High speed printing uv ink

Abstract

The present application provides a kind of high-speed printing UV ink, including photo-curable monomer, photo-initiator and resin, photo-curable monomer includes first photo-curable monomer and second photo-curable monomer, first photo-curable monomer is siloxane modified acrylate, the Tg of second photo-curable monomer is less than 0 DEG C, carbon chain length is greater than or equal to 5, the ratio of first photo-curable monomer and second photo-curable monomer is 3:7~5:8. The printing product obtained by printing using the ink of the present application has good curing effect and can be completely cured, and there is no color stacking behavior when rubbing.

Description

TECHNICAL FIELD

[0001] The application relates to the field of ink preparation, in particular to a high-speed printing UV ink. BACKGROUND

[0002] Single Pass inkjet printer is a kind of high-efficiency and high-precision inkjet printing equipment, which is characterized by high printing speed and high printing precision, and can realize rapid, efficient and high-quality production. Single Pass inkjet printer adopts advanced inkjet technology, and sprays ink on the printing material through a single nozzle to form the required pattern or text on the printing material. Since a single nozzle is used, Single Pass inkjet printer can pass the printing material once, without the need for line-by-line scanning like traditional inkjet printing, thereby greatly improving the printing speed and production efficiency. In addition, Single Pass inkjet printer also has high-precision printing effect, which can realize high-definition and high-resolution printing, so that the printed pattern or text is clearer and more delicate, meeting various high-quality production needs. Therefore, Single Pass inkjet printer is widely used in the fields of advertising, printing and packaging.

[0003] At present, the relatively mature nozzles used in such equipment are EPSON S3200 and Kyocera nozzles, and the representative equipment manufacturers are Printronix, Hattan and Founder. The imported ink manufacturers mainly include Sun and Oriental ink. Although the stability and effect of the ink are good, there are still defects in universality. The imported ink is mainly hard ink, which is easy to crack when printing soft film materials. Adjusting the ink to be flexible will cause uneven overlapping color problems. Moreover, due to the need to adjust the curing speed of the ink to be relatively fast, the sensitivity to natural light is improved, which can easily cause nozzle oblique spraying and clogging during continuous work. SUMMARY

[0004] The purpose of the present application is to provide a high-speed printing UV ink to solve the problems of existing high-speed printing ink, such as easy cracking and uneven overlapping color when printing film materials, and easy nozzle oblique spraying and clogging.

[0005] In order to achieve the above-mentioned purpose, the high-speed printing UV ink provided by the present application comprises a photocurable monomer, a photoinitiator and a resin, the photocurable monomer comprises a first photocurable monomer and a second photocurable monomer, the first photocurable monomer is a siloxane-modified acrylate, the second photocurable monomer has a Tg lower than 0 DEG C and a carbon chain length greater than or equal to 5, and the ratio of the first photocurable monomer to the second photocurable monomer is 3:7-5:8.

[0006] As can be seen from the above scheme, the addition of siloxane modified acrylate in the ink, the siloxane segment has flexibility, which can improve the flexibility of the ink after printing. The introduction of siloxane segment is beneficial to toughening material, improving thermal stability, water resistance and weather resistance. The siloxane segment also has variable performance, making the material more flexible. However, excessive use of siloxane chain will cause the collapse of microscale components, and further cause microcracks in the film formed by curing. The addition of the second photocurable monomer has good plasticizing effect, which increases the flexibility of the whole ink system. However, excessive use of the second photocurable monomer will cause entanglement of long chains, which is easy to stack, thereby causing the film forming performance to be poor. Adding the first photocurable monomer and the second photocurable monomer in a ratio of 3:7 to 5:8 can ensure good flexibility of the ink system and good film forming performance and uniform color stacking.

[0007] A further scheme is that the photoinitiator includes a first photoinitiator and a second photoinitiator, the first photoinitiator is an LED lamp long wavelength photoinitiator, and the second photoinitiator is a thioxanthone photoinitiator. The ratio of the first photoinitiator to the second photoinitiator is 8:3 to 7:2. The LED lamp long wavelength photoinitiator can initiate polymerization under long wavelength LED light source. The long wavelength is between 350 nm and 420 nm.

[0008] A further scheme is that the photoinitiator mainly provides free radicals for UV curing, and determines the curing degree of the UV cured film. By using two types of photoinitiators and adjusting the curing speed of the curable monomer to the best within the appropriate ratio, the curing speed is fast and the curing effect is good, and there is no problem of uneven color stacking, nor there is no problem of inclined spraying and clogging of the nozzle.

[0009] A further scheme is that the first photoinitiator is selected from at least one of diphenyl-(2,4,6-trimethylbenzoyl)-phosphine oxide, 1,5-di(thiophen-2-yl)pent-1,4-dien-3-one, 2,6-bis(thiophen-2-ylmethylene)cyclohexanone and 4,4-dimethyl-2,6-bis(thiophen-2-ylmethylene)cyclohexanone, and the second photoinitiator is selected from at least one of 2-isopropylthioxanthone and 2,4-diethylthioxanthone.

[0010] As can be seen from the above scheme, the use of the above first photoinitiator and second photoinitiator makes the first photocurable monomer and the second photocurable monomer used together, reduces the photosensitivity, controls the curing speed to be lower than 80 m / min, and further ensures the flexibility improvement without the problem of uneven color stacking.

[0011] A further scheme is that the second photocurable monomer is selected from at least one of lauryl acrylate and ethoxyethoxyethyl acrylate.

[0012] From the above scheme, it can be seen that the above compound is selected as the second light-curable monomer, which can improve the flexibility of the ink system while having good adhesion and environmental safety advantages.

[0013] Further, the resin is selected from at least one of polyurethane acrylate oligomer, epoxy acrylate oligomer, polyester acrylate oligomer.

[0014] From the above scheme, it can be seen that the above resin can improve the physical properties of the inkjet layer in various aspects, such as weather resistance, water resistance, chemical resistance, flexibility and ductility, and positively promote the curing speed of the entire system.

[0015] Further, the silicone-modified acrylate is prepared by reacting organosiloxane with acrylate monomers under the action of an acid catalyst, an emulsifier and an initiator.

[0016] From the above scheme, it can be seen that the silicone-modified acrylate prepared by the above preparation method has excellent weather resistance, water resistance, flexibility and adhesion, etc. At the same time, the preparation method is environmentally friendly and safe, which meets the development trend of modern industry.

[0017] Further, the high-speed printing UV ink includes 5% to 30% of color paste, 1% to 30% of the resin, 25% to 60% of the light-curable monomer, 2% to 10% of the photoinitiator, 1% to 2% of the light stabilizer, 0.5% to 1% of the polymerization inhibitor and 0% to 5% of the leveling agent.

[0018] Further, the color paste is selected from at least one of C.I. Pigment Blue, C.I. Pigment Cyan, C.I. Pigment Red, C.I. Pigment Yellow, C.I. Pigment White.

[0019] Further, the light stabilizer is selected from at least one of hydroxyphenyl triazine, hydroxyphenyl benzotriazole, benzophenone, oxanilide, cyanoacrylate, salicylate.

[0020] From the above scheme, it can be seen that the addition of the light stabilizer can better ensure the stability of the continuous operation of the ink.

[0021] Further, the polymerization inhibitor is 4-methoxyphenol.

[0022] From the above scheme, it can be seen that the above polymerization inhibitor is selected to ensure the storage stability of the UV color paste and the ink, and to avoid the crosslinking reaction caused by external conditions such as light, temperature, etc. affecting the use of the ink.

[0023] Further, the leveling agent is selected from at least one of BYK 333, BYK 3510, EFKA 3277.

[0024] From the above scheme, it can be seen that the above-mentioned leveling agent can play a role of leveling and wetting in the ink system, ensuring that the ink is quickly solidified, and at the same time, the leveling and wetting on the soft film substrate are quickly achieved, the final printing effect is ensured, and adverse phenomena such as white spots and easy peeling of the inkjet layer are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a picture of a label printing overprint test using the ink of Example 1.

