CN106833117B - Solvent-free epoxy ink and preparation process thereof - Google Patents

Abstract

The invention discloses a solvent-free epoxy ink and a preparation process thereof, and the technical scheme is characterized in that the solvent-free epoxy ink is composed of the following components, by mass, 50-70 parts of liquid epoxy with a solid content of 100%, 10-15 parts of amino resin with a solid content of 100%, 30-45 parts of inorganic pigment or 8-15 parts of organic pigment, 1-2 parts of active diluent, 1-2 parts of anti-settling agent, 1-2 parts of defoaming agent, 1-2 parts of dispersing agent and 1-2 parts of flatting agent, and is obtained by grinding after high-speed dispersion.

Description

Solvent-free epoxy ink and preparation process thereof

Technical Field

The invention relates to solvent-free ink, in particular to solvent-free epoxy ink and a preparation process thereof.

Background

Ink is an important material for printing, and is used for expressing patterns and characters on a printing material through printing or inkjet. The general ink is composed of binder (resin), pigment, filler, assistant and solvent, and can be used for various printings such as books, packaging decoration, building decoration and electronic circuit boards. As social demands increase, ink varieties and yields also expand and grow accordingly.

With the enhancement of environmental protection awareness of people in China, particularly in the food packaging industry, the requirement for printing by environment-friendly ink is gradually growing. Therefore, according to the market requirements, the development of nontoxic and pollution-free environment-friendly ink is actively put into the ink manufacturing industry in China, and the solvent-free ink is gradually popularized in the printing industry as the environment-friendly ink.

The epoxy solvent-free paint disclosed in the publication No. CN101747822A comprises the following components in parts by weight: 30-45 parts of epoxy resin, 10-20 parts of curing agent, 30-45 parts of inert pigment and filler and 5-10 parts of additive. The coating has the characteristics of environmental protection and safe use, and has outstanding antifouling and anticorrosion performances, but the prepared coating has certain defects in performance due to large brittleness and poor impact toughness after the epoxy resin is cured.

Disclosure of Invention

The first purpose of the invention is to provide the solvent-free epoxy ink with high hardness and good glossiness.

The technical purpose of the invention is realized by the following technical scheme:

the solvent-free epoxy ink comprises the following components in parts by mass: 50-70 parts of liquid epoxy with 100% solid content, 10-15 parts of amino resin with 100% solid content, 30-45 parts of inorganic pigment or 8-15 parts of organic pigment, 1-2 parts of reactive diluent, 1-2 parts of anti-settling agent, 1-2 parts of defoaming agent, 1-2 parts of dispersing agent and 1-2 parts of flatting agent.

By adopting the technical scheme, the epoxy resin in the liquid epoxy with the solid content of 100% is used as the most widely applied film-forming resin, the cured product has the characteristics of excellent mechanical property, strong adhesive force, small curing shrinkage, excellent electrical insulation and good stability, and through the addition of the amino resin with the solid content of 100%, the amino resin is used as a cross-linking agent to enhance the toughness of the epoxy during curing, so that the gloss, color retention, hardness, chemical resistance, water resistance and weather resistance of the ink are improved; the addition of organic pigments or inorganic pigments, the former having bright hue, strong tinting strength and short drying time, such as azo pigments and phthalocyanine pigments; the pigment has good light resistance, heat resistance, solvent resistance and hiding power, such as titanium white, cadmium red, chromium green, ultramarine and the like, is colored in a micro-particle state, is not dissolved, can provide different colors and color concentrations for the ink, and ensures that the ink has certain viscosity and drying property; the reactive diluent can participate in the curing crosslinking reaction of the epoxy resin, can reduce the viscosity of the resin and improve the toughness of the ink after film formation; the solvent-free epoxy resin of the anti-settling agent is easy to precipitate, the storage stability of the ink is influenced, the storage of the ink can be stabilized by adding the anti-settling agent, and meanwhile, the sagging phenomenon is reduced; the main performance of the defoaming agent is to eliminate bubbles in the ink and prevent the problems of white spots, sand holes, water marks and the like caused by the bubbles during printing; the dispersant has special interfacial activity and can help pigment to wet and deflocculate, thereby greatly shortening the dispersion time. Can be adsorbed on the surface of the pigment to prevent coarse returning, so that the coating has good storage stability; the leveling agent can promote the ink to form a flat, smooth and uniform coating film in the drying film-forming process; the ink prepared by the formula is free of solvent addition, free of solvent volatilization in the ink film forming process, high in environmental protection degree, small in influence on human health, good in toughness and high in ink glossiness.

