JP5033450B2 - Hard coat agent and hard coat film - Google Patents

Description

  The present invention relates to a hard coat agent and a hard coat film.

  In the fields of home appliance touch panels, automobile interior panels, mobile phone bodies, keypads, and the like, a hard coat layer is formed to prevent the outermost surface from being damaged.

  In particular, for the formation of the hard coat layer on the two-dimensional and three-dimensional curved surface portions, only the hard coat layer from the film having the hard coat layer or the insert molding to be integrated with the resin by injection molding simultaneously with the film having the hard coat layer In-mold molding in which heat transfer is performed to a molded product.

The formation of the hard coat layer will be described in detail. A system in which a hard coat agent is applied to a plastic film and dried, and then irradiated with radiation such as an electron beam or ultraviolet ray as necessary is cured.
JP 2000-103987 A JP 2001-162732 A JP 2002-67238 A JP 2002-69333 A JP 2004-346228 A JP 2001-113649 A JP 2003-170540 A

  In general, the material of the hard coat layer remains tacky before irradiation, becomes tack-free only after irradiation, and can increase the hardness of the surface. However, when irradiated with radiation, the cross-linking density of the coating film becomes high, and the coating film becomes brittle, so that there is a problem that cracks occur at the curved surface portion during molding.

  Therefore, if a radiation curable resin that is tack-free at room temperature is used for the hard coat layer, cracks do not occur because it is not completely crosslinked during molding, and the surface hardness can be increased by irradiating with radiation after molding. It becomes possible.

  Although some acrylic acrylate resins and urethane acrylate resins are known as tack-free resins, the coating film before irradiation is eroded by the solvent, and the hardness after irradiation is inferior, and scratches are likely to occur. Had the disadvantages.

  In addition, the addition of a polyfunctional acrylate monomer or the like to the tack-free resin can improve the surface hardness and scratch resistance after irradiation, but in general, the polyfunctional acrylate monomer has a tack after drying, so a sufficient surface can be obtained. In order to obtain hardness and scratch resistance, there is a problem that tack-free property is lost.

The present invention has been made in view of the above points, and is a hard coat agent and hard coat that are tack-free by using the heat of a drying furnace and have excellent solvent resistance and high surface physical properties after radiation irradiation. The object is to provide a film.
That is, the invention described in claim 1 is a hard coat agent containing the following main agent and curing agent.
A) Main agent A colloidal silica-containing monomer in which an acrylate monomer or an acrylate oligomer, a compound containing a (meth) acryloyl group and an isocyanate group in the molecule, and colloidal silica are urethane-bonded.
B) Curing agent Multifunctional isocyanate.

  The invention according to claim 2 is an isocyanate compound in which the colloidal silica-containing monomer has two or more isocyanate groups in the molecule and a polymerizable unsaturated group is introduced into at least one or more isocyanate groups. The hard coat agent according to claim 1, wherein urethane colloidal silica and colloidal silica are bonded.

  The invention according to claim 3 is the hard coat agent according to claim 1 or 2, wherein the introduction of the polymerizable unsaturated group into the isocyanate group is a reaction of an isocyanate group and a hydroxyl group.

  The invention according to claim 4 is the hard coat agent according to claim 1, 2 or 3, characterized in that the main agent contains a silane coupling agent.

  Furthermore, the invention described in claim 5 is a hard coat film obtained by applying the hard coat agent to a plastic film.

  The hard coat agent of the present invention has no tack after being applied to a plastic film and dried, has excellent solvent resistance, and can form a hard coat layer having excellent surface hardness after irradiation with radiation. A hard coat agent mixed with a polyfunctional isocyanate and a colloidal silica-containing monomer with a (meth) acryloyl group introduced via a urethane bond on the surface of the colloidal silica is applied onto the plastic film, and heat is applied using the heat generated during drying. When cross-linked, it becomes completely tack-free and, after irradiation, has excellent surface properties and solvent resistance.

  In addition, the pot life after mixing can be extended by using the reaction of the colloidal silica-containing monomer and the silane coupling agent in combination.

