JP6048624B1 - Decorative sheet and method for producing the decorative sheet - Google Patents

Abstract

The decorative sheet of the present invention includes a base material 1 made of an inorganic material, a printed layer 2 formed by applying an ink containing a photocurable resin to the base material 1 by an inkjet method, and a base material 1. And a hard layer 3 disposed on the surface side on which the printing layer 2 is provided. The substrate 1 is preferably made of metal. It is preferable that the hard layer 3 is comprised with the material containing a melamine type resin.

Description

  The present invention relates to a decorative sheet and a method for manufacturing the decorative sheet.

  A good-looking space is produced by attaching a plurality of decorative sheets (decorative plates) to the walls of buildings, hotels, condominiums, conference rooms, and office walls. Such decorative sheets are used not only as real estate, but also as interior materials for vehicles such as trains and interior materials for aircraft.

  Such a decorative sheet has a hard layer composed of a melamine resin or the like on the surface, has an excellent hardness, and is hardly damaged.

  And the decorative sheet generally has a paper base material on which various patterns such as wood grain tone and stone tone are provided by gravure printing.

  Gravure printing is excellent in productivity when printing the same pattern in large quantities, but it is necessary to prepare a new plate when printing different patterns. Even if the pattern is slightly changed, it is necessary to prepare a new plate. For these reasons, conventionally, it has been difficult to produce a small amount of various types of decorative sheets.

  In addition, for example, when a decorative sheet having a new pattern is produced, it is necessary to manufacture a plurality of plates by adjusting a delicate pattern or the like even in the trial production stage.

  In particular, when producing custom-made decorative sheets, a great deal of time is spent in the trial production stage.

  Therefore, it has not been possible to meet the demands of consumers who demand delivery of decorative sheets in a short period of time.

  In order to solve the above problems, for example, it is conceivable to employ an inkjet method as a printing method.

  However, when the ink jet method is used instead of gravure printing, the following problems occur.

  That is, when the ink jet method is simply used instead of gravure printing, the coloring property of the printed portion is inferior in the decorative sheet, and the aesthetics of the decorative sheet are not sufficient.

JP 2013-202906 A

  An object of the present invention is to provide a decorative sheet having a printing part formed by an ink jet method and having excellent color developability and aesthetics. Another object of the present invention is to provide a method for producing a decorative sheet, which can efficiently produce a decorative sheet that is formed by an ink jet method and has a printing portion that is excellent in color development and aesthetics.

Such an object is achieved by the present invention of the following (1) to ( 10 ).
(1) a base material composed of an inorganic material selected from the group consisting of metals, metal compounds and carbon-based materials ;
A printed layer provided on the substrate and containing a cured product of a photocurable resin;
A decorative sheet comprising: a hard layer formed of a hard material having a surface Martens hardness of 300 MPa to 800 MPa , which is provided on a surface side of the substrate on which the printed layer is provided.

  (2) The decorative sheet according to (1), wherein the thickness of the base material is 10 μm or more and 300 μm or less.

  (3) The said base material is a decorative sheet as described in said (1) or (2) comprised with the metal material.

( 4 ) The decorative sheet according to any one of (1) to ( 3 ), wherein the hard layer is made of a material containing a melamine resin.

( 5 ) The decorative sheet according to any one of (1) to ( 4 ), further including a core material provided on the surface of the substrate opposite to the printed layer.

( 6 ) The decorative sheet according to ( 5 ), wherein the core material is made of glass cloth.

(7) metal, a step of applying an ink containing a photo-curing resin in the inkjet method relative to the metal compounds and groups composed of an inorganic material material selected from the group consisting of carbon-based material,
Curing the photocurable resin to form a printed layer; and
Forming a hard layer having a surface Martens hardness of 300 MPa or more and 800 MPa or less on the surface side of the substrate on which the printed layer is provided.

( 8 ) The method for producing a decorative sheet according to ( 7 ), further including a step of bonding a core material to the surface of the substrate opposite to the printed layer.

( 9 ) The method for manufacturing a decorative sheet according to ( 8 ), wherein the step of bonding the core material is performed after the step of curing the photocurable resin.

( 10 ) The method for producing a decorative sheet according to ( 8 ) or ( 9 ), wherein the photocurable resin is an ultraviolet curable resin.

  ADVANTAGE OF THE INVENTION According to this invention, the decorative sheet which has the printing part formed with the inkjet method and excellent in coloring property and aesthetics can be provided. Moreover, the manufacturing method of the decorative sheet which can manufacture efficiently the decorative sheet which has a printing part excellent in coloring property and aesthetics can be provided.

FIG. 1 is a cross-sectional view showing a preferred embodiment of the decorative sheet of the present invention. FIG. 2 is a cross-sectional view showing another preferred embodiment of the decorative sheet of the present invention. FIG. 3 is a cross-sectional view showing a preferred embodiment of the method for producing a decorative sheet of the present invention. FIG. 4 is a cross-sectional view showing another preferred embodiment of the decorative sheet of the present invention. FIG. 5 is a cross-sectional view showing another preferred embodiment of the decorative sheet of the present invention.

  Hereinafter, a decorative sheet and a method for manufacturing the decorative sheet of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<< Cosmetic sheet >>
First, the decorative sheet will be described.

  A decorative sheet can be attached to the walls of buildings, hotels, condominium lobbies, conference rooms, offices, etc. to improve the appearance of the space. In addition, the decorative sheet may be used not only as a real estate but also as an interior material for a vehicle such as a train.

  FIG. 1 is a sectional view showing a preferred embodiment of the decorative sheet of the present invention, and FIG. 2 is a sectional view showing another preferred embodiment of the decorative sheet of the present invention.

  A decorative sheet 100 shown in FIG. 1 includes a base material 1, a printing layer (printing unit) 2, a hard layer (hard material layer) 3 disposed on the surface side of the base material 1 on which the printing layer 2 is provided, It has the core material 4 provided in the surface side opposite to the surface in which the printing layer 2 of the base material 1 was provided. Moreover, the decorative sheet 100 shown in FIG. 2 has the base material 1, the printing layer (printing part) 2, and the hard layer 3 distribute | arranged to the surface side in which the printing layer 2 of the base material 1 was provided. Yes.

  When the decorative sheet 100 is used, the upper side in FIGS. 1 and 2 is the observer's viewpoint side.

<Base material>
The substrate 1 is made of an inorganic material. By providing such a substrate 1, the color development of the printing layer 2 (the printing layer 2 formed by ejecting an ink containing a photocurable resin by an ink jet method) as described in detail later is excellent. The aesthetics of the decorative sheet 100 can be improved.

  On the other hand, for example, when a paper base is used, the ink applied by the ink jet method excessively penetrates into the base (paper base) during the production of the decorative sheet, and the color of the printed layer is increased. And aesthetics of the decorative sheet cannot be sufficiently enhanced. Further, for example, when a base material made of a resin material (plastic) is used, when the ink containing the photocurable resin is applied during the manufacture of the decorative sheet, the ink erodes the base material. The surface roughness of the substrate, the deformation of the pattern, and the like are caused, and the aesthetics of the decorative sheet cannot be sufficiently improved.

  Further, when a paper base material is used, since the paper itself is easy to burn, it may be difficult to increase the flame retardancy of the decorative sheet. On the other hand, in this invention, the flame retardance as the whole decorative sheet 100 can be improved easily and reliably by using the base material 1 comprised with the inorganic material.

  In addition, when a paper base material is used, even if a printing layer and a hard layer are provided, the bending elastic modulus of the decorative sheet as a whole is small, so that the decorative sheet is not sufficient. Therefore, the ease of handling of the decorative sheet (for example, the ease of work of attaching to a wall or the like) is low, and it is necessary to provide a core material or the like. On the other hand, in the present invention, as shown in FIG. 2, if the base material 1, the printed layer 2, and the hard layer 3 are used without using the core material, the substrate has sufficient stiffness and is excellently handled. A decorative sheet 100 having ease can be obtained. Moreover, since it is not necessary to provide a core material etc., the decorative sheet 100 can be reduced in weight suitably and bending workability etc. can be improved especially.

  Further, the paper base material is easily affected by humidity and easily causes problems such as dimensional change due to moisture absorption. However, the use of the base material 1 made of an inorganic material effectively prevents the occurrence of such a problem. Can be prevented.

  The base material 1 should just be comprised with the inorganic material, and as a constituent material of the base material 1, various metals, various metal compounds (For example, metal oxide, metal nitride, metal carbide, metal sulfide, etc.), for example. ), Various carbon materials (graphite, carbon nanotube, diamond-like carbon (DLC), etc.), various glasses, and the like.

  Moreover, the base material 1 may be a dense sheet or may have pores. Further, the substrate 1 may be a fibrous substrate such as a nonwoven fabric, a cloth, or a woven fabric.

  In particular, when the base material 1 is made of metal, the color development of the printing layer (printing portion) 2 is particularly excellent, so that the aesthetics of the decorative sheet 100 can be particularly improved. Moreover, the bending workability, durability, etc. of the decorative sheet 100 can be particularly improved.

  Examples of the metal material constituting the substrate 1 include aluminum, titanium, iron, gold, silver, platinum, palladium, copper, zinc, nickel, chromium, and alloys containing at least two of these. However, aluminum is particularly preferable.

  Thereby, since the coloring property of the printing layer (printing part) 2 is further excellent, the aesthetics of the decorative sheet 100 can be further improved. Moreover, the bending workability, durability, etc. of the decorative sheet 100 can be further improved. In particular, since aluminum is excellent in chemical stability, a change in appearance of the decorative sheet 100 over time is suitably prevented, and excellent aesthetics can be exhibited stably over a long period of time. In addition, aluminum has a silvery white color and does not adversely affect the color of the printing layer 2 provided on the substrate 1. Moreover, aluminum can be applied to various decorative sheets 100 having the printed layers 2 having various patterns, and is suitable for manufacturing a wide variety of decorative sheets 100. Moreover, since aluminum has a relatively small specific gravity among various metals, it is advantageous in reducing the weight of the decorative sheet 100 while obtaining the excellent effects as described above. Moreover, when the base material 1 is comprised with aluminum, the adhesiveness with the base material 1 and the printing layer 2 (printing layer 2 formed by hardening | curing the ink containing photocurable resin) explained in full detail later is especially Since it is excellent, the durability and reliability of the decorative sheet 100 can be particularly improved.

Moreover, the base material 1 may be comprised with the glass cloth.
Thereby, since a part of printing layer 2 can be made to penetrate | invade into the clearance gap between the fibers which comprise the base material 1 (glass cloth), the adhesiveness of the base material 1 and the printing layer 2 is improved especially, and the decorative sheet 100 The durability, reliability, etc. can be particularly improved. Further, since the glass cloth is a lightweight and particularly highly flame retardant material, it is preferable from the viewpoint of reducing the weight of the decorative sheet 100 as a whole and improving the flame retardancy. Moreover, when the base material 1 is comprised by the glass cloth, even if the structure which does not have the core material 4 (refer FIG. 2), optimal firmness (tension) is obtained, the simplification of the structure of the decorative sheet 100, and lightweight Can be achieved.

  Although the thickness of the base material 1 is not specifically limited, It is preferable that they are 10 micrometers or more and 300 micrometers or less, and it is more preferable that they are 20 micrometers or more and 120 micrometers or less.

  Thereby, the bending workability, durability, reliability, and the like of the decorative sheet 100 can be particularly improved while the decorative sheet 100 is thinned.

<Print layer>
The substrate 1 is provided with a printing layer 2 formed by an ink jet method.

  By adopting the ink jet method in this way, unlike gravure printing or the like, it is not necessary to prepare a plate, and it is possible to suitably form printing portions (printing layers) 2 having various patterns in a short period of time. Therefore, a wide variety of decorative sheets 100 can be suitably provided.

  Moreover, since it can respond suitably also to the fine adjustment of a pattern etc., it can respond to a consumer's request | requirement exactly.

  The printing layer 2 is formed by applying an ink containing a photocurable resin by an inkjet method.

  In such a case, the adhesion between the substrate 1 (substrate 1 made of an inorganic material) and the printing layer 2 (printing layer 2 made of a material containing a cured product of a photocurable resin) is excellent. The durability and reliability of the decorative sheet 100 can be improved.

  Moreover, since the ink containing a photocurable resin is used, excessive wetting and spreading of the ink on the substrate 1 by adjusting the timing of light irradiation for curing the photocurable resin, The printing layer 2 can be formed while effectively preventing ink repelling or the like on the substrate 1. Therefore, the printed layer 2 having a desired shape and pattern can be easily and reliably formed, and the aesthetics of the decorative sheet 100 can be reliably improved.

  In addition, since the base material 1 made of an inorganic material is excellent in resistance to ink containing a photocurable resin, surface roughness of the base material 1 at the time of ink application is reliably prevented, and the decorative sheet 100 is aesthetically aesthetic. Can be improved with certainty.

  Such an excellent effect can be obtained by forming the printing portion 2 by an ink jet method using an ink containing a photocurable resin with respect to the base material 1 made of an inorganic material. It cannot be obtained if the various conditions are not satisfied. For example, when a base material (paper base material, plastic base material) composed of an organic material is used, or when ink is applied by a method other than the inkjet method, an ink that does not contain a photocurable resin (for example, photocuring) In the case of using an ink containing water as a solvent and not containing a curable resin, or an ink containing an organic solvent as a solvent and not containing a photocurable resin, the above-described excellent effects cannot be obtained.

  The printing layer 2 is made of a material containing a cured product of a photocurable resin, but may contain other components. Examples of such components include colorants, slip agents (leveling agents), dispersants, penetration enhancers, wetting agents (humectants), fixing agents, antifungal agents, antiseptics, antioxidants, chelating agents, A thickener, an antifoamer, a sensitizer (sensitizing dye), etc. are mentioned.

  The print layer 2 may be provided in any pattern, but is usually determined according to the demand of the customer.

  Examples of the pattern of the printing layer 2 include a wood tone, a stone tone, a metal tone with a line processing, various geometric patterns, and the like.

<Hard layer>
A hard layer 3 is disposed on the side of the substrate 1 on which the printing layer 2 is provided.

  By having such a hard layer 3, the decorative sheet 100 has excellent surface hardness and is less likely to be damaged.

The hard layer 3 also has a function of protecting the print layer 2 and the like.
Therefore, the pattern of the printing layer 2 can be suitably displayed stably over a long period of time. In other words, the decorative sheet 100 has particularly excellent durability.

  Examples of the constituent material of the hard layer 3 include a melamine resin, vinyl chloride, and a phenol resin. The hard layer 3 is preferably made of a material containing a melamine resin.

  When the hard layer 3 is comprised with the material containing a melamine-type resin, generally the decorative sheet 100 has moderate elasticity and rigidity, and has the outstanding handleability (easiness of handling). In addition, the melamine-based resin has an appropriate surface hardness, and is particularly excellent in scratch resistance, antifouling property (hardness of adhesion of dirt), etc., and thus improves the aesthetics and durability of the decorative sheet 100. It is also preferable from the viewpoint.

