Photosensitive resin composition containing anthracene methyl sulfate quaternary ammonium salt photosensitizer and application thereof

Abstract

The invention provides a photosensitive resin composition containing an anthracene methyl sulfate quaternary ammonium salt photosensitizer and application of the photosensitive resin composition, and the photosensitizer is anthracene-9-methylene sulfate quaternary ammonium salt as shown in a formula (I) or anthracene-9, 10-dimethylene sulfate diquaternary ammonium salt as shown in a formula (II). Compared with a commercially available anthracene photosensitizer, the photosensitizer used by the invention can effectively avoid carbon-oxygen bond breakage caused by p-pi conjugation, so that migration of small molecular fragments after initiation is remarkably reduced, permeable crystallization to a polyethylene protective film is effectively inhibited, and the risk of short circuit of a line is reduced; due to the introduction of the sulfate quaternary ammonium salt, excellent fat solubility is ensured, and good formula compatibility is achieved; the special water solubility is realized, and the development waste in the later development process can be effectively reduced; more flexible selectivity is provided for the formula design of the photosensitive composition; the photosensitizer can be widely applied to the photocuring fields of dry films, paints, coatings, printing ink, forming materials and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of photosensitive resin, and particularly relates to a photosensitive resin composition containing anthracene methyl sulfate quaternary ammonium salt photosensitizer and application thereof. BACKGROUND

[0002] The photosensitive resin composition is widely used in the field of printed circuit board (PCB), lead frame (LF) and semiconductor packaging (IC) substrate printed circuit board manufacturing as a key pattern transfer material. Among them, the photosensitive resin composition is usually coated on the surface of a PET support film, and after drying, a protective layer such as a polyethylene film (PE) protective layer is closely attached to the surface to form a photosensitive dry film (or dry film resist). In the process of realizing pattern transfer, first, the dry film resist is attached to the copper substrate, a mask with a certain pattern is covered on the dry film resist, and pattern exposure is performed; then, a weak alkaline aqueous solution is used as a developing solution to remove the unexposed part, and etching or electroplating treatment is performed to form a pattern; finally, the dry film solidified part is removed by stripping with a film stripping solution, thereby realizing pattern transfer.

[0003] With the development of electronic devices towards miniaturization and high density, the fineness of the circuit is continuously improved. In order to meet the needs of fine line manufacturing, the photosensitive resin composition needs to have higher resolution. In order to improve the resolution, a suitable sensitizer needs to be added to the photosensitive resin composition. For the photosensitive resin composition, a suitable photoinitiating system has a direct influence on photosensitivity, resolution and production yield.

[0004] At present, small molecule anthracene derivatives represented by 9,10-dibutoxyanthracene (DBA), 9,10-diacetoxyanthracene (DAcOA) and 9,10-diphenylanthracene (DPHA) are widely used as photosensitizers. Generally, in order to obtain higher photosensitivity and resolution, such photosensitizers need to be used in combination with 2,4,5-triaryl imidazole dimer (HABI) (such as patent CN101568883B); however, such photosensitizer / photoinitiator combination system usually faces the following problems:

[0005] 1) Short-chain alkoxy anthracene derivatives (similar to DBA) with good solubility, due to their initiation mechanism, the fragments after initiation are easy to migrate in the dry film, penetrate to the surface of the polyethylene (PE) protective film to form crystals, thereby causing short circuit, open circuit and other defects of the resist pattern, or causing the risk of photosensitivity decline due to the penetration of photosensitizer from the photosensitive layer;

[0006] 2) 9,10-dioxyacyl anthracene photosensitizer (DAcOA) due to the electron-withdrawing induction effect of acyloxy group, resulting in the increase of electron cloud density of anthracene ring 9,10, so that the efficiency of such photosensitizer in catalytic curing reaction is reduced, the verticality of the sidewall of the cured photosensitive resin composition is poor, and the length difference between the top and bottom lines is large to form "inverted trapezoid" problem, and the energy required for such light initiator to be exposed is increased, and the photobleaching efficiency is reduced;

[0007] 3) DPHA has the advantage of high light quantum yield, but due to the too large conjugated system and high rigidity of the molecule, the solubility is poor;

[0008] 4) DBA, DAcOA and DPHA and other anthracene photosensitizers are all liposoluble small organic molecule compounds, which are not water-soluble. The direct consequence is that the liposoluble photosensitizer and its fragments are easy to aggregate and produce precipitates in the developing process, which are easy to adhere to the surface of the copper plate, causing problems such as residual copper or short circuit, which affect the product yield.

[0009] Therefore, it is a technical problem to be solved in the art to develop a new light initiation system with good liposolubility and water solubility, low migration, photobleaching characteristics and excellent developing compatibility, and to construct a high-performance photo-curable resin composition based on it. SUMMARY

[0010] Therefore, the purpose of the present application is to overcome the above-mentioned defects existing in the prior art, and to provide an anthracene photosensitizer with good liposolubility and water solubility, low migration, small electroplating pollution, a photosensitive resin composition and its application.

[0011] The purpose is solved by the photosensitive resin composition comprising anthracene methylene sulfates quaternary ammonium salt photosensitizer according to the present application, the photosensitive resist and photosensitive dry film comprising the photosensitive resin composition and the application of the photosensitive dry film in printed circuit board, lead frame, semiconductor packaging substrate, solar cell and photo-curable ink. The present application can improve the compatibility of the existing dry film product, reduce the migration of initiator to PE film, and also can greatly reduce the generation of developing garbage and improve the product yield.

