阅读说明：本技术 基于双马来酰亚胺/丙烯酸液晶光敏树脂的组合物及其在405nm 3D打印中的应用 (Bismaleimide/acrylic acid liquid crystal photosensitive resin-based composition and application thereof in 405nm3D printing ) 是由 卓东贤 陈少云 华文强 孙晓露 陈明雪 瞿波 王睿 郑燕玉 刘小英 李文杰 于 2021-09-28 设计创作，主要内容包括：本发明公开了基于双马来酰亚胺/丙烯酸液晶光敏树脂的组合物及其在405nm 3D打印中的应用。按重量计,将10～50份双马来酰亚胺基光敏树脂、10～50份丙烯酸液晶光敏树脂、10～50份丙烯酸类树脂、0～25份聚乙二醇二甲基丙烯酸酯类树脂、0～25份烷氧化丙烯酸酯、0～25份稀释剂、0.1～10份光引发剂、0～5份消泡剂、0～5份流平剂和0～5份抗氧化剂混合制得可用于405nm 3D打印的组合物。本发明提供的丙基于双马来酰亚胺/丙烯酸液晶光敏树脂的组合物可打印性好,具有打印复杂结构的能力；同时保留了双马来酰亚胺光敏树脂和丙烯酸液晶光敏树脂组合物的特性,所打印出的制品耐热性优异,机械性能良好,可广泛应用于精细电子器件、航空航天等领域。(The invention discloses a bismaleimide/acrylic liquid crystal photosensitive resin-based composition and application thereof in 405nm3D printing. According to the weight, 10-50 parts of bismaleimide-based photosensitive resin, 10-50 parts of acrylic liquid crystal photosensitive resin, 10-50 parts of acrylic resin, 0-25 parts of polyethylene glycol dimethacrylate resin, 0-25 parts of alkoxylated acrylate, 0-25 parts of diluent, 0.1-10 parts of photoinitiator, 0-5 parts of defoaming agent, 0-5 parts of flatting agent and 0-5 parts of antioxidant are mixed to prepare the composition for 405nm3D printing. The composition of propyl-bismaleimide/acrylic liquid crystal photosensitive resin provided by the invention has good printability and the capability of printing a complex structure; meanwhile, the characteristics of the bismaleimide photosensitive resin and the acrylic liquid crystal photosensitive resin composition are kept, and the printed product has excellent heat resistance and good mechanical property, and can be widely applied to the fields of fine electronic devices, aerospace and the like.)

1. A bismaleimide/acrylic liquid crystal photosensitive resin-based composition is characterized in that: the raw materials are as follows by weight:

2. the bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the preparation method of the bismaleimide resin comprises the following steps:

(1) mixing 100 parts of bismaleimide and 100-200 parts of aromatic diamine as raw materials in terms of mole, adding an organic solvent and 0-2 parts of catalyst 3, and reacting at 40-80 ℃ for 1-3 hours to obtain a solution A1;

(2) removing the organic solvent by vacuum concentration to obtain solution B1;

(3) adding 0-1 part of catalyst 4 and 0-0.5 part of polymerization inhibitor 1 into the solution B1 in terms of mole, slowly dropwise adding 100-400 parts of glycidyl methacrylate, and reacting at 50-70 ℃ for 4-12 hours to obtain bismaleimide resin;

wherein the bismaleimide is N, N '-1, 3-phenylene bismaleimide, 4' -diphenylmethane bismaleimide or a combination thereof; the aromatic diamine is 4,4 '-diaminodiphenylmethane, p-phenylenediamine, 2' -dimethyl-4, 4 '-diaminobiphenyl, 4' -diaminodiphenyl ether or a combination thereof; the organic solvent is acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate or acetonitrile; the catalyst 3 in the step (1) is glacial acetic acid or zinc chloride;

the catalyst 4 in the step (3) is tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride; the polymerization inhibitor 1 is hydroquinone.

3. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the preparation method of the acrylic liquid crystal photosensitive resin comprises the following steps:

(1) mixing 10 parts of mesomorphic-containing compound with-OH at the end, 50-500 parts of epoxy chloropropane and 0.1-1.0 part of catalyst 1 serving as raw materials in terms of mole, and introducing N₂Protecting, and then reacting for 5-24 hours at 40-100 ℃ to obtain a solution A2;

(2) slowly dripping 20-50 parts of NaOH solution into the solution A2 in terms of mole, removing water generated by the reaction under reduced pressure by using a vacuum pump, continuously reacting for 0.1-4 hours, pouring the product into a separating funnel, filtering to remove NaCl, and removing redundant epoxy chloropropane from the obtained filtrate by using a rotary evaporator to obtain a solution B2;

(3) mixing the solution B2 with a methanol/acetone solution, cooling, precipitating, washing the obtained crystal with methanol, filtering, and drying the product to obtain liquid crystal epoxy resin C;

(4) taking 10 parts of liquid crystal epoxy resin C and 0.1-1.0 part of polymerization inhibitor 2 by mol, adding the mixture into a flask, setting the reaction temperature to be 90-150 ℃, slowly dripping 20-25 parts of acrylic acid after the epoxy resin C is completely melted, dripping 0.01-0.1 part of catalyst 2, reacting for 0.5-5.0 hours, and cooling to obtain acrylic liquid crystal photosensitive resin;

wherein the compound containing mesomorphic elements and having-OH at the end is one or the combination of 4-hydroxyphenyl 4-hydroxybenzoate, 4 '-biphenol, 3',5,5 '-tetramethyl biphenol, 4- ((4-hydroxyphenoxy) carbonyl) phenyl 4-hydroxybenzoate, 2, 3-bis (4-hydroxyphenyl) acrylonitrile and 4,4' -propylidene biphenol; the catalyst 1 in the step (1) is one or a combination of tetramethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride; the polymerization inhibitor 2 in the step (4) is one or a combination of hydroquinone, benzoquinone, methylhydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone and 2, 5-di-tert-butylhydroquinone; the catalyst 2 in the step (4) is one or a combination of N, N-diethylaniline, N-dimethyl-p-toluidine, N-dimethylbenzylamine, N-dimethylcyclohexylamine, N '-dimethylpyridine and N, N' -diethylpiperazine.

4. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the polyurethane acrylate resin is selected from at least one of aliphatic polyurethane acrylate oligomer, aromatic polyurethane acrylate oligomer, polyurethane diacrylate and dimethyl acrylic urethane resin;

the polymerization degree of the polyethylene glycol dimethacrylate resin is 1-200.

5. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the alkoxylated acrylate monomer is at least one selected from glycerol oxide triacrylate and ethoxylated pentaerythritol tetraacrylate.

6. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the diluent is at least one selected from styrene, acrylate diluent, acrylic hydroxy ester diluent, vinyl ether diluent and cyclohexane diluent; the acrylate diluent is at least one selected from methyl methacrylate, 1, 6-hexanediol diacrylate, isobornyl acrylate, tetrahydrofuran acrylate, tripropylene glycol diacrylate, hexanediol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, isobornyl acrylate and cyclic trimethylolpropane formal acrylate; the acrylate diluent is at least one selected from hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxyethyl acrylate; the vinyl ether diluent is selected from at least one of 4-hydroxybutyl vinyl ether and diethylene glycol divinyl ether; the cyclohexane diluent is selected from at least one of 4-vinyl cyclohexene oxide and 4-vinyl cyclohexene oxide.

7. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the photoinitiator is diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluoroantimonate, diphenyl- (4-phenyl sulfur) phenyl sulfonium hexafluorophosphate, 4-octyloxy diphenyl iodonium hexafluoroantimonate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, diphenyl iodonium hexafluorophosphate, 4-isopropyl-4' -methyl diphenyl iodonium tetrakis (pentafluorophenyl) borate, triphenyl sulfonium tetrafluoroborate, tri-p-tolyl sulfonium hexafluorophosphate, 1-hydroxy-cyclohexyl-acetophenone, alpha-dimethyl-alpha-hydroxyacetophenone, p-isopropylphenyl-2-hydroxydimethyl acetone-1, benzophenone chloride, acrylated benzophenone, 4-phenylbenzophenone, 2-thioxanthone chloride, methyl-ethyl-4-phenyl-iodonium hexafluorophosphate, methyl-4-phenyl-1-hydroxy-iodonium hexafluorophosphate, methyl-phenyl-2-hydroxy-dimethyl-1-phenyl-benzophenone, methyl-ethyl-2-chloro-thioxanthone, methyl-ethyl-methyl-4-phenyl-1-iodonium hexafluorophosphate, methyl-4-phenyl-iodonium hexafluorophosphate, methyl-2-iodonium hexafluorophosphate, methyl-4-methyl-iodonium hexafluorophosphate, methyl-2-methyl-4-iodonium hexafluorophosphate, methyl-2-methyl-2-one, methyl-ethyl, At least one of isopropyl thioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, dimethyl thioxanthone, diethyl thioxanthone, dichlorothioxanthone, 2-phenylbenzyl-2-dimethylamine-1- (4-morpholinebenzylphenyl) butanone.

