JPH11138719A - Decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a decorative sheet having weatherability in spite of employing of polyolefin resin, and also good molding applicability. SOLUTION: As polyolefin resin, there is used ethylene.propylene.butene copolymeric resin, and a decoration treatment is applied to a base material sheet consisting of the resin. An organic UV ray absorbing agent including a hydroxyl group is added in the base material sheet; then forming an overcoat layer consisting of resin having an isocyanate group in its molecules on the surface side of the base material sheet 1, as a result, the UV ray absorbing agent does not bleed out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an interior material for a building,
The present invention relates to a decorative sheet used for a surface decorative material of a fitting, a vehicle interior material, and the like.

[0002]

2. Description of the Related Art Conventionally, as a decorative sheet used for this kind of application, polyvinyl chloride is used as a base sheet,
To this, decorative sheets decorated with printing, embossing or the like (for example, JP-B-28-5036, JP-B-58-143)
In recent years, as an alternative, a decorative sheet using a polyolefin resin sheet such as polyethylene or polypropylene has appeared (see, for example, Japanese Patent Application Laid-Open No. 54-62255). ).

[0003]

However, decorative sheets of polyolefin resin have the following problems when they are mass-produced industrially and used as interior materials for buildings. Lack of transparency. Poor weather resistance. Insufficient adhesion to ink, adhesive, etc. during printing and lamination. It has low impact resistance and cracks during V-cut processing. In particular, crystallization progresses due to the heat history during embossing from heating softening to embossing plate pressing to cooling, the sheet becomes brittle, and this tendency is strengthened. Non-uniform elongation occurs during heat molding, causing so-called "necking" that causes unevenness in thickness, wrinkles, distortion of the decorative layer, and the like. Due to high crystallinity, embossing conditions are very narrow.

[0004] Among these problems, the adhesive force of the above could be solved by the corona discharge treatment or the application of the easy-adhesion primer, but the weather resistance of the polyolefin itself is limited due to insufficient weather resistance. Even when the ultraviolet absorber is added, the organic compound-based ultraviolet absorber which is usually used has poor compatibility with the polyolefin resin, and is bleed out with time and is lost, so that a sufficient effect cannot be obtained. As for the suitability for molding process, it is possible to improve the suitability of molding by lowering the crystallinity of the resin by mixing rubber as a soft segment in the resin. Sex has been reduced. Therefore, all of (1) could not be improved.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to use a polyolefin resin and have excellent weather resistance and excellent molding workability. It is to provide a decorative sheet.

[0006]

In order to solve the above-mentioned problems, the decorative sheet of the present invention uses an ethylene / propylene / butene copolymer resin as a polyolefin resin and decorates a base sheet made of this resin. It is characterized by processing.

An organic UV absorber having a hydroxyl group in the molecule is added to the outermost substrate sheet, and an overcoat made of a resin having an isocyanate group in the molecule is provided on the surface side of the substrate sheet. It is preferred to form a layer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The ethylene-propylene-butene copolymer resin serving as a base sheet has 1-butene as its butene.
Any of the three structural isomers of butene, 2-butene, and isobutylene can be used. The copolymer is preferably a random copolymer which contains a part of an amorphous portion and is a thermoplastic elastomer.

Preferred specific examples of the ethylene / propylene / butene copolymer include the following.

[0010] Japanese Patent Application Laid-Open No. 9-1111055. This is a random copolymer of a terpolymer of ethylene, propylene and butene. The weight ratio of the monomer components is 90% by weight or more of propylene. Melt flow rate is 1 to 50 g / 10 at 230 ° C. and 2.16 kg.
Minutes are preferred. Then, based on 100 parts by weight of such a ternary random copolymer, 0.01 to 50 parts by weight of a transparent nucleating agent containing a phosphoric acid aryl ester compound as a main component, and 0.1 to 0.2 parts by weight of a fatty acid amide having 12 to 22 carbon atoms. 003 ~
0.3 parts by weight are melt-kneaded.

The one described in JP-A-5-77371. This is a terpolymer of ethylene, propylene, and 1-butene. The content of the propylene component is 50 to 100% by weight of the amorphous polymer 20 to 100% by weight, and the crystalline polypropylene is 80 to 0% by weight. It is added.

