JP2014012393A - Artificial marble plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial marble plate, easy to design a marble pattern, capable of surely expressing a lamination pattern on peripheral surface, having reduced cost and low environmental load.SOLUTION: An artificial marble plate is composed by laminating several bleached kraft paper layer 30 and several decorative paper layer 20 alternately in which front and rear both surfaces of the artificial marble plate become the decorative paper 20. The bleached kraft paper layer 30 has a thickness of 2 mm or less and a total light transmittance of 20 to 90%, and the total light transmittance of each decorative paper 20 is less than 30%. Thermosetting resins are respectively previously impregnated into the bleached kraft paper layer 30 and the decorative paper layer 20, and each bleached kraft paper layer 30 and decorative paper layer 20 are integrated by thermal pressure molding.

Description

  The present invention relates to an artificial marble plate, and more particularly to an artificial marble plate having a laminated pattern on a peripheral surface.

  Artificial marble boards that can give a sense of quality at a relatively low cost may be used for washing counters and kitchen counters. A conventional artificial marble board is formed into a predetermined shape using a mold using a transparent thermosetting resin such as a thermosetting polyester resin or an acrylic resin as a base material, as disclosed in Patent Document 1, for example. . In addition to various pigments and dyes, a marble pattern is imparted by mixing colorants such as colored thermoplastic resin particles.

JP 2011-178151 A

  However, in the conventional artificial marble board, a colorant is mixed with a synthetic resin as a base material in order to give a marble pattern, but it is difficult to control the pattern. In other words, a rough marble pattern can be designed, but there are variations in the actual marble pattern, and it is almost impossible to accurately design the marble pattern. Moreover, in extreme terms, it is only necessary to have a marble pattern appearing on the surface, and it is only necessary to have a marble pattern with a colorant on both the front and back surfaces and the surface layer part of the peripheral surface. Is uniformly mixed. In this case, since the colorant is also present inside that is not visible from the outside, the material cost is wasted. Furthermore, some natural marbles have a laminate pattern in cross section, but it has been extremely difficult to accurately express the laminate pattern with conventional artificial marble plates.

  Moreover, since the conventional artificial marble board is a resin molded product, it has never been favorable for the global environment such as consumption of finite fossil resources and global warming due to carbon dioxide generated when incinerated and discarded. Moreover, since the conventional artificial marble board is a resin molded product, a mold is essential for the molding, and the production equipment cost increases. Further, a high degree of control is required to obtain a near net shape shape that is accurately formed into a shape defined by a mold.

  Accordingly, the present invention solves the above-described problems, and provides an artificial marble plate that can be easily designed with a marble pattern, can reliably express a laminated pattern on the peripheral surface, and has low cost and environmental load. Objective.

  As a means for that purpose, the artificial marble board of the present invention is formed by alternately laminating a plurality of bleached kraft paper layers and decorative paper layers in a state where both front and back surfaces are decorative paper layers. The bleached kraft paper layer has a thickness of 2 mm or less and a total light transmittance of 30 to 90%, and the decorative paper layer has a total light transmittance of less than 30%.

  The bleached kraft paper layer and the decorative paper layer are each preliminarily impregnated with a thermosetting resin, and the bleached kraft paper layer and the decorative paper layer are integrated by hot pressing.

  The “bleached kraft paper” in the present invention means bleached kraft paper defined in JIS P0001. The “total light transmittance” in the present invention means a total light transmittance measured in accordance with JIS K 7150. In the present invention, “OO to XX” indicating a numerical range means a range including the lower limit and the upper limit. Therefore, if it is expressed accurately, it will be “XX or more and XX or less”.

