KR102532874B1 - Artificial turf system for preventing overheating - Google Patents

Abstract

The present invention relates to an artificial turf system for preventing overheating, comprising a grass mat made of pile yarn and foam paper, 10 to 40% by weight of a styrenic polymer, 6 to 35% by weight of an olefinic resin, 10 to 40% by weight of process oil, and 5 to 40% by weight of an inorganic filler. It includes a filler containing 40% by weight and 0.05 to 2% by weight of bentonite, which can be laid on the grass mat, and a shock absorbing pad that buffers and supports the grass mat. The pile yarn may include a polyolefin resin and a nucleating agent, and may have a light transmittance of 20% or more.
The shock absorbing pad is a honeycomb, and may include a shock absorbing layer having a foaming ratio of 10 to 40 times by chemical crosslinking, and a fiber layer disposed on the shock absorbing layer and made of crimped short fibers and low melting short fibers.

Description

Artificial turf system for preventing overheating}

The present invention relates to an overheating prevention artificial turf system.

In the playground, artificial turf is installed to imitate the characteristics, shape, and use of natural turf, is easy to maintain and costs less compared to natural turf, solves the shortage of natural turf, and improves the quality and quantity of athletic performance. there is.

The key performance of artificial turf is to realize shock absorption, and for this effect, when installing artificial turf, after installing a shock absorbing pad, a turf mat is constructed thereon. The shock absorbing pad is a component to realize the key performance of artificial turf, such as shock absorption. In order to realize these functions, the function of the shock absorbing pad should also have the performance of artificial turf, but it is neglected because it is not visually recognized after construction, and over-foamed polyethylene plastic material is mainly used for economic reasons.

Accordingly, contraction and expansion of the shock absorbing pad after the artificial turf is constructed affects the playability and causes many defects such as irreversible compression. are doing

In addition, the temperature of the playground where artificial turf is constructed is 15 ° C higher than that of the playground where natural grass is constructed, absorbs solar heat, and the resulting high temperature phenomenon is aggravated by the heat sink phenomenon, approaching 60 ~ 75 ° C. In particular, when sliding on an artificial turf playground with a surface temperature of more than 60 ° C, frictional heat is added, resulting in skin burns in severe cases, and increased fatigue due to high temperature, resulting in poor usability.

An attempt was made to lower the surface temperature of the artificial turf playground by supplying water to solve the shortcoming of the rapid temperature increase in the artificial turf playground. The time to see the effect is very limited, only about 20 minutes, and the effect is insignificant.

In addition, the pile yarn depicting natural grass in artificial turf partially reflects and scatters light, causing glare, and absorbing light to improve the temperature of pile yarn.

Accordingly, there is a need for a technique capable of lowering the surface temperature of pile yarn.

In addition, artificial turf is mainly filled with a certain amount of silica sand and synthetic rubber filler between the pile yarns of artificial turf in order to realize safety such as shock absorption and rolling resistance similar to natural turf and constant mutual characteristics of play with a ball. It is being used.

Instead of recycled soft plastic, hard carbon and plasticizer, or recycled soft plastic, thermosetting elastomer EPDM, elastomer such as waste tire powder, or thermoplastic rubber such as styrene-ethylene-butadiene-styrene (hereinafter, SEBS) was used as the filler.

However, there are cases in which burns occur due to the high surface temperature of the artificial turf when sliding in a high temperature period. In this regard, there are a number of related patents for reducing the surface temperature of the filler, but the effect of reducing the surface temperature is low, so the user experience and practical effect are insignificant.

Republic of Korea Patent No. 10-1842999 (2018.03.22.) Republic of Korea Patent No. 10-2055556 (2019.12.09.) Republic of Korea Patent Registration No. 10-2111114 (2020.05.15.)

The present invention provides an overheating prevention artificial turf system in which shock absorbing performance of a shock absorbing pad is not deteriorated and drainage is improved.

The present invention provides an overheating prevention artificial turf system that can be used semi-permanently without deformation after the shock absorbing pad is installed.

The present invention provides an overheat-resistant artificial turf system capable of preventing user burns and glare by improving light transmittance and lowering light absorption when manufacturing pile yarns.

The present invention provides an overheating prevention artificial turf system capable of increasing the durability of a filler and exhibiting a temperature reduction effect due to excellent moisture absorbency.

An overheating prevention artificial turf system according to an embodiment of the present invention comprises a grass mat made of pile yarn and foam paper, 10 to 40% by weight of a styrenic polymer, 5 to 35% by weight of an olefinic resin, 10 to 40% by weight of process oil, and an inorganic filler. A filler containing 5 to 40% by weight and 0.05 to 2% by weight of bentonite, which can be laid on the grass mat, and a shock absorbing pad that buffers and supports the grass mat.

The pile yarn may include a polyolefin resin and a nucleating agent, and may have a light transmittance of 20% or more.

The shock absorbing pad is a honeycomb, and may include a shock absorbing layer having a foaming ratio of 10 to 40 times by chemical crosslinking, and a fiber layer disposed on the shock absorbing layer and made of crimped short fibers and low melting short fibers.

In the fiber layer, the ratio of crimped short fibers may be 50 to 75% by weight, and the ratio of low melting point short fibers may be 25 to 50% by weight.

The crimped staple fiber is at least one selected from the group consisting of polyolefin, polyethylene terephthalate and polyamide, and may have a fineness of 15 to 50 denier and a length of 20 to 80 mm.

The low-melting short fibers are at least one selected from the group consisting of polyolefin, polyethylene terephthalate and polyamide, and may have a fineness of 2 to 10 denier, a length of 20 to 80 mm, and a melting point of 110 to 150 ° C.

A thickness ratio of the fiber layer and the shock absorbing layer may be 1:1 to 1:50.

The shock absorbing pad may further include a bonding layer positioned between the shock absorbing layer and the fiber layer.

The thickness of the bonding layer may be 0.01 to 1 mm.

The honeycomb has a repeating shape of a rhombus with openings formed at the center thereof, and the openings may have a rhombic shape and have an inner horizontal length of 5 to 30 mm and an inner vertical length of 20 to 60 mm.

The polyolefin resin is one selected from the group consisting of Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), and Polypropylene (PP). may be ideal

The nucleating agent may be at least one selected from the group consisting of substituted sorbitol, salts of carboxylic acids, low molecular weight polyolefins, ionomer resins, and organic phosphate salts.

The pile yarn may include 98.5 to 99.5% by weight of a polyolefin resin, 0.01 to 0.5% by weight of a nucleating agent, 0.01 to 0.5% by weight of a flame retardant, and 0.01 to 0.5% by weight of a weathering agent.

The crystallinity of the pile yarn may be 40% or less.

The styrene-based polymer is a styrene-ethylene-butadiene-styrene copolymer (SEBS), a styrene-butadiene-styrene copolymer (SBS), a styrene-ethylene-propylene-styrene copolymer (SEPS), a hydrogenated styrene-isoprene-butadiene copolymer (Hydrogenated styrene-isoprene-butadiene copolymer, HSIB) and styrene-isoprene-styrene copolymer (SIS).

The olefin-based resin may be an ethylene-based resin, a propylene-based resin, or a mixture thereof.

The process oil may be at least one selected from the group consisting of paraffinic, naphthenic, and aromatic process oils.

The inorganic filler may be at least one selected from the group consisting of calcium carbonate, activated carbon, and mica.

The bentonite has a particle size of 70 μm or less and may be sodium bentonite.

The bentonite may have a moisture content of 10 to 15%.

The present invention has the effect of reducing the impact applied to the user during use because the shock absorbing layer is composed of foam.

According to the present invention, since the shock absorbing layer is formed of a honeycomb, the shock absorbing effect is maintained and drainage is improved.

The present invention has an effect of securing shape stability by preventing shape deformation of the shock absorbing layer by further including a fiber layer in the shock absorbing layer.

In the present invention, since the fibrous layer of the shock-absorbing layer is composed of crimped short fibers and low-melting short fibers, it has excellent shape stability, excellent shock absorption, and no deterioration in drainage performance.

In the present invention, since the filler includes bentonite, durability is excellent and moisture absorption is excellent, so that there is a temperature reduction effect.

In the present invention, when the pile yarn and the filler are used together, a higher temperature reduction effect is obtained than when the filler of the present embodiment is used in the general pile yarn. Accordingly, there is a synergistic effect of reducing the temperature when using the pile yarn and the filler according to the present embodiment.

