Polyamic acid composition, polyimide composition, adhesive and laminate

Abstract

The polyamide acid composition according to the present disclosure comprises a polyamide acid. The monomers constituting the polyamide acid include, relative to the total monomers, 30-95 mol% of monomer (A) that has a diphenyl ether skeleton represented by general formula (1) or (2) but no benzophenone skeleton, and 0-5 mol% of monomer (B) that has a benzophenone skeleton. The diamines constituting the polyamide acid include aromatic diamine (β1) that has a diphenyl ether skeleton represented by general formula (2) and aliphatic diamine (β2) represented by general formula (3) or (4), and the molar ratio b / a of the diamines b to tetracarboxylic dianhydride a constituting the polyamide acid is 0.90-0.999.

Description

[Technical field]

[0001] The present disclosure relates to polyamic acid compositions, polyimide compositions, adhesives, and laminates. [Background technology]

[0002] Conventionally, epoxy resins have generally been used as adhesives for electronic circuit boards, semiconductor devices, etc. However, epoxy resins have insufficient heat resistance and flexibility, and require a long time for the thermosetting reaction.

[0003] On the other hand, thermoplastic polyimides are known to have high heat resistance and flexibility, as well as a relatively short thermosetting reaction time, and therefore the use of varnishes and films containing thermoplastic polyimides has been studied.

[0004] For example, there is a method of drying a coating of a varnish (solvent-soluble polyimide varnish) in which polyimide is dissolved in a solvent (for example, Patent Documents 1 to 3). Patent Document 1 discloses a solvent-soluble polyimide obtained by reacting an acid dianhydride component containing benzophenone tetracarboxylic dianhydride with a diamine component containing a specific siloxane compound. Patent Document 2 discloses a solvent-soluble polyimide obtained by reacting an acid dianhydride component containing benzophenone tetracarboxylic dianhydride with a diamine component containing a compound having a specific sulfonic acid skeleton. Patent Document 3 discloses a polyimide resin composition containing an aromatic tetracarboxylic dianhydride or aromatic diamine having a benzophenone skeleton. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-255780 [Patent Document 2] JP 2001-310336 A [Patent Document 3] International Publication No. 2013 / 008437 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the films obtained from the polyimide varnishes of Patent Documents 1 and 2 did not have sufficient flexibility. Therefore, compositions containing these polyimides were not suitable for applications requiring flexibility.

[0007] Incidentally, in the manufacturing process of electronic circuit boards, semiconductor devices, etc., it is desired that after a thermoplastic polyimide film is applied as an adhesive, it can be peeled off without leaving any adhesive residue. There are methods for peeling such as laser lift-off (LLO), mechanical peeling, and methods of dissolving and removing with a solvent, but from the viewpoint of easy peeling at low cost, it is required that it can be dissolved and removed with a solvent. Although the polyimide composition of Patent Document 3 has good heat resistance and flexibility, further improvement is required in terms of solubility in a solvent (resolubility) after it is made into a film.

[0008] Furthermore, manufacturing processes for electronic circuit boards and semiconductor devices involve heating steps such as electrode film formation and rewiring, and the thermoplastic polyimide films used therein are required to have heat resistance capable of withstanding such high temperatures.

[0009] The present disclosure has been made in view of the above circumstances, and aims to provide a polyamic acid composition capable of imparting a polyimide film having both high heat resistance and mechanical properties (elongation) and excellent resolubility, and also aims to provide a polyimide composition and an adhesive using the polyamic acid composition. [Means for solving the problem]

[0010] The polyamic acid composition of the present disclosure is a polyamic acid obtained by polycondensing a tetracarboxylic dianhydride monomer and a diamine, the monomers constituting the polyamic acid including 30 to 97 mol % of a monomer (A) having a diphenyl ether skeleton represented by general formula (1) or (2) and 0 to 5 mol % of a monomer (B) having a benzophenone skeleton, based on the total amount of the monomers constituting the polyamic acid, the diamines constituting the polyamic acid including an aromatic diamine (β1) having a diphenyl ether skeleton represented by general formula (2) and an aliphatic diamine represented by general formula (3) or an aliphatic diamine (β2) represented by general formula (4), and the molar ratio of the diamines constituting the polyamic acid to the tetracarboxylic dianhydride is diamine / tetracarboxylic dianhydride=0.90 to 0.999. [ka] [ka] (In general formula (3), R1 is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 7 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, and O, and the total number of atoms constituting the side chain is 10 or less. [ka] (In general formula (4), R2 is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 5 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, and O, and the total number of atoms constituting the side chain is 10 or less.

[0011] The polyimide composition of the present disclosure is a polyimide obtained by polycondensing a tetracarboxylic dianhydride and a diamine, which are monomers, in which the monomers constituting the polyimide include 30 to 97 mol % of a monomer (A) having a diphenyl ether skeleton and represented by general formula (1) or (2) and 0 to 5 mol % of a monomer (B) having a benzophenone skeleton, based on the total amount of the monomers constituting the polyimide; the diamines constituting the polyimide include an aromatic diamine (β1) having a diphenyl ether skeleton and represented by general formula (2), and an aliphatic diamine (β2) represented by general formula (3) or (4), in which the molar ratio of the diamines constituting the polyimide to the tetracarboxylic dianhydride is diamine / tetracarboxylic dianhydride=0.90 to 0.999. [ka] [ka] (In general formula (3), R1 is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 7 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, and O, and the total number of atoms constituting the side chain is 10 or less. [ka] (In general formula (4), R2 is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 5 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, and O, and the total number of atoms constituting the side chain is 10 or less.

[0012] The adhesive of the present disclosure comprises the polyimide composition of the present disclosure.

[0013] The laminate of the present disclosure has a substrate and a resin layer including the polyimide composition of the present disclosure disposed on the substrate. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a polyamic acid composition capable of forming a polyimide film having both high heat resistance and mechanical properties (elongation) and excellent resolubility, and also to provide a polyimide composition and an adhesive using the polyamic acid composition. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a test piece used in a tensile break test. [Diagram 2] 2A to 2H are schematic cross-sectional views showing an example of a process for processing a silicon substrate using the polyimide composition of the present disclosure as a temporary fixing adhesive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In this specification, a numerical range expressed using "~" means a range including the numerical values ​​described before and after "~" as the lower and upper limits, respectively. In numerical ranges described in stages in this specification, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages.

[0017] As a result of intensive research, the present inventors have found that by 1) making the molecular terminal of the polyamic acid an acid anhydride group, 2) containing a certain amount of monomer (A) having a diphenyl ether skeleton but not a benzophenone skeleton, and 3) reducing the amount of monomer (B) having a benzophenone skeleton as much as possible (making it substantially absent), it is possible to improve the resolubility of the obtained polyimide film while maintaining good mechanical properties.

[0018] The mechanism behind this is unclear, but is speculated to be as follows. By making the molecular end of the polyamic acid an acid anhydride group, it is believed that the interaction within or between the molecular chains of the resulting polyimide is reduced, and the solubility (resolubility) in a solvent after the polyimide film is made can be improved. In addition, since the monomer constituting the polyamic acid does not substantially contain the monomer (B) having a benzophenone skeleton, the increase in the degree of crosslinking caused by the crosslinking reaction between the carbonyl group of the benzophenone skeleton and the amine part in the molecule of the polyamic acid is suppressed, and the polyamic acid has a flexible structure derived from the monomer (A) having a diphenyl ether skeleton, and the solubility (resolubility) in a solvent of the resulting polyimide film can be improved.

[0019] Thus, polyimides having a relatively flexible structure and high resolubility tend to have difficulty in maintaining heat resistance. In contrast, in the present disclosure, 4) the heat resistance of the resulting polyimide can be improved by further including an aromatic diamine (β1) as a diamine constituting the polyamic acid. As a result, good heat resistance can be obtained without forming hydrogen bonds between the amino groups at the molecular terminals of the polyamic acid and the carbonyl groups of the benzophenone skeleton, as in Patent Document 3. The configuration of the present disclosure will be described below.

[0020] 1. Polyamic acid composition The polyamic acid composition of the present disclosure contains a specific polyamic acid, and may further contain other optional components such as a solvent, as necessary.

