JPS58168674A - Adhesive composition for spraying - Google Patents

Abstract

PURPOSE:To provide the titled adhesive compsn. which can be applied evenly and quickly over the surface of adherend, prepared by dissolving alpha-cyanoacrylate type adhesive in liquefied carbonic acid gas and storing the solution under pressure. CONSTITUTION:alpha-Cyanoacrylate is filled in a pressure container in an amount to obtain a desired blend ratio. Then liquefied carbonic acid gas is filled in it in an amount required for obtaining a predetermined blend ratio until a pressure corresponding to the blend ratio necessary for maintenance of a liquid state, is reached. Thus the container is filled with alpha-cyanoacrylate and liquefied carbonic acid gas which remains in a liquid state even at normal temperature. As the filled container is shaken, alpha-cyanoacrylate is diffused in liquefied carbonic acid gas and is dissolved homogeneously to form an adhesive compsn. for spraying with a desired blend ratio. The carbonic acid gas is incombustible, does no environmental harm, has no danger of fire and explosion and is safe as solvent for spray type adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an α-cyanoarylate adhesive composition for nine injections, which enables a uniform increase in wK and rapid increase in Km on the surface of an adherend.

α-Cyanoarylate adhesives do not require heating, pressure, catalysts, etc., and can be quickly anionized/adhesive by a trace amount of moisture contained in the atmosphere or a trace amount of O moisture around the adherend.
- rapidly #! in a short period of seconds or minutes! It has excellent rounding and indirect layering properties, and is widely used in industry as an instant adhesive. For example, rubber, plastics, and metals.

Since it can bond most materials such as ceramics, textiles, and leather, it is used in everything from the manufacture of electrical appliances and machines to the bonding of skin in surgical operations. However, as mentioned above, the α-cyanoacrylate adhesive has an extremely suitable curing speed, but it is difficult to apply it thinly and uniformly when bonding a wide surface. For this reason, when gluing a wide area, it is usually necessary to
Shear □It is a method of dropping an appropriate amount of noacrylate adhesive to make droplets and then bonding them together, but incomplete adhesion may occur due to uneven application. This has the disadvantage of not only staining the adhesive surface but also wasteful use and being uneconomical.

To solve this problem, α-cyanoacrylate is dissolved in an organic solvent, and this is sprayed onto the adhesive surface using a spray gun using a pressure source such as compressed air. A method has been proposed in which the adhesive is mixed with a propellant such as -11 and R-1 to form an aerosol and sprayed, and an attempt was made to apply α-cyanoacrylate adhesive evenly and evenly to a large surface. ing.

However, among the above-mentioned spraying methods, in the method of dissolving α-cyanoacrylate in an organic solvent, the organic solvent used must (support) lack of compatibility, (P) be stable, and f→adhesive effect. (2) have volatility; (e) have low toxicity;
(f) Methyl isobutyl kent was selected based on conditions such as being inexpensive, and a suitable solvent is methyl isobutyl kent.
n-Butyl acetate, trichloroethylene, tetratJI ethane, pentachloroethane, etc. have been proposed. Although these 0m steels were selected based on the conditions (a) to (f) above, they have the following drawbacks. In other words, (1) It is less toxic but not non-toxic, so use it as an injection! ! &
(i+) The above solvent is required to be volatile and is flammable, so there is a risk of fire, explosion, etc.
, 01D The above organic solvent melts and corrodes rubber and plastic, so it cannot be used to bond such materials. (ψ Compressed gas is required for spraying, so an attached device is required. -Things.

M Spraying with compressed gas has many disadvantages, such as the fact that the solvent particles are coarse and more α-cyanoacrylate than necessary is discharged, and that it is particularly difficult to use for thin coatings.

On the other hand, the method of using the spray 11 in an aerosol state by mixing it with a propellant such as Freon (R-11, R-12) has the following disadvantages. That is, Freon (R-11, R-
12) is not expensive, it is rounded and the pressure in the liquid state at room temperature is several 11/jli degrees. It also prevents excessive application. And 111 more 7W! Its use has disadvantages such as having a negative effect on human skin.

The present invention has been made based on the above-mentioned current situation, conducted various studies to solve the above-mentioned disadvantages, and found that liquefied carbon dioxide dissolves α-cyanoacrylate extremely well, and based on this new knowledge. , an adhesive composition for spraying, characterized in that α-cyanoacrylate is dissolved in pressurized liquefied carbon dioxide at a desired concentration so as to maintain a liquid state at room temperature and stored in a pressure-resistant container. . Liquefied carbon dioxide is generally 4Q at room temperature 9, for example 6C-25C.
To sand is a colorless, odorless liquid that is maintained in a liquid state under pressures of Kl/ajab to 66 KII/sl ILb.When this is expanded to atmospheric pressure and injected, it becomes extremely fine powdery snow. Furthermore, it is well known that powdery carbon dioxide gas is not liquefied at room temperature but is immediately vaporized by the sublimation phenomenon, dissipating as carbon dioxide gas, and is non-toxic and non-flammable. In terms of environmental hygiene, it is harmless and safe, with no risk of fire or explosion.

Based on this, the present inventors dissolved α-cyanoacrylate, an adhesive, in the liquefied carbon dioxide gas mentioned above, and found that the compatibility between them was extremely high. is α- to liquefied carbon dioxide under the ZSC temperature.
Cyanoacrylate is layered at various heating ratios (weight -) and the pressure (-/- gauge) of the heated solution is shown in Figure 94. The weight of the cyanoacrylate is 116% by weight, and the O temperature ratio is 62-/- gauge to keep these in a liquid state, and the liquefied acid gas is 60% heavy, and the α-cyanoacrylate is 40%.
The weight was 60-/- gauge, and it can be seen that as the heating ratio of α-cyanoacrylate increases, the pressure gradually decreases.

