JP3388910B2 - Asphalt mixture mixed with elastic powder rubber - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregate for asphalt mixture and an asphalt mixture for recycling waste rubber of used tires and industrial waste. More specifically, elastic powder rubber is manufactured from used rubber such as used tires, belts and window frame rubber (hereinafter referred to as “waste rubber”), and its surface is subjected to specific chemical treatment and reused as aggregate for asphalt mixture. It is a technology to do. From the viewpoint of the global environment, it is considered that the used waste rubber is reused as a recycled product that has a smaller environmental load than it is reused as a fuel.

If there is a material suitable as a paving material and its treatment technology is available, its reuse greatly promotes material circulation and contributes greatly to global environmental conservation, and the limited use of road materials can be expected greatly. Its reuse as aggregate in the asphalt mixture can process large amounts of waste rubber. In addition, it is a recycling technology that is expected globally because it is economically feasible.

[0003]

2. Description of the Related Art Conventionally, waste rubber is reused in road pavement by mixing fine powder rubber with asphalt to modify the asphalt. Further, granular rubber chips are mixed into the asphalt mixture as an additive material of 2 to 3% and used as a freeze-suppressing pavement. At such a level, it is not possible to expect the amount of waste rubber to be consumed for reuse, and in order to consume a larger amount of waste rubber, it is necessary to mix a large amount of it into the asphalt mixture as paving aggregate. Become.

When a large amount of waste rubber elastic powder rubber is mixed in the asphalt mixture, shock absorption effect, slip resistance,
Wear resistance and noise reduction effects of traveling vehicles can be expected to be great, but due to low adhesion between elastic powder rubber and asphalt, there is concern about uneven compaction of the mixture due to reduced adhesion, resulting in strength and durability. It is not used as a pavement aggregate because it causes a problem in its property.

[0005]

The quality required for the aggregate of the asphalt mixture depends on appropriate particle size, wear resistance, and
It has excellent durability and slip resistance, and when it is mixed with asphalt, it has excellent adhesion to asphalt. Abrasion resistance, durability and slip resistance are excellent because of the inherent qualities of elastic powder rubber. However, the adhesiveness with asphalt is low and not satisfactory.

An object of the present invention is to improve the adhesive force with asphalt by specifying the shape and particle size of the elastic powder rubber and modifying the surface of the elastic powder rubber with a specific modifier to obtain a large amount of the elastic powder rubber asphalt mixture. The purpose is to provide a recycling technology that can be mixed in.

[0007]

In order to solve the above-mentioned objects, the present inventors have modified the shape, particle size and surface of elastic powder rubber in order to improve the adhesion between the elastic powder rubber and asphalt. The present invention was solved by various studies on materials.

The present invention relates to a method for producing an elastic powder rubber aggregate mixed in an asphalt mixture, in which the elastic powder rubber and methyl methacrylate-natural rubber graftmer latex are mixed by stirring and heat-cured with light stirring to obtain elasticity. Method for producing elastic powder rubber aggregate for asphalt mixture in which surface of powder rubber is coated with methyl methacrylate-natural rubber graftmer

And elastic powder rubber modified by coating the surface of elastic powder rubber with methyl methacrylate-natural rubber graftmer and elastic powder modified by coating the surface of elastic powder rubber with methyl methacrylate-natural rubber graftmer It is an asphalt mixture mixed with rubber aggregate.

The present invention provides a method for producing an elastic powder rubber aggregate which is mixed in an asphalt mixture, and has a thickness of 0.5-5.
mm flakes (flat shape) elastic powder rubber having a particle size of 3 to 30 mm and methyl methacrylate-natural rubber graftmer latex are stirred and mixed, and heat-cured with light stirring to methacrylic rubber surface. Method for producing elastic powdered rubber aggregate for asphalt mixture coated with methyl acid-natural rubber grafter

And a thickness of 0.5 to 5 mm and a particle size of 3 to 3
Elastic powder rubber aggregate obtained by coating the surface of 0 mm flaky (flat) elastic powder rubber with methyl methacrylate-natural rubber graftmer and a thickness of 0.5 to 5
It is an asphalt mixture in which an elastic powder rubber aggregate modified by coating the surface of a flaky (flat) elastic powder rubber having a diameter of 3 mm and a particle diameter of 3 to 30 mm with methyl methacrylate-natural rubber graftmer is mixed.

