Photosensitive resin composition, photosensitive dry film, cured film, circuit board and LED display module

Abstract

The invention provides a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board and an LED display module. The photosensitive resin composition comprises the following components in parts by weight: 15-40 parts of acrylic resin containing carboxyl, 1-20 parts of epoxy resin and 0.5-5 parts of a photoinitiator, wherein the epoxy resin comprises epoxy resin containing phosphate groups. According to the photosensitive resin composition disclosed by the invention, through the synergistic effect of the components, the balance of the photosensitive resin composition in a crosslinking process is favorably improved, and the crosslinking density of the photosensitive resin composition is improved, so that the flowability and the sealing property of the photosensitive resin are favorably improved; further, the formation of a stable, yellowing-resistant, cracking-resistant and high-reflectivity photosensitive dry film after the photosensitive resin is cured is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board and an LED display module. BACKGROUND

[0002] In recent years, with the continuous development of smart phones, tablet computers, notebook computers, televisions, automobiles, Internet of Things and other devices, the LCD display technology applied thereto is also constantly updated. At present, advanced display technologies represented by mini LED and Micro LED are developing rapidly. The design and manufacture of related circuit boards are also evolving towards diversification and thinness of substrates. In order to reflect LED light as much as possible at a lower energy consumption to improve the luminous efficiency, a photosensitive resin composition containing inorganic fillers can be used to realize the photosensitive dry film or the glue solution in the related solder resist and packaging materials.

[0003] The photosensitive dry film prepared by the prior art usually uses an acrylate resin and a high volume concentration of inorganic fillers, resulting in poor adhesion. Therefore, it is necessary to develop a photosensitive resin composition glue solution or dry film with high reflectivity, yellowing resistance, anti-cracking property and good adhesion to the substrate, which is used for solder resist, packaging and other needs on the circuit board. SUMMARY

[0004] The main purpose of the present application is to provide a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board and an LED display module, so as to solve the problems of poor yellowing resistance, easy cracking and poor adhesion to the substrate of the photosensitive dry film in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a photosensitive resin composition is provided, which comprises, in parts by weight: 15-40 parts of a carboxyl-containing acrylate resin, 1-20 parts of an epoxy resin and 0.5-5 parts of a photoinitiator; wherein the epoxy resin comprises an epoxy resin containing a phosphate group.

[0006] Further, the structure general formula of the epoxy resin containing a phosphate group is:

[0007] wherein m and n are positive integers, and 1≤m≤3, 1≤n≤3; the is the structure after ring opening of part of the epoxy groups in the epoxy resin, preferably the epoxy resin is selected from any one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin and hydrogenated bisphenol F type epoxy resin, and R is the corresponding aromatic skeleton or aliphatic skeleton of the epoxy resin.

[0008] Further, the carboxyl group-containing acrylate resin is selected from any one or more of a carboxyl group-containing acrylate resin, a carboxyl group-containing epoxy acrylate resin, a carboxyl group-containing polyurethane acrylate resin, a carboxyl group-containing polyester acrylate resin, and a carboxyl group-containing polyether acrylate resin; and / or, the double bond equivalent of the carboxyl group-containing acrylate resin is 200 to 800 g / mol, preferably 300 to 500 g / mol; and / or, the molecular weight of the carboxyl group-containing acrylate resin is 10,000 to 50,000, preferably 10,000 to 30,000; and / or, the carboxyl group-containing acrylate resin is 20 to 35 parts by weight.

[0009] Further, the epoxy resin is 5 to 10 parts by weight; and / or, the epoxy resin further includes an unmodified epoxy resin selected from any one or more of a glycidyl ether type epoxy resin, an alicyclic type epoxy resin, and an oxetane type epoxy resin; wherein the glycidyl ether type epoxy resin is selected from any one or more of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol aldehyde type epoxy resin, an o-cresol type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a hydrogenated bisphenol F type epoxy resin, an aliphatic type epoxy resin, and a heterocyclic type epoxy resin.

[0010] Further, the ratio of the total number of epoxy groups in the phosphoric acid ester group-containing epoxy resin and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl group-containing acrylate resin is 0.5 to 1.6: 1, preferably 0.8 to 1.2: 1.

[0011] Further, the photoinitiator is 3 to 5 parts by weight, and the photoinitiator is selected from any one or more of benzoin, a benzoin derivative, an alkylbenzophenone compound, an acylphosphine oxide, a benzophenone compound, a thioxanthone compound, an oxime ester compound, and a titanocene compound; and / or, the photosensitive resin composition further includes 1 to 15 parts by weight of an active polymerization monomer containing a terminal carbon-carbon double bond, preferably 5 to 15 parts by weight; preferably the active polymerization monomer is selected from any one or more of a monofunctional (meth)acrylate monomer, a difunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a multifunctional (meth)acrylate monomer; and / or, the photosensitive resin composition further includes 30 to 70 parts by weight of a white filler selected from any one or more of titanium white, zinc oxide, zinc barium white, and lead white.

