JPH1193019A - Polyester yarn for artificial lawn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject yarn having extremely improved light resistance, shape stability, friction resistance, wear resistance, stepping feeling and readiness of removal of stain, substantially comprising a polytrimethylene terephthalate as a raw material, by specifying a single yarn fineness and a glass transition temperature, respectively. SOLUTION: In this polyester yarn for artificial lawn supporting comprising a polytrimethylene terephthalate as a raw material, its single yarn fineness is made 100-6,000 denier, its glass transition temperature is made 45-80 deg.C and its thickness is preferably 5-300 μm. Preferably, the glass transition temperature is adjusted by changing a heat setting temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to polyester fibers for artificial turf, and more particularly, to light resistance, form stability, abrasion resistance and abrasion resistance as compared with artificial turf made of known polyamide fibers, polyester fibers and the like. The present invention relates to a polyester fiber for artificial turf having significantly improved stepping comfort and dirt easiness.

[0002]

2. Description of the Related Art Conventionally, baseball fields, soccer fields, golf courses,
Generally, nylon 6 and nylon 66 are used as artificial yarn for artificial turf used for poolside and interior decoration.
Polyamide fibers such as polypropylene fibers, polyethylene terephthalate fibers and the like are known.

[0003] However, polyamide fibers have excellent durability such as rubbing and abrasion resistance and stepping comfort (excellent in elastic recovery) to some extent, but special stability due to low light resistance of polymers. It was necessary to take measures to improve the light resistance, such as using an agent. Also, when using artificial grass outdoors, the artificial grass surface temperature may reach as high as 70 to 80 ° C in summer, but the glass transition point of the polyamide fiber in a humid state is near room temperature, If used continuously in such an environment, the form of the artificial turf may change. In addition, there is a disadvantage that the fibers may be cracked or cut due to friction and abrasion when used for a long time.

[0004] Polyethylene terephthalate fiber has excellent light resistance, but has extremely poor friction and abrasion resistance, and has a drawback that the texture changes with use due to poor elastic recovery. Also, an artificial turf having a pile portion made of a copolymerized polyester resin has been proposed, in which frictional fusion between the ball and the shoe hardly occurs and adhesion to the lawn-colored ball or the shoe is small (Japanese Patent Laid-Open Publication No. HEI 9-163572). 7-189112
Specifically, a fiber obtained by copolymerizing polyethylene terephthalate with adipic acid, sebacic acid and dodecane diacid at 10 mol% is used. However, since ethylene glycol is used as the diol, the friction and abrasion resistance are low, and the elasticity of the fiber is high, so that the stepping comfort is poor.

[0005]

An object of the present invention is to provide the most basic performance required for artificial turf such as light resistance, form stability, friction and abrasion resistance, stepping comfort, and ease of dirt removal. The purpose of the present invention is to provide a polyester fiber for artificial turf that satisfies the above problem.

[0006]

Means for Solving the Problems The present inventors have searched for fibers for artificial turf that exhibit excellent light resistance, form stability, friction and abrasion resistance, stepping comfort, and easy dirt removal. When using polytrimethylene terephthalate fiber,
The inventors have found that the above-mentioned properties are far superior to those of polyamide fibers, and as a result of various studies on optimization of the fiber structure, the present inventors have reached the present invention.

That is, the present invention consists essentially of polytrimethylene terephthalate and has a single yarn fineness of 100 to 60.
00 denier and glass transition temperature of 45-80 ° C
It is a polyester fiber for artificial turf characterized by being. The polymer constituting the polyester fiber for artificial turf of the present invention is polytrimethylene terephthalate obtained by substantially polycondensing terephthalic acid and 1,3-propanediol.

In the present invention, “substantially” means that it may be a polytrimethylene terephthalate homopolymer or a polytrimethylene terephthalate copolymer shown below. That is, as long as the effects of the present invention are not impaired, isophthalic acid, succinic acid, adipic acid,
Acid components such as 2,6-naphthalenedicarboxylic acid;
Glycol components such as butanediol, 1,6-hexanediol and cyclohexanedimethanol, ε-caprolactone, 4-hydroxybenzoic acid, polyoxyethylene glycol, polytetramethylene glycol, etc.
Less than wt% may be copolymerized.

