Patent Description:
Conventionally, antiviral "interior finishing decorative sheets" are known that contain a silver-based inorganic additive or a zinc-based inorganic additive in a resin coating at the outermost surface thereof (see paragraph [<NUM>] and <FIG> of PTL <NUM>).

The conventional silver-based inorganic additive or zinc-based inorganic additive has a true specific gravity of <NUM> or less and an average particle diameter of <NUM> or less, and is contained in the resin coating at a solid content ratio of <NUM> to <NUM>%.

<CIT> describes an antibacterial decorative material which is produced by forming a pattern layer on a base material sheet comprising paper, plastic or the like by printing and forming an antibacterial protective layer on the pattern layer by gravure coater or the like using an ionizing radiation curable resin containing an inorganic antibacterial agent and a spherical filler made of polycarbonate. Subsequently, the antibacterial protective layer is irradiated with ionizing radiation to perfectly cure the ionizing radiation curable resin to produce an antibacterial decorative sheet.

<CIT> describes a decorative plate which has a constitution wherein a decorating treatment layer constituted of a solid ink layer and a pattern ink layer is formed on the surface of a base sheet provided on the surface of a base with an adhesive layer interlaid and wherein a surface protection layer formed of hardening resin coating to which an inorganic antibacterial agent is added is laminated on the decorating treatment layer and a decorative sheet having a formaldehyde trapping layer laminated is stuck on the lower side.

<CIT> describes a substrate having one or more antimicrobial or antistatic properties imparted by applying a coating or film formed from a cationically-charged polymer composition. The polymer composition includes a noncationic ethylenically unsaturated monomer and an ethylenically unsaturated monomer capable of providing a cationic charge to the polymer composition.

The conventional "interior finishing decorative sheets" have the problem of poor antiviral properties because their antiviral properties are imparted only by a silver-based inorganic additive or a zinc-based inorganic additive contained therein.

The present invention has been made focusing on the above point, to improve antiviral properties by using finely divided silver for an antiviral additive.

A decorative sheet according to an aspect of the present invention is defined in claim <NUM>.

Further, the decorative sheet according to an aspect of the present invention is characterized in that:.

The decorative sheet according to an aspect of the present invention is characterized in that:
the coating amount of the surface protective layer is <NUM> or more.

The decorative sheet according to an aspect of the present invention is characterized in that:
the predetermined average particle diameter of the antiviral additive particles is within a range of <NUM> to <NUM>.

The decorative sheet according to an aspect of the present invention is characterized in that:.

The decorative sheet according to an aspect of the present invention is characterized in that:
the surface protective layer further contains a surfactant.

The decorative sheet according to an aspect of the present invention is characterized in that:
the surfactant is composed of one or more types of surfactants, the one or more types of surfactants being selected from cationic, amphoteric, and nonionic surfactants.

A decorative material according to an aspect of the present invention includes:.

A method is provided according to an aspect of the present invention for producing a decorative sheet that includes a paper substrate, a printed pattern layer arranged to face a major surface of the paper substrate, and a surface protective layer arranged to face the pattern layer, the surface protective layer comprising a coating layer as an outermost layer of the decorative sheet, the method comprising:.

According to the aspects of the present invention, using finely divided silver for an antiviral additive improves antiviral properties.

In <FIG>, the reference number <NUM> represents a decorative sheet according to a first embodiment. The decorative sheet <NUM> may be used, for example, for general fittings.

The decorative sheet <NUM> is composed of the following layers laminated in sequence.

Each of these layers will be described later.

The decorative sheet <NUM> is not limited to the above layers (<NUM>) to (<NUM>). Although not illustrated, the surface of the surface protective layer <NUM>, for example, may have an uneven shape formed such as by embossing so as to match the pattern layer <NUM>, or a transparent thermoplastic resin layer may be provided between the pattern layer <NUM> and the surface protective layer <NUM>.

The paper substrate <NUM> serves as the base of the decorative sheet <NUM> of the present invention, and examples thereof include various types of paper, such as thin paper, titanium paper, resin-impregnated paper, resin-mixed paper, reinforced paper, bleached or unbleached kraft paper, linter paper, high-quality paper, coated paper, inorganic paper, flame-resistant paper, paperboard, and traditional Japanese paper.

