CN115093751A

CN115093751A - Water-based ink composition, preparation method and application thereof, plastic material and package

Info

Publication number: CN115093751A
Application number: CN202210774640.2A
Authority: CN
Inventors: 朱向阳; 黄涛; 沈金全; 施威格尔·哈拉尔德
Original assignee: Kangmeibao Suzhou Co ltd
Current assignee: Kangmeibao Suzhou Co ltd
Priority date: 2022-07-01
Filing date: 2022-07-01
Publication date: 2022-09-23
Anticipated expiration: 2042-07-01
Also published as: CN115093751B

Abstract

There is provided an aqueous ink composition for printing plastic materials, comprising: a water-based acrylic resin; an aqueous urethane acrylate resin; a pigment; and an aqueous solvent. Also provided is a plastic material having a pattern layer printed with the aqueous ink composition, a process for the preparation of the aqueous ink composition for printing plastic materials, the use of the aqueous ink composition for printing plastic materials and a package comprising plastic materials.

Description

Water-based ink composition, preparation method and application thereof, plastic material and package

Technical Field

At least one embodiment of the present disclosure relates to the field of printing, and in particular, to an aqueous ink composition for printing a plastic material, a plastic material having a pattern layer printed with the aqueous ink composition, a method for preparing the aqueous ink composition for printing a plastic material, use of the aqueous ink composition for printing a plastic material, and a package including a plastic material.

Background

With the increasing living standard, people put higher demands on food packaging. Many food products are beginning to use lightweight composite sheets as packaging materials. The outermost layer of such composite sheets is often made of a plastic layer such as polyethylene. When the composite sheet material for food packaging is printed, the adopted printing ink must meet the principle of environmental protection and harmlessness and can meet the requirement of food safety.

In existing plastic food packaging, solvent-based (SB) inks are often used for printing. The pattern layer printed by the solvent-based ink has bright color, clear lines, few ink dots, and good anti-sticking performance and anti-skid performance. However, with increasingly stringent restrictions on Volatile Organic Compounds (VOCs) in countries around the world, solvent-based inks are tending to be banned and phased out. As an emerging environmental friendly ink, water-based (WB) inks are becoming the dominant ink used in the printing industry.

Disclosure of Invention

According to at least one embodiment of the present disclosure, there is provided an aqueous ink composition for printing a plastic material, including: a water-borne acrylic resin; an aqueous urethane acrylate resin; a pigment; and an aqueous solvent.

For example, the aqueous ink composition further comprises one or more of the following ingredients: a cosolvent; a dispersant; a pH adjusting agent; leveling agent; and an antifoaming agent.

For example, the aqueous ink composition comprises, based on the total weight of the aqueous ink composition: 10 to 20 weight percent of a water-based acrylic resin; 15 to 35 weight percent of aqueous urethane acrylate resin; 10 to 25 wt% of a pigment; 4 to 5 wt% of a co-solvent; 1 to 6 wt% of a dispersant; 0.5 to 2 wt% of a pH adjusting agent; 0.1 wt% to 1 wt% of a leveling agent; 0.1 to 2 wt% of a defoamer; and an aqueous solvent to make up to 100 wt%.

For example, the aqueous acrylic resin has a solid content of 40 to 45 wt%, an acid value of 50 to 100mgKOH/g, and a glass transition temperature of 20 to 60 ℃; the waterborne polyurethane acrylate resin is anionic and is solidThe content is 30 to 50 weight percent, the pH value is 7.5 +/-1, the elongation at break is more than or equal to 500 percent, and the tensile strength is more than or equal to 25kg/cm ² 。

For example, the pigment is an inorganic pigment.

For example, the aqueous solvent is water.

For example, the co-solvent is one or more selected from ethanol, n-propanol and isopropanol.

For example, the pH adjustor is one or more selected from the group consisting of ammonia, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, and triethanolamine.

For example, the aqueous ink composition comprises, based on the total weight of the aqueous ink composition: 15 to 20 weight percent of water-based acrylic resin; 30 to 35 weight percent of aqueous urethane acrylate resin; 10 to 12 wt% of a pigment; 4.5 wt% to 5 wt% of a co-solvent; 2 to 5 wt% of a dispersant; 0.5 to 1.5 wt% of a pH adjusting agent; 0.5 wt% to 1 wt% of a leveling agent; 0.1 to 0.2 wt% of a defoamer; and water to make up to 100 wt%.

There is also provided in accordance with at least one embodiment of the present disclosure a plastic material having a design layer printed with an aqueous ink composition, wherein the design layer includes: acrylic resin; a urethane acrylate resin; and a pigment.

For example, the pattern layer further comprises one or more of: a dispersant; a pH adjusting agent; leveling agent; and an antifoaming agent.

For example, the plastic material is a polyethylene film.

For example, the plastic material has a static coefficient of friction of 0.37 to 0.47 on the printed side and 0.45 to 0.55 on the non-printed side, when measured using a flat friction coefficient meter under conditions of 200g load, 100mm/min speed, 0-5N test force and 0-80 ℃; the plastic material has a dynamic coefficient of friction of 0.25 to 0.35 on the printed side and 0.35 to 0.45 on the non-printed side.

For example, when more than one piece of said plastic material is applied at 3kg/cm ² At a temperature of 45 ℃ for 24 hours with the printing surface facing the printing surfaceAnd then, the printing surface of the plastic material is not stuck to the printing surface.

