JPH0427110A - Heat-resistant capacitor - Google Patents

Abstract

PURPOSE:To achieve improved heat resistance, mechanical characteristics, chemical characteristics, surface characteristics, and economy by enabling a title item to be made of a blend resin with an aromatic series polyamide soluble resin and by using a specific film as a dielectric. CONSTITUTION:A film which consists of a blend resin of an aromatic series polyamide and a soluble resin and where an amount of the aromatic series polyamide ranges from 5 wt.% to 90 wt.% is used as a dielectric. For example, each blend stock solution of the aromatic series polyamide and soluble resin is individually adjusted and the stock solutions are blended together. A film- forming stock solution is casted in film shape by a doctor knife, a cap etc. and then is dried for a certain amount of time. The dried film is released from a support, is dipped into a water medium, or the medium is atomized, thus enabling an inorganic salt and a solvent medium to be extracted. A metal thin film is formed on the film. The metallized film is wound or laminated. For example, two film, where a single surface is metallized, are overlapped, wound, or laminated. An external electrode and an exterior finish are provided to it for forming a capacitor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat-resistant capacitor, and more specifically, to a heat-resistant capacitor that uses a film made of a resin that is a blend of a resin with low heat resistance and an aromatic polyamide. This relates to heat-resistant capacitors.

[Prior Art] Film materials used as dielectrics in film capacitors generally include polyethylene terephthalate and polypropylene. In recent years, electrical equipment has become smaller and the parts used in it have also become smaller, but the same is true for capacitors. , polycarbonate, etc. are also beginning to be used for some applications. In addition, aromatic polyamides with even higher heat resistance are being considered.

[Problems to be solved by the invention] However, recent manufacturing conditions have become increasingly severe, and even polyphenylene sulfide is no longer usable, and amorphous polymers such as polycarbonate have high glass transition points and are difficult to use electrically. Although it has excellent characteristics and humidity characteristics,
It has the disadvantage of poor mechanical properties at high temperatures, which is typical of amorphous polymers.

On the other hand, aromatic polyamide is known as a heat-resistant film, and although it has good heat resistance and mechanical properties, it not only increases costs due to poor productivity, but also has humidity characteristics that are fatal for film capacitors. It has the disadvantage of poor electrical characteristics.

The present invention improves these problems and improves heat resistance, mechanical properties,
The objective is to provide a heat-resistant capacitor using a film with excellent chemical properties (mainly humidity properties), surface properties, and economical efficiency (cost).

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a blend resin of an aromatic polyamide and a soluble resin, and the amount of the aromatic polyamide is 5% or more by weight or more than 90% by weight of the blend resin. %
This is a heat-resistant capacitor characterized by using a film within the following range as a dielectric material.

The aromatic polyamide of the present invention preferably contains 50 mol% or more of one or more repeating units represented by the general formula, more preferably 70 mol% or more.

Here, Ar and Ar2 are composed of one or more types of structures containing at least one aromatic ring, and may have the same composition or different compositions, and representative examples thereof include the following.

()・ten・3・(h cut(arrival)・UX()・◎X−◎−・ @fX−◎−・(σ Also, some of the hydrogens on the rings of these aromatic rings are Halogen groups (especially chlorine), nitro groups, 01-C3 alkyl groups (
In particular, those substituted with substituents such as methyl group) and 01-C3 alkoxy groups are also included. Also, X is -〇-,
-CH2--8O2-, -8-, -co-, etc.

These may be included alone or in copolymerized form.

From the viewpoint of improving heat resistance, which is the objective of the present invention, Ar1
．． Ar2 preferably has a rigid structure with mainly para orientation,
Further, those having a substituent such as a halogen group or an alkyl group on the aromatic ring are more preferable because of their high solubility in solvents and high compatibility with soluble resins. Furthermore, halogen groups are preferred because they improve the humidity characteristics of the resulting film.

In addition, structures in which two aromatic rings are bonded via 0-, -CH2-, -5o2-, -8-CO-, etc. have high solubility in solvents and compatibility with soluble resins. It is also preferable that these are copolymerized, but if the amount is too high, the thermal properties, mechanical properties, and humidity properties will be adversely affected.

That is, Arl : (Ar3), (Ar4)b (Ar5
).