Further, the paper substrate <NUM> may be composed of a material other than the above types of paper, as long as it has properties similar to paper. Examples of such a material include woven or nonwoven fabrics and the like. The thickness of the paper substrate <NUM> is desirably selected from a range where the paper substrate <NUM> has proper strength and flexibility, from the viewpoint of suitability for attachment to a substrate for a decorative material; normally, a basis weight of <NUM> to <NUM>/m<NUM> is preferable.

The pattern layer <NUM> is formed on the surface of the paper substrate <NUM> using a printing method. The pattern layer <NUM> is provided to impart designability to a target decorative sheet <NUM>.

Examples of the printing method include gravure printing, offset printing, relief printing, flexographic printing, screen printing, inkjet printing, electrostatic printing, and the like. The printing method is not limited to the above example methods, and may be any conventionally known image forming means, such as a hand drawing method, a marbling method, a transfer method, a photographic method, an electrophotographic method, a photosensitive resin method, a vacuum deposition method, a chemical corrosion method, a thermosensitive coloring method, or a discharge breakdown method.

The pattern layer <NUM> has any type of pattern according to the intended use, user's taste, or the like; a wood grain pattern, a stone pattern, an abstract pattern, and the like, for example, are typical. The type of pattern is not limited to the above examples, and may be, for example, solid printing on the entire surface.

Typical printing ink used for printing methods is made by dispersing, in a binder composed of synthetic resin or the like, a colorant, such as an organic or inorganic dye or pigment, together with a solvent or a diluent, and an appropriate additive, such as an extender pigment, a filler, a tackifier, a plasticizer, a stabilizer, a dispersant, an antifoaming agent, a leveling agent, a surfactant, or a drying agent.

While the colorant may be an inorganic pigment, such as titanium dioxide or chrome yellow, for uses that require high concealing performance, typical examples of the colorant include organic pigments that are highly transparent and produce an excellent color effect, such as disazo yellow, hansa yellow, isoindolinone, threne, lake red, brilliant carmine, quinacridone, perylene, anthraquinone, and phthalocyanine, carbon black, and the like.

Examples of the binder include acrylic resins, polyester-based resins, polyamide-based resins, styrene-based resins, vinyl-based resins, urethane-based resins, melamine-based resins, epoxy-based resins, alkyd-based resins, cellulose derivatives, shellac, rosin, modified rosin, phenolic resins, coumarone resins, ketone resins, petroleum resins, and mixtures, copolymers, or the like of two or more thereof.

The surface protective layer <NUM> is provided to impart surface physical properties, such as abrasion resistance and water resistance, to the surface of the decorative sheet <NUM>; further, in the present invention, the surface protective layer <NUM> imparts antiviral properties thereto as a result of having an outermost layer of the decorative sheet <NUM> formed of a coating containing antiviral additive particles comprising at least finely divided silver.

Further, the surface protective layer <NUM> is light transmissive so as to allow a pattern of the pattern layer <NUM> to be viewed from its surface.

The surface protective layer <NUM> is comprised of a single layer or a plurality of layers.

Examples of resins used for the surface protective layer <NUM> include urethane-based resins, acrylic resins, amino-alkyd resins, polyester-based resins, epoxy-based resins, melamine-based resins, fluorine-based resins, cellulose derivatives, ionizing radiation-curable resins, and the like; each of these resins can be used in the present embodiment.

Specifically, the surface protective layer <NUM> is formed by applying, with a gravure coater, a coating liquid obtained by adding an antiviral agent <NUM> to isocyanate-curable "UC Clear" (available from DIC Graphics Corporation). Note that the use of a gravure coater for this application is not meant to be limiting.

The surface protective layer <NUM> has the following characteristics.

Examples of the fluorine-based resin include polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, tetrafluoroethylene-ethylene copolymer, chlorotrifluoroethylene-ethylene copolymer, polyvinyl fluoride (PVF), and the like.

(<NUM>) The coating amount of the surface protective layer <NUM> is <NUM> or more.

Here, the term "coating amount" is related to "application thickness" in the Examples. That is, "coating amount" is related to the surface area of the outermost layer of the surface protective layer <NUM>, corresponds to "application thickness", and is hereinafter also referred to as "application thickness".

