Solder resist ink based on halogen-free chemical-resistant epoxy acrylic resin and preparation method of solder resist ink

Abstract

The invention provides a solder resist ink based on halogen-free chemical-resistant epoxy acrylic resin and a preparation method thereof, the solder resist ink based on halogen-free chemical-resistant epoxy acrylic resin comprises a component A and a component B. The component A comprises the following components: acrylic resin, modified inorganic particles, a polymeric monomer, a photoinitiator, an auxiliary agent and a solvent; the component B comprises the following components: halogen-free chemical-resistant epoxy acrylic resin, epoxy resin, an auxiliary agent and a solvent; wherein the modified inorganic particles are products obtained by reacting a silane coupling agent, acrylic acid and hexagonal boron nitride. Compared with the prior art, the compatibility among different substances is obviously improved, and a synergistic interaction effect can be exerted, so that improvement of various properties such as adhesive force, chemical resistance and stability of the solder resist ink is promoted, a new idea is provided for development of solder resist ink products, and the solder resist ink has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of solder resist ink, in particular to a solder resist ink based on halogen-free and chemical resistance epoxy acrylate resin and a preparation method thereof. BACKGROUND

[0002] In the field of printed circuit board (PCB) manufacturing, solder resist ink, as a key material to protect the circuit from corrosion and short circuit, its performance directly affects the reliability and service life of electronic products. Although the solder resist ink containing halogen components is beneficial to the flame retardation and adhesion of the product, the harmful substances such as dioxin released at high temperature pose a threat to the environment and human health. With the strict limitation of halogen content by environmental protection regulations at home and abroad, the development of halogen-free and high chemical resistance solder resist ink has become the core demand of the industry.

[0003] However, the existing halogen-free solder resist ink still has the following technical bottlenecks: the combination strength between halogen-free acrylate resin, epoxy resin and inorganic filler components is weak, which limits multiple performances. In the manufacturing process of PCB, this weak combination makes the solder resist layer difficult to resist the corrosion of flux, cleaning agent, acid / alkali etching liquid and other chemicals, and the blistering and discoloration phenomenon easily occurs in the gold plating and tin spraying processes, and the adhesion decreases significantly. At the same time, the insufficient combination strength leads to the imbalance of intermolecular forces in the curing process, the introduction of rigid chain segments improves the heat resistance but aggravates the volume shrinkage, causing local stress concentration and causing the curing film to crack and warp. In addition, the component interface defects also make the dielectric constant too high in high frequency environment, which cannot meet the requirement of low dielectric loss for 5G communication, and the side etching amount is generally large when printing fine lines, which affects the pattern precision.

[0004] To solve the above problems, the industry usually adds multifunctional monomers and special epoxy resins to improve the adhesion and chemical resistance, and many technical solutions also modify the nano filler to introduce more active groups. However, these methods still have limitations: the performance-enhancing additives or resins are often high in cost, and only improve specific performance, which is not ideal; the modification of fillers has the problems of complex process and more steps, which is difficult to apply to large-scale industrial production.

[0005] In summary, there is an urgent need to develop a new technical solution to solve the problems in the prior art. SUMMARY

[0006] The application provides a halogen-free resistant epoxy acrylic resin-based solder resist ink and a preparation method thereof, the halogen-free resistant epoxy acrylic resin-based solder resist ink comprises modified inorganic particles, an acrylic resin, a halogen-free resistant epoxy acrylic resin and the like, the compatibility between different substances is obviously improved, a synergistic effect can be played, thereby promoting the improvement of various performances of the solder resist ink such as adhesion, chemical resistance and stability, a new idea is provided for the development of the solder resist ink product, and the halogen-free resistant epoxy acrylic resin-based solder resist ink has a good application prospect.

[0007] An object of the application is to provide a halogen-free resistant epoxy acrylic resin-based solder resist ink, the halogen-free resistant epoxy acrylic resin-based solder resist ink comprises component A and component B,

[0008] The component A comprises the following components in mass fraction:

[0009]

[0010] The component B comprises the following components in mass fraction:

[0011]

[0012] Among them,

[0013] The modified inorganic particles are the product of the reaction of a silane coupling agent, acrylic acid and hexagonal boron nitride.

[0014] Further, the halogen-free resistant epoxy acrylic resin is obtained by the reaction of glycidyl acrylate, alkyl acrylate and styrene.

[0015] Further, the mass ratio of the glycidyl acrylate, the alkyl acrylate and the styrene is (0.1-2):(20-50):(3-8).

[0016] Further, the alkyl acrylate comprises methyl acrylate, butyl acrylate and dodecyl acrylate.