Ar2: (Ar6)d (Ar7)eHowever, a+b
+d+e>0.5 b+e>0.5 C<Q, 4 Ar4, Ar7: An aromatic polyamide in which Ar3 and Ar6 satisfy a group with nuclear substitution (such as halogen) is preferred. In addition, Ar1,
A r 3 , A r 4 , Ar 5 that constitute Ar2
, Ar6, and Ar7 are not particularly limited as long as they satisfy the above formula.

For example, a solution of one or more aromatic polyamides represented by (where p, q are integers of 1 to 4, p+Q≧1) (here, q = an integer of 0 to 4) and a soluble resin is a long solution. The pot life is extremely stable even when stored for a long time, and the resulting film is strong and has good heat resistance and humidity characteristics.

Moreover, the soluble resin of the present invention refers to one or more resins that dissolve 1% by weight or more in the solvent that dissolves the aromatic polyamide described above, and is not particularly limited. As a solvent that dissolves both aromatic polyamide and soluble resin,
Considering ease of handling, organic solvents are preferred, and amide polar solvents such as N-methyl-2-pyrrolidone, dimethylacetamide, hexamethylene phosphoramide, dimethylformamide, and dimethylimidazolidinone, and dimethylsulfone are preferred. N-
Methyl-2-pyrrolidone and mixtures of N-methyl-2-pyrrolidone and other amide polar solvents are preferred. When these solvents are used, particularly preferred are polycarbonate, polyvinylidene fluoride, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyether sulfone, polysulfone, polyarylate, polysulfide sulfone, polyetherimide, etc., which have good mechanical properties at high temperatures. Non-grade resins with remarkable improvement and excellent humidity characteristics, such as polycarbonate, polyether sulfone,
More preferred are polysulfone, polyarylate, and polysulfide sulfone. In particular, a resin having both the basic skeleton A and the structure of //C=O has very good compatibility with the aromatic polyamide, so it can be obtained by dissolving the aromatic polyamide and the soluble resin in the above solvent. Blended solutions are more preferred because they have excellent long-term storage stability and provide films with excellent mechanical properties and transparency. Examples include polycarbonate and polyarylate, with polycarbonate being more preferred from the economic point of view. The basic skeleton A may have a substituent, such as a halogen group. Further, in the blend resin of the aromatic polyamide and soluble resin, a resin other than the resin used as the third component is preferably 40% by weight or less, more preferably 30% by weight or less of the soluble resin, and Preferably, it may be added in an amount of 20% by weight or less. The other resin is preferably an aromatic polyamide having a structure different from that of the blended aromatic polyamide, or a soluble resin different from the soluble resin used. For example, when polycarbonate is used as the soluble resin, adding polyethersulfone, polysulfone, etc. to it improves mechanical properties. In addition to the above solvents, good solvents for soluble resins such as dioxane, tetrahydrofuran, methylene chloride,
Chloroform, 1,1,2-trichloroethane, tricrene, acetone, toluene, etc. are used within a range that does not prevent the soluble resin and aromatic polyamide from being compatible, preferably within 20% by weight of the total solvent amount, more preferably It may be contained within 15% by weight.

A film made of a blend resin can be obtained by solution casting the blend solution described above.

The amount of aromatic polyamide in the film of the present invention needs to be in the range of 5% to 90% by weight of the blend resin. When the amount of aromatic polyamide is less than this range, the effect of improving heat resistance is no longer observed, and the mechanical properties at high temperatures are extremely deteriorated. Preferably it is 7% by weight or more, more preferably 10% by weight or more. Furthermore, if the amount of aromatic polyamide is greater than this range, there will be no economic advantage and the humidity characteristics will deteriorate. Preferably 7
It is 0% by weight or less, more preferably 50% by weight or less.

Further, the center line depth Rp of the surface of the film of the present invention is 10 to
Preferably it is 5000 nm. If it is less than IQnm, the handling properties of the film deteriorate, the surface is damaged by rubbing between the films, and insulation defects increase. This increases the failure rate of withstand voltage when used as a capacitor, for example.

If it is larger than 5000 nm, the stability of the dielectric properties of the same film deteriorates, and for example, when used in a capacitor, variations in capacitance increase. More preferably 10
~2000 nm.

Furthermore, the average cross-sectional flatness P of the surface projections of the film of the present invention
is preferably 0.005 to 0.3.

If it is less than 0.005, the protrusions are too flat, the handling of the film deteriorates, the surface is damaged by rubbing between the films, and insulation defects increase. This increases the failure rate of withstand voltage when used as a capacitor, for example. If it is larger than 0.3, the protrusions will be too sharp, and the dielectric properties of the same film will become less stable due to scraping of the protrusions, and for example, when used in a capacitor, variations in capacitance will increase. More preferably, it is 0.05 to 0.15.

Moreover, Ra (center line average roughness) of the surface of the film of the present invention
is preferably 10 to 500 nm, more preferably 30 to 500 nm.
It is 300 nm.

Furthermore, Rz (10 point average roughness) of the surface of the film-like material of the present invention
is preferably 50 to 5000 nm, more preferably 10
It is 0 to 3000 nm. This case is particularly preferable because the above-mentioned effects are even more pronounced.

In addition, in order to achieve the above surface roughness, inorganic or organic fine particles are added, and the amount (preferably 0.05 to 10% by weight, more preferably 0.1 to 5% by weight) and particle size ( The average particle size is preferably 0.005 to 1.0 μm, and 0.01 to 0
．． (more preferably 8 μm), or adjusting the stretching temperature and stretching ratio.

The film of the present invention is under load in at least one direction (0,5
The thermal dimensional change rate at 250°C (kg/mm") is preferably 50% or less. If it is greater than 50%, it cannot withstand use in cases where tension is applied at high temperatures, such as in thermal transfer applications. More preferably 40% or less, more preferably 2
It is 0% or less.

The heat shrinkage rate at 250° C. in at least one direction of the film obtained in the present invention is preferably 20% or less. More preferably it is 10% or less, and still more preferably 5% or less.

If it exceeds 20%, the dimensional stability will be poor and it will not be practical in the fields of thermal transfer applications, flexible circuit boards, and capacitor applications, for example. Further, the heat shrinkage rate at 200° C. in at least one direction is preferably 10% or less, more preferably 5% or less. Additionally, at least 300 in one direction
The heat shrinkage rate at °C is preferably 30% or less, more preferably 20% or less. In addition, the coefficient of thermal expansion in at least one direction is
5 X 10-5/'C or less is preferable, and 4 X 10
-5/°C or less is more preferable. If it exceeds 5×10 −5 /° C., it cannot withstand use in flexible circuit board applications.

The moisture absorption rate of the film is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less. If it is more than 5%, the dimensional change due to moisture absorption becomes large and it is not suitable for practical use. Further, the humidity expansion coefficient in at least one direction is 5X
10-5/%RH or less is preferable. 4X10-5/%R
H or less is more preferable.

The film of the present invention has a breaking elongation of 10 in at least one direction.
% or more is preferable. More preferably it is 15% or more, and still more preferably 20% or more. If it is less than 10%, the film will break during handling or processing, making it unusable. Also, the strength in at least one direction is 5 kg
/ mm 2 or more is preferable, more preferably 7 k
g/mm2 or more, more preferably 9 kg/mm
mm 2 or more. The Young's modulus in at least one direction is preferably 150 kg/mm2 or more, more preferably 200 kg/mm2 or more.

The thickness of the film of the present invention is preferably 0.2 to 200 μm, more preferably 1 to 50 μm. Moreover, the density of this film is preferably 1.0 to 1.5 g/am, more preferably 131 to 1.4 g/cm'.

The dielectric constant (1kHz) of the film of the present invention is:

2 to 7 are preferred. In addition, the dielectric voltage contact (1kHz) is 3
% or less is preferable. More preferably, it is 2% or less.

Furthermore, the tear resistance of the film of the present invention in at least one direction is preferably 0.05 kg/μm or more.

If it is less than this, the film will break during handling or processing, making it unsuitable for practical use. More preferably 0.1 kg/μm or more, even more preferably 0.3 k
g/μm or more.

Next, the film manufacturing method of the present invention will be explained.
It is not limited to this.

The aromatic polyamide of the present invention is obtained by reacting a diisocyanate and a dicarboxylic acid, or a diacid chloride and a diamine. In the case of diacid chloride and diamine, N-
It is synthesized by solution polymerization in an amide polar solvent such as methyl-2-pyrrolidone or dimethylacetamide, or by interfacial polymerization using an aqueous medium. Diacyl chloride and diamine are mixed in a low moisture amide polar solvent at low temperature (usually 50%
℃ or lower, preferably 30℃ or lower) for 1 to 2 hours to polymerize. The order of adding the monomers is not particularly limited. Hydrochloric acid generated after polymerization is neutralized with an inorganic alkali or organic neutralizing agent. Further, the reaction between the diisocyanate and the dicarboxylic acid is carried out in an amide polar solvent in the presence of a catalyst, usually at a high temperature (50 to 200°C). These polymer solutions may be used as they are as a stock solution for blending, or the polymer may be isolated once and then redissolved in a solvent to prepare a stock solution for blending. Inorganic salts such as calcium chloride, magnesium chloride, etc. may be added to the blending stock solution as a solubilizing agent.

