Alkali-soluble resin, preparation method thereof, photosensitive resin composition and application thereof

Abstract

The invention belongs to the technical field of polymer materials, and provides alkali-soluble resin, a preparation method thereof, a photosensitive resin composition and application thereof. The preparation method of the alkali-soluble resin comprises the following steps: reacting epoxy resin with unsaturated monoacid to obtain a prepolymer; and carrying out a reaction on the prepolymer and acid anhydride to obtain the alkali-soluble resin. Through the design and combined action of the raw materials and the process, the alkali-soluble resin and the photosensitive resin composition containing the alkali-soluble resin have an excellent developing effect, a developed pattern is clear, the pattern resolution is high, the adhesive force with a substrate is good, the hardness is high, and the alkali-soluble resin and the photosensitive resin composition are particularly suitable for scenes needing laminated printing; and the problem of deformation of the multi-layer laminated coating curing pattern is effectively avoided, and the pattern quality is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to an alkali-soluble resin, a preparation method thereof, a photosensitive resin composition and an application thereof. Background Art

[0002] A photoresist, also known as a lithographic resist, usually includes components such as a film-forming resin, a photoinitiator and a solvent. It can change its solubility through exposure, and then form a micron- or nanoscale pattern, and has a wide range of applications in the processing of semiconductor chips, printed circuit boards, flexible circuit boards, integrated circuits, battery boards, display panels and their control circuits. Photoresists can be divided into positive and negative types. For positive photoresists, the exposed areas are washed away by the developer after exposure, and the unexposed areas remain on the substrate, thus forming the same pattern as the mask plate; for negative photoresists, it is the opposite, and the unexposed areas are washed away by the developer to form a pattern that is completely inverted from the mask plate.

[0003] Alkali-soluble resin is one of the most widely used materials in photoresists. Its properties directly determine the resolution, adhesion, chemical resistance and development characteristics of photoresists, and thus affect the pattern quality obtained by exposure and development. Therefore, the development of alkali-soluble resins is an important research topic in the industry. For example, CN104407500A discloses a photosensitive resin composition, which contains the following components: 50-70 parts by weight of an alkali-soluble resin, 25-45 parts by weight of a monomer capable of undergoing a photo-radical polymerization reaction, 0.1-10 parts by weight of a photoinitiator; the alkali-soluble resin is a copolymer of methacrylic acid, acrylic acid, methyl methacrylate, lauryl acrylate, and phenoxyethyl acrylate, and its weight average molecular weight is 30,000-120,000. CN114967336A discloses a photosensitive resin composition, which includes an alkali-soluble resin, a photopolymerizable monomer, an epoxy resin, a curing agent, an inorganic filler and a photoinitiator. The alkali-soluble resin is a rigid epoxy acrylate resin containing carboxyl groups, and the epoxy resin includes a rigid structure-modified epoxy resin and a flexible structure-modified epoxy resin. CN108779331A discloses a resin composition, including component (a): at least one selected from alkali-soluble polyimide, alkali-soluble polybenzoxazole, alkali-soluble polyamideimide, their precursors and their copolymers; it also includes component (b): an alkali-soluble phenolic resin; and the alkali dissolution rate R of component (b) b and the alkali dissolution rate R of component (a) a satisfy the relationship: 0.5 ≤ R b / R a≤2.0. CN109270792A discloses a photosensitive resin composition, comprising: 100 parts by weight of an alkali-soluble photosensitive epoxy acrylate resin with an acid value of 60 - 150 mg KOH / g, 20 - 50 parts by weight of an alkali-soluble polyimide resin, 10 - 40 parts by weight of an acrylate monomer, 0.1 - 10 parts by weight of a photoinitiator, 20 - 60 parts by weight of a thermal curing agent, 0 - 2 parts by weight of a pigment, and 0.01 - 1 part by weight of an auxiliary agent.

[0004] Currently, the alkali-soluble resins known in the industry mainly include phenolic resins, epoxy resins, acrylate resins, polyimide resins, etc.; among them, the curing temperature of the alkali-soluble polyimide resin is relatively high (usually > 300 °C), which limits its application in temperature-sensitive scenarios. Moreover, the existing alkali-soluble resins and the photoresists containing them have certain deficiencies in terms of development effect, adhesion to the substrate, film hardness, etc., and the development time is relatively strict, the process window is narrow, the error tolerance is low, and it is easy to cause a decrease in the yield. Therefore, developing new alkali-soluble resins to improve the development effect, substrate adhesion and hardness of photosensitive materials is the research focus in this field. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an alkali-soluble resin and its preparation method, a photosensitive resin composition and its application. Through the design and combined action of raw materials and processes, the alkali-soluble resin and the photosensitive resin composition containing it have excellent development effects, high adhesion to the substrate, high hardness, and significantly improve the pattern quality.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a preparation method of an alkali-soluble resin, and the preparation method comprises the following steps:

[0008] (1) React an epoxy resin with an unsaturated monobasic acid to obtain a prepolymer;

[0009] (2) React the prepolymer obtained in step (1) with an acid anhydride to obtain the alkali-soluble resin.

