Hard coat film, method for manufacturing molded article using the same, molded article, and molded film

Abstract

Provided are a hard coat film suitable for film forming applications that has good formability at low temperatures and excellent flexibility at room temperature, a method for manufacturing a molded article using the same, a molded article, and a formed film. 【Solution means】A hard coat film having a cured layer of a photocurable resin composition on a polypropylene substrate, wherein the elongation at break in tension of the hard coat film at 130 °C is 50 to 400%, and the polypropylene substrate does not contain a nucleating agent. The hard coat film is characterized by this.

Description

Technical Field

[0001] The present invention relates to a hard coat film having excellent formability, and further to a method for manufacturing a molded article using the same, a molded article, and a formed film.

Background Art

[0002] Conventionally, when coloring exterior parts of an automobile, such as fenders, bumpers, and bonnets, a method using spray painting has been generally used. On the other hand, since this method involves repeating painting and drying, large equipment, space, and a large number of man-hours are required. In addition, it consumes a huge amount of energy, and further, when the paint is a solvent-based paint, there are many problems such as an increased environmental load due to its volatilization.

[0003] In response to such problems, there is a film forming method using a pre-colored decorative film. This method can increase the degree of freedom in design compared to the case of using a paint such as spray painting, and it is also easy to decorate a surface having a three-dimensional uneven shape, and is widely adopted because of its excellent productivity. For example, insert molding in which a pattern is printed on the film surface and then three-dimensional molding is performed in a softened state by heating, and then injection molding is performed by setting it in a mold, and TOM molding in which vacuum or compressed air molding is performed on a pre-formed base material are well known.

[0004] For the forming film used in these forming methods, a hard coat (hereinafter referred to as HC) layer is generally provided for the purpose of improving the surface hardness and scratch resistance. However, when the HC resin layer is hardened, there is a problem that microcracks occur on the curved surface during processing into a three-dimensional shape, making molding difficult. Therefore, in the past, the applicant invented a hard coat agent containing a triazine ring-containing (meth) acrylate prepolymer and organic fine particles having an average primary particle diameter of 80 to 500 nm (Patent Document 1). This composition was an excellent HC agent capable of achieving both sufficient flexibility and surface physical properties with a film thickness of 1 to 10 μm.

[0005] By selecting an HC agent suitable for such molding applications, the restrictions on the processed surface have been somewhat relaxed. However, as the applications of film molding have expanded, new technical issues and required characteristics have emerged. For example, in the case of insert molding of a large size, in the process from preforming to setting in the injection mold, chipping, cracking, etc. have occurred, resulting in a decrease in the yield. Also, in TOM molding, when molding a substrate with relatively low heat resistance, in order to reduce damage to the substrate, there have been cases where moldability at a lower temperature is required. Therefore, there has been a growing demand for an HC film for molding that has good flexibility at room temperature for good handling properties and can be molded at a lower temperature.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem of the present invention is to provide an HC film suitable for film molding applications that has good moldability at low temperatures and excellent flexibility at room temperature, a method for manufacturing a molded product using the same, a molded product, and a molded film.

Means for Solving the Problems

[0008] In order to solve the above problems, the invention of claim 1 is a hard coat film having a cured layer of a photocurable resin composition on a polypropylene substrate, wherein the tensile elongation at break of the hard coat film at 130°C is 50 to 400%, and the polypropylene substrate does not contain a nucleating agent. A hard coat film is provided.

[0009] The invention according to claim 2 provides the hard coat film according to claim 1, characterized in that the photocurable resin composition contains a polyfunctional urethane (meth)acrylate.

[0010] The invention according to claim 3 provides the hard coat film according to claim 1, characterized in that the formable temperature when the hard coat film is vacuum pressure formed using a cylindrical shape with a diameter of 30 mm × 20 mm H is 125°C or lower.

[0011] The invention according to claim 4 provides a method for manufacturing an insert molded product, which comprises forming a resin molded product by injecting a molten resin from the side opposite to the photocurable resin cured layer after shaping the hard coat film according to any one of claims 1 to 3 using a mold.

[0012] The invention according to claim 5 provides an insert molded product or an outmold molded product using the hard coat film according to any one of claims 1 to 3.

[0013] The invention according to claim 6 provides a molded film, characterized in that the hard coat film according to any one of claims 1 to 3 further has a decorative layer and / or a pressure-sensitive adhesive layer.

