Colored elastic chips, method for manufacturing the same, and elastic pavement

Abstract

This invention provides a colored elastic chip that prevents the hardening of paving binders from becoming too slow when using non-yellowing or low-yellowing urethane binders as paving binders. [Solution] A colored elastic chip 11 comprises a granular elastic core 11a and a colored coating 11b for covering and coloring the surface of the elastic core 11a. The colored coating 11b contains a coloring agent, a urethane-based coloring binder, and a urethane catalyst, and the amount of urethane catalyst contained in the colored coating 11b is 0.5 parts by weight or more per 100 parts by weight of the elastic core.

Description

Technical Field

[0001] The present invention relates to a colored elastic chip for paving and a method for manufacturing the same. The present invention also relates to an elastic paving using the colored elastic chip.

Background Art

[0002] In kindergartens, parks, etc., in order to reduce the impact applied to the body from the road surface or floor surface when walking or falling, etc., the road surface or floor surface is covered with an elastic paving having elasticity. As the elastic paving, a paving using granular elastic chips (rubber chips) formed of an elastic material is widely used. As this type of elastic chip, a colored elastic chip obtained by coloring the surface of a granular elastic core or a color elastic chip (for example, an EPDM color chip, etc.) formed of an elastic material kneaded with a coloring agent is known. By using the colored elastic chip or the color elastic chip, the elastic paving can be finished in various colors and designs.

[0003] Among these, as the colored elastic chip, for example, the colored rubber chip 9 described in Patent Document 1 is exemplified. This colored rubber chip 9 includes a dark-colored rubber chip material 1 such as a waste tire chip, a base coloring film 6 provided on the surface of the rubber chip material 1, and a finish coloring film 7 provided on the upper layer of the base coloring film 6. In this colored rubber chip 9, by providing the base coloring film 6, the base color of the rubber chip material 1 (waste tire chip) can be made difficult to be visually recognized from the outside, and the color of the finish coloring film 7 can be made to develop clearly.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, elastic pavement using elastic chips is broadly known to be divided into two types: on-site construction type and pre-molded type. The on-site construction type is an elastic pavement in which elastic chips and a paving binder are mixed and spread on the surface to be paved, and then hardened on-site. The pre-molded type is an elastic pavement in which elastic chips and a paving binder are mixed, placed in a mold, and the elastic paving material is hardened in advance and then laid on the surface to be paved. In both the on-site construction type and the pre-molded type, urethane-based binders are often used as the paving binder, and among them, MDI-based urethane binders using diphenylmethane diisocyanate (MDI) as the isocyanate are widely used.

[0006] However, MDI-based urethane binders have the problem of being prone to yellowing due to ultraviolet light. For this reason, even if a base colored coating 6 is provided to ensure that the color of the colored coating 7 is vividly developed, as in the colored rubber chip 9 of Patent Document 1, if an MDI-based urethane binder is used as a paving binder, the paving binder may yellow over time, and the color tone of the elastic pavement may differ from the desired one.

[0007] In this regard, among urethane binders, there are known types such as non-yellowing urethane binders that hardly yellow even when exposed to ultraviolet light, and low-yellowing urethane binders that are less prone to yellowing than MDI-based urethane binders. Examples of non-yellowing urethane binders include IPDI-based urethane binders that use isophorone diisocyanate (IPDI) as the isocyanate. Examples of low-yellowing urethane binders include HDI-based urethane binders that use hexamethylene diisocyanate (HDI) as the isocyanate.

[0008] However, non-yellowing urethane binders and low-yellowing urethane binders tend to harden more slowly than MDI-based urethane binders. Therefore, if non-yellowing urethane binders or low-yellowing urethane binders are used as paving binders, the elastic pavement used in on-site construction may not harden properly after construction, or the molding of the elastic paving material used in pre-molded elastic pavement may take too long, potentially reducing work efficiency. The inventors' research revealed that the tendency for non-yellowing urethane binders and low-yellowing urethane binders to harden slowly was particularly pronounced when colored elastic chips were used.

