JP6989089B2 - Method for manufacturing a film having an uneven shape - Google Patents

Description

The present invention relates to a method for producing a film having an uneven shape.

A film having an uneven pattern on its surface is used in various fields. For example, in the field of adhesive sheets, an adhesive processed sheet having an adhesive layer in which a large number of independent small convex portions are arranged in a scattered pattern, and an adhesive having a groove formed between a plurality of convex portions and adjacent convex portions. Adhesive sheets with layers are known.

Further, as a decorative material used for interior decoration materials, furniture, cabinets, etc., in recent years, there is a demand for a novel aesthetic effect having a high-class and complicated surface decoration and a three-dimensional effect. As a method for producing such a decorative material, for example, an embossing process and a printing process are combined to give an embossed uneven pattern that is synchronized and matched with the printed pattern applied to the surface of the base material to obtain a decorative material having a three-dimensional effect. The method of manufacturing is known.

On the other hand, in a display such as a liquid crystal display device, light is incident on the screen from the outside, and this light is reflected (called glare or glare), which may make it difficult to see the displayed image. Therefore, various antiglare treatments are applied to the surface of the display.

As a method for producing a decorative material or an uneven film used for antiglare treatment as described above, for example, in Patent Document 1, a coating liquid is applied to form a coating layer, and then a predetermined shape having a temperature distribution on a heated surface is provided. A method is disclosed in which a heating plate provided with a pattern is brought into contact with the back surface side of a base material to dry the coating layer, and an uneven pattern is formed on the surface thereof to form an uneven pattern. .. Further, in Patent Document 2, a cooling plate provided with a concavo-convex pattern having a predetermined shape at a predetermined distance from the surface of a wet coating film containing a solvent provided on the base material is provided with the concavo-convex pattern. Disclosed is a method of forming an uneven pattern by arranging the coating film so as to face the coating film surface and arranging them substantially in parallel, and evaporating the solvent in the coating film.

Japanese Unexamined Patent Publication No. 2007-203247 Japanese Unexamined Patent Publication No. 2009-226330

However, the techniques described in Patent Documents 1 and 2 have a problem that when the film and the pattern plate come into contact with each other, the uneven edges of the pattern plate cause scratches or marks on the film. In addition, dust easily enters the recesses of the pattern plate during the manufacturing process, and the recesses have a small diameter of only a few millimeters. Therefore, if the ratio of dust to one recess increases, the thermal conductivity of the recesses will be affected. Therefore, there is also a problem that the heat conductivity distribution in the plane becomes non-uniform. Furthermore, in the technique described in Patent Document 2, since it is essential to use a cooling plate, if the solid content of the coating liquid is low, the evaporated solvent will condense and fall onto the coating film. There is a problem that it will be stored.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a film having an uneven shape that prevents scratches and uneven marks of a mold (pattern plate) from occurring on the film. be.

As a result of diligent studies by the present inventor, it has been found that the above-mentioned problems can be solved by using a flat plate having a thermal conductivity difference made of a specific material, and the present invention has been achieved.
That is, the present invention is a method for manufacturing a film having an uneven shape.
The first step of preparing a flat plate having a smooth surface and having a thermal conductivity distribution on the surface,
A second step of arranging a coating film containing a liquid medium and a film material on the surface of a flat plate, and
A third step of forming a film having an uneven shape by heating the flat plate and removing the liquid medium in the coating film arranged on the surface of the flat plate.
It is a method of manufacturing a film having a concavo-convex shape.

In the method for producing a film having an uneven shape of the present invention, the thermal conductivity distribution is caused by at least two kinds of materials.
The difference in thermal conductivity between at least two types of materials is preferably 10 W / m · K or more.

Further, the thermal conductivity distribution may be formed by periodically arranging at least two kinds of materials.

Of the at least two types of materials, at least one is preferably a metal and the other material is preferably an organic material.

In the second step, after the coating film is provided on the base material, the coating film may be arranged on the surface by bringing the base material into contact with the surface of the flat plate.

In the third step, the cooling plate may be brought close to the surface on the opposite side of the flat plate of the coating film.

The thickness of the base material is preferably 1 μm or more and 200 μm or less.

The material of the film is preferably at least one of a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, and an active energy ray-polymerizable compound.

According to the manufacturing method of the present invention, it is possible to provide a film having an uneven shape without scratches and uneven marks.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the method for manufacturing a film having an uneven shape according to the present invention. FIG. 2 is a schematic plan view showing an example of a flat plate used in the method for producing a film having an uneven shape according to the present invention. FIG. 3 is a schematic cross-sectional view showing an embodiment in which a coating film is provided on a base material. FIG. 4 is a schematic cross-sectional view showing an embodiment when a cooling plate is used.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
[First step]
The first step is a step of preparing a flat plate 10 having a smooth surface 10c and a thermal conductivity distribution on the surface 10c.
(Plate)
As shown in FIG. 1A, the flat plate 10 has a smooth surface 10c and a thermal conductivity distribution on the surface 10c. The flat plate 10 does not necessarily show only a flat shape, and may be processed into a roll shape as long as the surface is smooth and has a thermal conductivity distribution.
Here, "smooth" means that the maximum height Rt is 500 nm or less. The maximum height Rt is preferably 1 nm or more and 200 nm or less, and more preferably 3 nm or more and 20 nm or less. The maximum height Rt is measured by the method described in the examples.
As shown in FIG. 2, the flat plate 10 can be manufactured, for example, by forming a hole 11 in a metal plate having a high thermal conductivity and then filling the hole 11 with a material having a low thermal conductivity. Further, after filling with a material having a low thermal conductivity, the surface 10c of the flat plate 10 can be smoothed by polishing by a method such as buffing, belt polishing, electrolytic polishing, or chemical mechanical polishing. In this way, as shown in FIG. 1A, the thermal conductivity is formed by periodically arranging a region 10a having a high thermal conductivity and a region 10b having a low thermal conductivity on the surface 10c of the flat plate 10. A distribution is formed.

The thickness of the flat plate 10 is preferably 100 to 2000 μm. There is no particular limitation on the shape of the hole 11 in the drilling process, and the hole can be drilled into various shapes such as a circle, an ellipse, an ellipse, and a polygonal shape. Will be. In this case, the diameter of the hole 11 is usually about 0.3 to 4.0 mm, preferably 0.5 to 3.5 mm. The pitch between the holes (the distance between the center points of the adjacent holes 11 is usually 0.5 to 6.0 mm, preferably 0.7 to 5.0 mm. Further, the adjacent holes 11 and the holes 11 are adjacent to each other. The shortest distance between the holes is usually about 0.2 to 6.0 mm, preferably 0.5 to 5.0 mm. For example, the pitch x (feed pitch) between holes as shown in FIG. 2 and the holes. A hole pattern or the like having an interval y (type pitch) of 11 rows and arranging in a 60 ° staggered arrangement is suitable.
Examples of the method for forming the hole 11 include drilling, punching, etching, and laser machining.

Of the materials that give rise to the thermal conductivity distribution, it is preferable that at least one kind is a metal and the other material is an organic material. As the metal, aluminum (thermal conductivity: 230 W / m · K), stainless steel plate (for example, thermal conductivity of SUS304: 16.1 W / m · K) and the like having a thermal conductivity of 15 W / m · K or more. Can be used. As the organic material, an acrylic resin (thermal conductivity: 0.3 W / m · K), a polystyrene resin (heat conductivity: 0.12 W / m · K) and the like can be used. Further, a heat conductive grease obtained by adding inorganic particles such as silica to an organic material may be used.

The difference in thermal conductivity between at least two types of materials for producing a thermal conductivity distribution is preferably 10 W / m · K or more. In FIG. 2, the thermal conductivity distribution formed by two kinds of materials having different thermal conductivitys is shown, but the thermal conductivity distribution may be formed by arranging three or more kinds of materials. When arranging three or more kinds of materials, "the difference in thermal conductivity between at least two kinds of materials is 10 W / m · K or more" means that the difference in thermal conductivity is 10 W / K regardless of the combination of the materials. It means that it is m · K or more.