[0021] 1-1. Polyamic acid The monomers constituting the polyamic acid include a monomer (A) that does not have a benzophenone skeleton but has a diphenyl ether skeleton. Such a monomer (A) has flexibility while maintaining a moderate rigidity, and has a structure in which the molecular chains can move freely, so it is presumed that packing between polyimide molecular chains is easily suppressed. As a result, it is presumed that the resolubility of the polyimide film in a solvent can be increased (while maintaining the heat resistance of the obtained polyimide). It is preferable that the monomer (A) does not have a biphenyl skeleton.

[0022] However, the content of the monomer (B) having a benzophenone skeleton in the monomers constituting the polyamic acid is 5 mol % or less, preferably less than 3 mol %, and more preferably less than 1 mol %, based on the total content of the monomers constituting the polyamic acid, because the carbonyl group of the monomer (B) having a benzophenone skeleton crosslinks with the amine moiety in the molecule of the polyamic acid, which tends to reduce the resolubility of the resulting polyimide film.

[0023] Specifically, the polyamic acid contains a polycondensation unit of a tetracarboxylic dianhydride and a diamine; the tetracarboxylic dianhydride contains an aromatic tetracarboxylic dianhydride (α1) having no benzophenone skeleton but a diphenyl ether skeleton, or the diamine contains an aromatic diamine (β1) having no benzophenone skeleton but a diphenyl ether skeleton (these are collectively referred to as "monomer (A) having no benzophenone skeleton but a diphenyl ether skeleton"). However, the content of the tetracarboxylic dianhydride and the diamine, an aromatic tetracarboxylic dianhydride (α3) having a benzophenone skeleton and an aromatic diamine (β4) having a benzophenone skeleton (these are collectively referred to as "monomer (B) having a benzophenone skeleton") is 5 mol % or less based on the total content of the monomers constituting the polyamic acid.

[0024] (Tetracarboxylic acid dianhydride) The tetracarboxylic dianhydride constituting the polyamic acid does not have a benzophenone skeleton, and may contain an aromatic tetracarboxylic dianhydride (α1) having a diphenyl ether skeleton represented by general formula (1) or (2). [ka]

[0025] The aromatic tetracarboxylic dianhydride (α1) having no benzophenone skeleton but a diphenyl ether skeleton is preferably a compound represented by the following formula (5). [ka]

[0026] In general formula (5), X is a substituted or unsubstituted arylene group having 6 to 10 carbon atoms or a group represented by the following formula (a): n is 0 or 1, and is preferably 0. [ka]

[0027] Examples of the substituted or unsubstituted arylene group having 6 to 10 carbon atoms include a phenylene group and a naphthylene group. The substituent may be an alkyl group or the like, and a plurality of the substituents may be bonded to each other to form a ring. Examples of the ring include an alicyclic ring such as a cyclohexane ring or a norbornane ring.

[0028] In formula (a), Y is an oxygen atom, a sulfur atom, a sulfone group, a methylene group, a fluorene structure, -CR 1 R 2 -(R 1 and R 2 represents a divalent group selected from the group consisting of a substituted or unsubstituted alkyl group or phenyl group having 1 to 3 carbon atoms.

[0029] R 1 and R 2 Examples of the substituted or unsubstituted alkyl group having 1 to 3 carbon atoms as the alkyl group include a methyl group, an ethyl group, a propyl group, a trifluoropropyl group, and the like. For example, -CR 1 R 2 - can be an isopropylidene group or a hexafluoroisopropylidene group. 1 and R 2 may be bonded to each other to form a ring. 1 and R 2 Examples of the ring formed by the bonding of may include a cyclohexane ring or a cyclopentane ring, and these rings may be condensed with aromatic rings such as a benzene ring. Such linking groups have a three-dimensionally expanding structure, which makes it easy to increase the resolubility of the resulting polyimide.

[0030] Examples of aromatic tetracarboxylic dianhydrides (α1) that do not have a benzophenone skeleton and have a diphenyl ether skeleton include 4,4'-(4,4'-isopropylidenediphenoxy)bisphthalic anhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 4,4'-oxydiphthalic anhydride, 3,4'-oxydiphthalic anhydride, 3,3'-oxydiphthalic anhydride, and the compounds shown below. These can be used alone or in combination. Among them, from the viewpoint of availability, a compound in which n is 0 in the general formula (5) is preferred, and 4,4'-oxydiphthalic anhydride is preferred. [ka] [ka]

[0031] Incidentally, the aromatic tetracarboxylic dianhydride (α1) having no benzophenone skeleton but having a diphenyl ether skeleton preferably does not have a biphenyl skeleton.

[0032] The tetracarboxylic dianhydride constituting the polyamic acid may further contain another tetracarboxylic dianhydride other than the aromatic tetracarboxylic dianhydride (α1) having a diphenyl ether skeleton and no benzophenone skeleton. The other tetracarboxylic dianhydride is not particularly limited, but from the viewpoint of heat resistance, it is preferable to use an aromatic tetracarboxylic dianhydride.

[0033] Examples of aromatic tetracarboxylic dianhydrides, which may be other tetracarboxylic dianhydrides, include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 1,1',2,2'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 1,2,2',3-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3 ,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,3,6,7-naphthalene dianhydride Phthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)sulfide dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, 1,3-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(2,3 -dicarboxyphenoxy)benzene dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 4,4'-isophthaloyl diphthalic anhydride, diazodiphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, diazodiphenylmethane-2,2',3,3'-tetracarboxylic dianhydride, 2,3,6,7-thioxanthone tetracarboxylic dianhydride, 2,3,6,7-anthraquinone tetracarboxylic dianhydride, 2,3,6,7-xanthone tetracarboxylic dianhydride, ethylene tetracarboxylic dianhydride, and the like.

[0034] When the tetracarboxylic dianhydride constituting the polyimide contains an aromatic ring such as a benzene ring, some or all of the hydrogen atoms on the aromatic ring may be substituted with a group selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, a trifluoromethoxy group, etc. These may be used alone or in combination of two or more.

[0035] From the viewpoint of obtaining high heat resistance without significantly impairing flexibility, the other tetracarboxylic acid dianhydride preferably includes an aromatic tetracarboxylic acid dianhydride, and more preferably includes an aromatic tetracarboxylic acid dianhydride (α2) having a biphenyl skeleton, such as 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 1,2,1',2'-biphenyltetracarboxylic acid dianhydride, 2,3,2',3'-biphenyltetracarboxylic acid dianhydride, or 1,2,2',3-biphenyltetracarboxylic acid dianhydride.

[0036] However, as described above, from the viewpoint of obtaining high resolubility, it is preferable that the tetracarboxylic dianhydride constituting the polyimide does not substantially contain an aromatic tetracarboxylic dianhydride (α3) having a benzophenone skeleton. Examples of the aromatic tetracarboxylic dianhydride (α3) having a benzophenone skeleton include 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,3,3',4'-benzophenone tetracarboxylic dianhydride, and 2,2',3,3'-benzophenone tetracarboxylic dianhydride.

[0037] (Diamine) The diamine constituting the polyamic acid does not have a benzophenone skeleton, but contains an aromatic diamine (β1) having a diphenyl ether skeleton represented by general formula (2). [ka]

[0038] The aromatic diamine (β1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (2) preferably has three or more aromatic rings, and examples thereof include the compound represented by general formula (2-1). [ka]

[0039] In the general formula (2-1), Z is an oxygen atom, a sulfur atom, a sulfone group, a methylene group, a fluorene structure, -CR 1 R 2 -(R 1 and R 2 represents a divalent group selected from the group consisting of a substituted or unsubstituted alkyl group or phenyl group each having 1 to 3 carbon atoms.

[0040] R 1 and R 2 Examples of the alkyl group having 1 to 3 carbon atoms as the --CR group include a methyl group, an ethyl group, a propyl group, and a trifluoropropyl group. 1 R 2 - can be an isopropylidene group or a hexafluoroisopropylidene group. 1 and R 2 may be bonded to each other to form a ring. 1 and R 2 Examples of the ring formed by the bonding of may include a cyclohexane ring or a cyclopentane ring, and these rings may be condensed with aromatic rings such as a benzene ring. Such linking groups have a three-dimensionally expanding structure, which makes it easy to increase the resolubility of the resulting polyimide.

