JPH11236447A - Polyimide evaporated polymerized film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film having improved flexibility, suppressing generation of cracking peeling, etc., when exposed to an external force such as mechanical processing, and having an excellent electrical insulating property. SOLUTION: This polymerized film is obtained by subjecting (A) at least an acid anhydride of formulae I to III (X is nothing, CO, SO2 , O, etc.) and (B) at least a diamine of formula IV, formula V (R1 to R4 are each CH3 , C2 H5 or C3 H7 ) and formula VI (Y is O, CO, SO2 , etc.), to an evaporated polymerization. Preferably, 3,3',4,4'-bisphenyltetracarboxylic acid anhydride is used as an acid anhydride and 2,2-bis[4-(4-aminophenoxy)pheny]propane is used as a diamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide vapor-deposited polymer film formed by vapor-deposition polymerization of an acid anhydride and a diamine.

[0002]

2. Description of the Related Art Conventionally, a polyimide vapor deposition polymer film formed by vapor deposition polymerization of an acid anhydride and a diamine is PMDA.
Some were obtained by vapor deposition polymerization of (pyromellitic anhydride) / ODA (4,4'-diaminodiphenyl ether). By forming such a polyimide vapor-deposited polymer film on a base material, the base material is provided with electrical insulation, and is used particularly for insulating coating of an electromagnetic material such as an iron core of a relay. Was.

[0003]

However, the above-mentioned polyimide vapor-deposited polymer film has the property of being hard and brittle. After forming the vapor-deposited polymer film on a substrate, the substrate is subjected to mechanical processing or the like to apply an external force. Thus, there is a problem that cracks occur in the vapor-deposited polymer film or a peeling-off phenomenon of the vapor-deposited polymer film occurs, and characteristics such as electric insulation of the base material are deteriorated.

[0004] The present invention has been made in view of the above points, and has an improved electrical insulation property in which the occurrence of cracks and peeling when an external force such as machining is applied is suppressed. It is an object of the present invention to provide a polyimide vapor-deposited polymer film having a high value.

[0005]

The polyimide vapor-deposited polymer film according to claim 1 of the present invention comprises at least one of the acid anhydrides represented by the chemical formulas (A) to (C) and the chemical formula (D) Or (F) by vapor deposition polymerization with at least one of the diamines shown in (F).

[0006] In addition to the constitution of claim 1, the polyimide vapor-deposited polymer film according to claim 2 of the present invention further comprises, as an acid anhydride, 3,3 ', 4,4'- represented by the above chemical formula (G). It is formed by using bisphenyltetracarboxylic anhydride and using 2,2-bis [4- (4-aminophenoxy) phenyl] propane represented by the chemical formula (H) as a diamine. It is.

[0007]

Embodiments of the present invention will be described below. The acid anhydride used in the present invention has the following chemical formula (A)
To (C), at least one of which is used.

[0008]

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[0009]

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[0010]

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The diamine used in the present invention is represented by the following chemical formulas (D) to (F), and at least one of them is used.

[0012]

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[0013]

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[0014]

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As the combination of such an acid anhydride and diamine, for example, a compound represented by the following chemical formula (G):
3 ′, 4,4′-bisphenyltetracarboxylic anhydride (PMDA) and 2,2- represented by the following chemical formula (H)
Combination with bis [4- (4-aminophenoxy) phenyl] propane (BAPB) can be mentioned.

[0016]

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When the polyimide vapor-deposited polymer film of the present invention is formed on a substrate, for example, a vapor-deposition polymerization apparatus as shown in FIG. 1 can be used. In this vapor deposition polymerization apparatus, a vapor deposition tank heater 2 is provided around a vapor deposition tank 1 so as to surround the vapor deposition tank 1, and a vapor deposition space 3 formed in the vapor deposition tank 1.
Can be heated. A vacuum pump 7 is connected to the vapor deposition tank 1 so that the pressure inside the vapor deposition space 3 can be reduced by the vacuum pump 7.

The vapor deposition tank 1 is provided with two conductance portions 11a and 11b inserted from outside the vapor deposition tank 1 into the vapor deposition space 3. The conductance portions 11a and 11b are formed in a cylindrical shape with a bottom, and the bottom is disposed in the vapor deposition space 3 and the opening is disposed outside the vapor deposition tank 1. A plurality of passage holes 10a and 10b are formed in portions of the conductance portions 11a and 11b disposed in the vapor deposition space 3. Raw material evaporating tubes 8a and 8b are connected to the openings of the conductance portions 11a and 11b outside the vapor deposition tank 1, respectively, and the raw material evaporating tube heaters 9a and 9b are provided around the raw material evaporating tubes 8a and 8b. The tubes 8a and 8b are provided so as to surround them so that the raw material evaporating tubes 8a and 8b can be heated.