The one described in JP-A-7-316358. This is a terpolymer of ethylene, propylene and 1-butene, wherein the content of propylene and / or 1-butene is 50% by weight or more and the low crystalline polymer is 20 to 100% by weight.
And an oil gelling agent such as N-acylamino acid amine salt or N-acylamino acid ester in an amount of 0.5% by weight based on 100 parts by weight of a composition obtained by mixing 80 to 0% by weight of a crystalline polyolefin such as isotactic polypropylene. It is added.

The ethylene / propylene / butene copolymer resin may be used alone, or may be used in combination with other polyolefin resins described above or, if necessary. The base sheet has a thickness of about 50 to 500 μm, and any of a stretched sheet and an unstretched sheet can be used, but the unstretched sheet has better formability such as V-cut processing. Various additives such as a filler, a foaming agent, a flame retardant, a lubricant, an antioxidant, an ultraviolet absorber, and a light stabilizer are added to the base sheet as needed. Among them, the ultraviolet absorber and the light stabilizer will be described later in detail.

The base sheet is subjected to a desired decoration treatment. Examples of the decoration treatment include coloring by kneading a coloring agent such as a pigment or a dye, formation of a decoration layer including a pattern of an ink picture layer and a metal layer, and formation of an uneven pattern. The decorative layer or the concavo-convex pattern may be formed on the front surface, the back surface, or both the front and back surfaces of the base sheet when the base sheet is transparent, but needs to be formed on the front side when the base sheet is opaque. When used as a decorative sheet, such as a backing sheet, to be adhered to the back surface of the adherend as it is, there is no need for decorative treatment.

In the case of coloring by kneading a pigment or dye, the coloring may be transparent or opaque (concealing) depending on the application. As pigments, titanium white, zinc white, ultramarine blue, cobalt blue, red iron oxide, vermilion, graphite, titanium yellow, inorganic pigments such as carbon black, quinacridone, permanent red 4R, isoindolinone, Hansa yellow A, phthalocyanine blue, Organic pigments or dyes such as Indaslen Blue RS and aniline black, metal pigments made of foil powder such as aluminum and brass, pearlescent (pearl) pigments made of titanium dioxide-coated mica, foil powder of basic lead carbonate, etc. Used. In addition, extenders (fillers) such as calcium carbonate, silica (silicon dioxide), alumina (aluminum oxide), and barium sulfate are added as necessary.

In order to form a decorative layer with a pattern of ink, a normal printing method such as gravure printing, offset printing, letterpress printing, silk screen printing or the like can be used, but drawing may be used. The picture is formed by forming an ink composed of a resin binder and a pigment or a dye into an arbitrary pattern. In addition, an ink layer on a peelable support sheet, and a transfer sheet having an adhesive layer formed thereon if necessary are prepared in advance, and the ink layer formed on the transfer sheet is pressurized or pressed. It is also possible to use a so-called transfer printing method in which the image is transferred to the surface on which the decorative layer (ink picture layer) is formed by heating. Examples of patterns include wood grain, stone grain, cloth grain, leather crest, characters, figures, and solid solids.

Examples of binders for ink (or paint) include chlorinated polyolefin resins such as chlorinated polyethylene and chlorinated polypropylene, polyester resins, urethane resins, acrylic resins, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, and cellulose. These resins are used alone or in combination of two or more. To this, those obtained by adding known pigments as listed above are used. When printing directly on the substrate sheet, chlorinated polyolefin, urethane resin, etc. are preferable as the binder in terms of adhesiveness, but if an easy-adhesion primer is appropriately selected and a layer is formed, other binders may be used. High adhesiveness is obtained.

The pattern of the metal layer is formed by vacuum-depositing a metal such as aluminum, chromium, gold, silver, and copper. Such a metal layer may be formed on the entire surface, or may be formed in a pattern (pattern). To form the pattern, a removal layer is formed by a water-soluble ink on a metal layer unnecessary portion. A known method such as vapor deposition of a metal over the entire surface from above and then washing with water to remove the metal layer immediately above the removal layer together with the above-mentioned removal layer. Further, a so-called transfer printing method in which a metal layer formed in advance on a transfer sheet is transferred to a surface on which a decorative layer (metal layer) is to be formed can also be used.

