JPS59223726A - Chemical ring closure of polyamic acid - Google Patents

Abstract

PURPOSE:To effect the chemical ring closure of a polyamic acid at a good degree of imidation with a prolonged gelation time in spite of its being a two- component system, by reacting an organic solvent solution of a polyamic acid in the presence of an imidazole and a carboxylic acid monoanhydride. CONSTITUTION:A polyamic acid obtained by reacting a diamine with a tetracarboxylic acid dianhydride is chemically ring-closed into an imide by reacting an organic solvent solution of the polyamic aicd at 170 deg.C or below in the presence of a carboxylic acid monoanhydride and an imidazoles of formula I (wherein R<1>, R<2>, and R<3> are each H, an aliphatic group, an aromatic group, cycloalkyl, or aralkyl), formula II (wherein R<4> is H, an aliphatic group, cycloalkyl or aralkyl, and R<5>, R<6>, R<7>, and R<8> are each H, a halogen atom, an aliphatic group, an aromatic group, cycloalkyl, or aralkyl, or/and formula III (wherein R<9>, R<10>, R<11>, R<12>, R<13>, R<14>, and R<15> are each H, an aliphatic group, an aromatic group, cycloalkyl, or aralkyl, R<16> is alkylene, alkylidene or phenylene, and X is a halogen atom, cyano, nitro, or acetyl).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new process for ring-closing polyamic acids with polyimides. Thermal ring-closing method and chemical ring-closing method are known as methods for producing polyimide by ring-closing polyamic acid, but in general, in the thermal ring-closing method, the imidization reaction is slow unless the polyamic acid is greater than /gO'Q. The imidization of and the hydrolysis of polyamic acid are concerted reactions,
Therefore, the mechanical properties of chikupolyimide films prepared by the thermal ring-closing method are extremely poor.

On the other hand, in the chemical ring closure method, the reaction is carried out at iqo'6 or less, so
Since the hydrolysis reaction of polyamic acid progresses slowly, there is little decrease in the degree of polymerization of the produced polyimide.Therefore, polyimide films made by the chemical ring closure method have good mechanical properties but contain a large amount of tertiary amine compounds. The amount of carboxylic acid anhydride is required to be equal to or more than the amide bond of the polylamide acid. Among the tertiary amine compounds, isoquinoline and pyridine are effective when used in a relatively small amount, but the amount used is required to be 1 mole or more per amic acid bond of the polyamic acid.

Moreover, in such chemical ring closure, carboxylic acid anhydride and tertiary amine are added to polyamic acid solution, and IO
It has the disadvantage that it completely gels when mixed for minutes. Therefore, the present inventors conducted intensive studies to find a chemical ring-closing agent with a long gelation time, and found that a two-component system consisting of an acid anhydride and an imidazole was able to significantly extend the gelation time. - We have discovered a chemical raw material that can be imidized in the same way as a tertiary amine type, and have thus arrived at the present invention.

That is, the gist of the present invention is to convert an organic solution of a polyamic acid obtained by the reaction of a diamine and a tetracarboxylic acid dihydride into a solution of the general formula [I], [■] or / or [open] H+ (in the formula, R1, R2 and R8 are hydrogen atoms, aliphatic groups,
Aromatic group 1. It may be substituted with a cycloalkyl group or an aral or alkoxy group. ) (wherein, R4 represents a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, or an aralkyl group, and R11, R6, R7, and R♂
represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, or an aralkyl group. However, one or more hydrogen atoms of the cycloalkyl group and the aralkyl group may be substituted with a halogen atom or an alkoxy group. ) 11 (wherein, R11, RIO, R11, RI2, R13, R
I4 and R1 represent a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group or an aralkyl group. However, one or more hydrogen atoms of the cycloalkyl group and the aralkyl group may be substituted with a halogen atom or an alkoxy group. Reacts with the imidazole region represented by R1"(t'i represents an alkylene, alkylidene, or phenylene group; The invention consists in a method of chemically ring-closing polyamic acid and imidizing it.

