JP2007153958A - Aqueous primer composition and layered product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous primer composition which shows high adhesion especially to an ultraviolet-curable ink and can be dried at a relatively low temperature within a relatively short time. <P>SOLUTION: The aqueous primer composition contains, against 100 pts.mass polyurethane resin (A), 3-60 pts.mass epoxy compound (B) and 10-100 pts.mass isocyanate compound (C). The primer composition is especially intended for use with an ultraviolet-curable ink. A layered product is obtained by forming a coating film derived from the primer composition on a thermoplastic resin substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aqueous primer composition having good adhesion of ultraviolet curable ink.

  Various thermoplastic resin films are generally used after being printed in product packaging and other applications. As the ink for printing, an ultraviolet curable ink (hereinafter referred to as UV ink) that is easy to use and rich in design such as patterns and colors is used. Since UV ink has the property of easily shrinking when cured, there is a problem that the ink layer is not sufficiently adhered when used directly on the surface of a thermoplastic resin substrate such as PET or polyolefin resin. Therefore, it has been studied to improve ink adhesion by providing various primer layers on the surface of the resin substrate.

  For example, Patent Document 1 discloses a primer composition in which a component mainly composed of a polycarbonate polyurethane resin and an isocyanate compound is dissolved in methyl ethyl ketone, and shows excellent adhesion to UV ink. Patent Document 2 discloses a water-based primer coat agent composition containing an aromatic polyester polyurethane and a melamine resin, which is excellent in heat and moisture resistance and boil retort resistance.

JP 2002-316394 A JP 2000-026798 A

  Since the primer composition described in Patent Document 1 is a primer using an organic solvent, it is not necessarily preferred from the viewpoint of environmental hygiene in recent workplaces.

  Moreover, since the primer of patent document 2 uses melamine resin as a crosslinking agent, the conditions of higher temperature and long time were required as drying conditions at the time of coating.

  In order to solve the above problems, the present inventors intend to provide a primer composition which is a water-based primer, particularly has good adhesion to UV ink, and can be dried at a relatively low temperature and in a short time. It is.

  As a result of intensive studies, the present inventors have solved the above problem by containing an epoxy compound and an isocyanate compound in a specific ratio with respect to the urethane resin. It has been found that it has excellent properties such as transparency, scratch resistance (a property that is not easily scratched), and blocking resistance, and has reached the present invention.

That is, the gist of the present invention is as follows.
(1) A water-based primer composition containing 100 parts by mass of a polyurethane resin (A), 3 to 60 parts by mass of an epoxy compound (B), and 10 to 100 parts by mass of an isocyanate compound (C).
(2) A laminate obtained by forming a coating film obtained from the aqueous primer composition described in (1) on a thermoplastic resin substrate.
(3) A laminate in which the coating surface of the laminate according to (2) is printed with ultraviolet curable ink.

  Since the water-based primer composition of the present invention is water-based, it is safe and has a low environmental impact. In addition, thin coating is possible, and it is excellent in workability because it can be dried at a relatively low temperature and in a short time.

  The formed coating film is excellent in adhesiveness to various thermoplastic resin film substrates. In addition, the ink adhesion on the surface of the coating film, particularly the UV ink adhesion, which is difficult to adhere, is excellent, and the transparency and scratch resistance of the coating film are also good.

  Moreover, since the base-material adhesiveness of a coating film and the blocking resistance of the coating surfaces are maintained, it can wind up with a roll or can load and preserve | save.

  Since the properties of adhesion to the substrate and ink adhesion (particularly adhesion to UV ink) last for a long time, they can be used well after long-term storage or after export by sea mail.

  Since a coating film is excellent in adhesiveness with an adhesive, it can be used as a clear case or a clear box by assembling and bonding a laminated body provided with a coating film. If used in such applications, it is excellent in transparency and scratch resistance, so that the surface is hardly scratched and the contents can be seen through for a long period of time, and the commercial value and aesthetics are less deteriorated.

  The present invention will be described in detail below.