[0026] Figure 2 is a picture of a label printing overprint test using the ink of Comparative Example 2.

[0027] The application will be further described below in conjunction with the drawings and examples. DETAILED DESCRIPTION

[0028] The application provides a high-speed printing UV ink, which comprises 1-30% of the resin, 25-60% of the photocurable monomer and 2-10% of the photoinitiator by mass percentage.

[0029] Preferably, the high-speed printing UV ink further comprises 5-30% of the color paste.

[0030] Preferably, the high-speed printing UV ink further comprises 1-2% of the light stabilizer.

[0031] Preferably, the high-speed printing UV ink further comprises 0.5-1% of the polymerization inhibitor.

[0032] Preferably, the high-speed printing UV ink further comprises 0-5% of the leveling agent.

[0033] The color paste is selected from at least one of C.I. Pigment Blue, C.I. Pigment Cyan, C.I. Pigment Red, C.I. Pigment Yellow and C.I. Pigment White.

[0034] The resin is selected from at least one of polyurethane acrylate oligomer, epoxy acrylate oligomer and polyester acrylate oligomer.

[0035] The photocurable monomer comprises a first photocurable monomer and a second photocurable monomer, wherein the first photocurable monomer is a siloxane-modified acrylate, and the second photocurable monomer has a Tg lower than 0℃ and a carbon chain length greater than or equal to 5. The first photocurable monomer is prepared by reacting an organosiloxane with an acrylate monomer under the action of an acid catalyst, an emulsifier and an initiator. Preferably, the second photocurable monomer is selected from at least one of lauryl acrylate and ethoxyethoxyethyl acrylate. The ratio of the first photocurable monomer to the second photocurable monomer is 3:7-5:8.

[0036] The photoinitiator comprises a first photoinitiator and a second photoinitiator, the first photoinitiator is an LED lamp long wavelength photoinitiator, the second photoinitiator is a thioxanthone photoinitiator, and the ratio of the first photoinitiator to the second photoinitiator is 8:3-7:2. Preferably, the first photoinitiator is selected from at least one of diphenyl-(2,4,6-trimethylbenzoyl)-phosphine oxide, 1,5-di(thiophen-2-yl)pent-1,4-diene-3-ketone, 2,6-bis(thiophen-2-ylmethyl)cyclohexanone and 4,4-dimethyl-2,6-bis(thiophen-2-ylmethyl)cyclohexanone, and the second photoinitiator is selected from at least one of 2-isopropylthioxanthone and 2,4-diethylthioxanthone.

[0037] The light stabilizer is selected from at least one of hydroxyphenyl triazine, hydroxyphenyl benzotriazole, benzophenone, oxanilide, cyanoacrylate, salicylate.

[0038] The polymerization inhibitor is 4-methoxyphenol.

[0039] The leveling agent is selected from at least one of BYK 333, BYK 3510 and EFKA 3277.

[0040] The preparation method of the high-speed printing ink provided by the present application is a method of preparing ink known to those skilled in the art.

[0041] The technical solutions of the present application are further illustrated by the following examples. In the following examples, the content is mass percentage unless otherwise specified.

[0042] The preparation method of the first light-curable monomer silicone-modified acrylate used in the following examples and comparative examples is as follows:

[0043] A four-necked flask equipped with a condenser, a stirrer, a dropping device and a thermometer was placed in a thermostatic water bath, 1.5 parts of sodium dodecyl benzene sulfonate, 1.5 parts of OP-10 and an appropriate amount of deionized water were added and heated to 75°C, and then dispersed and emulsified under stirring. 0.5 parts of potassium persulfate and an emulsion prepared from 48 parts of methyl methacrylate, 42 parts of butyl acrylate and 10 parts of methacrylic acid were added dropwise, and the reaction was carried out for 3 hours. Then, 25 parts of a mixture of vinyl triisopropoxy silane and dimethyl dimethoxy silane was added dropwise within 4 hours, and the reaction was carried out at 80°C for a period of time. After the addition was completed, the temperature was raised to 85°C, and the reaction was continued for about 1 hour to complete the reaction. Then, the temperature was lowered, and the product was discharged.

[0044] In the specific embodiment, 12 examples and 8 comparative examples are provided. The combinations and mass percentages of examples 1 to 12 are shown in table 1, and the combinations and mass percentages of comparative examples 1 to 8 are shown in table 2.

[0045] Table 1

[0046]

[0047]

[0048]

[0049] Table 2

[0050]

[0051]

[0052] From the above Table 1 and Table 2, it can be seen that, compared with Example 1, Comparative Example 1 does not contain the second photocurable monomer; Comparative Example 2 does not contain the first photocurable monomer; Comparative Example 3 does not contain the second photoinitiator; Comparative Example 4 does not contain the first photoinitiator; Comparative Example 5 the ratio of the first photocurable monomer and the second photocurable monomer is less than 3:7; Comparative Example 6 the ratio of the first photocurable monomer and the second photocurable monomer is greater than 5:8; Comparative Example 7 the ratio of the first photoinitiator and the second photoinitiator is less than 8:3; and Comparative Example 8 the ratio of the first photoinitiator and the second photoinitiator is greater than 7:2.

[0053] Inks were prepared according to the components of Examples 1 to 12 and Comparative Examples 1 to 8 in Table 1 and Table 2, and the Examples 1 to 12 and Comparative Examples 1 to 8 were subjected to curing effect test, rubbing resistance test and overprint test.

[0054] The curing effect test method is specifically as follows: a label printer was used to print at a printing speed of 70 m / min to 80 m / min, and after printing, the printed sample was subjected to 395 nm LED light source and 365 nm mercury lamp light source, and the curing effect was observed.

[0055] The rubbing resistance test method is specifically as follows: the ink was printed on a double transparent film using the same printing conditions, and the printed double transparent film was rubbed 3 to 5 times, and the ink layer was observed.

[0056] The overprint test method is as follows: printing in the same printing condition according to the ink head sequence WCMYK, printing three-color inks with the same components except for pigments one by one, it should be noted that the pigments corresponding to the various colors used in the examples and comparative examples are the same, observing whether the printed ink layer can completely flow on the previously printed ink layer, and observing the overprint printing result. Generally speaking, if the ink layer is not completely cured, there is no need to do overprint test, if the ink is observed to be completely cured, but the overprint test result is poor, there are the following problems: first, if the overprint test result appears wrinkles, then it means that the surface of the ink is well cured, but there are a large number of uncured parts inside. Second, if the overprint test result is poor in color performance, it means that there are invisible uncured parts inside the ink, and part of the newly printed ink penetrates into the previously printed ink, resulting in that the color performance of the newly printed ink cannot reach the normal color performance, so the color performance is poor.

[0057] The test results of examples 1 to 12 and comparative examples 1 to 8 are shown in the following table 3.

[0058] Table 3

[0059]

[0060]

