JPWO2019235086A1 - A curable resin composition, a film using the same, and a molded product using the film. - Google Patents

Abstract

An object of the present invention is to provide a curable resin composition capable of forming a cured film having elongation that does not hinder injection molding and having high chemical resistance. The curable resin composition according to the present invention comprises a polyurethane (meth) acrylate compound (A) having a urethane bond equivalent of 210 g / mol or less, a polymerization initiator (B), and an aprotic polar solvent (C). including.

Description

The present invention relates to a curable resin composition. Furthermore, the present invention relates to a molded film and a molded product using a cured film obtained by curing the curable resin composition.

The surfaces of resin molded products and plastic molded products such as automobile interiors, automobile exteriors, and electric appliances are required to have scratch resistance that is not or is not easily scratched by impact. Therefore, for the purpose of improving the scratch resistance of the surface of these molded products, it is widely practiced to provide a scratch resistant protective layer. Conventionally, a scratch-resistant protective layer is provided by applying a scratch-resistant component or the like after obtaining a resin molded product or a plastic molded product by an injection molding method or the like. However, if a resin molded product or a plastic molded product having a scratch-resistant protective layer can be obtained at one time by an injection molding method, the molding process is reduced and it is economically advantageous. Therefore, attempts have been made to develop a curable composition capable of forming a protective layer having both high elongation and scratch resistance that can withstand an injection molding method.

According to Japanese Patent No. 6123428, an active energy ray capable of forming a cured film having flexibility, breaking strength and mechanical strength, scratch repairability, scratch resistance, etc. that can follow deformation during three-dimensional processing. Curable resin compositions are disclosed. The active energy ray-curable resin composition contains a polyisocyanate, a polycarbonate polyol, and a urethane (meth) acrylate-based oligomer which is a reaction product of hydroxyalkyl (meth) acrylate, and has a predetermined tensile elastic modulus of the cured film. It is characterized by having a value.

The active energy ray-curable resin composition according to Patent Document 1 can form a cured film having flexibility and scratch resistance as described above, but has a problem of whitening in contact with a chemical. Therefore, the present invention provides a curable resin composition capable of forming a cured film having both high elongation to withstand deformation in an injection molding method including an insert molding method and scratch resistance and also having chemical resistance. The purpose is to do.

The curable resin composition according to the embodiment of the present invention comprises a polyurethane (meth) acrylate compound (A) having a urethane bond equivalent of 210 g / mol or less, a polymerization initiator (B), and an aprotic polar solvent (C). ) And a curable resin composition. Here, the polyurethane (meth) acrylate compound (A) is composed of the following compounds: a polyisocyanate compound (a1), a polyol compound (a2) having 1 to 6 carbon atoms, and a hydroxyalkyl (meth) acrylate compound (a3). It is characterized in that it is a compound obtained by reacting.
Another embodiment of the present invention is a molded film having a cured film formed by curing a curable resin composition and a base material.
Yet another embodiment of the present invention is a molded product having a cured film formed by curing the curable resin composition and a cured film formed by curing the curable resin composition on the surface.

The molded film formed by using the curable resin composition of the present invention has sufficient elongation in thermoforming such as an injection molding method. Further, in the molded product in which the molded film of the present invention is used for processing the surface of the resin molded product or the plastic molded product, the cured film is in close contact with the surface of the molded product, and the surface thereof is effectively protected.

Embodiments of the present invention will be described below. One embodiment of the present invention comprises a polyurethane (meth) acrylate compound (A) having a urethane bond equivalent of 210 grams / mol or less, a polymerization initiator (B), and an aprotic polar solvent (C). It is a curable resin composition.

In the present embodiment, the curable resin composition exists in a liquid state at room temperature, and undergoes a curing reaction triggered by irradiation of active energy such as ultraviolet rays, infrared rays, and X-rays, addition of thermal energy, addition of chemical substances, and the like. It is a mixture containing a resin or plastic or a raw material monomer thereof as a main component, which can form a cured product or a cured film. The curable resin composition is used in a wide range of applications such as paints, sealants, encapsulants, and adhesives, and it is necessary to satisfy various required performances depending on the application. The cured product of the curable resin composition of the present embodiment is used as a film for processing or decorating the surface of a molded product such as resin, plastic, or metal, and the cured film adheres to the surface of the molded product. It is hard to peel off, and it is possible to prevent the formation of scratches due to an external impact.