[0012] Through a large amount of literature research and experimental research, the present application finds the following problems and proposes an innovative improvement scheme:

[0013] Anthracene compounds or anthracene derivatives can undergo dimerization under the action of light, thus being photobleached. This feature effectively avoids the problem of excessive energy absorption by the upper photosensitizer during exposure, and promotes the bottom photosensitive resin composition to receive more light, so that the photosensitive resin composition can be uniformly cured during exposure, achieving better resolution. For example, patent CN101218538B discloses a 9,10-dialkoxy anthracene photosensitizer, CN110446976B discloses an alkoxy anthracene or phenyl anthracene photosensitizer, and CN116300313A discloses a 9,10-dialkoxy anthracene or 9,10-diphenyl anthracene photosensitizer. The above anthracene photosensitizers have good resolution and adhesion.

[0014] However, the present application finds that the 9,10-dialkoxy anthracene photosensitizer will break the 9,10 C-O bond during exposure, and the anthracene ring will dimerize, releasing small molecule alkoxy fragments. These small molecule fragments will migrate from the cured photosensitive resin composition to the plating solution during the subsequent plating process, causing pollution and affecting the life of the plating solution and the plating effect. The 9,10-dialkoxy anthracene (DAcOA) photosensitizer has an electron-withdrawing inductive effect due to the acyloxy group, which increases the electron cloud density of the 9,10 number of anthracene rings. Therefore, the efficiency of the photosensitizer in catalyzing the curing reaction is reduced, the verticality of the side wall of the cured photosensitive resin composition is poor, and the length difference between the top and bottom lines is large, forming an "inverted trapezoidal" problem. In addition, the energy required for exposure of this type of photoinitiator is increased, and the photobleaching efficiency is reduced. The 9,10-dialkoxy anthracene photosensitizer has a rigid molecular structure, which greatly reduces its solubility and has a great impact on the uniformity and consistency of the product.

[0015] In addition, the present application also finds that DBA, DAcOA and DPHA, etc. anthracene photosensitizers are all liposoluble small molecule organic photosensitizers, which cannot be dissolved in water. However, in most cases, the development process is usually carried out in an aqueous solution of Na2CO3, so the direct consequence is that the liposoluble photosensitizer and its fragments are easy to aggregate and produce precipitates in the aqueous developing solution during the development process, which adhere to the surface of the copper plate, causing problems such as copper residue or short circuit, and affecting the product yield.

[0016] Based on the above findings, the present application proposes an anthracene methylene quaternary ammonium sulfate photosensitizer and a photosensitive resin composition suitable therefor, to improve the compatibility and water solubility of the existing dry film product, reduce the migration of the initiator to the PE film, and also greatly reduce the generation of development waste, thereby improving the product yield.

[0017] (I) Photosensitive resin composition

[0018] A first aspect of the present invention provides a photosensitive resin composition, comprising the following components based on 100 parts by mass of the photosensitive resin composition: an alkali-soluble resin A: 50-65 parts; a photopolymerization monomer B: 35-50 parts, which is selected from a monomer containing an ethylenically unsaturated double bond; a photoinitiator C: 2-5 parts, which is selected from a bis-imidazole compound; and a photosensitizer D: 0.1-1 part, wherein the photosensitizer D is an anthracene-9-methylene sulfonic acid quaternary ammonium salt having a structure represented by Formula (I) and / or an anthracene-9,10-dimethylene sulfonic acid diquaternary ammonium salt having a structure represented by Formula (II):

[0019]

[0020] wherein R a , R b , R c , and R d in the Formula (I) and R e , R f , R g , R h , R o , R p , R q , and R r are each independently selected from hydrogen, C1-C6 alkyl, C6-C12 aryl-substituted C1-C6 alkyl, C3-C12 heteroaryl-substituted C1-C6 alkyl, and C1-C6 alkoxy-substituted C1-C6 alkyl;

[0021] wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 in the Formula (I) and the Formula (II) are each independently selected from hydrogen, C1-C6 alkyl, C6-C12 aryl-substituted C1-C6 alkyl, C3-C12 heteroaryl-substituted C1-C6 alkyl, C1-C6 alkoxy-substituted C1-C6 alkyl, C3-C6 cycloalkyl, and halogen; optionally, any two of R a , R b , R c , and R d in the moiety in the Formula (I) and the Formula (II) optionally form a 3-8 membered ring with the N therein; optionally, any two of R e , R f , R g , and R h in the moiety in the Formula (II) optionally form a 3-8 membered ring with the N therein.any two of R R o , R p , R q , and R r in the moiety

[0022] optionally form a 3-8 membered ring with the N therein.

[0023] The photopolymerizable resin composition is photocured by the following photoinitiating free radical polymerization mechanism: the anthracene-9-methylene quaternary ammonium sulfate salt of the structure of Formula (I) and / or the anthracene-9,10-dimethylene diquaternary ammonium sulfate salt of the structure of Formula (II) are excited by visible light to generate anthracene radicals, which initiate homolytic cleavage of the bis-imidazole compound to generate imidazole radicals, which activate the monomer containing an olefinically unsaturated double bond to crosslink and cure.

[0024] As used herein, the term "alkyl" includes saturated aliphatic hydrocarbons containing straight chain and branched chains. In some embodiments, alkyl groups have 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbon atoms. For example, the term "Ci-C6alkyl", and the alkyl portion of other groups mentioned herein (e.g., Ci-C6alkoxy), refers to a straight chain or branched chain hydrocarbon group monovalent radical having 1 to 6 carbon atoms (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, or n-hexyl).

