JP2004319448A - Vacuum envelope for image display device, sealant for image display device, image display device, and sealing method of vacuum envelope for image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead-free organic sealant capable of sealing at a temperature of lower than 400°C while having excellent strength at high temperatures. <P>SOLUTION: This organic sealant for sealing an envelope component for constituting a vacuum envelope for an image display device, is characterised in that the baked body of the organic sealant has a lowest viscosity of 10<SP>3</SP>Pas or less within the temperature range of 300°C to <400°C, and the baked body of the organic sealant satisfies, when the mass at 20°C is m<SB>20</SB>, and the mass at 400°C is m<SB>400</SB>, 0.99<m<SB>400</SB>/m<SB>20</SB>≤1.00. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image display device used for a television broadcast receiver or a monitor device in a video device, specifically an image display device having a cathode ray tube and a field emission cold cathode, and an image display used for manufacturing the same. The present invention relates to a vacuum envelope for an apparatus, an organic sealing material, and a sealing method for a vacuum envelope for an image display apparatus using the organic sealing material.

  Generally, an image display device (FED) having a cathode ray tube (CRT) or a field emission type cold cathode (hereinafter referred to collectively as an image display device) has two or more members, specifically, a CRT. In the case of an image display panel section (glass panel section) on which an image is projected, a glass funnel section having an electron gun, and in the case of FED, typically a front panel section (image display panel section), the front panel section A rear panel portion having a cold cathode disposed opposite to the outer panel, and an outer frame that surrounds and surrounds the front panel portion and the rear panel portion. A vessel is formed.

Conventionally, these seals are made by mixing frit glass with a vehicle, making it into a slurry, applying it to the end face, drying it at a relatively low temperature and then firing it at a higher temperature, or attaching a sheet to the end face. It is carried out by firing. As the frit glass, a PbO—B ₂ O ₃ —ZnO—SiO ₂ based crystalline low melting point solder glass having a high lead content is used. An example using such a frit glass is described in Patent Document 1.
The envelope after sealing is evacuated at a high temperature of about 250 to 380 ° C. in order to make the inside high vacuum. At this time, the sealing portion has tensile stress (hereinafter referred to as vacuum stress) caused by the vacuum inside the envelope and tensile stress (hereinafter referred to as “vacuum stress”). Is called a thermal stress), and the strength to withstand these stresses is required.
Further, in order to ensure long-term reliability of the image display device, the sealing portion is required to have a pressure strength of 0.3 MPa or more, high airtightness, and insulation.

In recent years, the CRT has been increased in size and flattened, and slight deformation of a metal member such as a built-in shadow mask causes an electron beam misalignment, which adversely affects an image. Thus, the thermal deformation of the metal in the sealing process, which has not been a problem before, has been brought up, and a reduction in the sealing temperature is desired. It has been found that such thermal deformation is almost suppressed by setting the sealing temperature to less than 400 ° C.
In addition, in the case of FED, the back substrate disposed in the vacuum envelope has a multilayer structure such as a cathode electrode, a resistance layer, an emitter, and an insulating layer. It is desired to be done at low temperatures. Further, although depending on the type of emitter, there is a concern that at a sealing temperature of 400 ° C. or higher, the emitter is oxidized and the electron emission characteristics deteriorate.
Therefore, a sealing material that can be sealed at less than 400 ° C. is desired.

  However, in the sealing using the conventional frit glass, the firing temperature is required to be 400 ° C. or higher, and when the sealing is performed at the firing temperature of less than 400 ° C., the strength of the sealed portion is not sufficient. There is a problem that the sealing part may be broken in the high-temperature evacuation process, and that the long-term reliability of the vacuum envelope cannot be ensured. Moreover, although the conventional frit glass contains 60 mass% or more of lead as PbO, in view of the influence on the environment, it is desired to make it lead-free.

As the sealing material that can be sealed at less than 400 ° C. and does not contain lead, organic sealing materials such as epoxy resins and silicone resins can be considered. Examples using such an epoxy resin are described in Patent Document 1 and Patent Document 2. However, these conventional organic sealing materials have (1) insufficient adhesive strength with glass, (2) insufficient strength at high temperature, (3) the sealing material itself decomposes during high-temperature evacuation, There are problems such as generating gas and adversely affecting the electron gun or the cold cathode, and (4) high gas permeability and inability to maintain a high vacuum. Examples of other organic sealing materials include polybenzimidazole resin, polyimide resin, and an example of using an adhesive containing a polyphenyl compound in Patent Documents 3 to 5, and polyimide resin and parahydroxybenzoic acid. Examples of using a molten liquid crystal polymer resin obtained by copolymerizing terephthalic acid, biphenols, 2,6-naphthalenedicarboxylic acid, hydroxynaphthoic acid, isophthalic acid, etc., or using the molten liquid crystal polymer resin alone. It is described in Patent Document 6. However, these organic sealing materials do not solve the problems (1) to (4) described above.
Lead-free inorganic sealing materials such as bismuth-based materials using bismuth compounds instead of lead and phosphate-based materials using phosphates have also been proposed, but (5) sufficient strength Cannot be secured, and (6) it is difficult to seal at less than 400 ° C.

JP 52-124854 A JP-A-4-245153 JP 2000-21298 A JP 2000-251768 A JP 2000-251769 A JP-A-10-275573

As mentioned above, in view of the problems in the prior art, the present invention has a sufficient strength against the vacuum stress and thermal stress generated in the manufacturing process of the image display device. It is a first object of the present invention to provide a vacuum envelope for an image display device in which the problem of cracking of the sealing portion does not occur.
The vacuum envelope for the image display device preferably has a sufficient electrical breakdown strength at the sealing portion, and the sealing portion is preferably lead-free.

The present invention also provides an organic sealant for an image display device that can be sealed at a temperature of less than 400 ° C. and has a sufficient strength in a high-temperature environment that the fired body experiences in the manufacturing process of the image display device. The second object is to provide the above.
It is preferable that the organic sealing material does not substantially decompose under the high temperature environment that the fired body experiences in the manufacturing process of the image display device, and therefore does not generate decomposition gas.
Furthermore, it is preferable that the organic sealing material is excellent in handleability in a high temperature environment experienced in the manufacturing process of the image display device.

  It is a third object of the present invention to provide an image display device that does not cause a problem of cracking of the sealing part in the manufacturing process and has excellent display characteristics.

  It is a fourth object of the present invention to provide a sealing method for a vacuum envelope for an image display device that is easy to operate and does not cause a problem of cracks in the sealing portion during the process. .

The present invention has been made to achieve the above-described object, and is a vacuum envelope obtained by sealing an envelope constituent member including at least an image display portion made of glass via a sealing material layer. The sealing material layer includes an organic sealing material layer obtained by firing an organic sealing material, and the organic sealing material layer is interposed between the organic sealing material layer and the organic sealing material layer. A vacuum envelope for an image display device is provided, wherein a bending strength of a sealing portion composed of an envelope constituent member to be sealed is 30 MPa or more at 220 ° C.
In the envelope for an image display device, it is preferable that the sealing portion has an electrical breakdown strength of 3 kV / mm or more.
When the image display device is a cathode ray tube, it is preferable that the sealing portion of the envelope for the image display device has an electrical breakdown strength of 15 kV / mm or more.
In the vacuum envelope for an image display device, it is preferable that the organic sealing material layer does not substantially contain lead.

Further, the present invention is an organic sealing material for sealing an envelope constituent member constituting a vacuum envelope of an image display device,
The organic sealing material has a minimum viscosity of 10 ³ Pa · s or less in a temperature range of 300 ° C. or more and less than 400 ° C.,
The fired body of the organic sealing material is characterized in that when the mass at 20 ° C. is m ₂₀ and the mass at 400 ° C. is m ₄₀₀ , 0.99 <m ₄₀₀ / m ₂₀ ≦ 1.00. An image display device sealing material is provided.