[0010] In the preparation method of the alkali-soluble resin provided by the present invention, first, an epoxy resin reacts with an unsaturated monocarboxylic acid to consume epoxy groups, obtaining a prepolymer containing unsaturated double bonds and hydroxyl groups; the prepolymer further reacts with an acid anhydride to obtain an alkali-soluble resin containing carboxyl groups. Through the design and co-action of raw materials and processes, the alkali-soluble resin and the photosensitive resin composition containing the same of the present invention have excellent development effects, with clear developed patterns, high graphic resolution, high adhesion to various substrates such as ceramic substrates, metal plates, and glass plates, high hardness, and are particularly suitable for scenarios requiring laminated printing (such as UV silver paste resins for chip laminated inductors and UV silver paste resins for flexible circuit boards), effectively avoiding the problem of pattern deformation in multi-layer laminated coating and curing, and significantly improving the pattern quality.

[0011] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0012] Preferably, the epoxy resin includes any one or a combination of at least two of bisphenol A epoxy resin, bisphenol F epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene phenol epoxy resin, and alicyclic epoxy resin.

[0013] In the present invention, the unsaturated monocarboxylic acid contains 1 carboxyl group and at least 1 unsaturated C═C double bond. Preferably, the unsaturated monocarboxylic acid is a C3-C20 (such as C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, or C18, etc.) unsaturated monocarboxylic acid.

[0014] Preferably, the unsaturated monocarboxylic acid includes any one or a combination of at least two of acrylic acid, crotonic acid, and methacrylic acid.

[0015] Preferably, the molar ratio of the epoxy groups in the epoxy resin to the unsaturated monocarboxylic acid is 1:(1-1.1), and can be, for example, 1:1.01, 1:1.02, 1:1.03, 1:1.04, 1:1.05, 1:1.06, 1:1.07, 1:1.08, or 1:1.09, etc.

[0016] Preferably, the reaction in step (1) is carried out in the presence of a catalyst.

[0017] Preferably, the catalyst includes any one or a combination of at least two of tetraethylammonium bromide, tetrabutylammonium bromide, triphenylphosphine, and N,N-dimethylbenzylamine.

[0018] Preferably, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the catalyst is 0.1 - 1%, for example, it can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8% or 0.9%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0019] Preferably, the reaction in step (1) is carried out in the presence of an inhibitor.

[0020] Preferably, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the inhibitor is 0.02 - 0.5%, for example, it can be 0.03%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.28%, 0.3%, 0.35%, 0.35%, 0.38%, 0.4%, 0.42%, 0.45% or 0.48%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0021] Preferably, the inhibitor includes phenolic inhibitors and / or stable free radical inhibitors, and further preferably a combination of phenolic inhibitors and stable free radical inhibitors.

[0022] Preferably, the phenolic inhibitor includes any one or a combination of at least two of hydroquinone, p-tert-butylcatechol, catechol, 2,6-di-tert-butyl-p-cresol, p-methoxyphenol, and p-hydroxyanisole.

[0023] Preferably, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the phenolic inhibitor is 0.01 - 0.2%, for example, it can be 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15% or 0.18%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0024] Preferably, the stable free radical inhibitor includes 2,2,6,6-tetramethyl-4-hydroxypiperidine 1-oxyl (ZJ-701) and / or tetramethylpiperidine 1-oxyl phosphite (ZJ-705).

[0025] Preferably, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the stable free radical type inhibitor is 0.01 - 0.2%, for example, it can be 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15% or 0.18%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0026] Preferably, the reaction in step (1) is carried out in the presence of an organic solvent.

[0027] Preferably, the organic solvent includes any one or a combination of at least two of ether solvents, ester solvents, and ketone solvents.

[0028] More preferably, the organic solvent includes any one or a combination of at least two of diethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, and dipropylene glycol methyl ether acetate.