[0025] As used herein, the term "cycloalkyl" includes saturated or unsaturated non-aromatic monocyclic or polycyclic (e.g., bicyclic) hydrocarbon rings (e.g., monocyclic such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like). The cycloalkyl group can have 3 to 6 carbon atoms.

[0026] As used herein, the term "aryl" can include all carbon monocyclic or fused ring polycyclic aromatic groups having a conjugated pi-electron system. Aryl groups have 6 or 12 carbon atoms in the ring(s). Most commonly, aryl groups have 6 carbon atoms in the ring. For example, as used herein, the term "C6-C12aryl" refers to aromatic groups containing 6 to 12 carbon atoms, such as phenyl or naphthyl.

[0027] As used herein, the term "heteroaryl" includes monocyclic or fused ring polycyclic aromatic heterocyclic groups having one or more heteroatom ring members (ring-forming atoms) independently selected from O, S, and N in at least one ring. Heteroaryl groups have from 5 to 14 ring-forming atoms, including from 1 to 13 carbon atoms, and from 1 to 8 heteroatoms selected from O, S, and N.

[0028] Alkali-soluble resin A

[0029] The photosensitive resin composition according to the present application, wherein the alkali-soluble resin is an acrylate copolymer containing an aromatic group. From the viewpoint of improving resolution and chemical resistance of the product, it is preferable that the copolymerization ratio of the comonomer having an aromatic group is 50-70% based on the total mass of the comonomers in the copolymerization process.

[0030] In some embodiments of the present application, the alkali-soluble resin is obtained by copolymerization of one or more of (meth)acrylic acid, alkyl (meth)acrylate, benzyl (meth)acrylate, benzyl (meth)acrylate derivative, phenyl (meth)acrylate, styrene, and styrene derivative.

[0031] In some embodiments of the present application, the alkali-soluble resin is obtained by copolymerization of (meth)acrylic acid and a comonomer unit selected from one or more of methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, hydroxyethyl (meth)acrylate, and styrene.

[0032] In some specific embodiments of the present application, the comonomers of the alkali-soluble resin include methacrylic acid, methyl methacrylate, hydroxyethyl methacrylate, benzyl methacrylate, and styrene.

[0033] Further, the alkali-soluble resin has a weight average molecular weight of 20,000-60,000, a resin acid value of 160-220 mg KOH / g, and a molecular weight distribution index of 1.0-3.0.

[0034] In embodiments of the present application, the content of the alkali-soluble resin is 50-65 parts by mass, preferably 55-60 parts by mass. If the content is less than 50 parts by mass, there is a tendency for the resist layer to flow, and if the content exceeds 65 parts by mass, there is a tendency for resolution to decrease.

[0035] Photopolymerization monomer B

[0036] According to the present application, there is provided a photosensitive resin composition, wherein the photopolymerization monomer is selected from the group consisting of monomers containing an ethylenically unsaturated double bond, preferably from the group consisting of ethylenically unsaturated carboxylic acids and / or ethylenically unsaturated carboxylic acid esters, and more preferably from the group consisting of (meth)acrylate monomers.

[0037] In a preferred embodiment of the present application, the photopolymerization monomer is selected from one or more of methoxypolyethylene glycol monoacrylate, ethoxy(propoxy) nonylphenol acrylate, ethoxy(propoxy) bisphenol A di(meth)acrylate, ethoxy(propoxy) di(meth)acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxy(propoxy) trimethylolpropane tri(meth)acrylate, di(trimethylolpropane) tetraacrylate, ethoxy(propoxy) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

[0038] In an embodiment of the present application, the content of the photopolymerization monomer is 35 to 50 parts by mass, preferably 40 to 50 parts by mass, and more preferably 45 to 50 parts by mass. If the content is less than 35 parts by mass, there is a tendency for the sensitivity and the resistance of the resist to decrease, and if the content exceeds 50 parts by mass, there is a tendency for the photosensitive resin composition to be difficult to filmize and for the resist layer to flow.

[0039] Photoinitiator C

[0040] According to the present application, there is provided a photosensitive resin composition, wherein the photoinitiator can be selected from the group consisting of bisimidazole compounds, and preferably from the group consisting of 2,4,5-triaryl imidazole dimers.

[0041] In a preferred embodiment of the present application, the photoinitiator is selected from one or more of 2-(2-chlorophenyl)-4,5-diphenyl imidazole dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl) imidazole dimer, 2-(2-fluorophenyl)-4,5-diphenyl imidazole dimer, 2-(2-methoxyphenyl)-4,5-diphenyl imidazole dimer, 2-(4-methoxyphenyl)-4,5-diphenyl imidazole dimer, 2,2',4-tri(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-biimidazole.

[0042] In an embodiment of the present application, the content of the photoinitiator is 2 to 5 parts by mass, preferably 2 to 4 parts by mass, and more preferably 2.5 to 3.5 parts by mass. If the content is less than 2 parts by mass, there is a tendency for the sensitivity and the resolution of the resist to decrease, and if the content exceeds 5 parts by mass, there is a tendency for the amount of development waste to increase.

[0043] Photosensitizer D

[0044] According to the present application, there is provided a photosensitive resin composition, wherein the photosensitizer is anthracene-9-methylene sulfonic acid quaternary ammonium salt having a structure represented by formula (I) and / or anthracene-9,10-dimethylene sulfonic acid diquaternary ammonium salt having a structure represented by formula (II):

[0045] ,

[0046] R a , R b , R c , and R d in the formula (I), R e , R f , R g , R h , R o , R p , R q , and R r in the formula (II), and R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 in the formula (I) and the formula (II) are each independently selected from hydrogen and C1-C6 alkyl, and preferably, each independently selected from C1-C6 alkyl.

