KR100868432B1 - Thermoplastic elastomer composition for dynamically crosslinked artificial grass - Google Patents

Abstract

The present invention relates to a thermoplastic elastomer composition for dynamic crosslinked artificial turf, wherein the thermoplastic elastomer composition for dynamic crosslinked artificial turf according to the present invention is a styrene-ethylene / butadiene-styrene polymer (SEBS), a styrene-butadiene-styrene polymer ( SBS), styrene-ethylene / propylene-styrene (SEPS), hydrogenated poly-isoprene / butadiene polymer (SEEPS), styrene-isoprene-styrene copolymer (SIS) 100 parts by weight of; 10 to 80 parts by weight of the olefin polymer; 30 to 500 parts by weight of a process oil consisting of at least one of paraffin, naphthenic and aromatic; 100 to 800 parts by weight of a filler made of at least one of calcium carbonate, talc and mica; 0.5 to 7 parts by weight of a crosslinking agent consisting of peroxide; 1 to 10 parts by weight of the crosslinking accelerator; It comprises 1 to 10 parts by weight of a resin stabilizer and a pigment.

According to the present invention, it is environmentally friendly and harmless to humans, has excellent shock absorption ability, significantly reduces the risk of injury, has excellent light resistance, less discoloration by light after construction, and does not require a pulverization process, which makes mass production easy and economical. In addition, it is possible to obtain a thermoplastic elastomer for artificial turf having advantages of elasticity, wear resistance, oil storage property (prevention of oil bleeding), mechanical properties, and filler storage property.

Description

Thermoplastic elastomer composition for dynamically crosslinked artificial turf {THERMOPLASTIC ELASTIC BODY COMPOUND FOR ARTIFICIAL TURF MANUFACTURED BY DYNAMIC VULCANIZATION}

The present invention relates to a thermoplastic elastomer composition for a dynamic crosslinked artificial turf, and more particularly, a permanent compression line formed by adding a peroxide as a crosslinking agent instead of a conventional vulcanizing crosslinking agent and dynamically crosslinking it through an extruder or the like. The present invention relates to a thermoplastic elastomer composition for artificial turf having excellent sound rate (elastic modulus), wear resistance, oil storage property, mechanical properties, and filler storage property.

Artificial turf is one of the specially used landscaping materials, and is a substitute for artificially made grass in the form of grass. Since it was first manufactured in the United States in 1956, it has been used mainly in sports fields. It can be used in indoor gardens where turf growth is not possible, or in outdoor areas facing the north side of tall buildings with very limited sunshine hours.

Currently, artificial turf is mainly installed in places where natural grass cannot be built (dome ballpark where natural light is closed, where concentration is concentrated, and where it is difficult to grow natural grass in climate). Although it costs a lot of initial construction cost, it is highly preferred because it can be used semi-permanently, the maintenance is easy, and the surface is uniform for exercise.

As artificial turf, artificial turf in which rubber chips and silica sand (filled sand) are filled to give carpet-type artificial turf similar softness and texture to natural grass has been developed and used a lot.

Artificial turf can always maintain greenness and is easy to manage after construction without being restricted by environmental conditions. On the other hand, there is no seasonal feeling and texture is slightly lower than grass, and it has a disadvantage of fading over time. Since it was first adopted at the Astrodome indoor baseball field in Texas in 1966, it has been in the spotlight as an all-weather facility including a soccer field, field hockey field, various interior and leisure facilities.

In general, a method of planting artificial turf is to bury a drain pipe at a depth of about 60 cm underground, put rubble on top of it, compact it, and then put a sand layer on the rubble and compact it. It is constructed by forming a curing machine layer, applying an adhesive layer to the surface of the curing machine layer and adhesively disposing an artificial turf layer thereon.

In addition, a non-woven fabric may be provided on the sand layer, or a shock absorbing layer such as a foam rubber mat or a rubber mat may be installed on the upper part of the hardener layer, and a water field using artificial grass liquor having a length of 12 to 13 mm and being sprayed with water (water field) It is divided into a sandfield field using a length of 25 mm of artificial turf and an artificial turf filled with silica sand and rubber chips.

