WO2020244064A1 - Aqueous printing ink for plastic outer packaging and preparation method thereof - Google Patents

Abstract

Provided is an aqueous printing ink for plastic outer packaging, raw materials thereof are consists of an aqueous alkyd resin, a modified acrylic resin, ceramic powder, inorganic pigment, a leveling agent, a defoaming agent, and deionized water. The preparation method of the aqueous printing ink comprises the following steps of adding the aqueous alkyd resin and the modified acrylic resin into a stirrer to prepare a pre-mixture, preparing the ceramic powder and the inorganic pigment into mixed color paste, and finally mixing the pre-mixture and the mixed color paste in a reaction kettle together with the leveling agent and the defoaming agent, dispersing and grinding to obtain the finished ink.

Description

Aqueous printing ink for plastic outer packaging and preparation method thereof Technical field

The invention relates to the technical field of printing inks, in particular to a water-based printing ink for plastic outer packaging and a preparation method thereof.

Background technique

As we all know, traditional inks for plastic packaging are ketone-soluble. Although there are strict requirements for solvent residues, there are also problems such as health damage and solvent residues after printing that affect the safety of packaging products, especially food and medicine. . Benzene-soluble composite ink has been gradually unable to meet the requirements of my country's increasingly developed flexible packaging industry due to its large amount of aromatic hydrocarbons as solvents. For health and safety considerations and to adapt to increasingly stringent safety regulations, people urgently need environmentally friendly inks, that is, they hope not to add aromatic hydrocarbon solvents such as toluene and xylene in printing inks and during the use of inks. Therefore, it will become an inevitable trend to actively develop and apply green gravure inks and water-based inks that meet environmental protection requirements.

Water is not only non-toxic and harmless, and environmentally friendly, it is also an essential substance for human survival. Using water as the main solvent has extremely low organic solvent volatilization during ink production and printing, and the product is more stable than solvent-based, while protecting the health of front-line employees. Since water cannot burn, there is no fire hazard in the production and use of water-based inks. In food packaging and medical packaging, packaging materials are in direct contact with food or drugs, and the requirements for packaging raw materials are not only contained and sealed, but also reflected in the assurance of the hygiene and safety of food and drugs. With its zero pollution and extremely low VOC emissions, water-based inks play a vital role in the safety and reliability of packaging materials. However, when water-based inks are used for plastic packaging printing, they often have defects such as insufficient adhesion fastness and poor coloring power, which have an adverse effect on the further promotion and application of water-based inks.

Summary of the invention

Based on the problem that the current water-based printing ink cannot meet the needs of consumers in terms of performance, the present invention provides a water-based printing ink for plastic outer packaging and a preparation method thereof.

A water-based printing ink for plastic outer packaging, composed of the following raw materials in weight percentage:

Water-based alkyd resin 30～50%

Modified acrylic resin 15～25%

Ceramic powder 3～5%

Inorganic pigment 2.5～4.5%

Leveling agent 0.5～1.5%

Antifoaming agent 0.5～1.5%

Deionized water balance;

Wherein, the preparation method of the modified acrylic resin is: in a reaction kettle, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate uniformly, and heat the reaction kettle until the temperature reaches 65-70°C Incubate and stir for 35-45 minutes, then increase the temperature to 85-88°C, add an appropriate amount of initiator, continue to incubate and stir at this temperature for 55-65 minutes, adjust the pH value of the solution to 7.5-8.5 after the incubation, and then filter, After drying, a modified acrylic resin is obtained.

The above-mentioned water-based printing ink for plastic outer packaging does not have the problem of solvent volatilization, and is healthier and more environmentally friendly than traditional printing inks. And by adding the modified acrylic acid resin prepared by a specific method, the adhesion, viscosity and coloring power of the ink have been significantly improved, and it has a good application prospect.

In one embodiment, the molecular weight of the water-based alkyd resin is 2000-2500.

In one of the embodiments, the methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate are mixed in a molar ratio of 6:3:1.