According to at least one embodiment of the present disclosure, there is also provided a method for preparing an aqueous ink composition for printing a plastic material, wherein the aqueous ink composition includes: a water-based acrylic resin; an aqueous urethane acrylate resin; a pigment; and an aqueous solvent; the method comprises the following steps: 1) uniformly mixing the water-based acrylic resin with the pigment; 2) adding a part of the aqueous urethane acrylate resin into the mixture prepared in the step 1); 3) adding a portion of the aqueous solvent to the mixture prepared in step 2); 4) grinding the mixture obtained in the step 3) until the fineness is less than or equal to 20 mu m; 5) mixing the rest of the aqueous solvent and the rest of the aqueous polyurethane acrylic resin, adding the mixture prepared in the step 4), and uniformly mixing to obtain the aqueous ink composition.

For example, the aqueous ink composition further comprises one or more of: cosolvent, dispersant, pH regulator, leveling agent and defoaming agent.

For example, the adding a portion of the aqueous solvent to the mixture prepared in step 2) comprises: uniformly mixing a part of the aqueous solvent with one or more of the cosolvent, the dispersant, the pH regulator and the defoaming agent, and then adding the mixture into the mixture prepared in the step 2).

For example, the leveling agent is added after step 4) and before, after, or simultaneously with step 5).

For example, the aqueous ink composition includes: 15 to 20 weight percent of a water-based acrylic resin; 30 to 35 weight percent of aqueous urethane acrylate resin; 10 to 12 wt% of a pigment; 4.5 wt% to 5 wt% of a co-solvent; 2 to 5 wt% of a dispersant; 0.5 to 1.5 wt% of a pH adjusting agent; 0.5 wt% to 1 wt% of a leveling agent; 0.1 to 0.2 wt% of a defoamer; and water to make up to 100 wt%.

There is also provided, in accordance with at least one embodiment of the present disclosure, use of an aqueous ink composition as described in at least one embodiment of the present disclosure for printing plastic materials.

There is also provided, in accordance with at least one embodiment of the present disclosure, a package including a plastic material as described in at least one embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in the description and claims of the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item preceding the word comprises the element or item listed after the word and its equivalent, but does not exclude other elements or items. "inner", "outer", "upper", "lower", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In addition to conventional containers made of glass, ceramic, metal, etc., a packaging container that is widely used at present is formed by cutting, folding, and sealing a composite sheet. The composite sheet may typically comprise a plurality of layers laminated together, with the outermost layer often being formed of a plastic material (e.g. PE film or the like) to act as a barrier/protective layer.

According to government regulations, many necessary information including names, ingredient lists, manufacturers, expiration dates, storage conditions, and production license numbers must be displayed on the outsourcing food. Over the past decades, packaging manufacturers have typically used solvent-based inks to print the various necessary information on the plastic material layers of the exterior package for foodstuffs. However, with the increasingly stringent restrictions on Volatile Organic Compounds (VOCs) in countries around the world, solvent-based inks are tending to be banned and phased out. As a new environment-friendly ink, water-based ink is becoming the dominant ink used in the printing industry. Although such aqueous ink-printed packaging containers have been advanced with the development of technology in recent years, various problems still remain, such as dark color of the pattern layer formed by printing with aqueous ink, insufficient definition of lines, easy formation of ink dots by aggregation, and weak anti-sticking and anti-slip properties.

In view of such a series of problems, the inventors of the present application have conducted extensive and intensive studies on aqueous inks. The water-based ink is mainly formed by mixing and grinding a water-soluble or water-dispersible resin, a pigment, a solvent and optionally one or more auxiliary agents. Among them, the inventors of the present application found that the selection of a water-soluble or water-dispersible resin is a key factor in solving some of the problems currently existing in aqueous ink compositions for printing plastic materials.

According to at least one embodiment of the present disclosure, there is provided an aqueous ink composition for printing a plastic material, including: a water-based acrylic resin; an aqueous urethane acrylate resin; a pigment; and an aqueous solvent.

As used herein, the term "plastic material" generally refers to a high molecular compound material formed by polymerization by addition polymerization or condensation polymerization starting from monomers and/or oligomers. Examples of plastic materials may include, but are not limited to, polyolefins such as Polyethylene (PE), polypropylene (PP), Polyisoprene (PI), and the like; polyurethanes, such as thermoplastic polyurethane elastomer rubber (TPU), and the like; vinyl plastics such as polyvinyl chloride (PVC), etc.; acrylic plastics such as polymethyl methacrylate (PMMA) and the like; polyamides (PA), such as nylon, and the like; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like; polystyrenes; polysulfones; polyethers; polyether ether ketones; cellulose plastics; and so on. Polyethylene (PE) plastics are widely used in the food packaging industry, particularly as the outermost layer material of composite sheets for packaging, due to their non-toxicity, high transparency, high chemical resistance, and the like. The aqueous ink compositions provided in the embodiments of the present disclosure may be used to print any plastic material. In one aspect, the aqueous ink composition provided in the embodiments of the present disclosure may be used to print polyolefin-based plastic materials, such as Polyethylene (PE) films and the like.

As used herein, the term "ink" generally refers to a homogeneous, fluid, paste-like adherent composed of a color body (e.g., pigment, dye, etc.), a vehicle, a solvent, and optionally one or more auxiliary agents, capable of being printed and dried on a substrate. The term "water-based ink (WB ink)" generally refers to a Volatile Organic Compound (VOC) -free ink made by complex processing milling of a water-soluble or water-dispersible resin, a pigment, a solvent, and optionally one or more adjuvants. The water-based ink is particularly suitable for packaging and printing products with strict requirements on sanitary conditions, such as food, beverage, medicines, toys for children and the like, and is also called as environment-friendly ink. In the aqueous ink, a water-soluble or water-dispersible resin is mainly used as a binder, which can uniformly disperse pigment particles, adjust the viscosity and fluidity of the ink, and provide adhesion to a material of a substrate (e.g., paper, plastic film, etc.) so that the ink can form a uniform film layer after printing. The pigment is mainly used to provide color, which can be uniformly distributed in the binder in a particulate state, and the ink can be colored by absorption, reflection, refraction and transmission of light. Pigments are generally required to have bright color, appropriate tinting strength and hiding power, and high degree of dispersion; in some cases, it is also desirable that the pigment have some abrasion resistance. The solvent functions to dissolve the resin, adjust the viscosity and fluidity of the ink, and adjust the drying property of the ink. The solvent used in the aqueous ink is an aqueous solvent, for example, water. In addition to the water-soluble water-dispersible resin, the pigment and the solvent, the aqueous ink may optionally include one or more auxiliary agents including, but not limited to, a cosolvent, a dispersant, a pH adjuster, a leveling agent, an antifoaming agent, a rheology modifier, a thickener, a diluent, a slow-drying agent, and the like, according to the purpose of use and actual needs.

In one aspect, the aqueous ink composition of embodiments of the present disclosure may include an aqueous acrylic resin and an aqueous urethane acrylate resin. As used herein, the term "acrylic resin" is generally a generic term for polymers formed by polymerization of acrylic monomers or oligomers (e.g., acrylic acid, methacrylic acid, acrylate esters, methacrylate esters, or oligomers thereof); the term "aqueous acrylic resin" generally refers to an aqueous acrylic resin dispersion that may have an aqueous solvent/dispersant as the dispersing medium, including, but not limited to, acrylic resin emulsions, aqueous acrylic resin dispersions (also known as water-dilutable acrylics), aqueous acrylic resin solutions, and the like. In one aspect of embodiments of the present disclosure, the aqueous acrylic resin used may have a solid content of 40 to 45 wt%, an acid value of 50 to 100mgKOH/g, and a glass transition temperature (T @) _g ) Can be from 20 ℃ to 60 ℃. In another aspect, the aqueous ink composition may include 10 wt% to 20 wt% of the aqueous acrylic resin, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 15 wt% to 20 wt% of the aqueous acrylic resin, based on the total weight of the aqueous ink composition.

As used herein, the term "urethane acrylate (PUA) resin" generally refers to an oligomer resin having a urethane functional group made by an addition reaction of a polyol, a polyisocyanate, β -hydroxyethyl acrylate, β -hydroxyethyl methacrylate, or the like; the term "aqueous urethane acrylate resin" generally refers to a urethane acrylate resin dispersion that may have an aqueous solvent/dispersant as a dispersion medium. In one aspect of embodiments of the present disclosure, the aqueous urethane acrylate resin used may be anionic, may have a solid content of 30 wt% to 50 wt%, a pH of about 7.5 + -1, an elongation at break of 500% or more, and a tensile strength of 25kg/cm or more ² . In another aspect, the aqueous ink composition may include 30 wt% to 35 wt% of the aqueous urethane acrylate resin, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may be based on the total weight of the aqueous ink compositionComprises 30 to 35 weight percent of aqueous polyurethane acrylate resin.

The aqueous acrylic resin and the aqueous urethane acrylate resin are used together as a binder in the aqueous ink composition of the embodiments of the present disclosure. The combination of the aqueous polyacrylic resin and the aqueous urethane acrylate resin can have multiple functions as a connecting material, including but not limited to, the combination can be used as a carrier for uniformly dispersing pigment particles; provide good adhesion to the plastic material of the printing stock (such as PE plastic film and the like) so that the pigment is finally fixed on the surface of the printing stock; the water-based ink can form a uniform film layer after being printed; the pigment in the finally formed pattern layer is protected, so that the pigment is not easy to fall off; and provides a certain flexibility and chemical resistance to the pattern layer after printing, etc. The selection of the binder has great influence on the printability and the printing effect of the ink, such as viscosity, fluidity, drying performance, brightness, fixation speed and the like, so that the selection of the proper binder is one of the keys for ensuring good printing, and the composition and the proportion of the binder are particularly adjusted according to the difference of packaging materials, printing requirements and the like.

In another aspect, the aqueous ink composition may further include a colorant capable of allowing it to exhibit various colors. Colorants can generally include pigments and dyes, which differ primarily in solubility, i.e., the dyes are soluble in the dispersion medium; pigments are not soluble in the dispersion medium nor in the substrate to be colored. In addition, pigments and dyes can also be distinguished by transparency, hiding power, coloring method, durability, light resistance, weather resistance, and the like. As used herein, the term "pigment" generally refers to an insoluble substance that imparts color to an object. Pigments can be generally classified into organic pigments and inorganic pigments according to their compositions. As used herein, the term "inorganic pigment", also sometimes referred to as mineral pigment, generally refers to pigments whose major constituent is inorganic, including but not limited to various metal oxides, chromates, carbonates, sulfates, sulfides, carbon powder, metal powders, and the like, such as zinc white, titanium white, copper powder, aluminum powder, carbon black, and the like. The inorganic pigments can be further classified into natural inorganic pigments such as cinnabar, red earth, realgar and the like according to sources; and synthetic inorganic materials such as titanium white, chrome yellow, iron blue, cadmium red, cadmium yellow, lithopone, carbon black, iron oxide red, iron oxide yellow, and the like. As used herein, the term "organic pigment" generally refers to an insoluble coloring substance whose main component is organic, which is generally added to a substrate in a highly dispersed state to color the substrate. Pigments used in inks are generally required to have high tinting strength, hiding power, chemical resistance, light resistance, weather resistance, and the like, while being capable of being well dispersed in a vehicle. In embodiments of the present disclosure, pigments may generally be used as colorants in aqueous ink compositions. In one aspect of embodiments of the present disclosure, the pigment used may be an inorganic pigment. In another aspect, the aqueous ink composition may include 10 wt% to 25 wt% of the pigment, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 10 wt% to 12 wt% of the pigment, based on the total weight of the aqueous ink composition.