[0012] According to another aspect of the present application, there is provided a photosensitive dry film formed by sequentially applying and drying the photosensitive resin composition described above.

[0013] According to still another aspect of the present application, there is provided a cured film formed by curing the photosensitive dry film described above.

[0014] According to still another aspect of the present application, there is provided a circuit board including the cured film described above.

[0015] According to still another aspect of the present application, there is provided an LED display module including the cured film described above.

[0016] The technical scheme of the present application provides a photosensitive resin composition, wherein the carboxyl-containing acrylate resin is the main resin, and the carboxyl group in the molecular structure of this part of the resin can improve the cracking resistance of the film layer and its adhesion to the substrate through photo-polymerization during exposure and chemical reaction during subsequent thermal curing. Meanwhile, the epoxy resin containing phosphate groups included in the present application can form a chemical bond with the substrate based on the -OH group contained in the phosphate group in the epoxy resin, which is beneficial to improving the adhesion of the photosensitive dry film. On the other hand, the phosphate in the epoxy resin can produce a phosphate passivation film, which not only has good flame retardant effect, but also is beneficial to improving the yellowing resistance. Through the synergistic effect of the above components, it is beneficial to improve the balance of the photosensitive resin composition during cross-linking, and to improve the cross-linking density of the photosensitive resin composition, thereby improving the flowability and adhesion of the photosensitive resin, and further forming a stable, yellowing-resistant, cracking-resistant and high-reflectivity photosensitive dry film after curing. Thus, the photosensitive dry film obtained by the present application is suitable for solder mask, packaging and other needs on the circuit board. DETAILED DESCRIPTION

[0017] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0018] As analyzed in the background art of the present application, the photosensitive dry film in the prior art has the problems of poor yellowing resistance, easy cracking and poor adhesion to the substrate. In order to solve the above problems, the present application provides a photosensitive resin composition, a photosensitive dry film, a cured film, a circuit board and an LED display module.

[0019] In a typical embodiment of the present application, a photosensitive resin composition is provided, which includes, in parts by weight: 15-40 parts of a carboxyl-containing acrylate resin, 1-20 parts of an epoxy resin and 0.5-5 parts of a photoinitiator; wherein the epoxy resin includes an epoxy resin containing a phosphate group.

[0020] The present application provides a photosensitive resin composition, wherein the carboxyl-containing acrylate resin is the main resin, and the carboxyl group in the molecular structure of the resin can improve the crack resistance of the film layer and its adhesion to the substrate through photo-polymerization during exposure and subsequent chemical reaction during thermal curing. Meanwhile, the present application includes an epoxy resin containing phosphate groups, which is beneficial to improve the adhesion of the photosensitive dry film based on the principle that the -OH group in the phosphate group in the epoxy resin forms a chemical bond with the substrate. On the other hand, the phosphate group in the epoxy resin can produce a phosphate passivation film, which not only has good flame retardant effect, but also is beneficial to improve the yellowing resistance. Through the synergistic effect of the above components, it is beneficial to improve the balance of the photosensitive resin composition during crosslinking, and to improve the crosslinking density of the photosensitive resin composition, thereby improving the flowability and adhesion of the photosensitive resin, and further forming a stable, yellowing-resistant, crack-resistant and high-reflectivity photosensitive dry film after curing, thereby making the photosensitive dry film obtained by the present application suitable for solder mask, packaging and other needs on the circuit board.

[0021] In an embodiment of the present application, the structure general formula of the above-mentioned epoxy resin containing phosphate groups is:

[0022] wherein m and n are positive integers, and 1≤m≤3, 1≤n≤3; the is the structure after ring opening of part of the epoxy groups in the epoxy resin, preferably the epoxy resin is selected from any one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, and hydrogenated bisphenol F type epoxy resin, and R is the corresponding aromatic skeleton or aliphatic skeleton of the epoxy resin.

[0023] By limiting the structure general formula of the epoxy resin containing phosphate groups, and by controlling the range of m and n and controlling the mass fraction of the phosphate group in the epoxy resin containing phosphate groups within the above range, it is beneficial to fully exert the effect of the -OH group and the phosphate passivation film in the epoxy resin containing phosphate groups. Preferably, the partial structure in the epoxy resin containing phosphate groups is controlled within the above range, which is beneficial to promote the exertion of the effect of the epoxy resin containing phosphate groups.

