JP2020003448A - Stimulus-responsive reversible deformation structure and method for manufacturing the same - Google Patents

Abstract

To provide a stimulus-responsive reversible deformation structure which can change the amount of curling intentionally according to the moisture of the surroundings and can thus give an excellent visual effect, and a method for manufacturing the stimulus-responsive reversible deformation structure.SOLUTION: The present invention relates to a stimulus-responsive reversible deformation structure including: a base material 12; and a matrix 11 on at least one side of the base material. The matrix is made of resin having the characteristics of adsorbing and desorbing water, and the change of the volume in association with the adsorption and desorption of water by the matrix changes the amount of curling of the structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stimulus-responsive reversible deformable structure that reversibly deforms in volume with the adsorption and desorption of moisture and a method for producing the same. More specifically, the matrix has a substrate film and a matrix on at least one side thereof, and the matrix is composed of a resin having a property of adsorbing and desorbing moisture, and the matrix is formed by a volume change accompanying the adsorption and desorption of moisture of the matrix. The present invention relates to a stimuli-responsive reversible deformable structure characterized by changing the curl of a film.

  In recent years, various functional films have been used in various fields such as electronic products such as flat panel displays, agricultural products, and building materials such as wallpaper.

  In any field, the occurrence of curl (warpage) in the functional film causes problems when using the functional film alone, and also impairs the adhesiveness of the functional film to the object to be bonded. For that reason, it is required to reduce curl as a functional film alone. Further, it is required that such curls do not change with respect to disturbance factors such as temperature and humidity.

For example, as in Patent Literature 1, there is a functional film in which curling is suppressed by laminating a hard coat layer and a curl suppressing layer.
Further, as in Patent Document 2, there is known a means for suppressing curling using a combination of two types of acrylate compounds.

  Thus, it has been demanded that the original function of the functional film is not hindered by taking measures to suppress curling.

Japanese Patent No. 6097836 Japanese Patent No. 4500522

  On the other hand, the present invention is based on a different idea from the above, and captures, as a function, a change in the amount of curl with respect to a change in the use environment. In other words, a volume change caused by adsorbing and desorbing moisture of the matrix formed on the surface of the base material applies a stress to one side of the base material, thereby intentionally changing the curl amount and, at the same time, improving the visual quality. Provided are a stimuli-responsive reversible deformable structure capable of giving an effect and a method for producing the same.

In order to solve the above-mentioned problems, a stimuli-responsive reversible deformation structure according to the present invention is:
A substrate and a structure having a matrix on at least one side thereof,
The matrix is made of a resin having a property of adsorbing and desorbing moisture,
The curl amount of the structure is changed by a volume change caused by the adsorption and desorption of moisture in the matrix.

  In addition, the resin according to the present invention is preferably a polymer or a copolymer of a curable resin material.

  Further, the curable resin material according to the present invention preferably has ionizing radiation curability or thermosetting property.

  The change in volume of the matrix due to the adsorption and desorption of moisture in the matrix may be controlled by any one of the matrix composition, the degree of curing, the crosslink density, and the degree of polymerization.

  The stimulus-responsive reversible deformable structure according to the present invention is characterized in that at least the matrix or the substrate surface is printed with ink.

Further, the stimulus-responsive reversible deformation structure according to the present invention,
A plurality of cut portions having a cut-like hole formed therein that penetrates the matrix and the base material are arranged, and the curl amount of the cut portions changes due to a volume change accompanying adsorption and desorption of moisture in the matrix. It is characterized by.

Further, in the method for producing a stimuli-responsive reversible deformable structure of the present invention,
A coating liquid preparation step of preparing a coating liquid containing a curable resin material,
An application step of applying the coating liquid on a substrate,
A heat treatment step of heat treating the coating liquid to form a coating film,
Irradiating the coating film with ionizing radiation to cure and form a cured film, an ionizing radiation irradiation step of forming a matrix composed of the cured film supported on the base material,
At least.

Further, in the method for producing a stimuli-responsive reversible deformable structure of the present invention,
Forming a printing pattern on the matrix or the substrate,
In the step of performing a notch-shaped hole processing in the matrix,
It is characterized by further comprising one or both steps.

  INDUSTRIAL APPLICABILITY The present invention can use a reversible volume change accompanying the adsorption and desorption of moisture of a matrix formed on a substrate, and can give a reversible change in curl amount to the substrate. Utilizing this, a print pattern is provided in a portion where the curl amount changes, causing a visual change with respect to the adsorption or desorption of moisture, furthermore, a humidity sensor using the curl amount, a front and back of the base material It is possible to provide useful effects such as a change in the amount of transmitted air.

