Deep ultraviolet ink and preparation method thereof

Abstract

The invention relates to the technical field of ink, and discloses deep ultraviolet ink and a preparation method thereof, the deep ultraviolet ink comprises the following components by mass: 30-60 parts of resin, 20-45 parts of a photocurable monomer, 0.5-8 parts of a deep ultraviolet light initiator, 0.1-5 parts of an auxiliary agent, and 20-25 parts of a solvent. Through matching of a deep ultraviolet light initiator with a specific structure and a deep ultraviolet light source, rapid curing response of the ink is realized, and the problem of low curing speed caused by low initiation efficiency of traditional ultraviolet ink is solved. And a cured film with high crosslinking density is formed under the synergistic effect of the resin and the photocurable monomer, so that the hardness and adhesive force of a coating are remarkably improved, and the defect of the traditional ink on the bonding strength of a base material is overcome. The scientific ratio of the auxiliary agent to the solvent ensures the storage stability and leveling property of the ink, solves the problems of component separation and precipitation, and realizes uniform deep curing through the penetrability advantage of deep ultraviolet light.

Description

Technical Field

[0001] The present invention relates to the technical field of inks, and in particular to a deep ultraviolet ink and a preparation method thereof. Background Art

[0002] Ultraviolet ink technology is widely used in printing and electronics manufacturing. However, as the industry develops, the market has placed more stringent requirements on ink performance. As an emerging type of ink, deep ultraviolet ink faces technical bottlenecks that need to be overcome.

[0003] Traditional UV inks are typically cured using light sources in the 300-400nm wavelength range. Their photoinitiators have relatively low initiation efficiency in this wavelength range, resulting in slow curing speeds, making them unable to meet the fast-paced demands of high-speed printing and large-scale industrial production. For printing fine patterns, these inks are prone to blurring and unclear edges after curing, resulting in poor print quality. In electronic device manufacturing, the bond strength between traditional UV inks and substrates is less than ideal, resulting in poor adhesion, which significantly reduces the stability and reliability of electronic devices. Furthermore, traditional UV inks have poor adaptability to the wide variety of substrate materials, making it impossible to achieve uniform curing and stable adhesion on a variety of substrates.

[0004] At the same time, existing deep UV inks suffer from insufficient component stability. During storage and use, the components in the ink are prone to separation and precipitation, affecting the consistency and service life of the ink. In terms of curing depth, traditional inks have difficulty achieving deep curing. Especially for thicker ink coatings, the surface layer cures well but the interior cures insufficiently. This not only affects the overall performance of the ink, but also limits its use in some special applications, such as thick ink layer printing or three-dimensional structure manufacturing.

[0005] In view of the above problems, there is an urgent need to develop a new type of deep UV ink that can improve photoinitiation efficiency, achieve rapid curing, high-precision pattern printing, enhance adhesion to various substrates, and at the same time ensure comprehensive performance such as component stability and good curing depth, so as to promote the further development of related industries. Summary of the Invention

[0006] The purpose of the present invention is to provide a deep ultraviolet ink with fast curing speed, good curing depth and strong adhesion to substrates to address the problems existing in the prior art, so as to improve the printing quality and the reliability of electronic device manufacturing.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a deep ultraviolet ink, comprising the following components by weight: 30-60 parts of resin, 20-45 parts of photocurable monomer, 0.5-8 parts of deep ultraviolet photoinitiator, 0.1-5 parts of auxiliary agent, and 20-25 parts of solvent; The deep ultraviolet photoinitiator is a compound having a structure shown in Formula 1; Formula 1; The R1 is selected from the group consisting of: methyl, ethyl, propyl, tert-butyl, and phenyl.

[0008] Furthermore, the resin is selected from: acrylate hybrid resin; the acrylate hybrid resin is selected from: sartomer CN1073.

[0009] Furthermore, the photocurable monomer is selected from at least one of 1,6-hexanediol diacrylate, tetramethylene acrylate, and tripropylene glycol diacrylate.

[0010] Furthermore, the deep ultraviolet photoinitiator is selected from at least one of the compounds shown in the following structures: .

[0011] Furthermore, the auxiliary agent is selected from: acrylic ester leveling agent.

[0012] Furthermore, the solvent is selected from at least one of propylene glycol monomethyl ether, diethylene glycol butyl ether acetate, and propylene glycol monomethyl ether acetate.

