JP2020164657A - Production method of polybenzoxazole and photosensitive resin composition - Google Patents

Abstract

To provide a production method of polybenzoxazole, by which, when N-methylpyrrolidone is used as a reaction solvent for a polybenzoxazole precursor, polybenzoxazole having higher purity can be obtained with a reduced amount of the N-methylpyrrolidone remaining in the obtained polybenzoxazole.SOLUTION: The production method includes: a step of synthesizing polybenzoxazole by the reaction of a polybenzoxazole precursor in N-methylpyrrolidone; a step of separating the synthesized polybenzoxazole; a step of mixing and dissolving the separated polybenzoxazole with a good solvent other than the N-methylpyrrolidone and capable of dissolving the polybenzoxazole, so as to clean the polybenzoxazole; and a step of separating a separation substance containing the polybenzoxazole from the good solvent.SELECTED DRAWING: None

Description

The present invention relates to a method for producing polybenzoxazole and a photosensitive resin composition.

As a method for synthesizing polybenzoxazole, N-methylpyrrolidone is used as a reaction solvent to react the polybenzoxazole precursor, and then the reaction product precipitated by the reprecipitation method is separated, and the polybenzoxazole is obtained through a drying step. A method for obtaining the substance is known (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-265520

In the conventional method for synthesizing polybenzoxazole when N-methylpyrrolidone is used as a reaction solvent, N-methylpyrrolidone used as a reaction solvent remains in the obtained polybenzoxazole without being removed. Was difficult to avoid.

The present invention has been made in view of the above-mentioned problems, and when N-methylpyrrolidone is used as a reaction solvent for a polybenzoxazole precursor, the amount of N-methylpyrrolidone remaining in the obtained polybenzoxazole is reduced. An object of the present invention is to provide a method for producing a polybenzoxazole, which can obtain a polybenzoxazole having a higher purity.

According to the present invention, a step of synthesizing polybenzoxazole by the reaction of a polybenzoxazole precursor in an organic solvent composed of N-methylpyrrolidone, and a step of separating the polybenzoxazole synthesized from the organic solvent. The step of washing the polybenzoxazole by mixing the separated polybenzoxazole with a good solvent capable of dissolving the polybenzoxazole other than the organic solvent and dissolving the polybenzoxazole, and the polybenzo from the good solvent. A method for producing a polybenzoxazole is provided, which comprises a step of separating a isolate containing an oxazole.
Further, according to the present invention, there is provided a photosensitive resin composition containing the polybenzoxazole produced by the above-mentioned method for producing polybenzoxazole, a photosensitive agent, and a solvent.

According to the present invention, when N-methylpyrrolidone is used as a reaction solvent for a polybenzoxazole precursor, the amount of N-methylpyrrolidone remaining in the obtained polybenzoxazole can be reduced.

Hereinafter, embodiments of the present invention will be described in detail. In the present specification, the notation "a to b" in the description of the numerical range indicates that it is a or more and b or less unless otherwise specified.

The method for producing polybenzoxazole according to the embodiment includes a step of synthesizing polybenzoxazole, a step of separating polybenzoxazole from an organic solvent, a step of washing polybenzoxazole, and a step of separating a isolate containing polybenzoxazole. Including the process. The details of each step will be described below.

(Step of synthesizing polybenzoxazole)
In this step, polybenzoxazole is synthesized by the reaction of a polybenzoxazole precursor in an organic solvent consisting of N-methylpyrrolidone.
The method for synthesizing the polybenzoxazole precursor is not particularly limited, and examples thereof include a well-known synthesis method such as an acid chloride method in which a dicarboxylic acid dichloride and a bisaminophenol compound are reacted.
The reaction of the polybenzoxazole precursor can be carried out by thermal dehydration or catalytic dehydration ring closure reaction.

Examples of the polybenzoxazole precursor include a polyamide resin containing a structural unit represented by the following formula (PA1).

上記式（ＰＡ１）で表される構造単位を含むポリアミド樹脂は、例えば、１５０℃以上３８０℃以下の温度で、３０分間以上５０時間以下の条件で熱処理されることによって、脱水閉環し、ポリベンゾオキサゾール樹脂とすることができる。ここで、上記式（ＰＡ１）の構造単位は、脱水閉環によって、下記式（ＰＢＯ１）で示される構造単位となる。

The polyamide resin containing the structural unit represented by the above formula (PA1) is dehydrated and ring-closed by heat treatment at a temperature of 150 ° C. or higher and 380 ° C. or lower under the conditions of 30 minutes or longer and 50 hours or lower, and polybenzo. It can be an oxazole resin. Here, the structural unit of the above formula (PA1) becomes a structural unit represented by the following formula (PBO1) by dehydration ring closure.

