JP3434012B2 - High strength and high elongation polyester fiber for industrial materials - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a toughness required mainly for industrial material applications, particularly applications requiring high strength and high elongation, and is excellent in bending wear resistance and bending fatigue resistance. The present invention relates to fibers, particularly polyester-based high toughness fibers.

[0002]

2. Description of the Related Art Polyester fiber typified by polyethylene terephthalate has characteristics of high strength, high Young's modulus and excellent dimensional stability due to its high crystallinity, and is widely used not only for clothing but also for industrial materials. It is used. For example, for tire cord applications, the dry strength is 8 to 9 g / d,
High tenacity and low shrinkage yarns having a dry elongation of 10 to 15% and a Young's modulus of 100 to 120 are generally used. On the other hand, in fields requiring high strength and high elongation such as fishing nets and curing mesh (mesh cloth for construction), dry strength of 8-9g / d and dry elongation of about 20%
(Toughness = 180) or high toughness yarn having a dry strength of 7 g / d and a dry elongation = 25% (toughness = 175) is used. Furthermore, when trying to make a high elongation yarn of more than 30% from a polyester polymer, it is difficult to achieve both high strength and high elongation simply by increasing the degree of polymerization, and the high elongation due to the high crystallinity of the polyester itself. Has not been examined much.

Polyester yarns having an elongation of 40 to 80% can be obtained by a yarn-forming technique applying a recent high-speed spinning technique, but the strength is as low as 3 to 4 g / d, and it is used as a fiber for industrial materials. No polyester yarn for industrial materials having high strength and high elongation was available. Therefore, the fields requiring high elongation and high toughness are mainly
A relatively expensive polyamide was used. However, polyamide has problems that it has high shrinkability and lacks dimensional stability, that it exhibits a large decrease in strength when wet, and that nylon 6 in particular has a low melting point and lacks heat resistance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to use a relatively inexpensive polyester polymer, which has high strength, high elongation and high toughness, and is excellent in bending wear resistance and bending fatigue resistance. To provide the fiber.

[0005]

The present invention comprises a polyester having an ethylene terephthalate unit as a main repeating unit and an intrinsic viscosity [η] of 0.90 or more and 1.01 or less , and an average particle diameter of 0.002 μm in a fiber. 0.50μ or more
0.02 wt% or more and 5.0 wt% or less of solid fine particles of m or less
Contains below, and has a dry strength of 5 g / d or more and 7.33 g / d or less
Lower, InuiShindo is Ri der 30% to 60%, toughness T represented by the following following formula (1) is 250 or more 292 or less,
And at least a compound represented by the following general formula (I)
Contains 1.0% by weight or more and 5.0% by weight or less,
Characteristic that bending wear (K number) is more than 1300 times
And polyester fiber . T = dry strength (g / d) × InuiShindo (%) (1) The glass transition point represented by the following general formula (I) (T
g) 1.0% by weight or more of at least one depressant,
Containing 0% by weight or less, bending wear resistance (number of times K) is 1300
As described above, the strong retention rate (L) represented by the following formula (2) is 40.
%, Especially high toughness polyester fiber of 50% or more. L = (S ₁ / S ₀ ) × 100 (where S ₀ = strength value before flex fatigue test, S ₁ = strength value after flex fatigue test 250,000 times) R1-O−X−O− R2 (I) (wherein X is an aromatic group, R1 and R2 are each a carbon number of 6 to 18)
Represents an alkyl group or an arylalkyl group. )

The polyester used in the present invention is a polyester having an ethylene terephthalate unit as a main repeating unit, and a third component may be copolymerized, but it is a homopolyester containing no third component to be copolymerized. Is desirable. Furthermore, its intrinsic viscosity [η]
Is required to be 0.90 or more. When [η] is less than 0.90, it is difficult to achieve both high strength and high elongation, which are the objectives of the present invention.

