Hard coat film, method for producing molded article using same, molded article, and molded film

Abstract

To provide a hard coat film having good moldability at low temperature and excellent flexibility at normal temperature and suitable for film molding, a method for producing a molded article using the same, a molded article and a molded film.SOLUTION: The hard coat film has a cured layer of a photocurable resin composition on a plastic substrate, wherein the photocurable resin composition contains a urethane acrylate obtained by further reacting pentaerythritol triacrylate with a diisocyanate obtained by reacting (poly) ethylene glycol with isophorone diisocyanate, a leveling agent, and a photopolymerization initiator, and the plastic substrate is an olefin-based substrate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hard-coated film having excellent formability, and further to a method for producing a molded article using the same, the molded article, and a molded film. [Background technology]

[0002] Conventionally, spray painting has been the standard method for coloring automotive exterior parts, such as fenders, bumpers, and hoods. However, this method requires repeated painting and drying, which requires large equipment, space, and labor. It also consumes a huge amount of energy, and when the paint is solvent-based, evaporation increases the environmental impact, posing many problems.

[0003] To address these issues, there is a film molding method that uses pre-colored decorative film. Compared to methods using paints such as spray painting, this method allows for greater design freedom, makes it easy to decorate surfaces with three-dimensional irregularities, and is widely adopted for its excellent productivity. Well-known examples include insert molding, in which a design is printed on the film surface, which is then heated to soften it and subjected to three-dimensional molding, after which it is set in a mold and injection molded, and TOM molding, which involves vacuum and pressure molding on a pre-formed substrate.

[0004] Formed films used in these molding methods typically have a hard coat (hereinafter referred to as HC) layer to improve surface hardness and scratch resistance. However, if the HC resin layer is made too hard, microcracks will occur on the curved surface when the film is processed into a three-dimensional shape, making molding difficult. For this reason, the applicant previously invented a hard coat agent containing a triazine ring-containing (meth)acrylate prepolymer and organic fine particles with an average primary particle size of 80 to 500 nm (Patent Document 1). This composition was an excellent HC agent that had a film thickness of 1 to 10 μm and was capable of achieving both sufficient flexibility and surface properties.

[0005] By selecting the right HC agent for these molding applications, processing constraints have been alleviated to some extent. However, as the applications of film molding expand, new technical challenges and required properties have emerged. For example, in the case of large-size insert molding, chipping and cracking can occur during the process from preforming to setting in the injection molding mold, resulting in reduced yields. Furthermore, in TOM molding, when molding onto substrates with relatively low heat resistance, moldability at lower temperatures is sometimes required to minimize damage to the substrate. Therefore, there is a growing demand for moldable HC films that are easy to handle and flexible at room temperature, while also allowing molding at lower temperatures. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4848200 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to provide an HC film suitable for film molding applications, which has good scratch resistance, good formability at low temperatures, and excellent flexibility at room temperature, as well as a method for manufacturing a molded article using the same, a molded article, and a molded film. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the invention of claim 1 provides an HC film having a cured layer of a photocurable resin composition on a plastic substrate, wherein the photocurable resin composition contains urethane acrylate (A) obtained by further reacting pentaerythritol triacrylate with a diisocyanate obtained by reacting (poly)ethylene glycol with isophorone diisocyanate, a leveling agent (B), and a photopolymerization initiator (C), and the plastic substrate is an olefin-based substrate.

[0009] The invention of claim 2 provides the HC film according to claim 1, characterized in that the olefin-based film has a polypropylene base material.

[0010] The invention of claim 3 provides the HC film according to claim 1, characterized in that the photocurable resin composition further contains nanoalumina particles (D).

[0011] A fourth aspect of the present invention provides the HC film according to the first aspect, characterized in that the photocurable resin composition further contains a light stabilizer (E).

[0012] The invention of claim 5 provides a method for producing an insert-molded product, in which the HC film according to any one of claims 1 to 4 is shaped using a mold, and then molten resin is injected from the side opposite to the photocurable resin cured layer to form a resin molded product.

[0013] The invention of claim 6 provides an insert molded product or an out-molded product using the HC film of any one of claims 1 to 4.

