AU2018344119A1 - Electron beam-curable water-based flexo ink for surface printing and boilable/retort pouch using same - Google Patents

Electron beam-curable water-based flexo ink for surface printing and boilable/retort pouch using same Download PDF

Info

Publication number
AU2018344119A1
AU2018344119A1 AU2018344119A AU2018344119A AU2018344119A1 AU 2018344119 A1 AU2018344119 A1 AU 2018344119A1 AU 2018344119 A AU2018344119 A AU 2018344119A AU 2018344119 A AU2018344119 A AU 2018344119A AU 2018344119 A1 AU2018344119 A1 AU 2018344119A1
Authority
AU
Australia
Prior art keywords
water
electron beam
ink
printing
curable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
AU2018344119A
Other versions
AU2018344119B9 (en
AU2018344119B2 (en
Inventor
Tsutomu Haruyama
Toshinori Ishibashi
Shigeki Itou
Nobuo SAWATARI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
DIC Graphics Corp
Original Assignee
DIC Graphics Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by DIC Graphics Corp filed Critical DIC Graphics Corp
Publication of AU2018344119A1 publication Critical patent/AU2018344119A1/en
Application granted granted Critical
Publication of AU2018344119B2 publication Critical patent/AU2018344119B2/en
Publication of AU2018344119B9 publication Critical patent/AU2018344119B9/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D33/00—Details of, or accessories for, sacks or bags
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C09D11/10—Printing inks based on artificial resins
    • C09D11/101—Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C09D11/10—Printing inks based on artificial resins
    • C09D11/102—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Inks, Pencil-Leads, Or Crayons (AREA)
  • Bag Frames (AREA)
  • Packages (AREA)
  • Wrappers (AREA)

Abstract

The present invention addresses the problem of providing a boilable retort pouch that is surface printed using an electron beam-curable water-based flexo ink for surface printing on the outside of the pouch container, wherein the amount of VOC in the ink is almost 0% and the ink has an excellent abrasion resistance and an excellent boilability and retortability. The electron beam-curable water-based flexo ink for surface printing contains a water-based resin (X), an ethylenic double bond-bearing electron beam-curable compound (Y), a pigment, and water, and is characterized in that the mass ratio between the solids fraction of the water-based resin (X) and the solids fraction of the ethylenic double bond-bearing electron beam-curable compound (Y) is within the range of (X)/(Y) = 5/100 to 400/100.

Description

DESCRIPTION Title of Invention: ELECTRON BEAM-CURABLE WATER-BASED FLEXO INK FOR SURFACE PRINTING AND BOILABLE/RETORT POUCH USING SAME Technical Field [0001]
The present invention relates to an exclusively surface-printing water-based flexo ink that can be used for water-based flexography equipped with electron beam-curable equipment, and to a boilable/retort pouch made therewith. Background Art [0002]
Water-based flexography has been widely used to give esthetics and functionality to printed articles.
In recent years, changes in lifestyle in recent years, such as increases in the number of double-income families and the number of one-person households, have caused the consumption of food pouches, including gas-filled pouches for snacks packaging, heat-resistant boilable pouches, and heat- and pressure-resistant retort pouches, in particular the consumption of boilable/retort food pouches, to increase year by year.
Examples of boilable/retort pouches include packaging for solid and liquid foods such as curries, hamburgers, pasta sauces, soups, and toppings for rice bowls. Boilable pouches are subjected to heating, for example at temperatures of about 90°C to 98°C for about 30 to 60 minutes. Retort pouches are subjected to heating and pressurization, for example heating at temperatures of about 110°C to 130°C for about 20 to 60 minutes under pressure.
Inks for boilable/retort pouches therefore are required to withstand the above heat and pressure tests and also to have durability, such as abrasion resistance to prevent the print from being damaged during transportation/storage. Currently available boilable/retort pouches are generally made using laminate packaging, i.e., a laminate of materials back-printed with solvent inks and joined together using a solvent adhesive, but as people are becoming more conscious about safety to food and about the environment, expectations are emerging for a turn to packaging materials with a safer and less eco-harmful configuration. [0003]
To address such demands, packaging materials made with a water-based ink and a solventless adhesive have been proposed. The fact, however, is that a water-based ink, made using hydrophilic raw materials, and a solventless adhesive fail to achieve sufficient adhesive strength and cannot supersede the known configuration of a solvent ink/a solvent adhesive.
Moreover, whatever the combination is, i.e., whether the ink is water-based or solvent-based and whether the adhesive is solvent-based or solventless, lamination is required after back printing to ensure the durability, such as abrasion resistance, of the ink. This means an aging step after lamination is essential, and the printed material cannot proceed to processing and filling steps immediately. The known, back-printed boilable/retort packaging has their limitations in terms of expediting delivery to customers. [0004]
Inventions have been made that indicate high energy beam-curable water-based compositions made up of water and a water-soluble compound containing an a,β-ethylenic unsaturated radiation-polymerizable double bond, but these are by no means sufficient in terms of abrasion resistance and boilability/retortability, which is deemed essential for retort pouches (e.g., PTL 1 to 3). Citation List Patent Literature [0005]
PTL 1: Japanese Unexamined Patent Application Publication No. 2003-147001
PTL 2: Japanese Unexamined Patent Application Publication No. 2003-147230
PTL 3: Japanese Unexamined Patent Application Publication No. 2008-150610
Summary of Invention Technical Problem [0006]
The problem to be solved, by the present invention is to provide a boilable/retort pouch for which the ink contains substantially 0% VOCs (Volatile Organic Compounds) and that has been surface-printed on its outer container surface with an electron beam-curable surface-printing water-based flexo ink, which is superior in abrasion resistance and boiling/retort suitability. Solution to Problem [0007]
After extensive research to solve the above problem, the inventors have found that the problem can be solved by adding a pigment and water to a resin and an electron beampolymerizable compound especially preferred for the formulation of exclusively surface-printing water-based flexo inks that can be used for water-based flexography equipped with electron beam-curable equipment. The present invention was completed on the basis of these findings. [0008]
The present invention is a discovery of the fact that even in water-based flexography, the use of an electron beam (EB)-curable water-based ink, which is superior in waterproofness, heat resistance, abrasion resistance, etc., for surface printing of boilable/retort pouches provides a solution to the above problem. That is, laminated printing paper is prepared in advance, and printing is done on the surface of the paper immediately after an order is placed. Since an electron beam (EB)-curable water-based ink forms a strong coating upon EB irradiation, the printed material can proceed to filling and processing steps immediately after the end of the printing step. This enables expedited delivery of boilable/retort packaging to customers.
[0009]
That is, the present invention relates to an electron beam-curable surface-printing water-based flexo ink that contains a water-based resin (X), at least one electron beam-polymerizable compound having an ethylenic double bond (Y) , at least one pigment, and water. The ratio by mass between the solids content of the water-based resin (X) and that of the electron beam-polymerizable compound having an ethylenic double bond (Y) is in the range of (X)/(Y) = 5/100 to 400/100. [0010]
The present invention also relates to an electron beamcurable surface-printing water-based flexo ink in which the electron beam-polymerizable compound having an ethylenic double bond (Y) is a water-soluble (meth)acrylic monomer and/or a water-soluble (meth)acrylic oligomer.
[0011]
The present invention also relates to an electron beamcurable surface-printing water-based flexo ink in which the electron beam-polymerizable compound having an ethylenic double bond (Y) is polyethylene glycol di(meth)acrylate. [0012]
The present invention also relates to an electron beamcurable surface-printing water-based flexo ink in which the water-based resin (X) is a nonreactive water-based urethane resin . [0013]
The present invention also relates to an electron beamcurable surface-printing water-based flexo ink in which the energy intensity of the electron beam is between 30,000 and 300,000 eV, and the irradiation dose of the electron beam is between 5 and 100 kGy-m/min. (kilogray). [0014]
