JPH0877982A - Base adhesive for tubular lamp and tubular lamp - Google Patents

Abstract

PURPOSE: To provide an adhesive and a tubular lap both of which have excellent heat resistance and ultraviolet resistance and can resist against temperature increase in a base part,, which is due to compactification of an apparatus and the tubular lamp or increase in output, and ultraviolet ray increase, which is due to increase in output. CONSTITUTION: A base adhesive 1 for a tubular lamp consists of the first inorganic filling whose mean grain size is 147μm or less, the second inorganic falling containing 1 to 20% by weigh of a vertically long grain (needle grain) substance, whose longest part, length is 300% of that of the shortest part or more, to the first inorganic filling, and adhesive base resin. In this way, heat resistance and ultraviolet resistance are increased, and a glass bulb 3 is prevented from falling off from a base part 2 before a life of the tubular lamp runs out. In application of the adhesive 1 to the base 2, a conventional adhesive filling device can be directly used and workability is extremely good, as the adhesive 1 is excellent in fluidity and such a phenomenon as cobwebbing is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube cap adhesive suitable for mounting a cap on a glass bulb.

[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 bonding the glass bulb and the base is resistant to the temperature rise of the base due to the conduction heat and the radiant heat from the bulb bulb, and the ultraviolet ray centered at 365 nm emitted from the bulb. The filament of the bulb must be broken and its life is fulfilled, and the joint must be maintained without deterioration until it is removed from the socket.

As an adhesive material generally used for a tube cap, for example, a thermosetting phenolic resin as an adhesive main agent, an inorganic filler such as calcium carbonate, shellac, rosin and a curing agent are used. It is used to combine these by kneading and kneading and adding an organic solvent such as alcohol to a predetermined viscosity, and interposing it between the valve and the base to perform heat treatment to join the two. It was

Such an adhesive has little deterioration due to heat from the bulb bulb or ultraviolet rays, and is sufficiently durable for ordinary use.

On the other hand, the recent trend of lighting fixtures is to make them smaller and more hermetically sealed, so that the bulbs such as general electric bulbs and fluorescent lamps mounted on these fixtures are also smaller, higher in output and longer in life. As a result of this, there is a demand for an adhesive that meets these conditions and has a high bonding strength with excellent heat resistance and UV resistance.

[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 and high output of instruments and tubes and increase of ultraviolet rays 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 and having a high bonding strength.

[0007]

[Means for Solving the Problems] The base adhesive for tube of the present invention has an average particle size of 147 μm or less (US sieve 100).
1% to 20% by weight of the first inorganic filler with respect to the first inorganic filler having a longest part length of 300% or more of the shortest part length of the first inorganic filler (mesh or less) And a resin as an adhesive main agent.

Further, the tube mouthpiece adhesive of the present invention is characterized in that the resin as an adhesive main agent is at least one of a phenol resin and a silicone resin.

Further, the adhesive for tube cap of the present invention is characterized in that the first inorganic filler is at least one of calcium carbonate and silica.

Further, the tube of the present invention is characterized in that the glass bulb and the mouthpiece are adhered to each other via the tube mouthpiece adhesive of any one of claims 1 to 3. Furthermore, the bulb of the present invention is characterized in that the bulb according to claim 4 is a light bulb or a discharge lamp.

[0011]

[Function] The inorganic filler to be mixed with the adhesive main agent is a mixture of two kinds of a fine powdery first inorganic filler and a vertically elongated grain (acicular grain) second inorganic filler. Finely powdered inorganic fillers are combined in a wedge shape between the particles of the second inorganic fillers of vertically elongated particles (needle-like particles), and the cured adhesive main agent is interposed between them to form particles. Since they are bound to each other, the joint strength can be improved.

Further, the adhesive improves the fluidity due to the incorporation of the inorganic filler of vertically elongated particles (needle-like particles), and when the adhesive is attached to the die, threading does not occur and workability can be improved. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings.

In the present invention, a phenol resin is used as an adhesive main agent, and the first inorganic filler A contains, for example, 70% by weight or more of calcium carbonate, and the average particle size thereof is 147 μm or less (US sieve (Tyler sieve) 1
00 mesh or less), of which the average particle size is 10μ
Most of 72% by weight or less are mixed,
Similarly, as the second inorganic filler B material, vertically long grains (needle-shaped grains) having the longest length of the fossil shell powder of 300% or more of the shortest length in the grain size of the above-mentioned A material, and a hardening agent solution As a solution, a hexamethylenetetramine solution was prepared.

