JP2011084687A - Curable resin composition, film, and molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition, and a film which maintains abrasion resistance and hardness of curing coating, is excellent in tensibility, and cannot break easily in molding, and a molding method. <P>SOLUTION: The curable resin composition does not include a multifunctional (meth)acrylate monomer and/or a multifunctional acrylate oligomer (a), or substantially, an unsaturated group; has a weight-average molecular weight of 5,000-200,000; and contains an acrylic polymer (b) whose glass transition temperature is 20-200°C. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a curable resin composition, a film, and a molding method that are excellent in extensibility and in which a cured film is difficult to break during molding.

  In recent years, active energy ray-curable coatings have been used in mobile phones, home appliances, optical films, and the like in place of conventional thermosetting coatings. Active energy ray-curable coatings are rapidly spreading compared to thermosetting coatings because they are fast-curing, have good productivity, can save energy, and have excellent wear resistance and hardness.

  However, the active energy ray-curable hard coat resin composition has a high degree of wear resistance and hardness, but also has a weak point that it is brittle and easily cracked. Therefore, when the film coated and hardened with the hard coat resin composition is set in a mold and the resin is desired to be provided with wear resistance or the like, the hard coat layer may be cracked when attempting to integrally mold the resin during injection molding. .

  So, in addition to polyfunctional (meth) acrylates, attempts have been made to improve brittleness by adding high molecular weight urethane acrylate oligomers, acrylic polymers, etc. to give flexibility, but the crosslink density is reduced. Therefore, there has been a problem that the wear resistance and hardness are greatly reduced. Therefore, there has been a demand for a curable resin composition that maintains the wear resistance and hardness of the cured film while being excellent in elongation and difficult to break during molding.

Patent Document 1 discloses a resin composition containing a polyfunctional (meth) acrylate and an acrylic polymer, but the wear resistance is not sufficient. Patent Document 2 discloses a resin composition containing a polyfunctional urethane (meth) acrylate and a (meth) acrylic copolymer resin, but the toughness is not sufficient.
JP-A-9-48934 JP 2006-316249 A

  An object of the present invention is to provide a curable resin composition, a film, and a molding method that are excellent in elongation while maintaining the wear resistance and hardness of a cured film and that are difficult to break during molding.

  The present invention provides a polyfunctional (meth) acrylate monomer and / or a polyfunctional acrylate oligomer (a), substantially free of unsaturated groups, having a weight average molecular weight of 5,000 to 200,000, and a glass transition temperature. Is a curable resin composition characterized by containing an acrylic polymer (b) having a temperature of 20 to 200 ° C. The curable resin composition is applied and cured, and the film is set in a mold, and the film and the resin are integrally molded at the time of injection molding It is a molding method.

  Since the cured film of the curable resin composition of the present invention is excellent in elongation while maintaining wear resistance and hardness, it has a characteristic that it is difficult to break. Therefore, when a film obtained by applying and curing the resin composition and a resin are integrally molded, the cured film is hardly broken, and wear resistance and hardness can be easily imparted to a substrate having a three-dimensional shape. The moldings thus obtained are impacts such as cellular phones, portable music players, portable video players, portable televisions, cameras, videos, portable game machines, personal digital assistants, notebook computers, electronic notebooks, electronic dictionaries, etc. Suitable for portable devices that are susceptible to damage.

Hereinafter, the present invention will be described in detail.
In the present invention, a polyfunctional (meth) acrylate monomer and / or a polyfunctional acrylate oligomer (a) is used. Examples of the polyfunctional acrylate monomer include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate, and dicyclopentanyl. Diacrylate, caprolactone-modified dicyclopentenyl diacrylate, ethylene oxide-modified phosphate diacrylate, allylated cyclohexyl diacrylate, isocyanurate diacrylate, trimethylolpropane triacrylate, dipentaerythritol triacrylate, propionic acid-modified dipentaerythritol triacrylate, Pentaerythritol triacrylate, propylene oxide modified trimethylolpro Down triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol pentaacrylate, propionic acid-modified dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and caprolactone-modified dipentaerythritol hexaacrylate. Moreover, what oligomerized these can be used as the said polyfunctional acrylate oligomer.

  Polyfunctional methacrylate monomers include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol di Methacrylate, 1,10-decanediol dimethacrylate, glycerin dimethacrylate, dimethylol-tricyclodecane dimethacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, and the like. These may be used alone or in combination of two or more. You may mix and use.

