JPH03237135A - Heat-resistant film - Google Patents

Abstract

PURPOSE:To obtain the title film having a specific thermal dimensional change ratio, dimensional stability and excellent mechanical characteristics such as Young's modulus and tensile strength, comprising an aromatic polyamide and soluble resin in a specific ratio. CONSTITUTION:(A) A soluble resin (e.g. polycarbonate) is blended with (B) 5-90wt.% aromatic polyamide and (C) a solvent (e.g. N-methyl-2 pyrrolidone) to give the objective film having <=50% thermal dimensional change ratio at 250 deg.C under 0.5kg/mm<2> load at least in one direction and improved temperature characteristics of the aromatic polyamide, especially water vapor absorption.

Description

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

[Prior art] Non-grade films such as polycarbonate, polysulfone, polyetherimide, polyethersulfone, and polysulfide sulfone are used as transparent conductive materials for liquid crystals due to their excellent optical, electrical, and thermal properties. It is being used in a wide range of applications, including films, printer ink ribbons, capacitors, printed circuit boards, and electrical insulation materials. However, a major drawback of these non-quality films, which are relatively inexpensive and have good humidity characteristics, is that they rapidly soften and flow at temperatures above the glass transition point, and are not suitable for the high heat-resistant materials required by the market. remains dissatisfied.

Another major drawback is that the mechanical properties are poorer than that of crystalline films.

On the other hand, films made of aromatic polyamide and aromatic polyimide are known as heat-resistant films, but although they have good heat resistance and mechanical properties, they are expensive due to poor productivity, and have inferior humidity characteristics. It's worse than film.

Molecular conjugation is also being investigated as a method to compensate for the drawbacks of these resins. For example, a high-strength film can be obtained by molecularly compositing polyparaphenylene terephthalamide (aromatic polyamide) with a rigid structure and nylon 6 (J, MACRMOL, 5 CIPHYS, , B1
7 (4), 591-615 (1980)), an example in which a polymer composite was obtained from a rigid reinforcing polymer and a matrix molecule having a flexible skeleton (Japanese Patent Publication No. 1-36
785) has been reported.

There is also a report that by blending aromatic polyamide with low crystallinity with a crystallization accelerator such as non-quality polyether sulfone, the crystallinity of aromatic polyamide is increased and a heat-resistant film is obtained (Proceedings of the Society of Polymer Science and Technology). Collection, 38 (12
), 4149-4154 (1989)').

[Problems to be Solved by the Invention] However, for example, a molecular composite film of polyparaphenylene terephthalamide and nylon 6 can be prepared by dissolving it in concentrated sulfuric acid and adding a large amount of water, since polyparaphenylene terephthalamide is insoluble in organic solvents. It requires a very complicated production method of re-precipitation and heat compression at high temperatures to form a film, making it expensive even if it is industrialized, and the resulting film is only a brittle film with low elongation. Also, Tokuko 1-367
85 lists polyparaphenylenebenzbisthiadol, polyparaphenylene terephthalamide, etc. as rigid reinforcing polymers, but as above, these polymers also need to be dissolved in an acidic solvent to form a film. It is expensive, and the resulting film also has low elongation.

Furthermore, the method of blending a non-quality polymer with an aromatic polyamide with low crystallinity not only takes a long time to crystallize, resulting in poor productivity, but also has poor mechanical properties of the resulting film, making it impractical. .

It is an object of the present invention to solve these problems and provide a heat-resistant film with excellent mechanical properties, chemical properties (mainly moisture absorption properties), and economical efficiency (cost).

[Means for Solving the Problems] The present invention provides a film made of a blend resin of an aromatic polyamide and a soluble resin, wherein the amount of the aromatic polyamide is in the range of 5% to 90% by weight of the blend resin. and the load in at least one direction of the film (0,5
This is a heat-resistant film characterized by a thermal dimensional change rate of 50% or less at 250° C. under kg/mm2).

