JP2020125466A - Polyimide alloy, polyimide alloy precursor resin composition, polyimide alloy precursor resin solution, and method for producing polyimide alloy - Google Patents

Abstract

To provide a polyimide alloy which can have sufficiently high heat resistance while having sufficiently high transparency.SOLUTION: A polyimide alloy is composed of cyclic aliphatic polyimide that is a polycondensate of a cyclic aliphatic tetracarboxylic acid dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamine and aliphatic diamine; and wholly aromatic polyimide that is a polycondensate of at least one aromatic tetracarboxylic acid dianhydride selected from the group consisting of a diphenyl-3,3',4,4'-tetracarboxylic acid dianhydride and benzene-1,2,4,5-tetracarboxylic acid dianhydride, and aromatic diamine, and has a content of the cyclic aliphatic polyimide to the total amount of the cyclic aliphatic polyimide and the wholly aromatic polyimide of 62-95 mass%.SELECTED DRAWING: None

Description

The present invention relates to a polyimide alloy, a polyimide alloy precursor resin composition, and a method for producing a polyimide alloy.

Conventionally, a polyimide alloy (polyimide resin composition) is known as a composite material of two or more kinds of polyimides. For example, in JP-A-3-152212 (Patent Document 1), JP-A-2000-191907 (Patent Document 2) and JP-A-2000-204249 (Patent Document 3), all are wholly aromatic polyimides. Mutual polyimide alloys are disclosed. However, the polyimide alloys described in Patent Documents 1 to 3 cannot sufficiently reduce the yellowness (YI), and have sufficiently high transparency based on the yellowness and the total light transmittance. I couldn't.

Regarding the general-purpose wholly aromatic polyimide, refer to pages 102 to 128 of the publication "Latest Polyimide-Basics and Applications-(New Edition)" published by NTS Co., Ltd. in 2010. In "Chapter 5 Optical Properties of Polyimides" (Non-Patent Document 1), diphenyl-3,3',4,4'-tetracarboxylic dianhydride (also known as "3,3',4,4"). A polyimide (BPDA/PDA) synthesized from'-biphenyltetracarboxylic dianhydride: BPDA) and p-phenylenediamine (PDA) is exemplified, and a film composed of such an aromatic polyimide (BPDA/PDA). Is disclosed to be colored yellow-brown to dark brown.

JP-A-3-152212 JP-A-2000-191907 JP-A-2000-204249

Chapter 5 Optical Properties of Polyimide, Publication Name: Latest Polyimide-Basics and Applications-(New Edition), Publisher: NTS Corporation, 2010, 102-128 pages

The present invention has been made in view of the above problems of the prior art, and a polyimide alloy capable of having a sufficiently high degree of heat resistance while having a sufficiently high degree of transparency; To provide a polyimide alloy precursor resin composition and a polyimide alloy precursor solution, which can be preferably used for producing the polyimide alloy, and a method for producing the polyimide alloy, which can efficiently produce the polyimide alloy. To aim.

First, when the prior art is examined, all of the polyimide alloys described in Patent Documents 1 to 3 described above are composed of wholly aromatic polyimide. Here, it is known that such wholly aromatic polyimide basically has a high degree of yellowness (YI) and is colored from yellowish brown to brownish brown (see Non-Patent Document 1 above). It should be noted that such coloring of the aromatic polyimide is generally caused in the field of polyimide by the fact that light absorption occurs due to a strong interaction between the molecules (formation of a CT complex (Charge Transfer complex)). It is believed to occur. As described above, the wholly aromatic polyimide is colored yellowish brown to dark brown and has a high degree of yellowness (YI). Therefore, when it is used in applications where transparency is required, for example, in optical applications, the degree of yellowness is low. There's a problem. On the other hand, in the said patent documents 1-3 and the said nonpatent literature 1, a polyimide alloy (composite material of polyimide molecules: polyimide resin composition) is formed using a wholly aromatic polyimide and an aliphatic polyimide. No such description is given, and a polyimide alloy composed of these components is not known. In the field of polyimide, an aliphatic polyimide is generally known as a material having high transparency but not necessarily sufficient heat resistance as compared with a wholly aromatic polyimide.

In view of such a conventional technique, the present inventors have conducted intensive studies to achieve the above object, first, with respect to wholly aromatic polyimide, yellow degree is sufficiently low as an aliphatic polyimide, We examined whether to mix cycloaliphatic polyimide, but even if you simply mix cycloaliphatic polyimide with wholly aromatic polyimide, for the resulting polyimide alloy, the cycloaliphatic polyimide is not sufficiently low It has been found that the degree of yellowness cannot be reflected and the transparency of the polyimide alloy cannot always be high. Based on such knowledge, as a result of further intensive studies by the present inventors, while selecting and using a specific cycloaliphatic polyimide described below from the cycloaliphatic polyimide, among the wholly aromatic polyimides From the below, a specific wholly aromatic polyimide described below is selected and used, and further, by containing these at a specific content ratio, surprisingly, in the polymer alloy (polyimide alloy) obtained, the yellowness is remarkably increased. It is possible not only to reduce it to a sufficiently high degree of transparency, but also to fully reflect the high degree of heat resistance of the wholly aromatic polyimide and to exhibit excellent heat resistance. The present invention has been completed, and the present invention has been completed.

That is, the polyimide alloy of the present invention,
A cycloaliphatic polyimide which is a polycondensate of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. ;as well as,
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyimide which is a polycondensation product of an acid dianhydride and an aromatic diamine;
Consists of, and
The content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass.

Further, the polyimide alloy precursor resin composition of the present invention,
Cycloaliphatic polyamic acid which is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines An acid, and at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid;
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyamic acid which is a polyaddition product of an acid dianhydride and an aromatic diamine;
Consists of, and
Based on the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the cyclic Containing the cycloaliphatic polymer and the wholly aromatic polyamic acid at a ratio such that the content of the cycloaliphatic polyimide with respect to the total amount of the aliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass. It is characterized by.

Furthermore, the polyimide alloy precursor resin solution of the present invention,
Cycloaliphatic polyamic acid which is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines An acid and at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid;
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyamic acid which is a polyaddition product of an acid dianhydride and an aromatic diamine; and
solvent;
Contains, and
Based on the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the cyclic Containing the cycloaliphatic polymer and the wholly aromatic polyamic acid at a ratio such that the content of the cycloaliphatic polyimide with respect to the total amount of the aliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass. It is characterized by.

Further, the method for producing a polyimide alloy of the present invention,
Cycloaliphatic polyamic acid that is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride containing an aliphatic 6-membered ring and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines And a solution of at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid,
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride A solution of wholly aromatic polyamic acid, which is a polyaddition product of an acid dianhydride and an aromatic diamine,
Where, based on the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, A step of obtaining a polyimide alloy precursor resin solution by mixing the cycloaliphatic polyimide and the wholly aromatic polyimide at a ratio such that the content of the cycloaliphatic polyimide is 62 to 95 mass% with respect to the total amount (A). When,
By heating and curing the polyimide alloy precursor resin solution,
A cycloaliphatic polyimide which is a polycondensate of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. And at least one fragrance selected from the group consisting of diphenyl-3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Group tetracarboxylic dianhydride and wholly aromatic polyimide which is a polycondensation product of aromatic diamine; and containing the cyclic aliphatic polyimide and the cyclic aliphatic polyimide with respect to the total amount of the wholly aromatic polyimide. A step (B) for obtaining a polyimide alloy having an amount of 62 to 95% by mass,
The method is characterized by including.

According to the present invention, a polyimide alloy capable of having a sufficiently high degree of transparency while having a sufficiently high degree of transparency; a polyimide alloy that can be suitably used for producing the polyimide alloy It is possible to provide a precursor resin composition and a polyimide alloy precursor solution; and a method for producing a polyimide alloy capable of efficiently producing such a polyimide alloy.

It is a chromatogram obtained by GPC analysis of cyclic aliphatic polyamic acid varnish (A). It is a chromatogram obtained by GPC analysis of wholly aromatic polyamic acid varnish (B). It is a chromatogram obtained by GPC analysis of the mixed varnish (C). It is a chromatogram obtained by GPC analysis of polyamic acid varnish (D). Relationship between YI of the polymers (polyimide alloys or polyimides) obtained in Examples 1 to 4 and Comparative Examples 1 to 8 and the content ratio (% by mass) of the varnish (B) in the varnish used for the preparation of the polymers. It is a graph which shows.

Hereinafter, the present invention will be described in detail with reference to its preferred embodiments.

[Polyimide alloy]
The polyimide alloy of the present invention is polycondensed with a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. Selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride. At least one aromatic tetracarboxylic dianhydride and a wholly aromatic polyimide which is a polycondensation product of an aromatic diamine; and, based on the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide. The content of the cycloaliphatic polyimide is 62 to 95% by mass. Hereinafter, first, the cyclic aliphatic polyimide and the wholly aromatic polyimide will be described separately.

<Cyclic aliphatic polyimide>
The cycloaliphatic polyimide according to the present invention is a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure, and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. It is a polycondensation product of.

The cycloaliphatic tetracarboxylic dianhydride has an aliphatic 6-membered ring structure. Here, the “aliphatic 6-membered ring structure” may be a ring having 6 carbon atoms forming the cyclic structure portion, and for example, a ring having 6 carbon atoms may be used. As long as it contains a structure, it may have a structure of a so-called bridged ring (for example, a norbornane ring) in addition to the structure of a cyclohexane ring. Thus, in the present invention, the “aliphatic 6-membered ring structure” means, for example, when a polycyclic structure is formed (for example, a bicyclic ring structure containing a crosslinked structure such as a norbornane ring structure or a bicyclooctane ring structure). Structure), the number of carbon atoms in any one of the cyclic structures may be six.

Such an aliphatic 6-membered ring structure is not particularly limited, but for example, the following formulas (i) to (iii):

The cyclic structure represented by As such an aliphatic 6-membered ring structure, from the viewpoint that higher heat resistance can be obtained, the cyclic structure (structure of cyclohexane ring) represented by the general formula (i), the general formula (ii) ) Is preferable, and the cyclic structure represented by the general formula (ii) is more preferable.

Examples of the cyclic aliphatic tetracarboxylic acid dianhydride having such an aliphatic 6-membered ring structure include, for example, the following general formula (I):

[X ¹ represents a tetravalent organic group having the aliphatic 6-membered ring structure. ]
The tetracarboxylic dianhydride represented by The tetravalent organic group having an aliphatic 6-membered ring structure, which can be selected as X ¹ in the formula (I), may be any ^one having the aliphatic 6-membered ring structure. Various atoms such as a hydrogen atom and an atom other than a hydrogen atom, and other substituents (including other organic groups) may be bonded to the carbon atom forming the group 6-membered ring structure.

As such X ¹ , among the following, from the viewpoint of transparency and heat resistance, the following formulas (a) to (c):

[In the formula (c), R ¹ , R ² and R ³ each independently represent one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and n is 0 to 12 Indicates an integer of. Further, in the formulas (a) to (c), the symbols *1 to *4 indicate that each of the bonds having the symbol is ^one of the four bonds bonded to X ^1. Show. ]
A tetravalent organic group represented by is preferable.

Here, the number of carbon atoms of the alkyl group that can be selected as R ¹ , R ² , and R ³ in the formula (c) is preferably 1 to 6 from the viewpoint of easier purification. It is more preferably -5, more preferably 1-4, and particularly preferably 1-3. The alkyl group which can be selected as R ¹ , R ² and R ³ may be linear or branched. Furthermore, as such an alkyl group, a methyl group and an ethyl group are more preferable from the viewpoint of easy purification. Further, R ¹ , R ² , and R ³ in the formula (c) are each independently a hydrogen atom, a methyl group, an ethyl group, from the viewpoint that a high degree of heat resistance can be obtained when a resin is produced. It is more preferably an n-propyl group or an isopropyl group, further preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom. Further, it is particularly preferable that the plurality of R ¹ , R ² and R ³ in the formula (c) are the same from the viewpoint of easiness of purification and the like. Furthermore, regarding n in the general formula (c), the upper limit is more preferably 5 (particularly preferably 3) from the viewpoint of easier purification, and from the viewpoint of stability of the raw material compound. The lower limit value is more preferably 1 (particularly preferably 2), and particularly preferably 2. As described above, n in the general formula (c) is particularly preferably an integer of 2 to 3.