Preferably, the 100% solids liquid epoxy is bisphenol a and has an epoxy value of: 0.48 to 0.54 and a viscosity of 8 to 10 pas.

By adopting the technical scheme, hydroxyl and epoxy groups in the bisphenol A type can enable epoxy resin and adjacent interfaces to generate adsorption or chemical bonds, macromolecules with a three-dimensional net structure can be formed after the epoxy resin and the adjacent interfaces are cured, the adhesive property is particularly strong, the adhesive force is good, the molecules are closely arranged due to the association of hydrogen bonds in the curing process, the shrinkage rate is small, and the bisphenol A type epoxy resin has excellent chemical stability and excellent electrical insulation property.

Preferably, the amino resin with the solid content of 100% is methyl etherified melamine resin, and the viscosity of the amino resin is 26-50 Pa.s.

By adopting the technical scheme, the methyl etherified melamine resin can be used as an effective cross-linking agent of a hydroxyl, carboxyl and amino functional group polymer, the stability in a system is excellent, the printing ink has good hardness and flexibility after film forming, and the cross-linking performance with the epoxy resin is excellent.

Preferably, the reactive diluent is one of allyl glycidyl ether, ethylene glycol glycidyl ether, oxypropylene benzyl ether and allyl polyethylene glycol.

By adopting the technical scheme, the diluent has a good diluting effect, has a good toughening effect, contains epoxy groups, and can react with a curing agent to improve the curing amount.

Preferably, the anti-settling agent is one of fumed silica, quaternary ammonium salt modified bentonite and CTMAB modified bentonite.

By adopting the technical scheme, the silanol groups are arranged on the surfaces of the fumed silica, hydrogen bonds are formed between the adjacent fumed silica, the organically modified bentonite has good compatibility with the printing ink, the hydrogen bonds can be formed between the organically modified bentonite and the base material, the hydrogen bonds can endow the system with certain structural viscosity, the thickening effect can be achieved, the hydrogen bonds are damaged when the organic modified bentonite is subjected to shearing force, the strength of the printing ink is reduced, the organic modified bentonite is convenient to use, the hydrogen bonds can be formed again after the shearing force disappears, the viscosity is improved, the deposition is not easy to generate in the storage process, and the sagging phenomenon is obviously improved in the use process.

Preferably, the defoaming agent is one of polyether modified polysiloxane, epoxy modified polysiloxane, amino modified polysiloxane and alkyl modified polysiloxane.

By adopting the technical scheme, the organic modified polysiloxane has good compatibility with resin and foaming medium, good thermal stability and good foam inhibition effect at lower concentration.

Preferably, the dispersant is one of polyacrylic acid ammonium salt, polycarboxylic acid amine salt and polyvinylpyrrolidone.

By adopting the technical scheme, the dispersant has good compatibility with a system, not only can well play a role in wetting and dispersing, but also can improve the stability and water resistance of the system.

Preferably, the leveling agent is one of polyethylacrylate, organosilicon modified acrylate and pentaerythritol triacrylate.

By adopting the technical scheme, the acrylic leveling agent has good wettability, can provide leveling power for ink film forming, enables the surface of the ink to have right surface tension, and improves the surface leveling effect.

The second purpose of the invention is to provide a preparation process of the solvent-free epoxy ink, which improves the stability of the ink.

