JPS6211727A - Aromatic polyimide and composition thereof - Google Patents

Abstract

PURPOSE:To produce the titled polyimide soluble in organic polar solvent and suitable for varnish, etc., by polymerizing an acid component composed mainly of biphenyltetracarboxylic acid and a diamine component composed mainly of di(aminophenoxy) benzene, and imidating the polymer. CONSTITUTION:The objective polyimide having a logarithmic viscosity of 0.2-5.0 can be produced by heating (A) an aromatic tetracarboxylic acid component containing preferably >=80 mol% biphenyltetracarboxylic acid and (B) nearly equimolar amount of an aromatic diamine component containing preferably >=80mol% di(aminophenoxy)benzene of formula in an organic polar solvent (e.g. N, N-dimethyl sulfoxide) e.g. at 100-300 deg.C, thereby causing the polymerization imidation reaction. USE:The polymer is dissolved in an organic polar solvent at a concentration of 1-30wt% and used as a varnish.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a specific aromatic polyimide that has excellent solubility in organic polar solvents and excellent heat resistance.

The aromatic polyimide of the present invention has excellent electrical properties, mechanical properties, etc., as well as excellent solubility in organic solvents and heat resistance, so it can be used for electrical insulation of various electrical or electronic parts. The aromatic polyimide composition (face) of the present invention for forming a protective film can be easily prepared, and the aromatic polyimide composition can also be applied to the surfaces of various electrical or electronic components to provide electrical insulation. It is possible to form a protective film for

[Description of known technology]

The use of aromatic polyimide as an electrically insulating protective film (such as an interlayer insulating film) is known in the electrical or electronic materials industry, for example, in JP-A-48-34686 and JP-A-49-40077. As shown in , polyimide can be used as a material for forming insulating films for solid-state devices, passivation films, and interlayer insulating films for semiconductor integrated circuits due to its excellent properties such as heat resistance and insulating properties. , various proposals have already been made.

However, since aromatic polyimide is generally difficult to dissolve in organic solvents, a solution of an aromatic polyimide precursor (aromatic polyamic acid) is used to form a coating film, and then dried and imide coated. In order to form a protective film made of aromatic polyimide, it is necessary to heat-treat the coated film at a fairly high temperature for a long time to form a protective film made of aromatic polyimide at a relatively low temperature. However, there was a problem in that the electrical or electronic materials themselves to be protected would be thermally degraded.

On the other hand, as aromatic polyimides soluble in organic polar solvents, for example, polyimides such as those described in Japanese Patent Publication No. 57-41491 are known, and these aromatic polyimides generally have considerable solubility and Although it has heat resistance, it is not necessarily substantially satisfactory; for example, it takes a long time to prepare a polyimide solution, or it is difficult to remove a polyimide film once formed on the surface of an article. There were problems when using it as various protective films, such as that it was not easy to use.

[Means for solving problems]

As a result of intensive research to provide an aromatic polyimide that has both excellent solubility and heat resistance, the present inventors found that
The aromatic polyimide obtained by polymerizing and imidizing biphenyltetracarboxylic acids and di(aminophenoxy)benzenes has excellent solubility in organic polar solvents and high heat resistance. The present invention was completed based on the discovery that

That is, the present invention provides an aromatic tetracarboxylic acid component mainly composed of biphenyltetracarboxylic acids and an aromatic diamine component mainly composed of di(aminophenoxy)benzenes represented by the following, by polymerization and imidization. The obtained soluble aromatic polyimide is provided.

Further, the present invention provides an aromatic polyimide composition in which the above-mentioned aromatic polyimide is uniformly dissolved in an organic polar solvent.

[Detailed description of the invention]

The aromatic polyimide of the present invention preferably contains an aromatic tetracarboxylic acid component containing biphenyltetracarboxylic acids, preferably 80% or more by mole, and di(aminophenoquine)benzenes represented by the general formula, preferably 80% by mole or more. The aromatic diamine component containing at least mol% of the aromatic diamine component is mixed in approximately equimolar amounts in an organic polar solvent at a fairly high temperature (preferably at a temperature of about 100 to 300°C, particularly preferably at a temperature of about 14°C).
0 to 250°C) and polymerization and imidization in one step, or the above two components are mixed in approximately equimolar amounts in an organic polar solvent, preferably at a temperature of about 80°C or less. Soluble aromatic polyimide produced by polymerizing aromatic polyamic acid (precursor of aromatic polyimide) at a temperature of 0 to 60 °C, in particular, and imidizing the aromatic polyamic acid under appropriate conditions. It is.