[0061] From table 3, it can be seen that the ratio of the first light-curable monomer and the second light-curable monomer in the ink of the examples is 3:7-5:8, the ratio of the first light initiator and the second light initiator is 8:3-7:2, the printing product obtained by printing using the ink of the examples has good curing effect and can be completely cured, no falling off when kneading, and the overprint test result is good, that is, the color performance of each color in the overprint test process is normal. Referring to Figure 1 , the printing product printed using the ink of example 1 and the ink with the same components except for pigments has clear color and good overprint effect. The ink in comparative example 1 does not contain the second light-curable monomer, the printing product printed using the ink of comparative example 1 and the ink with the same components except for pigments has general curing performance, and has falling off when kneading, which is not suitable for overprint test. Referring to Figure 2Comparative Example 2 does not contain the first photo-curable monomer, the test result is general in curing performance, a small part of the ink layer falls off when rubbing, and wrinkles appear during the overprint test. Comparative Example 3 does not contain the second photo-initiator, the test result is not completely cured, the ink layer falls off when rubbing, and is not suitable for overprint test; Comparative Example 4 does not contain the first photo-initiator, the test result is not completely cured, the ink layer falls off when rubbing, and is not suitable for overprint test; Comparative Example 5 has a ratio of the first photo-curable monomer and the second photo-curable monomer less than 3:7, the curing effect is good, no ink layer falls off when rubbing, but poor color appears during the overprint test, i.e. there is still an un-cured part in the ink which is invisible to the naked eye; Comparative Example 6 has a ratio of the first photo-curable monomer and the second photo-curable monomer greater than 5:8, the curing effect is good, no ink layer falls off when rubbing, but poor color appears during the overprint test, i.e. there is still an un-cured part in the ink which is invisible to the naked eye; Comparative Example 7 has a ratio of the first photo-initiator and the second photo-initiator less than 8:3, the curing effect is good, no ink layer falls off when rubbing, but poor color appears during the overprint test, i.e. there is still an un-cured part in the ink which is invisible to the naked eye; Comparative Example 8 has a ratio of the first photo-initiator and the second photo-initiator greater than 7:2, the curing effect is good, no ink layer falls off when rubbing, but poor color appears during the overprint test, i.e. there is still an un-cured part in the ink which is invisible to the naked eye.

[0062] Finally, it should be emphasized that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1.A high-speed printing UV ink, comprising a photocurable monomer, a photoinitiator and a resin, characterized in that: the photocurable monomer comprises a first photocurable monomer and a second photocurable monomer, the first photocurable monomer is a siloxane-modified acrylate, the second photocurable monomer has a Tg lower than 0℃ and a carbon chain length greater than or equal to 5, and the second photocurable monomer is selected from at least one of lauryl acrylate, ethoxyethoxyethyl acrylate; the ratio of the first photocurable monomer to the second photocurable monomer is 3:7 to 5:8; the photoinitiator comprises a first photoinitiator and a second photoinitiator, the first photoinitiator is an LED lamp long-wavelength photoinitiator, the second photoinitiator is a thioxanthone photoinitiator, and the ratio of the first photoinitiator to the second photoinitiator is 8:3 to 7:2; the first photoinitiator is selected from at least one of diphenyl-(2,4,6-trimethylbenzoyl)-phosphine oxide, 1,5-di(thiophen-2-yl)pent-1,4-dien-3-one, 2,6-bis(thiophen-2-ylmethyl)cyclohexanone and 4,4-dimethyl-2,6-bis(thiophen-2-ylmethyl)cyclohexanone; and the second photoinitiator is selected from at least one of 2-isopropylthioxanthone and 2,4-diethylthioxanthone. 2.The high-speed printing UV ink according to claim 1, characterized in that: the resin is selected from at least one of polyurethane acrylate oligomer, epoxy acrylate oligomer and polyester acrylate oligomer. 3.The high-speed printing UV ink according to claim 1, characterized in that: the siloxane-modified acrylate is prepared by reacting organosiloxane with acrylate monomers in the presence of an acid catalyst, an emulsifier and an initiator. 4.The high-speed printing UV ink according to any one of claims 1 to 3, characterized in that: the high-speed printing UV ink comprises 5% to 30% of a color paste, 1% to 30% of the resin, 25% to 60% of the photocurable monomer, 2% to 10% of the photoinitiator, 1% to 2% of a light stabilizer, 0.5% to 1% of a polymerization inhibitor and 0% to 5% of a leveling agent, in terms of mass percentage. 5.The high-speed printing UV ink according to claim 4, characterized in that: the light stabilizer is selected from at least one of hydroxyphenyl triazine, hydroxyphenyl benzotriazole, benzophenone, oxanilide, cyanoacrylate and salicylate. 6.The high-speed printing UV ink according to claim 4, characterized in that: the polymerization inhibitor is 4-methoxyphenol. 7.The high-speed printing UV ink according to claim 4, characterized in that: the leveling agent is selected from at least one of BYK 333, BYK 3510 and EFKA 3277. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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