[0013] A method for preparing deep ultraviolet ink comprises the following steps: S1. The resin, the photocurable monomer and 1 / 2 of the solvent were added to a stirred tank, and stirred under inert gas at 45-55 ° C to obtain a premix; S2. The deep ultraviolet photoinitiator, the additive and 1 / 2 of the solvent are added to the premix, and stirring is continued at 35-45 ° C until the deep ultraviolet photoinitiator is completely dissolved to obtain a mixture A; S3. Transfer the mixture A to a grinding device for grinding, controlling the grinding fineness to be ≤5 μm; after the grinding is completed, remove large particle impurities to obtain the deep ultraviolet ink.

[0014] Furthermore, the stirring speed is 400-800 rpm, and the stirring time is 30-90 minutes.

[0015] Furthermore, the grinding equipment is a three-roller grinder, a sand mill or a basket grinder.

[0016] A deep ultraviolet ink is used in the field of patterned curing or imaging using a light source in the 200-300nm wavelength band.

[0017] The deep ultraviolet photoinitiator described in the present invention has strong absorption in the deep ultraviolet region of 200-300nm, matches the deep ultraviolet light source, and solves the problem of low efficiency of traditional initiators in this band. The carbon-centered free radicals and oxygen free radicals generated by photolysis are highly active, can quickly initiate polymerization reactions, and significantly increase the curing speed. Deep ultraviolet light has relatively strong penetrability (compared to longer wavelengths), and combined with highly active initiators, it helps to achieve better curing depth and reduce the phenomenon of surface curing and internal non-curing. The photolysis products of oxime ester initiators are relatively small molecules, and are usually less prone to yellowing than some traditional initiators, which is conducive to obtaining higher quality cured films. The deep ultraviolet photoinitiator described in the present invention is specially designed for the deep ultraviolet band, which solves the problem of insufficient efficiency of traditional 300-400nm band initiators and makes full use of the energy of the deep ultraviolet light source.

[0018] The synergy of the resin and photocurable monomer described in the present invention solves the problems of insufficient curing depth, low pattern accuracy, poor adhesion, and poor adaptability to different substrates. The resin (Sartomer CN1073) combines the rapid reaction characteristics of acrylates with the excellent adhesion, toughness and adaptability to a variety of substrates brought by the hybrid structure, providing the main structure for the ink; the photocurable monomer rapidly undergoes free radical polymerization under the action of the highly active free radicals generated by the deep ultraviolet initiator to form a cross-linked network; reduces the viscosity of the system, improves leveling, and helps to form high-precision patterns; cooperates with the resin to quickly form a dense cross-linked network to ensure rapid curing; highly cross-linked, improves the hardness, chemical resistance and adhesion of the cured film; the choice of photocurable monomer affects flexibility, and cooperates with the resin to optimize the coating performance to adapt to different substrates; the highly active free radicals generated by the deep ultraviolet photoinitiator can efficiently attack the double bonds in the resin and monomer, overcoming the challenges that may be brought about by the relatively short wavelength of deep ultraviolet light penetration (compared to >300nm light), combined with high initiation efficiency, to jointly promote deep curing.

[0019] The additive described in this invention addresses the issues of poor leveling, which impacts pattern accuracy, and insufficient component stability. The acrylic leveling agent reduces ink surface tension, improves wettability and leveling on the substrate, reduces defects such as craters and orange peel, and ensures a uniform and smooth coating, which is crucial for achieving high-precision pattern printing. Its acrylic structure allows it to participate in the final curing process, preventing migration.

[0020] The solvent described in the present invention has suitable volatility and solvency, effectively dissolving components such as resins and monomers, ensuring uniformity and stability of the ink during storage and printing, and reducing precipitation and separation. It also adjusts ink viscosity for adaptability to various printing processes. It evaporates fully during the subsequent curing process, without affecting the properties of the final cured film.

[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly improve curing efficiency: By matching a deep ultraviolet photoinitiator with a specific structure and a deep ultraviolet light source, the ink achieves a rapid curing response, solving the problem of slow curing speed caused by low initiation efficiency of traditional UV inks.

[0022] 2. Enhance the mechanical properties of the coating: The synergistic effect of the resin and the photocurable monomer forms a cured film with a high cross-linking density, which significantly improves the hardness and adhesion of the coating, overcoming the defects of traditional inks in substrate bonding strength.

