Photosensitive resin composition, preparation method and photosensitive dry film

Abstract

The invention discloses a photosensitive resin composition, a preparation method and a photosensitive dry film, and relates to the technical field of advanced electronic packaging. The photosensitive resin composition provided by the invention comprises the following components in parts by mass: a resin glue solution which comprises 100 parts of alkali-soluble photosensitive resin; 0.5 to 20 parts of anhydride double-terminated polyimide resin; and a solvent. The anhydride double-terminated polyimide resin and the alkali-soluble photosensitive resin in the photosensitive resin composition disclosed by the embodiment of the invention can be mutually dissolved in the solvent, and the cured material is not subjected to phase separation, so that the prepared photosensitive dry film has relatively high heat resistance and flexibility.

Description

Technical Field

[0001] The present application relates to the field of advanced electronic packaging technology, and in particular to a photosensitive resin composition and a preparation method thereof, and a photosensitive dry film. Background Art

[0002] In recent years, as advanced packaging technology has developed towards miniaturization and high density, higher requirements have been placed on the solder mask covering the circuit. The solder mask not only needs to prevent solder from flowing into the circuit during the soldering process, but also protect the circuit from moisture, dust and chemicals during use, and reduce the stress generated during bending. Therefore, the solder mask must have excellent heat resistance and flexibility.

[0003] At present, the alkali-soluble photosensitive resin commonly used in the market has good chemical corrosion resistance and strong adhesion, but its heat resistance and flexibility after curing are still insufficient.

[0004] Therefore, it is necessary to provide a photosensitive resin composition having good heat resistance and flexibility after curing. Summary of the invention

[0005] In view of this, the present application provides a photosensitive resin composition, a preparation method, and a photosensitive dry film, aiming to improve the problem that the heat resistance and flexibility of the photosensitive dry film after the existing photosensitive resin composition is cured are still insufficient.

[0006] In a first aspect, an embodiment of the present application provides a photosensitive resin composition, calculated by weight, comprising:

[0007] 100 parts of alkali soluble photosensitive resin;

[0008] 0.5 to 20 parts of anhydride double-terminated polyimide resin;

[0009] and solvents;

[0010] The number average molecular weight of the anhydride double-terminated polyimide resin is 5000 g / mol to 12000 g / mol, the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin can be dissolved in the solvent, and the solid content of the photosensitive resin composition is 40% to 85%.

[0011] In some embodiments of the present application, the photosensitive resin composition further comprises a thermosetting resin and a curing agent, calculated by weight, wherein the thermosetting resin is 15 to 45 parts, and the curing agent is 2 to 10 parts; and / or

[0012] The photosensitive resin composition further comprises a photopolymerizable monomer, wherein the photopolymerizable monomer is 5 to 15 parts; and / or

[0013] The photosensitive resin composition further comprises a photopolymerization initiator, wherein the photopolymerization initiator is 0.5 to 2 parts; and / or

[0014] The photosensitive resin composition further comprises at least one of an inorganic filler, a pigment, and an additive; and / or

[0015] The solvent comprises at least one of an ether solvent, an ester solvent, a ketone solvent, an aromatic solvent and a petroleum solvent; and / or

[0016] The alkali-soluble photosensitive resin comprises a multifunctional epoxy resin containing a photosensitive group and an alkali-soluble group on the molecular chain; and / or

[0017] The mass fraction of the anhydride double-terminated polyimide resin in the photosensitive resin composition is 10 to 16 parts; and / or

[0018] The number average molecular weight of the anhydride double-terminated polyimide resin is 7000 g / mol to 10000 g / mol; and / or

[0019] The anhydride double-terminated polyimide resin comprises dianhydride units and diamine units, wherein the diamine units comprise carboxyl-containing diamine units and non-carboxyl-containing diamine units; and the molar ratio of the carboxyl-containing diamine units to the non-carboxyl-containing diamine units is 1:1.

[0020] In some embodiments of the present application, the photosensitive group includes at least one of a carbon-carbon double bond, a carbonyl group and a peroxide group; and / or

[0021] The alkali-soluble group comprises at least one of a carboxyl group, anhydride group and an ester group; and / or

[0022] The acid value of the alkali-soluble photosensitive resin is 40 mg KOH / g to 200 mg KOH / g; and / or

[0023] The number average molecular weight of the alkali-soluble photosensitive resin is 7000 g / mol to 9000 g / mol.

[0024] In some embodiments of the present application, the structural unit of the anhydride double-terminated polyimide resin includes at least one of an ether bond, a trifluoromethyl group and a macromolecular side group; and / or

[0025] The photopolymerizable monomer comprises at least one of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, methyl (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, lauryl (meth)acrylate, dipropylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, neopentyl glycol diethoxy / propoxy di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and polydipentaerythritol hexa(meth)acrylate; and / or

[0026] The photopolymerization initiator includes at least one of photopolymerization initiator 907, oxime ester photopolymerization initiator, acylphosphine oxide photopolymerization initiator, acetophenone photopolymerization initiator, benzoin and its alkyl ether photopolymerization initiator, anthraquinone photopolymerization initiator, thioxanthone photopolymerization initiator, ketal photopolymerization initiator, and benzophenone photopolymerization initiator; and / or

[0027] The thermosetting resin comprises at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl phenol epoxy resin, biphenol epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, brominated bisphenol A epoxy resin, novolac epoxy resin, trisphenol methane epoxy resin, N-glycidyl epoxy resin, triglycidyl isocyanurate, cresol soluble epoxy resin, 2,6-xylenol dimer diglycidyl ether, alicyclic epoxy resin and xylene epoxy resin; and / or

[0028] The curing agent includes at least one of dicyandiamide, melamine, diethylenetriamine, triethanolamine, polyamide, vinylamine, ethyl carbamate, methyl epoxyamine, and ethylphenylenediamine.

[0029] In some embodiments of the present application, the mass fraction of the inorganic filler in the photosensitive resin composition is 10 parts to 80 parts; and / or

[0030] The inorganic filler comprises at least one of barium sulfate, silicon dioxide, calcium oxide, barium titanate, magnesium carbonate, calcium carbonate, talc, aluminum oxide, aluminum hydroxide, titanium oxide, fumed silica, clay, mica powder and kaolin; and / or

[0031] The particle size of the inorganic filler is 0.001 μm to 20 μm; and / or

[0032] The pigment comprises at least one of phthalocyanine green, phthalocyanine blue, titanium dioxide, carbon black and lithopone; and / or

[0033] The additives include at least one of a curing accelerator, a photoinitiator aid, a diluent, a thixotropic tackifier, a leveling agent, an inhibitor, a tackifier, a defoamer, a coupling agent, an antioxidant and a rust inhibitor; and / or

[0034] The mass fraction of the additive in the photosensitive resin composition is 0.05 parts to 20 parts.

[0035] In some embodiments of the present application, the ether solvent includes at least one of ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol ethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether; and / or

[0036] The ester solvent includes at least one of ethyl acetate, butyl acetate and carbitol acetate; and / or

[0037] The ketone solvent includes at least one of cyclohexanone, butanone and isophorone; and / or

[0038] The aromatic solvent comprises at least one of toluene, xylene and tetramethylbenzene; and / or

[0039] The petroleum solvent includes naphtha; and / or

[0040] The diamine unit comprises at least one of 3,5-diaminobenzoic acid, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane, and 3,4-diaminobenzoic acid; and / or

[0041] The dianhydride unit includes 4,4'-(4,4'-isopropyldiphenoxy) diphthalic anhydride.

[0042] In some embodiments of the present application, the solvent is carbitol acetate.