Advantages of the Invention

[0014] The HC film of the present invention is useful as an HC film used in film molding such as insert molding and outmold molding because it has a high elongation at break, good formability at low temperatures, and excellent flexibility at room temperature.

Best Mode for Carrying Out the Invention

[0015] The HC film of the present invention has a cured layer of a photocurable resin composition on a polypropylene substrate that does not contain a nucleating agent. The photocurable resin composition preferably contains a polyfunctional urethane (meth)acrylate. In this specification, (meth)acrylate includes both acrylate and methacrylate, and (poly)ethylene glycol includes both ethylene glycol and polyethylene glycol.

[0016] The polypropylene base material is a crystalline olefin-based thermoplastic resin, and generally has characteristics such as low heat resistance, oil resistance, and heat distortion temperature. In this specification, polypropylene refers to a polymer containing at least polypropylene, and specifically refers to homopolypropylene and copolymers with other olefins.

[0017] The polypropylene base material used in the present invention does not contain a nucleating agent. A nucleating agent is an additive that promotes the crystallization of polymers, can shorten the induction period until crystal growth, and improve the crystallization rate of polymers. Therefore, when no nucleating agent is added, productivity decreases, and the crystals tend to be non-uniform, which may affect the moldability. On the other hand, when a nucleating agent is added, since there is a substance that serves as a crystal nucleus, the transparency tends to decrease. Also, since crystallization proceeds relatively quickly, the intermolecular bond strength tends to increase, the flexibility tends to decrease, and the molding temperature also tends to increase. In the present invention, by combining a cured layer with high tensile elongation at break and a polypropylene base material that does not contain a nucleating agent, the transparency of the film can be increased and the moldability can be improved.

[0018] The polypropylene base material can be surface-treated for the purpose of improving its adhesion to the present composition. For example, primer treatment, sandblasting method, surface roughening treatment such as solvent treatment method, or surface oxidation treatment such as corona discharge treatment, chromic acid treatment, ozone-ultraviolet irradiation treatment, etc. can be mentioned.

[0019] The thickness of the polypropylene base material is not particularly limited, and 50 to 500 μm is exemplified and can be appropriately set according to the application. Examples of commercially available products include PureThermo AG-356AS (trade name: manufactured by Idemitsu Unitech Co., Ltd., thickness 200 μm, polypropylene film without a nucleating agent), etc.

[0020] The photocurable resin composition used in the present invention (hereinafter referred to as this composition) is cured by light such as ultraviolet rays to form an HC layer. This composition contains a binder resin. For example, in the case of oligomers, acrylic resin binders such as urethane (meth)acrylate (hereinafter referred to as ureac), epoxy (meth)acrylate, polyester (meth)acrylate, polycarbonate (meth)acrylate, acrylic (meth)acrylate, and diene (meth)acrylate can be mentioned, and they can be used alone or in combination of two or more.

[0021] Among these, it is preferable to contain ureac which has abrasion resistance and toughness due to the cohesive force of hydrogen bonds derived from urethane bonds. Ureac can be obtained, for example, by reacting a urethane prepolymer obtained by reacting a polyol with an excess of polyisocyanate with a (meth)acrylate having a hydroxyl group, or by reacting a polyisocyanate with a (meth)acrylate having a hydroxyl group, and is not particularly limited.

[0022] The number of functional groups of the ureac is preferably 2 to 10 functional groups, more preferably 3 to 8 functional groups, and particularly preferably 4 to 6 functional groups. By having 2 or more functional groups, sufficient curability and adhesion to the adherend can be ensured, and by having 10 or less functional groups, excessive curing can be suppressed, and sufficient elongation at break required for a molding film can be ensured.

[0023] There is no particular limitation on the synthesis method of the ureac, and known methods can be used. The reaction may be carried out without a solvent, but as the molecular weight increases, the viscosity may increase and stirring may become difficult, so ketones such as butanone and aromatic inert solvents such as xylene may be used. In addition, it is preferable to use a catalyst for the reaction between the hydroxyl group of (meth)acrylate and the isocyanate group. Examples in that case include tin-based ones such as dibutyltin dilaurate and metal alkoxide-based ones such as cobalt naphthenate. The reaction temperature can be set appropriately, but is preferably 40 to 120°C, and more preferably 60 to 100°C.

