JP5371194B2 - Molded body and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding which can diffract incident light at a specified position to obtain a specified spot-like diffraction pattern, and to provide a method for producing the molding. <P>SOLUTION: The method for producing the molding from a photo-polymerizable resin composition includes the process of packing the resin composition in a mold and the process of irradiating the resin composition packed in the mold with parallel light made to pass through an optical system including an integrator lens 34 to polymerize/cure the resin composition, and the molding is formed which has a phase separation structure comprising a matrix made of the resin composition and a plurality of columnar structures which are arranged in a prescribed pattern to be set in the matrix and have a refractive index different from that of the matrix. In the integrator lens, a plurality of lens parts are arranged in the shape of a hexagonal lattice, and the columnar structures are arranged in the shape of the hexagonal lattice in the matrix. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a molded body and a method for manufacturing the same, and more particularly to a molded body such as an optical film having a light control function such as diffraction and a method for manufacturing the same. More specifically, the present invention relates to a molded body that can be used for, for example, an optical low-pass filter that is a filter for preventing moire in a digital camera, and a method for manufacturing the same.

  Since polymer materials have a wide variety of materials that can be selected and can give various functions to products, attempts to use them as materials for optical parts have been actively made in recent years. Among optical components using a polymer material, a polymer film having a one-dimensional or two-dimensional microstructure formed therein can be used as a light control plate or a light diffraction plate.

  In particular, in a thin plate-like matrix, a film in which a large number of columnar structures with different refractive indexes and orientations are arranged in a matrix is arranged when light parallel to the axis of the columnar structure is incident. Since the incident light is diffracted in accordance with the arrangement, it can be used as an optical diffraction plate for diffracting the incident light.

  As a film having such a light control function and a method for producing the same, a photopolymerizable resin composition is polymerized and cured by parallel light, and a plurality of rod-shaped cured regions (columnar structures) having different refractive indexes are formed inside. A method of manufacturing a body is known (see Patent Document 1).

JP 2005-265915 A

However, in the molded body manufactured by the manufacturing method disclosed in Patent Document 1, since the arrangement of the columnar structures formed inside is not regular, when light is incident from the axial direction of the columnar structures The transmission pattern is not a spot-like diffraction pattern, but a light diffusion pattern using a columnar structure as a scattering source.
For this reason, this molded body has a problem that it can be used as an anisotropic diffusion medium or the like, but cannot be used as an optical low-pass filter or the like that needs to diffract incident light to a specific position. .

  The present invention has been made to solve such a problem, and provides a molded body capable of diffracting incident light to a specific position and obtaining a specific spot-like diffraction pattern, and a method for manufacturing the same. The purpose is to provide.

According to the present invention,
A method for producing a molded body using a photopolymerizable resin composition,
Filling the mold with the photopolymerizable resin composition;
The photopolymerizable resin composition filled in the mold is irradiated with parallel light via an optical system including an integrator lens to polymerize and cure the photopolymerizable resin composition, and is composed of the photopolymerizable resin composition. Forming a molded body having a phase separation structure including a matrix and a plurality of columnar structures that are arranged in a predetermined pattern in the matrix and have a refractive index different from that of the matrix. The lens parts are arranged in a hexagonal lattice shape, and the parallel light is irradiated to the photopolymerizable resin composition filled in the mold without passing through a photomask, and the columnar structure is A method for producing a molded body is provided, which is arranged in a hexagonal lattice pattern in a matrix.

  According to such a structure, the molded object which can provide the hexagonal lattice-like diffraction spot can be provided.

  According to another preferred embodiment of the present invention, the photopolymerizable resin composition is made of an acrylic resin.

  ADVANTAGE OF THE INVENTION According to this invention, a molded object which can diffract incident light to a specific position and can obtain a specific spot-like diffraction pattern and its manufacturing method are provided.

  Hereinafter, a molded body and a method for manufacturing the same according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. First, the structure of the molded body according to a preferred embodiment of the present invention will be described.

