JP2722333B2 - Manufacturing method of roughened polyimide film - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a roughened polyimide film.
It is related to a method for producing LUM. For more details
Akira is especially useful as a base film for high-density recording media.
For the production of roughened polyimide films
is there. [0002] Non-magnetic properties of magnetic recording media such as magnetic tapes
As a support (base film), polyethylene
Film made of polyester such as terephthalate
Has been commonly used, but recently heat resistance and strength
The use of aromatic polyimide film has been suggested.
ing. As a characteristic of the non-magnetic support, heat resistance as described above
The strength and strength are very important, but at the same time
Good magnetic recording
It is a critical requirement to get a medium. Ie magnetic material
With a porous layer formed on the surface of the base film by evaporation
High-density recording is possible with metal thin film type magnetic recording media
However, the magnetic layer thus formed has a very small thickness.
The surface morphology of the base film used
It tends to appear as the surface morphology of the magnetic layer. others
If the surface of the base film is too rough,
There is a problem of worsening, for example, output drop or drop
An increase in buyouts occurs. On the other hand, on the other hand,
For the purpose of improvement, make the film surface
Smoothness significantly reduces slipperiness and tape
There is a problem that runnability and durability deteriorate. [0003] For the above reasons, the running property of the tape and the wear resistance
Moderate irregularities on the tape surface to improve wear and durability
Have been proposed. For example, tape
A method of coating a coating solution containing fine particles on the surface,
Fine particles are added to the base film to
Method of providing fine projections, polymer on base film surface
After coating the solution, stretching the film
A method of forming a discontinuous film has been proposed. [0004] However, the conventional
In the method, fine particles are dispersed, classified, filtered,
Printing process and stretching process to conventional film forming process
Must be integrated, and these processes have strict precision requirements.
Equipment is expensive, and operation management of film production is difficult.
Often it becomes difficult. SUMMARY OF THE INVENTION The present invention provides a roughened poly
In the method for producing a mid film, the step (a) is entirely aromatic.
15 to 85 mol% of the tetracarboxylic acid component
3,3 ', 4,4'-biphenyltetracarboxylic acid or
Is 2,3,3'4'-biphenyltetracarboxylic acid
Biphenyltetracarboxylic acid, its acid dianhydride,
Is the lower ester and 85 to 15 mol% of pyromellit
Acid, its acid dianhydride, or its lower ester.
Aromatic tetracarboxylic acid component and wholly aromatic diamine component
10-95 mol% of paraphenylenediamine per minute
Or metaphenylenediamine and 5-90 mol% of 4,
4'-diaminodiphenyl ether, 3,4'-diamid
Nodiphenyl ether or 3,3'-diaminodiph
Phenyl ether and aromatic diamine component
The polyamic acid solution was cast on a support and heated.
To obtain a self-supporting film
After peeling the film from the support, the maximum heating temperature is
From the glass transition temperature of the resulting aromatic polyimide film
(B) heating
Fine projections with a diameter of 0.02-2 μm on the film surface
Is 10 ⁴ -10 ⁸ Pieces / mm ² It should be noted that the number of
The present invention relates to a method for producing a polyimide film. Hereinafter, the present invention will be described with reference to typical embodiments.
This will be described in detail with reference to FIG. The roughened polyimide of the present invention
Aromatic polyamid used in film production
Citric acid is 15 to 15% of the total aromatic tetracarboxylic acid component.
85 mol% of biphenyltetracarboxylic acids and 85-1
Aromatic tetraca composed of 5 mol% pyromellitic and acids
The rubonic acid component and the total aromatic diamine component are 10 to 10%.
95 mole% (preferably 30 to 95 mole%) phenyle
5 to 90 mol% (preferably 5 to 70 mol%)
%) Diaminodiphenyl ethers
Group diamine component, substantially equimolar, organic polar
It is a polyamic acid obtained by polymerization in a solvent. Bi
As phenyltetracarboxylic acids, biphenyltet
Lacarboxylic acid, its dianhydride, or its lower alkyl
Esters, furthermore their mixtures can be mentioned
You. As biphenyltetracarboxylic acids, 2,
2 ′, 3,4′-biphenyltetracarboxylic acids, 3,
3 ′, 4,4′-biphenyltetracarboxylic acids are preferred
Can be listed. [0007] Pyromellitic acids include
An acid, its dianhydride, or its lower alkyl ester,
Furthermore, mixtures thereof can be mentioned. Above fragrance
The aromatic tetracarboxylic acid component includes a wholly aromatic tetracarboxylic acid.
