JPS58155620A - Formation of white diffusion film for tube bulb - Google Patents

Abstract

PURPOSE:To obtain an uniform film surface having large film adhesion intensity and excellent optical diffusibility by making a diffusion film to be formed on the inner surface of a glass globe while using suspension wherein silicon oil denatured by an amino-base and white pigment dispersed in isopropanol as an isopropanol solvent. CONSTITUTION:Silicon oil denatured by titanium amino oxide and isopropanol are put in a pot for ball mill to be cracked and mixed for 5hr. The inner surface of a long cylinder-shaped transparent glass globe is applied with the suspension mixed in this way. This is dried by blasting heated wind having an anemoquantity of about 200ml/sec at 40 deg.C in the globe. A 9watt type U-shaped fluorescent lamp together with a stabilizer and a lighting tube is incorporated in the globe obtained in this way thus to make a bulb type fluorescent lamp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a white diffusion film for a light bulb, and more particularly to a method for forming a white diffusion film for a light bulb type fluorescent lamp having a bulb base and incorporating a non-linear fluorescent rung together with a ballast 1 lighting tube. The present invention relates to a method for forming a white diffusion film on the inner surface of an outer globe.

BACKGROUND ART Fluorescent lamps have traditionally been used in large quantities not only in factories and shops but also in homes in Japan due to their significantly higher lamp efficiency than incandescent light bulbs. However,
Most fluorescent lamps are linear or annular in shape, and are larger than light bulbs.Furthermore, they require a ballast and lighting tube, making the entire device large and difficult to handle. Their major drawback is that they are more complicated than light bulbs.

In recent years, in order to solve these drawbacks, so-called light bulb-shaped fluorescent lamps have been developed, which are formed into a U-shape or double U-shape, integrated with a lighting tube and ballast, and housed in a glass globe. Some suggestions have been made. In this case, the inner surface of the globe is coated with white pigment to evenly diffuse the light from the built-in fluorescent lamp, but this white pigment application method has traditionally been used for incandescent light bulbs. Two methods are known: an electrostatic coating method using fine silica powder, and a wet coating method using a suspension of white pigment dispersed in an organic solvent containing a binder such as nitrified cotton, which is used in fluorescent lamps. ing.

In compact fluorescent lamps, since air is present inside the globe without being exhausted, the moisture contained therein adheres to the inner surface of the globe during lighting, and this causes
For example, it has been found that if the adhesive strength is weak, such as fine silica powder applied to the inner surface of the glove using the Seiden coating method, a part of the film may fall off. On the other hand, with the wet coating method using a suspension using nitrified cotton as a binder, when the light is turned on for a long time, the entire diffusion film turns yellow due to the ultraviolet rays emitted from the fluorescent lamp housed inside the glove. It was discovered that the appearance was impaired due to discoloration, and the luminous flux was greatly reduced.

The present invention provides a novel method for forming a white diffusion film for bulbs, which does not cause any film shedding and does not change color even after being turned on for a long time, by using the latter of the two coating methods, the wet coating method. It is.

When using a wet coating method, important factors include selecting a solvent with good pigment dispersibility, selecting a stable binder that will not change color even when exposed to ultraviolet rays for a long time, and having a high film adhesion strength.

The inventors conducted experiments on various binders and found that silicone resin was suitable. Among silicone resins, silicone varnishes have been used in large quantities for paints.

However, most of the solvents used in silicone varnishes contain benzene groups such as toluene and xylene, which are extremely harmful to the human body and require expensive equipment to remove. I have a problem. After investigating easy-to-use products other than silicone varnish, we discovered that silicone oil modified with amine groups is soluble in alcohol. Alcohol has the advantage that it is not as toxic as toluene, xylene, etc., and therefore only requires a ventilation device. Among alcohols, methanol and ethanol have low boiling points, so they evaporate quickly, making it extremely difficult to set drying conditions, making it difficult to obtain a homogeneous film surface, and due to their low flash points, great care must be taken when handling them. It was discovered that Improper Tool has a relatively high boiling point, which makes it easy to set drying conditions, and it also has excellent pigment dispersibility. It was. It has been found that butanol and alcohols with higher molecular weights are unsuitable because both have high boiling points, require an extremely long time to dry, and do not provide a homogeneous film surface.

As described above, as a result of forming a diffusion film on the inner surface of a glass glove using Improper Tool as a solvent and a suspension in which white pigment was dispersed together with silicone oil modified with amine groups, the film adhesion strength was extremely high. It has been found that a large, homogeneous film surface with excellent light diffusivity can be easily obtained. As a result of actually applying it to a self-ballasted fluorescent lamp, it was found that there was no discoloration at all even after it was lit for more than 6,000 hours.

Examples of the present invention will be described in detail below.

Example 1 Titanium oxide...3 K9
Amino modified silicone Hibiki oil...450
jF isoglopanol ・・・3.6
2 The above materials were placed in a ball mill pot and subjected to ball milling for 5 hours. The prepared suspension was applied for 1.5 y to the inner surface of a long cylindrical transparent glass globe with an inner diameter of 7.5 Ql+ and a length of 121 mm. Dry at about 40″C
The test was carried out by blowing warm air into the glove at a flow rate of approximately 200 ml/sec. A 9-watt U-shaped fluorescent lamp was assembled into a globe along with a ballast and a lighting tube to produce a light bulb-shaped fluorescent lamp.

Even when this lamp was lit for 6,000 hours, no film was observed to come off, and no coloration occurred.

Example 2 Calcium phosphate...4 Kp
Ruminated silicone oil eooy isopropanol 2.8°C The above materials were thoroughly mixed and stirred and then passed through a 300 mesh sieve to prepare a suspension. Using the prepared suspension, 1.8 coats were applied to the inner surface of a spherical transparent glass globe with an inner diameter of 1 ocIn.

Drying was carried out by blowing warm air into the glove at a rate of about 40° C. and a flow rate of about 300 m for 127 seconds. A 10 watt double U-shaped fluorescent lamp was incorporated into the globe along with a ballast and a lighting tube to produce a light bulb-shaped fluorescent lamp.

Even when this lamp was turned on for eooo hours, no film came off at all, and no discoloration was observed.

Example 3 Barium carbonate...4 Kg
Amino-modified silicone φ oil・・・・・・-800
F Ingropanol...3.0!
Ball milling was performed for 6 hours even when the above materials were placed in a ball mill pot. After ball milling, the inner diameter is 10 cm.
2.0y was applied to the inner surface of a short cylindrical transparent glass globe with a height of 9.5cfn. Drying is approximately 60″C9 air volume approximately 30
The test was carried out by blowing warm air into the glove at a rate of 0 ml/sec.

Next, a 10 watt double U-shaped fluorescent lamp was installed in the globe along with a ballast and a lighting tube to produce a light bulb-shaped fluorescent lamp.

Even when this lamp was lit for 6,000 hours, no film came off at all, and no coloration was observed.

As explained above, the present invention can provide a new method for forming a white diffusion film on the inner surface of a glove, which has particularly high adhesion strength and does not discolor. The effect is extremely large.

It should be noted that the present invention is not limited to only the self-ballasted fluorescent lamp as described above, but can of course be applied to the formation of a white diffusion film inside a globe for a general light bulb or a globe for a high-pressure discharge lamp.

Claims (1)

[Claims] A method for forming a white diffusion film for a tube, which comprises forming a white diffusion film on the inner surface of a glass globe using a suspension of a white pigment dispersed in isopropanol together with a silicone oil modified with an amine group.