Polyimide resin, polyimide varnish, polyimide film, and temporary fixing material composition

Abstract

A polyimide resin having a constituent unit (A) derived from a tetracarboxylic acid dianhydride and a constituent unit (B) derived from a diamine, the constituent unit (A) containing a constituent unit (A1) derived from a compound represented by formula (a1), and the constituent unit (B) containing a constituent unit (B1) derived from a compound represented by formula (b1) and a constituent unit (B2) derived from a compound represented by formula (b2). (Z is a diphenylfluorene structure or a hexafluorodiphenylpropane structure. X1 and X2 represent-O-,-C (CH3) 2-, or-C (CF3) 2-. > # imgabs0 #

Description

Technical Field

[0001] The invention relates to a polyimide resin, a polyimide varnish, a polyimide film and a temporary fixing material composition. Background Art

[0002] In recent years, semiconductor electronic components are being made lighter and thinner. In 2.5-dimensional or 3-dimensional semiconductor mounting, in order to achieve high integration and high density of semiconductor elements and thin semiconductor chips, the development of technology using through silicon vias (TSV: Through Silicon Via) for connection and multi-layer stacking is underway. In addition, in the field of power semiconductors, the lightweighting of semiconductor electronic circuit substrates is being carried out for the purpose of reducing conduction losses and saving energy.

[0003] As a method for thinning a semiconductor electronic circuit forming substrate, for example, the circuit non-forming surface (back side) of the semiconductor electronic circuit forming substrate is ground. In the past, during the grinding process, a back grinding tape (protective tape) was pasted on the opposite side of the grinding surface to prevent damage during the grinding process. However, the back grinding tape has insufficient heat resistance and is not suitable for the high-temperature processes in the above-mentioned TSV and power semiconductor fields.

[0004] Therefore, the following method is proposed: fix the semiconductor electronic circuit forming substrate on a supporting substrate such as a silicon wafer or a glass substrate with supporting properties by means of a temporary fixing material (adhesive layer), perform grinding, back side circuit forming processing, and then peel the processed semiconductor circuit forming substrate from the supporting substrate. Such a temporary fixing material is required to have heat resistance, peelability, and low temperature drying / low temperature adhesion properties sufficient to withstand the manufacturing process of semiconductor electronic components.

[0005] As methods for peeling off the semiconductor electronic circuit forming substrate and the supporting substrate, there are proposed: a method of dissolving the temporary fixing material in a solvent and peeling it off (for example, see Patent Document 1), and a method of irradiating the supporting substrate with laser and peeling it off. In addition, a polyimide-based material has been proposed as a temporary fixing material with excellent heat resistance (for example, see Patent Document 2).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-233679

[0009] Patent Document 2: Japanese Patent Application Publication No. 2010-254808 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] In the field of power semiconductors, the annealing process after ion implantation and the back metal process require heat resistance of 350°C or higher. On the other hand, in order to save energy and improve productivity during the process, it is preferred that the temporary fixing material can be dried and bonded at a relatively low temperature during film formation.

[0012] Furthermore, it is required to be able to be easily peeled off after the heat treatment step is completed.

[0013] When a solvent is used to strip the polyimide temporary fixing material, the solvent used to strip the polyimide is preferably a polar solvent, but since there is a concern that the solvent absorbs moisture and the solubility decreases, it is necessary to dissolve it in a solvent such as γ-butyrolactone or cyclopentanone, which is a polar solvent but has low water absorption. Therefore, it is required to be easily dissolved in solvents with various characteristics.

[0014] When the polyimide-based temporary fixing material is peeled off by laser irradiation, the polyimide-based temporary fixing material is required to have excellent properties of absorbing light of a wavelength of 355 nm in order to be able to cope with UV solid laser of a wavelength of 355 nm in particular.

[0015] As described above, there is a need for a temporary fixing material that can bond a semiconductor electronic circuit forming substrate and a supporting substrate at low temperature, can pass a semiconductor electronic component manufacturing process with a heat treatment above 350°C, and can further be stripped by various solvents and laser stripping.

[0016] Therefore, the object of the present invention is to provide a polyimide resin having a low elastic modulus, a low glass transition temperature and heat resistance, excellent solvent solubility, and a low transmittance at a wavelength of 355 nm, a polyimide film, a polyimide varnish containing the aforementioned polyimide resin, and a temporary fixing material composition containing the aforementioned polyimide resin.

[0017] Solutions for solving problems

[0018] The present inventors have found that a polyimide resin containing a combination of a specific structural unit derived from tetracarboxylic dianhydride and a specific structural unit derived from diamine can solve the above-mentioned problems, thereby completing the present invention.

[0019] That is, the present invention relates to the following <1> ~ <10> .

[0020] <1> A polyimide resin comprising a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine,

[0021] The structural unit A contains a structural unit A1 derived from a compound represented by the following formula (a1),

[0022] The structural unit B contains a structural unit B1 derived from a compound represented by the following formula (b1).

[0023]

[0024] (wherein, Z is a group represented by the following formula (1) or a group represented by the following formula (2), X 1 and X 2 Each independently represents -O-, -C(CH3)2-, -C(CF3)2-.)

[0025]

[0026] (In formula (2), R 1 and R 2 Each is independently a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms.)

[0027] <2> According to the aforementioned <1> The polyimide resin, wherein the ratio of the structural unit A1 in the structural unit A is 30 to 100 mol%.

[0028] <3> According to the aforementioned <1> or <2> The polyimide resin, wherein the ratio of the structural unit B1 in the structural unit B is 30 to 100 mol %.

[0029] <4> According to the aforementioned <1> to <3> The polyimide resin described in any one of the preceding claims, wherein

[0030] The structural unit A1 contains at least one selected from the group consisting of a structural unit A11 derived from a compound represented by the following formula (a11) and a structural unit A12 derived from a compound represented by the following formula (a12).

[0031]

[0032] <5> According to the aforementioned <1> to <4> The polyimide resin described in any one of the above, wherein the structural unit B1 contains a structural unit B11 derived from a compound represented by the following formula (b11).

[0033]

[0034] <6> According to the aforementioned <1> to <5> The polyimide resin described above, wherein the structural unit B further includes a structural unit B2 derived from a compound represented by the following formula (b2).

[0035]

[0036] (Where X 3 and X 4 Each independently represents -O-, -COO-, or -OCO-, and n is an integer of 2 to 10. )

[0037] <7> According to the aforementioned <1> to <6> The polyimide resin described above contains a structural unit represented by the following general formula (3).

[0038]

[0039] (Where L 1 and L 2 Each is independently a monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms, or a monovalent aromatic group having 6 to 10 carbon atoms, and m is an integer of 1 to 200.

[0040] <8> A polyimide varnish containing the above <1> to <7> The polyimide resin and the organic solvent described above.

[0041] <9> A polyimide film comprising the aforementioned <1> to <7> The polyimide resin described above.

[0042] <10> A temporary fixing material composition comprising the aforementioned <1> to <7> The polyimide resin described above.

[0043] Effects of the Invention

[0044] The present invention can provide a polyimide resin having a low elastic modulus, a low glass transition temperature and heat resistance, excellent solvent solubility, and a low transmittance at a wavelength of 355 nm, a polyimide film, a polyimide varnish containing the aforementioned polyimide resin, and a temporary fixing material composition containing the aforementioned polyimide resin. DETAILED DESCRIPTION

[0045] [Polyimide resin]

[0046] The polyimide resin of the present invention comprises a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine.

[0047] The structural unit A contains a structural unit (A1) derived from a compound represented by the following formula (a1),

[0048] The structural unit B contains a structural unit (B1) derived from a compound represented by the following formula (b1),

[0049]

[0050] (wherein, Z is a group represented by the following formula (1) or a group represented by the following formula (2), X 1 and X 2 Each independently represents -O-, -C(CH3)2-, -C(CF3)2-.)

[0051]

[0052] (In formula (2), R 1 and R 2 Each is independently a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms.)

[0053] The reason why the polyimide resin of the present invention has a low elastic modulus, a low glass transition temperature and heat resistance, excellent solvent solubility, and a low light transmittance at a wavelength of 355 nm is not clear, but is presumed as follows.

