KR20020057445A - The product of nonconducting black water ink - Google Patents

Abstract

PURPOSE: Provided is a non-conductive aqueous black ink composition excellent in blackness, light fastness, and water resistance, which dose not generate sparks when high frequency laminating. CONSTITUTION: The non-conductive aqueous black ink composition comprises: 5-70wt% of a water-soluble or water-dispersible resin such as a poly vinyl alcohol, a vinyl acetate resin, a polyurethane resin, an acryl resin, and etc.; 10-70wt% of black iron oxide as a coloring agent containing more than 90% of Fe2O3; 0.3-20wt% of a water-soluble dispersing agent; 2-20wt% of a solvent comprising water or a mixture of the water and a water-soluble organic solvent.

Description

Non-conductive black water ink composition {The product of nonconducting black water ink}

In the aqueous ink for flexo or gravure printing provides an aqueous black ink composition that is excellent in coloration, light resistance, and water resistance, and does not generate sparks during high-frequency laminating adhesion.

[TECHNICAL FIELD OF THE INVENTION]

It is a non-conductive black aqueous ink that is printed on paper or synthetic film in a flexo or gravure method. It is characterized in that no spark is generated when irradiating and laminating high frequency on the printing part when processing various packaging containers.

[Technical Field of the Invention]

Conventionally, aqueous black ink was prepared using a pigment or a dye as a colorant, and as a black pigment, carbon black was used as a main raw material.

However, the ink made of carbon black has been limited in its use as a high frequency ink because of its high safety risks such as sparking in the printing area due to the conductivity of carbon itself during high frequency irradiation and its inadequate damage to the product.

On the other hand, a black aqueous ink was prepared by mixing three or more kinds of pigments described in the following examples, mainly composed of organic pigments.

As the organic pigment used,

C.I.Pigment Yellow 1,2,3,5,12,13,14,17,83 etc

C.I.Pigment Orange 1,5,13,16,17,24 etc

C.I.Pigment Red 1,2,3,4,5,7,9,12,22,23,37,38,48,49,50,51,53,57,88,

112,214, etc.

C.I.Pigment Blue 1,2,15,16,17, etc.

C.I. Pigment Green 7 and the like.

Also, if you give an example of use as a dye,

C.I. Acid Black 1,2,24,26,31,52,107,109,110,119,154 etc

C.I. Direct Black 17,19,22,32,38,51,56,74,75,77,154,168

C.I. Basic dyes, such as Basic Black 2, were used alone or in combination.

The dye or pigment was used in the range of 2 to 30% by weight, and black ink was formed by appropriately mixing a water-soluble resin, a water-soluble organic solvent, a dispersant, an antifoaming agent, a preservative, and a flow control agent.

Black ink with colored pigment combinations decreased coloration, density, and light resistance.

Ink prepared as a dye has poor printability due to lack of water resistance, light resistance, etc., and high permeability and diffusivity on printing paper.

The present invention relates to an aqueous black ink composition which solves the problems raised in the conventional manufacturing techniques of the organic pigment combination type and dye type ink, and has excellent coloring power and no problems such as sparking during water-resistant, light-resistant and high frequency laminating adhesion processing.

As a result of repeated researches on the conventional technical phenomena, a black non-conductive aqueous ink composition having excellent colorability, water resistance, light resistance, etc. was found when a specific pigment and resin were used.

That is, the present invention provides the following aqueous ink composition.

a) 5 to 70% of water-soluble or water-dispersible resin component

b) 10 to 70% by weight of black iron oxides of the Fe ₂ O ₃

c) 0.3-20 wt% of water-soluble dispersant

d) Aqueous ink composition, characterized in that composed of 2 to 20% by weight, consisting of water or a water-soluble organic solvent and a mixture, all expressed by "%" means by weight.

In the present invention, the resin component is a water-soluble or water-dispersible organic synthetic polymer that facilitates the formation of a coating film of ink, and is an essential element for preventing ink bleeding of the printed portion even under severe conditions with water such as water deposition.

As such resin components, water-soluble and water-dispersible resins such as polyvinyl alcohol, styrene-maleic acid resin, vinyl acetate resin, polyurethane resin, acrylic resin, styrene-acrylic copolymer resin, alkyd resin, polyvinylpyrrolidone, cellulose-based resin, etc. Or mixed use is possible. The effective amount is preferably in the range of 5 to 70%.

When the resin content is less than this, adhesion, abrasion resistance, and water resistance are inferior. When the resin content is excessive, the viscosity becomes high and the printability is inferior.

As the colorant, black iron oxide of the main formula Fe ₂ O ₃ is an essential element.

