JPS62225335A - Collapsible material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Benefits of production Ll))! The present invention is applicable to (1) Ith shock absorbing material for shoe soles of sports shoes such as jogging, tennis, and basketball shoes and various work shoes; (2) various sports materials such as helmets, supporter 1 torso pads, shin guards, shoulder bats, etc. Shock-absorbing materials commonly used in martial arts such as supplies or masks, translations, magic hands, shin guards, etc. (3) Shock-absorbing materials for construction, safety, and tli car helmets, (4) Industrial use! #7 This relates to a shock absorbing material suitable as a cooking acid absorbing component material.

Traditionally, sponges have been commonly used as shock absorbing materials, but in order to obtain the necessary shock absorption properties, sponges need to be made of thick material, and due to constraints such as the shape and weight of the product. When used in the above products, only unsatisfactory shock absorption performance was obtained.

Recently, sponges and the like with high shock absorption properties have been developed and become commercially available to meet such demands.

However, when these new materials are used for shoe soles, etc., they are effective during normal running, but their use is limited because they do not provide sufficient shock absorption when strong impact forces are applied, such as when jumping. Also, since it is a sponge, if it receives a strong impact, the bottoming effect will be significantly reduced. Moreover, it becomes permanently deformed after being used for a long time.

Chilled sowing also has drawbacks such as a hard feel.

Gel-like shock-absorbing materials are also known, but they are easily deformed by external forces, easily break when subjected to impact, and are highly adhesive.

Difficult to handle as waste.

In addition, it bottoms out when subjected to a large impact, has no impact absorption effect, limits its uses, has high fluidity, and has disadvantages such as significant permanent deformation of the material after long-term use.

In addition, unfoamed rubber and urethane-based shock absorbers are effective against strong impacts, but they are significantly heavier than sponges, which severely limits their uses.

In addition, air-filled cushions require sufficient thickness and volume to absorb large impacts, and have low responsiveness that takes time to absorb impacts, so air leak countermeasures and air replenishment mechanisms are required.

Problem to be Solved by the Invention An object of the present invention is to provide a material that is lightweight, has excellent shock absorbing properties against a wide range of impact forces, and has significantly improved permanent deformability during long-term use. With the goal.

The shock absorbing material according to the present invention has a rebound resilience of 2 μm at 20°C.
5% or less, density 0.05-0.9g/c? m3, S
A foam with a hardness of 50' or less according to RIS, a tensile strength of 100 Kg/cm2 or more, an elongation at break of 50% or more, a hardness (JIS A) of 60" or more, and a thickness of 10 to 200.
It is characterized by strongly bonding and laminating a synthetic resin film of 0 Bm and/or a molded product of the film having a large number of closed cells.

Examples of the above-mentioned foam include foamed rubber or urethane sponge, such as:
1001i parts of a polymer consisting of a butadiene copolymer or a styrene-butadiene copolymer and 40ffii% or less of other rubber components.

030 to 300 parts by weight of filler, 05-100 parts by weight of plasticizer.

(2) 0.5 to 601 parts of a blowing agent. A low resilience rubber foam obtained by adding a vulcanizing agent and a vulcanization accelerator to a mixture of the following and heating and foaming and curing is preferred.

If the impact resilience of such a foam at 20°C exceeds 25%, it will not be able to provide sufficient impact absorption properties as a shock absorbing material, and if the density exceeds 0.9 g/cm', the impact absorption properties of the foam will deteriorate. If the weight becomes heavy and the density is less than 0゜05g/cm', W
R impact absorption and strength will be insufficient.

The thickness of the foam layer is in the range 0.5mm-10mm.

If the thickness is less than 0.5 mm, it is difficult to load with ordinary foam, and if it is more than 10 mm, the impact improvement effect will be poor.

Tensile strength is 100Kg/cm2 or more, elongation at break is 5
0% or more, hardness (JISA) is 60' or more, thickness is 10
Examples of the synthetic resin film having a thickness of 2,000 lm include polyurethane-based, 1,2-polybutadiene-based, polyolefin-based, polyamide-based, and vinyl chloride-based synthetic resin films.

The tensile strength of these synthetic resin films is 100Kg/c
If the film thickness is less than m2 or the elongation at break is less than 50%, the strength of the film is insufficient and it is difficult to use it for various purposes as an f# impact absorbing material.If the film thickness is less than 10 JLm, it is easy to tear, and if it exceeds 2000 gm. If it is too thick, the film will not easily deform and will no longer provide an excellent source of shock absorption.

The lamination is a multilayer structure in which at least one layer of foam and at least one layer of synthetic resin film are laminated, and both surface layers of the laminated structure are films.