[0024] Examples of the polyol used in the synthesis of ureak include glycol-based, polyether-based, polyester-based, polycarbonate-based, polydiene-based, etc. Specifically, alkylene glycol-based such as ethylene glycol and propylene glycol, polyether-based such as polyethylene glycol and polypropylene glycol, and polyester-based obtained by reacting these with dicarboxylic acids, etc. can be mentioned, and they can be used alone or in combination of two or more. Among these, it is preferable to contain alkylene glycol-based polyol and polyether-based polyol. In particular, ethylene glycol is preferable in that the carbon chain is short and the concentration of urethane bonds in the molecule can be increased, and polyethylene glycol is preferably contained in that the ductility of the cured product can be improved and good moldability can be ensured.

[0025] Examples of the polyisocyanate used in the synthesis of ureak include aliphatic-based such as hexamethylene diisocyanate and tetramethylene diisocyanate, alicyclic-based such as isophorone diisocyanate (hereinafter referred to as IPDI), cyclohexane diisocyanate, and hydrogenated xylylene diisocyanate, aromatic-based such as diphenylmethane diisocyanate and tolylene diisocyanate, and isocyanurate bodies and biuret bodies which are trimers of these, etc. can be mentioned, and they can be used alone or in combination of two or more. Among these, aliphatic and alicyclic diisocyanates are preferable in that they have high weather resistance and are less likely to yellow, and among them, IPDI is preferable in that it has high rigidity.

[0026] Examples of the (meth)acrylate having a hydroxyl group used in the synthesis of ureak include monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, difunctional (meth)acrylates such as glycerin di(meth)acrylate, trifunctional (meth)acrylates such as pentaerythritol tri(meth)acrylate, tetrafunctional (meth)acrylates such as dipentaerythritol tetra(meth)acrylate, etc. These can be used alone or in combination of two types. Among these, difunctional to trifunctional (meth)acrylates are preferred, and pentaerythritol triacrylate (hereinafter referred to as PETA) is particularly preferred.

[0027] The weight average molecular weight (hereinafter referred to as Mw) of the oligomer used as the binder resin is preferably 2,000 to 12,000, more preferably 3,000 to 11,000, and particularly preferably 3,500 to 10,000. By setting it to 2,000 or more, the elongation at break becomes high and sufficient moldability can be ensured. By setting it to 12,000 or less, sufficient wear resistance and scratch resistance can be ensured. Note that Mw was measured and calculated by gel permeation chromatography using a column filled with a styrene divinylbenzene substrate and a tetrahydrofuran eluent, and converting to the molecular weight in terms of standard polystyrene.

[0028] The blending amount of the binder resin is preferably 65 to 95% by weight, more preferably 70 to 93% by weight, and particularly preferably 80 to 92% by weight based on the total solid content. By setting it to 65% by weight or more, sufficient moldability and flexibility can be ensured. By setting it to 95% by weight or less, sufficient scratch resistance can be ensured. When the binder resin contains ureak, the blending ratio of ureak in the binder resin is preferably 70 to 100%, and more preferably 80 to 100%.

[0029] In this composition, a low molecular weight binder may be used as the binder resin component other than the oligomer. For example, (meth)acrylates having functional groups such as aliphatic, alicyclic, polyether skeletons, hydroxyl groups and amino groups, and acrylamide compounds can be mentioned, and they can be used alone or in combination of two or more. The number of functional groups is preferably polyfunctional in terms of reactivity. For example, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and the like can be mentioned.

[0030] This composition preferably contains a photoinitiator. The photoinitiator generates radicals upon irradiation with ultraviolet rays, electron beams, etc., and these radicals trigger the polymerization reaction. General-purpose photoinitiators such as benzyl ketal-based, acetophenone-based, and phosphine oxide-based can be used. By arbitrarily selecting the light absorption wavelength of the polymerization initiator, curability can be imparted over a wide wavelength range from the ultraviolet region to the visible light region. Specifically, 2,2-dimethoxy-1,2-diphenylethane-1-one for the benzyl ketal-based, 1-hydroxy-cyclohexyl-phenyl-ketone and 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one for the α-hydroxyacetophenone-based, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one for the α-aminoacetophenone-based, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide for the acylphosphine oxide-based, etc. are available, and they can be used alone or in combination of two or more.