In particular, when artificial turf ground is constructed in the form of sandfield, silica sand is firstly laid as a filler and EPDM (ethylene-propylene-diene terpolymer) chips, waste tire chips or recycled rubber chips, or general rubber chips are laid secondly. It is being constructed.

Among these fillers, EPDM (ethylene-propylene-diene terpolymer) chips are too expensive to be economical, cannot be recycled at the time of damage, and are not recycled along with general rubber chips. Almost no actual application is made.

In particular, recycled EPDM is used as a ground material for artificial turf. In order to use the EPDM, a large amount of additive must be added to cure after vulcanization, and the additive contains harmful substances such as heavy metals and dioxins. In many cases, the EPDM is a foamed product of industrial products, so it cannot be used as an artificial turf chip, and thus the amount of non-foamed recycled EPDM generated as an artificial turf chip is only a small amount. In addition, it has various problems such as unpleasant odor peculiar to rubber, heavy metal detection and harmful gas generation.

In addition, conventionally, sulfur-based crosslinking agents such as powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, alkylphenol disulfide, and the like are used as the crosslinking agent. Due to this, there is a problem in that heat resistance and mechanical properties are lowered, and extrusion moldability, that is, workability is lowered.

Therefore, Korean Patent No. 78229, proposed and registered by the inventors of the present invention, discloses an elastomeric chip for artificial turf using styrene-based thermoplastic elastomer (S-TPE) to solve the above problem.

According to the thermoplastic elastomer chip for artificial turf, since it is possible to provide an elastomer chip having a low content of volatile organic compounds (TVOC) and polynuclear aromatic hydrocarbons (PAHs) including heavy metals, it is harmless to the human body, and the shape of the chip is circular and Since it can be manufactured in an elliptical shape, there is an advantage that a good touch can be exhibited. Furthermore, the sulfur-based crosslinking agent may not be used, so that the heat resistance and mechanical properties may be prevented from being lowered.

However, even with the thermoplastic elastomer chip for artificial turf, many oils are added to realize low hardness, and the amount of filler added also increases. According to such an elastomer chip, since the oil content is large, in the long term, oil leakage (oil bleeding) is likely to occur, there is a problem that the elasticity can be reduced due to the high content of the filler, resulting in mechanical There is a problem that the degradation of physical properties can proceed quickly.

The present invention is to solve the above problems, an object of the present invention is to add a peroxide (crosslinking agent) to the styrene-based thermoplastic elastomer (S-TPE), using a twin screw extruder, etc. Crosslinking (Dynamic Vulcanization) to provide a thermoplastic elastomer composition for artificial turf having improved elasticity, improved wear resistance, excellent oil storage (prevention of oil bleeding), mechanical properties and filler storage properties than the non-crosslinked thermoplastic elastomer.

The thermoplastic elastomer composition for a dynamic crosslinked artificial grass of the present invention for solving the above problems is styrene-ethylene / butadiene-styrene polymer (SEBS), styrene-butadiene-styrene polymer (SBS), styrene-ethylene / propylene-styrene (SEPS) ), 100 parts by weight of a styrenic block copolymer made of at least one of a hydrogenated poly-isoprene / butadiene polymer (SEEPS) and a styrene-isoprene-styrene copolymer (SIS); 10 to 80 parts by weight of the olefin polymer; 30 to 500 parts by weight of a process oil consisting of at least one of paraffin, naphthenic and aromatic; 100 to 800 parts by weight of a filler made of at least one of calcium carbonate, talc and mica; 0.5 to 7 parts by weight of a crosslinking agent consisting of peroxide; 1 to 10 parts by weight of the crosslinking accelerator; It comprises 1 to 10 parts by weight of a resin stabilizer and a pigment.

Here, the olefin polymer is made of polypropylene and polyethylene, in 100% by weight of the olefin polymer, it is preferable that the polyethylene is 1 to 50% by weight in order to obtain a composition that satisfies both the filler storage and heat resistance.

