JP7045070B2 - Manufacturing method of rubber mat and rubber mat - Google Patents

Description

The present invention relates to a method for manufacturing a rubber mat and a rubber mat.

Rubber mats are used for various purposes. For example, a rubber mat is installed at the feet of a worker, and the rubber mat is used for the purpose of reducing the feeling of fatigue of the feet when the worker stands and works. In addition, rubber mats are installed under industrial machines and molds, and rubber mats are used for vibration isolation and floor curing.

For example, in Patent Document 1, rubber chips are mixed with unvulcanized natural rubber or synthetic rubber and kneaded, the kneaded product is packed in a molding die, and the kneaded product is vulcanized at a predetermined temperature while being compressed. Describes how to make a floor mat.

Further, Patent Document 2 describes a floor mat formed by immersing a rubber chip in a binder, filling it in a molding die, pressurizing it, and heating it. It is described that a urethane resin, an epoxy resin, or a vinyl chloride resin is used as the binder.

Japanese Unexamined Patent Publication No. 2002-153155 Japanese Patent Application Laid-Open No. 2002-051658

The floor mat of Patent Document 1 is provided with a plurality of columnar convex portions on the back surface. The floor mat of Patent Document 2 is provided with a plurality of V-shaped grooves on the back surface. In the floor mats of Patent Documents 1 and 2, a mold having a shape corresponding to a convex portion or a V-shaped groove is used to form a floor panel having the above-mentioned shape.

In the floor panel of Patent Document 1 or Patent Document 2, since a mold is used to obtain a desired shape, the dimensions of the floor panel that can be manufactured are limited. In addition, since a mold is used, it may not be possible to flexibly respond to changes in specifications such as the thickness and size of the floor panel. Further, there is a problem that maintenance of the mold is costly.

An object of the present invention is to provide a rubber mat having an uneven surface without using a mold and a method for manufacturing the same.

It is a method of kneading a plurality of rubber chips and uncrosslinked raw rubber, forming a kneaded product into a plate shape, cross-linking the plate-shaped molded product, and manufacturing a rubber mat in which the rubber chips are bonded with a rubber base material. In the manufactured rubber mat, the rubber chips are exposed on at least one of the front surface of the rubber base material and the back surface of the rubber base material, and at least one surface of the rubber base material is uneven depending on the outer shape of the rubber chips. The above-mentioned problem is solved by the manufacturing method of the rubber mat which is the one which has become.

Further, it is a rubber mat having a plurality of rubber chips and a rubber base material for binding the rubber chips, and the rubber chips are exposed on at least one of the front surface of the rubber base material and the back surface of the rubber base material, and the rubber is rubber. The above problem is solved by a rubber mat in which at least one surface of the base material is uneven due to the outer shape of the rubber chip.

In the above rubber mat and its manufacturing method, a plurality of rubber chips are exposed on at least one surface of the front surface of the rubber substrate and the back surface of the rubber substrate, and one surface of the rubber substrate depends on the outer shape of the rubber chip. It is uneven. Therefore, it is not necessary to use a mold to make the surface of the rubber mat uneven. Since a mold is not required for molding the rubber mat, it is possible to flexibly respond to changes in specifications such as the size and thickness of the rubber mat.

In the above manufacturing method, a step of passing a kneaded product of a plurality of rubber chips and uncrosslinked raw rubber through between molding rolls to form a plate, and a process of transporting the kneaded product formed into a plate. It is preferable to carry out the above two steps continuously, including a step of cross-linking. Since the above manufacturing method does not use a mold, it is possible to continuously manufacture a rubber mat by performing processing such as molding and cross-linking while transporting a kneaded product of rubber chips and uncrosslinked raw rubber.

In the above rubber mat and its manufacturing method, the rubber chips are exposed on both the front surface and the back surface of the rubber base material, and both the front surface and the back surface of the rubber base material are uneven due to the outer shape of the rubber chips. It is preferable to do so. By doing so, it is possible to use the rubber mat without distinguishing between the front surface and the back surface, and it is possible to manufacture the rubber mat without distinguishing between the front surface and the back surface in the manufacturing process.

According to the present invention, it is possible to provide a rubber mat having an uneven surface and a method for manufacturing the same without using a mold.

It is explanatory drawing which shows an example of the manufacturing method of a rubber mat. It is explanatory drawing which shows an example of the process of molding a rubber mat. It is sectional drawing which shows an example of a rubber mat.

Hereinafter, a method for producing a rubber mat of the present invention and a preferred embodiment of the rubber mat will be described.