(<NUM>) A system obtained by adding an antiviral agent <NUM> (antiviral additive particles) to the surface protective layer <NUM>, for example an "inorganic silver system", also contains a surfactant.

(<NUM>) The surfactant is composed of one or more types of surfactants, the one or more types of surfactants being selected from cationic, amphoteric, and nonionic surfactants.

The antiviral agent <NUM> is an antimicrobial substance made of an inorganic silver-based compound, for example "BIOSAIDO TB-B100" (available from Taisho Technos Co. ), and is also referred to as "antiviral additive particles". Note that the antiviral agent <NUM> is not limited to the example antimicrobial agent and only needs to be a silver-based antiviral agent.

The antiviral agent <NUM> (antiviral additive particles) contains at least finely divided silver.

The antiviral agent <NUM> (antiviral additive particles) has the following characteristics.

For example, the above-mentioned BIOSAIDO TB-B100 was added, as the antiviral agent <NUM>, to above-mentioned isocyanate-curable UC Clear products such that the solid content ratio of the BIOSAIDO TB-B100 was <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> wt% in the respective UC Clear products.

(<NUM>) The average particle diameter of the antiviral additive particles (antiviral agent <NUM>) and the coating amount of the surface protective layer <NUM> are set so as to satisfy the following expression: <MAT> where ϕ is the average particle diameter of the antiviral additive particles, and D is the coating amount of the surface protective layer <NUM>.

(<NUM>) The antiviral additive particles (antiviral agent <NUM>) have an average particle diameter in the range of <NUM> to <NUM>.

(<NUM>) As shown in <FIG>, the antiviral additive particles (antiviral agent <NUM>) used have a particle size distribution with two peaks, one peak at a particle diameter of less than <NUM>, the other peak at a particle diameter of <NUM> or more.

(<NUM>) An active ingredient of the antiviral additive particles (antiviral agent <NUM>) are supported on an inorganic material.

A method for producing the decorative sheet <NUM> is as follows:.

As the pattern layer <NUM>, a wood grain pattern layer is formed by gravure printing.

Although gravure printing is exemplified, this is not meant to be limiting, and inkjet printing may be used instead. Further, although a wood grain pattern is exemplified as a design, this is not meant to be limiting, and other patterns are possible.

(<NUM>) The surface protective layer <NUM> is formed on the surface of the pattern layer <NUM>.

(<NUM>) In this step, first, different coating liquids are prepared by adding the above-mentioned BIOSAIDO TB-B100 to above-mentioned isocyanate-curable UC Clear products such that the solid content ratio of the BIOSAIDO TB-B100 was <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> wt% in the respective UC Clear products.

The antiviral additive particles (antiviral agent <NUM>) contain at least finely divided silver.

(<NUM>) The coating liquid is applied with a gravure coater.

The coating liquid is applied at an application thickness of <NUM>. Note that the use of a gravure coater for this application is not meant to be limiting.

(<NUM>) Subsequently, aging is performed at <NUM> for <NUM> hours to thereby obtain a decorative sheet <NUM>.

Alternatively, the antiviral additive particles (antiviral agent <NUM>) may be a mixture of first antiviral additive particles and second antiviral additive particles, where the first antiviral additive particles have a first predetermined average particle diameter, and the second antiviral additive particles have a second predetermined average particle diameter different from the first predetermined average particle diameter; the second antiviral additive particles are prepared by (<NUM>) finely dividing antiviral additive particles prepared as the first antiviral additive particles, and extracting the second antiviral additive particles from the finely divided antiviral additive particles, or (<NUM>) passing antiviral additive particles prepared as the first antiviral additive particles through a mesh sieve having an opening size different from the first predetermined average particle diameter to thereby extract the second antiviral additive particles therefrom.

With this configuration, as shown in <FIG>, the antiviral additive particles (antiviral agent <NUM>) have a particle size distribution with at least two peaks, one peak at a particle diameter of less than <NUM>, and at least one other peak at a particle diameter of <NUM> or more.

The average particle diameter of the BIOSAIDO TB-B100 as measured with a particle size analyzer was <NUM>. This is the first peak of the particle size distribution.