[0043] A second aspect of the present application provides a method for preparing a photosensitive resin composition, the preparation method comprising the following steps:

[0044] Prepare a transparent mixed glue solution, wherein the mixed glue solution comprises anhydride double-terminated polyimide resin, an alkali-soluble photosensitive resin and a solvent;

[0045] A thermosetting resin, a photopolymerizable monomer, a photopolymerization initiator and a curing agent are added to the mixed adhesive to obtain the photosensitive resin composition.

[0046] In some embodiments of the present application, the step of preparing the mixed glue solution includes:

[0047] Preparation of the anhydride double-terminated polyimide resin and / or preparation of the alkali-soluble photosensitive resin; wherein,

[0048] The steps of preparing the anhydride double-terminated polyimide resin include: subjecting a dianhydride monomer and a diamine monomer to a condensation reaction in a solvent to obtain a polyamic acid solution, wherein the molar ratio of the dianhydride monomer to the diamine monomer is 2 to 4:1; subjecting the polyamic acid solution to imidization to obtain a polyimide;

[0049] The step of preparing the alkali-soluble photosensitive resin comprises: subjecting a multifunctional epoxy compound and an unsaturated carboxylic acid to an esterification reaction to obtain an ester, and then reacting the obtained ester with a polyacid anhydride to obtain the alkali-soluble photosensitive resin.

[0050] A third aspect of the present application provides a photosensitive dry film, which is obtained by curing a photosensitive resin composition prepared by the photosensitive resin composition or the method for preparing a photosensitive resin composition.

[0051] Beneficial effects:

[0052] The anhydride double-terminated polyimide resin and the alkali-soluble photosensitive resin in the photosensitive resin composition of the embodiment of the present application can be dissolved in each other, so that the prepared photosensitive dry film has higher heat resistance and flexibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 This is a microscope image of a resin solution composed of an alkali-soluble photosensitive resin, PI-1, and carbitol acetate. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0057] In this application, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order.

[0058] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0059] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0060] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0061] In recent years, as advanced packaging technology has developed towards miniaturization and high density, higher requirements have been placed on the solder mask covering the circuit. The solder mask not only needs to prevent solder from flowing into the circuit during the soldering process, but also protect the circuit from moisture, dust and chemicals during use, and reduce the stress generated during bending. Therefore, the solder mask must have excellent heat resistance and flexibility.

[0062] At present, the alkali-soluble photosensitive resin commonly used in the market has good chemical corrosion resistance and strong adhesion, but its heat resistance and flexibility after curing are still insufficient.

[0063] In order to improve the heat resistance of photosensitive solder mask ink, inorganic fillers such as silica are generally added in the relevant technology. For example, Chinese invention patent CN110895381A discloses a technology for enhancing the heat resistance of solder mask ink by adding silica and materials containing vinyl silica. The surfaces of these added inorganic fillers have functional groups that can react with resins, thereby increasing the crosslinking density between the inorganic fillers and the resin, and effectively improving the thermal properties. However, due to the limited amount of inorganic fillers added, this method has certain limitations in enhancing mechanical and thermal properties. In addition, a high proportion of inorganic fillers will lead to a decrease in the leveling and photolithography performance of the ink, and affect the elongation at break, while also increasing the risk of interface failure.

[0064] Some other related technologies mentioned that a highly heat-resistant resin (such as a polyimide resin) can be added to a photosensitive resin composition to improve the heat resistance of the cured product. Taking polyimide resin as an example, an alkali-soluble polyimide resin is added to a photosensitive resin composition to improve the heat resistance of the composition in the related technology, but it does not consider the compatibility of the alkali-soluble polyimide resin with the alkali-soluble photosensitive resin. There is a problem that the added polyimide resin is insoluble in the alkali-soluble photosensitive resin or the added polyimide resin is excessive, resulting in unsatisfactory mechanical properties and temperature resistance of the obtained cured product.

[0065] In view of this, an embodiment of the present application provides a photosensitive resin composition, which can be used in semiconductor packaging. For example, the photosensitive resin composition is used to prepare photosensitive solder resist ink, prepare circuit boards, prepare FC-BGA substrates, etc. The photosensitive resin composition can also be used in other scenarios requiring photosensitivity, high heat resistance and high flexibility, which are not limited here.

[0066] In the embodiment of the present application, the photosensitive resin composition includes, calculated by weight:

[0067] 100 parts of alkali soluble photosensitive resin;

[0068] 0.5 to 20 parts of anhydride double-terminated polyimide resin;

[0069] and solvent

[0070] The number average molecular weight of the anhydride double-terminated polyimide resin is 5000 g / mol to 15000 g / mol, the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin can be dissolved in the solvent, and the solid content of the photosensitive resin composition is 40%-85%.

[0071] Exemplarily, the solid content of the photosensitive resin composition is 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% and any value between the above two values. Further, the solid content of the photosensitive resin composition is 50% to 70%. It should be noted that the solid content in this application refers to the ratio of the mass of the remaining substance after removing the solvent from the photosensitive resin composition to the initial mass, that is, the ratio of other components in the photosensitive resin composition except the solvent to the total amount of the photosensitive resin composition.

[0072] Exemplarily, exemplary, the anhydride double-terminated polyimide resin in the photosensitive resin composition is 0.5 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts and any value between the above two values. Further, the mass fraction of the anhydride double-terminated polyimide resin in the photosensitive resin composition is 10 parts to 16 parts. In this way, the material prepared after the obtained photosensitive resin composition is cured can have better heat resistance and flexibility. In the embodiment of the present application, a polyimide resin with a specific content and molecular weight of an anhydride double-terminated polyimide resin is added to the photosensitive resin composition. The anhydride double-terminated polyimide resin has good compatibility with the alkali-soluble photosensitive resin and can be dissolved in the same solvent with the alkali-soluble photosensitive resin to form a uniform and stable transparent resin glue. The photosensitive resin composition in the present application does not undergo phase separation after the solvent is removed and after cross-linking and curing reaction, so that the material prepared by curing the photosensitive resin composition provided in the present application has high heat resistance and flexibility. In some embodiments of the present application, the photosensitive resin composition also includes a thermosetting resin and a curing agent by mass, the thermosetting resin is 15 to 45 parts, and the curing agent is 2 to 10 parts.

[0073] Illustratively, the amount of the thermosetting resin in the photosensitive resin composition is 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, and any value between the above two values.

[0074] Illustratively, the amount of curing agent in the photosensitive resin composition is 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, and any value between the above two values.

[0075] In some embodiments of the present application, the photosensitive resin composition further includes a photopolymerizable monomer, and the photopolymerizable monomer is 5 parts to 15 parts by mass.

[0076] Illustratively, the photopolymerizable monomer in the photosensitive resin composition is 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, and any value between the above two values.

[0077] In some embodiments of the present application, the photosensitive resin composition further comprises a photopolymerization initiator, and the photopolymerization initiator is 0.5 to 2 parts by weight. Exemplarily, the photopolymerization initiator in the photosensitive resin composition is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, and any value between the above two values.

[0078] In some embodiments of the present application, an alkali-soluble photosensitive resin, an anhydride-diblocked polyimide resin and a portion of a solvent may be mixed to obtain a transparent resin glue. It should be noted that the solvent in the present application is not particularly limited, and only needs to be able to dissolve the alkali-soluble photosensitive resin and the anhydride-diblocked polyimide resin.

[0079] Furthermore, the solvent includes at least one of ether solvents, ester solvents, ketone solvents, aromatic solvents and petroleum solvents.

[0080] Specifically, the ether solvent includes at least one of ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol ethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

[0081] In some embodiments of the present application, the ester solvent includes at least one of ethyl acetate, butyl acetate, and carbitol acetate. Further, carbitol acetate includes at least one of ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol ethyl ether acetate, and dipropylene glycol butyl ether acetate.