[0047] In some embodiments according to the present application, R a , R b , R c , and R d in the formula (I), and R e , R f , R g , R h , R o , R p , R q , and R r in the formula (II) are each independently selected from hydrogen and C1-C6 alkyl, and preferably, each independently selected from C1-C6 alkyl.

[0048] In some embodiments according to the present application, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9each independently selected from the group consisting of hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, and halogen, more preferably each independently is hydrogen.

[0049] As can be seen from the above structural formulae, in the anthracene-9-methylene sulfate quaternary ammonium salt of structure (I) and the anthracene-9,10-dimethylene sulfate diquaternary ammonium salt of structure (II), a sulfate-substituted methylene group is introduced at the 9-position and / or the 10-position of anthracene, and the counter ion is a positive quaternary ammonium salt cation. Compared with existing anthracene photosensitizers, the introduction of the anion-cation pair ensures the water solubility of the structure; at the same time, due to the presence of the quaternary ammonium salt ion containing an alkyl group, the liposolubility of the ion compound is also ensured. In addition, compared with existing DBA photosensitizers, no small molecule fragments are generated, and the compounds can be widely applied in the fields of dry films, paints, coatings, inks, and molding materials.

[0050] In a preferred embodiment of the present application, the photosensitizer is selected from one or more of anthracene-9-methylene sulfate mono-tetra-n-butyl quaternary ammonium salt (TM1) and anthracene-9,10-dimethylene sulfate di-tetra-n-butyl quaternary ammonium salt (TM2).

[0051] In some specific embodiments of the present application, the photosensitizer can have one of the following structures:

[0052] .

[0053] In an embodiment of the present application, the content of the photosensitizer is 0.1-1 parts by mass, preferably 0.1-0.8 parts by mass, and more preferably 0.2-0.5 parts by mass. If the content is less than 0.1 parts by mass, the sensitivity of the resist tends to decrease, and if the content exceeds 1 part by mass, the lower layer of the resist tends to be incompletely cured, resulting in a "reversed trapezoidal" cross-sectional shape of the resist and poor resolution.

[0054] The preparation strategy of the anthracene-9-methylene sulfate quaternary ammonium salt of structure (I) and the anthracene-9,10-dimethylene sulfate diquaternary ammonium salt of structure (II) can be universally derived through the typical synthetic path of the examples. Based on the conventional principles of organic synthesis and the specific preparation steps of compounds TM1 and TM2 in the examples, a person skilled in the art can clearly understand the general preparation logic of the anthracene-methylene sulfate quaternary ammonium salt photosensitizer. A person skilled in the art can derive the preparation method of all anthracene-methylene sulfate quaternary ammonium salt photosensitizers of structures (I) and / or (II) by replacing anthracene-9-acetic acid or anthracene-9,10-diacetic acid containing different substituents on the anthracene ring, the type of ammonium bisulfate, and optimizing the reaction parameters.

[0055] The anthracene methylene quaternary ammonium sulfate photosensitizer of the present application can be prepared by conventional synthesis methods in the art. For example, it is prepared according to the decarboxylation mechanism described in the literature (such as Organic Letters, 2024, 26(27), 5856-5861).

[0056] A typical reaction operation is as follows: under a nitrogen atmosphere, a round-bottom flask equipped with a magnetic stirrer is charged with anthracene acetic acid and ammonium persulfate salt, and a catalytic amount of silver nitrate and 4,7-diphenyl-1,10-phenanthroline, and KH2PO4 and tetraalkylammonium hydrogen sulfate are added, dissolved in dichloromethane and reacted at room temperature. After the reaction is completed by thin layer chromatography (TLC), the reaction system is washed with saturated brine, the organic phase is collected, dried over anhydrous sodium sulfate and purified by column chromatography, and the yield can generally reach 80%-90%.

[0057] Additive E

[0058] In various embodiments of the present application, the photosensitive resin composition can also contain one or more additives selected from dyes, photo-developers, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, and coating aids, as needed. Preferably, the total amount of the additives is 0.5-5.0 parts by mass.

[0059] (II) Photosensitive dry film

[0060] The second aspect of the present application provides a photosensitive dry film, which comprises, from bottom to top: a support layer; a photosensitive resist layer attached to the surface of the support layer; and a protective layer attached to the surface of the photosensitive resist layer, wherein the photosensitive resist layer is formed from the photosensitive resin composition provided in the first aspect of the present application.

[0061] In some preferred embodiments of the present application, the photosensitive dry film comprises, from bottom to top: a PET support layer; a photosensitive resist layer formed by coating and drying the photosensitive resin composition provided in the first aspect of the present application on the surface of the PET support layer; and a PE protective layer.

[0062] (III) Application of photosensitive dry film

[0063] The third aspect of the present application provides the application of the above-mentioned photosensitive dry film in printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocured inks, etc.

[0064] The anthracene methylene quaternary ammonium sulfate compound of formula (I) and / or formula (II) with sulfate substitution introduced at position 9 and / or position 10 used as photosensitizer in the present application has significant advantages compared to existing DBA photosensitizers:

[0065] (1) By introducing the methylene group replaced by sulfate, the maximum absorption wavelength is red-shifted while the electron cloud density of the condensed ring aromatic hydrocarbon is maintained, which is especially suitable for 405nm light system, improves the photosensitivity, and more efficiently utilizes the energy of the exposure light source, thereby greatly improving the production efficiency;

[0066] (2) At the same time, the problem of alkoxycarbonyl bond rupture caused by p-π conjugation of DBA is avoided, thereby significantly reducing the migration of small molecule fragments after initiation, effectively inhibiting the penetration and crystallization of the polyethylene protective film, and reducing the risk of short circuit of the circuit;

[0067] (3) Compared with the conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizer of the present application can ensure excellent solubility in conventional organic solvents such as monomers, good compatibility with the formula, and unique water solubility, which can effectively reduce the development waste in the later development process, without changing the maximum absorption wavelength and absorption intensity, and retaining excellent photobleaching performance. It provides more flexible options for the formula design of the photosensitive composition.

