Imide-amide acid copolymer and method of preparation thereof, varnish, and polyimide film

Abstract

An imide-amid acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the following formula (1). (In formula (1), X1 is a tetravalent aromatic group having 4 to 39 carbon atoms, X2 is a tetravalent aromatic group having 4 to 39 carbon atoms different from X1, Y1 is a group derived from diaminodiphenylsulfone, etc., Y2 is a group derived from 4-aminophenyl-4-aminobenzoate, etc., and s, t, and u are positive integers.)

Description

Technology Field

[0001] The present invention relates to an imide-amide acid copolymer which is a precursor of a polyimide resin, a method for manufacturing the same, a varnish comprising the copolymer, and a polyimide film. Background Technology

[0002] Polyimide resins are being considered for various applications in fields such as electrical and electronic components. For example, there is a demand to replace glass substrates used in image display devices, such as liquid crystal displays or OLED displays, with plastic substrates for the purpose of making the devices lighter or more flexible, and research is being conducted on polyimide films suitable as such plastic substrates. Polyimide films for such applications require transparency and low yellowness.

[0003] Furthermore, when a polyimide film is formed by heat-curing a varnish applied to a glass support or silicon wafer, residual stress occurs in the polyimide film. Since high residual stress in the polyimide film causes the glass support or silicon wafer to warp, a reduction in residual stress is also required for the polyimide film.

[0004] Regarding this point, for example, Patent Document 1 discloses a polyimide precursor characterized by containing two types of specific amide acid structural units in a specific ratio, for the purpose of obtaining a polyimide film having low residual stress, low bending, low yellowness, and high elongation. Prior art literature

[0005] International Publication No. 2017 / 051827 The problem to be solved

[0006] As described above, transparency and low yellowness are required for polyimide films for specific applications. However, in the case of LTPS (low-temperature polysilicon TFT) as the device type of TFT, the process temperature exceeds 400°C, and the polyimide substrate requires heat resistance to withstand high temperatures of 400°C or higher, and it is required to maintain transparency and low yellowness even under such thermal history.

[0007] In addition, as mentioned above, it is also required to reduce residual stress due to the problem of bending of the support. Furthermore, it is also necessary to reduce the coefficient of linear thermal expansion because there is a concern about delamination at the bonding surface or deformation of the product due to the difference in the coefficient of linear thermal expansion with the inorganic layer constituting the device.

[0008] Patent Document 1 discloses a technology for reducing residual stress and yellowness, but it is still insufficient, and in particular, a polyimide film with excellent heat resistance, etc., while maintaining transparency and low yellowness has not been obtained.

[0009] The present invention has been made in consideration of these circumstances, and the objective of the present invention is to provide an imide-amide acid copolymer, which is a precursor of a polyimide resin, and a method for manufacturing the same, a varnish containing the copolymer, and a polyimide film, which can be obtained with low residual stress and a coefficient of linear thermal expansion, excellent transparency and heat resistance, and low yellowness. means of solving the problem

[0010] The inventors have discovered that a copolymer comprising a combination of specific constituent units can solve the above problem, and have thus completed the invention.

[0011] That is, the present invention relates to [1] to

[18] below.

[0012] [1] An imide-amid acid copolymer comprising repeating units consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the following formula (1).

[0013] [Chemical Formula 1]

[0014]

[0015] (In the formula (1),

[0016] X 1 It may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, as a tetravalent aromatic group having 4 to 39 carbon atoms.

[0017] X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and

[0018] Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and

[0019] Y 2 is a device represented by the following general formula (5),

[0020] s, t, and u are positive integers.

[0021] [Chemical Formula 2]

[0022]

[0023] (Equation (3), Z 1 It represents a single bond, or a group denoted by -O-.

[0024] In formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0025] [Chemical Formula 3]

[0026]

[0027] (Equation (5), Z2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0028] [2] The imide-amide acid copolymer described in [1], wherein s is 1 to 50 and t is 1 to 50.

[0029] [3] The imid-amide acid copolymer described in [1] or [2], wherein u is 5 to 200.

[0030] [4] The above X 1 This is an imid-amide acid copolymer, represented by the following formula (6), described in any one of [1] to [3] above.

[0031] [Chemical Formula 4]

[0032]

[0033] [5] The above X 2 A, an imid-amide acid copolymer represented by the following formula (7), described in any one of [1] to [4] above.

[0034] [Chemical Formula 5]

[0035]

[0036] [6] The above imide portion (IM) has a constituent unit X1A derived from tetracarboxylic acid dianhydride and a constituent unit Y1B derived from diamine, and

[0037] The above-mentioned amide acid portion (AM1) has a constituent unit X2A derived from tetracarboxylic acid dianhydride and a constituent unit Y1B derived from diamine, and

[0038] The above-mentioned amide acid portion (AM2) has a constituent unit X2A derived from tetracarboxylic acid dianhydride and a constituent unit Y2B derived from diamine, and

[0039] Constituent unit X1A comprises a constituent unit derived from an aromatic tetracarboxylic acid dianhydride, and

[0040] Constituent unit X2A comprises a constituent unit derived from an aromatic tetracarboxylic acid dianhydride different from constituent unit X1A, and

[0041] The constituent unit Y1B comprises a constituent unit (B1) derived from a diamine (b1), and the constituent unit (B1) comprises at least one selected from the group consisting of a constituent unit (B11) derived from a compound represented by the following formula (b11), a constituent unit (B12) derived from a compound represented by the following general formula (b12), and a constituent unit (B13) derived from a compound represented by the following general formula (b13).

[0042] An imid-amide acid copolymer described in any one of [1] to [5], comprising a constituent unit (B2) derived from a compound represented by the following general formula (b2), wherein the constituent unit Y2B is represented by the following general formula (b2).

[0043] [Chemical Formula 6]

[0044]

[0045] (Equation (b12), Z 1 It represents a single bond, or a group denoted by -O-.

[0046] In formula (b13), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0047] In equation (b2), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0048] [7] The constituent unit X2A comprises a constituent unit (A2) derived from an aromatic tetracarboxylic acid dianhydride (a2), and

[0049] The imide-amid acid copolymer described in [6] comprises at least one constituent unit (A2) selected from the group consisting of a constituent unit (A21) derived from a compound represented by the following formula (a21), a constituent unit (A22) derived from a compound represented by the following formula (a22), a constituent unit (A23) derived from a compound represented by the following formula (a23), a constituent unit (A24) derived from a compound represented by the following formula (a24), and a constituent unit (A25) derived from a compound represented by the following formula (a25).

[0050] [Chemical Formula 7]

[0051]

[0052] [8] An imid-amide acid copolymer described in [6] or [7], further comprising a constituent unit (B3) derived from a compound represented by the general formula (b3) below.

[0053] [Chemical Formula 8]

[0054]

[0055] (Equation (b3), Z 4 and Z 5 Each independently represents a divalent aliphatic group or a divalent aromatic group, and R 4 and R 5 Each independently represents a monovalent aromatic group or a monovalent aliphatic group, and R 6 and R 7 Each independently represents a monovalent aliphatic group, and R 8 and R 9 , each independently represents a monovalent aliphatic group or a monovalent aromatic group, m and n each independently represent an integer greater than or equal to 1, and the sum of m and n represents an integer between 2 and 1000. provided that R 4 and R 5At least one of the groups represents a monovalent aromatic group.)

[0056] [9] The above R 4 and R 5 a, is a phenyl group, and R 6 and R 7 This is the imid-amide acid copolymer described in [8] above, which is a methyl group.

[0057]

[10] An imid-amide acid copolymer described in [8] or [9], wherein the content of polyorganosiloxane units in the imid-amide acid copolymer is 1 to 20 mass%.

[0058]

[11] An imid-amide acid copolymer described in any one of [6] to

[10] , wherein the constituent unit X1A comprises a constituent unit (A1) derived from a compound represented by the following formula (a1).

[0059] [Chemical Formula 9]

[0060]

[0061]

[12] A varnish formed by dissolving the copolymer described in any one of [1] to

[11] above in an organic solvent.

[0062]

[13] A polyimide film comprising a polyimide resin formed by imidizing the amide acid portion of the copolymer described in any one of [1] to

[11] above.

[0063]

[14] Polyimide film described in

[13] , wherein the weight-average molecular weight (Mw) of the polyimide resin is 100,000 to 300,000.

[0064]

[15] A method for manufacturing an imide-amide acid copolymer having the following process 1 and process 2.

[0065] Process 1: A process of obtaining an imide oligomer by reacting the tetracarboxylic acid component constituting the imide portion (IM) with the diamine component.

[0066] Process 2: A process of reacting the imide oligomer obtained in Process 1 with a tetracarboxylic acid component and a diamine component constituting the amic acid portion (AM2) to obtain an imide-amic acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amic acid portion (AM1), and an amic acid portion (AM2), represented by the following formula (1).

[0067] [Chemical Formula 10]

[0068]

[0069] (In the formula (1),

[0070] X 1 It may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, as a tetravalent aromatic group having 4 to 39 carbon atoms.

[0071] X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and

[0072] Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and

[0073] Y 2 is a device represented by the following general formula (5),

[0074] s, t, and u are positive integers.

[0075] [Chemical Formula 11]

[0076]

[0077] (Equation (3), Z 1 It represents a single bond, or a group denoted by -O-.

[0078] In formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0079] [Chemical Formula 12]

[0080]

[0081] (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0082]

[16] A method for preparing an imide-amide acid copolymer as described in

[15] , wherein the imide oligomer obtained in process 1 has amino groups at both ends of the main chain of the molecular chain.

[0083]

[17] A method for preparing an imide-amide acid copolymer as described in

[15] or

[16] , wherein in process 1, the molar ratio of the diamine component to the tetracarboxylic acid component (diamine / tetracarboxylic acid) is 1.01 to 2.

[0084]

[18] A method for preparing an imid-amide acid copolymer as described in any one of

[15] to

[17] , wherein a diamine containing polyorganosiloxane units is reacted after the completion of process 2. Effects of the invention

[0085] According to the present invention, an imide-amide acid copolymer which is a precursor of a polyimide resin and a method for manufacturing the same, a varnish comprising the copolymer, and a polyimide film can be provided, which can obtain a polyimide film having low residual stress and a coefficient of linear thermal expansion, excellent transparency and heat resistance, and low yellowness. Specific details for implementing the invention

[0086] [Imide-Amidic Acid Copolymer]

[0087] The imide-amid acid copolymer of the present invention comprises a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the following formula (1).

[0088] [Chemical Formula 13]

[0089]

[0090] (In the formula (1),

[0091] X 1 It may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, as a tetravalent aromatic group having 4 to 39 carbon atoms.

