JPS5855177B2 - Compression sensitive adhesive foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a compression-sensitive adhesive foam or a tape made of the same, which does not substantially adhere to the application surface without pressure, but firmly adheres to the application surface when strongly compressed.

It provides similar products processed into shapes such as sheets and rods.

As will be clear from the following description, the compression-sensitive adhesive foam of the present invention or its analogues has a foam tissue and an adhesive tissue that are substantially integrated, and only the adhesive tissue is exposed orally or under pressure. Designed to prevent separation.

Therefore, it is clearly distinguished from a type in which a pre-formed foam is impregnated with an adhesive substance, in which the foam structure and the adhesive substance are not substantially integrated, that is, the two separate by mouth or under pressure. .

Self-adhesive materials that adhere to the surface to which they are applied by compressing a foam are known (for example, Japanese Patent Laid-Open No. 54-58
No. 734).

This material is then applied to or impregnated with adhesive under pressure on the foam.

Therefore, the purpose of providing a compression-sensitive adhesive foam (or its analogue) in the present invention is to simultaneously foam the material constituting the foam tissue and the material constituting the adhesive tissue, and to The aim is to make the surface substantially non- or weakly adhesive, ie to the extent that the foam can move relatively freely over the application surface.

This purpose is to provide a foamed product obtained by heating and foaming vulcanization of a mixture molded product containing a rubber, a softener, a filler, a blowing agent, an adhesion-imparting resin, and a vulcanizing agent.
They are distantly related because they contain 3 to 15 parts by weight of solid paraffin, or 3 to 15 parts by weight of the solid paraffin and fatty acid in total.

The compression-sensitive adhesive foam of the present invention comprises an ethylene-propylene copolymer rubber having excellent heat resistance, oil resistance, weather resistance, etc.
Rubbers such as butyl rubber and styrene-butyl diene rubber (
(some amount of natural rubber may be added) per 100 parts by weight, a softening agent that is viscous and compatible with the rubber used, such as polybutene, liquid paraffin, low molecular weight polyisobutylene, liquid rubber, process oil, etc. 30 to 350 parts by weight of a filler that is uniformly dispersed and/or compatible with the rubber used, such as clay curk, carbon, silica, calcium carbonate, etc., a blowing agent such as para-toluene sulfonyl hydra. Sheen, azidicarbonamide, para-toluene sulfonyl hydrazide,
Nitroso, pentamethylene, tetramine, etc. 3 to 30
By weight, water repellency, adhesive properties, and adhesion-imparting resins that are compatible with the rubbers used, such as terpene resins, petroleum-based resins, and coumaron resins. 200 parts by weight or less, further vulcanizing agents such as sulfur, zinc white, paraquinone dioxime, etc., vulcanization accelerators such as dibenzothiazyl disulfide (DM), tetramethylthuram disulfide, zinc dimethyl dithiocarbamate, etc. Zinc diethyl dithiocarbamate, etc., colorants such as titanium yellow, titanium white, cobalt green,
Cerulean blue or the like may be added as desired.

The mixture consisting of these components contains 100% rubber.
Based on the weight part, 3 to 15 parts by weight of solid paraffin or both the solid paraffin and a fatty acid such as stearic acid are added in a total amount of 3 to 15 parts by weight (the fatty acid is preferably 7 parts by weight or less), and the tape, It is formed into sheets or rods, and then heated and foamed and vulcanized.

The foam of the present invention, which is formed by integrally vulcanizing and foaming a mixed system of rubber, other components, solid paraffin, or solid paraffin and fatty acid, has an adhesive structure, that is, a softening agent and adhesive properties contained in the foam. The imparting resin is formed integrally with the foam structure, and solid paraffin or a mixture having a non-adhesive function is present in the form of a continuous or discontinuous thin film on the surface of these structures, so that the surface of the foam or its cut surface is is considered non-adhesive or weakly adhesive.

When the foam is compressed, the adhesive structure causes plastic flow as the foam structure deforms, gathers on the surface, and firmly adheres to the application surface.

Therefore, if the amount of the solid paraffin is less than 3 parts by weight, good non- or weak adhesiveness cannot be obtained, and if it is more than 15 parts by weight, sufficient adhesive strength cannot be obtained after compression, which is not preferable.

The compression-sensitive adhesive foam of the present invention is obtained by foaming and vulcanizing the rubber and other components in a single process, and has substantially no or weak adhesion in the normal state, and can be bonded by compression. Because it is a material, it adapts well to finely uneven surfaces or surfaces to which non-planar structures are applied, and the foams can be bonded and integrated by simply butting or overlapping and compressing them, and are completely waterproof. A suitable connection can be obtained.

The present invention will be specifically described below using examples.

The words "part of the text" indicate parts by weight.

EXAMPLE A compression-sensitive adhesive foam according to the invention is obtained using the formulation A below in the following manner.

Method For each compound, first, the rubber is sufficiently stirred using a pressure kneader, and then the adhesion-imparting resin is added and further stirred.

Next, fillers, oils, etc. are added and mixed, and this is
After cooling to 0°C, a vulcanizing agent, a vulcanization accelerator, and a foaming agent are added to make a mixture, extruded into a sheet with a thickness of 4Tt7rL using an extruder, and heated at 150°C for 30 minutes to foam. Vulcanization yields a compression-sensitive adhesive foam with a thickness of between 15 and 15 cm.

Although this foam was slightly sticky to the hand, it did not adhere to the application object against its own weight in an uncompressed state.

Blend (4) Ethylene-propylene-diene copolymer rubber 100 (parts) Petroleum resin 100 Calcium carbonate 200 Process oil 50 Zinc white 5 Sulfur 1 Powdered paraffin 10 Stearic acid 1. Table 1 is obtained from the above formulation A. This figure shows the properties of the compression-sensitive adhesive foam sheet.

In Table 1, the 90 degree peel adhesive strength of the sample (20
mmX 200w7m) on a stainless steel plate,
After compressing for 10 hours under a load of o kg/= (compression rate 90%), the sample was compressed against a stainless steel plate at 9
Determined by peeling at an angle of 0 degrees (peeling speed 300 m)
m/min).

In addition, the clear adhesion strength is the sample (20mm x 20mm)
was sandwiched between two steel plates and compressed for 24 hours under a load of 100 kg/- (compression ratio 95%), then one steel plate was
It was obtained by pulling at a speed of 0mrryin.

Claims (1)

[Claims] 1. In a foamed product obtained by heating, foaming and vulcanizing a mixture molded product containing a rubber, a softener, a filler, a blowing agent, an adhesion-imparting resin, and a vulcanizing agent, the molded product contains 100 parts by weight of the rubber. A compression-sensitive adhesive foam that exhibits adhesive properties upon compression, characterized in that 3 to 15 parts by weight of solid paraffin, or 3 to 15 parts by weight of both the solid paraffin and fatty acid in total are blended. body.