FIG. 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformation structure 1 according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the stimulus-responsive reversible deformable structure 1 according to the embodiment of the present invention in a state where moisture is eliminated. FIG. 3 is a schematic cross-sectional view of the stimulus-responsive reversible deformation structure 1 according to the embodiment of the present invention in a state where moisture is adsorbed. FIG. 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformation structure 2 according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the stimulus-responsive reversible deformable structure 2 according to the embodiment of the present invention in a state where moisture is adsorbed and desorbed. FIG. 2 is a schematic cross-sectional view (top) of the stimuli-responsive reversible deformable structure 3 according to the embodiment of the present invention (top) and a schematic view from the matrix surface side (bottom). FIG. 3 is a schematic cross-sectional view (top) and a schematic view from the matrix surface side (bottom) of the stimulus-responsive reversible deformable structure 3 according to the embodiment of the present invention in a state where moisture is eliminated. FIG. 2 is a schematic diagram of the stimulus-responsive reversible deformation structure 3 according to the embodiment of the present invention, as viewed from the matrix surface side. FIG. 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformable structure 4 according to an embodiment of the present invention, and the state of desorption of water (right). FIG. 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformable structure 4 according to an embodiment of the present invention, and the state of desorption of water (right). FIG. 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformable structure 4 according to an embodiment of the present invention, and the state of desorption of water (right). 1 is a schematic cross-sectional view of a stimuli-responsive reversible deformation structure 4 according to an embodiment of the present invention. 4 is a photographic image showing a state before and after a curl change of the stimulus-responsive reversible deformable structure according to the embodiment of the present invention. 5 is a photographic image before and after a change in a moire pattern observed in the stimuli-responsive reversible deformable structure according to the embodiment of the present invention.

  Hereinafter, the stimuli-responsive reversible deformation structure of the present invention will be described in detail with reference to the drawings.

(Stimuli-responsive reversible deformable structure 1)
FIG. 1 is a schematic sectional view showing an example of a stimulus-responsive reversible deformable structure 1 having a film-like structure according to an embodiment of the present invention. As shown in FIG. 1, the present structure has a matrix 11 made of a material whose volume changes due to the adsorption and desorption of moisture, and a base film 12. FIG. 1 shows a state where the matrix 11 is not particularly changed.
FIG. 2 is a schematic cross-sectional view showing a state of the matrix 11 changed with desorption of water, and FIG. 3 is a schematic cross-sectional view of a state changed with the adsorption of water on the matrix 11.
In the description of the present invention, a film is described as an example of a substrate, but the substrate is not limited to a film. For example, in addition to a film, a sheet, a thin film, a foil, and the like can be given.

  When the matrix 11 desorbs water from the state shown in FIG. 1 (FIG. 2), the volume of the matrix 11 decreases, but since the matrix 11 and the base film 12 are in close contact with each other, the stress 13 applied to the matrix is reduced. It is applied to the film 12 (the direction of the stress is indicated by an arrow) and curls toward the matrix side. Conversely, when the matrix 11 absorbs water from the state shown in FIG. 1 (FIG. 3), the volume of the matrix 11 increases, but since the matrix 11 and the base film 12 are in close contact, the stress 13 applied to the matrix is It joins the material film 12 and curls toward the base film.

In preparing the initial state without curls shown in FIG. 1, it is possible to change the stimulus responsiveness to water by adjusting the state in which the matrix adsorbs or desorbs water.
For example, when the initial state without curls shown in FIG. 1 is prepared in a state where almost all of the water is desorbed, curls as shown in FIG. Adsorption causes a stronger curl, and the state of FIG. 2 does not occur.
Conversely, when the initial state without curls shown in FIG. 2 is made in a state where water is contained up to the limit, the state shown in FIG. 3 does not occur, and when left in an environment of 23 ° C. and 50% RH, the curls shown in FIG. And further desorption of water leads to stronger curl.
For example, when the initial state without curling shown in FIG. 1 is manufactured at 23 ° C. and 50% RH, the state can be adjusted so that the state shown in FIG. 2 is obtained at 25% RH and the state shown in FIG.

  The material constituting the matrix 11 is not particularly limited as long as it exhibits a volume change with the adsorption and desorption of moisture. Examples of the material that adsorbs moisture include carboxyl groups, aldehyde groups, and hydroxyl groups which are hydrophilic groups. It is preferably a hydrophilic polymer-based material having an amino group, an amide group, a sulfone group, or the like, a mixed material thereof, or a composite material containing particles, fillers, and the like.

  Examples of the hydrophilic polymer-based material include polyacrylic acid, polymaleic acid, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylpyridine, polyacrylamide, polyethylene oxide, and polyvinyl sulfone. Further, in these material systems, a mixture composed of two or more kinds incorporated in a main chain or a side chain may be used. Specific examples include a copolymer of polyacrylic acid and polyvinyl alcohol, and a copolymer of polyacrylic acid and polymaleic acid.

  Further, as a mixed material system that changes in volume due to adsorption and desorption of moisture, a gel material or the like is also preferably used. Specifically, a double network gel in which two types of hydrophilic polymer chains form an interpenetrating polymer network to increase strength, and a nanocomposite gel in which clay, a clay compound, acts as a physical crosslinking point Is mentioned.

  The hydrophilic polymer material and the gel material preferably include a curable resin material formed of an organic monomer, oligomer, or polymer having ionizing radiation curability or thermosetting property.

