JP2003011145A - Decorative panel manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative panel manufacturing method capable of manufacturing a decorative panel without deforming a printing pattern and capable of corresponding even to the small-quantity production of a product. SOLUTION: A substrate 5 impregnated with a melamine resin 50, a resin unimpregnated decorative sheet 30 having a printing layer 2 formed thereto by ink jet printing and not impregnated with a resin and an overlay 1 impregnated with a melamine resin 10 are prepared to be laminated and the formed laminate is pressed under heating to manufacture the decorative panel.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a decorative sheet having a printed pattern.

[0002]

2. Description of the Related Art Decorative boards made of resin-impregnated paper with a pattern such as a wood grain pattern are used as surface materials for furniture and building materials. As a specific example of such a decorative plate, there is a conventional one shown in FIG. 5 as described later. That is, the conventional decorative board 9
6 is a printed layer 92 having a desired pattern on a base material 95.
There is a case where a decorative sheet 93 is formed and the surface is covered with a transparent overlay 91. Since the decorative sheet 93 has a concealing property, the base material 95 is hidden so that the color of the printed layer 92 can be seen.

A method of manufacturing the decorative board will be described. Kraft paper is impregnated with phenolic resin, and this is used as the base material 95. The melamine resin is exposed and impregnated into the kraft paper to form an overlay 91. As shown in FIG. 6, in the printing step, the printing layer 92 is formed on the titanium paper 931 having a concealing property and containing titanium oxide. Subsequently, in the impregnation step, the titanium paper 931 is passed through the resin bath 935 by the feed roller 934 to impregnate the resin 932. Next, in a drying step, the resin 932 is dried by passing through the dryer 937. As a result, the print layer 92
A decorative sheet 93 having is obtained.

Then, as shown in FIG.
5. The decorative sheet 93 and the overlay 91 are sequentially laminated and heated and pressed. As a result, the resin impregnated therein is thermoset, and an integrated decorative plate 96 is obtained.

[0005]

However, in the above-described conventional method for manufacturing a decorative plate, the decorative sheet 93 is made of resin 93.
Since 2 was impregnated, there were the following problems. First,
During the impregnation step, the ink of the printing layer 92 melts in the resin bath 935. Therefore, the sharpness of the pattern of the printed layer 92 may be reduced.

Secondly, when the decorative sheet 93 is inserted between the feed rollers 934 in the impregnation step, as shown in FIG. 7, the resin-impregnated decorative sheet 93 is moved in the direction orthogonal to the roller feeding direction X, that is, in the width direction Y. It will grow. Therefore, the pattern 921 formed of the print layer printed on the decorative sheet 93 is also deformed. The deformation state at this time is the decorative sheet 93.
The length of the pattern 921 in the roller feed direction X is 900 mm before and after the resin impregnation, which is almost unchanged, but the length in the width direction Y is 900 mm when the resin is not impregnated, but becomes 910 mm after the resin impregnation.

Third, a dryer 937 used in the drying process
Requires a certain length to dry the resin of the decorative sheet 93. Its length is several tens of meters. Therefore, even when making a product with a short length, the same length as the length of the dryer 937 is the minimum required,
Excessive parts other than those necessary for the product will occur. Therefore, it is not suitable for small-scale production of products.

In view of the above-mentioned conventional problems, the present invention is to provide a method for manufacturing a decorative board that can be manufactured without deforming a printed pattern and can be applied to small-scale production of products. .

[0009]

A first invention is to provide a base material impregnated with a resin, a resin-unimpregnated decorative sheet having a printing layer formed by inkjet printing and not impregnated with the resin, and a resin impregnated sheet. An overlay is prepared, and the base material, the resin-unimpregnated decorative sheet and the overlay are laminated and heated and pressed, which is a method for producing a decorative plate (claim 1).

In the first invention, a base material impregnated with a resin, a resin-unimpregnated decorative sheet having a printed layer and not impregnated with the resin, and an overlay impregnated with the resin are laminated, and these are heated. Pressurized. At this time, the resin in the overlay and the resin in the base material penetrate into the resin-unimpregnated decorative sheet, and this serves as an adhesive. Also, according to inkjet printing, a print layer is formed from a group of dots. From the gaps between the dots, the resin in the overlay and the base material easily penetrates into the decorative sheet during heating and pressing. Therefore, the resin is sufficiently impregnated into the resin-unimpregnated decorative sheet by heating and pressing. Therefore, according to the first invention, an integrated decorative board can be manufactured.

