Low-temperature curing resin and photosensitive resin composition containing the same

Abstract

The present invention discloses a low-temperature curing resin, which is an acrylate polymer containing at least four copolymerized units: A, B, C, and D. A photosensitive resin composition containing the low-temperature curing resin is also disclosed. The low-temperature curing resin and photosensitive resin composition of the present invention can be cured at relatively low temperatures, and the cured coating film exhibits high hardness, heat resistance, and water resistance. Furthermore, the composition can be formed into high-definition patterns using photolithography.

Description

Technical Field

[0001] The present invention relates to the field of photosensitive chemical materials, and in particular to a low-temperature curing resin and a photosensitive resin composition containing the low-temperature curing resin. Background Art

[0002] In the display industry, photoresist materials are often used in the manufacturing process of display panels. To fully cure the photoresist, a high post-baking temperature is often required. For example, in the LCD display panel manufacturing process, a high temperature of 200-230°C is generally used for post-baking to ensure that the material is fully cured.

[0003] With the development of new display technologies such as OLED and Micro-LED, the demand for photoresists suitable for these new display technologies is increasing. However, many materials used in these new display technologies (such as flexible substrates and luminescent materials) are generally not resistant to high temperatures. Therefore, photoresists must be able to cure at low temperatures of 80-100°C while maintaining good mechanical properties and material reliability after curing.

[0004] Currently, some photoresists in related fields on the market often have the problem of insufficient low-temperature curing, resulting in low hardness and low adhesion, affecting the stability of the display structure; there are also some materials that can achieve low-temperature curing, but the film layer formed has poor density and strong hydrophilicity, resulting in poor oxygen and water barrier capabilities of the material, causing problems such as bottom metal circuit corrosion during subsequent reliability testing.

[0005] Therefore, it is necessary to develop a photosensitive material that can form good and stable fine patterns through the photolithography process, can achieve low-temperature curing, and has excellent mechanical properties and reliability of the pattern after curing. Summary of the Invention

[0006] The object of the present invention is to provide a low-temperature curing resin.

[0007] The present invention also provides a photosensitive resin composition containing a low-temperature curing resin.

[0008] The innovation of the present invention lies in the low-temperature curing resin and photosensitive resin composition, which can be cured at a relatively low temperature, and the cured coating film has high hardness, heat resistance and water resistance; at the same time, the composition can be formed into high-precision patterns through photolithography.

[0009] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is:

[0010] A low-temperature curing resin, which is an acrylate polymer and contains at least four copolymerized unit structures of A, B, C, and D;

[0011] The copolymerization unit A has the structural formula (I):

[0012] Formula (I)

[0013] Among them, R 1 is a methyl group or a hydrogen atom,

[0014] R2 contains or The structure of the group,

[0015] m is an integer from 0 to 20;

[0016] The copolymerization unit B has the structural formula (II):

[0017] Formula (II) Among them, R 3 is a methyl group or a hydrogen atom;

[0018] The copolymerization unit C has a structural formula as shown in formula (III):

[0019] Formula (III)

[0020] Among them, R 4 is a methyl group or a hydrogen atom,

[0021] R 5 、R 6 、R 7 are methoxy or ethoxy, respectively,

[0022] n is an integer from 0 to 20;

[0023] The copolymerization unit D has a structural formula as shown in formula (IV):

[0024] Formula (IV)

[0025] Among them, R 8 、R 10 are methyl or hydrogen atoms,

[0026] R 9 A group of -CH2- or -CH2O- structure,

[0027] p is an integer from 0 to 20.

[0028] Furthermore, the molar percentage of copolymer unit A in the four copolymer units A, B, C, and D is 30-65%, the molar percentage of copolymer unit B is 5-20%, the molar percentage of copolymer unit C is 20-50%, and the molar percentage of copolymer unit D is 5-25%.

[0029] Furthermore, the weight average molecular weight of the resin is 2,000 to 20,000.

[0030] A photosensitive resin composition containing a low-temperature curing resin comprises the following raw materials in percentage by mass: 15-50% of a low-temperature curing resin, 10-60% of a photopolymerizable compound, 5-15% of a photopolymerization initiator, 10-50% of an epoxy compound, and 3-10% of a curing agent.