In order to improve the mechanical properties of a heat-resistant film, it is necessary to keep the molecular weight of the polymer above a certain level, and it is convenient to express this in terms of intrinsic viscosity (ηInh). That is, the intrinsic viscosity is preferably 1.0 to
10.0, more preferably 1.5 to 7.0.

Methods for blending the above-mentioned aromatic polyamide and soluble resin include methods of separately preparing blend stock solutions of the aromatic polyamide and soluble resin and blending the stock solutions, and a method of blending the stock solutions of the aromatic polyamide and the soluble resin. Examples include a method in which the above-mentioned aromatic polyamide is polymerized and the polymerization and blending are performed simultaneously.

In particular, when blend stock solutions of aromatic polyamide and soluble resin are prepared separately and the stock solutions are blended, the temperature of the solution is 25 to 100 °C, preferably 30 to 8 °C.
Stirring is preferably performed at 0°C for 30 minutes or more. If the temperature is lower than this or the stirring time is not sufficient, the surface may become rough when formed into a film. As mentioned above, in order to control the surface roughness of the film, inorganic,
Add organic particulates. The apparent intrinsic viscosity obtained from the membrane-forming stock solution thus obtained is preferably 0.1 to 8.0, more preferably 0.2 to 5.0. The solution viscosity can be freely selected, but from the viewpoint of flowability, it is preferably 5 to 50,000 poise/30°C, and more preferably 10 to 20,000 poise. The resin concentration is preferably 1 to 50%, and 5 to 30%.
is even more desirable.

This film-forming stock solution is made into a film by the following method.

First, in the wet-dry method, a film is cast onto a support using a doctor knife, a nozzle, etc., and the temperature is usually 50 to 250°C.
It is dried for a certain period of time, preferably at 60 to 200°C. Below 50°C, the evaporation rate of the solvent is slow;
If the temperature exceeds ℃, bumping of the solvent occurs and the quality of the film deteriorates. The dried film is peeled off from the support,
The inorganic salt and solvent are extracted by immersion or spraying into an aqueous medium. The aqueous medium is a liquid whose main component is water, which is a poor solvent for polymers but has an affinity for inorganic salts and amide polar solvents. Examples include water alone, a mixture of water and an amide polar solvent constituting the stock solution, and a mixture of water and ethylene glycol, acetone, or lower alcohol, but at least 50% of the water is desalted or This is desirable in consideration of desolvation speed and solvent recovery. Further, the temperature of the wet bath is usually 5 to 90°C. In the first stage of the wet process, inorganic salts and amide polar solvents that serve as dissolution aids are extracted, but the amount of inorganic salts remaining in the film immediately after the first stage of the wet process is preferably 3% or less per polymer, more preferably. 1% or less is preferable.

Although the residual rate of the amide polar solvent is not particularly defined, it is advantageous to extract as much as possible in consideration of solvent recovery. During the first wet process, the film is in a swollen state with an aqueous medium, so it is easy to stretch within the wet temperature range, and in order to improve the mechanical properties of the final film, the film is generally stretched at 1° to 5°C during the process.
Stretched 0 times in the machine direction. After the first wet process, the film is heated to evaporate the aqueous medium and the amide polar solvent. In this heating step, the temperature is finally 100°C or higher, preferably 200°C or higher and 500°C or lower, but after drying the water at 50 to 100°C (the water content is 20% by weight or less based on the film weight). Heating at the above-mentioned temperature is preferred because it makes it easier to obtain a film having the thermal and mechanical properties of the present invention.

In addition, in the heating process, it is stretched 1.01 to 5.0 times in the transverse direction, but once at 100 to 200°C, it is stretched by 1.05 to 1.2 times.
A film having the surface characteristics of the present invention can easily be obtained by performing two-stage stretching, ie, stretching at 200 to 500° C. after double stretching. . There is no problem in relaxing if necessary.

