JP7275533B2 - Method for manufacturing resin molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin molding obtained by forming a cured film of the photocurable composition on a support using a photocurable composition and a wet coating method, and a method for producing the same.

Resin moldings made mainly of so-called photocurable resins, which are cured through a cross-linking reaction by irradiation with active energy rays such as ultraviolet rays and electron beams, are used for plastic films and transparent substrates for optical display devices. Widely used for various purposes.

A resin molding used as a film member or a transparent substrate is obtained by a curing reaction caused by ultraviolet irradiation of a photocurable resin. This curing reaction progresses very quickly, making it possible to produce a resin molding in a short period of time. Also, a photo-curing initiator is generally added to the photo-curing resin in order to induce the curing reaction.

However, the photo-curing initiator that remains after the curing reaction has been completed remains in the resin molding as it is, and causes deterioration in durability, particularly solvent resistance. A decrease in solvent resistance leads to deterioration in the quality of products using resin moldings, which poses a serious problem.

As a method for improving the durability of a photocurable composition against solvents, a method using a urethane (meth)acrylate resin having a specific structure is known. (For example, Prior Document 1)

However, in this method, the photocurable resin to be used is limited to only a specific structure, so the mechanical properties and physical properties of the resin molded product to be formed are limited by the structure of the photocurable resin, and depending on the application. cannot be used. Moreover, even by this method, the efficiency of the photocuring reaction of the photocurable resin is not improved, and there is a limit to the improvement in solvent resistance.

Japanese Patent No. 5955729

In view of the above problems, an object of the present invention is to enable the use of photocurable resins having a wider variety of structures in a resin molded article made of a photocurable composition, and to To provide a resin molded article which is less eluted into a solvent and has high solvent resistance.
Another object of the present invention is to provide a method for producing a resin molded body that further improves the efficiency of the photocuring reaction of a photocuring initiator.

In order to solve the above problems, the present invention
A resin composed of a photocurable composition containing at least two different urethane (meth)acrylates having a urethane skeleton and two or more (meth)acryloyl groups, which are urethane (meth)acrylates, and a photocuring initiator. A molded body,
When the thickness is 20 μm or more and 100 μm or less, and the composition ratio of the photocuring initiator in the solid component in the photocurable composition is A%, the gel fraction of the resin molding is (100-A- 1
)% or more.

Further, the present invention is a resin molding characterized in that the composition ratio of the photocuring initiator contained in the photocurable composition is 0.1% by weight or more and 5% by weight or less.

Further, the present invention is a resin molding characterized in that the photocurable composition contains a solvent.

Further, the present invention provides a method for manufacturing the resin molding,
a step of applying the photocurable composition to a support to form a coating film;
A step of irradiating the coating film with ultraviolet rays;
and a step of irradiating with infrared rays at least either before or after the ultraviolet ray irradiation.

Further, the present invention is a method for producing a resin molded article, further comprising a step of separating the resin molded article formed on the support from the support.

Further, the present invention is a method for producing a resin molding, characterized in that, after the step of applying the photocurable composition to the support to form a coating film, the step of drying the coating film is further included. be.

Further, the present invention is a method for producing a resin molding, wherein the support is a flexible substrate.

The present invention also provides a method for producing a resin molding, characterized in that the flexible substrate used as the support is conveyed by roll-to-roll.

According to the resin molding of the present invention, it is possible to obtain a resin molding having a structure that can be combined in various ways, and to obtain a resin molding having high solvent resistance with less initiator eluting from the resin molding into the solvent. becomes possible.
Further, according to the method for producing a resin molded article of the present invention, when a resin molded article having a thickness of several tens of μm is produced from a photocurable composition, the reaction of the initiator is achieved by using both infrared irradiation and ultraviolet irradiation. Since the curing reaction can proceed with an improved efficiency, almost no unreacted initiator remains and a resin molded article having high solvent resistance can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of the resin molding of this invention. FIG. 4 is a schematic diagram showing a step of peeling the resin molding of the present invention from a support. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the manufacturing apparatus of the resin molding which concerns on embodiment of this invention.

An example of a resin molded product and a method for producing the same according to the present invention will be described below with reference to the drawings, but the present invention is not limited to these, as long as it has the technical features of the present invention. , belong to the present invention.

