Composition for artificial turf backing, backing layer, and artificial turf

Abstract

The present invention provides a composition for creating a backing layer for artificial turf that can firmly fix the pile yarn and base fabric even when submerged in water, and is resistant to cracking even when exposed to low temperatures. [Solution] The artificial turf backing composition according to the present invention contains a polymer (A), a rosin ester (B), and a liquid medium (C), wherein the polymer (A) is a polymer having repeating units derived from a conjugated diene compound and repeating units derived from an aromatic vinyl compound, the glass transition temperature of the polymer (A) is in the range of -65 to +10°C, the softening point of the rosin ester (B) is +90°C or higher, and when the content of the polymer (A) is MA parts by mass and the content of the rosin ester (B) is MB parts by mass, the MB / MA value is 0.05 to 1.5.

Description

Technical Field

[0001] The present invention relates to a composition for artificial turf backing, a backing layer produced using the composition, and artificial turf provided with the backing layer.

Background Art

[0002] In recent years, artificial turf has been used as a substitute for natural turf in soccer fields, rugby fields, etc. In order to prevent the pile yarns implanted in the base fabric from falling out due to a load, a backing layer (hereinafter, also referred to as "backing layer") is provided on the back side. In the case of ordinary artificial turf, the backing layer is produced by applying a composition for artificial turf backing to the back surface of the base fabric and drying it (see, for example, Patent Document 1).

[0003] Generally, in order to further improve the durability of artificial turf, a composition for artificial turf backing contains synthetic rubber latex or the like (see, for example, Patent Document 2). By including synthetic rubber latex, the pile yarns and the base fabric can be fixed more firmly to prevent pile yarn shedding.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when artificial turf is exposed to rain and flooded, the fixing between the pile yarns and the base fabric tends to loosen. Therefore, not only is it necessary to firmly fix the pile yarns and the base fabric to prevent pile yarn shedding in the normal state, but it is also necessary to firmly fix the pile yarns and the base fabric even when artificial turf is exposed to rain and flooded.

[0006] Furthermore, because artificial turf is used outdoors in fields such as soccer and rugby, it can be exposed to low temperatures during the winter season. Conventional backing layers were prone to cracking when exposed to low temperatures.

[0007] Some aspects of the present invention provide compositions for creating a backing layer for artificial turf that can firmly fix the pile yarn and base fabric even when submerged in water, and that are less prone to cracking even when exposed to low temperatures. [Means for solving the problem]

[0008] One embodiment of the artificial turf backing composition according to the present invention is: It contains a polymer (A), a rosin ester (B), and a liquid medium (C), The polymer (A) is a polymer having repeating units derived from a conjugated diene compound and repeating units derived from an aromatic vinyl compound. The glass transition temperature of the polymer (A) is in the range of -65 to +10°C. The softening point of the rosin ester (B) is +90°C or higher. When the content of polymer (A) is MA parts by mass and the content of rosin ester (B) is MB parts by mass, the MB / MA value is 0.05 to 1.5.

[0009] In one embodiment of the artificial turf backing composition, The polymer (A) may also be carboxy-modified styrene-butadiene rubber (SBR).

[0010] In any embodiment of the artificial turf backing composition, The liquid medium (C) may be water.

[0011] In any embodiment of the artificial turf backing composition, Furthermore, it may contain at least one selected from the group consisting of heavy calcium carbonate, polymerized phosphates, silicones, and sodium polyacrylate.

[0012] One aspect of the backing layer according to the present invention is It is formed by applying and drying the artificial turf backing composition of any of the above aspects.

[0013] One aspect of the artificial turf according to the present invention is It includes the backing layer of the above aspect.

Advantages of the Invention

[0014] According to the artificial turf backing composition of the present invention, even when immersed in water, the pile yarn and the base fabric can be firmly fixed, and the backing layer of the artificial turf that is hardly cracked even when exposed to low temperatures can be produced.

Modes for Carrying Out the Invention

[0015] Hereinafter, preferred embodiments according to the present invention will be described in detail. It should be understood that the present invention is not limited only to the embodiments described below, but also includes various modifications implemented within the scope without changing the gist of the present invention.

[0016] In this specification, “(meth)acryl~” represents “acryl~” or “methacryl~”. Also, “~(meth)acrylate” represents “~acrylate” or “~methacrylate”.

[0017] In this specification, the numerical range described using “X~Y” means including numerical value X as the lower limit value and including numerical value Y as the upper limit value.

