JP2015028106A - Polyimide precursor varnish, polyimide resin, and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide precursor varnish for obtaining a polyimide resin having both excellent insulation characteristics and heat resistance and also having flexibility.SOLUTION: A polyimide precursor varnish of the invention comprises a polyimide precursor, and a composition comprising a solvent. The polyimide precursor is obtained by polycondensation of diamine of chemical formula (1) and chemical formula (2) in a specific blending ratio and acid dianhydride of chemical formula (3) in a specific blending ratio.

Description

  The present invention relates to a polyimide precursor varnish and a polyimide resin. Moreover, it is related with the use which uses the said polyimide precursor varnish or a polyimide resin.

  Electric wire wiring, cables, and the like have a configuration in which a metal conductor is coated with an insulating coating layer and a conductor portion is protected. Various products have been developed for the insulation coating layer depending on the application. For insulation coating layer applications such as electric wires and motor windings that require high heat resistance exceeding 200 ° C, polyamide, polyamideimide, polyester Engineering plastics such as imide and polyimide are used. Among these, polyimide having excellent heat resistance, electrical insulation, and mechanical strength is used for an insulating coating layer of enameled wire, a base film of an adhesive tape, a base film of a flexible printed wiring board, and the like.

  Commercially available polyimides include 4,4'-diaminodiphenyl ether and pyromellitic dianhydride KAPTON (registered trademark, manufactured by DuPont), 4,4'-diaminodiphenyl ether and 3,3 ', 4. There are Upilex (registered trademark, manufactured by Ube Industries), AURUM (registered trademark, manufactured by Mitsui Chemicals), which is a polyimide composed of 4'-biphenyltetracarboxylic dianhydride.

化学式（Ｉ）中、Ｒは炭素数２以上の脂肪族基、環式脂肪族基、単環式芳香族基、縮合多環式芳香族基、芳香族基が直接又は架橋員により相互に連結された非縮合多環式芳香族基からなる群より選ばれた４価の基を示し、Ｘは単結合、硫黄原子、スルホン基、カルボニル基、イソプロピリデン基又はヘキサフルオロイソプロピリデン基の２価の基を示す。 Patent Document 1 discloses an insulating material in which a polyimide having a repeating structural unit represented by chemical formula (I) is heated and melted in an extruder at a temperature range of 300 to 450 ° C. to coat a conductor, and then cooled and solidified to form an insulator. An electrical wire manufacturing method is described.

In chemical formula (I), R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group directly or by a cross-linking member. Represents a tetravalent group selected from the group consisting of a non-condensed polycyclic aromatic group, and X represents a divalent group of a single bond, a sulfur atom, a sulfone group, a carbonyl group, an isopropylidene group or a hexafluoroisopropylidene group. The group of is shown.

  Patent Document 2 discloses an insulated wire using p-phenylenediamine and 4,4′-diaminodiphenyl ether as diamine and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as acid dianhydride. Has been.

  Patent Document 3 includes 1 to 99% by weight of a polyimide soluble in a solvent in order to obtain a material having heat resistance that can be applied to heat-resistant adhesives, coated electric wire materials, etc., and excellent mechanical properties. A resin composition comprising 1 to 99% by weight of thermoplastic polyamide has been proposed. In the examples, a resin composition having a mixing ratio of polyimide: polyamide = 4-7: 3-6 is disclosed. Moreover, as a polyimide soluble in a solvent, two kinds of acid dianhydrides (pyromellitic dianhydride and 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride) and two kinds of diamines are used. Polyimide (AI) composed of (4,4′-diaminodiphenylmethane and 4,4′-diaminodiphenyl ether) and one kind of acid dianhydride (3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride) And polyimide (AII) composed of two kinds of diamines (4,4′-diaminodiphenyl ether and 4,4′-diaminodiphenylsulfone).

  In Patent Document 4, the first insulating layer and the third insulating layer are made of polyimide resin, and the second insulating layer is selected from the group consisting of polyamideimide resin, polyesterimide resin, polyetherimide resin and H-type polyester resin. A multilayer insulated wire made of one or more kinds of resins has been proposed. In Examples, an insulating layer in which an insulating layer having a kapton structure made of 4,4'-diaminodiphenyl ether and pyromellitic dianhydride and a second insulating layer are stacked is disclosed.

JP-A-2-210713 JP 7-37439 A JP-A-9-77972 JP 2013-33669 A

  The remarkable development of the electronics industry has been supported by the development of various electronic components and materials for electronic components. As described above, excellent materials have been proposed for the insulating materials by vigorous research and development. However, there is a demand for higher performance materials on the market. For example, a material that is not affected by xylene contained in an impregnating varnish for fixing a winding motor is required. Further, there is a demand for a material having excellent heat resistance that can withstand use in a higher temperature environment while having excellent insulating properties. For example, in applications such as an insulating coating layer of an insulated wire, a material having flexibility and excellent followability is required.

  In addition, in the above, although the subject in an insulation coating layer etc. was described, the same subject may arise also about the various uses for which the said characteristic is calculated | required.

  The present invention has been made in view of the above background, and the object thereof is a polyimide resin having xylene resistance, excellent insulating properties and heat resistance, and excellent flexibility, It is providing the polyimide precursor varnish for obtaining the said polyimide resin, and these uses.

［２］前記ポリイミド前駆体において、前記ジアミンと前記酸二無水物からなる繰り返しユニットの全ユニット中、化学式（４）と化学式（５）の合計のユニットにおいて、化学式（４）のユニット数をｍ、化学式（５）のユニット数をｎとしたときに、数式（１）を満たす［１］に記載のポリイミド前駆体ワニス。

＜数１＞ ０．４≦ｍ／（ｎ＋ｍ）≦０．９ 数式（１）
但し、式中のｍ、ｎは１以上の整数。
［３］前記ジアミン成分Ａおよび前記ジアミン成分Ｂ以外の前記ジアミンが、パラフェニレンジアミン、メタフェニレンジアミン、２，２’−ジメチル−４，４’−ジアミノビフェニル、４，４’−ビス（３−アミノフェノキシ）ビフェニル、３，３’−ジメチル−４，４’−ジアミノビフェニル、４，４’−ジアミノ−３，３’−ビフェニルジオール、２，２’−ビス（トリフルオロメチル）−１，１’−ビフェニル−４，４’−ジアミン、２，４−トルエンジアミン、２，６−トルエンジアミン、３，４−トルエンジアミン、２，３−トルエンジアミン、１，５−ジアミノナフタレン、３，３’−ジアミノジフェニルスルホン、および４，４’−ジアミノジフェニルスルホンの少なくともいずれかである［１］又は［２］に記載のポリイミド前駆体ワニス。
［４］前記ジアミンの全量に対して、前記ジアミン成分Ａを３７モル％以上、８７モル％以下含み、前記ジアミン成分Ｂを１３モル％以上、６３モル％以下含む［１］〜［３］のいずれかのポリイミド前駆体ワニス。
［５］前記ジアミン成分Ａおよび前記ジアミン成分Ｂ以外の前記ジアミンが、パラフェニレンジアミン、又は４，４’−ビス（３−アミノフェノキシ）ビフェニルであり、それぞれ独立に全ジアミン中１０モル％以下含まれている［１］〜［４］のいずれかのポリイミド前駆体ワニス。
［６］前記ポリイミド前駆体は、前記ジアミンが、前記ジアミン成分Ａおよび前記ジアミン成分Ｂの２種類からなり、前記酸二無水物が、前記ピロメリット酸二無水物からなる［１］〜［５］のいずれかのポリイミド前駆体ワニス。
［７］前記組成物は、前記ポリイミド前駆体の全樹脂固形分に対して、化学式（６）で表されるモノマーおよび化学式（７）〜（９）で表されるオリゴマーの少なくともいずれかが０．１〜２０質量％の範囲で含まれている［１］〜［６］のいずれかのポリイミド前駆体ワニス。

