UV-LED inkjet material, preparation method and application thereof

Abstract

The application discloses a kind of UV-LED inkjet materials and its preparation method and application.The above-mentioned inkjet material includes the following components: photoinitiator;UV monomer;Carboxyl functional modified epoxy acrylate;Amine modified polyether acrylate;Filler;The above-mentioned carboxyl functional modified epoxy acrylate includes at least one of carboxyl functional modified bisphenol A type epoxy resin and carboxyl functional modified heterocyclic epoxy resin.The present application has good flowability, and the viscosity at 25 DEG C is controlled in 30-40 cps, the particle size D95 is controlled to be less than or equal to 700 nm, and the technical requirements of inkjet printing are met.The film layer formed after curing plays a temporary protective role for the circuit board copper-clad plate, and can meet the performance requirements of resisting etching liquid etching without falling off and fading in dilute lye.

Description

Technical Field

[0001] This invention relates to the field of inkjet printing technology, and in particular to a UV-LED inkjet material, its preparation method, and its application. Background Technology

[0002] A PCB (Printed Circuit Board) is a basic component used to support and connect electronic components. It is typically made of insulating material covered with conductive material (usually copper foil), and uses printed lines, holes, and other specific structures to achieve the connection and circuit functions between electronic components.

[0003] In traditional PCB manufacturing processes, resists such as liquid photosensitive inks or dry films have always been the primary materials used to create the etch-resistant layer. During PCB fabrication, these materials are used to etch the exposed copper surface through exposure and development steps to form the circuitry. However, this traditional process has several drawbacks, including high energy consumption, long production cycles, and high labor costs. Furthermore, the subtractive process in development also leads to waste of resist and developer.

[0004] Against this technological backdrop, developing novel inkjet materials has emerged as a potential solution to improve PCB (Printed Circuit Board) manufacturing processes and enhance efficiency and quality. Inkjet materials possess high stability and resistance to acid etching, enabling direct printing onto the PCB surface using inkjet technology to form desired circuit patterns and structures. However, current processes have not yet met the requirements for high stability and resistance to acid etching in inkjet materials. Summary of the Invention

[0005] The first technical problem to be solved by this invention is:

[0006] An inkjet material is provided.

[0007] The second technical problem to be solved by this invention is:

[0008] A method for preparing the inkjet material is provided.

[0009] The third technical problem to be solved by this invention is:

[0010] The application of the inkjet material.

[0011] The present invention also proposes a circuit board comprising the aforementioned inkjet material printed on its surface using inkjet technology.

[0012] To solve the first technical problem, the technical solution adopted by the present invention is as follows:

[0013] An inkjet material comprising the following components:

[0014] Photoinitiator;

[0015] UV monomers;

[0016] Carboxyl-functionalized modified epoxy acrylate;

[0017] Amine-modified polyether acrylate;

[0018] filler;

[0019] The carboxyl-functionalized modified epoxy acrylate includes at least one of carboxyl-functionalized bisphenol A type epoxy resin and carboxyl-functionalized heterocyclic epoxy resin.

[0020] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0021] The anti-corrosion inkjet material of this invention has good flowability, with a viscosity controlled at 30-40 cps at 25°C and a particle size D95≤700nm, meeting the technical requirements of inkjet printing. The film layer formed after curing provides temporary protection for the copper-clad laminate of the circuit board, meeting the performance requirements of being resistant to etching solution without peeling off and being able to be removed in dilute alkaline solution.

[0022] The main performance aspects of inkjet materials are determined by the properties of oligomers. In order to meet the performance requirements of inkjet materials that can be delaminated in dilute alkaline solutions, that is, to ensure that inkjet materials meet the characteristics of being acid-resistant but not alkali-resistant, this invention introduces oligomers with carboxyl groups into the components, namely carboxyl-functionalized epoxy acrylate.

[0023] The resins used in this invention preferably contain polar atomic groups or special groups, such as carboxyl-functionalized epoxy acrylates and / or amine-modified polyether acrylates containing carboxyl groups, amine groups, and urea rings (with a nitrogen content as high as 14%), which are beneficial for improving adhesion to metal surfaces. Through physical adsorption and chemical bonding with metal surfaces via polar groups and rigid planes, the inkjet printing adhesion performance on copper surfaces is improved.

[0024] According to one embodiment of the present invention, the inkjet material comprises the following components in parts by weight:

[0025] Photoinitiator, 4-8 parts;

[0026] UV monomer, 40-60 parts;

[0027] Carboxyl-functionalized epoxy acrylate and amine-modified polyether acrylate, 10-40 parts;

[0028] Filler, 5-20 parts.

[0029] According to one embodiment of the present invention, the raw material for preparing carboxyl-functionalized modified epoxy acrylate includes epoxy resin, wherein the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyphenolic glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, and heterocyclic epoxy resin.

[0030] Among them, bisphenol A type epoxy resin has epoxy groups and hydroxyl groups that give the resin reactivity, while its benzene ring gives the polymer heat resistance and rigidity, making it the most commonly used epoxy resin.