  The artificial marble board according to the present invention is formed by alternately laminating a plurality of bleached kraft paper layers and decorative paper layers, so that a laminated pattern can be surely expressed on the peripheral surface. At this time, by appropriately adjusting the thickness of each exposed kraft paper layer, the laminated pattern can be easily and reliably designed such as a uniform laminated pattern with a uniform interval (pitch of each layer) or an irregular laminated pattern. be able to. On the other hand, since the decorative paper layers are arranged on the front and back surfaces, a marble pattern on both sides of the artificial marble board can be obtained by embedding a colorant such as a pigment on the decorative paper layers on both sides of the front and back or by ink printing. Can be easily and reliably designed. On the other hand, the decorative paper layer located in the intermediate layer does not need to be given a unique marble pattern.

  In addition, in the artificial marble board of the present invention, the total light transmittance of the exposed kraft paper layer is 30 to 90%, and the total light transmittance of the decorative paper layer is less than 30%. That is, light (particularly visible light) incident on the artificial marble board hardly transmits the decorative paper layer, but is exposed and allowed to transmit the kraft paper layer. According to this, visible light that enters the inside from one surface of the artificial marble board (the surface corresponding to the mouthpiece in the case of wood board) is transmitted through each exposed kraft paper layer while being reflected by each decorative paper layer. By jumping out from the other surface, the peripheral surface pattern of the artificial marble board can be visually recognized. At this time, since the visible light transmitted through each exposed kraft paper layer is repeatedly reflected by each decorative paper layer, it becomes a similar color close to each decorative paper layer. This effect is higher if the thickness of each exposed kraft paper layer is 2 mm or less. Thereby, since the originally exposed white kraft layer is visually recognized as having the same color as the decorative paper layer, the sense of unity of the laminated pattern is increased and the design is improved. In addition, since there is no need for a colorant to bother and color the exposed kraft paper layer, the material cost can be reduced. Further, gradation can be given to the laminated pattern on the peripheral surface by changing the color of each decorative paper layer in stages.

  In addition, the artificial marble board of the present invention is basically composed of decorative paper and bleached kraft paper, and uses plant-derived materials, so the environmental burden can be reduced. Specifically, by using plant-derived materials, the amount of synthetic resin that is a fossil resource-derived material can be greatly reduced. This is also advantageous for the problem of increased carbon dioxide. In other words, carbon dioxide generated when fossil resource-derived materials are incinerated simply increases the total amount of carbon dioxide on the earth. However, when plant-derived materials are incinerated, plants take in the growth process. This is because the carbon dioxide that has been discharged is only returned to the atmosphere, and the total amount of carbon dioxide on the earth remains unchanged (carbon neutral).

  Moreover, the artificial marble plate of the present invention only needs to be hot-pressed, that is, press-molded, and does not require a mold for molding the resin, so that the production equipment cost can be reduced. Further, since the decorative paper layer and the exposed kraft paper layer are integrated with a binder resin, it is advantageous in terms of strength over an artificial marble plate made of a conventional resin molded product. Therefore, even if the thickness is relatively small, good strength can be ensured, leading to weight reduction. In addition, since there is no restriction on the size or the like depending on the mold, it is possible to easily meet various user demands by making an arbitrary thickness or cutting to an arbitrary size.

It is a model side view of an artificial marble board. It is a principal part expansion schematic sectional drawing which shows the light transmission principle. It is the surrounding surface photograph of the artificial marble board with a uniform laminated pattern. It is the surrounding surface photograph of the artificial marble board with the laminated pattern with gradation. It is a surrounding surface photograph of a natural marble board.

  The present invention is described in detail below. As shown in FIG. 1, the artificial marble board 10 of the present invention is formed by alternately laminating a plurality of exposed kraft paper layers 30 and decorative paper layers 20 in a state where both front and back surfaces become decorative paper layers 20.

