JPH09228308A - Sand packed elastic structure and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a sand packed elastic structure, by which it is possible to effectively prevent particles of rubber chips from being easily separated and broken, the water permeability, slidability and resistivity to combustibility, can be improved by scattering dry sand of 0.5mm-3mm on a projecting and recessed surface of a protective layer, and a structure of high durability can be obtained. SOLUTION: A sand packed elastic structure is so constructed that an elastic layer 3 obtained by binding rubber chips 2 by a binder such as an urethane resin, is formed on a basement on which crushed stones are spread, or asphalt concrete is placed, a projecting and recessed protective layer 4 comprising an urethane resin composition having thixo property and quick hardenability, is formed on the surface of the elastic layer 3, and the projecting and recessed protective layer 4 is filled with a designated amount of sand, to form a sand layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand-filled elastic structure and a method for manufacturing the same, and more particularly to a pavement structure for indoor or outdoor exercise facilities such as tennis courts, valley courts, basketball courts, and athletic fields. In the elastic structure), a sand-containing elastic structure which protects an uneven surface of an elastic layer formed by binding rubber chips with a binder, and improves the slidability and durability of the elastic structure, and a method for manufacturing the same It is a thing.

[0002]

2. Description of the Related Art Conventionally, as a pavement structure (elastic structure) for indoor or outdoor sports facilities such as tennis courts, valley courts, basketball courts, athletic fields, etc., for example, rubber chips are bound by a binder on a base. An elastic layer is formed, and a grain size of 0.1 mm is formed on the uneven surface of the elastic layer.
An invention of a pavement structure for a sand-filled rubber chip exercise facility floor filled with the above dry sand and having water permeability and slidability has been proposed (Japanese Patent Laid-Open No. 60-238564).

[0003]

However, in the conventional pavement structure as described above, since the dry sand is directly filled on the rubber chip layer, the state where the sand is placed is unstable and the sand is easy to move. , If the sand further moves and the surface of the rubber chip layer is exposed, the strength of the tip of the rubber chip layer and the adhesive strength are unstable, and the particles of the rubber chip where the leg force and the force of the sand act are peeled off, There was a problem that it would break and come off.

The present invention has been devised in view of such a conventional problem, and forms and protects the surface of an elastic layer composed of a rubber chip by forming an uneven protective layer composed of a urethane resin composition and particles. 0.5 mm to 3 mm on the uneven surface of the layer
It is intended to provide a sand-filled elastic structure capable of being filled with dry sand to give water permeability and slidability, improve resistance to combustibility, and have a structure with excellent durability, and a manufacturing method thereof. It is what

[0005]

In order to achieve the above object, the present invention forms an elastic layer formed by binding rubber chips with a binder on a substrate, and comprises a urethane resin composition on the surface of the elastic layer. The gist of the invention is to form an uneven protection layer and form a sand layer by filling a predetermined amount of sand on the uneven protection layer.

The urethane resin composition for forming the protective layer is a resin (A) having a hardness (JIS A type) of 50 or more after curing, and a thixotropy index of 2.0 to.
5.0, viscosity 5,000-50,000 CPS (@ 20
(° C.) is preferable. Further, the urethane resin composition (A) is added with an organic or inorganic granular material (B) having a particle size of 1 to 8 mm in an amount of 5 to 100 when (B) is organic, relative to 100 parts of (A). Parts, and in the case of inorganic materials, they are mixed at a ratio of 20 to 200 parts, and the thixotropy index of this mixture is 2.5 to 6.0 and the viscosity is 5,000 to 5.
It is preferably 10,000 CPS (@ 20 ° C.).

The coating amount of the protective layer is 1 to 3 kg / m ²
Is preferred. The average particle diameter of the sand of the sand layer formed on the uneven protection layer is 0.5 mm to 3 mm, and the urethane resin composition forming the protection layer was mixed with inorganic or organic particles. It is something that uses things.
Further, it is preferable that the sand scattered on the uneven protective layer is filled up to the height of the protrusion of the protective layer.