[0031] According to one embodiment of the present invention, the bisphenol A type epoxy resin includes bisphenol A diglycidyl ether, which has an epoxy equivalent of 170 g / eq and contains two epoxy groups. In the process of preparing carboxyl-functionalized modified epoxy acrylate, the epoxy groups can form two side hydroxyl groups after ring-opening esterification with acrylic acid.

[0032] Among them, bisphenol F type epoxy resin is characterized by the absence of isopropyl groups. The absence of isopropyl groups causes steric hindrance, which reduces its viscosity. However, it also makes it easier to crystallize, and reduces its heat resistance and stability.

[0033] Among them, polyphenolic glycidyl ether epoxy resin molecules have two or more epoxy groups, generally have higher viscosity, and high crosslinking density of cured products, making them suitable for screen printing processes, but not for inkjet printing which requires lower viscosity.

[0034] Aliphatic glycidyl ether epoxy resin is formed by two or more epoxy groups directly linked to an aliphatic chain. The molecular chain does not contain cyclic structures such as benzene rings, aliphatic rings, or heterocyclic rings. Most of these resins have very low viscosity and are hydrophilic. Most are long-chain molecules, which are flexible, but have poor heat resistance.

[0035] Among them, heterocyclic epoxy resins are a class of high-performance epoxy resins in which glycidyl groups are directly linked to heterocyclic groups, and they have excellent heat resistance, weather resistance and electrical properties.

[0036] Therefore, in the inkjet material of the present invention, the carboxyl-functionalized modified epoxy acrylate includes at least one of carboxyl-functionalized modified bisphenol A type epoxy resin and carboxyl-functionalized modified heterocyclic epoxy resin.

[0037] According to one embodiment of the present invention, the raw materials for preparing the carboxyl-functionalized heterocyclic epoxy resin include heterocyclic epoxy resin.

[0038] According to one embodiment of the present invention, the heterocyclic epoxy resin includes at least one of triaza-heterocyclic epoxy resin and hydantoin epoxy resin.

[0039] According to one embodiment of the present invention, the triazine heterocyclic epoxy resin includes triglycidyl isocyanurate (TGIC), which is an epoxy resin containing a triazine heterocycle and three epoxy groups. The epoxy group reactivity of TGIC is higher than that of bisphenol A type epoxy resin. Triazine heterocycles are very stable and possess excellent heat resistance, weather resistance, light resistance, corrosion resistance, and chemical resistance.

[0040] According to one embodiment of the present invention, the hydantoin epoxy resin is a novel type of epoxy resin containing a five-membered dinitrogen heterocycle (hydantoin ring). It possesses characteristics such as low viscosity, good thermal stability, high heat resistance, good weather resistance, and good chemical resistance. However, its disadvantage is its flammability. Hydantoin epoxy resin, by reacting with acrylic acid to introduce double bonds, produces a photocurable resin that is water-soluble, and therefore is unsuitable for use in the inkjet material of the present invention.

[0041] According to one embodiment of the present invention, the structural formula of the carboxyl-functionalized bisphenol A type epoxy resin is as follows:

[0042] According to one embodiment of the present invention, the structural formula of the carboxyl-functionalized heterocyclic epoxy resin is as follows:

[0043] According to one embodiment of the present invention, the inkjet material further comprises amine-modified polyether acrylate.

[0044] According to one embodiment of the present invention, the amine-modified polyether acrylate includes at least one of Rahn's Genomer*3364, Genomer*3485, and Genomer*3497.

[0045] According to one embodiment of the present invention, the amine-modified polyether acrylate accounts for 0-15% by weight of the inkjet material component.

[0046] According to one embodiment of the present invention, the photoinitiator includes at least one of a pyrolysis-type free radical photoinitiator, a hydrogen abstraction-type free radical photoinitiator, and a visible light initiator.

[0047] According to one embodiment of the present invention, the photoinitiator has an absorption wavelength of 365–405 nm.

[0048] According to one embodiment of the present invention, the cleavage-type free radical photoinitiator includes at least one of TMO (2,4,6-trimethylbenzoyl-bis(p-tolyl)phosphine oxide), TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 819 (phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide), and 907 [(2-methyl-1-(4-methylthiophenyl)-2-morpholino-1-propanone].

[0049] According to one embodiment of the present invention, the hydrogen-abstracting free radical photoinitiator includes at least one of ITX (2-isopropylthioxanthonone) and DETX (2,4-diethylthioxanthonone).

[0050] According to one embodiment of the present invention, the visible light photoinitiator includes at least one of 784 [(2,6-difluoro-3-(1H-pyrrolidin-1)phenyl)captantinosinium] and CQ (camphorquinone).

[0051] According to one embodiment of the present invention, the UV monomer includes at least one of a monofunctional monomer, a difunctional monomer, and a trifunctional monomer.

[0052] According to one embodiment of the present invention, the monofunctional monomer includes at least one of a heteroatom-containing active monomer, an acrylate monomer with an aromatic ring, and an acrylate monomer with a hydroxyl group.

[0053] According to one embodiment of the present invention, a UV monomer containing heteroatoms, such as nitrogen atom N, oxygen atom O, etc., is selected, and polar atoms or groups are beneficial to the adhesion performance.