The hard layer 3 preferably has a Martens hardness of 300 MPa or more and 800 MPa or less, more preferably 400 MPa or more and 600 MPa or less, on the surface (the surface opposite to the surface facing the substrate 1).
Thereby, it is possible to make the decorative sheet 100 particularly difficult to be damaged.

  On the other hand, when the Vickers hardness of the surface of the hard layer 3 is less than the lower limit value, the hard layer 3 has low abrasion resistance and is easily scratched.

  Moreover, when the Vickers hardness of the surface of the hard layer 3 exceeds the said upper limit, the workability of the decorative sheet 100 may become low.

  In the present invention, as the value of Vickers hardness, a value obtained by measurement according to JIS Z 2244: 2009 is adopted.

  The arithmetic average roughness Ra of the surface of the hard layer 3 (surface opposite to the surface facing the substrate 1) is preferably 300 nm or less, and more preferably 150 nm or less.

  Thereby, the surface of the hard layer 3 becomes smoother, and the sense of quality of the decorative sheet 100 can be further increased.

Further, the outer surface of the hard layer 3 (surface opposite to the surface facing the substrate 1) may be subjected to surface finishing such as mirror finishing or embossing finishing.
Thereby, the further improvement of the aesthetics of the decorative sheet 100 can be aimed at.

<Core material>
In the configuration shown in FIG. 1, a core material (core material layer) 4 is provided on the side of the substrate 1 opposite to the surface on which the printed layer 2 is provided.

  Thereby, especially the rigidity of the decorative sheet 100 is excellent. For example, even when the base material 1 has low rigidity, the decorative sheet 100 is particularly excellent in shape stability and ease of handling. Moreover, for example, the heat resistance and nonflammability of the decorative sheet 100 are particularly excellent.

  Examples of the core material 4 include a member made of glass cloth, a member having a layer made of phenolic resin, and a member having a metal layer.

Among these, the core material 4 is preferably made of glass cloth.
Thereby, the heat resistance, nonflammability, etc. of the decorative sheet 100 can be particularly improved while optimizing the rigidity and flexibility of the decorative sheet 100.

  The glass cloth is not particularly limited, and examples thereof include a glass woven fabric and a glass nonwoven fabric. Among these, a glass woven fabric is preferable from the viewpoint of nonflammability and strength.

  Moreover, as glass which comprises a glass cloth, E glass, C glass, A glass, S glass, D glass, NE glass, T glass, H glass etc. are mentioned, for example. Among these, when T glass is used, the thermal expansion coefficient of the glass cloth can be reduced. Moreover, when E glass is used, the production cost of the decorative sheet 100 can be further lowered while ensuring a sufficient function.

The weight of the glass cloth is not particularly limited. However, if it is necessary to satisfy the “non-combustible crack / penetration after combustion” requirement of Article 2, 9 of the Building Standards Act, the basis weight may be 80 g / m ² or more. preferable. Moreover, although the upper limit of a weight does not require a restriction | limiting especially, the basic weight of 250 g / m < ² > or less is preferable from the surface of material cost and workability.

  The core material 4 may be a member in which a plurality of layers are stacked. For example, the core material 4 can be formed by overlapping and joining a plurality of members obtained by impregnating a fibrous base material with a fibrous base material (for example, a base material made of paper such as kraft paper).

The thickness (average thickness) of the core material 4 is preferably 100 μm or more.
Thereby, the heat resistance and nonflammability of the decorative sheet 100 can be particularly improved. Further, the upper limit of the thickness is not particularly limited. However, as the thickness increases, the thickness and weight of the decorative sheet 100 increase and the cost also increases. Therefore, it is preferable to set the allowable range in the design of the final product. 350 μm or less is preferable.

  In addition, the decorative sheet 100 preferably has an overall thickness (average thickness) of 0.1 mm to 2 mm, and more preferably 0.1 mm to 1.2 mm.

  Thereby, the decorative sheet 100 is particularly excellent in workability and handleability while having sufficient strength.

<< Method for manufacturing decorative sheet >>
Next, the manufacturing method of a decorative sheet is demonstrated.

FIG. 3 is a cross-sectional view showing a preferred embodiment of the method for producing a decorative sheet of the present invention.
As shown in FIG. 3, the manufacturing method of the present embodiment includes (1a) a step of preparing the base material 1 (base material preparation step), and (1b) applying ink 2 ′ to the base material 1 by an inkjet method (1c) a step (curing step) of curing the photocurable resin contained in the ink 2 'applied on the substrate 1 to form the printing layer 2 (1d) A step of forming the hard layer 3 (hard layer forming step) on the surface side of the substrate 1 on which the printed layer 2 is provided; and (1e) a core material (on the surface side opposite to the printed layer 2 of the substrate 1). (Core material layer) 4 is joined (core material joining process).

<Base material preparation process>
In the base material preparation step, the base material 1 as described above is prepared (1a).

  When the base material 1 is composed of a metal material, the base material 1 is formed by, for example, a film formed by a vapor deposition method such as vapor deposition, a film formed by a wet plating method, or a film formed by thermal spraying. The metal foil is preferable.

  Metal foils made of various metal materials are easily and stably available and are generally inexpensive. Therefore, stable production of the decorative sheet 100 is possible, and it is possible to more reliably prevent problems such as a delay in delivery date. There is no need to secure excess inventory.

  In addition, the base material 1 prepared in this step may be subjected to various surface treatments (surface activation treatment) such as plasma treatment, ultraviolet irradiation treatment, primer treatment, etc. prior to the subsequent ink application step. Thereby, especially the adhesiveness of the base material 1 and the printing layer 2 is excellent.

<Ink application process>
Next, ink 2 ′ containing a photocurable resin is applied to the base material 1 prepared in the above step by an inkjet method (1b).

  By applying the ink 2 ′ using the ink jet method, unlike the case of adopting gravure printing or the like, it is not necessary to prepare a plate, and the printing layer 2 having various patterns can be suitably formed in a short period of time. . Therefore, a wide variety of decorative sheets 100 can be suitably provided.

  Moreover, since it can respond suitably also to the fine adjustment of a pattern etc., it can respond to a consumer's request | requirement exactly.

In this step, a plurality of types of inks 2 ′ may be used.
Thereby, for example, the color reproduction range is widened, and a delicate gradation can be expressed more suitably.
The ink 2 ′ used for forming the print layer 2 will be described in detail below.

<Curing process>
Next, the photocurable resin contained in the ink 2 ′ applied to the substrate 1 is cured to form the solid print layer 2 (1c).

  In particular, since the ink 2 ′ includes a photocurable resin, the productivity of the decorative sheet 100 is particularly excellent, and the adhesion of the printing layer 2 to the base material 1 can be improved, and the durability of the decorative sheet 100 is improved. Excellent reliability.

  In addition, since the ink 2 ′ containing a photo-curable resin is used, adjusting the timing of light irradiation or the like may cause excessive wetting and spreading of the ink 2 ′ on the substrate 1 or on the substrate 1. The printed layer 2 can be formed while effectively preventing the ink 2 'from being repelled. Therefore, the printing layer 2 having a desired shape and pattern can be easily and reliably formed, and the decorative sheet 100 can surely exhibit excellent aesthetics.

The curing reaction of the photocurable resin is performed by light irradiation.
The type of light to be irradiated varies depending on the type of the photocurable resin contained in the ink 2 ′, but the photocurable resin is an ultraviolet curable resin, and it is preferable to irradiate with ultraviolet rays in this step.

  Thereby, the reaction rate of the curing reaction of the photocurable resin is particularly excellent, and the productivity of the decorative sheet 100 is particularly excellent. Moreover, since a widely distributed ultraviolet lamp or the like can be used as a light source for ultraviolet irradiation, a special light source is not required, and the configuration of the manufacturing apparatus for the decorative sheet 100 can be simplified. it can. Therefore, the manufacturing cost of the decorative sheet 100 can be reduced. Moreover, since the cured product of the ultraviolet curable resin generally has high transparency, it is possible to more effectively prevent the color tone of the printing unit 2 from being adversely affected.

When irradiating with ultraviolet rays in this step, the peak wavelength of the ultraviolet rays is preferably 200 nm or more and 450 nm or less, and more preferably 200 nm or more and 400 nm or less.
Thereby, the effects as described above are more remarkably exhibited.

  In this step, the substrate 1 may be heated. Thereby, the curing reaction of the photocurable resin is promoted, and the productivity of the decorative sheet 100 is particularly excellent.

  In the illustrated configuration, for the sake of easy understanding, the procedure for performing the curing step (1c) after the ink application step (1b) is completed is shown. However, the ink application step and the curing step are performed simultaneously. May be performed sequentially. For example, the ink may be applied to other portions of the pattern while performing the curing process on the ink 2 ′ applied to the portion corresponding to a part of the target pattern. Thereby, the productivity of the decorative sheet 100 can be particularly improved.

  Moreover, the printing layer 2 formed at this process does not need to complete | finish polymerization reaction. Even in such a case, the polymerization reaction of the constituent components of the printing layer 2 can be advanced in a later step, and finally a decorative sheet 100 having sufficiently excellent durability, reliability, and the like is obtained. be able to.

<Hard layer forming process>
Next, the hard layer 3 is formed on the side of the substrate 1 on which the printed layer 2 is provided (1d).

  Thereby, the printing layer 2 etc. are protected suitably and the decorative sheet 100 finally obtained is excellent in surface hardness, and becomes hard to be damaged. Therefore, the pattern of the printing layer 2 can be suitably displayed stably over a long period of time. In other words, the decorative sheet 100 has particularly excellent durability.

  The hard layer 3 is a composition for forming a hard layer by various methods such as a dipping method, a spray method, a coating method using various coaters such as a roll coater, a knife coater, and a blade coater, and various printing methods. Can be suitably formed by applying to the surface side of the substrate 1 on which the printing layer 2 is provided and then performing a curing reaction.

  The composition used for forming the hard layer 3 (hard layer forming composition) will be described in detail below.

  Further, the hard layer 3 may be formed by bonding a molded member (hard layer forming member) formed into a sheet shape to the surface side of the substrate 1 on which the printed layer 2 is provided.

The molded member and the substrate 1 can be joined by, for example, pressure bonding.
When joining a shaping | molding member and the base material 1 by pressure bonding, you may heat the joining of the base material 1 and a shaping | molding member at the time of pressure bonding, for example.

  Thereby, the productivity of the decorative sheet 100 can be particularly improved, and the bonding strength between the substrate 1 and the hard layer 3 is particularly excellent. For example, since the polymerization reaction of the components contained in the hard layer 3 can be suitably advanced, the hardness of the hard layer 3, the durability of the decorative sheet 100, and the reliability are particularly excellent.

  The conditions for pressure-bonding the molded member and the substrate 1 are not particularly limited. For example, the temperature is 40 ° C. or more and 120 ° C. or less, the pressure is 0.5 MPa or more and 8 MPa or less, and the time is 3 minutes or more and 120 minutes or less. be able to.

  Thereby, the effects as described above can be exhibited more significantly while effectively preventing unintentional modification, deterioration, and the like of the constituent materials.

  In addition, when the molded member and the substrate 1 are joined, a mirror finish can be achieved by overlapping a mirror finish plate on the outer surface of the molded member (the surface opposite to the surface facing the substrate 1). By embossing an embossed plate or an embossed film, an embossed finish can be achieved.

  In the hard layer 3 formed in this step, the polymerization reaction may not be completed. Even in such a case, the polymerization reaction of the constituent components of the hard layer 3 can be advanced in a later step, and finally, a decorative sheet 100 having particularly excellent durability, reliability, and the like can be obtained. it can.

<Core material joining process>
Next, a core material (core material layer) 4 is provided on the surface of the substrate 1 opposite to the printed layer 2 (1e).
Thereby, the decorative sheet 100 is obtained.

  Thus, by having the core material joining process which joins the base material 1 and the core material 4, the rigidity of the decorative sheet 100, etc. improve, and the stability of the shape of the decorative sheet 100 and the ease of handling are excellent. . Moreover, for example, the heat resistance and nonflammability of the decorative sheet 100 are particularly excellent.

  In particular, in this embodiment, the core material joining process which joins the base material 1 and the core material 4 is performed after the hardening process mentioned above.

  Thereby, the process before a core material joining process can be performed more smoothly, and the productivity of the decorative sheet 100 can be improved especially. For example, the transportability of the substrate 1 in the ink application process can be improved.

For example, when the core material 4 includes a resin material, the core material 4 and the base material 1 can be joined by melting and softening a part of the core material 4 and closely contacting the base material 1.
Moreover, you may perform joining of the core material 4 and the base material 1 by adhesion | attachment, for example.

  In addition, when setting it as the structure which does not have the core material 4 as the decorative sheet 100, the decorative sheet 100 can be manufactured by skipping the core material joining process mentioned above.

<Ink>
Hereinafter, the ink 2 ′ used for forming the printing layer 2 will be described in detail.

  As described above, the ink 2 ′ used for forming the printing layer 2 includes at least a photocurable resin as described above.

Hereinafter, components of the ink 2 ′ will be described.
(Photo-curing resin)
The ink 2 ′ contains a photocurable resin (polymerizable compound).

  By including the photocurable resin, the adhesion between the substrate 1 made of an inorganic material and the printed layer 2 can be improved. In addition, by including a photocurable resin, the curable resin (photocurable resin) contained in the ink 2 ′ can be reliably cured at an appropriate timing easily and surely in the above-described curing step. The printing layer 2 having a desired shape and pattern can be easily and reliably formed.

  The photo-curable resin only needs to undergo a curing reaction (polymerization reaction) upon irradiation with light. For example, a resin that undergoes a curing reaction (polymerization reaction) upon irradiation with visible light, or a curing reaction (polymerization reaction) upon irradiation with ultraviolet light. ) Resin (ultraviolet curable resin) or the like can be used, but an ultraviolet curable resin in which a curing reaction (polymerization reaction) proceeds by irradiation with ultraviolet rays is preferable.

  Thereby, the reaction rate of the curing reaction of the photocurable resin is particularly increased, and the productivity of the decorative sheet 100 can be particularly improved. Moreover, since a widely distributed ultraviolet lamp or the like can be used as a light source for ultraviolet irradiation, a special light source is not required, and the configuration of the manufacturing apparatus for the decorative sheet 100 can be simplified. it can. Therefore, the manufacturing cost of the decorative sheet 100 can be reduced. Moreover, since the cured product of the ultraviolet curable resin generally has high transparency, it is possible to more effectively prevent the color tone of the printing unit 2 from being adversely affected.