In addition, the peroxide may be benzoyl peroxide, dibenzoyl peroxide, tert-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide (2,4-dichloro benzoyl peroxide), 2,5-dimethyl-2,5-di (t-butylperoxide) hexane (2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne), 2,5-dimethylhexane -2,5-di (peroxylbenzoate), Dicumyl peroxide, Di- (2,4-dichlorobenzoyl) -peroxide (Di- (2,4-dichlorobenzoyl) -peroxide), Tert-Butyl peroxybenzoate, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane (1,1-di- (tertbutylperoxy) -3 , 3,5-trimethylcyclohexane), di- (2-tert-butylperoxyisopropyl) -benzene, tert-Butylcumylperoxide, Di-tertbutylperoxide, 2,5-dimethyl-2,5-di (tert-butylperoxy-hex At least one of acid-3) (2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3) is excellent in elasticity, abrasion resistance, oil bleeding, mechanical properties and filler storage. It is desirable to have an advantage.

In addition, the crosslinking accelerator may be selected from zinc oxide, magnesium oxide, lysage, p-quinone dioxime, p-dibenzoylquinone dioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene, and methylenedianiline. At least one is preferred for preparing the composition by the dynamic crosslinking method.

According to the present invention, unlike the EDPM used as an artificial turf for conventional artificial grass, it has eco-friendliness and harmlessness to the human body, has excellent shock absorbing power, significantly reduces the risk of injury, and has excellent light resistance and less discoloration due to light after construction. It is possible to obtain a thermoplastic elastomer for crosslinked artificial turf that has the advantages of elasticity, abrasion resistance, oil storage (prevention of oil bleeding), mechanical properties, and filler storage, because it does not require a grinding process and is easy to mass produce. .

Hereinafter, the thermoplastic elastomer composition for the dynamic crosslinked artificial turf according to the present invention will be described in detail.

The thermoplastic elastomer composition for the dynamic crosslinked artificial turf according to the present invention comprises 100 parts by weight of a styrenic block copolymer; 10 to 80 parts by weight of the olefin polymer; 30 to 500 parts by weight of process oil; 100 to 800 parts by weight of a filler; 0.5 to 7 parts by weight of a crosslinking agent consisting of peroxide; 1 to 10 parts by weight of the crosslinking accelerator; It comprises 1 to 10 parts by weight of a resin stabilizer and a pigment.

Thermoplastic Elestomer (TPE) has a wide variable hardness range (Shore A = 20 to 80), low density, good resilience, good mechanical properties, high noise-damping, good aging and good ozone It has excellent characteristics such as small flexibility change over a wide temperature range, good acid and alkali resistance, and good static friction, and is widely used in the automotive field or the home appliance industry.

In particular, the thermoplastic elastomer is an intermediate material between plastic and rubber, and has been used as a substitute material for rubber mainly in automobile parts as it is recognized as a recyclable rubber material.

The thermoplastic elastomer composition may exhibit various characteristic changes depending on the composition and content included therein, and will be described with respect to each component and its content of the thermoplastic elastomer composition to have the characteristics to be pursued in the present invention.

Styrene series  Block copolymer

Styrene-based block copolymers used in the present invention should be used that do not have a double bond, thereby obtaining an elastomer chip excellent in weather resistance.

Styrene-based block copolymers used as the base material in the present invention is applied to give the composition elastic and impact resistance to make a fluffy artificial grass. This includes styrene-ethylene / butadiene-styrene polymer (SEBS), styrene-butadiene-styrene polymer (SBS), styrene-ethylene / propylene-styrene (SEPS), hydrogenated poly-isoprene / butadiene polymer (SEEPS), styrene-isoprene-styrene Copolymers, such as copolymer (SIS), are formed individually or in mixture.

Olefin Polymer

The olefin polymers applied in the present invention are used to impart light resistance, flowability, surface resistance, and mechanical properties to the composition. Generally used ethylene (PE) -based resin or propylene (PP) -based resin and the like may be applied, more preferably crystalline ethylene-based resin or crystalline propylene-based resin is applied.

