JP2785394B2 - Thermoplastic aromatic polyimide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a thermoplastic aromatic material which can be molded at 430 ° C. or lower and can produce a molded article having excellent mechanical strength. It relates to polyimide.

[Description of Prior Art]

High-molecular-weight aromatic polyimides have excellent mechanical strength, and also have excellent properties such as heat resistance and electrical insulation. Polyimide film such as alignment film, protective film of electrical insulation (insulation film for solid-state devices, passivation film, interlayer insulation film for semiconductor integrated circuits, etc.)
It is used as a material for forming such as.

Aromatic polyimide having the above excellent properties is generally difficult to uniformly dissolve in an organic solvent, and is also difficult to melt, so that it was extremely difficult to easily obtain those molded products. .

Recently, various thermoplastic aromatic polyimides having a relatively low molecular weight and melting at an appropriate temperature have been proposed.

For example, as an aromatic polyimide with improved melt moldability, an aromatic polyimide which has been introduced with an arylene ether sulfone bond and is end-sealed with phthalic acid or the like,
JP-A-60-166326, JP-A-61-143478 or JP-A-61-143478
It is proposed in 62-43419. However, those known aromatic polyimides still have a problem in the stability of the polymer in the molding process.

Further, as a thermoplastic aromatic polyimide, for example, JP-A-1-131239, JP-A-1-110530, etc., using biphenyltetracarboxylic acids as an aromatic tetracarboxylic acid component, the following general formula And a thermoplastic aromatic polyimide having improved stability and fluidity obtained by reacting with a specific aromatic diamine component represented by the formula (1) and an end-capping agent such as dicarboxylic acid.

(However, Y ₁ , Y ₂ , Y ₃ and Y ₄ are substituents such as hydrogen and an alkyl group. X is a divalent group such as —O— and —SO ₂ —.) The aromatic polyimide represented by the general formula II has an extremely low secondary transition temperature (Tg) and remarkably deteriorates heat resistance. Therefore, the aromatic polyimide is fatal as a heat-resistant polymer and is not suitable.

(Problems to be Solved) The present invention relates to a biphenyltetracarboxylic acid, an aromatic diamine component, and an aromatic polyimide having thermoplasticity obtained by reacting a terminal blocking agent such as dicarboxylic acid. Another object of the present invention is to provide a thermoplastic aromatic polyimide which has appropriate heat resistance and is thermally and chemically stable.

[Means to solve the problem]

The invention uses the formula (Where n is the degree of polymerization, and R is 100-80 mol% of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride residue or 2,3,3', 4'- Residues of a mixture of biphenyltetracarboxylic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride; 20-0 mol% of pyromellitic dianhydride residues; Or
3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride residue, Y is 100-80 mol%, And 20-0 mol% is bis [4- (3-aminophenoxy)
Phenyl] sulfone, phenylenediamine, bis (aminophenyl) methane, diaminodiphenyl ether, bis (aminophenyl) benzene, or an aromatic diamine which is o-tolidine; It is. ) And the reduced viscosity (N-methyl-2-pyrrolidone, 30
0.5g / dl) is 0.25-1.0, and the glass transition temperature (Tg) is
The present invention relates to a thermoplastic aromatic polyimide having good hot press moldability at 270 to 300 ° C.

The thermoplastic aromatic polyimide of the present invention is preferably
It is produced by the following various methods using bis [(4-aminophenoxy) phenyl] sulfone represented by the following general formula I.

General formula I That is, the above-mentioned production method includes: (1) an aromatic tetracarboxylic acid component containing preferably 80 mol% or more of biphenyltetracarboxylic dianhydride; Phenoxy) phenyl] sulfones, preferably 80 mol%
The aromatic diamine component and the aromatic dicarboxylic anhydride component contained above are heated to a high temperature (preferably about 100 to 300 ° C., particularly preferably 140 to 250 ° C.) in an organic polar solvent to form one step. (2) polymerizing the above three components in an organic polar solvent, preferably at a temperature of about 80 ° C. or lower, particularly at a temperature of 0 to 60 ° C. to obtain an aromatic polyamic acid (aromatic) (3) preparing a tetracarboxylic acid component and an aromatic diamine component in excess of the aromatic diamine component, To produce an aromatic polyimide by polymerization and imidization, and then reacting the aromatic polyimide with an aromatic-o-dicarboxylic acid component.