The curable resin composition of the present embodiment contains a polyurethane (meth) acrylate compound (A) having a urethane bond equivalent of 210 g / mol or less. The polyurethane (meth) acrylate compound is a polymer having a urethane bond in the molecule and having a polymerization group selected from an acrylic group or a methacrylic group, that is, a polymer or an oligomer. The polyurethane (meth) acrylate compound (A) contains an acrylic group or a methacrylic group that is cleaved by irradiation with active energy rays, heat application, or addition of a polymerization initiator to initiate radical polymerization. The urethane bond equivalent of the polyurethane (meth) acrylate compound (A) is 210 grams / mol or less. Here, the urethane bond equivalent refers to the weight average molecular weight of the polyurethane (meth) acrylate compound (A) (that is, the weight of 1 mol of the polyurethane (meth) acrylate compound (A)) and the polyurethane (meth) acrylate compound (A). It is a ratio to the number of urethane bonds present in, and the unit is gram / mol. A small value of urethane bond equivalent means that a large amount of urethane bond is present in the molecule of the polyurethane (meth) acrylate compound (A).

When a polyurethane (meth) acrylate compound having a small urethane bond equivalent value is used as (A), many urethane bonds are present in the cured film polymer obtained by curing the curable resin composition. When the urethane bond equivalent of the polyurethane (meth) acrylate compound (A) is 210 g / mol or less, it is possible to secure a sufficient number of urethane bonds to impart chemical resistance to the cured film.

In the embodiment, the polyurethane (meth) acrylate compound as the component (A) is a polyisocyanate compound (a1), a polyol compound (a2) having 1 to 6 carbon atoms, and a hydroxyalkyl (meth) acrylate compound (a3). It is preferably a compound obtained by reacting. The polyisocyanate compound (a1) is a compound having two or more isocyanato groups (-N = C = O) in one molecule. As the polyisocyanate compound (a1), it is particularly preferable to use a diisocyanate compound having two isocyanato groups in the molecule. Here, as the diisocyanate compound, bis (isocyanatomethyl) cyclohexane, cyclohexanediisocyanate, diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (tolylene diisocyanate, TDI), xylylene diisocyanate (XDI), isophorone diisocyanate ( IPDI), cyclohexyldiisocyanate, dicyclohexylmethane 4,4'-diisocyanate and the like, and one or more of these can be used.

The polyol compound (a2) is a compound having two or more hydroxyl groups (-OH) in one molecule. In the embodiment, the polyol compound (a2) preferably has 1 to 6 carbon atoms. By using a polyol compound having a relatively low molecular weight as (a2), the number of urethane bonds in the polyurethane (meth) acrylate compound (A) can be increased. That is, the urethane bond equivalent of the polyurethane (meth) acrylate compound (A) can be adjusted by adjusting the carbon number of the polyol compound (a2). Examples of such polyol compounds include methanediol, ethanediol, n-propanediol, isopropanediol, n-butanediol, isobutanediol, t-butanediol, n-pentanediol, n-hexanediol, and dihydroxycyclohexane. Orid or alicyclic diol compounds, aliphatic or alicyclic diol compounds such as 1,2,4-butanetriol, aromatic diol compounds such as catechol, resorcinol, hydroquinone, hydroxyquinol, fluoroglycolsinol, pyrogallol, etc. Aromatic triol compounds of the above can be mentioned, and one or more of these can be used.

The hydroxyalkyl (meth) acrylate compound (a3) is a compound having a hydroxyalkyl group (alkyl group having a hydroxyl group) and an acrylic group or a methacryl group in one molecule. Examples of the hydroxyalkyl (meth) acrylate compound include hydroxymethyl acrylate, hydroxymethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like. One or more of them can be used.