According to the first aspect of the invention, after the printing layer is formed on the decorative sheet, the laminating step is carried out without impregnating the resin, so that the following effects are obtained. First, since the decorative sheet is not impregnated with resin, there is no risk that the ink in the printing layer will dissolve into the resin bath. Therefore, the pattern of the printed layer can be seen clearly. Secondly, since there is no resin impregnation step for impregnating the decorative sheet with resin, there is no deformation of the decorative sheet that occurs during the impregnation step and no deformation of the printing layer. Thirdly, since there is no impregnation process for impregnating the decorative sheet with resin, no drying process is required. Therefore, it is not necessary to consider the length for inserting the dryer, and a short product can be manufactured without waste.

Fourth, since it is not necessary to impregnate the decorative sheet with resin in advance, the amount of resin used can be reduced accordingly. Fifth, the resin impregnation step for impregnating the decorative sheet with the resin and the resin drying step are not required, and the manufacturing process is simplified.

Next, in ink jet printing, ink ejection is controlled to form a pattern composed of a group of ink dots. Therefore, the pattern can be arbitrarily changed by controlling the ejection of ink. Therefore, different patterns can be easily formed at low cost for each product. Also, full-color printing can be performed by ejecting inks of a plurality of colors and mixing them at an appropriate ratio. Therefore, multicolor printing can be easily performed.

Further, by ink jet printing, it is possible to form a printing layer composed of dots of ink having substantially the same size. Therefore, the resin uniformly penetrates into the decorative sheet from between the dots during heating and pressurization, and uneven resin impregnation can be prevented.

As described above, according to the first aspect of the present invention, it is possible to provide a method of manufacturing a decorative board that can be manufactured without deforming a printed pattern and can be used for small-scale production of products.

The second invention is a substrate impregnated with a resin,
A resin-unimpregnated decorative sheet on which a printed layer consisting of a group of dots is formed and not impregnated with resin, and an overlay impregnated with resin are prepared, and the base material, the resin-unimpregnated decorative sheet and the overlay are prepared. A method for manufacturing a decorative board is characterized in that the decorative boards are laminated and heated and pressed (claim 2).

In the second invention, as in the first invention,
The decorative sheet with the printed layer is not impregnated with resin, and the base material already impregnated with resin and the overlay are laminated and heated and pressed. For this reason, the resin in the base material and the overlay is impregnated into the resin-unimpregnated decorative sheet, and these are integrated to manufacture a decorative board. Also,
Since the decorative sheet is not impregnated with resin before lamination, the same effect as the first invention can be obtained. Further, in the second invention, since the printed layer is composed of a group of ink dots, when the transparent paper is resin-impregnated paper, the resin is uniformly impregnated between the dots and the resin is impregnated between the dots. Impregnation unevenness can be prevented.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the first invention, the resolution of dots formed by inkjet printing is 1500 dp.
It is preferably i or less. If it exceeds 1500 dpi, the ink dots serve as a barrier to impair resin impregnation into the printed paper, and the printed layer may peel off.

In ink jet printing, the ejection amount of ink can be controlled freely. Therefore, dots of almost the same size can be printed, and the dot size can be positively changed. In the latter case, a smooth gradation pattern can be created. The print layer has a light pattern when the dot density is low, and a dark pattern when the dot density is high. The print layer may be composed of a set of dots of only one color, or may be composed of a combination of a plurality of colors.

The ink used for ink jet printing is preferably a water-based pigment ink. The light resistance and heat resistance of the printed pattern are improved. Further, the ink may be a solvent-based pigment ink. In this case, heat resistance, boiling resistance, cigarette resistance, etc. are also sufficiently satisfied. Furthermore, since it dries quickly, it is possible to suppress wrinkling of paper due to wetting.

As the base material used for the decorative board, one or a plurality of papers impregnated with a resin can be used. The paper used as the base material here is kraft paper, linter paper, or the like, and the resin is a thermosetting resin such as phenol resin, diallyl phthalate resin, melamine resin, or epoxy resin. Also, plywood or wood board can be used as the base material.

