Anthracene methyl acetyl disulfide for a photosensitive resin composition and use thereof

Abstract

This invention provides anthracene methyl acetyl disulfide for use in photosensitive resin compositions, relating to the field of photopolymerization. The invention also includes a photosensitive resin composition containing the anthracene methyl acetyl disulfide, a photosensitive dry film containing the anthracene methyl acetyl disulfide, and their applications. The anthracene methyl acetyl disulfide of this invention is photosensitive and can be used as a photosensitizer in photosensitive resin compositions. It can also improve the adhesion of photosensitive resin compositions to various metal surfaces, exhibits low migration characteristics, and has good compatibility with monomers and solvents. It can be widely used in photocuring fields such as dry films, paints, coatings, inks, and molding materials; it has extremely high photobleaching efficiency and is particularly suitable for use in ultra-thick film formulations.

Description

Technical Field

[0001] This invention relates to the field of photopolymerization, and more specifically to an anthracene methyl acetyl disulfide for use in photosensitive resins and its applications. Background Technology

[0002] Pattern transfer technology is widely used in the manufacturing of printed circuit boards (PCBs), lead frames (LFs), and semiconductor packaged (IC) substrates. Its typical process steps are as follows: First, a dry film resist is coated onto a copper substrate, and then exposed through a mask with a specific pattern; subsequently, a developer is used to remove the unexposed areas, followed by etching or electroplating to form the desired pattern; finally, a stripping solution is used to remove the cured dry film, thus completing the pattern transfer. In this process, the photosensitive resin composition is a key material and a core component of the photosensitive dry film (also known as dry film resist).

[0003] As electronic devices become increasingly miniaturized and denser, PCBs face correspondingly higher demands for precision, density, and the number of layers. For example, high-density, highly integrated PCB products such as high-density interconnect (HDI) boards and packaging substrates typically require line precision of 15 micrometers or even smaller. Therefore, the dry film resist layer, which performs the pattern transfer function, must have higher resolution and maintain excellent adhesion to the copper substrate. This ensures that the dry film remains firmly and intact on the copper-clad laminate substrate even after undergoing rigorous processes such as development, electroplating, or etching, which involve high-pressure spraying and prolonged contact with corrosive chemicals.

[0004] In photosensitive resin compositions, the photoinitiation system directly affects its photosensitivity, resolution, and production yield, with the photosensitizer being a crucial component. Currently, the mainstream anthracene photosensitizers on the market include 9,10-dibutoxyanthracene (DBA), 9,10-diphenylanthracene (DPHA), and 9,10-diacetoxyanthracene (DAcOA). Anthracene compounds or anthracene derivatives, due to their unique structure, can undergo dimerization under light irradiation, thus being photobleached. This characteristic effectively avoids the problem of excessive energy absorption by the upper photosensitizer during exposure, allowing the underlying photosensitive resin composition to receive light more fully, enabling uniform curing and achieving better resolution. However, according to numerous experimental studies and literature reports, these commonly used photosensitizers, in addition to generally suffering from poor adhesion, each have the following limitations:

[0005] (1) Although 9,10-dibutoxyanthracene has good solubility, its CO bond at the 9 and 10 positions is easily broken during exposure, leading to anthracene ring dimerization and the release of small molecule alkoxy fragments. These fragments may migrate from the cured resin to the electroplating solution during subsequent electroplating, causing contamination and thus affecting the life of the plating solution and the quality of electroplating.

[0006] (2) Although DPHA has the advantage of high photon yield, its solubility is poor due to its large molecular conjugation system and high rigidity.

[0007] (3) Due to the electron-withdrawing inductive effect of acyl groups, the electron cloud density at the 9 and 10 positions of the anthracene ring increases, which reduces the photocatalytic curing efficiency. As a result, the verticality of the sidewalls of the cured pattern is not ideal, and the line width difference between the top and bottom is significant, forming an "inverted trapezoidal" structure, which is difficult to meet the requirements of fine circuit manufacturing. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide anthracene methyl acetyl disulfide with photosensitivity that can improve the adhesion of photosensitive resin composition to metal foil and its application.

[0009] The technical solution adopted by the present invention to solve its technical problem is as follows: an anthracene methyl acetyl disulfide for use in photosensitive resin compositions, comprising:

[0010] , One or two of them;

[0011] The R 1 ~R 8 Each is independently selected from one of H, halogen, C1-C12 alkyl, C1-C12 alkoxy, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyl, C6-C12 aryl substituted with one or more C1-C12 alkoxy, C6-C12 aryloxy, C6-C12 aryloxy substituted with one or more halogens, C6-C12 aryloxy substituted with one or more C1-C12 alkyl, and C6-C12 aryloxy substituted with one or more C1-C12 alkoxy.