但し、式中のｐは０〜９の整数を示す。

但し、式中のｑは０〜９の整数を示す。

但し、式中のｒは１〜５の整数を示し、ｓは０〜４の整数を示す。
［８］［１］〜［７］のいずれかのポリイミド前駆体ワニスから得られた成形物をイミド化することにより形成したポリイミド樹脂。
［９］導体と、前記導体を被覆する絶縁被覆層と、を具備する絶縁電線であって、
前記絶縁被覆層の少なくとも一部が、［１］〜［７］のいずれかのポリイミド前駆体ワニスから得られた成形物をイミド化することにより形成したポリイミド樹脂からなる絶縁電線。
［１０］前記絶縁被覆層は、厚さが１μｍ以上、５００μｍ以下である［９］に記載の絶縁電線。
［１１］前記絶縁被覆層は、最外層に厚さ１μｍ以上、５００μｍ以下であり、ガラス転移温度が５０℃以上の熱可塑性ポリイミド層が積層された［９］又は［１０］に記載の絶縁電線。
［１２］［１］〜［７］のいずれかのポリイミド前駆体ワニスから得られた塗膜をイミド化することにより形成したフィルムを備える耐熱フィルム。
［１３］［１２］に記載の耐熱フィルムの片面、若しくは両面に厚さ５０ｎｍ以上、２ｍｍ以下の粘着層が形成された粘着テープ。
［１４］［１２］に記載の耐熱フィルムの片面、若しくは両面に厚さ１μｍ以上、１ｍｍ以下であり、ガラス転移温度が５０℃以上の熱可塑性樹脂層が形成された接着フィルム。
［１５］［１２］に記載の耐熱フィルムの片面、若しくは両面にエポキシ、又は熱可塑性ポリイミドから選ばれる接着層が形成され、且つ前記接着層を介して金属箔が積層された積層板。 As a result of extensive studies by the present inventors, it has been found that the problems of the present invention can be solved in the following modes, and the present invention has been completed.
[1] A polyimide precursor varnish comprising a composition comprising a polyimide precursor and a solvent,
The polyimide precursor is obtained by polycondensation of diamine and acid dianhydride, and the diamine component A represented by the chemical formula (1) is 27 to 87 mol% with respect to the total amount of the diamine. The diamine component B represented by the chemical formula (2) is contained in an amount of 73 to 13 mol%, and the total of the diamine component A and the diamine component B is 80 mol% or more in the total diamine, and the acid dianhydride is It is a pyromellitic dianhydride represented by the chemical formula (3), and the total of the diamine is 47.5 to 52.5 mol% with respect to the total of the diamine and the acid dianhydride. The polyimide precursor varnish whose sum total is 52.5-47.5 mol%.

[2] In the polyimide precursor, among all the repeating units composed of the diamine and the acid dianhydride, in the total unit of the chemical formula (4) and the chemical formula (5), the number of units of the chemical formula (4) is m. The polyimide precursor varnish according to [1], which satisfies Formula (1), where n is the number of units in Chemical Formula (5).

<Equation 1> 0.4 ≦ m / (n + m) ≦ 0.9 Formula (1)
However, m and n in the formula are integers of 1 or more.
[3] The diamine other than the diamine component A and the diamine component B is paraphenylenediamine, metaphenylenediamine, 2,2′-dimethyl-4,4′-diaminobiphenyl, 4,4′-bis (3- Aminophenoxy) biphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-3,3′-biphenyldiol, 2,2′-bis (trifluoromethyl) -1,1 '-Biphenyl-4,4'-diamine, 2,4-toluenediamine, 2,6-toluenediamine, 3,4-toluenediamine, 2,3-toluenediamine, 1,5-diaminonaphthalene, 3,3' -The polyimide precursor varnish according to [1] or [2], which is at least one of diaminodiphenylsulfone and 4,4′-diaminodiphenylsulfone
[4] From [1] to [3], the diamine component A is contained in an amount of 37 mol% to 87 mol% and the diamine component B is contained in an amount of 13 mol% to 63 mol% with respect to the total amount of the diamine. Any polyimide precursor varnish.
[5] The diamine other than the diamine component A and the diamine component B is paraphenylenediamine or 4,4′-bis (3-aminophenoxy) biphenyl, and each independently contains 10 mol% or less in the total diamine. The polyimide precursor varnish according to any one of [1] to [4].
[6] In the polyimide precursor, the diamine is composed of two types of the diamine component A and the diamine component B, and the acid dianhydride is composed of the pyromellitic dianhydride [1] to [5]. ] The polyimide precursor varnish in any one of.
[7] In the composition, at least one of the monomer represented by the chemical formula (6) and the oligomer represented by the chemical formulas (7) to (9) is 0 with respect to the total resin solid content of the polyimide precursor. The polyimide precursor varnish according to any one of [1] to [6], which is contained in the range of 1 to 20% by mass.

However, p in a formula shows the integer of 0-9.

However, q in a formula shows the integer of 0-9.

However, r in a formula shows the integer of 1-5, and s shows the integer of 0-4.
[8] A polyimide resin formed by imidizing a molded product obtained from the polyimide precursor varnish of any one of [1] to [7].
[9] An insulated wire comprising a conductor and an insulating coating layer covering the conductor,
The insulated wire which consists of a polyimide resin in which at least one part of the said insulation coating layer formed by imidating the molded object obtained from the polyimide precursor varnish in any one of [1]-[7].
[10] The insulated wire according to [9], wherein the insulating coating layer has a thickness of 1 μm or more and 500 μm or less.
[11] The insulated wire according to [9] or [10], wherein the insulating coating layer has a thickness of 1 μm or more and 500 μm or less as an outermost layer, and a thermoplastic polyimide layer having a glass transition temperature of 50 ° C. or more is laminated. .
[12] A heat-resistant film comprising a film formed by imidizing a coating film obtained from the polyimide precursor varnish of any one of [1] to [7].
[13] An adhesive tape having an adhesive layer having a thickness of 50 nm or more and 2 mm or less formed on one side or both sides of the heat-resistant film according to [12].
[14] An adhesive film in which a thermoplastic resin layer having a thickness of 1 μm or more and 1 mm or less and a glass transition temperature of 50 ° C. or more is formed on one side or both sides of the heat-resistant film according to [12].
[15] A laminate in which an adhesive layer selected from epoxy or thermoplastic polyimide is formed on one side or both sides of the heat-resistant film according to [12], and metal foil is laminated via the adhesive layer.

  According to the present invention, a polyimide resin having xylene resistance, excellent insulation properties and heat resistance, and excellent flexibility, a polyimide precursor varnish for obtaining the polyimide resin, and uses thereof There is an excellent effect that can be provided.

The typical sectional view showing an example of the insulated wire concerning this embodiment. The typical sectional view showing an example of the adhesive tape concerning this embodiment.

  Hereinafter, an example of an embodiment to which the present invention is applied will be described. Needless to say, other embodiments are also included in the scope of the present invention as long as they meet the spirit of the present invention. In addition, the size and ratio of each member in the following drawings are for convenience of explanation, and do not necessarily match the actual ones. In the present specification, the description “any number A to any number B” includes the number A as a lower limit and the number B as an upper limit in the range.