[0092] X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and

[0093] Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and

[0094] Y 2 is a device represented by the following general formula (5),

[0095] s, t, and u are positive integers.

[0096] [Chemical Formula 14]

[0097]

[0098] (Equation (3), Z 1 It represents a single bond, or a group denoted by -O-.

[0099] In formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0100] [Chemical Formula 15]

[0101]

[0102] (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0103] The reason why the imide-amide acid copolymer of the present invention is excellent as a raw material for polyimide films, and why the obtained polyimide film possesses excellent characteristics such as low residual stress and coefficient of linear thermal expansion, excellent transparency, and high heat resistance while maintaining low yellowness, is not precise but is thought to be as follows.

[0104] A copolymer composed of a tetracarboxylic acid-derived component consisting of aromatic groups and the specific diamine component above is thought to have a bulky backbone of trifluoromethyl groups, sulfone groups, or cardo structures, and a rigid biphenyl backbone and ester backbone in appropriate proportions, thereby enabling low residual stress, a low coefficient of linear thermal expansion required for TFT substrates, etc., as well as transparency, low yellowness, and high heat resistance.

[0105] On the other hand, even when in an appropriate ratio, the polyamide acid component containing a cardo structure is difficult to undergo thermal imidation during film formation, and when a polymer containing a polyamide acid component containing a cardo structure is formed into a film, it is usually difficult to exhibit good physical properties; however, in the imide-amide acid copolymer of the present invention, since a portion of the component containing a cardo structure is imidized in advance during polymer polymerization, it is believed that the physical properties after film formation are excellent.

[0106] <Imide Part (IM)>

[0107] The imide portion (IM) constituting the imide-amide acid copolymer of the present invention is the portion represented by (IM) of the above formula (1).

[0108] In the above formula (1), X 1 It may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a tetravalent aromatic group having 4 to 39 carbon atoms. Here, a tetravalent aromatic group means that all four carbons bonded to the imide group are aromatic carbons. In addition, the bonding group is X 1 It refers to a coupling that combines each of the two or more orientation rings when the group includes two or more orientation rings. Meanwhile, the coupling is not limited to these.

[0109] X 1 Since this is an aromatic group, the heat resistance of the polyimide is improved, which is desirable.

[0110] X 1 It is preferable to exclude two dicarboxylic acid anhydride portions (four carboxyl group portions) from the tetracarboxylic acid dianhydride that serves as the raw material for the constituent unit X1A derived from the tetracarboxylic acid dianhydride described below.

[0111] Among these, X 1 It is more preferable that the cause be represented by the following formula (6).

[0112] [Chemical Formula 16]

[0113]

[0114] In the above equation (1), Y 1 It is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4).

[0115] [Chemical Formula 17]

[0116]

[0117] (Equation (3), Z 1 It represents a single bond, or a group denoted by -O-.

[0118] In formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0119] Y 1 It is preferable to exclude two amino group portions from the diamine that serves as the raw material for the constituent unit Y1B derived from the diamine described below.

[0120] <Amidic acid portion (AM2)>

[0121] The amide acid portion (AM2) constituting the imide-amide acid copolymer of the present invention is the portion represented by (AM2) of the above formula (1).

[0122] In the above formula (1), X 2 is, X 1 The group may have a tetravalent aromatic group having 4 to 39 different carbon atoms, and may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-. Here, a tetravalent aromatic group means that all four carbons bonded to the imide group are aromatic carbons. In addition, the bonding group is X 1It refers to a coupling that combines each of the two or more orientation rings when the group includes two or more orientation rings. Meanwhile, the coupling is not limited to these.

[0123] X 2 It is preferable to exclude two dicarboxylic acid anhydride portions (four carboxyl group portions) from the tetracarboxylic acid dianhydride that serves as the raw material for the constituent unit X2A derived from the tetracarboxylic acid dianhydride described below.

[0124] Among these, X 2 It is more preferable that the cause be represented by the following formula (7).

[0125] [Chemical Formula 18]

[0126]

[0127] In the above equation (1), Y 2 is a device represented by the following general formula (5).

[0128] [Chemical Formula 19]

[0129]

[0130] (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0131] Y 2 It is preferable to exclude two amino group portions from the diamine that serves as the raw material for the constituent unit Y2B derived from the diamine described below.

[0132] <Amidic acid portion (AM1)>

[0133] The amide acid portion (AM1) constituting the imide-amide acid copolymer of the present invention is the portion represented by (AM1) of the above formula (1).

[0134] The amic acid portion (AM1) is the bonding portion of the imide portion (IM) and the amic acid portion (AM2), and X in the amic acid portion (AM1) 2 is identical to the amic acid portion (AM2), and Y in the amic acid portion (AM1). 1 It is identical to the imid portion (IM).

[0135] <Composition of Imide-Amidic Acid Copolymer>

[0136] In the above equation (1), s is the number of repetition units of the imide portion (IM), and is a positive integer.

[0137] s is preferably 1 to 50 in terms of transparency, low yellowness, and high heat resistance, more preferably 1 to 15, even more preferably 1 to 10, and even more preferably 1 to 5. The average number of repetitions of the imide portion (IM), that is, the average value of s, is preferably 1 to 10, more preferably 1.5 to 9, even more preferably 1.5 to 8, and even more preferably 1.7 to 5. The average number of repetitions of the imide portion (IM) refers to the average value of the number of repetitions of the imide portion (IM) of all imide-amid acid copolymers included in the polyimide varnish or polyimide film described later, and the average value of s refers to the average value of s of all imide-amid acid copolymers included in the polyimide varnish or polyimide film described later.

[0138] In the above formula (1), t is the number of repeating units of the amide acid portion (AM2), and is a positive integer.

[0139] t is preferably 1 to 50 in terms of high heat resistance, low residual stress, and low coefficient of linear thermal expansion, more preferably 1 to 15, even more preferably 1 to 10, and even more preferably 1 to 5. The average number of repetitions of the amide acid portion (AM2), that is, the average value of t, is preferably 1 to 10, more preferably 1.5 to 9, even more preferably 1.5 to 8, and even more preferably 1.7 to 5. The average number of repetitions of the amide acid portion (AM2) refers to the average value of the number of repetitions of the amide acid portion (AM2) of all imide-amide acid copolymers included in the polyimide varnish or polyimide film described later, and the average value of t refers to the average value of t of all imide-amide acid copolymers included in the polyimide varnish or polyimide film described later.

[0140] In the above formula (1), u is a positive integer, which is the number of repeating units consisting of an imide portion (IM), an amide portion (AM1), and an amide portion (AM2).

[0141] u is preferably 5 to 200 in terms of heat resistance, low residual stress, and low coefficient of linear thermal expansion, more preferably 6 to 150, and even more preferably 10 to 120.

[0142] The average number of repetitions of a repeating unit composed of an imide portion (IM), an amide acid portion (AM1), and an amide acid portion (AM2), i.e., the average value of u, is preferably 5 to 200. The average number of repetitions of a repeating unit composed of an imide portion (IM), an amide acid portion (AM1), and an amide acid portion (AM2) refers to the average value of the number of repetitions of a repeating unit composed of an imide portion (IM), an amide acid portion (AM1), and an amide acid portion (AM2) of all imide-amide acid copolymers included in the polyimide varnish or polyimide film described later, and the average value of u refers to the average value of u of all imide-amide acid copolymers included in the polyimide varnish or polyimide film described later.

[0143] The ratio of the total of the imide portion (IM), the amic acid portion (AM1), and the amic acid portion (AM2) to the imide-amic acid copolymer is preferably 80 mass% or more, more preferably 82 mass% or more, and even more preferably 85 mass% or more, with no upper limit and 100 mass% or less.

[0144] In contrast to conventional imide-amid acid copolymers in which the imide portion and the amid acid portion exist randomly, the imide-amid acid copolymer of the present invention is thought to have low residual stress and coefficient of linear thermal expansion, and excellent transparency, low yellowness, and heat resistance because the imide portion (IM), the amid acid portion (AM1), and the amid acid portion (AM2) have a specific structure.

[0145] <Each constituent unit of the imide-amide acid copolymer>

[0146] The imide-amid acid copolymer of the present invention comprises a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the formula (1) above, and the constituent unit constituting this copolymer is described below.

[0147] The imide-amid acid copolymer of the present invention comprises, wherein the imide portion (IM) has a constituent unit X1A derived from a tetracarboxylic acid dianhydride and a constituent unit Y1B derived from a diamine,

[0148] The above-mentioned amide acid portion (AM1) has a constituent unit X2A derived from tetracarboxylic acid dianhydride and a constituent unit Y1B derived from diamine, and

[0149] The above-mentioned amide acid portion (AM2) has a constituent unit X2A derived from tetracarboxylic acid dianhydride and a constituent unit Y2B derived from diamine, and

[0150] Constituent unit X1A comprises a constituent unit derived from an aromatic tetracarboxylic acid dianhydride, and

[0151] Constituent unit X2A comprises a constituent unit derived from an aromatic tetracarboxylic acid dianhydride different from constituent unit X1A, and

[0152] The constituent unit Y1B comprises a constituent unit (B1) derived from a diamine (b1), and the constituent unit (B1) comprises at least one selected from the group consisting of a constituent unit (B11) derived from a compound represented by the following formula (b11), a constituent unit (B12) derived from a compound represented by the following general formula (b12), and a constituent unit (B13) derived from a compound represented by the following general formula (b13).

[0153] It is preferable that the constituent unit Y2B includes a constituent unit (B2) derived from a compound represented by the following general formula (b2).

[0154] [Chemical Formula 20]

[0155]

[0156] (Equation (b12), Z 1 It represents a single bond, or a group denoted by -O-.

[0157] In formula (b13), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0158] In equation (b2), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, k, and n are integers from 0 to 4.

[0159] (Constituent Unit X1A)

[0160] Constituent unit X1A is a constituent unit derived from a tetracarboxylic acid dianhydride that occupies the imide portion (IM) of the copolymer of the present invention, and includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride.

[0161] The constituent unit X1A is not limited to a constituent unit derived from an aromatic tetracarboxylic acid dianhydride, but it is preferable that the constituent unit X1A includes a constituent unit (A1) derived from a compound represented by the following formula (a1).

[0162] [Chemical Formula 21]

[0163]

[0164] The compound represented by formula (a1) is 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF).

[0165] It is desirable to include a constituent unit (A1) derived from a compound represented by formula (a1) so that transparency, low yellowness, and high heat resistance are achieved.

[0166] When constituent unit X1A includes constituent unit (A1), the content ratio of constituent unit (A1) in constituent unit X1A is preferably 50 mol% or more, more preferably 55 mol% or more, even more preferably 60 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more. The upper limit of the content ratio of constituent unit (A1) is not particularly limited and is 100 mol% or less. Constituent unit A may consist only of constituent unit (A1).

