Water-based ink composition for cosmetic materials and cosmetic materials using the same

Abstract

To provide an aqueous ink for decorative material that is superior in long-term stability of ink, leveling properties, substrate adhesion, and blocking resistance, and also has superior suitability for thermal lamination.SOLUTION: An aqueous ink for decorative material includes an aqueous polyurethane resin (A) as a binder resin. The aqueous polyurethane resin (A) includes a polyester-based urethane resin (a) with a weight average molecular weight of 50000-2000000. The content of the polyester-based urethane resin (a) is 15-100 mass% relative to the total amount of the binder resin.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an aqueous ink composition for decorative materials and a decorative material using the same.

Background Art

[0002] In recent years, in building materials for decoration such as ceilings, furniture, walls, floors, kitchen cabinets, fittings, and exterior walls and louvers of single-family houses, condominiums, apartments, etc. (general housing), shopping malls, station buildings, etc. (commercial facilities), hospitals, schools, etc. (public facilities), it has become rare to use laminated wood or solid wood materials, etc., and they are often replaced with decorative materials. Decorative materials are obtained by printing a wood grain pattern, a stone grain pattern, an abstract pattern, etc. on a plastic substrate, and further thermally laminating the plastic substrate to paste the thermally laminated laminate on a wood substrate, a steel plate substrate, etc. Conventionally, vinyl chloride is often used as the above plastic substrate. This is because there are advantages such as the flexibility and workability of the substrate can be widely adjusted according to the addition amount of the plasticizer, it has excellent printing suitability, a decorative material can be made only by thermally laminating with a vinyl chloride substrate, and the productivity is good.

[0003] When printing the above patterns on a normal plastic substrate or the like, gravure printing or flexographic printing is generally used. As printing inks, not only organic solvent-based inks but also aqueous inks have been used. In recent years, due to the increasing requirements for reducing environmental load by reducing the discharge amount of organic solvents during printing, preventing solvent fires and other safety aspects, and reducing residual solvents in printed materials, aqueous gravure inks and aqueous flexographic inks have attracted particular attention.

[0004] On the other hand, printing inks for vinyl chloride substrates generally use acrylic resins or vinyl chloride vinyl acetate copolymer resins as the main binder to maintain printability and the physical properties of the coating film, and these are printing inks that mainly require organic solvents (Patent Documents 1 and 2). Therefore, as mentioned above, water-based printing inks for vinyl chloride substrates using water-based acrylic resin as the binder resin are being considered from an environmental perspective, but there are still many challenges in obtaining printability and physical properties of the coating film equivalent to those of organic solvent-based printing inks (Patent Document 3).

[0005] To date, printing inks have been developed for cosmetic applications that use urethane resin in water-based printing inks, enabling sufficient adhesion to vinyl chloride substrates even after heat lamination (Patent Document 4). However, challenges remain, such as resistance to blocking and color changes after heat lamination. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 06-286097 [Patent Document 2] Japanese Patent Application Publication No. 07-024976 [Patent Document 3] Japanese Patent Application Publication No. 08-113750 [Patent Document 4] Japanese Patent Publication No. 2021-147428 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to provide a water-based ink for decorative materials that exhibits excellent long-term stability, leveling properties, substrate adhesion, and blocking resistance, as well as good suitability for heat lamination. [Means for solving the problem]

[0008] In light of the above problems, the inventors conducted thorough research and found that these problems can be solved by using the printing ink described below, thus concluding the present invention.

[0009] In other words, the present invention relates to an aqueous ink for cosmetic materials containing an aqueous polyurethane resin (A) as a binder resin, wherein the aqueous polyurethane resin (A) contains a polyester-based urethane resin (a) with a weight-average molecular weight of 50,000 to 2,000,000.

[0010] Furthermore, the present invention relates to the above-mentioned water-based ink for decorative materials, wherein the content of polyester-based urethane resin (a) is 15 to 100% by mass relative to the total amount of binder resin.

[0011] Furthermore, the present invention relates to the above-mentioned aqueous ink for cosmetic materials, which contains a glycol-based solvent having a boiling point of 110 to 260°C.

[0012] Furthermore, the present invention relates to the above-mentioned aqueous ink for cosmetic materials, which contains a nonionic surfactant.

[0013] Furthermore, the present invention relates to the above-mentioned aqueous ink for cosmetic materials, which further contains a crosslinking agent having a functional group that reacts with an acidic group and / or a hydroxyl group, and wherein the aqueous polyurethane resin (A) has an acidic group and / or a hydroxyl group.

[0014] Furthermore, the present invention relates to the above-mentioned aqueous ink for cosmetic materials, wherein the crosslinking agent comprises at least one selected from the group consisting of hydrazide compounds, carbodiimide compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, and aziridine compounds.

[0015] Furthermore, the present invention relates to a printed material for cosmetic purposes, having a printed layer formed by printing the above-mentioned aqueous ink for cosmetic purposes onto a vinyl chloride substrate 1.

[0016] The present invention also relates to a laminated body for decorative materials, which sequentially includes a vinyl chloride base material 1, a printed layer formed by printing the above-mentioned aqueous ink for decorative materials, and a vinyl chloride base material 2.

[0017] The present invention also relates to a method for manufacturing a laminated body for decorative materials, which includes a step of obtaining a printed layer by printing the above-mentioned aqueous ink for decorative materials on a vinyl chloride base material 1 by gravure or flexographic printing, and a step of further laminating a vinyl chloride base material 2 on the printed layer by thermal lamination under the conditions of 80 to 200 °C.