The sealing material for an image display device preferably has a glass transition temperature of 175 ° C. or higher by a differential scanning calorimeter (DSC) of the fired body of the organic sealing material.
The sealing material for an image display device preferably has a bending elastic modulus at 220 ° C. of the fired body of the organic sealing material of 100 MPa or more.

Further, the sealing material for an image display device preferably contains a polyimide compound or a polyamic acid compound as a main component.
The sealing material for an image display device has an imide group content ratio (imide group molecular weight / polyimide molecular weight) in the polyimide compound or an amide group content ratio (amide group molecular weight / polyamic acid molecular weight) in the polyamic acid compound of 10 to 31%. It is preferable that it is the range of these.

式１ないし式３中、Ｘはジアミン化合物の主骨格であり、Ｘ’はモノアミン化合物の主骨格であり、Ｙはテトラカルボン酸二無水物の主骨格であり、Ｙ’はジカルボン酸無水物の主骨格である。なお、ＸおよびＹは、より具体的には以下の意味を示す。
（Ａ）Ｘが下記式４〜式８のうちのいずれか一つのとき、Ｙは下記式９〜式１４のうちのいずれか一つである。下記式４〜式８において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。
（Ｂ）Ｘが下記式１５のとき、は下記式１６または式１７である。下記式１５において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。 More preferably, the sealing material for an image display device contains at least one of the polyimide compounds having a structure represented by the following formulas 1 to 3 as a main component.

In Formulas 1 to 3, X is the main skeleton of the diamine compound, X ′ is the main skeleton of the monoamine compound, Y is the main skeleton of tetracarboxylic dianhydride, and Y ′ is the dicarboxylic acid anhydride. The main skeleton. X and Y have the following meanings more specifically.
(A) When X is any one of the following formulas 4 to 8, Y is any one of the following formulas 9 to 14. In the following formulas 4 to 8, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ —, and —C (CH ₃ ) _2. Each of n is independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.
(B) When X is the following formula 15, is the following formula 16 or formula 17. In the following formula 15, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) _2. N is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.

式２０において、Ｘが下記式４〜式８からなる群から選択されるいずれか一つのとき、Ｙは下記式９〜式１４からなる群から選択されるいずれか一つであり、
Ｘが下記式１５のとき、Ｙは下記式１６または式１７であり、
Ｘが下記式１８のとき、Ｙは下記式１９である。 More preferably, the sealing material for an image display device contains a polyamic acid compound having a structure represented by the following formula 20 as a main component.

In Formula 20, when X is any one selected from the group consisting of the following Formula 4 to Formula 8, Y is any one selected from the group consisting of the following Formula 9 to Formula 14,
When X is the following formula 15, Y is the following formula 16 or formula 17,
When X is the following formula 18, Y is the following formula 19.

上記式中、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは各々独立にＣＨ₃またはフェニル基である。

In the above formula, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) ₂ . One, n is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.

In addition, the present invention provides a vacuum envelope for an image display device, wherein the envelope constituent member is sealed with the above-described sealing material for an image display device.
Moreover, this invention provides the image display apparatus provided with said vacuum envelope for image display apparatuses.

Further, an organic sealing agent mainly composed of a polyimide compound or a polyamic acid compound or a solution thereof is applied to the sealing surface of the envelope constituent member constituting the vacuum envelope, and then 300 ° C. or higher and lower than 400 ° C. A method for sealing a vacuum envelope for an image display device, wherein the organic sealant is baked and solidified by heating to a temperature in the range of I will provide a.
Furthermore, it is preferable that the organic sealing material contains at least one of the polyimide compounds having the structures represented by the above formulas 1 to 3 as a main component.
Furthermore, the organic sealing material preferably contains a polyamic acid compound having a structure represented by the above formula 20 as a main component.

The vacuum envelope for an image display device according to the present invention has a sufficient bending strength at the sealing portion against the vacuum stress and the thermal stress generated in the manufacturing process of the image display device, particularly in the high-temperature evacuation process of the vacuum envelope. Therefore, the cracking problem of the sealing portion of the vacuum envelope in the manufacturing process of the image display device is solved.
The vacuum envelope for an image display device of the present invention has excellent electrical insulation strength at the sealing portion, and has preferable characteristics as a vacuum envelope for an image display device.
The vacuum envelope for an image display device of the present invention is lead-free because it is sealed with an organic sealing material, and the influence on the environment is considered.

Since the sealing material for an image display device of the present invention is an organic sealing material not containing lead, the influence on the environment is taken into consideration and the sealing is possible at a temperature of less than 400 ° C. The body has sufficient strength under the high temperature environment experienced in the manufacturing process of the image display device.
Further, the sealing material for an image display device of the present invention does not substantially generate decomposition gas in a high temperature environment that the fired body experiences in the manufacturing process of the image display device, and has an adverse effect on the manufactured image display device. There is no effect.
Furthermore, the sealing material for an image display device of the present invention is excellent in handleability in a high temperature environment experienced in the manufacturing process of the image display device.

  The image display device of the present invention is excellent in display characteristics because the sealing part is not cracked in the manufacturing process and the sealing material is baked at less than 400 ° C. in the manufacturing process.

  The method for sealing a vacuum envelope for an image display device according to the present invention is easy to operate and does not cause a problem of cracking of the sealing portion during the process.

Hereinafter, the present invention will be described in detail with reference to the drawings.
In the present invention, the image display device is of a so-called cathodoluminescence type in which electrons emitted from a cathode (cathode) and moving at a high speed collide with a phosphor to excite and emit light under high vacuum. Such a cathode luminescence type image display device is represented by a cathode ray tube (CRT) and an image display device (FED) having a field emission cold cathode.
Such an image display device includes a vacuum envelope having a high vacuum inside in order to realize cathodoluminescence. In the vacuum envelope, there are installed a drive circuit for emitting a high-speed electron beam, and an image display panel unit coated with a phosphor that is excited when the electron beam collides to generate fluorescence. Has been.
The image display apparatus of the present invention will be described in detail below by taking the configuration of a conventional CRT and FED as an example. However, the image display device of the present invention is not limited to CRT and FED, but widely includes image display devices including a vacuum envelope. As another example of an image display device provided with a vacuum envelope, there is a fluorescent display tube (VFD), for example.

FIG. 1 is a partially cutaway side view of an embodiment of an image display apparatus of the present invention, and the image display apparatus 1 is configured as a CRT. In FIG. 1, the right side of the drawing is the front side and the left side is the rear side.
In FIG. 1, the image display device 1 includes a vacuum envelope (glass bulb) 11 including an image display panel unit 2 and a glass funnel unit 3. The image display panel unit 2 constituting the front side of the vacuum envelope 11 is located in front of the vacuum envelope 11 and has a substantially planar image display region 21 for displaying an image, and the side of the face unit including the image display region 21. The skirt portion 22 extends rearward from the portion. A neck 31 for storing the electron gun 4 is provided at the rear end of the glass funnel portion 3 constituting the rear side of the vacuum envelope 11. The image display panel unit 2 and the glass funnel unit 3 constituting the vacuum envelope 11 are usually made of glass. However, the image display region 21 of the image display panel unit 2 may not be entirely made of glass, but may be a multilayer material made of a light-transmitting resin on the front side. Further, the constituent member of the vacuum envelope 11 may be made of an inorganic material other than glass, specifically, ceramic or metal.
In addition to the above, in the image display device 1 of FIG. 1, an explosion-proof reinforcement band 17 for maintaining strength, a phosphor 13 that emits fluorescence by interaction with an electron beam emitted from the electron gun 16, and the fluorescence on the image display surface An aluminum film 14 that reflects toward the side 21; a shadow mask 15 for landing the electron beam at a predetermined position of the phosphor 13; a stud pin 18 for fixing the shadow mask 15 to the inner wall of the skirt 22; Including.

