Aqueous liquid compositions for coating paper substrates, aqueous varnishes, aqueous mediums, aqueous primers, aqueous inks, laminates, labels, and packaging materials.

Abstract

The present invention provides an aqueous liquid composition that exhibits excellent gloss, heat resistance, and abrasion resistance of the coating film, good adhesion to paper substrates, reduces stencil entanglement, and also has good storage stability and dispersibility when pigments are incorporated. [Solution] Acrylic resin A (excluding acrylic emulsion resin) with an acid value of 80 to 260 mgKOH / g or less, and acrylic emulsion resin B and R with an acid value (mgKOH / g) of 10 or more and less than 80, and a glass transition temperature of 0 to 60°C. 1 -O-(AO)nR 2 An aqueous liquid composition for coating paper substrates, comprising solvent C represented by , aqueous medium D (not containing solvent C), large particle size wax E with an average particle size of 1.5 μm or more, and small particle size wax F with an average particle size of less than 1.5 μm, wherein the solid content of acrylic resin A is 8.2 to 60% by mass, the solid content of acrylic emulsion resin B is 20 to 82% by mass, the mass ratio of solid content B / A is 0.25 to 10, and the mass ratio of volatile content / C is 3 to 20.

Description

[Technical Field]

[0001] The present invention relates to aqueous liquid compositions for paper substrates, aqueous varnishes, aqueous mediums, aqueous primers, aqueous inks, laminates, labels, and packaging materials. [Background technology]

[0002] Generally, printing methods are classified by the type of printing plate used, with relief printing, intaglio printing, and lithographic printing being the most representative methods. Other specialized printing methods include stencil printing, such as screen printing. For example, relief printing such as flexographic printing is a printing method that uses a plate in which the image area (the part that becomes the letters or image) is raised. Specifically, the part to be printed is raised higher than the surrounding area, and ink is applied to this part with a roller and pressed onto the surface to be printed, thereby transferring the ink to the surface.

[0003] Regarding inks used in printing, the demand for water-based inks, which reduce organic solvent emissions during printing and residual solvents in the substrate, is increasing due to the growing awareness of reducing environmental impact in recent years. Water-based inks have a property that allows them to easily soak into paper, so they have generally been used on paper-based materials such as cardboard and paper bags. Furthermore, in flexographic printing, ink can seep into recessed areas as well as raised areas, and the ink accumulated in these recesses can transfer to non-image areas, resulting in printing smudges (also known as plate entanglement). To date, water-based inks for flexographic printing that improve plate entanglement and blocking (also called water-based flexographic inks) have been proposed (Patent Document 1). In addition, water-based liquid inks with viscosity stability, abrasion resistance, etc. have been proposed (Patent Document 2). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-203051 [Patent Document 2] Japanese Patent Publication No. 2019-094423 [Overview of the project] [Problems that the invention aims to solve]

[0005] Patent documents 1 and 2 have investigated improvements in properties such as reduced plate entanglement, blocking resistance, abrasion resistance, and long-term stability of water-based flexographic inks, but these have not always been sufficient. For example, conventional water-based flexographic inks have not achieved effects such as glossiness or heat resistance on the printed surface. According to the inventors' knowledge, it is difficult to simultaneously satisfy these properties while also improving the storage stability of the ink composition and the dispersibility when pigments are incorporated.

[0006] The object of the present invention is to provide an aqueous liquid composition for coating paper substrates that has excellent gloss, heat resistance, and abrasion resistance of the coating film, good adhesion to paper substrates, can reduce plate entanglement when used in flexographic printing, and also has good storage stability of the liquid and good dispersibility when pigments are added. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] An aqueous liquid composition used for coating paper substrates, Acrylic resin (A) having an acid value of 80 mg KOH / g or more and 260 mg KOH / g or less (however, acrylic emulsion resin is not included), An acrylic emulsion resin (B) having an acid value of 10 mg KOH / g or more and less than 80 mg KOH / g, and a glass transition temperature of 0 to 60°C, A solvent (C) represented by the following formula (c1), Aqueous medium (D) (excluding the solvent (C) mentioned above) and Large particle size wax (E) with an average particle size of 1.5 μm or more, It contains small particle size wax (F) with an average particle size of less than 1.5 μm, With respect to the total mass of solids in the aqueous liquid composition, the solids content of the acrylic resin (A) is 8.2 to 60% by mass, and the solids content of the acrylic emulsion resin (B) is 20 to 82% by mass. The mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the acrylic resin (A), B / A, is 0.25 / 1 to 10 / 1. An aqueous liquid composition for coating paper substrates, wherein the volatile content / C ratio, which represents the mass ratio of total volatile content to the solvent (C), is 3 / 1 to 20 / 1. R 1 -O-(AO)nR 2 (c1) (R in the formula) 1 , R 2 Each is independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R 1 and R 2 The elements may be identical or different from each other, A is a linear or branched alkylene group having 2 to 4 carbon atoms, and n is an integer from 1 to 6. If n is 2 or greater, the n elements A may be identical or different from each other. [2] The aqueous liquid composition according to [1], wherein the weight-average molecular weight of the acrylic resin (A) is 2,000 to 20,000. [3] The aqueous liquid composition according to [1] or [2], wherein the flash point of the solvent (C) is 0 to 140°C. [4] An aqueous liquid composition according to any one of [1] to [3], wherein the flash point is greater than 60°C. [5] The aqueous liquid composition according to any one of [1] to [4], wherein the total mass of the solid content of the aqueous liquid composition is 10 to 40% by mass with respect to the total mass of the aqueous liquid composition. [6] The aqueous liquid composition according to any one of [1] to [5], wherein the boiling point of the solvent (C) is 170 to 250°C, and the content of the solvent (C) is 1 to 22% by mass relative to the total mass of the aqueous liquid composition. [7] The aqueous liquid composition according to any one of [1] to [6], wherein the solvent (C) contains at least one selected from the group consisting of alkylene glycol, dialkylene glycol, trialkylene glycol, monoalkylene glycol monoalkyl ether, and polyalkylene glycol monoalkyl ether. [8] The average particle diameter of the large particle size wax (E) is 1.5 μm or more and 5 μm or less, and the penetration is 7 to 12. The aqueous liquid composition according to any one of [1] to [7], wherein the average particle diameter of the small particle size wax (F) is 0.4 μm or more and less than 1.5 μm, and the penetration is 0.3 to 7. [9] The aqueous liquid composition according to any one of [1] to [8], wherein the total content of the solid content of the large particle size wax (E) and the solid content of the small particle size wax (F) is 1 to 20% by mass based on the total mass of the solid content in the aqueous liquid composition.

[10] The aqueous liquid composition according to any one of [1] to [9], wherein the mass ratio C / (E + F) representing the content of the solvent (C) to the total content of the solid content of the large particle size wax (E) and the small particle size wax (F) is 0.5 / 1 to 15 / 1.

[11] The aqueous liquid composition according to any one of [1] to

[10] , which is used together with a curing agent.

[12] The aqueous liquid composition according to any one of [1] to

[11] , which is used for one or more selected from aqueous varnishes, aqueous media, and aqueous primers.

[13] An aqueous ink containing the aqueous liquid composition according to any one of [1] to

[11] and a pigment.

[14] A laminate having a printed layer formed by printing the aqueous ink according to

[13] on a paper substrate.

[15] A laminate having a printed layer formed by printing the aqueous ink according to

[13] on a white printed layer formed by printing a white ink for white underprint on a paper substrate.

[16] A laminate having a primer layer formed by coating a paper substrate with an aqueous primer consisting of an aqueous liquid composition according to any one of [1] to

[11] , a white printing layer formed by printing a white ink for white underprinting on the primer layer, and a printing layer formed by printing the aqueous ink according to

[13] on the white printing layer.

[17] A laminate according to any one of

[14] to

[16] , having a varnish layer formed by coating an aqueous varnish made from an aqueous liquid composition according to any one of [1] to

[11] as the uppermost layer.

[18] The laminate according to any one of

[14] to

[17] , wherein the 60-degree specular gloss of the printed layer is 70% or more.

[19] A laminate comprising a paper substrate, a primer layer provided in contact with the paper substrate and free of pigment, and one or both of a varnish layer provided as the uppermost layer and free of pigment, and a printing layer containing pigment, wherein one or more of the primer layer, the varnish layer, and the printing layer containing pigment are layers formed by coating with a coating solution containing the aqueous liquid composition described in any one of [1] to

[11] .