Effects of the Invention

[0018] According to the present invention, it has become possible to provide an aqueous ink for decorative materials that is excellent in the aging stability, leveling property, substrate adhesion, and blocking resistance of the ink, and has good suitability for thermal lamination processing.

Modes for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described in detail with examples. However, the matters described below are examples or representative examples of the embodiments of the present invention, and the present invention is not limited to these contents unless it exceeds the gist thereof.

[0020] In the following description, the binder resin represents the binder resin used in the aqueous ink for decorative materials of the present invention. The aqueous resin may be a water-soluble resin or an aqueous emulsion resin.

[0021] The aqueous ink for decorative materials is preferably used as an aqueous gravure or flexographic ink. In the following description, the aqueous ink for decorative materials may be simply abbreviated as "ink" or "aqueous ink", which are synonymous. Also, the printed layer formed by the aqueous ink for decorative materials may be referred to as an "ink film" or an "ink layer", which are all synonymous.

[0022] (Aqueous polyurethane resin) The present invention relates to an aqueous ink for cosmetic materials containing an aqueous polyurethane resin. The use of an aqueous polyurethane resin improves substrate adhesion, heat lamination, light resistance, and heat and humidity resistance. The polyurethane resin preferably has an acid value that can be neutralized, and the acid value is preferably 15 to 60 mg KOH / g. Furthermore, it is preferable that the constituent units be a polyol and an isocyanate compound, and it is preferable that the polyol contains at least one of polyester polyol, polyether polyol, or polycarbonate polyol. In other words, the aqueous polyurethane resin preferably contains at least one selected from polyether-based urethane resin, polyester-based urethane resin, and polycarbonate-based urethane resin.

[0023] (Water-based polyurethane resin (A)) In the present invention, the aqueous polyurethane resin (A) functions as an aqueous binder resin for aqueous inks for cosmetic materials, and contains a polyester-based urethane resin (a) with a weight-average molecular weight of 50,000 to 2,000,000. This improves substrate adhesion, suitability for heat lamination, light resistance, and blocking resistance, and enables a balance of these performance characteristics.

[0024] Furthermore, the aqueous polyurethane resin (A) is preferably dissolved or dispersed in water using a neutralizing agent. That is, the aqueous polyurethane resin (A) is preferably used as an aqueous polyurethane resin (A) dispersion in the ink raw materials described later. However, the form of the aqueous polyurethane resin (A) is not limited to the above.

[0025] The aqueous polyurethane resin (A) dispersion described above preferably has a solid content of 15 to 40% by mass and a viscosity of 10 to 5000 mPa·s.

[0026] Here, "solids content" refers to the total mass percentage of non-volatile components in the composition, and viscosity represents the value obtained by the method described in JIS Z 8803:2011, measured at 25°C using a Type B viscometer.

[0027] [Neutralizing agent] Examples of the neutralizing agents mentioned above include lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, ammonia, trimethylamine, triethylamine, triethanolamine, 2-(dimethylamino)ethanol, 2-(diethylamino)ethanol, 2-amino-2-methyl-1-propanol, and the like. From the viewpoint of being less likely to remain in printed materials, it is preferable to include ammonia as a neutralizing agent.

[0028] The acid value of the aqueous polyurethane resin (A) is not particularly limited, but is preferably in the range of 5 to 100 mg KOH / g, more preferably 15 to 60 mg KOH / g, even more preferably 20 to 55 mg KOH / g, and particularly preferably 24 to 45 mg KOH / g. This is to maintain the dispersibility of the aqueous polyurethane resin in water.

[0029] On the other hand, the hydroxyl value of the aqueous polyurethane resin (A) is preferably 0.1 to 30 mg KOH / g. This is because it improves the solubility of the aqueous polyurethane resin in water, the water resistance of the printed layer, and the adhesion to the substrate. It is more preferable that it be 1 to 15 mg KOH / g. To introduce hydroxyl groups into the aqueous polyurethane resin, the terminal groups may be hydroxyl groups, or the side chains may have hydroxyl groups.

[0030] The weight-average molecular weight of the aqueous polyurethane resin (A) is preferably 50,000 to 2,000,000, and more preferably 100,000 to 1,800,000. This is because having the weight-average molecular weight of the aqueous polyurethane resin (A) within this range provides good properties such as printability, blocking resistance, heat lamination strength, and color change during heat lamination.

[0031] (Polyester-based urethane resin (a)) By incorporating polyester-based urethane resin (a) into the water-based polyurethane resin (A), substrate adhesion, suitability for heat lamination, light resistance, and blocking resistance are improved, enabling a balance of these performance characteristics.

[0032] The content of polyester-based urethane resin (a) is preferably 15 to 100% by mass, more preferably 25 to 100% by mass, even more preferably 35 to 100% by mass, and particularly preferably 45 to 100% by mass, relative to the total amount of binder resin, from the viewpoint of suitability for heat lamination and improvement of blocking resistance.

[0033] The polyester polyurethane resin (a) is not limited by the manufacturing method, but is preferably a polyester polyurethane resin which is a reaction product of an isocyanate compound with a polyol containing a polyester polyol, an acidic group-containing polyol, and optionally other polyols, or a polyester polyurethane resin which is a urethane prepolymer having an isocyanate group at the end, with the chain further extended by an amine compound. The formation of such a reaction product is preferably carried out in a solvent-free environment or in a solvent that is inert to the isocyanate compound.