8. The bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to claim 1, wherein: the defoaming agent is at least one of silicone defoaming agent, mineral oil defoaming agent, polyether defoaming agent and fatty alcohol defoaming agent;

the flatting agent is selected from at least one of acrylic flatting agents, organic silicon flatting agents and fluorocarbon flatting agents;

the antioxidant is selected from at least one of pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxy) phenylpropionate, tris (2, 4-di-tert-butyl) phenyl phosphite, N' -bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine and 2, 6-di-tert-butyl-4-methylphenol.

9. The method for preparing the bismaleimide/acrylic liquid crystal photosensitive resin-based composition according to any one of claims 1 to 8, wherein: mixing bismaleimide resin, acrylic liquid crystal photosensitive resin, polyurethane acrylate resin, polyethylene glycol dimethacrylate resin, alkoxylated acrylate, a diluent, a defoaming agent, a leveling agent and an antioxidant, heating to 30-100 ℃, stirring and mixing uniformly, cooling, adding a photoinitiator, and stirring uniformly to obtain the high-performance acrylic resin.

10. Use of the bismaleimide/acrylic liquid crystal photosensitive resin based composition according to one of claims 1 to 81, wherein: the composition is used for 405nm photocuring 3D printing to obtain a formed part, and the formed part is subjected to ultraviolet light post-treatment, wherein the light intensity of ultraviolet light is 100W/cm²The ultraviolet curing time is 0-10 minutes, and the ultraviolet curing is carried out for 0-120 minutes after the ultraviolet curing is carried out at 100-250 ℃ under the vacuum condition.

Technical Field

The invention relates to the field of photosensitive resin processing and application thereof, in particular to a bismaleimide/acrylic liquid crystal photosensitive resin-based composition and application thereof in 405nm3D printing.

Background

In recent years, 3D printing technology is in a high-speed development stage, attracting more and more researchers. Compared with the traditional manufacturing method, 3D printing does not need to use a mold, and the production period and the cost of industrial products can be effectively reduced. With the development of 3D printing technology, the printing technology has more applications in the fields of aerospace technology, medical engineering, building industry, electronic manufacturing and the like. Among various types of 3D printing technologies, Stereolithography (SLA) has been made clear from many advantages such as short curing time, high printing accuracy, energy saving, and environmental protection. In addition, the printed articles have excellent properties in terms of hardness, chemical resistance and abrasion resistance.

With the rapid development of 3D printing technology, people have higher and higher requirements on the quality of photocuring 3D printed products. The photosensitive resin is used as a molding consumable of an SLA technology, and directly influences the application prospect of the technology. The photosensitive resin is mainly composed of 4 parts: the oligomer is prepared by adding active diluent, photoinitiator and other auxiliary agents on the basis of oligomer (oligomer). The photosensitive resins commonly used are urethane resins, epoxy resins and acrylate resins. These resins can be used to make complex articles such as jewelry, surgical stents, molds. However, most of these 3D printed articles cannot be directly used for equipment parts in some special fields, such as aerospace and automotive fields. Since these resins all have significant drawbacks in heat resistance, mechanical properties, etc. For example, epoxy resins have poor heat resistance and impact resistance; the acrylate resin has poor water resistance and high temperature resistance and large curing shrinkage. This greatly limits the further development of SLA technology. Therefore, the development of novel high-performance photosensitive materials for photocuring 3D printing is of great significance to both academic and industrial fields.

Bismaleimide (BMI) resin is a novel thermosetting polymer, has good dielectric properties, fatigue resistance under high humidity conditions, high glass transition temperature, excellent thermal stability and the like, is widely used as a base material of a composite material, and has wide application in the fields of aerospace, electronics and the like. The excellent performance of bismaleimide attracts the research of scholars at home and abroad, but the application of bismaleimide to 3D printing still has certain difficulty.

