JP2020059214A - Decorative sheet and decorative laminate - Google Patents

Abstract

To provide a decorative sheet excellent in moist heat resistance and processability.SOLUTION: A decorative sheet 10 has a pattern layer 12 using as a binder resin a urethane resin including polycarbonate diol, polyalkylene glycol and polyisocyanate as constituent elements, an adhesion layer 13, a transparent resin layer 14 and a surface protective layer 15 sequentially laminated in this order on a base material layer 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a decorative sheet and a decorative plate that have excellent durability under high temperature and high humidity.

A decorative sheet in which a decorative sheet is attached to at least one surface of a base material is required to have resistance to high temperature and high humidity (moisture and heat resistance) in applications such as building exterior materials and bathroom wall materials. The pattern layer that gives a design to a decorative sheet is generally formed by printing an ink containing a binder resin and a pigment on a base material layer such as polyolefin or polyester.
Conventionally, as the binder resin for the pattern layer, nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, etc. have been used (for example, Patent Document 1).
As a binder resin for the pattern layer, an acrylic resin that does not have a hydrolyzable group can be used in applications where resistance to moisture and heat is required, but when processing a decorative sheet, there is a problem that cracks or whitening easily occur in the pattern layer. there were.

Japanese Patent No. 4737722

  An object of the present invention is to provide a decorative sheet and a decorative plate which are excellent in wet heat resistance and processability in view of the above problems.

In order to achieve the above object, in the decorative sheet according to one embodiment of the present invention, a pattern layer in which a urethane resin containing polycarbonate diol, polyalkylene glycol and polyisocyanate as constituent elements is used as a binder resin is laminated on a base material layer. ing.
A decorative board according to an aspect of the present invention includes the above-described decorative sheet and a base material having the decorative sheet attached to at least one surface.

  According to the present invention, it is possible to provide a decorative sheet and a decorative plate that are excellent in wet heat resistance and processability.

It is a typical sectional view showing a decorative plate concerning the present invention.

Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimension, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following description. Further, it is needless to say that the drawings include portions in which dimensional relationships and ratios are different from each other.
In addition, the embodiments described below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is that the material, shape, structure, and arrangement of components are Etc. are not specified below. Various changes can be added to the technical idea of the present invention within the technical scope defined by the claims described in the claims.

[Structure of decorative sheet and decorative plate]
As shown in FIG. 1, a decorative sheet 10 according to an embodiment of the present invention (hereinafter referred to as the present embodiment) includes a base material layer 11, a pattern layer 12, an adhesive layer 13, a transparent resin layer 14, and a surface protection layer. The layer 15 and the layer 15 are stacked in this order.
Further, in the decorative board 20 of the present embodiment, the adhesive layer 22 and the decorative sheet 10 are laminated in this order on one surface of the base material 21.

[Base material layer]
Polyolefin or polyester is preferably used for the base material layer 11, and can be arbitrarily selected from existing materials such as polyethylene, polypropylene, polybutylene, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.
The base material layer 11 may be subjected to surface treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet ray treatment, and dichromic acid treatment in order to supplement the adhesion with the pattern layer 12.

[Pattern layer]
The pattern layer 12 is formed by printing a pattern ink using a urethane resin containing polycarbonate diol, polyalkylene glycol, neopentyl glycol and polyisocyanate as constituent elements as a binder resin on the base layer 11.
Polycarbonate diol is a polyol that is generally used as a urethane raw material, and it is possible to obtain a polyurethane having excellent hydrolysis resistance, but in building material applications, flexibility may be insufficient, especially at low temperatures. If this polycarbonate diol is applied to the pattern layer 12, it may not be able to follow the deformation of the sheet during processing of the building material, and cracks or whitening may occur.

Polyalkylene glycol has a polyether structure and is inferior in hydrolysis resistance to polycarbonate, but is excellent in flexibility. In the present embodiment, by using polyalkylene glycol together with polycarbonate diol, both adhesion to the base material layer 11 and processability are achieved.
Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like, and polytetramethylene glycol having high hydrophobicity is preferable from the viewpoint of durability against high temperature and high humidity (moisture heat resistance).
Neopentyl glycol is included in the urethane resin of the pattern layer 12 to improve the wet heat resistance.

The urethane resin can be synthesized by an addition polymerization reaction of polyol and polyisocyanate, which is a known technique. The end of the urethane resin is usually an isocyanato group sealed with a hydroxyl group or an amine, and when the end is a hydroxyl group, the pattern layer can be cured by blending a curing agent such as isocyanate with the pattern ink. .
The polycarbonate diol and polyalkylene glycol can be appropriately selected and used from various commercially available materials from the viewpoint of molecular weight and the like. As the polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate and hydrogenated products thereof can be used.
The curing agent used for curing the urethane resin is not particularly limited, and commercially available curing agents including hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate and its hydrogenated product, diphenylmethane diisocyanate and its hydrogenated product, etc. The agent can be appropriately selected and used.