[0041] Among the aromatic diamines (β1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by the general formula (1), examples of those having three or more aromatic rings include bis[4-(3-aminophenoxy)phenyl]sulfide, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-(3-aminophenoxy)phenoxy)benzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)benzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)benzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)benzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)benzene, bis(3-(3-aminophenoxy)phenoxy)-2-methylbenzene, 1,3-bis(3-(4-aminophenoxy)phenoxy)-4-methylbenzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)-2-ethylbenzene, 1,3-bis(3-(2-aminophenoxy)phenoxy)-5-sec-butylbenzene, 1,3-bis(4-(3-aminophenoxy)phenoxy)-2,5-dimethylbenzene, 1,3-bis(4-(2-amino-6-methylphenoxy)phenoxy)benzene, 1,3-bis(2-(2-amino-6-methylphenoxy)phenoxy)benzene, 1,3-bis(2-(3-aminophenoxy)-4-methylphenoxy)benzene, 1,3-bis(2-(4-aminophenoxy)-4-tert-butylphenoxy)benzene, 1,4-bis(3-(3-aminophenoxy)phenoxy)-2,5-di-tert-butylbenzene, 1,4-bis(3-(4-aminophenoxy)phenoxy)-2,3-dimethylbenzene, 1,4-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 1,2-bis(3-(3-aminophenoxy)phenoxy)benzene, )phenoxy)-4-methylbenzene, 1,2-bis(3-(4-aminophenoxy)phenoxy)-3-n-butylbenzene, 1,2-bis(3-(2-amino-3-propylphenoxy)phenoxy)benzene, 4,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,These include 2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfoxide, bis[4-(aminophenoxy)phenyl]sulfoxide, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, and diamines represented by the following formula. [ka] [ka] Among these, aromatic diamines represented by the general formula (2-1), such as 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, and 2,2-bis[4-(4-aminophenoxy)phenyl]propane, are more preferred.

[0042] Incidentally, it is preferable that the aromatic diamine (β1) having no benzophenone skeleton but having a diphenyl ether skeleton does not have a biphenyl skeleton.

[0043] The diamine constituting the polyamic acid preferably further contains an aliphatic diamine (β2). The aliphatic diamine (β2) is preferably an aliphatic diamine represented by general formula (3) or (4). The polyamic acid composition may contain only one of the aliphatic diamines represented by general formula (3) or (4), or may contain both. [ka] [ka]

[0044] R1 in general formula (3) and R2 in general formula (4) each represent an aliphatic chain having a main chain composed of one or more atoms of C, N, or O, preferably an aliphatic chain having a main chain containing one or more C atoms. The total number of atoms constituting the main chain is preferably 5 to 500, more preferably 10 to 500, even more preferably 21 to 300, and even more preferably 50 to 300. The main chain in R1 in general formula (3) refers to an aliphatic chain connecting two phenyl groups at the molecular terminals, and is composed of atoms other than the atoms constituting the side chain; the main chain in R2 in general formula (4) refers to an aliphatic chain connecting two amino groups at the molecular terminals, and is composed of atoms other than the atoms constituting the side chain.

[0045] Examples of main chains consisting of one or more atoms of C, N, and O that constitute an aliphatic chain include main chains having a structure derived from polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; main chains containing an alkylene group; main chains having a polyalkylene glycol structure; main chains having an alkyl ether structure; main chains having a polyalkylene carbonate structure; and main chains containing an alkyleneoxy group or a polyalkyleneoxy group, and preferably main chains containing an alkyleneoxy group or a polyalkyleneoxy group.

[0046] A polyalkyleneoxy group is a divalent linking group that contains alkyleneoxy as a repeating unit, and is a repeating unit of ethyleneoxy units such as "-(CH2CH2O) n -" and "-(CH2-CH(-CH3)O)" which has propyleneoxy units as repeating units. m -" (n and m are the numbers of repetitions). The number of repetitions of the alkyleneoxy units in the polyalkyleneoxy group is preferably 2 to 50, more preferably 2 to 20, and even more preferably 2 to 15. The polyalkyleneoxy group may contain multiple types of alkyleneoxy units.

[0047] The number of carbon atoms in the alkylene portion of the alkyleneoxy group and the alkylene portion of the alkyleneoxy unit constituting the polyalkyleneoxy group is preferably 1 to 10, more preferably 2 to 10. Examples of the alkylene group constituting the alkyleneoxy group include a methylene group, an ethylene group, a propylene group, and a butylene group. If the alkylene group constituting the alkyleneoxy group or the polyalkyleneoxy group has a butylene group, the polyimide film obtained from the polyimide composition of the present disclosure exhibits excellent breaking strength, which is preferable.

[0048] In the main chain of R1 or R2, the group linking the alkyleneoxy group or polyalkyleneoxy group to the terminal amino group is not particularly limited and may be an alkylene group, an arylene group, an alkylenecarbonyloxy group, an arylenecarbonyloxy group, etc., and from the viewpoint of increasing the reactivity of the terminal amino group, an alkylene group is preferred.

[0049] The aliphatic chains represented by R1 and R2 may further have a side chain consisting of one or more atoms of C, N, H, and O. The side chains in R1 and R2 are monovalent groups connected to atoms constituting the main chain. The total number of atoms constituting each side chain is preferably 10 or less. Examples of the side chain include not only alkyl groups such as methyl groups, but also hydrogen atoms.

[0050] In this manner, since the aliphatic diamine (β2) represented by the general formula (3) or (4) contains a long aliphatic chain, the resulting polyimide has high flexibility.

[0051] The aliphatic diamine represented by the general formula (3) is preferably a compound represented by the general formula (3-1). The aliphatic diamine represented by the general formula (4) is preferably a compound represented by the general formula (4-1). [ka] [ka]

[0052] In general formula (3-1), o represents an integer of 1 to 50, and preferably an integer of 10 to 20. In general formula (4-1), p, q, and r each independently represent an integer of 0 to 10, provided that p+q+r is 1 or more, and preferably 5 to 20.

[0053] Since the aliphatic diamine represented by the general formula (3-1) or (4-1) contains a long-chain alkyleneoxy group, the resulting polyimide has high flexibility.

[0054] The weight-average molecular weight of the aliphatic diamine (β2) represented by general formula (3) or (4) is, for example, preferably 100 to 5000, more preferably 250 to 1500, and further preferably 500 to 1300. When the weight-average molecular weight of the aliphatic diamine (β2) is a certain level or higher, the alkyleneoxy group is appropriately long, so that the flexibility and resolubility of the polyimide can be easily further increased, and when it is a certain level or lower, the heat resistance of the polyimide is less likely to be impaired.

[0055] The weight average molecular weight of the aliphatic diamine (β2) can be measured by gel permeation chromatography (GPC).

[0056] The diamine constituting the polyimide may further contain other diamines other than the aromatic diamine (β1) and the aliphatic diamine (β2) having a diphenyl ether skeleton, without having a benzophenone skeleton. The other diamines are not particularly limited and are aromatic diamines other than the aromatic diamine (β1), aliphatic diamines other than the aliphatic diamine (β2), or alicyclic diamines, and from the viewpoint of improving heat resistance, are preferably aromatic diamines other than the aromatic diamine (β1).

[0057] Examples of aromatic diamines other than the aromatic diamine (β1) include: m-Phenylenediamine, o-Phenylenediamine, p-Phenylenediamine, m-Aminobenzylamine, p-Aminobenzylamine, Bis(3-aminophenyl)sulfide, (3-aminophenyl)(4-aminophenyl)sulfide, Bis(4-aminophenyl)sulfide, Bis(3-aminophenyl)sulfoxide, (3-aminophenyl)(4-aminophenyl)sulfoxide, Bis(3-aminophenyl)sulfone, (3-aminophenyl)(4-aminophenyl)sulfone, Bis( 4-aminophenyl)sulfone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-dimethylbenzidine, 3,4'-dimethylbenzidine, 4,4'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-1,1'-biphenyl-4,4'-diamine, 4,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3,4'-bis(4-aminophenyl)-1,4-diisopropylbenzene, 3, 3'-bis(4-aminophenyl)-1,4-diisopropylbenzene, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 2,2-bis[4-(3-aminophenoxy )phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]butane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfoxide, bis[4-(aminophenoxy)phenyl]sulfoxide, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophen 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, and the like. Among these, from the viewpoint of obtaining high heat resistance without significantly impairing flexibility, the aromatic diamine other than the aromatic diamine (β1) may preferably include an aromatic diamine (β3) having a biphenyl skeleton, such as 3,3'-bis(4-aminophenoxy)biphenyl, 2,2'-bis(trifluoromethyl)-1,1'-biphenyl-4,4'-diamine, 3,3'-dimethylbenzidine, 3,4'-dimethylbenzidine, or 4,4'-dimethylbenzidine.

