JP2009066967A - Decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet having such an excellent weatherability as to also satisfy sufficiently the weatherablity requirements for surface materials of exterior construction materials. <P>SOLUTION: The decorative sheet keeps a substrate sheet 6 overlaid with at least one protective layer 1 composed of a transparent or translucent resin copolymerized with a hindered amine type optical stabilizer, and the protective layer contains at least one UV absorber selected from triazine and benzotriazole type UV absorbers and inorganic UV absorbers comprising metal oxides. Alternatively, the protective layer contains a hindered amine type optical stabilizer without being copolymerized with the resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a decorative sheet used as a building material such as an interior / exterior member for construction, a fitting, a frame material, a flooring material, or a surface material for home appliances, and mainly wood boards, inorganic boards, metals. The present invention relates to a decorative sheet used when a decorative sheet is produced by bonding to a plate or the like.

  Conventionally, as a decorative sheet used as a construction material such as an interior / exterior member for construction, joinery, frame material, flooring, or a surface material for home appliances, a sheet mainly composed of vinyl chloride resin is widely used. ing. However, vinyl chloride resin is said to generate chlorine gas during incineration, which is said to cause acid rain and dioxins. Furthermore, a sheet made of vinyl chloride resin has a plasticizer added to it. There is also a problem of bleeding out, and from the viewpoint of environmental problems, development of a decorative sheet that does not use a vinyl chloride resin has been strongly demanded.

  For the above reasons, in recent years, many decorative sheets using materials (non-vinyl chloride materials) that do not use vinyl chloride resins such as olefin resins have been proposed as alternatives to decorative sheets using vinyl chloride resins (for example, (See Patent Documents 1 to 4).

However, a non-vinyl chloride decorative sheet using a general polyolefin sheet or a flexible polyolefin sheet is significantly inferior in surface scratch resistance and weather resistance as compared with a conventional decorative sheet using a vinyl chloride resin. In order to improve surface scratch resistance, it may be possible to use a material with high crystallization and high isotacticity, but it tends to deteriorate the weather resistance.

Then, in order to improve weather resistance, the proposal which added weathering agents, such as a ultraviolet absorber, in the sheet | seat made from olefin resin is also made | formed.

However, depending on the type of weathering agent, there are many cases where even if added to the polyolefin sheet, the original function as a weathering agent cannot be sufficiently performed, and other adverse effects due to bleed-out are caused.

On the other hand, a resin layer made of another resin or a surface layer made of polyolefin not containing an ultraviolet absorber is provided as a protective layer on the surface of the polyolefin sheet, or the molecular weight of the ultraviolet absorber used is limited. Various proposals have been made to solve the problem of bleed-out of weathering agents (see, for example, Patent Documents 5 to 7).

For example, in Patent Document 5, a transparent containing only a hindered amine radical scavenger on a transparent olefin resin layer (intermediate layer) containing both a hindered amine radical scavenger as a light stabilizer and an ultraviolet absorber. Proposals have been made to suppress bleeding out of the ultraviolet absorbent added to the intermediate layer to the decorative sheet surface by providing the olefin-based resin layer (surface layer).

Certainly, this method can suppress bleeding out of the UV absorber and hindered amine light stabilizer in the intermediate layer, but the problem of bleeding out of the hindered amine light stabilizer in the surface layer remains. In general, since a hindered amine light stabilizer and an ultraviolet absorber have a synergistic effect on the function, when this decorative sheet is used as a building material for exterior use, the surface to which no ultraviolet absorber is added is used. When the layer was on the surface, the weather resistance of the surface layer was lower than that of the intermediate layer, resulting in physical property deterioration, gloss change, cracking, choking, etc. due to embrittlement of the polyolefin resin sheet, Appearance is impaired. For this reason, it was not a decorative sheet having both bleed-out resistance and weather resistance on the surface, which is required as a decorative sheet that can withstand exterior applications.
JP-A-2-128843 JP-A-6-1881 JP-A-6-198831 JP 9-328562 A JP-A-11-147292 JP-A-11-216812 JP 2001-40113 A

  The present invention has been made to solve the above-mentioned problems, and the problem is that a decorative sheet having excellent weather resistance, in particular, the weather resistance is required for a surface material of a building material for exterior use. Another object of the present invention is to provide a decorative sheet characterized in that it can sufficiently satisfy the weather resistance.

  In the invention according to claim 1, at least a protective layer made of a transparent or translucent resin in which a hindered amine light stabilizer is copolymerized is laminated on a base sheet, and the protective layer is a triazine type. A decorative sheet comprising at least one ultraviolet absorber selected from the group consisting of an ultraviolet absorber, a benzotriazole-based ultraviolet absorber, and an inorganic ultraviolet absorber made of a metal oxide.

  The invention according to claim 2 is the decorative sheet according to claim 1, wherein the protective layer contains a hindered amine light stabilizer that is not copolymerized with the resin.

