JP3480543B2 - Artificial grass - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial lawn developed as a means for artificially expressing a natural lawn. [0002] In recent years, tennis, golf, gateball,
Artificial grass is widely used in practice fields and stadiums for baseball and soccer. The artificial turf is, for example, as shown in FIG. 1, a tuft of pile yarn is woven on a woven or non-woven fabric made of polypropylene or polyester to form a pile so as to give a turf-like appearance. Some of them are used by spreading. Conventional pile yarns include
Yarn obtained by splitting a uniaxially drawn tape made of a material obtained by adding a weather-resistant pigment or light stabilizer to polyvinylidene chloride, polyamide, polypropylene, high-density polyethylene, etc. into a desired shape and twisting it, or the same material Is used in which a plurality of monofilaments each having an irregular cross section are twisted. In particular, artificial turf using polypropylene pile yarn is excellent in workability of sanding (dispersing sand on the surface of artificial turf and uniformly leveling), fading and weather resistance due to long-term use, and cost reduction. It has been widely used because of its superiority. [0003] However, in the artificial turf using pile yarns made of polypropylene, the tip of the pile yarns is liable to fibrillate and wear due to the accumulation of stress accompanying use. In the artificial turf having the improved high-density polyethylene pile yarn, the wear resistance is higher than that of the artificial turf using the polypropylene pile yarn. When a sand spreader was used, the pile yarn fell down, and it was difficult to uniformly scatter a desired amount of sand. The present invention has been made in view of the above circumstances, and has as its object to provide an artificial turf having excellent workability and abrasion resistance in sand pits and high shape retention. [0005] The artificial turf according to the present invention, which has been made to solve the above-mentioned problems, comprises 100 parts by weight of an ethylene-based polymer A and 100 parts by weight of a polyamide-based component B: 5 to 110 parts by weight and at least a part of which is mainly composed of a low-molecular-weight polyolefin having a number-average molecular weight of 800 to 20,000 (hereinafter, referred to as an acid-modified low-molecular-weight PO) whose terminal is acid-modified: 0.5 A pile yarn is formed by a uniaxially drawn strip made of a resin composition containing up to 20 parts by weight. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the artificial grass according to the present invention will be described in detail. This artificial turf comprises a component A composed of an ethylene polymer, a component B composed of a polyamide, and an acid-modified low molecular weight PO having a predetermined number average molecular weight.
A uniaxially drawn strip made of a resin composition containing component C as a main component is planted as a pile yarn 1 in a base fabric 2. [0007] Examples of the ethylene polymer of component A include high-density polyethylene and linear polyethylene. [0008] Among them, as high-density polyethylene,
Examples include a homopolymer of ethylene, a copolymer of ethylene with an α-olefin such as propylene or butene-1, and a mixture thereof. The density (JIS K7112) of the high density polyethylene used is 0.942 to 0.9.
Around 60 g / cm ³ is appropriate. That is, the density is 0.9
If it is lower than 42 g / cm ^3, it becomes difficult to obtain a synthetic yarn for artificial turf having excellent wear resistance, and 0.960 g / cm ^3.
If it exceeds, it is difficult to obtain a raw yarn for artificial grass having good workability of sandboxing. The high-density polyethylene has a melt flow rate (JIS K7210) of 0.3 to 2.
About 0 g / 10 minutes is appropriate, and if it is lower than 0.3 g / 10 minutes, the occurrence of surface roughening of the artificial yarn for grass is remarkable, and if it exceeds 2.0 g / 10 minutes, it is difficult to obtain sufficient strength. Become. On the other hand, examples of the linear polyethylene include C4-C10α- such as butene-1, octene and hexene.
Copolymers of one or more comonomer (s) of olefins with ethylene, and mixtures thereof. The density of the linear polyethylene used is 0.918 to 0.1.
Around 940 g / cm ³ is appropriate. That is, the density is 0.
If it is less than 918 g / cm ^3, it becomes difficult to obtain a synthetic yarn for artificial turf having excellent wear resistance.
^If it exceeds ³ , it will be difficult to obtain a raw yarn for artificial turf with good workability in a sandbox. The melt flow rate of the linear polyethylene is suitably about 0.3 to 10 g / 10 minutes, and when these are lower than 0.3 g / 10 minutes, the occurrence of rough surface of the artificial grass lawn becomes remarkable, 1
It is based on the actual situation that it is difficult to obtain sufficient strength if it exceeds 0 g / 10 minutes. As the polyamide, aliphatic polyamides such as nylon 6, nylon 4.6, nylon 6.6, nylon 6, 10, nylon 11, nylon 12, etc. are mentioned as suitable for use. It can be said that nylon 6 and nylon 6.6 are preferable in terms of excellent properties. As the acid-modified low molecular weight PO, low molecular weight polyolefins such as low molecular weight polypropylene and low molecular weight polyethylene having terminal double bonds (preferably those having 2 to 7 terminal double bonds per 1000 carbon atoms) are suitable. At least one of a saturated carboxylic acid and an anhydride thereof may be used in 0.1.
