JPH0985760A - Manufacture of elastic paving member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productive efficiency by shortening molding time at a stroke by a method wherein a specific mixture is filled in a vacant part of top and bottom tools, both tools are clamped, the mixture in the vacant part is molded and crosslinked by applying heated pressurized vapor directly to the mixture in the vacant part. SOLUTION: An elastic paving member is manufactured by a method wherein a mixture composed of a rubber chip and liquid polyurethane is filled in a vacant part 4 formed by combining a top tool 1 and a bottom tool 2, they are clamped, and the mixture in the vacant part 4 is molded and crosslinked by applying heated pressurized vapor directly thereto. Then, since the heated pressurized vapor is applied directly to the mixture thus, even when a volume of a product is increased, the pressurized vapor is sent to an inside through a void part of a molded product, and its molding time is shortened. Further, since liquid polyurethane is used as a binder, a crosslink accelerating effect owing to moisture is made great, a crosslinking speed is increased, and with both functions being combined, molding time is greatly shortened.

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 a concept in a narrow sense used only for pavements, but is a concept in a broad sense used not only for pavements but also for structures around pools, nursing homes, nurseries, and the like. To do.

[0002]

2. Description of the Related Art In the case of manufacturing a pavement member made of rubber chips, a method of mixing rubber chips and liquid polyurethane, filling the mixture into a mold, pressurizing, compressing and heating to cure and mold the liquid polyurethane Is taken. As a heating method, usually, 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 becomes larger, the heat conduction to the mixture becomes worse, and it takes a long time to complete the crosslinking of the liquid polyurethane inside the product. Therefore, the molding time was lengthened and the production efficiency was significantly reduced. The present invention provides a method for manufacturing an elastic pavement member that can shorten the molding time all at once and improve the production efficiency.

[0004]

The method for producing an elastic pavement member of the present invention is formed by combining a mixture of rubber chips and liquid polyurethane in an upper mold (1) and a lower mold (2). Filled in the hollow cavity (4) and clamped,
Next, the mixture in the cavity (4) is directly applied with heated and pressurized steam to be molded and crosslinked.

The heated and pressurized steam is supplied to the hollow portion (4).
In order to supply air to the inside, one or two of the upper mold (1) and the lower mold (2) both have a plurality of air supply holes (3) which communicate with the cavity (4) from the outside. ) Is provided and the steam heated and pressurized from the outside is sent.

As a method of supplying steam from the outside, the molds (1) and (2) are put into a vulcanizing can and the heated and pressurized steam is sent into the can to form the hollow cavity. Division (4)
A method is adopted in which steam is introduced through a plurality of air supply holes (3) leading to the. At this time, the air supply hole (3) is provided in the vertical direction and has an inner diameter of 2 to 5 mm, and if the air supply holes (3) are located at horizontal intervals of 20 to 30 mm, the rubber chip and the liquid polyurethane are The vapor is thoroughly fed into the cavity (4) of the mold filled with the mixture, and is sufficient to crosslink and cure the mixture.

Further, as a method of supplying steam from the outside, an endless air supply hole having a large inner diameter which makes one turn in the lateral direction is provided inside the mold, and the steam is communicated to the outside at two positions opposite to the air supply hole. An inlet hole and a steam outlet hole are provided, and an endless air inlet hole is provided with a large number of small air holes leading to the cavity of the mold.
A method of directly sending steam heated and pressurized from the steam inlet to the cavity of the mold is also adopted.

The rubber chips used in the present invention are made of waste vulcanized rubber produced in the production process of waste tires, vulcanized rubber products, recycled tires, etc., by a crusher such as a roll machine or a rotary blade type shredder. It is crushed, and the size of the rubber chip particles is preferably 3 to 8 mm. When rubber chips and liquid polyurethane are mixed and filled in the cavity (4) of the mold and molded, if the size of the particles of the rubber chips is 3 to 8 mm, the molded product 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-component curing type or a two-component curing type polyether polyurethane is used. Polyether-based polyurethane, so-called prepolymer is used,
Either a one-component curing type that has an isocyanate group at its end and is cured by moisture, or a two-component curing type that is cured by combining a curing agent such as polyol or polyamine can be used. Polyether polyurethane does not deteriorate in physical properties due to heat and humidity,
The property of the present invention is not deteriorated even when it is cross-linked by the heated and pressurized steam, the bonding between the rubber chips is strengthened, and the wear resistance is also good, so that it is most suitable as a binder of an elastic pavement member.