[Polyimide precursor varnish, polyimide resin] The polyimide precursor varnish according to the present invention comprises at least a polyimide precursor and a composition containing a solvent. The polyimide precursor of the present invention is obtained by polycondensation of diamine and acid dianhydride, and satisfies the following conditions (i) to (iii).

（ｉｉ）ポリイミド前駆体を構成する酸二無水物は、化学式（３）で示されるピロメリット酸二無水物とする。

（ｉｉｉ）ジアミンと酸二無水物の合計に対して、ジアミンの合計が４７．５〜５２．５モル％、酸二無水物の合計が５２．５〜４７．５モル％となるようにする。 (I) The diamine constituting the polyimide precursor is 27 mol% or more of 4,4′-diaminodiphenylmethane (hereinafter also referred to as “diamine component A”) represented by the chemical formula (1) with respect to the total amount of diamine, 87 It is contained in an amount of 13 mol% or more and 73 mol% or less of 4,4′-diaminodiphenyl ether represented by the chemical formula (2) (hereinafter also referred to as “diamine component B”). These diamine component A and diamine component B are contained in a total of 80 mol% or more in the total diamine.

(Ii) The acid dianhydride constituting the polyimide precursor is pyromellitic dianhydride represented by the chemical formula (3).

(Iii) The sum of diamine and acid dianhydride is 47.5 to 52.5 mol%, and the sum of acid dianhydride is 52.5 to 47.5 mol% with respect to the total of diamine and acid dianhydride. .

  According to the present invention, by using a polyimide precursor that satisfies all of the above, by having a specific ratio in addition to the effects derived from the respective monomer structures, it surprisingly has xylene resistance and is excellent In addition, it is possible to provide a polyimide resin that has both excellent insulating properties and heat resistance and is excellent in flexibility, a polyimide precursor varnish for obtaining the polyimide resin, and uses thereof.

  In a conventional kapton skeleton polyimide structure obtained from pyromellitic dianhydride and 4,4'-diaminodiphenyl ether, the glass transition temperature is around 390 ° C. Moreover, there existed a problem that the linear expansion coefficient in 100-250 degreeC was large. Since the polyimide structure of Patent Document 1 has a 4,4′-bis (3-aminophenoxy) biphenyl structure, it has a feature that it is excellent in flexibility as an electric wire, but has a low imide group density. However, there was a problem regarding solvent resistance. Further, Patent Document 2 has a problem in that although the linear expansion coefficient can be reduced to 45 ppm / ° C. or less, the glass transition temperature is 400 ° C. or less.

  According to the present invention, it is possible to provide a polyimide resin that satisfies all of heat resistance, insulating properties, flexibility, and xylene resistance as described above. According to the present invention, when pyromellitic dianhydride of the chemical formula (3) is introduced as the acid dianhydride and the diamines of the chemical formulas (1) and (2) are used to obtain a polyimide resin, The imide group density can be lowered and the crystallinity can be improved while realizing the stiffening. As a result, it is possible to provide a polyimide resin having high Tg, solvent resistance, a low linear expansion coefficient, and flexibility.

  Specifically, by adopting the structure of the polyimide precursor, the imide group density can be relatively lowered to improve the solvent resistance. In addition, by adopting the polyimide precursor structure, it is possible to make the glass transition temperature 400 ° C or higher, realizing excellent high heat resistance, increasing the use resistance under high temperature environment, and durability. Can be increased. For example, it can be used for a long time even in an environment of about 250 ° C. Moreover, an elastic modulus can be 3 GPa or less, and a flexibility property can be improved. Moreover, since a linear expansion coefficient can be 50 ppm / degrees C or less, for example, the curvature improvement at the time of laminating | stacking with another members, such as a metal, can be aimed at. Therefore, the polyimide resin of the present invention can be suitably used for a wide range of applications including various electronic parts such as insulated wires, adhesive tapes, adhesive tapes, laminates with metals, heat resistant paints, and aerospace adhesives. .

  In addition, the glass transition temperature (Tg), elastic modulus, and linear expansion coefficient specified in the present invention are values obtained by the following measurement method. That is, the polyimide precursor varnish was coated, and the polyimide film having a dried coating thickness of 20 to 60 μm obtained by heating at 5 ° C./min and 300 ° C. for 1 hour in a nitrogen atmosphere was as follows: It means the value when measured by the method.

  In order to make the coating film thickness after drying of the polyimide film 20 to 60 μm, for example, the polyimide precursor varnish coating may be applied to 300 to 400 μm. Although the production method of the said polyimide film is not specifically limited, The following method is mentioned as an example. That is, the polyimide precursor varnish is applied on a glass plate with a 300-400 μm gap applicator using a desktop coating machine. Then, immediately using an explosion-proof dryer, the temperature is raised from room temperature to 5 ° C./min in a nitrogen atmosphere as described above, and held at 300 ° C. for 1 hour. Then, after sufficiently cooling by natural cooling, the polyimide film is peeled from the glass plate by being immersed in warm water for 24 hours. And it is produced so that the coating-film thickness after drying may be set to 20-60 micrometers by fully drying. In addition, the coating film thickness 20-60 micrometers after drying specifies measurement samples, such as said Tg, Comprising: The film thickness used for various uses is not limited.

  Moreover, in this specification, a glass transition temperature says the value measured with the following method. That is, the temperature dispersion measurement of the solid viscoelasticity of the polyimide film is performed under the condition of the measurement frequency of 1 Hz in the tensile mode using RSA-II manufactured by TA instruments, and the storage elastic modulus E ′ and the loss elastic modulus E ″ are measured. Then, a value derived from the peak value of the obtained loss tangent tan δ = E ″ / E ′ is defined as “glass transition temperature”.

  Further, the tensile elongation at break refers to a value measured by the following method. That is, the polyimide film was cut into a size of 140 mm in length × 10 mm in width, the actual measurement length was 100 mm (of which 20 mm at both ends was the pulling region), and the room temperature was set using an AUTOGRAPH AGS-100D manufactured by Shimadzu Corporation (23 The strip-shaped film sample is pulled at a speed of 50 mm / min. The value calculated from (length of polyimide film at break) / (original length of polyimide film) at this time is taken as the tensile elongation at break. The elastic modulus is a value obtained by (stress during elastic deformation) / (cross-sectional area of the original sample) / (value obtained by dividing the elongation of the sample by the original length of the sample).

＜数２＞ ０．４≦ｍ／（ｎ＋ｍ）≦０．９ 数式（１）
但し、式中のｍ、ｎは１以上の整数。
数式（１）を満たすことにより、高い耐熱性（高Ｔｇ）、低線膨張係数、機械強度の３つの特性をより効果的に発揮させることができる。本発明のポリイミド前駆体は、数式（２）を満たすことがより好ましい。
＜数３＞ ０．６５≦ｍ／（ｎ＋ｍ）≦０．８５ 数式（２） The polyimide precursor of the present invention is a unit of the chemical formula (4) in the total unit of the chemical formula (4) and the chemical formula (5) among all the repeating units composed of the diamine and the acid dianhydride constituting the polyimide precursor. When the number is m and the number of units of the chemical formula (5) is n, it is preferable to satisfy the formula (1).