A urethane bond is formed by reacting the isocyanato group existing in (a1), the hydroxyl group existing in (a2), and the hydroxyl group existing in (a3) to form a polyurethane (meth) acrylate compound (A). Can be generated. Preferably, the polyurethane (meth) acrylate compound (A) is produced by first reacting the component (a1) with the component (a2) and then adding the component (a3). The polyurethane (meth) acrylate compound (A) contains a radically polymerizable group (acrylic group or methacrylic group) derived from (a3). The reaction of the radically polymerizable group contributes to the curing of the curable resin composition of the embodiment.

The curable resin composition of the embodiment contains a polymerization initiator (B) in addition to the polyurethane (meth) acrylate compound (A). The polymerization initiator is a compound that initiates the polymerization reaction of a monomer in response to a stimulus such as irradiation with light or application of heat. In the curable resin composition of the embodiment, it is preferable to use a photopolymerization initiator that initiates polymerization by irradiation with light including ultraviolet rays, electron beams, and visible light. Photopolymerization initiators that generate radically active species upon irradiation with light (eg, acetylbenzene, dimethoxybenzyl, dibenzoyl, benzoin, benzophenone, benzoylbenzoic acid, bis (dimethylamino) benzophenone, bis (diethylamino)) ) Benzenephenone, chlorothioxone, ethylanthraquinone), photocationic polymerization initiators that generate cationically active species (eg, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-fluorophenyl) iodonium trifurate) , Diphenyliodonium hexafluorophosphate, 2,4-bis (trichloromethyl) -6- [2- (fran-2-yl) vinyl] -1,3,5-triazine, 4-nitrobenzenediazonium tetrafluoroborate) , Photoanion polymerization initiators (acetophenone-O-benzoyloxime, cyclohexylcarbamic acid 1,2-bis (4-methoxyphenyl) -2-oxoethyl, nifedipine) that generate anionic radicals can be used. As the photopolymerization initiator, a commercially available product such as Irgacure (BASF) can be used. Irgacure 184 (1-hydroxycyclohexylphenyl ketone), Irgacure 907 (2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1-one), Lucillin TPO (2,4,6-trimethyl) Benzoyldiphenylphosphine oxide) and the like can be used. Moreover, these may be used individually or in mixture of 2 or more types.

The curable resin composition of the embodiment contains an aprotic polar solvent (C). The aprotic polar solvent is a polar solvent that does not have a proton donating group in the molecule. As aprotonic polar solvents, ethers such as diethyl ether and tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, dimethyl sulfoxide, N, N-dimethylformamide and hexamethylphosphoric triamide. And so on. The aprotic polar solvent (C) can be used by using one or a mixture of two or more of these, but from the viewpoint of dielectric constant, it contains at least one of N, N-dimethylformamide and dimethyl sulfoxide. Is preferable. The inclusion of the aprotic polar solvent (C) in the curable resin composition inhibits the intermolecular interaction of the polyurethane (meth) acrylate compound (A) contained in the curable resin composition. be able to. Therefore, the polyurethane (meth) acrylate compound (A) is uniformly distributed in the curable resin composition. When such a curable resin composition is cured, a uniform cured film can be formed. When the curable resin composition is cured, the aprotic polar solvent (C) volatilizes. Using the curable resin composition of the present embodiment, which is a combination of the polyurethane (meth) acrylate compound (A) having a predetermined urethane bond equivalent value and the aprotic polar solvent (C) as described above, more A strong cured film can be formed.

The curable resin composition of the embodiment may further contain an ethylenically unsaturated compound (D) having one or more radically polymerizable groups in the molecule. Here, the ethylenically unsaturated compound is a compound having at least one ethylenically unsaturated group (−C = C−). The ethylenically unsaturated compound (D) preferably has one or more radically polymerizable groups in the molecule. As described above, the radically polymerizable group is cleaved by irradiation with active energy rays, application of heat, or addition of a polymerization initiator, typified by a vinyl group, an acrylic group, a methacryl group, an acryloyl group, a methacryloyl group, an allyl group, etc. It is a double bond or a triple bond that initiates radical polymerization. Examples of such ethylenically unsaturated compound (D) include glycerin tri (meth) acrylate ethoxylated, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethyl propantri (meth) acrylate, and di. Polyfunctional (meth) acrylate compounds represented by methylolpropantetra (meth) acrylate and dipentaerythritol hexa (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypropyl (meth) acrylate, and hydroxyethyl (meth) acrylate. Examples thereof include (meth) acrylic monomers, (meth) acrylamides, and (meth) acrylamides typified by dimethyl (meth) acrylamide. Further, as long as it does not affect the embodiment, a polymer having at least one ethylenically unsaturated group can be used as the ethylenically unsaturated compound (D). By variously changing the ethylenically unsaturated compound (D), the elongation, hardness, adhesion to the substrate, and the like of the cured film can be changed. Therefore, the ethylenically unsaturated compound (D) can be used or not used depending on the type of the base material to which the cured film is applied, the molding method, the application of the finished molded product, and the like.

