JP2501066B2 - Polychlorotrifluoroethylene film and its use - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to polychlorotrifluoroethylene (hereinafter referred to as PCT) which can be used for moisture prevention and the like.
A film, referred to as FE), a laminate using the film, or an electroluminescence device (hereinafter referred to as an EL device).

[0002]

2. Description of the Related Art Moisture-proof film made of PCTFE
As described in JP-A-7-128798,
It is useful as a covering material for elements, and is also used for covering and sealing electric parts, electronic parts, medical materials, chemicals and the like.

This PCTFE film is a heat-meltable resin and is obtained by melt molding. For example, PCTF
It can be produced by a method of extruding into a film at a temperature about 100 ° C. higher than the melting point of E (about 210 to 220 ° C.) and then quenching.

[0004]

By the way, this PCT
When the FE film is used for coating an EL element or the like,
Usually, a hot-melt adhesive layer is provided on one side by heating, but at this time, the film surface has to be subjected to an adhesion treatment such as a sputter etching treatment or a corona treatment.

Of course, it is conceivable to provide the hot melt adhesive layer without performing the adhesive treatment, but in this case, the temperature at the time of molding the adhesive layer must be about 190 ° C. or higher. The operation at high temperature increases the crystallinity of the PCTFE film and makes it brittle, and cracks easily occur due to stress stress, which is not practical.

Further, the PCTFE obtained by the above melt molding
The film may decompose during molding and may contain a decomposed gas. When the hot melt adhesive layer forming component is superposed on the surface of the PCTFE film containing the decomposed gas and heated and pressed, the decomposed gas is released and the film itself and the hot melt adhesive layer are foamed to reduce its value. It was sometimes lost.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive research to solve the above problems of the prior art, the present inventor has obtained a PCTFE film having a specific physical property value equal to or less than a specific value. The inventors have found what can be achieved and completed the present invention.

That is, the PCTFE film according to the present invention has an infrared absorbance (A) at 1783 cm ⁻¹ and 227
Ratio with infrared absorbance (B) at 6 cm ^-1 , (A) /
(B) is 0.35 or less.

In the infrared absorption spectrum of the PCTFE film, the peak at 1783 cm ^-1 is -CF = CF ₂
While the peak at 2276 cm ⁻¹ is −
CF ₂ - are recognized to be due. And 178
The ratio of the absorbance of 3 cm ^-1 (A) and the absorbance of 2273 cm ^-1 (B), i.e., (A) / (B) is the molecular terminal abundance,
In other words, it can be considered as a measure of deterioration. However, as in the present invention, 1783c of PCTFE film
The ratio of the infrared absorbance (A) at m ^{−1 and} the infrared absorbance (B) at 2276 cm ⁻¹ , (A) / (B), is 0.
It is not yet clarified why it is not brittle and does not generate decomposition gas when it is 35 or less, but its effect has been confirmed as shown in Examples described later.

The PCTFE film according to the present invention also has an unexpected effect that an adhesive layer can be easily provided on the surface of the PCTFE film without any special adhesion treatment. On the other hand, in the PCTFE film obtained by the above-mentioned conventional melt molding method, the adhesive force of the adhesive layer is weak unless the surface is previously subjected to an adhesive treatment such as a corona discharge treatment or a sputter etching treatment. When it is used for coating such as, there arises such a disadvantage that moisture permeates from the interface between the film and the adhesive layer to shorten the life of the device.

The novel PCTFE film according to the present invention can be obtained by a method completely different from the conventional melt molding method. For example, it can be obtained by a method of pressing the PCTFE powder or pellets with a hot press to form a film. At this time, the temperature is 280 ° C or lower, and the pressure is about 10
˜150 kg / cm ² , and heating / pressurizing time is about 1 to 10 minutes. Further, after casting a dispersion having a PCTFE concentration of about 30 to 60% by weight on a heat resistant substrate such as a metal,
It can also be obtained by heating (the temperature is 280 ° C. or lower) to remove the solvent, baking PCTFE, and then peeling it from the surface of the base material (casting and heating may be repeated if necessary). .

PCTF obtained by such a method
E film is the absorbance at 1783 cm ^-1 (A)
And the ratio of absorbance (B) at 2276 cm ^-1 , (A)
/ (B) is 0.35 or less. On the other hand, the film obtained by the conventional melt molding method has a film thickness of 0.36 or more, which is different in both points.

The PCTFE according to the present invention
When the film is used for coating an EL element or the like, an adhesive layer can be provided on one or both sides of the film with a hot melt adhesive or the like. The hot melt adhesive layer may be formed on the surface of the PCTFE film by superposing the hot melt adhesive layer-forming component on the surface of the film and heating and pressing the same as in the conventional case. Even if the temperature at this time is set to a high temperature of 190 ° C. or higher, the crystallinity of the film does not become so large, and therefore the film does not become brittle.