Examples of the cycloaliphatic tetracarboxylic dianhydride having such an aliphatic 6-membered ring structure include bicycloheptanetetracarboxylic dianhydride (BHDA) and dimethanonaphthalenetetracarboxylic dianhydride (DNDA). ), bicyclooctane tetracarboxylic acid dianhydride (BODA), dicyclohexane-3,3′,4,4′-tetracarboxylic acid dianhydride (also known as “3,3′,4,4′-bicyclohexyl tetracarboxylic acid Acid dianhydride, [1,1′-bi(cyclohexane)]-3,3′,4,4′-tetracarboxylic dianhydride”: H-BPDA), 1,2,4,5-cyclohexyltetra Carboxylic dianhydride (H-PMDA), [1,1′-bi(cyclohexane)]-2,3,3′,4′-tetracarboxylic dianhydride (alias: [1,1′-bi( Cyclohexane)]-2,2',3,3'-tetracarboxylic dianhydride), 4,4'-methylenebis(cyclohexane-1,2-dicarboxylic anhydride), 4,4'-(propane-2) ,2-diyl)bis(cyclohexane-1,2-dicarboxylic acid anhydride), 4,4′-oxybis(cyclohexane-1,2-dicarboxylic acid anhydride), 4,4′-thiobis(cyclohexane-1,2) -Dicarboxylic acid anhydride), 4,4'-sulfonylbis(cyclohexane-1,2-dicarboxylic acid anhydride), 4,4'-(dimethylsilanediyl)bis(cyclohexane-1,2-dicarboxylic acid anhydride) ,4,4'-(Tetrafluoropropane-2,2-diyl)bis(cyclohexane-1,2-dicarboxylic acid anhydride), octahydropentalene-1,3,4,6-tetracarboxylic acid dianhydride Bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, 6-(carboxymethyl)bicyclo[2.2.1]heptane-2,3,5-tricarboxylic acid Dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]oct-5-ene-2,3,7,8 -Tetracarboxylic acid dianhydride, tricyclo[4.2.2.0 ^2,5 ]decane-3,4,7,8-tetracarboxylic acid dianhydride, tricyclo[4.2.2.0 ^2,5 ] dec-7-ene-3,4,9,10-tetracarboxylic dianhydride, 9-oxatricyclo [4.2.1.0 ^{2, 5]} nonane 3,4,7,8-tetra Carboxylic dianhydride, (4arH,8acH)-decahydro-1t , 4t:5c,8c-dimethanonaphthalene-2c,3c,6c,7c-tetracarboxylic dianhydride, (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethanonaphthalene-2t,3t, 6c,7c-tetracarboxylic dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,3 5,6-Tetracarboxylic acid, (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethanonaphthalene-2c,3c,6c,7c-tetracarboxylic dianhydride, norbornane-2-spiro-α -Cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (CpODA), norbornane-2-spiro-α-cyclohexanone-α'-Spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride, [2,2'-bi(norbornane)]-5,5',6,6'- Tetracarboxylic dianhydride, 1,4-phenylenebis(2-norbornane-5,6-dicarboxylic anhydride), 4,4′-biphenylenebis(2-norbornane-5,6-dicarboxylic anhydride), 4,4″-terphenylene bis(2-norbornane-5,6-dicarboxylic anhydride), trans isomer of cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohexane-1,2 , Cis isomer of 4,4,5-tetracarboxylic dianhydride and the like.

Further, as such a cycloaliphatic tetracarboxylic dianhydride containing an aliphatic 6-membered ring, among others, norbornane-2-spiro-α-cyclopentanone-α′-, from the viewpoint of transparency and heat resistance. Spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride (CpODA), 1,2,4,5-cyclohexyltetracarboxylic dianhydride (H-PMDA) And dicyclohexane-3,3′,4,4′-tetracarboxylic dianhydride (H-BPDA), which is preferably at least one selected from the group consisting of norbornane-2-spiro-α-cyclo. Pentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (CpODA) is particularly preferred. The method for preparing the cycloaliphatic tetracarboxylic dianhydride containing such an aliphatic 6-membered ring is not particularly limited, and a known method can be appropriately used (for example, when preparing CpODA, The method described in International Publication No. 2011/099518 may be appropriately adopted). A commercial product may be appropriately used as the cycloaliphatic tetracarboxylic acid dianhydride containing such an aliphatic 6-membered ring.

The aromatic diamine is not particularly limited, and known aromatic diamines that can be used in the production of polyimide (for example, the aromatic diamine described in paragraph [0039] of JP-A-2018-44180). Etc.) can be appropriately used. Examples of such aromatic diamines include those represented by the formula (X):
^{_{H 2 N-R 10 -NH 2}} (X)
[R< ¹⁰ > in Formula (X) represents an arylene group having 6 to 50 carbon atoms. ]
An aromatic diamine represented by Here, the arylene group that can be selected as R ¹⁰ in the formula (X) includes the following general formulas (10) to (14):

Wherein (10), Q has the _{formula: -C 6 H 4 -, -} C 6 H 4 -C 6 H 4 -, - CONH-C 6 H 4 -NHCO -, - NHCO-C 6 H 4 - _{CONH -, - O-C 6} H 4 -CO-C 6 H 4 -O -, - OCO-C 6 H 4 -COO -, - OCO-C 6 H 4 -C 6 H 4 -COO -, - OCO _{-, - NC 6 H 5 -} , - CO-NC 4 H 8 N-CO -, - C 13 H 10 -, - (CH 2) 5 -, - O -, - S -, - CO -, - CONH _{-, - NHCO -, - SO} 2 -, - C (CF 3) 2 -, - C (CH 3) 2 -, - CH 2 -, - (CH 2) 2 -, - (CH 2) 3 -, _{- (CH 2) 4, -} (CH 2) 5 -, - O-C 6 H 4 -C (CH 3) 2 -C 6 H 4 -O -, - O-C 6 H 4 -C (CF 3 _{) 2 -C 6 H 4 -O -} , - O-C 6 H 4 -SO 2 -C 6 H 4 -O -, - C (CH 3) 2 -C 6 H 4 -C (CH 3) 2 - , —O—C ₆ H ₄ —C ₆ H ₄ —O— and —O—C ₆ H ₄ —O— represent one selected from the group consisting of groups represented by the formula (14): R ^b represents one selected from the group consisting of a hydrogen atom, a fluorine atom, a methyl group, an ethyl group and a trifluoromethyl group. ]
It is preferably at least one of the groups represented by

In addition, as such an aromatic diamine, among others, from the viewpoint that it is possible to achieve higher transparency (for example, a haze with a yellowness value is sufficiently low), 4,4′ -Diaminobenzanilide (abbreviation: DABAN), p-phenylenediamine (also known as "p-diaminobenzene", abbreviation: PPD), 9,9-bis(4-aminophenyl)fluorene (abbreviation: FDA), 2,2' -Bis(trifluoromethyl)benzidine (abbreviation: TFMB), 4,4'-diaminodiphenyl ether (abbreviation: DDE), m-tolidine, 4,4''-diamino-p-terphenyl are preferred, DABAN, PPD, FDA is more preferable, DABAN and PPD are particularly preferable. In addition, such aromatic diamine may be used alone or in combination of two or more kinds.

Further, as the aliphatic diamine, known ones that can be used in the production of polyimide can be appropriately used, and for example, ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine (HMD), 1 ,2-bis(2-aminoethoxy)ethane, polyoxyalkylenediamine, 3,3'-diamino-N-methyldipropylamine, polyalkylaminoalkylenediamine, 4,4'-diamino-dicyclohexylmethane, 3,3 '-Dimethyl-4,4'-diamino-dicyclohexylmethane, 3,3'-diethyl-4,4'-diamino-dicyclohexylmethane, 3,3',5,5'-tetramethyl-4,4'-diamino -Dicyclohexylmethane, 3,3',5,5'-tetraethyl-4,4'-diamino-dicyclohexylmethane, 3,5-diethyl-3',5'-dimethyl-4,4'-diaminodicyclohexylmethane, 1 ,4-bis(aminomethyl)cyclohexane (1,4-BAC), 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4-diaminocyclohexane (trans, cis mixture), trans- 1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,3-diaminocyclohexane (trans, cis mixture), trans-1,3-diaminocyclohexane, cis-1,3-diaminocyclohexane, 1,4 -Xylylenediamine, 1,3-xylylenediamine, isophoronediamine, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, bicyclo[2.2.1]heptanedimethanamine, norbornanediamine (NBDA) Etc. Such aliphatic diamines may be used alone or in combination of two or more.

The diamine compound used to form the polycondensation product of the cyclic aliphatic polyimide may be at least one selected from the group consisting of the aromatic diamine and the aliphatic diamine, Although not particularly limited, DABAN, PPD, FDA, TFMB, DDE, m-tolidine, NBDA, 1,4-BAC, 1,3-BAC, and HMD are particularly preferable from the viewpoint of transparency and heat resistance. DABAN, PPD, FDA, NBDA, 1,3-BAC and HMD are more preferable, DABAN and PPD are particularly preferable.

In addition, such a cycloaliphatic polyimide is a polycondensation product of the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound. The cycloaliphatic polyimide is obtained by subjecting the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound to a ring-opening addition reaction to obtain a polyaddition product (addition polymer, It is obtained by forming a cycloaliphatic polyamic acid which is a ring-opened polyadduct), and then subjecting the cycloaliphatic polyamic acid to ring-closing condensation (dehydration ring-closing: intramolecular condensation). Therefore, it can be said that the cycloaliphatic polyimide is obtained by polycondensation of the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound. In addition, instead of the cycloaliphatic tetracarboxylic dianhydride containing an aliphatic 6-membered ring, a cycloaliphatic tetracarboxylic dianhydride having no aliphatic 6-membered ring structure (for example, 1, 2, When 3,4-cyclobutanetetracarboxylic dianhydride, etc.) is used, it becomes impossible to form a highly transparent polyimide alloy having a sufficiently reduced yellowness.

As a method for obtaining such a cycloaliphatic polyimide, a cycloaliphatic tetracarboxylic dianhydride having the above aliphatic 6-membered ring structure is used as the tetracarboxylic dianhydride, and the diamine compound is used as the diamine. Other than the above, a method similar to the method used in the known method for producing a polyimide, in which a tetracarboxylic dianhydride and a diamine are reacted to form a polyimide, can be used. From the viewpoint of efficiently containing the cycloaliphatic polyimide in the polyimide alloy, the method for producing a polyimide alloy of the present invention described below is adopted to form the cycloaliphatic polyimide from the cycloaliphatic polyamic acid. Is preferred.

Further, as the cycloaliphatic polyimide which is a polycondensation product of the cycloaliphatic tetracarboxylic dianhydride having such an aliphatic 6-membered ring structure and the diamine compound, for example, the following general formula (1):

[X ¹ is a residue obtained by removing two acid anhydride groups from the above cycloaliphatic tetracarboxylic dianhydride (a tetravalent organic group: more preferably, the same " ¹ " as X ¹ in the above formula (I) The above is a tetravalent organic group having an aliphatic 6-membered ring structure”), and X ² is a residue obtained by removing two amino groups from the diamine compound (for example, selected as R ¹⁰ in the above formula (X). Is an arylene group having 6 to 50 carbon atoms that can be formed, or an alkylene group that can be formed by removing two amino groups from the aliphatic diamine). ]
A polyimide having a repeating unit represented by

<Whole aromatic polyimide>
The wholly aromatic polyimide according to the present invention is selected from the group consisting of diphenyl-3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride. Is a polycondensate of at least one aromatic tetracarboxylic dianhydride and an aromatic diamine.

Further, in the present invention, as the aromatic tetracarboxylic dianhydride, diphenyl-3,3′,4,4′-tetracarboxylic dianhydride (BPDA), and/or benzene-1,2, Utilizes 4,5-tetracarboxylic dianhydride (PMDA). When a known aromatic tetracarboxylic dianhydride other than BPDA and PMDA is used instead of such an aromatic tetracarboxylic dianhydride, an alloy having sufficiently high heat resistance should be formed. I can't. The aromatic diamine to be polycondensed with the aromatic tetracarboxylic dianhydride is the same as the aromatic diamine described as the component in the above-mentioned diamine compound (the same applies to the preferred one).

Moreover, such a wholly aromatic polyimide is a polycondensation product of the aromatic tetracarboxylic dianhydride and the aromatic diamine. The wholly aromatic polyimide is obtained by subjecting the aromatic tetracarboxylic dianhydride (BPDA and/or PMDA) and the aromatic diamine to a ring-opening addition reaction to obtain a polyaddition product (addition polymer, It is obtained by forming an aromatic polyamic acid which is a ring-opened polyaddition product) and then subjecting the aromatic polyamic acid to dehydration ring closure (intramolecular condensation). Therefore, it can be said that the wholly aromatic polyimide is obtained by polycondensation of the aromatic tetracarboxylic dianhydride and the aromatic diamine.

As a method for obtaining such wholly aromatic polyimide, tetracarboxylic dianhydride except that the aromatic tetracarboxylic dianhydride is used as the tetracarboxylic dianhydride, and the aromatic diamine is used as the diamine. A method similar to the method used in a known method for producing a polyimide, in which a substance is reacted with a diamine to form a polyimide, can be used. From the viewpoint of efficiently containing the wholly aromatic polyimide in the polyimide alloy, the method for producing a polyimide alloy of the present invention described below is adopted to form a cyclic aliphatic polyimide from an aromatic polyamic acid. preferable. As the aromatic polyamic acid which is a polyaddition product (addition polymer: reaction product) of the aromatic tetracarboxylic dianhydride and the aromatic diamine, a commercially available product (for example, a trade name of Ube Industries, Ltd. It is also possible to form the aromatic polyimide from the polyamic acid (polyamic acid) using “U-varnish-S” or the like.