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

Here, Ar1. Ar2 is composed of one or more structures containing at least one aromatic ring, and may have the same or different compositions, and representative examples thereof include the following.

In addition, some of the hydrogen atoms on the aromatic rings are halogen groups (especially chlorine), nitro groups, C1 to C3 alkyl groups (
In particular, those substituted with substituents such as methyl group) and C1-C3 alkoxy groups are also included. Also, X is -〇-,
-CH2--so2-, -s-, -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, Ar,
, 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, in terms of increasing solubility in solvents and compatibility with soluble resins, structures in which two aromatic rings are bonded via -0--CH2-, -3o2-, -8-CO-, etc. 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, for example, Ar,: (Ar3), (Ar4) b (Ar,,)
.

Ar2': (Ar6) d (Ar7) eHowever, a+d+e≧0.5 b+e≧0. 5 c<0.4 Ar3, Ar6 2 Ar4, Ar: A group Ar in which Ar3 and Ar6 are substituted with a nucleus (such as a halogen).

Aromatic polyamides that satisfy the following conditions are preferred. In addition, Ar1,
Ar3, Ar4, A r 5 , A constituting Ar2
Groups other than r 6 and A r 7 are not particularly limited as long as they satisfy the above formula.

(Here, p and q are integers of 1 to 4, p+q≧1) (Here, Q = an integer of O to 4) A solution of one or more aromatic polyamides and a soluble resin cannot be stored for a long time. The resulting film is also tough 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. Among them, N-methyl-2-pyrrolidone and a mixture of N-methyl-2-pyrrolidone and other amide polar solvents are particularly preferred. In particular, when these solvents are used, polycarbonate, polyvinylidene fluoride, polymethyl methacrylate, polystyrene, polyvinyl alcohol, polyether sulfone,
Polysulfone, polyarylate, polysulfide sulfone, polyetherimide, etc. are preferable, and non-grade resins with remarkable improvement in mechanical properties at high temperatures and excellent humidity properties.
For example, polycarbonate, polyether sulfone, polysulfone, polyarylate, and polysulfide sulfone are more preferred. In particular, CH.

CH.

The resin having both the basic skeleton A and the C=O structure has very good compatibility with the aromatic polyamide, so a blend solution obtained by dissolving the aromatic polyamide and the soluble resin in the above solvent. is more preferable because it has excellent long-term storage stability and provides a film 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. Also,
Further, another resin is added as a third component to the blend resin of the aromatic polyamide and soluble resin, preferably at most 40% by weight, more preferably at most 30% by weight, even more preferably at most 20% by weight of the soluble resin. For example, when polycarbonate is used as the soluble resin, mechanical properties are improved by adding polyethersulfone, polysulfone, etc. 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. may be used within a range that does not prevent the soluble resin and the aromatic polyamide from being compatible, preferably within 20% by weight of the total solvent amount, more preferably within 15% by weight. I don't mind if it is included.

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.

Load of the film of the present invention in at least one direction (0.5k
The thermal dimensional change rate at 250°C under g/anal 2) is 50% or less. If it is larger than 50%, it cannot withstand use in cases where tension is applied at high temperatures, such as in thermal transfer applications. Preferably it is 40% or less, more preferably 20% 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 preferable.
5/°C or less is more preferable. If it exceeds 5×(0-5/°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. In addition, the strength in at least one direction is 5 kg/
1 m112 or more is preferable, more preferably 7 kg/l
lll112 or more, more preferably 9 kg/m
m2 or more. Young's modulus in at least one direction is 15
0 kg/mm2 or more is preferable, more preferably 20 kg/mm2 or more.
It is 0 kg/mm2 or more. Further, the F-5 value (strength at 5% elongation) of the film of the present invention in at least one direction is preferably 4 kg/mm2 or more, and 6 kg/mm2 or more.
am 2 or more is more preferable.

