Polyamic acid resin composition and applications thereof

Abstract

To provide a polyamic acid resin composition that can form a resin film removable with an alkaline solution and is highly suitable for application to multilayer wiring substrates.SOLUTION: A polyamic acid resin composition of the present invention includes (a) a polyamic acid resin, (b) an ester compound, (c) a free radical scavenger, (d) a slip agent, and (e) a solvent. A resin film formed from the composition can be removed by an alkaline solution.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamic acid resin composition, which can be used as a support layer in high-temperature lamination presses and has the function of isolating and protecting the underlying copper foil circuit board, and which can be removed with an alkaline solution after the high-temperature lamination press process is completed. [Background technology]

[0002] In recent years, advances in semiconductors and electronic components have led to the development of smaller, lighter, more powerful, and more versatile electronic devices. This has led to a gradual increase in density of printed wiring boards, with the trend toward surface mounting of components. Currently, many technologies are being used to fabricate printed wiring boards with multilayer wiring structures, increasing the space available for internal wiring layout. Multilayer wiring boards are fabricated by repeatedly stacking and pressing laminated structures made of copper foil or other applicable conductive material and prepreg (PP, prepreg) or other applicable dielectric material onto a core material, thereby increasing the internal layout space of the wiring board. An electroplating process is then used to fill the through-holes and blind vias of each laminate structure with conductive material, thereby connecting each layer.

[0003] Polyimide resins have excellent heat resistance and mechanical properties, making them widely used in a variety of fields, particularly in the electronics industry. To prevent oxidation of metal wiring and corrosion from acidic and alkaline chemicals during the manufacturing process of printed wiring boards, protective films or resin coatings, primarily composed of polyimide, epoxy resin, or acrylic resin, are used to protect and support the wiring board during the high-temperature lamination press process. In recent years, the development of multilayer wiring boards has led to the adoption of a method for embedding electronic components in grooves on the multilayer wiring board to reduce the overall thickness of the board. Grooves are typically formed on multilayer wiring boards by removing portions of the laminate structure using processing methods such as laser drilling or CNC drilling. However, resin residue remains on the surface of the grooves. Therefore, desmearing (using sulfuric acid, plasma, chromic acid, or potassium permanganate) and various alkaline degreasing agents are used to remove the resin residue from the wiring board in the grooves. However, when general polyimide protective films and resin coatings undergo the high-temperature lamination press process, the chemical resistance of the resin increases and the resin reacts with other laminated thermosetting resins. This makes it impossible to completely remove the resin using the above-mentioned desmearing or alkaline degreasing agents, and it will affect subsequent metal surface treatments (e.g., black oxide, lead-free tin spraying, electroless nickel / immersion gold, nickel-gold plating, etc.). Summary of the Invention [Problem to be solved by the invention]

[0004] In view of this, an object of the present invention is to provide a polyamic acid resin composition which is capable of forming a resin film that can be removed with an alkaline solution and is highly suitable for application to multilayer wiring boards. [Means for solving the problem]

[0005] Based on the above object, the present invention provides the following polyamic acid resin composition and resin film.

[0006] Item 1. A polyamic acid resin composition, comprising: (a) a polyamic acid resin having a content of 40% by weight to 95% by weight based on the total solid content of the polyamic acid resin composition, the polyamic acid resin containing a structural unit represented by general formula (I); [ka] (b) an ester compound containing a compound represented by general formula (II), the content of which is 3% by weight to 50% by weight based on the total solid content of the polyamic acid resin composition; [ka] (c) a free radical scavenger whose content is 0.1% by weight to 15% by weight based on the total solid content of the polyamic acid resin composition; (d) a slip agent whose content is 0.1% by weight to 15% by weight based on the total solid content of the polyamic acid resin composition; (e) a solvent; wherein A is a tetravalent organic group containing an aliphatic ring group or an aromatic ring group, B is a divalent organic group containing an aromatic ring group, X and Z are each independently a divalent organic group containing an aliphatic ring group or an aromatic ring group, Y is a divalent organic group derived from a diol, and R 1 and R 2 are each independently an alkyl group or a hydroxyalkyl group, m is a positive integer, and p is an integer of 0 to 10.

