JPS6013636Y2 - heat recoverable articles - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a heat-recoverable article in which a crosslinked rubber as a heat-shrinkable material and an elastic body are combined as at least two layers, in particular,
The present invention relates to an article useful as a sealing material that increases its outer diameter or wall thickness by heat shrinkage.

Focusing on the heat-shrinkability of plastic materials, various products have been proposed that shrink when heated. It must be thick enough to be easily attached to the sealed part of the article to be sealed, that is, it must have high heat recovery ability, be securely attached, and be stable even during storage when not in use. etc. were required.

The present invention has been devised in view of these points.

The purpose is to obtain a heat-recoverable article having a large heat-recovery force L1 and large elasticity.

The present invention is characterized by a combination of at least two layers of crosslinked rubber as a heat-shrinkable material, such as crosslinked trans-isoprene rubber, and an elastic body, which are stretched and fixed in the overall length direction, so that the length can be shortened by heating. The outer diameter or wall thickness is increased, and it can be attached to the sealing part of the article to be sealed.

In addition, by selecting various elastic materials, properties such as electrical insulation, weather resistance against oxygen, light, or ozone, chemical resistance against solvents, tear strength, or abrasion resistance can be imparted to the heat-recoverable article. It provides appropriate rigidity during storage when not in use, and can protect the crosslinked rubber in its stretched state.

As the crosslinked rubber used in the present invention, natural rubber, neoprene rubber, etc. are used, and crosslinked trans-isoprene rubber is particularly preferred.

For example, Kuraray trans polyisoprene rubber TP-30
1 (manufactured by Clarei Soprene Chemical ■).

This polyisoprene has good processability, particularly low acetone extractability and fast crystallization rate.

Therefore, when used as a heat-shrinkable material, it is a synthetic product that has a slower crystallization rate than general natural rubber, and can be stretched and formed in a short time.

Furthermore, this material can be stretched by a factor of four or more (stretching rate of 400% or more), making it possible to obtain articles with great heat recovery ability.

It also has a low ash content and good heat aging resistance, making it ideal for outdoor use.

High hardness and durability. It also has less bad odor and is favorable for work.

As the elastic material, for example, ordinary natural rubber, ethylene propylene rubber, chlorosulfonated polyethylene rubber (trade name: Hypalon), chloroprenecomb, etc. may be used.

Hereinafter, embodiments of the present invention will be explained in more detail with reference to the drawings.

Figures 1 to 3 show an embodiment of the heat-recoverable article of the present invention, which has a cylindrical rod shape as a whole, 1 is a crosslinked rubber as the inner heat-shrinkable material, and 2 is an elastic body coated on the outer periphery. It is.

The crosslinked rubber 1 is made of transpolyisoprene, which has an extremely high heat recovery ability as described above, and is made by blending, for example, carbon carbide, a vulcanizing agent, a vulcanization accelerator, etc. with this polyisoprene.

Neoprene rubber is used as the elastic body.

The specific manufacturing process is not particularly limited, but for example, a crosslinked comb and an elastic body are molded by extrusion, etc., and then crosslinked (vulcanized) at the same time, and further 400% in the length direction.
It is stretched at the above stretching rate, and then rapidly cooled and fixed.

Furthermore, an elastic body may be stretched and then covered and fixed to the stretched crosslinked rubber.

Then, as shown in FIG.
A heat recoverable article having a length of 11 and an outer diameter is obtained.

When the heat-recoverable article thus obtained is heated, the crosslinked rubber 1 significantly shortens in the length direction as shown in FIG.
The length becomes 1°, and the outer diameter increases significantly to become the outer diameter.

At this time, the elastic body 2 also attaches to the crosslinked rubber 1 by the amount of stretching and contracts together.

Therefore, this heat-recoverable article is useful when used as a sealing material 3, for example, as shown in FIG.

In this case, for example, a pre-heat-shrinkable article smaller than the inner diameter of the steel pipe 4, which is outdoors and needs to be prevented from entering, is inserted into the opening as the sealing material 3, and then heated. This is the case when the tube is contracted and the outer diameter is increased thereby to tightly fit it into the sealing part of the opening of the steel pipe.

At this time, since the heat recovery power of the crosslinked rubber 1 is extremely large,
Great mounting strength can be obtained.

At this time, the elastic body 2 presses into the edge of the tube opening, allowing for even tighter attachment, and at the same time, its various properties protect the internal crosslinked rubber 1 and prevent damage. do.

