JPH0248682B2 - TENISUKOOTOYODANSEIHOSOZAINOSEKOHO - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method for constructing an elastic paving material for tennis courts;
More specifically, the present invention relates to a method for forming an elastic paving material for tennis courts in which the adhesion between laminated layers and the coefficient of repulsion and friction of tennis balls are less likely to change over time.

In general, all-weather chemical play coats are created by pasting vulcanized rubber moldings or from a composition of various synthetic resins mixed with rubber powder, No. 6 to 8 silica sand, pigments, etc., and are used as play coats after rain. It is possible to replay the surface without completely drying it, and maintenance is easy and does not require much effort.
Widely spread and popular. In particular, tennis play courts have an elastic layer made of synthetic resin emulsion (or latex) and rubber powder, and a colored surface layer containing No. 6 to 8 silica sand and pigments on top of the elastic layer.
Recently, it has been widely adopted because it is easy to manage and take effort, requires short work time, and has low material and construction costs. However, due to the difference in the water permeability of each laminated material due to the difference in material composition, the difference in the water permeability of each laminated material inhibits the adhesion of the laminated interface. The coating layer may swell or peel, which requires a long period of time for construction, and may also cause blistering and peeling over time. Furthermore, the friction coefficient and repulsion coefficient of the tennis ball may change due to wear of the color surface layer containing No. 6 to No. 8 silica sand due to play over time, and changes may occur due to local differences in the frequency of use of the tennis court. Similarly, tennis balls have different coefficients of friction and repulsion, and players have complained that the ball slips or is irregular during play, so improvements are desired.

For this reason, various methods of applying this type of chemically coated elastic paving material have been studied and some of them have been put into practical use, but no fully satisfactory results have been achieved. For example, JP-A No. 51-93519 describes ``a method of applying a resin emulsion with a composition containing rubber powder with a single or continuous particle size of 2.5 to 0 mm and a pigment.'' In this case, the rubber powder Since the rubber is colored, black rubber powder, which is crushed rubber from waste tires, cannot be used and is not economical.
Also, "Pavement, Vol. 9, No. 9" (1974, pp. 36-40)
describes a ``color paving material made of acrylic resin emulsion mixed with No. 7 silica sand.'' However, the surface is rough, so the frictional resistance is large, and the coefficient of friction may change over time, resulting in a change in the coated surface. This poses a problem when playing, as differences in the coefficient of friction can be seen depending on the location. Furthermore, JP-A-53-74723 states, ``After constructing the lower layer surface by pouring a material containing latex and rubber powder onto the base, a surface layer material consisting of an acrylic ester copolymer emulsion, an inorganic filler, and a coloring agent is applied. "Elastic pavement method for surface layer construction" is described, but there are problems such as insufficient adhesion between the layers and blistering after rain.

Therefore, the present inventors shortened the construction period by improving the water permeability balance of each laminated material in the conventional elastic paving material for all-weather chemical tennis courts made of synthetic resin emulsion (or latex), rubber powder, silica sand, pigment, etc. As a result of intensive research in order to provide a construction method that satisfies the problem of reducing blistering and peeling caused by rain and stabilizing the surface characteristics of tennis courts over time, we developed latex with a specific glass transition temperature for each layer. The present inventors have discovered that an elastic pavement material with desired properties can be obtained by using a specific combination of aggregates, leading to the completion of the present invention.

That is, the present invention provides an asphalt concrete base with a glass transition temperature (hereinafter abbreviated as Tg) of -15 to -.
Styrene-butadiene copolymer latex (hereinafter abbreviated as SBR) at 5°C and particle size 50-300μ
A composition consisting of silica aggregate of Diameter 50~
A composition consisting of 300μ silica aggregate is applied to form an elastic layer, and finally, a composition consisting of an acrylic resin emulsion with a Tg of -10 to +10℃, silica aggregate with a particle size of 100μ or less, and pigment is applied on the elastic layer. The present invention provides a method for constructing an elastic paving material for tennis courts, which is characterized by forming a colored surface layer by applying a material.

The construction method of the present invention will be explained in detail below.

In the present invention, the SBR used in the undercoat layer and the elastic layer may have a Tg of -15 to -5°C, and usually have a styrene content of 40 mol% or less. In particular, from the viewpoint of adhesion to the substrate and adhesion to rubber powder, silica aggregate, etc., monomers containing carboxyl groups (for example, acrylic acid, methacrylic acid, or crotonic acid) are copolymerized in several mol% (hereinafter referred to as carboxyl group-containing monomers). (referred to as SBR) is preferred. If this Tg exceeds -5℃, adhesiveness will be insufficient,
Also, below -15°C, the adhesive strength is strong and poses a problem in construction work.