The thickness of the film of the present invention is preferably 0.2 to 200 μm, more preferably 1 to 50 μm. In addition, the density of this film is preferably 1.0 to 1.5 g/cm3, and 1.1
-1.4g/cm3 is more preferable.

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

2 to 7 are preferred. In addition, the dielectric loss tangent (lkHz) is 3
% or less is preferable. More preferably, it is 2% or less.

The light transmittance of the film of the present invention is preferably 50% or more. More preferably, it is 60% or more.

The average surface roughness (Ra) of the film of the present invention is 10 to 5.
00 nm is preferable, more preferably 30 to 300 nm
It is. This range is particularly desirable since workability during processing and runnability during use will be even better. Note that in order to achieve this surface roughness, it is effective to add inorganic or organic fine particles.

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 method for producing a heat-resistant film of the present invention will be described, but the method is not limited thereto.

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. Dioxychloride and diamine are mixed in a low moisture amide polar solvent at low temperature (usually 50°C).
The polymerization is then carried out by stirring at a temperature (preferably below 30°C) for ~2 hours. 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. The blending stock solution includes
In some cases, inorganic salts such as calcium chloride and magnesium chloride are added as solubilizing agents.

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 (η1nh). That is, the intrinsic viscosity is preferably 1.0 to 10.0 when dissolved in N-methyl-2-pyrrolidone.
, 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.

The apparent intrinsic viscosity obtained from the film-forming stock solution thus obtained is preferably O0l to 8.0, more preferably 0.2
~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 10
~20,000 voids is more desirable. Resin concentration is 1-5
0% is desirable, and 5 to 30% is 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. - Desirable considering 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. ■% or less is better.

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 in the wet temperature range, and in order to improve the mechanical properties of the final film, the film is swollen in the wet process by 1° to 5° 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 characteristics of the present invention. In addition, in the heating step, 1.01 to 5. Stretched 0 times. 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, inorganic salts and amide-based polar solvents are rapidly replaced in the aqueous medium, which tends to cause voids or surface roughness in the final film. Inorganic salts such as calcium chloride, lithium chloride, lithium bromide, etc. may be contained in the aqueous medium to control the substitution rate as necessary, or water and amide polar solvents/inorganic salts may be added to the water tank in multiple stages. to create a concentration gradient in a mixture of Similar to the wet-dry method, the film may be stretched 1601 to 5 times in the longitudinal direction in this step. After the first wet process, the film is heated (200 to 500
°C) and transverse stretching (1.01 to 5.0 times). 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 heat-resistant film of the present invention can be obtained in the manner described above.

The thus obtained heat-resistant film of the present invention can be used for thermal transfer ribbons, printed circuit boards, capacitor electrical insulation materials, etc., but in particular, it can be used for thermal transfer ribbons, printed circuit boards,
Desirable for capacitor applications.

[Example] Next, embodiments of the present invention will be described based on Examples.
It is not limited to this. In addition, the method of measuring the characteristics in the examples is as follows.

(2) Intrinsic viscosity (η1nh) 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.

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

■ Elongation at break, strength, Young's modulus, F-5 value TR8 type tensile tester, width 10 mm, length 50 mm.

The measurement was performed at a tensile speed of 300 mm/min.

■ 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 calculation was calculated using the formula below.

X100 (%) Moisture absorption rate (%) The weight of the film was measured after being completely dried 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) To remove the influence, set the film to 150
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)■ Thermal dimensional change rate under load Multiply the load by 0 and 5 kg/mm2 to get the temperature by 25
It was placed in the open at 0° C. for 10 minutes, returned to room temperature, measured, and calculated using the following formula.

■ Dielectric constant, tanδ Conforms to ASTM-D-150-81.

0 Light transmittance Measured in accordance with ASTM D-1003.

(2) Average surface roughness (Ra) Measured using a high-precision thin film step measuring device 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: 0.5μm ・Stylus load: 5mg ・Measurement length: 1mm ・Cutoff value: 0.08mm The definition of Ra can be found, for example, in “Measurement and evaluation method of surface roughness” written by Jibu Nara. ” (Sogo Technological Center 1983).