The overlay comprises, for example, resin impregnated paper. As this resin, the same resin as that used to impregnate the transparent paper can be used. Among them, melamine resin is preferable from the viewpoint of designability and surface performance (hardness, water resistance, etc.). As the paper used for overlay,
Transparent paper with little or no ash content is used, such as wood pulp fiber paper, linter cotton fiber paper, polyester film and the like, which contains a large amount of α-cellulose component.

The base material, the resin-unimpregnated decorative sheet having the printed layer, and the overlay are laminated and then integrated by heating and pressing. The heating and pressing conditions are 80 to 20.
At 0 ° C., it is preferably ²⁰ to 150 kg / cm ² and 5 to 60 minutes.

It is preferable that the resin-unimpregnated decorative sheet has a property of becoming transparent by impregnating the resin that permeates from the overlay and the base material by the heating and pressing (claim 3). Since the decorative sheet becomes transparent due to the resin impregnation, not only the surface portion of the printed layer remaining on the surface of the decorative sheet, but also the permeated portion of the printed layer that has penetrated into the decorative sheet can be visually recognized. Therefore, the entire printed layer can be seen from the outside and the color tone reproducibility is good.

The above-mentioned resin-impregnated transparent decorative sheet has such a transparency that the background from the front side to the back side is transparent, and it has a clear or clear appearance, and includes completely transparent and semi-transparent. Examples of the paper used for the decorative sheet include wood pulp fiber paper with a large amount of α-cellulose component, manila hemp pulp fiber paper, linter cotton fiber paper, wood-based natural pulp non-woven fabric, polyester non-woven fabric and the like.

The content of ash in the resin-unimpregnated decorative sheet is preferably 0 to 1.5% by weight (claim 4). Here, the ash content in the decorative sheet means the amount including the ash originally included in the decorative sheet. If the ash content exceeds 1.5% by weight, the transparency of the decorative sheet may be reduced. The ash means an inorganic compound such as an inorganic oxide. Titanium oxide is also included in this, for example.

It is preferable to dispose a hiding material between the base material and the resin-unimpregnated decorative sheet (claim 5). For this reason, the hiding material makes the base material invisible,
The print layer looks good. The hiding material may be any material that is opaque and obscures the substrate. The hiding material may be plain or colored. Further, a pattern such as a ground pattern may be added. When a pattern is attached, it can be viewed as a three-dimensional pattern in combination with the pattern of the print layer above it.

The hiding material is preferably resin-impregnated paper obtained by impregnating paper with resin. This is because not only can the decorative sheet and the base material be integrally bonded, but coloring and patterns can be easily formed on the paper. In this case, the ash content of the paper used as the hiding material is preferably 8 to 30% by weight based on the weight of the paper. As such paper, for example,
Examples include titanium paper (made by Kojin Co., Ltd.). If it is less than 8% by weight, the base material may be visible through the concealing material, and if it exceeds 30% by weight, the resistance of the paper may decrease and the paper may break during impregnation. It may be up. Examples of the resin used for the hiding material include thermosetting resins such as melamine resin, unsaturated polyester resin and diallyl phthalate resin.

Next, in the second invention, the diameter of each dot is preferably within ± 50% of the average diameter. Uniform gaps are formed between dots,
Since the resin is impregnated into the paper through this gap, it is unlikely that a non-impregnated resin portion is locally formed on the decorative sheet. Therefore, the printed layer firmly adheres to the decorative sheet and is difficult to peel off. On the other hand, when there are dots having a diameter that deviates from the average dot diameter by ± 50%, the gaps between the dots are unevenly distributed, and the adhesion of the print layer to the decorative sheet may be reduced. is there.

As for the average diameter, the average value of the diameter of one dot is measured with a KEYFME type microscope VH-7 or the like, and this is performed for all the dots on the screen to calculate the average diameter of all the dots. A screen with a magnification of about 50 is desirable.

In the second invention, when the dot is a circle, the diameter of the dot means the diameter of the dot, and when it is not a circle, the diameter of the dot means the maximum diameter and the maximum diameter of one dot. The average with the small diameter. The average diameter of dots means a value obtained by adding the diameters of all the dots in the dot group constituting the print layer and dividing by the number of dots. The print layer including the set of dots can be formed by, for example, inkjet printing.

In addition, the second invention is also the same as the first invention (claims 3 to 5).