[0018] 1. Composition for Artificial Turf Backing The composition for artificial turf backing according to one embodiment of the present invention is a composition for producing a backing layer of artificial turf, which contains a polymer (A), a rosin ester (B), and a liquid medium (C). The polymer (A) is a polymer having a repeating unit derived from a conjugated diene compound and a repeating unit derived from an aromatic vinyl compound. The glass transition point of the polymer (A) is in the range of -65 to +10 °C. The softening point of the rosin ester (B) is 90 °C or higher. When the content of the polymer (A) is MA parts by mass and the content of the rosin ester (B) is MB parts by mass, the value of MB / MA is 0.05 to 1.5. Hereinafter, the components that can be contained in the composition for artificial turf backing according to the present embodiment will be described in detail.

[0019] 1.1. Polymer (A) The composition for artificial turf backing according to the present embodiment contains a polymer (A). The polymer (A) is preferably in the form of a latex dispersed as particles in the liquid medium (C). When the polymer (A) is in the form of a latex, the coating property of the composition for artificial turf backing on the base fabric of artificial turf is good, and the pile yarns implanted in the base fabric can be firmly fixed, which is preferable. 。

[0020] The polymer (A) is a polymer having a repeating unit derived from a conjugated diene compound and a repeating unit derived from an aromatic vinyl compound. Further, the glass transition point of the polymer (A) is in the range of -65 to +10 °C. When a polymer satisfying these conditions is commercially available, that polymer may be used. Also, when a polymer satisfying these conditions is commercially available as a latex dispersed as particles in a liquid medium, that latex may be used.

[0021] The content MA (parts by mass) of polymer (A) is preferably 20 parts by mass or more and 50 parts by mass or less, and more preferably 30 parts by mass or more and 40 parts by mass or less, when the total mass of the artificial turf backing composition is 100 parts by mass. It is preferable that the content of polymer (A) be within the above range, as this improves the applicability of the artificial turf backing composition to the artificial turf base fabric and allows for stronger fixation of the pile yarns planted in the base fabric.

[0022] Polymer (A) has repeating units derived from a conjugated diene compound and repeating units derived from an aromatic vinyl compound. Polymer (A) may also have other repeating units. The repeating units constituting polymer (A) will be described below.

[0023] 1.1.1. Repeating units constituting polymer (A) <Repeating units derived from conjugated diene compounds> The presence of repeating units derived from a conjugated diene compound in polymer (A) facilitates the production of polymers with excellent viscoelasticity and strength. Specifically, using a polymer with repeating units derived from a conjugated diene compound allows for strong bonding force to be imparted to the polymer. Because the polymer is given rubber elasticity derived from the conjugated diene compound, it can adapt to changes such as volume contraction and expansion of artificial turf exposed to wind, rain, and low temperatures, thereby improving durability.

[0024] Specific examples of conjugated diene compounds include, for example, 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and 2-chloro-1,3-butadiene, and one or more of these can be selected. 1,3-butadiene is particularly preferred as the conjugated diene compound.

[0025] The content of repeating units derived from the conjugated diene compound is preferably 30 to 60 parts by mass, and more preferably 40 to 55 parts by mass, when the total repeating units of polymer (A) are 100 parts by mass.

[0026] <Repeating units derived from aromatic vinyl compounds> Because polymer (A) has repeating units derived from aromatic vinyl compounds, it is possible to improve adhesion with pile yarns made from commonly used materials such as polyethylene, polypropylene, polyester, and polyamide, thereby improving the durability of artificial turf.

[0027] Specific examples of aromatic vinyl compounds include, for example, styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, chlorostyrene, and divinylbenzene, and one or more of these can be selected. Styrene is particularly preferred as the aromatic vinyl compound.

[0028] The content of repeating units derived from aromatic vinyl compounds is preferably 10 to 40 parts by mass, and more preferably 15 to 30 parts by mass, when the total repeating units of polymer (A) are 100 parts by mass.

[0029] <Other repeating units> Polymer (A) may have other repeating units besides those described above. Examples of other repeating units include repeating units derived from (meth)acrylate compounds, repeating units derived from unsaturated carboxylic acids, and repeating units derived from α,β-unsaturated nitrile compounds.

[0030] Specific examples of (meth)acrylate compounds include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, and methyl (meth)acrylate. Examples include syl, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, ethylene glycol (meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, allyl (meth)acrylate, ethylene di(meth)acrylate, and others, and one or more can be selected from these. Of these, it is preferable that one or more be selected from methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxymethyl (meth)acrylate, and hydroxyethyl (meth)acrylate, and it is particularly preferable that it be methyl (meth)acrylate or hydroxymethyl (meth)acrylate.

