Low-temperature ultraviolet light-heat sequential curing conductive ink

Abstract

The invention discloses low-temperature ultraviolet light-heat sequentially cured conductive ink. The conductive ink comprises the following raw materials in percentage by mass: 10-20% of a conductive phase, 50-70% of a binding phase, 10-20% of an active monomer, 3-5% of a photoinitiator, 3-5% of a thermal curing agent and 0-4% of an additive, the binding phase is acrylate resin and epoxy resin, and the molar ratio of the acrylate resin to the epoxy resin is (1: 4)-(4: 1). The cleaning agent does not contain a volatile solvent and is environment-friendly; the curing speed and the production efficiency are high; and the curing temperature is low.

Description

Technical Field

[0001] The invention relates to the field of conductive ink, and in particular to a conductive ink cured by low-temperature ultraviolet light-heat sequence. Background Art

[0002] UV curing technology is characterized by high efficiency, environmental protection and low energy consumption. However, since most conductive fillers are colored and have a shielding effect on ultraviolet light, there is a problem of incomplete curing in the application of photocurable slurry in the preparation of thick film circuits. Thick film circuits are currently prepared by thermal curing. Long-term high-temperature heating can easily cause deformation of some base materials that are not resistant to high temperatures, and also cause energy waste. At present, there is still a lack of a method that can quickly cure conductive patterns at low temperatures.

[0003] For example, patents CN201210574795.8, CN1778845A, CN201610545355.8, and CN200410011261.X contain volatile organic compounds, which can easily cause environmental pollution during the heating and curing process, and some solvents can cause harm to the human body. Summary of the invention

[0004] The object of the present invention is to provide a low-temperature ultraviolet light-heat sequentially cured conductive ink.

[0005] The innovation of the present invention is that the overall formula design does not contain solvents, and the conductive ink is diluted with active monomers. The active monomers participate in the curing reaction and can form stable chemical bonds with the resin matrix. There is no solvent volatilization in the conductive ink and the preparation process, which is environmentally friendly.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is:

[0007] A low-temperature ultraviolet light-heat sequentially cured conductive ink comprises the following raw materials in percentage by mass: 10-20% of a conductive phase, 50-70% of a bonding phase, 10-20% of an active monomer, 3-5% of a photoinitiator, 3-5% of a thermal curing agent and 0-4% of an additive; the bonding phase is an acrylate resin and an epoxy resin, and the molar ratio of the acrylate resin to the epoxy resin is 1:4 to 4:1.

[0008] Furthermore, the acrylic resin is one of bisphenol A epoxy acrylate resin, bisphenol F epoxy acrylate resin, and polyurethane acrylate resin; the epoxy resin is one of bisphenol A epoxy resin or bisphenol F epoxy resin.

[0009] Furthermore, the conductive phase is a mixture of one or more of micron-sized silver powder, copper powder, carbon black, graphene, and carbon nanotubes.

[0010] Furthermore, the active monomer is a small molecule active monomer containing an acrylic group and / or an epoxy group.

[0011] Furthermore, the active monomer is acrylate with a carbon chain length less than 8, tripropylene glycol diacrylate, hexanediol diacrylate, ethylene glycol diglycidyl ether with a diepoxy group, resorcinol diglycidyl ether or glycidyl methacrylate.

[0012] Furthermore, the photoinitiator includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, and methyl benzoylformate.

[0013] Furthermore, the thermal curing agent includes one of aliphatic amine curing agents, imidazole curing agents, and dicyandiamide curing agents.

[0014] Furthermore, the additive includes one of terpineol, polydimethylsiloxane, and polyether-modified silicone oil.

[0015] A method for preparing a low-temperature ultraviolet light-heat sequentially cured conductive ink comprises the following steps:

[0016] (1) preparing a bonding phase: taking materials according to a formula, mixing an acrylic resin and an epoxy resin evenly to obtain a mixed resin, and adding an active monomer to the mixed resin to obtain a bonding phase;

[0017] (2) preparing a non-conductive phase: adding a photoinitiator and a thermal curing agent to the adhesive phase and mixing them to obtain a non-conductive phase;

[0018] (3) Preparation of conductive ink: Add the conductive phase into the non-conductive phase, and roll until the fineness is less than or equal to a set value to obtain a finished product.

