JP2745043B2 - Method for manufacturing elastic pavement member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an elastic pavement member suitable for road construction. In the present invention, the pavement member is not limited to the narrow sense used only for the pavement, and is used in the broad sense used for structures such as pools, nursing homes, and nursery schools as well as the pavement. I do.

[0002]

2. Description of the Related Art When manufacturing a pavement member made of rubber chips, a method of mixing rubber chips and liquid polyurethane, filling the mixture into a mold, pressing, compressing and heating to cure and mold the liquid polyurethane. Is adopted. As a heating method, a method is usually adopted in which a mold is put between hot plates of a hot press machine and the mold is indirectly heated by heat sources of upper and lower heating plates.

[0003]

However, as the volume of the product to be molded increases, the conduction of heat to the mixture becomes worse, and it takes a longer time for the crosslinking of the liquid polyurethane to be completed inside the product. Therefore, the molding time was prolonged, and the production efficiency was remarkably reduced. The present invention provides a method of manufacturing an elastic pavement member capable of shortening the molding time at once and improving the production efficiency.

[0004]

According to the present invention, there is provided a method of manufacturing an elastic member, comprising forming a mixture comprising a rubber chip and a liquid polyurethane in an upper mold (1) and a lower mold (2). Filled into the cavity (4) to be
Next, the steam heated and pressurized into the mixture in the cavity (4) is supplied to the upper mold (1) and the upper mold (1) which communicate with the cavity (4) from outside.
And / or molded and cross-linked by directly contacting it from an air supply hole (3) provided in a lower mold (2) .

[0005] The heated and pressurized steam is transferred to the cavity (4).
The upper mold (1) and / or lower mold
In (2), a method is adopted in which a plurality of air supply holes (3) are provided from the outside to the cavity (4), and steam heated and pressurized from the outside is supplied.

[0006] As a method of supplying steam from the outside, the molds (1) and (2) are put in a vulcanizing can and the heated and pressurized steam is fed into the can. Department (4)
A method is adopted in which steam is introduced from a plurality of air holes (3) leading to the air. At this time, the air supply holes (3) are provided in the vertical direction, the inner diameter is 2 to 5 mm, and the positions of the air supply holes (3) are 20 to 30 mm apart from each other in the horizontal direction. The steam is thoroughly fed into the mold cavity (4) filled with the mixture, and is sufficient for crosslinking and curing the mixture.

As a method for supplying steam from the outside, an endless air supply hole having a large inner diameter and extending in the horizontal direction is provided in the inside of the mold, and the steam supply passage to the outside is provided at two locations opposed to the air supply hole. An inlet and a steam delivery hole are provided, and an endless air supply hole is provided with many small-diameter air supply holes communicating with the mold cavity.
A method is also employed in which steam heated and pressurized directly from the steam inlet is fed into the mold cavity.

The rubber chips used in the present invention are made from waste vulcanized rubber produced in the production process of waste tires, vulcanized rubber products, reclaimed tires and the like, and are milled by a mill such as a roll machine or a rotary blade type shredder. It is a pulverized material, and the particle size of the rubber chip is suitably 3 to 8 mm in diameter. When the rubber chip and the liquid polyurethane are mixed, filled into the mold cavity (4) and molded, if the particle size of the rubber chip is 3 to 8 mm, the molded article has an appropriate porosity, Reaches the inside of the molded product, and the crosslinking time is shortened. The shape of the rubber chip is not particularly limited.

In the present invention, a one-part curing type or two-part curing type polyether polyurethane is used. For polyether-based polyurethane, a so-called prepolymer is used,
Any of a one-pack curing type having an isocyanate group at the terminal and curing by moisture, and a two-pack curing type curing by combining a curing agent such as polyol or polyamine can be used. Polyether-based polyurethane does not have physical property deterioration due to wet heat,
Even when crosslinked by the heated and pressurized steam of the present invention, there is no decrease in physical properties, the bonding between the rubber chips is strengthened, and the abrasion resistance is good.

When mixing the rubber chips and the liquid polyurethane, 5-35 parts by weight of the liquid polyurethane is added to 100 parts by weight of the rubber chips, and the liquid polyurethane is mixed by a kneader so as to coat the rubber chips uniformly. As the kneader, a spiral mixer, a planetary mixer, a Hensiel mixer, or the like can be used.
When a two-component curing type is used for the liquid polyurethane, a curing agent such as polyamine is added to 100 parts by weight of the liquid polyurethane.
10 parts by weight are added. Rubber chips are used to prevent discoloration.
Since color chips are used, there is no need to color the liquid polyurethane and no pigment is added.

After kneading, the mixture is filled in a mold cavity (4) which is a combination of an upper mold (1) and a lower mold (2).
The upper mold and the lower mold are clamped by a clamp or the like, put into a vulcanization can, and heated and pressurized steam is fed into the vulcanization can to be molded and crosslinked. The molding conditions vary depending on the volume of the molded product, but the vapor pressure is 4-8 kgf / cm ² and the heating temperature is 150-1.
Molded at 70 ° C. for 4 to 10 minutes.

