JP2018051918A - Hard coat film for transfer, hard coat laminate, and method of manufacturing hard coat laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard coat film for transfer which is excellent in scratch resistance and processing characteristics, a hard coat laminate using the film, and a method of manufacturing a hard coat laminate.SOLUTION: At least a hard coat layer 12, a primer layer 13, and a heat seal layer 14 are arranged in this order on a substrate film 11. The hard coat layer 12 contains: a first cured product of a urethane acrylate in an amount of more than 50% by mass ratio in a resin in the hard coat layer 12; and a blocked isocyanate. The blocked isocyanate preferably has a blocked isocyanate group in a urethane skeleton.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transfer hard coat film, a hard coat laminate, and a method for producing a hard coat laminate.

  Conventionally, in a transfer hard coat film used for laminating a hard coat layer on a resin molded product, vigorous studies have been conducted in order to improve its functionality. For example, Patent Document 1 discloses a decorative sheet in which at least a base material layer, a primer layer, and a surface protective layer are laminated in this order as a film that can be used as a transfer hard coat film. It is described that the surface protective layer may contain blocked isocyanate and ionizing radiation curable resin (such as polycarbonate (meth) acrylate and a small amount of urethane (meth) acrylate).

Japanese Patent Laying-Open No. 2015-19311

  However, a conventional hard coat film for transfer containing an ionizing radiation curable resin can be inferior in processing characteristics such as bendability, although a hard coat excellent in scratch resistance and the like can be obtained by ionizing radiation curing.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a hard coat film for transfer excellent in scratch resistance and processing characteristics, a hard coat laminate using the film, and a hard coat laminate. To do.

  As a result of intensive studies by the present inventors to solve the above problems, at least a hard coat layer, a primer layer, and a heat seal layer are arranged in this order on the base film. In the film, when the heat-sealed layer contains a predetermined amount of a cured product of urethane acrylate and a cured product derived from blocked isocyanate, and these cured products are bonded via allophanate bonds, the above-mentioned problem It was found that can be solved. More specifically, the present invention provides the following.

(1) On the base film, at least a hard coat layer, a primer layer, and a heat seal layer are arranged in this order,
The said hard-coat layer is a hard-coat film for transcription | transfer containing the 1st hardened | cured material of urethane acrylate exceeding 50% by mass ratio in resin in this hard-coat layer, and block isocyanate.

  (2) The hard coat film for transfer according to (1), wherein the blocked isocyanate has a blocked isocyanate group in a urethane skeleton.

  (3) The hard coat film for transfer according to (1) or (2), wherein the hard coat layer further contains a curing catalyst.

(4) On the resin substrate, at least a heat seal layer, a primer layer, and a hard coat layer are arranged in this order,
The hard coat layer includes a first cured product of urethane acrylate having a mass ratio in the resin of more than 50% and a second cured product of blocked isocyanate, and the first cured product, the second cured product, Is a hard coat laminate bonded through allophanate bonds.

(5) A method for producing a hard coat laminate in which at least a heat seal layer, a primer layer, and a hard coat layer are arranged in this order on a resin substrate,
At least a hard coat layer, a primer layer, and a heat seal layer are laminated in this order. In the hard coat layer, urethane acrylate having a mass ratio in the resin in the hard coat layer of more than 50%, and blocked isocyanate And a laminate forming step containing:
An ionizing radiation curing step in which the hard coat layer is cured by ionizing radiation to form a first cured product of the urethane acrylate during or after the laminate forming step,
On the resin substrate, a transfer layer after the ionizing radiation curing step is transferred through the heat seal layer to obtain a resin substrate with a hard coat layer, and
After the transfer step, by bending the resin substrate with hard coat layer while heating, or by heating after bending the resin substrate with hard coat layer, the second cured product of the blocked isocyanate, and A heat bending step of forming an allophanate bond via the first cured product and the second cured product;
A method for producing a hard coat laminate comprising:

  The present invention can provide a hard coat film for transfer excellent in scratch resistance and processing characteristics, a hard coat laminate using the film, and a method for producing the hard coat laminate.

It is a cross-sectional schematic diagram which shows an example of the hard coat film for transfer of this invention. It is an example of the hard coat laminated body of this invention, Comprising: It is a cross-sectional schematic diagram which represents the form of the state before peeling (a) base film, and the form of the state which peeled (b) base film, respectively. is there.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. The present invention can be implemented with appropriate modifications within the scope of the object.

<Hard coat film for transfer>
The configuration of the transfer hard coat film of the present invention will be described below with reference to FIG. In the transfer hard coat film 10 of the present invention, a transfer layer 15 in which at least a hard coat layer 12, a primer layer 13, and a heat seal layer 14 are arranged in this order is laminated on a base film 11. The “arranged in this order” in the present invention means not limited to a configuration in which only the base film 11, the hard coat layer 12, the primer layer 13, and the heat seal layer 14 are laminated. For example, the transfer hard coat film 10 may be laminated with other layers in addition to the base film 11 and the transfer layer 15 as long as the effects of the present invention are not hindered. Examples of other layers include the base film 11 and the hard coat layer 12, the hard coat layer 12 and the primer layer 13, the primer layer 13 and the heat seal layer 14, and the heat seal layer 14. A partially formed colored layer (decorative layer) is disposed on at least one of the surfaces on the opposite side to the primer layer 13 side for the purpose of concealment, information display, designability, etc. It may be.

[Base film]
The base film 11 serves as a support base material that supports the transfer layer 15, and is a layer that is peeled off after the transfer layer 15 is transferred to a resin substrate (described later) that is a transfer target.

