JPH0745182A - Adhesive for tubular bulb base and tubular bulb - Google Patents

Abstract

PURPOSE:To resist to downsizing of a tubular bulb, a temperature rise in a base part by realization of high output or the like and an increase in quantity of ultraviolet radiation or the like by using an adhesive formed by mixing an inorganic filler at a prescribed ratio in epoxy denaturated phenol resin when a glass bulb and a base are adhered to each other. CONSTITUTION:An adhesive is composed of epoxy denaturated phenol resin solution of 1 to 30weight% and an inorganic filler of 70 to 99weight%. The material composition is composed of 10% epoxy denaturated phenol resin solution of 18weight%, calcium carbonate powder having an average particle diameter of 50 to 200 mesh of 80weight% and hexamethylene tetramine solution of 2weight%. When a tubular bulb is assembled, a base 2 to which an adhesive 1 is stuck is installed on a sealing part 4 of a glass bulb 3 of a general electric lamp, and the base 2 is installed in an automatic electric lamp base adhering machine having a general-use base part heating iron pot, and it is heated for one minute at 200 deg.C being an ordinary heating condition, and the adhesive is baked, and the bulb 3 and the base 2 are adhered to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin type adhesive for adhering a glass bulb and a base.

[0002]

2. Description of the Related Art In general, bulbs such as light bulbs and fluorescent lamps have a base attached to the end of a bulb for holding power to the filament for discharging light and for supplying electricity to electrodes for discharging and for holding the bulb. Predetermined light emission and holding are performed by attaching and connecting.

The adhesive used for adhering the glass bulb and the base described above not only withstands the temperature rise of the base due to conduction heat or radiant heat from the bulb bulb, but also has a wavelength of about 365 nm emitted from the bulb. It must withstand the ultraviolet rays that are used, and that the filament of the bulb is broken, its life span is maintained, and the joint is maintained without deterioration until it is removed from the socket. Adhesives are often used.

The ultraviolet resistance of conventional phenol resin adhesives is iron chloride (FeCl ₃ ) which is an ultraviolet absorber.
However, it was mixed in the adhesive material although it was a trace amount due to addition or reaction.

On the other hand, recently, in lighting fixtures, miniaturization and sealing of fixtures, miniaturization of bulbs such as general electric bulbs and fluorescent lamps, higher output and longer life have been promoted, and along with this, adhesion As an agent, an adhesive having excellent heat resistance and ultraviolet resistance that meets these conditions is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and increases the temperature of the mouthpiece part due to downsizing of equipment and tube, high output, and increase of ultraviolet ray due to high output. It is an object of the present invention to provide an adhesive and a tube having excellent heat resistance and ultraviolet resistance that can withstand the above.

[0007]

According to a first aspect of the present invention, there is provided an adhesive for tube caps which is characterized in that an epoxy-modified phenolic resin and an inorganic filler are mixed and kneaded.

The tube spinneret adhesive according to claim 2 of the present invention comprises 1 to 30% by weight of an epoxy-modified phenolic resin,
The inorganic filler is characterized by being 70 to 99% by weight.

The tube according to claim 3 of the present invention is characterized in that the glass bulb and the mouthpiece are adhered to each other via the tube mouthpiece adhesive according to claim 1 or 2.

The bulb according to claim 4 of the present invention is characterized in that the bulb is a light bulb or a discharge lamp.

[0011]

The epoxy-modified phenol resin is a resin in which the epoxy groups are reacted and partly bonded during the phenol resin manufacturing process, and the epoxy groups have excellent heat resistance and ultraviolet resistance, and the adhesive strength does not decrease.

[0012]

EXAMPLES The details of the present invention will be described below with reference to examples.

EXAMPLE The present invention uses an epoxy-modified phenol resin as an adhesive component and calcium carbonate powder as an inorganic filler, and its material composition is as follows.

10% epoxy modified phenolic resin solution 18% by weight calcium carbonate powder (average particle size 50 to 200 mesh) 80% by weight hexamethylenetetramine solution 2% by weight The above 10% epoxy modified phenolic resin solution contains 30% by weight of phenolic resin. The above-mentioned three kinds of materials were kneaded in a solution (the balance: 70% by weight) to prepare a paste-like adhesive.

The structural formula (theory) of this epoxy-modified phenol resin is

[Chemical 1] Is.

A predetermined amount of this phenol resin adhesive was adhered to the E26 die using a general-purpose tube die adhesive filling machine. Then, as shown in FIG. 1, the base 2 to which the adhesive 1 is attached is attached to the sealing portion 4 of the glass bulb 3 of a general electric bulb, and the base of an automatic base bonding machine for electric bulbs equipped with a general-purpose base heating pot. Two parts of the die were installed in the partial heating pot, and the adhesive 1 was baked by heating at 220 ° C. for 1 minute which is a normal heating condition to bond the valve 3 and the die 2.

The composition of this adhesive after baking was 6.3% by weight of epoxy-modified phenolic resin and 93.6% by weight of calcium carbonate.

In this way, the light bulb manufactured under the same conditions as usual except for the adhesive material was taken out at random, and the base torque strength test of the base adhesion part after 0 hours, 1000 hours and 2000 hours of lighting was performed. All of them showed a strength of 5 N · m or more, which exceeds the Japanese Industrial Standard (JIS), and there was no problem at all.

