JPS5984961A - Adhesive - Google Patents

Abstract

PURPOSE:To provide an adhesive having high adhesive strength and applicable even to a vertical wall without sagging, by adding tiny hollow particles to an adhesive. CONSTITUTION:The objective adhesive is prepared by adding preferably 5-70% of tiny hollow particles (preferably silica balloon having average particle diameter of 5-200mu) to an adhesive based on e.g. epoxy resin, urea resin, melamine resin, phenolic resin, vinyl acetate resin, acrylic emulsion, hot-melt, natural rubber, chloroprene, SBR, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to adhesives, particularly adhesives with high adhesive strength.

In recent years, with the remarkable development of polymer chemistry, various adhesives have been developed that can easily and strongly bond not only the same type of adhesive but also different types of adhesives to each other.

Most of these adhesives are made of organic polymer materials,
The thickness of the adhesive layer is approximately 100 microns at most in order to exhibit maximum strength, and the adhesive strength is developed at the interface between the adhesive layer and the material to be adhered.

This is because the organic polymer material itself that is the material of the adhesive is generally not very strong, and for example, as seen in rubber adhesives such as nitrile rubber, the Ni adhesive is not thick enough. Then, the adhesive itself exhibits rubber-like elasticity, which is typified by the tearing phenomenon of the adhesive layer itself in response to strong force.

On the other hand, it is also known that additives such as charcoal are added to the adhesive X4 made of these organic polymeric materials. However, although most adhesives have the role of completely preventing volume shrinkage, the so-called fading phenomenon that occurs when fillers and adhesives harden, they do not substantially improve the adhesive strength of adhesives. Not only does it not play a role in this, but it also has disadvantages such as the apparent specific gravity of the adhesive, which causes sagging noise when applied to a vertical surface, and a marked increase in viscosity, making it difficult to apply. ing.

The present inventor has conducted various studies with the aim of solving the various drawbacks that these conventional adhesives had.

After some consideration, we found that if adhesive 1 itself could be fully strengthened, it would be possible to almost double or even exceed the adhesive strength that conventional adhesives had, without having to change the composition of the adhesive itself. Is it possible to make it false? I found it. Thus, the present invention provides an entire adhesive comprising fine hollow particles mixed into the adhesive.

In the present invention, the adhesive completely mixed with microscopic hollow spheres appears to have a large number of bubbles, which indicates its strength. Although this increase is surprising, it is believed that the amount of adhesive resin per volume can be reduced to provide lower shrinkage, and the internal stress can be reduced, thereby increasing the strength.

Adhesives used in the present invention include, for example, epoxy resin, area resin, melamine resin, phenol resin, vinyl acetate resin, acrylic emulsion, hot melt, natural comb, chloroprene, SBR, etc. It can be adopted as appropriate.

In addition, as the micro hollow particles, an appropriate material can be used, but
Inorganic materials are generally preferred because they do not interact with the adhesive and interfere with the adhesive effect or the effective properties of the adhesive itself.

Furthermore, even if such inorganic materials are used, grains that have not been vitrified by heating and drying are better than those that have become so-called glass by being melted. Microhollow bodies having the same structure are more suitable for use in the present invention.

The reason for this is not necessarily clear, but the adhesive itself partially penetrates and assimilates into the grain of the hollow body, so that the adhesive and the hollow body are sufficiently integrated (-and the grain of the hollow body itself also). This seems to be because the strength is increased and the overall strength of the adhesive layer is effectively enhanced.

As the inorganic material constituting such a hollow body, for example, silica, silicate powder, borosilicate glass, alumina, silica-alumina, etc. can be appropriately adopted, but among these, a siliceous hollow body has a particularly high reinforcing effect. preferable.

In addition, the average particle size of the micro hollow bodies is generally about 5 to 200μ7.
It is preferable to adopt C. If it deviates from the above range, it is not preferable because there is a risk that an effective reinforcing effect cannot be obtained.

It is generally appropriate that the mixing ratio of the adhesive and these micro hollow bodies is 5 to 70 volume-i% of the latter.