The technical purpose of the invention is realized by the following technical scheme:

a preparation method of solvent-free epoxy ink comprises the following steps:

(1) adding liquid epoxy with 100% solid content and an active diluent into a high-speed stirrer, and stirring for 5-8 min at 700-900 r/min;

(2) adding 100% solid content amino resin, organic pigment or inorganic pigment, anti-settling agent, partial defoaming agent, dispersing agent and leveling agent into the step (1), and continuously stirring for 25-35 min at 1200-1500 r/min;

(3) grinding the mixture by a three-roller machine until the fineness of the mixture reaches below 10 mu m, adding the rest defoaming agent, and stirring at a high speed of 700-900 r/min for 2-3 min to obtain the ink product.

By adopting the technical scheme, the liquid epoxy with 100% solid content and the reactive diluent are firstly stirred, so that the surface viscosity of the liquid epoxy and the reactive diluent is reduced, the energy consumption of a machine is reduced, the amino resin, the organic pigment or the inorganic pigment, the anti-settling agent, part of the defoaming agent, the dispersing agent and the flatting agent are added, so that the ink system has better crosslinking degree, the pigment can be uniformly dispersed in the system, the uniformity of the ink is improved after the pigment is ground, and the stability of the ink is improved after the residual defoaming agent is added.

Preferably, the temperature during stirring in the step (2) is controlled to be 70-80 ℃.

Through adopting above-mentioned technical scheme, under the state of high temperature, part low melting point organic matter volatilizees easily in the system, forms the volatile organic matter of micromolecule, influences the use of printing ink, makes the people harm healthily simultaneously, with temperature control below 80 ℃, can reduce the organic matter and volatilize, with temperature control more than 70 ℃, then can promote the effect of stirring, promote the efficiency of stirring.

In conclusion, the invention has the following beneficial effects:

the solvent-free epoxy ink is prepared by mixing liquid epoxy with 100% of solid content and amino resin serving as a cross-linking agent, can enhance the toughness of epoxy during curing and serve as a connecting material of a pigment, and can improve the gloss, color retention, hardness, chemical resistance, water resistance and weather resistance of the ink so that the pigment has better chromaticity; the addition of the anti-settling agent, part of the defoaming agent, the dispersing agent and the leveling agent improves the toughness of the ink after film formation, greatly shortens the dispersion time and ensures that the ink has good storage stability; the ink prepared by the formula is free of solvent addition, free of solvent volatilization in the ink film forming process, high in environmental protection degree, small in influence on human health, good in toughness and high in ink glossiness.

Detailed Description

The liquid epoxy with 100% solid content is selected from Taiwan south Asia F-51, the epoxy value is 0.51-0.54, and the viscosity is 8-10 pa.s.

CYMEL325 is selected as amino resin with 100% solid content, is methyl etherified high imino group melamine resin, and has the viscosity of 26-50 Pa.s.

Selecting allyl glycidyl ether as a reactive diluent A; selecting ethylene glycol glycidyl ether as a reactive diluent B; selecting the oxypropylene benzyl ether as a reactive diluent C; allyl polyethylene glycol was chosen as reactive diluent D.

Selecting fumed silica as an anti-settling agent A; selecting quaternary ammonium salt modified bentonite as an anti-settling agent B; and selecting the CTMAB modified bentonite as an anti-settling agent C.

Selecting polyether modified polysiloxane as a defoaming agent A; selecting epoxy modified polysiloxane as a defoaming agent B; selecting amino modified polysiloxane as a defoaming agent C; the alkyl-modified polysiloxane was selected as defoamer D.

Taking polyacrylic acid ammonium salt as a dispersant A; taking polycarboxylic amine salt as a dispersant B; polyvinylpyrrolidone was used as dispersant C.

Selecting polyethylacrylate as a leveling agent A; selecting organic silicon modified acrylate as a leveling agent B; pentaerythritol triacrylate was chosen as leveling agent C.

