JPH04131404A - Elastic pavement block - Google Patents

Abstract

PURPOSE:To provide an elastic pavement block which has small dimensional change and deformation stress due to heat, is deformed less by repeated use, and has high permeability by forming a fiber-shaped gum chip material by a binder so that the percentage of void is a specified percentage. CONSTITUTION:Fiber-shaped gum chips are weighed and put into a mixer for mixing. Separately, urethane prepolymer and pigment-containing reactive liquid rubber are weighed and mixed. Then, the two materials are put into a mixer and mixed for about 3 minutes. This mixture is poured into a mold 2 which has been heated to about 130 deg.C in advance, and pressed lightly and cured at about 130 deg.C for 10 minutes to form an elastic pavement block with a percentage of void of 30-40%. This process provides a high-performance elastic pavement block which has high tensile strength, durability, elasticity and permeability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an elastic paving block, and particularly to an elastic paving block that exhibits small thermal dimensional changes and has excellent water permeability, elasticity, and durability.

[Prior Art] Conventionally, resin-based paving materials for indoor and outdoor floors and road surfaces include those of an on-site construction type and those of a pre-formed block type.

For on-site construction type, ■ Difficult to do anything other than single color pavement.

■ There are large variations in quality depending on the weather and the builder.

■ Poor construction efficiency.

■ Indoor construction is difficult due to odors, dirt, and the need to transport construction machinery.

Because of these drawbacks, block-type paving materials that do not have these problems are attracting attention.

Conventional block-type paving materials are made by molding rubber chips with a binder, and have a porosity of about 10%. In other words, the smaller the porosity, the better the physical properties of the block, the better its shape retention, the firmer it feels, the easier it is to manufacture, the lower the product defect rate, and the higher the yield. has a relatively small porosity.

Although there are fibrous rubber chips and granular rubber chips as rubber chip materials, granular rubber chips are generally used because they are easy to handle. The granular rubber chips are obtained by pulverizing vulcanized rubber such as waste tires using a pulverizer, and are usually in the form of granules or powder with an angle of repose of 5 mm.

[Problems to be Solved by the Invention] However, in a paving material with a porosity of 10% or less, the thermal dimensional change is large and the deformation stress is large, so blocks may peel off from the construction base and stick up. It also has the disadvantages of low water permeability and elasticity, and large deformation with repeated use, resulting in poor durability.

The present invention solves the above-mentioned conventional problems, has small thermal dimensional changes, small deformation stress, and small deformation due to repeated use.
The purpose is to provide elastic paving blocks with excellent water permeability, elasticity, and durability.

[Means for Solving the Problems] The elastic paving block of the present invention is formed by molding fibrous rubber chip material with a binder, and has a porosity of 30 to 40%.
It is characterized by

The present invention will be explained in detail below.

The fibrous rubber chip material used in the present invention is generally obtained by cutting the tire tread part with a special device during the manufacture of recycled tires, and has a thickness of about 1 to 2 mm.
A length of about 4 to 15 mm is suitable.

The binder is preferably one obtained by blending a reactive liquid rubber with a polyurethane prepolymer having a terminal NCO group as a liquid resin. Examples of the reactive liquid rubber constituting such a binder include commercially available diene liquid rubbers such as butadiene, chlorobrene, isoprene, 1,3-betadiene, and cyclopentadiene.
Those having an H group are preferred. That is, a liquid rubber having a terminal OH group has a low viscosity and is easy to handle, and is extremely advantageous because it reacts with the NCO group of the polyurethane prepolymer to form stable urethane bonds and is cured. Note that as reactive liquid rubbers, there are also liquid rubbers with terminal C0OH groups, but those with C0OH groups are NG.
It is not preferable because it reacts with O groups and produces gases such as CO2, which may impair the physical properties of the product due to foaming or the like.

Specifically, the reactive liquid rubber suitable for the present invention includes the following liquid polybutadiene rubber (manufactured by Idemitsu Petrochemical Co., Ltd.).
can be mentioned.

On the other hand, polyurethane prepolymers having terminal NCO groups include MDI (methylene diisocyanate) and/or
Or a prepolymer obtained by reacting an isocyanate component such as TDI (toluidine diisocyanate) with one or more polyol components such as polyether polyol, polybutadiene polyol, or the above-mentioned liquid polybutadiene or liquid polypropylene. Free N
CO residue is 5.0-15.0% by weight, viscosity is 3000-3000%
7000c ps / 20℃, especially 1500c
It is preferable that the temperature is about ps/20°C.

In the present invention, the proportion of the reactive liquid rubber to the polyurethane prepolymer constituting the binder is preferably 8 to 15% by weight. If this proportion is less than 8% by weight, the following advantages (1) and (2) cannot be obtained. Also,
If it exceeds 15% by weight, weather resistance and strength will be poor.

The binder obtained by blending such a polyurethane prepolymer with a reactive liquid rubber, especially a reactive liquid rubber having a terminal OH group, has excellent adhesion and flexibility with rubber chips without impairing the properties of polyurethane. A block with excellent physical properties can be obtained.

■ Mold contamination due to poor adhesion to the mold, which is a disadvantage of polyurethane, is prevented, and mold releasability and productivity are improved.

These effects are extremely advantageous. That is, fibrous rubber chips are usually used for tire tread cutting (NR/5B
R) However, reactive liquid rubbers such as terminal OH group liquid polybutadiene and liquid polyisoprene have good compatibility with such cutting pieces and can provide good adhesion. Furthermore, since the polarity is low, mold releasability is improved.

In addition, when a liquid rubber having a terminal NGO group is used as the binder, although the mold releasability is improved, the disadvantages of the rubber (poor weather resistance, poor physical properties) are undesirable.