(Step of separating polybenzoxazole from organic solvent)
In this step, polybenzoxazole in the organic solvent is separated. Examples of the method for separating polybenzoxazole include a reprecipitation method. Examples of the poor solvent used in the reprecipitation method include a mixed solution of isopropyl alcohol and pure water.

(Step of cleaning polybenzoxazole)
In this step, the polybenzoxazole is washed by mixing and dissolving the separated polybenzoxazole in a good solvent capable of dissolving the polybenzoxazole other than the above-mentioned organic solvent. By washing the polybenzoxazole with a good solvent that does not contain N-methylpyrrolidone, the N-methylpyrrolidone mixed in the polybenzoxazole is diluted, and the amount of N-methylpyrrolidone contained per unit volume of the polybenzoxazole. Is greatly reduced.
Examples of the good solvent include γ-butyrolactone and an amide-based solvent, and a solvent containing at least one of these can be used. The amide-based solvent is represented by, for example, the following chemical formula (1).

（化学式（１）中、Ｒ^１は炭素数１〜１８の有機基であり、Ｒ^２およびＲ^３は、下記（ｉ）または（ｉｉ）を満たし、Ｒ^４は水素またはメチルであり、ｎは０〜３の整数であり、ｍは０または１である。（ｉ）Ｒ^２およびＲ^３は、それぞれ独立に水素または炭素数１〜６の有機基である。（ｉｉ）Ｒ^２およびＲ^３は、互いに結合して環構造を形成する。）
より具体的には、アミド系溶媒として、３−メトキシ−Ｎ，Ｎ−ジメチルプロパンアミドなどが挙げられる。

(In the chemical formula (1), R ¹ is an organic group having 1 to 18 carbon atoms, R ² and R ³ satisfy the following (i) or (ii), R ⁴ is hydrogen or methyl, and n is. It is an integer of 0 to 3, and m is 0 or 1. (i) R ² and R ³ are independently hydrogen or organic groups having 1 to 6 carbon atoms. (Ii) R ² and R ^{3 respectively.} Combine with each other to form a ring structure.)
More specifically, examples of the amide-based solvent include 3-methoxy-N and N-dimethylpropanamide.

(Step of separating the isolate containing polybenzoxazole)
In this step, a isolate containing polybenzoxazole is separated from the above-mentioned good solvent. Examples of the method for separating the separated product containing polybenzoxazole include a reprecipitation method. Examples of the poor solvent used in the reprecipitation method include a mixed solution of isopropyl alcohol and pure water. Before carrying out the reprecipitation method, in other words, it is preferable to reduce the particle size of the polybenzoxazole contained in the good solvent before mixing the polybenzoxazole with the good solvent. Examples of the method for reducing the particle size of the polybenzoxazole contained in the good solvent include a method of crushing the polybenzoxazole contained in the good solvent using a homogenizer. According to this, N-methylpyrrolidone can be easily removed from the isolate containing polybenzoxazole in the above-mentioned good solvent, and the amount of N-methylpyrrolidone in the isolate containing polybenzoxazole can be further reduced. it can.
The separated product precipitated by the reprecipitation method is taken out by a separating means such as a centrifuge.

According to the method for producing polybenzoxazole described above, the amount of N-methylpyrrolidone in the resulting isolate containing polybenzoxazole can be reduced. The residual amount of N-methylpyrrolidone contained in the separated product is preferably 1% by mass or less, more preferably 0.5% by mass or less, and most preferably 0.15% by mass (1500 ppm) with respect to the entire separated product. ) The following.

The step of re-washing the polybenzoxazole by re-mixing and dissolving the separated product obtained by the above-mentioned method for producing polybenzoxazole in the above-mentioned good solvent and the polybenzo rewashed from the good solvent. The step of separating the oxazole to obtain a rewashed isolate containing the polybenzoxazole may be further carried out. The step of obtaining the rewashed isolate is the same as the step of separating the isolate containing polybenzoxazole, and specific examples thereof include a method of separating the precipitate by a centrifuge by a reprecipitation method.

By going through the above-mentioned rewashing step and the step of obtaining the rewashing separation product, the amount of N-methylpyrrolidone in the separation product containing polybenzoxazole can be further reduced. The residual amount of N-methylpyrrolidone contained in the rewashed isolate is preferably 0.3% by mass or less, more preferably 0.02% by mass (200 ppm) or less, most preferably, based on the entire rewashed isolate. It is preferably 0.005% by mass (50 ppm) or less.