<Equation 2> 0.4 ≦ m / (n + m) ≦ 0.9 Formula (1)
However, m and n in the formula are integers of 1 or more.
By satisfy | filling numerical formula (1), the three characteristics of high heat resistance (high Tg), a low linear expansion coefficient, and mechanical strength can be exhibited more effectively. As for the polyimide precursor of this invention, it is more preferable to satisfy | fill Numerical formula (2).
<Equation 3> 0.65 ≦ m / (n + m) ≦ 0.85 Formula (2)

  From the viewpoint of exhibiting the problems of the present invention more effectively, the lower limit of the diamine component A is preferably 38 mol% or more, more preferably 74 mol% or more, and 79 mol% or more. Is more preferably 84 mol% or more. On the other hand, the upper limit of the diamine component A is preferably 90 mol% or less, and more preferably 86 mol% or less. Moreover, it is preferable that the lower limit of the diamine component B is 14 mol% or more, and it is more preferable that it is 17 mol% or more. On the other hand, the upper limit value of the diamine component B is preferably 52 mol% or less, more preferably 42 mol% or less, and further preferably 30 mol% or less.

  Moreover, the polyimide precursor of this invention may contain other diamines other than the diamine component A and the diamine component B in the range which does not deviate from the meaning of this invention. Preferred examples of other diamines include paraphenylene diamine, metaphenylene diamine, 4,4′-bis (3-aminophenoxy) biphenyl, 2,2′-dimethyl-4,4′-diaminobiphenyl, 3,3 ′. -Dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-biphenyldiol, 2,2'-bis (trifluoromethyl) -1,1'-biphenyl-4,4'- Diamine, 2,4-toluenediamine, 2,6-toluenediamine, 3,4-toluenediamine, 2,3-toluenediamine, 1,5-diaminonaphthalene, 3,3′-diaminodiphenylsulfone, and 4,4 There may be mentioned at least one of '-diaminodiphenylsulfone. Among these, particularly preferred examples include paraphenylenediamine and 4,4'-bis (3-aminophenoxy) biphenyl. These are each independently preferably 10 mol% or less in the total diamine, more preferably 5 mol% or less, and even more preferably 2 mol% or less.

  As a preferable example of the polyimide precursor of the present invention, a polyimide precursor constituted only by units of chemical formula (4) and chemical formula (5) can be exemplified.

但し、式中のｐは０〜９の整数を示す。

但し、式中のｑは０〜９の整数を示す。

但し、式中のｒは１〜５の整数を示し、ｓは０〜４の整数を示す。 The composition which comprises the polyimide precursor varnish of this invention is the monomer represented by Chemical formula (6), and the oligomer represented by Chemical formula (7)-(9) with respect to the total resin solid content of a polyimide precursor. It is preferable to include at least one in the range of 0.1 to 20% by mass.

However, p in a formula shows the integer of 0-9.

However, q in a formula shows the integer of 0-9.

However, r in a formula shows the integer of 1-5, and s shows the integer of 0-4.

  By including at least one of the monomer (6) and the oligomers (7) to (9) in the composition, a desired property can be obtained according to various uses without impairing heat resistance / flexibility and xylene resistance. The viscosity can be easily adjusted. The viscosity of the polyimide precursor varnish can be reduced.

  Although the number average molecular weight of the polyimide precursor which concerns on this embodiment is not specifically limited, For example, it can be set as the range of 5,000-1 million. The number average molecular weight of the polyimide precursor can be measured by gel permeation chromatography (GPC).

  Next, the manufacturing method of a polyimide precursor varnish is demonstrated. First, the above-mentioned specific diamine and specific tetracarboxylic dianhydride are reacted to obtain a polyamic acid. Although the ratio at the time of the synthesis | combination of the acid dianhydride and diamine of a polyimide precursor is not specifically limited, The sum total of diamine component A and diamine component B is 47.5-52.5 mol with respect to the sum total of diamine and acid dianhydride. %, And the acid dianhydride is preferably copolymerized in a range satisfying 47.5 to 52.5 mol%. In addition, although the acid dianhydride which comprises the polyimide precursor of this invention is a pyromellitic dianhydride shown by Chemical formula (3), for the synthesis | combination of the monomer which comprises this pyromellitic dianhydride. In addition to pyromellitic dianhydride represented by the chemical formula (3), those synthesized using ring-opened types as represented by the chemical formulas (6) to (9) are also included.

  The polymerization can be carried out in a solid phase system, but is preferably carried out in a liquid phase system. In the liquid phase system, the polymerization concentration is, for example, about 5 to 50% by mass. The reaction solvent is not particularly limited, but preferably has a boiling point of 100 ° C. or higher. In general, a solvent used for polymerization of a polyimide precursor can be suitably used. For example, it dissolves at least one reactant, preferably both acid dianhydrides and diamines. Specific examples include N, N-dimethylformamide, N, N-dimethylacetamide, cresol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and tetramethylurea. These solvents can be used alone or in combination with other solvents such as benzonitrile, dioxane, xylene or toluene.

  The production of the polyimide precursor can be performed without using a catalyst, but a catalyst may be used as appropriate. The catalyst is not particularly limited as long as it does not depart from the spirit of the present invention. The amount of the catalyst used may be appropriately adjusted in consideration of the properties of the catalyst itself such as the volatility of the catalyst and the acid strength, and the reaction conditions.

  In the liquid phase reaction step, there are no particular limitations on the order and method of charging the raw materials, solvent, and other catalysts added as necessary. The reaction temperature is not particularly limited as long as the required number average molecular weight (Mn) can be obtained, but is usually 20 to 100 ° C. when polyamic acid is polymerized as a polyimide precursor. The reaction time is not limited to a range that is sufficient to obtain the required degree of polymerization. Further, the reaction is preferably performed in an inert gas atmosphere such as nitrogen. The solid content concentration in the reaction system (in the reactor) is not particularly limited, but is usually 5 to 50% by mass.

  The reaction apparatus used for the solid phase reaction is not particularly limited, but Super Blend (Sumitomo Heavy Industries, Ltd.), Aiko Chemical Mixer (Aikosha Seisakusho), Planetary Mixer (Inoue Seisakusho), Trimix ( And kneading machines such as those manufactured by Inoue Seisakusho.

  The concentration of the resin solid content in the polyimide precursor varnish is preferably 5 to 50% by mass, and more preferably 10 to 30% by mass from the viewpoint of improving the coatability. The solvent is not particularly limited, but is preferably a polar solvent. Examples of polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethyl sulfoxide, hexamethyl phosphor In addition to amide, N-methyl-2-pyrrolidone, dimethylsulfone, etc., these two or more mixed solvents, or these solvents and nonpolar solvents benzene, toluene, xylene, benzonitrile, dioxane, cyclohexane, 1, Examples thereof include a mixed solvent with 3,5-trimethylbenzene, 1,2,4-trimethylbenzene and the like.

  Arbitrary additives may be added to the polyimide precursor varnish of the present invention without departing from the gist of the present invention. For example, an adhesion assistant, an adhesive, an antioxidant, an ultraviolet absorber, a colorant, a crosslinking agent, or the like may be added. Moreover, you may add surface modifiers, such as a silane coupling agent.

  Although a crosslinking agent is not specifically limited in the range which does not deviate from the meaning of this invention, An epoxy, bismaleimide, and nadiimide can be illustrated as a suitable example. Heat resistance can be more effectively increased by adding a crosslinking agent. From the viewpoint of heat resistance and reactivity, it is preferable to add bismaleimide having a molecular weight of 600 or less.