[0031] Among these, it is preferable to contain α-hydroxyacetophenone-based compounds that are less likely to turn yellow. Commercially available products include Omnirad 127D, 184, and 2959 (trade name: manufactured by IGM Resins). The blending amount of the radical polymerizable component of the photoinitiator is preferably 2 to 15 parts by weight, and more preferably 5 to 12 parts by weight, based on 100 parts by weight of the radical polymerizable component.

[0032] It is preferable to blend a leveling agent in this composition. By blending a leveling agent, the leveling characteristics during coating can be improved, and it becomes easier to obtain a good coating film appearance. For example, fluorine-based, silicone-based, fluorosilicone-based, etc. can be mentioned, and they can be used alone or in combination of two or more. Among these, silicone-based polysiloxane compounds that can equalize a large surface tension difference on the coating film surface are preferable. For example, polyalkylsiloxane, polyarylsiloxane, polyalkylarylsiloxane, polyester-modified siloxane, polyether-modified siloxane, etc. can be mentioned, and they can be used alone or in combination of two or more.

[0033] As the blending amount of the leveling agent, 0.1 to 3% by weight is preferable, and 0.3 to 2% by weight is more preferable, based on the total solid content. By setting it within this range, sufficient leveling property can be ensured and a stable coating film appearance can be obtained. Commercially available products include BYK-UV3570 (trade name: manufactured by BYK Chemie, acryloyl group-containing polyester-modified polydimethylsiloxane compound), etc.

[0034] It is preferable to blend nanoalumina particles in this composition. By blending nanoalumina particles, the hardness of the cured layer can be increased to improve the abrasion resistance, and in particular, the resistance to scratching caused by a car washing machine or the like can be improved. The primary average particle diameter of the nanoalumina particles is preferably 10 to 300 nm, more preferably 30 to 200 nm, particularly preferably 50 to 150 nm, and especially preferably 70 to 100 nm. By setting it to 10 nm or more, the resistance to car wash scratches can be improved, and by setting it to 300 nm or less, good optical properties in the film can be ensured.

[0035] The compounding amount of the nano-alumina particles is preferably 0.1 to 20.0% by weight, more preferably 0.5 to 15.0% by weight, and particularly preferably 1.0 to 10.0% by weight based on the total solid content of the resin composition. By setting it at 0.1% by weight or more, an improvement in car wash scratch resistance can be expected, and by setting it at 20.0% by weight or less, sufficient moldability can be ensured.

[0036] It is preferable to compound a light stabilizer in this composition. By compounding a light stabilizer, it is possible to reduce the deterioration of the cured film due to ultraviolet exposure and radiant heat when used outdoors. For example, radical scavengers that efficiently trap alkyl radicals and peroxy radicals generated from polymers photodegraded by ultraviolet rays, and ultraviolet absorbers that suppress the decomposition of polymers by converting the energy of absorbed ultraviolet rays into thermal energy, etc. can be mentioned.

[0037] Examples of the radical scavenger include hindered amine-based (hereinafter referred to as HALS-based), hindered phenol-based, aromatic amine-based, etc., and they can be used alone or in combination of two or more. Among these, HALS-based with high radical scavenging efficiency even at low concentrations is preferable. The compounding amount of the radical scavenger 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 setting it within this range, sufficient light stability can be ensured. Commercially available products of HALS-based include Tinuvin123 and Tinuvin249 (trade name: manufactured by BASF Japan Ltd.), etc.

[0038] The ultraviolet absorber is a radical chain initiation inhibitor having an absorption band in the harmful ultraviolet region with high energy. By using it in combination with a radical scavenger, the weather resistance can be further improved and stabilized. Examples include benzotriazole-based, triazine-based, benzophenone-based, etc., and they can be used alone or in combination of two or more. Among these, hydroxyphenyltriazine-based which can strongly absorb the long wavelength part of ultraviolet rays is preferred. The compounding amount of the ultraviolet absorber is preferably 0.3 to 5% by weight, more preferably 0.5 to 3.0% by weight, and particularly preferably 0.6 to 1.5% by weight based on the total solid content. By setting it within this range, sufficient ultraviolet absorption characteristics can be ensured. Also, the total compounding amount (E) of the radical scavenger and the ultraviolet absorber is preferably 1.0 to 12% by weight, more preferably 1.5 to 10% by weight, and particularly preferably 4.0 to 8.0% by weight based on the total solid content. By setting it at 1.0% by weight or more, improvement in weather resistance can be expected, and by setting it at 12% by weight or less, over-compounding does not occur and sufficient adhesion to the base material can be ensured. Commercially available products include Tinuvin460 and 477 (trade name: manufactured by BASF Japan Ltd.), etc.