Printing a pattern directly on the base sheet itself,
It is possible to apply an adhesive, but if it is necessary to further strengthen the adhesive force between the ink or the adhesive and the base sheet, forming an easy-adhesion layer on the front or back surface of the base sheet And an easy adhesion treatment such as a corona discharge treatment, a plasma treatment, and an ozone treatment.

Polyester resin, urethane resin, chlorinated polypropylene, chlorinated polyethylene and the like are used for forming the easy-adhesion layer (also referred to as primer layer or anchor layer), and urethane resin is particularly preferable. More preferably, the surface of the substrate sheet to be subjected to the easy adhesion treatment is first subjected to corona discharge treatment or plasma treatment to form a hydroxyl group, a functional group containing an active hydrogen such as a carboxyl group on the substrate sheet surface, To form an urethane resin adhesive layer,
It is preferable that the functional group on the surface of the base material sheet and the isocyanate group in the urethane resin be urethane-bonded.

As the urethane resin, there are a two-component curing type urethane resin and a one-component curing type urethane resin. The two-component curable urethane resin has a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent),
The hydroxyl group in the polyol molecule and the isocyanate group in the isocyanate are urethane-bonded, and each molecule is cross-linked to a three-dimensional network polymer. As this polyol, those having two or more hydroxyl groups in the molecule,
For example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol,
Polyether polyol, polycarbonate polyol and the like are used. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in a molecule is used. For example, aromatic isocyanates such as 2-4 tolylene diisocyanate, xylene diisocyanate, 4-4 diphenylmethane diisocyanate,
Or hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate,
An aliphatic or alicyclic isocyanate such as hydrogenated diphenylmethane diisocyanate is used. Alternatively, adducts or multimers of the above various isocyanates can also be used. For example, an adduct of tolylene diisocyanate, a trimer of tolylene diisocyanate (trim)
er).

As a method of forming the concavo-convex pattern, there are hairline processing, sand blasting, embossing and the like, and a concavo-convex pattern having a concavo-convex shape is formed on the base sheet by these methods.

In the embossing, the embossing plate is pressed against the surface of the heated and softened base sheet by using a hot press type sheet-fed or rotary embossing machine to shape the unevenness of the surface of the embossing plate. This is a method of forming a concavo-convex pattern. Examples of the concavo-convex pattern formed by the embossing include those expressing wood grain conduit grooves, wood grain wood texture, stone surface unevenness, fabric surface texture, satin finish, grain, hairline, and the like, or a combination thereof. Further, if necessary, a known wiping method may be applied to the concave portions of the concave and convex pattern (for example, see Japanese Patent Publication No. 58-14312).
Can be filled with a coloring ink. As the coloring ink, the same one as described above can be used. However, it is preferable to use a two-component curable urethane resin as a binder in terms of abrasion resistance. Wiping may be performed by any of conventionally used wiping methods such as a doctor blade method and a roll coating method. According to these methods, the colored ink is applied to the entire surface of the concave and convex pattern, and then the ink of the convex portion is scraped off to leave the colored ink in the concave portion.

The form of the decorative sheet may be a single-layer structure composed of only a base sheet as shown in FIG. 1, a two-layer structure composed of a base sheet and a top sheet as shown in FIG. There is a stack of more than one layer (not shown).

The decorative sheet S shown in FIG. 1A is obtained by adding a coloring agent 2 such as a pigment to a base sheet 1 and coloring the base sheet 1. The decorative sheet S in FIG. An easy-adhesion layer 3 is provided, and a decorative layer 4 (solid or partial pattern on the entire surface) formed by printing or a metal thin film is formed thereon. Further, the decorative sheet S of FIG. 1C is one in which an uneven pattern composed of the concave portions 5 is formed on the surface of the base sheet 1,
The decorative sheet S shown in FIG. 1D has a concave portion on the surface filled with a coloring agent 6 by wiping, and a decorative layer 4 provided on the surface.

The decorative sheet S shown in FIG. 2A is obtained by forming a decorative layer 4 on a transparent substrate sheet 1 on the back side and laminating a transparent substrate sheet 7 on the front side. FIG. 2
In the decorative sheet shown in (b), the decorative layer 4 is formed on the surface of the opaque base material sheet 1 on the back side colored by adding a coloring agent 2 such as a pigment, and the transparent base material sheet on the front side is formed thereon. 7 are laminated. In order to laminate the two layers, the front side base sheet 7 is laminated on the back side base sheet 1 by dry lamination with an adhesive, heat fusion by hot pressing, or the front side base sheet. 7 by melt extrusion and lamination (extrusion coating).

In the decorative sheet S shown in FIG. 2C, a decorative layer 4 is formed on a back-side base sheet 1 which is colored and concealed by adding a coloring agent 2 such as a pigment, and a front-side transparent substrate is formed thereon. After laminating the material sheets 7, an embossed pattern formed by the concave portions 5 is formed by embossing. Further, the decorative sheet S shown in FIG. 2D is obtained by filling the concave portions on the surface of the decorative sheet of FIG. 2C with the coloring agent 6 by wiping.

In order to improve the weather (light) resistance, an organic ultraviolet absorbent excellent in transparency is added to the outermost substrate sheet. In the present invention, an organic compound having a hydroxyl group (OH group) in the molecule is used as the ultraviolet absorber. The reason for selecting a compound having a hydroxyl group in the molecule is to stop bleeding in the overcoat layer described later. As such an ultraviolet absorber, for example, 2-
(2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2′-hydroxy-3′-tert-butyl-5′-
Methylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3'tert-amyl-5'-
Isobutylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5 '
-Methylphenyl) -5-chlorobenzotriazole,
A 2'-hydroxyphenyl-5-chlorobenzotriazole-based ultraviolet absorber such as 2- (2'hydroxy-3'-isobutyl-5'-propylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy- 3 ',
Benzotriazole UV absorption such as 2'-hydroxyphenylbenzotriazole UV absorbers such as 5'-di-tert-butylphenyl) benzotriazole and 2- (2'-hydroxy-5'-methylphenyl) benzotriazole Agent, 2,2'-dihydroxy-4-
Methoxybenzophenone, 2-2'-dihydroxy-
4,4′-dimethoxybenzophenone, 2,2 ′, 4
2,2′- such as 4′-tetrahydroxybenzophenone
Dihydroxybenzophenone ultraviolet absorbers, benzophenone ultraviolet absorbers such as 2-hydroxybenzophenone ultraviolet absorbers such as 2-hydroxy-4-methoxybenzophenone and 2,4-dihydroxybenzophenone, phenyl salicylate, 4-t- Butyl-phenyl-
A salicylate-based ultraviolet absorber such as salicylate is used. In addition, a reactive ultraviolet absorber in which an acryloyl group or a methacryloyl group is introduced into a benzotriazole skeleton is also used. In addition, the addition amount of these ultraviolet absorbers is usually about 0.1 to 5% by weight.

The deterioration of each layer due to ultraviolet rays is further prevented,
In order to improve weather resistance, it is preferable to add a radical scavenger as another light stabilizer. Examples of the radical scavenger include bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate and bis- (N-methyl-2,2,6,6-tetramethyl-4-piperidinyl)
Hindered amine radical scavengers and piperidyl radical scavengers such as sebacate and other compounds disclosed in, for example, Japanese Patent Publication No. 4-82625 are used. In addition, when a light stabilizer comprising a hindered amine radical scavenger is added to a base sheet made of an ethylene-propylene-butene copolymer, an ink layer adjacent to the base sheet, a layer such as an adhesive layer may be used. Using a resin containing no chlorine atom in the molecule, such as a urethane resin, a polyester resin, or a polyamide resin, is also favorable in terms of improving weather resistance. If resins containing chlorine atoms in molecules such as vinyl chloride / vinyl acetate copolymers and chlorinated polyolefins are used, hydrogen chloride is generated from these resins by the action of ultraviolet light or heat, and this produces hindered amines. Since it reacts with the system radical scavenger to deactivate or inhibit its action, the weather resistance is not sufficiently improved.

When an ultraviolet absorber having a hydroxyl group in a molecule is added to the outermost substrate sheet, an overcoat layer made of a resin having an isocyanate group in the molecule is formed on the surface of the substrate sheet. . As the resin having an isocyanate group in the molecule, a two-component curable urethane resin or a one-component curable urethane resin is used. 2
As the liquid-curable urethane resin, a mixture of the same polyol and isocyanate as described above as the resin system of the easily adhesive layer is used.