[0024] Preferably, the epoxy resin containing phosphate groups is selected from the following compounds:

[0025]

[0026] Preparation of the epoxy resin containing phosphate group: the epoxy resin and acetone were added into a four-necked flask equipped with a stirrer, a thermometer and a condenser, the stirring was started and the temperature was slowly increased until the epoxy resin was completely dissolved, the temperature was increased to 75-85℃ and the stirring was maintained (300 rpm); the phosphoric acid with a mass fraction of 85% was slowly added through a constant pressure dropping funnel, the dropping speed was controlled so that the temperature of the system was not more than 100℃, the dropping time was ≥1 hour, the molar ratio of the epoxy resin and the phosphoric acid was 2:1, after the addition was completed, the reaction temperature was maintained at 60-80℃, and the reaction was ended when the measured epoxy value was not changed any more; after the reaction was ended, the acetone and water were removed by distillation under reduced pressure, and the epoxy resin containing phosphate group was prepared.

[0027] In an embodiment of the present application, the carboxyl-containing acrylate resin is selected from any one or more of a carboxyl-containing acrylate resin, a carboxyl-containing epoxy acrylate resin, a carboxyl-containing polyurethane acrylate resin, a carboxyl-containing polyester acrylate resin and a carboxyl-containing polyether acrylate resin; and / or, the double bond equivalent of the carboxyl-containing acrylate resin is 200-800 g / mol, preferably 300-500 g / mol; and / or, the molecular weight of the carboxyl-containing acrylate resin is 10000-50000, preferably 10000-30000; and / or, the carboxyl-containing acrylate resin is 20-35 parts by weight.

[0028] Preferably, the type of the carboxyl-containing acrylate resin and the range of the double bond equivalent and the molecular weight are controlled, which is beneficial to improve the balance of the photosensitive resin in the crosslinking process, thereby improving the overall crosslinking density of the resist film, and is also beneficial to improve the flowability and adhesion of the photosensitive resin, thereby improving the photopolymerization performance and thermal curing stability of the photosensitive resin. Preferably, the parts by weight of the carboxyl-containing acrylate resin is controlled within the above range, which is beneficial to the carboxyl-containing acrylate resin playing a leading role in the photosensitive resin and producing a synergistic effect with other components, thereby being beneficial to forming a dry film with good yellowing resistance and anti-cracking property.

[0029] In an embodiment of the present application, the epoxy resin is 5-10 parts by weight; and / or, the epoxy resin further comprises an unmodified epoxy resin, the unmodified epoxy resin is selected from any one or more of a glycidyl ether type epoxy resin, an alicyclic type epoxy resin and an oxetane type epoxy resin; wherein the glycidyl ether type epoxy resin is selected from any one or more of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol aldehyde type epoxy resin, an ortho-cresol type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a hydrogenated bisphenol F type epoxy resin, an aliphatic type epoxy resin and a heterocyclic type epoxy resin.

[0030] Preferably, the epoxy resin further comprises an unmodified epoxy resin, the addition of the unmodified epoxy resin is helpful to provide additional epoxy groups, thereby cooperating with the epoxy resin containing phosphate group.

[0031] In one embodiment of the present application, the ratio of the total number of epoxy groups in the unmodified epoxy resin and the unmodified epoxy resin containing phosphate groups to the number of carboxyl groups in the carboxyl-containing acrylate resin is 0.5-1.6:1, preferably 0.8-1.2:1.

[0032] The unmodified epoxy resin in the present application provides additional epoxy groups. By controlling the total number of epoxy groups in the unmodified epoxy resin and the unmodified epoxy resin containing phosphate groups within the above range, the synergistic effect of the unmodified epoxy resin and the epoxy resin containing phosphate groups is improved, which helps to promote the reaction between the epoxy groups and the carboxyl groups in the carboxyl-containing acrylate resin, forming a more dense crosslinked network, and thus improving the mechanical strength and thermal stability of the dry film. Therefore, by controlling the range of the above conditions, the adhesion and adhesion of the film layer to various substrates are improved.

[0033] In one embodiment of the present application, the above-mentioned photoinitiator is 3-5 parts by weight, and the photoinitiator is selected from any one or more of benzoin and its derivatives, alkylbenzophenone compounds, acyl phosphine oxides, benzophenone compounds, thioxanthone compounds, oxime ester compounds and titanocene compounds.

