CN110564213A - LED-UV ink-jet printing ink and preparation method and application thereof - Google Patents

Abstract

The invention relates to LED-UV ink-jet printing ink and a preparation method and application thereof. The ink comprises the following components in percentage by mass: 2-5% of pigment, 0.5-2.5% of dispersing agent, 5-20% of prepolymer, 1-4% of pure acrylic resin or vinyl chloride-vinyl acetate resin, 30-80% of active diluent, 5-10% of photoinitiator, 0.03-0.1% of flatting agent and 0.01-0.1% of polymerization inhibitor. The method comprises the following steps: grinding and dispersing the pigment, the dispersing agent, the prepolymer and part of the active diluent, adding pure acrylic acid or vinyl chloride-vinyl acetate copolymer, the photoinitiator, the flatting agent, the polymerization inhibitor and the balance of the active diluent, mixing, stirring uniformly, centrifuging and filtering. The ink has the advantages of good adhesive force, flexibility, printability and the like, and can be suitable for various flexible base materials such as PVC, TPU, soft films, lamp sheets, vehicle stickers and the like.

Description

LED-UV ink-jet printing ink and preparation method and application thereof

Technical Field

The invention belongs to the field of ultraviolet curing ink and preparation and application thereof, and particularly relates to LED-UV ink-jet printing ink and a preparation method and application thereof.

background

With the rapid development of digital ink-jet printing, various digital ink-jet printing inks are in the way. The digital ink-jet printing ink mainly comprises: water-based inks, solvent-based inks, Ultraviolet (UV) inks. The water-based ink also comprises water-based dye ink and pigment ink, and the water-based dye ink is easy to decompose and has poor outdoor weather resistance, so the water-based dye ink is not adopted by most outdoor customers, while the water-based pigment ink has no penetrability on a flexible non-absorbent substrate, is slow in water volatilization and drying, and has insufficient precision of a printed picture, so the development of the water-based pigment ink is limited. Although many manufacturers develop weak solvent ink, the environmental pollution is reduced compared with solvent ink, but it is not practical to completely avoid the environmental pollution caused by solvent volatilization. The Ultraviolet (UV) ink can perfectly avoid the problems of slow drying of water-based ink and environmental pollution caused by solvent-based ink, so that the Ultraviolet (UV) ink-jet printing technology is greatly developed. Compared with the traditional mercury lamp UV ink, the ultraviolet LED-UV ink has incomparable advantages, the LED-UV ink is solidified and dried by adopting an LED lamp cold light source after being printed, no heat is generated in the production process, the phenomena of folds and bubbles caused by heating of a substrate with poor heat resistance are avoided, ozone is not generated in the use process, the emission of carbon dioxide is greatly reduced, the service life of the LED lamp is long, the energy is saved, preheating and cooling are not needed, the effect of stopping along with starting can be achieved, the time is saved, and the production efficiency is improved.

In the field of digital ink-jet printing, UV ink has incomparable advantages compared with water-based ink and solvent-based ink, and the UV ink-jet printing technology is rapidly developed within a period of time, but the UV ink mainly uses traditional mercury lamp UV ink, the domestic LED-UV is still in the primary research stage, the patents disclosed aiming at the LED-UV ink are not numerous, the patents disclosed aiming at the UV-LED ink at present comprise CN102732094A, CN1027191143A and CN103045007A which are all suitable for screen printing, the related patents comprise CN1036138988A, CN103613989A, CN105153810A, CN105602345A, CN106280689A and CN106280689A, the research on the aspects of water resistance, solvent resistance, curing speed, printing fluency and the like of the ink is not carried out, the adhesion and the flexibility described in the text are only limited to substrates with better printing adhesion and low flexibility requirement, and the practical application process finds that the ink has low surface energy, high adhesion, and high flexibility, The adhesion of some flexible substrates without surface treatment is not ideal, and patent CN104497707A which is definitely used for ink-jet printing does not make special research on the aspects of adhesion and flexibility, and the ink is used for EPSON nozzles rather than large industrial nozzles, and patent CN108841237A and patent CN201810335215.7 also add vinyl chloride-vinyl acetate resin into the ink, but do not add prepolymer resin, obviously, the cured film has insufficient crosslinking density, and the scratch resistance and the adhesion are also deteriorated.

Disclosure of Invention

The invention aims to solve the technical problem of providing an LED-UV ink-jet printing ink and a preparation method and application thereof, so as to overcome the defects that the UV ink in the prior art has poor adhesion to a flexible substrate with low surface energy, poor surface treatment or no surface treatment and cannot be used for substrates (such as leather and soft films) with higher requirements on flexibility.