  Hereinafter, the present invention will be described in detail.

  The colloidal silica used in the present invention is not particularly limited, and various commercial products having an average particle diameter of 100 nm or less and an organic solvent as a dispersion medium can be used. When colloidal silica having a larger particle diameter is used, not only the storage stability is deteriorated, but also the desired surface hardness and scratch resistance intended in the present invention cannot be expressed at the same time, and the resulting cured product is obtained. There are problems such as cloudiness. Those having an average particle diameter of 5 to 50 nm are more preferred.

  Examples of the compound containing a (meth) acryloyl group and an isocyanate group used in the present invention include acryloyl isocyanate, methacryloyl isocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, and 2-methacryloyloxyethyl isocyanate.

  An isocyanate compound having two or more isocyanate groups in the molecule and having a polymerizable unsaturated group introduced into at least one isocyanate group is a (meth) acryloyl group, an allyl group, a homoallyl group and styrene in the molecule. A compound having at least one group selected from the group consisting of groups and at least one isocyanate group, such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene; Diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate 4 4'-diphenylmethane triisocyanate, 3,3'-dimethylphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, methylenebis (4-cyclohexylisocyanate), 2,2,4-trimethylhexa Methylene diisocyanate, bis (2-isocyanatoethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, tolidine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, 2 , 5 (or 6) -bis (isocyanatomethyl) -bicyclo [2.2.1] heptane, triethylenediiso Anate trimethylolpropane adduct, triethylene diisocyanate isocyanurate, diphenylmethane-4,4'-diisocyanate oligomer, hexamethylene diisocyanate biuret, hexamethylene diisocyanate isocyanurate, hexamethylene diisocyanate uretdione, isophorone diisocyanate The isocyanurate body etc. are mentioned. Moreover, these polyisocyanates can be used individually or in combination of 2 or more types.

  Examples of the compound having a polymerizable unsaturated group introduced into at least one isocyanate group of the polyisocyanate include trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, and trimethylolpropane ethylenoxy. Side addition triacrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4 -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (Meth) acrylate, Bisphenol A diglycidyl ether end (meth) acrylic acid adduct, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) Isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, bisphenol A ethyleneoxycide or propylene oxide adduct di (meth) ) Di (meth) acrylate of acrylate, hydrogenated bisphenol A ethylene oxide or propylene oxide adduct diol, diglycidyl ether of bisphenol A (meta Acrylate added was epoxy (meth) acrylate, triethylene glycol divinyl ether.

  Further, hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, polyethylene glycol acrylate, (meth) acrylic acid, itaconic acid, cinnamic acid, maleic acid, fumaric acid, 2 -Unsaturated aliphatic carboxylic acids such as (meth) acryloxypropyl hexahydrogen phthalate, 2- (meth) acryloxyethyl hexahydrogen phthalate, 2- (meth) acryloxypropyl phthalate , Unsaturated aromatic carboxylic acids having a carboxyl group such as 2- (meth) acryloxypropylethyl phthalate, vinyloxyethylamine, vinyl oxide decylamine, allyloxypropylamine, 2-methylallyloxyhexyl Amino, amino group-containing monomers such as vinyloxy- (2-hydroxy) butylamine, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 9,10-epoxystearyl (meth) acrylate, methylglycidyl ( And epoxy group-containing monomers such as (meth) acrylate.

  These compounds having a polymerizable unsaturated group can be used alone or in combination of two or more.

  In order to promote the reaction for introducing a polymerizable unsaturated group into the polyisocyanate and the reaction between the colloidal silica and the isocyanate group, a catalyst may be added. For example, copper naphthenate, cobalt naphthenate, zinc naphthenate, di-n-butyltin laurate, bis (di-n-butyltin fatty acid salt) oxide, triethylamine, 1,4-diazabicyclo [2.2.2] octane, It is preferable to use 0.01 to 1 part by weight of a urethanization catalyst such as 2,6,7-trimethyl-1,4-diazabicyclo [2.2.2] octane with respect to 100 parts by weight of the total amount of the reactants.

