JPH11156287A - Coating application method of adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a drying time and to obviate he dissipation and loss of a solvent by immersing materials to be coated into a heated adhesive soln. in a vacuum vessel, applying an adhesive soln. on the materials to be coated and heating the materials to be coated, then discharging the adhesive soln. from the vacuum vessel and then vacuum drying. SOLUTION: The materials to be coated, such as brake shoe bodies, which are hooked to hangers and are lined up on a pallet are put together with this pallet into the vacuum vessel and the pressure in the vacuum vessel is reduced. The heated adhesive soln. (for example, an adhesive, such as phenolic resin based adhesive, dissolved in a solvent, such as methanol) is supplied into the vessel. The pressure in the vessel is then released and the materials to be coated are immersed into the adhesive soln. to heat the materials to be coated. The adhesive soln. is thereafter slowly discharged from the bottom of the vacuum vessel by a pump. After the adhesive soln. is discharged, the pressure in the vacuum vessel is rescued to evaporate the solvent of the adhesive soln. The evaporated solvent is recovered by a trap, etc. The pressure reduction is then released and the pallet is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for uniformly applying an adhesive to the surface of an object.

[0002]

2. Description of the Related Art As a method of applying an adhesive to the surface of an object to be coated such as a metal product, the object to be hung on a hanger is immersed in an adhesive solution in an immersion tank, and then the hot-air drier or the like is pulled up. And drying the solvent. However, in this method, there is a problem that the solvent volatilizes during immersion or drying, and it is impossible to recover the solvent, resulting in a large loss and a long drying time. Further, it is difficult to uniformly apply the adhesive of the object to be coated simply by pulling up the object to be coated.

[0003]

SUMMARY OF THE INVENTION The present invention provides a method for applying an adhesive which can uniformly apply the adhesive to the surface of an object to be coated, has a short drying time, and does not cause evaporation or loss of a solvent. The purpose is to:

[0004]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, after immersing an object to be coated in a heated adhesive solution in a vacuum vessel, By discharging the adhesive solution from the substrate and then drying under reduced pressure, the solvent can be dried in a short time without volatilization and loss of the solvent, and the coating can be uniformly performed on the surface of the object to be coated. The present invention has been completed based on the findings.

That is, the present invention provides a step of supplying a heated adhesive solution into a vacuum container, immersing the object to be coated in the adhesive solution in the vacuum container, applying the adhesive solution to the object, and applying the adhesive solution to the object. Provided is a method for applying an adhesive, comprising: a step of heating an object; a step of discharging an adhesive solution from a vacuum container; and a step of evaporating a solvent of the adhesive solution applied to an object by reducing the pressure in the vacuum container. Things.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The object to be coated by the coating method of the present invention is not particularly limited, but is preferably applied to the formation of an adhesive film on a brake shoe body. That is, the brake shoe is manufactured by bonding the lining to the shoe rim of the brake shoe body, and an adhesive solution called a primer is applied to the bonding surface between the shoe rim and the lining to facilitate the bonding between the shoe rim and the lining. At the same time, the surface of the brake shoe body other than the adhesive surface is treated to prevent rust. This primer is prepared by dissolving an adhesive such as a phenolic resin-based adhesive or an epoxy resin-based adhesive in a solvent such as methanol, methyl ethyl ketone or toluene at a concentration of 10 to 20% by weight. It is required that a proper coating film can be formed quickly and that the solvent does not evaporate during drying.
Therefore, the application method of the present invention is suitably used for applying the primer to the brake shoe body.

In the method of the present invention, a heated adhesive solution is first supplied into a vacuum vessel capable of reducing the pressure inside the vessel. Next, the object to be coated is immersed in an adhesive solution in a vacuum vessel to apply the adhesive solution to the object to be coated, and the object to be coated is heated.