[0029] Preferably, the mass ratio of the epoxy resin to the organic solvent is 1:(0.1 - 3), for example, it can be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.2, 1:2.5 or 1:2.8, etc.

[0030] Preferably, the method of the reaction in step (1) includes: mixing the epoxy resin and the organic solvent evenly, adding a catalyst thereto, then adding a mixture of the unsaturated monocarboxylic acid and the inhibitor, and carrying out the reaction after the addition is completed to obtain a prepolymer.

[0031] Preferably, the reaction in step (1) is carried out in a protective atmosphere.

[0032] Preferably, the protective atmosphere includes at least one of a nitrogen atmosphere, an argon atmosphere, or a helium atmosphere.

[0033] Preferably, the mixture of the unsaturated monocarboxylic acid and the inhibitor is slowly added to the reaction system, and more preferably, the mixture is added dropwise to the reaction system.

[0034] Preferably, the addition time of the mixture of the unsaturated monocarboxylic acid and the inhibitor is 0.5 - 3 h, for example, it can be 0.8 h, 1 h, 1.2 h, 1.5 h, 1.8 h, 2 h, 2.2 h, 2.5 h or 2.8 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range.

[0035] Preferably, the temperature of the reaction in step (1) is 80-110 °C, for example, it can be 82 °C, 85 °C, 88 °C, 90 °C, 92 °C, 95 °C, 98 °C, 100 °C, 102 °C, 105 °C or 108 °C, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 90-100 °C.

[0036] Preferably, the reaction time in step (1) is 2-10 h, for example, it can be 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, 8.5 h, 9 h or 9.5 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 4-8 h.

[0037] Preferably, the acid value of the product (the prepolymer) of the reaction in step (1) is ≤1 mg KOH / g. For example, the acid value of the product of the neutralization reaction can be 0.1 mg KOH / g, 0.2 mg KOH / g, 0.3 mg KOH / g, 0.4 mg KOH / g, 0.5 mg KOH / g, 0.6 mg KOH / g, 0.7 mg KOH / g, 0.8 mg KOH / g, 0.9 mg KOH / g or 0.95 mg KOH / g, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range.

[0038] Preferably, the acid anhydride includes any one or a combination of at least two of maleic anhydride, norbornene dicarboxylic anhydride, itaconic anhydride, acrylic anhydride, methacrylic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride.

[0039] Preferably, based on the mass of the prepolymer being 100%, the mass of the acid anhydride is 20-40%, for example, it can be 22%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 35%, 36% or 38%, as well as the specific point values between the above point values. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific point values included in the above range. Further preferably, it is 25-35%.

[0040] It should be noted that the mass of the prepolymer is the mass of the reaction product of epoxy resin and unsaturated monocarboxylic acid, that is, the solid content, and does not include the organic solvents present in the reaction system.

[0041] Preferably, the temperature of the reaction in step (2) is 80-110°C, for example, it can be 82°C, 85°C, 88°C, 90°C, 92°C, 95°C, 98°C, 100°C, 102°C, 105°C or 108°C, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 90-100°C.

[0042] Preferably, the reaction time in step (2) is 1-8 h, for example, it can be 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h or 7.5 h, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 2-6 h.

[0043] Preferably, the reaction in step (2) is terminated until the acid value of the system remains stable.

[0044] In a preferred technical solution, the preparation method of the alkali-soluble resin comprises the following steps:

[0045] (1) After uniformly mixing the epoxy resin with an organic solvent, a catalyst is added thereto, and then a mixture of an unsaturated monocarboxylic acid and a polymerization inhibitor is added to the reaction system under a protective atmosphere. The addition time of the mixture is 0.5-3 h. After the addition is completed, the reaction is carried out at 80-110°C for 2-10 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0046] The molar ratio of the epoxy group in the epoxy resin to the unsaturated monocarboxylic acid is 1:(1-1.1); based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the catalyst is 0.1-1%, and the mass of the polymerization inhibitor is 0.02-0.5%;

[0047] (2) Reacting the prepolymer obtained in step (1) with an acid anhydride at 80-110°C for 1-8 h to obtain the alkali-soluble resin; based on the mass of the prepolymer being 100%, the mass of the acid anhydride is 20-40%.

[0048] Preferably, the alkali-soluble resin obtained by the preparation method is a colloidal solution of the alkali-soluble resin, and the solid content of the colloidal solution is 40-80%, for example, it can be 45%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70% or 75%, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 55-65%.

[0049] Second aspect, the present invention provides an alkali-soluble resin, which is prepared by the preparation method as described in the first aspect.