[0034] The photoinitiator generates free radicals under the irradiation of ultraviolet light, and can initiate the free radical polymerization of the acrylate resin and the active polymerization monomer. Preferably, the content of the photoinitiator is controlled within the above range, which is beneficial to improve the sufficiency and controllability of the free radical polymerization reaction. Preferably, the type of photoinitiator is controlled within the above range, which is beneficial to efficiently initiate the polymerization reaction under lower energy ultraviolet light irradiation, reducing energy consumption and improving production efficiency.

[0035] Specifically, the above-mentioned photoinitiator is preferably selected from any one or more of benzoin, benzoin derivatives, alkylbenzophenone compounds, benzophenone compounds, thioxanthone compounds, oxime ester compounds and titanocene compounds; further, the benzoin is benzoin, and the benzoin derivative is preferably selected from any one or more of benzoin dimethyl ether, benzoin isopropyl ether and benzoin butyl ether; the alkylbenzophenone compound is preferably selected from any one or more of α,α-diethoxyacetophenone, α-hydroxyalkylbenzophenone and α-amine alkylbenzophenone; the benzophenone compound is preferably selected from any one or more of benzophenone, 2,4-dihydroxybenzophenone and Michler's ketone; the thioxanthone compound is preferably selected from any one or more of thioxanthone propoxy and isopropyl thioxanthone; the oxime ester compound is preferably selected from any one or more of OXE-1 and OXE-2; and the titanocene compound is preferably a titanocene compound 784.

[0036] In an embodiment of the present application, the above-mentioned photosensitive resin composition further comprises 1-15 parts by weight of a terminal carbon-carbon double bond-containing active polymerization monomer, preferably 5-15 parts by weight; preferably the active polymerization monomer is selected from any one or more of monofunctional (meth)acrylate monomers, difunctional (meth)acrylate monomers, trifunctional (meth)acrylate monomers, and polyfunctional (meth)acrylate monomers.

[0037] Preferably, the type of terminal carbon-carbon double bond-containing active polymerization monomer is controlled to be within the above-mentioned range, which is beneficial to improving the flowability, filling property and flexibility after curing of the photosensitive resin composition. By controlling the content of the terminal carbon-carbon double bond-containing active polymerization monomer to be within the above-mentioned range, the performance of the photosensitive resin composition is improved, thereby improving the structural compactness and reflectivity of the dry film.

[0038] Specifically, preferably the above-mentioned active polymerization monomer is selected from any one or more of (ethoxylated) phenol (meth)acrylate, stearic acid acrylate, ethoxylated (propoxylated) nonyl phenol (meth)acrylate, ethoxylated (propoxylated) tetrahydrofurfuryl (meth)acrylate, 1,6-hexanediol diacrylate, tricyclodecane dimethanol diacrylate, dioxane diol diacrylate, ethoxylated (propoxylated) bisphenol A di(meth)acrylate, polyethylene glycol (400) diacrylate, polypropylene glycol (600) diacrylate, ethoxylated (propoxylated) trimethylolpropane tri(meth)acrylate, pentaerythritol triacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, dipentaerythritol hexaacrylate, ethoxylated pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

[0039] In an embodiment of the present application, the above-mentioned photosensitive resin composition further comprises 30-70 parts by weight of a white filler, the white filler being selected from any one or more of titanium white, zinc oxide, zinc barytes, and lead white; the photosensitive resin composition further comprises 0.1-5 parts by weight of other auxiliary fillers, the other auxiliary fillers being selected from any one or more of reinforcing fillers, color developing agents, plasticizers, defoaming agents, polymerization inhibitors, leveling agents, dispersants, and antioxidants.

[0040] The addition of white fillers is advantageous for improving the optical properties of the dry film, allowing it to achieve high reflectivity at lower thicknesses. The addition of other auxiliary fillers is advantageous for reducing the oxidative degradation of the photosensitive resin composition during storage and processing, while also facilitating the uniform dispersion of the photosensitive resin composition, thereby improving the long-term stability and uniform dispersion of the dry film. Preferably, the content of the white fillers and other auxiliary fillers is controlled within the above ranges, not only to meet the performance requirements of the photosensitive resin composition, but also to reduce the impact on the flowability of the photosensitive resin composition. The photosensitive resin composition of the present application is suitable for different colors of inorganic fillers. For compositions containing white fillers, the adhesion is poorer due to the large amount of white fillers added, therefore, the addition of epoxy resins containing phosphate groups helps to better improve the adhesion, while also reducing yellowing.