[0019] Furthermore, in the step (3), the conductive phase is added to the non-conductive phase and then the additive is added, and the mixture is rolled with a three-roll mill until the fineness is less than or equal to a set value to obtain a finished product.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention does not contain volatile solvents, and uses active monomers to dilute the conductive ink. Therefore, no solvent evaporates during the preparation and subsequent use, and no environmental harm is generated.

[0022] 2. The present invention uses both acrylic resin and epoxy resin, which can be quickly formed under ultraviolet light and then completely cured by heating in an oven. This process avoids the shape change of the conductive pattern before curing, thereby reducing the fineness of the lines.

[0023] 3. The conductive ink prepared by the present invention has a fast curing speed and high production efficiency. It also has a low curing temperature and is suitable for flexible substrates that are not resistant to high temperatures. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below.

[0025] Example 1: A low-temperature UV-heat sequentially cured conductive ink, comprising the following raw materials in percentage by mass: 10% conductive phase, 70% bonding phase, 12% active monomer, 4% photoinitiator, 3% thermal curing agent and 1% additive; the bonding phase is acrylic resin and epoxy resin, and the molar ratio of acrylic resin to epoxy resin is 1:4.

[0026] The acrylic resin is bisphenol A type epoxy acrylate resin; the epoxy resin is bisphenol A type epoxy resin.

[0027] The conductive phase is micron-sized silver powder.

[0028] The active monomer is a small molecule active monomer containing an propylene group; the active monomer is an acrylate with a carbon chain length of less than 8.

[0029] Photoinitiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0030] Thermal curing agents include aliphatic amine curing agents.

[0031] Additives include terpineol.

[0032] Example 2: A low-temperature UV-heat sequentially cured conductive ink, comprising the following raw materials in percentage by mass: 20% conductive phase, 58% bonding phase, 10% active monomer, 3% photoinitiator, 5% thermal curing agent and 4% additives; the bonding phase is acrylic resin and epoxy resin, and the molar ratio of acrylic resin to epoxy resin is 2:2.

[0033] The acrylic resin is bisphenol F type epoxy acrylate resin; the epoxy resin is bisphenol F type epoxy resin.

[0034] The conductive phase is micron-sized copper powder.

[0035] The active monomer is a small molecule active monomer containing an epoxy group.

[0036] The active monomer is ethylene glycol diglycidyl ether with a diepoxy group having a carbon chain length of less than 8.

[0037] Photoinitiators include 2-hydroxy-2-methyl-1-phenylpropanone.

[0038] Thermal curing agents include imidazole curing agents.

[0039] Additives include polydimethylsiloxane.

[0040] Example 3: A low-temperature UV-heat sequentially cured conductive ink, comprising the following raw materials in percentage by mass: 17% conductive phase, 50% bonding phase, 20% active monomer, 5% photoinitiator, 5% thermal curing agent and 3% additives; the bonding phase is acrylic resin and epoxy resin, and the molar ratio of acrylic resin to epoxy resin is 2 to 3.

[0041] The acrylic resin is polyurethane acrylate resin; the epoxy resin is bisphenol A epoxy resin.

[0042] The conductive phase is micron-sized carbon black.

[0043] The active monomer contains an acrylic group and is tripropylene glycol diacrylate.

[0044] Photoinitiators include methyl benzoylformate.

[0045] Thermal curing agents include dicyandiamide.

[0046] The additive is included in polyether modified silicone oil.

[0047] Example 4: A low-temperature UV-heat sequentially cured conductive ink, comprising the following raw materials in percentage by mass: 15% conductive phase, 60% bonding phase, 18% active monomer, 3% photoinitiator, 4% thermal curing agent; the bonding phase is acrylic resin and epoxy resin, and the molar ratio of acrylic resin to epoxy resin is 4:1.

[0048] The acrylic resin is a bisphenol A type epoxy acrylate resin; the epoxy resin is a type of bisphenol F type epoxy resin.

[0049] The conductive phase is micrometer-sized graphene.

[0050] The active monomer contains an propylene group.

[0051] The active monomer is hexanediol diacrylate with a carbon chain length of less than 8.

[0052] Photoinitiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0053] Thermal curing agents include aliphatic amine curing agents.

[0054] Example 5: Referring to Example 1, the acrylic resin is one of bisphenol A epoxy acrylate resin, bisphenol F epoxy acrylate resin, and polyurethane acrylate resin; the epoxy resin is one of bisphenol A epoxy resin or bisphenol F epoxy resin.

[0055] The conductive phase is a mixture of one or more of micron-sized silver powder, copper powder, carbon black, graphene, and carbon nanotubes.