[0031] Further, the photopolymerizable compound includes one or more of methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-1,2-ethylene glycol acrylate, ethylene glycol methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, triethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane triacrylate, tetra(trimethylolpropane)tetraacrylate, tetra(trimethylolpropane)tetramethacrylate, pentaerythritol monoacrylate, pentaerythritol monomethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, polydipentaerythritol pentaacrylate, polydipentaerythritol pentamethacrylate, polydipentaerythritol hexaacrylate, polydipentaerythritol hexamethacrylate, and 1,6-hexanediol diacrylate.

[0032] Furthermore, the photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is

[0033] The molecular formula of X is

[0034] R 11 is phenyl, C1-C20 alkyl, -CN, -NO2 or C1-C4 haloalkyl, R 12 is a C2-C12 alkyl group or a C4-C8 acyl group, R 13 ~R 17 are H, halogen atoms, C1-C12 alkyl, phenyl or C6H5S-, R 18 、R 19 are H, a halogen atom, a C1-C12 alkyl group or a phenyl group.

[0035] Furthermore, the epoxy compound is an epoxy resin containing more than two epoxy groups in a single molecule, including one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin and novolac epoxy resin.

[0036] Furthermore, the curing agent is one or more of a phenolic resin curing agent, an acid anhydride curing agent, an amine curing agent and a thiol curing agent.

[0037] Furthermore, the amine curing agent is one or more curing agents containing primary amine, secondary amine, tertiary amine and imidazole structures.

[0038] The beneficial effects of the present invention are:

[0039] 1. The low-temperature curing resin and photosensitive resin composition of the present invention, through the addition of epoxy groups to the low-temperature curing resin and compounding, can achieve low-temperature curing at 80-100°C. The photosensitive resin composition can also be formed into high-definition patterns through photolithography processes. The resulting patterns and coatings have high hardness and strong adhesion. Furthermore, the addition of siloxane structures to the resin groups imparts high water resistance to the patterns and coatings, effectively preventing corrosion of the underlying metal circuits. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0041] Example 1: A low-temperature curing resin, which is an acrylate-type polymer, and the resin contains four copolymer unit structures A, B, C, and D; the molar percentage of copolymer unit A among the four copolymer units A, B, C, and D is 30%, the molar percentage of copolymer unit B is 20%, the molar percentage of copolymer unit C is 25%, and the molar percentage of copolymer unit D is 25%; the weight-average molecular weight of the resin is 8,000 to 10,000.

[0042] The copolymerization unit A has the structural formula (I):

[0043] Formula (I)

[0044] Among them, R 1 is methyl,

[0045] R2 contains The structure of the group,

[0046] m is 0;

[0047] The copolymerization unit B has the structural formula (II):

[0048] Formula (II) Among them, R 3 is methyl;

[0049] The copolymer unit C has the structural formula (III):

[0050] Formula (III)

[0051] Among them, R 4 is methyl, R 5 、R6 、R 7 is a methoxy group, n is 0;

[0052] The copolymerized unit D has the structural formula (IV):

[0053] Formula (IV)

[0054] Among them, R 8 、R 10 is methyl, R 9 It is a group with a -CH2 structure, and p is 0.

[0055] Example 2: A low-temperature curing resin, which is an acrylate type polymer, and the resin contains four copolymer unit structures A, B, C, and D; the molar percentage of copolymer unit A among the four copolymer units A, B, C, and D is 65%, the molar percentage of copolymer unit B is 5%, the molar percentage of copolymer unit C is 20%, and the molar percentage of copolymer unit D is 10%; the weight-average molecular weight of the resin is 2500 to 4000.

[0056] The copolymerization unit A has the structural formula (I):

[0057] Formula (I)

[0058] Among them, R 1 is a hydrogen atom,

[0059] R2 contains The structure of the group,

[0060] m is 10;

[0061] The copolymerization unit B has the structural formula (II):

[0062] Formula (II) Among them, R 3 is a hydrogen atom;

[0063] The copolymer unit C has the structural formula (III):

[0064] Formula (III)

[0065] Among them, R 4 is a hydrogen atom, R 5 、R 6 、R 7 is ethoxy, n is 10;

[0066] The copolymerized unit D has the structural formula (IV):

[0067] Formula (IV)

[0068] Among them, R 8 、R 10 is a hydrogen atom, R 9 It is a group of -CH2O- structure, and p is 10.