  The constituent resin constituting the base film 11 is not particularly limited as long as it can be used as a supporting base and can peel the transfer layer 15. For example, the constituent resin may be constituted by a polyester resin film or a polyolefin resin film. preferable. The film is more preferably a stretched film. By constituting the base film 11 with these films, shrinkage caused by heat treatment or cross-linking treatment by irradiation of ionizing radiation when producing the transfer hard coat film 10 is suppressed, and the transfer hard coat film 10 and the stability of the shape and dimensions of the hard coat laminate 1 can be easily improved.

  Preferred examples of the polyester resin film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyarylate, polycarbonate, and ethylene terephthalate-isophthalate copolymer. Can be mentioned. Among these, PET and PBT are preferable, and PET is particularly preferable in consideration of heat shrinkage at the time of manufacturing the transfer hard coat film 10 and shrinkage due to irradiation with ionizing radiation.

  As the polyolefin resin film, in consideration of heat shrinkage at the time of producing the transfer hard coat film 10 and shrinkage due to irradiation of ionizing radiation, for example, polyethylene resin, polypropylene resin, polybutene resin, ethylene / propylene Preferred is a stretched resin film made of a polyolefin resin such as a copolymer resin, an ethylene / propylene / butene copolymer resin, or an olefin thermoplastic elastomer. Of these, a stretched polypropylene resin film is preferable.

  The stretched polyolefin resin may be either uniaxially stretched or biaxially stretched, but in consideration of the fact that heat shrinkage during production of a transfer hard coat film and shrinkage due to irradiation of ionizing radiation are less likely to occur. Biaxially stretched is preferable. The biaxially stretched polyolefin resin sheet is usually heated to a glass transition temperature Tg or higher using a longitudinal stretching machine, preferably stretched by about 5 to 30 times, and then glass is stretched using a width stretching machine. It is obtained by heating above the transition temperature Tg and stretching in the width direction, preferably 5 times or more and 30 times or less. Moreover, when the draw ratio is within the above range, thermal shrinkage during production of the transfer hard coat film 10 and shrinkage due to irradiation of ionizing radiation are less likely to occur.

  Although the thickness of the base film 11 is not specifically limited, What is necessary is just 4 micrometers or more and 200 micrometers or less. If it is 4 μm or more, curls and wrinkles are difficult to enter, and if it is 200 μm or less, the cost can be kept low, the heat conduction efficiency does not decrease, and each layer is difficult to peel off when the base film 11 is peeled after transfer. Therefore, excellent transferability can be obtained. The base film 11 may have a multilayer structure. In that case, it is preferable that it exists in the range of the said thickness with the whole multilayer structure.

  In addition, in order to ensure the mold release property between the base film 11 and the hard coat layer 12 at the time of transfer, the surface of the base film 11 is subjected to a known mold release treatment as necessary, or a silicone resin. A release layer such as the above may be provided. Conversely, in order to improve the adhesion between the base film 11 and the hard coat layer 12, corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment, and easy adhesion coating agent are used. A surface treatment such as coating may be performed. Moreover, the base film 11 may be a single layer using the above resin film alone, or may have a multilayer structure in which a plurality of types of resin films are laminated.

[Hard coat layer]
The hard coat layer 12 is a layer made of a cured product of a curable resin composition, and is transferred to a resin substrate that is a transfer target via the heat seal layer 14, and then positioned on the outermost surface, and resin molding. It plays a role of imparting hard coat properties (scratch resistance) to a hard coat laminate as a product. The hard coat layer in the present invention is characterized by containing a first cured product of urethane acrylate having a mass ratio of more than 50% in the hard coat layer and a blocked isocyanate.

  Usually, hard coats obtained from ionizing radiation curable resins (hereinafter referred to as “ionizing radiation curable hard coats”) are excellent in weather resistance, chemical resistance, etc., but they are processed such as bendability. Inferior in characteristics. In order to impart processing characteristics to the ionizing radiation curable hard coat, it is necessary to reduce the crosslinking density of the resin constituting the hard coat layer. However, if the crosslink density of the resin is low, the scratch resistance of the hard coat also decreases, so that it is difficult to produce an ionizing radiation curable hard coat having excellent scratch resistance and processing characteristics.

  Therefore, as a result of the study by the present inventors, by adjusting the composition of the hard coat layer, the bending property is improved without sufficiently proceeding with the crosslinking of the resin at the time of ionizing radiation curing, or after the bending process or the bending process. At the same time, it was found that crosslinking can be advanced by heat treatment to impart scratch resistance to the ionizing radiation curable hard coat.

  Specifically, the operation of the present invention can be explained as follows. When the hard coat layer containing the urethane acrylate that is an ionizing radiation curable resin and the blocked isocyanate is cured with ionizing radiation, the curability of the urethane acrylate is lowered at the stage of ionizing radiation curing, although the reason is not clear. The cured product of urethane acrylate at the time is referred to as “first cured product of urethane acrylate”). Thereby, although it is after ionizing radiation hardening, compared with the case where block isocyanate does not exist, the crosslinking density of resin is low and a bending characteristic is high. Next, when the cured product is subjected to processing such as heat bending, the blocked isocyanate of the blocked isocyanate is removed by heating (regeneration of the active isocyanate group), and the released active isocyanate group is self-crosslinked to increase the crosslinking density (this The self-crosslinked product of the blocked isocyanate generated at this point is referred to as “second cured product of blocked isocyanate”). As a result, the obtained ionizing radiation curable hard coat layer has sufficient hardness and scratch resistance while having excellent processing characteristics. Further, the present invention is characterized in that an activated isocyanate group derived from a blocked isocyanate and a urethane bond derived from an ionizing radiation curable resin react to form an allophanate bond (the bond is referred to as “the first cured product and the first cured product”). 2) Allophanate bond via cured product. The presence of the bond can ultimately give the ionizing radiation-curable hard coat layer the same hardness as when urethane acrylate is cured in the absence of blocked isocyanate, so without sacrificing the hardness. Bending characteristics can be improved.

  The above action is advantageous compared to the case where a hydroxyl group-containing resin such as a polyol resin (acrylic polyol or the like) is used instead of urethane acrylate. This is because the hydroxyl group-containing resin can be molded by heating in a short time, but the crosslinking rate is fast and the hardness of the reaction product increases rapidly. For this reason, it is suitable for short-time heating of injection molding, but in long-time heating such as heat bending of a resin substrate, the crosslinking reaction is too fast and it is difficult to use it for heat bending or the like. On the other hand, in the present invention, the rate of increase in crosslink density can be suppressed by the formation of allophanate bonds via the first cured product and the second cured product as described above, so that it can be used for heat bending processing and the like. A cured product having excellent bending properties of the resin substrate can be obtained.

  In addition, the allophanate bond through the 1st hardened | cured material and the 2nd hardened | cured material in the hard-coat layer 12 can be detected by infrared spectroscopy (IR), a nuclear magnetic resonance method (NMR), etc.

(Curable resin)
The hard coat layer 12 includes urethane acrylate exceeding 50% by mass ratio in the resin in the hard coat layer. The blending amount of urethane acrylate in the hard coat layer is preferably 80% or more, and most preferably 100% in terms of the mass ratio in the resin in the hard coat layer. The curable resin other than urethane acrylate contained in the hard coat layer is not particularly limited. For example, polyester resin, epoxy resin, polyurethane resin, amino alkyd resin, melamine resin, guanamine resin, urea resin, thermosetting acrylic Examples of the resin include ionizing radiation curable resins other than urethane acrylate. From the viewpoint that particularly good scratch resistance and processing characteristics can be imparted to the hard coat laminate obtained from the transfer hard coat film, the curable resin contained in the hard coat layer is preferably made of an ionizing radiation curable resin, It is particularly preferable that it is made of urethane acrylate.

  An ionizing radiation curable resin is a curable resin that cures when irradiated with ionizing radiation. As the ionizing radiation, electromagnetic waves or charged particle beams having an energy quantum capable of polymerizing or cross-linking molecules, for example, ultraviolet rays (UV) or electron beams (EB), X-rays, γ-rays, etc. Charged particle beams such as electromagnetic waves, α rays and ion beams are also used.

  The ionizing radiation curable resin that can be used for the hard coat layer 12 is appropriately selected from polymerizable oligomers (prepolymers) and polymerizable polymers that are conventionally used as ionizing radiation curable resins. From the viewpoint of obtaining good curing characteristics, it is difficult to bleed out, has a coating property even if it is about 95% or more and 100% or less as a solid content standard, and is cured when the hard coat layer 12 is formed by curing. Those that are less likely to shrink are preferred.

  As the polymerizable oligomer, an oligomer having a radically polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate type, urethane (meth) acrylate type, polyether type urethane (meth) acrylate, and caprolactone type urethane (meth) Preferred examples include acrylate, polyester (meth) acrylate and polyether (meth) acrylate oligomers, and urethane (meth) acrylate is more preferred. The (meth) acrylate means acrylate or methacrylate.

  Among these oligomers, polyfunctional polymerizable oligomers are preferred, and the number of functional groups is preferably 2 or more and 15 or less from the viewpoint of imparting scratch resistance due to high crosslink density, and 2 or less and 8 or less from the viewpoint that curing shrinkage hardly occurs. More preferably, it is 2 or more and 6 or less.

  Examples of the monofunctional polymerizable oligomer include, for example, caprolactone urethane (meth) acrylate obtained by reaction of caprolactone polyol, organic isocyanate and hydroxy (meth) acrylate, and (meth) acrylate on the side chain of the polybutadiene oligomer. High molecular hydrophobic urethane (meth) acrylates such as polybutadiene (meth) acrylate having high hydrophobicity with a group can be mentioned.

  Examples of the polymerizable polymer include polymers having radically polymerizable unsaturated groups in the molecule, such as epoxy (meth) acrylate, urethane (meth) acrylate, polyether urethane (meth) acrylate, and polycaprolactone urethane (meta ) Acrylate, polyester (meth) acrylate-based, polyether (meth) acrylate-based polymers, and the like are preferable, and polycaprolactone-based urethane (meth) acrylate or urethane (meth) acrylate-based is more preferable. The (meth) acrylate means acrylate or methacrylate. These polymers may be used alone or in combination.

(Block isocyanate)
Blocked isocyanate is a compound in which an active isocyanate group of an isocyanate compound is protected with a blocking agent. Since the blocked isocyanate functions as a crosslinking agent, the above isocyanate compound has two or more isocyanate groups in one molecule. A block isocyanate may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the blocked isocyanate of the present invention, those having a blocked isocyanate group in the urethane skeleton (for example, trade name “Elastoron”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) are particularly preferable. Such a blocked isocyanate not only reacts with urethane acrylate, which is an ionizing radiation curable resin, but also self-crosslinks with the urethane bond of the blocked isocyanate itself to form an allophanate bond, thereby forming a second cured product of the blocked isocyanate. Therefore, also in the formation of the second cured product, the reaction time is slower than the reaction between the isocyanate and the hydroxyl group, and this is a mode suitable for heating and bending the resin substrate.

  Other specific examples of the isocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI) and trimethylhexamethylene diisocyanate (TMDI); alicyclic diisocyanates such as isophorone diisocyanate (IPDI); xylylene diisocyanate (XDI) Aromatic diisocyanates such as tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI); dimer acid diisocyanate (DDI), hydrogenated TDI (HTDI), hydrogenation Hydrogenated diisocyanates such as XDI (H6XDI) and hydrogenated MDI (H12MDI); dimers, trimers, and higher molecular weight polyisocyanates of these diisocyanate compounds Sulfonates; trimethylolpropane polyhydric alcohols or water, or adduct of a low molecular weight polyester resin.