[Decorated paper layer]
The decorative paper layer 20 is paper on which a desired color is given by making a pigment or dyeing with a dye. Further, if necessary, a pattern peculiar to marble can be applied by gravure printing or the like. When a pattern peculiar to marble is applied by gravure printing or the like, it may be printed on at least the decorative paper layer 20s on both the front and back surfaces, and is not necessarily printed on the decorative paper layer 20m of the intermediate layer. This is because even if printing is performed on the decorative paper layer 20m of the intermediate layer, the printed pattern cannot be visually recognized from the outside, and thus it is useless. Therefore, it is preferable to print only on the front and back decorative paper layers 20s and not on the intermediate decorative paper layer 20m. In addition, when the marble pattern peculiar to the decorative paper layer 20s on both the front and back sides is printed, it is preferable to provide a surface protective layer in order to prevent the pattern from being deteriorated due to friction. Examples of the surface protective layer in this case include thin paper having transparency and a transparent resin layer.

  As shown in FIG. 1, each decorative paper layer 20 may basically be composed of a single decorative paper 20 a. Although a plurality of decorative papers 20a may be laminated, it is preferable that the thickness is smaller than at least the exposed kraft paper layer 30. This is because if the thickness of the decorative paper layer 20 is exposed and is larger than the kraft paper layer 30, a laminated pattern is exhibited but it is difficult to form a laminated pattern such as natural marble. The thickness of the decorative paper layer 20 is specifically about 0.01 to 1.0 mm, preferably about 0.05 to 0.5 mm, and more preferably about 0.1 to 0.3 mm. The thickness of each decorative paper layer 20 may be uniform or may be different.

The decorative paper layer 20, the basis weight is preferred to use 45~160g / ^{m 2} about decorative paper, 50~140g / ^{m 2} about the decorative paper is more preferable, 60~120g / ^{m 2} about decorative paper Is more preferable. If the basis weight is too low, the total light transmittance tends to be higher than necessary. On the other hand, if the basis weight is too high, it becomes difficult to adjust the thickness of the artificial marble plate 10 and the cost becomes high, which is uneconomical. The ash content of the decorative paper layer 20 is preferably about 8 to 55% by weight, more preferably 10 to 55% by weight, and still more preferably 15 to 50% by weight. If the amount of ash is too low, the total light transmittance tends to be higher than necessary. On the other hand, if the amount of ash is too high, it becomes difficult to accurately color the desired color on the decorative paper layer 20. As used herein, “ash” means ash measured in accordance with JIS P 8128.

  In addition, the total light transmittance of the decorative paper layer 20 is at least less than 30%, preferably less than 25%, more preferably less than 20%. If the total light transmittance of the decorative paper layer 20 is 30% or more, the light incident on the artificial marble board 10 cannot be effectively reflected by the decorative paper layer 20, and the design of the peripheral surface of the artificial marble board 10 is deteriorated. Specifically, the bleached kraft paper layer 30 cannot appear to be similar in color to the decorative paper layer 20 (hereinafter, the apparent color of the bleached kraft paper layer 30 is referred to as “pseudo color”). The sense of unity of the laminated pattern is reduced.

[Exposed Kraft Paper Layer]
Generally, there are two types of kraft paper: unbleached kraft paper and bleached kraft paper. However, in the artificial marble board 10 of the present invention, bleached kraft paper with high whiteness is used. use. Thereby, the pseudo color of the exposed kraft paper layer 30 tends to be similar to the color of the decorative paper layer 20, and the color difference is also reduced.

  As shown in FIG. 1, each exposed kraft paper layer 30 is basically constituted by laminating a plurality of exposed kraft papers 30a, but can also be constituted by a single exposed kraft paper 30a. . The number of laminated layers is appropriately adjusted according to the thickness of the target exposed kraft paper layer 30. The thickness of the bleached kraft paper layer 30 is preferably as small as possible within a range larger than the decorative paper layer 20. This is because the pseudo color of the bleached kraft paper layer 30 tends to be similar to the color of the decorative paper layer 20, and the difference in color is also reduced. Specifically, the thickness of the exposed kraft paper layer 30 is at least 2 mm or less, preferably 1.8 mm or less, more preferably 1.5 mm or less, and even more preferably 1.2 mm or less. The lower limit of the thickness of the exposed kraft paper layer 30 may be 0.2 mm or more, preferably 0.5 mm or more, more preferably 0.7 mm or more. It should be noted that the thickness of each exposed kraft paper layer 30 may be uniform or may be different.