In particular, in the present invention, unlike the general crushed artificial turf elastomer chip, by mixing the olefin polymer to improve the light resistance, it does not easily discolor.

The ethylene-based resin is a polyethylene resin produced by a conventional method and having a melt index (Melt Index, MI) of 0.01 to 50 g / 10 minutes, preferably 1 to 20 g / 10 minutes at 230 ° C. and a 2.16 kg load.

The polyethylene resin may be a low density polyethylene resin produced by a high pressure method, an ethylene homopolymer produced by a medium or low pressure method, or a low density, medium density and high density polyethylene resin which is a copolymer of ethylene and an α-olefin.

The propylene-based resin includes a propylene-based copolymer resin such as a propylene homopolymer, a propylene-ethylene random copolymer, and a propylene-ethylene block copolymer. The propylene resin is a polypropylene resin having a melt index of 0.01 to 100 g / 10 minutes, preferably 0.05 to 80 g / 10 minutes at 230 ° C. and a load of 2.16 kg.

In the olefin polymer, polyethylene has a higher filler storage ability and excellent affinity with a styrene-based thermoplastic elastomer than polypropyl pen, and thus, polyethylene-polypropylene may be advantageously mixed in terms of abrasion resistance than polyolefin alone. In particular, when a large amount of filler is added, it is preferable to add a large amount of polyethylene. However, since polyethylene has a property of poor heat resistance, it is necessary to control the content of polypropylene-polyethylene in the polymer.

As for the weight ratio of preferable polypropylene-polyethylene, the ethylene content in 100 weight% of said olefin polymers is 1-50 weight%, More preferably, it is 1-40 weight%.

If the content of polyethylene is less than 1% by weight, there is a problem that can not exhibit the storage properties of the filler, when added in excess of 50% by weight there is a problem that the heat resistance is lowered.

In addition, the content of the olefin polymer in the thermoplastic elastomer composition for artificial turf is preferably 10 to 80 parts by weight, more preferably 20 to 50 parts by weight, and even more preferably 100 parts by weight of the styrene-based block copolymer. Preferably it is 20-30 weight part.

When the olefin polymer is added in an amount of 10 parts by weight or less based on 100 parts by weight of the styrenic block copolymer, it is difficult to prevent discoloration of artificial turf formed therefrom due to poor light resistance, and a low flow material is obtained, while the content thereof is When added in an amount of 80 parts by weight or more, there is a problem in that heat resistance and mechanical properties are lowered due to decomposition reactions due to crosslinking agents, etc., which may be included as additives, and extrusion property, that is, workability is lowered.

The manufacture of the styrenic block copolymer and the olefin polymer by melt mixing is intended to utilize by mixing each of the advantages of the styrene-based block copolymer and the olefin polymer, whereby the optimum content as described above is derived.

That is, the combination is intended to complement the elastic and impact resistance of the styrene-based block copolymer, and the properties such as light resistance, mechanical properties, etc. of the olefin polymer by the efficient mixing between mutual materials, the formulation between the raw materials for the complementary It is derived from the weight ratio of the olefin polymer to the styrenic block copolymer.

Process oil

As the process oil used in the present invention, one or a mixture of two or more of paraffinic oils, naphthenic oils, and aromatic oils is used. More preferably, paraffinic oils having excellent light resistance and weather resistance and easy coloring are used. use.

The paraffinic oil used in the present invention is preferably a naphthenic component as a main component and a white oil having no aromatic component at all. This is because aromatic ingredients have a weak disadvantage in light and heat.

The content of the process oil is preferably 30 to 500 parts by weight, more preferably 300 to 50 parts by weight, even more preferably 100 to 250 parts by weight, based on 100 parts by weight of the styrenic block copolymer.

When the content of the process oil is added less than 30 parts by weight, there is a problem in processing due to poor fluidity, and when the content of the process oil exceeds 500 parts by weight, a problem of oil bleeding occurs.