[0007] Item 2. In the polyamic acid resin composition according to Item 1, A is a tetravalent organic group derived from a dianhydride containing an aliphatic ring group or an aromatic ring group.

[0008] Item 3. In the polyamic acid resin composition according to Item 1, B is a divalent organic group derived from a diamine containing an aromatic ring group.

[0009] Item 4: In the polyamic acid resin composition according to Item 1, X and Z are each independently a divalent organic group derived from a dicarboxylic acid containing an aliphatic ring group or an aromatic ring group.

[0010] Item 5. In the polyamic acid resin composition according to Item 4, X and Z are, respectively, phthalic acid, isophthalic acid, terephthalic acid, 2,6-dicarboxytoluene, 4-methylphthalic acid, biphenyl-4,4'-dicarboxylic acid, 1,1'-biphenyl-3,3'-dicarboxylic acid, 1,1'-biphenyl-3,4-dicarboxylic acid, 1,1'-biphenyl-3,4'-dicarboxylic acid, 1,1'-biphenyl-3,5-dicarboxylic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 4-(carboxymethyl)cyclohexanecarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0011] Item 6: In the polyamic acid resin composition according to Item 1, Y is a linear or branched alkylene group having 1 to 10 carbon atoms.

[0012] Item 7. In the polyamic acid resin composition according to Item 1, R 1 and R 2 are each independently a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms or a linear or branched alkyl group having 1 to 10 carbon atoms.

[0013] Item 8. The polyamic acid resin composition according to Item 6, wherein the compound represented by general formula (II) is [ka] is.

[0014] Item 9. In the polyamic acid resin composition according to Item 1, X and Z are each independently a phenylene group.

[0015] Item 10. A resin film formed from the polyamic acid resin composition described in claim 1.

[0016] According to the present invention, there is provided a polyamic acid resin composition capable of forming a resin film that can be removed with an alkaline solution. DETAILED DESCRIPTION OF THE INVENTION

[0017] The polyamic acid resin composition of the present invention comprises (a) a polyamic acid resin, (b) an ester compound, (c) a free radical scavenger, (d) a slip agent, and (e) a solvent.

[0018] The polyamic acid resin contains a structural unit represented by general formula (I). [ka]

[0019] In general formula (I), A is a tetravalent organic group containing an aliphatic ring group or an aromatic ring group, B is a divalent organic group containing an aromatic ring group, and m is a positive integer (e.g., 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100).

[0020] When general formula (I) contains a plurality of As, the As may be the same or different. A may be a tetravalent organic group derived from a dianhydride containing an aliphatic ring group or an aromatic ring group. Specific examples of the dianhydride include pyromellitic anhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic anhydride (ODPA), bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxylic anhydride), 1,4-bis(3,4-dicarboxyphenyl)propane dianhydride, ... Bis(phenoxy)benzene dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA), 4,4-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), p-phenylene bis(trimellitate anhydride) (TAHQ), ethylene glycol bis(trimellitic anhydride) (TMEG), propylene glycol bis(trimellitic anhydride) (TMPG), butanediol 2-Methyl-1,3-propanediol bis(trimellitic anhydride), dipropylene glycol bis(trimellitic anhydride), 2-methyl-2,4-pentylene glycol bis(trimellitic anhydride), diethylene glycol bis(trimellitic anhydride), tetraethylene glycol bis(trimellitic anhydride), hexaethylene glycol bis(trimellitic anhydride), neopentyl glycol bis(trimellitic anhydride), hydroquinone bis(2 -hydroxyethyl) ether bis(trimellitic anhydride), 2-phenyl-5-(2,4-hydroquinone)-1,4-hydroquinone bis(trimellitic anhydride), 2,3-dicyanohydroquinone cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 1,2,4,5-cyclopentane tetracarboxylic dianhydride (HPMDA), bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2) Examples include, but are not limited to, oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (COeDA), bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxy-cyclopentylacetic dianhydride, bicyclo[2.2.1]heptane-2,3,5-tricarboxy-6-acetic dianhydride, decahydro-1,4,5,8-dimethylnaphthalene-2,3,6,7-tetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride (CBDA), and 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride (HBPDA). These dianhydrides may be used alone or in combination.