[Second step]
The second step is a step of arranging the coating film 20 containing the liquid medium and the material of the film on the surface 10c of the flat plate 10 as shown in FIGS. 1A and 1B.
(Formation of coating film)
As a method for forming the coating film 20, conventionally known methods such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, and a gravure coating method can be used. In this case, the thickness of the coating film 20 is usually 3 to 200 μm, preferably 5 to 150 μm, and more preferably 10 to 100 μm after drying.

(Membrane material)
As the material of the coating film 20 used in the method for producing a film having an uneven shape of the present invention, at least one of a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin and an active energy ray-polymerizable compound is used as a basic component. It may further contain a cross-linking agent, a tackifier, an antioxidant, an ultraviolet absorber, a coupling agent, a flame retardant, a colorant, a light stabilizer, a leveling agent, an antifoaming agent and the like, if necessary.

(Thermoplastic resin, thermoplastic elastomer)
Examples of the thermoplastic resin include acrylic resin, silicone resin, polyester resin, polyvinyl chloride resin, polyolefin resin, polyamide resin, polycarbonate resin and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.
Examples of the thermoplastic elastomer (including rubber-like elastic material) include styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. , Fluoroplastic elastomer, natural rubber, conjugated diene synthetic rubber and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

(Thermosetting resin)
Examples of the thermosetting resin include an acrylate-based polymer having a carbon-carbon double bond and a glycidyl group, an unsaturated polyester, an epoxy resin, a phenol resin, a urea resin, and a melamine resin. These may be used alone or in combination of two or more.
As these thermosetting resins, a curing agent is usually used. Examples of the curing agent include organic peroxides, azo compounds, polyisocyanate compounds, polyamines, acid anhydrides, imidazoles, dicyandiamides, Lewis acids, formaldehyde, etc., and the types of thermosetting resins to be used include. It is appropriately selected accordingly.

(Active energy ray-polymerizable compound)
Examples of the active energy ray-polymerizable compound (a polymer compound having an energy quantum in an electromagnetic wave or a charged particle beam, that is, a polymerizable compound that is crosslinked and cured by irradiation with an ultraviolet ray or an electron beam) are, for example, active energy ray-polymerized. Sexual prepolymers and / or active energy ray polymerizable monomers can be mentioned. The active energy ray-polymerizable prepolymer includes a radical polymerization type and a cationic polymerization type, and examples of the radical polymerization type active energy ray-polymerizable prepolymer include polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, and polyol acrylate-based. And so on.
On the other hand, an epoxy resin is usually used as the cationically polymerized active energy ray-polymerizable prepolymer. Examples of the epoxy resin include compounds obtained by epoxidizing polyhydric phenols such as bisphenol resin and novolak resin with epichlorohydrin and the like, and compounds obtained by oxidizing linear olefin compounds and cyclic olefin compounds with peroxides and the like. And so on.
Further, examples of the active energy ray-polymerizable monomer include bifunctional or higher functional acrylates.

(Photopolymerization initiator)
A photopolymerization initiator is added to the active energy ray-polymerizable compound, if desired. The photopolymerization initiator includes, for example, benzoins, benzophenones, and acetophenones for radical polymerization type photopolymerizable prepolymers and photopolymerizable monomers among active energy ray-polymerizable prepolymers and monomers. Examples thereof include α-hydroxyketones, α-aminoketones, α-diketones, α-diketone dialkylacetals, anthraquinones, thioxanthones and the like.
Examples of the photopolymerization initiator for the cationically polymerizable photopolymerizable prepolymer include oniums such as aromatic sulfonium ion, aromatic oxosulfonium ion, and aromatic iodonium ion, and tetrafluoroborate, hexafluorophosphate, and hexafluoro. Examples thereof include compounds composed of anions such as antimonate and hexafluoroarsenate. When an electron beam is used as the active energy ray, the photopolymerization initiator may not be used.

(Type of coating liquid)
In the present invention, various kinds of coating liquids can be used depending on the intended use, for example, a coating liquid for adhesives, a coating liquid for forming an optical hard coat, a coating liquid for forming a gloss adjusting layer, and the like. Can be used.
For example, when a coating liquid for an adhesive is used, an uneven fine pattern is formed on the surface of the adhesive layer, so that when it is attached to an adherend, an air flow path is created and air stays. Is less likely to occur, and the stickability is improved.
When a coating liquid for forming a gloss adjusting layer is used, an uneven fine pattern is formed on the film surface, and the diffused reflection of light exerts a gloss adjusting effect. Therefore, it should be used for decorative sheets and wallpaper. Can be done.
When the coating liquid for forming an optical hard coat is used, it can be used as an antiglare hard coat layer or the like because an uneven fine pattern is formed on the film surface.

(Liquid medium of coating liquid, viscosity)
The coating liquid used in the present invention contains a liquid medium, and the liquid medium is not particularly limited. Depending on the type of resin component and polymerizable compound contained in the coating liquid, water and various organic solvents can be selected. It can be selected as appropriate. Examples of the organic solvent include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as methanol, ethanol, propanol and butanol, and acetone. , Methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone and other ketones, ethyl acetate, butyl acetate and other esters, ethyl cellosolve and other cellosolve solvents, propylene glycol monomethyl ether and other glycol ether solvents and the like.
The concentration of the coating liquid is not particularly limited, but the viscosity at a temperature of 23 ° C. is about 10 to 3500 mPa · s, preferably 50 to 3000 mPa · s, from the viewpoint that the effect of the present invention is preferably exhibited. Is preferably a concentration of 100 to 2500 mPa · s.

(Base material)
As shown in FIGS. 3A and 3B, the coating film 20 may be arranged after forming the coating film 20 on the base material 22 on the surface 10c of the flat plate 10. After that, by heating the flat plate 10 with the heating plate 30, an uneven shape can be formed on the surface 21c of the film 21.
The base material 22 is not particularly limited, and examples thereof include a paper base material, a plastic film, a plastic sheet, a metal foil, a metal sheet, and the like, and can be appropriately selected depending on the intended use. These base materials may be used alone, and may be arbitrary, such as a composite of papers or materials of the same type such as plastic films or plastic sheets, or a composite of paper and different materials such as plastic films or plastic sheets. It is also possible to use a laminated sheet in which the materials of the above are combined.
Paper base materials include, for example, thin leaf paper, kraft paper, coated paper, art paper, sulfate paper, glassin paper, parchment paper, paraffin paper, Japanese paper, titanium paper, linter paper, paperboard, base paper for gypsum board, and reinforcement between papers in advance. Examples thereof include resin-impregnated paper impregnated with resin for the purpose of the above, vinyl wallpaper raw fabric having a vinyl chloride resin layer on the surface of the paper, and the like.

Examples of plastic films and plastic sheets include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene films, polypropylene films, cellophane, diacetyl cellulose films, triacetyl cellulose films, acetyl cellulose butyrate films, and polyvinyl chlorides. Film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyether ether ketone film, polyether sulfone film, polyetherimide film, Examples thereof include a polyimide film, a fluororesin film, a polyamide film, an acrylic resin film, a norbornene-based resin film, a cycloolefin resin film, and a sheet of these resins.
As the metal foil or the metal sheet, those made of a material such as aluminum, iron, stainless steel, or copper are used.
In the present invention, the thickness of the base material is not particularly limited, and a wide range, for example, a range of about 20 μm to 10 mm is appropriately selected depending on the intended use. More preferably, it is 1 μm or more and 200 μm or less.

(Surface treatment of plastic base material)
When a plastic film or a plastic sheet is used as the base material 22, one side or both sides thereof is preferably surface-treated by an oxidation method, an unevenness method, or the like for the purpose of improving the adhesion to the layer provided on the surface thereof. Can be done. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like, and examples of the unevenness method include a sandblast method and a solvent. The processing method and the like can be mentioned. These surface treatment methods are appropriately selected depending on the type of the base material, but in general, the corona discharge treatment method is preferably used from the viewpoints of effectiveness and operability. It is also possible to apply a primer treatment.

