Aqueous liquid compositions for coating paper substrates, water-based varnishes, water-based mediums, water-based primers, water-based inks, laminates, labels and packaging materials

Abstract

To provide an aqueous liquid composition which gives a coating excellent in gloss, heat resistance and abrasion resistance, has good adhesion to a paper substrate, can reduce plate tangling, has good liquid storage stability and good dispersibility when a pigment is blended therein. The present invention provides an acrylic resin A having an acid value of 80 to 260 mgKOH / g or less (excluding acrylic emulsion resins), an acrylic emulsion resin B having an acid value (mgKOH / g) of 10 or more and less than 80, and a glass transition temperature of 0 to 60°C, and an acrylic emulsion resin R having 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 the solid content of the acrylic resin A is 8.2-60 mass% and the solid content of the acrylic emulsion resin B is 20-82 mass%, the mass ratio of the solid content B / A is 0.25-10, and the mass ratio of the volatile content / C is 3-20, relative to the total mass of the solid content.

Description

[Technical field]

[0001] The present invention relates to an aqueous liquid composition for paper substrates, an aqueous varnish, an aqueous medium, an aqueous primer, an aqueous ink, a laminate, a label and a packaging material. [Background technology]

[0002] Generally, printing is classified by the type of plate, with letterpress printing, intaglio printing, and lithographic printing being the most common printing methods. Other special printing methods include stencil printing such as silk screen printing. For example, letterpress printing such as flexography is done using a plate with raised image areas (the areas that become the letters and pictures). Specifically, the areas to be printed are higher and more raised than the rest, and ink is applied to these areas with a roller, which is then pressed against the surface to be printed, transferring the ink to the surface to be printed.

[0003] With regard to inks used in printing, due to growing awareness of the need to reduce environmental impact in recent years, there has been an increasing demand for water-based inks that reduce organic solvent emissions during printing and residual solvents on substrates. Because water-based inks have the ability to easily soak into paper, they have generally been used on paper substrates such as cardboard and paper bags. In addition, in flexographic printing, ink can seep into recessed areas rather than raised areas, and the ink that accumulates in the recessed areas can cause printing stains (also known as plate tangles) by transferring to non-image areas. To date, water-based inks for flexographic printing (also called water-based flexographic inks) that improve plate tangling and blocking have been proposed (Patent Document 1). In addition, water-based liquid inks that have viscosity stability, abrasion resistance, and the like have been proposed (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-203051 A [Patent Document 2] JP 2019-094423 A Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1 and Patent Document 2, improvements in the properties of water-based flexographic inks, such as reduction in plate entanglement, blocking resistance, abrasion resistance, and stability over time, are considered, but are not necessarily sufficient. For example, conventional water-based flexographic inks do not achieve effects such as gloss and heat resistance on the printed surface. According to the knowledge of the present inventors, it is difficult to simultaneously satisfy these properties and improve the storage stability of the ink composition and the dispersibility when a pigment is blended therein.

[0006] An object of the present invention is to provide an aqueous liquid composition for coating paper substrates, which provides a coating film with excellent gloss, heat resistance, and abrasion resistance, has good adhesion to paper substrates, reduces plate tangling when used in flexographic printing, and also has good storage stability of the liquid and good dispersibility when a pigment is blended therein. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] An aqueous liquid composition for use in coating a paper substrate, comprising: An acrylic resin (A) having an acid value of 80 mgKOH / g or more and 260 mgKOH / g or less (however, acrylic emulsion resin is not included); An acrylic emulsion resin (B) having an acid value of 10 mgKOH / g or more and less than 80 mgKOH / g and a glass transition temperature of 0 to 60°C; A solvent (C) represented by the following formula (c1), an aqueous medium (D) (excluding the solvent (C)); A large particle size wax (E) having an average particle size of 1.5 μm or more; and a small particle size wax (F) having an average particle size of less than 1.5 μm; the content of the solid content of the acrylic resin (A) is 8.2 to 60 mass%, and the content of the solid content of the acrylic emulsion resin (B) is 20 to 82 mass%, based on the total mass of the solid content of the aqueous liquid composition; B / A, which represents a mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the acrylic resin (A), is 0.25 / 1 to 10 / 1; The aqueous liquid composition for coating a paper substrate, wherein volatile matter / C, which represents a mass ratio of the total volatile matter to the solvent (C), is 3 / 1 to 20 / 1. R 1 -O-(AO)nR 2 (c1) (R in the formula 1 , R 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 1 and R 2 may be the same or different, A is a linear or branched alkylene group having 2 to 4 carbon atoms, n is an integer of 1 to 6, and when n is 2 or more, the n As may be the same or different.) [2] The aqueous liquid composition according to [1], wherein the acrylic resin (A) has a weight average molecular weight of 2,000 to 20,000. [3] The aqueous liquid composition according to [1] or [2], wherein the solvent (C) has a flash point of 0 to 140°C. [4] The aqueous liquid composition according to any one of [1] to [3], which has a flash point of more 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 mass% relative 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 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) comprises at least one selected from the group consisting of alkylene glycols, dialkylene glycols, trialkylene glycols, monoalkylene glycol monoalkyl ethers, and polyalkylene glycol monoalkyl ethers. [8] The large particle size wax (E) has an average particle size of 1.5 μm or more and 5 μm or less and a penetration index of 7 to 12; The aqueous liquid composition according to any one of [1] to [7], wherein the small particle size wax (F) has an average particle size of 0.4 μm or more and less than 1.5 μm and a penetration index of 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 mass% relative to the total mass of solid contents in the aqueous liquid composition.

[10] The aqueous liquid composition according to any one of [1] to [9], wherein C / (E+F), which represents the mass ratio of the content of the solvent (C) to the total content of the solid contents 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] , for use 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 an aqueous varnish, an aqueous medium, and an aqueous primer.

[13] An aqueous ink comprising 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 water-based ink described in

[13] on a paper substrate.

[15] A laminate having a white printed layer formed by printing a white ink for whitening on a paper base material, and a printed layer formed by printing the water-based ink described in

[13] on top of the white printed layer.

[16] A laminate comprising a primer layer formed on a paper substrate by coating an aqueous primer made of the aqueous liquid composition described in any one of [1] to

[11] , a white printed layer formed on the primer layer by printing an undercoating white ink, and a printed layer formed on the white printed layer by printing the aqueous ink described in

[13] .

[17] The laminate described in any one of

[14] to

[16] , having as an uppermost layer a varnish layer formed by applying an aqueous varnish made of the aqueous liquid composition described in any one of [1] to

[11] .

[18] The laminate described in any one of

[14] to

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

[19] A laminate comprising a paper substrate, and one or both of a primer layer not containing a pigment and provided in contact with the paper substrate, and a varnish layer not containing a pigment and provided as an uppermost layer, and a printed layer containing a pigment, wherein one or more of the primer layer, the varnish layer, and the printed layer containing a pigment are layers formed by applying a coating liquid containing the aqueous liquid composition described in any one of [1] to

[11] .

[20] The laminate according to

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

[21] A label or packaging material obtained by using the laminate according to any one of the above

[14] to

[20] . Effect of the Invention

[0008] The present invention provides an aqueous liquid composition for coating paper substrates, which provides a coating film with excellent gloss, heat resistance, and abrasion resistance, has good adhesion to paper substrates, reduces plate tangling when used in flexographic printing, and also has good storage stability of the liquid and good dispersibility when a pigment is blended therein. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view illustrating a schematic example of a laminate of the present invention. [Diagram 2]FIG. 2 is a cross-sectional view illustrating a schematic diagram of another example of the laminate of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below. The following embodiments are merely examples for explaining 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 the spirit of the present invention. The following definitions of terms apply throughout the specification and claims.

[0011] The term "aqueous" in the aqueous liquid composition means that the composition contains an aqueous medium. "Aqueous medium" means a liquid medium that contains water. The term "liquid medium" refers to a volatilizable liquid such as water or an organic solvent. The term "volatile content" refers to volatile components such as water and organic solvents among the components contained in the aqueous liquid composition. Specifically, the heating residue obtained by a measurement method conforming to JIS K 5601-1-2:2008 is defined as the solid content (also called the non-volatile content), and the rest is defined as the volatile content. The term "acrylic resin" refers to a polymer containing 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 "~" indicating a range of numerical values ​​means that the numerical values ​​before and after it are included as the lower limit and upper limit. The lower and upper limits of the numerical ranges disclosed in this specification can be combined in any manner to create new numerical ranges.

[0012] The weight average molecular weight of the resin is a weight average molecular weight converted into a 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: A differential scanning calorimeter is used to measure 10 mg of the resin to be measured, and the temperature is calculated from the intersection of the baseline and the tangent of the endothermic curve in a curve (DSC curve) obtained by heating 10 mg of the resin to be measured from -100°C to 160°C at a rate of 20°C / min. The acid value of a resin is the amount of potassium hydroxide required to neutralize acid groups such as carboxyl groups per gram of solid content of a sample, expressed in milligrams, and is measured in accordance with JIS K 5601-2-1:1999.

[0013] The average particle size of wax is the particle size at 50% cumulative frequency (median size: D50) calculated from the particle size distribution measured by the Coulter counter method. The Coulter counter method is a method in which wax particles dispersed in a solution are passed through a fine hole, and the particle size and particle size distribution of the particles are electrically measured from the change in the electrical signal when the particles pass through the hole. The wax penetration 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 specified needle, which is inserted into the sample for 5 seconds, and the depth to which the needle penetrates is measured. The sample temperature is 25°C.

[0014] <Aqueous liquid composition for coating paper substrate> 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 pigment can be blended into the aqueous liquid composition to prepare an aqueous ink. The aqueous liquid composition does not contain a pigment and can be used as an aqueous medium, an aqueous varnish, an aqueous primer, or the like, which is a hue adjusting liquid for an aqueous ink. As long as the effects of the present invention are not impaired, any optional components may be included as necessary. The aqueous liquid composition of the present embodiment is used for coating a paper substrate. The type of the 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)> The acrylic resin (A) is an acrylic resin (excluding acrylic emulsion resins) having an acid value of 80 mgKOH / g or more and 260 mgKOH / g or less. The acrylic resin (A) contributes to the dispersibility of the pigment, the storage stability of the coating liquid, the reduction of plate 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 kinds of (meth)acrylate, 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 mass%, more preferably 20 to 100 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 alone 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; cyanide vinyl 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 alone or in combination of two or more.

[0018] The acid value of the acrylic resin (A) is 80 mgKOH / g or more and 260 mgKOH / g or less, preferably 100 to 255 mgKOH / g, and more preferably 120 to 250 mgKOH / g from the viewpoint of dispersibility and storage stability. When the acid value of the acrylic resin (A) is equal to or more than the lower limit, the dispersibility of the pigment and the storage stability of the coating liquid are easily improved. In addition, the plate entanglement reduction and the heat resistance of the coating layer are easily improved. When the acid value is equal to or less than the upper limit, the adhesion to the paper substrate and the abrasion resistance of the coating layer are easily improved. When the acid value of the acrylic resin (A) is within the above range, the dispersibility, storage stability, plate entanglement reduction, adhesion, heat resistance, and abrasion resistance of the coating layer are easily improved. If the acid value of the acrylic resin (A) is less than 80 mgKOH / g, the dispersibility, storage stability and heat resistance are poor, and if it exceeds 260 mgKOH / g, the 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. When the glass transition temperature of the acrylic resin (A) is not less than the above lower limit, the blocking resistance of the coating layer is easily improved, and when it is not more than the above upper limit, the adhesion to the paper substrate is easily improved.

[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. When the weight average molecular weight of the acrylic resin (A) is not less than the above lower limit, the solvent resistance and blocking resistance of the coating layer are easily improved, and when it is not more than the above upper limit, the adhesion to the paper substrate is easily improved.

[0021] The acrylic resin (A) is obtained by polymerizing a monomer component containing a (meth)acrylate and, if necessary, a monomer other than the (meth)acrylate. The polymerization method is not particularly limited, but examples thereof include a method in which the monomer component is polymerized by a solution polymerization method, a bulk polymerization method, an emulsion polymerization method, or the like in the presence of a known radical polymerization initiator. The acrylic resin (A) may be a self-crosslinking type.

