JP2581277B2 - Sand for artificial turf, method for producing the same, and artificial turf structure using the sand - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to artificial grass sand for providing a ground excellent in cushioning property, compression durability and flexibility, a method for producing the same, and an artificial grass structure comprising the sand. .

[Prior Art] Conventionally, it has been known that sand is scattered in the grass of artificial turf and used for sports grounds.

It is also known to sprinkle elastic resin particles or sand obtained by uniformly coating the elastic resin into the grass of artificial grass.

[Problems to be Solved by the Invention] However, the artificial turf ground to which the elastic resin uniform coating sand is sprayed has a fine filling, a low porosity, and eventually,
The cushioning properties were poor, the surface hardening phenomenon was rapid, and the elasticity retention period of the ground surface was short and insufficient.

The present invention has been made in view of the drawbacks of the conventional artificial grass containing sand,
An object of the present invention is to provide an artificial turf sand that can provide a soft ground that is excellent in cushioning property and that hardly causes surface hardening of the ground.

[Means for Solving the Problems] The present invention has achieved the above object by the following configuration.

That is, the sand for artificial turf of the present invention, on the surface of the sand, a resin containing an antiblocking agent, 0.5 to 0.5 to the sand.
The method is characterized in that it is attached in the range of 5% by weight.
The method is characterized in that sand, which has been dried and heated at a temperature of 50 ° C., is applied to a resin aqueous emulsion in the presence of an antiblocking agent while stirring the sand in a mixer.

The artificial turf structure of the present invention is characterized in that, in the artificial turf structure in which the grass is filled with sand, the sand has a surface to which a resin containing an antiblocking agent is adhered. [Function] Conventionally, there is a technique of filling a sand surface uniformly coated with a resin film into the grass of artificial turf, but even if such a technique is adopted, the cushioning property is one step away. I could only get what I was missing.

As a result of intensive studies on the problems of the prior art, the present invention shows that when a coating is formed with a specific resin composition containing an antiblocking agent, the coating is not uniformly coated on the entire surface, but is formed as a block (projection) as shown in FIG. ) Is formed. It has been found that such a resin adhesion form has an important function.

That is, the present invention has been completed by investigating the fact that if a lump-shaped (projection-shaped) resin film is fixed to the sand surface, it gives extremely high cushioning properties.

 The present invention will be described with reference to the drawings.

FIG. 1 is an enlarged photograph showing an example of the particle structure of the artificial grass sand of the present invention. FIG. 2 is a schematic diagram of FIG.

In FIG. 2, reference numeral 1 denotes a sand main body, and reference numeral 2 denotes a resin adhered to the surface of the sand in a lump (protruding, preferably partially).

FIG. 3 is an enlarged photograph showing the particle structure of sand (Comparative Example 1) uniformly coated with a resin coating outside the range of the present invention containing no antiblocking agent.

Comparing FIG. 1 and FIG. 2 with FIG. 3, it can be seen that the way of attaching the resin is clearly different. That is, in the sand of the present invention, the resin 2 adheres to the surface of the sand 1 in a projecting or lump shape.

In the sand of the present invention, the adhesion thickness of the resin is preferably about 3% or more, more preferably 4 to 15%, with respect to the particle diameter in the adhesion direction, so that the balance between cushioning property and durability can be obtained. Good.

As such a resin, a resin having excellent flexibility and flexibility, more preferably a resin having rubber elasticity, has excellent cushioning properties.

Such resins include, for example, SBR, NBR, CR,
Chloroprene synthetic rubber and natural rubber, acrylic resin, polyethylene-vinyl acetate copolymer resin, polyethylene-vinyl acetate-vinyl chloride copolymer resin, vinyl acetate-vinyl chloride copolymer resin, vinylden-acrylic copolymer A polymer resin, a urethane-based resin, or the like can be used, but is not limited thereto.

In the present invention, such a resin may be used as it is, but the use of a resin that is further crosslinked or vulcanized or a resin that has been modified into a self-crosslinking type gives sand excellent in cushioning property and durability. preferable.