[Third step]
In the third step, as shown in FIG. 1 (c), the flat plate 10 is heated by a heating plate 30 or the like to remove the liquid medium in the coating film 20 arranged on the surface 10c of the flat plate 10. This is a step of forming a film 21 having an uneven shape on the surface 21c.
The mechanism by which the uneven shape of the film is formed by heating the flat plate 10 is as follows. When the coating film 20 containing the liquid medium is heated, the temperature of the coating film 20 in the region in contact with the region 10a having high thermal conductivity is lowered by the heat of vaporization, and the surface tension due to the temperature decrease is increased. By rising, a convex shape is formed in the heated portion. In the present invention, due to the thermal conductivity distribution of the flat plate 10, the coating film 20 is formed by a portion of the coating film 20 in contact with the region 10a having a high thermal conductivity and a portion of the coating film 20 in contact with the region 10a having a high thermal conductivity. There is a difference in the drying rate. Due to this difference in drying speed, a gradient is generated in the surface tension generated in the coating film 20, and a film forming an uneven shape can be formed on the surface.

(Heating plate)
The method for heating the flat plate 10 is not particularly limited, but as shown in FIGS. 1B and 1C, a method in which the heating plate 30 is brought into contact with the back surface 10d of the flat plate 10 is preferable. The shape of the heating plate 30 is not particularly limited, and may be a flat plate or may have an uneven shape.
As the heating plate 30, in addition to a flat plate of a heat conductive metal, a plate obtained by subjecting a plurality of holes to a heat conductive metal plate can be used. The heat conductive metal plate is not particularly limited, and for example, an aluminum plate or a stainless steel plate is used.
The temperature of the heating plate 30 is preferably 50 to 200 ° C. If the temperature is too low, the temperature difference between the heated portion and the non-heated portion is small, and surface tension flow is unlikely to occur. If the temperature is too high, there is a concern about thermal deformation of the base material during heating.

The time from the formation of the coating film 20 to the contact of the coating film 20 (or the base material 22) with the heating plate 30 varies depending on the type and film thickness of the solvent in the coating liquid, but is usually 0 to 30. It is about a second. If it exceeds 30 seconds, the surface of the coating layer may be solidified and a predetermined pattern shape may not be obtained.
In addition, the temperature of the coated layer surface immediately after coating may drop due to evaporation of the solvent, and water vapor in the atmosphere may condense on the coated layer surface. Therefore, the temperature drop on the coated layer surface is measured in advance with a non-contact thermometer or the like. However, it is preferable to take measures such as controlling the temperature and humidity of the atmosphere. Further, the time for contacting the coating film 20 with the heating plate 30 is preferably 15 to 500 seconds.
When a continuous coating device is used, the flat plate 10 having a thermal conductivity distribution may be processed into a roll shape, and the roll-shaped flat plate 10 may be heated by a known heating device.

As shown in FIGS. 3A and 3B, the coating film 20 is formed by providing the coating film 20 on the base material 22 and then bringing the base material 22 into contact with the surface 10c of the flat plate 10. , The coating film 20 may be arranged on the surface 10c. Then, as shown in FIG. 3C, by heating the flat plate 10 with the heating plate 30, a film 21 having an uneven shape is formed on the surface 21c.

(Cooling plate)
In the third step, as shown in FIG. 4A, the cooling plate 40 may be brought close to the surface 20a of the coating film 20 opposite to the flat plate 10. Then, by heating the heating plate 30, the uneven shape can be formed as shown in FIG. 4 (b).
Here, "proximity" means that the point at which the cooling plate 40 protrudes most from the surface 20a of the coating film 20 is 0.1 mm or more and 5 mm or less. More preferably, it is 0.5 to 1.5 mm.
The cooling plate 40 preferably has an uneven shape corresponding to the heat conduction distribution of the flat plate 10. When the cooling plate 40 is brought close to the surface 20a of the coating film 20, as shown in FIG. 4, the convex portion 40a of the cooling plate 40 is made to correspond to the region 10a having high thermal conductivity of the flat plate 10. Since the surface temperature of the surface 20a of the coating film 20 corresponding to the portion in contact with the region 10a having high thermal conductivity of the heating plate 30 is lowered by the heat of vaporization, the surface temperature difference of the coating film is more effectively provided. As a result, the uneven shape formed becomes clearer.

As the cooling plate 40, for example, one made by processing a heat conductive metal plate can be used. The heat conductive metal plate is not particularly limited, and for example, an aluminum plate or a stainless steel plate can be used. The thickness of the cooling plate 40 is preferably 0.1 to 2 mm. The thickness of the cooling plate 40 provided with the uneven shape indicates the distance between the back surface and the bottom surface inside the recess.

The shape of the convex portion 40a is not particularly limited, and examples thereof include a columnar shape, an elliptical columnar shape, an oblong columnar shape, and a polygonal columnar shape. Further, the convex portions 40a may be arranged geometrically, may be arranged in a pattern, or may be arranged randomly. The height of the convex portion 40a (distance from the bottom surface of the concave portion to the tip of the convex portion) is usually about 0.05 to 100 mm, preferably 1 to 5 mm, and in the case of a columnar shape, the cross-sectional diameter thereof is usually 0. It is about 3 to 4.0 mm, preferably 0.5 to 3.5 mm, and the pitch between the convex portions (distance between the center points of the adjacent convex portions 40a) is usually 0.5 to 6.0 mm. It is preferably 0.7 to 5.0 mm. The shortest distance between the adjacent convex portions 40a is usually about 0.2 to 6.0 mm, preferably 0.5 to 5.0 mm.

The surface temperature of the cooling plate 40 is preferably 5 to 20 ° C, more preferably 10 to 15 ° C from the viewpoint of effectiveness. In this case, the difference in surface temperature between the cooling plate 40 and the heating plate 30 is preferably 20 to 70 ° C, more preferably 40 to 60 ° C, from the viewpoint of forming the uneven shape corresponding to the unevenness of the cooling plate 40.

The time from the formation of the coating film until the cooling plate 40 is brought close to the surface 20a of the coating film 20 is usually about 0 to 30 seconds, although it depends on the type and film thickness of the liquid medium in the coating film. be. If it exceeds 30 seconds, the surface of the coating layer may be solidified and a predetermined pattern shape may not be obtained.

By disposing a cooling plate 40 having a predetermined uneven shape near the surface of the coating film 20 and evaporating the liquid medium in the coating film 20, the uneven shape corresponding to the uneven shape of the cooling plate 40. However, the following is presumed as the mechanism formed on the surface of the coating film.
When there is a temperature difference on the free surface of the fluid, a difference in surface tension occurs, and the fluid surface is pulled toward the side with the larger surface tension (low temperature side), causing a flow, so-called Marangoni convection.
By arranging the cooling plate 40 having a predetermined uneven shape in the vicinity of the surface of the coating film, a temperature difference is generated on the surface of the coating film corresponding to the shape of the cooling plate 40. As a result, it is presumed that a driving force that tends to flow from a place where the surface temperature is high to a place where the surface temperature is low is generated, and a portion having a high surface temperature forms a concave portion and a portion having a low surface temperature forms a convex portion.

(Formation of energy-curing coating film)
In this way, a film having an uneven shape corresponding to the difference in thermal conductivity of the flat plate 10 can be obtained. In the present invention, further energy is applied to the coating film 20 as needed to obtain the coating film. 20 can be cured. For example, when a coating liquid containing an active photocurable polymerizable compound is used, after forming a dry coating film having an uneven shape on the surface as described above, active rays such as ultraviolet rays and electron beams are formed on the dry coating film. Is irradiated to form a cured resin film. On the surface of this cured resin film, the uneven shape provided on the surface of the dry coating film remains as it is.
When a coating liquid containing a thermosetting resin is used, heat energy is applied to the dry coating film or the thermosetting coating film having an uneven shape on the surface as described above. However, it can be completely heat-cured. On the surface of the completely thermosetting resin film, the uneven shape provided on the surface of the dry coating film or the thermosetting coating film remains as it is.

As described above, according to the present invention, it is possible to form an uneven shape having a predetermined shape without making scratches or uneven marks on the film.
The film having an uneven shape on the surface produced in this way is useful as, for example, an adhesive layer, an optical hard coat layer, a gloss adjusting layer in a decorative material, a three-dimensional effect imparting layer, and the like. In particular, according to the production method of the present invention, it is possible to obtain a film having an uneven shape capable of producing a complicated surface decoration by using a flat plate 10 having a thermal conductivity distribution composed of three or more kinds of materials. can.

