JPH03171548A - Scattering preventing type fluorescent lamp - Google Patents

Abstract

PURPOSE:To form a scattering preventive membrane easily and to improve the scattering preventive effect by forming plural layers of transparent membranes which consist of high polymer resins with different expansion rates on the outer surface of a glass tube. CONSTITUTION:On the outer surface of a glass tube 1, a transparent membrane 2 which consists of a high polymer resin with the expansion rate 200% or more, and a transparent membrane 3 which consists of a high polymer resin with the expansion rate less than 150% are formed in order. By such a constitution, the formation of a scattering protective membranes to the glass tube 1 is made easier, and the scattering preventive effect to a surface shock and to a spot shock can be obtained. The scattering preventive effect can be increased, consequently.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a novel shatterproof fluorescent lamp.

Since conventional fluorescent lamps use glass tubes, if the glass tubes are damaged due to improper handling, glass fragments may fly off and cause personal injury. As a method for dealing with this problem, a shatterproof type fluorescent lamp is known in which the outer surface of a glass tube is covered with a transparent tube made of a polymer resin such as polyester resin. This is a method in which a glass tube is covered with a heat-shrinkable polyester resin tube, and then the tube is heated to form a polymer resin coating on the outer surface of the glass tube.

Problems to be Solved by the Invention In conventional shatterproof fluorescent lamps, tubes made of polyester resin are used in consideration of weather resistance, film strength, etc., as described above.

However, this tube is extremely expensive due to the difficulty of processing it, and the process of manually covering the completed fluorescent lamp with the tube is extremely inefficient.For this reason, shatterproof fluorescent lamps are not commonly used. There was a problem in that they were extremely expensive compared to shaped fluorescent lamps.

In addition, in the drop strength test, since the impact is a surface impact, the contact area of the impact against the fluorescent lamp is large, while in the impact resistance test, the impact area is small against the fluorescent lamp because it is a point impact, but When a molecular resin coating is used alone, there is a large difference in the anti-scattering strength between the drop strength test and the impact test, resulting in a problem that the anti-scattering effect is weakened.

The present invention was made to solve the above-mentioned problems, and it is easier to form a film than before and has better workability.
The present invention provides an anti-scattering fluorescent lamp which prevents deterioration of the anti-scattering polymer resin and has excellent anti-scattering effects against different impacts.

Means for Solving the Problems In order to achieve this object, the shatterproof fluorescent lamp of the present invention includes a transparent coating made of a polymer resin with an elongation rate of 200% or more, and a elongation rate of 150% or less, on the outer surface of the glass tube. It has a structure in which transparent coatings made of polymer resin are successively formed.

According to the present invention, by forming a transparent coating made of a large, soft polymeric resin with an elongation rate of 200% or more on the outer surface of the glass tube, the glass tube can withstand surface impact. Furthermore, by forming thereon a transparent film made of a small, hard polymer resin with an elongation rate of 150% or less, it can withstand point impacts.

Example As a first step, the inventors fabricated shatterproof fluorescent lamps using transparent coatings made of polyurethane resin with different elongation rates on the outer surface of glass tubes, and conducted the following drop strength test. Table 1 shows the results of conducting an impact test and checking the state of scattering of glass pieces.

(Left below) Table 1 However, in the table, ○: Good △: Fairly bad ×: Bad As is clear from Table 1, the larger the impact contact area, the more elastic the polymer resin coating becomes. It is clear that the higher and softer the elongation is, 200% or more, the better; on the other hand, the smaller the impact contact area, the better; conversely, the less elastic the polymer resin coating is, the better the elongation is 150% or less. It became.

Based on the above results, the inventors conducted the following experiment.

As shown in FIG. 1, a polyurethane aqueous dispersion (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.:
After immersing the fluorescent lamp held horizontally in 1500g of liquid (Superflex), it was pulled out and dried with warm air at a temperature of 100℃ and a wind speed of 5m/sec to obtain a tube with an elongation rate of 150 to 800%. A transparent film 2 made of polyurethane resin is formed to a thickness of 60 μm. Next, as a second layer, the fluorescent lamp held horizontally was immersed in a solution containing 1500 gr of polyurethane aqueous dispersion, and then pulled up and dried with warm air at a temperature of 100°C and a wind speed of 5 m/sec to allow elongation. A shatterproof fluorescent lamp was obtained by forming a transparent coating 3 made of polyurethane resin having a polyurethane resin of 150 to 200% in thickness to a thickness of 40 μm. In addition, in FIG. 1, 4 indicates a phosphor coating.

Using the fluorescent lamp obtained in this way, a drop strength test was conducted in which the fluorescent lamp was held horizontally and dropped naturally from a height of 3 m, and a 200 gr steel ball was attached to the end of a 1 m long string. Table 2 shows the results of an impact test in which the sample was exposed to a fluorescent lamp at an angle of 30 degrees from the vertical line.

(Margins below) Table 2 However, in the table, ○: Good △: Fairly bad ×: Bad As is clear from Table 2, the outer surface of the glass tube is coated with a large soft polyurethane resin with an elongation rate of 200 percent or more. By adopting a two-layer structure in which a transparent film is formed, and a transparent film made of a small, hard polyurethane resin with an elongation rate of 150% or less is formed on top of the film, drop strength tests have shown that glass tubes Although the glass was damaged, the coating was not damaged, and the glass pieces were firmly attached to the coating, so the glass pieces were protected by the coating and did not fly out at all. Next, the coating was not damaged at all in the impact test.

Furthermore, when the lamp was lit for 5,000 hours as a life test, the fluorescent lamp according to the present invention did not turn yellow and was found to have no problems.

As described above, according to the present invention, a transparent coating 2 made of a large and soft polyurethane resin having an elongation rate of 200% or more is formed on the outer surface of the glass tube 1, and further, on the coating 2, an elongation rate of 150% is formed. It has a two-layer structure forming a transparent coating 3 made of a small and hard polyurethane resin as shown below, and can significantly reduce the cost to 1/2 or less compared to conventional products.

Effects of the Invention As explained above, the present invention forms a transparent coating made of a polymer resin with an elongation rate of 200% or more on the outer surface of a glass tube, and further coats a small, hard film with an elongation rate of 150% or less. By forming a transparent film made of polymer, it is much easier to form a shatterproof film on the glass tube than before, and the material cost is also low, so the lamp cost can be significantly reduced compared to before. Therefore, it is possible to provide a shatterproof type fluorescent lamp which can reduce the amount of dust and has a large shatterproof effect.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a shatterproof fluorescent lamp according to an embodiment of the present invention. 1...Glass tube, 2...Transparent coating made of 200% or more soft polymer resin, 3...
...Transparent film made of hard polymer resin of 150% or less, 4... Phosphor film.

Claims (1)

[Claims] A transparent coating made of a polymer resin with an elongation rate of 200% or more is formed on the outer surface of the glass tube, and a transparent coating made of a polymer resin with an elongation rate of 150% or less is further formed on the transparent coating. A shatterproof fluorescent lamp that is characterized by: