A multi-purpose UV-LED light-curing high-hiding screen printing ink and preparation method thereof

Abstract

The present invention discloses a multi-purpose UV-LED light-curing high-hiding screen printing ink, including a varnish component and a color paste component; the varnish component is component A and / or component B; the color paste component is a color paste or a white color paste. The common UV-curing system inks on the market are of various types and different performances, and are all limited to a small application field and have poor applicability. In actual production, users have to purchase products of different types or characteristics to meet different needs, which brings great inventory pressure, and UV-curing products have a short shelf life, resulting in unnecessary waste of resources and environmental pressure. In order to solve the problems of the prior art, the present invention discloses a multi-purpose UV-LED light-curing high-hiding screen printing ink; specifically, the groundbreaking formula design and its unique application mode of the present invention well solve the above problems and provide users with a brand new application experience.

Description

Technical Field

[0001] The invention relates to the technical field of screen printing inks, and in particular to a multi-purpose UV-LED light-curing high-hiding screen printing ink. Background Art

[0002] At present, the inks that use UV light curing are mainly medium-high pressure UV mercury lamp curing and UV-LED lamp curing, and they all have a common feature: a single formula design, targeted for a certain type or a certain type of material, narrow applicability, generally only used in a certain field, to solve a specific problem or demand; from the dimension of a certain application industry, for example, a certain product technology can solve the application on plastic workpieces such as PC, ABS or PC / ABS, such as font printing on the surface of computer keyboards, LOGO printing on the surface of electrical plastic shells, etc., but the formula design of the product is fixed, and when printed on materials of other properties such as PET, PP or PMMA, the product design cannot meet the requirements and has no adhesion on such materials; or the characteristics of a certain product design are good adhesion and high hardness on PMMA materials, but the product cannot meet the application on PET film. In short, the existing ink formula design is single, the product performance characteristics are relatively fixed, and can only solve a specific demand, with poor adaptability and narrow application. Summary of the invention

[0003] In summary, the common UV curing system inks on the market are of various types, with different performances, and are limited to small application fields, with poor applicability. In actual production, users have to purchase products of different types or characteristics to meet different needs, which brings great inventory pressure, and UV light-curing products have a short shelf life, causing unnecessary waste of resources and environmental pressure. In order to solve the problems of the prior art, the present invention discloses a multi-purpose UV-LED light-curing high-hiding screen printing ink; specifically, the invention's pioneering formula design and its unique application mode well solve the above problems, while giving users a new application experience.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A multi-purpose UV-LED light-curing high-hiding screen printing ink comprises a varnish component and a color paste component; the varnish component is component A and / or component B; the color paste component is a color paste or a white paste.

[0006] The multi-purpose UV-LED light-curing high-hiding screen printing ink of the present invention consists of a varnish component and a color paste component; the varnish component is component A and / or component B; and the color paste component is a color paste or a white paste.

[0007] The components of component A are composed of the following parts by mass:

[0008]

[0009]

[0010] The components of component B are composed of the following parts by mass:

[0011]

[0012] The components of the color paste are composed of the following parts by weight:

[0013]

[0014] The components of the white color paste are composed of the following parts by weight:

[0015]

[0016] In the present invention, the raw materials of each component are mixed to obtain a complete component. The preparation method of each component of the multi-purpose UV-LED light-curable high-hiding screen printing ink of the present invention comprises a varnish component and a color paste component; the varnish component is component A and / or component B; and the color paste component is a color paste or a white paste.

[0017] The preparation method of the varnish component (component A, component B) comprises the following steps:

[0018] (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution;

[0019] (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry;

[0020] (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain component A or component B.

[0021] The preparation method of the color paste components (color color paste C1 component, white color paste C2 component) is as follows:

[0022] (1) adding a monomer into a mixing barrel; then sequentially adding a full acrylate prepolymer and a modified epoxy acrylate resin into the mixing barrel, and stirring to mix them evenly; then adding a dispersant, and stirring to mix evenly; then adding a pigment, and stirring; then adding a defoamer, and stirring to obtain a slurry;

[0023] (2) Grinding the slurry with a grinder; then filtering to obtain a C1 component (color paste) and a C2 component (white paste).

[0024] In the present invention, stirring, grinding and filtering are conventional techniques. For example, the stirring device in the step is specifically a disperser, and the rotation speed of the disperser is 800-1200r / min; the grinder is specifically a nano-bead grinder, and the grinding fineness is ≤1μm; the mesh number of the filter cloth for filtering is 300 meshes.

[0025] The multi-purpose UV-LED light-curing screen printing ink involved in the present invention has a wide range of applications and is suitable for a variety of commonly used substrates on the market. It can be used in the surface screen printing process of materials such as PC, PMMA, ABS, PC+ABS, PC+PMMA, PET, PP, PVC, etc. It has excellent adhesion and good light resistance. It can not only meet the application requirements of hard material surfaces to provide functional requirements such as hardness and wear resistance, but also can be realized in the field where flexible film sheets have stamping and stretching requirements, thereby achieving the effect of decoration and protection of materials.

[0026] The present invention uses a variety of UV resin oligomers and prepolymers as connecting materials, which are polymerized under light curing conditions to form high molecular polymers, exerting excellent physical properties and reactivity, having good adhesion to various plastic materials and PET and PI films, and having toughness, high hardness, wear resistance, solvent resistance, low shrinkage, good light resistance and good compatibility.

[0027] Preferably, the photoinitiator is one or more of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 184 (1-hydroxy-cyclohexyl-phenyl ketone), 819 (phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide), BASF Irgacure 784, BASF Irgacure 261, and ITX (2 (2, 4 isomer mixture)). The preferred photoinitiator or compound mixture has an absorption effect on ultraviolet light at a wavelength of 250-440nm, a wide absorption spectrum range, and multiple effective absorption peaks at 231nm, 258nm, 307nm, 370nm, 382nm, 400nm and 405nm. By using different photoinitiators in combination, some photoinitiators are excited by energy under the irradiation of LED ultraviolet lamps with a wavelength of 365nm or 395nm to generate high-energy free radicals. These high-energy free radicals directly initiate the polymerization reaction of UV resin on the one hand, and on the other hand, some high-energy free radicals further excite other synergistic photosensitizers to release more free radicals, which initiate further polymerization reactions, thereby promoting deep curing. (2,4,6-trimethylbenzoyl-diphenylphosphine oxide) is a highly efficient general-purpose UV photoinitiator with an effective absorption peak of 350-400nm and absorption to about 420nm. It is a highly efficient free radical (I) type photoinitiator with fast photocuring speed and excellent absorption performance. It is particularly suitable for curing white, colored systems and thick film layers. BASF Irgacure 261 is a new type of cationic photoinitiator in the form of yellow powder. It has strong absorption at far ultraviolet 240-250nm and near ultraviolet 390-400nm. The present invention innovatively applies it to the UV-LED photocuring system, with high UV light utilization rate, efficient polymerization initiation, and after the light stops, it can continue to initiate polymerization cross-linking reaction for post-curing; in particular, for the photocuring of colored coatings with a coating thickness of more than 4 microns, the coating is left standing in the dark for 12 hours after the UV radiation ends, and the relevant physical properties of the coating increase by 10%-20%. BASF Irgacure 784, also known as bis(1-(2,4-difluorophenyl)-3-pyrrolyl) titanocene, has a purity of >99%; the molar extinction coefficients at 365nm and 405nm are 2612 and 119700 L / (mol.cm), which are 5-10 times that of general photoinitiators, and have high ultraviolet light absorption rate; in the black system involved in the present invention, 1%-2% is added, and TPO and ITX are compounded at the same time. When the film thickness is 4 microns, the curing effect is best when the UV energy value is 400mj / cm2; (1-hydroxy-cyclohexyl-phenyl ketone), white crystalline powder, effective absorption peaks are 246nm and 278nm, it is a highly efficient, non-yellowing free radical (I) type solid photoinitiator, has good non-yellowing properties, and is particularly suitable for transparent varnish and white systems.It is best to use it with TPO in the surface curing system. In general transparent systems, the curing efficiency is best when the mass ratio is 2:1. Photoinitiator 819 (phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide) is a highly efficient photoinitiator with wavelength absorption peaks at 370nm and 405nm, and the maximum absorption wavelength can reach 450nm. It has higher initiation activity than TPO; the preferred 819 produced by IGM has an active ingredient > 98% and a lighter color. Adding 0.5%-1% to the dark system can effectively solve the problems of low film gloss and surface orange peel caused by the incoordination of surface drying and deep curing speed. Photoinitiator ITX (2 (2, 4 isomer mixture)) is a highly efficient free radical II type photoinitiator with an absorption wavelength of 258, 382nm. It is used in combination with tertiary amine enhanced resin for UV polymerization curing. Adding 2-4% to the color system has a more ideal curing effect.

[0028] Preferably, the co-initiator is ethyl p-dimethylaminobenzoate (EDB), a tertiary amine sensitizer, which absorbs at 228-308nm in the ultraviolet region and has no photocuring effect itself. It can be used together with a free radical photoinitiator to increase photosensitivity and is mainly used in combination with ITX for photocuring colored systems.

[0029] Preferably, the oxygen inhibitor is DOUBLEMER L234 from Doublebond Chemicals, which is a special UV-LED curing polymerization co-initiator that effectively reduces oxygen inhibition, promotes surface curing, and promotes curing efficiency under low energy conditions; adding 0.5%-1% to the formula increases the curing efficiency by more than 10%.

[0030] Preferably, the polyurethane modified acrylate 1 can be Double Bond Chemical 6915, Changxing Chemical DR-U052, with a viscosity of 18000-28000 cps at 25°C, both of which are 4-functionality aliphatic polyurethane acrylates, which are beneficial to reducing the viscosity of the formula, have high reactivity and high cross-linking density, and have excellent flexibility and good adhesion to plastic substrates such as PET / PI;

[0031] The polyurethane modified acrylate 2 can be Changxing Chemical DR-U591, Wuxing Material Technology LED9500, with a viscosity of 25000-50000cps at 25°C, and is a 6-10-functional high-functionality aliphatic polyurethane acrylate with high reactivity and high cross-linking density, high hardness, and toughness and wear resistance. The two resins with different characteristics are used as the main connecting materials, and are cured together with monomers and other acrylates to give the ink system basic physical properties, excellent wear resistance and flexibility, good hardness and chemical resistance, etc.

[0032] Preferably, the all-acrylate prepolymer is Double Bond Chemical 6MX75 and Changxing Chemical 6533B-40, which have a significant effect on reducing shrinkage and promoting and improving the adhesion of ink on plastic substrates.

[0033] Preferably, the modified epoxy acrylate resin is DOUBLEMER 176TF-5, which is a modified bisphenol A epoxy acrylate, with a functionality of 2, a viscosity of 45000-65000cps at 25°C, an elongation of 9.6%, and good flexibility; it has a fast curing speed and also promotes the adhesion of plastic substrates such as PET / PP / PE; its wettability effect on pigments is conducive to the wetting and coating of pigments and fillers by the main resin, so that the present invention has an unexpected covering effect even when the amount of pigment added is low; it takes into account the fluidity of the ink, improves the wetting ability of the ink on the substrate, and effectively avoids the occurrence of light leakage phenomena such as pinholes and sand holes. In the formula involved in the present invention, DOUBLEMER 176TF-5 is the main resin for preparing nano-color paste, combined with all-acrylic prepolymer, plus dispersant, pigment, and is dispersed by grinding to prepare nano-color paste.

[0034] Preferably, the monomer is one or more of HDDA (1,6-hexanediol diacrylate), IBOA (isobornyl acrylate), DPHA (dipentaerythritol hexaacrylate), TPGDA (tripropylene glycol diacrylate), and PET3A (pentaerythritol triacrylate), which can adjust the viscosity of the ink system to meet the needs of the printing process, and at the same time, when combined with the resin, can promote the adhesion of the ink system on the material, adjust the reaction speed, adjust the crosslinking density, etc.; for example, compatibility, dilutability, high reactivity, and high crosslinking density.

[0035] Preferably, the dispersant is one or more of BYK-110, BYK-163, BYK-168, and Lubrizol SOLSPERSE (TM) 20000; in the present invention, the dispersant is a high molecular weight block copolymer containing pigment affinity groups, which is beneficial to the dispersion of solid particles and can also prevent the sedimentation and agglomeration of solid particles; preferably, the defoamer is BYK-054, Huaxia HX-2085, and Maitu TSA-750S defoamer.

[0036] Preferably, the pigment is one or more of titanium dioxide, F3RK yellow light red, permanent red F5RK blue light red, Hansa yellow R, Hansa yellow H4G, permanent yellow, phthalocyanine blue BGS, ultramarine, quinacridone violet and carbon black; the titanium dioxide is specifically one or two of Chemours rutile titanium dioxide R706, R900, and Ishihara PFR209; wherein, Chemours rutile titanium dioxide R706 or R900 has extremely high gloss, extraordinary hiding power and tinting power and is easy to disperse, and is used for bright white system; Ishihara PFR209 is a medium-sized rutile titanium dioxide pigment made by vulcanization process and silicon-aluminum surface treatment, which is suitable for matte white system. The carbon black is specifically a medium-high pigment carbon black with a particle size of 20-40 nanometers, one or two of Mitsubishi MA285, Columbia ADITYA BIRLA Raven 1255 carbon black, and Cabot R400R, characterized by an oil absorption value of 60-100 (cm3 / 100g), a tinting strength of 110-150, and a pH value of 3-5;

[0037] The filler is specifically a mixture of one or more of light calcium carbonate (nanoscale), nano barium sulfate, lithopone, poly(tetrafluoro)ethylene wax, and PE wax; the nanoscale filler has good compatibility with the organic component and will not weaken the comprehensive performance of the paint film. The refraction of the filler can make the light source penetrate into the film layer, which plays a role in promoting curing. In addition, poly(tetrafluoro)ethylene wax, PE wax, etc. also play a role in blocking oxygen and inhibiting polymerization on the surface of the ink, promoting UV curing.

[0038] The thickener is specifically one or more of fumed silica, polyamide wax and organic bentonite, which is used to adjust the viscosity and printing adaptability of the ink system and assist the dispersion and storage stability of the pigment.

[0039] Another major technical feature of the multi-purpose UV-LED light-curing high-hiding screen printing ink involved in the present invention is that it adopts the LED cold light source curing method; on the one hand, the ultraviolet light emitted by the UV-LED light-curing equipment has a wavelength from 260nm to 410nm, but considering the curing efficiency and use cost, the commonly used lamp group generally selects 365±5nm and 395±5nm, with a single wavelength and a spectrum release concentrated in a narrow band. It belongs to a cold light source, and compared with the medium and high pressure mercury lamp, there is no heat radiation. During the ultraviolet radiation curing process, the surface temperature of the substrate generally rises by about 1-3 degrees, the surface temperature rise of the illuminated object is low, and the processed parts are not easy to deform, especially solving the long-standing thermal damage problem in the production of heat-sensitive materials such as optical communication and liquid crystal screens. At the same time, the multi-purpose UV-LED light-curing high-hiding screen printing ink involved in the present invention can be applied to some instruments, electronic communications, liquid crystal display screens and other fields in addition to the application of low value-added fields such as packaging materials, which greatly broadens the market application scenarios and is of great significance to the sustainable development of UV curing system inks and the further improvement of market share.

[0040] Compared with the prior art, the present invention provides a multi-purpose UV-LED light-curable high-hiding screen printing ink, which has the following beneficial effects:

[0041] 1. The ink prepared by the present invention adopts a unique formula design idea, has wide versatility, is suitable for the surface screen printing needs of various common materials on the market, has good adhesion, is tough, wear-resistant, light-resistant and chemical-resistant, and can be used alone or mixed with other components; the amount of component C added determines the color concentration and covering effect of the ink.

[0042] 2. The invention, with its groundbreaking formula design and unique application mode, achieves multi-purpose use and multi-function, which well solves the problems of traditional UV ink with single formula design, relatively fixed performance characteristics, only being able to meet a specific demand, poor adaptability, and narrow application. It avoids the customer's purchase of products of different types or characteristics to meet different needs, which brings great inventory pressure, and the UV light-curing products have a short shelf life, which easily causes unnecessary waste of resources and environmental pressure.

[0043] 3. The ink of the present invention has good adhesion and strong versatility, which solves the problem of adhesion of one ink on the surfaces of various materials and can be simultaneously applicable to the screen printing process requirements of materials such as PET, PVC, PC, PMMA, PP, ABS, PC+ABS, PC+PMMA, etc.

[0044] 4. The ink involved in the present invention has a rich color system, which can meet most color requirements and can be self-adjusted to meet the diverse and personalized color requirements of users; the color concentration is increased by 30%-40% compared with general light-curing products.

[0045] 5. The present invention adopts UV-LED cold light source curing, the surface temperature rise of the illuminated object is low, and the processed parts are not easy to deform. It is suitable for electronic equipment, LCD touch screens, instrument panels and other fields with light shielding requirements, and there is no need to worry about the heat damage caused by the traditional UV mercury lamp curing process.

[0046] 6. The preferred photoinitiator and formula design of the present invention, the efficient curing system, also have a good film-forming effect under the condition of low ultraviolet energy radiation, and are suitable for LED lamp curing with a wavelength of 365nm and 395nm. When the thickness of the printed film layer is less than 4 microns, the UV energy value of 250-300mj / cm2 can complete the curing; when the thickness of the printed film layer is 4-6 microns, the UV energy value of 400-450mj / cm2 can complete the curing; when the thickness of the printed film layer exceeds 8 microns, it can be printed twice, the first time the film thickness is 4-5 microns, the UV energy value of 400-450mj / cm2 completes the curing, and the second time the film thickness is 2-3 microns, the UV energy value of 400-450mj / cm2 completes the curing; the present invention has good recoatability, can realize multi-color overprinting, excellent curing effect, and good interlayer adhesion.

[0047] 7. The ink prepared by the present invention has good wettability to the substrate, good leveling, and high ink layer finish; after curing, the ink layer is resistant to solvent erosion, has good weather resistance, and does not turn yellow for a long time; the cured ink layer has excellent hiding power, wherein the OD value reaches 4 when the black film thickness is 4-5 microns; there are no undesirable phenomena such as orange peel and pinholes. The curing effect is good, the physical properties of the ink layer are excellent, alcohol resistance (500gf≥500 times, 99.5% ethanol), resistance to cosmetics test (500gf≥300 times, a certain brand of hand cream), wear resistance (512 rubber, 500gf≥300 times); good ductility, suitable for stretching process requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The effect of screen printing white ink on PC sheet (bright white) obtained in Example 1;

[0049] Figure 2 The effect of screen printing black ink on PC sheet (bluish glossy black) obtained in Example 2;

[0050] Figure 3 This is the effect of screen printing the blue ink on the PC sheet obtained in Example 3 (BGS Phthalocyanine Blue). DETAILED DESCRIPTION

[0051] The raw materials used in the present invention are all existing products, which are conventional raw materials in the field of inks. The specific preparation operation and testing method are conventional technologies, which meet the conventional requirements of inks. The grinder is specifically a nano-bead grinder, and the grinding fineness is required to be ≤1μm; the mesh number of the filter cloth is 300 meshes; the stirring device is specifically a disperser, and the rotation speed is 1000r / min; each mass portion is 1Kg.

[0052] The creativity of the present invention lies in providing a formula composed of resin, additives, pigments and fillers, which overall solves the problem of narrow applicability of existing inks. The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0053] Embodiment 1

[0054] A multi-purpose UV-LED light-curing high-hiding white screen printing ink, consisting of component A and component C2.

[0055] The monomers are a mixture of HDDA, IBOA, and PET3A in a weight ratio of 6:1:3;

[0056] The photoinitiator is a mixture of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 184 (1-hydroxy-cyclohexyl-phenyl ketone), and 819 (phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide), with a weight ratio of 6:3:0.3;

[0057] The co-initiator is ethyl p-dimethylaminobenzoate (EDB);

[0058] The oxygen inhibitor is DOUBLEMER L234 from Double Bond Chemicals;

[0059] The all-acrylate prepolymer is Double Bond Chemical 6MX75;

[0060] Polyurethane modified acrylate 1 is DR-U052 from Changxing Chemical, and polyurethane modified acrylate 2 is DR-U591 from Changxing Chemical;

[0061] The thickener is specifically fumed silica;

[0062] The defoaming agent is specifically HX-2085;

[0063] The filler is nano light calcium carbonate and poly(tetrafluoro)ethylene wax, with a weight ratio of 8:2;

[0064] The modified epoxy acrylate is DOUBLEMER 176TF-5;

[0065] The dispersant is BYK-110 from BYK Chemicals;

[0066] The pigment is titanium dioxide, specifically Chemours R706.

[0067] The components of component A are composed of the following parts by mass:

[0068]

[0069] The components of component C2 (white color paste) are composed of the following parts by weight:

[0070]

[0071] The preparation method of component A is as follows:

[0072] (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution;

[0073] (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry;

[0074] (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain the main varnish of component A.

[0075] The preparation method of the color paste component is as follows:

[0076] (1) adding a monomer into a mixing barrel; then sequentially adding a full acrylate prepolymer and a modified epoxy acrylate resin into the mixing barrel, and stirring to mix them evenly; then adding a dispersant, and stirring to mix evenly; then adding a pigment, and stirring; then adding a defoamer, and stirring to obtain a slurry;

[0077] (2) Grinding the slurry with a grinder; then filtering to obtain component C2 (white color paste).

[0078] A multi-purpose UV-LED light-curable high-hiding screen printing white ink is prepared by mixing component A and component C2 (white color paste). The weight ratio is: component A (main varnish): component C2 (white color paste) = 50:50. Stir evenly to obtain the finished white ink.

[0079] The ink of the present invention can be cured by using a 365nm or 395nm LED lamp without yellowing; the preferred polyurethane acrylate has low viscosity and high functionality, and is matched with a highly reactive monomer, so that the ink can be quickly cured; the full acrylate has the characteristics of low odor and low irritation, and has good wettability and low shrinkage, so it is used in color ink and matched with other components to improve the adhesion of the ink to the substrate; through dispersion and grinding, the above components are prepared into a fine and uniform ink dispersion, which gives it excellent printability, extremely high gloss, extraordinary hiding power and excellent whiteness.

[0080] Embodiment 2

[0081] The monomers are a mixture of HDDA, TPGDA, and PET3A in a weight ratio of 6:2:2;

[0082] The photoinitiator is a mixture of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), ITX (2 (2, 4 isomer mixture)), BASF Irgacure 784 (bis (1- (2,4-difluorophenyl) -3-pyrrolyl) titanocene), and BASF Irgacure 261, with a weight ratio of 4:2:2:2;

[0083] The co-initiator is ethyl p-dimethylaminobenzoate (EDB);

[0084] The oxygen inhibitor is DOUBLEMER L234 from Double Bond Chemicals;

[0085] The all-acrylate prepolymer is Changxing Chemical 6533B-40;

[0086] Polyurethane modified acrylate 1 is Double Bond Chemical 6915, and polyurethane modified acrylate 2 is Five Elements Material Technology LED9500;

[0087] The thickener is specifically fumed silica;

[0088] The defoaming agent is specifically Huaxia HX-2085;

[0089] The filler is specifically light calcium carbonate (nanoscale) and poly(tetrafluoro)ethylene wax, with a weight ratio of 8:2;

[0090] The modified epoxy acrylate is DOUBLEMER 176TF-5;

[0091] The dispersant is specifically Lubrizol SOLSPERSE(TM) 20000;

[0092] The pigment is carbon black, and specifically: ADITYA BIRLA Raven 1255 carbon black;

[0093] A multi-purpose UV-LED light-curable high-hiding screen printing ink black, which is made by mixing two components: component A (main varnish) and component C1 (color paste), calculated by weight: component A (main varnish) / component C1 (color paste) = 70 / 30, and the finished black ink can be obtained by stirring evenly;

[0094] The components of component A (main varnish) are composed of the following parts by weight:

[0095]

[0096]

[0097] Component C1 (color paste) is black, and its components are composed of the following parts by weight:

[0098]

[0099] The preparation method of component A is as follows:

[0100] (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution;

[0101] (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry;

[0102] (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain the main varnish of component A.

[0103] The preparation method of the color paste component is as follows:

[0104] (1) adding a monomer into a mixing barrel; then sequentially adding a full acrylate prepolymer and a modified epoxy acrylate resin into the mixing barrel, and stirring to mix them evenly; then adding a dispersant, and stirring to mix evenly; then adding a pigment, and stirring; then adding a defoamer, and stirring to obtain a slurry;

[0105] (2) Grinding the slurry with a grinder; and then filtering to obtain a C1 component (black color paste).

[0106] The invention has an absorption effect on ultraviolet light at a wavelength of 250-400nm, and the synergistic effect of the auxiliary initiator ethyl dimethylaminobenzoate (EDB) enables the ink prepared by the invention to meet the curing requirements of two specifications of LED lamps of 365nm or 395nm; the polyurethane acrylate used has low viscosity and high functionality, and is matched with a highly reactive monomer, so that the ink can be quickly cured; the full acrylate has the characteristics of low odor, low irritation, and low shrinkage, so it is used in color ink to improve the adhesion of the ink to the substrate; the modified epoxy acrylate has good pigment wettability and is finally obtained through dispersion and grinding to obtain a fine and uniform black slurry dispersion, which gives it excellent printability; this embodiment provides a new formula, and the prepared ink has extremely high gloss, extraordinary hiding power and excellent physical properties, alcohol resistance, abrasion resistance, and light resistance.

[0107] Embodiment 3

[0108] A multi-purpose UV-LED light-curing high-hiding screen printing ink blue is prepared by mixing component A (main varnish), component B (blending varnish) and component C1 (color system color paste) blue. The three components are calculated by weight: component A (main varnish) / component B (blending varnish) / component C1 (color system color paste) blue = 50 / 20 / 30. The finished blue ink can be obtained by evenly stirring.

[0109] The monomers are a mixture of HDDA, TPGDA, and PET3A in a weight ratio of 6:2:2;

[0110] The photoinitiator is a mixture of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), ITX (2 (2, 4 isomer mixture)), and BASF Irgacure 261,819 (phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide) in a weight ratio of 4:2:2:2;

[0111] The co-initiator is ethyl p-dimethylaminobenzoate (EDB);

[0112] The oxygen inhibitor is DOUBLEMER L234 from Double Bond Chemicals;

[0113] The all-acrylate prepolymer is Changxing Chemical 6533B-40;

[0114] Polyurethane modified acrylate 1 was Double Bond Chemical 6915, and polyurethane modified acrylate 2 was Changxing Chemical's DR-U591;

[0115] The thickener is specifically fumed silica;

[0116] The defoaming agent is specifically Momentive 750S defoaming agent;

[0117] The filler is specifically poly(tetrafluoro)ethylene wax;

[0118] The modified epoxy acrylate is DOUBLEMER 176TF-5;

[0119] The dispersant is specifically BYK-168;

[0120] The pigment is Clariant Pigment Phthalocyanine Blue BGS.

[0121] The components of component A (main varnish) are composed of the following parts by weight:

[0122]

[0123]

[0124] Component B (varnish preparation):

[0125]

[0126] Component C1 (color paste) is blue, and its components are composed of the following parts by weight:

[0127]

[0128] The preparation method of component A is as follows:

[0129] (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution;

[0130] (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry;

[0131] (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain the main varnish of component A.

[0132] The preparation method of component B is as follows:

[0133] (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution;

[0134] (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry;

[0135] (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain the B component varnish.

[0136] The preparation method of the blue color paste of component C1 (color color paste) is as follows:

[0137] (1) adding a monomer into a mixing barrel; then sequentially adding a full acrylate prepolymer and a modified epoxy acrylate resin into the mixing barrel, and stirring to mix them evenly; then adding a dispersant, and stirring to mix evenly; then adding a pigment, and stirring; then adding a defoamer, and stirring to obtain a slurry;

[0138] (2) Grinding the slurry with a grinder; and then filtering to obtain a C1 component (blue color paste).

[0139] The invention has an absorption effect on ultraviolet light at a wavelength of 250-400nm, and the synergistic effect of the auxiliary initiator ethyl dimethylaminobenzoate (EDB) enables the ink prepared by the invention to meet the requirements of LED lamp curing of two specifications of 365nm or 395nm; the polyurethane acrylate used has a low viscosity and high functionality, and is matched with a highly reactive monomer, so that the ink can be quickly cured; the full acrylate has the characteristics of low odor, low irritation, and low shrinkage, so it is used in color ink to improve the adhesion of the ink to the substrate; the modified epoxy acrylate has good pigment wettability and is finally obtained through dispersion and grinding. A fine and uniform blue slurry dispersion is given, which gives it excellent printability; in this group of embodiments, the use of a large proportion of high-functionality polyurethane acrylate in component B improves the crosslinking density and hardness of the ink, so that the film layer has excellent physical properties after light curing, and alcohol resistance, chemical resistance, and especially vibration wear resistance are greatly improved.

[0140] Performance Test:

[0141] The above UV-LED light-curable high-hiding screen printing ink was screen-printed on the surface of the substrate through a 300-mesh screen; then a UV-LED cold light source (wavelength 365nm, UV energy value 300-400mj / cm 2), radiation curing, and a high hiding UV resin film with a film thickness of 4-6 microns is obtained. The high hiding UV resin film has bright and rich colors, and the color concentration is 30%-40% higher than that of general UV inks; the black has high hiding power, and the OD (optical density) value reaches 4 when the film thickness is 4 to 6 microns; the white has glossy and matte types, good whiteness, L value greater than 89, and light fastness level 6-7; excellent film-forming property, no orange peel, pinholes and other undesirable phenomena; good curing effect, alcohol resistance (500gf≥500 times, 99.5% ethanol), cosmetics test resistance (500gf≥300 times, a certain brand of hand cream), wear resistance (512 rubber, 500gf≥300 times), good adhesion (3M tape, 5B); good toughness, bending resistance; good recoatability, multi-color overprinting, and good interlayer adhesion.

[0142] In the experiment, the substrates were 12.5 micron thick PC sheet, 35 micron raw PMMA sheet, and 4.5 micron transparent PET film material. The thickness of the prepared film layer was 5 microns; the curing conditions were UV-LED cold light source, wavelength 365nm, UV energy value 400mj / cm 2 . Figure 1 The effect of screen printing white ink on PC sheet (bright white) obtained in Example 1; Figure 2 The effect of screen printing black ink on PC sheet (bluish glossy black) obtained in Example 2; Figure 3 This is the effect of screen printing the blue ink on the PC sheet obtained in Example 3 (BGS Phthalocyanine Blue).

[0143] Table 1 Performance standard of a multi-purpose UV-LED light-curable high-hiding screen printing ink (taking black ink in Example 2 as an example)

[0144]

[0145]

[0146]

[0147] The competitor inks are the two best products of their kind on the market for single substrates. The values ​​in the table are the limits of competitor inks in wear resistance tests.

[0148] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0149] Existing UV curing system inks have several disadvantages:

[0150] ① UV light-curing inks prepared by existing technologies, medium- and high-pressure UV mercury lamp curing or UV-LED curing, all have a common feature: a single formula design, specifically applicable to a certain type or category of materials, with narrow applicability, can only be used in a certain field to solve a specific problem or demand;

[0151] ② Currently, there are many types of UV curing inks with different performances, and they are all limited to a small application field with poor applicability. In actual production, users have to purchase products of different types or characteristics to meet different needs, which puts great inventory pressure. In addition, UV light-curing products have a short shelf life, which leads to resource waste and environmental pressure;

[0152] ③ The traditional medium-pressure UV mercury lamp is also called medium- and high-pressure gas discharge lamp. It generates high-intensity ultraviolet light through the metal vapor in the UV lamp tube. The spectrum range is relatively wide. In addition to the ultraviolet light band, it also generates infrared bands. The surface of the irradiated UV material will be damaged by thermal radiation. At the same time, the temperature in the mercury lamp workshop will rise faster, and the working environment is relatively poor.

[0153] ④ Traditional medium-pressure mercury lamp-cured UV system inks cannot be used in electronic equipment, LCD screens, precision instruments and other fields due to their thermal damage. They are generally more used in decorative fields such as packaging materials. They have low added value and higher costs than solvent-based inks. The market's willingness to apply them is not strong, which is not conducive to the sustainable development of UV-curing system inks and the further increase of market share.

[0154] Ordinary UV-LED-cured UV system inks cannot overcome the oxygen inhibition effect of oxygen on the coating surface. Moreover, the energy output of each UV-LED lamp bead is currently 100-300mW, which is much lower than the ultraviolet light energy output of traditional UV light sources, resulting in low curing efficiency and poor deep curing effect. Therefore, the products involved cannot achieve good covering effect, which limits their application in large-area printing or when there are certain covering requirements, such as touch screen frames, 5G mobile phone back covers, etc.

[0155] Currently, there are many types of UV-LED-cured inks, but they are simple in design, single in function, and narrow in application. Most of them are used to print small fonts, lines, borders, and products with low hiding power requirements, such as translucent inks, varnishes, matte oils, etc.; the quality of colored inks, especially dark-colored inks with certain hiding power effects, is uneven and cannot meet market demand;

[0156] Common UV curing system inks have poor applicability. Generally, they have good adhesion on the surfaces of plastic materials such as PC, ABS, PC+ABS, but poor adhesion on the surfaces of some difficult-to-attach materials such as PET, PP, PMMA, PC+PMMA, etc. They can only solve the adhesion problems of transparent colors such as varnish and matte oil, while the adhesion problems of colored system, especially dark system inks, are not solved, so there is no complete color system to meet users' diverse and personalized needs for colors.

[0157] Purpose and technical effect of the present invention:

[0158] The introduction of several photocurable resin materials and monomers and the use of photoinitiators, co-initiators and oxygen inhibitors in the present invention effectively solve the oxygen inhibition effect of oxygen on the coating surface, which is difficult to overcome during UV-LED curing, thereby improving the photocuring efficiency and the curing effect; the appropriate preparation process and the optimization of pigments greatly improve the UV-LED photocuring efficiency and deep curing effect compared with general products, making it possible to prepare UV-LED photocuring system inks with high hiding power;

[0159] The more efficient UV-LED light curing efficiency makes the product involved in the present invention also suitable for the printing needs of larger areas and thicker film layers, and the higher hiding power effect and higher color concentration can meet the high-concentration color requirements of printed products; its color system is rich and can meet most color requirements, and can be self-adjusted to meet the diverse and personalized color requirements of users;

[0160] Higher hiding power, that is, higher shielding effect at lower film thickness, is suitable for electronic equipment, LCD touch screens, instrument panels and other fields with light shielding needs, and there is no need to worry about heat damage similar to traditional UV mercury lamp curing process.