Next, the wet method is a method in which the material is introduced into an aqueous medium (containing alcohol such as methanol or ethanol, or only alcohol) directly from the die or by forming the film onto a support. It is. Because it contains a large amount of amide-based polar solvents, rapid substitution of inorganic salts and amide-based polar solvents occurs in the aqueous medium, making it more likely that voids or surface roughness will occur in the final film. Inorganic salts, such as calcium chloride, lithium chloride, lithium bromide, etc., may be contained in the aqueous medium as necessary to control the substitution rate, or water tanks may be multi-staged to control the substitution rate. Create a concentration gradient in a mixture of salts, etc. Similar to the wet-dry method, the film may be stretched 1.01 to 5 times in the longitudinal direction in this step. After the first wet process, the film is heated (200 to 500
Two stages of stretching (1.01 to 5.0 times) are carried out in the transverse direction (°C) and in the transverse direction. Before this heating, it is preferable to once dry the moisture at 50 to 100°C, and this is carried out using hot rolls or hot air, and longitudinal stretching by 1.01 to 5 times is also carried out depending on the case.

Next is the dry method. This method is the opposite of the wet method, in that it omits the extraction step, and is only possible when an organic solvent is used and the membrane forming stock solution does not contain an inorganic salt as a solubilizing agent. The stock solution cast onto the support using a doctor knife or a nozzle is dried and peeled off from the support in the same manner as the dry-wet method.
Stretched 1 to 5 degrees 0 times. After completing the first dry process, the film is heated and stretched in the same manner as in the wet-dry process. The film of the present invention can be obtained in the manner described above.

Next, the method for manufacturing the capacitor will be described.

A metal thin film is formed on the film obtained as described above by a method such as vacuum evaporation, plating, sputtering, or ion blasting to obtain a metallized film that will become a capacitor element. Examples of the metal at this time include aluminum, zinc, nickel, nickel-chromium alloy, etc. Among these, aluminum is preferable in terms of vapor deposition properties and characteristics.

Next, the metallized film is wound or laminated to form the capacitor of the present invention. For example, if one side of the film is metallized, two layers are stacked and rolled or laminated, or if the film is metallized on both sides, it is wound or laminated with a non-metalized film to form a capacitor element. Apply an exterior and use it as a capacitor. The capacitance change before and after immersing this capacitor in a 260° C. solder bath for 30 seconds is preferably 10% or less, more preferably 7% or less. In addition, the change in withstand voltage before and after storage in an atmosphere at 150°C for 1000 hours is preferably 10% or less,
More preferably it is 7% or less.

Both cannot be put to practical use outside this range.

[Evaluation method of characteristics] In addition, the method of measuring the characteristics in the examples is as follows.

(1) Intrinsic viscosity (η, .h) Measured using an Ubbelohde viscometer at 0.5 g/100 ml and 30° C. using N-methyl-2-pyrrolidone as a solvent according to the following formula.

(2) Solution viscosity (poise) Measured at a temperature of 30° C. using a rotating B-type viscometer (Tokyo Keiki).

(3) Elongation at break, strength, Young's modulus, F-5 value TR8 type tensile tester, width 10 mm, length 50 mm, tensile speed 3
The measurement was performed under the condition of 00 mm/min.

(4) Thermal shrinkage rate (%) After heating for 10 minutes in an oven set at a predetermined temperature with no load, the product was returned to room temperature, the dimensions were measured, and the dimensions were calculated using the formula below.

X100 (%) (5) Moisture absorption rate (%) The weight of the film was measured after being absolutely dry at 150° C. for 60 minutes and after being left in 75% RH for 48 hours, and calculated using the following formula.

Moisture absorption rate = (75% RH, weight of film after being left for 48 hours - weight of film when completely dry) / (weight of film when completely dry) The film was heated to 150℃ to remove the influence of moisture.
80-150 when heated to ℃ and gradually cooled
Calculated from dimensional changes in the °C range. The amount of dimensional change was measured by a thermomechanical analyzer (TMA).

■ Humidity expansion coefficient (β) In a constant temperature and humidity chamber, read the film length when it reaches equilibrium during dehumidification (approximately 30% RH) and humidification (approximately 80% RH), and read the difference (amount of elongation). It was calculated using the formula below.

ΔH: Humidity difference between humidification and dehumidification (%RH) (8) Rate of thermal dimensional change under load Multiplying the load of 0.5 kg/fIII112 and increasing the temperature to 250°C
The product was placed in an oven for 10 minutes, returned to room temperature, measured, and calculated using the formula below.

X100 (%) (9) Dielectric constant, tanδ Conforms to ASTM-D-150-81.