The present invention also relates to a printed article that includes a plastic film and an electron beam-curable surface-printing water-based flexo ink as described above applied thereto using a flexographic printer. [0015]
The present invention, moreover, relates to a multilayer material that includes the resulting printed article and a substrate laminated together using a lamination adhesive and is suitable particularly for use in, for example, boilable pouches and retort pouches, which need to have heat resistance and waterproofness.
Advantageous Effects of Invention [0016]
The electron beam-curable surface-printing water-based flexo ink according to the present invention contains 0% VOCs and, when used for printing on the outer container surface of a retort pouch, gives a boilable/retort pouch superior in boiling/retort suitability, such as abrasion resistance, waterproofness, and heat resistance. Description of Embodiments [0017]
An electron beam-curable surface-printing water-based flexo ink according to the present invention is an electron beam-curable surface-printing water-based flexo ink that contains a water-based resin (X), at least one electron beam-polymerizable compound having an ethylenic double bond (Y) , at least one pigment, and water. The ratio by mass between the solids content of the water-based resin (X) and that of the electron beam-polymerizable compound having an ethylenic double bond (Y) is in the range of (X)/(Y) = 5/100 to 400/100. [0018]
Here is described the simplest layer structure of retort-pouch packaging.
The best-known layer structure in the related art is a composite film, for example obtained by joining aluminum foil to substrate polypropylene film using an adhesive and then joining the aluminum foil to polyethylene terephthalate (hereinafter also referred to as PET) film.
If the composite film has a print layer, the order is usually PET film/a solvent-based back-printing ink layer/an adhesive layer (aging required)/an aluminum foil or deposited aluminum film layer/adhesive layer/polypropylene substrate film, from the top layer (Hereinafter the layers down to PET film/a solvent-based back-printing ink layer may be referred to as the upper layers, and the layers down to an aluminum foil or deposited aluminum film layer/an adhesive layer/polypropylene substrate film may be referred to as the lower layers.), and the composite film is produced typically by back-printing on PET film using a solvent-based back-printing ink, then applying an adhesive, and joining the workpiece and aluminum foil or deposited aluminum film together. A highly functional film available as an integrated form of the lower layers, i.e., an aluminum foil or deposited aluminum film layer/an adhesive layer/polypropylene substrate film, may occasionally be used. The polypropylene substrate film in the lower layers is not essential and may be replaced with another olefin film.
A typical processing procedure is: After back printing with a solvent-based back-printing ink, an adhesive is applied, the workpiece is laminated with the other necessary film(s), the laminate is optionally aged to give a composite film, and the composite film is shaped into a bag to give a retort-pouch package. Filling step it with its content will make it retort-pouch packaging.
[0019]
The electron beam-curable surface-printing water-based flexo ink according to the present invention is an exclusively surface-printing water-based flexo ink that can be used in the layer structure formed by an electron beamcurable water-based ink layer/a PET film layer/an adhesive layer/an aluminum foil or deposited aluminum film layer/an adhesive layer/polypropylene substrate film, in order from the top layer. This enables printing with an electron beamcurable water-based ink on the PET surface of a multilayer film prepared beforehand as a laminate of the layers down to a PET film layer/an adhesive layer/an aluminum foil or deposited aluminum film layer/an adhesive layer/polypropylene substrate film. [0020]
If a solvent-based back-printing ink and an adhesive are used as in the related art, the printing and lamination steps involve the emission of VOCs in drying steps. The combination of a water-based flexo ink and a solventless adhesive helps reduce VOC emissions but fails to achieve sufficient adhesive strength because the binder in the ink used is a water-based resin. Furthermore, whatever the types of the ink and adhesive, a packaging material made by back printing/lamination requires an aging step and therefore is time-consuming and is inferior in productivity.
In the present application, by contrast, printing can be done on the surface of a multilayer film prepared beforehand as a laminate of all layers excluding the print layer and using an electron beam (EB)-curable surfaceprinting water-based ink, which is superior in waterproofness, heat resistance, and abrasion resistance. The process from printing to bag making and filling is therefore significantly expedited compared with the known production process for a packaging material, which has a lamination step after back printing.
Besides the expedited delivery to customers and reduced inventory owing to such a reduction in process time, the present application can lead to a considerable amount of cost-cutting by the use of fewer layers and volume reduction. Furthermore, flexography helps achieve higher productivity with its high-speed printing capability.
In addition, further coating the surface-print layer, to which the electron beam-curable surface-printing waterbased flexo ink has been placed, with an electron beam (EB)curable overprint varnish layer, for example using a roll coater, and then curing the varnish layer with an electron beam (EB) would help further improve characteristics such as abrasion resistance/surface glossiness.
[0021]
The electron beam-curable surface-printing water-based flexo ink according to the present invention is intended for the application of surface printing on the outer container surface of retort pouches. To combine abrasion resistance, waterproofness, heat resistance, and other qualities required as boiling/retort suitability, the ink contains a water-based resin (X) as an essential ingredient.