[0012] The R 9 It is selected from H, halogen, C1-C12 alkyl, C1-C12 alkoxy, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyls, C6-C12 aryl substituted with one or more C1-C12 alkoxys, C6-C12 aryloxy, C6-C12 aryloxy substituted with one or more halogens, C6-C12 aryloxy substituted with one or more C1-C12 alkyls, and C6-C12 aryloxy substituted with one or more C1-C12 alkoxys.

[0013] The R is selected from one of C1-C12 alkyl, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyl, and C6-C12 aryl substituted with one or more C1-C12 alkoxy.

[0014] Preferably, the anthracene methyl acetyl disulfide for the photosensitive resin composition comprises:

[0015] , One or two of them.

[0016] Based on the same inventive concept, the present invention also provides a photosensitive resin composition, comprising, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; wherein the photosensitizer comprises the anthracene methyl acetyl disulfide.

[0017] More preferably, the photosensitizer further includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0018] Preferably, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0019] Preferably, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0020] Preferably, the photoinitiator is a diimidazole compound.

[0021] Preferably, in the comonomers used to synthesize the alkali-soluble resin, the comonomers having aromatic groups account for 50-70% by mass.

[0022] Preferably, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0023] Preferably, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0024] Preferably, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0025] Preferably, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0026] Preferably, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0027] Preferably, the alkali-soluble resin is obtained by polymerizing one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivatives, benzyl methacrylate derivatives, phenyl acrylate, phenyl methacrylate, styrene, and styrene derivatives.

[0028] Preferably, the photopolymerizable monomer is one or more of the following: methoxy polyethylene 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.

[0029] Preferably, the photoinitiator is one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0030] Preferably, by weight, it comprises 55-60 parts of alkali-soluble resin, 40-49 parts of photopolymerizable monomer, 2.2-4 parts of photoinitiator, and 0.1-1 parts of photosensitizer.

[0031] Preferably, it further contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives.

[0032] Based on the same inventive concept, the present invention also provides a photosensitive dry film, comprising a support layer, a photosensitive resist layer and a protective layer disposed sequentially; the photosensitive resist layer comprises at least one of the anthracene methyl acetyl disulfide or the photosensitive resin composition.

[0033] Based on the same inventive concept, the present invention also provides the use of one or more of the anthracene methyl acetyl disulfide, the photosensitive resin composition, or the photosensitive dry film in at least one of a substrate with a resist pattern, a printed circuit board, a lead frame, a semiconductor packaging substrate, a solar cell, and a photocurable ink.

[0034] The present invention has the following beneficial effects: the anthracene methyl acetyl disulfide of the present invention has photosensitivity and can be used as a photosensitizer in photosensitive resin compositions. It can also improve the adhesion of photosensitive resin compositions to various metal surfaces, has low migration characteristics, good compatibility with polymer monomers and solvents, and can be widely used in the field of photocuring such as dry films, paints, coatings, inks and molding materials. It has extremely high photobleaching efficiency and is particularly suitable for use in ultra-thick film formulations.

[0035] The anthracene methyl acetyl disulfide provided by this invention, wherein R 1 ~R 8 and R 9 Substituents on the anthracene ring only affect the photosensitivity and maximum absorption wavelength of the anthracene ring. The low migration, excellent adhesion, and better dispersion stability of anthracene methyl acetyl disulfide are mainly related to factors such as the disulfide bonds, methylene linker arms, acetyl groups, and the weakly polar disulfide bond linkages in the compound, while R... 1 ~R 8 R 9 And R substituents are irrelevant; therefore, R in the anthracene methyl acetyl disulfide 1 ~R 8 R 9 And there are many options for R substituents.

[0036] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0037] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0038] Figure 1 The TM1 manufactured in the embodiments of the present invention 1 H-NMR spectrum;

[0039] Figure 2 The TM1 manufactured in the embodiments of the present invention 13 C-NMR spectrum;

[0040] Figure 3The TM2 manufactured in the embodiments of the present invention 1 H-NMR spectrum;

[0041] Figure 4 It is the TM2 manufactured in the embodiment of the present invention. 13 C-NMR spectrum;

[0042] Figure 5 This is the ultraviolet-visible absorption spectrum of TM1 prepared according to the embodiments of the present invention;

[0043] Figure 6 This is a photobleaching curve of TM1 prepared according to an embodiment of the present invention under 405nm illumination;

[0044] Figure 7 This is the ultraviolet-visible absorption spectrum of TM2 prepared according to the embodiments of the present invention;

[0045] Figure 8 This is a photobleaching curve of TM2 produced in this embodiment of the invention under 405nm illumination. Detailed Implementation

[0046] To make the objectives, solutions, and beneficial technologies of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. It should be noted that the embodiments described in this specification are merely illustrative of the invention and are not intended to limit the invention.