[0058] Examples of aliphatic diamines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, and the like, with ethylenediamine being preferred.

[0059] Examples of alicyclic diamines include cyclobutanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, di(aminomethyl)cyclohexane [bis(aminomethyl)cyclohexane excluding 1,4-bis(aminomethyl)cyclohexane], diaminobicycloheptane, diaminomethylbicycloheptane (including norbornanediamines such as norbornanediamine), diaminooxybicycloheptane, diaminomethyloxybicycloheptane (including oxanorbornanediamine), isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis(aminocyclohexyl)methane [or methylenebis(cyclohexylamine)], bis(aminocyclohexyl)isopropylidene, etc. Among them, norbornanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, and 1,4-cyclohexanediamine are preferred because they can increase heat resistance without significantly decreasing flexibility.

[0060] However, as described above, it is preferable that the diamine constituting the polyamic acid does not substantially contain an aromatic diamine (β4) having a benzophenone skeleton. Examples of the aromatic diamine (β4) having a benzophenone skeleton include aromatic diamines having a benzophenone skeleton represented by the general formula (6). [ka]

[0061] Examples of the aromatic diamine having a benzophenone skeleton represented by the general formula (6) include 3,3'-diaminobenzophenone, 3,4-diaminobenzophenone, and 4,4'-diaminobenzophenone.

[0062] The total of the aromatic tetracarboxylic dianhydride (α1) having no benzophenone skeleton but a diphenyl ether skeleton and the aromatic diamine (β1) having no benzophenone skeleton but a diphenyl ether skeleton (total of monomers (A)) is preferably 30 to 97 mol %, more preferably 30 to 90 mol %, more preferably 40 to 85 mol %, and even more preferably 55 to 75 mol % based on the total of the tetracarboxylic dianhydride and diamine constituting the polyamic acid (total of all monomers). When the total of the aromatic tetracarboxylic dianhydride (α1) and the aromatic diamine (β1) is 30 mol % or more, a polyimide having excellent resolubility while having heat resistance is easily obtained.

[0063] The content of aromatic tetracarboxylic dianhydride (α1) having neither biphenyl nor benzophenone skeleton but diphenyl ether skeleton in the tetracarboxylic dianhydride constituting the polyamic acid is not particularly limited as long as it satisfies the above range, but is preferably 30 mol% or more, more preferably 35 to 70 mol%, and even more preferably 40 to 60 mol% relative to the total of tetracarboxylic dianhydrides constituting the polyamic acid (or the total of aromatic tetracarboxylic dianhydride (α1) having diphenyl ether skeleton and aromatic tetracarboxylic dianhydride (α2) having biphenyl skeleton). When the content of the aromatic tetracarboxylic dianhydride (α1) is 30 mol% or more, the resolubility of the resulting polyimide is easily further increased.

[0064] In the diamines constituting the polyamic acid, the content of the aromatic diamine (β1) having neither a biphenyl skeleton nor a benzophenone skeleton, but a diphenyl ether skeleton represented by general formula (2), is not particularly limited as long as it satisfies the above range, but from the viewpoint of sufficiently increasing the heat resistance of the resulting polyimide, it is preferably 50 to 95 mol %, more preferably 65 to 90 mol %, based on the total of the diamines constituting the polyamic acid (or the total of the aromatic diamine (β1) and the aliphatic diamine (β2)). When the content of the aromatic diamine (β1) is within the above range, it is easy to further increase the heat resistance of the resulting polyimide.

[0065] In the diamines constituting the polyamic acid, the amount of aliphatic diamines (β2) represented by general formula (3) or (4) (total amount of diamines represented by general formula (3) or (4)) is preferably 5 to 45 mol %, more preferably 10 to 30 mol %, based on the total of diamines constituting the polyamic acid (or the total of aromatic diamines (β1) and aliphatic diamines (β2)), from the viewpoint of imparting high flexibility without significantly decreasing the heat resistance of the resulting polyimide. When the content of the aliphatic diamine (β2) is within the above range, it is easy to further improve mechanical properties such as elongation while maintaining the heat resistance of the resulting polyimide.

[0066] The total of the aromatic tetracarboxylic dianhydride (α2) having a biphenyl skeleton and the aromatic diamine (β3) having a biphenyl skeleton (total of monomers (C) having a biphenyl skeleton) is not particularly limited, but is preferably 50 mol% or less, and from the viewpoint of sufficiently increasing the heat resistance of the resulting polyimide, it is more preferably 5 to 50 mol% and even more preferably 20 to 40 mol% based on the total of the tetracarboxylic dianhydride and diamine constituting the polyamic acid (total of all monomers). When the content of the aromatic tetracarboxylic dianhydride (α2) is within the above range, it is easy to further increase the heat resistance while maintaining the mechanical properties and resolubility of the resulting polyimide.

[0067] The monomer composition of the polyamic acid can be confirmed, for example, by hydrolyzing it with an alkali and subjecting the separated components to NMR analysis.

[0068] In order to make the molecular terminal of the polyamic acid an acid anhydride group, the amount of the tetracarboxylic dianhydride component (a moles) to be reacted should be greater than the amount of the diamine component (b moles). Specifically, the molar ratio of the diamine (b moles) and the tetracarboxylic dianhydride (a moles) constituting the polyamic acid is preferably b / a=0.90 to 0.999, more preferably 0.95 to 0.995, and even more preferably 0.97 to 0.995. When b / a is 0.999 or less, the molecular terminal of the obtained polyimide is easily converted to an acid anhydride group, so that resolubility is easily obtained. b / a can be specified as the charge ratio of the tetracarboxylic dianhydride component (a moles) and the diamine component (b moles) to be reacted.

[0069] The polyamic acid may be a random polymer or a block polymer.

[0070] From the viewpoint of facilitating film formation, the intrinsic viscosity η of the polyamic acid is preferably 0.3 to 2.0 dL / g, and more preferably 0.5 to 1.5 dL / g. The intrinsic viscosity (η) of the polyamic acid is the average value measured three times at 25°C using an Ubbelohde viscometer when the polyamic acid is dissolved in N-methyl-2-pyrrolidone (NMP) to a concentration of 0.5 g / dL.

[0071] The intrinsic viscosity (η) of the polyamic acid can be adjusted by the molar ratio (b / a) of the diamine (b moles) and the tetracarboxylic dianhydride (a moles) that constitute the polyamic acid.

[0072] When polyamic acid is imidized to form a polyimide (film), it has the following heat resistance (Tg, T d5 ), resolubility and mechanical properties (elongation) can be exhibited.

[0073] 1-2.Other ingredients The polyamic acid composition of the present disclosure may further contain other components in addition to the above-mentioned polyamic acid, if necessary.

[0074] For example, the polyamic acid composition may further include a solvent. The solvent may be a solvent used in the preparation of polyamic acid, and is not particularly limited as long as it can dissolve the diamine component and the tetracarboxylic dianhydride component. For example, aprotic polar solvents and alcohol-based solvents can be used.

[0075] Examples of aprotic polar solvents include N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and ether compounds such as 2-methoxyethanol, 2-ethoxyethanol, 2-(methoxymethoxy)ethoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, tetrahydrofurfuryl alcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and the like. ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monoethyl ether, tetraethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, polyethylene glycol, polypropylene glycol, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and the like.

[0076] Examples of the alcohol-based solvent include methanol, ethanol, 1-propanol, 2-propanol, tert-butyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 1,2,6-hexanetriol, and diacetone alcohol.

[0077] These solvents may be used alone or in combination of two or more. Among them, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, or a mixture thereof is preferred.