To explain the present invention in more detail, as the diamine used to produce the polyamic acid used in the present invention, aromatic diamines, aliphatic diamines, and heterocyclic diamines can be used. However, specific examples include metaphenylenediamine, paraphenylenediamine, g,p'-diaminodiphenylpropane,
p4'-diaminodiphenylmethane, benzidine,
Nail-diaminodiphenylsulfide, G, q'-diaminodiphenylsulfone, J, 3'-diaminodiphenylsulfone, p, p'-diaminodiphenyl ether,
Co, 6-diamitupyridine, bis-(ter-aminophenyl) diethylsilane, bis-(ter-aminophenyl) phosphine oxide, bis-(qua-aminophenyl)-
N-methylamine, 1. S-diaminonaphthalene, 3.
．． 3'-dimethyl-benzidine 1. ? , 3'-dimethoxy-benzene, 2. 'I-bis(β-amino-t-
methyl)toluene, bis-(hala-β-amino-t-methylphenyl)ether, para-bis(comethyl-guaminobenzyl)benzene, para-bis(/,/-dimethyl-3-aminopentyl)benzene, m-xylylene diamine, p-xylylene diamine, bis(para-amino-cyclohexyl)methane, hexamethylene diamine, heptamethylene diamine, octamethylene diamine,
Nonamethylene diamine, decamethylene diamine, 3-methyl-heptamethylene diamine, 1.4('-dimethylheptamethylene diamine, 4.//-diaminododecane, 1.2-bis-(3-aminopropoxy)-ethane ,
λ, 2-dimethylpropylenediamine, 3-methoxy-
Hexamethylene diamine, 2. A;-dimethylhexamethylenediamine, co,S-dimethylhexamethylenediamine, S-methylnonamethylenediamine, /,tI-diamino-cyclohexane, /,/2-diaminooctadecane, 2. ! ; Diaminor/, 3. 'I-oxadiazole and the like may be mentioned, and these may be used alone or as a mixture. Among these, particularly preferred are da, da'-diaminodiphenyl ether and 3,3'-dimethyl-benzidine and mixtures thereof.

In addition, as the tetracarboxylic dianhydride used for producing the polyamic acid used in the present invention, aromatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, and heterocyclic tetracarboxylic acid It is also possible to use anhydrides, specific examples of which include pyromellitic anhydride, 2,3. b, 7-naphthalene tetracarboxylic dianhydride, 3.3', 'I, 'I'-
diphenyltetracarboxylic dianhydride, /2. ! ;,
b-naphthalene tetracarboxylic dianhydride, 2.2
'.

3.3'-diphenyltetracarboxylic dianhydride,
Nibis(3,lI-dicarboxyphenyl)propanihydride, bis(,y,q-dicarboxyphenyl)sulfone dianhydride, 3. q, 9. lθ-helentitracarboxylic dianhydride, bis(3,4L-dicarboxyphenyl)ether dianhydride, ethylenetetracarboxylic dianhydride, naphthalene-il, 2. tt, s-tetracarboxylic dianhydride, naphthalene/, 39g-tetracarboxylic dianhydride, bis(3,xi-dicarboxyphenyl)ketone dianhydride, decahydronaphthalene/,
tI, 3. di-tetracarboxylic dianhydride, di-dimethyl-/.

Ko,,3. ! rJ,, 1-hexahydronaphthalene-/
,Ko,! i.

