JPH0256848A - Base adhesive for tube bulb - Google Patents

Abstract

PURPOSE:To make it possible to use silicone resin type base adhesive to a conventional phenol resin type base adhesive filling machine as it is, and to improve the workability, by making the mean particle diameter of an inorganic filler which is mixed to a silicone resin type base adhesive 10mu or more, and making the mixing ratio of the filler in the scope 72 to 97wt.%. CONSTITUTION:As the components of a silicon resin type base adhesive, an inorganic filler whose mean particle diameter is 10mu or more is mixed 72 to 97wt.% to a silicone resin. In a research of the relation between the mean particle diameter and the mixing ratio of the inorganic filler, and the workability, the result was as the diagram in the figure. The figure shows the result when the inorganic filler was calucium carbonate or silica and its mean particle diameter was 10mu, 50mu, or 100mu. From the figure, it is clear that the level of viscosity is almost same as the conventional phenol resin type base adhesive, in the mixing ratio 72 to 97wt.% when the mean particle diameter of the inorganic filler is 10mu or more, and there is no problem to use the silicon resin type base adhesive instead of the phenol resin type base adhesive. Consequently, by using the conventional phenol resin type base adhesive filling machine as it is, the workability can be improved.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention utilizes the manufacturing equipment and production line for manufacturing tubes using a phenolic resin cap adhesive, and This invention relates to a silicone resin cap adhesive that can be used to produce tubes.

(Prior Art) Conventionally, phenolic resin adhesives have been used to bond caps of bulbs such as general light bulbs and fluorescent lamps.

In recent years, there has been a trend toward smaller size and higher output in these general light bulbs and fluorescent lamps, and with this trend, silicone resin adhesives (Special Publication No. 37-18948) with excellent heat resistance and ultraviolet resistance have been developed.
Publication No. 2) has come to attract attention.

(Problem to be solved by the invention) Conventional silicone resin adhesives generally contain inorganic fillers with an average particle size of around 5μ, and harden slowly at the curing temperature of phenolic resin adhesives. A normal cap bonding machine that requires the use of adhesives could not be used, and a separate production line had to be set up for the cap bonding process.

In addition, conventional silicone resin adhesives have a high viscosity, causing stringiness during work similar to that seen in starch syrup or natto, and when used in cement filling machines, it is not only difficult to inject a fixed amount of adhesive. , the adhesive does not stop pulling even after injection is finished,
The cement filling machine for phenolic resin adhesives could not be reused because it would stain the nozzle and working environment, so the adhesive filling process had to be specially organized using a specially made filling machine.

In this way, in the past, dedicated manufacturing equipment or special production lines were used to use silicone resin-based cap adhesives, which made it difficult to organize assembly lines, resulting in low production efficiency and high costs. is unavoidable, and it cannot be ignored that silicone resin itself is expensive.

Therefore, one problem of the present invention is to make it possible to use the conventional filling machine for phenolic resin adhesive as it is and to demonstrate good workability.
This silicone resin also cures in the same heating time as conventional phenolic resin adhesives, and as a result, existing manufacturing equipment and production lines that are designed to use conventional phenolic resin adhesives can be used as is. The purpose of the present invention is to provide a base adhesive.

[Structure of the invention]

(Means for Solving Problem 111) The present invention uses a silicone resin as an adhesive component, and by blending 72 to 97% by weight of an inorganic filler with an average particle size of 10μ or more, it can be used as a phenolic resin base adhesive. With the same heating time, substantial adhesive strength can be obtained that does not interfere with subsequent operations, and the filling process can be performed satisfactorily using conventional filling machines for phenolic resin-based cap adhesives. , which can be used as is in conventional production lines.

(Function) The present inventor focused on the fact that when an inorganic filler with a large particle size is added to an adhesive, the particles of the filler become intertwined with each other, reinforcing the adhesive strength. By appropriately selecting the average particle size and compounding ratio of the inorganic filler to be blended into the adhesive, even with the same heating time as when using conventional phenolic resin adhesives, there is no possibility of insufficient curing of the silicone resin itself. The lack of strength was compensated for by the reinforcing effect of the inorganic filler, and the adhesive strength was obtained to the extent that it did not interfere with operations after bonding the cap, and then by curing over time, the adhesive strength exceeded the specified value.

Furthermore, the present inventor noticed that increasing the blending ratio of inorganic fillers can improve the stringiness phenomenon of silicone resin,
By adjusting the blending ratio appropriately, it can be used as is in conventional phenolic resin-based cap adhesive filling machines, making it possible to incorporate it into the same production line, and eliminating the risk of contaminating the cap or working environment. Furthermore, we have also discovered that if the blending ratio of the inorganic filler is increased to a range that improves workability, the adhesive strength can be improved to the above-mentioned required level, and the product can be supplied at a lower cost.

(Example) The details of the present invention will be explained with reference to the following examples.

Example 1 In this example, calcium carbonate powder was used as an inorganic filler, and its material composition was as follows.