[0009] The present invention was made to solve the above problems and provides a colored elastic chip that prevents the hardening of paving binder from becoming too slow when using a non-yellowing urethane binder or a low-yellowing urethane binder as a paving binder. Another objective of the present invention is to provide a method for manufacturing this colored elastic chip and an elastic pavement using this colored elastic chip. [Means for solving the problem]

[0010] The above issues are, A granular elastic core, A colored coating for covering and coloring the surface of the elastic core A colored elastic tip equipped with, The colored coating comprises a coloring agent, a urethane-based coloring binder, and a urethane catalyst. This problem is solved by providing a colored elastic chip in which the amount of urethane catalyst contained in the colored coating is 0.5 parts by weight or more per 100 parts by weight of the elastic core.

[0011] This colored elastic tip is A granular elastic core, A colored coating for covering and coloring the surface of the elastic core A method for manufacturing a colored elastic chip equipped with, The process includes adding a coloring agent, a urethane-based coloring binder, and a urethane catalyst to an elastic core and stirring and mixing them to form a colored coating. The amount of urethane catalyst added is 0.5 parts by weight or more per 100 parts by weight of elastic core. Manufacturing method for colored elastic chips It can be manufactured by [method].

[0012] As a result of the inventors' investigations, it was found that by setting the amount of urethane catalyst contained in the colored coating to 0.5 parts by weight or more per 100 parts by weight of elastic core, it was possible to prevent the hardening of the paving binder from becoming too slow, even when using a non-yellowing type urethane binder or a low-yellowing type urethane binder as the paving binder. This effect is presumed to be obtained by either the urethane catalyst contained in the colored coating migrating to the paving binder and accelerating its hardening, or by remaining in the colored coating and accelerating the hardening of the paving binder.

[0013] Furthermore, as will be shown in later examples, when using non-yellowing urethane binders or low-yellowing urethane binders as paving binders, it can be difficult to improve the physical properties of elastic pavement (e.g., tensile strength, elongation, etc.). However, by using the colored elastic chips according to the present invention, the physical properties of elastic pavement can be improved without adding additives to the paving binder.

[0014] In the colored elastic chip according to the present invention, it is preferable that the amount of urethane catalyst contained in the colored coating is 16.5 parts by weight or more per 100 parts by weight of the coloring binder. This makes it easier to obtain the above effects.

[0015] The urethane catalyst contained in the colored coating is not limited to any specific type. While amine-based and metal-based catalysts are known as urethane catalysts, concerns exist regarding the environmental impact of metal-based catalysts. Therefore, it is preferable to use an amine-based catalyst as the urethane catalyst.

[0016] The colored elastic chip according to the present invention includes a colored elastic chip and a paving binder, and the paving binder can be suitably used for elastic paving which is a non-yellowing urethane binder or a difficult-to-yellow urethane binder. Thereby, the significance of the colored elastic chip according to the present invention can be enhanced.

Effect of the Invention

[0017] As described above, according to the present invention, it is possible to provide a colored elastic chip that can prevent the curing of the paving binder from being excessively delayed when a non-yellowing urethane binder or a difficult-to-yellow urethane binder is used as the paving binder. In addition, it is also possible to provide a method for manufacturing this colored elastic chip and an elastic paving using this colored elastic chip.

Brief Description of the Drawings

[0018] [Figure 1] It is a schematic cross-sectional view of the elastic paving of this embodiment.

Modes for Carrying Out the Invention

[0019] 1. Overview A preferred embodiment of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an elastic paving 100 of this embodiment. As shown in FIG. 1, the elastic paving 100 of this embodiment includes a primer layer 110 applied to a paved surface S and an elastic layer 120 laminated on the upper side (outer side) of the primer layer 110. The primer layer 110 is for firmly bonding the paved surface S and the elastic layer 120. The elastic layer 120 is formed by binding a large number of elastic chips 10 with a paving binder 20 and has cushioning properties. There are voids between the elastic chips 10, whereby the elastic layer 120 has water permeability.

[0020] The elastic chips 10 constituting the elastic layer 120 include colored elastic chips 11. As shown in Figure 1, the colored elastic chip 11 is an elastic chip comprising a granular elastic core 11a and a colored coating 11b for covering and coloring the surface of the elastic core 11a. The colored coating 11b contains a coloring agent, a coloring binder which is a urethane-based binder, and a urethane catalyst.

[0021] The elastic pavement 100 of this embodiment shown in Figure 1 is a field-construction type elastic pavement. This elastic pavement 100 can be constructed by going through a primer layer formation process and an elastic layer formation process.