70 mol% or less, preferably 50 mol% based on the acid component
Or less, more preferably 30 mol% or less.
Aromatic tetracarboxylic acids may be used. Like that
Examples of other aromatic tetracarboxylic acids include 3,3 ',
4,4'-benzophenonetetracarboxylic acid, 2,2-bis (3,4
-Dicarboxyphenyl) propane, bis (3,4-dical)
Boxyphenyl) methane, bis (3,4-dicarboxyphen)
Nil) ether, bis (3,4-dicarboxyphenyl)
Sphines and anhydrides of these carboxylic acids, lower alcohols
And alkyl esters. The phenylenediamines include 1,4-
Diaminobenzene (paraphenylenediamine), 1,3
-Diaminobenzene, 1,2-diaminobenzene, etc.
Can be mentioned. As an aromatic diamine component,
95 mol% or less based on the aromatic diamine component, preferably
Is at most 70 mol%, more preferably at most 50 mol%,
Particularly preferably 30 mol% or less, and 5 mol% or more
The diaminodiphenyl ethers are used together in an amount. So
Examples of diaminodiphenyl ethers such as
4'-diaminodiphenyl ether, 3,4-diamino
Diphenyl ether, 3,3'-diaminodiphenyle
Preferred examples thereof include: Aromatic diamine component
The amount is 70 mol% or less based on the total aromatic diamine component.
Lower, preferably 50 mol% or less, more preferably 30 mol% or less.
Even when other aromatic diamines are used together in an amount of not more than
Good. Such other aromatic diamine components include:
Dip such as 4,4'-diaminodiphenylthioether
Phenylthioether-based diamine, 3,3′-diaminobenzene
Nzophenone, 4,4'-diaminobenzophenone, etc.
Benzophenone diamine, 3,3'-diaminodiph
Phenylphosphine, 4,4'-diaminodiphenylphospho
Diphenylphosphine diamines such as fins, 3,
3'-diaminodiphenylmethane, 4,4'-diamino
Diphenylmethane diamine such as diphenylmethane
And so on. [0009] The polymerization reaction is carried out with each monomer component and / or
Is an oligomer or low molecule generated by both monomer components
Using an organic polar solvent that uniformly dissolves the polyamic acid
Do it. Examples of such organic polar solvents include N, N-
Dimethylformamide, N, N-dimethylacetamide, N-
Such as methyl-2-pyrrolidone and N-methylcaprolactam
Amide solvents, dimethyl sulfoxide, hexamethyl
Osformamide, dimethyl sulfone, tetramethylene
Rufone, dimethyltetramethylene sulfone, pyridine,
Examples include ethylene glycol. these
Benzene, toluene, benzonitrile
, Xylene, solvent naphtha, and dioxane
It can also be used by mixing with such other organic solvents.
Production of polyamic acid by polymerizing each monomer component
A known additive component can be optionally added to the reaction solution. In carrying out the polymerization reaction, an organic polar solvent
Is from 5 to 40% by weight, preferably from 6 to 40% by weight.
35% by weight, particularly preferably 10 to 30% by weight
You. Aromatic tetracarboxylic acid component and aromatic diamine component
The polymerization reaction with, for example, each substantially equimolar
At a reaction temperature of 100 ° C or lower, preferably 80 ° C or lower.
By allowing the reaction to take place for about 0.2-60 hours
carry out. Used for the production of the polyimide film of the present invention
The resulting polyamic acid solution has a rotational viscosity measured at 30 ° C.
Is about 0.1 to 50,000 poise, especially 0.5 to 3000
0 poise, more preferably about 1 to 20,000 poise
Handle this polyamic acid solution
It is preferable from the viewpoint of workability. Therefore, the polymerization reaction
To the extent that the resulting polyamic acid exhibits the viscosity described above.
It is desirable to carry out in. In producing the polyimide film of the present invention,
For example, for example, first, the solution of the above-mentioned aromatic polyamic acid is dissolved.