  In the image display device 1 of the present invention, the image display panel unit 2 that is a constituent member of the vacuum envelope 11 and the glass funnel unit 3 are sealed through an organic sealing material layer 5. The organic sealing material layer 5 is obtained by applying an organic sealing material on the sealing surface of the vacuum envelope constituting member or attaching it as a film, followed by firing under desired conditions by a method described later. It is a layer of a fired body of a sealing material. In the image display device 1 of FIG. 1, the rear end face of the skirt portion 22 of the image display panel section 2 and the front end face of the glass funnel section 3 are sealed via the organic sealing material layer 5. Yes. In the image display device 1 of the present invention, the sealing portion of the vacuum envelope 11, specifically, the organic sealing material layer 5, and the vacuum envelope configuration sealed by the organic sealing material layer 5 The bending strength of the member portion, that is, the sealing portion composed of the rear end portion of the skirt portion 22 and the front end portion of the funnel portion 3 in FIG. 1, is 30 MPa or more at 220 ° C.

  In the present invention, the bending strength of the sealing portion of the vacuum envelope of the image display device is the bending strength of the organic sealing material layer 5 itself made of a fired body of the organic sealing material, and the organic sealing. It means both the bending strength of the sealing portion including the material layer 5 and the portion of the envelope constituent member adjacent thereto. The image display device of the present invention is characterized in that the bending strength of the sealing portion of the vacuum envelope is 30 MPa or more at 220 ° C. Here, the bending strength can be determined, for example, as a measurement value of a four-point bending test performed by a method according to JIS R1601, as described in the examples described later.

  The vacuum envelope 11 after sealing is evacuated at a high temperature in order to make the inside high vacuum. This high-temperature evacuation has been conventionally performed at 250 to 380 ° C. However, as described in the prior art, it is preferable that the heat treatment at the time of manufacturing the image display device is performed at the lowest possible temperature. Therefore, it is considered that the high-temperature evacuation will be performed at a temperature of 200 to 330 ° C. in the future. At this time, vacuum stress and thermal stress are applied to the sealing portion of the vacuum envelope. In the image display device of the present invention, since the bending strength of the sealing portion of the vacuum envelope is 30 MPa or more at 220 ° C., the manufacturing process of the image display device, particularly during the high-temperature evacuation process of the vacuum envelope. The sealing part has sufficient strength against the applied vacuum stress and thermal stress, and the cracking problem of the sealing part during the high temperature evacuation process of the vacuum envelope has been solved. Yes.

In the image display device of the present invention, the bending strength at 220 ° C. of the sealing portion of the vacuum envelope is more preferably 40 MPa or more. If the bending strength of the sealed portion of the vacuum envelope at 220 ° C. is 40 MPa or more, the strength against vacuum stress and thermal stress applied during the high-temperature vacuum exhaust process is particularly excellent.
In the image display device of the present invention, it is preferable that the bending strength of the sealed portion of the vacuum envelope in a temperature range of 200 to 330 ° C. is always 30 MPa or more. If the bending strength of the sealed part of the vacuum envelope is always 30 MPa or more in the above temperature range, the sealed part always has sufficient strength in the temperature range expected in the high-temperature evacuation process to be performed in the future. Have. More preferably, the bending strength of the sealing part of the vacuum envelope in the temperature range of 200 to 330 ° C. is always 40 MPa or more.

FIG. 2 is a partially cutaway side view of another embodiment of the image display device of the present invention, the image display device being configured as a typical FED. In FIG. 2, the upper side of the drawing is the front side and the lower side is the rear side. In the image display device 1 ′ of FIG. 2, a front panel portion (image display panel portion) 2 ′ positioned on the front side thereof, and a rear panel portion 3 ′ disposed opposite to the front panel portion 2 ′ on the rear side thereof, A vacuum envelope 11 ′ is constituted by the front frame 2 ′ and the outer frame 4 disposed between the rear panel 3 ′. The front panel part 2 ′, the rear panel part 3 ′ and the outer frame 4 which are constituent members of the vacuum envelope 11 ′ are usually made of glass. However, it may be made of an inorganic material other than glass, for example, ceramic or metal. Here, the joint surfaces of the constituent members of the vacuum envelope 11 ′ are sealed through the organic sealing material layer 5. Therefore, the joint surface between the front panel portion 2 ′ and the outer frame 4 and the joint surface between the rear panel portion 3 ′ and the outer frame 4 are sealed through the organic sealing material layer 5. In the image display device 1 ′, the rear panel unit 3 ′ is a field emission type electron source substrate. On the inner side surface thereof, that is, on the surface facing the front panel unit 2 ′, the cathode 61 and the cathode 61 are provided. A field emission cold cathode 62 is formed. A gate electrode 63 for controlling the electron flow is formed across the insulating layer 64 on the surface of the rear panel portion 3 ′ facing the front panel portion 2 ′. On the other hand, a phosphor pixel 66 that is paired with the anode 65 and the field emission type cold cathode 62 is provided on the surface of the front panel portion 2 ′ that faces the rear panel portion 3 ′.
Then, similarly to the image display device 1 of the first embodiment of the present invention, a vacuum envelope comprising an organic sealing material layer and an envelope constituent member adjacent to the organic sealing material layer. The bending strength of the sealing part is 30 MPa or more at 220 ° C.

  In the image display device of the present invention, the organic sealing material which is fired to form the organic sealing material layer is usually used as a heat-resistant adhesive, and the fired body has the above-mentioned characteristics. Including widely. The organic sealing material that can be used in the image display device of the present invention will be described in detail later.

In the image display device of the present invention, the sealing portion of the vacuum envelope needs to have electrical insulation. Therefore, the sealing portion of the vacuum envelope preferably has an electrical breakdown strength of 3 kV / mm or more. The electrical breakdown strength required for the sealing portion of the vacuum envelope varies depending on the configuration of the image display device. Specifically, when the image display device is configured as a CRT as in the first embodiment of the present invention, the electrical breakdown strength of the sealing portion is preferably 15 kV / mm or more, and is 20 kV / mm or more. More preferably, it is more preferably 25 kV / mm or more. On the other hand, when the image display device is configured as an FED as in the second embodiment of the present invention, the electrical breakdown strength of the sealing portion is preferably 3 kV / mm or more, and 8 kV / mm or more. Is more preferable.
If the electrical breakdown strength of the sealing portion of the vacuum envelope is as described above, there is no possibility of causing an insulation failure during operation of the image display device.

The image display device of the present invention is characterized in that an organic sealing material containing no lead is used as a sealing material for the envelope constituent member. Therefore, in the image display device of the present invention, it is preferable that the sealing portion of the vacuum envelope does not substantially contain lead. Here, “the sealing part is substantially free of lead” means that the lead content in the organic sealing material layer constituting the sealing part is usually adhered as an impurity to the glass constituting the envelope component. The amount of lead that is diffused is specifically 0.1 mass% or less with respect to the mass of the organic sealing material constituting the organic sealing material layer. Preferably it is 0.01 mass% or less, and it is further more preferable that it is 0.001 mass% or less.
In the image display device of the present invention, a lead-free inorganic sealing material such as phosphoric acid or bismuth may be used in combination, provided that the above conditions are satisfied. Such an inorganic sealing material requires that the image display device includes a component that needs to be sealed at a higher temperature, specifically, 400 ° C. or more, or to match characteristics. It is preferably used in such cases.

  As described above, in the present invention, the organic sealing material for the vacuum envelope is an organic compound usually used as a heat-resistant adhesive, and 220 of the sealing portion of the vacuum envelope defined above. Widely includes those having a bending strength at 30 ° C. of 30 MPa or more. Specific examples of such organic compounds include polyimide and its precursor polyamic acid, polybenzimidazole, polyquinoxaline, polyphenylquinoxaline, acetylene-terminated polyimide, polyphenylquinoxaline and the like.

The organic sealing material of the present invention requires that the fired body has excellent heat resistance. In the present invention, regarding the heat resistance of the fired body of the organic sealing material, the ratio of the mass at 20 ° C. (normal temperature) to the mass at 400 ° C. (hereinafter referred to as “mass ratio at 400 ° C. heating”). .). Specifically, when the mass of the fired body at 20 ° C. is m ₂₀ and the mass of the fired body at 400 ° C. is m ₄₀₀ , the value of m ₄₀₀ / m ₂₀ indicates the mass ratio when heated at 400 ° C. .
The organic sealing material of the present invention has a mass ratio (value of m ₄₀₀ / m ₂₀ ) of the fired body when heated at 400 ° C. of 0.99 <m ₄₀₀ / m ₂₀ ≦ 1.00. More preferably, 0.993 <m ₄₀₀ / m ₂₀ ≦ 1.00. When the mass ratio of the fired body when heated at 400 ° C. is in the above range, the organic sealing material is decomposed at the sealing portion during the high-temperature evacuation process of the vacuum envelope, and a large amount of decomposition gas is generated. There is no risk of generation, the characteristics of the obtained image display device are good, and there is no risk of vacuum failure.
The organic sealing material is fired under normal conditions in the manufacturing process of the image display device. Specifically, for example, it may be performed in an inert gas atmosphere such as a nitrogen atmosphere or an argon gas atmosphere, or may be performed in the air. The firing temperature is usually in the range of 300 ° C. or more and less than 400 ° C., and is higher than the temperature in the subsequent high-temperature evacuation process.

Further, the organic sealing material in the present invention needs to have a moderately low viscosity when sealing the envelope constituent member. That is, the sealing of the envelope constituent member is performed by firing the organic sealing material, and the temperature range of 300 ° C. or more and less than 400 ° C. that the organic sealing material may experience during the firing. The minimum viscosity of the fired body of the organic sealing material is required to be 10 ³ Pa · s or less. The minimum viscosity of the fired body of the organic sealing material in the temperature range is more preferably 5 × 10 ² Pa · s or less. When the minimum viscosity of the organic sealing material in the temperature range is within the above range, the fluidity of the organic sealing material at the time of sealing is sufficient, the sealing part has excellent strength, and the image display device There is no risk of the problem of cracking of the sealing part during the manufacturing process, particularly during the high-temperature evacuation process of the vacuum envelope.

  Since the organic sealing material of the present invention is used as a sealing material for the surrounding structural member, it is preferable that the thermal expansion characteristics of the fired body do not change significantly in the high temperature region as the characteristics of the sealing material itself. That is, the organic sealing material of the present invention preferably has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of the fired body of 175 ° C. or higher, more preferably 220 ° C. or higher. Yes, more preferably 250 ° C or higher.

Moreover, it is preferable that the organic sealing material of this invention is excellent in the mechanical strength in the high temperature environment of the sintered body. That is, the organic sealing material of the present invention preferably has a flexural modulus at 220 ° C. of the fired body of 100 MPa or more, more preferably 300 MPa or more, and further preferably 500 MPa or more.
Specifically, the bending elastic modulus of the fired body of the organic sealing material can be obtained by a dynamic viscoelasticity measuring device (DMS: dynamic mechanical spectrometer) as described in the examples described later, for example. it can.
When the bending elastic modulus at 220 ° C. of the fired body of the organic sealing material is 100 MPa or more, the sealing portion of the vacuum envelope of the obtained image display device is loaded with strength, particularly during the high-temperature vacuum exhaust process. It has sufficient strength against vacuum stress and thermal stress, and there is no possibility of causing a problem of cracking of the sealing part during the manufacturing process, particularly during the high-temperature evacuation process of the vacuum envelope.

The organic sealing material of the present invention having the above properties preferably contains a polyimide compound or a polyamic acid compound as a precursor thereof as a main component.
When the organic sealing material of the present invention contains a polyimide compound or a polyamic acid compound which is a precursor thereof as a main component, the imide group content ratio (imide group molecular weight / polyimide molecular weight) in the polyimide compound or the amide in the polyamic acid compound The group content (amide group molecular weight / polyamic acid molecular weight) is preferably in the range of 10 to 31%, more preferably 14 to 26%. When the imide group content ratio in the polyimide compound or the amide group content ratio in the polyamic acid compound is within the above range, high adhesive strength can be exhibited.

上記式１中、Ｘはジアミン化合物の主骨格を示し、Ｙはテトラカルボン酸二無水物の主骨格を示す。ここでジアミン化合物の主骨格とは、ジアミン化合物のアミノ基を除いた主鎖を意味し、テトラカルボン酸二無水物の主骨格とは、カルボン酸二無水物を除いた主鎖を意味する。
Ｘ、Ｙは、より具体的には、以下を意味する。
（Ａ）Ｘが下記式４〜式８のうちのいずれか一つのとき、Ｙは、下記式９〜式１４のうちのいずれか一つである。下記式４〜式８において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。
（Ｂ）Ｘが下記式１５のとき、は下記式１６または式１７である。下記式１５において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。 As a polyimide compound, the polyimide compound which has a structure shown in following formula 1 is preferable.

In the above formula 1, X represents the main skeleton of the diamine compound, and Y represents the main skeleton of the tetracarboxylic dianhydride. Here, the main skeleton of the diamine compound means the main chain excluding the amino group of the diamine compound, and the main skeleton of the tetracarboxylic dianhydride means the main chain excluding the carboxylic dianhydride.
More specifically, X and Y mean the following.
(A) When X is any one of the following formulas 4 to 8, Y is any one of the following formulas 9 to 14. In the following formulas 4 to 8, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ —, and —C (CH ₃ ) _2. Each of n is independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.
(B) When X is the following formula 15, is the following formula 16 or formula 17. In the following formula 15, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) _2. N is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.

The polyimide compound may be composed only of the structure represented by Formula 1, but the terminal portion may be sealed with a monoamine or dicarboxylic anhydride. The polyimide compound whose terminal is sealed with a monoamine or dicarboxylic anhydride preferably has a structure represented by the following formula 2 or formula 3. In the following formulas 2 and 3, X and Y are the same as defined in formula 1, X ′ represents the main skeleton of the monoamine compound, and Y ′ represents the main skeleton of the dicarboxylic acid anhydride. Here, the main skeleton of the monoamine compound means the main chain excluding the amino group of the monoamine compound, and the main skeleton of the dicarboxylic acid anhydride means the main chain excluding the carboxylic acid anhydride.

上記式２０中、Ｘはジアミン化合物の主骨格を示し、Ｙはテトラカルボン酸二無水物の主骨格を示す。
（Ａ）Ｘが上記式４〜式８のうちのいずれか一つのとき、Ｙは、上記式９〜式１４のうちのいずれか一つである。上記式４〜式８において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。
（Ｂ）Ｘが上記式１５のとき、は上記式１６または式１７である。上記式１５において、Ｒは、各々独立に−、−Ｏ−、−ＣＯ−、−ＳＯ₂−、−Ｓ−、−ＣＨ₂−および−Ｃ（ＣＨ₃）₂からなる群から選択されるいずれか一つであり、ｎは各々独立に０〜７であり、Ｚは、各々独立にＣＨ₃またはフェニル基である。
（Ｃ）Ｘが上記式１８のとき、Ｙは上記式１９である。 As the polyamic acid compound, specifically, a polyamic acid compound represented by the following formula 20 is preferable.