[0023] 3. Optimize component stability and applicability: The scientific ratio of additives and solvents ensures the storage stability and leveling of the ink, solves the problems of component separation and precipitation, and achieves uniform deep-layer curing through the penetrating advantage of deep ultraviolet light. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The deep ultraviolet light initiator 1 of the present invention 1 HNMR spectrum.

[0025] Figure 2 This is the UV absorption diagram of the deep UV photoinitiator 1 described in the present invention. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Synthesis example one Synthesis of deep ultraviolet photoinitiator 1: ; The first step: Under a nitrogen atmosphere, 20 g of raw material 1, 13.55 g of raw material 2, 12.58 g of anhydrous potassium carbonate and 200 g of a mixed solution of toluene, ethanol and water (volume ratio 2: 1: 1) were added to the reaction system in sequence, stirred evenly, and nitrogen was replaced twice. Under nitrogen protection, 1.58 g of tetrakis(triphenylphosphine)palladium was added to the reaction system, and nitrogen was replaced twice again. The reaction was heated to 95 ° C and refluxed for 10 hours. The heating was turned off, cooled to room temperature, and allowed to stand for separation. The aqueous phase was extracted twice with ethyl acetate, and the organic phases were combined. The organic phases were dried over anhydrous magnesium sulfate, filtered, and dried by column chromatography. A mixture of petroleum ether and ethyl acetate was used as an eluent and dried to obtain 20.59 g of intermediate 1.

[0028] Step 2: Under a nitrogen atmosphere, 20.59 g of intermediate 1, 3.45 g of raw material 3 and 200 g of dichloromethane were added to the reaction system in sequence, the system temperature was lowered to -20 ° C with dry ice, and 5.55 g of triethylamine was slowly added dropwise at a temperature not exceeding 0 ° C. The reaction was allowed to proceed at room temperature for 6 hours. After the reaction was complete, 500 ml of water at 0 ° C was slowly added dropwise, stirred for 1 hour, and allowed to stand for stratification. The organic phase was retained. The pH of the organic phase was adjusted to neutral with 0.1 mol / L dilute hydrochloric acid, washed with water once, and the organic phase was retained. Anhydrous magnesium sulfate was added to the organic phase for drying, filtration, spin-drying, column chromatography, and a mixture of petroleum ether and ethyl acetate was used as an eluent. Spin-drying gave 18.20 g of intermediate 2.

[0029] Step 3: Under a nitrogen atmosphere, 18.20 g of Intermediate 2, 2.09 g of hydroxylamine hydrochloride, 3.70 g of sodium acetate, and 200 g of tetrahydrofuran were added to the reaction system in sequence. The mixture was reacted at 70°C for 6 hours. After the reaction was complete, the reaction solution was added to 1000 ml of water, kept at 0°C overnight, and filtered to obtain a powdery solid. The powdery solid was dissolved in 100 ml of ethyl acetate, dried over anhydrous magnesium sulfate, filtered, and dried by spin drying. The mixture was then chromatographed on a silica gel column using a mixture of petroleum ether and ethyl acetate as the eluent, and dried by spin drying to obtain 15.97 g of Intermediate 3.

[0030] Step 4: Under a nitrogen atmosphere, 15.97 g of intermediate 3, 2.43 g of raw material 4 and 200 g of dichloromethane were added to the reaction system in sequence, the system temperature was lowered to -20 ° C with dry ice, and 5.22 g of triethylamine was slowly added dropwise at a temperature not exceeding 0 ° C. The reaction was allowed to proceed at room temperature for 6 hours. After the reaction was complete, 500 ml of water at 0 ° C was slowly added dropwise, stirred for 1 hour, and allowed to stand for stratification. The organic phase was retained. The pH of the organic phase was adjusted to neutral with 0.1 mol / L dilute hydrochloric acid, washed with water once, and the organic phase was retained. Anhydrous magnesium sulfate was added to the organic phase and dried, filtered, spin-dried, and column chromatography was performed using a mixture of petroleum ether and ethyl acetate as an eluent. Spin-dried to obtain 13.76 g of deep ultraviolet photoinitiator 1.