In another aspect, the aqueous ink composition of the present disclosure may also optionally include one or more adjuvants, such as, but not limited to, one or more of the following: a cosolvent; a dispersant; a pH adjusting agent; leveling agent; and (4) defoaming agent.

As used herein, the term "co-solvent" generally refers to a substance used to help increase the solubility of a substance in a solvent. Examples of co-solvents suitable for use in aqueous ink compositions may generally include low molecular alcohols such as ethanol, propanol, butanol, ethylene glycol, glycerol, and the like. The cosolvent can be used for improving the dissolution of the resin and/or the pigment in the ink and adjusting the volatilization speed of the ink and the leveling of the ink. In one aspect of embodiments of the present disclosure, the co-solvent used may be one or more of ethanol, n-propanol, and isopropanol. In another aspect, the aqueous ink composition can include 4 wt% to 5 wt% of a co-solvent, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 4.5 wt% to 5 wt% of a co-solvent, based on the total weight of the aqueous ink composition.

As used herein, the term "dispersant" generally refers to an auxiliary agent that enhances or improves the dispersion properties of a solid or liquid material. During the preparation process of the water-based ink, the dispersant is added to improve the properties of the water-based ink. For example, aqueous inks are generally required to have a range of fineness, and either too fine or too large of a fineness of the aqueous ink may affect the fluidity and rheology of the aqueous ink, resulting in adverse effects on printing performance and printing effect. Examples of dispersants suitable for use in the aqueous ink composition may generally include anionic dispersants that make pigment particles to which the anionic dispersants are attached repel each other using the principle that the same charge (negative charge) repels each other and are difficult to aggregate into larger particles to precipitate; and a nonionic dispersant which can displace pigment particles to which a negatively charged dispersant has been attached when the particles are close to each other and are likely to aggregate, and this function is called steric hindrance. The fluidity/rheological property/color-developing property/coverage property/glossiness of the water-based ink composition added with a proper dispersant can be greatly improved; and the stability of the water-based ink is relatively improved and the precipitation/delamination phenomenon is reduced during the using process or the storage process of the water-based ink. Therefore, the addition of the dispersant has a certain advantageous effect on the aqueous ink. In one aspect of embodiments of the present disclosure, the dispersant used may be, for example, one or more of Solsperse 27000, Solsperse 46000, Solsperse 47000, Solsperse WV400, and Solsperse W100. In another aspect, the aqueous ink composition may include 1 wt% to 6 wt% of the dispersant, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 4.5 wt% to 5 wt% of the dispersant, based on the total weight of the aqueous ink composition.

As used herein, the term "pH adjuster" generally refers to an aid that is capable of maintaining or changing the pH of a material. In the raw materials of aqueous ink compositions, small amounts of polymerizable acids such as acrylic acid and methacrylic acid, etc. are often present, and the addition of a pH adjuster can neutralize these acids into salts to adjust the pH of these inks. In addition, the pH regulator can be used for improving the viscosity of the water-based ink, regulating the drying speed and leveling property and helping the dispersion of the pigment. Examples of suitable pH adjusters for use in aqueous ink compositions may include alkali or alkaline earth metal hydroxides, amines, alkamines, or alkamines pH adjusters including, but not limited to, sodium hydroxide, potassium hydroxide, ammonia, methylamine, dimethylamine, ethylamine, diethylamine, triethylamine, N-propylamine, isopropylamine, N-butylamine, N-methylethanolamine, dimethylethanolamine, and the like. In one aspect of the disclosed embodiments, the pH dispersant used may be one or more selected from the group consisting of ammonia, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine. In another aspect, the aqueous ink composition may include 0.5 wt% to 2 wt% of the pH adjusting agent, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 0.5 wt% to 1.5 wt% of the pH adjusting agent, based on the total weight of the aqueous ink composition.

As used herein, the term "leveling agent" generally refers to an aid that promotes the formation of a smooth, glossy, and uniform film layer of the ink during drying to form a film. Leveling agents generally provide good leveling and uniformity properties to a film layer by reducing the surface tension of the film layer. Examples of leveling agents suitable for use in the aqueous ink composition may include surfactants and polyacrylic acid, carboxymethylcellulose, and the like. In one aspect of the disclosed embodiments, the leveling agent used may be, for example, one or more selected from the group consisting of SWT-24, BYK-333, and Tego 270. In another aspect, the aqueous ink composition may include 0.1 wt% to 1 wt% of the leveling agent, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 0.5 wt% to 1 wt% of the leveling agent, based on the total weight of the aqueous ink composition.