  In addition, in the reaction between the isocyanate group and colloidal silica, methyl alcohol, ethyl alcohol, isopropyl alcohol, etc. are used to block the excess isocyanate group while confirming the reaction of the isocyanate group by infrared absorption spectroscopy (IR) or the like. These alcohols and compounds capable of reacting with the isocyanate groups may be added.

  As the polyfunctional isocyanate that is mixed with the colloidal silica-containing monomer and further reacted with heat during drying, the same isocyanates as those described above can be applied.

  The silane coupling agent used for mixing with the above colloidal silica-containing monomer, further reacting with heat during drying, and extending the pot life is specifically γ-glycidoxypropyltrimethoxysilane, γ -Epoxy silanes such as glycidoxypropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxy Aminosilanes such as silane, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane and other vinylsilanes, γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ -Metacloxip Examples include methacryloxysilane such as propyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. The silane coupling agent is 1 wt% to 40 wt%, more preferably 2 wt% to 22 wt% in the main component solid content. It is presumed that the pot life becomes longer because the silanol reaction is slower than the urethane reaction with isocyanate, so that the life after mixing is extended.

  Mixing of acrylate monomers or acrylate oligomers, isocyanate compounds and the like with colloidal silica-containing monomers is preferably carried out in solution, and the solvents used are ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ethyl acetate Further, ester solvents such as butyl acetate and carbitol acetate, ether compounds such as dibutyl ether, and alcohol solvents such as n-butanol and isobutanol can be used. A mixed solvent of the above solvents can also be used. Further, a radical polymerizable monomer may be used in place of the solvent.

  The blending ratio of the acrylate monomer, acrylate oligomer, isocyanate compound, and the like and the colloidal silica-containing monomer is mixed after mixing, that is, so that the silica ratio to the total solid content of the main agent and the curing agent is 2 to 11 wt%. Desirably, the hardness is inferior if the lower limit is not reached, and the tack-free property and the solvent resistance are inferior if the upper limit is exceeded.

  The hard coating agent of the present invention includes acrylic resin, urethane resin, styrene resin, melamine resin, barium hydroxide, magnesium hydroxide, aluminum hydroxide, silicon oxide, titanium oxide, calcium sulfate as necessary. In addition to inorganic fillers such as barium sulfate, calcium carbonate, basic zinc carbonate, basic lead carbonate, silica sand, clay, talc, silica compounds, titanium dioxide, bactericides, preservatives, plasticizers, flow regulators, increase You may add compounding materials, such as a viscosity agent, a pH adjuster, surfactant, a leveling adjuster, an antifoamer, a color pigment, and a rust preventive pigment. Moreover, you may add antioxidant and a ultraviolet absorber for the purpose of light resistance improvement.

  In addition, an antistatic agent, an ionic liquid, a conductive polymer, or conductive fine particles can be added as a blending material.

  Examples of the polymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2- Methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-c Rothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) ) -2,4,4-trimethylpentylphosphine oxide and the like, and as commercial products, trade names Irgacure 184, 369, 651, 500, 907, 127, 2959, CGI 1700, CGI 1750, CGI 1850, CG 24-61 (or more) Trade name Lucirin LR8728 (manufactured by BASF); Darocure 1116 and 1173 (manufactured by Merck & Co., Inc.); trade name Ubekrill P36 (manufactured by UCB), and the like. Other examples include peroxides and azobis compounds. Examples of peroxides include dibutyl peroxide, benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, and the like. Examples of azobis compounds include 2,2′- Azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis (2-methylpropionamidine) dihydro Examples include chloride.

  It is also possible to use a photocuring accelerator in combination, such as ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 2-n-ptoxyethyl p-dimethylaminobenzoate, 2-dimethylaminobenzoate. And ethyl.

  Furthermore, examples of the initiator for photocationic polymerization include diallyliodonium salts and triarylsulfonium salts.

  Examples of the plastic film include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, and 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 , Nylon film, acrylic resin fill And the like can be given.

  For the purpose of improving adhesion with hard coat agent, surface unevenness treatment by sandblasting method or solvent treatment method, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, etc. Surface treatment such as oxidation treatment of the surface can be performed.

