JPS63314240A - Novel polyimide copolymer and its production - Google Patents

Abstract

PURPOSE:To obtain the title copolymer excellent in dimensional stability, tensile properties, etc., by reacting an organic tetracarboxylic acid dianhydride successively with two organic diamine compounds and conducting the ring closure of the formed polyamic acid copolymer. CONSTITUTION:An organic tetracarboxylic acid dianhydride of formula I (wherein R0 is a tetravalent organic group) is reacted with 50-90mol.% organic diamine compound of formula II (wherein R1 is a bivalent organic group) in an organic polar solvent to produce a prepolymer having acid anhydride groups on both ends. this prepolymer is mixed with an organic diamine compound of formula III (wherein R2 is a bivalent organic group, provided that the case where R1 and R2 are formulas IV and V, respectively, and the case where they are formulas V and IV, respectively, are excluded) so that the total of the diamines of formulas II and III may be equimolar to the total of the compound of formula I, and the mixture is reacted. The obtained polyamic acid copolymer is subjected to ring closure to obtain a polyimide copolymer of formula VI (wherein m is a positive integer).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polyimide resin known as a heat-resistant resin. Specifically, the present invention relates to a novel polyimide copolymer that can yield a polyimide resin having extremely excellent thermal and hygroscopic dimensional stability and excellent tensile properties.

(Prior Art) It has been known that polyimide resins have high heat resistance, chemical resistance, electrical properties, mechanical properties, and other excellent properties. 10999
Polyimide membranes obtained using polyamic acid obtained from 4゜4'-diaminodiphenyl ether and pyromellitic dianhydride, as shown in Although it is excellent in
Generally, it is known that the linear expansion coefficient and humidity expansion coefficient are large, and the dimensional stability is poor. That is, this polyimide resin has a linear expansion coefficient of about 3 x 10"5"C-1, and has poor thermal dimensional stability, and has problems such as warping and curling when laminated with metal etc. Furthermore, the coefficient of humidity expansion is as large as 2.5 x 10''/%RH, which has the problem of warping and curling after processing, for example, FPC (flexible printed circuit board).

To solve this problem, a polyimide film obtained using polyamic acid obtained from dimethylbenzidine and pyromellitic dianhydride has a small linear expansion coefficient and a low humidity expansion coefficient, but has excellent dimensional stability. It has the disadvantage that it is brittle, lacks practicality as a film, and cannot actually be used industrially.

However, in recent years, there has been an increasing demand for polyimide resins that have better dimensional stability and excellent mechanical properties such as elongation, and various studies are being conducted for this purpose. For example, in JP-A-61-158025, p-
We are attempting to improve the thermal dimensional stability by copolymerizing phenylenediamine with apricot, and at the same time improving mechanical properties such as elongation by copolymerizing with phenyltetracarboxylic acid.

However, since the biphenyltetracarboxylic acid component is used, the resulting polyimide resin has disadvantages such as thermal softening and loss of conventional excellent heat resistance.
Furthermore, a yield point occurs during a tensile test, and the stress strain resistance is large, causing problems such as deformation during use. Furthermore, the polyimide film obtained in this manner is insoluble in alkali, and its processability in post-treatment or post-processing steps such as alkali di-soching is extremely poor.

For example, as seen in JP-A-58-185624, a method has been proposed in which dimethylbenzine is introduced as a diamine component to improve thermal dimensional stability. It becomes weaker and more brittle.

Furthermore, for example, JP-A-61-264028, JP-A-61
-241325, JP-A-61-181828, etc., all disclose soft segments such as diaminodiphenylethyl, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, pyromellitic anhydride, paraphenylenediamine, Modification by copolymerization of hard segments such as dimethylbenzidine has been proposed.

However, in all cases, the above-mentioned dimensional stability during thermal and moisture absorption and mechanical strength such as elongation were not satisfied.

(Problems to be Solved by the Invention) The present invention maintains the excellent mechanical strength, heat resistance, and chemical resistance of polyimide resins that have been widely used, while improving the dimensional stability during thermal and moisture absorption. The purpose is to improve.

(Means for Solving the Problems) The present invention is based on the general formula [R1 and R2 are divalent organic groups, provided that R1 and R2 are -o- and -o-0-o-, respectively.

-@-0-@-, (except in the case of minister <, R.

is a tetravalent organic group 1m is a positive integer] A polyimide copolymer consisting of a repeating unit represented by the formula [wherein R is a tetravalent organic group] Anhydride (A) and 50 to 90 mol % of the organic diamine compound (B) represented by the general formula % formula % [wherein R1 is a divalent organic group] in an organic polar solvent. The reaction is carried out to obtain a prepolymer having acid anhydride groups at both ends, and then the general formula % formula % [wherein R2 is a divalent organic group, provided that R,, R2
(Except when Σ←, -@=, the organic diamine compound (C) represented by ko is the total organic diamine ffi [(B)
+ (C)] is added and reacted with the organic tetracarboxylic dianhydride (A) in substantially equimolar amounts, and the resulting polyamic acid copolymer is thermally or chemically dehydrated and ring-closed. This is a method for producing a polyimide copolymer.

This polyimide copolymer has reduced linear expansion coefficient and humidity expansion coefficient while maintaining various properties inherent to conventionally widely used polyimides, such as heat resistance and mechanical strength, and has improved dimensional stability.

To explain in detail the structure of this polyimide copolymer, the block unit [in the formula, R1 is a divalent organic group, and Ro is a repeating unit with one valent organic group E, in the formula, R2 is a divalent organic group, Ro is a tetravalent organic group] By adopting a structure connected by these, a regularly arranged structure is obtained. Therefore, in the polyimide resin obtained from this polyamic acid, repeating units [wherein R2 is a divalent organic group and RO is a tetravalent organic group] are extremely homogeneously dispersed, that is, hard segments or soft segments. is homogeneously dispersed at the molecular level, it is presumed that the dimensional stability and elongation of the resulting polyimide resin are simultaneously significantly improved. The number of repetitions m in block units is 1 to 9
, preferably 1-7, more preferably 1-4. This is because if the repetition number m exceeds 9, the copolymerization ratio will be biased and the effect of copolymerization cannot be found. Also,
The molecular weight of this copolymer is not particularly restricted, but in order to maintain the strength of the polyimide resin produced,
Preferably there are 10 or more repeating units.

Next, to explain the manufacturing method of this polyimide copolymer, organic tetracarboxylic dianhydride (A) represented by the general formula % formula % [wherein Ro is a tetravalent organic group] 50 to 90 mol % of the organic diamine compound (B) represented by the general formula % formula % [wherein R1 is a divalent organic group] is reacted in an organic polar solvent, and acid anhydride is added at both ends. A prepolymer having a group is obtained, and then an organic diamine compound (C) represented by the general formula % formula % [wherein R2 is a divalent organic group] is added to the total diamine amount [(B)+ (C)] can be obtained by adding and reacting tetracarboxylic dianhydride (A) in substantially equimolar amounts.

For example, an organic tetracarboxylic dianhydride is suspended and dissolved in an organic polar solvent, and 50 to 90 mol%, preferably 50 to 87.5% of the organic tetracarboxylic dianhydride is added thereto.
mole%, more preferably 50 to 80 mole% of 4.4'-
Diaminodiphenyl ether is added and reacted to obtain a prepolymer solution containing acid anhydride groups at both ends. However, in the reaction for obtaining this prepolymer, the order of addition of the organic tetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether may be reversed. Then, the general formula [wherein X is a monovalent substituent,
A monovalent organic group such as a methyl group or a methoxy group or a hydrogen atom,
represents a halogen group, a nitro group, a carboxyl group, or a hydroxyl group, and 1m represents an integer of 1 to 3.] After adding an organic diamine compound represented by A polyamic acid solution containing 35% by weight, preferably 10 to 25% by weight is obtained. In order to allow the above polymerization reaction to proceed stably, it is preferably carried out in a substantially anhydrous system at a temperature of 60°C or less, preferably 30'C or less, more preferably 10'C or less, and more preferably 10 hours or less. It is desirable to complete the reaction within 5 hours, more preferably within 3 hours. Because J, Appl, Polymer,
Sc1. ．． 302883-2905 (1985
), the acid anhydride passes through the acid anhydride-terminated prepolymer during the reaction, and this acid anhydride may react with moisture in the system and become a dicarboxylic acid, inhibiting the growth of the polymer chain length. be.

Next, a method for obtaining the polyimide copolymer of the present invention from a solution of this precursor polyamic acid copolymer will be explained.

In the method of thermally dehydrating and ring-closing (imidization), a solution of the above-mentioned polyamic acid copolymer is cast or coated onto a drum or an endless belt to form a film, and the film is heated at 150°C.
Dry for about 30-90 minutes at the following temperature to obtain a self-supporting membrane. Next, this is peeled off from the support, the end portions are fixed, and then gradually heated to about 100 to 500°C, cooled and then removed to obtain a polyimide film made of the polyimide copolymer of the present invention.

In the method of chemically dehydrating and ring-closing (imidization), a stoichiometric or higher dehydrating agent and a catalytic amount of tertiary amines are added to a solution of the polyamic acid copolymer, and the mixture is cast or cast onto a drum or endless belt. Coat it to form a film, and apply the film to 15
Dry for about 5-30 minutes at a temperature below 0°C to obtain a self-supporting membrane. Next, this is peeled off from the support, the ends are fixed, and then gradually heated to about 100 to 500°C, cooled and then removed to obtain a polyimide film made of the polyimide copolymer of the present invention.

Next, to explain the raw materials used in the present invention, when obtaining the polyamic acid copolymer which is the precursor of the polyimide copolymer of the present invention, for example, pyromellitic dianhydride is used as aromatic tetracarboxylic dianhydride. Anhydride, 3.3'
, 4.4'-biphenyltetracarboxylic dianhydride, 3.3', 4゜4'-benzophenonetetracarboxylic dianhydride, naphthalene-1,2,5,6-tetracarboxylic dianhydride, etc. Dibasic acids can be mentioned.

In order to obtain the effects of the present invention, the aromatic diamine component is a combination of 4,4'-diaminodiphenyl ether and a diamine compound represented by the general formula [where X is the same as above]. Most desirable. The diamine compound represented by this general formula is, for example, 3,3'-dimethyl-4
, 4″-diaminobiphenyl, 3,3′-dimethoxy-
Examples include 4,4'-diaminobiphenyl, 4,4-diaminoparaterphenyl, etc., and the effects of the present invention can be sufficiently obtained even when these are used alone or as a mixture of two or more.

In addition, as an aromatic diamine component, the general formula, H2N-R-
Diamine compounds represented by NH2 [wherein R is a divalent organic group], such as 4.4'-bis(4-aminophenoxy)biphenyl, 4°4'-diaminodiphenylsulfone, 3.3'- Diaminodiphenylsulfone, bis[4-(4-aminophenoxy)phenylcosulfone, bis[4-(3-aminophenoxy)phenylcosulfone, bis[4-(2-aminophenoxy)phenylcosulfone, 1,4- Bis(4-aminophenoxy)benzene, 1.3-bis(4-aminophenoxy)benzene, 1.3-bis(3-aminophenoxy)benzene, 1.4-bis(4-aminophenyl)benzene, bis[ 4-(4-aminophenoxy)phenylconythyl, 4.4'-diaminodiphenylmethane,
Bis(3-ethyl-4-aminophenyl)methane, bis(3-methyl-4-aminophenyl)methane, bis(3
-chloro-4-aminophenyl)methane, 3.3' -
Diaminodiphenylsulfone, 4.4'-diaminodiphenylsulfone, 2.2', 5.5'-tetrachloro-4,4'-diaminobiphenyl, 4゜4'-diaminodiphenylsulfide, 3.3'-diaminodiphenyl ether , 3.4'-diaminodiphenyl ether, 4.4'-diaminodiphenylmethane, 4.4'
-diaminooctafluorobiphenyl, 2,4-diaminotoluene, metafuylenediamine, 2,2-bis[4-(4-aminophenoxy)phenyl]propane,
2゜2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2゜2-bis(3-hydroxy-4-aminophenyl)propane, 2,2-bis(3-hydroxy-4-aminophenyl)hexafluoropropane, 9゜9-bis(4-aminophenyl)-1
It is also possible to partially use polyvalent amine compounds such as 0-hydro-anthracene, orthotolidine sulfone, 3°3', 4.4'-biphenyltetraamine, and 3°3', 4.4'-tetraaminodiphenyl ether. .

Examples of the organic polar solvent used in the production reaction of the polyamic acid copolymer include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N
, N-dimethylformamide, N,N-diethylformamide, etc., N,N-dimethylacetamide, N,N-diethylacetamide, etc., acetamide solvents, N-methyl-2-pyrrolidone, N-vinyl-2 - pyrrolidone solvents such as pyrrolidone, phenolic solvents such as phenol, o+, m-, or p-cresol, xylenol, halogenated phenols, catechol, or hexamethylphosphoramide, γ
-butyrolactone, etc., and it is desirable to use these alone or as a mixture, but it is also possible to use aromatic hydrocarbons such as xylene and toluene.

In addition, this polyamic acid copolymer contains 5 to 40% by weight, preferably 10 to 30% by weight of each of the above in a polar solvent.
It is desirable from the viewpoint of handling that the melt weight is low.

Further, examples of the dehydrating agent for chemically dehydrating and ring-closing (imidizing) the polyamic acid copolymer include aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides, and the like. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and polycyclic tertiary amines such as pyridine, picoline, and isoquinoline.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

In the examples, elongation was measured in accordance with JIS K-7113. The coefficient of linear expansion was measured using a thermomechanical analyzer [TM
A-10, made by Seiko Electronics Co., Ltd., at 10℃/
It was measured under conditions of 200°C and expressed as a value of 200°C. The humidity expansion coefficient was measured using a thermomechanical analyzer [TMA-30, manufactured by Shimadzu Corporation]
The relative humidity was measured at a temperature of 50° C. while changing the relative humidity from 20 to 80%, and the relative humidity was expressed as an average value between 20 and 80%.

Comparative Example 1 21.549 4,4'-diaminodiphenyl ether was collected in a 500 tl four-eye flask, and 245.00 g
of N,N-dimethylacetamide was added and dissolved.

On the other hand, 23.46'j of pyromellitic dianhydride was collected in a 100M eggplant flask and added in solid form to the 4,4'-diaminodiphenyl ether solution.

Furthermore, this 100111! The pyromellitic dianhydride remaining on the wall of the eggplant flask was poured into the reaction system (four-eye flask) with to, oo g of N,N'-dimethylacetamide. Stirring was further continued for 1 hour to obtain a 15% by weight polyamic acid solution. The reaction temperature is 5
It was kept at ~10°C. However, in the above operations, the pyromellitic dianhydride was handled and the inside of the reaction system was placed under a stream of dry nitrogen.

Next, these polyamic acid solutions were cast onto a glass plate, and after drying at about 100°C for about 60 minutes, the polyamic acid coating was peeled off from the glass plate, and the coating was fixed on a support frame. ℃ for about 30 minutes, about 200℃ for about 60 minutes,
The mixture was heated at about 300° C. for about 60 minutes, and after dehydration and ring closure drying, a polyimide film of 15 to 25 microns was obtained. This film exhibited the following properties.

Linear expansion coefficient (at 200℃) 3.5 XIQ'
("C') Humidity expansion coefficient 2.5X1G"s
(%RH-Y) Elongation
86% Comparative Example 2 3.3゛-dimethyl-4,4 in a 500u four-way flask
'-diaminobiphenyl 14.809 was collected and 16
0.009 of N,N-dimethylacetamide was added and dissolved, and 15.209 of pyromellitic dianhydride was reacted according to the method of Comparative Example 1 to obtain a 15% by weight polyamic acid solution. However, the pyromellitic dianhydride remaining on the final wall was poured into the reaction system (four-eye flask) with 1.0.009 N,N-dimethylacetamide.

Next, according to the method of Comparative Example 1, a polyimide film was obtained from this polyamic acid solution. This film exhibited the following properties.

Linear expansion coefficient (at 200℃') -L, OXl0-
'('C-'') Humidity expansion coefficient 0.25X
10' (%RH-1)
4% Comparative Example 3 4,4'-diaminodiphenyl ether 7.089 and 3.3'-dimethyl-4 were added to a 500 mi four-eye flask.
, 4'-diaminobiphenyl 7.509 was collected and 16
0.009 of N,N-dimethylacetamide was added and dissolved, and 15.429 of pyromellitic dianhydride was reacted according to the method of Comparative Example 1 to obtain a 15% by weight copolyamic acid solution. However, the pyromellitic dianhydride remaining on the final wall was poured into the reaction system (four-eye flask) with 10.00 g of N,N-dimethylacetamide.

Next, according to the method of Comparative Example 1, a copolyimide film was obtained from this copolyamic acid solution. This film exhibited the following properties.

Linear expansion coefficient (at 200℃) 0.7 x 10'
('C') Humidity expansion coefficient 1.0XIO
5 (%RH-1) Elongation
8% Example 1 5001! Collect 7.08 g of 4,4'-diaminodiphenyl ether in L1 four-eye flask, and add 110.009 g of 4,4'-diaminodiphenyl ether.
of N,N-dimethylacetamide was added and dissolved.

On the other hand, 15.42 g of pyromellitic dianhydride was collected in a 50TIL eggplant flask and added in solid form to the 4,4'-diaminodiphenyl ether solution.

Furthermore, the pyromellitic dianhydride remaining and adhering to the wall of this 50 m eggplant flask was poured into the reaction system (four-eye flask) with 10.00 g of N,N dimethylacetamide, and stirring was continued for an additional hour. On the other hand, 7.50 g of 3,3'-dimethyl-4゜4'-diaminobiphenyl was collected in a 50III Erlenmeyer flask, and 50.009 of N,N
-Dimethylacetamide was added and dissolved. This solution was added into the reaction system (four-eye flask) to obtain a copolyamic acid solution. In the above reaction operation, the reaction temperature is 5 to 10
The handling of pyromellitic dianhydride and 3,3'-dimethyl-4,4'-diaminobiphenyl and the inside of the reaction system were carried out under a stream of dry nitrogen. Next, a copolyimide film was obtained from this copolyamic acid solution according to the method of Comparative Example 1. This film exhibited the following properties.

Coefficient of linear expansion (at 200°C) 0.2. X1O-5
('C-1') Humidity expansion coefficient 0.35X 10
″5 (%RH-1) Elongation
45% Example 2 3,3'-dimethyl-4,4 in a 500d four-way flask
'-Diaminobiphenyl 7.50g was collected and 110g
．． 009 N,N-dimethylacetamide was added and dissolved. On the other hand, 15.429 pyromellitic dianhydride was collected in a 50111 eggplant flask and added in solid form to the 3°3'-dimethyl-4,4'-diaminobiphenyl solution. Furthermore, io, oo 9! of N,N dimethylacetamide was poured into the reaction system (four-eye flask), and stirring was continued for an additional hour. On the other hand, 100
7.089 g of 4,4'-diaminodiphenyl ether was collected in an M1 Erlenmeyer flask, and 50.00 g of N,N-dimethylacetamide was added thereto to dissolve it. This solution is added to the reaction system (
A copolyamic acid solution was obtained. In the above reaction operation, the reaction temperature was 5 to 10°C,
The handling of pyromellitic dianhydride and 4°4'-diaminodiphenyl ether and the inside of the reaction system were carried out under a stream of dry nitrogen. Next, according to the method of Comparative Example 1, a copolyimide film was obtained from this copolyamic acid solution. This film exhibited the following properties.

Linear expansion coefficient (at 200'C) 0.2 xlO'
('C-') Humidity expansion coefficient 0.35X 1
0' (%RH-1) Elongation
42% (Effect of the invention) The polyimide film obtained from the polyimide copolymer of the present invention has a small coefficient of linear expansion and a coefficient of humidity expansion, and has excellent dimensional stability. It has the effect of having mechanical strength such as flexibility and elongation, heat resistance, and processability that polyimide membranes cannot have.

Claims (6)

[Claims] (1) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_1 and R_2 are divalent organic groups, however, R_1 and R
＿2 each have ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲
There are mathematical formulas, chemical formulas, tables, etc.▼, unless ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_0 is a tetravalent organic group, m is a tetravalent organic group A polyimide copolymer consisting of repeating units represented by a positive integer. (2) R_1 is a ▲ mathematical formula, chemical formula, table, etc. [In the formula, X is a hydrogen atom or a monovalent substituent, n is an integer from 1 to 3], and R_2 is The polyimide copolymer according to claim 1, which is ▼. (3) R_1 is ▲ There are numerical formulas, chemical formulas, tables, etc. ▼ and R_2 is ▲ There are ▲ mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, X is a hydrogen atom or a monovalent substituent, and n is 1 to 3 integer] The polyimide copolymer according to claim 1. (4) R_0 has ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas, chemical formulas,
The polyimide copolymer according to claim 1, which is at least one member selected from the group consisting of ▼ and ▲ mathematical formulas, chemical formulas, tables, etc. ▼. (5) The polyimide copolymer according to claims 1, 2, and 3, wherein R_0 is ▲a numerical formula, a chemical formula, a table, etc.▼. (6) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [In the formula, R_0 is a tetravalent organic group] Organic tetracarboxylic dianhydride (A) represented by the following and 50 to 90 mol% of this An organic diamine compound (B) represented by the general formula H_2N-R_1-NH_2 [wherein R_1 is a divalent organic group] is reacted in an organic polar solvent to form a precipitate having acid anhydride groups at both ends. After obtaining the polymer, the general formula H_2N-R_2-NH_2 [In the formula, R_2 is a divalent organic group, however, R_1 and R_2 are respectively ▲ mathematical formulas, chemical formulas, tables, etc. ▼, ▲ mathematical formulas,
There are chemical formulas, tables, etc. ▼ If ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas, chemical formulas,
There is a table etc. ▼] If the total organic diamine amount [(B) + (C)] is substantially the same as the organic tetracarboxylic dianhydride (A), 1. A method for producing a polyimide copolymer, which is obtained by thermally or chemically dehydrating and ring-closing a polyamic acid copolymer obtained by addition reaction so as to have equimolar amounts.