[0054] It is considered that by containing a structural unit derived from a specific tetracarboxylic dianhydride having an ether skeleton and a bulky skeleton (trifluoromethyl, cardo skeleton) and a structural unit derived from a non-linear aromatic diamine, the contradictory properties of heat resistance (high weight loss temperature) and low glass transition temperature are achieved, and the polyol has solubility in a solvent and light absorption at a specific wavelength.

[0055] <Structural unit A>

[0056] The structural unit A is a structural unit derived from tetracarboxylic dianhydride in the polyimide resin.

[0057] The structural unit A contains a structural unit (A1) derived from a compound represented by the following formula (a1).

[0058]

[0059] (In the formula, Z is a group represented by the following formula (1) or a group represented by the following formula (2).)

[0060]

[0061] (In formula (2), R 1 and R 2 Each is independently a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms.)

[0062] The structural unit A contains the structural unit (A1), which can improve the heat resistance of the polyimide resin and lower the glass transition temperature. In addition, the solvent solubility and the light absorption at a wavelength of 355 nm can be improved.

[0063] The compound represented by formula (a1) preferably contains at least one selected from the group consisting of the compound represented by the following formula (a11) and the compound represented by the following formula (a12), and more preferably contains at least one selected from the group consisting of the compound represented by the following formula (a11) and the compound represented by the following formula (a12).

[0064] In particular, from the viewpoint of solvent solubility, the compound represented by the following formula (a11) is preferred, and from the viewpoint of light absorption at a wavelength of 355 nm, the compound represented by the following formula (a12) is preferred.

[0065] That is, the structural unit (A1) preferably contains at least one selected from the group consisting of a structural unit (A11) derived from a compound represented by the following formula (a11) and a structural unit (A12) derived from a compound represented by the following formula (a12), and more preferably contains at least one selected from the group consisting of a structural unit (A11) derived from a compound represented by the following formula (a11) and a structural unit (A12) derived from a compound represented by the following formula (a12).

[0066] In particular, from the viewpoint of solvent solubility, the structural unit (A11) derived from the compound represented by the following formula (a11) is preferred, and from the viewpoint of light absorption at a wavelength of 355 nm, the structural unit (A12) derived from the compound represented by the following formula (a12) is preferred.

[0067]

[0068] The compound represented by formula (a11) is 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (6F-BPADA).

[0069] When the structural unit A contains the structural unit (A11), the heat resistance of the polyimide resin can be improved and the glass transition temperature can be lowered. In addition, the solvent solubility and the light absorption at a wavelength of 355 nm can be improved.

[0070] The compound represented by formula (a12) is 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (BPF-PA).

[0071] When the structural unit A contains the structural unit (A12), the heat resistance of the polyimide resin can be improved and the glass transition temperature can be lowered. In addition, the solvent solubility and the light absorption at a wavelength of 355 nm can be improved.

[0072] From the viewpoint of achieving both a low glass transition temperature and heat resistance, the structural unit (A1) preferably contains the structural unit (A11), and the structural unit (A1) is more preferably the structural unit (A11).

[0073] The structural unit A may consist of the structural unit (A1) alone, or may contain structural units other than the structural unit (A1). Preferably, it further contains a structural unit (A2) derived from a compound represented by the following formula (a2) as a structural unit other than the structural unit (A1).

[0074]

[0075] (Where L 3 , L 4 , L 5 and L 6are each independently a monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms, or a monovalent aromatic group having 6 to 10 carbon atoms, 1 and Z 2 Each independently represents a trivalent aliphatic group or a trivalent aromatic group, and m is an integer of 1 to 200.

[0076] In formula (a2), Z 1 and Z 2 The trivalent aliphatic group or trivalent aromatic group may be substituted with a fluorine atom or may contain an oxygen atom. When an oxygen atom is contained as an ether bond, the carbon number shown below refers to the total carbon number contained in the aliphatic group or aromatic group.

[0077] Examples of the trivalent aliphatic group include trivalent saturated or unsaturated aliphatic groups having 1 to 20 carbon atoms. The trivalent aliphatic group preferably has 4 to 20 carbon atoms.

[0078] Examples of the trivalent saturated aliphatic group include a group in which an alkylene group having 1 to 19 carbon atoms is bonded to a methine group, and a group in which 1 to 3 groups selected from the group consisting of alkyleneoxy groups having 1 to 19 carbon atoms are bonded to a methine group. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, a decamethylene group, and a dodecamethylene group, and examples of the alkyleneoxy group include a propyleneoxy group and a trimethyleneoxy group.

[0079] Examples of the trivalent unsaturated aliphatic group include a group in which at least one alkenylene group having 2 to 19 carbon atoms is bonded to a methine group. An alkylene group or an alkyleneoxy group may also be bonded to a methine group. Examples of the alkenylene group include vinylene and propenylene.

[0080] Examples of the trivalent aromatic group include a group in which 1 to 3 groups selected from the group consisting of arylene groups having 6 to 20 carbon atoms and aralkylene groups having 7 to 20 carbon atoms are bonded to an arylidene group having 6 to 20 carbon atoms, and a group in which 1 to 3 groups selected from the group consisting of arylene groups having 6 to 20 carbon atoms and aralkylene groups having 7 to 20 carbon atoms are bonded to a methine group. Specific examples of the arylene group include o-phenylene, m-phenylene, p-phenylene, 4,4'-biphenylene, and 2,6-naphthylene.

[0081] As Z 1 and Z 2 In particular, a group in which a trimethylene group and a methylene group are bonded to a methine group, a group in which a p-phenylene methylene group is bonded to a methine group is preferred, and a group in which a trimethylene group and a methylene group are bonded to a methine group is more preferred.

[0082] In formula (a2), as L3 ~L 6 The monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms in the aliphatic hydrocarbon may include a monovalent saturated or unsaturated aliphatic group. As the monovalent saturated aliphatic group, an alkyl group having 1 to 5 carbon atoms may be listed, for example, a methyl group, an ethyl group, a propyl group, etc. As the monovalent saturated aliphatic group, a methyl group is preferred. As the monovalent unsaturated aliphatic group, an alkenyl group having 2 to 5 carbon atoms may be listed, for example, a vinyl group, a propenyl group, etc. These groups may be substituted with fluorine atoms.

[0083] As L in formula (a2) 3 ~L 6 Examples of the monovalent aromatic group having 6 to 10 carbon atoms include an aryl group having 6 to 10 carbon atoms, an aryl group substituted with an alkyl group having 7 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. The monovalent aromatic group is preferably an aryl group, and more preferably a phenyl group.

[0084] L 3 , L 4 , L 5 and L 6 It is preferably at least one selected from the group consisting of a monovalent saturated aliphatic group and a monovalent aromatic group, more preferably at least one selected from the group consisting of a methyl group and a phenyl group, and still more preferably a methyl group.

[0085] In formula (a2), m is an integer of 1-200, and preferably an integer of 10-100.

[0086] As described above, among the compounds represented by the above formula (a2), the compounds represented by the following formula (a21) are preferred.

[0087]

[0088] (In formula (a21), L 31 and L 41 Each independently represents a methyl group or a phenyl group, and m has the same meaning as m in formula (a2), and the preferred range is also the same.)

[0089] In formula (a21), m is an integer of 1-200, and preferably an integer of 10-100.

[0090] L 31 and L 41 Each is independently a methyl group or a phenyl group, preferably a methyl group. 31 The methyl group is bonded to the silicon atom of L 41 The methyl group is preferably bonded to a 31 The phenyl group is bonded to the silicon atom as L 41 of phenyl.

[0091] The functional group equivalent of the compound represented by formula (a2) is preferably 50 to 3,000 g / mol, more preferably 100 to 1,000 g / mol, and further preferably 150 to 700 g / mol.

[0092] In addition, the functional group equivalent refers to the mass of the functional group (carboxyl group) per 1 mol of the compound represented by the formula (a2).

[0093] Among the compounds represented by the general formula (a2), examples of compounds available as commercial products include "X-22-168" series manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

[0094] When the structural unit A contains the structural unit (A2), the elastic modulus can be made low, and both a low glass transition temperature and heat resistance can be achieved.