[0078] From the viewpoint of improving coatability, the concentration of resin solids in the polyamic acid varnish is preferably from 5 to 50% by weight, and more preferably from 10 to 30% by weight.

[0079] Method for producing polyamic acid composition The polyamic acid composition can be obtained by mixing a tetracarboxylic dianhydride component and a diamine component in a solvent and reacting them. The types of the solvent, tetracarboxylic dianhydride component, and diamine component used and the amount ratio thereof are as described above.

[0080] The reaction for obtaining the polyamic acid composition is preferably carried out by heating the above-mentioned tetracarboxylic dianhydride and diamine in a solvent at a relatively low temperature (a temperature at which imidization does not occur). Specifically, the temperature at which imidization does not occur may be 5 to 120° C., more preferably 25 to 80° C. In addition, the reaction is preferably carried out in an environment substantially free of an imidization catalyst (e.g., triethylamine, etc.).

[0081] 2. Polyimide composition The polyimide composition of the present disclosure includes a specific polyimide obtained by imidizing the polyamic acid contained in the polyamic acid composition. The polyimide composition including such a specific polyimide is obtained by heating the polyamic acid composition to imidize the polyamic acid. The polyimide composition of the present disclosure may be a film.

[0082] The temperature at which the polyamic acid is imidized may be, for example, 150 to 200°C. Therefore, if the temperature of the coating film is suddenly increased to 200°C or higher, the polyamic acid on the surface of the coating film is imidized before the solvent evaporates from the coating film. As a result, the solvent remaining in the coating film generates air bubbles or causes unevenness on the coating film surface. Therefore, in the temperature range of 50 to 200°C, it is preferable to gradually increase the temperature of the coating film. Specifically, the heating rate in the temperature range of 50 to 200°C is preferably 0.25 to 30°C / min, more preferably 1 to 20°C / min, and even more preferably 2 to 10°C / min. Heating is preferably performed for 30 minutes in the temperature range of 50 to 200°C. The preferred imidization conditions are to increase the temperature from 50°C to 200°C at 5°C / min in the air and then heat at 200°C for 30 minutes.

[0083] The temperature may be increased continuously or stepwise (sequentially), but it is preferable to increase the temperature continuously in order to prevent the appearance of the resulting polyimide film from being defective. In addition, the temperature increase rate may be constant or may be changed during the entire temperature range described above.

[0084] That is, it is preferable that the polyimide composition (polyimide, polyimide film, etc.) obtained by heating the polyamic acid composition of the present invention under the above-mentioned conditions and imidizing it satisfies the following physical properties.

[0085] (1) Heat resistance (Glass transition temperature (Tg)) The glass transition temperature of the polyimide film is preferably 95° C. or higher and lower than 260° C., and more preferably 110 to 170° C. Polyimides having a glass transition temperature in the above range have good heat resistance and are therefore suitable as adhesives for use in, for example, electronic circuit boards and semiconductor devices.

[0086] The glass transition temperature of the polyimide film can be measured by the following method. The obtained polyimide film is cut into a size of 5 mm in width and 22 mm in length. The glass transition temperature (Tg) of the obtained sample is measured by a thermal analyzer (e.g., TMA-50 manufactured by Shimadzu Corporation). Specifically, the measurement is performed under conditions of an air atmosphere, a temperature rise rate of 5°C / min, and a tensile mode (100 mN) to obtain a TMA curve, and the value of the glass transition temperature (Tg) can be obtained by extrapolating the curves before and after the inflection point of the TMA curve due to the glass transition.

[0087] (5% weight loss temperature (T d5 )) The 5% weight loss temperature (T d5 From the same viewpoint as above, the T of the polyimide film is preferably 300° C. or more, and more preferably 320° C. or more. d5 The upper limit of the temperature is not particularly limited, but can be, for example, 600°C or 500°C.

[0088] Tg and T of polyimide film d5 can be adjusted by the monomer composition of the polyamic acid. For example, the Tg and T d5 It can increase.

[0089] (2)Resolubility The polyimide film obtained by imidizing polyamic acid preferably has high solubility in a solvent, for example, from the viewpoint of dissolving in a solvent and facilitating peeling when used as an adhesive. Specifically, the polyimide film obtained by imidizing polyamic acid is immersed in N-methyl-2-pyrrolidone at 80° C. for 3 minutes, and then filtered through a filter paper to measure the dissolution rate represented by the following formula (1) is preferably 85% or more, more preferably 90% or more. Equation (1): Dissolution rate (%) = [1 - [(weight of filter paper after filtration and drying) - (weight of filter paper before use)] / (weight of film before immersion)] x 100

[0090] The re-dissolution property can be measured by the following procedure. 1) The polyimide film obtained by imidizing the polyamic acid composition is cut into a sample having a thickness of 20 μm and a size of 2.0 cm × 2.0 cm, and the weight (weight of the film before immersion) is measured in advance. As described above, the imidization conditions are that the temperature rise rate in the temperature range of 50 to 200 ° C. in an air atmosphere is preferably 0.25 to 30 ° C. / min, more preferably 1 to 20 ° C. / min, and even more preferably 2 to 10 ° C. / min, and heating is performed in the temperature range of 50 to 200 ° C. for 30 minutes. The preferred imidization conditions are to raise the temperature from 50 ° C. to 200 ° C. at 5 ° C. / min in an air atmosphere, and to heat at 200 ° C. for 30 minutes. The weight of the filter paper before use is also measured in advance. 2) Next, the sample is added to N-methyl-2-pyrrolidone (NMP) to a concentration of 1% by mass to prepare a sample liquid, and the obtained sample liquid is left to stand in an oven heated to 80°C for 3 minutes. The sample liquid is then removed from the oven, filtered through filter paper, and dried under reduced pressure at 100°C. The weight of the filter paper after filtration and drying is then measured. 3) The measured values ​​of 1) and 2) above are substituted into the above formula (1) to calculate the dissolution rate. These operations (operations 1) to 3) above) are carried out for n=2, and the average value is taken as the dissolution rate (%). The size (thickness, etc.) of the sample is preferably as described above, but may be slightly different.

[0091] The resolubility of the polyimide film can be adjusted by the type and composition of the molecular end group of the polyamic acid, which is the precursor of the polyimide film. For example, by making the molecular end group of the polyamic acid an acid anhydride group, the resolubility of the resulting polyimide is likely to be increased. In addition, the resolubility of the resulting polyimide is likely to be increased by increasing the content of the monomer (A) having a diphenyl ether skeleton but not a benzophenone skeleton (particularly the content of the aromatic tetracarboxylic dianhydride (α1) having a diphenyl ether skeleton but not a benzophenone skeleton) as a monomer constituting the polyamic acid, reducing the content of the monomer (B) having a benzophenone skeleton as much as possible, or increasing the content of the aliphatic diamine (β2) represented by the general formula (3) or (4).

[0092] (3) Mechanical properties (elongation) When the polyamic acid is imidized to form a film having a thickness of 20 μm, the elongation at 23° C. is preferably 40% or more, more preferably 55% or more, even more preferably 80% or more, and particularly preferably 130% or more.

[0093] The elongation of the polyimide film can be measured by the following method. Figure 1 is a schematic diagram showing a test piece used in a tensile break test. 1) First, the polyimide film is punched into dumbbell shapes as shown in Figure 1 to obtain sample films of A: 50 mm, B: 10 mm, C: 20 mm, and D: 5 mm. 2) Next, the sample film is set in a tensile testing machine EZ-S (manufactured by Shimadzu Corporation) and pulled in the length direction (direction A) at 23° C. with a speed of 50 mm / min and a chuck distance of 30 mm. Then, the "tensile elongation at break" can be calculated as (length of sample film at break - original length of sample film) / (original length of sample film) x 100 (%).

[0094] The elongation of the polyimide film can be adjusted by the composition of the polyimide. For example, by increasing the content of the monomer (A) that does not have a benzophenone skeleton but has a diphenyl ether skeleton (particularly the content of the aromatic tetracarboxylic dianhydride (α1) that does not have a benzophenone skeleton but has a diphenyl ether skeleton) constituting the polyimide, or by increasing the content of the aliphatic diamine (β2) represented by the general formula (3) or (4), the flexibility of the obtained polyimide film is increased and the elongation is also likely to increase.