  The acrylic polymer (b) substantially free of unsaturated groups, having a weight average molecular weight of 5,000 to 200,000 and a glass transition temperature of 20 to 200 ° C. is styrene, methyl (meth) acrylate, It can be obtained by polymerizing an unsaturated monomer such as ethyl (meth) acrylate, butyl (meth) acrylate, methyl (meth) acrylate and the like. If the glass transition temperature is less than 20 ° C, the hardness decreases, and if it exceeds 200 ° C, the elongation is not sufficient, which is not preferable. A more preferable range of the glass transition temperature is 50 to 150 ° C.

  Moreover, it is preferable that an acrylic polymer has a hydrophilic functional group from the point of abrasion resistance. Specifically, hydrophilic functional groups such as (meth) acrylic acid, itaconic acid, fumaric acid, maleic acid and the like having a carboxyl group, or 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate having a hydroxyl group By copolymerizing an unsaturated monomer having an unsaturated monomer with the unsaturated monomer, a hydrophilic functional group can be introduced into the acrylic polymer.

  The weight average molecular weight of the acrylic polymer needs to be 5,000 to 200,000. When the weight average molecular weight is less than 5,000, the wear resistance is insufficient, and when the weight average molecular weight exceeds 200,000, the moldability and toughness including coating properties are insufficient. A weight average molecular weight can be adjusted with the compounding quantity of a polymerization catalyst and a chain transfer agent, and the kind of solvent to be used.

  The blending ratio of the acrylic polymer is preferably 10 to 900 parts by weight of the acrylic polymer (b) with respect to 100 parts by weight of the total of the polyfunctional (meth) acrylate monomer and / or the polyfunctional acrylate oligomer (a). More preferred are parts by weight. The elongation is remarkably improved by setting it to 10 parts by weight or more, and the hardness can be maintained by setting it to 900 parts by weight or less.

  When the acrylic polymer contains an unsaturated group, the elongation cannot be sufficiently improved. Therefore, the acrylic polymer needs to be substantially free of unsaturated groups. Note that substantially not containing an unsaturated group means that an unsaturated group-containing compound is introduced into the acrylic polymer by a method such as reacting an unsaturated group-containing compound after polymerization of the acrylic polymer. When a partially unreacted unsaturated group remains when the acrylic polymer is polymerized, it is assumed that the unsaturated group is not substantially contained.

  The curable resin composition of the present invention containing the two components can be cured by irradiation with an active energy ray such as an electron beam or ultraviolet ray, but can be cured with high sensitivity by adding a photopolymerization initiator. It becomes possible. Examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, Carbonyl compounds such as benzoin isopropyl ether, sulfur compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, and tetramethylthiuram disulfide can be used. Commercially available products of these photopolymerization initiators include Irgacure 184, 369, 651, 500 (manufactured by Ciba Specialty Chemicals), Lucirin LR8728 (manufactured by BASF), Darocure 1116, 1173 (manufactured by Merck), Ubekrill P36 (UCB) Etc.).

  The resin composition used in the present invention includes various resins such as acrylic resins, urethane resins, styrene resins, phenolic resins, melamine resins, barium hydroxide, magnesium hydroxide, hydroxylated as necessary. In addition to inorganic fillers such as aluminum, silicon oxide, titanium oxide, calcium sulfate, barium sulfate, calcium carbonate, basic zinc carbonate, basic lead carbonate, silica sand, clay, talc, silica compound, titanium dioxide, silanes and titanates Coupling agents such as disinfectants, bactericides, preservatives, plasticizers, flow regulators, antistatic agents, thickeners, pH adjusters, surfactants, leveling agents, antifoaming agents, color pigments, rust preventive pigments, etc. These ingredients may be added. Moreover, you may add an anti-aging agent and a ultraviolet absorber for the purpose of a weather resistance improvement. In addition, it is not preferable to use the above-mentioned compound containing an unsaturated group because problems such as cracks may occur in the coating film.

  The curable resin composition of the present invention can be used as a hard coat film by coating and curing directly on a substrate to form a cured film, or by coating and curing on a film. As the film, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, Polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetherimide film, polyimide film, fluorine resin film, List nylon film, acrylic resin film, etc. Door can be.

  The method for applying the curable resin composition of the present invention is not particularly limited, and known spray coating, dipping, roll coating, die coating, air knife coating, blade coating, spin coating, reverse coating, gravure coating, wire bar, and the like are applied. It can be formed by a construction method or a printing method such as gravure printing, screen printing, offset printing, or ink jet printing. The thickness of the resin layer after hardness is preferably 1 μm to 40 μm. When the thickness of the resin layer is less than 1 μm, it is difficult to obtain sufficient hardness, and when it exceeds 40 μm, cracks are likely to occur.

