JP3212434U - panel - Google Patents

Abstract

[PROBLEMS] To be used at exhibitions because it has flameproofness, because it is excellent in crack resistance and returnability, it can be used and reused over a long period of time, and it is easy to construct because of its excellent flexibility. A synthetic resin panel is provided. The synthetic resin sheet is made of a synthetic resin sheet having a thickness of 1 to 5 mm and has a flameproof property. The synthetic resin sheet is laminated and bonded to a core layer and at least one surface of the core layer via an intermediate layer. And the ratio of the thickness of the core layer to the total thickness of the synthetic resin sheet 1 is 50% or more, and the base resin of the core layer 2 and the intermediate layer 4 is a polystyrene resin. And a polypropylene resin, the base resin of the surface layer 3 is a polypropylene resin, and the polystyrene resin accounts for 20 to 70% by weight of 100% by weight of the mixed resin constituting the core layer 2 Each layer of the synthetic resin sheet 1 includes a brominated flame retardant. [Selection] Figure 1

Description

  The present invention relates to a panel, and more particularly, to a panel having excellent flame resistance, crack resistance, and deflection resistance.

  Conventionally, wood-based plywood has been used as a panel for partitions used in exhibitions. A panel used in a place where an unspecified number of people gather such as an exhibition is required to have a flameproof property, and a panel subjected to a flameproofing treatment using a flameproofing agent is used.

However, the conventional flameproof plywood has a problem that corners are easily chipped at the time of construction, and cracks are gradually generated even during use, so that crack resistance is low and it is difficult to use for a long time. In addition, output paper (printed material) is often affixed for exhibitions, and it is difficult to remove the output paper after use, so it is difficult to remove, and in addition, a large amount of adhesive remains on the plywood surface. There was a problem that it took time and effort.

  On the other hand, the present applicant has first solved a problem of the conventional flameproof plywood and proposed a synthetic resin panel that can be used for a long time at an exhibition (utility model registration No. 3203943). The panel having flame resistance described in Utility Model Registration No. 3203943 is composed of a synthetic resin sheet having a thickness of 1 to 5 mm, and the synthetic resin sheet is a core having a polypropylene resin as a base resin. A multilayer structure having a layer and a surface layer having a polypropylene resin as a base resin, located on the outermost surface side of at least one side of the synthetic resin sheet, and each layer of the synthetic resin sheet is brominated as a flame retardant Including a flame retardant and blending a specific amount of the flame retardant in each layer makes it difficult to burn, corners are difficult to break, and has excellent returnability, and can be suitably used as a partition panel or exhibition panel for exhibitions, etc. It was.

  The synthetic resin sheet described in the Utility Model Registration No. 3203943 is excellent in flame resistance and crack resistance, and the load at the time of 5 mm deflection based on JIS K7171: 2008 is 55 N / 25 mm or more. Because of its good deflection resistance, its workability is also excellent. On the other hand, when constructing large panels at exhibitions, etc., or when used as partitioning panels or exhibition panels for a long time, the bending resistance is higher, especially in the extrusion direction of synthetic resin sheets. In some cases, a panel having high properties is required.

  An object of the present invention is to provide a panel that has excellent flame resistance, crack resistance, and returnability, and has improved flex resistance over conventional ones.