The invention provides LED-UV ink-jet printing ink which comprises the following components in percentage by mass: 2-5% of pigment, 0.5-2.5% of dispersing agent, 5-20% of prepolymer, 1-4% of pure acrylic resin or vinyl chloride-vinyl acetate copolymer, 30-80% of active diluent, 5-10% of photoinitiator, 0.03-0.1% of flatting agent and 0.01-0.1% of polymerization inhibitor; wherein the prepolymer is prepared from the following components in percentage by mass: 1-5: 3 of aliphatic urethane acrylate and polyester acrylate.

The pigment comprises four basic color pigments of organic pigment phthalocyanine blue, phthalocyanine red, phthalocyanine yellow or inorganic pigment carbon black.

The pigment includes one of four primary colors of c.i. pigment blue 15:3, c.i. pigment blue 15:4, c.i. pigment red 122, c.i. pigment red 202, c.i. pigment red 170, c.i. pigment yellow 150, c.i. pigment yellow 151, c.i. pigment yellow 155, and c.i. pigment black 7.

The dispersant is a hyperdispersant with an anchoring group, and the hyperdispersant with the anchoring group comprises one or two of EFKA7701, EFKA7731, UNIQ9520, UNIQ9510 and UNIQ 9530.

the aliphatic polyurethane acrylate is one of CN964, CN965NS, CN966J75NS, CN980NS and CN991 NS.

the polyester acrylate is one of CN2262, CN3108NS, CN2283NS, CN7001NS and CN 704.

The pure acrylic resin is UV1125-A2 or UV 1125-5B.

The vinyl chloride-vinyl acetate copolymer resin is one or more of E15/45A, E15/45M, E22/48A, E15/40A.

The reactive diluent is a monofunctional monomer with good flexibility, and the monofunctional monomer is two or more of vinyl morpholine, acryloyl morpholine, isobornyl acrylate, 2-phenoxyethyl acrylate, tetrahydrofuran methacrylate, dodecyl methacrylate, trimethylolpropane formal acrylate, 3, 5-trimethylcyclohexane acrylate, N-vinyl caprolactam, N-vinyl pyrrolidone and propylene caprolactone.

the photoinitiator is a deep curing initiator acyl phosphine oxide compound which has stronger absorption in the LED emission wavelength and a surface dry initiator thioxanthone compound.

The deep curing initiator acylphosphine oxide is one of 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, ethyl (2,4, 6-trimethylbenzoyl) -phenylphosphate and phenyl bis (2,4, 6-trimethylbenzoyl) phosphine oxide.

The surface drying initiator thioxanthone is 2-isopropyl thioxanthone or 2, 4-diethyl thioxanthone.

the leveling agent is a reaction type organic siloxane modified leveling agent.

The leveling agent is one or more of UV special leveling agents Red 2100N, Red 2200N, Glide 432.

The polymerization inhibitor is an amine or phenol polymerization inhibitor.

The polymerization inhibitor is one of 2, 6-di-tert-butyl-p-phenylphenol, vulcanized diphenylamine and p-methylphenol.

The invention also provides a preparation method of the LED-UV ink-jet printing ink, which comprises the following steps:

And grinding and dispersing the pigment, the dispersing agent, the prepolymer and 20-50% of active diluent, adding pure acrylic acid or vinyl chloride-vinyl acetate copolymer, a photoinitiator, a flatting agent, a polymerization inhibitor and the balance of active diluent, mixing, uniformly stirring, centrifuging and filtering to obtain the LED-UV ink-jet printing ink.

The rotation speed of the grinding is 3000-5000 rad/min.

The grinding dispersion time is 2-6 h.

The stirring speed is 2000-4000 rad/min, and the stirring time is 30-80 min.

The centrifugal rotating speed is 2000-5000 rad/min, and the centrifugal time is 20-50 min.

The filtration was with a 0.5 μm microporous membrane.

The invention also provides application of the LED-UV ink-jet printing ink in a flexible substrate. For example, the four basic colors of LED-UV ink are respectively put into a black ink box of an ink-jet printer, the required color and pattern are printed on various flexible substrates through a computer, and the flexible substrates are cured by LED lamps.

The ink can be suitable for industrial nozzles such as Ricoh (RICOH), Konika (KONICA), Kyocera (KYOCERA), SeIKO and the like.