Filling

Fillers used in the present invention are calcium carbonate (CaCO ₃ ), talc (talc, Mg ₃ (OH) ₂ Si ₄ O ₁₀ ), mica (mica), more preferably calcium carbonate is used.

The filler used in the present invention has a specific gravity of 2.9 to 3.2, and has a relatively high specific gravity compared to other components of the thermoplastic elastomer composition. Therefore, when a filler such as calcium carbonate is added to the thermoplastic elastomer composition of the present application, the specific gravity of the raw material is increased to increase the extrusion amount.

The addition of the filler is intended to improve the rigidity and heat distortion temperature. In addition, since calcium carbonate is inexpensive, production costs can be reduced. The blending amount of the filler capable of exhibiting the minimum and maximum effects of the extrusion amount, the rigidity and the heat deformation temperature improvement is 100 to 800 parts by weight, more preferably 200 to 500 parts by weight, and even more preferably, based on 100 parts by weight of the styrene block copolymer. Preferably from 200 to 250 parts by weight.

Resin Stabilizers and Pigments

The resin stabilizer used in the present invention includes a heat stabilizer, an antioxidant, an antioxidant, an ozone stabilizer, a processing aid, a lubricant, an optical stabilizer, and more preferably, a heat stabilizer, an antioxidant, and a light stabilizer are applied. In this invention, the said various types of resin stabilizers are used individually or in mixture.

The resin stabilizer as an antioxidant is to give the antioxidant effect of the composition during molding processing, divinyl benzene, triallyl cyanurate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, polyethylene glycol diketacrylate , Trimethylolpropane triketacrylate and allyl methacrylate can be used alone or in combination.

Resin stabilizers as light stabilizers are used to maximize the light resistance of the olefin polymer, and light stabilizers such as benzotriazole and resorcinol are used.

In addition, the resin stabilizer may be applied to prevent excessive decomposition of the olefin polymer or styrenic block copolymer during mixing and extrusion, and to maintain stability of the radicals generated. These resin stabilizers are pentaerythryl-tetrakis (3- (3,5-tetrabutyl-4-hydroxyphenyl) -propionate, 4,4'-thio-bis (6-t-butyl-3- Methylphenol), phenol, 2,4-bis (1,1-dimethylethyl) -phosphite, or the like can be used alone or in combination.

Pigments are used to color the composition, and green pigment is mainly used in the thermoplastic elastomer composition for manufacturing artificial turf as in the case of the present invention.

The resin stabilizer and the pigment are added in an amount of 1 to 10 parts by weight, more preferably 2 to 5 parts by weight, based on 100 parts by weight of the styrenic block copolymer. If the content of the resin stabilizer and the pigment is less than 1 part by weight, the properties such as thermal stability and oxidation is not well expressed, and if it exceeds 10 parts by weight, it is uneconomical for efficiency.

In addition to the above structure, the present invention may use other known additives. For example, shielding phenolic antioxidants, shielding amine antioxidants, phosphoric acid antioxidants, added to reduce friction between two surfaces that slide in contact with each other, and when the raw materials are mixed and mixed in the machine, the mixed materials melt and come out of the machine. Other additives may include lubricants, which are substances that play a good slip.

peroxide Crosslinking agent

The crosslinking agent is mentioned as a characteristic of this invention. Although the thermoplastic elastomer composition disclosed in Korean Patent No. 780229 has a non-crosslinking method in mind, as described above, oil bleeding is likely to occur and elasticity may be degraded due to a large amount of filler. There may be a problem, the crosslinking agent is applied as a configuration for solving this.

In the present invention, a peroxide crosslinking agent is used. The peroxide crosslinking agent is easier to mix than a sulfide crosslinking agent, and can be heated at a high temperature, and has a short crosslinking time and excellent heat resistance and mechanical properties of the final product, and blooming. It prevents the phenomenon, it is possible to simultaneously crosslink with rubber, polyethylene and olefin polymer, and has the property of increasing heat resistance by crosslinking polyethylene having low heat resistance. In addition, there is an advantage that copolymerization with a polymerizable plasticizer or other additives added for controlling hardness and strength, and has an advantage that it is environmentally friendly than sulfur-based crosslinking agent.