  The polyimide precursor of the present invention may be used as a single type or as a mixture of a plurality of types. Furthermore, the polyimide precursor varnish of the present invention may be mixed with a polymer different from the polyimide precursor of the present invention within a range not departing from the gist of the present invention. That is, in the polyimide resin obtained from the polyimide precursor varnish, other polymers may be included without departing from the spirit of the present invention. Moreover, in the polyimide precursor varnish, what was partially imidized may be contained.

The polyimide resin of the present invention can be obtained by heating and dehydrating the polyimide precursor. For example, a polyimide film can be obtained by coating a polyimide precursor varnish that is a composition and heat-treating at a temperature increase of 5 ° C./min and 300 ° C. for 1 hour in a nitrogen atmosphere.
The polyimide precursor varnish of the present invention can be used to obtain films, sheets and various forms of molded articles having various film thicknesses. The polyimide resin of the present invention is formed by imidizing a molded product obtained from a polyimide precursor varnish. Here, the molded product is a coating film, a film, a sheet, a molded product, a gel film, or the like. Hereinafter, application examples of the polyimide precursor varnish or the polyimide resin of the present invention will be described.

[Insulated Wire] FIG. 1 is a schematic sectional view showing an example of the insulated wire of the present invention. The insulated wire 1 has a conductor 10 and an insulating coating layer 20 formed by an insulating coating layer. The conductor 10 is not particularly limited as long as it can function as an electric wire. For example, the conductor 10 is made of a conductive material such as oxygen-free copper, copper, aluminum, an aluminum alloy, or a combination thereof. The insulating coating layer 20 covers the conductor 10 and is made of a polyimide resin formed using a polyimide precursor varnish. Between the conductor 10 and the insulating coating layer 20, an adhesion layer that improves the bonding may be provided. In the example of FIG. 1, an example in which the insulating coating layer 20 is formed from one layer of polyimide resin is shown, but the insulating coating having a two-layer structure such as a first insulating coating layer and a second insulating coating layer is shown. A layer may be sufficient and the laminated structure of three or more layers may be sufficient. When a plurality of layers are laminated, a plurality of polyimide resins formed using the polyimide precursor varnish of the present invention may be laminated, or a laminate of another insulating layer and the polyimide resin of the present invention may be used. The other insulating layer is not particularly limited, but can be appropriately designed according to needs such as a material that improves the adhesion to the conductor 10 and a highly flexible material.

  The thickness of the insulating coating layer 20 can be arbitrarily set according to the application and is not particularly limited, but can be set to about 1 to 500 μm, for example. A more preferable lower limit value of the insulating coating layer 20 is 10 μm or more, and a more preferable range is 20 μm or more. The insulating coating layer 20 is obtained by applying a polyimide precursor varnish to the conductor 10, drying it, and baking it. Although the coating method is not particularly limited, a method of directly or indirectly coating the outer periphery of the conductor 10 can be exemplified. The polyimide precursor is converted into polyimide by baking. In the case where a plurality of insulating coating layers are laminated, it can be formed by repeating the coating and baking process. When an insulating coating layer other than the polyimide resin layer is laminated, a known forming method can be used as appropriate.

  A thermoplastic polyimide layer can be further laminated on the outermost periphery of the insulating coating layer 20. Although the thickness of this thermoplastic polyimide layer can be suitably designed according to a use, it can be suitably set as about 1-500 micrometers. The glass transition temperature of this thermoplastic polyimide layer is preferably 100 ° C. or higher from the viewpoint of heat resistance. From the viewpoint of improving heat resistance, it is preferable to add a crosslinking agent such as bismaleimide, epoxy, or nadiimide to the thermoplastic polyimide layer. The polyimide resin layer of the present invention can also be laminated on the outermost periphery.

  Although a baking process is not specifically limited, It is preferable to perform in an inert gas, for example, can be performed in nitrogen atmosphere. The heating condition is not particularly limited as long as it can be converted from the polyimide precursor to the polyimide, and examples include heating at about 200 to 400 ° C. for 1 minute to 10 hours. The conductor 10 and the insulating coating layer 20 described above have examples in which the cross section has a round cross section, but is not particularly limited, and may be a rectangular shape, an elliptical shape, or the like independently.

  According to the insulated wire of the present invention, since the polyimide resin obtained from the polyimide precursor varnish of the present invention is used for at least one layer of the insulating coating layer 20, the mechanical strength and flexibility are excellent. Therefore, it is excellent in followability and the inner conductor 10 can be appropriately protected even when subjected to a strong external force. Furthermore, since the polyimide resin of the present invention is excellent in chemical resistance and heat resistance, it can be suitably used even under severe conditions such as high temperature and high humidity.

[Heat-resistant film] The heat-resistant film of the present invention comprises a polyimide resin film formed by imidizing a coating film obtained from the polyimide precursor varnish of the present invention. It may be a single layer body made only of a polyimide resin film, or may be a laminated body in which a plurality of polyimide resin films are laminated. Moreover, the laminated film which laminated | stacked the polyimide resin film and the different kind of film may be sufficient. The thickness of the heat-resistant film can be appropriately set depending on the use, but is usually preferably 1 μm or more and 1 mm or less.

[Adhesive Tape] FIG. 2 is a schematic sectional view showing an example of the adhesive tape of the present invention. The adhesive tape 2 includes a heat resistant film 30 and an adhesive layer 31. An intermediate layer or the like that reinforces the bonding between the heat-resistant film 30 and the adhesive layer 31 may be provided. For the adhesive tape 2, for example, a heat resistant film 30 and an adhesive layer 31 having heat resistance are used in order to ensure heat resistance that can be used even in a high temperature region around 400 ° C.

  The heat-resistant film 30 includes a polyimide resin layer formed from at least the polyimide precursor varnish of the present invention. The heat resistant film 30 may be composed of a single layer or a plurality of polyimide resin layers, or may be a laminate of a layer made of another material and a polyimide resin layer. Other materials are not limited as long as they do not depart from the spirit of the present invention, and examples thereof include metal foils such as aluminum foil, metal layers, and plastic films. What is excellent in bondability with the polyimide resin layer formed from the polyimide precursor varnish of this invention and excellent in heat resistance is preferable.

  The adhesive layer 31 is not particularly limited as long as it can be bonded to the adherend and does not depart from the spirit of the present invention. Preferable examples of the adhesive layer 31 include a silicone adhesive, a rubber adhesive, and an acrylic adhesive. From the viewpoint of increasing the heat resistance of the adhesive layer 31, it is preferably thermosetting.

  The thickness and size of the pressure-sensitive adhesive tape 2 can be appropriately designed according to various uses. For example, the thickness of the heat resistant film 30 is preferably about 2 to 100 μm. The lower limit value of the heat resistant film 30 is more preferably 5 μm or more, and further preferably 10 μm or more. Further, the upper limit value of the heat resistant film 30 is more preferably 50 μm or less, and further preferably 30 μm or less. The thickness of the adhesion layer 31 can be set to, for example, about 50 nm to 2 mm. The adhesive strength can be adjusted by adjusting the thicknesses of the heat-resistant film 30 and the adhesive layer 31. By appropriately selecting the thickness, the material of the bonding layer, and the lamination form according to the required use, it is possible to provide a pressure-sensitive adhesive tape excellent in followability or a high-rigidity pressure-sensitive adhesive tape.

  Although the adhesive tape 2 can be manufactured by various methods, the following methods can be illustrated. That is, a gel film is obtained by continuously extruding or coating a polyimide precursor varnish in a film form on a rotating support. Next, the gel film is peeled from the support, and imidized by stretching, drying, and heat treatment to obtain the heat resistant film 30. Thereafter, the adhesive layer 31 is formed thereon by a conventionally known coating method. The coating method is not particularly limited, and examples thereof include a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater method, and a die coater method. The drying conditions of the coated pressure-sensitive adhesive may be appropriately adjusted depending on the pressure-sensitive adhesive to be used, but in general, it is dried for 10 seconds to 10 minutes in a temperature range of 80 to 200 ° C.