  Specific examples of the blocking agent include oximes such as methyl ethyl ketoxime, acetoxime, cyclohexanone oxime, acetophenone oxime, and benzophenone oxime; phenols such as m-cresol and xylenol; methanol, ethanol, butanol, 2-ethylhexanol, cyclohexanol, Examples include alcohols such as ethylene glycol monoethyl ether; lactams such as ε-caprolactam; diketones such as diethyl malonate and acetoacetate; mercaptans such as thiophenol. Other examples include ureas such as thiourea; imidazoles; carbamic acids and the like.

  The blocked isocyanate can be obtained by reacting the above isocyanate compound and the blocking agent by a conventional method until free isocyanate groups disappear. Moreover, as a block isocyanate, a commercial item can also be used.

  The blending amount of the blocked isocyanate in the hard coat layer 12 is not particularly limited, but from the viewpoint of easily improving the scratch resistance and processing characteristics of the transfer hard coat film and hard coat laminate of the present invention, the urethane acrylate in the hard coat layer. Preferably it is 1.0 mass part or more with respect to 100 mass parts, More preferably, it may be 3.0 mass parts or more. If the content of blocked isocyanate in the hard coat layer is excessive, the recoatability such as difficulty in forming the primer layer 13 on the hard coat layer 12 may be deteriorated. May be less than 7.0 parts by weight, more preferably 5.0 parts by weight or less, with respect to 100 parts by weight of urethane acrylate in the hard coat layer.

  The hard coat layer 12 may contain a curing catalyst for accelerating the dissociation reaction of the blocked isocyanate in addition to the above-mentioned blocked isocyanate. When the hard coat layer contains such a catalyst, when a hard coat laminate is formed using the transfer hard coat film of the present invention, a curing reaction due to crosslinking is performed at a very wide range of heating temperatures and heating times. It can be fully advanced. One curing catalyst may be used alone, or two or more curing catalysts may be used in combination.

  Specific examples of the curing catalyst include organotin compounds such as dibutyltin dilaurate, dibutyltin dioctate, and dibutyltin diacetate; aluminum tris (acetylacetonate), titanium tetrakis (acetylacetonate), titanium bis (acetylacetonate), titanium Bis (butoxy) bis (acetylacetonate), titanium bis (isopropoxy) bis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate), zirconium bis (isopropoxy) bis (acetylacetonate), etc. And metal chelate compounds. Among these, tin-based catalysts are generally used.

  The blending amount of the curing catalyst in the hard coat layer 12 is not particularly limited, but from the viewpoint of easily improving scratch resistance and processing characteristics of the transfer hard coat film and hard coat laminate of the present invention, the urethane acrylate in the hard coat layer. Preferably it may be 0.01 mass part or more with respect to 100 mass parts, More preferably, it may be 0.02 mass part or more. If the catalyst content in the hard coat layer is too high, the processing characteristics of the transfer hard coat film or hard coat laminate may be lowered. The amount may be preferably 1.00 parts by mass or less, more preferably 0.08 parts by mass or less, relative to 100 parts by mass of urethane acrylate.

(Other ingredients)
Moreover, the curable resin composition forming the hard coat layer 12 may contain scratch-resistant particles in order to further improve the scratch resistance. Scratch-resistant particles include inorganic and organic particles. Examples of inorganic particles include inorganic particles such as alumina, silica, kaolinite, iron oxide, diamond, and silicon carbide. On the other hand, the organic particles are preferably synthetic resin beads such as a crosslinked acrylic resin and a polycarbonate resin. Examples of the particle shape include a sphere, an ellipsoid, a polyhedron, a scale shape, and the like, and are not particularly limited. However, a spherical shape is preferable in that the hardness becomes higher and excellent scratch resistance can be obtained.

  The particle diameter of the scratch-resistant particles is not particularly limited, but is preferably 0.1 μm or more and 4 μm or less, and more preferably 0.5 μm or more and 3 μm or less from the viewpoint of the hardness and smoothness of the hard coat layer 12. The average particle diameter of the particles is a volume average particle diameter. The volume average particle size can be measured by laser diffraction type or laser scattering type particle size distribution measurement.

  Further, the curable resin composition used for forming the hard coat layer 12 may contain a weather resistance improving agent in order to obtain excellent weather resistance. Examples of the weather resistance improver include an ultraviolet absorber and a light stabilizer, and the ultraviolet absorber absorbs harmful ultraviolet rays and improves long-term weather resistance and stability. Further, the light stabilizer itself hardly absorbs ultraviolet rays, but stabilization can be obtained by efficiently capturing harmful free radicals generated by the ultraviolet rays.

  Preferred examples of the ultraviolet absorber include inorganic ones such as titanium dioxide, cerium oxide, and zinc oxide, and benzotriazole-based and triazine-based organic ultraviolet absorbers. Among these, triazine-based ultraviolet absorbers are preferable. Moreover, as a light stabilizer, a hindered amine light stabilizer (HALS) is mentioned preferably, for example.

  Of the triazine-based UV absorbers, hydroxyphenyltriazine-based UV absorbers are more preferable. Examples of the hydroxyphenyltriazine-based ultraviolet absorber include 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5- Triazine, 2- [4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tri Decyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy- -(2'-ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine and the like are preferred, and these are used alone. Alternatively, a plurality of types can be used in combination.