Liquid crystal materials are excellent in optical, electrical and mechanical properties due to their unique molecular shapes and chemical structures. The acrylate liquid crystal resin can be cured by heat under the conditions of initiator initiation or thermal initiation to obtain a cured resin. However, due to the limitations of initiation systems and temperature, the thermosetting acrylate liquid crystal resin is generally polymerized by light. When the photopolymerization is adopted, the polymerization temperature can be randomly selected within the liquid phase temperature range, and the two processes of orientation and polymerization can be completely independent, namely, the polymerization is carried out after the liquid crystal resin can be fully oriented. However, this method is suitable for preparing thin films and is not suitable for parts with larger thickness.

The three-dimensional Stereolithography (SLA) can rapidly obtain three-dimensional structural parts of any shape by laser layer-by-layer solidification of liquid crystal resin. This technique overcomes the limitation of photocuring on the thickness and shape of the article. If the excellent properties of bismaleimide and the characteristics of liquid crystal resin are retained and applied to 3D printing, the mechanical properties and thermal stability of the product are inevitably improved to some extent. Therefore, a novel bismaleimide and acrylic acid based liquid crystal photosensitive resin composition is developed, and the application of the composition in 3D printing is extremely potential.

Therefore, based on the thought, the photosensitive resin composition for 405nm photocuring 3D printing based on the bismaleimide/acrylic liquid crystal resin is developed, so that the application of the bismaleimide photosensitive resin and the acrylic liquid crystal resin is widened, and the defect of poor formability is overcome; and a novel high-performance photosensitive resin composition is obtained, which is beneficial to popularization and promotion of a 405nm photocuring 3D printing technology.

Disclosure of Invention

In view of the situations and deficiencies of the prior art, the present invention aims to provide a bismaleimide/acrylic liquid crystal based photosensitive resin composition with excellent thermal stability and mechanical properties and application thereof in 405nm3D printing.

In order to achieve the technical purpose, the invention adopts the technical scheme that:

a bismaleimide/acrylic liquid crystal photosensitive resin-based composition comprises the following raw materials in parts by weight:

preferably, the synthesis route of the bismaleimide-based resin is shown in the attached figure 1, and the synthesis steps comprise:

(1) mixing 100 parts of bismaleimide and 100-200 parts of aromatic diamine as raw materials in terms of mole, adding an organic solvent and 0-2 parts of catalyst 3, and reacting at 40-80 ℃ for 1-3 hours to obtain a solution A1;

(2) removing the organic solvent by vacuum concentration to obtain solution B1;

(3) adding 0-1 part of catalyst 4 and 0-0.5 part of polymerization inhibitor 2 into the solution B1 in terms of mole, then slowly dropwise adding 100-400 parts of glycidyl methacrylate, and reacting at 50-70 ℃ for 4-12 hours; obtaining the bismaleimide resin, wherein the structural formula of the bismaleimide resin is as follows:

R₁：

R₂：

wherein the bismaleimide is N, N '-1, 3-phenylene bismaleimide, 4' -diphenylmethane bismaleimide or a combination thereof; the aromatic diamine is 4,4 '-diaminodiphenylmethane, p-phenylenediamine, 2' -dimethyl-4, 4 '-diaminobiphenyl, 4' -diaminodiphenyl ether or their combination. The organic solvent is acetone, dichloroethane, tetrahydrofuran, chloroform, ethyl acetate or acetonitrile; the catalyst 3 in the step (1) is glacial acetic acid or zinc chloride.

The catalyst 4 in the step (3) is tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride; the polymerization inhibitor 1 is hydroquinone.

Preferably, the synthetic route of the acrylic liquid crystal photosensitive resin is shown in fig. 2, and the synthetic steps comprise:

(1) 10 parts by mole of a mesogen-containing compound having-OH at the end, 50 to 500 parts by mole of a ringMixing oxychloropropane (EHC) and 0.1-1.0 part of catalyst 1 serving as raw materials, and introducing N₂Protecting, and then reacting for 5-24 hours at 40-100 ℃ to obtain a solution A2;

(2) slowly dropping 20-50 parts of NaOH solution (with the concentration of 30% -60%) into the solution A2 in terms of moles, removing water generated by the reaction under reduced pressure by using a vacuum pump, continuously reacting for 0.1-4 hours, pouring the product into a separating funnel, filtering to remove NaCl, removing redundant EHC from the obtained filtrate by using a rotary evaporator to obtain a solution B2;