  The ionizing radiation-curable organic monomers, oligomers, and polymers refer to substances that are cured through a cross-linking reaction by irradiation with active energy rays such as ultraviolet rays and electron beams. By using a curable material, it is possible to form not only a flat film but also various structures such as patterning, an uneven structure and a spherical structure. Further, since the crosslinking density can be controlled by changing the curing conditions, it is also possible to control the rate of volume change accompanying the adsorption and desorption of moisture.

  Specific examples of ionizing radiation-curable monomers and oligomers used for hydrophilic polymer materials and gel materials include acrylamide, N-methylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide, and N, N-dimethyl. Aminopropylacrylamide, N, N-dimethylaminopropylacrylamide various quaternary salts, acryloylmorpholine, N, N-dimethylaminoethylacrylate various quaternary salts, acrylic acid, various alkyl acrylates, methacrylic acid, various alkyl methacrylates, 2-hydroxy Ethyl methacrylate, glycerol monomethacrylate, N-vinylpyrrolidone, acrylonitrile, styrene, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopenty Glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane , 2-hydroxy-1-acryloxy-3-methacryloxypropane, 2,2-bis [4- (acryloxypolypropoxy) phenyl] propane, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol Dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4- (methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxyethoxydiethoxy) phenyl ] Propane, 2,2-bis [4- (methacryloxyethoxypolyethoxy) phenyl] propane, trimethylolpropanetrimethacrylate, tetramethylolmethanetrimethacrylate, trimethylolpropanetriacrylate, tetramethylolmethanetriacrylate, tetramethylolmethanetetra Acrylate, dipentaerythritol hexaacrylate, N, N'-methylenebisacrylamide, N, N'-methylenebismethacrylamide, diethylene glycol diallyl ether, divinylbenzene And the like.

  As the thermosetting resin according to the present embodiment, a resin composition containing an unsaturated polyester resin or an epoxy resin as a main component is preferable. More specifically, an unsaturated polyester resin is a resin composition containing an unsaturated polyester resin, a reactive diluent having a hydroxyl group and a carbon-carbon double bond, and a polymerization initiator as essential components, The resin is preferably a resin composition containing, as essential components, a liquid bisphenol-type epoxy resin, a phenol resin curing agent having a hydroxyl group and a carbon-carbon double bond, and a curing accelerator.

  A crosslinking agent may be appropriately added to the hydrophilic polymer material or the gel material according to the present embodiment. As the crosslinking agent, a compound having two or more polymerizable functional groups can be used. Specifically, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin , N, N'-methylenebisacrylamide, N, N-methylene-bis-N-vinylacetamide, N, N-butylene-bis-N-vinylacetamide, tolylene diisocyanate, hexamethylene diisocyanate, allylated starch, allylation Cellulose, diallyl phthalate, tetraallyloxyethane, pentaerythritol triallyl ether, trimethylolpropane triallyl ether, diethylene glycol diallyl ether, triallyl trimellitate, etc. .

Further, a filler may be appropriately added to the hydrophilic polymer material or the gel material according to the present embodiment. Examples of the shape of the filler include a spherical shape, a particle shape, a needle shape, a fibrous shape, a plate shape, a scaly shape, a rod shape, an amorphous shape, and the like, and those having a hydrophilic surface are compatible with monomers and resins. Is preferred.
For example, in the case of a particulate form, metal oxide fine particles or metal fine particles that have been subjected to a hydrophilic treatment, zeolite, polymer fine particles, and the like can be used. Further, in the case of a plate shape, a water-swellable layered clay compound such as saponite, stevennite, hectorite, montmorillonite, lucentite, and somasif is exemplified. In the case of a fibrous form, cellulose nanofiber, carbon nanotubes subjected to hydrophilization treatment, glass filler and the like can be mentioned.

For the hydrophilic polymer material or the gel material according to the embodiment of the present invention, a polymerization initiator can be appropriately selected depending on the polymerization mode.
Specific examples of the polymerization initiator include hydrogen peroxide, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, and azo-based initiators such as 2,2′-azobis (2-amidinopropane). Dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride, 2,2'-azobis {2-methyl-N- [1,1, -bis (hydroxymethyl)- 2-hydroxyethyl] propionamide {, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, 4,4'-azobis (4-cyanovaleric acid), 2,2 '-Azobisisobutyronitrile, 2,2'-azobis (2,4'-dimethylvaleronitrile), benzophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxycyclohexyl Phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphonic oxide, 1- [4- (2-hydroxyethoxy) -phenyl] -2- Compounds which generate radicals by ultraviolet light such as hydroxy-2-methyl-1-propan-1-one, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino -2-hydroxypropoxy) -3,4-dimethyl-9H-thioxanthone-9-one mesochloride, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1, bis ( Clopentadienyl) -bis (2,6-difluoro-3- (pyr-1-yl) titanium, 1,3-di (t-butylperoxycarbonyl) benzene and 3,3 ′, 4,4′-tetra Compounds that generate radicals by light having a wavelength of 360 nm or more, such as a substance obtained by mixing a thiopyrylium salt, merocyanine, quinoline, and stilquinoline-based dye with peroxyester such as-(t-butylperoxycarbonyl) benzophenone, and the like can be given. Hydrogen peroxide or persulfate can be used as a redox initiator by combining a reducing substance such as sulfite or L-ascorbic acid or an amine salt.