  The polyurethane resin (A) used in the present invention is a polymer containing a urethane bond in the main chain, and is obtained, for example, by a reaction between a polyol compound and a polyisocyanate compound.

  The polyol component constituting the polyurethane resin is not particularly limited. For example, water, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1 , 3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1,3-hexane Low molecular weight glycols such as diol, diethylene glycol, triethylene glycol, and dipropylene glycol; low molecular weight polyols such as trimethylolpropane, glycerin, and pentaerythritol; and polyols having ethylene oxide and propylene oxide units. Le compounds, polyether diols, high molecular weight diols such as polyester diols, bisphenols such as bisphenol A, bisphenol F, dimer diol, and the like to the carboxyl group of the dimer acid was converted to hydroxyl groups.

  Further, as the polyisocyanate component, one or a mixture of two or more known aromatic, aliphatic and alicyclic known diisocyanates can be used. Specific examples of the diisocyanates include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, Examples include lysine diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimerized isocyanate obtained by converting a carboxyl group of dimer acid to an isocyanate group, and adducts, biurets, and isocyanurates. As the diisocyanate, trifunctional or higher functional polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate may be used.

  The polyurethane resin in the present invention preferably has an anionic group from the viewpoint of dispersibility in an aqueous medium. An anionic group is a functional group that becomes an anion in an aqueous medium, and examples thereof include a carboxyl group, a sulfonic acid group, a sulfuric acid group, and a phosphoric acid group. Among these, it is preferable that it has a carboxyl group from the reactivity with the epoxy compound and isocyanate compound which are mentioned later.

  In order to introduce an anionic group into the polyurethane resin, a polyol component having a carboxyl group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group or the like may be used. As a polyol compound having a carboxyl group, 3,5-dihydroxy is used. Benzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxyethyl) propionic acid, 2,2-bis (hydroxypropyl) propionic acid, bis (hydroxymethyl) acetic acid, bis (4- Hydroxyphenyl) acetic acid, 2,2-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-dihydroxyethylglycine, N, N-bis (2-hydroxyethyl) -3-carboxyl-propionamide and the like. It is done.

  The molecular weight of the polyurethane resin can be adjusted as appropriate using a chain extender. Examples of such compounds include compounds having two or more active hydrogens such as amino groups and hydroxyl groups capable of reacting with isocyanate groups. For example, diamine compounds, dihydrazide compounds, and glycols can be used.

  Examples of the diamine compound used as a chain extender for polyurethane include ethylenediamine, propylenediamine, hexamethylenediamine, triethyltetramine, diethylenetriamine, isophoronediamine, and dicyclohexylmethane-4,4′-diamine. Other examples include diamines having a hydroxyl group such as N-2-hydroxyethylethylenediamine and N-3-hydroxypropylethylenediamine, and dimer diamine obtained by converting the carboxyl group of dimer acid into an amino group. Furthermore, diamine type amino acids such as glutamic acid, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid and diaminobenzenesulfonic acid are also included. Examples of the dihydrazide compound include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacin dihydrazide, etc., saturated aliphatic dihydrazide, maleic acid dihydrazide, fumarate, etc. Examples thereof include unsaturated dihydrazides such as acid dihydrazide, itaconic acid dihydrazide and phthalic acid dihydrazide, carbonic acid dihydrazide, carbodihydrazide, and thiocarbodihydrazide. As glycols, they can be appropriately selected from the aforementioned polyols.

  As commercially available polyurethane resins, water-based ones suitable for the present invention include Takelac series (W-615, W-6010, W-511, etc.) manufactured by Mitsui Takeda, and Adeka Bon titer series manufactured by Asahi Denka Kogyo Co., Ltd. (HUX-232, HUX-320, HUX-380, HUX-401 etc.), Superflex series (500, 550, 610, 650 etc.) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Hydran manufactured by Dainippon Ink & Chemicals, Inc. Series (HW-311, HW-350, HW-150 etc.) etc. are mentioned.