  The hindered amine light stabilizer is preferably a hindered amine light stabilizer having a reactive functional group. The reactive functional group is not particularly limited as long as it has reactivity with an ionizing radiation curable resin. For example, a functional group having an ethylenic double bond such as a (meth) acryloyl group, a vinyl group, or an allyl group. Etc. are preferable, and at least one selected from these is preferable. Of these, a (meth) acryloyl group is preferable.

  Examples of the hindered amine light stabilizer having such a reactive functional group include 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate and bis (1,2,2,6,6-pentamethyl- 4-piperidyl) sebacate, bis (2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2, 2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis [N-butyl-N- (1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino] Preferred is -6- (2-hydroxyethylamine) -1,3,5-triazine.

  Various additives can be blended in the hard coat layer as long as the performance is not impaired. Examples of various additives include curing agents, curing aids (such as organic tin), polymerization inhibitors, crosslinking agents, antistatic agents, adhesion improvers, antioxidants, leveling agents, thixotropic agents, and couplings. Agents, plasticizers, antifoaming agents, fillers, solvents and the like.

  The thickness of the hard coat layer 12 is not particularly limited, but is preferably about 1 μm or more and 20 μm or less. From the viewpoint of obtaining excellent weather resistance, its durability, and transparency, it is more preferably 2 μm or more and 20 μm or less, further preferably 2 μm or more and 10 μm or less, and most preferably 2 μm or more and 6 μm or less. Moreover, since the generation | occurrence | production of hardening shrinkage can be reduced by making the thickness of the hard-coat layer 12 thinner, and manufacturing stability and manufacturing efficiency can be improved, it shall be 2 micrometers or more and 4 micrometers or less especially. Is preferred.

[Primer layer]
The primer layer 13 is composed of a resin composition for forming a primer layer containing a binder resin and an antiblocking agent, and functions as a stress relaxation layer for the hard coat layer 12 and improves the adhesion of the hard coat layer 12. Is a layer.

  The binder resin constituting the primer layer 13 preferably contains a two-component curable resin composed of a main agent and a curing agent.

  The main component of the binder resin constituting the primer layer 13 is not particularly limited. For example, polyurethane resin, (meth) acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin, petital resin, chlorinated polypropylene, chlorinated polyethylene Etc. These binder resins may be used individually by 1 type, or may be used in combination of 2 or more type. Among these binder resins, a polyurethane resin is preferable from the viewpoint of adhesion and weather resistance.

  The polyurethane resin is more preferably a polyurethane resin having an acrylic skeleton in the polymer chain of the polyurethane resin from the viewpoint of weather resistance and durability. Examples of the polyurethane resin having an acrylic skeleton in the polymer chain include, for example, a urethane acrylic copolymer which is a copolymer of a urethane component and an acrylic component, a hydroxyl group or an isocyanate group as a polyol component or a polyisocyanate component constituting the polyurethane. Among them, urethane acrylic copolymers are preferable. Urethane acrylic copolymers are, for example, a method in which a polyol compound and an isocyanate compound are reacted with an acrylic resin having at least two hydroxyl groups in one molecule (see JP-A-6-1000065, etc.), It can be obtained by a method in which an acrylic monomer is reacted with a urethane prepolymer having bonds at both ends (see JP-A-10-1524).

  Among the polyurethane resins having an acrylic skeleton in the polymer chain, those having a polycarbonate skeleton or a polyester skeleton in the polymer chain are preferable from the viewpoint of adhesion to the hard coat layer 12. Polyurethane having an acrylic skeleton in the polymer chain, and further having a polycarbonate skeleton or a polyester skeleton, a polycarbonate urethane acrylic copolymer or a polyester urethane component, which is a copolymer of a polycarbonate urethane component and an acrylic component. A polyester urethane acrylic copolymer, which is a copolymer of an acrylic component, is more preferred, and a polycarbonate urethane acrylic copolymer is particularly preferred from the viewpoint of providing even better weather resistance. These polyurethanes may be used individually by 1 type, and may be used in combination of 2 or more type.

  The polycarbonate-based urethane acrylic copolymer can be obtained, for example, by copolymerizing a polycarbonate-based urethane obtained by reacting carbonate diol and diisocyanate with a diol having an acrylic skeleton. The polycarbonate urethane acrylic copolymer can also be obtained by reacting a diol having an acrylic skeleton with a carbonate diol and a diisocyanate. Here, as the diol having the acrylic skeleton, specifically, (meth) acrylic acid, (meth) acrylic acid alkyl ester having about 1 to 6 carbon atoms in the alkyl group, or an oligomer obtained by radical polymerization thereof, or Examples of the prepolymer (with a degree of polymerization of about 2 or more and about 10 or less) include compounds in which two hydroxyl groups are introduced.

Specific examples of the diisocyanate include aliphatic isocyanates such as hexamethylene diisocyanate; and alicyclic isocyanates such as isophorone diisocyanate and hydrogen-converted xylylene diisocyanate. Further, as the carbonate diol, specifically, a compound represented by the following general formula (1) (wherein R ¹ is the same or different and may have a substituent having 1 to 12 carbon atoms). The following alkylene groups, divalent heterocyclic groups having 1 to 12 carbon atoms that may have a substituent, or divalent fats having 1 to 12 carbon atoms that may have a substituent A cyclic group, and m ₁ is an integer of 1 or more and 10 or less.
HO— [R ¹ —O— (C═O) —O] m ₁ —R ¹ —OH (1)

  The polycarbonate-based urethane acrylic copolymer can also be obtained by radical polymerization of a polycarbonate-based polyurethane prepolymer into which a radical polymerizing group is introduced with an acrylic monomer. Specific examples of the acrylic monomer include (meth) acrylic acid and alkyl (meth) acrylic esters having an alkyl group with 1 to 6 carbon atoms.

