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
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
• • 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
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/26—Printing on other surfaces than ordinary paper
  • B41M1/30—Printing on other surfaces than ordinary paper on organic plastics, horn or similar materials
• • 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
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • 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
• • 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
  • C09D11/106—Printing inks based on artificial resins containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds

Definitions

• the present invention relates to a liquid ink composition that can be used as a laminating gravure ink or flexographic ink for flexible packaging, as well as printed materials and laminates that use this liquid ink composition.
• Gravure ink and flexographic ink are widely used to impart beauty and functionality to printed materials.
• gravure- or flexographically printed materials are used as packaging materials, particularly food packaging, they are typically laminated. In this case, various printing materials and lamination processes are used depending on the type of contents and intended use.
• Patent Documents 1 and 2 describe the addition of carboxylic acids to inks that do not use toluene or methyl ethyl ketone to improve viscosity stability and adhesion.
• polyurethane resin and vinyl chloride-vinyl acetate copolymer resin have been widely used as binder resins in printing inks.
• PVC vinyl chloride-vinyl acetate copolymer resin
• These resins are a binder combination that can achieve both excellent dispersibility and high film properties, and are essential ink ingredients for achieving various properties such as good printability, post-printing blocking resistance, adhesion to substrates required for laminating inks, lamination strength, and boiling retort properties.
• Plastic waste discarded as general waste includes a variety of plastics, including chlorinated resins such as polyvinyl chloride and polyvinylidene chloride. These chlorinated resins release hydrogen chloride during the thermal decomposition process of recycling, generating hydrochloric acid, which can corrode equipment and piping.
• the objective of the present invention is to provide a liquid ink composition that is environmentally friendly and does not use chlorine-based resins, yet has excellent highlight transferability (a printability characteristic) and post-printing blocking resistance, and has good adhesion to substrates, making it suitable for laminate printing.
• the present invention provides a liquid ink composition containing a pigment, a binder resin, an organic solvent, silica, and wax, wherein the binder resin contains a polyurethane resin (A) and a polyvinyl butyral resin (B).
• the present invention relates to a printed matter obtained by printing the liquid ink composition.
• the present invention relates to a laminate having a printed layer formed by printing the liquid ink composition.
• the present invention relates to packaging materials containing the laminate.
• the present invention makes it possible to provide a liquid ink composition that is environmentally friendly and does not use chlorine-based resins, yet has excellent highlight transferability (a printability characteristic) and post-printing blocking resistance, and has good adhesion to substrates, making it suitable for laminate printing.
• the liquid ink composition refers to a liquid printing ink, such as gravure ink or flexographic ink, that is applied to a printing method using a printing plate, and is preferably gravure ink or flexographic ink.
• the liquid ink of the present invention does not contain any active energy-curable component, i.e., is an active energy ray-unreactive liquid ink.
• the liquid ink composition of the present invention is a liquid ink composition containing a pigment, a binder resin, an organic solvent, silica, and wax, and is characterized in that the binder resin contains a polyurethane resin (A) and a polyvinyl butyral resin (B).
• the polyurethane resin (A) functions as a binder resin to improve the adhesion of ink, and also functions as a pigment dispersing resin.
• the polyurethane resin (A) is preferably one in which polyester polyol and polyether polyol are used as reaction raw materials, and the mass ratio of the polyester polyol is higher in the total mass of the polyester polyol and polyether polyol. That is, the polyol structure of the polyurethane resin (A) preferably contains structural units derived from polyester polyol, which can improve laminate strength. Furthermore, the polyether polyol structure preferably contains structural units derived from polyether polyol, which can improve ink dispersibility and fluidity and also improve adhesion.
• the mass ratio of the polyester polyol to the polyether polyol in the polyol structure is preferably in the range of 45:55 to 100:0, more preferably in the range of 55:45 to 100:0, and even more preferably in the range of 80:20 to 99:1.
• a mass ratio of the polyester polyol to the polyether polyol within the range of 45:55 to 100:0 is preferred because it allows for the production of printed matter that is less prone to blocking.
• a mass ratio of the polyester polyol to the polyether polyol within the range of 80:20 to 99:1 is preferred because it allows for the production of inks that are particularly excellent in lamination strength, adhesion, and ink dispersibility.
• a mass ratio of the polyester polyol to the polyether polyol within the range of 80:20 to 99:1 provides good compatibility, allowing for favorable storage stability and flowability.
• the polyester polyol is preferably a polyester polyol obtained by dehydration condensation or polymerization of a low-molecular-weight polyol and a polycarboxylic acid or an anhydride thereof. By introducing ester groups into the polyester polyol to increase its cohesive energy, laminate strength can be further improved.
• the low molecular weight polyol may be any of a variety of known compounds having two or more hydroxyl groups commonly used in the production of polyester polyols, and may be used alone or in combination. Specific examples include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, and 2-butyl-2-ethyl-1,3 Examples of glycols that can be used include branched glycols such
• the polycarboxylic acids or anhydrides thereof may be any of the various known polycarboxylic acids commonly used in the production of polyester polyols, and may be used alone or in combination of two or more. Specific examples include polycarboxylic acids having 6 or fewer carbon atoms and two or more carboxyl groups, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, and the anhydrides of these acids; aromatic dicarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, and the anhydrides of these acids; aliphatic dicarboxylic acids, such as pimelic acid, suberic acid, azelaic acid, sebacic acid, and dimer acid; tricarboxylic acids, such as trimellitic acid and its anhydride; benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacar
• the polyester polyol may be any of various known polyester polyols commonly used in the production of polyurethane resin (A), such as polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone, and poly( ⁇ -methyl- ⁇ -valerolactone), and may be used alone or in combination of two or more types.
• polyester polyols obtained by ring-opening polymerization of cyclic ester compounds, for example, lactones such as polycaprolactone, polyvalerolactone, and poly( ⁇ -methyl- ⁇ -valerolactone)
• lactones such as polycaprolactone, polyvalerolactone, and poly( ⁇ -methyl- ⁇ -valerolactone
• the number average molecular weight of the polyester polyol is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 7,000, and even more preferably in the range of 900 to 6,000.
• the number-average and weight-average molecular weights are values measured by gel permeation chromatography (GPC) under the following conditions.
• Measurement device High-speed GPC device ("HLC-8220GPC” manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were connected in series and used. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000” (7.8mm I.D. x 30cm) x 1 "TSKgel G3000” (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mm I.D.
• the polyether polyol can be any of the various known polyether polyols commonly used in the production of polyurethane resin (A), and one or more may be used in combination.
• Examples include polyether polyols that are polymers or copolymers of methylene oxide, ethylene oxide, propylene oxide, tetrahydrofuran, etc.
• Specific examples include known, general-purpose polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.