[0095] The molar ratio of the structural unit (A1) to the structural unit (A2) in the structural unit A [(A1) / (A2)] is preferably 70 / 30 to 100 / 0, more preferably 80 / 20 to 100 / 0, further preferably 85 / 15 to 100 / 0, further preferably 85 / 15 to 99 / 1, further preferably 85 / 15 to 97 / 3, further preferably 85 / 15 to 95 / 5. When the molar ratio of the structural unit (A1) to the structural unit (A2) is 100 / 0, the structural unit A does not contain the structural unit (A2). By setting it to this molar ratio, the elastic modulus can be reduced, and a low glass transition temperature and heat resistance can be achieved.

[0096] The ratio of the structural unit (A1) in the structural unit A is preferably 30 mol% or more, more preferably 50 mol% or more, and from the viewpoint of heat resistance and solvent solubility, it is further preferably 70 mol% or more, further preferably 80 mol% or more, further preferably 85 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and preferably 100 mol% or less. The structural unit A may also be composed of the structural unit (A1) alone.

[0097] The ratio of the structural unit (A2) in the structural unit A is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, further preferably 0 to 15 mol%, further preferably 1 to 15 mol%, further preferably 3 to 15 mol%, further preferably 5 to 15 mol%.

[0098] The total ratio of the structural unit (A1) and the structural unit (A2) in the structural unit A is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and preferably 100 mol% or less. The structural unit A may also be composed of only the structural unit (A1) and the structural unit (A2).

[0099] The structural unit A may contain structural units other than the structural units (A1) and the structural units (A2). The tetracarboxylic dianhydride providing such a structural unit is not particularly limited, and examples thereof include aromatic tetracarboxylic dianhydrides other than the compound represented by formula (a1), alicyclic tetracarboxylic dianhydrides, and aliphatic tetracarboxylic dianhydrides.

[0100] In the present specification, aromatic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride containing one or more aromatic rings, alicyclic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride containing one or more alicyclic rings and no aromatic ring, and aliphatic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride containing neither an aromatic ring nor an alicyclic ring.

[0101] The structural unit which the structural unit A may optionally contain may be one kind or two or more kinds.

[0102] <Structural unit B>

[0103] The structural unit B is a structural unit derived from diamine in the polyimide resin.

[0104] The structural unit B contains a structural unit (B1) derived from a compound represented by the following formula (b1).

[0105]

[0106] (Where X 1 and X 2 Each independently represents -O-, -C(CH3)2-, -C(CF3)2-.)

[0107] When the structural unit B contains the structural unit (B1), the glass transition temperature can be particularly lowered and the solvent solubility can be improved.

[0108] In formula (b1), X 1 and X 2 Each independently represents -O-, -C(CH3)2-, and -C(CF3)2-.

[0109] X 1 It is preferably at least one selected from the group consisting of -O-, -C(CH3)2-, and -C(CF3)2-, and more preferably -O-.

[0110] X 2 It is preferably at least one selected from the group consisting of -O-, -C(CH3)2-, and -C(CF3)2-, and more preferably -O-.

[0111] Specific examples of the compound represented by formula (b1) include at least one selected from the group consisting of 1,3-bis(3-aminophenoxy)benzene (TPE-M), 1,3-bis[2-(3-aminophenyl)-2-propyl]benzene, and 1,3-bis[2-(3-aminophenyl)-2-hexafluoropropyl]benzene, and more preferably 1,3-bis(3-aminophenoxy)benzene (TPE-M). That is, it is preferred that the structural unit (B1) contains a structural unit (B11) derived from a compound represented by the following formula (b11), and it is more preferred that the structural unit (B1) is a structural unit (B11) derived from a compound represented by the following formula (b11).

[0112]

[0113] The ratio of the structural unit (B1) in the structural unit B is preferably 30 mol% or more, more preferably 50 mol% or more, and from the viewpoint of heat resistance, colorlessness, and strength, it is further preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, more preferably 95 mol% or more, and preferably 100 mol% or less. The structural unit B may also be composed of the structural unit (B1) alone.

[0114] The structural unit B may consist of the structural unit (B1) alone, or may contain structural units other than the structural unit (B1). Preferably, it further contains a structural unit (B2) derived from a compound represented by the following formula (b2) as a structural unit other than the structural unit (B1).

[0115]

[0116] (Where X 3 and X 4 Each independently represents -O-, -COO-, or -OCO-. n is an integer of 2 to 10.)

[0117] In formula (b2), X 3 and X 4 Each independently represents -O-, -COO-, or -OCO-.

[0118] X 3 It is preferably at least one selected from the group consisting of -O-, -COO-, and -OCO-, and more preferably -O-.

[0119] X 4 It is preferably at least one selected from the group consisting of -O-, -COO-, and -OCO-, and more preferably -O-. It should be noted that the group represented by -OCO- represents an aromatic ring and X 3 A group directly bonded to a carbon atom of

[0120] n is an integer of 2-10, preferably an integer of 3-6, and more preferably an integer of 4-6.

[0121] The structural unit (B2) preferably contains at least one structural unit selected from the group consisting of a structural unit (B21) derived from a compound represented by the following formula (b21), a structural unit (B22) derived from a compound represented by the following formula (b22), a structural unit (B23) derived from a compound represented by the following formula (b23), a structural unit (B24) derived from a compound represented by the following formula (b24), and a structural unit (B25) derived from a compound represented by the following formula (b25), and more preferably contains a structural unit (B21) derived from a compound represented by the following formula (b21).

[0122]

[0123] The compound represented by formula (b21) is 4,4'-hexamethylenebisoxyaniline (DA6MG), the compound represented by formula (b22) is 4,4'-pentamethylenebisoxyaniline (DA5MG), the compound represented by formula (b23) is 4,4'-trimethylenebisoxyaniline (DA3MG), the compound represented by formula (b24) is hexamethylenebis(4-aminobenzoate), and the compound represented by formula (b25) is trimethylenebis(4-aminobenzoate).

[0124] When the structural unit B contains the structural unit (B2), the elastic modulus can be reduced.

[0125] The molar ratio of the structural unit (B1) to the structural unit (B2) in the structural unit B [(B1) / (B2)] is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, and from the viewpoint of reducing the elastic modulus and improving the laser peeling property, it is further preferably 40 / 60 to 80 / 20, and further preferably 40 / 60 to 60 / 40. When the molar ratio of the structural unit (B1) to the structural unit (B2) is 100 / 0, the structural unit B does not contain the structural unit (B2).

[0126] The ratio of the structural unit (B2) in the structural unit B is preferably 0 to 70 mol%, more preferably 0 to 60 mol%, further preferably 20 to 60 mol%, and more preferably 40 to 60 mol%.

[0127] The total ratio of the structural unit (B1) and the structural unit (B2) in the structural unit B is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and preferably 100 mol% or less. The structural unit B may also be composed of only the structural unit (B1) and the structural unit (B2).

[0128] The structural unit B may contain structural units other than the structural units (B1) and (B2). The diamine providing such structural units is not particularly limited, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines other than the compound represented by formula (b1) and the compound represented by formula (b2).

[0129] In the present specification, aromatic diamine refers to a diamine containing one or more aromatic rings, alicyclic diamine refers to a diamine containing one or more alicyclic rings and no aromatic ring, and aliphatic diamine refers to a diamine containing neither an aromatic ring nor an alicyclic ring.

[0130] The structural units other than the structural unit (B1) and the structural unit (B2) optionally contained in the structural unit B may be one kind or two or more kinds.

[0131] Among the structural units other than the structural unit (B1) and the structural unit (B2), the structural unit (B3) derived from a compound represented by the following formula (b3) is preferred.

[0132]

[0133] (Where L 7 , L 8 , L 9 and L 10 are each independently a monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms, or a monovalent aromatic group having 6 to 10 carbon atoms, 3 and Z 4 Each independently represents a divalent aliphatic group or a divalent aromatic group, and m is an integer of 1 to 200.

[0134] In formula (b3), Z 3 and Z 4 The divalent aliphatic group or divalent aromatic group may be substituted with a fluorine atom or may contain an oxygen atom. When an oxygen atom is contained as an ether bond, the carbon number shown below refers to the total carbon number contained in the aliphatic group or aromatic group.

[0135] Examples of the divalent aliphatic group include divalent saturated or unsaturated aliphatic groups having 1 to 20 carbon atoms. The divalent aliphatic group preferably has 3 to 20 carbon atoms.