As the cross-linking agent and vulcanizing agent, the agents used for each resin are different, but sulfur, zinc white, magnesium oxide, organic peroxide, isocyanate compound,
Commonly used compounds such as melamine compounds and epoxy compounds are used. Further, such a composition may be further blended with a drug usually blended in rubber, such as an antioxidant.

In addition, as the self-crosslinking resin, for example, those obtained by introducing a functional group such as a carboxyl group or a methylol group into the above-described various resins and modifying them can be used. For example, a modified resin having a carboxyl group introduced into SBR, methylolmelamine, or the like can be used.

In the present invention, such a resin is used in the form of an aqueous dispersion (emulsion). This aqueous resin emulsion is suitable for forming a film in a lump form on the surface of sand. In contrast,
A conventional resin solution cannot form a uniform coating and cannot achieve the effects of the present invention.

Further, a filler can be further added to the resin aqueous emulsion, whereby a stronger film can be formed. As such a filler, for example, calcium carbonate, aluminum hydroxide, carbon, clay and the like can be used.

When the sand is colored, the resin film can be colored using a usual pigment or dye.

The resin aqueous emulsion of the present invention contains an antiblocking agent in the resin in order to control the tackiness and the film forming property. Such an antiblocking agent is preferably contained in the resin in the range of 0.01 to 5% by weight, more preferably 1 to 3% by weight. In addition to such an anti-blocking agent, it is preferable to include a slippery substance such as wax. Such a slippery substance acts synergistically with the antiblocking agent and further contributes to the resin film in the form of a lump, both of which remain in the adhered resin.

The amount of the resin (including the anti-blocking agent) to be applied is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight based on the weight of the sand, from the viewpoint of satisfying the above-mentioned resin adhesion thickness. .

The particle size of the sand is not particularly limited, but a sand having a size of 0.15 to 1.7 mm (100 to 10 mesh) is preferably used for the ground.

Next, an example of the method for producing the artificial grass sand of the present invention will be described.

First, the sand is heated to 110 to 140 ° C. while being stirred with hot air heated to 300 to 500 ° C., and dried and preheated.

The heated sand is then transferred to a mixer, mixed with the above-mentioned aqueous emulsion of the resin while stirring, and further mixed with an anti-blocking agent.

As a mixer at this time, preferably 100 to 400 rp
m, more preferably 100-200 rpm, is good for partially adhering the resin coating. If the rotation is too fast, the resin film is easily broken, and the sand is crushed.If the rotation is too slow, the sand tends to stick, and in any case, the specific effect of being attached in a lump is achieved. Can not.

The resin aqueous emulsion is preferably 0.5 to 5%, more preferably 1 to 5% by weight of sand in terms of resin solid content.
It is applied in a range of 3%.

Further, the antiblocking agent is preferably used for sand.
It is mixed in the range of 0.01 to 5% by weight, more preferably 0.02 to 0.1% by weight.

Examples of such an antiblocking agent include higher fatty acids and salts thereof, such as stearic acid and calcium salts, lead salts, and zinc salts of stearic acid, waxes such as polyethylene wax and paraffin, esters of fatty acids and polyhydric alcohols and parts thereof. Esters, fatty acid amides, fatty acid ketones and the like can be used.
Among them, higher fatty acids and salts thereof are effectively excellent.

Such an anti-blocking agent acts synergistically with wax previously blended in the resin to bias the resin adhering to the sand surface.

The above mixer can be heated if necessary.
This heating may be any temperature required for crosslinking or vulcanization,
In some cases, it may be at room temperature, but preferably
A temperature of 80 ° C or higher is applied. By using such a specific mixer, the resin is an aqueous emulsion,
Preferably, the resin can be conveniently attached to the sand surface in a lump by a synergistic effect such as being a cross-linking type, being stirred, and the presence of a wax and an antiblocking agent.

The artificial turf structure of the present invention is obtained by filling the artificial grass turf with the sand for artificial turf.

The amount of such sand is not particularly limited, but preferably contains at least 30% by weight, more preferably 50% by weight or more of the total amount of sand, in order to utilize the function of the sand. Such sands can be used by being mixed with other sands and, of course, filled in layers.

The ground made of such an artificial turf structure has features of high porosity, excellent cushioning properties, and flexibility because the resin is partially adhered and is indefinite.

[Examples] Hereinafter, the present invention will be described with reference to Examples.