[20] The laminate according to

[19] , wherein the layer formed by coating with a coating solution containing the aqueous liquid composition has a 60-degree specular gloss of 70% or more.

[21] A label or packaging material obtained using the laminate described in any one of the above

[14] to

[20] . [Effects of the Invention]

[0008] The present invention provides an aqueous liquid composition for coating paper substrates that exhibits excellent gloss, heat resistance, and abrasion resistance of the coating film, as well as good adhesion to paper substrates, reduces plate entanglement when used in flexographic printing, and also has good storage stability and dispersibility when pigments are added. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view showing an example of the laminate of the present invention. [Figure 2]This is a schematic cross-sectional view showing another example of the laminate of the present invention. [Modes for carrying out the invention]

[0010] The present invention will now be described in detail. The following embodiments are merely illustrative for illustrating the present invention and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various forms without departing from its spirit. The following definitions of terms apply throughout this specification and the claims.

[0011] In the context of aqueous liquid compositions, "aqueous" means that the composition contains an aqueous medium. "Aqueous medium" refers to a liquid medium that contains water. "Liquid medium" refers to volatile liquids such as water and organic solvents. "Volatile components" refer to the volatile components, such as water and organic solvents, contained in an aqueous liquid composition. Specifically, the heat residue obtained by the measurement method compliant with JIS K 5601-1-2:2008 is defined as the solid component (also called the non-volatile component), and everything else is defined as the volatile component. "Acrylic resin" refers to a polymer that contains monomer units derived from (meth)acrylate. "(Meth)acrylate" is a general term for "acrylate" and "methacrylate". "(Meth)acrylic acid" is a general term for "acrylic acid" and "methacrylic acid." "(Meth)acrylamide" is a general term for "acrylamide" and "methacrylamide". The "~" symbol, which indicates a numerical range, means that the numbers before and after it are included as the lower and upper limits, respectively. The lower and upper limits of the numerical ranges disclosed herein can be combined in any way to create new numerical ranges.

[0012] The weight-average molecular weight of the resin is the weight-average molecular weight converted to the standard polystyrene molecular weight and is measured by gel permeation chromatography (GPC). The glass transition temperature of a resin is measured in accordance with JIS K 7121:2012 as follows: Using a differential scanning calorimeter, 10 mg of the resin to be measured is heated from -100°C to 160°C at a rate of 20°C / min. The glass transition temperature is determined from the intersection point of the baseline and the tangent to the endothermic curve in the resulting curve (DSC curve). The acid value of a resin is expressed in milligrams as the amount of potassium hydroxide required to neutralize acidic groups such as carboxyl groups per gram of solid content in the sample, and is measured in accordance with JIS K 5601-2-1:1999.

[0013] The average particle size of the wax is the particle size at which the cumulative frequency of the number of particles reaches 50% (median diameter: D50), calculated from the particle size distribution obtained by measuring the particle size distribution based on the number of particles using the Coulter counter method. The Coulter counter method is a method of electrically measuring the particle size and particle size distribution of wax particles dispersed in a solution by passing them through pores and observing the change in electrical signal as the particles pass through. The penetration depth of the wax is measured according to the method specified in JIS K-2235-6.3-93. Specifically, the sample is kept at a constant temperature, a 100g load is applied to a designated needle, and the needle is inserted into the sample for 5 seconds. The depth to which the needle penetrates is then measured. The sample temperature is set at 25°C.

[0014] <Aqueous liquid composition for coating paper substrates> An aqueous liquid composition for coating paper substrates according to one embodiment of the present invention (hereinafter also simply referred to as "aqueous liquid composition") contains an acrylic resin (A), an acrylic emulsion resin (B), a solvent (C), a large particle size wax (E), a small particle size wax (F), and water. A water-based liquid composition can be mixed with pigments to create a water-based ink. A water-based liquid composition that does not contain pigments can be used as a hue-adjusting liquid for water-based inks, such as a water-based medium, water-based varnish, or water-based primer. The present invention may optionally contain additional components, provided that the effects of the present invention are not impaired. The aqueous liquid composition of this embodiment is used for coating paper substrates. The type of paper substrate can be appropriately selected depending on the application and is not particularly limited. Details of the paper substrate will be described later.

[0015] <Acrylic resin (A)> Acrylic resin (A) is an acrylic resin (excluding acrylic emulsion resin) with an acid value of 80 mg KOH / g or more and 260 mg KOH / g or less. Acrylic resin (A) contributes to the dispersibility of pigments, the storage stability of the coating solution, the reduction of stencil entanglement, and the gloss of the coating layer. Examples of the acrylic resin (A) include a homopolymer of (meth)acrylate, a copolymer of two or more (meth)acrylates, and a copolymer of (meth)acrylate and a monomer other than (meth)acrylate. The ratio of (meth)acrylate units to the total mass of all monomer units constituting the acrylic resin is preferably 10 to 100% by mass, and more preferably 20 to 100% by mass.

[0016] Examples of (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; and hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. These (meth)acrylates may be used individually or in combination of two or more.

[0017] Examples of monomers other than (meth)acrylates include conjugated diene compounds such as 1,3-butadiene, isoprene, and chloroprene; aromatic vinyl compounds such as styrene, α-methylstyrene, halogenated styrene, and divinylbenzene; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide; unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid; and unsaturated carboxylic acid esters such as diethyl maleate, dibutyl maleate, dibutyl fumarate, diethyl itaconate, and dibutyl itaconate. These monomers may be used individually or in combination of two or more.

[0018] The acid value of acrylic resin (A) is between 80 mg KOH / g and 260 mg KOH / g, preferably between 100 and 255 mg KOH / g, and more preferably between 120 and 250 mg KOH / g from the viewpoint of dispersibility and storage stability. If the acid value of acrylic resin (A) is above the lower limit, it is easier to improve the dispersibility of the pigment and the storage stability of the coating solution. In addition, it is easier to improve the reduction of stencil entanglement and the heat resistance of the coating layer. If it is below the upper limit, it is easier to improve adhesion to the paper substrate and the abrasion resistance of the coating layer. If the acid value of acrylic resin (A) is within the above range, it is easier to improve the dispersibility, storage stability, reduction of stencil entanglement, adhesion, heat resistance, and abrasion resistance of the coating layer. If the acid value of acrylic resin (A) is less than 80 mgKOH / g, its dispersibility, storage stability, and heat resistance are poor, and if it is greater than 260 mgKOH / g, its abrasion resistance is poor.

[0019] The glass transition temperature of the acrylic resin (A) is preferably 0 to 140°C, more preferably 10 to 130°C, even more preferably 20 to 120°C, and particularly preferably 50 to 110°C. If the glass transition temperature of the acrylic resin (A) is above the lower limit, it is easier to improve the blocking resistance of the coating layer, and if it is below the upper limit, it is easier to improve adhesion to the paper substrate.

[0020] The weight-average molecular weight of the acrylic resin (A) is preferably 2,000 to 20,000, and more preferably 5,000 to 20,000. If the weight-average molecular weight of the acrylic resin (A) is above the lower limit, it is easier to improve the solvent resistance and blocking resistance of the coating layer, and if it is below the upper limit, it is easier to improve adhesion to the paper substrate.

[0021] Acrylic resin (A) is obtained by polymerizing a monomer component that includes (meth)acrylate and, optionally, monomers other than (meth)acrylate. The polymerization method is not particularly limited, but examples include polymerizing the monomer component by solution polymerization, bulk polymerization, emulsion polymerization, etc., in the presence of a known radical polymerization initiator. Acrylic resin (A) may be self-crosslinking type.

[0022] A commercially available acrylic resin (A) may be used. Examples of commercially available products include those manufactured by Seikoh PMC Co., Ltd., such as "Hyros-X PL-1231", "Hyros-X BL-2300", "Hyros-X NL-1253", "Hyros-X M-30", "Hyros-X YL-1098", "Hyros-X QL-1358", "Hyros-X GL-2439", "Hyros-X VL-1147", and "Hyros-X NL-1189"; and those manufactured by BASF Japan Ltd., such as "Joncryl 52J", "Joncryl PDX-6157", "Joncryl 60J", "Joncryl 70J", "Joncryl JDX-6180", "Joncryl HPD-196", "Joncryl HPD-96J", "Joncryl PDX-6137A", "Joncryl 6610", "Joncryl JDX-6500", and "Joncryl PDX-6102B". Acrylic resin (A) may be used alone or in combination of two or more types.