Example one

(1) 50 parts of liquid epoxy with 100% solid content and 1 part of reactive diluent A are added into a high-speed stirrer and stirred for 5min at the speed of 900 r/min;

(2) adding 10 parts of amino resin with solid content of 100%, 45 parts of zinc chrome yellow, 1 part of anti-settling agent A, 0.5 part of partial defoaming agent A, 1 part of dispersing agent A and 1 part of flatting agent A into the step (1), and continuously stirring at 1200r/min for 25min at 70 ℃;

(3) grinding the mixture by a three-roller machine until the fineness reaches below 15 mu m, adding 1 part of defoaming agent, and stirring at a high speed of 700r/min for 2min to obtain the ink product.

Example two

(1) Adding 70 parts of liquid epoxy with solid content of 100% and 2 parts of reactive diluent B into a high-speed stirrer, and stirring for 5min at a speed of 900 r/min;

(2) adding 15 parts of amino resin with solid content of 100%, 35 parts of zinc-titanium white, 2 parts of anti-settling agent B, 1.5 parts of partial defoaming agent B, 2 parts of dispersing agent B and 2 parts of flatting agent B into the step (1), and continuously stirring at 1500r/min for 35min at 70 ℃;

(3) grinding the mixture by a three-roller machine until the fineness reaches below 15 mu m, adding 0.5 part of defoaming agent B, and stirring at a high speed of 900r/min for 3min to obtain the ink product.

EXAMPLE III

(1) Adding 60 parts of liquid epoxy with solid content of 100% and 2 parts of reactive diluent C into a high-speed stirrer, and stirring for 5min at the speed of 800 r/min;

(2) adding 12 parts of amino resin with solid content of 100%, 10 parts of hansa yellow, 1 part of anti-settling agent C, 1 part of partial defoaming agent C, 1 part of dispersing agent C and 1 part of flatting agent C into the step (1), and continuously stirring at 1250r/min for 30min at 70 ℃;

(3) grinding the mixture by a three-roller machine until the fineness reaches below 15 mu m, adding 1 part of defoaming agent, and stirring at a high speed of 800r/min for 3min to obtain the ink product.

Example four

(1) Adding 55 parts of liquid epoxy with solid content of 100% and 1 part of reactive diluent D into a high-speed stirrer, and stirring for 4min at 850 r/min;

(2) adding 14 parts of amino resin with solid content of 100%, 15 parts of benzidine yellow, 2 parts of anti-settling agent B, 1 part of partial defoaming agent D, 2 parts of dispersing agent A and 1 part of flatting agent C into the step (1), and continuously stirring for 28min at 1350r/min at 80 ℃;

(3) grinding the mixture by a three-roller machine until the fineness of the mixture reaches below 15 mu m, adding 0.5 part of defoaming agent D, and stirring at a high speed of 800r/min for 3min to obtain the ink product.

EXAMPLE five

(1) Adding 65 parts of liquid epoxy with solid content of 100% and 1.5 parts of reactive diluent A into a high-speed stirrer, and stirring for 5min at 850 r/min;

(2) adding 15 parts of amino resin with solid content of 100%, 8 parts of phthalocyanyl blue, 1.5 parts of anti-settling agent B, 1.5 parts of partial defoaming agent C, 1 part of dispersing agent B and 1 part of flatting agent B into the step (1), and continuously stirring at 1400r/min for 32min at the temperature of 80 ℃;

(3) grinding the mixture by a three-roller machine until the fineness reaches below 15 mu m, adding 0.5 part of defoaming agent C, and stirring at a high speed of 750r/min for 3min to obtain the ink product.

EXAMPLE six

(1) Adding 60 parts of liquid epoxy with solid content of 100% and 2 parts of reactive diluent D into a high-speed stirrer, and stirring for 8min at 850 r/min;

(2) adding 15 parts of amino resin with solid content of 100%, 35 parts of zinc chrome yellow, 2 parts of anti-settling agent B, 1 part of partial defoaming agent C, 1 part of dispersing agent A and 1 part of flatting agent C into the step (1), and continuously stirring at 1300r/min for 30min at 75 ℃;

(3) grinding the mixture by a three-roller machine until the fineness reaches below 10 mu m, adding 1 part of defoaming agent C, and stirring at a high speed of 800r/min for 2min to obtain the ink product.

EXAMPLE seven

(1) 50 parts of liquid epoxy with solid content of 100 percent and 2 parts of reactive diluent D are added into a high-speed stirrer and stirred for 8min at the speed of 900 r/min;

(2) adding 15 parts of amino resin with solid content of 100%, 9 parts of benzidine yellow, 1 part of anti-settling agent C, 1.5 parts of partial defoaming agent D, 1 part of dispersing agent B and 1 part of flatting agent A into the step (1), and continuously stirring at 1400r/min for 30min at 75 ℃;

(3) grinding the mixture by a three-roller machine until the fineness of the mixture reaches below 15 mu m, adding 0.5 part of defoaming agent D, and stirring at a high speed of 850r/min for 3min to obtain the ink product.

7 sets of inks were prepared according to the above 7 sets of examples, and the following tests were performed by mixing the inks with a curing agent and coating the mixture on the surface of a substrate using a metal plate as a substrate;

(1) and (3) testing the adhesive force:

step1, dividing the coating area into small grids of 3x3mm by using an art knife;

step2, tightly adhering the 3M800 test adhesive tape to the test part to cover the whole test area;

step3, after waiting for 5min, tearing off the adhesive tape at an angle of 45 degrees with the plastic plate, and repeating for 3 times;

and step4, checking the deoiling area, taking the ratio of the deoiling area to the experimental area as a test result, and taking an average value to record.

(2) Alcohol resistance test:

step1, soaking white cotton cloth in industrial ethanol with the mass concentration of 98%, and wrapping the white cotton cloth with a 500g weight;

step2, fixing the plastic sheet on a wear-resistant testing machine with the side coated with the ink facing upwards;

step3, wiping the weight against the surface of the plastic sheet back and forth for 200 times;

step4, if the ink drop phenomenon occurs, stopping the experiment, if the ink drop phenomenon does not occur, continuing wiping, observing whether the ink drop phenomenon occurs or not every 20 times, stopping the experiment until the ink drop phenomenon occurs, and taking an average number to record;

and Step5, placing the plastic sheet with the ink loss phenomenon at 23 ℃ and 50% RH for 2h, observing whether the ink has color loss or cracks compared with the Step4, and recording the number of the plastic sheet with the color loss or cracks.

(3) And (3) testing pencil hardness:

step1, grinding the pen point of the 2H Chinese pencil to be flat, forming an oblique angle of 45 degrees with a plastic plate, and repeatedly pushing and scratching a 500g load weight for 200 times;

and Step2. after the pencil mark is wiped off by an eraser, observing whether the surface is scratched or not, scratching by using a plastic sheet, and recording the number of scratched sheets.

(4) Boiling resistance test:

step1, putting the plastic sheet into a beaker, completely immersing the plastic sheet in water in the beaker, wherein the water amount is 100mL, and heating in a water bath at 100 ℃ for 0.5h in a water bath;

taking out the mixture, and naturally cooling the mixture at 23 ℃ and 50% RH;

step3, observing whether the water body in the beaker changes color or not;

step4. plastic sheets were subjected to (1) adhesion test.

(5) And (3) testing acid resistance:

step1, preparing sulfuric acid with the mass concentration of 5%, and dripping for 8 hours on a printing surface at the speed of 5 s/dripping;

step2, washing, and naturally cooling at 23 ℃ and 50% RH;

step3, using a plastic sheet which has not been subjected to Step1 as a control group, observing whether or not fading occurs, and recording the fading amount;

step4. plastic sheets were subjected to (1) adhesion test.