[0050] Preferably, the acid value of the alkali-soluble resin is 10 - 80 mg KOH / g, for example, it can be 15 mg KOH / g, 20 mg KOH / g, 25 mg KOH / g, 30 mg KOH / g, 35 mg KOH / g, 40 mg KOH / g, 45 mg KOH / g, 50 mg KOH / g, 55 mg KOH / g, 60 mg KOH / g, 65 mg KOH / g, 70 mg KOH / g or 75 mg KOH / g, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0051] Preferably, the number-average molecular weight of the alkali-soluble resin is 1000 - 5000, for example, it can be 1200, 1500, 1800, 2000, 2200, 2500, 2800, 3000, 3200, 3500, 3800, 4000, 4200, 4500 or 4800, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0052] Third aspect, the present invention provides a photosensitive resin composition, which comprises a combination of the alkali-soluble resin as described in the second aspect, a photoinitiator and a photosensitive monomer.

[0053] Preferably, the photosensitive resin composition comprises the following components by mass parts:

[0054] Alkali-soluble resin 60 - 85 parts,

[0055] Photoinitiator 0.1 - 8 parts,

[0056] Photosensitive monomer 10 - 40 parts.

[0057] The mass parts of the alkali-soluble resin are 60 - 85 parts, for example, it can be 62 parts, 65 parts, 68 parts, 70 parts, 72 parts, 75 parts, 78 parts, 80 parts, 82 parts or 84 parts, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0058] The mass parts of the photoinitiator are 0.1 - 8 parts, for example, it can be 0.5 part, 0.8 part, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, 4.5 parts, 4.8 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts or 7.5 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0059] The mass parts of the photosensitive monomer are 10 - 40 parts, for example, it can be 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts or 38 parts, as well as the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0060] Preferably, the photoinitiator includes any one or a combination of at least two of ethyl 2,4,6 - trimethylbenzoyl phenylphosphinate (photoinitiator TPO - L), 2,4,6 - trimethylbenzoyl - bis(p - tolyl)phosphine oxide (TMO), 2 - hydroxy - 2 - methylpropiophenone (photoinitiator 184), 1 - hydroxycyclohexyl phenyl ketone (photoinitiator 1173), 2 - methyl - 1 - (4 - methylthiophenyl)-2 - morpholinopropan - 1 - one (photoinitiator 907), phenylbis(2,4,6 - trimethylbenzoyl)phosphine oxide (photoinitiator 819), 2 - benzyl - 2 - dimethylamino - 1 - (4 - morpholinophenyl)butan - 1 - one (photoinitiator 369), 2 - isopropylthioxanthone (photoinitiator ITX), 2,4 - diethylthioxanthone (photoinitiator DETX), benzoin dimethyl ether (photoinitiator 651), diphenyl(2,4,6 - trimethylbenzoyl)phosphine oxide (photoinitiator TPO).

[0061] Preferably, the photosensitive monomer includes any one or a combination of at least two of isooctyl (meth)acrylate, isobornyl (meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetrahydrofuran (meth)acrylate.

[0062] It should be noted that the term “isooctyl (meth)acrylate” means isooctyl acrylate and / or isooctyl methacrylate. The term “hexanediol di(meth)acrylate” means hexanediol diacrylate and / or hexanediol dimethacrylate. Other expressions have similar meanings. For the sake of simplicity, they will not be elaborated one by one.

[0063] Further preferably, the photosensitive monomer includes any one or a combination of at least two of isooctyl acrylate, isobornyl acrylate, isobornyl methacrylate, methyl methacrylate, butyl acrylate, hexanediol diacrylate, neopentyl glycol diacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, and tetrahydrofuran acrylate.

[0064] Preferably, the photosensitive resin composition further includes a solvent.

[0065] Preferably, the photosensitive resin composition can form a patterned film with a pattern of a specific shape through coating and film formation, ultraviolet irradiation curing, and development.

[0066] Preferably, the developer for the development is an alkaline solution.

[0067] Preferably, the alkaline substance in the alkaline solution includes, but is not limited to, any one or a combination of at least two of NaOH, Na2CO3, KOH, and tetramethylammonium hydroxide (TMAH).

[0068] Preferably, the mass concentration of the alkaline substance in the alkaline solution is 0.1-2%, for example, it can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.8%, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 0.2-1%.

[0069] Preferably, the development time is 20-60 s, for example, it can be 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, or 55 s, and the specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the range. Further preferably, it is 30-45 s.