[0022] The primer layer formation step is a step of forming a primer layer 110 by applying a primer to the surface to be paved S. The elastic layer formation step is a step of forming an elastic layer 120 on top of the primer layer 110 formed in the primer layer formation step. In the elastic layer formation step in this embodiment, a paving composition is prepared by mixing elastic chips 10 containing colored elastic chips 11 with a paving binder 20 before hardening, and this paving composition is spread on top of the primer layer 110, compacted with a roller or the like, and the details are finished with a trowel or the like. After that, once the paving binder 20 hardens, the elastic layer formation step is completed, and the construction of the elastic pavement 100 is completed.

[0023] In this embodiment, a non-yellowing urethane binder or a low-yellowing urethane binder is used as the paving binder 20. This makes it possible to prevent the paving binder 20 from yellowing even when the elastic pavement 100 is exposed to ultraviolet light, and to maintain the color tone of the elastic pavement 100 in a state close to that at the time of construction. However, non-yellowing urethane binders and low-yellowing urethane binders tend to take longer to harden than MDI-based urethane binders. If the hardening speed of the paving binder 20 is too slow, construction defects such as deformation of the elastic pavement 100 due to people walking on it before the paving binder 20 has hardened, or debris adhering to the surface of the elastic pavement 100, are more likely to occur.

[0024] In this regard, the present inventors have found that by adding an excess amount of urethane catalyst to the colored coating 11b of the colored elastic chips 11 constituting the elastic layer 120, the hardening speed of the paving binder 20 can be accelerated even without adding a urethane catalyst to the paving binder 20. Specifically, they have found that by setting the amount of urethane catalyst contained in the colored coating 11b to 0.5 parts by weight or more per 100 parts by weight of elastic core 11, the hardening of the paving binder 20 can be prevented from becoming too slow, even when using a non-yellowing type urethane binder or a low-yellowing type urethane binder as the paving binder 20. In addition, as will be shown in later examples, they have also found that the physical properties of the elastic pavement 100 can be improved. Generally, in many cases, the urethane catalyst itself is not added to the colored coating of colored elastic chips, and even when it is added, the amount of urethane catalyst per 100 parts by weight of elastic core is at most about 0.01 to 0.05 parts by weight. Therefore, the colored coating 11b of the colored elastic chip 11 in this embodiment contains an excessive amount of urethane catalyst (according to common technical knowledge).

[0025] Incidentally, if we only consider accelerating the hardening of the paving binder 20, it might seem that the urethane catalyst could be added directly to the paving binder 20 rather than to the colored coating 11b of the colored elastic chips 11. However, urethane-based paving binders 20 are usually packaged in small batches to prevent unintended hardening, and it is common to open a new batch each time they are used. If the urethane catalyst is added to the paving binder 20, it would be necessary to measure and add the urethane catalyst each time the paving binder 20 is opened, which is time-consuming. In this respect, adding the urethane catalyst to the colored coating 11b eliminates this hassle. In addition, in the manufacturing method of the colored elastic chips 11, which will be explained later, the hardening of the colored coating 11b can also be accelerated, thus making the manufacturing of the colored elastic chips 11 more efficient. For these reasons, in this embodiment, the urethane catalyst is added to the colored coating 11b rather than to the paving binder 20.

[0026] In addition, while colored elastic chips 11 can be used alone as the elastic chips 10 included in the elastic layer 120, in this embodiment, as shown in Figure 1, a mixture of colored elastic chips 11 and other elastic chips 12 is used as the elastic chips 10. The specific type of other elastic chips 12 is not limited. For example, colored elastic chips formed from an elastic material into which a coloring agent has been kneaded can be used as the other elastic chips 12. This makes it possible to finish the texture of the elastic layer 120 to a more natural feel. Furthermore, even if the colored coating 11b of the colored elastic chips 11 peels off due to wear or the like, the overall appearance of the elastic layer 120 will not change significantly.

[0027] When a mixture of colored elastic chips 11 and other elastic chips 12 is used as the elastic chip 10, the proportion of colored elastic chips 11 in the elastic chip 10 is not limited. From the viewpoint of obtaining the above effects, it is preferable that the proportion of colored elastic chips 11 in the elastic chip 10 be 50% by weight or less. However, one of the purposes of using colored elastic chips is cost reduction, and if the proportion of colored elastic chips 11 is too small, it may be difficult to obtain the cost reduction effect. For this reason, it is preferable that the proportion of colored elastic chips 11 in the elastic chip 10 be 20% by weight or more, and more preferably 30% by weight or more.

