JP2007169390A - Elastic pavement material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic pavement material maintaining high wet skid resistance not only in the early stage of use but also after worn. <P>SOLUTION: The elastic pavement material comprises a rubber chip and/or a rubber powder, an aggregate, and a resin binder, wherein the resin binder comprises anatase titanium oxide. The anatase titanium oxide is preferably added to the resin binder in an amount within the range of 0.1-10 mass%. A urethane binder is preferred as the resin binder. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elastic pavement material, and more particularly to an elastic pavement material for improving slip resistance (wet μ) when wet.

  Conventionally, a low noise elastic pavement using a curable resin such as urethane or epoxy as a binder is known as a method of using vulcanized rubber in the form of powder or chips. In addition, an elastic pavement in which rubber chips are mixed with a binder and press-molded is used on sidewalks, playgrounds, roadways, and the like.

  These elastic pavements using rubber chips have excellent effects such as shock absorption during walking and safety during falls due to the elasticity of the rubber chips, and since there are voids inside, in addition to drainage and breathability Therefore, it is also attracting attention as a functional elastic pavement material for reducing traffic noise in urban areas because it is effective in reducing noise generated on tires and road surfaces.

Regarding such an elastic pavement material, for example, in Patent Document 1, as a technique for promoting material recycling, a crushed material of a thermosetting resin molded product and a rubber chip are mixed at a predetermined mixing ratio, and a urethane resin is used as a binder. Pavement materials formed into blocks or plates have been proposed. In Patent Document 2, a lightweight waste such as rubber or plastic is crushed to an appropriate size as an aggregate, and a composition obtained by mixing the aggregate and a binder such as urethane resin is cured. A pavement block is disclosed.
JP 2002-322602 A (Claims etc.) JP 2000-34702 A (Claims etc.)

  However, it has been known that if elastic pavement has been used for many years, rubber will come out on the surface of the elastic pavement, and slip resistance in wet conditions such as in the rain (hereinafter simply referred to as “wet μ”) will be extremely reduced. ing. In order to solve this problem, by mixing fine silica sand or stone powder in the elastic pavement, although the initial wet μ increases, the silica sand gradually falls off the binder, while the rubber does not fall off and remains. For this reason, the elastic pavement surface is mostly made of rubber, and when it gets wet, it becomes a water film.

  Among the curable resins, the elastic pavement using a urethane resin as a binder has a problem that the slip resistance (wet μ) in a wet state such as rainy weather is low. On the other hand, in the paving material described in Patent Document 1, excellent slip resistance is obtained by mixing a thermosetting resin molded product and a rubber chip with a urethane resin binder. Is considering only the slip resistance in an unused state, and it has been desired to realize a pavement that can obtain a good wet slip resistance even after wear due to use.

  Accordingly, an object of the present invention is to provide an elastic pavement material that can satisfactorily ensure slip resistance in a wet state not only in the initial stage of use but also after wear, by solving the above problems.

As a result of intensive studies to solve the above-mentioned problems, the present inventor added anatase-type titanium oxide (TiO ₂ ) to the binder in the elastic pavement material, and forcedly deteriorates the binder with sunlight. Was appropriately removed from the elastic pavement and found that a surface in which the initial wet μ was always maintained was formed over a long period of time, and the present invention was completed.

  That is, the present invention is an elastic pavement material containing a rubber chip and / or rubber powder, an aggregate, and a resin binder, wherein the resin binder contains anatase type titanium oxide.

  In the elastic pavement material of this invention, it is preferable that the anatase type titanium oxide is contained in the said resin binder within the range of 0.1-10 mass%. A urethane binder can be suitably used as the resin binder. Furthermore, quartz sand can be suitably used as the aggregate.

  ADVANTAGE OF THE INVENTION According to this invention, the elastic pavement material which can ensure the slip resistance in a wet state favorably not only at the initial stage of use but also after wear can be provided.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The elastic pavement material of the present invention is an elastic pavement material containing a rubber chip and / or rubber powder, an aggregate, and a resin binder, and it is important that the resin binder contains anatase-type titanium oxide. Due to the photocatalytic action of such anatase titanium oxide, the binder is gradually deteriorated by sunlight, thereby forcibly removing the rubber from the elastic pavement, and a new surface where the initial wet μ is always maintained over a long period of time. Can be formed.