[0047] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0048] In this description, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, "multiple" in "one or more" means two or more, and "more than" in "one or more" means two or more.

[0049] Embodiments of the present invention provide an anthracene methyl acetyl disulfide for use in photosensitive resin compositions, comprising:

[0050] , One or two of them;

[0051] The R 1 ~R8 Each is independently selected from one of H, halogen, C1-C12 alkyl, C1-C12 alkoxy, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyl, C6-C12 aryl substituted with one or more C1-C12 alkoxy, C6-C12 aryloxy, C6-C12 aryloxy substituted with one or more halogens, C6-C12 aryloxy substituted with one or more C1-C12 alkyl, and C6-C12 aryloxy substituted with one or more C1-C12 alkoxy.

[0052] The R 9 It is selected from H, halogen, C1-C12 alkyl, C1-C12 alkoxy, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyls, C6-C12 aryl substituted with one or more C1-C12 alkoxys, C6-C12 aryloxy, C6-C12 aryloxy substituted with one or more halogens, C6-C12 aryloxy substituted with one or more C1-C12 alkyls, and C6-C12 aryloxy substituted with one or more C1-C12 alkoxys.

[0053] The R is selected from one of C1-C12 alkyl, C6-C12 aryl, C6-C12 aryl substituted with one or more halogens, C6-C12 aryl substituted with one or more C1-C12 alkyl, and C6-C12 aryl substituted with one or more C1-C12 alkoxy.

[0054] In embodiments of the present invention, the anthracene methyl acetyl disulfide for the photosensitive resin composition comprises:

[0055] (abbreviated as TM1) One or two of (abbreviated as TM2).

[0056] This invention discloses a photosensitive resin composition, comprising, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; the photosensitizer includes the aforementioned anthracene methyl acetyl disulfide. The anthracene methyl acetyl disulfide is photosensitizing and can be used as a photosensitizer. The "0.1-1 parts" of photosensitizer in the photosensitive resin composition refers to the total amount of anthracene methyl acetyl disulfide and other photosensitizers.

[0057] When the content of alkali-soluble resin is too low, there is a tendency for the resist to flow into a laminar flow; when the content is too high, there is a tendency for the resolution to decrease.

[0058] When the content of photopolymer monomers is too low, there is a tendency for the sensitivity and chemical resistance of the photoresist to decrease. When the content is too high, the photosensitive resin composition is not easy to form a thin film, and the photoresist tends to flow into a laminar adhesive.

[0059] When the photoinitiator content is too low, there is a tendency for the sensitivity and resolution of the resist to decrease; when the content is too high, there is a tendency for more development debris to appear.

[0060] When the photosensitizer content is too low, the sensitivity of the resist tends to decrease. When the content is too high, the resist substrate tends to be incompletely cured, resulting in an "inverted trapezoidal" cross-sectional shape and poor resolution.

[0061] In some embodiments of the present invention, the photosensitizer further includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

[0062] In an embodiment of the present invention, the alkali-soluble resin is an acrylate copolymer containing aromatic groups.

[0063] In embodiments of the present invention, the photopolymerization monomer is an olefinic unsaturated carboxylic acid and / or an olefinic unsaturated carboxylic acid ester.

[0064] In an embodiment of the present invention, the photoinitiator is a diimidazole compound.

[0065] In embodiments of the present invention, the comonomers used to synthesize the alkali-soluble resin contain 50-70% by mass of comonomers having aromatic groups.

[0066] In an embodiment of the present invention, the weight-average molecular weight of the alkali-soluble resin is 20,000 to 60,000.

[0067] In an embodiment of the present invention, the acid value of the alkali-soluble resin is 160-220 mg KOH / g.

[0068] In an embodiment of the present invention, the molecular weight distribution of the alkali-soluble resin is 1.0 to 3.0.

[0069] In embodiments of the present invention, the photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer.

[0070] In an embodiment of the present invention, the photoinitiator is a 2,4,5-triarylimidazolium dimer.

[0071] In embodiments of the present invention, the alkali-soluble resin is obtained by polymerization of one or more of acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, benzyl acrylate derivatives, benzyl methacrylate derivatives, phenyl acrylate, phenyl methacrylate, styrene, and styrene derivatives.

[0072] In embodiments of the present invention, the photopolymerizable monomer is one or more of the following: methoxy polyethylene 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.

[0073] In embodiments of the present invention, the photoinitiator is one or more of 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

[0074] Typical diimidazole compounds, such as hexaaryldiimidazole (HABI), are representative of diimidazole photoinitiators. Their maximum absorption peak is located at 255-275 nm, and they are insensitive to long-wave ultraviolet light (such as 365 nm) and visible light. Another example is 2-(2-hydroxyphenyl)benzimidazole, which has absorption at 320-380 nm and can be matched with UV-A light sources (such as 365 nm LEDs), but is insensitive in the visible light region at 405 nm. This invention uses a photosensitizer to adjust the operating wavelength of diimidazole photoinitiators to around 405 nm.