• the inclusion of a polyether polyol significantly improves adhesion, particularly on high-performance barrier films, resulting in excellent blocking resistance and laminate strength.
• the polyether polyol preferably has a number average molecular weight of 100 to 3,500, more preferably 100 to 2,000, and even more preferably 100 to 1,000. If the number average molecular weight of the polyether polyol is less than 100, the film of the polyurethane resin (A) tends to be hard and the adhesion to the polyester film tends to be reduced. If the number average molecular weight is more than 3,500, the film of the polyurethane resin (A) tends to be brittle and the blocking resistance of the ink film tends to be reduced.
• the polyether polyol is preferably contained in the range of 1% to 50% by mass per 100 parts by mass of polyurethane resin (A), and 1% to 40% by mass is even more preferable.
• the polyether polyol is 1% by mass or more per 100 parts by mass of polyurethane resin (A)
• the solubility of the polyurethane resin (A) in ketone, ester, and alcohol-based solvents is ensured, resulting in good adhesion to high-performance barrier films.
• the ink film is easily re-dissolved in these solvents, improving the tone reproducibility of printed matter.
• the polyether polyol is 50% by mass or less, the ink film has appropriate flexibility, which tends to result in good blocking resistance.
• polyurethane resin (A) used in the liquid ink composition of the present invention As a polyol to be used in combination with the polyurethane resin (A) used in the liquid ink composition of the present invention as needed, various known polyols commonly used in the production of polyurethane resin (A) can be used, and one or more of them may be used in combination.
• Examples include saturated or unsaturated low-molecular-weight polyols (1); polycarbonate polyols (2) obtained by reacting the above-mentioned low-molecular-weight polyols with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, or phosgene; polybutadiene glycols (3); glycols (4) obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols (4) obtained by copolymerizing, in one molecule, one or more hydroxyethyl groups, hydroxypropyl acrylate, hydroxybutyl acrylate, or the like, or their corresponding methacrylic acid derivatives, with, for example, acrylic acid, methacrylic acid, or an ester thereof.
• the aforementioned co-used polyols include polyester polyols and/or polyether polyols
• the content of the polyester polyols and/or polyether polyols contained in the co-used polyols is also included in the mass of the polyester polyols and/or polyether polyols, respectively, in the polyol structure of the polyurethane resin (A).
• the diisocyanate compound used in the polyurethane resin (A) in the liquid ink composition of the present invention includes various known aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc. that are commonly used in the production of polyurethane resin (A).
• 1,5-naphthylene diisocyanate 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclohexane-1
• diisocyanate compounds include 4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate,
• chain extenders that can be used in the polyurethane resin (A) in the liquid ink composition of the present invention include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, etc., as well as amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine.
• chain extenders can be used alone or in combination of two or more.
• a monovalent active hydrogen compound can also be used as an end-capping agent for the purpose of terminating the reaction.
• examples of such compounds include dialkylamines such as di-n-butylamine, and alcohols such as ethanol and isopropyl alcohol.
• an amino acid such as glycine or L-alanine can be used as a reaction terminator.
• the polyurethane resin (A) in the liquid ink composition of the present invention can be produced, for example, by a two-stage process in which polypropylene glycol and a co-used polyol are reacted with a diisocyanate compound in a proportion such that the isocyanate groups are in excess to obtain a prepolymer having terminal isocyanate groups, and the resulting prepolymer is then reacted with a chain extender and/or a terminal blocking agent in a suitable solvent, i.e., an ester solvent commonly used as a solvent for non-toluene gravure inks, such as ethyl acetate, propyl acetate, or butyl acetate; a ketone solvent such as acetone, methyl ethyl ketone, or methyl isobutyl ketone; an alcohol solvent such as methanol, ethanol, isopropyl alcohol, or n-butanol; a hydrocarbon solvent such as
• the two-stage process is preferred for obtaining a uniform polyurethane resin (A). Furthermore, when producing polyurethane resin (A) by a two-stage process, it is preferable to react the chain extender and/or end-capping agent so that the total equivalent ratio of amino groups in the chain extender and/or end-capping agent is 1/0.9 to 1.3. If the equivalent ratio of isocyanate groups to amino groups is less than 1/1.3, the chain extender and/or end-capping agent may remain unreacted, causing the polyurethane resin (A) to yellow or emitting an odor after printing. Furthermore, in recent years, from the viewpoint of the working environment, it is more preferable not to use aromatic solvents such as toluene and xylene, or ketone solvents.
• aromatic solvents such as toluene and xylene, or ketone solvents.
• the weight-average molecular weight of the polyurethane resin (A) obtained in this manner is preferably in the range of 15,000 to 100,000, and more preferably in the range of 15,000 to 80,000. If the weight-average molecular weight of the polyurethane resin (A) is less than 15,000, the blocking resistance of the resulting ink composition and the strength and oil resistance of the printed film tend to be low. If it exceeds 100,000, the viscosity of the resulting ink tends to be high and the gloss of the printed film tends to be low.
• the content of polyurethane resin (A) used in the liquid ink composition of the present invention in the ink is preferably 4% by mass or more relative to the total mass of the ink from the viewpoint of ensuring sufficient adhesion of the ink to the substrate, and 25% by mass or less from the viewpoint of appropriate ink viscosity and work efficiency during ink production and printing, with a range of 6 to 15% by mass being more preferred.
• the lower limit of the solids mass ratio in the ink is preferably 5% by mass, more preferably 10% by mass, more preferably 15% by mass, and even more preferably 20% by mass.
• the upper limit of the solids mass ratio in the ink is preferably 95% by mass, more preferably 90% by mass, more preferably 80% by mass, and even more preferably 75% by mass.
• the liquid ink composition of the present invention contains a polyvinyl butyral resin (B) in order to improve dispersibility and adhesion.
• the polyvinyl butyral resin (B) contains only carbon atoms, hydrogen atoms, and oxygen atoms as constituent elements, and therefore can reduce the risk of environmental pollution in the life cycle of products such as packages that use the polyvinyl butyral resin (B).
• the polyvinyl butyral resin (B) is not particularly limited and may be any known resin. In general, a reaction product obtained by acetalizing polyvinyl alcohol with butyraldehyde by a known reaction can be used.
• the weight average molecular weight of the polyvinyl butyral resin (B) is preferably 5,000 to 60,000, more preferably 6,000 to 50,000, and even more preferably 7,000 to 40,000. By setting the weight average molecular weight of the polyvinyl butyral resin (B) within the above range, an ink with an excellent balance between fluidity and dispersibility can be obtained.
• the glass transition temperature (hereinafter sometimes referred to as Tg) of polyvinyl butyral resin (B) is preferably in the range of 50°C to 120°C, more preferably in the range of 55°C to 115°C, and even more preferably in the range of 60°C to 110°C.
• the glass transition temperature is obtained by measurement using a differential scanning calorimeter.