[0095] 3. Uses of polyimide compositions The polyamic acid composition of the present disclosure can provide a polyimide having high resolubility while having high heat resistance and mechanical properties. Therefore, the polyimide composition obtained from the polyamic acid composition of the present disclosure can be used as an adhesive, a sealant, an insulating material, a substrate material, or a protective material in applications that particularly require heat resistance and resolubility, such as electronic circuit board members, semiconductor devices, and surge components.

[0096] That is, a laminate having a substrate and a resin layer containing the polyimide composition of the present disclosure disposed thereon can be used. Preferably, a laminate having a substrate and a resin layer containing the polyimide composition of the present disclosure disposed on the substrate in contact with the substrate. The material constituting the substrate is not particularly limited, and may be any material that is commonly used. That is, the material constituting the substrate may be, for example, silicon, ceramics, metal, or resin, depending on the application. Examples of metals include silicon, copper, aluminum, SUS, iron, magnesium, nickel, and alumina. Examples of resins include urethane resin, epoxy resin, acrylic resin, polyimide, PET resin, polyamide, polyamideimide, and the like. The substrate more preferably contains at least one element selected from the group consisting of Si, Ga, Ge, and As, and more preferably is a semiconductor substrate (semiconductor chip, semiconductor wafer, etc.) containing at least one element selected from the group consisting of Si, Ga, Ge, and As.

[0097] The laminate can be produced, for example, by applying the polyamic acid composition of the present disclosure onto a substrate, and then heating the composition to imidize the composition, thereby forming a resin layer made of the polyimide composition. The heating temperature of the coating film can be set to a temperature suitable for imidization, as described above.

[0098] Electronic circuit board components The polyimide composition of the present disclosure can be used as an insulating substrate or adhesive in a circuit board, particularly a flexible circuit board. For example, the flexible circuit board can have a metal foil (substrate) and an insulating layer made of the polyimide composition of the present disclosure (obtained from the polyamic acid composition of the present disclosure) disposed thereon. The flexible circuit board can also have an insulating resin film (substrate), an adhesive layer made of the polyimide composition of the present disclosure, and a metal foil.

[0099] Semiconductor materials The polyimide composition of the present disclosure can be used as an adhesive for bonding semiconductor chips together or between a semiconductor chip and a substrate, a protective material for protecting the circuits of a semiconductor chip, an embedding material (encapsulant) for embedding a semiconductor chip, and the like.

[0100] That is, the semiconductor member of the present disclosure has a semiconductor chip (substrate) and a resin layer made of the polyimide composition of the present disclosure (obtained from the polyamic acid composition of the present disclosure) disposed on at least one surface of the semiconductor chip. The semiconductor chip includes diodes, transistors, integrated circuits (ICs), and the like, and also includes power elements. The resin layer made of the polyimide composition may be disposed on the surface of the semiconductor chip on which terminals are formed (terminal forming surface), or on a surface different from the terminal forming surface.

[0101] The thickness of the layer made of the polyimide composition is preferably about 1 to 100 μm when the polyimide composition is used as an adhesive layer, and about 2 to 200 μm when the polyimide composition layer is used as a circuit protection layer.

[0102] Adhesive for surge components The polyimide composition of the present disclosure can be used as an adhesive or a sealant for surge components (surge absorbers) for protecting home appliances, personal computers, transportation equipment such as automobiles, mobile devices, power sources, servers, telephones, etc. from abnormal currents and voltages that affect them. By using the polyimide composition of the present disclosure as an adhesive or sealant, it is possible to bond or seal surge components at low temperatures, and the voltage resistance and heat resistance are also sufficient.

[0103] Among these, the polyimide composition of the present disclosure has heat resistance and mechanical properties (elongation) and is excellent in resolubility, and is therefore preferably used as an adhesive for electronic circuit board members, semiconductor members, surge components, and the like; in particular, an adhesive for semiconductor members, an adhesive for flexible printed circuit boards, an adhesive for coverlay films, or an adhesive for bonding sheets.

[0104] That is, electronic devices such as electronic circuit boards and semiconductor members may be manufactured through the steps of preparing a laminate having a substrate, a resin layer, and a handling substrate, processing the substrate, dissolving the resin layer in a solvent, and peeling the processed substrate (processed product) from the handling substrate. The laminate can be obtained, for example, by applying the polyamic acid composition of the present disclosure to one of the substrate and the handling substrate, imidizing the substrate to form a layer containing the polyimide composition, and then laminating the other substrate.

[0105] FIG. 2 is a schematic cross-sectional view showing an example of a process for processing a silicon substrate using the polyimide composition of the present disclosure as a temporary fixing adhesive. As shown in FIG. 2, for example, the polyamic acid resin composition of the present disclosure is applied onto a silicon substrate 10 (substrate), and then heated and imidized to form a resin layer 20 containing the polyimide resin composition (see FIG. 2A). Next, a handling substrate 30 (for example, a glass substrate) is placed on the resin layer 20, and a laminate is obtained by thermocompression bonding with a heat press machine 40 (see FIG. 2B). Next, the back surface of the silicon substrate 10 is polished to a predetermined thickness (see FIG. 2C). Next, a resist 50 is placed on the polished silicon substrate 10 to form a resist pattern 50' (see FIG. 2E), and the silicon substrate 10 is etched and patterned along the resist pattern 50' (see FIG. 2F). Next, the handling substrate 30 is peeled off from the resin layer 20 by laser or mechanical processing (see FIG. 2G). Then, the resin layer 20 is dissolved in a solvent, and the patterned silicon substrate 10' is peeled off to obtain the silicon substrate 10' (see FIG. 2H). In this process, the silicon substrate 10 is exposed to high temperatures of 200° C. or more, for example, in a step of polishing the back surface of the silicon substrate 10 (see FIG. 2C) and a step of etching and heat-treating the silicon substrate 10 (see FIG. 2F).

[0106] Thus, in the manufacturing process of electronic circuit boards, semiconductor members, etc., after processing a substrate fixed on a handling substrate via an upper resin layer (including, for example, a polishing process, an etching / heat treatment process, an electrode film formation process, a rewiring process, and other heating processes), the substrate may be peeled off from the processed product together with the adhesive without leaving any adhesive residue. In contrast, the polyimide composition of the present disclosure (obtained from the polyamic acid composition of the present disclosure) has heat resistance that can withstand the heating process and can be dissolved by a solvent, etc., so that it can be peeled off without leaving any adhesive residue. Therefore, the polyimide composition of the present disclosure is suitable as an adhesive for electronic circuit boards, semiconductor members, etc., and is particularly suitable as a temporary fixing adhesive (an adhesive that is peeled off after being bonded once). EXAMPLES

[0107] The present disclosure will be described in more detail below with reference to examples. However, the scope of the present disclosure is not limited thereby. The acid anhydrides and diamines used in the examples and comparative examples are shown below.

[0108] (1) Acid dianhydride 1) Aromatic tetracarboxylic dianhydride (α1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (1) ODPA: 4,4'-oxydiphthalic anhydride 2) Aromatic tetracarboxylic dianhydrides with a biphenyl skeleton (α2) s-BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride (manufactured by JFE Chemical Corporation) 3) Aromatic tetracarboxylic dianhydrides having a benzophenone skeleton (α3) BTDA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride

[0109] (2) Diamine 1) Aromatic diamine (β1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (2) p-BAPP: 2,2-bis(4-(4-aminophenoxy)phenyl)propane APB-N: 1,3-bis(3-aminophenoxy)benzene (Mitsui Chemicals) 2) Aliphatic diamine (β2) represented by general formula (3) or (4) RT1000: Polyetheramine (HUNTSMAN, see formula below, Mw=1015) [ka] Elasmer 1000P: Polyether diamine (manufactured by Ihara Chemical Co., Ltd., amine value 80 to 90, see formula below, Mw = 1268) [ka] D230: Polyoxypropylenediamine (Mitsui Fine Chemicals, Mw=230) D2000: Polyoxypropylenediamine (Mitsui Fine Chemicals, Mw=2000)

[0110] Example 1 Preparation of polyamic acid varnish (polyamic acid composition) Two types of acid dianhydrides (s-BPDA, ODPA) and two types of diamines (pBAPP, RT1000) were mixed in a molar ratio of s-BPDA:ODPA:pBAPP, RT1000 = 0.5:0.5:0.706:0.274 in a solvent prepared with NMP (N-methylpyrrolidone). The resulting mixture was stirred at 40°C for 4 hours or more in a flask into which dry nitrogen gas could be introduced, to obtain a polyamic acid varnish with a resin solid content of 20 to 25% by mass.