The pattern layer 12 can use various additives such as pigments, colorants such as dyes, extender pigments, solvents, and light stabilizers as components other than the binder resin. Examples of the pigment include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, pearl pigments such as mica, and the like. The method for providing the pattern layer 12 is not particularly limited, and a usual printing method such as gravure printing, offset printing, screen printing, flexo printing, ink jet printing can be used.
The method of joining the transparent resin layer 14 to the base material layer 11 on which the pattern layer 12 is formed by printing is not particularly limited, and heat lamination, extrusion lamination, dry lamination, sand sandwiching the adhesive layer 13 as necessary. Various laminating techniques such as laminating can be used.

[Adhesive layer]
The adhesive layer 13 and the adhesive layer 22 are not particularly limited, and a material which is appropriately selected from urethane-based, acrylic-based, acryl-silicone-based, fluorine-based, epoxy-based, or other resin materials and made into an ink is gravure-coated or micro-coated. It is formed by using a normal coating method such as gravure coating, comma coating, knife coating, and die coating.

[Transparent resin layer]
The transparent resin layer 14 is not particularly limited, but polyolefin is preferably used. As the polyolefin, for example, polypropylene, polyethylene, polybutene, and various α-olefin copolymers (copolymers of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc.) are used. The transparent resin layer 14 may be mixed with various additives such as an ultraviolet absorber, a heat stabilizer, a light stabilizer, an antiblocking agent, a catalyst scavenger, a colorant, a light scattering agent and a luster modifier, if necessary. Good. The method for producing the transparent resin layer 14 is not particularly limited, and a usual method such as calender film formation or extrusion film formation can be used.
Further, the transparent resin layer 14 may be provided with surface irregularities in order to impart a design property. As a method of providing the unevenness, for example, there is a method of subjecting the transparent resin layer 14 to extrusion molding and then hot embossing, and a method of simultaneously performing extrusion molding and embossing using a cooling roll provided with unevenness at the time of extrusion formation.

[Surface protection layer]
The surface protective layer 15 is provided to impart functions such as weather resistance, scratch resistance, stain resistance, and designability to the decorative sheet 10, and the material is not particularly limited, but urethane-based, acrylic-based The resin material is appropriately selected from resin materials such as acrylic resin, acrylic silicon, fluorine, and epoxy. The surface protective layer 15 may contain various additives such as an ultraviolet absorber, a heat stabilizer, a light stabilizer, an antiblocking agent, a catalyst scavenger, a colorant, a light scattering agent and a luster modifier, if necessary. May be.

The method for forming the surface protective layer 15 is not particularly limited, and a solution obtained by applying the above-mentioned material to a liquid is applied by a usual method such as gravure coating, microgravure coating, comma coating, knife coating, or die coating, and then heat treatment is performed. It is formed by curing by a method suitable for the material such as curing or ultraviolet curing.
Next, the thickness of the layers forming the decorative sheet 10 will be described.
The substrate layer 11 is 20 μm to 150 μm in consideration of printing workability and cost, the pattern layer is 0.5 to 10 μm, the adhesive layer 13 is 1 μm to 20 μm, the transparent resin layer 14 is 20 μm to 200 μm, and the surface protective layer 15 is It is preferable that the thickness is 3 μm to 20 μm, and the total thickness of the decorative sheet 10 is preferably in the range of 45 μm to 250 μm.

[Effect of decorative sheet and decorative plate]
Next, the effect of the decorative sheet 10 of this embodiment will be described.
The pattern layer 12 of the decorative sheet 10 is based on a pattern ink that uses a polycarbonate diol and a urethane resin containing a polyalkylene glycol and a polyisocyanate as components for achieving both adhesion to the base material layer 11 and processability as a binder resin. It is laminated on the material layer 11. Therefore, when the decorative sheet 10 is processed, the pattern layer 12 is unlikely to be cracked or whitened, and the processability of the decorative sheet 10 can be improved.
In addition, the wet heat resistance of the decorative sheet 10 can be improved by further containing neopentyl glycol as a constituent element of the urethane resin of the pattern layer 12.
Moreover, the moisture heat resistance of the decorative sheet 10 can be improved by using polytetramethylene glycol as the polyalkylene glycol which is a constituent element of the urethane resin of the pattern layer 12.

Moreover, since the base material layer 11 is formed of polyolefin or polyester, dioxin is not generated even when the decorative sheet 10 is burned when it is discarded, and the environmental load can be suppressed.
Further, since the transparent resin layer 14 is laminated on the design layer 12, the abrasion resistance of the design layer 12 can be ensured and the design of the design layer 12 can be emphasized.
Further, by laminating the surface protective layer 15 on the transparent resin layer 14, the decorative sheet 10 can be provided with functions of weather resistance, scratch resistance, stain resistance, and designability.
On the other hand, the decorative plate 20 in which the decorative sheet 10 is attached to one surface of the base material 21 also has improved processability and resistance to moist heat, and does not generate dioxin even when burned at the time of disposal, so that the environmental load can be suppressed. The wear resistance of the design layer 12 can be ensured, the pattern of the design layer 12 can be emphasized, and the design layer 12 can be prevented from peeling off due to external force such as impact force.