• the hydroxyl group content of the polyvinyl butyral resin (B) is preferably in the range of 10% by mass to 30% by mass, and more preferably 15% to 25% by mass. By adjusting the hydroxyl group content of the polyvinyl butyral resin (B) to fall within the above range, an ink with an excellent balance between fluidity and dispersibility can be obtained.
• the amount of acetyl groups in the polyvinyl butyral resin (B) is preferably 10% by mass or less, and more preferably 8% by mass or less. By adjusting the amount of acetyl groups in the polyvinyl butyral resin (B) to fall within the above range, an ink having an excellent balance between fluidity and dispersibility can be obtained. Furthermore, the degree of acetalization of the polyvinyl butyral resin (B) is preferably from 60 to 90% by mass, more preferably from 65 to 85% by mass.
• the content of polyvinyl butyral resin (B) (solid content of polyvinyl butyral resin (B)) is preferably 0.1% to 5% by mass, more preferably 0.1% to 4.0% by mass, and most preferably 0.2% to 3.0% by mass, relative to 100% by mass of the liquid ink composition. Adding a total of 0.1% by mass or more of polyvinyl butyral resin (B) tends to maintain the adhesion and transferability of the ink film, while keeping the total content 5% by mass or less can maintain the lamination strength of the ink. Furthermore, the lower limit of the solids weight ratio in the ink is preferably 0.1% by mass, more preferably 0.2% by mass, and most preferably 0.3% by mass.
• the upper limit of the solids weight ratio in the ink is preferably 16% by mass, more preferably 13% by mass, and most preferably 10% by mass.
• the total mass of the polyurethane resin (A) and the polyvinyl butyral resin (B) is preferably 80 mass% or more, more preferably 85 mass% or more, even more preferably 90 mass% or more, and still more preferably 95 mass% or more, based on the total mass of the resins.
• the liquid ink composition of the present invention may contain a resin that can be used in combination with the polyurethane resin (A) in the technical field of liquid inks.
• the resin may be a binder resin or a dispersing resin, but is preferably added as a binder resin.
• resins examples include ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyamide resins, acrylic resins, polyester resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, petroleum resins, cellulose-based resins, and polyurethane resins (A) other than polyurethane resin (A).
• the liquid ink composition of the present invention does not contain a chlorine-based resin.
• These resins can be used alone or in combination.
• the content of the co-used resin is preferably 0.1% by mass to 25% by mass, more preferably 2% by mass to 15% by mass, based on the total mass of the ink.
• cellulose-based resin examples include cellulose acetate propionate, cellulose acetate butyrate and other cellulose ester resins, nitrocellulose (also known as soluble cellulose), hydroxyalkyl cellulose, carboxyalkyl cellulose, etc.
• the cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, etc., and the alkyl group may further have a substituent.
• cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose are preferred as cellulose-based resins.
• the weight-average molecular weight of the cellulose-based resin is preferably 5,000 to 200,000, more preferably 10,000 to 50,000.
• the glass transition temperature of the cellulose-based resin is preferably 120°C to 180°C.
• Nitrocellulose is preferably obtained as a nitric acid ester by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydroglucopyranose group in the natural cellulose with nitric acid groups.
• Rosin-modified maleic acid resins are alkyd resins obtained by reacting a polyhydric alcohol such as glycerin, pentaerythritol, or ethylene glycol with an adduct of rosin and maleic acid obtained by Diels-Alder reaction.
• the acid value is determined by the blending ratio of the polyhydric alcohol reacted with the adduct of rosin and maleic acid and the degree of esterification.
• a polybasic acid may also be used in combination to form a structure in which a long-chain alkyd resin is bonded to the rosin skeleton.
• polybasic acids that can be used together with these polyhydric alcohols as raw materials for alkyd resins include phthalic anhydride, terephthalic acid, isophthalic acid, adipic acid, maleic acid, itaconic acid, succinic acid, and sebacic acid.
• a compound having a carbon-carbon unsaturated double bond such as maleic acid
• a compound having a carbon-carbon unsaturated double bond such as maleic acid
• a styrene-based monomer to produce a rosin-modified styrene-maleic acid resin, which is also included in the rosin-modified maleic acid resin category.
• silica refers collectively to silicon dioxide (SiO 2 ) or a substance composed of silicon dioxide. Silica may be crystalline or amorphous. It may also be silica contained in natural minerals or may be added to dioctahedral smectite. Crystalline silica refers to a solid substance having a crystalline structure (in which the atoms, ions, or molecules that make up the crystal are arranged with three-dimensional periodicity to form a spatial lattice). Amorphous silica refers to a solid substance in which atoms (or molecules) aggregate without forming crystals with a regular spatial arrangement.
• silicon examples include silicon dioxide, epoxy-modified silicone, amino-modified silicone, and polyester-modified silicone.
• the shape of the “silica” is not particularly limited, but particulate silica (hereinafter also referred to as “silica particles") is preferred.
• the preferred particle size distribution of the silica is determined using the volume-based particle size distribution measured using a laser diffraction particle size analyzer.
• the cumulative 90% particle diameter (D90) of the volume-based particle size distribution of the silica is preferably 3 ⁇ m or more, more preferably 4 ⁇ m or more, and even more preferably 5 ⁇ m or more.
• the cumulative 90% particle diameter (D90) is preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less, and even more preferably 30 ⁇ m or less.
• the cumulative 50% particle diameter (D50) of the volume-based particle size distribution of the silica is preferably 1 ⁇ m or more, more preferably 32 ⁇ m or more, and even more preferably 3 ⁇ m or more.
• the cumulative 50% particle diameter (D50) is preferably 30 ⁇ m or less, more preferably 20 ⁇ m or less, and even more preferably 10 ⁇ m or less.
• the cumulative 10% particle diameter (D10) of the volume-based particle size distribution of the silica is preferably 1 ⁇ m or more, more preferably 1.5 ⁇ m or more, and even more preferably 2 ⁇ m or more.
• the cumulative 10% particle diameter (D10) of the volume-based particle size distribution of the silica is preferably 10 ⁇ m or less, more preferably 5 ⁇ m or less, and even more preferably 4 ⁇ m or less.
• the volume-based particle size distribution of the silica preferably has a cumulative 50% particle diameter (D50) of 1 ⁇ m or more and 10 ⁇ m or less, and the index (D90-D10)/D50, calculated using the cumulative 90% particle diameter (D90), cumulative 50% particle diameter (D50), and cumulative 10% particle diameter (D10) of the particle size distribution, is less than 2.0 (i.e., (D90-D10)/D50 ⁇ 2.0), more preferably less than 1.5, and even more preferably less than 1.0. Since the ink layer on a laminate film is generally about 1 ⁇ m thick, a liquid ink composition with silica particles equal to or larger than this thickness will have excellent blocking resistance.