In the above formula 20, X represents the main skeleton of the diamine compound, and Y represents the main skeleton of the tetracarboxylic dianhydride.
(A) When X is any one of the above formulas 4 to 8, Y is any one of the above formulas 9 to 14. In the above formulas 4 to 8, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ —, and —C (CH ₃ ) _2. Each of n is independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.
(B) When X is the above formula 15, is the above formula 16 or 17. In the above formula 15, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) _2. N is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.
(C) When X is the above formula 18, Y is the above formula 19.

  The polyimide compound having the structure of Formula 1 and the polyamic acid compound of Formula 20 are synthesized by condensation of a diamine compound and tetracarboxylic dianhydride. In the same manner as in the case of ordinary polycondensation polymers, the molecular weight can be controlled by adjusting the molar ratio of the monomer components. That is, a high molecular weight body can be formed by using 0.8 to 1.2 mol of a diamine compound with respect to 1 mol of tetracarboxylic dianhydride. When the polyimide compound or the polyamic acid compound is a high molecular weight body, the fired body is excellent in mechanical strength, electrical insulation and the like, and is preferable as an organic sealing material because it does not generate outgas in a high temperature environment. . The above molar ratio is more preferably 0.9 to 1.1 mol of the diamine compound and further preferably 0.95 to 1.05 mol with respect to 1 mol of the acid dianhydride.

Specific examples of the diamine that can be used to synthesize the polyimide compound having the structure of Formula 1 or the polyamic acid compound of Formula 20 include the following diamine compounds.
a) p-phenylenediamine and m-phenylenediamine having one benzene ring.
b) 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,4′-diaminodiphenyl sulfide having two benzene rings 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 4,4′- Diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-di (3-aminophenyl) propane, 2, 2-di (4-aminophenyl) propane, 2- (3-amino Enyl) -2- (4-aminophenyl) propane, 2,2-di (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-di (4-amino) Phenyl) -1,1,1,3,3,3-hexafluoropropane, 2- (3-aminophenyl) -2- (4-aminophenyl) -1,1,1,3,3,3-hexa Fluoropropane, 1,1-di (3-aminophenyl) -1-phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4 -Aminophenyl) -1-phenylethane.

  c) 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene having three benzene rings, 1, 4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzoyl) benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene 1,4-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (3-amino-α) α-ditrifluoromethylbenzyl) benzene, 1,3-bis (4-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene 1,4-bis (4-amino-α, α-ditrifluoromethylbenzyl) benzene, 2,6-bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine.

  d) 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone having four benzene rings Bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3- Aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 2 , 2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl Nyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] -1,1,1,3,3,3-hexafluoropropane.

e) 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,4-bis having 5 benzene rings [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α- Dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl ] Benzene, 1,4-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene.
f) 4,4′-bis [4- (4-aminophenoxy) benzoyl] diphenyl ether having 6 benzene rings, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] Benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4′-bis [4- (4-aminophenoxy) phenoxy] diphenylsulfone.

g) 3,3′-diamino-4,4′-diphenoxybenzophenone, 3,3′-diamino-4,4′-dibiphenoxybenzophenone having an aromatic substituent, 3,3′-diamino-4- Phenoxybenzophenone, 3,3′-diamino-4-biphenoxybenzophenone.
h) 6,6′-bis (3-aminophenoxy) 3,3,3,3,3′-tetramethyl-1,1′-spirobiindane 6,6′-bis (4-aminophenoxy) having a spirobiindane ring ) 3,3,3, '3,'-tetramethyl-1,1'-spirobiindane.
i) 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) which are siloxane diamines ) Polydimethylsiloxane, α, ω-bis (3-aminobutyl) polydimethylsiloxane.

j) Ethylene glycol diamines, bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis (2-aminomethoxy) ethyl] ether, bis [2- ( 2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1, 2-bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether, diethylene glycol bis (3-aminopropyl) ) Ether, triethylene glycol bis (3-aminopropyl) ether. k) Methylenediamines, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diamino Octane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane.
l) Alicyclic diamines such as 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di ( 2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane is exemplified.

In addition, the diamine compounds exemplified above can be used alone or in combination as appropriate. In the diamine compound, part or all of the hydrogen atoms on the aromatic ring of the diamine compound are substituted with a substituent selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group. Diamine may be used.
Furthermore, an ethynyl group, a benzocyclobuten-4′-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrilo group, and an isopropenyl group, which serve as a crosslinking point, are bonded to the hydrogen atom on the aromatic ring of the diamine. Some or all of them may be introduced as substituents. Furthermore, a vinylene group, a vinylidene group, and an ethynylidene group serving as a crosslinking point may be incorporated in the main chain skeleton instead of a substituent.
For the purpose of introducing branching, a part of the diamine compound may be replaced with triamines or tetraamines.

Specific examples of the tetracarboxylic dianhydride that can be used to synthesize the polyimide compound having the structure of Formula 1 and the polyamic acid compound of Formula 20 include the following.
Pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2-bis (3,4-dicarboxy) Phenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4 -Dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2 , 2- [(3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, Ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 2,2', 3 3'-biphenyltetracarboxylic dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1 , 3,3,3-hexafluoropropane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) sulfide dianhydride, bis 2,3-dicarboxyphenyl) sulfone dianhydride, 1,3-bis (2,3-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (2,3-dicarboxyphenoxy) benzene dianhydride , And 1,2,5,6-naphthalenetetracarboxylic dianhydride.

The tetracarboxylic dianhydrides exemplified above can be used alone or in combination as appropriate.
In addition, any of the above tetracarboxylic dianhydrides was selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group for some or all of the hydrogen atoms on their aromatic rings. It can also be used after being substituted with a substituent.
Furthermore, an ethynyl group, a benzocyclobuten-4′-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrilo group, and an isopropenyl group that serve as a crosslinking point are bonded to the aromatic ring of the acid dianhydride. Even if it introduce | transduces into some or all of a hydrogen atom as a substituent, it can be used. Furthermore, vinylene groups, vinylidene groups, and ethynylidene groups that serve as crosslinking points can be incorporated in the main chain skeleton instead of the substituents, as long as the moldability is not impaired.
For the purpose of introducing branching, a part of the tetracarboxylic dianhydride may be replaced with hexacarboxylic dianhydrides and octacarboxylic dianhydrides.

Further, in order to impart heat resistance to the organic sealing material, a dicarboxylic acid anhydride or a monoamine compound may be included as a terminal blocking agent when synthesizing the polyimide compound and the polyamic acid compound. By sealing the terminal of the polyimide compound with a dicarboxylic acid anhydride or a monoamine compound, the polyimide compounds of the above formulas 2 and 3 can be obtained.
Specific examples of the dicarboxylic acid anhydride that can be used as the end-capping agent include phthalic acid anhydride, 2,3-benzophenone dicarboxylic acid anhydride, 3,4-benzophenone dicarboxylic acid anhydride, 2,3- Dicarboxyphenyl phenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyl dicarboxylic acid anhydride, 3,4-biphenyl dicarboxylic acid anhydride, 2,3-dicarboxyphenyl phenyl sulfone anhydride 3,4-dicarboxyphenyl phenyl sulfone anhydride, 2,3-dicarboxyphenyl phenyl sulfide anhydride, 3,4-dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic acid anhydride, 2, 3-Naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarbo Acid anhydride, 1,2-anthracene dicarboxylic acid anhydride, 2,3-anthracene dicarboxylic acid anhydride, 1,9-anthracene dicarboxylic acid anhydride. These dicarboxylic acid anhydrides may be substituted with groups that are not reactive with amine compounds or tetracarboxylic dianhydrides. These can be used alone or in admixture of two or more. Of these aromatic dicarboxylic anhydrides, phthalic anhydride is preferably used.