  FIG. 1 is a schematic perspective view in which a part of a molded body according to a preferred embodiment of the present invention is broken. As schematically shown in FIG. 1, the molded body 1 has a thin plate shape (film shape) with a substantially constant thickness, a matrix 2 as a substrate, and a large number of columnar structures disposed in the matrix 2. 4 and a phase separation structure.

Each of the columnar structures 4 has substantially the same shape, and its axis A is oriented in the matrix 2 so as to extend in the thickness direction of the molded body 1 and is regularly arranged in a hexagonal lattice shape. Is arranged.
The matrix 2 and the columnar structure 4 are both light transmissive, but have different refractive indexes. The refractive index difference between the matrix 2 and the columnar structure 4 is not limited to this, but may be 0.0001 or more, preferably 0.001 or more, more preferably 0.01 or more. .

  In general, the molded body 1 has a film shape with a constant thickness, but may have another shape, for example, a film shape whose thickness varies along the width direction depending on the application.

  In this embodiment, each columnar structure 4 is arranged such that the orientation direction (axial direction) A is substantially the same as the thickness direction B of the molded body 1, but the orientation direction A is the same as that of the molded body 1. You may arrange | position so that a predetermined angle may be made with respect to the thickness direction B. In addition, the columnar structure 4 has a columnar shape, but is not limited thereto, and the columnar structure 4 may have a columnar shape such as an ellipse or a rectangle.

Next, the manufacturing method of the molded object 1 of this embodiment is demonstrated.
FIG. 2 is a plan view of a molding die (cell) 10 that is filled with a photopolymerizable resin composition as a raw material when the molded body 1 of the present embodiment is manufactured. FIG. It is sectional drawing of the shaping | molding die 10 along the -III line.

  The mold 10 includes a thin box-shaped main body 12 that opens upward. A space 14 filled with the photopolymerizable resin composition is formed inside the main body 12. The space portion 14 has a shape corresponding to the shape of the molded body 1 to be manufactured. In the present embodiment, the space portion 14 is a thin-film or thin-plate space having a constant thickness.

  The mold 10 includes a cover 18 that covers the open end of the main body 12 after the space 14 is filled with the photopolymerizable resin composition 16. In the present embodiment, the photopolymerizable resin composition 16 filled in the space 14 is irradiated through the cover 18 with parallel irradiation light from the thickness direction of the mold 10, and the photopolymerizable resin composition 16 is irradiated with light. Since the molded body is manufactured by polymerization, the cover 18 is made of a light-transmitting material having no optical absorption with respect to the wavelength of the irradiation light.

  For example, Pyrex (registered trademark) glass, quartz glass, fluorinated (meth) acrylic resin, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), triacetyl cellulose (TAC), polycarbonate (PC), polyvinyl alcohol (PVA) Transparent plastic materials such as polyarylate, polyethylene (PE), polyimide (PI), polyethersulfone (PES), polypropylene (PP), and cycloolefin resin are used as the material for the cover 18.

  In the present embodiment, it is preferable to enclose the photopolymerizable resin composition 16 in a liquid-tight manner in the space portion 14 so that the photopolymerization resin composition does not come into contact with air and photopolymerization is not inhibited.

In addition, the space part 14 is made into various shapes according to the shape of the molded object 1 to shape | mold. For example, when obtaining a film-shaped molded body, a gap may be provided between two glass plates, and the photopolymerizable resin composition may be held in the gap.
Further, a gap may be provided between the two transparent plastic films, and the photopolymerizable resin composition may be held in the gap. In this case, two long transparent plastic films are unwound from a roll and conveyed while maintaining a gap therebetween, and the gap is filled with a photopolymerizable resin composition, and then light irradiation is performed. Therefore, it is also possible to manufacture the molded body 1 continuously.