The liquid is first applied to a suitable support (eg, metal, ceramic,
Plastic rolls or metal belts, or
Roll or bell where metal thin film tape is being supplied
G) and cast on the surface of
Polyamic acid having a uniform thickness of about 20 to 1000 μm
The solution is formed into a film, and then a heat source such as hot air or infrared
Use to heat to 60-160 ° C to gradually remove solvent
By pre-drying until it becomes self-supporting,
The self-supporting film is peeled from the support. Peeled off
The self-supporting film has a heating loss of 10 to 65 layers.
%, Preferably 15 to 60 weights.
It is particularly preferred to be in the range of% by weight. Polyamic acid
When manufacturing a polyimide film from a solution,
Any known additive may be added to the riamic acid solution.
Good. The heating loss of the self-supporting film is measured
Dry the symmetrical film at 420 ° C. for 20 minutes, before drying
Weight W ₁ And weight W after drying _Two From the following equation
Value. Heating loss (% by weight) = ｛(W ₁ -W _Two ) / W ₁ ｝ × 10
Next, the self-supporting film was filled with
Solvent contained in the system and imidization of amide / acid bond
Heat at a temperature of about 100 ° C or higher to perform conversion
Thus, an aromatic polyimide film is manufactured.
Maximum heating when producing this aromatic polyimide film
The temperature is lower than the glass transition temperature (Tg) of the aromatic polyimide.
Above, preferably at least 20 ° C. above Tg, more preferably
Is between 30 and 200 ° C., particularly preferably between 50 and 160 ° C.
The aromatic polyimide film formed by the temperature
Forming fine protrusions that meet the desired conditions on the lum surface
Can be. Aromatic polyamide obtained under the above heating conditions
Most of the size of the fine protrusions formed on the film surface
The minutes are in the range of 0.02 to 2 μm. The micro bump here
What is the size of the film?
Length of the largest diameter part of the fine protrusion observed when enlarged
Say The aromatic polyimide film obtained by the production method of the present invention
The diameter formed on the film surface is 0.02 to 2 μm
Of micro projections is 10 ^Four -10 ⁸ Pieces / mm ^Two And preferred
Or 10 ^Five -10 ⁸ Pieces / mm ^Two In the range of
Preferably 10 ⁶ -10 ⁸ Pieces / mm ^Two In the range. this
The number of fine protrusions is 10,000 times with the electron microscope on the film surface.
The maximum diameter of the protrusion observed when enlarged is 0.02μ or more
This is a numerical value obtained by counting the number of items. Formed on the surface of the aromatic polyimide film
The size and number of microprojections
Lum composition, glass transition temperature and maximum heating temperature
Become Glass transition temperature and maximum heating as general trends
The greater the temperature difference, the more
The size of the microprojections increases within the above range, and
The number increases. Furthermore, as an aromatic diamine component
When 4,4'-diaminodiphenyl ether component is used
On the film surface
The size and number of fine protrusions formed on the surface tend to increase
is there. In addition, the polyamic acid film is
The maximum heating temperature when converting to
Also, fine protrusions on the surface are formed due to the difference in heating rate
The appearance may be different. Also, generally speaking,
As the lum thickness decreases, the size and number of microprojections decrease.
Tend to The roughened polyimide film obtained by the present invention
The thickness of the lum is usually in the range of 1 to 100 μm,
More preferably, it is in the range of 2 to 50 μm. EFFECT OF THE INVENTION The roughened aromatic polyamide obtained by the present invention
Film, as the aromatic carboxylic acid component,
Specific amounts of biphenyltetracarboxylic acids and pyromellitus
It is obtained in combination with acids and has such an aromatic
Group polyimide film has excellent mechanical properties such as high
High tensile strength (usually about 20kg / mm ^Two 25 kg
/ Mm ^Two Above), moderate elastic modulus (usually about
300-900kg / mm ^Two ) And also has excellent thermal
Properties, such as a high second order transition temperature (usually below about 300 ° C)
Above), has a high pyrolysis temperature (usually above 400 ° C)
Therefore, especially with magnetic recording media support such as magnetic tape
And show excellent characteristics. In addition, the surface roughening obtained by the present invention
The polyimide film has a moderate amount of fine protrusions on its surface.
When a magnetic recording layer is formed thereon,
Indicates that the surface of the recording layer has approximately the same
Will have. Therefore, the base layer for the magnetic recording medium
LUM, especially as a base film for metal thin-film magnetic recording media.