Various components are known as hot melt adhesives, and they can be used in the present invention without any limitation, but preferably they are ethylene-glycidyl methacrylate copolymer or ethylene-glycidyl methacrylate. A vinyl acetate random terpolymer is used. Of course, it is also possible to add an appropriate amount of additives such as an antioxidant and a filler to these copolymers. Hot melt adhesives containing ethylene-glycidyl methacrylate copolymer as a component are "Bond First 2C" and "Bond First E" from Sumitomo Chemical Co., Ltd., and ethylene-glycidyl methacrylate-vinyl acetate random terpolymer is used as a component. Hot-melt adhesives are available from the same company as "Bond First 2B" and "Bond First 7B", so they can be obtained and used. In order to provide these hot melt adhesives on the surface of the PCTFE film, it is preferable to work at a temperature of 260 ° C. or lower in order to prevent deterioration of the adhesives.

This PCTFE film or a laminate having a hot melt adhesive layer provided on the surface of the film can be used for coating an EL device. The EL element has two electrodes, at least one of which is transparent and faces each other, and a light emitting layer sandwiched between the two electrodes.
It has a structure covered with a laminated film in which an adhesive layer is provided on a CTFE film or a PCTFE film.

The feature of this EL device is that it uses a PCTFE film having the above-mentioned specific physical property values as a coating film or a laminate having an adhesive layer on this film, and the device structure itself is the same as the conventional product. You may

FIG. 1 shows an example of an EL device according to the present invention, which has a transparent electrode 1 and a back electrode 2 facing it, and a light emitting layer 3 and an insulating layer 4 between these two electrodes 1, 2. PC with a thickness of 50-300 μm
The thickness of each side of the TFE film is about 10 to 150 μm
Is covered and sealed by the laminated bodies 5 and 6 provided with the hot melt adhesive layer. The back electrode is usually opaque because it is made of aluminum foil, copper foil, or the like, but it can be made transparent like the transparent electrode if desired.

As the transparent electrode 1, there is used a transparent substrate 7 on one side of which a transparent conductive layer 8 which is transparent in the visible light region and has conductivity is formed. As the transparent substrate, a glass plate or a film or plate made of synthetic resin can be used. The transparent conductive layer can be formed from a metal such as gold, silver, copper, indium and tin, a metal oxide such as indium oxide and tin oxide, or a mixture thereof, and the thickness thereof is usually about 50 to 1000 angstrom. The transparent conductive layer can be formed on the surface of the transparent substrate by a conventionally known method such as vacuum deposition method, sputtering method and ion plating method.

The light-emitting layer emits light when a voltage is applied, and can be formed of, for example, a mixture of a phosphor and a polymer dielectric as a binder, and the thickness thereof is usually about 20 to 10.
0 μm.

As the phosphor, zinc sulfide, zinc selenide,
As a main agent such as a mixed crystal of zinc sulfide and cadmium sulfide, a metal powder such as copper, gold, silver and manganese as an activator and a halogen such as chlorine, bromine and iodine as an activator or a metal powder such as aluminum and gallium. The added mixture can be used. In this case, the mixing ratio of the main agent, the activator and the activator is usually 0.01 to 0.1 part by weight of the activator and 1 to 3 parts by weight of the activator with respect to 100 parts by weight of the main agent.

Specific examples of the polymer dielectric as the binder include cellulosic resins such as cyanoethyl cellulose, fluororesins such as polyvinylidene fluoride and copolymers containing vinylidene fluoride, epoxy resins, unsaturated polyester resins, Organosilicon resin, melamine resin, urea resin, polyurethane resin and the like can be used.

The mixing ratio of the phosphor as the component for forming the luminous body layer and the binder may vary depending on various conditions, but usually 50 to 6 of the phosphors are added to 100 parts by weight of the binder.
It is 00 parts by weight.

For the light emitting layer, for example, a binder powder is dissolved in an organic solvent such as acetone, methyl ethyl ketone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, and the phosphor powder is dispersed in this solution. It can be formed by a method of coating and drying on top. In addition, the insulating layer can be formed of the same polymer dielectric as that used for forming the light emitting layer (if desired, a high dielectric constant powder such as barium titanate or titanium oxide is mixed).
This insulating layer can be omitted.

[0024]

The present invention will be described in more detail with reference to the following examples.

Example 1 An aqueous dispersion having a PCTFE concentration of 50% by weight was coated on a stainless steel plate and then heated at a temperature of 250 ° C. for 5 minutes to form a film. Then, after repeating this application and heating eight times each, the film is peeled from the stainless plate.