[0014] The seventh aspect of the present invention provides a molded film characterized in that the HC film according to any one of the first to fourth aspects further comprises a decorative layer and / or a pressure-sensitive adhesive layer. [Effects of the Invention]

[0015] The HC film of the present invention has high breaking elongation and excellent scratch resistance, and also has good formability at low temperatures and excellent flexibility at room temperature, making it useful as an HC film for use in film molding such as insert molding and out-molding. BEST MODE FOR CARRYING OUT THE INVENTION

[0016] The photocurable resin composition of the present invention comprises (A) a urethane acrylate (hereinafter referred to as urea) having a structure obtained by further reacting pentaerythritol triacrylate (hereinafter referred to as PETA) with a diisocyanate obtained by reacting (poly)ethylene glycol with isophorone diisocyanate (hereinafter referred to as IPDI), a leveling agent (B), and a photopolymerization initiator (C). Note that in this specification, "(meth)acrylate" includes both acrylate and methacrylate, and "(poly)ethylene glycol" includes both ethylene glycol and polyethylene glycol.

[0017] The alicyclic diisocyanate IPDI used in the synthesis of (A) is non-yellowing, has excellent weather resistance, and is highly rigid, allowing for increased hardness of the cured product. Furthermore, by reacting it with (poly)ethylene glycol, the ductility of the cured product can be improved, ensuring good moldability. Furthermore, the use of ethylene glycol, which has a very short carbon chain, allows for a higher concentration of urethane bonds within the molecule than when polyethylene glycol is used, resulting in the formation of a linear main skeleton with greater chemical resistance and higher rigidity.

[0018] The synthesis method for (A) is not particularly limited, and known methods can be used. The reaction can be carried out without a solvent. However, as the molecular weight of (A) increases, stirring can become difficult. Therefore, ketones such as MEK or aromatic inert solvents such as xylene can be used. Furthermore, it is preferable to use a catalyst for the reaction between the hydroxyl groups of (poly)ethylene glycol and PETA and the isocyanate groups. Examples of such a catalyst include tin-based catalysts such as dibutyltin dilaurate and metal alkoxide-based catalysts such as cobalt naphthenate. The reaction temperature can be set as appropriate, but is preferably 40 to 120°C, more preferably 60 to 100°C.

[0019] The weight-average molecular weight (hereinafter referred to as Mw) of (A) is preferably 2,000 to 12,000, more preferably 3,000 to 11,000, and particularly preferably 3,500 to 10,000. A weight-average molecular weight of 2,000 or more ensures high elongation at break and sufficient moldability, while a weight-average molecular weight of 12,000 or less ensures sufficient abrasion resistance and scratch resistance. When ethylene glycol is used, the Mw of (A) can be adjusted by the molar ratio of ethylene glycol to IPDI reacted; the closer the molar ratio of IPDI to ethylene glycol, the higher the Mw tends to be. The Mw was measured and calculated by gel permeation chromatography using a column packed with a styrene-divinylbenzene base material and a tetrahydrofuran eluent, relative to the molecular weight of standard polystyrene.

[0020] The blending amount of (A) is preferably 70 to 95% by weight, more preferably 75 to 93% by weight, and particularly preferably 80 to 92% by weight, based on the total solid content. By making it 70% by weight or more, sufficient moldability and flexibility can be ensured, and by making it 95% by weight or less, sufficient scratch resistance can be ensured.

[0021] The leveling agent (B) used in the present invention is blended to improve the leveling properties during coating and the scratch resistance of the cured coating. It preferably has a reactive functional group capable of polymerizing with the binder resin to form a cured coating film, since it will not bleed out of the cured coating over time and will maintain its weather resistance effect for a long period of time. Examples of such agents include fluorine-based, silicone-based, and fluorine-silicone-based agents, and these can be used alone or in combination of two or more.

[0022] Among these, silicone-based polysiloxane compounds are preferred because they can equalize large differences in surface tension on the coating surface. Examples include polyalkylsiloxanes, polyarylsiloxanes, polyalkylarylsiloxanes, polyester-modified siloxanes, and polyether-modified siloxanes, and these can be used alone or in combination of two or more.

[0023] The blending amount of (B) is preferably 0.1 to 3 wt % of the total solid content, and more preferably 0.3 to 2 wt %. By adjusting the blending amount to this range, sufficient leveling properties can be ensured and a stable coating film appearance can be obtained. Commercially available products include BYK-UV3570 (trade name: BYK Chemie, acryloyl group-containing polyester-modified polydimethylsiloxane compound).