Examples of such wholly aromatic polyimide include, for example, the following general formula (2):

[X ³ is a residue (tetravalent organic group) obtained by removing two acid anhydride groups from BPDA or PMDA, and X ⁴ is a residue obtained by removing two amino groups from the aromatic diamine (more preferably, It is an arylene group having 6 to 50 carbon atoms that can be selected as R ¹⁰ in the above formula (X). ]
A polyimide having a repeating unit represented by

<Polyimide alloy>
The polyimide alloy of the present invention comprises the cycloaliphatic polyimide and the wholly aromatic polyimide, and the content of the cycloaliphatic polyimide with respect to the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide. Of 62 to 95% by mass.

Thus, the content of the cycloaliphatic polyimide is 62 to 95 mass% with respect to the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide. If the content of such a cycloaliphatic polyimide is less than the lower limit, the yellowness tends to be a high value and sufficiently high transparency cannot be obtained, while if it exceeds the upper limit, the heat resistance decreases. Tend to do. In addition, the content of the cycloaliphatic polyimide in such a polyimide alloy may be 65 to 95 mass% with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide, from the same viewpoint. It is more preferably 70 to 90% by mass. The content of the wholly aromatic polyimide is 38 to 5% by mass (preferably 35 to 5% by mass, more preferably 30 to 10% by mass) with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide. ).

Further, the polyimide alloy of the present invention, depending on the application, in addition to the cycloaliphatic polyimide and the wholly aromatic polyimide, for example, antioxidants, ultraviolet absorbers/hindered amine light stabilizers, nucleating agents/transparency Agent, inorganic filler (glass fiber, glass hollow sphere, talc, mica, alumina, titania, silica, etc.), heavy metal deactivator/filler-filled plastic additive, flame retardant, processability improver/lubricant/water dispersion type Stabilizers, permanent antistatic agents, toughness improvers, surfactants, carbon fibers and the like may be further contained as additional components. In this case, the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide contained in the polyimide alloy of the present invention is 50% by mass or more (more preferably 60% by mass or more, further preferably 70% by mass). % Or more, particularly preferably 80% by mass or more, and most preferably 85% by mass or more). Further, the preferred range also varies depending on the type of the additive component used, but in the case of further containing the additive component, from the viewpoint of further improving the effect obtained by the additive component, The total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide contained in the polyimide alloy is more preferably 60 to 95% by mass (more preferably 70 to 90% by mass). The polyimide alloy of the present invention is more preferably substantially composed of the cycloaliphatic polyimide and the wholly aromatic polyimide, from the viewpoint of more reflecting the characteristics of the polyimide itself in the alloy. In addition, the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide is more preferably 90% by mass or more (particularly preferably 95% by mass or more).

The polyimide alloy of the present invention preferably has a sufficiently high transparency when a film is formed, and has a total light transmittance of 80% or more (more preferably 85% or more, particularly preferably 87% or more). ) Is more preferable. Such total light transmittance can be determined by performing a measurement based on JIS K7361-1 (issued in 1997).

Furthermore, the polyimide alloy of the present invention preferably has a sufficiently high transparency when a film is formed, and therefore, the one having a yellowness index (YI) of 15 or less (more preferably 13 to 0) is preferable. More preferable. Such a yellowness index (YI) can be obtained by performing a measurement based on ASTM E313-05 (published in 2005).

The 1% weight loss temperature (Td 1%) of the polyimide alloy of the present invention is preferably 400° C. or higher, and 420 to 600° C., from the viewpoint of reflecting the high heat resistance of the wholly aromatic polyimide. Is more preferable. The 1% weight loss temperature is determined by measuring the temperature at which the weight of the sample used is reduced by 1% by gradually heating from room temperature (25°C) under a nitrogen gas atmosphere while flowing nitrogen gas. You can ask.

Further, such a polyimide alloy (composite material of polyimide molecules: polyimide resin composition) is excellent in heat resistance and transparency and can be used as a transparent material having heat resistance close to that of glass. The polyimide alloy can be suitably used for applications that are difficult to use from the viewpoint of transparency (for example, TFT substrate applications (LTPS, for polysilicon) and vehicle-mounted polyimide). In addition, such a polyimide alloy is, for example, a flexible transparent conductive film, a film for a flexible solar cell, a flexible printed wiring board, a flexible interposer for semiconductors, a flexible electronic device, a substrate for electronic paper, a substrate for organic EL, a transparent for a touch panel. It is particularly useful as a material for producing a conductive base material, a flexible circuit board, a process paper for a flexible circuit board, a base material for a flexible display, an organic EL lighting base material, an LED lighting base material and the like.

As a method for producing such a polyimide alloy of the present invention, a method for producing a polyimide alloy of the present invention described later can be preferably used. The polyimide alloy of the present invention has been described above. Next, the polyimide alloy precursor resin composition of the present invention will be described.

[Polyimide alloy precursor resin composition]
The polyimide alloy precursor resin composition of the present invention comprises a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure, and at least one diamine selected from the group consisting of aromatic diamines and aliphatic diamines. A cycloaliphatic polyamic acid that is a polyaddition product with a compound, and at least one cycloaliphatic polymer selected from the group consisting of a cycloaliphatic polyimide that is a ring-closing condensation product of the cycloaliphatic polyamic acid; and , Diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride, at least one aromatic tetra selected from the group consisting of A carboxylic dianhydride, and a wholly aromatic polyamic acid which is a polyaddition product of an aromatic diamine; and the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and Based on the weight of wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62. It is characterized by containing the cycloaliphatic polymer and the wholly aromatic polyamic acid in a proportion such that the content is about 95% by mass. Hereinafter, first, the cyclic aliphatic polymer and the wholly aromatic polyamic acid will be separately described.

<Cyclic aliphatic polymer>
Such a cycloaliphatic polymer is at least one polymer selected from the group consisting of the cycloaliphatic polyamic acid and the cycloaliphatic polyimide.

The cycloaliphatic polyamic acid that can be used as the cycloaliphatic polymer is selected from the group consisting of cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure, aromatic diamine and aliphatic diamine. It is a polyaddition product with at least one diamine compound selected. The "cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure", "aromatic diamine", "aliphatic diamine" and "diamine compound" referred to herein are the above-mentioned polyimide alloys of the present invention. Are the same as those described in (the preferred ones are also the same).

The cycloaliphatic polyamic acid (cycloaliphatic polyamic acid) is a reaction product obtained by subjecting the cycloaliphatic tetracarboxylic dianhydride and the diamine compound to an addition polymerization reaction (ring opening polyaddition reaction). is there. Such an addition polymerization reaction (ring-opening polyaddition reaction) uses a known method for producing a polyamic acid (for example, International Publication No. 2011, except that the cycloaliphatic tetracarboxylic dianhydride and the diamine compound are used). The method similar to the reaction conditions used in the method described in No. 099518) can be appropriately adopted to proceed. Thus, the cycloaliphatic polyamic acid, except for utilizing the cycloaliphatic tetracarboxylic dianhydride and the diamine compound, manufactured by appropriately adopting a known method for manufacturing polyamic acid (polyamic acid) can do.

Examples of the cycloaliphatic polyamic acid which is an addition polymer of the cycloaliphatic tetracarboxylic dianhydride and the diamine compound include, for example, the following general formula (3):

[X ¹ is a residue obtained by removing two acid anhydride groups from the above cycloaliphatic tetracarboxylic dianhydride (a tetravalent organic group: more preferably, the same " ¹ " as X ¹ in the above formula (I) The above is a tetravalent organic group having an aliphatic 6-membered ring structure”), and X ² is a residue obtained by removing two amino groups from the diamine compound (more preferably as R ¹⁰ in the above formula (X). It is an arylene group having 6 to 50 carbon atoms that can be selected, or an alkylene group that can be formed by removing two amino groups from the aliphatic diamine). ]
A polyamic acid having a repeating unit represented by

Moreover, as such a cycloaliphatic polyamic acid, those having an intrinsic viscosity [η] of 0.05 to 3.0 dL/g are preferable, and those of 0.1 to 2.0 dL/g are more preferable. If the intrinsic viscosity [η] is less than the lower limit, the resin tends to be brittle and the film tends to crack. On the other hand, if the intrinsic viscosity [η] exceeds the upper limit, handling becomes difficult and wrinkles occur in the film to form a uniform film. It tends to be difficult to obtain. In addition, in the present specification, a value measured as described below is adopted as the “intrinsic viscosity [η]”. That is, first, N,N-dimethylacetamide was used as a solvent, and the cycloaliphatic polyamic acid was dissolved in the N,N-dimethylacetamide at a concentration of 0.5 g/dL to prepare a measurement sample ( Solution). Next, the viscosity of the measurement sample is measured using a kinematic viscometer using the measurement sample under a temperature condition of 30° C., and the obtained value is adopted as the intrinsic viscosity [η]. As such a kinematic viscometer, an automatic viscosity measuring device (trade name “VMC-252”) manufactured by Rikyu Co., Ltd. is used.

The cycloaliphatic polyimide that can be used as the cycloaliphatic polymer is a ring-closing condensation product of the cycloaliphatic polyamic acid. As described above, the cycloaliphatic polyimide is obtained by subjecting the cycloaliphatic polyamic acid to ring-closing condensation (dehydration ring-closing: intramolecular condensation). Therefore, the cycloaliphatic polyimide is subjected to an addition polymerization reaction (ring opening polyaddition reaction) between the cycloaliphatic tetracarboxylic dianhydride and the diamine compound, and then a ring-closing condensation reaction (dehydration ring-closing reaction: intramolecular condensation). It can be said that it is obtained by a reaction), and it can be said that it is a polycondensation product of the cycloaliphatic tetracarboxylic dianhydride and the diamine compound. Thus, the cycloaliphatic polyimide that can be used as the cycloaliphatic polymer is the same as the "cycloaliphatic polyimide" described in the polyimide alloy of the present invention.

<Whole aromatic polyamic acid>
Such wholly aromatic polyamic acids include diphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA) and benzene-1,2,4,5-tetracarboxylic dianhydride (PMDA). ) A polyaddition product of at least one aromatic tetracarboxylic dianhydride selected from the group consisting of 1) and an aromatic diamine. The “aromatic diamine” mentioned here is the same as that described in the above-mentioned polyimide alloy of the present invention (the preferred one is also the same).

Further, such wholly aromatic polyamic acid (wholly aromatic polyamic acid) is an addition polymer of the aromatic tetracarboxylic dianhydride and the aromatic diamine. That is, the wholly aromatic polyamic acid is a reaction product obtained by subjecting the aromatic tetracarboxylic dianhydride (BPDA and/or PMDA) and the aromatic diamine to an addition polymerization reaction (ring opening polyaddition reaction). Is. Such an addition polymerization reaction (ring-opening polyaddition reaction) is a known method for producing a polyamic acid, except that the aromatic tetracarboxylic dianhydride (BPDA and/or PMDA) and the aromatic diamine are used. The same reaction conditions as those employed in 1 above can be appropriately adopted to proceed. As described above, the wholly aromatic polyamic acid is a known polyamic acid (polyamic acid) except that the aromatic tetracarboxylic dianhydride (BPDA and/or PMDA) and the aromatic diamine are used. It can be manufactured by appropriately adopting a method.

As the wholly aromatic polyamic acid, which is an addition polymerization product of such an aromatic tetracarboxylic dianhydride and the aromatic diamine, for example, the following general formula (4):

[X ³ is a residue (tetravalent organic group) obtained by removing two acid anhydride groups from BPDA or PMDA, and X ⁴ is a residue obtained by removing two amino groups from the aromatic diamine (more preferably, It is an arylene group having 6 to 50 carbon atoms that can be selected as R ¹⁰ in the above formula (X). ]
A polyamic acid having a repeating unit represented by Further, as such an aromatic polyamic acid, a commercially available product (for example, a product name “U-Varnish-S” manufactured by Ube Industries, Ltd.) can be preferably used.

<Polyimide alloy precursor resin composition>
The polyimide alloy precursor resin composition of the present invention comprises the cycloaliphatic polymer and the wholly aromatic polyamic acid, and the cycloaliphatic polymer (the cycloaliphatic polyamic acid and / or the cycloaliphatic Polyimide) obtained by heat-curing the cycloaliphatic polyimide (heat-cured product of the cycloaliphatic polymer) and the wholly aromatic polyimide obtained by heat-curing the wholly aromatic polyamic acid (all of the above). Based on the mass of the heat-cured product of an aromatic polyamic acid), the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the total aromatic polyimide is 62 to 95% by mass, and It contains a cycloaliphatic polymer and the wholly aromatic polyamic acid.

If the content of such a cycloaliphatic polymer is less than the lower limit, it tends to be difficult to obtain a sufficiently high transparency with a high yellowness value, while if it exceeds the upper limit, the heat resistance is high. Tends to decrease. Further, as the content of such a cycloaliphatic polymer, from the same viewpoint, the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the wholly aromatic polyamic acid are heated. Based on the mass of the wholly aromatic polyimide obtained when cured, the ratio of the content of the cycloaliphatic polyimide to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 65 to 95 mass% (amount ) Is preferable, and it is more preferable that the ratio (amount) is 70 to 90% by mass. In the polyimide alloy precursor resin composition, the wholly aromatic polyamic acid is a mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the wholly aromatic polyamic acid is heat-cured. Based on the mass of the wholly aromatic polyimide obtained in the case of, the content of the wholly aromatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 38 to 5% by mass (preferably 35 to 5). %, more preferably 30 to 10% by weight).