As used herein, the term "antifoam" generally refers to a substance that lowers the surface tension of a liquid, prevents the formation of foam, or reduces or eliminates the original foam. In aqueous ink compositions, there are often present a large amount of a medium having a foam-stabilizing action such as a resin or emulsion, a dispersant, a surfactant, and the like. During the milling, toning, stirring and printing processes, a large amount of bubbles (including macro bubbles and micro bubbles) are easily generated due to the introduction of air, resulting in deterioration of the uniformity of the ink, generation of printing surface defects or influence on the film forming property, the shrinkage cavity property or the transparency. The foam also causes various other production problems such as reduction in production efficiency, increase in energy consumption, difficulty in producing prints, and the like. The defoaming agent is added to eliminate the foam in the printing ink, improve the dispersion effect of the pigment and protect the uniformity of the printing ink, thereby reducing the printing problem of the printing ink. Examples of the defoaming agent suitable for use in the aqueous ink composition may include polyether block type defoaming agents, silicone type defoaming agents, composite type defoaming agents (e.g., mineral oil/wax/silicone type, mineral oil/hydrophobic particles/silicone, silicone/hydrophobic particles, etc.). In one aspect of an embodiment of the present disclosure, the defoaming agent used may be one or more selected from Tego-825, Tego-822, Tego 902W, and Tego 901W. In another aspect, the aqueous ink composition may include 0.1 wt% to 2 wt% of the leveling agent, based on the total weight of the aqueous ink composition. For example, the aqueous ink composition may include 0.1 wt% to 0.2 wt% of the defoamer, based on the total weight of the aqueous ink composition.

In addition to one or more of the above-mentioned optionally added co-solvent, dispersant, pH adjuster, leveling agent, and defoaming agent, the aqueous ink composition of the embodiment of the present disclosure may optionally further include one or more of the following according to the purpose of use and actual need: the thinner can thin the ink, increase the fluidity of the ink and reduce the viscosity of the ink; the viscosity removing agent is also called viscosity reducing agent, which can reduce the viscosity of the ink and simultaneously does not influence the body and the bone of the ink; the drier (drying agent) can accelerate the drying speed of the printing ink; the slow drying agent can slow down the drying speed of the printing ink; a thinner, also called a thinner, for thinning the color of the ink; a reverse gelatinizing agent for preventing the gelling, thickening and caking of the ink; an anti-drying agent (antioxidant) which can retard the oxidative polymerization process of the ink; the anti-smudge agent (anti-set-off agent) can prevent ink on the printed matter from being set off to the back of another printed matter; the surfactant can improve the dispersibility of the solid components and prevent the solid components from aggregating and precipitating; the preservative can prolong the storage time of the water-based ink; the ultraviolet absorbent can improve the sun-proof performance of printed matters; the friction promoter can improve the friction coefficient of the printed matter; the gloss promoter can improve the glossiness of the printed pattern; stabilizers can improve the stability of the ink and/or print; and so on. The person skilled in the art will be able to know in which case and in which case any of the above-mentioned auxiliaries should be added, without the present disclosure being restricted in particular thereto.

In another aspect, the aqueous ink composition may further include an aqueous solvent as a dissolving or dispersing medium. As used herein, the term "aqueous solvent" generally refers to water or an aqueous solution containing small amounts of other substances such as alcohols and the like. The aqueous solvent is generally used for dissolving, dispersing or diluting a resin, dispersing a pigment, adjusting the viscosity of an ink, adjusting the drying speed of an ink, accelerating permeation, suppressing foaming, and the like. Solvents for aqueous ink compositions also need to have non-toxic and VOC-free characteristics. Exemplary aqueous solvents may be water (e.g., tap water, pure water, deionized water, etc.), brine, water containing small amounts of low molecular alcohols, and the like. In one aspect of embodiments of the present disclosure, the aqueous solvent used may be water. In another aspect, the aqueous ink composition may include an aqueous solvent to make up the other components to 100 wt%, based on the total weight of the aqueous ink composition.

At least one embodiment of the present disclosure also provides a plastic material having a pattern layer printed with an aqueous ink composition, wherein the pattern layer may include: acrylic resin; a urethane acrylate resin; and a pigment. For example, the acrylic, urethane acrylic and pigment may be as described above.

In one aspect, the pattern layer may further include, for example, one or more of a dispersant, a pH adjuster, a leveling agent, and an antifoaming agent. For example, the dispersing agent, pH adjuster, leveling agent, and defoaming agent may be as described above. Besides, the pattern layer may optionally include one or more of the following aids according to the purpose of use and actual needs: diluent, viscosity-removing agent, drier (drying agent), slow-drying agent, diluent, anti-gelatinizing agent, anti-drying agent (antioxidant), anti-dirty agent (anti-set-off agent), surfactant, preservative, ultraviolet absorbent, etc. The above auxiliaries may be as described above. The person skilled in the art will be able to know in which case and in which auxiliary agents should be added, and the disclosure is not restricted in particular thereto.

In another aspect, the plastic material may include, but is not limited to, polyolefins such as Polyethylene (PE), polypropylene (PP), Polyisoprene (PI), and the like; polyurethanes, such as thermoplastic polyurethane elastomer rubber (TPU), and the like; vinyl plastics such as polyvinyl chloride (PVC), etc.; acrylic plastics such as polymethyl methacrylate (PMMA) and the like; polyamides (PA), such as nylon, and the like; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like; polystyrenes; polysulfones; polyethers; polyether ether ketones; cellulose plastics; and so on. For example, the plastic material may be a polyolefin based plastic, such as a polyethylene film.

For example, the plastic material may be a plastic material having a pattern layer printed with any of the aqueous ink compositions as provided in embodiments of the present disclosure.

In one aspect, the plastic materials of embodiments of the present disclosure can have good release properties. For example, when measured using a flat surface coefficient of friction meter under conditions of 200g load, 100mm/min speed, 0-5N test force, and 0-80 ℃, the static coefficient of friction of a plastic material may be: the printing surface is 0.37 to 0.47 of the printing surface, and the printing surface is 0.45 to 0.55 of the non-printing surface. In addition, when more than one plastic material is added at 3kg/cm ² And a temperature of 45 c, the printed face of the plastic material has no blocking phenomenon on the printed face after being stacked for 24 hours. When a plastic material having such good release properties is used as the outermost layer of the composite sheet for packaging, the composite sheet can be effectively prevented from blocking when placed in layers, thereby greatly reducing unnecessary loss of the composite sheet when stored or transported in superposed form.