Next, the present invention will be described more specifically by showing decorative sheets of Examples and Comparative Examples.
<Example 1>
A urethane resin containing polycarbonate diol, polyalkylene glycol as a polyol component, polytetramethylene glycol (PTMG) as a polyalkylene glycol, neopentyl glycol (NPG), and polyisocyanate as components was synthesized. Here, a hydroxyl group-terminated urethane resin having a number average molecular weight of 2 × 10 ⁴ was synthesized by a known addition polymerization method using isophorone diisocyanate as the polyisocyanate. Then, a copper phthalocyanine-based pigment was dispersed in this urethane resin at a mass ratio of (pigment / urethane resin) = 20/80 to prepare a pattern ink. An isocyanate curing agent was added to this ink, and a hiding polyethylene (PE) original fabric (thickness 70 μm) was gravure-printed as the base material layer 11 to form a pattern layer 12 (thickness 3 μm). Then, a transparent homopolypropylene resin is extruded and laminated on the pattern layer 12 through an adhesive for dry lamination (thickness 2 μm) to laminate a transparent resin layer (thickness 80 μm), and the decorative sheet 10 of Example 1 is obtained. Formed.

<Example 2>
The decorative sheet of Example 2 was prepared in the same manner as in Example 1, except that the base material layer 11 in Example 1 was replaced with a polybutylene terephthalate (PBT) original fabric (thickness 70 μm). Formed 10.
<Example 3>
A decorative sheet 10 of Example 3 was formed in the same manner as in Example 1 except that neopentyl glycol (NPG) was not used as a polyol component in the urethane resin synthesis of Example 1.
<Example 4>
A decorative sheet 10 of Example 4 was formed in the same manner as in Example 3 except that polypropylene glycol (PPG) was used as the polyalkylene glycol in the synthesis of the urethane resin of Example 3.

<Comparative Example 1>
In the synthesis of the urethane resin of Example 1, a decorative sheet 10 of Comparative Example 1 was formed in the same manner as in Example 1 except that PTMG was not used as the polyol component.
<Comparative example 2>
A decorative sheet 10 of Comparative Example 2 was obtained in the same manner as in Example 1 except that polycarbonate diol was not used as the polyol component in the urethane resin synthesis of Example 1.

<Evaluation judgment>
With respect to the decorative sheets 10 obtained in Examples 1 to 4, Comparative Example 1 and Reference Example described above, the workability and the moist heat resistance were evaluated by the following methods. Table 1 shows the evaluation results.
(A) Workability A sample in which a decorative sheet was attached to an aluminum plate (thickness 0.4 mm) using an adhesive for building materials (No-Tape Kogyo, No 5211) was bent at 90 ° at an environmental temperature of 5 ° C. The appearance was visually observed. The evaluation criteria are "○: no cracks are found in the picture layer" and "x: cracks are found in the picture layer".
(B) Moisture and heat resistance Wet heat treatment of a decorative sheet was carried out in a HAST chamber (105 ° C., 100% RH, 192 hours), and then the T-shaped peel strength between the transparent resin layer and the substrate was measured (sample width: 25 mm, Pulling speed: 5mm / sec). The evaluation criteria are "A: peeling interface is not formed and the base material is broken", "○: peeling surface is generated while the base material is deformed", "△: peeling surface is generated without base material deformation", "x: sample It cannot be measured because peeling occurs during handling. "

As can be seen from Table 1, in the decorative sheets 10 shown in Examples 1 to 2, the binder resin of the pattern layer 12 contains polycarbonate diol, polyalkylene glycol, neopentyl glycol (NPG) and polyisocyanate as constituent elements. By using the urethane resin containing it, it becomes excellent in workability and wet heat resistance.
Further, the decorative sheet 10 using a urethane resin containing polycarbonate diol, polyalkylene glycol, neopentyl glycol (NPG) and polyisocyanate as constituent elements is attached to one surface of the base material 21 as the binder resin of the pattern layer 12. The combined decorative plate 20 also has excellent processability and resistance to moist heat.

10 Decorative Sheet 11 Base Layer 12 Picture Layer 13 Adhesive Layer 14 Transparent Resin Layer 15 Surface Protective Layer 20 Decorative Board 21 Base Material 22 Adhesive Layer

Claims (8)

  A decorative sheet characterized in that a pattern layer using a urethane resin containing a polycarbonate diol, a polyalkylene glycol and a polyisocyanate as constituent elements as a binder resin is laminated on a base material layer.   The decorative sheet according to claim 1, further comprising neopentyl glycol as the constituent element of the urethane resin.   The decorative sheet according to claim 1, wherein the polyalkylene glycol is polytetramethylene glycol.   The decorative sheet according to any one of claims 1 to 3, wherein the resin component of the base material layer is polyolefin.   4. The decorative sheet according to claim 1, wherein the resin component of the base layer is polyester.   The decorative sheet according to any one of claims 1 to 5, wherein a transparent resin layer is laminated on the pattern layer.   The decorative sheet according to claim 6, wherein a surface protective layer is laminated on the transparent resin layer.   A decorative sheet comprising: the decorative sheet according to any one of claims 1 to 7; and a base material having the decorative sheet bonded to at least one surface thereof.

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