  Specific examples of the monoamine compound that can be used as a terminal blocking agent include the following. Aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,6-xylidine, 3,4-xylidine, 3,5-xylidine, o-chloroaniline, m-chloroaniline, p- Chloroaniline, o-bromoaniline, m-bromoaniline, p-bromoaniline, o-nitroaniline, p-nitroaniline, m-nitroaniline, o-aminophenol, p-aminophenol, m-aminophenol, o- Anisidine, m-anisidine, p-anisidine, o-phenetidine, m-phenetidine, p-phenetidine, o-aminobenzaldehyde, p-aminobenzaldehyde, m-aminobenzaldehyde, o-aminobenzonitrile, p-aminobenzonitrile, m -Aminobenzonitrile, 2-aminobiphenyl , 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenylphenyl ether, 3-aminophenylphenyl ether, 4-aminophenylphenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-amino Phenylphenyl sulfide, 3-aminophenylphenyl sulfide, 4-aminophenylphenylsulfide, 2-aminophenylphenylsulfone, 3-aminophenylphenylsulfone, 4-aminophenylphenylsulfone, α-naphthylamine, β-naphthylamine, 1-amino 2-naphthol, 5-amino-1-naphthol, 2-amino-1-naphthol, 4-amino-1-naphthol, 5-amino-2-naphthol, 7-amino-2-naphthol, 8- Mino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene and the like. Usually, among these aromatic monoamines, derivatives of aniline are preferably used. These can be used alone or in admixture of two or more.

These monoamine compounds and / or dicarboxylic acid anhydrides may be used alone or in combination of two or more. The amount of these end-capping agents used is a monoamine compound (excess component is tetracarboxylic dianhydride) or 1 to several times the difference in the number of moles used between the diamine compound and tetracarboxylic dianhydride, or dicarboxylic anhydride Although it is sufficient if it is a product (excess component is a diamine), it is generally used in an amount of about 0.01 mole of at least one component.
In addition, these monoamine compounds and dicarboxylic acid anhydrides have a structure in which a part of the structure is a vinyl group, acetyl group, ethynyl group, allyl group, cyano group, isocyanate group, nitrilo group, isopropenyl group, vinylene group. , Vinylidene group, ethynylidene group, and benzocyclobuten-4′-yl group may be substituted.

The synthesis reaction of the polyimide compound or polyamic acid compound is usually carried out in an organic solvent. Any organic solvent can be used as the organic solvent used in this reaction as long as there is no problem in producing the polyimide compound and the polyamic acid compound and the polyamic acid compound and the polyamic acid compound thus produced can be dissolved. Specifically, amide solvents, ether solvents, and phenol solvents can be exemplified. More specifically, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N , N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane-bis (2-methoxyethyl) ether, 1, 2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) eth ] Ether, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol , Cresolic acid, o-chlorophenol, m-chlorophenol, p-chlorophenol, anisole and the like, and these can be used alone or in admixture of two or more. In particular, an amide-based solvent is preferable from the viewpoints of solution stability and workability.
The synthesized polyimide compound and polyamic acid compound can be used as an organic sealing material solution described later while being dissolved in these organic solvents. When used in such an embodiment, cresol is preferable as the solvent for the polyimide compound, and N-methylpyrrolidone is preferable as the solvent for the polyamic acid compound. In addition, these organic solvents can be used also as a solvent at the time of using the synthesized polyimide compound and polyamic acid compound as a solution.

  It is also possible to coexist an organic base catalyst in synthesizing the polyimide compound and the polyamic acid compound. As the organic base catalyst, tertiary amines such as pyridine, α-picoline, β-picoline, γ-picoline, quinoline, isoquinoline and triethylamine are used, and pyridine and γ-picoline are particularly preferable. The amount of these catalysts used is 0.001 to 0.50 mol with respect to 1 mol of the total amount of tetracarboxylic dianhydride. Most preferably, it is 0.01-0.1 mol.

  The reaction temperature for synthesizing the polyamic acid compound is -20 to 60 ° C, preferably 0 to 40 ° C. The reaction time varies depending on the type of tetracarboxylic dianhydride to be used, the type of solvent, the reaction temperature, and the like, but is generally 1 to 48 hours, and usually several hours to several tens of hours. In this application, the organic solvent solution containing the polyamic acid compound obtained by such a method is referred to as an organic sealing material solution containing the polyamic acid compound. Since the polyamic acid compound is a precursor of the polyimide compound, the polyamic acid compound thus obtained is then heated and dehydrated at a temperature in the range of 150 ° C. or higher and lower than 400 ° C. to imidize the organic system. Used as a dressing.

Moreover, the reaction temperature at the time of synthesize | combining a polyimide compound is 100 degreeC or more, Preferably it is 150-300 degreeC, and it is common to carry out, extracting the water produced by reaction. Prior to imidization, it is possible to first synthesize the precursor polyamic acid compound at a low temperature of 100 ° C. or lower and then increase the temperature to 100 ° C. or higher to imidize, but it is simply tetracarboxylic dianhydride. And diamine compound can be mixed and then imidized by immediately raising the temperature to 100 ° C. or higher in the presence of an organic base. The reaction time varies depending on the type of tetracarboxylic dianhydride used, the type of solvent, the type and amount of the organic base catalyst, the reaction temperature, etc., but as a guide, the distilled water reaches almost the theoretical amount (usually Is not recovered, so the recovery rate is 70 to 90%.) Usually, the reaction takes several hours to 10 hours. In this case, the water generated by the imidization reaction is generally effective by adding an azeotropic agent such as toluene to the reaction system and removing the water by azeotropic distillation. Alternatively, after first synthesizing the polyamic acid as a precursor, it is possible to chemically imidize using an imidizing agent such as acetic anhydride. In the present application, an organic solvent solution containing a polyimide compound obtained by such a method is referred to as an organic sealing material solution containing a polyimide compound. The organic sealing solution containing the polyimide compound has good storage stability, and is applied to the sealing surface of the envelope component made of glass, dried by heating, and then fired at a relatively low temperature and low pressure. Even if baked, sufficient 90 ° sealing peel strength can be obtained. Here, the drying temperature varies depending on the boiling point of the solvent and cannot be specified, but is usually 100 to 300 ° C. On the other hand, as described above, the sealing material is fired at a temperature in the range of 300 ° C. or more and less than 400 ° C.
The polyimide compound may be used after being formed into a film by a known method, not as a solution dissolved in an organic solvent.

  In addition to the above components, a diaminosiloxane compound may be included in the organic sealing material in order to improve the sealing property of the organic sealing material (Japanese Patent Laid-Open Nos. 5-74245, 5-98233, 5- 98234, 5-98235, 5-98236, 5-98237, 5-112760, etc.). The diaminosiloxane is represented by the above formulas 1 to 3 or the above formula 20 (where X is a formula 8). Therefore, when diaminosiloxane is used in combination, as the polyimide compound and the polyamic acid compound, those in which Formula 1 to Formula 3 or Formula 20 in which X is Formula 4 to Formula 7 are used. Diaminosiloxane is used in an amount of 0.10 mol or less with respect to 1 mol of the polyimide compound having the structure of Formulas 1 to 3 or the polyamic acid compound of Formula 20. If the diaminosiloxane is 0.1 mol or less, the heat resistance inherent in the organic sealing material is not impaired, and there is a problem in storage stability such that the organic sealing material solution causes layer separation. It does not occur.

In general, logarithmic viscosity is used as an index of the molecular weight of the polyimide compound. The logarithmic viscosity of the polyimide compound of the present invention is 0.01 to 5.0 at a concentration of 0.5 g / dL at 35 ° C. in a mixed solvent of p-chlorophenol and phenol (90:10), preferably 0. .10 to 0.50.
The molecular weight of the polyamic acid compound can be measured by gel permeation chromatography (GPC), and the polyamic acid of the present invention has a mass average molecular weight of 4,000 to 30,000, preferably 5,000 to 15,000.