The average particle size used in the present invention is classified according to particle size rank using a JIS sieve (standard sieve), the distribution is obtained by weight ratio for each particle size rank, and the weighted average is calculated from this distribution. This is the calculated particle size. Further, when the particles cannot be separated by sieving due to their small diameter, the distribution was obtained by weight ratio using an ultracentrifugal automatic distribution measuring device (CAPA-700 manufactured by Horiba Ltd.), and the average particle size was calculated by a weighted average.

Then, the above-mentioned four kinds of materials were mixed in the following amounts and kneaded to prepare a paste-like adhesive. Phenol resin solution 18% by weight First inorganic filler A (mainly calcium carbonate powder) 72% by weight Second inorganic filler B (shell fossil powder) 8% by weight Hexamethylenetetramine solution (hardener solution) 2% by weight % A predetermined amount of this phenol resin adhesive was applied to the E26 die by 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 part 4 of the glass bulb 3 of a general light bulb, and 2 parts of the mouthpiece are attached to the mouthpiece heating pot of the automatic mouthpiece bonding machine for light bulbs equipped with a general-purpose mouthpiece heating pot, and the normal heating conditions are set. Then, the adhesive 1 was baked by heating at 220 ° C. for 1 minute to bond the bulb 3 and the base 2.

The composition of the adhesive 1 after baking was about 6.4% by weight of the phenol resin and about 93.6% by weight of the inorganic fillers (A and B).

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 joint after the lighting for 0 hours and 1000 hours was carried out. Japanese Industrial Standards (JI
The strength was 5 N · m or more, which was higher than that of S), 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 the work to be difficult to do and stain the surroundings like pulling out a thread like a candy can. Could be performed without any change from the conventional method.

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 line black dots in the figure are the products of the present invention, and the dotted line x points are the conventional phenol resin adhesives (20 wt% of phenol resin and 70 wt% of calcium carbonate as the inorganic filler (A and B)) for comparison. It consists of and).

The test piece tested for heat resistance has a length of about 10
Prepare two plates made of glass with a size of mm × width of about 20 mm × thickness of about 1 mm, and form an adhesive with a thickness of about 1 mm with an area of about 7 mm in length × about 10 mm in width and bond them together. , About 1
The adhesive was cured by heating at 80 ° C for 15 minutes. Then, put this test piece in a constant temperature bath at 200 ° C.
Five pieces were taken out every 0 hours and pulled in directions opposite to each other in parallel with the adhesive surface to measure the shear strength.

As the test piece tested for ultraviolet resistance, a plate body made of glass having a length of about 10 mm × a width of about 20 mm × a thickness of about 1 mm is prepared, and a plate surface has a length of about 10 mm × width of about 1 mm.
Form an adhesive with an area of 0 mm and a thickness of about 1 mm and adhere it to the surface of the bulb of the tube-shaped germicidal lamp GL15.
The adhesive was cured by heating at 0 ° C for 15 minutes. And
The germicidal lamp GL15 was continuously turned on to forcibly irradiate the adhesive with ultraviolet rays. Then, every 100 hours, a jig having a weight of 500 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. Regarding the ultraviolet resistance, the two hardly changed, and after 500 hours, the product of the present invention was slightly superior.

Further, the elongation property of this adhesive was examined as a test for evaluating the adhesive state.

In this test, 2 g of the adhesive was rolled into a spherical shape, which was placed on a top plate and placed in a thermostat at a temperature of 170 ° C. for 10 minutes.
The diameter is measured after heating for a minute.

As described above, the reason why the product of the present invention is superior to the conventional product is that the first inorganic filler A, calcium carbonate powder, is fine powder and the second inorganic filler B is It is speculated that it was an important point that a part of the shape was a vertically elongated grain (acicular grain). That is, a cross-section of this adhesive 1 layer has a structure as shown in FIG. 4, in which vertically elongated grains (needle-shaped grains) 1L, 1L, ... 1L and the fine powder particles 1S, 1S, ... Surrounding the same are bonded by an action such as bridging through the adhesive main agents 1B, 1B, ..., Increasing the bonding strength between the powder particles. Conjectured to be. In FIG. 4, the shapes of the adhesive main agent 1B and the inorganic fillers 1L and 1S are shown in a circular shape or a rod shape, but in reality, they are irregular shapes, and most of them have a salient corner.