The method for producing a rubber mat of the present invention includes a step of kneading a plurality of rubber chips and uncrosslinked raw rubber, a step of forming the kneaded product into a plate shape, and a step of crosslinking the plate-shaped molded product. In the rubber mat to be manufactured, a plurality of rubber chips are bonded to each other by a rubber base material, and the rubber chips are exposed on at least one of the front surface of the rubber base material and the back surface of the rubber base material. At least one surface of the rubber chip is uneven due to the outer shape of the rubber chip. In the present specification, the term raw rubber means natural rubber or synthetic rubber before cross-linking.

The rubber chip used may be a piece containing rubber. Examples of rubber chips include ethylene propylene diene rubber, ethylene propylene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, isoprene rubber, isobutylene / isoprene rubber, acrylonitrile butadiene rubber, nitrile rubber, silicone rubber, fluororubber, acrylic rubber, and urethane. Fragments containing synthetic rubber such as rubber, polysulfide rubber, chlorinated butyl rubber, or epichlorohydrin rubber can be used. Further, for example, a fragment containing natural rubber can be used. These strips are preferably crosslinked. As the rubber chip to be used, fine pieces obtained by crushing the waste material of the rubber product may be used. Examples of the waste material include used rubber products such as tires, tubes, and rubber pipes, and scraps generated during the production of rubber products. The scraps generated when manufacturing rubber products include, for example, the ends generated when cutting a rubber hose to a predetermined length, the scraps generated by deburring after molding with a mold, or the mold. Examples include rubber scraps filled in the runner.

As the uncrosslinked raw rubber, a rubber whose elastic limit is increased by the cross-linking reaction and which functions as a binder for connecting the rubber chips can be used. Examples of the uncrosslinked raw rubber include ethylene propylene diene rubber, ethylene propylene rubber, acrylonitrile butadiene rubber, isoprene rubber, acrylic rubber, synthetic rubber such as silicone rubber, and natural rubber. As the cross-linking agent (vulcanizing agent), for example, sulfur, peroxide, metal oxide or the like generally used as a cross-linking agent can be used.

In the step of kneading the rubber chip and the uncrosslinked raw rubber, the raw rubber and the rubber chip may be mixed and kneaded by a known method. For example, it can be kneaded using a kneader such as a Banbury mixer, an open roll, or a kneader. When kneading the raw rubber and the rubber chips, it is preferable to add a cross-linking agent and knead them. At this time, other additives such as an antiaging agent, a filler, a pigment, or a vulcanization accelerator may be added.

In the step of forming the kneaded product into a plate shape, it is sufficient that the kneaded product obtained by kneading the rubber chip and the uncrosslinked raw rubber can be formed into a plate shape in which the unevenness due to the outer shape of the rubber chip remains. Is not particularly limited. For example, as shown in FIG. 1, the kneaded product 11 can be passed between the forming rolls 51 to form a plate. In the example of FIG. 1, a conveyor 52 configured as an endless track and capable of transporting the kneaded material 11 is passed between the pair of forming rolls 51. When the kneaded material 11 is placed on the conveyor 52, the kneaded material 11 is conveyed by the conveyor 52, and the kneaded material 11 sandwiched between the pair of forming rolls 51 is formed into a plate shape.

In the example of FIG. 1, an example using a pair of forming rolls and a conveyor 52 is shown, but as shown in FIG. 2, the conveyor may be omitted. In the example of FIG. 2, it is possible to obtain a plate-shaped molded product by passing the kneaded product 11 between a pair of molding rolls 51 facing each other at predetermined intervals.

The size of the gap between the molding rolls is not particularly limited, but is preferably 1 to 16 mm, for example, according to the thickness of the rubber base material of the rubber mat to be manufactured.

When an open roll is used as the kneading machine, an uncrosslinked kneaded product wound around the roll can be unwound to obtain a substantially plate-shaped kneaded product. It can also be molded into a plate shape by cutting off unnecessary parts such as edges.

The step of cross-linking the plate-shaped molded product is not particularly limited as long as it cross-links the polymer contained in the raw rubber. For example, the cross-linking reaction may be caused by heating the raw rubber to which the cross-linking agent is added, or the cross-linking reaction may be caused by irradiating the raw rubber to which the cross-linking agent is added with ultraviolet rays, electron beams or the like. The cross-linking reaction is convenient and preferable to be carried out by heating. For example, in the example of FIG. 1, the kneaded product 11 which is passed between a pair of forming rolls 51 and formed into a plate shape is conveyed by a conveyor 52, charged into a heating furnace 53, and conveyed by the conveyor 52 while being conveyed in the heating furnace. The raw rubber is crosslinked by heating in 53.