[0034] [Polyol] A polyol is a compound having multiple hydroxyl groups. Preferably, the polyol has repeating units in its structure. By including polyester polyols, a polyester-based aqueous polyurethane resin can be synthesized.

[0035] Polyester polyols are not limited by their manufacturing method, but can be obtained by polycondensation reactions of polyhydric alcohols without repeating units in their structure with polyhydric carboxylic acids, or by ring-opening polymerization of polyhydric alcohols without repeating units in their structure with cyclic lactones, etc. Suitable polyhydric alcohols include diols and triols, for example, Linear diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol, Propylene glycol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol [also known as neopentyl glycol], 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2,4-diethyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, and other branched diols. Cyclohexane-1,4-dimethanol, 1-phenyl-1,2-ethanediol [also known as styrene glycol], 2,2-isopropylidene-4,4'-dicyclohexanol [also known as hydrogenated bisphenol A], N,N-bis(2-hydroxyethyl)aniline, N,N-bis(2-hydroxypropyl)aniline, and other ring-structure-containing diols, Triols such as glycerin, trimethylolpropane, and pentaerythritol are preferred examples.

[0036] Examples of polycarboxylic acids include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, trimellitic acid, and pyromellitic acid. Acid anhydrides of these can also be used. Examples of cyclic lactones include ε-caprolactone, δ-valerolactone, γ-butyrolactone, and lactide.

[0037] The polyester polyol preferably has a number average molecular weight of 500 to 5000, more preferably 800 to 4000, and even more preferably 1000 to 3000.

[0038] As the polyhydric alcohols mentioned above, linear diols and branched diols can be used in combination. Linear diols impart crystallinity, while branched diols impart flexibility, and by adjusting their balance, a tough ink film can be obtained. This results in good substrate adhesion, blocking resistance, and suitability for heat lamination.

[0039] It is preferable to use a polyether polyol in combination as the polyol. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Polyethylene glycol is preferred from the viewpoint of water dispersibility and other factors.

[0040] The polyethylene glycol described above preferably has a number average molecular weight of 200 to 5000, and more preferably 1000 to 3000. Furthermore, the mass ratio of polyethylene glycol to the total mass of aqueous polyurethane resin (A) is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, and even more preferably 2 to 10% by mass. Note that the ratio derived from polyol in the resin can be substituted with the raw material composition ratio.

[0041] Polycarbonate polyols can be used in combination as polyols. While the manufacturing method of the polycarbonate polyol is not limited, it can, for example, be obtained by a polycondensation reaction between a polyhydric alcohol and a carbonate compound.

[0042] Examples of the carbonate compounds mentioned above include dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, alkylene carbonates such as ethylene carbonate and propylene carbonate, and diaryl carbonates such as diphenyl carbonate.

[0043] (Polyol containing acidic groups) An acidic group-containing polyol is a compound that has an acidic group and multiple hydroxyl groups within the same molecule. Examples of acidic groups include carboxyl groups and sulfonic acid groups. Specific examples of acidic group-containing polyols include 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butyric acid, 2,2-bis(hydroxymethyl)valeric acid, and tartaric acid. From the viewpoint of reactivity, 2,2-bis(hydroxymethyl)propionic acid and 2,2-bis(hydroxymethyl)butyric acid are preferred. The acidic groups of the acidic group-containing polyol impart an acid value to the polyurethane resin. These acidic groups are neutralized by the above-mentioned neutralizing agent, which is thought to impart solubility and dispersibility in water to the aqueous polyurethane resin (A).

[0044] In addition to the polyols mentioned above, other polyols such as diols and triols can be used. Suitable examples of diols and triols are those listed in the description of polyester polyols.

[0045] (Isocyanate compounds) As the isocyanate compound, various known aromatic, aliphatic, or alicyclic diisocyanates can be used. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyluisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate. Representative examples include 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanate-methyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer isocyanates obtained by converting the carboxyl groups of dimer acids to isocyanate groups. These can be used individually or in combination of two or more. Dicyclohexylmethane-4,4'-diisocyanate is preferred in terms of the toughness of the resin film.

[0046] (Pigment) The aqueous ink for cosmetic materials of the present invention preferably contains a pigment. Suitable pigments for use in the aqueous ink for cosmetic materials of the present invention include organic and inorganic pigments commonly used in inks, paints, and recording materials. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindoline, quinophthalone, azomethine azo, dicutopyrrolopyrrole, and isoindoline pigments. Examples of inorganic pigments include carbon black, titanium dioxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, red iron oxide, aluminum, and mica. Pigments listed as CI pigments in the color index can be used as appropriate.

[0047] These pigments can be used individually or in combination of two or more. The above pigments are preferably present in an amount of 0.05 to 60% by mass of the total ink mass. In the case of organic pigments or carbon black, the amount is preferably 0.05 to 35% by mass, and in the case of inorganic pigments such as titanium dioxide or barium sulfate, the amount is preferably 5 to 60% by mass. Titanium dioxide is preferably titanium dioxide surface-coated with at least silica or alumina.