In the vapor deposition space 3, there is disposed a rotary barrel 4 having an outer surface formed in a net shape and having a cylindrical shape with both ends closed. The rotary barrel 4 is connected to a rotary shaft 5 inserted from outside the vapor deposition tank 1 into the vapor deposition space 3. A motor 6 is connected to an end of the rotary shaft 5 outside the vapor deposition tank 1 to connect the rotary shaft 5. The rotary barrel 4 can be rotated by rotating the shaft by a motor 6.

A method of forming a polyimide vapor-deposited polymer film on the substrate U using such a vapor-deposition polymerization device will be described. First, an acid anhydride S composed of at least one of the acid anhydrides shown in the above (A) to (C) is previously charged into one raw material evaporating tube 8a, and the above-mentioned ( A diamine T composed of at least one of the diamines shown in D) to (F) is charged, and a substrate U is charged in the rotary barrel 4. Then, the vacuum pump 7 is operated to reduce the pressure in the vapor deposition space 3 to a pressure suitable for the vapor deposition polymerization reaction. Here, the pressure in the vapor deposition space 3 is set to 1 × 10 ^{−1 to} 5 × 10 ⁻⁵ Torr, and the vapor deposition polymerization reaction is preferably allowed to proceed under this pressure condition, and more preferably 1 × 10 ⁻² to 1 ×. 10 ⁻³ Torr. Further, the motor 6 is operated to rotate the rotary barrel 4, and the substrate U in the vapor deposition space 3 is heated by the vapor deposition tank heater 2 to a reaction temperature suitable for the vapor deposition polymerization reaction.
Here, it is preferable that the base material U is heated to 180 to 250 ° C., and the vapor deposition polymerization reaction proceeds under this temperature condition.

Next, the raw material evaporating tubes 8a and 8b are heated by the raw material evaporating tube heaters 9a and 9b, respectively.
The anhydride S and the diamine T in 8b are evaporated. At this time, in order to evaporate the acid anhydride S, 18
It is preferable to heat to 0 to 300 ° C, more preferably to 220 to 260 ° C. In order to evaporate diamine T, diamine T is heated to 180 to 280 ° C.
C., preferably 20 ° C.
0 to 240 ° C. The acid anhydride S and the diamine T thus evaporated are introduced into the vapor deposition tank 1 through the respective conductance portions 11a and 11b, and are guided into the vapor deposition space 3 through the through holes 10a and 10b of the conductance portions 11a and 11b. To the base material U. The acid anhydride S and the diamine T that have reached the substrate U form a polyimide vapor-deposited polymer film on the substrate U by a vapor deposition polymerization reaction.

Here, a polyimide vapor-deposited polymer film is formed by a vapor deposition polymerization reaction, as shown in the following reaction formula (I), where an acid anhydride and a diamine react to form a polyamic acid film, and then a polyamic acid film is formed. Is carried out as the dehydration ring closure reaction proceeds.

[0023]

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Here, the portions represented by R ₅ and R ₆ in the formula are arbitrarily selected so as to correspond to the acid anhydrides and diamines represented by formulas (A) to (F), and n is It is a natural number. The polyimide vapor-deposited polymer film of the present invention thus formed can be formed to have a uniform thickness, and has high flexibility, and can be machined or the like on a substrate on which the polyimide vapor-deposited polymer film is formed. When applied to a base material used for an electromagnetic material, it is possible to improve the electrical insulation property and the surface protection property of the base material when the external force is applied to apply an external force.

[0025]

The present invention will be described below in detail with reference to examples. (Examples 1 to 9) As a base material, a magnetic soft iron was subjected to press working, and as shown in FIG. 2, at both ends of a base 13 having a width d ₁ = 13 mm, a depth d ₄ = 3 mm, and a thickness d ₅ = 1 mm,
Pieces 14, 14 having a height d ₆ = 3 mm and a thickness d ₃ = 1 mm
Is set up, and the dimension between the pieces 14, 14 is d ₂ = 11 mm
An iron core 12 having the following shape was formed, and its surface was subjected to copper plating and nickel plating.

For each of the examples, Table 1
A polyimide vapor-deposited polymer film was formed using the acid anhydride and diamine shown in (1). When forming a polyimide vapor-deposited polymer film, an acid anhydride and a diamine were used in an amount of 20 g each, the acid anhydride was evaporated at 280 ° C., and the diamine was evaporated at 260 ° C., and introduced into a vapor deposition tank. , Reaction pressure 2 × 1
A polyimide vapor-deposited polymer film having a film thickness shown in Table 1 was formed on the iron core 12 under the conditions of 0 ^-2 Torr.

Here, the acid anhydrides (G), (B), and
(C) is the above chemical formula (G), (B), (C)
Wherein the diamine (H) is a diamine represented by the above formula (H), a diamine (J), or (K)
Is a diamine represented by the following chemical formulas (J) and (K), respectively.