Such a polyimide alloy precursor resin composition may be a resin composition containing the cycloaliphatic polymer and the wholly aromatic polyamic acid (resin composition), and may be contained in a solvent to form a solution ( Resin solution: varnish). The polyimide alloy precursor resin composition of the present invention described below is preferable as the polyimide alloy precursor resin composition in a form further containing such a solvent. In addition, suitable conditions such as the solvent and the concentration thereof will be described later.

The method for preparing such a polyimide alloy precursor resin composition is not particularly limited, for example, a solution of the cycloaliphatic polymer (varnish), a solution of the wholly aromatic polyamic acid (varnish) A method of preparing by mixing, a solid matter of the cycloaliphatic polymer prepared in advance, a method of preparing a mixed solution by dissolving the solution of the wholly aromatic polyamic acid (varnish), In particular, it is preferable to adopt the step (A) of the method for producing a polyimide alloy of the present invention described below. In this way, when a solution-type polyimide alloy precursor resin composition is obtained as a mixture of varnishes, the solvent may be removed to obtain the polyimide alloy precursor resin composition as a solid state, and the application According to the above, it may be used in the form of a solution containing a solvent (mixed varnish). The polyimide alloy of the present invention can be prepared by heating and curing such a polyimide alloy precursor resin composition of the present invention.

Further, the polyimide alloy precursor resin composition of the present invention, depending on the application, together with the cycloaliphatic polymer and the wholly aromatic polyamic acid, for example, an antioxidant, an ultraviolet absorber/hindered amine light stabilizer, Nucleating agents/clarifying agents, inorganic fillers (glass fiber, glass hollow spheres, talc, mica, alumina, titania, silica, etc.), heavy metal deactivators/additives for filler-filled plastics, flame retardants, processability improvers/ A lubricant/water dispersion type stabilizer, a permanent antistatic agent, a toughness improver, a surfactant, carbon fiber and the like may be further contained as an additive component.

The polyimide alloy precursor resin composition of the present invention, when the polyimide alloy precursor resin composition is heat-cured to form a polyimide alloy, the cyclic aliphatic polyimide and the wholly aroma in the alloy (heated solid). The total amount (total amount) of the group polyimide is in the same range as the preferable range of the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide contained in the polyimide alloy of the present invention described above. It is preferable that the cycloaliphatic polymer and the wholly aromatic polyamic acid are contained in such a proportion. For example, when the polyimide alloy precursor resin composition of the present invention is heat-cured, the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide is 50% by mass or more (more preferably 60% by mass or more). , More preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 85% by mass or more (in some cases, preferably 60 to 95% by mass, more preferably 70 to 90% by mass). %), and the cycloaliphatic polymer and the wholly aromatic polyamic acid.

The polyimide alloy precursor resin composition of the present invention has been described above. Next, the polyimide alloy precursor resin solution of the present invention will be described.

[Polyimide alloy precursor resin solution]
The polyimide alloy precursor resin solution of the present invention is a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure, and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. At least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyamic acid, which is a polyaddition product thereof, and cycloaliphatic polyimide, which is a ring-closing condensation product of the cycloaliphatic polyamic acid; diphenyl- At least one aromatic tetracarboxylic dianhydride selected from the group consisting of 3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Mass of cycloaliphatic polyimide obtained by containing a wholly aromatic polyamic acid, which is a polyaddition product of an anhydride and an aromatic diamine; and a solvent; and curing the cycloaliphatic polymer by heating. And based on the weight of wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide. Is 62 to 95% by mass, and the cycloaliphatic polymer and the wholly aromatic polyamic acid are contained therein.

Such "cycloaliphatic polyamic acid" in the polyimide alloy precursor resin solution of the present invention, "cycloaliphatic polyimide", "cycloaliphatic polymer", "whole aromatic polyamic acid", respectively, the above-mentioned book The polyimide alloy of the present invention and the polyimide alloy precursor resin composition of the present invention described above are the same as those described above (the preferred ones are also the same). And, such a polyimide alloy precursor resin solution of the present invention can be said to be a solution-shaped polyimide alloy precursor resin composition of the present invention, and a suitable one of the above polyimide alloy precursor resin compositions of the present invention It can be said that this is an embodiment.

Further, the solvent used in the polyimide alloy precursor resin solution of the present invention is not particularly limited, and known solvents can be appropriately used, for example, paragraph [0175] and paragraph [0133] of International Publication No. 2018/066522. ] The solvent etc. which are described in [0134] can be utilized suitably. Examples of such a solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, propylene carbonate, tetramethylurea and 1,3-dimethyl. Aprotic polar solvent such as -2-imidazolidinone, hexamethylphosphoric triamide, pyridine; Phenolic solvent such as m-cresol, xylenol, phenol, halogenated phenol; Tetrahydrofuran, dioxane, cellosolve, glyme, etc. Ether solvents; aromatic solvents such as benzene, toluene and xylene; ketone solvents such as cyclopentanone and cyclohexanone; nitrile solvents such as acetonitrile and benzonitrile. Such organic solvents may be used alone or in combination of two or more.

Furthermore, in the polyimide alloy precursor resin solution of the present invention, the total aroma obtained when the cycloaliphatic polymer is heat-cured and the mass of the cycloaliphatic polyimide and the wholly aromatic polyamic acid is heat-cured. Based on the mass of the group polyimide, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62 to 95 mass% (preferably 65 to 95 mass%, more preferably 70). To 90% by mass), the cycloaliphatic polymer and the wholly aromatic polyamic acid are contained. The content of such a cycloaliphatic polyimide is the same as that described in the above-mentioned polyimide alloy precursor resin composition of the present invention.

The total amount (total amount) of the cycloaliphatic polymer and the wholly aromatic polyamic acid contained in such a polyimide alloy precursor resin solution is not particularly limited, but is preferably 1 to 80% by mass. It is more preferable that the content is ˜50 mass %. If the content is out of the above range, it tends to be difficult to use as a varnish for producing a film of a polyimide alloy. In addition, such a polyimide alloy precursor resin solution can be suitably used as a resin solution (varnish) for producing the polyimide alloy of the present invention, and is suitably used for producing polyimide alloys of various shapes. it can. For example, a film-shaped polyimide alloy can be easily manufactured by applying such a polyimide alloy precursor resin solution on various substrates, imidizing it and curing it.

The method for preparing the polyimide alloy precursor resin solution of the present invention is not particularly limited, for example, a solution of the cycloaliphatic polymer (varnish), a solution of the wholly aromatic polyamic acid (varnish) A method of preparing by mixing, a solid matter of the cycloaliphatic polymer prepared in advance, a method of preparing a mixed solution by dissolving the solution of the wholly aromatic polyamic acid (varnish), Among these, it is preferable to adopt the step (A) of the method for producing a polyimide alloy of the present invention described below. The polyimide alloy of the present invention can be prepared by heating and curing such a polyimide alloy precursor resin solution of the present invention.

In addition, such a polyimide precursor resin solution has an antioxidant, an ultraviolet absorber, a hindered amine-based light stabilizer, a nucleating agent/clearing agent, an inorganic filler (glass fiber, glass hollow) depending on the purpose of use. Sphere, talc, mica, alumina, titania, silica, etc.), heavy metal deactivator/filler-filled plastic additive, flame retardant, processability improver/lubricant/water dispersion stabilizer, permanent antistatic agent, toughness improvement Agents, surfactants, carbon fibers and the like may be further contained as additional components.

The polyimide alloy precursor resin solution of the present invention, when the polyimide alloy precursor resin solution is heat-cured to form a polyimide alloy, the cyclic aliphatic polyimide and the wholly aromatic polyimide in the alloy (heated solid) The total amount (total amount) is a ratio such that the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide contained in the above-described polyimide alloy of the present invention is in the same range as the preferable range. It is preferable that the cyclic aliphatic polymer and the wholly aromatic polyamic acid are contained. For example, when the polyimide alloy precursor resin solution is heat-cured, the total amount (total amount) of the cycloaliphatic polyimide and the wholly aromatic polyimide is 50% by mass or more (more preferably 60% by mass or more, and further preferably Is 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 85% by mass or more (in some cases, preferably 60 to 95% by mass, more preferably 70 to 90% by mass). It is preferable to contain the cycloaliphatic polymer and the wholly aromatic polyamic acid.

The polyimide alloy precursor resin solution of the present invention has been described above. Next, the method for producing the polyimide alloy of the present invention will be described.

[Method for producing polyimide alloy]
The manufacturing method of the polyimide alloy of the present invention,
Cycloaliphatic polyamic acid that is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride containing an aliphatic 6-membered ring and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines And a solution of at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid,
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Acid dianhydride, a solution of wholly aromatic polyamic acid that is a polyaddition product of aromatic diamine, the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the total aroma. Based on the mass of wholly aromatic polyimide obtained when the group polyamic acid is heat-cured, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62 to 95. A step (A) of obtaining a polyimide alloy precursor resin solution by mixing in a proportion such that the mass% becomes
By heating and curing the polyimide alloy precursor resin solution,
A cycloaliphatic polyimide which is a polycondensate of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. And at least one fragrance selected from the group consisting of diphenyl-3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Group tetracarboxylic dianhydride and wholly aromatic polyimide which is a polycondensation product of aromatic diamine; and containing the cyclic aliphatic polyimide and the cyclic aliphatic polyimide with respect to the total amount of the wholly aromatic polyimide. A step (B) for obtaining a polyimide alloy having an amount of 62 to 95% by mass,
The method is characterized by including. Hereinafter, the steps (A) and (B) will be described separately.

<Process (A)>
Step (A) is a solution of at least one of the cycloaliphatic polymer selected from the group consisting of the cycloaliphatic polyamic acid and the cycloaliphatic polyimide, and a solution of the wholly aromatic polyamic acid, It is a step of obtaining a polyimide alloy precursor resin solution by mixing the cycloaliphatic polymer and the wholly aromatic polyamic acid so that the content of the cycloaliphatic polymer is 62 to 95% by mass with respect to the total amount of the polyaromatic polyamic acid. ..

The “cycloaliphatic polyamic acid”, “cycloaliphatic polyimide”, “cycloaliphatic polymer”, and “wholly aromatic polyamic acid” used in such a step are respectively the above-described polyimide alloy of the present invention and the above. Is the same as that described in the polyimide alloy precursor resin composition of the present invention (the preferred one is also the same). Hereinafter, the solution of the cycloaliphatic polymer and the solution of the wholly aromatic polyamic acid used in the step (A) will be described first.

The cycloaliphatic polymer solution used in the step (A) preferably has a cycloaliphatic polymer content of 1 to 80% by mass, more preferably 5 to 50% by mass. If the content of such a cycloaliphatic polymer is less than the lower limit, it takes a long time to dry after solution coating, or the obtained coating film tends to be thin, while if it exceeds the upper limit, the polymer There is a tendency that the viscosity of the solution is too high and handling becomes difficult, or the obtained coating film becomes too thick and wrinkles easily occur in the coating film. It should be noted that such a solution of a cycloaliphatic polymer may appropriately contain other components such as the above-mentioned additional components and reaction accelerators depending on the use of the polymer alloy.

The method for preparing a solution of such a cycloaliphatic polymer is not particularly limited, and a method of preparing the cycloaliphatic polyamic acid and/or the cycloaliphatic polyimide in advance and dissolving it in a solvent is used. May be adopted, or by reacting the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound in the presence of a solvent, the cycloaliphatic polyamic acid and / or You may employ the method (I) which prepares the said cycloaliphatic polyimide and obtains the obtained reaction liquid as it is as a solution of the said cycloaliphatic polymer. Hereinafter, the method (I) will be briefly described.

In such a method (I), the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure is reacted with the diamine compound in the presence of a solvent to produce the cycloaliphatic polyamic acid and/or Alternatively, it is a method of preparing the cycloaliphatic polyimide and obtaining the reaction solution as it is as a solution of the cycloaliphatic polymer.

The solvent used in such a method (I) is not particularly limited, and a known solvent that can be used in the production of polyimide can be appropriately used, and the solvent described in the polyimide alloy precursor resin solution of the present invention described above. Can be used as appropriate.

In the method (I), the cyclic aliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound are reacted (addition polymerization reaction) in the presence of a solvent, and The method for preparing the cycloaliphatic polyamic acid is not particularly limited, and a known polyamic acid except that a cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure and the diamine compound are used. It can be prepared by appropriately employing the same reaction conditions as used in the method for producing (polyamic acid) (for example, the method described in WO 2011/099518). In this way, the cycloaliphatic polyamic acid can be prepared in the solvent.

Furthermore, in such a method (I), the cyclic aliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure is reacted with the diamine compound in the presence of a solvent to form the cyclic aliphatic polyimide. The method for preparing is not particularly limited, and as described above, after preparing the cycloaliphatic polyamic acid in a solvent, imidization is performed on the cycloaliphatic polyamic acid in a solvent, and the cycloaliphatic. It may be prepared by ring-closing condensation of a polyamic acid. The imidization method is not particularly limited, and a known method capable of imidizing (ring-closing condensation) a polyamic acid (polyamic acid) (for example, paragraph [0134] of International Publication No. 2011/099518). ] To [0156], conditions described in paragraphs [0201] to [0224] of International Publication No. 2018/25188) and the like can be appropriately adopted.

