Preparation method of high-sensitivity epoxy solder mask acrylic oligomer and photoresist or ink composition

Abstract

The present invention provides an epoxy solder resist acrylic acid oligomer for solder mask ink or photoresist with good resistance to gold immersion, tin immersion, and low dielectric constant, as well as a preparation method and a photoresist or ink adhesive composition. The epoxy solder resist acrylic acid oligomer provided by the present invention contains an epoxy group, a carboxyl group, and a double bond. The weight average molecular weight of the epoxy solder resist acrylic acid oligomer is 13000-30000, and the acid value of the epoxy solder resist acrylic acid oligomer is 4mgKOH / g-9mgKOH / g; the epoxy equivalent of the oxygen solder resist acrylic acid oligomer is 30000-100000. The epoxy solder resist acrylic acid oligomer provided by the present invention has the beneficial effects of high molecular weight, high sensitivity, high development tolerance, high toughness, scratch resistance, excellent resistance to gold immersion, tin immersion, low dielectric constant, etc.

Description

[0001] The invention is a divisional application of the Chinese invention patent named "Preparation method of high-sensitivity epoxy solder mask acrylic oligomer and photoresist or ink composition" with application number: 202111425540.0 and application date: 2021.11.26. Technical Field

[0002] The invention belongs to the technical field of PCBs, and particularly relates to a preparation method of a high-sensitivity epoxy solder resist acrylic oligomer for solder resist ink or photoresist, and a photoresist or ink composition. Background Art

[0003] Existing oligomer binders for PCB solder mask inks are primarily directly modified novolac epoxy acrylate resins or o-cresol epoxy acrylate resins, which exhibit certain photosensitivity, developability, and surface hardness. However, due to their high number of short chains, low molecular weight, and poor developability, resistance to gold and tin immersion, these oligomers fail to meet the various performance requirements of solder mask inks in the modern electronics industry. Rapid technological innovations in manufacturing processes in the modern electronics industry have placed increasing demands on oligomer binders for PCB solder mask inks: While maintaining developability, they should also achieve improved efficiency, a more environmentally friendly process, and a higher yield rate during PCB manufacturing. Therefore, the market is in urgent need of developing a solder mask photoresist that combines high developability, high molecular weight, high photosensitivity, high surface gloss, high toughness, excellent resistance to gold and tin immersion, and a low dielectric constant. Summary of the Invention

[0004] To address the shortcomings of existing oligomer binders for PCB solder mask inks, such as high development tolerance, high molecular weight, high photosensitivity, high surface gloss, high toughness, excellent resistance to gold and tin immersion, and low dielectric constant, the present invention provides a linking technology that allows photosensitive oligomers with different properties to be linked to the same photosensitive oligomer using different epoxy resin linkers. For example, monomers with excellent properties such as low water absorption, low dielectric constant, good flexibility, and high reflectivity can be prepared on the same oligomer with epoxy resin, phenolic hydroxyl resin, and acidic resin, thereby obtaining an oligomer with more comprehensive properties.

[0005] The present invention provides

[0006] The epoxy solder mask acrylic oligomer provided by the present invention has the beneficial effects of high molecular weight, high sensitivity, high development tolerance, high toughness, scratch resistance, excellent resistance to immersion gold and immersion tin, low dielectric constant and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The above and other purposes, features and advantages of the present invention will become more apparent through the accompanying drawings. The same reference numerals indicate the same parts throughout the drawings, and the drawings are not intentionally scaled to actual size, but are intended to illustrate the gist of the present invention.

[0008] Figure 1 This is the FTIR structural characterization diagram of the epoxy solder mask acrylic oligomer provided in Example 1 of the present invention.

[0009] Figure 2 This is the GPC spectrum of the epoxy solder mask acrylic oligomer provided in Example 1 of the present invention.

[0010] Figure 3 This is the FTIR structural characterization diagram of the epoxy solder mask acrylic oligomer provided in Comparative Example 1.

[0011] Figure 4 This is the GPC spectrum of the epoxy solder mask acrylic oligomer provided in Comparative Example 1.

[0012] Figure 5 This is the FTIR structural characterization diagram of the epoxy solder mask acrylic oligomer provided in Example 2 of the present invention.

[0013] Figure 6 This is the GPC spectrum of the epoxy solder mask acrylic oligomer provided in Example 2 of the present invention.

[0014] Figure 7 This is the FTIR structural characterization diagram of the epoxy solder mask acrylic oligomer provided for Comparative Example 2.