The ash content of the bleached kraft paper layer 30 (including a white agent such as titanium oxide) is preferably 3% by weight or less. This is because if the ash content exceeds 3% by weight, the total light transmittance decreases. The basis weight of the bleached kraft paper layer 30 is preferably about 100 to 250 g / ^{m 2,} more preferably about 120~230g / ^{m 2,} about 140~200g / ^{m 2} is more preferred. If the basis weight of the exposed kraft paper layer 30 is too small, the number of laminated sheets increases in order to obtain a desired thickness, and the productivity decreases in the resin impregnation step. On the other hand, if the basis weight is too large, the total light transmittance tends to decrease.

  In addition, the total light transmittance of the bleached kraft paper layer 30 is 30% or more, preferably 50% or more, more preferably 60% or more. Thereby, the light incident on the artificial marble board 10 is exposed and easily transmitted through the kraft paper layer 30, and as a result, the pseudo color of the exposed kraft paper layer 30 can be a similar color close to the color of the decorative paper layer 20. it can. On the other hand, the upper limit of the total light transmittance in the exposed kraft paper layer 30 is 90%. If it exceeds 90%, the diffuse reflection of light does not occur in the exposed kraft paper layer 30 and the transmitted light does not have the same color as the decorative paper layer 20.

[Artificial marble board]
The artificial marble board 10 of the present invention is formed by hot pressing (hot press molding) in a state in which a plurality of decorative paper layers 20 and exposed kraft paper layers 30 are alternately laminated, and are integrated by a binder resin. The number of intermediate layers to be laminated is not particularly limited, and may be appropriately adjusted according to the target thickness of the artificial marble board 10. The thickness of the artificial marble plate 10 may be appropriately adjusted according to the purpose of use and the place of use, but is at least 0.5 mm, preferably 5 mm, more preferably 10 mm. When the thickness of the artificial marble plate 10 is relatively thin (for example, less than 5 mm), the artificial marble plate 10 may be attached to the surface of the core made of wood or the like. If the thickness of the artificial marble board 10 is 5 mm or more, the strength as an independent member can be secured, so that it can be used alone as a building material such as a counter top board. On the other hand, the upper limit of the thickness of the artificial marble plate 10 is not particularly limited. However, even if the thickness is too large, the material cost and weight are only increased, and therefore, it may be 50 mm or less, preferably 35 mm or less, more preferably 20 mm or less.

  The binder resin for integrating (adhering) the layers is not particularly limited as long as it is a transparent or translucent thermosetting resin. Specifically, melamine resin, diallyl phthalate resin, epoxy resin, polyester resin, vinyl ester resin, acrylic resin, or the like can be used. Among these, melamine resin is most preferable in terms of transparency, productivity, cost, and the like. The thermosetting resin as the binder resin is preferably impregnated in each exposed kraft paper layer 30 or decorative paper layer 20 in advance. Although it is possible to impregnate after laminating each layer, the resin impregnation rates of the central portion and the surface layer portion are different, and it is assumed that the layers are not uniformly impregnated. The impregnation method is not particularly limited, and known methods such as dipping, coating, and spraying can be used.