[0039] In this composition, a leveling agent, an inorganic filler, a light stabilizer, an adhesion promoter, a bluing agent, a pigment, an antifoaming agent, a thickener, an anti-precipitation agent, an antistatic agent, an anti-fogging agent, an antibacterial agent, a wax, a matting agent, a hydrophilic agent, a water repellent, organic fine particles, etc. may be added as necessary within the range that does not impair the performance.

[0040] When applying this composition to a plastic substrate, it may be diluted with a solvent to improve the coating properties. For example, 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 (hereinafter referred to as 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 (hereinafter referred to as PGM), diethyl ether, and diisopropyl ether, and hydrocarbon-based solvents such as cyclohexane and methylcyclohexane can be mentioned, and they can be used alone or in combination of two or more. The solid content in the case of dilution is exemplified by 10 to 70%, but there is no particular specification, and it can be appropriately set to a viscosity that is easy to coat.

[0041] The method of applying this composition is not particularly limited, and it 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, and wire bar, or printing methods such as gravure printing, screen printing, offset printing, and inkjet printing. The film thickness to be coated can be exemplified by 1 μm to 20 μm when dry, but it is not limited thereto.

[0042] The light source for ultraviolet irradiation used when curing this composition is not particularly limited, and examples include known low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, LED lamps, electrodeless ultraviolet lamps, etc. The atmosphere for irradiation may be in air or in an inert gas such as nitrogen or argon. Also, by heating the back roll during ultraviolet irradiation or heating the coating film with an IR heater or the like, the curability can be further improved. The irradiation conditions include an irradiation intensity of 500 mW / cm 2 ~3000 mW / cm 2 and an exposure amount of 50 to 400 mJ / cm 2 are exemplified, but it is not limited thereto.

[0043] The HC film obtained by coating and curing this composition on a polypropylene substrate (hereinafter referred to as this HC film) has an elongation at break of 50% to 400% in an atmosphere of 130 °C, more preferably 100% to 300%, and particularly preferably 150 to 250% or more. By setting the elongation at break to 50% or more, sufficient formability can be expected.

[0044] An ornamental layer and an adhesive layer may be provided on this HC film as required. Also, a backing sheet layer may be provided as a reinforcing layer. The arrangement of these layers with respect to the substrate may be arbitrary except that the HC layer is the topmost layer. A laminate including an ornamental layer or / and an adhesive layer or / and a backing sheet layer other than the HC layer is hereinafter referred to as this formed film.

[0045] Examples of the layer structure of this formed film include, but are not limited to, HC layer / substrate / ornamental layer / adhesive layer, HC layer / ornamental layer / substrate / adhesive layer, HC layer / substrate / ornamental layer / backing sheet layer, HC layer / ornamental layer / substrate / backing sheet layer, HC layer / substrate / adhesive layer / backing sheet layer, HC layer / ornamental layer / substrate / adhesive layer / backing sheet layer, HC layer / substrate / ornamental layer / adhesive layer / backing sheet layer, etc. Also, for the purpose of improving adhesion between layers, a primer layer and an adhesive layer may be further arranged.

[0046] The ornamental layer can usually be formed by a known printing method such as gravure printing, offset printing, silk screen printing, transfer printing, inkjet printing, etc. using printing ink. As the binder of the printing ink, for example, acrylic-based, polyester-based, urethane-based, vinyl chloride-vinyl acetate copolymer-based, etc. can be used alone or in combination of two or more. Further, in addition to these, those obtained by appropriately mixing colorants such as pigments and dyes, stabilizers, plasticizers, curing agents, catalysts, etc. are used.

[0047] As the coloring agent, inorganic pigments such as titanium white, red lead, and ultramarine blue, organic pigments such as Hansa yellow A and phthalocyanine blue, metallic pigments such as aluminum and brass, pearl pigments, fluorescent pigments, etc. can be used alone or in combination of two or more kinds. Further, instead of printing ink, metals such as aluminum, indium, chromium, nickel, gold, and silver can be used, and a film can be formed by methods such as vacuum evaporation, sputtering, and electroless plating.

[0048] When using printing ink, the thickness of the decorative layer is preferably 3 to 50 μm, more preferably 5 to 30 μm. By setting it within this range, the concealability can be enhanced, and complex designs such as gradation can be fully expressed.

