JPH0320956A - Ultraviolet ray suppressing fluorescent lamp and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a fluorescent lamp suppressing ultraviolet ray radiation by coating a paint containing the fine powder of zinc oxide, a binder and a solvent on the inner surface of a glass tubular bulb, and heating it at 60-500 deg.C. CONSTITUTION:25-250 pts.wt. of zinc oxide with the grain size 0.1mum or below as a ultraviolet ray absorbent is combined with 100 pts.wt. of a binder made of soda silicate or the like, and the mixture is coated on the inner face of a glass tubular bulb with xylene or the like as a solvent. It is heated at 60-500 deg.C to form a uniform film with the thickness 1-15mum. This film exerts excellent ultraviolet ray absorbing ability and has no adverse effect on the light color and color rendering property of a light emitting source, and a fluorescent lamp has a high light flux and good light color and color rendering property.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a fluorescent lamp with suppressed ultraviolet radiation and a method for manufacturing the same.

``Prior Art'' Some Rising Light sources, such as those used in department stores, museums, museums, etc., require careful attention to the color contrast of products and exhibits. As such an illumination light source, a fluorescent lamp (NU) as described below has conventionally been used to prevent color fading.

This NU lamp has titanium oxide (
This film is made up of two layers: a film containing titanium oxide and a binder, and a film containing a phosphor and a binder. It is designed to absorb ultraviolet rays of 400 nm or less.

``Problems to be Solved by the Invention'' However, the NU lamp has the following drawbacks compared to similar lamps that do not have a titanium oxide-containing film.

■ In order to have sufficient ultraviolet absorption ability, the film containing titanium oxide must be thickened to increase the content of titanium oxide, but in this case, the thick film reduces the luminous flux of the NU lamp. 5~1 more than the luminous flux of a normal lamp
It decreases by about 0%.

■ Titanium oxide absorbs ultraviolet and blue light, so N
The light and color of the U lamp will be different from that of a normal lamp.

(2) In relation to (2), the color rendering properties of NO lamps are degraded.

■ In this NU lamp, in order to form the aforementioned two-layered film, a high-temperature process of approximately 600°C must be performed twice, making the manufacturing process complicated, and furthermore, The strength of the glass tube decreases.

The present invention has been made to solve the above problems, and its purpose is to have a high ultraviolet ray suppressing effect, high luminous flux, good light color and color rendering, and easy manufacturing. An object of the present invention is to provide an ultraviolet suppressing fluorescent lamp and a method for manufacturing the same.

``Means for Solving the Problems'' In the ultraviolet suppressing fluorescent lamp according to claim 1 of the present invention, a coating containing fine powder of zinc oxide and a binder is applied to the inner surface of the glass bulb constituting the light emitting source. This was used as a means of solving the second problem.

In the method for producing an ultraviolet suppressing fluorescent lamp according to claim 2, the inner surface of a glass bulb constituting a light emitting source is coated with a coating agent containing fine powder of zinc oxide, a binder, and a solvent; The solution to the second problem was to heat the product to 60-500°C.

The present invention will be explained in detail below.

Fluorescence described in 3q requirement l in the present invention. The lamp has a transparent coating formed on the inner surface of the glass bulb, which consists of fine zinc oxide powder and a binder. Here, the fine powder of zinc oxide used to form the film acts as an ultraviolet absorber. It is desirable that the diameter of this fine powder be 0.1 μl or less, and if the particle i% exceeds 0.1 μl, the ultraviolet absorption ability and visible light transmittance will decrease, which is undesirable.

Further, as the binder, one having the following properties is used. In other words, it is resistant to deterioration by ultraviolet rays, transmits visible light well, has good adhesion to glass tubes, mold strength, film forming properties, and drying properties, and does not require a degreasing process, and after curing. , no release of organic matter or moisture in vacuum, etc. Binders with such properties include alkali silicates such as sodium silicate, inorganic colloids such as silica sol and alumina sol, alkyl silicates such as tetraethoxinlan, phosphates such as aluminum phosphate, and metal alkoxides. , aluminum chelate, and organometallic compounds such as tin acetate.

By using such a binder, the following advantages can be obtained.

In conventional NO lamps, when manufacturing them, T i
Since the O* powder was kneaded with a binder such as ethyl cellulose, polyvinyl alcohol, or polyacrylic acid and then applied in the form of a slurry, a degreasing process to decompose and remove these binders is essential. In this case, if the degreasing is insufficient, undecomposed organic matter will remain inside the fluorescent lamp, which may shorten the life of the fluorescent lamp or reduce its brightness. was. However, by using the above-mentioned inorganic or organic metal binder, the delucidation step becomes unnecessary and baking can be performed at low temperatures and in a short time.