In addition, in such a method (I), as a method for preparing the cycloaliphatic polyimide in the presence of a solvent, for example, a solvent and the cycloaliphatic tetracarboxylic dianhydride having the aliphatic 6-membered ring structure are included. Of the polyamic acid, followed by imide by preparing a mixed liquid containing the compound, the diamine compound, and the reaction accelerator, and heating the mixed liquid to 100 to 250° C. (more preferably 120 to 250° C.). You may employ the method of preparing the said cycloaliphatic polyimide in a solvent, carrying out the process of compounding substantially simultaneously. Such a reaction accelerator is not particularly limited, but examples thereof include imidazole, methylimidazole, 1-methylimidazole, 2-methylimidazole, dimethylimidazole, 1,2-dimethylimidazole, trimethylimidazole, tetramethylimidazole, tert- Imidazole compounds such as butylimidazole, phenylimidazole, 2-phenylimidazole, benzylimidazole, benzimidazole, ethylimidazole, propylimidazole, butylimidazole, fluoroimidazole, chloroimidazole, bromoimidazole; 2-amino-3-(1H-imidazole -4-yl)propionic acid, β-phenyl-1H-imidazole-1-propionic acid, β-(4-methoxyphenyl)-1H-imidazole-1-propionic acid, β-(4-methylphenyl)-1H- Histidine compounds such as imidazole-1-propionic acid, β-alanyl-L-histidine, L-histidine, Nt-butoxycarbonyl-L-histidine; imidazole peptide compounds such as carnosine, anserine, valenin and homocarnosine; A tertiary amine compound such as trimethylamine, triethylamine, N,N-diisopropylethylamine, tetramethylethylenediamine, pyridine; or the like can be preferably used.

Thus, by preparing the cycloaliphatic polyamic acid and/or the precycloaliphatic polyimide in the solvent, the reaction solution can be directly used as a solution of the cycloaliphatic polymer.

As the wholly aromatic polyamic acid solution used in the step (A), the content of the wholly aromatic polyamic acid is preferably 1 to 80% by mass, more preferably 5 to 50% by mass. If the content of such wholly aromatic polyamic acid is less than the lower limit, it may take a long time to dry the solution after application of the solution, or the obtained coating film tends to be thin, while if it exceeds the upper limit of the polymer. There is a tendency that the viscosity of the solution is too high and handling becomes difficult, or the obtained coating film becomes too thick and wrinkles easily occur in the coating film. It should be noted that such wholly aromatic polyamic acid may appropriately contain other components such as the above-mentioned additional components depending on the use of the polymer alloy.

A method for preparing a solution of such wholly aromatic polyamic acid is not particularly limited, and a method of preparing the wholly aromatic polyamic acid in advance and preparing it by dissolving it in a solvent may be adopted, or In a solvent, at least one selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride. Aromatic tetracarboxylic dianhydride and aromatic diamine are reacted (polyaddition reaction) to prepare a wholly aromatic polyamic acid, and the obtained reaction solution is directly obtained as a solution of the wholly aromatic polyamic acid. A method may be adopted. Incidentally, such a solvent is not particularly limited, a known solvent that can be used in the production of polyimide can be appropriately used, and the solvent described in the above-described polyimide alloy precursor resin solution of the present invention can be appropriately used. can do. The method for preparing such wholly aromatic polyamic acid is not particularly limited, except that the aromatic tetracarboxylic dianhydride and the aromatic diamine are used, a known polyamic acid (polyamic acid). It is possible to employ a method of preparing by appropriately adopting the same reaction conditions as used in the production method of.

Further, the solution of wholly aromatic polyamic acid used in the step (A) is a wholly aromatic compound which is a polyaddition product (addition polymer: reaction product) of the aromatic tetracarboxylic dianhydride and the aromatic diamine. You may use the commercial item of the solution of polyamic acid (For example, the brand name "U-Varnish-S" by Ube Industries, Ltd.).

Furthermore, in such a step (A), a cycloaliphatic polymer obtained by heat-curing the cycloaliphatic polymer solution and the wholly aromatic polyamic acid solution Based on the mass of the polyimide and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide. The amount is 62 to 95% by mass (preferably 65 to 95% by mass, more preferably 70 to 90% by mass). If the content of such a cycloaliphatic polyimide is less than the lower limit, the yellowness tends to be a high value and sufficiently high transparency cannot be obtained, while if it exceeds the upper limit, the heat resistance decreases. Tend to do.

In the step (A), when the solution of the cycloaliphatic polymer and the solution of the wholly aromatic polyamic acid are mixed, other components (such as the above-mentioned additional components) are added to any of the solutions. If included, the total amount of the cycloaliphatic polymer and the wholly aromatic polyamic acid contained in the solid content (solid matter obtained after removing the solvent) in the resulting polyimide alloy precursor resin solution (total amount) ) Is preferably 50% by mass or more, more preferably 60 to 95% by mass, and further preferably 70 to 90% by mass.

By mixing the solution of the cycloaliphatic polymer and the solution of the wholly aromatic polyamic acid in this manner, a polyimide alloy precursor resin solution can be obtained. By preparing the polyimide alloy precursor resin solution in this way, it is possible to make it the same as the above-mentioned polyimide alloy precursor resin solution of the present invention. Therefore, the preferable range of the total amount of the cycloaliphatic polymer and the wholly aromatic polyamic acid contained in the polyimide alloy precursor resin solution obtained in the step (A) is as follows. The range may be the same as the preferable range of the total amount of the cycloaliphatic polymer and the wholly aromatic polyamic acid contained in the solution.

<Process (B)>
The step (B) is a step of obtaining the polyimide alloy by heating and curing the polyimide alloy precursor resin solution.

The method for heating and curing the polyimide alloy precursor resin solution is not particularly limited, and for example, polyamic acid (the wholly aromatic polyamic acid and/or the polyamic acid that is a component contained in the polyimide alloy precursor resin solution). The cycloaliphatic polyamic acid) may be imidized in a solution and then heat-cured to obtain a polyimide alloy as a cured product. Further, a method may be employed in which the polyimide alloy precursor resin solution is contained. A method (II) for obtaining a polyimide alloy as a cured product (II) is preferably adopted, in which the component polyamic acid (the wholly aromatic polyamic acid and/or the cycloaliphatic polyamic acid) is cured while being imidized by heating. May be. Hereinafter, a suitable method (II) as a method for heating and curing such a polyimide alloy precursor resin solution will be briefly described.

When such method (II) is adopted, a solid material (resin composition) is obtained by evaporating and removing the solvent from the polyimide alloy precursor resin solution, and then the polyamic acid in the solid material is heated. Therefore, it is preferable to employ a method of curing while imidizing. The method for obtaining such a solid material (resin composition) is not particularly limited, but, for example, using the polyimide alloy precursor resin solution as a coating solution, coating it on a substrate A method of evaporating and removing the solvent after obtaining the coating film by the method and the like can be mentioned. After the coating film is obtained in this way, a solvent can be evaporated to form a film-like solid matter, which makes it possible to more efficiently prepare a film-like polyimide alloy. Note that such a coating method is not particularly limited, and a known method (spin coating method, bar coating method, dip coating method, die coating method, gravure coating method, etc.) can be appropriately used. The method for evaporating and removing the solvent is also not particularly limited, and a known method (temperature condition, atmosphere condition, etc.) can be appropriately adopted, and for example, 0 to 180° C. (more A preferable method is to gently heat at 30 to 150° C.) to evaporate and remove the solvent.

In addition, the method of curing while imidizing by heating in the method (II) is not particularly limited, and a known method capable of imidizing and curing a polyamic acid to cure (for example, International Publication No. The method described in 2011/099518, the method described in International Publication 2018/25188, etc.) can be appropriately adopted. Further, from the viewpoint of forming a sufficiently cured polyimide alloy while sufficiently imidizing by such heating, heating at a temperature of 60 to 500° C. (more preferably 70 to 450° C.) during such heating ( Firing) is preferable. The heating time is not particularly limited, and may be 0.1 to 10 hours depending on the type of monomer used.

In this way, by heating and curing the polyimide alloy precursor resin solution, the polyamic acid (the cyclic aliphatic polyamic acid and/or the wholly aroma), which is a component contained in the polyimide alloy precursor resin solution. (Polycyclic acid of group) is subjected to ring-closing condensation to form a polyimide composed of the cycloaliphatic polyimide (ring-closing condensation product of the cycloaliphatic polyamic acid) and the wholly aromatic polyimide (ring-closing condensation product of the wholly aromatic polyamic acid). An alloy can be obtained, and in the thus obtained polyimide alloy, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass. ..

Thus, by heating and curing the polyimide alloy precursor resin solution, a cyclic aliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure, and selected from the group consisting of aromatic diamines and aliphatic diamines. A cycloaliphatic polyimide which is a polycondensate with at least one diamine compound, and diphenyl-3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5- A wholly aromatic polyimide which is a polycondensation product of at least one aromatic tetracarboxylic acid dianhydride selected from the group consisting of tetracarboxylic acid dianhydride and an aromatic diamine; It is possible to obtain a polyimide alloy in which the content of the cycloaliphatic polyimide with respect to the total amount of the group polyimide and the wholly aromatic polyimide is 62 to 95% by mass. The polyimide alloy thus obtained is the same as that described as the polyimide alloy of the present invention. Therefore, the method for producing the polyimide alloy of the present invention can be suitably used as the method for producing the polyimide alloy of the present invention.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

(Example 1)
<Preparation Step of Cyclic Aliphatic Polyamic Acid Varnish (A)>
First, a 100 mL three-necked flask was heated with a heat gun to be sufficiently dried. Then, the atmosphere gas in the three-necked flask that had been sufficiently dried was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, the following structural formula (XI):

Norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''- which is a cycloaliphatic tetracarboxylic dianhydride represented by Tetracarboxylic dianhydride (abbreviation "CpODA", manufactured by JXTG Energy Co., Ltd.) 3.8438 g (10 mmol) and 4,4'-diaminobenzanilide (abbreviation "DABAN": manufactured by Nippon Pure Chemical) 2.2726 g (10 mmol) ) And tetramethylurea (abbreviation “TMU”) 27.864 g are added, and the reaction is carried out at room temperature (25° C.) for 24 hours to give a cycloaliphatic polyamic acid (CpODA and solid content concentration of 18% by mass). A resin solution of (addition polymer of DABAN) (cycloaliphatic polyamic acid varnish (A)) was obtained.

The cycloaliphatic polyamic acid varnish (A) thus obtained was partially used to sample the cycloaliphatic polyamic acid (addition polymerization product of CpODA and DABAN) from the varnish (A), and the varnish (A) was sampled as described above. The intrinsic viscosity [η] of the cycloaliphatic polyamic acid (addition polymer of CpODA and DABAN) was 0.904 dL/g.

Further, the obtained cycloaliphatic polyamic acid varnish (A) was subjected to GPC analysis, and the obtained results (chromatogram) are shown in FIG. In addition, such GPC analysis is performed by gel permeation chromatography measuring device (GPC, manufactured by Tosoh Corporation, trade name: HLC-8320GPC/four columns: manufactured by Tosoh Corporation, trade name: TSK gel SuperAW 4000, 3000, 2500). , SuperH-RC, solvent: N,N-dimethylacetamide (DMAc)).

<Preparation of wholly aromatic polyamic acid varnish (B)>
As a varnish of wholly aromatic polyamic acid, a commercially available varnish (trade name “U-varnish-S” manufactured by Ube Industries, Ltd., solvent: N-methyl-2-pyrrolidone (NMP), solid content concentration: 18% by mass) , Type of wholly aromatic polyamic acid: diphenyl-3,3′,4,4′-tetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PPD) addition polymer) were prepared. Thus, as a resin solution (whole aromatic aromatic polyamic acid varnish (B)) of wholly aromatic polyamic acid (addition polymerization product of BPDA and PPD) having a solid content concentration of 18% by mass, a commercially available product (Ube Industries Ltd.) The product name “U-Varnish-S” manufactured by the company was used. In addition, for such wholly aromatic polyamic acid varnish (B), a gel permeation chromatography measuring device (GPC, manufactured by Tosoh Corporation, trade name: HLC-8320GPC/four columns: manufactured by Tosoh Corporation, GPC analysis was carried out using a trade name: TSK gel SuperAW4000, 3000, 2500, SuperH-RC, solvent: N,N-dimethylacetamide (DMAc). The obtained results (chromatogram) are shown in FIG.

<Preparation process of mixed varnish (C) (polyimide alloy precursor resin solution)>
After thoroughly drying the 50 ml screw tube, the gas in the screw tube was replaced with nitrogen to create a nitrogen atmosphere. Next, in a nitrogen atmosphere, 4 g of the wholly aromatic polyamic acid varnish (B) having a solid content of 18 mass% was added to the screw tube, and then the cyclic aliphatic compound having a solid content of 18 mass% was added. After 6 g of polyamic acid varnish (A) was added, 2 g of TMU was added, and the mixture was stirred for 2 hours at room temperature (25° C.) with a magnetic stirrer to give a cyclic polymer which is an addition polymer of CpODA and DABAN. A polyimide alloy precursor resin solution (mixed varnish (C)) containing an aliphatic polyamic acid, a wholly aromatic polyamic acid that is an addition polymer of BPDA and PPD, and a solvent (TMU and NMP) was obtained. Thus, the mass ratio of the cycloaliphatic polyamic acid varnish (A) to the wholly aromatic polyamic acid varnish (B) ([varnish (A)]:[varnish (B)]) is 6:4. The mixture was mixed as described above to obtain a mixed varnish (C).