The base film 12 according to the present invention, PE film, polypropylene film, polyethylene terephthalate film, nylon film, polyamide film, polyurethane film, acrylic film, vinyl chloride film, ethylene vinyl acetate copolymer film, triacetyl cellulose film, Films such as paper, metal foil, and wood such as timber can be used, and any material can be used.
Since it is necessary that the curl amount changes depending on the volume change amount due to the adsorption and desorption of moisture of the matrix 11, a film or a sheet is preferable. Even if these are laminated, the film surface may be coated, printed, or shaped.

  When the volume of the base film 12 changes due to the adsorption and desorption of moisture, the change in curl is reduced or not generated. Therefore, the base film 12 preferably has a small volume change due to the adsorption and desorption of water. . More preferably, the volume change is preferably 1% or less.

  The thickness of the base film 12 is not particularly limited, but is preferably 1 μm or more and 100 μm or less. In the case of 1 μm or less, the strength of the stimuli-responsive reversible deformable structure cannot be ensured, and in the case of 100 μm or more, due to the rigidity of the base film 12, even if there is a volume change due to moisture adsorption and desorption of the matrix 11, This is because curling hardly occurs.

  In order to obtain the effect of the present invention, the matrix 11 and the base film 12 need to be tightly adhered. A method of performing a hydrophilic treatment such as an ozone treatment, a corona treatment, or a plasma treatment on the surface of the base film 12 on which the matrix 11 is formed can be used. Further, the matrix 11 and the base film 12 may be fixed with an adhesive or an adhesive.

(Stimuli-responsive reversible deformation structure 2)
FIG. 4 is a schematic cross-sectional view showing an example of the stimulus-responsive reversible deformable structure 2 having a film-like structure according to the embodiment of the present invention. A substrate film 22 and matrices 21 and 23 made of a material whose volume changes due to adsorption and desorption of moisture are provided on both surfaces thereof.

When such a structure is adopted, the curl direction can be changed by the difference in moisture adsorption and desorption of the matrix on both surfaces of the stimuli-responsive reversible deformable structure.
For example, when the compositions, curing degrees, crosslink densities, polymerization degrees, and film thicknesses of the matrices 21 and 23 are the same and the volume change rates due to the adsorption and desorption of moisture are the same, the stimuli-responsive reversible deformable structure If the amount of moisture adsorption is relatively larger on the 23 side than on the 21 side, the stimulus-responsive reversible deformable structure can be curled so that the 23 side is convex as shown in FIG. Conversely, when the amount of water desorption is relatively smaller on the 21 side than on the 23 side via the stimuli-responsive reversible deformable structure, the stimuli-responsive reversible deformable structure is curled such that the 21 side is convex. (Not shown).
It is also possible to change the direction and amount of curl due to moisture adsorption and desorption of the matrix on both surfaces of the stimuli-responsive reversible deformable structure by changing the composition, degree of curing, crosslink density and film thickness of the matrices 21 and 23. It is. Thus, the direction of the curl can be changed according to the difference in the amount of water and the amount of desorption on the front and back.

  The material constituting the matrices 21 and 23 is not particularly limited as long as it exhibits a volume change with the adsorption and desorption of moisture, and the matrix material 11 described in the stimulus-responsive reversible deformable structure 1 described above. The same material can be used.

  The same material as the material of the base film 12 described in the stimuli-responsive reversible deformable structure 1 can be used as a material of the base film 22.

(Stimuli-responsive reversible deformable structure 3)
FIG. 6 is a schematic cross-sectional view showing an example of the stimuli-responsive reversible deformable structure 3 having a film-like structure according to the present embodiment, and a schematic view of the surface viewed from the A side. A matrix 31 is formed on a part of the base film 32, and a plurality of cuts 33 are inserted between AB so as to penetrate the stimuli-responsive reversible deformable structure in a certain portion of the matrix 31.

  In such a configuration, when moisture is desorbed from the matrix 31, only the portion where the matrix 31 and the cut 33 are formed curls as shown in FIG. 7, and the portion where the matrix 31 is not formed remains smooth. It becomes. The entire stimulus-responsive reversible deformable structure remains smooth, and only the portion where the matrix 31 is formed is curled.

  When making a cut, as shown in FIG. 8, the shape of the cut 33 is not particularly limited, but it is essential that the cut 33 penetrate on both sides of the stimulus-responsive reversible deformation structure 3. The cut 33 may be formed by a plurality of straight lines, or may be a shape cut out by a polygon or a circle. Also, the cut portion may or may not cover a portion having no matrix. It suffices if curl is generated by adsorption and desorption of moisture.