(3) mixing the solution B2 with a methanol/acetone solution (the ratio is 1.0: 0.1-1.0: 10), and placing the mixture into a refrigerator for cooling and crystallizing. Washing the obtained crystal with methanol, performing suction filtration, and drying the product in an oven at 60-100 ℃ to obtain a milky white solid, namely the liquid crystal epoxy resin C;

(4) taking 10 parts of liquid crystal epoxy resin C and 0.1-1.0 part of polymerization inhibitor by mol, adding the liquid crystal epoxy resin C and the polymerization inhibitor into a flask, setting the reaction temperature to be 90-150 ℃, slowly dripping 20-25 parts of acrylic acid after the epoxy resin C is completely melted, dripping 0.01-0.1 part of catalyst 2, reacting for 0.5-5.0 hours, and cooling to obtain light yellow viscous resin, namely the acrylic acid liquid crystal photosensitive resin; the synthesis route is as follows:

wherein the compound containing mesomorphic elements and having-OH at the end is one or the combination of 4-hydroxyphenyl 4-hydroxybenzoate, 4 '-biphenol, 3',5,5 '-tetramethyl biphenol, 4- ((4-hydroxyphenoxy) carbonyl) phenyl 4-hydroxybenzoate, 2, 3-bis (4-hydroxyphenyl) acrylonitrile, 4' -propylidenebisphenol and the like; the catalyst 1 in the step (1) is one or a combination of tetramethylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraethylammonium bromide, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetradecyltrimethylammonium chloride and the like; the polymerization inhibitor in the step (4) is one or a combination of hydroquinone, benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butyl hydroquinone and 2, 5-di-tert-butyl hydroquinone; the catalyst 2 in the step (4) is one or a combination of N, N-diethylaniline, N-dimethyl-p-toluidine, N-dimethylbenzylamine, N-dimethylcyclohexylamine, N '-dimethylpyridine, N' -diethylpiperazine and the like.

Preferably, the urethane acrylate resin is at least one selected from aliphatic urethane acrylate oligomer, aromatic urethane acrylate oligomer, urethane diacrylate and dimethyl urethane acrylate resin.

Preferably, the polymerization degree of the polyethylene glycol dimethacrylate resin is 1-200.

Preferably, the alkoxylated acrylate monomer is at least one selected from glycerol oxide triacrylate and ethoxylated pentaerythritol tetraacrylate.

Preferably, the diluent is selected from at least one of styrene, acrylate diluent, hydroxyl acrylate diluent, vinyl ether diluent and cyclohexane diluent; the acrylate diluent is at least one selected from methyl methacrylate, 1, 6-hexanediol diacrylate, isobornyl acrylate, tetrahydrofuran acrylate, tripropylene glycol diacrylate, hexanediol diacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, isobornyl acrylate and cyclic trimethylolpropane formal acrylate; the acrylate diluent is at least one selected from hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxyethyl acrylate; the vinyl ether diluent is selected from at least one of 4-hydroxybutyl vinyl ether and diethylene glycol divinyl ether; the cyclohexane diluent is selected from at least one of 4-vinyl cyclohexene oxide and 4-vinyl cyclohexene oxide.

Preferably, the photoinitiator is diphenyl- (4-phenylsulfide) phenylsulfinium hexafluoroantimonate, diphenyl- (4-phenylsulfide) phenylsulfinium hexafluorophosphate, 4-octyloxybenzoniumiodohexafluoroantimonate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, diphenyliodonium hexafluorophosphate, 4-isopropyl-4' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium tetrafluoroborate, tri-p-tolylsulfonium hexafluorophosphate, 1-hydroxy-cyclohexyl-acetophenone, α -dimethyl- α -hydroxyacetophenone, p-isopropylphenyl-2-hydroxydimethylacetone-1, benzophenone chloride, acrylated benzophenone, 4-phenylbenzophenone, sodium chloride, potassium chloride, sodium chloride, and sodium chloride, and sodium chloride, and sodium chloride, and sodium chloride, 2-thioxanthone chloride, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, dimethylthioxanthone, diethylthioxanthone, dichlorothioxanthone, 2-phenylbenzyl-2-dimethylamine-1- (4-morpholinebenzylphenyl) butanone.