[0031] Specific examples of unsaturated carboxylic acids include mono- or dicarboxylic acids (anhydrides) such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, and itaconic acid, and one or more can be selected from these. In particular, one or more selected from acrylic acid, methacrylic acid, and itaconic acid is preferred.

[0032] Specific examples of α,β-unsaturated nitrile compounds include, for example, acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile, and vinylidene cyanide, and one or more of these can be selected. Of these, one or more selected from acrylonitrile and methacrylonitrile is preferred, and acrylonitrile is more preferred.

[0033] Furthermore, polymer (A) may further have repeating units derived from the following compounds. Examples of such compounds include fluorine-containing compounds having ethylenically unsaturated bonds, such as vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene; alkylamides of ethylenically unsaturated carboxylic acids, such as (meth)acrylamide and N-methylolacrylamide; vinyl carboxylate esters, such as vinyl acetate and vinyl propionate; acid anhydrides of ethylenically unsaturated dicarboxylic acids; monoalkyl esters; monoamides; aminoalkylamides of ethylenically unsaturated carboxylic acids, such as aminoethylacrylamide, dimethylaminomethylmethacrylamide, and methylaminopropylmethacrylamide, and one or more of these can be selected.

[0034] 1.1.2. Preparation of Polymer (A) The method for synthesizing polymer (A) is not particularly limited, and polymers produced by known manufacturing methods can be used. For example, polymers produced by the synthesis method described in Japanese Patent Application Publication No. 2008-088414 can be used.

[0035] Commercially available polymers (A) include, but are not limited to, the carboxy-modified SBR emulsions "SBL 2876" (glass transition temperature: -4°C), "SBL 0568" (glass transition temperature: -23°C), and "SBL 0548" (glass transition temperature: -49°C) manufactured by ENEOS Material Corporation, as well as the SBR emulsions "Smartex NSA-65D" (glass transition temperature: -25°C) and "Nalstar SR-116" (glass transition temperature: -28°C) manufactured by Nippon A&L Co., Ltd.

[0036] 1.1.3. Physical properties of polymer (A) <Glass transition temperature> The glass transition temperature of polymer (A) is in the range of -65 to +10°C, preferably in the range of -60 to +5°C, and more preferably in the range of -50 to 0°C. When the glass transition temperature of polymer (A) is within the above range, the pile yarn and the base fabric can be firmly fixed even when immersed in water, and a backing layer can be produced that is less prone to cracking even when exposed to low temperatures. The glass transition temperature of polymer (A) can be determined from the endothermic peak observed in the temperature range of -65 to +10°C when differential scanning calorimetry (DSC) is performed on polymer (A) in accordance with JIS K7121.

[0037] <Number average particle diameter> When the polymer (A) is in the form of latex dispersed as particles in a liquid medium (C), the number-average particle diameter of the polymer (A) is preferably in the range of 50 to 400 nm, and more preferably in the range of 100 to 250 nm. When the number-average particle diameter of the polymer (A) is within the above range, the applicability of the artificial turf backing composition to the artificial turf base fabric is improved, and the pile yarns planted in the base fabric can be fixed more firmly.

[0038] The number-average particle diameter of polymer (A) is the particle diameter (D50) at which the cumulative frequency of particles, when accumulated from smallest to largest, reaches 50%, measured using a particle size distribution analyzer that uses the light scattering method as its measurement principle. Examples of such particle size distribution analyzers include the Coulter LS230, LS100, LS13 320 (all manufactured by Beckman Coulter, Inc.) and the FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.). These particle size distribution analyzers can evaluate not only the primary particles of polymer (A) but also the secondary particles formed by the aggregation of primary particles.

[0039] 1.2. Rosin ester (B) The artificial turf backing composition according to this embodiment contains rosin ester (B). Since rosin ester (B) has excellent compatibility with polymer (A), good adhesion can be achieved when used in combination with polymer (A). Regardless of whether polymer (A) is water-dispersible or water-soluble, it is preferable that the rosin ester (B) used in combination is in the form of an emulsion.

[0040] The softening point of rosin ester (B) is +90°C or higher, preferably in the range of +90 to +200°C, and more preferably in the range of +100 to +180°C. When the softening point of rosin ester (B) is within the above range, the pile yarn can be sufficiently fixed even when the artificial turf is exposed to a large amount of moisture, thereby improving the durability of the artificial turf. The softening point of rosin ester (B) can be confirmed by a test method in accordance with JIS K5601.