[0048] (Liquid medium) The aqueous ink for cosmetic materials of the present invention preferably contains water as a liquid medium. Furthermore, an organic solvent may be used to the extent that it does not impair the effect, and if used, it is preferably an alcohol-based organic solvent, a glycol solvent, or a glycol monoalkyl ether solvent. Examples of such alcohol-based organic solvents include ethanol, 1-propanol, 2-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, t-butanol, 2-methyl-2-propanol, etc. Examples of glycol solvents include ethylene glycol, propylene glycol, butylene glycol and other alkylene glycols, dipropylene glycol, diethylene glycol and other dialkylene glycols, tripropylene glycol, triethylene glycol and other trialkylene glycols, etc. Suitable glycol monoalkyl ether solvents include propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether and other propylene glycol monoalkyl ethers, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether and other dipropylene monoalkyl ethers, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether and other tripropylene glycol monoalkyl ethers, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether and other diethylene glycol monoalkyl ethers.

[0049] The aqueous ink for cosmetic materials of the present invention preferably contains at least one organic solvent selected from the above-mentioned glycol solvent and / or glycol monoalkyl ether solvent (hereinafter sometimes abbreviated as "glycol-based solvent"). The glycol-based solvent contained in the aqueous ink for cosmetic materials of the present invention preferably has a boiling point of 110 to 260°C. By containing a glycol solvent with a boiling point in this range, the long-term stability and leveling properties of the ink are improved, and all performance characteristics can be achieved simultaneously.

[0050] When the aqueous ink for cosmetic materials of the present invention contains the glycol-based solvent, its content is preferably 0.1% to 20%, more preferably 0.5% to 15%, even more preferably 2% to 10%, and particularly preferably 5% to 9% of the total mass of the ink, from the viewpoint of the ink's long-term stability and leveling properties.

[0051] (Additives) The water-based ink for cosmetic materials of the present invention may contain, as additives, a dispersant, an anti-blocking agent, a thickener, a rheology modifier, an antifoaming agent, a leveling agent, a preservative, a surface tension modifier, a pH adjuster, a wax, and the like.

[0052] (Dispersant) The aqueous ink for cosmetic materials of the present invention preferably contains a dispersant, and from the viewpoint of ink stability over time, it is particularly preferable to contain a nonionic surfactant. While various types of nonionic surfactants are known, such as acetylene-based, siloxane-based, acrylic-based, fluorine-based, and ether-based surfactants, it is preferable to include acetylene-based and / or ether-based surfactants in order to improve and balance the ink's long-term stability and leveling properties.

[0053] (pH) The aqueous ink for cosmetic materials of the present invention preferably has a pH of 6.5 to 10.0. For pH adjustment, it is preferable to use the inorganic hydroxides or amine compounds mentioned in the description of the neutralizing agents above.

[0054] (Crosslinking agent) The aqueous ink for cosmetic materials of the present invention preferably contains an aqueous polyurethane resin (A) having acidic groups and / or hydroxyl groups, and in that case, it is preferable to include a crosslinking agent having a functional group that reacts with the acidic groups and / or hydroxyl groups. By using a crosslinking agent, the aqueous polyurethane resin (A) is crosslinked, thereby improving the substrate adhesion, heat lamination strength, hue change during heat lamination, lightfastness, and heat and humidity resistance of the aqueous ink.

[0055] Examples of functional groups that react with the above-mentioned acidic groups and / or hydroxyl groups include isocyanate groups, blocked isocyanate groups, epoxy groups, oxetane groups, aziridine groups, carbodiimide groups, amino resins, alkoxysilanes, and the like.

[0056] As the crosslinking agent, at least one selected from the group consisting of hydrazide compounds, carbodiimide compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, and aziridine compounds can be suitably selected.

[0057] Preferred hydrazide compounds include adipic acid dihydrazide, sebacate acid dihydrazide, isophthalic acid dihydrazide, and other dihydrazide compounds.

[0058] Carbodiimide compounds are compounds that contain a carbodiimide group, and examples include Carbodilite E-02, E-03A, SV-02, V-02, V02-L2, and V-04 manufactured by Nisshinbo Chemical Co., Ltd.

[0059] Oxazoline compounds are compounds containing an oxazoline group, and examples include Epocross K-2010E and WS-700 manufactured by Nippon Shokubai Co., Ltd.

[0060] Epoxy compounds are compounds that have an epoxy group, and examples include Denacol EX614B manufactured by Nagase ChemteX Corporation, Tedrad X manufactured by Mitsubishi Chemical Corporation, and Adeka Resin EP-4000, EP-4005, and 7001 manufactured by ADEKA Corporation.

[0061] Isocyanate compounds are compounds that contain an isocyanate group, and examples include Duranate WB40-100 manufactured by Asahi Kasei Corporation and Aquanate 105 manufactured by Tosoh Corporation.

[0062] Aziridine compounds are compounds that contain an aziridine group, and examples include PZ-33 and DZ-22E from Nippon Shokubai Co., Ltd.

[0063] The crosslinking agent can be used in one or more types simultaneously, preferably in an amount of 1 to 30% by mass relative to the total mass of ink solids, and more preferably in an amount of 2 to 20% by mass. Furthermore, the mass ratio of the crosslinking agent to 100% by mass of the aqueous polyurethane resin (A):crosslinking agent is preferably 100:1 to 100:50, and even more preferably 100:2.5 to 100:30. This is because it results in good thermal lamination strength of the laminate using the aqueous ink.