(Photosensitive resin composition)
The photosensitive resin composition according to the embodiment contains a polybenzoxazole (alkali-soluble resin) produced by the method for producing polybenzoxazole of the above-described embodiment, a photosensitizer and a solvent. Since the photosensitive resin composition of the present embodiment has a small residual amount of N-methylpyrrolidone and high purity, it is possible to improve the performance such as photosensitivity and film forming property required for the photosensitive resin composition.

(Polybenzoxazole)
The polybenzoxazole used in the present embodiment is produced by the above-mentioned method for producing polybenzoxazole, and is characterized in that the residual amount of N-methylpyrrolidone mixed in the polybenzoxazole is small.

(Photosensitive agent)
As the photosensitizer, a photoacid generator that generates an acid by absorbing light energy can be used.
Specific examples of the photoacid generator include a diazoquinone compound; a diallyl iodonium salt; a 2-nitrobenzyl ester compound; an N-iminosulfonate compound; an imide sulfonate compound; 2,6-bis (trichloromethyl) -1,3. 5-Triazine compound; dihydropyridine compound and the like can be mentioned. Among these, it is preferable to use a photosensitive diazoquinone compound. Thereby, the sensitivity of the photosensitive resin composition can be improved. Therefore, the accuracy of the pattern can be improved and the appearance can be improved. The photoacid generator may include one or more of the above specific examples.
When the photosensitive resin composition is of the positive type, a triarylsulfonium salt; an onium salt such as a sulfonium / borate salt may be used in combination as the photosensitive agent in addition to the above specific examples. Thereby, the sensitivity of the photosensitive resin composition can be further improved.

In each of the above diazoquinone compounds, Q is a structure represented by the following formula (a), the following formula (b) and the following formula (c), or a hydrogen atom. However, at least one of the Qs of each diazoquinone compound has a structure represented by the following formula (a), the following formula (b) and the following formula (c).
The Q of the diazoquinone compound preferably contains the following formula (a) or the following formula (b). Thereby, the transparency of the photosensitive resin composition can be improved. Therefore, the appearance of the photosensitive resin composition can be improved.

The lower limit of the content of the photosensitizer in the photosensitive resin composition is, for example, preferably 1 part by mass or more, and more preferably 3 parts by mass or more, when polybenzoxazole is 100 parts by mass. It is more preferably 5 parts by mass or more. As a result, the photosensitive resin composition can exhibit appropriate sensitivity.
Further, the upper limit of the content of the photosensitive agent in the photosensitive resin composition is, for example, preferably 30 parts by mass or less, and preferably 20 parts by mass or less, when polybenzoxazole is 100 parts by mass. More preferred. As a result, it is possible to prevent the photosensitive resin composition from being repelled by the material present on the surface of the substrate.

(solvent)
The solvent is preferably an organic solvent. Examples of the organic solvent include γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and methyl lactate. Examples thereof include ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate and methyl-3-methoxypropionate.

Only one type of solvent may be used, or two or more types may be used in combination.
The amount of the organic solvent (total amount when two or more kinds are used in combination) is 50 parts by mass to 1000 parts by mass, preferably 100 parts by mass to 500 parts by mass with respect to 100 parts by mass of polybenzoxazole. By using an organic solvent in the above range, it is possible to obtain a photosensitive resin composition having excellent handleability in which each component is sufficiently dissolved.

The photosensitive resin composition according to the present embodiment further contains additives such as an adhesion aid, a silane coupling agent, a thermal cross-linking agent, a surfactant, an antioxidant, a dissolution accelerator, a filler, and a sensitizer. You may.
The representative components will be described in detail below.