[0028] Furthermore, in this embodiment shown in Figure 1, the elastic layer 120 forms the outermost layer of the elastic pavement 100. However, in other embodiments, a protective layer to protect the elastic layer 120, or an anti-slip layer to enhance slip resistance, etc., can be provided on the upper side (outside) of the elastic layer 120. In yet another embodiment, another layer (for example, a cushion layer to enhance the impact resistance of the elastic pavement 100) can be provided between the paved surface S and the primer layer 110, or between the primer layer 110 and the elastic layer 120.

[0029] 2. Colored elastic tip As already mentioned, the colored elastic chip 11 comprises an elastic core 11a and a colored coating 11b. The size of the colored elastic chip 11 is not limited, but if it is too large, the surface of the elastic layer 120 of the elastic pavement 100 may become uneven, potentially resulting in poor walking comfort. For this reason, the size of the colored elastic chip 12 is preferably 4 mm or less, and more preferably 3.5 mm or less. However, if the colored elastic chip 11 is too small, the spaces between the colored elastic chips 11 may become too close together (making it difficult to create voids between the colored elastic chips 11), potentially reducing the water permeability of the elastic layer 120. For this reason, the size of the colored elastic chip 11 is preferably 0.5 mm or more, and more preferably 1 mm or more.

[0030] 2.1 Elastic core The elastic core 11a is not limited in material as long as it is a granular material having rubber-like elasticity. Examples of materials that can be used for the elastic core 11a include urethane elastomers (for example, ester-based urethane elastomers mainly composed of polyester polyols and isocyanates, or ether-based urethane elastomers mainly composed of polyether-based polyols and isocyanates), ethylene propylene rubber (EPDM), natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR), and other elastic materials. In this embodiment, a thermosetting urethane elastomer is used as the elastic core 11a.

[0031] The elastic core 11a may be formed from virgin rubber, but in this embodiment, the elastic core 11a is manufactured from waste materials (such as waste urethane elastomer or waste rubber from waste tires). Specifically, granular elastic core 11a is prepared by crushing the waste materials in a crusher. This reduces the environmental impact of manufacturing the colored elastic chips 11 and also reduces costs.

[0032] 2.2 Colored coating As already mentioned, the colored coating 11b contains a coloring agent (pigment), a coloring binder which is a urethane-based binder, and a urethane catalyst.

[0033] The type of coloring agent (pigment) is not limited, but it is preferably a heat-shielding pigment. This enhances the heat-shielding performance of the colored elastic chip 11. Various pigments with heat-shielding properties can be used as heat-shielding pigments, but those with high reflectivity to infrared light (infrared-reflective heat-shielding pigments) are particularly preferred.

[0034] The specific type of coloring binder is not limited to urethane-based binders. Either a one-component or two-component binder can be used, but in this embodiment, a one-component binder is employed. While moisture-curing binders and heat-curing binders are known as one-component binders, it is preferable to use a moisture-curing binder. This allows for the formation of the colored coating 11b with simple equipment in the manufacturing method of the colored elastic chip 11 described later.

[0035] Urethane-based binders, which are used as coloring binders, come in a variety of types depending on the type of isocyanate they contain. Examples of urethane-based binders include MDI-based urethane binders using diphenylmethane diisocyanate (MDI), TDI-based urethane binders using tolylene diisocyanate (TDI), HDI-based urethane binders using hexamethylene diisocyanate (HDI), XDI-based urethane binders using xylylene diisocyanate (XDI), and IPDI-based urethane binders using isophorone diisocyanate (IPDI). In this embodiment, a one-component moisture-curing type MDI-based urethane binder is used as the coloring binder.

[0036] The urethane catalyst is not limited to any specific type as long as it can accelerate the curing of the urethane binder. Examples of urethane catalysts include amine-based catalysts and metal-based catalysts, but metal-based catalysts raise concerns about their environmental impact. Therefore, it is preferable to use amine-based catalysts. Examples of amine-based catalysts include tertiary amine compounds (aliphatic tertiary amines, aromatic tertiary amines, etc.). Examples of tertiary amine compounds include bis(2-dimethylaminoethyl) ether, N,N,N',N'-tetramethylhexamethylenediamine, N,N,N',N''-pentamethyldiethylenetriamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N'-tetramethylethylenediamine, triethylenediamine, dimethylethanolamine, dimethylaminoethoxyethanol, and tetramethylguanidine. The urethane catalyst can be used alone or in combination of two or more types. In this embodiment, bis(2-dimethylaminoethyl) ether, an aliphatic tertiary amine, is used as the urethane catalyst.