[0049] The adhesive layer is usually a pressure-sensitive adhesive layer with adhesiveness. The adhesive layer contains, for example, pressure-sensitive polymers such as acrylic, polyolefin, rubber, polyester, silicone, and polyurethane. The pressure-sensitive polymer may be crosslinked with a crosslinking agent such as isocyanate, epoxy, or metal chelate. Further, the adhesive layer may be thermosetting, thermoplastic, or photocurable. Among these, acrylic is preferable in terms of high transparency and weather resistance, and crosslinked acrylic is more preferable. The adhesive layer may contain an adhesion promoter.

[0050] The adhesive layer can be formed using known methods such as gravure coater, flexo coater, roll coater, knife coater, comma coater, etc. Further, an adhesive layer previously formed into a sheet shape may be laminated.

[0051] 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. By setting it to 10 μm or more, adhesion to the uncoated body can be expected, and by setting it to 100 μm or less, the protrusion from the film edge in a high-temperature environment can be reduced, and a decrease in pencil hardness can be suppressed.

[0052] The backing sheet layer is arranged for the purpose of imparting waist strength during insert molding to facilitate handling during preforming, improving adhesion to the injection-molded resin, suppressing heat damage during injection, and further improving the concealment of the base. For example, polyethylene-based, polypropylene-based, polyester-based, polyurethane-based, polyvinyl chloride-based, acrylonitrile-butadiene-styrene (hereinafter referred to as ABS)-based, etc. may be mentioned. The backing sheet layer may be colored.

[0053] The heat distortion temperature (load deflection temperature) of the backing sheet is preferably 85 to 120°C or less. By setting the heat distortion temperature to 85°C or higher, it becomes possible to sufficiently suppress deformation and distortion due to heat when drying the printing ink of the decorative layer, and by setting it to 120°C or less, it becomes unnecessary to raise the temperature to a high level when preforming the formed film, and variations and distortions in elongation during preforming can be sufficiently suppressed. Therefore, as the material of the backing sheet, polypropylene (load deflection temperature: 100°C), ABS-based (same: 95°C), etc. are preferable.

[0054] For the protection of the surface of the formed film coated with the present composition, a protective film may be laminated. By using a protective film, it is possible to prevent damage during insert molding and outmold molding processes, and an improvement in yield can be expected.

[0055] As a method of using the formed film in insert molding, for example, the surface coated with the present composition is arranged so as to face the inner wall surface of the mold (so that the opposite surface of the cured layer of the present composition contacts the molding resin), and if necessary, the present HC film is made to follow the mold shape and preformed, and then the mold is closed and molten molding resin is injected into the cavity, and the resin is solidified to form a resin molded product.

[0056] As a method for performing the above preforming, the present HC film can be preheated to a temperature equal to or higher than its softening point and placed in a mold, and then vacuum suction can be performed through suction holes provided in the mold. Alternatively, a molding die different from the injection molding die can be used, and known molding methods such as vacuum molding, pressure air molding, and press molding can be employed. It is also possible to simultaneously perform integral molding of the molding and the injection resin by the injection pressure of the molding resin without performing these preformings.

[0057] As the resin for injection molding, it is possible to use known resins that can be injection molded. For example, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, acrylic resin, urethane resin, polyester resin, polycarbonate resin, polyphenylene ether resin, polyacetal resin, polysulfone resin, etc. can be mentioned, and they can be used alone or in combination of two or more. When the size is large like an automobile body, or even if the size is small but the wall thickness is thin, by approximating the shrinkage rate after molding to that of the HC film, defects such as warping can be avoided. When the present molded film is insert molded, the adhesion surface with the injected resin is preferably the backing sheet layer or the adhesive layer.

[0058] By using an HC film for molding a polypropylene substrate and injection molding with polypropylene resin, the substrate of the HC film and the injection molding resin can be made the same, enabling the molded product to be made of a single material. A molded product composed of a single material does not require separation by material when discarded, so it is easy to recycle. Also, by preventing the mixing of materials during recycling, the quality of recycled products can be improved.

[0059] Furthermore, this formed film can also be used for outmold forming. For example, it may be used for TOM (Three-Dimensional Overlay Method) forming. TOM forming is a film forming method in which a three-dimensional surface decoration is performed on a base material pre-formed in an airtight box by vacuum and pressure air forming. By using this formed film, it is possible to handle three-dimensional large-sized products regardless of the material of the base material. When performing TOM forming on this formed film, it is preferable that the surface in close contact with the molded product is the adhesive layer.