, The electromagnetic conversion characteristics of the resulting magnetic recording medium
And the runnability and durability are also excellent. EXAMPLES Physical property values in the following Examples and Comparative Examples
The method for evaluating the characteristics is as follows. (1) Glass transition temperature: tension with Rigaku Denki's TMA device
It was determined by the method. (2) Number of fine protrusions: 10,000 times magnification of the film surface with an electron microscope
Observe in Step 3 and use the ones with the maximum diameter of the projections of 0.02 μm or more.
And counted the number. (3) Electromagnetic conversion characteristics: recorded at a center frequency of 4.5 MHz,
The S / N ratio (relative value) at the time of reproduction is based on Comparative Example 14.
(0 dB). A: The output is larger than -3 dB. B: The output is smaller than -3 dB. (4) Runnability: display of the screen caused by disturbance of tape running
Observed. A: The running screen is smooth and there is nobody on the playback screen. B: Running performance is poor and the playback screen is seen. (5) Durability: scratches on the magnetic surface after running 100 times
And the output decreased. A: Little or no scratches. Output drop is -3
less than dB. B: Strong scratches are observed. Output decrease from -3dB
large. [Example 1] Cylindrical weight having an internal volume of 1 liter
448 g of N, N-dimethylacetamide, p-fe
Nilendiamine (PPD) 22.709 g (0.21 m
), And 4,4'-diaminodiphenyl ether (4,4 '
-DADE) 18.022 g (0.09 mol)
Stirred at room temperature (about 30 ° C.) in nitrogen. Add 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride (s-BPD
A) 44.133 g (0.15 mol) and pyromeric
32.718 g (0.15 mol) of tonic dianhydride (PMDA)
) And stirred for 6 hours to remove the polyamic acid solution.
Obtained. The logarithmic viscosity of this solution (30 ° C., 0.5 g / 100
mL, N, N-dimethylacetamide) is 2.54;
The rotational viscosity was 2,400 poise (30 ° C.). The viscosity is
It was measured using an E viscometer manufactured by Tokyo Keiki Co., Ltd. Poly above
An amic acid solution is cast on a glass plate to form a polyamic acid.
A solution film is formed, and the film is heated with hot air at 120 ° C. for 20 minutes.
After drying for a minute, the solvent is distilled off.
Was manufactured. Next, a polyamic acid film is
I peeled it off. The loss on heating of this film is 34.1 weight
%Met. Apply this polyamic acid film to a metal frame
From 200 ° C to 400 ° C in a hot air dryer.
The temperature was raised in 0 minutes to obtain an aromatic polyimide film having a thickness of 35 μm.
Created a film. This aromatic polyimide film
The lath transition temperature is 360 ° C.
The number of microprojections on the surface of the mid film is 5.0 × 10 ⁶ Pieces / m
m ^Two Met. Example 2 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 360 ° C) and 2
Except that the temperature was raised from 00 ° C to 450 ° C in 25 minutes.
35 μm thick aromatic polyimide in the same manner as in Example 1.
A film was produced. This aromatic polyimide film table
The number of fine protrusions on the surface is 2.6 × 10 ⁷ Pieces / mm ^Two Met. Example 3 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 360 ° C) and 2
After raising the temperature from 00 ° C to 450 ° C in 25 minutes, 45
Same as Example 1 except that heating was performed at 0 ° C. for 5 minutes
To produce an aromatic polyimide film having a thickness of 21 μm.
Built. Fine protrusions on the surface of this aromatic polyimide film
The number is 2.3 × 10 ⁷ Pieces / mm ^Two Met. Example 4 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 360 ° C) and 2
After raising the temperature from 00 ° C to 450 ° C in 25 minutes, 45
Same as Example 1 except that heating was performed at 0 ° C. for 5 minutes
To produce an aromatic polyimide film having a thickness of 10 μm.
Built. Fine protrusions on the surface of this aromatic polyimide film
The number is 1.0 × 10 ⁷ Pieces / mm ^Two Met. Example 5 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 360 ° C) and 2
After raising the temperature from 00 ° C to 450 ° C in 20 minutes, 45
Same as Example 1 except that heating was performed at 0 ° C. for 5 minutes
To produce an aromatic polyimide film having a thickness of 56 μm.