  The number, number density, and size of the matrix 31 and the cuts 33 formed on the surface of the base film 32 are not particularly limited.

  The material constituting the matrix 31 is not particularly limited as long as it exhibits a volume change with the adsorption and desorption of moisture, and is the same as the matrix material 11 described in the stimulus-responsive reversible deformable structure 1 described above. Materials can be used. Further, as described in the stimulus-responsive reversible deformable structure 2, it is also possible to arrange a matrix on the opposite side of the matrix 31 with the base film 32 therebetween.

  As a material constituting the base film 32, the same material as the material of the base film 12 described in the stimuli-responsive reversible deformation structure 1 can be used.

(Stimuli-responsive reversible deformation structure 4)
FIG. 9 (left diagram) is a schematic cross-sectional view showing an example of the stimulus-responsive reversible deformable structure 4 having a film-like structure according to the embodiment of the present invention. The matrix 41 is formed on a part of the base film 42 and bonded to a part of the printing base material 46 using an adhesive or an adhesive 45. In addition, a cut 43 is made in a portion of the matrix 41 between A and B so as to penetrate the stimuli-responsive reversible deformable structure. In the stimulus-responsive reversible deformation structure, a printing pattern 44 is formed on both the matrix 41 and the printing substrate 46. In such a form, when moisture is desorbed from the matrix 41, the entire stimulus-responsive reversible deformable structure remains smooth as shown in FIG. 9 (right figure), and the matrix 41 is formed. Only a part is curled. When viewed from the A side, the print pattern 44 changes before and after the desorption of moisture from the matrix 41.

  The print pattern 44 may be formed on one or both sides of the matrix 41 or on one or both sides of the base film 42.

  Further, as shown in FIG. 10, a printing base material 46 further provided with a printing pattern 44 is arranged, and as shown in FIG. The responsive reversible deformation structure 4 can also be used. Even in such a structure, the print pattern 44 changes before and after the desorption of moisture from the matrix 41.

  As shown in FIG. 12, a combination of a plurality of matrices 41, a base film 42, and a print pattern 44 may be bonded with an adhesive or an adhesive 45.

  In particular, when the base film 42 and the matrix 41 are transparent and the printing pattern 44 is formed of a printing pattern such as a halftone dot or a line, such that a plurality of overlapping optical interferences cause moire. The print pattern on the material film 42 or the matrix 41 and the print pattern on the print base material 46 optically interfere with each other to cause moire. Usually, the moire pattern changes by changing the observation angle, but in the present invention, the moire pattern can be changed by the adsorption and desorption of moisture without changing the observation angle.

  The number, density, and size of the matrix 41 and the cuts 43 in the stimuli-responsive reversible deformation structure 4 are not particularly limited.

  The material constituting the matrix 41 is not particularly limited as long as it exhibits a volume change with the adsorption and desorption of moisture. The same material as the material described in the stimuli-responsive reversible deformable structure 1 described above is used. Can be used. Further, as described in the stimuli-responsive reversible deformable structure 2, it is also possible to arrange a matrix on the opposite side of the matrix 41 via the base film.

  As the material constituting the base film 42, the same material as the material of the base film 12 described in the stimuli-responsive reversible deformable structure 1 can be used.

  As a material constituting the printing base material 46, the same material as the base film 12 described in the stimuli-responsive reversible deformation structure 1 can be used, and a rigid material such as a glass plate, a metal plate, and ceramics may be used. Absent.

  The material constituting the print pattern 44 is not particularly limited as long as it is colored, such as color ink, white ink, and black ink.

(Production method)
Next, a method for manufacturing the stimuli-responsive reversible deformable structure according to the embodiment of the present invention will be described using the stimuli-responsive reversible deformable structure 4 as an example.

  First, the above-described material for forming the matrix 41 and a solvent as necessary are mixed to prepare a matrix-forming coating liquid.

  A surface conditioner, an antifoaming agent, a rheology control agent, and the like can be added to the matrix forming coating liquid in order to improve coatability.

Next, the matrix forming coating liquid is coated on the base film 42.
Examples of the method of coating the base film 42 with the coating liquid for forming a matrix include existing coating methods such as a screen printing method, a doctor blade method, a gravure printing method, a die coating method, an ink jet method, and a dispenser method. do not do.

  The thickness of the matrix 41 is preferably about 10 μm to 200 μm, more preferably about 20 μm to 150 μm. However, the thickness of the matrix 41 is not limited to the above range.

Next, the coating liquid applied on the base film is appropriately dried by heat treatment to remove the solvent in the coating liquid, thereby forming a coating film. For the heat treatment, a known drying means can be appropriately employed. For example, heating, blowing, hot air, far-infrared rays, or the like can be used as the drying means.
It should be noted that by adjusting the water content of the coating film at this time, it is also possible to adjust the water content without curl in FIG.

When an ionizing radiation curable resin is used as the material of the matrix 41, an ionizing radiation irradiating step is provided after the heat treatment step, and the coating film is cured by irradiating it with ionizing radiation to form a coating film.
As the ionizing radiation in the present invention, ultraviolet rays, electron beams and the like can be adopted. In the case of ultraviolet curing, a light source such as a high-pressure mercury lamp, a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, and a UV-LED can be used. The integrated light amount and illuminance vary depending on the resin used, but usually, a multi-stage ultraviolet light source is provided on the transport line, and irradiation is performed by dividing into plural light sources. In particular, in the first-stage ultraviolet irradiation, the temperature of the web is preferably kept at 60 ° C. or lower in order to reduce an increase in internal stress due to runaway of photopolymerization. By adjusting the degree of curing, it is also possible to adjust the water content without the curl in FIG.

  Also, a coating film is separately prepared, a coating liquid for forming a matrix is applied to the coating film, dried and cured, and then the matrix alone is peeled off from the coating film. It is also possible to bond using. At this time, after adsorbing and desorbing moisture in a state in which the matrix has no curl, an adhesive film is attached and then attached to the base film 42. The coating film is not particularly limited as long as the matrix is easily peeled off. Even in this way, it is possible to adjust the water content without curl in FIG.

  Then, a printing pattern 44 is formed on the matrix 41 and the base film 42 by printing. The shape and size of the print pattern 44 are not particularly limited, and can be appropriately selected depending on the use and function to be used, the printing method, and the like. In particular, when moire is developed, a pattern printing method such as screen printing, offset printing, or inkjet printing can be used for the printing pattern.

Next, cuts 43 are made in predetermined places of the matrix 41 and the base film 42.
Cuts 43 are made in the matrix 41 and the base film 42 using, for example, a roll cutter, press perforation, or the like, but the method is not particularly limited.

  The matrix 41 and the base film 42 can have various three-dimensional shapes. As the embossing method, nano-imprinting, hot pressing using a fine mold, or the like can be used.

  Further, the matrix 41 and the base film 42 can be colored.

  Hereinafter, the present invention will be described with reference to specific examples.

(Method of measuring curl)
The curl amount was obtained by cutting out the stimuli-responsive reversible deformable structure into a size of 5 mm × 50 mm, and after adsorbing and desorbing moisture, a radius of curvature was measured after 5 minutes. The environment for measuring the curl was 23 ° C. except for the humidity conditions. In the case of directly applying water, the measurement was carried out after wiping off water adhering to the surface after 5 minutes. Those having a radius of curvature exceeding 300 mm were treated as flat.

(Stimuli-responsive reversible deformable structure 1)
Table 1 below summarizes data on Examples 1 to 12 of the stimulus-responsive reversible deformable structure 1. In the table, a positive radius of curvature means that a curl having a convexity on the base film side has occurred. The one with ∞ means almost smooth. In the case of a negative number, it means that a curl with the matrix side being convex has occurred.

(Example 1)
First, a matrix forming coating liquid 1 was prepared. Hydrophilic UV-curable resin UA-W2A (Shin-Nakamura Chemical Co., Ltd., 12 parts by weight), hydrophilic UV-curable monomer HEAA (KJ Chemicals, 82 parts by weight), water-swellable layered clay mineral LAPONITERS (BYK) Co., Ltd., 6 parts by weight), a photopolymerization initiator Irgacure 2959 (manufactured by BASF, 0.2 parts by weight), and pure water as a solvent were mixed to prepare a coating solution.

  Next, the film base material was polyethylene terephthalate (PET) (Lumirror T60, thickness 75 μm, manufactured by Toray Industries, Inc.) subjected to corona treatment. Further, the coating liquid for matrix formation 1 was applied to the film substrate using a bar coater. The coating amount of the coating liquid was set so that the dry film thickness was 45 μm.

  Next, the coating liquid 1 applied to the substrate was dried by heat treatment to form a coating film on the substrate. The heat treatment was performed at 100 ° C. for 1 minute.

Next, the coating film formed on the substrate was irradiated with ionizing radiation to cure the coating film, thereby producing a stimulus-responsive reversible deformable structure 1. At this time, ultraviolet rays were irradiated as ionizing radiation. Irradiation with ultraviolet rays was performed at an exposure amount of 420 mJ / cm ² using a conveyor-type ultraviolet curing device.

  The curl amount of the stimuli-responsive reversible deformable structure 1 is such that the base film side is convex, the radius of curvature is 14 mm at 25% RH, the flatness is approximately 50% RH, and the matrix side is convex at 75% RH. The radius was 280 mm. In Table 1, the radius of curvature when the matrix side is convex is shown as a negative value.

(Example 2)
A stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the dry film thickness was 55 μm. The curl amount of the stimuli-responsive reversible deformable structure 1 is such that the substrate film side is convex, the radius of curvature is 10 mm at 25% RH, almost flat at 50% RH, and the matrix side is convex at 75% RH. The radius was 240 mm.

(Example 3)
A stimuli-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the dry film thickness was 35 μm. The curl amount of the stimuli-responsive reversible deformable structure 1 was substantially flat at a curvature radius of 55 mm at 25% RH, 50% RH, and 75% RH with the base film side being convex.