[0022] As the acrylic resin (A), a commercially available product may be used. Examples of commercially available products include those manufactured by Seiko PMC Corporation under the product names "Hi-Loss-X PL-1231", "Hi-Loss-X BL-2300", "Hi-Loss-X NL-1253", "Hi-Loss-X M-30", "Hi-Loss-X YL-1098", "Hi-Loss-X QL-1358", "Hi-Loss-X GL-2439", "Hi-Loss-X VL-1147", and "Hi-Loss-X NL-1189"; and those manufactured by BASF Japan Ltd. under the product names "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". The acrylic resin (A) may be used alone or in combination of two or more kinds.

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

[0024] The acid value of the acrylic emulsion resin (B) is 10 mgKOH / g or more and less than 80 mgKOH / g, preferably 15 to 80 mgKOH / g, and more preferably 25 to 75 mgKOH / g from the viewpoint of adhesion and heat resistance. When the acid value of the acrylic emulsion resin (B) is equal to or more than the lower limit, the dispersibility of the pigment, the storage stability and heat resistance of the coating liquid are easily improved, and when it is equal to or less than the upper limit, the adhesion to the paper substrate is easily improved. In addition, by setting the acid value of the acrylic emulsion resin (B) within the above range, the dispersibility, storage stability, heat resistance and adhesion of the coating film are easily improved. When the acid value of the acrylic emulsion resin (B) is less than 10 mgKOH / g, the storage stability and heat resistance are poor, and when it is 80 mgKOH / g or more, the adhesion is poor.

[0025] The glass transition temperature of the acrylic emulsion resin (B) is 0 to 60°C, and from the viewpoints of gloss, adhesion, heat resistance, and abrasion resistance, it is preferably 10 to 50°C. When the glass transition temperature of the acrylic emulsion resin (B) is equal to or higher than the lower limit, the heat resistance and abrasion resistance of the coating layer are easily increased, and when it is equal to or lower than the upper limit, the adhesion to the paper substrate and the reduction in plate entanglement are easily increased. When the glass transition temperature of the acrylic emulsion resin (B) is lower than 0°C, the heat resistance and abrasion resistance are poor, and when it is higher than 60°C, the adhesion is poor.

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

[0027] <Solvent (C)> The solvent (C) is a glycol-based solvent represented by the following formula (c1). The solvent (C) may be one type or two or more types may be used in combination. The solvent (C) contributes to reducing plate entanglement. R 1 -O-(AO)nR 2 (c1) In formula (c1), R 1 , R 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R 1 and R 2 may be the same 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 or different. A preferably has 2 or 3 carbon atoms, and more preferably has 3 carbon atoms. n is preferably 1 to 5, more preferably 1 to 4, and further preferably 1 to 3.

[0028] Examples of the solvent (C) include alkylene glycol, dialkylene glycol, trialkylene glycol, monoalkylene glycol monoalkyl ether, polyalkylene glycol monoalkyl ether, and the like. Alkylene glycol (n=1, R 1 , R 2 is a hydrogen atom), examples of which include propylene glycol, butylene glycol, and the like. Dialkylene glycol (n=2, R 1 , R 2 (is a hydrogen atom) includes dipropylene glycol, diethylene glycol, and the like. Trialkylene glycol (n=3, R 1 , R 2 (is a hydrogen atom) includes tripropylene glycol, triethylene glycol, and the like. Monoalkylene glycol monoalkyl ether (n=1, R 1 , R 2wherein one is a hydrogen atom and the other is an alkyl group), examples of propylene glycol monoalkyl ethers include propylene glycol monomethyl ether (also known as methyl propylene glycol), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and the like. Polyalkylene glycol monoalkyl ether (n=2 or more, R 1 , R 2 wherein one is a hydrogen atom and the other is an alkyl group), examples thereof include dipropylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether and dipropylene glycol monoethyl ether; tripropylene glycol monoalkyl ethers such as tripropylene glycol monomethyl ether and tripropylene glycol monoethyl ether; diethylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monobutyl ether; and the like.

[0029] The aqueous liquid composition preferably has a flash point of more than 60° C. If the flash point is more than 60° C., the composition does not fall under the category of hazardous materials under the United Nations Recommendations on Dangerous Goods, and is easy to handle. From the viewpoint of making it easy to make the flash point of the aqueous liquid composition exceed 60° C., the flash point of the solvent (C) is preferably 0° C. or higher, more preferably 10° C. or higher, and even more preferably 20° C. or higher. From the viewpoint of drying property, the upper limit of the flash point of the 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 the solvent (C), the above values ​​are the flash points of each compound.

[0030] The boiling point of the solvent (C) is preferably 170 to 250° C., more preferably 170 to 245° C., and from the viewpoint of drying properties, still more preferably 170 to 240° C. When the boiling point of the solvent (C) is not less than the above lower limit, the plate entanglement reduction property is easily improved, and when it is not more than the above upper limit, the drying properties are easily improved.

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

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

[0033] <Aqueous medium (D)> The aqueous liquid composition of the present embodiment contains an aqueous medium. The aqueous medium (D) contributes to reducing plate entanglement. Examples of the aqueous medium include water and mixed solvents of water and organic solvents (excluding solvent (C)). The organic solvent in the mixed solvent is not particularly limited as long as it is soluble in water, and examples of the organic solvent 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 alone or in combination of two or more. The content of water relative to the total mass of the aqueous medium is preferably from 60 to 100 mass %, more preferably from 70 to 100 mass %, and even more preferably from 80 to 100 mass %.

[0034] <Wax> As the wax to be contained in the aqueous liquid composition, a large particle size wax (E) and a small particle size wax (F) having different average particle sizes are used in combination. The large particle size wax (E) and the small particle size wax (F) may be the same or different in material, but from the viewpoint of compatibility, it is preferable that they are the same.

[0035] Examples of the materials of the large particle size wax (E) and the small particle size wax (F) include animal and vegetable waxes such as beeswax, lanolin wax, spermaceti, candelilla wax, carnauba wax, rice wax, Japan wax, and jojoba oil; mineral and petroleum waxes such as montan 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 montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives; hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives; polytetrafluoroethylene wax (PTFE); carboxylic acid esters or partial esters of polyhydric alcohols obtained by reacting polyhydric alcohols (glycerin, pentaerythritol, etc.) with long-chain fatty acids; and the like. The large particle size wax (E) and the small particle size wax (F) may be produced by a known method, may be a natural product, or may be a commercially available product. The large particle size wax (E) or the small particle size wax (F) may be obtained by adjusting the particle size of a commercially available wax compound.