In each of these production methods, it is preferable that the amount of the aromatic diamine component used is larger than the amount of the aromatic tetracarboxylic acid component used.

The aromatic polyimide of the present invention is a polymer having a high molecular weight and a concentration of 0.5 g / dl in a solution of a solvent (N-methyl-2-pyrrolidone). Degree), but preferably 0.25 to 1.0, preferably 0.30 to 0.70.

The aromatic tetracarboxylic acid component used in the production of the thermoplastic aromatic polyimide of the present invention,
2,3,3 ', 4'-biphenyltetracarboxylic acid or dianhydride, or further biphenyltetracarboxylic acids in combination with 3,3', 4,4'-biphenyltetracarboxylic acid or dianhydride Is preferably used in a proportion of at least 80 mol%, particularly at least 90 mol%, based on the total amount of all the tetracarboxylic acids used.

As the biphenyltetracarboxylic acids, 3,
3 ', 4,4'-biphenyltetracarboxylic acid or its dianhydride (3,3', 4,4'-isomer), 2,3,3 ', 4'-biphenyltetracarboxylic acid or its acid dianhydride Anhydrides (2,3,3 ',
4′-form) and the like. In particular, each of the above-mentioned biphenyltetracarboxylic dianhydrides, or 2,3,
A mixture of a 3 ', 4'-form dianhydride and a 3,3', 4,4'-form dianhydride can be preferably used.

The aromatic tetracarboxylic acid component is, for example, 3,
The use of "other aromatic tetracarboxylic acids" such as 3 ', 4,4'-benzophenonetetracarboxylic acid or its dianhydride, pyromellitic acid or its dianhydride in a small proportion (total tetracarboxylic acid) (The use ratio is less than 20 mol%, particularly less than 10 mol%, based on the use amount), and may be used together with the above-mentioned main component biphenyltetracarboxylic acids.

The aromatic diamine component used in the production of the thermoplastic aromatic polyimide of the present invention is a bis [(4-aminophenoxy) phenyl] sulfone represented by the aforementioned general formula I, wherein all aromatic diamines are used. It is preferably used in a proportion of at least 80 mol%, especially at least 90 mol, based on the total amount of the compound.

Examples of the bis [(4-aminophenoxy) phenyl] sulfone represented by the general formula I include bis [4- (4-aminophenoxy) phenyl] sulfone,
Bis [3- (4-aminophenoxy) phenyl] sulfone and the like can be mentioned, and particularly, bis [4- (4
-Aminophenoxy) phenyl] sulfone is most preferred.

In addition, as the aromatic diamine component, at least one of the hydrogens of the benzene ring of the bis [(4-aminophenoxy) phenyl] sulfone represented by the above general formula I has a suitable substituent (for example, methyl group). , A lower alkyl group such as an ethyl group and a propyl group, an alkoxy group such as a methoxy group and an ethoxy group, and a substituent such as a halogen atom such as chlorine and bromine).

As the aromatic diamine component, for example, bis [4-
(3-aminophenoxy) phenyl] sulfones, phenylenediamines, bis (aminophenyl) methanes,
The use of "other aromatic diamine compounds" such as diaminodiphenyl ethers, bis (aminophenyl) sulfones, bis (aminophenoxy) benzenes, and o-tolidines in a small proportion (based on the total amount of aromatic diamines used) (Less than 20 mol%, especially less than 10 mol%) can be used in combination with the bis [(4-aminophenoxy) phenyl] sulfone represented by the above general formula I.

Examples of the aromatic-o-dicarboxylic acid component include phthalic anhydride.

Examples of the organic polar solvent used in the polymerization include, for example, dimethyl sulfoxide, sulfoxide-based solvents such as diethyl sulfoxide, N, N-dimethylformamide,
Amide solvents such as N, N-dimethylacetamide, N-
Methyl 2-pyrrolidone, pyrrolidone solvents such as N-vinyl-2-pyrrolidone, sulfolane, γ-butyrolactone, etc., or phenol, o-, m-, or p-cresol, xylenol, halogenated phenol (parachlorophenol, Phenol solvents such as orthochlorophenol and parabromophenol) and catechol.