• the index (D90-D10)/D50 represents the uniformity of size per particle diameter; a smaller value indicates less variation in the particle diameter of the powder in the measured system.
• the surface of the ink layer containing the liquid ink composition becomes rough, which results in an increase in the adhesive area between the ink layer and the extruded melt layer or other layer that comes into contact with the ink layer, thereby improving strength, which is preferable.
• the silica content of the liquid ink composition of the present invention is preferably 0.1% to 5.0% by mass, based on the total solids content (ink solids content). Of these, 0.5% to 4.5% by mass is more preferable, and 1.0% to 4.0% by mass is most preferable.
• the liquid ink composition of the present invention contains a wax.
• the wax to be used is not particularly limited as long as it is one that is normally used in gravure inks or flexographic inks, such as hydrocarbon waxes and amide waxes.
• hydrocarbon waxes include polyethylene wax, Fischer-Tropsch wax, paraffin wax, microcrystalline wax, polypropylene wax, etc.
• hydrocarbon waxes including polyethylene wax and/or Fischer-Tropsch wax are preferred, and these may be used alone or in combination of two or more.
• a preferred amide wax is fatty acid amide wax (sometimes called fatty acid amide wax).
• fatty acid amides sometimes called fatty acid amides; hereinafter, “amide” may also be referred to as “amide”
• amide include palmitic acid amide, stearic acid amide, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, and erucic acid amide. These may be used alone or in combination of two or more.
• the wax is preferably contained in an amount of 0.05 to 2.0% by mass, more preferably 0.1 to 1.5% by mass, and most preferably 0.2 to 1.0% by mass, based on the total amount of solids (ink solids) in the liquid ink composition of the present invention.
• a hydrocarbon wax when added, it is preferably contained in an amount of 0.05 to 2.0% by mass, more preferably 0.1 to 1.5% by mass, and most preferably 0.2 to 1.0% by mass, based on the total amount of solids (ink solids) of the liquid ink composition of the present invention.
• amide wax when added, it is preferably contained in an amount of 0.05 to 2.0% by mass, more preferably 0.1 to 1.5% by mass, and most preferably 0.2 to 1.0% by mass, based on the total amount of solids (ink solids) of the liquid ink composition of the present invention.
• fatty acid amide wax is preferred.
• the silica and wax are used in combination, and it is preferable to use them so that the silica:wax mass ratio is in the range of 50:50 to 95:5, as this will result in a liquid ink composition with better blocking resistance.
• the silica:wax mass ratio is preferably in the range of 55:45 to 95:5, and most preferably in the range of 60:40 to 90:10.
• the pigment used in the liquid ink composition of the present invention may be either a colored pigment or a white pigment.
• the pigment is not particularly limited, and examples thereof include inorganic pigments and organic pigments commonly used in inks, paints, and recording agents.
• the pigment is preferably an organic pigment.
• organic pigments examples include soluble azo pigments, insoluble azo pigments, azo pigments, phthalocyanine pigments, halogenated phthalocyanine pigments, anthraquinone pigments, anthanthrone pigments, dianthraquinonyl pigments, anthrapyrimidine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, azomethine azo pigments, flavanthrone pigments, diketopyrrolopyrrole pigments, isoindoline pigments, indanthrone pigments, and carbon black pigments.
• Examples include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, cromophtal yellow, cromophtal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. Both non-acid-treated and acid-treated pigments can be used. Specific examples of preferred organic pigments are listed below.
• black pigments examples include C.I. Pigment Black 1, C.I. Pigment Black 6, C.I. Pigment Black 7, C.I. Pigment Black 9, and C.I. Pigment Black 20.
• indigo pigments examples include C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, C.I. Pigment Blue 15:5, C.I. Pigment Blue 15:6, C.I. Pigment Blue 16, C.I. Pigment Blue 17:1, C.I. Pigment Blue 22, C.I. Pigment Blue 24:1, C.I. Pigment Blue 25, C.I. Pigment Blue 26, C.I. Pigment Blue 60, C.I. Pigment Blue 61, C.I. Pigment Blue 62, C.I.
• pigments include C.I. Pigment Blue 63, C.I. Pigment Blue 64, C.I. Pigment Blue 75, C.I. Pigment Blue 79, and C.I. Pigment Blue 80.
• green pigments examples include C.I. Pigment Green 1, C.I. Pigment Green 4, C.I. Pigment Green 7, C.I. Pigment Green 8, C.I. Pigment Green 10, and C.I. Pigment Green 36.
• red pigments examples include C.I. Pigment Red 1, C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 4, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red 7, C.I. Pigment Red 8, C.I. Pigment Red 9, C.I. Pigment Red 10, C.I. Pigment Red 11, C.I. Pigment Red 12, C.I. Pigment Red 15, C.I. Pigment Red 16, C.I. Pigment Red 17, C.I. Pigment Red 18, C.I. Pigment Red 19, C.I. Pigment Red 20, C.I. Pigment Red 21, C.I. Pigment Red 22, C.I. Pigment Red 23, C.I. Pigment Red 31, C.I.
• Pigment Red 32 C.I. Pigment Red 38, C.I. Pigment Red 41, C.I. Pigment Red 43, C.I. Pigment Red 46, C.I. Pigment Red 48, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 48:4, C.I. Pigment Red 48:5, C.I. Pigment Red 48:6, C.I. Pigment Red 49, C.I. Pigment Red 49:1, C.I. C.I. Pigment Red 49:2, C.I. Pigment Red 49:3, C.I. Pigment Red 52, C.I. Pigment Red 52:1, C.I. Pigment Red 52:2, C.I.
• Pigment Red 53 C.I. Pigment Red 53:1, C.I. Pigment Red 53:2, C.I. Pigment Red 53:3, C.I. Pigment Red 54, C.I. Pigment Red 57, C.I. Pigment Red 57:1, C.I. Pigment Red 58, C.I. Pigment Red 58:1, C.I. Pigment Red 58:2, C.I. Pigment Red 58:3, C.I. Pigment Red 58:4, C. C.I. Pigment Red 60:1, C.I. Pigment Red 63, C.I. Pigment Red 63:1, C.I. Pigment Red 63:2, C.I. Pigment Red 63:3, C.I. Pigment Red 64:1, C.I.
• pigments include C.I. Pigment Red 266, C.I. Pigment Red 268, C.I. Pigment Red 269, C.I. Pigment Red 270, C.I. Pigment Red 271, C.I. Pigment Red 272, and C.I. Pigment Red 279.