As shown in the schematic cross-sectional view of FIG. 1, the resin molded body of one embodiment of the present invention is obtained as a resin molded body 10 by curing a coating film of a photocurable composition provided on a support 20. can get.

The resin molded body obtained in FIG. 1 can also be used as the resin molded body 10 as a single film by peeling from the support 20 as shown in FIG.

(Photocurable composition)
Next, the photocurable composition for producing the resin molding will be described.

As the photocurable composition used in the present invention, a resin that is cured through a cross-linking reaction by irradiation with an active energy ray such as an ultraviolet ray or an electron beam, that is, a photocurable resin can be used.

A urethane (meth)acrylate having a urethane skeleton and two or more (meth)acryloyl groups can be used as the photocurable resin used in the present invention.
Known ones can be used for this, but for example, after reacting a polyisocyanate such as diisocyanate with a polyol to form a urethane bond, it can be obtained by reacting a hydroxy ester of (meth)acrylic acid. urethane (meth)acrylates can be used.

In the present invention, "(meth)acryloyl group" means both "acryloyl group" and "methacryloyl group". Moreover, "(meth)acrylate" indicates both "acrylate" and "methacrylate".

Examples of polyols that can be used include polyester polyols, polycarbonate polyols, and polyether polyols.

Examples of polyisocyanates that can be used include hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate, tolylene diisocyanate (TDI), and the like.

The urethane (meth)acrylate obtained by these methods can be obtained as a monomer or a partially polymerized oligomer. The molecular weight is not limited as long as the photocurable composition can form a uniform coating film, but is preferably 1,000,000 or less, more preferably 500,000 or less.

Furthermore, commercially available urethane (meth)acrylates having two or more (meth)acryloyl groups can be used. For example, Shiko UV-3520 (Nippon Synthetic Chemical Industry), Shiko UV-7000 (Nippon Synthetic Chemical Industry), UF-8001G (Kyoeisha Chemical Co., Ltd.) and the like can be used.

Further, urethane (meth)acrylates having an aromatic ring or alicyclic structure have relatively high mechanical properties, and for example, UA-306I (Kyoeisha Chemical), AH-600 (Kyoeisha Chemical) and the like can be used.

In the present invention, two or more of these urethane (meth)acrylates can be used in combination. At that time, by combining materials having different mechanical properties, it is possible to obtain a resin molding having properties suitable for the intended use.

Further, in the present invention, a photocurable resin other than the above can be added. For example, by using a polyfunctional (meth)acrylate having an isocyanuric acid skeleton, it is possible to produce a resin molding with high mechanical strength. Meth)triacrylate, isocyanuric acid ethylene oxide-modified di- and tri-(meth)acrylates, ε-caprolactone-modified tris((meth)acryloxyethyl)isocyanurate and the like can be used.

Furthermore, as polyfunctional (meth) acrylates having an isocyanuric acid skeleton, M-215 (Toagosei), M-315 (Toagosei), A-9300 (Shin-Nakamura Chemical Industry), A-9300-1CL (Shin-Nakamura Chemical industry) and the like can be used.

(Photocuring initiator)
The photo-curing initiator contained in the photo-curable composition used in the present invention is not particularly limited as long as it cures the photo-curable resin and causes particularly little coloration. For example, photocuring initiators for surface curing include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl] -α-hydroxyketones such as 2-hydroxy-2-methyl-1-propan-1-one and α-hydroxyketones such as 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one Amino ketones can be used.

In addition, as a photocuring initiator for the internal curing system, acylphosphine oxide such as diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, 2-benzyl-2-dimethylamino-1-(4-morpholino phenyl)-butanone-1 and the like can be used.

In addition to those shown above, for example, photo-curing initiators having surface-curing or internal-curing characteristics such as acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, etc. If so, it can be selected and used as appropriate.

Moreover, these photocuring initiators can be used alone or in combination of two or more.

Moreover, the amount of the photocuring initiator to be added is preferably 0.1% by weight or more and 5% by weight or less relative to the solid components in the photocurable composition.
If the amount is less than this range, the degree of curing of the resulting resin molding will be low. In particular, if the amount is too high, there is a possibility that the quality of the resin molded body will be deteriorated due to the coloring of the resin molded body, the residue of the photocuring agent, the decomposition product, and the like.