[0167] Constituent unit X1A may include constituent units other than constituent unit (A1). Tetracarboxylic acid dianhydrides that provide such constituent units are not particularly limited, but include alicyclic tetracarboxylic acid dianhydrides such as 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, norbonan-2-spiro-α-cyclopentanone-α'-spiro-2''-norbonan-5,5'',6,6''-tetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,4,5-cyclopentanetetracarboxylic acid dianhydride, bicyclo[2.2.2]octa-7-en-2,3,5,6-tetracarboxylic acid dianhydride, and dicyclohexyltetracarboxylic acid dianhydride, and aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride.

[0168] Meanwhile, in the present specification, an alicyclic tetracarboxylic acid dianhydride means a tetracarboxylic acid dianhydride in which, among the four α-carbons of two acid anhydrides (four carboxyl groups), two α-carbons of at least one acid anhydride (two adjacent carboxyl groups) are carbons constituting the alicyclic group, an aromatic tetracarboxylic acid dianhydride means a tetracarboxylic acid dianhydride in which four α-carbons of two acid anhydrides (four carboxyl groups) are carbons constituting the aromatic group, and an aliphatic tetracarboxylic acid dianhydride means a tetracarboxylic acid dianhydride that does not correspond to an alicyclic tetracarboxylic acid dianhydride or an aromatic tetracarboxylic acid dianhydride.

[0169] The constituent units optionally included in constituent unit X1A may be of one type or two or more types.

[0170] (Constituent Units x 2A)

[0171] Constituent unit X2A is a constituent unit derived from a tetracarboxylic acid dianhydride that occupies the amic acid portion (AM2) and amic acid portion (AM1) of the copolymer of the present invention, and includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride that is different from constituent unit X1A.

[0172] There are no limitations on whether the constituent unit X2A includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride different from the constituent unit X1A, but it is preferable that the constituent unit X2A includes a constituent unit (A2) derived from an aromatic tetracarboxylic acid dianhydride (a2).

[0173] Here, the constituent unit (A2) includes at least one selected from the group consisting of a constituent unit (A21) derived from a compound represented by the following formula (a21), a constituent unit (A22) derived from a compound represented by the following formula (a22), a constituent unit (A23) derived from a compound represented by the following formula (a23), a constituent unit (A24) derived from a compound represented by the following formula (a24), and a constituent unit (A25) derived from a compound represented by the following formula (a25).

[0174] [Chemical Formula 22]

[0175]

[0176] The compound represented by formula (a21) is a biphenyltetracarboxylic acid dianhydride (BPDA), and specific examples thereof include the 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (s-BPDA) represented by the following formula (a21s), the 2,3,3',4'-biphenyltetracarboxylic acid dianhydride (a-BPDA) represented by the following formula (a21a), and the 2,2',3,3'-biphenyltetracarboxylic acid dianhydride (i-BPDA) represented by the following formula (a21i). Among these, the 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (s-BPDA) represented by the following formula (a21s) is preferred.

[0177] [Chemical Formula 23]

[0178]

[0179] The compound represented by formula (a22) is p-phenylenebis(trimellitate) anhydride (TAHQ).

[0180] The compound represented by formula (a23) is oxydiphthalic anhydride (ODPA), and specific examples thereof include 4,4'-oxydiphthalic anhydride (s-ODPA) represented by the following formula (a23s), 3,4'-oxydiphthalic anhydride (a-ODPA) represented by the following formula (a23a), and 3,3'-oxydiphthalic anhydride (i-ODPA) represented by the following formula (a23i). Among these, 4,4'-oxydiphthalic anhydride (s-ODPA) represented by the following formula (a23s) is preferred.

[0181] [Chemical Formula 24]

[0182]

[0183] The compound represented by formula (a24) is pyromellitic acid dianhydride (PMDA).

[0184] The compound represented by formula (a25) is 2,3,6,7-naphthalenetetracarboxylic acid dianhydride.

[0185] The constituent unit (A2) preferably includes at least one selected from the group consisting of constituent unit (A21) and constituent unit (A22) in terms of high heat resistance and low residual stress, and more preferably includes constituent unit (A21).

[0186] In particular, the constituent unit (A21) is desirable in terms of improving the heat resistance and thermal stability of the film and further reducing residual stress, and the constituent unit (A22) is desirable in terms of reducing residual stress and reducing the coefficient of linear thermal expansion.

[0187] Constituent unit X2A may include constituent units other than constituent unit (A2). Tetracarboxylic acid dianhydrides that provide such constituent units are not particularly limited, but include alicyclic tetracarboxylic acid dianhydrides such as 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, norbonan-2-spiro-α-cyclopentanone-α'-spiro-2''-norbonan-5,5'',6,6''-tetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,4,5-cyclopentanetetracarboxylic acid dianhydride, bicyclo[2.2.2]octa-7-en-2,3,5,6-tetracarboxylic acid dianhydride, and dicyclohexyltetracarboxylic acid dianhydride, and aliphatic tetracarboxylic acid dianhydrides such as 1,2,3,4-butanetetracarboxylic acid dianhydride.

[0188] The constituent units optionally included in constituent unit X2A may be of one type or two or more types.

[0189] The ratio of the total of constituent units (A21) to (A25) in the constituent unit (A2) is preferably 45 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 99 mol% or more. The upper limit of the ratio is not specifically limited and is 100 mol% or less. The constituent unit (A2) may include at least one type selected from constituent units (A21) to (A25), and may consist of only one type selected from constituent units (A21) to (A25).

[0190] When a constituent unit (A2) contains two or more constituent units selected from constituent units (A21) to (A25), there is no particular restriction on the ratio of each constituent unit within the constituent unit (A2), and it can be any ratio.

[0191] The proportion of the constituent unit (A2) in the constituent unit X2A is preferably 45 mol% or more, more preferably 60 mol% or more, and even more preferably 85 mol% or more. The upper limit of the said content ratio is not particularly limited and is 100 mol% or less.

[0192] When constituent unit X1A includes constituent unit (A1) and constituent unit X2A includes constituent unit (A2), the molar ratio [(A1) / (A2)] of constituent unit (A1) and constituent unit (A2) among constituent units derived from the tetracarboxylic acid dianhydride of the imide-amide acid copolymer is preferably 10 / 90 to 55 / 45, more preferably 15 / 85 to 50 / 50, and even more preferably 20 / 80 to 45 / 55.

[0193] (Constituent Unit Y1B)

[0194] The constituent unit Y1B is a constituent unit derived from a diamine that occupies the imide portion (IM) and the amic acid portion (AM1) of the copolymer of the present invention, and includes a constituent unit (B1) derived from a diamine (b1), wherein the constituent unit (B1) comprises at least one selected from the group consisting of a constituent unit (B11) derived from a compound represented by the following formula (b11), a constituent unit (B12) derived from a compound represented by the following general formula (b12), and a constituent unit (B13) derived from a compound represented by the following general formula (b13).

[0195] From the perspective of heat resistance, it is preferable to include a constituent unit (B13) derived from a compound represented by formula (b13) having a cardo structure, and from the perspective of transparency, it is preferable to include a constituent unit (B11) derived from a compound represented by formula (b11) having an electron-absorbing group, and a constituent unit (B12) derived from a compound represented by formula (b12).

[0196] The ratio of the total of constituent units (B11) to (B13) in constituent unit (B1) is preferably 45 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 99 mol% or more. The upper limit of the ratio is not specifically limited and is 100 mol% or less.

[0197] [Chemical Formula 25]

[0198]

[0199] (Equation (b12), Z 1 It represents a single bond, or a group denoted by -O-.

[0200] In formula (b13), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0201] It is preferable that the constituent unit (B11) be at least one selected from the group consisting of a constituent unit (B111) derived from a compound represented by the following formula (b111) and a constituent unit (B112) derived from a compound represented by the following formula (b112).

[0202] The constituent unit (B11) may be only the constituent unit (B111), only the constituent unit (B112), or a combination of the constituent unit (B111) and the constituent unit (B112).

[0203] [Chemical Formula 26]

[0204]

[0205] The compound represented by formula (b111) is 4,4'-diaminodiphenylsulfone (4,4'-DDS), and the compound represented by formula (b112) is 3,3'-diaminodiphenylsulfone (3,3'-DDS).

[0206] The constituent unit (B12) preferably comprises at least one constituent unit selected from the group consisting of a constituent unit (B121) derived from a compound represented by the following formula (b121) and a constituent unit (B122) derived from a compound represented by the following formula (b122), and more preferably comprises a constituent unit (B122) derived from a compound represented by the following formula (b122).

[0207] [Chemical Formula 27]

[0208]

[0209] The compound represented by formula (b121) is 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA).

[0210] The compound represented by formula (b122) is 2,2'-bis(trifluoromethyl)benzidine (TFMB).

[0211] The constituent unit (B13) is a constituent unit derived from the compound represented by the above formula (b13).

[0212] In the above formula (b13), R is independently a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, preferably independently a hydrogen atom, a fluorine atom, or a methyl group, more preferably a hydrogen atom.

[0213] Examples of compounds represented by the above formula (b13) include 9,9-bis(4-aminophenyl)fluorene (BAFL), 9,9-bis(3-fluoro-4-aminophenyl)fluorene, and 9,9-bis(3-methyl-4-aminophenyl)fluorene, and at least one selected from the group consisting of these three compounds is preferred, and 9,9-bis(4-aminophenyl)fluorene is more preferred from the perspective of heat resistance.

[0214] The constituent unit Y1B may include constituent units other than the constituent unit (B1). Diamines providing such constituent units are not particularly limited, but include 1,4-phenylenediamine, p-xylylenediamine, 3,5-diaminobenzoic acid, 1,5-diaminonaphthalene, 2,2'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminobenzanilide, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, N,N'-bis(4-aminophenyl)terephthalamide, Examples include aromatic diamines such as 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and 1,4-bis(4-aminophenoxy)benzene; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane; and aliphatic diamines such as ethylenediamine and hexamethylenediamine.

[0215] Meanwhile, in this specification, an aromatic diamine means a diamine containing one or more aromatic rings, a diamine alicyclic means a diamine containing one or more alicyclic rings and not an aromatic ring, and an aliphatic diamine means a diamine that does not contain either an aromatic ring or alicyclic rings.

[0216] The constituent units optionally included in constituent unit Y1B may be of one type or two or more types.

[0217] (Constituent Unit Y2B)

[0218] The constituent unit Y2B is a constituent unit derived from a diamine that occupies the amic acid portion (AM2) of the copolymer of the present invention, and the constituent unit Y2B includes a constituent unit (B2) derived from a compound represented by the following general formula (b2) in terms of low residual stress, low coefficient of linear thermal expansion, and heat resistance.