  A film obtained by applying and curing the curable resin composition of the present invention is suitable for resin integral molding. Specifically, by setting the film in a mold during injection molding and molding it integrally with the injected resin, it is possible to easily form a hard coat layer with a cured film on a three-dimensional substrate. In addition, the cured film is difficult to break.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and demonstrated in detail about this invention, a specific example is shown and it does not specifically limit to these. All the formulations are described based on the solid content.

Example 1
Polyresin urethane acrylate oligomer Artresin UN-905 (trade name, solid content 70%, manufactured by Negami Kogyo Co., Ltd.) 80 parts by weight, glass transition temperature 80 ° C., weight average molecular weight 27000, hydrophilic functional group 20 parts by weight of acrylic polymer 1, 5 parts by weight of Irgacure 184 (trade name, manufactured by Ciba Japan) as a photopolymerization initiator, and 0.5 parts by weight of Tinuvin 152 (trade name, manufactured by Ciba Japan) as an anti-aging agent BYK-310 (trade name, solid content 25%) 0.125 parts by weight as a leveling agent, methyl ethyl ketone as a solvent was added so as to have a solid content of 30%, and the mixture was mixed. A curable resin composition was obtained.

Examples 2-12, Comparative Examples 1-5
In addition to the compounding materials used in Example 1, dipentaerythritol hexaacrylate (A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd., trade name, solid content 100%), which is a hexafunctional acrylate monomer, is a polyfunctional urethane acrylate oligomer. Art Resin UN-904M (manufactured by Negami Kogyo Co., Ltd., trade name, solid content 80%), acrylic polymers 2 to 9 (each having a hydrophilic functional group, glass transition temperature (Tg) and weight average molecular weight (Mw) ) Is the composition shown in Table 1 and Table 2 using Table 2) (all expressed in parts by weight based on solid content), and similarly, methyl ethyl ketone as a solvent is added and mixed so that the solid content is 30%. Thus, each curable resin composition was prepared. Each curable resin composition was evaluated by the following method.

Preparation of test body Each curable resin composition was applied to a PET film having a thickness of 100 μm (trade name Lumirror 100U34, manufactured by Toray Industries, Inc.) so that the film thickness after curing was 5 μm and dried at 80 ° C. for 2 minutes. A film was prepared by UV curing at 200 mJ / cm ² with a high-pressure mercury lamp.

Adhesion Adhesion was evaluated based on the provisions of JIS K 5600-5-6. The case where there was no separation at all was rated as “◯”, and the case where there was some separation was evaluated as “×”.

Pencil hardness Pencil hardness was measured based on JIS K 5600-5-4. The measuring apparatus used was a pencil scratch coating film hardness tester (type P) manufactured by Toyo Seiki Seisakusho. A hardness of 2H or higher was evaluated as ◎, a hardness of H was evaluated as ◯, and a hardness of F or lower was evaluated as ×.

A test body was prepared by cutting an extensible film into a length of 110 mm and a width of 25 mm. In an atmosphere of 150 ° C., the specimen was pulled under the conditions of a distance between chucks of 50 mm and a crosshead speed of 100 mm / min, and the elongation rate until the cured resin layer was cracked was measured. Those having an elongation of 50% or more were evaluated as ◎, those having an elongation of 10% or more and less than 50% were evaluated as ◯, and those having an elongation of less than 10% were evaluated as ×.

  Each curable resin composition of the Examples was excellent in adhesion, hardness, and elongation. On the other hand, when the acrylic polymer having a predetermined property was not contained, the elongation was poor, and when the polyfunctional (meth) acrylate was not contained, the adhesion and hardness were poor.

Claims (5)

  The polyfunctional (meth) acrylate monomer and / or the polyfunctional acrylate oligomer (a) is substantially free of unsaturated groups, has a weight average molecular weight of 5,000 to 200,000, and a glass transition temperature of 20 to 200. A curable resin composition comprising an acrylic polymer (b) at a temperature of ° C.   The acrylic polymer (b) is blended in an amount of 10 to 900 parts by weight per 100 parts by weight of the polyfunctional (meth) acrylate monomer and / or the polyfunctional acrylate oligomer (a). Curable resin composition.   The curable resin composition according to claim 1 or 2, wherein the acrylic polymer (b) has a hydrophilic functional group.   A film, wherein the curable resin composition according to claim 1 is applied and cured.   A resin molding method comprising: setting the film according to claim 4 in a mold, and integrally molding the film and the resin at the time of injection molding.