  There is no restriction | limiting in particular about the coating method to a film, For example, a well-known method, for example, a gravure coat method, a bar coat method, a knife coat method, a roll coat method, a blade coat method, a die coat method etc. can be used. The coating thickness is applied so as to be 1 to 20 μm after curing and is dried.

When irradiating with ultraviolet rays, use an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a metal halide lamp, etc., and have an energy of 50 to 300 mJ / cm ² in a wavelength region of 100 to 400 nm, preferably 200 to 400 nm. Irradiate ultraviolet rays. In order to prevent curing inhibition, irradiation may be performed under an inert gas such as nitrogen gas.

  When irradiating an electron beam, a scanning or curtain type electron beam accelerator is used, and the irradiation dose is preferably 10 kGy to 200 kGy, and more preferably 30 kGy to 100 kGy. If it is less than 10 kGy, complete curing cannot be achieved, and if it exceeds 200 kGy, the life of the electron beam irradiation tube is remarkably shortened, which is not economical. Moreover, although an acceleration voltage is set with the coating-film thickness and density which are provided on a base material, 50 kv to 300 kv, Furthermore, 150 kv-250 kv are more preferable.

  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.

1) Colloidal silica-containing monomer MEK solvent-dispersed colloidal silica (MEK-ST, solid content 30%, average particle size of about 20 nm / manufactured by Nissan Chemical Industries, Ltd.) 84 parts by weight, 2-methacryloyloxyethyl isocyanate (solid 100%) 11 parts by weight, MEK 15 parts and 0.16 parts by weight of bis (di-n-butyltin fatty acid salt) oxide as a catalyst were added and stirred at 70 ° C. for 2 hours. After cooling, 0.5 parts by weight of isopropyl alcohol was added to react all isocyanate groups, and it was confirmed by infrared absorption spectroscopy that there were no remaining isocyanate groups, solid content 36%, silica content 70% (in solid content) The colloidal silica-containing monomer was obtained.
2) Hard coat agent A) Main agent 50 parts by weight of epoxy acrylate represented by Chemical Formula 1 (trade name: 80MFA, manufactured by Kyoeisha Chemical Co., Ltd., solid content: 100%) with respect to 100 parts by weight of the above colloidal silica-containing monomer -25 parts by weight of acryloxypropyltrimethoxysilane (trade name: AY-43-310M, manufactured by Toray Dow Corning Co., Ltd.), butyltin compound as a curing catalyst (trade name: SCAT-1, manufactured by Sansha Co., Ltd.) 1 part by weight, 10 parts by weight of Irgacure 184 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.) as an initiator was added, and MEK was added to obtain a main component so that the solid content was 40%.

B) Curing agent An adduct of trimethylolpropane and xylylene diisocyanate as a polyfunctional isocyanate (trade name Takenate D-110N, manufactured by Mitsui Chemicals Polyurethanes Co., Ltd., solid content: 75%) MEK was added to obtain a curing agent.
3) Hard coat film A and B were mixed at a weight ratio of 1: 1, stirred for 30 minutes, then applied to a 100 μm PET (polyethylene terephthalate) film by a bar coat method so that the cured film thickness was 5 μm, and then dried with hot air Drying was performed at 100 ° C. for 2 minutes in a vessel. Rub with methanol wiped Kimwipe (registered trademark holder Kimberley Clark Worldwide Inc.) to check solvent resistance and tack-free by finger erosion, and then UV irradiation device (Fusion UV Systems Japan) A hard coat film was obtained by irradiating ultraviolet rays with an integrated light quantity of about 200 mJ / cm ² using a fusion lamp manufactured by Co., Ltd.

Examples 2-7
The main agent and the curing agent prepared by each formulation shown in Table 1 were mixed at a weight ratio of 1: 1, and the same procedure as in Example 1 was performed.

Example 8
Examples of Table 1 using non-yellowing polyisocyanate having an isocyanurate bond made from hexamethylene diisocyanate (HDI) as a polyfunctional isocyanate (trade name: Coronate HX, manufactured by Nippon Polyurethane Industry Co., Ltd., solid content: 100%) 8 was carried out in the same manner as in Example 1.