[0024] The photopolymerization initiator (C) used in the present invention generates radicals upon irradiation with ultraviolet light or an electron beam, and these radicals trigger the polymerization reaction, and general-purpose photopolymerization initiators such as benzyl ketals, acetophenones, and phosphine oxides can be used. By arbitrarily selecting the light absorption wavelength of the polymerization initiator, it is possible to impart curability over a wide wavelength range from the ultraviolet region to the visible light region. Specifically, benzyl ketals include 2,2-dimethoxy-1,2-diphenylethan-1-one, α-hydroxyacetophenones include 1-hydroxy-cyclohexyl-phenyl-ketone and 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, α-aminoacetophenones include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and acylphosphine oxides include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and these can be used alone or in combination of two or more.

[0025] Among these, it is preferable to use an α-hydroxyacetophenone-based resin that is less prone to yellowing, and examples of commercially available products include Omnirad 127D, 184, and 2959 (trade names: manufactured by IGM Resins). The amount of (C) added per 100 parts by weight of the radically polymerizable component is preferably 2 to 15 parts by weight, more preferably 5 to 12 parts by weight.

[0026] The photocurable resin composition of the present invention (hereinafter referred to as the present composition) preferably further contains nano-alumina particles (D). (D) increases the hardness of the cured layer, improving abrasion resistance and, in particular, resistance to scratches caused by car washes and the like.

[0027] The average primary particle size of (D) is preferably 10 to 300 nm, more preferably 30 to 200 nm, particularly preferably 50 to 150 nm, and particularly preferably 70 to 100 nm. By making it 10 nm or more, car wash scratch resistance can be improved, and by making it 300 nm or less, good optical properties of the film can be ensured.

[0028] The blending amount of (D) is preferably 0.1 to 20.0 wt % of the total solid content of the resin composition, more preferably 0.5 to 15.0 wt %, and particularly preferably 1.0 to 10.0 wt %. By making it 0.1 wt % or more, it is expected that the car wash scratch resistance will be improved, and by making it 20.0 wt % or less, sufficient moldability will be ensured.

[0029] The composition preferably further contains a light stabilizer (E). The incorporation of (E) can reduce deterioration of the cured coating due to exposure to ultraviolet light and radiant heat when used outdoors. Examples of such stabilizers include radical scavengers (e1) that efficiently trap alkyl radicals and peroxy radicals generated from polymers photodegraded by ultraviolet light, and ultraviolet absorbers (e2) that convert absorbed ultraviolet energy into heat energy, thereby inhibiting polymer decomposition.

[0030] Examples of (e1) include hindered amines (hereinafter referred to as HALS), hindered phenols, and aromatic amines, which can be used alone or in combination of two or more. Among these, HALS is preferred because it has a high radical scavenging efficiency even at low concentrations. The amount of (e1) added is preferably 1 to 10% by weight, more preferably 2 to 8% by weight, and particularly preferably 3 to 6% by weight, based on the total solid content. By using this range, sufficient light stability can be ensured. Commercially available HALS products include Tinuvin 123 and Tinuvin 249 (trade names: manufactured by BASF Japan Ltd.).

[0031] (e2) is a radical chain initiation inhibitor with an absorption band in the high-energy, harmful ultraviolet region. When used in combination with (e1), it can further improve and stabilize weather resistance. Examples include benzotriazoles, triazines, and benzophenones, which can be used alone or in combination. Among these, hydroxyphenyltriazines, which are capable of strongly absorbing the long wavelength portion of ultraviolet light, are preferred. The blending amount of (e2) is preferably 0.3 to 5 wt. % of the total solid content, more preferably 0.5 to 3.0 wt. %, and particularly preferably 0.6 to 1.5 wt. This range ensures sufficient ultraviolet absorption characteristics. The blending amount of (E), the sum of (e1) and (e2), is preferably 1.0 to 12 wt. % of the total solid content, more preferably 1.5 to 10 wt. %, and particularly preferably 4.0 to 8.0 wt. %. By setting the content at 1.0% by weight or more, improved weather resistance can be expected, and by setting the content at 12% by weight or less, excessive blending is avoided and sufficient adhesion to the substrate can be ensured. Commercially available products include Tinuvin 460 and 477 (trade names: manufactured by BASF Japan Ltd.).