In a preferred embodiment when a two-part curable urethane resin is used, the number (mol number) of isocyanate groups (—NCO groups) in the isocyanate is converted to the number of hydroxyl groups (—OH groups) of the polyol to be reacted therewith. Reaction equivalent)
In some embodiments, even after the polyol and the isocyanate have reacted, a large number of unreacted isocyanate groups remain reliably. In this case, -NCO group / -OH
The ratio of groups is up to about 1.4.

The one-component moisture-curable urethane resin is a composition containing a prepolymer having an isocyanate group at a molecular terminal as an essential component. The prepolymer is usually a polyisocyanate prepolymer having one or more isocyanate groups at both molecular terminals, and is a solid thermoplastic resin at room temperature. Isocyanate groups react with each other in the air due to moisture to cause a chain extension reaction, resulting in a reactant having a urea bond in the molecular chain,
The urea bond further reacts with the isocyanate group at the molecular terminal to cause a biuret bond and branch to cause a crosslinking reaction.

The skeleton structure of the molecular chain of the prepolymer having an isocyanate group at the molecular terminal is arbitrary, and specific examples thereof include a polyurethane skeleton having a urethane bond, a polyester skeleton having an ester bond, and a polybutazine skeleton. One or more of these skeletal structures are appropriately employed. When a urethane bond is present in the molecular chain, the terminal isocyanate group also reacts with the urethane bond to generate an allophanate bond, which also causes a cross-linking reaction.

To these overcoat layers, if necessary, an ultraviolet absorber (chosen from those described above), an abrasive and matting agent such as alumina and silica, and an antibacterial agent such as silver zeolite are added. .

As described above, an organic absorber having an OH group in the molecule is used as an ultraviolet absorber added to the outermost substrate sheet, and a resin having an isocyanate group is used to form an overcoat layer. When formed, the ultraviolet absorber bleeds out (exudes) over time and enters the overcoat layer, and the OH groups of the ultraviolet absorber and the isocyanate groups in the overcoat are urethane-bonded and trapped in the overcoat layer. Therefore, bleeding out of the ultraviolet absorbent over time is prevented. It is particularly effective when the organic ultraviolet absorber is a polyolefin resin that easily bleeds out, and is also suitable for the ethylene-propylene-butene copolymer used as the base sheet in the present invention.

The decorative sheet of the present invention can be laminated on another adherend (backing material). The adherend is the final product, and a decorative sheet may be laminated to make up the surface, or if necessary, may be applied to the back of the decorative sheet to reinforce the mechanical strength of the decorative sheet or to provide concealment. In some cases, bodies are stacked. When laminating on the adherend, the adhesive layer may be omitted if the decorative sheet itself can be adhered to the adherend (at a thermal melting point or the like). If the decorative sheet itself does not adhere to the adherend, an appropriate adhesive is used.

FIGS. 3 and 4 are sectional views showing the decorative sheet laminated on the adherend together with the adherend. FIG. 3 shows the decorative sheet S shown in FIG. 4 is laminated on a flat plate with an adhesive layer 9 interposed therebetween, and the one shown in FIG. Are laminated on the surface by a simultaneous molding lamination method (described later).

Examples of the adherend include various materials such as flat plates (FIG. 3) of various materials, plate materials such as curved plates, three-dimensionally shaped articles (FIG. 4), sheets (or films), and the like.
Examples of materials used for board materials, three-dimensionally shaped articles, and sheets (films) include wood veneer, wood plywood, particle board, wood board such as medium density fiber board (MDF), wood board such as wood fiber board, Metals such as iron and aluminum, acrylic resin, polycarbonate resin, ethylene / vinyl acetate copolymer, ethylene vinyl acetate, polyester resin, polystyrene, polyolefin resin, ABS, phenol resin, polyvinyl chloride, cellulose resin, rubber and other resins There is. Materials used exclusively as plate materials or three-dimensionally shaped articles include ceramics such as glass and porcelain, cement such as ALC (foamed lightweight concrete), and non-cement ceramic materials such as calcium silicate and gypsum. Materials used exclusively as sheets (or films) include paper such as high-quality paper, thin paper, and Japanese paper, and nonwoven fabrics or woven fabrics made of fibers such as carbon, asbestos, potassium titanate, glass, and synthetic resins.