(Example 4)
A stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the amount of exposure to ionizing radiation was set to 300 mJ / cm ² . The curl amount of the stimuli-responsive reversible deformable structure 1 is such that the substrate film side is convex, the radius of curvature is 35 mm at 25% RH, almost flat at 50% RH, and convex at the matrix side at 75% RH. The radius was 230 mm.

(Example 5)
A stimuli-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the amount of exposure to ionizing radiation was 500 mJ / cm ² . The curl amount of the stimuli-responsive reversible deformable structure 1 was substantially flat at a curvature radius of 80 mm at 25% RH, 50% RH, and 75% RH with the base film side being convex.

(Example 6)
The stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the time for drying the coating solution applied to the substrate by heat treatment was 5 minutes. The curl amount of the stimulus-responsive reversible deformable structure 1 was substantially flat at a curvature radius of 20 mm at 25% RH, a curvature radius of 180 mm at 50% RH, and 75% RH with the base film side being convex.

(Example 7)
A stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1 except that the thickness of the base film was 38 μm. The curl amount of the stimuli-responsive reversible deformable structure 1 is set such that the substrate film side is convex, the radius of curvature is 10 mm at 25% RH, almost flat at 50% RH, and the matrix side is convex at 75% RH. The radius was 200 mm.

(Example 8)
As the matrix forming coating liquid 2, hydrophilic UV-curable resin UA-W2A (Shin-Nakamura Chemical Co., Ltd., 24 parts by weight), hydrophilic UV-curable monomer HEAA (KJ Chemicals, 70 parts by weight), water swelling A coating liquid was prepared by mixing a layered clay mineral LAPONITERS (BYK, 6 parts by weight), a photopolymerization initiator Irgacure 2959 (BASF, 0.2 parts by weight), and pure water as a solvent. Except for this, the stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1. The curl amount of the stimuli-responsive reversible deformable structure 1 was substantially flat at a radius of curvature of 50 mm, 50% RH, and 75% RH at 25% RH, with the base film side being convex.

(Example 9)
As the matrix forming coating liquid 3, hydrophilic UV-curable resin UA-W2A (Shin-Nakamura Chemical Co., Ltd., 6 parts by weight), hydrophilic UV-curable monomer HEAA (KJ Chemicals, 88 parts by weight), water swelling A coating liquid was prepared by mixing a layered clay mineral LAPONITERS (BYK, 6 parts by weight), a photopolymerization initiator Irgacure 2959 (BASF, 0.2 parts by weight), and pure water as a solvent. Except for this, the stimulus-responsive reversible deformable structure 1 was produced under the same conditions as in Example 1. The curl amount of the stimuli-responsive reversible deformable structure 1 was such that the radius of curvature was 12 mm at 25% RH, 160 mm at 50% RH, and 250 mm at 75% RH with the base film side being convex. .

(Example 10)
A matrix forming coating liquid 1 was applied using a bar coater, using polyethylene terephthalate (PET) subjected to a release treatment as a coating substrate. The coating amount of the coating liquid was set so that the dry film thickness was 45 μm.

  Next, the coating liquid applied to the substrate was dried by heat treatment to form a coating film on the substrate. The heat treatment was performed at 100 ° C. for 1 minute.

Next, the coating film formed on the substrate was irradiated with ionizing radiation to cure the coating film. At this time, ultraviolet rays were irradiated as ionizing radiation. Irradiation with ultraviolet rays was performed at an exposure amount of 420 mJ / cm ² using a conveyor-type ultraviolet curing device.

  Next, the matrix formed on the base material was peeled off from the base material for application, and placed in a state of 23 ° C. and 50% RH in a smooth state for 5 minutes as a humidity control, and then a 10 μm adhesive film (25 μm thickness) was used. Laminated with polyethylene terephthalate (PET) (Lumirror T60, thickness 38 μm, manufactured by Toray Industries, Inc.), a stimulus-responsive reversible deformable structure 1 was produced. The curl amount of the stimuli-responsive reversible deformable structure 1 is such that the base film side is convex, the curvature radius is 80 mm at 25% RH, almost flat at 50% RH, and the matrix side is convex at 75% RH. The radius was 200 mm.

(Example 11)
A stimulus-responsive reversible deformable structure 1 was produced under the conditions of Example 10 except that the humidity was adjusted to 23 ° C. and 25% RH. The curl amount of the stimuli-responsive reversible deformable structure 1 is substantially flat at 25% RH, the radius of curvature is 250 mm with the matrix side convex at 50% RH, and the radius of curvature is 230 mm with the matrix side convex at 75% RH. there were.

(Example 12)
A stimulus-responsive reversible deformable structure 1 was produced under the conditions of Example 10 except that the humidity was adjusted to 23 ° C. and 75% RH. The curl amount of the stimulus-responsive reversible deformable structure 1 was substantially flat at a curvature radius of 10 mm at 25% RH, a curvature radius of 50% RH at 40 mm, and a curvature radius of 75% RH with the base film side being convex.

  Table 1 shows the results of Examples 1 to 12 described above.