When the polymer contained in the raw rubber is crosslinked, as shown in FIG. 3, the rubber chip 12 is exposed on at least one of the front surface of the rubber base material 13 and the back surface of the rubber base material 13, and the rubber base material is exposed. A rubber mat 1 having at least one surface of 13 having an uneven shape due to the outer shape of the rubber chip 12 can be obtained. Since at least one of the front surface and the back surface of the rubber mat 1 is uneven, the rubber mat is less likely to slip or lift even when used in a damp place. In the example of FIG. 3, the rubber chip 12 is in a state where a part or the whole thereof is embedded in the rubber base material 13. On the front surface or the back surface of the rubber base material 13, a part of the rubber chip 12 is embedded in the rubber base material 13, and the rubber mat 1 is uneven due to the outer shape of the rubber base material 12.

In the example of FIG. 3, since both the front surface and the back surface of the rubber mat 1 are uneven, the rubber mat 1 can be used without being conscious of the difference between the front surface and the back surface. Further, even when manufacturing the rubber mat, it is possible to manufacture the rubber mat 1 without distinguishing between the front and back sides.

In the above method for manufacturing a rubber mat, a mold is not required when manufacturing a rubber mat having at least one of the front surface and the back surface having an uneven shape. Therefore, when manufacturing a long rubber mat or the like, there are no restrictions on the mold. Further, since the mold is not used for manufacturing the rubber mat, the cost required for the maintenance of the mold can be cut.

The thickness of the rubber base material constituting the rubber mat is not particularly limited, but is preferably 1 mm or more, preferably 2.8 mm or more, and preferably 4.5 mm or more. The thickness of the rubber mat is preferably 16 mm or less. By setting the thickness of the rubber base material in the above range, it is possible to prevent the rubber chips from being crushed when the rubber mat is formed into a plate shape, and it is possible to prevent the rubber chips from falling off from the rubber base material. ..

The particle size of the rubber chip is not particularly limited, but for example, the range of the particle size distribution can be 1.0 to 10.0 mm. If the particle size of the rubber chip is within the above range, an uneven rubber mat having good drainage performance can be obtained. Further, if the particle size of the rubber chip is within the above range, the rubber chip is less likely to fall off from the rubber base material and the yield is improved.

The particle size distribution of rubber chips ranges from the minimum particle size to the maximum particle size. It is preferable to divide the thickness (mm) of the rubber base material by the maximum particle size (mm) of the rubber chips so that the ratio (%) obtained by multiplying by 100 is 320% or less. Specifically, the ratio is obtained by the following [Equation 1]. The lower limit of the ratio is not particularly limited, but is preferably 15% or more, for example.
[Equation 1]
Ratio (%) = Maximum particle size of rubber chip (mm) ÷ Thickness of rubber base material (mm) x 100

The amount of the rubber chips to be blended with respect to the raw rubber is not particularly limited, but for example, 5 to 45 parts by weight of the rubber chips can be blended with respect to 100 parts by weight of the raw rubber. When the blending amount of the rubber chips is set as described above, the rubber chips are less likely to fall off from the rubber base material, the yield is improved, and an uneven rubber mat having good drainage performance can be obtained. In the rubber mat produced by the method of the present embodiment, the blending amount of the rubber chips becomes the content of the rubber chips as it is. Therefore, it is preferable that the rubber mat contains 5 to 45 parts by weight of the rubber chip with respect to 100 parts by weight of the rubber.

In the example of FIG. 1, a step of passing a kneaded product of a plurality of rubber chips and uncrosslinked raw rubber through between molding rolls to form a plate shape, and while transporting the kneaded product formed into a plate shape. The two steps are continuously performed, including a step of cross-linking. The step of forming the kneaded product into a plate shape and the step of cross-linking the kneaded product are not continuous and may be performed separately. For example, uncrosslinked raw rubber kneaded using a kneader such as an open roll and a plurality of rubber chips are molded into a plate shape, and the plate-shaped molded rubber is carried to a heating device such as a heating furnace for a cross-linking reaction. May be done.

Hereinafter, a specific description will be given with reference to examples.