[0041] Specifically, preferably the above reinforcing fillers are selected from any one or more of barium sulfate, silicon dioxide, talc, calcium carbonate. Preferably the above color developing agents are selected from any one or more of amyl bromide, ethylene dibromide, benzyl bromide, dibromomethane, tribromomethyl phenyl sulfone, trichloroacetamide, amyl iodide, hexachloroethane. The above plasticizers are selected from any one or more of phthalic acid-based compounds or sulfonamide-based compounds. Preferably the above plasticizers are selected from any one or more of diethyl phthalate, diphenyl phthalate, p-toluenesulfonamide. Preferably the above defoamers are selected from any one or more of non-silicon type defoamers, polyether type defoamers, silicone type defoamers, polyether modified silicone type defoamers. Preferably the above polymerization inhibitors are selected from any one or more of p-methoxyphenol, hydroquinone, pyrogallol, t-butyl catechol, N-nitroso phenyl hydroxylamine aluminum salt. Preferably the above leveling agents include high molecular weight dispersants such as polycarboxylic acid-based, naphthalene sulfonic acid formaldehyde condensation-based, polyethylene glycol, polyalkyl ester of polycarboxylic acid-based, polyether-based, polyalkylene polyamine-based, etc., low molecular weight dispersants such as alkyl sulfonic acid-based, quaternary ammonium-based, higher alcohol alkylene oxide-based, polyhydric alcohol ester-based, alkyl polyamine-based, etc. Preferably the above dispersants are selected from any one or more of acid-containing compounds such as phosphate esters, acid group-containing copolymers, hydroxyl group-containing polybasic acid esters, polysiloxanes, salts of long chain polyaminoamides and acid esters. Preferably the above antioxidants are selected from any one or more of amine-based antioxidants, phenolic antioxidants, thioester auxiliary antioxidants, phosphite auxiliary antioxidants, sulfide auxiliary antioxidants.

[0042] Specifically, the above-mentioned photosensitive resin composition can also contain an organic solvent for preparing the composition and adjusting the viscosity. The organic solvent includes, but is not limited to, ketone solvents such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, tetramethylbenzene, etc.; glycol ether solvents such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether, etc.; ester solvents such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, propylene carbonate, etc.; aliphatic hydrocarbon solvents such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha.

[0043] In another typical embodiment of the present application, a photosensitive dry film is provided, which is formed by coating and drying a photosensitive resin composition, wherein the photosensitive resin composition is the above-mentioned photosensitive resin composition.

[0044] The photosensitive dry film formed by coating and drying the photosensitive resin composition of the present application has high reflectivity, yellowing resistance, cracking resistance, and good adhesion to the substrate. The coating method includes, but is not limited to, screen printing, roller coating, spraying, and gravure coating.

[0045] In another typical embodiment of the present application, a cured film is provided, which is formed by curing a photosensitive dry film, wherein the photosensitive dry film is the above-mentioned photosensitive dry film.

[0046] The cured film formed by photo-curing and thermal curing of the above-mentioned photosensitive dry film not only has high reflectivity and yellowing resistance, but also has significantly enhanced adhesion to the circuit board substrate, and is suitable for the needs of solder mask and packaging of precision circuit boards. The curing includes photo-curing, thermal curing, or photo-thermal dual curing.

[0047] In another typical embodiment of the present application, a circuit board is provided, which comprises a cured film, wherein the cured film is the above-mentioned cured film.

[0048] The circuit board comprising the above-mentioned cured film has good electrical insulation performance.

[0049] In another typical embodiment of the present application, an LED display module is provided, which comprises a cured film, wherein the cured film is the above-mentioned cured film.

[0050] The LED display module comprising the above-mentioned cured film has good reliability and stability.

[0051] The beneficial effects of the present application will be further illustrated in the following examples.

[0052] Example 1

[0053] Preparation of bisphenol A epoxy resin containing phosphate group: 100 parts by weight of bisphenol A type epoxy resin (Nippon Kayaku NPEL-128E) and 30 parts by weight of acetone were added into a four-necked flask equipped with a stirrer, a thermometer and a condenser, the stirring was started and the temperature was slowly increased until the epoxy resin was completely dissolved, the temperature was increased to 80°C and the stirring was maintained (300 rpm). 30 parts by weight of 85% phosphoric acid was slowly added through a constant pressure dropping funnel, the dropping speed was controlled so that the temperature of the system did not exceed 100°C, the dropping time was 1 h; after the addition was completed, the reaction temperature was maintained at 70°C, and the reaction was completed when the measured epoxy value did not change any more; after the reaction was completed, acetone and water were removed by distillation under reduced pressure, and a bisphenol A epoxy resin containing phosphate group with the following chemical structure was prepared:

[0054]