  In the aqueous primer composition of the present invention, it is particularly important to use the epoxy compound (B) and the isocyanate compound (C) in combination with the urethane resin (A), and any of (B) and (C) Even if lacking components, UV ink adhesion and scratch resistance cannot be obtained.

  Examples of the epoxy compound (B) include bisphenol A diglycidyl ether, bisphenol A β-dimethylglycidyl ether, bisphenol F diglycidyl ether, tetrahydroxyphenylmethane tetraglycidyl ether, resorcinol diglycidyl ether, brominated bisphenol A diglycidyl ether, Chlorinated bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide adduct, novolac glycidyl ether, polyalkylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol diglycidyl ether, epoxy Glycidyl ether type such as urethane resin; p-oxy Glycidyl ether / ester type such as glycidyl ether / ester of benzoic acid; diglycidyl phthalate, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, acrylic acid diglycidyl ester, dimer acid diglycidyl ester, etc. Glycidyl ester type; Glycidylamine type such as glycidyl aniline, tetraglycidyl diaminodiphenylmethane, triglycidyl isocyanurate, triglycidyl aminophenol; Linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil; 3,4-epoxy- 6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) Alicyclic epoxy resins such as ruxoxylate, bis (3,4-epoxy-6methylcyclohexylmethyl) adipate, vinylcyclohexene diepoxide, dicyclopentadiene oxide, bis (2,3-epoxycyclopentyl) ether, limonene dioxide, etc. Can be mentioned. Among these, it is preferable to use an epoxy resin having two or more epoxy groups in the molecule from the viewpoints of transparency of the coating film, ink adhesion, UV ink adhesion, scratch resistance, and the like.

  The content of the epoxy compound (B) needs to be 10 to 60 parts by mass with respect to 100 parts by mass of the polyurethane resin (A), and is preferably 10 to 50 parts by mass from the viewpoint of blocking resistance and adhesiveness. 10 to 40 parts by mass is more preferable, 10 to 30 parts by mass is further preferable, and 10 to 20 parts by mass is particularly preferable. When the content of the fatty acid amide (B) is less than 10 parts by mass, the effect of improving the scratch property and UV ink adhesion is small, and when it exceeds 60 parts by mass, the suitability of the adhesive tends to decrease. .

  As commercially available epoxy compounds, water-based compounds suitable for the present invention include, for example, Nagase Chemtech's Denacol series (EM-150, EM-101, etc.), Asahi Denka Kogyo's Adeka Resin series, etc. Adeka Resins EM-0517, EM-0526, EM-11-50B, and EM-051R manufactured by Asahi Denka Co., Ltd., which are polyfunctional epoxy resin emulsions, are preferable from the viewpoint of improving UV ink adhesion and scratch resistance.

  Examples of the isocyanate compound (C) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane 2,4′- or 4,4′-diisocyanate, polymethylene polyphenyl diisocyanate, tolidine diisocyanate, 1 , 4-diisocyanatobutane, hexamethylene diisocyanate, 1,5-diisocyanato-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, , 10-diisocyanatodecane, 1,3- or 1,4-diisocyanatocyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 4,4'-diisocyanato Dicyclohexylmethane, hexahydrotoluene 2,4- or 2 6-diisocyanate, perhydro-2,4'- or 4,4'-diphenylmethane diisocyanate, naphthalene-1,5-diisocyanate, xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate And polyfunctional isocyanates obtained as their modified products. In particular, low-temperature treatment improves ink adhesion, scratch resistance, solvent resistance, and other performances, so there are two non-blocking polyfunctional isocyanate compounds, that is, two non-blocking isocyanate groups in one molecule. The compound contained above is preferable. Here, “non-block type” means that the isocyanate group is not blocked (sometimes referred to as “protection” or “mask”) by a lactam-based or oxime-based compound (so-called blocking agent). The modified product is a functional group derived from an isocyanate such as an allophanate group, a burette group, a carbodiimide group, a uretonimine group, a uretdione group, an isocyanurate group by modifying the isocyanate compound as described above by a known method. And a compound modified with a polyfunctional isocyanate compound in the molecule and an adduct type polyfunctional isocyanate compound modified with a polyfunctional alcohol such as trimethylolpropane. Among these, it is particularly preferable to use a polyfunctional isocyanate compound having an isocyanurate group from the viewpoint of improving ink adhesion, solvent resistance of the resin coating film, and scratch resistance. The polyfunctional isocyanate compound may contain monoisocyanate within a range of 20% by mass or less. Among the polyfunctional isocyanate compounds described above, it is preferable to use a modified product composed of hexamethylene diisocyanate in terms of improving boil resistance, retort resistance, and solvent resistance of the resin coating film, and among them, isocyanurate groups are particularly preferred. Those having the following are preferred.