In addition to the above components, the curable resin composition of the embodiment contains additives (for example, dyes, pigments, plasticizers, dispersants, preservatives, matting agents, antistatic agents) usually contained in the curable resin composition. , Flame retardant, UV absorber, light stabilizer, antifouling agent, antiblocking agent, antibacterial agent, inorganic particles) can be blended.

The curable resin composition of the embodiment can be diluted by blending a protic polar solvent depending on the application. As the protic polar solvent, one or more alcohols such as methanol, ethanol, 1-propanol, isopropanol, ethylene glycol methyl ether, and propylene glycol monomethyl ether can be mixed and used. The curable resin composition of the embodiment diluted with a protic polar solvent may also be referred to as a "curable resin composition" in the present specification.

As a suitable curable resin composition, a polyurethane (meth) acrylate compound (A) is prepared, a polymerization initiator (B) and an appropriate amount of an aprotic polar solvent (an appropriate amount depending on the use of the curable resin composition). It can be produced by mixing C) and optionally the ethylenically unsaturated compound (D) and optionally diluting with a protic and aprotic polar solvent.

Here, the content of the polyurethane (meth) acrylate compound (A) (nonvolatile content) is the weight of the curable resin composition (that is, the component (A), the component (B), the component (C), and the component (D). It is 15 to 50%, preferably 20 to 45% based on the total weight).
The content of the polymerization initiator (B) is 0.5 to 5%, preferably 1 to 3%, based on the weight of the curable resin composition.
The content of the aprotic polar solvent (C) is 40% to 80%, preferably 45% to 75%, based on the weight of the curable resin composition.
The content of the ethylenically unsaturated compound (D) is 5 to 20%, preferably 10 to 20%, based on the weight of the curable resin composition.
The curable resin composition of the embodiment can be diluted by blending a protic polar solvent depending on the intended use. In this case, the amount of the curable resin composition containing the component (A), the component (B), the component (C), and the component (D) is 1.1 to 5 times, preferably 1.3 times, in a protonic polar solvent. It can be diluted in an amount of 2 to 3 times. That is, the content of the polyurethane (meth) acrylate compound (A) (nonvolatile content) is the total weight of the curable resin composition containing the solvent (that is, the component (A), the component (B), the component (C), the component ( Based on D) and the total weight of the diluted solvent), it can be 5 to 30%, preferably 10 to 25%.
The content of the polymerization initiator (B) is 0.1 to 3%, preferably 0.5 to 2%, based on the total weight of the curable resin composition containing the solvent.
The content of the aprotic polar solvent (C) is 20% to 60%, preferably 25% to 60%, based on the total weight of the curable resin composition containing the solvent.
The content of the ethylenically unsaturated compound (D) is 3 to 15%, preferably 5 to 10%, based on the total weight of the curable resin composition containing the solvent.

The curable resin composition of the embodiment can be applied to a suitable substrate surface and cured on the surface to form a cured film. The thickness of the cured film can be changed depending on the application, but is generally 1 to 20 μm, preferably 1 to 10 μm. Examples of the base material for curing the curable resin composition include glass, plastic, and metal. The curable resin composition of the embodiment is particularly preferably cured on plastic to form a cured film. Can be formed. As the base material, for example, an acrylic resin or a polycarbonate resin whose outermost layer is covered with an acrylic resin can be used. The curable resin composition can be appropriately applied to the surface of the base material by a conventional coating method. The applied curable resin composition can be heated to form a cured film. The heating of the curable resin composition is carried out by the action of the polymerization initiator (B) in the curable resin composition to polymerize or co-polymerize the polyurethane (meth) acrylate compound (A) and, in some cases, the ethylenically unsaturated compound (D). It may be heated to a temperature sufficient to initiate the polymerization reaction. Although it depends on the types of (A) and (D) used and the polymerization initiator (B), the copolymerization reaction can be started by heating to about 80 to 150 ° C., preferably about 100 to 150 ° C. it can. The curable resin composition coated product can be heated by a heating device such as a burner or an oven, or by a heating method using warm air such as a dryer.