[0055] Preparation of photosensitive dry film: 25 parts by weight of carboxyl-containing acrylate resin (Daiso CYCLOMER P(ACA) Z250, Mw 22000, double bond equivalent weight 380), 5 parts by weight of epoxy resin containing phosphate group, 5 parts by weight of active polymerizable monomer ethoxylated trimethylolpropane triacrylate (BASF Laromer LR8863), 3 parts by weight of photoinitiator acylphosphine oxide (IGM Omnirad TPO), 40 parts by weight of rutile titanium dioxide (Ishihara CR-90) and 2 parts by weight of auxiliary agent (BYK-163) were uniformly dispersed using a high-speed disperser, and the particle size was controlled to be below 10 μm by three-roll milling to obtain a photosensitive resin composition.

[0056] The photosensitive resin composition was coated on a carrier layer by roll coating, and then the solvent contained therein was dried to obtain a photosensitive film layer with a thickness of 40 μm. The photosensitive layer was laminated with a copper-clad plate substrate by a vacuum laminator, and then the photosensitive layer was exposed and developed to obtain the desired pattern. The photosensitive dry film was obtained by heating at 150°C for 1 h.

[0057] Example 2

[0058] The difference from Example 1 is that 40 parts by weight of carboxyl-containing acrylate resin (Daiso CYCLOMER P(ACA) Z250), 8.5 parts by weight of epoxy resin containing phosphate group, 12 parts by weight of acrylate monomer (BASF Laromer LR8863), 5 parts by weight of photoinitiator (IGM Omnirad TPO), 70 parts by weight of rutile titanium dioxide (Ishihara CR-90) and 1 part by weight of auxiliary agent (BYK-163) were uniformly dispersed using a high-speed disperser, and the particle size was controlled to be below 10 μm by three-roll milling to obtain a photosensitive resin composition, and finally a photosensitive dry film was obtained.

[0059] Example 3

[0060] The difference from Example 1 is that 15 parts of carboxyl group-containing acrylate resin (Cyclo MER P (ACA) Z250), 3 parts of phosphonate group-containing epoxy resin, 2 parts of active polymerization monomer ethoxylated trimethylolpropane triacrylate (Laromer LR8863), 1.5 parts of photoinitiator acyl phosphine oxide (IGM Ommirad TPO), 30 parts of rutile titanium dioxide (Ishihara CR-90), and 0.5 parts of auxiliary agent (BYK-163) are uniformly dispersed by using a high-speed disperser, and the particle size is controlled to be below 10 μm by a three-roll mill to obtain a photosensitive resin composition, and finally a photosensitive dry film is obtained.

[0061] Example 4

[0062] The difference from Example 1 is that the epoxy resin is the phosphonate group-containing bisphenol A epoxy resin (2 parts by weight) in Example 1 and the unmodified bisphenol A epoxy resin E51 (Nanya NPEL-128E) (0.35 parts by weight), and the ratio of the total number of epoxy groups in the phosphonate group-containing epoxy resin and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl group-containing acrylate resin is 0.5:1, and finally a photosensitive dry film is obtained.

[0063] Example 5

[0064] The difference from Example 1 is that the epoxy resin is the phosphonate group-containing bisphenol A epoxy resin (2 parts by weight) in Example 1 and the unmodified bisphenol A epoxy resin E51 (Nanya NPEL-128E) (1.14 parts by weight), and the ratio of the total number of epoxy groups in the phosphonate group-containing epoxy resin and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl group-containing acrylate resin is 0.8:1, and finally a photosensitive dry film is obtained.

[0065] Example 6

[0066] The difference from Example 1 is that the epoxy resin is the phosphonate group-containing bisphenol A epoxy resin (2 parts by weight) in Example 1 and the unmodified bisphenol A epoxy resin E51 (Nanya NPEL-128E) (3.24 parts by weight), and the ratio of the total number of epoxy groups in the phosphonate group-containing epoxy resin and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl group-containing acrylate resin is 1.6:1, and finally a photosensitive dry film is obtained.

[0067] Example 7

[0068] The difference from Example 1 is that the epoxy resin is the phosphonate group-containing bisphenol A epoxy resin (1 part by weight) in Example 1 and unmodified bisphenol A type epoxy resin E51 (Nitto Epoxy Resin Co., Ltd. NPEL-128E) (0.3 part by weight), and the ratio of the total number of epoxy groups in the phosphonate group-containing epoxy resin and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl group-containing acrylate-based resin is 0.3: 1, and a photosensitive dry film is finally obtained.

