A kind of printing circuit ink and preparation method thereof

Abstract

The present invention relates to a printing circuit ink and a preparation method thereof, wherein the printing circuit ink comprises the following components by weight: 50-100 parts of active monomers, 10-20 parts of acrylic resins, 5-20 parts of modified fillers, 1-10 parts of photoinitiators, and 1-10 parts of auxiliary agents; wherein the modified filler is epoxy resin-modified boron nitride. The epoxy resin is a bisphenol epoxy resin. The acrylic resin is a carboxyl-containing polyester acrylic resin. The present invention effectively improves the compatibility between components, improves the adhesion and stability of the ink, further improves the strength of the product, can meet the performance requirements of the printing circuit ink, and solves the problems existing in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of PCB ink, and in particular to a printing circuit ink and a preparation method thereof. Background Art

[0002] With the advancement of inkjet digital printing technology and the emergence of special print heads and special inks, the accuracy and printing speed of PCB printing lines have been significantly improved.

[0003] Due to the characteristics of digital inkjet printing technology, such as fast, flexible and low-cost, the printing process has gradually replaced the screen printing with many processes, complicated operations and high costs for the production of samples, multiple varieties and low-batch PCB products. It can not only improve production efficiency and reduce costs, but also help reduce pollution and emissions and achieve green production.

[0004] PCB boards have extremely high precision and performance requirements. The printed circuit ink cannot crack, discolor, or detach during the preparation of the PCB board. It must meet many performance requirements such as adhesion, insulation, heat resistance, acid and alkali resistance, and solvent resistance. In the ink composition, inorganic components are usually added as fillers. However, inorganic fillers have poor compatibility with organic resins and polymers, and are prone to uneven dispersion and agglomeration after mixing, which affects the adhesion, mechanical strength, and stability of the product, and ultimately reduces the precision and performance of the PCB board. To solve the above problems, the prior art uses organic materials such as silane coupling agents to modify the fillers. However, this type of technical solution still has the defects of complex modification process, high material cost, and unsatisfactory performance improvement, and cannot meet the requirements of practical applications.

[0005] In summary, it is necessary to develop a new technical solution to solve the deficiencies in the prior art. Summary of the invention

[0006] Based on this, the present invention provides a printing circuit ink and a preparation method thereof. The present invention adopts a carboxyl-containing polyester acrylic resin, a modified filler and other ingredients to effectively improve the compatibility between the components, enhance the adhesion and stability of the ink, further improve the strength of the product, meet the performance requirements of the printing circuit ink, and solve the problems existing in the prior art.

[0007] One object of the present invention is to provide a printing circuit ink, wherein the printing circuit ink comprises the following components in parts by weight:

[0008]

[0009] in,

[0010] The modified filler is epoxy resin modified boron nitride.

[0011] Furthermore, the particle size D100 of the modified filler is less than 1 μm.

[0012] Furthermore, the epoxy resin is a bisphenol epoxy resin.

[0013] Furthermore, the acrylic resin is a carboxyl-containing polyester acrylic resin.

[0014] Furthermore, the carboxyl-containing polyester acrylic resin is selected from one or more of a copolymer of maleic anhydride and hydroxyethyl acrylate, a copolymer of epoxy acrylate and anhydride, and a carboxyl polyurethane acrylate.

[0015] Furthermore, the acid value of the carboxyl-containing polyester acrylic resin is 200 mgKOH / g.

[0016] Furthermore, the active monomer is selected from acrylate or acrylate derivatives.

[0017] Furthermore, the auxiliary agent is selected from one or more of color powder, defoaming agent, leveling agent, dispersant, toughening agent, antioxidant, and ultraviolet absorber.

[0018] Another object of the present invention is to provide a method for preparing the above-mentioned inkjet printing circuit ink, the method for preparing the inkjet printing circuit ink comprising the following steps:

[0019] S1, adding boron nitride to a mixture of concentrated sulfuric acid and nitric acid, and subjecting it to ultrasonic heating treatment to obtain hydroxylated boron nitride;

[0020] S2, dispersing the hydroxylated boron nitride in a solvent, then adding epoxy resin and a catalyst, and heating for reaction to obtain a modified filler;

[0021] S3, blending the modified filler with other ingredients, stirring and dispersing them uniformly, grinding and filtering to obtain a product.

[0022] Furthermore, in step S1, the temperature of the ultrasonic heating treatment is 50-70°C and the time is 3-6h.

[0023] Furthermore, in step S2, the heating reaction temperature is 100-150°C and the time is 2-5h.

[0024] Furthermore, the molar ratio of the hydroxylated boron nitride to the epoxy resin is 1:(0.5-2).