[0021] When general formula (I) contains multiple Bs, the Bs may be the same or different. B may be a divalent organic group derived from a diamine containing an aromatic ring group. Examples of the diamine include m-phenylenediamine, p-phenylenediamine (pPDA), diaminodiphenyl ether (ODA), p-methylenedianiline (MDA), m-methylenedianiline, bisaminophenoxybenzene, bisaminophenoxybenzene, bis(4-aminophenyl)sulfone (4,4'-DDS), bis(3-aminophenyl)sulfone (3,3'-DDS), bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS), 9,9-bis(4-aminophenyl)fluorene, 2,2'-dimethylbenzidine (m-tolidine), 1,3-bis(3-aminophenoxy)benzene (TPE-M), 1,3-bis(4- (aminophenoxy)benzene (TPE-R), 1,4-bis(3-aminophenoxy)benzene (143BAPB), 1,4-bis(4-aminophenoxy)benzene (TPE-Q), 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), bis(4-aminophenyl)terephthalate (BPTP), 3,3'-dihydroxybenzidine (HAB), 5,5'-methylenebis(2-aminobenzoic acid) (MBAA), 5-amino-2-(p-aminophenyl)benzoxazole (5ABO), 6-amino-2-(p-aminophenyl)benzoxazole (6ABO), 9,9-bis(4-amino-3-fluorophenyl)fluorene , 2-(trifluoromethyl)benzene-1,4-diamine, 2,3-bis(trifluoromethyl)-1,4-benzenediamine, 2,6-bis(trifluoromethyl)-1,4-benzenediamine, 2,5-bis(trifluoromethyl)-1,4-benzenediamine, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP), 2,2'-bis(trifluoromethyl)benzidine (TFMB), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6-FODA), 3,3'-bis(trifluoromethyl)benzidine, 2,2'-bis-trifluoromethoxy-biphenyl-4,4'-diamine, 3,3'-bis-trifluoromethoxy-biphenyl-4,4'-Diamine, 3,3''-bis(trifluoromethyl)- [1,1':4',1''-terphenyl]-4,4''-diamine, 2,2''-bis(trifluoromethyl)- [1,1':4',1''-terphenyl]-4,4''-diamine, 2-fluorobenzene-1,4-diamine, 2,5-difluorobenzene-1,4-diamine, 2,4,5,6-tetrafluorobenzene-1,3-diamine, 4,4'-diaminooctafluorobiphenyl, 4,4'-diamino-2,2'-difluorobiphenyl, 2,2',5,5'-tetrafluoro- Examples of diamines include, but are not limited to, [1,1'-biphenyl]-4,4'-diamine, 4-(4-amino-2,6-difluorophenyl)-3,5-difluorobenzeneamine, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, and 2,2-bis(4-aminophenyl)hexafluoropropane. These diamines may be used alone or in combination of two or more.

[0022] From the viewpoint of providing good lamination press supportability and alkali removability, the content of the polyamic acid resin is 40 wt% to 95 wt%, preferably 50 wt% to 90 wt%, based on the total solid content of the polyamic acid resin composition. In some embodiments, the content of the polyamic acid resin is 51 wt% to 81 wt% based on the total solid content of the polyamic acid resin composition.

[0023] In the present invention, the ester compound includes a compound represented by general formula (II). [ka]

[0024] In the present invention, X and Z are each independently a divalent organic group containing an aliphatic ring group or an aromatic ring group, Y is a divalent organic group derived from a diol, and p is an integer of 0 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9).