[0023] <Acrylic emulsion resin (B)> Acrylic emulsion resin (B) is an acrylic emulsion resin having an acid value of 10 mg KOH / g or more and less than 80 mg KOH / g, and a glass transition temperature of 0 to 60°C. Acrylic emulsion resin (B) contributes to adhesion to paper substrates, heat resistance, and abrasion resistance of the coating layer. It is preferable to use a water-dispersible acrylic emulsion resin as the acrylic emulsion resin (B). As a water-dispersible acrylic emulsion resin, for example, a core-shell type resin having acrylic resin in the shell portion can be suitably used.

[0024] The acid value of the acrylic emulsion resin (B) is 10 mg KOH / g or more and less than 80 mg KOH / g, preferably 15 to 80 mg KOH / g, and more preferably 25 to 75 mg KOH / g from the viewpoint of adhesion and heat resistance. If the acid value of the acrylic emulsion resin (B) is above the lower limit above, it is easier to improve the dispersibility of the pigment, the storage stability of the coating solution, and the heat resistance, and if it is below the upper limit above, it is easier to improve adhesion to the paper substrate. In addition, by keeping the acid value of the acrylic emulsion resin (B) within the above range, it is easier to improve dispersibility, storage stability, the heat resistance of the coating film, and adhesion. If the acid value of the acrylic emulsion resin (B) is less than 10 mg KOH / g, storage stability and heat resistance are poor, and if it is 80 mg KOH / g or more, adhesion is poor.

[0025] The glass transition temperature of the acrylic emulsion resin (B) is 0 to 60°C, with 10 to 50°C being preferred from the viewpoint of gloss, adhesion, heat resistance, and abrasion resistance. If the glass transition temperature of the acrylic emulsion resin (B) is above the lower limit, it is easier to improve the heat resistance and abrasion resistance of the coating layer, and if it is below the upper limit, it is easier to improve adhesion to the paper substrate and reduce entanglement. If the glass transition temperature of the acrylic emulsion resin (B) is below 0°C, the heat resistance and abrasion resistance are poor, and if it is above 60°C, the adhesion is poor.

[0026] Acrylic emulsion resin (B) can be produced by known methods, such as the polymer emulsifier method or the two-stage emulsion polymerization method. For example, it can be produced using a method that synthesizes a core-shell type water-dispersible acrylic resin using the polymer emulsifier method. Acrylic emulsion resin (B) can also be a commercially available product. Examples of commercially available acrylic emulsion resins (B) include the following products manufactured by Seikoh PMC Co., Ltd.: "Hyros-X QE-1042", "Hyros-X M-141", "Hyros-X TE-1048", "Hyros-X KE-1062", "Hyros-X X-436", "Hyros-X KE-1060", "Hyros-X HE-1335", "Hyros-X RE-1075", "Hyros-X PE-1304", "Hyros-X KE-2536", "Hyros-X J-140A", "Hyros-X TE-1102", "Hyros-X RE-218", "Hyros-X NE-2009", "Hyros-X JE-1056", "Hyros-X KE-1148", "Hyros-X ME-2039", "Hyros-X UE-1051", and "Hyros-X Product names manufactured by BASF Japan Ltd.: "PE-1126", "Joncryl PDX-7616A", "Joncryl PDX-7356", "Joncryl PDX-7777", "Joncryl PDX-7357", "Joncryl PDX-7182", "Joncryl PDX-7326", "Joncryl PDX-7732", "Joncryl PDX-7741", "Joncryl PDX-7787", "Joncryl PDX-7734", "Joncryl PDX-7615", "Joncryl PDX-77 Examples include "75", "Joncryl PDX-7692", "Joncryl PDX-7630A", "Joncryl PDX-7158", "Joncryl 352D", "Joncryl PDX-7199", "Joncryl PDX-7358", "Joncryl PDX-7667", "Joncryl PDX-7700", "Joncryl PDX-7696", "Joncryl PDX-7780", "Joncryl PDX-7177", "Joncryl PDX-7430", and product names from Aica Kogyo Co., Ltd. such as "Ultrasole A-25", "Ultrasole A-35", "Ultrasole A-40", "Ultrasole A-50", "Ultrasole C-63", "Ultrasole C-70", "Ultrasole D-32", "Ultrasole D-40", "Ultrasole GP-300", and "Ultrasole UL-1097".

[0027] <Solvent (C)> Solvent (C) is a glycol-based solvent represented by the following formula (c1). Solvent (C) may be one kind or two or more kinds may be used in combination. Solvent (C) contributes to reducing plate entanglement. R 1 -O-(AO)n-R 2 (c1) In formula (c1), R 1 and R 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R 1 and R 2 may be the same as or different from each other. A is a linear or branched alkylene group having 2 to 4 carbon atoms, and n is an integer of 1 to 6. When n is 2 or more, the n A's may be the same as or different from each other. The number of carbon atoms of A is preferably 2 or 3, more preferably 3. n is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 to 3.

[0028] Examples of Solvent (C) include alkylene glycol, dialkylene glycol, trialkylene glycol, monoalkylene glycol monoalkyl ether, polyalkylene glycol monoalkyl ether, etc. Examples of alkylene glycol (n = 1, R 1 , R 2 are hydrogen atoms) include propylene glycol, butylene glycol, etc. Examples of dialkylene glycol (n = 2, R 1 , R 2 are hydrogen atoms) include dipropylene glycol, diethylene glycol, etc. Examples of trialkylene glycol (n = 3, R 1 , R 2 are hydrogen atoms) include tripropylene glycol, triethylene glycol, etc. Examples of monoalkylene glycol monoalkyl ether (n = 1, R 1 , R 2Examples of propylene glycol monoalkyl ethers (where one atom is a hydrogen atom and the other is an alkyl group) include propylene glycol monomethyl ether (also known as methylpropylene glycol), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and other similar propylene glycol monoalkyl ethers. Polyalkylene glycol monoalkyl ether (n=2 or more, R 1 , R 2 Examples of dipropylene glycol monoalkyl ethers (where one atom is a hydrogen atom and the other is an alkyl group) include dipropylene glycol monomethyl ether and dipropylene glycol monoethyl ether; tripropylene glycol monoalkyl ethers such as tripropylene glycol monomethyl ether and tripropylene glycol monoethyl ether; and diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether.

[0029] Aqueous liquid compositions preferably have a flash point above 60°C. A flash point above 60°C means they are not classified as hazardous materials under the UN Recommendations on Dangerous Goods, making them easier to handle. To easily raise the flash point of the aqueous liquid composition above 60°C, the solvent (C) preferably has a flash point of 0°C or higher, more preferably 10°C or higher, and even more preferably 20°C or higher. From the viewpoint of drying properties, the upper limit of the flash point of solvent (C) is preferably 140°C or lower, more preferably 135°C or lower, and even more preferably 130°C or lower. When two or more compounds are used as solvent (C), the values ​​above represent the flash points of each compound.

[0030] The boiling point of solvent (C) is preferably 170 to 250°C, more preferably 170 to 245°C, and even more preferably 170 to 240°C from the viewpoint of drying properties. If the boiling point of solvent (C) is above the lower limit, it is easier to reduce plate entanglement, and if it is below the upper limit, it is easier to improve drying properties.

[0031] The solvent (C) preferably has a solubility in water at 20°C (unit: g / 100g-H2O) of 5g / 100g-H2O or more, more preferably 30g / 100g-H2O or more, and even more preferably 50g / 100g-H2O or more from the viewpoint of compatibility.

[0032] In terms of compatibility in aqueous liquid compositions, it is preferable that the solvent (C) contains at least one selected from the group consisting of alkylene glycol, dialkylene glycol, monoalkylene glycol monoalkyl ether, and dialkylene glycol monoalkyl ether. In particular, it is more preferable that solvent (C) contains solvent (C'), which is one or more selected from propylene glycol, dipropylene glycol, and propylene glycol monomethyl ether. The content of solvent (C') relative to the total mass of solvent (C) may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more, and may also be 100% by mass.

[0033] <Aqueous medium (D)> The aqueous liquid composition of this embodiment includes an aqueous medium. The aqueous medium (D) contributes to reducing stencil entanglement. Examples of aqueous media include water and mixed solvents of water and an organic solvent (excluding solvent (C)). The organic solvent in the mixed solvent is not particularly limited as long as it is soluble in water, but examples include alcohol-based solvents such as methanol, ethanol, propanol, n-butanol, and i-butanol; and ketone-based solvents such as acetone. These organic solvents may be used individually or in combination of two or more. The water content relative to the total mass of the aqueous medium is preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and even more preferably 80 to 100% by mass.