  Among the non-blocking polyfunctional isocyanate compounds, aqueous (water-soluble or water-dispersible) compounds are preferable. Moreover, a preferable aqueous polyfunctional isocyanate compound can be obtained by reacting a polyfunctional isocyanate compound with a monovalent or polyvalent nonionic polyalkylene ether alcohol. Commercially available products of such water-based polyfunctional isocyanate compounds include BASONAT PLR 8878 and BASONAT HW-100 manufactured by BASF, Bayhydur 3100 manufactured by Sumitomo Bayer Urethane Co., Ltd., Bayhjur VPLS2150 / 1, SBU, and the like. Isocyanate L801, Desmodur N3400, Desmodule VPLS2102, Desmodule VPLS2025 / 1, SBU Isocyanate 0772, Desmodule DN, Takenate WD720, Takenate WD725, Takenate WD730, etc., Asahi Kasei Corporation Made Duranate WB40-100, Duranate WB40-80D, Duranate WX-1741, Nippon Polyure There is a down Co. roller sulfonate series, and the like. Among these, Bihydur 3100, Desmodur DN, and Vasonate HW-100, which are modified products of hexamethylene diisocyanate, are particularly preferable.

  The content of the isocyanate compound (C) needs to be 10 to 100 parts by mass with respect to 100 parts by mass of the polyurethane resin (A), and is preferably 10 to 90 parts by mass from the viewpoint of blocking resistance and adhesiveness. 20-80 mass parts is more preferable, 30-70 mass parts is still more preferable, and 40-70 mass is especially preferable. When the content of the isocyanate compound (C) is less than 10 parts by mass, the effect of improving the scratch property and UV ink adhesion is small, and when it exceeds 60 parts by mass, the suitability of the adhesive tends to decrease. .

  The aqueous primer composition of the present invention may contain a hydrophilic organic solvent in addition to water. Examples of such organic solvents include ketones such as methyl ethyl ketone, acetone and diethyl ketone, alcohols such as isopropanol, normal propanol, butanol, methanol and ethanol, cyclic ethers such as tetrahydrofuran and dioxane, ethylene glycol mono There are glycol derivatives such as butyl ether. Of these, isopropanol and normal propanol are preferable. The amount of these organic solvents in the total amount of the solvent is preferably 50% by mass or less, more preferably 30% by mass or less, and most preferably 5% by mass or less.

  As a method for producing the aqueous primer composition of the present invention, if the polyurethane resin (A), the epoxy compound (B) and the isocyanate compound (C) are uniformly mixed in an aqueous medium and then dispersed, Although not particularly limited, the aqueous dispersion of the polyurethane resin (A), the aqueous dispersion of the epoxy compound (B), and the aqueous dispersion of the isocyanate compound (C) prepared in advance are mixed, Furthermore, an aqueous primer composition having a desired component ratio can be easily prepared by adding water or a hydrophilic solvent as required.

  The dispersed particle diameter of the solid content in the aqueous primer composition of the present invention is not particularly limited, but the number average particle diameter is preferably in the range of 0.3 to 0.005 μm, and for reasons of transparency, 0.1 to 0. A range of 0.005 μm is more preferable. The weight average particle diameter is not particularly limited.

  The aqueous primer composition of the present invention includes an aqueous wax dispersion, an aqueous polyester dispersion, an aqueous polyolefin dispersion, an aqueous modified butadiene dispersion, an aqueous polylactic acid dispersion, polyvinyl alcohol, and an aqueous fatty acid amide dispersion, depending on the purpose. In addition, additives such as tin oxide and silica can be appropriately blended.