Built. Fine protrusions on the surface of this aromatic polyimide film
The number is 1.8 × 10 ⁷ Pieces / mm ^Two Met. Example 6 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 360 ° C) and 2
After raising the temperature from 00 ° C to 450 ° C in 20 minutes, 45
Same as Example 1 except that heating was performed at 0 ° C. for 5 minutes
To produce an aromatic polyimide film having a thickness of 12 μm.
Built. Fine protrusions on the surface of this aromatic polyimide film
The number is 5.0 × 10 ⁶ Pieces / mm ^Two Met. Comparative Example 1 Maximum Heating Temperature of Polyamic Acid
Temperature of 300 ° C (Tg of polyimide = 360 ° C)
Except that the temperature was raised from 00 ° C to 300 ° C in 10 minutes.
35 μm thick aromatic polyimide in the same manner as in Example 1.
A film was produced. This aromatic polyimide film table
No fine protrusions were formed on the surface. Comparative Example 2 Maximum Heating Temperature of Polyamic Acid
Temperature is 350 ° C (Tg of polyimide = 360 ° C) and 2
Except that the temperature was raised from 00 ° C to 350 ° C in 15 minutes.
35 μm thick aromatic polyimide in the same manner as in Example 1.
A film was produced. This aromatic polyimide film table
No fine protrusions were formed on the surface. [Evaluation as Magnetic Tape Support]
On the polyimide film surface obtained by vacuum evaporation
A 0.2 μm thick Co-Cr alloy layer is formed to form a magnetic tape.
The electromagnetic conversion characteristics, runnability and durability of the magnetic tape
The property was evaluated by the method described above. The results are shown in Table 1.
You. Table 1 ──────────────────────────────────── Number of fine protrusions (× 10 ⁶ ) Electromagnetic conversion characteristics Runnability Durability Example 1 5 A A A Example 2 26 A A A Example 3 23 A A A Example 4 10 A A A Example 5 18 A A A Example 6 5 A A A} {Comparative Example 10 0 ABB Comparative Example 2 0 ABB} Example 7 p-phenylenediamine (P
PD) was used in an amount of 0.15 mol, and 4,4′-diamino
The amount of diphenyl ether (4,4'-DADE) used was reduced to 0.
Polyamide was prepared in the same manner as in Example 1 except that the amount was changed to 15 mol.
Obtained acid. The logarithmic viscosity of this solution (30 ° C., 0.5
g / 100 mL, N, N-dimethylacetamide) is 2.6
1 and a rotational viscosity of 4300 poise (30 ° C.).
Was. Cast the above polyamic acid solution onto a glass plate
A film of a polyamic acid solution is formed, and the film is
The solvent was distilled off by drying with hot air of
A carboxylic acid film was formed. Next, the polyamic acid
Lum was peeled from the glass plate. Heat loss of this film
Was 37.6% by weight. This polyamic acid fill
Attach it to a metal frame, and in a hot air dryer,
Raise the temperature to 400 ° C for 20 minutes, and aroma of 39μm thickness
A group III polyimide film was produced. In addition, this aromatic po
The glass transition temperature of the polyimide film was 330 ° C.
Was. The number of fine protrusions on the surface of this aromatic polyimide film is
2.8 × 10 ⁷ Pieces / mm ^Two Met. Example 8 Maximum heating temperature of polyamic acid
Temperature is 410 ° C (Tg of polyimide = 330 ° C) and 2
Except that the temperature was raised from 00 ° C to 410 ° C in 20 minutes.
Aromatic polyimide having a thickness of 39 μm in the same manner as in Example 7.
A film was produced. This aromatic polyimide film table
2.5 × 10 ⁷ Pieces / mm ^Two Met. Example 9 Maximum heating temperature of polyamic acid
Temperature is 450 ° C (Tg of polyimide = 330 ° C) and 2
Except that the temperature was raised from 00 ° C to 450 ° C in 25 minutes.
Aromatic polyimide having a thickness of 39 μm in the same manner as in Example 7.
A film was produced. This aromatic polyimide film table
The number of fine projections on the surface is 4.1 × 10 ⁷ Pieces / mm ^Two Met. Comparative Example 3 Maximum Heating Temperature of Polyamic Acid
The temperature is 300 ° C (Tg of polyimide = 330 ° C) and 2
Except that the temperature was raised from 00 ° C to 300 ° C in 10 minutes.
Aromatic polyimide having a thickness of 39 μm in the same manner as in Example 7.