[0064] <Method for manufacturing water-based ink for cosmetic materials> The present invention provides a method for producing an aqueous ink for cosmetic materials, which preferably involves mixing predetermined amounts of aqueous polyurethane resin, and optionally pigment, water, organic solvent, and dispersant, followed by a further step of dispersion (pigment dispersion) using a bead mill or the like. The resulting dispersion can also be further blended with an antifoaming agent, water, etc., as needed to produce an aqueous ink for cosmetic materials. Commonly used dispersers such as roller mills, ball mills, pebble mills, attritors, and sand mills can be used for the pigment dispersion. Among these, dispersion using a sand mill, gamma mill, or other bead mill is preferred.

[0065] The viscosity of the aqueous ink for cosmetic materials of the present invention is preferably 10 to 1000 mPa·s, from the viewpoint of achieving the effects of the present invention. This viscosity represents the value obtained by the method described in JIS Z 8803:2011 and is a measurement value at 25°C using a B-type viscometer.

[0066] <Print> The water-based ink for cosmetic materials of the present invention can be printed using any printing method, and there are no particular limitations. Among these, gravure printing or flexographic printing methods are particularly suitable.

[0067] <Flexographic printing> (Anilox Roll) For use in flexographic printing, the anilox can be a ceramic anilox roll with cell engraving, a chrome-plated anilox roll, or the like. To obtain printed materials with excellent dot reproducibility, it is preferable to use an anilox roll with a line count of 5 times or more, preferably 6 times or more, the line count used for printing. For example, if the line count used is 75 lpi, an anilox roll of 375 lpi or higher is preferable, and if the line count is 150 lpi, an anilox roll of 750 lpi or higher is preferable. Regarding the anilox capacity, from the viewpoint of drying properties and blocking properties of the aqueous flexographic ink of the present invention, it should be 1 to 8 cc / m². 2 Capacity, preferably 2-6 cc / m³ 2 This is an anilox roll.

[0068] (Flexographic version) The printing plates used in the flexographic printing method for the flexographic prints of the present invention include photosensitive resin plates that utilize ultraviolet curing by a UV light source, and elastomer material plates that use a direct laser engraving method. Regardless of the method of forming the image portion of the flexographic plate, it is preferable to use a plate with a screening screen count of 75 lpi or higher. Any type of sleeve or cushioning tape can be used to attach the plate.

[0069] (printing machine) Flexographic printing presses include CI-type multi-color flexographic printing presses and unit-type multi-color flexographic printing presses. Ink supply methods include chamber type and two-roll type, and the appropriate printing press can be used.

[0070] Gravure printing (Gravure version) In the gravure printing described above, the gravure plate is a cylindrical metal plate, and recesses are created in each color by engraving, etching, or laser. There are no restrictions on the use of engraving or laser, and they can be set as desired according to the design. Line screens of 75 to 250 are used as appropriate, with higher line screens allowing for finer printing. The thickness of the printed layer is preferably 0.1 μm to 100 μm.

[0071] (printing machine) In a gravure printing press, each printing unit is equipped with the aforementioned gravure plate and doctor blade. Multiple printing units are available, and units corresponding to organic solvent-based printing inks and image inks can be configured. Each unit has an oven drying unit. Printing is performed by rotary press using a roll printing method. The type of plate and doctor blade are selected as appropriate, according to the specifications.

[0072] <Printed materials for cosmetic products> One embodiment of the present invention is a printed material for cosmetic purposes having a printed layer formed by printing the aqueous ink for cosmetic purposes of the present invention onto a vinyl chloride substrate 1.

[0073] A printed material for cosmetic purposes can be obtained by printing and transferring an aqueous ink for cosmetic purposes onto the vinyl chloride substrate 1, then thoroughly drying it to remove volatile components such as water and organic solvents. Gravure printing or flexographic printing are preferred methods for printing onto the vinyl chloride substrate 1.

[0074] <Vinyl chloride base material 1> As the vinyl chloride substrate 1 described above, a colorless, transparent, or colored vinyl chloride substrate is preferred, which is formed into a film by mixing in plasticizers, stabilizers, lubricants, fillers, pigments, dyes, and other colorants as needed. The thickness of the substrate is preferably 20 to 1000 μm. A rigid vinyl chloride substrate with a softening temperature of 60 to 90°C, a semi-rigid vinyl chloride substrate with a softening temperature of 15 to 50°C, or a flexible vinyl chloride substrate with a softening temperature of -20 to 0°C can be suitably selected depending on the application, but the substrate is not particularly limited.

[0075] <Laminated material for decorative purposes> In the above-mentioned printed material for decorative purposes, a laminate for decorative purposes can be obtained by layering a vinyl chloride substrate 2 onto a printed layer of vinyl chloride substrate 1 and bonding them together by applying heat and pressure (heat lamination). Methods for obtaining the above-mentioned laminate for decorative purposes include using a roll of printed material to continuously laminate the vinyl chloride substrate 2 and then cutting it to the required size, or cutting the printed material to the required size, then aligning the vinyl chloride substrate 2 to match that size, and laminating it by applying heat and pressure. In the above-mentioned heat lamination, the temperature is 80-200°C and the pressure is 0.1-100 kg / cm². 2 The process is preferably carried out under conditions where the time is between 1 and 3600 seconds.