  It is known that anatase-type titanium oxide has a photocatalytic action. From the viewpoint of productivity and photocatalytic performance, fine particles having an average particle diameter (median diameter) of 10 to 200 nm can be suitably used. Moreover, the addition amount with respect to the resin binder of anatase type titanium oxide becomes like this in the range of 0.1-10 mass% preferably. That is, since anatase type titanium oxide has a very strong photocatalytic effect, if it is added in a large amount, it immediately deteriorates the resin binder and leads to early destruction of the elastic pavement. On the other hand, when the amount is too small, a sufficient deterioration effect of the resin binder does not appear, and therefore, it is preferably 1% by mass or more.

  As an aggregate that can be used in the present invention, a conventional natural aggregate or the like can be used, and is not particularly limited. Specific examples include natural aggregates such as river gravel and river sand, and recycled aggregates such as crushed stone, quartz sand, slag, concrete, and glass. Moreover, it is preferable to mix 5 volume% or more of fine aggregates with a particle size of 0.5 mm or less with respect to the coarse aggregate with a particle size of 0.5-30 mm normally. The coarse aggregate mainly forms a porous structure in order to obtain water permeability, and a hard aggregate having a sharp shape like a crushed stone that meshes with each other to form a gap is suitable. On the other hand, the fine-grained aggregate adheres to the surface of the large-sized coarse-grained aggregate and brings about an anti-slip action (polishing effect like sandpaper) on the tire or the like.

  The amount of aggregate in the elastic pavement material of the present invention is preferably 50 to 5% by volume. If the proportion of the aggregate in the elastic pavement material is less than 5% by volume, the strength is not sufficient, while if it exceeds 50% by volume, sufficient elasticity and bass effect cannot be obtained.

  The rubber chip and / or rubber powder is blended in the elastic pavement material in order to impart elasticity to the pavement surface, and the material is not particularly limited, and natural rubber, isoprene rubber, styrene-butadiene is not limited. Rubber, butyl rubber, ethylene-propylene rubber or the like can be used. Such rubber chips and / or rubber powders can also be obtained from waste materials of used vulcanized rubber products such as rubber tires, weather strips, hoses, etc., unnecessary end materials generated during molding, molding defects, and the like. In addition, the particle size of the rubber chip and / or rubber powder can be suitably used from a fine one of 1 mm or less to about 10 mm, especially those having a particle size of about 1 to 5 mm. This is more preferable because it is effective in forming voids.

  The proportion of rubber chips and / or rubber powder in the elastic pavement material of the present invention is preferably 30 to 60% by volume. If this proportion is less than 30% by weight, the effect as an elastic paving material is not sufficient, while if it exceeds 60% by weight, sufficient physical properties for application to pavement cannot be obtained.

  As resin binders that are bonded to aggregates and rubber chips to form pavement materials and receive photocatalytic action by anatase-type titanium oxide, thermosetting resin binders such as urethane binders and epoxy binders commonly used today are used. Can be mentioned.

  The urethane binder is, in particular, a two-component urethane binder, preferably a mixture of an isocyanate group terminal prepolymer and a polyol in a hydroxyl group / isocyanate group equivalent ratio of, for example, 0.2 to 0.8. The one-component urethane binder is very difficult to adjust the curing time compared to the two-component urethane binder, is not versatile, and has a difficulty in shortening the curing time.

  In addition, as an example of the isocyanate terminal group prepolymer of a two-component urethane binder, the isocyanate content is 5 to 25%, the viscosity is 1000 to 5000 cP (25 ° C.), and the average number of functional groups of the isocyanate terminal group prepolymer is 2 to 3. Things. Examples of the isocyanate for the prepolymer include diphenylmethane diisocyanate polyisocyanate. As the active hydrogen compound used for modification, polyalkylene glycol having a molecular weight of about 1000 to 3000 is usually used.

  On the other hand, as an example of the polyol, it is preferable that the average number of functional groups is 2 to 6, the average molecular weight is 1000 or less, and more than half of the hydroxyl groups are primary hydroxyl groups from the viewpoint of reactivity. Examples include glycol, diethylene glycol, and polyalkylene ether glycol.

  As a compounding quantity of this urethane binder, 20-35 volume% is preferable from a viewpoint of the binding strength of an aggregate.

  In addition, in the elastic pavement material of the present invention, the organic silane is added in an amount of 0.1 to 10% by volume with respect to the urethane binder, thereby increasing the bonding strength between the urethane binder and the aggregate, thereby improving the strength and durability. Improvements can be made. As such an organic silane, an epoxy silane, mercapto silane or the like can be used.