In the obtained mixed varnish (C), the mass ratio of the cycloaliphatic polyamic acid and the wholly aromatic polyamic acid ([cycloaliphatic polyamic acid]:[wholly aromatic polyamic acid]) was 60: It became 40. The mixed varnish (C) has a mass of cycloaliphatic polyimide obtained when the cycloaliphatic polyamic acid is heat-cured, and a total amount obtained when the wholly aromatic polyamic acid is heat-cured. By calculating the mass of the aromatic polyimide and calculating the ratio (content) of the mass of the cycloaliphatic polyimide to the total mass of the cycloaliphatic polyimide and the wholly aromatic polyimide, it becomes 70.2 mass %. ..

Further, for the mixed varnish (C), a gel permeation chromatography measuring device (GPC, manufactured by Tosoh Corporation, trade name: HLC-8320GPC/four columns: manufactured by Tosoh Corporation, trade name: TSK gel SuperAW4000, GPC analysis was performed using 3000, 2500, SuperH-RC, solvent: N,N-dimethylacetamide (DMAc). The obtained results (chromatogram) are shown in FIG.

<Preparation process of film-shaped polyimide alloy>
First, non-alkali glass (trade name "Eagle XG" manufactured by Corning, length: 100 mm, width 100 m, thickness 0.7 mm) was prepared as a glass substrate. Next, the mixed varnish (C) obtained as described above was spin-coated on the surface of the glass substrate so that the thickness of the coating film after heat curing was 10 μm, and applied on the glass substrate. A film was formed. Then, the glass substrate on which the coating film was formed was placed on a hot plate at 70° C. and allowed to stand for 0.5 hour to evaporate and remove the solvent from the coating film (solvent removal treatment). After performing such a solvent removal treatment, the glass substrate on which the coating film was formed was placed in a low oxygen clean oven SCO-11H-BL manufactured by Espec Co., Ltd., and under a nitrogen atmosphere (oxygen concentration <10 ppm), 30 After standing for 0.5 hours at a temperature of 80°C, heat at a temperature of 80°C for 0.5 hours, heat at a temperature of 300°C for 30 minutes, and further at a temperature of 400°C (final heating temperature). After heating for 30 minutes to cure the coating film, it was cooled to 80° C. in a nitrogen atmosphere to form a thin film of polyimide alloy on the glass substrate.

Next, the glass substrate on which the thin film (film) of the polyimide alloy thus obtained is formed is immersed in hot water at 90° C., and the film of the polyimide alloy is peeled from the glass substrate to obtain a film ( A 100 mm long, 100 mm wide, 10 μm thick film-like polyimide alloy was obtained.

(Examples 2 to 4)
When preparing the mixed varnish (polyimide alloy precursor resin solution), the mass ratio of the cycloaliphatic polyamic acid varnish (A) and the wholly aromatic polyamic acid varnish (B) ([varnish (A)]:[varnish ( B)]) is 7:3 (Example 2), 8:2 (Example 3) and 9:1 (Example 4), respectively, so that the cyclic aliphatic polyamic acid varnish (A) is A polyimide alloy was obtained in the same manner as in Example 1 except that the amount used and the amount used of the wholly aromatic polyamic acid varnish (B) were changed.

(Comparative Example 1)
A film was obtained by performing the same steps as the “step of preparing a film-shaped polyimide alloy” adopted in Example 1 except that the wholly aromatic polyamic acid varnish (B) was used instead of the mixed varnish (C). A wholly aromatic polyimide was obtained. In this way, in Comparative Example 1, the commercially available varnish “U-Varnish-S” manufactured by Ube Industries, Ltd. was used alone, and the film-shaped wholly aromatic polyimide (wholly aromatic polyimide) was used. Content: 100% by mass) was prepared.

(Comparative Examples 2 to 6)
When preparing the mixed varnish, the mass ratio of the cyclic aliphatic polyamic acid varnish (A) and the wholly aromatic polyamic acid varnish (B) ([varnish (A)]:[varnish (B)]) is 1:9 (Comparative Example 2), 2:8 (Comparative Example 3), 3:7 (Comparative Example 4), 4:6 (Comparative Example 5), and 5:5 (Comparative Example 6). A polyimide alloy was obtained in the same manner as in Example 1 except that the amount of the cyclic aliphatic polyamic acid varnish (A) and the amount of the wholly aromatic polyamic acid varnish (B) were changed.

(Comparative Example 7)
A film-like film was prepared by using the same steps as in the “preparation step for a film-like polyimide alloy” adopted in Example 1 except that the cycloaliphatic polyamic acid varnish (A) was used instead of the mixed varnish (C). To obtain a cycloaliphatic polyimide. Thus, in Comparative Example 7, the cyclic aliphatic polyamic acid varnish (A) was used alone to prepare a film-shaped cyclic aliphatic polyimide (content of the cyclic aliphatic polyimide: 100% by mass).

(Comparative Example 8)
Instead of the mixed varnish (C), the "film-like polyimide used in Example 1 was used except that the polyamic acid varnish (D) obtained by the "preparation step of the polyamic acid varnish (D)" described below was used. A film-shaped polyimide was obtained by adopting the same process as the “alloy preparation process”.

<Preparation process of polyamic acid varnish (D)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, 0.5682 g (2.5 mmol) of DABAN, 0.9610 g (2.5 mmol) of CpODA, and 6.97 g of TMU were added to the three-necked flask, and immediately after that, the solid content concentration was 18% by mass. 2.1248 g of a group-type polyamic acid varnish (B) (trade name "U-Varnish-S" manufactured by Ube Industries, Ltd.) was added and reacted at room temperature (25°C) for 24 hours to give a solid content concentration of 18 mass. % Resin solution (polyamic acid varnish (D)) was obtained.

The polyamic acid varnish (D) thus obtained was partially used to isolate the polyamic acid from the varnish (D), and the intrinsic viscosity [η] was measured as described above. [Η] was 0.694 dL/g.

Further, for the obtained polyamic acid varnish (D), a gel permeation chromatography measuring device (GPC, manufactured by Tosoh Corporation, trade name: HLC-8320GPC/four columns: manufactured by Tosoh Corporation, trade name: TSK) GPC analysis was carried out using gel SuperAW4000, 3000, 2500, SuperH-RC, solvent: N,N-dimethylacetamide (DMAc)). The obtained results (chromatogram) are shown in FIG.

Here, from the results shown in FIGS. 1 to 4, first, from the peak position of the chromatogram shown in FIG. 3 and the peak position of the chromatogram shown in FIGS. It can be seen that the compound was obtained by mixing the group polyamic acid and the wholly aromatic polyamic acid, whereas the peak of the chromatogram shown in FIG. 4 is one large peak, The polyamic acid varnish (D) is obtained by reacting CpODA and DABAN with a terminal functional group of a wholly aromatic polyamic acid (a component in the varnish (B)), which is an addition polymer of BPDA and PPD, to react with BPDA and PPD. It is considered that a block-structured polyamic acid containing a repeating unit formed by the reaction of 1) and a repeating unit formed by the reaction of CpODA and DABAN is formed. That is, from the results shown in FIGS. 1 to 4, the polyamic acid varnish (D) is a polyamic acid containing a repeating unit derived from CpODA and DABAN and a repeating unit derived from BPDA and PPD (whole aromatic aromatic polyamic acid). (BPDA/PPD), CpODA, and DABAN reaction product).

(Comparative Example 9)
In place of the mixed varnish (C), the "film-like polyimide used in Example 1 was used except that the polyamic acid varnish (E) obtained by the "preparation step of the polyamic acid varnish (E)" described below was used. A film-shaped polyimide was obtained by adopting the same process as the “alloy preparation process”.

<Preparation process of polyamic acid varnish (E)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, 0.5884 g (2 mmol) of BPDA (manufactured by JFE Chemical), 0.2163 g (2 mmol) of PPD (trade name "Paramine" manufactured by Daishin Kasei Co., Ltd.), and 1.8180 g of DABAN ( 8 mmol), 3.0750 g (8 mmol) of CpODA, and 25.96 g of a mixed solvent having a mass ratio of NMP and TMU (NMP:TMU) of 2:8, and reacted at room temperature (25° C.) for 24 hours. Then, a resin solution (polyamic acid varnish (E)) having a solid content concentration of 18 mass% was obtained.

The polyamic acid varnish (E) thus obtained was partially used to sample the polyamic acid from the varnish (E), and the intrinsic viscosity [η] was measured as described above. [Η] was 0.883 dL/g.

The resulting polyamic acid varnish (E) was prepared from its preparation process, including repeating units derived from CpODA and DABAN, repeating units derived from CpODA and PPD, repeating units derived from BPDA and DABAN, and BPDA and PPD. It is obvious that it is a varnish of polyamic acid containing a repeating unit derived from.

[Characteristic Evaluation of Polymers Obtained in Examples 1 to 4 and Comparative Examples 1 to 9]
<Measurement of total light transmittance and yellowness index (YI)>
The total light transmittance (unit: %) and the yellowness index (YI) were measured using the film-shaped polymer (polyimide alloy or polyimide) obtained in each Example etc. as it was as a sample for measurement. When measuring the light transmittance, a product name "Hazemeter NDH-5000" manufactured by Nippon Denshoku Industries Co., Ltd. is used as a measuring device, while, when measuring the yellowness, a product manufactured by Nippon Denshoku Industries Co., Ltd. is used as a measuring device. The measurement was performed using the name “Spectrocolorimeter SD6000”. The total light transmittance is determined by measuring in accordance with JIS K7361-1 (issued in 1997), and the yellowness (YI) is measured in accordance with ASTM E313-05 (issued in 2005). I asked. The results obtained are shown in Table 1.

<Measurement of 1% weight loss temperature (Td1%)>
The 1% weight loss temperature (Td1%) of the polymer (polyimide alloy or polyimide) obtained in each example, etc., was 10 mg from the polyimide alloy or polyimide (film shape) obtained in each example. Prepare and use a thermogravimetric analyzer ("TG/DTA220" manufactured by SII Nano Technology Co., Ltd.) to raise the temperature from room temperature (25°C) to 30°C while flowing nitrogen gas, and then set the scanning temperature. It was determined by setting the temperature from 30° C. to 550° C., gradually heating the sample at a temperature rising rate of 10° C./min, and measuring the temperature at which the weight of the sample used decreased by 1%. The results obtained are shown in Table 1.

<Measurement of tensile strength>
The tensile strength (unit: MPa) of the polymer (polyimide alloy or polyimide) obtained in each example or the like was measured as follows. That is, first, an SD type lever type sample cutter (cutter manufactured by Dumbbell Co., Ltd. (model SDL-200)) is provided with a trade name “Super Dumbbell Cutter (mold: SDMK-1000-D, JIS K7139) manufactured by Dumbbell Co., Ltd. (According to the A22 standard issued in 2009)” is used to cut each polyimide alloy film or each polyimide film into a total length: 75 mm, a distance between tab portions: 57 mm, a length of a parallel portion. Size: 30 mm, shoulder radius: 30 mm, end width: 10 mm, central parallel part width: 5 mm, thickness: 10 μm. Each film was cut into a dumbbell shape. A test piece (which complies with the standard of JIS K7139 type A22 (scaled test piece) except that the thickness was 10 μm) was prepared and used as a sample for measurement. Then, using an electromechanical universal material testing machine (model “5943” manufactured by INSTRON), the width of the gripping portion of the sample (dumbbell-shaped test piece) for measurement was 57 mm, and the width of the gripping portion was 10 mm ( Then, the tensile strength was obtained by conducting a tensile test in which the measurement sample was pulled under the conditions of load cell: 1.0 kN and test speed: 5 mm/min. In addition, such a test was a test based on JIS K7162 (issued in 1994). The results obtained are shown in Table 1.

First, as is clear from the composition of the varnish shown in Table 1, the polyimide alloys obtained in Examples 1 to 4 are cycloaliphatic polyimides derived from cycloaliphatic polyamic acid, which is an addition polymer of CpODA and DABAN. (CpODA/DABAN) and wholly aromatic polyimide (BPDA/PPD) derived from wholly aromatic polyamic acid, which is an addition polymer of BPDA and PPD, and the content of the cycloaliphatic polyimide with respect to the total amount thereof. The respective (mass ratios) were calculated to be 70.2% by mass (Example 1), 78.6% by mass (Example 2), 86.3% by mass (Example 3) and 93.4% by mass (Example). It turns out that it becomes 4). In Comparative Examples 1 to 7, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide (CpODA/DABAN) and the wholly aromatic polyimide (BPDA/PPD) was determined from the composition of the varnish. 0% by mass (Comparative Example 1), 14.9% by mass (Comparative Example 2), 28.2% by mass (Comparative Example 3), 40.2% by mass (Comparative Example 4), 51.2% by mass (Comparative Example) 5), 61.1 mass% (Comparative Example 6) and 100 mass% (Comparative Example 7).