[0070] As a preferred technical solution of the present invention, through the design of the alkali-soluble resin, the photosensitive resin composition can achieve a development process window with clear patterns when rinsed with a 0.4% aqueous solution of Na2CO3 for 30-45 s, and 20 layers of overcoating printing do not deform.

[0071] Fourthly, the present invention provides a photosensitive silver paste, which includes silver powder and the photosensitive resin composition as described in the third aspect.

[0072] Preferably, the photosensitive silver paste includes the following components by mass:

[0073] 15-30 parts of the photosensitive resin composition,

[0074] 70 - 85 parts by mass of silver powder.

[0075] The mass parts of the photosensitive resin composition are 15 - 30. For example, it can be 16 parts, 18 parts, 20 parts, 22 parts, 24 parts, 25 parts, 26 parts or 28 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0076] The mass parts of the silver powder are 70 - 85. For example, it can be 72 parts, 74 parts, 75 parts, 76 parts, 78 parts, 80 parts, 82 parts or 84 parts, as well as specific point values between the above point values. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the above range.

[0077] As a preferred technical solution of the present invention, the alkali - soluble resin and the photosensitive resin composition are used to prepare a photosensitive silver paste, which can have excellent development effects under the condition of high silver powder content, and at the same time has high adhesion to the substrate, high hardness, and excellent pattern quality. It is especially suitable for scenarios that require laminated printing, effectively avoiding the problem of pattern deformation after multi - layer lamination.

[0078] In the fifth aspect, the present invention provides an application of the photosensitive silver paste as described in the fourth aspect in a chip - type laminated inductor or a flexible circuit board.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] (1) In the alkali - soluble resin provided by the present invention, through the design and co - action of raw materials and processes, the alkali - soluble resin and the photosensitive resin composition containing it have excellent development effects. The developed pattern is clear, the graphic resolution is high, the adhesion to the substrate is good, the hardness is high. It is especially suitable for scenarios that require laminated printing, effectively avoiding the problem of pattern deformation after multi - layer coating and curing, and significantly improving the pattern quality.

[0081] (2) Through the design and optimization of the alkali - soluble resin, the photosensitive resin composition containing it can achieve a development process window with clear patterns when rinsed with a 0.4% Na2CO3 aqueous solution for 30 - 45 s. The development effect is good, the graphic resolution is high, the minimum line width and line pitch ≤ 25 μm, the hardness is large, no obvious deformation occurs after 20 layers of laminated printing, and the adhesion to the substrate is high, improving the product yield. Detailed Embodiments

[0082] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0083] As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or apparatus containing the listed elements is not necessarily limited to those elements, but may also include other elements not expressly listed or elements inherent to such composition, step, method, article or apparatus.

[0084] "Optionally", "alternatively" or "any one of" means that the matter or event described thereafter may or may not occur, and the description includes the case where the event occurs and the case where the event does not occur.

[0085] In the following specific embodiments of the present invention, the materials for which the preparation methods are not provided are all commercially available chemicals.

[0086] In the following specific embodiments of the present invention, the number-average molecular weight of the alkali-soluble resin is measured by gel permeation chromatography (GPC), and the acid value is measured according to the method in Standard GB / T 12008.5-2010.

[0087] The following will take multiple examples to detail the alkali-soluble resin and its preparation method described in the present invention, but the alkali-soluble resin and its preparation method described in the present invention are not limited to these examples.

[0088] Example 1

[0089] An alkali-soluble resin and its preparation method, the preparation method comprising the following steps:

[0090] (1) Mix bisphenol A epoxy resin (NPES-907, Nan Ya) and a solvent (diethylene glycol ethyl ether acetate) in a four-necked flask equipped with a condenser, so that the mass ratio of the epoxy resin to the solvent is 11:8. After heating to 90 °C to dissolve the epoxy resin, add a catalyst (tetraethylammonium bromide) thereto and mix evenly. Introduce nitrogen to make the reaction system in a nitrogen environment, and dropwise add acrylic acid dissolved with a phenolic inhibitor (2,6-di-tert-butyl-p-cresol) and ZJ-701 thereto. Control the dropping time to be 2 h. After the addition is completed, react at 105 °C for 6 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0091] The molar ratio of the epoxy group in the epoxy resin to acrylic acid is 1:1.03; based on the total mass of the epoxy resin and acrylic acid being 100%, the mass of the catalyst is 0.6%, and the masses of the phenolic inhibitor and ZJ-701 are 0.1% respectively;

[0092] (2) Add maleic anhydride to the prepolymer obtained in step (1). Based on the mass of the prepolymer being 100%, the mass of maleic anhydride is 26%; react at 105 °C for 4 h to obtain the alkali-soluble resin, the number-average molecular weight of which is 3500 and the acid value is 17 mgKOH / g.