[0041] As for rosin ester (B), polymerized rosin and polyhydric alcohol are esterified together. Examples include polymerized rosin esters obtained by this process, modified rosin esters obtained by esterifying modified rosin with a polyhydric alcohol, stabilized rosin esters, and disproportionated rosin esters. Among these, polymerized rosin esters and modified rosin esters are preferred. The polyhydric alcohol used in esterification is not particularly limited, and diethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexantriol, 1,2,4-butanetriol, pentaerythritol, etc. can be used.

[0042] Commercially available rosin esters (B) include, but are not limited to, products such as "Hariestar SK-370N" (softening point: 100°C), "Hariestar SK-816E" (softening point: 145°C), and "Hariestar SK-822E" (softening point: 170°C) from Harima Chemicals, Inc., and "Super Ester E-788" from Arakawa Chemical Industries, Ltd. Rosin esters (B) can be used individually or in combination of two or more types.

[0043] The content of rosin ester (B) in MB (parts by mass) is preferably 10 parts by mass or more and 30 parts by mass or less, and more preferably 15 parts by mass or more and 20 parts by mass or less, when the total mass of the artificial turf backing composition is 100 parts by mass. When the content of rosin ester (B) is within the above range, the pile yarn can be fixed more firmly even when the artificial turf is exposed to a large amount of moisture, and the durability of the artificial turf can be further improved.

[0044] Furthermore, the ratio MB / MA of the rosin ester (B) content to the polymer (A) content MA (parts by mass) of the artificial turf backing composition according to this embodiment is 0.05 or more and 1.5 or less, preferably 0.1 or more and 1.3 or less, and more preferably 0.3 or more and 1.1 or less. When MB / MA is within the above range, a good balance is achieved between the adhesion provided by the polymer (A) and the water resistance provided by the rosin ester (B), making it possible to create a backing layer in which the pile yarn is firmly fixed even when submerged in water.

[0045] 1.3. Liquid media (C) The artificial turf backing composition according to this embodiment contains a liquid medium (C). Preferably, the liquid medium (C) is an aqueous medium containing water. The aqueous medium may also contain a non-aqueous medium other than water. Examples of such non-aqueous media include amide compounds, hydrocarbons, alcohols, ketones, esters, amine compounds, lactones, sulfoxides, and sulfone compounds, and one or more selected from these can be used. When the liquid medium (C) contains water and a non-aqueous medium other than water, it is preferable that 90% or more by mass of the total amount of liquid medium (C) is water, and more preferably 98% or more by mass is water. By using an aqueous medium as the liquid medium (C) in the artificial turf backing composition according to this embodiment, the degree of adverse impact on the environment is reduced, and the safety for handling workers is also increased.

[0046] The proportion of non-aqueous media contained in the aqueous media is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably substantially absent, per 100 parts by mass of aqueous media. Here, "substantially absent" means that non-aqueous media are not intentionally added as a liquid medium, and may include non-aqueous media that are inevitably mixed in when preparing the composition for artificial turf backing.

[0047] 1.4. Other Additives The artificial turf backing composition according to this embodiment may optionally contain additives other than the polymer (A), rosin ester (B), and liquid medium (C) described above. Such additives include, for example, bulking agents such as heavy calcium carbonate and dispersion agents such as polymerized phosphates. Examples of known additives include antifoaming agents such as silicones, thickeners such as sodium polyacrylate, and known additives described in Japanese Patent Publication No. 2008-088414.

[0048] 1.5. Method for producing a composition for artificial turf backing The artificial turf backing composition according to this embodiment can be manufactured by mixing the aforementioned components with additives as needed. This mixing can be carried out by stirring using known methods, for example, by mixing at a temperature of 5 to 40°C using a mixer such as a line blender, kneader, blender, or universal mixing and stirring machine to obtain the artificial turf backing composition.

[0049] 2.Artificial grass The backing layer according to one embodiment of the present invention is formed by applying and drying the above-described artificial turf backing composition. Furthermore, the artificial turf according to one embodiment of the present invention is equipped with the above-described backing layer. Specifically, the artificial turf according to this embodiment comprises an artificial turf base fabric having a base fabric and a large number of pile yarns arranged on one side of the base fabric, and a backing layer formed by applying and drying the above-described artificial turf backing composition on the other side of the base fabric. As a result, the artificial turf manufactured using the above-described artificial turf backing composition maintains the pile yarns arranged on the base fabric in good condition and exhibits high pile yarn pull-out strength in both normal and water-immersion treatment conditions. In addition, it has the advantage of a long life cycle because it is equipped with a backing layer that is less prone to cracking even at low temperatures. Therefore, the artificial turf manufactured using the above-described artificial turf backing composition is effective for use in stadiums and the like where strenuous sports are played.

