A high flexibility uv offset ink and a method for preparing the same

Abstract

The application relates to the technical field of UV offset printing inks, and specifically discloses a high-flexibility UV offset printing ink and a preparation method thereof. The high-flexibility UV offset printing ink comprises the following components in parts by weight: modified polyester acrylic resin 25-30 parts; toughening composition 2.3-3.1 parts; monomer 20-30 parts; pigment 30-45 parts; initiator 6-10 parts; assistant initiator 0-5 parts; and filler 5-10 parts. The preparation raw material of the toughening composition comprises nanocellulose, sodium humate and silane coupling agent. The preparation method of the high-flexibility UV offset printing ink comprises the following steps: dispersing modified polyester acrylic resin, the toughening composition, the monomer, the pigment, the initiator, the assistant initiator and the filler, and obtaining the product. The critical load intensity of the high-flexibility UV offset printing ink provided by the application can reach 13.2 N or more, and the high-flexibility UV offset printing ink has the advantages of high flexibility, high adhesion and low brittleness.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of UV offset inks, in particular to a high-flexibility UV offset ink and a preparation method thereof. BACKGROUND

[0002] The UV offset ink can be converted from a liquid state into a solid state under the irradiation of ultraviolet light of a certain wavelength, and is usually composed of pigments, prepolymers, active diluents, photoinitiators and auxiliaries, has the advantages of containing no volatile solvent, no odor, no irritation, good leveling, no blocking, strong water resistance, strong solvent resistance and the like, and is suitable for printing on materials such as silver card paper and laser paper.

[0003] At present, there is a UV offset ink which uses a single epoxy resin-based prepolymer to solve the technical problems of dark gloss of printed products, difficulty in adjusting the oiliness of the ink and difficulty in adapting to complex printing process requirements when the UV offset ink uses two or more resins as prepolymers.

[0004] Since the molecular of the epoxy resin-based prepolymer contains a large number of rigid groups, the flexibility of the molecular chain is low, which leads to cracking and fragmentation of the prepared offset ink after being bent for several times, and finally the small pieces are peeled off, affecting the use. SUMMARY

[0005] In order to improve the flexibility of the ink and reduce the cracking of the ink during use, the application provides a high-flexibility UV offset ink and a preparation method thereof.

[0006] In the first aspect, the application provides a high-flexibility UV offset ink, which adopts the following technical scheme:

[0007] A high-flexibility UV offset ink comprises the following components in parts by weight:

[0008] 25-30 parts of modified polyester acrylic resin;

[0009] 2.3-3.1 parts of toughening composition;

[0010] 20-30 parts of monomer;

[0011] 30-45 parts of pigment;

[0012] 6-10 parts of initiator;

[0013] 0-5 parts of co-initiator;

[0014] 5-10 parts of filler;

[0015] The preparation raw materials of the toughening composition include nanocellulose, sodium humate and silane coupling agent.

[0016] By adopting the technical scheme, the modified polyester acrylic resin has better toughness and tensile strength than the epoxy resin, the toughness of the ink is further improved by adding the toughening composition, and the ink is less prone to cracking due to the combination of the two.

[0017] The nanocellulose as a toughening material can directly improve the toughness of the ink, but the compatibility between the nanocellulose and the ink components is poor, and as the content of the nanocellulose increases, serious agglomeration occurs, reducing the toughening effect; the silane coupling agent forms a coating layer on the surface of the nanocellulose, improves the interface performance, forms a layer similar to "lubrication", and hinders the agglomeration of the nanocellulose; the sodium humate is dissociated into humic acid and sodium ions in water, the humic acid increases the electronegativity of the nanocellulose, and forms a double electric layer with the sodium ions, supplemented by the silane coupling agent, so that the coating layer on the surface of the nanocellulose is thickened, the dispersibility of the nanocellulose in the ink is further improved, and the toughening composition has a significant toughening effect on the ink.

[0018] Through flexibility detection, the critical load of the ink without adding the toughening composition is 7.6N, the critical load of the ink when the nanocellulose is added instead of the toughening composition is 8.8N, and the critical load of the ink when the toughening composition is added in an amount equal to that of the nanocellulose is 14.5N.