(Adhesion aid)
The photosensitive resin composition according to the present embodiment may further contain an adhesion aid. Specifically, a triazole compound or aminosilane can be used as the adhesion aid. This makes it possible to further increase the number of lone electron pairs derived from the nitrogen atom. Therefore, the inclusions other than the solvent of the photosensitive resin composition can be coordinated with respect to the metal atoms, and the adhesion can be further improved. As the adhesion aid, either a triazole compound or an aminosilane may be used, or a triazole compound and an aminosilane may be used in combination.
Specific examples of the triazole compound include 4-amino-1,2,4-triazole, 4H-1,2,4-triazole-3-amine, 4-amino-3,5-di-2-pyridyl-. 4H-1,2,4-triazole, 3-amino-5-methyl-4H-1,2,4-triazole, 4-methyl-4H-1,2,4-triazole-3-amine, 3,4- Diamino-4H-1,2,4-triazole, 3,5-diamino-4H-1,2,4-triazole, 1,2,4-triazole-3,4,5-triamine, 3-pyridyl-4H- 1,2,4-Triazole, 4H-1,2,4-Triazole-3-Carboxamide, 3,5-diamino-4-methyl-1,2,4-Triazole, 3-Pyridyl-4-methyl-1, Examples thereof include 1,2,4-triazole such as 2,4-triazole and 4-methyl-1,2,4-triazole-3-carboxamide. As the triazole compound, one or a combination of two or more of the above specific examples can be used.
Specific examples of the aminosilane include a condensate of cyclohexene-1,2-dicarboxylic acid anhydride and 3-aminopropyltriethoxysilane, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride and 3 Condensate of −aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (amino) Ethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl -3-Aminopropyltrimethoxysilane, N, N'bis [3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis- (3-triethoxysilylpropyl) ethylenediamine, N, N'-bis [ 3- (Methyldimethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (methyldiethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (dimethylmethoxysilyl) propyl] ethylenediamine, N- [3- (Methyldimethoxysilyl) propyl] -N'-[3- (trimethoxysilyl) propyl] ethylenediamine, N, N'-bis [3- (trimethoxysilyl) propyl] diaminopropane, N, N'- Examples thereof include bis [3- (trimethoxysilyl) propyl] diaminohexane and N, N'-bis [3- (trimethoxysilyl) propyl] diethylenetriamine. As the aminosilane, one or a combination of two or more of the above specific examples can be used.

The lower limit of the content of the adhesion aid in the photosensitive resin composition is, for example, preferably 0.1 part by mass or more, and 1.0 part by mass or more with respect to 100 parts by mass of polybenzoxazole. More preferably, it is more preferably 2.0 parts by mass or more, and further preferably 3.0 parts by mass or more. As a result, the triazole compound can be suitably coordinated with metal atoms such as Al and Cu, and the adhesion can be further improved.
The upper limit of the content of the adhesion aid in the photosensitive resin composition is, for example, preferably 10 parts by mass or less, and 7 parts by mass or less, based on 100 parts by mass of polybenzoxazole. More preferably, it is more preferably 5 parts by mass or less. As a result, the adhesion aid can be suitably dispersed in the photosensitive resin composition, and the adhesion can be improved.

(Silane coupling agent)
The photosensitive resin composition according to the present embodiment may further contain a silane coupling agent. Examples of the silane coupling agent include those other than the aminosilane exemplified as the adhesion aid.
Specific examples of the silane coupling agent having a structure different from that of the above-mentioned silane compound include vinyl silanes such as vinyl trimethoxysilane and vinyl triethoxysilane; 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Epoxysilanes such as glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane; p-styryltrimethoxysilane Styrylsilanes such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, methacrylsilanes such as 3-methacryloxypropyltriethoxysilane; 3-acryloxy Acrylic silanes such as propyltrimethoxysilane; isocyanurate silanes; alkylsilanes; ureidosilanes such as 3-ureidopropyltrialkoxysilanes; mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; 3- Examples thereof include isocyanate silanes such as isocyanate propyltriethoxysilane; titanium-based compounds; aluminum chelates; aluminum / zirconium-based compounds. As the silane coupling agent, one or more of the above specific examples can be blended.

(Thermal crosslinker)
The photosensitive resin composition according to the present embodiment may contain a thermal cross-linking agent capable of reacting with polybenzoxazole by heat. As a result, it is possible to improve the mechanical properties such as tensile elongation at break of the cured product obtained by post-baking the photosensitive resin composition. It is also convenient from the viewpoint of improving the sensitivity of the resin film formed by the photosensitive resin composition.
Specific examples of the thermal cross-linking agent include 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol (paraxylene glycol), 1,3,5-benzenetrimethanol, and the like. Methylol groups such as 4,4-biphenyldimethanol, 2,6-pyridinedimethanol, 2,6-bis (hydroxymethyl) -p-cresol, 4,4'-methylenebis (2,6-dialkoxymethylphenol) Compounds with; phenols such as fluorogluside; 1,4-bis (methoxymethyl) benzene, 1,3-bis (methoxymethyl) benzene, 4,4'-bis (methoxymethyl) biphenyl, 3,4'-bis Compounds having an alkoxymethyl group such as (methoxymethyl) biphenyl, 3,3'-bis (methoxymethyl) biphenyl, methyl 2,6-naphthalenedicarboxylate, 4,4'-methylenebis (2,6-dimethoxymethylphenol) Methylol melamine compounds typified by hexamethylol melamine, hexabutanol melamine, etc .; alkoxy melamine compounds such as hexamethoxy melamine; alkoxymethyl glycol uryl compounds such as tetramethoxymethyl glycol uryl; methylol benzoguanamine compounds, methylol such as dimethylol ethyleneurea Urea compounds; cyano compounds such as dicyanoaniline, dicyanophenol, cyanophenylsulfonic acid; isocyanate compounds such as 1,4-phenylenediisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; ethylene Epoxy group-containing compounds such as glycol diglycidyl ether, bisphenol A diglycidyl ether, triglycidyl isocyanurate, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene epoxy resin, biphenyl type epoxy resin, phenol novolac resin type epoxy resin Examples include maleimide compounds such as N, N'-1,3-phenylenedi maleimide and N, N'-methylenedimaleimide. As the thermal cross-linking agent, one or a combination of two or more of the above specific examples can be used.