[0076] <Vinyl chloride base material 2> The vinyl chloride substrate 2 can be the same as the vinyl chloride substrate 1 described above, but it is preferable that the vinyl chloride substrate 1 and / or vinyl chloride substrate 2 are transparent so that the printed layer can be seen through the vinyl chloride substrate. Using either a transparent vinyl chloride substrate 1 or vinyl chloride substrate 2, and a colored, opaque vinyl chloride substrate for the other, is preferable because it reduces the impact of color unevenness in wood or metal substrates, etc., when the laminated material is bonded to it after being made into a decorative laminate. The laminated material for decorative purposes obtained by the above method can be bonded to a wood-based substrate such as particleboard or MDF (medium-density fiberboard), or a metal substrate such as aluminum plate or steel plate, via an adhesive or the like, depending on the application, to create a decorative material. [Examples]

[0077] More specific embodiments of the present invention will be described below in examples and comparative examples, but the present invention is not limited to the following embodiments. Unless otherwise specified, "parts" and "%" in the examples and comparative examples refer to "parts by mass" and "% by mass," respectively.

[0078] (Weight average molecular weight) The weight-average molecular weight is the polystyrene equivalent value measured by GPC (gel permeation chromatography). A 0.5% solution was prepared by dissolving the dried resin in tetrahydrofuran, and the weight-average molecular weight was measured using a Shodex GPC-104 (column number LF-404, molecular weight measurement range approximately 3 million to 2 million).

[0079] (Hydroxyl value and acid value) The method was determined according to the method described in JIS K0070.

[0080] Table 1 shows a list of polyols that serve as raw materials for the synthesis of aqueous polyurethane resin (A) in the present invention. Note that all listed ratios represent the molar ratio of the corresponding compound. PES1-3 refer to polyester polyols that are dehydrated condensates of alkylene glycol and dicarboxylic acid, as described in Table 1. For example, PES1 is a polyester polyol that is a dehydrated condensate of 1,6-hexanediol and adipic acid.

[0081] [Table 1]

[0082] [Synthesis Example 1] (Synthesis of water-based polyurethane resin PU1) In a reactor equipped with a reflux condenser, dropping funnel, gas inlet tube, stirrer, and thermometer, 56.5 parts of PES1, 2.6 parts of PE1, 8.4 parts of 2,2-bis(hydroxymethyl)propionic acid (DMPA), and 61.6 parts of methyl ethyl ketone were charged while introducing nitrogen gas. 30.1 parts of dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI) were added dropwise over 1 hour with stirring, and the mixture was reacted at 85°C for 4 hours to obtain a terminal isocyanate prepolymer. After cooling to 30°C, 20.5 parts of methyl ethyl ketone were added to obtain a solvent solution of the terminal isocyanate prepolymer. To the obtained terminal isocyanate prepolymer, a mixture of 1.9 parts N-(2-hydroxyethyl)ethylenediamine (AEA), 0.5 parts isophoronediamine (IPDA), 12.3 parts 2-propanol, 239.0 parts water, and 5.2 parts triethylamine was gradually added at room temperature, and the mixture was reacted at 40°C for 6 hours to obtain a polyurethane resin solution. Next, methyl ethyl ketone and isopropyl alcohol were removed by distillation under reduced pressure, and then water was added to adjust the solid content to obtain aqueous polyurethane resin PU1 with an acid value of 35 mg KOH / g, a hydroxyl value of 10 mg KOH / g, a weight-average molecular weight of 1,000,000, and a solid content of 28%.

[0083] [Synthesis Examples 2-6] (Synthesis of water-based polyurethane resins PU2-6) Aqueous polyurethane resins PU2 to PU6 were obtained in the same manner as in Synthesis Example 1, except that the raw material compounds shown in Table 2 were used. [Synthesis Examples 7-8] (Synthesis of water-based polyurethane resins PU7-8) Using the raw material compounds shown in Table 2, the synthesis was carried out according to the method described in the examples of Japanese Patent Publication No. 2021-147428 to obtain aqueous polyurethane resins PU7-8.

[0084] [Table 2]

[0085] [Example 1] (Manufacturing of Ink S1) 66 parts of PU1 as an aqueous polyurethane resin (A), 10 parts of phthalocyanine pigment (Lionol Blue FG7358G, manufactured by Toyo Color Co., Ltd.) as an organic pigment, 1 part of Surfinol GA (manufactured by Nisshin Chemical Industry Co., Ltd., 78% solids) and 1 part of Newcol 780-60 (manufactured by Nippon Emulsifier Co., Ltd., 60% solids) as dispersants, 0.1 part of DOWSIL FS ANTIFOAM 1277 (manufactured by Dow Chemical Japan Ltd., 23% solids) as an antifoaming agent, 6 parts of propylene glycol and 2 parts of tripropylene glycol methyl ether as glycol solvents, and 5.9 parts of ion-exchanged water were stirred and mixed, then dispersed in a sand mill for 30 minutes, and then 8 parts of the crosslinking agent CL1 (Carbodilite E-02, carbodiimide-based crosslinking agent, 40% solids, manufactured by Nisshinbo Chemical Co., Ltd.) were stirred and mixed to obtain aqueous ink S1.