[0019] Optionally, the weight ratio of the nanocellulose to the silane coupling agent is 1:(0.05-0.1).

[0020] By adopting the technical scheme, when the amount of the silane coupling agent is within the above range, the combination effect with the nanocellulose is better, the coating effect is better, and the toughening composition effectively improves the toughness of the ink.

[0021] Optionally, the weight ratio of the nanocellulose to the sodium humate is 1:(0.15-0.2).

[0022] By adopting the technical scheme, the critical load of the ink after adding an equal amount of the toughening composition without sodium humate is 9.0N, and the toughening effect of the significant toughening composition on the ink is improved after adding the sodium humate within the above range.

[0023] Optionally, the preparation method of the toughening composition is as follows:

[0024] S1, adding nanocellulose and sodium humate into water, dispersing to obtain a mixed solution A;

[0025] S2, adding a silane coupling agent into the mixed solution A, dispersing, standing, removing the filtrate by filtration, and drying to obtain the toughening composition.

[0026] Optionally, the dispersion conditions in step S2 are stirring at 55-65℃ for 25-35min.

[0027] By adopting the technical scheme, the coating effect is better, the dispersibility of the toughening composition in the ink is better, and the toughness of the ink is better.

[0028] Optionally, the step S2 adds the silane coupling agent to the mixed solution A, and blueberry anthocyanins are also added.

[0029] The weight ratio of the added amount of the blueberry anthocyanins to the nanocellulose is (0.2-0.28):1.

[0030] By adopting the technical scheme, the blueberry anthocyanins contain a large amount of cyanidin-3-arabinoside and other glycosides, which form hydrogen bonds with the nanocellulose, enter and further thicken the coating film, further improve the dispersibility of the toughening composition in the ink, and further improve the toughening effect on the ink.

[0031] Through detection, when the blueberry anthocyanins are not added, the critical load of the ink is only 15.3 N, and when the blueberry anthocyanins are added, the critical load of the ink is increased to 18.8-19.3 N, and the toughness of the prepared ink is high and is not easy to break.

[0032] Optionally, the initiator is one or more of a photoinitiator 379, a photoinitiator DETX, and a photoinitiator 184.

[0033] By adopting the technical scheme, the ink of the present application has lower requirements for components, the above-mentioned photoinitiators can be used in the ink, and a kind of ink with better performance is prepared.

[0034] Optionally, the filler is one or both of magnesium carbonate and solid paraffin.

[0035] Optionally, the monomer is one or more of propoxylated glyceryl triacrylate, bis-trimethylolpropane tetraacrylate, dipentaerythritol penta-hexa-acrylate, and ethoxylated trimethylolpropane triacrylate.

[0036] By adopting the technical scheme, the ink of the present application has lower requirements for components, the above-mentioned monomers can be used in the ink, and a kind of ink with better performance is prepared.

[0037] In a second aspect, the present application provides a preparation method of a high-flexibility UV offset printing ink, which adopts the following technical scheme:

[0038] A preparation method of a high-flexibility UV offset printing ink, comprising the following steps:

[0039] The modified polyester acrylic resin, the toughening composition, the monomer, the pigment, the initiator, the co-initiator, and the filler are dispersed, and a product is obtained.

[0040] By adopting the technical scheme, the steps are less, the process is simple and efficient, which is beneficial to the industrialized scale preparation of the UV offset printing ink, and the prepared ink has excellent flexibility, good crack resistance, and adhesion and water resistance meeting the use requirements.

[0041] In summary, the present application has the following beneficial effects:

[0042] 1. The modified polyester acrylic resin and the toughening composition are compounded in the present application, the sodium humate and the silane coupling agent in the toughening composition form a thick layer on the surface of the nanocellulose, which has a lubricating effect, hinders agglomeration, improves the dispersibility of the nanocellulose, and further improves the toughening effect of the nanocellulose on the ink;

[0043] The critical load of the ink added with the toughening composition is as high as 13.2N or more, which is significantly higher than the critical load 7.6N of the ink without the toughening composition, and the toughness of the ink can be significantly enhanced;

[0044] 2. The use amounts of the nanocellulose, the silane coupling agent, and the sodium humate are controlled in the present application to improve the compounding effect, and further promote the better toughening effect of the toughening composition on the ink;

[0045] 3. The toughening composition of the present application further adds blueberry anthocyanins, which contain glycosides such as cyanidin-3-arabinoside and form hydrogen bond connection with nanocellulose, thereby further thickening the coating film, further improving the dispersibility of the toughening composition in the ink, and further improving the toughening effect on the ink;

[0046] The critical load of the ink added with the blueberry anthocyanins is as high as 18.8N or more, which is significantly higher than the critical load 15.3N of the ink without the blueberry anthocyanins, and the toughness of the ink is further enhanced. DETAILED DESCRIPTION

[0047] The present application will be further described in detail below in combination with examples.

[0048] The components except the following description are derived from commercial sources:

[0049] The nanocellulose is from Wuhan Huaxiang Kejia Biotechnology Co., Ltd., and the model number is D4234;

[0050] The sodium humate is from Erlieke (Shandong) Chemical Group Co., Ltd., and is sieved through a 200-mesh screen after ball milling for use;

[0051] The blueberry anthocyanins are from Xi'an Shilin Biotechnology Co., Ltd., and the model number is HH91209GEFBG;

[0052] The modified polyester acrylic resin is from Guangdong Keding Functional Materials Co., Ltd., and the trade name is MR7361;

[0053] Solid paraffin, Hebei Bangtitan Chemical Co., Ltd., grade 58.

[0054] Preparation Example 1

[0055] A toughening composition, each component and its corresponding weight is shown in Table 1, and is prepared by the following steps:

[0056] S1, add nanocellulose and sodium humate into water, stir and mix at a speed of 500 rpm for 10 min to obtain a mixed solution A; S2, add silane coupling agent KH560 into the mixed solution A, stir and mix at 55℃ for 35 min, stand for 20 min, remove the filtrate by filtration, and dry at 60℃ for 12 h to obtain the toughening composition.

[0057] Preparation Example 2

[0058] A toughening composition, each component and its corresponding weight is shown in Table 1, and is prepared by the following steps:

[0059] S1, add nanocellulose and sodium humate into water, stir and mix at a speed of 500 rpm for 10 min to obtain a mixed solution A; S2, add silane coupling agent KH560 into the mixed solution A, stir and mix at 60℃ for 30 min, stand for 20 min, remove the filtrate by filtration, and dry at 60℃ for 12 h to obtain the toughening composition.

[0060] Preparation Example 3

[0061] A toughening composition, each component and its corresponding weight is shown in Table 1, and is prepared by the following steps:

[0062] S1, add nanocellulose and sodium humate into water, stir and mix at a speed of 500 rpm for 10 min to obtain a mixed solution A; S2, add silane coupling agent KH560 into the mixed solution A, stir and mix at 65℃ for 25 min, stand for 20 min, remove the filtrate by filtration, and dry at 60℃ for 12 h to obtain the toughening composition.

[0063] Preparation Examples 4-5

[0064] A toughening composition, which is different from Preparation Example 2 in that the amount of sodium humate is different, for specific reference, see Table 1.

[0065] Preparation Examples 6-8

[0066] A toughening composition, which is different from Preparation Example 4 in that the silane coupling agent KH560 is added into the mixed solution A in step S2, and blueberry anthocyanins are also added, the amount of blueberry anthocyanins is shown in Table 1.

[0067] Table 1: Each component and its weight (kg) in Preparation Examples 1-8

[0068]

[0069]

[0070] Example 1

[0071] A high flexibility UV offset ink, each component and its corresponding weight is shown in Table 2, and is prepared by the following steps: the modified polyester acrylic resin, toughening composition (obtained from Preparation Example 1), monomer (propoxylated glyceryl triacrylate), pigment (carbon black), initiator (photoinitiator 379), co-initiator (tetraethyl Michler ketone), filler (magnesium carbonate) are dispersed at 50°C for 30 min, to obtain the high flexibility UV offset ink.

