JP2012041390A - Ink for forming mat layer, and mat decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink for forming a mat layer, which is used to form the mat layer providing a mat surface on which a fingerprint is hardly left even if a human touches, and from which a left fingerprint is easily removed.SOLUTION: The ink for forming the mat layer is used to form the mat layer of a mat decorative sheet that provides the mat surface to decorative goods, and contains an organic solvent, a thermosetting resin as a binder, and particles as a matting agent. The matting agent contains two of particles, that have a difference of 1.5 μm or more in an average particle size, among various particles having the average particle size of 2-20 μm.

Description

  The present invention relates to an ink for forming a mat layer, which is used to form a mat layer that provides a mat surface to an article to be decorated.

  When a matte appearance is required for an article, fine irregularities are formed on the surface of the article. For example, a mat layer that forms fine irregularities on the surface is fixed to the surface of the article. A surface that has been matted due to the formation of fine irregularities is referred to as a “matte surface”.

  A method of protecting or decorating the surface of an article such as a plastic part or an exterior product using a decorative sheet has been conventionally known. A decorating sheet is the structure by which the decorating layer was provided on the surface of the base sheet which is a support body. The decorative sheet is fixed to the surface of the article together with the decorative layer. The decorative layer has visual effects such as colors and designs, and provides a protective coating or a decorative coating on the surface of the article.

  Matting is also a kind of decorative layer because matting is also a visual effect. When the mat layer is positioned on the outermost side of the decorative layer, the mat surface can be provided on the surface of the article using the decorative sheet. In this specification, regarding the arrangement of the decorative sheet, the side of the article to be decorated is referred to as the inside, and the viewer's side is referred to as the outside.

  Patent Document 1 describes a mat decorative sheet having a base sheet and a mat layer formed on the surface of the base sheet. The mat layer is made of a mat coating agent containing a two-component curable resin and a matting agent. This mat decorating sheet is fixed to the surface of a decorative article such as a molded product so that the mat layer is positioned on the outermost side, and as a result, a matte surface is provided to the decorative article.

  However, since there are fine irregularities on the mat surface, a fingerprint is likely to adhere when touched by a person, and once the fingerprint is attached, it is difficult to remove. Therefore, a decorative article having a matte surface has a problem that the aesthetic appearance is easily impaired when it is touched by a human hand while being displayed as a product or during use.

  Patent Document 2 describes a transparent reflective film having a fine structure (preferably a large number of prisms) on the surface. The fine structures are arranged in a regular pattern, and the shape, height, and distribution density are controlled. As a result, a surface reflection division region is formed and the surface reflection can be divided in the plane direction of the fine structure, so that strong specular reflection from a smooth surface in a specific direction can be suppressed. As a result, even if dirt such as fingerprints adheres to the surface of the optical film, the dirt can be made inconspicuous, the deterioration of display performance is suppressed, and the visibility is improved.

  Patent Document 3 describes a matte coating film and a matte coating composition that can be easily removed even if dirt is attached without causing glossiness due to scratches. This matting paint composition contains two kinds of matting agents: matting agent (A) and matting agent (B). And the average particle diameter of a matting agent (A) is smaller than the average particle diameter of a matting agent (B).

  With regard to the removal of dirt, specifically, a problem has been pointed out that dirt adheres to large concave and convex recesses and cannot be removed, thereby impairing the merchantability. Further, in an experiment for evaluating the stain removability of the coating film, a mixture of carbon and water is used as a stain model.

  Then, the dirt here means dirt which has fluidity, enters into the gap, and then dries and adheres like mud. Oily dirt such as fingerprints attached when touched by a person is not recognized as a problem.

  In addition, as shown in the description of the mechanism to which the dirt adheres, the technique of Patent Document 3 aims to shallow the concave portions of the surface unevenness of the matte coating film. That is, in the matte coating film of Patent Document 3, the matting agent (A) having a small average particle diameter enters between the matting agent (B) having a large average particle diameter and fills the recesses on the surface of the coating film. It functions as (FIG. 1). Therefore, the unevenness formed on the matte surface becomes shallow, and the matte effect is insufficient.