[0111] Film preparation The obtained polyamic acid varnish was applied onto a glass plate at a speed of 10 mm / sec, and then heated from 50° C. to 200° C. at a rate of 5° C. / min, and heated at 200° C. for 30 minutes to remove the solvent and perform imidization. The obtained polyimide film was peeled off from the glass plate to obtain a polyimide film (polyimide composition) having a thickness of 20 μm.

[0112] (Examples 2 to 10, Comparative Examples 1 to 2) Polyamic acid varnishes were prepared in the same manner as in Example 1, except that the types and amount ratios of the acid dianhydrides and diamines, and the molar ratio of diamine / acid dianhydride were changed as shown in Table 1, and polyimide films were obtained.

[0113] Comparative Example 3 Preparation of polyimide varnish (polyimide composition) Two types of acid dianhydrides (s-BPDA, BTDA) and three types of diamines (pBAPP, RT1000, 1000P) were mixed in a solvent prepared with NMP (N-methylpyrrolidone) and PQ (1,2,4-trimethylbenzene) in a mass ratio of NMP:PQ = 8:2, with a molar ratio of s-BPDA:BTDA:pBAPP, RT1000, 1000P = 0.76:0.2:0.8:0.1:0.1. The resulting mixture was stirred at 40 ° C for 5 hours or more in a flask equipped with a Dean-Stark and condenser that can introduce dry nitrogen gas, to obtain a polyamic acid varnish. The solution temperature was then raised and stirred at an internal temperature of 190 ° C for 8 hours or more. At this time, the distilled condensation water and partially volatilized NMP and PQ were collected with a Dean-Stark. After the reaction was completed, NMP was added to adjust the concentration, and a pale yellow viscous polyimide varnish was obtained.

[0114] Film preparation The obtained polyimide varnish was applied onto a glass plate at a speed of 10 mm / sec, and then the temperature was raised from 50°C to 200°C at a rate of 5°C / min. The film was then heated at 200°C for 30 minutes to remove the solvent. In the same manner as in Example 1, a polyimide film (polyimide composition) having a thickness of 20 μm was obtained, except that the solvent was removed.

[0115] (evaluation) The intrinsic viscosities of the polyamic acid varnishes used in Examples 1 to 10 and Comparative Examples 1 and 2, and the polyimide varnish used in Comparative Example 3 were measured by the following method.

[0116] (1) Intrinsic viscosity η The obtained polyamic acid varnish or polyimide varnish was diluted with NMP so that the concentration of polyamic acid or polyimide was 0.5 g / dL, and the intrinsic viscosity η of the solution was measured three times at 25°C using an Ubbelohde viscometer (size number 1) in accordance with JIS K7367-1:2002, and the average value was used.

[0117] The polyimide films obtained in Examples 1 to 10 and Comparative Examples 1 to 3 were evaluated for (2) resolubility, (3) heat resistance, and (4) elongation by the following methods. The molar ratio (b / a) of diamine to tetracarboxylic dianhydride was calculated from the amounts (moles) of diamine and tetracarboxylic dianhydride charged.

[0118] (2)Resolubility 1) The obtained polyimide film was cut into a sample of 2.0 cm x 2.0 cm, and its weight (weight of the film before immersion) was measured in advance. The weight of the filter paper before use was also measured in advance. 2) Next, the sample was added to N-methyl-2-pyrrolidone (an amount such that the sample was 1% by mass, 5-7 mL in this case) to prepare a sample liquid, and the obtained sample liquid was left to stand in an oven heated to 80°C for 3 minutes. After that, the sample liquid was removed from the oven and filtered through filter paper (mesh size: 5B), and then dried under reduced pressure at 100°C. The weight of the filter paper after filtration and drying was then measured. 3) The measured values ​​of 1) and 2) above were applied to the following formula (1) to calculate the dissolution rate. These operations (operations 1) to 3) above) were performed on n=2, and the average value was taken as the dissolution rate (%). Equation (1): Dissolution rate (%) = [1 - [(weight of filter paper after filtration and drying) - (weight of filter paper before use)] / (weight of film before immersion)] x 100

[0119] (3) Thermophysical properties (Glass transition temperature (Tg)) The obtained polyimide film was cut into a width of 5 mm and a length of 22 mm. The glass transition temperature (Tg) of the sample was measured using a thermal analyzer (TMA-50) manufactured by Shimadzu Corporation. Specifically, the measurement was performed under conditions of an air atmosphere (air gas 50 mL / min), a temperature rise rate of 5°C / min, and a tensile mode (100 mN) to obtain a TMA curve, and the glass transition temperature (Tg) value was obtained by extrapolating the curves before and after the inflection point of the TMA curve due to the glass transition.

[0120] (5% weight loss temperature (T d5 )) The 5% weight loss temperature (T d5 ) was measured using a thermogravimetric analyzer (TGA-60) manufactured by Shimadzu Corporation. Specifically, the obtained polyimide film (approximate weight: about 5 mg) was accurately weighed on the apparatus, the scanning temperature was set to 30 to 900°C, and the film was heated at a temperature increase rate of 10°C / min while air gas was flowing at 50 mL / min in an atmospheric environment. The temperature at which the mass of the sample decreased by 5% was determined as T d5 It was decided.

[0121] (4) Mechanical properties (Elongation at break) The obtained polyimide film was punched out into dumbbell shapes as shown in FIG. 1 to obtain sample films of A: 50 mm, B: 10 mm, C: 20 mm, and D: 5 mm. The obtained sample film was set in a tensile testing machine EZ-S (manufactured by Shimadzu Corporation) and pulled in the length direction (direction A) at a speed of 50 mm / min and a chuck distance of 30 mm at 23° C. Then, (length of sample film at break-original length of sample film) / (original length of sample film) was defined as the "tensile elongation at break," and the tensile elongation of the sample film at break was evaluated according to the following criteria. ○: Tensile elongation at break is 40% or more ×: Elongation at break is less than 40%

[0122] The evaluation results of Examples 1 to 10 and Comparative Examples 1 to 3 are shown in Table 1.

[0123] [Table 1]

[0124] As shown in Table 1, the polyimide films obtained using the polyamic acid varnishes of Examples 1 to 10 have good thermal properties (Tg, T d5 ) and mechanical properties (elongation), while exhibiting excellent re-solubility.

[0125] In particular, it is found that by adjusting the Mw of the aliphatic diamine (β2) to more than 230 and less than 2000, the balance between the resolubility and the thermal and mechanical properties is further improved (comparison of Examples 1, 4, and 5).

[0126] In addition, it can be seen that when the content of the aromatic tetracarboxylic dianhydride (α1) having a diphenyl ether skeleton is 30 mol % or more based on the total amount of the tetracarboxylic dianhydrides, the re-solubility is further improved (comparison between Examples 8 and 9).

[0127] In contrast, it is found that the polyimide films obtained from the polyamic acid varnish of Comparative Example 1 and the polyimide varnish of Comparative Example 3, in which the diamine / acid dianhydride molar ratio exceeds 1, have low resolubility. It is also found that the polyimide film obtained from the polyamic acid varnish of Comparative Example 2, which contains the monomer (B) having a benzophenone skeleton (containing 10 mol % of all monomers), also has low resolubility.