• purple pigments examples include C.I. Pigment Violet 1, C.I. Pigment Violet 2, C.I. Pigment Violet 3, C.I. Pigment Violet 3:1, C.I. Pigment Violet 3:3, C.I. Pigment Violet 5:1, C.I. Pigment Violet 13, C.I. Pigment Violet 19 ( ⁇ -type, ⁇ -type), C.I. Pigment Violet 23, C.I. Pigment Violet 25, C.I. Pigment Violet 27, C.I. Pigment Violet 29, C.I. Pigment Violet 31, C.I. Pigment Violet 32, C.I. Pigment Violet 36, C.I. Pigment Violet 37, C.I. Examples include C.I. Pigment Violet 38, C.I. Pigment Violet 42, and C.I. Pigment Violet 50.
• yellow pigments examples include C.I. Pigment Yellow 1, C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I. Pigment Yellow 13, C.I. Pigment Yellow 14, Pigment Yellow 17, C.I. Pigment Yellow 24, C.I. Pigment Yellow 42, C.I. Pigment Yellow 55, C.I. Pigment Yellow 62, C.I. Pigment Yellow 65, C.I. Pigment Yellow 74, C.I. Pigment Yellow 83, C.I. Pigment Yellow 86, C.I. Pigment Yellow 93, C.I. Pigment Yellow 94, C.I. Pigment Yellow 95, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 117, C.I.
• suitable pigments include C.I. Pigment Yellow 174, C.I. Pigment Yellow 180, C.I. Pigment Yellow 185, and C.I. Pigment Yellow 213.
• orange pigments examples include C.I. Pigment Orange 5, C.I. Pigment Orange 13, C.I. Pigment Orange 16, C.I. Pigment Orange 34, C.I. Pigment Orange 36, C.I. Pigment Orange 37, C.I. Pigment Orange 38, C.I. Pigment Orange 43, C.I. Pigment Orange 51, C.I. Pigment Orange 55, C.I. Pigment Orange 59, C.I. Pigment Orange 61, C.I. Pigment Orange 64, C.I. Pigment Orange 71, and C.I. Pigment Orange 74.
• brown pigments examples include C.I. Pigment Brown 23, C.I. Pigment Brown 25, and C.I. Pigment Brown 26.
• preferred pigments include C.I. Pigment Black 7 as a black pigment, C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, and C.I. Pigment Blue 15:6 as indigo pigments, C.I. Pigment Green 7 as a green pigment, and C.I. Pigment Red 57:1, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 146, C.I. Pigment Red 242, C.I. Pigment Red 185, and C.I.
• Examples of pigments that can be used include C.I.
• Inorganic pigments include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithopone, antimony white, and gypsum.
• titanium oxide is particularly preferred. Titanium oxide exhibits a white color and is preferable in terms of coloring power, hiding power, chemical resistance, and weather resistance. From the standpoint of printing performance, it is preferable that the titanium oxide has been treated with silica and/or alumina.
• Inorganic pigments other than white include, for example, carbon black, aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, and zircon.
• Aluminum is available in powder or paste form, but it is preferable to use it in paste form for ease of handling and safety reasons. Whether leafing or non-leafing aluminum is used can be selected appropriately based on brightness and density.
• the pigment is preferably contained in an amount sufficient to ensure the concentration and coloring power of the liquid ink composition, i.e., 1 to 60% by mass of the total mass of the ink, or 10 to 90% by mass in terms of the weight ratio of solids in the ink.
• colorants can be used alone or in combination of two or more types.
• the present invention may also contain extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc., as needed.
• a dispersant can also be used in combination to further stabilize the pigment.
• dispersants include anionic, nonionic, cationic, and amphoteric surfactants.
• examples include comb-structured polymers in which polyethyleneimine is polyester-added, or alkylamine derivatives of ⁇ -olefin maleic acid polymers.
• Specific examples include the Solsperse series (ZENECA), Ajisper series (Ajinomoto), and Homogenol series (Kao).
• ZENECA Solsperse series
• Ajisper series Ajinomoto
• Homogenol series Kao
• the BYK series BYK-Chemie
• EFKA series EFKA
• the dispersant content in the ink is preferably 0.05% by mass or more of the total ink weight, and from the perspective of lamination suitability, it is preferably 5% by mass or less. A range of 0.1 to 2% by mass is even more preferable.
• organic solvent Various organic solvents can be used as the organic solvent in the liquid ink composition of the present invention, and examples thereof include aromatic organic solvents such as toluene and xylene, ketone-based organic solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ester-based organic solvents such as ethyl acetate, n-propyl acetate, butyl acetate and propylene glycol monomethyl ether acetate, and alcohol-based organic solvents such as n-propanol, isopropanol, n-butanol and propylene glycol monomethyl ether, and these can be used alone or in mixtures of two or more. In recent years, from the viewpoint of the working environment, it has become preferable not to use aromatic organic solvents such as toluene and xylene or ketone-based organic solvents.
• aromatic organic solvents such as toluene and xylene or ket
• the mass ratio is more preferably 2:1 to 9:1, and even more preferably 2:1 to 8:1.
• the liquid ink composition of the present invention may contain water as a volatile component in addition to the organic solvent.
• the water content is preferably less than 10% by mass of the total ink composition.
• the addition of water can control the drying properties of the ink, and in particular, in gravure printing, it can beautifully reproduce the gradation areas characterized by low ink transfer. Furthermore, a water content in the range of 1% to 5% by mass of the total ink composition is particularly preferred, as this improves printability.
• the addition of water can also reduce the amount of organic solvent used. Water may be added to the organic solvent in advance to form a water-containing organic solvent, or a specific amount of water may be added separately.
• the liquid ink composition of the present invention can be a one-component type that does not use a curing agent such as an isocyanate curing agent, or a two-component type that does use a curing agent, and can provide a liquid ink composition that has excellent ink dispersibility and flowability.
• a curing agent such as an isocyanate curing agent
• a two-component type that does use a curing agent
• the liquid ink composition of the present invention can be produced by dissolving and/or dispersing a resin, a pigment, etc. in an organic solvent.
• a pigment dispersion is produced by dispersing the pigment in an organic solvent using a polyvinyl butyral resin (B), and the ink can be produced by blending other compounds, resins, etc. with the resulting pigment dispersion.
• the pigment may be dispersed using a polyurethane resin (A), another resin, or a dispersant, but it is preferable to disperse the pigment using a polyvinyl butyral resin (B).
• the particle size distribution of the pigment in the pigment dispersion can be adjusted by appropriately adjusting the size of the grinding media of the disperser, the packing ratio of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, etc.
• the disperser commonly used ones such as a roller mill, a ball mill, a pebble mill, an attritor, a sand mill, etc. can be used. If the ink contains air bubbles or unexpectedly large particles, these will degrade the quality of the printed matter, so it is preferable to remove them by filtration, etc. Any conventional filter can be used.
• the viscosity of the ink produced by the above method is preferably in the range of 10 mPa ⁇ s or more from the viewpoint of preventing sedimentation of the pigment and adequately dispersing it, and 1,000 mPa ⁇ s or less from the viewpoint of workability during ink production and printing.