[0069] Example 3: A low-temperature curing resin, which is an acrylate type polymer, and the resin contains four copolymer unit structures A, B, C, and D; the molar percentage of copolymer unit A among the four copolymer units A, B, C, and D is 35%, the molar percentage of copolymer unit B is 10%, the molar percentage of copolymer unit C is 50%, and the molar percentage of copolymer unit D is 5%; the weight-average molecular weight of the resin is 6000-8000.

[0070] The copolymerization unit A has the structural formula (I):

[0071] Formula (I)

[0072] Among them, R 1 is methyl,

[0073] R2 contains The structure of the group,

[0074] m is 20;

[0075] The copolymerization unit B has the structural formula (II):

[0076] Formula (II) Among them, R 3 is methyl;

[0077] The copolymer unit C has the structural formula (III):

[0078] Formula (III) Among them, R 4 is a hydrogen atom, R 5 、R 6 、R 7 is methoxy, R 6 、R 7 is an ethoxy group, n is 20; the copolymerized unit D has a structural formula as shown in formula (IV):

[0079] Formula (IV) Among them, R 8 is methyl, R 10 is a hydrogen atom, R 9 It is a group with a -CH2 structure, and p is 20.

[0080] Example 4: A low temperature curing resin, the resin is an acrylate type polymer, the resin contains four copolymer units A, B, C, D and The unit structure of the group; the molar percentage of the copolymerization unit A is 30%, the molar percentage of the copolymerization unit B is 10%, the molar percentage of the copolymerization unit C is 20%, and the molar percentage of the copolymerization unit D is 20%, The molar percentage of the group structure is 20%; and the weight average molecular weight of the resin is 18,000 to 20,000.

[0081] The copolymerization unit A has the structural formula (I):

[0082] Formula (I)

[0083] Among them, R 1 is a hydrogen atom,

[0084] R2 contains The structure of the group,

[0085] m is an integer of 15;

[0086] The copolymerization unit B has the structural formula (II):

[0087] Formula (II) Among them, R 3 is a hydrogen atom;

[0088] The copolymer unit C has the structural formula (III):

[0089] Formula (III) Among them, R 4 is a hydrogen atom, R 5 、R 6 , is methoxy, R 7 is an ethoxy group, n is an integer of 5; the copolymerized unit D has a structural formula as shown in formula (IV):

[0090] Formula (IV) Among them, R 8 is a hydrogen atom, R 10 is methyl, R 9 It is a group of -CH2O- structure, and p is an integer of 6.

[0091] Example 5

[0092] Example 5: Referring to Example 1, the copolymerization unit A has the structural formula of formula (I):

[0093] Formula (I)

[0094] Among them, R 1 is a methyl group or a hydrogen atom,

[0095] R2 contains or The structure of the group,

[0096] m is an integer from 0 to 20;

[0097] The copolymerization unit B has the structural formula (II):

[0098] Formula (II) Among them, R 3 is a methyl group or a hydrogen atom;

[0099] The copolymer unit C has the structural formula (III):

[0100] Formula (III)

[0101] Among them, R 4 is a methyl group or a hydrogen atom,

[0102] R 5 、R 6 、R 7 are methoxy or ethoxy, respectively,

[0103] n is an integer from 0 to 20;

[0104] The copolymerized unit D has the structural formula (IV):

[0105] Formula (IV)

[0106] Among them, R 8 、R 10 are methyl or hydrogen atoms,

[0107] R 9 A group of -CH2- or -CH2O- structure,

[0108] p is an integer from 0 to 20.

[0109] The copolymerized unit A structure can be formed by copolymerizing one or more monomers selected from the group consisting of glycidyl methacrylate, glycidyl acrylate, 3,4-epoxycyclohexyl methyl methacrylate, and 3,4-epoxycyclohexyl methyl acrylate.

[0110] The copolymerized unit B structure can be formed by copolymerizing one or more monomers of methacrylic acid and acrylic acid.