Further, the blending ratio of the above-mentioned zinc oxide fine powder (ultraviolet absorber) and binder is usually 10 to 900 parts by weight of the fine powder to 100 parts by weight of the binder, more preferably 25 to 900 parts by weight.
The range is set at 250 parts by weight. This is because if the amount of fine powder is less than the above range, sufficient ultraviolet absorption ability cannot be obtained and the thickness of the film must be increased.On the other hand, if the amount of fine powder is greater than the above range, The attachment of the arytenoid to the bulb becomes weaker, and the strength of the arytenoid decreases,
This is because the transmittance of visible light further decreases.

In addition, the thickness of a film obtained using such zinc oxide fine powder and a binder as its constituent components is usually 0.
．． The amount is in the range of 1 to 100 μR, preferably 0.5 to 30 μl, and more preferably 1 to 15 μl. This is because if the thickness of the arytenoid is thinner than 0.1 μm, its ultraviolet absorption ability decreases and pinholes are likely to occur in the arytenoid. Conversely, if the arytenoid is thicker than 100 μl, This is because the visible light transmittance decreases and the adhesion of the arytenoid to the glass bulb is impaired.

Next, an example of the manufacturing method of the ultraviolet suppressing fluorescent lamp according to claim 2 of the present invention will be explained.

First, prepare the coating agent listed below.

The coating agent used in the present invention contains the above-mentioned fine powder, binder, and solvent as main components. The solvent constituting this coating agent may be any solvent as long as it dissolves the binder. This solvent has a boiling point of 60 to 200 to enable drying at low temperatures.
℃ is desirable. Such solvents include aromatic hydrocarbons such as quinolene, l.luene, etc. Alcohols such as n-butanol. Esters such as butyl acetate. Ketones such as methyl isobutyl ketone. Glycol ethers such as ethyl cellosolve, n-hexane,
Examples include saturated hydrocarbons such as ligroin and mineral spirits.

The coating agent used in the present invention includes, in addition to zinc oxide fine powder, a binder, and a solvent, a trace amount of a surface treatment agent,
Of course, a dispersant, a lubricant, a desiccant, an antifoaming agent, a whipping agent, etc. may be added as appropriate.

Next, apply the coating agent to the inner surface of the glass tube, and
By heating to ~500°C, the solvent is evaporated and dried, and a hardening process such as baking is performed.

Next, a fluorescent lamp is manufactured by a conventional method such as forming a membrane containing a phosphor, attaching electrodes, and filling the membrane with gas.

As for the method of applying the coating agent, any method may be used as long as it is possible to uniformly apply the coating agent to the inner surface of the glass tube. Examples include a brush coating method, a tumble coating method, a spray method, a dipping method, a flow coating method, and the like. In addition, since the viscosity of the coating agent differs depending on the coating method, the viscosity of the coating agent is adjusted by using a suitable amount of solvent.

In the fluorescent lamp of the present invention, a coating containing fine powder of zinc oxide that acts as an ultraviolet absorber is formed on the inner surface of the glass bulb, so this coating exhibits good ultraviolet absorption ability, Therefore, radiation of ultraviolet rays can be sufficiently suppressed. Furthermore, if the particle size of the fine zinc oxide powder constituting the film is 0.1 μl or less, the film can be made very thin, and the fine powder has a visible light wavelength of 0.4 μR to 0.
．． Since it is sufficiently smaller than 8 μR and has a refractive index of 1.9, which is relatively small, visible light can be transmitted for f minutes without being absorbed or scattered, thereby suppressing a decrease in the luminous flux of the light emitting source. be able to.

In addition, by forming the film, the light color and color rendering of the light emitting source are less affected, and since the film is thinner, the material cost required to form the film is lower. .

In addition, in the method for manufacturing a fluorescent lamp of the present invention, since the film is formed using a coating agent containing zinc oxide fine powder, a binder, and a solvent, a maturing treatment is performed at about the volatilization temperature of the solvent. Therefore, the baking temperature can be kept low compared to the case where a film containing titanium oxide is formed on the inner surface of the glass bulb. Furthermore, since the baking temperature can be kept low, deterioration in the strength of the glass tube can be prevented.

"Examples" The present invention will be described in more detail below with reference to Examples.