• the above viscosity is measured at 25°C using a B-type viscometer manufactured by Tokimec Co., Ltd.
• the viscosity of the ink can be adjusted by appropriately selecting the types and amounts of raw materials used, such as the polyurethane resin (A), the polyvinyl butyral resin (B), the pigment, the organic solvent, etc.
• the viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.
• the hues of the liquid ink composition of the present invention vary depending on the type of pigment used. There are five basic process colors: yellow, crimson, indigo, black, and white, and three outside the process gamut colors: red (orange), grass (green), and purple. Furthermore, base colors such as transparent yellow, peony, vermilion, brown, gold, silver, pearl, and a nearly transparent medium (containing extender pigments as needed) for adjusting color density are also available. For boil retort inks, the appropriate color is selected taking into consideration the pigment's migration properties and heat resistance.
• the liquid ink composition of the present invention can be printed to form a printed matter.
• the printing method can be a printing method using a known printing plate such as gravure printing or flexographic printing, but gravure printing is particularly preferred.
• the cylinder used for gravure printing is a known type such as an engraved type or an etched type.
• the layer on which the desired pattern is formed using the liquid ink composition of the present invention is referred to as the "printed layer.”
• the printed layer may be a single layer, or there may be multiple printed layers. When there are multiple printed layers, the liquid ink composition used for each printed layer may be the same, may have the same composition but with different colorants, or may have different compositions.
• the printed matter may have, for example, a first printed layer formed from a color liquid ink composition, a second white printed layer formed from a white liquid ink, and a third white printed layer in this order.
• the first printed layer can form a pattern using a pigment
• the second white printed layer and the third printed layer formed from the white liquid ink can be used as a background for the pattern.
• the second or third printed layer is an overprint varnish, it does not need to contain a colorant such as a pigment.
• the base ink is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing or flexographic printing, and is supplied to each printing unit either alone or mixed together for printing.
• the laminate of the present invention has the following structure: Examples of the substrate include, but are not limited to, (1) substrate/adhesive layer/printing layer/substrate, (2) substrate/adhesive layer/substrate/printing layer/adhesive layer/substrate, (3) substrate/adhesive layer/first printing layer/second printing layer/substrate, (4) substrate/adhesive layer/barrier layer/printing layer/adhesive layer/substrate, and (5) substrate/printing layer/adhesive layer/substrate. Additional substrates may also be included. When multiple substrates are included, the substrates may be the same or different.
• the substrate may also be a substrate such as a sealable sealant film or a multilayer film including a sealant layer formed by a heat-sealing agent, and the sealable layer is referred to as the sealant layer.
• the adhesive layers may have the same composition or different compositions.
• an anchor coat layer may be sandwiched between the adhesive layers to improve the adhesive strength of the adhesive layers.
• a laminate structure in which layers between substrates are laminated via an adhesive layer has been exemplified.
• an extrusion lamination structure in which a molten resin is extruded without providing an adhesive layer may be used.
• polyethylene or polypropylene is preferably used as the extrusion resin.
• an imine-based, butadiene-based, or isocyanate-based anchor coat layer may be provided on the printing layer, and a resin may be melt-extruded onto the anchor coat layer.
• the liquid ink composition of the present invention is useful as a substrate for printing on a wide variety of films, from general-purpose films to various high-performance films.
• Usable plastic films are not particularly limited, and examples thereof include films made of polyamide resins such as Ny6, nylon 66, and nylon 46; polyester resins such as polyethylene phthalate (PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate; biodegradable resins typified by polyhydroxycarboxylic acids such as polylactic acid, aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate); thermoplastic resins such as polyolefin resins such as polypropylene (PP) and polyethylene, polyimide resins, polyarylate resins, and mixtures thereof; various high-performance films coated with an inorganic or organic barrier coating material on their surfaces; and laminates thereof.
• films made of polyester, polyamide, polyethylene, and polypropylene are particularly preferred. These films may be unstretched or stretched films, and the manufacturing method is not limited. They may be multilayer films produced by co-extrusion of the resins of each layer, or multilayer sealant films having a sealant layer as the outermost layer of the multilayer film.
• the thickness of the base film is also not particularly limited, but is usually in the range of 1 to 500 ⁇ m.
• the substrate may be made from biomass polyolefin.
• Biomass polyolefin refers to a polyolefin resin that uses plant-derived olefins as the raw material monomers.
• the raw material monomers may contain petroleum-derived monomers, and do not have to contain 100% plant-derived monomers.
• Commercially available biomass polyolefins can also be used. Examples of commercially available products include SGM9450F, SLL118, SLL118/21, SLL218, SLL318, SLH118, SLH218, and SLH0820 manufactured by Braskem.
• the substrate used in the laminate of the present invention may be a substrate in which a vapor-deposited layer made of an inorganic substance and/or an inorganic oxide is provided on the above-mentioned resin film.
• a substrate with such a vapor-deposited layer barrier properties can be imparted to the laminate of the present invention.
• the vapor-deposited layer can be formed by a known method using a known inorganic substance or inorganic oxide, and the composition and method of formation thereof are not particularly limited.
• the laminate may have two or more vapor-deposited films, and these may have the same composition or different compositions.
• the vapor-deposited layer may be, for example, a vapor-deposited film of an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y).
• an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y).
• inorganic oxides such as silicon oxide and aluminum oxide are transparent.
• the inorganic oxides are expressed as MOx (wherein M represents an inorganic element), such as SiOx, AlOx, etc.
• M represents an inorganic element
• the value of x can range from 0 to 2 for silicon (Si), 0 to 1.5 for aluminum (Al), 0 to 1 for magnesium (Mg), 0 to 1 for calcium (Ca), 0 to 0.5 for potassium (K), 0 to 2 for tin (Sn), 0 to 0.5 for sodium (Na), 0 to 1.5 for boron (B), 0 to 1.5 for titanium (Ti), 0 to 2 for lead (Pb), 0 to 1 for zirconium (Zr), and 0 to 1.5 for yttrium (Y).
• Silicon (Si) or aluminum (Al) is preferably used as the vapor deposition layer, and silicon (Si) having an x value in the range of 1.0 to 2.0 and aluminum (Al) having an x value in the range of 0.5 to 1.5 can be used.
• the vapor deposition layer can be formed on the surface of the substrate or the like by methods such as physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, or chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.
• PVD physical vapor deposition
• CVD chemical vapor deposition
• the preferred thickness range varies depending on the type of metal or metal oxide to be vapor-deposited, but is preferably 0.05 to 70 nm, more preferably 0.1 to 70 nm, even more preferably 3 to 70 nm, and even more preferably 5 to 60 nm.