[0219] [Chemical Formula 28]

[0220]

[0221] (Equation (b2), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0222] The constituent unit (B2) preferably includes a constituent unit (B21) derived from a compound represented by the following formula (b21) in terms of heat resistance, low residual stress, and low coefficient of linear thermal expansion.

[0223] [Chemical Formula 29]

[0224]

[0225] The compound represented by formula (b21) is 4-aminophenyl-4-aminobenzoate (4-BAAB).

[0226] The constituent unit Y2B may include constituent units other than the constituent unit (B2). Diamines providing such constituent units are not particularly limited, but include 1,4-phenylenediamine, p-xylylenediamine, 3,5-diaminobenzoic acid, 1,5-diaminonaphthalene, 2,2'-dimethylbiphenyl-4,4'-diamine, 2,2'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminobenzanilide, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, N,N'-bis(4-aminophenyl)terephthalamide, Examples include aromatic diamines such as 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and 1,4-bis(4-aminophenoxy)benzene; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane; and aliphatic diamines such as ethylenediamine and hexamethylenediamine.

[0227] The constituent units optionally included in constituent unit Y2B may be of one type or two or more types.

[0228] When the sum of constituent unit Y1B and constituent unit Y2B is 100 mol%, the proportion of constituent unit (B1) among the constituent units derived from the diamine of the copolymer is preferably 10 to 55 mol%, more preferably 20 to 50 mol%, and even more preferably 25 to 45 mol%.

[0229] When the sum of constituent unit Y1B and constituent unit Y2B is 100 mol%, the proportion of constituent unit (B2) among the constituent units derived from the diamine of the copolymer is preferably 45 to 90 mol%, more preferably 50 to 80 mol%, and even more preferably 55 to 75 mol%.

[0230] When constituent unit Y1B includes constituent unit (B1) and constituent unit Y2B includes constituent unit (B2), the molar ratio [(B1) / (B2)] of constituent unit (B1) and constituent unit (B2) among the constituent units derived from the diamine of the imide-amide acid copolymer is preferably 10 / 90 to 55 / 45, more preferably 20 / 80 to 50 / 50, and even more preferably 25 / 75 to 45 / 55.

[0231] When the sum of constituent unit Y1B and constituent unit Y2B is 100 mol%, the ratio of the sum of constituent unit (B1) and constituent unit (B2) among the constituent units derived from the diamine of the copolymer is preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more, and the upper limit is not particularly limited and is 100 mol% or less.

[0232] The ratio of the sum of constituent units X1A, X2A, Y1B, and Y2B to the sum of constituent units constituting the imide-amide acid copolymer is preferably 80 mass% or more, more preferably 82 mass% or more, and even more preferably 85 mass% or more, with no upper limit, and is 100 mass% or less.

[0233] (Other constituent units)

[0234] The imide-amide acid copolymer of the present invention may include constituent units other than the above-mentioned constituent unit X1A, constituent unit X2A, constituent unit Y1B, and constituent unit Y2B.

[0235] The imide-amide acid copolymer of the present invention may additionally include a constituent unit (B3) derived from a compound represented by the following general formula (b3). By including the constituent unit (B3), residual stress is reduced.

[0236] [Chemical Formula 30]

[0237]

[0238] In equation (b3), Z 4 and Z 5Each independently represents a divalent aliphatic group or a divalent aromatic group, and R 4 and R 5 Each independently represents a monovalent aromatic group or a monovalent aliphatic group, and R 6 and R 7 Each independently represents a monovalent aliphatic group, and R 8 and R 9 , each independently represents a monovalent aliphatic group or a monovalent aromatic group, m and n each independently represent an integer greater than or equal to 1, and the sum of m and n represents an integer between 2 and 1000. provided that R 4 and R 5 At least one of them represents a monovalent aromatic group.

[0239] Meanwhile, in equation (b3), two or more different repeating units listed in parallel by [ ] may each be repeated in any form and order of random, alternating, or block.

[0240] In equation (b3), Z 4 and Z 5 The divalent aliphatic group or divalent aromatic group in this case may be substituted with a fluorine atom or may contain an oxygen atom. In the case where an oxygen atom is included as an ether bond, the carbon number indicated below refers to all carbons included in the aliphatic group or aromatic group.

[0241] Examples of divalent aliphatic groups include divalent saturated or unsaturated aliphatic groups having 1 to 20 carbon atoms. The number of carbon atoms of the divalent aliphatic group is preferably 3 to 20.

[0242] Examples of divalent saturated aliphatic groups include alkylene groups and alkylene oxy groups having 1 to 20 carbon atoms. Examples of alkylene groups include methylene groups, ethylene groups, propylene groups, trimethylene groups, tetramethylene groups, hexamethylene groups, octamethylene groups, decamethylene groups, dodecamethylene groups, etc. Examples of alkylene oxy groups include propylene oxy groups, trimethylene oxy groups, etc.

[0243] Examples of divalent unsaturated aliphatic groups include alkenylene groups having 2 to 20 carbon atoms, such as vinylene groups, propenylene groups, and alkylene groups having an unsaturated double bond at the terminal end.

[0244] Examples of divalent aromatic groups include arylene groups with 6 to 20 carbon atoms and aralylene groups with 7 to 20 carbon atoms. Z 4 and Z 5 Specific examples of arylene groups having 6 to 20 carbon atoms include o-phenylene groups, m-phenylene groups, p-phenylene groups, 4,4'-biphenylylene groups, 2,6-naphthylene groups, etc.

[0245] Z 4 and Z 5 In particular, trimethylene groups and p-phenylene groups are preferred, and trimethylene groups are more preferred.

[0246] In equation (b3), R 4 ~R 9 Examples of monovalent aliphatic groups include monovalent saturated or unsaturated aliphatic groups. Examples of monovalent saturated aliphatic groups include alkyl groups having 1 to 22 carbon atoms, such as methyl groups, ethyl groups, and propyl groups. Examples of monovalent unsaturated aliphatic groups include alkenyl groups having 2 to 22 carbon atoms, such as vinyl groups and propenyl groups. These groups may be substituted with fluorine atoms.

[0247] R of equation (b3) 4 , R 5 , R 8 and R 9Examples of monovalent aromatic groups include an aryl group having 6 to 20 carbon atoms, an aryl group having 7 to 30 carbon atoms substituted with an alkyl group, and an aralkyl group having 7 to 30 carbon atoms. Among the monovalent aromatic groups, an aryl group is preferred, and a phenyl group is more preferred.

[0248] R 4 and R 5 At least one side of represents a monovalent aromatic group, Z 4 and Z 5 It is desirable that all are monovalent aromatic groups, and R 4 and R 5 It is more desirable that all of them are phenyl groups.

[0249] R 6 and R 7 In the case of the group, an alkyl group having 1 to 6 carbon atoms is preferred, and a methyl group is more preferred.

[0250] R 8 and R 9 In the case of the group, a monovalent aliphatic group is preferred, and a methyl group is more preferred.

[0251] As described above, among the compounds represented by the general formula (b3) above, the compound represented by the following formula (b31) is preferred.

[0252] [Chemical Formula 31]

[0253]

[0254] (In Equation (b31), m and n are equivalent to m and n of Equation (b3), respectively, and the preferred range is also the same.)

[0255] In formulas (b3) and (b31), m represents the number of repetitions of a siloxane unit to which at least one aromatic group of univalent valence is attached, and in formulas (b3) and (b31), n ​​represents the number of repetitions of a siloxane unit to which one aliphatic group is attached.

[0256] In equations (b3) and (b31), m and n each independently represent an integer of 1 or more, and the sum of m and n (m+n) represents an integer of 2 to 1000. The sum of m and n is preferably an integer of 3 to 500, more preferably 3 to 100, and even more preferably 3 to 50.

[0257] The ratio of m / n in formulas (b3) and (b31) is preferably 5 / 95 to 50 / 50, more preferably 10 / 90 to 40 / 60, and even more preferably 20 / 80 to 30 / 70.

[0258] The functional group equivalent (amine equivalent) of the compound represented by formula (b3) is preferably 150 to 5,000 g / mol, more preferably 400 to 4,000 g / mol, and even more preferably 500 to 3,000 g / mol.

[0259] Meanwhile, the functional group equivalent refers to the mass of the compound represented by formula (b3) per mole of functional group (amino group).

[0260] Among the compounds represented by the above general formula (b3), those available as commercial products include “X-22-9409”, “X-22-1660B”, “X-22-161A”, and “X-22-161B” manufactured by Shin-Etsu Chemical Co., Ltd.

[0261] When a constituent unit (B3) is included, the ratio of the constituent unit (B3) to the total amount of the constituent unit (B3), constituent unit Y1B and constituent unit Y2B is preferably 0.01 to 15.0 mol%, more preferably 0.5 to 12.0 mol%, and even more preferably 1.0 to 8.0 mol%.

[0262] When a constituent unit (B3) is included, the content of polyorganosiloxane units relative to the total of constituent units constituting the imid-amide acid copolymer is preferably 1 to 20 mass%, more preferably 2 to 18 mass%, and even more preferably 5 to 15 mass%. If the content of the polyorganosiloxane units is within the above range, low retardation and low residual stress can be achieved more highly.

[0263] Examples of commercially available compounds represented by formula (b3) include “X-22-9409” and “X-22-1660B-3” manufactured by Shin-Etsu Chemical Co., Ltd.

[0264] [Method for manufacturing an imide-amide acid copolymer]

[0265] The imide-amide acid copolymer of the present invention may be prepared by any method, but it is preferred to be obtained by the following method.

[0266] The method for manufacturing an imide-amide acid copolymer of the present invention comprises the following process 1 and process 2.

[0267] Process 1: A process of obtaining an imide oligomer by reacting the tetracarboxylic acid component constituting the imide portion (IM) with the diamine component.

[0268] Process 2: A process of reacting the imide oligomer obtained in Process 1 with a tetracarboxylic acid component and a diamine component constituting the amic acid portion (AM2) to obtain an imide-amic acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amic acid portion (AM1), and an amic acid portion (AM2), represented by the following formula (1).

[0269] [Chemical Formula 32]

[0270]

[0271] (In the formula (1),

[0272] X 1It may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, as a tetravalent aromatic group having 4 to 39 carbon atoms.

[0273] X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and

[0274] Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and

[0275] Y 2 is a device represented by the following general formula (5),

[0276] s, t, and u are positive integers.

[0277] [Chemical Formula 33]

[0278]

[0279] (Equation (3), Z 1 It represents a single bond, or a group denoted by -O-.