[0032] To the present composition, reactive diluents, adhesion promoters, bluing agents, pigments, antifoaming agents, thickeners, anti-suspending agents, antistatic agents, anti-fogging agents, antibacterial agents, waxes, matting agents, hydrophilic agents, water-repellent agents, inorganic fillers, organic fine particles, and the like may be added as needed, provided that the performance is not impaired.

[0033] As the reactive diluent, it is preferable to use a polyfunctional (meth)acrylate because it has low viscosity and excellent compatibility with (A). For example, bifunctional diluents include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and dicyclopentanyl diacrylate; trifunctional dimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; tetrafunctional ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, and diglycerin tetra(meth)acrylate; pentafunctional dipentaerythritol penta(meth)acrylate; and hexafunctional dipentaerythritol hexa(meth)acrylate. These diluents can be used alone or in combination of two or more.

[0034] The amount of the reactive diluent is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, per 100 parts by weight of (A). By using 20 parts by weight or less, it is possible to improve reactivity while ensuring sufficient moldability. The blending ratio relative to the total solid content is preferably 15% by weight or less, more preferably 10% by weight or less.

[0035] When applying the composition to a plastic substrate, it may be diluted with a solvent to improve coating properties. Examples of suitable solvents include alcohol-based solvents such as ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and diacetone alcohol; ketone-based solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as ethyl acetate and butyl acetate; ether-based solvents such as propylene glycol monomethyl ether (PGM), diethyl ether, and diisopropyl ether; and hydrocarbon-based solvents such as cyclohexane and methylcyclohexane. These solvents may be used alone or in combination. The solids content of the diluted composition is typically 10 to 70%, but there are no specific limitations and the viscosity can be adjusted appropriately to achieve a coating viscosity that is easy to apply.

[0036] The plastic substrate to which the composition is applied is an olefin-based substrate. Compared with other films such as acrylic, olefin-based substrates are substrates that have excellent flexibility even when thick. Examples include polyethylene, polypropylene, polybutene, polymethylpentene, polycycloolefin, and copolymers thereof. Among these, polypropylene is preferred because of its low heat resistance, oil resistance, and heat distortion temperature. Note that polypropylene refers to a polymer containing at least polypropylene, specifically homopolypropylene and copolymers with other olefins.

[0037] The polypropylene base material preferably does not contain a nucleating agent. A nucleating agent is an additive that promotes the crystallization of polymers. The addition of a nucleating agent shortens the induction period until crystal growth and can improve the crystallization rate of the polymer. On the other hand, if a nucleating agent is not added, there is no substance that can serve as a nucleus for crystals, which tends to further improve transparency. In addition, since crystallization proceeds slowly, the bond strength between molecules tends to be low, which ensures good flexibility and tends to allow for lower molding temperatures.

[0038] The polypropylene substrate may be subjected to a surface treatment to improve adhesion to the composition, such as a primer treatment, a sandblasting method, a solvent treatment, or other surface roughening treatment, or a surface oxidation treatment such as a corona discharge treatment, a chromic acid treatment, or an ozone / ultraviolet irradiation treatment.

[0039] The thickness of the polypropylene substrate is not particularly limited, and may be set appropriately depending on the application, for example, from 50 to 500 μm. Commercially available products include Pure Thermo AG-356AS (trade name: manufactured by Idemitsu Unitech Co., Ltd., 200 μm thick, polypropylene film containing no nucleating agent).

[0040] The method for applying the composition is not particularly limited, and the composition can be formed by known coating methods such as spray coating, roll coating, die coating, air knife coating, blade coating, spin coating, reverse coating, gravure coating, wire bar coating, etc., or printing methods such as gravure printing, screen printing, offset printing, inkjet printing, etc. The thickness of the coated film when dried can be, for example, 1 μm to 20 μm, but is not limited to this.

[0041] The light source of ultraviolet radiation used to cure this composition includes low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, LED lamps, and electrodeless ultraviolet lamps. The irradiation atmosphere may be air or an inert gas such as nitrogen or argon. Furthermore, the curing property can be further improved by heating the coating film during ultraviolet irradiation using a back roll or an IR heater. The irradiation conditions are an irradiation intensity of 500 mW / cm. 2 ~3000mW / cm 2 , exposure dose 50-400mJ / cm 2 are exemplified, but are not limited to these.