[0068] In addition to the above purposes, features and advantages, the present application also has other potential technical advantages, which provides a more optimal solution for the development of related fields.

[0069] In summary, the photosensitive dry film provided by the present application has excellent resolution and adhesion, and has higher photosensitivity than the photosensitive resin composition added with 9,10-dibutoxy anthracene photosensitizer, which is beneficial to improve the production efficiency of the client, meets the needs of high density and high fineness of the printed circuit board, and the excellent solubility in conventional organic solvents and excellent water solubility are extremely beneficial to the formula development of the photosensitive composition. BRIEF DESCRIPTION OF DRAWINGS

[0070] Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings, in which:

[0071] Figure 1 is the H NMR spectrum of the photosensitizer TM1 prepared in Example 1 of the present application 1 H NMR spectrum;

[0072] Figure 2 is the C NMR spectrum of the photosensitizer TM1 prepared in Example 1 of the present application 13 C NMR spectrum;

[0073] Figure 3 is the H NMR spectrum of the photosensitizer TM2 prepared in Example 2 of the present application 1 H NMR spectrum;

[0074] Figure 4 is the C NMR spectrum of the photosensitizer TM2 prepared in Example 2 of the present application 13 C NMR spectrum;​​​​​​​​​​​​​​​​​​​​​​​

[0075] Figure 5 is the UV absorption spectrum of photosensitizer TM1 prepared in Example 1 of the present application;

[0076] Figure 6 is the UV absorption spectrum of photosensitizer TM2 prepared in Example 2 of the present application;

[0077] Figure 7 is the photobleaching curve of photosensitizer TM1 prepared in Example 1 of the present application under 405 nm light irradiation;

[0078] Figure 8 is the photobleaching curve of photosensitizer TM2 prepared in Example 2 of the present application under 405 nm light irradiation. DETAILED DESCRIPTION

[0079] The present application will be further described in conjunction with the specific embodiments, and the examples given are only to illustrate the present application, but not to limit the scope of the present application.

[0080] Example 1

[0081] Preparation of anthracene-9-methylene sulfate monotetra-n-butyl quaternary ammonium salt (photosensitizer TM1)

[0082]

[0083] Under a nitrogen atmosphere, a round-bottom flask equipped with a magnetic stirrer was charged with the material anthracene-9-acetic acid (1.0 mmol), ammonium persulfate salt (3.0 mmol), AgNO3(0.05 mmol, 5 mol%), 4,7-diphenyl-1,10-phenanthroline (L: 0.05 mmol, 5 mol%), KH2PO4(1.2 mmol) and tetra-n-butylammonium hydrogen sulfate (1.2 mmol) were dissolved in dry dichloromethane (5 mL) solvent at the indicated molar ratio, stirred at room temperature for 12 hours until the reaction was completed by monitoring by TLC, i.e. the consumption of the starting material anthracene-9-acetic acid, the reaction system was washed with saturated brine, the organic phase was collected and dried over anhydrous sodium sulfate, and then purified by column chromatography (yield 85%).

[0084] The structural formula of the product anthracene-9-methylene sulfate monotetra-n-butyl quaternary ammonium salt (photosensitizer TM1) is as follows:

[0085]

[0086]

[0087] Example 2

[0088] Preparation of anthracene-9, 10-dimethylene bis tetra-n-butyl quaternary ammonium sulfate (photosensitizer TM2)

[0089]

[0090] Under nitrogen atmosphere, to a round bottom flask equipped with magnetic stirring, the material anthracene-9, 10-diacetic acid (1.0 mmol), ammonium persulfate salt (6.0 mmol), AgN03(0.0 mmol, 10 mol%), 4,7-diphenyl-1,10-phenanthroline (L: 0.1 mmol, 10 mol%), KH2P04(2.4 mmol) and tetra-n-butylammonium hydrogen sulfate (2.4 mmol) were dissolved in dry dichloromethane (7.5 mL) solvent in the molar ratios indicated, stirring at room temperature for 12 hours until the end of the reaction, monitored by TLC, i.e. until the consumption of the starting material anthracene-9, 10-diacetic acid, the reaction system was washed with saturated brine, the organic phase was collected and dried over anhydrous sodium sulfate and purified by column chromatography (yield 85%).

[0091] The product anthracene-9, 10-dimethylene bis tetra-n-butyl quaternary ammonium sulfate (photosensitizer TM2) has the following structural formula:

[0092]

[0093]

[0094] UV-Vis absorption spectrum and photobleaching experiments

[0095] The UV-Vis absorption spectrum was tested on a Shimadzu UV-1900 UV-Vis spectrophotometer, with toluene as the solvent, at a concentration of 4 x 10 -5 mol / L.

[0096] According to the Lambert-Beer law, the molar extinction coefficient is ε = A bn / c, where A bn is the absorbance of the UV-Vis absorption spectrum and c is the concentration.

[0097] Photobleaching experiments: the UV-Vis absorption spectrum of the sample solution was tested on a Shimadzu UV-1900 UV-Vis spectrophotometer, with toluene as the solvent, under a 450 nm LED.