The thermoplastic aromatic polyimide of the present invention can be obtained by polymerizing and imidizing the reaction components in one step in an organic polar solvent as described above, but in order to stabilize the produced polyimide during molding processing. Before the imidization after the polymerization or again after the imidation after the polymerization,
It can be reacted with an o-dicarboxylic acid component.

The amount of the aromatic-o-dicarboxylic acid component used first when the thermoplastic aromatic polyimide of the present invention is produced, per 100 mol of the aromatic diamine component, is 0.5 to 30 mol of the aromatic dicarboxylic acid component, particularly Preferably, the ratio is about 1 to 20 mol.

As described above, after the polymerization, the aromatic-o-dicarboxylic acid component used when reacting with the obtained polymer again,
Per 100 moles of aromatic diamine component used initially, 2
It is preferable that the usage ratio is from 100 to 100 mol, particularly preferably from 5 to 50 mol.

Aromatic polyimide produced by the above-mentioned manufacturing method,
By injecting the polymer solution after polymerization and imidization into a poor solvent for the polymer such as alcohol or water, the polymer can be isolated as a precipitate and obtained as a powder.

If the reduced viscosity of the aromatic polyimide of the present invention is less than 0.25, the molecular weight of the polymer is small, a molded article having mechanical strength cannot be formed, and the reduced viscosity is 1.0.
Exceeding the above limits the molecular weight of the polymer to be too large to perform molding at temperatures below 430 ° C.

The molding temperature of the aromatic polyimide of the present invention is 430
C. or lower, particularly a temperature range of 400 to 300.degree. C. is preferred.

〔Example〕

Hereinafter, examples of the present invention will be described, and the present invention will be described in more detail.

(Test method) Tensile elastic modulus: Measured at 10 Hz using a “Mechanical spectrometer: RMS-605” manufactured by Rheometrics.
Was measured.

Tg; PerkinElmer's `` Differential Scanning Calorimeter: DSC-2
C type] in nitrogen at a heating rate of 20 ° C./min.

Thermal decomposition temperature: 20 ° C in the air by “Sequential thermal / thermogravimetric measuring device: SSC-560GH” manufactured by Seiko Denshi Kogyo Co., Ltd.
The temperature was measured at a heating rate of ° C./min., And the temperature was shown as the temperature at the intersection of the baseline and the maximum slope line at the beginning of weight loss in the measurement chart.

Measurement of hot pressability: A thermoplastic aromatic polyimide powder (sample) was hot-pressed at 300 to 360 ° C. for 6 minutes to form a sheet (size: about 6 cm × 4 cm × 20 μm).

The heat pressability is indicated by the following symbols, respectively, and their meanings are as follows.

 ：: A uniform and tough transparent sheet was obtained.

Δ: A uniform and transparent sheet was obtained, but the sheet was broken by several bends.

X: Only a non-uniform and opaque plate-like sheet or an extremely brittle plate-like sheet was obtained.

Evaluation of thermal stability: A thermoplastic aromatic polyimide powder (sample) was hot-pressed at 400 ° C. for 20 minutes to form a sheet (first hot-pressed body), and the first hot-pressed body was Cut into strips, rearrange them appropriately, and again at 400 ° C for 2 hours.
Hot pressed for 0 minutes and sheet (2nd hot pressed molded body)
Was formed, and a sheet (fourth hot press molded body) was formed sequentially and repeatedly.

From the first and fourth hot press moldings described above, 0.2.
1 g of the strip was cut out, and the strip was added to 20 ml of N-methyl-2-pyrrolidone (NMP) and dissolved by heating at 80 to 90 ° C. for 30 minutes, and the insoluble matter in the solution was filtered while hot. And washed sequentially with NMP and acetone, then dried in vacuo, and the weight of the insoluble material was measured.