Preferred examples of water-based resins (X) include aqueous solutions of or dispersed (emulsions or dispersions of) resins made from binder resins that are copolymers of acrylic or methacrylic acid and its alkylate, styrene, etc., as primary monomer components, such as water-based acrylic resins, water-based styrene-acrylic resins, water-based styrene-maleic acid resins, water-based styrene-acrylicmaleic acid resins, water-based polyurethane resins, and water-based polyester resins. The resin (X) can be urethane-resin beads, such beads dispersed in an aqueous solvent (Also referred to as a dispersion. Materials such as urethane-resin dispersions and aliphatic polyurethane dispersions are included), or a water-based aliphatic polyurethane dispersion. Of these resins, aqueous polyurethane resins are particularly preferred for the reasons of, for example, adhesion to substrates and suitability for long-run printing.
Moreover, for the reasons of the odor of the ink made with it and migration as a packaging material, it is preferred that the water-based resin (X) be a nonreactive water-based urethane resin. It may be used in mixture with a reactive water-based urethane resin having a (meth)acryloyl group. The water-based resin (X) may be a commercially available one. In that case, it is available as a dispersion or emulsion of a water-based resin. [0022]
The electron beam-curable surface-printing water-based flexo ink according to the present invention contains an electron beam-polymerizable compound having an ethylenic double bond (Y) as an essential ingredient. The electron beam-polymerizable compound having an ethylenic double bond can be a known electron beam-curable monomer or oligomer, but preferably it is a water-soluble (meth)acrylic monomer or water-soluble (meth)acrylic oligomer to ensure solubility in water.
Specific examples of water-soluble (meth)acrylates include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, N-(2-hydroxyethyl) acrylamide (abbreviation: HEAA), N-(2-hydroxyethyl) methacrylamide, N-(2hydroxymethyl) acrylamide, N-(2-hydroxymethyl) methacrylamide, acryloylmorpholine, methylolacrylamide, dimethylacrylamide, methoxymethylacrylamide, diethylacrylamide, isopropylacrylamide, and polyethylene glycol di(meth)acrylate, but are not limited to these.
[0023]
Examples of water-soluble (meth)acrylic oligomers include CN549, CN131, CN131B, CN2285, CN 3100, CN3105, CN132, CN133, and CN 132 (Sartomer), Ebecryll40, Ebecryl 1140, Ebecryl 40, Ebecryl 3200, Ebecryl 3201, and Ebecryl 3212 (Cytec Industries), PROTOMER 3660, PROTOMER 5006F, PHOTOMER 5429, and PHOTOMER 5429F (Cognis), and LAROMER PO 33F, LAROMER PO 43F, LAROMER PO 94F, LAROMER UO 35D, LAROMER PA 9039V, LAROMER PO 9026V, LAROMER 8996, LAROMER 8765, and LAROMER 8986 (BASF).
Water-soluble (meth)acrylic monomers and water-soluble (meth)acrylic oligomers may be used alone or in mixture. In particular, polyethylene glycol di(meth)acrylate is preferred.
[0024]
In the electron beam-curable surface-printing waterbased flexo ink according to the present invention, the ratio by mass between the solids content of the water-based resin (X) and that of the electron beam-polymerizable compound having an ethylenic double bond (Y) needs to be in the range of (X) /(Y) = 5/100 to 400/100.
More desirably, (X)/(Y) = 7/100 to 250/100. Even more desirably, the ratio is in the range of (X)/(Y) = 7/100 to 50/100. The most desirably, the ratio is in the range of (X)/(Y) = 7/100 to 25/100.
Regarding this ratio by mass, water-based resins are effective in imparting flexibility to the ink coat irradiated with an electron beam and improving the coat's adhesion to the substrate, but if the proportion of the water-based resin component is high, concern tends to be high about incomplete curing, poor abrasion resistance, poor heat resistance, poor waterproofness, etc., as a result of a low concentration of double bonds in the ink paint.
If the water-based resin (X) is a commercially available one, it is a dispersion or emulsion of a waterbased resin in most cases. In this case, the dry solids content of the dispersion or emulsion of a water-based resin is used.
[0025]
Examples of pigments used in the electron beam-curable surface-printing water-based flexo ink according to the present invention include organic or inorganic pigments and dyes used in ordinary inks, paints, recording agents, and the like.
[002 6]
The organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine-azo, diketopyrrolopyrrole, isoindoline, and other pigments. [0027]
The inorganic pigments include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, red iron oxide, aluminum, mica, and others. Besides these, shiny pigments that are glass flakes or lump flakes as the base material with a coating of metal or metal oxide thereon (Metashine; Nippon Sheet Glass Co., Ltd.) can be used. It is preferred, because of cost and tinctorial strength, to use titanium oxide for white ink, carbon black for black ink, aluminum for gold or silver ink, and mica for pearl ink. Aluminum is in powder or paste form, but preferably it is used in paste form for ease of handling and safety reasons. Whether to use leafing or non-leafing aluminum is selected as appropriate in light of brightness felt and density.
As for the total of the pigment(s), it is preferred that the pigment(s) be contained in an amount sufficient to ensure the density and tinctorial strength of the ink, i.e., at a percentage of 1% to 50% by mass of the total weight of the ink. Colorants may be used alone or as a combination of two or more.
[0028]
The electron beam-curable surface-printing water-based flexo ink according to the present invention can further contain a solvent and other appropriate auxiliaries.
The solvent can be water alone or a water-miscible organic solvent. Examples of organic solvents include alcohols, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-propyl alcohol, polyhydric alcohols, such as propylene glycol and glycerol, and ethers, such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, and ethyl carbitol. [0029]
As for auxiliary ingredients other than solvents, it is possible to optionally use, for example, waxes and aliphatic amides for imparting abrasion resistance, sliding smoothness, and other qualities, such as paraffin waxes, polyethylene waxes, PTFE waxes, and carnauba wax and oleic acid amide, stearic acid amide, and erucic acid amide, silicone or non-silicone antifoams for controlling foaming during printing, dispersants that improve the wetting of the pigment, and wetting agents that improve wettability on the substrate .
[0030]
The electron beam-curable surface-printing water-based flexo ink relating to the present invention is produced using, for example, equipment that is common in the production of gravure and flexographic inks, such as an Eiger mill, a sand mill, a gamma mill, or an attritor.