100 parts by weight of tetraethoxysilane, IOOffi parts of isopropyl alcohol, O. 35 parts by weight of IN hydrochloric acid were combined and reacted at 60°C with stirring for 2 hours to hydrolyze tetraethquinsilane, and then 245 parts by weight of isopropyl alcohol was added to quench the hydrolysis of tetraethquinsilane. This was used as a binder solution. 10 parts by weight of ultrafine zinc oxide having a particle size of 0.01 μl were added to 10 parts by weight of this binder melt aloo, and
A coating agent was prepared by dispersing for 0 hours.

This coating agent was poured onto the inner surface of a glass bulb of a fluorescent lamp and dried at 200° C. for 10 minutes to form a transparent film with a thickness of 2 μl.

Next, a film containing a phosphor was formed, electrodes were attached, and gas was filled in to manufacture a lamp according to a conventional method.

In addition, in order to compare with this fluorescent lamp, a fluorescent lamp without a coating formed on the inner surface of the glass bulb (Comparative Example I)
and a fluorescent lamp (Comparative Example 2) in which two layers, a titanium oxide layer and a phosphor layer, were sequentially formed on the inner surface of a glass bulb were used.

The characteristics of the fluorescent lamps of the above Examples and Comparative Examples 1 and 2 were investigated, and the results are shown in Table 1. In Table 1, Ra is the average color rendering index, and UV is the amount of ultraviolet radiation.

To measure the amount of ultraviolet radiation, use an ultraviolet intensity meter (UV
R-365, manufactured by Tokyo Optical Co., Ltd.), and the distance between the lamp and the light receiving section was set to 30 cx. Furthermore, the symbol - in the UV column in Table 1 indicates that no ultraviolet light was detected by the ultraviolet intensity meter.

In addition, the spectral energy distribution concave line of the fluorescent lamp of the example was investigated, and the spectral energy distribution lII of the fluorescent lamp obtained was
The I line is shown in FIG. For comparison, the spectral energy distribution dl line of ratio example 1 is shown in FIG. 2, and the spectral energy distribution curve of comparative example 2 is shown in FIG. 3.

As is clear from Table 1 below, it was confirmed that the total luminous flux of the fluorescent lamp of the example was almost equal to that of the fluorescent lamp without a coating (Comparative Example 1). Further, from a comparison between FIG. 1 and FIG. 2, it was found that the fluorescent lamp of the example can sufficiently suppress ultraviolet rays. It should be noted that there was almost no difference in light color between the fluorescent lamp of Example and the fluorescent lamp of Comparative Example 1. In addition, the fluorescent lamp of the example is
Compared to the fluorescent lamp (Comparative Example 2) in which a titanium oxide layer was formed on the inner surface of the glass bulb, the total luminous flux was significantly improved.

"Effects of the Invention" As explained above, the fluorescent lamp according to claim 1 of the present invention has a coating containing fine powder of zinc oxide that acts as an ultraviolet absorber formed on the inner surface of the glass bulb. Therefore, this coating exhibits good ultraviolet absorption ability, and therefore sufficiently suppresses ultraviolet radiation. In addition, there is no adverse effect on the light color and color rendering properties of the light emitting source due to the appearance of the coating, and the light emitting source has a high luminous flux and exhibits good light color and color rendering properties.

Further, in the method for manufacturing a fluorescent lamp according to claim 2,
Since the film is formed using a coating agent consisting of zinc oxide fine powder, a binder, and a solvent, the film can be formed by heat treatment at about the volatilization temperature of the solvent, which makes it possible to form the film using a heat treatment that is at about the volatilization temperature of the solvent. In comparison, the baking temperature can be kept low, thus preventing deterioration in the strength of the glass tube. Furthermore, manufacturing is easier than in the past, and manufacturing costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a graph showing the spectral energy distribution lh line of one embodiment of the ultraviolet suppressing fluorescent lamp according to the present invention, and FIGS. 2 and 3 are graphs showing the spectral energy distribution dlt line of a conventional fluorescent lamp. be.

Claims (2)

[Claims] (1) An ultraviolet-suppressing fluorescent lamp characterized in that a coating containing zinc oxide fine powder and a binder is formed on the inner surface of a glass bulb constituting a light emitting source. (2) Ultraviolet rays characterized by applying a coating agent containing fine powder of zinc oxide, a binder, and a solvent to the inner surface of the glass tube constituting the light source and heating it to 60 to 500°C. Method of manufacturing suppressed fluorescent lamps.