(2) Centerline average roughness Ra, centerline depth Rp, 10-point average roughness Rz Measured using a high-precision thin film step measuring instrument ET-10 manufactured by Koita Research Institute. The conditions were as follows, and the average value of 20 times was taken as the value.

・Stylus tip radius 20.5μm ・Stylus load: 5mg ・Measurement length: 1mm ・Cutoff value: 0.08mm In addition, center line average roughness Ra, center line depth Rp, 10 point average roughness Rz The definition is, for example, given in "Measurement and Evaluation Method of Surface Roughness" written by Jibu Nara (Sogo Technological Center 1983). It refers to the distance from the highest peak of the extracted part to the center line.

aυ Average cross-sectional flatness P of surface protrusions Measured value of film height using a scanning electron microscope with 2 detection method [ESM-3200, manufactured by Elionix Co., Ltd.] and a cross-sectional measuring device [PMS-1, manufactured by Elionix Co., Ltd.] Image processing device [I BAS2000, Carl Zeiss (
The film is sent to Seiko Co., Ltd., and an image of the protrusions on the film surface is reconstructed on an image processing device.

Next, the protrusion portion is binarized using this film surface protrusion image, and the equivalent circle diameter is determined from the area of each protrusion obtained, and this is taken as the average diameter of the protrusion. Furthermore, the highest value among the binarized individual protrusions is determined as the height of the protrusion, and this value is determined for each protrusion. Change this measurement location 5
00 times, the average value of the ratio of height and average diameter (height/average diameter) of the measured protrusions is calculated as the average cross-sectional flatness P
And so. The magnification of the scanning electron microscope is 10oO~80
Select a value between 00 times.

End tear resistance (kg/μm) Measured in accordance with J I 5-C-2318, thickness 1 μm
Converted to m.

(13 Evaluation of Capacitor Withstand Voltage Defective Rate Manufacture 1,000 capacitors under the same conditions, measure the withstand voltage of each capacitor, calculate the percentage of capacitors that did not reach the specified voltage, and express it in % as the withstand voltage defect rate. In addition, the voltage was applied while increasing at a rate of 100 V/see, and the voltage at which the capacitor was destroyed and a current of 10 mA or more flowed was defined as the withstand voltage.
It was set to 20V per μm.

(b) Evaluation of capacitance variation: 1000 capacitors were manufactured under the same conditions, and the capacitance of each capacitor was measured using an automatic capacitance bridge, and the variation (standard deviation) was expressed in % and was defined as the capacitance variation. . The smaller this value is, the better the stability is.

(Weak Capacitor Characteristics Capacitor characteristics were rated as good (○) if the withstand voltage failure rate and capacitance variation were both 10% or less.

0Q Soldering resistance It was immersed in a solder bath at 260°C for 30 seconds, and the change in capacitance before and after was measured.

Capacity change rate (%) (m Long-term heat resistance) It was stored in an atmosphere at 150° C. for 1000 hours, and the change in withstand voltage before and after was measured.

Withstand voltage change rate (%) [Example] Next, embodiments of the present invention will be explained based on Examples.
It is not limited to this. Note that all parts used in the following examples represent parts by weight, and characteristic values that differ in the vertical and horizontal directions are averaged values.

Example 1 (1) Production of film 70 mo1% of 2-chloroparaphenylenediamine (hereinafter abbreviated as CPA) and 30 mo1% of 4゜4'-diaminodiphenyl ether (hereinafter abbreviated as 4.4DAE),
100 mo1% of 2-chloroterephthalic acid chloride (hereinafter abbreviated as CTPC) and N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) were reacted at 20°C or lower to obtain an NMP solution of aromatic polyamide. This solution was poured into a large amount of water, reprecipitated and dried to obtain a powdery polymer. 20 parts of this polymer was dissolved in 200 parts of NMP, 200 parts of a separately prepared NMP solution containing 30 parts of polycarbonate was added thereto, the mixture was stirred at 40°C for 4 hours, and Thyroid 150 (Fuji Davison Chemical) was added. A blend solution was obtained by adding 0.2% by weight (based on the total amount of polymer). The intrinsic viscosity was 1.1 and the solution viscosity was 530 boids.