0 End tear resistance (kg/μm) Measured in accordance with JIS-C-2318, and calculated per 1 μm thickness.

Note that all parts used in the following examples represent parts by weight.

Example 1 75 mo1% of 2-chloroparaphenylenediamine (hereinafter abbreviated as CPA) and 25 mo1% of 4'4'-diaminodiphenyl ether (hereinafter abbreviated as 4,4'DAE) were mixed with 100 mo1% of 2-diamine.

20°C in terephthalic acid chloride (hereinafter abbreviated as CTPC) and N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP)
The reaction was performed as follows 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, and 200 parts of a separately prepared NMP solution containing 30 parts of polycarbonate (PC) was added thereto to obtain a blend solution. The intrinsic viscosity was 1.3 and the solution viscosity was 610 poise.

This film-forming stock solution was uniformly cast onto a glass plate using an applicator, and after drying in an open environment at 120°C for 8 minutes,
Peel it off from the glass plate and immerse it in running water for 10 minutes. After drying the moisture in an open environment at 100℃ under tension,
Heating at 300° C. for minutes yielded a final film with a thickness of 9 μm. The resulting film had a breaking elongation of 25%, a tensile strength of 12 kg/ll, and a Young's modulus of 450 kg/mm2.
, F-5 value 11kg/IItl12, end tear resistance 0.
52 kg/μm, heat shrinkage rate at 250°C for 10 minutes is 0.5%, load at 250°C (0.5) cg/1m12
) The thermal dimensional change below is 15%, and the thermal expansion coefficient (α) is 1.7.
X10-5 parts ℃, moisture absorption rate is 1.0%, average surface roughness is 8
The film was strong with a weight of 0 parts m, and had excellent humidity characteristics, heat resistance, and workability.

Example 2 CPA70mo 1%, 4.4”-diaminodiphenylsulfone (hereinafter abbreviated as DAS) 30mo1% and CTP
C50mo 1%, terephthalic acid chloride (hereinafter referred to as TPC)
A solution prepared by dissolving 35 parts of aromatic polyamide obtained by isolation after reaction with 50 mo1% of polyamide in 300 parts of NMP was blended with 100 parts of an NMP solution containing 15 parts of polycarbonate. This blended solution was cast onto a glass plate, dried at 150°C for 4 minutes, and then heated at 230°C for an additional 30 seconds.
Dry at °C. Use this film with a stretcher 2
After stretching 1.3 times in length and width at 50℃, further stretching at 280℃
heated with. The obtained film had excellent properties as shown in Table 1.

Example 3 When 100 mo1% of CPA was reacted with 1% of CTPCroomo, 70 parts of polycarbonate was polymerized in NMP in which 70 parts of polycarbonate was dissolved in advance based on 30 parts of the resulting aromatic polyamide. The solution thus obtained is uniformly cast onto a glass plate using an applicator, and when immersed in running water, it naturally peels off from the glass plate. Soak for another 10 minutes,
After removing the solvent and once drying the moisture in an oven at 100°C, the film was heated at 300°C for 1 minute to obtain a final film with a thickness of 5 μm. The film had very excellent properties as shown in Table 1.

Example 4 In the same manner as in Example 1, 4.4'-DAEI 00m
30 parts of aromatic polyamide obtained from o1% and CTPCloomo 1% and polyethersulfone (PES) 7
A film consisting of 0 parts was produced.

The film had very excellent properties as shown in Table 1.

Example 5 In the same manner as in Example 2, 3.4'-DAE 100m
A film was produced consisting of 20 parts of aromatic polyamide obtained from 1% o and 100 mo1% of TPC and 80 parts of polycarbonate. Note that the film was stretched 1°6 times both in the length and width. As shown in Table 1, the film had very excellent properties.