In addition, the curable resin composition of the embodiment is applied to the surface of the base material, and the coated surface is irradiated with active energy rays to obtain a polyurethane (meth) acrylate compound (A) and, in some cases, an ethylenically unsaturated compound (D). The polymerization or copolymerization reaction of the above may be started. Examples of the active energy rays to be irradiated include visible light, ultraviolet light, infrared light, alpha rays, beta rays, gamma rays, and X-rays.

In this way, the curable resin composition of the embodiment can be cured on a plastic base material to form a cured film, and a molded film can be formed. The molded film of the embodiment can be used as a film for processing the surface of a molded product such as plastic. The molded film of the embodiment may have a pattern, a pattern, a pattern, a color, or the like, or may be transparent. A molded film having a pattern or the like is called a decorative film, and is preferably used for applying a pattern or the like to the surface of a molded product. The molding film of the embodiment can be loaded into an injection molding die, and the cured film can be attached to the molded product at the same time as injection molding (insert molding method). Further, the molded film of the embodiment can be attached to the surface of the molded product, the base material can be peeled off, and the cured film having a pattern or a pattern can be transferred (transfer method). The cured film obtained by curing the curable resin composition of the embodiment has heat resistance to an injection molding method and sufficient extensibility along the surface of the molded product, and adheres to the surface of the molded product. Therefore, a strong film can be formed.

(1) Preparation of curable resin composition (1-1) Synthesis of polyurethane (meth) acrylate compound (A-1) In a 300 mL eggplant-shaped flask, dicyclohexylmethane-4,4'-diisocyanate 30 as a component (a1). 0.0 parts by weight, 6.9 parts by weight of ethylene glycol as the component (a2), 98.7 parts by weight of N, N-dimethylformamide as the component (C), and 0.024 parts by weight of the catalyst dioctyltin dilaurate. Was charged and reacted at 70 ° C. for 6 hours with stirring. After completion of the reaction, 5.4 parts by weight of pentaerythritol triacrylate (manufactured by Toa Synthetic Co., Ltd., trade name: Aronix M-306) was added as a component (a3), and the mixture was reacted at 60 ° C. for 6 hours to have a radically polymerizable group. Polyurethane acrylate (A-1) was obtained.
Weight average molecular weight = 12100, non-volatile content = 30%, urethane bond equivalent = 170 grams / mol

The polyurethane (meth) acrylate compound synthesized in Examples and Comparative Examples described below is a mixture of a polyurethane (meth) acrylate compound and an aprotic polar solvent as a reaction solvent. The “nonvolatile content” refers to a substantial proportion of the polyurethane (meth) acrylate compound contained in the mixture obtained by the reaction. For example, in the above polyurethane acrylate (A-1), "nonvolatile content = 30%" means that a mixture of 30% of polyurethane acrylate (A-1) and 70% of N, N-dimethylformamide as a reaction solvent can be obtained. , Means that this was used as the component (A-1). The synthesis of the following polyurethane (meth) acrylate compounds will be described in the same manner.

