Aqueous resin composition, aqueous coating liquid for plastic film, and laminate

Abstract

The present invention provides an aqueous resin composition suitable for use in aqueous coating solutions that can form a transparent coating layer with good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance. [Solution] This is an aqueous resin composition used in an aqueous coating liquid having a haze value of 15% or less. The aqueous resin composition contains an emulsion of polyolefin resin (polyolefin resin emulsion) having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g, as well as polyethylene wax and / or paraffinic wax. The content of polyolefin resin is 60 to 95% by mass and the content of wax is 4 to 25% by mass relative to the mass of solids of the aqueous resin composition, and the mass ratio of polyolefin resin:wax is 1:0.043 to 1:0.300.

Description

Technical Field

[0001] The present invention relates to an aqueous resin composition, an aqueous coating liquid, and a laminate.

Background Art

[0002] Resin containers, packaging materials, and labels such as plastics are indispensable in various fields such as foods, cosmetics, and daily necessities because they are lightweight, durable, and mass-producible. For example, biaxially oriented polypropylene (OPP) is a material with gloss and excellent moisture-proof and transparency properties, and is used for pack films of vegetables and fruits, transparent window parts of paper kraft packs, and the like. In addition, polyethylene terephthalate (PET) has high transparency and allows the contents to be clearly seen, and thus is widely used, for example, as container packaging for foods such as salads, prepared foods, sushi, and sashimi. In addition, polystyrene (PS) is also one of the general-purpose resins, and is used in various applications taking advantage of its transparency, such as small food containers, dessert cups, and DVD cases.

[0003] In addition, inks used for printing resin containers and packaging materials as described above, from the viewpoint of global environmental protection and the like, the demand for aqueous inks with a lower amount of organic solvent emissions during printing and residual solvents in printed materials is increasing.

[0004] To date, various proposals have been made to improve the various physical properties of water-based inks, including water-based inks themselves, water-based pigment dispersions for inclusion in water-based inks, and water-based varnish compositions. For example, when laminating the printed surface of paper containers, packaging paper, and kraft tape after printing with water-based ink to provide durability and moisture resistance, a water-based printing ink composition for lamination has been proposed that prevents the printed water-based ink from adhering to the laminate surface (Patent Document 1). In addition, a water-based pigment ink for textile inkjet printing with excellent wet abrasion fastness has been proposed, which can be printed on printing papers such as plain paper, coated paper, and specialty paper, as well as substrates such as cloth, wood substrates, metal substrates, glass substrates, and plastic substrates (Patent Document 2). Furthermore, a water-based pigment dispersion that can achieve both gloss and lightfastness in inkjet printing inks, and an inkjet printing ink using such a water-based pigment dispersion have also been proposed (Patent Document 3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-140497 [Patent Document 2] International Publication No. 2020 / 090212 [Patent Document 3] Japanese Patent Publication No. 2021-31616 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] As described above, in order to improve various physical properties of water-based inks, water-based inks and additives to be included in water-based inks have been studied for some time. The present inventors have investigated forming a printed layer using the water-based ink composition proposed in Patent Document 1, the water-based pigment ink proposed in Patent Document 2, and the inkjet printing ink proposed in Patent Document 3. As a result, it was found that the printed layer formed with the above-mentioned conventional inks was not good in at least one of the following properties: adhesion to the substrate (hereinafter referred to as "substrate adhesion"), blocking resistance, heat resistance, scratch resistance, and transparency, and that there is room for improvement.

[0007] On the other hand, in packaging materials such as shrink labels, a hot-melt adhesive is often applied to a film that has a printed layer made of ink. Therefore, in order to make an ink suitable for such applications, it is also required that the ink be able to form a printed layer that exhibits appropriate adhesion when a hot-melt adhesive is applied (hereinafter, this characteristic will be referred to as "hot-melt adhesiveness").

[0008] Therefore, the present invention aims to provide an aqueous resin composition that can be suitably used in aqueous coating solutions that can form a coating layer that has good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, as well as transparency. [Means for solving the problem]

[0009] In other words, the present invention provides an aqueous resin composition for use in an aqueous coating solution having a haze value of 15% or less of a coating film, comprising a resin emulsion and a wax, wherein the resin emulsion comprises a polyolefin resin emulsion containing a polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g, the wax comprises at least one selected from the group consisting of polyethylene-based waxes and paraffin-based waxes, the content of the polyolefin resin is 60 to 95% by mass and the content of the wax is 4 to 25% by mass relative to the mass of the solid content of the aqueous resin composition, and the mass ratio of the content of the wax to the content of the polyolefin resin is the polyolefin resin:wax = 1:0.043 to 1:0.300. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an aqueous resin composition that can be suitably used in aqueous coating solutions that can form a coating layer having good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, as well as transparency. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view showing an example of the arrangement of layers constituting a laminate according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view showing another example of the arrangement of layers constituting a laminate according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0013] In this disclosure, "aqueous" in "aqueous resin composition" and "aqueous coating liquid" means including an aqueous medium. "Aqueous medium" means a liquid medium containing at least water. "Liquid medium" means a volatile liquid such as water and organic solvents. "Volatile components" means volatile components such as water and organic solvents among the components contained in the aqueous resin composition or aqueous coating liquid. Specifically, the heat residue obtained by a measurement method in accordance with JIS K 5601-1-2:2008 is defined as the solid component (also called non-volatile component), and the rest is defined as volatile components. "Coating layer" means a layer formed by coating an aqueous resin composition or an aqueous coating liquid using an aqueous resin composition by printing and coating, etc., and by the volatilization of volatile components in the aqueous resin composition or aqueous coating liquid.

[0014] Furthermore, in this disclosure, "aqueous resin composition" means a composition used in an aqueous coating solution (resin composition for aqueous coating solutions). An aqueous coating solution means a liquid substance applied to a substrate and is obtained using an aqueous resin composition. Specifically, depending on the type of aqueous coating solution, its application, and the coating method, an aqueous coating solution can be prepared by adding an appropriate additive to the aqueous resin composition or by adding a liquid medium to adjust the viscosity to an appropriate level. Examples of aqueous coating solutions include aqueous inks, aqueous varnishes, aqueous mediums, aqueous primers, and aqueous reducers. For example, when preparing an aqueous ink as an aqueous coating solution, an aqueous ink can be prepared using an aqueous ink resin composition containing a colorant (pigment and / or dye) in the aqueous resin composition. In this disclosure, a composition containing a colorant in the aqueous resin composition may be referred to as an "aqueous ink resin composition." Therefore, in the case of the above-mentioned aqueous ink resin composition, the content of component A (mass%) relative to the solid content of the aqueous resin composition in this disclosure can be defined as the content of component A (mass%) relative to the mass of the solid content (excluding colorants) of the aqueous ink resin composition.

[0015] In this disclosure, "acrylic resin" means 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". The "~" indicating a numerical range means that the values ​​written before and after it are included as the lower and upper limits. The lower and upper limits of the numerical ranges in this disclosure can be arbitrarily combined to form new numerical ranges.

[0016] The inventors investigated an aqueous resin composition for aqueous coating liquids that can form a transparent coating layer with good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance. Specifically, experiments and studies were conducted using aqueous resin compositions containing a resin emulsion and a wax. As a result, it was found that the desired aqueous resin composition can be obtained by including a polyolefin resin emulsion containing a polyolefin resin with a melting point and acid value within a specific range, and a specific wax, in a specific amount range and a specific mass ratio relative to the mass of solids in the aqueous resin composition.

[0017] <Aqueous resin composition> An aqueous resin composition according to one embodiment of the present invention (which may be simply referred to as "aqueous resin composition" in this disclosure) is a composition used in an aqueous coating liquid having a haze value of 15% or less. This aqueous resin composition contains a resin emulsion and a wax. The resin emulsion contains a polyolefin resin emulsion containing a polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g. The wax contains at least one selected from the group consisting of polyethylene-based waxes and paraffin-based waxes. Furthermore, the content of polyolefin resin is 60 to 95% by mass and the content of wax is 4 to 25% by mass relative to the mass of solids of the aqueous resin composition. Moreover, the mass ratio of the wax content to the polyolefin resin content is polyolefin resin:wax = 1:0.043 to 1:0.300.

[0018] By using the aqueous resin composition having the above configuration, an aqueous coating liquid can be obtained that forms a coating layer having good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, and also having transparency.

[0019] Specific examples of the coating layer having transparency include those having a haze value of the coating film of 15% or less. The above haze value is preferably 10% or less. The haze value is measured using a haze computer (trade name "H2-2P", manufactured by Suga Test Instruments Co., Ltd.) under room temperature (25 °C) conditions. The haze values of three locations of a coating film formed by coating an aqueous coating liquid containing the aqueous resin composition on a plastic film substrate by flexographic printing or gravure printing (= measured value - haze value of the substrate) are measured, and the average value thereof is calculated.

[0020] In addition, as a coating layer having good scratch resistance, specifically, a coating film obtained by coating an aqueous coating liquid containing the aqueous resin composition is rubbed with a hard object in the width direction, and the ratio of the area of the coating film that has peeled off with respect to the test area of the coating film after 10 reciprocations is less than 20%. An aqueous resin composition excellent in scratch resistance can be provided. Hereinafter, regarding the aqueous resin composition, the preferred configuration and the like will be mainly described from the viewpoint of easily obtaining a coating layer having each of the above characteristics.

[0021] 〔Resin emulsion〕 The aqueous resin composition contains a resin emulsion. The resin, which is the dispersed substance (solid content) dispersed in the dispersion medium (aqueous medium) in the resin emulsion, is a component constituting the solid content of the aqueous resin composition. The resin emulsion includes at least a polyolefin resin emulsion containing a specific polyolefin resin described below. The aqueous resin composition may contain, in addition to the specific polyolefin resin emulsion described below, other polyolefin resin emulsions (other polyolefin resin emulsions), an acrylic resin emulsion, and a urethane resin emulsion described later.

[0022] (Polyolefin resin emulsion) The aqueous resin composition contains a polyolefin resin emulsion. This polyolefin resin emulsion is an emulsion of a polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g. This specific polyolefin resin and its emulsion may be simply referred to as "polyolefin resin" and "polyolefin resin emulsion," respectively. The polyolefin resin emulsion is an emulsion formed by colloidally dispersing the polyolefin resin in the aqueous resin composition. By using this specific polyolefin resin emulsion, it is possible to contribute to the formation of a coating layer that has good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, as well as transparency.

[0023] The melting point of polyolefin resin is 60 to 97°C. Using a polyolefin resin with a melting point within this range contributes to the formation of a coating layer with good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance. If the melting point of the polyolefin resin is below 60°C, the coating layer will have poor blocking resistance and heat seal blocking resistance, as well as insufficient substrate adhesion, hot melt adhesive properties, and scratch resistance. On the other hand, if the melting point of the polyolefin resin exceeds 97°C, the substrate adhesion of the coating layer and the scratch resistance of the OPP substrate will be poor. The melting point of the polyolefin resin is preferably 63 to 90°C, and more preferably 67 to 80°C from the viewpoint of easily obtaining a coating layer with even better substrate adhesion, blocking resistance, heat seal blocking resistance, and scratch resistance. The melting point of the polyolefin resin can be obtained by differential scanning calorimetry (DSC).

[0024] The acid value of polyolefin resins is 13 to 60 mgKOH / g. Using polyolefin resins with an acid value within this range contributes to the formation of a coating layer with good substrate adhesion, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, while also improving the storage stability of the aqueous resin composition. If the acid value of the polyolefin resin is less than 13 mgKOH / g, the substrate adhesion, hot melt adhesive properties, and scratch resistance of the coating layer are poor. On the other hand, if the acid value of the polyolefin resin exceeds 60 mgKOH / g, the storage stability of the aqueous resin composition, substrate adhesion to PET and PS substrates, heat seal blocking resistance to PET substrates, hot melt adhesive properties to PET substrates, and scratch resistance to PET and PS substrates are poor. The acid value of the polyolefin resin is preferably 14 to 55 mg KOH / g, and more preferably 16 to 45 mg KOH / g from the viewpoint of obtaining a coating layer with even better substrate adhesion, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance. The acid value of the polyolefin resin is expressed in milligrams as the amount of potassium hydroxide required to neutralize acid groups such as carboxyl groups per gram of sample solid content, and is measured in accordance with JIS K 5601-2-1:1999.

[0025] The polyolefin resin content, which is the solid component of the polyolefin resin emulsion in the aqueous resin composition, is 60 to 95% by mass, based on the mass of the solid component of the aqueous resin composition. If the polyolefin resin content is less than 60% by mass relative to the mass of the solid component of the aqueous resin composition, the coating layer will have poor substrate adhesion, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, and sufficient transparency will not be obtained. On the other hand, if the polyolefin resin content exceeds 95% by mass relative to the mass of the solid component of the aqueous resin composition, the coating layer will have poor blocking resistance, heat seal blocking resistance, and scratch resistance. By setting the polyolefin resin content to 60 to 95% by mass relative to the mass of the solid component of the aqueous resin composition, it is possible to contribute to the formation of a coating layer that has good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, as well as transparency. The polyolefin resin content relative to the mass of solids in the aqueous resin composition is preferably 65 to 92% by mass, from the viewpoint of substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, scratch resistance, and improved transparency.

[0026] Specific examples of polyolefin resins include polyethylene (PE), polypropylene (PP), polybutylene, polybutene, hydrogenated polybutene, polyisobutylene, hydrogenated polyisobutylene, and olefin copolymers. These may be used individually or in combination of two or more. Examples of polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). Examples of polypropylene include atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, oxidized polypropylene, chlorinated polypropylene, crosslinked polypropylene, and modified polypropylene. Examples of olefin copolymers include ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, and polypropylene-polyethylene copolymer, as well as other olefin copolymers obtained by copolymerizing two or more of ethylene, propylene, and butylene. Furthermore, the various polyolefin resins listed above may also be modified polyolefin resins in which amino groups, carboxyl groups, hydroxyl groups, acryloyl groups, and polymer chains are introduced to the polyolefin chain; oxidized polyolefin resins in which a portion of the polyolefin chain is oxidized; or halogenated polyolefin resins in which a portion is treated with a halogen.

[0027] The aqueous resin composition uses an emulsion of the polyolefin resin listed above. The polyolefin resin emulsion may be an emulsion of resin obtained using raw materials obtained from fossil fuels, or an emulsion of resin obtained from biomass-derived raw materials. In addition, the polyolefin resin emulsion may be manufactured by conventional methods or a commercially available product may be used. Among the polyolefin resin emulsions, at least one selected from the group consisting of polypropylene resin emulsion, polyethylene resin emulsion, and polypropylene-polyethylene copolymer resin emulsion is preferred. In other words, the polyolefin resin preferably contains at least one selected from the group consisting of polypropylene resin, polyethylene resin, and polypropylene-polyethylene copolymer.

[0028] Polypropylene resin emulsion is an emulsion formed by colloidally dispersing polypropylene resin in an aqueous resin composition. The aqueous resin composition may use the polypropylene resin emulsion alone, or it may be used in combination with other polyolefin resin emulsions, such as polyethylene resin emulsions or polypropylene-polyethylene copolymer resin emulsions described later.

[0029] A polyethylene resin emulsion is an emulsion formed by colloidally dispersing polyethylene resin in an aqueous resin composition. The aqueous resin composition may use the polyethylene resin emulsion alone, or it may be used in combination with other polyolefin resin emulsions, such as the polypropylene resin emulsion mentioned above or the polypropylene-polyethylene copolymer resin emulsion described later.

[0030] A polypropylene-polyethylene copolymer resin emulsion is an emulsion formed by colloidally dispersing a polypropylene-polyethylene copolymer resin in an aqueous resin composition. The arrangement of monomer units in the polypropylene-polyethylene copolymer is not particularly limited and may be a block copolymer, an alternating copolymer, a random copolymer, or a graft copolymer. The aqueous resin composition may use the polypropylene-polyethylene copolymer resin emulsion alone, or it may be used in combination with other polyolefin resin emulsions, such as the polypropylene resin emulsion or polyethylene resin emulsion described above.

[0031] Examples of commercially available polyolefin resin emulsions include the "Arrowbase" series (manufactured by Unitika Corporation), the "Aurolene" series (manufactured by Nippon Paper Industries Co., Ltd.), and the "Aptrock" series (manufactured by Mitsubishi Chemical Corporation).

[0032] (Acrylic resin emulsion) The aqueous resin composition may optionally further contain an acrylic resin emulsion. The acrylic resin emulsion is a type of water-dispersible acrylic resin, and for example, an emulsion-type acrylic resin having a core-shell structure can be used. The core-shell type acrylic resin emulsion is composed of a core portion containing a relatively high molecular weight hydrophobic acrylic resin and a shell portion containing a relatively low molecular weight hydrophilic acrylic resin. The core portion and the shell portion may be bonded together by a crosslinking agent.

[0033] By incorporating an acrylic resin emulsion along with the polyolefin resin emulsion described above into the aqueous resin composition, a coating layer with better blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance can be easily obtained. From this viewpoint, an acrylic resin emulsion containing an acrylic resin with a glass transition temperature (sometimes abbreviated as "Tg" in this disclosure) of 75°C or higher is preferred. The glass transition temperature of the acrylic resin is more preferably 80°C or higher, and more preferably 140°C or lower. The glass transition temperature of the acrylic resin is measured in accordance with JIS K 7121 as follows: Using a differential scanning calorimeter, the glass transition temperature is determined from the intersection of the baseline and the tangent to the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of acrylic resin emulsion from -100°C to 160°C at a rate of 20°C / min.

[0034] When an aqueous resin composition contains an acrylic resin emulsion containing an acrylic resin with a glass transition temperature of 75°C or higher, it is preferable to reduce the acrylic resin content in the aqueous resin composition to less than the polyolefin resin content. Specifically, the acrylic resin content in the aqueous resin composition is preferably 35% by mass or less, more preferably 32% by mass or less, and preferably 10% by mass or more, relative to the polyolefin resin content. By incorporating the acrylic resin emulsion into the aqueous resin composition in the above specific ratio relative to the polyolefin resin content, it is easier to obtain a coating layer with even better blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance. The above mass ratio can be determined by {acrylic resin content / polyolefin resin content} × 100 based on the total mass of the aqueous resin composition, or by {acrylic resin content / polyolefin resin content} × 100 based on the mass of the solids in the aqueous resin composition.

[0035] The acrylic resin in an acrylic resin emulsion is obtained by polymerizing a monomer component that includes (meth)acrylate and, if necessary, a monomer other than (meth)acrylate. When producing an acrylic resin with an acid value, it is preferable to use an unsaturated carboxylic acid as the monomer 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. Emulsion polymerization is preferred among these. Emulsion polymerization is a method of polymerizing monomer components in an aqueous medium in the presence of an emulsifier. The acrylic resin emulsion may be produced by compounding a core and a shell after producing them separately. Alternatively, it may be produced by multi-step emulsion polymerization. The acrylic resin emulsion may be self-crosslinking type.

[0036] Commercially available acrylic resin emulsions may be used. Examples of commercially available acrylic resin emulsions include the following products from Seikoh PMC: "Hyros XE-JE-1056", "Hyros-X-KE-1148", "Hyros-XJ-140A", "Hyros-X-ME-2039", "Hyros-X-PE-2109", and "Hyros-X-PE-1126"; "NeoKryl XK-110", "NeoKryl A-662", and "NeoKryl XK-12" from Covestro Coating Resins; and "JonKryl PDX-7734", "JonKryl PDX-7158", and "JonKryl PDX-7630A" from BASF Japan. One type of acrylic resin emulsion may be used alone, or two or more types may be used in combination.

[0037] (urethane resin emulsion) The aqueous resin composition may further contain a urethane resin emulsion as needed. By including a urethane resin emulsion in the aqueous resin composition along with the polyolefin resin emulsion described above, it is easier to obtain a coating layer with better substrate adhesion and lamination suitability. The urethane resin emulsion is a type of water-dispersible urethane resin, and for example, an emulsion-type urethane resin having a core-shell structure can be used. The core-shell type urethane resin emulsion is composed of a core containing a relatively high molecular weight hydrophobic urethane resin and a shell containing a relatively low molecular weight hydrophilic urethane resin. The core and shell may be bonded together by a crosslinking agent. By including a urethane resin emulsion in the aqueous resin composition along with the polyolefin resin emulsion described above, it is easier to obtain a coating layer with improved dry lamination strength. Dry lamination strength refers to the adhesive strength between the coating layer and the film in a laminate (laminate film) obtained by a dry lamination method in which a film such as a sealant film is pressed onto a coating layer provided on a substrate via an adhesive layer.

[0038] The dry lamination strength described above is preferably 0.8 to 2.0 N / 15 mm, which is the dry lamination strength between the coating layer, formed by applying an aqueous coating liquid using an aqueous resin composition to a substrate (the first substrate described later), and a substrate (the second substrate described later), which is placed via an adhesive layer. By setting the dry lamination strength within the above range, a laminate that does not easily peel off can be obtained. From this viewpoint, the dry lamination strength described above is more preferably 1.2 to 2.0 N / 15 mm.

[0039] As for the urethane resin emulsion, from the viewpoint of achieving higher dry laminate strength as described above, a urethane resin emulsion containing a urethane resin with a glass transition temperature of 30 to 120°C is preferred. The glass transition temperature of the urethane resin is more preferably 40 to 110°C, and even more preferably 50 to 100°C. The glass transition temperature of the urethane resin is measured in accordance with JIS K 7121 as follows: Using a differential scanning calorimeter, the glass transition temperature is determined from the intersection point of the baseline and the tangent to the endothermic curve in the curve (DSC curve) obtained by heating 10 mg of urethane resin emulsion from -100°C to 160°C at a rate of 20°C / min.

[0040] When the aqueous resin composition contains a urethane resin emulsion, the urethane resin content in the aqueous resin composition is preferably 55% by mass or less, more preferably 53% by mass or less, and preferably 20% by mass or more, relative to the polyolefin resin content. By incorporating the urethane resin emulsion into the aqueous resin composition at the above-mentioned specific mass ratio relative to the polyolefin resin content, a coating layer with further improved dry laminate strength is easily obtained. The above mass ratio can be determined by {urethane resin content / polyolefin resin content} × 100 based on the total mass of the aqueous resin composition, or by {urethane resin content / polyolefin resin content} × 100 based on the mass of the solids in the aqueous resin composition.

[0041] Urethane resin emulsions can be obtained by reacting diisocyanates such as isophorone diisocyanate; polyols such as polycarbonate diols; diols such as diethylene glycol; and diol monocarboxylic acids such as dimethylolpropanoic acid, and then self-emulsifying with alkaline water while extending the chain with isophorone diamine. Urethane resin emulsions with a dispersed particle size (number average particle size) of 10 to 200 nm can be used.

[0042] Commercially available urethane resin emulsions may be used. Examples of commercially available urethane resin emulsions include "WBR-2120C" and "WBR-2122C" manufactured by Taisei Fine Chemical Co., Ltd., and "Takelac W-5030" manufactured by Mitsui Chemicals, Inc. One type of urethane resin emulsion may be used alone, or two or more types may be used in combination.

[0043] 〔wax〕 The aqueous resin composition contains wax. The wax is a component that constitutes the solid content in the aqueous resin composition. This wax includes at least one selected from the group consisting of polyethylene-based waxes and paraffin-based waxes.

[0044] By incorporating polyethylene-based wax and / or paraffin-based wax into an aqueous resin composition, it is possible to contribute to the formation of a coating layer with good blocking resistance, heat seal blocking resistance, and scratch resistance. If the aqueous resin composition does not contain polyethylene-based wax and paraffin-based wax, and instead contains other waxes (e.g., carnauba wax), the heat seal blocking resistance and scratch resistance of the coating layer will be inferior.