[0015] Figure 8 GPC spectrum of epoxy solder mask acrylic acid oligomer provided for comparative example 2

[0016] Figure 9 FTIR spectra of the epoxy solder mask acrylic oligomer provided in Example 1 of the present invention and Comparative Example 1.

[0017] Figure 10 FTIR spectra of epoxy solder mask acrylic oligomers provided in Example 2 of the present invention and Comparative Example 2. DETAILED DESCRIPTION

[0018] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings.

[0019] refer to Figure 1-10An embodiment of the present invention provides a highly sensitive epoxy solder resist acrylic oligomer for solder resist ink or photoresist. The epoxy solder resist acrylic oligomer contains an epoxy group, a carboxyl group, and a double bond. The weight average molecular weight of the epoxy solder resist acrylic oligomer is 13,000-30,000. The acid value of the epoxy solder resist acrylic oligomer for solder resist ink or photoresist is 40 mgKOH / g-90 mgKOH / g; the epoxy equivalent of the epoxy solder resist acrylic oligomer is 30,000-100,000.

[0020] The highly sensitive epoxy solder resist acrylic oligomer provided by the present invention contains epoxy groups, so that the material can have both rigidity and toughness, and can also achieve properties such as low hygroscopicity and low dielectric constant.

[0021] The high-sensitivity epoxy solder resist acrylic oligomer provided by the present invention has a large molecular weight and good gloss, development resistance, and acid and alkali resistance.

[0022] The highly sensitive epoxy solder mask acrylic oligomer provided by the present invention has a large molecular weight, high sensitivity, high development tolerance, and high toughness. The photoresist or solder mask ink prepared therefrom has excellent properties such as resistance to gold and tin precipitation, and low dielectric constant.

[0023] The epoxy solder resist acrylic acid oligomer provided by the present invention can be used to prepare solder resist ink or photoresist.

[0024] In a preferred embodiment, the raw material components of the epoxy solder resist acrylic oligomer include epoxy resin, acrylic acid and / or methacrylic acid, acid anhydride and glycidyl ester.

[0025] The present invention also provides a method for preparing a highly sensitive epoxy solder resist acrylic oligomer, comprising the following steps:

[0026] (1) By weight, 30-40 parts of solvent, 20-40 parts of epoxy resin, 2-5 parts of epoxy resin linker, and 0.01-0.1 parts of the first type of catalyst are reacted in a reactor at a temperature of 140°C-160°C for 4-8 hours. When the epoxy equivalent weight reaches the set value, the linked epoxy resin is obtained. In this step, the reaction time and the epoxy equivalent weight (EEW) after crosslinking are mainly controlled.

[0027] (2) Add 10-15 parts of acrylic acid and / or methacrylic acid, 0.5-1 parts of a polymerization inhibitor, and 0.1-0.5 parts of a second type catalyst to the linked epoxy resin obtained in step (1), and react at a temperature of 100° C. to 135° C. until the acid value reaches 5-8 mgKOH / g and the epoxy equivalent weight reaches 15,000-20,000, thereby obtaining a semi-finished epoxy acrylic oligomer containing double bonds. In this step, the progress of the reaction is mainly determined by the acid value (AV) and epoxy equivalent weight (EEW).

[0028] (3) Adding 10-15 parts of anhydride and 0.1-1 parts of a third catalyst to the semi-finished epoxy acrylate oligomer obtained in step (2), the reaction temperature is 80°C-100°C, the reaction time is 4-6 hours, and the epoxy acrylate oligomer containing carboxyl groups and double bonds is obtained by measuring the epoxy equivalent weight (EEW). This step is mainly determined by Fourier transform infrared (FTIR), epoxy equivalent weight (EEW), and acid value (AV).

[0029] (4) Adding 2-5 parts of glycidyl ester and 0.1-0.3 parts of a fourth catalyst to the epoxy acrylate oligomer containing carboxyl groups and double bonds obtained in step (3), the reaction temperature is 90°C-120°C, the reaction time is 4-6 hours, the acid value is 5-8 mgKOH / g, and the epoxy equivalent weight is measured to be 30,000-100,000, to obtain an epoxy solder mask acrylate oligomer containing carboxyl groups and more double bonds. In this step, the acid value (AV) and epoxy equivalent weight (EEW) are mainly used to determine the reaction endpoint.

