JP2006284739A - Manufacturing method of display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a display element, capable of uniformly forming a shape of irregularities, without producing exfoliation defects on a continuous large plastic substrate of a reflecting type liquid crystal display apparatus, an electric field light-emitting display apparatus and an electrophoresis display apparatus or the like. <P>SOLUTION: The manufacturing method of the display element comprises the process steps of (I) applying pre-processing to the plastic substrate 1; (II) sticking together (a) a transferring film, in which a support film 2, an undercoat layer 3, having a number of minute irregularities on a surface and a diffusion reflecting under-layer 4 are stacked sequentially, or (b) a transferring film, in which the support film 2 having a number of minute irregularities on the surface and the diffusion reflecting underlayer 4 are stacked sequentially; (III) irradiating an active energy ray from the transferring film side; (IV) exfoliating the under-coat layer 3 having a number of minute irregularities on its surface or the support film 2, having a number of minute irregularities; and (V) heating the diffusion reflecting underlayer 4 on the plastic substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a display element by a transfer method using a plastic substrate.

  As the display element, a glass substrate has been used as a substrate. As an example, there is a liquid crystal display (hereinafter abbreviated as LCD), which is currently used for display units of mobile phones, watches, calculators, game machines, TVs, electronic notebooks, electronic dictionaries, personal computers, and the like. However, since recent electronic notebooks and personal computers are required to be portable, it is disadvantageous to use heavy and fragile glass as a substrate. In recent years, LCDs using plastic substrates have been developed, and in the future, applications to electronic notebooks and personal computers are expected to expand rapidly. Currently, universities, companies, or national research institutes are actively researching, The results have been announced at academic conferences and exhibitions.

  On the other hand, since a mobile LCD is required to be lightweight, thin, and consume less power, a reflective LCD that reflects external light without using a backlight is used. The reflection type LCD incorporates a reflection plate for efficiently using external light to obtain a bright display.

  The mainstream of reflectors is a substrate with fine irregularities formed on the substrate in order to reflect incident light from all angles and display a bright display to the user. For example, a method by a so-called photolithography method in which a photosensitive resin is applied to a substrate and patterned using a photomask to form an uneven shape, and a metal thin film is formed to form a reflector (Japanese Patent Laid-Open No. Hei 4-243226) A reflector has been proposed. However, since this method uses a spin coating method for resist application, it is difficult to form a concavo-convex shape continuously on, for example, a plastic substrate wound up in a roll shape.

  Also, as a method for continuously forming irregularities on a continuous plastic substrate having a large area, a method using a transfer method has been proposed (see, for example, Patent Documents 2 and 3). However, this method tends to make it difficult to control the peeling failure during transfer to a plastic substrate.

JP-A-4-243226 JP 2000-284106 A JP 2002-32036 A

  Provided is a method for manufacturing a display element which is high in production efficiency, light and difficult to break, and capable of forming a concavo-convex shape uniformly on a continuous large-area plastic substrate for a display element without causing a peeling defect by a transfer method.

  A method of manufacturing a display element with high production efficiency that is light and resistant to cracking, and that can form a concavo-convex shape uniformly on a continuous large-area plastic substrate for display elements without causing peeling defects by the transfer method. In

[1] (a) or (b) A support film 2 having a large number of fine irregularities on the surface, a transfer film in which the diffuse reflection base layer 4 is sequentially laminated, or a support film 2 having a large number of fine irregularities on the surface
The plastic substrate 1 for display element is pretreated, and a transfer film in which a support film 2 on the surface, an undercoat layer 3 having a number of fine irregularities on the surface, and a diffuse reflection base layer 4 are sequentially laminated is laminated and transferred. A display element comprising a step of irradiating active energy rays from the film side and simultaneously removing the support film 2 and the undercoat layer 3 having a number of fine irregularities on the surface by peeling, and heat-curing the diffuse reflective underlayer 4 on the substrate In addition, the present invention provides [2] a glass expansion temperature of the plastic substrate for a display element above 180 ° C. and a linear expansion coefficient of 1 × 10 in a temperature region below the glass transition temperature. It is related with the manufacturing method of the display element as described in said [1] which is below ^-4 / ^degreeC .
The present invention also relates to [3] the method for manufacturing a display element according to [1] or [2] above, wherein the display element plastic substrate is in the form of a sheet or a roll.
The present invention also relates to [4] the method for producing a display element according to any one of [1] to [3] above, wherein the transfer film is in a roll form.
[5] The present invention includes [5] the pretreatment including the step of heating the moisture content of the plastic substrate for display elements to 0.2% by weight or less. 4]. The manufacturing method of the display element in any one of 4).
Further, the present invention provides [6] The above-mentioned [1] to [4], wherein the pretreatment is a chemical surface treatment in which the surface energy of the plastic substrate for display elements is 40 dyn / cm or more. The present invention relates to a method for manufacturing the display element according to any one of the above.
The present invention also relates to [7] the method for manufacturing a display element according to [6], wherein the chemical surface treatment is a corona treatment or a UV treatment.
Further, the present invention provides [8] The display element according to any one of [1] to [7], wherein the bonding is performed by sandwiching between two heating bodies each capable of independently controlling temperature. It relates to a manufacturing method.
In the present invention, [9] the heating temperature of the heating element capable of temperature control is such that the linear expansion coefficient of the plastic substrate for display element is α _A , the linear expansion coefficient of the transfer film is β _B , and the plastic substrate for display element The display according to the above [8], where T _A is the temperature of the heating body in contact with T _A , and T _B is the temperature of the heating body in contact with the transfer film, and T _A > T _B > 70 ° C. if α _A <β _B The present invention relates to a method for manufacturing an element.
The present invention also relates to [10] the method for manufacturing a display element according to [8] or [9] above, wherein the heating body is a roll.
The present invention also relates to [11] The method for producing a display element according to [9] or [10], wherein T _A and T _B are lower than a glass transition temperature of the plastic substrate for display element.
The present invention also relates to [12] the method for producing a display element according to any one of [1] to [11], wherein the active energy ray is ultraviolet light.
Further, the present invention relates to a method of manufacturing a display device according to [13] the irradiation amount of the ultraviolet light is 100~2000mJ / cm ² [12].
Further, the present invention provides [14] Manufacture of the display element according to any one of [1] to [13], wherein the diffuse reflection underlayer is made of a negative resin composition cured by the active energy ray. Regarding the method.
The present invention also relates to [15] the method for manufacturing a display element according to any one of [1] to [14], wherein the peeling is performed at a speed of 3 to 30 m / min.
The present invention also provides [16] any one of the above [1] to [15], wherein the heating temperature of the diffuse reflection underlayer is 150 ° C. or higher and is less than the glass transition temperature of the plastic substrate for display element. The manufacturing method of the display element as described in 1 above.