The second peak of the particle size distribution may be the one inherent in the antiviral agent <NUM>, or may be the artificial one.

For example, the BIOSAIDO TB-B100 was finely divided to have an average particle diameter of <NUM>.

Mixing the BIOSAIDO TB-B100 having an average particle diameter of <NUM> and the finely divided BIOSAIDO TB-B100 having an average particle diameter of <NUM> in a ratio of, for example, <NUM>:<NUM> can artificially create the first peak due to the average particle diameter of <NUM> and the second peak due to the average particle diameter of <NUM> of the finely divided BIOSAIDO TB-B100.

Further, other than pulverization, the BIOSAIDO TB-B100 may be passed through a mesh sieve with an opening size of <NUM>, which is greater than the average particle diameter of <NUM>. Conversely, the BIOSAIDO TB-B100 may be passed through a mesh sieve which has an opening size less than the average particle diameter of <NUM>, for example an opening size of less than <NUM>.

A decorative material can be obtained by attaching the decorative sheet <NUM> obtained using the above-described production method to a surface layer of a building material (not shown).

Advantageous effects of the present embodiment are as follows:.

The content of the antiviral additive particles (antiviral agent <NUM>) is preferably <NUM> wt% to <NUM> wt%, and more preferably <NUM> wt% to <NUM> wt%.

If the content of the antiviral additive particles is below <NUM> wt%, the antiviral activity value tends to be low.

If the content of the antiviral additive particles is more than <NUM> wt%, the resin content is low, and thus the coating layer tends to be brittle.

Specifically, in this case, the coating layer tends to be damaged or peel off, and this damage in particular has a large influence.

(<NUM>) According to the present embodiment, the coating amount of the surface protective layer <NUM> is <NUM> or more, resulting in an increase in the absolute amount of antiviral agent, thus allowing an antiviral effect to be exhibited.

Further, according to the present embodiment, silver ions migrate through the coating film and act on viruses; thus, silver not present in the outermost layer also contributes to antiviral properties.

(<NUM>) According to the present embodiment, the expression <NUM>. 5D ≤ ϕ ≤ 2D is satisfied, where ϕ is the average particle diameter of the antiviral additive particles (antiviral agent <NUM>), and D is the coating amount of the surface protective layer <NUM>; exposing a certain amount of the antiviral agent at the surface of the surface protective layer <NUM> based on the relationship between the coating amount and the average particle diameter is more likely to allow an antiviral effect to be exhibited.

(<NUM>) According to the present embodiment, the antiviral additive particles (antiviral agent <NUM>) has an average particle diameter in the range of <NUM> to <NUM>, and has a particle size distribution with one peak at less than <NUM> and at least one other peak at <NUM> or more; a large average particle diameter of the antiviral additive particles is desired in order for the antiviral agent to be exposed at the surface of the surface protective layer <NUM>, and a small average particle diameter of the antiviral additive particles and thus a large surface area thereof are desired in order for silver ions to be easily generated; the above configuration can achieve both of these effects.

(<NUM>) According to the present embodiment, the active ingredient of the antiviral additive particles (antiviral agent <NUM>), that is, finely divided silver, is supported on, for example, an inorganic material. This configuration improves the dispersibility of the active ingredient, thus suppressing blooming over time.

That is, if finely divided silver is added alone to the "coating liquid" described later in Example <NUM>, the finely divided silver may aggregate, and may cause blooming because of low affinity for the "coating resin" described later in Example <NUM>. Such problems can be avoided by allowing the finely divided silver to be supported on an inorganic material.

(<NUM>) According to the present embodiment, a system obtained by adding antiviral additive particles (antiviral agent <NUM>) to the surface protective layer <NUM> also contains a surfactant. The surfactant increases the dispersibility of the antiviral additive particles and thus the transparency of the surface protective layer, thereby improving the designability.

Note that, because antagonism occurs between an anionic surfactant and silver ions, other surfactant systems are desirably used.

(<NUM>) According to the present embodiment, a decorative material is obtained by attaching the decorative sheet <NUM> to a surface layer of a building material. This minimizes the risk of viral infections via the decorative material because viruses adhered to the outermost surface of the decorative sheet <NUM> are reduced by <NUM>% or more within <NUM> hours.