Further, although the adhesive was injected and adhered into the mouthpiece by using air pressure using the above-mentioned general-purpose tube mouthpiece adhesive filling machine, the adhesive could be adhered in a predetermined amount without variation. . In addition, since this adhesive has good flowability, it does not clog the injection valve during injection, and it does not cause stringing and makes it difficult to work and stains the surroundings. Could be done without

Further, the above adhesive was subjected to a destructive test for heat resistance and ultraviolet resistance using a test piece. The results are shown in FIG. 2 (heat resistance) and FIG. 3 (UV resistance). In FIG. 2, the horizontal axis is the elapsed time (hours), the vertical axis is the tensile shear strength (Kg / cm ² ), and in FIG. 3, the horizontal axis is the elapsed time (hours) and the vertical axis is the residual rate (%). The solid black dots in the figure represent the product of the present invention, and the dotted line x points represent the conventional phenol resin adhesive for comparison.

The test piece tested for heat resistance has a length of 10 m.
2 plate plates made of glass measuring m × width 20 mm × thickness 1 mm
Prepare one sheet, and form an adhesive with a thickness of about 1 mm in an area of about 7 mm in length × about 10 mm in width between the plates, and bond them to about 180 ° C.
The adhesive was cured by heating for 15 minutes. Then, this test piece was placed in a constant temperature bath at 200 ° C., and five pieces were taken out every 100 hours, and pulled in directions opposite to each other in parallel with the bonding surface to measure shear strength.

As the test piece tested for ultraviolet resistance, a plate body made of glass having a length of 10 mm, a width of 20 mm, and a thickness of 1 mm is prepared, and the plate surface has a length of about 10 mm and a width of about 10 mm.
An adhesive having a thickness of about 1 mm was formed and adhered to the surface of the bulb of the tubular germicidal lamp GL15, and the adhesive was cured by heating at about 180 ° C. for 15 minutes. The germicidal lamp GL15 was continuously turned on to forcibly irradiate the adhesive with ultraviolet rays. And take out every 100 hours 500
A jig having a weight of gr was applied to the end of the test piece, and the number of remaining test pieces that did not come off was checked.

As is clear from FIGS. 2 and 3, the heat resistance of the product of the present invention was stronger from the beginning, and its superiority did not change even after aging. Further, the UV resistance did not change at the beginning, and the adhesive strength decreased with the passage of time (the amount of UV received increased), but the product of the present invention showed less decrease and was stronger.

Next, in the materials of the above-mentioned examples, a test was conducted for an appropriate mixing ratio of the epoxy-modified phenol resin and the inorganic filler calcium carbonate.
The average particle size, which is commonly used for testing, is 50-
Adhesives were made by variously changing the compounding ratio of 200 mesh calcium carbonate. Then, these various kinds of adhesives are adhered to the inside of the base, and the glass bulb of an actual general electric bulb is covered with the adhesive, and baked at 220 ° C. for 1 minute by an automatic base bonding machine to bond the valve and the base, and the above-mentioned Japanese Industrial Standard ( A spinneret torque strength test according to JIS) was performed.

From this strength test, when the compounding ratio of calcium carbonate was in the range of 70% by weight or more, all showed strength exceeding the use limit 3 N · m specified by JIS, and there was no problem. That is, the composition ratio of the adhesive after baking is 1 to 30% by weight, preferably 5 to 20% by weight of epoxy-modified phenol resin, 70 to 99% by weight of calcium carbonate, and preferably 80 to 95% by weight. The above adhesive strength was obtained.

The present invention is not limited to the above embodiment,
For example, the bulb to which the adhesive of the present invention can be applied is not limited to a light bulb that is required to have heat resistance, but may be a fluorescent lamp or a germicidal lamp that is required to have ultraviolet resistance, or a high pressure discharge lamp that is required to use both.

The phenol resin is not limited to the phenol resin modified with 10% epoxy and may be a phenol resin modified with 5% to 50% epoxy. Further, the curing agent is not limited to hexamethylene tetracine.

Further, although calcium carbonate powder was used as the inorganic filler in the above examples, it is not limited to calcium carbonate powder and may be silica powder or a mixed powder thereof, and the compounding ratio thereof is the calcium carbonate powder. It should have been the same ratio as.

[0029]

EFFECT OF THE INVENTION The base adhesive for a bulb of the present invention having the above constitution has high heat resistance and ultraviolet resistance, can maintain a high adhesive strength even under these environments, and can be used before the bulb reaches its life. In addition, it is possible to prevent the glass bulb from coming off from the base portion, and in particular, it is possible to reduce the deterioration due to the temperature rise and the ultraviolet radiation due to the recent miniaturization and higher output of lighting equipment and bulbs.

When attaching the adhesive to the die,
Since the adhesive has excellent fluidity and there is no phenomenon of pulling a thread,
The conventional adhesive filling machine can be used as it is, and the workability is extremely good.

[Brief description of drawings]

FIG. 1 is a partially sectional front view of a light bulb showing an embodiment of the present invention.

FIG. 2 is a graph showing the heat resistance of the adhesive of the present invention and the heat resistance of a conventional adhesive in comparison.

FIG. 3 is a graph showing the UV resistance of the adhesive of the present invention and the conventional adhesive in comparison.

[Explanation of symbols]

 1: Adhesive 2: Clasp 3: Glass bulb 4: Sealing part

Claims (4)

[Claims] 1. A base adhesive for a tube, comprising an epoxy-modified phenolic resin and an inorganic filler mixed and kneaded. 2. The adhesive according to claim 1, wherein the epoxy-modified phenolic resin is 1 to 30% by weight and the inorganic filler is 70 to 99% by weight. 3. A tube, wherein a glass bulb and a base are bonded together via the base adhesive for a tube according to claim 1 or 2. 4. The tube according to claim 3, wherein the tube is a light bulb or a discharge lamp.