The rubber chips were classified using a sieve having an opening of 8 mm, 5 mm and 3 mm. As a result, rubber chips having a maximum particle size of 8 mm, 5 mm, and 3 mm were obtained, respectively. To be precise, the maximum particle size is less than 8 mm, less than 5 mm, and less than 3 mm, but they are equated with 8 mm, 5 mm, and 3 mm, respectively. All rubber chips are composed of vulcanized EPDM.

[Test 1]
A rubber chip having a maximum particle size of 8 mm was kneaded with unvulcanized EPDM and sulfur as a vulcanizing agent, and the kneaded product was passed between the molding rolls shown in FIG. 2 to form a plate. Each plate-shaped molded product was heated in a heating furnace and vulcanized to produce a rubber mat. In the production of the rubber mat, the thickness of the rubber base material was made different as shown in Table 1 below by adjusting the spacing between the molding rolls.

Table 1 shows the results of visual inspection of the shape of the manufactured rubber mat. The "ratio (%)" in Table 1 is obtained by the above formula 1. The "sheet thickness" in Table 1 is the thickness (mm) of the rubber base material.

[Test 2]
A rubber chip having a maximum particle size of 5 mm was kneaded with unvulcanized EPDM and sulfur as a vulcanizing agent, and the kneaded product was passed between the molding rolls shown in FIG. 2 to form a plate. Each plate-shaped molded product was heated in a heating furnace and vulcanized to produce a rubber mat. In the production of the rubber mat, the thickness of the rubber base material was made different as shown in Table 1 below by adjusting the spacing between the molding rolls.

Table 1 shows the results of visual inspection of the shape of the manufactured rubber mat. The "ratio (%)" in Table 2 is obtained by the above formula 1.

[Test 3]
A rubber chip having a maximum particle size of 3 mm was kneaded with unvulcanized EPDM and sulfur as a vulcanizing agent, and the kneaded product was passed between the molding rolls shown in FIG. 2 to form a plate. Each plate-shaped molded product was heated in a heating furnace and vulcanized to produce a rubber mat. In the production of the rubber mat, the thickness of the rubber base material was made different as shown in Table 1 below by adjusting the spacing between the molding rolls.

Table 1 shows the results of visual inspection of the shape of the manufactured rubber mat. The "ratio (%)" in Table 2 is obtained by the above formula 1.

As shown in Tables 1 to 3, it can be seen that crushing of the rubber chips is prevented by setting the ratio determined by the above formula 1 to 320% or less.

1 Rubber mat 11 Kneaded material 12 Rubber chip 13 Rubber base material 51 Molding roll 52 Conveyor 53 Heating furnace

Claims (4)

Knead multiple rubber chips and uncrosslinked raw rubber,
Form the kneaded material into a plate and
Crosslink the plate-shaped molded product and
It is a method of manufacturing a rubber mat in which multiple rubber chips are bonded with a rubber base material without using a mold.
The blending amount of the plurality of rubber chips is 5 to 45 parts by weight with respect to 100 parts by weight of the raw rubber.
The plurality of rubber chips have a shape in which the ratio obtained by dividing the thickness of the rubber base material by the maximum particle size of the rubber chips and multiplying by 100 is 320% or less.
In the manufactured rubber mat, the rubber chip is exposed on at least one surface of the front surface of the rubber substrate and the back surface of the rubber substrate, and at least one surface of the rubber substrate is formed by the outer shape of the rubber chip. A method for manufacturing a rubber mat that has an uneven shape. A step of passing a kneaded product of the plurality of rubber chips and the uncrosslinked raw rubber between molding rolls while transporting the rubber chips to form a plate.
Including the step of cross-linking while transporting the kneaded product formed into a plate shape.
The method for manufacturing a rubber mat according to claim 1, wherein the two steps are continuously performed. A rubber mat having a plurality of rubber chips and a rubber base material for binding the rubber chips.
The rubber base material is a portion excluding the rubber chip, and is a crosslinked raw rubber.
The rubber chip is exposed on at least one of the front surface of the rubber base material and the back surface of the rubber base material, and one surface of the rubber base material is uneven due to the outer shape of the rubber base material.
The plurality of rubber chips have a shape in which the ratio obtained by dividing the thickness of the rubber base material by the maximum particle size of the rubber chips and multiplying by 100 is 320% or less.
The content of the plurality of rubber chips is 5 to 45 parts by weight with respect to 100 parts by weight of the rubber base material. The third aspect of claim 3, wherein the rubber chip is exposed on both the front surface and the back surface of the rubber base material, and both the front surface and the back surface of the rubber base material are uneven due to the outer shape of the rubber chip. Rubber mat.

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