Hereinafter, the present invention will be described in more detail with reference to examples. The scope of the present invention is not limited to the specific examples shown below.

[Example 1]
(First step)
A flat plate having a thermal conductivity distribution was produced as follows. First, a hole of 500 μmφ is punched into an aluminum plate with a thickness of 0.5 mm and an area of 25 cm ² (5 cm × 5 cm) on one side, and a hole with a feed pitch of 1 mm and a mold pitch of 0.5 mm is arranged in a 60 ° staggered pattern. Formed. Next, all the pores were filled with an acrylic resin (manufactured by JSR Co., Ltd., trade name "Opstar Z7530" (UV curable acrylic monomer)) as a material having low thermal conductivity. Finally, the surface (both sides) was polished and flattened by 400 count buffing. The maximum height Rt of the polished surface measured using a non-contact three-dimensional optical interferometry surface roughness meter (manufactured by Veeco Japan, trade name: Wyko NT1100) was 15 nm.
(Second step)
Acrylic adhesive (manufactured by Nippon Carbide Industry Co., Ltd., trade name "Nisetsu PE-121", solid content 20 wt%) on the peeled surface of the peeling film (Lintec Corporation SP-PET 50) using polyethylene terephthalate as the base material. Was applied to form a coating film having a thickness of 80 μm on the film.
(Third step)
Next, a flat plate and a coating film with a base material are sequentially arranged on a heating plate heated to 70 ° C. (Kitazato Science Micro Heat Plate MP-1000H), and the sample is heated for 1 minute through the flat plate to make unevenness. A film having a shape was obtained.
No scratches were observed on the back surface of the substrate, which was in contact with the flat plate.

[Example 2]
The same procedure as in Example 1 was carried out except that a flat plate in which all the holes were filled with thermal grease (manufactured by Shin-Etsu Chemical Co., Ltd., thermal grease trade name “WW-7868”) was used. Similar to Example 1, no scratches were observed on the back surface of the base material which was in contact with the flat plate. The maximum height Rt of the polished surface of the flat plate was 15 nm.

[Example 3]
The same procedure as in Example 1 was carried out except that a stainless steel plate (SUS304) was used instead of the aluminum plate. The maximum height Rt of the polished surface of the flat plate was 19 nm.

[Example 4]
When a heat conductive grease (manufactured by Shin-Etsu Chemical Co., Ltd., thermal grease trade name "WW-7868") was used instead of the acrylic resin, the same procedure as in Example 3 was carried out. The maximum height Rt of the polished surface of the flat plate was 19 nm.

[Comparative Example 1]
Similar to Example 1 except that a flat aluminum plate (which does not form holes in the aluminum plate used in Example 1) was used instead of the flat plate having the above thermal conductivity distribution and heated with a hot plate. did. The surface of the film was smooth, and no scratches were observed on the back surface of the base material that was in contact with the aluminum plate.

[Comparative Example 2]
The same procedure as in Comparative Example 1 was carried out except that a stainless steel plate (SUS304) (which did not form holes in the stainless steel plate used in Example 3) was used instead of the aluminum plate.

[Comparative Example 3]
Instead of the flat plate of Example 1, a concavo-convex pattern plate in which holes of 500 μmφ were processed into a 60 ° zigzag pattern was used. As a result of heating the coating film with the heating plate via the uneven plate, unevenness was formed on the film surface. On the other hand, the back surface of the base material, which was in contact with the uneven pattern plate, had an arcuate scratch of about 500 μmφ. The maximum height on the side where the coating film with a base material of the flat plate is arranged has an Rt of 500 μm.

[Comparative Example 4]
The same procedure as in Comparative Example 3 was carried out except that a stainless steel plate (SUS304) was used instead of the aluminum plate. The maximum height Rt on the side where the coating film with a base material of the flat plate is arranged is 500 μm.

The evaluation of the membranes obtained in the above Examples and Comparative Examples was performed by the following method.
(Evaluation of film surface unevenness)
After the third step, the unevenness of the film surface was observed with an optical microscope (Keyence Co., Ltd., Digital Microscope VHX5000). The observation magnification was 250 times, and observation was performed at arbitrary 25 points in an area of 25 mm × 25 mm on the surface of the obtained film. The observation area at one point of the observation position was 1600 μm × 1200 μm.