It is chemically added at a rate of 1 to 12% by weight (preferably 1 to 10% by weight) and has a softening point of about 90 to 170 ° C and an acid value of 10 to 60 mgKOH / g.
The one before and after is suitable. That is, if the terminal double bond is less than 2, the desired acid modification cannot be performed,
If it exceeds 7, the heat resistance of the acid-modified low-molecular-weight PO decreases, which is not preferable. Examples of the unsaturated carboxylic acid include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid, and examples of the anhydride include maleic anhydride, itaconic anhydride, citraconic anhydride, acrylic succinic anhydride, and acrylic anhydride. Nagic acid. The acid modification is carried out by a melt grafting method or a solution grafting method.
The reaction is carried out at 170 (preferably 130 to 240) ° C for a reaction time of 0.5 to 30 hours. The above resin composition (component A, component B, component C) is kneaded with a kneading device such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader mixing roll and the like, and the mixed composition is used for artificial turf. The material of the original yarn.
Alternatively, before being processed into a uniaxially stretched strip, what is so-called dry-blended may be used by mixing with a blender or the like having a stirring blade. Incidentally, to each resin composition, if necessary, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent,
An antibacterial agent, a flame retardant, a pigment, an inorganic filler or a dispersant thereof may be appropriately added. As a method for producing the pile yarn 1, for example, the above-mentioned mixed composition is melt-extruded at 240 to 280 ° C. and solidified by cooling to form a film having a thickness of 50 to 300 μm. Cut into pieces, oven,
The film is stretched 2.5 to 8.0 times in the take-off direction at about 80 to 150 ° C. using a roll, a hot plate or the like, and 3 to 15% relaxation heat treatment at 80 to 160 ° C. using a hot air circulation oven or the like. And the like, so that 100 to 1
0000 denier, yarn width: 0.3-40 mm, yarn thickness: 3
A yarn for artificial grass having a size of 0 to 150 μm can be obtained.
As another method, for example, a monofilament obtained by melt-extruding the above-mentioned mixed composition from a nozzle having pores and cooling and solidifying the mixed composition may be used in a hot water tank or a hot-air circulation type oven.
The film is stretched 2.5 to 9.0 times in the take-off direction at 150 to 150 ° C. and 90 to 160 using a hot water tank or a hot air circulation oven.
Through a process of performing a 3 to 15% relaxation treatment at 50 ° C.
5000 denier, thread diameter: about 0.08 to 1.5 mm
Can be obtained. The monofilament may be any of those having an elliptical cross section, one having a hollow portion, continuous thread, and other irregular shapes. Also, multiple uniaxially stretched thin tapes and monofilaments are twisted, uniaxially stretched tapes are split and twisted,
Furthermore, those processed using existing technology, such as those obtained by bulky processing, may be mentioned. Hereinafter, an example of a general method for producing artificial grass will be described. That is, the raw yarn for artificial grass is used as the primary base cloth 2
4 to 8 stitches with a tufting machine of 5/16 gauge or the like, and a backing material 4 such as styrene-butadiene rubber latex containing an inorganic filler such as calcium carbonate. The tufted pile yarn 1 is fixed to the base fabric 2 by applying from the back surface (solid content: 200 to 800 g / m ² ), and is dried at 100 to 140 ° C. in a hot air circulation type oven or the like, and is subjected to the present invention. An artificial lawn is formed. The woven fabric 2 has a warp of 25.
0 to 1500 denier, 500 to 1500 denier uniaxially stretched tape for the weft, 13 to 24 vertical
It is woven by using a through-ser loom or the like to have a width of book / inch. Plain weave, twill weave, etc. are mentioned as a weave organization. In the following, some examples of stretched tapes 7 formed from a resin composition which is considered to be usable as a raw material for artificial turf yarns are given as samples, and an artificial grass lawn sampled and extracted from the samples is described. Illustrate works and consider their characteristics. Each sample of the artificial turf yarn was prepared by mixing the above-mentioned mixed composition, high-density polyethylene and polypropylene with 6 parts each.