The wavelength of the LED lamp is 395 nm.

The LED-UV ink does not contain any organic solvent in the formula, adopts a cold light source LED lamp for curing and drying, and has the excellent characteristics of energy conservation and environmental protection. Because a small amount of non-reactive pure acrylic acid or vinyl chloride-vinyl acetate copolymer resin is added into the formula and is in synergistic crosslinking with the prepolymer resin to form a film, the film forming cohesion is reduced, the ink adhesion and flexibility are greatly improved, two problems of difficult adhesion and high flexibility requirement of the ink on a base material are perfectly solved, and the ink can be basically used for various flexible base materials.

The viscosity of the LED-UV ink-jet printing ink at 40 ℃ is 8-15 cp, the surface tension at 25 ℃ is 20-35 mN/m, and the average particle size is 150-250 nm.

Advantageous effects

(1) The LED-UV ink-jet printing ink has very good adhesive force. Because the non-reactive pure acrylic resin or vinyl chloride-vinyl acetate resin is added into the ink formula, the adhesive force of the ink is obviously improved on a flexible base material which has low surface energy, poor surface treatment or unprocessed and is difficult to adhere.

(2) The LED-UV ink-jet printing ink disclosed by the invention is good in flexibility. Because pure acrylic resin or vinyl chloride-vinyl acetate resin is added into the formula, the flexibility of leather and soft films with high flexibility requirements is greatly improved.

(3) The LED-UV ink-jet printing ink has universality on different flexible substrates. It is suitable for the substrate with low or no treatment.

(4) The invention has little pollution to environment and low energy consumption.

(5) The LED-UV ink-jet printing ink has good printing performance. The ink has the advantages of fast curing, good fluency, bright color, vivid and vivid picture, and excellent adhesive force and flexibility.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

The pigment c.i. pigment blue 15:3, c.i. pigment blue 15:4, c.i. pigment red 122, c.i. pigment red 202, c.i. pigment red 170, c.i. pigment yellow 150, c.i. pigment yellow 151, c.i. pigment yellow 155 of the present invention are available from clariant chemical (china) ltd; c.i. pigment black 7 is available from mitsubishi chemical company, japan.

The aliphatic urethane acrylates of the present invention CN964, CN965NS, CN966J75NS, CN980NS, CN991NS and polyester acrylates CN2262, CN3108NS, CN2283NS, CN7001NS, CN704 are all available from sandoduma chemical limited.

the pure acrylic resins UV1125-A2 and UV1125-5B of the invention are available from Chinesia kukaki Kaisha chemical Co., Ltd, and the vinyl chloride-vinyl acetate resin E15/45A, E15/45M, E22/48A, E15/40A is available from Wake chemical Co., Germany.

Monofunctional monomers of the invention: vinyl morpholine, acryloyl morpholine, isobornyl acrylate, 2-phenoxyethyl acrylate, tetrahydrofuran methacrylate, dodecyl methacrylate, trimethylolpropane formal acrylate, 3, 5-trimethylcyclohexane acrylate, N-vinyl caprolactam, N-vinyl pyrrolidone, propylene caprolactone are available from Shadoma Guangzhou chemical Co.

the dispersants EFKA7701 and EFKA7731 of the present invention are available from basf (china) limited, and UNIQ9510 and UNIQ9530 are available from kaika chemical (shanghai) limited.

The UV specific levelling agent Red 2100N, Red 2200N, Glide 432 of the present invention is commercially available from dego, germany.

The polymerization inhibitor 2, 6-di-tert-butyl-p-phenylphenol, the vulcanized diphenylamine and the p-methylphenol can be purchased from IGM company in the Netherlands.

Example 1

This example provides a blue LED-UV ink for flexible substrates having the formulation shown in table 1:

TABLE 1

According to the formula listed in table 1, firstly adding the pigment, the dispersing agent, the prepolymer and the 2-phenoxyethyl acrylate monomer into a grinding machine, grinding and dispersing for 4h at the rotating speed of 4500rad/min, adding the rest of the monomer, the pure acrylic resin, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 60min at the rotating speed of 2500rad/min (the temperature in the stirring process is not higher than 50 ℃, centrifuging for 35min at the rotating speed of 3000rad/min, and finally filtering by using a filter membrane of 0.5 mu m to obtain the blue LED-UV ink for the flexible substrate.