According to the present invention, the following panel is provided.
[1] A panel made of a synthetic resin sheet having a thickness of 1 to 5 mm and having flame resistance,
The synthetic resin sheet is a multilayer sheet having a core layer and a surface layer laminated and bonded to at least one surface of the core layer via an intermediate layer,
The ratio of the thickness of the core layer to the total thickness of the synthetic resin sheet is 50% or more,
The base resin of the core layer and the intermediate layer is a mixed resin of polystyrene resin and polypropylene resin,
The base layer resin of the surface layer is a polypropylene resin,
The weight ratio of polystyrene resin to polypropylene resin in the core layer is 20 to 70% by weight of polystyrene resin and 30 to 80% by weight of polypropylene resin (however, the total of polystyrene resin and polypropylene resin is 100% by weight). %)), And
Each layer of the synthetic resin sheet is a panel containing a brominated flame retardant as a flame retardant.
[2] The weight ratio between the polystyrene resin and the polypropylene resin in the intermediate layer is 10 to 70% by weight of the polystyrene resin and 30 to 90% by weight of the polypropylene resin (however, the polystyrene resin and the polypropylene resin The panel according to [1], wherein the total is 100% by weight.
[3] The weight ratio of the polystyrene resin and the polypropylene resin in the core layer is 50 to 70% by weight of polystyrene resin and 30 to 50% by weight of polypropylene resin (however, the polystyrene resin and the polypropylene resin The panel according to [1] or [2], wherein the total is 100% by weight.
[4] The panel according to any one of [1] to [3], wherein a weight ratio of the polystyrene resin in the intermediate layer is lower than a weight ratio of the polystyrene resin in the core layer.
[5] The amount of the flame retardant in the core layer and the intermediate layer is 8 to 25 parts by weight with respect to 100 parts by weight of the base resin, and the amount of the flame retardant in the surface layer is the base resin. The panel according to any one of [1] to [4], which is 5 to 15 parts by weight with respect to 100 parts by weight.
[6] The panel according to [5], wherein a blending ratio of the flame retardant in the core layer and the intermediate layer is higher than a blending ratio of the flame retardant in the surface layer.
[7] The brominated flame retardant of the core layer includes a brominated flame retardant having a melting point of 200 ° C. or lower, and the brominated flame retardant of the surface layer includes a brominated flame retardant having a melting point of 250 ° C. or higher. The panel according to any one of [1] to [6].
[8] The panel according to any one of [1] to [7], wherein each layer of the synthetic resin sheet further contains antimony trioxide.
[9] The panel according to any one of [1] to [8], wherein a load at the time of 5 mm deflection based on JIS K7171: 2008 in the extrusion direction of the synthetic resin sheet is 95 N / 25 mm or more.
[10] The [1] to [1], wherein the synthetic resin sheet is a multilayer sheet having a five-layer structure including the core layer and the surface layer laminated and bonded to both surfaces of the core layer via the intermediate layer. [9] The panel according to any one of [9].

The panel of the present invention comprises a synthetic resin sheet having a thickness of 1 to 5 mm, and the synthetic resin sheet has a core layer and a surface layer laminated and bonded to at least one surface of the core layer via an intermediate layer. The core layer and intermediate layer base resin is a mixed resin of polystyrene resin and polypropylene resin, the surface layer base resin is polypropylene resin, and the core layer with respect to the total thickness of the synthetic resin sheet The ratio of the thickness of the resin is not less than a specific value, the weight ratio of the polystyrene resin and the polypropylene resin in the core layer is in a specific range, and each layer of the synthetic resin sheet includes a brominated flame retardant as a flame retardant, thereby providing flameproofing. Excellent in cracking resistance, crack resistance, returnability, and deflection resistance. Therefore, the panel of the present invention can be suitably used as a partition panel or an exhibition panel for an exhibition or the like.

FIG. 1 is a longitudinal sectional view of a synthetic resin sheet 1.

Hereinafter, the panel of this invention is demonstrated in detail using drawing.
The panel of the present invention comprises a synthetic resin sheet 1, and as shown in FIG. 1, the synthetic resin sheet 1 is composed of a core layer 2, a surface layer 3 located on the outermost surface side, and between the core layer and the surface layer. And has a multilayer structure having an intermediate layer 4 for bonding the core layer and the surface layer. The surface layer 3 can be provided only on one side of the synthetic resin sheet 1 or can be provided on both sides. From the viewpoint of suppressing warping of the synthetic resin sheet 1, the surface layer 3 is preferably provided on both surfaces. Hereinafter, the case where the surface layer 3 is provided on both surfaces of the core layer 2 will be described.
1 is a longitudinal sectional view of the synthetic resin sheet 1. In FIG. 1, 1 is a synthetic resin sheet, 2 is a core layer, 3 is a surface layer, and 4 is an intermediate layer.

  The base resin of the core layer 2 is a mixed resin of a polystyrene resin and a polypropylene resin. Examples of the polystyrene resin include polystyrene, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, styrene-acrylic acid copolymer, styrene-maleic anhydride copolymer, and the like. Examples of polypropylene resins include polypropylene homopolymers, propylene-ethylene copolymers, propylene-butene copolymers, propylene-ethylene-butene copolymers. In the range where the object and effect of the present invention are achieved, the polystyrene resin and the polypropylene resin may include other polymers.