[0042] The HC film (hereinafter referred to as the present HC film) obtained by coating the present composition on a plastic substrate and curing it preferably has a breaking elongation of 50% or more, more preferably 100% or more, and particularly preferably 200% or more in an atmosphere of 130°C. By making the breaking elongation 50% or more, sufficient formability can be expected.

[0043] The present HC film may be provided with a decorative layer and an adhesive layer as necessary. A backing sheet layer may also be provided as a reinforcing layer. The arrangement of these layers relative to the substrate may be arbitrary, except that the HC layer is the uppermost layer. A laminate including a decorative layer other than the HC layer and / or an adhesive layer and / or a backing sheet layer will hereinafter be referred to as the present molded film.

[0044] Examples of the layer configuration of the present molded film include, but are not limited to, HC layer / substrate / decorative layer / adhesive layer, HC layer / decorative layer / substrate / adhesive layer, HC layer / substrate / decorative layer / backing sheet layer, HC layer / decorative layer / substrate / backing sheet layer, HC layer / substrate / adhesive layer / backing sheet layer, HC layer / decorative layer / substrate / adhesive layer / backing sheet layer, HC layer / substrate / decorative layer / adhesive layer / backing sheet layer, etc. Furthermore, a primer layer and an adhesive layer may be further disposed between each layer to improve adhesion.

[0045] The decorative layer can usually be formed using printing ink by a known printing method such as gravure printing, offset printing, silk screen printing, transfer printing, or ink jet printing. Examples of binders for printing ink include acrylic, polyester, urethane, and vinyl chloride-vinyl acetate copolymer binders, which can be used alone or in combination of two or more. In addition to these, appropriate mixtures of colorants such as pigments and dyes, stabilizers, plasticizers, curing agents, catalysts, and the like can also be used.

[0046] The colorant may be an inorganic pigment such as titanium white, red iron oxide, or ultramarine blue, an organic pigment such as Hansa Yellow A or phthalocyanine blue, a metal pigment such as aluminum or brass, a pearl pigment, or a fluorescent pigment, either alone or in combination of two or more.In addition, instead of printing ink, a film may be formed by a method such as vacuum deposition, sputtering, or electroless plating using a metal such as aluminum, indium, chromium, nickel, gold, or silver.

[0047] When printing ink is used, the thickness of the decorative layer is preferably 3 to 50 μm, more preferably 5 to 30 μm. By setting the thickness within this range, it is possible to improve hiding power and to fully express complex designs such as gradations.

[0048] The adhesive layer is typically a pressure-sensitive adhesive layer. The adhesive layer contains, for example, an acrylic, polyolefin, rubber, polyester, silicone, or polyurethane adhesive polymer. The adhesive polymer may be crosslinked with an isocyanate, epoxy, or metal chelate crosslinking agent. The adhesive layer may be thermosetting, thermoplastic, or photocurable. Among these, acrylic adhesives are preferred in terms of high transparency and weather resistance, and crosslinked acrylic adhesives are even more preferred. The adhesive layer may also contain a tackifier.

[0049] The adhesive layer can be formed by a known method using a gravure coater, a flexo coater, a roll coater, a knife coater, a comma coater, etc. Alternatively, a pressure-sensitive adhesive layer previously formed into a sheet shape may be laminated.

[0050] The thickness of the adhesive layer is preferably 10 to 100 μm, more preferably 20 to 80 μm, and particularly preferably 25 to 60 μm. A thickness of 10 μm or more can be expected to ensure good adhesion to the substrate, while a thickness of 100 μm or less can reduce protrusion from the film edge in a high-temperature environment and suppress a decrease in pencil hardness.

[0051] The backing sheet layer is arranged to provide strength during insert molding to facilitate handling during preforming, improve adhesion with the injection molding resin, suppress thermal damage during injection, and improve the hiding power of the substrate. Examples include polyethylene-based, polypropylene-based, polyester-based, polyurethane-based, polyvinyl chloride-based, and acrylonitrile butadiene styrene (hereinafter referred to as ABS-based). The backing sheet layer may be colored.