Example 1 (Reference), Examples 2-3 and Comparative Examples 1-7 N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone) was used as a solvent in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, a reflux condenser, and a stirrer. NMP) 150 ml and toluene for azeotropic dehydration 20 ml were added, and (a) aromatic tetracarboxylic acid component: 3,3'4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and / or
Or 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (a-BPDA); (b) an aromatic diamine component; bis [4- (4-aminophenoxy) phenyl] sulfone (4-BAPS) Or bis [4- (3-aminophenoxy) phenyl] sulfone,
And (c) an aromatic diamine acid component; adding phthalic anhydride (PA) in the amounts shown in Table 1 while blowing in nitrogen gas and stirring to distill off the generated water; 175
Polymerization was carried out at a reaction temperature of about 180 ° C. for 8 hours to produce uniform polymer solutions.

This polymer solution was poured into methanol to precipitate a polymer, an aromatic polyimide powder was recovered, and the aromatic polyimide powder was washed three times with hot methanol and then dried.

Physical properties of each aromatic polyimide obtained as described above (reduced viscosity, second order transition temperature Tg, hot pressability, elastic modulus)
Are shown in Table 2, respectively.

Example 4 (Reference) In the same reaction vessel as used in Example 1, NM of the solvent was added.
P3600 ml and 200 ml of toluene for azeotropic dehydration were added, and 285 mmol and 285 mmol of s-BPDA and a-BPDA, and 600 mmol of 4-BAPS and 60 mmol of phthalic anhydride (PA) were added. Polymerization reaction was carried out in the same manner as in Example 1 to produce an aromatic polyimide powder.

Table 3 shows the physical property values (reduced viscosity, secondary transition temperature Tg, thermal stability in hot pressing) of the aromatic polyimide powder produced as described above.

Example 5 The same reaction vessel as used in Example 1 was replaced with Example 4
149 g of the aromatic polyimide powder obtained in the above, 15.2 g of phthalic anhydride (PA), 1000 ml of solvent NMP, and toluene
80 ml was added, and the mixture was reacted at a reaction temperature of 175 to 180 ° C. for 5 hours while stirring and removing generated water to produce a modified aromatic polyimide.
In the same manner as described above, 141 g of an aromatic polyimide powder was recovered.

Table 3 shows the physical property values (reduced viscosity, secondary transition temperature Tg, thermal stability in hot pressing) of the aromatic polyimide powder obtained as described above.

Table 3 also shows the physical properties of the aromatic polyimide powders obtained in Example 1 and Comparative Example 7.

[Function and effect of the present invention] The thermoplastic aromatic polyimide of the present invention has a high degree of heat resistance while having a secondary transition temperature Tg in the range of 270 to 300 ° C, and has good moldability by hot pressing. Is excellent and the thermal stability by repeated hot pressing is excellent, and it is a thermoplastic aromatic polyimide having extremely excellent moldability and heat resistance.

Continuation of the front page (56) References JP-A-62-98327 (JP, A) JP-A-61-241358 (JP, A) JP-A-61-141731 (JP, A) JP-A-51-2798 (JP) JP-A-58-157190 (JP, A) JP-A-59-170122 (JP, A) JP-A-1-110530 (JP, A) JP-A-1-215825 (JP, A) 1-222128 (JP, A) Japanese Patent Publication No. 45-9393 (JP, B1) European publication 324288 (EP, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 73/10 CAS (STN ) REGISTRY (STN)

Claims (1)

(57) [Claims] (1) Expression (Where n is the degree of polymerization, and R is 100-80 mol% of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride residue or 2,3,3', 4'- Residues of a mixture of biphenyltetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, wherein 20-0 mol% is a pyromellitic dianhydride residue, Or
3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride residue, Y is 100-80 mol%, And 20-0 mol% is bis [4- (3-aminophenoxy)
Phenyl] sulfone, phenylenediamine, bis (aminophenyl) methane, diaminodiphenyl ether, bis (aminophenyl) benzene, or an aromatic diamine which is o-tolidine; It is. ) And the reduced viscosity (N-methyl-2-pyrrolidone, 30
0.5g / dl) is 0.25-1.0, and the glass transition temperature (Tg) is
Thermoplastic aromatic polyimide having good hot press moldability at 270-300 ° C.