In the present invention, the silica aggregate used in the undercoat layer and the elastic layer includes those classified into particle sizes in the range of 50 to 300 microns, such as No. 6, No. 7, and No. 8 silica sand. Particularly, using the particle size in this range is advantageous in that there is less scattering during spray coating, it is easy to obtain a uniform finish, and the surface can be finished smoothly. Usually, No. 7 silica sand is used.

In the present invention, the rubber powder used for the elastic layer is obtained by freeze-pulverizing waste tires, removing steel and lint, and separating the powder into particles with a particle size of 0.3 mm or less. An elastic layer containing rubber powder with a particle size of 0.3 mm or more has good cushioning properties, but the surface characteristics of the rubber powder tend to cause protrusions, which can be cut off or the upper color surface layer thickened to cover them. Problems arise when the ball has to be coated or the ball is irregular during play. In the present invention, since the particle size is regulated to 0.3 mm or less, the above-mentioned problems regarding the surface properties of the finished product are solved, and the spray method can be used as the coating method, which is advantageous for achieving a uniform finish.

In the present invention, the acrylic resin emulsion used for the color surface layer refers to an acrylic ester copolymer emulsion, and specifically, an acrylic ester homocopolymer emulsion, an acrylic ester-methacrylic ester copolymer emulsion, Examples include acrylic ester-styrene copolymer emulsion and acrylic ester-vinyl acetate copolymer emulsion, among which those with a Tg of -10 to +10°C are used. this
Using an acrylic resin emulsion in the Tg range,
Since the dried film is flexible, the loss of silica aggregate due to poor adhesion is prevented, and the adhesion to the elastic layer is also improved. Furthermore, since it can follow the deformation of the elastic layer, the collar surface layer will not crack or peel off.

In the present invention, the silica aggregate used for the color surface layer has a particle size of 100μ or less, for example, 8
Examples include fine silica sand to fine silica sand. If the particle size is 100 μm or less, irregularity of the ball during play on the tennis court can be suppressed, causing a moderate amount of slippage for the player, which is also advantageous in terms of physical fatigue.

In the present invention, the pigment used for the color surface layer may be either a normal inorganic pigment or an organic pigment, such as titanium oxide, red iron, yellow lead, titanium yellow, zinc chromate, cadmium yellow, lead cyanamide, chromium green. , chromium oxide green, pyridian, cobalt green, emerald green, manganese green, navy blue, ultramarine blue, cobalt blue, manganese blue, manganese violet, cobalt violet, and the like.

As shown in FIG. 1 of the accompanying drawings, the construction method of the present invention is to form a primer layer 2 on an asphalt concrete base 1 as necessary, and then to
The undercoat layer 3, the elastic layer 4, and the color surface layer 5 are laminated in this order to form a three-layer (3 to 5) structure.

The composition used to form the undercoat layer 3 is Tg-
SBR (preferably carboxylated) at 15 to -5°C
SBR) and silica aggregate with a particle size of 50 to 300μ, and the blending ratio of both is 250 to 350 parts, preferably 270 to 330 parts, of silica aggregate to 100 parts (parts by weight, same hereinafter) of solid content of SBR. It is sufficient to select within the range of . The silica aggregate can be mixed with SBR before construction, or it can be mixed as appropriate at the construction site. Additionally, appropriate amounts of conventional additives such as viscosity-adjusting thickeners (cellulose, water-soluble polyurethane, polyvinyl alcohol, etc.), fillers (calcium carbonate, clay, talc, etc.), and the above pigments may be added to the SBR as necessary. It may be mixed in advance,
Especially with pigments (usually 5-10% by weight of the composition)
By doing so, it is convenient to be able to judge the unevenness of the coating and the unevenness of the underlying asphalt concrete foundation. Furthermore, carboxylation
When SBR is used, dry film strength, physical properties, etc. can be improved by using a compound having a functional group reactive with the carboxyl group (for example, an epoxy resin). Such compositions are usually applied uniformly over the entire surface in two to three coats, for example, with a rubber rake or spray, at a coating weight of 500 to 1500 g/m ² .