[0082] It should be noted that the solubility of polyimide is poor. In the related art, solvents such as NMP or DMF are generally used to dissolve polyimide, but NMP or DMF has high toxicity and can pollute the environment. In this embodiment, carbitol acetate is used as a solvent. The inventor found through experiments that carbitol acetate is used in the photosensitive resin composition in the present application, and has a relatively balanced solubility performance for the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin. A stable resin glue can be prepared in the range of 5 to 20 parts of the anhydride double-terminated polyimide resin content, so that the prepared photosensitive resin composition has good stability, low volatility and good film-forming properties, thereby improving printing quality and stability. In addition, carbitol acetate has a relatively small odor compared to NMP or DMF, and has low toxicity, which is conducive to improving the safety of the production and operating environment.

[0083] Specifically, the ketone solvent includes at least one of cyclohexanone, butanone and isophorone.

[0084] Specifically, the aromatic solvent includes at least one of toluene, xylene, and tetramethylbenzene.

[0085] Specifically, the petroleum solvent includes naphtha. Exemplarily, the naphtha may be at least one of oxidized naphtha and solvent naphtha.

[0086] In some embodiments of the present application, the number average molecular weight of the anhydride double-terminated polyimide resin is 5000 g / mol to 12000 g / mol, and further, the number average molecular weight of the anhydride double-terminated polyimide resin is 7000 g / mol to 10000 g / mol. The number average molecular weight of the alkali-soluble photosensitive resin is 7000 g / mol to 9000 g / mol. In this way, it is beneficial to make the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin have good mutual solubility, and the obtained photosensitive dry film has high mechanical properties, high heat resistance and high flexibility. In some embodiments of the present application, the anhydride double-terminated polyimide resin includes a dianhydride structural unit and a diamine structural unit, and the diamine structural unit includes a carboxyl-containing diamine structural unit and a carboxyl-free diamine structural unit; the molar ratio of the carboxyl-containing diamine structural unit to the carboxyl-free diamine structural unit is 1:1.

[0087] In some embodiments of the present application, the structural unit of the polyimide resin with double end capping of anhydride includes at least one of the groups such as ether bond, trifluoromethyl, carboxyl and macromolecular side groups. Exemplarily, the macromolecular side groups can be aromatic rings (such as phenyl, phenoxy, biphenyl), fatty chains or heterocycles. In this way, it is beneficial to increase the solubility of polyimide. It is understandable that the structural unit of the polyimide resin includes a carboxyl group, which can make the polyimide with double end capping of anhydride react with the alkali-soluble photosensitive resin in chemical structure, thereby reducing the possibility of incompatibility and phase separation of the two systems, which is beneficial to further improve the mechanical properties, high heat resistance and high flexibility of the obtained photosensitive dry film.

[0088] In some embodiments of the present application, the diamine monomer for synthesizing the anhydride double-terminated polyimide resin contains groups such as ether bonds, trifluoromethyl groups and macromolecular side groups.

[0089] Exemplarily, the diamine monomer for synthesizing the anhydride double-terminated polyimide resin is selected from at least one of 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,3-bis(3-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl)propane, 9,9-bis(4-aminophenyl)fluorene, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.

[0090] For example, the carboxyl-containing diamine for synthesizing the anhydride-dicapped polyimide resin is selected from one of 3,5-diaminobenzoic acid and 3,4-diaminobenzoic acid.

[0091] In some embodiments of the present application, the dianhydride monomer for synthesizing the anhydride double-terminated polyimide resin contains groups such as ether bonds, trifluoromethyl groups and macromolecular side groups.

[0092] Exemplarily, the dianhydride monomer for synthesizing the anhydride double-terminated polyimide resin is selected from at least one of 4,4'-oxydiphthalic anhydride, 4,4'-(hexafluoroisopropylidene) diphthalic anhydride, bisphenol A dianhydride, p-phenylene-diphthalic anhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 4,4'-p-phenylenedioxydiphthalic anhydride, hexafluoro dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, and 1,2-ethylenebis[1,3-dihydro-1,3-dioxoisobenzofuran-5-carboxylate].

[0093] In some embodiments of the present application, the steps of preparing the anhydride double-terminated polyimide resin include:

[0094] Step (1) polycondenses dianhydride monomers and diamine monomers in a solvent to obtain a polyamic acid solution, wherein the molar ratio of the dianhydride monomers to the diamine monomers is (2-4):1.

[0095] Specifically, the solvent in step (1) is a polar organic solvent. It should be noted that the specific conditions for the polycondensation reaction of the dianhydride monomer and the diamine monomer do not belong to the main improvement of the present application and are not limited here.

[0096] Step (2) imidizing the polyamic acid solution prepared in step (1) to obtain polyimide.

[0097] Specifically, in step (2), the polyamic acid is chemically imidized into polyimide under the action of a dehydrating agent and a catalyst.

[0098] It should be noted that, for the dianhydride monomer and the diamine monomer in step (1), please refer to the above, and no further description is given here. It is understandable that the dianhydride monomer forms the dianhydride structural unit in the anhydride double-terminated polyimide resin after polymerization, and the diamine monomer forms the diamine structural unit in the anhydride double-terminated polyimide resin after polymerization.

[0099] In some embodiments of the present application, the step of preparing the anhydride double-terminated polyimide resin is performed in an inert atmosphere. Exemplarily, the inert atmosphere is a nitrogen atmosphere.

[0100] In some embodiments of the present application, the process of preparing the anhydride double-terminated polyimide resin is carried out under stirring conditions. It should be noted that the stirring speed and stirring time are not the main improvements of the present application and are not limited here.

[0101] Exemplarily, the reaction time of step (1) is 4 h to 10 h.

[0102] Illustratively, the polar solvent in step (1) includes at least one of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), tetrahydrofuran, γ-butyrolactone, m-cresol, chloroform, hexamethylphosphoric acid triamide and tetramethyl urea.

[0103] In certain specific embodiments, the specific operation of step (1) is: in a nitrogen atmosphere, two diamine monomers (i.e., a carboxyl-containing diamine monomer and a non-carboxyl-containing diamine monomer) are dissolved in a polar organic solvent, and after adding a dianhydride monomer, the mixture is stirred and reacted in an ice bath to obtain a polyamic acid solution.

[0104] In some embodiments of the present application, in step (2), the dehydrating agent includes at least one of anhydride-tertiary amine dehydrating agent, acetyl chloride-tertiary amine dehydrating agent and thionyl chloride-tertiary amine dehydrating agent. Further, the molar ratio of the anhydride to the tertiary amine is 1 to 1.2:1. The anhydride includes at least one of acetic anhydride, trifluoroacetic anhydride and phthalic anhydride. The tertiary amine includes at least one of pyridine and triethylamine.

[0105] In some embodiments of the present application, the temperature of the imidization reaction in step (2) is ≤90° C., and the reaction time is 0.5 h to 6 h.

[0106] In certain specific embodiments, the specific operation of step (2) is: below 90° C., adding a mixed solution of a dehydrating agent and a catalyst dropwise using a constant pressure dropping funnel and reacting for 0.5 to 6 hours to obtain the polyimide solution.

[0107] In some embodiments of the present application, the step of preparing the anhydride double-terminated polyimide resin further comprises:

[0108] Step (3) precipitates the polyimide and filters it to obtain polyimide resin powder.

[0109] Exemplarily, the polyimide resin solution containing anhydride double end-capping obtained in step (2) is precipitated with anhydrous ethanol, and then filtered to obtain a precipitate, and then the precipitate is dried to obtain a polyimide resin powder. For example, the precipitate is filtered by suction filtration, and the precipitate is dried in a vacuum oven to obtain a polyimide resin powder.

[0110] In some embodiments of the present application, the type of the alkali-soluble photosensitive resin is not particularly limited. Exemplarily, the alkali-soluble photosensitive resin includes a multifunctional epoxy resin containing a photosensitive group and an alkali-soluble group on the molecular chain. Further, the photosensitive group includes at least one of a carbon-carbon double bond, a carbonyl group and a peroxide group; and / or, the alkali-soluble group includes at least one of a carboxyl group, an anhydride group and an ester group. In this way, it is beneficial to make the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin have better mutual solubility and reduce the preparation cost of the photosensitive resin composition.