[0036] Examples of the polyethylene wax 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 by the Fischer-Tropsch process using carbon monoxide and hydrogen as raw materials, and has a nearly saturated, unbranched, linear molecular structure. Paraffin wax can be produced by known methods for producing paraffin wax, such as solvent fractionation, distillation fractionation, and urea dewaxing.

[0037] Commercially available polyethylene waxes include those manufactured by Mitsui Chemicals under the product names "CHEMIPERL W100", "CHEMIPERL W200", "CHEMIPERL W300", "CHEMIPERL W308", "CHEMIPERL W400", "CHEMIPERL W401", "CHEMIPERL W500", "CHEMIPERL W640", "CHEMIPERL W700", and "CHEMIPERL W800"; and those manufactured by BYK under the product names "CERAFLOUR925", "CERAFLOUR925N", "CERAFLOUR927N", and "CERAFLOUR929". , "CERAFLOUR929N", "CERAFLOUR950", "CERAFLOUR960", "CERAFLOUR961", "CERAFLOUR988", "CERAFLOUR991", "CERAFLOUR1000", "AQUACER531", "AQUACER537", "AQUACER552", "AQUACER840", "AQUACER1547", "AQUAMAT208"; and the product name "John Kryllwax 4" made by BASF Japan.

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

[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 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 size wax (F) is more preferably 0.6 to 1.5 μm. When the average particle size of the small particle size wax (F) is equal to or greater than the lower limit of the above range, glossiness is easily improved. When the average particle size of the small particle size wax (F) is equal to or less than the upper limit of the above range, abrasion resistance is easily improved. When the average particle size of the small particle size wax (F) is equal to or greater than 1.5 μm, glossiness is poor. The penetration of the small particle size wax (F) is more preferably 1 to 7, and even more preferably 1 to 6. When the penetration of the small particle size wax (F) is at least the lower limit of the above range, the abrasion resistance is easily improved. When it is at most the upper limit of the above range, the blocking resistance is easily improved.

[0040] <Optional ingredients> The aqueous liquid composition may contain optional components other than the above components, if necessary. As optional components, additives known in the art for paper substrate coating solutions can be used, such as thickeners, antisettling agents, UV absorbers, antioxidants, leveling agents, viscoelasticity modifiers, surface tension modifiers, rheology modifiers, light stabilizers, antifoaming agents, lubricants, dispersants, stabilizers, pH adjusters, fillers, mildew inhibitors, antistatic agents, metal particles, and magnetic powders. The optional components may be used alone or in combination of two or more.

[0041] <Composition of the aqueous liquid composition> [Total solids] The total solid content (total mass of solid content) of the aqueous liquid composition is preferably 10 to 40 mass%, more preferably 15 to 35 mass%, based on the total mass of the aqueous liquid composition. When the total solid content of the aqueous liquid composition is equal to or more than the lower limit of the above range, the stability is easily improved. When the total solid content is equal to or less than the upper limit of the above range, the adhesion to the paper substrate is easily improved.

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

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

[0044] [B / A] B / A, which represents the mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the 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 viewpoints of dispersibility, adhesion, heat resistance, and abrasion resistance. When B / A is equal to or greater than the lower limit of the above range, adhesion, heat resistance, and abrasion resistance are easily improved. When B / A is equal to or less than the upper limit of the above range, dispersibility is easily improved. When B / A, which represents the mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the acrylic resin (A), is less than 0.25 / 1, adhesion, heat resistance, and abrasion resistance are poor, and when it exceeds 10 / 1, dispersibility is poor.

[0045] Solvent The content of the solvent (C) is preferably 1 to 22% by mass, and more preferably 4 to 21% by mass, based on the total mass of the aqueous liquid composition, from the viewpoint of reducing plate tangling. When the content of the solvent (C) is equal to or more than the lower limit of the above range, it is easy to improve adhesion to the paper substrate and wet friction resistance of the coating layer. When the content is equal to or less than the upper limit of the above range, it is easy to improve reduction in plate tangling.

[0046] [Total volatiles / solvent (C)] The total volatile content is the total content of the aqueous liquid composition other than the total solid content. The total volatile content is the sum of the solvent (C), the aqueous medium, and other volatile content. The volatile content / C, which represents the mass ratio of the total volatile content to the solvent (C), is 3 / 1 to 20 / 1, and is more preferably 3 / 1 to 19.5 / 1 from the viewpoints of plate entanglement reduction, abrasion resistance, and adhesion. When the volatile content / C is equal to or greater than the lower limit of the above range, plate entanglement reduction is easily improved. When the volatile content / C is equal to or less than the upper limit of the above range, adhesion to the paper substrate and abrasion resistance of the coating layer are easily improved. When the volatile content / C, which represents the mass ratio of the total volatile content to the solvent (C), is less than 3 / 1, plate entanglement reduction is poor, and when it is 20 / 1, abrasion resistance and adhesion are poor.

[0047] [Large particle size wax (E) + Small particle size wax (F)] 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 preferably 1 to 20 mass%, and more preferably 2 to 18 mass% from the viewpoints of dispersibility and storage stability, relative to the total solid content of the aqueous liquid composition. When the total wax solid content in the total solid content of the aqueous liquid composition is equal to or more than the lower limit of the above range, dispersibility and storage stability are easily improved. When it is equal to or less than the upper limit of the above range, adhesion, heat resistance, and abrasion resistance are easily improved.

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

[0049] [Application] The aqueous liquid composition of the present embodiment can be used as an aqueous medium. The aqueous medium is used as a hue adjusting liquid by mixing with an aqueous ink. The aqueous liquid composition of the present embodiment can also be suitably used as an aqueous varnish for forming a varnish layer, or an aqueous primer for forming a primer layer.