The peroxide used in the present invention is a compound having a large activated radical energy because it has two activated radicals, and there are examples of it being used as a curing agent (crosslinking agent) of plastics and pipes, but there is no example applied to an elastomer for artificial turf. In the present invention, it is particularly intended to take the characteristics such as mechanical properties and oil leakage prevention, improved elasticity.

Types of benzoyl peroxide, dibenzoyl peroxide, tert-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide (2,4-dichloro benzoyl peroxide), 2,5-dimethyl-2,5-di (t-butylperoxide) hexane (2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne), 2,5-dimethylhexane- 2,5-di (peroxylbenzoate), Dicumyl peroxide, Di- (2,4-dichlorobenzoyl) -peroxide (Di- (2,4-dichlorobenzoyl) -peroxide),, Tert-Butyl peroxybenzoate, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane (1,1-di- (tertbutylperoxy) -3, 3,5-trimethylcyclohexane), di- (2-tert-butylperoxyisopropyl) -benzene, tert-Butylcumylperoxide, Di-tertbutylperoxide, 2,5-dimethyl-2,5-di (tert-butylperoxy-hexane-3) (2,5-dim ethyl-2,5-di (tert-butylperoxy) hexyne-3) may be used alone or in combination of two or more thereof.

The content of the peroxide crosslinking agent is 1 to 10 parts by weight, preferably 1.5 to 5 parts by weight, based on 100 parts by weight of the styrenic block copolymer. When the content of the crosslinking agent is added in less than 1 part by weight, there is a concern that the workability, heat resistance, oil storage property, etc., which are the characteristics described above, may be reduced. .

Crosslinking accelerator

Crosslinking accelerators used to enhance the degree of crosslinking in the elastomer composition according to the present invention are generally aldehyde, ammonia, guanidine, thiazole, sulfenamide, thiuram, dithioate, imide, thiourea, etc. Crosslinking accelerators can be used.

Among these, imide-based compounds having excellent thermal stability are HMBMI (1,6Hexamethylene bismaleimide), DMBMI (1,10 Decamethylene bismaleimide), NPMI (N-Phenylmaleimide) or PBMI (1,4 Phenylene bismaleimide) or zinc oxide, magnesium oxide , Lysage, p-quinonedioxime, p-dibenzoylquinonedioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene, methylenedianiline, etc. desirable. More preferably, zinc oxide, magnesium oxide, or the like is used.

The crosslinking accelerator is preferably added in an amount of 0.5 to 7 parts by weight based on 100 parts by weight of the styrenic block copolymer, and more preferably 1.5 to 5 parts by weight. When the content of the crosslinking accelerator is less than 0.5 parts by weight, the effect of crosslinking promotion is less, and when added in excess of 7 parts by weight, there is a disadvantage in that the economical efficiency is lower than the content.

Next, the manufacturing method of the thermoplastic elastomer chip for artificial turfs by this invention containing the thermoplastic elastomer composition which has the said structure is demonstrated.

The method of preparing the thermoplastic elastomer using the composition is not particularly limited, but melt-kneading the components constituting the elastomer (styrene block copolymer, process oil, olefin polymer, filler, stabilizer and pigment, etc.) in a blender, It is good to perform dynamic crosslinking (Dynamic Cure or Dynamic Vulcanization) which adds the crosslinking agent which crosslinks an elastomer component, disperse | distributing the said elastomer component.

The dynamic crosslinking is not limited to a specific method, and a conventional method can be used, and for example, crosslinking can be performed at a temperature of 150 ° C to 300 ° C using a peroxide crosslinking agent. Such crosslinking conditions (temperature, time, etc.) may be suitably determined according to the composition of the composition to be added, and is not particularly limited. Hereinafter, a manufacturing method of the thermoplastic elastomer chip by the dynamic crosslinking method will be described.