If the photocuring initiator in the resin molding is used effectively, it will be incorporated into the polymer structure formed by the curing reaction between the resins, so it will not be eluted by the solvent. Therefore, the more efficiently the photo-curing initiator contained in the photo-curing composition is used, the more the photo-curing initiator is inhibited from eluting into the solvent and the more insoluble it becomes in the solvent. Therefore, in this case, the gel fraction of the resin molding is increased.

On the other hand, even if the photo-curing initiator is used efficiently and the ideal curing reaction is progressing, there is a decomposition product of the photo-curing initiator that is not incorporated into the polymer structure by being cleaved when it becomes reactive with UV irradiation. It always occurs, and it dissolves into the solvent.

Furthermore, even if the curing reaction progresses and a polymer structure is formed in the resin molding, the resin component with a low degree of polymerization still dissolves into the solvent. In the curing reaction in the coating film, it is difficult to make the degree of polymerization uniform, and it is inevitable that a certain amount of polymer structure with a low degree of polymerization is generated.

As a result of technical studies by the inventors, the following findings were obtained. That is, as the gel fraction of the resin molding obtained by ideally progressing the curing reaction from the photocurable composition, relative to the composition ratio A% of the photocurable initiator in the solid component in the photocurable composition , (100-A-1)% or more is appropriate. If the gel fraction is at least this value, the solvent insolubility of the obtained resin molding is sufficiently high, and high durability can be obtained.

(solvent)
The solvent contained in the photocurable composition used in the present invention is not particularly limited as long as it dissolves the photocurable resin and the photocuring initiator. Ethers such as, for example, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole and phenetole, also acetone , methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methyl cyclohexanone, and methyl cyclohexanone, as well as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, propionic acid Esters such as methyl, ethyl propionate, n-pentyl acetate, and γ-butyrolactone, as well as cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve, and cellosolve acetate, and dimethyl carbonate can be used. These solvents can be used alone or in combination of two or more.

The blending ratio of the solvent may be appropriately adjusted so that the viscosity range is suitable for the coating method described below, provided that the solid content in the photocurable composition such as the photocuring initiator can be uniformly dissolved. It is preferably 1% by mass or more and 50% by mass or less with respect to the total amount of the composition. If the blending ratio of the solvent is less than 1% by mass, the coating film thickness may become uneven without effective viscosity reduction due to the solvent. Since the solvent cannot be removed, the residual solvent in the resin molding may affect the properties.

Further, in order to improve the surface properties of the coating film formed by the photocurable composition, a solvent having a relatively high boiling point is preferable because it improves leveling properties (uniform coating properties). On the other hand, if the coating film is thick, the solvent tends to remain in the film, so the boiling point of the solvent should be as low as possible. good.

In addition, the photocurable composition used in the present invention contains polymeric plasticizers, antifouling agents, surface modifiers, leveling agents, refractive index modifiers, curing agents, photosensitizers, conductive materials, etc. as additives. can be used. It may be appropriately selected according to the application of the resin molded body to be produced.

(support)
Next, the step of applying the photocurable composition used in the present invention to a support will be described.

The photocurable composition containing the above components can be coated on a support and irradiated with ultraviolet rays including infrared irradiation at least either before or after ultraviolet irradiation to form a cured film that will be a resin molding. can.

The support used in the present invention does not dissolve in each component contained in the photocurable composition, and after coating the photocurable composition, the support deforms in each step such as ultraviolet irradiation and infrared irradiation. If you don't have to, you can use common materials.

Among them, those having smoothness, heat resistance, and excellent mechanical strength are preferable. For example, film-like flexible substrates made of various resins such as polyethylene terephthalate, polyethylene naphthalate, polymethyl acrylate, polymethyl methacrylate, polyacrylate, polymethacrylate, polycarbonate, polyamide, polypropylene, polyvinyl acetal, and polyether ketone, Or a roll-shaped metal body etc. can be mentioned.

When a flexible base material is used as a support and conveyed by roll-to-roll to produce a resin molding, the thickness of the flexible base material should be such that it can be continuously conveyed by a base material conveying device. The thickness is preferably about 25 μm or more and 200 μm or less, more preferably 40 μm or more and 100 μm or less. If it is thinner than 25 μm, it may break due to the tension applied to the flexible substrate, and if it is thicker than 200 μm, it may become a factor of attenuating heat and light in the process of forming a cured film. However, the thickness of the flexible substrate is not limited to the above range.