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

[0051] <Pigments and water-based inks> The water-based ink of this embodiment contains the water-based liquid composition of this embodiment and a pigment. Examples of the pigment include conventionally known organic pigments and inorganic pigments used in general inks, paints, and recording materials. Examples of the organic pigment include phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, etc.), azo pigments (monoazo, condensed azo, etc.), threne pigments (anthraquinone, perinone, perylene, thioindigo, etc.), quinacridone pigments, dioxazine pigments, isoindolinone pigments, pyrrolopyrrole pigments, aniline black, and organic fluorescent pigments. Examples of the inorganic pigment include natural products (clay, etc.), ferrocyanides (princess blue, etc.), sulfides (zinc sulfide, etc.), sulfates, oxides (titanium oxide, 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 content of the pigment is preferably 1 to 60% by mass based on the total mass of the water-based ink. When an organic pigment is used as the pigment, the content of the organic pigment is preferably 1 to 35% by mass relative to the total mass of the water-based ink. When an inorganic pigment such as titanium oxide or barium sulfate is used as the pigment, the content of the inorganic pigment is preferably 10 to 60 mass % based on the total mass of the water-based ink.

[0053] The content of the solvent (C) is preferably 1 to 20% by mass, and more preferably 5 to 19% by mass, based on the total mass of the water-based ink, from the viewpoint of reducing plate tangling. When the content of the solvent (C) is equal to or more than the lower limit of the above range, it is easy to improve adhesion to the paper substrate and wet friction resistance of the coating layer. When the content is equal to or less than the upper limit of the above range, it is easy to improve reduction in plate tangling.

[0054] The aqueous ink of this embodiment may be used as is as a liquid (coating liquid) for coating a paper substrate, or may be diluted with water or an alcohol solvent, or a mixture of the aqueous ink and an aqueous medium may be used as a coating liquid.

[0055] <Water-based inks and media> When the aqueous ink and the aqueous medium are mixed and used, the combination of the aqueous medium and the aqueous ink to be mixed is preferably the aqueous medium of this embodiment and the aqueous ink of this embodiment. The composition of the aqueous ink other than the pigment may be the same as or different from the composition of the aqueous medium. It is more preferable that they are the same. The composition of the coating liquid obtained by mixing the aqueous medium of this embodiment and the aqueous ink of this embodiment is preferably the preferred composition of the aqueous ink of this embodiment.

[0056] <Hardening agent> The aqueous liquid composition of the present embodiment may be used together with a curing agent. For example, the aqueous liquid composition may be mixed with a curing agent to prepare a coating liquid, and the obtained coating liquid may be applied to a paper substrate. Alternatively, the aqueous liquid composition of the present embodiment and an aqueous ink containing a pigment may be mixed with a curing agent to prepare a coating liquid. Use of a curing agent improves the coating film properties such as water resistance and abrasion resistance of the coating layer, as well as adhesion to the paper substrate.

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

[0058] <Laminate> 1 and 2 are cross-sectional views each showing a schematic embodiment of a laminate of the present invention, respectively. Note that the dimensional ratios in Figs. 1 and 2 are different from the actual ones for the sake of convenience of explanation. The laminate 10 in FIG. 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 FIG. 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, for example, a color printed layer printed using a coating liquid containing a pigment in order to impart design, functionality, and the like. The second coating layer 23 is a white coating layer (white printed layer) formed using white ink for the purposes of protecting the color printed layer and imparting hiding properties.

[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 "this coating layer") formed using a coating liquid containing the aqueous liquid composition of the present embodiment described above. The coating layer 12 and the first coating layer 22 may have a single-layer structure or a multi-layer structure in which the coating liquid is applied in multiple layers. The thickness (total thickness) of the coating layer 12 and the first coating layer 22 is, for example, 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 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 second coating layer 23 is a coating layer formed using a water-based ink containing an acrylic resin as a binder resin. The thickness of the second coating layer 23 is, for example, preferably 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 type of paper base material 11, 21 can be appropriately selected depending on the application of the laminates 10, 20, etc. The material of the paper base material 11, 21 is, for example, manufactured by a known papermaking machine using natural fibers for papermaking such as wood pulp, 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 pulp obtained by chemically modifying these pulps. Examples of the types of pulp that can be used include chemical pulp, ground pulp, chemi-ground pulp, and thermomechanical pulp, which are produced by sulfate cooking, acidic, neutral, and alkaline sulfite cooking, and soda salt cooking. Examples of the types of pulp that can be used include fine paper, kraft paper, pure white roll paper, glassine paper, parchment paper, Manila board, white board, coated paper, art paper, imitation paper, thin paper, thick paper, polyethylene coated paper, acid-resistant paper, and various synthetic papers, which are used for printing on packaging materials and packages for cosmetics, beverages, medicines, toys, and equipment.

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

[0064] When the laminates 10, 20 are used as labels, the thickness of the paper base material 11, 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, 20 are used as packaging materials, the thickness of the paper base material 11, 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 present coating layer (e.g., color print layer, white print layer, varnish layer, medium layer, primer layer) formed using a coating liquid (e.g., aqueous ink, aqueous varnish, aqueous medium, aqueous primer) containing the aqueous liquid composition of this embodiment has excellent surface gloss. Specifically, using the present coating layer as the measurement subject, a 60 degree specular gloss of 70% or more can be obtained as measured by the method described in the Examples below. The gloss is preferably 75% or more. By making it equal to or greater than the above lower limit, the appearance is excellent.

[0066] <Method of manufacturing laminate> The method for producing a laminate includes a step of applying a coating liquid containing the aqueous liquid composition of this embodiment onto a paper substrate to form a coating layer. The method for producing the laminate 10 in FIG. 1 includes a step of forming a coating layer 12 on one surface of a paper substrate 11 using a coating liquid. The manufacturing method of the laminate 20 in Figure 2 includes a step (2) of forming a second coating layer 23 on one side of a paper substrate 21 using a second coating liquid, and a step (1) of 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 and drying the coating layer. The same coating liquid may be applied (reapplied) in succession. The method for applying the coating liquid is not particularly limited, and any known coating method can be used, 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, curtain coating method, etc. Among these, flexographic printing is preferred because of 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 applied coating liquid, and examples thereof include reduced pressure 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 above-mentioned embodiment. For example, in the laminate 10 shown in FIG. 1, the coating layer 12 is provided on the entire one side of the paper substrate 11, but the coating layer 12 may be provided on a part of the one side of the paper substrate 11. In this case, it is preferable that another coating layer is provided in the area of ​​the 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 mentioned.