[0075] In some embodiments of the present invention, the product comprises, by weight, 55-60 parts of alkali-soluble resin, 40-49 parts of photopolymerizable monomer, 2.2-4 parts of photoinitiator, and 0.1-1 parts of photosensitizer.

[0076] In some embodiments of the present invention, the photosensitive resin composition containing the anthracene methyl acetyl disulfide comprises 45 to 48 parts by weight of a photopolymerizable monomer (corresponding to 55 to 60 parts by weight of an alkali-soluble resin).

[0077] In some embodiments of the present invention, the photosensitive resin composition containing the anthracene methyl acetyl disulfide comprises 2.5 to 3.5 parts by weight of a photoinitiator (corresponding to 55 to 60 parts by weight of an alkali-soluble resin).

[0078] In some embodiments of the present invention, the photosensitive resin composition containing the anthracene methyl acetyl disulfide comprises 0.2 to 0.8 parts by weight of photosensitizer (corresponding to 55 to 60 parts by weight of alkali-soluble resin).

[0079] In some embodiments of the present invention, it further contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, photochromic agents, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives (corresponding to 50 to 65 parts by weight of alkali-soluble resin).

[0080] An embodiment of the present invention provides a photosensitive dry film, comprising a support layer, a photosensitive resist layer, and a protective layer disposed sequentially; the photosensitive resist layer comprises at least one of the anthracene methyl acetyl disulfide or the photosensitive resin composition.

[0081] The support layer material of the photosensitive dry film is PET.

[0082] The protective layer material of the photosensitive dry film is PE.

[0083] The application of one or more of the anthracene methyl acetyl disulfide, the photosensitive resin composition, or the photosensitive dry film described in the embodiments of the present invention in at least one of the following: substrates with resist patterns, printed circuit boards, lead frames, semiconductor packaging substrates, solar cells, and photocurable inks.

[0084] This invention proposes an anthracene methyl acetyl disulfide, which has the following technical advantages:

[0085] (1) Inhibit migration crystallization: The anthracene group is flexibly linked by methyl groups, avoiding p-π conjugation caused by direct bonding and avoiding the breakage of carbon heterobonds, thereby effectively inhibiting the generation of small molecule fragments, greatly reducing the risk of photosensitizer molecule fragments penetrating and diffusing into the PE film, and improving product yield.

[0086] (2) Excellent adhesion: The low-valence disulfide bond enhances the binding force between the photosensitive molecule and various transition metals (such as Pd, Pt, Cu, etc.), greatly improving the adhesion of such photosensitizers on metal foil surfaces, especially copper foil surfaces.

[0087] (3) Compared with conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizer of the present invention adopts a strongly polar acetyl group and a weakly polar disulfide bond as the linking arm, which directly results in the molecule exhibiting better solubility, higher formulation compatibility and dispersion stability in various commonly used organic solvents and acrylate monomers. This brings great room for improvement in the formulation design of photosensitive curing compositions.

[0088] R 1 ~R 8 and R 9 Substituents on the anthracene ring only affect the photosensitivity and maximum absorption wavelength of the anthracene ring; the above-mentioned technical advantages of anthracene methyl acetyl disulfide, and R 1 ~R 8 R 9 And R substituents are irrelevant; therefore R 1 ~R 8 R 9 And there are many options for R substituents.

[0089] This invention achieves low migration, excellent adhesion, and better dispersion stability through molecular structure innovation, meeting the needs of high-precision, high-density, and multi-layered high-density circuit manufacturing.

[0090] Example

[0091] The following examples describe the disclosure of this invention in more detail. These examples are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight. Unless otherwise stated, all reagents used in the examples are available commercially or synthesized using conventional methods and are ready for use without further processing. Unless otherwise stated, all instruments used in the examples are available commercially.

[0092] (I) Preparation and detection of anthracene methyl acetyl disulfide

[0093] The following describes the specific preparation methods of anthracene methyl acetyl disulfide, using TM1 and TM2 as examples, and demonstrates their testing. The anthracene methyl acetyl disulfide in this scheme has similar properties. Based on this and combined with common knowledge in the field, those skilled in the art can use similar schemes to the preparation methods of TM1 and TM2 to obtain other anthracene methyl acetyl disulfide preparation methods.

[0094] (1) Preparation of TM1

[0095] The reaction formula for preparing TM1 can be written as:

[0096] .

