JP2003155701A - Elastic block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elastic block comprising two layers or more capable of preventing a warp. SOLUTION: The elastic bock is characterized in that a plurality of elastic layers including soft elastic aggregates and binder connecting the soft elastic aggregates are laminated and a ratio of non-volatile matter of the binders respectively included in mutually adjacent layers is within a range of 0.95-1.05. Hard aggregates can be included in the elastic layer. Thereby, a warp can be prevented and a flexible elastic block can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic block, and more particularly to an elastic block used for a ground such as a roadway, a riverbed promenade, a golf course, a tennis court, and an athletic stadium.

[0002]

2. Description of the Related Art Conventionally, on roads, river promenades, tennis courts and athletic stadiums, it is easy to repair in order to avoid strain on the waist and knees when people walk or exercise. Therefore, an elastic block is used in which soft elastic aggregates such as rubber chips are bonded with an elastic binder such as a resin binder.

This elastic block has an upper layer mainly composed of hard aggregates such as ceramic grains in order to give its surface durability and weather resistance, and soft elasticity such as rubber chips in order to maintain cushioning properties against impact. Some of them are composed of two layers consisting of an aggregate and a lower layer as the main aggregate. However, with regard to the elastic block composed of these two layers, a warp occurs after the molding process and a flat elastic block is produced. Sometimes couldn't get.

As a technique for preventing the warpage, Japanese Patent No. 2896542 discloses an elastic block in which hard elastic aggregates and soft elastic aggregates are mixed in a predetermined ratio in an elastic upper layer portion and an elastic lower layer portion. Has been done.

However, since the elastic lower layer portion of this elastic block is always mixed with the hard aggregate at a predetermined ratio,
It was not possible to obtain a flexible elastic block having excellent cushioning properties.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and prevents the occurrence of warpage while
It is an object of the present invention to provide an elastic block composed of two or more layers that is softer than before.

[0007]

In order to achieve the above object, the present invention has a plurality of elastic layers including soft elastic aggregates and a binder connecting the soft elastic aggregates, which are adjacent to each other. The ratio of the nonvolatile content of the binder contained in each of the.
An elastic block within the range of 95 to 1.05. Here, the elastic layer may include hard aggregate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

In the elastic block of the present invention, the ratio of the nonvolatile content of the binder contained in each of the plural elastic layers adjacent to each other is in the range of 0.95 to 1.05.

As a result of repeated tests by the present inventors regarding the prevention of warpage of the elastic block, the ratio of the non-volatile components of the binder contained in each of the elastic layers adjacent to each other was 0.95 to 1. This is because it has been found that when the value is in the range of 05, it is possible to prevent warpage of the elastic block after the molding process.

By bringing the non-volatile components of the binders of the adjacent elastic layers closer to each other, the changes in the non-volatile components remaining in these elastic layers become substantially the same, and the contraction rates of these elastic layers become the same. As a result, it is considered that the warpage of the elastic block can be reduced.

The term "nonvolatile matter" as used herein means the mass% expressed by the mass of the binder after drying / the mass of the binder before drying.

Therefore, in the elastic block of the present invention, if only the non-volatile component of the binder used for producing the elastic block is adjusted to fall within the above range, the soft elastic aggregate,
Even if any of the hard aggregates is used, it is possible to prevent warpage of the elastic block after molding. Therefore, when only the soft elastic aggregate is used for the lower layer, an elastic block having two or more layers that is softer than the elastic block disclosed in Japanese Patent No. 2896542 can be manufactured.

A urethane resin binder is preferred as the binder used in the present invention. This is because the urethane resin binder has excellent elongation, strength, and good abrasion resistance.

The material of the urethane resin binder is an organic isocyanate such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (TDI), or a mixture thereof, diphenylmethane diisocyanate (MDI), liquid diphenylmethane diisocyanate, A composition of tolylene diisocyanate is preferred.

Specifically, Pandex TP-2122
(Manufactured by Dainippon Ink and Chemicals, Inc.), SBU-1-0620
(Sumitomo Bayer Urethane Co., Ltd.) and the like.

The content of isocyanate (NCO) group in the urethane resin binder is 2 to 20% by mass, preferably 5 to 15% by mass. If it is less than 2% by mass, the bonding force between the soft elastic aggregates is not sufficient, and if it exceeds 20% by mass, the binder layer easily foams, and the bonded product becomes hard and the whole becomes brittle.