The base resin of the core layer 2 is a mixed resin of a polystyrene resin and a polypropylene resin. The weight ratio of the polystyrene resin and the polypropylene resin in the core layer 2 is 20 to 70% by weight of the polystyrene resin and 30 to 80% by weight of the polypropylene resin (however, the total of the polystyrene resin and the polypropylene resin) Is 100% by weight.).
While the base resin of the synthetic resin sheet 1 is composed of the above mixed resin, and the weight ratio of the polystyrene resin and the polypropylene resin of the mixed resin is within the above range, the synthetic resin sheet 1 has the flexibility and resistance to resistance. It will be excellent in both cracking properties. Moreover, the flatness of the synthetic resin sheet 1 can be improved.
If the ratio of the polystyrene resin constituting the mixed resin is too high, the flex resistance is excellent but the crack resistance is low (Comparative Example 2). If the ratio of the polystyrene-based resin is too low, the bending resistance is lowered, and there is a possibility that a problem occurs in workability (Comparative Example 1). From this viewpoint, the weight ratio of the polystyrene resin and the polypropylene resin in the core layer 2 is 50 to 70% by weight of the polystyrene resin and 30 to 50% by weight of the polypropylene resin (however, the polystyrene resin and the polypropylene resin Is preferably 100% by weight).

The core layer 2 can contain a colored colorant. There is no restriction on the color. However, it may be uncolored or white. As a case where the core layer 2 is colored, for example, a case where a polystyrene resin or a polypropylene resin constituting the base resin of the core layer 2 is mainly composed of a colored recycled polystyrene resin or recycled polypropylene resin. It is done. By using recycled resin, the price of the panel can be reduced. As long as the recycled resin can produce a sheet, it can contain other resins than the polystyrene resin and the polypropylene resin.
In the present specification, the main component refers to a resin component contained in a resin in an amount of 50% by weight or more.

  The surface layer 3 is located on both outermost surfaces of the synthetic resin sheet 1, and the main component of the base resin is a polypropylene resin. Examples of the polypropylene resin include those similar to those constituting the core layer 2. By providing the surface layer 3 on the outermost surface side of the core layer 2, even when the core layer 2 is made of recycled polystyrene resin or recycled polypropylene, for example, the surface layer 3 has cosmetic properties and design properties. By having it, the synthetic resin sheet 1 can be made beautiful. Moreover, the output paper affixed on the panel can be peeled off efficiently.

  The surface layer 3 preferably contains an antistatic agent. When the antistatic agent is blended in the surface layer 3, an effect that dust is difficult to adhere is obtained, and an effect that the output paper is more easily peeled off is also obtained. The antistatic agent is not particularly limited as long as the surface layer 3 can be formed and dust can be prevented from being attached. For example, a surfactant can be preferably used. Surfactants include glycerin fatty acid esters, alkyldiethanolamine fatty acid esters, stearyl alcohol and mixtures thereof.

  The blending amount of the antistatic agent is preferably about 0.8 to 3.0 parts by weight, more preferably 100 parts by weight of the base resin constituting the surface layer 3, although it depends on the kind of the antistatic agent. 1.0 to 2.5 parts by weight. When the blending amount is within the above range, a sufficient antistatic effect can be obtained with an antistatic agent having an optimum blending amount.

  The surface layer 3 can contain a white pigment and is preferably colored white. Examples of white pigments include titanium oxide (titanium white), zinc white (zinc white), lithopone, and lead white.

  When a white pigment is blended in the surface layer 3, the yellowness (YI) based on JIS K7373: 2006 on the surface of the white synthetic resin sheet 1 is preferably 1 to 15, more preferably 3 to 10. . When the YI value is within the above range, dirt is hardly noticeable and returnable use is possible.

  The surface layer 3 can also be colored black. In order to make the surface layer 3 black, a black pigment or a black dye can be used. Black pigments include carbon black, oil smoke, plant black, bone charcoal, graphite and other carbon black pigments, iron oxides (magnetite type triiron tetroxide), copper and chromium composite oxides, copper, chromium and zinc. Examples thereof include oxide-based black pigments such as complex oxides. As the black dye, a commercially available one can be used.

