkylene groups bonded with amide groups, and is typified by nylon, including nylon 6, nylon 6-6, nylon 6-10, and nylon 11. , nylon 12, etc. are exemplified.

In addition, polyamide copolymer resins include, for example, {NH(CH
2) 5CO} and {NH (C ratio) 6NHC○ (C ratio) 4C
copolymerized nylon with O}. The core of the aromatic polyamide composite yarn is coated with a polyamide resin using a solvent such as lower alcohol, phenol, lower alcohol saturated with calcium chloride, ethylene glycol, benzyl alcohol, etc.A solvent-based coating of polyamide resin is applied to the aromatic polyamide core. It can be applied by applying it to the surface of the body and then removing the solvent by drying, evaporation, etc. It can also be easily applied by melt extrusion coating using an extruder or other known coating methods.

The present invention provides a thin and continuous coating of polyamide resin on the entire surface of the core of an aromatic polyamide composite yarn, thereby achieving low abrasion resistance and a decrease in strength at knotting, which are considered to be disadvantages of aromatic polyamide yarns. It has a remarkable effect on improving.

For example, when 200 denier x 2 x 3 twisted yarns were compared between nylon yarn, polyester yarn to aromatic polyamide yarn, and the aromatic polyamide yarn having a resin coating of the present invention, the results shown in Table 2 were obtained.

Table 2 In the aromatic polyamide composite yarn of the present invention, the type of resin and coating thickness can be arbitrarily selected depending on the degree of abrasion resistance required and the increase in film resistance. If high properties are not required, a coating thickness on the 0.05 side is sufficient.

In addition, if extremely high wear resistance is required, 0.3
It is possible to meet that requirement by applying a yield coating, and the response is quite arbitrary. The composite yarn of the present invention can be widely used in wire ropes, cable tension materials, structural materials for airplanes and car bran, structural materials for ship hulls, bulletproof materials, fishing rods, racket guts, and the like.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the draw strength and twist coefficient of aromatic polyamide yarn, and FIG. 2 is a diagram showing the relationship between elongation and twist coefficient of aromatic polyamide yarn. Porridge diagram 2

Claims (1)

[Scope of Claims] 1. An aromatic polyamide composite yarn in which a thin resin coating layer is provided on the surface of a core body made by twisting together a plurality of aromatic polyamide doubled or twisted yarns, wherein the core body has the general formula K ( The twist coefficient K defined as (twist coefficient) = (n (number of twists per 1 m) × √ (D (denier value))) / 2870 is 6
An aromatic polyamide composite yarn which is twisted as follows, and the material of the resin coating layer is a polyamide resin, a polyamide copolymer resin, or a mixed resin containing at least one of these resins.