[0033]

EXAMPLES Example 1 A decorative board according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the decorative plate 6 of this example includes a base material 5, a decorative sheet 3 adhered to the base material 5, and an overlay 1 covering the surface thereof.
Consists of. The decorative sheet 3 has an ink-jet printed printing layer 2 on the side opposite to the side to which the substrate 5 is adhered. The decorative sheet 3 is impregnated with resin at the time of stacking and heating. The ash content in the decorative sheet 3 is 0.1% by weight.

The print layer 2 formed by ink jet printing forms a pattern 21 composed of a group of dots 20, as shown in FIG. This pattern 21 is shown in FIG.
As shown in (b), the dots 20 have almost the same size. The average diameter of the dots 20 is 200 μm, and the variation in the diameter of the dots is −50 to + 50% of the average diameter.
Is. As shown in FIG. 2C, the pattern 21 changes the arrangement and density of the ink dots 20 to generate light and shade. The light-colored portion 21a of the pattern 21 is
The density of the dots 20 of the ink is reduced, and the dark color portions 21b increase the density of the dots 20. As shown in FIG. 2C, the pattern 21 has dots 20a and 20b of plural kinds of colors.
It consists of a set of.

In the production of the decorative board of this example, the paper used for the decorative sheet 3 has an ash content of 0.1% and a basis weight of 45.
A wood pulp fiber paper having a large amount of g / m ² of α-cellulose component was prepared. A print layer 2 composed of a set of dots 20 was formed on this paper by inkjet printing. In inkjet printing, a scanner that captures an image, a computer that processes the image, an inkjet printer that outputs the processed image (trade name DesignJet 5
000PS; manufactured by Hewlett-Packard). The output image resolution is 600 dpi. The ink used for inkjet printing is a water-based pigment ink. Take in the desired image from the scanner, process the image with the computer, output the processed image from the printer,
A desired pattern was formed by a printing layer composed of a group of dots. At this stage, the decorative sheet is not impregnated with resin. As described above, the resin-unimpregnated decorative sheet 30 on which the printed layer 2 is formed is obtained.

Next, as the paper used for the overlay 1,
A wood pulp fiber papermaking paper having a basis weight of 18 g / m ² and an ash content of 0.1% and a large amount of transparent α-cellulose component was prepared. The paper 11 was impregnated with the melamine resin 10 to obtain an overlay 1.

As the substrate 5, five pieces of bleached kraft paper 51 (basis weight: 180 g / m ² ) impregnated with the melamine resin 50 were prepared.

Next, as shown in FIG. 3, the above five base materials 5, the resin-unimpregnated decorative sheet 30 having the printed layer 2 formed thereon, and the overlay 1 are laminated, and the flat plate 8 is heated from above to apply heat. did. The applied pressure is 785 × 10 ⁴ Pa and the heating temperature is 150 ° C. From the above, the thickness 1.
A 2 mm decorative plate 6 is obtained.

In this example, as shown in FIG. 3, the base material 5 impregnated with the melamine resin 50 and the resin-unimpregnated decorative sheet 30 on which the printed layer 2 is formed and is not impregnated with resin.
And the overlay 1 impregnated with the melamine resin 10 are laminated, and these are heated and pressed. At this time, the melamine resin 10 in the overlay 1 and the melamine resin 50 in the base material 5 penetrate into the resin-unimpregnated decorative sheet 30, and this serves as an adhesive.

Further, according to the ink jet printing, as shown in FIG.
As shown in (a) to (c), the print layer 2 is formed from a group of dots 20. From the gap between the dots 20,
During heating and pressurization, the resin in the overlay 1 and the base material 5 easily penetrates into the resin-unimpregnated decorative sheet 30. Therefore, the resin is sufficiently impregnated into the resin-unimpregnated decorative sheet 30 by heating and pressing. Therefore, according to the first invention, an integrated decorative board can be manufactured.

Further, after the printing layer 2 is formed on the decorative sheet 3, the lamination process is carried out without impregnating the resin, so that the ink in the printing layer does not melt into the resin bath.
There is no deformation of the decorative sheet during the impregnation process and no deformation of the printed layer. No drying step is required. For this reason, it is not necessary to consider the length for inserting the dryer, and it is possible to produce short products without waste and economically support small-volume production. Since it is not necessary to impregnate the decorative sheet with resin in advance, the amount of resin used can be reduced accordingly.