[0098] Figure 5 is the UV absorption spectrum of photosensitizer TM1; Figure 6 is the UV absorption spectrum of photosensitizer TM2; Figure 7 and Figure 8The photobleaching curves of TM1 and TM2 under 405 nm light irradiation, respectively. The molar extinction coefficient results of photosensitizer TM1 and TM2 and DBA are shown in Table 1 as follows:

[0099]

[0100] From the comparison of the UV absorption spectra of Table 1, it can be seen that the photosensitizer of the present application has a molar extinction coefficient close to that of DBA; at the same time, from the comparison of the UV absorption spectra of Figures 5-8 It can be seen that the photosensitizers TM1 and TM2 of the present application have very good photobleaching performance, with photobleaching in 60 min and 90 min, respectively.

[0101] Solubility test

[0102] With acetone, toluene, methanol and water as solvents, a mixture of 5 g of methoxyl polyethylene glycol (350) monoacrylate, 20 g of 10 (ethoxyl) bisphenol A dimethacrylate, 5 g of 6 (propoxyl) bisphenol A dimethacrylate, 10 g of 3 (ethoxyl) trimethylolpropane triacrylate, 4 g of di (trimethylolpropane) tetraacrylate as monomers (denoted as "monomers" in the table), the solubility of photosensitizers TM1-TM2 of test examples 1-2 and DBA, DPHA and DAcOA in various solvents and their compatibility with monomers were tested, the solute was added to the solvent according to the proportion of 0.1 g solute / 1 g solvent (10% w / w), and the solubility was recorded according to the following grading standard, and the test results are shown in Table 2:

[0103] Good (fast dissolution): under room temperature and stirring conditions, within 1 minute, a clear and transparent uniform solution can be formed;

[0104] Medium (slow dissolution): under room temperature and stirring conditions, more than 5 minutes, a clear and transparent uniform solution can be formed; or under room temperature conditions, it cannot be completely dissolved, but when heated to 50-60℃, a clear and transparent uniform solution can be formed, and there is no obvious phenomenon of turbidity after the solution is cooled to room temperature;

[0105] Poor (partial dissolution): under room temperature and stirring conditions, more than 5 minutes, it cannot be completely dissolved; or when heated to 50-60℃, it can be completely dissolved, but it becomes obviously turbid after the solution is cooled to room temperature.

[0106]

[0107] As can be seen from the data in Table 2, compared with the conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizers TM1 and TM2 of the present application exhibit more excellent solubility in various commonly used organic solvents, good compatibility with monomers, and more uniquely, very excellent solubility in water, which is very helpful for the formulation design of the photocuring composition.

[0108] Examples 3-8 and Comparative Examples 1-7

[0109] Preparation of the photosensitive resin composition

[0110] Referring to the formulations shown in Table 3, the photosensitive resin compositions of the present application of Examples 3-8 were prepared, and at the same time, the photosensitive resin compositions of Comparative Examples 1-7 using the prior art photosensitizers were prepared for comparison. The specific preparation method is that the components corresponding to the sample numbers 3-8 and 1-7 in Table 3 are mixed uniformly, and the photosensitive resin composition can be prepared. In order to facilitate film coating, a solvent acetone can be added to adjust to an appropriate viscosity. Among them, blank means not added.

[0111]

[0112] The component explanations of the component codes in Table 3 are as follows:

[0113] A (alkali-soluble resin): acrylate copolymer, solution polymerization method, polymerization of methacrylic acid / butyl methacrylate / benzyl methacrylate = 25 / 10 / 65 by mass ratio; solvent is acetone, solid content is 46%, weight average molecular weight is 40000, dispersity is 2.1, acid value is 163 mgKOH / g. (Hunan Chuyuan New Material Co., Ltd.);

[0114] B (photopolymerization monomer) is composed of the following components (purchased from Shadoma Guangzhou Chemical Co., Ltd.): 5 g of methoxypolyethylene glycol (350) monoacrylate, 20 g of 10 (ethoxyl) bisphenol A dimethacrylate, 5 g of 6 (propoxy) bisphenol A dimethacrylate, 10 g of 3 (ethoxyl) trimethylolpropane triacrylate, 4 g of di (trimethylolpropane) tetraacrylate;

[0115] C (photoinitiator): 2,2'-bis (o-chlorophenyl)-4,4',5,5'-tetraphenyl-benzimidazole (BCIM) (purchased from Jiuding Chemical);

[0116] E (additive) is composed of the following components (purchased from Anjier Chemical): 0.5 g of leuco crystal violet, 0.05 g of malachite green, 0.8 g of p-toluenesulfonamide, 0.03 g of 2,6-di-tert-butyl-4-methylphenol;

[0117] The solvent consists of 8 g of acetone, 10 g of toluene, and 5 g of methanol.

[0118] Preparation of photosensitive dry film

[0119] The photosensitive resin compositions listed in Table 3 were subjected to photosensitive dry film preparation, including the following steps:

[0120] The photosensitive composition slurries prepared according to Table 3 were respectively coated on a 15 μm thick polyethylene terephthalate (PET) support film using a coating experiment device (model: AB4220, TQC, Netherlands); the solvent was removed at 80°C for 10 min, the photosensitive layer thickness after baking was controlled at 30 μm, and a polyethylene film (PE) was then overlaid for protection to obtain a photosensitive dry film.