In one of the embodiments, the initiator is any one of benzoic acid peroxide, potassium persulfate, and dicumyl peroxide.

In one of the embodiments, the leveling agent is any one of fluorinated siloxane, alkylbenzene-modified polydimethylsiloxane, and polyacrylate.

In one of the embodiments, the defoamer is a silicone defoamer.

This application also provides a method for preparing the above-mentioned water-based printing ink for plastic outer packaging, including the following steps:

(1) Add the water-based alkyd resin and modified acrylic resin to the mixer, and stir for 30-50 minutes at a temperature of 50-60°C at a rate of 400-600 revolutions per minute to obtain a premix;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 35-40°C, and the stirring speed is 500-600 revolutions per minute. After stirring for 20-30 minutes, the mixed slurry is ground by a three-roller. Grind to a particle size of less than 10μm to obtain a mixed color paste;

(3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer to the reactor at a rate of 1000 to 1200 revolutions per minute. Stir at a high speed for 60 to 80 minutes to obtain a rough printing ink;

(4) Add penetrant and dispersant to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50 nm to prepare the water-based printing ink for plastic outer packaging.

The preparation method of the printing ink has readily available raw materials and simple process, and is suitable for large-scale industrial production.

In one of the embodiments, the preparation method of the modified acrylic resin is: in a reaction kettle, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate uniformly, heat the reaction kettle, and wait for the temperature When the temperature reaches 65～70℃, keep and stir for 35～45 minutes, then increase the temperature to 85～88℃, add a proper amount of initiator, continue to keep and stir at this temperature for 55～65 minutes, adjust the pH of the solution to 7.5～8.5 after the temperature is over , And then filtered and dried to obtain modified acrylic resin.

In one of the embodiments, the penetrant is TEP or SP-2, and the dispersant is Clariant Dispersant 2774.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention overcomes the problem of environmental pollution caused by easy volatilization of printing ink solvents in the prior art, and the product is green and environmentally friendly, and will not adversely affect the environment.

(2) By adding modified acrylic resin to the printing ink raw material, the present invention significantly improves the adhesion, viscosity and coloring power of the ink, and has a good application prospect.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terminology used in the description of the present invention herein is only for the purpose of describing specific embodiments, and is not intended to limit the present invention. The term "and/or" as used herein includes any and all combinations of one or more related listed items.

The raw materials and reagents used in the following examples are all commercially available common raw materials and reagents.

A water-based printing ink for plastic outer packaging, composed of the following raw materials in weight percentage:

Water-based alkyd resin 30～50%

Modified acrylic resin 15～25%

Ceramic powder 3～5%

Inorganic pigment 2.5～4.5%

Leveling agent 0.5～1.5%

Antifoaming agent 0.5～1.5%

Deionized water balance;

Wherein, the preparation method of the modified acrylic resin is: in a reaction kettle, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate uniformly, and heat the reaction kettle until the temperature reaches 65-70°C Incubate and stir for 35-45 minutes, then increase the temperature to 85-88°C, add an appropriate amount of initiator, continue to incubate and stir at this temperature for 55-65 minutes, adjust the pH value of the solution to 7.5-8.5 after the incubation, and then filter, After drying, a modified acrylic resin is obtained.

The modified acrylic resin prepared by the above method has cross-linking between the starting components during the reaction process, forming a compound with a more complex spatial structure, and can enhance the particle retardation in the ink system. Viscosity. At the same time, the prepared modified acrylic resin has good pigment dispersibility, and can promote the film formation of the water-based alkyd resin and the coating ability of inorganic pigment particles, and significantly improve the adhesion of the ink on the plastic surface.

In a preferred embodiment, the molecular weight of the aqueous alkyd resin is 2000-2500.

In a preferred embodiment, the methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate are mixed in a molar ratio of 6:3:1.

In a preferred embodiment, the initiator is any one of benzoic acid peroxide, potassium persulfate, and dicumyl peroxide.