It can be a foam, and it can be a film on one side and a foam on the other side.

An example of the laminated structure will be explained with reference to FIGS. 1A, B, and C. In FIG. 1A, both surface layers of the laminated material are films 1, and the foam 2 is not exposed on the surface.

FIG. 1B shows the case where one side is the film 1 and the other side is the foam 2, and FIG. 1C shows the case where both surface layers are the foam 2 and the film 1 is not exposed on the surface.

A strong bond between the foam layer and the synthetic resin film layer can be easily obtained by heat fusion using a hot press or by applying a suitable adhesive to the synthetic resin film layer.

In addition to the above structure, in order to further enhance the impact absorption effect, at least one of the synthetic resin film layers of the above laminate is replaced with a molded layer of the synthetic resin film having a large number of closed cells. It's good to do that.

A molded article of the synthetic resin film having a large number of closed cells can be easily produced by, for example, forming the film into an uneven shape in advance and then bonding it onto a smooth film using heat fusion or adhesive. can get. The closed cells formed here have a diameter of 1 to 30 mm and a height of 1 to 10 mm. Outside this range, the impact improvement effect of the laminated material is not good, and the shape of each cell does not matter.

To explain this structure with reference to Fig. 2, Fig. 2 A shows a molded synthetic resin film in which both surface layers are films 1, which are laminated alternately with foam 2, and one of the film layers has a large number of closed cells. Indicates the case where the item is 11, and the second
In Figure B, both surface layers are foam 2, alternating with film l and vi
The figure shows a synthetic resin film molded product 11 in which one of the film layers has a large number of closed cells.

In addition, in unreleased IJ, 1.2 as a synthetic resin film
- When a thermoplastic synthetic resin film such as a polybutadiene film is used, it is extremely easy to heat-mold the laminate (shock absorbing material), which has the advantage of being able to be molded into a desired shape.

Examples 1 to 5 and Comparative Examples 1 to 2 Shock absorbing material samples having the base materials and structures shown in Table 1 were made, and the impact acceleration peak value (G) and compression set were measured and compared. The results are shown in the lower part of Table 1.

Table 1 Note that in Table 1, *l to *8 are as follows.

*l: A low-resilience rubber foam obtained by adding a vulcanizing agent and a vulcanization accelerator to the following mixture and curing it by heating.

Styrene-butadiene copolymer with styrene content of 60℃ tatami% 80 parts by weight natural rubber
20 Tamahakebe Alcium Carbonate 7
0ff1. ri 1 part clay 70 parts process oil 301c parts blowing agent
10 City 4A Section *2: Chloroprene foam *3: Measured with a Dunlop trypsometer (value at 20°C) *4: LORD Chemical Produc
Polyurethane film made by TS; trade name Tuften *5: 1.2-polybutadiene film made by JSR *6: 2 mm closed cells with a height of 2 to 3 mm and a diameter of 8 mm.
Polyurethane film formed to line up at intervals *7: Acceleration when a weight with a weight of 5 kg and a ground contact area of 9 cm2 is freely dropped *8: 2 kg/cm2 (constant load), permanent deformation after 24 hours (20 As is clear from Table 1, Examples 1 to 6 according to the present invention
The sample has a significantly lower impact acceleration peak value (G) when dropped from a high place and a lower compression set than the sample of Comparative Example 1, which is a foam alone.

Furthermore, the impact acceleration peak value (G) is lower than WJX compared to the sample of Comparative Example 2 in which a foam (chloroprene foam) with a rebound resilience higher than 25% and a synthetic resin film are bonded and laminated.

Effects of the invention 1) Shock absorption effect is improved compared to the case of foam alone.
■ Do it.

2) The impact absorption effect is greatly improved compared to a laminate of foam and film that does not meet the requirements stipulated in the present invention.

3) Maintains lightness.

4)9. Permanent deformability is greatly improved compared to the case of foam alone.

5) In the present invention, Table 2 shows the respective characteristics of a laminate made of only a foam and a synthetic resin film and a laminate including a film molded product having a large number of closed cells.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a laminated structure of a foam and a synthetic resin film, and FIG. 2 is a diagram showing an example of a laminated structure of a foam and a synthetic resin film. It is a figure which shows the example of a changed structure.

Claims (1)

[Claims] Impact resilience at 20℃ is 25% or less, density is 0.05
~0.9g/cm^3, foam with hardness of 50° or less by SRIS, tensile strength of 100Kg/cm^2 or more, elongation at break of 50% or more, hardness (JIS A) of 60
A shock absorbing material comprising a synthetic resin film having a thickness of 10 to 2000 μm and/or a molded product of the film having a large number of closed cells, which are firmly bonded and laminated.