  As the degree of black, L * a * b * L * of the colorimetric value is preferably 25 or less, more preferably 20 or less. If L * is within this range, the posted material can stand out as a black background.

  In addition, L * means the CIE1976 lightness index L * of the surface of the surface layer 3 based on JIS Z8771-4: 2013, and is a value measured in a C light source 2 degree visual field.

The synthetic resin sheet 1 of the present invention is configured as a multilayer sheet having a five-layer structure having an intermediate layer 4 between the core layer 2 and each surface layer 3 and between the core layer 2 and each surface layer 3. Similarly to the core layer 2, the intermediate layer 4 is preferably made of a mixed resin of a polystyrene resin and a polypropylene resin. The weight ratio of the polystyrene resin and the polypropylene resin in the intermediate layer 4 is 10 to 70% by weight of the polystyrene resin and 30 to 90% by weight of the polypropylene resin (however, the total of the polystyrene resin and the polypropylene resin is 100). % By weight). By providing the intermediate layer 4, not only the core layer 2 and the surface layer 3 are bonded, but also when the core layer 2 is a dark color such as black and the surface layer 3 is colored in a light color such as white, Even if the thickness of the surface layer 3 is reduced, color transparency can be prevented by increasing the thickness of the intermediate layer. By reducing the thickness of the surface layer 3, the amount of the antistatic agent used can be reduced.
From the viewpoint of improving the adhesion between the core layer 2 and the surface layer 3, the weight ratio of the polystyrene resin and the polypropylene resin in the intermediate layer 4 is 25 to 55% by weight of polystyrene resin and 45 to 75% by weight of polypropylene resin. (However, the total of the polystyrene resin and the polypropylene resin is 100% by weight.).

  The weight ratio of the polystyrene resin in the mid layer 4 is preferably lower than the weight ratio of the polystyrene resin in the core layer 2. When the weight ratio of the polystyrene resin in the intermediate layer 4 is lower than the weight ratio of the polystyrene resin in the core layer 2, the adhesion between the core layer 2 and the surface layer 4 can be made better.

  In the sheet 1 of the present invention, each layer includes a brominated flame retardant as a flame retardant. Moreover, it is preferable that each layer of the synthetic resin sheet 1 contains antimony trioxide further from a viewpoint of improving flameproofness.

The melting point of the brominated flame retardant contained in the core layer 2 is preferably 200 ° C. or less, more preferably 180 ° C. or less, and further preferably 150 ° C. or less. When the melting point of the brominated flame retardant of the core layer 2 is within the above range, even if the core layer 2 contains a polystyrene resin, the drip of the flame retardant component is promoted at the time of combustion, and sufficient flame resistance is stabilized. Can be secured. Further, the blending amount of the brominated flame retardant having a melting point of 200 ° C. or less in the flame retardant of the core layer 2 is preferably 30% by weight or more, more preferably 50% by weight, and 70% by weight or more. More preferably it is.
The melting point of the brominated flame retardant is a value measured based on JIS K7122: 1987.

  Specifically, as the flame retardant for the core layer 2, a mixed flame retardant of bis (hydroxy and / or alkoxyphenyl) sulfone derivative and antimony trioxide is preferably used. The weight ratio of the bis (hydroxy and / or alkoxyphenyl) sulfone derivative to antimony trioxide is preferably 3: 1.

The flame retardant used for the surface layer 3 preferably includes a flame retardant having a melting point of 250 ° C. or higher from the viewpoint of ensuring flame retardancy and suppressing discoloration. Further, the blending amount of the brominated flame retardant having a melting point of 250 ° C. or higher in the flame retardant of the surface layer 3 is preferably 30% by weight or more, more preferably 50% by weight, and 70% by weight or more. More preferably it is.
Specifically, a mixed flame retardant of ethylene bis (pentabromobenzene) and antimony trioxide is preferably used. The weight ratio of ethylenebis (pentabromobenzene) and antimony trioxide is preferably 3: 1.