[0093] Example 2

[0094] An alkali-soluble resin and a preparation method thereof, the preparation method comprising the following steps:

[0095] (1) In a four-necked flask equipped with a condenser, mix o-cresol novolac epoxy resin (CYDCN-208, Baling Petrochemical) with a solvent (diethylene glycol ethyl ether acetate) so that the mass ratio of the epoxy resin to the solvent is 5:6. After heating to 90 °C to dissolve the epoxy resin, add a catalyst (triphenylphosphine) thereto and mix evenly. Introduce nitrogen to make the reaction system in a nitrogen environment, and dropwise add acrylic acid dissolved with a phenolic inhibitor (2,6-di-tert-butyl-p-cresol) and ZJ-701 thereto, controlling the dropping time to 2 h. After the addition is completed, react at 105 °C for 6 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0096] The molar ratio of the epoxy group in the epoxy resin to acrylic acid is 1:1.03; based on the total mass of the epoxy resin and acrylic acid being 100%, the mass of the catalyst is 0.6%, and the masses of the phenolic inhibitor and ZJ-701 are 0.1% respectively;

[0097] (2) Add tetrahydrophthalic anhydride to the prepolymer obtained in step (1). Based on the mass of the prepolymer being 100%, the mass of tetrahydrophthalic anhydride is 37%; react at 105 °C for 4 h to obtain the alkali-soluble resin, the number average molecular weight of which is 2500 and the acid value is 77 mgKOH / g.

[0098] Example 3

[0099] An alkali-soluble resin and a preparation method thereof, the preparation method comprising the following steps:

[0100] (1) In a four-necked flask equipped with a condenser, mix dicyclopentadiene phenol epoxy resin (SQDN-305, Shengquan) with a solvent (diethylene glycol ethyl ether acetate) so that the mass ratio of the epoxy resin to the solvent is 1:1. After heating to 90 °C to dissolve the epoxy resin, add a catalyst (tetraethylammonium bromide) thereto and mix evenly. Introduce nitrogen to make the reaction system in a nitrogen environment, and dropwise add acrylic acid dissolved with a phenolic inhibitor (2,6-di-tert-butyl-p-cresol) and ZJ-701 thereto, controlling the dropping time to 2 h. After the addition is completed, react at 95 °C for 6 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0101] The molar ratio of the epoxy group in the epoxy resin to acrylic acid is 1:1.03; based on the total mass of the epoxy resin and acrylic acid being 100%, the mass of the catalyst is 0.6%, and the masses of the phenolic inhibitor and ZJ-701 are 0.1% respectively;

[0102] (2) Add tetrahydrophthalic anhydride to the prepolymer obtained in step (1). Based on the mass of the prepolymer being 100%, the mass of tetrahydrophthalic anhydride is 34%; react at 105 °C for 4 h to obtain the alkali-soluble resin, which has a number-average molecular weight of 2900 and an acid value of 72 mgKOH / g.

[0103] Example 4

[0104] An alkali-soluble resin and a preparation method thereof, the preparation method comprising the following steps:

[0105] (1) In a four-necked flask equipped with a condenser, mix dicyclopentadiene phenol-type epoxy resin (SQDN-305, Shengquan) with a solvent (diethylene glycol ethyl ether acetate) so that the mass ratio of the epoxy resin to the solvent is 1:1. After heating to 90 °C to dissolve the epoxy resin, add a catalyst (N,N-dimethylbenzylamine) and mix evenly. Introduce nitrogen to make the reaction system in a nitrogen environment, and dropwise add methacrylic acid dissolved with a phenolic inhibitor (2,6-di-tert-butyl-p-cresol) and ZJ-701. Control the dropping time to 2 h. After the addition is complete, react at 95 °C for 6 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0106] The molar ratio of the epoxy group in the epoxy resin to methacrylic acid is 1:1.03; based on the total mass of the epoxy resin and methacrylic acid being 100%, the mass of the catalyst is 0.6%, and the masses of the phenolic inhibitor and ZJ-701 are 0.1% respectively;

[0107] (2) Add tetrahydrophthalic anhydride and hexahydrophthalic anhydride to the prepolymer obtained in step (1). Based on the mass of the prepolymer being 100%, the mass of tetrahydrophthalic anhydride is 20%, and the mass of hexahydrophthalic anhydride is 21%; react at 105 °C for 4 h to obtain the alkali-soluble resin, which has a number-average molecular weight of 2900 and an acid value of 32 mgKOH / g.