[0054] According to one embodiment of the present invention, UV monomers with aromatic rings, such as those with benzene rings or furan rings, are selected because the planar rigidity of the rings and the larger contact area between molecules are beneficial to the adhesion performance.

[0055] According to one embodiment of the present invention, the UV monomer includes at least one selected from N-acryloylmorpholine, N,N-dimethylacrylamide, N,N-diethylacrylamide, tetrahydrofuran methyl acrylate, phenoxyethyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, caprolactone acrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, and propoxylated glycerol triacrylate.

[0056] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0057] The UV monomers of this invention preferably contain polar atomic groups or special groups, such as UV monomers containing nitrogen atoms (e.g., ACMO), benzene rings (e.g., PHEA), or furan rings (e.g., THFA), which are beneficial for improving adhesion to metal surfaces. Through the physical adsorption and chemical bonding of polar groups, rigid planes, and other factors with metal surfaces, the inkjet's adhesion performance on copper surfaces is improved.

[0058] Among them, ACMO (N-acryloylmorpholine), DMAA (N,N-dimethylacrylamide), and DEAA (N,N-diethyldiacrylamide) are heteroatom-containing active monomers.

[0059] Among them, THFA (tetrahydrofuran methyl acrylate) and PHEA (phenoxyethyl acrylate) are acrylate monomers with aromatic rings.

[0060] Among them, 4-HBA (4-hydroxybutyl acrylate), HEMA (2-hydroxyethyl methacrylate), and CA (caprolactone acrylate) are acrylic monomers with hydroxyl groups.

[0061] Among them, HDDA (1,6-hexanediol diacrylate), TPGDA (tripropylene glycol diacrylate), DPGDA (dipropylene glycol diacrylate), NPGDA (neopentyl glycol diacrylate), and TTEGDA (tetraethylene glycol diacrylate) are bifunctional monomers.

[0062] Among them, TMPTA (trimethylolpropane triacrylate), 3EO-TMPTA (ethoxylated trimethylolpropane triacrylate), PETA (pentaerythritol triacrylate), and GPTA (propoxylated glycerol triacrylate) are trifunctional monomers.

[0063] According to one embodiment of the present invention, the inkjet material further includes color paste.

[0064] According to one embodiment of the present invention, the pigment accounts for 3.27%-3.73% by weight in the inkjet material.

[0065] According to one embodiment of the present invention, the color paste comprises nano blue paste.

[0066] According to one embodiment of the present invention, the nano blue paste comprises, by weight, the following components:

[0067] Acrylic monomer, 50-75 parts;

[0068] Phthalocyanine blue, 15-30 parts;

[0069] Dispersant, 5-15 parts.

[0070] According to one embodiment of the present invention, the acrylate monomer in the nano blue paste component includes at least one of HDDA (1,6-hexanediol diacrylate), DPGDA (dipropylene glycol diacrylate), TPGDA (tripropylene glycol diacrylate), NPGDA (neopentyl glycol diacrylate), and PET3A (pentaerythritol triacrylate).

[0071] According to one embodiment of the present invention, the phthalocyanine blue in the nano-blue paste component includes at least one of Mallak's M3K8, M3D4-XR, M4D7-X, and M4D5-XR.

[0072] According to one embodiment of the present invention, the dispersant in the nano blue paste component includes at least one of BASF efka 4030, BASF efka 4310, BASF efka 4330, BASF efka PX4701, BASF efka PX7701, and BYKJET-9150, BYKJET-9151, and BYKJET-9152.

[0073] According to one embodiment of the present invention, the filler comprises nano-barium sulfate. Because nano-barium sulfate is nano-sized and has a small particle size, it is prone to agglomeration and sedimentation, therefore its dosage should not be excessive.

[0074] According to one embodiment of the present invention, the nano-barium sulfate is selected from pure synthetic barium sulfate.

[0075] According to one embodiment of the present invention, the additive includes at least one of a leveling agent, a polymerization inhibitor, and an adhesion promoter.

[0076] According to one embodiment of the present invention, the leveling agent includes at least one of polyether siloxanes and modified polyether siloxanes.

[0077] According to one embodiment of the present invention, the leveling agent includes at least one of BYK 307, BYK 354, BYK 377, BYK 379 from BYK, and TEGO 410, TEGO 425, TEGO 432, TEGO 435, and TEGO 450 from TEGO.

[0078] According to one embodiment of the present invention, the leveling agent accounts for 0.05 to 0.5% by weight in the inkjet material.

[0079] According to one embodiment of the present invention, the polymerization inhibitor includes at least one of Rahn's Genomer*16, Genomer*18, and Genomer*20.

[0080] According to one embodiment of the present invention, the polymerization inhibitor accounts for 0.1 to 0.5% by weight in the inkjet material.

[0081] According to one embodiment of the present invention, the adhesion promoter includes at least one of Rahn's Genomer*40, Genomer*41, Genomer*20, Meiyuan's SC1400, Sartoma SR9051 NS, Meiyuan's SC1400, and Changxing's EM39.

[0082] According to one embodiment of the present invention, the adhesion promoter accounts for 0.1% to 1% by weight of the inkjet material.