  The gel film referred to in the present invention is a film containing a polyimide precursor and / or a polyimide precursor mixed with a partially imidized polyimide resin, and a solvent. For example, the gel film has a film thickness of about 1 to 100 μm and a solvent content of about 1 to 70% by mass.

  In addition, the adhesive tape 2 is not limited to the example of FIG. 2, and can take various aspects. For example, a double-sided tape in which bonding layers are provided on both sides of the heat-resistant film 30 may be used. Moreover, it is good also as a structure which laminates | stacks a peeling film on the upper layer of the adhesion layer 31, and peels a peeling film at the time of use. Moreover, it can also be set as a roll-shaped adhesive tape. The size of the pressure-sensitive adhesive tape 2 of the present invention is not particularly limited, and includes a sheet-like one in addition to a so-called tape-like form having a strip shape. Further, the gel film itself obtained from the polyimide precursor varnish can be used as the adhesive tape 2 without providing the adhesive layer 31.

  According to the pressure-sensitive adhesive tape of the present invention, since the polyimide resin obtained from the polyimide precursor varnish of the present invention is used, it has excellent xylene resistance and heat resistance, and also has excellent flexibility. It can be applied to adherends of various shapes. For example, it is suitable as a masking tape used for heat equipment such as heat rolls and heaters, electrical insulation of members used under heating and pressure conditions, and as a protective tape for printed circuit boards in the field of semiconductor manufacturing processes.

[Adhesive Film] The adhesive film of the present invention comprises an adhesive layer and the heat-resistant film of the present invention. You may provide the intermediate | middle layer etc. which strengthen these joining between a heat-resistant film and an adhesive layer. For example, in order to ensure heat resistance that can be used even in a high-temperature region around 400 ° C., the adhesive film uses a heat-resistant film or an adhesive layer that has heat resistance.

  The adhesive layer is not particularly limited as long as it can be bonded to the adherend and does not depart from the gist of the present invention. From the viewpoint of heat resistance, the adhesive layer is composed of a thermoplastic resin layer having a glass transition temperature of 50 ° C. or higher. It is preferable. Although the upper limit of the glass transition temperature of a thermoplastic resin layer is not specifically limited, It is preferable to set it as 300 degrees C or less from a viewpoint of making the adhesiveness in low temperature favorable. Preferable examples of the adhesive layer include epoxy resin, acrylic resin, thermoplastic polyimide, and the like.

  The thickness and size of the adhesive film can be appropriately designed according to various uses. For example, the thickness of the heat resistant film is preferably about 2 to 100 μm. The lower limit of the heat resistant film is more preferably 5 μm or more, and further preferably 10 μm or more. Further, the upper limit of the heat resistant film is more preferably 50 μm or less, and further preferably 30 μm or less. The thickness of the adhesive layer can be appropriately designed according to the application, but is set to, for example, about 1 μm to 1 mm. More preferably, it is about 3-100 micrometers. The adhesive strength can be adjusted by adjusting the thickness of the heat resistant film and the adhesive layer.

  Although an adhesive film can be manufactured by various methods, after forming a heat-resistant film by the method similar to the said adhesive tape etc., the method of forming an adhesive layer on this by a conventionally well-known coating method can be illustrated. Although the coating method is not specifically limited, The method similar to the adhesion layer 31 can be illustrated.

  The adhesive film can take various forms. For example, it is good also as an adhesive film which provided the joining layer on both surfaces of the heat-resistant film. Moreover, it is good also as a structure which laminates | releases a peeling film on the upper layer of an adhesive layer, and peels a peeling film at the time of use. Moreover, it can also be set as a roll-shaped adhesive film. Moreover, the gel film itself obtained from the polyimide precursor varnish can also be utilized as an adhesive film without providing an adhesive layer.

  According to the adhesive film of the present invention, since the polyimide resin obtained from the polyimide precursor varnish of the present invention is used, it is excellent in xylene resistance and heat resistance, and also has low elastic properties and excellent flexibility. Therefore, it can be applied to adherends of various shapes. For example, it is suitable for the insulation of a circuit board or for a burley film or an interlayer adhesive film.

[Laminate] The laminate of the present invention comprises a heat-resistant film, an adhesive layer and a metal foil. You may provide the intermediate | middle layer etc. which strengthen these joining between a heat-resistant film and an adhesive layer. For example, in order to ensure heat resistance that can be used even in a high-temperature region around 400 ° C., a laminate having heat resistance in the heat-resistant film or adhesive layer is used. As a heat-resistant film, the same aspect as the heat-resistant film 30 described above can be given as a suitable example.

  The adhesive layer is not particularly limited as long as it can be bonded to the metal foil and the heat-resistant film and does not depart from the spirit of the present invention. Preferable examples of the adhesive layer include silicone adhesives, rubber adhesives, and acrylic adhesives. From the viewpoint of increasing the heat resistance of the adhesive layer, it is preferably thermosetting.

  The thickness and size of the laminate can be appropriately designed according to various uses. For example, as a suitable example of the thickness of the heat-resistant film and the thickness of the adhesive layer, the same configuration as the heat-resistant film and the adhesive layer described above can be given. Examples of the metal foil include aluminum foil, copper foil, and SUS foil. Although the thickness of metal foil can be suitably designed by a use, it is 5-210 micrometers, for example.

  Although a laminated body can be manufactured by various methods, for example, a heat resistant film is obtained by the same method as the heat resistant film 30 described above. Thereafter, an adhesive layer is formed thereon by a conventionally known coating method. Although the coating method is not specifically limited, The method similar to the adhesion layer 31 can be illustrated. In addition, a laminated body can take a various aspect. For example, it is good also as a laminated body which provided the metal foil on both surfaces of the heat-resistant film. Moreover, you may join the gel film itself obtained from the polyimide precursor varnish with metal foil, without providing an adhesive layer.

  According to the laminate of the present invention, since the polyimide resin obtained from the polyimide precursor varnish of the present invention is used, it is excellent in xylene resistance and heat resistance, and also in flexibility, so that a wide variety It can be applied to adherends of various shapes. Therefore, for example, it is suitable for use as a printed wiring board substrate.

Examples Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

[Example 1] (Preparation of polyimide precursor varnish) In a dimethylacetamide solvent, 4,4'-diaminodiphenyl ether (Wakayama Seika Co., Ltd.) (hereinafter referred to as "ODA"), 4,4'-diaminodiphenylmethane ( Two types of diamines (Mitsui Chemicals Co., Ltd.) (hereinafter referred to as “MDA220”) and pyromellitic dianhydride (Mitsubishi Gas Chemical Co., Ltd.) (hereinafter referred to as “PMDA”) Were blended at a molar ratio of ODA: MDA220: PMDA = 25: 25: 49.5. And the mixture was stirred for 4 hours or more, and the polyimide precursor varnish whose resin solid content ratio is 20-25 mass% was obtained.

(Preparation of Polyimide Film) The polyimide precursor varnish was applied on a glass plate with a 360 μm gap applicator using a desktop coating machine. Immediately after the coating, it was dried in a nitrogen atmosphere using an explosion-proof dryer. In drying, the temperature was raised from room temperature at 5 ° C./min and held at 300 ° C. for 1 hour. Then, it cooled naturally. After sufficiently cooling, the polyimide film was peeled off from the glass plate by being immersed in warm water for 24 hours to obtain a desired polyimide film sample. The film thickness after drying of the obtained polyimide film was 30 μm.