The elastic powder rubber used in the present invention is manufactured by crushing tire peeling having a thickness of 5 mm or less and sheet-like (flake-like) waste rubber having a thickness of 5 mm or less. A flake shape having a thickness of 0.5 to 5 mm and a particle size of 3 to 30 mm is preferable. Further, when this elastic powder rubber is used, there is an effect that a small amount of asphalt is used and an asphalt mixture having high strength is obtained.

Methacrylic acid-natural rubber graftmer latex is used as a modifier for modifying the surface of the elastic powder rubber used in the present invention. The amount of the methyl methacrylate-natural rubber graftmer latex used is 3 to 15 parts by weight diluted with water so that the solid content concentration is 10 to 50% with respect to 100 parts by weight of the elastic powder rubber.

In the present invention, the thickness of 0.5 to 5 mm and the particle size of 3 to 30 mm are required for reuse by taking advantage of the tire tread characteristics such as wear resistance, durability, slip resistance, and water resistance.
The shape and particle size (large surface area) of the flaky (flat) elastic powder rubber retains the characteristics of the tire best, and also improves the adhesive force of the elastic powder rubber with asphalt. To this end, the surface of the elastic powder rubber can be coated with methyl methacrylate-natural rubber graftmer to increase the polarity and improve the adhesive strength.

After the elastic powder rubber of the present invention was replaced with the conventional aggregate to produce the asphalt mixture by the conventional working method, the mixture can be compacted by the conventional equipment and the same working procedure.

In order to specifically manufacture the elastic powder rubber aggregate of the present invention, 3 to 10 parts by weight of talc is added to 100 parts by weight of the elastic powder rubber, and mixed by stirring, and further 3 to 15 parts by weight of methacrylic acid. Methyl-natural rubber graftmer latex is diluted with water so as to have a solid content concentration of 10 to 50%, added, and mixed by stirring. When it is confirmed that the surface of the elastic powder rubber is completely wet, 130- An elastic powder rubber aggregate in which the surface of the elastic powder rubber is coated with methyl methacrylate-natural rubber graftmer by heating and curing with warm air of 150 ° C. for 30 to 10 minutes is prepared. An asphalt mixture containing elastic powder rubber was prepared by mixing -100%.

[0017]

[Function] Since the elastic powder rubber has low polarity, coating the surface with methyl methacrylate-natural rubber graftmer enhances the polarity to improve the adhesive strength with asphalt, the strength of the asphalt mixture and the compaction workability of the mixture. Improve.

[0018]

EXAMPLES The present invention will now be described in detail based on examples. (Example 1) 100 parts by weight of flaked elastic powder rubber having a thickness of 0.5 to 3 mm and a particle diameter of 3 to 15 mm from a tread rubber of a used tire and 3 parts by weight of talc were mixed,
8 parts by weight of Emultech 40 (methyl methacrylate-natural rubber graftmer latex, manufactured by Ito Shoji) and 1 part by weight of Longisu K25 (emulsifier, manufactured by Arakawa Hayashi Chemical Co., Ltd.) diluted with 10 parts by weight of water were added and mixed. An elastic powder rubber aggregate (A) whose surface was modified by heating and hardening at 130 ° C. for 30 minutes with light stirring was manufactured. In order to compare the adhesive force between the surface modified elastic powder rubber aggregate (A) and the untreated elastic powder rubber (B) asphalt, an asphalt mixture having the compounding ratio shown in Table 1 was prepared and subjected to a crush test method. As a result of comparing the adhesive strength from the crush strength and the deformation amount, it was proved that the elastic powder rubber aggregate with the modified surface is superior. It shows in Table 1.