(Application method)
The method for applying the photocurable composition onto the support is not particularly limited as long as a resin molding having a thickness of 20 to 100 μm can be produced with a uniform film thickness. A method generically called a wet coating method can be used. For example, dip coating method, spin coating method, flow coating method, spray coating method, roll coating method, gravure roll coating method, air doctor coating method, blade coating method, wire doctor coating method, knife coating method, reverse coating method, transfer coating method, A roll coating method, a microgravure coating method, a kiss coating method, a cast coating method, a slot orifice coating method, a calendar coating method, a die coating method, a cap coating method, an applicator coating method, a bar coating method and the like can be used. Among them, coating methods such as the die coating method, the cap coating method, and the roll coating method can form a uniform coating film with a photocurable composition having a wide range of viscosities.

When the photocurable composition contains a solvent, a drying step may be included to remove the solvent from the coating film. In that case, a known drying means can be appropriately used in the drying step. For example, heating, air blowing, hot air, etc. can be used.

(Ultraviolet irradiation and infrared irradiation)
In the method for producing a resin molded product of the present invention, when the photocurable resin is cured, the progress of the polymerization reaction of the photocurable resin can be enhanced by applying infrared irradiation before or after the ultraviolet irradiation. This method will be described below.

As a method for obtaining a resin molding by curing the coating film formed on the support, a well-known ultraviolet irradiation method can be used as appropriate. For example, light sources such as low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, xenon lamps, and electrodeless discharge tubes can be used. As irradiation conditions, the amount of ultraviolet irradiation can be set to 100 to 2000 mJ/cm ² . If the amount of irradiation is less than this, the resin may not be sufficiently cured and the strength may be insufficient, and if the amount of irradiation is more than this, there is a possibility that discoloration may occur due to decomposition of the initiator or the like.

Moreover, as a method of irradiating with infrared rays at least either before or after ultraviolet irradiation, a known ultraviolet irradiation method can be appropriately used. For example, heaters having a maximum energy wavelength of 1.2 to 2.7 μm, such as short-wave infrared heaters, medium-wave infrared heaters, and carbon heaters, can be used.

The amount of infrared irradiation can be set to 60 to 150 kW/m ² , and is not limited as long as it does not cause damage such as roughness or waviness due to excessive heating of the coating film or support.

The infrared irradiation unit can be installed side by side with the ultraviolet light source unit in the ultraviolet exposure device. Infrared irradiation can be performed collectively with the ultraviolet irradiation step by installing the unit before and after the ultraviolet light source unit.

In this case, by preparing a plurality of infrared irradiation units, it is possible to install them behind the ultraviolet irradiation units. Accordingly, by irradiating with infrared rays before and after the irradiation with ultraviolet rays, the progress of the polymerization reaction of the resin molding can be further enhanced.

Both the ultraviolet irradiation and infrared irradiation steps can be performed in an air atmosphere.

The coating film thickness after curing is preferably in the range of 20 μm or more and 100 μm or less from the viewpoint of coating accuracy and handling. If the thickness is less than 20 μm, it is difficult to handle due to low mechanical strength. On the other hand, when the thickness is more than 100 μm, winding and uniform application of the photocurable composition become difficult.

(Peeling process)
Further, the resin molded article formed on the support can be obtained as a single film resin molded article by peeling from the support.

Therefore, a step of peeling off the formed resin molding from the support may be included. A known method can be appropriately used for peeling from the support. For example, in the case of roll-to-roll transport, the support can be wound into a roll, and the resulting resin molding can also be wound into a roll and recovered. In that case, if the peeling from the support causes electrification, it can be prevented by installing a static elimination equipment such as an ionizer in the peeling portion.

Further, a support from which the formed resin molded article can be peeled off can be used. Releasability can be imparted. As a method for imparting releasability, a release agent such as silicone oil or silicone varnish may be applied to the surface of the support, or a thin film layer of silicone rubber may be formed.
For the same purpose, fluororesin and fluororubber may also be used, and fluororesin fine powder may be mixed with silicone rubber or ordinary rubber to provide releasability. Any method may be used as long as the photocurable composition can be uniformly applied to the support and a cured film can be formed.