25mm using a 5mmφ extruder and an inflation die
It is melt-extruded into a film at 0 ° C., cooled and solidified while taking it at 12 m / min to form a film. The film is cut into a tape and 5.5 times in the take-off direction at 115 ° C. in a hot air circulating oven. And then subjected to a relaxation heat treatment at 125 ° C. at a relaxation rate of 8%, width: 5 mm, thickness: 80 μm
m of the stretched tape 7. Table 1 shows the properties and mixing ratio of each sample, and Table 2 shows the measurement results of the tensile strength, tensile elongation and wear resistance of each sample. The components not particularly indicated in the column of component A in Table 1 are 100 parts by weight of high-density polyethylene having a density of 0.952 g / cm ³ and a melt flow rate of 0.6 g / 10 minutes and a density of 0. .920 g / cm ³ , melt flow rate: 1.0 g / 10 minutes, and 40 parts by weight of linear polyethylene are blended. Those indicated by a are those having a density of 0.952 g / cm ³ and a melt flow rate of 0.952 g / cm ³ . Rate: 0.6 g / 10 minutes high density polyethylene 100
Parts by weight were used alone as component A. The component indicated by b is a component obtained by using 100 parts by weight of linear polyethylene having a density of 0.935 g / cm ³ and a melt flow rate of 1.0 g / 10 minutes alone as the component A, and is indicated by c. What is density: 0.952g / c
m ³ , Melt flow rate: 0.6 g / 10 minutes 100 parts by weight of high density polyethylene and density: 0.935 g / cm
^3. Melt flow rate: 1.0 g / 10 minutes in which 40 parts by weight of linear polyethylene are blended. N6 in the component B column indicates the use of nylon 6, and the units of the softening point, the acid value, and the blending ratio are ° C and mgKO, respectively.
H / g, parts by weight. [Table 1] [Table 2] Here, the tensile strength and tensile elongation are measured according to JIS.
The abrasion resistance was measured by using a test device shown in FIG. 2 until the stretched tape 7 was cut. In this experimental apparatus, sandpaper (# 100) was attached to the peripheral surface of a rotating roll 5 having an outer diameter of 120 mm, and the rotating roll 5 was rotated at a speed of 20 m / min in the direction of the arrow in FIG. The stretching tape 7 is rubbed, and is stretched by fixing one end and suspending a 500 g weight 6 at the other end. On the other hand, a prototype artificial turf is made of a uniaxially stretched tape having a width of 12 mm and a thickness of 80 μm obtained by the same manufacturing method as that of the above-mentioned sample and processed with a needle blade roll to obtain a continuous mesh structure of about 10,000 deniers. The split yarn is twisted at a rate of 50 turns / m to form a pile yarn 1 for artificial turf. The pile yarn 1 is made of a 1200 denier polypropylene uniaxially stretched tape of 22 yarns / inch. Using a 5/16 gauge tufting machine, a plain weave base fabric 2 having a width and width of 20 / inch width was tufted with a 4.8 stitch to a pile height of 20 mm, and carbonic acid was formed as a solid content. A backing material 4 made of a styrene-butadiene rubber latex containing an inorganic filler such as calcium is applied so as to be 700 g / m 2, and 11 It was subjected to a drying treatment at 0 ° C. Table 3 shows the sanding workability and wear resistance of these prototypes. Regarding the sanding workability, sand was laid on a road surface of asphalt pavement over a width of 4 m and a length of 20 m, and sand 3 having an average particle diameter of 0.53 mm containing silica as a main component was used on a pile surface using a sand spreader. 2
Spread it evenly to 5 kg / m ² and observe the work situation with the naked eye to evaluate it in three grades: good, acceptable and unacceptable. For the abrasion resistance (JIS L1021), use artificial grass before sanding. It was evaluated based on the amount of wear (unit: mg) measured by a Taber abrasion tester. In addition, "good" indicates that it can be spread uniformly in a short time, "good" indicates that it takes slightly longer than "good", and "improper" indicates that the pile yarn 1 has fallen down and it is difficult to put sand. [Table 3] Considering the results, according to Table 3, the prototype NO. 7 compared to Sample No. 7. No. 4, 5, 8, 9 It can be seen that the wear resistance of Nos. 1 to 4 is extremely excellent, that is, the prototype according to the present invention has a significantly smaller amount of wear than the prototype using polypropylene. Reading the properties of these samples from Table 2, the tensile strength was 3
g / d, tensile elongation about 30-40%, abrasion resistance 3
Sample N which was around 00 seconds and obtained a similar numerical value
O. It can be estimated that similar effects can be obtained with artificial grass using 1 to 9, 11, and 12. In addition, these prototypes have obtained favorable results even in terms of workability of sandboxing. Conversely, considering the workability of sandbox,
Prototype NO. Sample Nos. 5 and 6 were used. 10,16
Are components that do not contain component B (polyamide), and it can be said that the importance of component B relating to the workability of sandboxing has appeared. Further, the sample No.