The above biphenyltetracarboxylic acids include 3.3
", 4.4° ~ biphenyltetracarboxylic acid or its acid dianhydride, 2,3.3", 4'-biphenyltetracarboxylic acid or its acid dianhydride, or the above aromatic tetracarboxylic acid. It may also be an esterified product or a salt. In the present invention, 2,3.3',4'-biphenyltetracarboxylic acid or its acid dianhydride is most suitable because the resulting aromatic polyimide has extremely good solubility.

The aromatic tetracarboxylic acid component includes a portion of the biphenyltetracarboxylic acids, for example, 3.3',
4.4'-benzophenonetetracarboxylic acid or its acid dianhydride, 2.3', 4°-benzophenonetetracarboxylic acid or its acid dianhydride, pyromellitic acid or other acid dianhydrides, etc. Aromatic tetracarboxylic acids can be substituted and used together with the above-mentioned biphenyltetracarboxylic acids. The proportion of the above-mentioned r and other aromatic tetracarboxylic acids j to be used is preferably less than about 20 mol%, particularly less than 10 mol%, based on the total aromatic tetracarboxylic acid component.

In addition, examples of the di(aminophenoxy)benzenes j represented by the above general formula, which are the main components of the aromatic diamine component, include l,4-di(4-aminophenoxy)benzene, 1.3 -di(4-aminophenoxy)benzene, 1.4-di(3-7minophenoxy)benzene, 1-(p-aminophenoxy)-4-(o-aminophenoxy)benzene, etc. As for di(aminophenoxy) and benzenes, at least one hydrogen of the benzene ring of the above-mentioned aromatic diamine compound is a suitable substituent (for example, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, or a methoxy group). , an alkoxy group such as an ethoxy group).

The aromatic diamine component includes a portion of the di(aminophenoxy)benzenes, such as paraphenylenediamine, metaphenylenediamine, 2,4-diaminotoluene, 4,4''-diaminodiphenyl ether, 4,4
゛-Diaminodiphenylmethane, 0-)lysine, 1.4
-Bis(4-aminophenoxy)benzene, other aromatic diamine compounds such as 0-)lysine sulfone, etc. can be substituted and used together with the di(aminophenoxy)benzenes. The proportion of the above-mentioned "other aromatic diamine compound" to be used is preferably less than about 20 mol%, particularly less than 10 mol%, based on the total aromatic diamine component.

Examples of the organic polar solvent used in the polymerization include sulfoxide solvents such as N,N-dimethylsulfoxide and N,N-diethylsulfoxide, and formamides such as N,N-dimethylformamide and N,N-diethylformamide. system solvent, N,N-dimethylacetamide,
Formamide solvents such as N,N-diethylformamide, N-methyl-2- and lolidone, pyrrolidone solvents such as N-vinyl-2-pyrrolidone, hexamethylene sulfoxide, T-butyrolactone, etc., or phenol, 0-lm Examples include phenolic solvents such as - or p-cresol, xylenol, halogenated phenols (parachlorophenol, orthochlorophenol, parabromophenol, etc.), and catechol.

The aromatic polyimide of the present invention is a polymer with a high molecular weight, for example, a concentration of 0.5 g/100 gu! solvent(
The logarithmic viscosity (indicating the degree of polymerization of the polymer) measured at a measurement temperature of 30°C in a solution of N-methyl-2-pyrrolidone) is from 0.2 to 5.0, in particular 0.3 ~
It is preferably about 3.0.

The aromatic polyimide of the present invention can be produced using an organic polar solvent similar to the organic polar solvent used in the above-mentioned polymerization, or a mixture of these organic polar solvents partially containing xylene, ethyl cellosolve, diglyme, dioxane, etc. Since aromatic polyimides dissolve very easily in solvents in a short time, aromatic polyimides can be dissolved in organic polar solvents at concentrations of about 1 to 30% by weight, especially 3 to 25% by weight.
A solution of an aromatic polyimide that is uniformly dissolved in weight% and has a rotational viscosity of about 0.1 to 100,000 voices at 25°C, particularly 1 to 10,000 voices (to be used as a varnish or a dope solution for film formation); That is, the aromatic polyimide composition j of the present invention can be prepared.

The aromatic polyimide composition of the present invention may be a polymerization solution of an aromatic polyimide obtained by polymerizing and imidizing monomer components in one step in an organic polar solvent as described above, or It may be diluted to an appropriate concentration with the same organic polar solvent as the polymerization solvent. Alternatively, the aromatic polyimide composition of the present invention can also be prepared by dissolving the aromatic polyimide powder, which has been isolated as a powdery precipitate from the above-mentioned polymerization solution, in the above-mentioned organic polar solvent.

