JPH0681306A - Elastic pavement body - Google Patents

Abstract

PURPOSE:To improve the performance and execution property by forming a liquid urethane resin layer applied with the rocking property on a urethane prepolymer elastic body layer mixed with vulcanized rubber chips and having the specific composition, and specifying the layer thicknesses. CONSTITUTION:An elastic body mixed with urethane prepolymer of 20-60 pts.wt. at the ratio of 2-3.5 between the isocyanate group and hydroxyl group to vulcanized rubber chips of 100 pts.wt. having the mesh grain size of 3-20 is installed at the thickness of 5-50 mm as a nonslip lower layer for paving a field athletic facility. A liquid urethane resin applied with the rocking property by colloidal silica is sprayed on it to form a urethane resin layer having irregularities of 1-3mm in height. The execution can be completed with the simple work in a short period at a low cost, plugging of a spray gun can be prevented because no rubber chip is sprayed for execution, and rounded irregularities having little possibility of injuries can be easily formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-water-permeable elastic pavement used in athletics fields, multipurpose playing fields, tennis courts, volley courts and the like.

[0002]

2. Description of the Related Art Conventionally, an all-weather elastic pavement made of urethane resin has been used for athletics and exercise. Here, since the surface of this elastic pavement is smooth and slippery, the pavement surface is subjected to uneven finishing so as to adapt to the corresponding competition and exercise and prevent the athlete from slipping.

For example, JP-A-2-27003 and JP-A-3-27003.
In each publication of 96504, an elastic layer is formed on a floor slab, and a pavement material layer containing granular rubber chips is spray-coated on the elastic layer to form unevenness on the surface of the elastic pavement to improve slip resistance. A method of constructing a given elastic pavement is disclosed. However, in this construction method, since the elastic layer containing the granular rubber chips is sprayed by spray coating,
There is a problem that the spray gun (nozzle) is clogged by the rubber tip and the workability is poor.

Further, Japanese Patent Publication No. 56-40205 discloses that after the floor slab is provided with urethane pavement to make the surface smooth,
A method of finishing a urethane resin pavement surface by spraying a thixotropic curable urethane resin composition to form fine irregularities on the surface is disclosed. However, when using this finishing method for tracks for track and field, etc., it is difficult to construct urethane pavement to the required thickness at once due to the planned slope of the construction surface, and several layers It is necessary to re-apply, and it takes time and effort for construction. In addition, on-site construction type urethane is a liquid before curing, and is washed away at a steep slope such as a slope, which makes the construction difficult.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to carry out a simple construction in a short period of time without causing a clogging of a spray gun for applying a urethane resin. At a high quality athletic field,
An object of the present invention is to provide an elastic pavement capable of obtaining a multipurpose playing field, a tennis court and the like.

[0006]

In order to achieve the above object, the present invention provides an isocyanate compound and a polyol compound in a ratio of an isocyanate group and a hydroxyl group to 100 parts by weight of a vulcanized rubber chip having a particle size of 3 to 20 mesh. Gives thixotropic properties on an elastic body layer having a thickness of 5 to 50 mm, which is obtained by mixing 20 to 60 parts by weight of a urethane prepolymer obtained by mixing so as to have an isocyanate group / hydroxyl group = 2 to 3.5. 1-3 mm in height due to liquid urethane resin
There is provided an elastic pavement formed by forming a urethane resin layer having unevenness.

Hereinafter, the elastic pavement of the present invention will be described in detail. The elastic pavement of the present invention, as a lower layer of a urethane resin layer having irregularities for preventing slippage, etc., has a ratio of isocyanate groups to hydroxyl groups of 100 parts by weight of vulcanized rubber chips having a particle size of 3 to 20 mesh. / Hydroxyl group = 2 to 3.5 urethane prepolymer 20 to 6
It has an elastic layer formed by mixing 0 parts by weight. The elastic pavement of the present invention has such an elastic body layer as the lower layer of the urethane resin layer having irregularities, so that a steep gradient (0
Elastic pavement can be constructed even on slopes of up to 60 °,
It has the advantage that it can be finished to the target thickness at once.