Next, in ink jet printing, the pattern can be arbitrarily changed by controlling the ejection of ink.
Therefore, different patterns can be easily formed at low cost for each product. Also, full-color printing can be performed by ejecting inks of a plurality of colors and mixing them at an appropriate ratio. In addition, it is possible to form a print layer including dots of ink having substantially the same size by inkjet printing. Therefore, the resin uniformly penetrates into the decorative sheet from between the dots, and uneven resin impregnation can be prevented. The decorative sheet becomes transparent when it is impregnated with resin. Therefore, as shown in FIG. 1, the surface portion 2 of the printing layer 2 remaining on the surface of the decorative sheet 3
Not only 10 but also the printed layer 2 that penetrates into the decorative sheet 3
The appearance of the permeation part 220 can also be recognized. Therefore, the entire printed layer 2 can be seen from the outside and the color tone reproducibility is good.

(Comparative Example 1) In this example, FIG.
As shown in, the pattern 21 was formed by performing gravure printing instead of the inkjet printing of Example 1. In gravure printing, light and shade are produced by changing the size of the ink dots 20. In FIG. 2D, reference numeral 20c is a small dot and forms a thin portion in the pattern 21. Reference numeral 20d represents a large dot, which forms a dark portion in the pattern 21. Average dot diameter is 300
μm, and the variation of the dot diameter is −
52% to + 53%. Others are the same as in the first embodiment.

As shown in FIG. 2E, in the gravure printing, there is a large variation in the size of the dots 20, and the overlay 1 immediately above the large dot 20d is easily peeled off, and the transparent paper 3 immediately below the resin 1 is not impregnated with the resin 38. It is easy to

(Embodiment 2) In the decorative board of this embodiment, as shown in FIG. 4, a concealing material 4 is provided between the decorative sheet 3 and the base material 5. The hiding material 4 is opaque white. The paper used for the hiding material 4 has a basis weight of 80 g / m ² and an ash content of 2
0% titanium paper (manufactured by Kojin Co., Ltd.) was prepared. This paper was impregnated with a melamine resin to obtain a hiding material 4. As the substrate 5, five pieces of unbleached kraft paper (basis weight: 180 g / m ² ) impregnated with phenol resin were prepared.

Five sheets of the above-mentioned substrate, a hiding material, a resin-unimpregnated decorative sheet having a printed layer formed thereon, and an overlay were laminated in this order, and these were heated and pressed. As described above, the decorative plate 6 of this example is obtained.

In this example, an overlay is placed on the resin-unimpregnated decorative sheet, and a masking material is placed below the overlay, and these are heated and pressed. Therefore, the concealing material and the melamine resin in the overlay permeate into the decorative sheet and bond together. The base material 5 becomes invisible due to the masking material 4, and the appearance of the printed layer 2 is improved, so that the printed layer 2 can be seen more clearly. In addition, in this example, the same effect as that of the first embodiment can be exhibited.

(Experimental Example 1) The reproducibility of color tone and saturation of a decorative board was measured. The reference color of the color tone is C (cyan) 0% and M (magenta) 10 of DIC Color Chart 1 (Dainippon Ink and Chemicals Co., Ltd., 1st printing issued in July 1997).
0%, Y (yellow) 100%, BL (black) 0%
Was used.

The veneer used for the measurement is the veneer of the present invention and the comparative veneer. The decorative board of the present invention is the same as the decorative board of the second embodiment. As shown in FIG. 5, the comparative decorative board is a decorative sheet 93 having a shielding property and a printing layer 92 formed by inkjet printing. The shielding sheet 93 having a shielding property is titanium paper having an ash content of 15%. The overlay 91 and the base material 95 are the same as the overlay and the base material of the decorative board according to the present invention. 5
Sheet of base material 95, decorative sheet 93, and overlay 91
Were laminated and heated from above with pressing with a flat plate. Applied pressure is 785 × 10 ⁴ Pa, heating temperature is 150 ° C.
Is. As described above, the decorative plate 6 having a thickness of 1.2 mm is obtained.

The printing layers used in the present invention and the comparative decorative board are those in which the color chart of the reference color is read by the scanner and the same image as the color chart read based on the data is output by the printer. The output image resolution is 360 dpi.

Regarding these decorative boards, a color difference meter (trade name: color meter Z, manufactured by Nippon Denshoku Industries Co., Ltd.)
F2000) was used to measure lightness (L), red to green (a), yellow to blue (b), and color difference (ΔE). Note that a is the X axis in the chromaticity diagram measured by the color difference meter, b is the Y axis, and L is the Z axis.
It is an axis. The color difference (ΔE) is calculated by the following formula.