[0097] The specific preparation method of TM1 is as follows:

[0098] Under a nitrogen atmosphere and with stirring, 9-bromomethylanthracene (0.4 mmol, 0.15 g) and potassium thioacetate (0.52 mmol, 0.059 g) were dissolved in anhydrous dichloromethane (5 mL) in a 25 mL three-necked flask equipped with a magnetic stirrer. The reaction was carried out at room temperature until the reaction was completed as monitored by TLC, which took about 2 h. The resulting reaction mixture was washed with water, extracted with dichloromethane, and washed with saturated brine. The combined organic phases were dried over anhydrous sodium sulfate to obtain the crude product. After purification by column chromatography, 0.1 g of yellow solid TM1 was obtained, with a yield of 84% (developing solvent: petroleum ether / ethyl acetate).

[0099] Figure 1 It's TM1. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.43 (d, J = 8.56 Hz, 3H), 7.99 (dd, J = 8.50, 1.35 Hz, 2H), 7.64 – 7.56 (m, 2H), 7.52 – 7.42 (m, 2H), 4.99 (s, 2H), 2.42 (s, 3H).

[0100] Figure 2 It's TM1. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 195.2, 131.6, 130.7,129.3, 128.6, 126.7, 126.4, 125.4, 124.3, 36.0, 29.2.

[0101] (2) Preparation of TM2

[0102] The reaction formula for preparing TM2 can be written as:

[0103] .

[0104] The specific preparation method of TM2 is as follows:

[0105] Under a nitrogen atmosphere and with stirring, 9-bromomethylanthracene (0.4 mmol, 0.232 g) and potassium thioacetate (1.0 mmol, 0.114 g) were dissolved in anhydrous dichloromethane (10 mL) in a 25 mL three-necked flask equipped with a magnetic stirrer. The reaction was carried out at room temperature until the reaction was completed as monitored by TLC, which took about 2 h. The resulting reaction mixture was washed with water, extracted with dichloromethane, and washed with saturated brine. The resulting organic phases were combined and dried with anhydrous sodium sulfate to obtain a crude product. The crude product was purified by column chromatography to obtain a yellow solid TM1 0.131 g, yield: 79% (developing solvent: petroleum ether / ethyl acetate).

[0106] Figure 3 It's TM2. 1 H-NMR spectrum; 1 H NMR (400 MHz, CDCl3): δ 8.50 (dd, J = 6.9, 3.2Hz, 4H), 7.64 (dd, J = 6.9, 3.3 Hz, 4H), 4.98 (s, 4H), 2.45 (s, 6H).

[0107] Figure 4 It's TM2. 13 C-NMR spectrum; 13 C NMR (100 MHz, CDCl3): δ 194.1, 129.5, 127.1, 125.6, 124.1, 76.5, 75.9, 35.2, 28.2.

[0108] (3) Ultraviolet-visible spectroscopy and photobleaching experiment

[0109] The ultraviolet-visible absorption spectra were measured using a Shimadzu UV-1900 ultraviolet-visible spectrophotometer, with toluene as the solvent (concentration 4×10⁻⁶). -5 The UV absorption of the test sample was measured at mol / L. The photobleaching experiment used toluene as the solvent (concentration 4 × 10⁻⁶ mol / L). - 5 The UV-Vis absorption spectrum of the sample solution (mol / L) was measured at fixed time intervals using a Shimadzu UV-1900 UV-Vis spectrophotometer under 405 nm light source illumination. Furthermore, the molar extinction coefficient ε = A was calculated according to Beer-Lambert's law. bn / c, where A bn ν represents the absorbance of the UV-Vis absorption spectrum, and c represents the concentration (mol / L).

[0110] The molar extinction coefficients of TM1, TM2, and DBA are shown in Table 1.

[0111] Table 1. Molar extinction coefficients of TM1, TM2, and DBA

[0112]

[0113] As can be seen from the molar extinction coefficients in Table 1, the molar extinction coefficient of anthracene methyl acetyl disulfide TM1 of the present invention is comparable to that of DBA, while that of TM2 is slightly higher than that of DBA; this proves that such photosensitizers have excellent photo-radical conversion capabilities and great photosensitivity potential, thereby initiating the curing of the photosensitive composition.

[0114] The UV-Vis absorption spectrum of TM1 is shown below. Figure 5 The photobleaching curve of TM1 under 405nm illumination is shown below. Figure 6 The UV-Vis absorption spectrum of TM2 is shown below. Figure 7 The photobleaching curve of TM2 under 405nm illumination is shown below. Figure 8 The photobleaching results show that the anthracene methyl acetyl disulfide of this invention has extremely high photobleaching efficiency, and photobleaching can be basically achieved within 15 minutes, making it particularly suitable for use in ultra-thick film formulations.