First, the styrene-based block copolymer is added to the blender as a primary raw material and preheated at 60 to 120 ° C. for 1 to 10 minutes while stirring. The styrene-based block copolymer and its content is applied to the above-described materials and contents, and the blender applied to the present invention may use a general mixing extrusion apparatus, and preferably a bander kneader, twin screws, extruder (Twin) A device having excellent mixing effects such as a screw extruder, a buss kneader, and a Banbury mixer may be used. A continuous extrusion facility is more preferable than a batch mixer.

In addition, EPDM (ethylene-propylene-diene terpolymer) used as a raw material of a general elastomer chip may be further added together with the styrene-based block copolymer as the primary raw material input in the primary raw material input step. The content is 1 to 100 parts by weight, preferably 50 to 80 parts by weight based on 100 parts by weight of the styrenic block copolymer.

Next, in order to impart elasticity and plasticity to the styrenic block copolymer which is the primary raw material while mixing the primary raw material in the blender, 30 to 500 parts by weight of the process oil is added to 100 parts by weight of the primary raw material. It is added and stirred for 1 to 20 minutes at a stirring speed of 40 to 80 rpm. This slow stirring is to allow the process oil to sufficiently react with the styrenic block copolymer.

This is charged by stirring a secondary raw material containing an olefin polymer, a filler, a resin stabilizer and a pigment, in 100 parts by weight of the primary raw material, the olefin polymer is 10 to 80 parts by weight, the filler 100 to 800 weight part; The secondary raw material including the resin stabilizer and 1 to 10 parts by weight of the pigment is introduced into the blender and stirred.

As described above, this secondary raw material input step is characterized by the elastic and impact resistance of the styrenic block copolymer as the primary raw material, and the mechanical properties of the olefin polymer as the secondary raw material for efficient mixing between the materials. It is intended to complement, and to express the optimal properties by properly mixing the filler, the resin stabilizer and the pigment.

Next, after the peroxide crosslinking agent and the crosslinking accelerator described above are added and stirred together with the first raw material and the second raw material for 1 to 30 minutes, the first raw material and the second raw material, the crosslinking agent, the crosslinking accelerator and the like are added. The containing mixture is subjected to dynamic crosslinking at a temperature of 150 ° C to 300 ° C using an extruder, and extruded to form.

When the components in the blender are crosslinked, kneaded and heat treated under high shear stress such as a twin screw extruder (twin screw extrusion machine) heated to 180 to 200 ° C., a boot kneader, desired physical properties and uniformity can be obtained. The temperature is controlled to be completely heat treated in consideration of the residence time in the 170 to 250 ℃ temperature range. In addition, the stirring is performed at 100 to 400 rpm, preferably 150 to 350 rpm.

After carrying out the above process, the extruded blend is cooled and dried at room temperature, preferably cut into a particle size of 0.5 to 3.0 mm in diameter, more preferably 2.0 to 2.5 mm, for thermoplastic grass for artificial turf. An elastomer chip is produced.

Here, performing cooling and cutting has an advantage that mass production is easy because it does not undergo a grinding process unlike manufacturing thermoplastic elastomer chips for artificial turf utilizing general waste rubber.

 The thermoplastic elastomer composition for artificial turf manufactured by using the above-described method and the thermoplastic elastomer composition formed through the above-described method is preferably formed with a particle size of 0.5 to 3.0 mm, more preferably, a particle size of 2.0 to 2.5. It should be formed in mm.

When the size of the elastomeric chip is less than 0.5mm, the efficiency as a filler is lowered and the buffering effect is not expressed, thus causing damages to joints such as knees during exercise, and having a smooth surface. There is a danger of dust being scattered into the air and inhaled into the respiratory system of the human body. In case of exceeding 3.0mm, the filling effect is also not exerted, and it is difficult to plant artificial turf, and the surface is formed to be rough so that there is a problem of skin damage when the user of artificial turf falls down.