A film was produced. This aromatic polyimide film table
No fine protrusions were formed on the surface. Comparative Example 4 Maximum Heating Temperature of Polyamic Acid
Temperature is 340 ° C (Tg of polyimide = 350 ° C) and 2
Except that the temperature was raised from 00 ° C to 350 ° C in 15 minutes.
Aromatic polyimide having a thickness of 39 μm in the same manner as in Example 7.
A film was produced. This aromatic polyimide film table
No fine protrusions were formed on the surface. [Evaluation as a magnetic tape support]
On the polyimide film surface obtained by vacuum evaporation
A 0.2 μm thick Co-Cr alloy layer is formed to form a magnetic tape.
The electromagnetic conversion characteristics, runnability and durability of the magnetic tape
The property was evaluated by the method described above. The results are shown in Table 2.
You. Table 2 数 Number of fine protrusions (× 10 ⁶ ) Electromagnetic conversion characteristics Runnability Durability Example 7 26 A A A Example 8 25 A A A Example 9 41 A A A ─────────────────────────────────── {Comparative Example 30 ABB} Comparative Example 40 0ABB [Example 10] p-phenylenediamine
The amount of (PPD) used was 0.12 mole and 4,4'-diamine
The amount of nodiphenyl ether (4,4'-DADE)
0.15 mol, 3,3 ', 4,4'-biphenyltetracar
The amount of boric acid dianhydride (s-BPDA)
Use of pyromellitic dianhydride (PMDA)
Same as Example 1 except that the amount was changed to 0.18 mol
Thus, a polyamic acid was obtained. The logarithmic viscosity of this solution (30
° C, 0.5g / 100mL, N, N-dimethylacetamide
Is 2.01 and the rotational viscosity is 1500 poise (3
0 ° C). Apply the above polyamic acid solution to a glass plate
Cast on top to form a film of polyamic acid solution,
The film is dried with hot air at 120 ° C for 20 minutes to distill off the solvent.
Thus, a polyamic acid film was formed. Next, Polya
The mix acid film was peeled from the glass plate. This fill
The heat loss of the system was 36.2% by weight. This polyamide
Attach the acid film to a metal frame and place it in a hot air dryer.
The temperature was raised from 200 ° C to 400 ° C in 20 minutes,
A 3 μm aromatic polyimide film was produced. In addition,
The glass transition temperature of this aromatic polyimide film is 35
It was 0 ° C. The fineness of the surface of this aromatic polyimide film
The number of fine projections is 9.0 × 10 ⁶ Pieces / mm ^Two Met. Example 11 Maximum heating of polyamic acid
The temperature is 410 ° C. (Tg of polyimide = 350 ° C.)
Except that the temperature was raised from 200 ° C to 410 ° C in 20 minutes
In the same manner as in Example 10, a 43 μm-thick aromatic polymer was used.
A mid film was produced. This aromatic polyimide fill
3.4 × 10 ⁷ Pieces / mm ^Two So
Was. Example 12 Maximum heating of polyamic acid
The temperature is 450 ° C. (Tg of polyimide = 350 ° C.)
Except that the temperature was raised from 200 ° C to 450 ° C in 25 minutes
In the same manner as in Example 10, a 43 μm-thick aromatic polymer was used.
A mid film was produced. This aromatic polyimide fill
2.3 × 10 ⁷ Pieces / mm ^Two So
Was. Comparative Example 5 Maximum Heating Temperature of Polyamic Acid
The temperature is 300 ° C (Tg of polyimide = 350 ° C) and 2
Except that the temperature was raised from 00 ° C to 300 ° C in 10 minutes.
In the same manner as in Example 10, an aromatic polyimide having a thickness of 43 μm was used.
A film was manufactured. This aromatic polyimide film
No fine projections were formed on the surface. Comparative Example 6 Maximum Heating Temperature of Polyamic Acid
Temperature is 340 ° C (Tg of polyimide = 350 ° C) and 2
Except that the temperature was raised from 00 ° C to 350 ° C in 15 minutes.
In the same manner as in Example 10, an aromatic polyimide having a thickness of 43 μm was used.
A film was manufactured. This aromatic polyimide film
No fine projections were formed on the surface. [Evaluation as Magnetic Tape Support]
On the polyimide film surface obtained by vacuum evaporation
A 0.2 μm thick Co-Cr alloy layer is formed to form a magnetic tape.
