Environment-friendly plant oil-based offset printing ink and preparation method thereof

Abstract

According to the environment-friendly vegetable oil-based offset printing ink and the preparation method thereof, the used compound homogeneous vegetable oil has the advantages of being good in stability and capable of enhancing the viscoelasticity of a connecting material, and the compound use also has higher cost performance; the environment-friendly additive also has obvious influence on the adhesion and adhesive force of the ink; the oxidized polyethlene wax can reduce the content of volatile small molecular substances and reduce unpleasant odor; especially in the aspect of degradation rate, due to the addition of the degradable manganese-based environment-friendly carbon powder, an adsorption synergistic effect is achieved, and good reaction active sites can be provided for adsorption and degradation, so that the peculiar smell adsorption effect can be enhanced, and the degradation efficiency can be improved. The comprehensive performance of the offset printing ink prepared by adopting the preparation process disclosed by the invention is remarkably improved, and the offset printing ink has the advantages of excellent wear resistance, strong adhesive force, no peculiar smell, obvious degradation rate and good adaptability.

Description

Technical Field

[0001] The invention relates to the technical field of offset printing ink, and in particular to an environmentally friendly vegetable oil-based offset printing ink and a preparation method thereof. Background Art

[0002] Offset printing ink, also known as offset printing ink, includes offset resin ink, offset glossy ink, offset four-color ink, offset fast-setting ink, offset glossy quick-drying ink, offset sheetfed ink, offset rotary news ink, offset rotary thermosetting ink, offset iron ink, offset iron resistant cooking ink, offset plastic ink, offset light-curing ink, etc.

[0003] Generally, traditional offset ink contains a large amount of VOC (volatile organic compounds). Modern medicine has proven that many components in VOC are carcinogenic. At the same time, the additives in offset ink contain some aromatic hydrocarbons, which have also been proven to be carcinogenic. Moreover, my country's printing industry is currently facing great environmental pressure. Since most of the inks used in printing contain organic solvents (compared with solvent-based inks, there are very few organic solvents in offset inks), the volatilization and emission of organic solvents will cause environmental pollution. In addition, the ink contains harmful heavy metal elements such as lead, chromium, cadmium, mercury, arsenic, and barium, which are extremely harmful to the human body and the environment. Compared with developed regions in the world, there is still a big gap in the environmental protection of printing inks in my country.

[0004] Based on the advanced green environmental protection concept, low-halogen offset printing ink is refined from pure vegetable oil, contains almost no volatile components such as mineral oil, and meets the low-halogen solvent-free and aromatic-free standards and meets the European control requirements for mineral oil (MOSH & MOAH) in ink. However, in the process of bringing this ink to the market, the performance of VOC-free ink still has many defects:

[0005] 1. There are many additives in printing ink, which affects the degradation;

[0006] 2. Poor printing quality and poor adaptability.

[0007] 3. Traditional pure soybean oil is expensive, environmentally unfriendly, and not cost-effective.

[0008] In view of this, we disclose an environmentally friendly vegetable oil-based offset printing ink. Summary of the invention

[0009] In view of the deficiencies of the prior art, the present invention aims to provide an environmentally friendly vegetable oil-based offset printing ink.

[0010] To achieve the above object, the present invention proposes the following technical solutions:

[0011] A method for preparing an environmentally friendly vegetable oil-based offset printing ink comprises the following steps, measured in parts by weight:

[0012] 1) Connecting material section

[0013] First, 12-40 parts of soybean oil, 9-30 parts of vegetable oil, 9-30 parts of palm oil and its esters, and 3-10 parts of linseed oil are stirred and mixed evenly for 2-3 hours to obtain homogeneous vegetable oil; then 25-35 parts of rosin modified resin are added, stirring is continued at the same stirring speed, and the mixture is put into a mixing kettle and heated to 150° C. to dissolve to prepare a binder for batching;

[0014] 2) Batching section

[0015] The above ingredients are put into a mixing kettle with a connecting material, 5-10 parts of oxidized polyethylene wax, 1-5 parts of environmental protection additives, and 1-3 parts of fillers, and stirred evenly to prepare a crude ink product;

[0016] 3) Bead milling section

[0017] The ink crude product in the mixing kettle is dispersed in a bead mill at a temperature of 50-80°C and the fineness is bead-milled to less than 8.5 microns to obtain the ink semi-finished product, which enters the ink pressing section;

[0018] 4) Ink rolling section

[0019] Pour the semi-finished ink dispersed by the bead mill into a three-roll mill and grind it to a fineness of less than 7.5 microns to obtain a semi-finished ink;

[0020] 5) Color adjustment and inspection section

[0021] Add 10-15 parts of pigment to the semi-finished ink, adjust the index on the mixer, and make the ink into qualified products;

[0022] 6) Packaging section

[0023] The qualified ink products are filled, labeled, packed and packaged to make marketable commercial ink.