[0136] Examples of the divalent saturated aliphatic group include an alkylene group having 1 to 20 carbon atoms and an alkyleneoxy group. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, a decamethylene group, and a dodecamethylene group. Examples of the alkyleneoxy group include a propyleneoxy group and a trimethyleneoxy group.

[0137] Examples of the divalent unsaturated aliphatic group 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.

[0138] Examples of the divalent aromatic group include an arylene group having 6 to 20 carbon atoms and an aralkylene group having 7 to 20 carbon atoms. 4 and Z 5 Specific examples of the arylene group having 6 to 20 carbon atoms include o-phenylene, m-phenylene, p-phenylene, 4,4′-biphenylene, and 2,6-naphthylene.

[0139] As Z 3 and Z 4 , trimethylene and p-phenylene are particularly preferred, and trimethylene is more preferred.

[0140] In formula (b3), as L 7 ~L 10 The monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms in the aliphatic hydrocarbon may be a monovalent saturated or unsaturated aliphatic group. As the monovalent saturated aliphatic group, an alkyl group having 1 to 5 carbon atoms may be mentioned, for example, a methyl group, an ethyl group, a propyl group, etc. As the monovalent unsaturated aliphatic group, an alkenyl group having 2 to 5 carbon atoms may be mentioned, for example, a vinyl group, a propenyl group, etc. These groups may be substituted with fluorine atoms. As the monovalent saturated aliphatic group, a methyl group is preferred.

[0141] As L in formula (b3) 7 ~L 10 Examples of the monovalent aromatic group having 6 to 10 carbon atoms include an aryl group having 6 to 10 carbon atoms, an aryl group substituted with an alkyl group having 7 to 10 carbon atoms, and an aralkyl group having 7 to 10 carbon atoms. The monovalent aromatic group is preferably an aryl group, and more preferably a phenyl group.

[0142] L 7 , L 8 , L 9 and L 10 It is preferably at least one selected from the group consisting of a monovalent saturated aliphatic group and a monovalent aromatic group, more preferably at least one selected from the group consisting of a methyl group and a phenyl group, and still more preferably a methyl group.

[0143] In formula (b3), m is an integer of 1-200, and preferably an integer of 10-100.

[0144] As described above, among the compounds represented by the above formula (b3), the compounds represented by the following formula (b31) are preferred.

[0145]

[0146] (In formula (b31), L 71 and L81 Each independently represents a methyl group or a phenyl group, and m has the same meaning as m in formula (b3), and the preferred range is also the same.)

[0147] In formula (b31), m is an integer of 1-200, and preferably an integer of 10-100.

[0148] L 71 and L 81 Each is independently a methyl group or a phenyl group, preferably a methyl group. 71 The methyl group is bonded to the silicon atom as L 81 The methyl group is preferably bonded to a 71 The phenyl group is bonded to the silicon atom as L 81 of phenyl.

[0149] The functional group equivalent (amine equivalent) of the compound represented by formula (b3) is preferably 100 to 5,000 g / mol, more preferably 400 to 4,000 g / mol, and further preferably 500 to 3,000 g / mol.

[0150] In addition, the functional group equivalent refers to the mass of the compound represented by formula (b3) per 1 mol of the functional group (amino group).

[0151] Among the compounds represented by the general formula (b3), examples of compounds 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.

[0152] When the structural unit B contains the structural unit (B3), the elastic modulus can be lowered, and both a low glass transition temperature and heat resistance can be achieved.

[0153] The molar ratio of the total of the structural unit (B1) and the structural unit (B2) in the structural unit B to the structural unit (B3) [((B1) + (B2)) / (B3)] is preferably 70 / 30 to 100 / 0, more preferably 80 / 20 to 100 / 0, further preferably 85 / 15 to 100 / 0, further preferably 85 / 15 to 99 / 1, further preferably 85 / 15 to 97 / 3, further preferably 85 / 15 to 95 / 5. When the molar ratio of the total of the structural unit (B1) and the structural unit (B2) to the structural unit (B3) is 100 / 0, the structural unit B does not contain the structural unit (B3). By setting it to this molar ratio, the elastic modulus can be reduced, and a low glass transition temperature and heat resistance can be achieved.

[0154] The ratio of the structural unit (B3) in the structural unit B is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, and even more preferably 0 to 15 mol%. When the structural unit B contains the structural unit (B3), the ratio of the compound providing the structural unit (B3) in the structural unit B is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, and even more preferably 5 to 15 mol%.

[0155] The total ratio of the structural unit (B1), the structural unit (B2) and the structural unit (B3) in the structural unit B is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and preferably 100 mol% or less. The structural unit B may also be composed only of the structural unit (B1), the structural unit (B2) and the structural unit (B3).

[0156] <Characteristics of polyimide resin>

[0157] From the viewpoint of the mechanical strength of the obtained polyimide film, the number average molecular weight of the polyimide resin is preferably 5,000 to 300,000. The number average molecular weight of the polyimide resin can be determined from, for example, a standard polymethyl methacrylate (PMMA) conversion value measured by gel permeation chromatography.

[0158] The polyimide resin may contain structures other than the polyimide chain (structure in which the structural unit A and the structural unit B are bonded via an imide bond). Examples of structures other than the polyimide chain that may be contained in the polyimide resin include structures containing an amide bond.

[0159] The polyimide resin preferably contains a polyimide chain (a structure in which structural unit A and structural unit B are bonded with an imide bond) as a main structure. Therefore, the ratio of the polyimide chain in the polyimide resin is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 90% by mass or more, and further preferably 99% by mass or more. In addition, it is preferably 100% by mass or less. It is further preferably 100% by mass, and the polyimide resin may also be composed only of polyimide chains.

[0160] The polyimide resin preferably contains a structural unit represented by the following general formula (3).

[0161]

[0162] (Where L 1 and L 2 Each is independently a monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms, or a monovalent aromatic group having 6 to 10 carbon atoms, and m is an integer of 1 to 200.

[0163] In formula (3), as L 1and L 2 The monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms in the aliphatic hydrocarbon may include a monovalent saturated or unsaturated aliphatic group. As the monovalent saturated aliphatic group, an alkyl group having 1 to 5 carbon atoms may be listed, for example, a methyl group, an ethyl group, a propyl group, etc. As the monovalent saturated aliphatic group, a methyl group is preferred. As the monovalent unsaturated aliphatic group, an alkenyl group having 2 to 5 carbon atoms may be listed, for example, a vinyl group, a propenyl group, etc. These groups may also be substituted by fluorine atoms.

[0164] As L in formula (3) 1 and L 2 The monovalent aromatic group having 6 to 10 carbon atoms in the group may be, for example, an aryl group having 6 to 10 carbon atoms, an aryl group substituted with an alkyl group having 7 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, etc. The monovalent aromatic group is preferably an aryl group, and more preferably a phenyl group.

[0165] L 1 and L 2 It is preferably at least one selected from the group consisting of a monovalent saturated aliphatic group and a monovalent aromatic group, more preferably at least one selected from the group consisting of a methyl group and a phenyl group, and more preferably a methyl group.

[0166] In formula (3), m is an integer of 1-200, preferably an integer of 10-100.

[0167] The structural unit represented by formula (3) can be introduced into the polyimide resin by any method, and may be present in any of the aforementioned structural unit A and the aforementioned structural unit B, or may be bonded to the aforementioned structural unit without an imide bond, but is preferably present in any one of the aforementioned structural unit A and the aforementioned structural unit B, or both, and more preferably present in the aforementioned structural unit A.

[0168] When the structural unit represented by formula (3) is present in structural unit A, the structural unit is preferably structural unit (A2). When the structural unit represented by formula (3) is present in structural unit B, the structural unit is preferably structural unit (B3).

[0169] [Method for producing polyimide resin]

[0170] The method for producing the polyimide resin of the present invention is not particularly limited, but preferably a method for obtaining the polyimide resin by reacting a compound (tetracarboxylic acid component) providing the structural unit A with a compound (diamine component) providing the structural unit B. According to this method, the polyimide resin can be directly obtained from the tetracarboxylic acid component and the diamine component.

[0171] According to the present production method, the polyimide resin can be produced by reacting a tetracarboxylic acid component containing a compound providing the structural unit (A1) and a diamine component containing a compound providing the structural unit (B1).

[0172] As the compound providing the structural unit (A1), the compound shown in formula (a1) can be cited, but it is not limited thereto, and its derivatives can also be provided within the scope of providing the same structural unit. As the derivative, tetracarboxylic acid corresponding to the tetracarboxylic dianhydride shown in formula (a1) and the alkyl ester of the tetracarboxylic acid can be cited. Among them, the tetracarboxylic dianhydride shown in formula (a1) is preferred.

[0173] When the tetracarboxylic acid component contains a compound providing a structural unit (A2), the compound provided by the structural unit (A2) may be a compound shown in formula (a2), but is not limited thereto, and may be a derivative thereof within the scope of providing the same structural unit. As the derivative, tetracarboxylic acids corresponding to the tetracarboxylic dianhydride shown in formula (a2) and alkyl esters of the tetracarboxylic acids may be listed. Among them, the tetracarboxylic dianhydride shown in formula (a2) is preferred.

[0174] The molar ratio [(A1) / (A2)] of the compound providing the structural unit (A1) and the compound providing the structural unit (A2) in the tetracarboxylic acid component is preferably 70 / 30 to 100 / 0, more preferably 80 / 20 to 100 / 0, further preferably 85 / 15 to 100 / 0, further preferably 85 / 15 to 99 / 1, further preferably 85 / 15 to 97 / 3, further preferably 85 / 15 to 95 / 5. When the molar ratio is 100 / 0, the tetracarboxylic acid component does not contain the compound providing the structural unit (A2). By setting it to this molar ratio, the elastic modulus can be reduced, and low glass transition temperature and heat resistance can be taken into account.

[0175] The ratio of the compound providing the structural unit (A1) in the tetracarboxylic acid component is preferably 30 mol% or more, more preferably 50 mol% or more, and from the viewpoint of heat resistance and solvent solubility, it is further preferably 70 mol% or more, further preferably 80 mol% or more, further preferably 85 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and preferably 100 mol% or less. The tetracarboxylic acid component may also be composed only of the compound providing the structural unit (A1).

[0176] The ratio of the compound providing the structural unit (A2) in the tetracarboxylic acid component is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, further preferably 0 to 15 mol%, further preferably 1 to 15 mol%, further preferably 3 to 15 mol%, further preferably 5 to 15 mol%.

[0177] The total ratio of the compound providing the structural unit (A1) and the compound providing the structural unit (A2) in the tetracarboxylic acid component is more preferably 90 mol% or more, and is preferably 100 mol% or less. The tetracarboxylic acid component may be composed only of the compound providing the structural unit (A1) and the compound providing the structural unit (A2).

[0178] The tetracarboxylic acid component may contain tetracarboxylic dianhydrides other than the compound providing the structural unit (A1) and the compound providing the structural unit (A2). Such tetracarboxylic dianhydrides are not particularly limited, and examples thereof include aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aliphatic tetracarboxylic dianhydrides other than the compound represented by formula (a1).

[0179] As the tetracarboxylic dianhydride which the tetracarboxylic acid component optionally contains, one type may be used, or two or more types may be used.

[0180] As the compound providing the structural unit (B1), the compound represented by formula (b1) can be cited, but it is not limited thereto, and its derivatives can also be cited within the scope of providing the same structural unit. As the derivative, diisocyanates corresponding to the compound (diamine) represented by formula (b1) can be cited. Among them, the compound represented by formula (b1) (i.e., diamine) is preferred.

[0181] The diamine component may contain a structural unit other than the compound providing the structural unit (B1), and preferably further contains a compound providing the structural unit (B2) derived from the compound represented by the formula (b2).

[0182] When the tetracarboxylic acid component contains a compound providing a structural unit (B2), the compound provided by the structural unit (B2) may be a compound represented by formula (b2), but is not limited thereto and may be a derivative thereof within the scope of providing the same structural unit. As such a derivative, a diisocyanate corresponding to the compound (diamine) represented by formula (b2) may be listed. Among them, the compound (i.e., diamine) represented by formula (b2) is preferred.

[0183] The molar ratio [(B1) / (B2)] of the compound providing the structural unit (B1) to the compound providing the structural unit (B2) in the diamine component is preferably 30 / 70 to 100 / 0, more preferably 40 / 60 to 100 / 0, and from the viewpoint of reducing the elastic modulus and improving the laser peeling property, it is further preferably 40 / 60 to 80 / 20, and further preferably 40 / 60 to 60 / 40. When the above molar ratio is 100 / 0, the diamine component does not contain the compound providing the structural unit (B2).

[0184] The ratio of the compound providing the structural unit (B1) in the diamine component is preferably 30 mol% or more, more preferably 50 mol% or more, and from the viewpoint of heat resistance, colorlessness, and strength, it is further preferably 70 mol% or more, further preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and preferably 100 mol% or less. The diamine component may be composed only of the compound providing the structural unit (B1).

[0185] The ratio of the compound providing the structural unit (B2) in the diamine component is preferably 0 to 70 mol%, more preferably 0 to 60 mol%, further preferably 20 to 60 mol%, and further preferably 40 to 60 mol%.

[0186] The total ratio of the compound providing the structural unit (B1) and the compound providing the structural unit (B2) in the diamine component is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and preferably 100 mol% or less. The diamine component may be composed only of the compound providing the structural unit (B1) and the compound providing the structural unit (B2).

[0187] The diamine component may contain diamines other than the compound providing the structural unit (B1) and the compound providing the structural unit (B2). The diamine providing such a structural unit is not particularly limited, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines other than the compound represented by formula (b1) and the compound represented by formula (b2).

[0188] The structural unit (B1) and the diamine other than the structural unit (B2) which the diamine component may contain may be one kind or two or more kinds.

[0189] Among diamines other than the compound providing the structural unit (B1) and the compound providing the structural unit (B2), the compound providing the structural unit (B3) is preferred.

[0190] When the tetracarboxylic acid component contains a compound providing a structural unit (B3), the compound provided by the structural unit (B3) may be a compound represented by formula (b3), but is not limited thereto and may be a derivative thereof within the scope of providing the same structural unit. As such a derivative, a diisocyanate corresponding to the compound (diamine) represented by formula (b3) may be listed. Among them, the compound (i.e., diamine) represented by formula (b3) is preferred.

[0191] The molar ratio of the total of the compound providing the structural unit (B1) and the compound providing the structural unit (B2) in the diamine component to the compound providing the structural unit (B3) [((B1) + (B2)) / (B3)] is preferably 70 / 30 to 100 / 0, more preferably 80 / 20 to 100 / 0, further preferably 85 / 15 to 100 / 0, further preferably 85 / 15 to 99 / 1, further preferably 85 / 15 to 97 / 3, further preferably 85 / 15 to 95 / 5. When the molar ratio of the total of the compound providing the structural unit (B1) and the compound providing the structural unit (B2) to the compound providing the structural unit (B3) is 100 / 0, the diamine component does not contain the compound providing the structural unit (B3). By setting it to this molar ratio, the elastic modulus of the obtained polyimide resin can be reduced, and a low glass transition temperature and heat resistance can be achieved at the same time.

[0192] The ratio of the compound providing the structural unit (B3) in the diamine component is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, and even more preferably 0 to 15 mol%. When the diamine component contains a compound providing the structural unit (B3), the ratio of the compound providing the structural unit (B3) in the diamine component is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, and even more preferably 5 to 15 mol%.

[0193] The total ratio of the compound providing the structural unit (B1), the compound providing the structural unit (B2), and the compound providing the structural unit (B3) in the diamine component is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and preferably 100 mol% or less. The diamine component may be composed only of the compound providing the structural unit (B1), the compound providing the structural unit (B2), and the compound providing the structural unit (B3).

[0194] In the present invention, the feed amount ratio of the tetracarboxylic acid component and the diamine component used for the production of the polyimide resin is preferably 0.9 to 1.1 mol of the diamine component relative to 1 mol of the tetracarboxylic acid component.

[0195] In addition, in the present invention, in the manufacture of the polyimide resin, in addition to using the aforementioned tetracarboxylic acid component and diamine component, an end-capping agent may also be used. The end-capping agent is preferably a monoamine or a dicarboxylic acid. The feed amount of the end-capping agent introduced is preferably 0.0001 to 0.1 mole, and more preferably 0.001 to 0.06 mole, relative to 1 mole of the tetracarboxylic acid component. As a monoamine end-capping agent, for example, methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc., preferably benzylamine, aniline. As a dicarboxylic acid end-capping agent, a dicarboxylic acid is preferably used, a part of which can be ring-closed. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. are mentioned, and phthalic acid and phthalic anhydride are preferable.

[0196] There is no restriction|limiting in particular about the method for making the said tetracarboxylic acid component and a diamine component react, A well-known method can be used.

[0197] Specific reaction methods include: (1) a method in which a tetracarboxylic acid component, a diamine component, and a reaction solvent are placed in a reactor, stirred at 0 to 80° C. for 0.5 to 30 hours, and then the temperature is raised to carry out an imidization reaction; (2) a method in which a diamine component and a reaction solvent are placed in a reactor and dissolved, and then a tetracarboxylic acid component is placed, and if necessary, stirred at room temperature of 0 to 80° C. for 0.5 to 30 hours, and then the temperature is raised to carry out an imidization reaction; (3) a method in which a tetracarboxylic acid component, a diamine component, and a reaction solvent are placed in a reactor, and then the temperature is immediately raised to carry out an imidization reaction.

[0198] The organic solvent (reaction solvent) used in the production of the polyimide resin may be any solvent as long as it does not inhibit the imidization reaction and can dissolve the produced polyimide resin, and examples thereof include aprotic solvents, phenolic solvents, ether solvents, carbonate solvents, and the like.

[0199] Specific examples of the aprotic solvent include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethyl urea, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; lactone solvents such as γ-butyrolactone (GBL) and γ-valerolactone; glycol solvents such as diethylene glycol dimethyl ether, triethylene glycol, and triethylene glycol dimethyl ether; phosphorus-containing amide solvents such as hexamethylphosphoric acid amide and hexamethylphosphine triamide; sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and cyclopentanone; ketone solvents such as acetone, cyclopentanone, cyclohexanone, and methylcyclohexanone; amine solvents such as picoline and pyridine; and ester solvents such as acetic acid (2-methoxy-1-methylethyl ester).

[0200] Specific examples of the phenolic solvent include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol.

[0201] Specific examples of the ether solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, and 1,4-dioxane.

[0202] Moreover, as a specific example of a carbonate-based solvent, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, etc. are mentioned.

[0203] Among the above reaction solvents, aprotic solvents are preferred, amide solvents and lactone solvents are more preferred, and lactone solvents are more preferred. In addition, the above reaction solvents may be used alone or in combination of two or more.

[0204] The imidization reaction is preferably carried out using a Dean-Stark apparatus or the like, while removing water generated during production. By carrying out such an operation, the degree of polymerization and the imidization ratio can be increased.

[0205] A known imidization catalyst can be used for the imidization reaction. Examples of the imidization catalyst include a base catalyst and an acid catalyst.

[0206] Examples of the base catalyst include organic base catalysts such as pyridine, quinoline, isoquinoline, α-methylpyridine, β-methylpyridine, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine (TEA), tripropylamine, tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, and N,N-diethylaniline; and inorganic base catalysts such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, and sodium hydrogen carbonate.

[0207] Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, hydroxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. The imidization catalysts may be used alone or in combination of two or more.

[0208] Among the above, from the viewpoint of operability, it is preferred to use a base catalyst, more preferably to use an organic base catalyst, and still more preferably to use at least one selected from the group consisting of triethylamine and triethylenediamine.

[0209] From the viewpoint of reaction rate and suppression of gelation, etc., the temperature of the imidization reaction is preferably 120 to 250° C., and more preferably 160 to 200° C. The reaction time is preferably 0.5 to 10 hours after the start of distillation of generated water.

[0210] [Polyimide varnish and temporary fixing material composition]

[0211] The polyimide varnish of the present invention is obtained by dissolving the polyimide resin of the present invention in an organic solvent. That is, the polyimide varnish of the present invention contains the polyimide resin of the present invention and an organic solvent, and the polyimide resin is dissolved in the organic solvent.

[0212] The organic solvent is not particularly limited as long as it dissolves the polyimide resin. The above-mentioned compounds as reaction solvents used in the production of the polyimide resin are preferably used alone or in combination of two or more.

[0213] The polyimide varnish of the present invention may be a polyimide solution itself obtained by dissolving a polyimide resin obtained by a polymerization method in a reaction solvent, or may be a polyimide solution obtained by further adding a solvent to the polyimide solution and diluting the polyimide solution.

[0214] The polyimide resin of the present invention has solvent solubility, so it can be a high-concentration varnish that is stable at room temperature. The polyimide varnish of the present invention preferably contains 5 to 40% by mass of the polyimide resin of the present invention, and more preferably contains 10 to 30% by mass. The viscosity of the polyimide varnish is preferably 1 to 200 Pa·s, and more preferably 1 to 100 Pa·s. The viscosity of the polyimide varnish is a value measured at 25°C using an E-type viscometer.

[0215] In addition, the polyimide varnish of the present invention may also contain various additives such as inorganic fillers, adhesion promoters, release agents, flame retardants, ultraviolet stabilizers, surfactants, leveling agents, defoaming agents, fluorescent whitening agents, crosslinking agents, polymerization initiators, and photosensitizers within the range that the required properties of the polyimide resin and the temporary fixing material are not impaired.

[0216] The method for producing the polyimide varnish of the present invention is not particularly limited, and a known method can be employed.

[0217] The temporary fixing material composition of the present invention contains the aforementioned polyimide resin. Therefore, the aforementioned polyimide varnish can also be used as the temporary fixing material composition.

[0218] The temporary fixing material composition of the present invention is preferably a polyimide resin of the present invention dissolved in an organic solvent. That is, the temporary fixing material composition of the present invention preferably contains the polyimide resin of the present invention and an organic solvent, and more preferably the polyimide resin is dissolved in the organic solvent.

[0219] The organic solvent is not particularly limited as long as it is an organic solvent in which the polyimide resin can be dissolved. The above-mentioned compounds as reaction solvents used in the production of the polyimide resin are preferably used alone or in combination of two or more.

[0220] The temporary fixing material composition of the present invention may be a polyimide solution obtained by dissolving a polyimide resin obtained by a polymerization method in a reaction solvent, or may be a polyimide solution obtained by further adding a solvent to dilute the polyimide solution.

[0221] The polyimide resin of the present invention has solvent solubility, so it can be a high-concentration temporary fixing material composition that is stable at room temperature. The temporary fixing material composition of the present invention preferably contains 5 to 40% by mass of the polyimide resin of the present invention, and more preferably contains 10 to 30% by mass. The viscosity of the temporary fixing material composition is preferably 1 to 200 Pa·s, and more preferably 1 to 100 Pa·s. The viscosity of the temporary fixing material composition is a value measured at 25°C using an E-type viscometer.

[0222] Furthermore, the temporary fixing material composition of the present invention may contain various additives such as inorganic fillers, adhesion promoters, release agents, flame retardants, ultraviolet stabilizers, surfactants, leveling agents, defoaming agents, fluorescent whitening agents, crosslinking agents, polymerization initiators, and photosensitizers within the range that the required properties of the polyimide resin and the temporary fixing material are not impaired.

[0223] [Polyimide film]

[0224] The polyimide film of the present invention contains the above-mentioned polyimide resin. Therefore, the polyimide film of the present invention has a low elastic modulus, a low glass transition temperature and heat resistance, excellent solvent solubility, and a low light transmittance at a wavelength of 355 nm.

[0225] The polyimide film of the present invention preferably has the following physical properties.

[0226] The light transmittance at a wavelength of 355 nm when the thickness is 30 μm is preferably 1.0% or less, more preferably 0.5% or less, further preferably 0.2% or less, and further preferably 0.1% or less.

[0227] The glass transition temperature is preferably 210°C or lower, more preferably 180°C or lower, and further preferably 160°C or lower.

[0228] The 5% weight loss temperature is preferably 450°C or higher, more preferably 480°C or higher, and further preferably 500°C or higher.

[0229] The weight reduction rate when the alloy is kept at 350° C. for 60 minutes is preferably 1.0% or less, more preferably 0.7% or less, and even more preferably 0.4% or less.