[0280] In formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0281] [Chemical Formula 34]

[0282]

[0283] (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0284] According to the method for manufacturing an imide-amid acid copolymer of the present invention, it is possible to control the imide portion and the amid acid portion to a specific structure. Therefore, unlike conventional imide-amid acid copolymers in which the imide portion and the amid acid portion exist randomly, it is believed that an imide-amid acid copolymer can be obtained in which the heat resistance, low residual stress, and low linear thermal expansion coefficient are expected to be improved, as the imide portion and the polyamid acid portion have a thermal imidization reactivity according to each component.

[0285] Among these, the method for manufacturing a suitable copolymer of the present invention comprises the following process 1 and process 2.

[0286] Process 1: A process of obtaining an imide oligomer by reacting a compound providing a constituent unit X1A derived from a tetracarboxylic acid dianhydride with a compound providing a constituent unit Y1B derived from a diamine.

[0287] Process 2: A process of reacting the imide oligomer obtained in Process 1 with a compound providing a constituent unit X2A derived from a tetracarboxylic acid dianhydride and a compound providing a constituent unit Y2B derived from a diamine to obtain an imide-amid acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2) represented by the formula (1).

[0288] However, the compound providing constituent unit X1A comprises an aromatic tetracarboxylic acid dianhydride,

[0289] A compound providing constituent unit X2A comprises an aromatic tetracarboxylic acid dianhydride different from constituent unit X1A, and

[0290] A compound that imparts a constituent unit Y1B comprises a compound that imparts a constituent unit (B1), and the compound that imparts the constituent unit (B1) comprises at least one selected from the group consisting of a compound represented by the following formula (b11), a compound represented by the following general formula (b12), and a compound represented by the following general formula (b13).

[0291] The compound imparting the constituent unit Y2B includes a compound represented by the following general formula (b2).

[0292] [Chemical Formula 35]

[0293]

[0294] (Equation (b12), Z 1 It represents a single bond, or a group denoted by -O-.

[0295] In formula (b13), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms.

[0296] In equation (b2), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4.

[0297] By the manufacturing method having the above-mentioned processes 1 and 2, a copolymer capable of forming a film having excellent transparency and heat resistance, low yellowness, and excellent low residual stress can be manufactured.

[0298] Hereinafter, a method for manufacturing the copolymer of the present invention will be described.

[0299] Process 1

[0300] Process 1 is a process of obtaining an imide oligomer by reacting a tetracarboxylic acid component constituting the imide portion (IM) with a diamine component.

[0301] The tetracarboxylic acid component constituting the imide portion (IM) is preferably an aromatic tetracarboxylic acid dianhydride.

[0302] Process 1 is a process of obtaining an imide oligomer by reacting a compound providing a constituent unit X1A derived from a tetracarboxylic acid dianhydride with a compound providing a constituent unit Y1B derived from a diamine, more preferably.

[0303] Compounds that provide constituent unit X1A include aromatic tetracarboxylic acid dianhydrides.

[0304] A compound that imparts a constituent unit Y1B comprises a compound that imparts a constituent unit (B1), wherein the compound that imparts the constituent unit (B1) comprises at least one selected from the group consisting of a compound represented by the formula (b11), a compound represented by the general formula (b12), and a compound represented by the general formula (b13).

[0305] The tetracarboxylic acid component used in Process 1 preferably includes a compound that provides a constituent unit (A1), and the entire amount thereof is preferably used in Process 1, and may include a tetracarboxylic acid component other than the compound that provides the constituent unit (A1) within a range that does not impair the effects of the present invention.

[0306] The diamine component used in Process 1 preferably includes a compound that provides a constituent unit (B1), and may also include a diamine component other than the compound that provides the constituent unit (B1) to a extent that does not impair the effect of the present invention.

[0307] In process 1, the diamine component with respect to the tetracarboxylic acid component is preferably 1.01 to 2 moles, more preferably 1.05 to 1.9 moles, and even more preferably 1.1 to 1.7 moles.

[0308] There are no particular restrictions on the method of reacting the tetracarboxylic acid component and the diamine component to obtain the imide oligomer in Process 1, and known methods can be used.

[0309] Specific reaction methods include: (1) a method of introducing a tetracarboxylic acid component, a diamine component, and a reaction solvent into a reactor, stirring at 10 to 110°C for 0.5 to 30 hours, and then raising the temperature to carry out an imidation reaction; (2) a method of introducing a diamine component and a reaction solvent into a reactor and dissolving them, then introducing a tetracarboxylic acid component, stirring at 10 to 110°C for 0.5 to 30 hours as needed, and then raising the temperature to carry out an imidation reaction; and (3) a method of introducing a tetracarboxylic acid component, a diamine component, and a reaction solvent into a reactor and immediately raising the temperature to carry out an imidation reaction.

[0310] In the imidation reaction, it is preferable to carry out the reaction while removing water generated during manufacturing using a Dean Stark apparatus or the like. By performing such operations, the degree of polymerization and the imidation rate can be further increased.

[0311] In the above imidation reaction, a known imidation catalyst may be used. Examples of imidation catalysts include base catalysts or acid catalysts.

[0312] Examples of base catalysts include organic base catalysts such as pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-rutidine, 2,6-rutidine, trimethylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, and inorganic base catalysts such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate.

[0313] In addition, examples of acid catalysts include crotonic acid, acrylic acid, trans-3-hexanoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxycyanoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, naphthalenesulfonic acid, etc. The above imidization catalysts may be used alone or in combination of two or more types.

[0314] Among the above, from the perspective of handling, a base catalyst is preferred, an organic base catalyst is more preferred, one or more selected from triethylamine and triethylenediamine are more preferred, and triethylamine is more preferred.

[0315] The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C, in terms of the reaction rate and inhibition of gelation. In addition, the reaction time is preferably 0.5 to 10 hours after the start of the discharge of the generated water.

[0316] The imide oligomer obtained in process 1 preferably has an imide repeating structural unit formed from a compound providing a constituent unit (A1) and a compound providing a constituent unit (B1).

[0317] In addition, the oligomer obtained in Process 1 preferably has amino groups at both ends of the main chain of the molecular chain.

[0318] By the above method, a solution containing an imide oligomer dissolved in a solvent is obtained. In the solution containing the imide oligomer obtained in Process 1, at least a portion of the component used as the tetracarboxylic acid component or the diamine component in Process 1 may be contained as an unreacted monomer, to the extent that the effects of the present invention are not impaired.

[0319] <Process 2>

[0320] Process 2 in the manufacturing method of the present invention is a process of reacting the imide oligomer obtained in Process 1 with a tetracarboxylic acid component and a diamine component constituting the amide acid portion (AM2) to obtain an imide-amide acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amide acid portion (AM1), and an amide acid portion (AM2) represented by the formula (1).

[0321] The tetracarboxylic acid component constituting the amide acid portion (AM2) used in Process 2 is preferably an aromatic tetracarboxylic acid dianhydride.

[0322] Process 2 is a process of obtaining an imide-amide acid copolymer by reacting a compound providing a constituent unit X2A derived from a tetracarboxylic acid dianhydride with a compound providing a constituent unit Y2B derived from a diamine, more preferably.

[0323] Compounds that provide constituent unit X2A include aromatic tetracarboxylic acid dianhydrides.

[0324] The compound that imparts the constituent unit Y2B includes a compound that imparts the constituent unit (B2), and the compound that imparts the constituent unit (B2) includes a compound represented by the general formula (b2) and preferably includes a compound represented by the formula (b21).

[0325] The tetracarboxylic acid component used in Process 2 preferably includes a compound that provides a constituent unit (A2), and may also include a tetracarboxylic acid component other than the compound that provides the constituent unit (A2) to a extent that does not impair the effects of the present invention. Examples of tetracarboxylic acid components other than the compound that provides the constituent unit (A2) include a compound that provides the constituent unit (A1), provided, however, that the tetracarboxylic acid component used in Process 2 does not include the compound that provides the constituent unit (A1). Furthermore, it is preferable to use the entire amount of the compound that provides the constituent unit (A2) in Process 2.

[0326] The diamine component used in process 2 preferably includes a compound that provides a constituent unit (B2), and may also include a diamine component other than the compound that provides the constituent unit (B2) to a extent that does not impair the effect of the present invention.

[0327] After the completion of process 2, when introducing polyorganosiloxane units into the imid-amide acid copolymer, a diamine containing polyorganosiloxane units or a tetracarboxylic acid dianhydride may be reacted, and it is preferable to react a diamine containing polyorganosiloxane units, and it is more preferable to react a compound that imparts the constituent unit (B3).

[0328] There are no particular restrictions on the method of reacting the tetracarboxylic acid component with the imide oligomer obtained in Process 1 to obtain the imide-amide acid copolymer in Process 2, and known methods may be used.

[0329] Specific reaction methods include: (1) a method of introducing the imide oligomer obtained in Process 1, the tetracarboxylic acid component, the diamine component, and the solvent into a reactor and stirring for 1 to 72 hours in a range of 0 to 120°C, preferably 5 to 80°C; (2) a method of introducing the imide oligomer obtained in Process 1 and the solvent into a reactor to dissolve them, then introducing the tetracarboxylic acid component and the diamine component and stirring for 1 to 72 hours in a range of 0 to 120°C, preferably 5 to 80°C.

[0330] When the reaction is carried out at 80°C or lower, the molecular weight of the copolymer obtained in process 2 does not fluctuate depending on the temperature history during polymerization, and the progression of thermoimidation can also be suppressed, so the copolymer can be stably produced.

[0331] By the above method, a copolymer solution containing an imide-amide acid copolymer dissolved in a solvent is obtained.

[0332] The concentration of the copolymer in the obtained copolymer solution is typically in the range of 1 to 50 mass%, preferably 3 to 35 mass%, and more preferably 5 to 30 mass%.

[0333] The number average molecular weight of the imide-amide acid copolymer obtained by the manufacturing method of the present invention is preferably 5,000 to 500,000 in terms of the mechanical strength of the polyimide film obtained. In addition, the weight average molecular weight (Mw) is preferably 10,000 to 800,000 in terms of the same, and more preferably 100,000 to 300,000. Meanwhile, the number average molecular weight of the copolymer can be obtained, for example, from the standard polymethyl methacrylate (PMMA) equivalent value obtained by gel filtration chromatography measurement.

[0334] Next, the raw materials, etc. used in this manufacturing method will be explained.