The upper limit of the content of the heat-crosslinking agent in the photosensitive resin composition is, for example, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, based on 100 parts by mass of polybenzoxazole. , 12 parts by mass or less, more preferably 10 parts by mass or less. As a result, even when the thermal cross-linking agent has a solvating functional group such as a phenolic hydroxyl group, it is possible to suppress a decrease in chemical resistance after post-baking.
The lower limit of the content of the heat-crosslinking agent in the photosensitive resin composition is preferably, for example, 0.1 part by mass or more, and is preferably 1 part by mass or more, based on 100 parts by mass of polybenzoxazole. More preferably, it is more preferably 3 parts by mass or more, further preferably 5 parts by mass or more, and particularly preferably 8 parts by mass or more.

(Surfactant)
The photosensitive resin composition according to the present embodiment may further contain a surfactant.
Surfactants are not limited, and specifically, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, and polyoxyethylene. Polyoxyethylene aryl ethers such as nonylphenyl ethers; nonionic surfactants such as polyoxyethylene dilaurates and polyoxyethylene dialkyl esters such as polyoxyethylene dilaurates; Ftop EF301, Ftop EF303, Ftop EF352 (Made by Shin-Akita Kasei Co., Ltd.), Mega Fuck F171, Mega Fuck F172, Mega Fuck F173, Mega Fuck F177, Mega Fuck F444, Mega Fuck F470, Mega Fuck F471, Mega Fuck F475, Mega Fuck F482, Mega Fuck F477 (DIC) ), Florard FC-430, Florard FC-431, Novell FC4343, Novell FC4432 (manufactured by 3M Japan), Surfron S-381, Surfron S-382, Surfron S-383, Surfron S-393, Surfron SC-101, Fluorosurfactants commercially available under the names of Surflon SC-102, Surflon SC-103, Surflon SC-104, Surflon SC-105, Surflon SC-106, (manufactured by AGC Seimi Chemical Co., Ltd.); Organosiloxane co-weight Combined KP341 (manufactured by Shinetsu Chemical Industry Co., Ltd.); (meth) acrylic acid-based copolymer Polyflow No. 57, 95 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like.
As the surfactant, a silicone-based surfactant (for example, polyether-modified dimethylsiloxane) can also be preferably used. Specifically, as silicone-based surfactants, Toshiba Dow Corning's SH series, SD series and ST series, Big Chemie Japan's BYK series, Shin-Etsu Chemical Co., Ltd.'s KP series, and NOF Corporation's Disform ( Examples include the (registered trademark) series and the TSF series of Toshiba Silicone Co., Ltd.
Among these, it is preferable to use a fluorine-based surfactant having a perfluoroalkyl group. Among the above-mentioned specific examples, examples of the fluorine-based surfactant having a perfluoroalkyl group include Megafvck F171, Megafvck F173, Megafvck F444, Megafvck F470, Megafvck F471, Megafvck F475, Megafvck F482, and Megafvck. One or more selected from F477 (manufactured by DIC), Surflon S-381, Surfron S-383, Surfron S-393 (manufactured by AGC Seimi Chemical), Noveck FC4430 and Noveck FC4432 (manufactured by 3M Japan) Is preferably used.