[0108] Example 5

[0109] An alkali-soluble resin and a preparation method thereof, the preparation method comprising the following steps:

[0110] (1) Mix o-cresol novolac epoxy resin (NPES-907, South Asia) and a solvent (diethylene glycol ethyl ether acetate) in a four-necked flask equipped with a condenser tube, with the mass ratio of epoxy resin to solvent being 1:1. After heating to 90 °C to dissolve the epoxy resin, add a catalyst (N,N-dimethylbenzylamine) and mix evenly. Introduce nitrogen to make the reaction system in a nitrogen environment, and dropwise add methacrylic acid dissolved with a phenolic inhibitor (2,6-di-tert-butyl-p-cresol) and ZJ-701, controlling the dropping time to 2 h. After addition, react at 95 °C for 6 h until the acid value of the product ≤ 1 mg KOH / g to obtain a prepolymer;

[0111] The molar ratio of the epoxy groups in the epoxy resin to methacrylic acid is 1:1.03; based on the total mass of the epoxy resin and methacrylic acid being 100%, the mass of the catalyst is 0.6%, and the masses of the phenolic inhibitor and ZJ-701 are 0.1% respectively;

[0112] (2) Add tetrahydrophthalic anhydride and hexahydrophthalic anhydride to the prepolymer obtained in step (1). Based on the mass of the prepolymer being 100%, the mass of tetrahydrophthalic anhydride is 14% and the mass of hexahydrophthalic anhydride is 30%; React at 105 °C for 4 h to obtain the alkali-soluble resin, with its number-average molecular weight being 2900 and acid value being 20 mg KOH / g.

[0113] Hereinafter, the photosensitive resin composition of the present invention will be described in detail with multiple application examples, but the photosensitive resin composition of the present invention is not limited to these application examples.

[0114] Application Examples 1-5

[0115] A photosensitive resin composition includes the following components by mass parts:

[0116] 75 parts of alkali-soluble resin,

[0117] 2 parts of photoinitiator 1173,

[0118] 2 parts of photoinitiator 184,

[0119] 1 part of photoinitiator TPO-L,

[0120] 20 parts of isobornyl acrylate;

[0121] Among them, the alkali-soluble resin is the alkali-soluble resin provided in Examples 1-5 respectively.

[0122] The preparation method of the photosensitive resin composition is as follows: Mix all components according to the formula amount and dissolve them evenly to obtain the photosensitive resin composition.

[0123] Comparative Application Examples 1-2

[0124] A photosensitive resin composition, which is only different from that in Application Example 1 in that the alkali-soluble resins used are alkali-soluble phenolic resin (FPP-100, purchased from Shengquan) and alkali-soluble acrylic resin (PS-300, purchased from Sanqiu), and other materials and dosages are the same as those in Application Example 1.

[0125] Performance tests were carried out on the aforementioned photosensitive resin composition, and the specific contents are as follows:

[0126] The photosensitive resin composition to be tested was coated on a glass substrate using a film applicator to form a 30-μm wet film, and then cured in an ultraviolet light curing machine, where the radiation conditions of the UV curing machine were: mercury lamp 1000 W, wavelength 365 nm, radiation distance 15 cm, and radiation energy 600 mJ / cm 2 , to form a cured coating, and then developed in a developer (0.4% aqueous Na2CO3 solution). In order to test the overcoating performance, the photosensitive resin composition to be tested was continuously coated, cured, and developed on the already developed glass plate, and the above operations were repeated;

[0127] (1) Development ability: The cured coating was immersed in a 0.4% aqueous Na2CO3 solution, and the development clarity was used as a measure, and the development time was recorded at the same time;

[0128] (2) Hardness: The pencil hardness was tested according to the method in Standard GB / T 6739-2022;

[0129] (3) Minimum line width and line spacing: The test was carried out according to the method in the test of photosensitive imaging electroplating-resistant resist for printed boards in Standard GB / T 29846-2013;

[0130] (4) Overcoating deformability: After coating a layer of photosensitive resin composition, it was cured and developed according to the above sample preparation process, and then the coating, curing, and development were repeated 20 times to form 20 layers of cured and developed patterns. After drying, the degree of deformation was observed under a microscope. If there was no obvious deformation, it was recorded as "excellent"; if there was slight deformation, but the deformation degree < 1.5 times the size of the film, it was recorded as "good"; if there was obvious deformation, and the deformation degree ≥ 1.5 times the size of the film, it was recorded as "poor".