[0070] In the laminate 20 shown in Fig. 2, the first coating layer 22 is provided on the entire second coating layer 23, but the first coating layer 22 may be provided on 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 (visible side). For example, a varnish layer formed from a varnish composition may be mentioned.

[0071] <White ink for underlay> In order to further improve the sharpness of images of color printing layers printed on a paper base material, white ink is applied to the side of the color layer opposite the visible side to provide a white underlay (also called a white coating layer or white printing layer). This white ink is called white underlay white ink. From the viewpoints of adhesion to the substrate and abrasion resistance, it is preferable to use an ink containing an acrylic resin as the white ink for the underlay. The white pigment is not particularly limited, but titanium oxide is preferable. In the surface printing illustrated in FIG. 2, for example, a white ink for whitening is printed on a substrate to form a white printed layer, and the water-based ink of the present invention is printed thereon to form a printed layer (color printed layer). As the white ink for underprinting, a water-based ink containing the water-based liquid composition of the present invention and a white pigment can be used.

[0072] <Primer layer> 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, the aqueous primer of the present invention is applied onto a paper substrate to form a primer layer, a white ink for whitening is printed on top of that onto the substrate to form a white printing layer, and then the aqueous ink of the present invention is printed on top of that to form a printing layer (color printing layer).

[0073] Other layers than the primer layer may be provided on the substrate, such as a resin layer, a magnetic layer, a heat-sensitive layer, a photosensitive layer, etc.

[0074] <Varnish layer> 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 that forms the varnish layer. In the laminate illustrated in FIG. 1, for example, a color print layer is formed on a paper base material, and a varnish layer, which serves as the uppermost layer, is formed thereon. In the surface printing illustrated in FIG. 2, for example, a white print layer is formed on a paper substrate, a color print layer is formed on that, and a varnish layer serving as the top layer is formed on that. In addition, in the laminate illustrated in FIG. 1, for example, a varnish layer may be formed on the surface opposite to the coating layer on the paper substrate coated with a coating liquid containing the aqueous liquid composition of the present invention. In the surface printing illustrated in FIG. 2, for example, a varnish layer may be formed on the surface opposite to the white print layer on the paper substrate.

[0075] <label> A label according to one embodiment of the present invention is obtained by using the laminate according to the present embodiment described above. The label can be used for various labels attached to packaging containers of beverages, seasonings, side dishes, bento boxes, and other foods and beverages, and daily necessities such as cosmetics. In particular, the label is suitable for use as a label for products whose packaging container is a plastic bottle, for example, as a label for bottled beverages and beverages. The label of the present embodiment can also be used suitably even if the packaging container is made of paper. Examples of bottled beverages include beverages, liquid seasonings (dressings, noodle soup, soy sauce, liquid miso, etc.), edible oils, etc. The label may be in the form of, for example, a wraparound label.

[0076] <Packaging material> Examples of applications of packaging materials include packaging materials for various items such as food, daily necessities, miscellaneous goods, and sanitary products. The shape of the packaging material is not particularly limited, and examples thereof include bags such as bottom-sealed bags, side-sealed bags, three-side-sealed bags, pillow bags, gusset bags, square-bottom bags, and stand-up bags.

[0077] According to this embodiment, as shown in the examples described later, an acrylic resin (A) having a specific acid value and an acrylic resin (B) having a specific acid value and a specific glass transition temperature are combined in a specific ratio as the binder resin, a specific solvent (C) and an aqueous medium (D) are combined as the medium so that the volatile content / C ratio is a specific ratio, and a large particle size wax (E) and a small particle size wax (F) having a specific average particle size are used in combination, thereby obtaining an aqueous liquid composition for coating on paper substrates which has excellent gloss, heat resistance, and abrasion resistance of the coating film, has good adhesion to the paper substrate, can reduce plate tangling when used in flexographic printing, and also has good storage stability of the liquid and good dispersibility when a pigment is 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 as long as it does not deviate from the gist of the invention. In the following, "NV" stands for non-volatile content (solid content). "%" as a unit of content means "% by mass" unless otherwise specified. "Parts" means "parts by mass" unless otherwise specified.

[0079] [Raw materials used] <Acrylic resin (A)> The following compounds were used as the acrylic resin (A) and the comparative component (A'). A-1: Manufactured by BASF Japan Ltd., product name "Joncryl 52J", weight average molecular weight 1,700, acid value 238 mg KOH / g, glass transition temperature 56°C, solid content 60 mass%. A-2: Seiko PMC Corporation, product name "Hi-Loss X-NL-1189", weight average molecular weight 11,000, acid value 90 mg KOH / g, glass transition temperature 28°C, 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 mg KOH / g, glass transition temperature 84°C, solid content 34% by mass. A'-4: Seiko PMC Corporation, product name "Hi-Loss X-AW-36H", weight average molecular weight 15,000, acid value 60 mg KOH / g, glass transition temperature 53°C, solid content 25% by mass. A'-5: Seiko PMC Corporation, product name "Hi-Loss X-UL-1191", weight average molecular weight 6,500, acid value 270 mg KOH / g, glass transition temperature 128°C, solid content 32% by mass.