  In the decorative paper layer 20 and the bleached kraft paper layer 30, the resin adhesion rate when impregnated with the thermosetting resin is preferably 30 to 55% by weight, more preferably 35% by weight or more and less than 50% by weight, and 38 to 48% by weight. % Is more preferable. The volatile content is preferably 3 to 9% by weight, and more preferably 4 to 7% by weight. When the resin adhesion rate is less than 30% by weight or the volatile content is less than 3% by weight, it is difficult to ensure adhesiveness and strength because the thermosetting synthetic resin hardly spreads to each layer. Further, the total light transmittance of the bleached kraft paper layer 30 tends to decrease, and the same color as the decorative paper layer 20 tends to disappear. On the other hand, if the resin adhesion rate exceeds 55% by weight, surplus thermosetting resin flows out during hot-press molding, and burrs are easily generated, which is uneconomical in terms of cost. Moreover, when the resin adhesion rate is 50% by weight or more, the relative proportion of plant-derived materials becomes lower. When the volatile content exceeds 9% by weight, each layer tends to block before hot pressing. Blocking means that the layers adhere to each other before heating or pressurization.

  In addition, the resin adhesion rate and the volatile matter in each layer may be the same or different as long as they are within the above range. For example, the resin adhesion rate of the front and back decorative paper layers 20s is preferably slightly higher than the resin adhesion rate of the intermediate decorative paper layer 20m and the exposed kraft paper layer 30. This is because the fluidity of the resin on the front and back decorative surfaces can be improved during molding, and nest entry can be prevented. In this case, the resin adhesion rate on the front and back decorative paper layers 20s may be 48 to 55% by weight.

The “resin adhesion rate” is the content ratio of the resin in each layer and is calculated by the following calculation formula (1). Further, the “volatile content” is a content ratio of volatile components in each layer. The weight-impregnated paper was left in a dryer at 120 ° C. ± 2 ° C. for 20 minutes, and the weight of the impregnated paper after drying was measured. Based on the result, it is calculated by the following calculation formula (2).
Resin adhesion rate (% by weight) = ((impregnated paper weight−base paper weight) / impregnated paper weight) × 100 (1)
Volatile content (% by weight) = ((impregnated paper weight−absolutely impregnated paper weight) / impregnated paper weight) × 100 (2)

  The artificial marble board 10 of the present invention is easy to design a marble pattern on both the front and back sides, and has a laminated pattern on the peripheral surface, which is a kind of natural marble that is a pseudo object compared to a conventional resin artificial marble board. As the width expands, the sense of quality also improves. Examples of the natural marble that is a simulated object include red travertine, onyx, serpegante, travertine, perlino, rossomaniyaboski, perlino rosate, and sandstone.

  The artificial marble board 10 of the present invention can be widely used as a building material such as a wash counter, a kitchen counter, a toilet booth, a table top board, a wall material, and a floor material.

[Production method]
As described above, the artificial marble board 10 of the present invention is formed by hot pressing in a state in which a plurality of decorative paper layers 20m and exposed kraft paper layers 30 are alternately laminated between front and back decorative paper layers 20s. Press forming). As for the heating conditions, the temperature of the press surface is preferably about 120 to 150 ° C. When the temperature of the press surface is less than 120 ° C., the thermosetting synthetic resin may not be sufficiently cured. On the other hand, when the temperature of the press surface exceeds 150 ° C., the thermosetting synthetic resin tends to yellow, and the artificial marble plate 10 tends to become brittle. Moreover, it is preferable that pressurization conditions are about 5-12 Mpa. If the pressing pressure is less than 5 MPa, the adhesiveness and density are not sufficiently uniform. On the other hand, if the pressing pressure exceeds 12 MPa, the density of the artificial marble plate 10 becomes too high and the thickness becomes insufficient.

[Function and effect]
The artificial marble board 10 of the present invention has the above-described configuration, and thus has the following effects. Specifically, as shown in FIG. 2, incident light (particularly visible light) L ₀ incident on the peripheral surface of the artificial marble board 10 (a surface corresponding to a wooden face in the case of a wooden board) is L _0. Since the total light transmittance of the exposed kraft paper layer 30 is high, the total light transmittance of the exposed kraft paper layer 30 passes through each exposed kraft paper layer 30. At this time, the incident light L ₀ is diffused while colliding with the fibers of the exposed kraft paper layer 30, colliding with the upper and lower decorative paper layers 20 and being diffusely reflected. Then, by passing through while repeating such irregular reflection, the transmitted light L ₁ becomes false-color close to the decorative paper layer 20. Thereby, the effect that the sense of unity of the peripheral surface pattern is increased and the appearance is excellent is obtained.