  The manufacturing method of the display element of the present invention uniformly forms a concavo-convex shape on a plastic substrate for a display element such as a reflection type liquid crystal display device, an electroluminescence display device, an electrophoretic display device, etc. without causing a peeling defect by a transfer method. It is possible to produce a display element with high production efficiency that is light and difficult to break.

As shown in FIG. 1, the manufacturing method of the display element of the present invention includes (I) a step of pre-processing the plastic substrate 1, (II) a surface of the plastic substrate, (a) a support film 2, and a large number of surfaces. A transfer film in which an undercoat layer 3 having fine irregularities and a diffuse reflective underlayer 4 are sequentially laminated, or (b) a support film 2 having numerous fine irregularities on the surface, and a diffuse reflective underlayer 4 are successively laminated. (III) a step of irradiating active energy rays from the transfer film side, (IV) an undercoat layer 3 having a number of fine irregularities on the support film 2 and the surface, or the surface A step of peeling the support film 2 having a large number of fine irregularities, and (V) a step of heating the diffuse reflection underlayer 4 on the plastic substrate.
1 to 6, 1 is a plastic substrate, 2 is a support film, 3 is an undercoat layer, 4 is a diffuse reflective underlayer, 5 is a reflective film, 6 is a heating element, 7 is an active energy ray, 8 is a transfer film, Reference numeral 9 denotes a diffuse reflector.

  First, as shown in FIG. 1A, a transfer film 8 is prepared in which a support film 2, an undercoat layer 3 having a number of fine irregularities on the surface, and a diffuse reflection underlayer 4 are sequentially laminated. Next, as shown in FIG. 1B, the transfer film 8 and the plastic substrate 1 are bonded (laminated). In FIG. 1B, the roll-shaped heating elements 6 are present on both sides, but one may be a flat table and the other may be a roll-shaped heating element. Next, as shown in FIG. 1 (c), the active energy ray 7 is irradiated from the transfer film 8 (support film 2) side to cure the diffuse reflection underlayer, and then as shown in FIG. 1 (d), The support film 2 and the undercoat layer 3 are peeled off from the diffuse reflection underlayer 4 to obtain a laminate in which a diffuse reflection underlayer having fine irregularities formed on a plastic substrate is laminated.

  By heating the laminate in which the diffuse reflection base layer having fine irregularities is laminated on the plastic substrate, the reflective foundation layer 4 can be cured or annealed to maintain the irregular shape. At this time, by using a resin having a property of curing shrinkage or heat deformation as the resin of the reflective underlayer 4, as shown in FIG. 2, the uneven shape can be made gentle by this heating. By smoothing the unevenness of the surface as described above, it is preferable because more reflected light can be condensed on the user. Further, by providing the reflective film 5 on the surface of the diffuse reflection underlayer 4, the diffuse reflection plate 9 can be obtained.

Hereinafter, each process is demonstrated in order.
As already mentioned, the present invention
(I) a step of pre-processing the plastic substrate 1;
(II) On the surface of the plastic substrate, (a) a transfer film in which a support film 2, an undercoat layer 3 having a number of fine irregularities on the surface, and a diffuse reflection underlayer 4 are sequentially laminated, or (b) on the surface A step of laminating a transfer film in which a support film 2 having a large number of fine irregularities and a diffuse reflection underlayer 4 are sequentially laminated;
(III) a step of irradiating active energy rays from the transfer film side;
(IV) a step of peeling the support film 2 and the undercoat layer 3 having many fine irregularities on the surface, or the support film 2 having many fine irregularities on the surface,
(V) a step of heating the diffuse reflection underlayer 4 on the plastic substrate;
It is related with the manufacturing method of the display element characterized by including.