In the present invention, by limiting the light transmittance of the pile yarn to 20% or more, the light absorption and reflectance are low and the light transmittance is excellent, thereby reducing the temperature.

In the present invention, the pile yarn contains a nucleating agent in a specific amount, so that the light transmittance is excellent and the radioactivity is excellent.

The present invention has an excellent spinnability effect by limiting the crystallinity of the pile yarn to 40% or less.

1 is a schematic view showing an overheating prevention artificial turf system according to an embodiment of the present invention.
2 is a schematic view showing a state in which the pile part of FIG. 1 consists of mono pile yarn and crimp pile yarn;
3 is a plan view showing a shock absorbing layer of the shock absorbing pad of FIG. 1;
4 is a cross-sectional view showing another embodiment of the shock absorbing pad of FIG. 3;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Like reference numerals have been assigned to like parts throughout the specification.

Then, an overheating prevention artificial turf system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4 .

1 is a schematic view showing an overheating prevention artificial turf system according to an embodiment of the present invention, FIG. 2 is a schematic view showing a state in which the pile part of FIG. 1 is composed of mono pile yarns and crimp pile yarns, and FIG. 3 is a schematic view of the impact of FIG. It is a plan view showing a shock absorbing layer of the absorption pad, and FIG. 4 is a cross-sectional view showing another embodiment of the shock absorbing pad of FIG. 3 .

Referring to FIG. 1 , the overheating prevention artificial turf system 1 according to the present embodiment includes a grass mat 100, a shock absorbing pad 200, and a filler 300, and increases shock absorbing performance and exhibits a temperature reduction effect. do.

The grass mat 100 includes a pile part 110, bubble paper 120, and backing paper 130.

The bubble paper 120 is coupled with the pile part 110 and may be at least one selected from the group consisting of polyolefin woven fabric, polyester woven fabric, and non-woven fabric. Specifically, the polyolefin woven fabric is a polypropylene woven fabric. can be

The backing paper 130 is disposed on the bubble paper 120 and coupled to the pile part 110, and the pile part 110 is fixed so as not to be separated from the bubble paper 120. The backing paper 130 is coupled to the pile part 110 by thermal fusion.

The backing paper 130 serves to enhance the shape stability of the artificial turf system 1 for preventing overheating, reduce noise, enhance tear strength, and enhance pull-out strength of piles. The backing paper 130 may be formed of a material such as polyolefin, polyester, latex, SBR, or PU, and preferably may be formed of a long-fiber nonwoven fabric made of polypropylene or polyester.

Polyester may be polyethylene terephthalate, and the backing paper formed of the long-fiber nonwoven fabric has excellent mechanical strength and weather resistance, and does not undergo deformation or physical property change even after long-term installation due to its mechanical strength.

Such a backing paper 130 has excellent water permeability, so it can exert an excellent drainage effect, and it has an effect of dispersing stress concentrated on the ground, so that the bearing capacity of the road surface can be improved.

The pile part 110 is coupled with the bubble paper 120 and protrudes. A plurality of pile units 110 are disposed on the foam paper 120 to simulate natural grass. The pile unit 110 is composed of a plurality of mono pile yarns 111. The pile unit 110 may include a plurality of crimp pile yarns 112 . As shown in FIG. 2, the pile unit 110 may be formed by mixing a plurality of mono pile yarns 111 and a plurality of crimp pile yarns 112. At this time, the crimp pile yarn 112 supports the mono pile yarn 111 to increase the uprightness of the mono pile yarn 111.

Pile yarn (mono pile yarn 111 or crimp pile yarn 112) constituting the pile unit 110 has the following characteristics.

Pile yarn contains a polyolefin resin and a nucleating agent.

The polyolefin resin may be at least one selected from the group consisting of Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), and Polypropylene (PP). It may be preferably linear low density polyethylene (LLDPE).

A nucleating agent is added to increase the crystallization rate of the polyolefin resin and improve the transparency of the pile yarn. The nucleating agent may be at least one selected from the group consisting of substituted sorbitol, salts of carboxylic acids, low molecular weight polyolefins, ionomer resins, and organic phosphate salts, preferably organic phosphate salts.

The organic phosphate salt may be at least one selected from the group consisting of zinc phenyl phosphate, sodium-2,2-methylene bis phosphate, and sodium diphosphate.

Pile yarn may have a light transmittance of 20% or more, preferably 50% or more, and more preferably 60 to 80%. If the light transmittance is less than 20%, it is difficult to implement transparency and the light absorption rate increases, which may decrease the temperature reduction effect of the pile yarn.

If the light transmittance of the pile yarn exceeds 80%, the crystallinity of the pile yarn may increase, resulting in cutting, and productivity and spinnability may be lowered.

The crystallinity of the pile yarn may be 40% or less, preferably 20 to 40%. If the crystallinity of pile yarn exceeds 40%, cutting may occur and productivity and spinnability may decrease, and if it is less than 20%, light transmittance may be low, and temperature reduction efficiency may decrease.

Pile yarn may further include a flame retardant and a weathering agent.

Pile yarn may include 98.5 to 99.5% by weight of polyolefin resin, 0.01 to 0.5% by weight of a nucleating agent, 0.01 to 0.5% by weight of a flame retardant, and 0.01 to 0.5% by weight of a weathering agent.

If the content of the nucleating agent in the pile yarn is less than 0.01% by weight, light transmittance may decrease, and if it exceeds 0.5% by weight, cutting may occur and productivity and spinnability may decrease.

In the pile yarn, the flame retardant may be a non-halogen flame retardant. The non-halogen flame retardant may be at least one non-halogen flame retardant selected from the group consisting of magnesium oxide, bentonite-modified antimony, sodium ammonium, aluminum hydroxide, and zinc borate, or melamine cyanurate.

The content of the flame retardant may be 0.01 to 0.5% by weight, and may exhibit excellent flame retardancy while maintaining light transmittance within the content range.

The weathering agent may be a benzophenone-type or amine-type weathering agent, and may preferably be a friendly amine oligomer. The content of the weathering agent may be 0.01 to 0.5% by weight, and excellent durability may be exhibited while maintaining light transmittance within the content range.

In this way, by including the nucleating agent in a specific content of the pile yarn, it is possible to improve the light transmittance to improve the temperature reduction efficiency and improve the radiation.

Such a pile yarn can be manufactured in the following way.

The pile yarn includes mixing and spinning polyolefin, a nucleating agent, a flame retardant, and a weathering agent, and drawing the spun material.

In the spinning step, 98.5 to 99.5% by weight of polyolefin resin, 0.01 to 0.5% by weight of a nucleating agent, 0.01 to 0.5% by weight of a flame retardant, and 0.01 to 0.5% by weight of a weathering agent may be mixed and then spun.

Descriptions of the polyolefin, the nucleating agent, the flame retardant and the weathering agent are the same as those described above.

The spinning step may be performed at 180 to 280 °C and preferably at 200 to 250 °C. During spinning, the pressure may be 10 to 18 MPa, preferably 12 to 15 MPa.

If the spinning temperature is less than 180 ° C, it may not be easy to melt and mix the polyolefin, the nucleating agent, the flame retardant and the weathering agent, so that discharging may not be easy.

In addition, if the pressure is out of the range during spinning, it is not easy to discharge the yarn or cutting may occur.

Stretching may be performed at a stretching ratio of 2 to 5.

If the draw ratio is less than 2, the elongation may be excessive due to insufficient elongation, and if it exceeds 5, the elongation may be excessive and the elongation may be insufficient, so that the properties of the pile yarn may be deteriorated to be used for artificial turf.

The method for manufacturing pile yarn may further include a step of heat shrinking to manufacture crimp pile yarn after the step of stretching.

Heat shrinkage may be performed at 130 to 220°C, and preferably heat shrinkage may be performed at 180 to 210°C. If the heat shrinkage temperature is less than 130 ° C, the crimp rate of the pile yarn may decrease, and if it exceeds 220 ° C, the yarn may melt.

Hereinafter, the pile yarn will be described in more detail through pile yarn examples and pile yarn experimental examples.