[0017] Further, the mass ratio of the acrylic acid and the hexagonal boron nitride is (0.5-5):1.

[0018] Further, the silane coupling agent is a vinyl silane coupling agent.

[0019] Further, the auxiliary agent comprises an inorganic salt.

[0020] Preferably, the inorganic salt is selected from magnesium nitrate or calcium nitrate.

[0021] Optionally, the auxiliary agent further comprises one or more of a pigment, a leveling agent, a defoaming agent, a toughening agent, a dispersing agent and an ultraviolet absorber.

[0022] Further, the polymerization monomer is an acrylic ester with a single functional group or a multi-functional group.

[0023] Another object of the present application is to provide a preparation method of the solder resist ink based on the halogen-free weather-resistant epoxy acrylic resin, which comprises the following steps:

[0024] S1, blending, stirring glycidyl acrylate, alkyl acrylate, styrene, emulsifier, then adding initiator, heating reaction under inert gas protection, obtaining halogen-free weather-resistant epoxy acrylic resin;

[0025] S2, mixing hexagonal boron nitride, silane coupling agent, heating reaction, then adding acrylic acid, initiator, heating reaction under inert gas protection, obtaining modified inorganic particles;

[0026] S3, mixing acrylic resin, modified inorganic particles, polymerization monomer, photoinitiator, auxiliary agent and solvent, stirring uniformly, obtaining component A; mixing halogen-free weather-resistant epoxy acrylic resin, epoxy resin, auxiliary agent and solvent, obtaining component B; finally mixing the component A and component B, stirring and grinding, obtaining the solder resist ink based on the halogen-free weather-resistant epoxy acrylic resin.

[0027] Further, in step S1, the heating reaction temperature is 50-100℃.

[0028] Further, in step S2, the heating reaction temperature is 60-100℃.

[0029] The present application has the following beneficial effects:

[0030] The present application provides a solder resist ink based on halogen-free weather-resistant epoxy acrylic resin, which is compounded by acrylic resin, modified inorganic particles, halogen-free weather-resistant epoxy acrylic resin and other components. The modified inorganic particles are obtained by modifying the double bond of boron nitride with silane coupling agent and further polymerizing with acrylic monomer. The modified inorganic particles introduce organic polymer structure on the surface of boron nitride, enhance the affinity of inorganic particles and acrylic resin and other components, and help to avoid the problem of agglomeration of a large amount of fillers.

[0031] The halogen-free weather-resistant epoxy acrylic resin is obtained by polymerizing acrylic alkyl ester with different carbon chain lengths, glycidyl acrylate and styrene. It not only does not contain halogen elements which are harmful to health and environment, but also has active epoxy groups which can promote the adhesion of the ink. The resin also has long and short alkyl chains, so that the ink has both flexible and rigid segments, which improves the strength and toughness of the film after curing, and also enhances the protection effect of water, acidic and alkaline solutions.

[0032] And, the modified inorganic particles of the present application have a large number of active carboxyl groups, and after being mixed with components such as an acrylic resin and a halogen-free weather-resistant epoxy acrylic resin, the active carboxyl groups, epoxy groups and other groups can be crosslinked through chemical bonds, hydrogen bonds and other forms, thereby forming a good network crosslinking structure of the organic resin, inorganic filler and other components, and having a promoting effect on the comprehensive performance of the ink.

[0033] In addition, it is worth mentioning that the present application also uses inorganic salts (such as magnesium nitrate and calcium nitrate) as an auxiliary agent, and the metal ions can be chelated with functional groups such as carboxyl groups in the ink mixing system to play the function of a crosslinking agent, thereby further enhancing the bonding strength between different substances, making the film layer have a more sufficient crosslinking structure, and promoting the further improvement of product strength and chemical resistance, overcoming the problems in the prior art. DETAILED DESCRIPTION

[0034] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment methods appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0035] The words "preferred", "preferably", "more preferred", and the like in the present application refer to the embodiments of the present application which can provide certain beneficial effects in certain cases. However, other embodiments can also be preferred in the same or other cases. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not usable, nor is it intended to exclude other embodiments from the scope of the present application.

[0036] It should be understood that, except in any operating examples, or otherwise indicated, expressions of amount or all numbers in the specification and claims, such as, for example, amounts of ingredients, should be understood as being modified by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that can vary depending on the desired properties sought to be obtained by the present application.

[0037] The acrylic resin in the embodiments of the present application is Sartomer CN104 NS.

[0038] The polymerized monomer in the embodiments of the present application is methyl acrylate.