[0080] <Acrylic emulsion resin (B)> The following compounds were used as the acrylic emulsion resin (B) and the 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 mass%. B-2: Seiko PMC Corporation, product name "Hi-Loss XM-141", acid value 19 mg KOH / g, glass transition temperature 15°C, 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 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 mass%. B-5: Seiko PMC Corporation, product name "Hi-Loss X-QE-1042", acid value 33 mg KOH / g, glass transition temperature 53°C, solid content 41% by mass. B'-6: 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: Seiko PMC Corporation, product name "Hi-Loss X-HE-2342", acid value 125 mg KOH / g, glass transition temperature 16°C, solid content 44% by mass. B'-8: Seiko PMC Corporation, product name "Hi-Loss X-JE-1113", acid value 42 mg KOH / g, glass transition temperature -24°C, solid content 43% by mass. B'-9: Seiko PMC Corporation, product name "Hi-Loss X-NE-2186", acid value 59 mg KOH / g, glass transition temperature 107°C, 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 10, solid content 40 mass%. <Small particle size wax (F)> F-1: Manufactured by Mitsui Chemicals, Inc., product name "Chemipearl W-700", average particle size 1 μm, penetration less than 1, solid content 40 mass%. <Pigments> Pigment: Pigment Blue 15:3 (manufactured by BASF Japan Ltd., product name "Heliogen Blue D7088", solid content 100% by mass). Titanium oxide: Pigment White 6 (manufactured by Ishihara Sangyo Kaisha, Ltd., product name "CR-90", solid content 100% by mass) <Optional ingredients> Defoamer: BYK Japan Co., Ltd., product name "BYK-094", solid content 96% by mass. Curing agent: Carbodiimide-based curing agent (manufactured by Nisshinbo Chemical Inc., product name "Carbodilite E-02", non-volatile content 40% by mass)

[0084] [Evaluation method] <Dispersibility> The dispersibility of the pigment-containing water-based inks was evaluated by 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 ingredients were mixed and dispersed using a bead mill (manufactured by Shinmaru Enterprises Co., Ltd., product name "Dyno Mill", 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. ◯: Dispersion treatment is possible using a bead mill, and the color development of the resulting water-based ink when applied is good. △: Dispersion processing is possible using a bead mill, but the color development of the resulting water-based ink is insufficient (the coating film is whitish in the case of blue pigments, and the coating film has low gloss in the case of titanium oxide). ×: The dispersion liquid does not pass through the bead mill, causing clogging inside the Dyno Mill.

[0085] <Storage stability> The storage stability of the water-based ink (or the water-based liquid composition when no pigment was blended) was evaluated by the following method. The water-based ink obtained by the dispersion treatment was placed in a 250 ml plastic container and stored in a 40°C environment for one month. After storage, the condition of the water-based ink was visually observed and evaluated according to the following evaluation criteria. ○: No change from the condition before storage for one month. △: The viscosity has increased slightly compared to before storage for one month, but there is no change in appearance. ×: Viscosity has increased significantly or aggregates have formed compared to before storage for one month.

[0086] The printed layer formed by printing an aqueous ink (or an aqueous liquid composition when no pigment was added) on a paper substrate was evaluated for gloss, reduction in plate tangling, adhesion, heat resistance, and abrasion resistance using the methods described below. <Glossiness> A gloss meter (manufactured by BYK Gardner, product name "micro-TRI-gloss") was used to measure the 60° gloss (60° specular gloss) of the surface on the printed layer side, and the gloss of the printed layer was evaluated according to the following evaluation criteria. A higher 60° gloss indicates better gloss. ○: 60° gloss is 70% or more. △: 60° gloss is 60% or more but less than 70%. ×: 60° gloss is less than 60%.

[0087] <Reduced plate tangling> The aqueous ink obtained in each example (the aqueous liquid composition when no pigment was blended) was used for printing by the following method. A CI-type flexographic printing machine (KBA-Flexotecnica) was used to print the printed matter on a commercially available coated paper (Oji Paper Co., Ltd., product name "OK Topcoat Plus", 104.7 g / m2 (104.7 g / m2)). 2 The print was made on a 1000LPI anilox roll at 4cc / m for 10 minutes at a speed of 80m / min. 2The drying conditions for the printed layer were an intercolor dryer at 90°C and a tunnel dryer at 90°C. The 5% dot area of ​​the obtained print was visually observed, and the plate entanglement reduction ability was evaluated according to the following evaluation criteria. ◯: No thickening of the 5% dots is observed, or some thickening is observed but the dots are not connected to each other. △: 5% thickening of the dots is observed, and the dots are slightly connected to each other. ×: 5% The shape of the dots is distorted and the dots are clearly connected to each other.

[0088] <Adhesion> Cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed layer of the laminate obtained in each example, and the cellophane tape was then quickly 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 using the following evaluation criteria. ◯: The ratio of the area of ​​the peeled printing layer to the total area of ​​the printing layer is more than 0% and 3% or less. △: The ratio of the area of ​​the peeled printing layer to the total area of ​​the printing layers is more than 3% and less than 30%. ×: The ratio of the area of ​​the peeled printed layer to the total area of ​​the printed layers is 30% or more.

[0089] <Heat resistance> The glossy side of the aluminum foil was placed on the printed surface of the laminate obtained in each example, and a load of 200°C and 0.2 MPa was applied for 2 seconds using a heat seal tester (manufactured by Tester Sangyo Co., Ltd.) The laminate was peeled off by hand, and the presence or absence of peel resistance and the fusion state of the printed layer were visually confirmed and evaluated according to the following criteria. ◯: There is no peel resistance and no fusion of the printed layer. △: Weak peel resistance, no fusion of the printed layer. ×: Peel resistance present, fusion of the printed layer present.

[0090] <Abrasion resistance> A cloth (3 cm gold cloth) was placed on the printed surface of the laminate obtained in each example, and rubbed back and forth 100 times under a load of 500 gf using a Gakushin type rub fastness tester (manufactured by Tester Sangyo Co., Ltd.) After that, the product was evaluated according to the following criteria in accordance with JIS L 0805. ○: Color chart is from No. 5 to No. 4-5. △: Color chart is No. 4 to No. 3. ×: Color chart is from 2-3 to 1.

[0091] <Examples 1 to 44> Examples 1 to 26 are working examples, and Examples 27 to 44 are comparative examples. Examples 1 to 25 and Examples 27 to 44 are examples in which an aqueous ink containing an aqueous liquid composition and a pigment was prepared. Example 26 is an example in which an aqueous liquid composition not containing a pigment was prepared as the aqueous medium.

[0092] A water-based ink was obtained by mixing acrylic resin (A), acrylic emulsion resin (B), solvent (C), water (D), large particle size wax (E), small particle size 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), large particle size wax (E), small particle size wax (F), and defoamer according to the composition shown in the table. The resulting aqueous ink or aqueous medium was used as a coating liquid to produce a laminate by the following method.