The polyester urethane acrylic copolymer can be obtained, for example, by copolymerizing a polyester urethane obtained by reacting an ester diol and a diisocyanate with a diol having an acrylic skeleton. Alternatively, it can also be obtained by reacting an ester diol and a diisocyanate with a diol having an acrylic skeleton. Here, the diol and diisocyanate having an acrylic skeleton are the same as those used in the production of the polycarbonate urethane acrylic copolymer. Further, as the ester diol, specifically, a compound represented by the following general formula (2) (wherein R ² is the same or different and may have a substituent having 1 to 12 carbon atoms) An alkylene group, a divalent heterocyclic group having 1 to 12 carbon atoms that may have a substituent, or a divalent alicyclic group having 1 to 12 carbon atoms that may have a substituent. And m ₂ is an integer of 1 or more and 10 or less.
_{^{HO- [R 2 -O- (C =}} O)] m 2 -R 2 -OH (2)

  The polyester-based urethane acrylic copolymer can also be obtained by radical polymerization of a polyester-based polyurethane prepolymer into which a radical polymerizing group is introduced with an acrylic monomer. The acrylic monomer is the same as that used for the production of the polycarbonate urethane acrylic copolymer.

  The polyurethane used for the primer layer preferably has an acrylic component content of 1 to 30% by mass in order to provide excellent weather resistance. Here, the content of the acrylic component in the polyurethane is a ratio (mass%) occupied by monomers constituting the acrylic skeleton per the total mass of the polyurethane. From the viewpoint of providing even better weather resistance, the content of the acrylic component in the polyurethane is preferably 5% by mass or more and 20% by mass or less. The acrylic component content in the polyurethane is calculated by measuring the NMR spectrum of the polyurethane and determining the ratio of the peak area attributed to the acrylic component to the total peak area.

  In the primer layer, when the polyurethane and other binder resin are used in combination, the mixing ratio thereof is not particularly limited. For example, the polyurethane is 50 parts by mass or more per 100 parts by mass of the binder resin. What is necessary is just to set so that it may become 70 mass parts or more preferably, More preferably, it may be 85 mass parts or more.

  From the viewpoint of promoting the curing of the main agent, a curing agent may be added to the primer layer. Examples of such a curing agent include isocyanate curing agents such as tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate, and naphthalene-1,5-diisocyanate. The amount of the curing agent used is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 10 parts by mass or more and 30 parts by mass or less, and more preferably 20 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin as the main agent. Further preferred.

  Various additives other than the above can be blended with the primer layer 13 as necessary, as long as the effects of the present invention are not impaired. Examples of such additives include weather resistance improvers such as ultraviolet absorbers and light stabilizers, wear resistance improvers, infrared absorbers, light stabilizers, antistatic agents, adhesion improvers, leveling agents, Examples include a thixotropic agent, a coupling agent, a plasticizer, an antifoaming agent, a filler, a solvent, and a colorant. These additives can be appropriately selected from those commonly used.

  The thickness of the primer layer 13 relating to the present embodiment is not particularly limited, and examples thereof include 0.1 μm to 10 μm, preferably 0.1 μm to 5 μm, and more preferably 1 μm to 4 μm.

[Heat seal layer]
The heat seal layer 14 is an adhesive resin-containing layer provided for laminating the hard coat layer 12 on the resin substrate 20. That is, the hard coat layer 12 is laminated on the resin base 20 via the heat seal layer 14. In the case where the primer layer 13 includes particles, if the particles protrude from the surface of the primer layer 13 (so-called cueing occurs), the heat seal layer 14 improves the flatness of the sheet surface. Thus, the function of suppressing deterioration in transparency and ensuring excellent optical performance is exhibited.

  The adhesive resin used for the heat seal layer 14 is determined according to the material of the resin substrate 20, the transfer temperature and pressure during transfer, the use of the transfer product, and the like, and is not particularly limited. Generally, adhesive resin is heat fusion resin such as acrylic resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, polyester resin, chlorinated polypropylene, chlorinated rubber, urethane resin, epoxy resin, styrene resin, etc. Is preferred. The said resin may be used independently and may combine 2 or more types. From the standpoint that the refractive index difference with the particles contained in the primer layer 13 is small and the transparency and weather resistance of the sheet are easy to improve, it is particularly preferable to use an acrylic resin alone as the adhesive resin.

  The heat seal layer 14 is preferably thicker than the primer layer 13. From the viewpoint of securing the function of adhering the transfer layer 15 including the hard coat layer 12 to the resin substrate 20 and excellent transparency, the thickness of the heat seal layer 14 is preferably 1 μm or more and 7 μm or less. More preferably, it is 1 μm or more and 6 μm or less.

  Further, the transfer hard coat film 10 can be protected on its surface by attaching a cover film (protective film) made of a resin such as polyethylene resin on the heat seal layer 14. When a cover film is provided on the transfer hard coat film 10, the cover film is peeled off, the heat seal layer 14 is exposed, and transferred to the resin substrate 20 through the surface of the heat seal layer 14.

<Hard coat laminate>
The configuration of the hard coat laminate 1 of the present invention will be described below with reference to FIG. The hard coat laminate 1 of the present invention is obtained by transferring the transfer layer 15 to the resin substrate 20 through the heat seal layer 14 using the transfer hard coat film 10 described above. Specifically, as shown in FIG. 2A, the hard coat laminate 1 of the present invention has at least a heat seal layer 14, a primer layer 13, a hard coat layer 12, and a base film on a resin substrate 20. 11 are arranged in this order. Arrangement | positioning of the base film 11 is arbitrary, and as shown in FIG.2 (b), the base film 11 may peel from the transfer layer 15 in the arbitrary steps in a use process.