If necessary, various additives such as matting agents, heat stabilizers, defoaming agents, tinting agents, flame retardants, antioxidants, ultraviolet absorbers, infrared absorbers, crystal nuclei. Agents, optical brighteners and the like may be copolymerized or mixed. The polymer constituting the polyester fiber for artificial turf of the present invention can be polymerized by a known method. For example, a transesterification reaction of terephthalic acid or a lower alcohol ester of terephthalic acid and an excess of 1,3-propanediol in the presence of a catalyst such as tetrabutyl titanate is performed, and then a catalyst such as tetrabutyl titanate is added to the obtained reaction product. In addition, under a vacuum of 0.5 torr or less, 240 to 28
The polymer can be obtained by performing a polycondensation reaction at 0 ° C. When copolymerization is performed, a comonomer can be added at any stage of the above polymerization method. In the case of copolymerizing a carboxylic acid and a derivative thereof, it is preferable to add a comonomer at the beginning of the polymerization, and in the case of copolymerizing an alcohol, it is preferable to add it at the end of the transesterification reaction.

The molecular weight of the polymer constituting the polyester fiber for artificial turf of the present invention can be defined by the intrinsic viscosity measured by the method described in the examples. Intrinsic viscosity [η]
Is usually 0.4 to 2.0, preferably 0.5 to 1.5,
More preferably, it is 0.6 to 1.2. The intrinsic viscosity is 0.
If it is less than 4, the melt viscosity of the polymer is too low.
The spinnability becomes unstable. Also, the strength of the obtained fiber is low and not satisfactory. On the other hand, when the intrinsic viscosity exceeds 2.0, the melt viscosity is too high, so that the metering by the gear pump is not performed smoothly, and the spinnability deteriorates due to poor discharge or the like.

[0011] The polyester fiber for artificial turf of the present invention needs to have a single yarn fineness of 100 to 6000 d.
If the single yarn fineness is less than 100 d, the turf-like feel cannot be obtained when used for artificial turf, and the durability of the fiber is remarkably reduced due to low fiber strength. If it exceeds 6000d, the feeling becomes too hard or too stiff, and a grassy feeling cannot be obtained. In order to obtain a soft touch, 100-500d is preferable, and in order to obtain durability, 300-6000d is preferable. Depending on requirements, fibers having different fineness may be mixed and used.

The polyester fiber for artificial turf of the present invention has a glass transition temperature (hereinafter abbreviated as Tg) of 45 to 80.
It must be in ° C. Since Tg corresponds to the molecular density of the amorphous portion, the smaller the value is, the smaller the molecular density of the amorphous portion is. Tg
If the temperature is less than 45 ° C., molecules tend to move at a low temperature, and the fiber is easily deformed due to local heat generated when repeatedly subjected to sliding and spikes. On the other hand, when Tg exceeds 80 ° C., the rigidity of the fiber is increased, and fuzz is likely to be generated, which is not preferable. From the viewpoint of a good balance between the resistance of the fiber to local heat generation and the rigidity of the fiber, Tg is preferably 45 to 7
0 ° C, more preferably 55-65 ° C.

As described above, since Tg is a structural factor of a fiber, even a polymer having the same molecular structure shows different values depending on spinning conditions such as spinning temperature, spinning speed, draw ratio, and heat treatment temperature. is there. In particular, since this value greatly changes with the heat setting temperature, it is preferable to change the heat setting temperature to set Tg in the above range. In the case of polytrimethylene terephthalate homopolymer, 160
１８０180 ° C. is a preferred heat setting temperature. The cross section of the single yarn of the polyester fiber for artificial turf of the present invention is not particularly limited, and examples thereof include a circle, a triangle, a square, a pentagon, and a flat yarn.

In the case of a flat yarn, there is no particular limitation on the flatness (the ratio of the long side to the short side when the cross section of a single yarn is approximated to a rectangle or an ellipse, or the ratio of the long axis to the short axis). Usually 3 to 100, preferably 3 to 1 to improve light reflection
0. In addition, the cross section of these single yarns may have a bump-like projection, wavy shape, or asymmetric shape. Depending on the requirements, polyester fibers for artificial turf having different cross sections may be mixed.