[0052] The heat distortion temperature (deflection temperature under load) of the backing sheet is preferably 85 to 120°C. By setting the heat distortion temperature to 85°C or higher, it is possible to sufficiently suppress deformation and distortion due to heat when drying the printing ink of the decorative layer, and by setting the heat distortion temperature to 120°C or lower, it is not necessary to raise the temperature when preforming the formed film, and variations in elongation and distortion during preforming can be sufficiently suppressed. Therefore, polypropylene (deflection temperature under load: 100°C), ABS-based materials (deflection temperature under load: 95°C), etc. are preferred as materials for the backing sheet.

[0053] A protective film may be attached to the molding film to protect the surface to which the composition is applied. By using a protective film, scratches can be prevented during insert molding or out-molding processes. Yield improvement can be expected.

[0054] The present molding film can be used in insert molding, for example, by placing the surface coated with the present composition facing the inner wall of the mold (so that the surface opposite the cured layer of the present composition is in contact with the molding resin), preforming the present HC film to the shape of the mold as needed, and then closing the mold to inject the molten molding resin into the cavity and solidifying the resin to form a resin molded product.

[0055] The preforming method may be a method in which the HC film is preheated to above its softening point and placed in a mold, followed by vacuum suction through suction holes in the mold, or a known molding method such as vacuum forming, compressed air forming, or press molding using a molding mold separate from the injection molding mold. It is also possible to simultaneously perform molding and integral molding of the injected resin by the injection pressure of the molding resin without performing these preforming methods.

[0056] The resin to be injection-molded can be any known resin that can be injection-molded. Examples include polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, acrylic resin, urethane resin, polyester resin, polycarbonate resin, polyphenylene ether resin, polyacetal resin, and polysulfone resin. These resins can be used alone or in combination of two or more. For large sizes, such as automobile bodies, or for small sizes with thin walls, warping and other problems can be avoided by approximating the shrinkage rate after molding to that of HC film. When insert-molding this molded film, the surface that adheres to the injected resin is preferably a backing sheet layer or an adhesive layer.

[0057] By using a molding HC film with a polypropylene base material and integrating the HC film base material with the injection molding resin, such as injection molding with polypropylene resin, it becomes possible to create a mono-material molded product. Molded products made of a mono-material are easy to recycle because there is no need to separate them by material when discarding them, and by preventing the mixing of materials when recycling, the quality of the recycled product can be improved.

[0058] Furthermore, this molded film can also be used for out-molding. For example, it can be used for TOM (Three-Dimensional Overlay Method) molding. TOM molding is a film molding method in which a pre-formed substrate is subjected to three-dimensional surface decoration using vacuum and pressure molding inside an airtight box. By using this molded film, it is possible to handle large three-dimensional products regardless of the substrate material. When using this molded film for TOM molding, it is preferable that the surface that comes into contact with the molded product is an adhesive layer.

[0059] The present invention will be described in detail below with reference to examples and comparative examples, but these are intended to be specific examples and are not intended to limit the scope of the present invention. Unless otherwise specified, measurements were carried out at a room temperature of 25°C and a relative humidity of 65%. The blend amounts are expressed in parts by weight as solid content. [Example]

[0060] Preparation of ureac 1 A four-neck flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 200 parts by weight of ethylene glycol, 825 parts by weight of IPDI (NCO group 37.5%), a catalyst, and MEK (50% solids). The mixture was stirred and reacted at 80°C for 6 hours. The reaction was terminated when the isocyanate group peak reached a predetermined level by infrared absorption analysis. Next, 438 parts by weight of PETA (hydroxyl value 120 mg KOH / g) was added and the mixture was stirred and reacted at 70°C for 6 hours. After confirming the disappearance of the isocyanate groups by infrared absorption analysis, the solids were adjusted to 50% with MEK to obtain 1, a hexafunctional urea with a molecular weight of 6,200.

[0061] Preparation of ureac 2 A four-neck flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer was charged with 200 parts by weight of ethylene glycol, 930 parts by weight of IPDI (NCO group 37.5%), a catalyst, and MEK (50% solids). The mixture was stirred and reacted at 80°C for 6 hours. The reaction was terminated when the isocyanate group peak reached a predetermined level by infrared absorption analysis. Next, 886 parts by weight of PETA (hydroxyl value 120 mg KOH / g) was added and the mixture was stirred and reacted at 70°C for 6 hours. After confirming the disappearance of the isocyanate groups by infrared absorption analysis, the solids were adjusted to 50% with MEK to obtain 2, a hexafunctional urea with a molecular weight of 3,200.