[0121] Preparation of substrate with resist pattern

[0122] Substrates with resist patterns were prepared using the photosensitive compositions of inventive examples 3-8 and comparative examples 1-7 as shown in Table 3, with the following procedures:

[0123] (1) Photosensitive layer forming procedure: a photosensitive layer was formed on the substrate using the photosensitive composition;

[0124] (2) Exposure procedure: active light was irradiated to a part of the photosensitive layer to cause the irradiated part to be photocured and form a cured region;

[0125] (3) Development procedure: the part of the photosensitive layer other than the cured region was removed from the substrate to form a resist pattern on the substrate.

[0126] The operating conditions of each procedure are described in detail as follows.

[0127] Photosensitive layer forming procedure: a copper-clad laminate with a 35 μm thick rolled 1.2 mm thick copper foil was used, and after surface adjustment and preheating to 80°C, the PE protective film of the photosensitive dry film obtained from each example or comparative example was peeled off while the photosensitive resin composition layer was laminated on the copper-clad laminate using a hot roll laminator (Zhisheng Technology Co., Ltd., CSL-M25E) at a roll temperature of 110°C, an air pressure of 0.35 MPa, and a lamination speed of 1.5 m / min to obtain a test substrate.

[0128] Exposure procedure: exposure was performed using a direct drawing exposure machine (Xiaoge Micro, main wavelength 405 nm), and a Stouffer 41 level phase exposure ruler was used for photosensitivity testing, with the exposure grid number controlled at 14-18 grids.

[0129] Developing step: After exposure, the PET support film was peeled off, and an alkali developing machine (manufactured by Guangzhou Julong Printing Plate Equipment Co., Ltd., dry film developing machine) was used to spray a 1 wt% Na2CO3 aqueous solution at 30°C for 2 times the minimum developing time to dissolve and remove the unexposed part of the photosensitive resin layer. After development, the substrate was washed with pure water for 1.5 times the developing time, and then dehydrated using an air knife, and then warm air dried to obtain a substrate with an evaluation cured film. The shortest time required for complete dissolution of the photosensitive resin layer in the unexposed part was taken as the minimum developing time.

[0130] Evaluation items

[0131] 1. Sensitivity evaluation

[0132] A Stouffer 41-step exposure ruler was placed on the above-mentioned post-laminating test substrate to test the sensitivity. After the exposure process, the test substrate was left to stand for more than 20 min, and then the PET film layer was peeled off, and a 1.0 wt% sodium carbonate aqueous solution was sprayed at 30°C to remove the unexposed resist layer, and the developing time was 2.0 times the minimum developing time. After the above operation, a cured film obtained by curing the photosensitive resin composition was formed on the surface of the substrate. The exposure energy (mJ / cm 2 ) at which the number of remaining steps of the step exposure ruler obtained by the cured film was 16 steps was evaluated, and the smaller the value, the better the sensitivity of the photosensitive resin composition.

[0133] 2. Resolution evaluation

[0134] On the above-mentioned post-laminating test substrate, a photomask data having a line / space width of n:n (unit: μm) was used to expose at an energy that made the number of remaining steps of the Stouffer 41-step exposure ruler after development reach 16. After the developing process, the resist pattern was observed using an optical microscope, and the value of the smallest line width at which a complete cured resist line was formed was taken as the value of the adhesion (μm) to evaluate the adhesion. The smaller the value, the better the resolution.

[0135] 3. Dispersion stability evaluation

[0136] The above-mentioned prepared photosensitive dry film was stored in the dark at 25°C for 2 weeks. The surface of the photosensitive layer was observed using a microscope, and graded as follows:

[0137] ■ represents that the surface of the photosensitive layer is uniform;

[0138] X represents that the surface of the photosensitive layer precipitates undissolved substances.

[0139] 4. Migration evaluation

[0140] After the above prepared 3-layer structure of the photosensitive dry film is prepared, the ultraviolet absorption spectrum of the dry film is detected by a UV spectrophotometer to obtain the absorbance A1 of the maximum absorption peak in 350-450 nm; then the dry film is placed at 30°C for 72 hours, the PE film layer on the surface of the photosensitive dry film is removed, and the ultraviolet absorption spectrum of the PET layer and the photosensitive resist layer is detected by a UV spectrophotometer to obtain the absorbance A2 of the maximum absorption peak in 350-450 nm. If the sensitizer migrates to the surface of the PE layer, the absorbance of the maximum absorption peak of the PET layer and the photosensitive resist layer in the wavelength range of 350-450 nm will decrease, that is, the absorbance of the sensitizer migrated to the PE layer is (A1-A2). The migration degree of the photosensitizer, that is, the migration rate A = (A1-A2) / A1, is calculated, and the larger the value is, the greater the migration amount is.

[0141] The judgment basis is as follows:

[0142] O: migration rate A < 0.01;

[0143] X: migration rate A > 0.01.

[0144] The test results of evaluation items 1-4 are summarized in Table 4 below.

[0145] 5. Evaluation of development sediment

[0146] The photosensitive resin layer after drying is peeled off, and 18 g of the photosensitive layer resist is dissolved in 1 L of 1% Na2CO3 developing solution. After the photosensitive layer is completely dissolved, the solution is poured into a micro-developing machine, and after 60 minutes of spraying circulation at 30°C and 0.12 MPa pressure, the circulation is stopped. The developed solution after circulation is taken out and left to stand for 72 hours, and then the sediment is filtered out with ADVANTEC NO. 2 qualitative filter paper and dried to weigh, and the weight of the sediment on the filter paper is measured as a percentage of the initial 18 g of photosensitive layer w. Specifically, O represents 0≤w≤0.6%, Δ represents 0.6% < w≤0.8%, and X represents 0.8% < w;

[0147] The test results of evaluation items 1-5 are summarized in Table 4 below.