[Pile Yarn Example 1]

99.1% by weight of linear low-density polyethylene (LLDPE), 0.3% by weight of nucleating agent (sodium diphosphate), 0.3% by weight of weathering agent (substituted amine oligomer), and 0.3% by weight of non-halogen flame retardant (magnesium oxide) are mixed at 230 to 240 ° C. and irradiated at 12-15 MPa. Thereafter, the spun pile yarn was put into a cooling water bath at 25° C. to cool, and then stretched at 90° C. for 4 minutes to a quadruple length using a drawing roll to manufacture highly permeable artificial turf pile yarn.

[Pile Yarn Example 2]

Pile yarn was prepared in the same manner as in Example 1 except for mixing 99.39% by weight of linear low-density polyethylene (LLDPE), 0.01% by weight of a nucleating agent, 0.3% by weight of a weathering agent, and 0.3% by weight of a flame retardant in pile yarn Example 1. did

[Pile Yarn Example 3]

Pile yarn was prepared in the same manner as in Example 1 except for mixing 99.3% by weight of linear low-density polyethylene (LLDPE), 0.1% by weight of a nucleating agent, 0.3% by weight of a weathering agent, and 0.3% by weight of a flame retardant in pile yarn Example 1. did

[Pile Yarn Example 4]

Pile yarn was prepared in the same manner as in Example 1, except that 98.9% by weight of linear low-density polyethylene (LLDPE), 0.5% by weight of a nucleating agent, 0.3% by weight of a weathering agent, and 0.3% by weight of a flame retardant were mixed in pile yarn Example 1. did

[Pile Yarn Example 5]

Pile yarn was prepared in the same manner as in Example 1, except that 98.4% by weight of linear low-density polyethylene (LLDPE), 1% by weight of nucleating agent, 0.3% by weight of weathering agent, and 0.3% by weight of flame retardant were mixed in pile yarn Example 1. did

[Pile Yarn Example 6]

Pile yarn was prepared in the same manner as in Example 1, except that low density polyethylene (LDPE) was used instead of linear low density polyethylene (LLDPE) in Example 1 of the pile yarn.

[Pile Yarn Example 7]

Pile yarn was prepared in the same manner as in Example 1 except for using high-density polyethylene (HDPE) instead of linear low-density polyethylene (LLDPE) in pile yarn Example 1.

[Pile Yarn Example 8]

Pile yarn was prepared in the same manner as in Example 1, except that polypropylene (PP) was used instead of linear low-density polyethylene (LLDPE) in Pile yarn Example 1.

[Pile Yarn Comparative Example 1]

Pile yarn was prepared in the same manner as in Example 1, except that 99.395% by weight of linear low-density polyethylene (LLDPE), 0.005% by weight of a nucleating agent, 0.3% by weight of a weathering agent, and 0.3% by weight of a flame retardant were mixed in pile yarn Example 1. did

[Pile Yarn Comparative Example 2]

Pile yarn was prepared in the same manner as in Pile yarn Example 1, except that polyethylene terephthalate (PET) was used in Pile yarn Example 1.

[Pile Yarn Comparative Example 3]

Pile yarn was prepared in the same manner as in Pile yarn Example 1, except that nylon was used in Pile yarn Example 1.

[Pile yarn test example 1]

The spinning workability, crystallinity, light transmittance and temperature reduction efficiency of the pile yarns prepared in Pile Yarn Examples 1 to 5 and Pile Yarn Comparative Example 1 were measured by the following measurement methods, and the results are shown in Table 1 below.

[measurement method]

Spinning workability: Check whether or not to cut

Crystallinity of pile yarn: Measure the heat capacity of each sample using a differential scanning calorimeter. confirmed

Light transmittance (%): Check the value obtained by dividing the intensity of the transmitted light by the intensity of the incident light by irradiating the sample with light using a haze meter

Temperature increase rate (%): After irradiating the light irradiator at a distance of 300mm from the sample surface for 15 minutes, the surface temperature of the sample is measured and confirmed as the ratio of the increased temperature to the initial temperature

division Nucleating agent (% by weight) spinning workability Crystallinity (%) Light transmittance (%) Temperature rise rate (%) Pile Yarn Example 1 0.3 Good 32.2 75.2 79 Pile Yarn Example 2 0.01 Good 22.3 62.3 95 Pile Yarn Example 3 0.1 Good 27.5 69.7 86 Pile Yarn Example 4 0.5 Good 37.8 78.2 72 Pile Yarn Example 5 1.0 bad (truncate) 47.3 - - Pile Yarn Comparative Example 1 0.005 Good 21.8 15 (bad) 115

Referring to Table 1, when the content of the nucleating agent was 0.005% by weight (pile yarn comparative example 1), the light transmittance was very low at 15%, so transparency could not be realized, and when the content of the nucleating agent was 1% by weight (pile yarn comparative example 1) Example 5) had a very high crystallinity of 47.3%, and cutting occurred during spinning or stretching.

In addition, when the content of the nucleating agent is 0.01 to 0.5% by weight (pile yarn Examples 1 to 4), it can be seen that the light transmittance is excellent at 50% or more, and the temperature rise rate (%) is low.

[Pile yarn test example 2]

The spinning workability and light transmittance of the pile yarns prepared in Pile Yarn Examples 1, 6 to 8 and Pile Yarn Comparative Examples 2 and 3 were measured by the following measuring method, and the results are shown in Table 2 below.

[measurement method]

Spinning workability: Check whether or not to cut

Light transmittance (%): Check the value obtained by dividing the intensity of the transmitted light by the intensity of the incident light by irradiating the sample with light using a haze meter

division Resin spinning workability Light transmittance (%) Pile Yarn Example 1 LLDPE Good 75.2 Pile Yarn Example 6 LDPE Good 70.2 Pile Yarn Example 7 HDPE Good 68.2 Pile Yarn Example 8 PP Good 69.3 Pile Yarn Comparative Example 2 PET N.G. - Pile yarn comparison example 3 Nylon N.G. -

Referring to Table 2, in the case of using PET (Comparative Example 2 of pile yarn) or nylon, the spinning workability was very low, and the light transmittance could not be measured due to cutting, and it was confirmed that LLDPE had the best light transmittance among polymers. can

In this way, the pile yarn has a light transmittance of 50% or more and a crystallinity of 40% or less by including a specific nucleating agent, and thus can exhibit excellent temperature reduction efficiency and excellent spinnability.

Next, the filler 300 will be described.

The filler 300 is laid on the grass mat 100 to support the pile part 110 and can absorb the shock caused by the player's foot pressure along with the shock absorbing pad 200.

The filler 300 includes 10 to 40% by weight of a styrenic polymer, 5 to 30% by weight of an olefinic resin, 10 to 40% by weight of process oil, 5 to 40% by weight of an inorganic filler, 0.05 to 2% by weight of bentonite, and 0.1 to 2% by weight of a compatibilizer. 10% by weight.

The styrenic polymer imparts elasticity and elastic recovery to the filler and functions as an elastic polymer in the filler. In addition, styrene-based polymers include styrene-ethylene-butadiene-styrene copolymer (SEBS), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-propylene-styrene copolymer (SEPS), hydrogenated styrene-isoprene-butadiene copolymer It may be at least one selected from the group consisting of a hydrogenated styrene-isoprene-butadiene copolymer (HSIB) and a styrene-isoprene-styrene copolymer (SIS), preferably a styrene-ethylene-butadiene-styrene copolymer (SEBS) there is.

Styrene-ethylene-butadiene-styrene (SEBS) is a material that can realize physical properties most similar to natural rubber, absorbs process oil, and has compatibility with olefin-based resins.

Specifically, styrene-ethylene-butadiene-styrene (SEBS) imparts elasticity and elastic recovery, and since it itself has a block structure, it serves to prevent cross-linking during compounding. Styrene-ethylene-butadiene-styrene (SEBS) is a three-dimensional structure composed of styrene hard segments at both ends and ethylene-butadiene soft segments connected between heavy segments.

Styrene-ethylene-butadiene-styrene (SEBS) has a two-phase structure in which hard segments and soft segments are phase separated. The styrene hard segment is a crystalline region that is not mixed with the ethylene-butadiene soft segment, which is an amorphous region, forms physical crosslinks at room temperature, imparts mechanical properties (eg, tensile strength), and has a glass transition temperature (Tg) of about 100 ° C.

The ethylene-butadiene soft segment is a hydrophobic amorphous region that absorbs process oil and has a glass transition temperature (Tg) of about -55°C. The phase separation between the styrene hard segment and the ethylene-butadiene soft segment is due to different solubility parameters (styrene - 9.1, ethylene-butadiene -7.76), and since the degree of phase separation affects mechanical properties, rheological properties, heat resistance, etc., a large degree of phase separation is advantageous. .