  As a substrate to which the water-based primer composition of the present invention can be applied, paper, synthetic paper, thermoplastic resin film, plastic product, steel sheet, metal foil such as aluminum foil, wood, woven fabric, knitted fabric, non-woven fabric, gypsum board, A wood board etc. are mentioned, It can be used by coating or impregnating. Especially, it is preferable to use for a thermoplastic resin film.

  Examples of the thermoplastic resin film include polyethylene terephthalate (hereinafter referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate and other polyester resins, polyglycolic acid, polylactic acid, etc. Biodegradable resins typified by aliphatic polyester resins such as polyhydroxycarboxylic acid, polyethylene succinate, polybutylene succinate, polyamide resins such as nylon 6, nylon 66, nylon 46, polypyropylene, polyethylene, ethylene-vinyl acetate Examples include films made of thermoplastic resins such as polyolefin resins such as copolymers, polyvinyl chloride, polyimide resins, polyarylate resins, or mixtures thereof, and laminates thereof. That is, inter alia, polyester resin, polyamide resin, polyethylene, ethylene - vinyl acetate copolymer, consisting of polypropylene film can be suitably used. These base films may be unstretched films or stretched films, and the production method is not limited. Moreover, although the thickness of a base film is not specifically limited, Usually, what is necessary is just to be the range of 1-500 micrometers.

  The method for applying the aqueous primer composition of the present invention to a substrate is not particularly limited, but gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, Dip coating, brush coating, etc. can be employed. Furthermore, you may perform what is called in-line coating which apply | coats the water-system primer composition of this invention to an unstretched film, and extends | stretches the coat film. What is necessary is just to select suitably the application quantity of a water-system primer with a base material.

  The drying temperature of the aqueous primer composition of the present invention is not particularly limited, and may be appropriately selected depending on the heat-resistant temperature of the substrate. Usually, it can be satisfactorily dried in a wide range of room temperature (around 25 ° C.) to 150 ° C. 50-100 degreeC is more preferable and 60-90 degreeC is further more preferable. When the drying temperature is lower than room temperature, the volatilization of the aqueous medium becomes insufficient and the ink adhesion may be lowered. Further, the time required for drying varies depending on the applied temperature, but if it is about 60 to 90 ° C., it can usually be dried in an extremely short time of about 30 seconds to 3 minutes.

  The solid content concentration of the water-based primer composition of the present invention is appropriately selected depending on the use and the like, and can be used in the range of 1 to 50% by mass. However, from the viewpoint of drying efficiency and workability, 2 to A range of 30% by mass is preferred.

The coating amount of the coating film formed using the aqueous primer composition of the present invention is appropriately selected depending on the application, but is preferably 0.005 to 5 g / m ^{2, and} is preferably 0.005 to 3 g / m ² is more preferable, 0.005 to ¹ g / m ² is more preferable, and 0.005 to 0.5 g / m ² is particularly preferable. If the thickness of the resin coating film is less than 0.005 g / m ² , the UV ink adhesion deteriorates. Moreover, when it exceeds 5 g / cm < ² >, it exists in the tendency for scratch resistance to deteriorate.

  The laminated body thus obtained is used for applications such as assemblies such as clear cases and clear boxes; packaging materials; magnetic recording materials such as magnetic tapes and magnetic disks; electronic materials; graphic films; It is particularly suitable for assemblies such as clear cases and clear boxes. As a method for forming an assembly, for example, a laminated body in the form of a film or sheet is creased into a box shape and formed into a box shape using a cyanoacrylate or hot melt adhesive. The laminate obtained by laminating the water-based primer composition of the present invention has good adhesive suitability for cyanoacrylate and hot melt adhesives. Furthermore, since the laminated body of the present invention has high transparency, it is possible to visually recognize the product as the contents if the product in the box is put in and displayed.