[0037] The amount of urethane catalyst contained in the colored coating 11b is 0.5 parts by weight or more per 100 parts by weight of elastic core 11. Preferably, the amount of urethane catalyst contained in the colored coating 11b is 0.6 parts by weight or more per 100 parts by weight of elastic core 11. Furthermore, preferably, the amount of urethane catalyst contained in the colored coating 11b is 16.5 parts by weight or more, and more preferably 20 parts by weight or more, per 100 parts by weight of coloring binder. This allows for a significant acceleration of the hardening of the paving binder 20 during the construction of the elastic layer 120 (Figure 1).

[0038] However, if the amount of urethane catalyst contained in the colored coating 11b is too large, the paving binder 20 may harden too quickly when the colored elastic chips 11 are mixed with the paving binder 20, which may prevent the formation of the elastic layer 120 (Figure 1) from working properly. For this reason, the amount of urethane catalyst contained in the colored coating 11b is preferably 1.5 parts by weight or less, more preferably 1 part by weight or less, and even more preferably 0.8 parts by weight or less, per 100 parts by weight of elastic core 11. Furthermore, the amount of urethane catalyst contained in the colored coating 11b is preferably 50 parts by weight or less, more preferably 33 parts by weight or less, and even more preferably 26 parts by weight or less, per 100 parts by weight of colored binder.

[0039] 2.3 Method for manufacturing colored elastic chips The manufacturing method for the colored elastic chip 11 of this embodiment includes a step of forming a colored film by adding a coloring agent, a coloring binder which is a urethane-based binder, and a urethane catalyst to an elastic core 11a and stirring and mixing them. This allows the surface of the elastic core 11a to be coated with a colored film 11b and colored.

[0040] More specifically, first, the elastic core 11a, the coloring agent (pigment), and the one-component moisture-curing coloring binder are added to the mixer in that order and stirred. Next, when the pigment and coloring binder have settled over the entire surface of the elastic core 11a, the urethane catalyst is added to the mixer and stirred. Once the coloring binder has hardened and the surface of the colored film 11b is no longer sticky, the production of the colored elastic chip 11 is complete. In this way, by adding the urethane catalyst after the coloring binder, even if a relatively easy-to-harden MDI-based urethane binder is used as the coloring binder, it is possible to form a nearly uniform colored film 11b on the surface of the elastic core 11a.

[0041] The amount of pigment added to the elastic core 11a is not limited. The amount of pigment added to 100 parts by weight of elastic core 11a is preferably about 1 to 5 parts by weight, and more preferably about 2 to 3 parts by weight.

[0042] The amount of coloring binder added to the elastic core 11a is not limited. However, if the amount of coloring binder added is too small, the surface of the elastic core 11a may not be sufficiently covered, and if the amount of coloring binder added is too large, the colored film 11b may become thick and uneven, potentially resulting in a poor texture of the colored elastic chip 11. For this reason, the amount of coloring binder added to 100 parts by weight of elastic core 11a is preferably about 1 to 10 parts by weight, and more preferably about 2 to 5 parts by weight. In this embodiment, the amount of coloring binder added to 100 parts by weight of elastic core 11a is about 3 parts by weight.

[0043] The amount of urethane catalyst added to the elastic core 11a is preferably 0.5 parts by weight or more, and more preferably 0.6 parts by weight or more, per 100 parts by weight of elastic core 11. Furthermore, the amount of urethane catalyst added to the coloring binder is preferably 16.5 parts by weight or more, and more preferably 20 parts by weight or more, per 100 parts by weight of coloring binder.

[0044] On the other hand, the amount of urethane catalyst added to the elastic core 11a is preferably 1.5 parts by weight or less, more preferably 1 part by weight or less, and even more preferably 0.8 parts by weight or less, per 100 parts by weight of the elastic core 11. Furthermore, the amount of urethane catalyst added to the coloring binder is preferably 50 parts by weight or less, more preferably 33 parts by weight or less, and even more preferably 26 parts by weight or less, per 100 parts by weight of the coloring binder.