The content of the styrenic polymer is 10 to 40% by weight and preferably 20 to 35% by weight based on 100% by weight of the filler. If the content of the styrenic polymer is less than 10% by weight, the elasticity, abrasion resistance, durability, etc. of the filler may deteriorate, and if it exceeds 40% by weight, it is difficult to expect performance improvement compared to manufacturing cost.

Olefin-based resin functions as a curable polymer that determines the hardness of the filler. In addition, the olefin-based polymer may be an ethylene-based resin, a propylene-based resin, or a mixture thereof. Olefin-based resin applied to the filler is one of the curable polymers that determines the hardness and is used to impart light resistance, flowability, internal resistance, and mechanical properties to the filler.

The polyethylene resin includes low-density polyethylene resins produced by a high-pressure method, low-density polyethylene resins produced by a medium-low pressure method, or low-density, medium-density, and high-density polyethylene resins that are copolymers of ethylene and α-olefins.

Propylene-based resins include copolymer resins containing propylene as a main component, such as propylene homopolymers, propylene-ethylene random copolymers, and propylene-ethylene block copolymers.

In order to satisfy the artificial turf system quality standard of A-1 grade according to the artificial turf KS M 3888-1:2013 system quality standard, the content of the olefinic resin is 5 to 30% by weight based on 100% by weight of the filler, preferably 8 to 20% by weight. If the content of the olefin-based resin is less than 5% by weight, the hardness of the filler is low and durability, etc. may be deteriorated, and if it exceeds 30% by weight, the filler does not have soft elasticity and becomes hard, resulting in a decrease in safety performance such as shock absorption.

Process oil is added to secure processability during high-temperature extrusion and to secure uniform mixing between raw materials. The process oil may be at least one selected from the group consisting of paraffinic, naphthenic, and aromatic process oils.

Paraffinic oil improves the flow and color stability of the filler. However, when using more than the proper input amount, durability problems (shape deformation) occur, and when exposed outdoors for a long time, shape distortion and clumping may occur due to oil bleeding, etc., and it can cause fatal problems in heat resistance.

The content of the process oil is 10 to 40% by weight and preferably 15 to 30% by weight based on 100% by weight of the filler. If the process oil content is less than 10% by weight, flowability is poor, resulting in processing problems, and if it exceeds 40% by weight, oil bleeding may occur.

The inorganic filler is added to secure stability of the filler, increase oil absorbency, and perform an appropriate elastic function, and may be at least one selected from the group consisting of calcium carbonate, activated carbon, and mica.

The content of the inorganic filler is 5 to 40% by weight and preferably 10 to 30% by weight based on 100% by weight of the filler. If the inorganic filler content is less than 5% by weight, physical properties such as tensile strength and durability may be deteriorated, and if it exceeds 40% by weight, it is difficult to implement desired performance as inorganic materials such as wear resistance, shape deformation, and elasticity.

Bentonite is a natural clay mainly composed of smectite group minerals and characterized by the physicochemical properties of smectite, and is classified into calcium bentonite and sodium bentonite according to the type of interlayer cation of montmorillonite.

Bentonite is a clay composed of three layers of Si-Al-Si. Due to the imbalance of charges generated in the Gibbsite layer, which is the middle layer of bentonite, the edges of each layer of bentonite have positive and negative polarities, respectively, and this polarity causes water to molecules are attracted and adsorbed. The adsorbed water molecules are gradually vaporized and the temperature reduction effect is realized through the heat of vaporization.

The bentonite may preferably be sodium bentonite. Sodium bentonite has a much higher water absorption effect than calcium bentonite, so it can maximize the temperature reduction effect due to water absorption by suppressing water penetration. Improvement is also effective.

Bentonite may have a particle size of 70 μm or less, preferably 30 to 60 μm. If the particle size of the bentonite exceeds 70 μm, the surface of the filler may be uneven and the quality may deteriorate.

The moisture content of bentonite may be 10 to 15%, and the moisture content is the moisture content, which is calculated as a percentage by dividing the difference between before and after drying by the weight before drying when the sample achieves moisture equilibrium from a low moisture content in the standard state. If the moisture content of bentonite is less than 10%, the temperature reduction effect may be reduced, and if it exceeds 15%, bentonite may expand and the surface of the filler may be uneven, resulting in deterioration in quality.

In addition, the content of bentonite is 0.05 to 2% by weight and preferably 0.1 to 1% by weight based on 100% by weight of the filler. If the content of bentonite is less than 0.05% by weight, the water absorption rate is insignificant and the temperature reduction effect is reduced.

The filler may further include one or more selected from the group consisting of a compatibilizer, an anti-aging agent, an antioxidant, a color master batch, and a flame retardant, and each may contain 0.1 to 10% by weight based on 100% by weight of the filler, preferably 0.5 to 10% by weight. 5% by weight. Types of the compatibilizer, anti-aging agent, antioxidant, color master batch and flame retardant are not particularly limited, and conventional ones can be used.

In addition, since the shape of the filler is spherical and formed in a uniform size, dust due to mechanical friction is not generated, the friction coefficient is also reduced, and elasticity can be increased.

Such a filler can be manufactured in the following way.

The filler 300 is prepared by (a) preparing a filler by mixing and extruding a styrene-based polymer, an olefin-based resin, process oil, an inorganic filler, and bentonite, and (b) cutting the filler into a predetermined shape in water to obtain a granular filler. Manufactured through manufacturing steps.

Step (a) may be performed at 200 to 240 °C. If the temperature is less than 200 ° C, mixing and extrusion may not be easy because the styrenic polymer and olefin resin do not melt, and if the temperature exceeds 240 ° C, the temperature is too high and the styrenic polymer and olefin resin may burn.

Thereafter, the extruded filler may be cut into a predetermined shape in water to prepare a granular filler. Mixing, extruding, cutting, etc. may be performed by arbitrarily selecting means widely known in the art to which the present invention pertains.

The filler may have a particle size of 1.4 to 3.35 mm in average diameter. If the size of the filler is less than 1.4mm, the effect as a filler is reduced and the buffering effect is not expressed, so it is easy to damage joints such as knees during exercise, and the surface can be made slippery, and fine dust is scattered into the air during the manufacturing process. There is a risk of inhalation into the human respiratory tract.

In addition, if the size of the filler exceeds 3.35 mm, the filling effect is not exhibited, and it is difficult to apply the filler to the overheating artificial turf system, and the surface is formed rough, so that the user of the overheating artificial turf system may suffer skin damage when they fall. .

Hereinafter, the filler will be described in more detail through filler examples and filler experimental examples.

[Filling material Example 1]

Styrene-ethylene-butadiene-styrene (SEBS) 30.5% by weight, polypropylene 15% by weight, process oil (paraffinic oil) 20% by weight, calcium carbonate (CaCO3) 25% by weight, bentonite 0.5% by weight (particle size 30-60㎛, Moisture content is 10-15%), green master batch (pigment) 3% by weight, anti-aging agent (TINUVIN 405) 3% by weight, and compatibilizer (maleic anhydride) 3% by weight are put into a blender and mixed at 220 ° C. It was extruded using an extruder. Simultaneously with extrusion molding, the extruded compound was cooled with air and cut to a size of 1.4 to 3.35 mm in diameter to prepare a spherical filler.

[Filling Material Example 2]

A filler was prepared in the same manner as in Example 1, except that 30.9 wt% of styrene-ethylene-butadiene-styrene (SEBS) and 0.1 wt% of bentonite were used.

[Filling material Example 3]

A filler was prepared in the same manner as in Example 1, except that 30 wt% of styrene-ethylene-butadiene-styrene (SEBS) and 1 wt% of bentonite were used.

[Filling Material Comparative Example 1]

A filler was prepared in the same manner as in Example 1, except that 31% by weight of styrene-ethylene-butadiene-styrene (SEBS) was used without using bentonite.

[Filling Material Comparative Example 2]

A filler was prepared in the same manner as in Example 1, except that 30.99 wt% of styrene-ethylene-butadiene-styrene (SEBS) and 0.01 wt% of bentonite were used.

[Filling Material Comparative Example 3]

A filler was prepared in the same manner as in Example 1, except that 26 wt% of styrene-ethylene-butadiene-styrene (SEBS) and 5 wt% of bentonite were used.