According to the data of Nos. 5 and 6, it is considered that high-density polyethylene and linear polyethylene can be put to practical use by themselves.
O. Sample No. 1 used for Sample No. 1 In No. 5, no linear polyethylene was blended with the component A, and although good in practical use, no good evaluation was obtained. Considering this point, the existence of linear polyethylene cannot be ignored, and a mixture of not less than 5 parts by weight of linear polyethylene and 100 parts by weight of high-density polyethylene is used. Is more desirable. Further, the sample No. 12 and NO. 14 differs from component 14 only in the number average molecular weight, but this difference is remarkably manifested as a difference in abrasion resistance.
It is found that the presence or absence of the sample NO. 12 and NO. It can be confirmed by comparison with No. 15. Originally, acid-modified low molecular weight PO
(Component C) is a compound that is intended to improve the adhesion (compatibility) between the resins that are incompatible with each other, that is, the ethylene-based resin and the polyamide. Improvements in dispersibility of fillers and the like and improvements in various physical properties (good appearance, strength, and difficulty in tearing) have been expected. Here, it can be said that by using the acid-modified low molecular weight PO, both were homogeneously and micro-compatibilized, and it was confirmed that the wear resistance and the processing stability were improved. As shown in Table 2, when the acid-modified low molecular weight PO directly obtained by the above-mentioned acid modification is used as it is, the practical range is a number average molecular weight of about 800 to 20,000. That is, if the number average molecular weight is less than 800, the appearance of the flat yarn tends to be uneven and the strength tends to be low, and if it is more than 20,000, acid denaturation cannot be performed. It has also been found that the same effect can be obtained by diluting an acid-modified low-molecular-weight PO directly obtained by the above-mentioned acid modification with an unmodified one appropriately added thereto. The mode of dilution cannot be mentioned unequivocally because it is diversified. However, in view of the tendency of the various physical properties to decrease as the acid value decreases, it is desired to suppress the degree of dilution as much as possible. As described above, if the range in which the characteristics are inferior is excluded from the data shown above, a preferable compounding ratio is 10 to 100 parts by weight of the polyamide with respect to 100 parts by weight of the ethylene-based polymer (component A). The suitable compounding amount of the acid-modified low-molecular-weight PO is ethylene polymer 1
The range is from 1 to 15 parts by weight based on 00 parts by weight. That is, when the amount of the polyamide is less than 10 parts by weight with respect to 100 parts by weight of the ethylene-based polymer, the possibility that an artificial turf excellent in abrasion resistance is not obtained increases, and the amount exceeds 100 parts by weight. The possibility of yarn breakage during drawing or splitting is increased. If the amount of the acid-modified low-molecular-weight PO is less than 1 part by weight with respect to 100 parts by weight of the ethylene-based polymer, the frequency of thread breakage during stretching increases, and if the amount exceeds 15 parts by weight, the appearance is reduced. Not only does it worsen, but the abrasion resistance of the pile yarn tends to be unsuitable for practical use.
As a practical range, the component B is 5 to 110 parts by weight with respect to the component A: 100 parts by weight, which is slightly wider than the preferable range.
Component C: Will be 0.5-20 parts by weight. As described above, when the artificial turf according to the present invention is used, sand-filling work can be performed efficiently, and the turf can be used in a good state with excellent shape retention for a long period of time. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of an artificial grass according to the present invention. FIG. 2 is a schematic view of an experimental apparatus used for measuring abrasion resistance. [Description of Signs] 1 pile yarn, 2 base cloth, 3 sand 4 backing material, 5 rotation roll, 6 weight, 7 stretch tape

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-268514 (JP, A) JP-A-7-48778 (JP, A) JP-A 9-119036 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) E01C 13/08 B32B 1/00-35/00 D02G 3/06 D05C 17/02

Claims (1)

(57) [Claim 1] Component A comprising an ethylene polymer: 10
Component B consisting of polyamide: 5 to 11 based on 0 parts by weight
A uniaxial resin composition comprising 0 parts by weight and 0.5 to 20 parts by weight of a component C containing 0.5 to 20 parts by weight of a component C mainly composed of a low-molecular-weight polyolefin having a number-average molecular weight of 800 to 20,000 at least partially acid-terminated. An artificial lawn comprising a pile yarn (1) formed by a drawn strip.