[0050] The artificial turf described above can be manufactured, for example, as follows: First, a large number of pile threads are planted in a base fabric to form an artificial turf base fabric. Then, the artificial turf backing composition described above is applied to the back surface of the base fabric. The amount of artificial turf backing composition applied is 100 to 1500 g / m² based on dry mass. 2 It is preferable to use 150-1300 g / m². 2 It is more preferable to apply 100g / m². 2 If the strength is less than 1500g / m, the pile yarn pull-out strength of the resulting backing layer tends to be insufficient. 2If the temperature is too high, the backing layer tends to become under-dried due to excessive coating. After coating, heat drying should be performed at 90-110°C. Heating temperatures below 90°C tend to result in insufficient drying. On the other hand, temperatures above 110°C tend to cause the pile yarn to shrink. The heating time is preferably 5-40 minutes, depending on the heating temperature. Once drying is complete, artificial turf can be obtained. The base fabric can be made from materials such as polypropylene (PP) or felt. The pile yarn can be made from materials such as polyethylene, polypropylene, or nylon.

[0051] 3. Examples The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" and "%" are based on mass unless otherwise specified.

[0052] 3.1. Example 1 3.1.1. Preparation of compositions for artificial turf backing Polymer (A): 100 parts by mass of SB-1 (manufactured by ENEOS Material Corporation, product name "SBL 2876", glass transition temperature: -4℃, carboxy-modified SBR emulsion); Rosin ester (B): 50 parts by mass of TF-1 (manufactured by Harima Chemicals, Inc., product name "Hariestar SK-370N", softening point: 100℃); Heavy calcium carbonate (manufactured by Bihoku Funka Kogyo Co., Ltd., product name "BF300"): 150 parts by mass; Polyphosphate (manufactured by Yoneyama Chemical Co., Ltd., product name "Sodium Tripolyphosphate"): 0.15 parts by mass; Silicone (manufactured by Shin-Etsu Chemical Co., Ltd.) A composition for artificial turf backing was prepared by mixing 0.5 parts by mass of (manufactured by Toagosei Co., Ltd., product name "KM-72") and 4.5 parts by mass of sodium polyacrylate (manufactured by Toagosei Co., Ltd., product name "Aron A7075") at room temperature for 10 minutes using a stirrer (manufactured by Yamato Scientific Co., Ltd., model number "LR500B"). The softening point of rosin ester (B) was measured according to the test method in accordance with JIS K5601.

[0053] 3.1.2. Production of artificial turf Artificial turf base fabric was prepared by planting 70mm polyethylene pile yarns (manufactured by Hagiwara Industries Co., Ltd., product name "Marufren") onto a polypropylene base fabric (manufactured by Hagiwara Industries Co., Ltd., product name "Primary Backing Cloth"). After drying, 500g / m² of the base fabric was applied to the side of the base fabric opposite to the side on which the pile yarns were planted. 2 The artificial turf backing composition prepared above was applied to the specified amount. Then, the mixture was heated and dried at 110°C for 40 minutes to produce artificial turf.

[0054] 3.1.3. Evaluation Method <Evaluation of suture removal strength> The artificial turf prepared as described above was left for 24 hours in an atmosphere of 50% relative humidity and 23°C. Afterwards, the pile threads were removed using an Autograph (model number "AGS-X", manufactured by Shimadzu Corporation) at a tensile speed of 100 mm / min, and the force required to remove each pile thread was calculated to evaluate the removal force under normal conditions.

[0055] Meanwhile, the artificial turf prepared as described above was immersed in 23°C water for 24 hours. Subsequently, the pile threads were removed using an Autograph (model number "AGS-X", manufactured by Shimadzu Corporation) at a tensile speed of 100 mm / min, and the force required to remove each pile thread was calculated to evaluate the thread removal force after the water immersion treatment.

[0056] If the thread removal force is 50N or higher in both the normal state and after water immersion treatment, the product is considered good as it can be used for practical purposes. On the other hand, if the thread removal force is less than 50N in either the normal state or after water immersion treatment, or both, the product is considered poor as it lacks durability and cannot be used for practical purposes.