In a preferred embodiment, the leveling agent is any one of fluorinated siloxane, alkylbenzene-modified polydimethylsiloxane, and polyacrylate.

In a preferred embodiment, the defoamer is a silicone defoamer.

This application also provides a method for preparing the above-mentioned water-based printing ink for plastic outer packaging, including the following steps:

(1) Add the water-based alkyd resin and the modified acrylic resin to the mixer, and stir for 30-50 minutes at a rate of 400-600 revolutions per minute at a temperature of 50-60°C to obtain a premix;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 35-40°C, and the stirring speed is 500-600 revolutions per minute. After stirring for 20-30 minutes, the mixed slurry is ground by a three-roller. Grind to a particle size of less than 10μm to obtain a mixed color paste;

(3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer to the reactor at a rate of 1000 to 1200 revolutions per minute. Stir at a high speed for 60 to 80 minutes to obtain a rough printing ink;

(4) Add penetrant and dispersant to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50 nm to prepare the water-based printing ink for plastic outer packaging.

In a preferred embodiment, the method for preparing the modified acrylic resin is: in a reaction kettle, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate uniformly, and heat the reaction kettle to wait When the temperature reaches 65～70℃, keep and stir for 35～45 minutes, then increase the temperature to 85～88℃, add an appropriate amount of initiator, continue to keep and stir at this temperature for 55～65 minutes, adjust the pH value of the solution to 7.5～7.5 after the temperature is over 8.5, after filtering and drying, the modified acrylic resin is obtained.

In a preferred embodiment, the penetrant is TEP or SP-2, and the dispersant is Clariant Dispersant 2774

The following examples further illustrate the present invention. It should be noted that the present invention is not limited to the described embodiments.

Example 1

Preparation of modified acrylic resin: In a reactor, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate at a molar ratio of 6:3:1, and heat the reactor until the temperature reaches 65°C Incubate and stir for 35 minutes, then increase the temperature to 85° C., add an appropriate amount of initiator, continue to incubate and stir for 55 minutes at this temperature, adjust the pH of the solution to 7.5 after the incubation is over, and then filter and dry to obtain a modified acrylic resin.

Prepare raw materials according to the following weight percentages:

Water-based alkyd resin 30%

Modified acrylic resin 15%

Ceramic powder 3%

Inorganic pigment 2.5%

Leveling agent 0.5%

Antifoaming agent 0.5%

Deionized water balance;

Preparation of water-based printing ink for plastic outer packaging:

(1) Add the water-based alkyd resin and the modified acrylic resin to the mixer, and stir for 30 minutes at a temperature of 50°C at a rate of 400 rpm to obtain a premix;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 35°C, and the stirring rate is 500 rpm. After stirring for 20 minutes, the mixed slurry is ground by a three-roller, and the particle size is less than 10 μm. Get mixed color paste;

(3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer to the reactor at a high speed of 1000 revolutions per minute. Stir for 60 minutes to obtain printing crude ink;

(4) Add penetrant TEP and Clariant dispersant 2774 to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50nm, to make the plastic outer packaging Water-based printing ink.

Example 2

Preparation of modified acrylic resin: In a reactor, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate at a molar ratio of 6:3:1, and heat the reactor until the temperature reaches 67.5°C The temperature is kept and stirred for 40 minutes, then the temperature is raised to 86.5°C, an appropriate amount of initiator is added, and the temperature is kept and stirred for 60 minutes. After the temperature is over, the pH value of the solution is adjusted to 8.0, and then filtered and dried to obtain a modified acrylic resin.