(1-2) Synthesis of polyurethane (meth) acrylate compound (A-2) In a 300 mL eggplant-shaped flask, 30.0 parts by weight of dicyclohexylmethane-4,4'-diisocyanate as a component (a1) and a component (a2) As a result, 6.6 parts by weight of ethylene glycol, 110.0 parts by weight of N, N-dimethylformamide as a component (C), and 0.024 parts by weight of dioctyltin dilaurate as a catalyst were charged, and 6 at 70 ° C. with stirring. Time reacted. After completion of the reaction, 11.2 parts by weight of pentaerythritol triacrylate (manufactured by Toa Synthetic Co., Ltd., trade name: Aronix M-306) was added as a component (a3), and the mixture was reacted at 60 ° C. for 6 hours to have a radically polymerizable group. Polyurethane acrylate (A-2) was obtained.
Weight average molecular weight = 5600, non-volatile content = 30%, urethane bond equivalent = 179 grams / mol

(1-3) Synthesis of polyurethane (meth) acrylate compound (A-3) In a 300 mL eggplant-shaped flask, 30.0 parts by weight of dicyclohexylmethane-4,4'-diisocyanate as a component (a1) and a component (a2) As a result, 6.6 parts by weight of ethylene glycol, 110.0 parts by weight of N, N-dimethylformamide as a component (C), and 0.024 parts by weight of dioctyltin dilaurate as a catalyst were charged, and 6 at 70 ° C. with stirring. Time reacted. After completion of the reaction, 37.6 parts by weight of pentaerythritol triacrylate (manufactured by Toa Synthetic Co., Ltd., trade name: Aronix M-306) was added as a component (a3), and the mixture was reacted at 60 ° C. for 6 hours to have a radically polymerizable group. Polyurethane acrylate (A-3) was obtained.
Weight average molecular weight = 5000, non-volatile content = 40%, urethane bond equivalent = 181 g / mol

(1-4) Synthesis of polyurethane (meth) acrylate compound (A-4) In a 300 mL eggplant-shaped flask, 30.0 parts by weight of dicyclohexylmethane-4,4'-diisocyanate as a component (a1) and a component (a2) As a result, 9.6 parts by weight of 1,4-butanediol, 118.6 parts by weight of N, N-dimethylformamide as a component (C), and 0.024 parts by weight of dioctyltin dilaurate as a catalyst were charged and stirred. The reaction was carried out at 70 ° C. for 6 hours. After completion of the reaction, 11.2 parts by weight of pentaerythritol triacrylate (manufactured by Toa Synthetic Co., Ltd., trade name: Aronix M-306) was added as a component (a3), and the mixture was reacted at 60 ° C. for 6 hours to have a radically polymerizable group. Polyurethane acrylate (A-4) was obtained.
Weight average molecular weight = 5600, non-volatile content = 30%, urethane bond equivalent = 194 grams / mol

(1-5) Synthesis of polyurethane (meth) acrylate compound (A-5) In a 300 mL eggplant-shaped flask, 30.0 parts by weight of dicyclohexylmethane-4,4'-diisocyanate as a component (a1) and a component (a2) 12.5 parts by weight of 1,6-hexanediol, 125.3 parts by weight of N, N-dimethylformamide as a component (C), and 0.024 parts by weight of dioctyltin dilaurate as a catalyst were charged and stirred. The reaction was carried out at 70 ° C. for 6 hours. After completion of the reaction, 11.2 parts by weight of pentaerythritol triacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-306) was added as a component (a3) and reacted at 60 ° C. for 6 hours to produce a polyurethane acrylate compound (A-5). ) Was obtained.
Weight average molecular weight = 5600, non-volatile content = 30%, urethane bond equivalent = 208 grams / mol

(1-6) Synthesis of Polyurethane (Meta) Acrylate Compound (A'-1) A polyurethane (meth) acrylate compound having a large urethane bond equivalent value was synthesized. In a 500 mL eggplant-shaped flask, 30.0 parts by weight of isophorone diisocyanate, 57.2 parts by weight of polycarbonate diol (trade name: Duranol T4691), and 4.3 parts by weight of 1,4-butanediol. 150.0 parts by weight of methyl ethyl ketone (MEK) as a reaction solvent and 0.005 parts by weight of dioctyltin dilaurate as a catalyst were charged and reacted at 80 ° C. for 9 hours with stirring. After completion of the reaction, the mixture was cooled to 60 ° C., 0.03 part by weight of dioctyltin dilaurate, 0.05 part by weight of methylhydroquinone, and 10.6 parts by weight of methylethylketone were added, and 8.1 part by weight of 2-hydroxyethylmethacrylate was added dropwise. The reaction was carried out at 70 ° C. for 10 hours to obtain a polyurethane methacrylate compound (A'-1).
Weight average molecular weight = 4250, non-volatile content = 40%, urethane bond equivalent = 371 grams / mol