[0034] <wax> As the wax to be contained in the aqueous liquid composition, a combination of large-particle wax (E) and small-particle wax (F) with different average particle sizes is used. The materials of the large-particle wax (E) and the small-particle wax (F) may be the same or different. From the viewpoint of compatibility, it is preferable that they be the same.

[0035] Examples of materials for the large-particle wax (E) and small-particle wax (F) include animal and plant-based waxes such as beeswax, lanolin wax, whale wax, candelilla wax, carnauba wax, rice wax, wood wax, and jojoba oil; mineral and petroleum-based waxes such as montane wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and petrolatum; synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene wax, oxidized polyethylene wax, and oxidized polypropylene wax; modified waxes such as montane wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives; hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives; polytetrafluoroethylene wax (PTFE); and carboxylic acid esters or partial esters of polyhydric alcohols obtained by the reaction of polyhydric alcohols (glycerin, pentaerythritol, etc.) with long-chain fatty acids. The large-particle wax (E) and small-particle wax (F) may be manufactured by known methods, may be natural products, or may be commercially available products. The large-particle wax (E) or small-particle wax (F) may also be obtained by adjusting the particle size of a commercially available wax compound.

[0036] Examples of polyethylene waxes include high-density polymerized polyethylene, low-density polymerized polyethylene, oxidized polyethylene, acid-modified polyethylene, and special monomer-modified polyethylene. Fischer-Tropsch wax is a wax produced using carbon monoxide and hydrogen as raw materials by the Fischer-Tropsch process, and has a nearly saturated, unbranched, linear molecular structure. Paraffin wax can be produced by known methods of producing paraffin wax, such as solvent fractionation, distillation fractionation, and urea dewaxing.

[0037] Commercially available polyethylene waxes include the following products from Mitsui Chemicals, Inc.: "Chemipearl W100", "Chemipearl W200", "Chemipearl W300", "Chemipearl W308", "Chemipearl W400", "Chemipearl W401", "Chemipearl W500", "Chemipearl W640", "Chemipearl W700", and "Chemipearl W800"; and the following products from BYK: "CERAFLOUR925", "CERAFLOUR925N", "CERAFLOUR927N", and "CERAFLOUR929". Examples include "CERAFLOUR929N", "CERAFLOUR950", "CERAFLOUR960", "CERAFLOUR961", "CERAFLOUR988", "CERAFLOUR991", "CERAFLOUR1000", "AQUACER531", "AQUACER537", "AQUACER552", "AQUACER840", "AQUACER1547", "AQUAMAT208", and the BASF Japan product name "Joncryl Wax 4".

[0038] <Large particle size wax (E)> The large-particle wax (E) has an average particle size of 1.5 μm or more, preferably 5 μm or less, and a penetration degree of 7 to 12. The large-particle wax (E) contributes to the abrasion resistance and gloss of the coating layer. The average particle size of the large-particle wax (E) is more preferably 1.5 to 4.5 μm. If the average particle size of the large-particle wax (E) is above the lower limit of the above range, it is easier to improve abrasion resistance. If it is below the upper limit of the above range, it is easier to improve gloss. If the average particle size of the large-particle wax (E) is less than 1.5 μm, the abrasion resistance is poor. The penetration degree of the large-particle wax (E) is more preferably 8 to 12, and even more preferably 8 to 11. If the penetration degree of the large-particle wax (E) is above the lower limit of the above range, it is easier to improve abrasion resistance. If it is below the upper limit of the above range, it is easier to improve blocking resistance.

[0039] <Small particle size wax (F)> The small particle size wax (F) preferably has an average particle size of 0.4 μm or more, and less than 1.5 μm, and a penetration degree of 0.3 to 7. The small particle size wax (F) contributes to the abrasion resistance and gloss of the coating layer. The average particle size of the small-particle wax (F) is more preferably 0.6 to 1.5 μm. If the average particle size of the small-particle wax (F) is above the lower limit of the above range, glossiness is easily enhanced. If it is below the upper limit of the above range, abrasion resistance is easily enhanced. If the average particle size of the small-particle wax (F) is 1.5 μm or larger, glossiness is inferior. The penetration degree of the small particle size wax (F) is more preferably 1 to 7, and even more preferably 1 to 6. If the penetration degree of the small particle size wax (F) is above the lower limit of the above range, it is easier to improve abrasion resistance. If it is below the upper limit of the above range, it is easier to improve blocking resistance.

[0040] <Optional ingredients> The aqueous liquid composition may contain optional components other than those listed above, as needed. As optional components, known additives for coating solutions for paper substrates can be used. Examples of additives include thickeners, anti-settling agents, UV absorbers, antioxidants, leveling agents, viscoelastic modifiers, surface tension modifiers, rheology modifiers, light stabilizers, defoamers, lubricants, dispersants, stabilizers, pH adjusters, fillers, antifungal agents, antistatic agents, metal nanoparticles, magnetic powders, and the like. The optional components may be used individually or in combination of two or more.

[0041] <Composition of aqueous liquid composition> [Total solids] The total solids content (total mass of solids) of the aqueous liquid composition is preferably 10 to 40% by mass, and more preferably 15 to 35% by mass, relative to the total mass of the aqueous liquid composition. If the total solids content of the aqueous liquid composition is above the lower limit of the above range, stability is likely to be improved. If it is below the upper limit of the above range, adhesion to the paper substrate is likely to be improved.

[0042] [Acrylic resin (A)] The solid content of acrylic resin (A) relative to the total solid content of the aqueous liquid composition is 8.2 to 60% by mass, preferably 8.5 to 59% by mass, and more preferably 9 to 58% by mass from the viewpoint of dispersibility, storage stability, adhesion, heat resistance, and abrasion resistance. If the solid content of acrylic resin (A) is above the lower limit of the above range, the dispersibility of the pigment and the storage stability of the coating solution are easily improved. If it is below the upper limit of the above range, the adhesion to the paper substrate, the heat resistance and abrasion resistance of the coating layer are easily improved. If the solid content of acrylic resin (A) relative to the total solid content of the aqueous liquid composition is less than 8.2% by mass, the dispersibility and storage stability are poor, and if it is more than 60% by mass, the adhesion to the paper substrate, the heat resistance and abrasion resistance of the coating layer are poor.

[0043] [Acrylic emulsion resin (B)] The solid content of the acrylic emulsion resin (B) relative to the total solid content of the aqueous liquid composition is 20 to 82% by mass, preferably 24 to 81% by mass, and more preferably 28 to 80% by mass from the viewpoint of dispersibility, adhesion, heat resistance, and abrasion resistance. If the solid content of the acrylic emulsion resin (B) is above the lower limit of the above range, adhesion to the paper substrate, heat resistance and abrasion resistance of the coating layer are improved. If it is below the upper limit of the above range, the dispersibility of the pigment is easily improved. If the solid content of the acrylic emulsion resin (B) relative to the total solid content of the aqueous liquid composition is less than 20% by mass, adhesion, heat resistance and abrasion resistance are poor, and if it is more than 82% by mass, dispersibility is poor.

[0044] [B / A] The B / A ratio, which represents the mass ratio of the solid content of acrylic emulsion resin (B) to the solid content of acrylic resin (A) contained in the aqueous liquid composition, is 0.25 / 1 to 10 / 1, preferably 0.3 / 1 to 9.5 / 1, and more preferably 0.35 / 1 to 9 / 1 from the viewpoint of dispersibility, adhesion, heat resistance, and abrasion resistance. If B / A is above the lower limit of the above range, adhesion, heat resistance, and abrasion resistance are easily improved. If B / A is below the upper limit of the above range, dispersibility is easily improved. If B / A, which represents the mass ratio of the solid content of acrylic emulsion resin (B) to the solid content of acrylic resin (A), is less than 0.25 / 1, adhesion, heat resistance, and abrasion resistance are poor, and if it is greater than 10 / 1, dispersibility is poor.

[0045] [Solvent (C)] The solvent (C) content is preferably 1 to 22% by mass relative to the total mass of the aqueous liquid composition, and more preferably 4 to 21% by mass from the viewpoint of reducing plate entanglement. If the solvent (C) content is above the lower limit of the above range, it is easier to improve adhesion to the paper substrate and moisture friction resistance of the coating layer. If it is below the upper limit of the above range, it is easier to improve plate entanglement.