6-tetracarboxylic dianhydride, co,6-dichloronaphthalene-/, 1I, 3. g-tetracarboxylic dianhydride, :127-dichloronaphthalene-/,'I,A;,I
t-tetracarboxylic dianhydride, 2,3. /,, Cutetrachlornaphthalin-/, Gu,! r, g-tetracarboxylic dianhydride, phenanthrene-/, g, 9. / 0
-Tetracarboxylic dianhydride, cyclopentane-/:
l, 3. 'l-tetracarboxylic dianhydride, pyrrolidine-λ, 3. da, left-tetracarboxylic dianhydride, pyrazine, 2. ,? jj-tetracarboxylic dianhydride, co, corbis(2,3-dicarboxyphenyl) fropannianhydride, l, /-bis(S, 3-dicarboxyphenyl)
Ethani dianhydride, /, /-bis(34-dicarboxyphenyl)ethani dianhydride, bis(,2,3-dicarboxyphenyl)methani dianhydride, bis(3,q-dicarboxyphenyl)methani dianhydride, benzene -/, a, 3
．． tt-tetracarboxylic dianhydride, /, 2,3. '
I tartan tetracarboxylic dianhydride, thiophene-2
, 3, JS-tetracarboxylic dianhydride, etc., and these can be used alone or as a mixture.

Among these, pyromellitic anhydride 1. ? , J',
Particularly preferred are 4t, I'-diphenyltetracarboxylic dianhydride, bis(3,tZ-dicarboxyphenyl)ketone dianhydride, and mixtures of two or three thereof.

The organic solvent used to prepare the organic solvent solution of polyamic acid is the organic solvent used to synthesize polyamic acid, and its functional group does not react with either the reactant diamine or the tetracarboxylic dianhydride. It's like not doing it. The organic solvent of the octopus must not react with polyamic acid and must dissolve polyamic acid.

Such solvents include) JjJ-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylmethoxyacetamide, N-methyl glolactam, dimethyl sulfoxide, N-metelukopyrrolidone, tetramethylurea,
Examples include, but are not limited to, tetramethylthiourea, pyridine, dimethylsulfone, hexamethylphosphoramide, tetramethylenesulfone, formamide, N-methylformamide, butyrolactone, and N-acetyl-copyrrolidone. Among these, N is selected from the viewpoint of ease of evaporation and ease of diffusion of the solvent when producing a polyimide film from a polyamic acid solution.

Particularly preferred are N-dimethylformamide and N,N-dimethylacetamide. The solvent can be used alone, or in combination with other solvents or with poor solvents such as benzene, benzonitrile, dioxane, xylene, toluene and cyclohexane. In this case, the concentration of polyamic acid in the organic solvent solution of polyamic acid is /~30% by weight, preferably 3~-0% by weight.

General formula [I], CIO
or/and CI) and the carboxylic acid r anhydride are added and stirred at 70C.
The reaction is preferably carried out in the following manner: 11J/Io'C~/LOT:: The polyamic acid is diimidized by chemical ring closure.

When it exceeds /70C, the molecular weight decreases and mechanical properties deteriorate. As the imidazole compound, general formula [I],
/ of the compounds represented by C1f] and [l)
Use 4f1 or higher.

Examples of aliphatic groups and aromatic groups include alkyl groups, hydroxyalkyl groups, cyanoalkyl groups, and aryl groups. Of course, these groups, like cycloalkyl groups and aralkyl groups, may have seven or more of their hydrogen atoms substituted with halogen atoms or (gel alkoxy groups). Representative examples include HlN-thia/ethyl- a-conityldermethylimidazole, N-cyanoethyl λ-methylimidazole, N-cyanoethyl-12-phenylimidazole, cophenyl-4(-methyl-5-hydroxymethylimidazole, Cohn uniluta. Left-dihydroxymethylimidazole, imidazole, Cophenyl-4(-methyl-5-hydroxymethylimidazole) Methyl imidazole, Coether-goomethylimidazole, Dermeter imidazole, Coundecyl imidazole, 2-
Phenyludamethylimidazole, N-methylimidazole, cophenylimidazole, termethylimidazole, N-phenylimidazole, copenzylimidazole, N-benzylimidazole, N-benzyl,
2-methylimidazole, benzimidazole, +j,
6. ? -tetrachlorobenzimidazole, S-methylbenzimidazole, comethylpenzimidazole,
Examples include, but are not necessarily limited to, 6-benzylbenzimidazole. Further, these imidazoles may be used in combination.