The electromagnetic conversion characteristics, runnability and durability of the magnetic tape
The property was evaluated by the method described above. The results are shown in Table 3.
You. Table 3 ──────────────────────────────────── Number of fine protrusions (× 10 ⁶ ) Electromagnetic conversion characteristics Running property Durability Example 10 9 A A A Example 11 34 A AA Example 12 23 A A A ─────────────────────────────────── ─ Comparative Example 5 0 ABB Comparative Example 6 0 ABB Example 13 p-phenylenediamine
The amount of (PPD) used was 0.12 mole and 4,4'-diamine
The amount of nodiphenyl ether (4,4'-DADE)
0.13 mol, 3,3 ', 4,4'-biphenyltetracar
The amount of boric acid dianhydride (s-BPDA)
Use of pyromellitic dianhydride (PMDA)
Same as Example 1 except that the amount was changed to 0.21 mol
Thus, a polyamic acid was obtained. The logarithmic viscosity of this solution (30
° C, 0.5g / 100mL, N, N-dimethylacetamide
Is 1.90 and the rotational viscosity is 1200 poise (3
0 ° C). Apply the above polyamic acid solution to a glass plate
Cast on top to form a film of polyamic acid solution,
The film is dried with hot air at 120 ° C for 20 minutes to distill off the solvent.
Thus, a polyamic acid film was formed. Next, Polya
The mix acid film was peeled from the glass plate. This fill
The heating loss of the system was 34.7% by weight. This polyamide
Attach the acid film to a metal frame and place it in a hot air dryer.
The temperature was raised from 200 ° C to 400 ° C in 20 minutes to a thickness of 3
A 7 μm aromatic polyimide film was produced. In addition,
The glass transition temperature of this aromatic polyimide film is 35
It was 0 ° C. The fineness of the surface of this aromatic polyimide film
The number of fine projections is 1.2 × 10 ⁷ Pieces / mm ^Two Met. Example 14 Maximum heating of polyamic acid
The temperature is 410 ° C. (Tg of polyimide = 350 ° C.)
Except that the temperature was raised from 200 ° C to 410 ° C in 20 minutes
In the same manner as in Example 10, 37 μm-thick aromatic polyamide
A mid film was produced. This aromatic polyimide fill
4.2 × 10 ⁷ Pieces / mm ^Two So
Was. Example 15 Maximum Heating of Polyamic Acid
The temperature is 450 ° C. (Tg of polyimide = 350 ° C.)
Except that the temperature was raised from 200 ° C to 450 ° C in 25 minutes
In the same manner as in Example 10, 37 μm-thick aromatic polyamide
A mid film was produced. This aromatic polyimide fill
3.6 × 10 ⁷ Pieces / mm ^Two So
Was. Comparative Example 7 Maximum Heating Temperature of Polyamic Acid
The temperature is 300 ° C (Tg of polyimide = 350 ° C) and 2
Except that the temperature was raised from 00 ° C to 300 ° C in 10 minutes.
In the same manner as in Example 13, an aromatic polyimide having a thickness of 37 μm was used.
A film was manufactured. This aromatic polyimide film
No fine projections were formed on the surface. Comparative Example 8 Maximum Heating Temperature of Polyamic Acid
Temperature is 340 ° C (Tg of polyimide = 350 ° C) and 2
Except that the temperature was raised from 00 ° C to 350 ° C in 15 minutes.
In the same manner as in Example 13, an aromatic polyimide having a thickness of 43 μm was used.
A film was manufactured. This aromatic polyimide film
No fine projections were formed on the surface. [Evaluation as Magnetic Tape Support]
On the polyimide film surface obtained by vacuum evaporation
A 0.2 μm thick Co-Cr alloy layer is formed to form a magnetic tape.
The electromagnetic conversion characteristics, runnability and durability of the magnetic tape
The property was evaluated by the method described above. The results are shown in Table 4.
You. Table 4 数 Number of fine protrusions (× 10 ⁶ ) Electromagnetic conversion characteristics Runnability Durability Example 13 12 A A A Example 14 42 A A A Example 15 36 A A A ─────────────────────────────────── {Comparative Example 7 0 ABBB Comparative Example 8 0 ABB} [Examples 16 to 28] p-Phenylene diurea
Min (PPD), 4,4'-diaminodiphenyl ether
(4,4'-DADE), 3,3 ', 4,4'-biphenyltetracar
Boronic dianhydride (s-BPDA) and pyromellit
Table 5 shows the amount of acid dianhydride (PMDA) used.