(Stimuli-responsive reversible deformation structure 2)
(Example 13)
The stimulus-responsive reversible deformable structure 1 produced in Example 1 was subjected to a corona treatment on the side of the substrate film where the matrix was not formed, and the matrix was formed under the same conditions as in Example 1 to obtain stimulus-responsive properties. A reversibly deformable structure 2 was obtained. The curl amount of the stimulus-responsive reversible deformable structure 2 was substantially flat at 25% RH, 50% RH, and 75% RH. When water vapor was applied to one side of the matrix, a curl having a radius of curvature of 50 mm was formed with the non-exposed side of the matrix being convex.

(Stimuli-responsive reversible deformable structure 3)
(Example 14)
As shown in FIG. 13 (left diagram), four cuts were made in the stimuli-responsive reversible deformable structure 1 prepared in Example 1 to prepare a stimuli-responsive reversible deformable structure 3. When the stimulus-responsive reversible deformable structure 3 was placed in an environment of 25% RH, curl as shown in FIG. 13 (right figure) occurred.

(Stimuli-responsive reversible deformation structure 4)
(Example 15)
For the stimulus-responsive reversible deformable structure 1 prepared in Example 1, a line and space pattern having a line width of 50 μm and a pitch of 100 μm was printed with black ink using offset printing on the surface of the obtained matrix. Formed. Further, four cuts were made from the top of the pattern. A PET film was separately prepared, and a line and space pattern having a line width of 50 μm and a pitch of 100 μm was formed on the surface of the obtained matrix by offset printing using black ink. All were smooth in the state of 50% RH.
As shown in FIG. 14 (left figure), when these were overlapped to generate a moiré pattern and then placed in a state of 25% RH, a change in the moiré pattern was observed as shown in FIG. 14 (right figure).

(Stimuli-responsive reversible deformation structures 1-4)
(Comparative example)
As a matrix that does not exhibit a volume change due to the adsorption and desorption of moisture, 100 parts by mass of Shikko UV7000B (Nippon Synthetic Chemical Industry) and 1 part by mass of ESACURE ONE (manufactured by Lamberti) are dissolved in methyl ethyl ketone to prepare a coating solution. Examples 1 to 15 described above were prepared except that this coating liquid was used as a coating liquid for forming a matrix, but no change in the amount of curl due to the adsorption and desorption of water and no visual effect was exhibited.

  From the above results, it was found that the stimulus-responsive reversible deformable structure of the present invention can give a reversible change in the amount of curl, and can produce an excellent visual change.

1: Stimuli-responsive reversible deformable structure 1
11 Matrix 12 Base film 13 Stress 2 Stimuli-responsive reversible deformable structure 2
21 matrix 22 base film 23 matrix 3 stimuli-responsive reversible deformable structure 3
31 Matrix 32 Base film 33 Cut 4 Stimuli-responsive reversible deformable structure 4
41 Matrix 42 Base film 43 Cut 44 Print pattern 45 Adhesive or adhesive 46 Print base

Claims (8)

A substrate and a structure having a matrix on at least one side thereof,
The matrix is made of a resin having a property of adsorbing and desorbing moisture,
A stimuli-responsive reversible deformable structure, wherein the curl amount of the structure changes due to a volume change caused by the adsorption and desorption of moisture in the matrix.   The stimulus-responsive reversible deformable structure according to claim 1, wherein the resin is a polymer or a copolymer of a curable resin.   The stimulus-responsive reversible deformable structure according to claim 1, wherein the curable resin has ionizing radiation curability or thermosetting property.   The volume change accompanying the adsorption and desorption of moisture in the matrix is controlled by any one of the composition of the matrix, the degree of curing, the crosslink density, and the degree of polymerization. 3. The stimuli-responsive reversible deformable structure according to item 1.   The stimuli-responsive reversible deformable structure according to any one of claims 1 to 4, wherein at least the matrix or the substrate surface on which the curl amount of the structure changes is printed with ink.   In the structure, a plurality of cut portions having a cut-like hole formed through the matrix and the base material are arranged, and curl of the cut portion is caused by a volume change caused by adsorption and desorption of moisture in the matrix. The stimuli-responsive reversible deformable structure according to any one of claims 1 to 5, wherein the amount changes. A method for producing a stimuli-responsive reversible deformable structure according to any one of claims 1 to 6,
A coating liquid preparation step of preparing a coating liquid containing a curable resin material,
An application step of applying the coating liquid on a substrate,
A heat treatment step of heat treating the coating liquid to form a coating film,
Irradiating the coating film with ionizing radiation to cure and form a cured film, an ionizing radiation irradiation step of forming a matrix composed of the cured film supported on the base material,
A method for producing a stimuli-responsive reversible deformable structure, comprising at least: The method for producing a stimuli-responsive reversible deformable structure according to claim 7,
Forming a printing pattern on the matrix or the substrate,
In the step of performing a notch-shaped hole processing in the matrix,
A method for producing a stimuli-responsive reversible deformable structure, further comprising one or both steps.