  In the invention according to claim 3, at least a transparent or translucent thermoplastic resin layer is laminated between the base sheet and the protective layer, and the thermoplastic resin layer is composed of a triazine ultraviolet absorber, benzotriazole. It contains at least one ultraviolet absorber selected from a group consisting of a series ultraviolet absorber and an inorganic ultraviolet absorber made of a metal oxide, and a hindered amine light stabilizer. The decorative sheet according to any one of the above.

  The invention according to claim 4 is the decorative sheet according to claim 3, wherein the thermoplastic resin layer is composed of at least a polyolefin-based resin.

  The invention according to claim 5 is the decorative sheet according to any one of claims 1 to 4, wherein a pattern layer is provided on the base sheet.

In the invention according to claim 1, at least a protective layer made of a transparent or translucent resin in which a hindered amine light stabilizer is copolymerized is laminated on a base sheet, and the protective layer is a triazine type. A decorative sheet comprising at least one ultraviolet absorber selected from the group consisting of an ultraviolet absorber, a benzotriazole-based ultraviolet absorber, and an inorganic ultraviolet absorber made of a metal oxide. According to the invention of the decorative sheet according to claim 1, at least a protective layer containing a transparent or translucent resin copolymerized with a hindered amine light stabilizer is laminated on the base sheet, and the protective layer Is characterized by containing at least one UV absorber selected from the group consisting of triazine-based UV absorbers, benzotriazole-based UV absorbers, and inorganic UV absorbers composed of metal oxides. Therefore, it is possible to provide a decorative sheet excellent in weather resistance having a sufficient ultraviolet ray absorbing ability.

The invention according to claim 2 is the decorative sheet according to claim 1, wherein the protective layer contains a hindered amine light stabilizer that is not copolymerized with the resin. According to the decorative sheet invention of claim 2, since the protective layer contains a hindered amine light stabilizer that is not copolymerized with the resin, the protective layer is formed on the outermost surface where photodegradation starts. Since the hindered amine light stabilizer which is not polymerized and can move freely moves and can keep the stabilizer concentration on the outermost surface high, the weather resistance can be further improved when combined with the decorative sheet of claim 1. .

In the invention according to claim 3, at least a transparent or translucent thermoplastic resin layer is laminated between the base sheet and the protective layer, and the thermoplastic resin layer is composed of a triazine ultraviolet absorber, benzotriazole. It contains at least one ultraviolet absorber selected from a group consisting of a series ultraviolet absorber and an inorganic ultraviolet absorber made of a metal oxide, and a hindered amine light stabilizer. The decorative sheet according to any one of the above. According to the invention of the decorative sheet according to claim 3, at least a thermoplastic resin layer is laminated between the base sheet and the protective layer, and the thermoplastic resin layer includes a triazine ultraviolet absorber, a benzotriazole type. The weather resistance can be further improved by containing at least one ultraviolet absorber selected from the group consisting of an ultraviolet absorber and an inorganic ultraviolet absorber consisting of a metal oxide and a hindered amine light stabilizer.

  The invention according to claim 4 is the decorative sheet according to claim 3, wherein the thermoplastic resin layer is composed of at least a polyolefin-based resin. According to the decorative sheet invention of claim 4, since the thermoplastic resin layer is a polyolefin resin, it is possible to provide a decorative sheet having a low environmental load without using a vinyl chloride resin. Is possible.

  The invention according to claim 5 is the decorative sheet according to any one of claims 1 to 4, wherein a pattern layer is provided on the base sheet. Since the pattern layer is provided on the base material sheet, it is possible to provide a decorative sheet having high design properties.

  Hereinafter, the decorative sheet of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic sectional configuration of a decorative sheet according to the present invention. The decorative sheet is provided with a pattern layer 5, an adhesive layer 4, an adhesive resin layer 3, a thermoplastic resin layer 2, and a protective layer 1 sequentially laminated on one surface side of the base sheet 6. A primer layer 7 is laminated on the other surface side of the base sheet 6. Note that the decorative sheet shown in the figure shows an example of the present invention, and is not necessarily limited to such a configuration.

  As the base sheet 6, paper such as thin paper, titanium paper, resin-impregnated paper, polyolefin resin such as polyethylene, polypropylene, polyolefin-based thermoplastic elastomer, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer , Polyvinyl alcohol, acrylic resin, or a sheet made of a foam of these resins, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer Arbitrary ones can be selected from polymer rubber, styrene-butadiene-styrene block copolymer rubber, sheets made of rubber such as polyurethane, and the like.