The amount of such imidazole used is 0.07 mol or more, preferably 0.1 mol or more per 1 mol of amide bond of the polyamic acid. As the carboxylic acid anhydride, any of aliphatic carboxylic acid anhydrides, aromatic carboxylic acid anhydrides, alicyclic carboxylic acid anhydrides, and heterocyclic carboxylic acid anhydrides can be used, and specific examples thereof include: Examples include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, formic acid anhydride, malonic anhydride,
Succinic anhydride, maleic anhydride, phthalic anhydride, benzoic anhydride, 0゜m and P-) ruyl anhydride, m and p-ethylbenzoic anhydride, p -n-
Propylbenzoic anhydride, p-isopropylbenzoic anhydride, anilic anhydride, o, m and p-nitrobenzoic anhydride, o, m and p-chlorobenzoic anhydride, various dibromo and dichlorobenzoic acids anhydride, tribromo and trichlorobenzoic anhydride, hemeritic anhydride, 3. 'I-xylylic anhydride, isoxylylic anhydride, mesitylenic anhydride, veratrum acid anhydride,
Trimethoxybenzoic anhydride, α and β-naphthoic anhydride, p-phenylbenzoic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, anhydride Examples include, but are not limited to, chlorendic acid, nicotinic anhydride, innicotinic anhydride, picolinic anhydride, quinolinic anhydride, and the like.

The amount of such carboxylic acid-anhydride used is 115 mol or more, preferably 1 mol or more per 1 mol of amide bond of the polyamic acid.

In addition, when creating a polyimide film, add imidazoles represented by the general formula [I], [I [)] and [amount] to the polyamic acid solution, stir and mix, and then apply the glass using a Gardner doctor knife. A thin film was formed on the plate and dried in a hot air drying oven at /20C for 10 minutes to effect chemical ring closure.

Next, this semi-dry film is fixed on a metal frame, and further /20υ υ, 2s o C'! The temperature was raised in 15 minutes, and finally 3! ; A polyimide film of OtTT/θμ was obtained by heat treatment for 4' minutes. This polyimide film has excellent mechanical properties, heat resistance, thermal decomposition onset temperature, electrical properties, dimensional stability, and is transparent.

In the examples, the ηinh of the polyamic acid was measured at 1.30C after adjusting the polyamic acid to an N-methyl λ-pyrrolidone o,sy/dt solution.

In addition, the imidization rate was determined using infrared absorption spectroscopy.
Absorption of imide group of cm-' or /'110t"m
Using the imide group absorption of −1, the amount of light absorption A due to imide was calculated, and was defined as the percentage of the light absorption amount of the imide group absorption of a thin film with an imidization rate of 100, which was determined elsewhere.

Moreover, the gelation time indicates the time until the viscosity reaches 1000 voids as measured by a B-type viscometer (20C).

Examples are shown below.

Example-/Pyromellitic anhydride (hereinafter abbreviated as PMDA)? '1.
! ;! ;'13 F (0,3!; left b root )
, ri, ri'-diaminocyphenylethe #3s, tt
tgs y (0,/?b qmot), 3.3
'-dimethylbenzidine37. ! ;, 337f (0,
/ ? l,,r mol), p'l'-N,
Polyamic acid solution (polymer concentration CP) prepared from N-dime f k e, TI/muamide (hereinafter abbreviated as DMF)/+3tcc = / 0. Owt%) 2o, o t
f (amic acid unit, 1III X / 0-3m
ole equivalent) Bikani weighing, i.

At this point, the ηinh value of polyamic acid is 1gd17
It was f.