• the above-mentioned metal-deposited films can be VM-CPP films, which are CPP films with aluminum or other metal vapor deposition, or VM-OPP films, which are OPP films with aluminum or other metal vapor deposition.
• the above-mentioned transparent vapor-deposited films can be OPP films, PET films, nylon films, etc. with silica or alumina vapor deposition. Films with a coating applied to the vapor-deposited layer can also be used for the purpose of protecting the inorganic vapor-deposited layer of silica or alumina.
• Paper can also be used as the substrate.
• Examples include high-quality paper used for printing on packaging for cosmetics, beverages, pharmaceuticals, toys, equipment, etc., kraft paper, pure white roll paper, glassine paper, parchment paper, manila cardboard, white cardboard, coated paper, art paper, construction paper, thin paper, cardboard, polyethylene-coated paper, various synthetic papers, acid-resistant paper, etc.
• the lamination method for producing the laminate of the present invention is not particularly limited, and examples thereof include dry lamination, wet lamination, non-solvent lamination, extrusion lamination, etc.
• the layer located between the substrates is called an adhesive layer.
• Adhesives used in the dry lamination process include, for example, solvent-based, two-component curing adhesives.
• a "solvent-based” adhesive is a type used in the so-called dry lamination method, in which the adhesive is applied to a substrate, heated in an oven or the like to volatilize the organic solvent in the coating, and then bonded to another substrate. It contains a polyisocyanate composition, a polyol composition, and an organic solvent capable of dissolving (diluting) them.
• biomass raw materials plant-derived raw materials
• the environmental load can be reduced by appropriately using biomass raw materials.
• biomass raw materials include castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated castor oil), and 5 to 50 mol alkylene oxide adducts of castor oil; aliphatic polybasic acids such as succinic acid, succinic anhydride, glutaric acid, adipic acid, azelaic acid, sebacic acid, and itaconic acid; alkyl esters of these acids; and dimer acids.
• castor oil-based polyols such as castor oil, dehydrated castor oil, hydrogenated castor oil (a hydrogenated castor oil), and 5 to 50 mol alkylene oxide adducts of castor oil
• aliphatic polybasic acids such as succinic acid, succinic anhydride, glutaric acid, adipic acid, azelaic acid, sebacic acid, and itaconic acid
• alkyl esters of these acids and dimer acids.
• the weight of the adhesive layer after drying is preferably 0.1 to 10 g/m 2 , more preferably 1 to 6 g/m 2 , and even more preferably 2 to 5 g/m 2.
• the thickness of the adhesive layer is preferably 0.1 to 10 ⁇ m, more preferably 1 to 7 ⁇ m, and even more preferably 2 to 5 ⁇ m.
• the adhesive layer it is preferable to use a pressure-sensitive adhesive.
• the pressure-sensitive adhesive include rubber-based adhesives obtained by dissolving polyisobutylene rubber, butyl rubber, or mixtures thereof in an organic solvent such as benzene, toluene, xylene, or hexane; or these rubber-based adhesives blended with a tackifier such as abiethylene acid rosin ester, terpene-phenol copolymer, or terpene-indene copolymer; and acrylic-based adhesives obtained by dissolving an acrylic copolymer having a glass transition point of ⁇ 20° C.
• a laminate film with particularly excellent barrier properties can be obtained.
• Particularly preferred adhesives with excellent gas barrier properties are those that satisfy at least one of the following conditions: an oxygen barrier property of 300 cc/ m2 /day/atm or less, or a water vapor barrier property of 120 g/ m2 /day or less, of a cured coating film of the adhesive applied at 3 g/ m2 (solid content).
• Commercially available products include the "PASLIM” series, such as PASLIM VM001 and PASLIM J350X manufactured by DIC Corporation, and "MAXIEVE” manufactured by Mitsubishi Gas Chemical Company, Inc.
• the adhesive layer can also be formed from a thermoplastic resin, and can be formed by a conventionally known method, such as melt extrusion lamination or sand lamination.
• the thermoplastic resin that can be used for the adhesive layer include polyethylene-based resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); polypropylene-based resins such as propylene homopolymers, propylene- ⁇ -olefin random copolymers, and propylene- ⁇ -olefin block copolymers; norbornene-based polymers and hydrogenated products thereof, such as norbornene-based copolymers (COC) obtained by copolymerizing norbornene-based monomers with olefins such as ethylene; vinyl alicyclic hydrocarbon polymers; and cyclic polyolefin-based resins such as cyclic conjugated diene polymers
• elastomers examples include polyethylene-based elastomers such as ethylene-vinyl acetate copolymer (EVA) and ethylene- ⁇ -olefin copolymers, polypropylene-based elastomers, and butene-based elastomers; ethylene-based copolymers such as ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.
• EMMA ethylene-methyl methacrylate copolymer
• EAA ethylene-e
• acid-modified polyolefin-based resins obtained by modifying the above-mentioned polyolefin-based resins with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid can also be used.
• resins obtained by graft polymerizing or copolymerizing a polyolefin resin with an unsaturated carboxylic acid, an unsaturated carboxylic anhydride, or an ester monomer can also be used. These resins may be used alone or in combination of two or more. It is also preferable to use the polyethylene resin using the above-mentioned biomass-derived ethylene as a monomer unit.
• an anchor coating layer may be provided on the surface of the layer to be laminated by applying an anchor coating agent and drying it.
• anchor coating agents include anchor coating agents made of any resin with a heat resistance temperature of 135°C or higher, such as polybutadiene-based resins, urethane resins, polyisocyanate-polyether polyols, polyethyleneimine, vinyl-modified resins, epoxy resins, polyester resins, and alkyl titanates, as well as anchor coating agents obtained by diluting the above-mentioned adhesives with organic solvents.
• polyethyleneimine-based anchor coating agents and anchor coating agents obtained by diluting the above-mentioned adhesives with organic solvents are preferred.
• a silane coupling agent may be used in combination with these as an additive, and soluble nitrocellulose may also be used in combination to enhance heat resistance.
• the packaging material of the present invention preferably comprises a laminated laminate containing the liquid ink composition of the present invention.
• the packaging material may be formed by arranging two such laminated laminates and sealing them so that their sealant layers are in contact with each other, or by folding a continuous (single) laminated laminate and sealing it so that its sealant layers are in contact with each other, or by arranging the laminated laminate and a thermoplastic resin film and sealing them so that the sealant layer of the laminated laminate is in contact with the thermoplastic resin film.
• the sealing method is not particularly limited, and may be heat sealing or ultrasonic sealing, or any known method can be used.
• the packaging material can be suitably used as a packaging body, such as packaging for food products such as Western confectionery, snacks, bread, Japanese confectionery, and seasonings, packaging for medical products such as medicines, bandages, and syringes, and packaging for hygiene products such as dustcloths, masks, and brushes.