This film-forming stock solution was cast onto a stainless steel endless belt and dried with hot air at 160° C. until it had self-supporting properties. The gel film that had achieved self-supporting properties was continuously peeled off from the belt, and then introduced into a water tank, where it was stretched 1.1 times in the longitudinal direction at the same time as the solvent was extracted, and introduced into a stenter. After drying the moisture at 80°C under a stenter at a fixed length and stretching 1.3 times in the transverse direction at 160°C,
Stretched 1.5 times (2 times in total) in the transverse direction at 80°C,
A film with a thickness of 5 μm was obtained. The obtained film is referred to as Film 1, and the elongation at break of this film = 28%, tensile strength: 11 kg/2, Young's modulus: 420 kg/[
II [[12, end tear resistance +0.58 kg/μm,
Heat shrinkage rate at 250°C for 110 minutes = 0.5%, 250°C
Thermal dimensional change rate under load (0.5 kg/anal 2): 17%
, thermal expansion coefficient (α): 2゜3 x 10-5 parts ℃, moisture absorption rate 20.8%, dielectric constant: 3゜2, tan δ: 0.41,
Rp: 1l100n.

Ra: 120nm, Rz: 1200nm, %
P: 0°13, the film was strong and had excellent humidity characteristics, heat resistance, and workability.

(2) Aluminum was vacuum-deposited on the metallized film 1 so that the surface resistance was 2Ω. At that time, it was deposited in a stripe shape with a margin running in the longitudinal direction (the width of the deposited part was 9.0 mm,
Margin width 1. 0mm repetition). Next, insert a blade into the center of the vapor deposition area and the center of each margin to make a slit.
Full width with 0.5mm margin on left or right5.
It was wound up into a 0 mm tape.

(3) Manufacture of the wound body 1 each of the left margin and right margin of the obtained reel
The sheets were stacked one on top of the other and rolled up. At this time, the two films were wound with an offset so that the vapor-deposited portion protruded from the margin portion by 0.5 mm in the width direction.

(4) Manufacture of capacitors Remove the core material from this wound body and heat it at 180℃ for 10 minutes.
It was pressed for 5 minutes at a temperature and pressure of kg/an2. Metallicon was thermally sprayed on both end faces of this to form external electrodes, and lead wires were connected to the metallicon to obtain a wound capacitor. Table 1 shows the evaluation results of this capacitor in terms of solder resistance, long-term heat resistance, capacitance variation, and poor voltage resistance, and it was found to have good capacitor characteristics.

Example 2 CPA70mo 1%, 4.4'-diaminodiphenylsulfone (hereinafter abbreviated as DAS) 30mo1% and CTP
C50mo 1%, terephthalic acid chloride (hereinafter referred to as TPO
A solution of 35 parts of aromatic polyamide obtained by isolation after reaction with 50 mo1% dissolved in 300 parts of NMP, and 100 parts of NMP solution containing 15 parts of polycarbonate.
The parts were blended. Film 2 was produced from this blend solution in the same manner as in Example 1. The obtained film had a thickness of 4 μm, a tensile elongation of 22%, and a tensile strength of
14kg/Nn2, Young's modulus: 430 kg/mm
Two-end tear resistance: 0.44 kg/μm, 250°C, 1
Heat shrinkage rate 20.5% for 0 minutes, under load of 250℃ (0,
5) Thermal dimensional change rate of cg/mm2): 11%, moisture absorption rate =
1.2%, dielectric constant: 3.2, tan δ: 0.38, Rp
: 900 partsm, Ra: 1105n.

The film was strong with Rz: 11000n, P: 0.11, and had excellent humidity characteristics, heat resistance, and workability. Furthermore, when a capacitor was manufactured using this film 2 in the same manner as in Example 1, it had excellent characteristics as shown in Table 1.

Example 3 In the same manner as in Example 1, CPA85mo 1%, 4.
4'-DAE 15mo 1% and CTPCroom.

350 parts of an NMP solution containing 10 parts of aromatic polyamide obtained from a 1% reaction and 40 parts of polyether sulfone was prepared. The solution viscosity was 80 voids at 30°C.

This blend stock solution was made into a width of 10 parts and a slit of 0.1 m.
It was continuously extruded into water from a nozzle of m, stretched 1.05 times in the longitudinal direction in water, dried at 95°C, and then
1.2 times in the lateral direction at 310°C, and 1.2 times in the lateral direction at 310°C.
- A long film 3 was obtained by heating while being stretched 3 times. The obtained film had a thickness of 4 μm and a tensile elongation:
20%, tensile strength: 12kg/M2, Young's modulus: 4
50 kg/mm2, end tear resistance: 0.60 kg/μm, heat shrinkage rate at 250°C for 10 minutes = 0.3%, 25
Thermal dimensional change rate under load at 0℃ (0.5kg/mm2) =
7.1%, moisture absorption rate 20.7%, dielectric constant: 3.0, tan
δ: 0.33, Rp: 980 parts m, Ra: 95 parts m
, Rz: 1l100n.