  In addition, various paints and inks can be used after applying the aqueous primer composition of the present invention. Examples thereof include water-based inks, water-based inks, solvent inks, and UV inks. UV ink is an ink that, when irradiated with ultraviolet rays, the photoinitiator in the UV ink absorbs the ultraviolet rays to generate radicals that are instantly cured by the polymerization reaction of reactive monomers and oligomers to form a coating film. It is. Examples of the ultraviolet light source for curing the UV ink include a metal halide lamp and a high-pressure mercury lamp. Commercially available UV inks can be used, for example, general UV inks manufactured by T & K TOKA, special UV inks, UV OP varnishes, Reicure CPO 6300 series (4100, 4200, 6100, 6200, etc.) manufactured by Jujo Chemical Co., Ltd. ), Toyo Ink's FD series (FD FL, FD New, FD TC OP Varnish VC, etc.), Seiko Advance's US series (UV HUG, UV ULA, etc.), Teikoku Ink's UV series (FIL, EXA, PAL, ESE, PAC, OPT, POL, etc.). Water-based ink, water-based ink, and solvent ink are inks that are dried with hot air to form a coating film. Commercially available products include, for example, Marine Plus SK manufactured by Dainippon Ink Co., Ltd. (Ultima NT, Snack Viewer, etc.), PANNECO AM manufactured by Toyo Ink Co., Ltd. (PANN Color S, SS16-000, Akwaking HN, etc.) Aqua PAW (POS, VS, EG) manufactured by the company can be mentioned.

  Among the various inks described above, the UV ink is particularly suitable because it has better adhesion to the coating film obtained from the aqueous primer composition of the present invention than other inks.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Various characteristics were measured or evaluated by the following methods.

1. Average particle diameter of solid content in primer composition The number average particle diameter was determined using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. Here, the refractive index used for particle diameter calculation was set to 1.50.

2. Characteristics of coating film In the following evaluation, as a thermoplastic resin film, a biaxially stretched PET film (Embret PET12 manufactured by Unitika, thickness 12 μm), a vinyl chloride base material (Tatsuta Dragons Belfan FE-33PHP, thickness 200 μm) A stretched PP film (manufactured by Tosero Co., Ltd., thickness 20 μm) was used.

(1) Adhesiveness of coating film The water-based primer of the present invention was coated on the corona-treated surface of various thermoplastic resin films using a Meyer bar, and then dried at 60 ° C for 1 minute. The coating amount was 1.0 g / m ² . The obtained coated film was evaluated after standing at room temperature for 1 day. Cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was applied to the coated surface, and the degree of peeling when the tape was peeled off at a stretch was visually evaluated.
○: No peeling at all, Δ: Partial peeling off, ×: All peeling off

(2) UV ink adhesion evaluation: Tape peeling test After coating the water-based primer composition on the corona-treated surface of various thermoplastic resin films using a Mayer bar, it was dried at 60 ° C. for 1 minute to apply a coating film. A coated film having an amount of 0.2 g / m ² was obtained. The obtained coated film was allowed to stand at room temperature for 1 day, and then applied with UV ink to a thickness of 10 μm, passed through a UV irradiation device under the condition of an integrated light amount of 500 mJ / cm ² , and cured with UV ink (manufactured by Jujo Chemical Co.) And used for the test. Evaluation was performed using the JIS-K5400 X cut tape method. A score of 7 or more out of 10 was considered acceptable.

(3) Transparency According to JIS K7105, it measured using NDH2000 "turbidity, haze meter" by Nippon Denshoku Industries Co., Ltd.

(4) Scratch resistance The corona-treated surface of various thermoplastic resin films was coated with a water-based primer composition using a Mayer bar and dried at 60 ° C. for 1 minute. The coating amount of the coating film was 0.2 g / m ² . The obtained coated film was allowed to stand at room temperature for 7 days and then evaluated by the JIS-K5400 pencil scratch value tester method. As an evaluation method, the pencil scratch value test was performed five times, and the following evaluation was performed based on the number of scratches.
○: No scratch.
Δ: There are scratches once or twice.
X: There are scratches 3 times or more.