[0072] Example 2

[0073] A high flexibility UV offset ink, each component and its corresponding weight is shown in Table 2, and is prepared by the following steps: the modified polyester acrylic resin, toughening composition (obtained from Preparation Example 1), monomer (ditrimethylolpropane tetraacrylate), pigment (carbon black), initiator (photoinitiator DETX), co-initiator (tetraethyl Michler ketone), filler (solid paraffin) are dispersed at 55°C for 25 min, to obtain the high flexibility UV offset ink.

[0074] Example 3

[0075] A high flexibility UV offset ink, each component and its corresponding weight is shown in Table 2, and is prepared by the following steps: the modified polyester acrylic resin, toughening composition (obtained from Preparation Example 1), monomer (a mixture of dipentaerythritol penta-hexa-acrylate, ethoxylated trimethylolpropane triacrylate in a weight ratio of 1:1), pigment (carbon black), initiator (a mixture of photoinitiator DETX, photoinitiator 184 in a weight ratio of 1:1), co-initiator (tetraethyl Michler ketone), filler (a mixture of magnesium carbonate, solid paraffin in a weight ratio of 1:1) are dispersed at 60°C for 20 min, to obtain the high flexibility UV offset ink.

[0076] Comparative Example 1-2

[0077] A UV offset ink, which is different from Example 2 in that the amount of toughening composition is different, as shown in Table 2.

[0078] Table 2 Each component and its weight (kg) in Example 1-3, Comparative Example 1-2

[0079] Components Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Modified polyester acrylic resin 25 27.5 30 27.5 27.5 Toughened composition 2.3 2.7 3.1 0 3.5 Monomers 20 25 30 25 25 Pigments 30 37.5 45 37.5 37.5 Initiator 6 8 10 8 8 Co-initiator 0 2.5 5 2.5 2.5 Fillers 5 7.5 10 7.5 7.5

[0080] Comparative Example 3

[0081] A UV offset ink, which differs from Example 2 in that an equal amount of nanocellulose is used instead of the toughening composition.

[0082] Comparative Example 4

[0083] A toughening composition, which differs from Example 2 in that no sodium humate is added during the preparation of the toughening composition.

[0084] Examples 4-10

[0085] A high-flexibility UV offset ink, which differs from Example 2 in that the toughening composition is used according to Table 3, but the amount of the toughening composition in the offset ink remains unchanged.

[0086] Table 3 Table of use of toughening composition in Examples 4-10

[0087] Examples 4 5 6 7 8 9 10 Preparation of toughened composition 2 3 4 5 6 7 8

[0088] Performance testing

[0089] The inks prepared in the examples and comparative examples are subjected to the following performance testing, and the test results are recorded in Table 4.

[0090] Test method

[0091] 1. Flexibility: The ink is prepared into a sample according to the method in GB 9286-1998, and the sample is tested using a WS-2005 scratch tester: the load is continuously added to the scratch needle through an automatic loading mechanism, while the sample is moved to make the scratch needle scratch the surface of the ink, when the scratch needle scratches the surface of the ink, an electrical signal is generated, at this time, the load is the critical load, and the critical load value is recorded, the greater the critical load, the higher the flexibility of the ink, and the more resistant to cracking.

[0092] 2. Adhesion: tested according to GB / T 9286-1998.

[0093] 3. Water resistance: tested according to GB / T 1733-1993.

[0094] Table 4 Performance test results

[0095]

[0096]

[0097] As can be seen from Table 4, in Examples 1-3, the prepared toughening composition is used, the critical load of the prepared ink reaches 13.2-14.5 N, and the flexibility is excellent; in Comparative Example 1, no toughening composition is added, the critical load of the prepared ink is reduced to 7.6 N, and the flexibility is insufficient; in Comparative Example 3, an equal amount of nanocellulose is used instead of the toughening composition, the critical load of the ink is only 8.8 N, and the flexibility needs to be improved, which shows that the toughening composition significantly enhances the flexibility of the ink.

[0098] The reason may be that the nanocellulose contained in the toughening composition directly improves the flexibility of the ink as a toughening agent, and the compounding of sodium humate and silane coupling agent forms a relatively thick film layer on the surface of the nanocellulose, which plays a certain "lubricating" role, hinders the agglomeration of nanocellulose, improves the dispersibility of the toughening composition in the ink, and further improves the toughening effect on the ink.