The solid fine particles used in the present invention preferably have an average particle size of 0.002 μm or more and 0.50 μm or less, and more preferably 0.02 to 0.05 μm.
If the average particle size is less than 0.002 μm, the particles are agglomerated to form coarse particles, which is not preferable, and if it exceeds 0.50 μm, the effect of increasing elongation is lost, which is not preferable. The content of solid fine particles is 0.02
% To 5.0% by weight, preferably 0.1% by weight
It is preferably not less than 1.0% by weight. When it is less than 0.02% by weight, the effect of increasing the elongation by kneading the fine particles is poorly expressed, and when a Tg depressant is used, good spinnability is not expressed due to a synergistic effect with the agent. When the content of the solid fine particles exceeds 5.0% by weight, the effect of improving the spinnability is lowered and it becomes difficult to maintain high strength. The solid fine particles used in the present invention are not particularly limited as long as the average particle size is in the range of 0.002 to 0.50 μm, and examples thereof include silica, alumina, kaolin, calcium carbonate, titanium oxide, barium sulfate and the like. . Then, these solid fine particles may be charged into the slurry before the polyester polymerization, or may be added after the esterification.

The glass transition point depressant (Tg depressant) is
It means a compound having a property of lowering the glass transition temperature of the polyester by 2 ° C. or more when the Tg lowering agent is added to the aromatic polyester in an amount of 2% by weight, as compared with the case where the Tg lowering agent is not added. As the Tg lowering agent, any one can be used as long as it has the above properties, but it is preferable to use at least one kind represented by the following general formula (I). R1-O-X-O-R2 (I) (In the formula, X is an aromatic group, R1 and R2 have 6 to 18 carbon atoms.
Represents an alkyl group or an arylalkyl group. In the compound represented by the above general formula, preferred examples of the aromatic group X include the divalent groups shown below.

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[Chemical 8]

And a Tg suitable for use in the present invention.
Examples of the depressant include compounds represented by the following formula.

[Chemical 9]

[Chemical 10]

[Chemical 11]

The amount of Tg depressant added is preferably in the range of 1.0 to 5.0% by weight based on the weight of polyester. When the addition amount of the Tg depressant is less than 1.0% by weight,
Good spinnability does not appear due to the synergistic effect with the addition of the fine particles, and the flexing wear resistance and flexing fatigue resistance are somewhat lacking. On the other hand, when the content exceeds 5.0% by weight, coloring of the polyester may occur, sublimation of the Tg depressant in the spinning process may cause yarn breakage, and high physical strength,
High elongation cannot be maintained. The amount of Tg added is more preferably in the range of 2 to 4% by weight. The timing of adding these Tg depressants is preferably after esterification and before polycondensation.

As an example of the method for producing the fiber of the present invention, for example, a mixed slurry of terephthalic acid and ethylene glycol is esterified by a conventional method, and a predetermined amount of the Tg depressant having the structure of the above formula (XI) is added. After that, polycondensation is performed to obtain polyester chips containing the corresponding fine particles, and further solid-phase polymerization in a conventional method is performed to obtain the desired [η] chips. This is melt-extruded at a melting temperature of about 300 to 310 ° C., injected from a spinneret at an ambient temperature of about 350 to 410 ° C., spun at 400 to 2000 m / min, and subsequently stretched in one stage or two stages. ~ 250 ° C
After heat-fixing at, apply 88-96% limited shrinkage to 25
It can be produced by winding at 00 to 4000 m / min. The polyester fiber of the present invention thus obtained can be used in the field of industrial materials that require high strength and high elongation, so-called high toughness, and further make use of the characteristics of high bending wear resistance and bending fatigue resistance. be able to. The fishing net using the high toughness polyester fiber has improved bending wear resistance and bending fatigue resistance as compared with the fishing net using the conventional polyester fiber, and has a high elongation so that the stress is well dispersed, and for example, It is a highly durable fishing net that is less likely to cause stress concentration during netting, and thus is unlikely to break.

Further, the seat belt using the high toughness polyester of the present invention as a warp or a part of the warp has a large energy absorption at the time of shock and is useful as a so-called energy absorption belt which does not easily damage the human body.
Furthermore, if a mesh fabric for construction (so-called curing mesh) or construction (so-called curing sheet) is made using the high toughness polyester fiber, the amount of fibers used can be greatly reduced due to the high toughness, and the weight of the fabric can be reduced. , Workability (especially work in high places) is significantly improved.