[0045] The wax content in the aqueous resin composition is 4 to 25% by mass, based on the mass of the solids in the aqueous resin composition. By keeping the wax content within the above range relative to the mass of the solids in the aqueous resin composition, it is possible to contribute to the formation of a coating layer that has good heat seal blocking resistance and scratch resistance, as well as transparency. If the wax content is less than 4% by mass relative to the mass of the solids in the aqueous resin composition, the heat seal blocking resistance and scratch resistance of the coating layer will be poor. On the other hand, if the wax content exceeds 25% by mass relative to the mass of the solids in the aqueous resin composition, the transparency of the coating layer will be poor. From the viewpoint of obtaining a coating layer with better substrate adhesion, hot melt adhesiveness, and transparency, the wax content relative to the mass of the solids in the aqueous resin composition is preferably 4 to 15% by mass, and from the viewpoint of obtaining a coating layer with better blocking resistance, it is preferably 5 to 25% by mass. The above wax content is the total content of waxes including polyethylene-based wax and paraffin-based wax, and preferably the total content of polyethylene-based wax and paraffin-based wax.

[0046] Furthermore, the wax content relative to the polyolefin resin content is polyolefin resin:wax = 1:0.043 to 1:0.300 by mass ratio. By setting the mass ratio of wax content to polyolefin resin content within the above range, a coating layer with better substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, scratch resistance, and transparency can be obtained. If the ratio of wax content to polyolefin resin content is less than 0.043, the blocking resistance, heat seal blocking resistance, and scratch resistance of the coating layer will be poor. On the other hand, if the ratio of wax content to polyolefin resin content is greater than 0.300, the substrate adhesion, heat seal blocking resistance, hot melt adhesive properties, scratch resistance, and transparency will be poor.

[0047] (Polyethylene-based wax) The aqueous resin composition preferably contains an aqueous dispersion of the polyethylene-based wax described above, that is, it preferably contains polyethylene-based wax dispersed in particulate form within the aqueous resin composition. In this case, the average particle size of the polyethylene-based wax is preferably 0.3 to 8 μm. When the average particle size of the polyethylene-based wax is within the above range, a coating layer with even better transparency, blocking resistance, and scratch resistance is more easily obtained. From the viewpoint of improving the transparency of the coating layer, the average particle size of the polyethylene-based wax is more preferably 0.3 to 3.5 μm, and from the viewpoint of improving the blocking resistance and scratch resistance of the coating layer, it is more preferably 0.7 to 8 μm.

[0048] In this disclosure, the average particle size of the wax is the particle size at the 50% cumulative frequency (median diameter: D50) calculated from the volume-based particle size distribution obtained by measuring the volume-based particle size distribution using the Coulter counter method, and is also called the volume-average particle size. The Coulter counter method is a method of electrically measuring the particle size and particle size distribution of wax particles dispersed in a liquid by passing them through pores and observing the change in electrical signals as the particles pass through.

[0049] The penetration degree of polyethylene-based wax is preferably 0.3 to 13, more preferably 1 to 12, and even more preferably 2 to 11 from the viewpoint of scratch resistance. In this disclosure, the penetration degree of the wax can be taken from a value measured at a sample temperature of 25°C by a method in accordance with JIS K 2235:2009.

[0050] Polyethylene wax may be manufactured according to conventional methods, or a commercially available product may be used. Examples of commercially available polyethylene waxes include the "Chemipearl" series (a polyethylene wax aqueous dispersion manufactured by Mitsui Chemicals, Inc.).

[0051] When a polyethylene-based wax is included in an aqueous resin composition, the polyethylene-based wax content in the aqueous resin composition is preferably 0.2 to 15% by mass, more preferably 0.4 to 10% by mass, and even more preferably 0.5 to 8% by mass, based on the mass of the solid content of the aqueous resin composition. By keeping the polyethylene-based wax content within the above range relative to the mass of the solid content of the aqueous resin composition, a coating layer with better heat seal blocking resistance and scratch resistance can be easily obtained. From this viewpoint, an aqueous resin composition containing polyethylene-based wax within the above range can be suitably used in the aqueous coating liquid that forms the coating layer in the laminates of the reverse-printed and front-printed configurations described later. In particular, by including polyethylene-based wax in the aqueous resin composition, the blocking resistance of the reverse-printed laminate described later can be further improved.

[0052] (Paraffin-based wax) The melting point of the paraffin-based wax is preferably 50 to 120°C. Using a paraffin-based wax having a melting point within this range makes it easier to obtain a coating layer with even better heat seal blocking resistance. From the viewpoint of improving heat seal blocking resistance, the melting point of the paraffin-based wax is more preferably 50 to 100°C. If the melting point of the paraffin-based wax is below 50°C, the heat seal blocking resistance may be slightly reduced, while if the melting point of the paraffin-based wax is above 120°C, the heat seal blocking resistance may be slightly reduced. However, the evaluation results showed that all the objectives of the present invention could be achieved. The melting point of the paraffin-based wax can be obtained by differential scanning calorimetry (DSC).

[0053] Paraffin waxes may be manufactured according to conventional methods or commercially available products may be used. Furthermore, similar to polyethylene waxes, aqueous dispersions of paraffin waxes may be used. Examples of commercially available paraffin waxes include the "AQUACER" series (manufactured by Big Chemie Japan Co., Ltd.).

[0054] When a paraffinic wax is included in an aqueous resin composition, the paraffinic wax content in the aqueous resin composition is preferably 1 to 24% by mass, and more preferably 3 to 22% by mass, based on the mass of the solid content of the aqueous resin composition. By keeping the paraffinic wax content within the above range relative to the mass of the solid content of the aqueous resin composition, a coating layer with better heat seal blocking resistance and scratch resistance can be easily obtained. From this viewpoint, an aqueous resin composition containing paraffinic wax within the above range can be suitably used as an aqueous coating liquid to form the coating layer in the laminate with the surface printing configuration described later. In particular, by including paraffinic wax in the aqueous resin composition, the heat seal blocking resistance and scratch resistance of the laminate with the surface printing configuration described later can be further improved.

[0055] On the other hand, from the viewpoint of easily increasing the dry laminate strength in the coating layer, the paraffinic wax content relative to the mass of solids in the aqueous resin composition is preferably 0 to 10% by mass, and more preferably 0 to 5% by mass. By setting the paraffinic wax content relative to the mass of solids in the aqueous resin composition to 0 to 10% by mass, it is possible to achieve the aforementioned dry laminate strength of 1.2 N / 15 mm or more. From this viewpoint, an aqueous resin composition in which the paraffinic wax content in the solids is limited to the above range can be suitably used as an aqueous coating liquid for forming the coating layer in a laminate having the structure of a laminate film described later.

[0056] [Membrane-forming aid] The aqueous resin composition preferably further contains a film-forming aid. The inclusion of a film-forming aid in the aqueous resin composition makes it easier to obtain a coating layer with even better transparency. The boiling point of the film-forming aid is preferably 70 to 260°C, more preferably 90 to 245°C, and even more preferably 130 to 240°C from the viewpoint of substrate adhesion, blocking resistance, and improved transparency. The film-forming aid with a boiling point of 70 to 260°C is a component that constitutes the volatile matter in the aqueous resin composition.

[0057] When an aqueous resin composition contains a film-forming aid, the content of the film-forming aid in the aqueous resin composition is preferably 0.05 to 2.5 in mass ratio to the wax content, and more preferably 0.1 to 2.5 from the viewpoint of transparency of the coating layer. Having the mass ratio of the film-forming aid content to the wax content within the above range improves the film adhesion and heat seal blocking resistance of the coating layer. The above mass ratio can be determined by dividing the content of the film-forming aid in the aqueous resin composition by the content of the wax.

[0058] Examples of film-forming aids with boiling points of 70-260°C include dimethyl glycol (DMG, also known as 1,2-dimethoxyethane; boiling point 85.2°C), dimethyl diglycol (DMDG, also known as diethylene glycol dimethyl ether; boiling point 162°C), dimethyl triglycol (DMTG, also known as triethylene glycol dimethyl ether; boiling point 216°C), methyl ethyl diglycol (MEDG, also known as diethylene glycol methyl ethyl ether; boiling point 176°C), diethyl diglycol (DEDG, also known as diethylene glycol diethyl ether; boiling point 188.9°C), and dibutyl diglycol. Examples include cellulose (DBDG, also known as diethylene glycol dibutyl ether; boiling point 255°C), dimethylpropylene diglycol (DMFDG, also known as dipropylene glycol dimethyl ether; boiling point 175°C), propylene glycol (PG; boiling point 188.2°C), dipropylene glycol n-butyl ether (DPnB; boiling point 230°C), propylene glycol monomethyl ether (PM; boiling point 121°C), isopropyl alcohol (IPA; boiling point 82.4°C), ethanol (boiling point 78°C), polyethylene glycol with a number average molecular weight of 200 (PEG200; boiling point 250°C), etc. One of these may be used alone, or two or more may be used in combination. When multiple types of film-forming aids are used in combination, the preferred boiling points mentioned above refer to the boiling points of each individual aid, and the mass ratio of the film-forming aid content to the wax content refers to the total content of multiple types of film-forming aids relative to the wax content.

[0059] Among the specific examples above, it is preferable that the film-forming aid includes at least one selected from the group consisting of diethyl diglycol, propylene glycol, dipropylene glycol n-butyl ether, propylene glycol monomethyl ether, isopropyl alcohol, ethanol, and polyethylene glycol. Furthermore, it is even more preferable that the film-forming aid includes at least one selected from the group consisting of diethyl diglycol, propylene glycol, and dipropylene glycol n-butyl ether.

[0060] [Surfactants] The aqueous resin composition may further contain a surfactant as needed. The surfactant is a component that constitutes the solid content in the aqueous resin composition. By including a surfactant in the aqueous resin composition, the surface tension of the aqueous resin composition and the aqueous coating solution can be adjusted, and the transparency of the coating layer can be improved. Examples of surfactants include organic surfactants, silicone surfactants, acetylene glycol surfactants, fluorine surfactants, and alkylene oxide surfactants. One of these may be used alone, or two or more may be used in combination. Among these, organic surfactants are preferred from the viewpoint of easily obtaining a coating layer with even better transparency. Commercially available surfactant products can be preferably used due to their availability.

[0061] As for the organic surfactant, at least one selected from the group consisting of anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and semipolar surfactants is preferred.

[0062] For more details, anionic surfactants include saturated or unsaturated fatty acid salts (e.g., sodium laurate, sodium stearate, sodium oleate, sodium linolenate, etc.), alkyl sulfates, alkylbenzenesulfonic acids (e.g., hexylbenzenesulfonic acid, toctylbenzenesulfonic acid, dodecylbenzenesulfonic acid, etc.) and their salts, polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkenyl ether sulfates, polyoxyethylene alkyl sulfates, alkyl sulfosuccinates, polyoxyalkylene alkyl sulfosuccinates, polyoxyalkylene alkylphenyl ether sulfates, alkanesulfonates, octyltrimethylammonium hydroxide, dodecyltrimethylammonium hydro Examples include oxides, alkyl sulfonates, polyoxyethylene alkylphenyl ether sulfates, polyoxyalkylene alkyl ether acetates, alkyl phosphates, polyoxyalkylene alkyl ether phosphates, acyl glutamates, α-acyl sulfonates, alkyl sulfonates, alkylallyl sulfonates, α-olefin sulfonates, alkylnaphthalene sulfonates, alkanesulfonates, alkyl or alkenyl sulfates, alkylamide sulfates, alkyl or alkenyl phosphates, alkylamide phosphates, alkylylalkyl taurine salts, N-acyl amino acid salts, sulfosuccinates, alkyl ether carboxylates, amide ether carboxylates, α-sulfo fatty acid ester salts, alanine derivatives, glycine derivatives, and arginine derivatives. Examples of salts include alkali metal salts such as sodium salts, alkaline earth metal salts such as magnesium salts, alkanolamine salts such as triethanolamine salts, and ammonium salts.

[0063] Examples of cationic surfactants include quaternary ammonium salts such as alkyltrimethylammonium chloride and benzalkonium chloride, and amine salts such as diethylaminoethylamide stearate.

[0064] Nonionic surfactants include polyoxyalkylene ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyalkylene fatty acid diesters, polyoxyalkylene resin acid esters, polyoxyalkylene (hydrogenated) castor oils, polyoxyalkylene alkylphenols, polyoxyalkylene alkylphenyl ethers, polyoxyalkylene phenylphenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylene alkyl esters, sorbitan fatty acid esters, and polyoxyalkylene sorbitan alkyl esters. Examples include polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, polyoxyalkylene glycerin fatty acid esters, polyglycerin alkyl ethers, polyglycerin fatty acid esters, sucrose fatty acid esters, fatty acid alkanolamides, alkyl glucosides, polyoxyalkylene fatty acid bisphenyl ethers, polypropylene glycol, diethylene glycol, fluorinated surfactants, polyoxyethylene / polyoxypropylene block polymers, and alkyl polyoxyethylene / polyoxypropylene block polymer ethers.