  If the color tone of each decorative paper layer 20 is unified, a uniform laminated pattern as shown in FIG. 3 is obtained. However, by changing the color tone of each decorative paper layer 20 in stages, as shown in FIG. It is also possible to apply a layered pattern with a gradation.

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

Example 1
A pink decorative paper having a basis weight of 100 g / m ² mixed with 27% by weight of pigment and titanium oxide was impregnated with a modified melamine resin initial condensate and dried. As a result, a melamine resin-impregnated decorative paper having a resin adhesion rate of 50% by weight and a volatile content of 4.5% by weight was prepared to obtain a front and back melamine resin-impregnated decorative paper (S). Similarly, a peach-colored decorative paper having a basis weight of 100 g / m ² is impregnated with a modified melamine resin initial condensate, and a melamine resin-impregnated decorative paper for an intermediate layer having a resin adhesion rate of 44 wt% and a volatile content of 4.5 wt% (M ) Subsequently, the bleached kraft paper having a basis weight of 200 g / m ² and an ash content of 0% was impregnated with the modified melamine resin initial condensate and then dried. As a result, a melamine resin-impregnated kraft paper having a resin adhesion rate of 44% by weight and a volatile content of 8% by weight was produced. In order from the bottom, 1 sheet of melamine resin-impregnated decorative paper (S) for front and back, and then 6 sheets of kraft paper impregnated with melamine resin are overlapped. One sheet of melamine resin-impregnated decorative paper (M) for the intermediate layer is stacked thereon, and six sheets of melamine resin-impregnated kraft paper are stacked thereon. In this way, seven sets of decorative paper layers composed of one melamine resin-impregnated decorative paper (M) and six exposed kraft paper layers composed of six melamine resin-impregnated kraft papers were laminated alternately, and the top and bottom melamines were on top. A laminate was prepared by superposing one sheet of resin-impregnated decorative paper (S). The laminate was sandwiched between stainless mirror plates and pressed while being heated by a press. The pressurizing conditions at this time are a press surface temperature of 145 ° C., a press pressure of 8 MPa, and a hot press time of 60 minutes. After cooling this to room temperature, it was removed from the press machine to obtain a 10 mm thick artificial marble plate.

(Example 2)
10 mm in the same manner as in Example 1 except that each bleached kraft paper layer was composed of 8 sheets of melamine resin-impregnated kraft paper and five layers of melamine resin-impregnated decorative paper layers and bleached kraft paper layers were alternately laminated as an intermediate layer. A thick artificial marble board was obtained.

(Example 3)
All decorative paper layers including both front and back surfaces were mixed with 39% by weight of pigment and titanium oxide (a yellow decorative paper having a basis weight of 100 g / m ² was impregnated with a modified melamine resin initial condensate and a resin adhesion rate of 48 A sheet of makeup-impregnated paper with a weight percent of 4.5% and a volatile content of 4.5% by weight was used, and each exposed kraft paper layer was composed of three melamine resin-impregnated kraft papers, with an intermediate layer of melamine resin-impregnated decorative paper layer. A 7 mm thick artificial marble board was obtained in the same manner as in Example 1 except that nine sets of kraft paper layers were alternately laminated.