[0115] (3) Solubility and compatibility test

[0116] Using TM1, TM2, DBA, DPHA, and DacOA as solutes, their solubility in various solvents and compatibility with monomers were tested. The solutes were added to the solvents at a ratio of 0.1 g solute / 1 g solvent (10% w / w), and the solubility was recorded according to the following classification criteria:

[0117] Advantages: Rapid dissolution; under room temperature and stirring conditions, a clear, transparent, and homogeneous solution can be formed within 1 minute.

[0118] Medium - dissolves slowly; under room temperature and stirring conditions, it can form a clear, transparent and uniform solution in more than 5 minutes; or it cannot completely dissolve at room temperature, but can form a clear, transparent and uniform solution when heated to 50~60℃, and there is no obvious turbidity after returning to room temperature.

[0119] Poor - Partially dissolves; cannot completely dissolve after 5 minutes or more under room temperature and stirring conditions; or can completely dissolve when heated to 50~60℃, but becomes noticeably cloudy after returning to room temperature.

[0120] The test results are shown in Table 2. The solvents are represented by acetone, toluene, and methanol; the monomers are represented by a mixture consisting of 5g of methoxy polyethylene glycol (350) monoacrylate, 20g of 10(ethoxy)bisphenol A dimethacrylate, 5g of 6(propoxy)bisphenol A dimethacrylate, 10g of 3(ethoxy)trimethylolpropane triacrylate, and 4g of di(trimethylolpropane)tetraacrylate, which is denoted as "monomer" in Table 2.

[0121] Table 2. Solubility test results of TM1, TM2, DBA, DPHA and DacOA

[0122]

[0123] As can be seen from the data in Table 2, compared with conventional photosensitizers DBA, DPHA and DAcOA in the prior art, the photosensitizers TM1 and TM2 of the present invention exhibit superior solubility in various commonly used organic solvents and good compatibility with monomers.

[0124] (II) Preparation of photosensitive resin composition

[0125] Examples and comparative examples were set up. Examples 1-10 directly used TM1 and TM2 as photosensitizers, while the comparative examples used DBA, DPHA, and DAcOA as photosensitizers, respectively. For ease of comparison, Examples 9 and 10 used the same proportions as Comparative Examples 1-3. Referring to the formulations shown in Table 3, the components were mixed evenly to prepare a photosensitive resin composition. The data in Table 3 are in parts by mass, and "-" indicates that it was not added.

[0126] Table 3 Formulations of the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3

[0127]

[0128] The components and specific information of each component code in Table 3 are as follows:

[0129] Alkali-soluble resin (A): Acrylic ester copolymer, solution polymerization, by mass ratio, methacrylic acid / butyl methacrylate / benzyl methacrylate = 25 / 10 / 65; solvent is acetone, solid content 46%, weight average molecular weight 40000, dispersity 2.1, acid value 163mgKOH / g (Hunan Chuyuan New Materials Co., Ltd.).

[0130] Photopolymerizable monomer (B) is composed of the following components (purchased from Sartoma Guangzhou Chemical Co., Ltd.): 5 parts of methoxy polyethylene glycol (350) monoacrylate, 20 parts of 10 (ethoxy) bisphenol A dimethacrylate, 5 parts of 6 (propoxy) bisphenol A dimethacrylate, 10 parts of 3 (ethoxy) trimethylolpropane triacrylate, and 4 parts of di (trimethylolpropane) tetraacrylate.

[0131] Photoinitiator (C): 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-diimidazole (BCIM), purchased from Jiuding Chemical;

[0132] Photosensitizer (D): DBA is 9,10-dibutoxyanthracene, DPHA is 9,10-diphenylanthracene, and DAcOA is 9,10-diacetoxyanthracene, all purchased from Leyan;

[0133] Additive (E) consists of the following ingredients (purchased from Anaiji Chemical): 0.5 parts of leuco crystal violet, 0.05 parts of malachite green, 0.8 parts of p-toluenesulfonamide, and 0.03 parts of 2,6-di-tert-butyl-4-methylphenol;

[0134] The solvent consists of the following components: 8 parts acetone, 10 parts toluene, and 5 parts methanol.

[0135] (III) Preparation of photosensitive dry film

[0136] Photosensitive dry films were prepared using the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3 as raw materials, including the following steps:

[0137] Using experimental equipment (model: AB4220, TQC, Netherlands), the prepared photosensitive resin composition slurry was coated onto a 15μm thick polyethylene terephthalate (PET) support film; the solvent was removed by baking at 80℃ for 10min; after baking, the thickness of the photosensitive layer was controlled at 30μm, and then a polyethylene film (PE) was applied for protection to obtain a photosensitive dry film.