The aromatic polyimide composition of the present invention can be coated, for example, on the surface of an object to be coated (circuit board, optical sensor, etc.) by an appropriate method using a spin coating machine or a printing machine at room temperature or under heating. By applying the composition to a uniform thickness to form a coating film of the composition (aromatic polyimide solution), and then drying the coating film at a temperature of about 50°C or higher, particularly 60 to 250°C, transparent A solidified film of aromatic polyimide can be produced.

In the aromatic polyimide composition of the present invention, especially when a sulfoxide solvent, a formamide solvent, an acetamide solvent, a pyrrolidone solvent, or an amide solvent such as hexamethylene phosphoamide is used as the organic polar solvent. For this, the drying temperature is set to about 60-200℃.
It is suitable because it can be carried out at a relatively low temperature, particularly 80 to 180°C.

〔Example〕

Example 1 N-methyl-2-pyrrolidone (NMP) 18.0ml
1.64 g of d,2,3.3',4'-hyphenyltetracarboxylic dianhydride and 1.64 g of 14-di(4-aminophenoxy)benzene were added, and the mixture was stirred while flowing nitrogen gas. The reaction solution was heated at a reaction temperature of 20°C.
The mixture was held for 5 hours to perform polymerization and produce aromatic polyamic acid.

Next, add NMP to this aromatic polyamic acid solution.
55.8mI! , and then acetic anhydride 11.
14 g and 4.26 g of pyridine were added and heated at 50°C.
Aromatic polyimide was produced by a time imidization reaction, and methanol was added to this solution to precipitate the produced aromatic polyimide, which was filtered to obtain aromatic polyimide powder.

About this aromatic polyimide powder, about 30 ° C.
Logarithmic viscosity (concentration; 0.5 g/100 ml)
Solvent and measurement temperature: 30°C) were measured.

Further, the aromatic polyimide powder obtained as described above was dissolved in NMP at about 30° C. to prepare a uniform aromatic polyimide solution having a concentration of about 14% by weight.

Next, this aromatic polyimide solution was applied onto the glass coated with SiO□ using a spin coating machine (1000 ~
3000 rpm) and heated and dried at 80° C. for 60 minutes to form a thin film made of aromatic polyimide with a thickness of 10 μm.

Cut out 1 ci of this thin film and get 50mj! 2 in NMP of
The solubility at 5°C (time taken until the test piece stops dissolving) was measured.

Further, the thermal decomposition onset temperature of the thin film heat-treated in air at 350° C. for 30 minutes was measured using a thermogravimetric analyzer (manufactured by DuPont, Model 951).

These measurement results (logarithmic viscosity, solubility and onset of thermal decomposition)
L degrees) are shown in Table 1 below.

Furthermore, the mechanical properties (tensile strength and elongation) and electrical properties (dielectric constant, dielectric loss tangent, volume resistivity, and dielectric breakdown voltage) of the aromatic polyimide obtained as described above were measured. Measurements of tensile strength and elongation are made at length 2
A test piece with a size of 0 mm x width 2 + 11111 x thickness 10 μm was prepared, and this test piece was used in a normal tensile tester at a tensile rate of 51/min. In addition, measurements of dielectric constant, dielectric loss tangent, and volume resistivity were performed according to JIS C-6481, and measurements of dielectric breakdown voltage were performed according to J! SC-21
The procedure was carried out according to 10.

The results of these measurements were as follows.

Mechanical properties Tensile strength 11.0 Kg/mm” Elongation rate 15
% Electrical properties Dielectric constant 6 2.8 Dissipation tangent tan δ 0.005 Volume resistivity lXl0'Ω/cm Breakdown voltage
250 KV/mm Example 2 N-methyl-2-pyrrolidone (NMP) 22.0ml
3.3',4.4'-biphenyltetracarboxylic dianhydride2. Add OOg and 1.99 g of 1,4-di(4-aminophenoxy)benzene, add nitrogen atmosphere,
Polymerization was carried out by stirring at a reaction temperature of 0° C. for 5 hours to produce an aromatic polyamic acid.

Next, add NMP to this aromatic polyamic acid solution.
68. After dilution by adding OmA, acetic anhydride 13.59
g and 5.20 g of pyridine were added, and an imidization reaction was carried out at 50°C for 3 hours to produce an aromatic polyimide,
Furthermore, methanol was added to this solution to precipitate the produced aromatic polyimide, which was filtered to obtain aromatic polyimide powder.

The logarithmic viscosity of this aromatic polyimide powder was measured in the same manner as in Example 1.