Table 3 is a table showing the composition of the fillers prepared in Filler Examples 1 to 3 and Filler Comparative Examples 1 to 3.

Filler content (based on 100% by weight of filler) division styrenic
polymer
(SEBS) Olefin Resin (PP) process
oil weapon
filler
(CaCO3) bento
Night compatibilizer pigment Aging
inhibitor Filler Example 1 30.5 15 20 25 0.5 3 3 3 Filler Example 2 30.9 15 20 25 0.1 3 3 3 Filler Example 3 30 15 20 25 One 3 3 3 Filler Comparative Example 1 31 15 20 25 0 3 3 3 Filler Comparative Example 2 30.99 15 20 25 0.01 3 3 3 Filler Comparative Example 3 26 15 20 25 5 3 3 3

[Filling Material Experimental Example 1]

Using the fillers prepared in Filler Examples 1 to 3 and Comparative Examples 1 and 2, the temperature reduction effect was measured by the following measurement method, and the results are shown in Table 4.

[measurement method]

Temperature reduction effect: Water is sprayed to the extent that the surface is wet on the overheating prevention artificial turf system sample filled with filler. Thereafter, the light irradiator was irradiated at a distance of 300 mm from the sample surface for 30 minutes, and the surface temperature of the sample was measured to confirm the ratio of the increased temperature to the initial temperature.

division Temperature rise rate (%) Filler Example 1 221 Filler Example 2 233 Filler Example 3 215 Filler Comparative Example 1 243 Filler Comparative Example 2 263 Filler Comparative Example 3 209

Referring to Table 4, it can be seen that there is an excellent temperature reduction effect when bentonite is included (filler Examples 1 to 3).

In the case of not including bentonite (filler Comparative Example 1), it can be confirmed that the temperature reduction effect is lower than that of Example 1 including bentonite at the same content.

When the content of bentonite is out of the composition range (filler Comparative Examples 2 and 3), it can be seen that the temperature reduction effect is lower than that of Filler Example 1.

[Filling Material Experimental Example 2]

Using the fillers prepared in Filler Examples 1 to 3 and Filler Comparative Examples 1 and 3, durability was measured by the following measurement method, and the results are shown in Table 5.

[measurement method]

Durability: The evaluation was conducted using 6110 stud abrasion items in KS F 3888-1, and after the first 2,500 cycles, the test was stopped, shape deformation and dust generation were checked, and the abrasion test was conducted up to 10,000 times.

As for the evaluation method, specimens were prepared in the form of an overheating prevention artificial turf system by including the same pile part and silica sand in the spherical filler, and the shape of the filler was confirmed after evaluation.

division Exterior Filler Example 1 Good Filler Example 2 Good Filler Example 3 Good Filler Comparative Example 1 Good Filler Comparative Example 2 Good Filler Comparative Example 3 dust generation

Referring to Table 5, it can be seen that dust is generated when the bentonite content is out of the composition range (filler comparative example 4).

As such, in the case of the filler, as can be seen in the filler experimental example, by including a specific content of styrenic polymer, olefin resin, process oil, inorganic filler and bentonite, it has excellent durability and at the same time has excellent water absorption, resulting in an excellent temperature reduction effect. Turf fill may be provided.

[Temperature reduction experiment example]

The temperature reduction effect when the pile yarn and filler prepared in Pile yarn Example 1 and Filler Example 1 were used together was measured by the following measurement method, and the results are shown in Table 6.

[measurement method]

Temperature reduction effect: Pile yarn of Example 1 is planted, and water is sprayed to such an extent that the surface of the artificial turf system sample filled with the filler of Example 1 is wet. Thereafter, the light irradiator was irradiated at a distance of 300 mm from the sample surface for 30 minutes, and the surface temperature of the sample was measured to confirm the ratio of the increased temperature to the initial temperature.

division Temperature rise rate (%) Filler Example 1 221 Pile Yarn Example 1 and Filler Example 1 195

Referring to Table 6, it can be seen that when the pile yarn and the filler according to the present invention are used together, there is a higher temperature reduction effect than when the filler of the present invention is used for general pile yarn. From this, the pile yarn according to the present invention It can be confirmed that there is a synergistic effect of reducing temperature when using yarn and filler.

Next, the shock absorbing pad 200 will be described.

The shock absorbing pad 200 supports the grass mat 100. The shock absorbing pad 200 absorbs and buffers the impact generated by the player's foot pressure, and improves the player's protection and performance.

The shock absorbing pad 200 includes a shock absorbing layer 210 having a cushioning force, and a fiber layer 220 disposed on a lower surface of the shock absorbing layer 210 . The shock absorbing layer 210 may be formed of a foam having a foaming ratio of 10 to 40 times by chemical crosslinking. The fiber layer 220 may be made of crimped short fibers and low melting point short fibers.

Chemical crosslinking refers to crosslinking by adding a crosslinking co-agent to a polymer, and the foam has an expansion ratio of 10 to 40 times by chemical crosslinking, preferably 15 to 35 times.

If the expansion ratio of the foam is less than 10 times, the adhesion durability between the shock absorbing layer 210 and the bonded fiber layer 220 is lowered, and the surface of the shock absorbing layer 210 is hard and the thickness is too thin, resulting in reduced cushioning and shock absorbing performance. It can be. If the expansion ratio of the foam exceeds 40 times, the adhesion durability between the shock absorbing layer 210 and the bonded fiber layer 220 is improved, but the dimensional stability and durability in the thickness, length and width directions due to irreversible compression and pressing are reduced. .

The density of the shock absorbing layer 210 is 0.025 to 0.1 kg/cm ³ and the thickness may be 5 to 40 mm. When the density of the shock absorbing layer 210 is less than 0.025 kg/cm ³ and the thickness exceeds 40 mm, the cushion feeling is improved but the durability may be deteriorated, and the shape stability and playability of the shock absorbing pad 200 may be deteriorated. If the density of the shock absorbing layer 210 exceeds 0.1 kg/cm ³ and the thickness is less than 5 mm, cushioning and shock absorbing performance may deteriorate.

Referring to FIG. 3 , the shock absorbing layer 210 may have a honeycomb 211 structure in which a plurality of holes are spaced apart. The shock absorbing layer 210 may be manufactured by melting and mixing raw materials, extruding a sheet, and foaming and processing the extruded sheet. The shock absorbing layer 210 may be manufactured by foaming an extruded sheet, processing (cutting) into a honeycomb 211 shape, expanding the width, and fixing with heat treatment.

The honeycomb 211 may have a shape in which a rhombic shape having an opening 212 formed in the center thereof is repeated. The opening 212 may have a rhombic shape, and the inner horizontal length L1 and the inner vertical length L2 of the opening 212 may be 5 to 30 mm and 20 to 60 mm, preferably 10 to 20 mm and 30 to 50 mm. can

If the inner horizontal length L1 and the inner vertical length L2 of the opening 212 are less than 5 mm and 20 mm, the area of each opening 212 may be reduced and the drainage performance may be deteriorated, and the inner horizontal length L1 and the inner vertical length When the length L2 exceeds 30 mm and 60 mm, drainage performance may be improved, but shock absorbing performance and durability of the shock absorbing pad 200 may be deteriorated.

The foam may include 70 to 90% by weight of low density polyethylene, 0.1 to 10% by weight of a crosslinking agent, 5 to 20% by weight of a foaming agent, and 0.1 to 10% by weight of a foaming aid. The foam may exhibit an expansion ratio of 10 to 40 times due to chemical crosslinking within a composition range, may exhibit shock absorbing performance required by the shock absorbing pad 200, and may not deteriorate durability.

Dicumyl Peroxide (DCP) may be used as the crosslinking agent, and Azodicarbonamide (ADA) may be used as the foaming agent. At least one foaming agent selected from the group consisting of calcium carbonate, silica, talc, and zinc oxide may be used.

The fiber layer 220 is made of short fibers and low melting point fibers, and since the fiber layer 220 is made of crimped short fibers and low melting point short fibers, shape stability is excellent, shock absorption is excellent, and drainage performance may not be reduced.

The crimped short fibers may be at least one selected from the group consisting of polyolefin, polyethylene terephthalate and polyamide, and preferably polyethylene terephthalate. Further, the polyolefin may be polyethylene or polypropylene.