[0083] To solve the second technical problem, the technical solution adopted by the present invention is as follows:

[0084] A method for preparing the inkjet material includes the following steps:

[0085] Under light-protected conditions, a photoinitiator, a UV monomer, a carboxyl-functionalized epoxy acrylate, an amine-modified polyether acrylate, and a filler are mixed to obtain the inkjet material.

[0086] According to one embodiment of the present invention, the carboxyl-functionalized modified epoxy acrylate is obtained by reacting epoxy resin, acrylic acid, saturated carboxylic anhydride or saturated dicarboxylic acid.

[0087] According to one embodiment of the present invention, saturated carboxylic acid anhydrides are used to synthesize carboxyl-functionalized modified epoxy acrylates. This is because, compared to using saturated dicarboxylic acids, the advantage of synthesizing carboxyl-functionalized oligomers with saturated carboxylic acid anhydrides is that the reaction does not produce water, eliminating the need for dehydration.

[0088] According to one embodiment of the present invention, the saturated carboxylic acid anhydride includes at least one of phthalic anhydride, succinic anhydride, and adipic anhydride.

[0089] According to one embodiment of the present invention, carboxyl-functionalized modified epoxy acrylates are synthesized using adipic anhydride. This is because, compared to adipic anhydride, phthalic anhydride exhibits a slightly lower reactivity due to the electron-donating conjugation effect of its benzene ring, while succinic anhydride has a shorter alkyl chain and thus lower flexibility.

[0090] According to one embodiment of the present invention, the method for preparing the carboxyl-functionalized modified epoxy acrylate includes the following steps:

[0091] Bisphenol A type epoxy resin or heterocyclic epoxy resin is esterified with acrylic acid to obtain an intermediate, and the intermediate is reacted with adipic anhydride to obtain the carboxyl-functionalized modified epoxy acrylate.

[0092] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0093] Esterification of bisphenol A type epoxy resin or heterocyclic epoxy resin with acrylic acid introduces unsaturated carbon-carbon double bonds, resulting in carboxyl-functionalized modified epoxy acrylates that can participate in photocuring reactions. Esterification of the intermediate's side-chain hydroxyl groups with adipic anhydride introduces terminal carboxyl groups, facilitating subsequent alkali-soluble film removal. During the preparation of carboxyl-functionalized modified epoxy acrylates, it is necessary to control the number of carboxyl groups introduced and to ensure the acid value is neither too high nor too low.

[0094] Specifically, in the method for preparing carboxyl-functionalized bisphenol A epoxy resin, the bisphenol A epoxy resin is ring-opened and esterified with acrylic acid to become an oligomer capable of photocuring. Then, adipic anhydride is used to react with the secondary hydroxyl groups obtained after ring-opening the epoxy groups, introducing carboxyl groups and making the resin alkali-soluble. The resulting oligomer contains carboxyl, acryloyl, and bisphenol A structures simultaneously. The presence of a benzene ring in the molecular chain gives the resin excellent chemical resistance and high-temperature resistance, while the carboxyl groups facilitate adhesion and alkali-soluble film removal.

[0095] Specifically, in the method for preparing carboxyl-functionalized heterocyclic epoxy resin, triglycidyl isocyanurate (TGIC) is used as the raw material. Generally, TGIC consists of micron-sized particles that require grinding and solvent dispersion before use, making it inconvenient to handle. This invention creatively uses acrylic acid to open the epoxy groups of TGIC, transforming the originally thermally polymerizable powdered TGIC into a photocurable liquid oligomer. Then, adipic anhydride is used to react with the secondary hydroxyl groups obtained after the epoxy group ring-opening, introducing carboxyl groups and giving the resin alkali solubility. The resulting oligomer contains carboxyl groups, acryloyl groups, and a rigid urea ring structure. The three polar nitrogen atoms on the urea ring and the planar urea ring structure provide a large intermolecular contact area, resulting in excellent adhesion, chemical resistance, and abrasion resistance. The presence of carboxyl groups facilitates adhesion and alkali-soluble film removal.

[0096] According to one embodiment of the present invention, the molar ratio of bisphenol A epoxy resin, acrylic acid and adipic anhydride is 1:2-2.2:1-2.5.

[0097] According to one embodiment of the present invention, the molar ratio of bisphenol A epoxy resin, acrylic acid and adipic anhydride is 1:2-2.2:1-2.4.

[0098] According to one embodiment of the present invention, the molar ratio of bisphenol A epoxy resin, acrylic acid and adipic anhydride is 1:2-2.2:1-1.5.

[0099] According to one embodiment of the present invention, when the molar ratio of bisphenol A type epoxy resin, acrylic acid, and adipic anhydride is 1:2.2:1, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 30 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0100] According to one embodiment of the present invention, when the molar ratio of bisphenol A type epoxy resin, acrylic acid, and adipic anhydride is 1:2.2:1.5, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 45 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0101] According to one embodiment of the present invention, when the molar ratio of bisphenol A type epoxy resin, acrylic acid, and adipic anhydride is 1:2.2:2.4, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 53 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0102] According to one embodiment of the present invention, the molar ratio of heterocyclic epoxy resin, acrylic acid and adipic anhydride is 1:3-3.5:1-3.5.