Further, as is clear from the results shown in Table 1, the polyimide alloys obtained in Examples 1 to 4 all had Td1% of 488° C. or higher. In this regard, considering that the Td1% of the cycloaliphatic polyimide obtained in Comparative Example 7 which is a heat-cured product of the varnish (A) is 479° C., the cycloaliphatic polyimide is obtained by using the polyimide alloy. It was confirmed that Td1% was higher than that when used alone (Comparative Example 7).

Further, the polyimide alloys obtained in Examples 1 to 4 all have a total light transmittance of 80% or more (actually 84% or more) and a yellowness index (YI) of 15 or less. It was found that it has sufficiently high transparency based on the transmittance and the yellowness.

Here, paying attention to YI, the YI of the polymer (polyimide alloy or polyimide) obtained in each example and the content ratio (% by mass) of the varnish (B) in the varnish used for the preparation of the polymer A graph showing the relationship is shown in FIG. As is clear from the results shown in FIG. 5, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide (CpODA/DABAN) and the wholly aromatic polyimide (BPDA/PPD) is 0 to 61.1. The mass% of polyimide alloys (Comparative Examples 1 to 6) has a yellowness in the range of 24 to 36, and is a wholly aromatic polyimide (varnish (B Considering that the YI of the heat-cured product (BPDA/PPD)) is 24, even if the cycloaliphatic polyimide is mixed at a ratio of 61.1% by mass (Comparative Example 6), the YI of the polyimide alloy is It turned out that it cannot be lowered at all. On the other hand, from the results shown in FIG. 5, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide (CpODA/DABAN) and the wholly aromatic polyimide (BPDA/PPD) is 70.2% by mass to 93.%. In the polyimide alloys obtained in Examples 1 to 4 with 4% by mass, the polyimides obtained in Comparative Examples 1 to 6 with the content of cycloaliphatic polyimide being 0 to 61.1% by mass. It was revealed that the YI was dramatically reduced as compared with the alloy. From these results, in the polyimide alloy, when the cycloaliphatic polyimide was mixed with the wholly aromatic polyimide in a ratio such that the content of the cycloaliphatic polyimide was 62% by mass or more (in Examples 1 to 4, It was confirmed that YI was decreased in the obtained polyimide alloy) (YI was decreased non-linearly), and when the content of the cycloaliphatic polyimide was 62% by mass or more, the YI was dramatically increased. It turned out that it can be lowered.

The polyimide obtained in Comparative Example 8 obtained by mixing and reacting a wholly aromatic polyamic acid (addition polymer of BPDA and PPD) with CpODA and DABAN, and BPDA, PPD, CpODA and DABAN. All of the polyimides obtained in Comparative Example 9 obtained by mixing and reacting with were YI of 20, and YI could not be sufficiently reduced. In addition, the polyimides obtained in Comparative Examples 8 to 9 all have Td1% of 471° C., which is higher than Td1% of the cycloaliphatic polyimide (Comparative Example 7) which is a polycondensate of CpODA and DABAN. It was a low value.

From such results, by the polyimide alloy of the present invention containing a cycloaliphatic polyimide and wholly aromatic polyimide in a specific mass ratio, the obtained alloy reflects a sufficiently low YI characteristic of the cycloaliphatic polyimide. It is possible to exhibit excellent heat resistance by reflecting the high heat resistance (Td1%) of wholly aromatic polyimide while dramatically reducing YI, and having sufficiently high transparency and sufficiently high heat resistance. It was confirmed that it was possible to express

Regarding such a result, the present inventors first of all, in order to reduce the interaction between wholly aromatic polyimide molecules (formation of CT complex), which is the cause of coloring, with respect to the reduction of YI, at least 62%. It is speculated that it is necessary to mix the cycloaliphatic polyimide in an amount of at least mass%. Furthermore, as compared with those obtained by simply blending the monomers, as in Comparative Examples 8 to 9, the inventors of the present invention blended the varnish with the heat-cured product to give a cycloaliphatic polyimide and a wholly aromatic compound. Since the heat resistance is improved in the case of an alloy containing a group polyimide, the heat resistance becomes higher by the aromatic polyimide molecules acting as a reinforcing bar of reinforced concrete in the case of an alloy. I guess.

(Example 5)
Instead of the varnish (C), the varnish (C1) obtained by the “preparation step of the mixed varnish (C1)” described below was used, and the final heating temperature was changed from 400° C. to 360° C. A film-shaped polyimide was obtained by performing the same process as the “process for preparing a film-shaped polyimide alloy” adopted in Example 1.

<Preparation process of mixed varnish (C1) (polyimide alloy precursor resin solution)>
Instead of the cycloaliphatic polyamic acid varnish (A), a cycloaliphatic polyamic acid varnish (A1) obtained by the "preparation step of cycloaliphatic polyamic acid varnish (A1)" described below is used, and the cyclic The mass ratio of the aliphatic polyamic acid varnish (A1) to the wholly aromatic polyamic acid varnish (B) ([varnish (A1)]:[varnish (B)]) is 7.5:2.5. The same as the preparation step of the mixed varnish (C) of Example 1, except that the amount of the cyclic aliphatic polyamic acid varnish (A1) and the amount of the wholly aromatic polyamic acid varnish (B) used were changed. A mixed varnish that has been subjected to a step and mixed so that the mass ratio of the varnish (A1) to the varnish (B) ([varnish (A1)]:[varnish (B)]) is 7.5:2.5. (C1) was obtained.

<Preparation Step of Cyclic Aliphatic Polyamic Acid Varnish (A1)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, the following structural formula (XII):

3.0631 g of dicyclohexane-3,3',4,4'-tetracarboxylic dianhydride (abbreviation "H-BPDA", manufactured by LEAP Chem), which is a cycloaliphatic tetracarboxylic dianhydride represented by (10 mmol), 1.0814 g (10 mmol) of PPD, and 18.88 g of TMU were added, and the reaction was carried out at room temperature (25° C.) for 24 hours to give a cycloaliphatic polyamic acid having a solid content concentration of 18% by mass. A resin solution (cycloaliphatic polyamic acid varnish (A1)) of (addition polymer of H-BPDA and PPD) was obtained.

The cycloaliphatic polyamic acid varnish (A1) thus obtained was partially used to sample the cycloaliphatic polyamic acid (addition polymer of H-BPDA and PPD) from the varnish (A1), As a result of measuring the intrinsic viscosity [η] as described above, the intrinsic viscosity [η] of the cycloaliphatic polyamic acid (addition polymer of H-BPDA and PPD) was 0.327 dL/g.

(Comparative Example 10)
When preparing the mixed varnish (polyimide alloy precursor resin solution), the mass ratio of the cycloaliphatic polyamic acid varnish (A1) and the wholly aromatic polyamic acid varnish (B) ([varnish (A1)]:[varnish ( B)]) is 2.5:7.5, except that the amount of the cycloaliphatic polyamic acid varnish (A1) and the amount of the wholly aromatic polyamic acid varnish (B) used are changed. A polyimide alloy was obtained in the same manner as in Example 5.

(Comparative Example 11)
In the same manner as in Example 5 except that the cycloaliphatic polyamic acid varnish (A1) was used instead of the mixed varnish (C1) and the final heating temperature was changed from 360°C to 300°C, a film-like film was obtained. A cycloaliphatic polyimide was obtained.

[Characteristic Evaluation of Polymers Obtained in Example 5 and Comparative Examples 10 to 11]
The total light transmittance, yellowness (YI), 1% weight loss temperature (Td1%) and tensile strength of the polymers (polyimide alloys or polyimides) obtained in Example 5 and Comparative Examples 10 to 11 are shown in Examples 1 to 1. 4 and Comparative Examples 1 to 9 were measured by the same method as that used in the characteristic evaluation of the polymers. The results obtained are shown in Table 2. Table 2 also shows the results of Comparative Example 1 for reference.

From the composition of the varnish shown in Table 2, regarding the obtained polymer (polyimide alloy or polyimide), a cyclic polyimide formed from a cycloaliphatic polyamic acid (addition polymerization product of H-BPDA and PPD), and a wholly aromatic When the content of the cyclic polyimide with respect to the total amount of the wholly aromatic polyimide formed from the group-based polyamic acid (addition polymer of BPDA and PPD) was determined, respectively, 75.6 mass% (Example 5), 25. It turns out that it becomes 6 mass% (comparative example 10) and 100 mass% (comparative example 11).

As is clear from the results shown in Table 2, the polyimide alloy obtained in Example 5 had a Td of 1% of 424°C. In this regard, considering that the Td1% of the cycloaliphatic polyimide obtained in Comparative Example 11, which is a heat-cured product of the varnish (A1), is 276° C., considering that it is a polyimide alloy, the cycloaliphatic is It was confirmed that Td1% was extremely high as compared with the case where polyimide was used alone (Comparative Example 11). The polyimide alloy obtained in Example 5 has a total light transmittance of 80% or more (actually 87%) and a yellowness index (YI) of 15 or less (actually 7). It was found that it has sufficiently high transparency based on the total light transmittance and yellowness. As shown in Table 2, YI of the polyimide alloy obtained in Comparative Example 10 (containing 25.6% by mass of cycloaliphatic polyimide) was 23, and YI of the polyimide obtained in Comparative Example 1 was While the value is almost the same as that of (24), the polyimide alloy obtained in Example 5 containing the cycloaliphatic polyimide in a ratio of 75.6 mass% has YI of 7, and YI is It was confirmed that the value was sufficiently low.

(Example 6)
Instead of the varnish (C), the varnish (C2) obtained by the “preparation step of the mixed varnish (C2)” described below was used, and the final heating temperature was changed from 400° C. to 360° C. A film-shaped polyimide was obtained by performing the same process as the “process for preparing a film-shaped polyimide alloy” adopted in Example 1.

<Preparation process of mixed varnish (C2) (polyimide alloy precursor resin solution)>
Instead of using the cycloaliphatic polyamic acid varnish (A), except that the cycloaliphatic polyamic acid varnish (A2) obtained by the "preparation step of cycloaliphatic polyamic acid varnish (A2)" described below was used A step similar to the step of preparing the mixed varnish (C) of Example 1 was performed so that the mass ratio of the varnish (A2) to the varnish (B) ([varnish (A2)]:[varnish (B)]) was 6 A mixed varnish (C2) was obtained by mixing the varnishes (4) and (4).

<Preparation Step of Cyclic Aliphatic Polyamic Acid Varnish (A2)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, 3.8438 g (10 mmol) of CpODA, 1.5425 g (10 mmol) of norbornanediamine (abbreviated as “NBDA”, manufactured by Mitsui Chemicals Fine, Inc.), which is an aliphatic diamine, and 24 TMU. 0.54 g was added and the reaction was carried out at 80° C. for 24 hours to give a resin solution of a cycloaliphatic polyamic acid (addition polymer of CpODA and NBDA) having a solid content concentration of 18% by mass (cycloaliphatic polyamic acid varnish (A2 )) got.

The cycloaliphatic polyamic acid varnish (A2) thus obtained was partially utilized to sample the cycloaliphatic polyamic acid (addition polymerization product of CpODA and NBDA) from the varnish (A2), and as described above. The inherent viscosity [η] of the cycloaliphatic polyamic acid (addition polymer of CpODA and NBDA) was 0.348 dL/g.

(Comparative Example 12)
In the same manner as in Example 6 except that the cyclic aliphatic polyamic acid varnish (A2) was used instead of the mixed varnish (C2) and the final heating temperature was changed from 360°C to 300°C, a film-like film was obtained. A cycloaliphatic polyimide was obtained.

[Characteristic Evaluation of Polymers Obtained in Example 6 and Comparative Example 12]
The total light transmittance, the yellowness index (YI), the 1% weight loss temperature (Td1%), and the tensile strength of the polymers (polyimide alloy or polyimide) obtained in Example 6 and Comparative Example 12 are shown in Examples 1 to 4 and The measurement was carried out by the same method as that used in the characteristic evaluation of the polymers obtained in Comparative Examples 1 to 9. The results obtained are shown in Table 3. Table 3 also shows the results of Comparative Example 1 for reference.

From the composition of the varnish shown in Table 3, regarding the obtained polymer (polyimide alloy or polyimide), a cyclic polyimide formed from a cycloaliphatic polyamic acid (addition polymerization product of CpODA and NBDA), and a wholly aromatic system When the contents of cyclic polyimide with respect to the total amount of wholly aromatic polyimide formed from polyamic acid (addition polymerization product of BPDA and PPD) were calculated, respectively, 67.3 mass% (Example 6) and 100 mass% ( It turns out that it becomes comparative example 12).

As is clear from the results shown in Table 3, the polyimide alloy obtained in Example 6 had a Td of 1% of 431°C. In this regard, considering that Td1% of the cycloaliphatic polyimide (CpODA/NBDA) obtained in Comparative Example 12 which is a heat-cured product of the varnish (A2) is 284° C., it is a polyimide alloy, It was confirmed that Td1% was extremely high as compared with the case where the cycloaliphatic polyimide was used alone (Comparative Example 12). The polyimide alloy obtained in Example 6 has a total light transmittance of 80% or more (actually 87%) and a yellowness index (YI) of 15 or less (actually 8). It was found that it has sufficiently high transparency based on the total light transmittance and yellowness.