FIG. 4 is a drawing schematically showing an arrangement in carrying out the molded body manufacturing method according to a preferred embodiment of the present invention.
As shown in FIG. 4, in the present embodiment, the photopolymerizable resin composition 16 enclosed in the space 14 of the mold 10 is irradiated with the parallel irradiation light 22 of the irradiation light source 20, The molded body 1 is obtained by polymerizing and curing the photopolymerizable resin composition 16.

The irradiation light source 20 divides the irradiation area 24 into a plurality of areas as shown in FIG. 5 (9 areas in the present embodiment), measures the light intensity of the points 26a to 26i in each area, and gives the following expression: Although the value of the illuminance distribution to be used is 2.0% or less, the value of the illuminance distribution is more preferably 1.0% or less.
Illuminance distribution = (maximum value−minimum value) / (maximum value + minimum value) × 100 (formula)

Next, the configuration of the illumination light source 20 will be described. FIG. 6 is a drawing schematically showing the configuration of the optical system of the irradiation light source 20 used in the present embodiment.
The illumination light source 20 includes a lamp 28 that generates irradiation light, an elliptical condenser mirror 30 that is disposed on the back side of the lamp 28 and collects light from the lamp 28, and a light flux L from the lamp 28 and the elliptical condenser mirror 30. Is provided.

In the present embodiment, as the lamp 28, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a deep-UV lamp, a carbon arc lamp, a chemical lamp, a metal halide lamp, a xenon lamp, or the like is used.
The wavelength to be used must include a wavelength capable of curing the photocurable resin, and is selected according to the absorption wavelength of the initiator to be used. The high pressure mercury lamp, ultrahigh pressure mercury lamp, low pressure mercury lamp, Deep- In lamps using mercury, such as UV lamps, 313 nm (j-line), 365 nm (i-line) in the ultraviolet region, and 405 nm (h-line) and 436 nm (g-line) in the visible region are mercury photo-initiators. It can be used if it is selected appropriately. In the case of other lamps, light having a wavelength range corresponding to the absorption wavelength of the photoinitiator is used.
Further, in the present invention, in order to obtain a regular arrangement of the columnar structures, it is preferable that the wavelength width of the irradiation light is narrow. Therefore, the full width at half maximum is preferably 100 nm or less, and preferably 20 nm or less. More preferred.

  The illumination light source 20 includes an integrator lens 34 through which light from the plane mirror 32 enters through a shutter.

  On the downstream side of the integrator lens 34, a shutter 36, a filter 38, and a concave mirror 40 are disposed. In the present embodiment, the light beam L transmitted through the filter 34 is converted into parallel light by the concave mirror 40 and is irradiated toward the photopolymerizable resin composition 16 enclosed in the space 14 of the mold 10. . Instead of the concave mirror 40, the collimator lens may be used to make the light beam that has passed through the filter 34 into parallel light.

  FIG. 7 is a plan view of the integrator lens 34, and FIG. 8 is a side view of the integrator lens 34. The integrator lens (fly eye lens) 34 has a structure in which a plurality of lens portions 34a are two-dimensionally arranged in a predetermined arrangement, and the integrator lens 34 of the present embodiment is as shown in FIG. In addition, the lens portions 34a formed of convex lenses that are single lenses are arranged in a hexagonal lattice pattern. However, instead of the convex lens, a concave lens, a cylindrical lens, a refractive index distribution lens, or the like may be used.

  The light intensity distribution in the cross section perpendicular to the traveling direction of the light beam incident on the integrator lens 34 is made constant.

  When using an integrator lens and a concave mirror, the parallelism of parallel light is given by a collimation half angle. The smaller this value, the higher the parallelism. In the present embodiment, the collimation half angle is preferably 10 ° or less, and more preferably 5 ° or less.

  As shown in FIG. 4, the parallel light from the irradiation light source 20 having such a configuration is irradiated onto the photopolymerizable resin composition 16 enclosed in the space portion 14 of the mold 10 and photopolymerization is performed. The resin composition 16 is polymerized and cured to form the molded body 1.