(1-7) Synthesis of Polyurethane (Meta) Acrylate Compound (A'-2) A polyurethane (meth) acrylate compound having a large urethane bond equivalent value was synthesized. In a 500 mL eggplant-shaped flask, 77.7 parts by weight of dicyclohexylmethane-4,4'-diisocyanate, 45.1 parts by weight of glycerin monomethacrylate (trade name: Blemmer GLM), and a reaction solvent. 204.8 parts by weight of ethyl acetate (EA) and 0.004 parts by weight of dioctyltin dilaurate as a catalyst were charged and reacted at 60 ° C. for 6 hours with stirring. After completion of the reaction, 14.6 parts by weight of pentaerythritol triacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-306) was added and reacted at 60 ° C. for 6 hours to obtain a polyurethane acrylate compound (A'-2). ..
Weight average molecular weight = 9200, non-volatile content = 40%, urethane bond equivalent = 222 grams / mol

The above (A-1) to (A-5) and (A'-1) and (A'-2), Irgacure907 (BASF) as the polymerization initiator (B), and optionally an ethylenically unsaturated compound ( As D), pentaerythritol triacrylate (Aronix M-306 manufactured by Toa Synthetic Chemical Co., Ltd.) and propylene glycol monomethyl ether (PGM) or methyl ethyl ketone (MEK) as a solvent are blended in the weight ratios shown in Table 1. , The curable resin composition according to Examples 1 to 6 of the present invention and the curable resin composition according to Comparative Examples 1 to 4 were prepared. As described above, the above (A-1) to (A-5) and (A'-1) and (A'-2) are an aprotic polar solvent (aprotic polar solvent) which is a reaction solvent with the polyurethane (meth) acrylate compound. It is a mixture of C). The numerical values of (A-1) to (A-5) and (A'-1) and (A'-2) in Tables 1 and 2 indicate all of these components (that is, the aprotic polar solvent (C)). The weight ratio of). The numerical value in parentheses is the weight ratio of the non-volatile component (that is, polyurethane (meth) acrylate) only.

(2) Preparation of Cured Film of Curable Resin Composition As a base material for forming the cured film of the curable resin composition, a polycarbonate film whose outermost layer was covered with an acrylic resin was used. Each of the above curable resin compositions was applied to a substrate by a bar coating method so that the film thickness after curing was 4 μm. Then, the base material coated with the curable resin composition was dried in an oven at 100 ° C. for 1 minute, and then the curable resin composition was cured by irradiating with ultraviolet rays as active energy rays. As a result, a molded film having a cured film was obtained.

(3) Performance evaluation of molded film (3-1) Appearance evaluation For the molded film of each example, the haze value was measured using a haze meter corresponding to JIS K 7136. The larger the haze value, the more opaque, and the smaller the haze value, the more transparent.

(3-2) Adhesion Evaluation According to JIS K 5600-5-6, the presence or absence of peeling of the cured film on the molded film was visually evaluated as follows.
Pass: No peeling is found Fail: Part or all peeled

(3-3) Evaluation of Adhesion After Heating Further, each molded film is immersed in boiling water for 30 minutes, and the presence or absence of peeling of the cured film on the molded film is visually checked according to JIS K 5600-5-6 as follows. Evaluated as per.
Pass: No peeling is found Fail: Part or all peeled

(3-4) Evaluation of Scratch Resistance Each of the obtained molded films was ^{reciprocated 10 times by applying a load of 250 g / cm 2} on steel wool # 0000, and the haze value was measured using a haze meter. The difference in haze value before and after the scratch resistance test was determined. The smaller this value is, the higher the scratch resistance is.