[0230] The tensile elastic modulus when the thickness is 30 μm is preferably 3.0 GPa or less, more preferably 2.6 GPa or less, and further preferably 2.3 GPa or less.

[0231] It should be noted that the above-mentioned physical property values ​​of the present invention can be specifically measured according to the methods described in the Examples.

[0232] The polyimide film of the present invention has a low elastic modulus, a low glass transition temperature and heat resistance, excellent solvent solubility, and a small light transmittance at a wavelength of 355 nm, of the polyimide resin mentioned above. Therefore, the polyimide film of the present invention can be used as a temporary fixing material by forming the polyimide film of the present invention on a semiconductor electronic circuit forming substrate using the above method.

[0233] The thickness of the polyimide film of the present invention is not particularly limited, but when used as a temporary fixing material, it is preferably 1 to 250 μm, more preferably 5 to 100 μm, further preferably 8 to 80 μm, and even more preferably 10 to 80 μm.

[0234] The thickness of the polyimide film can be easily controlled by adjusting the solid content concentration and viscosity of the varnish. When the polyimide film is used as a temporary fixing material, the thickness can be easily controlled by adjusting the solid content concentration and viscosity of the temporary fixing material composition.

[0235] The method for producing the polyimide film of the present invention is not particularly limited, and a known method can be used. For example, a method of applying the varnish of the present invention on a support and heating the varnish can be cited. Specifically, a method of removing organic solvents such as a reaction solvent and a dilution solvent contained in the varnish by heating after applying the varnish on a smooth support such as a glass plate, a metal plate, or a plastic can be cited. The polyimide varnish containing a polyimide resin of the present invention is preferably used as a raw material for a temporary fixing material. When the polyimide film of the present invention is used as a temporary fixing material, a semiconductor electronic circuit forming substrate is used as the aforementioned support.

[0236] Examples of the coating method include known coating methods such as spin coating, slit coating, and blade coating. Among them, spin coating is preferred from the viewpoint of improving film uniformity and workability.

[0237] As a method for removing the organic solvent contained in the varnish by heating, it is preferred to evaporate the organic solvent at a temperature of 150° C. or less to make it non-viscous, and then dry it at a temperature above the boiling point of the organic solvent used (not particularly limited, preferably 200 to 500° C.). In addition, it is preferred to dry it in an air atmosphere or a nitrogen atmosphere. The pressure of the drying atmosphere may be reduced pressure, normal pressure, or pressurized pressure.

[0238] The method of peeling the polyimide film formed on the support from the support is not particularly limited, and examples thereof include: a laser release method, a method using a sacrificial layer for peeling (a method of pre-coating a release agent on the surface of the support), and a method of adding a peeling agent. It should be noted that when the polyimide film of the present invention is used as a temporary fixing material, since the semiconductor electronic circuit forming substrate and the support substrate are peeled off and the temporary fixing material is finally removed, a method of dissolving the polyimide film as a temporary fixing material with a solvent, and a method of peeling by irradiating a laser from the support substrate side are used.

[0239] Example

[0240] The present invention is specifically described below with reference to the following examples, but the present invention is not limited by these examples in any way.

[0241] [Physical properties and evaluation of polyimide resin]

[0242] The physical properties of the polyimide films obtained in Examples and Comparative Examples were measured and evaluated in accordance with the following methods, and the polyimide resins were evaluated.

[0243] (1) Thickness of polyimide film

[0244] The thickness of the polyimide film was measured using a digital measuring instrument "SA-S110 / 03N" manufactured by CITIZEN FINE DEVICE CO., LTD.

[0245] (2) Total light transmittance and yellowness index (YI)

[0246] The total light transmittance and YI of the polyimide film are for the polyimide film after being peeled off from the glass plate. The total light transmittance is based on JIS K7361-1:1997, and the YI is based on ASTM E313-05 (D light source, 65°). Both are measured using the color / turbidity simultaneous measuring instrument "COH7700" manufactured by Nippon Denshoku Industries Co., Ltd.

[0247] The greater the total light transmittance of the polyimide film, the better the transparency of the polyimide resin. The greater the YI of the polyimide film, the better the colorlessness of the polyimide resin.

[0248] (3) Transmittance at a wavelength of 355 nm

[0249] The light transmittance of the polyimide film at a wavelength of 355 nm was determined by the following method for the polyimide film after it was peeled off from the glass plate.

[0250] The measurement was performed using an ultraviolet-visible-near-infrared spectrophotometer "UV-3600 Plus + MPC-603A" manufactured by Shimadzu Corporation. The smaller the value of the light transmittance at a wavelength of 355 nm, the better the LLO (laser detachment) peelability.

[0251] It should be noted that in Table 1, “<0.1” means “less than 0.1%”.

[0252] (4) Glass transition temperature (Tg)

[0253] The TMA measurement was performed using a thermomechanical analyzer "TMA 7100C" manufactured by Hitachi High-Tech Science Co., Ltd., with a sample size of 4 mm × 20 mm, tensile mode, a load of 50 mN, and a heating rate of 10°C / min. The temperature was raised from 40°C to 300°C, and the inflection point where the elongation was observed was set as the glass transition temperature (Tg) by extrapolation.

[0254] (5) 5% weight loss temperature (Td5%)

[0255] A differential thermal and thermogravimetric simultaneous measuring device "NEXTASTA200RV" manufactured by Hitachi High-Tech Science Co., Ltd. was used. The sample (polyimide film) was heated from 40°C to 50°C at a heating rate of 10°C / min, maintained at 150°C for 30 minutes, and then heated to 500°C after removing moisture. The temperature at which the weight is reduced by 5% compared to the weight after maintaining at 150°C for 30 minutes is defined as the 5% weight reduction temperature. The larger the numerical value (temperature) of the weight reduction temperature, the better the heat resistance. It should be noted that in Table 1, Td5% exceeding 500°C (weight reduction at 500°C is still less than 5%) is recorded as ">500".

[0256] (6) Weight reduction rate (%)

[0257] A differential thermal and thermogravimetric simultaneous measuring device "NEXTASTA200RV" manufactured by Hitachi High-Tech Science Co., Ltd. was used. The sample (polyimide film) was heated from 40°C to 150°C at a heating rate of 10°C / min, kept at 150°C for 30 minutes, and heated to 350°C after removing moisture. The weight at 350°C was used as a reference, and the weight reduction ratio after keeping at 350°C for 60 minutes was set as the weight reduction rate. The smaller the weight reduction rate, the better the heat resistance.

[0258] (7) Tensile elastic modulus and tensile strength

[0259] The tensile modulus and tensile strength of the polyimide film were measured using a tensile tester "Strograph VG-1E" manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K7127: 1999. The lower the elastic modulus, the better the adhesion when used as a temporary fixing material, which is preferred.

[0260] (8) Solvent solubility (after post-baking)

[0261] The polyimide film was impregnated with GBL (γ-butyrolactone) and cyclohexanone at room temperature (25° C.), and the solubility was evaluated while stirring with a magnetic stirrer. The concentration during the evaluation was 0.2% (w / w). The evaluation results are as follows.

[0262] It is preferably soluble in a solvent with low water absorption such as GBL (γ-butyrolactone) or cyclohexanone, because a solvent with low water absorption can be used in the stripping step, and the stripping is less susceptible to humidity or water.

[0263] A: Dissolved within 1 hour.

[0264] B: Did not dissolve within 1 hour, but dissolved within 24 hours.

[0265] C: Did not dissolve within 24 hours, but dissolved within 72 hours.

[0266] D: Not dissolved within 72 hours (insoluble).

[0267] (9) Solvent solubility (after annealing at 350°C for 1 hour)

[0268] After making a polyimide film on a silicon wafer according to the method described in the example, the film was heated at 350°C for 60 minutes in a hot air dryer under a nitrogen atmosphere, and then the solubility was evaluated. The film was impregnated with GBL (γ-butyrolactone) and cyclohexanone at room temperature (25°C), stirred with a magnetic stirrer, and the solubility was evaluated. It should be noted that the sample size during the evaluation was set to 10mm×20mm, and the amount of each solvent was set to 50mL. The evaluation results are as follows.