[0025] When general formula (II) contains multiple Xs, the Xs may be the same or different. X may be a divalent organic group derived from a dicarboxylic acid containing an aliphatic or aromatic ring group. Examples of the dicarboxylic acid include, but are not limited to, phthalic acid, isophthalic acid, terephthalic acid, 2,6-dicarboxytoluene, 4-methylphthalic acid, biphenyl-4,4'-dicarboxylic acid, 1,1'-biphenyl-3,3'-dicarboxylic acid, 1,1'-biphenyl-3,4-dicarboxylic acid, 1,1'-biphenyl-3,4'-dicarboxylic acid, 1,1'-biphenyl-3,5-dicarboxylic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 4-(carboxymethyl)cyclohexanecarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. In some embodiments, X is a phenylene group.

[0026] When general formula (II) contains a plurality of Y's, the Y's may be the same or different. Y's may be a linear or branched alkylene group having 1 to 10 carbon atoms (e.g., 2, 3, or 4).

[0027] Illustrative examples of the compound represented by the general formula (II) are: [ka] Including, but not limited to:

[0028] In general formula (II), Z may be a divalent organic group derived from a dicarboxylic acid containing an aliphatic or aromatic ring group. In some embodiments, Z is a phenylene group.

[0029] In general formula (II), R 1 and R 2 may be the same or different. 1 and R 2are each independently an alkyl group or a hydroxyalkyl group, for example, a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., 2, 3, 4), or a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms (e.g., 2, 3, 4). In some embodiments, R 1 and R 2 are each independently a hydroxyethyl group. In some embodiments, R 1 and R 2 are each independently a methyl group.

[0030] To provide good alkali-removability, the content of the ester compound is 3 to 50 wt %, preferably 5 to 40 wt %, based on the total solid content of the polyamic acid resin composition. In some embodiments, the content of the ester compound is 10 to 35 wt %, based on the total solid content of the polyamic acid resin composition.

[0031] In the present invention, examples of the free radical scavenger include, but are not limited to, a free radical polymerization inhibitor and a light stabilizer. Examples of the free radical polymerization inhibitor include, but are not limited to, hydroquinone, toluhydroquinone, 4-methoxyphenol, 2,3,5-trimethylhydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, p-tert-butylhydroquinone, dibutylhydroxytoluene, p-benzoquinone, tert-butyl-1,4-benzoquinone, phenothiazine, and 2,2,6,6-tetramethylpiperidine 1-oxyl. Illustrative examples of light stabilizers include, but are not limited to, Eversorb 60, Eversorb 61, Eversorb 90, Eversorb 91FD, Eversorb 93, Eversorb 94FD, Eversorb 95, Eversorb 765, CHISORB 292, CHISORB 523, CHISORB 519, CHISORB 622LD, CHISORB 770, CHISORB 944, CHISORB 945, CHISORB 2959, and CHISORB 5144. These free radical scavengers may be used alone or in combination of any two or more.

[0032] To suppress reaction with other thermosetting resins, the content of the free radical scavenger is 0.1 to 15 wt %, preferably 0.5 to 10 wt %, based on the total solid content of the polyamic acid resin composition. In some embodiments, the content of the free radical scavenger is 3 to 8 wt % based on the total solid content of the polyamic acid resin composition.

[0033] In the present invention, examples of slip agents include, but are not limited to, acrylic silicone slip agents, such as SAC-342, SACT 3050D, SACN 3100D, SAC 3400D, SAC-3010D, SAC-3025D, SAC-3050D, SAC-3100D, SAC-3800, SAC-3000A, SAC-3098, SAC-3208D, SAC-3150D, SAC-3101D, SAC-30152D, SAC 35154D, SAC 3806E, S10191, SF-OH7C, SF-OH10B, SF-OHACR7C (manufactured by Anfeng Industrial Co., Ltd.), and Optool DAC-100 (trade name, manufactured by Daikin Industries, Ltd.). The slip agents may be used alone or in combination of two or more.