[0062] According to the above production method, Ureac 3, which has the same skeleton as Ureacs 1 and 2 but a different Mw, Ureac 4, which uses polyethylene glycol instead of ethylene glycol, and Ureac A, which does not have a (poly)ethylene glycol skeleton, were obtained. Ureac 3: PETA-IPDI-(ethylene glycol-IPDI)n-PETA backbone, 6 functional groups, solid content 50%, Mw 9,800 Ureac 4: PETA-IPDI-polyethylene glycol-IPDI-PETA backbone; 6 functional groups, solid content 50%, Mw 6,000 Ureac A: 2HEA-HDI allophanate-2HEA skeleton, Bifunctional, solid content 50%, Mw 3,600

[0063] Formulation examples 1~8 The Ureacs 1 to 4 prepared above were used as (A), BYK-UV3570 (trade name: BYK Chemie, an acryloyl group-containing polyester-modified polydimethylsiloxane compound) as (B), Omnirad2959 and 127D (trade names: IGM Resins) as (C), nanoalumina microparticles with an average particle size of 70 nm as (D), Tinuvin249 (trade name: BASF Japan) as (e1), Tinuvin477 (trade name: BASF Japan) as (e2), and the Ureacs A and DPHA as binders were stirred until uniformly dissolved and dispersed in the formulation shown in Table 1, and PGM was further added to make the solid content 30%, followed by dilution and stirring to obtain photocurable resin compositions of Formulation Examples 1 to 8.

[0064] Plastic substrate for evaluation As the plastic substrates, polypropylene, PET, polycarbonate (hereinafter referred to as PC), acrylic, and acrylic / PC composite substrates were used, as described below. Polypropylene: Pure Thermo AG-356AS (product name: Idemitsu Unitech Co., Ltd., 200 μm thick, polypropylene film without nucleating agent) PET: U403 (product name: Toray Industries, thickness 100 μm) PC: PC-1151 (product name: Teijin, thickness 200 μm) Acrylic: HBA007P (product name: Mitsubishi Chemical Corporation, thickness 75 μm) Acrylic / PC composite: Iupilon film DF02PUL (product name: manufactured by Mitsubishi Gas Chemical Company, thickness 125 μm and 254 μm)

[0065] Preparation of HC films for examples and comparative examples The photocurable resin compositions of Formulation Examples 1 to 8 were used as the HC resin, and the coating was applied to the plastic substrate for evaluation so that the dry film thickness was 3 μm. After drying in a thermostatic chamber at 80°C for 1 minute, the coating was exposed to a high-pressure mercury lamp with an output of 1300 mW / cm. 2 The HC film for evaluation was prepared by irradiating the acrylic / PC composite substrate with ultraviolet light so that the cumulative light amount was 200 mJ. For the acrylic / PC composite substrate, the coating was applied to the PMMA side.

[0066] Table 1 JPEG2026000494000001.jpg70135

[0067] The evaluation method was as follows.

[0068] Transparency: Haze was measured in accordance with JIS K7136 using a haze meter HAZE-GARDi manufactured by Byk-Gardner, with less than 10% being rated as good and 10% or more being rated as bad.

[0069] Chemical resistance: Sunscreen cream Neutrogena SPF45 (trade name: Johnson & Johnson) was applied to the cured film and left at 80°C for 24 hours, then returned to room temperature and wiped off, after which the surface was observed. ◎ indicates no traces of application, ◯ indicates traces, and × indicates peeling of the film.

[0070] Abrasion resistance: Using a friction tester FR-IBS manufactured by Suga Test Instruments, the resin composition coated surface of the hard coat film was rubbed with a friction element (diameter 16 mm) equipped with a test white cotton cloth (Kanakin No. 3) under a load of 9 N, and moved back and forth 100 mm at a speed of 1 reciprocation per second. After 100 reciprocations, the presence or absence of scratches was checked, with a circle representing no scratches and an x ​​representing scratches.