(Example 7)
Instead of the varnish (C), the varnish (C3) obtained by the “preparation step of the mixed varnish (C3)” described below was used, and the final heating temperature was changed from 400° C. to 360° C. A film-shaped polyimide was obtained by performing the same process as the “process for preparing a film-shaped polyimide alloy” adopted in Example 1.

<Preparation process of mixed varnish (C3) (polyimide alloy precursor resin solution)>
Instead of using the cycloaliphatic polyamic acid varnish (A), except that the cycloaliphatic polyamic acid varnish (A3) obtained by the "preparation step of cycloaliphatic polyamic acid varnish (A3)" described below was used A step similar to the step of preparing the mixed varnish (C) of Example 1 was performed so that the mass ratio of the varnish (A3) to the varnish (B) ([varnish (A3)]:[varnish (B)]) was 6 A mixed varnish (C3) was obtained by mixing the varnish (C3).

<Preparation process of cyclic aliphatic polyimide varnish (A3)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, 3.848 g (10 mmol) of CpODA, 3.4844 g (10 mmol) of 9,9-bis(4-aminophenyl)fluorene (abbreviation “FDA”, manufactured by Osaka Gas Chemicals), and γ- 33.38 g of a mixed solvent of butyrolactone (γ-BL) and N,N′-dimethylacetamide (DMAc) (the mass ratio of γ-BL and DMAc in the solvent (γ-BL:DMAc) is 80:20), In addition, 50.5 mg (0.5 mmol) of triethylamine, which is a reaction accelerator, was added and the reaction was carried out at 180° C. for 3 hours to give a resin solution of a cyclic aliphatic polyimide (polycondensation product of CpODA and FDA) (cyclic fat). A group polyimide varnish (A3) was obtained. The amount of the monomers (CpODA and FDA) (the amount of the monomers used for producing the polyimide) was 18% by mass with respect to the total amount of the monomers (CpODA and FDA) and the solvent (γ-BL and DMAc).

Using the cycloaliphatic polyimide varnish (A3) thus obtained in part, the polyimide is sampled from the varnish (A3), and the intrinsic viscosity [η] of the polyamic acid is the same except that the polyimide is used. As a result of measuring the intrinsic viscosity of the polyimide by adopting the same method as the measuring method, the intrinsic viscosity [η] was 0.454 dL/g.

(Comparative Example 13)
A film-form cycloaliphatic polyimide was obtained in the same manner as in Example 7 except that the cycloaliphatic polyimide varnish (A3) was used instead of the mixed varnish (C3).

[Characteristic Evaluation of Polymers Obtained in Example 7 and Comparative Example 13]
The total light transmittance, the yellowness index (YI), the 1% weight loss temperature (Td1%) and the tensile strength of the polymers (polyimide alloy or polyimide) obtained in Example 7 and Comparative Example 13 were measured in Examples 1 to 4 and The measurement was carried out by the same method as that used in the characteristic evaluation of the polymers obtained in Comparative Examples 1 to 9. The results obtained are shown in Table 4. Table 4 also shows the results of Comparative Example 1 for reference.

From the composition of the varnish shown in Table 4, regarding the obtained polymer (polyimide alloy or polyimide), cyclic polyimide (CpODA/FDA) obtained by heating and curing the varnish, and addition of wholly aromatic polyamic acid (BPDA and PPD) The content of cyclic polyimide with respect to the total amount of wholly aromatic polyimide formed from the polymer) is 74.0% by mass (Example 7) and 100% by mass (Comparative Example 13), respectively. I understand.

As is clear from the results shown in Table 4, the Td 1% of the polyimide alloy obtained in Example 7 was 494°C. Regarding this point, considering that the Td1% of the cycloaliphatic polyimide (CpODA/FDA) obtained in Comparative Example 12 which is a heat-cured product of the varnish (A3) is 489° C., it is a polyimide alloy, It was confirmed that Td1% was higher than that when the cycloaliphatic polyimide was used alone (Comparative Example 13). The polyimide alloy obtained in Example 7 has a total light transmittance of 80% or more and a yellowness index (YI) of 15 or less (actually 10). It has been found that the standard has sufficiently high transparency.

(Comparative Example 14)
Instead of the varnish (C), the varnish (C4) obtained by the "preparing step of mixed varnish (C4)" described below was used, and the final heating temperature was changed from 400°C to 360°C. A film-shaped polyimide was obtained by performing the same process as the “process for preparing a film-shaped polyimide alloy” adopted in Example 1.

<Preparation process of mixed varnish (C4) (polyimide alloy precursor resin solution)>
Instead of the cycloaliphatic polyamic acid varnish (A), a cycloaliphatic polyamic acid varnish (A4) obtained by the "preparation step of cycloaliphatic polyamic acid varnish (A4)" described below is used, and the varnish Mixing of Example 1 except that the amounts of (A4) and the varnish (B) used were changed so that the mass ratio of the varnish (A4) and the varnish (B) was 2.5:7.5. The mixed varnish (C4) was obtained by performing the same process as the varnish (C) preparation process.

<Preparation process of cyclic aliphatic polyamic acid varnish (A4)>
First, a 100 ml three-necked flask was heated with a heat gun to be sufficiently dried. Next, the atmosphere gas in the sufficiently dried three-necked flask was replaced with nitrogen to create a nitrogen atmosphere in the three-necked flask. Then, in the three-necked flask, the following structural formula (XIII):

1.9611 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (abbreviation "CBDA", manufactured by Tokyo Chemical Industry Co., Ltd.), which is a 4-membered cyclic aliphatic tetracarboxylic dianhydride represented by (10 mmol), 4,4′-bis(4-aminophenoxy)biphenyl (abbreviation “4-APBP”, manufactured by Nippon Pure Chemicals Co., Ltd.), 3.6843 g (10 mmol), and TMU25.72 g were added, and room temperature (25° C. ) For 24 hours to obtain a resin solution (cycloaliphatic polyamic acid varnish (A4)) of a cycloaliphatic polyamic acid (addition polymerization product of CBDA and 4-APBP) having a solid content concentration of 18% by mass. It was

(Comparative Example 15)
When preparing the mixed varnish (polyimide alloy precursor resin solution), the mass ratio of the cycloaliphatic polyamic acid varnish (A4) to the wholly aromatic polyamic acid varnish (B) ([varnish (A4)]:[varnish ( B)]) is 7.5:2.5 except that the amount of the cycloaliphatic polyamic acid varnish (A4) and the amount of the wholly aromatic polyamic acid varnish (B) are changed. A polyimide alloy was obtained in the same manner as in Comparative Example 14.

(Comparative Example 16)
The cyclic aliphatic polyamic acid varnish (A4) was used instead of the mixed varnish (C4), and the final heating temperature was changed from 360° C. to 300° C. A cycloaliphatic polyimide was obtained.

[Characteristic Evaluation of Polymers Obtained in Comparative Examples 14 to 16]
The total light transmittance and the yellowness index (YI) of the polymers (polyimide alloys or polyimides) obtained in Comparative Examples 14 to 16 were measured during the characterization of the polymers obtained in Examples 1 to 4 and Comparative Examples 1 to 9. The measurement was carried out using the same method as the measurement method used in. The results obtained are shown in Table 5. Table 5 also shows the results of Comparative Example 1 for reference.

From the composition of the varnish shown in Table 5, with respect to the obtained polymer (polyimide alloy or polyimide), a cyclic polyimide formed from a cycloaliphatic polyamic acid (addition polymer of CBDA and 4-APBP), and a wholly aroma When the contents of cyclic polyimides with respect to the total amount of wholly aromatic polyimides formed from the group-based polyamic acid (addition polymer of BPDA and PPD) were determined, respectively, 32.5 mass% (Comparative Example 14), 81. It turns out that it becomes 2 mass% (comparative example 15) and 100 mass% (comparative example 16).

As is clear from the results shown in Table 5, when the cyclic aliphatic polyimide in the polyimide alloy is used as a monomer and a cyclic aliphatic tetracarboxylic dianhydride having a 4-membered ring structure is used (Comparative Examples 14 to 15). ), the total light transmittance is less than 80%, and it is confirmed that the light transmittance is rather decreased as compared with the total light transmittance (81%) of the wholly aromatic polyimide. It was In addition, as is clear from the results shown in Table 5, when the cycloaliphatic polyimide in the polyimide alloy uses a cycloaliphatic tetracarboxylic dianhydride having a 4-membered ring structure as a monomer (Comparative Example 14 to 15), YI cannot be 15 or less, and even a polyimide alloy containing 81.2% by mass of a cycloaliphatic polyimide (Comparative Example 15) has a YI of 20, Taking into consideration that YI of the cycloaliphatic polyimide itself using the 4-membered cyclic aliphatic tetracarboxylic dianhydride as the monomer is 1 (see Comparative Example 16), the 4-membered cyclic structure as the monomer It has been found that it is difficult to sufficiently reduce YI even by simply containing a cycloaliphatic polyimide using an aliphatic tetracarboxylic acid dianhydride.

From the results shown in Tables 1 to 5 described above, in order to sufficiently reduce YI while setting the total light transmittance to 80% or more, as the monomer of the cycloaliphatic polyimide contained in the polyimide alloy, the above structural formula ( It has been found that it is necessary to utilize a cycloaliphatic tetracarboxylic dianhydride having a 6-membered ring structure (norbornane ring structure or cyclohexane ring structure) as shown in XI) to (XII).

As described above, according to the present invention, a polyimide alloy capable of having sufficiently high transparency while having sufficiently high transparency; suitably used for producing the polyimide alloy It is possible to provide a polyimide alloy precursor resin composition and a polyimide alloy precursor solution capable of producing the same, and a method for producing a polyimide alloy capable of efficiently producing such a polyimide alloy.

Therefore, since the polyimide alloy of the present invention is excellent in transparency and heat resistance, it can be used as a substitute for the glass substrate in applications where the glass substrate has been used (for example, TFT liquid crystal display). It is particularly useful as a material for forming a (film).

Claims (4)

A cycloaliphatic polyimide which is a polycondensate of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. ;as well as,
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyimide which is a polycondensation product of an acid dianhydride and an aromatic diamine;
Consists of, and
Content of the said cyclic aliphatic polyimide with respect to the total amount of the said cyclic aliphatic polyimide and the said wholly aromatic polyimide is 62-95 mass %, The polyimide alloy characterized by the above-mentioned. Cycloaliphatic polyamic acid which is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines An acid, and at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid;
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyamic acid which is a polyaddition product of an acid dianhydride and an aromatic diamine;
Consists of, and
Based on the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the cyclic Containing the cycloaliphatic polymer and the wholly aromatic polyamic acid at a ratio such that the content of the cycloaliphatic polyimide with respect to the total amount of the aliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass. A polyimide alloy precursor resin composition comprising: Cycloaliphatic polyamic acid which is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines An acid and at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid;
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Wholly aromatic polyamic acid which is a polyaddition product of an acid dianhydride and an aromatic diamine; and
solvent;
Contains, and
Based on the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the mass of the wholly aromatic polyimide obtained when the wholly aromatic polyamic acid is heat-cured, the cyclic Containing the cycloaliphatic polymer and the wholly aromatic polyamic acid at a ratio such that the content of the cycloaliphatic polyimide with respect to the total amount of the aliphatic polyimide and the wholly aromatic polyimide is 62 to 95% by mass. A polyimide alloy precursor resin solution comprising: Cycloaliphatic polyamic acid that is a polyaddition product of a cycloaliphatic tetracarboxylic dianhydride containing an aliphatic 6-membered ring and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines And a solution of at least one cycloaliphatic polymer selected from the group consisting of cycloaliphatic polyimides, which are ring-closing condensation products of the cycloaliphatic polyamic acid,
At least one aromatic tetracarboxylic acid selected from the group consisting of diphenyl-3,3',4,4'-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Acid dianhydride, a solution of wholly aromatic polyamic acid that is a polyaddition product of aromatic diamine, the mass of the cycloaliphatic polyimide obtained when the cycloaliphatic polymer is heat-cured and the total aroma. Based on the mass of wholly aromatic polyimide obtained when the group polyamic acid is heat-cured, the content of the cycloaliphatic polyimide with respect to the total amount of the cycloaliphatic polyimide and the wholly aromatic polyimide is 62 to 95. A step (A) of obtaining a polyimide alloy precursor resin solution by mixing in a proportion such that the mass% is
By heating and curing the polyimide alloy precursor resin solution,
A cycloaliphatic polyimide which is a polycondensate of a cycloaliphatic tetracarboxylic dianhydride having an aliphatic 6-membered ring structure and at least one diamine compound selected from the group consisting of aromatic diamines and aliphatic diamines. And at least one fragrance selected from the group consisting of diphenyl-3,3′,4,4′-tetracarboxylic dianhydride and benzene-1,2,4,5-tetracarboxylic dianhydride Group tetracarboxylic dianhydride and wholly aromatic polyimide which is a polycondensation product of aromatic diamine; and containing the cyclic aliphatic polyimide and the cyclic aliphatic polyimide with respect to the total amount of the wholly aromatic polyimide. A step (B) for obtaining a polyimide alloy having an amount of 62 to 95% by mass,
A method for producing a polyimide alloy, comprising: