JP2002225044A - Method for manufacturing optical article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical article such as a fine optical lens or the like with high accuracy. SOLUTION: The method for manufacturing the optical article changed in its thickness corresponding to the ionizing radiation transmissivity of a mask includes a process for applying some physical change to an ionizing radiation curable resin composition containing a phase transition resin component, which has a function bringing about phase transition from a sol to 'a gel capable of being differentiated from an ionizing radiation cured part' by some physical change, to generate the phase transition to the gel, a process for irradiating the gel of the ionizing radiation curable resin composition at least from one arbitray direction through the mask of which the ionizing radiation transmissivity changes in-plane to cure the ionizing radiation curable resin composition and a process for removing 'the gel capable of being differentiated from the ionizing radiation cured part'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing optical articles such as a cylindrical lens, a prism lens and a Fresnel lens.

[0002]

2. Description of the Related Art Conventionally, the following method has been used for producing a lens. This method of machining a material into a lens by machining is suitable when a hard material such as quartz glass is used directly as a lens, and the processing method is generally to cut and polish the material. In many cases, contact lenses are processed by this method.

In order to process a lens using an inverted lens, it is necessary to prepare an inverted mold in which the inverted shape of the lens is cut into a flat plate in advance. Extrusion molding and injection molding of resin,
Alternatively, it is possible to process a large number of lenses having the same shape by filling an ionizing radiation-curable resin into an inversion mold and performing ionizing radiation curing.

This method processes a lens using ionizing radiation curing through a mask. This method involves irradiating ionizing radiation-curable resin with ionizing radiation through a mask whose transmittance has changed according to the shape of the lens. By curing, a large number of lenses having the same shape can be processed.

[0005]

Optical lenses such as a prism lens used for a liquid crystal display and a Fresnel lens used for a projection television are necessary members for clearly displaying an image to an observer. In such an image display device, the pixel size has been reduced due to technological advances over the years, and a high-definition image can be displayed. However, in the above image display device, even if the pixel size is reduced, a high-definition image cannot be displayed unless the optical lens is miniaturized accordingly. A cutting step is required regardless of whether the optical lens is processed by any of the above methods or both methods, and a high-precision cutting machine is required to process a fine optical lens. However, no matter how high-precision the cutting machine is, there is a limit to miniaturization due to cutting. Also,
In the case of the above method, since the ionizing radiation-curable resin is in a liquid state, a flow occurs in the ionizing radiation-curable resin during curing due to the influence of vibration and the like, and the processing accuracy of the lens is reduced. is there.

Accordingly, an object of the present invention is to provide a method for manufacturing an optical article such as a fine optical lens with high accuracy.

[0007]

Means for Solving the Problems The invention according to the present application which solves the above-mentioned problems has a function of causing a phase transition from a sol to a “gel that can be differentiated from an ionized radiation-cured portion” by some physical change. A step of imparting some physical change to the ionizing radiation-curable resin composition containing the phase-change resin component to cause a phase transition to a gel;
A step of irradiating the gel of the ionizing radiation-curable resin composition with ionizing radiation from at least one arbitrary direction through a mask having a transmittance varying in a plane to cure the ionizing radiation-curable resin composition; Removing the “gel that can be differentiated from the ionized radiation-cured portion”; a method for manufacturing an optical article having a thickness that changes in accordance with the ionizing radiation transmittance of the mask. It is.

In the present invention, the step of irradiating ionizing radiation from at least one arbitrary direction to cure the ionizing radiation-curable resin composition may comprise irradiating ionizing radiation from two or more directions. The method for producing an optical article described above is a step of curing the ionizing radiation-curable resin composition.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the terms used in the present specification have the following meanings. Regarding "Phase change resin component", "Phase change resin component having the function of causing a phase transition from sol to" gel that can be differentiated from ionized radiation cured part "by some physical change"
(Hereinafter, this may be referred to as “sol-gel transition component”.) When the phase-transition resin component is mixed with the ionizing radiation-curable resin component, at least one of the ionizing radiation-curable resin components is used. Due to physical interaction with the part, the state of "glass transition" as observed in ordinary resin is not observed, and "phase transition from sol to gel" or "phase transition from gel to sol" occurs It is a component that exhibits properties. More specifically, for example, a normal resin gradually softens from a glass transition temperature (Tg) as the temperature is increased. For example, a phase change resin component is referred to as "some physical change". When the material was at a temperature, the ionizing radiation-curable resin composition containing the phase-change resin component did not show a state of "glass transition" even when the temperature was gradually increased (therefore, the glass transition was not observed). (No temperature is observed.) At a certain temperature, the viscosity rapidly decreases to form a sol.

Here, "some physical change" means a change in temperature, light irradiation, or the like.
The term “temperature change” includes both a change from high temperature to low temperature and a change from low temperature to high temperature.

The “gel that can be differentiated from the ionized radiation-cured portion” means, for example, that when immersed in a solvent, the ionized radiation-cured portion does not dissolve, but the ionized radiation-cured gel does not. If the part dissolves; when it causes a phase transition from gel to sol,
This means a case where the ionized radiation-cured portion does not fluidize, while the gel portion that has not been ionized radiation-cured becomes fluidized by phase transition to a sol.

"Ionizing radiation" refers to ultraviolet rays, gamma rays,
X-ray, electron beam, charged particle beam, neutron beam, etc.

Hereinafter, the present invention will be described in detail with reference to the drawings. 1 and 2 show an outline of a method for producing an optical article of the present invention. An ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition is poured into a container 3 that is permeable to ionizing radiation. At this time, when the “some physical change” is a temperature change from a high temperature to a low temperature, the ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition is heated into a liquid sol state to form a container 3. , And after cooling, may be transformed into a solid gel state.

Next, through a mask 4 in which the transmittance of ionizing radiation varies in the plane, the container 3 can be viewed from any one direction (shown in FIG. 1) or from a plurality of more directions (see FIG. 1). (Shown in FIG. 2). Ionizing radiation-curable resin composition 1 containing a sol-gel transition component
The amount of the resin that cures varies depending on the amount of active energy given by the ionizing radiation 2, and as a result, the thickness of the cured product after removing the uncured portion varies according to the irradiation amount of the ionizing radiation. That is, immediately below the portion of the mask 4 having high transmittance of ionizing radiation, the ionizing radiation 2 can reach deep into the ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition. While the thickness is increased, immediately below the low ionizing radiation transmittance portion, the ionizing radiation 2 cannot reach the depth of the ionizing radiation-curable resin composition 1 containing the sol-gel transition component, The thickness of the cured product is reduced. Therefore, by using a mask in which the transmittance of ionizing radiation is continuously changed, it becomes possible to manufacture an optical lens or an optical component whose thickness changes continuously.

Further, by using a method of irradiating ionizing radiation from a plurality of directions through a mask as shown in FIG. 2, an optical article conventionally required to be manufactured by assembling or bonding a plurality of things. Can be manufactured as an optically uniform optical article having no assembly or bonding surface.

FIGS. 1 and 2 show a sealed container that transmits ionizing radiation. However, ionizing radiation obtained by adding a component that undergoes a sol-gel transition to a container having an opening that does not transmit ionizing radiation. A method of irradiating ionizing radiation through a mask through an opening after injecting the curable resin composition; coating an ionizing radiation-curable resin composition containing a component that undergoes a sol-gel transition on one surface of a film that transmits ionizing radiation. A method of preparing a sheet attached thereto, arranging a mask on the other surface, and irradiating the sheet with ionizing radiation through the mask; a polyhedron in a gel state of an ionizing radiation-curable resin composition containing a component that undergoes a sol-gel transition Alternatively, there is a method in which a spherical body is prepared and the polyhedron or spherical body is directly irradiated with ionizing radiation through a mask (not through a container), and the method is not limited to the above.

The present invention using an ionizing radiation-curable resin composition containing a component that undergoes a sol-gel transition is very useful for producing fine optical articles such as microlenses. That is, the liquid ionizing radiation-curable resin composition 1
When 2 is used, a flow occurs in the ionizing radiation-curable resin composition 12 during curing due to the vibration of the apparatus, and the processing accuracy of the molded body is reduced, or as shown in FIG. Since the molded body 13 is formed in the molded body 12, a phenomenon that the molded body 13 warps occurs. Therefore, it is desirable to cure the ionizing radiation-curable resin composition in a solid state, but a general ionizing radiation-curable resin composition is mainly composed of a monomer or oligomer of an organic compound, or a polymer is dissolved in a solvent. Therefore, it is difficult to solidify. On the other hand, when an ionizing radiation-curable resin composition containing a component that undergoes sol-gel transition is used, it is possible to easily cause a change from a sol in a liquid state to a gel in a solid state, Optical articles such as lenses can be manufactured from gels. Therefore, since no flow occurs in the ionizing radiation-curable resin composition 1, the processing accuracy does not decrease and the problem of warpage does not occur. In the method of irradiating ionizing radiation by disposing a mask on a plurality of surfaces described above, the ionizing radiation-curable resin composition is gelled, so that handling is easy and alignment in each direction can be facilitated. It has the feature of.

In the present invention, a gray scale mask such as a liquid crystal display or a photographic negative film can be used as the mask. In particular, when a photographic negative film is used, it can be manufactured by reducing the original gray scale by exposure, and thus is suitable for obtaining a mask having a fine pattern. Alternatively, a mask in which the transmittance of ionizing radiation changes in the plane due to the partial change in the thickness of the same material may be used. However, the mask used in the present invention is not limited to the above, and may be any mask that can partially change the transmittance of ionizing radiation in a plane.

FIGS. 3 and 4 show examples of the mask used in the present invention. In both figures, white portions indicate high transmittance of ionizing radiation, and darker portions indicate lower transmittance of ionizing radiation. Therefore, the transmittance of the mask shown in FIG. 3 decreases concentrically from the center, and a lens having a convex central portion can be manufactured by using this mask. FIG.
Since the mask of (1) has a band-like change in the transmittance of ionizing radiation, parallel cylindrical lenses can be manufactured. Of course, photosensitive properties such as curing depth and critical exposure amount vary greatly depending on the composition of the ionizing radiation-curable resin composition,
It goes without saying that a mask must be used according to the photosensitive characteristics of the ionizing radiation-curable resin composition to be used. Further, by using a mask other than the above-described mask, a prism lens or a Fresnel lens can be manufactured. It is also possible to manufacture optical articles of various sizes by changing the size of the mask.

Further, as shown in FIG. 5, by forming one surface of the container 6 to be non-planar, a molded body 8 having a shape similar to a contact lens having a non-planar shape on the incident surface side of ionizing radiation is manufactured. You can also.

The component which undergoes a sol-gel transition used in the present invention is preferably a reversible rapid phase-transition resin having a function of causing a reversible and rapid sol-gel phase transition by a change in temperature. Such components include:
Syndiotactic polymethyl methacrylate, syndiotactic polyisobutyl methacrylate, syndiotactic polybenzyl methacrylate, syndiotactic polymethacrylic acid Mixtures comprising a syndiotactic polymethacrylate such as methallyl and an isotactic polymethacrylate such as isotactic polymethyl methacrylate are known (for example, JP-A-4-6562 and JP-A-4-6562). -22509, JP-A-6-332
176, JP-A-7-281426, JP-A-8-281669, J.SPEVACEK and B.SCHNEID
ER, AGGREGATION OF STEREOREGULAR POLY (METHYL ME
THACRYLATES), Advancesin Colloid and Interface
Science, 27 (1987) 81-150). Further, as a component that undergoes a sol-gel transition, one that causes a phase transition from a sol to a gel with an increase in temperature is also known (JP-A-9-192469, JP-A-9-2273).
No. 29, JP-A-10-77201, JP-A-1
0-101518, JP-A-11-169703).

When a mixture of a syndiotactic polymethacrylate and an isotactic polymethacrylate is used as the sol-gel transition component, the syndiotactic polymethacrylate may be syndiotactic in the polymer. Triads (three consecutive monomer units) have a proportion of 50% or more, preferably 60% or more of all monomer units. As an isotactic polymethacrylate, isotactic polymethacrylic acid ester may be used. Those having a proportion of at least 50%, preferably at least 60% of the total monomer units are used. Further, as the syndiotactic polymethacrylate and the isotactic polymethacrylate, those having a weight average molecular weight of preferably 1,000 or more, more preferably 10,000 or more are used.

The preferred relative amounts of the ionizing radiation-curable resin, the syndiotactic polymethacrylate and the isotactic polymethacrylate are determined according to conditions such as the type of each component and the stereoregularity. Although it is preferable to determine it experimentally as appropriate, the relative amounts of the syndiotactic polymethacrylate and the isotactic polymethacrylate are 80:20
It is preferable that the ratio be in the range of 50 to 50. If the ratio is outside this range, the sol-gel transition hardly occurs. Further, the compounding ratio of the component that undergoes sol-gel transition is preferably in the range of 5 to 80 parts by weight, and more preferably in the range of 10 to 40 parts by weight with respect to 100 parts by weight of the ionizing radiation-curable resin. More preferred. If the compounding ratio of the component that undergoes the sol-gel transition is less than 5 parts by weight, the sol-gel transition may not be performed, and
If the amount is more than the weight part, the viscosity in the sol state becomes too high and handling becomes difficult.

There are various compounds constituting the ionizing radiation-curable resin composition. Oligomers having at least one functional group capable of forming a crosslinked structure by reacting upon irradiation with ionizing radiation in the molecule, and similar functional groups Monomers having one or more groups in the molecule or both are used. Examples of the oligomer or monomer include those which form a radical polymerization type ionizing radiation curable resin such as an unsaturated polyester resin, an acrylic resin, and an ene / thiol resin, or a cationic polymerization type ionizing radiation curable such as an epoxy resin. Forming a conductive resin. Among them, those having an acryloyl group in the molecule are generally used, and an epoxy acrylate-based, urethane acrylate-based, polyester acrylate-based, polyol acrylate-based oligomer or polymer, and a monofunctional, bifunctional or polyfunctional acrylic A mixture with a system monomer is preferably used.

If necessary, various ionizing radiation polymerization initiators may be blended. Examples of the ionizing radiation polymerization initiator include 2,2-dimethoxy-2-phenylacetone, acetophenone, benzophenone, xanthofluorenone, and benzaldehyde. , Anthraquinone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1
-One, 4-oxanthon, camphorquinone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one and the like.

[0026]

The present invention will be specifically described below with reference to examples.

Example 1 An ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition was prepared by the following procedure. Toagosei Co., Ltd. phenol ethylene oxide modified acrylate (Aronix M-101): 90 parts by weight,
Nippon Kayaku Co., Ltd. trimethylolpropane triacrylate (KAYARAD TMPTA): 10 parts by weight, 2-hydroxy-2-methyl-1-manufactured by Ciba Specialty Chemicals Co., Ltd.
Phenyl-propan-1-one (Darocur 1173): After mixing and stirring 5 parts by weight to prepare an ionizing radiation-curable resin composition, as a component that undergoes a sol-gel transition, syndiotactic polymethyl methacrylate (benzoyl peroxide) Of about 98,000 weight average molecular weight by GPC, about 60% of triad syndiotacticity by proton NMR): 10 parts by weight, and isotactic polymethyl methacrylate (t- GPC produced by anionic polymerization using butylmagnesium bromide as an initiator.
0, triad isotacticity of about 85% by proton NMR): 5 parts by weight.

The obtained ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition is heated to 100 ° C. to form a sol, filled in a transparent glass container 3, and gradually cooled to form a gel. Was. Using a photographic negative film having the pattern shown in FIG. 4 as a mask 4 in which the transmittance of ultraviolet rays was repeatedly changed at 0.5 mm intervals, irradiation with ultraviolet light of 20 mW / cm ² was performed by the method of FIG. After irradiating ultraviolet light 2 from the top surface of the mask for 5 seconds, ultrasonic cleaning was performed in ethanol.
After 5 minutes, the uncured gel was dissolved and removed. As a result, it was possible to manufacture an optical article in which the cylindrical lenses shown in FIG. 6 having a lens interval of 0.5 mm and a lens height of 0.2 mm were arranged in parallel.

Example 2 The ionizing radiation-curable resin composition containing a sol-gel transition component used in Example 1 was heated to 100 ° C. to form a sol, and the resin composition was heated to 1 m as shown in FIG.
It was poured into a gap between two polyethylene terephthalate (PET) films 9 provided at intervals of m, and gradually cooled to gel. The same two photographic negative film masks 10 in which the transmittance of ultraviolet light is changed in the plane so that a prism can be formed on the upper and lower surfaces of the film 9 are placed in the direction in which the light and shade patterns are orthogonal to each other on the upper and lower surfaces. Placed. Example
After irradiating the upper and lower masks 10 with ultraviolet light 2 using the same ultraviolet light source as in 1, ultrasonic cleaning was performed in ethanol for 5 minutes.
This was performed for minutes, and the uncured gel was dissolved and removed. As a result, the optical article shown in FIG. 8 in which both prisms were integrated with the prism-shaped molded bodies 11 having a prism interval of 0.7 mm and the parallel prism-shaped molded bodies 11 facing each other at right angles could be produced.

(Example 3) The ionizing radiation-curable resin composition 1 containing a component that undergoes a sol-gel transition used in Example 1 was heated to 100 ° C. to form a sol, and the bottom was formed as shown in FIG. Was filled in a glass transparent container 6 having a curved surface, and gradually cooled to gel. Photographic negative film mask 7 on the underside
After irradiating the lower surface mask with ultraviolet light 2 using the same ultraviolet light source as in Example 1, ultrasonic cleaning was performed in ethanol for 5 minutes to dissolve and remove the uncured gel. As a result, a molded article 8 having the same shape as a contact lens having a diameter of 10 mm was obtained.
was gotten.

[0031]

According to the present invention, an ionizing radiation-curable resin composition containing a phase-change resin component having a function of causing a phase transition from a sol to a "gel which can be differentiated from an ionizing radiation-cured portion" due to some physical change. By irradiating with ionizing radiation through a mask in which the transmittance of ionizing radiation is changed in the plane, high precision can be achieved without cutting optical articles such as fine optical lenses whose thickness changes continuously. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment in which ionizing radiation is irradiated from one direction.

FIG. 2 is a diagram showing an example of an embodiment in which ionizing radiation is irradiated from two directions.

FIG. 3 is a diagram showing an example of a mask for producing a convex lens.

FIG. 4 is a view showing an example of a mask for producing parallel cylindrical lenses.

FIG. 5 is a diagram showing a third embodiment;

FIG. 6 is a diagram showing an optical article in which cylindrical lenses are juxtaposed, manufactured according to Example 1.

FIG. 7 is a diagram showing a second embodiment.

FIG. 8 is a diagram showing an optical article made of prisms orthogonal to each other, manufactured according to Example 2.

FIG. 9 is a view showing an example in which an ionizing radiation-curable resin composition containing no sol-gel transition component is used.

[Explanation of symbols]

1． 1. An ionizing radiation-curable resin composition containing a component that undergoes a sol-gel transition. Ionizing radiation 3. Container 4. Mask 5. Molded body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 5/04 G02B 5/04 A // C08F 2/44 C08F 2/44 C 2/50 2/50 265 / 06 265/06 B29K 101: 10 B29K 101: 10 B29L 11:00 B29L 11:00 F term (reference) 2H042 CA12 CA15 CA17 4F204 AA44 AH74 AH75 EA03 EA04 EB01 EK17 EK18 EK27 4J011 AA05 AC04 BA04 DA02 FA05 FA07 FB01 PA69 PC02 QA03 QA24 QB16 RA03 UA01 VA05 WA07 4J026 AA45 AC36 BA27 BA28 BA50 DB05 DB36 EA06 FA09 GA08 GA10

Claims (2)

[Claims] 1. An ionizing radiation-curable resin composition containing a phase-change resin component having a function of causing a phase transition from a sol to a “gel that can be differentiated from an ionizing radiation-cured portion” by some physical change. On the other hand, a step of imparting some physical change to cause a phase transition to the gel; at least any one of the steps of the ionizing radiation-curable resin composition is performed through a mask whose transmittance changes in the plane of the gel. Irradiating ionizing radiation from a direction to cure the ionizing radiation-curable resin composition; and removing the “gel that can be differentiated from the ionized radiation-cured portion”. A method for manufacturing an optical article, the thickness of which varies according to the ionizing radiation transmittance of the optical article. 2. The step of irradiating ionizing radiation from at least one arbitrary direction to cure the ionizing radiation-curable resin composition, comprising irradiating the ionizing radiation from at least two directions to the ionizing radiation-curable resin composition. The method for producing an optical article according to claim 1, which is a step of curing the resin composition.