[0046] [Total volatile content / solvent (C)] The total volatile content of an aqueous liquid composition is everything except the total solid content. The total volatile content is the sum of the solvent (C), the aqueous medium, and other volatile components. The volatile matter / C ratio, which represents the mass ratio of total volatile matter to solvent (C), is between 3 / 1 and 20 / 1, with 3 / 1 to 19.5 / 1 being more preferable from the viewpoint of reducing plate entanglement, abrasion resistance, and adhesion. If the volatile matter / C is above the lower limit of the above range, it is easier to improve plate entanglement reduction. If it is below the upper limit of the above range, it is easier to improve adhesion to the paper substrate and abrasion resistance of the coating layer. If the volatile matter / C ratio, which represents the mass ratio of total volatile matter to solvent (C), is less than 3 / 1, plate entanglement reduction is poor, and if it is 20 / 1, abrasion resistance and adhesion are poor.

[0047] [Large particle size wax (E) + Small particle size wax (F)] The combined content of large-particle wax (E) and small-particle wax (F) relative to the total solid content of the aqueous liquid composition is preferably 1 to 20% by mass, and more preferably 2 to 18% by mass from the viewpoint of dispersibility and storage stability. If the total amount of wax solids in the total solid content of the aqueous liquid composition is above the lower limit of the above range, dispersibility and storage stability are easily improved. If it is below the upper limit of the above range, adhesion, heat resistance, and abrasion resistance are easily improved.

[0048] [C / (E+F)] The mass ratio of the solvent (C) content to the total solid content of large-particle wax (E) and small-particle wax (F), C / (E+F), is preferably 0.5 / 1 to 15 / 1, and more preferably 0.5 / 1 to 14 / 1. When C / (E+F) is within the above range, it is easier to improve the dispersibility of the pigment, the storage stability of the coating solution, the heat resistance, and the abrasion resistance.

[0049] [Application] The aqueous liquid composition of this embodiment can be used as an aqueous medium. The aqueous medium is used as a hue-adjusting liquid, mixed with an aqueous ink. The aqueous liquid composition of this embodiment can be suitably used as an aqueous varnish for forming a varnish layer, or as an aqueous primer for forming a primer layer.

[0050] <Method for producing aqueous liquid composition> The aqueous liquid composition of this embodiment can be obtained by mixing, for example, an acrylic resin (A), an acrylic emulsion resin (B), a solvent (C), an aqueous medium (D), a large particle size wax (E), a small particle size wax (F), and an optional component, such that each component is present in a desired amount. The method of mixing each component is not particularly limited, and the components can be mixed by various methods.

[0051] <Pigment-based and water-based inks> The aqueous ink of this embodiment comprises the aqueous liquid composition and pigment of this embodiment. Examples of pigments include conventionally known organic and inorganic pigments used in general inks, paints, and recording materials. Examples of organic pigments include phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, etc.), azo pigments (monoazo, condensed azo, etc.), slene pigments (anthraquinone, perinone, perylene, thioindigo, etc.), quinacridone pigments, dioxazine pigments, isoindolinone pigments, pyrrolopyrrole pigments, aniline black, and organic fluorescent pigments. Examples of inorganic pigments include natural products (clay, etc.), ferrocyanides (Prussian blue, etc.), sulfides (zinc sulfide, etc.), sulfates, oxides (titanium dioxide, chromium oxide, zinc oxide, iron oxide, etc.), hydroxides (aluminum hydroxide, etc.), silicates (ultramarine, etc.), carbonates, carbon (carbon black, graphite, etc.), metal powders (aluminum powder, bronze powder, zinc powder, etc.), and calcined pigments.

[0052] The pigment content is preferably 1 to 60% by mass relative to the total mass of the water-based ink. When using organic pigments as pigments, the content of the organic pigment is preferably 1 to 35% by mass relative to the total mass of the aqueous ink. When using inorganic pigments such as titanium dioxide or barium sulfate as pigments, the inorganic pigment content is preferably 10 to 60% by mass relative to the total mass of the water-based ink.

[0053] The solvent (C) content is preferably 1 to 20% by mass relative to the total mass of the water-based ink, and more preferably 5 to 19% by mass from the viewpoint of reducing ink entanglement. If the solvent (C) content is above the lower limit of the above range, it is easier to improve adhesion to the paper substrate and moisture abrasion resistance of the coating layer. If it is below the upper limit of the above range, it is easier to improve ink entanglement.

[0054] The aqueous ink of this embodiment may be used as is as a coating liquid for coating paper substrates, or it may be diluted with water or an alcohol solvent before use, or a mixture of aqueous ink and aqueous medium may be used as a coating liquid.

[0055] <Water-based ink / water-based medium> When mixing water-based ink and water-based medium, the preferred combination of water-based medium and water-based ink is the water-based medium and water-based ink combination of this embodiment. The composition of the water-based ink other than the pigment and the composition of the water-based medium may be the same or different. It is more preferable that they be the same. It is preferable that the composition of the coating solution obtained by mixing the aqueous medium of this embodiment with the aqueous ink of this embodiment is the preferred composition of the aqueous ink of this embodiment.

[0056] <Hardening agent> The aqueous liquid composition of this embodiment may be used together with a curing agent. For example, a coating liquid may be prepared by mixing the aqueous liquid composition with a curing agent, and the resulting coating liquid may be applied to a paper substrate. Alternatively, a coating liquid may be prepared by mixing the aqueous liquid composition of this embodiment and an aqueous ink containing a pigment with a curing agent. Using a hardening agent further improves the coating's properties, such as water resistance and abrasion resistance, as well as its adhesion to the paper substrate.

[0057] As a curing agent, those known in the field of coating liquids can be used, such as isocyanate-based curing agents, blocked isocyanate-based curing agents, carbodiimide-based curing agents, oxazoline-based curing agents, epoxy-based curing agents, and aziridine-based curing agents. The hardening agent may be used alone or in combination of two or more types.

[0058] <Laminate> Figures 1 and 2 are schematic cross-sectional views illustrating embodiments of the laminate of the present invention. Note that the dimensional ratios in Figures 1 and 2 differ from those of the actual dimensions for the sake of explanation. The laminate 10 in Figure 1 comprises a paper substrate 11 and a coating layer 12 provided on the back surface of the paper substrate 11. The laminate 20 in Figure 2 comprises a paper substrate 21, a second coating layer 23 provided on the surface of the paper substrate 21, and a first coating layer 22 provided on the surface of the second coating layer 23.

[0059] In the laminate 20, the first coating layer 22 is a color printed layer printed using a coating solution containing pigments to impart design, functionality, etc. The second coating layer 23 is a white coating layer (white printing layer) formed using white ink for the purpose of protecting the color printing layer and providing opacity.

[0060] The coating layer 12 in the laminate 10 and the first coating layer 22 in the laminate 20 are coating layers (hereinafter also referred to as "the main coating layer") formed using a coating liquid containing the aqueous liquid composition of this embodiment described above. The coating layer 12 and the first coating layer 22 may be single-layer structures or multi-layer structures formed by applying multiple layers of the coating liquid. The thickness (total thickness) of the coating layer 12 and the first coating layer 22 is preferably 0.2 to 15 μm, more preferably 0.3 to 10 μm, and even more preferably 0.3 to 8 μm.

[0061] In the laminate 20, the composition of the second coating layer 23, which is laminated in contact with the main coating layer (first coating layer 22), is not particularly limited. From the viewpoint of gloss, it is preferable that the coating layer is formed using an aqueous ink containing an acrylic resin as the binder resin. The thickness of the second coating layer 23 is preferably, for example, 0.2 to 3.0 μm, more preferably 0.3 to 2.0 μm, and even more preferably 0.3 to 1.5 μm.

[0062] <Paper base material> The types of paper substrates 11 and 21 can be appropriately selected depending on the application of the laminates 10 and 20. The paper substrates 11 and 21 are manufactured using, for example, natural fibers for papermaking such as wood pulp in a known paper machine, but the papermaking conditions are not particularly specified. Examples of natural fibers for papermaking include wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as Manila hemp pulp, sisal hemp pulp, and flax pulp, and pulps that have been chemically modified. As for the type of pulp, chemical pulps produced by sulfate pulping, acidic, neutral, and alkaline sulfite pulping, soda salt pulping, etc., as well as gland pulp, chemigland pulp, thermomechanical pulp, etc., can be used. Examples of papers used for printing on packaging materials for cosmetics, beverages, pharmaceuticals, toys, equipment, etc. include fine paper, kraft paper, pure white roll paper, glassine paper, parchment paper, Manila cardboard, white cardboard, coated paper, art paper, imitation paper, thin paper, cardboard, polyethylene coated paper, acid-resistant paper, and various synthetic papers.