The adhesive can be produced as follows by dissolving α-cyanoacrylate in the above-mentioned liquefied carbon dioxide gas at a desired mixing ratio. First, the weight of α-cyanoacrylate required to achieve the desired heating ratio is injected into a pressure-resistant container (BO/B), and then 9 weight of liquefied carbon dioxide is added according to the desired mixing ratio. Fill the container until the pressure reaches the temperature corresponding to the rounding heating ratio that maintains the liquid state.

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As a result, the container is filled with α-cyanoacrylate and liquefied carbon dioxide gas, which remains liquid even at room temperature.Next, when these are filled with α-cyanoacrylate and the container is shaken, α
- The cyanoarylate is diffused into the liquefied carbon dioxide gas, uniformly sprayed with #IN4, and a spray adhesive having a desired Os ratio can be obtained.

As described above, alpha-cyanoacrylate-F is dissolved in moated sulfuric acid gas at the desired heating ratio and filled into a pressure vessel at a predetermined pressure. / is connected and sprayed onto the adhered object. At this time, the α-cyanoacrylate adhesive is granulated through the spray gun, accompanied by ultrafine particles and lightning-shaped dry ice. Although it is ejected as particles with a diameter of 1 to several times, it is snow-like.
The dry ice immediately sublimes and is entrained, leaving only the nine-α-cyanoacrylate on the surface to be adhered.

However, 4 hours of thunder-shaped dry ice jets caused powdery snow particles of scissors dry ice! Since the atmospheric moisture condensed on one surface remains together with the α-cyanoacrylate, it acts to promote the adhesive effect of α-cyanoacrylate.

Next, we tested the effect on the adhesion effect over time by dissolving liquefied carbon dioxide gas K11ll and storing nine α-cyanoacrylates. with a pressure of 5
The adhesive of the present invention, filled with 0jCt/cd, did not gel even after 6 months, and no influence on the adhesive effect was observed at all. Furthermore, during long-term storage of α-cyanoacrylate, polymerization occurs over a long period of time, resulting in gelation and an increase in viscosity, and K has the property of hardening. , HF, NO, and other acid gases, P-toluenesulfonic acid, methanesulfonic acid, etc., but the lI adhesive composition of the present invention can be used without adding the above-mentioned anionic anti-coagulation steel. Even after several months, α-cyanoacrylate polymerizes and remains stable for a long period of time without gelling.

Next, examples of the adhesive composition of the present invention will be shown.

A small-capacity pressure-resistant container (inner volume so*t) was filled with 20 g of 6cα-cyanoacrylate adhesive and heated to 25 Ct of liquefied carbon dioxide gas at 111 degrees Celsius to approximately 60 to 4/4
The filled pressure vessel was then shaken to promote uniform dissolution of α-cyanoacrylate into the liquefied carbon dioxide gas. Connect a spray gun to the filling port of this pressure-resistant container and make a 22o x 207-square 07k i
[KS OamOI! A similar aluminum plate was bonded by spraying the solution at a distance of - and applying it to a film thickness of 5 μm.

At this time, the coating thickness was extremely uniform, and there was no whitening phenomenon at all.After installation, the tensile paper shear adhesion strength was tested based on JI8-41/61, and the results were as follows. It was 160 noodles f/-. Also, the set time is 1
The adhesive composition of the present invention was sprayed again from a pressure container with a spray gun after 6 months had passed, and the performance was comparable to that of conventional α-cyanoacrylate adhesives. When tested, the test results were exactly the same as the previous test, and no gelation due to polymerization was observed during storage.

□□ヮyo. Yo50. , □A□. ``Since sulfuric acid gas is used as the solvent KL, it has many advantages such as: Since extremely fine particles and grains are generated, it can be used not only as an adhesive, but also as a coating agent, which can be uniformly applied even with an extremely thin film thickness. (b) And In the present invention, unlike the quadratic O which uses compressed gas as a propellant, α-cyanoacrylate is dissolved in liquefied carbon dioxide gas, the liquid composition is kept under pressure, and this pressure is used to effectively inject Therefore, the pressure and composition of the filler do not change depending on the use, and the spray is always maintained at a pressure of 18%, and α-cyanoacrylate of the same composition is sprayed, so uneven coating does not occur. By dissolving in carbon dioxide, α-cyanoacrylate can withstand long-term storage.
In addition, since there is no need to use stabilizers to prevent polymerization, coloring is achieved by using conventional stabilizers.

Inconveniences such as a decrease in adhesive strength do not occur. @) Even more non-toxic,
The use of nonflammable liquefied carbon dioxide improves safety, the environment, and
Hygiene-wise, it is much safer than conventional organic adhesives or fluorocarbon-based adhesives, and (θ) rubber,
The present invention can provide an industrially extremely effective adhesive that can be effectively used for adhering plastics and the like because it does not corrode them.

[Brief explanation of drawings]

The figure shows the composition and pressure at the time of death when α-cyanoacrylate is combined with carbon dioxide gas Kfi.

Claims (1)

[Claims] 16. An adhesive composition for spraying, which is prepared by dissolving an α-cyanoacrylate adhesive into liquefied carbon dioxide gas and storing it under pressure to maintain its liquid state.