Further, when a flexible base material is used as the support, a general-purpose release film having a release layer formed in advance on the surface layer can be used in order to improve the release property of the resin molding.

(Manufacturing equipment)
FIG. 3 shows an example of an apparatus for producing a resin molding of the present invention in which a support is conveyed by roll-to-roll. When the support is a flexible substrate, it becomes possible to use a roll-to-roll transport system.
As shown in FIG. 3, this manufacturing apparatus applies a photocurable composition to form a resin molding on a support 20 transported by rotating a support unwinding section 31 in the direction of the arrow. In addition to the application section 41 and the curing unit 50 for the resin molding, a drying section 42 can be provided as necessary.

An ultraviolet irradiation section 51 and an infrared irradiation section 52 can be provided as elements constituting the resin molding curing unit 50 . The infrared irradiation section 52 can be provided before and after the ultraviolet irradiation section, and either one of the infrared irradiation section 52a provided before the ultraviolet irradiation and the infrared irradiation section 52b provided after the ultraviolet irradiation may be provided. Alternatively, a curing unit 50 for a resin molding in which the arrangement of the infrared ray irradiation unit 52 is changed for each manufacturing condition may be used.

Moreover, the curing unit 50 may be an open system, as long as it irradiates ultraviolet rays and infrared rays in an atmospheric atmosphere.

Alternatively, the curing unit 50 can be a chamber-like closed system if an exhaust system is introduced.

The resin molding 10 formed by curing the coating film by the resin molding curing unit 50 is separated from the support 20 by the support winding section 32, and the resin molding 10 alone is wound up by the winding section 33. can be obtained in the form

(fine particles)
The resin molding obtained as described above may contain fine particles of an inorganic or organic compound for preventing blocking, imparting hardness, imparting antiglare and antistatic properties, or adjusting the refractive index.

The inorganic or organic compound fine particles are not particularly limited as long as they can be mixed with the photocurable composition. can.

The inorganic fine particles to be contained in the resin molding include oxides such as silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, tin oxide, and antimony pentoxide, and composite oxides such as antimony-doped tin oxide and phosphorus-doped tin oxide. can be used. In addition, calcium carbonate, talc, clay, kaolin, calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, etc. can also be used.

Examples of organic fine particles include polymethyl methacrylate acrylate resin powder, acrylic-styrene resin powder, polymethyl methacrylate resin powder, silicone resin powder, polystyrene powder, polycarbonate powder, melamine resin powder, polyolefin resin powder, and the like. can be used.

The average particle size of these fine particle powders is preferably 5 nm to 20 μm, more preferably 10 nm to 10 μm. Two or more kinds of these fine particles can also be used in combination. However, the fine particle diameter is selected within the range of the film thickness of the resin molding to be produced.

The resin molded article obtained in the present invention optionally has antireflection performance, antistatic performance, antifouling performance, antiglare performance, electromagnetic wave shielding performance, infrared absorption performance, ultraviolet absorption performance, or color correction performance. Functional layers may be laminated. In addition, these functional layers may be a single layer, or may be a plurality of layers. For example, the antireflection layer may be composed of a low refractive index single layer, or may be composed of a plurality of layers formed by repeating a low refractive index layer and a high refractive index layer. Also, the functional layer may have a plurality of functions in one layer, such as an antireflection layer having antifouling performance.

Examples are described below. However, the present invention is not limited by the following examples.

Japanese Unexamined Patent Application Publication No. 2013-159691 was referred to for the production method of urethane acrylate in producing the resin molding.

[Production of urethane acrylate 1]
31.5 parts by mass of "isophorone diisocyanate (IPDI)" and 0.1 part by mass of dibutyltin dilaurate are mixed in a reaction vessel equipped with a cooling pipe, a stirrer and a thermometer, and "ε- 68.4 parts by mass of 2-hydroxyethyl acrylate modified with 1 mol of caprolactone” was added dropwise over 1 hour and then stirred at 90°C for 10 hours.
When the amount of residual isocyanate in this reaction solution was measured using FT-IR, the urethanization reaction was carried out quantitatively, and finally the isocyanate disappeared. ) to obtain 99.9 parts by mass.