[0103] According to one embodiment of the present invention, the molar ratio of heterocyclic epoxy resin, acrylic acid and adipic anhydride is 1:3-3.5:1-3.3.

[0104] According to one embodiment of the present invention, the molar ratio of heterocyclic epoxy resin, acrylic acid and adipic anhydride is 1:3-3.5:2.5-3.3.

[0105] According to one embodiment of the present invention, when the molar ratio of heterocyclic epoxy resin, acrylic acid, and adipic anhydride is 1:3.5:1.3, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 28 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0106] According to one embodiment of the present invention, when the molar ratio of heterocyclic epoxy resin, acrylic acid, and adipic anhydride is 1:3.5:2.5, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 47 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0107] According to one embodiment of the present invention, when the molar ratio of heterocyclic epoxy resin, acrylic acid, and adipic anhydride is 1:3.5:3.3, the resulting carboxyl-functionalized modified epoxy acrylate has an acid value of 60 mg KOH / g. The acrylic acid and adipic anhydride are used in appropriate excess amounts.

[0108] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0109] This invention designs and synthesizes carboxyl-functionalized modified epoxy acrylate with a suitable acid value, and uses it in ink formulations, enabling the inks of this invention to meet the performance requirements for film removal in dilute alkaline solutions. This is because, in alkaline solutions, the carboxyl groups in the carboxyl-functionalized modified epoxy acrylate react with NaOH to form sodium carboxylate, which is aqueous and meets the film removal requirements. Furthermore, heating the ester groups in an alkaline environment intensifies alkaline hydrolysis, breaking down the ester groups and causing molecular chain breakage, which also further facilitates film removal.

[0110] This invention uses carboxyl-functionalized modified epoxy acrylate with a suitable acid value to ensure that the ink has excellent alkali solubility, thereby ensuring the film removal performance. At the same time, the suitable acid value also avoids damaging the service life of the printhead used in inkjet printing.

[0111] Another aspect of the present invention also provides a circuit board. It includes an inkjet material, as described in the first aspect embodiment, printed on its surface using inkjet technology. Since this application employs all the technical solutions of the aforementioned inkjet material, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0112] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0113] In the description of this invention, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or implicitly indicating the order of the technical features indicated.

[0114] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0115] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0116] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present invention.

[0117] Unless otherwise specified, the reagents, methods and equipment used in this invention are all conventional reagents, methods and equipment in this technical field.

[0118] The acid value of the resin is considered low if it is between 20 and 30 mg KOH / g, medium if it is between 45 and 48 mg KOH / g, and high if it is greater than 50 mg KOH / g. Considering that the inkjet material of this invention needs to be used in solder resist inks, using a low-acid-value resin would result in unclean development, while using a high-acid-value resin would lead to excessive side etching after development. Furthermore, the inkjet material of this invention is used for printhead printing, which also requires a low acid value to prevent printhead corrosion. Therefore, a medium-acid-value resin is used in the examples and comparative examples.

[0119] The preparation method of carboxyl-functionalized modified bisphenol A epoxy resin in the examples and comparative examples includes the following steps:

[0120] Bisphenol A diglycidyl ether was esterified with acrylic acid to obtain an intermediate. The intermediate was then reacted with adipic anhydride to obtain the above-mentioned carboxyl-functionalized modified bisphenol A epoxy resin.

[0121] In the examples and comparative examples, considering the acid value factor, the molar ratio of bisphenol A diglycidyl ether, acrylic acid, and adipic anhydride in the preparation method of the carboxyl-functionalized modified bisphenol A epoxy resin was 1:2.2:1.5. The resulting carboxyl-functionalized modified bisphenol A epoxy resin had an acid value of 45 mg KOH / g, belonging to a medium acid value resin. The viscosity of the above carboxyl-functionalized modified bisphenol A epoxy resin at 25°C was approximately 1100–1200 cp. The structural formula of the above carboxyl-functionalized modified bisphenol A epoxy resin is as follows:

[0122]

[0123] The preparation method of the carboxyl-functionalized modified heterocyclic epoxy resin in the examples and comparative examples includes the following steps:

[0124] Triglycidyl isocyanurate was esterified with acrylic acid to obtain an intermediate, which was then reacted with adipic anhydride to obtain the above-mentioned carboxyl-functionalized modified heterocyclic epoxy resin.

[0125] In the examples and comparative examples, considering the acid value factor, the molar ratio of triglycidyl isocyanate, acrylic acid, and adipic anhydride in the preparation method of the carboxyl-functionalized modified heterocyclic epoxy resin was 1:3.5:2.5. The resulting carboxyl-functionalized modified heterocyclic epoxy resin had an acid value of 47 mg KOH / g, belonging to a medium acid value resin. The above-mentioned carboxyl-functionalized modified heterocyclic epoxy resin has a viscosity of approximately 500–700 cp at 60°C. The structural formula of the above-mentioned carboxyl-functionalized modified heterocyclic epoxy resin is as follows:

[0126] In the examples and comparative examples, the amine-modified polyether acrylate was Rahn's Genomer*3364, which has a viscosity of approximately 130 cp at 25°C, an amine value of 55-65 mg KOH / g, low shrinkage, good flexibility, good chemical resistance, and relatively good adhesion to metal surfaces.