Various known vulcanized rubber chips can be used, and examples thereof include crushed used tires and crushed used conveyor belts.

As such a vulcanized rubber chip, one having a particle size of 3 to 20 mesh is used. If the particle size of the vulcanized rubber chips is less than 6 mesh, the rubber particles are small, and the hollow part formed by the particles-particles in the urethane prepolymer is lost, which causes inconveniences such as swelling. If the particle size of the vulcanized rubber chips exceeds 12 mesh, the rubber particles are too large, and there are few particle indirect points per unit, so that it is not possible to obtain the physical strength of the elastic body. As the vulcanized rubber chips, those having a particle size of 6 to 12 mesh are more preferably used.

The elastic layer is formed by mixing 20 to 60 parts by weight of urethane prepolymer with 100 parts by weight of this vulcanized rubber chip. This urethane prepolymer is
It is a usual urethane prepolymer obtained from an isocyanate compound and a polyol, but the ratio of the isocyanate group to the hydroxyl group is isocyanate group / hydroxyl group = 2-3.
It is 5. If the number of isocyanate groups / hydroxyl groups is less than 2, the prepolymer will gel, and if it exceeds 3.5, it causes problems such as causing foaming. The amount ratio of the isocyanate group and the hydroxyl group is more preferably about 2 to 2.5 of the isocyanate group / hydroxyl group.

The isocyanate compound and the polyol used in the urethane prepolymer are not particularly limited and may be the same as ordinary urethane prepolymers. TD
I), hexamethylene diisocyanate (HMDI),
Suitable examples include diphenylmethane diisocyanate (MDI). On the other hand, suitable examples of the polyol include polyethylene glycol (P.E.G.) and polypropylene glycol (P.P.G.).

In the elastic layer, the vulcanized rubber chip 100
The amount of urethane prepolymer is 20 to 60 parts by weight.
Parts by weight. If the amount of urethane prepolymer is less than 20 parts by weight, particle-particle bonds cannot be obtained,
It does not come together as a pavement. On the other hand, if it exceeds 60 parts by weight, the urethane prepolymer becomes excessive with respect to the particle-urethane prepolymer system and is flowed out of the system, and the hollow portion is lost, which causes blistering. Inconvenience occurs. It is more preferable that the amount of the urethane prepolymer is about 20 to 40 parts by weight with respect to 100 parts by weight of the vulcanized rubber chip.

The elastic layer formed of such vulcanized rubber chips and urethane prepolymer has a layer thickness of 5 to 50 m.
m. When the elastic body layer is less than 5 mm, the effect of forming the elastic body layer is low, the base material under the elastic body is strongly affected, and the physical strength of the elastic body is not obtained. Even if an elastic layer having a layer thickness of more than 50 mm is formed, the effect as an elastic body is not improved, which is economically disadvantageous.

The method of applying the elastic layer is not particularly limited,
The vulcanized rubber chips and urethane prepolymer are kneaded with a mixer, etc., and the mixture is leveled so that asphalt is applied on the work surface, and then flattened on the floor slab with a flattening machine etc. Lay in

In the elastic pavement of the present invention, after such an elastic layer is laid, a urethane resin layer having a height of 1 to 3 mm is formed from the liquid urethane resin having thixotropic property on the upper layer. . As the liquid urethane resin, similarly to the above-mentioned urethane prepolymer, any of various known ones composed of a polyol and an isocyanate compound can be used, but preferably polypropylene glycol or polyethylene glycol, and tolylene diisocyanate or diphenylmethane. A liquid urethane resin or the like obtained from diisocyanate is preferably used.

The liquid urethane resin used in the elastic pavement of the present invention has thixotropy, and can be usually obtained by adding a thixotropic agent to the liquid urethane resin as described above. The thixotropic agent is not particularly limited, and any powder having the property of being rapidly dispersed when added to a liquid and changing the flow characteristics of the fluid to thixotropic, so-called thixotropic agent, can be used. Suitable examples include colloidal silica, talc powder, calcium carbonate and the like.

The thixotropy index of the liquid urethane resin is not particularly limited, but is preferably 1.2 to.
It is about 4.5. By setting the thixotropy index within the above range, preferable results can be obtained in terms of workability on the rubber chip elastic pavement surface. In particular, by setting the thixotropy index to 1.2 to 3.5, more preferable results are obtained in terms of workability during construction, unevenness of the urethane layer surface, and the like.

The viscosity of the liquid urethane resin is not particularly limited, but is preferably about 5000 to 50,000 cps. By setting the viscosity of the liquid urethane resin within the above range, favorable results are obtained in terms of workability on the rubber chip layer, unevenness of the urethane surface, and the like. Especially the viscosity of 30000-45000
By using cps, more preferable results can be obtained in terms of unevenness of the urethane surface.

In the elastic pavement of the present invention, after the above-mentioned elastic layer is laid, a urethane resin layer having a height of 1 to 3 mm is formed from the liquid urethane resin having such thixotropic properties. The method for forming such a urethane resin layer is not particularly limited, but unevenness can be easily and satisfactorily formed, and since the liquid urethane resin does not have rubber chips or the like, the nozzle will not be clogged. In this respect, it is usually formed by spray coating.

The height of the irregularities is 1 to 3 mm. If the height of the unevenness is less than 1 mm, there is not much meaning to form the unevenness,
Further, even if an unevenness of more than 3 mm is formed, the material is sagged, and therefore it is disadvantageous in terms of workability and the like to form the unevenness of more than 3 mm.

The thickness of the urethane resin layer is not particularly limited, but is usually about 2 to 4 mm (the thickness of the recess).

[0022]

EXAMPLES The present invention will be described in more detail with reference to specific examples of the present invention.

Obtained from used rubber tires for passenger cars,
100 kg of vulcanized rubber chips mainly composed of styrene-butadiene copolymer rubber (SBR) and having a particle size of 6 to 12 mesh, and diphenylmethane diisocyanate (MDI), polyethylene glycol and polypropylene glycol are used so that isocyanate group / hydroxyl group = 2/1. 32 kg of the mixed urethane prepolymer was mixed to obtain a pavement material. This pavement material was laid on an asphalt floor slab with a thickness of 9 mm and left for 4 days to be hardened so as not to be broken even when a person rides on it, to obtain an elastic layer.

On this elastic layer, a liquid urethane resin (
PTMG (polytetramethylene glycol) MDI prepolymer and P. P. G. (Polyethylene glycol)
Mixture with 80 kg of talc powder is mixed with 80 kg of liquid urethane resin having a thixotropy adjusted to a viscosity of 30,000 to 40,000 cps (B type viscometer), and a height of 1 to 3 m.
Urethane resin layer with m irregularities (concave thickness 4 mm)
Was formed. The liquid polyurethane was applied by spraying with a snake pump at a pressure of 4 to 6 kgf / cm ² . The elastic pavement obtained in this way is water impermeable and does not slip even with some rainfall,
It had a comfortable feeling.

[0025]

As described in detail above, since the elastic pavement of the present invention has a simple structure of two layers, it can be constructed in a short period of time and is simple and inexpensive. In addition, since the urethane resin layer having unevenness is formed by spraying a liquid urethane resin having thixotropy and the like without forming unevenness using a rubber chip or the like, rounded unevenness with less concern about injury etc. can be easily made. It can be formed, and does not cause clogging of the spray gun for applying the urethane resin. Therefore, the elastic pavement of the present invention, the athletic field,
It can be widely used as a multi-purpose playground, tennis court, etc.

Claims (1)

[Claims] 1. A vulcanized rubber chip 1 having a particle size of 3 to 20 mesh.
20 to 60 parts by weight of a urethane prepolymer obtained by mixing an isocyanate compound and a polyol compound in an amount of 100 parts by weight so that the ratio of an isocyanate group and a hydroxyl group is isocyanate group / hydroxyl group = 2 to 3.5 is mixed. The thickness of the elastic layer is 5 to 50 mm, and the thickness is 1 to 3 by the thixotropic liquid urethane resin.
An elastic pavement formed by forming a urethane resin layer having irregularities of mm.