Example 2

This example provides a red LED-UV ink for flexible substrates having a formulation as shown in table 2:

TABLE 2

According to the formula listed in table 2, firstly adding the pigment, the dispersing agent, the prepolymer and the 2-phenoxyethyl acrylate monomer into a grinding machine, grinding and dispersing for 5 hours at the rotating speed of 4000rad/min, adding the rest monomer, pure acrylic acid diluted acid, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 50 minutes at the rotating speed of 3000rad/min (the temperature in the stirring process is not higher than 50 ℃, centrifuging for 30 minutes at the rotating speed of 4000rad/min, and finally filtering by using a filter membrane of 0.5 mu m to obtain the red LED-UV ink for the flexible substrate.

Example 3

This example provides a yellow LED-UV ink for flexible substrates having a formulation as shown in table 3:

TABLE 3

According to the formula listed in Table 3, firstly adding the pigment, the dispersing agent, the prepolymer and the tetrahydrofuran methacrylate monomer into a grinding machine, grinding and dispersing for 4h at the rotating speed of 4500rad/min, adding the rest monomer, the vinyl chloride/acetate copolymer, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 70min at the rotating speed of 2500rad/min (the temperature in the stirring process is not higher than 50 ℃, centrifuging for 45min at the rotating speed of 3500rad/min, and finally filtering by a filter membrane of 0.5 mu m to obtain the yellow LED-UV ink for the flexible substrate.

Example 4

This example provides a black LED-UV ink for flexible substrates having the formulation shown in table 4:

TABLE 4

According to the formula listed in Table 4, firstly adding the pigment, the dispersing agent, the prepolymer and the 2-phenoxyethyl acrylate monomer into a grinding machine, grinding and dispersing for 5h at the rotating speed of 4000rad/min, adding the rest of the monomer, the vinyl chloride/acetate copolymer, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 60min at the rotating speed of 3000rad/min (the temperature in the stirring process is not higher than 50 ℃), centrifuging for 40min at the rotating speed of 4000rad/min, and finally filtering by a filter membrane of 0.5 mu m to obtain the black LED-UV ink for the flexible substrate.

Comparative example 1

This comparative example provides a blue LED-UV ink for flexible substrates having the formulation shown in table 5:

TABLE 5

According to the formula listed in Table 5, firstly adding the pigment, the dispersing agent, the prepolymer and the 2-phenoxyethyl acrylate monomer into a grinding machine, grinding and dispersing for 4h at the rotating speed of 4500rad/min, adding the rest of the monomer, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 60min at the rotating speed of 2500rad/min (the temperature in the stirring process is not higher than 50 ℃), centrifuging for 35min at the rotating speed of 3000rad/min, and finally filtering by using a filter membrane of 0.5 mu m to obtain the blue LED-UV ink for the flexible base material.

Comparative example 2

This comparative example provides a yellow LED-UV ink for flexible substrates having the formulation shown in table 6:

TABLE 6

According to the formula listed in table 6, firstly adding the pigment, the dispersing agent, the prepolymer and the tetrahydrofuran methacrylate monomer into a grinding machine, grinding and dispersing for 4h at the rotating speed of 4500rad/min, adding the rest of the monomer, the photoinitiator, the flatting agent and the polymerization inhibitor after the dispersion is finished, continuously stirring for 70min at the rotating speed of 2500rad/min (the temperature in the stirring process is not higher than 50 ℃), centrifuging for 45min at the rotating speed of 3500rad/min, and finally filtering by using a filter membrane of 0.5 mu m to obtain the yellow LED-UV ink for the flexible substrate.

The inks obtained in examples 1 to 4 and comparative examples 1 to 2 were subjected to performance tests in the following manner:

1. Viscosity testing was performed using a U.S. Bohler fly DVZTLV rotational viscometer.

2. Surface tension test, adopting BZY-1 full-braking surface tension meter of Shanghai Pingxuan scientific instruments Co.

3. And (4) testing the particle size, wherein the particle size is tested by adopting a Marvens Nano-S900 test.

4. And (3) fluency testing, namely testing by adopting a Dill NEOTITAN UVT-1606 machine, wherein a machine spray head is a KONICA spray head, an LED lamp with the wavelength of 395nm is cured, and 30 square meters are continuously printed, wherein the quantity of plugs is preferably less than 5, preferably 5-10 and poorly greater than 10.

5. And (3) curing test, namely testing by using a finger pressing method, pressing the printed cured substrate by using a thumb, and rotating the printed cured substrate back and forth for 10 times, wherein the thumb is excellent in no color, good in slight color and poor in color.