Separately, 31(,2,
g322 X/Omot), DMF//, 6cc
First weigh the DMF solution, then add it to the polyamic acid solution and mix uniformly, and then add acetic anhydride to the solution. (7g, glfgo x 10 mot) was added. (At this point, (P) = l,, Owt%, P
MDA (mob) / acetic anhydride (mol) / -27-
1-= uimitazole (moz) = /, o /
q, o/o, otsu. ) For 9.2 minutes, acetic anhydride was thoroughly stirred and mixed with polyamic acid, and using this polyamic acid solution, a 75 μ film was cast on a 7-layer plate using a Gardner doctor knife. )/20C for 10 minutes in a hot air drying oven.

When the imidization rate was measured at R7, ), g'ly
Met.

On the other hand, using the remaining polyamic acid solution, the time until the polyamic acid solution became unable to be cast into a film (gelling time) was measured, and it was found to be 1 hour in aOC.

Next, this semi-dry film was fixed on a metal frame, and was further heated for 72 minutes at 10 °C for 3! ;Or: The final imidization rate after heat treatment in the chamber! A 10μ film of rj-chi was obtained.

Example-2, 3, Da, Left, 6, and 7 In place of cophenylimidazole, the following imidazole derivatives were added in an equal mate amount (2, g3 x 10
moz) in the same manner as in Example −/ except that /
Imidization was performed for 20C-/θ minutes, and the imidization rate and gelation time were measured. The results are shown in Table-7.

Table 7 Comparative Example - Inquinoline was added in place of cophenylimidazole in an equal mol amount (θ, J66F, 2.g JX/
Imidization was carried out for 70 minutes in the same manner as in Example 7, except that 0-"mol) was used, and the imidization rate and gelation time were measured.

As a result, the imidization rate is dθ and the gelation time is 20′c.
It took 70 minutes.

Patent applicant: Mitsubishi Kasei Kokyo Co., Ltd. Procedural amendment (voluntary) / Case indication: Showa Sza patent application No. 9g333!
Title of the invention Chemical ring closure method for polyamic acids 3 Amendment applicant Applicant (594) Mitsubishi Chemical Industries, Ltd. q Agent 〒io.

@ No. 2 S, 2-chome, Marunouchi, Chiyoda-ku, Tokyo Subject of amendment Column B of “Detailed Description of the Invention” of the specification Contents of amendment (1) “N-cyanoethyl- No ethyl goo methyl imitasol.

N-Cyanethyl! -Methylimidazole”.

On the same page, line 1S: [N-methylimidazole].

In lines 76 to 7 of the same page, "N-phenyl, hte 5[sai zole"] and in lines 1g to 1q of the same page, 1-N-benzylimidazole, N-pencylno-methylimidazole" were deleted. I have 1 extra.

that's all

Claims (1)

[Claims] (1) An organic solvent solution of a polyamic acid obtained by the reaction of a diamine and a tetracarboxylic dianhydride is prepared using the general formula [1], [11) or/and C11] 1 (wherein, R1, R2, and R3 represents a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, or an aralkyl group.The hydrogen atom of the cycloalkyl group and the aralkyl group may be substituted with a logone atom or an alkoxy group. )5 (wherein R' represents a hydrogen atom, an aliphatic group, an aromatic group, a cycloalkyl group, or an aralkyl group, R6, R6, R
? and R8 is a hydrogen atom, ), a rogen atom, an aliphatic group,
Indicates an aromatic group, a cycloalkyl group, or an aralkyl group. However, one or more hydrogen atoms of the cycloalkyl group and the aralkyl group may be substituted with a halogen atom or an alkoxy group. ) 11 (wherein, R11, RIOlRll, R12, Rls,,
RI4 Oyohi R15 is a hydrogen atom, an aliphatic group, an aromatic group,
Indicates a cycloalkyl group or an aralkyl group. However, one or more of the hydrogen atoms of the cycloalkyl radical or the aralkyl group may be substituted with a halogen atom or an alkoxy group. RIO represents an alkylene group, an alkylidene group or a phenylene group, and X represents a halogen atom, a cyano group, a nitro group or an acetyl group. ) in the presence of a carboxylic acid-anhydride at a temperature of /7θC or less to chemically close the polyamic acid and imidize it.