[0065] Examples of amphoteric surfactants include imidazoline type, amidebetaine type, alkylbetaine type, alkylamidebetaine type, alkylsulfobetaine type, amidesulfobetaine type, hydroxysulfobetaine type, carbobeautaine type, phosphobetaine type, aminocarboxylic acid type, and amideamino acid type amphoteric surfactants. Specifically, imidazoline type amphoteric surfactants such as 2-undecyl-N,N,N-(hydroxyethylcarboxymethyl)-2-imidazoline sodium and 2-cocoyl-2-imitazolinium hydroxide-1-carboxyethyloxy disodium salt; alkylbetaine type amphoteric surfactants such as lauryldimethylaminoacetic acid betaine and myristylbetaine; coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine, palm kernel oil fatty acid amidopropyl dimethylaminoacetic acid betaine, beef tallow fatty acid amidopropyl dimethylaminoacetic acid betaine, hydrogenated beef tallow fatty acid amidopropyl dimethylaminoacetic acid betaine, lauryl Amidobetaine-type amphoteric surfactants such as nitrate amidopropyl dimethylaminoacetic acid betaine, myristate amidopropyl dimethylaminoacetic acid betaine, palmitate amidopropyl dimethylaminoacetic acid betaine, stearic acid amidopropyl dimethylaminoacetic acid betaine, and oleic acid amidopropyl dimethylaminoacetic acid betaine; alkyl sulfobetaine-type amphoteric surfactants such as coconut oil fatty acid dimethyl sulfopropyl betaine; alkyl hydroxysulfobetaine-type amphoteric surfactants such as lauryl dimethylamino hydroxysulfobetaine; phosphobetaine-type amphoteric surfactants such as lauryl hydroxyphosphobetaine;N-Lauroyl-N'-Hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Oleoyl-N'-Hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Cocoyl-N'-Hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Lauroyl-N'-Hydroxyethyl-N'-carboxymethylethylenediamine potassium, N-Oleoyl-N'-Hydroxyethyl-N'-carboxymethylethylenediamine potassium, N-Lauroyl-N-Hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Oleoyl-N-Hydroxyethyl-N'-carboxymethylethylenediamine sodium, N-Cocoyl-N-Hydroxyethyl-N'-carboxy Examples of amide-amino acid type amphoteric surfactants include sodium methylethylenediamine, N-lauroyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-oleoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-cocoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine monosodium, N-lauroyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium, N-oleoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium, and N-cocoyl-N-hydroxyethyl-N',N'-dicarboxymethylethylenediamine disodium.

[0066] Examples of semi-polar surfactants include alkylamine oxide type surfactants, alkylamine oxides, alkylamideamine oxides, and alkylhydroxyamine oxides, with alkyldimethylamine oxides having 10 to 18 carbon atoms and alkoxyethyldihydroxyethylamine oxides having 8 to 18 carbon atoms being preferred.Specifically, dodecyldimethylamine oxide, dimethyloctylamine oxide, diethyldecylamine oxide, bis-(2-hydroxyethyl)dodecylamine oxide, dipropyltetradecylamine oxide, methylethylhexadecylamine oxide, dodecylamidopropyldimethylamine oxide, cetyldimethylamine oxide, stearyldimethylamine oxide, taludimethylamine oxide, dimethyl-2-hydroxyoctadecylamine oxide, lauryldimethylamine oxide, myristyldimethylamine oxide, stearyldimethylamine oxide, isostearyldimethylamine oxide, coconut fatty acid alkyldimethylamine oxide, caprylic acid amidopropyl dimethylamine oxide, capric acid amidopropyl dimethylamine oxide, lauric acid amidopropyl dimethylamine oxide, myristic acid amidopropyl dimethylamine oxide, palmitic acid amidopropyl dimethylamine oxide, ste Examples include phosphate amidopropyl dimethylamine oxide, isostearic acid amidopropyl dimethylamine oxide, oleic acid amidopropyl dimethylamine oxide, ricinoleic acid amidopropyl dimethylamine oxide, 12-hydroxystearic acid amidopropyl dimethylamine oxide, coconut fatty acid amidopropyl dimethylamine oxide, palm kernel oil fatty acid amidopropyl dimethylamine oxide, castor oil fatty acid amidopropyl dimethylamine oxide, lauric acid amidoethyl dimethylamine oxide, myristic acid amidoethyl dimethylamine oxide, coconut fatty acid amidoethyl dimethylamine oxide, lauric acid amidoethyl diethylamine oxide, myristic acid amidoethyl diethylamine oxide, coconut fatty acid amidoethyl diethylamine oxide, lauric acid amidoethyl dihydroxyethylamine oxide, myristic acid amidoethyl dihydroxyethylamine oxide, and coconut fatty acid amidoethyl dihydroxyethylamine oxide.

[0067] When the aqueous resin composition further contains a surfactant, it is preferable that the solid content of the surfactant be 0.01 to 6% by mass relative to the mass of the solid content of the aqueous resin composition, from the viewpoint of obtaining a coating layer with even better transparency.

[0068] [Hardening agents and crosslinking agents] The aqueous resin composition may optionally contain at least one selected from the group consisting of a curing agent and a crosslinking agent (hereinafter sometimes referred to as "curing agent and / or crosslinking agent"). Alternatively, the aqueous resin composition may be used without a curing agent and / or crosslinking agent, or together with a curing agent and / or crosslinking agent. For example, as a two-component type, an aqueous resin composition and a curing agent and / or crosslinking agent may be used, mixed to prepare an aqueous coating solution, and the resulting aqueous coating solution may be applied to a substrate such as a plastic film. By using a curing agent and / or crosslinking agent, it becomes easier to obtain an aqueous coating solution capable of forming a coating film with excellent coating film properties such as substrate adhesion, water resistance, and abrasion resistance.

[0069] (Hardening agent) Examples of curing agents include 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. Among these, isocyanate-based curing agents, carbodiimide-based curing agents, and aziridine-based curing agents are preferred from the viewpoint of two-component stability. These curing agents may be used individually or in combination of two or more. Among these, isocyanate-based curing agents are preferred from the viewpoint of excellent pot life, and aziridine-based curing agents are preferred from the viewpoint of easily obtaining a coating film with excellent moisture resistance and dry friction resistance.

[0070] Examples of isocyanate-based curing agents include polyvalent isocyanate compounds. These may be manufactured by known methods or be commercially available products. Specific commercially available isocyanate-based curing agents include: Mitsui Chemicals' "Takenate WD-720", "Takenate WD-725", "Takenate WD-726", "Takenate WD-730", "Takenate WD-220", "Takenate XWD-HS7", and "Takenate XWD-HS30"; Nippon Polyurethane Industry's "Aquanate 100", "Aquanate 110", "Aquanate 200", and "Aquanate 210"; Asahi Kasei's "Duranate WB40-100", "Duranate WB40-80D", "Duranate WT20-100", "Duranate WT30-100", "Duranate WL70-100", "Duranate WR80-70P", and "Duranate WE50-100"; and Bayer Material Science's "Bayhydur Examples include "3100", "Bayhydur 302", "Bayhydur 304", "Bayhydur 305", "Bayhydur XP2451 / 1", "Bayhydur XP2487 / 1", "Bayhydur XP2547", "Bayhydur XP2655", "Bayhydur XP2700"; BASF's product names "Basonat HW100", "Basonat HA100", "Basonat HW1180PC"; and Dainichi Seika Kogyo's product name "Hydric FC Hardener". Isocyanate hardeners may be used individually or in combination of two or more types.

[0071] Specific examples of blocked isocyanate curing agents include blocks of isocyanate curing agents (e.g., alcohol compounds, phenolic compounds, oxime compounds, lactam compounds, pyrazole compounds, and active methylene compounds). These blocked isocyanate curing agents may be used individually or in combination of two or more.

[0072] Carbodiimide-based curing agents are compounds containing two or more carbodiimide groups in one molecule. Specific examples of carbodiimide-based curing agents include poly(4,4'-diphenylmethanecarbodiimide), poly(dicyclohexylmethanecarbodiimide), and poly(diisopropylcarbodiimide). Commercially available carbodiimide-based curing agents include the "Carbodilight" series from Nisshinbo Chemical Co., Ltd. and "AB Hardener" from Dainichi Seika Kogyo Co., Ltd. These carbodiimide-based curing agents may be used individually or in combination of two or more.

[0073] Oxazoline-based curing agents are compounds containing two or more oxazoline groups in one molecule. Specific examples of oxazoline-based curing agents include polyhydric oxazolines such as 2,2'-bis-(2-oxazoline), 2,2'-methylene-bis-(2-oxazoline), and 2,2'-(1,4-phenylene)-bis(2-oxazoline), as well as polymers or copolymers having oxazoline group-containing monomer units such as 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. The oxazoline group-containing monomers may be used individually or in combination of two or more types. Furthermore, copolymers of an oxazoline group-containing monomer with another monomer copolymerizable with this monomer are also used. Examples of commercially available oxazoline-based curing agents include the "Epocross" series manufactured by Nippon Shokubai Co., Ltd. These oxazoline-based curing agents may be used individually or in combination of two or more.

[0074] Epoxy curing agents are compounds containing two or more epoxy groups in one molecule. Specific examples of epoxy curing agents include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, triglycidylaminophenol, biphenyl diglycidyl ether, triglycidyl isocyanurate, polyglycidyl (meth)acrylate, and copolymers of glycidyl (meth)acrylate with vinyl monomers copolymerizable thereto. Commercially available epoxy curing agents include the "jER" series from Mitsubishi Chemical Corporation and the "Denacol EX" series from Nagase ChemteX Corporation. These epoxy curing agents may be used individually or in combination of two or more.

[0075] Aziridine-based curing agents are compounds containing two or more aziridine groups in one molecule. Specific examples of aziridine-based curing agents include 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane. Commercially available aziridine-based curing agents include the "Chemitite" series from Nippon Shokubai Co., Ltd. and "Hydric RA Hardener" from Dainichi Seika Kogyo Co., Ltd. These aziridine-based curing agents may be used individually or in combination of two or more.

[0076] When using an aqueous resin composition and a curing agent in combination, it is preferable to mix the aqueous resin composition and the curing agent so that the solid content of the curing agent is 0.1 to 10 parts by mass per 100 parts by mass of the total mass of the aqueous resin composition. More preferably, the amount of curing agent used is 0.3 to 7 parts by mass, and even more preferably 0.5 to 7 parts by mass. By keeping the amount of curing agent used within the above range, it is easier to obtain an aqueous coating liquid with excellent fluidity during coating and a long pot life after mixing with the curing agent.

[0077] (Crosslinking agent) Examples of crosslinking agents include isocyanate-based crosslinking agents, blocked isocyanate-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, silane coupling agents, and titanium coupling agents. Among these, isocyanate-based crosslinking agents are preferred from the viewpoint of easily obtaining a coating layer with good abrasion resistance.

[0078] Specific examples of isocyanate crosslinking agents include polyvalent isocyanate compounds. Specific examples of blocked isocyanate crosslinking agents include blocked isocyanate crosslinking agents (e.g., alcohol compounds, phenolic compounds, oxime compounds, lactam compounds, pyrazole compounds, and active methylene compounds). Specific examples of carbodiimide crosslinking agents include the "Carbodilite" series manufactured by Nisshinbo Chemical Co., Ltd. Specific examples of oxazoline crosslinking agents include the "Epocross" series manufactured by Nippon Shokubai Co., Ltd. Specific examples of epoxy crosslinking agents include the "jER" series manufactured by Mitsubishi Chemical Corporation. Specific examples of aziridine crosslinking agents include the "Chemitite" series manufactured by Nippon Shokubai Co., Ltd. Specific examples of silane coupling agents include 3-glycidoxypropyltrimethoxysilane. Specific examples of titanium coupling agents include titanium di-2-ethylhexoxybis(2-ethyl-3-hydroxyhexoxide). These crosslinking agents may be used individually or in combination of two or more.