In addition, these organic sealing materials can be used by mixing a coupling agent, an inorganic filler and the like according to the purpose.
A coupling agent is used in order to improve sealing property, and the usage-amount is 0.1 mass%-5 mass% in an organic type sealing material. By using 0.1% by mass or more, high sealing properties can be obtained. Moreover, it becomes possible to maintain heat resistance by setting it as 5 mass% or less. Already known coupling agents can be used as usable coupling agents. Specific examples include trialkoxysilane compounds and methyl dialkoxysilane compounds. More specifically, γ-glycidoxypropyl methyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- Aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, N-aminoethyl-γ-iminopropylmethyldimethoxysilane, N-aminoethyl-γ- Iminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, isocyanate propylmethyldie Toxisilane, γ-isocyanatopropyltriethoxysilane and the like can be mentioned.

  The inorganic filler can be used for the purpose of adjusting the viscosity of the solution, reducing the thermal stress of the fired body, etc., and can be selected from known inorganic compounds, and is not particularly limited. Calcium, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, silicon dioxide, potassium titanate, kaolin, talc, asbestos powder, quartz powder, mica And glass fiber.

The method for sealing the envelope constituent member of the image display device with the organic sealing material described above may be performed in the same procedure as the method using the conventional glass frit. That is, an organic sealing material solution containing a polyimide compound or polyamic acid is applied to the sealing surface of the envelope component member, or an organic sealing material film made of a polyimide compound is attached to the sealing surface, Drying or pre-baking at a low temperature (150 to 200 ° C.), and then bonding the sealing surfaces together, a temperature higher than the above-described temperature, specifically, a temperature range of 300 ° C. or more and less than 400 ° C. for 10 to 500 minutes. More preferably, the envelope constituent members are sealed together by performing main firing in a temperature range of 330 ° C. or higher and lower than 400 ° C. for 10 to 300 minutes, more preferably 10 to 60 minutes. Then, in order to make the inside into a high vacuum, the vacuum envelope of the image display device is manufactured by evacuating at a high temperature of 200 to 330 ° C.
Since the organic sealing material of the present invention has a firing temperature of less than 400 ° C., problems such as thermal deformation of the metal member of the image display device when the sealing material is used as a conventional frit glass are solved. . In addition, since the organic sealing material of the present invention has a bending strength at 220 ° C. of the fired body of 30 MPa or more, the vacuum stress and heat applied in the high-temperature evacuation process of the vacuum envelope of the image display device. The sealing part of the vacuum envelope has sufficient strength against the stress, and the problem of cracking of the sealing part in the manufacturing process of the image display device is solved.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.
(Synthesis Example 1)
In a vessel equipped with a stirrer, a reflux condenser and a nitrogen introduction tube, 36.1 g (0.098 mol) of 4,4′-bis (3-aminophenoxy) biphenyl and 0.496 g (0.002 mol) of a diaminosiloxane compound [Toray Dow Corning Silicone Co., Ltd .; product name BY16-871] and N-methyl-2-pyrrolidone 225 g were charged and pyromellitic dianhydride 9.60 g (0.044 mol) in a nitrogen atmosphere. ), 3.95 g (0.044 mol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, added in portions, paying attention to the rise in solution temperature, and stirred at room temperature for about 20 hours. . Thereafter, 7.11 g (0.048 mol) of phthalic anhydride is added and stirred for 5 hours to obtain polyamic acid (1).

(Synthesis Example 2)
The amount of pyromellitic dianhydride in Synthesis Example 1 is 10.25 g (0.047 mol), and the amount of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride is 13.83 g (0 0.047 mol), and polyamic acid (2) is obtained in the same manner except that the amount of phthalic anhydride is changed to 1.63 g (0.011 mol).
(Synthesis Example 3)
A vessel equipped with a stirrer, a reflux condenser and a nitrogen introduction tube was charged with 38.44 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene, and 2,2 ′, 3 in a nitrogen atmosphere. , 3′-benzophenone ditetracarboxylic dianhydride 29.00 g (0.09 mol) is added in portions while paying attention to an increase in the solution temperature, and stirred at room temperature for 20 hours to obtain polyamic acid (3).
(Synthesis Example 4)
The polyamic acid (1) obtained in Synthesis Example 1 was reacted at 200 ° C. for 3 hours, and then cooled to room temperature. After adding 225 g of methyl ethyl ketone, filtration is performed to obtain polyimide (1).

Example 1
(1) Bending strength of sealing part An organic sealing material solution containing polyamic acid (1) in cresol at a concentration of 15% by mass was applied to the sealing end face of the funnel part of a 25-inch CRT vacuum envelope. After drying at 200 ° C. for 1 hour, the image display part is set and baked at 375 ° C. for 60 minutes to obtain a sealed part. After firing, the sealing part is cut to prepare a sample having a width of 5 mm and a length of 60 mm, and a four-point bending strength test is performed at 220 ° C. by a method according to JIS R1601. The results are shown in Table 1.
(2) Flexural modulus of sealing material Polyamic acid (1) is dried at 200 ° C. for 1 hour and then fired at 375 ° C. for 60 minutes to obtain an organic sealing material film (thickness 0.1 mm). The resulting film is measured for elastic modulus at 220 ° C. using a dynamic viscoelasticity measuring device (DMS: Dynamic Mechanical Spectrometer) (DMS110 manufactured by Seiko Instruments Inc.). The results are shown in Table 1.

(3) Mass ratio during heating at 400 ° C. A certain amount of polyamic acid (1) was collected in a thermal mass differential thermal analysis (TG-DTA) measurement cell (TG / DTA6200 manufactured by Seiko Instruments Inc.) After drying at 200 ° C for 1 hour, baking is performed at 375 ° C for 60 minutes. After cooling to room temperature, TG measurement is performed under conditions where the temperature is raised from room temperature to 550 ° C. at 10 ° C./min. The value obtained by dividing the mass m ₄₀₀ at 400 ° C. by the mass m ₂₀ at 20 ° C. (m ₄₀₀ / m ₂₀ ) is the mass ratio upon heating at 400 ° C. The results are shown in Table 1.
(4) Minimum viscosity in a temperature range of 300 ° C. or higher and lower than 400 ° C. The polyamic acid (1) is dried at 200 ° C. for 1 hour and then calcined at 375 ° C. for 60 minutes. After cooling to room temperature, it is processed into a predetermined dimension, and the minimum viscosity in a temperature range of 300 ° C. or higher and lower than 400 ° C. is measured by a parallel plate method. The results are shown in Table 1.

(5) Electrical breakdown strength On the glass piece (60 mm × 30 mm × 5 mm) cut out from the funnel part of the 25 type CRT vacuum envelope, the organic sealing material solution of (1) is applied at 200 ° C. After drying for 1 hour, a glass piece (60 mm × 30 mm × 5 mm) cut out from the glass panel portion is placed and baked at 375 ° C. for 60 minutes. Table 1 shows the dielectric breakdown strength as a value obtained by dividing the voltage when a DC voltage is applied and boosted on both sides of the sample piece sealing part after firing and the voltage is broken by the thickness of the glass.
(6) Water pressure resistant strength A 25-inch CRT vacuum envelope is manufactured in the same procedure as in (1), and a pressure difference due to water is continuously applied to the inside and outside of the vacuum envelope. Measure the pressure difference when the breaks. When broken from the sealed portion, the value is defined as the water pressure resistance, and the results are shown in Table 1.
(7) Display characteristics A 25-inch CRT having the structure shown in FIG. 1 is manufactured in the same procedure as (1), and the image display characteristics are visually evaluated. The results are shown in Table 1. The symbols shown in Table 1 mean the following.
○: No problem in display characteristics Δ: Some problems in display characteristics ×: Problems in display characteristics (8) Measuring method of glass transition temperature Polyamide acid (1) is dried at 200 ° C. for 1 hour and then at 375 ° C. for 60 minutes. Bake. A certain amount of the obtained polyamic acid (1) is collected in a cell of a differential scanning calorimeter (DSC) (DSC6200 manufactured by Seiko Instruments Inc.), and the temperature is increased from room temperature to 450 ° C. at a rate of 8 ° C./min. Measure under the conditions to be used. The endothermic peak is read from the obtained DSC curve and indicated as Tg.