[0039] The photoinitiator in the embodiments of the present application is ITX and UVI-6976 in a mass ratio of 1:1.

[0040] The auxiliary agent 1 in the embodiment of the present application is pigment (titanium dioxide) and leveling agent (isopropyl alcohol) with a mass ratio of 4:1; the auxiliary agent 2 is leveling agent (isopropyl alcohol) and calcium nitrate aqueous solution (20wt%) with a mass ratio of 1:3.

[0041] The solvent in the embodiment of the present application is divalent acid ester.

[0042] The epoxy resin in the embodiment of the present application is E-12 bisphenol A epoxy resin.

[0043] The emulsifier in the embodiment of the present application is OP-10, purchased from Aldrich; the initiator is ammonium persulfate.

[0044] The "parts" in the embodiment of the present application all refer to mass parts.

[0045] Example 1

[0046] A halogen-free and weather-resistant epoxy-acrylic resin-based solder resist ink, comprising component A and component B,

[0047] The component A comprises the following components with mass parts as follows:

[0048]

[0049] The component B comprises the following components with mass parts as follows:

[0050]

[0051]

[0052] The preparation method of the above halogen-free and weather-resistant epoxy-acrylic resin-based solder resist ink, comprising the following steps:

[0053] S1, with water as a solvent, glycidyl methacrylate, methyl methacrylate, butyl methacrylate, dodecyl acrylate, styrene, and emulsifier are blended and stirred uniformly with a mass ratio of 0.8:10:25:5:5:0.9, then an initiator (10wt% of the emulsifier) is added, and the reaction is carried out at 75℃ under nitrogen protection for 8h, and after cooling, the solvent is removed to obtain a halogen-free and weather-resistant epoxy-acrylic resin;

[0054] S2, with ethanol and water as solvents with a volume ratio of 5:1, hexagonal boron nitride and KH-570 are added with a mass ratio of 1:2, and the reaction is carried out at 90℃ under oil bath reflux for 24h, and after filtration, washing and drying, a double bond modified boron nitride is obtained.

[0055] The double bond modified boron nitride, acrylic acid and initiator are mixed in a mass ratio of 1:2:0.06 with water as the solvent, and reacted at 80°C for 8h under nitrogen protection. After filtration, washing and drying, the modified inorganic particles are obtained;

[0056] S3, the acrylic resin, modified inorganic particles, polymerized monomers, photoinitiator, auxiliary agent 1 and solvent are mixed in the above mass fraction, stirred uniformly, the pH is adjusted to 6.5-7 with ammonia water, component A is obtained; the halogen-free resistant epoxy acrylic resin, epoxy resin, auxiliary agent 2 and solvent are mixed to obtain component B; then the component A and component B are mixed, stirred and dispersed uniformly, and then ground to a fineness of ≤20μm to obtain a halogen-free resistant epoxy acrylic resin-based solder resist ink.

[0057] Example 2

[0058] A halogen-free resistant epoxy acrylic resin-based solder resist ink, comprising component A and component B,

[0059] The component A comprises the following components in mass fraction:

[0060]

[0061] The component B comprises the following components in mass fraction:

[0062]

[0063] The preparation method of the above halogen-free resistant epoxy acrylic resin-based solder resist ink comprises the following steps:

[0064] S1, glycidyl methacrylate, methyl methacrylate, butyl methacrylate, dodecyl acrylate, styrene and emulsifier are blended and stirred uniformly in a mass ratio of 0.8:10:25:5:5:0.9, then initiator (10wt% of the emulsifier) is added, and the mixture is reacted at 75°C for 8h under nitrogen protection. After cooling, the solvent is removed to obtain a halogen-resistant epoxy acrylic resin;

[0065] S2, ethanol and water are used as solvents in a volume ratio of 5:1, hexagonal boron nitride and KH-570 are added in a mass ratio of 1:2, and the mixture is refluxed at 90°C for 24h. After filtration, washing and drying, the double bond modified boron nitride is obtained;

[0066] The double bond modified boron nitride, acrylic acid and initiator are mixed in a mass ratio of 1:2:0.06 with water as the solvent, and reacted at 80°C for 8h under nitrogen protection. After filtration, washing and drying, the modified inorganic particles are obtained;

[0067] S3, according to the above mass fraction, acrylic resin, modified inorganic particles, polymerized monomer, photoinitiator, auxiliary 1 and solvent are mixed, stirred uniformly, pH is adjusted to 6.5-7 with ammonia water, component A is obtained; halogen-free resistant epoxy acrylic resin, epoxy resin, auxiliary 2 and solvent are mixed, component B is obtained; then the component A and component B are mixed, stirred and dispersed uniformly, and then ground to a fineness of ≤20 μm, to obtain a halogen-free resistant epoxy acrylic resin-based solder resist ink.