[0127] In the examples and comparative examples, the nano-barium sulfate used was VENATOR brand HU-N, with a particle size of D. 100 ≤0.1μm, D 50 =0.04μm.

[0128] In the examples and comparative examples, the adhesion promoter was Rahn's Genomer*40, a phosphate ester monomer with an acid value of 295 mg KOH / g.

[0129] In the examples and comparative examples, the polymerization inhibitor was Rahn's Genomer*16.

[0130] In the examples and comparative examples, the leveling agent was BYK 379 from BYK, which is a polyether-modified siloxane that reduces surface tension and wets the substrate.

[0131] In the examples and comparative examples, the nano blue paste comprises the following components in parts by weight:

[0132] PET3A, 30 portions;

[0133] Phthalocyanine Blue M3K8, 20 portions;

[0134] BASF efka 4310, 10 copies.

[0135] In the examples and comparative examples, the steps for preparing the nano blue paste are as follows: according to the formula amount, the acrylate monomer PET3A and the dispersant BASF efka 4310 are mixed evenly, then phthalocyanine blue M3K8 is added, and then the mixture is stirred at high speed and dispersed evenly. Finally, the mixture is added to a sand mill and circulated and ground until D95≤700nm to obtain the nano blue paste.

[0136] Example 1

[0137] An inkjet material comprising the following components in parts by weight:

[0138] Photoinitiator, 7.1 parts;

[0139] UV monomer, 53 parts;

[0140] Carboxyl-functionalized modified epoxy acrylate, 15 parts;

[0141] Amine-modified polyether acrylate, 10 parts;

[0142] Filler, 10 parts;

[0143] Nano blue paste, 4 parts;

[0144] Additives, 0.4 parts.

[0145] The aforementioned photoinitiators include TMO, ITX, 907, and 784.

[0146] The aforementioned UV monomers include HDDA, ACMO, PHEA, and TMCHA.

[0147] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 10 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 10 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0148] The filler material mentioned above is nano-barium sulfate.

[0149] The aforementioned additives include polymerization inhibitors and leveling agents.

[0150] The preparation of the above inkjet material includes the following steps:

[0151] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0152] Example 2

[0153] An inkjet material comprising the following components in parts by weight:

[0154] Photoinitiator, 7.1 parts;

[0155] UV monomer, 53 parts;

[0156] Carboxyl-functionalized modified epoxy acrylate, 15 parts;

[0157] Amine-modified polyether acrylate, 10 parts;

[0158] Filler, 10 parts;

[0159] Nano blue paste, 4 parts;

[0160] Additives, 0.4 parts.

[0161] The aforementioned photoinitiators include TMO, ITX, 907, and 784.

[0162] The aforementioned UV monomers include HDDA, ACMO, PHEA, TMCHA, and TMPTA.

[0163] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 10 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 5 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0164] The filler material mentioned above is nano-barium sulfate.

[0165] The aforementioned additives include polymerization inhibitors and leveling agents.

[0166] The preparation of the above inkjet material includes the following steps:

[0167] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0168] Example 3

[0169] An inkjet material comprising the following components in parts by weight:

[0170] Photoinitiator, 7.1 parts;

[0171] UV monomer, 53 parts;

[0172] Carboxyl-functionalized modified epoxy acrylate, 20 parts;

[0173] Amine-modified polyether acrylate, 10 parts;

[0174] Filler, 5 parts;

[0175] Nano blue paste, 4 parts;

[0176] Additives, 0.4 parts.

[0177] The aforementioned photoinitiators include TMO, ITX, 907, and 784.

[0178] The aforementioned UV monomers include HDDA, ACMO, PHEA, TMCHA, and TMPTA.

[0179] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 15 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 5 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0180] The filler material mentioned above is nano-barium sulfate.

[0181] The aforementioned additives include polymerization inhibitors and leveling agents.

[0182] The preparation of the above inkjet material includes the following steps:

[0183] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0184] Example 4

[0185] An inkjet material comprising the following components in parts by weight:

[0186] Photoinitiator, 7 parts;

[0187] UV monomer, 53 parts;

[0188] Carboxyl-functionalized modified epoxy acrylate, 20 parts;

[0189] Amine-modified polyether acrylate, 10 parts;

[0190] Filler, 5 parts;

[0191] Nano blue paste, 4 parts;

[0192] Additives, 0.4 parts.

[0193] The aforementioned photoinitiators include TMO, ITX, and 907.

[0194] The aforementioned UV monomers include HDDA, ACMO, PHEA, TMCHA, and TMPTA.

[0195] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 15 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 5 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0196] The filler material mentioned above is nano-barium sulfate.

[0197] The aforementioned additives include polymerization inhibitors and leveling agents.