Preferably, the defoaming agent is selected from at least one of silicone defoaming agents, mineral oil defoaming agents, polyether defoaming agents and fatty alcohol defoaming agents.

Preferably, the leveling agent is selected from at least one of an acrylic leveling agent, an organic silicon leveling agent, and a fluorocarbon leveling agent.

Preferably, the antioxidant is at least one selected from pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxy) phenylpropionate, tris (2, 4-di-tert-butyl) phenyl phosphite, N' -bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexanediamine and 2, 6-di-tert-butyl-4-methylphenol.

Preferably, the bismaleimide/acrylic liquid crystal photosensitive resin-based composition is applied to 405nm photocuring 3D printing to obtain a molded part. Carrying out ultraviolet light post-treatment on the obtained formed part, wherein the light intensity of the ultraviolet light is 100W/cm²The ultraviolet curing time is 0-10 minutes, and the ultraviolet curing is carried out for 0-120 minutes after the ultraviolet curing is carried out at 100-250 ℃ under the vacuum condition.

By adopting the technical scheme, compared with the prior art, the invention has the beneficial effects that: the bismaleimide-based photosensitive resin and the acrylic liquid crystal photosensitive resin are simultaneously introduced into the photosensitive resin composition, so that the characteristics of the bismaleimide-based photosensitive resin and the acrylic liquid crystal photosensitive resin can be reserved, and printed products have excellent mechanical properties and thermal stability, so that the bismaleimide-based photosensitive resin and the acrylic liquid crystal photosensitive resin can be widely applied to the fields of electronic devices, aerospace and the like. Meanwhile, the bismaleimide/acrylic acid liquid crystal photosensitive resin composition for 3D printing provided by the invention has the advantages of good printability, capability of printing a complex structure, low preparation cost, effective reduction of the price of 405nm3D printing resin, and laying a foundation for large-scale application of 405nm3D printing technology.

Drawings

FIG. 1 shows a synthetic route of a bismaleimide-based resin according to the present invention.

FIG. 2 is a synthetic route of an acrylic liquid crystal photosensitive resin according to the present invention.

FIG. 3 is a model printed by a 405nm3D printer of the bismaleimide/acrylic liquid crystal photosensitive resin composition prepared in example 1 of the present invention and a comparative example.

FIG. 4 is a thermogravimetric curve of a bar printed on a 405nm3D printer of the bismaleimide/acrylic liquid crystal photosensitive resin composition prepared in example 1 of the present invention and a comparative example.

FIG. 5 is a dynamic mechanical property test curve of bars printed on a 405nm3D printer by using the bismaleimide/acrylic liquid crystal photosensitive resin composition prepared in example 1 of the present invention and a comparative example.

Detailed Description

The invention is further illustrated with reference to the following specific embodiments:

bismaleimide resin:

n, N' -1, 3-phenylenebismaleimide resin, abbreviated as A-1;

4,4' -diphenylmethane bismaleimide resin, abbreviated as A-2;

acrylic liquid crystal photosensitive resin:

4-hydroxyphenyl-4-hydroxybenzoate-based acrylic liquid crystal photosensitive resin, abbreviated as B-1;

4,4' -biphenyldiphenol acrylic acid liquid crystal photosensitive resin, abbreviated as B-2;

urethane acrylate resin:

aliphatic urethane acrylate 1: purchased from sandoma corporation, product number CN9010, abbreviated as C-1;

aliphatic urethane acrylate 2: purchased from sandoma corporation under product number CN991, abbreviated as C-2;

polyethylene glycol dimethacrylate resin:

polyethylene glycol dimethacrylate resin 1: purchased from sandoma corporation, product number SR210, abbreviated D-1;

polyethylene glycol dimethacrylate resin 2: purchased from sandoma corporation under product number SR211, abbreviated D-2;

alkoxylated acrylates:

ethoxylated pentaerythritol tetraacrylate, available from Saedoma, product number SR494, abbreviated as E-1;

glycerol propylene oxide triacrylate, available from sartomer company under product number SR9020, abbreviated as E-2;

diluent agent:

cyclotrimethylolpropane formal acrylate: purchased from sandoma corporation under product number SR351, abbreviated as F-1;

hydroxypropyl methacrylate: purchased from Aladdin reagent (Shanghai) Inc., abbreviated as F-2;

hydroxyethyl methacrylate: purchased from Aladdin reagent (Shanghai) Inc., abbreviated as F-3;

photoinitiator (2):