[0056] The active monomer is a small molecule active monomer containing an acrylic group and / or an epoxy group.

[0057] The active monomer is acrylate with a carbon chain length less than 8, tripropylene glycol diacrylate, hexanediol diacrylate, ethylene glycol diglycidyl ether with a diepoxy group, resorcinol diglycidyl ether or methacrylate glycidyl ether.

[0058] The photoinitiator includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, and methyl benzoylformate.

[0059] The thermal curing agent includes one of aliphatic amine curing agent, imidazole curing agent and dicyandiamide curing agent.

[0060] The additive includes one of terpineol, polydimethylsiloxane and polyether modified silicone oil.

[0061] Embodiment 6: A method for preparing a low-temperature UV-heat sequentially cured conductive ink, comprising the following steps:

[0062] Preparation of a bonding phase: taking materials according to the formula of Examples 1 to 3, mixing acrylic resin and epoxy resin evenly to obtain a mixed resin, and adding active monomers to the mixed resin to obtain a bonding phase;

[0063] Prepare the non-conductive phase: add the photoinitiator and the thermal curing agent into the adhesive phase and mix well to obtain the non-conductive phase;

[0064] Preparation of conductive ink: Add the conductive phase into the non-conductive phase, roll until the fineness is less than or equal to the set value, and obtain the finished product.

[0065] Example 7: Referring to Example 5, take materials according to the formula of Example 4, add the conductive phase into the non-conductive phase and then add the additives, and roll with a three-roll mill until the fineness is less than or equal to the set value to obtain a finished product.

[0066] The conductive inks cured by low-temperature UV-heat sequential curing of Examples 6 and 7 were screen printed, leveled, irradiated at a light intensity of 90 W for 5 seconds, cooled and kept still at room temperature, and then placed in an oven at 80° C. for 2 hours or in an oven at 100° C. for 0.5 hours to obtain a conductive pattern.

[0067] The described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A low-temperature UV-heat sequentially cured conductive ink, characterized in that: The invention comprises the following raw materials in percentage by mass: 10-20% of a conductive phase, 50-70% of a bonding phase, 10-20% of an active monomer, 3-5% of a photoinitiator, 3-5% of a thermal curing agent and 0-4% of an additive; the bonding phase is an acrylic resin and an epoxy resin, and the molar ratio of the acrylic resin to the epoxy resin is 1:4-4:

1.

2. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The acrylic resin is one of bisphenol A epoxy acrylate resin, bisphenol F epoxy acrylate resin, and polyurethane acrylate resin; the epoxy resin is one of bisphenol A epoxy resin or bisphenol F epoxy resin.

3. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The conductive phase is a mixture of one or more of micron-sized silver powder, copper powder, carbon black, graphene, and carbon nanotubes.

4. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The active monomer is a small molecule active monomer containing an propylene group and / or an epoxy group.

5. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The active monomer is acrylate with a carbon chain length less than 8, tripropylene glycol diacrylate, hexanediol diacrylate, ethylene glycol diglycidyl ether with a diepoxy group, resorcinol diglycidyl ether or glycidyl methacrylate.

6. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The photoinitiator includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, and methyl benzoylformate.

7. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The thermal curing agent includes one of aliphatic amine curing agent, imidazole curing agent and dicyandiamide curing agent.

8. The low-temperature UV-heat sequentially cured conductive ink according to claim 1, characterized in that: The additive includes one of terpineol, polydimethylsiloxane and polyether modified silicone oil.

9. A method for preparing a low-temperature UV-heat sequentially cured conductive ink as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: (1) preparing a bonding phase: taking materials according to a formula, mixing an acrylic resin and an epoxy resin evenly to obtain a mixed resin, and adding an active monomer to the mixed resin to obtain a bonding phase; (2) preparing a non-conductive phase: adding a photoinitiator and a thermal curing agent to the adhesive phase and mixing them to obtain a non-conductive phase; (3) Preparation of conductive ink: Add the conductive phase into the non-conductive phase, and roll until the fineness is less than or equal to a set value to obtain a finished product.

10. The method for preparing the low-temperature ultraviolet light-heat sequentially cured conductive ink according to claim 9, characterized in that: In the step (3), the conductive phase is added to the non-conductive phase and then the additive is added, and the mixture is rolled with a three-roller mill until the fineness is less than or equal to a set value to obtain a finished product.