From the viewpoint of ensuring sufficient flameproofness, the intermediate layer 4 also contains a flame retardant. As the flame retardant for the intermediate layer 4, the same material as the core layer 2 and the surface layer 3 can be used, but from the viewpoint of extrusion stability, it is preferable to contain a brominated flame retardant having a melting point of 250 ° C. or higher. . Further, the amount of the brominated flame retardant having a melting point of 250 ° C. or higher in the flame retardant of the intermediate layer 4 is preferably 30% by weight or more, more preferably 50% by weight, and 70% by weight or more. More preferably it is.
Specifically, a mixed flame retardant of ethylene bis (pentabromobenzene) and antimony trioxide is preferably used. The weight ratio of ethylenebis (pentabromobenzene) and antimony trioxide is preferably 3: 1.

  The compounding quantity of the flame retardant of the core layer 2 and the intermediate | middle layer 4 is 8-25 weight part with respect to 100 weight part of each base resin. When the blending amount is within the above range, a sufficient flameproofing property can be obtained with an optimal blending amount of the flame retardant. From such a viewpoint, the blending amount of the flame retardant in the core layer 2 and the intermediate layer 4 is preferably 10 to 20 parts by weight, more preferably 12 to 18 parts by weight with respect to 100 parts by weight of the respective base resin. preferable.

  The amount of the flame retardant in the surface layer 3 is 5 to 15 parts by weight, preferably 6 to 12 parts by weight, and more preferably 7 to 10 parts by weight with respect to 100 parts by weight of the base resin.

  In order to sufficiently ensure the flame resistance of the core layer 2 and the intermediate layer 4 containing the polystyrene resin, the blending concentration of the flame retardant in the core layer 2 and the intermediate layer 4 is larger than the blending concentration of the flame retardant in the surface layer 3. It is preferable.

You may mix | blend a compatibilizing agent with the core layer 2 and the intermediate | middle layer 4 as needed. By mix | blending a compatibilizing agent, the compatibility of a polystyrene resin and a polypropylene resin improves, and both resin can fully be mixed. The compatibilizer is preferably a styrene thermoplastic elastomer. The compounding amount of the compatibilizing agent for the core layer 2 and the intermediate layer 4 is 2 to 10 parts by weight with respect to 100 parts by weight of the respective base resin.

  In the synthetic resin sheet 1 of the present invention, it is preferable that at least one surface is textured, and it is more preferable that both surfaces are textured. When the surface of the synthetic resin sheet 1 is subjected to a textured process, the output paper can be easily peeled off after the exhibition is completed, so that the panel becomes returnable and easy to use.

  The arithmetic average roughness Ra of the textured surface is preferably 3 to 30 μm, more preferably 5 to 20 μm. When the arithmetic average roughness Ra is within the above range, it is possible to suppress the embossing irregularities from appearing on the surface of the attached output paper, and the appearance is excellent. In addition, the output paper is sufficiently adhered to the panel during use, and after use, the output paper can be efficiently peeled off after use, even after being promoted for crimping such as stacking and storage. Can do.

  The arithmetic average roughness Ra of the foamed plate surface in the present invention refers to the arithmetic average roughness Ra75 of the contour line measured in accordance with Appendix 2 of JIS B0601: 2013. As the surface roughness meter, those generally used can be used, and examples thereof include Surfcorder SE-30D, Surfcorder SE1700α manufactured by Kosaka Laboratory Ltd., and the like.

  The area ratio of the recesses on the textured surface is preferably 5 to 25%, more preferably 7 to 20%. When the area ratio of the recesses is within the above range, both the adhesion stability of the output paper and the ease of peeling can be achieved, and the panel has excellent returnability.

  The area ratio of the concave portions on the textured surface is measured by coloring the convex portions black and performing image processing.

  In addition, the wrinkle processing means that the surface irregularities of the molding roll are transferred to a softened sheet when the synthetic resin sheet 1 is manufactured, thereby forming a leather pattern, wood grain, rock grain, sand grain, plain texture, geometry on the surface. To form a pattern.

  The thickness of the synthetic resin sheet 1 of the present invention is 1 to 5 mm. If the thickness is too thin, the mechanical strength may be too low to be used as a panel, and if it is too thick, it may be too heavy and difficult to handle, or the cost may increase. From this viewpoint, the lower limit is preferably 2 mm, and the upper limit is preferably 4 mm.

  The ratio of the thickness of the core layer to the thickness of the entire synthetic resin sheet is 50% or more. When the ratio of the thickness of the core layer is too low, the bending resistance is lowered and there is a possibility that a problem may occur in the workability. From the above viewpoint, the ratio of the thickness of the core layer to the thickness of the entire synthetic resin sheet is preferably 70% or more.