[0015] The polyester fiber for artificial turf of the present invention having such a cross-sectional shape should have a thickness of 5 to 300 µm, so that it has light resistance, form stability, friction and abrasion resistance, stepping comfort, and easy removal of dirt. This is preferred. The thickness referred to here means the thickness of the fiber.If the fiber is round, it means its diameter.If it is triangular, square, pentagonal, or flat, the fiber stabilizes the fiber in a stable form. Means the thickness when placed.

The polyester fiber for artificial turf of the present invention may be non-twisted or crimped at about 2 to 3000 T / m. If the general fiber properties of the artificial turf polyester fiber of the present invention are shown, the strength is 2.5 to 2.5.
5 g / d, elongation 25-45%, boiling water shrinkage 7-15
%. One of the features of the polyester fiber for artificial turf of the present invention is that the elastic modulus is as low as 20 to 50 g / d,
Elastic recovery rate (return rate at 20% elongation) is 70 to 9
0%. A low modulus of elasticity leads to a soft feel and gives an artificial turf that is comfortable to step on. Also. High elastic recovery leads to good rebound,
After all we give artificial turf which is comfortable to step on.

The polyester fiber for artificial turf of the present invention can be produced by a known method. That is, it can be obtained by winding after extruding from a spinneret and then stretching. Here, performing drawing after winding refers to a method in which, after spinning, winding is performed on a bobbin or the like, and the yarn is drawn using another device, or the polymer extruded from the spinneret is completely cooled with water or air. After being cooled and solidified by, it is wound around the first roll rotating at a constant speed several times or more, so that the tension before and after the roll is not transmitted at all, and installed next to the first roll and the first roll. Refers to a method in which a spinning-drawing step is directly connected, such as drawing between a second roll.

In the present invention, the spinning temperature at which the polymer is melt-spun is 240 to 320 ° C., preferably 245 to 3 ° C.
00 ° C, more preferably 250 ° C to 280, is suitable. If the spinning temperature is lower than 240 ° C., the temperature is too low, and it is difficult to obtain a stable molten state, the resulting fibers have large irregularities, and no satisfactory strength is exhibited. Spinning temperature is 3
Above 20 ° C., thermal decomposition becomes severe, the resulting yarn is colored and does not show satisfactory strength.

The winding speed of the yarn is not particularly limited, but is usually 1500 m / min or less, preferably 50 m / min.
Winding is performed at 0 m / min or less, more preferably at 400 m / min or less. If the winding speed exceeds 1500 m / min, cooling becomes difficult even with water cooling. The stretching ratio during stretching is 2.0 to 4.0 times, preferably 2.2 to 3.7 times,
More preferably, the ratio is 2.5 to 3.5 times. If the draw ratio is 2.0 times or less, the polymer cannot be sufficiently oriented by drawing, and the strength of the obtained yarn will be low. On the other hand, when the ratio is 4.0 times or more, thread breakage is severe, and stable drawing cannot be performed.

The temperature at the time of stretching is 35 to 1 in the stretching zone.
00 ° C, preferably 40 to 100 ° C, more preferably 5 ° C
0 ° C to 100 ° C is good. If the temperature of the drawing zone is lower than 35 ° C., yarn breakage occurs frequently during drawing, and fibers cannot be obtained continuously. On the other hand, if the temperature exceeds 100 ° C., the slipperiness of the fiber with respect to a heating zone such as a drawing roll deteriorates, so that yarn breakage may occur. Also, if necessary, 120 to 180
C. heat setting may be performed.

When the polyester fiber for artificial turf of the present invention is used for artificial turf, the polyester fiber for artificial turf of the present invention is at least 3% or more, preferably 10% or more, and has light resistance, form stability, and friction resistance. More than 50% in order to maximize abrasion, stepping comfort and dirt removal
Most preferably, it is necessary to use 70% or more. Of course, it may be partially combined with artificial turf such as nylon 6, nylon 66 fiber, other polyester fiber, or polyolefin fiber.

There is no particular limitation on the structure of the artificial turf.
The artificial turf may include a backing layer or a cushion layer, and the artificial turf may be formed on the base material in a pile shape, a cut pile shape, a combination thereof, or may be sand-filled. These artificial turf can be manufactured using a known method.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples, but it is needless to say that the present invention is not limited only to Examples. The main measured values in the examples were measured by the following methods. (1) Intrinsic Viscosity This intrinsic viscosity [η] is a value determined based on the following definition formula.