[0269] It is preferably soluble in a solvent with low water absorption such as GBL (γ-butyrolactone) or cyclohexanone, because a solvent with low water absorption can be used in the stripping step, and the stripping is less susceptible to humidity or water.

[0270] A: Dissolved within 1 hour.

[0271] B: Did not dissolve within 1 hour, but dissolved within 24 hours.

[0272] C: Did not dissolve within 24 hours, but dissolved within 72 hours.

[0273] D: Not dissolved within 72 hours (insoluble).

[0274] <Abbreviations of ingredients, etc.>

[0275] The tetracarboxylic acid component and the diamine component used in the Examples and Comparative Examples, and their abbreviations are as follows.

[0276] (Tetracarboxylic acid component)

[0277] 6F-BPADA: 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (a compound represented by formula (a11), manufactured by Air Water Performance Chemical Co., Ltd.)

[0278] BPF-PA: 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride (a compound represented by formula (a12), manufactured by JFE Chemical Co., Ltd.)

[0279] X-22-168AS: Bi-terminal carboxylic anhydride modified silicone (25℃ viscosity: 160mm 2 / s, functional group equivalent: 518 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd., (compound represented by formula (a21))

[0280] BPADA: 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (compound represented by the following formula, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0281]

[0282] HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (a compound represented by the following formula, manufactured by Mitsubishi Gas Chemical Co., Ltd.)

[0283]

[0284] (Diamine component)

[0285] TPE-M: 1,3-bis(3-aminophenoxy)benzene (compound represented by formula (b11), manufactured by SEIKA Corporation)

[0286] DA5MG: 4,4'-pentamethylenedioxyaniline (compound represented by formula (b22), manufactured by SEIKA Co., Ltd.)

[0287] The abbreviations of the solvents and catalysts used in Examples and Comparative Examples are as follows.

[0288] GBL: γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation)

[0289] TEA: triethylamine (manufactured by Kanto Chemical Co., Ltd.)

[0290] <Manufacture of polyimide resin, polyimide varnish and polyimide film>

[0291] Example 1

[0292] In a 500 mL 5-necked round-bottom flask equipped with a stainless steel half-moon-shaped stirring blade, a nitrogen inlet tube, a Dean-Stark apparatus equipped with a condenser, a thermometer, and a glass end cap, 29.234 g (0.100 mol) of TPE-M and 136.802 g of GBL were added. Under a nitrogen atmosphere, the temperature in the system was 70° C. and the mixture was stirred at a rotation speed of 200 rpm to obtain a solution.

[0293] After adding 6F-BPADA 62.844g (0.100 mol) and GBL 25.650g at once to the solution, 0.506g of TEA and 8.550g of GBL as an imidization catalyst were added, and the temperature in the reaction system was raised to 190°C in about 20 minutes by heating with a heating mantle. The temperature in the reaction system was maintained at 190°C while collecting the distilled components, and refluxed for 3 hours. Thereafter, 182.894g of GBL was added in such a way that the solid content concentration became 20% by mass, and the temperature in the reaction system was cooled to 50°C to obtain a polyimide varnish containing a polyimide resin.

[0294] The obtained polyimide varnish was then applied to a silicon wafer by spin coating, kept on a hot plate at 120°C for 20 minutes, and then heated in a hot air dryer at 220°C for 30 minutes in an air atmosphere to evaporate the solvent, thereby obtaining a polyimide film. The physical properties and evaluation results of the film are shown in Table 1.

[0295] Examples 2, 3, 5 and Comparative Example 2

[0296] In Example 1, a solution containing a polyimide resin was obtained in the same manner as in Example 1, except that 6F-BPADA was changed to a tetracarboxylic acid component shown in Table 1.

[0297] To the obtained solution, GBL was added so as to have a solid content concentration of 20% by mass and the solution was homogenized to obtain a polyimide varnish containing a polyimide resin.

[0298] The obtained polyimide varnish was then applied to a silicon wafer by spin coating, maintained on a hot plate at 120°C for 20 minutes, and then heated in a hot air dryer at 220°C for 30 minutes in an air atmosphere to evaporate the solvent, thereby obtaining a polyimide film. The physical properties and evaluation results of the film are shown in Table 1.

[0299] Example 4

[0300] In Example 1, a solution containing a polyimide resin was obtained in the same manner as in Example 1 except that TPE-M was changed to a diamine component shown in Table 1.

[0301] To the obtained solution, GBL was added so as to have a solid content concentration of 20% by mass and the solution was homogenized to obtain a polyimide varnish containing a polyimide resin.

[0302] The obtained polyimide varnish was then applied to a silicon wafer by spin coating, maintained on a hot plate at 120°C for 20 minutes, and then heated in a hot air dryer at 220°C for 30 minutes in an air atmosphere to evaporate the solvent, thereby obtaining a polyimide film. The physical properties and evaluation results of the film are shown in Table 1.

[0303] Comparative Example 1

[0304] In Example 1, a solution containing a polyimide resin was obtained in the same manner as in Example 1, except that 6F-BPADA was changed to a tetracarboxylic acid component shown in Table 1.

[0305] GBL was added to the obtained solution so that the solid content concentration was 20% by mass, but the compatibility with GBL was poor and it could not be homogenized. Therefore, NMP was added to the obtained solution so that the solid content concentration was 20% by mass to make it homogenized, and a polyimide varnish containing a polyimide resin was obtained.

[0306] [Table 1]

[0307]

[0308] As shown in Table 1, the polyimide resin (polyimide film) of the example has a small light transmittance at a wavelength of 355 nm, a low glass transition temperature, a high weight loss temperature, a low elastic modulus, and excellent solvent solubility in GBL and cyclohexanone.

[0309] It can be seen from this that the polyimide resin of the present invention has a low elastic modulus and a low glass transition temperature, so it is excellent in low-temperature adhesion. In addition, the polyimide resin of the present invention shows a high weight loss temperature, so it also has heat resistance in the manufacturing process of semiconductor electronic components. Furthermore, it can be seen that the light transmittance of the polyimide resin of the present invention at a wavelength of 355nm is small, so it can be laser stripped, and it has excellent solvent solubility for GBL and cyclohexanone, so it can be solvent stripped using various solvents.

[0310] As described above, the polyimide resin of the present invention is preferably used as a temporary fixing material, and the temporary fixing material composition containing the polyimide resin has the above-mentioned excellent properties.

Claims

1. A polyimide resin comprising a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, The structural unit A contains a structural unit A1 derived from a compound represented by the following formula (a1), The structural unit B contains a structural unit B1 derived from a compound represented by the following formula (b1), In the formula, Z is a group represented by the following formula (1) or a group represented by the following formula (2), and X 1 and X 2 Each independently represents -O-, -C(CH3)2-, -C(CF3)2-, In formula (2), R 1 and R 2 Each is independently a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms.

2. The polyimide resin according to claim 1, wherein The ratio of the structural unit A1 in the structural unit A is 30 to 100 mol %.

3. The polyimide resin according to claim 1 or 2, wherein The ratio of the structural unit B1 in the structural unit B is 30 to 100 mol %.

4. The polyimide resin according to any one of claims 1 to 3, wherein The structural unit A1 contains at least one selected from the group consisting of a structural unit A11 derived from a compound represented by the following formula (a11) and a structural unit A12 derived from a compound represented by the following formula (a12), 5. The polyimide resin according to any one of claims 1 to 4, wherein The structural unit B1 contains a structural unit B11 derived from a compound represented by the following formula (b11), 6. The polyimide resin according to any one of claims 1 to 5, wherein The structural unit B further contains a structural unit B2 derived from a compound represented by the following formula (b2), In the formula, X 3 and X 4 Each independently represents -O-, -COO-, or -OCO-, and n is an integer of 2 to 10.

7. The polyimide resin according to any one of claims 1 to 6, comprising a structural unit represented by the following general formula (3): Where, L 1 and L 2 Each independently represents a monovalent aliphatic hydrocarbon having 1 to 5 carbon atoms or a monovalent aromatic group having 6 to 10 carbon atoms; and m represents an integer of 1 to 200. 8 . A polyimide varnish comprising the polyimide resin according to claim 1 and an organic solvent. 9 . A polyimide film comprising the polyimide resin according to claim 1 . 10 . A temporary fixing material composition comprising the polyimide resin according to claim 1 .

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