As a method of laminating a decorative sheet on these various adherends, for example, a method of laminating a plate-like substrate by pressing with a pressure roller via an adhesive layer, Japanese Patent Publication No. Sho 50
As described in JP-A-19132, JP-B-43-27488, etc., a decorative sheet is inserted between the male and female molds for injection molding, the molds are closed, and the molten resin is injected from the male gate. After filling and cooling, the decorative sheet is adhered and laminated on the surface simultaneously with the molding of the resin molded product, so-called simultaneous injection molding laminating method, JP-B-56-45768,
As described in Japanese Patent Publication No. 60-58014, etc.,
A so-called vacuum press lamination method in which a decorative sheet is opposed to or placed on the surface of a molded article with an adhesive layer therebetween, and the decorative sheet is laminated on the surface of the molded article by a pressure difference due to vacuum suction from the molded article side, JP-B-61-5895, JP-B-3
As described in JP-A-2666, etc., while supplying a decorative sheet through an adhesive layer in the long axis direction of a columnar substrate such as a cylinder and a polygonal column, a plurality of rollers having different directions are used to form a columnar substrate. A so-called lapping method in which a decorative sheet is sequentially adhered to a plurality of side surfaces constituting a body by pressure bonding, which is a so-called lapping method, disclosed in Japanese Utility Model Publication No. 15-31122, and Japanese Patent Laid-Open No. 48-47972.
As described in Japanese Patent Laid-Open Publication No. H10-15095, first, a decorative sheet is laminated on a plate-like base material via an adhesive layer, and then the decorative sheet and the plate-like base material are provided on the surface of the plate-like base material opposite to the decorative sheet. Cut into a V-shaped or U-shaped groove reaching the interface with the material, then apply an adhesive in the groove, and then bend the groove to form a box or columnar body. There are V-cut and U-cut processing methods.

In particular, as a method of attaching the decorative sheet of the present invention to a three-dimensional object having irregularities, of the above-mentioned methods, a lapping method, a V-cut method, an injection molding simultaneous lamination method, a vacuum molding simultaneous lamination method, and the like are preferable.

The decorative sheet of the present invention is used for various applications by laminating on various adherends and subjecting it to a predetermined molding process. For example, building interiors such as walls, ceilings, floors, doors, window frames,
Door frames, handrails and other surface fittings for furniture, furniture such as chests,
Surface makeup such as cabinets for OA equipment, vehicle interiors such as cars and trains, aircraft and ship interiors, and window glass makeup.

[0042]

Embodiments of the present invention will be described below in detail.

Example A sheet of a thermoplastic elastomer made of an ethylene-propylene / 1-butene copolymer colored with opaque brown color by adding a pigment consisting of titanium white, red iron oxide and carbon black was used as a back side base sheet. Use
A corona discharge treatment was applied to both sides of the base sheet, and then a pattern was printed on the front side. Specifically, vinyl chloride
The woodgrain pattern was printed by gravure printing using an ink using a mixture of a vinyl acetate copolymer and an acrylic resin at a 1: 1 weight ratio as a binder and a reddish handle as a pigment. Then, a urethane / acrylate adhesive layer having a thickness of 3 μm was formed on the pattern decoration layer by a gravure roll coating method.

On the other hand, a benzotriazole type ultraviolet absorber having a hydroxyl group in the molecule (10000 ppm of "Tinuvin PFL" manufactured by Ciba-Geigy and 5000 ppm of "Tinuvin 622LD" manufactured by Ciba Geigy) are added to a thermoplastic elastomer composed of an ethylene / propylene / 1-butene copolymer. , Hindered amine radical scavenger (Irganox 1
010 "(1500 ppm) and" Adsil 5C37F "manufactured by Montell JPO, which has been mixed in advance, is used as the resin of the front side base sheet, and the resin of the front side base sheet is extruded from the T-die in a molten state, and the above-mentioned back side is obtained. After applying ozone spraying treatment to the side of the base sheet facing the adhesive layer, laminating it on the adhesive layer of the back side base sheet, at the same time as embossing plate and cooling roll having reverse irregularities of wood grain conduit grooves on the front side And solidified by cooling, and embossed with a wood grain conduit groove on the outermost surface.