[0045] 3. Colored elastic tips The colored elastic chip 12 is an elastic chip in which a coloring agent is kneaded into the interior (formed from an elastic raw material into which a coloring agent such as a pigment is kneaded). By using this colored elastic chip 12 in a mixture with the colored elastic chip 11, even when the surface layer of the elastic pavement 100 wears down and the colored coating 11b of the colored elastic chip 11 on the surface layer peels off, it is possible to maintain the color tone of the elastic pavement 100 in a state close to that at the time of construction. The size of the colored elastic chip 12 can be the same configuration as that of the colored elastic chip 11.

[0046] The material of the colored elastic chip 12 is not limited. The colored elastic chip 12 can be made from rubber chips or from thermoplastic elastomers molded into chips. In this embodiment, non-foamed rubber chips made from ethylene propylene diene rubber (EPDM) are used as the colored elastic chip 12. EPDM has excellent rebound elasticity and hydrolysis resistance. Therefore, by using EPDM rubber chips as the colored elastic chip 12, the cushioning properties of the elastic pavement 100 can be enhanced.

[0047] 4. Binder for paving As the paving binder 20 constituting the elastic layer 120, a non-yellowing or low-yellowing urethane binder is used. As the non-yellowing or low-yellowing urethane binder, for example, a urethane-based binder using aliphatic isocyanate or alicyclic isocyanate as the isocyanate can be adopted.

[0048] Examples of non-yellowing urethane binders include IPDI-based urethane binders using isophorone diisocyanate (IPDI). Examples of non-yellowing urethane binders include HDI-based urethane binders using hexamethylene diisocyanate (HDI), XDI-based urethane binders using xylylene diisocyanate (XDI), hydrogenated XDI-based urethane binders using hydrogenated xylylene diisocyanate (hydrogenated XDI), H6XDI-based urethane binders using bis(isocyanate-methyl)cyclohexane (H6XDI), H12MDI-based urethane binders using dicyclohexylmethane-4,4'-diisocyanate (H12MDI), and TMXDI-based urethane binders using tetramethyl xylylene diisocyanate (TMXDI). Non-yellowing or non-yellowing urethane binders can be used individually or in combination of two or more types. Considering the results of later examples, it is most preferable to use an IPDI-based urethane binder containing isophorone diisocyanate (IPDI) alone as a non-yellowing urethane binder.

[0049] The amount of paving binder 20 in the elastic layer 120 (the amount of paving binder 20 added to the elastic chips 10) is not limited, but if there is too much, the elastic layer 120 may become too hard or its water permeability may be reduced, and if there is too little, it may be difficult to increase the strength of the elastic layer 120. For this reason, the amount of paving binder 20 added to 100 parts by weight of elastic chips 10 is preferably 15 parts by weight or more and 30 parts by weight or less, and more preferably 20 parts by weight or more and 25 parts by weight or less.

[0050] 5. Other Embodiments In the embodiments described above, the colored elastic chips 11 were used in a field-construction type elastic pavement 100 (Figure 1). However, the colored elastic chips 11 can also be used in a pre-molded type elastic pavement.

[0051] In pre-formed elastic pavement, the elastic paving material (not shown) is first molded. The elastic paving material is molded by mixing elastic chips 10 containing colored elastic chips 11 with a paving binder 20 to obtain a paving composition, placing the mixture into a mold, and hardening the paving binder 20. In pre-formed elastic pavement, it is preferable to reduce the amount of paving binder 20 added to the elastic chips 10 compared to the field-construction type. Specifically, the amount of paving binder 20 added to 10 parts by weight or more, and more preferably 2 parts by weight or more, and 5 parts by weight or less, per 100 parts by weight of elastic chips 10. The paving binder 20 can be hardened at room temperature and pressure, but it is preferable to harden it by applying heat and pressure. The shape of the elastic paving material is not limited, but it can be, for example, tile-shaped or block-shaped.

[0052] By laying the resulting elastic paving material on a surface S to be paved, to which a urethane-based adhesive has been pre-applied, a pre-molded type of elastic pavement can be formed. Furthermore, for parts other than those described herein, the same configuration as that described for the field-construction type of elastic pavement 100 can be adopted for the pre-molded type of elastic pavement. [Examples]

[0053] The present invention will be explained in more detail below with more specific experimental examples, but the technical scope of the present invention is not limited to the following examples.