[Example 1]
80 parts by weight of "urethane acrylate 1" produced under the above conditions, 34.3 parts by weight of polyfunctional urethane acrylate "UV-7000B (Nippon Synthetic Chemical Industry), and photo-curing initiator "ESACURE ONE" (DKSH Japan)5. 72 parts by weight and 80 parts by weight of the solvent "methyl ethyl ketone" were mixed and stirred to prepare a photocurable composition.

Using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, the prepared photocurable composition was cured using an applicator so that the film thickness of the resin molding after curing was about 45 μm. It is applied and dried in an oven at 100° C. for 3 minutes, irradiated with a medium-wavelength carbon heater (maximum energy wavelength: 1.7 μm) as an infrared irradiation means, and a metal halide lamp as an ultraviolet irradiation means (illuminance of 350 mW/cm ² , integrated light intensity of 500 mJ/cm). ² ) The coating film was irradiated in the order of 2) irradiation to obtain a resin molding.
The composition ratio of the photo-curing initiator to the solid content in the photo-curing composition of the resin molding of this example, the film thickness, and the gel fraction are shown in Table 1 below.

[Example 2]
80 parts by weight of "urethane acrylate 1" produced under the above conditions, 34.3 parts by weight of polyfunctional urethane acrylate "UV-7000B (Nippon Synthetic Chemical Industry), and photocuring initiator "Irgacure 184 (1-hydroxycyclohexylphenyl ketone) )” (BASF) and 80 parts by weight of the solvent “methyl ethyl ketone” were mixed and stirred to prepare a photocurable composition.

Using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, the prepared photocurable composition was cured using an applicator so that the film thickness of the resin molding after curing was about 45 μm. It is applied and dried in an oven at 100° C. for 3 minutes, irradiated with a medium wavelength carbon heater (maximum energy wavelength 1.7 μm) as an infrared irradiation means, and a metal halide lamp as an ultraviolet irradiation means (illuminance 380 mW/cm ² , integrated light amount 180 mJ/cm). ² ) The coating film was irradiated in the order of 2) irradiation to obtain a resin molding.

[Example 3]
The same photocurable composition as in Example 2 was cured using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, and the film thickness of the resin molding after curing was about 45 μm using an applicator. and dried in an oven at 100 ° C. for 3 minutes, irradiated with a medium wavelength carbon heater (maximum energy wavelength 1.7 μm) as an infrared irradiation means, and a metal halide lamp as an ultraviolet irradiation means (illuminance 190 mW / cm ² , integrated A light amount of 180 mJ/cm ² ) was applied to the coating film, and a resin molding was obtained.

[Example 4]
The same photocurable composition as in Example 2 was cured using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, and the film thickness of the resin molding after curing was about 45 μm using an applicator. and dried in an oven at 100° C. for 3 minutes, irradiated with a metal halide lamp (illuminance of 380 mW/cm ² , integrated light intensity of 180 mJ/cm ² ) as an ultraviolet irradiation means, and a medium wavelength carbon heater (maximum The coating film was irradiated in the order of energy wavelength 1.7 μm irradiation, and a resin molded body was obtained.

[Example 5]
The same photocurable composition as in Example 2 was cured using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, and the film thickness of the resin molding after curing was about 45 μm using an applicator. and dried in an oven at 100° C. for 3 minutes, irradiated with a metal halide lamp (illuminance of 190 mW/cm ² , integrated light intensity of 180 mJ/cm ² ) as an ultraviolet irradiation means, and a medium wavelength carbon heater (maximum The coating film was irradiated in the order of energy wavelength 1.7 μm irradiation, and a resin molded body was obtained.

[Comparative Example 1]
The same photocurable composition as in Example 1 was cured using a transparent polyethylene terephthalate (PET) film (“Lumirror 75T60”: Toray Industries, Inc.) as a support, and the film thickness of the resin molding after curing was about 45 μm using an applicator. and dried in an oven at 100° C. for 3 minutes, followed by only ultraviolet irradiation from a metal halide lamp (illuminance 125 mW/cm ² , integrated light intensity 500 mJ/cm ² ) to obtain a resin molding.

[Comparative Example 2]
A resin molding was obtained in the same manner as in Example 2, except that the coating film formed on the support was cured by irradiating only ultraviolet rays.