[0024] The environmental protection additive comprises a polyvinyl alcohol-polylactic acid graft copolymer, a gelling agent and a defoaming agent, and the mass ratio is 5:1:1. The preparation method of the polyvinyl alcohol-polylactic acid graft copolymer is:

[0025] Add lactic acid to deionized water, stir at 40°C for 0.5 hour, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep stirring at 90-105°C for 0.5-2 hours, then add soybean oil of the same specification, cool to 70-75°C, stir for 0.5-1 hour, filter while hot, wash the obtained solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer;

[0026] The molecular weight of the polyvinyl alcohol is 20000-50000, and the alcoholysis degree is 78%; the molecular weight of the polylactic acid is 25000-35000.

[0027] On the basis of the above scheme and as a preferred scheme of the above scheme, the homogenized vegetable oil is obtained by mixing soybean oil, vegetable oil, palm oil and its esters, and linseed oil in a mass ratio of 4:3:3:1 after undergoing a deodorization process.

[0028] On the basis of the above scheme and as a preferred scheme of the above scheme, the palm oil and its esters are formed by uniformly mixing palm oil and isooctyl palmitoleate in a mass ratio of 5:29.

[0029] On the basis of the above scheme and as a preferred scheme of the above scheme, the stirring speed of the connecting material section is 350rpm-1000rpm.

[0030] On the basis of the above scheme and as a preferred scheme of the above scheme, the filler is degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil.

[0031] On the basis of the above scheme and as a preferred scheme of the above scheme, the temperature of the ink rolling section is up to 40°C.

[0032] On the basis of the above scheme and as a preferred scheme of the above scheme, the pigment is one or more of yellow pigment, red pigment, blue pigment and black pigment.

[0033] On the basis of the above scheme and as a preferred scheme of the above scheme, the yellow pigment is one of Pigment Yellow 13 and Pigment Yellow 17 or a mixture thereof; the red pigment is one of Magenta 6B and Magenta 8B or a mixture thereof; the blue pigment is one of Phthalocyanine Blue BGS and Phthalocyanine Blue B or a mixture thereof; the black pigment is medium pigment carbon black.

[0034] On the basis of the above scheme and as a preferred scheme of the above scheme, it also includes offset printing ink prepared by adopting the preparation method of the environmentally friendly vegetable oil-based offset printing ink.

[0035] Among them, rosin modified resin is a rosin product obtained by changing the physical and chemical properties of rosin through physical or chemical reactions, collectively referred to as rosin modified resin or modified rosin resin. Preferably, the present invention uses rosin modified phenolic resin to play the role of a binder in offset printing ink, which can improve the viscosity, oil solubility and drying properties of offset printing ink, and improve the adhesion, fastness, wear resistance, water resistance and other properties of offset printing ink. If there is a lack of rosin modified resin in the offset printing ink, it will cause problems such as extremely poor printability, dull and blurred ink marks on the printed product.

[0036] Vegetable oil: Vegetable oil only plays a bridging role and plays a role in regulating balance, which is beneficial to improving the quality of offset printing ink.

[0037] Pigment: plays a role in color development and controls the hue of ink.

[0038] Oxidized polyethylene wax: Generally, in order to increase the wear resistance of offset ink and prevent back sticking, polyethylene wax is added as an anti-friction agent. However, direct use of polyethylene wax is prone to produce a certain amount of volatile small molecules in the high temperature process. These small molecules often have an unpleasant odor, which brings an unpleasant odor to the offset ink. The use of oxidized polyethylene wax can reduce the content of volatile small molecules. At the same time, the oxidation process can destroy the unstable structure on the polyethylene chain and reduce the possibility of producing volatile small molecules.