Silicone resin (TSE series manufactured by Toshiba Silicone Corporation)
20% by weight Calcium carbonate powder (manufactured by Onigawara Calcium Co., Ltd., heavy calcium carbonate average particle diameter 80μ specifications) 80% by weight These two components are kneaded with a solvent such as xylene equivalent to 7% by weight of the total to form a paste adhesive. Adjust this, fill it into a Rokin cement filling machine made by Omen Kikai Co., Ltd. manufactured for use with phenolic resin cap adhesive, apply normal air pressure, attach a light bulb cap to the injection port, The injection valve of the filling machine was opened and a predetermined amount of adhesive was injected to adhere to the opening of the mouthpiece as specified.At this time, the adhesive had the same level of tackiness and cutting properties as phenolic resin mouthpiece adhesive. Despite being a filling machine manufactured for phenolic resin-based cap adhesives, it is possible to inject a fixed amount, and there is little variation in the amount of adhesion, making it possible to inject just a single cap or a single cap. There was almost no soiling of the workplace, and there was almost no change in working conditions or work efficiency.

Next, the cap coated with this silicone resin cap adhesive is attached to a light bulb, placed in a regular light bulb cap adhesive machine, and heated under normal heating conditions, i.e., 220°C, for 1 minute to bake the adhesive. Ta. Take the light bulb with the cap attached in this way,
Suppression and blows to a degree that rarely occur in the subsequent process,
When tested by applying an external force such as J2 jitter to the cap, no abnormalities such as misalignment, bending, twisting, peeling, etc. were observed in one cap. There were no problems. In addition, even after the baking process is completed, the silicone resin continues to harden, and when completed, all products exhibit adhesive strength that exceeds regulations, and in a 5,000-hour life test, the silicone resin continues to harden. The strength is 5N, which exceeds the Japanese Industrial Standards (JIS).
-1 or more, there was no problem at all.

Furthermore, since the calcium carbonate powder of this example is inexpensive, it can be manufactured at low cost.

Therefore, in order to examine the reason why the cap adhesive of this example exhibits high adhesive strength despite the insufficient curing of the silicone resin, the portion of the light bulb that was bonded to the cap was cut out and its cross section was examined. The results are schematically shown in FIG. That is, ■ is a glass bulb, ■ is a cap, and ■ is a simulated cap adhesive of this example. The cap adhesive (■) is a mixture of an inorganic filler (3
2) has a mixed structure. Thus, the feature of the present invention is that the particles of the inorganic filler (32) engage with the particles of other inorganic filler (32) through the protruding corners and support each other. In addition, in this figure, the inorganic filler (32
) was simulated with a pentagonal shape, but in reality it has an irregular shape, and many have sharp protruding corners.

As shown in this figure, the particles of the inorganic filler (32) engage and support each other, which means that the silicone resin (
This is thought to be the reason why, despite the insufficient curing of 31), an apparently strong adhesive force was exhibited as soon as the solvent evaporated.

Example 2 This example uses silica powder as an inorganic filler, and its material composition is as follows.

Silicone resin (same as Example 1) 15% by weight silica powder (
Crystallite (manufactured by Ryumori Co., Ltd.) (average particle size 100μ) 8
5% by weight This material was also formed into a base adhesive in the same manner as in Example 1, and similarly filled in a Rokin cement filling machine manufactured by Omen Kikai Co., Ltd. and adhered to the base of a light bulb. It can be used under the same conditions as resin-based nozzle adhesives, can be injected in the same quantity, has little variation in the amount of adhered material, hardly contaminates one nozzle or the work area, and is much easier to use than conventional phenolic resin-based nozzle adhesives. There was almost no difference compared to when using

Furthermore, the cap coated with the adhesive of Example 2 was adhered to a light bulb using a cap bonding machine in the same manner as described above. It exhibited adhesive strength that did not interfere with work, and was able to be incorporated into conventional light bulb production lines as is. Also, baking is done after the process is finished.
Similarly, the curing of the silicone resin further progressed and the adhesive strength further increased. Furthermore, the product of Example 2 could also be manufactured at a significantly low cost.

Next, regarding the material compositions of both of the above-mentioned examples.

The relationship between the average particle size of the inorganic filler and the adhesive strength immediately after baking was investigated. In this test, the baking conditions were all set at 220° C. for 1 minute as described above, and the adhesive strength was expressed in units of N-kaku according to the base adhesive strength test specified by JIS. The results are shown in FIG.

In the figure, the horizontal axis shows the average particle size of the inorganic filler in μ units, and the vertical axis shows the adhesive strength in N·■ units.