[0069] Example 8

[0070] The difference from Example 1 is that 25 parts of a carboxyl group-containing acrylate-based resin (Cyclo MER P (ACA) Z254F), 7 parts of a phosphonate group-containing epoxy resin, 5 parts of an active polymerization monomer dipentaerythritol acrylate (Sartomer SR-899), 3 parts of a photoinitiator acylphosphine oxide (BASF Irgacure 819), 40 parts of a filler rutile titanium white (Ishihara CR-50), and 2 parts of an auxiliary BYK-111 are uniformly dispersed by using a high-speed disperser, and the particle size is controlled to be below 10 μm by a three-roll mill, to obtain a photosensitive resin composition, and a photosensitive dry film is finally obtained. 819), 40 parts of a filler rutile titanium white (Ishihara CR-50), and 2 parts of an auxiliary BYK-111 are uniformly dispersed by using a high-speed disperser, and the particle size is controlled to be below 10 μm by a three-roll mill, to obtain a photosensitive resin composition, and a photosensitive dry film is finally obtained.

[0071] Example 9

[0072] The difference from Example 1 is that 100 parts by weight of a bisphenol F epoxy resin is used for synthesis to obtain a phosphonate group-containing bisphenol F epoxy resin having the following structural formula, and a photosensitive dry film is finally obtained.

[0073]

[0074] Example 10

[0075] The difference from Example 1 is that 100 parts by weight of a hydrogenated bisphenol A epoxy resin is used for synthesis to obtain a phosphonate group-containing hydrogenated bisphenol A epoxy resin having the following structural formula, and a photosensitive dry film is finally obtained.

[0076]

[0077] Comparative Example 1

[0078] The difference from Example 1 is that 25 parts of a carboxyl-containing acrylate resin (Daiso CYCLOMER P(ACA) Z250), 2.5 parts of a bisphenol A type epoxy resin E51 (Nippon Epoxy NPEL-128E), 5 parts of an active polymerization monomer ethoxylated trimethylolpropane triacrylate (BASF Laromer LR8863), 3 parts of a photoinitiator acyl phosphine oxide (IGM Omnirad TPO), 30 parts of rutile titanium white (Ishihara CR-90), and 2 parts of an auxiliary agent (BYK-163) are uniformly dispersed using a high-speed disperser, and the particle size is controlled to be below 10 μm by a three-roll mill to obtain a photosensitive resin composition, and finally a photosensitive dry film is obtained.

[0079] Comparative Example 2

[0080] The difference from Example 1 is that 25 parts of a carboxyl-containing acrylate resin (Daiso CYCLOMER P(ACA) Z250), 2.5 parts of a bisphenol A type epoxy resin E51 (Nippon Epoxy NPEL-128E), 5 parts of an active polymerization monomer ethoxylated trimethylolpropane triacrylate (BASF Laromer LR8863), 3 parts of a photoinitiator acyl phosphine oxide (IGM Omnirad TPO), 30 parts of rutile titanium white (Ishihara CR-90), and 2 parts of an auxiliary agent (BYK-163) are uniformly dispersed using a high-speed disperser, and the particle size is controlled to be below 10 μm by a three-roll mill to obtain a photosensitive resin composition, and finally a photosensitive dry film is obtained.

[0081] Performance test:

[0082] Reflectance test: Using a spectrophotometer (Konika-Minota CM-26d), 5 points on the surface of the test sample were randomly selected under the conditions of 6500K color temperature and 10° observation window, and the SCI reflectance at 460 nm wavelength was measured, and the average value was taken as the result.

[0083] Adhesion test: A 10x10 grid pattern was drawn on the surface of the film using a cross-cut knife, and the scratches should be deep into the substrate. Using 3M tape, paste and pull up vertically, and observe the number of grids that do not fall off the film surface.

[0084] Anti-yellowing test: After placing the sample in a hot air circulating oven at 250°C for 3 min, using a spectrophotometer (Konika-Minota CM-26d), 5 points on the surface of the test sample were randomly selected under the conditions of 6500K color temperature and 10° observation window, and the SCI reflectance at 460 nm wavelength was measured, and the average value was taken as the result.

[0085] The photosensitive dry films of the above examples and comparative examples were tested for performance, and the results are shown in Table 1.