[0071] Adhesion: In accordance with the cross-cut method of JIS K 5600-5-6, a 10 x 10 grid was created on the coated surface at 1 mm intervals, and cellophane tape CT-24 (trade name: manufactured by Nichiban Co., Ltd.) was applied and pulled upward to check for peeling, with a ◯ indicating no peeling and an × indicating peeling. No peeling: 100 / 100, Peeling: 0 / 100~99 / 100

[0072] Formability: The HC film was cut into a size of 25 mm wide x 110 mm long, and a tensile test was performed using a TechnoGraph TGI-1KN manufactured by Minebea Co., Ltd., with a chuck distance of 50 mm, an atmospheric temperature of 130°C, and a pulling speed of 300 mm / min. Cracks in the HC layer were visually confirmed, and the elongation was evaluated as follows: less than 50% was evaluated as ×, 50% to 100% as △, over 100% to 200% as 〇, and over 200% as ◎. Calculation formula: Calculate how many mm it has stretched based on 50 mm. Stretched length (mm) / 50mm x 100 = stretch rate %

[0073] Scratch resistance: Using a Toyo Seiki abrasion tester, the contact area is 4cm 2 A 500g load was placed on the #0000 steel wool and the test was repeated 10 times at a speed of 30 times per minute. The haze before and after the test was then measured in accordance with JIS K7136 using a BYK-Gardner haze meter, HAZE-GARDi. A haze increase of 5% or more was marked x, 5-1% was marked o, and less than 1% was marked ⊚.

[0074] Molding temperature: Using a TOM molding machine NGF-T-0203 manufactured by Fuse Vacuum Co., Ltd., the hard-coated film was heated and then vacuum-pressure molded using a cylindrical mold with a diameter of 30 mm and height of 20 mm at a pressure of 300 kPa for 15 seconds. The temperature at which the film could be completely molded was defined as the molding temperature for that film. Evaluation was based on the following criteria: less than 125°C: ◎; 125-150°C: 〇; and over 150°C or unmoldable: ×.

[0075] Flexibility: Using a BYK-Gardner cylindrical mandrel tester CAT-No. 5710, a test film sample of 120mm x 30mm was bent 180 degrees and the diameter at which no cracks occurred was measured. The evaluation method was as follows: with the HC surface facing outward (folded outward), if the R was 4mm or less it was rated as good, if it was 5mm to 7mm it was rated as fair, and if it was 8mm or more it was rated as bad.

[0076] Example evaluation results Table 2 JPEG2026000494000002.jpg128158

[0077] Comparative Example Evaluation Results Table 3 JPEG2026000494000003.jpg117164

[0078] The examples were satisfactory with no problems in all respects including transparency, chemical resistance, abrasion resistance, adhesion, moldability, scratch resistance, molding temperature, and flexibility.

[0079] On the other hand, even when a polypropylene substrate was used, Comparative Example 1, in which the HC resin binder was ureac A, which does not have a (poly)ethylene glycol skeleton, and Comparative Example 2, in which DPHA was used, had poor moldability and could not be molded, and Comparative Example 2 in particular had poor flexibility. Comparative Example 3, which used a PET substrate, had poor moldability and molding temperature, and Comparative Example 4, which used a PC substrate, had a high molding temperature and insufficient flexibility. Furthermore, Comparative Example 5, which used an acrylic substrate, had poor flexibility, and Comparative Examples 6 and 7, which used acrylic / PC composite substrates, had high molding temperatures and their flexibility decreased as the thickness increased, and neither was suitable for the present invention.

Claims

1. A hard coat film having a cured layer of a photocurable resin composition on a plastic substrate, the photocurable resin composition comprising: a urethane acrylate (A) obtained by further reacting pentaerythritol triacrylate with a diisocyanate obtained by reacting (poly)ethylene glycol with isophorone diisocyanate; a leveling agent (B); and a photopolymerization initiator (C); A hard coat film, wherein the plastic substrate is an olefin-based substrate.

2. 2. The hard coat film according to claim 1, wherein the olefin-based film has a polypropylene substrate.

3. 2. The hard coat film according to claim 1, wherein the photocurable resin composition further contains nanoalumina particles (D).

4. 2. The hard coat film according to claim 1, wherein the photocurable resin composition further contains a light stabilizer (E).

5. A method for producing an insert-molded article, comprising shaping the hard coat film according to any one of claims 1 to 4 using a mold, and then injecting a molten resin from the side opposite to the photocurable resin cured layer to form a resin molded article.

6. An insert-molded or out-molded product using the hard coat film according to any one of claims 1 to 4.

7. A molded film comprising the hard coat film according to any one of claims 1 to 4, further comprising a decorative layer and / or a pressure-sensitive adhesive layer.

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