The photocurable resin (polymerizable compound) is preferably in a liquid state at room temperature.
This makes it possible to sufficiently reduce the viscosity of the ink 2 ′ without using a liquid component (volatile component) removed (evaporated) in the process of manufacturing the decorative sheet 100 as a solvent or a dispersion medium. In addition, it is possible to suitably perform droplet discharge by the inkjet method. Therefore, it is possible to prevent deformation of the pattern accompanying the removal of the liquid component (volatile component), and it is possible to easily and reliably form the print layer 2 having a desired shape and pattern. Further, in the production of the decorative sheet 100, it is not necessary to provide a step of removing the liquid component (volatile component), and therefore the productivity of the decorative sheet 100 can be particularly improved. Moreover, since it is not necessary to use the component generally used as an organic solvent as a liquid component (volatile component), generation | occurrence | production of the problem of a volatile organic compound (VOC) can be prevented.

  As a photocurable resin (polymerizable compound), for example, various monomers, various oligomers (including dimers and trimers), prepolymers, and the like can be used. However, the ink 2 ′ preferably includes at least a monomer component as a photocurable resin (polymerizable compound). Since the monomer is generally a component having a low viscosity as compared with the oligomer component or the like, it is advantageous in particularly improving the ejection stability of the ink 2 'by the ink jet method.

  Although various photocurable resins can be used as the photocurable resin (polymerizable compound), it is preferable to use acrylic photocurable resins and derivatives thereof. Such an acrylic photocurable resin (and its derivatives) has good color developability, so that the color developability of the printed layer 2 to be formed can be further improved. Examples of monomers for acrylic photocurable resins and derivatives thereof include isobornyl acrylate, 4-hydroxybutyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, phenoxyethyl acrylate, isooctyl acrylate, stearyl acrylate, cyclohexyl acrylate, 2 -Ethoxyethyl acrylate, benzyl acrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobutyl acrylate, t-butyl acrylate , Tetrahydrofurfuryl acrylate, ethyl carbitol acrylate, 2,2,2-trifluoroethyl Acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl acrylate, methoxytriethylene glycol acrylate, PO-modified nonylphenol acrylate, EO-modified nonylphenol acrylate, EO-modified 2-ethylhexyl acrylate, phenyl Glycidyl ether acrylate, phenoxydiethylene glycol acrylate, EO-modified phenol acrylate, EO-modified cresol acrylate, methoxypolyethylene glycol acrylate, dipropylene glycol acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 2-n-butyl-2-ethyl- 1,3-propanediol diacrylate, tripropyleneglycol Diacrylate, tetraethylene glycol diacrylate, 1.9-nonanediol diacrylate, 1,4-butanediol diacrylate, bisphenol A EO modified diacrylate, 1.6-hexanediol diacrylate, polyethylene glycol 200 diacrylate, polyethylene Glycol 300 diacrylate, neopentyl glycol hydroxypiparate diacrylate, 2-ethyl-2-butyl-propanediol diacrylate, polyethylene glycol 400 diacrylate, polyethylene glycol 600 diacrylate, polypropylene glycol diacrylate, PO-modified bisphenol A diacrylate , EO-modified hydrogenated bisphenol A diacrylate, dipropylene glycol diacrylate Trimethylolpropane triacrylate, pentaerythritol triacrylate, trimethylolpropane EO-modified triacrylate, glycerin PO-added triacrylate, trisacryloyloxyethyl phosphate, pentaerythritol tetraacrylate, PO-modified trimethylolpropane triacrylate, tris (acryloxyethyl) ) Isocyanurate, 2- (2-vinyloxyethoxy) ethyl acrylate and the like. Among them, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane EO-modified triacrylate, pentaerythritol tetraacrylate, 2- (2-vinyloxyethoxy) acrylate Ethyl is preferred.

(Coloring agent)
The ink 2 ′ usually contains a colorant.

As the colorant, for example, various pigments, various dyes, and the like can be used, and a fluorescent material, a phosphorescent material, and the like can be used. However, the ink 2 ′ preferably includes a pigment as the colorant.
Thereby, the durability of the decorative sheet 100 can be particularly improved.

  When a plurality of types of inks 2 ′ are used, for example, inks 2 ′ corresponding to the three primary colors (cyan (blue purple), magenta (crimson purple), and yellow (yellow)) can be used.

  Thereby, the color reproduction range can be easily widened. In particular, when the reflected light is used for the appearance of the decorative sheet 100 using the light-shielding (light concealing) base material 1 such as a metal material, the decorative sheet 100 exhibits particularly excellent aesthetics.

  Further, for example, ink 2 ′ corresponding to the three primary colors of light (red (red), green (green), and blue (blue)) may be used.

  Thereby, the color reproduction range can be easily widened. In particular, when the transmitted light is used for the appearance of the decorative sheet 100 using the light-transmitting base material 1 or the like, the decorative sheet 100 exhibits particularly excellent aesthetics.

  Further, for example, the black ink 2 'may be used in combination with the chromatic ink 2'.

  Thereby, while suppressing the usage amount of the ink 2 ′, it is possible to obtain an effect such that a dark color can be suitably expressed or a tightened black can be expressed.

For example, white ink 2 ′ may be used.
Thereby, for example, even if the light concealability of the base material 1 or the like is relatively low, the contrast and visibility of the printed layer 2 by the chromatic ink 2 ′ are particularly improved, and the decorative sheet 100 is particularly excellent in aesthetics. Demonstrate.

  In particular, when using an indigo purple pigment ink exhibiting indigo purple (cyan), examples of the pigment constituting the ink include C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 2, and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Blue 60.

  When a reddish violet pigment ink exhibiting reddish purple (magenta) is used, examples of the pigment constituting the ink include C.I. I. Pigment violet 19, C.I. I. Pigment red 122, and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Violet 37.

  When a yellow pigment ink exhibiting yellow (yellow) is used, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 138, and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Yellow 139.

  When a red pigment ink exhibiting red (red) is used, C.I. I. Pigment red 177 and / or C.I. I. Pigment Red 254 is preferably used.

  When a green pigment ink exhibiting green (green) is used, C.I. I. Pigment green 36 and / or C.I. I. It is preferable to use CI Pigment Green 58.

  When a blue pigment ink exhibiting blue (blue) is used, C.I. I. Pigment Blue 15: 6 is preferably used.

  In addition, when a black pigment ink exhibiting black (black) is used, the pigment constituting the ink is selected from the group consisting of carbon black, iron black, manganese ferrite black, cobalt ferrite black, copper chrome black, and copper chrome manganese black. It is preferable to use one or more selected.

  In addition, when a white pigment ink exhibiting white (white) is used, the pigment constituting the ink includes titanium oxide, white lead, zinc white, lithopone, zinc sulfide, antimony oxide, calcium carbonate, kaolin, mica, barium sulfate. Alumina, talc, silica, calcium silicate, gloss white, white plastic pigment, and the like can be used.

(Other ingredients)
The ink 2 ′ may contain components other than those described above (other components). Examples of such components include photopolymerization initiators, slip agents (leveling agents), dispersants, polymerization accelerators, polymerization inhibitors, penetration enhancers, wetting agents (humectants), fixing agents, antifungal agents, Examples include antiseptics, antioxidants, chelating agents, thickeners, antifoaming agents, and sensitizers (sensitizing dyes).

  The photopolymerization initiator is not particularly limited as long as it is a compound that generates active species such as radicals and cations by light irradiation and initiates the polymerization reaction of the photocurable resin (polymerizable compound). As the photopolymerization initiator, a radical photopolymerization initiator or a cationic photopolymerization initiator can be used, but it is preferable to use a radical photopolymerization initiator. When using a photopolymerization initiator, the photopolymerization initiator preferably has an absorption peak in the ultraviolet region.

  Examples of the photo radical polymerization initiator include aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, Examples thereof include ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  Among these, at least one selected from an acylphosphine oxide compound and a thioxanthone compound is preferable from the viewpoint of solubility in a photocurable resin (polymerizable compound) and curability, and an acylphosphine oxide compound and a thioxanthone compound are used in combination. More preferably.

  Specific examples of the photo radical polymerization initiator include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine. , Carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) ) -2-Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethyl Oxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, bis (2,4,6-trimethylbenzoyl) -phenyl Phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, etc. 1 type or 2 types or more selected from these can be used in combination.

  The content of the photopolymerization initiator in the ink 2 'is preferably 0.5 wt% or more and 10 wt% or less. When the content of the photopolymerization initiator is within the above range, the ultraviolet curing rate is sufficiently high, and the photopolymerization initiator is hardly dissolved or colored due to the photopolymerization initiator.

  By including the slip agent in the ink 2 ′, the smoothness of the surface of the printing layer 2 is improved by the leveling action.

  The slip agent is not particularly limited. For example, a silicone-based surfactant such as polyester-modified silicone or polyether-modified silicone can be used, and polyether-modified polydimethylsiloxane or polyester-modified polydimethylsiloxane is preferably used. .

  Since the ink 2 ′ contains a dispersant, the dispersibility of the dispersoid such as a pigment is excellent, so that the storage stability and ejection stability of the ink 2 ′ can be particularly improved. The dispersant is not particularly limited, and examples thereof include polyoxyalkylene polyalkylene polyamines, vinyl polymers and copolymers, acrylic polymers and copolymers, polyesters, polyamides, polyimides, polyurethanes, amino polymers, silicon-containing polymers, and sulfur-containing polymers. , Fluorine-containing polymers, epoxy resins and the like.

  Further, the ink 2 ′ preferably does not contain an organic solvent that is removed (evaporated) in the manufacturing process of the decorative sheet 100. Thereby, generation | occurrence | production of the problem of a volatile organic compound (VOC) can be prevented effectively.

  The viscosity of the ink 2 'at room temperature (20 ° C) is preferably 20 mPa · s or less, and more preferably 3 mPa · s or more and 15 mPa · s or less. Thereby, the droplet discharge by an inkjet method can be performed more suitably.

<Hard layer forming composition>
Hereinafter, the hard layer forming composition used for forming the hard layer 3 will be described in detail.

  The composition for forming a hard layer used for forming the hard layer 3 includes a hard material constituting the hard layer 3 and / or a precursor thereof.

  As described above, examples of the constituent material of the hard layer 3 include melamine resin, vinyl chloride, phenol resin, and the like. In the following description, the hard layer 3 made of melamine resin is formed. The case will be mainly described.

(Hard material or its precursor)
The composition for forming a hard layer (hereinafter simply referred to as “first composition”) includes a hard material and / or a precursor thereof.

  In the case of forming the hard layer 3 composed of melamine resin, the first composition comprises a melamine resin and / or a precursor of melamine resin (monomer corresponding to melamine resin, oligomer (dimer, trimer, etc.). Including prepolymers).

  In this specification, the melamine resin refers to a resin containing a melamine compound and an aldehyde compound as constituent components.

  The melamine compound is a compound having a 1,3,5-triazine skeleton, in which three amino groups are introduced into the triazine ring.

  A preferable structure of the melamine compound includes, for example, a compound represented by the following formula (3).

（式（３）中、Ｒ^１、Ｒ^２およびＲ^３は、それぞれ独立に、水素原子または置換基を有していてもよい炭素数が１以上４以下の炭化水素基である。）

(In formula (3), R ¹ , R ² and R ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms which may have a substituent.)

As the melamine compound, a compound (melamine) in which R ¹ , R ² and R ³ in formula (3) are all hydrogen atoms is particularly preferable.

  Thereby, the hardness of the decorative sheet 100 can be further improved. Moreover, the synthesis | combination of the melamine type resin which comprises the decorative sheet 100 can be performed more efficiently.

  The aldehyde compound may be a compound having an aldehyde group (—CHO) in the molecule, and examples thereof include a compound represented by the following formula (2).

（式（２）中、Ｒは、水素原子または置換基を有していてもよい炭素数が１以上１０以下の炭化水素基である。）

(In the formula (2), R is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent.)

As the aldehyde compound, formaldehyde is particularly preferable.
Thereby, the hardness of the hard layer 3 can be improved more. In addition, the synthesis of the melamine resin can be performed more efficiently.

  The melamine-based resin may contain a melamine compound and an aldehyde compound as constituent components, but may further contain a guanamine compound as a constituent component in addition to the melamine compound and aldehyde compound.

  Thereby, the workability of the decorative sheet 100 can be particularly improved while sufficiently increasing the hardness of the hard layer 3.

  A guanamine compound is a compound having a 1,3,5-triazine skeleton, in which two amino groups are introduced into the triazine ring.

  A preferable structure of the guanamine compound includes, for example, a compound represented by the following formula (1).

（式（１）中、Ｒは、水素原子または置換基を有していてもよい炭素数が１以上１０以下の炭化水素基である。）

(In formula (1), R is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent.)

  As the guanamine compound, a compound (acetoguanamine) in which R in formula (1) is a methyl group is particularly preferable.

  Thereby, the hardness and workability of the decorative sheet 100 can be compatible at a higher level. Moreover, the synthesis | combination of the melamine type resin which comprises the decorative sheet 100 can be performed more efficiently.

  The reaction molar ratio of the aldehyde compound to the melamine compound ((molar amount of aldehyde compound) / (molar amount of melamine compound) is hereinafter simply referred to as “reaction molar ratio”). Although not particularly limited, it is preferably 1.0 or more and 4.0 or less, more preferably 1.0 or more and 2.0 or less, and further preferably 1.1 or more and 1.8 or less.

  If the reaction molar ratio is less than the lower limit value, the proportion of unreacted components remaining in the hard layer 3 to be formed tends to increase.

  Moreover, when the said upper limit is exceeded, the softness | flexibility of the hard layer 3 formed may become remarkably low.

  The melamine-based resin may contain components other than the components described above (melamine compounds, guanamine compounds, aldehyde compounds) as its constituent components.

  For example, the melamine resin preferably contains a sulfonamide compound as a constituent component.

  Thereby, the moisture resistance of the decorative sheet 100, antifouling property, durability, etc. can be improved especially.

As the sulfonamide compound, for example, p-toluenesulfonamide (CH ₃ —C ₆ H ₅ —SO ₂ NH ₂ ) or the like can be suitably used.

  Thereby, the moisture resistance, antifouling property, durability, etc. of the decorative sheet 100 can be further improved. Moreover, the synthesis | combination of the melamine type resin which comprises the decorative sheet 100 can be performed more efficiently.

  As the melamine resin, for example, a commercially available resin such as a melamine resin manufactured by Sumitomo Chemical Co., Ltd. can be used.

(solvent)
The first composition may contain a solvent. Thereby, for example, the hard material and its precursor can be dissolved and / or dispersed in the first composition, and the first composition can be easily handled (handleability). Can be made. As a result, the productivity of the decorative sheet 100 can be particularly improved.

  As the solvent contained in the first composition, a polar solvent can be preferably used. Specifically, water; alcoholic solvents such as methanol, ethanol, isopropanol; ketone solvents such as methyl ethyl ketone and acetone; Examples include amide solvents such as dimethylformamide (DMF); ether solvents such as tetrahydrofuran (THF) and tetrahydropyran; and sulfoxide solvents such as dimethyl sulfoxide (DMSO).

Among these, water is preferably used as the solvent.
Thereby, generation | occurrence | production of the problem of a volatile organic compound (VOC) at the time of manufacture of the decorative sheet 100 can be prevented effectively. Further, for example, when the first composition includes a precursor of a hard material, the precursor of the hard material can be uniformly dissolved in the first composition, and the hydrogen ion index (pH) is controlled. Therefore, it is possible to effectively prevent the occurrence of unintentional variations in the hydrogen ion exponent (pH) in the first composition. From such a thing, a polymerization reaction can be advanced suitably.

  When the first composition contains a solvent, the content of the solvent in the first composition is preferably 30% by mass or more and 95% by mass or less, and preferably 40% by mass or more and 70% by mass or less. More preferred.

(Other ingredients)
The first composition may contain components other than those described above (other components). Examples of such components include catalysts such as various acidic substances and various basic substances, mold release agents, polymerization initiators, slip agents (leveling agents), dispersants, polymerization accelerators, polymerization inhibitors, and penetration accelerators. , Wetting agents (humectants), colorants, fixing agents, antifungal agents, preservatives, antioxidants, chelating agents, thickeners, antifoaming agents, sensitizers (sensitizing dyes) and the like.

  As a basic substance as a catalyst, sodium hydroxide, potassium hydroxide, etc. are mentioned, for example.

  Examples of the acidic substance as a catalyst include latent acid catalysts such as acetic acid, hydrogen chloride, sulfuric acid, nitric acid, and diammonium imidodisulfonate.

When the first composition contains other components, the content of other components in the first composition (in the case of including a plurality of types of components, the sum of these contents) is 5.0% by mass. Or less, more preferably 0.1% by mass or more and 3.0% by mass or less.
Thereby, the function of the component as described above can be exhibited more effectively.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to embodiment mentioned above, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are contained in this invention.

  For example, the decorative sheet of the present invention is not limited to the form of the decorative sheet 100 shown in FIGS. 1 and 2, and has a configuration other than the base material 1, the printed layer 2, the hard layer 3, and the core material 4. Also good. For example, as shown in FIG. 4, it has the protective layer 5 in the outermost layer of the design surface side (surface side where the hard layer 3 of the base material 1 was provided), or as shown in FIG. You may have the support layer 6 in the outermost layer on the opposite side to a surface side (surface side of the side in which the hard layer 3 of the base material 1 was provided).

The protective layer 5 is not particularly limited, for example, a paper base having a basis weight of 10 g / m ² or more and 50 g / m ² or less, a melamine resin alone, or a melamine resin, aluminum hydroxide, magnesium hydroxide, Or it can obtain by impregnating the resin composition containing the inorganic filler chosen from silica, and drying this.

  In the present invention, the decorative sheet may have an intermediate layer between the base material and the core material.

  Further, the decorative sheet of the present invention may be manufactured by any method, and is not limited to the decorative sheet manufactured by the above-described method. For example, the order of each step in the embodiment of the manufacturing method described above may be changed.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

Example 1
[1] Production of decorative sheet First, an aluminum foil having a thickness of 40 μm (aluminum foil subjected to urethane primer treatment) was prepared as a base material.

  Next, an ink containing an ultraviolet curable resin (polymerizable compound) was applied to the aluminum base material in a predetermined pattern by an inkjet method. Thereafter, ultraviolet light having a peak wavelength of 350 to 400 nm was irradiated to polymerize and cure the ultraviolet curable resin (polymerizable compound), thereby forming a woodgrain printed layer (printing portion).

  As the ink, C.I. I. Indigo purple pigment ink containing CI Pigment Blue 15: 3, C.I. I. Crimson purple pigment ink containing CI Pigment Violet 19, C.I. I. A yellow pigment ink containing CI Pigment Yellow 150 and a black pigment ink containing carbon black as a pigment were used.

  Each ink is composed of phenoxyethyl acrylate, 2- (2-hydroxyethoxy) ethyl acrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, 4-hydroxybutyl as an ultraviolet curable resin (polymerizable compound). Acrylate, Irgacure 819 (manufactured by Ciba Japan) as a photopolymerization initiator, Speedcure TPO (manufactured by ACETO) as a photopolymerization initiator, Speedcure DETX (manufactured by Lambson) as a photopolymerization initiator, UV as a leveling agent -3500 (manufactured by Big Chemie) and p-methoxyphenol as a polymerization inhibitor. The viscosity of each ink at room temperature (20 ° C.) was in the range of 3 mPa · s to 15 mPa · s.

  Next, the hard layer forming composition (first composition) is applied to the surface of the base material on which the printed layer is formed as described above, and the hard layer is formed. A decorative sheet provided with a substrate, a printed layer, and a hard layer was obtained.

  As the first composition, a resin solid containing 100 parts of melamine resin obtained by condensation reaction of melamine (M) and formaldehyde (F) at a reaction molar ratio (F / M) = 1.7. Minute: 50% by mass of melamine resin varnish, thermal latent acid catalyst (“Catanit” manufactured by MRC Unitech): 0.9 part by mass, release agent (“Separ 328” manufactured by Chukyo Yushi Co., Ltd.): 0. A resin composition (varnish) obtained by adding 2 parts by mass and stirring at 23 ° C. for 10 minutes was used.

  Also, four types of decorative sheets having different printed layers were produced in the same manner as described above except that the printed layer pattern was changed. As a result, five different types of decorative sheets were obtained.

(Example 2)
Patterns different from each other in the same manner as in Example 1 except that a glass woven fabric (glass cloth) composed of T glass, having a basis weight of 150 g / m ² and a thickness (average thickness) of 250 μm was used as the substrate. 5 types of decorative sheets having the following printing layers were produced.

(Examples 3 to 6)
Except having changed the conditions of a base material as shown in Table 1, it carried out similarly to the said Example 1, and manufactured 5 types of decorative sheets which have a printing layer of a mutually different pattern.

(Example 7)
Except that the hard layer was made of polyester (thickness: 100 μm), five types of decorative sheets having printed layers with different patterns were produced in the same manner as in Example 1.

(Example 8)
The same as in Example 1 except that the core material composed of glass woven fabric (glass cloth) was joined to the surface opposite to the surface on which the printed layer and hard layer of the substrate were provided. Five decorative sheets having a printed layer of pattern were produced.

The glass woven fabric (glass cloth) used was composed of T glass, and had a basis weight of 100 g / m ² and a thickness (average thickness) of 100 μm.

  The base material and the glass woven fabric (core material) are joined with the glass woven fabric in contact with the surface opposite to the surface on which the printed layer and the hard layer are provided. The surface was pressed and heated with a pressing member under the conditions of heating temperature: 140 ° C., pressure: 5 MPa, and heating time: 30 minutes. As the pressing member, a member made of stainless steel and having a mirror finish was used.

Example 9
Five decorative sheets having printed layers with different patterns were produced in the same manner as in Example 7 except that a laminate obtained by laminating three kraft paper impregnated with a phenolic resin was used as the core material. The thickness of the core material was 600 μm.

(Examples 10 and 11)
Except having changed the conditions of a base material as shown in Table 1, it carried out similarly to the said Example 7, and produced 5 types of decorative sheets which have a printing layer of a mutually different pattern.

(Example 12)
Five types of decorative sheets having printing portions with different patterns were obtained in the same manner as in Example 1 except that an aluminum foil having a thickness of 15 μm (aluminum foil subjected to urethane-based primer treatment) was used as a substrate. Manufactured.