6. Testing water resistance, cutting the printed PVC sample into 4cm²The small blocks are soaked in water at the temperature of 25 ℃ for 24 hours, and the sample is taken out to observe whether the phenomenon of bubble falling exists, the sample is excellent if no change exists, and the phenomenon of bubble falling is poor if the bubbles fall.

7. and (3) testing the adhesive force, namely testing the adhesive force by adopting a hundred-grid method, sticking the adhesive force once by using a 3M (600 high-grade transparent adhesive tape) after drawing hundred grids, and testing the adhesive force of the adhesive force on a base material PVC, lamp box cloth, leather, a soft film, an electrostatic sticker, a high-gloss white lamp piece and PP, wherein the adhesive force is excellent without any falling, the falling is less than 10 grids and is good, and the falling is 10-20 grids and is poor when the falling is more than 20 grids.

8. The flexibility test is usually carried out by using a mandrel method at present, the test is carried out for more obvious comparison flexibility, the leather and the soft film which have high flexibility requirements are printed and cured and then folded for 5 times, the condition of the film layer after being folded is seen, no change is optimal, the fold is good, and the fracture phenomenon is poor.

The results of the above tests are shown in Table 7:

TABLE 7 ink Performance test results

Comparative example 1 compares with example 1, comparative example 2 compares with example 3 formulation, the formulation is basically identical, only add non-reactive pure acrylic resin or vinyl chloride-acetate copolymer in the comparative example, it can be seen from table 7 that the adhesion is far inferior to that of the examples on the base material leather, electrostatic paste, lamp sheet and PP which are difficult to adhere, and the flexibility is also inferior to that of the examples on the leather and soft film which have high flexibility requirement.

As can be seen from the test results of the examples, the ink of the invention has excellent fluency, curing condition, water resistance, adhesion and flexibility.

Claims (9)

1. An LED-UV ink-jet printing ink is characterized in that the ink comprises the following components in percentage by mass: 2-5% of pigment, 0.5-2.5% of dispersing agent, 5-20% of prepolymer, 1-4% of pure acrylic resin or vinyl chloride-vinyl acetate copolymer, 30-80% of active diluent, 5-10% of photoinitiator, 0.03-0.1% of flatting agent and 0.01-0.1% of polymerization inhibitor; wherein the prepolymer is prepared from the following components in percentage by mass: 1-5: 3 of aliphatic urethane acrylate and polyester acrylate.

2. the ink of claim 1, wherein the pigment comprises four basic color pigments of an organic pigment phthalocyanine blue, a phthalocyanine red, a phthalocyanine yellow, or an inorganic pigment carbon black.

3. The ink of claim 1, wherein the dispersant is an anchoring group-containing hyperdispersant comprising one or both of EFKA7701, EFKA7731, UNIQ9520, UNIQ9510, and UNIQ 9530.

4. The ink of claim 1, wherein the aliphatic urethane acrylate is one of CN964, CN965NS, CN966J75NS, CN980NS, CN991 NS; the polyester acrylate is one of CN2262, CN3108NS, CN2283NS, CN7001NS and CN 704.

5. The ink of claim 1, wherein the pure acrylic resin is UV1125-a2 or UV 1125-5B; the vinyl chloride-vinyl acetate copolymer resin is one or more of E15/45A, E15/45M, E22/48A, E15/40A.

6. The ink of claim 1, wherein the reactive diluent is two or more selected from the group consisting of vinyl morpholine, acryloyl morpholine, isobornyl acrylate, 2-phenoxyethyl acrylate, tetrahydrofuran methacrylate, dodecyl methacrylate, trimethylolpropane formal acrylate, 3, 5-trimethylcyclohexane acrylate, N-vinyl caprolactam, N-vinyl pyrrolidone, and propylene caprolactone.

7. The ink of claim 1, wherein the photoinitiator is a deep-cure initiator, a complex of acylphosphine oxides and a surface-dry initiator, a thioxanthone; the flatting agent is a reaction type organic siloxane modified flatting agent; the polymerization inhibitor is amine or phenol polymerization inhibitor.

8. A method of making the ink of claim 1, comprising:

And grinding and dispersing the pigment, the dispersing agent, the prepolymer and 20-50% of active diluent, adding pure acrylic acid or vinyl chloride-vinyl acetate copolymer, a photoinitiator, a flatting agent, a polymerization inhibitor and the balance of active diluent, mixing, uniformly stirring, centrifuging and filtering to obtain the LED-UV ink-jet printing ink.

9. Use of the ink of claim 1 in a flexible substrate.