[0039] Vinyl alcohol-polylactic acid graft copolymer: It can accelerate the dispersion and adhesion of raw materials and speed up the film-forming rate of ink. The use of vinyl alcohol-polylactic acid graft copolymer together with defoaming agent and gelling agent can enhance the stability of ink film and extend the service life of ink.

[0040] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0041] The present invention discloses an environmentally friendly vegetable oil-based offset printing ink and a preparation method thereof. The compound homogeneous vegetable oil used has the advantages of good stability and can enhance the viscoelasticity of the connecting material, and the compound use also has a higher cost performance; the environmentally friendly additive also has a significant effect on the adhesion and adhesion of the ink; the oxidized polyethylene wax can reduce the content of volatile small molecules therein and reduce unpleasant odors; especially in terms of degradation rate, due to the addition of degradable manganese-based environmentally friendly carbon powder, it has an adsorption synergistic effect, can provide good reactive sites for adsorption and degradation, and can further enhance the odor adsorption effect and improve the degradation efficiency. The comprehensive performance of the offset printing ink prepared by the preparation process of the present invention is significantly improved, and has the advantages of excellent wear resistance, strong adhesion, no odor, obvious degradation rate, and good adaptability.

[0042] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, may be considered part of the present subject matter disclosure to the extent such concepts are not mutually inconsistent.

[0043] The foregoing and other aspects, embodiments and features of the present invention will be more fully understood from the following description. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or will be learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0045] Figure 1 It is a preparation process flow chart of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme 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 part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0047] The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular form of "a", "an" or "the" and other similar words do not indicate a quantitative limitation, but indicate the existence of at least one. "Include" or "comprise" and other similar words mean that the elements or objects appearing before "include" or "comprise" cover the features, wholes, steps, operations, elements and / or components listed after "include" or "comprise", and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0048] Traditional mineral oil system solvents contain volatile aromatic substances, which will release a large amount of volatile organic substances into the environment when refined at high temperatures. In order to seize the market of environmentally friendly inks, mainstream ink manufacturers in various countries around the world have increased their research and development efforts on environmentally friendly inks and have successively launched their own environmentally friendly products. At present, most of the existing environmentally friendly products in my country's ink industry are low aromatic inks and soybean oil inks. In addition, most of the soybean oil inks provided by domestic ink manufacturers are only suitable for printing on certain specific papers. For papers with poor absorbency and rough surfaces, there are problems such as poor drying, easy sticking to the back, and easy dirt. The soybean oil molecule has a low content of double bonds and low reaction activity, and the oxidation reaction occurs slowly. In addition, its relative molecular mass and molecular volume are larger than those of mineral oil, and the penetration rate on paper is slow, resulting in problems such as poor ink drying.

[0049] In order to avoid quality defects caused by single vegetable oil in offset ink, we continue to use composite vegetable oil system for research. Soybean oil, vegetable oil, palm oil and its esters, linseed oil are deodorized and mixed in a mass ratio of 4:3:3:1 to form homogeneous vegetable oil. It not only helps to improve the adhesion of ink to the substrate, making the ink less likely to fall off and fade; it has good system compatibility and stability, as well as high viscoelasticity, taking into account both high gloss and viscosity stability.

[0050] In the present invention, the environmentally friendly additive includes polyvinyl alcohol-polylactic acid graft copolymer, gelling agent and defoaming agent, which can accelerate the dispersion and bonding of raw materials, accelerate the ink film forming rate, enhance the stability of the ink film, and extend the service life of the ink. The preparation method of the polyvinyl alcohol-polylactic acid graft copolymer is:

[0051] Add lactic acid to deionized water, stir at 40°C for 0.5 hours, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep warm at 90-105°C and stir for 0.5-2 hours, then add soybean oil of the same specification, cool to 70-75°C and stir for 0.5-1 hour, filter while hot, wash the solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer. The principle is: polyvinyl alcohol (EVOH) and poly L-lactic acid are mixed in the presence of an esterification catalyst, wherein the hydroxyl group of EVOH reacts with the carboxyl group at the end of the poly L-lactic acid molecule. This reaction directly uses the low molecular weight primary poly L-lactic acid obtained from the bulk polycondensation reaction of L-lactic acid. In this way, a graft copolymer with polyvinyl alcohol as the main chain and polylactic acid as the side chain can be obtained. The mechanical properties of this graft copolymer are better than those of a simple mixture, and it shows excellent levels of biodegradability.

[0052] Furthermore, the filler is a degradable manganese-based environmentally friendly carbon powder, which is prepared using fir waste as raw material. The specific preparation method is as follows:

[0053] S1. First, place Chinese fir wood powder and phenol in a mass ratio of 1:6 in a three-necked flask and stir evenly at 60-80° C.; continue stirring, and at the same time, drop phosphoric acid solution at a dropping speed of 1 mL / min, with the drop amount being half the mass of the Chinese fir wood powder, to obtain a liquefied mixed solution;

[0054] S2. Add 10 wt% of hexamethylenetetramine to the liquefied mixed liquid, mix, and stir evenly for 4 hours at 85°C in the absence of oxygen. After natural cooling, add anhydrous ethanol to wash 2-3 times, and then centrifuge to obtain a solid substance, which is dried and set aside.

[0055] S3, prepare a mixed solution of 18.95% HCl and 18.95% methanol, and keep the temperature of the mixed solution at 60° C., soak the dried solid substance of S2 in the mixed solution for 1 hour, wash with deionized water, and dry at 80° C. for 12 hours to obtain a semi-finished product;

[0056] S4, placing the dried semi-finished product in a tubular furnace for activation carbonization, uniformly heating to 800°C at a heating rate of 5°C / min for activation carbonization, and maintaining an inert gas flow rate of 100 mL / min, keeping the temperature under a steam flow of 10 g / min for 1 hour, and cooling to 25°C to obtain a highly active carbonaceous material;

[0057] S5, placing potassium permanganate and highly active carbonaceous material in deionized water at a mass ratio of 40:100, wherein the volume of deionized water is 3 times the total volume of the material, and performing in-situ hydrothermal reaction at 80° C. for 6 hours, then washing with deionized water for multiple times, and drying at 80° C. to obtain manganese-based environmentally friendly carbon;

[0058] S6, mixing the hydroxycaproate solid with dichloromethane in a mass ratio of 1:10, stirring continuously until dissolved, and then purifying and precipitating using a rotary evaporator, using anhydrous ethanol as a solvent, and placing in a fume hood at room temperature to evaporate the solvent, to obtain purified hydroxycaproate;

[0059] S7. Weigh manganese-based environmentally friendly carbon and purified hydroxycaproate in a mass ratio of 10:1 respectively, and prepare a 10wt% dimethylformamide solution, mix the dimethylformamide solution of manganese-based environmentally friendly carbon and the dimethylformamide solution of purified hydroxycaproate, stir for 2 hours, disperse by ultrasound for 4 hours, and dry into thin slices on a 55°C heating plate. Cut the slices into pieces, grind them into powder, and sieve them with a 600-mesh sieve to obtain degradable manganese-based environmentally friendly carbon powder.

[0060] In step S5, a redox reaction occurs and manganese dioxide is produced, so that manganese dioxide is loaded on the carbon surface to form a cross-linked and intertwined pore structure. This structure is conducive to the adsorption synergy between manganese dioxide and carbon. Such a cross-linked and intertwined pore structure also has a layered characteristic, which can provide good reaction active sites for adsorption and degradation, thereby enhancing the odor adsorption effect and improving the degradation efficiency.

[0061] Moreover, in the comparative test of the connecting materials of pure soybean oil and rosin modified resin, compared with the ink without adding degradable manganese-based environmentally friendly carbon powder, the addition of degradable manganese-based environmentally friendly carbon powder can improve the anti-emulsification ability of the ink, effectively control the expansion of printing dots, increase the solid density, and overcome the disadvantages of poor fluidity, poor transferability, piling, greasiness, and floating dirt caused by severe emulsification.

[0062] Example 1

[0063] A method for preparing an environmentally friendly vegetable oil-based offset printing ink comprises the following steps, measured in parts by weight:

[0064] 1) Connecting material section

[0065] First, 24 parts of soybean oil, 18 parts of vegetable oil, 18 parts of palm oil and its esters, and 6 parts of linseed oil were stirred and mixed evenly for 2-3 hours to obtain homogeneous vegetable oil; then 30 parts of rosin modified resin were added, and the stirring was continued at the same stirring speed (650rpm), and the mixture was put into a mixing kettle and heated to 150°C to dissolve to prepare a binder for batching;

[0066] The palm oil and its esters are prepared by uniformly mixing palm oil and isooctyl palmitoleate in a mass ratio of 5:29.

[0067] 2) Batching section

[0068] The above ingredients are put into a mixing kettle with a connecting material, 7 parts of oxidized polyethylene wax, 3 parts of environmental protection additives, and 2 parts of fillers, and stirred evenly to prepare a crude ink product;

[0069] The filler is degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil.

[0070] 3) Bead milling section

[0071] The ink crude product in the mixing kettle is dispersed in a bead mill at a temperature of 65°C and the fineness is bead-milled to less than 8.5 microns to obtain the ink semi-finished product, which enters the ink pressing section;

[0072] 4) Ink rolling section

[0073] Pour the semi-finished ink dispersed by the bead mill into a three-roll mill and grind it to a fineness of less than 7.5 microns to obtain a semi-finished ink;

[0074] 5) Color adjustment and inspection section

[0075] 13 parts of pigment are added to the semi-finished ink, and the indicators are adjusted on a mixer to make a qualified ink; the pigment is a mixture of yellow pigment, red pigment, blue pigment and black pigment, the yellow pigment is pigment yellow 13; the red pigment is magenta 6B; the blue pigment is phthalocyanine blue BGS; the black pigment is medium pigment carbon black.

[0076] 6) Packaging section

[0077] The qualified ink products are filled, labeled, boxed and packaged to make marketable commercial ink, that is, the environmentally friendly vegetable oil-based offset printing ink of this embodiment is obtained.

[0078] Furthermore, the environmental protection additive includes polyvinyl alcohol-polylactic acid graft copolymer, gelling agent and defoaming agent, and the mass ratio is 5:1:1. The preparation method of polyvinyl alcohol-polylactic acid graft copolymer is:

[0079] Add lactic acid to deionized water, stir at 40°C for 0.5 hour, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep stirring at 100°C for 1 hour, then add soybean oil of the same specification, cool to 75°C and stir for 0.5 hour, filter while hot, wash the obtained solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer;

[0080] The molecular weight of the polyvinyl alcohol is 30,000, and the alcoholysis degree is 78%; the molecular weight of the polylactic acid is 28,000.

[0081] Example 2

[0082] Different from the above-mentioned embodiment 1, a method for preparing an environmentally friendly vegetable oil-based offset printing ink comprises the following steps, measured in parts by weight:

[0083] 1) Connecting material section

[0084] First, 12 parts of soybean oil, 9 parts of vegetable oil, 9 parts of palm oil and its esters, and 3 parts of linseed oil were stirred and mixed at a stirring speed of 350 rpm for 2 hours to obtain homogeneous vegetable oil; then 25 parts of rosin modified resin were added, and the stirring was continued at the same stirring speed, and the mixture was put into a mixing kettle and heated to 150°C to dissolve to prepare a binder for batching;

[0085] Among them, the homogeneous vegetable oil is prepared by mixing soybean oil, vegetable oil, palm oil and its esters, and linseed oil in a mass ratio of 4:3:3:1 after deodorization; the palm oil and its esters are prepared by uniformly mixing palm oil and isooctyl palmitoleate in a mass ratio of 5:29.

[0086] 2) Batching section

[0087] The above ingredients are put into a mixing kettle with a connecting material, 5 parts of oxidized polyethylene wax, 1 part of an environmental protection additive, and 1 part of a filler, and stirred evenly to prepare a crude ink product;

[0088] The filler is degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil.

[0089] 3) Bead milling section

[0090] The ink crude product in the mixing kettle is dispersed in a bead mill at a temperature of 50°C and the fineness is bead-milled to less than 8.5 microns to obtain the ink semi-finished product, which enters the ink pressing section;

[0091] 4) Ink rolling section

[0092] Pour the semi-finished ink dispersed by the bead mill into a three-roll mill and grind it to a fineness of less than 7.5 microns to obtain a semi-finished ink;

[0093] 5) Color adjustment and inspection section

[0094] 10 parts of pigment are added to the semi-finished ink, and the indexes are adjusted on a mixer to produce a qualified ink; the pigment is a black pigment, a medium-pigment carbon black.