  Note that “lamination on a resin substrate” is not only a mode in which the transfer hard coat film 10 is directly laminated on the resin substrate 20 via the heat seal layer 14 but also indirectly via a printing layer or the like. The embodiment to be included is also included. In the case of the latter aspect, a printing layer etc. are laminated | stacked on the resin substrate 20 surface part or the whole surface, and also the transfer hard coat film 10 is laminated | stacked. Further, the hard coat layer 12 may be laminated on one surface of the resin substrate 20 or may be laminated on both surfaces of the resin substrate 20. When the hard coat layer 12 is laminated on both surfaces of the resin substrate 20, it is easy to further improve the scratch resistance and processing characteristics of the obtained hard coat laminate 1.

[Resin substrate]
What is necessary is just to select suitably for the resin base | substrate 20 according to a desired resin molding. Examples of the resin constituting the resin substrate 20 include acrylic resins such as polycarbonate resin and ABS resin. The thickness of the resin substrate 20 is usually preferably 1 mm or more and 20 mm or less, and more preferably 2 mm or more and 10 mm or less. If the resin base 20 is too thin, practical strength such as surface rigidity becomes insufficient, and if the resin base 20 is too thick, the processability of the resin base 20 is affected. The shape of the resin substrate 20 may be appropriately selected according to the intended use of the resin molded body, and is not limited to a plate shape.

  The hard coat laminate 1 of the present invention includes a hardened layer 12 containing a predetermined amount of a first cured product of urethane acrylate and a second cured product of blocked isocyanate, and the first cured product and the second cured product. Is bonded via an allophanate bond, and thus has excellent scratch resistance and processing characteristics. The scratch resistance can be evaluated by the method shown in the examples. The processing characteristics can be evaluated depending on, for example, whether the processing characteristics can be suitably used for heat bending.

<Method for producing hard coat laminate>
The hard coat laminate 1 of the present invention can be produced by a known method for producing an ionizing radiation curable hard coat except that the hard coat layer 12 is provided. Below, the example of a manufacturing method is shown.

  First, the hard coat layer 12, the primer layer 13, and the heat seal layer 14 are laminated in this order on the base film 11 to form the transfer layer 15. In the hard coat layer 12, the hard coat layer 12 includes A urethane acrylate having a mass ratio in the resin of more than 50% and a blocked isocyanate are contained (laminated body forming step). For example, the hard coat layer 12 can be formed by applying to the surface of the base film 11 a composition (a curable resin composition for forming a hard coat layer) containing a component constituting the hard coat layer 12. The primer layer 13 can be formed by performing a corona discharge treatment on the surface of the hard coat layer 12 and applying a composition containing a component constituting the primer layer 13 (primer layer forming resin composition). The heat seal layer 14 can be formed by applying a composition (resin composition for forming a heat seal layer) containing a component constituting the heat seal layer 14 on the primer layer 13.

  During or after the laminate forming process, the hard coat layer 12 is cured with ionizing radiation to form a first cured product of urethane acrylate (ionizing radiation curing process). From the viewpoint of uniformly curing the hard coat layer 12, usually, after the hard coat layer 12 is formed on the base film 11, the hard coat layer 12 is cured by irradiation with ionizing radiation, and then the primer layer 13 is used. It is preferable to form.

  Next, the transfer layer 15 after the ionizing radiation curing step is transferred onto the resin substrate 20 through the heat seal layer 14 to obtain a resin substrate with a hard coat layer (transfer step). As the transfer, known roll transfer, in-mold molding, press transfer, or the like can be adopted.

  After the transfer process, the second cured product of block isocyanate and the first curing are performed by bending the resin substrate 20 with a hard coat layer while heating or by heating the resin substrate 20 with a hard coat layer after bending. An allophanate bond is formed through the product and the second cured product (heat bending step). Although heating temperature is not specifically limited, 100 degreeC or more and 180 degrees C or less may be sufficient. The heating time is preferably 60 seconds or more and 1000 seconds or less.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited to the following Examples at all.

[Preparation of transfer hard coat film]
The curable resin composition for forming a hard coat layer was applied to one surface of the base film to form an uncured resin layer. The uncured resin layer was irradiated with an electron beam under conditions of 90 kV and 7 Mrad (70 kGy) to crosslink and cure the uncured resin layer, thereby forming a hard coat layer (layer thickness: 1.5 μm). (This process corresponds to an ionizing radiation curing process). The surface of the hard coat layer opposite to the base film is subjected to corona discharge treatment, and a primer layer forming resin composition is applied to form a primer layer (layer thickness: 2 μm). The resin composition for forming a heat seal layer was applied to form a heat seal layer (layer thickness: 1.5 μm) (this step corresponds to a laminate forming step).

  By the above operation, a transfer hard coat film in which a base film, a hard coat layer, a primer layer, and a heat seal layer were laminated in this order was obtained. Details of the materials used are as follows.

(Base film)
Product name “Toyobo Ester Film E5101,” manufactured by Toyobo Co., Ltd. (film made of polyethylene terephthalate resin (PET) having a thickness of 50 μm)

(Curable resin composition for forming hard coat layer)
Urethane acrylate (trade name “EBLF-2Y”, manufactured by Showa Ink Industries, Ltd.): 100 parts by mass Curing agent (hexamethylene diisocyanate block isocyanate, manufactured by Showa Ink Industries, Ltd.): Table for 100 parts by mass of urethane acrylate The amount shown in 1 (unit: part by mass) was added.
In Example 4 alone, 0.06 parts by mass of a curing catalyst (organic tin, Showa Ink Industries, Ltd.) was blended with 100 parts by mass of urethane acrylate.