  Further, in Patent Document 3, organic materials such as protein particles and acrylic resin particles are used as a matting agent, and the stability and durability of the matting effect are insufficient.

JP2007-290389A JP 2004-361835 A JP-A-2005-298686

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to form a mat layer that provides a mat surface that makes it difficult for fingerprints to adhere even if a person touches them, and to remove attached fingerprints easily. An object of the present invention is to provide an ink for forming a mat layer.

  In this specification, a characteristic that fingerprints are difficult to adhere even when touched by a person and the attached fingerprints are easily removed is referred to as fingerprint resistance.

The present invention is used to form a mat layer of a mat decorative sheet that provides a mat surface to a decorative article, and includes an organic solvent, a thermosetting resin as a binder, and particles as a mat agent. Ink,
The mat agent provides an ink for forming a mat layer, which contains two kinds of particles having a difference of 1.5 μm or more in average particle diameter among various particles having an average particle diameter of 2 to 20 μm.

  In one certain form, the larger particle having the larger average particle size of the two types of particles has an amount of 20 to 60% by weight in the matting agent, and the average particle size of the two types of particles is small. The smaller particles are contained in the matting agent in an amount of 40 to 80% by weight.

  In one certain form, the said mat agent consists of said 2 types of particle | grains.

In one certain form, the average BET specific surface area of the said mat agent is 230-500 m < ² > / g.

  In one certain form, the two types of particles have a difference in specific gravity within 0.2.

  In one certain form, the said particle | grain is a silica particle or a carbon black particle.

  Further, the present invention provides a mat decorative sheet having a decorative layer on the surface of the base sheet, wherein the outermost decorative layer is a mat layer, and the mat layer is any one of the above mat layers. Provided is a mat decorative sheet that is formed from a forming ink.

  In one certain form, the thickness of the said mat | matte layer is 0.5-8.0 micrometers.

  The present invention also provides a decorative article having a mat surface formed by using any one of the above mat layer forming inks.

  The present invention also provides a decorative article having a mat surface formed using any one of the above mat decorating sheets.

  The ink for forming a mat layer of the present invention includes small particles and large particles uniformly dispersed as a mat agent. Therefore, the mat layer formed from the mat layer forming ink of the present invention has uneven irregularities on the surface. Therefore, the matte surface formed from the mat layer forming ink of the present invention has excellent fingerprint resistance.

It is sectional drawing which shows the structure of the mat decorating sheet which is one Embodiment of this invention. It is sectional drawing which shows the structure of the decorative article which has the mat | matte surface which is one Embodiment of this invention. It is a model expanded sectional view of the mat surface of this invention.

Matt Decorating Sheet FIG. 1 is a cross-sectional view schematically showing the structure of a mat decorating sheet 5 according to an embodiment of the present invention. A mat layer 2 is provided on one surface of the base sheet 1, and a colored layer 3 and an adhesive layer 4 are provided on the other surface.

  The base sheet 1 is a sheet material or a film material that is conventionally used for applications in which a decorative layer or the like is supported on a sheet. Film material refers to a sheet material made of synthetic resin. The synthetic resin is at least one selected from the group consisting of polycarbonate resins, polyamide resins, polyimide resins, polyester resins, acrylic resins, olefin resins, urethane resins, and acrylonitrile butadiene styrene resins. The synthetic resin is preferably mentioned.

  As the base sheet, a single-layer sheet formed from the above-mentioned synthetic resin, a laminated sheet in which two or more single-layer sheets are laminated (the material composition of each single-layer sheet may be a synthetic resin selected from the above group). And may be the same or different), and may be a copolymer sheet using the above synthetic resin.

  The thickness of the base sheet is preferably 5 to 500 μm. When the thickness of the base sheet is 5 μm or more, when the decorative sheet is fixed to the article to be decorated, the handling property when the decorative sheet is placed in the mold can be more sufficiently secured. Further, when the thickness of the base sheet is 500 μm or less, an appropriate rigidity can be obtained, and handling properties can be more sufficiently ensured.