[0095] 6) Packaging section

[0096] The qualified ink products are filled, labeled, boxed and packaged to make marketable commercial ink, that is, the environmentally friendly vegetable oil-based offset printing ink of this embodiment is obtained.

[0097] Furthermore, the environmental protection additive includes polyvinyl alcohol-polylactic acid graft copolymer, gelling agent and defoaming agent, and the mass ratio is 5:1:1. The preparation method of polyvinyl alcohol-polylactic acid graft copolymer is:

[0098] Add lactic acid to deionized water, stir at 40°C for 0.5 hour, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep stirring at 90°C for 0.5 hour, then add soybean oil of the same specification, cool to 70°C and stir for 0.5 hour, filter while hot, wash the obtained solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer;

[0099] The molecular weight of the polyvinyl alcohol is 20,000, and the alcoholysis degree is 78%; the molecular weight of the polylactic acid is 25,000.

[0100] Example 3

[0101] Different from the above-mentioned embodiment 1, a method for preparing an environmentally friendly vegetable oil-based offset printing ink comprises the following steps, measured in parts by weight:

[0102] 1) Connecting material section

[0103] First, 40 parts of soybean oil, 30 parts of vegetable oil, 30 parts of palm oil and its esters, and 10 parts of linseed oil are stirred and mixed at a stirring speed of 1000 rpm for 2-3 hours to obtain homogeneous vegetable oil; then 25-35 parts of rosin modified resin are added, stirring is continued at the same stirring speed, and the mixture is put into a mixing kettle and heated to 150°C to dissolve to prepare a binder for batching;

[0104] Among them, the homogeneous vegetable oil is prepared by mixing soybean oil, vegetable oil, palm oil and its esters, and linseed oil in a mass ratio of 4:3:3:1 after deodorization; the palm oil and its esters are prepared by uniformly mixing palm oil and isooctyl palmitoleate in a mass ratio of 5:29.

[0105] 2) Batching section

[0106] The above ingredients are put into a mixing kettle with a connecting material, 10 parts of oxidized polyethylene wax, 5 parts of environmental protection additives, and 3 parts of fillers, and stirred evenly to prepare a crude ink product; the filler is degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil.

[0107] 3) Bead milling section

[0108] The ink crude product in the mixing kettle is dispersed in a bead mill at a temperature of 80°C and the fineness is bead-milled to less than 8.5 microns to obtain the ink semi-finished product, which enters the ink pressing section;

[0109] 4) Ink rolling section

[0110] Pour the semi-finished ink dispersed by the bead mill into a three-roll mill and grind it to a fineness of less than 7.5 microns to obtain a semi-finished ink;

[0111] 5) Color adjustment and inspection section

[0112] Add 15 parts of pigment to the semi-finished ink, adjust the index on the mixer, and make the qualified ink; the pigment is a mixture of yellow pigment, red pigment and blue pigment. The yellow pigment is pigment yellow 17; the red pigment is magenta 8B; the blue pigment is a mixture of phthalocyanine blue BGS and phthalocyanine blue B.

[0113] 6) Packaging section

[0114] The qualified ink products are filled, labeled, boxed and packaged to make marketable commercial ink, that is, the environmentally friendly vegetable oil-based offset printing ink of this embodiment is obtained.

[0115] Furthermore, the environmental protection additive includes polyvinyl alcohol-polylactic acid graft copolymer, gelling agent and defoaming agent, and the mass ratio is 5:1:1. The preparation method of polyvinyl alcohol-polylactic acid graft copolymer is:

[0116] Add lactic acid to deionized water, stir at 40°C for 0.5 hour, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep stirring at 105°C for 2 hours, then add soybean oil of the same specification, cool to 75°C and stir for 1 hour, filter while hot, wash the obtained solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer;

[0117] The molecular weight of the polyvinyl alcohol is 50,000, and the alcoholysis degree is 78%; the molecular weight of the polylactic acid is 35,000.

[0118] Comparative Example 1

[0119] The difference from Example 1 is that in the connecting material section, 48 parts of soybean oil and 18 parts of vegetable oil are directly taken and stirred and mixed evenly, and stirred for 2-3 hours to obtain homogeneous vegetable oil; other processes and parameters refer to Example 1.

[0120] Comparative Example 2

[0121] Different from Example 1, in the batching section, the batching connecting material, 7 parts of oxidized polyethylene wax, and 2 parts of filler are put into a mixing kettle and stirred evenly to prepare a crude ink product; the filler is a degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil. Other processes and parameters refer to Example 1.

[0122] Comparative Example 3

[0123] Different from Example 1, in the batching section, the batching connecting material, 3 parts of environmental protection additives, and 2 parts of fillers are put into a mixing kettle and stirred evenly to prepare a crude ink product; the filler is a degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil. Other processes and parameters refer to Example 1.

[0124] Comparative Example 4

[0125] Different from Example 1, in the batching section, the batching connecting material, 7 parts of oxidized polyethylene wax, 3 parts of environmental protection additives, and 2 parts of fillers are put into a mixing kettle and stirred evenly to prepare a crude ink product; the filler is ordinary carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil. Other processes and parameters refer to Example 1.

[0126] Comparative Example 4

[0127] Purchase commercially available ordinary environmentally friendly offset printing inks and conduct relevant performance tests.

[0128] Performance Testing

[0129] Viscoelastic properties test of connecting materials for batching

[0130] Viscoelasticity: tan(ζ) was tested using the HAKKE RheoStress RS6000 instrument and the HAKKE Rheowin3 software standard. Theoretically, when f=1, tan(ζ) indicates that the elasticity of the ink is higher.

[0131] Ink physical properties

[0132] At room temperature (25±0.5)℃ and relative humidity RH (65±5)%, the following data were tested:

[0133] Printing density: The amount of light or reflectivity reflected from the test surface is measured using a reflection densitometer. The larger the value, the higher the ink printing density, which means the better the transfer ability of the same amount of ink;

[0134] Ink flying: Ink flying refers to the observation of the dispersion of ink from the ink roller during printing, and the ink sticking to the white paper on the ink surface beam. The ink flying situation can represent the tightness of the internal structure of the ink itself during high-speed operation. The tighter the structure, the less likely it is to fly.

[0135] Abrasion resistance

[0136] The friction resistance of ink includes vibration type friction resistance, swing type friction resistance and vibration type friction resistance. The test standards and judgments are as follows:

[0137] The Gakushin type abrasion resistance (up and down swing) is measured by a JIS Gakushin type abrasion resistance tester. The test condition is: 500g / 10 back and forth. The result is judged as follows: (poor) 1-3-5 (excellent) level values ​​represent the level from poor to excellent.

[0138] The swinging abrasion resistance (left and right swinging) is measured by a swinging abrasion resistance tester. The test conditions are: 4 pounds / 50 back and forth. The result is judged as follows: (poor) 1-3-5 (excellent) level values ​​represent the level from poor to excellent.

[0139] The vibration type abrasion resistance is measured by a vibration type abrasion resistance tester, and the result is judged as follows: the grade values ​​of (poor) 1-3-5 (excellent) represent the grade levels from poor to excellent.

[0140] Tinting Strength

[0141] GB / T 13217.1-2020 "Test method for ink color and tinting strength" is adopted.

[0142] Adhesion

[0143] Adhesion is achieved by using 0.075cc / 230cm 2 The amount of ink was proofed on white cardboard. After 24 hours, 3M tape was used to stick and tear off the tape, and the ink adhered to the tape was observed. The results were judged as follows: (poor) 1-3-5 (excellent) The grade values ​​represent the grade from poor to excellent.

[0144] Odor and degradation rate

[0145] The ink odor is rated using the method described in GB / T 35773-2017 “Evaluation of odor of packaging materials and products”;

[0146] The ink was printed on a PET plate to form a film. After it was completely dried, it was placed in the same test soil and buried for 15 days, and the degradation rate was calculated.

[0147] The samples prepared in the above Examples 1-3 and Comparative Examples 1-5 were sampled and tested and evaluated according to the above performance test. The results are shown in Table 1 below.