For the electron beam-curable surface-printing waterbased flexo ink according to the present invention, its viscosity only needs to be between 5 and 35 seconds, more preferably between 8 and 20 seconds, at 25°C when a Rigo Zahn cup #5 is used. In millipascal-seconds, the viscosity only needs to be in the range of 100 to 1000 (mPa-s) , more preferably in the range of 180 to 600 (mPa-s), at 25°C.
The surface tension at 25°C of the electron beam-curable surface-printing water-based flexo ink according to the present invention is preferably between 25 and 50 mN/m, and it would be more preferred that it be between 33 and 43 mN/m. The wettability of the ink on the substrate, such as film, improves with decreasing surface tension of the ink, but a surface tension lower than 25 mN/m tends to cause a type of dirt on the print surface called dot bridging as a result of the ink spreading to an extent that adjacent dots in halftone-dot areas join together. With a surface tension higher than 50 mN/m, however, the wettability of the ink on the substrate, such as film, is likely to be low; such a surface tension therefore tends to cause repellence.
[0031]
The electron beam-curable surface-printing water-based flexo ink according to the present invention is superior in adhesion to different film substrates and can be used for printing on thermoplastic resin films and plastic products.
Examples of substrate films include films of thermoplastic resins, such as polyamide resins, e.g., nylon (Ny) 6, nylon 66, and nylon 46, polyester resins, e.g., PET polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate, polyhydroxycarboxylic acids, e.g., polylactic acid, biodegradable resins, typified by aliphatic polyester resins, e.g., poly(ethylene succinate) and poly(butylene succinate), polyolefin resins, e.g., PP and polyethylene, polyimide resins, polyarylate resins, and mixtures thereof as well as a stack of such films, but in particular, polyester, polyamide, polyethylene, and polypropylene films are suitable for use. These substrate films may be non-oriented films or oriented films and are not limited to a particular production process. The thickness of the substrate film is not critical either, but usually it only needs to be in the range of 1 to 500 pm.
The print surface of the substrate film has preferably been treated with a corona discharge. Silica or alumina, for example, may have been deposited. [0032]
The electron beam-curable surface-printing water-based flexo ink according to the present invention is an exclusively surface-printing water-based flexo ink that can be used in layer structures formed at least by an electron beam-curable water-based ink layer/a film layer/an adhesive layer/aluminum foil/an adhesive layer/substrate film, in order from the top layer, and the two upper layers, an electron beam-curable water-based ink layer/a film layer, correspond to a surface-printed material produced by film printing. Placing an additional electron beam-curable water-based OP varnish layer on top of the electron beamcurable water-based ink layer helps improve the abrasion resistance and glossiness of the surface of the printed material. The lower layers, aluminum/an adhesive layer/substrate film, may be, for example, a substrate film that has been coated with deposited aluminum in advance or a highly functional film that has a multilayer structure. [0033]
For the electron beam-curable surface-printing waterbased flexo ink according to the present invention, an electron bearm (also referred to as EB) beam, or electrons artificially propelled in an accelerator, is used to cure a coating of the ink on the surface of a printed material produced by printing on a plastic film using a flexographic printer .
In EB curing, the applied layer of ink is formed directly as an ink coat. With an EB-curable composition, which contains no photoinitiator unlike ultraviolet curable, the characteristics of the composition are reflected in those of the ink coat as designed. Once completely polymerized by EB curing, the ink coat is characteristically odorless or of low odor, containing little or no lowmolecular-weight component, such as a photoinitiator.
Additionally, the EB curing treatment seldom causes thermal warping, creasing, deformation, etc., to thin film because the impact of heat on the target of irradiation is small. The EB curing treatment, moreover, provides highspeed processing at a line speed of several 10s to 400 meters per minute or faster, whereas the ultraviolet curing treatment is not as effective if with limited generation of heat. With an UV lamp, furthermore, the light source inevitably ages and loses its luminous intensity with the passage of service time. EB equipment, by contrast, always maintains a constant output power through beam current control.
Preferably, the energy intensity of the electron beam used is between 30,000 and 300,000 eV, and the irradiation dose of the electron beam is between 5 to 100 kGy-m/min. (kilogray).
If the printed film is varnished, for example using a roll coater, to place an additional electron beam-curable water-based OP varnish layer on top of the electron beamcurable water-based ink layer, the ink and OP varnish layers can be simultaneously electron beam-cured with the electron beam.
EXAMPLES [0034]
The following describes the present invention in detail by examples and comparative examples. In the following, all parts and % are by mass.
[0035] (Electron Beam-Curable Surface-Printing Water-Based Flexo Inks; Production Method)
Flexo inks according to the formulae in Table 1 were adjusted as electron beam-curable surface-printing waterbased flexo inks containing a water-based resin (X), electron beam-polymerizable compound(s) having an ethylenic double bond (Y), a pigment, and water.
To take ink 1 as an example, a DIC indigo pigment concentrate (WFJ R507 color indigo concentrate, containing
40% by mass phthalocyanine pigment in a dispersion medium), a nonreactive urethane dispersion, an aliphatic epoxy acrylate, (Laromar LR8765, BASF) polyethylene glycol diacrylate, and an antifoam (BYK-019, BYK) were thoroughly mixed by stirring in accordance with the numbers of parts specified in Table 1. Then the viscosity was adjusted with water to be 12 seconds (25°C) with a Zahn cup #5 (Rigo), completing printing ink (ink 1) . The amount of water is
Balance in the table.
[0036] [Table 1]
(Table 1) Adjustment Examples
Ink 1 Ink 2 Ink 3 Ink 4 Ink 5
Pigment Indigo concentrate (DIG WFJ R507 color indigo concentrate) 35.0 35.0 35.0 35.0
Black concentrate (DIG WFJ R805 black concentrate) 35.0
Water-based resin (X) Nonreactive urethane dispersion (Polyester urethane dispersion, amine-neutralized) 24.8 10.0 24.8 54.8 59.8