(Evaluation of scratches on the back surface of the base material)
After the third step, the back surface of the substrate (the surface opposite to the surface provided with the coating film) was observed with an optical microscope (Keyence Co., Ltd., Digital Microscope VHX5000). The observation magnification was 250 times, and observation was performed at arbitrary 25 points in an area of 25 mm × 25 mm on the back surface of the base material. The observation area at one point of the observation position was 1600 μm × 1200 μm.

(Evaluation of height difference of unevenness)
The height difference of the unevenness of the produced film was measured by the following method.
Using a non-contact three-dimensional optical interferometry surface roughness meter (manufactured by Veeco Japan, trade name: Wyko NT1100), the maximum height Rt based on ANSI / ASME B46.1 was measured, and this was used to measure the unevenness of the film. The height difference was set. The maximum height Rt indicates the sum of the highest peak and the deepest valley in the reference length of the roughness curve.

(Evaluation of thermal conductivity)
Thermal conductivity was measured using "ai-Phase Mobile 1μ" from iPhase Co., Ltd. For the thermal conductivity of air, refer to p.350 of "Introduction to Chemical Engineering" of Sangyo Tosho Co., Ltd.

Table 2 shows the evaluation results of Examples and Comparative Examples.

As shown in Table 2, in Examples 1 to 4 using the production method of the present invention, an uneven shape having a height difference of several μm was formed on the film surface, and scratches and marks on the heating plate were formed on the back surface of the substrate. Was not seen.
In Example 2 in which the thermal conductive grease was used as the material having a small thermal conductivity, the height difference of the unevenness was smaller than in Example 1 in which the acrylic resin was used as the material having a small thermal conductivity. From Examples 1 and 3, there was no difference in the height difference of the unevenness of the film between the aluminum plate and SUS304, which are the materials constituting the region having high thermal conductivity of the flat plate. This is because the amount of evaporation is limited, so even if the thermal conductivity increases and the drying rate increases, it is considered that the temperature drop due to the heat of vaporization has leveled off.

10 Flat plate 10a Area with high thermal conductivity 10b Area with low thermal conductivity 10c (flat plate) front surface 10d Flat plate back surface 11 holes 20 Coating film 20a (coating film) surface 21 film 21c (film) surface 22 units Material 30 Heating plate 40 Cooling plate 40a Convex part

Claims (8)

It is a method for manufacturing a film having an uneven shape.
The first step of preparing a flat plate having a smooth surface and having a thermal conductivity distribution on the surface, and
The second step of arranging the coating film containing the liquid medium and the material of the film on the surface of the flat plate, and the second step.
A third step of forming a film having the uneven shape by heating the flat plate and removing the liquid medium in the coating film arranged on the surface of the flat plate.
A method for producing a film having an uneven shape. The thermal conductivity distribution is caused by at least two materials.
The method for producing a film having an uneven shape according to claim 1, wherein the thermal conductivity difference between the at least two kinds of materials is 10 W / m · K or more. The method for producing a film having an uneven shape according to claim 1 or 2, wherein the thermal conductivity distribution is such that at least two kinds of materials are periodically arranged. The method for producing a film having an uneven shape according to any one of claims 1 to 3, wherein at least one of the at least two kinds of materials is a metal and the other material is an organic material. In the second step, after the coating film is provided on the substrate, the coating film is arranged on the surface by bringing the substrate into contact with the surface of the flat plate, according to claims 1 to 4. The method for producing a film having an uneven shape according to any one of the above items. The method for producing a film having an uneven shape according to any one of claims 1 to 5, wherein in the third step, a cooling plate is brought close to the surface of the coating film on the side opposite to the flat plate. The method for producing a film having an uneven shape according to claim 5 , wherein the thickness of the base material is 1 μm or more and 200 μm or less. The production of a film having an uneven shape according to any one of claims 1 to 7, wherein the material of the film is at least one of a thermoplastic resin, a thermoplastic elastomer, a thermosetting resin, and an active energy ray-polymerizable compound. Method.

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