[0028]

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[0029]

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Comparative Example 1 An acid anhydride represented by the above formula (G) was used as an acid anhydride, and ODA (4,4'-diaminodiphenyl ether) was used as a diamine.
A polyimide vapor-deposited polymer film having a film thickness of 10 μm was formed on the iron core 12 in the same manner as in Example 1 except for using. (Evaluation of Initial Withstand Voltage) After winding a urethane-coated lead wire having a diameter of 0.042 mm around the iron core 12 on which the polyimide vapor-deposited polymer film of each example and comparative example was formed 20 times, coating the end of the lead wire. Was peeled off, and a part of the polyimide vapor-deposited polymer film of the iron core 12 was peeled off to expose the metal surface. Thirty such samples were prepared for each Example and Comparative Example, and probes were applied to the exposed metal surface of the iron core 12 and the exposed metal surface of the lead wire, respectively, and a dielectric breakdown tester (manufactured by Kikusui Electronics, product number "TOS8650") )), A voltage was applied in a slow-up manner, and when the leak current was 10 mA, it was evaluated that dielectric breakdown had occurred. (Evaluation of withstand voltage after machining) The iron core 12 on which the polyimide vapor-deposited polymer film formed in each Example and Comparative Example was formed was fixed at both ends to a fixing jig 16 as shown in FIG. A molding die 15 is attached near the end of the base 13 of the iron core 12, and an LCP resin is injected into the molding die 15 and hardened to form a resin near the end of the base 12 as shown in FIG. LCP
A flange portion 17 made of a resin molded product was formed. Further FIG.
As shown in (c), the collar 1 of the base 13 of the iron core 12
Urethane coating is applied to the portion sandwiched between 5 and φ0.04
A 2 mm lead wire 19 was wound 15,000 turns with a winding machine while applying a tension of 4 g to the lead wire 19 to form a coil 18. Thirty such samples were prepared for each Example and Comparative Example, and the withstand voltage of the coil 18 was evaluated in the same manner as in the initial withstand voltage evaluation. (Evaluation of surge withstand voltage) Using the iron cores 12 of the respective examples and comparative examples, the coil 1 was used in the same manner as in the evaluation of the withstand voltage after machining.
8 was formed, and a relay was assembled using the coil 18. Such a sample was prepared for each Example and Comparative Example by 30.
And a surge voltage of 1.2 × 50 μsec. Between the contact of the relay and the coil terminal. In the standard impulse voltage waveform, the peak value was repeatedly increased from 1500 V every 250 V and applied repeatedly, and a limit value at which dielectric breakdown occurred was measured.

Table 1 shows the above results.

[0032]

[Table 1]

As can be seen from Table 1, in Comparative Example 1, the withstand voltage after machining was lower than the initial withstand voltage, and the surge withstand voltage was also lower than those in Examples 1 to 9;
Is fixed to the fixing jig 16, the molding die 15 is attached, the lead wire 19 is wound, or the like.
The electrical insulation property of the metal was reduced. On the other hand, in Examples 1 to 9, there is almost no difference between the initial withstand voltage and the withstand voltage after machining, and the surge withstand voltage is higher than that of Comparative Example 1. Due to the high flexibility of the vapor-deposited polymer film, the occurrence of cracking and peeling of the polyimide vapor-deposited polymer film was suppressed even after an external force was applied by machining, and the electrical insulation of the iron core 12 could be maintained. It could be confirmed.

[0034]

As described above, the polyimide vapor-deposited polymer film of the present invention has at least one of the acid anhydrides represented by the chemical formulas (A) to (C) and the chemical formulas (D) to (F). Since it is formed by vapor deposition polymerization with at least one of the diamines, it is highly flexible, and is a polyimide vapor-deposited polymer film obtained by subjecting a substrate on which the polyimide vapor-deposited polymer film is formed to mechanical processing or the like to apply an external force. This can suppress the occurrence of cracks and peeling, and can improve the electrical insulation of the base material when an electromagnetic material is used as the base material.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a vapor deposition polymerization apparatus used to form a polyimide vapor deposition polymerization film of the present invention.

FIG. 2 is a perspective view showing an iron core used in Examples 1 to 9 and Comparative Example 1.

FIGS. 3 (a) to 3 (c) are front views showing respective steps of forming a coil from the above iron core.

Claims (2)

[Claims] 1. A method comprising forming at least one of the acid anhydrides represented by the following chemical formulas (A) to (C) and at least one of the diamines represented by the following chemical formulas (D) to (F) by vapor deposition polymerization. A polyimide-deposited polymer film, characterized in that it is formed. Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image 2. An acid anhydride comprising 3,3 ', 4,4'-bisphenyltetracarboxylic anhydride represented by the following chemical formula (G) and a diamine represented by the following chemical formula (H): 2. The polyimide vapor-deposited polymer film according to claim 1, wherein the film is formed using 2,2-bis [4- (4-aminophenoxy) phenyl] propane. Embedded image