[0054] [Manufacturing of colored elastic tips] (Colored elastic tip A) Polyurethane elastomer waste was crushed in a pulverizer and sieved to a diameter of 1 mm to 3.35 mm to prepare elastic cores. 100 parts by weight of the obtained elastic cores were placed in a mixer, and 3 parts by weight of infrared reflective heat-shielding pigment and 3 parts by weight of coloring binder (BASF INOAC Polyurethane's MDI-based polyurethane binder "Formlight EC-1213") were added and stirred and mixed at room temperature for a while. When the pigment and coloring binder had settled on the surface of the elastic cores, 0.05 parts by weight of bis(2-dimethylaminoethyl) ether, an amine-based catalyst, was added to the mixer and stirred and mixed further. After a few minutes, the coloring binder hardened and the formation of the colored film was completed, and colored elastic chip A was completed.

[0055] (Colored elastic tip B) Colored elastic tip B was manufactured using the same procedure as for colored elastic tip A, except that the amount of bis(2-dimethylaminoethyl) ether, an amine-based catalyst, was 0.5 parts by weight per 100 parts by weight of elastic core.

[0056] (Colored elastic tip C) Colored elastic tip B was manufactured using the same procedure as for colored elastic tip A, except that the amount of bis(2-dimethylaminoethyl) ether, an amine-based catalyst, was 1 part by weight per 100 parts by weight of elastic core.

[0057] [Field Construction Test] To investigate the effectiveness of on-site construction type elastic pavement, on-site construction tests were conducted according to the following procedure. First, 50 parts by weight of colored elastic chips obtained in the above [manufacturing of colored elastic chips] and 50 parts by weight of EPDM rubber chips with a diameter of 1 mm to 3.35 mm were mixed, and 22.5 parts by weight of paving binder were further mixed to obtain a paving composition. The combinations of colored elastic chips and paving binder were as shown in Table 1. The obtained paving composition was spread to a thickness of approximately 7 mm in a rectangular frame approximately 150 mm long and 150 mm wide, compacted with a roller, and finished with a trowel. It was left to stand at room temperature and pressure, and the hardening state of the paving composition (elastic pavement) was checked at 16 hours, 32 hours, and 48 hours after completion of construction. The results are shown in Table 1. In Table 1, "Workability" is indicated as follows: "○" if compaction and trowel finishing could be done without problems; "△" if the paving binder began to harden before completion of work, making compaction and trowel finishing difficult; and "×" if the paving binder hardened before completion of work, making compaction and trowel finishing impossible. Furthermore, "Hardening State" is indicated as follows: "○" if hardening is complete; "△" if hardening has progressed to some extent but still feels slightly tacky; and "×" if hardening is not complete and still feels sticky.

[0058] Furthermore, the Type E hardness (rubber hardness measured at 25°C using a Type E durometer in accordance with JIS K6253; the same applies hereinafter) was measured for the elastic pavement after 48 hours of standing. In addition, the elastic pavement after 48 hours of standing was removed from the frame and punched out in the shape of a No. 1 dumbbell to prepare test specimens. Using these test specimens, the tensile strength and elongation were measured at a tensile speed of 500 mm / min in accordance with JIS K6251. The measurement results for Type E hardness, tensile strength, and elongation are shown in Table 1. Note that physical property measurements were not performed for pavement using IPDI (summer) as the binder.

[0059] [Table 1]

[0060] The details of the abbreviations for paving binders in Table 1 are as follows: MDI: H&K Corporation's MDI-type urethane binder "Hi-Ad 4146 (winter type)" IPDI (Winter): IPDI-type urethane binder "Chiproad (Winter)" manufactured by Shikoku Chemicals Building Materials Co., Ltd. IPDI (Summer): IPDI-type urethane binder "Chip Road (Summer Use)" manufactured by Shikoku Chemicals Building Materials Co., Ltd. HDI: BASF INOAC Polyurethane's HDI-type urethane binder "Foamlight EC-1220"

[0061] As shown in Table 1, when using colored elastic chip A containing 0.05 parts by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 1-4), when using non-yellowing or low-yellowing urethane binders (IPDI-type urethane binders / HDI-type urethane binders) as paving binders, hardening was not completed after 32 hours post-application, and hardening only occurred after 48 hours. Furthermore, physical properties such as tensile strength and elongation were not very good.