2, 4, 6- (trimethylbenzoyl) diphenylphosphine oxide, available from the group of the Aladdin reagents (Shanghai) Ltd, product number photoinitiator TPO, abbreviated as G-1;

phenylbis (2, 4, 6-trimethylbenzoyl) phosphine oxide: purchased from Aladdin reagent (Shanghai) Inc., product number photoinitiator XBPO, abbreviated as G-2;

1-hydroxy-cyclohexyl-acetophenone: available from Allantin reagents (Shanghai) Inc., product number photoinitiator 184, abbreviated as G-3;

defoaming agent:

silicone defoaming agent: purchased from Bike chemical company, Germany, under the product number BYK-088, abbreviated as H-1;

polyether defoaming agent: purchased from Guangdong Union of China, Fine chemical Co., Ltd, product number B-299, abbreviated as H-2;

leveling agent:

an organic silicon leveling agent: purchased from Anhui Jia Xinnuo chemical products, Inc., product number WE-D5510, abbreviated as I-1;

polyacrylic acid leveling agent: purchased from Anhui Jia Xinnuo chemical products, Inc., product number WE-D819, abbreviated as I-2;

antioxidant:

2, 6-di-tert-butyl-4-methylphenol: available from Allantin reagent (Shanghai) Inc., product number antioxidant BHT, abbreviated as J-1;

pentaerythritol tetrakis (3, 5-di-tert-butyl-4-hydroxy) phenylpropionate: purchased from Kyon chemical Co., Ltd, Guangzhou, antioxidant 1010, abbreviated as J-2.

Examples 1-8 (i.e., preparation of sample # 1 to sample # 8)

Examples preparation of sample # 1 to sample # 8

The preparation steps are as follows: mixing a proper amount of bismaleimide resin, acrylic liquid crystal photosensitive resin, polyurethane acrylate resin, polyethylene glycol dimethacrylate resin, alkoxylated acrylate, a diluent, a defoaming agent, a leveling agent and an antioxidant, heating to 30-100 ℃, uniformly stirring and mixing, cooling, adding a photoinitiator, and uniformly stirring to obtain yellow viscous liquid, thereby obtaining the bismaleimide/acrylic liquid crystal photosensitive resin-based composition sample.

The relationship between the sample number and the types and ratios of the components is shown in Table 1.

TABLE 1

The formulated bismaleimide/acrylic liquid crystal photosensitive resin-based composition was poured into a Form 23D printer manufactured by Formlabs, inc, U.S. and molded by computer modeling, patterning, and post-printing. Carrying out ultraviolet curing and thermocuring treatment on the obtained product; wherein the light intensity of the ultraviolet light is 100W/cm²The ultraviolet curing time is 2min, and the ultraviolet curing is carried out for 60 min under the vacuum condition at 150 ℃.

As shown in Table 2, the photosensitive resin compositions were evaluated by observing the appearance of the cured products of the products obtained in the above examples, and it was found that the examples all had excellent mechanical properties.

TABLE 2

Referring to FIG. 3, it is a printed model of the bismaleimide/acrylic liquid crystal photosensitive resin-based composition prepared in example 1 according to the present invention on a 405nm3D printer.

Referring to FIG. 4, there are shown Thermogravimetric (TGA) curves of specimens printed under nitrogen atmosphere at 405nm on a 3D printer based on a bismaleimide/acrylic liquid crystal photosensitive resin composition prepared in example 1 of the present invention and comparative example, and the temperature rise rate is 10 ℃/min. The initial thermal decomposition temperature is 331.7.1 ℃, the maximum decomposition temperature is 439.1 ℃, and the carbon residue rate at 800 ℃ is 5.8%. Superior to the comparative example, it was found to have excellent thermal stability.

Referring to FIG. 5, it is shown that the bismaleimide/acrylic liquid crystal photosensitive resin-based composition prepared in example 1 of the present invention and a comparative example print a dynamic mechanical property test curve of a sample bar on a 405nm3D printer. It can be seen that the composition prepared in example 1 has a storage modulus of 2623MPa and a glass transition temperature of 117.4 c, which are superior to those of the comparative example, and thus has excellent mechanical properties and thermal stability.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.