Hereinafter, examples and comparative examples of the dynamic crosslinked artificial turf elastic body according to the present invention will be described through the physical property experiments thereof.

Example  1 and Example  2

Styrene-based block copolymer, paraffin (white) oil, polypropylene and polyethylene 1: 1 ratio of olefin polymer, talsium carbonate filler, peroxide crosslinking agent, crosslinking accelerator, stabilizer and pigment to the content shown in Table 1 below And kneaded in a blender, and extruded in a coaxial twin screw extruder having a screw diameter of 46 mm and a specification of L (length) / D (diameter) = 60. At this time, the processing temperature was 180 to 200 ℃, the screw rotation speed was 300rpm.

Comparative example  1 and Comparative example  2

The compositions were prepared in the same manner as in Example 1 and Example 2, respectively, except only a peroxide crosslinking agent and a crosslinking accelerator.

TABLE 1

Item Example 1 (unit: parts by weight) Example 2 (unit: parts by weight) Styrenic block copolymer 100 100 Paraffin oil 150 150 Olefin Polymer 50 18 Filling 300 270 stabilizator 3 3 Peroxide Crosslinking Agent One One Crosslinking accelerator 2 2

In Table 2, hardness, permanent compression rate (elasticity), oil resistance (oil resistance) as the evaluation items for Example 1 and Comparative Example 1, in Table 2, Example 2 and Comparative Example 2 As an evaluation item for, tensile strength, elongation rate, 100% tensile stress, and abrasion resistance were measured, respectively.

 TABLE 2

Evaluation item Test Methods unit Example 1 Comparative Example 1 Hardness ASTM D2240 Shore a 64 67  Permanent compression  ASTM D395 70 ℃ / 22hr (%) 36 40 100 ° C / 22hr (%) 40 44 120 ℃ / 22hr (%) 44 55 Oil resistance ASTM D471 No.3 Oil 40 ℃ / 24hr (%) 37 38 100 ° C / 70hr (%) 158 Not measurable

TABLE 3

Evaluation item Test Methods unit Example 2 Comparative Example 2 Hardness ASTM D2240 Shore a 47 47 The tensile strength ASTM D638 kgf / cm ² 22 14 Elongation ASTM D638 % 273 327 100% tensile stress ASTM D638 kgf / cm ² 13 8.4 Wear Resistance (NBS) KS M 6625 % 18 32

As shown in <Table 2> and <Table 3>, Examples 1 and 2 have a tensile strength, elongation rate, tensile stress, As well as excellent wear resistance characteristics, it can be seen that exhibits excellent elastic modulus and oil resistance.

Although preferred embodiments and comparative examples of the present invention have been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

Claims (4)

In the thermoplastic elastomer composition for artificial turf, Styrene-ethylene / butadiene-styrene polymer (SEBS), styrene-butadiene-styrene polymer (SBS), styrene-ethylene / propylene-styrene (SEPS), hydrogenated poly-isoprene / butadiene polymer (SEEPS), styrene-isoprene-styrene air 100 parts by weight of a styrenic block copolymer made of at least one of a copolymer (SIS); 10 to 80 parts by weight of an olefin polymer consisting of 50 to 70% by weight of propylene and 30 to 50% by weight of ethylene; 30 to 500 parts by weight of a process oil consisting of at least one of paraffin, naphthenic and aromatic; 100 to 800 parts by weight of a filler made of at least one of calcium carbonate, talc and mica; 2,4-dichloro benzoyl peroxide, Dicumyl peroxide, and di- (2,4-dichlorobenzoyl) -peroxide (Di- (2,4- 0.5 to 7 parts by weight of a crosslinking agent consisting of a peroxide consisting of at least one of dichlorobenzoyl) -peroxide); 1 to 10 parts by weight of a crosslinking accelerator consisting of at least one of p-quinone dioxime and p-dibenzoylquinone dioxime; A thermoplastic elastomer composition for a dynamic crosslinked artificial turf comprising a resin stabilizer and 1 to 10 parts by weight of a pigment. delete delete delete