[0063] The paper substrates 11 and 21 may be subjected to surface treatments such as corona discharge treatment, plasma treatment, flame treatment, or solvent treatment, as needed.

[0064] When the laminates 10 and 20 are used as labels, the thickness of the paper substrates 11 and 21 is preferably 5 to 100 μm, more preferably 12 to 60 μm, and even more preferably 12 to 50 μm. When the laminates 10 and 20 are used as packaging materials, the thickness of the paper substrates 11 and 21 is preferably 5 to 100 μm, more preferably 12 to 80 μm, and even more preferably 20 to 70 μm.

[0065] [60-degree specular gloss] The coated layers (e.g., color printing layer, white printing layer, varnish layer, medium layer, primer layer) formed using a coating solution (e.g., aqueous ink, aqueous varnish, aqueous medium, aqueous primer) containing the aqueous liquid composition of this embodiment exhibit excellent surface gloss. Specifically, using the coated layer as the measurement target, a gloss of 70% or higher can be obtained as measured by the method described in the examples below. A gloss of 75% or higher is preferable. Achieving a gloss above the above lower limit results in a superior appearance.

[0066] <Method for manufacturing laminates> The method for manufacturing the laminate includes the step of applying a coating solution containing the aqueous liquid composition of this embodiment onto a paper substrate to form a coating layer. The manufacturing method for the laminate 10 shown in Figure 1 includes the step of forming a coating layer 12 on one surface of the paper substrate 11 using a coating liquid. The manufacturing method for the laminate 20 shown in Figure 2 includes the steps of (2) forming a second coating layer 23 on one surface of a paper substrate 21 using a second coating liquid, and (1) forming a first coating layer 22 on the second coating layer 23 using a first coating liquid.

[0067] Each coating layer is obtained by applying the coating layer and allowing it to dry. The same coating solution may be applied again (overcoat). The coating method for the coating solution is not particularly limited, and known coating methods such as gravure printing, flexographic printing, brush coating, gravure coater method, die coater method, bar coater method, spray coating method, flow coating method, dip coating method, spin coating method, and curtain coating method can be used. Among these, flexographic printing is preferred due to its high quality and productivity.

[0068] The drying method is not particularly limited as long as it can remove the aqueous medium contained in the coated coating solution, but examples include vacuum drying, pressure drying, heat drying, and air drying. The heating temperature is preferably 30 to 150°C, and more preferably 40 to 120°C.

[0069] <Laminate> The laminate is not limited to the embodiments described above. For example, in the laminate 10 shown in Figure 1, the coating layer 12 is provided on the entire surface of one side of the paper substrate 11, but the coating layer 12 may be provided on only a part of the surface of one side of the paper substrate 11. In this case, it is preferable that another coating layer be provided in the area of ​​one side of the paper substrate 11 where the coating layer 12 is not provided. Another coating layer may be provided on the surface of the first coating layer 12 opposite to the paper substrate 11 side. For example, a varnish layer formed from a varnish composition may be provided.

[0070] In the laminate 20 shown in Figure 2, the first coating layer 22 is provided over the entire second coating layer 23, but the first coating layer 22 may be provided on only a part of the second coating layer 23. Another coating layer may be provided on the surface of the first coating layer 22 opposite to the second coating layer 23 side (the viewing side). For example, a varnish layer formed from a varnish composition may be provided.

[0071] <White ink for white underprinting> In order to further improve the sharpness of images and other elements in a color printed layer on a paper substrate, a white undercoat (also called a white coating layer or white printed layer) is created by applying white ink to the side of the color layer opposite to the viewing side. The white ink used for this purpose is called white undercoat white ink. For white underprinting, it is preferable to use an acrylic resin-containing ink from the viewpoint of substrate adhesion and abrasion resistance. While there are no particular limitations on the white pigment, titanium dioxide is preferred. In the surface printing illustrated in Figure 2, for example, a white ink for white underprinting is printed on the substrate to form a white printing layer, and then the water-based ink of the present invention is printed on top of that to form a printing layer (color printing layer). As a white ink for white underprinting, an aqueous ink containing the aqueous liquid composition of the present invention and a white pigment can be used.

[0072] <Primer layer> In the laminates illustrated in Figures 1 and 2, a primer layer may be provided on the substrate. The aqueous primer (aqueous liquid composition) of the present invention can be used as the primer composition for forming the primer layer. In the surface printing illustrated in Figure 2, for example, a primer layer is formed by coating a paper substrate with the aqueous primer of the present invention, a white underprint layer is formed by printing a white ink for white underprinting onto the substrate, and a printed layer (color printed layer) is formed by printing the aqueous ink of the present invention on top of that.

[0073] Other layers besides the primer layer may be provided on the substrate. Examples include a resin layer, a magnetic layer, a heat-sensitive layer, a photosensitive layer, and so on.

[0074] <Varnish layer> In the laminates illustrated in Figures 1 and 2, a varnish layer may be provided as the uppermost layer. The aqueous varnish (aqueous liquid composition) of the present invention can be used as the varnish composition for forming the varnish layer. In the laminate illustrated in Figure 1, for example, a color printing layer is formed on a paper substrate, and then a varnish layer, which forms the top layer, is formed on top of that. In the surface printing example shown in Figure 2, for example, a white printing layer is formed on a paper substrate, a color printing layer is formed on top of that, and then a top layer of varnish is formed on top of that. Furthermore, in the laminate illustrated in Figure 1, for example, a varnish layer may be formed on the surface opposite to the coated layer to which the coating liquid containing the aqueous liquid composition of the present invention is applied on the paper substrate. In the top-side printing example shown in Figure 2, for example, a varnish layer may be formed on the surface opposite to the white printed layer on the paper substrate.

[0075] <label> A label according to one embodiment of the present invention is obtained using the laminate of this embodiment described above. The labels can be used for various purposes, including packaging for beverages, condiments, prepared foods, bento boxes, and other food and beverage products, as well as daily necessities such as cosmetics. They are particularly suitable as labels for items whose packaging is a plastic bottle, for example, as labels for bottled food and beverages. Furthermore, the labels of this embodiment can be suitably used even if the packaging is paper-based. Examples of bottled food and beverages include beverages, liquid condiments (dressings, noodle soup bases, soy sauce, liquid miso, etc.), and edible oils. The label can take the form of, for example, a label wrapped around the bottle.

[0076] <Packaging material> Applications of packaging materials include packaging for various items such as food, daily necessities, general merchandise, and hygiene products. The shape of the packaging material is not particularly limited. Examples include bottom-seal bags, side-seal bags, three-sided-seal bags, pillow bags, gusset bags, square-bottom bags, and stand-up pouches.

[0077] According to this embodiment, as shown in the examples described later, an aqueous liquid composition for coating paper substrates is obtained that has excellent gloss, heat resistance, and abrasion resistance of the coating film, good adhesion to paper substrates, can be obtained, reduces plate entanglement when used in flexographic printing, and also has good storage stability and dispersibility when pigments are added. [Examples]

[0078] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention. In the following, "NV" refers to non-volatile content (solids). Unless otherwise specified, "%" in the unit of content means "mass%". Unless otherwise specified, "parts" means "parts by mass".

[0079] [Raw materials used] <Acrylic resin (A)> The following compounds were used as acrylic resin (A) and comparative component (A'). A-1: Manufactured by BASF Japan Ltd., product name "Joncryl 52J", weight-average molecular weight 1,700, acid value 238 mgKOH / g, glass transition temperature 56℃, solids content 60% by mass. A-2: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-NL-1189", weight-average molecular weight 11,000, acid value 90 mgKOH / g, glass transition temperature 28℃, solid content 29% by mass. A-3: Manufactured by BASF Japan Ltd., product name "Joncryl PDX-6157", weight-average molecular weight 6,000, acid value 205 mgKOH / g, glass transition temperature 84℃, solids content 34% by mass. · A'-4: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-AW-36H", weight-average molecular weight 15,000, acid value 60 mgKOH / g, glass transition temperature 53℃, solid content 25% by mass. · A'-5: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-UL-1191", weight-average molecular weight 6,500, acid value 270 mgKOH / g, glass transition temperature 128℃, solid content 32% by mass.