(Antioxidant)
The photosensitive resin composition according to the present embodiment may further contain an antioxidant. As the antioxidant, one or more selected from a phenol-based antioxidant, a phosphorus-based antioxidant and a thioether-based antioxidant can be used. The antioxidant can suppress the oxidation of the resin film formed by the photosensitive resin composition.
Phenol-based antioxidants include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3). -T-Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} 2,4,8,10-tetraoxaspiro [5,5] undecane, octadecyl-3- (3,3) 5-di-t-butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5 -Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t -Butyl-4-ethylphenol, 2,6-diphenyl-4-octadesiloxyphenol, stearyl (3,5-di-t-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-t) -Butyl-4-hydroxybenzyl) phosphonate, thiodiethylene glycolbis [(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-t-butyl-m-cresol) , 2-octylthio-4,6-di (3,5-di-t-butyl-4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-t-butyl-6- Butylphenol), 2,-2'-methylenebis (4-ethyl-6-t-butylphenol), bis [3,3-bis (4-hydroxy-3-t-butylphenyl) butylacid] glycol ester, 4, 4'-Butylidenebis (6-t-butyl-m-cresol), 2,2'-etylidenebis (4,6-di-t-butylphenol), 2,2'-etylidenebis (4-s-butyl-6) -T-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, bis [2-t-butyl-4-methyl-6- (2-hydroxy-) 3-t-Butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-tri Su [(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane , 2-t-butyl-4-methyl-6- (2-acryloyloxy-3-t-butyl-5-methylbenzyl) phenol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl)- 2,4-8,10-Tetraoxaspiro [5,5] undecane-bis [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], triethyleneglycolbis [β-( 3-t-butyl-4-hydroxy-5-methylphenyl) propionate], 1,1'-bis (4-hydroxyphenyl) cyclohexane, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-Methylenebis (4-ethyl-6-t-butylphenol), 2,2'-Methylenebis (6- (1-methylcyclohexyl) -4-methylphenol), 4,4'-butylidenebis (3-methyl) -6-t-butylphenol), 3,9-bis (2- (3-t-butyl-4-hydroxy-5-methylphenylpropioniloxy) 1,1-dimethylethyl) -2,4,8,10- Tetraoxaspiro (5,5) undecane, 4,4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-bis (3,5-di-t-butyl-4-hydroxybenzyl) Sulfide, 4,4'-thiobis (6-t-butyl-2-methylphenol), 2,5-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butyl-6 -(3-t-Butyl-2-hydroxy-5-methylbenzyl) -4-methylphenylacrylate, 2,4-dimethyl-6- (1-methylcyclohexyl, styrenated phenol, 2,4-bis ((( Octylthio) methyl) -5-methylphenol, and the like.
Phosphorus antioxidants include bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenylphosphite), and tetrakis (2). , 4-di-t-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, bis- (2,6) -Dicumylphenyl) pentaerythritol diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite, tris (mixed monoand di-nonylphenylphosphite), bis (2, 4-di-t-Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methoxycarbonylethyl-phenyl) pentaerythritol diphosphite, bis (2,6-di-t) −Butyl-4-octadecyloxycarbonylethylphenyl) pentaerythritol diphosphite and the like.
Thioether-based antioxidants include dilauryl-3,3'-thiodipropionate and bis (2-methyl-4- (3-n-dodecyl) thiopropionyloxy) -5-t-butylphenyl) sulfide. , Distearyl-3,3'-thiodipropionate, pentaerythritol-tetrakis (3-lauryl) thiopropionate and the like.

(Filler)
The photosensitive resin composition according to the present embodiment may further contain a filler. As the filler, an appropriate filler can be selected according to the mechanical properties and thermal properties required for the resin film made of the photosensitive resin composition.
Specific examples of the filler include an inorganic filler and an organic filler.
Specific examples of the inorganic filler include fused crushed silica, molten spherical silica, crystalline silica, secondary aggregated silica, and fine powder silica; alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, and silicon carbide. , Metal compounds such as aluminum hydroxide, magnesium hydroxide, titanium white; talc; clay; mica; glass fiber and the like. As the inorganic filler, one or a combination of two or more of the above specific examples can be used.
Specific examples of the organic filler include organosilicone powder and polyethylene powder. As the organic filler, one or a combination of two or more of the above specific examples can be used.

(Preparation of photosensitive resin composition)
The method for preparing the photosensitive resin composition in the present embodiment is not limited, and a known method can be used depending on the components contained in the photosensitive resin composition.
For example, each of the above components can be prepared by mixing and dissolving in a solvent. Thereby, a photosensitive resin composition as a varnish can be obtained.
In the photosensitive resin composition, the solid content concentration of the entire photosensitive resin composition can be, for example, 10 to 30% by mass.