If the mixing ratio deviates from the above range, there is a risk that an effective reinforcing effect may not be obtained or that the adhesive effect may be completely inhibited, which is not preferable.

Note that there are no particular limitations on the method for producing the micro hollow bodies used in the present invention. For example, taking silica-based micro hollow bodies as an example, an aqueous solution containing sodium silicate and a blowing agent is used, This can be obtained by applying a dryer to form micro hollow bodies and further heating if necessary.Next, all embodiments of the present invention will be explained.

Example 1 Epoxy resin adhesive (manufactured by Homedain Co., Ltd., trade name: Epoxy $1500) 10 F, curing agent: 10 F, average particle size of 65 μm, silica roof CPQ, trade name (Q-Cell, made by Co., Ltd.) 4 f The gold was thoroughly mixed to obtain an adhesive composition having a Qf of 0.58. Adhesion area 6. +1' before such adhesion.
2 +) C, J 2. (The thickness of the iron adherend is 4
00μ 1, adhesion to similar adherend k R'1
Tsuda.

At this time, the adhesive was dried and solidified at room temperature for 10 hours.

The adhesive strength of the thus obtained adhesive was J Engineering S-1c6.
From 850 and J-K 5854, the tensile shear force, peeling, and peeling strength were measured using the strength measurement method, and the tensile shear force ij: 120Ay/l:dl
s Peeling force is 1t, z5kg/cJ, peeling force 5
It turned into L5.

For comparison, the tensile shear force, peel strength, and peel strength of the bonded body bonded in the same manner as in the above example except that no silica balloon was added were 60 #/cfl+7.5 h.
lct4. 35 k, which is understood to be significantly lower than the strength of the adhesive of the present invention.

Example 2 An adhesive composition with a specific gravity of 0.76 was obtained by mixing 10 f of an epoxy resin adhesive (manufactured by Cemedine Co., Ltd., trade name Ko Hoxina 1500) and 102 of a curing agent with the entirety of Silica Balu 729 with an average particle size of 75 μm. Ta. This was applied as in Example 1 and the adhesive strength was measured. The tensile shearing force was 90 h/lri, the peeling force was 9 h/d, and the peeling was 7.
It was a zero rejection.

In addition, the strength when silica ball is not added is tensile shearing force of 6 ohAvl and peeling force of 7.5 h.
/d, and the peeling was 35 glue, which shows the improvement in adhesive strength of the present invention.

Example 3 100 parts of epoxy acrylate adhesive (manufactured by Showa Kobunshi Co., Ltd., trade name: DEBOXY 802), 1 part of curing agent (manufactured by NOF Corporation, trade name: Permec), accelerator (copal naphthenoate)
) and 920 parts of silica balloons with an average particle size of 65 μm (PQ, manufactured by Co., Ltd., trade name Q, -cell) were sufficiently mixed to obtain an adhesive composition. Coated as in Example 1, 40
℃.

The adhesive was completely dried and solidified for 8 hours.

When the strength was measured as in Example 1, the tensile shear force was 8
0 Av/d, and the peeling strength was 16:5 h/ca.

For comparison, the tensile shearing force of an adhesive bonded under the same conditions except without the addition of silica balloons was 35 h/crll.
The 1-pull-off strength was 9 ky/cJ, and the effect of the present invention can be understood.

Claims (1)

[Claims] 1. An adhesive containing microscopic hollow particles. 2. The adhesive according to claim (1), wherein the micro hollow particles have an average particle size of 5 to 200μ. 3. Claim (1) that the micro hollow particles are inorganic.
Or (2) adhesive. 4. The adhesive according to claim (1) or (2), wherein the micro hollow particles are silica balloons. 5. The adhesive according to claim 1, wherein the amount of the micro hollow particles mixed is 5 to 70 volumes. 6. Adhesive: The composition of the adhesive is epoxy resin, urea resin, melamine resin, phenol resin, vinyl acetate resin, acrylic emulsion, hot melt, natural rubber, chloropre/SBR, or SBR. Adhesive according to claim (1).