[0062] In contrast, when using colored elastic chip B containing 0.5 parts by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 5-8), or when using colored elastic chip C containing 1 part by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 9-12), it was shown that curing was completed as early as 16 hours after application, even when using a non-yellowing or low-yellowing urethane binder for paving. Furthermore, it was shown that physical properties such as tensile strength and elongation improved, particularly when using colored elastic chip B, or when using colored elastic chip C with an IPDI-based urethane binder.

[0063] [Elastic paving material molding test] To investigate the effectiveness of pre-molded elastic pavement, an elastic pavement material molding test was conducted according to the following procedure. First, 50 parts by weight of colored elastic chips obtained in the above [Production of Colored Elastic Chips] were mixed with 50 parts by weight of EPDM rubber chips with a diameter of 1 mm to 3.35 mm, and then 3 parts by weight of pavement binder were further mixed to obtain a pavement composition. The combinations of colored elastic chips and pavement binder were as shown in Table 2. The obtained pavement composition was spread in a rectangular mold approximately 300 mm long and 300 mm wide, and subjected to a temperature of 160°C and a pressure of 150 kg / cm². 2 Under these conditions, a tile-like elastic paving material with a thickness of approximately 10 mm was molded by pressing for 4 minutes. The results are shown in Table 2. In Table 2, "Moldability" is indicated as "○" if the paving composition could be laid without any problems within the rectangular mold, and "×" if the paving binder hardened before the paving composition could be laid within the rectangular mold, making laying impossible. Furthermore, "Hardening State" is indicated as "○" if the elastic paving material had hardened completely, and "△" if the elastic paving material had hardened to some extent but still had a slight tackiness.

[0064] Furthermore, the Type E hardness of the molded elastic paving material was measured. In addition, test specimens were prepared by punching out the molded elastic paving material into a No. 1 dumbbell shape. Using these test specimens, the tensile strength and elongation were measured at a tensile speed of 500 mm / min in accordance with JIS K6251. The measurement results for Type E hardness, tensile strength, and elongation are shown in Table 2.

[0065] [Table 2]

[0066] As shown in Table 2, when using colored elastic chip A containing 0.05 parts by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 13-15), the hardening of the elastic pavement material was insufficient when a non-yellowing urethane binder (IPDI-type urethane binder) was used as the pavement binder. Furthermore, when a low-yellowing urethane binder (HDI-type urethane binder) was used as the pavement binder, the elastic pavement material hardened, but its physical properties (elongation) were not very good.

[0067] In contrast, when using colored elastic chip B containing 0.5 parts by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 16-18), or when using colored elastic chip C containing 1 part by weight of urethane catalyst per 100 parts by weight of elastic core (Tests 19-21), it was shown that the elastic pavement material hardened properly even when using a non-yellowing or low-yellowing urethane binder for pavement. Furthermore, it was shown that the physical properties of the elastic pavement, such as tensile strength and elongation, improved. [Explanation of Symbols]

[0068] 10 elastic tips 11 Colored Elastic Tips 11a Elastic core 11b Colored coating 12 Other elastic tips (colored elastic tips) 20 Paving binders 100 Elastic Pavement 110 Primer layer 120 Elastic layer S Paved surface

Claims

1. A granular elastic core, A colored coating for covering and coloring the surface of the elastic core A colored elastic tip equipped with, The colored coating comprises a coloring agent, a urethane-based coloring binder, and a urethane catalyst. A colored elastic chip in which the amount of urethane catalyst contained in the colored coating is 0.5 parts by weight or more per 100 parts by weight of the elastic core.

2. The colored elastic chip according to claim 1, wherein the amount of urethane catalyst contained in the colored film is 16.5 parts by weight or more per 100 parts by weight of the coloring binder.

3. The colored elastic chip according to claim 1, wherein the urethane catalyst is an amine-based catalyst.

4. A granular elastic core, A colored coating for covering and coloring the surface of the elastic core A method for manufacturing a colored elastic chip equipped with, The process includes adding a coloring agent, a urethane-based coloring binder, and a urethane catalyst to an elastic core and stirring and mixing them to form a colored coating. The amount of urethane catalyst added is 0.5 parts by weight or more per 100 parts by weight of elastic core. A method for manufacturing colored elastic chips.

5. A colored elastic chip according to any one of claims 1 to 3 and a paving binder are included. The paving binder is a non-yellowing urethane binder or a low-yellowing urethane binder. Elastic pavement.

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