In the photosensitive resin composition according to the present embodiment, the varnish of the photosensitive resin composition is applied to, for example, a substrate having a relatively large area including a semiconductor element or the like, and then prebaked to dry the resin. It is used by forming a film, then patterning the resin film into a desired shape by exposure and development, and then curing the resin film by post-baking to form a cured film.
When producing the permanent film, the prebaking condition can be, for example, a heat treatment at a temperature of 90 ° C. or higher and 130 ° C. or lower for 30 seconds or longer and 1 hour or shorter. Further, as the post-baking condition, for example, the heat treatment can be performed at a temperature of 150 ° C. or higher and 350 ° C. or lower for 30 minutes or longer and 10 hours or shorter.

The viscosity of the photosensitive resin composition according to the present embodiment can be appropriately set according to the desired thickness of the resin film. The viscosity of the photosensitive resin composition can be adjusted by adding a solvent.
The upper limit of the viscosity of the photosensitive resin composition according to the present embodiment may be, for example, 5000 mPa · s or less, 1800 mPa · s or less, or 1500 mPa · s or less. Further, the lower limit of the viscosity of the photosensitive resin composition according to the present embodiment may be, for example, 1 mPa · s or more, or 10 mPa · s or more, depending on the desired thickness of the resin film.
In the present embodiment, the viscosity of the photosensitive resin composition can be measured by, for example, an E-type viscometer at a temperature of 25 ° C. and 300 seconds after the start of rotation.

The photosensitive resin composition according to the present embodiment preferably has a flash point of 40 ° C. or higher, more preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher. Here, the flash point means a flash point obtained by the tag sealing method based on JIS K 2265-1. By setting the flash point to the above lower limit or higher, the safety of handling in transportation and manufacturing can be maintained.

The surface energy of the photosensitive resin composition according to the present embodiment is preferably 21.0 mN / m or less. Here, the surface energy can be obtained, for example, by evaluating the contact angle with respect to the sputtered Cu and the bare silicon wafer. Specifically, at a temperature of 25 ° C., the contact angle 10 seconds after the varnish of the photosensitive resin composition whose viscosity has been adjusted is dropleted on each substrate can be evaluated by the sessile drop method. it can. For the measurement, for example, a contact angle meter (DROPMASTER-501 manufactured by Kyowa Interface Science Co., Ltd.) can be used. The lower limit of the surface energy is not particularly limited, but can be, for example, 15 mN / m.

(Use)
The cured film obtained by curing the photosensitive resin composition of the present embodiment can be used for applications using a permanent film, for example, for buffer coating, and can be used for various electronic devices.
In the present embodiment, the resin film is a dry film or a cured film of the photosensitive resin composition. That is, the resin film according to the present embodiment is formed by drying or curing the photosensitive resin composition.

The permanent film is, for example, a cured film obtained by applying a photosensitive resin composition, then prebaking, exposing and developing, patterning into a desired shape, and curing by post-baking. It is composed. The permanent film can be used as a protective film, an interlayer film, a dam material, or the like of an electronic device.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example 1)
As a polybenzoxazole precursor, 40.87 g (0.083 mol) and 2,2 of a dicarboxylic acid derivative obtained by reacting 1 mol of diphenyl ether-4,4'-dicarboxylic acid with 2 mol of 1-hydroxybenzotriazole. Place 25.82 g (0.1 mol) of −bis (3-amino-4-hydroxyphenyl) propane in a 4-port separable flask equipped with a thermometer, stirrer, raw material inlet, and dry nitrogen gas inlet tube. , N-Methyl-2-pyrrolidone (3000 g) was added and dissolved. Then, the reaction was carried out at 80 ° C. for 540 minutes using an oil bath to carry out a heat dehydration reaction. Next, 6.98 g (0.0425 mol) of 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride dissolved in 34.88 g of N-methyl-2-pyrrolidone was added, and further. The reaction was completed with stirring for 1 hour.
Next, a reprecipitation method was carried out using a mixed solution of isopropyl alcohol and pure water (mixing ratio 4:96) to separate polybenzoxazole in an organic solvent.
Next, 60 g of the separated polybenzoxazole was dissolved in 110 g of γ-butyrolactone.
Next, a reprecipitation method was carried out using a mixed solution of isopropyl alcohol and pure water (mixing ratio 4:96), and a separator containing polybenzoxazole was separated from γ-butyrolactone using a centrifuge, and isopropyl was used. A mixed solution of alcohol and pure water (mixing ratio 40:60) was used for stirring and washing with a homogenizer, and the mixture was dried.
The residual amount of N-methylpyrrolidone contained in the obtained isolate containing polybenzoxazole was examined by gas chromatography-mass spectrometry and found to be 1000 ppm with respect to the entire isolate.