  The surface of the base sheet may be surface-treated so that the printability is good. However, in the use of the mat decorative sheet, the base sheet is not peeled off alone. Therefore, the surface of the base sheet does not need to exhibit releasability and does not need to be surface-treated to impart releasability.

  The mat layer 2 is a layer that provides a mat surface. The mat layer 2 may be formed on a part of the surface of the base sheet. By partially forming the mat layer 2, it is possible to express the combination of the glossy surface and the mat surface. The mat layer 2 is located on the outermost side among the decorative layers of the mat decorative sheet.

  As the mat layer 2, for example, an amino alkyd resin, a urea melamine resin, or a mixture thereof may be used as a main component and particles containing particles as a mat agent may be used.

  The mat layer forming ink for forming the mat layer 2 uses an organic solvent, a thermosetting resin as a binder, and a composition containing particles as a mat agent. The mat layer forming ink is preferably an ink composition capable of gravure printing.

  The organic solvent is not particularly limited as long as it is of a type conventionally used for gravure printing ink. Examples include methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), ethyl acetate, butyl acetate, benzene, toluene, xylene, cyclohexanone, isopropyl alcohol (IPA), methanol, ethanol, and the like.

  Examples of thermosetting resins include a resin composition in which 5-40% by weight of a resin obtained by addition condensation of formaldehyde is added to a non-drying oil-modified alkyd having amino groups such as urea, melamine, guanamine, and aniline. Or a resin obtained by co-condensation reaction of a mixture of melamine and urea with formaldehyde, a resin that is a mixture of an epoxy resin and a melamine resin, and the like.

  The particles must be insoluble and hard. The mat layer forming ink contains an organic solvent for printing ink. Further, the mat layer is heated and pressurized in the bonding step or the like. For this reason, if the particles are inferior in solvent resistance, heat resistance or pressure resistance, the matte effect is impaired. Therefore, the particles are preferably made of an inorganic material.

  Specific examples of such particles include silica particles and carbon black particles. What is necessary is just to use what is obtained, for example with quartz, silicic acid anhydride, etc. as a silica particle. As the carbon black particles, for example, those obtained by a combination of thermal decomposition and incomplete combustion of hydrocarbons such as natural gas, petroleum, and creosote oil may be used. Silica particles are particularly preferred as the particles from the viewpoints of swelling with a solvent, shape stability, heat resistance during molding, and the like.

  The particles as the matting agent include at least two types of particles. Here, the types of particles are distinguished based on particle products available on the market. For example, among the particle products marketed as matting agents, the particle products having some characteristic values are different types of particles.

  The two types of particles (particle products) are selected from particles (particle products) having an average particle diameter of 2 to 20 μm. If the average particle size of any one of the particles is less than 2 μm, the mat feeling of the mat surface becomes insufficient, and if it exceeds 20 μm, a problem occurs in printability.

  In addition, the average particle diameter here means the median diameter (D50) which is a 50% average diameter of cumulative particle volume. The average particle diameter can be measured using a laser diffraction / scattering particle size distribution analyzer (for example, “LS13 320” manufactured by Beckman Coulter, Inc.).

  The two types of particles preferably have an average particle size difference of 1.5 μm or more. By doing so, the mat layer formed from the mat layer forming ink has irregularities on the surface. As a result, irregularities with irregular depths or heights are formed on the mat surface of the article to be decorated, which improves fingerprint resistance. Conversely, even if there are two or more types of particles, if the difference in average particle diameter is less than 1.5 μm, there is a tendency that there is no difference in the depth of the surface or the height of the printed surface. Fingerprint resistance of the mat surface formed using the layer forming ink may be insufficient.

  In a preferred embodiment, the difference between the average particle sizes of the two types of particles is 1.5 μm or more, more preferably 1.7 μm or more, and even more preferably 2.0 μm or more.

  Of the two types of particles, the larger particle having the larger average particle size is contained in the matting agent in an amount of 20 to 60% by weight, preferably 25 to 55% by weight, more preferably 30 to 50% by weight. When the content of the large particles is less than 20% by weight, the matte feeling is insufficient, and when it exceeds 60% by weight, the viscosity of the applied ink is remarkably increased, and the printability becomes unsuitable.

  Of the two types of particles, the smaller particle having the smaller average particle size is contained in the matting agent in an amount of 40 to 80% by weight, preferably 45 to 75% by weight, more preferably 50 to 70% by weight. When the content of the small particles is less than 40% by weight, the fingerprint resistance is insufficient, and when it exceeds 80% by weight, the fingerprint resistance is insufficient.

  In a preferred embodiment, the average particle size of the large particles is 5 to 20 μm, preferably 6 to 18 μm, more preferably 7 to 15 μm. The average particle size of the small particles is 2 to 5 μm, preferably 3 to 4 μm.

  The matting agent may be composed of large particles and small particles without containing other components. In that case, the mixing ratio of the large particles and the small particles is 20/80 to 60/40, preferably 25/75 to 55/45, more preferably 30/70 to 50/50 by weight.

  When the mixing ratio of large particles to small particles is less than 20/80, the matte feeling is insufficient, and when it exceeds 60/40, the fingerprint resistance is insufficient.

The large particles and the small particles each independently have a BET specific surface area of 100 to 500 m ² / g, preferably 200 to 400 m ² / g, more preferably 250 to 350 m ² / g. When the BET specific surface area of the large particles or the small particles is less than 50 m ² / g, the matting agent easily settles. On the other hand, if the average BET specific surface area of the large particles or small particles is too low, the particles easily fall off from the binder, and the wear resistance of the mat surface decreases. When the BET specific surface area of large particles or small particles exceeds 500 m ² / g, the matting agents aggregate and become difficult to redisperse.

  In addition, a BET specific surface area can be determined by the test method prescribed | regulated to JISZ8830.

  The large particles have a specific gravity of 0.1 to 1, preferably 0.15 to 0.5, more preferably 0.2 to 0.4. When the specific gravity of the large particles is less than 0.1, it is difficult to disperse in the ink, and when it exceeds 1, silica does not disperse but settles in the ink.

  The small particles have a specific gravity of 0.1 to 1, preferably 0.15 to 0.5, more preferably 0.2 to 0.4. When the specific gravity of the small particles is less than 0.1, it is difficult to disperse in the ink.

  A smaller specific gravity difference between large particles and small particles is preferred. The specific gravity difference between the two kinds of particles is within 0.3, preferably within 0.2, and more preferably within 0.15. If the specific gravity difference between the two types of particles exceeds 0.3, the dispersibility in the ink becomes unstable.

The matting agent containing two kinds of particles has an average BET specific surface area of 230 to 500 m ² / g, preferably 240 to 450 m ² / g, more preferably 250 to 400 m ² / g. When the average BET specific surface area of the matting agent is less than 230 m ² / g, the matting agent is precipitated. On the other hand, if the average BET specific surface area of the matting agent is too low, the matting agent is easily removed from the binder, and the wear resistance of the matting surface is lowered. When the average BET specific surface area of the matting agent exceeds 500 m ² / g, the matting agents aggregate and are difficult to redisperse.

  The average BET specific surface area of the matting agent is calculated by weighted averaging the BET specific surface area of the particles contained in the matting agent according to the content ratio (weight ratio) of each particle.

  The amount of matting agent in the mat ink or mat paint is typically 0.5-20% by weight, preferably 1-10% by weight, more preferably 3-8% by weight, based on solids. Contained. If the content of the matting agent is too small, a good matte decoration cannot be obtained. If the content is too large, the matting agent settles and aggregates in the ink, which adversely affects printability.

  In order to provide the mat layer 2 on the surface of the base sheet 1, a normal printing method such as an offset printing method, a gravure printing method, or a screen printing method may be used. Among these, it is preferable to use a gravure printing method in order to efficiently form a high quality pattern.

  The thickness of the mat layer 2 is 0.1 μm to 50 μm. If it is less than 0.1 μm, the base sheet 1 is stretched when it is molded into a two-dimensional or three-dimensional shape or decorated simultaneously, so that the mat layer may be sheared at that portion. May cause loss of matte feeling. On the other hand, if the thickness exceeds 50 μm, when the two-dimensional or three-dimensional shape is formed or simultaneously decorated, the mat layer itself cannot crack and the crack is generated in the mat layer itself. The thickness of the mat layer is more preferably 0.5 to 30 μm, still more preferably 1 to 20 μm.

  The colored layer 3 is a layer for concealing the background color of the decorated article and coloring the decorated article. The colored layer 3 may be arranged at any position that is not the outermost side in the decorative layer of the mat decorative sheet. If necessary, the colored layer 3 may be disposed alternatively or additionally between the base sheet 1 and the mat layer 2. The colored layer 3 is formed by spreading ink or paint on the surface of the base sheet.

  Synthetic resins that serve as binders for the colored layer include polyvinyl resins, polyamide resins, polyester resins, acrylic resins, polyurethane resins, polyvinyl acetal resins, polyester urethane resins, cellulose ester resins, alkyd resins, and chlorides. At least selected from the group consisting of vinyl vinyl acetate copolymer resins, thermoplastic urethane resins, methacrylic resins, acrylic ester resins, chlorinated rubber resins, polyethylene chloride resins, and chlorinated polypropylene resins One synthetic resin is preferred.

  Examples of the colorant for the colored layer include pigments and dyes. As the colorant for the colored layer, those conventionally used for coloring decorative sheets are used. Specific examples of preferable colorants include (1) plant pigments such as indigo, alizarin, carsamine, anthocyanins, flavonoids, shikonin, (2) food pigments such as azo, xanthene, triphenylmethane, (3) loess, green soil, etc. Natural inorganic pigments, (4) inorganic pigments such as acrylic and urethane, and (5) calcium carbonate, titanium oxide, aluminum lake, mudder lake, and cochineal lake.

  In order to form a colored layer, a high-brightness ink layer made of an ink having a mirror-like metallic luster (hereinafter referred to as a high-brightness ink) in which metal thin film pieces are dispersed in a binder resin may be used. It is preferable that content with respect to the non volatile matter in the ink of a metal thin film piece is the range of 3-60 mass%. High brightness ink using metal thin film strips as a pigment, when the ink is printed or applied, the metal thin film strips are oriented in a direction parallel to the surface of the object, resulting in a high-brightness mirror-like metallic luster. can get.

  The adhesive layer 4 is formed on a portion of the inner surface of the decorative sheet that is to be adhered to the article to be decorated. That is, when it is desired to bond the entire inner surface to the article to be decorated, an adhesive layer is formed on the entire surface. Moreover, when it is desired to adhere a part of the inner surface to the article to be decorated, an adhesive layer is formed on a part thereof.

  The constituent material of the adhesive layer is not particularly limited as long as sufficient adhesiveness to the article to be decorated can be obtained. When the adhesive layer is thermocompression bonded to the article to be decorated, a synthetic resin having heat sensitivity and pressure sensitivity may be appropriately selected as a constituent material of the adhesive layer.

  For example, when the constituent material of the surface portion of the article to be decorated is a polyacrylic resin, it is preferable to use a polyacrylic resin as the constituent material of the adhesive layer. For example, when the constituent material of the surface portion of the article to be decorated is a polyphenylene oxide copolymer, a polystyrene copolymer resin, a polycarbonate resin, a styrene resin, or a polystyrene blend resin, The polyacrylic resin, polystyrene resin, polyamide resin and the like having an affinity for these resins may be appropriately selected and employed.

  Further, for example, when the constituent material of the surface portion of the article to be decorated is a polypropylene resin, the constituent materials of the adhesive layer are chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, coumarone Indene resin can be used.

  The thickness of the adhesive layer is preferably 0.5 μm to 50 μm. When the thickness of the adhesive layer is 0.5 μm or more, sufficient adhesion can be obtained more easily and reliably. When the thickness of the adhesive layer is 50 μm or less, the preferred mat layer 2 that is easy to dry after fixing the decorative sheet to the article to be decorated is located on the outermost side among the decorative layers of the mat decorative sheet.

  Although not shown, the mat transfer sheet may have a hard coat layer, a design layer, an anchor layer, a metal thin film, and the like as required.

  For example, the hard coat layer is disposed inside the mat layer as necessary. The hard coat layer is a layer having a certain level of hardness in order to protect the decorative layer and the object to be decorated.

  As the hard coat layer, an energy crosslinkable resin that crosslinks or cures when energy such as heat, ultraviolet rays, or an electron beam is applied is used. Examples of the material of the hard coat layer include ionizing radiation curable resins such as cyanoacrylate and urethane acrylate, and thermosetting resins such as acrylic and urethane, but are not particularly limited. Preferably, the energy crosslinkable resin is an active energy ray crosslinkable resin that is crosslinked by applying an ultraviolet ray or an electron beam. This is because the active energy ray resin can easily adjust the degree of crosslinking by increasing or decreasing the amount of energy applied.

  As a method for forming the hard coat layer, there are a coating method such as a gravure coating method, a roll coating method, a comma coating method and a lip coating method, a printing method such as a gravure printing method and a screen printing method. The thickness of the hard coat layer is 0.3 μm to 50 μm. If it is less than 0.3 μm, sufficient surface hardness cannot be obtained. The protective function of the article surface cannot be maintained. On the other hand, if it exceeds 50 μm, sufficient transparency of the hard coat layer cannot be obtained, and the decorative function from the colored layer is impaired. A more preferable thickness of the hard coat layer is 2 to 10 μm.

  The hard coat layer is preferably crosslinked after being formed. This is because the printability of the mat layer forming ink is improved. The degree of cross-linking may be completely cross-linked, or may be limited to a minimum degree of partial cross-linking that provides good printability of the mat layer forming ink. When partially cross-linking, it is preferable that the hard coat layer is completely cross-linked after being fixed to the article to be decorated.

  The design layer is a layer showing characters or pictures. The components and forming method of the pattern layer are the same as those of the colored layer except that the pattern layer is formed in a pattern according to the pattern.

  Of the layers constituting the mat decorating sheet, each resin layer can be formed by the same method as before unless otherwise specified. Examples of conventional layer forming methods include gravure coating methods, roll coating methods, comma coating methods and other printing methods using gravure coating methods, roll coating methods, comma coating methods, gravure printing methods, screen printing methods, etc. There is.

Method for Providing Matt Surface on Decorated Article Using the mat decorating sheet of the present invention, a mat surface can be provided on the surface of the decorated article by a method such as hot roll bonding or in-mold molding. For example, in hot roll bonding, the mat decorating sheet is placed on the surface of the matte decorative sheet on the surface of the article to be decorated, using a transfer machine such as a roll transfer machine or an up-down transfer machine. Heat and pressure are applied from the mat layer side (outside). By doing so, the inside of the mat decorating sheet is adhered to the surface of the article to be decorated, and the mat surface is fixed to the surface of the article to be decorated.

  In in-mold injection molding, first, a mat decorative sheet is fed into a molding die. At that time, the mat decorative sheet is oriented so that the mat layer side (outside) faces the mold cavity surface.

  Next, the mold is closed, and the molten resin is in contact with the adhesive layer side (inside) surface of the mat decorative sheet, that is, the molten resin so that the mat decorative sheet is sandwiched between the molten resin and the mold cavity surface. Is filled into the mold cavity. As a result, the molten resin is molded, and at the same time, the mat decorative sheet is bonded to the surface of the injection molded body. When the resin is cooled, the mold is opened, and the injection molded body is taken out, the mat surface is fixed to the surface of the injection molded body.

Decorative article having mat surface By the above-described method for providing a mat surface, a decorated article having the mat decorating sheet of the present invention fixed to an article to be decorated is obtained. FIG. 2 is a cross-sectional view showing the structure of a decorated article according to an embodiment of the present invention. In the decorated article, the mat decoration sheet 5 is fixed to the article to be decorated 10.

  The article to be decorated is not particularly limited as long as it is an article having a surface that can be decorated using a decorative sheet. From the viewpoint of exhibiting the fingerprint resistance of the matte surface, a product or a part whose surface is touched by a human hand in a normal usage pattern is preferable. For example, a main body cover of a mobile phone, a main body cover of a notebook personal computer, a main body cover of a media player, and the like.

  The ink for forming a mat layer of the present invention includes small particles and large particles uniformly dispersed as a mat agent. Therefore, the mat layer formed from the mat layer forming ink of the present invention has uneven irregularities on the surface. As a result, there are many irregularities on the mat surface of the decorative article.

  FIG. 3 is a schematic enlarged sectional view of the mat surface of the present invention. A large number of fine irregularities are formed on the mat surface 301. The unevenness of the mat surface 301 is uneven in depth or height. Further, the interval S (pitch) of the unevenness of the mat surface 301, that is, the length of the average line 302 corresponding to one peak and one valley adjacent thereto is irregular.

  The arithmetic average roughness Ra (JIS B-0601 (1994)) of the mat surface is 0.05 to 1.5 μm, preferably 0.1 to 1.0 μm, more preferably 0.2 to 0.8 μm. When Ra is less than 0.05 μm, the matte appearance of the matte surface is insufficient, and when it exceeds 1.5 μm, the unevenness tends to be worn.

  The unevenness of the mat surface is uneven in depth or height. When the depth or height of the unevenness is almost constant or the pitch of the unevenness is almost regular (constant), the anti-fingerprint property of the mat surface is lowered and the matting effect is also reduced.

  For example, the degree of unevenness of the height or depth of the unevenness can be expressed by how far the height or depth value of the individual unevenness is from the average value thereof. Here, it is assumed that the arithmetic average roughness Ra value of the mat surface of the present invention, which is measured with a reference length l of 10 mm, is 1.

  In this case, the mat surface of the present invention has 7 to 100, preferably 10 to 50, more preferably 10 to 50 convex portions having a height from the average line 302 exceeding 2.0 in the reference length l. There are 15-40. In addition, preferably, in addition to this, in the reference length l, there are 7 to 100, preferably 10 to 50, more preferably 15 to 15 recesses whose depth from the average line 302 exceeds 2.0. There are 40.

  In this case, the maximum height Ry (maximum amplitude centered on the average line 302) in the reference length l is preferably about 1 to 20 μm, preferably about 2 to 15 μm, more preferably about 4 to 10 μm. is there. Further, the minimum amplitude around the average line 302 in the reference length l is about 0.1 to 10 μm, preferably about 1 to 6 μm, more preferably about 2 to 5 μm.

  In this case, preferably, the minimum value of the uneven pitch in the reference length l is about 0.1 to 1 μm, preferably about 0.2 to 0.8 μm, more preferably about 0.3 to 0.7 μm. It is. In addition, the maximum value of the uneven pitch in the reference length l is about 1 to 10 μm, preferably about 2 to 8 μm, and more preferably about 2.5 to 5 μm.

  The present invention will be specifically described by the following examples, but the present invention is not limited thereto. In the examples, the amount represented by “part” or “%” is based on weight unless otherwise specified.

Examples 1-6 and Comparative Examples 1-5
A biaxially stretched polyethylene terephthalate film having a width of 650 mm and a thickness of 38 × 10 ⁻³ mm (38 μm) was used as a base sheet. On one surface of this base sheet, a mat ink in which silica particles were added as a matting agent was printed on a mixture of an aminoalkyd resin and an acrylic resin using a gravure printing method to form a mat layer. The dry thickness of the mat layer was 2 μm. The composition of the mat ink is as follows.

  The following types of silica particles were prepared and used as matting agents in combination as shown in Table 3. The BET specific surface area of the matting agent was determined by analyzing according to JISZ8830.

  Next, three colored layers were stacked and printed on the other surface of the base sheet. As the printing ink for forming each layer, an acrylic resin added with 3.0% by weight of titanium oxide was used. Printing was performed using a gravure printing method.

After all the colored layers are dried, an acrylic resin is coated with a gravure printing method so that the entire surface of the laminated sheet including the innermost colored layer is covered with a thickness of 1 × 10 ⁻³ mm (1 μm). An adhesive layer was formed.

  When the obtained decorative sheet was adhered to a transparent acrylic plate, a matte mat surface was provided on the surface of the transparent acrylic plate.

Measurement of surface roughness Using a surface roughness measuring instrument “Surfcom 1500SD” manufactured by Tokyo Seimitsu Co., Ltd., the method according to JIS B-0601 (reference length l = 10 mm) was used to measure the depth and height of irregularities, The arithmetic average roughness Ra and the maximum height Ry of the mat surface were determined. The results are shown in Table 3.

Evaluation of fingerprint resistance (1) Ease of fingerprint removal:
The test was conducted in accordance with the fingerprint removability test method described in JIS K2246. Note that whether or not the fingerprint was removed was determined by visually observing the appearance of the portion of the test piece to which the artificial fingerprint liquid was attached, separated by 20 cm under a three-wavelength light source. The results are shown in Table 3.

Evaluation criteria

(2) Fingerprint adhesion difficulty:
A finger was brought into contact with the surface of the transfer product a plurality of times, and it was tested how many times the fingerprint adhered to the surface of the transfer product. Judgment as to whether or not the fingerprints were attached was made by visually observing the appearance of the part of the test piece in contact with the finger under a three-wavelength light source by 20 cm. The results are shown in Table 3.

Evaluation criteria

Measurement of Surface Gloss Using a Nippon Denshoku gloss meter “PG-1M”, the glossiness of the matte surface was measured by a method according to JIS Z-8741. The results are shown in Table 3.

Evaluation criteria

Evaluation of mat surface durability The wear resistance of the mat surface was tested in accordance with a wear test method using a wear ring described in JIS K7204. The determination was made by visually observing whether an area of 1 mm × 1 mm or more was scraped off in the worn part. The results are shown in Table 3.

Evaluation criteria

1 ... Base sheet,
2 ... Matte layer,
3 ... colored layer,
4 ... adhesive layer,
5 ... Matt decorative sheet,
10 ... Decorative article,
301 ... Matte surface,
302: Average line.

Claims (10)

An ink for forming a mat layer, which is used to form a mat layer of a mat decorative sheet that provides a mat surface to a decorative article, and includes an organic solvent, a thermosetting resin as a binder, and particles as a mat agent. ,
The matting agent is an ink for forming a matte layer, which contains two kinds of particles having a difference of 1.5 μm or more in average particle diameter among various particles having an average particle diameter of 2 to 20 μm.   Among the two types of particles, the larger particles having the larger average particle size are in the amount of 20 to 60% by weight in the matting agent, and the smaller particles having the smaller average particle size are the mats. The mat layer forming ink according to claim 1, which is contained in the agent in an amount of 40 to 80% by weight.   The mat layer forming ink according to claim 1 or 2, wherein the mat agent comprises the two kinds of particles. It said mat layer forming ink according to claim 1 Average BET specific surface area of the matting agent is 230~500m ² / g.   The ink for forming a mat layer according to any one of claims 1 to 4, wherein the two kinds of particles have a difference in specific gravity within 0.2.   The mat layer forming ink according to any one of claims 1 to 5, wherein the particles are silica particles or carbon black particles.   It is a mat decorating sheet which has a decorating layer on the surface of a base sheet, and the decorating layer located on the outermost side is a mat layer, and the mat layer is any one of claims 1 to 6. A mat decorative sheet formed from the mat layer forming ink.   The mat decorating sheet according to claim 7, wherein the mat layer has a thickness of 0.5 to 8.0 μm.   A decorative article having a mat surface formed using the mat layer forming ink according to any one of claims 1 to 6.   A decorative article having a mat surface formed using the mat decorating sheet according to claim 7.

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