The composition used to form the elastic layer 4 is Tg-
SBR (preferably carboxylated) at 15 to -5°C
SBR), waste tire rubber powder that has been crushed and classified to a particle size of 0.3mm or less, and silica aggregate with a particle size of 50 to 300μ. The SBR used here is the undercoat layer 3.
The SBR may be the same as or different from the SBR, but the same is more advantageous for the adhesion between both layers. The mixing ratio of the above three components is 80 to 130 parts of rubber powder, preferably 90 to 110 parts of rubber powder per 100 parts of solid content of SBR.
part, and 30 to 90 parts of silica aggregate, preferably 50 to
You can choose within the range of 70 copies. If the amount of rubber powder exceeds the above range, the elasticity will weaken over time, and if the amount of silica aggregate increases, the elasticity will decrease. In addition, the weight ratio of rubber powder and silica aggregate should normally be selected to be 100/50 to 100. If necessary, thickeners, fillers, fibers, etc. may be added to SBR in advance as described above, and rubber powder and silica aggregate may be added to this at the construction site, or these additives may be added to the SBR. All components may be mixed together before construction. In addition, in the case of silica aggregate, it is preferable to add and mix it at least at the construction site because, for example, secondary agglomerated rubber powder can be finely dispersed. In such a composition, the reason why rubber powder and silica aggregate are used together is that the silica aggregate is effective in dispersing the rubber powder, and also suppresses clogging during spraying, resulting in a good coating surface. The surface finish of The next process can be carried out without requiring more than one day of drying time during and/or after construction rain, which contributes to suppressing the occurrence of blisters. In addition, the elasticity or resilience of the ball after drying is comparable, and it also has the advantage of being less likely to change over time. Application amount is usually 2000 to 6000g/ ^m2
The ratio is selected so that the layer thickness after drying is 1.6 to 4.0 mm. In particular, from the viewpoint of elasticity and economy, applying the coating in 3 to 6 times at a coating amount of 4,000 to 5,000 g/m ² will provide uniform coating thickness and eliminate unevenness, so it is recommended to apply in 1 to 2 times. better than. As a coating method, a spray method is preferable because it provides a uniform thickness and a uniform surface finish. Furthermore, in this elastic layer 4, as in the undercoat layer 3, it is preferable to use an epoxy resin as a crosslinking agent in an amount of 5 to 10 parts per 100 parts of solid content of carboxylated SBR.

The composition used to form the color surface layer 5 is:
Acrylic resin emulsion with Tg -10~+10℃,
Consists of silica aggregate and pigment with a particle size of 100μ or less. When blending these ingredients, 40 parts of silica aggregate should be added to 100 parts of solid content of the acrylic resin emulsion.
-200 parts, preferably 80-150 parts. Pigments are usually mixed in an amount of 8 to 12 parts by mixing one or more of them to create a desired color, such as green inside the court and brick red outside the court, as seen on ordinary tennis courts. It's fine. Further, appropriate amounts of fillers, plasticizers, film-forming aids, thickeners, preservatives, antifreeze agents, etc. may be added as necessary. The color surface layer composition is used to impart required surface properties such as makeup and abrasion resistance to the surface of a tennis court, and usually has a coating amount of 500 to 1500 g/ ^m2.
It is applied in two to three times by spraying or the like.

According to the method of the present invention having the above-described structure, an excellent elastic paving material for tennis courts with little change over time in the coefficient of restitution and coefficient of friction of tennis balls can be obtained.

Next, the present invention will be specifically explained with reference to Examples.

Production example 1 (Undercoat layer composition) Carboxylated SBR (manufactured by Dainippon Ink and Chemicals, Luxstar 7310K, Tg-10℃) ...60 parts Calcium carbonate ...30 parts Pigment (chrome yellow) ...10 parts Thickening Agent...5 parts Silica aggregate (No. 7 silica sand)...100 parts Crosslinking agent (epoxy resin emulsion)...1 part Production example 2 (Elastic layer composition) Carboxylated SBR (same as production example 1)...70 parts Waste tire crushed rubber powder (100μ or less) ...30 parts Silica aggregate (No. 7 silica sand) ...30 parts Thickener ...5 parts Crosslinking agent (epoxy resin emulsion) ...5 parts Manufacturing example 3 (Color surface layer composition ) Acrylic resin emulsion (manufactured by Daicel Chemical Industries, Ltd., Cevian A, Tg -5℃) ... 60 parts calcium carbonate ... 10 parts pigment (red or chrome green)
...10 parts thickener ...5 parts silica aggregate (coarse-grained silica sand) ...30 parts Example 1 Approximately 200 g of primer (manufactured by Sunstar Giken Co., Ltd., Primer PC-1) was applied to the asphalt concrete base using a roller bucket. Apply once at / ^m2 . Next, the undercoat layer composition of Production Example 1 was applied twice within one day, once each in the vertical and horizontal directions (approximately 500 g/m ² ), while checking the unevenness and shading.
Next, about 1000 g/m ² of the elastic layer composition of Production Example 2 was added.
Spray it a total of 5 times over 2 days in the vertical, horizontal, and vertical directions at a ratio of . The next day, apply the color surface layer composition of Production Example 3 (red color and green color) to each desired location (red outside the coat, green inside the coat) once in the vertical and horizontal directions (approximately 500 g/m ² ).
Apply 2 coats each. 1.5 for color surface coating work
It took days. After drying, we sprinkled water to investigate whether it was raining or not, but no problem areas were found.

