JPS58181742A - Formation of diffusion film for bulb - Google Patents

Abstract

PURPOSE:To form a translucent diffusion film having rock slit pattern, by coating a soln. of ethylcellulose in n-propyl alcohol or butyl acetate on the inside of a transparent glass globe and by drying the soln. CONSTITUTION:A soln. prepared by dissolving 0.5kg ethylcellulose of high viscosity in 10l medium b.p. solvent such as butyl acetate or n-propyl alcohol is coated on the inside of a transparent plastic globe for an electric current type fluorescent lamp. The soln. is dried with hot air adjusted to 50-70 deg.C and 5- 8m/sec speed. The coated film shrinks, and adiffusion film having rock slit pattern can be formed. The diffusion film has superior adhesive strength and is not discolored even after long-time lighting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a translucent diffusion film on a transparent glass globe.

In recent years, resource-saving measures have attracted attention as a social issue, and the development of energy-saving light sources is desired in the lighting field. A compact light bulb-shaped fluorescent lamp device was developed.

The globe of this bulb-shaped fluorescent lamp device is made of transparent plastic molded and processed with various patterns on the surface of the globe to increase the refraction and diffusion of light. Due to the effects of near ultraviolet rays emitted from fluorescent lamps and the temperature rise of the ballast built into the device,
There are drawbacks such as the gloves tend to deteriorate and become colored and the brightness decreases.

There are also products that use a transparent glass globe and have a white diffusion film formed on its inner surface, but in this case, the globe will not deteriorate or become discolored due to near ultraviolet rays or temperature rises in the ballast, but the brightness will be reduced. There are drawbacks.

As a result of investigating various ways to easily and inexpensively solve the drawback of reduced brightness due to the formation of a white diffusion film on a transparent glass globe, the inventors discovered that n- Propyl alcohol or n-
By applying a solution of high viscosity ethyl cellulose in butyl acetate and drying it by blowing hot air into the glass globe, the coating film shrinks and a diffusion film with a translucent rock pattern is formed. It's a headline that can be formed.

Here, the reason why the diffusion film appears opaque is that the ethyl cellulose applied to the inner surface of the glass bulb forms a film with uneven thickness and uneven thickness.

In this film, countless fine uneven patterns can be seen. In the present invention, this is referred to as a whistle pattern.

The ethyl cellulose used to form this film has an ethoxyl group content of 475 to 490. It is a high viscosity type with a viscosity of 360 to 450°p8 in a 2% solution, with no deterioration due to near ultraviolet rays, strong adhesion to glass, and no peeling of the coating due to moisture adsorption. I have everything.

Since the drying rate of the ethyl cellulose solution used for coating is related to the refractive index of the coating film, the optimal solvent is butyl acetate or n-propyl alcohol, which are medium boiling point solvents among organic solvents that dissolve ethyl cellulose.

If a low boiling point solvent (methyl alcohol, acetone, ethyl acetate, etc.) is used, pinholes will form in the coating film, and as the drying conditions change, a cloudy phenomenon will appear and the adhesion strength of the coating film will weaken.

In addition, when high boiling point solvents (butyl alcohol, amyl acetate, ethyl lactate, etc.) are used, the drying rate of the coating film decreases,
Since the coating film does not shrink during drying and becomes a smooth transparent coating film, it is not possible to obtain a textured pattern.

When using butyl acetate or n-propyl alcohol, which are medium boiling point solvents, the drying hot air conditions are:
The optimum temperature is 70°C and wind speed of 5 to 8 m/7 seconds.

If the temperature is outside the above range, drying will be extremely slow.
In both cases, the phenomenon of shrinkage of the film surface did not occur because it was too early.1. Turtles and bubbles may occur, or a smooth coating film will result, making it impossible to obtain a translucent diffusion film with a high refractive index.

Examples and reference examples of the present invention will be described below.

Example 1 Solubility of n-butyl acetate 10 ml high viscosity ethyl cellulose ocs Kp is applied to the inner surface of a cylindrical transparent glass globe. Inside this glass globe, the temperature is 60-70℃ and the wind speed is 6-s mAp.
Dry the solution by blowing hot air. Drying starts from the top of the glass globe, and only the surface of the ethyl cellulose solution that is exposed to the warm air becomes hard, and the drying state between the inner and outer surfaces becomes uneven, causing the flow of the inner surface of the coating film to become uneven. As it dries while being held down, cracks,
Shrinkage occurs, forming a translucent paint film with a good diffusion effect.

A 13 watt double U-shaped fluorescent lamp was assembled in this glass globe together with a ballast and a lighting tube to produce a light bulb type fluorescent lamp device.

Even after 6000 hours of lighting, there was no discoloration or peeling of the paint film.
In addition, we were able to obtain a glass globe that was brighter than conventional products that had a white film coated on its inner surface. - Example 2 n-propyl alcohol 10! A solution of high viscosity ethyl cellulose o s Kp is applied to the inner surface of a spherical transparent glass globe. The dissolved solution is dried by blowing warm air at a temperature of 50 to 60° C. and a wind speed of 6 to 6 msa into the glass globe.

A coating film having a similar pattern to that of Example 1 was obtained.

A 13 watt double U-shaped fluorescent lamp was incorporated into this globe along with a ballast and a lighting tube to produce a light bulb type fluorescent lamp device.

Even after lighting for eooo hours, there is no coloring or peeling of the paint film.
It was still possible to obtain a glass globe that was 6 to 8 percent brighter than a conventional product in which a white film was applied to the inner surface of the globe.

Reference Example A solution of butyl alcohol type 10 high viscosity ethyl cellulose o s Ky is applied to the inner surface of a spherical transparent glass globe. The dissolved liquid is dried by blowing warm air at a temperature of 60 to 7QC and a wind speed of 6 to sm for 7 seconds into this glass globe.

Due to the high boiling point of butyl alcohol, the drying speed of the head of the glass glove was slowed down, and the viscosity of the binder in the paint film decreased, resulting in a thinner paint film, no shrinkage, and a transparent film.

As explained below, the present invention is an inexpensive and simple method for molding glass globes without the need to create a mold with a special pattern, and has a high adhesion strength and does not discolor even when lit for long periods of time. It is possible to provide a method for forming a diffusion film on the inner surface of a transparent glass globe.

Claims (1)

[Claims] Ethyl cellulose mineral is added to the inner surface of the transparent glass globe.
- Applying a solution dissolved in propyl alcohol or butyl acetate, drying the solution by blowing hot air into the glass globe, and forming a diffusion film having a translucent pattern on the inner surface of the glass globe. A method for forming a diffusion film for a tube, characterized by: