JPS606727A - Novel polyimide resin and its production - Google Patents

Abstract

PURPOSE:A polyimide resin substantially free of coloration and excellent in transparency and heat resistance, composed substantially of repeating units obtained by reacting a specified alicyclic tetracarboxylic acid dianhydride with an aromatic diamine. CONSTITUTION:A polyimide resin having at least 90mol%, based on the total repeating units, structural units of formula I (wherein R is a bivalent aromatic hydrocarbon group). This polyimide resin is produced by polycondensing (A) an acid dianhydride component containing at least 90mol% 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride with (B) a diamine component containing at least 90mol% aromatic diamine of formula III (e.g., p-phenylenediamine) at about -20-150 deg.C, preferably by a solution polymerization process, and dehydrating the product to effect ring closure by heating at about 150-400 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel polyimide coffin resin and a method for producing the same [
More specifically, the present invention relates to a novel polyimide resin in which molded products of the resin have excellent transparency with almost no coloration and good heat resistance, and a method for producing the same.

Polyimide resin is a linear polymer obtained by the reaction of aromatic tetracarboxylic dianhydride such as pyromellitic dianhydride with aromatic diamine, and has high tensile strength, strong durability, and excellent sleep insulation. On top of exhibiting durability and odor resistance,
It is characterized by excellent heat resistance.

Therefore, it is suitable for use as heat-resistant films, adhesives, molding resins, laminated resins, and fibers.In recent years, these properties have been fully utilized to produce automotive parts, special mechanical parts, electrical and electronic materials, and space products.・Applications to aircraft materials, etc. are becoming more popular.
It's coming.

On the other hand, one of the external features of these heat-resistant aromatic polyimide resins is that they are colored amber.

In recent years, this polyimide resin has come to be used as a kind of optical film or as a display material (for example, a liquid crystal alignment film of a liquid crystal display element). However, since the aromatic polyimide mentioned above is colored, its transmittance decreases, causing problems in such applications, and in some cases making it impossible to use. At present, almost no effect can be seen in reducing this coloring.

Furthermore, it is known that one way to reduce this coloring is to polymerize polyimide by reacting an aliphatic tetracarboxylic acid dianhydride with a diamine to obtain a polyimide with relatively little coloring and good transparency. It is being But 7
However, such aliphatic polyimides have a major drawback in that their heat resistance is extremely low, and the first characteristic of polyimides, which is resistance, is lost.

The present inventors have discovered a polyimide resin that overcomes these conventional drawbacks and has no coloration, excellent transparency, and excellent heat resistance. At least 90 mail 1 of repeating units obtained by the reaction of dianhydride and aromatic diamine
We have completed the present invention by discovering the fact that the polyimide 4iJ resin having the above properties has almost no coloring, is extremely transparent, and has excellent one-sided heat resistance.

That is, the present invention is a novel polyimide (having L.1 fat) in which at least 901nOj of the repeating unit is composed of the JM-i position of the following formula 1't, \, /CI' (In the formula, R represents a divalent aromatic hydrocarbon group) At least 9θInOj? ．．
8-Tetracarboxylic acid dianhydride (containing tetracarboxylic dianhydride and at least 90 mQil% of the following formula 1)
Polycondensation with an aromatic diamine represented by 'n+'1,
Next, at least 90 mai1% of the repeating units to be dehydrated and ring-closed are polyimide-like 1-fat P! represented by the following formula (g). ! The manufacturing method is km.

(:11□ ("011n(, -J(-N)+2 It is necessary that the number of structural units contained in the polyimide resin is at least 90 mal 4 or more, and if it is less than this, it will not be possible to obtain a polyimide resin with good transparency and heat resistance, which is the objective of the present application.

Polymers containing the above-mentioned structure have hitherto been completely unknown. Furthermore, polyimide 4iJ resin using such a specific alicyclic tetracarboxylic acid dianhydride gold is hardly present, and it has an extremely excellent transparency. Furthermore, unlike ordinary aliphatic polyimides, Vi is characterized by extremely high heat resistance. Furthermore, it has many characteristics and advantages, such as being resistant to attack by many chemicals such as organic solvents, acids, and alkalis, and having excellent chemical resistance.

As described above, the polyimide resin according to the present invention has good transparency, heat resistance, and FQt quality, so it is particularly suitable for display materials (
For example, it is suitable for use as a base film of a transparent conductive film or a liquid crystal alignment film. Furthermore, it can be applied to films, sheets, enamels, siminates, eyelids, eyelids, etc.

Although the method for synthesizing the compound (2) having the above structural formula used in the present invention is not limited to 11゛''-,
For example, it can be synthesized by the method disclosed in Japanese Patent Application No. 58-45509.

To achieve all of the original objectives of the present invention, the tetracarboxylic dianhydride used must contain at least 9°moA% of the compound [
However, as long as it does not impair high attractability and heat resistance, a part of it must be added to other tetracarbon m2.
Anhydrides, such as aromatic acid anhydrides such as hyromellitic dianhydride, benzophenonetetracarboxylic acid dianhydride, pi-hydrate, and fats such as butanetetracarboxylic dianhydride)
There is no problem in using tetracarboxylic anhydride or the like.

'$ The aromatic diamine (b) used in the invention is
It is not limited to % as long as it does not impair the purpose of the present invention. Representative examples include p-phenylene diamine, n-phenylene diamine, diaminodiphenylmethane, diaminodiphenyl ether, 2,2-cyamino diphenyl phenylene, diaminodiphenylsulfone,
Diaminobenzophenone, diaminonaphthalene, 1゜6
-bis(4-aminophenoquine)benzene, 1,4-bis(4-aminophenoquine)benzene, 4,4'-9
(4-aminophenoquine)diphenylsulfone, 2,2
'-Bis(4-(4-aminoneenoxy)phenyl)propane, etc. These aromatic diamines are used at least 90 moji! S, but are limited to one type, and ij: fz < , 2 Furthermore, depending on the use of the polyimide in the present invention, it is naturally preferable to select a variety of these aromatic diamines for the purpose of imparting particularly suitable properties. For the purpose, it is acceptable to replace a part of the aromatic diamine used in at least 90 malt S with aliphatic diamine, alicyclic diamine, etc. It is particularly important to fully use aromatic diamines in order to fully impart heat resistance to the polyimide resin, which is one of the features of the present invention. The properties and heat resistance will be insufficient.

The polyimide of the present invention is obtained by polycondensing at least 90% of the tetracarboxylic dianhydride (9) and the aromatic diamine (2) to form a so-called polyamic acid, and then dehydrating and ring-closing the polyimide. The polymerization method is not particularly limited, and may include solution polymerization, interfacial bonding,
Either bulk bonding, solid phase bonding, etc. may be employed. The above polymerization reaction may be carried out in a one-step process in which the polyamic acid to be produced is converted into polyimide without further treatment, or the polyamic acid thus produced is subjected to dehydration and ring closure, A two-step method using polyimide may also be used. Furthermore, when 00 tetracarboxylic m2 anhydride with a content of 9 n mo/% or less is used, the heat cauterization resistance and transmissive QIJ properties of 4r+.1 fat are insufficient.

In the present invention, a solution method is usually preferred.

The solvent used in the solution method is not limited to /i5' as long as it dissolves the produced polyamic acid. A typical example is i, J:, N, 11-
Dimethylfornoamide, N,N-dimethylacetamide, N-methylpyrrolidone, 11-methylglolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone, hexamethylphosphoramide,
Examples include butyrolactone. These may be used alone or in combination.

Furthermore, even if the solvent does not dissolve polyamic acid, it may be added to the above solvent as long as it can dissolve polyamic acid.

In the polymerization in the present invention, the molar ratio of the tetracarponic anhydride (00) and the aromatic diamine (b) is 05 to 2, preferably 09 to 1.1. Can be done.

As in a normal polycondensation reaction, the closer the molar ratio of these two components is to 1, the higher the molecular weight of the polyamic acid produced.

The reaction temperature of the polycondensation reaction for producing polyamic acid can be any temperature from -20°C to 150°C, but especially -
A range of 5°C to 100°C is preferred.

In the present invention, in order to convert polyamic 02 into polyimide, a method of dehydration and ring closure by heating is usually used. The temperature for this thermal dehydration ring closure is 150°C to 400°C.
C. Preferably, any temperature from 170.degree. C. to 650.degree. C. can be selected. Although the time required for this dehydration ring closure depends on the reaction temperature, it is appropriate to take 60 seconds to 10 hours, preferably 5 minutes to 5 hours. Further, as another method for converting polyamic resin into polyimide, a method of chemically ring-closing using dehydration ring-closing & lecturing is also available. Regarding these methods, known methods used in ordinary polyimide synthesis can be employed as they are, and the conditions are not particularly limited.

Next, the present invention will be further explained in detail with reference to Examples. The transparency and heat resistance of polyimide were evaluated by the following method.

1) Transmittance Parallel light transmittance was measured using a digital colorimeter manufactured by Suga Test Co., Ltd.

2) Heat component 'F N7 richness εa Using DDS1560 type manufactured by Niko Kosha, heating rate 1
Thermal ashing analysis was conducted in a nitrogen stream at Ω°C/min, and the temperature at which the weight decreased by 5 cm was taken as the thermal decomposition temperature.

6) Viscosity measurement An N,N-dimethylpolamide solution having a solid QM content of 05 weight was measured at 60°C using an Ubbelohde viscometer.

Example-1-(11 2,2-bis[4-(4-aminophenoxy)phenyl]propane+21yiN,N-dimethylformamide 1
89 me ICjjD, J beans stirred to make a homogeneous solution, Bicyclo [ro, s, o] octane-2゜3:6,8
-Tetracarboxylic 5゛2 dianhydride (7.52%) was added and stirring was continued for 6 hours at room temperature, resulting in a thin brownish viscous liquid. When this viscous liquid was precipitated in a large amount of toluene, 17.61i' of a white solid was obtained. As a result of dissolving this solid in N-dimethylformamide and measuring its viscosity, the reduced viscosity ηap10
= 0.8 d4/f.

Example-1-(2) The polyamic acid 3y obtained in Example-1-(1) was
N-dimethylformamide was added to 1 s me vcm M, and the resulting viscous liquid was diluted with 75 μm using a doctor knife.
Cast on a glass plate to a thickness of 150℃ for 10 minutes at 8℃
'C30 minutes, 250'C dried for 1 hour, thickness 1
A uniform film of 0μ was obtained. IR of this film
The spectrum (Figure 1) shows a 5-membered ring imide (+70[1
, 1770rB, -' 6-membered ring imide (1700, 17
10) The characteristic absorption band is clear, and the next 1tl
It was confirmed that the material was made of synthetic polyimide.

OH7 Also, this film was almost colorless in appearance, had good transparency, and had a strong VJ.

Example-2 2,2-bis(4-(4-aminophenoxy)phenyl)propane was added to 20.5 fi'iN, 515 me of N-dimer-formamide and stirred to uniformly dissolve Pi.
'After A5, Bicyclo [s, s, 0': J octa 7
-2.3:6.8-tetracarboxylic dianhydride 12.5
7 was added and stirring was continued at room temperature for 8 hours. The reduced viscosity of the obtained viscous liquid was ηθp10 = 1.2 μ/7. This viscous liquid was cast onto a glass plate to a thickness of 600μ using a doctor knife, and then cast at 80°C for 15 minutes and then at 150°C for 5 minutes.
It was dried for 0 minutes at 250°C for 1 hour. The obtained film had a thickness of 50 μm and was homogeneous with a thin brownish tinge, and it was confirmed from the engineering R spectrum that it had been converted to 100 polyimide. This film had a transparency of aEEHao91 and a thermal decomposition temperature of 445° C., indicating extremely excellent transparency and good heat resistance.

Example 5 Diaminodiphenyl ether 647 was added to 10'0ml of N,N-dimethylacetamide, stirred to make a homogeneous solution, and then bicyclo[3; 3.0]]octane-2.3:6.8-tetracarboxylic acid di Anhydride 8 OS”
<When added and continued stirring at room temperature for 8 hours, the reduced viscosity η
It became a viscous liquid with FIp10 = 0.13 U/f. This was cast onto a glass plate to a thickness of 600μ using a doctor knife, and cast at 80°C for 15 minutes and at 150°C for 30 minutes for 25 minutes.
It was dried at 0°C for 1 hour. Obtained films i, j JI7
It was 50 μm in diameter and had a uniform thin brownish tint, and it was confirmed from the engineering R spectrum that it was Sumizuko's polyimide as shown below.

H2 The transmittance of this film is 801 degrees, and the thermal decomposition temperature is 462 degrees Celsius.
It was extremely transparent and had good heat resistance.

Example-4 10 liters of viscous polyamic acid solution obtained in Example-6
4, anhydrous vinegar 1'il 0.57 me, Dolysine 02
After mixing rapidly, the mixture was cast onto a glass plate to a thickness of 100μ using a doctor knife.

When this was dried at 80° C. for 10 minutes and at 150° C. for 50 minutes, a good coating film that firmly adhered to the glass plate was obtained. This coating 11Q ij: , outside? 151 has no coloration at all, has good transparency, and has a good contrast with the engineering R spectrum.
% polyimide was confirmed.

Comparative Example-1 Bicyclo[5,ro,0]octane-2,,5:6.8-
A polyamic acid solution was prepared in the same manner as in Example 2, except that pyromellitic dianhydride was used instead of tetracarboxylic dianhydride. A light brown viscosity, 117
An amorphous overnight body is obtained, and its reduced viscosity is ηBp/C=2
．． It was 6 dg/f. When the entire film was prepared in the same manner as in Example 2, a homogeneous film colored a deep yellow was obtained. This film had a thickness of 5]1 μm, a transmittance e of 69 cm, and a thermal decomposition temperature of 1” 1473° C., indicating high heat resistance but poor transparency.

Comparative example-2 Bicyclo [ro, 3.0]] octane-2.5:6.8
- Polyamic 1,2j solution was prepared in the same manner as in Example 3, except that pyromellitic dianhydride was used instead of haze. A viscous liquid is obtained, and this reduced viscosity rRn,
17op10 = 3.2 a, h at gz/7. As in Example-2, firun, 'f:? When A was prepared, a uniform film with one color of deep yellowish brown (c) was obtained.

The thickness of this film is 50 μ, the transmittance is 480 cm, q,
l, %, minute 1'l'ri':'iA +! := 530
℃, i! j1 Thermal force is very strong; Extremely heavy printing 1
It was less than life.

[Brief explanation of drawings]

The figure shows infrared absorption 1 of the new polyimide resin produced in Example 1.
17 spectra are shown. 11! ? Previously cited C. 1 person Self-purification re =-,: Kogyo Co., Ltd. Procedural Amendment (Voluntary) May 1980 N Day 1 Indication of the case 1982 Patent Application No. 114934 2 Name of the invention Relationship with the case Patent application Address ■ 3-7 Kanda Nishikicho, Chiyoda-ku, Tokyo 101@Ji1
4. The scope of claims in the specification to be amended and the invention in the description are corrected as shown in the attached document. 3) In specification C), page 5, lines 6-7 from the bottom, "-Hycyclo(3,3,0)octane-2,3:6.8-tetracarboxylic acid 2 ``Ice product'' is corrected to ``3.5.6-, tricarbonide cysimethyl norbornane 2:3.5:6 diiceless product.'' 4) Correct the statement on page 6, line 1 of the specification. 5) Correct the statement on the 12th line from the bottom of the 6th line of the specification. 6) Ming II, page 13, lines 8-9, 1, page 14, lines 2-3 from the bottom, page 15, lines 14-15, page 13, lines 8-9
Line 1, line 15-16 [-Bishiri1ko(3,3,0
) octane-2,3:6.8-tetracarboxylic acid dianide" is replaced with "3.5.6-1-ricacyboxy-2
-carboxynotyl nor! ζ Lunan 2: 3.5: G dianhydride” also corrects 1. 7) Corrected the statement on page 14, line 8 of the specification section. I'll correct that. > Mr. Ei 2, ``l!l scope of claims i]) 14. At least b of Th return ji'lj2
90 m o 1% is 11.) of the following formula [1] iii
A new boliimi 1゛ tree j finger consisting of T position. (In the formula, R represents a divalent aromatic hydrocarbon group) (2)
At least 90 mo1% of diamines represented by the following formula (II) are polycondensed with at least 90 mo1% of an aromatic diamine represented by the following formula -U, and then nQ Mizuho envy. A method for producing a novel polyimide resin in which at least 90 mo1% of the repeating units are represented by the following formula (IV).

Claims (2)

[Claims] (1) Kt”f; at least 90 mai per repeat unit
A novel polyimide resin in which b is a small unit of the following formula [tl'\ component of I. (In the formula, R represents a divalent aromatic hydrocarbon group. (2) Bicyclo[3,3,0,1 octane-2,s represented by the following formula [1111] of at least 90 zno
: 6. Tetracarboxylic dianhydride containing s-tetracarboxylic acid dihydride is subjected to total polycondensation with at least 90 mo/% of diamines containing aromatic diamine represented by the following formula (2), and then dehydration and closure. Soaking t-at least ql of repeating units characterized] mo, A
% is a new polyimide (91
Method of producing fat. [10NF2- R-NF2 (wherein R1':j represents a divalent aromatic hydrocarbon group)