[Comparative Example 3]
The same photocurable composition as in Example 2 except that the amount of the photocurable initiator “Irgacure 184” was changed to 11.3 parts by weight (composition ratio of 9.0%) was applied to a transparent polyethylene terephthalate (PET) film ( "Lumirror 75T60": Toray) was used as a support, and an applicator was used to apply the cured resin molding so that the film thickness of the cured resin molding was about 45 μm, dried in an oven at 100 ° C. for 3 minutes, and subjected to a metal halide lamp. Only UV irradiation (illuminance of 380 mW/cm ² , integrated light intensity of 180 mJ/cm ² ) was performed to obtain a resin molding.

(Method for measuring gel fraction)
The resin molded bodies prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were pulverized by freeze pulverization, weighed, and heated to reflux with MEK solvent for 8 hours by Soxhlet extraction. rice field. After the Soxhlet extraction, the residue of the resin molding was sufficiently dried and weighed. From the weight of the resin molding before and after Soxhlet extraction, each gel fraction was obtained by the following formula (1).
Gel fraction (%) = 100 x (weight of resin molding after Soxhlet extraction)/(weight of resin molding before Soxhlet extraction) (1)

Table 1 shows the conditions, film thickness, and gel fraction of each of the above Examples and Comparative Examples.

From Table 1, in Examples 1 to 5 in which infrared irradiation was performed before and after ultraviolet irradiation, all of the resin moldings had a gel fraction exceeding 94.2% obtained by (100-A-1). Thus, the curing reaction proceeded sufficiently as a resin molding, and the elution of the remaining initiator and the like was suppressed.
On the other hand, in Comparative Examples 1 and 2 in which the resin molding was produced without infrared irradiation, the gel fraction was below (100-A-1)%, and the remaining unreacted photocuring initiator and curing It was suggested that the durability and physical properties deteriorated due to the elution of the components of the resin molding into the solvent due to the large amount of resin components.
Comparative Example 3, in which the composition ratio of the photocuring initiator was increased to 9%, also had a gel fraction of 88.7%, which was lower than (100-A-1) (=90%).

From the above results, in all of Examples 1 to 5, the gel fraction was improved compared to Comparative Examples 1 to 3 in which infrared irradiation was not performed. Therefore, the amount of unreacted residue of the photocuring initiator is suppressed, and the elution of the component when it comes into contact with a solvent is small, and the lamination process when forming a laminate and lamination using this resin molding as a base material It was able to be applied to the coating process for

The resin molding of the present invention and its manufacturing method are used for optical display devices such as liquid crystal display devices, plasma display devices, electrochromic display devices, light-emitting diode display devices, EL display devices, and touch panels, packaging materials, building materials, and the like. It can be used for functional films and the like.

Reference numerals 10 : Resin molded body 20 : Support body 31 : Support unwinding part 32 : Support winding part 33 : Resin molded body winding Part 41... Coating part 42... Drying part 50... Curing unit 51 for resin molding... Ultraviolet irradiation part 52... Infrared irradiation part 52a... ... Infrared irradiation section 52b before ultraviolet irradiation ... Infrared irradiation section after ultraviolet irradiation

Claims (4)

A photocurable composition comprising at least two different urethane (meth)acrylates having a urethane skeleton and two or more (meth)acryloyl groups, which are urethane (meth)acrylates, and a photocuring initiator, When the thickness is 20 μm or more and 100 μm or less, and the composition ratio of the photocuring initiator in the solid component in the photocurable composition is A%, the gel fraction of the resin molding is (100-A- 1) A method for producing a resin molded product having a irradiating with infrared rays having a maximum energy wavelength of 1.2 to 2.7 μm at least either before or after irradiation, wherein the irradiation amount of the ultraviolet rays is 100 to 2000 mJ/cm ² , and the infrared rays A method for producing a resin molding, wherein the irradiation amount is 60 to 150 KW/m ² . 2. The method of manufacturing a resin molded product according to claim 1, further comprising a step of separating the resin molded product formed on said support from said support. 3. The production of the resin molding according to claim 1, further comprising a step of drying the coating film after the step of coating the photocurable composition on a support to form a coating film. Method. 4. The method for producing a resin molding according to claim 3, wherein the flexible base material used as the support is conveyed by roll-to-roll.

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