The present invention is constituted as described above, and is formed by laminating an elastic layer in which vulcanized rubber chips having a particle size of 1 to 6 mm are bonded with a binder on a substrate, and the surface of the elastic layer is
A urethane resin composition having thixotropy is sprayed to form a protective layer, and the average particle size is formed on the uneven protective layer.
A sand layer is formed by filling sand of 0.5 mm to 3 mm.

Further, by mixing the urethane resin composition with a material such as an inorganic and / or organic granular material and spraying the mixture on the surface of the elastic layer, the unevenness of the urethane protective layer can be further increased. Therefore, the sand layer can be thickened.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a cross-sectional view of a sand-containing elastic structure embodying the present invention. The sand-containing elastic structure is composed of crushed stones and a rubber chip 2 in 100 parts on a base 1 on which water-permeable ascon is cast. On the other hand, the elastic layer 3 is formed by mixing and curing with 25 parts of a binder (not shown) of a one-component moisture-curable urethane resin, and the elastic layer 3 is formed.
A mixture of 60 parts of EPDM granules having an average particle size of 3.0 mm and 300 parts of a urethane resin composition on the surface 3a of the above, has a thixotropy index of 3.5 and a viscosity of 42,000.
The protective layer 4 is formed by spraying a mixture of 0 CPS, and the sand layer 6 is formed on the irregular protective layer 4 by filling silica sand having an average particle diameter of 1.0 mm to the top of the convex of the protective layer.

The elastic layer 3 is similar to that of the prior art in that the vulcanized rubber chips 2 having a particle size of about 1 to 6 mm are used in a weight ratio of about 2: 1 to a binder such as a urethane resin composition.
Mix in a ratio of 20: 1, preferably in the range 4: 1 to 8: 1. This mixture is laid on the base 1 so as to have a thickness of 6 to 20 mm, preferably 7 to 10 mm. In addition, the void ratio between the vulcanized rubber chips 2 is such that minute voids of 20 to 40% exist.

The thixotropy index of the urethane resin composition forming the protective layer 4 is 2.0-5.
Those having 0 and a viscosity of 5,000 to 50,000 are preferable. Furthermore, the average particle size of the dry sand 5 to be filled on the uneven protection layer 4 is preferably 0.5 mm to 3 mm,
If it is less than 3 mm, the water content of the sand itself is impaired and the water permeability deteriorates, and if it is more than 3 mm, suitable slidability cannot be exhibited.

As a construction method of the elastic structure containing sand as described above, a vulcanized rubber chip 2 having a particle size of 1 to 6 mm and a urethane resin on a base 1 on which crushed stones are spread or concrete is placed as described above. The elastic layer 3 bound by a binder such as a composition is 6 to 20 mm, preferably 7 to 10 mm
It is constructed by laying so as to have the thickness of. Then, a urethane resin composition having a thixotropy is sprayed onto the surface 3a of the elastic layer 3 to form a concavo-convex protective layer 4, and an average particle size of 0. 5mm-3mm sand 5
To form a sand layer 6.

Next, FIG. 2 is a sectional view showing a second embodiment of the present invention. In this embodiment, a urethane resin composition is used as a material for the protective layer 4, and an inorganic or organic granular material is used. A mixture of the objects 4a is used and sprayed onto the surface 3a of the elastic layer 3 to form the uneven protection layer 4. As an inorganic material, for example, a particle size of 1 to 6 mm
Silica sand, silica stone or hollow filler is used, and as the organic material, polyurethane with a particle size of 1 to 6 mm, EPD
A granular material such as M is used.

Further, the convex portion of the protective layer 4 of the urethane resin composition having a thixotropy which is sprayed onto the elastic layer 3 as described above, or the protective layer 4 in which the inorganic and / or organic granular material 4a is mixed. The height of the concave portion and the concave portion is usually 6 mm or less. As described above, the protective layer 4 made of urethane resin or the like having a thixotropy, which is sprayed onto the uneven elastic layer 3,
Alternatively, inorganic and / or organic powders and particles 4a
To form a sand layer 6 by filling the surface thereof with sand 5 and a sand layer 6 formed by directly filling sand 5 on the uneven elastic layer 3 as in the prior art. Was compared at the same place of use. As a result of observing the surface condition of the elastic structure after 6 months, a rubber chip was missing in the conventional structure and a large number of dents were generated, but the dent of the structure of the present invention was not seen and the durability was improved. Was found to improve.