[0034] To prevent adhesion with other resins, the content of the slip agent is 0.1 to 15% by weight, preferably 0.5 to 10% by weight, based on the total solid content of the polyamic acid resin composition. In some embodiments, the content of the slip agent is 2 to 7% by weight based on the total solid content of the polyamic acid resin composition.

[0035] In the present invention, any solvent that can dissolve the polyamic acid resin can be used, and examples of such solvents include, but are not limited to, aprotic solvents such as N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, dimethyl sulfoxide, and dimethylimidazolidinone.

[0036] The polyamic acid resin composition of the present invention may be mixed with various additives, such as other solvents, various thixotropic agents, antifoaming agents, leveling agents, coupling agents, antioxidants, antiaging agents, ultraviolet absorbers, precipitation inhibitors, rheology control agents, and flame retardants, as needed.

[0037] In the present invention, the polyamic acid resin composition is obtained by mixing and stirring a polyamic acid resin solution with an ester compound, a free radical scavenger, and a slip agent at 30°C to 80°C (a solvent may be added as needed). In the present invention, the polyamic acid resin is obtained by polymerizing a dianhydride monomer and a diamine monomer. Specifically, the polyamic acid resin is obtained by polymerizing at least two dianhydride monomers and at least two diamine monomers. An exemplary polymerization method involves dissolving the dianhydride monomers and the diamine monomers in a solvent, and then mixing and reacting the dissolved dianhydride monomers and diamine monomers to obtain the polyamic acid resin solution. According to one embodiment of the present invention, the solvent content is 78 wt % of the total weight of the polyamic acid resin solution, i.e., a polyamic acid resin solution with a solids content of 22 wt % is formed.

[0038] The present invention also provides a resin film formed from the aforementioned polyamic acid resin composition. According to one embodiment of the present invention, a method for producing the resin film includes forming a film from the aforementioned polyamic acid resin composition and drying the film.

[0039] In order to clarify the effects of the present invention, the inventors have completed examples and comparative examples in the manner described below. The following examples and comparative examples are intended to further explain the present invention, but the examples and comparative examples do not limit the scope of the present invention. Any modifications or changes made by those familiar with the technical field of the present invention that do not deviate from the gist of the present invention are included in the scope of the present invention.

[0040] The abbreviations of the components used in the examples have the following meanings:

[0041] The polyamic acid resin solution-related components are as follows:

[0042] PMDA: Pyromellitic anhydride ODPA: 4,4'-oxydiphthalic anhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride TAHQ: p-phenylenebis(trimellitic anhydride) COeDA: Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride CBDA: butane-1,2,3,4-tetracarboxylic dianhydride TFMB: 2,2'-bis(trifluoromethyl)benzidine 6-FODA: 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether BPTP: Bis(4-aminophenyl) terephthalate pPDA: p-phenylenediamine 3,3'-DDS: Bis(3-aminophenyl) sulfone HAB: 3,3'-dihydroxybenzidine ODA: Diaminodiphenyl ether DMAc: N,N-dimethylacetamide

[0043] The following components are illustrative of ester compounds:

[0044] B1: Dimethyl isophthalate [ka] B2: 1,2-bis[p-(2-hydroxyethoxycarbonyl)benzoyloxy]ethane (CAS No. 2144-69-6) [ka] B3: Ethylene terephthalate linear trimer (CAS No. 16033-73-1) [ka]

[0045] The following ingredients are illustrative of free radical scavengers:

[0046] C1: p-benzoquinone C2: CHISORB292

[0047] The following ingredients are illustrative of slip agents:

[0048] D1:SAC-342

[0049] [Example 1] 16.01g (0.05 mole) of 2,2'-bis(trifluoromethyl)benzidine (TFMB), 17.42g (0.05 mole) of bis(4-aminophenyl)terephthalate (BPTP), and 212.18g of N,N-dimethylacetamide (DMAc) were placed in a three-neck flask. After stirring at 30°C until completely dissolved, 10.91g (0.05 mole) of pyromellitic anhydride (PMDA) and 15.51g (0.05 mole) of 4,4'-oxydiphthalic anhydride (ODPA) were added, and the mixture was allowed to react for 24 hours at 25°C with continued stirring to obtain a polyamic acid resin solution with a solids content of 22% by weight.