[0080] <Acrylic emulsion resin (B)> The following compounds were used as the acrylic emulsion resin (B) and comparative component (B'). • B-1: Manufactured by BASF Japan Ltd., product name "Joncryl PDX-7777", acid value 71 mg KOH / g, glass transition temperature 40°C, solid content 46% by mass. • B-2: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros XM-141", acid value 19 mg KOH / g, glass transition temperature 15℃, solid content 46% by mass. B-3: Manufactured by BASF Japan Ltd., product name "Joncryl PDX-7356", acid value 78 mg KOH / g, glass transition temperature 25°C, solid content 46% by mass. • B-4: Manufactured by BASF Japan Ltd., product name "Joncryl PDX-7616A", acid value 30 mg KOH / g, glass transition temperature 9°C, solid content 44% by mass. • B-5: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-QE-1042", acid value 33 mg KOH / g, glass transition temperature 53°C, solid content 41% by mass. · B'-6: Manufactured by BASF Japan Ltd., product name "Joncryl PDX-7164", acid value 4 mg KOH / g, glass transition temperature 9°C, solid content 47% by mass. ·B'-7: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-HE-2342", acid value 125 mg KOH / g, glass transition temperature 16℃, solid content 44% by mass. · B'-8: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-JE-1113", acid value 42 mg KOH / g, glass transition temperature -24℃, solid content 43% by mass. ·B'-9: Manufactured by Seikoh PMC Co., Ltd., product name "Hyros X-NE-2186", acid value 59 mg KOH / g, glass transition temperature 107℃, solid content 52% by mass.

[0081] <Comparative resin> • Urethane dispersion: Manufactured by Mitsui Chemicals, Inc., product name "Takelac W-6061", solid content 30% by mass.

[0082] <Solvent (C)> C-1: Propylene glycol, boiling point 188.2°C, flash point 99°C, solids content 0% by mass. C-2: Dipropylene glycol, boiling point 231.8°C, flash point 138°C, solids content 0% by mass. C-3: Methylpropylene glycol, boiling point 121°C, flash point 32°C, solids content 0% by mass.

[0083] <Large particle size wax (E)> • E-1: Manufactured by Mitsui Chemicals, Inc., product name "Chemipearl W-500", average particle size 2.5 μm, penetration degree 10, solid content 40% by mass. <Small particle size wax (F)> F-1: Manufactured by Mitsui Chemicals, Inc., product name "Chemipearl W-700", average particle size 1 μm, penetration degree less than 1, solid content 40% by mass. <Pigments> • Pigment: Pigment Blue 15:3 (manufactured by BASF Japan Ltd., product name "Heliogen Blue D7088", solids content 100% by mass). • Titanium dioxide: Pigment White 6 (manufactured by Ishihara Sangyo Co., Ltd., product name "CR-90", solid content 100% by mass) <Optional ingredients> • Defoaming agent: Manufactured by BIC Chemie Japan Co., Ltd., product name "BYK-094", solid content 96% by mass. • Hardener: Carbodiimide-based hardener (manufactured by Nisshinbo Chemical Co., Ltd., product name "Carbodilite E-02", non-volatile content 40% by mass)

[0084] [Evaluation Method] <Dispersibility> The dispersibility of water-based inks containing pigments was evaluated using the following method. According to the composition shown in the table, acrylic resin (A), acrylic emulsion resin (B), solvent (C), aqueous medium (D), large particle size wax (E), small particle size wax (F), pigment, and other optional components were mixed and dispersed using a bead mill (manufactured by Shinmaru Enterprises, Ltd., product name "Dinomill", using glass beads) to obtain an aqueous ink. The obtained aqueous ink was spread (applied thinly and spread) on a paper substrate, and the formed coating film (spread product) was visually inspected and evaluated according to the following evaluation criteria. ○: Can be dispersed using a bead mill, and the resulting water-based ink exhibits good color development when applied to a spreadable product. △: Dispersion processing is possible using a bead mill, but the resulting water-based ink has insufficient color development (in the case of blue pigment, the coating film is whitish; in the case of titanium dioxide, the gloss of the coating film is low). ×: This condition occurs when the dispersion liquid does not pass through the bead mill and clogs the dyno mill.

[0085] <Storage stability> The storage stability of water-based inks (or aqueous liquid compositions if no pigment is added) was evaluated using the following method. The water-based inks obtained by dispersion treatment were placed in 250 ml plastic containers and stored at 40°C for one month. After storage, the condition of the water-based inks was visually inspected and evaluated according to the following evaluation criteria. ○: No change in condition from before storage for one month. △: Slightly thicker compared to before storage for one month, but no visible change. ×: Compared to before storage for one month, the viscosity has increased significantly, or aggregates have formed.

[0086] The gloss, ink adhesion reduction, adhesion, heat resistance, and abrasion resistance of printed layers formed by printing water-based ink (or a water-based liquid composition if no pigment is included) onto a paper substrate were evaluated using the following methods. <Glossiness> A gloss meter (BYK Gardner, product name "micro-TRI-gloss") was used to measure the 60° gloss (60° specular gloss) of the printed layer surface, and the glossiness of the printed layer was evaluated according to the following criteria. A higher 60° gloss indicates superior gloss. ○: 60° Gross is 70% or more. △: 60° Gross is 60% or more, but less than 70%. ×: 60° Gross is less than 60%.

[0087] <Reduced printing entanglement> The aqueous inks (or aqueous liquid compositions if no pigment was added) obtained in each example were printed using the following method. Using a CI-type flexographic printing press (manufactured by KBA-Flexotecnica), commercially available coated paper (manufactured by Oji Paper Co., Ltd., product name "OK Topcoat Plus", basis weight 104.7 g / m²) was used. 2 The printout was created by printing at a speed of 80 m / min for 10 minutes. The anilox roll was 1000 LPI, 4 cc / m 2The following was used. The drying conditions for the printed layer were 90°C for the intercolor dryer and 90°C for the tunnel dryer. The 5% halftone area of ​​the obtained printed material was visually observed, and the degree of plate entanglement reduction was evaluated according to the following evaluation criteria. ○: No thickening of the halftone dots is observed in the 5% area, or slight thickening is observed, but the dots are not connected to each other. △: 5% The halftone dots appear slightly thickened and are somewhat connected to each other. ×: 5% The shape of the halftone dots is distorted, and the dots are clearly connected to each other.

[0088] <Adhesion> For each example, cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed layer of the laminate obtained, and then the cellophane tape was promptly peeled off. The condition of the printed layer remaining on the paper substrate (coated paper) was visually inspected, and the adhesion of the printed layer to the paper substrate was evaluated according to the following evaluation criteria. ○: The ratio of the area of ​​the peeled-off printed layer to the total area of ​​the printed layer is greater than 0% and 3% or less. △: The ratio of the area of ​​the peeled-off printed layer to the total area of ​​the printed layer is more than 3% but less than 30%. ×: The area of ​​the peeled-off printed layer is 30% or more of the total area of ​​the printed layer.

[0089] <Heat resistance> The glossy side of aluminum foil was placed over the printed surface of the laminate obtained in each example, and a load was applied for 2 seconds at 200°C and 0.2 MPa using a heat seal tester (manufactured by Tester Industry Co., Ltd.). The foil was peeled off by hand, and the presence or absence of peel resistance and the fusion state of the printed layer were visually checked and evaluated according to the following evaluation criteria. ○: There is no peeling resistance, and the printed layer does not fuse. △: Weak peel resistance, no fusion of the printed layer. ×: Has peel resistance, and the printed layer is fused.

[0090] <Abrasion resistance> For each example, a cloth (metal cloth No. 3) was placed on the printed surface of the laminate, and a load of 500 gf was applied to the friction fastness tester (manufactured by Tester Sangyo Co., Ltd.) and rubbed back and forth 100 times. After that, it was evaluated according to the following evaluation criteria in accordance with JIS L 0805. ○: The color chart changes from size 5 to 4-5. △: The color chart changes from No. 4 to No. 3. ×: Color chart number 2-3 to number 1.

[0091] <Examples 1-44> Examples 1-26 are examples, and Examples 27-44 are comparative examples. Examples 1-25 and 27-44 are examples of preparing aqueous inks containing aqueous liquid compositions and pigments. Example 26 is an example of preparing an aqueous liquid composition without pigment as an aqueous medium.

[0092] A water-based ink was obtained by mixing acrylic resin (A), acrylic emulsion resin (B), solvent (C), water (D), coarse-particle wax (E), fine-particle wax (F), defoamer, and pigment according to the formulation shown in the table. When no pigment was added, an aqueous medium was obtained by mixing acrylic resin (A), acrylic emulsion resin (B), solvent (C), water (D), coarse particle wax (E), fine particle wax (F), and an antifoaming agent according to the formulation shown in the table. The resulting aqueous ink or aqueous medium was used as a coating solution, and a laminate was manufactured using the following method.