[0111] In some embodiments of the present application, the acid value of the alkali-soluble photosensitive resin is 40 mg KOH / g to 200 mg KOH / g. Further, the acid value of the alkali-soluble photosensitive resin is 50 mg KOH / g to 180 mg KOH / g.

[0112] In some embodiments of the present application, the method for preparing the alkali-soluble photosensitive resin comprises the following steps: subjecting a multifunctional epoxy compound and an unsaturated carboxylic acid to an esterification reaction, and then reacting the obtained ester with a polyacid anhydride to obtain the alkali-soluble photosensitive resin.

[0113] Exemplarily, the multifunctional epoxy compound includes difunctional and trifunctional epoxy resins. Specifically, the multifunctional epoxy compound includes at least one of bisphenol A novolac epoxy resin, naphthalene epoxy resin, phenol novolac epoxy resin, glycidylamine epoxy resin, o-cresol novolac epoxy resin, alkylphenol novolac epoxy resin, dicyclopentadiene epoxy resin, tetraphenol ethane epoxy resin, trihydroxybenzene methane epoxy resin, diglycidyl phthalate resin and epoxy compounds of condensates of phenols and aromatic aldehydes having phenolic hydroxyl groups.

[0114] It should be noted that the unsaturated carboxylic acid in the embodiment of the present application can be an unsaturated monocarboxylic acid or an unsaturated polycarboxylic acid. The polyacid anhydride in the embodiment of the present application can be a saturated polyacid anhydride or an unsaturated polyacid anhydride, which is not limited here.

[0115] Exemplarily, the unsaturated carboxylic acid includes at least one of acrylic acid, methacrylic acid, acrylic acid dimer, cinnamic acid, β-styryl acrylic acid, β-furfuryl acrylic acid, α-cyanocinnamic acid, crotonic acid, the reaction product of a saturated or unsaturated dibasic acid anhydride and a hydroxyl-containing (meth)acrylate, the reaction product of a saturated or unsaturated dibasic acid and an unsaturated monoglycidyl compound, and the like.

[0116] Exemplarily, the polyanhydride includes at least one of a dibasic anhydride, a polybasic aromatic carboxylic anhydride and other anhydride derivatives. Specifically, the dibasic anhydride includes but is not limited to at least one of maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, itaconic anhydride, methylhexahydrophthalic anhydride and methyltetrahydrophthalic anhydride. The polybasic aromatic carboxylic anhydride includes but is not limited to at least one of trimellitic anhydride, pyromellitic anhydride and benzophenonetetracarboxylic dianhydride. The anhydride derivative includes but is not limited to at least one of 5-(2,5-dioxytetrahydrofuranyl)-3-methyl-3-cyclohexenyl-1,2 dicarboxylic anhydride.

[0117] Preferably, the polyacid anhydride includes tetrahydrophthalic anhydride, hexahydrophthalic anhydride and succinic anhydride. This is beneficial to reduce the viscosity of the photosensitive resin, improve the chemical stability, thermal stability and excellent adhesion of the photosensitive resin, and promote cross-linking.

[0118] In some embodiments of the present invention, the mass ratio of the multifunctional epoxy compound, the unsaturated monocarboxylic acid and the saturated or unsaturated polyacid anhydride is (2.5-4): (0.5-1.1): (0.5-1.1).

[0119] In some embodiments of the present invention, the type of the photopolymerizable monomer is not particularly limited. Exemplarily, the photopolymerizable monomer includes hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, methyl (meth)acrylate, pentaerythritol tri (meth)acrylate, dipentaerythritol penta (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 1,6-hexanediol di (meth)acrylate, lauryl (meth)acrylate, di / tripropylene glycol di (meth)acrylate, ethoxylated bisphenol A di (meth)acrylate, neopentyl glycol diethoxy / propoxy di (meth)acrylate, di / triethylene glycol di (meth)acrylate, trimethylolpropane tri (meth)acrylate, pentaerythritol tetra (meth)acrylate and polydipentaerythritol hexa (meth)acrylate at least one.

[0120] Preferably, the photopolymerizable monomer includes polydipentaerythritol hexa(meth)acrylate. It is understood that the multiple acrylate functional groups in the structure of polydipentaerythritol hexa(meth)acrylate can provide a higher degree of crosslinking, thereby enhancing the mechanical strength and heat resistance of the final material. Compared with other highly crosslinked monomers, polydipentaerythritol hexaacrylate has better flexibility and is suitable for applications requiring a certain degree of elasticity.

[0121] In the technical solution of the present invention, the type of the photopolymerization initiator is not particularly limited. For example, the photopolymerization initiator includes at least one of photopolymerization initiator 907, oxime ester photopolymerization initiator, acylphosphine oxide photopolymerization initiator, acetophenone photopolymerization initiator, benzoin and its alkyl ether photopolymerization initiator, anthraquinone photopolymerization initiator, thioxanthone photopolymerization initiator, ketal photopolymerization initiator, and benzophenone photopolymerization initiator. That is, the above can be used alone or in any combination.

[0122] Furthermore, the photopolymerization initiator is preferably an oxime ester photopolymerization initiator. It is understood that the oxime ester initiator has a high initiation efficiency under ultraviolet light irradiation, can quickly start the polymerization reaction, can complete the curing process in a short time, and improve production efficiency.

[0123] Specifically, the oxime ester-based photopolymerization initiators include, but are not limited to, OXE-1, OXE-2, and the like.

[0124] Specifically, the acylphosphine oxide-based photopolymerization initiator includes, but is not limited to, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like.

[0125] Specifically, the acetophenone-based photopolymerization initiator includes, but is not limited to, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2,2-diethoxy-2-phenylacetophenone, and the like.

[0126] Specifically, benzoin and its alkyl ether photopolymerization initiators include, but are not limited to, benzoin, benzoin ethyl ether, benzoin methyl ether, benzoin isopropyl ether, and the like.

[0127] Specifically, the anthraquinone-based photopolymerization initiator includes, but is not limited to, 2-methylanthraquinone, 2-tert-butylanthraquinone, 2-ethylanthraquinone, 1-chloroanthraquinone, and the like.

[0128] Specifically, the thioxanthone-based photopolymerization initiator includes, but is not limited to, 2,4-dimethylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and the like.

[0129] Specifically, the ketal-based photopolymerization initiator includes, but is not limited to, acetophenone dimethyl ketal, benzyl dimethyl ketal, and the like.

[0130] Specifically, the benzophenone-based photopolymerization initiator includes, but is not limited to, benzophenone, 4,4'-bis(diethylamino)benzophenone, and the like.

[0131] In the technical solution of the present invention, the type of the thermosetting resin is not particularly limited. For example, the thermosetting resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl phenol epoxy resin, biphenyl phenol epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, brominated bisphenol A epoxy resin, novolac epoxy resin, trisphenol methane epoxy resin, N-glycidyl epoxy resin, triglycidyl isocyanurate, cresol soluble epoxy resin, 2,6-xylenol dimer diglycidyl ether, alicyclic epoxy resin and xylene epoxy resin.

[0132] Preferably, bisphenol A epoxy resin. It should be noted that bisphenol A epoxy resin provides high strength and rigidity after curing, can form strong adhesion with a variety of substrates, and is conducive to enhancing the application range and mechanical properties of the photosensitive resin composition.

[0133] In some embodiments of the present application, the alkali-soluble photosensitive resin further comprises an inorganic filler. Further, the inorganic filler in the alkali-soluble photosensitive resin is 10 to 80 parts by weight. In this way, the obtained photosensitive dry film can have higher heat resistance and mechanical properties.