[0030] The present invention realizes the preparation of highly sensitive epoxy solder mask acrylic oligomers through a specific formula and preparation method. The epoxy solder mask has a large molecular weight and contains a large number of double bonds. It can not only meet the requirements of PCB solder mask, but also has excellent properties such as resistance to gold and tin precipitation, and low dielectric constant.

[0031] In a preferred embodiment, the solvent in step (1) is one or more of dipropylene glycol dimethyl ether, propylene glycol methyl ether acetate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, ethylene glycol butyl ether acetate, 150# solvent and diethylene glycol ethyl ether acetate (DCAC).

[0032] In a preferred embodiment, epoxy resin comprises one or more of o-cresol novolac epoxy resin, phenol epoxy resin and bisphenol F type epoxy resin and dicyclopentadiene epoxy resin. In a further preferred embodiment, epoxy resin comprises at least 2 kinds of o-cresol novolac epoxy resin, phenol epoxy resin and bisphenol F type epoxy resin and dicyclopentadiene epoxy resin. In the present embodiment, by selecting different epoxy resins, because of its different softening points, different structures (both having rigid structure and having flexible structure) can make the epoxy solder mask acrylic oligomer of synthesis have rigidity and toughness simultaneously, and performances such as low hygroscopicity and low dielectric constant.

[0033] In a preferred embodiment, the first, second, third, and fourth catalysts are different catalysts. The present invention utilizes a different catalyst in each step. The goal is to precisely select the catalyst for each step so that each reaction meets the specified testing standards. This results in the synthesized epoxy solder mask acrylic oligomer having not only high molecular weight, high sensitivity, and excellent development latitude, but also excellent resistance to immersion gold, immersion tin, acids, bases, and chemical solvents.

[0034] In a preferred embodiment, the first type of catalyst is one or more of tetrabutylammonium chloride, tetraethylammonium bromide, benzyltriethylammonium chloride and triphenylethylphosphonium bromide;

[0035] In a preferred embodiment, the second type of catalyst is one or more of N,N-dimethylaniline, N,N-dimethylbenzylamine, triphenylphosphine and hexadecyltrimethylammonium bromide;

[0036] In a preferred embodiment, the third type of catalyst is one or more of chromium acetate, chromium butyrate, manganese acetate and germanium acetate;

[0037] In a preferred embodiment, the fourth type of catalyst is one or more of 1-methylpyridinium chloride, 1-butylpyridinium chloride, 1-ethylpyridinium chloride and dodecylpyridinium bromide.

[0038] In a preferred embodiment, the epoxy resin linker (epoxy crosslinker) is one or more of 2-hydroxymalonic acid, 2-hydroxysuccinic acid, 2-hydroxyglutaric acid, 2-hydroxyoctanedioic acid, 3-hydroxysebacate, 2,4-dimethylbisphenol A, and 3,5-dibromobisphenol A. Due to the crosslinking effect of the crosslinker, the molecular weight of the synthesized epoxy solder mask acrylic oligomer increases, and its gloss, development resistance, and acid and alkali resistance are all enhanced.

[0039] In a preferred embodiment, the polymerization inhibitor is one or more of cuprous chloride, hydroquinone, p-hydroxyanisole and 2,6-di-tert-butyl-p-cresol.

[0040] In a preferred embodiment, the acid anhydride is one or more of phthalic anhydride, maleic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride, which can achieve a homogeneous reaction, give the epoxy solder mask acrylic oligomer a reasonable acid value, achieve better developability, improve exposure sensitivity, gloss and other properties.

[0041] In a preferred embodiment, the sensitizer is one or more of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexyl acrylate, and allyl glycidyl ether (vinyl glycidyl ether). These can enhance the high photosensitivity, development resistance, and resistance to immersion gold and immersion tin of the epoxy solder mask acrylic oligomer.

[0042] The present invention also provides a photoresist or ink composition, which comprises, by weight, 15-30 parts of the high-sensitivity epoxy solder mask acrylic oligomer mentioned in any of the above embodiments; 0.5-8 parts of a photoinitiator; 10-30 parts of an organic solvent; 20-30 parts of a powder; 2-5 parts of a pigment; and 15-30 parts of a curing agent.

[0043] The present invention will now be further described with reference to implementation cases.

[0044] The formulas of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 are shown in Table 1.

[0045] Table 1

[0046]

[0047]

[0048] Among them, the solvent DCAC is diethylene glycol ethyl ether acetate;

[0049] The above formula was prepared according to the following preparation method to obtain epoxy solder mask acrylic oligomers.

