JPH0358283B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method of vulcanizing rubber into which a fiberboard is inserted.

(Prior Art) Generally, methods for reinforcing rubber mats include reinforcing the outer skin of the rubber or inserting a reinforcing material inside the rubber to increase the strength of the rubber mat.

(Problem to be solved by the invention) However, if a reinforcing board made of acrylic resin or polypropylene is buried inside a rubber mat and pressure and temperature are applied to vulcanize the rubber,
Due to the temperature, gas is generated from the fiber board, and moisture contained in the fiber board evaporates, causing the volume to expand, causing the rubber mat to swell.

This kind of expansion does not occur when high pressure is applied for vulcanization, but when vulcanization is finished and the pressure is lowered, the volume rapidly expands due to this pressure drop, causing the fiber board and rubber to expand. There were problems in that the fiberboard itself would peel off and the fiberboard itself would decompose due to rapid expansion.

For this reason, in the past, it was not possible to maintain the design dimensions due to the above-mentioned separation between the fiber board and the rubber mat, deformation of the fiber board, or destruction, etc. Therefore, it was extremely difficult and difficult to commercialize such reinforced boards. Ta.

(Means for Solving the Problems) Therefore, in the present invention, in view of the above, the fiber board is subjected to preliminary treatment consisting of pressurization and heat treatment in advance to remove gas and moisture, and the fiber board is In this method, degassing holes are formed and degassing is performed by repeating pressurization and depressurization at predetermined intervals even during vulcanization, thereby preventing peeling or deformation.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

First, the fiber board 2 will be explained. This is a press board made of acrylic resin, FRP, or the like.

Next, the vulcanization method will be explained. First, in this example, the fiber board 2 is pretreated before the vulcanization treatment. This is done by placing the fiber board 2 on a vulcanizing press (not shown), heating the upper and lower molds for this press to approximately 160°C to heat the fiber board 2, and using the press machine to heat the fiber board 2. ^The pressure ^{applied to}
is simply called Kg. ) is designed to repeat pressurization and depressurization.

To explain this specifically, first 10
Pressurize for about 10 minutes at a pressure of Kg. After 10 minutes, reduce the pressure to 10 kg to 1 kg over 30 seconds. Then, when the pressure is reduced to 1Kg, it suddenly increases to 10
Pressurize to Kg.

The above process is repeated three times in this example as a preliminary process, as shown in FIG. 1A.

This preliminary treatment allows moisture absorbed by the fiber board 2 and gas generated from the fiber board by heating to escape.

Note that the reason why the pressure is increased and decreased repeatedly in the above process is that this makes it easier for gas to escape. However, if the pressure is reduced rapidly, the gas whose volume has been reduced due to the high pressure will expand rapidly and destroy the fibers of the fiber board 2, so in this example, the pressure is reduced over approximately 30 seconds. It's getting old.

After the above preliminary treatment is completed, the fiber board 2 is taken out from the press, and the convex portions 3 for degassing are formed on the fiber board 2. This is formed by cutting off a part of the fiberboard 2 by machine or manually. In this example, the degassing convex portion 3 is formed at only one location on the fiber board 2, but it goes without saying that it may be formed at multiple locations if necessary.

Next, the fiber board 2 that has undergone such processing is
Two sheets are stacked one on top of the other, and a spacer 4 formed in the shape of a rectangular cylinder is attached to the convex portion 3 for degassing.
This is because when the fiber board 2 is sandwiched from the top and bottom as shown in FIG.
This is to prevent the rubber mat main body 1 from blocking the rubber mat body 1. However, if the gas venting protrusion 3 is sufficiently communicated with the outside when sandwiched between the rubber mat main bodies 1, it is not necessary to install the spacer 4.

After the above-mentioned work is completed, vulcanization treatment is performed next. This vulcanization process consists of preheating A and main vulcanization B in this example, as shown in FIG. 1B. In this vulcanization process, as shown in FIG. 2, the rubber mat main body 1 before vulcanization is first placed on the lower mold of the press, and the two-ply fiber board 2 on which the spacer 4 is attached is placed on top of the rubber mat main body 1 before vulcanization. The rubber mat main body 1 before vulcanization is placed on top of the rubber mat main body 1, and the upper die of the press is lowered to start pressurizing and heating.