[0012]

According to the method for producing an elastic pavement member of the present invention, a mixture comprising a rubber chip and a liquid polyurethane is prepared by:
A large number of air holes (3) are filled in the cavity (4) formed by combining the upper mold (1) and the lower mold (2), clamped, and provided inside the mold. Since the heated and pressurized steam is directly applied, even if the volume of the product becomes large, the pressurized steam is sent to the inside through the voids of the molded product, thereby shortening the molding time.

Further, since liquid polyurethane is used as the binder, the effect of promoting cross-linking by water is large, and the speed of cross-linking is higher than in normal heating. Due to the dust and dust, the molding time can be greatly reduced. In addition, since the liquid polyurethane uses a polyether-based polyurethane, there is no deterioration in physical properties due to wet heat during molding or after use of the product, and the bonding property with the rubber chip is good. An excellent pavement member having durability can be provided.

[0014]

EXAMPLE A vulcanized rubber was pulverized, and 100 parts by weight of a rubber chip adjusted to a size of 3 to 8 mm was added with 10 parts by weight of a one-part curable polyether-based urethane prepolymer having an isocyanate group at a terminal. After kneading with a spile mixer, the liquid urethane is uniformly coated around the rubber chips, a predetermined amount is weighed, and the molds (1) and (2) shown in FIG. (Not shown), the upper mold (1) and the lower mold (2) were clamped.

Next, the clamped molds (1) and (2) are put into a vulcanizing can, and the inside of the can is heated at a pressure of 5 kgf / cm ² and a temperature of 150 to 150 kg / cm ^2.
Steam heated and pressurized to 160 ° C. was fed in to form and crosslink in 5 minutes to produce the elastic pavement member of the present invention. In this elastic pavement member, the liquid polyurethane was completely crosslinked and cured to the inside, and the rubber chips were firmly bonded to each other, so that both physical properties and appearance were good. The physical properties were as follows.

Tensile strength (MPa) 2.4 Elongation (%) according to JIS K6301 210 硬 Hardness (JIS-A) 60 滑 り Slip resistance Rubber bottom Dry 1.09 Rubber bottom Wet 0.98 using OY Pull Slip Meter 〃 Pu bottom Dry 0.68 〃 Pu bottom Wet 0.62 〃 Wet heat deterioration 360Hev (equivalent to 10 years) No abnormality Constant temperature and humidity machine (75 ℃ × 95%) Weather resistance 600Hev No abnormality Weather meter tester Wear resistance ( cc / Hp-Hr) 58.5 William wear tester JIS-K6264

As a comparative example, the mold obtained by kneading the rubber chips and the liquid polyurethane is the same as the embodiment shown in FIG. ) And (2), and are carried into a hot press machine having a hot plate on the upper and lower surfaces.
When the mixture was pressurized and heated at a temperature of ° C. and crosslinked by molding, it took 15 minutes for the liquid polyurethane to be completely crosslinked and cured. The pressurization / heating time was set at 7, 10 and 13 minutes, but none of the liquid polyurethanes was cured inside.

[0018]

According to the method of manufacturing an elastic pavement member according to the present invention, a rubber chip and liquid polyurethane are mixed, filled in a mold, clamped, and heated and pressurized to the mixture in the mold cavity. Since molding and crosslinking are performed by directly applying steam, even if the volume of the elastic pavement member is large, it can be efficiently manufactured in a short time.

[Brief description of the drawings]

FIG. 1 is a plan view of a mold according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along the line AA in FIG.

FIG. 3 is a plan view of a mold of a comparative example.

FIG. 4 is a longitudinal sectional view taken along the line BB in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper mold 2 Lower mold 3 Air supply hole 4 Mold cavity

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 75:00 105: 16 B29L 31:00

Claims (5)

(57) [Claims] An air gap (4) formed by combining a mixture of rubber chips and liquid polyurethane with an upper mold (1) and a lower mold (2) is filled and clamped. Then , an upper mold for passing steam heated and pressurized to the mixture in the cavity (4) from the outside to the cavity (4).
(1) and / or an air supply hole provided in the lower mold (2)
(3) A method for producing an elastic pavement member, which is more directly applied and crosslinked. 2. The air supply hole (3) includes an upper mold (1) and an upper mold (1).
The method according to claim 1 , wherein a plurality of the lower molds (2) are provided. 3. The method for manufacturing an elastic pavement member according to claim 2, wherein said air supply holes (3) are provided in a vertical direction. 4. The liquid polyurethane according to claim 1, wherein a polyether polyurethane is used.
4. A method for manufacturing an elastic pavement member according to any one of the above-mentioned items. 5. The method according to claim 1, wherein the polyether polyurethane is a one-part curing type or a two-part curing type.
5. The method for producing an elastic pavement member according to 4 .