[0134] Exemplarily, the inorganic filler includes at least one of barium sulfate, silicon dioxide, calcium oxide, barium titanate, magnesium carbonate, calcium carbonate, talc, aluminum oxide, aluminum hydroxide, titanium oxide, fumed silica, clay, mica powder and kaolin.

[0135] Further, the inorganic filler includes at least one of barium sulfate, silicon dioxide, aluminum oxide, aluminum hydroxide and calcium carbonate. It should be noted that barium sulfate and aluminum oxide can significantly improve the strength and rigidity of the material after curing of the photosensitive resin composition in the present application, and enhance the wear resistance. Aluminum hydroxide and aluminum oxide have high thermal stability and are suitable for high temperature applications. Silicon dioxide and calcium carbonate can improve the fluidity of the photosensitive resin composition in the present application, thereby making the photosensitive resin composition in the present application easy to process.

[0136] Exemplarily, the particle size of the inorganic filler is 0.001 μm to 20 μm, preferably 0.05 μm to 15 μm, and more preferably 0.05 μm to 3 μm. It should be noted that the use of inorganic fillers with smaller particle sizes (such as 0.05 μm to 3 μm) helps to improve the dispersibility of the inorganic filler in the photosensitive resin composition, helps to avoid the precipitation and aggregation of the inorganic filler in the photosensitive resin composition, and helps to ensure the stability of the performance of the photosensitive resin composition.

[0137] It should be noted that the particle size of the inorganic filler may also be in other ranges and there is no particular limitation thereto.

[0138] In some embodiments of the present application, the alkali-soluble photosensitive resin further comprises a pigment. For example, the pigment comprises at least one of phthalocyanine green, phthalocyanine blue, titanium dioxide, carbon black and lithopone. Further, the pigment is a pigment free of free halogen. This is conducive to reducing the pollution of halogen to the environment.

[0139] In some embodiments of the present application, the photosensitive resin composition further comprises an additive, which exemplarily comprises at least one of an epoxy resin curing accelerator, a photoinitiator auxiliary, a diluent, a thixotropic tackifier, a leveling agent, an inhibitor, a tackifier, a defoamer, a coupling agent, an antioxidant, and a rust inhibitor.

[0140] Furthermore, calculated by weight, the additive in the photosensitive resin composition is 0.05 to 20 parts.

[0141] The present invention also provides a method for preparing a photosensitive resin composition, comprising the following steps:

[0142] A mixed glue solution is prepared, wherein the mixed glue solution comprises anhydride double-terminated polyimide resin, an alkali-soluble photosensitive resin and a solvent.

[0143] Specifically, the anhydride double-terminated polyimide, the alkali-soluble photosensitive resin and part of the solvent are mixed to obtain the resin glue solution.

[0144] It should be noted that the anhydride double-terminated polyimide, the alkali-soluble photosensitive resin and the first solvent have been described in detail above and will not be described again here.

[0145] The photosensitive resin composition is obtained by adding a thermosetting resin, a photopolymerizable monomer, a photopolymerization initiator, a curing agent and another part of a solvent into the resin glue.

[0146] Specifically, the mixing is performed by stirring at a rotation speed of 500 rpm to 5000 rpm for 4 to 8 hours, and then mixing with a three-roll mill to obtain the photosensitive resin composition.

[0147] The present application also provides a method for preparing a photosensitive dry film, comprising the following steps:

[0148] The photosensitive resin composition is coated on a carrier. For example, the photosensitive resin composition is coated on a carrier film using a coating device such as a four-sided coater, a gravure roll coater, a notch wheel coater, a reverse roll coater, or a curtain coater. It should be noted that the preparation process of coating the photosensitive resin composition on a carrier does not belong to the main improvement point of the present application and will not be further expanded here.

[0149] The photosensitive resin composition coated on the carrier is dried and cured to obtain a photosensitive dry film. Furthermore, a protective film is attached to the obtained photosensitive dry film.

[0150] Specifically, the curing is performed under heating conditions. For example, the heating temperature is 10 to 200° C., more preferably 150 to 180° C. The heating time is 10 to 90 minutes, more preferably 50 to 70 minutes.

[0151] In some embodiments of the present application, the thickness of the photosensitive dry film is 5 to 100 μm, more preferably 10 to 60 μm, and particularly preferably 15 to 40 μm.

[0152] The photosensitive resin composition in the present application is further described below in combination with specific embodiments and experimental test results.

[0153] Example 1

[0154] (1) Preparation of anhydride double-terminated polyimide resin

[0155] Step 11: Add 1.55 g of 3,5-diaminobenzoic acid and 20 g of N-methylpyrrolidone solution into a three-necked flask at room temperature, and stir under a nitrogen atmosphere until dissolved.

[0156] Step 12: 2.04 g of 4,4'-diaminodiphenyl ether and 20 g of N-methylpyrrolidone solution were added to a three-necked flask at room temperature, and stirred under a nitrogen atmosphere until dissolved.

[0157] Step 13: 15.93 g of 4,4'-(4,4'-isopropyldiphenoxy)diphthalic anhydride and 140 g of N-methylpyrrolidone solution were added in batches to a three-necked flask at room temperature, and stirred under a nitrogen atmosphere until dissolved.

[0158] Step 14: The mixed solution obtained in step 13 is reacted in an ice bath for 4 hours to generate a polyamic acid solution.

[0159] Step 15: A mixed solution of 4.08 g of acetic anhydride and 3.16 g of pyridine was added dropwise into a three-necked flask through a constant pressure dropping funnel to carry out a chemical imidization reaction.

[0160] Step 16: Heat the mixed solution to 90° C. in an oil bath and perform chemical imidization for 6 h to generate a polyimide solution.

[0161] Step 17: Slowly add the above polyimide solution dropwise into anhydrous ethanol and stir continuously with a mechanical stirring paddle. After the addition is completed, collect the white polyimide precipitate by suction filtration using a Buchner funnel, and dry it in a vacuum oven for 48 hours to constant weight to obtain an anhydride double-terminated polyimide resin (No. PI-1) with a number average molecular weight of 7000 g / mol to 10000 g / mol.

[0162] (2) Preparation of alkali-soluble photosensitive resin

[0163] Step 21: Add 210 g of bisphenol A epoxy resin SQAN-203 and 195 g of diethylene glycol methyl ether acetate into a four-necked flask at room temperature, stir under a nitrogen atmosphere, insert a thermocouple probe of a thermometer into the solution, and slowly raise the temperature to 90°C.

[0164] Step 22: After the bisphenol A epoxy resin SQAN-203 is completely dissolved, add 0.5 g of hydroquinone and raise the temperature to 110° C. When the system temperature stabilizes, slowly drop 72 g of acrylic acid and 1 g of triphenylphosphine using a constant pressure dropping funnel.

[0165] Step 23: Take a sample every two hours to measure the acid value until the acid value drops below 5 mgKOH / g, and the reaction is considered complete to obtain epoxy acrylate.

[0166] Step 24: Use a vacuum pump to extract the water vapor in the four-necked flask for about 10 minutes, then reduce the temperature from 110°C to 90°C, and add 75 g of cis-4-cyclohexene-1,2-dicarboxylic anhydride after the temperature stabilizes.

[0167] Step 25: Wait until the anhydride is completely dissolved and the temperature stabilizes at 90°C again, then take samples every two hours and titrate the acid value to monitor the progress of the reaction. Stop the reaction when the acid value drops below 10 mgKOH / g.

