JPH05269911A - Laminated film - Google Patents

Abstract

PURPOSE:To prolong the life of an EL lamp without deteriorating various characteristics required in a transparent conductive film for the EL lamp. CONSTITUTION:In a laminated film wherein a transparent membrane having conductivity is laminated to the single surface of a transparent polymeric film and a membrane composed of a cyanoethyl polymer is further formed on the membrane as a topcoat layer, the transparent membrane having conductivity is composed of an oxide layer containing 0.1-5wt.% of Pd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL used for an electrode of an electroluminescence (hereinafter abbreviated as EL) lamp.
The present invention relates to a laminated film that improves the life of a lamp.

[0002]

2. Description of the Related Art Conventionally, as a laminated film for EL lamp electrodes, a transparent conductive layer of tin oxide, indium oxide and a mixture thereof is formed on at least the lower surface of a polyester film, a polyether sulfone film, a polyethylene sheet, etc. In general, Pd is also formed by sputtering or the like, and light is emitted by applying a voltage with a light emitting layer sandwiched between this electrode and a back electrode such as an Al plate. The method of letting is adopted. As a substance used for the light emitting layer, the base Z
A phosphor in which Cu, Mn, etc. are mixed with nS or the like as an activator is fixed with a high dielectric organic material called a binder, for example, a cyanoethyl polymer.

The EL lamp is a solid-state light-emitting body that does not generate heat, has characteristics such as thin and uniform light emission and a high degree of freedom in shape, and is widely used mainly for liquid crystal backlights. It started to come. However, there is a situation in which further improvement in life is desired as compared with other light sources. Causes of shortening the life include blackening of the transparent conductive film layer due to an AC voltage applied during light emission of the EL lamp, uneven light emission due to variations in adhesion between the laminated film and the light emitting layer, and the like.

[0004]

An object of the invention is to improve the life of an EL lamp without deteriorating various characteristics required for a transparent conductive film for an EL lamp.

[0005]

According to the present invention, a transparent polymer film is laminated on one surface with a thin film having transparent conductivity, and a cyanoethyl polymer thin film is formed as a top coat layer on the thin film. The present invention relates to a laminated film, wherein the thin film having transparent conductivity contains 0.1 to 5 wt% of Pd.

As the polymer film used in the present invention, a polymer film having transparency and excellent heat resistance is suitable. Specific examples thereof include polyester resins such as polysulfone, polyether sulfone, and polyethylene terephthalate. An oxide of an alloy of In, Sn, Pd and an oxide of an alloy of In, Pd can be used as the transparent conductive layer of the thin film having transparent conductivity. As a method for applying the conductive film layer to the polymer film, a physical deposition method such as a vacuum vapor deposition method and a sputtering method is generally used, but a chemical deposition method such as a plating method and a vapor phase method may be used. By uniformly dispersing Pd in the transparent conductive layer, without impairing the transparency of the transparent conductive layer,
It has been found that it is possible to prevent blackening of the transparent conductive layer due to an AC voltage applied when the EL lamp emits light and to improve the life of the EL lamp. The concentration of Pd in the transparent conductive layer is required to be 0.1 wt% in order to obtain the blackening prevention effect, and it is possible to obtain a large effect as the concentration is increased. The transparency becomes poor, and its concentration is appropriately 0.1 wt% to 5 wt%.

It is possible to impart these transparent conductive layers to a polymer film, even if a third layer is formed between the polymer film and the transparent conductive layer in order to improve the adhesion thereof. Rather, it is desirable in order to improve the flexibility and processability of the polymer film.

The top coat layer coated on the transparent conductive layer is most preferably a cyanoethyl polymer thin film used as a binder agent for the light emitting layer in order to improve the adhesiveness with the light emitting layer of the EL lamp. As the top coat layer forming method, a coating method using a solvent is generally used,
Dip method, roll coater method, doctor blade method,
Conventional methods such as the spinner method are used. After coating, it is dried and, if necessary, cured to obtain the laminated film of the present invention.

[0009]

【Example】

(Example 1) A weight ratio of In: Sn: on a polyethylene terephthalate film having a thickness of 75 μm was measured by a sputtering method.
An alloy oxide of Pd = 95: 4: 1 was formed into a film having a thickness of 300 angstrom, and cyanoethyl cellulose was used as a top coat layer on the cyanoethyl cellulose by a spinner method.
It was applied to a thickness of μm and dried. The laminated film thus prepared was incorporated into an EL lamp using a zinc sulfide-based phosphor. (Comparative Example 1) A laminated film was prepared in the same manner as in the example except that an alloy oxide containing no Pd component and having a weight ratio of In: Sn = 95: 5 was used. (Comparative Example 2) A laminated film equivalent to that of the example was prepared except that the top coat layer was not provided, and an EL lamp was tried to be prepared in the same manner as described below. Has occurred. For the examples and comparative examples, 100 V in an atmosphere of 50 ° C. and relative humidity,
An AC voltage of 300 Hz was applied and the EL lamp continued to emit light, and the change in brightness was traced to measure the life. Example 1
In the comparative example 1, the half-life time of the luminance was 300 hours, and the transparent conductive layer was not blackened and there was no unevenness of light emission. In Comparative Example 2, the half-life was 100 hours, and the unevenness of light emission became more remarkable.

[0010]

According to the present invention, it is possible to obtain a laminated film which can improve the life of an EL lamp without deteriorating various characteristics required for the EL lamp.

Claims (1)

[Claims] 1. A laminated film in which a transparent conductive thin film is laminated on one surface of a transparent polymer film, and a cyanoethyl polymer thin film is formed as a top coat layer on the thin film, which has transparent conductivity. The thin film is 0.1-
A laminated film comprising 5 wt% of Pd.