[0068] Example 3

[0069] A halogen-free resistant epoxy acrylic resin-based solder resist ink, the halogen-free resistant epoxy acrylic resin-based solder resist ink comprising component A and component B,

[0070] The component A comprises the following components in mass fraction:

[0071]

[0072] The component B comprises the following components in mass fraction:

[0073]

[0074] The preparation method of the above halogen-free resistant epoxy acrylic resin-based solder resist ink comprises the following steps:

[0075] S1, with water as the solvent, glycidyl methacrylate, methyl methacrylate, butyl methacrylate, dodecyl acrylate, styrene and emulsifier are blended and stirred uniformly in a mass ratio of 0.8:10:25:5:5:0.9, then an initiator (10wt% of the emulsifier) is added, and the reaction is carried out at 75°C under nitrogen protection for 8h, after cooling, the solvent is removed, and a halogen-free resistant epoxy acrylic resin is obtained;

[0076] S2, with ethanol and water as the solvent in a volume ratio of 5:1, hexagonal boron nitride and KH-570 are added in a mass ratio of 1:2, and the reaction is carried out at 90°C under oil bath reflux for 24h, after filtration, washing and drying, a double bond modified boron nitride is obtained;

[0077] With water as the solvent, the double bond modified boron nitride, acrylic acid and initiator are mixed in a mass ratio of 1:2:0.06, and the reaction is carried out at 80°C under nitrogen protection for 8h, after filtration, washing and drying, a modified inorganic particle is obtained;

[0078] S3, acrylic resin, modified inorganic particles, polymerizable monomer, photoinitiator, additive 1 and solvent were mixed in the above quality parts, stirred uniformly, adjusted to pH 6.5-7 with ammonia water, to obtain component A; halogen-free resistant epoxy acrylate resin, epoxy resin, additive 2 and solvent were mixed to obtain component B; then the component A and component B were mixed, stirred and dispersed uniformly, and then ground to a fineness of ≤20μm, to obtain a halogen-free resistant epoxy acrylate resin-based solder resist ink.

[0079] Comparative Example 1

[0080] A halogen-free resistant epoxy acrylate resin-based solder resist ink, the difference between this comparative example and Example 1 is that additive 2 is replaced by isopropanol, and the amounts of other ingredients and the preparation method are the same as those of Example 1.

[0081] Comparative Example 2

[0082] A halogen-free resistant epoxy acrylate resin-based solder resist ink, based on the comparative example 1, step S2 only prepares double bond modified boron nitride, and step S3 uses the double bond modified boron nitride as the modified inorganic particles.

[0083] Test Example

[0084] The solder resist ink samples prepared in Examples 1-3 and Comparative Examples 1-2 were tested for performance.

[0085] The test method is as follows:

[0086] The solder resist inks prepared in the examples and comparative examples were respectively coated on the PCB board, and photocured for 1h (wavelength 395nm, intensity 25.0mW / cm 2 of ultraviolet light), and then heat cured at 150℃ for 1h to form a 0.7mm thick film.

[0087] Adhesion: a cross was drawn on the film with a needle point, then a glass paper adhesive tape was pasted on the scratch, and pulled, and the evaluation was made according to the following criteria:

[0088] Pass: not torn off;

[0089] Fail: a large amount of tearing off.

[0090] Bending resistance: 180° bending was performed with the solder resist ink film as the outer side, then the horizontal state was restored, a total of 5 times of bending was repeated, and the following criteria were used for evaluation:

[0091] Pass: no cracks on the film;

[0092] Fail: cracks on the film.

[0093] Water resistance: The PCB circuit board coated with solder resist ink was immersed in deionized water at 20℃, and after 120h, the state and adhesion of the coating film were evaluated, and the judgment criteria were as follows:

[0094] Pass: no change or slight change was found;

[0095] Fail: the coating film had swelling or swelling and peeling.

[0096] Acid resistance: The PCB circuit board coated with solder resist ink was immersed in a 10% sulfuric acid solution at 20℃, and after 3h, the state and adhesion of the coating film were evaluated, and the judgment criteria were as follows:

[0097] Pass: no change or slight change was found;

[0098] Fail: the coating film had swelling or swelling and peeling.

[0099] Heat resistance: The heat shock performance test was carried out according to the method in IPC-SM-840E, and the judgment criteria were as follows:

[0100] Pass: no bubble or cracking;

[0101] Fail: bubbles or cracking appeared.