A content of 90% or more of Fe ₂ O ₃ is preferred for obtaining the effect of the present invention, and commercially available black iron oxide contains a small amount of Fe ₃ O ₄ and Fe (OH) ₂ . These are electrically non-conductors and do not dissolve in water or organic solvents, and are excellent in light resistance and weather resistance.

When the amount is too small, it is not preferable because the coloration is low, and when the amount is excessively used, dispersibility is not sufficient, and water resistance and printability due to poor fluidity of ink and relatively low resin content are inferior.

The water-soluble dispersant is used for the purpose of improving the dispersion stability between the pigment and the resin, preventing precipitation and reaggregation of the pigment, improving the storage stability of the ink, and the smoothness of the ink coating film during printing.

Examples thereof include polyoxyethylene glycol fatty acid esters (polyoxyethylene mono tm terate, polyoxyethylene glycol diisostearate, etc.) polyoxyethylene alkyl phenyl ethers (polyoxyethylene nonyl phenyl ether, polyoxy ethylene octyl phenyl ether, etc.) ) Polyoxy ethylene sorbitan fatty acid ester (polyoxy ethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate) and the like are suitable.

In addition, other anionic surfactants, cationic surfactants, and nonionic surfactants can be used. In this case, single or two or more kinds can be used. It is preferable to use these in 0.3 to 20% of range.

When the amount is less than the amount used, the dispersibility of the pigment becomes poor, and the smoothness decreases, and the stability with time develops.

In addition, excessive use is not suitable due to water resistance, dryness, poor weatherability and severe bleeding of the ink.

As a solvent component, the following are mentioned as an example of water or a water affinity organic solvent.

Methanol, ethanol, isopropanol, butanol, ethylene glycol, diethylene glycol, glycerin, propylene glycol, ethylene glycol monomethyl ether, dietylene glycol monomethyl ether, ethylene glycol isopropyl ether, diethylene glycol isopropyl ether, ethylene glycol Alkyl groups (methyl, ethyl, isopropyl, butyl, isobutyl) substituted esters such as monobutyl ether, diethylene glycol monobutyl ether, propylene or dipropylene glycol are suitable.

In the case of using a mixture of water and a water-soluble organic solvent, the latter ratio is preferably up to 60% of the weight of the mixture, preferably about 30%.

When the ratio of the organic solvent is 60% or more, precipitation of water-soluble or water-dispersible resins or dispersants used as ink binders may occur, thereby accelerating resin and pigment precipitation.

The role of the organic solvent in the ink composition affects the drying speed of the ink, permeability, moisture retention, and smoothness of the coating film, and the selection and use ratio thereof may vary depending on the type of resin dispersant, but is usually about 2 to 20%. .

When the amount of the organic solvent component is too small, the effect cannot be exerted properly. When the amount is too large, the viscosity decreases, the drying speed of the ink is unsuitable, and the coloration of the ink cannot be properly exhibited.

In the present invention, an appropriate amount of an aqueous ink additive commonly used may be used as necessary.

As such additives, preservatives, rust inhibitors, defoamers, thickeners, slippering agents and the like are used.

Example 1

Iron Oxide Black 318 50.0%

(Black iron oxide, Germany Bayer company make)

Monopol NP-1019 4.0%

(Polyoxyethylene Nonylphenyl Ether, Southeast Synthetic Chemical Co., Ltd.)

Joncryl 67 solution 10.0%

(30% alkaline aqueous solution of styrene acrylic copolymer resin, manufactured by Johnson Polymers, USA)

7.0% of water

Ethylene Glycol 6.0%

The components were dispersed three times in a dynomil to have a particle size of 10 microns or less, and then the following components were mixed and flexographic ink-ized.

Joncryl 74 23.0%

(48% styrene acrylic copolymer resin solid content, manufactured by Johnson Polymers, USA)

Example 2

Iron Oxide Black 318 50.0%

(Black iron oxide, Germany Bayer company make)

Monopol NP-1019 4.0%

(Polyoxyethylene Nonylphenyl Ether, Southeast Synthetic Chemical Co., Ltd.)

Joncryl 67 solution 10.0%

(30% alkaline aqueous solution of styrene acrylic copolymer resin, manufactured by Johnson Polymers, USA)

Isopropyl Alcohol 13.0%

The components were dispersed three times in dynomil to have a particle size of 10 microns or less, and then the following components were mixed and gravure inked.

Joncryl 74 23.0%

(48% styrene acrylic copolymer resin solid content, manufactured by Johnson Polymers, USA)

Comparative Example 1

C.I Acid Black 2 10.0%

Monopol NP-1019 2.5%

(Polyoxyethylene Nonylphenyl Ether, Southeast Synthetic Chemical Co., Ltd.)