[0128] This application claims priority based on Japanese Patent Application No. 2021-047434, filed on March 22, 2021. The entire contents of the specification of that application are incorporated herein by reference. [Industrial Applicability]

[0129] The polyamic acid composition of the present disclosure can provide a polyimide film having both high heat resistance and mechanical properties (elongation) and excellent resolubility. Therefore, the obtained polyimide film is suitable as an adhesive in various fields requiring high heat resistance, flexibility, and resolubility, such as electronic circuit board members and semiconductor devices. [Explanation of symbols]

[0130] 10 Silicon substrate 10' Patterned silicon substrate 20 Resin layer 30 Handling Board 40 Heat press machine 50 Resist 50' Resist Pattern

Claims

1. A polyamic acid obtained by polycondensation of a tetracarboxylic dianhydride monomer and a diamine monomer, The monomer constituting the polyamic acid is With respect to the total of the monomers constituting the polyamic acid 30 to 97 mol % of a monomer (A) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (1) or (2), A monomer (B) having a benzophenone skeleton is 0 to 5 mol %; Including, The diamine constituting the polyamic acid is An aromatic diamine (β1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (2), An aliphatic diamine (β2) represented by general formula (3) or (4) Including, The aromatic diamine (β1) is a diamine represented by formula (2-1): and the content of the aromatic diamine (β1) is 65 mol % or more and 95 mol % or less based on the total diamines, A polyamic acid, wherein the molar ratio of diamine and tetracarboxylic dianhydride constituting the polyamic acid is diamine / tetracarboxylic dianhydride=0.90 to 0.999; Including, Polyamic acid composition. 【Chemistry 1】 【Chemistry 2】 (In general formula (3), R １ is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 7 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, or O, and the total number of atoms constituting the side chain is 10 or less. 【Chemistry 3】 (In general formula (4), R ２ is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 5 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, or O, and the total number of atoms constituting the side chain is 10 or less. 【Chemistry 4】 (In general formula (2-1), Z represents a divalent group selected from the group consisting of an oxygen atom, a sulfur atom, a sulfone group, a methylene group, a fluorene structure, and -CR1R2- (R1 and R2 each represent a substituted or unsubstituted alkyl group or phenyl group having 1 to 3 carbon atoms); R 1 and R 2 may be bonded to each other to form a ring.

2. The tetracarboxylic dianhydride constituting the polyamic acid does not have a benzophenone skeleton and contains an aromatic tetracarboxylic dianhydride (α1) having a diphenyl ether skeleton represented by general formula (1) or (2), The aromatic tetracarboxylic dianhydride (α1) is a compound represented by general formula (5): The polyamic acid composition of claim 1 . 【Chemistry 5】 (In general formula (5), X is an arylene group having 6 to 10 carbon atoms or a group represented by the following formula (a): n represents 0 or 1. 【Chemistry 6】 (In the above formula (a), Y is an oxygen atom, a sulfur atom, a sulfone group, a methylene group, a fluorene structure, -CR １ R ２ - (R １ and R ２ represents a divalent group selected from the group consisting of a substituted or unsubstituted alkyl group or a phenyl group having 1 to 3 carbon atoms, R １ and R ２ may be bonded to each other to form a ring)

3. In the general formula (5), n is 0. The polyamic acid composition of claim 2.

4. The content of the aromatic tetracarboxylic dianhydride (α1) is 30 mol % or more based on the total amount of the tetracarboxylic dianhydrides constituting the polyamic acid. The polyamic acid composition according to claim 2 or 3.

5. R in the above general formula (3) １ and R in the general formula (4) ２ is an aliphatic chain having a main chain containing an alkyleneoxy group or a polyalkyleneoxy group, the alkylene moiety of the alkyleneoxy group and the alkylene moiety of the alkyleneoxy unit constituting the polyalkyleneoxy group each have 1 to 10 carbon atoms; The polyamic acid composition according to any one of claims 1 to 4.

6. The aliphatic diamine (β2) represented by the general formula (3) is a compound represented by the following general formula (3-1): The aliphatic diamine (β2) represented by the general formula (4) is a compound represented by the following general formula (4-1): The polyamic acid composition according to any one of claims 1 to 5. 【Chemistry 7】 (In the general formula (3-1), o represents an integer of 1 to 50.) 【Chemistry 8】 In the general formula (4-1), p, q, and r each independently represent an integer of 0 to 10; provided that p+q+r is 1 or more.

7. The weight average molecular weight of the aliphatic diamine represented by the general formula (3) or the aliphatic diamine (β2) represented by the general formula (4) is 100 to 5000. The polyamic acid composition according to any one of claims 1 to 6.

8. The content of the aliphatic diamine represented by the general formula (3) or the aliphatic diamine (β2) represented by the general formula (4) is 10 to 45 mol % based on the total amount of diamines constituting the polyamic acid. The polyamic acid composition according to any one of claims 1 to 7.

9. The monomer (A) and the aromatic diamine (β1) do not have a biphenyl skeleton. The polyamic acid composition according to any one of claims 1 to 8.

10. The monomer constituting the polyamic acid is The polyamic acid further contains a monomer (C) having a biphenyl skeleton in an amount of 50 mol% or less based on the total amount of monomers constituting the polyamic acid. The polyamic acid composition of claim 9.

11. Further comprising a solvent, The polyamic acid composition according to any one of claims 1 to 10.

12. The solvent includes at least one selected from the group consisting of aprotic solvents and alcohol solvents. The polyamic acid composition of claim 11.

13. The polyimide film obtained by imidizing the polyamic acid composition has a glass transition temperature of 95° C. or higher and lower than 260° C. The polyamic acid composition according to any one of claims 1 to 12.

14. When the polyamic acid composition is imidized to form a film of 2.0 cm × 2.0 cm × 20 μm thickness, the film is immersed in N-methyl-2-pyrrolidone at 80° C. for 3 minutes, and then filtered through a filter paper. The dissolution rate, which is measured by the following formula (1), is 85% or more. The polyamic acid composition according to any one of claims 1 to 13. Formula (1): Dissolution rate (%) = [1 - [(weight of filter paper after filtration and drying) - (weight of filter paper before use)] / (weight of film before immersion)] x 100

15. The polyimide film obtained by imidizing the polyamic acid composition has a 5% weight loss temperature in the air of 300° C. or higher. The polyamic acid composition according to any one of claims 1 to 14.

16. When the polyamic acid composition is imidized to form a film having a thickness of 20 μm, the elongation at 23° C. is 40% or more. The polyamic acid composition according to any one of claims 1 to 15.

17. A polyimide obtained by polycondensation of a tetracarboxylic dianhydride monomer and a diamine monomer, The monomer constituting the polyimide is With respect to the total of the monomers constituting the polyimide 30 to 97 mol % of a monomer (A) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (1) or (2), A monomer (B) having a benzophenone skeleton is 0 to 5 mol %; Including, The diamine constituting the polyimide is An aromatic diamine (β1) having no benzophenone skeleton and having a diphenyl ether skeleton represented by general formula (2), and an aliphatic diamine (β2) represented by general formula (3) or (4), The aromatic diamine (β1) is a diamine represented by formula (2-1): and the content of the aromatic diamine (β1) is 65 mol % or more and 95 mol % or less based on the total diamines, a molar ratio of the diamine and the tetracarboxylic dianhydride constituting the polyimide is diamine / tetracarboxylic dianhydride=0.90 to 0.999; Including, Polyimide composition. 【Chemistry 9】 【Chemistry 10】 (In general formula (3), R １ is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 7 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, or O, and the total number of atoms constituting the side chain is 10 or less. 【Chemistry 11】 (In general formula (4), R ２ is an aliphatic chain having a main chain composed of one or more atoms of C, N, and O, and the total number of atoms constituting the main chain is 5 to 500; The aliphatic chain may further have a side chain consisting of one or more atoms of C, N, H, or O, and the total number of atoms constituting the side chain is 10 or less. 【Chemistry 12】 (In general formula (2-1), Z represents a divalent group selected from the group consisting of an oxygen atom, a sulfur atom, a sulfone group, a methylene group, a fluorene structure, and -CR1R2- (R1 and R2 each represent a substituted or unsubstituted alkyl group or phenyl group having 1 to 3 carbon atoms); R 1 and R 2 may be bonded to each other to form a ring.

18. The monomer (A) and the aromatic diamine (β1) do not have a biphenyl skeleton.

18. The polyimide composition of claim 17.

19. The polyimide composition of claim 17, glue.

20. The adhesive is an adhesive for semiconductor members, an adhesive for flexible printed circuit boards, an adhesive for coverlay films, or an adhesive for bonding sheets; 20. The adhesive of claim 19.

21. A substrate; A resin layer comprising the polyimide composition according to claim 17 disposed on the substrate; A laminate having

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