Electron beampolymerizable compound(s) having an ethylenic double bond (Y) Urethane acrylate (Daicel water-based UVcurable resin, 35% solids) 14.8
Aliphatic epoxy acrylate (Laromar LR8765, BASF) 20.0 20.0 10.0
Polyethylene glycol diacrylate 20.0 20.0 30.0 10.0 5.0
Additive Antifoam (BYK-019, BYK) 0.2 0.2 0.2 0.2 0.2
Water Balance Balance Balance Balance Balance
Total (parts) 100.0 100.0 100.0 100.0 100.0
[0037]
In the table, abbreviations and similar forms of words represent the following.
Water-based resin (X)
A nonreactive urethane dispersion (nonvolatile content, 39% by mass)
Electron beam-polymerizable compounds having an ethylenic double bond (Y)
Urethane acrylate (a Daicel water-based UV-curable resin, 35% solids)
An aliphatic epoxy acrylate (Laromar LR8765, BASF)
Polyethylene glycol diacrylate Pigments
An indigo concentrate (DIG WFJ R507 color indigo concentrate, containing 40% by mass phthalocyanine pigment in a dispersion medium)
A black concentrate (DIC WFJ R805 black concentrate, containing 40% by mass black-concentrate carbon black [0038] (Printing Method)
A multilayer film for boilable/retort packaging had been prepared beforehand as a laminate formed by coronatreated polyethylene terephthalate (PET) film/an adhesive layer/aluminum foil/an adhesive layer/polypropylene substrate film, in order from the top layer, and surface printing was done with each of inks 1 to 5, obtained by the production method described above, using a CI 6-color flexographic printer (SOLOFLEX, Windmoeller & Hoelscher).
If an EB-curable OP varnish was applied by printing after the surface printing, each ink of inks 1 to 5 as described above was applied first, then a DIG EB-curable OP varnish (WFJ M1000 varnish) was applied by printing, and the ink and varnish were irradiated with an electron beam.
After printing, the film was immediately irradiated with an electron beam with an energy intensity of 80,000 eV at an irradiation dose of 60 kGy-m/min. (kilogray) using EB equipment.
It should be noted that since the irradiation dose varied with the pigment used in the ink, inks 1, 2, 4, and 5, which were made with an indigo concentrate (DIC WFJ R507 color indigo concentrate), were cured with the anilox line count (lines/cm) set to 315 and the cell volume (cm3) to 4.5. Table 2 also summarizes the anilox line count (lines/cm) and cell volume (cm3) used for the black concentrate (DIC WFJ R805 black concentrate) and those for the OP varnish, which contained no pigment.
A printed multilayer film for boilable/retort packaging is hereinafter referred to as a printed multilayer film. [0039] [Table 2]
(Table 2) Ink used Indigo concentrate Black concentrate OP varnish
Anilox line count (lines/cm) 315 315 197
Cell volume (cm3) 4.5 4.5 8.0
[0040] [Test Item 1: Adhesion to a Substrate]
Nichiban 18-mm adhesive tape was stuck firmly to the printed surface of the printed multilayer film, and then the adhesive tape was quickly peeled off perpendicular to the surface. The degree of detachment of the ink was graded visually.
®: No detachment is observed
O: Very minor detachment is observed
Δ: Detachment is observed in part x: The ink detaches in a considerable area [0041] [Test Item 2: Abrasion Resistance]
The printed surface of the printed multilayer film was subjected to an abrasion test using a color fastness rubbing tester (Daiei Kagaku Seiki Mfg.) under the conditions of a load of 200 g and 100 cycles of rubbing. Abrasion resistance was graded by the magnitude of damage to the surface of the ink paint.
The test was conducted as a friction test between portions of the printed surface.
®: There is no damage
O: There is very minor damage
Δ: Damage is observed in a considerable area x: Damage is throughout the test portions [0042] [Test Item 3: Boiling Suitability]
The printed multilayer film was shaped into a pouch with a size of 12 cm x 12 cm, and the pouch was filled with 40 g of simulated food, a mixture of vinegar, salad oil, and meat sauce in a 1:1:1 ratio by weight, tightly sealed, and boiled by immersing it in hot water at 98°C for 60 minutes. Immediately after that, the printed multilayer film was observed for any change in the condition of the print thereon .
®: There is no change
O: The print has changed slightly
Δ: The print has changed in a considerable area x: The entire print has changed [0043] [Test Item 4: Retort Suitability]
The printed multilayer film was shaped into a pouch with a size of 120 mm x 120 mm, and the pouch was filled with 40 g of simulated food, a mixture of vinegar, salad oil, and meat sauce in a 1:1:1 ratio by weight, and tightly sealed. The prepared pouch was subjected to steam retort sterilization at 120°C for 30 minutes, and then, immediately after that, the printed multilayer film was observed for any change in the condition of the print thereon.
®: There is no change
O: The print has changed slightly
Δ: The print has changed in a considerable area x: The entire print has changed [0044]
Table 3 summarizes the ink used, whether or not an EBcurable OP varnish layer was placed, the water content of the ink, the amount of the nonreactive (non-electron-beamcurable) resin, the amount of the electron beampolymerizable compound(s), the proportion of the nonreactive resin to the amount of the electron beam-polymerizable compound(s) as 100, the VOC content of the ink, and the results of testing on a printed multilayer film for Examples 1 to 5 and Comparative Example 1. The numerical values in Table 3 represent numbers of parts by mass. [0045] [Table 3]
(Table 3) Examples Comparative Example 1
1 2 3 4 5
Ink used Ink 1 Ink 2 Ink 3 Ink 3 Ink 4 Ink 5
EB-curable OP varnish (DIG WFJM1000 varnish) No No No Yes No No
Water content of the ink (wt%) 33.0 33.0 33.0 33.0 51.0 54.0
Water-based resin (X) (amount of nonreactive resin) (wt%) 9.7 3.9 9.7 9.7 21.4 23.3
Electron beam-polymerizable compound(s) (Y) Amount of the electron beam-polymerizable compound(s) (wt%) 40.0 49.3 40.0 40.0 10.0 5.0
Proportion of the nonreactive resin to the electron beam-polymerizable compound(s) as 100 (X/Y) 24.25 7.91 24.25 24.25 214.0 466.0
VOC content of the ink (wt%) 0 0 0 0 0 0
Test results Adhesion to a substrate O Δ O O © ©
Boiling suitability © © © © Δ X
Retort suitability © © © © Δ X
Abrasion resistance O O O © Δ X
[0046]
The electron beam-curable surface-printing water-based flexo ink according to the present invention can be used without considering its VOC content (%) and does not need aging time after printing. An outer container surface of a boilable/retort pouch printed with this ink is superior in abrasion resistance and boiling/retort suitability.