Ethylene Glycol 15.0%

Propylene Glycol 10.0%

62.5% of water

The components were mixed and stirred for 2 hours to flexo ink.

Comparative Example 2

C.I Acid Black 2 10.0%

Monopol NP-1019 2.5%

(Polyoxyethylene Nonylphenyl Ether, Southeast Synthetic Chemical Co., Ltd.)

Ethylene Glycol 10.0%

Propylene Glycol 10.0%

Methanol 67.5%

The ingredients were mixed and stirred for 2 hours to gravure ink.

Comparative Example 3

Yellow D525 3.0%

(C.I Pigment Yellow 12, manufactured by Daehan Swiss Chemical Co., Ltd.)

Red 4BL 5.0%

(C.I Pigment Red 57: 1, manufactured by Daehan Swiss Chemical Co., Ltd.)

Blue 8500 5.0%

(C.I Pigment Blue 15: 3, manufactured by Daehan Swiss Chemical Co., Ltd.)

Monopol NP-1019 3.0%

(Polyoxyethylene Nonylphenyl Ether, Southeast Synthetic Chemical Co., Ltd.)

Joncryl 67 solution 10.0%

(30% aqueous solution of styrene acrylic copolymer resin, manufactured by Johnson Polymers, USA)

Ethylene Glycol 6.0%

12.0% of water

The components were dispersed three times in dynomil to have a particle size of 10 microns or less, and the following components were mixed and flexographic ink-ized.

Joncryl 74 56.0%

(Styrene acrylic copolymer resin, solid content 48%, manufactured by Johnson Polymers, USA)

[Comparative Example 4]

Yellow D525 3.0%

(C.I Pigment Yellow 12, manufactured by Daehan Swiss Chemical Co., Ltd.)

Red 4BL 5.0%

(C.I Pigment Red 57: 1, manufactured by Daehan Swiss Chemical Co., Ltd.)

Blue 8500 5.0%

(C.I Pigment Blue 15: 3, manufactured by Daehan Swiss Chemical Co., Ltd.)

Joncryl 67 solution 10.0%

(30% aqueous solution of styrene acrylate copolymer resin, manufactured by Johnson Polymers, USA)

Isopropyl alcohol 20.0%

The components were dispersed three times in a dynomil to have a particle size of 10 microns or less, and then the following components were mixed and gravure inked.

Joncryl 74 54.0%

(48% styrene acrylic copolymer resin solid content, manufactured by Johnson Polymers, USA)

Flexo aqueous black ink prepared according to Example 1 and Comparative Examples 1 and 3 was subjected to flexo printing on a white kraft paper having a basis weight of 80 g / m 2 under a printing machine condition of 150 lines / inch of anilox roll and a rubber roll hardness of 50 degrees. The test piece was taken under natural conditions for 24 hours in an atmosphere of ± 1 ° C and 65% RH humidity.

For reference, Comparative Examples 1 and 3 are production inks by conventional general-purpose techniques.

Gravure water-based black ink prepared according to Example 2 and Comparative Examples 2 and 4 was subjected to gravure printing on a white kraft paper having a basis weight of 80 g / m 2 under a printing condition of a cylinder line of 170 lines / inch, followed by a temperature of 20 ± 1 ° C. and a humidity of 65% RH. What was naturally dried in the atmosphere for 24 hours was taken as a test piece.

For reference, Comparative Examples 2 and 4 are production inks by conventional general-purpose techniques.

※ Under display : Good X: Indicates bad.

Water resistance test: After filling the transparent glass beaker with water of PH7.0 ± 0.2, the specimen cut to 5cm width and 10cm length was immersed for 24 hours under the condition of water temperature 20 ± 1 ℃, and the bleeding phenomenon of ink was compared. .

Light resistance: Weather- test specimen After 96 hours exposure to Xenon lamp using -meter, the degree of discoloration was compared.

Blackness: The test pieces were visually observed and blackness was compared.

Conductivity: Conductivity was checked as a commercial electric tester.

As described above, the ink of the present invention can be used as an ink for flexographic and gravure printing of improved physical properties compared to conventional products having excellent blackness, water resistance, light resistance, and no electrical conductivity.

In addition, a printed product printed on white graft paper having a basis weight of 80 g / m 2 as the ink of Examples 1 and 2 was subjected to high-frequency laminating adhesion with a transparent polyethylene film having a film thickness of 25 microns to obtain a high-quality product without sparking.

Claims (2)

In an aqueous black ink composition comprising a pigment and a water-soluble organic solvent, a water-soluble resin, a dispersant, water, etc., an aqueous black ink composition which does not generate sparks when high-frequency laminating is mainly made of a pigment having a formula of Fe ₂ O ₃ or more. . The black aqueous ink of the present invention includes a flexographic ink for gravure printing.