The viscosity of the urethane resin binder is 15
00-8000 cps, particularly preferably 2500-50
The range of 00 cps is preferable in terms of kneading workability of the soft elastic aggregate and fluidity of the binder.

As the binder used in the present invention, in addition to the urethane resin binder, a binder prepared by blending a reactive liquid rubber with an organic isocyanate or a urethane prepolymer having a terminal NCO group can also be used. As the reactive liquid rubber, commercially available diene liquid rubbers such as butadiene, chloroprene, isoprene, 1,3-pentadiene, and cyclopentadiene having a terminal OH group can be used. Terminal O
The liquid rubber having an H group reacts with the NCO group to form a stable urethane bond and cures. Specifically, Takenate F-181P (manufactured by Takeda Pharmaceutical Co., Ltd.) and the like can be used.

The above-mentioned binder is preferably mixed in an amount of 10 to 40% by mass with respect to the soft elastic aggregate incorporated in the elastic layer. More preferably, it is 15 to 35 mass%. If the mixing amount of the binder is less than 10% by mass, the soft elastic aggregate cannot be sufficiently connected, and if the mixing amount is more than 40% by mass, the elastic block is covered with the binder film and the appearance is deteriorated.

Further, a diluent may be used to adjust the ratio of the non-volatile content of the binder contained in the elastic layers adjacent to each other within the range of 0.95 to 1.05.

The type of the diluent is not particularly limited, but an organic solvent can be mainly used. Particularly, an organic solvent in which the boiling point of the diluent is not higher than the molding temperature is preferable. More preferably, the diluent is an organic solvent having a boiling point of 170 ° C. or lower. When the boiling point of the diluent is equal to or higher than the molding temperature of the elastic block, the diluent may not be removed from the elastic block. Specifically, ethyl acetate, butyl acetate, toluene, xylene, methyl isobutyl ketone and the like can be preferably used. Since a binder containing an isocyanate group can be used as a binder, an organic solvent having a hydroxyl group that can affect the reaction system of this binder is not preferable.

The elastic block of the present invention can be produced by laminating an elastic layer obtained by mixing the above-mentioned binder and soft elastic aggregate by press molding or the like.

To the elastic layer of the present invention, it is possible to add only soft elastic aggregate, or it is possible to add not only soft elastic aggregate but also hard aggregate.

As the material of the soft elastic aggregate, rubber chips obtained by crushing vulcanized rubber such as natural rubber, styrene butadiene rubber, nitrile rubber, butyl rubber, polyurethane rubber, polybutadiene rubber, ethylene propylene rubber, etc. are used. Further, the soft elastic aggregate may be a waste material obtained by crushing a rubber product such as a tire or a belt of a belt conveyor. The particle size of these pulverized products is preferably in the range of 0.3 to 5 mm, and particularly preferably in the range of 0.5 to 2.5 mm. Further, a hijiki-shaped rubber chip generated when cutting a used tire or the like is also used. This hijiki rubber tip has a thickness of 1 to 2 mm and a length of 4 to 15 m.
It is preferably in the range of m.

Further, a hard aggregate can be mixed in the elastic layer to the extent that the flexibility of the elastic block of the present invention is not impaired.

As the material of the hard aggregate, natural stone, wood chips,
Bamboo pieces, shells, ceramic particles, hard plastic particles, or hard plastic crushed products are used. The particle size of this hard aggregate is preferably in the range of 0.3 to 5 mm, and particularly preferably in the range of 0.5 to 2.5 mm. If the particles having a particle size of less than 0.3 mm are used, the porosity cannot be sufficiently secured and the water permeability becomes insufficient, and if it exceeds 5 mm, the strength becomes small.

The hard aggregate is preferably mixed in an amount of 5 to 50 parts by mass with respect to 100 parts by mass of the soft elastic aggregate contained in the elastic layer. If the amount of the hard aggregate is less than 5 parts by mass, it will be slippery when wet, and if it is more than 50 parts by mass, the cushioning property of the elastic block will be deteriorated.

Further, elastic layers having different bending rigidity can be laminated.

[0030]

EXAMPLES The present invention will be described in more detail below with reference to examples. Table 1 shows the configurations of the elastic blocks of Examples 1 to 5 and the degree of occurrence of warpage. Also, Table 2
Shows the structure of the elastic blocks of Comparative Examples 1 to 3 and the degree of warpage. Further, in this example, only the soft elastic aggregate and the binder were used, but the same result is shown even when other substances are contained in the elastic layer.