In another aspect, the plastic material of the disclosed embodiments may also have good non-slip properties. For example, the plastic material may have a dynamic coefficient of friction of 0.25 to 0.35 on the print side and 0.35 to 0.45 on the non-print side, when measured using a plane friction coefficient meter under conditions of 200g load, 100mm/min speed, 0-5N test force and 0-80 ℃. When a plastic material having such good anti-slip properties is used as the outermost layer of the composite sheet for packaging, it is possible to effectively prevent the composite sheet from relative slippage when stacked for transportation on, for example, a conveyor belt, thereby greatly reducing the increase in the rejection rate due to material displacement and improving the processability of the composite sheet.

Further, the existing water-based ink is not easy to print on the surface of the plastic material at high speed (for example, 450-600 m/min, or higher), so the conventional water-based ink is generally applied on the paper material (such as paperboard) during high-speed printing. Any one of the aqueous inks provided in the present embodiment has a faster drying and curing speed in the printing process, and can form a pattern layer on a plastic material (e.g., polyolefin) by gravure printing under high-speed printing.

At least one embodiment of the present disclosure also provides a method for preparing an aqueous ink composition for printing a plastic material, wherein the aqueous ink composition may include: a water-based acrylic resin; an aqueous urethane acrylate resin; a pigment; and an aqueous solvent, the method may comprise:

1) uniformly mixing the water-based acrylic resin and the pigment;

2) adding a part of water polyurethane acrylate resin into the mixture prepared in the step 1);

3) adding a portion of the aqueous solvent to the mixture prepared in step 2);

4) grinding the mixture obtained in the step 3) until the fineness is less than or equal to 20 mu m;

5) mixing the rest of the aqueous solvent and the rest of the aqueous polyurethane acrylic resin, adding the mixture into the mixture prepared in the step 4), and uniformly mixing;

thereby preparing an aqueous ink composition.

In one aspect of the preparation method, the aqueous ink composition may further include one or more of a co-solvent, a dispersant, a pH adjuster, a leveling agent, and a defoaming agent. For example, one or more of a co-solvent, a dispersant, a pH adjuster, and a defoamer can be added after mixing well with a portion of the aqueous solvent prior to the milling step. In addition, a leveling agent may be added after the grinding step.

Besides, the aqueous ink composition may optionally include one or more of the following auxiliaries according to the purpose of use and actual needs: diluents, viscosity-releasing agents, drying agents (desiccants), slow-drying agents, thinning agents, anti-gelling agents, anti-drying agents (antioxidants), anti-soiling agents (anti-set-off agents), surfactants, preservatives, ultraviolet absorbers, friction promoters, gloss promoters, stabilizers and the like, which may be as described above. The person skilled in the art knows when the above-mentioned auxiliaries should be added during the preparation process, which is not particularly limited by the present disclosure.

In another aspect of the method of making, the aqueous ink composition can be any of the aqueous ink compositions provided in the embodiments of the present disclosure. For example, the aqueous ink composition may include 15 wt% to 20 wt% of an aqueous acrylic resin; 30 to 35 weight percent of aqueous urethane acrylate resin; 10 to 12 wt% of a pigment; 4.5 wt% to 5 wt% of a co-solvent; 2 to 5 wt% of a dispersant; 0.5 to 1.5 wt% of a pH adjusting agent; 0.5 wt% to 1 wt% of a leveling agent; 0.1 to 0.2 wt% of a defoamer, and water to make up to 100 wt%.

At least one embodiment of the present disclosure also provides a use of any one of the aqueous ink compositions as provided in embodiments of the present disclosure for printing plastic materials. For example, the plastic material may be a polyolefin based plastic material, such as a polyethylene film.

At least one embodiment of the present disclosure also provides a package comprising any one of the plastic materials provided in embodiments of the present disclosure, the plastic material having a pattern layer printed from an aqueous ink composition. The package may include a plastic material having a patterned layer printed with any of the aqueous ink compositions provided in embodiments of the present disclosure. As an example, the package may be a packaging container formed by cutting, folding and sealing a composite sheet for packaging, such as a brick-type or pillow-type composite paper package or the like.

Examples of the invention

The present invention will be explained in further detail below with reference to examples and comparative examples. However, it will be understood by those skilled in the art that these examples and comparative examples are provided for illustrative purposes only and are not intended to limit the present invention.

Examples 1 to 3: preparation of aqueous ink compositions 1 to 3

Aqueous ink compositions 1-3 were formulated according to the formulations shown in tables 1-3 below. The preparation method comprises the following steps:

1) uniformly mixing the water-based acrylic resin and the pigment;

2) adding 1/2-1/3 of waterborne polyurethane acrylate resin into the mixture prepared in the step 1);

3) adding 1/2-3/5 solvent into the mixture prepared in the step 2);

4) grinding the mixture obtained in the step 3) until the fineness is less than or equal to 20 um;

5) mixing the rest of the solvent and the rest of the waterborne polyurethane acrylic resin, adding the mixture prepared in the step 4), and uniformly mixing;

thereby obtaining an aqueous ink composition.

Table 1: composition of aqueous ink composition 1

Table 2: composition of aqueous ink composition 2

Table 3: composition of aqueous ink composition 3

Comparative example 1: preparation of comparative aqueous ink composition 1

Comparative aqueous ink composition 1 was formulated according to the formulation shown in table 4 below using the same method as in examples 1-3.