[0093] (Example of laminate manufacturing) As a paper base material, coated paper (manufactured by Oji Paper Co., Ltd., product name "OK Topcoat Plus", basis weight 104.7 g / m²) 2 ) was used. Cell volume 10.0cm 3 / m 2 Using a flexo hand proofer equipped with an anilox roll as an applicator, each example of the coating liquid was applied to one side of a paper substrate, with a coating amount of 2.0 g / m² after drying. 2 The surface was coated (printed) in this manner. Then, it was dried with hot air from a hairdryer for one minute to form the printed layer (coating). When the coating solution was an aqueous ink, a blue or white printed layer was obtained. When the coating solution was an aqueous medium, a nearly transparent or very thin white printed layer was obtained.

[0094] (evaluation) The dispersibility of the water-based ink was evaluated using the method described above. The storage stability of the water-based ink or water-based medium was evaluated using the method described above. For the printed layer of the laminate, each item shown in the table was evaluated using the method described above. These results are shown in the table. A blank space in the table indicates that the ingredient is not included (amount: 0 parts by mass). NV in the table indicates the non-volatile content (solids) of each ingredient (unit: mass%). Furthermore, it was confirmed that the flash points of the aqueous liquid compositions in Examples 1 to 44 were above 60°C.

[0095] [Table 1]

[0096] [Table 2]

[0097] [Table 3]

[0098] [Table 4]

[0099] [Table 5]

[0100] [Table 6]

[0101] [Table 7]

[0102] [Table 8]

[0103] [Table 9]

[0104] [Table 10]

[0105] [Table 11]

[0106] [Table 12]

[0107] [Table 13]

[0108] [Table 14]

[0109] As shown in the table, Examples 1 to 26 yielded aqueous liquid compositions and aqueous inks that exhibited excellent gloss, heat resistance, and abrasion resistance of the coating film, as well as good adhesion to paper substrates, reduced plate entanglement when used in flexographic printing, and also good storage stability and dispersibility when pigments were added.

[0110] In Example 26, which is an example of an aqueous liquid composition without pigment, when B / A was set to less than 0.25, it showed a similar trend to Comparative Example 35. Also, in Example 26, when volatile matter / C was set to more than 20, it showed a similar trend to Comparative Example 38.

[0111] (Application Example 1) In the example of manufacturing the laminate described above, a white printing layer was provided between the substrate and the printing layer, and a varnish layer (top layer) was further provided on the visible side of the printing layer to form the laminate. The white printed layer was formed using the aqueous ink of Example 24, and the varnish layer was formed using the aqueous liquid composition of Example 26. The evaluation of the laminate in Application Example 1 was also confirmed to be excellent, similar to Examples 1-26.

[0112] (Application Example 2) In the above example of laminate manufacturing, LLDPE (product name "Kernel KC570S", manufactured by Nippon Polyethylene Co., Ltd.) was melt-extruded onto the opposite side of the printed layer of the coated paper base material to produce a laminate with an LLDPE film. The evaluation of the laminate obtained in Application Example 2 was also confirmed to be excellent, similar to that in Examples 1 to 26. [Explanation of Symbols]

[0113] 10, 20 laminated 11, 21 Paper base material 12 Coating layers 22 First coating layer 23. Second coating layer

Claims

1. A water-based liquid composition used for coating paper substrates, Acrylic resin (A) having an acid value of 80 mg KOH / g or more and 260 mg KOH / g or less (however, acrylic emulsion resin is not included), An acrylic emulsion resin (B) having an acid value of 10 mg KOH / g or more and less than 80 mg KOH / g, and a glass transition temperature of 0 to 60°C, In the following formula (c1), when n is 1, R １ and R ２ is an alkylene glycol in which both are hydrogen atoms; in the following formula (c1), when n is 2, R １ and R ２ is a dialkylene glycol in which both are hydrogen atoms; in the following formula (c1), when n is 3, R １ and R ２ is a trialkylene glycol in which both are hydrogen atoms; in the following formula (c1), when n is 1, R １ or R ２ is a monoalkylene glycol monoalkyl ether in which one of them is a hydrogen atom and the other is an alkyl group; and in the following formula (c1), when n is 2 or more, R １ or R ２ is at least one solvent (C) selected from the group consisting of polyalkylene glycol monoalkyl ethers in which one of them is a hydrogen atom and the other is an alkyl group Aqueous medium (D) (excluding the solvent (C)) and Large-particle wax (E) with an average particle size of 1.5 μm or more, It contains small-particle wax (F) with an average particle size of less than 1.5 μm, With respect to the total mass of solids in the aqueous liquid composition, the solids content of the acrylic resin (A) is 8.2 to 60% by mass, and the solids content of the acrylic emulsion resin (B) is 20 to 82% by mass. The mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the acrylic resin (A), B / A, is 0.25 / 1 to 10 / 1. The volatile matter / C ratio, which represents the mass ratio of total volatile matter to the solvent (C), is between 3 / 1 and 20 / 1. An aqueous liquid composition for coating paper substrates, wherein the total content of the solids of the large-particle wax (E) and the small-particle wax (F) is 1 to 20% by mass, relative to the total mass of solids in the aqueous liquid composition. R １ -O-(AO)n-R ２ (c1) (R in the formula) １ , R ２ Each is independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and R １ and R ２ The elements may be identical or different from each other, A is a linear or branched alkylene group having 2 to 4 carbon atoms, n is an integer from 1 to 6, and when n is 2 or greater, the n elements A may be identical or different from each other.

2. The aqueous liquid composition according to claim 1, wherein the weight-average molecular weight of the acrylic resin (A) is 2,000 to 20,000.

3. The aqueous liquid composition according to claim 1, wherein the flash point of the solvent (C) is 0 to 140°C.

4. The aqueous liquid composition according to claim 1, wherein the flash point is greater than 60°C.

5. The aqueous liquid composition according to claim 1, wherein the total mass of the solid content of the aqueous liquid composition is 10 to 40% by mass relative to the total mass of the aqueous liquid composition.

6. The aqueous liquid composition according to claim 1, wherein the boiling point of the solvent (C) is 170 to 250°C, and the content of the solvent (C) is 1 to 22% by mass relative to the total mass of the aqueous liquid composition.

7. The average particle size of the large-particle wax (E) is 1.5 μm or more and 5 μm or less, and the penetration degree is 7 to 12. The aqueous liquid composition according to claim 1, wherein the average particle size of the small-particle wax (F) is 0.4 μm or more and less than 1.5 μm, and the degree of penetration is 0.3 to 7.

8. The aqueous liquid composition according to claim 1, wherein the mass ratio of the solvent (C) content to the total solid content of the large-particle wax (E) and the small-particle wax (F), C / (E+F), is 0.5 / 1 to 15 / 1.

9. The aqueous liquid composition according to claim 1, for use with a curing agent.

10. The aqueous liquid composition according to claim 1, which is used for one or more selected from aqueous varnish, aqueous medium, and aqueous primer.

11. An aqueous ink comprising the aqueous liquid composition and a pigment described in claim 1.

12. A laminate having a printed layer formed by printing the aqueous ink described in claim 11 onto a paper substrate.

13. A laminate having a white printed layer formed by printing a white ink for white underprinting onto a paper substrate, and further printed with the aqueous ink described in claim 11 on top of that white printed layer.

14. A laminate comprising a primer layer formed by coating a paper substrate with an aqueous primer consisting of the aqueous liquid composition described in claim 1, a white printed layer formed by printing a white ink for white underprinting on the primer layer, and a printed layer formed by printing the aqueous ink described in claim 11 on the white printed layer.

15. The laminate according to any one of claims 12 to 14, having a varnish layer formed by coating an aqueous varnish made from the aqueous liquid composition described in claim 1 as the uppermost layer.

16. The laminate according to claim 12, wherein the 60-degree specular gloss of the printed layer is 70% or more.

17. A laminate comprising a paper substrate, a primer layer provided in contact with the paper substrate and free of pigment, and one or both of a varnish layer provided as the uppermost layer and free of pigment, and a printing layer containing pigment, wherein one or more of the primer layer, the varnish layer, and the printing layer containing pigment are layers formed by coating with a coating liquid containing the aqueous liquid composition described in claim 1.

18. The laminate according to claim 17, wherein the layer formed by coating with a coating liquid containing the aqueous liquid composition has a 60-degree specular gloss of 70% or more.

19. A label or packaging material obtained using the laminate described in any one of claims 12 to 14 and 16 to 18.

20. A label or packaging material obtained using the laminate described in claim 15.

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