[0168] Step 26: After the reaction is completed, the product is cooled to room temperature, a certain proportion of methanol-water solution is prepared, the reaction solution is slowly poured into the methanol-water solution and stirred at high speed using an overhead stirrer. After the product is precipitated, the rotation speed is reduced, and the product is taken out after stirring for about 30 minutes. The product is placed in an acetone solution and dissolved using an ultrasonic device. After complete dissolution, these two steps are repeated for about three times. Finally, the product is placed in a constant temperature vacuum drying oven at 45°C for about 48 hours to remove water vapor and volatile solvents, and finally alkali-soluble photosensitive resin-1 is obtained.

[0169] (3) Preparation of photosensitive resin composition

[0170] Step 31: Dissolve 1.9 g of PI-1 and 19 g of alkali-soluble photosensitive resin-1 in 12 g of diethylene glycol methyl ether acetate solvent, and stir mechanically to obtain a resin glue solution.

[0171] Step 32: The above-mentioned photosensitive resin mixture glue is mixed with 6g of thermosetting epoxy resin YX400, 0.12g of melamine, 0.48g of dicyandiamide, 0.2g of photopolymerization initiator OXE02, 1.5g of polydipentaerythritol hexaacrylate, 7.5g of silica, 2.5g of barium sulfate, 0.4g of phthalocyanine green, and 10g of diethylene glycol methyl ether acetate solvent under mechanical stirring at a speed of 1000 rpm for 6 hours, and after mixing evenly, it is ground with a three-roll mill to finally prepare a photosensitive resin composition.

[0172] Example 2

[0173] The difference between it and embodiment 1 is:

[0174] (1) Preparation of anhydride double-terminated polyimide resin

[0175] The difference between it and Example 1 is that the "2.04 g of 4,4'-diaminodiphenyl ether and 20 g of N-methylpyrrolidone solution" in step 12 is replaced by "5.29 g of 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane and 40 g of N-methylpyrrolidone solution" to prepare an anhydride double-terminated polyimide resin (No. PI-2) with a number average molecular weight of 7000 g / mol to 10000 g / mol.

[0176] (3) Preparation of photosensitive resin composition

[0177] The difference between the embodiment 1 and the embodiment 1 is that the polyimide resin with double end-capping of anhydride is PI-2.

[0178] Example 3

[0179] The difference between it and embodiment 1 is:

[0180] (1) Preparation of anhydride double-terminated polyimide resin

[0181] The difference between it and Example 1 is that the "1.55 g of 3,5-diaminobenzoic acid and 20 g of N-methylpyrrolidone solution" in step 11 is replaced by "1.55 g of 3,4-diaminobenzoic acid and 20 g of N-methylpyrrolidone solution" to prepare an anhydride double-terminated polyimide resin (No. PI-3) with a number average molecular weight of 7000 g / mol to 10000 g / mol.

[0182] (2) Preparation of photosensitive resin composition

[0183] The difference between the embodiment 1 and the embodiment 1 is that the polyimide resin with acid anhydride double end-capping is PI-3.

[0184] Example 4

[0185] The difference between it and embodiment 1 is:

[0186] (1) Preparation of anhydride double-terminated polyimide resin

[0187] The difference between the present invention and Example 1 is that: the "1.55 g of 3,5-diaminobenzoic acid and 20 g of N-methylpyrrolidone solution" in step 11 is replaced by "1.55 g of 3,4-diaminobenzoic acid and 20 g of N-methylpyrrolidone solution", and the "2.04 g of 4,4'-diaminodiphenyl ether and 20 g of N-methylpyrrolidone solution" in step (2) is replaced by "5.29 g of 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane and 40 g of N-methylpyrrolidone solution" to prepare an anhydride double-terminated polyimide resin (No. PI-4) with a number average molecular weight of 7000 g / mol to 10000 g / mol.

[0188] (3) Preparation of photosensitive resin composition

[0189] The difference between the embodiment 1 and the embodiment 1 is that the polyimide resin with acid anhydride double end-capping is PI-4.

[0190] Example 5

[0191] The difference between this embodiment and Example 2 is that: (3) during the preparation of the photosensitive resin composition, PI-2 is 0.95 g.

[0192] Example 6

[0193] The difference between this embodiment and Example 2 is that: (3) during the preparation of the photosensitive resin composition, PI-2 is 2.85 g.

[0194] Example 7

[0195] The difference between it and Example 1 is that:

[0196] (2) Preparation of alkali-soluble photosensitive resin (alkali-soluble photosensitive resin-2)

[0197] Step 21: Add 350 g of bisphenol F epoxy resin EXA-7376 and 195 g of diethylene glycol methyl ether acetate into a four-necked flask at room temperature, stir under a nitrogen atmosphere, insert a thermocouple probe of a thermometer into the solution, and slowly raise the temperature to 90°C.

[0198] Step 22: After the bisphenol F epoxy resin EXA-7376 is completely dissolved, add 0.5 g of hydroquinone and raise the temperature to 110° C. When the system temperature stabilizes, slowly drop 72 g of acrylic acid and 1 g of triphenylphosphine using a constant pressure dropping funnel.

[0199] (3) Preparation of photosensitive resin composition: The alkali-soluble photosensitive resin is alkali-soluble photosensitive resin-2.

[0200] Example 8

[0201] The difference between it and Example 1 is that:

[0202] (2) Preparation of alkali-soluble photosensitive resin (alkali-soluble photosensitive resin-3)

[0203] Step 21: Add 210 g of o-cresol epoxy resin SQCN704M and 195 g of diethylene glycol methyl ether acetate into a four-necked flask at room temperature, stir under a nitrogen atmosphere, insert a thermocouple probe of a thermometer into the solution, and slowly raise the temperature to 90°C.

[0204] Step 22: After the o-cresol-formaldehyde epoxy resin SQCN704M is completely dissolved, add 0.5 g of hydroquinone and raise the temperature to 110°C. When the system temperature stabilizes, slowly add 72 g of acrylic acid and 1 g of triphenylphosphine using a constant pressure dropping funnel.

[0205] (3) Preparation of photosensitive resin composition: The alkali-soluble photosensitive resin is alkali-soluble photosensitive resin-3.

[0206] Example 9

[0207] The difference between this embodiment and Example 1 is that: (3) in the preparation of the photosensitive resin composition, the diethylene glycol methyl ether acetate in step 31 and step 32 is replaced by diethylene glycol ethyl ether acetate.

[0208] Example 10

[0209] The difference between the embodiment 1 and the embodiment 1 is that: (3) in the preparation of the photosensitive resin composition, the diethylene glycol methyl ether acetate in step 31 and step 32 is replaced by diethylene glycol butyl ether acetate.

[0210] Embodiment 11

[0211] The difference between it and Example 1 is that:

[0212] (1) Preparation of anhydride double-terminated polyimide resin

[0213] The difference between it and Example 1 is that the "15.93 g of 4,4'-(4,4'-isopropyldiphenyloxy)phthalic anhydride and 140 g of N-methylpyrrolidone solution" in step 13 is replaced by "11.68 g of 4,4'-(4,4'-isopropyldiphenyloxy)phthalic anhydride and 100 g of N-methylpyrrolidone solution" to prepare anhydride double-terminated polyimide resin (No. PI-5) with a number average molecular weight of 13000 g / mol to 15000 g / mol.

[0214] (3) Preparation of photosensitive resin composition

[0215] The difference between the embodiment 1 and the embodiment 1 is that the polyimide resin with acid anhydride double end-capping is PI-5. During the preparation process, since PI-5 cannot be completely dissolved in diethylene glycol methyl ether acetate, the experiment was terminated.

[0216] Comparative Example 1

[0217] The difference between this embodiment and Example 1 is that: (3) PI-1 is not added during the preparation of the photosensitive resin composition.