Table 4: composition of comparative Water-based ink composition 1

Comparative example 2: preparation of solvent-based ink composition 1

Solvent-based ink composition 1 was formulated according to the formulation shown in table 5 below using the same method as examples 1-3.

Table 5: composition of solvent-based ink composition 1

Test example

1. Printing effect test

5 composite sheets for packaging were prepared. Each of the composite sheets for packaging had a size of 200mm x 150mmx 0.4mm, respectively, and each comprised a paper support layer and a PE film of 0.1mm thickness laminated on the support layer. The same pattern was printed on each composite sheet using the aqueous ink compositions 1 to 3, comparative aqueous ink composition 1 and solvent-based ink composition 1 prepared in examples 1 to 3 and comparative examples 1 to 2, respectively. After the printed pattern was fully cured, the printed pattern was scored by visual observation, with each effect being scored from poor to between 0 and 5 points. The results are shown in Table 6 below.

Table 6: test results of printing effects

2. Coefficient of friction test

The friction coefficient is tested by using a plane friction coefficient tester, and the testing principle is as follows: laying the two test surfaces together; under certain contact pressure, the two surfaces move relatively; the large resistance force (i.e., the static friction force) of the two contact surfaces at the start of the relative movement and the resistance force (i.e., the kinetic friction force) of the two contact surfaces at a certain speed relative movement are recorded. The static friction coefficient and the dynamic friction coefficient are respectively calculated according to the following formulas:

in the experiment, the friction coefficients of the printing surface to the printing surface and the printing surface to the non-printing surface need to be measured respectively

Experimental equipment:

DIN 53375 friction coefficient instrument

The mass of the sliding block is as follows: 200g of the total weight of the mixture; test speed: 100 mm/min; test force: 0-5N; the experimental temperature is 0-80 ℃; data acquisition frequency range: 1-100 Hz.

The operation steps are as follows:

1. diluting the ink to the printing viscosity, and then printing on a required substrate;

2. placing the printed sample in a constant temperature and humidity room for 24 hours to fully dry and cure the sample;

3. each print swatch was cut to a size of 80x 200 mm;

4. at least three times of tests are carried out on each sample, each test comprises a printing surface-printing surface friction test and a printing surface-non-printing surface friction test, and each friction data is recorded;

5. the average value of the measured friction force data is calculated, and the static friction coefficient and the dynamic friction coefficient are respectively calculated according to the average value.

The static friction coefficient and the dynamic friction coefficient (printing surface to printing surface and printing surface to non-printing surface) of the patterns formed after printing by the aqueous ink compositions 1 to 3, the comparative aqueous ink composition 1, and the solvent-based ink composition 1 were measured as described above, and the results are shown in the following tables 7 and 8, respectively.

Table 7: static coefficient of friction test results

Table 8: dynamic friction coefficient test results

3. Anti-sticking performance test

The same pattern was printed at high speed (450 m/min) on the PE film of each group of composite sheets for packaging using the aqueous ink compositions 1 to 3 prepared in examples 1 to 3 and comparative examples 1 to 2, the comparative aqueous ink composition 1 and the solvent-based ink composition 1, respectively, to prepare 5 groups of composite sheets for packaging each of which was 2 sheets. Each of the composite sheets for packaging has a size of 200mm x 150mm x 0.4mm, respectively, and each includes a paper support layer and a PE film of 0.1mm thickness laminated on the support layer. After the printed pattern was completely dried, each set of 2 composite packaging sheets was stacked with the printed surface facing the printed surface. Applying 3kg/cm to the laminated composite sheet ² And allowed to stand at a temperature of 45 ℃ for 24 hours. Subsequently, the laminated composite sheets were separated by hand, and the blocking phenomenon between the two was examined. The results are shown in table 9 below.

Table 9: results of anti-sticking property test

Ink composition numbering	Blocking condition
		Aqueous ink composition 1	Slight adhesion
Aqueous ink composition 2	Slight adhesion
		Aqueous ink composition 3	No adhesion
Comparative Water-based ink composition 1	Can not be uncovered
		Solvent-based ink composition 1	No adhesion

4. Test of anti-skid Property

The same pattern was printed at high speed (450 m/min) on the PE film of each group of composite sheets for packaging using the aqueous ink compositions 1 to 3 prepared in examples 1 to 3 and comparative examples 1 to 2, the comparative aqueous ink composition 1 and the solvent-based ink composition 1, respectively, to prepare 5 groups of composite sheets for packaging each of 200 sheets. Each of the composite sheets for packaging has a size of 200mm x 150mm x 0.4mm, respectively, and each includes a paper support layer and a PE film of 0.1mm thickness laminated on the support layer. After the printed patterns are completely dried, each group of 200 packaging composite sheets are sequentially stacked into 4 stacks with the same height in a mode that the printed surfaces face the non-printed surfaces, and each stack comprises 50 sheets. Each set of 4 stacks of composite sheets was placed in turn on a conveyor belt moving at a speed of 1m/min, the relative movement of the individual composite sheets in each stack was visually observed after 5m of movement, and the average relative movement distance of the uppermost sheet relative to the lowermost sheet was measured using a ruler. The results are shown in Table 9 below.

Table 9: test results of anti-skid Property

As can be seen from the above test examples, the aqueous ink composition of the embodiments of the present disclosure can print a pattern layer on a plastic material (e.g., polyolefin group) at high speed. The aqueous ink composition of the embodiments of the present disclosure has good printing effect, release property and anti-slip property when used for printing a plastic material such as a PE film.