[0111] The copolymer unit C structure can be formed by copolymerizing one or more of the monomers (trimethoxysilyl)propyl methacrylate, (trimethoxysilyl)propyl acrylate, (trimethoxysilyl)butyl methacrylate, (trimethoxysilyl)butyl acrylate, (trimethoxysilyl)pentyl methacrylate, (trimethoxysilyl)pentyl acrylate, (trimethoxysilyl)hexyl methacrylate, (trimethoxysilyl)hexyl acrylate, (triethoxysilyl)propyl methacrylate, (triethoxysilyl)propyl acrylate, (triethoxysilyl)butyl methacrylate, (triethoxysilyl)butyl acrylate, (triethoxysilyl)pentyl methacrylate, (triethoxysilyl)pentyl acrylate, (triethoxysilyl)hexyl methacrylate, and (triethoxysilyl)hexyl acrylate. The copolymer unit D structure can be formed by the following reaction: first, copolymerization reaction is carried out with one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxybutyl methacrylate, and hydroxybutyl acrylate to form structure, and then methacrylic acid or acrylic acid is used to react with the hydroxyl group in the structure to form a copolymer unit D structure through an esterification reaction.

[0112] Comparative Example 1: Referring to Example 1, the copolymerization unit A is replaced by the following structural formula:

[0113]

[0114] Comparative Example 2: Referring to Example 1, the copolymerization unit C is replaced by the following structural formula:

[0115]

[0116] Example 6: A photosensitive resin composition, characterized in that it comprises the following raw materials in percentage by mass: 15% of the low-temperature curing resin of Example 1, 10% of a photopolymerizable compound, 15% of a photopolymerization initiator, 50% of an epoxy compound, and 10% of a curing agent.

[0117] The photopolymerizable compound is methyl acrylate;

[0118] The photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is

[0119] The molecular formula of X is

[0120] , R 11 is phenyl, R 12 is a C2-C12 alkyl group, R 13 ~R 17 H, R18 、R 19 is H. The epoxy compound is an epoxy resin containing two epoxy groups in a single molecule, which is a bisphenol A type epoxy resin;

[0121] The curing agent is a phenolic resin curing agent;

[0122] Example 7: A photosensitive resin composition, characterized in that it comprises the following raw materials in percentage by mass: 50% of the low-temperature curing resin of Example 2, 32% of a photopolymerizable compound, 5% of a photopolymerization initiator, 10% of an epoxy compound, and 3% of a curing agent.

[0123] The photopolymerizable compound is polydipentaerythritol hexaacrylate;

[0124] The photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is

[0125] The molecular formula of X is R 11 is a C1-C20 alkyl group, R 12 is a C4-C8 acyl group, R 13 ~R 17 is a halogen atom, R 18 、R 19 is a halogen atom;

[0126] The epoxy compound is an epoxy resin containing three epoxy groups in a single molecule, which is a bisphenol F type epoxy resin;

[0127] The curing agent is an anhydride curing agent;

[0128] Example 8: A photosensitive resin composition, characterized in that it comprises the following raw materials in percentage by mass: 17% of the low-temperature curing resin of Example 3, 60% of a photopolymerizable compound, 6% of a photopolymerization initiator, 13% of an epoxy compound, and 4% of a curing agent.

[0129] The photopolymerizable compound is pentaerythritol tetraacrylate;

[0130] The photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is

[0131] The molecular formula of X is

[0132] , R 11 -CN, R 12 is a C2-C12 alkyl group, R 13 ~R 17 is a C1-C12 alkyl group, R 18 、R 19 is a C1-C12 alkyl group;

[0133] Epoxy compounds are epoxy resins containing more than 4 epoxy groups in a single molecule, and are biphenyl-type epoxy resins;

[0134] The curing agent is an amine curing agent containing a tertiary amine structure;

[0135] Example 9: Referring to Example 6, the photopolymerizable compound includes one or more of methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-1,2-ethylene glycol acrylate, ethylene glycol methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, triethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane triacrylate, tetra(trimethylolpropane)tetraacrylate, tetra(trimethylolpropane)tetramethacrylate, pentaerythritol monoacrylate, pentaerythritol monomethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, polydipentaerythritol pentaacrylate, polydipentaerythritol pentamethacrylate, polydipentaerythritol hexaacrylate, polydipentaerythritol hexamethacrylate, and 1,6-hexanediol diacrylate.

[0136] The photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is

[0137] The molecular formula of X is

[0138] R 11 is phenyl, C1-C20 alkyl, -CN, -NO2 or C1-C4 haloalkyl, R 12 is a C2-C12 alkyl group or a C4-C8 acyl group, R 13 ~R 17 are H, halogen atoms, C1-C12 alkyl, phenyl or C6H5S-, R 18 、R 19 are H, a halogen atom, a C1-C12 alkyl group or a phenyl group.