Except that the amount used was
Mix acid was obtained. The obtained polyamic acid solution is glass
It is cast on a plate to form a film of a polyamic acid solution,
Is dried with hot air at 120 ° C for 20 minutes to evaporate the solvent.
After forming a polyamic acid film,
I peeled the film. This polyamic acid film is
5th notation from 200 ° C in a hot air dryer attached to the frame
20 minutes to the maximum temperature listed (maximum temperature is 400 ° C and
410 ° C) or 25 minutes (maximum temperature 45
(In the case of 0 ° C.) to have the thickness shown in Table 5.
An aromatic polyimide film was manufactured. The aromatic obtained
Table 5 shows the number of fine protrusions on the surface of the polyimide film. Table 5 Example carboxylic acid diamine Maximum heating Polyimide film Number of fine protrusions BPDA / PMDA PPD / DADE Temperature ℃ Tg ℃ Thickness μm × 10 ⁶ ──────────────────────────────────── 16 0.06 / 0.24 0.12 / 0.18 410 345 39 10 17 0.06 / 0.24 0.12 / 0.18 450 345 39 12 18 0.15 / 0.15 0.09 / 0.21 400 302 26 15 19 0.15 / 0.15 0.18 / 0.12 410 347 34 4 20 0.15 / 0.15 0.18 / 0.12 450 347 34 9 21 0.09 / 0.21 0.09 / 0.21 410 342 48 31 22 0.09 / 0.21 0.09 / 0.21 450 342 48 28 23 23 0.18 / 0.12 0.15 / 0.15 400 314 27 6 24 0.12 / 0.18 0.15 / 0.15 400 357 30 5 25 0.12 / 0.18 0.09 / 0.21 450 335 25 44 26 0.09 / 0.21 0.06 / 0.24 450 335 36 27 27 0.06 / 0.24 0.06 / 0.24 450 357 28 24 28 0.06 / 0.24 0.03 / 0.27 450 328 24 19 ───────────────────── ─────────────── 0049] Note: In Table 5, BPDA is s-BPD
A, and DADE represents 4,4′-DADE.
You. Polyimide film surface obtained in Examples 16 to 28
Then, a Co-Cr alloy layer having a thickness of 0.2 μm by vacuum evaporation
Is formed into a magnetic tape.
Performance, runnability and durability were evaluated by the above method
At this time, the evaluation of A was obtained for each item.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location G11B 5/704 G11B 5/704 // B29K 79:00 B29L 7:00 (56) References JP JP-A-60-15437 (JP, A) JP-A-61-111359 (JP, A) JP-A-62-62423 (JP, A)

Claims (1)

(57) [Claims] In the method for producing a roughened polyimide film,
(A) The step is based on the total aromatic tetracarboxylic acid component,
15-85 mol% of 3,3 ', 4,4'-biphenyltetracarboxylic acid or biphenyltetracarboxylic acid which is 2,3,3'4'-biphenyltetracarboxylic acid, its acid dianhydride, or its lower An aromatic tetracarboxylic acid component comprising an ester and 85 to 15 mol% of pyromellitic acid, an acid dianhydride thereof, or a lower ester thereof;
10 to 95 mol% of paraphenylenediamine or metaphenylenediamine with respect to the total aromatic diamine component and 5
A polyamic acid solution obtained from an aromatic diamine component consisting of .about.90 mol% of 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether or 3,3'-diaminodiphenyl ether is flowed on a support. Rolling, heating to obtain a self-supporting film, and after peeling the self-supporting film from the support, heating under the condition that the maximum heating temperature is higher than the glass transition temperature of the obtained aromatic polyimide film. And (b) a diameter of 0.0 present on the film surface.
A method for producing a polyimide film, wherein the number of 2-2 μm fine projections is in the range of 10 ^{4 to} 10 ⁸ / mm ² . 2. Phenylenediamine against wholly aromatic diamine components
And the amount of diaminodiphene
The method for producing a roughened polyimide film according to claim 1, wherein the amount of the nyl ether used is 5 to 70 mol% . 3. The method for producing a roughened polyimide film according to claim 1, wherein the maximum heating temperature is higher than the glass transition temperature of the obtained aromatic polyimide film in the range of 30 to 200C.