[0025] The present invention has the following beneficial effects:

[0026] In the inkjet printing circuit provided by the present invention, boron nitride is firstly subjected to hydroxylation treatment, and then mixed with bisphenol A epoxy resin for reaction. After the epoxy group at the end of the bisphenol A epoxy resin molecule reacts with the active hydroxyl group on the surface of the hydroxylated boron nitride, a large number of benzene rings, alkyl chains and other groups are introduced on the surface of the boron nitride, thereby enhancing the lipophilicity and dispersibility of the inorganic filler, avoiding the agglomeration of the filler, and also improving the affinity of the modified filler with the organic polymer. A network structure can be formed by winding between multiple components, thereby improving the stability and strength of the ink. The surface of the modified filler also has an epoxy group, which can be chemically cross-linked with components such as carboxyl-containing polyester acrylic resin and a polymerized monomer having a large number of hydroxyls, and can form intermolecular forces between the components, thereby generating a synergistic effect, further improving the adhesion, mechanical properties and stability of the ink, achieving better printing and protective effects, and having good application prospects. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0028] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.

[0029] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that vary depending on the desired properties to be obtained by the present invention.

[0030] The active monomers in the embodiment of the present invention are trimethylolpropane triacrylate (TMPTA) and polydipentaerythritol hexaacrylate (DPHA).

[0031] The acrylic resin in the embodiment of the present invention is a copolymer of acrylic acid ester and anhydride, the brand is Sartomer SB520A20, and the acid value is 200 mgKOH / g (content 80%)

[0032] The photoinitiators in the embodiments of the present invention are ITX and 819.

[0033] The auxiliary agent in the embodiment of the present invention is a leveling agent isopropyl alcohol and a dispersant sodium dodecyl sulfate in a mass ratio of 1:1.

[0034] The epoxy resin in the embodiment of the present invention is bisphenol A epoxy resin, and the brand is Sanmu SM827.

[0035] The "parts" in the embodiments of the present invention refer to parts by mass.

[0036] Example 1

[0037] A printing ink comprises the following components in parts by weight:

[0038]

[0039] The method for preparing the ink for printing circuit comprises the following steps:

[0040] S1, immersing the boron nitride in a mixed solution of concentrated sulfuric acid and nitric acid in a volume ratio of 1:3 (the concentration of concentrated sulfuric acid is 18.4 mol / L, and the concentration of nitric acid is 1 mol / L), ultrasonically treating at 60°C for 5 h, washing and drying to obtain hydroxylated boron nitride;

[0041] S2, using xylene as solvent, adding the hydroxylated boron nitride, ultrasonically dispersing for 30 minutes, then adding epoxy resin (the molar ratio of hydroxylated boron nitride to epoxy resin is 4:6), then adding 0.2wt% of stannous chloride to the system, stirring at 120°C for 4 hours, centrifuging, washing, and drying to obtain a modified filler;

[0042] S3. Blend the modified filler and other ingredients according to the above mass fractions, stir and disperse them uniformly, and grind them to a fineness of less than 1 μm to obtain a product.

[0043] Example 2

[0044] A printing ink comprises the following components in parts by weight:

[0045]

[0046] The method for preparing the ink for printing circuit comprises the following steps:

[0047] S1, immersing the boron nitride in a mixed solution of concentrated sulfuric acid and nitric acid in a volume ratio of 1:3 (the concentration of concentrated sulfuric acid is 18.4 mol / L, and the concentration of nitric acid is 1 mol / L), ultrasonically treating at 60°C for 5 h, washing and drying to obtain hydroxylated boron nitride;

[0048] S2, using xylene as solvent, adding the hydroxylated boron nitride, ultrasonically dispersing for 30 minutes, then adding epoxy resin (the molar ratio of hydroxylated boron nitride to epoxy resin is 4:6), then adding 0.2wt% of stannous chloride to the system, stirring at 120°C for 4 hours, centrifuging, washing, and drying to obtain a modified filler;

[0049] S3. Blend the modified filler and other ingredients according to the above mass fractions, stir and disperse them uniformly, and grind them to a fineness of less than 1 μm to obtain a product.

[0050] Example 3

[0051] A printing ink comprises the following components in parts by weight:

[0052]

[0053] The method for preparing the ink for printing circuit comprises the following steps:

[0054] S1, immersing the boron nitride in a mixed solution of concentrated sulfuric acid and nitric acid in a volume ratio of 1:3 (the concentration of concentrated sulfuric acid is 18.4 mol / L, and the concentration of nitric acid is 1 mol / L), ultrasonically treating at 60°C for 5 h, washing and drying to obtain hydroxylated boron nitride;

[0055] S2, using xylene as solvent, adding the hydroxylated boron nitride, ultrasonically dispersing for 30 minutes, then adding epoxy resin (the molar ratio of hydroxylated boron nitride to epoxy resin is 4:6), then adding 0.2wt% of stannous chloride to the system, stirring at 120°C for 4 hours, centrifuging, washing, and drying to obtain a modified filler;

[0056] S3. Blend the modified filler and other ingredients according to the above mass fractions, stir and disperse them uniformly, and grind them to a fineness of less than 1 μm to obtain a product.