(Primer layer forming resin composition)
Acrylic urethane resin (trade name “SG-63”, manufactured by DIC Graphics Corporation): 100 parts by mass Curing agent (hexane methylene diisocyanate, manufactured by Dainichi Seika Kogyo Co., Ltd.): 6 parts by mass

(Resin composition for forming heat seal layer)
Acrylic resin (trade name “TM-R600 (NT) K3”, manufactured by Dainichi Seika Kogyo Co., Ltd.)

[Preparation of heat-bent hard coat laminate]
A resin substrate made of a polycarbonate plate having a thickness of 2 mm (trade name “Iupilon Sheet”, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was heated using a hot plate at 150 ° C. The transfer hard coat film is placed on one side of the heated resin substrate so that the heat seal layer and the resin substrate are in contact with each other, and after heating and laminating three times with a 190 ° C. hot ram roll, 25 kgf / cm ^{2 is applied.} Was heated and bent at a pressure of 15 minutes. The base film was peeled off to produce a hard coat laminate in which the resin substrate and the transfer layer were integrated.

  By the above operation, a heat-bent hard coat laminate in which a resin substrate (polycarbonate plate), a heat seal layer, a primer layer, a hard coat layer, and a base film were laminated in this order was obtained.

[Evaluation of physical properties of hard coat film for transfer and hard-coated laminate processed by heat bending]
The physical properties (elongation rate, scratch resistance and recoatability) of each hard coat film and each hard coat laminate obtained above were evaluated by the following methods. The results are shown in Table 1. In Table 1, the term “before heat treatment” indicates the evaluation result before heating of the transfer hard coat film, and the term “after heat treatment” indicates the evaluation result after heating of the transfer hard coat film. .

(Measurement method of elongation)
Before and after each hard coat film was heated at 150 ° C. for 15 minutes, those dumbbell-shaped according to JIS K6732 were used as test sheets. Using a tensile and compression tester, the test sheet was pulled under conditions of a tensile speed of 100 mm / min and an interval between chucks of 100 mm under a temperature environment of 150 ° C., and when the hard coat layer was cracked visually. The elongation was measured. The elongation percentage was calculated by the formula: (sample length after test−sample length before test) ÷ sample length before test × 100. As a tensile and compression tester, a trade name “Tensilon RTC-1250A” (manufactured by Orientec Co., Ltd.) was used. The lower the elongation value, the harder the hard coat layer and the harder the resin is.

(Scratch resistance)
Before and after heating the surface of the hard coat layer of each hard coat laminate at 150 ° C. for 15 minutes, 1000 reciprocating friction was applied using steel wool (# 0000) with a load of 1 kg / cm ³ . The haze difference (ΔH) on the surface of the hard coat layer before and after friction was measured with a haze meter (trade name “Haze Guard Plus”, manufactured by Toyo Seiki Seisakusho Co., Ltd.). It shows that the scratch resistance of a hard-coat layer is so high that the value of (DELTA) H is low.

  As shown in the section of “Elongation” in Table 1, the hard coat film of the present invention in which urethane acrylate is highly blended in the hard coat layer and the blocked isocyanate is blended (Examples 1 to 4), Elongation is high and the crosslink density of the resin is low. Furthermore, it can be understood that the hard coat laminate obtained by subjecting the transfer hard coat film to heat bending processing has a low elongation and the resin curing in the hard coat layer is sufficiently advanced. The hard coat laminate obtained from the transfer hard coat film of the present invention had sufficient scratch resistance while having the same hardness as the comparative example.

  On the other hand, the transfer hard coat film of the comparative example in which the blocked isocyanate is not blended in the hard coat layer has a low elongation and the resin curing in the hard coat layer is sufficiently advanced. It was not possible to produce a hard coat laminate.

DESCRIPTION OF SYMBOLS 1 Hard coat laminated body 10 Transfer hard coat film 11 Base material film 12 Hard coat layer 13 Primer layer 14 Heat seal layer 15 Transfer layer 20 Resin substrate

Claims (5)

On the base film, at least a hard coat layer, a primer layer, and a heat seal layer are arranged in this order,
The said hard-coat layer is a hard-coat film for transcription | transfer containing the 1st hardened | cured material of urethane acrylate exceeding 50% by mass ratio in resin in this hard-coat layer, and block isocyanate.   The hard coat film for transfer according to claim 1, wherein the blocked isocyanate has a blocked isocyanate group in a urethane skeleton.   The hard coat film for transfer according to claim 1, wherein the hard coat layer further contains a curing catalyst. On the resin substrate, at least a heat seal layer, a primer layer, and a hard coat layer are arranged in this order,
The hard coat layer includes a first cured product of urethane acrylate having a mass ratio in the resin of more than 50% and a second cured product of blocked isocyanate, and the first cured product, the second cured product, Is a hard coat laminate bonded through allophanate bonds. On the resin substrate, at least a heat seal layer, a primer layer, and a hard coat layer are arranged in this order, a method for producing a hard coat laminate,
At least a hard coat layer, a primer layer, and a heat seal layer are laminated in this order. In the hard coat layer, urethane acrylate having a mass ratio in the resin in the hard coat layer of more than 50%, and blocked isocyanate And a laminate forming step containing:
An ionizing radiation curing step in which the hard coat layer is cured by ionizing radiation to form a first cured product of the urethane acrylate during or after the laminate forming step,
On the resin substrate, a transfer layer after the ionizing radiation curing step is transferred through the heat seal layer to obtain a resin substrate with a hard coat layer, and
After the transfer step, by bending the resin substrate with hard coat layer while heating, or by heating after bending the resin substrate with hard coat layer, the second cured product of the blocked isocyanate, and A heat bending step of forming an allophanate bond via the first cured product and the second cured product;
A method for producing a hard coat laminate comprising:

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