The crimped short fibers may have a fineness of 15 to 50 denier and a length of 20 to 80 mm, preferably a fineness of 20 to 30 denier and a length of 25 to 50 mm. If the fineness of the crimped short fibers is less than 15 denier or the length is less than 20 mm, the fiber layer may become thin and the bonding force with the shock absorbing layer may decrease. If the fineness of the crimped short fibers exceeds 50 denier or the length exceeds 80 mm, the drainage performance may deteriorate due to the increase in weight and volume of the fiber layer.

The low-melting short fibers may be at least one selected from the group consisting of polyolefin, polyethylene terephthalate, and polyamide, and may preferably be polyethylene terephthalate. Further, the polyolefin may be polyethylene or polypropylene.

The low-melting short fibers may have a fineness of 2 to 10 denier and a length of 20 to 80 mm, preferably a fineness of 3 to 5 denier and a length of 30 to 50 mm. If the fineness of the low-melting short fibers is less than 2 denier or the length is less than 20 mm, the binding force with the shock-absorbing layer may be reduced. If the fineness of the low-melting short fibers exceeds 10 denier or the length exceeds 80 mm, excessive fusion may occur and thus the shape stability may deteriorate.

Low-melting short fibers may have a melting point of 110 to 150 ° C, preferably 120 to 140 ° C. If the melting point of the low-melting short fibers is less than 110 ° C, the bonding workability between the shock absorbing layer and the fiber layer may not be easy, and if the melting point exceeds 150 ° C, the shape stability of the shock absorbing pad may be adversely affected.

In the fibrous layer 220, the ratio of the crimped short fibers may be 50 to 75% by weight, the ratio of the low-melting short fibers may be 25 to 50% by weight, and preferably the ratio of the crimped short fibers may be 55 to 70% by weight. And the ratio of low-melting short fibers may be 30 to 45% by weight.

If the ratio of short crimped fibers in the fiber layer 220 is less than 50% by weight, the ratio of low-melting short fibers increases, so that the impact absorbing layer 210 and the fiber layer 220 are highly fused, the surface is hardened, and the product shrinks to improve shape stability and Combined workability may deteriorate and drainage performance may deteriorate.

In addition, when the ratio of the crimped short fibers exceeds 75% by weight, the ratio of the low-melting short fibers decreases, so that the shock absorbing layer 210 and the fiber layer 220 are poorly fused, and the fiber layer 220 is separated from the shock absorbing layer 210. Form stability and bonding processability may be deteriorated.

In addition, the fiber layer 220 may be a non-woven fabric, and may be a short-fiber non-woven fabric manufactured by needle punching or stitch bonding.

The weight of the fibrous layer 220 is 40 to 400 g/m ² and the thickness may be 0.1 to 5 mm. When the weight of the fiber layer 220 is less than 40 g/m ² and the thickness is less than 0.1 mm, the shape stability of the shock absorbing pad 200 may deteriorate. If the weight of the fibrous layer 220 exceeds 400 g/m ² and the thickness exceeds 5 mm, the overall weight and thickness of the shock absorbing pad 200 increase, making manufacturing difficult and costly, which may not be economical.

The thickness ratio of the fiber layer 220 and the shock absorbing layer 210 may be 1:1 to 1:50, preferably 1:1 to 1:20, and more preferably 1:1 to 1:10. there is.

If the thickness ratio of the fiber layer 220 and the shock absorbing layer 210 is less than 1:1, the thickness of the shock absorbing layer 210 is thin and the shock absorbing performance may deteriorate. If the ratio exceeds 1:50, the thickness of the fiber layer 220 is too thick. Since it is thin, the shape stability of the shock absorbing pad 200 may deteriorate.

Referring to FIG. 4 , the shock absorbing pad 200 may further include a bonding layer 230 . The bonding layer 230 is disposed between the shock absorbing layer 210 and the fiber layer 220. The thickness of the bonding layer 230 may be 0.01 ~ 1mm, preferably 0.02 ~ 0.3mm. If the thickness of the bonding layer 230 is less than 0.01mm, the bonding strength between each layer may be reduced, and if it exceeds 1mm, the improvement in bonding strength compared to the thickness is not large, so it is not economical.

The bonding layer 230 may be low-density polyethylene, and by using low-density polyethylene, bonding strength between each layer may be improved.

The combination of the fiber layer 220 and the shock absorbing layer 210 and the combination of the fiber layer 220, the bonding layer 230 and the shock absorbing layer 210 may be combined through a laminating process, and each layer is thermally fused through the laminating process. can

The laminating process may be performed at 130 to 170 ° C. If the laminating process temperature is less than 130 ° C., interlayer fusion may not be easy, and if the temperature exceeds 170 ° C., each layer may be thermally deformed or melted.

Such a shock absorbing pad can be manufactured in the following way.

The crimped short fibers and low-melting short fibers are manufactured into the nonwoven fabric fiber layer 220 through a needle punching process.

Raw materials constituting the shock absorbing layer 210 are melt-mixed at 90 to 130° C. and extruded into a sheet shape. Heat is applied to the extruded sheet at 160 to 230° C. to foam it and process it to prepare the shock absorbing layer 210 of the honeycomb.

Thereafter, the shock absorbing layer 210 is thermally fused to the fiber layer 220 at a temperature of 130 to 170° C.

At this time, when each layer is combined, the bonding force may be improved by further including a sheet-shaped bonding layer 230 at the interface. The bonding layer 230 is prepared by melting and mixing raw materials constituting the bonding layer at 90 to 130° C. and then extruding them into a sheet shape.

In the shock absorbing pad 200 manufactured according to this method, since the shock absorbing layer 210 is formed as a honeycomb 211, drainage performance can be improved.

In addition, since the fibrous layer 220 is made of crimped short fibers and low-melting short fibers, drainage performance can be improved and shape stability and bonding stability can be improved.

The shock absorbing pad 200 may further include an antistatic layer, an antibacterial layer, a flame retardant layer, and the like, and layers having various functions may be further included depending on the location and purpose of use.

The shock absorbing pad 200 may be used in combination with an overheating prevention artificial turf system.

Hereinafter, the shock absorbing pad will be described in more detail through examples of the shock absorbing pad and experimental examples of the shock absorbing pad.

[Shock absorbing pad Example 1]

79% by weight of low-density polyethylene (LDPE), 1% by weight of dicumyl peroxide (crosslinking agent), 15% by weight of azodicarbonamide (foaming agent), and 5% by weight of calcium carbonate (foaming aid) were put into an extruder and melted at 110 ° C. By mixing and extruding, a sheet having an expansion ratio of 30 times was prepared. The extruded sheet was foamed with heat of 200° C. and processed to prepare a honeycomb impact absorbing layer. The prepared impact absorbing layer has a density of 0.05 kg/cm ³ and a thickness of 10 mm, an inner horizontal length L1 of the opening is 15 mm, and an inner vertical length L2 is 40 mm.

Mixing 65% by weight of crimped short fibers (polyethylene terephthalate) with a fineness of 25 denier and a length of 35 mm and 35% by weight of low-melting short fibers (polyethylene terephthalate) with a fineness of 4 denier, a length of 40 mm and a melting point of 130 ° C, A fiber layer having a thickness of 2 mm was prepared by needle punching.

Low-density polyethylene was melt-mixed at 110° C. and then extruded to prepare a 0.1 mm sheet (bonding layer).

A shock absorbing pad was prepared by sequentially positioning the fiber layer, the bonding layer and the shock absorbing layer, and heat-sealing each layer by applying heat at 150° C. for 10 minutes in a laminating process.

[Shock absorbing pad Example 2]

A shock absorbing pad was manufactured in the same manner as in Shock absorbing pad Example 1, except that the inner horizontal length of the opening was 30 mm and the inner vertical length was 60 mm in Shock absorbing pad Example 1.

[Shock absorbing pad Example 3]

A shock absorbing pad was manufactured in the same manner as in Shock absorbing pad Example 1, except that the inner horizontal length of the opening in Example 1 was 5 mm and the inner vertical length was 20 mm.

[Shock absorbing pad Example 4]

A shock absorbing pad was manufactured in the same manner as in Shock absorbing pad Example 1, except that the inner horizontal length of the opening was 40 mm and the inner vertical length was 70 mm in Shock absorbing pad Example 1.

[Shock absorbing pad Example 5]

A shock absorbing pad was manufactured in the same manner as in Shock absorbing pad Example 1, except that the inner horizontal length of the opening was 2 mm and the inner vertical length was 10 mm in Shock absorbing pad Example 1.