Examples <NUM> to <NUM> of decorative sheets according to the present invention, Comparative Examples <NUM> to <NUM>, and a comparative blank will be described. The present invention is limited to the following Examples <NUM> to <NUM>.

A decorative sheet of Examples <NUM> to <NUM> was produced in the following manner.

A wood grain pattern layer was formed on a surface of each prepared paper substrate by gravure printing. Subsequently, different coating liquids were each prepared by adding "BIOSAIDO TB-B100" (available from Taisho Technos Co. ) to isocyanate-curable "UC Clear" (available from DIC Graphics Corporation) such that the solid content ratio of the BIOSAIDO TB-B100 was <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> wt% in the respective coating liquids. These coating liquids were then applied with a gravure coater to the respective pattern layers at an application thickness of <NUM>.

Here, although an acrylic coating material was used as the coating liquid, this is not meant to be limiting.

Subsequently, aging was performed at <NUM> for <NUM> hours to thereby obtain decorative sheets of Examples <NUM> to <NUM>.

The solid content ratio of the BIOSAIDO TB-B100 was <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; and <NUM> wt% for Example <NUM>.

Further, an active ingredient of the antiviral additive particles, that is, an inorganic silver-based compound in the case of BIOSAIDO TB-B100, was supported on an inorganic material.

That is, finely divided silver was used for the BIOSAIDO TB-B100, and the finely divided silver was supported on an inorganic substance.

The decorative sheets of Examples <NUM> to <NUM> were obtained under the same conditions as for Examples <NUM> to <NUM>, respectively, except that the prepared coating liquids were applied to the respective pattern layers at an application thickness of <NUM>.

The solid content ratio of the BIOSAIDO TB-B100 was <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; <NUM> wt% for Example <NUM>; and <NUM> wt% for Example <NUM>.

The decorative sheet of Reference Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100), except that BIOSAIDO TB-B100 was finely divided to have an average particle diameter of <NUM>. <NUM> for use in the coating liquid.

The decorative sheet of Reference Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100), except that BIOSAIDO TB-B100 was passed through a mesh sieve with an opening size of <NUM> to have an average particle diameter of <NUM> or more.

The decorative sheet of Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100), except that finely divided silver (not supported on an inorganic substance) was used for BIOSAIDO TB-B100.

The decorative sheet of Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100) using the same method as for Example <NUM>, except that <NUM> part by mass of an alkyl trimethyl ammonium salt as a cationic surfactant was added as a surfactant component to <NUM> parts by mass of the antiviral agent.

The decorative sheet according to Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100) using the same method as for Example <NUM>, except that an alkyl dimethyl amine oxide as an amphoteric surfactant was used instead of the cationic surfactant in Example <NUM>.

The decorative sheet of Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100) using the same method as for Example <NUM>, except that polyethylene glycol as a nonionic surfactant was used instead of the cationic surfactant in Example <NUM>.

The decorative sheet of Comparative Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100), except that the corresponding prepared coating liquid was applied to the pattern layer at an application thickness of <NUM> as in Example <NUM>.

The decorative sheet of Comparative Example <NUM> was obtained under the same conditions as for Example <NUM> (including the solid content ratio of <NUM> wt% for BIOSAIDO TB-B100) using the same method as for Example <NUM>, except that a fatty acid salt as an anionic surfactant was used instead of the cationic surfactant in Example <NUM>.

As a comparative blank, a decorative sheet was produced using the same method as for Example <NUM>, except that BIOSAIDO TB-B100 was not contained therein.

The evaluation method and evaluation criteria are as follows.

The decorative sheets of Examples <NUM> to <NUM> and Comparative Examples <NUM> to <NUM> were subjected to antiviral testing, and visual evaluation of surface transparency.

The antiviral testing method was as follows:.

The method of calculating virus infectivity titer is represented by the following Equation <NUM>: <MAT>.

The method of calculating an antiviral activity value is represented by the following Equation <NUM>: <MAT>.

An antiviral activity value of <NUM> or more is considered as "having an antiviral effect".

Evaluation criteria are broadly divided into the following two types, namely "Evaluation <NUM>" and "Evaluation <NUM>".