  The thickness of the surface layer 3 is preferably 0.05 to 1 mm, more preferably 0.07 to 0.8 mm, and still more preferably 0.10 to 0.5 mm. When the thickness of the surface layer 3 is within the above range, it is possible to prevent cracking from the surface while ensuring the rigidity of the synthetic resin sheet 1. Moreover, the cosmetics and designability of the synthetic resin sheet 1 can be ensured. Furthermore, when using an antistatic agent, it can prevent that the compounding quantity of an antistatic agent increases.

  The thickness of the intermediate layer 4 is preferably 0.05 to 1 mm, more preferably 0.1 to 0.5 mm. When the thickness of the intermediate layer 4 is within the above range, the above-described anti-slipping effect and rigidity improvement effect can be sufficiently obtained.

  The ratio of the thickness per one side of the core layer 2 and the surface layer 3 is preferably 1: 1 to 98: 1, more preferably 2: 1 to 48: 1, still more preferably 5: 1 to 30: 1. When the ratio of the thicknesses of the core layer 2 and the surface layer 3 is within the above range, the rigidity of the synthetic resin sheet can be ensured and the design of the panel can be enhanced. In addition, a sufficient amount of recycled polystyrene resin or recycled polypropylene resin can be used for the core layer 2 to obtain a cost reduction effect.

  The shape of the synthetic resin sheet 1 is usually rectangular or square in plan view, and the length of one side is preferably 200 to 4000 mm, more preferably 500 to 3000 mm.

  The load when the synthetic resin sheet 1 is bent by 5 mm in the extrusion (MD) direction is preferably 95 N / 25 mm or more. When the load during bending is within the above range, the panel does not sag and good workability can be ensured. Moreover, it can prevent that a panel remove | deviates from a fixing jig after construction. From this point of view, the load during the deflection is more preferably 98 N / 25 mm or more, and still more preferably 100 N / 25 mm or more. The upper limit is approximately 200 N / 25 mm.

  In panel construction, rigidity in the extrusion (MD) direction is particularly required, but higher rigidity in the width (TD) direction is preferable. The lower limit is approximately 55 N / 25 mm, more preferably 60/25 mm, and even more preferably 65/25 mm.

  The load at the time of 5 mm deflection is measured according to JIS K7171: 2008. A test piece along the extrusion direction (MD) and the width direction (TD) is prepared, and the load at the time of 5 mm deflection is measured.

  The synthetic resin sheet 1 of the present invention can be produced by a conventionally known multilayer coextrusion method. The multilayer coextrusion method has a simple process and is preferable from the viewpoint of cost. Among the multilayer coextrusion methods, it is preferable to employ a method of laminating each layer by coextrusion into a plate shape using a flat die for coextrusion.

The panel of the present invention is made of the synthetic resin sheet 1 and can be suitably used for a wall panel. Wall panels are often large in size with a piece exceeding 1 m, and where the resistance to bending during construction is important, the synthetic resin sheet 1 of the present invention is difficult to bend as described above, and is therefore suitable for wall panels. It can be used for.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the embodiments.

Table 1 shows the layer structure and the thickness of each layer of the synthetic resin sheet 1 used in Examples and Comparative Examples. In Table 2, the compounding quantity of the compounding raw material in each layer of the synthetic resin sheet 1 is shown. Table 3 shows the deflection resistance (load at the time of 5 mm deflection on the MD surface and the TD surface), surface properties (Ra, concave portion ratio), and surface color (color tone, YI value) of the synthetic resin sheet 1. Table 4 shows the results of evaluating the flameproofness, antistatic property, returnability and crack resistance of the panel.
The melting point of the brominated flame retardant is based on the DSC curve obtained by heating and melting 2 to 4 mg of the measurement sample from 40 ° C. to 370 ° C. at a heating rate of 10 ° C./min based on JIS K7122: 1987. It is the value which calculated | required the peak temperature of a high melting peak as melting | fusing point of a brominated flame retardant.

  In Table 3, the load at the time of deflection of 5 mm, the arithmetic average roughness Ra of the embossed surface, the recess ratio, and the YI value were measured by the above methods (N = 5).