  The photopolymerizable resin composition 16 enclosed in the space 14 of the mold 10 is irradiated with parallel light from the irradiation light source 20 including the optical system including the integrator lens 34 in which the convex lenses are arranged in a hexagonal lattice. When the molded body 1 is produced by photopolymerization, a large number of columnar structures 4 are formed in the molded body 1, which has a refractive index different from that of the surrounding matrix 2 and is oriented in the incident direction of parallel light. The columnar structures 4 are arranged in a hexagonal lattice pattern in a plane perpendicular to the light incident direction (that is, in the surface of the thin plate or film-shaped molded body 1).

  When light parallel to the axis of the columnar structure 4 is incident on the shaped body 1 having such a structure, a hexagonal lattice-shaped diffraction spot corresponding to the arrangement of the columnar structure 4 is obtained.

When the photopolymerizable resin composition is irradiated with parallel light, a large number of columnar structures having a refractive index different from that of the matrix are formed in the molded body 1 as a result of photopolymerization of the photopolymerizable resin composition. Although the principle of forming is not necessarily clarified, it is considered that the polymerization reaction of the photopolymerizable resin composition proceeds in a spatially non-uniform manner to form microstructures (columnar structures) having different refractive indexes.
At this time, this microstructure (columnar structure) is regularly arranged by polymerizing the photopolymerizable resin composition with parallel light from an irradiation light source equipped with an integrator lens in which single lenses are arranged in a hexagonal lattice shape. Be made.
Here, the single lens means a lens of a minimum unit constituting an integrator such as a convex lens, a concave lens, a cylindrical lens, and a refractive index distribution lens.

  Below, the material which can be used for the photopolymerizable resin composition 16 is demonstrated.

(Polyfunctional monomer)
The photopolymerizable resin composition 16 preferably contains a polyfunctional monomer. As such a polyfunctional monomer, a (meth) acryl monomer containing a (meth) acryloyl group, a monomer containing a vinyl group, an allyl group, or the like is particularly preferable.

  Specific examples of the polyfunctional monomer include triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6 -Hexanediol di (meth) acrylate, hydrogenated dicyclopentadienyl di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Tetramethylolmethane tetra (meth) acrylate, pentaerythritol hexa (meth) acrylate, polyfunctional epoxy (meth) acrylate, polyfunctional urethane (meth) acrylate, divinylbenzene, toluene Examples include allyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diallyl chlorendate, N, N′-m-phenylenebismaleimide, diallyl phthalate, and the like. These may be used alone or as a mixture of two or more. can do.

  Among them, the polyfunctional monomer having 3 or more polymerizable carbon-carbon double bonds in the molecule tends to increase the crosslink density due to the difference in the degree of polymerization, and the above-described columnar structure is easily formed.

  Particularly preferred polyfunctional monomers having three or more polymerizable carbon-carbon double bonds are trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, penta There is erythritol hexa (meth) acrylate.

  When two or more kinds of polyfunctional monomers or oligomers thereof are used as the polymerizable composition, it is preferable to use those having different refractive indexes when the respective homopolymers are used, and the difference in refractive index is large. It is more preferable to combine them.

  In order to obtain a light control function such as diffraction with high efficiency, it is necessary to increase the refractive index difference, and the refractive index difference is preferably 0.01 or more, preferably 0.05 or more. More preferably. Further, since the difference in refractive index is increased by the diffusion of the monomer during the polymerization process, a combination having a large difference in diffusion constant is preferable.

  In addition, when using 3 or more types of polyfunctional monomers or oligomers, the refractive index difference between at least any two of the respective homopolymers may be within the above range. In addition, the two monomers or oligomers having the largest refractive index difference of the homopolymer should be used in a weight ratio of 10:90 to 90:10 in order to obtain highly efficient functions such as diffraction, deflection, and diffusion. Is preferred.