Evaluation <NUM> refers to a criterion for evaluating "activity value" such that an activity value of <NUM> or more is evaluated as "Good", whereas an activity value of less than <NUM> is evaluated as "Poor".

Evaluation <NUM> refers to criteria for evaluating "surface clarity" such that "transparent" is evaluated as "Excellent"; "slightly cloudy" (in the case of cloudiness only being observed directly under a fluorescent light) is evaluated as "Fair"; and "cloudy" (in the case of cloudiness being observed even without a fluorescent light directly above) is evaluated as "Poor".

Table <NUM> below shows the evaluation results for the respective decorative sheets.

Comparing Example <NUM>, Reference Example <NUM>, and Reference Example <NUM>, Example <NUM>, which contained the original TB-B100 having two peaks in the particle size distribution, showed an activity value of <NUM>.

In contrast, Reference Examples <NUM> and <NUM>, designed to have one peak in the particle size distribution, showed an activity value of <NUM> and an activity value of <NUM>, respectively.

These results indicate that Example <NUM>, which was designed to have two peaks in the particle size distribution, tended to have a higher activity value than Reference Examples <NUM> and <NUM>, which were designed to have one peak in the particle size distribution, and thus was presumed to have a stronger antiviral effect.

Comparing Examples <NUM> to <NUM> and Comparative Example <NUM>, although the added surfactant in Examples <NUM> to <NUM> and Comparative Example <NUM> improved the dispersibility of the antiviral agent and thus increased the transparency, they tended to show a slightly lower activity value because the antiviral agent was coated with the surfactant.

Note that the Comparative Example <NUM>, which contained the anionic surfactant, tended to show a significantly lower activity value.

As a result of evaluating Examples <NUM> to <NUM> and Comparative Examples <NUM> and <NUM> in terms of "activity value" by comparing these examples, Examples <NUM> to <NUM>, where the application thickness was <NUM> or more, were found to tend to have a higher activity value than Examples <NUM> to <NUM> and Comparative Examples <NUM> and <NUM>, where the application thickness was <NUM>, and thus were presumed to have a stronger antiviral effect.

As a result of evaluating Examples and Comparative Examples in terms of "activity value", it was revealed that a higher solid content ratio tended to provide a higher activity value and thus was presumed to achieve a stronger antiviral effect.

As a result of evaluating Examples and Comparative Examples in terms of "surface clarity", the application thickness is presumed to have only a small effect on the surface clarity.

Further, as a result of evaluating Examples and Comparative Examples in terms of "surface clarity", a higher solid content ratio was presumed to tend to cause cloudiness.

As an evaluation in terms of "surface clarity", the more transparent the surface protective layer <NUM> is, the easier it is to see the pattern of the pattern layer <NUM> from the outermost side of the surface protective layer <NUM>. However, "transparent" is not necessarily good, and "slightly cloudy" or "cloudy" may be sufficient for practical use, depending on the intended use or purpose of the decorative sheet <NUM>.

If transparency is required for the surface protective layer <NUM> depending on the intended use or purpose of the decorative sheet <NUM>, adding a surfactant as in Examples <NUM> to <NUM> improves the transparency thereof, although the activity value tends to be slightly reduced in this case.

Claim 1:
A decorative sheet comprising:
a paper substrate;
a printed pattern layer arranged to face a major surface of the paper substrate; and
a single-layer or multilayered surface protective layer arranged to face the pattern layer, the surface protective layer comprising a coating layer as an outermost layer of the decorative sheet, the coating layer having a predetermined thickness,
the coating layer being comprised of a coating containing antiviral additive particles having a predetermined average particle diameter with one peak at a particle diameter of less than <NUM> and at least one other peak at a particle diameter of <NUM> or more, the antiviral additive particles comprising finely divided silver,
characterized in that
an amount of the antiviral additive particles in the coating layer is <NUM> mass% or more and <NUM> mass% or less relative to a total solid content of the coating layer, and the predetermined average particle diameter of the antiviral additive particles and the coating amount of the surface protective layer satisfy the following expression: <MAT>
where ϕ is the predetermined average particle diameter of the antiviral additive particles, and D is the coating amount of the surface protective layer.