(Example 13)
Five types of decorative sheets having printing portions with different patterns were used in the same manner as in Example 1 except that an aluminum foil having a thickness of 8 μm (aluminum foil subjected to urethane-based primer treatment) was used as the base material. Manufactured.

(Comparative Example 1)
Except for using plain paper with a basis weight of 80 g / m ² as the base material, five types of decorative sheets having printed portions with different patterns were produced in the same manner as in Example 7.

(Comparative Example 2)
As the ink, the pigment used in Example 1, 1,2-hexanediol, trimethylolpropane, Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd.), triethanolamine, glycerin, and polyflow 401 ( Except for using a mixture of Nissin Chemical Industry Co., Ltd.) and ion-exchanged water, five types of decorative sheets having printed portions with different patterns were produced in the same manner as in Example 7. That is, in this comparative example, water-based ink not containing a photocurable resin (polymerizable compound) was used.

(Comparative Example 3)
As in the case of Example 7, except that the ink used was a mixture of the pigment used in Example 1 and diethylene glycol diethyl ether as an organic solvent (volatile component). A seed decorative sheet was produced. That is, in this comparative example, a solvent-based ink not containing a photocurable resin (polymerizable compound) was used.

(Comparative Example 4)
Except that the printing part was formed by gravure printing, five types of decorative sheets having printing parts with different patterns were produced in the same manner as in Example 7.

(Comparative Example 5)
Five types of decorative sheets having printed portions with different patterns were produced in the same manner as in Comparative Example 4 except that plain paper having a basis weight of 80 g / m ² was used as the substrate.
Table 1 summarizes the configurations of the decorative sheets of the examples and comparative examples.

[2] Evaluation The following evaluations were performed on the decorative sheets of Examples and Comparative Examples manufactured as described above.

[2.1] Productivity Productivity of a small amount and a wide variety when producing five types of decorative sheets was evaluated according to the following criteria.

A: The productivity of the decorative sheet is very excellent.
B: Productivity of the decorative sheet is excellent.
C: The productivity of the decorative sheet is good.
D: Productivity of the decorative sheet is slightly inferior.
E: Productivity of the decorative sheet is very inferior.

[2.2] Color developability The color developability of the printed portion when visually observed from the side of the decorative sheet provided with the hard layer was evaluated according to the following criteria.

A: The color developability of the printed part is very excellent.
B: The color developability of the printed part is excellent.
C: The color developability of the printed part is good.
D: The color developability of the printed part is slightly inferior.
E: The color developability of the printed part is very poor.

[2.3] Pattern shape The pattern shape of the printing part of the decorative sheet when visually observed from the side of the decorative sheet provided with the hard layer was evaluated according to the following criteria.

A: The printing part is provided in a desired shape, and no pattern disturbance is observed.
B: Almost no pattern disturbance is observed in the printed part.
C: Slight disturbance of the pattern in the printing part is recognized, but it is within the allowable range.
D: Disturbance of the pattern in the printing part is clearly recognized.
E: Pattern disturbance in the printed portion is noticeable.

[2.4] Hardness The Martens hardness of the surface of the decorative sheet on which the hard layer was provided was evaluated according to the following criteria.

A: Hardness is 300 MPa or more.
B: Hardness is less than 300 MPa.

[2.5] Adhesiveness The peeled state between the printed part and the base material layer when visually observed from the surface side of the decorative sheet on which the hard layer is provided is checked, and the base material and the print on the decorative sheet are observed according to the following criteria: The adhesion with the layer was evaluated.

A: No peeling occurs for any external stimulus.
B: Peeling occurred in heat shock and wet heat repeated tests.
C: Peeling occurred during tape peeling.
D: Peeling occurs when lightly rubbed with a finger.
E: Not closely attached.

[2.6] Heat resistance (nonflammability)
The amount of heat generated when the decorative sheet was subjected to a corn calorie burning test was measured, and the heat resistance (nonflammability) of the decorative sheet was evaluated according to the following criteria.

A: less than the amount of heat generated 8 MJ / ^{m 2,} and heat release rate of less than 65 kW / ^{m 2.}
B: amount of heat generation 8 MJ / ^{m 2} or less, and heating rate of 65 kW / ^{m 2} or more.
C: The calorific value is 8 MJ / m ² or more.

[2.7] Bending Workability The decorative sheet was subjected to external bending deformation at room temperature while visually observing from the surface side on which the hard layer was provided. The outer sheet was subjected to bending deformation until a crack occurred in the decorative sheet, and the bending workability of the decorative sheet was evaluated according to the following criteria by the minimum R shape immediately before the crack occurred in the decorative sheet.

A: Less than 2R.
B: 2R or more and less than 4R.
C: Less than 4R and less than 6R.
D: 6R or more and less than 8R.
E: 8R or more.
These results are summarized in Table 2.

As is apparent from Table 2, in the present invention, the color developability of the printed portion was excellent. Moreover, the unintentional disorder of the pattern of the printing layer (printing part) was prevented effectively, the desired pattern could be obtained, and the aesthetics of the decorative sheet were excellent. In addition, since the printing part is formed using the inkjet method, even if it is a plurality of types of decorative sheets having printing parts with different patterns, it is possible to manufacture with excellent productivity without the need to prepare a plate. It was. Moreover, in the decorative sheet of Examples 1-6 which does not have a core material, weight reduction and thickness reduction of the decorative sheet were able to be achieved, maintaining sufficient stiffness (tension).
On the other hand, in the comparative example, a satisfactory result was not obtained.

  According to the present invention, there is provided a decorative sheet having a base material made of an inorganic material, a printed layer, and a hard layer made of a hard material provided on the surface side of the base material provided with the printed layer. To do. In such a decorative sheet, since the printing layer is formed by applying an ink containing a photocurable resin by an ink jet method, it is possible to adjust the timing of light irradiation for curing the photocurable resin. The printed layer having the shape and pattern can be formed easily and reliably. Moreover, the decorative sheet in which the formed printing layer has the outstanding color development property and aesthetics can be provided. Therefore, the present invention has industrial applicability.

Claims (10)

A base material composed of an inorganic material selected from the group consisting of metals, metal compounds and carbon-based materials ;
A printed layer provided on the substrate and containing a cured product of a photocurable resin;
A decorative sheet comprising: a hard layer formed of a hard material having a surface Martens hardness of 300 MPa to 800 MPa , which is provided on a surface side of the substrate on which the printed layer is provided.   The decorative sheet according to claim 1, wherein the base material has a thickness of 10 μm to 300 μm.   The decorative sheet according to claim 1 or 2, wherein the substrate is made of a metal material. The decorative sheet according to any one of claims 1 to 3 , wherein the hard layer is made of a material containing a melamine-based resin. The decorative sheet according to any one of claims 1 to 4 , further comprising a core material provided on a surface of the base material opposite to the printed layer. The decorative sheet according to claim 5 , wherein the core material is made of glass cloth. A step of applying by an inkjet method an ink containing a photo-curable resin to the metal, metal compound and base is an inorganic material material selected from the group consisting of carbon-based material,
Curing the photocurable resin to form a printed layer; and
Forming a hard layer having a surface Martens hardness of 300 MPa or more and 800 MPa or less on the surface side of the substrate on which the printed layer is provided. The method for manufacturing a decorative sheet according to claim 7 , further comprising a step of bonding a core material to a surface of the base material opposite to the printed layer. The method for manufacturing a decorative sheet according to claim 8 , wherein the step of bonding the core material is performed after the step of curing the photocurable resin. The method for producing a decorative sheet according to claim 8 or 9 , wherein the photocurable resin is an ultraviolet curable resin.

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