First, in preheating A, as shown in Figure 1,
A temperature of ~160° C. is applied to the rubber mat main body 1 and the fiber board 2 from the mold of a press machine, and at the same time, pressurization with a pressure of 150 kg is started. This 150Kg pressurization was continued for about 3 minutes,
At the end of 3 minutes, the pressure is rapidly reduced to 10 kg.

Next, the pressure is gradually reduced from this 10Kg to 0.5Kg over 30 seconds, and when the pressure is reduced to 0.5Kg, the pressure is rapidly increased again to 10Kg, and this is repeated three times. This completes the preheating A.

This preheating A has the meaning of completely removing gas and moisture contained in the fiber board 2 and hardening the fiber board 2. (When the fiber board 2 is heated, the molecules of the fiber board 2 are crosslinked and hardened.) On the other hand, for moisture and gas, the pressure is decreased from 150Kg to 10Kg, and the pressure is increased to 10Kg and 0.5Kg, and the pressure is reduced repeatedly. Most can be removed by This gas is then released to the outside through a small gap formed between the resins of the gas venting convex portions 3.

In particular, in this example, since the fiber boards 2 are stacked in two layers, a gap is formed between the stacked surfaces, and this gap makes it easier for gas, moisture, etc. to escape to the outside. There is.

Next, after the above-mentioned process is completed, main vulcanization B is started. In this main vulcanization, the pressure is immediately increased to 150 kg after the above-mentioned preheating A is completed, and this pressure is maintained for about 10 minutes. During the 10 minutes that this pressure and heat are applied, the rubber molecules are crosslinked and the rubber hardens to a predetermined strength. (Naturally, the rubber begins to harden in the preheating A mentioned above, but only a slight hardening occurs in the preheating A.) Next, pressurize at 150 kg for 10 minutes, then rapidly increase the pressure to 10 kg. decrease to. Then, the pressure is further reduced from this 10 kg to 0.5 kg over about 30 seconds.
Then, when the pressure drops to 0.5Kg, it suddenly increases to 10
The pressure is returned to Kg, and thereafter the pressure is increased and reduced three times at this pressure of 10 Kg and 0.5 Kg, and finally the pressure is removed to complete the vulcanization process.

Due to the above-described treatment, the rubber mat 5 is free from warping, curling, etc., and can obtain a good desired shape.

In addition, in the above embodiment, the case where two fiber boards 3 are stacked has been explained, but this is also possible if one or three fiber boards are stacked.
Of course, the number may be more than one sheet. Furthermore, if the rubber mat requires greater flexibility, the fiber board 3 may be divided into a plurality of pieces in advance. Furthermore, a convex portion 3 for degassing
may be formed in advance before the pretreatment.

Next, make a hole 2 with a diameter of about 5 mm on the fiber board 2.
FIG. 4 shows an embodiment in which a plurality of a are provided. In the case of this embodiment, the hole 2a is formed in advance and the rubber mat body 1 is inserted between the rubber mats and the vulcanization process is performed. As shown in FIGS. 5 and 7, the upper surface The rubber mat main body 1 and the lower rubber mat main body 1 are bonded together, and a good adhesion effect can be obtained. In this embodiment, the degassing convex portions 3 are formed at two locations on the left and right sides of the fiber board 2 in the drawing.

Next, an embodiment in which this example is applied to a mat switch will be described based on FIG. In this example,
Two rubber mats 5 formed by the vulcanization process in the above embodiment are stacked one on top of the other, and a frame-shaped joint 1a is formed at the end of the rubber mat 5, and a switch is provided between the rubber mats 5. A space 6 is formed for this purpose. Projections 7 are formed integrally with the rubber mat 5 on the upper and lower surfaces of the space 6 as shown in the figure, respectively, to maintain a distance between them.

Next, on the upper and lower surfaces of the space 6 in the drawing, a plurality of electrodes 8 and 9 for configuring a switch are attached in parallel at predetermined intervals, respectively. The electrodes 8 and 9 are made of flat braided wire, and are attached so as to be perpendicular to each other.

On the other hand, a plurality of convex anti-slip portions 1b are formed on the upper and lower surfaces of the mat switch 10 shown in FIG. This anti-slip 1b is used not only to prevent slipping but also to easily absorb the pressure applied when a metal piece or the like falls in directions other than the vertical direction shown in the figure. In addition, this anti-slip 1
The shape b may be formed in the shape of an independent protrusion, or may be formed in a plurality of stripes in parallel or in the vertical and horizontal directions.