Claims (9)

  1. CLAIMS [Claim 1]
    An electron beam-curable surface-printing water-based flexo ink comprising a water-based resin (X), at least one electron beam-polymerizable compound having an ethylenic double bond (Y), at least one pigment, and water, wherein a ratio by mass between a solids content of the waterbased resin (X) and a solids content of the electron beampolymerizable compound having an ethylenic double bond (Y) is in a range of (X)/(Y) = 5/100 to 400/100.
  2. [Claim 2]
    The electron beam-curable surface-printing water-based flexo ink according to Claim 1, wherein the electron beampolymerizable compound having an ethylenic double bond (Y) is a water-soluble (meth)acrylic monomer and/or a watersoluble (meth)acrylic oligomer.
  3. [Claim 3]
    The electron beam-curable surface-printing water-based flexo ink according to Claim 1 or 2, wherein the electron beam-polymerizable compound having an ethylenic double bond (Y) is polyethylene glycol di(meth)acrylate .
  4. [Claim 4]
    The electron beam-curable surface-printing water-based flexo ink according to any one of Claims 1 to 3, wherein the water-based resin (X) is a nonreactive water-based urethane resin .
  5. [Claim 5]
    The electron beam-curable surface-printing water-based flexo ink according to any one of Claims 1 to 4, wherein energy intensity of the electron beam is between 30,000 and 300,000 eV, and an irradiation dose of the electron beam is between 5 and 100 kGy-m/min. (kilogray).
  6. [Claim 6]
    A printed article comprising a plastic film and an electron beam-curable surface-printing water-based flexo ink according to any one of Claims 1 to 5 applied thereto using a flexographic printer.
  7. [Claim 7]
    A multilayer material comprising a printed article according to Claim 6 and a substrate laminated together using a lamination adhesive.
  8. [Claim 8]
    A boilable pouch comprising a printed article according to Claim 6 and a substrate laminated together using a lamination adhesive.
  9. [Claim 9]
    A retort pouch comprising a printed article according to Claim 6 and a substrate laminated together using a lamination adhesive.
AU2018344119A 2017-10-02 2018-09-25 Electron beam-curable water-based flexo ink for surface printing and boilable/retort pouch using same Active AU2018344119B9 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2017-192646 2017-10-02
JP2017192646 2017-10-02
PCT/JP2018/035303 WO2019069736A1 (en) 2017-10-02 2018-09-25 Electron beam-curable water-based flexo ink for surface printing and boilable retort pouch using same