(Monofunctional monomer)
Further, as the photopolymerizable resin composition 16, a monofunctional monomer or oligomer having one polymerizable carbon-carbon double bond in the molecule may be used together with the polyfunctional monomer or oligomer as described above. As such a monofunctional monomer or oligomer, a (meth) acryl monomer containing a (meth) acryloyl group, a monomer containing a vinyl group, an allyl group, or the like is particularly preferable.

  Specific examples of the monofunctional monomer include, for example, methyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, ethyl carbitol (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, phenyl Carbitol (meth) acrylate, nonylphenoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, (meth) acryloyloxyethyl succinate, (meth) acryloyloxyethyl phthalate, phenyl (meth) acrylate , Cyanoethyl (meth) acrylate, Tribromophenyl (meth) acrylate, Phenoxyethyl (meth) acrylate, Tribromophenoxyethyl (meth) acrylate, Ben (Meth) acrylate, p-bromobenzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) ) (Meth) acrylate compounds such as acrylate; vinyl compounds such as styrene, p-chlorostyrene, vinyl acetate, acrylonitrile, N-vinyl pyrrolidone, vinyl naphthalene; allyl compounds such as ethylene glycol bisallyl carbonate, diallyl phthalate, diallyl isophthalate Etc.

  These monofunctional monomers or oligomers are used for imparting flexibility to the molded article 1, and the amount used is preferably in the range of 10 to 99% by mass of the total amount with the polyfunctional monomers or oligomers. A range of 50% by mass is more preferred.

(Polymer, low molecular weight compound)
Furthermore, the photopolymerizable resin composition 16 may be a homogeneous solution mixture containing the polyfunctional monomer or oligomer and a compound having no polymerizable carbon-carbon double bond.
Examples of the compound having no polymerizable carbon-carbon double bond include polymers such as polystyrene, polymethyl methacrylate, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl alcohol, and nylon, toluene, n-hexane, cyclohexane, acetone, and methyl ethyl ketone. , Low molecular weight compounds such as methyl alcohol, ethyl alcohol, ethyl acetate, acetonitrile, dimethylacetamide, dimethylformamide, and tetrahydrofuran, organic halogen compounds, organosilicon compounds, plasticizers, additives such as stabilizers, and the like.

  These compounds having no polymerizable carbon-carbon double bond are used for adjusting the viscosity of the photopolymerizable resin composition 16 to improve the handleability when the molded body 1 is produced, and the amount used is large. The total amount of the functional monomer or oligomer is preferably in the range of 1 to 99% by mass, and 1 to 50% by mass in order to form a columnar structure having a regular arrangement while improving the handleability. The range of is more preferable.

(Initiator)
The photopolymerization initiator used for the photopolymerizable resin composition 16 is not particularly limited as long as it is used in normal photopolymerization in which polymerization is performed by irradiating active energy rays such as ultraviolet rays. , Benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, benzoin ethyl ether, diethoxyacetophenone, pt-butyltrichloroacetophenone, benzyldimethyl ketal, 2-hydroxy-2-methylpropylphenone, 1-hydroxycyclohexyl phenyl ketone, 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, dibenzosuberone and the like.

  The use amount of these photopolymerization initiators is preferably in the range of 0.001 to 10% by mass with respect to the weight of the other photopolymerizable resin composition, so that the transparency of the molded body 1 is not deteriorated. For this purpose, the content is more preferably 0.01 to 5% by mass.

  Without being limited to the above-described embodiment of the present invention, various changes and modifications can be made within the scope of the technical idea described in the claims.