(Glass transition temperature evaluation (heat resistance evaluation)) The glass transition temperature was evaluated about the polyimide film produced by the above-mentioned method. In the measurement, the storage elastic modulus E ′ and the loss elastic modulus E ″ were evaluated by temperature dispersion measurement (tensile mode) of solid viscoelasticity, and the glass transition temperature was derived from the peak value of loss tangent tan δ = E ″ / E ′. . The measuring apparatus used RSA-III made from TA instruments, and determined with the following evaluation criteria.
A: 405 ° C. ≦ Tg
B: 400 ° C. ≦ Tg <405 ° C.
C: Tg <400 ° C.

(Linear expansion coefficient evaluation) The linear expansion coefficient (CTE) was evaluated about the polyimide film produced by the above-mentioned method. A sample cut into a size of 20 mm length × 4 mm width and chucked at both ends with a jig was loaded with a TMA-4000 manufactured by Mac Science Co., Ltd. in an air atmosphere at a load of 0.049 N and a temperature increase rate of 10 ° C./min. After measuring the amount of expansion and contraction, the average coefficient of linear expansion (CT) at 50 to 250 ° C. was calculated. The evaluation criteria were as follows.
A: C.I. T.A. E. ≤42 (ppm / ° C)
B: 42 (ppm / ° C.) <C. T.A. E. ≦ 50 (ppm / ° C)
C: 50 (ppm / ° C.) <C. T.A. E.

(Evaluation of elastic modulus and mechanical strength) The tensile mechanical strength of the prepared polyimide film was measured. A sample was cut into a size of 140 mm length × 10 mm width, and 20 mm portions at both ends were used as a tensile region (actual measurement length was 100 mm). By pulling a strip-shaped film sample at a speed of 50 mm / min, the elastic modulus and elongation at break were measured. As a measuring device, AUTOGRAPH AGS-100D manufactured by Shimadzu Corporation was used. The evaluation criteria for the elastic modulus were as follows.
A: Elastic modulus ≦ 2.5 GPa,
B: 2.5 GPa <elastic modulus ≦ 3.0 GPa
C: 3.0 GPa <elastic modulus,
Moreover, the evaluation criteria of the breaking elongation were as follows.
A: 37% ≦ breaking elongation B: 30 ≦ breaking elongation <37%
C: Elongation at break <30%

(Xylene resistance) The xylene resistance of the polyimide film produced by the method described above was evaluated. The sample was cut into a size of 140 mm length × 10 mm width, and a sample with a fixing jig at the upper end and a weight equivalent to 2.0 kg at the lower end was placed in a SUS container and suspended. The container was filled with xylene so as to fill up to the upper end of the sample, heated in a warm water tank (60 ° C.) together with the container, measured for the time until the film sample broke, and judged according to the following evaluation criteria.
A: Maintained for 10 seconds or more after immersion in a xylene solvent.
C: Breaked in less than 10 seconds after immersion in xylene solvent.

(Viscosity evaluation) Viscosity was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., TVE-25H type). The measurement temperature was 25 ° C. The number of revolutions was measured in a range of 1 to 100 rpm and a torque load of 20 to 80%.

[Example 2] Except that MDA220, two types of diamines of ODA and one type of acid dianhydride of PMDA were blended in a molar ratio of MDA220: ODA: PMDA = 37.5: 12.5: 49.5. Produced and evaluated a polyimide precursor varnish and a polyimide film in the same manner as in Example 1.

[Example 3] Except that MDA220, two types of diamines of ODA and one type of acid dianhydride of PMDA were blended in a molar ratio of MDA220: ODA: PMDA = 42.5: 7.5: 49.5. Produced and evaluated a polyimide precursor varnish and a polyimide film in the same manner as in Example 1.

Example 4 MDA220: ODA: pPD: PMDA 3 types of diamines of MDA220, ODA and paraphenylenediamine (MGC DuPont) (hereinafter referred to as “pPD”) and one type of PMDA acid dianhydride. = A polyimide precursor varnish and a polyimide film were prepared and evaluated in the same manner as in Example 1 except that they were blended at a molar ratio of 20: 25: 5: 49.5.

[Example 5] MDA220: ODA: 2 types of diamine, 1 type of PMDA acid dianhydride, and 1 type of tetracarboxylic acid represented by chemical formula (6) obtained by ring opening of PMDA. MDA220: ODA: PMDA : Ring opening PMDA = 42.5: 7.5: 49.3: A polyimide precursor varnish and a polyimide film were prepared and evaluated in the same manner as in Example 1 except that they were blended in a molar ratio of 42.5: 7.5: 49.3: 0.2. .

[Comparative Example 1] A polyimide precursor as in Example 1 except that one type of diamine of ODA and one type of acid dianhydride of PMDA were blended in a molar ratio of ODA: PMDA = 50: 49.5. A body varnish and a polyimide film were prepared and evaluated.

[Comparative Example 2] Except that MDA220, two types of diamines of ODA and one type of acid dianhydride of PMDA were blended in a molar ratio of MDA220: ODA: PMDA = 12.5: 37.5: 49.5. Produced and evaluated a polyimide precursor varnish and a polyimide film in the same manner as in Example 1.

[Comparative Example 3] A polyimide precursor as in Example 1 except that one diamine of MDA220 and one kind of PMDA acid dianhydride were blended in a molar ratio of MDA220: PMDA = 50: 49.5. A body varnish and a polyimide film were prepared and evaluated.

[Comparative Example 4] Two kinds of diamines of pPD and ODA, and acid dianhydride of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (manufactured by JFE Chemical Co., Ltd.) (hereinafter referred to as "BPDA") A polyimide precursor varnish and a polyimide film were prepared and evaluated in the same manner as in Example 1 except that one kind of product was blended at a molar ratio of pPDA: ODA: BPDA = 40: 10: 49.5.

[Comparative Example 5] One kind of diamine of 4,4'-diaminodiphenylsulfone (manufactured by Mitsui Chemical Fine Co., Ltd.) (hereinafter referred to as "4,4'-DAS") and one kind of PMDA acid dianhydride , 4,4′-DAS: PMDA = 50: 49.5 A polyimide precursor varnish and a polyimide film were prepared and evaluated in the same manner as in Example 1 except that they were blended in a molar ratio of 50: 49.5.

[Comparative Example 6] Three kinds of diamines of MDA220, ODA, 4,4'-bis (3-aminophenoxy) biphenyl (Mitsui Chemicals) (hereinafter referred to as "mBP"), PMDA acid dianhydride, Was prepared in the same manner as in Example 1 except that MDA220: ODA: mBP: PMDA = 42.5: 5: 2.5: 49.5 was added in a molar ratio. ,evaluated.

[Comparative Example 7] Example except that two types of MDA220 and ODA diamines and one type of PMDA acid dianhydride were blended in a molar ratio of MDA220: ODA: PMDA = 45: 5: 49.5. A polyimide precursor varnish and a polyimide film were prepared and evaluated in the same manner as in Example 1.

Table 1 shows the preparation ratio of the polyimide acid varnish, and Table 2 shows the physical property results.