[0031] Structure identification: M / Z (MS+1) of intermediate 1: 563; M / Z (MS+1) of intermediate 2: 605; M / Z (MS+1) of intermediate 3: 620; M / Z (MS+1) of deep UV photoinitiator 1: 662; Deep UV Photoinitiator 1 1HNMR-CDCl3: δ8.59-8.46(m,2H),8.21-8.11(m,2H),8.11-7.94(m,3H),7.93-7.75(m ,3H),7.71-7.42(m,10H),7.35(dd,1H),7.28-7.07(m,4H),2.17(s,3H),2.08(s,3H).

[0032] Synthesis Examples 2 to 5 In Synthesis Examples 2 to 5, deep ultraviolet photoinitiator 2 to deep ultraviolet photoinitiator 5 were synthesized sequentially, referring to the synthesis method of Synthesis Example 1, replacing raw material 4 therein, and remaining the same as Synthesis Example 1. The specific structure of raw material 4, deep ultraviolet photoinitiator 2 to deep ultraviolet photoinitiator 5, and M / Z (MS+1) data are shown in Table 1.

[0033] Table 1. Structure of raw material 4, deep ultraviolet photoinitiator 2-deep ultraviolet photoinitiator 5, M / Z (MS+1) data involved in synthesis examples 2 to 5 Example 1 This embodiment provides a method for preparing deep ultraviolet ink, and the specific steps are as follows: The raw materials were weighed as follows: 45 parts of resin (Sartomer CN1073 acrylate hybrid resin), 30 parts of photocurable monomer (20 parts of 1,6-hexanediol diacrylate and 10 parts of tripropylene glycol diacrylate), 4 parts of deep ultraviolet photoinitiator (deep ultraviolet photoinitiator 1 synthesized in Synthesis Example 1), 0.5 parts of auxiliary agent (acrylate leveling agent), and 22 parts of solvent (11 parts of propylene glycol monomethyl ether and 11 parts of propylene glycol monomethyl ether acetate).

[0034] Preparation method: S1. Add the resin, photocurable monomer and 11 parts of solvent (propylene glycol monomethyl ether) to a stirred tank, replace the air with nitrogen three times, and under nitrogen protection, raise the temperature to 50°C and stir at 600 rpm for 60 minutes to form a premix.

[0035] S2. To the premix, a deep ultraviolet photoinitiator, an auxiliary agent, and the remaining 11 parts of solvent (propylene glycol monomethyl ether acetate) were added, the mixture was cooled to 40°C while maintaining a nitrogen atmosphere, and stirred at 600 rpm for 40 minutes until the initiator was completely dissolved to obtain a mixture A.

[0036] S3. Transfer mixture A to a three-roll mill and perform three-stage grinding: a first-stage roll gap of 50 μm, a roll speed ratio of 1:3:9, a second-stage roll gap of 20 μm, a roll speed ratio of 1:4:12, and a third-stage roll gap of 10 μm, a roll speed ratio of 1:5:15, to a final grind fineness of ≤4 μm. Grind to remove large particle impurities to obtain a deep ultraviolet ink.

[0037] Examples 2 to 5 A deep ultraviolet ink was prepared by referring to the preparation method of Example 1, except that the deep ultraviolet photoinitiator was replaced with deep ultraviolet photoinitiator 2 to deep ultraviolet photoinitiator 5 synthesized in Synthesis Examples 2 to 5 in sequence, and the rest remained the same as Example 1.

[0038] Comparative Example 1 A deep ultraviolet ink was prepared by referring to the preparation method of Example 1, except that the deep ultraviolet photoinitiator was not added, and the rest of the steps were the same as those of Example 1.

[0039] Comparative Example 2 A deep ultraviolet ink was prepared by referring to the preparation method of Example 1, except that the mass fraction of the photocurable monomer was changed to 5 parts, and the rest remained the same as in Example 1.

[0040] Comparative Example 3 A deep ultraviolet ink was prepared by referring to the preparation method of Example 1, except that the weight fraction of the auxiliary agent was changed to 10 parts, and the rest remained the same as Example 1.

[0041] Performance testing: 1. Determination of the maximum UV absorption peak of deep UV photoinitiator: The deep UV photoinitiator prepared by the present invention is prepared as 10 -5 The UV-visible absorption spectrum of propylene glycol methyl ether acetate (PMA) solution at 200-450 nm was tested to obtain its maximum absorption wavelength (λmax). The data are shown in Table 2. The UV spectrum of deep UV photoinitiator 1 at 200-450 nm is shown in Table 2. Figure 1 .