(3-5) Evaluation of chemical resistance For each of the obtained molded films, 0.2 g of a commercially available sunscreen cream (Ultra Sheer Dry Touch Sunscreen SPF45, manufactured by Neutrogena) was applied to an area of ^{1 cm 2 and 80.} It was allowed to stand at ° C. for 1 hour. After that, the sunscreen cream applied with a large amount of water was washed, and the change in the appearance of the cured film was visually observed.
High: No change in appearance is observed Medium: Changes such as whitening are observed in a part of the appearance Low: Changes such as whitening are observed in the appearance

(3-6) Evaluation of Stretchability Each of the obtained molded films was subjected to a tensile test (sample dimensions: 200 mm × 10 mm, inter-chuck distance: 110 mm, tensile speed: 50 mm / min) at a high temperature (150 ° C.). The break point elongation was defined as the time when the cured film was visually cracked, and the stretchability of the molded film was evaluated from the result.

The numerical values in parentheses in Table 1 are the amounts of non-volatile components. For example, the numerical value "46.1" described in the column of A-1 of Table 1 Example 1 is DMF which is a reaction solvent (that is, an aprotic polar solvent (C)) with the polyurethane acrylate of A-1. It means that the total amount of and is 46.1 parts by weight, and the amount of the inner polyurethane acrylate A-1 is 13.8 parts by weight. The polyurethane (meth) acrylate as the component (A) is used in the form of a mixture of the polyurethane (meth) acrylate and the aprotic polar solvent (C) for the convenience of production, and is therefore described above in the table. Described in. The curable resin composition of Example 1 contains 46.1 parts by weight of A-1 dissolved in an aprotic polar solvent (C), 0.9 parts by weight of a polymerization initiator (B), and an ethylenically unsaturated monomer. (D) was prepared by mixing 7.7 parts by weight and 45.3 parts by weight of a diluting solvent. Similarly, the numerical values in parentheses in Table 2 are the amounts of non-volatile components. For example, the numerical value "53.9" described in the column of A'-1 in Comparative Example 1 of Table 2 is the polyurethane acrylate of A'-1 and the reaction solvent (that is, the aprotic polar solvent (C)). This means that the total amount with a certain MEK is 53.9 parts by weight, and the amount of the inner polyurethane methacrylate A'-1 is 21.6 parts by weight. The curable resin composition of Comparative Example 1 contained 53.9 parts by weight of A'-1 dissolved in an aprotic polar solvent (C), 1.2 parts by weight of the polymerization initiator (B), and 44 parts of MEK. It was produced by mixing 9 parts by weight.

The meanings of the abbreviations in the table are as follows:
Irgacure 907: 2-Methyl-1- (4-Methylthiophenyl) -2-morpholinopropan-1-one (BASF)
M-306: Pentaerythritol triacrylate (Toagosei)
PGM: Propylene Glycol Monomethyl Ether MEK: Methyl Ethyl Ketone DMF: N, N-Dimethylformamide EA: Ethyl Acetate

All of the cured coatings according to the examples of the present invention have excellent adhesion and maintain adhesion even after heating. The curable resin composition according to the embodiment of the present invention can form a cured film having excellent scratch resistance and chemical resistance. The molded film using the curable resin composition according to the embodiment of the present invention has high breaking point elongation, that is, stretchability, and has sufficient elongation to withstand an insert molding method or the like. Is suggested. On the other hand, the molded film using the curable resin composition according to the comparative example using polyurethane (meth) acrylate (A) whose urethane bond equivalent does not satisfy the provisions of the present invention has adhesiveness, scratch resistance, and chemical resistance. The performance of either property or stretchability was insufficient.

Claims (6)

A curable resin composition containing a polyurethane (meth) acrylate compound (A) having a urethane bond equivalent of 210 g / mol or less, a polymerization initiator (B), and an aprotic polar solvent (C). The polyurethane (meth) acrylate compound (A) is a compound obtained by reacting a polyisocyanate compound (a1) with a polyol compound (a2) having 1 to 6 carbon atoms and a hydroxyalkyl (meth) acrylate compound (a3). The curable resin composition according to claim 1. The curable resin composition according to claim 1 or 2, further comprising an ethylenically unsaturated compound (D) having one or more radically polymerizable groups in the molecule. The curable resin composition according to any one of claims 1 to 3, further comprising a protic polar solvent. A molded film having a cured film obtained by curing the curable resin composition according to any one of claims 1 to 4 and a base material. A molded product having a cured film on the surface obtained by curing the curable resin composition according to any one of claims 1 to 4.