[0086] Table 1

[0087]

[0088] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects:

[0089] The present application provides a photosensitive resin composition, wherein the carboxyl-containing acrylate resin is the main resin, and the molecular structure of this part of the resin contains carboxyl groups, which can improve the anti-cracking property of the film layer and its adhesion to the substrate through photo-polymerization during the exposure process and chemical reaction during the subsequent heat curing process. Meanwhile, the present application includes an epoxy resin containing phosphate groups, which is based on the principle that the -OH groups contained in the phosphate groups in the epoxy resin form chemical bonds with the substrate, which is beneficial to improve the adhesion of the photosensitive dry film. On the other hand, the phosphate groups in the epoxy resin can produce a phosphate passivation film, which not only has good flame retardant effect, but also is beneficial to improve the yellowing resistance. Through the synergistic effect of the above components, it is beneficial to improve the balance of the photosensitive resin composition during the crosslinking process, and to improve the crosslinking density of the photosensitive resin composition, thereby improving the flowability and adhesion of the photosensitive resin, and further forming a stable, yellowing-resistant, anti-cracking and high-reflectivity photosensitive dry film after curing of the photosensitive resin, thereby making the photosensitive dry film obtained by the present application suitable for solder mask, packaging and other needs on the circuit board.

[0090] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A photosensitive resin composition, characterized by comprising: The photosensitive resin composition comprises, in parts by weight: 15-40 parts of a carboxyl-containing acrylate resin; 1-20 parts of an epoxy resin; and 0.5-5 parts of a photoinitiator; The epoxy resin comprises an epoxy resin containing a phosphate group.

2. The photosensitive resin composition according to claim 1, characterized by The structure general formula of the epoxy resin containing a phosphate group is: wherein m and n are positive integers, and 1≤m≤3, 1≤n≤3; the phosphoric acid ester group-containing epoxy resin is a structure after ring opening of part of the epoxy groups in an epoxy resin, preferably the epoxy resin is selected from any one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, and R is an aromatic skeleton or an aliphatic skeleton corresponding to the epoxy resin.

3. The photosensitive resin composition according to claim 1 or 2, characterized by The carboxyl-containing acrylate resin is selected from any one or more of a carboxyl-containing acrylate resin, a carboxyl-containing epoxy acrylate resin, a carboxyl-containing polyurethane acrylate resin, a carboxyl-containing polyester acrylate resin, and a carboxyl-containing polyether acrylate resin; And / or, the double bond equivalent of the carboxyl-containing acrylate resin is 200-800 g / mol, preferably 300-500 g / mol; And / or, the molecular weight of the carboxyl-containing acrylate resin is 10,000-50,000, preferably 10,000-30,000; and / or, the carboxyl-containing acrylate resin is 20-35 parts by weight.

4. The photosensitive resin composition according to any one of claims 1 to 3, characterized by The epoxy resin is 5-10 parts by weight; and / or, the epoxy resin further comprises an unmodified epoxy resin selected from any one or more of a glycidyl ether type epoxy resin, an alicyclic type epoxy resin, and an oxetane type epoxy resin; wherein the glycidyl ether type epoxy resin is selected from any one or more of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol aldehyde type epoxy resin, an ortho-cresol type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a hydrogenated bisphenol F type epoxy resin, an aliphatic type epoxy resin, and a heterocyclic type epoxy resin.

5. The photosensitive resin composition according to any one of claims 1 to 4, characterized by The ratio of the total number of epoxy groups in the epoxy resin containing a phosphate group and the unmodified epoxy resin to the number of carboxyl groups in the carboxyl-containing acrylate resin is 0.5-1.6:1, preferably 0.8-1.2:

1.

6. The photosensitive resin composition according to any one of claims 1 to 5, characterized by The photoinitiator is 3-5 parts by weight, and the photoinitiator is selected from any one or more of benzoin, benzoin derivatives, alkylbenzophenone compounds, acylphosphine oxides, benzophenone compounds, thioxanthone compounds, oxime ester compounds, and titanocene compounds; And / or, the photosensitive resin composition further comprises 1-15 parts by weight of an active polymerization monomer containing a terminal carbon-carbon double bond, preferably 5-15 parts by weight; preferably the active polymerization monomer is selected from any one or more of a monofunctional (meth)acrylate monomer, a difunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a multifunctional (meth)acrylate monomer; And / or, the photosensitive resin composition further comprises 30-70 parts by weight of a white filler selected from any one or more of titanium white, zinc oxide, zinc white, and lead white.

7. A photosensitive dry film, formed by sequentially coating and drying a photosensitive resin composition, characterized in that, The photosensitive resin composition is the photosensitive resin composition of any one of claims 1-6.

8. A cured film formed by curing a photosensitive dry film, characterized by, The photosensitive dry film is the photosensitive dry film of claim 7.

9. A wiring board comprising a cured film, characterized by, The cured film is the cured film of claim 8.

10. An LED display module comprising a cured film, characterized in that, The cured film is the cured film of claim 8.

Images