Examples 1 and 2 and Comparative Examples 1 and 2 A base was made of asphalt, and an artificial lawn on which a nylon film split yarn having a pile length of 19 mm and having a pile length of 19 mm was planted was laid on the base.

The following sand was sprayed on the artificial grass to a thickness of about 16 mm to form a ground.

First, 10 kg of sand (particle diameter: 0.3 to 1.2 mm) is heated to 130 ° C. by a dryer, and then transferred into a mixer rotating at a constant speed of 130 rpm, and a 46% aqueous emulsion of self-crosslinking-modified SBR (solids weight) 0.2 kg) to the sand under stirring and mix.
5 g was added and mixed.

The resin application amount of the obtained sand was 2% by weight, and as shown in FIG. 1, a lump of resin was adhered to the surface, and the adhesion thickness of the resin was about 9%.

Example 2 As Example 2, a resin-adhered sand was produced in the same manner as in Example 1 except that a normal SBR 46% aqueous emulsion having no functional group was used instead of the SBR of Example 1. This sand was sand to which the resin adhered in a lump as in Example 1.

As Comparative Example 1, a resin-fixed sand was formed in the same manner as in Example 1 except that a 46% resin solution of SBR dissolved in toluene was used without using an antiblocking agent. This sand is
As shown in FIG. 3, the particle image was whitish and was uniformly covered with the resin film.

 As Comparative Example 2, ordinary sand was prepared.

Table 1 shows the results after three months of practical use of a gland using these various sands.

As is clear from Table 1, the product of Example 1 was excellent in cushioning property and flexibility even after 3 months, but the product of Example 2 was not a crosslinked resin and was initially filled. The function was at the same level as in Example 1, but after three months, as shown in the table, the SBR fell off and was finely crushed, reducing the flexibility of the ground.

Compared to these examples, those of Comparative Examples 1 and 2 showed remarkably inferior results.

In the table, the cushioning property was evaluated by measuring the maximum acceleration (G) according to "Dynamic compression test method for cushioning material for packaging" of JIS Z-0235.

That is, a 3 kg square (2
A steel load of 0 × 20 cm) was held by a magnet, dropped naturally on a support on which a sample sand 30 cm below was placed, and the impact received by the load was converted into a maximum acceleration and evaluated. The sample sand is
A steel box with a constant thickness of 15 mm was used.

Flexibility: Compressive stress was measured and evaluated based on JIS A-1216 “Uniaxial compression test method for soil” (unit: kg / cm ² ).

[Effects of the Invention] The present invention is sand for providing a ground excellent in cushioning property and flexibility, and exhibits an excellent effect of not damaging feet and lower back by appropriate sliding and cushioning properties.

[Brief description of the drawings]

FIG. 1 is an enlarged photograph showing an example of the particle structure of the artificial grass sand of the present invention. FIG. 2 is a schematic diagram of FIG. FIG. 3 is an enlarged photograph showing the particle structure of sand having a uniform resin film obtained in Comparative Example 1. 1: Sand body 2: Resin

Claims (7)

(57) [Claims] 1. An artificial turf sand characterized in that a resin containing an antiblocking agent adheres to the surface of the sand in an amount of 0.5 to 5% by weight based on the sand. 2. The artificial turf sand according to claim 1, wherein the antiblocking agent is a higher fatty acid or a salt thereof. 3. An artificial turf for artificial turf characterized by applying a resin aqueous emulsion to a sand dried and heated at a temperature of 100 to 150 ° C. in the presence of an antiblocking agent while stirring the sand in a mixer. Sand production method. 4. The method for producing sand for artificial turf according to claim 3, wherein the aqueous resin emulsion contains a crosslinking agent or the resin is a self-crosslinking resin. 5. The method for producing sand for artificial turf according to claim 3, wherein the application amount of the resin aqueous emulsion is in the range of 0.5 to 5% by weight in terms of resin solid content with respect to the sand. 6. The method according to claim 3, wherein the amount of the antiblocking agent is 0.01 to 5% by weight based on the weight of the sand. 7. An artificial turf structure in which grass is filled with sand, wherein the sand has a surface to which a resin containing an anti-blocking agent is adhered. .