[0060] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but these are merely specific examples and are not particularly limited thereto. When there is no notation, the measurement was performed under the conditions of room temperature of 25°C and relative humidity of 65%. Also, the blending amount is shown in parts by weight in terms of solid content.

Examples

[0061] Preparation of Ureak 1 Into a four-necked flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 200 parts by weight of ethylene glycol, 825 parts by weight of IPDI (NCO group 37.5%), a catalyst, and MEK were charged so that the solid content became 50%, and the mixture was stirred and reacted at 80°C for 6 hours. When the peak of the isocyanate group reached a predetermined amount by infrared absorption analysis, the reaction was terminated. Next, 438 parts by weight of PETA (hydroxyl value 120 mgKOH / g) was added, and the mixture was stirred and reacted at 70°C for 6 hours. After confirming the disappearance of the isocyanate group by infrared absorption analysis, the solid content was adjusted to 50% with MEK to obtain a 6-functional ureak 1 with Mw 6,200 (number average molecular weight 2,800).

[0062] According to the above production method, a ureak 2 having the same skeleton as ureak 1 but different Mw and a ureak 3 using polyethylene glycol instead of ethylene glycol were obtained. Ureak 2: PETA-IPDI-(ethylene glycol-IPDI)n-PETA skeleton, 6-functional, solid content 50%, Mw 3,200 Ureak 3: PETA-IPDI-polyethylene glycol-IPDI-PETA backbone Hexafunctional, solid content 50%, Mw 6,000

[0063] Formulation Examples 1 to 7 The Ureak 1-3 and DPHA adjusted above as the binder resin, Omnirad 2959 and 127D (trade name: manufactured by IGM Resins) as the photoinitiator, BYK-UV3500 (trade name: manufactured by BYK Chemie, acryloyl group-containing polyester-modified polydimethylsiloxane compound) as the leveling agent, nanoalumina fine particles with an average particle diameter of 70 nm as the nanoalumina, Tinuvin 249 and Tinuvin 477 (trade name: manufactured by BASF Japan) as the light stabilizer were stirred until uniformly dissolved and dispersed in the formulation of Table 1, and further PGM was added and diluted and stirred so that the solid content became 30% to obtain the photocurable resin compositions of Formulation Examples 1-7.

[0064] Plastic Substrate for Evaluation As the plastic substrate, polypropylene, PET, polycarbonate (hereinafter referred to as PC), acrylic, and acrylic / PC composite substrates described below were used. Polypropylene 1 (hereinafter referred to as PP1): Puretherm AG-356AS (trade name: manufactured by Idemitsu Unitech, polypropylene film with a thickness of 200 μm and no nucleating agent) Polypropylene 2 (hereinafter referred to as PP2): Clearene PPS-C (trade name: manufactured by Seedom, polypropylene film with a thickness of 200 μm and containing a nucleating agent) PET: U403 (trade name: manufactured by Toray, thickness 100 μm) PC: PC-1151 (trade name: manufactured by Teijin, thickness 200 μm) Acrylic: HBA007P (trade name: manufactured by Mitsubishi Chemical, thickness 75 μm) Acrylic / PC composite: EuPilon film DF02PUL (trade name: manufactured by Mitsubishi Gas Chemical, thickness 125 μm and 254 μm)

[0065] Preparation of HC Films in Examples and Comparative Examples Using the photocurable resin compositions of Formulation Examples 1 to 7 as the HC resin, they were applied to the above-mentioned plastic substrate for evaluation to a dry film thickness of 3 μm, dried in a thermostat at 80 °C for 1 minute, and then irradiated with ultraviolet light using a high-pressure mercury lamp so that the integrated light quantity became 200 mJ / cm 2 to prepare an HC film for evaluation. For the acrylic / PC composite substrate, it was applied to the PMMA surface side.

[0066] Table 1 JPEG0007698772000001.jpg68135

[0067] The evaluation method was as follows.

[0068] Transparency: Using a haze meter HAZE-GARD i manufactured by BYK Gardner, the haze was measured in accordance with JIS K7136. If it was less than 10%, it was marked as ○; if it was 10% or more, it was marked as ×.