[0008] As the adhesive solution, an adhesive such as a phenol resin adhesive or an epoxy resin adhesive may be methanol,
A solution dissolved in a solvent such as methyl ethyl ketone or toluene is used. The thickness of the adhesive can be adjusted by changing the concentration of the adhesive. The adhesive solution is heated before dipping the object to be coated. When the temperature of the adhesive solution is immersed in the heated adhesive solution,
It is preferable that the temperature be such that the amount of heat stored in the object to be coated by the immersion is such that the adhesive solution remaining on the object after the immersion can be evaporated in a reduced-pressure atmosphere. This temperature was determined using a brake shoe body as the object to be coated and a 16% by weight solution of phenolic resin adhesive (solvent: a mixed solvent of methanol (60% by weight) / methyl ethyl ketone (40% by weight)) as the adhesive solution. 40-60
It is preferably set to ° C.

The object to be coated can be hung on a pallet, placed in a pallet, placed in a vacuum vessel together with the pallet, and the object to be coated can be immersed in an adhesive solution.

In the method of the present invention, the adhesive solution is discharged from the vacuum container. It is preferable that the adhesive solution is slowly discharged from the bottom of the vacuum container by a pump for 20 seconds to 1 minute. By employing such a discharging method, the adhesive solution can be uniformly applied to the object to be coated, as compared with a method of simply lifting the object to be applied.

After discharging the adhesive solution, the vacuum container is sealed and the pressure in the container is reduced. The degree of pressure reduction is preferably 10 to 20 torr when the above-mentioned adhesive solution is used, and it is preferable to reduce the pressure for 30 seconds to 2 minutes. By reducing the pressure in the vacuum vessel, the solvent can be evaporated without volatilizing, and the evaporated solvent can be easily recovered by using a trap or the like, which is excellent in environmental hygiene. In addition, the drying time of the solvent can be quickly performed as compared with the conventional method.

[0012]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples of the present invention and Comparative Examples thereof, but the present invention is not limited to these Examples.

Example 1 Twenty brake shoe bodies were arranged on a hanger, and eight rows were arranged on a pallet. This pallet is placed in a vacuum container (600 mm
× 900 mm × 500 mmH) and the vacuum vessel was capped. The pressure in the vacuum vessel was reduced to 20 torr, the valve was opened, and the adhesive solution was heated to 40 ° C. (a 16% by weight solution of a phenolic adhesive (solvent: a mixed solvent of methanol (60% by weight) / methyl ethyl ketone (40% by weight))). 180 liters were supplied into the container, then the pressure was released, the brake shoe body was immersed in the adhesive solution for 30 seconds, and the brake shoe body was heated to 40 ° C. Thereafter, the adhesive solution was evacuated by the pump for 30 seconds. After slowly discharging from the bottom of the container, the adhesive solution was uniformly applied to the surface of the brake shoe body.After discharging the adhesive solution, the valve was closed, and the pressure in the vacuum container was reduced for 60 seconds at 10 torr. The solvent of the adhesive solution was evaporated, the evaporated solvent was collected by a trap, the pressure was released, the lid of the vacuum vessel was opened, and the pallet was taken out. . Coatings of adhesive on the surface of the brake shoe body is not uniformly formed.

[0014]

According to the present invention, a uniform coating film of the adhesive can be formed on the surface of the object to be coated, and the drying time of the solvent can be greatly reduced. Further, since the solvent does not volatilize and can be recovered, there is no loss and the coating method is excellent in environmental hygiene.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masatoshi Uchino Japan Field Co., Ltd. 7-20-2 Oizumi Gakuencho, Nerima-ku, Tokyo

Claims (3)

[Claims] 1. A step of supplying a heated adhesive solution into a vacuum container, wherein the object to be coated is immersed in the adhesive solution in the vacuum container, the adhesive solution is applied to the object to be coated, and the object is applied. A method for applying an adhesive, comprising: a step of heating, a step of discharging the adhesive solution from the vacuum container, and a step of evaporating the solvent of the adhesive solution applied to the object by reducing the pressure in the vacuum container. 2. The method for applying an adhesive according to claim 1, wherein the object to be applied is a brake shoe body. 3. The method for applying an adhesive according to claim 1, wherein in the step of evaporating the solvent of the adhesive solution applied to the object by reducing the pressure in the vacuum container, the evaporated solvent is recovered.