[0050] To the above polyamic acid resin solution containing 59.85 g of polyamic acid resin solids, 23.02 g of dimethyl isophthalate, 7.37 g of p-benzoquinone, and 1.84 g of SAC-342 were added and stirred for 2 hours at 30°C to obtain a polyamic acid resin composition. In this composition, the total solid weight of the polyamic acid resin, ester compound, free radical scavenger, and slip agent (i.e., the total solids of the polyamic acid resin composition) is defined as 100 wt%, and the contents of the polyamic acid resin, ester compound, free radical scavenger, and slip agent are 65 wt%, 25 wt%, 8 wt%, and 2 wt%, respectively.

[0051] [Examples 2 to 9 and Comparative Examples 1 to 6] Production of polyamic acid resin composition

[0052] The polyamic acid resin solutions used in Examples 2 to 9 and Comparative Examples 1 to 6 can be obtained according to the method of Example 1 using the components and amounts listed in Table 1. Subsequently, an ester compound, a free radical scavenger, and a slip agent were added to the polyamic acid resin solution according to the amounts listed in Table 1, to obtain the polyamic acid resin compositions of Examples 2 to 9 and Comparative Examples 1 to 6.

[0053] Evaluation method

[0054] <Chemical resistance> The polyamic acid resin composition was applied to the surface of a copper foil substrate by screen printing and baked to dryness at 120°C to form a film with a thickness of 25 µm. The film was immersed in a 4 wt% aqueous solution of sodium hydroxide at 50°C for 1 minute, and the presence or absence of film thickness reduction was measured. No decrease in film thickness: 〇 Film thickness decreased: ×

[0055] <Heat resistance during high-temperature lamination press> The polyamic acid resin composition was applied to the surface of a copper foil substrate by screen printing and baked to dry at 120°C to form a 25 μm-thick resin film. The film was then covered with PP (prepreg, semi-cured film) and placed in a press to carry out a high-temperature lamination press process at 230°C for 5 hours. No bulges or bubbles at the film position: 〇 Bulges or bubbles in the film: ×

[0056] <Possibility of film peeling after high-temperature lamination press> The PP (prepreg, semi-cured film) on top of the resin film after the above-mentioned high-temperature lamination press was peeled off and removed to expose the film, thereby testing the peelability. PP can be peeled off from the film and removed: Yes PP cannot be peeled off from the film: ×

[0057] <Possibility of removing coating after high-temperature lamination press> After peeling off the PP (prepreg), the exposed coating was immersed in a 6 wt % sodium hydroxide aqueous solution at 50°C for 20 minutes to observe whether the coating was completely removed. The film was completely removed: Yes The thickness of the film decreased: △ No reduction in film: ×

[0058] [Table 1]

[0059] As shown in Table 1, the polyamic acid resin composition of the present invention was excellent in all aspects: chemical resistance, heat resistance in high-temperature lamination press, film peelability after high-temperature lamination press, and film removability after lamination press. In contrast, Comparative Example 1, in which no (b) ester compound was added, was unfavorable to dissolution after sodium hydroxide hydrolysis, and the film could not be removed after lamination press. Comparative Example 2, in which an excessive amount of (b) ester compound was added, exhibited reduced chemical resistance (particularly alkali resistance) of the film before lamination press. Comparative Example 3 had an insufficient (a) polyamic acid resin content and an excessive amount of free radical scavenger, resulting in swelling and bubble formation in the film after high-temperature lamination press, and reduced heat resistance in high-temperature lamination press. Comparative Example 4 had an excessive (a) polyamic acid resin content, while the (b) ester compound content was insufficient to dissolve the film after lamination press, resulting in the film being unable to be removed, as in Comparative Example 1. In Comparative Example 5, (c) a free radical scavenger and (d) a slip agent were not added, and the coating and PP (prepreg) adhered tightly after lamination pressing, making them difficult to peel off and disadvantageous for subsequent coating removal. In Comparative Example 6, (d) an excessive amount of slip agent was added, causing the coating to swell and form bubbles after high-temperature lamination pressing. The slip agent reduced the adhesion between the coating and PP (prepreg) interface, and the heat resistance of the coating during lamination pressing was reduced.