[0019]

[Table 1]

(Embodiment 2) Elastic powder rubber (chip shape produced from used tires) having a diameter of 3 to 5 mm, 100 parts by weight and 3 parts by weight of talc were mixed, and further, Longisu K25
(Emulsifier, manufactured by Arakawa Hayashi Chemical Co., Ltd.) 1 part by weight, Emultech 4
8 parts by weight of 0 (methyl methacrylate-natural rubber graftmer latex, manufactured by Ito Shoji) was added with 8 parts by weight of water, and the mixture was stirred and mixed until the surface of the tire chip became wet, and 130 ° C × with gentle stirring. It was heat-cured for 30 minutes to produce a tire chip aggregate (C). Next, in order to compare the adhesive strength between the surface-modified elastic powder rubber aggregate (C) and the untreated elastic powder rubber (chips manufactured from used tires) (D) asphalt, the blending ratio in Table 1 Manufactured an asphalt mixture containing tire chip aggregates. The adhesive strength between the elastic powder rubber aggregate and the asphalt was examined by the crush test method. The crush strength and the amount of deformation shown in Table 1 were obtained.

(Embodiment 3) Elastic powder rubber whose surface is modified with a 5-10 mm crushed chip obtained by coarsely crushing waste rubber and selecting it with Emultech 40 Since there is almost no difference in the adhesive force of the aggregate (flake-like, chip-like, and hijiki-like) to the asphalt, they can be blended and used according to each application and required performance. It is also easy to manufacture crushed chips, flakes, chips, and hijiki in that order. Therefore, in terms of cost, it becomes cheaper in this order. The design can be considered in terms of cost.

(Example 4) 100 parts by weight of flaky elastic powder rubber of a used tire and 5 parts by weight of talc were mixed, and 10 parts by weight of Emultech 40 and 1 part by weight of Longisue K25 were mixed therein. Add, stir and mix thoroughly, and dry with a dryer in an asphalt mix plant 15
An elastic powder rubber aggregate for an asphalt mixture was manufactured by heating and curing at 0 ° C for 10 minutes. When an asphalt mixture was produced in the same blending ratio as in (Example 1) and the adhesive strength was confirmed by crushing strength, the strength was 4.0 Kgf / cm @ 2, the same as in (Example 1).

Example 5 100 parts by weight of 5 mm granular powder rubber (chip shape) produced from a used tire and 5 parts by weight of talc were mixed, 10 parts by weight of chloroprene LM-50 (Denka chloroprene latex) and Longisu K25.
1 part by weight is mixed, diluted with 5 parts by weight of water and added, well mixed, and then heat-cured at 150 ° C. for 10 minutes with light stirring to coat the tire chip surface (as in Example 2). After confirming the adhesive effect by crushing strength, 3.
The result was 6 kgf / cm @ 2, which was almost the same as in Example 2).

[0024]

The effect of the present invention is to use an elastic powder rubber produced from waste rubber in a specific shape, improve the surface of the elastic powder rubber with a specific modifier to improve the adhesive strength with asphalt,
With improved strength and workability, it will be used as aggregate for asphalt pavement, and will be reused in large quantities.
It can contribute to the conservation of the global environment as well as effective use of limited aggregate resources.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-48-19690 (JP, A) JP-A-56-122846 (JP, A) JP-A-48-8835 (JP, A) JP-A-58- 201822 (JP, A) JP 51-73085 (JP, A) JP 56-30481 (JP, A) JP 4-142381 (JP, A) JP 3-193412 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 21/00 C08L 51/04 C08L 95/00

Claims (3)

(57) [Claims] 1. A method for producing an elastic powder rubber aggregate mixed in an asphalt mixture, wherein the elastic powder rubber and methyl methacrylate-natural rubber graftmer latex are mixed by stirring and heat-cured while gently stirring to obtain elastic powder rubber. A method for producing an elastic powder rubber aggregate for an asphalt mixture, the surface of which is coated with a methyl methacrylate-natural rubber graftmer. 2. An elastic powder rubber aggregate obtained by coating the surface of an elastic powder rubber with methyl methacrylate-natural rubber graftmer to modify. 3. An asphalt mixture containing elastic powder rubber aggregate, which is obtained by coating the surface of elastic powder rubber with methyl methacrylate-natural rubber graftmer and modifying it.