[0335] Tetracarboxylic acid component

[0336] For the tetracarboxylic acid component used as a raw material for the imide-amid acid copolymer in the present manufacturing method, it is preferable to use a compound that provides each constituent unit as described in (constituent unit XIA) and (constituent unit X2A) of the <each constituent unit of the imide-amid acid copolymer> above. For example, a compound represented by formula (a1) may be used as a compound that provides constituent unit (A1), but is not limited thereto and may be a derivative thereof within the scope of providing the same constituent unit. Examples of such derivatives include a tetracarboxylic acid corresponding to the compound represented by formula (a1) and an alkyl ester of the said tetracarboxylic acid. A compound represented by formula (a1) is preferred as a compound that provides constituent unit (A1).

[0337] Likewise, compounds that impart the constituent unit (A2) may include compounds represented by formula (a21), compounds represented by formula (a22), compounds represented by formula (a23), compounds represented by formula (a24), and compounds represented by formula (a25), but are not limited thereto and may also be derivatives thereof within the scope of imparting the same constituent unit. Examples of such derivatives include tetracarboxylic acids corresponding to compounds represented by any of formulas (a21) to (a25) and alkyl esters of said tetracarboxylic acids. As for the compound imparting the constituent unit (A2), compounds represented by any of formulas (a21) to (a25) are preferred.

[0338] The molar ratio [(A1) / (A2)] of the compound providing the constituent unit (A1) and the compound providing the constituent unit (A2) among the tetracarboxylic acid components used as raw materials for the imide-amide acid copolymer in the present manufacturing method is preferably 10 / 90 to 55 / 45, more preferably 15 / 85 to 50 / 50, and even more preferably 20 / 80 to 45 / 55.

[0339] The ratio of the total of compounds providing constituent units (A21) to (A25) among the compounds providing constituent unit (A2) is preferably 45 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 99 mol% or more. The upper limit of the ratio is not particularly limited and is 100 mol% or less.

[0340] The tetracarboxylic acid component used as a raw material for the imide-amide acid copolymer may include compounds other than the compound providing the constituent unit (A1), the compound providing the constituent unit (A21), the compound providing the constituent unit (A22), the compound providing the constituent unit (A23), the compound providing the constituent unit (A24), and the compound providing the constituent unit (A25), and such compounds may be one type or two or more types.

[0341] <Diamine component>

[0342] The molar ratio [(B1) / (B2)] of the compound providing the constituent unit (B1) and the compound providing the constituent unit (B2) among the diamine components used as raw materials for the imide-amide acid copolymer in the present manufacturing method is preferably 10 / 90 to 55 / 45, more preferably 20 / 80 to 50 / 50, and even more preferably 25 / 75 to 45 / 55.

[0343] As for the compound providing the constituent unit (B1), it is preferable to select one or more from the group consisting of a compound providing the constituent unit (B11), a compound providing the constituent unit (B12), and a compound providing the constituent unit (B13). The ratio of the total of compounds providing constituent units (B11) to (B13) among the compounds providing the constituent unit (B1) is preferably 45 mol% or more, more preferably 70 mol% or more, even more preferably 90 mol% or more, and particularly preferably 99 mol% or more. The upper limit of the ratio is not particularly limited and is 100 mol% or less.

[0344] As for the compound that provides the constituent unit (B2), at least one type of compound that provides the constituent unit (B2) is preferred.

[0345] The diamine component used as a raw material for the imide-amide acid copolymer may include compounds other than the compound providing the constituent unit (B11), the compound providing the constituent unit (B12), the compound providing the constituent unit (B13), and the compound providing (B2), and such compounds may be one type or two or more types.

[0346] Examples of compounds that provide the constituent unit (B1) and the compounds that provide the constituent unit (B2) include diamines, but are not limited thereto; they may also be derivatives thereof within the scope of providing the same constituent unit. Examples of such derivatives include diisocyanates corresponding to diamines. As for the compounds that provide the constituent unit (B1) and the compounds that provide the constituent unit (B2), diamines are preferred.

[0347] When a copolymer contains a compound that provides a constituent unit (B3), the compound that provides the constituent unit (B3) is preferably included in an amount of 0.01 to 15.0 mol%, more preferably 0.5 to 12.0 mol%, and even more preferably 1.0 to 8.0 mol% with respect to the total amount of the compound that provides the constituent unit (B3) and the diamine component.

[0348] In the present invention, the ratio of the input amount of the tetracarboxylic acid component and the diamine component used in the overall process of manufacturing a copolymer, including process 1, process 2, and a reaction process with other components such as a compound that provides a constituent unit (B3) after the end of process 2, is preferably 0.9 to 1.1 moles of the diamine component per 1 mole of the tetracarboxylic acid component.

[0349] <Terminal Sachet>

[0350] In addition, in the present invention, in addition to the aforementioned tetracarboxylic acid component and diamine component, a terminal encapsulant may be used in the preparation of the imide-amide acid copolymer. It is preferable to use the terminal encapsulant during the reaction process with other components, such as a compound that provides the constituent unit (B3) in process 2 or after the end of process 2.

[0351] Monoamines or dicarboxylic acids are preferred as terminal sealants. The amount of terminal sealant introduced is preferably 0.0001 to 0.1 mole per 1 mole of tetracarboxylic acid component, and particularly preferably 0.001 to 0.06 mole. Examples of monoamine terminal sealants include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. Among these, benzylamine and aniline can be suitably used. As for dicarboxylic acid terminal sealants, dicarboxylic acids are preferred, and a portion thereof may be ring-closing. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. are suggested. Among these, phthalic acid and phthalic anhydride can be used appropriately.

[0352] Solvent

[0353] The solvent used in the method for manufacturing the copolymer of the present invention may be any solvent capable of dissolving the resulting imide-amid acid copolymer. Examples include aprotic solvents, phenolic solvents, etheric solvents, carbonate solvents, etc.

[0354] Specific examples of aprotic solvents include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea, lactone solvents such as γ-butyrolactone, γ-valerolactone, phosphorus-containing amide solvents such as hexamethylphosphoricamide, hexamethylphosphintriamide, sulfur-containing solvents such as dimethylsulfone, dimethyl sulfoxide, sulfolane, ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, methylcyclohexanone, and ester solvents such as acetic acid (2-methoxy-1-methylethyl).

[0355] Specific examples of phenolic solvents include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, etc.

[0356] Specific examples of ether-based solvents include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, etc.

[0357] Specific examples of carbonate-based solvents include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, etc.

[0358] Among the above reaction solvents, amide-based solvents or lactone-based solvents are preferred, amide-based solvents are more preferred, and N-methyl-2-pyrrolidone is even more preferred. The above reaction solvents may be used alone or in a mixture of two or more types.

[0359] [Varnish]

[0360] The varnish of the present invention is formed by dissolving the imide-amid acid copolymer of the present invention, which is a precursor of a polyimide resin, in an organic solvent. That is, the varnish of the present invention comprises the copolymer of the present invention and an organic solvent, wherein the copolymer is dissolved in the organic solvent.

[0361] The organic solvent may be any solvent that dissolves the copolymer of the present invention and is not particularly limited, but it is preferable to use the compounds described above, either alone or in a mixture of two or more, as a solvent used to manufacture the copolymer of the present invention.

[0362] The varnish of the present invention may be the copolymer solution described above itself, or may be a copolymer solution to which a diluent has been further added.

[0363] The varnish of the present invention may additionally contain an imidation catalyst and a dehydration catalyst in order to efficiently promote the imidation of the amide acid portion in the copolymer of the present invention. As for the imidation catalyst, it is sufficient to be an imidation catalyst having a boiling point of 40°C or higher and 180°C or lower, and an amine compound having a boiling point of 180°C or lower may be cited as a preferred example. If the imidation catalyst has a boiling point of 180°C or lower, there is no risk of the film becoming discolored or its appearance being damaged during high-temperature drying after film formation. In addition, if the imidation catalyst has a boiling point of 40°C or higher, the possibility of volatilization before sufficient imidation proceeds can be avoided.

[0364] Examples of amine compounds suitable for use as imidation catalysts include pyridine or picoline. The above imidation catalysts may be used alone or in combination of two or more types.

[0365] Examples of dehydration catalysts include acid anhydrides such as acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, and trifluoroacetic anhydride; and carbodiimide compounds such as dicyclohexylcarbodiimide. These may be used individually or in combination of two or more types.

[0366] Since the copolymer included in the varnish of the present invention has solvent solubility, it can be made into a high-concentration varnish. The varnish of the present invention preferably contains 3 to 40 mass% of the copolymer of the present invention, more preferably contains 5 to 40 mass%, and even more preferably contains 10 to 30 mass%. The viscosity of the varnish is preferably 0.1 to 100 Pa·s, and more preferably 0.1 to 20 Pa·s. The viscosity of the varnish is a value measured at 25°C using an E-type viscometer.

[0367] In addition, the varnish of the present invention may include various additives such as inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, surfactants, leveling agents, defoaming agents, fluorescent whitening agents, crosslinking agents, polymerization initiators, and photosensitive agents, to the extent that the required characteristics of the polyimide film are not impaired.

[0368] The method for manufacturing the varnish of the present invention is not particularly limited, and known methods may be applied.

[0369] [Polyimide Film]

[0370] The polyimide film of the present invention comprises a polyimide resin formed by imidizing the amic acid portion of the imide-amic acid copolymer of the present invention. Accordingly, the polyimide film of the present invention exhibits excellent transparency and heat resistance, low yellowness, and low residual stress. The suitable physical properties of the polyimide film of the present invention are as described above.

[0371] The polyimide film of the present invention can be manufactured using a varnish formed by dissolving the aforementioned copolymer in an organic solvent.

[0372] There are no particular limitations on the method of manufacturing a polyimide film using the varnish of the present invention, and known methods may be used. For example, the varnish of the present invention may be applied or formed into a film on a smooth support such as a glass plate, a metal plate, or plastic, and then an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish may be removed by heating to obtain a copolymer film, and then the amic acid portion of the copolymer in the copolymer film may be imidized (dehydrated and cyclocyclic) by heating, and subsequently peeled off from the support to manufacture a polyimide film.

[0373] The weight-average molecular weight (Mw) of the polyimide resin included in the polyimide film of the present invention is preferably 10,000 to 800,000, more preferably 30,000 to 500,000, even more preferably 50,000 to 400,000, and even more preferably 100,000 to 300,000, in terms of the mechanical strength of the film. Meanwhile, the number-average molecular weight of the copolymer can be obtained, for example, from the standard polymethyl methacrylate (PMMA) equivalent value by gel filtration chromatography measurement.

[0374] The heating temperature when drying the varnish of the present invention to obtain a copolymer film is preferably 50 to 150°C. The heating temperature when imidizing the copolymer of the present invention by heating is preferably 200 to 500°C, more preferably 250 to 450°C, and even more preferably 300 to 400°C. In addition, the heating time is typically 1 minute to 6 hours, preferably 5 minutes to 2 hours, and more preferably 15 minutes to 1 hour.