(6) Alkali resistance test:

the test was carried out by replacing sulfuric acid having a mass concentration of 5% in the acid resistance test with sodium hydroxide having a mass concentration of 5%.

The test results are given in the following table:

in summary, the sixth embodiment is taken as the most preferred embodiment.

Comparative example 1

Comparative example one is an ink made in example six without the addition of 100% solids amino resin.

Comparative example No. two

Comparative example two is an ink made in example six without the addition of a reactive diluent.

Comparative example No. three

The third comparative example is the ink prepared in the sixth example without adding anti-settling agent.

Comparative example No. four

Comparative example four is an ink prepared in example six without the addition of a dispersant.

Comparative example five

Comparative example five is an ink made in example six without the addition of a defoamer.

Comparative example six

The sixth comparative example is the ink prepared in the sixth example without adding the leveling agent.

The test results are given in the following table:

the above table is integrated to show that the amino resin is added into a solvent-free epoxy system, so that the wear resistance, boiling resistance, alcohol resistance, acid resistance and alkali resistance of the epoxy ink can be greatly improved, and meanwhile, according to comparison of data of the sixth embodiment and the fifth embodiment, the defoaming agent amino modified polysiloxane in the formula has large influence on the alcohol resistance of the ink in the weight of the ink, and the ink prepared by the formula has the characteristic of no solvent, so that the solvent volatilization is avoided in the film forming process of the ink, the environmental protection degree is high, the influence on the human health is small, the toughness is good, the glossiness of the ink is high, and the adhesive force is good.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims (6)

1. The solvent-free epoxy ink is characterized by comprising the following components in parts by weight: 50-70 parts of liquid epoxy with 100% solid content, 10-15 parts of amino resin with 100% solid content, 30-45 parts of inorganic pigment or 8-15 parts of organic pigment, 1-2 parts of reactive diluent, 1-2 parts of anti-settling agent, 1-2 parts of defoaming agent, 1-2 parts of dispersing agent and 1-2 parts of flatting agent; the amino resin with the solid content of 100% is methyl etherified melamine resin, and the viscosity of the amino resin is 26-50 Pa.s; the active diluent is one of allyl glycidyl ether, ethylene glycol glycidyl ether, oxypropylene benzyl ether and allyl polyethylene glycol; the defoaming agent is one of polyether modified polysiloxane, epoxy modified polysiloxane, amino modified polysiloxane and alkyl modified polysiloxane; the liquid epoxy with 100% solid content is bisphenol A type, and the epoxy value is as follows: 0.48 to 0.54 and a viscosity of 8 to 10 pas.

2. The solventless epoxy ink according to claim 1 wherein the anti-settling agent is one of fumed silica, quaternary ammonium salt modified bentonite, and CTMAB modified bentonite.

3. The solventless epoxy ink according to claim 1 wherein the dispersant is one of an ammonium polyacrylate salt, an amine polycarboxylate salt, and polyvinylpyrrolidone.

4. The solvent-free epoxy ink as claimed in claim 1, wherein the leveling agent is one of polyethylacrylate, silicone-modified acrylate, pentaerythritol triacrylate.

5. A process for preparing a solventless epoxy ink according to any one of claims 1 to 4 comprising the steps of:

(1) adding liquid epoxy with 100% solid content and an active diluent into a high-speed stirrer, and stirring for 5-8 min at 700-900 r/min;

(2) adding 100% solid content amino resin, organic pigment or inorganic pigment, anti-settling agent, partial defoaming agent, dispersing agent and leveling agent into the step (1), and continuously stirring for 25-35 min at 1200-1500 r/min;

(3) grinding the mixture by a three-roller machine until the fineness of the mixture reaches below 10 mu m, adding the rest defoaming agent, and stirring at a high speed of 700-900 r/min for 2-3 min to obtain the ink product.

6. The method for preparing the solventless epoxy ink according to claim 5, wherein the temperature during the stirring in the step (2) is controlled to be 70-80 ℃.