  First, (I) the process of pre-processing the plastic substrate 1 will be described. The plastic substrate used in the present invention is heated to about 150 ° C. when it is thermocompression bonded with an anisotropic conductive film or the like for connection with an external circuit. Further, the liquid crystal is sealed at the final stage of production. Since the heating of the sealant at that time requires 180 ° C., the glass transition temperature of the plastic substrate is preferably a temperature exceeding 180 ° C. More preferably, the temperature is more than 230 ° C, and more preferably 230 ° C. The upper limit is about 250 ° C.

  Examples of the plastic having a glass transition temperature exceeding 180 ° C. include, for example, aromatic polyethersulfone, thermoplastic aromatic polyetherketone, polyetherimide, polyphenylene sulfide, polyarylate, aromatic aramid resin, silicon resin, fluororesin, Examples thereof include cyclic polyolefins and copolymers thereof. Among these, polyethersulfone having a good balance of transparency, heat resistance, processability, and impact resistance is particularly preferable for the production of a liquid crystal display device. If the glass transition temperature is not lower than 180 ° C., resins such as thermoplastic polyester, polyamide, and polycarbonate are preferable in terms of impact resistance, flexibility, and transparency. Moreover, you may mix and use additives, such as a lubricant, a heat stabilizer, a weather stabilizer, a pigment, a dye, and an inorganic filler, as needed.

The linear expansion coefficient of the plastic substrate is preferably 1 × 10 ⁻⁴ / ° C. or less, more preferably 1 × 10 ⁻⁵ / ° C. or less, from the viewpoint of reducing the warpage of the substrate after lamination. More preferably, it is 5 × 10 ⁻⁶ / ° C. or less. The lower limit is, in theory, most preferably a linear expansion coefficient of 0, but 5 × 10 ⁻⁵ / ° C. is the lower limit for commonly available plastics.

  The shape of the plastic substrate is not particularly limited, and may be a sheet shape suitable for a single wafer process using a glass substrate or a roll shape that can be wound up. Further, a sheet having a necessary size may be appropriately cut out from a roll-shaped plastic substrate.

  The thickness of the plastic substrate is preferably 0.05 to 1 mm, more preferably 0.05 to 0.5 mm, and still more preferably 0.05 to 0.1 mm from the viewpoint of maintaining mechanical strength. If it is in the range of this thickness, since it is easy to wind up in roll shape, it is preferable.

  In the method of the present invention, the plastic substrate is preferably pretreated. Examples of the pretreatment here include drying, corona treatment, UV treatment, flame treatment, and sandblast treatment, and these can be used alone or in combination with other pretreatments.

  As said drying, there exists what heat-drys until the moisture content of a plastic substrate will be 0.2 weight% or less, More specifically, for example, a warm air heating furnace, an infrared heating furnace, a hot plate, a heating roll, etc. And a method of exposing to a reduced pressure environment, and the moisture content of the plastic substrate is finally 0.2 wt% or less, preferably 0.1 wt% or less, particularly preferably 0.05. There is a way to reduce it to less than wt%. Among these, from the viewpoint of performing a continuous treatment with the transfer step, a method of reducing the water content of the plastic substrate to 0.2% by weight or less by heating is preferable, and a method using a hot air heating furnace, a hot plate, or a heating roll is particularly preferable. .

  The heating temperature in the drying step must be less than the glass transition temperature of the plastic substrate. Moreover, the heating temperature of 50 degreeC or more is preferable from a viewpoint of reducing a moisture content stably and uniformly. Further, from the viewpoint of efficiently reducing the moisture content in a short time, a heating temperature of 80 ° C. to 150 ° C. is particularly preferable. Note that the heating temperature does not have to be a single temperature, and heat distortion to the plastic substrate can be reduced. Therefore, a facility for increasing or decreasing the temperature stepwise may be used.

  The heating time in the drying step is not particularly limited as long as the moisture content can be 0.2% by weight or less, but a heating time of 10 minutes or less is preferable from the viewpoint of efficiently reducing the moisture content in a short time. When the plastic substrate unwound from the roll is continuously dried, a heating time of 2 minutes or less is particularly preferable from the viewpoint of more efficiently reducing the moisture content in a short time.

  As pretreatment in the production method of the present invention, corona treatment or UV treatment can be preferably used. These pretreatments increase the surface energy by introducing polar functional groups such as hydroxyl, carbonyl, carboxyl or cyano groups into the chemical species that make up the surface of the plastic substrate, and adhere to the diffuse reflective underlayer. Specifically, it can be processed by the method described in the Surface Treatment Technology Handbook. The degree of treatment is selected appropriately depending on the plastic substrate. However, for example, when UV is excessively irradiated, the surface of the plastic substrate deteriorates and tends to deteriorate the adhesion to the diffuse reflection underlayer. The surface energy of the plastic substrate is preferably set to 40 dyn / cm or more by such treatment.

  A gas barrier layer may be laminated on the surface of the plastic substrate used in the present invention. This gas barrier layer is composed of an organic material or an inorganic material. Examples of the organic material include polyvinyl alcohol resin, polyethylene vinyl alcohol copolymer, monochlorotrichloroethylene polymer, vinylidene chloride polymer, polyacrylate, A urethane resin, an epoxy resin, etc. can be mentioned. Examples of the inorganic material include oxides, nitrides, and halides of metals such as Si, Ti, Zr, Al, Ta, Nb, and Sn. In addition, since ITO, which is a transparent conductive material, also has gas barrier properties, in the case of a TFT counter substrate in which transparent electrodes are laminated on one surface, these gas barriers may be provided on only one side. Further, an organic material and an inorganic material may be combined, such as an organic-inorganic nanocomposite or an ultraviolet curable silica precursor composition.

(II) a transfer film 8 in which (a) a support film 2, an undercoat layer 3 having a number of fine irregularities and a diffuse reflection underlayer 4 are sequentially laminated on the surface of the plastic substrate, or (b) a surface A process of laminating a transfer film in which a support film 2 having a large number of fine irregularities and a diffuse reflection base layer 4 are sequentially laminated is laminated on a roll-shaped plastic substrate in a continuous manner. From the viewpoint that a so-called roll-to-roll process can be applied, a roll shape is preferable. However, it is also possible to cut out and use a sheet having a necessary size as appropriate. The transfer film 8 is a transfer film in which a cover film 10 is formed on an adhesive surface to a plastic substrate as shown in FIG. 4 from the viewpoint of portability of the transfer film and storage stability as a roll. Also good. In this case, the cover film is peeled off immediately before use.

  The cover film 10 is preferably chemically and thermally stable and easily peelable from the thin film layer. Specifically, a thin sheet-like material such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol or the like having a high surface smoothness is preferable. What gave the surface the mold release process in order to provide peelability is also contained.

  The transfer film 8 has a structure as shown in FIG. 5 in which a reflection film is formed in advance between the diffuse reflection underlayer and the undercoat layer from the viewpoint of simplifying the steps after the lamination step to the plastic substrate. May be.

  When a reflection film is formed in advance between the diffuse reflection underlayer and the undercoat layer, a separation surface can be set between the undercoat layer and the support film depending on the purpose. For the purpose of laminating the undercoat layer on the substrate, when the reflective film is used as an electrode, if the undercoat layer has a function as an electrical insulating layer, or the undercoat layer serves as a layer for flattening the unevenness of the diffuse reflector If you want to have it, use a photosensitive resin in the undercoat layer to give a role as an etching resist for the reflective film, further color the undercoat layer, to give a role as a partial light shielding layer of the reflective film, etc. There is.

The undercoat layer of the transfer film is a deformable layer laminated on the support film, and the surface is processed by a method such as pressing a prototype having a large number of fine irregularities on the surface of the layer, or performing a sandblast treatment. An example of a method for processing such an undercoat layer is shown in a document “Continued and easy to understand optical disc (Optronics, published in 1990)”.
(B) The transfer film in which the support film 2 having a large number of fine irregularities on the surface and the diffuse reflection base layer 4 are sequentially laminated has a number of fine irregularities on the surface of the support film, and the support film is provided with the support film described above. It plays the role of an undercoat layer. A number of fine irregularities are provided on the surface of the support film, and these fine irregularities are transferred to the diffuse reflection layer. The unevenness on the surface of the support film can be formed by a method such as transferring a prototype having a large number of fine unevenness on the surface against the support film, and sandblasting the support film, as in the case of the undercoat layer. The reflection film can be provided between the support film and the diffuse reflection underlayer. In general, a reflective film is formed on a support film on which irregularities are formed, a diffuse reflective base layer is provided through the reflective film, and the active energy rays are irradiated from the support film side after being bonded to a plastic substrate. If it becomes opaque, it can be irradiated from the plastic substrate side.

  As the support film used in the present invention, a film that is chemically and thermally stable and can be formed into a sheet or a plate can be used. Specifically, polyolefins such as polyethylene and polypropylene, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, cellulose derivatives such as cellulose acetate, nitrocellulose and cellophane, polyamide, polystyrene, polycarbonate, polyimide, polyester, or Metals such as aluminum and copper. Among these, biaxially stretched polyethylene terephthalate having excellent dimensional stability is particularly preferable.

  As the diffuse reflection undercoat layer, a composition containing a deformable organic polymer, an inorganic compound, or a metal can be used. Preferably, the organic layer is coated on the undercoat layer and can be wound into a film. A coalescence composition is used. If necessary, dyes, organic pigments, inorganic pigments, and powders may be used alone or in combination as a composite in the above composition. An energy sensitive resin composition and a thermosetting resin composition can also be used for the diffuse reflection underlayer. The dielectric constant, hardness, refractive index, and spectral transmittance of these diffuse reflection underlayers are not particularly limited. Among such materials, it is preferable to use a material that has good adhesion to a plastic substrate and good releasability from the undercoat layer. For example, acrylic resins, polyolefins such as polyethylene and polypropylene, polyvinyl halides such as polyvinyl chloride and polyvinylidene chloride, cellulose derivatives such as cellulose acetate, nitrocellulose, and cellophane, polyamide, polystyrene, polycarbonate, polyimide, polyester, etc. be able to. In some cases, an energy-sensitive resin composition that can be developed with an alkali or the like can be used so as to leave only the unevenness of the necessary region of the diffuse reflection underlayer and remove the unnecessary portion. In order to improve heat resistance, solvent resistance, and shape stability, a resin composition that can be cured by heat or light after the formation of irregularities can be used. Furthermore, adhesion with a board | substrate can also be improved by adding a coupling agent and an adhesive imparting agent. For the purpose of improving the adhesion, it also includes applying an adhesion-imparting agent to the adhesion surface of the plastic substrate or the diffuse reflection underlayer.

  As the energy-sensitive resin composition that can be developed with alkali or the like, those having an acid value in the range of 20 to 300 and a weight average molecular weight in the range of 1,500 to 200,000 are preferable. For example, styrene derivatives, maleic acid A copolymer comprising a derivative, acrylic acid, acrylic acid derivative, methacrylic acid, methacrylic acid derivative or the like (hereinafter referred to as copolymer (I)) is preferred.

  As the styrene derivative, styrene, α-methylstyrene, m or p-methoxystyrene, p-methylstyrene, p-hydroxystyrene, 3-hydroxymethyl-4hydroxy-styrene and the like can be used.

  Examples of the maleic acid derivative include maleic anhydride, maleic acid, monomethyl maleate, monoethyl maleate, mono-n-propyl maleate, mono-iso-propyl maleate, n-butyl maleate, mono-iso maleate -Butyl, mono-tert-butyl maleate and the like can be used.

  As the alkyl methacrylate, methyl methacrylate, t-butyl methacrylate, hydroxyethyl methacrylate and the like can be used.

  In order to increase the crosslinking density of the copolymer (I), the acid anhydride group or carboxyl group in the copolymer (I) can be modified with a compound having a reactive double bond.

  Examples of the compound having a reactive double bond include allyl alcohol, 2-blanc-1-olfurfuryl alcohol, oleyl alcohol, cinnamyl alcohol, 2-hydroxyethyl acrylate, hydroxyethyl methacrylate, N-methylol acrylic. Examples thereof include unsaturated alcohols such as amide, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate, itaconic acid monoalkyl monoglycidyl ester, and the like. In this case, it is necessary that the carboxyl group necessary for alkali development remains in the copolymer.

  These copolymers can be synthesized according to the methods described in JP-B-47-25470, JP-B-48-85679, JP-B-5-21572, and the like.

  The film thickness of the diffuse reflection undercoat layer is preferably in the range of 0.1 μm to 50 μm from the viewpoint of better reproducing the unevenness of the undercoat layer. If it is too thin, the reflective underlayer cannot fill the unevenness of the undercoat layer. On the other hand, if it is too thick, the amount of deformation tends to increase when the reflective underlayer is heated.

  The undercoat layer used in the present invention is preferably harder than the diffuse reflection base layer from the viewpoint of stably maintaining the shape of the diffuse reflection base layer. For example, polyolefins such as polyethylene and polypropylene, ethylene and vinyl acetate, ethylene and acrylate esters, ethylene copolymers such as ethylene and vinyl alcohol, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, vinyl chloride and vinyl alcohol Copolymers, polyvinylidene chloride, polystyrene, styrene copolymers such as styrene and (meth) acrylate, polyvinyltoluene, vinyltoluene copolymers such as vinyltoluene and (meth) acrylate, poly ( Use at least one organic polymer selected from (meth) acrylic acid esters, copolymers of (meth) acrylic acid esters such as butyl (meth) acrylate and vinyl acetate, synthetic rubbers, cellulose derivatives, etc. be able to.

  In addition, a photoinitiator, a monomer having an ethylenic double bond, or the like can be added in advance as necessary for curing after forming the irregularities.

  As the coating method of the undercoat layer and the diffuse reflection undercoat layer used in the present invention, a roll coating method, a spin coating method, a spray coating method, a dip coating method, a curtain flow coating method, a wire bar coating method, a gravure coating method, an air knife coating method , Inkjet coating method, doctor blade coating method, screen coating method, die coating method, cap coating method and the like. A thin film layer or undercoat layer composition is applied onto the support film by the method described above.

  In the bonding (laminating) step of the present invention, the diffuse reflection base layer on the transfer film may be adhered to the plastic substrate, and the material of the laminating roll and the laminating pressure are not particularly limited.

  As a device for laminating (laminating) a transfer film used in the present invention, a roll that feeds a plastic substrate while pressing the transfer film against the plastic substrate by sandwiching the plastic substrate between rolls that can be heated and pressurized, rotating the roll It is preferable to use a laminator. A schematic view of using such an apparatus is shown in FIG. In FIG. 6, a roll-shaped transfer film 8 is disposed on a roll-shaped plastic substrate 1 with the diffuse reflection base layer facing down, laminated while being sandwiched between two heating bodies 6, and wound into a roll. Before winding, a step of irradiating active energy rays, which will be described later, may be included.

The temperature of the laminate is not particularly limited, but is preferably less than the glass transition temperature of the plastic substrate used. In particular, from the viewpoint of uniformity and apparatus heat resistance related to the material of the laminate roll, 80 ° C. to 150 ° C. is preferable. Furthermore, the temperature of the plastic substrate side and the transfer film side is not necessarily the same from the viewpoint of stable production while maintaining the plastic substrate dry. Preferably, the substrate side temperature is set higher than the transfer film side temperature. The laminating step is preferably performed by sandwiching the two heating elements, each of which can be controlled independently, and the heating temperature of the heating element capable of controlling the temperature determines the linear expansion coefficient of the plastic substrate as α. _a, linear expansion coefficient beta _B of the transfer _film, when the temperature of the heating body in contact with the plastic substrate T _a, the temperature of the heating body in contact with the transfer film was T _B, α _{a <β B} if T _a> T It is preferable that _B > 70 ° C. Further, it is preferable that T _A and T _B is less than the glass transition temperature of the plastic substrate.

The speed of laminating is not particularly limited, but from the viewpoint of laminate productivity, 0.5 m / min to 10 m / min is preferable. In addition, when providing continuity with the drying process, the drying equipment can be reduced in size and continuity. In order to measure, 1 m / min to 5 m / min is particularly preferable.
When exposed to the atmosphere from the drying process to the laminating process, moisture absorption of the plastic substrate occurs, so the aforementioned gas / water vapor barrier is formed to suppress moisture absorption or reach a moisture content of 0.2% by weight. Laminate quickly before. The time until lamination is not particularly limited because it depends on the temperature and humidity of the exposed atmosphere and the material of the plastic substrate.

(III) a step of irradiating active energy rays from the transfer film side; and (IV) a step of peeling off the undercoat layer 3 having a number of fine irregularities on the support film 2 and the surface. When a mold resin composition is used, exposure is performed by an exposure machine in order to impart stability of the shape, and the photosensitive portion is cured.

Examples of the exposure apparatus that can be applied to the present invention include a carbon arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, an excimer laser, and an electron beam. This exposure apparatus may be a parallel exposure machine for pattern formation such as pixels and BM. However, in the example of the present invention, it is only necessary to cure the unevenness formed in advance. For this purpose, the photosensitive resin is cured. What is necessary is just to give the light quantity more than exposure amount. In the present invention, it is preferable that the active energy ray is ultraviolet light and the irradiation amount of ultraviolet light is 100 to 2000 mJ / cm ² . Therefore, it is possible to use a UV irradiation device (low pressure mercury lamp) that uses scattered light that can be incorporated into a line that is generally used as a substrate cleaning device. By using these apparatuses, it can be manufactured at a lower cost than the method using a photomask, and the tolerance for the exposure amount is larger than when using a photomask. There is no problem even if the photosensitive type is a positive type. The exposure is preferably performed before peeling off the support film and the undercoat layer, but can also be performed after peeling off. In the present invention, peeling is preferably performed at a speed of 3 to 30 m / min.

(V) Step of heating the diffuse reflection base layer 4 on the plastic substrate The temperature of the heat curing of the present invention is preferably less than the glass transition temperature of the plastic substrate from the viewpoint of avoiding thermal deformation of the plastic substrate. Moreover, since heating at a minimum of 150 ° C. is necessary to sufficiently cure the diffuse reflection underlayer, the heating temperature is preferably 150 ° C. or higher and lower than the glass transition temperature. The heating temperature does not need to be a single temperature, and equipment that raises or lowers the temperature stepwise may be used from the viewpoint of reducing thermal strain at the interface between the plastic substrate and the diffuse reflection underlayer.

  The heating time of the heat curing is not particularly limited as long as the diffuse reflection underlayer is sufficiently cured, but a heating time of 30 minutes is preferable in order to sufficiently transmit heat to the deep part of the diffuse reflection underlayer and promote curing.

  A reflection film can be formed on the diffuse reflection underlayer after heat curing of the present invention to form a diffuse reflection plate.

For the reflective film, a material may be appropriately selected depending on the wavelength region to be reflected. For example, in a reflective LCD display device, a metal having a high reflectance in a visible light wavelength region of 300 nm to 800 nm, such as aluminum, gold, silver, etc. Are formed by vacuum vapor deposition or sputtering. Moreover, you may laminate | stack a reflection increase film | membrane (it describes in the optical outline 2 (Junpei Takiuchi, Asakura Shoten, 1976 issue)) by said method. The thickness of the reflective film is preferably 0.01 μm to 50 μm. In addition, the reflective film may be patterned only by a photolithography method, a mask vapor deposition method, or the like.
The following examples illustrate the invention.

Example 1
Using a polyethylene terephthalate with a thickness of 50 μm sandblasted for the support film, the following thin film layer forming solution is applied and dried on this film to a film thickness of 6 μm with a comma coater to form the diffuse reflective underlayer 4, and cover A polyethylene film was coated as the film 10 and wound up into a roll to obtain a transfer film as shown in FIG.
Thin film layer forming solution: Styrene, methyl methacrylate, ethyl acrylate, acrylic acid, glycidyl methacrylate copolymer resin was used as a polymer (polymer A).
The molecular weight is about 35000 and the acid value is 110.
Parts are parts by weight (the same applies hereinafter).
(Polymer) Polymer A 70 parts (monomer) Pentaerythritol tetraacrylate 30 parts (photoinitiator) Irgacure 369 (Ciba Specialty Chemicals)
2.2 parts
N, N-tetraethyl-4,4′-diaminobenzophenone
2.2 parts (solvent) Propylene glycol monomethyl ether 492 parts (polymerization inhibitor) p-methoxyphenol 0.1 part (surfactant) perfluoroalkyl alkoxylate 0.01 part In Example 1, the support film was sandblasted By forming fine irregularities and transferring the irregularities to the diffuse reflection underlayer, forming an undercoat layer on the support film, and pressing the master with a large number of fine irregularities on the surface of the undercoat layer for transfer You can also.

(Example 2)
Three polyethersulfone substrates (PES substrate A) having a glass transition temperature of 220 ° C. and a linear expansion coefficient of 5.5 × 10 ⁻⁵ / ° C. below the glass transition temperature are cut into squares with a side of 290 mm, Heating was performed at 100 ° C., 120 ° C., and 140 ° C. for 20 minutes in a wind heating furnace to obtain corresponding PES substrate samples B-100, B-120, and B-140. The moisture content of PES substrate A was 1.4% by weight, whereas B-100 was 1.0% by weight, B-120 was 0.2% by weight, and B-140 was 0.15% by weight. Met. A PES substrate sample C was obtained by subjecting the PES substrate A cut out separately to UV treatment at 153 mJ / square cm. Further, the PES substrate A was subjected to a corona treatment with an output of 0.29 kW from a height of 10 mm to obtain a PES substrate sample D. As a result of measuring the surface energy with a wetting index measuring pen (manufactured by VETAPHONE), the PES substrate A was 35 dyn / cm, whereas the PES substrate sample C was 40 dyn / cm, and the PES substrate sample D was 44 dyn / cm. there were.

(Example 3)
A roll laminator (HLM1500, Hitachi Chemical Technoplant) is placed on PES substrate samples A, B-100, B-120, B-140, C and D so that the transfer film from which the cover film has been peeled is in contact with the diffuse reflective underlayer. Manufactured by the same company), the temperature of the roll in contact with the PES substrate is 150 ° C., the temperature of the roll in contact with the transfer film is 90 ° C., the pressure is 5 kg / square cm, and the speed is 1 m / min. Corresponding members A, B-100, B-120, B-140, C and D in which a diffuse reflection underlayer and a polyethylene terephthalate film (PET film) were sequentially laminated were obtained. This is irradiated with 500 mJ / sq. Cm of i-line that the diffuse reflection underlayer reacts with a large-sized manual exposure machine (MAP1200, manufactured by Dainippon Screen), and then the PET film is peeled off, so that members B-120, B-140, C The unevenness that was sandblasted was uniformly transferred onto the diffuse reflection underlayer of A and D, and the uneven shape was excellent in light diffusibility. Although it was magnified 100 times with a microscope, no bubbles were generated in any of the members B-120, B-140, C, and D. On the other hand, in the members A and B-100, 10 μm-sized bubbles were confirmed at an average density of 60 / mm and 44 / mm, respectively, and peeling of the diffuse reflection underlayer starting from these bubbles was visually confirmed. It was done. When the members B-120, B-140, C and D were put into a warm air heating furnace and heated at 170 ° C. for 30 minutes, there was no change in appearance.

Example 4
The transfer film from which the cover film is peeled off is placed on the PES substrate C described in Example 1 so that the diffuse reflection base layer is in contact, and the roll temperature in contact with the PES substrate is 90 ° C. using the roll laminator. When laminating at a roll temperature of 70 ° C., a pressure of 5 kg / square cm, and a speed of 1 m / min, a corresponding member C2 in which a PES substrate C, a diffuse reflection underlayer, and a polyethylene terephthalate film (PET film) are sequentially laminated Obtained. When the PET film is peeled off after irradiating the i-line with 500 mJ / square cm with a large manual exposure machine, the sandblasted unevenness is uniformly transferred onto the diffuse reflection base layer of the member C2, and the light diffusibility It was excellent in uneven shape. Although the image was magnified 100 times with a microscope, no bubbles were generated. Moreover, when member C2 was put into a warm air heating furnace and heated at 170 ° C. for 30 minutes, there was no change in appearance.

(Example 5)
The transfer film from which the cover film is peeled off is placed on the PES substrate C described in Example 1 so that the diffuse reflection base layer is in contact, and the roll temperature in contact with the PES substrate is 150 ° C. using the roll laminator. When laminating at a roll temperature of 90 ° C., a pressure of 5 kg / square cm, and a speed of 1 m / min, a corresponding member C3 in which a PES substrate C, a diffuse reflection underlayer, and a polyethylene terephthalate film (PET film) are sequentially laminated. Obtained. The member C3 was cut into four pieces with a cutter knife, and irradiated with different i doses so as to be sequentially 100, 500, 1000 and 2000 mJ / square cm with a large manual exposure machine. When the PET film was peeled off, the sandblasted irregularities were uniformly transferred onto the diffuse reflection underlayer of the member C3, and the irregularities were excellent in light diffusibility. Although the image was magnified 100 times with a microscope, no bubbles were generated. Moreover, when the member C3 was put into a warm air heating furnace and heated at 170 ° C. for 30 minutes, the appearance did not change.

(Example 6)
The transfer film from which the cover film is peeled off is placed on the PES substrate C described in Example 1 so that the diffuse reflection base layer is in contact, and the roll temperature in contact with the PES substrate is 150 ° C. using the roll laminator. When the roll temperature is 90 ° C., the pressure is 5 kg / square cm, and the speed is 1 m / min, the corresponding member C4 in which the PES substrate C, the diffuse reflection underlayer, and the polyethylene terephthalate film (PET film) are sequentially laminated. Obtained. This was irradiated with 500 mJ / square cm of i-line using a large manual exposure machine, then cut into three pieces, and the PET film was peeled off at a rate of 3, 15 and 30 m / min. The processed unevenness was uniformly transferred, and the uneven shape was excellent in light diffusibility. Although the image was magnified 100 times with a microscope, no bubbles were generated. Moreover, when these members C4 were put into a warm air heating furnace and heated at 170 ° C. for 30 minutes, none of the appearances changed.