[0198] The preparation of the above inkjet material includes the following steps:

[0199] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0200] Example 5

[0201] An inkjet material comprising the following components in parts by weight:

[0202] Photoinitiator, 7.1 parts;

[0203] UV monomer, 53 parts;

[0204] Carboxyl-functionalized modified epoxy acrylate, 10 parts;

[0205] Amine-modified polyether acrylate, 10 parts;

[0206] Filler, 15 parts;

[0207] Nano blue paste, 4 parts;

[0208] Additives, 0.4 parts.

[0209] The aforementioned photoinitiators include TMO, ITX, 907, and 784.

[0210] The aforementioned UV monomers include HDDA, ACMO, PHEA, TMCHA, and TMPTA.

[0211] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 5 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 5 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0212] The filler material mentioned above is nano-barium sulfate.

[0213] The aforementioned additives include polymerization inhibitors and leveling agents.

[0214] The preparation of the above inkjet material includes the following steps:

[0215] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0216] Example 6

[0217] An inkjet material comprising the following components in parts by weight:

[0218] Photoinitiator, 7.1 parts;

[0219] UV monomer, 53 parts;

[0220] Carboxyl-functionalized modified epoxy acrylate, 15 parts;

[0221] Amine-modified polyether acrylate, 10 parts;

[0222] Filler, 10 parts;

[0223] Nano blue paste, 4 parts;

[0224] Additives, 0.4 parts.

[0225] The aforementioned photoinitiators include TMO, ITX, 907, and 784.

[0226] The aforementioned UV monomers include HDDA, ACMO, PHEA, and TMCHA.

[0227] The aforementioned carboxyl-functionalized modified epoxy acrylate comprises 10 parts by weight of carboxyl-functionalized modified bisphenol A type epoxy resin and 10 parts by weight of carboxyl-functionalized modified heterocyclic epoxy resin.

[0228] The filler material mentioned above is nano-barium sulfate.

[0229] The aforementioned additives include polymerization inhibitors, leveling agents, and phosphate ester monomer adhesion promoters.

[0230] The preparation of the above inkjet material includes the following steps:

[0231] Under light-protected conditions, a photoinitiator, UV monomer, carboxyl-functionalized epoxy acrylate, and amine-modified polyether acrylate were mixed and stirred at 1200 rpm for 2 hours to obtain a transparent oil. Filler and nano blue paste were added, and stirring was continued at 800 rpm for 2 hours. After filtration through two 1μm filter cartridges, inkjet material was obtained.

[0232] Comparative Example 1

[0233] The difference between Comparative Example 1 and Example 1 is that the inkjet material of Comparative Example 1 does not use carboxyl-functionalized heterocyclic epoxy resin. Furthermore, to meet the requirement of 15 parts of carboxyl-functionalized epoxy acrylate, the amount of carboxyl-functionalized bisphenol A epoxy resin in Comparative Example 1 was adjusted to 15 parts.

[0234] Comparative Example 2

[0235] The difference between Comparative Example 2 and Example 1 is that the inkjet material of Comparative Example 2 does not use carboxyl-functionalized bisphenol A type epoxy resin. Furthermore, to meet the requirement of 15 parts of carboxyl-functionalized epoxy acrylate, Comparative Example 2 adjusts the amount of carboxyl-functionalized heterocyclic epoxy resin used to 15 parts.

[0236] Comparative Example 3

[0237] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses the trifunctional monomer TMPTA instead of the trifunctional amine-modified polyether acrylate Genomer*3364.

[0238] The formulations of the inkjet materials of Examples 1-6 and Comparative Examples 1-3 are summarized in Table 1.

[0239] Table 1

[0240]

[0241] Performance testing:

[0242] The viscosity and surface tension of the inkjet materials obtained in Examples 1-3 and Comparative Examples 1-6 were tested. Using a Konica printhead (KM1024i, printhead temperature 55°C) and a 395nm wavelength LED-UV lamp, the obtained inkjet material was printed onto a polished copper-clad laminate (plain board) to form 10x10cm square patterns, followed by UV curing. The adhesion, hardness, solvent resistance, and acid etching resistance of the cured film were tested to evaluate the thermal storage properties of the inkjet. Specific tests are as follows:

[0243] 1. Viscosity: GB / T 10247-2008 Viscosity Measurement Method. Viscosity was tested using a Brookfield DV2T+Pro rotational viscometer.

[0244] 2. Surface tension: GB / T 22237-2008 Determination of surface tension of surfactants. Platinum plate method.

[0245] 3. Pencil hardness: GB / T 6739-2006 Pencil method for determining the hardness of paint and varnish film.

[0246] 4. Adhesion: GB / T 9286-2021 Cross-cut test for paint and varnish film.

[0247] Acid etching treatment: ferric oxide etching was performed using ferric chloride (FeCl3) as a spray etchant at approximately 4.0 lb / gal, with an acid (HCl) content of 1.5–2%. Adhesion was then tested using a cross-cut adhesion test to characterize the acid etching resistance.

[0248] 5. Storage stability: QB / T 5604-2021 Light-curable inkjet ink for circuit boards. Store at 60℃ in a sealed container away from light for 7 days.

[0249] Test the percentage increase in viscosity before and after heat storage: Δη% < 10%, indicating good storage stability; Δ% > 10%, indicating poor storage stability.