In the above examples, regarding the mixing of the phenolic resin as the adhesive main agent and the calcium carbonate as the inorganic fillers A and B, 1 to 30% by weight of the adhesive main agent and the balance of the inorganic fillers A and B were used. In the adhesive 1, the smaller the size of the first inorganic filler A, the better. When the average particle size as a whole is 147 μm or less, and the fine powder particles having an average particle size of 10 μm or less are 50 to 90% by weight. Most effective. The second inorganic filler B of vertically elongated grains (needle-shaped grains) may have a vertical / horizontal (thickness) ratio of 300% or more, and the second inorganic filler B may be added to the first inorganic filler A. It suffices if the content B is 1 to 20% by weight.

When the average particle size of the first inorganic filler A exceeds 147 μm (100 mesh on US sieve), the fluidity of the adhesive is poor, and the adhesive should be applied evenly when it is applied to the die. It is impossible because it cannot be done.

Further, as for the size of the vertically long particles (needle-like particles) of the second inorganic filler B, if the length ratio of the longest part to the shortest part is less than 300%, the bridging between the powder particles There is no such action, the bond is weak, and the bonding strength is reduced.

Further, as shown in Table 2, it has been found that the bonding strength can be improved by the test piece test or the practical light bulb test, by increasing the mixing ratio of the vertically elongated particles (acicular particles). Further, from Table 2, increasing the proportion of the vertically elongated grains (needle-shaped grains) improves the bonding strength,
If the mixing ratio exceeds 20% by weight, the viscosity is too low, and conversely if the mixing ratio is less than 1% by weight, there is a problem that the adhesive strength does not increase. Also, in the strength test by actual use on a light bulb, the mixing ratio of 1 to 20% by weight was good.

[0031]

[Table 1] The composition ratio of the adhesive 1 after baking is 1 to 30% by weight, preferably 5 to 30% by weight of the adhesive main agent such as phenol resin.
20% by weight, and the balance was the inorganic fillers A and B. The average particle size of the first inorganic filler A is 14
50 to 9 having a particle size of 7 μm or less (100 mesh or less with a US sieve) and preferably having an average particle size of 10 μm or less.
Inorganic filler A containing 0% by weight, and this inorganic filler A
1 to 20% by weight, and preferably 5 to 15% by weight, of the second inorganic filler B having vertically long grains (acicular grains) having the same average particle size as the above and having an aspect ratio of 300% or more. The best 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 adhesive main agent is not limited to the phenol resin, but may be a silicone resin or the like, or a mixture thereof. Further, the curing agent is not limited to hexamethylene tetracine.

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

Further, the adhesive main agent and the inorganic fillers A and B should have the same amount and the same component ratio as above even if the materials are changed.

Furthermore, the inorganic filler B of vertically elongated particles (needle-shaped particles) is not limited to the above-mentioned shell fossil powder, but may be artificially formed.

[0037]

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.

FIG. 4 is a schematic cross-sectional view showing an adhesive layer of the present invention.

[Explanation of symbols]

 1: Adhesive 1B: Adhesive main agent 1S: Inorganic filler A (fine powder particles) 1L: Inorganic filler B (vertically elongated particles (needle particles)) 2: Base 3: Glass bulb 4: Sealing part

Claims (5)

[Claims] 1. A first inorganic filler having an average particle size of 147 μm or less (100 mesh or less with a US sieve) and vertically elongated grains (acicular grains) having a longest length of 300 and a shortest length of 300.
% To 1 to 20 with respect to the first inorganic filler
A base cap adhesive for a tube, comprising a second inorganic filler having a weight% and a resin as an adhesive main agent. 2. The base adhesive for a tube according to claim 1, wherein the resin as an adhesive main agent is at least one of a phenol resin and a silicone resin. 3. The base adhesive for a bulb according to claim 1, wherein the first inorganic filler is at least one of calcium carbonate and silica. 4. A bulb comprising a glass bulb and a die which are adhered to each other via the bulb die adhesive according to any one of claims 1 to 3. 5. The tube according to claim 4, which is a light bulb or a discharge lamp.