In addition, the aromatic polyimide obtained as described above was
A homogeneous aromatic polyimide solution having a concentration of 14% by weight was prepared by dissolving it in MP at about 30°C.

Example 1 except that this aromatic polyimide solution was used.
A thin film made of aromatic polyimide was produced in the same manner as above.

Regarding this thin film, the solubility and thermal decomposition onset temperature were measured in the same manner as in Example 1.

The results of these measurements (logarithmic viscosity, solubility, and thermal decomposition initiation temperature) are shown in Table 1 below.

Example 3 N-methyl-2-pyrrolidone (NMP) 24.0ml
2,3.3′,4°-biphenyltetracarboxylic dianhydride. OOg and 1.3-di(4-aminophenoxy)benzene2. OOg was added and stirred for 5 hours at a polymerization reaction temperature of 180°C in a nitrogen atmosphere to perform polymerization and imidization in one step, and the rotational viscosity (25°C) was 110.
A poise aromatic polyimide solution was obtained.

The aromatic polyimide contained therein was recovered from this aromatic polyimide solution, and the logarithmic viscosity of the aromatic polyimide was measured in the same manner as in Example 1.

In addition to using the aromatic polyimide solution mentioned above,
A thin film made of aromatic polyimide was produced in the same manner as in Example 1.

Regarding this thin film, the solubility and thermal decomposition onset temperature were measured in the same manner as in Example 1.

The results of these measurements (logarithmic viscosity, solubility, and thermal decomposition initiation temperature) are shown in Table 1 below.

Comparative Examples 1 to 3 1.4-di(4-aminophenoxy)benzene 1.99
An aromatic polyimide powder was obtained in the same manner as in Example 2 except that g was replaced with the diamine shown in Table 1.

Example 2: Logarithmic viscosity of this aromatic polyimide powder
It was measured in the same manner.

Further, an NMP solution having an aromatic polyimide concentration of about 5% by weight was prepared using the aromatic polyimide powder obtained as described above. A thin film made of aromatic polyimide was produced in the same manner as in Example 2 except that this solution was used. Regarding this thin film, the solubility and thermal decomposition onset temperature were measured in the same manner as in Example 2.

The results of these measurements (logarithmic viscosity, solubility, and thermal decomposition onset temperature) are shown in Table 1 below.

Table 1 Note 1: BPDA; Biphenyltetracarboxylic dianhydride Note 2: A; 1,4-di(4-7minophenoxy)benzene B; t,3-di(4-aminophenoxy)benzene C
;4,4°-diaminodiphenyl ether D;3,4"
-Diaminodiphenyl ether E; 2,4-di7minotoluene [Effects of the invention] The aromatic polyimide of the present invention can be used, for example, in phenol-based solvents, amide-based solvents (pyrrolidone-based solvents, formamide-based solvents, acetamide-based solvents, etc.). The aromatic polyimide composition (faith) of the present invention, which has sufficient dissolution performance in organic polar solvents and is therefore composed of an aromatic polyimide and the above-mentioned solvent and has a relatively low viscosity, is easily prepared. be able to.

Therefore, the aromatic polyimide composition of the present invention is applied to the surfaces of various electrical or electronic components, and then dried and heat-treated at a relatively low temperature to form an excellent protective film (thickness: approximately 0.
．． (approximately 1 to 500 μm) can be easily formed.

Furthermore, since the aromatic polyimide of the present invention has extremely excellent heat resistance, it can be used in various products that could not be used conventionally, such as interlayer insulating films such as ICs and LSIs. It can be used as a mask for circuit formation, a protective film for thin film resistors, etc.

Furthermore, the aromatic polyimide of the present invention, like conventionally known aromatic polyimides, maintains excellent performance in terms of mechanical strength, electrical insulation, etc., and is useful for surface protection and interlayer insulation of various electrical or electronic materials. It can be suitably used as a membrane or the like.

Patent applicant: Ube Industries Co., Ltd. −.

Representative Patent Attorney Shu 1 Hatori ---i

Claims (2)

[Claims] (1) An aromatic tetracarboxylic acid component whose main component is biphenyltetracarboxylic acids, and an aromatic diamine whose main component is di(aminophenoxy)benzene represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ A soluble aromatic polyimide obtained by polymerization and imidization from the components. (2) An aromatic tetracarboxylic acid component whose main component is biphenyltetracarboxylic acids, and an aromatic diamine whose main component is di(aminophenoxy)benzene represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ An aromatic polyimide composition in which a soluble aromatic polyimide obtained by polymerization and imidization is uniformly dissolved in an organic polar solvent.