This PCTFE film has a thickness of 100 μm.
, And the its 1783cm infrared absorbance at ^-1 (A) an infrared absorbance at 0.040,2276cm ^-1 (B) is 0.184, absorbance ratio (A) / (B) was 0.22. An infrared spectrophotometer 5DXC manufactured by Nikole Co., Ltd. was used to measure the infrared absorbance, and the graphs recorded on the chart paper were used at 1783 cm ⁻¹ and 2276 c.
The peak height at m ⁻¹ was read and used as the absorbance.

This PCTFE film has a thickness of 50 on one side.
μm ethylene-glycidyl methacrylate copolymer film (Sumitomo Chemical Co., Ltd., trade name Bond First 2
B) are overlaid and the temperature is 200 ° C and the pressure is 1 kg / cm ^2.
By heating and pressurizing for 3 minutes under the conditions described above, a laminate was obtained.

Example 2 A PC having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the temperature after the dispersion was applied was 275 ° C.
A TFE film and a laminate having a hot melt adhesive layer formed on one surface of the TFE film were obtained. The infrared absorbance (A) at 1783 cm ⁻¹ of this PCTFE film was 0.059, the absorbance (B) at 2276 cm ⁻¹ was 0.185, and the absorbance ratio (A) / (B) was 0.32.

Comparative Example 1 PCTFE powder was extruded by a T-die extruder at a temperature of 310 ° C. and rapidly cooled to obtain a film having a thickness of 100 μm. The infrared absorbance (A) at 1783 cm ⁻¹ of this film was 0.071, the absorbance (B) at 2276 cm ⁻¹ was 0.187, and the absorbance ratio (A) / (B) was 0.3.
It was 8.

Next, a hot melt adhesive layer was formed on one surface of this PCTFE film in the same manner as in Example 1 to obtain a laminate.

Comparative Example 2 A laminate was obtained in the same manner as in Comparative Example 1 except that one side of the PCTFE film was subjected to sputter etching and a hot melt adhesive layer was provided on this treated surface.

For the sputter etching treatment, the apparatus described in Japanese Patent Publication No. 53-22108 was used. Atmospheric pressure 0.07 Torr, atmospheric gas Ar, discharge power 9 W
It was performed under the conditions of att / cm ² and processing time of 1 min.

Performance tests were conducted on the laminates obtained in these Examples and Comparative Examples according to the following procedure. The results obtained are shown in Table 1.

[Adhesive strength test] Two laminated bodies were prepared,
The hot-melt adhesive layers are superposed so that they face each other, heated and pressed under the conditions of a temperature of 150 ° C. and a pressure of 1 kg / cm ² for 1 minute to bond, and then an Instron type tensile tester (Tensilon manufactured by Orientec Co., Ltd.). ) With a temperature of 25
The adhesive strength was measured by the 90 ° peeling method under conditions of ° C and a pulling speed of 300 mm / min. The unit of the adhesive force is "kg / cm".

[Crack Test] Two laminates were joined in the same manner as in the adhesive strength test, and bent so as to have a radius of curvature of 5 mm to obtain a test piece. Leave it in an atmosphere of 95% relative humidity for 1 week,
The presence or absence of cracks was visually observed. 5 in Table 1
The number of test pieces in which cracks occurred among the test pieces was shown.

[Foaming Test] In the adhesive strength test, the presence or absence of foaming on the hot melt adhesive layer and the PCTFE film due to decomposition gas was visually observed.

[0037]

[0038]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, even if an adhesive layer is provided on the surface thereof, the degree of crystallinity does not increase, cracking does not easily occur due to stress stress, and foaming by decomposition gas occurs. In addition, the adhesive layer can be firmly adhered.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an actual example of an EL element according to the present invention.

[Explanation of symbols]

 1 Transparent Electrode 2 Back Electrode 3 Light-Emitting Layer 4 Insulating Layer 5 Laminated Body 6 Laminated Body

Claims (4)

(57) [Claims] ^1. An infrared absorbance (A) at 1783 cm ^{-1 and} an infrared absorbance (B) at 2276 cm ^-1 .
The ratio (A) / (B) is 0.35 or less, a polychlorotrifluoroethylene film. Wherein the infrared absorbance at 1783 cm ^-1 and (A), an infrared absorbance at 2276cm ^-1 (B)
And a ratio of (A) / (B) is 0.35 or less, a laminate comprising an adhesive layer provided on the surface of a polychlorotrifluoroethylene film. 3. The adhesive layer is formed by a hot-melt adhesive containing at least one of an ethylene-glycidyl methacrylate copolymer and an ethylene-glycidyl methacrylate-vinyl acetate ternary random copolymer as an essential component. 2. The laminate according to 2. 4. An electrode comprising two electrodes, at least one of which is transparent and facing each other, a light emitting layer sandwiched between the two electrodes, and a polychlorotrifluoroethylene layer which covers the two layers, the coating layer comprising: A film according to claim 2,
An electroluminescent device which is either the laminate according to claim 3 or the laminate according to claim 3.