[0131] The test results are shown in Table 1:

[0132] Table 1

[0133]

[0134] According to the test data in Table 1, compared with Comparative Application Examples 1-2 using the existing alkali-soluble resin, through the design and co-action of raw materials and processes, the present invention obtains an alkali-soluble resin with more excellent performance. When used in a photosensitive resin composition, it can exhibit an excellent development effect, and a development process window with clear patterns can be achieved by rinsing with a 0.4% Na2CO3 aqueous solution for 30-45 s. The developed patterns are clear, with high graphic resolution, the minimum line width and line pitch ≤ 25 μm, good adhesion to the substrate, and high hardness. It is especially suitable for scenarios requiring laminated printing. No obvious deformation occurs after 20 layers of overcoating printing, effectively avoiding the problem of pattern deformation during multi-layer overcoating curing, and effectively improving the pattern quality.

[0135] The applicant declares that the present invention uses the above embodiments to illustrate the alkali-soluble resin of the present invention and its preparation method, the photosensitive resin composition and its application. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an alkali-soluble resin, characterized in that, The preparation method comprises the following steps: (1) Reacting an epoxy resin with an unsaturated monocarboxylic acid to obtain a prepolymer; (2) Reacting the prepolymer obtained in step (1) with an acid anhydride to obtain the alkali-soluble resin.

2. The preparation method according to claim 1, wherein The epoxy resin includes any one or a combination of at least two of bisphenol A epoxy resin, bisphenol F epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene phenol epoxy resin, and alicyclic epoxy resin; And / or, the unsaturated monocarboxylic acid includes any one or a combination of at least two of acrylic acid, crotonic acid, and methacrylic acid; And / or, the molar ratio of the epoxy group in the epoxy resin to the unsaturated monocarboxylic acid is 1:(1 - 1.1).

3. The preparation method according to claim 1, characterized in that, The reaction in step (1) is carried out in the presence of a catalyst; The catalyst includes any one or a combination of at least two of tetraethylammonium bromide, tetrabutylammonium bromide, triphenylphosphine, and N,N-dimethylbenzylamine; And / or, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the catalyst is 0.1 - 1%; And / or, the reaction in step (1) is carried out in the presence of an inhibitor; And / or, the inhibitor includes a phenolic inhibitor and / or a stable free radical inhibitor; And / or, based on the total mass of the epoxy resin and the unsaturated monocarboxylic acid being 100%, the mass of the inhibitor is 0.02 - 0.5%.

4. The preparation method according to claim 1, characterized in that, The temperature of the reaction in step (1) is 80 - 110 °C, and the time is 2 - 10 h.

5. The preparation method according to claim 1, characterized in that, The acid anhydride includes any one or a combination of at least two of maleic anhydride, norbornene dicarboxylic anhydride, itaconic anhydride, acrylic anhydride, methacrylic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride; And / or, based on the mass of the prepolymer being 100%, the mass of the acid anhydride is 20 - 40%; And / or, the temperature of the reaction in step (2) is 80 - 110 °C, and the time is 1 - 8 h.

6. An alkali-soluble resin, characterized in that, The alkali-soluble resin is prepared by the preparation method according to any one of claims 1 - 5.

7. A photosensitive resin composition, characterized in that, The photosensitive resin composition includes a combination of the alkali-soluble resin according to claim 6, a photoinitiator, and a photosensitive monomer.

8. The photosensitive resin composition according to claim 7, characterized in that, The photosensitive resin composition comprises the following components by mass parts: 60 - 85 parts of alkali-soluble resin, 0.1 - 8 parts of photoinitiator, 10 - 40 parts of photosensitive monomer; And / or, the photoinitiator includes any one or a combination of at least two of ethyl 2,4,6-trimethylbenzoyl phenylphosphinate, bis(4-methylphenyl)-2,4,6-trimethylbenzoylphosphine oxide, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, benzoin dimethyl ether, and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide; And / or, the photosensitive monomer includes any one or a combination of at least two of isooctyl (meth)acrylate, isobornyl (meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetrahydrofuran (meth)acrylate.

9. A photosensitive silver paste, characterized in that, The photosensitive silver paste includes silver powder and the photosensitive resin composition as described in claim 7 or 8.

10. Application of a photosensitive silver paste as described in claim 9 in a chip multilayer inductor or a flexible circuit board.

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