[0079] When using an aqueous resin composition and a crosslinking agent in combination, it is preferable to mix the aqueous resin composition and the crosslinking agent so that the solid content of the crosslinking agent is 0.1 to 10 parts by mass per 100 parts by mass of the total mass of the aqueous resin composition. The amount of crosslinking agent used is more preferably 0.3 to 7 parts by mass, and even more preferably 0.5 to 7 parts by mass.

[0080] [Aqueous medium] Since the aqueous resin composition contains the aforementioned polyolefin resin emulsion, it contains at least an aqueous medium including water. The aqueous medium may be only the aforementioned polyolefin resin emulsion, and, if necessary, the aqueous medium contained in the resin emulsion, such as acrylic resin emulsion and urethane resin emulsion. Furthermore, if an aqueous dispersion of wax is used as the aforementioned wax, the aqueous resin composition may contain the aqueous medium in the aqueous dispersion of wax in addition to the aqueous medium in the resin emulsion. Moreover, the aqueous resin composition may contain an aqueous medium such as water used to adjust viscosity and solid content, separate from the aqueous medium in the resin emulsion or aqueous dispersion of wax.

[0081] As the aqueous medium, water or a mixed solvent of water and an organic solvent can be used. The organic solvent is not particularly limited as long as it is soluble in water, and examples include alcohol-based solvents such as methanol, ethanol, propanol, n-butanol, and i-butanol; ketone-based solvents such as acetone; and glycol ether-based solvents such as propylene glycol monomethyl ether. 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.

[0082] [Other ingredients] (Colorants) The aqueous resin composition may contain at least one colorant selected from the group consisting of pigments and dyes. By incorporating a colorant into the aqueous resin composition, an aqueous ink resin composition can be obtained, and an aqueous ink can be prepared using that aqueous ink resin composition.

[0083] Both organic and inorganic pigments can be used as pigments. Examples of organic pigments include azo pigments such as monoazo and condensed azo; surene pigments such as anthraquinone, perinone, perylene, and thioindigo; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; quinacridone pigments; dioxazine pigments; isoindolinone pigments; pyrrolopyrrole pigments; aniline black; and organic fluorescent pigments. Examples of inorganic pigments include natural products such as clay, barite, mica, and talc; ferrocyanides such as Prussian blue; sulfides such as zinc sulfide; sulfates such as barium sulfate; oxides such as chromium oxide, zinc oxide, titanium dioxide, and iron oxide; hydroxides such as aluminum hydroxide; silicates such as calcium silicate and ultramarine; carbonates such as calcium carbonate and magnesium carbonate; carbon such as carbon black and graphite; metal powders such as aluminum powder, bronze powder, and zinc powder; and calcined pigments. These pigments may be used individually or in combination of two or more.

[0084] When an aqueous resin composition is used as a resin composition for aqueous inks containing colorants such as pigments, the content of the colorant relative to the total mass of the aqueous resin composition (resin composition for aqueous inks) is preferably 1 to 60% by mass. When an organic pigment is used as a colorant, the content of the organic pigment is preferably 1 to 35% by mass relative to the total mass of the aqueous resin composition (resin composition for aqueous inks). When an inorganic pigment such as titanium dioxide or barium sulfate is used as a colorant, the content of the inorganic pigment is preferably 10 to 60% by mass relative to the total mass of the aqueous resin composition (resin composition for aqueous inks).

[0085] (Other additives) The aqueous resin composition may further contain other additives as needed. Examples of other additives include plasticizers, anti-blocking agents, dispersants, anti-settling agents, leveling agents, defoamers, matting agents, pH adjusters, antioxidants, UV absorbers, light stabilizers, preservatives, fungicides, rust inhibitors, flame retardants, color developers, chelating agents, and coupling agents. These additives may be used individually or in combination of two or more.

[0086] The amount of additives is not particularly limited, but for example, it is preferably 0 to 20% by mass, more preferably 0 to 15% by mass, and even more preferably 0 to 10% by mass, relative to the total mass of the aqueous resin composition.

[0087] [Total solids] The total solids content (total mass of solids) of the aqueous resin composition is preferably 3 to 60% by mass, more preferably 5 to 50% by mass, and even more preferably 5 to 40% by mass, from the viewpoint of improving storage stability. By setting the total solids content of the aqueous resin composition within the above range, storage stability and ink fluidity can be improved. If the total solids content of the aqueous resin composition is less than 3% by mass, the drying performance of the coating film during coating tends to be insufficient. On the other hand, if the total solids content of the aqueous resin composition is more than 60% by mass, the fluidity of the aqueous coating liquid tends to be insufficient, but the evaluation results showed that all the objectives of the present invention could be achieved.

[0088] [Component content in aqueous resin composition] From the viewpoint of easily obtaining the desired coating layer, the content of polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g in the aqueous resin composition is preferably 2 to 57% by mass, more preferably 3 to 46% by mass, and even more preferably 3 to 38% by mass from the viewpoint of substrate adhesion. Furthermore, the content of wax (total of polyethylene-based wax and paraffin-based wax) in the aqueous resin composition is preferably 0.2 to 15% by mass, more preferably 0.4 to 12% by mass, and even more preferably 0.5 to 10% by mass from the viewpoint of heat seal blocking resistance, based on the total mass of the aqueous resin composition. The content of film-forming aid in the aqueous resin composition is preferably 0.2 to 15% by mass, more preferably 0.4 to 12% by mass, and even more preferably 0.5 to 10% by mass from the viewpoint of transparency, based on the total mass of the aqueous resin composition.

[0089] (Method for manufacturing aqueous resin compositions) The aqueous resin composition can be prepared by mixing the aforementioned polyolefin resin emulsion and wax, along with other components used as needed, according to conventional methods, so that each component is present in a desired amount. The aforementioned polyolefin resin emulsion and wax may each be in liquid form, or the wax may be in solid form. In other words, the aqueous resin composition may be a liquid formed by pre-mixing liquid and solid components, or it may be an aqueous resin composition obtained by mixing all liquid components to form a liquid. Other components that may be used as needed in addition to the polyolefin resin emulsion and wax include the aforementioned acrylic resin emulsion, urethane resin emulsion, film-forming aids, surfactants, curing agents, crosslinking agents, aqueous media, colorants, and other additives.

[0090] Furthermore, a solid resin composition can be provided which is the aqueous resin composition described above after drying. This solid resin composition contains the polyolefin resin described above and the wax described above, with the polyolefin resin content being 60 to 95% by mass and the wax content being 4 to 25% by mass. The wax content relative to the polyolefin resin content is, by mass ratio, polyolefin resin:wax = 1:0.043 to 1:0.300.

[0091] By using the aqueous resin composition described in detail above, an aqueous coating solution capable of forming a transparent coating layer with good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance can be easily prepared. As such an aqueous coating solution, aqueous varnish, aqueous medium, aqueous primer, and aqueous reducer, as well as aqueous inks containing colorants, can be obtained. The aqueous medium is used as a hue adjusting liquid and is mixed with aqueous ink. In addition, aqueous varnish is used to form a varnish layer such as an overcoat layer, and aqueous primer is used to form a primer layer applied to the substrate before printing ink, etc.

[0092] <Water-based coating liquid> An aqueous coating solution according to one embodiment of the present invention (which may be simply referred to as "aqueous coating solution" in this disclosure) contains the aforementioned aqueous resin composition. Therefore, the aqueous coating solution contains at least a resin emulsion containing the aforementioned polyolefin resin emulsion, and a polyethylene wax and / or paraffin wax. Furthermore, the aqueous coating solution forms a coating film with a haze value of 15% or less.

[0093] Depending on the type, application, and coating method of the aqueous coating solution, various aqueous coating solutions can be prepared by adding a liquid medium (e.g., an aqueous medium) to the aforementioned aqueous resin composition to adjust it to an appropriate viscosity, or by adding an appropriate additive (e.g., the other additives mentioned above) as needed. Furthermore, depending on the type, application, and coating method of the aqueous coating solution, various aqueous coating solutions can also be prepared by mixing the aforementioned polyolefin resin emulsion and wax, along with other components used as needed, according to conventional methods so that each component is present in the desired amount. Other components that may be used as needed in addition to the polyolefin resin emulsion and wax include the aforementioned acrylic resin emulsion, urethane resin emulsion, film-forming aids, surfactants, curing agents, crosslinking agents, aqueous media, colorants, and other additives. Suitable aqueous coating solutions include those for flexographic printing or gravure printing, and that contain aqueous varnish, aqueous medium, aqueous primer, or aqueous reducer, or aqueous ink containing a colorant.

[0094] Water-based varnishes, water-based mediums, water-based primers, and water-based reducers can be prepared without substantially including colorants in the water-based resin composition. Therefore, when the water-based coating solution is a water-based varnish, water-based medium, water-based primer, or water-based reducer, the content of each component relative to the mass of solids in the water-based coating solution can be equivalent to the content of each component relative to the mass of solids in the aforementioned water-based resin composition. For example, the content of polyolefin resin can be 60 to 95% by mass and the content of wax can be 4 to 25% by mass relative to the mass of solids in a water-based coating solution that is a water-based varnish, water-based medium, water-based primer, or water-based reducer.

[0095] On the other hand, aqueous inks can be easily prepared using an aqueous ink resin composition obtained by incorporating a colorant such as a pigment into an aqueous resin composition. Therefore, when an aqueous coating solution is an aqueous ink, the content of each component relative to the mass of the solid content of the aqueous ink excluding the colorant can be equivalent to the content of each component relative to the mass of the solid content of the aforementioned aqueous resin composition. For example, the content of polyolefin resin can be 60 to 95% by mass and the content of wax can be 4 to 25% by mass relative to the mass of the solid content (excluding the colorant) of the aqueous ink.

[0096] Furthermore, the wax content relative to the polyolefin resin content in the aqueous coating liquid, such as the aforementioned aqueous varnish, aqueous medium, aqueous primer, aqueous reducer, or aqueous ink, can be set to a mass ratio of polyolefin resin:wax = 1:0.043 to 1:0.300.

[0097] The aqueous coating liquid of this embodiment can form a coating layer that has good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, as well as transparency. Even with the aqueous coating liquid, by adopting the preferred configuration described above for the aqueous resin composition, it becomes easier to obtain a coating layer with the above characteristics. Furthermore, an aqueous coating liquid in which the paraffin wax content relative to the solid content of the aqueous coating liquid (however, if the aqueous coating liquid is an aqueous ink, excluding the colorant) is 0 to 10% by mass (more preferably 0 to 5% by mass) can form a coating layer with even higher dry laminate strength in addition to the above characteristics. Furthermore, an aqueous coating liquid containing a urethane resin emulsion in which the urethane resin content is 55% by mass or less relative to the polyolefin resin content can also form a coating film with high dry laminate strength in addition to the above characteristics.

[0098] As described above, the aqueous coating solution of this embodiment is for flexographic printing or gravure printing and can be suitably used as an aqueous ink, aqueous varnish, aqueous medium, aqueous primer, or aqueous reducer. That is, the aqueous coating solution is an aqueous coating solution for flexographic printing or gravure printing and can be suitably used not only as an aqueous ink containing colorants such as pigments, but also as an aqueous varnish, aqueous medium, aqueous primer, and aqueous reducer that substantially do not contain colorants. Furthermore, coated products such as printed materials can be manufactured by using a combination of the aqueous ink of this embodiment, which contains colorants, and at least one of the aqueous varnish, aqueous medium, aqueous primer, and aqueous reducer of this embodiment, which do not contain colorants. In particular, it is preferable from the viewpoint of compatibility to use a combination of the aqueous ink of this embodiment, which has the same composition of components other than colorants, and at least one of the aqueous varnish, aqueous medium, aqueous primer, and aqueous reducer of this embodiment.