  Furthermore, the elastic pavement material of the present invention may contain a urethane binder curing accelerator and other additives such as an antioxidant and an ultraviolet absorber.

  The elastic pavement material of the present invention uses a resin binder, in particular, a urethane binder to which a silane coupling agent has been added and mixed in advance as necessary, and an aggregate, rubber chip and / or rubber powder, and necessary. The additive added according to the above can be obtained by mixing appropriately. The mixing method in this case is not particularly limited, and any method that can uniformly mix these may be used. The temperature at the time of addition and mixing of the resin binder to the aggregate may be normal temperature, but curing is delayed at a low temperature, and curing is promoted at a high temperature. Therefore, it is preferable to adjust the temperature as necessary.

  Such an elastic pavement material is usually applied to a thickness of about 10 to 50 mm so that voids with a porosity of about 10 to 40% are formed and cured.

  The elastic pavement material of the present invention is a material (primary construction type) in which a pavement surface is formed by laying directly after applying a primer treatment to a road surface to be constructed as necessary. A block-shaped molded product (press-molded product) molded and cured in a predetermined shape with a mold may be laid on the construction surface, and is not particularly limited.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
As shown in Table 1 below, anatase-type titanium oxide (TiO ₂ ) (trade name: ST-01) manufactured in advance in a urethane binder (RB-08 manufactured by Nippon Polyurethane Co., Ltd.) is 0.5. In the mixer, the ratio of the urethane binder / mixed silica sand (No. 5-8, average particle size to 0.2 mm) / rubber powder (average particle size 3 mm) is 25:20:55 (volume ratio). And stirred at room temperature for 5 minutes. Thereafter, this was filled in a mold and cured for 2 to 3 days to prepare a rectangular parallelepiped test body having dimensions of 50 × 50 × 2.5 cm.

  About the obtained test body, the slip resistance test in the wet state at the time of 60 km / h driving | running | working was done with the dynamic friction tester (DFT). In addition, in order to measure the wet μ after wear, the rotation test machine (Nakajima technical sales load 50kg, tire: for small trucks, table rotation speed: 17rpm (free), tire rotation speed: 10rpm) 2000 rotations After the surface of the specimen was worn, the specimen was irradiated with ultraviolet rays so that the amount of ultraviolet rays would be half a year, and the sliding resistance was measured again under the same conditions by DFT. The obtained results are shown in Table 1 below.

Comparative Example A test specimen was prepared in the same manner as in Example 1 except that the anatase-type titanium oxide was not added to the urethane binder, and the obtained test specimen was subjected to the same wear test as in Example 1. . The obtained results are shown in Table 1 below.

Examples 2-5
Test specimens were prepared in the same manner as in Example 1 except that the addition amount of anatase-type titanium oxide in the urethane binder was changed as shown in Table 1 below. The same wear test was carried out. The obtained results are shown in Table 1 below.

  In Comparative Example 1, the initial wet μ was 0.38, and the wet μ after the slip test / light degradation was 0.28, which was clearly reduced. In contrast, when 0.5%, 1, 2, 5 and 10% by mass of anatase-type titanium oxide was added to the urethane binder as in Examples 1 to 5, the sliding test / light was compared with the comparative example. It can be seen that the wet μ after the deterioration is improved. This is presumably because a small amount of rubber was removed from the surface due to photodegradation of the binder, and a new surface appeared. Even when 10% by mass of anatase-type titanium oxide was added to the urethane binder, the wet μ after the transition test / photodegradation did not change from that when 5% by mass was added. On the other hand, when adding 10% by mass, a very large amount of rubber is removed. If too much is added, the rubber in the elastic pavement will fall off very quickly due to light degradation, leading to early destruction of the elastic pavement. Seem.

Claims (4)

  An elastic paving material containing a rubber chip and / or rubber powder, an aggregate, and a resin binder, wherein the resin binder contains anatase-type titanium oxide.   The elastic pavement material according to claim 1, wherein the resin binder contains anatase-type titanium oxide within a range of 0.1 to 10% by mass.   The elastic pavement material according to claim 1 or 2, wherein the resin binder is a urethane binder.   The elastic pavement material according to any one of claims 1 to 3, wherein the aggregate is silica sand.