[0148] Table 1 Performance test comparison results

[0149] It can be seen from the test data in Table 1 that, compared with the common offset ink of the prior art, the comprehensive performance of the offset ink prepared by the preparation process of the present invention is significantly improved, and it has the advantages of excellent wear resistance, strong adhesion, no odor, obvious degradation rate, and good adaptability. When the compound environmental protection additive of the present invention is used, it has a significant effect on the adhesion and adhesion of the ink; the use of oxidized polyethylene wax can reduce the possibility of volatile unpleasant small molecule odors caused by the addition of wear-resistant materials; especially in terms of degradation rate, due to the addition of degradable manganese-based environmentally friendly carbon powder, the material structure has an adsorption synergistic effect, which can provide good reaction active sites for adsorption and degradation, thereby enhancing the odor adsorption effect and improving the degradation efficiency.

[0150] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for preparing an environmentally friendly vegetable oil-based offset printing ink, characterized in that: The method comprises the following steps, in parts by weight: 1) Connecting material section First, 12-40 parts of soybean oil, 9-30 parts of vegetable oil, 9-30 parts of palm oil and its esters, and 3-10 parts of linseed oil are stirred and mixed evenly for 2-3 hours to obtain homogeneous vegetable oil; then 25-35 parts of rosin modified resin are added, stirring is continued at the same stirring speed, and the mixture is put into a mixing kettle and heated to 150° C. to dissolve to prepare a binder for batching; 2) Batching section The above ingredients are put into a mixing kettle with a connecting material, 5-10 parts of oxidized polyethylene wax, 1-5 parts of environmental protection additives, and 1-3 parts of fillers, and stirred evenly to prepare a crude ink product; 3) Bead milling section The ink crude product in the mixing kettle is dispersed in a bead mill at a temperature of 50-80°C and the fineness is bead-milled to less than 8.5 microns to obtain the ink semi-finished product, which enters the ink pressing section; 4) Ink rolling section Pour the semi-finished ink dispersed by the bead mill into a three-roll mill and grind it to a fineness of less than 7.5 microns to obtain a semi-finished ink; 5) Color adjustment and inspection section Add 10-15 parts of pigment to the semi-finished ink, adjust the index on the mixer, and make the ink into qualified products; 6) Packaging section The qualified ink products are filled, labeled, packed and packaged to make marketable commercial ink.

2. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 1, characterized in that: The environmental protection auxiliary agent includes polyvinyl alcohol-polylactic acid graft copolymer, gelling agent and defoaming agent, and the mass ratio is 5:1:

1.

3. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 2, characterized in that: The preparation method of polyvinyl alcohol-polylactic acid graft copolymer is: Add lactic acid to deionized water, stir at 40°C for 0.5 hour, then add polyvinyl alcohol and stannous octoate, heat to reflux under nitrogen protection, keep stirring at 90-105°C for 0.5-2 hours, then add soybean oil of the same specification, cool to 70-75°C, stir for 0.5-1 hour, filter while hot, wash the obtained solid with deionized water to remove impurities, and vacuum dry at 50°C to constant weight to obtain polyvinyl alcohol-polylactic acid graft copolymer; The molecular weight of the polyvinyl alcohol is 20000-50000, and the alcoholysis degree is 78%; the molecular weight of the polylactic acid is 25000-35000.

4. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 3, characterized in that: The homogenized vegetable oil is prepared by mixing soybean oil, vegetable oil, palm oil and its esters, and linseed oil in a mass ratio of 4:3:3:1 after undergoing a deodorization process.

5. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 4, characterized in that: The palm oil and its esters are prepared by uniformly mixing palm oil and isooctyl palmitoleate in a mass ratio of 5:

29.

6. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 3, characterized in that: The stirring speed of the connecting material section is 350rpm-1000rpm; The highest temperature in the ink rolling section is 40°C.

7. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 3, characterized in that: The filler is degradable manganese-based environmentally friendly carbon powder, the gelling agent is distearate, and the defoaming agent is methyl silicone oil.

8. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 3, characterized in that: The pigment is one or more of yellow pigment, red pigment, blue pigment and black pigment.

9. The method for preparing an environmentally friendly vegetable oil-based offset printing ink according to claim 8, characterized in that: The yellow pigment is one of Pigment Yellow 13 and Pigment Yellow 17 or a mixture thereof; the red pigment is one of Magenta 6B and Magenta 8B or a mixture thereof; the blue pigment is one of Phthalocyanine Blue BGS and Phthalocyanine Blue B or a mixture thereof; the black pigment is medium pigment carbon black.

10. An environmentally friendly vegetable oil-based offset printing ink, characterized in that: The method is prepared by any one of claims 1 to 9.

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