[0250] Table 2 Test Results

[0251]

[0252] As shown in Table 2, Examples 1-3 exhibit superior performance in all aspects. Specifically, the combination of carboxyl-functionalized bisphenol A epoxy resin, carboxyl-functionalized heterocyclic epoxy resin, and amine-modified polyether acrylate results in excellent performance in Examples 1-3. Carboxyl functionalization improves adhesion and film removal; the carboxyl-functionalized bisphenol A epoxy resin provides good flexibility, adhesion, and temperature resistance; the polar triaza rings, rigidity, and corrosion resistance of the carboxyl-functionalized heterocyclic epoxy resin; and the amine-modified polyether acrylate offers low shrinkage and good flexibility. The combined performance of these three components is excellent.

[0253] Compared to Example 1, the ink of Comparative Example 1 did not use a carboxyl-functionalized heterocyclic epoxy resin, resulting in a lower degree of crosslinking and slightly lower hardness (only 3H). Its adhesion and acid etching resistance were also inferior to those of Example 1.

[0254] Compared to Example 1, the ink of Comparative Example 2 did not use carboxyl-functionalized bisphenol A epoxy resin, resulting in slightly lower flexibility. Furthermore, the use of 15 parts of carboxyl-functionalized heterocyclic epoxy resin led to a higher degree of crosslinking and slightly higher hardness (5H) in the product compared to Example 1. The ink of Comparative Example 2 had a higher viscosity, stronger intermolecular polar forces, and was prone to flocculation, leading to increased viscosity and poor storage stability.

[0255] Compared with Example 1, the ink of Comparative Example 3 uses the trifunctional monomer TMPTA instead of the trifunctional amine-modified polyether acrylate Genomer*3364. Due to the larger shrinkage rate of TMPTA, the ink of Comparative Example 3 is more brittle than that of Comparative Example 1 and has slightly worse adhesion.

[0256] Compared with Example 3, the ink in Example 4 does not use 784 photoinitiator, resulting in weaker deep curing. Consequently, when acid etching is performed on the copper below the edge of the mask covering the copper surface, the etching depth (also called undercut) is slightly greater than that in Comparative Example 3, and the adhesion is slightly worse.

[0257] Compared with Example 2, the ink of Example 5 uses less carboxyl-functionalized resin 1, resulting in poorer adhesion. The amount of nano-barium sulfate used is 15%. Although nano-barium sulfate can alleviate the volume shrinkage stress during photocuring, the excessive amount can easily cause sedimentation, which is not conducive to storage and use, and results in poor storage stability.

[0258] Compared to Example 1, the ink in Example 6 uses a phosphate ester monomer as an adhesion promoter, resulting in better adhesion to metal surfaces. However, phosphate ester monomers generally have high acid values; the Genomer*40 used has an acid value of 295 mg KOH / g. During storage, the ink viscosity increases, affecting storage stability, printhead life, and making it unsuitable for storage and use, resulting in poor storage stability.

[0259] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An inkjet material, characterized by: Includes the following components in parts by weight: Photoinitiator, 4-8 parts; UV monomer, 40-60 parts; Filler, 5-20 parts; Carboxyl-functionalized modified epoxy acrylate, 5-15 parts; Amine-modified polyether acrylate, 5-10 parts; The acid value of the carboxyl-functionalized modified epoxy acrylate is 45-47 mg KOH / g; The carboxyl-functionalized modified epoxy acrylate includes carboxyl-functionalized bisphenol A type epoxy resin and carboxyl-functionalized heterocyclic epoxy resin. The structural formula of the carboxyl-functional modified bisphenol A type epoxy resin is: or ; The structural formula of the carboxyl-functional modified heterocyclic epoxy resin is: , or .

2. An inkjet material according to claim 1, wherein: The photoinitiator includes at least one of the following: a pyrolysis-type free radical photoinitiator, a hydrogen abstraction-type free radical photoinitiator, and a visible light initiator.

3. A method for preparing an inkjet material as described in any one of claims 1 or 2, characterized in that: Includes the following steps: Under light-protected conditions, a photoinitiator, a UV monomer, a carboxyl-functionalized epoxy acrylate, an amine-modified polyether acrylate, and a filler are mixed to obtain the inkjet material.

4. The method of claim 3, wherein: The method for preparing the carboxyl-functionalized modified epoxy acrylate includes the following steps: Bisphenol A type epoxy resin or heterocyclic epoxy resin is esterified with acrylic acid to obtain an intermediate. The intermediate is then reacted with adipic anhydride to obtain the carboxyl-functionalized modified epoxy acrylate.

5. The method of claim 4, wherein: The molar ratio of the bisphenol A type epoxy resin, acrylic acid and adipic anhydride is 1:2-2.2:1-2.

5.

6. The method of claim 5, wherein: The molar ratio of the heterocyclic epoxy resin, acrylic acid, and adipic anhydride is 1:3-3.5:1-3.

5.

7. A circuit board, characterized by: Including inkjet materials as described in any one of claims 1 or 2, which are printed on a surface using inkjet technology.

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