[0016]

【Example】

[Example 1]. Construction of the rubber chip layer Spray the isocyanate primer on the permeable Ascon substrate. Next, 100 parts of vulcanized rubber chips having a particle diameter of 1 to 3 mm were well kneaded with 25 parts of a moisture-curable urethane 1-liquid type binder, and uniformly applied on the base with a dedicated compacting machine so as to have a thickness of 8 mm. did. . Composition for Urethane Protective Layer Main ingredient: Polyoxypropylene glycol having an average molecular weight of 1000 and 3000 and a slight excess of tolylene diisocyanate were reacted by a conventional method to obtain a urethane prepolymer having 5.2% free NCO groups. Curing agent: methylene-o-dichloroaniline 12 parts, polyoxypropylene glycol 15 having an average molecular weight of 3000
Parts, pigment 8 parts, plasticizer DOP 33 parts, heavy calcium carbonate 54 parts, finely divided calcium carbonate 42 parts, ultrafine silica 8
Parts, 4 parts of antioxidant, 2 parts of catalyst, and 22 parts of xylene were dissolved and mixed to obtain a uniform product. Mixture: A mixture of 100 parts of this main ingredient and 200 parts of a curing agent had a viscosity of 30,000 CPS at 20 ° C and a chicken tropy index of 3.2. . Spraying the urethane protective layer 100 parts of the urethane protective layer composition base agent, curing agent 2
75 parts of urethane rubber granules having an average particle size of 1.5 mm and a hardness of 65 are added to and mixed with 00 parts, and the mixture is mixed on the rubber chip layer described above with a spraying apparatus Structur Matic S100p of Germany SMG Company at 1.8 kg / m ² . Sprayed evenly. . Laying of sand On the urethane protective layer, silica sand with an average particle diameter of 0.8 mm and rake were laid evenly up to the top of the urethane protective layer protrusion.

[Example 2] Example 1 on the rubber chip layer.
EPDM rubber 6 having an average particle diameter of 3.0 mm and a hardness of 60 with respect to 300 parts of the main component of the urethane protective layer composition and the curing agent
After 0 parts were added and mixed, the mixture was uniformly sprayed at 1.8 kg / m ² by the same method. After curing, silica sand having an average particle size of 1.0 mm was uniformly laid by rake up to the height of the top of the urethane protective layer protrusion.

[Example 3] Example 1 on the rubber chip layer.
To 300 parts of the main component for the urethane protective layer composition and 300 parts of the curing agent, 90 parts of ceramic balls having an average particle diameter of 4 mm and well mixed were sprayed uniformly to 2.3 kg / m ² by the same method. After curing, silica sand having an average particle size of 1.5 mm was laid evenly with a rake to the height of the top of the urethane protective layer protrusion.

Example 4 Example 1 was formed on the rubber chip layer.
Pattern of irregularity of the ball blown shape to the protective layer is made as uniformly sprayed larger by the same method urethane protecting layer composition of claim base solution and only hardener at 1.5 kg / m ^2. After curing, silica sand having an average particle size of 1.0 mm was uniformly laid with a rake up to the height of the top of the urethane protective layer protrusion. [Comparative Example 1] Silica sand having an average particle size of 1.5 mm was laid directly on the rubber chip layer by a rake of 3 kg per m ^{2 so} as to be as uniform as possible. [Comparative Example 2] Example 1 on the rubber chip layer. To 300 parts of the main component of the urethane protective layer composition and 300 parts of the curing agent, 75 parts of urethane rubber granules having an average particle size of 1.5 mm and a hardness of 65 are added and mixed well, and 1.8 kg / m is obtained by the same method. Sprayed evenly at ² . No sand layer was laid.