[0093] (Example of laminate manufacturing) The base paper was coated paper (manufactured by Oji Paper Co., Ltd., product name "OK Top Coat Plus", 104.7 g / m 2 ) was used. Cell volume 10.0cm 3 / m 2 A flexo hand proofer equipped with an anilox roll was used as an applicator to apply the coating solution of each example to one side of the paper substrate so that the coating amount after drying was 2.0 g / m 2 The coating (printing) was then performed so that the coating was as follows: Then, the coating was dried for 1 minute with hot air from a dryer to form a printed layer (coating film). When the coating liquid was an aqueous ink, a blue or white printed layer was obtained, and when the coating liquid 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 by the method described above. The storage stability of the water-based ink or water-based medium was evaluated by the method described above. The printed layer of the laminate was evaluated for each item shown in the table by the method described above. The results are shown in the table. A blank cell in the table means that the component is not blended (amount blended: 0 parts by mass). NV in the table means the non-volatile (solid) content of each component (unit: mass%). It was confirmed that the aqueous liquid compositions of Examples 1 to 44 had flash points of over 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 results in the table, in Examples 1 to 26, the coating film had excellent gloss, heat resistance, and abrasion resistance, and also had good adhesion to paper substrates. When used in flexographic printing, it was possible to reduce plate tangling. In addition, aqueous liquid compositions and aqueous inks were obtained that had good storage stability of the liquid and good dispersibility when a pigment was added.

[0110] In Example 26, which is an embodiment of an aqueous liquid composition containing no pigment, when B / A was set to less than 0.25, a similar tendency to that in Comparative Example 35 was observed. In addition, in Example 26, when volatile content / C was set to more than 20, a similar tendency to that in Comparative Example 38 was observed.

[0111] (Application example 1) In the laminate manufacturing example, a white printed layer was provided between the substrate and the printed layer, and a varnish layer (top layer) was further provided on the visible side of the printed layer to form a laminate. The white printed layer was formed using the water-based ink of Example 24, and the varnish layer was formed using the water-based liquid composition of Example 26. The laminate of Application Example 1 was also evaluated to be excellent, similarly to Examples 1 to 26.

[0112] (Application example 2) In the laminate production example described above, a laminate was prepared by laminating an LLDPE film by melt extrusion of LLDPE (product name "Kernel KC570S", manufactured by Japan Polyethylene Co., Ltd.) on the surface opposite the printed layer of the coated paper substrate. The laminate obtained in Application Example 2 was also evaluated to be excellent, similarly to Examples 1 to 26. [Explanation of symbols]

[0113] 10, 20 laminate 11, 21 Paper base material 12 Coating layer 22 First coating layer 23 Second Coating Layer

Claims

1. An aqueous liquid composition for use in coating a paper substrate, comprising: An acrylic resin (A) having an acid value of 80 mgKOH / g or more and 260 mgKOH / g or less (excluding acrylic emulsion resins); An acrylic emulsion resin (B) having an acid value of 10 mgKOH / g or more and less than 80 mgKOH / g and a glass transition temperature of 0 to 60°C; In the following formula (c1), n ​​is 1, R １ and R ２ is a hydrogen atom; n is 2 in the following formula (c1); R １ and R ２ is a hydrogen atom; n is 3 in the following formula (c1); R １ and R ２ is a hydrogen atom; １ Or R ２ and monoalkylene glycol monoalkyl ethers in which one of the groups is a hydrogen atom and the other is an alkyl group, and １ Or R ２ a solvent (C) which is at least one selected from the group consisting of polyalkylene glycol monoalkyl ethers, one of which is a hydrogen atom and the other is an alkyl group; An aqueous medium (D) (excluding the solvent (C)); A large particle size wax (E) having an average particle size of 1.5 μm or more; and a small particle size wax (F) having an average particle size of less than 1.5 μm; the content of the solid content of the acrylic resin (A) is 8.2 to 60 mass% and the content of the solid content of the acrylic emulsion resin (B) is 20 to 82 mass% relative to the total mass of the solid content of the aqueous liquid composition; B / A, which represents a mass ratio of the solid content of the acrylic emulsion resin (B) to the solid content of the acrylic resin (A), is 0.25 / 1 to 10 / 1; The mass ratio of the total volatile matter to the solvent (C) is 3 / 1 to 20 / 1, An aqueous liquid composition for coating a paper substrate, 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 mass% relative to the total mass of the solid content in the aqueous liquid composition. R １ -O-(AO)n-R ２ (c1) (R in the formula １ , R ２ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms; R １ and R ２ may be the same or different, A is a linear or branched alkylene group having 2 to 4 carbon atoms, n is an integer of 1 to 6, and when n is 2 or more, the n As may be the same or different.

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

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

4. 2. The aqueous liquid composition according to claim 1, having a flash point of 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 mass% based on 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 mass% based on the total mass of the aqueous liquid composition.

7. The large particle size wax (E) has an average particle size of 1.5 μm or more and 5 μm or less and a penetration of 7 to 12, 2. The aqueous liquid composition according to claim 1, wherein the small particle size wax (F) has an average particle size of 0.4 μm or more and less than 1.5 μm and a penetration of 0.3 to 7.

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

9. The aqueous liquid composition according to claim 1 for use with a hardener.

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

11. An aqueous ink comprising the aqueous liquid composition according to claim 1 and a pigment.

12. A laminate comprising a printed layer formed by printing the water-based ink according to claim 11 on a paper substrate.

13. A laminate comprising a white printed layer formed by printing an underlay white ink on a paper base material, and a printed layer formed by printing the water-based ink according to claim 11 on the white printed layer.

14. 12. A laminate comprising: a primer layer formed on a paper substrate by coating an aqueous primer comprising the aqueous liquid composition according to claim 1; a white printed layer formed on the primer layer by printing a white ink for whitening; and a printed layer formed on the white printed layer by printing the aqueous ink according to claim 11.

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

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

17. A laminate comprising a paper substrate, one or both of a primer layer not containing a pigment and provided in contact with the paper substrate, and a varnish layer not containing a pigment and provided as the uppermost layer, and a printed layer containing a pigment, and at least one of the primer layer, the varnish layer, and the printed layer containing a pigment is a layer formed by applying a coating liquid containing the aqueous liquid composition described in claim 1.

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

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

20. A label or packaging material obtainable using the laminate according to claim 15.

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