In addition, in the case of the article of this example, it is a case of two layers inside and outside, but
The structure is not limited to this, and may have two or more layers, or may be combined with the elastic body on the inside.

Furthermore, it is also possible to form a sleeve by mechanically perforating holes in the inner crosslinked rubber in the longitudinal direction.

Figures 4 and 5 show other embodiments of the heat-recoverable article of the present invention, which are entirely sheet-shaped, with reference numeral 5 an elastic body located inside, and 6, 6 a heat-shrinkable article sandwiched between the upper and lower parts. It is a cross-linked rubber.

This structure prevents the sheet from curling or waving.

As the cross-linked rubber 6.6 and the elastic body 5, transpolyisoprene or neoprene rubber, which has a significantly high heat recovery power similar to the above-mentioned embodiments, is used.

The specific manufacturing method is not particularly limited, but for example, a crosslinked rubber elastic body is simultaneously extruded to form a composite structure, or an elastic film is bonded to a crosslinked rubber sheet and molded, and then crosslinked (processed) at the same time. sulfur), and then the whole is stretched in the length direction at an elongation rate of 400% or more, and then rapidly cooled and fixed.

Then, as shown in FIG. 4, a heat-recoverable article having a length of 13 and a wall thickness of d3 is obtained which is thinly stretched in the longitudinal direction and maintains this state permanently at a relatively low temperature such as room temperature.

Furthermore, an elastic body may be stretched and fixed to the stretched and fixed crosslinked rubber.

When the heat-recoverable article thus obtained is heated, the cross-linked rubber 6.6 significantly shortens in the length direction to a length of 14, as shown in Figure 5, and the wall thickness increases accordingly. Then, the wall thickness becomes d.

At this time, the elastic body 5 also attaches to the crosslinked rubber 6.6 and contracts together.

Therefore, this heat-recoverable article is useful, for example, when used as a sealant to fill gaps between certain articles.

That is, a pre-heat-shrinked article that is thinner than the interval of the gap to be sealed is placed as a sealing material into the gap between the articles to be sealed,
After that, it may be heated to cause thermal contraction, and the resulting increase in wall thickness may be used to tightly fit the device within the gap.

At this time, since the heat recovery power of the crosslinked rubber 6.6 is extremely large, a large mounting strength can be obtained.

The function of the elastic body 5 at this time is the same as in the above embodiment.

In the case of the article of this embodiment, the article is a sandwich-like three-layered article, but the article is not limited to this, and may have two layers or four or more layers.

The combination may also be in the form of a sandwich with the elastic body on the outside.

As explained above, the heat recovery article of the present invention has a composite structure in which at least two layers of a crosslinked rubber having a large heat recovery force and an elastic body are combined, and the crosslinked rubber has been subjected to a large elongation in the length direction. Because it is stretched and fixed at a certain rate,
For example, when used as a sealing material, the length is significantly shortened and the outer diameter or wall thickness is increased by heating, so that it can be easily and firmly attached to the sealing part of the article to be sealed simply by heating.

At this time, the elastic body also contracts together and presses against the inner surface of the sealing portion, allowing for even tighter attachment.

Furthermore, by selecting various combinations of the crosslinked rubber and the elastic body, a synergistic effect between the crosslinked rubber and the elastic body can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state of a heat-recoverable article according to an embodiment of the present invention before being stretched and heat-shrinked, and FIG. 2 is a perspective view showing a state of the same heat-recoverable article after heat-shrinking. , FIG. 3 is a perspective view showing the case where the above heat-recoverable article is applied to a sealing material,
FIG. 4 is a perspective view showing a stretched state of a heat-recoverable article according to another embodiment of the present invention before heat shrinkage, and FIG. 5 is a perspective view showing a state of the same heat-recoverable article after heat shrinkage. It is a diagram. 1.5...Heat-shrinkable crosslinked rubber, 2,6.6.
...Elastic body, 3... Sealing material.

Claims (3)

[Scope of utility model registration request] (1) A heat-recoverable material comprising at least two layers of heat-shrinkable cross-linked rubber and an elastic body, and the whole being stretched and fixed in the length direction. (2) The heat recovery article according to claim 1, which is a registered utility model, characterized in that the crosslinked rubber is cylindrical, and the outer periphery of the crosslinked rubber is coated with the elastic body to form two layers. (3) The heat recovery property according to claim 1 of the utility model registration claim, characterized in that the crosslinked rubber and the elastic body are both in the form of a sheet, and the elastic body is formed into a sandwich-like three-layer structure with the elastic body inside. Goods.