(5) Adhesive suitability The corona-treated surface of various thermoplastic resin films was coated with a water-based primer composition using a Mayer bar and dried at 60 ° C. for 1 minute. The coating amount of the coating film was 0.2 g / m ² . The resulting coated film was left at room temperature for 7 days. After leaving for 7 days, two pieces were cut into 15 cm squares, and a cyanoacrylate instant adhesive (manufactured by Toa Gosei Co., Ltd.) was applied to a width of 2.0 mm and a length of 4.0 cm on the coated surface and peeled by hand 10 minutes later.
○: Most of the bonded surface of the film was not peeled and the substrate was destroyed.
(Triangle | delta): The bonding surface of the film peeled to half and the base material was destroyed.
X: All the bonding surfaces of the film were peeled off.

(6) Blocking resistance After a primer composition is coated on an aluminum foil (Mitsubishi Aluminum Co., Ltd., thickness 15 μm) with a Mayer bar, it is dried at 90 ° C. for 120 seconds, and a coating amount is 0.2 g / m ² . Got the body. With the aluminum foil overlapped on the coated surface of the laminate, a load of 0.1 MPa was applied, and after standing for 24 hours in an atmosphere of 30 ° C. and 65% RH, the aluminum foil was lifted and evaluated by the peeled state at that time did.
○: The aluminum foil is peeled off by gently lifting it.
(Triangle | delta): It peels by pulling aluminum foil.
X: The aluminum foil is broken, or the interface or cohesive peeling of the coating film is observed.

Details of each raw material used are as follows.
1. Polyurethane resin aqueous dispersion (1) Takelac W-6010 (Tg: 90 ° C. Average particle size: 0.06 μm Solid content concentration: 30% by mass, manufactured by Mitsui Takeda Chemical Co., Ltd., hereinafter referred to as W-6010)
(2) Superflex 550 (Tg: −15 ° C. Average particle size: 0.13 μm Solid content concentration: 45% by mass, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., hereinafter 550)

2. Epoxy compound aqueous dispersion (1) Denacol EM-150 (epoxy equivalent: 450 g / eq, solid content concentration: 50% by mass, manufactured by Nagase Chemtech, EM-150 hereinafter)
(2) Adeka Resin EM-101-50 (epoxy equivalent 1000 g / eq solid content concentration: 50% by mass, manufactured by Adeka, hereinafter EM-101-50)

3. Isocyanate compound (1) Bihijoule 3100 (solid content concentration: 100% by mass, isocyanate group content: 17.2% by mass, manufactured by Sumitomo Bayer, Inc., hereinafter 3100)
(2) Basonate HW-100 (solid content concentration: 100% by mass, isocyanate group content: 17.5% by mass, manufactured by BASF, hereinafter HW-100)

Example 1
Polyurethane resin aqueous dispersion W-6010 stock solution, epoxy compound aqueous dispersion EM-150 in water dilution (solid content concentration 25% by mass) and isocyanate compound aqueous dispersion 3100 in water dilution (solid content concentration 10% by mass) Were mixed and stirred at room temperature using a mechanical stirrer so that the mass ratio was 50/6/15, and a liquid having a solid content mass ratio of polyurethane resin, epoxy compound, and isocyanate compound of 100/10/10 was obtained. . The solid content concentration of this liquid was 25.4% by mass. Next, this liquid was diluted with a mixed solvent of water / isopropanol (mass ratio 1/3) and adjusted so as to have a solid content concentration of 2.0% by mass to obtain a primer composition J-1. Table 1 shows the performance evaluation results of the coating film using this.

Examples 2-9
Except that the mixing ratio of the raw materials was changed so that the mass ratio of each solid content of the polyurethane resin, the epoxy compound, and the isocyanate compound became the mass ratio shown in Table 1, the same operation as in Example 1 was performed to obtain a solid content concentration of 2. 0 mass% of primer compositions J-2 to J-9 were obtained. Table 1 shows the performance evaluation results of the coating films using these.