(Example 2)
55 g of the isolate obtained in Example 1 was dissolved in 100 g of γ-butyrolactone and rewashed.
Next, a reprecipitation method was carried out using a mixed solution of isopropyl alcohol and pure water (mixing ratio 4:96), and the separated product after rewashing containing polybenzoxazole from γ-butyrolactone was separated using a centrifuge. separated. The separated product was stirred and washed with a homogenizer using a mixed solution of isopropyl alcohol and pure water (mixing ratio 40:60), and dried.
When the residual amount of N-methylpyrrolidone contained in the separated product was examined by gas chromatography-mass spectrometry for the obtained separated product after rewashing containing polybenzoxazole, it was 11 ppm with respect to the entire separated product. It was.

(Comparative Example 1)
As a polybenzoxazole precursor, 40.87 g (0.083 mol) and 2,2 of a dicarboxylic acid derivative obtained by reacting 1 mol of diphenyl ether-4,4'-dicarboxylic acid with 2 mol of 1-hydroxybenzotriazole. Place 25.82 g (0.1 mol) of −bis (3-amino-4-hydroxyphenyl) propane in a 4-port separable flask equipped with a thermometer, stirrer, raw material inlet, and dry nitrogen gas inlet tube. , N-Methyl-2-pyrrolidone (3000 g) was added and dissolved. Then, the reaction was carried out at 80 ° C. for 540 minutes using an oil bath to carry out a heat dehydration reaction. Next, 6.98 g (0.0425 mol) of 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride dissolved in 34.88 g of N-methyl-2-pyrrolidone was added, and further. The reaction was completed with stirring for 1 hour.
Next, a reprecipitation method was carried out using a mixed solution of isopropyl alcohol and pure water (mixing ratio 30:70), polybenzoxazole in an organic solvent was separated using a centrifuge, and the separated product was redissolved. The mixture was stirred and washed with a homogenizer using a mixed solution of isopropyl alcohol and pure water (mixing ratio 40:60), and dried.
The residual amount of N-methylpyrrolidone contained in the obtained isolate containing polybenzoxazole was examined by gas chromatography-mass spectrometry and found to be 3% by mass based on the total amount of the isolate.

Claims (8)

A step of synthesizing polybenzoxazole by the reaction of a polybenzoxazole precursor in an organic solvent consisting of N-methylpyrrolidone, and
A step of separating the polybenzoxazole synthesized from the organic solvent, and
A step of washing the polybenzoxazole by mixing the separated polybenzoxazole with a good solvent capable of dissolving the polybenzoxazole other than the organic solvent and dissolving the polybenzoxazole.
A step of separating the isolate containing the polybenzoxazole from the good solvent, and
A method for producing polybenzoxazole. The method for producing a polybenzoxazole according to claim 1, wherein the good solvent contains γ-butyrolactone and at least one of an amide solvent represented by the following chemical formula.

(In the chemical formula (1), R ¹ is an organic group having 1 to 18 carbon atoms, R ² and R ³ satisfy the following (i) or (ii), R ⁴ is hydrogen or methyl, and n is. It is an integer of 0 to 3, and m is 0 or 1. (i) R ² and R ³ are independently hydrogen or organic groups having 1 to 6 carbon atoms. (Ii) R ² and R ^{3 respectively.} Combine with each other to form a ring structure.) The method for producing polybenzoxazole according to claim 1 or 2, wherein the residual amount of the N-methylpyrrolidone contained in the separated product is 1% by mass or less based on the total amount of the separated product. A step of re-cleaning the polybenzoxazole by remixing the polybenzoxazole separated from the good solvent with the good solvent and dissolving the polybenzoxazole.
A step of separating the rewashed polybenzoxazole from the good solvent to obtain a rewashed isolate containing the polybenzoxazole, and
The method for producing a polybenzoxazole according to any one of claims 1 to 3, further comprising. The method for producing polybenzoxazole according to claim 4, wherein the residual amount of the N-methylpyrrolidone contained in the rewashed isolate is 0.3% by mass or less based on the total amount of the rewashed isolate. The method for producing a polybenzoxazole according to any one of claims 1 to 5, wherein the method for separating the polybenzoxazole after washing from the good solvent is a reprecipitation method. The method for producing a polybenzoxazole according to claim 6, further comprising a step of crushing the polybenzoxazole contained in the good solvent before the reprecipitation method. Polybenzoxazole produced by the method for producing polybenzoxazole according to any one of claims 1 to 7.
Photosensitizer and
With solvent
A photosensitive resin composition containing.