Subsequently, hexamethylene diisocyanate and acrylic polyol were mixed at a mixing ratio of 100: 10, and 5% by weight of spherical alumina having an average particle size of 3 μm was added as a matting and lubricating agent. Using a curable urethane resin, this was gravure coated on the surface side substrate sheet to a thickness of 3 μm, cured in a 40 ° C. atmosphere for 3 days, and crosslinked and cured. As a result, a decorative sheet having a configuration in which an overcoat layer was provided on the decorative sheet having the configuration shown in FIG. 2C was obtained.

Comparative Example 1 The procedure of Example 1 was repeated except that isotactic polypropylene was used in place of the ethylene-propylene / 1-butene copolymer as the front-side substrate sheet and the back-side substrate sheet. A decorative sheet was manufactured.

Comparative Example 2 A decorative sheet was obtained in the same manner as in Example except that the overcoat layer was not provided.

(Evaluation) The decorative sheets obtained in Examples and Comparative Examples 1 and 2 were evaluated from the respective viewpoints in the following manner. Table 1 shows the results. As can be seen from the results, the decorative sheets of the examples had good weather resistance, and were also excellent in V cut processing suitability and emboss processing suitability.

[0049]

[Table 1]

[Transparency] Immediately after embossing, the lower pattern was visually observed through the surface-side substrate sheet, and the presence or absence of cloudiness and uneven gloss of the surface-side substrate sheet was confirmed.

[Interlayer Adhesion] The front side base sheet and the back side base sheet of the decorative sheet cut to a width of 1 inch were formed at an opening angle of 180 ° between the two sheets and a pulling speed of 50 mm / min.
And the tension at the time of peeling was measured to determine the adhesive strength.
The temperature at the time of measurement was 20 ° C.

[Weather Resistance] UV rays and artificial rain were exposed from the outermost surface side of the decorative sheet using a carbon arc lamp type sunshine weatherometer. The test was performed under the conditions of a black panel temperature of 63 ° C. and a rainfall time of 18 minutes / 120 minutes for 1000 hours. After the test, the decorative sheet was visually inspected for discoloration, cracking, whitening and delamination of the sheet. The peel strength after exposure was measured by the above method.

[Appropriateness of embossing] The reproducibility of the shape of the unevenness of the wood channel groove was visually evaluated immediately after the embossing.

[Appropriateness for V-cut processing] The obtained decorative sheet was laminated on a 5-mm-thick Rawan plywood using a two-component curable urethane resin adhesive so that the overcoat layer side was on the outside, and the temperature was 40 ° C. After curing for 3 days in the atmosphere of the above, they were bonded. Then, a groove having a V-shaped cross section which does not reach the decorative sheet was cut on the back surface of the plywood, an adhesive was applied to the groove, and the groove was bent so as to close the groove, thereby forming an L-shaped plywood. Thereafter, the presence or absence of cracks, breaks, whitening, and the like of the decorative sheet on the surface of the plywood was visually checked. The temperature during processing is 20 ° C.

[0055]

As described above, the decorative sheet of the present invention uses the ethylene-propylene-butene copolymer resin for the base sheet, so that the decorative sheet can be used while using a polyolefin resin. It is provided with weather resistance and proper molding.

Further, an organic UV absorber having a hydroxyl group in a molecule is added to a substrate sheet, and an overcoat layer made of a resin having an isocyanate group in a molecule is formed on the surface side of the substrate sheet. As a result, the ultraviolet absorber is captured by the overcoat layer, and bleeding over time is prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a decorative sheet according to the present invention.

FIG. 2 is a sectional view showing another example of the decorative sheet according to the present invention.

FIG. 3 is a cross-sectional view showing a decorative sheet laminated on an adherend together with the adherend.

FIG. 4 is a sectional view showing a decorative sheet laminated on an adherend together with the adherend.

[Explanation of symbols]

 S Decorative sheet 1 Base sheet 2 Colorant 3 Easy adhesion layer 4 Decorative layer 5 Depression 6 Colorant 7 Base sheet 8 Adherend 9 Adhesive 10 Adherend

Claims (2)

[Claims] 1. A decorative sheet obtained by subjecting a base sheet made of an ethylene / propylene / butene copolymer resin to a decoration treatment. 2. An overcoat comprising a resin having an isocyanate group in the molecule on the surface side of the base sheet while adding an organic ultraviolet absorber having a hydroxyl group in the molecule to the outermost substrate sheet. The decorative sheet according to claim 1, wherein a layer is formed.