[0099] Comparing Comparative Examples 3 and 4, when the toughening composition in Comparative Example 4 does not contain sodium humate, the toughening effect on the ink is similar to that of nanocellulose in Comparative Example 3, which shows that only the toughening composition containing sodium humate has a better toughening effect.

[0100] The difference between Examples 4-5 and Example 2 is that the amount of silane coupling agent used in the preparation process of the toughening composition is increased, which has little effect on the flexibility of the ink.

[0101] The difference between Examples 6-7 and Example 4 is that the amount of sodium humate used in the preparation process of the toughening composition is increased, and Example 6 is the best example, the critical load of the ink reaches 15.3 N, and the flexibility is improved.

[0102] The difference between Examples 8-10 and Example 6 is that blueberry anthocyanins are also added in the preparation process of the toughening composition, and the critical load of the ink is further improved to 18.8-19.3 N, and the blueberry anthocyanins further improve the flexibility of the ink, and the reason is that:

[0103] The large amount of cyanidin-3-arabinoside and other glycosides in blueberry anthocyanins form hydrogen bonds with the hydroxyl groups of nanocellulose, enter and further thicken the coating film thickness, further improve the dispersibility of the toughening composition in the ink, and thus further improve its toughening effect on the ink.

[0104] It should be noted that the pigments in the present application can be selected in the range of pigment red 57:1, pigment yellow 13#, phthalocyanine blue 15:3 (copper compound), carbon black, carbon black (low PAHS), titanium dioxide (TiO2), green 7#, pink 81#, gold red 48:1, gold red 53:1, purple 23#, big red (red / gold red), light blue (purple / blue), calcium carbonate, to meet the production needs of different color inks, and do not cause great influence on the performance of the ink, and only take carbon black as an example in the present application.

[0105] The specific embodiments are only an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the present specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A high flexibility UV offset ink, characterized in that, The components include the following parts by weight: 25-30 parts of modified polyester acrylic resin; 2.3-3.1 parts of toughening composition; 20-30 parts of monomer; 30-45 parts pigment; 6-10 parts of initiator; 0-5 parts of co-initiator; 5-10 parts of filler; The raw materials for preparing the toughening composition include: nanocellulose, sodium humate, and silane coupling agent; The weight ratio of the nanocellulose to the silane coupling agent is 1:(0.05-0.1). The weight ratio of nanocellulose to sodium humate is 1:(0.15-0.2). The monomer is one or more of propoxylated glycerol triacrylate, bis(trimethylolpropane)tetraacrylate, bis(pentaerythritol)pentahexaacrylate, and ethoxylated trimethylolpropane triacrylate.

2. The high flexibility UV offset ink according to claim 1, characterized in that, The toughening composition is prepared by: S1. Add nanocellulose and sodium humate to water, disperse, and obtain mixture A; S2. Add silane coupling agent to mixture A, disperse, let stand, filter to remove filtrate, and dry to obtain the final product.

3. The high-flexibility UV offset printing ink according to claim 2, characterized in that: The dispersion conditions in step S2 are: stirring and mixing at 55-65℃ for 25-35 minutes.

4. The high-flexibility UV offset printing ink according to claim 2, characterized in that: When adding the silane coupling agent to the mixture A in step S2, blueberry anthocyanins are also added. The weight ratio of the added blueberry anthocyanins to the nanocellulose is (0.2-0.28):

1.

5. The high-flexibility UV offset printing ink according to claim 1, characterized in that: The initiator is one or more of photoinitiator 379, photoinitiator DETX, and photoinitiator 184.

6. The high-flexibility UV offset printing ink according to claim 1, characterized in that: The filler is one or both of magnesium carbonate and solid paraffin.

7. A method for preparing a high-flexibility UV offset printing ink according to any one of claims 1-6, characterized in that, Includes the following steps: The modified polyester acrylic resin, toughening composition, monomer, pigment, initiator, co-initiator, and filler are dispersed to obtain the final product.

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