[0050] (1) According to the formulation in Table 1, a solvent, epoxy resin, epoxy resin crosslinker, and a first-class catalyst were reacted in a reactor at a temperature of 150°C-155°C for 5-7 hours. When the epoxy equivalent weight (EEW) was measured to be 300-400, a chain-extended epoxy resin was obtained. In this step, the reaction time and the epoxy equivalent weight (EEW) after crosslinking were mainly controlled.

[0051] (2) Adding acrylic acid and / or methacrylic acid, a polymerization inhibitor, and a second catalyst to the linked epoxy resin obtained in step (1) at a reaction temperature of 105° C. to 130° C. until the acid value reaches 5 mgKOH / g to 8 mgKOH / g and the epoxy equivalent weight reaches 15,000 to 20,000, thereby obtaining a semi-finished epoxy acrylic acid oligomer containing double bonds. In this step, the progress of the reaction is mainly determined by the acid value (AV) and epoxy equivalent weight (EEW).

[0052] (3) Acid anhydride and a third catalyst are added to the semi-finished epoxy acrylate oligomer obtained in step (2), and the reaction temperature is 85°C-120°C for 4-6 hours to obtain an epoxy acrylate oligomer containing carboxyl groups and double bonds. This step is mainly determined by Fourier transform infrared (FTIR), epoxy equivalent weight (EEW), and acid value (AV).

[0053] (4) Glycidyl ester and a fourth catalyst are added to the epoxy acrylate oligomer containing carboxyl groups and double bonds obtained in step (3). The reaction temperature is 95° C. to 115° C., the reaction time is 4 to 6 hours, and the acid value is 5 to 8 mgKOH / g. When the epoxy equivalent weight is measured to be 30,000 to 100,000, an epoxy solder mask acrylate oligomer containing carboxyl groups and more double bonds is obtained. In this step, the acid value (AV) and epoxy equivalent weight (EEW) are mainly used to determine the reaction endpoint.

[0054] The FTIR structural characterization of the high-sensitivity epoxy solder mask acrylic oligomer prepared in Example 1 is as follows: Figure 1 As shown, the GPC spectrum is as Figure 2 shown.

[0055] The FTIR structural characterization of the high-sensitivity epoxy solder mask acrylic oligomer prepared in Example 2 is as follows: Figure 3 As shown, the GPC spectrum is as Figure 4 shown.

[0056] The FTIR structural characterization of the epoxy solder mask acrylic oligomer prepared in Comparative Example 1 is as follows Figure 5 As shown, the GPC spectrum is as Figure 6 shown.

[0057] The FTIR structural characterization of the epoxy solder mask acrylic oligomer prepared in Comparative Example 2 is as follows: Figure 7 As shown, the GPC spectrum is as Figure 8 shown.

[0058] The epoxy solder resist acrylic acid oligomer prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 was used to prepare solder resist ink using the same formula and method. The solder resist ink formulation includes, by weight, 15-30 parts of epoxy solder resist acrylic acid oligomer; 0.5-8 parts of photoinitiator; 10-30 parts of organic solvent; 20-30 parts of powder; 2-5 parts of pigment; and 15-30 parts of curing agent.

[0059] The preparation method is:

[0060] 1. Add the ink formula into the dispersion barrel.

[0061] 2. Use a high-speed disperser at a speed of 600-1000 rpm for 30-60 minutes to disperse evenly.

[0062] 3. Grind with a three-roll mill 2-5 times or with a sand mill until the particle size is less than 20 microns.

[0063] 4. Add diluent to adjust the viscosity to 50-200P.

[0064] 5. Then filter with 150-300 mesh filter cloth.

[0065] 6. Weigh the weight and pack into packages of different specifications.

[0066] Following the synthesis of the epoxy acrylate oligomer and the PCB ink preparation process, the epoxy acrylate oligomers and inks prepared in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 were tested. Performance tests included molecular weight, resin viscosity, molecular weight distribution, color, appearance (IPC-SM-840E 3.3.1), sensitivity (STOUFFER 21), molecular weight (GPC), development latitude, surface hardness (GB / T9271-2008), gloss (GB / T-1766-1995), high temperature resistance (GB / T735-2009), acid resistance (IPC-SM-840E 3.6.1.2), flexibility, hygroscopicity, and immersion gold and immersion tin properties. The test structure is shown in Table 2.