[0218] Comparative Example 2

[0219] The difference between it and Example 6 is that: (1) in the preparation of the anhydride double-terminated polyimide resin, the "2.04 g of 4,4'-diaminodiphenyl ether and 20 g of N-methylpyrrolidone solution" in step 12 is replaced by "5.29 g of 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane and 40 g of N-methylpyrrolidone solution", and the "15.93 g of 4,4'-(4,4'-isopropyldiphenyloxy)diphthalic anhydride and 140 g of N-methylpyrrolidone solution" in step (3) is replaced by "21.24 g of 4,4'-(4,4'-isopropyldiphenyloxy)diphthalic anhydride and 185 g of N-methylpyrrolidone solution" to prepare an anhydride double-terminated polyimide resin (No. PI-D1) with a number average molecular weight of 3000 g / mol to 4500 g / mol.

[0220] (3) Preparation of photosensitive resin composition: PI-D1 was used to replace PI-1 in Example 6.

[0221] Comparative Example 3

[0222] The difference between the above-mentioned embodiment and Example 1 is as follows: (1) Preparation of polyimide: Under a dry nitrogen flow, firstly, 1.56 g (4.25 mmol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6-FAP-ATA) was dissolved in 8 g of 1,4-butyrolactone, then 3.12 g (10 mmol) of bis(3,4-dicarboxyphenyl)ether dianhydride (OPDA) was added, and then 2 g of 1,4-butyrolactone was added, and the mixture was reacted at 60° C. for 30 min, then 0.94 g (2.1 mmol) of polypropylene glycol 400 (PPG400) was added, and the mixture was reacted at 60° C. for 30 min, then 1.56 g (4.25 mmol) of 6-FAP-ATA was added, and the mixture was reacted at 60° C. for 30 min, and finally 0.33 g (3 mmol) of end-capping agent 4-aminophenol was added and the mixture was reacted for 30 min. The mixture was then stirred at 180° C. for 4 h to obtain an amber weakly alkaline water-soluble polyimide resin (PI-D2) having an alkoxy oligomer content of 12 wt %.

[0223] (3) Preparation of photosensitive resin composition: PI-D2 was used to replace PI-1 in Example 1. During the preparation process, since PI-D2 could not be completely dissolved in diethylene glycol methyl ether acetate, the experiment was terminated.

[0224] Comparative Example 4

[0225] The difference between this embodiment and Example 2 is that: (3) during the preparation of the photosensitive resin composition, PI-2 is 4.0 g.

[0226] Comparative Example 5

[0227] The difference between it and Example 6 is that: (1) the "2.04 g of 4,4'-diaminodiphenyl ether and 20 g of N-methylpyrrolidone solution" in step 12 is replaced by "5.29 g of 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane and 40 g of N-methylpyrrolidone solution", and the "15.93 g of 4,4'-(4,4'-isopropyldiphenyloxy)phthalic anhydride and 140 g of N-methylpyrrolidone solution" in step (3) is replaced by "11.68 g of 4,4'-(4,4'-isopropyldiphenyloxy)phthalic anhydride and 120 g of N-methylpyrrolidone solution" to prepare anhydride double-terminated polyimide resin (No. PI-D3) with a number average molecular weight of 13000 g / mol to 15000 g / mol.

[0228] The difference between the embodiment 1 and the embodiment 6 is that the polyimide resin with double end-capping of anhydride is PI-D3.

[0229] Solubility test

[0230] 10 mg of the prepared anhydride double-terminated polyimide resin (PI-1 to PI-5, PI-D1 to PI-D3) was added to 1 ml of solvent and allowed to stand for 24 hours to observe whether it was completely dissolved. The test results are shown in Table 1.

[0231] Table 1 Solubility of soluble polyimide

[0232] PI-1 PI-2 PI-3 PI-4 PI-5 PI-D1 PI-D2 PI-D3 NMP ++ ++ ++ ++ ++ ++ ++ ++ DMF ++ ++ ++ ++ ++ ++ ++ ++ DMAc ++ ++ ++ ++ ++ ++ ++ ++ DMSO ++ ++ ++ ++ ++ ++ ++ ++ THF ++ ++ ++ ++ ++ ++ ++ ++ γ-Butyrolactone ++ ++ ++ ++ ++ ++ ++ ++ Carbitol acetate +- ++ +- ++ -- ++ -- +-

[0233] Note: The symbol ++ indicates solubility at room temperature; the symbol +- indicates solubility upon heating; the symbol - indicates insolubility.

[0234] As shown in Table 1, PI-1 to PI-5 prepared in the examples of the present application can be dissolved in NMP, DMF, DMAc, DMSO, THF and γ-butyrolactone, and can also be dissolved in carbitol acetate, so that the photosensitive resin composition in the present application can use carbitol acetate as a solvent. In addition, after increasing the proportion of dianhydride monomers, the molecular weight of polyimide is reduced and the solubility is improved. At the same time, after introducing a more flexible structure into the main structure of polyimide, the solubility of polyimide is further improved.

[0235] In addition, 100 parts by mass of alkali-soluble photosensitive resin (alkali-soluble photosensitive resin-1) and 20 parts by mass of PI-1 were added to 30 parts by mass of carbitol acetate to prepare a resin glue solution. The resin glue solution was stirred for 0.5 hours and then allowed to stand for 24 hours. The solubility of alkali-soluble photosensitive resin-1 and PI-1 in carbitol acetate was observed under a microscope. The test results are as follows: Figure 1 As shown in the test results, it can be seen that both alkali-soluble photosensitive resin-1 and PI-1 can be dissolved in carbitol acetate.

[0236] Mechanical properties test

[0237] The photosensitive resin composition prepared in each embodiment and comparative example was coated on a PET film by a coating method to prepare a wet film with a thickness of about 25 microns, soft-baked at 80°C for 25 minutes, exposed by a UV exposure machine for 30 seconds, and then thermally cured at 170°C for 1 hour to obtain a dry film, which was then cut into rectangular strips with a length of 15 mm and a width of 3 mm. The mechanical properties of the prepared film were characterized by a DMA850 dynamic thermomechanical analyzer (DMA) of TA Instruments, USA. During the test, the gauge length was set to 10 mm, the strip was clamped on the DMA fixture, the average thickness value of the strip was input, the stretching rate was set to 1 N / min, the test temperature was room temperature, and the stress-strain data of the strip from the beginning of stretching to the time of fracture were obtained. The test results are shown in Table 2.

[0238] Heat resistance test

[0239] The photosensitive resin compositions prepared in the examples and comparative examples were tested for thermal properties of the films by TMA450 thermomechanical analyzer of TA Instruments, USA. The gauge length was set to 10 mm during the test, and the temperature program was set to increase from 25°C to 270°C at a heating rate of 5°C / min, then lowered to room temperature, and then increased from 25°C to 270°C at a heating rate of 5°C / min, and the size-temperature curves of the samples during the two heating processes were recorded. The test results are shown in Table 2.

[0240] Table 2

[0241]

[0242]

[0243] It can be seen from the test results of Examples 1 to 10 and Comparative Examples 1 to 4 in Table 2 that adding a specific content and molecular weight of anhydride double-terminated polyimide resin to the photosensitive resin composition in the embodiments of the present application is beneficial to improving the heat resistance and flexibility of the cured product.

[0244] It can be seen from the test results of Examples 1 to 4 that the prepared PI-2 and PI-4 have better solubility in carbitol acetate and can also be dissolved in carbitol acetate at room temperature. The photosensitive dry film obtained by curing the photosensitive resin composition prepared therefrom has better heat resistance and flexibility, and its elongation at break can reach 1.52%, and the glass transition temperature can reach 175.7°C.

[0245] It can be seen from Example 2, Example 5, Example 6 and Comparative Example 5 that when the number average molecular weight of the added anhydride di-terminated polyimide resin is between 7000 g / mol and 10000 g / mol, and the added mass fraction is about 15 parts, the heat resistance and flexibility of the photosensitive dry film obtained by curing the photosensitive resin composition prepared therefrom are significantly improved.