[0099] <Laminate> A laminate according to one embodiment of the present invention (which may be simply referred to as "laminated" in this disclosure) comprises a substrate and a coating layer disposed on the substrate, wherein the coating layer includes a coating layer formed with the above-described aqueous coating liquid. Preferably, the coating layer in the laminate includes a coating layer formed with the above-described aqueous coating liquid for flexographic printing or gravure printing, that is, a coating layer formed by flexographic printing or gravure printing with the above-described aqueous coating liquid. The arrangement of the coating layer on the substrate includes a configuration in which a coating layer formed by coating the surface of the substrate with the above-described aqueous coating liquid is provided, as well as a configuration in which a coating layer formed with the above-described aqueous coating liquid is provided on the surface of the substrate via another layer. By using the above-described aqueous coating liquid for the coating layer, a laminate can be obtained in which a coating layer is formed that has good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesiveness, and scratch resistance, as well as transparency.

[0100] For example, by printing an aqueous ink as an aqueous coating liquid onto the surface of a substrate using common printing methods such as gravure printing and flexographic printing, a printed layer with the desired design or information can be formed as a coating layer. This makes it possible to obtain a printed material as a laminate comprising a substrate and a printed layer having the above-mentioned characteristics provided on the substrate.

[0101] The laminate will be described in more detail below with reference to the drawings. Figures 1 and 2 are schematic cross-sectional views showing an example of the arrangement of layers constituting a laminate according to one embodiment of the present invention. Therefore, the laminate shown in Figures 1 and 2 may have layers not shown between the layers shown in the figures. Note that the dimensional ratios in Figures 1 and 2 differ from those of the actual dimensions for the sake of explanation. When the laminate of Figures 1 and 2 is used as a label or packaging material, the side that is visible is called the front surface, and the opposite side is called the back surface.

[0102] The laminate 10 shown in Figure 1 comprises a base material 11 and a coating layer 12 formed of the aqueous coating liquid of the aforementioned embodiment of the present invention (hereinafter sometimes referred to as "this aqueous coating liquid"), which is disposed on the base material 11. The laminate 20 shown in Figure 2 comprises a first base material 21 and a coating layer 22 formed of the aqueous coating liquid of the aforementioned embodiment of the present invention (this aqueous coating liquid), which is disposed on the first base material 21 and a second base material 23 disposed on the coating layer 22.

[0103] The coating layer 12 in the laminate 10 and the coating layer 22 in the laminate 20 may be a single-layer structure or a multi-layer structure formed by applying multiple layers of this aqueous coating liquid. The thickness of the coating layers 12 and 22 (or the total thickness in the case of a multi-layer structure formed by applying multiple layers) is preferably, for example, 0.2 to 15 μm, more preferably 0.3 to 10 μm, even more preferably 0.5 to 5 μm, and particularly preferably 1 to 2 μm.

[0104] The laminates 10 and 20 may further comprise layers other than the substrates 11, 21, and 23, and the coating layers 12 and 22. Examples of these other layers include other coating layers such as pattern layers formed using printing inks, and vapor-deposited layers formed by depositing metals or metal oxides such as aluminum or silica. For example, in the laminates 10 and 20, other coating layers or vapor-deposited layers may be provided on the surface of the substrates 11 and 21 on the side where the coating layers 12 and 22 are provided, or on the surface opposite to that side. In addition, in the laminate 20, an adhesive layer (not shown) may be provided between the coating layer 22 and the second substrate 23, formed by applying an adhesive to the surface of the coating layer 22 or the surface of the second substrate 23.

[0105] The laminate 10 may be configured such that the substrate 11 is the outermost layer and the coating layer 12 formed with the aqueous coating solution is visible from the side of the substrate 11 (reverse printing configuration), or it may be configured such that the coating layer 12 formed with the aqueous coating solution is the outermost layer of the laminate 10 (front printing configuration). Either configuration can be used suitably.

[0106] (Reverse printing layout) Specific examples of the above-mentioned reverse-printed configuration include: a laminate 10 comprising a base material 11 and a first coating layer provided on the back surface of the base material 11; a laminate 10 further comprising a second coating layer provided on the back surface of the first coating layer; a laminate 10 further comprising a primer layer formed between the base material 11 and the first coating layer by applying a primer to the back surface of the base material 11 before applying the first coating layer; and a laminate 10 further comprising an outermost varnish layer formed by applying varnish to the back surface of the second coating layer. In these specific examples of reverse-printed configurations, at least one of the first coating layer, second coating layer, primer layer, and varnish layer can be a coating layer 12 formed with this aqueous coating solution. From the viewpoint of making the properties of the coating layer 12 formed with this aqueous coating solution more meaningful, in each specific example of the above reverse printing configuration, it is preferable that the layer provided on the back surface of the substrate 11 (the first coating layer or primer layer) and the outermost varnish layer be the coating layer 12 formed with this aqueous coating solution.

[0107] In a preferred example of the laminate 10 with the reverse-printed configuration described above, the first coating layer can be a color printed layer printed using a color ink containing a coloring material such as a pigment, for example, to impart design or functionality. In this case, the substrate 11 in the laminate 10 is preferably a plastic film or the like that is transparent enough to allow the first coating layer, which is the color printed layer, to be visible. Furthermore, in a preferred example of the laminate 10 with the reverse-printed configuration described above, the second coating layer is preferably a white printed layer formed by printing white ink on the back surface of the first coating layer, for purposes such as protecting the first coating layer, which is the color printed layer, providing opacity, and further improving the sharpness of images on the color printed layer. The aqueous coating solution can be used for at least one of the color ink, white ink, primer, and varnish used in the laminate 10 with the reverse-printed configuration described above, and known materials may be used for the others. For example, the white ink used may be a known white ink, or it may be a water-based coating solution (water-based ink) containing a colorant such as a white pigment (e.g., titanium dioxide).

[0108] (Cover layout) Suitable examples of the above surface printing configurations include: a laminate 10 comprising a base material 11 and a second coating layer provided on the surface of the base material 11; a laminate 10 further comprising a first coating layer provided on the surface of the second coating layer; a laminate 10 further comprising a primer layer formed between the base material 11 and the second coating layer by applying a primer to the surface of the base material 11 before applying the second coating layer; and a laminate 10 further comprising an outermost varnish layer formed by applying varnish to the surface of the first coating layer. In these specific examples of surface printing configurations, at least one of the first coating layer, second coating layer, primer layer, and varnish layer can be a coating layer 12 formed with this aqueous coating solution. From the viewpoint of making the properties of the coating layer 12 formed with this aqueous coating solution more meaningful, it is preferable that in each specific example of the above-described surface printing configuration, the primer layer, the first coating layer, and the varnish layer be the coating layer 12 formed with this aqueous coating solution.

[0109] In a specific example of the laminate 10 with the above-described surface printing configuration, the first coating layer can be a color printing layer printed using a color ink containing a coloring material such as a pigment, for example, to impart design or functionality. Furthermore, in a specific example of the laminate 10 with the above-described surface printing configuration, the second coating layer provided on the surface of the substrate 11 is preferably a white printing layer formed by printing white ink on the surface of the substrate 11, for example, to impart opacity to the first coating layer, which is the color printing layer, or to further improve the sharpness of the image on the color printing layer. The aqueous coating solution can be used for at least one of the color ink, white ink, primer, and varnish used in the laminate 10 with the above-described surface printing configuration, and known materials may be used for the others. For example, the white ink may be a known white ink, or the aqueous coating solution (aqueous ink) containing a coloring material such as a white pigment (e.g., titanium dioxide) may be used.

[0110] In each of the above-described specific examples of the reverse-printed and front-printed configurations, the first coating layer may be provided on the entire surface of the layer to which the first coating layer is provided (for example, the substrate 11 or primer layer in the reverse-printed configuration, the second coating layer in the front-printed configuration, etc.), or on only a part of it. When the first coating layer is provided on only a part of the surface of the layer to which the first coating layer is provided, it is preferable that other coating layers, such as the varnish layer described above, are provided in the area of ​​that layer where the first coating layer is not provided.

[0111] Each coated layer is obtained by applying a coating liquid (the above-mentioned aqueous coating liquid, as well as known inks, primers, and varnishes, etc.) and drying it. The same coating liquid may be applied again (overcoated). The method of applying the coating liquid is not particularly limited, and known coating methods such as gravure printing, flexographic printing, brush coating, gravure coater method, knife coater method, reverse 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. Multiple coating methods may be employed in a single laminate depending on the type of coating liquid. Among the above-mentioned coating methods, gravure printing and flexographic printing are preferred due to their high quality and productivity.

[0112] The laminate 20 shown in Figure 2 comprises a first substrate 21, a second substrate 23, and a coating layer 22 formed with the aqueous coating solution provided between them, and is a laminate 20 having the structure of a so-called laminate film. As described above, the laminate 20 may also include other layers besides the first substrate 21, the second substrate 23, and the coating layer 22. Examples of other layers include a pattern layer made of printing ink, an adhesive layer made of adhesive, and a vapor-deposited layer made by vapor-depositing a metal or metal oxide such as aluminum or silica.

[0113] The laminate 20 is preferably a laminate comprising a first substrate 21, a coating layer 22 formed of the aqueous coating liquid placed on the first substrate 21, an adhesive layer (not shown) formed of an adhesive placed on the coating layer 22, and a second substrate 23 provided on the adhesive layer.

[0114] When the laminate 20 is to be a laminate film with the above-described configuration, it can be easily manufactured, for example, by the following method. First, the aqueous coating liquid is applied to the first substrate 21 by the above-described coating method to form a coating layer 22. Next, an adhesive layer is formed by applying an adhesive to the coating layer 22 by the above-described coating method, and a laminate film can be manufactured by laminating the second substrate 23 onto the adhesive layer. Other layers may be provided between the first substrate 21 and the coating layer 22, between the coating layer 22 and the adhesive layer, and between the adhesive layer and the second substrate 23.

[0115] The method for laminating the second substrate 23 is not particularly limited, and suitable examples include the extrusion lamination method, the dry lamination method, and the non-solvent lamination method. In the extrusion lamination method, an anchor coating agent is applied to the above-mentioned coating layer 22 instead of the adhesive (adhesive layer), or without application, molten polyethylene resin, molten polypropylene resin, etc., are extruded and laminated. In the dry lamination method, an adhesive diluted to an appropriate viscosity with an organic solvent is applied to the above-mentioned coating layer 22, dried, and then a sealant film (resin layer) as the second substrate 23 is heat-pressed and laminated. In the non-solvent lamination method, a solvent-free adhesive is applied to the above-mentioned coating layer 22, and then a sealant film as the second substrate 23 is heat-pressed and laminated.

[0116] (base material) Examples of materials for the base material 11 that can be used in the laminate 10, and the first base material 21 and second base material 23 that can be used in the laminate 20 include polyethylenes such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE); polypropylene; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polylactic acid; polyamide (NY); cellulose such as cellophane; polystyrene (PS); ethylene-vinyl acetate copolymer resin; ethylene-vinyl alcohol copolymer resin; polycarbonate; polyimide; polyvinyl chloride; etc. The materials of the base materials 11, 21, and 23 can be appropriately selected according to the application of the laminates 10 and 20.

[0117] Among the above, polyethylenes and polyolefin films such as polypropylene are preferred as base materials 11, 21, and 23. In this case, it is preferable to use materials that have been corona-treated. Furthermore, the base materials 11, 21, and 23 used in the manufacture of the laminates 10 and 20 may all be made from recycled materials that have been recovered after being used as printed materials. Furthermore, the base materials 11, 21, and 23 used in the manufacture of the laminates 10 and 20 may be stretched or unstretched. In addition, if necessary, base materials 11, 21, and 23 may be coated with metals or metal oxides such as silica, alumina, or aluminum, or their coated surfaces may be coated with a paint such as polyvinyl alcohol.

[0118] The shapes of the substrates 11, 21, and 23 are not particularly limited, and substrates of a shape suitable for the purpose can be used. Specific examples of substrate shapes include film-like and sheet-like forms. Film-like and sheet-like substrates 11, 21, and 23 are suitably used for labels on which various information such as product name, contents, and manufacturer is printed. Furthermore, specific examples of substrate shapes include various containers and packaging materials such as cups, plates, bowls, and bottles, as well as lids such as caps. By having a coating layer applied to the surface of the substrate using the aqueous coating solution of this embodiment by general printing methods such as gravure printing and flexographic printing, a laminate can be obtained that has the desired design and information, good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance, and is transparent.