The solid line indicates the case where the inorganic filler is calcium carbonate powder, and the broken line indicates the case where the inorganic filler is silica.
The limit strength for use of cap adhesive specified by IS, 3N, is indicated by a chain line. From this figure 2, the preferred average particle size of the inorganic filler is 10μ or more, and if this condition is met, an adhesive strength of 3N or more specified in the Japanese Industrial Standards (JISC7501) for general lighting bulbs can be obtained. It is clear that

Next, in the materials of both examples described above, the average particle size of the inorganic filler was 80μ in the case of calcium carbonate,
In the case of silica, it was set to 100μ, and the blending ratio of the inorganic filler was varied and baked at 220°C for 1 minute.

The relationship between the compounding ratio and the adhesive strength immediately after baking was investigated. The measurement method for this test was also based on the above-mentioned JIS standard. The results are shown in Figure 3, where the horizontal axis shows the blending ratio of the inorganic filler in weight percent, and the vertical axis shows the adhesive strength in N's, and the solid line shows the inorganic filler. is calcium carbonate, the broken line is silica, and the #I line is a phenolic resin cap adhesive for comparison.
From the figure.

It has been revealed that if the blending ratio of the inorganic filler is in the range of 50 to 97% by weight, all of them exceed the usage limit of 3111'm defined by JIS and can be used in the same way as the phenolic resin base adhesive. Furthermore, the adhesive strength immediately after seizure is slightly lower than that of phenolic resin cap adhesives, so the seizure that sometimes occurs when using phenolic resin cap adhesives is an incidental effect that prevents cracks from occurring in the valve during the subsequent cooling process. was also seen.

Furthermore, in the above examples, the relationship between the average particle size and blending ratio of the inorganic filler and workability was investigated. In this test, a predetermined amount of the filler was applied to the light bulb cap using the above-mentioned phenolic resin cap adhesive filling machine for light bulbs made by Omen Kikai Co., Ltd. (1) by operating it with normal air pressure. The degree of stringiness at that time was visually evaluated. The results are shown in Figure 4. In Figure 4, the horizontal axis shows the blending ratio of the inorganic filler in weight percent, and the vertical axis shows the stringing phenomenon based on sensory evaluation. In the case of calcium carbonate, the broken line indicates the case of silica, and the average particle size is 10μ in both cases.

The cases of 50μ and 100μ are described, and for comparison, the relationship between the inorganic filler and workability of a phenol resin base adhesive is also described. From this Figure 4, if the average particle size of the inorganic filler is 10μ or more, the blending ratio is 72μ.
It was found that within the range of ~97% by weight, the degree of stringiness was almost the same as that of conventional phenolic resin based nozzle adhesives, and it was found that it could be completely replaced without any problem in the work. Furthermore, if we compare this Figure 4 with Figure 3, if the blending ratio of the inorganic filler is in the range of 72 to 97% by weight, the adhesive strength will also be good, even if it is replaced with a phenolic resin base adhesive. It is clear that the conventional production line can be used as is.

Therefore, in the present invention, the preferred average particle size of the inorganic filler to be blended into the silicone resin base adhesive is set to 10 microns or more, and the blending ratio is limited to a range of 72 to 97% by weight. The same applies even if the inorganic filler is something other than calcium carbonate or silica.

Thus, the base adhesive of the present invention can be applied to the bases of many types of bulbs, and is particularly suitable for applications requiring heat resistance and ultraviolet resistance, such as germicidal lamps and high-output light bulbs. Furthermore, since inorganic fillers are generally significantly cheaper than silicone resins, they also have the added benefit of lowering the price of the adhesive.

〔Effect of the invention〕

In this way, the tube cap adhesive of the present invention uses silicone resin as an adhesive component, and contains 72 to 97% by weight of an inorganic filler with an average particle size of 10 μ or more, so it is superior to conventional phenolic resin cap adhesives. It can be used as is in a filling machine for filling agents, and it can be used as is in a cap bonding machine that performs cap baking using conventional phenolic resin cap adhesive and baked under the same conditions without causing any problems in subsequent work. It can now be used as is in conventional production lines.

[Brief explanation of the drawing]

Fig. 1 is a schematic enlarged cross-sectional view showing the adhesion state of one embodiment of the tube cap adhesive of the present invention, and Fig. 2 shows the relationship between the average particle size of the inorganic filler and adhesive strength in the present invention. graph,
FIG. 3 is a graph showing the relationship between the blending ratio of inorganic fillers and adhesive strength, and FIG. 4 is a graph showing the influence of the blending ratio of inorganic fillers and average particle size on workability. ■...Glass bulb ■...Cap ■...Base adhesive (31)...Silicon resin (32)...Inorganic filler agent Patent attorney Norio Ogo I is a seven-pronged Nog. Lua Collection Isominato Pa Figure Left O 乎灼ML き（P-） go bo 7o go qo to. History 11 G#'s Hiko staunch L (Raw-1x) Figure IO DeO Muren Chungr@XXn6hihi [Small amount 2]

Claims (1)

[Claims] 1. A tube cap adhesive characterized in that silicone resin is used as an adhesive component and 72 to 97% by weight of an inorganic filler having an average particle size of 10 μm or more is blended therein.