[0375] Examples of heating atmospheres include air gas, nitrogen gas, oxygen gas, hydrogen gas, and nitrogen / hydrogen mixed gas. However, to suppress discoloration of the polyimide resin obtained, nitrogen gas with an oxygen concentration of 100 ppm or less and nitrogen / hydrogen mixed gas containing a hydrogen concentration of 0.5% or less are preferred.

[0376] Meanwhile, the imidation method is not limited to thermal imidation, and chemical imidation may also be applied.

[0377] The thickness of the polyimide film of the present invention can be appropriately selected according to the application, etc., preferably 1 to 250 μm, more preferably 5 to 100 μm, and even more preferably 5 to 50 μm. By having a thickness of 1 to 250 μm, practical use as a self-supporting film becomes possible.

[0378] The thickness of the polyimide film can be easily controlled by adjusting the solid content or viscosity of the varnish.

[0379] Polyimide Film Physical Properties

[0380] By using the imide-amide acid copolymer of the present invention, a polyimide film can be formed that has excellent transparency and heat resistance, low yellowness, and additionally exhibits low residual stress. The suitable physical properties of the film are as follows.

[0381] The total light transmittance is preferably 85% or more, more preferably 86% or more, and even more preferably 87% or more when using a film with a thickness of 10 μm.

[0382] The yellow index (YI) is preferably 15.0 or less, more preferably 13.0 or less, even more preferably 12.0 or less, and even more preferably 11.0 or less when using a film with a thickness of 10±3μm.

[0383] The glass transition temperature (Tg) is preferably 400°C or higher, more preferably 420°C or higher, and even more preferably 430°C or higher.

[0384] The residual stress is preferably 35 MPa or less, more preferably 30 MPa or less, and even more preferably 24 MPa or less.

[0385] The coefficient of linear thermal expansion (in the range of 100℃ to 400℃) is preferably 40 ppm / ℃ or less, more preferably 30 ppm / ℃ or less, and even more preferably 20 ppm / ℃ or less.

[0386] Meanwhile, the physical property values ​​described above in the present invention can be specifically measured by the method described in the examples.

[0387] The polyimide film of the present invention is suitably used as a film for various components such as color filters, flexible displays, semiconductor components, and optical components. The polyimide film of the present invention is particularly suitably used as a substrate for image display devices such as liquid crystal displays or OLED displays.

[0388] Examples

[0389] The present invention will be specifically explained below by way of examples. However, the present invention is not limited in any way by these examples.

[0390] Each physical property of the films obtained in the examples and comparative examples was measured by the method shown below.

[0391] (1) Film thickness

[0392] The film thickness was measured using a micrometer manufactured by Mitutoyo Corporation.

[0393] (2) Total light transmittance, Yellow Index (YI)

[0394] Total light transmittance and YI were measured in accordance with JIS K7105:1981 using the color and turbidity simultaneous measuring instrument “COH7700” manufactured by Nippon Color Industry Co., Ltd.

[0395] (3) Hayes

[0396] Measurements were performed in accordance with JIS K7361-1:1997 using the color and turbidity simultaneous measuring instrument “COH7700” manufactured by Nippon Jeonseok Gyojak Co., Ltd.

[0397] (4) Glass transition temperature (Tg)

[0398] Using the thermomechanical analyzer “TMA / SS6100” manufactured by Hitachi High-Tech Science Co., Ltd., the sample was heated to a temperature sufficient to remove residual stress under tensile mode conditions of sample size 3 mm × 20 mm, load 0.1 N, nitrogen air flow (flow rate 200 mL / min), and heating rate 10℃ / min, and then cooled to room temperature. After that, the elongation of the test specimen was measured under the same conditions as the treatment for removing residual stress, and the point where the inflection point of elongation was observed was determined as the glass transition temperature.

[0399] (5) Coefficient of linear thermal expansion (CTE)

[0400] Using the thermomechanical analyzer “TMA / SS6100” manufactured by Hitachi High-Tech Science Co., Ltd., the sample was heated to a temperature sufficient to remove residual stress under tensile mode conditions of sample size 3 mm × 20 mm, load 0.1 N, nitrogen air flow (flow rate 200 mL / min), and heating rate 10℃ / min, and then cooled to room temperature. After that, the elongation of the test specimen was measured under the same conditions as the treatment for removing residual stress, and the CTE from 100℃ to 400℃ was obtained.

[0401] (6) 1% weight loss temperature (Td1%)

[0402] The "TG / DTA6200" differential thermal-thermogravimetric simultaneous measurement device manufactured by Hitachi High-Tech Science Co., Ltd. was used. The sample was heated from 40 to 550°C at a heating rate of 10°C / min, and the temperature at which the weight decreased by 1% compared to the weight at 300°C was defined as the 1% weight loss temperature. A higher value for the weight loss temperature indicates superiority.

[0403] (7) Tensile strength, tensile modulus

[0404] Tensile strength and tensile modulus were measured in accordance with JIS K7127:1999 using the "Strograph VG-1E" tensile testing machine manufactured by Toyo Seiki Co., Ltd. The chuck length was 50 mm, the specimen size was 10 mm × 70 mm, and the test speed was 20 mm / min.

[0405] (8) Residual stress

[0406] Using the residual stress measuring device “FLX-2320” manufactured by KLA Tencol, the “bending amount” was measured in advance on a 4-inch silicon wafer with a thickness of 525 μm ± 25 μm, and the varnish obtained in the example and comparative example was applied using a spin coater and pre-baked. Afterwards, a heat curing treatment was performed using a hot air dryer at 400°C for 60 minutes (heating rate 5°C / min) under a nitrogen atmosphere, and a silicon wafer with a polyimide film attached having a film thickness of 6 to 15 μm after curing was produced. The bending amount of this wafer was measured using the aforementioned residual stress measuring device, and the residual stress generated between the silicon wafer and the polyimide film was evaluated.

[0407] The tetracarboxylic acid components and diamine components used in the examples and comparative examples, and their abbreviations, etc., are as follows.

[0408] Tetracarboxylic acid component

[0409] BPAF: 9,9-Bis(3,4-Dicarboxyphenyl)fluorene dihydrate (manufactured by JFE Chemical Co., Ltd.; compound represented by formula (a1))

[0410] s-BPDA: 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (Mitsubishi Chemical Corporation, compound represented by formula (a21s))

[0411] <Diamine component>

[0412] 4,4'-DDS: 4,4'-Diaminodiphenylsulfone (manufactured by Seika Corporation, compound represented by formula (b111))

[0413] TFMB: 2,2'-Bis(trifluoromethyl)benzidine (manufactured by Seika Corporation; compound represented by formula (b122))

[0414] 4-BAAB: 4-aminophenyl-4-aminobenzoate (manufactured by Japan Pure Pharmaceutical Co., Ltd.; compound represented by formula (b21))

[0415] The abbreviations of the solvents and catalysts used in the examples and comparative examples are as follows.

[0416] NMP: N-methyl-2-pyrrolidone (manufactured by Tokyo Junya Kogyo Co., Ltd.)

[0417] TEA: Triethylamine (manufactured by Kanto Chemical Co., Ltd.)

[0418] <Example 1>

[0419] 9.932 g (0.040 mol) of 4,4'-DDS and 46.380 g of NMP were added to a 500 mL five-neck round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, a nitrogen inlet tube, a cooling tube, a thermometer, and a glass end cap, and the solution was obtained by stirring at a rotation speed of 200 rpm under a nitrogen atmosphere at an internal temperature of 70°C.

[0420] To this solution, 13.753 g (0.030 mol) of BPAF and 11.595 g of NMP were added in a batch, followed by the addition of 0.152 g of TEA as an imidization catalyst. The mixture was heated with a mantle heater, and the temperature inside the reaction system was raised to 190°C over approximately 20 minutes. The leached components were collected, and the reaction system was refluxed for 1 hour while maintaining the temperature at 190°C and adjusting the rotational speed to match the increase in viscosity. Subsequently, 95.849 g of NMP was added, and the temperature inside the reaction system was cooled to 50°C to obtain a solution containing an oligomer having imide repeating structural units.

[0421] To the obtained solution, 20.595 g (0.070 mol) of s-BPDA, 13.695 g (0.060 mol) of 4-BAAB, and 16.858 g of NMP were added in a batch and stirred at 50°C for 5 hours. Afterwards, NMP was added and homogenized so that the solid content concentration was approximately 15 mass%, thereby obtaining a varnish containing a copolymer having imide repeating structural units and amic acid structural units.

[0422] The obtained varnish was subsequently applied onto a glass plate by spin coating, maintained at 80°C for 20 minutes on a hot plate, and then heated at 430°C for 60 minutes in a hot air dryer under a nitrogen atmosphere to evaporate the solvent, thereby obtaining a polyimide film. The results are shown in Table 1.

[0423] <Example 2>

[0424] A varnish with a solid content of about 15 mass% was obtained by the same method as in Example 1, except that the amount of BPAF was changed from 13.753 (0.030 mol) to 9.169 g (0.020 mol) and the amount of s-BPDA was changed from 20.595 g (0.070 mol) to 23.538 g (0.080 mol).

[0425] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0426] <Example 3>

[0427] A varnish with a solid content of about 15 mass% was obtained by the same method as in Example 1, except that the amount of BPAF was changed from 13.753 (0.030 mol) to 9.169 g (0.020 mol), the amount of s-BPDA was changed from 20.595 g (0.070 mol) to 23.538 g (0.080 mol), the amount of 4,4'-DDS was changed from 9.932 (0.040 mol) to 7.449 g (0.030 mol), and the amount of 4-BAAB was changed from 13.695 (0.060 mol) to 15.978 g (0.070 mol).

[0428] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0429] <Example 4>

[0430] A polyimide varnish with a solid content of about 15 mass% was obtained by the same method as in Example 1, except that 9.932 g (0.040 mol) of 4,4'-DDS was changed to 12.810 g (0.040 mol) of TFMB.

[0431] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0432] <Example 5>

[0433] A varnish with a solid content of about 15 mass% was obtained by the same method as in Example 4, except that the amount of BPAF was changed from 13.753 (0.030 mol) to 9.169 g (0.020 mol), the amount of s-BPDA was changed from 20.595 g (0.070 mol) to 23.538 g (0.080 mol), the amount of TFMB was changed from 12.810 g (0.040 mol) to 9.607 g (0.030 mol), and the amount of 4-BAAB was changed from 13.695 (0.060 mol) to 15.978 g (0.070 mol).