Further, a fabric for civil engineering work using the high toughness polyester fiber, for example, a scour prevention fabric, is easy to be constructed because it easily follows the irregularities of the ground, irregularities on rocks such as caisson, and is not easily broken, and is durable. Is good,
Very useful. Further, the conveyor belt using the woven fabric having the high toughness polyester fiber as a warp has a large resistance to impact force, foreign matter biting, etc., and is useful as a highly durable belt. In addition, sewing threads, ropes, safety nets, tents, canvas, tarpaulins, rubber materials, base fabrics for airbags, base fabrics for parachutes, base fabrics for paragliders, yarns for kites, etc., high toughness, high bending wear resistance, high It can be used very effectively in fields requiring flex fatigue resistance and high durability. The high toughness polyester fiber according to the present invention is a filament as it is, or tow,
Alternatively, it can be used as a spun yarn as a cut fiber or can be used as a non-woven fabric.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, each physical property in an Example was measured and calculated | required by the following method. (1) It was measured with an o-chlorophenol solution having an intrinsic viscosity of 30 ° C. (2) Dry strength (g / d) and dry elongation (%) Measured according to JIS L-1013. (3) Flexural wear resistance (number of times K) It was measured according to JIS L-1096 A-2 method. (4) As for the bending fatigue resistance sample, a person who was RFL-treated with a cord configuration of 1000 d / 1f × 2 and a twisting condition of 20 × 20/10 cmZS was prepared. The bending test was carried out by the firestone method of JIS L-1017 at 25Φ × 250,000 times, and the strength value S ₁ of the sample after the test was measured. (5) Average particle size of fine particles in fibers Calculated based on a centrifugal sedimentation curve obtained by using a centrifugal particle size measuring device (CAPA-5000 type, manufactured by Horiba Ltd.).

Examples 1 to 6 and Comparative Examples 1 and 2 The fibers of Examples and Comparative Examples were manufactured by the following method. A mixed slurry of terephthalic acid and ethylene glycol is esterified by a conventional method, a predetermined amount of the Tg depressant having the structure of the above formula (XI) is added, and then polycondensation is performed,
A polyester chip of [η] = 0.86 containing the corresponding fine particles was obtained. This was further subjected to conventional solid phase polymerization to obtain a [η] chip suitable for the degree of polymerization for each purpose.
This is melt extruded at a melting temperature of 300 to 305 ° C.,
Approximately 400 by injecting from the die at ambient temperature of 400 ℃
After being spun at ~ 1000 m / min, it is subsequently drawn in one or two steps and heat set at 240 to 245 ° C, then 90
-Limited shrinkage of ~ 95%, wound at 2500-3500m / min, 250d / 48fil and 500d / 9
A 6 ton high toughness polyester fiber was obtained. Table 1 shows individual manufacturing conditions in Examples and Comparative Examples.
Details of the polyester fibers obtained in these experiments are shown in Table 2.
It was shown to.

[Table 1]

[Table 2]

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-6-25914 (JP, A) JP-A-62-112572 (JP, A) JP-A-3-206117 (JP, A) JP-A-4- 257318 (JP, A) JP-A-3-223382 (JP, A) JP-A-52-99317 (JP, A) JP-B 47-40570 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) D01F 6 / 62,6 / 84,6 / 92

Claims (2)

(57) [Claims] 1. An intrinsic viscosity [η] having an ethylene terephthalate unit as a main repeating unit is 0.90 or more and 1.0 or more.
It is composed of polyester of 1 or less and has an average particle size of 0.
Solid fine particles of 002 μm or more and 0.50 μm or less are 0.0
Contains 2 wt% to 5.0 wt% and has a dry strength of 5 g /
d or more and 7.33 g / d or less , dry elongation is 30% or more and 60%
Ri der less, toughness T represented by the following following formula (1) 25
0 or more and 292 or less and represented by the following general formula (I)
1.0% by weight or more, at least 5.0% by weight of at least one compound
Contains less than 100% by weight and has flexural wear resistance (number of times K) of 1300 times or more
Polyester fiber characterized by being above . T = dry strength (g / d) x dry elongation (%) (1) R1-O-X-O-R2 (I) (wherein X is an aromatic group, R1 and R2 are C6-18).
Represents an alkyl group or an arylalkyl group. ) 2. A strong retention rate represented by the following formula (2):
(L) is 40% or more, in Claim 1 characterized by the above-mentioned.
The listed polyester fiber. L = (S ₁  / S ₀  ) × 100 (%) However, S ₀  = Strength value S before bending fatigue test ₁  = 250,000 times
Strength value after flex fatigue test