In this embodiment, since the rubber mat 5 is flexible, it can withstand shock pressure from the outside, and even if a metal piece with a sharp end falls, it will not be inserted into the interior. fiber board 2
has sufficient strength to withstand these shearing forces, so the outer skin may be torn and the internal electrodes 8 and 9 may be damaged, or water or oil may enter the electrodes 8 and 9. There is no possibility of corrosion or short circuits.

(Effects of the Invention) In other words, in the present invention, even if the rubber mat is vulcanized with the fiber board inserted inside, by the method described in the claims, the pressure of gas and water vapor emitted by the fiber board will not be applied. Therefore, the present invention has an excellent feature that the rubber mat main body and the fiber board will not separate from each other, the fiber board will not warp, and furthermore, the fiber board itself will not be destroyed due to the generation of gas. be.

For this reason, it is possible to easily make a rubber mat reinforced with fiberboard in this way, so when this example is applied to a mat switch, for example, it can be used as a consumable item that often breaks down. It also has the desirable feature of being highly reliable and durable.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1A is a diagram showing pretreatment in this embodiment, and FIG. 1B shows preheating A and main vulcanization B in this embodiment. Fig. 2 is a perspective view showing how the rubber mat main body and the fiber board are stacked, Fig. 3 is a perspective view showing the state where the fiber board is sandwiched inside the rubber mat main body, and Fig. 4 is a perspective view showing how the fiber board 2 is stacked. FIG. 5 is a plan view showing an embodiment in which a hole 2a is formed in contrast to the hole 2a in FIG.
6 is a sectional view taken along line C-C in FIG. 4, FIG. 7 is a sectional view taken along line B-B in FIG. FIG. 1... Rubber mat main body, 2... Fiber board, 3
...Protrusion for degassing, 4...Spacer, 5...
Rubber mat, 6...Space, 7...Protrusion, 8,
9... Electrode, 10... Matsuto switch.

Claims (1)

[Claims] 1. A method of vulcanizing rubber for a rubber mat having a reinforcing fiber board inside, comprising: Pressurize the fiber board with a pressure of 1 to 10 kg/cm ² for 0.5 to 10 minutes using the mold and lower mold.
After the pressurization time has elapsed, during the period of 10 to 60 seconds,
Preliminary treatment is performed to reduce the pressure from 10 Kg/cm ² to 0.1 to 0.5 Kg/cm ² . (b) Repeat the above preliminary treatment 1 to 5 times. (c) Next, at least one protrusion for gas venting is formed at the end of the board. (d) Next, this board is sandwiched from above and below by the rubber mat main body before vulcanization and set in the mold. (e) Next, after applying a temperature of 130 to 200° C. and a pressure of 140 to 160 Kg/cm ² for about 1 to 5 minutes, the pressure of the press is reduced to 5 to 10 Kg/cm ² . (F) From the above pressure of 5 to 10 Kg/cm ² , the pressure is further lowered to 0.1 to 0.5 Kg/cm ² over 10 to 60 seconds, and then returned to the pressure of 5 to 10 Kg/cm ² . (g) Repeat the above process (f) 1 to 5 times. (H) Next, the pressure of the press is increased again to 140 to 160 Kg/cm ² , this state is maintained for 6 to 15 minutes, and then this pressure is lowered to 5 to 10 Kg/cm ² . (li) From the above pressure of 5 to 10 Kg/cm ² , the pressure is further lowered to 0.1 to 0.5 Kg/cm ² over 10 to 60 seconds, and then returned to the pressure of 5 to 10 Kg/cm ² . (j) Repeat the above process (li) 1 to 5 times. characterized by consisting of the above processes (a) to (n),
A method of vulcanizing rubber with fiberboard inside. 2. The vulcanization method according to claim 1, wherein the fiber board is divided into a plurality of pieces. 3. The vulcanization method according to claim 1, wherein the degassing convex portion is formed in advance. 4. The vulcanization method according to claim 1, characterized in that a cylindrical spacer is attached to the gas venting convex portion. 5. The vulcanization method according to claim 1, wherein a plurality of the fiber boards are stacked and inserted into the rubber mat.