P: 0.08, the film was strong and had excellent humidity characteristics, heat resistance, and workability. Furthermore, when a capacitor was manufactured using this film 3 in the same manner as in Example 1, it had excellent characteristics as shown in Table 1.

Example 4 In the same manner as in Example 1, CPA100mo1% and CT
500 parts of an NMP solution containing 15 parts of aromatic polyamide (ηlnh: 6.4) obtained from the reaction of 1% PCloomo and 35 parts of polycarbonate was prepared. The solution viscosity was 1000 voids at 30°C. This blend stock solution was continuously extruded into water through a nozzle with a width of 62.0 mm and 1 slit of 0.5 mm, and was
After stretching the film twice and drying water at 95°C, heating was performed while stretching the film 1°2 times in the transverse direction at 150°C and 1.3 times in the transverse direction at 300°C to obtain a long film 4. The obtained film had a thickness of 22 μm, a tensile elongation of 23%, a tensile strength of 21 kg/M2, and a Young's modulus of 650 kg/
mm2, end tear resistance: 0.75 kg/, czm, 2
Heat shrinkage rate at 50°C for 10 minutes = 0.5%, thermal dimensional change rate under load at 250°C (0.5kg/embryo 2) = 1.6%,
Moisture absorption rate = 0.4%, dielectric constant: 3.3, tan δ: 0.4
0, Rp: 1200 nm, Ra: 110 parts m, Rz: 1
The film was strong with a thickness of 150 nm and P: 0.10, and had excellent humidity characteristics, heat resistance, and workability. Furthermore, when a capacitor was produced using this film 4 in the same manner as in Example 1, it had excellent characteristics as shown in Table 1.

Comparative Example 1 Thyroid 1 was added to a chloroform solution of polycarbonate.
When a capacitor was produced by adding 0.2% by weight (based on the amount of polymer) of 50 and forming a film in the same manner as in Example 1, there were no problems with workability or capacitor properties, but the solder resistance and long-term heat resistance were poor. could not be measured because it broke during the measurement, and had poor heat resistance.

Comparative example 2 CPA75mo1%, DAE25mo1% and CTPC1
NMP of aromatic polyamide obtained from 00mo1%
Add 0.1 of Aerosil R972 (Japan Aerosil) to the solution.
A film was formed in the same manner as in Example 1 by adding 8% by weight. Although there were no problems in mechanical properties and workability, when a capacitor was evaluated, the properties were poor as shown in Table 1.

As described above, capacitors made from films outside the scope of the present invention had poor characteristics.

[Effects of the Invention] The film made of the blended resin of aromatic polyamide and soluble resin obtained by the present invention does not flow even at temperatures above the softening pour point of the soluble resin, has a low thermal shrinkage rate at high temperatures, and has good dimensional stability. The characteristics of capacitors obtained from this film are very good. In addition, it has superior mechanical properties, especially tensile elongation and tensile strength, compared to a single film of soluble resin, making it easier to handle thin products required for capacitor applications and during processing. Furthermore, the humidity characteristics (especially hygroscopicity), which is said to be the biggest drawback of aromatic polyamides, have been improved, and since it has fusion properties, it has a very large effect when used in capacitors.

Furthermore, since a relatively inexpensive soluble resin is used, the manufacturing cost of the film can be reduced, and the capacitor can be manufactured at low cost.

It is also useful for variable capacitor dielectrics, transformer insulators, insulators for various motors, coil insulators, bases for flexible printed circuit boards, etc.

Furthermore, if the surface properties of the film are within the preferable ranges mentioned above, the surface will not be scratched by rubbing during processing, and there will be little variation in dielectric constant in the case of the same film. Therefore, when used in a capacitor, for example, a capacitor with little variation in capacitance and a low failure rate withstand voltage can be obtained.

Claims (1)

[Claims] (1) Consisting of a blend resin of an aromatic polyamide and a soluble resin, the amount of the aromatic polyamide is 5% of the blend resin.
A heat-resistant capacitor characterized by using a film as a dielectric material in a range of % by weight or more and 90% by weight or less.