[0086] [Examples 2-24, Comparative Examples 1-5] (Manufacturing of inks S2-S24 and R1-R5) Inks S2-S24 and R1-R5 were obtained using the same method as for ink S1, except that the raw materials and mixing ratios listed in Table 3 were used. The abbreviations in the table are as follows. Red iron oxide pigment: Toda Color KNO, manufactured by Toda Kogyo Co., Ltd. Neoacrylic A-1127: Manufactured by DSM, water-based acrylic resin, solids content 44% Vinibran 900GT: Manufactured by Nisshin Chemical Industry Co., Ltd. Vinyl chloride emulsion resin, solids content 40% Acrylic resin aqueous solution: An aqueous solution of acrylic resin prepared according to the method described in Production Example 1 of Japanese Patent Publication No. 08-113750, with a solid content of 25%. Crosslinking agent CL2: Manufactured by Tokyo Chemical Industry Co., Ltd. Dihydrazide adipic acid, hydrazide-based crosslinking agent, 100% solids content. Crosslinking agent CL3: Epoxycross WS-700, manufactured by Nippon Shokubai Co., Ltd., oxazoline-based crosslinking agent, solid content 25% Crosslinking agent CL4: Denacol EX614B epoxy crosslinking agent, manufactured by Nagase ChemteX Corporation, 100% solids content. Crosslinking agent CL5: Asahi Kasei Corporation, Duranate WB40-100, isocyanate-based crosslinking agent, 100% solids content. Crosslinking agent CL6: Chemitite PZ-33, manufactured by Nippon Shokubai Co., Ltd., aziridine-based crosslinking agent, 100% solids content.

[0087] [Table 3]

[0088] [Example 1] (Gravure printing of ink S1 onto a vinyl chloride substrate) The above-mentioned water-based ink S1 was used in a gravure printing press equipped with an electronically engraved gravure plate (250 LPI) to print on a semi-rigid polyvinyl chloride substrate (80 μm thick, substrate containing 12 parts plasticizer per 100 parts polyvinyl chloride resin) at a speed of 40 m / min and a drying temperature of 60°C to obtain a printed material.

[0089] [Examples 2-24, Comparative Examples 1-5] (Gravure printing on vinyl chloride substrate with inks S2-S24 and R1-R5) Gravure printing was performed using the same method as for ink S1, except that inks S2-S21 and R1-R5 were used instead of ink S1, and printed materials were obtained.

[0090] <Performance Evaluation> The following evaluations were performed using the inks and printed materials obtained in the above examples and comparative examples. The results are shown in Table 4.

[0091] [Ink stability over time] Inks S1-S24 and R1-R5 were placed in glass bottles, sealed tightly, and stored at 40°C for 7 days. After storage, changes in the ink's state (viscosity, separation, and sedimentation) were evaluated. Viscosity change was evaluated as the percentage change in the flow time in a Zaan cup (manufactured by Rigosha) at 25°C before and after storage. Separation and sedimentation were evaluated by visual inspection. (Evaluation Criteria) A: Viscosity change rate is less than 10%, and there is no separation or precipitation. B: Viscosity change rate is between 10% and 30%, and there is no separation or precipitation. C: Viscosity change rate is between 30% and 50%, with slight separation and precipitation. D: Viscosity change rate is 50% or more (but fluidity is present), and there is significant separation and precipitation. E: Loss of fluidity, gelation occurs. Industrially applicable ratings are A, B, or C.

[0092] [Leveling ability] The uniformity of the density of the printed surface (presence or absence of printing unevenness and / or pinholes) was visually evaluated for the printed materials obtained in Examples 1 to 21 and Comparative Examples 1 to 5. "Printing inconsistencies" refer to a condition where, after ink printing, the dried ink film is not formed smoothly during the drying process, resulting in minute variations in color intensity on the printed surface. "Pinholes" refer to a condition where, after ink printing, the dried ink film is not formed smoothly during the drying process, resulting in minute, dot-like defects on the printed surface. (Evaluation Criteria) A: No printing inconsistencies or pinholes. B: Slight printing inconsistencies, no pinholes. C: There are slight printing inconsistencies and pinholes. D: There are obvious printing inconsistencies and pinholes. E: There are significant printing inconsistencies and pinholes. Industrially applicable ratings are A, B, or C.

[0093] [Adhesion to substrate] The substrate adhesion of the printed materials obtained in Examples 1 to 21 and Comparative Examples 1 to 5 was evaluated using JIS K5600-5-6. (Evaluation Criteria) A: No ink peeling from the substrate. B: The area of ​​ink peeling from the substrate is less than 5%. C: The area of ​​ink peeling from the substrate is 5% or more and less than 15%. D: The area of ​​ink peeling from the substrate is 15% or more, but less than 50%. E: The area of ​​ink peeling from the substrate is 50% or more. Industrially applicable ratings are A, B, or C.

[0094] [Blocking resistance] For the printed materials obtained in Examples 1-21 and Comparative Examples 1-5, the printed side and the non-printed side were superimposed and weighed at 10 kg / cm². 2 After applying pressure and leaving the samples in a 40°C-80%RH environment for 24 hours, the pressure was released, and the ink transfer to the non-printed surface and the peel resistance were evaluated when the overlapping surfaces were separated. (Evaluation Criteria) A: There is no ink transfer, and no peeling resistance is felt. B: There is no ink transfer, but some peeling resistance can be felt. C: Ink transfer occurs in areas of less than 5%, and peel resistance is felt. D: Ink transfer is observed in an area of ​​5% to less than 50%, and peel resistance is felt. E: Ink transfer occurs over 50% of the area, and significant peeling resistance is felt. Industrially applicable ratings are A, B, or C.

[0095] (Laminated structure) The printed materials obtained in Examples 1-24 and Comparative Examples 1-5 were subjected to thermal lamination under two conditions to obtain laminates.

[0096] (Fabrication of laminates for decorative materials (Condition 1)) In the printed materials obtained in the above examples and comparative examples, a semi-rigid vinyl chloride substrate (150 μm thick, containing 12 parts plasticizer per 100 parts vinyl chloride resin) different from the printing substrate was added to the printed layer side, and the temperature was set to 145°C and 2 kg / cm². 2 Then, thermal lamination was performed under conditions of 30 seconds to obtain laminate 1.