(Example 7)
The transfer film from which the cover film is peeled off is placed on the PES substrate C described in Example 1 so that the diffuse reflection base layer is in contact, and the roll temperature in contact with the PES substrate is 150 ° C. using the roll laminator. When laminating at a roll temperature of 90 ° C., a pressure of 5 kg / square cm, and a speed of 1 m / min, a corresponding member C5 in which a PES substrate C, a diffuse reflection underlayer, and a polyethylene terephthalate film (PET film) are sequentially laminated Obtained. When the PET film is peeled off after irradiating the i-line with 500 mJ / square cm using a large-sized manual exposure machine, the sandblasted unevenness is uniformly transferred onto the diffuse reflection base layer of the member C5, and the light diffusibility It was excellent in uneven shape. Although the image was magnified 100 times with a microscope, no bubbles were generated. Further, when the member C5 was cut into three pieces and sequentially heated in a hot air heating furnace at 150 ° C., 170 ° C., and 200 ° C. for 30 minutes, none of the appearances changed.

  According to the above results, the display element manufacturing method of the present invention makes it possible to manufacture a display element with high production efficiency that is light and difficult to break.

  In addition, the display element manufacturing method of the present invention is not a conventional single wafer process but a method suitable for manufacturing an LCD using a plastic substrate performed by a roll-to-roll process, which is advantageous in terms of mass productivity and cost. .

1 schematically shows the production method of the present invention. It is a cross-sectional schematic diagram which shows the gentle uneven | corrugated shape of the reflective base layer on a plastic substrate. It is a cross-sectional schematic diagram which shows the diffuse reflection board manufactured with the manufacturing method of this invention. It is a cross-sectional schematic diagram which shows the transfer film which provided the cover film in the reflective base layer side. It is a cross-sectional schematic diagram which shows the transfer film which provided the reflecting film between the undercoat and the reflective base layer. It is the schematic at the time of performing the manufacturing method of this invention by roll to roll.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic substrate 2 Support film 3 Undercoat layer 4 Diffuse reflective base layer 5 Reflective film 6 Heating body 7 Active energy ray 8 Transfer film 9 Diffuse reflective plate 10 Cover film

Claims (16)

(I) Step of pre-processing the plastic substrate 1, (II) (a) a support film 2, an undercoat layer 3 having a number of fine irregularities on the surface, and a diffuse reflection underlayer 4 are sequentially formed on the surface of the plastic substrate. (B) a step of laminating a transfer film formed by laminating a transfer film formed by sequentially laminating a support film 2 having a number of fine irregularities on the surface and a diffuse reflection base layer 4; A step of irradiating active energy rays, (IV) a step of peeling off the support film 2 and the undercoat layer 3 having a large number of fine irregularities on the surface, or a support film 2 having a large number of fine irregularities on the surface, (V ) A method for producing a display element, comprising the step of heating the diffuse reflection underlayer 4 on the plastic substrate. 2. The method for manufacturing a display element according to claim 1, wherein the glass transition temperature of the plastic substrate is a temperature exceeding 180 ° C., and a linear expansion coefficient in a temperature region below the glass transition temperature is 1 × 10 ⁻⁴ / ° C. or less. . The display element manufacturing method according to claim 1 or 2, wherein the display element plastic substrate has a sheet shape or a roll shape. The method of manufacturing a display element according to any one of claims 1 to 3, wherein the transfer film has a roll shape. 5. The display element according to claim 1, wherein the pretreatment includes a step of heating the moisture content of the plastic substrate for a display element to 0.2 wt% or less. Production method. 5. The method for manufacturing a display element according to claim 1, wherein the pretreatment includes a chemical surface treatment for setting the surface energy of the plastic substrate for display elements to 40 dyn / cm or more. The method for manufacturing a display element according to claim 6, wherein the chemical surface treatment is corona treatment or UV treatment. The method for manufacturing a display element according to claim 1, wherein the bonding is performed by sandwiching between two heating bodies capable of independently controlling the temperature. The heating temperature of the heating body capable of temperature control is such that the linear expansion coefficient of the display element plastic substrate is α _A , the linear expansion coefficient of the transfer film is β _B , and the temperature of the heating body in contact with the display element plastic substrate is T _A The manufacturing method of a display element according to claim 8, wherein when _{A A} <β _B , T _A > T _B > 70 ° C., where T _B is the temperature of the heating body in contact with the transfer film. The method for manufacturing a display element according to claim 8 or 9, wherein the heating body is a roll. Method of manufacturing a display device according to the T _A and T _B is claim 9 or claim 10 which is below the glass transition temperature of the plastic substrate for a display device. The method for manufacturing a display element according to claim 1, wherein the active energy ray is ultraviolet light. The method for manufacturing a display element according to claim 12, wherein an irradiation amount of the ultraviolet ray is 100 to 2000 mJ / cm ² . The method for manufacturing a display element according to claim 1, wherein the diffuse reflection underlayer is made of a negative resin composition cured by the active energy ray. The method for manufacturing a display element according to claim 1, wherein the peeling is performed at a speed of 3 to 30 m / min. The method for manufacturing a display element according to any one of claims 1 to 15, wherein the heating temperature of the diffuse reflection underlayer is 150 ° C or higher and is lower than the glass transition temperature of the plastic substrate for display element.

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