ΔE = (L ² + a ² + b ² ) ^1/2

The saturation of the decorative board is calculated by the following formula.

Saturation = √ (a ² + b ² ).

This saturation is a when the lightness is constant,
It corresponds to the distance from the 0 point of the numerical coordinates of b. The results of these measurements are shown in Table 1.

As is clear from Table 1, the brightness (L), red ~
With respect to green (a), yellow to blue (b), and saturation, the decorative board of the present invention was almost the same as the reference color. On the other hand, the comparative decorative board was thinner than the standard color. From this,
It can be seen that the decorative board of the present invention has good color reproducibility.

[0057]

[Table 1]

(Experimental Example 2) The reproducibility of color tone and saturation of a comparative decorative board using gravure printing was measured. The comparative decorative board was subjected to gravure printing instead of inkjet printing to form a printing layer. Others are the same as the decorative board of Example 1 (FIG. 1). The measuring method is the same as in Experimental Example 1 above. The measurement results are shown in Table 2.

As can be seen from the table, in the comparative decorative plate, since the gravure printing was performed, the ink deposition amount was small and the reproducibility was extremely poor. Compared with the decorative board of the present invention shown in Table 1 of Experimental Example 1, the ink-jet printed decorative board of the present invention can control the ink ejection amount. It was possible to reproduce a color tone close to the color.

[0060]

[Table 2]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a decorative plate of Example 1.

FIG. 2 is a plan view (a) of a decorative plate showing a pattern formed by inkjet printing, an explanatory view of dots formed by inkjet printing (b), and a decorative plate formed by inkjet printing in Example 1. Sectional view (c), and a plan view (d) of a decorative board showing a pattern formed by gravure printing and a sectional explanatory view (e) of a decorative board formed by gravure printing in Comparative Example 1.

FIG. 3 is an explanatory view showing a method for manufacturing a decorative board in Example 1.

FIG. 4 is a cross-sectional view of a decorative plate of Example 2.

FIG. 5 is a cross-sectional view of a comparative decorative plate in Experimental Example 1.

FIG. 6 is an explanatory diagram of a manufacturing process of a decorative sheet in a conventional example.

FIG. 7 is a plan view (a) of a decorative sheet not impregnated with resin and a plan view (b) of a decorative sheet impregnated with resin in a conventional example.

[Explanation of symbols]

1. ． ． overlay, 2. ． ． Print layer, 20. ． ． Dot, 3. ． ． Cosmetic sheet, 30. ． ． Resin unimpregnated decorative sheet, 4. ． ． Concealment material, 5. ． ． Base material, 6. ． ． Veneer,

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 105: 06 B29K 105: 06 B29L 31:10 B29L 31:10 F term (reference) 2E110 AA57 BA03 BA12 BB02 EA09 GA07W 4F204 AA27 AA37 AA38 AA39 AD06 AD35 AG03 AH46 AH51 FA01 FB01 FB11 FB22 FG02 FG09 FN11 FN15

Claims (5)

[Claims] 1. A base material impregnated with a resin, a resin-unimpregnated decorative sheet having a printed layer formed by inkjet printing and not impregnated with the resin, and an overlay impregnated with the resin are prepared. A method for manufacturing a decorative board, comprising laminating a base material, the resin-unimpregnated decorative sheet and an overlay, and heating and pressing. 2. A resin-impregnated decorative sheet having a base material impregnated with a resin, a printed layer composed of a group of dots and not impregnated with the resin, and an overlay impregnated with the resin are prepared. Then, the base material, the resin-unimpregnated decorative sheet, and the overlay are laminated and heated and pressed to produce a decorative plate. 3. The resin-unimpregnated decorative sheet according to claim 1 or 2, wherein the resin-impregnated decorative sheet has a property of becoming transparent when impregnated with a resin that permeates from the overlay and the base material by the heating and pressing. A method for manufacturing a decorative board, comprising: 4. The method for manufacturing a decorative board according to claim 3, wherein the ash content in the resin-unimpregnated decorative sheet is 0 to 1.5% by weight. 5. The method according to any one of claims 1 to 4,
A method for manufacturing a decorative board, comprising disposing a hiding material between the base material and the resin-unimpregnated decorative sheet.