[0067] Table 2

[0068]

[0069]

[0070] As can be seen from the data in Table 2, the products synthesized in Examples 1 and 2 exhibit higher molecular weights, better sensitivity and gloss, and higher surface hardness. Due to the high molecular weight, high photosensitivity, high toughness, and flexibility of the synthesized epoxy acrylic acid oligomers, solder mask inks produced using them as a binder exhibit excellent resistance to moisture, acid and alkali, solvent, and high temperatures, as well as resistance to gold and tin immersion. The epoxy solder mask acrylic acid oligomers prepared in Comparative Examples 1 and 2 exhibit inferior properties compared to those in Examples 1 and 2, resulting in significantly inferior inks with respect to acid and alkali resistance, solvent resistance, high temperature resistance, and resistance to gold immersion.

[0071] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "other embodiments" or "specific example" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0072] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An ink composition, characterized in that By weight, it includes 15-30 parts of high-sensitivity epoxy solder resist acrylic oligomer; 0.5-8 parts of photoinitiator; 10-30 parts of organic solvent; 20-30 parts of powder, 2-5 parts of pigment, and 15-30 parts of curing agent; The preparation method of the high-sensitivity epoxy solder resist acrylic oligomer comprises the following steps: (1) reacting the solvent, epoxy resin, epoxy resin linker and the first type of catalyst in a reactor at a temperature of 140°C-160°C for 4-8 hours to obtain a linked epoxy resin; (2) adding acrylic acid or methacrylic acid, a polymerization inhibitor, and a second type of catalyst to the linked epoxy resin, reacting at a temperature of 100° C. to 135° C. until the acid value reaches 5 to 8 mgKOH / g, thereby obtaining a semi-finished epoxy acrylic acid oligomer containing double bonds; (3) adding anhydride and a third type of catalyst to the semi-finished epoxy acrylic acid oligomer at a reaction temperature of 80° C. to 100° C. for 4 to 6 hours to obtain an epoxy acrylic acid oligomer containing a carboxyl group and a double bond; (4) adding a sensitizer and a fourth type of catalyst to the epoxy acrylic oligomer containing a carboxyl group and a double bond, with the reaction temperature being 90° C. to 120° C. and the reaction time being 4 to 6 hours to obtain a highly sensitive epoxy solder resist acrylic oligomer; The high-sensitivity epoxy solder resist acrylic oligomer contains a hydroxyl group, a carboxyl group, and a double bond. The weight average molecular weight of the high-sensitivity epoxy solder resist acrylic oligomer is 13,000-30,000. The acid value of the high-sensitivity epoxy solder resist acrylic oligomer is 40 mgKOH / g-90 mgKOH / g. The epoxy equivalent of the high-sensitivity epoxy solder resist acrylic oligomer is 30,000-100,000. The first type of catalyst, the second type of catalyst, the third type of catalyst and the fourth type of catalyst are different catalysts; The first type of catalyst is one or more of tetrabutylammonium chloride, tetraethylammonium bromide, benzyltriethylammonium chloride and triphenylethylphosphonium bromide; The second type of catalyst is one or more of N,N-dimethylaniline, N,N-dimethylbenzylamine, triphenylphosphine and hexadecyltrimethylammonium bromide; The third type of catalyst is one or more of chromium acetate, chromium butyrate, manganese acetate and germanium acetate; The fourth type of catalyst is one or more of methylpyridinium chloride, ethylpyridinium chloride, butylpyridinium chloride and dodecylpyridinium bromide; The epoxy resin linker is one or more of 2-hydroxymalonic acid, 2-hydroxysuccinic acid, 2-hydroxyglutaric acid, 2-hydroxyoctanedioic acid, and 3-hydroxysebacic acid; The sensitizer is vinyl glycidyl ether.

2. The ink composition according to claim 1, wherein The solvent in step (1) is one or more of dipropylene glycol dimethyl ether, propylene glycol methyl ether acetate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, ethylene glycol butyl ether acetate, 150# solvent and diethylene glycol ethyl ether acetate.

3. The ink composition according to claim 1, wherein The epoxy resin includes one or more of o-cresol epoxy resin, phenol epoxy resin, bisphenol F epoxy resin and dicyclopentadiene epoxy resin.

4. The ink composition according to claim 1, wherein The polymerization inhibitor is one or more of cuprous chloride, hydroquinone, p-hydroxyanisole and 2,6-di-tert-butyl-p-cresol.

5. The ink composition according to claim 1, wherein The acid anhydride is one or more of phthalic anhydride, maleic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, succinic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride.

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