[0119] (Labels, packaging materials) The laminate of this embodiment is useful, for example, as a label or packaging material. Specifically, the laminate is suitable as a container for food products, soft drinks, cosmetics, seasonings, pharmaceuticals, and hygiene products; a label to be affixed to these containers; a resin bag (packaging material) for food products such as bread, rice balls, and prepared foods; and so on.

[0120] The labels are used for a variety of products, including beverages, condiments, prepared foods, and bento boxes, as well as cosmetics and daily necessities. They are particularly suitable as labels for items whose packaging is a plastic bottle, such as labels for bottled food and beverages. Examples of bottled food and beverages include beverages, liquid condiments (dressings, noodle soup bases, soy sauce, liquid miso, etc.), and edible oils. The labels can take the form of a wrap-around label or a shrink-wrap label. The packaging materials are used for a variety of products, including confectionery, pastries, vegetables, prepared foods, daily necessities such as cosmetics, pharmaceuticals, and hygiene products.

[0121] As mentioned above, one embodiment of the present invention can have the following configuration. [1] An aqueous resin composition used in an aqueous coating solution having a haze value of 15% or less of the coating film, It contains a resin emulsion and wax, The resin emulsion comprises a polyolefin resin emulsion containing a polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g. The wax comprises at least one selected from the group consisting of polyethylene-based waxes and paraffin-based waxes. The aqueous resin composition has a polyolefin resin content of 60-95% by mass and a wax content of 4-25% by mass, relative to the mass of solids. An aqueous resin composition in which the content of the wax relative to the content of the polyolefin resin is, by mass ratio, the polyolefin resin:wax = 1:0.043 to 1:0.300. [2] The aqueous resin composition according to [1] above, wherein the polyolefin resin comprises at least one selected from the group consisting of polypropylene resin, polyethylene resin, and polypropylene-polyethylene copolymer. [3] Contains the polyethylene wax aqueous dispersion, The aqueous resin composition according to [1] or [2] above, wherein the average particle size of the polyethylene wax is 0.3 to 8 μm. [4] The aqueous resin composition according to any one of [1] to [3] above, wherein the melting point of the paraffin wax is 50 to 120°C. [5] The aqueous resin composition according to any one of [1] to [4] above, wherein the content of the paraffin wax relative to the mass of the solids of the aqueous resin composition is 0 to 10% by mass. [6] The aqueous resin composition according to any one of the above [1] to [5], further comprising a film-forming aid having a boiling point of 70 to 260°C. [7] The aqueous resin composition according to [6], wherein the content of the film-forming aid in the aqueous resin composition is 0.05 to 2.5 in mass ratio to the content of the wax. [8] The aqueous resin composition according to [6] or [7] above, wherein the film-forming aid comprises at least one selected from the group consisting of diethyldiglycol, propylene glycol, dipropylene glycol n-butyl ether, propylene glycol monomethyl ether, isopropyl alcohol, ethanol, and polyethylene glycol. [9] Furthermore, it contains a surfactant, The aqueous resin composition according to any one of the above [1] to [8], wherein the content of the surfactant is 0.01 to 6% by mass with respect to the mass of the solid content of the aqueous resin composition.

[10] The resin emulsion further comprises an acrylic resin emulsion containing an acrylic resin having a glass transition temperature of 75°C or higher. The aqueous resin composition according to any one of the above [1] to [9], wherein the content of the acrylic resin in the aqueous resin composition is 35% by mass or less relative to the content of the polyolefin resin.

[11] The resin emulsion further comprises a urethane resin emulsion containing a urethane resin, The aqueous resin composition according to any one of the above [1] to

[10] , wherein the content of the urethane resin in the aqueous resin composition is 55% by mass or less relative to the content of the polyolefin resin.

[12] The aqueous resin composition according to any one of the above [1] to

[11] , further comprising at least one selected from the group consisting of a curing agent and a crosslinking agent.

[13] An aqueous resin composition according to any one of [1] to

[12] above, which has excellent scratch resistance, wherein when a coating film obtained by applying the aqueous coating liquid containing the aqueous resin composition is rubbed in the width direction with a hard object, the ratio of the area of ​​the detached coating film to the test area of ​​the coating film after 10 back-and-forth strokes is less than 20%.

[14] A solid resin composition obtained by drying the aqueous resin composition described in any of [1] to

[13] above.

[15] A water-based coating liquid having a haze value of 15% or less of the coating film, A water-based coating solution containing any of the water-based resin products described in [1] to

[13] above.

[16] For flexographic printing or gravure printing, The aqueous coating liquid described in

[15] above, which is an aqueous varnish, aqueous medium, aqueous primer, or aqueous reducer, or an aqueous ink containing a colorant.

[17] comprising a substrate and a coating layer disposed on the substrate, A laminate comprising a coating layer formed with the aqueous coating solution described in

[16] above.

[18] The laminate described in

[17] above, which is a label or packaging material. [Examples]

[0122] One embodiment of the present invention will be described in detail below based on examples, but one embodiment of the present invention is not limited to these examples.

[0123] <Preparation of various raw materials> (Polyolefin resin emulsion) Commercially available polyolefin resin emulsions P-1 to P-10, as shown in Table 1 below, were prepared.

[0124] TIFF2026121158000001.tif80170

[0125] (Other resin emulsions) We prepared commercially available acrylic resin emulsions A-1 to 4 and urethane resin emulsions U-1 to 2, as shown in Table 2 below.

[0126] TIFF2026121158000002.tif81170

[0127] (Water dispersion of wax) We prepared commercially available aqueous dispersions of wax, W-1 to W-8, as shown in Table 3 below.

[0128] TIFF2026121158000003.tif69170

[0129] The following compounds were used as film-forming aids. • Diethyldiglycol (hereinafter also referred to as DEDG; boiling point 188.9°C) • Propylene glycol (hereinafter also referred to as "PG"; boiling point 188.2°C) • Dipropylene glycol n-butyl ether (hereinafter also referred to as "DPnB"; boiling point 230°C) • Isopropyl alcohol (hereinafter also referred to as "IPA"; boiling point 82.4°C) • Propylene glycol monomethyl ether (hereinafter also referred to as "PM"; boiling point 121°C) Ethanol (boiling point 78°C) • Polyethylene glycol with a number-average molecular weight of 200 (hereinafter also referred to as "PEG200"; boiling point 250°C)

[0130] Furthermore, the following optional components were used. • Solvent: Water • Pigment: CI Pigment Blue 15:3 (hereinafter also referred to as "PB15:3"; product name "Heliogen Blue D7088", manufactured by BASF Japan, solids content 100% by mass) Pigment: Titanium dioxide (100% solid content by mass) • Surfactant: Nonionic organic surfactant (product name "TegoWet505", manufactured by BASF Japan) • Antifoaming agent: Product name "BYK-094" (manufactured by Big Chemie Japan, solid content 100% by mass) • Thickener: Product name "Taffygel PUD45D" (manufactured by MUNZING CHEMIE, solids content 40% by mass)

[0131] <Preparation of aqueous resin composition> Mixtures were obtained by mixing each component to achieve the composition (in parts by mass) shown in the upper section of Table 4 (Tables 4-1 to 4-7). The resulting mixtures were kneaded using a paint shaker to prepare the aqueous resin compositions for each example and comparative example.

[0132] The "Solid Content (%)", "Polyolefin Resin Content (%)", and "Wax Content (%)" shown in the lower section of Table 4 represent the content (mass%) of solids, polyolefin resin, and wax, respectively, based on the total mass of the aqueous resin composition. Furthermore, the "Polyolefin Resin Content in Solids (%)" and other component content (%) shown in the lower section of Table 4 represent the content (mass%) of each component based on the solids of the aqueous resin composition (excluding pigments if present). Additionally, the "Film-Forming Aid / Wax" shown in the lower section of Table 4 represents the mass ratio of the film-forming aid to the wax content in the aqueous resin composition. Similarly, the "Acrylic Resin Content (%) relative to Polyolefin Resin Content (%)" and "Urethane Resin Content (%) relative to Polyolefin Resin Content (%)" represent the proportion (mass%) of the acrylic resin and urethane resin content relative to the polyolefin resin content in the aqueous resin composition.

[0133] TIFF2026121158000004.tif246170

[0134] TIFF2026121158000005.tif245170

[0135] TIFF2026121158000006.tif246170

[0136] TIFF2026121158000007.tif245170

[0137] TIFF2026121158000008.tif230170

[0138] TIFF2026121158000009.tif229170

[0139] TIFF2026121158000010.tif229170

[0140] <Preparation of aqueous coating solution and manufacture of laminates> (Water-based coating liquid and laminate G for gravure printing) Each prepared aqueous resin composition was diluted with a diluent (water) to prepare an aqueous coating solution for printing, so that its viscosity at 25°C, as measured using a Zahn cup #3, was 25 seconds. Using a gravure printing press equipped with a Helio 250 lines / inch gravure engraving plate (product name "K Printing Proofer", manufactured by Matsuo Sangyo Co., Ltd.), the prepared aqueous coating solution was printed onto the treated surface of the substrate shown below by gravure printing, and then dried at 25°C for 24 hours to form a printed layer. In this way, a laminate G (see Figure 1), which is a printed material comprising a substrate and a printed layer provided on the substrate, was obtained using each aqueous resin composition (each aqueous coating solution).

[0141] (Water-based coating solution and laminate F for flexographic printing) Each prepared aqueous resin composition was diluted with water to prepare an aqueous coating solution for printing, so that its viscosity at 25°C, as measured using a Zahn cup #4, was 20 seconds. Using an anilox roll with a cell volume of 6 cc, the prepared aqueous coating solution was printed onto the treated surface of the substrate shown below by flexographic printing, and then dried at 25°C for 24 hours to form a printed layer. In this way, a laminate F (see Figure 1), which is a printed material comprising a substrate and a printed layer provided on the substrate, was obtained using each aqueous resin composition (each aqueous coating solution).

[0142] The following substrates were used for the laminates G and F described above. • OPP: OPP film with one side treated with corona discharge (product name "FOR", manufactured by Futamura Chemical Co., Ltd., thickness 30 μm) • PET: PET film with corona discharge treatment on one side (product name "Ester Film 8102", manufactured by Toyobo Co., Ltd., thickness 12 μm) • PS: PS film with corona discharge treatment on one side (product name "GMGS", manufactured by Gunze Corporation, 50 μm thick)

[0143] <Manufacturing of laminating film> For Examples 8-12 and 17, after manufacturing the laminate G in the same manner as described above, a dry laminating adhesive (product name "Seikabond E372 / C-76", manufactured by Dainichi Seika Kogyo Co., Ltd.) was applied to the printed layer of the laminate G (the side opposite to the substrate) at a dry application rate of 3 g / m². 2 An adhesive layer was formed by gravure printing. Next, an LLDPE film (product name "TUX HC", manufactured by Mitsui Chemicals Tohcello Co., Ltd., 60 μm thick) as the second substrate was heat-pressed onto the adhesive layer. After that, it was aged at 40°C for 48 hours. In this way, a laminate film (see Figure 2) was obtained, which is a printed material in which the first substrate (OPP or PET), the printed layer, the adhesive layer, and the second substrate (LLDPE) are laminated in this order.

[0144] <Rating> As shown below, the fluidity and storage stability of each aqueous resin composition in the examples and comparative examples, as well as the substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesiveness, scratch resistance, and haze of the coating layer (printed layer) in the laminate (printed material), were evaluated. The evaluation results are shown in Table 5 (Tables 5-1 to 5-7).

[0145] (Liquidity) After manufacturing, each aqueous resin composition was stored at 25°C for 24 hours, and its fluidity was visually inspected and evaluated according to the evaluation criteria shown below. ○: Has good liquidity. △: Possesses thixotropy, and some fluidity is impaired. ×: It does not have liquidity.

[0146] (Storage stability) After manufacturing, each aqueous resin composition was stored in a constant temperature and humidity chamber for one month in a cycle of 0°C to 40°C. The fluidity was then visually inspected and evaluated according to the evaluation criteria shown below. ○: Has good liquidity. △: Some liquidity has been impaired. ×: It does not have liquidity.