In the present invention, a pigment may be added to the binder to improve weather resistance.

In this case, it is preferable from the viewpoint of physical properties and productivity to use the pigment by dispersing it in a reactive liquid rubber. As the pigment, powdered inorganic pigments such as zinc white, zinc yellow, iron oxide, and rutile-type titanium oxide are used from the viewpoint of weather resistance, hiding power, and the like. These inorganic pigments are usually used together with dioctyl phthalate (DOP), polyols, etc.
Since OP adversely affects the physical properties of the product and polyols cannot improve mold release properties, their use is not preferred in the present invention. The amount of the powdered inorganic pigment blended is preferably 30 to 70% by weight based on the reactive liquid rubber.

To manufacture the elastic paving block of the present invention, fibrous rubber chips and a binder are mixed, put into a mold of a desired shape, and hardened and molded to a desired porosity. In this case, the porosity can be adjusted by adjusting the amount of mixed raw materials charged into the mold. In addition,
The blending ratio of fibrous rubber chips and binder is
It is preferable to use 10 to 20 parts by weight of the binder per 100 parts by weight of the fibrous rubber chips.

[Function] By molding fibrous rubber chips with a binder, an elastic paving block with higher mechanical strength than one using granular rubber chips can be obtained.

Moreover, elastic paving blocks with a porosity of 30 to 40%,
Fully satisfactory values can be obtained in all properties such as thermal dimensional change rate, amount of deformation due to repeated treading, tensile strength, elasticity, water permeability, durability, etc. Note that the block of the present invention has continuous voids and has excellent water permeability.

[Example] EXAMPLES The present invention will be explained in more detail with reference to Examples below.

Example 1.2 An elastic paving block with a porosity of 35% was manufactured using raw materials having the composition shown in Table 1.

That is, first, fibrous rubber chips were weighed, put into a mixer, and stirred. Separately, the urethane prepolymer and the pigment-containing reactive liquid rubber were weighed and mixed by stirring, and then put into the mixer and stirred for about 3 minutes. As shown in Figure 1,
The obtained mixture 1 (specific gravity 1.16) was poured into a mold 2 preheated to 130°C (750 g (64 g) of the raw material mixture per 1000 cc of mold volume (product volume)
7CC) used), as shown in Figure 2, 13 in brace 3
It was hardened under light pressure at 0° C. for 10 minutes to obtain an elastic paving block with a porosity of 35%. The curing reaction at this time was mostly carried out by the moisture contained in the fibrous rubber chips and the moisture in the air. Note that the porosity is determined by the following formula.

The tensile strength (kg/am') and elongation (%) of the obtained elastic paving block were measured, and the results were
Shown in the table.

Table 1 *1 Fiber-like rubber chip: Average thickness = 1 to 2 mm Average length = 4 to 10 mm Specific gravity = 1.16 *2 Polyurethane prepolymer: Takenate F-172AJ manufactured by Takeda Pharmaceutical Co., Ltd. Specific gravity = 1. 09 *3 Pigment-containing reactive liquid rubber iron oxide, chrome yellow: Poly bd R-1
5HT specific gravity = 1.38 Example 3. Comparative Example 1 In Example 1, blocks with different porosity were manufactured by increasing or decreasing the amount of the raw material mixture poured into the mold, and the tensile strength, hydraulic permeability coefficient, and thermal dimensional change rate (from 0°C to 50°C) with respect to the porosity were measured. and the amount of deformation (deformation after 150,000 spike tests), and the results are shown as No. 1 and No. 1 in Figure 3, respectively.
．． It is shown in FIGS. 4 to 6.

As is clear from Figures 3 to 6, the porosity is 30 to 40.
% of the elastic paving block of the present invention has the best balance of properties among tensile strength, hydraulic permeability, thermal dimensional change rate, and amount of deformation.

On the other hand, when the porosity is less than 30%, the tensile strength is high, but the water permeability is insufficient, and the thermal dimensional change rate and deformation are large; on the other hand, when the porosity exceeds 40%, Although it has high water permeability and small thermal dimensional change rate and small amount of deformation, it has low tensile strength and is not practical in either case. (Those with a porosity of less than 30% and more than 40% are comparative examples.) Comparative Example 2 In Example 3, instead of the fibrous rubber chips,
Blocks with different porosity were manufactured in the same manner except that granular rubber chips were used, and the relationship between porosity and tensile strength was investigated, and the results are shown in Figure 3 No. 2.

From FIG. 3, it is clear that a block with higher strength can be obtained when using fibrous rubber chips than when using granular rubber chips.

[Effects of the Invention] As detailed above, according to the elastic paving block of the present invention, (1) The rate of thermal dimensional change is small, and there is no fear that the block will stick up from the construction surface due to thermal expansion.

■ Less deformation even when repeatedly stepped on by spiked shoes such as golf shoes ■ High tensile strength and excellent durability. That is, as long as the tensile strength is fOkg/cm'' or more, there is no problem with the durability as an elastic paving block, but according to the present invention, such strength can be sufficiently ensured.

■ Excellent elasticity and water permeability.

Provided is a high-performance elastic paving block that combines excellent performance such as:

[Brief explanation of drawings]

1 and 2 are cross-sectional views explaining the block manufacturing method in the example, and FIGS. 3, 4, 5, and 6 are graphs showing the results of the example. 1... Raw material mixture, 2... Mold, 3...
·press. Agent Patent Attorney Tsuyoshi Shigeno Figure 3 Figure 4 Figure 5 Thermal dimensional change rate (%) Figure 6

Claims (1)

[Claims] (1) An elastic paving block formed by molding fibrous rubber chip material with a binder and having a porosity of 30 to 40%.