• packaging for food products such as Western confectionery, snacks, bread, Japanese confectionery, and seasonings
• packaging for medical products such as medicines, bandages, and syringes
• packaging for hygiene products such as dustcloths, masks, and brushes.
• recycled plastic The laminate or packaging material of the present invention can also be processed directly by various known recycling plastic processing methods to produce recycled plastics.
• recycled plastics can be obtained by a production method including the steps of crushing the laminate of the present invention or the packaging material of the present invention, melting and kneading the crushed film pieces, and pelletizing the melt-kneaded mixture, after which the laminate or packaging material of the present invention is immersed in a desorption treatment solution, for example, to separate the laminate into each substrate and the recycled plastic is obtained.
• the crusher used for crushing is not particularly limited and any known crusher may be used.
• the pulverized film pieces are physically blended using methods such as melt kneading, solvent cast blending, latex blending, and polymer complexing. Melt kneading is particularly common. Examples of kneading devices include tumblers, Henschel mixers, rotary mixers, super mixers, ribbon tumblers, and V-blenders.
• the film pieces are melt-kneaded using such kneading devices and then pelletized. A single-screw or multi-screw extruder is typically used for melt kneading and pelletization.
• the film pieces may be fed as they are, or may be subjected to compression volume reduction treatment with or without heating before being fed.
• Banbury mixers, rollers, Ko-kneaders, blast mills, and Prabender Bloutographs may also be used, and these may be operated batchwise or continuously.
• the film pieces may be used as molding resins and melt-kneaded in the heating barrel of a molding machine without melt kneading.
• the weight average molecular weight (in terms of polystyrene) was measured by GPC (gel permeation chromatography) using an HLC8220 system manufactured by Tosoh Corporation under the following conditions. Separation columns: Four TSKgel GMHHR-N columns manufactured by Tosoh Corporation were used. Column temperature: 40°C. Mobile phase: tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml/min. Sample concentration: 1.0 wt%. Sample injection volume: 100 microliters. Detector: differential refractometer. The viscosity was measured at 25°C using a B-type viscometer manufactured by Tokimec Co., Ltd.
• polyurethane resin (A) solution P1 had a resin solids concentration of 30.0% by mass, an amine value of 3.00 mgKOH/g, and an Mw of the resin solids of 26,000.
• the obtained polyurethane resin (A) solution P2 had a resin solids concentration of 30.0% by mass, an amine value of 3.60 mgKOH/g, and an Mw of the resin solids of 25,000.
• the urethane prepolymer solution was added to a mixture consisting of 22.50 parts of isophorone diamine, 1.14 parts of cyclohexylamine, 305.76 parts of ethyl acetate and 210.0 parts of isopropyl alcohol, and the mixture was stirred and reacted at 45 ° C. for 5 hours to obtain a polyurethane resin (A) solution P3.
• the obtained polyurethane resin (A) solution P3 had a resin solids concentration of 30.0 mass %, an amine value of 2.00 mgKOH/g, and an Mw of the resin solids of 27,000.
• a polyvinyl butyral resin (B) (weight average molecular weight 10,000, hydroxyl group content 15 mass%, glass transition point 60°C, acetyl group content 8 mass%) obtained by reacting polyvinyl alcohol with butyraldehyde was dissolved in n-propyl acetate to form a solution with a solid content of 15%, which was used as a polyvinyl butyral resin (B) solution.
• cellulose resin solution 80 parts of a mixed solution of isopropyl alcohol/ethyl acetate (ratio: 40/40 by weight) was added to 20 parts of cellulose acetate propionate CAP482-0.5 (manufactured by Eastman Chemical Co.), and the mixture was thoroughly mixed to prepare a cellulose ester (CAP) resin solution with a resin solids concentration of 20% by mass.
• CAP cellulose ester
• Example 1 A mixture of 9 parts of polyurethane resin (A) solution P1 (30% solids), 1.5 parts of polyvinyl butyral resin (B) (15% solids), 0.6 parts of cellulose acetate propionate resin solution (20% solids), 0.5 parts by mass of silica (particle size 4 ⁇ ), 0.15 parts of fatty acid amide solution (10% solids), 10 parts of phthalocyanine blue pigment (FASTGEN Blue LA5380: manufactured by DIC Corporation), 45 parts of ethyl acetate, and 2 parts of water (total of 100 parts) was kneaded using a Dynomill (manufactured by Willy & Bachofenon) to prepare the liquid ink of Example 1. The amounts of various solvents added later were adjusted so that the amounts contained in the resin solution and the amounts added later were equal to the amounts listed above.
• Dynomill manufactured by Willy & Bachofenon
• Examples 2 to 10 and Comparative Examples 1 and 2 Using the formulations shown in Tables 1 and 2, liquid inks of Examples 2 to 10 and Comparative Examples 1 and 2 were produced in the same manner as in Example 1.
• the resulting liquid ink was evaluated using the following test methods.
• a non-oriented polypropylene film (CPP film) having an anchor coat layer (LX470, SI75) was then laminated onto the adhesive-coated surface, and the resulting laminate was aged at 40°C for 3 days to obtain a laminate having a configuration of "OPP film/printed layer/dry laminating adhesive layer/anchor coat layer (LX470, SI75)/CPP film.”
• the resulting laminate was cut into a width of 15 mm and subjected to a 90-degree peel test at a pulling rate of 300 mm/min. Dry laminate strength (OPP/CPP) is expressed in N/15 mm.
• Non-solvent (solvent-free adhesive) laminate appearance The viscosity of the inks described in the Examples and Comparative Examples was adjusted to 16 seconds (25°C) using a Zahn Cup #3 (Rigo Co., Ltd.) with ethyl acetate. They were then printed onto Toyobo Co., Ltd.'s OPP film "P2161 (thickness: 20 ⁇ m)" using a gravure proofing machine equipped with a 35 ⁇ m deep gravure plate. DIC's solvent-free adhesive 2K-SF-900A/HA-930B was applied to the printed surface using a non-solvent laminator at a coating weight of 2 g/ m2 .
• cellophane tape manufactured by Nichiban Co., Ltd., 12 mm wide
• PTT film a corona-treated polyester film
• Emblem ON thickness: 15 ⁇ m
• the state of ink transfer to the non-printed side was evaluated using the following five-point scale of 1 to 5.
• the blocking resistance was similarly evaluated for the following substrate films: a corona-treated polyester film "Ester E5102 (thickness: 12 ⁇ m)" manufactured by Toyobo Co., Ltd. (hereinafter referred to as "PET film”), a corona-treated nylon film “EMBLEM ON (thickness: 15 ⁇ m)” manufactured by Unitika Ltd. (hereinafter referred to as "NY film”), and an alumina-deposited transparent PET film "IB-PET-PUB (thickness: 12 ⁇ m)” manufactured by Dai Nippon Printing Co., Ltd.

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