As a result of performing playability (sensory test) with respect to the average particle diameter of the sand 5 filling the surface of the protective layer 4 of the urethane resin composition, the results shown in Table 1 could be obtained. In other words, the test conditions are as follows: Evaluation content: 20 runs, kicking, easy running, easy stopping, 4 grades: good (○), normal (△), not good (×) It was evaluated by. Number of players: 20

[0021]

[Table 1] * 1) Grains were removed during the sensory test. * 2) Sand disappeared in places with a lot of foot movement. * 3) Sand entered the voids of the rubber chip layer, and the amount of sand decreased. * 4) The part where the sand is gone has poor slidability and sudden braking is applied. * 5) It becomes slightly defective due to clogging. As is clear from Table 1, except for the impossibility, the average particle size of sand 5 is 0.5 mm to 3 mm. It was found that the playability (sensory test) was good when the No. 5 sand was sprayed.

[0022]

As described above, according to the present invention, an elastic layer formed by binding rubber chips with a binder is formed on a substrate as described above, and an uneven protective layer made of a urethane resin composition is formed on the surface of the elastic layer. Then, since a predetermined amount of sand was sprinkled on the uneven protection layer to form a sand layer, the following excellent effects are exhibited. (A) Since the load bearing point of the player's shoes mainly serves as the protrusion of the protective layer, the movement of the sand is small with respect to the movement of the player, and therefore the thickness of the sand is stable, and the maintenance of the surface by the brush is minimal. It can be maintained in a stable state in the time of. (B) Since the sand of the protective layer maintains a stable thickness, the sand is not exposed on the surface of the rubber chip layer (elastic layer), and the surface of the rubber chip layer is covered and protected by the protective layer. It is possible to prevent the rubber chips from falling off, resulting in a structure with excellent durability. (C) Since the protective layer is a mixture of a urethane resin composition having thixotropy and granules, it is necessary to adjust the coating amount to form a water-permeable structure without peeling off some of the surface openings of the rubber chip layer (elastic layer). You can At the same time, since the periphery of the granular material is thickly covered with the urethane resin composition, the gripping property (body detachability) of the granular material is improved and the structure has excellent durability. (D) The sand layer on the surface provides a proper sliding property and braking property with the player's shoes, and good playability is obtained, and at the same time, the biggest drawback of this type of pavement material is cigarettes, fire, etc. Resistance to the flammability of
Further, it is possible to prevent adhesion of dust, gum and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sand-filled elastic structure showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a sand-containing elastic structure showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Base 2 Rubber Chip 3 Elastic Layer 3a Surface of Elastic Layer 4 Concavo-convex Protective Layer 5 Sand 6 Sand Layer

Claims (5)

[Claims] 1. An elastic layer formed by binding rubber chips with a binder is formed on a base, and a surface of the elastic layer is formed.
Forming a concave-convex protective layer made of a urethane resin composition,
An elastic structure containing sand, characterized in that a sand layer is formed by spraying a predetermined amount of sand on the uneven protection layer. 2. The sand-containing elastic structure according to claim 1, wherein the sand layer formed on the uneven protection layer has an average particle diameter of sand of 0.5 mm to 3 mm. 3. The sand-containing elasticity according to claim 1 or 2, wherein the urethane resin composition forming the protective layer is mixed with inorganic or organic particles and the sand layer thickness is 2 to 10 mm. Structure. 4. An elastic layer formed by laminating a vulcanized rubber chip having a particle size of 1 to 6 mm on a substrate and binding it with a binder,
A urethane resin composition having thixotropy is sprayed on the surface of the elastic layer to form an uneven protective layer, and the uneven protective layer is filled with sand having an average particle size of 0.5 mm to 3 mm. A method for manufacturing a sand-containing elastic structure for forming a sand layer. 5. The method for producing a sand-containing elastic structure according to claim 4, wherein the urethane resin composition is mixed with inorganic and / or organic particles and sprayed onto the surface of the elastic layer.