Examples 10-13
As shown in Table 2, a primer composition having a solid content concentration of 2.0% by mass was carried out in the same manner as in Example 1 except that the types of polyurethane resin aqueous dispersion, epoxy compound aqueous dispersion and isocyanate compound were changed. J-10 to J-13 were obtained. Table 2 shows the performance evaluation results of the coating films using these.

Examples 14-15
Using the primer composition J-2 prepared in Example 2, the coating amounts on various thermoplastic resin films were evaluated as 1.0 g / m ² and 6.0 g / m ² . The evaluation results are shown in Table 2.

Comparative Example 1
A polyurethane resin aqueous dispersion W-6010 diluted with water to a solid content concentration of 2.0% by mass was used. Table 3 shows the performance evaluation results of the coating film using this.

Comparative Example 2
The aqueous polyurethane resin dispersion W-6010 and the aqueous epoxy compound dispersion EM-150 were mixed and stirred at room temperature using a mechanical stirrer so that the mass ratio of the polyurethane resin and the epoxy compound was 100/10. Dilution was performed to obtain a primer composition H-2 having a solid concentration of 2.0% by mass. Table 3 shows the performance evaluation results of the coating film using this.

Comparative Example 3
The polyurethane resin aqueous dispersion W-6010 and the isocyanate compound aqueous dispersion 3100 were mixed and stirred at room temperature using a mechanical stirrer so that the solid content mass ratio of the polyurethane resin and the isocyanate compound would be 100/50, and water. To obtain a primer composition H-3 having a solid content concentration of 2.0% by mass. Table 3 shows the performance evaluation results of the coating film using this.

Comparative Examples 4-5
As shown in Table 3, the solid content concentration was obtained by performing the same operation as in Example 1 except that the mixing ratio of the polyurethane resin aqueous dispersion W-6010, the epoxy compound aqueous dispersion EM-150, and the isocyanate compound 3100 was changed. 2.0 mass% primer compositions H-4 and H-5 were obtained. Table 3 shows the performance evaluation results of the coating film using this.

In Examples 1-13, it was excellent in coating-film adhesiveness, UV ink adhesiveness, transparency, scratch resistance, and adhesive suitability irrespective of the kind of base film and aqueous dispersion. In Examples 14 to 15 in which the coating amount was increased, all of the coating film adhesion, UV ink adhesion, and transparency were good. In Example 14, adhesive suitability was slightly lowered, and in Example 15, scratchability and adhesive suitability were slightly lowered, but both were in a range where there was no practical problem.

  On the other hand, since the comparative example 1 used the urethane resin independently, it was inferior to UV ink adhesiveness, transparency, scratch resistance, and adhesive suitability. Since the isocyanate compound was not added, the comparative example 2 was inferior to UV ink adhesiveness and scratch resistance. Since the epoxy compound aqueous dispersion was not added, the comparative example 3 was inferior to UV ink adhesiveness and scratch resistance. In Comparative Example 4, since the mass ratio of the epoxy compound and the isocyanate compound was low with respect to the polyurethane resin, the UV ink adhesion and scratch resistance were poor. In Comparative Example 5, since the mass ratio of the epoxy compound and the isocyanate compound was high with respect to the polyurethane resin, the UV ink adhesion and adhesive suitability were poor.

In all Examples and Comparative Examples, the blocking resistance was good and the evaluation was “◯”.

Claims (6)

An aqueous primer composition containing 100 parts by mass of the polyurethane resin (A), 3 to 60 parts by mass of the epoxy compound (B), and 10 to 100 parts by mass of the isocyanate compound (C). The water-based primer composition according to claim 1, which is used for ultraviolet curable ink. The laminated body formed by forming the coating film obtained from the water-system primer composition of Claim 1 or 2 on a thermoplastic resin base material. The laminate according to claim 3, wherein the coating amount of the coating film is 0.005 to 5 g / m ² . A laminate in which the coating surface of the laminate according to claim 3 or 4 is printed with ultraviolet curable ink. The clear case or clear box formed from the laminated body in any one of Claims 3-5.