JPS5933150B2 - Tube cap adhesive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in cap adhesives used for fixing caps to tubes of fluorescent lamps, incandescent lamps, and the like.

Generally, in order to fix a cap to a tube made of a glass material, adhesive is applied to the contact surface between the cap and the tube in advance, and after the cap is broken onto the tube, heat treatment is applied. etc., and it is fixed.

Then, as shown in the figure, the adhesive is applied to the nozzle cap using a nozzle 3 with a tank 1 and a valve 2 that hold the adhesive under pressure while keeping a predetermined gap between the nozzle cap 4 and the nozzle 3. This is done by arranging them so that they fit together.
In other words, if the valve 2 is opened for a certain period of time in the state shown, the adhesive 5
protrudes from the nozzle 3 in a ring shape and is applied to the inner peripheral surface of the mouthpiece cap 4 in a predetermined amount. Then, when the valve 2 is closed and the nozzle cap 4 is removed from the nozzle 3 position, the adhesive 5 is applied to a predetermined position of the nozzle cap 4. and,
The problem in this process is that the adhesive 5 is not easily cut from the nozzle 3 due to the adhesive being too soft or having high viscosity.

In other words, if the adhesive is poorly cut, when the valve 2 is closed and the nozzle cap 4 is removed from the nozzle 3, adhesive remains around the nozzle nozzle and swells or drips, causing the applied shape to be distorted. At the same time, the amount of adhesive applied becomes uneven, causing various problems, and in severe cases, the adhesive accumulated in the nozzle tube may make it impossible to perform the application process. Furthermore,
The required performance is that the adhesive maintains its proper hardness and adhesive properties for a certain period of time so that it does not lose its shape and is suitable for storage after application.

That is, since the pitch of the adhesive application process is faster than that of fixing the base cap to the tube, it is necessary to prepare the caps coated with adhesive in order to improve work efficiency. Then, they are stored in a container for a certain period of time, but in this case, the caps of the caps corrode each other in random directions within the container, so if the adhesive is soft, the applied adhesive will rub off on other caps. It adheres to the pins of the cap, etc., deteriorating the appearance characteristics and causing poor connection as a lamp. By the way, conventionally, this adhesive is obtained by dissolving materials such as natural resins such as rosin and ceramics, phenolic resin, carbonate/calcium fine powder, malachite green, and silicone resin in a solvent, and organic resins such as ethanol are used as the solvent. There are two types: one using a solvent and the other using trioxane.

Comparing properties suitable for storage after application, those using organic solvents are inexpensive but remain soft after application and have a short shelf life of about 3 days, while those using trioxane are not expensive. However, the difference was that it solidified after application and had a long storage period of over three months. That is, in the case of using an organic solvent, the entire process from mixing the materials to coating is performed at room temperature. Since the plasticity is maintained by the organic solvent before it is fixed by heating, it maintains the same soft state after application as it was at the time of application. The storage period is limited to a period during which the amount of solvent evaporation is small, and is as short as three days. On the other hand, those using trioxane as a solvent,
Since it has the property of solidifying at room temperature and softening when preheated, it is preheated to 500C to 60C only when softening is necessary for mixing, coating, etc.

For this reason, after application, it solidifies at room temperature and is in a state where the solvent is difficult to evaporate, giving it performance suitable for storage. Therefore, in view of the above circumstances, this invention is an improvement on the above, and provides an inexpensive adhesive that has low viscosity, can be easily cut from a nozzle, has appropriate hardness after application, and has a long shelf life. .

That is, the adhesive of the present invention uses an organic solvent such as ethanol as a solvent in order to produce it at a low cost, but in order to make it cut easily, it contains 10% calcium carbonate fine powder of 70μ or less. ~50% by weight, and in order to further improve storage performance, a resol type phenolic resin was used instead of the conventional novolak type as the phenol resin in the ingredients, and a resol type was used instead of the conventional novolac type. It is used by kneading it harder than adhesives that use . Note that novolak type phenolic resin is a resin made by reacting an excess of phenol with respect to formaldehyde under an acidic catalyst, and it hardens when heated with the addition of a substance that generates formaldehyde (hexamethyltetracine). It is something to do.

Furthermore, resol type phenolic resin is a resin made by reacting an excess of formaldehyde with respect to phenol under an alkaline catalyst, and is cured when heated.
The use of this resol-type phenolic resin allows it to be treated like adhesives using trioxane, where it is softened by preheating only during application, and then left in a hard state at room temperature when stored after application. It is for.

That is, the adhesive is hardened with an organic solvent and is softened by preheating at 50°C to 60°C only during application.
If a novolatile type phenolic resin is used as in the past, it will completely harden in about two hours and lose its function as an adhesive, so it cannot be handled in this way. However, products using resol type phenolic resin as in this invention retain their plasticity even after being heated for 15 hours, so they can be handled in the same way as adhesives using expensive trioxane, and they do not attach to the base cap. After application, it can be stored for about 7 days (about 3 months if stored in alcohol vapor), and from this point of view as well, it has good shelf life. In addition, if calcium carbonate in the particle size range of 70μ or less exceeds 50%, the viscosity of the adhesive becomes large and 10%
On the other hand, if it is less than that, the viscosity is too low, and in either case, the adhesive cannot be effectively applied to the base cap.

In short, in this invention, by limiting the particle size range of the calcium carbonate fine powder of 70μ or less to 10% to 50% by weight, it can be easily cut from the nozzle, and by using a resol type phenolic resin, it is inexpensive. Even if the adhesive uses an organic solvent, it can be preheated only at the time of application to soften it and make it hard enough to be stored at room temperature.

As explained above, the present invention is mainly composed of Resoltaif phenolic resin and fine powder of calcium carbonate, and in a product dissolved in an organic solvent, the particle size range of 70μ or less in the fine powder of calcium carbonate is 10 to 50% by weight. %, the adhesive for tube caps can be easily cut from the nozzle, and the application work to the cap cap can be performed smoothly, improving work efficiency.

In addition, it is possible to achieve the same effect as using trioxane without using expensive trioxane, and even if it is piled up randomly after application, it will not cause problems such as adhesion to other caps and pins or deformation. Since it does not occur, it is possible to make it with an inexpensive adhesive.

[Brief explanation of the drawing]

The figure is an explanatory diagram of a method of applying tube adhesive to the base cap. 4...Base cap, 5...Adhesive.

Claims (1)

[Claims] 1 The main components are a resol type phenolic resin and a fine powder of calcium carbonate, which is dissolved in an organic solvent, and is characterized in that the fine powder of calcium carbonate has a particle size range of 70μ or less at 10 to 50% by weight. Tube cap adhesive.