[0139] The epoxy compound is an epoxy resin containing two or more epoxy groups in a single molecule, including one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin and novolac epoxy resin.

[0140] The curing agent is one or more of a phenolic resin curing agent, an acid anhydride curing agent, an amine curing agent and a thiol curing agent.

[0141] The amine curing agent is one or more curing agents containing primary amine, secondary amine, tertiary amine and imidazole structures.

[0142] Comparative Example 3: Referring to Example 7, the resin was replaced by the resin used in Comparative Example 1.

[0143] Comparative Example 4: Referring to Example 7, the resin was replaced by the resin used in Comparative Example 2.

[0144] <Aperture Resolution Evaluation>

[0145] The photosensitive resin composition was coated on a glass substrate using a spin coater (1H-36S: produced by Mikasa), dried on a 90°C baking plate for 2 minutes to form a coating film, and exposed with a mask using a scanning mercury lamp exposure machine (MPA-400: produced by Canon, Japan). The mask contained circular shading areas with apertures of 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 μm, thereby forming circular openings of corresponding diameters on the substrate; exposure was performed with an exposure energy of 80 mj / cm2; after exposure, development was performed by spraying with a TMAH (tetramethylammonium hydroxide) developer with a concentration of 2.38% for 60 seconds, and then baked in an 85°C oven for 60 minutes.

[0146] Using an optical microscope (BX51TRF, Olympus), the substrate's circular aperture area was observed, starting from the smallest aperture and progressing to the largest. The aperture resolution value corresponding to the smallest aperture diameter, where the aperture is circular and free of residual material, is determined. Lower aperture resolution indicates greater ease in fabricating finer patterns using the composite.

[0147] <Pencil Hardness Evaluation>

[0148] The photosensitive resin composition was applied onto a glass substrate using a spin coater (1H-36S: manufactured by Mikasa), dried on a baking sheet at 90°C for 2 minutes to form a coating film, and then fully exposed using a scanning mercury lamp exposure machine (MPA-400: manufactured by Canon, Japan) at an irradiation dose of 80 mj / cm2. The film was then baked in an oven at 85°C for 60 minutes to form a cured film with a thickness of 2 μm.

[0149] The pencil hardness of the cured film was tested using the GB / T6739 method to obtain the pencil hardness evaluation results.

[0150] <Adhesion Evaluation>

[0151] The photosensitive resin composition was applied onto a glass substrate using a spin coater (1H-36S: manufactured by Mikasa), dried on a baking sheet at 90°C for 2 minutes to form a coating film, and then fully exposed using a scanning mercury lamp exposure machine (MPA-400: manufactured by Canon, Japan) at an irradiation dose of 80 mj / cm2. The film was then baked in an oven at 85°C for 60 minutes to form a cured film with a thickness of 2 μm.

[0152] After using a grid cutter to cut a grid on the cured film, the film was placed in a high-temperature, high-humidity chamber (EHS-211M, manufactured by ESPEC) for 24 hours at 120°C / 100% RH / 2 atm. Following the test, a grid cutter adhesion test was performed according to GB / T 9286-1998. The test grade is the adhesion evaluation result.

[0153] <Heat Resistance Evaluation>

[0154] The photosensitive resin composition was applied onto a glass substrate using a spin coater (1H-36S: manufactured by Mikasa), dried on a baking sheet at 90°C for 2 minutes to form a coating film, and then fully exposed using a scanning mercury lamp exposure machine (MPA-400: manufactured by Canon, Japan) at an irradiation dose of 80 mj / cm2. The film was then baked in an oven at 85°C for 60 minutes to form a cured film with a thickness of 2 μm.

[0155] Heat resistance was evaluated using a TG-DTA (TG8121, Rigaku). The coating was scraped into a powder and loaded into the TGA apparatus. A nitrogen atmosphere was introduced and the temperature was raised to 400°C at a rate of 10°C / min. The temperature at which 5% weight loss was measured was used as the heat resistance evaluation standard. The higher the 5% weight loss temperature, the better the heat resistance of the coating.

[0156] <Water barrier evaluation>

[0157] The photosensitive resin composition was applied to the PI film using a rotary coater (1H-36S: manufactured by Mikasa), dried on a 90°C baking plate for 2 minutes to form a coating film, and then fully exposed using a scanning mercury lamp exposure machine (MPA-400: manufactured by Canon, Japan) with an irradiation dose of 80 mj / cm2. The film was then baked in an oven at 85°C for 60 minutes to form a cured film with a thickness of 2 μm.