[0057] Comparative Example 1

[0058] A printing circuit ink, the difference between this comparative example and Example 1 is that the modified filler and other qualities are replaced by unmodified boron nitride, and the other ingredients and preparation method are the same as those of Example 1.

[0059] Comparative Example 2

[0060] A printing circuit ink, the difference between this comparative example and Example 1 is that the mass of the modified filler is replaced by a mixture of unmodified boron nitride and epoxy resin (molar ratio is 4:6), and the other ingredients and preparation method are the same as those in Example 1.

[0061] Test Case

[0062] The performance of the inkjet printing circuit inks prepared in Examples 1-3 and Comparative Examples 1-2 was tested.

[0063] The test method is as follows:

[0064] The inkjet printing circuit inks prepared in the examples and comparative examples were applied to the PCB boards respectively and photocured for 1 h (wavelength 395 nm, intensity 25.0 mW / cm 2 The film was then cured at 150 °C for 1 h to form a 0.5 mm thick film.

[0065] Adhesion: Use a needle tip to make an "X" on the film, then stick a cellophane tape on the cut and pull it, and evaluate based on the following criteria:

[0066] Good: no tearing or little tearing;

[0067] Poor: Extensive tear-off.

[0068] Bending resistance: Bend 180° with the ink film on the outside and evaluate based on the following criteria:

[0069] Good: No cracks on the film;

[0070] Poor: There are cracks on the film.

[0071] Heat resistance: Thermal shock performance test is carried out according to the method in IPC-SM-840E, and the judgment criteria are as follows:

[0072] Good: no bubbles or cracks;

[0073] Poor: bubbles and cracks appear.

[0074] Acid resistance / alkali resistance: At 20°C, immerse the PCB coated with ink in a 10% sulfuric acid solution or a 10% sodium hydroxide solution, take it out after 30 minutes, and evaluate the state and adhesion of the coating. The judgment criteria are as follows:

[0075] Good: No changes or slight changes were found;

[0076] Poor: The coating film expands or swells and falls off.

[0077] Film removal: Soak the sample in 5% sodium hydroxide solution at 50°C for 5 minutes. The criteria are as follows:

[0078] Good: Complete film removal;

[0079] Poor: The film cannot be removed.

[0080] The test results are shown in Table 1.

[0081] Table 1 Performance test results

[0082] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Appearance smooth smooth smooth Rough Rough Adhesion good good good Poor good Bending resistance good good good Poor Poor Heat resistance good good good Poor Poor Acid resistance good good good Poor Poor Alkali resistance good good good Poor Poor Film removal good good good good good

[0083] According to Table 1, it can be seen that the inkjet printing circuit ink prepared by Examples 1-3 of the present invention has excellent adhesion and strength, good heat resistance, acid and alkali resistance, and strong stability; Comparative Example 1-2 replaces the modified filler with unmodified boron nitride, or only physically blends boron nitride and epoxy resin, resulting in poor dispersion of the components, and the compatibility of the filler with the organic polymer is not ideal, and a more stable, three-dimensional cross-linked structure cannot be formed, and various properties of the ink are significantly reduced. In summary, the inkjet printing circuit ink of the present invention has good performance, overcomes the defects existing in the prior art, and is of great significance to the development and application of inkjet printing ink.

[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0085] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A printing circuit ink, characterized in that: The ink for printing circuits comprises the following components in parts by weight: Active monomer 50-100 parts Acrylic resin 10-20 parts Modified filler 5-20 parts Photoinitiator 1-10 parts 1-10 parts of additives; in, The modified filler is epoxy resin modified boron nitride; The acrylic resin is a carboxyl-containing polyester acrylic resin; The carboxyl-containing polyester acrylic resin is a copolymer of acrylate and anhydride; The method for preparing the ink for printing circuit comprises the following steps: S1, adding boron nitride to a mixture of concentrated sulfuric acid and nitric acid, and subjecting it to ultrasonic heating treatment to obtain hydroxylated boron nitride; S2, dispersing the hydroxylated boron nitride in a solvent, then adding epoxy resin and a catalyst, and heating for reaction to obtain a modified filler; S3, blending the modified filler with other ingredients, stirring and dispersing them uniformly, grinding and filtering to obtain a product.

2. The ink for printing circuit according to claim 1, characterized in that: The epoxy resin is a bisphenol epoxy resin.

3. The ink for printing circuit according to claim 1, characterized in that: The active monomer is selected from acrylate or acrylate derivatives.

4. The ink for printing circuit according to claim 1, characterized in that: The auxiliary agent is selected from one or more of toner, defoamer, leveling agent, dispersant, toughening agent, antioxidant, and ultraviolet absorber.

5. The ink for printing circuit according to claim 1, characterized in that: In step S1, the temperature of the ultrasonic heating treatment is 50-70°C and the time is 3-6 hours.

6. The ink for printing circuit according to claim 1, characterized in that: In step S2, the heating reaction temperature is 100-150°C and the time is 2-5 h.

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