Publications (3)

Publication Number Publication Date
AU2018344119A1 true AU2018344119A1 (en) 2020-04-09
AU2018344119B2 AU2018344119B2 (en) 2020-10-01
AU2018344119B9 AU2018344119B9 (en) 2020-10-08

Family

ID=65994579

Family Applications (1)

Application Number Title Priority Date Filing Date
AU2018344119A Active AU2018344119B9 (en) 2017-10-02 2018-09-25 Electron beam-curable water-based flexo ink for surface printing and boilable/retort pouch using same

Country Status (4)

Country Link
JP (1) JP6557799B1 (en)
CN (1) CN111108159B (en)
AU (1) AU2018344119B9 (en)
WO (1) WO2019069736A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022209932A1 (en) * 2021-03-30 2022-10-06 Ｄｉｃグラフィックス株式会社 Laminate having printing layer of water-based liquid ink
WO2023054026A1 (en) 2021-09-30 2023-04-06 東レ株式会社 Method for manufacturing printed matter

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981000569A1 (en) * 1979-08-31 1981-03-05 Staybond Pty Ltd A polymerizable water-based composition
JPH08218016A (en) * 1995-02-09 1996-08-27 Canon Inc Ink for ink-jet printing, device for producing ink-jet print using the same and production of ink-jet print
JPH11100528A (en) * 1997-09-26 1999-04-13 Dainippon Ink & Chem Inc Active energy ray curable water-borne composition
US7037953B2 (en) * 2000-03-29 2006-05-02 Sun Chemical Corporation Radiation curable aqueous compositions
US6772683B2 (en) * 2002-02-19 2004-08-10 Sun Chemical Corporation Method and apparatus for wet trapping with energy-curable flexographic liquid inks
JP2005225083A (en) * 2004-02-13 2005-08-25 Toyo Ink Mfg Co Ltd Printing structure
US20070263060A1 (en) * 2005-01-14 2007-11-15 Mikhail Laksin Hybrid Energy Curable Solvent-Based Liquid Printing Inks
WO2009115489A1 (en) * 2008-03-18 2009-09-24 Cytec Surface Specialties, S.A. Aqueous radiation curable polyurethane compositions
US20110143055A1 (en) * 2008-08-12 2011-06-16 Basf Se Dispersions of polyurethanes, their preparation and use
TW201412891A (en) * 2012-06-15 2014-04-01 Sun Chemical Corp Lithographic offset inks with water and filler content
CN103436095B (en) * 2013-09-08 2015-05-27 鲁继烈 Ultraviolet-curing water-based inkjet ink
JP6875831B2 (en) * 2016-11-09 2021-05-26 サカタインクス株式会社 Water-based flexographic printing ink composition for front printing

Also Published As

Publication number Publication date
JPWO2019069736A1 (en) 2019-11-14
CN111108159B (en) 2021-06-11
WO2019069736A1 (en) 2019-04-11
AU2018344119B9 (en) 2020-10-08
CN111108159A (en) 2020-05-05
JP6557799B1 (en) 2019-08-07
AU2018344119B2 (en) 2020-10-01

Similar Documents

Publication Publication Date Title
JP7439408B2 (en) Image forming method
EP3743473B1 (en) Low migration electron beam curable primer
EP3166797B1 (en) Radiation-curable inkjet inks and coatings
AU2018344119B9 (en) Electron beam-curable water-based flexo ink for surface printing and boilable/retort pouch using same
KR102207761B1 (en) Ec primer coating for paper and paperboard
WO2017180496A1 (en) Process for electron beam curable inkjet formulations
EP3594006A1 (en) Method for producing printed material and printing machine
WO2014165323A1 (en) Uv-curable inkjet and overprint varnish combination
JP2010047670A (en) Composition for printing liquid, and printing liquid using the same
US8399534B2 (en) EC coating and inks having improved resistance
JP6938954B2 (en) Image forming method and image forming apparatus
US20230183520A1 (en) Image forming method, active energy ray-curable composition set, and image forming apparatus
JP7317262B2 (en) Laminate and wrapping paper or container using the laminate
CN116262805A (en) Active energy ray-curable composition
JP2020093430A (en) Production method of printed matter
JP7368673B1 (en) Active energy ray-curable offset ink composition and laminate for metal printing
JP7557097B1 (en) Aqueous liquid compositions for coating plastic substrates, water-based varnishes, water-based mediums, water-based primers, water-based inks, laminates, labels and packaging materials
JP7341388B1 (en) Active energy ray-curable ink composition for metal printing and its laminate
WO2024083791A1 (en) Energy curable ink, coating and primer compositions containing highly alkoxylated glycerol acrylates for retort packaging applications
JP7258204B1 (en) Active energy ray-curable offset ink, printed matter using the same, and method for producing printed matter
JP2023085741A (en) Varnish for paper, paper coated with the varnish for paper, and package
JP2019064699A (en) Lid material and manufacturing method of the same
JP2024050432A (en) Gravure ink composition, coating material, laminate and steam releasing packaging bag, lid material, label
Oguz et al. Examination of the optimum use of uv lacquers and inks in the offset printing
JP2023096902A (en) Coated paper, and package or container including the coated paper

Legal Events

Date Code Title Description
DA3 Amendments made section 104

Free format text: THE NATURE OF THE AMENDMENT IS: AMEND THE INVENTION TITLE TO READ ELECTRON BEAM-CURABLE WATER-BASED FLEXO INK FOR SURFACE PRINTING AND BOILABLE/RETORT POUCH USING SAME

SREP Specification republished
FGA Letters patent sealed or granted (standard patent)