(Example 2 to Example 4)
In the same manner as in Example 1, the tests (1) to (7) are carried out using each of polyamic acid (2), polyamic acid (3) and polyimide (1) instead of polyamic acid (1). . The results are shown in Table 1.

(Comparative Examples 1-4)
The same tests (1) to (7) as in Example 1 are performed with the sealing materials and firing conditions shown in Table 1. The results are shown in Table 1. The sealing materials used in Comparative Examples 1 to 4 are as follows.
Epoxy resin: Structbond EH-454 (Mitsui Chemicals)
Polyamic acid (4): LARK-TPI (Mitsui Chemicals)
Polybenzimidazole: PBI MR Solution (Hoechst Industry)

  As is clear from Table 1, the vacuum envelope for CRT sealed at a temperature of less than 400 ° C. using the organic sealing material of the present invention having a bending strength at 220 ° C. of the fired body of 30 MPa or more. Has excellent water pressure resistance. Further, the CRT using the vacuum envelope has excellent display characteristics. In contrast, a vacuum envelope sealed at a temperature of less than 400 ° C. using conventional frit glass has a low bending strength at 220 ° C., which causes cracking problems in the high-temperature vacuum exhaust process. There is a fear. Moreover, the water pressure resistance of the vacuum envelope is extremely low, which is not a practical level. In general, the water pressure resistance of the vacuum envelope is required to be 0.25 MPa or more, and preferably 0.3 MPa or more. In addition, the sealed vacuum envelope using an organic sealing material whose bending strength at 220 ° C. of the fired body is less than 30 MPa has a bending strength of the sealing portion during the high-temperature vacuum exhaust process. This is sufficient and may cause a cracking problem at the sealing portion. Moreover, in the comparative example 1 which uses an epoxy resin as a sealing material, the mass ratio at the time of 400 degreeC heating is very small, and it can confirm that the sealing material has decomposed | disassembled by the considerable quantity in the high temperature exhaust process. . Further, the image display devices of Comparative Examples 1 to 4 have a problem in display characteristics. Furthermore, the vacuum envelopes of Comparative Examples 3 and 4 have extremely low water pressure resistance and are not at a practical level.

FIG. 1 is a partially cutaway side view of an embodiment of an image display device of the present invention, and the image display device is configured as a CRT. FIG. 2 is a partially cutaway side view of another embodiment of the image display device of the present invention, the image display device being configured as a typical FED.

Explanation of symbols

1, 1 ': Image display device 11: Vacuum envelope (glass bulb)
11 ': Vacuum envelope 13: Phosphor 14: Aluminum film 15: Shadow mask 16: Electron gun 17: Explosion-proof reinforcement band 18: Stud pin 2: Image display panel 2': Image display panel (front panel)
21: Image display area 22: Skirt portion 3: Glass funnel portion 3 ′: Rear panel portion 31: Neck portion 4: Outer frame 5: Organic sealing material layer 61: Cathode 62: Electrolytic emission cold cathode 63: Gate electrode 64 : Insulating layer 65: Anode 66: Phosphor pixel

Claims (17)

A vacuum envelope formed by sealing an envelope constituent member including at least an image display unit made of glass via a sealing material layer,
The sealing material layer includes an organic sealing material layer obtained by firing an organic sealing material,
The bending strength of a sealing portion composed of the organic sealing material layer and an envelope constituent member sealed via the organic sealing material layer is 30 MPa or more at 220 ° C. A vacuum envelope for an image display device.   The vacuum envelope for an image display device according to claim 1, wherein the electrical breakdown strength of the sealing portion is 3 kV / mm or more. The image display device is a cathode ray tube,
The vacuum envelope for an image display device according to claim 1, wherein an electric breakdown strength of the sealing portion is 15 kV / mm or more.   4. The vacuum envelope for an image display device according to claim 1, wherein the organic sealing material layer does not substantially contain lead.   An image display device comprising the vacuum envelope for an image display device according to claim 1. An organic sealing material for sealing an envelope constituent member constituting a vacuum envelope of an image display device,
The organic sealing material has a minimum viscosity of 10 ³ Pa · s or less in a temperature range of 300 ° C. or more and less than 400 ° C.,
The fired body of the organic sealing material is characterized in that when the mass at 20 ° C. is m ₂₀ and the mass at 400 ° C. is m ₄₀₀ , 0.99 <m ₄₀₀ / m ₂₀ ≦ 1.00. A sealing material for an image display device.   The sealing material for an image display device according to claim 6, wherein a glass transition temperature of the fired body of the organic sealing material by a differential scanning calorimeter (DSC) is 175 ° C or higher.   The sealing material for an image display device according to claim 6 or 7, wherein a bending elastic modulus at 220 ° C of the fired body of the organic sealing material is 100 MPa or more.   The sealing material for an image display device according to claim 6, comprising a polyimide compound or a polyamic acid compound as a main component.   The imide group content ratio (imide group molecular weight / polyimide molecular weight) in the polyimide compound or the amide group content ratio (amide group molecular weight / polyamic acid molecular weight) in the polyamic acid compound is in the range of 10 to 31%. Item 10. A sealing material for an image display device according to Item 9. The sealing material for an image display device according to claim 9 or 10, comprising at least one of polyimide compounds having a structure represented by the following formulas 1 to 3 as a main component.

(Wherein X is the main skeleton of the diamine compound, X ′ is the main skeleton of the monoamine compound, Y is the main skeleton of the tetracarboxylic dianhydride, and Y ′ is the main skeleton of the dicarboxylic acid anhydride. is there.) In the polyimide compound of Formula 1 to Formula 3, when X is any one selected from the group consisting of Formulas 4 to 8, Y is selected from the group consisting of Formulas 9 to 14 below. Or one,
When the X is the following formula 15, the Y is the following formula 16 or the formula 17,
The sealing material for an image display device according to claim 11, wherein when X is a formula 18 below, the Y is a formula 19 below.

(In the above formula, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) _2. N is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.) The sealing material for an image display device according to claim 9 or 10, comprising a polyamic acid compound having a structure represented by the following formula 20 as a main component.

In the formula 20, when X is any one selected from the group consisting of the following formulas 4 to 8, Y is any one selected from the group consisting of the following formulas 9 to 14.
When X is the following formula 15, Y is the following formula 16 or formula 17,
When X is the following formula 18, Y is the following formula 19.

(In the above formula, each R is independently selected from the group consisting of —, —O—, —CO—, —SO ₂ —, —S—, —CH ₂ — and —C (CH ₃ ) _2. N is each independently 0 to 7, and Z is each independently CH ₃ or a phenyl group.)   A vacuum envelope for an image display device, wherein the envelope constituting member is sealed with the sealing material for an image display device according to any one of claims 6 to 13.   The image display apparatus provided with the vacuum envelope for image display apparatuses of Claim 14.   An organic sealing agent mainly composed of a polyimide compound or a polyamic acid compound or a solution thereof is applied to a sealing surface of an envelope constituent member constituting the vacuum envelope, and then a range of 300 ° C. or higher and lower than 400 ° C. A method for sealing a vacuum envelope for an image display device, wherein the organic sealing agent is baked and solidified by heating to a temperature of 2 to seal the envelope constituent member.   The method for sealing an image display device according to claim 16, wherein the organic sealant is the sealant for an image display device according to any one of claims 10 to 13.

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