[0042] 2. Deep UV ink curing time: A deep UV ink prepared in the examples and comparative examples was evenly coated on a glass substrate using a 100 μm wire rod coater at a wavelength of 254 nm and a light intensity of 30 mW / cm 2 Expose to ultraviolet light, sprinkle small glass beads evenly at a height of 150 mm from the coating surface, and consider complete curing as the standard when there is no glass beads embedded in the coating surface and no adhesion marks. Record the time from the start of exposure to complete curing. The data are shown in Table 2.

[0043] 3. Test of deep ultraviolet ink hardness: A deep ultraviolet ink prepared in the examples and comparative examples was coated on an alumina plate (50×100×1 mm), with a wet film thickness of 20 μm. The plate was completely cured under a 254 nm light source. After curing, the sample was cured in a constant temperature and humidity chamber (23±2°C, 50±5% RH) for 24 h. A pencil was fixed to the hardness tester at a 45° angle, and a vertical load of 1 kg was applied. The test was started from 6 h, and the sample was pushed 3 mm at a speed of 0.5 mm / s. The highest pencil hardness value without scratches on the paint film was used as the measurement result. The data are shown in Table 2.

[0044] Table 2. Performance test data.

[0045] The deep UV photoinitiators used in the examples all exhibited strong absorption in the deep UV band (263-270 nm), demonstrating their effective compatibility with deep UV light sources. The examples using the ink formulations of the present invention all demonstrated significantly shortened cure times and higher pencil hardness, demonstrating the high efficiency of the deep UV initiators and the excellent mechanical properties achieved through the synergistic effect of the components. In contrast, Comparative Example 1 (no initiator) exhibited a complete loss of curing ability, Comparative Example 2 (insufficient monomer) experienced a significant decrease in cure speed and deterioration in hardness, and Comparative Example 3 (excessive additives) exhibited reduced curing efficiency and decreased hardness. These comparative results strongly demonstrate the necessity of each component in its specific ratio.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A deep ultraviolet ink, characterized in that: The invention comprises the following components in parts by weight: 30-60 parts of resin, 20-45 parts of photocurable monomer, 0.5-8 parts of deep ultraviolet light initiator, 0.1-5 parts of auxiliary agent, and 20-25 parts of solvent; The deep ultraviolet photoinitiator is a compound having a structure shown in Formula 1; Formula 1; The R1 is selected from the group consisting of: methyl, ethyl, propyl, tert-butyl, and phenyl.

2. The deep ultraviolet ink according to claim 1, characterized in that: The resin is selected from: acrylate hybrid resin; the acrylate hybrid resin is selected from: sartomer CN1073.

3. The deep ultraviolet ink according to claim 1, characterized in that: The photocurable monomer is selected from at least one of 1,6-hexanediol diacrylate, tetrahydrofuran acrylate, and tripropylene glycol diacrylate.

4. The deep ultraviolet ink according to claim 1, characterized in that: The deep ultraviolet photoinitiator is selected from at least one compound represented by the following structure: 。 5. The deep ultraviolet ink according to claim 1, characterized in that: The auxiliary agent is selected from: acrylic ester leveling agent.

6. The deep ultraviolet ink according to claim 1, characterized in that: The solvent is selected from at least one of propylene glycol monomethyl ether, diethylene glycol butyl ether acetate, and propylene glycol monomethyl ether acetate.

7. A method for preparing the deep ultraviolet ink according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. The resin, the photocurable monomer and 1 / 2 of the solvent were added to a stirred tank, and stirred under inert gas at 45-55 ° C to obtain a premix; S2. The deep ultraviolet photoinitiator, the additive and 1 / 2 of the solvent are added to the premix, and stirring is continued at 35-45 ° C until the deep ultraviolet photoinitiator is completely dissolved to obtain a mixture A; S3. The mixture A is transferred to a grinding device for grinding, and the grinding fineness is controlled to be ≤5μm; After the grinding is completed, large particle impurities are removed to obtain the deep ultraviolet ink.

8. The method for preparing deep ultraviolet ink according to claim 7, characterized in that: The stirring speed is 400-800 rpm, and the stirring time is 30-90 minutes.

9. The method for preparing deep ultraviolet ink according to claim 7, wherein: The grinding equipment is selected from three-roller grinder, sand mill or basket grinder.

10. Use of the deep ultraviolet ink according to any one of claims 1 to 6 in the field of patterned curing or imaging using a light source in the 200-300 nm wavelength range.

Images