JPS581767A - Adhesive for electric tube and bulb - Google Patents

Abstract

PURPOSE:To provide a low cost adhesive for electric tube and bulb excellent in resistance to heat and water and electrical insulating property, prepared by adding an extender to a thermosetting silicone rubber-based resin which contains a fluid silicone rubber and a fluid silicon-based crosslinking agent. CONSTITUTION:The adhesive is prepared by adding 5-70wt% extender to a thermosetting silicone rubber-based resin which contains a fluid silicone rubber and a fluid silicon-based crosslinking agent. The extenders are glass powder, a heat-resistant resin powder (e.g. phenolic resin), stone dust, waste fluophor, etc. The adhesive is suitable as binder 9 to join container 1, cup 4 and base plate 6 and as binder 9 to join both ends of U-shaped fluorescent lamp 2, an end of lighting tube 7 and tubular parts in the production of single-ended fluorescent lamp unit.

Description

[Detailed description of the invention] The present invention relates to an adhesive for tubes.

For example, in light bulbs, when attaching a cap to the sealed end of a glass bulb, the adhesive filled inside the cap is heated and hardened from the outside of the cap, and the cap is bonded to the sealed end of the glass pulp. .

Conventional adhesives for tubes of this type are made by blending rosin, shellac, calcium carbonate, etc. with novolac type phenolic resin or resol type phenolic resin.

It is further kneaded with an organic solvent such as ethyl alcohol, and after fitting the cap filled with this adhesive to the sealed end of the glass pulp, the adhesive effect is achieved by heat curing of the phenolic resin.

To explain the function of such an adhesive, the phenol resin is the main agent that adheres the sealed end of the glass bulb and the cap. Rosin and shellac are softened by the rise in temperature during one lighting operation, thereby exerting a buffering effect on the glass pulp. Still, calcium carbonate is a bulking agent.

However, such adhesives require a heating temperature of around 20° C. for curing, and the amount of heat used is large. However, due to various usage conditions, such as long-term use in high-temperature or high-humidity environments, sudden exposure to water damage, and other reasons, the adhesive may deteriorate extremely, resulting in the so-called loose cap. In addition, there is a drawback that the electrical insulation properties are also lowered. In addition, if you try to increase the amount of phenolic resin to strengthen the adhesive force, the tightening force of the adhesive against the glass pulp will become too strong, resulting in cracks in the glass pulp in the part of the adhesive. There is naturally a limit to the amount of phenolic resin that can be added to the glass bulb. When a bulb is coated with a white light-diffusing coating and a cap is attached to the glass bulb using such an adhesive, various organic gases are generated when the adhesive is heated and cured. However, it has been found that there is a problem in that the light-diffusing coating changes color to black.

It has also been found that the organic gas corrodes metal parts such as lead wire breakage, and when a lead wire with a small wire diameter is used, there is a risk that the lead wire may break due to long-term use, resulting in a disadvantage.

The present invention has been able to eliminate the above-mentioned problems, and the inventors described below have made various studies to eliminate the above-mentioned problems.
A tube adhesive made of a thermosetting silicone rubber resin containing a fluid silicone rubber and a fluid silicone crosslinking agent with a weight coefficient of 5 to 70 added thereto has a low heat consumption during heat curing. It has good properties such as heat resistance, water resistance, and immersion resistance, and also has good electrical insulation, and even in glass bulbs with a light-diffusing coating formed on the inner surface. It was discovered that it has extremely excellent performance, without causing discoloration of the light-diffusing coating, without the risk of corroding metal parts, and at low cost. As the extender, glass powder, phenol, heat-resistant resin powder such as PBT, waste phosphor, etc. are used. Regarding the actual use of the above tube adhesive.

In addition, silicone curing accelerator. Use a mixture of silicone oil diluent and alcohol dispersant.

Next, an example in which the bulb adhesive according to the present invention is applied to a single-cap type fluorescent lamp device will be described with reference to the drawings.

First, an example of a single-cap type fluorescent lamp device will be explained with reference to FIG. In the figure, a non-linear fluorescent lamp, such as a U-shaped fluorescent lamp 2, is built into a container 1, and a ballast 5 is built into a cup 4 with a light bulb base 3 attached to the bottom. There is. - At the opening of the cup 4, a cap-shaped base 5 is provided to close the opening.

A panel 6 is provided, into which both legs of two I/CU shaped fluorescent lamps 20 of the three i-shaped sections provided on the top are inserted and supported;
The end of the lighting tube 7 is inserted into and supported by the other one. Note that 8 is a noise prevention capacitor connected in parallel with the lighting tube 7. The container 1, the cup 4, and the base 6 are fixed and integrated with an adhesive 9. A light diffusing film 10 made of titanium oxide or the like is formed on the inner surface of the container 1 .

Further, both ends of the U-shaped fluorescent lamp 2 and the ends of the lighting tube 7 and each cylindrical part are fixed with the same adhesive 9 as described above.

The adhesive 9 has a compounding ratio as shown in the table below.

Flowable silicone rubber 28% by weight Flowable silicone rubber crosslinking agent 28% by weight Silicone curing accelerator 2% by weight purified glass powder (extending agent)
32% by weight Methanol (dispersant) 3% by weight
Silicone oil diluent 7% by weight These are blended to obtain a silicone rubber comparant, which is defoamed using a vacuum device within about 60 minutes to form an adhesive. - This adhesive is filled into the predetermined locations in various amounts, and is applied from the outside at a temperature of 100 to 120°C.
Heat and dry for 0 minutes. After the single-capped fluorescent lamp device obtained by changing the amount of adhesive filled in this way was left for 24 hours,
When testing the cup 4 against the container 1 under various conditions, the adhesion properties of each were investigated.
The results are shown in the table below. however.

The number of tests for each sample is 10.

Margin Note: When we tested a fluorescent lamp device assembled by applying a phenolic resin adhesive to the above structure, we found that it remained immersed in room temperature water for 10Q hours and 200 hours for 100 hours.
After heating at °C, the adhesive strength of the metal part was 2 N-m or less, which was a significant deterioration.

As is clear from the above table, the adhesive for VC tubes according to the present invention has excellent adhesive properties.

However, the heating temperature of such adhesive is 100-120℃.
℃, so only a small amount of heat is used.There is no corrosion of metal gas, which prevents M from the lead wires, etc., and since there is no generation of contaminating gas, there is no contamination of the light diffusion film. It was also confirmed that this can be prevented.

Next, one inventor began experimenting with the amount of filler added to the heat-curable silicone rubber resin.

As shown in FIG. 2, when the content of the filler added exceeds 7° by weight, the adhesive strength in the adhesive properties determined by the rubbing test decreased and was no longer fully satisfactory. If the number is less than 5 times, the effect of cost reduction will be diminished, and it will only take time and effort to add it, and there will be no benefit. Therefore, the content of the extender added to the heat-curable silicone rubber resin needs to be in the range of 5 to 70% by weight.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example in which the adhesive for bulbs according to the present invention is applied to a single-capped fluorescent lamp device, and FIG. 2 is a diagram showing the relationship between the content of filler added and adhesive strength. 1...Container, 2...U-shaped fluorescent lamp, 3
...Light bulb cap, 4...Cup, 5...
····stabilizer. 6...Base, 7...Lighting tube, 8...
...Noise prevention capacitor, 9...Adhesive,
10...Light diffusion film. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] 1. An adhesive for tubes, comprising a thermosetting silicone rubber-based resin containing a fluid silicone rubber and a fluid silicone-based crosslinking agent, to which 6 to 70% by weight of an extender is added.