When the rubber chips and the liquid polyurethane are mixed, 5 to 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 kneading machine, a spiral mixer, a planetary mixer, a Hensiel mixer, or the like can be used.
When using a two-part curable 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, it is not necessary to color the liquid polyurethane, and no pigment is added.

After kneading, the mixture is filled in a cavity (4) of a mold, which is a combination of an upper mold (1) and a lower mold (2),
The upper mold and the lower mold are clamped with a clamp or the like, charged into a vulcanization can, and heated and pressurized steam is fed into the vulcanization can for molding and crosslinking. 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.
It is molded at 70 ° C. for 4 to 10 minutes.

[0012]

According to the method of manufacturing an elastic pavement member according to the present invention, a mixture of rubber chips and liquid polyurethane is
A large number of air supply holes (3) provided inside the mold by filling in the cavity (4) formed by combining the upper mold (1) and the lower mold (2) and clamping the mold. Since the heated and pressurized steam is directly applied, even when the volume of the product is increased, the pressurized steam is sent to the inside through the void portion of the molded product, so that the molding time is shortened.

Further, since liquid polyurethane is used as the binder, the effect of promoting cross-linking by water is great, and the cross-linking speed becomes faster than that during normal heating. The effects of the two are contaminated, and the molding time can be greatly shortened. Further, since the polyether polyurethane is used as the liquid polyurethane, there is no deterioration of physical properties due to moist heat during molding and after use of the product, and the bondability with the rubber chip is good. An excellent pavement member having durability can be provided.

[0014]

EXAMPLE A vulcanized rubber was crushed and 10 parts by weight of a one-part curable polyether urethane prepolymer having an isocyanate group at the end was added to 100 parts by weight of a rubber chip whose size was adjusted to 3 to 8 mm. After kneading with a spil mixer and uniformly coating the liquid urethane around the rubber chips, weigh a predetermined amount, fill the cavities (4) of the molds (1) and (2) shown in FIG. 2, and clamp (Fig. The upper mold (1) and the lower mold (2) were clamped with each other (not shown).

Next, the molds (1) and (2) thus clamped are put into a vulcanizing can, and the pressure in the can is 5 kgf / cm ² and the temperature is 150-150.
The elastic pavement member of the present invention was manufactured by feeding steam heated and pressurized to 160 ° C and performing molding and crosslinking for 5 minutes. Liquid polyurethane was completely crosslinked and hardened to the inside of the elastic pavement member, and the rubber chips were firmly bonded to each other, and the physical properties and appearance were good. The physical properties are as follows.

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

As a comparative example, a kneaded product of the rubber tip and liquid polyurethane is used in a mold (1) in which the cavity (4) has the same volume as the embodiment shown in FIG. 4 in which the air supply hole (3) is not provided. ), (2) are filled in the cavity (4) and carried into a heat press machine having a heating plate on the upper and lower surfaces,
It took 15 minutes for the liquid polyurethane to be completely crosslinked and cured by pressurizing and heating at ℃ and molding and crosslinking. It should be noted that the pressurizing / heating time was set to 7 minutes, 10 minutes, and 13 minutes, but in all cases, the liquid polyurethane was not cured inside.

[0018]

[Effects] According to the method for manufacturing an elastic pavement member according to the present invention, rubber chips and liquid polyurethane are mixed, filled in a mold, clamped, and heated / pressurized by the mixture in the cavity of the mold. Since steam is directly applied to form and crosslink, the elastic pavement member can be efficiently manufactured in a short time even if the volume thereof is large.

[Brief description of drawings]

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

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

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

4 is a vertical cross-sectional view taken along the line BB in FIG.

[Explanation 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 number Agency reference number FI Technical display location B29L 31:00

Claims (5)

[Claims] 1. A cavity (4) formed by combining a rubber chip and liquid polyurethane with an upper mold (1) and a lower mold (2) is filled and clamped. Then, a method for producing an elastic pavement member, which comprises directly applying heated and pressurized steam to the mixture in the hollow portion (4) to form and crosslink the mixture. 2. One or two of the molds (1), (2) are both provided with a plurality of air supply holes (3) communicating with the cavity (4) from the outside. The method for manufacturing an elastic pavement member according to claim 1, wherein 3. The method for manufacturing an elastic pavement member according to claim 2, wherein the air supply holes (3) are provided in a vertical direction. 4. A polyether type polyurethane is used as the liquid polyurethane.
~ A method for manufacturing an elastic pavement member, which is one of the 3 items. 5. The method for manufacturing an elastic pavement member according to claim 3, wherein the polyether polyurethane is a one-component curing type or a two-component curing type.