Prepare raw materials according to the following weight percentages:

Water-based alkyd resin 40%

Modified acrylic resin 20%

Ceramic powder 4%

Inorganic pigment 3.5%

Leveling agent 1%

Defoamer 1%

Deionized water balance;

Preparation of water-based printing ink for plastic outer packaging:

(1) Add the water-based alkyd resin and modified acrylic resin to the mixer, and stir at a temperature of 55° C. at a rate of 500 revolutions per minute for 40 minutes to obtain a premix;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 37.5°C, the stirring rate is 550 revolutions per minute. After stirring for 25 minutes, the mixed slurry is ground by a three-roller, and the particle size is less than 10 μm. Get mixed color paste;

(3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer into the reactor at a high speed of 1100 revolutions per minute. Stir for 70 minutes to get printing rough ink;

(4) Add penetrant TEP and Clariant dispersant 2774 to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50nm, to make the plastic outer packaging Water-based printing ink.

Example 3

Preparation of modified acrylic resin: In a reactor, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate in a molar ratio of 6:3:1, and heat the reactor until the temperature reaches 70°C Incubate and stir for 45 minutes, then increase the temperature to 88°C, add an appropriate amount of initiator, continue to incubate and stir at this temperature for 65 minutes, adjust the pH of the solution to 8.5 after the incubation is over, and then filter and dry to obtain a modified acrylic resin.

Prepare raw materials according to the following weight percentages:

Water-based alkyd resin 50%

Modified acrylic resin 25%

Ceramic powder 5%

Inorganic pigment 4.5%

Leveling agent 1.5%

Antifoaming agent 1.5%

Deionized water balance;

Preparation of water-based printing ink for plastic outer packaging:

(1) Add the water-based alkyd resin and the modified acrylic resin to the mixer, and stir for 50 minutes at a temperature of 60°C at a rate of 600 rpm to obtain a premix;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 40°C and the stirring rate is 600 rpm. After stirring for 30 minutes, the mixed slurry is ground by a three-roller, and the particle size is less than 10 μm. Get mixed color paste;

(3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add the leveling agent and defoamer to the reactor at a high speed of 1200 revolutions per minute. Stir for 80 minutes to get printing rough ink;

(4) Add penetrant TEP and Clariant dispersant 2774 to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50nm, to make the plastic outer packaging Water-based printing ink.

Comparative example 1

Prepare raw materials according to the following weight percentages:

Water-based alkyd resin 60%

Ceramic powder 4%

Inorganic pigment 3.5%

Leveling agent 1%

Defoamer 1%

Deionized water balance;

Preparation of water-based printing ink for plastic outer packaging:

(1) Add the water-based alkyd resin to the blender, and stir for 40 minutes at a rate of 500 revolutions per minute at a temperature of 55°C;

(2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 37.5°C, the stirring rate is 550 revolutions per minute. After stirring for 25 minutes, the mixed slurry is ground by a three-roller, and the particle size is less than 10 μm. Get mixed color paste;

(3) Put the water-based alkyd resin after heat stirring in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer to the reactor at 1,100 revolutions Stir at high speed for 70 minutes at a rate of 1/min to obtain printing crude ink;

(4) Add penetrant TEP and Clariant dispersant 2774 to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50nm, to make the plastic outer packaging Water-based printing ink.

Performance Testing

For the water-based printing inks used in plastic outer packaging made in Examples 1-3, the printing inks made in Comparative Example 1 were tested for their performance, and used commercially available water-based printing inks (purchased from Yantai Hengxing Ink Co., Ltd.) As a control example. Among them, the adhesion fastness test is performed according to GB/T 13217.7-2009, the tinting strength test is performed according to GB/T 13217.6-2008, and the viscosity test is performed according to GB/T 13217.4-2008. The test structure is shown in Table 1.

Table 1

To	Example 1	Example 2	Example 3	Comparative example 1	Control example
Adhesion fastness (%)	100	100	100	90	95
Tinting strength (%)	100	100	100	89	92
Viscosity	26	27	27	19	20

It can be seen from Table 1 that the water-based printing inks for plastic outer packaging prepared in the examples of the present invention have significantly improved adhesion, tinting strength, and viscosity compared with the printing inks prepared in the comparative example. , And it is also significantly better than commercially available ordinary water-based printing inks. It can be proved that adding the modified acrylic resin prepared by the specific method of the present invention has a substantial effect on the improvement of the overall performance of the ink. It can be seen that the water-based printing ink used for plastic outer packaging of the present invention has achieved expected technical effects in terms of use performance and safety, and has good application prospects.