Example 6 In the same manner as in Example 1, CPA85mol1%, 4.4
'-DAE 15mo 1% and CTPC 100m.

350 parts of an NMP solution containing 10 parts of aromatic polyamide obtained from a 1% reaction and 40 parts of polycarbonate was prepared. The solution viscosity was 80 poise at 30°C. This blended stock solution was continuously extruded into water through a nozzle with a width of 100 mm and 1 slit of 0.1 mm, and vertically 1.
The film was stretched 0.5 times and dried at 95° C., and then heated at 290° C. while being stretched 1.3 times in the transverse direction to obtain a long film. As shown in Table 1, the film had very excellent properties.

Example 7 A film was prepared in exactly the same manner as in Example 1 except that polyarylate ("U polymer") was used instead of polycarbonate, and the film had excellent properties as shown in Table 1.

Comparative Example 1 A polycarbonate NMP solution was cast onto a glass plate,
The properties of the film made only of polycarbonate obtained by drying at 120°C for 6 minutes and then heating to 210°C were very poor in thermal properties, as shown in Table 1.

Comparative Example 2 A film was prepared in the same manner as in Example 1 except that the amount of aromatic polyamide was changed to 1 part.
At ℃, it melted and no film was obtained. Therefore, a film was obtained by changing the heating temperature to 250°C, but as shown in Table 1, the thermal properties were very poor.

Comparative Example 3 In the same manner as in Example 1, 100 mo1% of 4,4'-diaminodiphenylmethane and TPCloom were added.

A film was produced consisting of 95 parts of aromatic polyamide obtained from a 1% reaction and 5 parts of polycarbonate, but the film had poor humidity characteristics.

As mentioned above, films outside the scope of the present invention have thermal properties,
Either of the humidity characteristics was poor.

Example 8 20 parts of an NMP solution in which 3 parts of polyether sulfone (10% by weight based on polycarbonate) was dissolved was added to the membrane-forming stock solution obtained in the same manner as in Example 1 to prepare a new membrane-forming stock solution, A film with a thickness of 8 μm was obtained in the same manner as in Example 1. The elongation at break of the obtained film was 30%, the tensile strength was 16 kg/Rule 2, and the Young's modulus was 420 kg/lll12.
, end tear resistance is 0°66 kg/μm, 250°C, 1
The heat shrinkage rate for 0 minutes is 0. 4% under load at 250℃ (0
, 5kg/mm2), the thermal dimensional change is 12%, and the moisture absorption rate is 1.
．． 0%1, humidity expansion coefficient (β) is 2.1xlO-'/%
The film had excellent RH, toughness, humidity characteristics, and heat resistance. Further, the dielectric constant ε was 3.5, and the tan δ was 0°7%, indicating excellent electrical properties, and the light transmittance was 75%, indicating excellent optical properties. Furthermore, the average height of protrusions on the surface was 120 nm, and the film had good smoothness.

[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. It also has better mechanical properties, especially Young's modulus and tensile strength, than a single film of soluble resin, and is easy to handle and process, and can be easily formed into a thin film. Furthermore, the humidity properties (especially hygroscopicity), which are said to be the biggest drawback of aromatic polyamides, are improved.

In addition, since the aromatic polyamide of the present invention and the soluble resin have very good compatibility, the blend solution has excellent long-term stability.
In addition, the two types of polymers are easily finely dispersed in the resulting film, and the generation of microvoids at the interface is suppressed, resulting in excellent mechanical properties and transparency.

Furthermore, since a relatively inexpensive soluble resin is used, the manufacturing cost of the film can be reduced.

Claims (1)

[Claims] (1) A film made of a blended resin of an aromatic polyamide and a soluble resin, in which the amount of the aromatic polyamide is in the range of 5% to 90% by weight of the blended resin, and the amount of the aromatic polyamide is in the range of 5% to 90% by weight of the blended resin, and Load (0.5kg
/mm^2) A heat-resistant film having a thermal dimensional change rate of 50% or less at 250°C.