  As for the polyimide film which concerns on a present Example, Tg was 405 degreeC or more and all the samples confirmed that it was high Tg. For example, Comparative Example 1 is a polyimide resin composed of MDA220 and PMDA, but Tg is 392 ° C., which is inferior to the example of the present invention. Also in Comparative Example 6 in which a part of MDA220 was changed to ODA and mBP, Tg was 399 ° C. On the other hand, in Comparative Example 7 using MDA220 and ODA as the diamine and using PMDA as the acid dianhydride, the Tg is 424 ° C., indicating that excellent heat resistance is obtained. However, the elongation is 19%, which indicates that there is a problem in mechanical resistance.

  The polyimide film according to this example has an elastic modulus of 3.0 GPa or less, more specifically, 2.5 GPa or less in any sample, and was found to have a low elastic property. For example, the elastic modulus of Comparative Example 4 is 7.0 GPa, whereas the elastic modulus of Example 1 is 2.5 GPa or less.

  According to this example, 4,4′-diaminodiphenylmethane and 4,4′diaminodiphenyl ether are specified ratios, and polyimide resin using pyromellitic dianhydride as an acid dianhydride is used in any polyimide film. Has a glass transition temperature of 400 ° C. or higher, an elastic modulus of 3.0 GPa or lower, a linear thermal expansion coefficient of 50 ppm / ° C. or lower, and an elongation of 30% or higher. In addition to excellent xylene resistance, it has heat resistance and low elastic properties. You can see that they have both. Further, a part of pyromellitic dianhydride represented by the chemical formula (3) as an acid dianhydride was converted to a ring-opening pyromellitic dianhydride (1,2,5,6-benzenetetramethylene represented by the chemical formula (6). In Example 5, which was the same as Example 3 except that it was changed to carboxylic acid), the varnish viscosity was measured while the glass transition temperature, linear expansion coefficient, elastic modulus, and elongation were the same as in Example 3. It was confirmed that it can be significantly reduced as compared with Example 3.

  The polyimide resin obtained from the polyimide precursor varnish of the present invention is excellent in xylene resistance, has excellent insulating properties and heat resistance, and is excellent in low elastic properties, so it is widely used in all applications where flexibility is required. can do. A preferred embodiment is a polyimide resin film obtained from the polyimide precursor varnish of the present invention. Examples of suitable applications include various electronic parts such as insulated wires, adhesive tapes, adhesive films, heat resistant paints, and aerospace adhesives. Also, for example, heat resistant films, printed wiring board substrates, various industrial sliding parts such as automobiles and aerospace, seamless belts for OA equipment, heat radiation members, electromagnetic wave shielding members, battery binders, solar cell members It is suitable as a dental member, an insulating protective material for a transparent conductor, a conductive paste, an insulating paste, a semiconductor protective film, a semiconductor sealing material, a medical adhesive, a radiation resistant member, a flexible display substrate, and a resin modifier. In addition, since low transmission loss and low dielectric constant can be realized, it is particularly suitable for applications such as insulated wires or windings.

DESCRIPTION OF SYMBOLS 1 Insulated electric wire 2 Adhesive tape 10 Conductor 20 Insulation coating layer 30 Heat-resistant film 31 Adhesive layer

Claims (15)

A polyimide precursor varnish comprising a polyimide precursor and a composition containing a solvent,
The polyimide precursor is obtained by polycondensation of diamine and acid dianhydride,
The diamine component A represented by the chemical formula (1) is contained in an amount of 27 to 87 mol% and the diamine component B represented by the chemical formula (2) is contained in an amount of 73 to 13 mol% based on the total amount of the diamine.
And the sum total of the said diamine component A and the said diamine component B shall be 80 mol% or more in all the diamines,
The acid dianhydride is pyromellitic dianhydride represented by the chemical formula (3),
The polyimide precursor whose total of the said diamine is 47.5-52.5 mol% and the sum of the said acid dianhydride is 52.5-47.5 mol% with respect to the sum total of the said diamine and the said acid dianhydride. Body varnish.

In the polyimide precursor, among all the units of the repeating unit composed of the diamine and the acid dianhydride, in the total unit of the chemical formula (4) and the chemical formula (5), the number of units of the chemical formula (4) is m, The polyimide precursor varnish of Claim 1 which satisfy | fills Numerical formula (1) when the unit number of 5) is set to n.

<Equation 1> 0.4 ≦ m / (n + m) ≦ 0.9 Formula (1)
However, m and n in the formula are integers of 1 or more.   The diamine other than the diamine component A and the diamine component B is paraphenylene diamine, metaphenylene diamine, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-bis (3-aminophenoxy). Biphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4′-diamino-3,3′-biphenyldiol, 2,2′-bis (trifluoromethyl) -1,1′-biphenyl -4,4'-diamine, 2,4-toluenediamine, 2,6-toluenediamine, 3,4-toluenediamine, 2,3-toluenediamine, 1,5-diaminonaphthalene, 3,3'-diaminodiphenyl The polyimide precursor according to claim 1 or 2, which is at least one of sulfone and 4,4'-diaminodiphenyl sulfone. Varnish.   The diamine component A is contained in an amount of 37 mol% or more and 87 mol% or less, and the diamine component B is contained in an amount of 13 mol% or more and 63 mol% or less with respect to the total amount of the diamine. The polyimide precursor varnish as described.   The diamine other than the diamine component A and the diamine component B is paraphenylenediamine or 4,4′-bis (3-aminophenoxy) biphenyl, and each diamine component is independently contained in an amount of 10 mol% or less in the total diamine. The polyimide precursor varnish of any one of Claims 1-4.   6. The polyimide precursor according to any one of claims 1 to 5, wherein the diamine is composed of two types of the diamine component A and the diamine component B, and the acid dianhydride is composed of the pyromellitic dianhydride. The polyimide precursor varnish as described in the item. In the composition, with respect to the total resin solid content of the polyimide precursor, at least one of the monomer represented by the chemical formula (6) and the oligomer represented by the chemical formulas (7) to (9) is 0.1 to 0.1. The polyimide precursor varnish according to claim 1, which is contained in a range of 20% by mass.

However, p in a formula shows the integer of 0-9.

However, q in a formula shows the integer of 0-9.

However, r in a formula shows the integer of 1-5, and s shows the integer of 0-4.   The polyimide resin formed by imidating the molded article obtained from the polyimide precursor varnish of any one of Claims 1-7. Conductors,
An insulated wire comprising an insulating coating layer covering the conductor,
The insulated wire which consists of a polyimide resin in which at least one part of the said insulation coating layer formed by imidating the molding obtained from the polyimide precursor varnish of any one of Claims 1-7.   The insulated wire according to claim 9, wherein the insulating coating layer has a thickness of 1 μm or more and 500 μm or less.   11. The insulated wire according to claim 9, wherein the insulating coating layer has a thickness of 1 μm or more and 500 μm or less on the outermost layer, and a thermoplastic polyimide layer having a glass transition temperature of 50 ° C. or more is laminated.   A heat-resistant film provided with the film formed by imidizing the coating film obtained from the polyimide precursor varnish of any one of Claims 1-7.   An adhesive tape having an adhesive layer having a thickness of 50 nm or more and 2 mm or less formed on one side or both sides of the heat-resistant film according to claim 12.   An adhesive film in which a thermoplastic resin layer having a thickness of 1 μm or more and 1 mm or less and a glass transition temperature of 50 ° C. or more is formed on one side or both sides of the heat-resistant film according to claim 12.   The laminated board by which the contact bonding layer chosen from the epoxy or the thermoplastic polyimide was formed in the single side | surface or both surfaces of the heat-resistant film of Claim 12, and the metal foil was laminated | stacked through the said contact bonding layer.

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