[Shock absorbing pad Example 6]

A shock-absorbing pad was manufactured in the same manner as in Shock-absorbing pad Example 1, except that the fiber layer in Example 1 was made of 40% by weight of crimped short fibers and 60% by weight of low-melting short fibers.

[Shock absorbing pad Example 7]

A shock-absorbing pad was manufactured in the same manner as in Shock-absorbing pad Example 1, except that the fiber layer in Example 1 was made of 85% by weight of crimped short fibers and 15% by weight of low-melting short fibers.

[Shock Absorption Pad Comparative Example 1]

89% by weight of low-density polyethylene (LDPE), 1% by weight of dicumyl peroxide (crosslinking agent), 5% by weight of azodicarbonamide (foaming agent), and 5% by weight of calcium carbonate (foaming aid) were introduced into an extruder and melted at 110 ° C. By mixing and extruding, a sheet having an expansion ratio of 5 times was prepared. The extruded sheet was foamed with heat of 200° C. and processed to prepare a honeycomb impact absorbing layer.

The prepared impact absorbing layer has a density of 0.2 kg/cm ³ , a thickness of 5 mm, an inner horizontal length L1 of the opening is 15 mm, and an inner vertical length L2 is 40 mm.

Mixing 65% by weight of crimped short fibers (polyethylene terephthalate) with a fineness of 25 denier and a length of 35 mm and 35% by weight of low-melting short fibers (polyethylene terephthalate) with a fineness of 4 denier, a length of 40 mm and a melting point of 130 ° C, A fibrous layer (200 g/m ² ) having a thickness of 2 mm was prepared by needle punching.

Low-density polyethylene was melt-mixed at 110° C. and then extruded to prepare a 0.1 mm sheet (bonding layer).

A shock absorbing pad was prepared by sequentially positioning the fiber layer, the bonding layer and the shock absorbing layer, and heat-sealing each layer by applying heat at 150° C. for 10 minutes in a laminating process.

[Shock Absorption Pad Comparative Example 2]

70% by weight of low-density polyethylene (LDPE), 1% by weight of dicumyl peroxide (crosslinking agent), 24% by weight of azodicarbonamide (foaming agent), and 5% by weight of calcium carbonate (foaming aid) were put into an extruder and melted at 110 ° C. By mixing and extruding, a sheet having an expansion ratio of 45 times was prepared.

The extruded sheet was foamed with heat of 200° C. and processed to prepare a honeycomb impact absorbing layer. The prepared impact absorbing layer has a density of 0.01 kg/cm ³ and a thickness of 45 mm, an inner horizontal length L1 of the opening is 15 mm, and an inner vertical length L2 is 40 mm.

Mixing 65% by weight of crimped short fibers (polyethylene terephthalate) with a fineness of 25 denier and a length of 35 mm and 35% by weight of low-melting short fibers (polyethylene terephthalate) with a fineness of 4 denier, a length of 40 mm and a melting point of 130 ° C, A fibrous layer (200 g/m ² ) having a thickness of 2 mm was prepared by needle punching.

Low-density polyethylene was melt-mixed at 110° C. and then extruded to prepare a 0.1 mm sheet (bonding layer).

A shock absorbing pad was prepared by sequentially positioning the fiber layer, the bonding layer and the shock absorbing layer, and heat-sealing each layer by applying heat at 150° C. for 10 minutes in a laminating process.

[Shock Absorption Pad Comparative Example 3]

79% by weight of low-density polyethylene (LDPE), 1% by weight of dicumyl peroxide (crosslinking agent), 15% by weight of azodicarbonamide (foaming agent), and 5% by weight of calcium carbonate (foaming aid) were put into an extruder and melted at 110 ° C. By mixing and extruding, a sheet having an expansion ratio of 30 times was prepared.

The extruded sheet was foamed with heat of 200° C. and processed to prepare a honeycomb impact absorbing layer. The prepared impact absorbing layer has a density of 0.05 kg/cm ³ and a thickness of 10 mm, an inner horizontal length L1 of the opening is 15 mm, and an inner vertical length L2 is 40 mm.

A fiber layer (200g/m ² ) having a thickness of 2mm was prepared by needle punching low-melting short fibers (polyethylene terephthalate) having a fineness of 4 denier, a length of 40mm and a melting point of 130°C. Low-density polyethylene was melt-mixed at 110° C. and then extruded to prepare a 0.1 mm sheet (bonding layer).

A shock absorbing pad was prepared by sequentially positioning the fiber layer, the bonding layer and the shock absorbing layer, and heat-sealing each layer by applying heat at 150° C. for 10 minutes in a laminating process.

[Shock Absorption Pad Comparative Example 4]

79% by weight of low-density polyethylene (LDPE), 1% by weight of dicumyl peroxide (crosslinking agent), 15% by weight of azodicarbonamide (foaming agent), and 5% by weight of calcium carbonate (foaming aid) were put into an extruder and melted at 110 ° C. By mixing and extruding, a sheet having an expansion ratio of 30 times was prepared. The extruded sheet was foamed with heat of 200° C. and processed to prepare a honeycomb impact absorbing layer. The prepared shock absorbing layer has a density of 0.05 kg/cm ³ , a thickness of 10 mm, an inner horizontal length L1 of the opening is 15 mm, and an inner vertical length L2 is 40 mm.

A fiber layer (200 g/m ² ) having a thickness of 2 mm was prepared by needle punching a crimped short fiber (polyethylene terephthalate) having a fineness of 25 denier and a length of 35 mm. Low-density polyethylene was melt-mixed at 110° C. and then extruded to prepare a 0.1 mm sheet (bonding layer).

A shock absorbing pad was prepared by sequentially positioning the fiber layer, the bonding layer and the shock absorbing layer, and heat-sealing each layer by applying heat at 150° C. for 10 minutes in a laminating process.

[Experimental Example 1 of shock absorbing pad]

In order to measure the shock absorption rate, dimensional stability, drainage, and tensile strength according to the inner horizontal length, inner vertical length, and foaming ratio of the opening of the shock-absorbing layer, shock-absorbing pad Examples 1 to 5 and shock-absorbing pad Comparative Examples 1 and 2 were prepared. Shock absorption, dimensional stability, drainage and tensile strength were measured using the shock absorbing pad according to the following measurement method, and the results are shown in Tables 7 to 10 below.

[measurement method]

Impact absorption rate: evaluated according to KS F 3888-1 test standard.

Dimensional stability: evaluated according to KS F 3888-1 test standard.

Drainage: measured according to KS F 3888-1.

Tensile strength: measured according to KS F 3888-1: 2018.

division Shock absorption rate (%) Shock absorbing pad Example 1 42 Shock absorbing pad Example 2 35 Shock absorbing pad Example 3 48 Shock absorbing pad Example 4 30 Shock absorbing pad Example 5 52 Shock Absorption Pad Comparative Example 1 12 Shock Absorption Pad Comparative Example 2 56

division Length change rate (%) Width change rate (%) Thickness change rate (%) Shock absorbing pad Example 1 2.0 -1.0 -0.5 Shock absorbing pad Example 2 1.0 -0.5 0 Shock absorbing pad Example 3 2.3 -1.0 -0.5 Shock absorbing pad Example 4 3.0 -2.5 -1.0 Shock absorbing pad Example 5 4.5 -3.0 -1.5 Shock Absorption Pad Comparative Example 1 2.0 -1.0 -1.0 Shock Absorption Pad Comparative Example 2 5.0 -3.0 -3.0

division Drainage (mm/hr) Shock absorbing pad Example 1 1850 Shock absorbing pad Example 2 over 2000 Shock absorbing pad Example 3 1800 Shock absorbing pad Example 4 over 2000 Shock absorbing pad Example 5 1500 Shock Absorption Pad Comparative Example 1 over 2000 Shock Absorption Pad Comparative Example 2 1850

division Tensile strength (MPa) Shock absorbing pad Example 1 1.5 Shock absorbing pad Example 2 1.2 Shock absorbing pad Example 3 1.8 Shock absorbing pad Example 4 0.8 Shock absorbing pad Example 5 2.0 Shock Absorption Pad Comparative Example 1 3.5 Shock Absorption Pad Comparative Example 2 0.1

Referring to Table 7, when the foaming ratio is 10 to 40 times and the thickness of the shock absorbing layer is 5 to 40 mm (shock absorbing pad Examples 1 to 5), it can be seen that the shock absorption rate is excellent at 30 to 52%. In contrast, when the foaming ratio is 5 times (shock absorption pad comparative example 1), it can be seen that the shock absorption rate is as low as 12%, and when the foaming ratio is 45 times (shock absorption pad comparison example 2), the shock absorption rate is significantly higher at 56%. It can be seen that there is no improvement.