[0097] (Fabrication of laminates for decorative materials (Condition 2)) In the printed materials obtained in the above examples and comparative examples, a semi-rigid polyvinyl chloride substrate (300 μm thick, containing 12 parts plasticizer per 100 parts polyvinyl chloride resin) different from the printing substrate was added to the printed layer side, and the material was heated at 150°C and 24 kg / cm². 2 Then, thermal lamination was performed under conditions of 30 minutes to obtain laminate 2.

[0098] [Thermal lamination strength] In the preparation of the decorative laminate described above, the laminate strength of laminates 1 and 2 obtained under conditions (1) and (2) was measured using a tensile testing machine. (Evaluation Criteria) A: The substrate breaks, or the peel strength is 15N / 15mm or more. B: Peel strength of 10N / 15mm or more and less than 15N / 15mm C: Peel strength of 5N / 15mm or more and less than 10N / 15mm D: Peel strength greater than 0 N / 15 mm and less than 5 N / 15 mm E: Peel strength is 0N / 15mm Industrially applicable ratings are A, B, or C.

[0099] [Color changes during thermal lamination] For the decorative laminates obtained by fabricating the above-mentioned decorative laminate (Condition 2), the difference in hue (color difference ΔE) compared to the state of the printed material before thermal lamination was evaluated. The color difference ΔE was measured using an X-Rite Exact spectrophotometer. (Evaluation Criteria) A: Chromatic difference ΔE is less than 2 B: Chromatic difference ΔE is between 2 and 4. C: Chromatic difference ΔE is 4 or greater and less than 6. D: Chromatic difference ΔE is between 6 and 10. E: Chromatic difference ΔE is 10 or greater Industrially applicable ratings are A, B, or C.

[0100] [Lightfastness] Regarding the decorative laminate obtained in the above-mentioned preparation of the decorative laminate (Condition 2), a Hayasaka Riko Co., Ltd. auto fade meter was used with a black panel temperature of 63°C, chamber humidity of 35%RH, and sample surface irradiance of 500W / m². 2 After conducting a 100-hour lightfastness test under these conditions, the laminate strength was measured using a tensile testing machine. (Evaluation Criteria) A: The substrate breaks, or the peel strength is 15N / 15mm or more. B: Peel strength of 10N / 15mm or more and less than 15N / 15mm C: Peel strength of 5N / 15mm or more and less than 10N / 15mm D: Peel strength greater than 0 N / 15 mm and less than 5 N / 15 mm E: Peel strength is 0N / 15mm Industrially applicable ratings are A, B, or C.

[0101] [Heat and moisture resistance] The laminated material obtained in the preparation of the above-mentioned laminated material for decorative materials (Condition 2) was stored for 7 days in an environment of 60°C and 90%RH, and then its laminate strength was measured using a tensile testing machine. (Evaluation Criteria) A: The substrate breaks, or the peel strength is 15N / 15mm or more. B: Peel strength of 10N / 15mm or more and less than 15N / 15mm C: Peel strength of 5N / 15mm or more and less than 10N / 15mm D: Peel strength greater than 0 N / 15 mm and less than 5 N / 15 mm E: Peel strength is 0N / 15mm Industrially applicable ratings are A, B, or C.

[0102] [Table 4]

Claims

1. A water-based ink for cosmetic materials containing a solvent and an aqueous polyurethane resin (A) as a binder resin, The aqueous polyurethane resin (A) contains a polyester-based urethane resin (a) having a weight-average molecular weight of 100,000 to 2,000,000, and the acid value of the aqueous polyurethane resin (A) is 5 to 100 mg KOH / g. A water-based ink for cosmetic materials, wherein the solvent contains a glycol-based solvent having a boiling point of 110 to 260°C.

2. The water-based ink for decorative materials according to claim 1, wherein the content of polyester urethane resin (a) is 15 to 100% by mass relative to the total amount of binder resin.

3. Furthermore, the aqueous ink for cosmetic materials according to claim 1 or 2 further contains a nonionic surfactant.

4. Furthermore, the aqueous ink for cosmetic materials according to any one of claims 1 to 3, further comprising a crosslinking agent having a functional group that reacts with an acidic group and / or a hydroxyl group, and wherein the aqueous polyurethane resin (A) has an acidic group and / or a hydroxyl group.

5. The aqueous ink for cosmetic materials according to claim 4, wherein the crosslinking agent comprises at least one selected from the group consisting of hydrazide compounds, carbodiimide compounds, oxazoline compounds, epoxy compounds, isocyanate compounds, and aziridine compounds.

6. A printed material for decorative purposes, having a printed layer on a vinyl chloride substrate 1, wherein an aqueous ink for decorative purposes according to any one of claims 1 to 5 is printed.

7. A laminate for decorative materials comprising, in sequence, a vinyl chloride substrate 1, a printed layer printed with an aqueous ink for decorative materials according to any one of claims 1 to 5, and a vinyl chloride substrate 2.

8. A method for manufacturing a laminate for decorative materials, comprising the steps of: obtaining a printed layer by printing an aqueous ink for decorative materials described in any one of claims 1 to 5 onto a vinyl chloride substrate 1 by gravure or flexographic printing; and further laminating a vinyl chloride substrate 2 onto the printed layer by heat lamination under conditions of 80 to 200°C.

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