[0057] <Evaluation of cracking in the backing layer at low temperatures> The artificial turf prepared as described above was placed in an incubator (manufactured by Yamato Scientific Co., Ltd., model number "IN804") set to 0°C for 24 hours. Immediately after removing it from the incubator, it was folded, and the presence or absence of cracks in the backing layer was evaluated. The evaluation criteria are shown below. A: The backing layer doesn't crack even when bent. B: When folded, the backing layer cracks.

[0058] 3.2. Examples 2-6, Comparative Examples 1-7 In Example 1, an artificial turf backing composition was prepared in the same manner as in Example 1, except that the polymer and rosin ester used in the composition were of the types and amounts shown in Table 1 or Table 2 below. Artificial turf was then produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2 below.

[0059] [Table 1]

[0060] [Table 2]

[0061] The following products or reagents were used for each component in Tables 1 and 2 above. <polymer> • SB-1: Manufactured by ENEOS Material Corporation, product name "SBL 2876", glass transition temperature: -4℃, carboxylated SBR emulsion • SB-2: Manufactured by ENEOS Material Corporation, product name "SBL 0568", glass transition temperature: -23℃, carboxylated SBR emulsion • SB-3: Manufactured by ENEOS Material Corporation, product name "SBL 0548", glass transition temperature: -49°C, carboxylated SBR emulsion • SB-4: Manufactured by ENEOS Material Corporation, product name "SBL 0597C", glass transition temperature: 28°C, carboxylated SBR emulsion <Rosin ester> • TF-1: Manufactured by Harima Chemicals Co., Ltd., product name "Hariestar SK-370N", softening point: 100℃ • TF-2: Manufactured by Harima Chemicals Co., Ltd., product name "Hariestar SK-816E", softening point: 145℃ • TF-3: Manufactured by Harima Chemicals Co., Ltd., product name "Hariestar SK-822E", softening point: 170℃ • TF-4: Manufactured by Harima Chemicals Co., Ltd., product name "Hariestar SK-385NS", softening point: 85℃

[0062] As shown in Table 1 above, it was found that by using the artificial turf backing compositions of Examples 1 to 6, the pile yarns and base fabric can be firmly fixed even when subjected to water immersion treatment, and a backing layer that is less prone to cracking even when exposed to low temperatures can be produced. On the other hand, as shown in Table 2 above, when the artificial turf backing compositions of Comparative Examples 1 to 7 were used, the durability of the backing layer decreased, and the pile yarns and base fabric could not be firmly fixed. This tendency was particularly pronounced when subjected to water immersion treatment. Furthermore, as shown in Table 2 above, it was found that when the artificial turf backing compositions of Comparative Examples 1 to 4 and 6 were used, cracks occurred in the backing layer when exposed to low temperatures.

[0063] The present invention is not limited to the embodiments described above, and various modifications are possible. The present invention encompasses configurations that are substantially identical to those described in the embodiments (for example, configurations with the same function, method, and result, or configurations with the same purpose and effect). The present invention also encompasses configurations in which non-essential parts of the configurations described in the embodiments are replaced with other configurations. Furthermore, the present invention also encompasses configurations that produce the same effects or achieve the same purpose as the configurations described in the embodiments. Furthermore, the present invention also encompasses configurations that add known technology to the configurations described in the embodiments.

Claims

1. It contains a polymer (A), a rosin ester (B), and a liquid medium (C), The polymer (A) is a polymer having repeating units derived from a conjugated diene compound and repeating units derived from an aromatic vinyl compound. The glass transition temperature of the polymer (A) is in the range of -65 to +10°C. The softening point of the rosin ester (B) is +90°C or higher. When the content of the polymer (A) is MA parts by mass and the content of the rosin ester (B) is MB parts by mass, the MB / MA value is 0.05 to 1.

5. Composition for backing artificial turf.

2. The artificial turf backing composition according to claim 1, wherein the polymer (A) is carboxy-modified styrene-butadiene rubber (SBR).

3. The artificial turf backing composition according to claim 1 or claim 2, wherein the liquid medium (C) is water.

4. Furthermore, the artificial turf backing composition according to claim 1 or claim 2 comprises at least one selected from the group consisting of heavy calcium carbonate, polymerized phosphate, silicone, and sodium polyacrylate.

5. A backing layer formed by applying and drying the artificial turf backing composition according to claim 1 or claim 2.

6. Artificial turf comprising the backing layer described in claim 5.

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