Here, the porosity is the porosity (%) = [1-
(Volume of raw material mixture consisting of soft elastic aggregate and binder /
Mold volume)] x100. The nonvolatile content (%) is represented by (mass of binder after drying / mass of binder before drying) × 100, and is measured according to JIS-K6833.

(1) Preparation of Elastic Block The basic composition of the upper layer and the lower layer was prepared based on Tables 1 and 2.

Fiber rubber 612 (manufactured by Misawa Toyo Co., Ltd.) was used as the soft elastic aggregate in the elastic blocks of Examples 1 to 5 shown in Table 1 or the elastic blocks of Comparative Examples 1 to 3 shown in Table 2. Here, the nonvolatile content of the binder C is 90%
And the nonvolatile content of binders A and B is 100%. Further, the lower layers of Examples 3 to 5 shown in Table 1 and Table 2
In the binder B contained in the lower layer of Comparative Examples 2 to 3 shown in FIG. 3, 90% (Example 3), 94.7% (Example 4), and 85.7% of non-volatile components using ethyl acetate as a diluent, respectively. (Example 5), 95% (Comparative Example 2) and 85% (Comparative Example 3)
Adjusted to. The soft elastic aggregate amount and the binder amount shown in Table 1 or Table 2 are represented by mass% based on the total mass of the substances contained in the upper layer or the lower layer.

First, the fiber rubbers 612 used for the upper layer and the lower layer are weighed and put into separate mixers and stirred. Next, the binder used in the upper layer and the lower layer is weighed and charged into a mixer in which the fiber rubbers 612 used in the upper layer and the lower layer are charged, respectively,
Stir for 5 minutes. The obtained raw material mixture of the upper layer and the lower layer is poured into a mold preheated to 160 ° C. so as to have a two-layer structure, and pressed at 160 ° C. for 20 minutes.
The elastic blocks of Examples 1 to 5 and Comparative Examples 1 to 3 were obtained by pressure curing for minutes. The size of the obtained elastic block is 500 mm × 500 mm × 30 mm.

This time, pressing was performed so that the upper layer having a thickness of 10 mm was the lower side and the lower layer having a thickness of 20 mm was the upper side.
The results were the same even when pressing was performed with the upper layer on the upper side and the lower layer on the lower side.

(2) Evaluation of degree of warp occurrence Regarding the degree of warp occurrence of the obtained elastic blocks, first, each elastic block is placed on a smooth iron plate, and then each elastic block is placed. Evaluation was made as follows by pressing the four corners and the center of the block. The results are shown in the bottom row of Table 1 or Table 2. ◯: No gap was formed between the elastic block and the iron plate. X: A gap was generated between the elastic block and the iron plate.

[0037]

[Table 1]

[0038]

[Table 2]

(3) Evaluation Results The ratio of the nonvolatile content of the binder contained in the upper layer of the elastic blocks of Examples 1 to 5 and the nonvolatile content of the binder contained in the lower layer is
Since it is included in the range of 0.95 to 1.05,
The elastic blocks of ~ 5 were able to prevent warpage.

On the other hand, the ratios of the non-volatile content of the binder contained in the upper layer of Comparative Examples 1 to 3 and the non-volatile content of the binder contained in the lower layer were 0.90 (Comparative Example 1) and 0.947 (Comparative Example, respectively). 2), 1.059 (Comparative Example 3), 0.95 to 1.
Since it was not included in the range of 05, the elastic blocks of Comparative Examples 1 to 3 could not prevent warpage.

[0041]

Industrial Applicability The present invention can provide an elastic block composed of two or more layers which is softer than before while preventing the occurrence of warpage.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) E01C 13/00 E01C 13/00 AF term (reference) 2D051 AA07 AB03 AB04 AB05 AF01 AF07 AG03 AG13 AH02 AH03 DA02 DB02 DC09 4J002 AA00Y AC01X AC03X AC07X AC08X AC13X AH00Y BB15X BB18X CK02W CK02X DJ006 DM006 FD01X FD01Y FD016 GF00 GL00

Claims (2)

[Claims] 1. A plurality of elastic layers including a soft elastic aggregate and a binder connecting the soft elastic aggregates are laminated, and a nonvolatile content ratio of the binder contained in each of adjacent layers. Is in the range of 0.95 to 1.05. 2. The elastic block according to claim 1, wherein the elastic layer contains hard aggregate.