[0138] Before coating, acetone solvent can be added to the photosensitive resin composition to adjust it to a suitable viscosity for coating. The solvent will be removed after baking and will not affect the composition of the photosensitive dry film.

[0139] (iv) Preparation of substrates with resist patterns

[0140] Substrates with resist patterns were prepared using the photosensitive resin compositions of Examples 1-10 and Comparative Examples 1-3 as raw materials, and the procedures are as follows:

[0141] (1) Photosensitive layer formation process: A photosensitive layer is formed on a substrate using a photosensitive composition;

[0142] (2) Exposure process: At least a portion of the above photosensitive layer is irradiated with active light to photocur the above area to form a cured area;

[0143] (3) Development process: Remove at least a portion of the above photosensitive layer, excluding the cured area, from the substrate to form a resist pattern on the substrate.

[0144] The operating conditions for each process are explained in detail below.

[0145] Photosensitive layer formation process: Using a copper-clad laminate with a 35μm thick rolled 1.2mm thick copper foil, after surface adjustment and preheating to 80°C, while peeling off the PE protective film of the photosensitive dry film obtained from each embodiment or comparative example, the above-mentioned photosensitive resin composition is laminated onto the copper-clad laminate using a hot roller laminator (Zhisheng Technology Co., Ltd., CSL-M25E) at a roller temperature of 110°C, an air pressure of 0.35MPa, and a lamination speed of 1.5m / min to obtain a test substrate.

[0146] Exposure process: Exposure is performed using a direct drawing exposure machine (Xinge Microelectronics, main wavelength 405nm), and the sensitivity is tested using a Stouffer 41-level step exposure scale, with the number of exposure frames controlled between 14 and 18.

[0147] Development Process: After exposure, the PET support film is peeled off. Using an alkaline developer (manufactured by Guangzhou Julong Printed Circuit Board Equipment Co., Ltd., a dry film developer), a 1wt% Na₂CO₃ aqueous solution at 30°C is sprayed for twice the minimum development time to dissolve and remove the unexposed portions of the photosensitive resin layer. After development, the substrate is rinsed with pure water for 1.5 times the development time, dehydrated using an air knife, and then dried with warm air to obtain a substrate with a cured film for evaluation. The minimum development time is the shortest time required for complete dissolution of the unexposed photosensitive resin layer.

[0148] (v) Evaluation Items

[0149] (1) Evaluation of photosensitivity

[0150] Photosensitivity evaluation tests were conducted on Examples 1-10 and Comparative Examples 1-3. A Stouffer 41-level segmented exposure scale was placed on the test substrate after the film was applied for photosensitivity testing. After the exposure process, the test substrate was left to stand for at least 20 minutes, 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. The development time was 2.0 times the minimum development time. After the above operations, a cured film obtained by curing the photosensitive resin composition was formed on the substrate surface. The exposure energy (mJ / cm²) when the number of residual segments on the segmented exposure scale obtained through the cured film was 16 segments. 2The photosensitivity of the photosensitive resin composition was evaluated, with a smaller value indicating better photosensitivity.

[0151] (2) Adhesion evaluation

[0152] Adhesion evaluation tests were conducted on Examples 1-10 and Comparative Examples 1-3. On the test substrates after film application, photomask data with a wiring pattern of linewidth / spacing width n:400 (unit: μm) was used to expose the substrates at an energy level that resulted in 16 residual stages after development using a Stouffer 41-stage exposure ruler. After the development process, the resist pattern was observed using an optical microscope. The minimum linewidth at which a complete cured resist line was formed was used as the adhesion value to evaluate adhesion (μm). The smaller this value, the better the adhesion.

[0153] (3) Evaluation of corrosion resist migration

[0154] The photoresist migration of Examples 1-10 and Comparative Examples 1-3 was evaluated. After the prepared three-layer photosensitive dry film was completed, the UV absorption spectrum of the dry film was detected using a UV spectrophotometer to obtain the absorbance A1 of the maximum absorption peak in the 350-450 nm range. The dry film was then placed at 30°C for 72 hours. After removing the PE film layer from the surface of the photosensitive dry film, the UV absorption spectra of the PET layer and the photoresist layer were detected using a UV spectrophotometer to obtain the absorbance A2 of the maximum absorption peak in the 350-450 nm range. If the sensitizer migrates to the surface of the PE layer, the absorbance of the maximum absorption peak in the 350-450 nm range of the PET layer and the photoresist layer will decrease, i.e., the absorbance of the sensitizer that migrated to the PE layer is (A1). - A2). Calculate the migration rate of the photosensitizer, i.e., migration rate A = (A1) / (A2). - The larger the value of A2 / A1, the greater the migration amount.

[0155] Basis for judgment:

[0156] ○: Mobility A < 0.01;

[0157] ×: Mobility A > 0.01.