[0147] (Adhesion to substrate) After applying cellophane tape (manufactured by Nichiban Co., Ltd.) to the printed layer of the fabricated laminate F, the cellophane tape was promptly peeled off, and the condition of the printed layer remaining on the substrate film was visually inspected. The adhesion of the printed layer to the substrate was then evaluated according to the evaluation criteria shown below. 5: The printed layer has not peeled off at all. 4. The ratio of the area of ​​the peeled printed layer to the adhesive area of ​​the cellophane tape (peeling ratio) is greater than 0% and less than 20%. 3. The ratio of the area of ​​the peeled printed layer to the adhesive area of ​​the cellophane tape (peel ratio) is 20% or more and less than 50%. 2: The ratio of the area of ​​the peeled printed layer to the adhesive area of ​​the cellophane tape (peel ratio) is 50% or more and less than 70%. 1: The ratio of the area of ​​the peeled printed layer to the adhesive area of ​​the cellophane tape (peel ratio) is 70% or more and less than 100%.

[0148] (Blocking resistance) The printed layer of the fabricated laminate F was superimposed on the unprinted surface of the same base film, and a spring-type blocking test machine (OPP: 4kgf / cm²) was used. 3 PET: 7kgf / cm 3 The samples were stored under pressure at 40°C for 24 hours. After storage, the substrate film was peeled off the printed layer of the laminate F, and the condition of the printed layer transferred to the non-printed surface of the substrate film was visually inspected. The blocking resistance (retention power of the printed layer) of the printed layer was evaluated according to the evaluation criteria shown below. 5: The printed layer has not transferred to the non-printed surface of the substrate film. 4. The ratio of the area of ​​the printed layer transferred to the non-printed surface to the area of ​​the non-printed surface of the substrate film is greater than 0% and less than 20%. 3: The ratio of the area of ​​the printed layer transferred to the non-printed surface to the area of ​​the non-printed surface of the base film is 20% or more but less than 50%. 2: The ratio of the area of ​​the printed layer transferred to the non-printed surface to the area of ​​the non-printed surface of the substrate film is 50% or more but less than 70%. 1: The ratio of the area of ​​the printed layer transferred to the non-printed surface to the area of ​​the non-printed surface of the base film is 70% or more but less than 100%.

[0149] (Heat seal blocking resistance) The printed layer of the fabricated laminate F was superimposed on a 100 μm thick untreated PET film (product name "Ester Film E5000", manufactured by Toyobo Co., Ltd.), and the two layers were pressed together using a heat seal tester (product name "TP-701-C", manufactured by Tester Sangyo Co., Ltd.) under the conditions of 90°C, 0.3 MPa, and 3 minutes. After the pressing process, the PET film was peeled off from the printed layer of laminate F, and the state of the printed layer transferred to the PET film was visually inspected. The heat seal blocking resistance (heat resistance) of the printed layer was then evaluated according to the evaluation criteria shown below. 5: The printed layer has not transferred to the PET film. 4. The ratio of the area of ​​the printed layer transferred to the PET film to the area of ​​the printed layer being pressure-bonded is greater than 0% and less than 20%. 3. The ratio of the area of ​​the printed layer transferred to the PET film to the area of ​​the printed layer being pressure-bonded is 20% or more but less than 50%. 2: The ratio of the area of ​​the printed layer transferred to the PET film to the area of ​​the printed layer being pressure-bonded is 50% or more but less than 70%. 1: The ratio of the area of ​​the printed layer transferred to the PET film to the area of ​​the printed layer being pressure-bonded is 70% or more but less than 100%.

[0150] (Hot melt adhesive type) A printed layer in the fabricated laminate F and a film coated with hot-melt adhesive using a coater on a 100 μm thick PET film were sealed together using a heat seal tester (product name "TP-701-C", manufactured by Tester Sangyo Co., Ltd.) at 90°C, 0.2 MPa, and for 1 second, with the hot-melt adhesive layer in between, to create 10 mm wide strip-shaped test pieces. Using a universal tensile testing machine (product name "E3-L", manufactured by Toyo Seiki Seisakusho Co., Ltd.), the prepared test pieces were peeled (T-type peel) at a tensile speed of 300 mm / min, and the average load at the time of peeling was measured. The hot-melt adhesive properties of the printed layer were then evaluated according to the evaluation criteria shown below. 5. The average load during peeling is 6.0 N / 10 mm or more. 4. The average load at the time of peeling is 4.5 N / 10 mm or more and less than 6.0 N / 10 mm. 3: The average load at the time of peeling is 3.0 N / 10 mm or more and less than 4.5 N / 10 mm. 2: The average load at the time of peeling is 1.5 N / 10 mm or more and less than 3.0 N / 10 mm. 1: The average load during peeling is less than 1.5 N / 10 mm.

[0151] (Scratch resistance) The printed layer of the fabricated laminate F was visually inspected after performing a 10-back scratching operation with a fingernail in the width direction, and the scratch resistance of the printed layer was evaluated according to the evaluation criteria shown below. 5: No peeling of the printed layer. 4. The ratio of the area of ​​the detached printed layer to the test area of ​​the printed layer is greater than 0% and less than 20%. 3. The ratio of the area of ​​the detached printed layer to the test area of ​​the printed layer is 20% or more but less than 50%. 2: The ratio of the area of ​​the detached printed layer to the test area of ​​the printed layer is 50% or more but less than 70%. 1: The ratio of the area of ​​the detached printed layer to the test area of ​​the printed layer is 70% or more but less than 100%.

[0152] (Hayes) The fabricated laminate F was subjected to haze (%) measurement using a haze computer (product name "H2-2P", manufactured by Suga Test Instruments Co., Ltd.) in accordance with the provisions of JIS K-7136 (single beam, C light source measurement). The haze (%) of the same substrate used in laminate F was measured using the same method, and the haze (%) of the printed layer was obtained by subtracting the haze value of the substrate from the haze value of laminate F. The haze (%) of the printed layer was then evaluated according to the evaluation criteria shown below. 5. The haze of the printed layer is 10% or less. 4. The haze of the printed layer is greater than 10% but less than or equal to 15%. 3. The haze of the printed layer is greater than 15% but less than or equal to 20%. 2: The haze of the printed layer is between 20% and 25%. 1: The haze of the printed layer is over 25%.

[0153] (Dry lamination strength) The prepared laminate film was cut to create strip-shaped test pieces with a width of 15 mm. Using a universal tensile testing machine (product name "E3-L", manufactured by Toyo Seiki Seisakusho Co., Ltd.), the prepared test pieces were subjected to tensile peeling (T-type peeling) at a tensile speed of 300 mm / min, and the average load at the time of peeling was measured. The dry laminate strength was then evaluated according to the evaluation criteria shown below. The evaluation results are shown in Table 6. 5. The average load during peeling is 2.0 N / 15 mm or more. 4. The average load at the time of peeling is 1.6 N / 15 mm or more and less than 2.0 N / 15 mm. 3: The average load at the time of peeling is 1.2 N / 15 mm or more and less than 1.6 N / 15 mm. 2: The average load at the time of peeling is 0.8 N / 15 mm or more and less than 1.2 N / 15 mm. 1: The average load during peeling is less than 0.8 N / 15 mm.

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[0162] As shown in the results in Table 5, the aqueous resin compositions of Examples 1 to 29 exhibited good fluidity and storage stability. Furthermore, by using the aqueous resin compositions of the examples, aqueous coating liquids capable of forming a transparent coating layer (printed layer) with good substrate adhesion, blocking resistance, heat seal blocking resistance, hot melt adhesive properties, and scratch resistance were obtained.

[0163] Furthermore, as shown in the results in Table 6, by using the aqueous resin compositions of Examples 8-12 and 17, an aqueous coating solution capable of forming a coating layer (printed layer) with moderately high dry lamination strength was obtained, thereby yielding a laminate film with high dry lamination strength.

[0164] (Application Example 1) Laminates (laminated G-2 and F-2, respectively) were manufactured having a second printed layer formed by printing an aqueous coating solution using the same aqueous resin composition as in the examples above onto the printed layer (first coating layer) of laminates G and F of Examples 1 to 29, using the same printing method as for the first coating layer. The second coating layer in laminates G-2 and F-2 yielded the same results as those obtained for the first coating layer in Examples 1 to 29.

[0165] (Application Example 2) Examples 10-13, which used polyethylene-based wax, and Examples 14-16, which used paraffin-based wax, were compared separately when the coating layer was the outermost layer (front printing) and when the substrate was the outermost layer (back printing). Examples 10-13, which used polyethylene-based wax, were superior in terms of blocking resistance and dry laminate strength when back printing, while Examples 14-16, which used paraffin-based wax, were superior in terms of heat seal resistance and scratch resistance when front printing.

Claims

1. An aqueous resin composition used in an aqueous coating solution having a haze value of 15% or less of the coating film, It contains a resin emulsion and wax, The resin emulsion comprises a polyolefin resin emulsion containing a polyolefin resin having a melting point of 60 to 97°C and an acid value of 13 to 60 mgKOH / g. The wax comprises at least one selected from the group consisting of polyethylene-based waxes and paraffin-based waxes. The aqueous resin composition has a polyolefin resin content of 60 to 95% by mass and a wax content of 4 to 25% by mass, relative to the mass of solids. An aqueous resin composition in which the content of the wax relative to the content of the polyolefin resin is, by mass ratio, the polyolefin resin:wax = 1:0.043 to 1:0.

300.

2. The aqueous resin composition according to claim 1, wherein the polyolefin resin comprises at least one selected from the group consisting of polypropylene resin, polyethylene resin, and polypropylene-polyethylene copolymer.

3. It contains the aforementioned polyethylene wax aqueous dispersion, The aqueous resin composition according to claim 1, wherein the average particle size of the polyethylene-based wax is 0.3 to 8 μm.

4. The aqueous resin composition according to claim 1, wherein the melting point of the paraffin wax is 50 to 120°C.

5. The aqueous resin composition according to claim 1, wherein the content of the paraffin wax relative to the mass of the solids in the aqueous resin composition is 0 to 10% by mass.

6. Furthermore, the aqueous resin composition according to claim 1 contains a film-forming aid having a boiling point of 70 to 260°C.

7. The aqueous resin composition according to claim 6, wherein the content of the film-forming aid in the aqueous resin composition is 0.05 to 2.5 in mass ratio to the content of the wax.

8. The aqueous resin composition according to claim 6, wherein the film-forming aid comprises at least one selected from the group consisting of diethyldiglycol, propylene glycol, dipropylene glycol n-butyl ether, propylene glycol monomethyl ether, isopropyl alcohol, ethanol, and polyethylene glycol.

9. Furthermore, it contains a surfactant, The aqueous resin composition according to claim 1, wherein the content of the surfactant is 0.01 to 6% by mass with respect to the mass of the solid content of the aqueous resin composition.

10. The resin emulsion further comprises an acrylic resin emulsion containing an acrylic resin having a glass transition temperature of 75°C or higher. The aqueous resin composition according to claim 1, wherein the content of the acrylic resin in the aqueous resin composition is 35% by mass or less relative to the content of the polyolefin resin.

11. The resin emulsion further comprises a urethane resin emulsion containing a urethane resin, The aqueous resin composition according to claim 1, wherein the content of the urethane resin in the aqueous resin composition is 55% by mass or less relative to the content of the polyolefin resin.

12. The aqueous resin composition according to claim 1, further comprising at least one selected from the group consisting of curing agents and crosslinking agents.

13. The aqueous resin composition according to claim 1, which has excellent scratch resistance, wherein when a coating film obtained by applying the aqueous coating liquid containing the aqueous resin composition is rubbed in the width direction with a hard object, the ratio of the area of ​​the coating film that has peeled off to the test area of ​​the coating film after 10 back-and-forth strokes is less than 20%.

14. A solid resin composition obtained by drying the aqueous resin composition according to any one of claims 1 to 13.

15. A water-based coating solution having a haze value of 15% or less of the coating film, An aqueous coating solution comprising the aqueous resin composition according to any one of claims 1 to 13.

16. For flexographic printing or gravure printing, The aqueous coating liquid according to claim 15, which is an aqueous varnish, aqueous medium, aqueous primer, or aqueous reducer, or an aqueous ink containing a colorant.

17. The invention comprises a base material and a coating layer disposed on the base material, A laminate comprising a coating layer formed with the aqueous coating solution described in claim 16.

18. The laminate according to claim 17, which is a label or packaging material.

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