Next, the lines of the tennis court were drawn with white paint (Betaall 3000, manufactured by Sunstar Giken).

Test example (1) Adhesion: An attachment for adhesion testing was attached to the edge of the construction surface of the elastic paving material for tennis courts using epoxy resin adhesive, and the next day, the adhesion strength was measured using a Kenken-type tensile tester. Measure. Both 7Kg/cm ²
As a result, the ascontact base was destroyed.

(2) Coefficient of restitution of a tennis ball: Let a tennis ball fall naturally from a height of 250cm,
The coefficient of repulsion is determined from the height of the spring (h) at that time using the following formula.

The evaluation results are 0.74~ at all locations.
It was in the range of 0.76. Further, after using the coat of this example for 3 months, the coefficient of restitution was measured in the same manner, and all values remained within the above range and no change in the coefficient of restitution was observed.

(3) Coefficient of friction of a tennis ball: When a hard tennis ball with a weight inside it weighing 560 g is gently pulled horizontally across the court surface using a spring scale, the force (F) at which the ball starts to move is measured. Find the coefficient of friction using the formula.

Friction coefficient = F/560 As a result, the friction coefficient is in the range of 0.61 to 0.64, which is smaller than, for example, when using No. 8 or No. 7 silica sand as the silica aggregate for the collar surface layer, and is not slippery. Also, it is not slippery and is moderate. Note that no change in the friction coefficient was observed even after three months had passed.

(4) Water permeability: Calculate water permeability using a method similar to JIS 6910. The water permeability at the edge of this example coat is 0.5~
At 0.7 mm/24 hours, the water permeability of each layer alone in the laboratory was 2.4 mm/24 hours for the undercoat layer, 1.8 mm/24 hours for the elastic layer, and 0.65 mm/24 hours for the color surface layer.

In this way, the amount of water permeation decreases from the undercoat layer to the color surface layer, and it can be seen from this that even if rainwater penetrates, it is more likely to penetrate the lower layer, making it less likely that problems such as blistering will occur.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the laminated state of an example of an elastic paving material for tennis courts obtained by the method of the present invention, in which 1: asphalt concrete base, 3: undercoat layer, 4: elastic layer, 5 : Color surface layer.

Claims (1)

[Claims] 1. An undercoat layer on an asphalt concrete base,
In the construction method for forming an elastic paving material for tennis courts consisting of an elastic layer and a color surface layer, a styrene-butadiene copolymer latex with a glass transition temperature of -15 to -5°C and a particle size of 50 to -50°C is coated on the base.
A composition consisting of 300μ silica aggregate is applied to form an undercoat layer, and then a styrene-butadiene copolymer latex with a glass transition temperature of -15 to -5°C and a particle size of 0.3 mm or less is applied on the undercoat layer. Waste tire rubber powder and particle size crushed and classified into
A composition consisting of silica aggregate of 50 to 300μ is applied to form an elastic layer, and finally an acrylic resin emulsion with a glass transition temperature of -10 to +10°C, silica aggregate with a particle size of 100μ or less, and A method of constructing an elastic paving material for tennis courts, characterized by forming a colored surface layer by applying a composition comprising pigments. 2. The construction method according to item 1, wherein the weight ratio of latex solid content to silica aggregate in the undercoat layer is 100/250 to 350. 3. The construction method according to item 1, wherein the weight ratio of latex solid content, rubber powder, and silica aggregate in the elastic layer is 100/80 to 130/30 to 90. 4. The construction method according to item 1 above, wherein the weight ratio of the emulsion solid content to the silica aggregate in the color surface layer is 100/40 to 200. 5 The coating amount of each of the three layers is 500 to 500% for the undercoat layer.
1500 g/m ² , the elastic layer 2000 to 6000 g/m ² and the color surface layer 500 to 1500 g/m ² .