[0069] Abrasion resistance: Using a friction tester FR-IBS manufactured by Suga Test Instruments Co., Ltd., a friction member (diameter 16 mm) with a test white cotton cloth (Kanakin No. 3) attached was used to apply a load of 9 N to the resin composition coating surface of the hard coat film, and it was reciprocated 100 mm at a speed of 1 reciprocation / 1 second. After 100 reciprocations, the presence or absence of scratches was confirmed. If there were no scratches, it was marked as ○; if there were scratches, it was marked as ×.

[0070] Adhesion: In accordance with the cross-cut method of JIS K 5600-5-6, a grid of 10×10 was created on the coated surface at 1 mm intervals, and cellophane tape CT-24 (product name: manufactured by Nichiban Co., Ltd.) was pasted. The peeling situation was confirmed by pulling it upward. If there was no peeling, it was marked as ○; if there was peeling, it was marked as ×. No peeling: 100 / 100, Peeling: 0 / 100 - 99 / 100

[0071] Tensile fracture elongation: The HC film was cut into a size of 25 mm in width and 110 mm in length. Using the TechnoGraph TGI-1KN manufactured by Minebea Co., Ltd., a tensile test was conducted at an ambient temperature of 130°C and a pulling speed of 300 mm / min with a chuck distance of 50 mm. The evaluation was visually checking for cracks in the HC layer. When the elongation rate was less than 50%, it was marked as ×; when it was between 50% and 100%, it was marked as ○; when it was over 100%, it was marked as ◎. Calculation formula: Calculated based on how many millimeters it elongated with 50 mm as the reference. Length of elongation (mm) / 50 mm × 100 = Elongation rate %

[0072] Forming temperature: Using the TOM forming machine NGF-T-0203 manufactured by Busch Vacuum Co., Ltd., after heating the hard coat film, vacuum pressure-air forming was performed for 15 seconds under a pressure-air condition of 300 kPa using a cylindrical shape with a diameter of 30 mm × 20 mmH. At that time, the temperature at which it could be fully shaped was defined as the forming temperature of that film. The evaluation method was that when it was less than 125°C, it was marked as ◎; when it was between 125°C and 150°C, it was marked as 〇; when it was over 150°C and unable to be formed, it was marked as ×.

[0073] Flexibility: Using the cylindrical mandrel tester CAT - NO.5710 manufactured by BYK Gardner, a 180° bending was performed on a test film with a sample size of 120 mm × 30 mm, and the diameter without cracks was measured. The evaluation method was that when the HC surface was on the outside (outer fold), when the radius was 4 mm or less, it was marked as 〇; when it was between 5 mm and 7 mm, it was marked as △; when it was 8 mm or more, it was marked as ×.

[0074] Evaluation Results of Examples Table 2 JPEG0007698772000002.jpg89135

[0075] Evaluation Results of Comparative Examples Table 3 JPEG0007698772000003.jpg79135

[0076] In the examples, there were no problems in terms of transparency, abrasion resistance, adhesion, tensile fracture elongation, forming temperature, and flexibility, and they were all good.

[0077] On the one hand, Comparative Example 1 using a binder with low elongation at break had poor formability and low flexibility. Comparative Example 2 using a polypropylene base material blended with a nucleating agent had poor transparency. Further, Comparative Examples 3 to 7 using materials other than the polypropylene base material were inferior in any one of the tensile elongation at break, molding temperature, and flexibility, and were not suitable for the present invention.

Claims

1. A hard coat film having a cured layer of a photocurable resin composition on a polypropylene substrate, the hard coat film having a tensile elongation at break of 50 to 400% at 130°C, and the polypropylene substrate not containing a nucleating agent.

2. 2. The hard coat film according to claim 1, wherein the photocurable resin composition contains a polyfunctional urethane (meth)acrylate.

3. 2. The hard coat film according to claim 1, wherein the moldable temperature when the hard coat film is subjected to vacuum and pressure molding using a cylindrical mold having a diameter of 30 mm and a height of 20 mm is 125[deg.] C. or lower.

4. A method for producing an insert molded article, comprising the steps of: shaping the hard coat film according to any one of claims 1 to 3 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.

5. An insert molded product or an out-molded product using the hard coat film according to any one of claims 1 to 3.

6. A molded film comprising the hard coat film according to any one of claims 1 to 3, further comprising a decorative layer and / or a pressure-sensitive adhesive layer.

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