[0434] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0435] <Comparative Example 1>

[0436] 22.825 g (0.100 mol) of 4-BAAB and 167.190 g of NMP were added to a 500 mL five-neck round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, a nitrogen inlet tube, a cooling tube, a thermometer, and a glass end cap, and a solution was obtained by stirring at a rotation speed of 200 rpm under a nitrogen atmosphere at an internal temperature of 50 ℃.

[0437] To this solution, 29.422 g (0.100 mol) of s-BPDA and 41.798 g of NMP were added in bulk and stirred at room temperature for 5 hours.

[0438] After that, 87.078g of NMP was added to achieve a solid content of about 15 mass%, and the mixture was further stirred for about 1 hour to homogenize, thereby obtaining a polyamide acid (PAA) varnish.

[0439] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0440] Meanwhile, the polyamic acid included in the varnish obtained in Comparative Example 1 had only repeating amic acid structural units formed from s-BPDA and 4-BAAB.

[0441] <Comparative Example 2>

[0442] A polyamide acid (PAA) varnish with a solid content of about 15 mass% was obtained by the same method as Comparative Example 1, except that s-BPDA 29.422 g (0.100 mol) was changed to BPAF 45.843 g (0.100 mol).

[0443] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0444] Meanwhile, the polyamide acid included in the varnish obtained in Comparative Example 1 had only repeating amide acid structural units formed from BPAF and 4-BAAB.

[0445] <Comparative Example 3>

[0446] 9.932 g (0.040 mol) of 4,4'-DDS, 13.695 g (0.060 mol) of 4-BAAB, and 139.141 g of NMP were added to a 500 mL five-neck round-bottom flask equipped with a stainless steel crescent-shaped stirring blade, a nitrogen inlet tube, a cooling tube, a thermometer, and a glass end cap, and the mixture was stirred at a rotation speed of 200 rpm under a nitrogen atmosphere at an internal temperature of 50 ℃ to obtain a solution.

[0447] To this solution, 13.753 g (0.030 mol), 20.595 g (0.070 mol), and 34.785 g of NMP were added in a batch and stirred at room temperature for 5 hours. Afterward, a polyamide acid (PAA) varnish was obtained by adding NMP to achieve a solid content of approximately 15 mass% and homogenizing the mixture.

[0448] Using the obtained varnish, a film was obtained by the same method as in Example 1.

[0449] The polyamic acid included in the varnish obtained in Comparative Example 3 had only amic acid repeating structural units formed from BPAF, s-BPDA, 4,4'-DDS, and 4-BAAB.

[0450] [Table 1]

[0451]

[0452] As shown in Table 1, the polyimide film obtained from the imide-amid acid copolymer of the example having specific imide repeating structural units and amid acid structural units has low residual stress and coefficient of linear thermal expansion, excellent transparency and heat resistance, and low yellowness.

[0453] Example 1 and Comparative Example 3 have the same raw material composition constituting the polyimide film, but compared to the polyimide film of Comparative Example 3 obtained from polyamide acid, the polyimide film of Example 1 maintained transparency and low yellowness, and had particularly excellent heat resistance, as well as low residual stress and coefficient of linear thermal expansion.

Claims

Claim 1 An imide-amid acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the following formula (1), (Equation (1), X 1 It is a tetravalent aromatic group having 4 to 39 carbon atoms, and may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, and X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and Y 2 is a device represented by the following general formula (5), where s, t, and u are positive integers.) (Equation (3), Z 1 It represents a single bond, or a group represented by -O-. In Formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms. (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each independently represents a monovalent organic group having 1 to 20 carbon atoms. h, i, j, k are integers from 0 to 4.) The imide portion (IM) has a constituent unit X1A derived from a tetracarboxylic acid dianhydride and a constituent unit Y1B derived from a diamine, the amic acid portion (AM1) has a constituent unit X2A derived from a tetracarboxylic acid dianhydride and a constituent unit Y1B derived from a diamine, the amic acid portion (AM2) has a constituent unit X2A derived from a tetracarboxylic acid dianhydride and a constituent unit Y2B derived from a diamine, constituent unit X1A includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride, constituent unit X2A includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride different from constituent unit X1A, constituent unit X2A includes a constituent unit (A2) derived from an aromatic tetracarboxylic acid dianhydride (a2), and constituent unit X1A is the following It includes a constituent unit (A1) derived from a compound represented by formula (a1), and An imid-amide acid copolymer comprising at least one constituent unit (A2) selected from the group consisting of a constituent unit (A21) derived from a compound represented by the following formula (a21), a constituent unit (A22) derived from a compound represented by the following formula (a22), a constituent unit (A23) derived from a compound represented by the following formula (a23), a constituent unit (A24) derived from a compound represented by the following formula (a24), and a constituent unit (A25) derived from a compound represented by the following formula (a25). Claim 2 An imid-amide acid copolymer according to claim 1, wherein s is 1 to 50 and t is 1 to 50. Claim 3 In claim 1, the imid-amide acid copolymer in which u is 5 to 200. Claim 4 In paragraph 1, the above X 1 This is an imid-amide acid copolymer represented by the following formula (6). Claim 5 In paragraph 1, the above X 2 A, an imid-amide acid copolymer represented by the following formula (7). Claim 6 An imide-amide acid copolymer according to claim 1, wherein constituent unit Y1B comprises a constituent unit (B1) derived from a diamine (b1), and constituent unit (B1) comprises at least one selected from the group consisting of a constituent unit (B11) derived from a compound represented by the following formula (b11), a constituent unit (B12) derived from a compound represented by the following general formula (b12), and a constituent unit (B13) derived from a compound represented by the following general formula (b13), and constituent unit Y2B comprises a constituent unit (B2) derived from a compound represented by the following general formula (b2). (Equation (b12), Z 1 It represents a single bond, or a group represented by -O-. In formula (b13), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms. In formula (b2), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each represents an independent monovalent organic group having 1 to 20 carbon atoms. h, i, j, and k are integers from 0 to 4. Claim 7 delete Claim 8 In claim 6, an imid-amide acid copolymer further comprising a constituent unit (B3) derived from a compound represented by the following general formula (b3). (Equation (b3), Z 4 and Z 5 Each independently represents a divalent aliphatic group or a divalent aromatic group, and R 4 and R 5 Each independently represents a monovalent aromatic group or a monovalent aliphatic group, and R 6 and R 7 Each independently represents a monovalent aliphatic group, and R 8 and R 9 , each independently represents a monovalent aliphatic group or a monovalent aromatic group, m and n each independently represent an integer greater than or equal to 1, and the sum of m and n represents an integer between 2 and 1000. provided that R 4 and R 5 At least one of the groups represents a monovalent aromatic group.) Claim 9 In paragraph 8, the above R 4 and R 5 a, is a phenyl group, and R 6 and R 7 This is a methyl group, imid-amide acid copolymer. Claim 10 In claim 8, an imide-amid acid copolymer having a polyorganosiloxane unit content of 1 to 20 mass% in the imide-amid acid copolymer. Claim 11 delete Claim 12 A varnish formed by dissolving a copolymer described in any one of claims 1 to 6 and claims 8 to 10 in an organic solvent. Claim 13 A polyimide film comprising a polyimide resin formed by imidizing an amic acid portion in a copolymer described in any one of claims 1 to 6 and claims 8 to 10. Claim 14 In claim 13, a polyimide film having a weight-average molecular weight (Mw) of the polyimide resin of 100,000 to 300,000. Claim 15 A method for preparing an imide-amid acid copolymer having the following processes 1 and 2, wherein: Process 1: a process of reacting a tetracarboxylic acid component constituting an imide portion (IM) with a diamine component to obtain an imide oligomer; Process 2: a process of reacting the imide oligomer obtained in Process 1 with a tetracarboxylic acid component constituting an amid acid portion (AM2) and a diamine component to obtain an imide-amid acid copolymer comprising a repeating unit consisting of an imide portion (IM), an amid acid portion (AM1), and an amid acid portion (AM2), represented by the following formula (1). (Equation (1), X 1 It is a tetravalent aromatic group having 4 to 39 carbon atoms, and may have at least one bonding group selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S-, and X 2 is X 1 The group may have at least one different tetravalent aromatic group having 4 to 39 carbon atoms, selected from the group consisting of -O-, -SO2-, -CO-, -CH2-, -C(CH3)2-, -C2H4O-, and -S- as a bonding group, and Y 1 is a device represented by at least one selected from the group consisting of the following formula (2), the following general formula (3), and the following general formula (4), and Y 2 is a device represented by the following general formula (5), where s, t, and u are positive integers.) (Equation (3), Z 1 It represents a single bond, or a group represented by -O-. In Formula (4), R each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms. (Equation (5), Z 2 , Z 3 represents, respectively, a group denoted by -COO- or a group denoted by -OCO-. R 1 , R 2 , R 3 Each independently represents a monovalent organic group having 1 to 20 carbon atoms. h, i, j, k are integers from 0 to 4.) The imide portion (IM) has a constituent unit X1A derived from a tetracarboxylic acid dianhydride and a constituent unit Y1B derived from a diamine, the amic acid portion (AM1) has a constituent unit X2A derived from a tetracarboxylic acid dianhydride and a constituent unit Y1B derived from a diamine, the amic acid portion (AM2) has a constituent unit X2A derived from a tetracarboxylic acid dianhydride and a constituent unit Y2B derived from a diamine, constituent unit X1A includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride, constituent unit X2A includes a constituent unit derived from an aromatic tetracarboxylic acid dianhydride different from constituent unit X1A, constituent unit X2A includes a constituent unit (A2) derived from an aromatic tetracarboxylic acid dianhydride (a2), and constituent unit X1A is the following It includes a constituent unit (A1) derived from a compound represented by formula (a1), and A method for preparing an imide-amide acid copolymer, wherein the constituent unit (A2) comprises at least one selected from the group consisting of a constituent unit (A21) derived from a compound represented by the following formula (a21), a constituent unit (A22) derived from a compound represented by the following formula (a22), a constituent unit (A23) derived from a compound represented by the following formula (a23), a constituent unit (A24) derived from a compound represented by the following formula (a24), and a constituent unit (A25) derived from a compound represented by the following formula (a25). Claim 16 A method for preparing an imide-amid acid copolymer according to claim 15, wherein the imide oligomer obtained in process 1 has amino groups at both ends of the main chain of the molecular chain. Claim 17 A method for preparing an imide-amide acid copolymer according to claim 15, wherein in process 1, the molar ratio of the diamine component to the tetracarboxylic acid component (diamine / tetracarboxylic acid) is 1.01 to 2. Claim 18 A method for preparing an imide-amide acid copolymer, wherein, in any one of claims 15 to 17, a diamine containing a polyorganosiloxane unit is reacted after the completion of process 2.

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