[0161] The invention has a groundbreaking formula design and a unique application mode, which can achieve multiple uses and functions. It solves the problems that the traditional UV ink formula design is single, the performance characteristics are relatively fixed, and it can only meet a specific demand, with poor adaptability and narrow application. In order to meet different needs, the customer application end has to purchase products of different types or characteristics, which brings great inventory pressure. In addition, the shelf life of UV light-curing products is short, which can easily cause unnecessary waste of resources and environmental pressure.

[0162] The multi-purpose UV-LED light-curing screen printing ink involved in the present invention has a wide range of applications and is suitable for a variety of commonly used substrates on the market. It can be used in the surface screen printing process of materials such as PC, PMMA, ABS, PC+ABS, PC+PMMA, PET, PP, PVC, etc. It has excellent adhesion, good light resistance, and good chemical resistance. It can not only meet the application requirements of hard material surfaces to provide functional requirements such as hardness and wear resistance, but also can be realized in the field where flexible film sheets have stamping and stretching requirements, thereby achieving the effects of decoration and protection of materials.

Claims

1. A multi-purpose UV-LED light-curing high-hiding screen printing ink, consisting of component A and component C2; The components of component A are composed of the following parts by mass: The components of the white color paste of component C2 are composed of the following parts by weight: The monomer is a mixture of HDDA, IBOA, and PET3A in a weight ratio of 6:1:3; the photoinitiator is a mixture of TPO, 184, and 819 in a weight ratio of 6:3:0.3; The co-initiator is ethyl p-dimethylaminobenzoate; The oxygen inhibitor is DOUBLEMER L234 from Double Bond Chemicals; The all-acrylate prepolymer is Double Bond Chemical 6MX75; Polyurethane modified acrylate 1 is DR-U052 from Changxing Chemical, and polyurethane modified acrylate 2 is DR-U591 from Changxing Chemical; The thickener is fumed silica; The defoaming agent is HX-2085; The filler is nano light calcium carbonate and poly(tetrafluoro)ethylene wax, with a weight ratio of 8:2; The modified epoxy acrylate is DOUBLEMER 176TF-5; The dispersant is BYK-110 from BYK Chemicals; The pigment is titanium dioxide.

2. A multi-purpose UV-LED light-curing high-hiding screen printing ink, consisting of component A and component C1; The components of component A are composed of the following parts by mass: C1 component color paste, each component is composed of the following parts by weight: The monomers are a mixture of HDDA, TPGDA, and PET3A in a weight ratio of 6:2:2; the photoinitiators are a mixture of TPO, ITX, BASF Irgacure 784, and BASF Irgacure 261 in a weight ratio of 4:2:2:2; The co-initiator is ethyl p-dimethylaminobenzoate; The oxygen inhibitor is DOUBLEMER L234 from Double Bond Chemicals; The all-acrylate prepolymer is Changxing Chemical 6533B-40; Polyurethane modified acrylate 1 is Double Bond Chemical 6915, and polyurethane modified acrylate 2 is Five Elements Material Technology LED9500; The thickener is fumed silica; The defoaming agent is Huaxia HX-2085; The filler is nano-scale light calcium carbonate and poly(tetrafluoro)ethylene wax, with a weight ratio of 8:2; The modified epoxy acrylate is DOUBLEMER 176TF-5; The dispersant is Lubrizol SOLSPERSE20000; The pigment is carbon black.

3. The method for preparing the multi-purpose UV-LED light-curable high hiding screen printing ink according to claim 1 or 2, characterized in that: The raw materials of various components are mixed to obtain the multi-purpose UV-LED light-curable high-hiding screen printing ink.

4. The method for preparing the multi-purpose UV-LED light-curable high hiding screen printing ink according to claim 3, characterized in that: The preparation method of component A is as follows: (1) Adding monomers into a mixing barrel; then adding photoinitiator, stirring until completely dissolved without particles, filtering out impurities, and obtaining a mixed solution; (2) adding the all-acrylate prepolymer, polyurethane acrylate 1, and polyurethane acrylate 2 into a mixing barrel and stirring to mix them evenly; then adding a filler and stirring; then sequentially adding a thickener and a defoamer and stirring to obtain a slurry; (3) Grinding the slurry with a nano-grinder; then adding the mixed solution, the co-initiator, and the oxygen inhibitor and stirring evenly, and then filtering to obtain component A.

5. The method for preparing the multi-purpose UV-LED light-curable high hiding screen printing ink according to claim 3, characterized in that: The preparation method of the color paste component is as follows: (1) adding a monomer into a mixing barrel; then sequentially adding a full acrylate prepolymer and a modified epoxy acrylate into the mixing barrel, and stirring to mix them evenly; then adding a dispersant, and stirring to mix evenly; then adding a pigment, and stirring; then adding a defoamer, and stirring to obtain a slurry; (2) Grinding the slurry with a grinder; and then filtering to obtain a color paste component.

6. A high hiding coating obtained by curing the multi-purpose UV-LED light-curable high hiding screen printing ink according to claim 1 or 2.

7. Use of the multi-purpose UV-LED light-curable high hiding screen printing ink according to claim 1 or 2 as a multi-purpose UV-LED light-curable screen printing ink.

8. The use according to claim 7, characterized in that: The applied substrates include PC, PMMA, ABS, PET, PP, PVC and PC+ABS, PC+PMMA composite materials.

Images