[0158] The water vapor transmission value (WVT) of the coating is tested using the GB / T 1037-2021 method. The lower the WVT value, the better the water barrier properties of the coating.

[0159] The above evaluation method was used to evaluate the compositions in the examples and comparative examples. The results are shown in the following table.

[0160]

[0161] As can be seen from the above table, the low-temperature curing resin obtained in the embodiment is used for the photosensitive resin composition, which can form a high-precision pattern through the photolithography process. At the same time, the coating film formed has obvious advantages in hardness, adhesion, heat resistance and water resistance.

[0162] The embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Claims

1. A low-temperature curing resin, characterized in that The resin is an acrylate type polymer, and the resin contains at least four copolymer unit structures of A, B, C, and D; The copolymerization unit A has the structural formula (I): Formula (I) , Among them, R 1 is a methyl group or a hydrogen atom, R 2 To contain or The structure of the group, m is an integer from 0 to 20; The copolymerization unit B has the structural formula of formula (II): Formula (II) , where R 3 is a methyl group or a hydrogen atom; The copolymer unit C has a structural formula as shown in formula (III): Formula (III) , Among them, R 4 is a methyl group or a hydrogen atom, R 5 、R 6 、R 7 are methoxy or ethoxy, respectively, n is an integer from 0 to 20; The copolymerized unit D has a structural formula as shown in formula (IV): Formula (IV) ; Among them, R 8 、R 10 are methyl or hydrogen atoms, R 9 A group of -CH2- or -CH2O- structure, p is an integer from 0 to 20; Among the four copolymer units A, B, C, and D, the molar percentage of copolymer unit A is 30-65%, the molar percentage of copolymer unit B is 5-20%, the molar percentage of copolymer unit C is 20-50%, and the molar percentage of copolymer unit D is 5-25%.

2. The low-temperature curing resin according to claim 1, characterized in that The weight average molecular weight of the resin is 2500-20000.

3. A photosensitive resin composition containing the low-temperature curing resin according to claim 1 or 2, characterized in that: The invention comprises the following raw materials in percentage by mass: 15-50% of low-temperature curing resin, 10-60% of photopolymerization compound, 5-15% of photopolymerization initiator, 10-50% of epoxy compound and 3-10% of curing agent.

4. The photosensitive resin composition of low-temperature curing resin according to claim 3, characterized in that: The photopolymerizable compound includes one or more of methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 1,2-ethylene glycol 2-acrylate, ethylene glycol methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane triacrylate, tetra(trimethylolpropane)tetraacrylate, tetra(trimethylolpropane)tetramethacrylate, pentaerythritol monoacrylate, pentaerythritol monomethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, polydipentaerythritol pentaacrylate, polydipentaerythritol pentamethacrylate, polydipentaerythritol hexaacrylate, polydipentaerythritol hexamethacrylate, and 1,6-hexanediol diacrylate.

5. The photosensitive resin composition of low-temperature curing resin according to claim 3, characterized in that: The photopolymerization initiator contains an oxime ester photoinitiator, the general formula of which is , where the molecular formula of X is ; or , R 11 is phenyl, C1-C20 alkyl, -CN, -NO2 or C1-C4 haloalkyl, R 12 is a C4-C8 acyl group, R 13 ~R 17 are H, halogen atoms, C1-C12 alkyl, phenyl or C6H5S-, R 18 、R 19 are H, a halogen atom, a C1-C12 alkyl group or a phenyl group.

6. The photosensitive resin composition of low-temperature curing resin according to claim 3, characterized in that: The epoxy compound is an epoxy resin containing two or more epoxy groups in a single molecule, including one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, biphenyl epoxy resin and novolac epoxy resin.

7. The photosensitive resin composition of low-temperature curing resin according to claim 3, characterized in that: The curing agent is one or more of a phenolic resin curing agent, an acid anhydride curing agent, an amine curing agent and a thiol curing agent.

8. The photosensitive resin composition of low-temperature curing resin according to claim 7, characterized in that: The amine curing agent is one or more curing agents containing primary amine, secondary amine, tertiary amine and imidazole structures.

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