Comparative Example 1
527 parts by weight of acrylate (trade name Hitaroid 7975, manufactured by Hitachi Chemical Co., Ltd., solid content 32%) as a tack-free resin, and 10 parts by weight of Irgacure 184 (trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.) as an initiator Was applied to a 100 μm PET (polyethylene terephthalate) film by a bar coating method so as to have a cured film thickness of 5 μm, and dried in a hot air dryer at 100 ° C. for 3 minutes. After rubbing with a methanol-impregnated Kim wipe and confirming solvent resistance, and after confirming tack-free properties by finger erosion, use an ultraviolet irradiation device (Fusion UV Systems Japan Co., Ltd., fusion lamp) to irradiate ultraviolet rays. A hard coat film was obtained by irradiation with an integrated light amount of about 200 mJ / cm ² , but the pencil hardness, scratch resistance and solvent resistance were poor.

Comparative Example 2
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 2 of Table 1, the tack remained and the solvent resistance was also inferior.

Comparative Example 3
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 3 of Table 1, pencil hardness and abrasion resistance were inferior.

Comparative Example 4
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 4 of Table 1, the solvent resistance was inferior.

Comparative Example 5
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 5 of Table 1, pot life property was inferior and the pot life was short.

Comparative Example 6
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 6 of Table 1, when it applied and there were many foreign materials, it was poor in external appearance.

Comparative Example 7
Although it implemented similarly to Example 1 by the mixing | blending shown in the comparative example 7 of Table 1, it gelled after mixing.

Comparative Example 8
Although it carried out similarly to Example 1 by the mixing | blending shown in the comparative example 8 of Table 1 using the isocyanate group containing urethane acrylate (Brand name HNF-1, Negami Industrial Co., Ltd. make, solid content 100%) as monofunctional isocyanate. The tack remained and the chemical resistance was poor.

  The evaluation results are shown in Table 1.

Evaluation methods and evaluation results were as follows.
1) Pot life: After mixing the main agent and curing agent, visually confirm the time during which gelation and coating cannot be performed. ○: Can be applied even after 7 hours or more. Δ: Cannot be applied in 5-7 hours. ×: Cannot be applied in less than 5 hours.
2) Tack: A hard coat agent is applied, dried at 100 ° C. for 3 minutes, and then touched with an index finger to determine.
○: No tackiness is felt, Δ: Almost no tackiness, ×: Stickiness is felt
3) Pencil hardness: Conforms to JIS K5400. A scratch test was performed by applying a load of 1 kg from directly above a pencil fixed at an angle of 45 degrees.
4) Scratch resistance: Check whether steel flaw # 0000 (manufactured by Nippon Steel Wool Co., Ltd.) is rubbed 10 reciprocally at a load of 200 g and whether or not it is damaged.
○: No scratches are observed. Δ: Ten scratches are entered from 1: ×: Ten or more scratches are entered.
5) Solvent resistance: rubbing with kimwipe soaked in methanol to confirm traces.
○: No trace left, △: Little trace left, ×: Trace left

Claims (5)

A hard coat agent containing the following main agent and curing agent.
A) Main agent A colloidal silica-containing monomer in which an acrylate monomer or an acrylate oligomer, a compound containing a (meth) acryloyl group and an isocyanate group in the molecule, and colloidal silica are urethane-bonded.
B) Curing agent Multifunctional isocyanate.   The colloidal silica-containing monomer has two or more isocyanate groups in the molecule, and at least one isocyanate group having a polymerizable unsaturated group introduced therein and colloidal silica are urethane-bonded. The hard coat agent according to claim 1, wherein   The hard coat agent according to claim 1 or 2, wherein the introduction of the polymerizable unsaturated group into the isocyanate group is performed by a reaction between an isocyanate group and a hydroxyl group.   The hard coat agent according to claim 1, wherein the main agent contains a silane coupling agent. A hard coat film obtained by applying the hard coat agent to a plastic film.