[0060] To summarize the above, the polyamic acid resin composition of the present invention was excellent in all of chemical resistance, heat resistance in high-temperature lamination pressing, film peelability after high-temperature lamination pressing, and film removability after lamination pressing.

[0061] The above description is based on a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. All changes and modifications that have simple equivalent effects based on the claims and the contents of the specification of the present invention are included within the patentable scope of the present invention.

Claims

1. A polyamic acid resin composition, (a) a polyamic acid resin having a content of 40% by weight to 95% by weight based on the total solid content of the polyamic acid resin composition, the polyamic acid resin containing a structural unit represented by general formula (I); 【Chemistry 1】 (b) an ester compound containing a compound represented by general formula (II), the content of which is 3% by weight to 50% by weight based on the total solid content of the polyamic acid resin composition; 【Chemistry 2】 (c) a free radical scavenger in an amount of 0.1% by weight to 15% by weight based on the total solid content of the polyamic acid resin composition; (d) a slip agent in an amount of 0.1% by weight to 15% by weight based on the total solid content of the polyamic acid resin composition; (e) a solvent; and wherein A is a tetravalent organic group containing an aliphatic ring group or an aromatic ring group, B is a divalent organic group containing an aromatic ring group, X and Z are each independently a divalent organic group containing an aliphatic ring group or an aromatic ring group, Y is a divalent organic group derived from a diol, and R 1 and R 2 are each independently an alkyl group or a hydroxyalkyl group, m is a positive integer, and p is an integer of 0 to 10.

2. 2. The polyamic acid resin composition according to claim 1, wherein A is a tetravalent organic group derived from a dianhydride containing an aliphatic cyclic group or an aromatic cyclic group.

3. 2. The polyamic acid resin composition according to claim 1, wherein B is a divalent organic group derived from a diamine containing an aromatic ring group.

4. 2. The polyamic acid resin composition according to claim 1, wherein X and Z are each independently a divalent organic group derived from a dicarboxylic acid containing an aliphatic ring group or an aromatic ring group.

5. 5. The polyamic acid resin composition according to claim 4, wherein X and Z are each independently phthalic acid, isophthalic acid, terephthalic acid, 2,6-dicarboxytoluene, 4-methylphthalic acid, biphenyl-4,4'-dicarboxylic acid, 1,1'-biphenyl-3,3'-dicarboxylic acid, 1,1'-biphenyl-3,4-dicarboxylic acid, 1,1'-biphenyl-3,4'-dicarboxylic acid, 1,1'-biphenyl-3,5-dicarboxylic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 4-(carboxymethyl)cyclohexanecarboxylic acid, 1,3-cyclohexanedicarboxylic acid, or 1,4-cyclohexanedicarboxylic acid.

6. 2. The polyamic acid resin composition according to claim 1, wherein Y is a linear or branched alkylene group having 1 to 10 carbon atoms.

7. R 1 and R 2 and each independently represent a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms or a linear or branched alkyl group having 1 to 10 carbon atoms.

8. The compound represented by the general formula (II) 【Transformation 3】 The polyamic acid resin composition according to claim 6, wherein

9. 2. The polyamic acid resin composition according to claim 1, wherein X and Z each independently represent a phenylene group.

10. A resin film formed from the polyamic acid resin composition according to claim 1.

Images