Referring to Table 8, when the inner horizontal length and inner vertical length of the opening are 10 to 30 mm and 20 to 60 mm (shock absorbing pad Examples 1 to 3), the length change rate is 1 to 2.3% and the width change rate is -1 to - 0.5% and thickness change rate -0.5 to 0%, it can be seen that the durability is very excellent, but when the inner horizontal length and inner vertical length of the opening are 40 mm and 70 mm (shock absorption pad Example 4), the length change rate is 3 to 4.5 %, width change rate is -3 to -2.5% and thickness change rate is -1.5 to -1.0%, indicating poor durability.

On the other hand, when the expansion ratio is 45 times (shock absorption pad Comparative Example 2), the length change rate is 5%, the width change rate is -3.0%, and the thickness change rate is -3.0%, indicating poor durability.

Referring to Table 9, when the inner horizontal length and inner vertical length of the opening were 10 to 30 mm and 20 to 60 mm (shock absorbing pad Examples 1 to 3), it could be seen that the drainage was 1800 or more, which was very excellent, but the inner horizontal length of the opening was very good. When the length and the inner vertical length were 2 mm and 10 mm (shock absorption pad Example 5), it could be seen that drainage was poor.

Referring to Table 10, when the inner horizontal length and the inner vertical length of the opening are 10 to 30 mm and 20 to 60 mm (shock absorbing pad Examples 1 to 3), it can be seen that the tensile strength is 1.2 to 1.8 MPa, which is very excellent in durability. However, when the inner horizontal length and inner vertical length of the opening were 40 mm and 70 mm (shock absorbing pad Example 4), the tensile strength was 0.8 MPa, indicating poor durability.

On the other hand, when the foaming ratio is 45 times (shock absorption pad Comparative Example 2), it can be seen that the tensile strength is 0.1 MPa, indicating low durability.

[Experimental Example 2 of shock absorbing pad]

In order to measure the bonding processability, shape stability and drainage performance according to the material of the fiber layer, the shock absorbing pads prepared in Examples 1, 6, and 7 and Comparative Examples 3 and 4 of shock absorbing pads were used according to the following measurement method. The bonding processability, shape stability and drainage performance were measured, and the results are shown in Table 11 below.

[measurement method]

Bonding workability: After gripping the shock-absorbing layer and the fiber layer using a tensile tester according to KS F 3888-1, the falling shapes were compared by applying force at a speed of 150 mm/min.

Shape stability (width change rate): measured according to KS F 3888-1.

Drainage: measured according to KS F 3888-1.

division bonding processability shape stability
(width change rate %) ploidy Shock absorbing pad Example 1 Good -0.5% Good (over 180mm/h) Shock absorbing pad Example 6 Good -5.5% (product shrinkage) Insufficient (below 100mm/h) Shock absorbing pad Example 7 separation -1.0% (ground plane clearance) Good (over 180mm/h) Shock Absorption Pad Comparative Example 3 Good -5.0% (product shrinkage) Insufficient (below 100mm/h) Shock Absorption Pad Comparative Example 4 separation -1.0% (ground plane clearance) Good (over 180mm/h)

Referring to Table 11, when the fiber layer was composed of short fibers with low melting point (shock absorption pad Comparative Example 3), the bonding processability, shape stability and drainage were very low compared to those of Shock Absorption Pad Example 1, and the fiber layer was composed of crimped short fibers. In the case (shock absorption pad Comparative Example 4), it can also be seen that the bonding processability and shape stability (width change rate) are very low compared to the shock absorption pad Example 1.

In addition, when the content of crimped short fibers and low-melting short fibers is out of the scope of the present invention (shock absorption pad Examples 6 and 7), the bonding processability form stability (width change rate) and drainage are similar to those of shock absorption pad Example 1 Very low in comparison.

As described above, referring to Experimental Example 1 of the shock absorbing pad, it can be seen that the shock absorbing pad has a honeycomb shape, so that drainage is improved and mechanical properties are not lowered.

In addition, referring to Experimental Example 2 of the shock absorbing pad, it can be seen that the shock absorbing pad has improved water drainage and at the same time, mechanical properties are not lowered because the fiber layer is made of crimped short fibers and low-melting short fibers.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

1: overheat protection artificial turf system 100: grass mat
110: pile unit 111: mono pile yarn
112: crimp pile yarn 120: bubble paper
130: backing paper 200: shock absorbing pad
210: shock absorbing layer 211: honeycomb
212 opening 220 fiber layer
230: bonding layer 300: filler

Claims (11)

Grass mat made of pile yarn and foam paper,
10 to 40% by weight of styrenic polymer, 5 to 30% by weight of olefinic resin, 10 to 40% by weight of process oil, 5 to 40% by weight of inorganic filler and 0.05 to 2% by weight of bentonite and can be laid on the lawn mat Fillers and
A shock absorbing pad that buffers and supports the grass mat
Including,
The pile yarn contains 98.5 to 99.5% by weight of a polyolefin resin, 0.01 to 0.5% by weight of a nucleating agent, 0.01 to 0.5% by weight of a flame retardant, and 0.01 to 0.5% by weight of a weathering agent, has a light transmittance of 20% or more, and has a crystallinity of 40% or less ,
The polyolefin resin is one selected from the group consisting of Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), and Polypropylene (PP). more than
The bentonite is characterized in that the moisture content is 10 to 15%,
Anti-overheat artificial turf system. According to claim 1,
The shock absorbing pad
It is a honeycomb shape in which a rhombic shape with an opening formed in the center is repeated,
A shock-absorbing layer having a foaming ratio of 10 to 40 times by chemical crosslinking, and
Disposed on the shock-absorbing layer and comprising a fiber layer made of crimped short fibers and low-melting short fibers,
Anti-overheat artificial turf system. In paragraph 2,
In the fibrous layer, the ratio of the crimped short fibers is 50 to 75% by weight, the ratio of the low-melting short fibers is 25 to 50% by weight, and the crimped short fibers are one selected from the group consisting of polyolefin, polyethylene terephthalate, and polyamide. or more, the fineness is 15 to 50 denier, the length is 20 to 80 mm, the low melting short fiber is at least one selected from the group consisting of polyolefin, polyethylene terephthalate and polyamide, and the fineness is 2 to 10 Denier, the length is 20 ~ 80mm, the melting point is 110 ~ 150 ℃,
Anti-overheat artificial turf system. In paragraph 2,
The thickness ratio of the fiber layer and the shock absorbing layer is 1: 1 to 1:50, overheating prevention artificial turf system. In paragraph 2,
The shock absorbing pad further includes a bonding layer positioned between the shock absorbing layer and the fiber layer,
The thickness of the bonding layer is 0.01 ~ 1mm,
Anti-overheat artificial turf system. In paragraph 2,
The opening is a rhombic shape, the inner horizontal length is 5 to 30 mm, and the inner vertical length is 20 to 60 mm, the overheating prevention artificial turf system. In paragraph 1,
The nucleating agent is at least one selected from the group consisting of substituted sorbitol, salts of carboxylic acids, ionomer resins, and organic phosphate salts, the overheating prevention artificial turf system. delete In paragraph 1,
The styrene-based polymer is a styrene-ethylene-butadiene-styrene copolymer (SEBS), a styrene-butadiene-styrene copolymer (SBS), a styrene-ethylene-propylene-styrene copolymer (SEPS), a hydrogenated styrene-isoprene-butadiene copolymer (Hydrogenated styrene-isoprene-butadiene copolymer, HSIB) and at least one selected from the group consisting of styrene-isoprene-styrene copolymer (SIS), an overheating prevention artificial turf system. In paragraph 1,
The olefin-based resin is an ethylene-based resin, a propylene-based resin, or a mixture thereof, the process oil is at least one selected from the group consisting of paraffinic, naphthenic, and aromatic process oils, and the inorganic filler is calcium carbonate, At least one selected from the group consisting of activated carbon and mica, and the bentonite has a particle size of 70 μm or less and is sodium bentonite,
Anti-overheat artificial turf system. delete

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