The above-mentioned embodiments only express several embodiments of the present invention, and the descriptions are more specific and detailed, but they should not be understood as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all fall within the protection scope of the present invention.

Claims (8)

1. A water-based printing ink for plastic outer packaging, characterized in that it is composed of the following raw materials in weight percentage:

   Water-based alkyd resin 30～50%

   Modified acrylic resin 15～25%

   Ceramic powder 3～5%

   Inorganic pigment 2.5～4.5%

   Leveling agent 0.5～1.5%

   Antifoaming agent 0.5～1.5%

   Deionized water balance;

   Wherein, the preparation method of the modified acrylic resin is: in a reaction kettle, mix methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate uniformly, and heat the reaction kettle until the temperature reaches 65-70°C Incubate and stir for 35-45 minutes, then increase the temperature to 85-88°C, add an appropriate amount of initiator, continue to incubate and stir at this temperature for 55-65 minutes, adjust the pH value of the solution to 7.5-8.5 after the incubation, and then filter, After drying, a modified acrylic resin is obtained.
2. The water-based printing ink for plastic outer packaging according to claim 1, wherein the molecular weight of the water-based alkyd resin is 2000-2500.
3. The water-based printing ink for plastic outer packaging according to claim 1, wherein the methyl methacrylate, trimethylsilane, and dipentaerythritol hexaacrylate are processed in a molar ratio of 6:3:1 mixing.
4. The water-based printing ink for plastic outer packaging according to claim 1, wherein the initiator is any one of benzoic acid peroxide, potassium persulfate, and dicumyl peroxide.
5. The water-based printing ink for plastic outer packaging according to claim 1, wherein the leveling agent is fluorinated siloxane, alkylbenzene-modified polydimethylsiloxane, and polyacrylate Any of them.
6. The water-based printing ink for plastic outer packaging according to claim 1, wherein the defoaming agent is a silicone defoaming agent.
7. A method for preparing water-based printing ink for plastic outer packaging according to any one of claims 1 to 6, characterized in that it comprises the following steps:

   (1) Add the water-based alkyd resin and the modified acrylic resin to the mixer, and stir for 30-50 minutes at a rate of 400-600 revolutions per minute at a temperature of 50-60°C to obtain a premix;

   (2) Put the ceramic powder and inorganic pigment into the mixer for mixing and stirring. The stirring temperature is 35-40°C, and the stirring speed is 500-600 revolutions per minute. After stirring for 20-30 minutes, the mixed slurry is ground by a three-roller. Grind to a particle size of less than 10μm to obtain a mixed color paste;

   (3) Put the premix obtained in step (1) and the mixed color paste obtained in step (2) into the reactor together, and then add leveling agent and defoamer to the reactor at a rate of 1000 to 1200 revolutions per minute. Stir at a high speed for 60 to 80 minutes to obtain a rough printing ink;

   (4) Add penetrant and dispersant to the rough printing ink obtained in step (3) for dispersion and grinding until the particle size distribution of the rough printing ink reaches 10-50 nm to prepare the water-based printing ink for plastic outer packaging.
8. The method for preparing water-based printing ink for plastic outer packaging according to claim 7, wherein the method for preparing the modified acrylic resin is: in a reaction kettle, methyl methacrylate, trimethyl Mix the silane and dipentaerythritol hexaacrylate evenly, heat the reactor, and keep stirring for 35-45 minutes when the temperature reaches 65-70°C, then heat up to 85-88°C, add appropriate amount of initiator, and continue to keep warm and stirring at this temperature For 55 to 65 minutes, adjust the pH value of the solution to 7.5 to 8.5 after the heat preservation is over, and then filter and dry to obtain a modified acrylic resin.