[0148]

[0149] The results in Table 4 show that, compared with the photosensitive resin composition of Comparative Examples 1-7, the photosensitive resin composition prepared using the photosensitizers TM1 and TM2 prepared in Examples 1 and 2 in Examples 3-8 of the present application can exhibit obvious advantages in dispersion stability, migration, and development waste amount, etc. under the premise of maintaining similar performance in photosensitivity and resolution within the addition range of 0.1-1.0; however, the performance has a significant decline when the addition amount is less than 0.1 or greater than 1.0.

[0150] The above results show that the photosensitizer of the present application has wide applicability, and has high photosensitivity and good formulation compatibility, can greatly reduce the developing waste, and has excellent formulation adaptability.

[0151] The above is only a preferred embodiment of the present application, not for limiting the present application. Those skilled in the art can make various modifications and changes within the spirit and principles of the present application, and any modification, equivalent replacement or improvement within the scope should be considered as covered by the protection scope of the present application.

Claims

1. A photosensitive resin composition, comprising the following components based on 100 parts by mass of the photosensitive resin composition: an alkali-soluble resin A: 50 to 65 parts; a photopolymerization monomer B: 35 to 50 parts, which is selected from the group consisting of monomers containing an ethylenically unsaturated double bond; a photoinitiator C: 2 to 5 parts, which is selected from the group consisting of bis-imidazole compounds; and a photosensitizer D: 0.1 to 1 part, wherein, the photosensitizer D is anthracene-9-methylene sulfonic acid monoquaternary ammonium salt having a structure represented by formula (I) and / or anthracene-9,10-dimethylene sulfonic acid diquaternary ammonium salt having a structure represented by formula (II): wherein R a , R b , R c and R d in the formula (I) and R e , R f , R g , R h , R o , R p , R q and R r in the formula (II) are each independently selected from the group consisting of hydrogen, C1-C6alkyl, C6-C12aryl-substituted C1-C6alkyl, C3-C12heteroaryl-substituted C1-C6alkyl and C1-C6alkoxy-substituted C1-C6alkyl; wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are each independently selected from the group consisting of hydrogen, Ci-C6alkyl, C6-Ci2aryl-substituted Ci-C6alkyl, C3-Ci2heteroaryl-substituted Ci-C6alkyl, Ci-C6alkoxy-substituted Ci-C6alkyl, C3-C6cycloalkyl, and halogen; Optionally, any two of R in the moiety a in the moiety b in the moiety c in the moiety d form a 3-8 membered ring with the N therein; optionally, any two of R in the moiety e in the moiety f in the moiety g in the moiety h form a 3-8 membered ring with the N therein; and optionally, any two of R in the moiety o in the moiety p in the moiety q in the moiety r form a 3-8 membered ring with the N therein.

2. The photosensitive resin composition according to claim 1, wherein: R a , R b , R c , and R d in the formula (I) and R e , R f , R g , R h , R o , R p , R q , and R r are each independently selected from the group consisting of hydrogen and Ci-C6alkyl; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , and R 9 in the formula (I) and formula (II) are each independently selected from the group consisting of hydrogen, Ci-C6alkyl, C3-C6cycloalkyl, and halogen.

3. The photosensitive resin composition according to claim 1, wherein the formula (I) has the following structure: the formula (II) has the following structure: 。 4. The photosensitive resin composition according to claim 1, wherein the content of the photosensitizer D is 0.1 to 0.8 parts by mass.

5. The photosensitive resin composition according to claim 1, wherein the alkali-soluble resin A is an acrylate copolymer containing an aromatic group; the copolymerization ratio of the comonomer having an aromatic group is 50 to 70% based on the total mass of the comonomers in the copolymerization process; the weight average molecular weight of the alkali-soluble resin is 20,000 to 60,000, the resin acid value is 160 to 220 mg KOH / g, and the molecular weight distribution index is 1.0 to 3.0; the photopolymerization monomer B is selected from one or more of methoxypolyethylene glycol monoacrylate, ethoxy(propoxy) nonylphenol acrylate, ethoxy(propoxy) bisphenol A di(meth)acrylate, ethoxy(propoxy) di(meth)acrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, ethoxy(propoxy) trimethylolpropane tri(meth)acrylate, di(trimethylolpropane) tetraacrylate, ethoxy(propoxy) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

6. The photosensitive resin composition according to claim 1, wherein the bis-imidazole compound as the photoinitiator C is selected from 2,4,5-triaryl imidazole dimer.

7. The photosensitive resin composition according to claim 1, wherein the bis-imidazole compound is selected from one or more of 2-(2-chlorophenyl)-4,5-diphenyl imidazole dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl) imidazole dimer, 2-(2-fluorophenyl)-4,5-diphenyl imidazole dimer, 2-(2-methoxyphenyl)-4,5-diphenyl imidazole dimer, 2-(4-methoxyphenyl)-4,5-diphenyl imidazole dimer, and 2,2',4-tri(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-biimidazole.

8. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition further comprises one or more additives E selected from the group consisting of dyes, photo-developing agents, plasticizers, adhesion promoters, polymerization inhibitors, defoaming agents, and coating aids; the total amount of the additives E is 0.5 to 5.0 parts by mass. 9.A photosensitive dry film, comprising from bottom to top: a support layer; a photosensitive resist layer attached to the surface of the support layer; and a protective layer attached to the surface of the photosensitive resist layer, wherein the photosensitive resist layer is formed using the photosensitive resin composition according to any one of claims 1 to 8. 10.Use of the photosensitive dry film according to claim 9 in printed circuit boards, lead frame, semiconductor package substrates, solar cells, and light-cured inks.

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