[0102] The test results are shown in Table 1.

[0103] Table 1 Performance test results

[0104] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesion Pass Pass Pass Pass Fail Bending resistance Pass Pass Pass Pass Fail Water resistance Pass Pass Pass Fail Pass Acid resistance Pass Pass Pass Fail Pass Heat resistance Pass Pass Pass Pass Pass

[0105] From the above test results, it can be seen that the solder resist ink based on the halogen-free and chemical-resistant epoxy acrylate resin prepared in the embodiment has excellent adhesion, bending resistance, solvent resistance and other properties. In Comparative Example 1, no inorganic salt was added, so there were many hydrophilic carboxyl groups in the ink that could not be fully crosslinked, resulting in the problem of swelling and peeling of the ink film layer in the water and acid environment for a long time. In Comparative Example 2, the modified inorganic particles were replaced by double bond modified boron nitride based on Example 1. On the one hand, the content of active groups was reduced, resulting in reduced adhesion, and the solid particles were difficult to fully crosslink with the epoxy resin, and the bending resistance also decreased. On the other hand, the double bond modified boron nitride could react with the polymer monomer through the double bond and be introduced into the film system, avoiding the problem of excessive hydrophilicity caused by a large number of carboxyl groups in Comparative Example 1, and the water resistance and chemical resistance were improved. In summary, the solder resist ink based on the halogen-free and chemical-resistant epoxy acrylate resin of the present application has good comprehensive performance, solves the defects in the prior art, and has good application prospect.

[0106] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other embodiments without departing from the scope of the application. The embodiments are therefore to be seen as exemplary and in no way restrictive, the scope of the application being defined by the claims below rather than by the above description, and all variations falling within the meaning and range of equivalency of the essential characteristics of the claims are therefore intended to be embraced therein.

[0107] Furthermore, it should be understood that although the description is made according to embodiments, not every embodiment contains only one independent technical solution, and the description is made in this way only for the sake of clarity, and a person skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by a person skilled in the art.

Claims

1. A solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin, characterized in that, The halogen-free resistance epoxy acrylic resin-based solder resist ink comprises component A and component B, The component A comprises ingredients in mass fraction as follows: The component B comprises ingredients in mass fraction as follows: wherein, The modified inorganic particles are the product of the reaction of silane coupling agent, acrylic acid and hexagonal boron nitride.

2. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 1, characterized in that The halogen-free resistance epoxy acrylic resin is the product of the reaction of glycidyl acrylate, alkyl acrylate and styrene.

3. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 2, characterized in that The mass ratio of the glycidyl acrylate, alkyl acrylate and styrene is (0.1-2):(20-50):(3-8).

4. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 3, characterized in that The alkyl acrylate comprises methyl acrylate, butyl acrylate and dodecyl acrylate.

5. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 1, characterized in that The mass ratio of the acrylic acid and hexagonal boron nitride is (0.5-5):

1.

6. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 1, characterized in that The silane coupling agent is vinyl silane coupling agent.

7. The solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to claim 1, characterized in that The auxiliary agent comprises inorganic salt.

8. The method of preparing a solder resist ink based on a halogen-free, chemical resistant epoxy acrylate resin according to any one of claims 1 to 7, characterized in that The preparation method of the halogen-free resistance epoxy acrylic resin-based solder resist ink comprises the following steps: S1, blending, stirring glycidyl acrylate, alkyl acrylate, styrene and emulsifier, then adding initiator, heating reaction under inert gas protection to obtain halogen-free resistance epoxy acrylic resin; S2, mixing hexagonal boron nitride and silane coupling agent, heating reaction, then adding acrylic acid and initiator, heating reaction under inert gas protection to obtain modified inorganic particles; S3, mixing acrylic resin, modified inorganic particles, polymerization monomer, photoinitiator, auxiliary agent and solvent, stirring uniformly to obtain component A; mixing halogen-free resistance epoxy acrylic resin, epoxy resin, auxiliary agent and solvent to obtain component B; finally mixing the component A and component B, stirring and grinding to obtain halogen-free resistance epoxy acrylic resin-based solder resist ink.

9. The method for preparing the solder resist ink based on the halogen-free chemical-resistant epoxy acrylic resin according to claim 8, characterized in that: In step S1, the heating reaction temperature is 50-100℃.

10. The method for preparing the solder resist ink based on the halogen-free chemical-resistant epoxy acrylic resin according to claim 8, characterized in that: In step S2, the heating reaction temperature is 60-100℃.

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