The above description is intended to be exemplary of the present disclosure, and not to limit the scope of the present disclosure, which is defined by the claims appended hereto.

Claims

1. An aqueous ink composition for printing plastic materials comprising:

a water-based acrylic resin;

an aqueous urethane acrylate resin;

a pigment; and

an aqueous solvent.

2. The aqueous ink composition of claim 1, further comprising one or more of the following:

a cosolvent;

a dispersant;

a pH adjusting agent;

leveling agent; and

and (4) defoaming agent.

3. The aqueous ink composition of claim 2, comprising, based on the total weight of the aqueous ink composition:

10 to 20 weight percent of a water-based acrylic resin;

15 to 35 weight percent of water-based urethane acrylate resin;

10 to 25 wt% of a pigment;

4 to 5 wt% of a co-solvent;

1 to 6 wt% of a dispersant;

0.5 to 2 wt% of a pH adjusting agent;

0.1 wt% to 1 wt% of a leveling agent;

0.1 to 2 wt% of a defoamer; and

the aqueous solvent to make up to 100% by weight.

4. The aqueous ink composition according to claim 3, wherein the aqueous acrylic resin has a solid content of 40 to 45 wt%, an acid value of 50 to 100mgKOH/g, and a glass transition temperature of 20 to 60 ℃;

the waterborne polyurethane acrylate resin is anionic, the solid content of the waterborne polyurethane acrylate resin is 30 to 50 weight percent, the pH value is 7.5 +/-1, the elongation at break is more than or equal to 500 percent, and the tensile strength is more than or equal to 25kg/cm ² 。

5. The aqueous ink composition according to claim 3, wherein the pigment is an inorganic pigment.

6. The aqueous ink composition according to claim 3, wherein the aqueous solvent is water.

7. The aqueous ink composition according to claim 3, wherein the co-solvent is one or more selected from the group consisting of ethanol, n-propanol and isopropanol.

8. The aqueous ink composition according to claim 3, wherein the pH adjuster is one or more selected from the group consisting of ammonia, ethylamine, diethylamine, triethylamine, monoethanolamine, diethanolamine and triethanolamine.

9. The aqueous ink composition according to any one of claims 3 to 8, comprising, based on the total weight of the aqueous ink composition:

15 to 20 weight percent of water-based acrylic resin;

30-35 wt% of water-based urethane acrylate resin;

10 to 12 wt% of a pigment;

4.5 wt% to 5 wt% of a co-solvent;

2 to 5 wt% of a dispersant;

0.5 to 1.5 wt% of a pH adjusting agent;

0.5 wt% to 1 wt% of a leveling agent;

0.1 to 0.2 wt% of a defoamer; and

water to make up to 100 wt%.

10. A plastics material having a design layer printed with an aqueous ink composition, wherein the design layer comprises:

acrylic resin;

a urethane acrylate resin; and

a pigment.

11. The plastic material of claim 10, wherein the pattern layer further comprises one or more of:

a dispersant;

a pH adjusting agent;

leveling agent; and

and (4) defoaming agent.

12. The plastic material of claim 10, wherein the plastic material is a polyethylene film.

13. The plastic material according to claim 10, wherein, when measured using a flat surface coefficient of friction meter under conditions of 200g load, 100mm/min speed, 0-5N test force and 0-80 ℃,

the static friction coefficient of the plastic material is 0.37 to 0.47 of the printing surface and 0.45 to 0.55 of the printing surface and the non-printing surface;

the plastic material has a dynamic coefficient of friction of 0.25 to 0.35 on the printed side and 0.35 to 0.45 on the non-printed side.

14. A plastics material as claimed in claim 13 wherein more than one piece of the plastics material is mixed at 3kg/cm ² And a temperature of 45 ℃ for 24 hours, without blocking of the printing side of said plastic material.

15. A method of preparing an aqueous ink composition for printing plastic materials, wherein the aqueous ink composition comprises:

a water-based acrylic resin;

an aqueous urethane acrylate resin;

a pigment; and

an aqueous solvent;

the method comprises the following steps:

1) uniformly mixing the water-based acrylic resin with the pigment;

2) adding a part of the aqueous urethane acrylate resin into the mixture prepared in the step 1);

3) adding a portion of the aqueous solvent to the mixture prepared in step 2);

thereby preparing the aqueous ink composition.

16. The method of claim 15, wherein the aqueous ink composition further comprises one or more of: cosolvent, dispersant, pH regulator, leveling agent and defoaming agent.

17. The method of claim 16, wherein the adding a portion of the aqueous solvent to the mixture prepared in step 2) comprises:

uniformly mixing a part of the aqueous solvent with one or more of the cosolvent, the dispersant, the pH regulator and the defoaming agent, and then adding the mixture into the mixture prepared in the step 2).

18. The method of claim 16 wherein the leveling agent is added after step 4) and before, after, or simultaneously with step 5).

19. The production method according to any one of claims 15 to 18, wherein the aqueous ink composition includes:

15 to 20 weight percent of a water-based acrylic resin;

30 to 35 weight percent of aqueous urethane acrylate resin;

10 to 12 wt% of a pigment;

4.5 wt% to 5 wt% of a co-solvent;

2 to 5 wt% of a dispersant;

0.5 to 1.5 wt% of a pH adjusting agent;

0.5 wt% to 1 wt% of a leveling agent;

0.1 to 0.2% by weight of a defoaming agent, and

water to make up to 100 wt%.

20. Use of the aqueous ink composition according to any one of claims 1 to 9 for printing plastic materials.

21. A package comprising a plastics material as claimed in any one of claims 10 to 14.