Examples of the present invention will be described.
Example 1
In a mixture composed of 30 parts by mass of phenoxyethyl acrylate and 70 parts by mass of trimethylolpropane trimethacrylate, 0.6 part by mass of 1-hydroxycyclohexyl phenyl ketone was dissolved to obtain a photopolymerizable resin composition. The obtained photopolymerizable resin composition was encapsulated in a film form in a glass cell having a diameter of 20 mm and a thickness of 0.2 mm. Next, from the direction perpendicular to the surface, the light intensity distribution is substantially constant, and the collimation half angle from the parallel light irradiation device using the integrator lens in which the lenses are arranged in a hexagonal lattice is 0.9 ° The photopolymerizable resin composition was polymerized and cured by irradiation with light at 2500 mJ / cm 2 to obtain a plastic film.

  The optical microscope image of the obtained plastic film is shown in FIG. Columnar structures having a diameter of 2 microns were arranged in a hexagonal lattice with a pitch of 6 microns in a cross section perpendicular to the alignment direction. Further, when a diffraction pattern was evaluated by irradiating a laser beam having a wavelength of 633 nm perpendicular to the surface of the plastic film, a hexagonal diffraction reflecting a regular phase separation structure inside the polymer as shown in FIG. A spot was observed.

[Comparative Example 1]
A photopolymerizable resin composition having the same composition as that of Example 1 was encapsulated in a film shape in a glass cell having a diameter of 20 mm and a thickness of 0.2 mm. Next, from the direction perpendicular to the surface, the light intensity distribution is substantially constant, and the photopolymerizable resin composition is polymerized and cured by irradiating 2500 mJ / cm 2 with collimated ultraviolet light without using an integrator lens, and a plastic film Got.

  An optical microscope image of the obtained plastic film is shown in FIG. The diameter of the obtained columnar structure was about 1 micron, and the arrangement of the columnar structures inside the molded body was not regular and random. Further, when a diffraction pattern was evaluated by irradiating a laser beam having a wavelength of 633 nm perpendicular to the surface of the plastic film, no clear diffraction spot was observed as shown in FIG.

It is the typical perspective view which fractured | ruptured a part of the molded object of preferable embodiment of this invention. It is a top view of the shaping | molding die (cell) with which the photopolymerizable resin composition used as a raw material is filled when manufacturing the molded object of this embodiment of this invention. It is sectional drawing along the III-III line of FIG. It is drawing which shows the arrangement | positioning at the time of enforcing the molded object manufacturing method of preferable embodiment of this invention. It is drawing which shows distribution of the light intensity of the irradiation light source used with the molded object manufacturing method of preferable embodiment of this invention. It is drawing which shows typically the structure of the irradiation light source used by preferable embodiment of this invention. It is a top view of the integrator lens with which the irradiation light source used by preferable embodiment of this invention is provided. FIG. 8 is a side view of the integrator lens shown in FIG. 7. It is an optical microscope image of the plastic film (molded object) of the Example of this invention. It is a diffraction image by the molded object of FIG. It is an optical microscope image of the plastic film (molded article) of a comparative example. It is a diffraction image by the molded object of FIG.

Explanation of symbols

1: Molded body 2: Matrix 4: Columnar structure 10: Mold (cell)
12: Body 14: Space 16: Photopolymerizable resin composition 18: Cover 20: Irradiation light source 28: Lamp 34: Integrator lens

Claims (2)

A method for producing a molded body using a photopolymerizable resin composition,
Filling the mold with the photopolymerizable resin composition;
The photopolymerizable resin composition filled in the mold is irradiated with parallel light via an optical system including an integrator lens to polymerize and cure the photopolymerizable resin composition, and is composed of the photopolymerizable resin composition. Forming a molded body having a phase separation structure composed of a matrix and a plurality of columnar structures having a refractive index different from that of the matrix disposed in the matrix in a predetermined pattern,
The integrator lens is configured by arranging a plurality of lens portions in a hexagonal lattice shape,
The parallel light is irradiated to the photopolymerizable resin composition filled in the mold without passing through a photomask,
The columnar structures are arranged in a hexagonal lattice in the matrix,
The manufacturing method of the molded object characterized by the above-mentioned. The photopolymerizable resin composition is made of an acrylic resin.
The manufacturing method of the molded object of Claim 1.

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