[0246] It can be seen from the test results of Example 7 and Example 8 that when the added anhydride di-terminated polyimide resin is excessive (for example, more than 20%), the resin matrix in the photosensitive dry film obtained by curing the photosensitive resin composition prepared therefrom will produce phase separation. Although its flexibility is improved to a certain extent, its heat resistance is reduced to a certain extent.

[0247] The technical solutions provided by the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A photosensitive resin composition, characterized in that: Calculated by mass, including: 100 parts of alkali soluble photosensitive resin; 0.5 to 20 parts of anhydride double-terminated polyimide resin; and solvents; The number average molecular weight of the anhydride double-terminated polyimide resin is 5000 g / mol to 15000 g / mol, the alkali-soluble photosensitive resin and the anhydride double-terminated polyimide resin can be dissolved in the solvent, and the solid content of the photosensitive resin composition is 40% to 85%.

2. The photosensitive resin composition according to claim 1, characterized in that Calculated by mass, the photosensitive resin composition further includes a thermosetting resin and a curing agent, wherein the thermosetting resin is 15 to 45 parts, and the curing agent is 2 to 10 parts; and / or The number average molecular weight of the anhydride double-terminated polyimide resin is 5000 g / mol to 12000 g / mol; and / or The photosensitive resin composition further comprises a photopolymerizable monomer, wherein the photopolymerizable monomer is 5 to 15 parts; and / or The photosensitive resin composition further comprises a photopolymerization initiator, wherein the photopolymerization initiator is 0.5 to 2 parts; and / or The photosensitive resin composition further comprises at least one of an inorganic filler, a pigment, and an additive; and / or The solvent comprises at least one of an ether solvent, an ester solvent, a ketone solvent, an aromatic solvent and a petroleum solvent; and / or The alkali-soluble photosensitive resin includes a multifunctional epoxy resin containing a photosensitive group and an alkali-soluble group on the molecular chain; and / or The mass fraction of the anhydride double-terminated polyimide resin in the photosensitive resin composition is 10 to 16 parts; and / or The number average molecular weight of the anhydride double-terminated polyimide resin is 7000 g / mol to 10000 g / mol; and / or The anhydride double-terminated polyimide resin comprises dianhydride units and diamine units, wherein the diamine units comprise carboxyl-containing diamine units and non-carboxyl-containing diamine units; and the molar ratio of the carboxyl-containing diamine units to the non-carboxyl-containing diamine units is 1:

1.

3. The photosensitive resin composition according to claim 2, characterized in that: The photosensitive group comprises at least one of a carbon-carbon double bond, a carbonyl group and a peroxide group; and / or The alkali-soluble group comprises at least one of a carboxyl group, anhydride group and an ester group; and / or The acid value of the alkali-soluble photosensitive resin is 40 mg KOH / g to 200 mg KOH / g; and / or The number average molecular weight of the alkali-soluble photosensitive resin is 7000 g / mol to 9000 g / mol.

4. The photosensitive resin composition according to any one of claims 2 to 3, characterized in that: The structural unit of the anhydride double-terminated polyimide resin comprises at least one of an ether bond, a trifluoromethyl group and a macromolecular side group; and / or The photopolymerizable monomer comprises at least one of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, methyl (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 1,6-hexanediol di(meth)acrylate, lauryl (meth)acrylate, dipropylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, neopentyl glycol diethoxy / propoxy di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and polydipentaerythritol hexa(meth)acrylate; and / or The photopolymerization initiator includes at least one of photopolymerization initiator 907, oxime ester photopolymerization initiator, acylphosphine oxide photopolymerization initiator, acetophenone photopolymerization initiator, benzoin and its alkyl ether photopolymerization initiator, anthraquinone photopolymerization initiator, thioxanthone photopolymerization initiator, ketal photopolymerization initiator, and benzophenone photopolymerization initiator; and / or The thermosetting resin comprises at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, biphenyl phenol epoxy resin, biphenol epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol A epoxy resin, brominated bisphenol A epoxy resin, novolac epoxy resin, trisphenol methane epoxy resin, N-glycidyl epoxy resin, triglycidyl isocyanurate, cresol soluble epoxy resin, 2,6-xylenol dimer diglycidyl ether, alicyclic epoxy resin and xylene epoxy resin; and / or The curing agent includes at least one of dicyandiamide, melamine, diethylenetriamine, triethanolamine, polyamide, vinylamine, ethyl carbamate, methyl epoxyamine, and ethylphenylenediamine.

5. The photosensitive resin composition according to claim 2, characterized in that: The mass fraction of the inorganic filler in the photosensitive resin composition is 10 to 80 parts; and / or The inorganic filler comprises at least one of barium sulfate, silicon dioxide, calcium oxide, barium titanate, magnesium carbonate, calcium carbonate, talc, aluminum oxide, aluminum hydroxide, titanium oxide, fumed silica, clay, mica powder and kaolin; and / or The particle size of the inorganic filler is 0.001 μm to 20 μm; and / or The pigment comprises at least one of phthalocyanine green, phthalocyanine blue, titanium dioxide, carbon black and lithopone; and / or The additives include at least one of a curing accelerator, a photoinitiator aid, a diluent, a thixotropic tackifier, a leveling agent, an inhibitor, a tackifier, a defoamer, a coupling agent, an antioxidant and a rust inhibitor; and / or The mass fraction of the additive in the photosensitive resin composition is 0.05 parts to 20 parts.

6. The photosensitive resin composition according to claim 2, characterized in that: The ether solvent includes at least one of ethylene glycol ethyl ether, ethylene glycol butyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol ethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, propylene glycol monobutyl ether and dipropylene glycol monobutyl ether; and / or The ester solvent includes at least one of ethyl acetate, butyl acetate and carbitol acetate; and / or The ketone solvent includes at least one of cyclohexanone, butanone and isophorone; and / or The aromatic solvent comprises at least one of toluene, xylene and tetramethylbenzene; and / or The petroleum solvent includes naphtha; and / or The diamine unit comprises at least one of 3,5-diaminobenzoic acid, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxybenzene)]hexafluoropropane, and 3,4-diaminobenzoic acid; and / or The dianhydride unit includes 4,4'-(4,4'-isopropyldiphenoxy) diphthalic anhydride.

7. The photosensitive resin composition according to claim 6, characterized in that: The solvent is carbitol acetate.

8. A method for preparing a photosensitive resin composition, characterized in that: The preparation method comprises the following steps: Prepare a transparent mixed glue solution, wherein the mixed glue solution comprises anhydride double-terminated polyimide resin, an alkali-soluble photosensitive resin and a solvent; A thermosetting resin, a photopolymerizable monomer, a photopolymerization initiator and a curing agent are added to the mixed adhesive to obtain the photosensitive resin composition.

9. The method for preparing the photosensitive resin composition according to claim 8, characterized in that: The step of preparing the mixed glue solution comprises: Preparation of the anhydride double-terminated polyimide resin and / or preparation of the alkali-soluble photosensitive resin; wherein, The steps of preparing the anhydride double-terminated polyimide resin include: subjecting a dianhydride monomer and a diamine monomer to a condensation reaction in a solvent to obtain a polyamic acid solution, wherein the molar ratio of the dianhydride monomer to the diamine monomer is 2 to 4:1; subjecting the polyamic acid solution to imidization to obtain a polyimide; The step of preparing the alkali-soluble photosensitive resin comprises: subjecting a multifunctional epoxy compound and an unsaturated carboxylic acid to an esterification reaction to obtain an ester, and then reacting the obtained ester with a polyacid anhydride to obtain the alkali-soluble photosensitive resin.

10. A photosensitive dry film, characterized in that: The photosensitive dry film is obtained by curing a photosensitive resin composition prepared by the photosensitive resin composition according to any one of claims 1 to 7 or the method for preparing a photosensitive resin composition according to claim 8 or 9.

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