In Table 4, the flame resistance, antistatic property, returnability and crack resistance were evaluated by the following methods.
(Fireproof)
Evaluation Criteria Those having the performance satisfying the standard of the 45 ° Meckel burner method of the flameproof test standard established by the Japan Flameproof Association were evaluated as “◯” and the others were evaluated as “X”.
Evaluation method Sample size 29 × 19 cm, heating time 2 minutes,
◯: Residual flame time of 10 seconds or less, residual dust time of 30 seconds or less, carbonization area of 70 cm ² or less, and no smoldering observed after heating.

(Antistatic property)
The case where the humidity was adjusted for 24 hours in an environment of 25 ° C. and 50% RH and the surface resistivity measured in accordance with JIS K6271: 2001 was 1 × 10 ¹³ Ω or less was indicated as “◯”.

(Returnable)
When the output paper was peeled off, those having a peel strength of 7 N / m or more and 100 N / m or less were set as “◯”, and the others were set as “X”. The peel strength is obtained by peeling a bonded portion of a test piece having a width of 25 mm and a length of 250 mm at a rate of 200 mm / min by a method based on a 180 degree peel test of JIS K6854-2: 1999. It was.

(Crack resistance)
When a corner portion of a panel having a sample size of 970 × 1000 was dropped from a height of 700 mm, a panel without a large crack was designated as “◯”, and the others were designated as “x”.

1 synthetic resin sheet 2 core layer 3 surface layer 4 intermediate layer

Claims (10)

A panel made of a synthetic resin sheet having a thickness of 1 to 5 mm and having flame resistance,
The synthetic resin sheet is a multilayer sheet having a core layer and a surface layer laminated and bonded to at least one surface of the core layer via an intermediate layer,
The ratio of the thickness of the core layer to the total thickness of the synthetic resin sheet is 50% or more,
The base resin of the core layer and the intermediate layer is a mixed resin of polystyrene resin and polypropylene resin,
The base layer resin of the surface layer is a polypropylene resin,
The weight ratio of polystyrene resin to polypropylene resin in the core layer is 20 to 70% by weight of polystyrene resin and 30 to 80% by weight of polypropylene resin (however, the total of polystyrene resin and polypropylene resin is 100% by weight). %)), And
Each layer of the synthetic resin sheet is a panel containing a brominated flame retardant as a flame retardant.   The weight ratio of polystyrene resin to polypropylene resin in the intermediate layer is 10 to 70% by weight of polystyrene resin and 30 to 90% by weight of polypropylene resin (however, the total of polystyrene resin and polypropylene resin is 100). The panel of claim 1, wherein the weight percentage is.   The weight ratio of polystyrene resin to polypropylene resin in the core layer is 50 to 70% by weight of polystyrene resin and 30 to 50% by weight of polypropylene resin (however, the total of polystyrene resin and polypropylene resin is 100). The panel according to claim 1, wherein the panel is a percentage by weight.   The panel in any one of Claims 1-3 in which the weight ratio of the polystyrene-type resin in the said intermediate | middle layer is lower than the weight ratio of the polystyrene-type resin in the said core layer.   The amount of the flame retardant in the core layer and the intermediate layer is 8 to 25 parts by weight with respect to 100 parts by weight of the respective base resin, and the amount of the flame retardant in the surface layer is 100 parts by weight of the base resin. The panel in any one of Claims 1-4 which is 5-15 weight part with respect to this.   The panel according to claim 5, wherein a blending ratio of the flame retardant in the core layer and the intermediate layer is higher than a blending ratio of the flame retardant in the surface layer.   The brominated flame retardant of the core layer contains a brominated flame retardant having a melting point of 200 ° C or lower, and the brominated flame retardant of the surface layer contains a brominated flame retardant having a melting point of 250 ° C or higher. The panel according to any one of 6.   The panel according to claim 1, wherein each layer of the synthetic resin sheet further contains antimony trioxide.   The panel in any one of Claims 1-8 whose load at the time of 5 mm bending based on JISK7171: 2008 in the extrusion direction of the said synthetic resin sheet is 95 N / 25mm or more. The synthetic resin sheet according to any one of claims 1 to 9, wherein the synthetic resin sheet is a multilayer sheet having a five-layer structure including the core layer and the surface layer laminated and bonded to both surfaces of the core layer via the intermediate layer. Panel described in.