[0024]

(Equation 1)

Ηr in the definition formula is a value obtained by dividing the viscosity of a diluted solution of a polyester polymer dissolved in o-chlorophenol having a purity of 98% or more by the viscosity of the solvent itself measured at 35 ° C. in the same unit, and the relative viscosity It is defined as C is a solute weight value in gram units in 100 ml of the above solution. (2) Tg Tg was measured using DSC200 manufactured by Seiko Denshi Co., Ltd. in dry nitrogen at a heating rate of 20 ° C./min.

(3) Light Resistance The artificial turf was placed on asphalt in Nobeoka City, Miyazaki Prefecture from June to August 1997, and the discoloration was evaluated. The evaluation was based on the evaluation of the degree of fading according to JIS, and was evaluated in 5th to 1st grade (5th grade is good, 1st grade is bad). (4) Durability (Evaluation of shape stability, friction and abrasion resistance) A person weighing 60 kg wearing a baseball spike on artificial turf steps 20,000 times and cracks or cuts artificial turf in three stages. evaluated.

[0027] Cracks and cuts: ○ Cracks and cuts less: △ Cracks and cuts: X

[0028]

Example 1 A polytrimethylene terephthalate homopolymer having an intrinsic viscosity of 0.7 containing a green pigment was melt-spun at 270 ° C. and spun at 50 m / min using a rectangular spinneret. The melt discharged from the spinneret was solidified by water cooling, passed through two rollers, stretched 3.1 times at 100 ° C., and spun into 450 denier flat yarn (150 μm thickness). The strength of the obtained monofilament is 3.6 g /
d, Tg was 65 ° C.

[0029] The fiber is twisted with Z100T / m, and S6
A twist of 0 T / m was applied and eight yarns were combined to obtain a pile part original yarn. Using this yarn, 1/8 gauge with a tuft machine,
The fabric was tufted to a polyethylene terephthalate base fabric according to a standard of 7.6 stitches / inch and a pile height of 5 mm. The thus obtained tufted fabric having a basis weight of 640 g / m ^{2 was} covered with a backing adhesive mainly composed of styrene-butadiene rubber, and both ears were cut to obtain artificial turf. Both light resistance and durability were good, and the pedal was soft and firm and had excellent stepping comfort (Table 1).

Further, 500 golf balls were hit on the artificial turf. Dirt was easily removed by rubbing a little with water.

[0031]

Example 2 Example 1 was repeated with the draw ratio changed to 2.9 (Table 1). Both the light resistance and the durability were good, and the pedal was soft and firm and excellent stepping comfort.

[0032]

[Comparative Example 1] It can be seen that the durability was poor when polytrimethylene terephthalate fiber having an elongation and Tg deviated from the present invention (Table 1).

[0033]

Comparative Example 2 A relative viscosity of 3.4 (2
Using nylon 6 (5 ° C.), an artificial turf was prepared in the same manner as in Example 1 and evaluated. Both light resistance and durability were poor (Table 1). Also, 500 golf balls were hit on this artificial turf, but dirt was difficult to remove by washing with water.

[0034]

Comparative Example 3 10 mol% of adipic acid having an intrinsic viscosity of 0.7
Example 1 was repeated using copolymerized polyethylene terephthalate. The durability was bad. In addition, the stomping feeling was firm and the feeling of stomping was poor (Table 1).

[0035]

[Table 1]

[0036]

The polyester fiber for artificial turf of the present invention comprises:
When used for artificial turf, compared to known artificial turf made of polyamide fiber, polyester fiber, etc., it significantly improves light resistance, form stability, friction and abrasion resistance, stepping comfort, and dirt removal. It will be.

Therefore, the artificial turf using the polyester fiber for artificial turf of the present invention can be used for baseball fields, soccer fields, golf fields,
Very useful for poolside, interior decoration, etc.

Claims (2)

[Claims] Claims (1) The present invention substantially comprises polytrimethylene terephthalate, has a single yarn fineness of 100 to 6000 denier,
A polyester fiber for artificial turf having a glass transition temperature of 45 to 80 ° C. 2. The polyester fiber for artificial turf according to claim 1, wherein the polyester fiber has a thickness of 5 to 300 μm.