[0158] (4) Evaluation of dispersion stability

[0159] The prepared photosensitive dry film was stored in the dark at 25°C for 2 weeks. The surface of the photosensitive layer was observed under a microscope and graded as follows:

[0160] ■ Indicates a uniform surface of the photosensitive layer;

[0161] × indicates undissolved material precipitated on the surface of the photosensitive layer.

[0162] Examples 1-10 used TM1-TM2 as photosensitizers and conducted experiments at different dosages. The results of each example in Table 4 show that TM1-TM2 not only greatly reduced the migration rate but also demonstrated excellent adhesion enhancement. The dispersion stability evaluation results of Examples 1-10 show that the obtained resin compositions have excellent stability.

[0163] Examples 9 and 10 used TM1-TM2 as photosensitizers, while Comparative Examples 1-3 used DBA, DPHA, and DAcOA as photosensitizers, respectively, and the amount of photosensitizer used in the above examples was the same. By comparing the results of Examples 9 and 10 with those of Comparative Examples 1-3 in Table 4, it can be seen that the photosensitive resin composition using anthracene methyl acetyl disulfide of the present invention as a photosensitizer has lower exposure energy under the same mass concentration conditions, indicating that its photosensitivity is superior to that of DBA and DAcOA. In addition, the anthracene methyl acetyl disulfide of the present invention shows advantages in terms of adhesion, migration, and dispersion stability.

[0164] Table 4. Test results of each evaluation item in Examples 1-10 and Comparative Examples 1-3

[0165]

[0166] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Those skilled in the art can make various modifications and alterations within the spirit and principles of the present invention, and any modifications, equivalent substitutions, or improvements within this scope should be considered as covered by the protection scope of the present invention.

Claims

1. An anthracene methyl acetyl disulfide for use in photosensitive resin compositions, characterized in that, include: , One or two of them.

2. A photosensitive resin composition, characterized in that, The product comprises, by weight, 50-65 parts of alkali-soluble resin, 35-50 parts of photopolymerizable monomer, 2-5 parts of photoinitiator, and 0.1-1 parts of photosensitizer; wherein the photosensitizer comprises the anthracene methyl acetyl disulfide as described in claim 1.

3. The photosensitive resin composition according to claim 2, characterized in that, The photosensitizer also includes one or more of 9,10-dibutoxyanthracene, 9,10-diacetoxyanthracene, and 9,10-diphenylanthracene.

4. The photosensitive resin composition according to claim 2 or 3, characterized in that, The alkali-soluble resin is an acrylate copolymer containing aromatic groups; the photopolymerization monomer is an olefin unsaturated carboxylic acid and / or an olefin unsaturated carboxylic acid ester; and the photoinitiator is a diimidazole compound.

5. The photosensitive resin composition according to claim 2 or 3, characterized in that, In the comonomers used to synthesize the alkali-soluble resin, the comonomers having aromatic groups account for 50-70% by mass; the weight-average molecular weight of the alkali-soluble resin is 20,000-60,000; the acid value of the alkali-soluble resin is 160-220 mg KOH / g; and the molecular weight distribution of the alkali-soluble resin is 1.0-3.

0. The photopolymerization monomer is a methacrylate monomer and / or an acrylate monomer; The photoinitiator is a 2,4,5-triarylimidazolium dimer.

6. The photosensitive resin composition according to claim 2 or 3, characterized in that, The alkali-soluble resin is obtained by polymerizing one or more of the following: acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, and styrene. The photopolymerizable monomer is one or more of the following: methoxy polyethylene glycol monoacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, di(trimethylolpropane)tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate. The photoinitiator is one or more of the following: 2-(2-chlorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazolium dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazolium dimer, 2-(2-methoxyphenyl)-4,5-diphenylimidazolium dimer, 2-(4-methoxyphenyl)-4,5-diphenylimidazolium dimer, and 2,2',4-tris(2-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenyl-1,1'-diimidazole.

7. The photosensitive resin composition according to claim 2 or 3, characterized in that, It also contains 0.5 to 5.0 parts by weight of additives; the additives are one or more of the following: dyes, light color developers, plasticizers, adhesion promoters, polymerization inhibitors, defoamers, leveling agents, thickeners, dispersants, lubricants, waterproofing agents, and preservatives.

8. A photosensitive dry film, characterized in that, It includes a support layer, a photoresist layer and a protective layer arranged sequentially; the photoresist layer comprises at least one of the anthracene methyl acetyl disulfide as described in claim 1 or the photosensitive resin composition as described in any one of claims 2 to 7.

9. The use of the anthracene methyl acetyl disulfide as described in claim 1 in at least one of a substrate with resist pattern, a printed circuit board, a lead frame, a semiconductor packaging substrate, a solar cell, and a photocurable ink.

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