Example 4
A light-colored decorative paper having a basis weight of 100 g / m ² mixed with 28% by weight of pigment and titanium oxide is impregnated with a modified melamine resin initial condensate to give a resin adhesion rate of 48% by weight and a volatile content of 4.5% by weight of melamine resin. An impregnated cosmetic impregnated paper was obtained. Fresh water of the same basis weight (mixed with 33% by weight of pigment and titanium oxide), pale yellow (mixed with 31% by weight of pigment and titanium oxide), yellow (mixed with 28% by weight of pigment and titanium oxide), yellow green (pigment) And 24% by weight of titanium oxide mixed paper) were impregnated with the same amount of melamine resin to obtain a cosmetic impregnated paper. Each bleached kraft paper layer is composed of 3 sheets of kraft paper impregnated with melamine resin, and in order from the bottom, 1 pair of light blue makeup impregnated paper and 2 layers of bleached kraft paper layers are laminated alternately and exposed to 1 sheet of fresh light blue makeup impregnated paper Laminate two sets of kraft paper layers alternately, stack one pair of pale yellow makeup impregnated paper and one exposed kraft paper layer, and laminate two pairs of alternating peach yellow makeup impregnated paper and one exposed kraft paper layer Then, one set of yellow-green makeup impregnated paper and an exposed kraft paper layer were laminated, and a total of eight pairs were laminated. A laminate was prepared by superposing one sheet of yellow-green makeup impregnated paper on the top, and an artificial marble plate having a gradation pattern of 6.5 mm in thickness was obtained in the same manner as in Example 1.

(Comparative Example 1)
An artificial marble board was produced in the same manner as in Example 1 except that each bleached kraft paper layer was composed of 10 melamine resin-impregnated kraft papers.

(Comparative Example 2)
An artificial marble board was produced in the same manner as in Example 1 except that the ash content of the bleached kraft paper was changed to 4%.

(Comparative Example 3)
An artificial marble board was produced in the same manner as in Example 1 except that a brown decorative paper having a basis weight of 80 g / m ² mixed with 5% by weight of pigment and titanium oxide was used.

  In the obtained artificial marble plates of Examples and Comparative Examples, the thickness of each exposed kraft paper layer and the total light transmittance of each decorative paper layer and each exposed kraft paper layer were measured. The results are shown in Table 1. Moreover, the outer peripheral part of each artificial marble board was cut | disconnected at an angle of 45 degrees, and the color tone of the surrounding surface was observed visually. The results are also shown in Table 1. Moreover, the surrounding surface photograph of the artificial marble board of Example 3 is shown in FIG. 3, and the surrounding surface photograph of the artificial marble board of Example 4 is shown in FIG. Further, when the strength of the artificial marble plate of Example 1 was measured using a universal material tester Strograph V20-C type manufactured by Toyo Seiki Co., Ltd., the bending strength was 116 MPa and the bending elastic modulus was 11,037 MPa.

  From the results in Table 1, in Examples 1 to 4, the pseudo color of each kraft paper layer is the same color as the decorative paper layer, so that a sense of unity was obtained in the laminated pattern on the peripheral surface. On the other hand, Comparative Example 1 in which the bleached kraft paper layer has a large thickness, Comparative Example 2 in which the bleached kraft paper layer has a low total light transmittance, and Comparative Example 3 in which the decorative paper layer has a high total light transmittance, The color tone was different from the color tone of the decorative paper layer, and there was no sense of unity in the laminated pattern.

10 artificial marble board 20 decorative paper layer 20a decorative paper 20s front and back decorative paper layer 20m intermediate decorative paper layer 30 exposed kraft paper layer 30a exposed kraft paper L ₀ incident light L ₁ transmitted light

Claims (2)

In a state where both front and back sides become a decorative paper layer, a plurality of bleached kraft paper layers and decorative paper layers are laminated alternately,
The bleached kraft paper layer has a thickness of 2 mm or less and a total light transmittance of 30 to 90%.
The total light transmittance of the decorative paper layer is less than 30%;
An artificial marble board with a laminated pattern on the circumference. Each of the bleached kraft paper layer and the decorative paper layer is impregnated with a thermosetting resin in advance,
The artificial marble board according to claim 1, wherein each bleached kraft paper layer and decorative paper layer are integrated by hot pressing.