  In the base material sheet 6, in order to improve machinability, an organic component filler, an inorganic filler, or the like may be added. For example, examples of the organic component filler include urethane crosslinked particles, acrylic crosslinked particles, melamine resin, and natural collagen. Examples of the inorganic filler include alumina, silica, silicon nitride, silicon carbide, glass beads, aluminum hydroxide, calcium carbonate and the like, which are constituent materials of general topcoat agents. Moreover, the resin which comprises a base material sheet has transparency, The pigment etc. for giving concealment property to a sheet | seat may be added.

The primer layer 7 is provided on the surface of the base sheet 6 opposite to the surface on which the transparent or translucent thermoplastic resin layer 2 is provided. The primer layer 7 is composed of a conventionally known easy-adhesive primer agent mainly composed of, for example, a urethane resin, an acrylic resin, an ethylene-vinyl acetate resin, a polyester resin, or the like. If an inorganic fine powder such as silica is added to the primer layer 7 and the surface thereof is roughened, it becomes difficult for blocking to occur during winding and storage of the decorative sheet, and further adhesion due to the anchoring effect. The improvement of the property is intended.

  The pattern layer 5 is provided on one side of the base sheet 6 having such a configuration. As the form of the picture layer 5, it is a layered pattern with a predetermined picture shape, a solid pattern on the entire surface, or a combination of a pattern-shaped part and a solid-shaped part as appropriate. There is something that has become.

A printing ink is mentioned as a formation material of the pattern layer 5 which becomes such a structure. The printing ink is obtained by adding a colorant such as a pigment and a dye, an extender pigment, a solvent, and various additives into a binder. Examples of the binder include resins such as nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, and polyester, and modified products thereof. One or several of these may be selected and used in combination, and these may be aqueous, solvent-based, or emulsion-based, and even one-component type or two-component using a curing agent. It may be of a type. Furthermore, as the curing type, a type that cures by irradiation with active energy rays such as ultraviolet rays and electron beams, and a type that is isocyanate cured with a urethane-based one can be used. Among the types in which the formed thin film is cured by irradiation with active energy rays such as ultraviolet rays and electron beams, those cured with electron beams are more easily cured in the thickness direction than those cured with ultraviolet rays and are preferably used. .

Examples of the pigment include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, mica and the like.

Examples of the method for providing the pattern layer 5 include gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and ink jet printing. When a solid pattern layer is provided, a coating method such as a comma coater, a knife coater, or a lip coater, or a metal vapor deposition method or a sputtering method may be used. In selecting the material for forming the pattern layer, the adhesiveness with other layers adjacent to the pattern layer should be sufficiently considered.

In addition, the ink for obtaining the pattern layer formed in a solid shape may be basically the same as the ink used for forming the pattern layer in the pattern shape, but the material composition thereof may be the same. When the layer needs to be concealed, an opaque pigment, titanium oxide, iron oxide or the like may be used as the pigment to be included. Further, fine powder made of metal such as gold, silver, copper, and aluminum may be used to provide concealment. Among these, flaky aluminum can be preferably used. The thickness of the solid pattern layer formed mainly for concealment is preferably about 2 to 10 μm. When the thickness is less than 2 μm, it is difficult to impart concealability, and when it exceeds 10 μm, the cohesive force of the layer becomes weak.

A transparent or translucent thermoplastic resin layer 2 is laminated on such a pattern layer 5 via an adhesive layer 4 and an adhesive resin layer 3 described later.

The resin material used as one of the constituent materials of the thermoplastic resin layer 2 includes polyolefin resins such as polyethylene, polypropylene, polyolefin thermoplastic elastomer, polystyrene, polycarbonate, polyester, polyamide, and ethylene-vinyl acetate copolymer. In addition, known thermoplastic resins such as polyvinyl alcohol can be mentioned, and among them, polyolefin resins can be preferably used. Of the polyolefin resins, polypropylene is also preferably used. More specifically, it is a homopolymer, ie, a homopolymer or a binary or ternary random polymer copolymer copolymerized with ethylene, butene or the like.

In particular, the use of highly crystallized polypropylene is preferred when it is desired to give the decorative sheet superior surface strength. It is possible to add other resins to this highly crystallized polypropylene. However, when it is desired to provide post-processing suitability such as bending, pay sufficient attention to the compatibility with the highly crystallized polypropylene resin. Should.

The thermoplastic resin layer 2 in the present invention has a role of improving weather resistance, and an ultraviolet absorber and a hindered amine light stabilizer are appropriately added. As the ultraviolet absorber, a triazine ultraviolet absorber, a benzotriazole ultraviolet absorber, or an inorganic ultraviolet absorber made of a metal oxide can be used alone or in combination.

Examples of the triazine ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2- [4-[(2- Hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy- 3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4dimethylphenyl) -1,3,5-triazine, 2,4-bis (2,4-dimethylphenyl) -6- (2-hydroxy-4-iso-octyloxyphenyl) -s-triazine, 2- [4,6-bis (2,4-dimethylphenyl) 1,3,5-triazin-2-yl]- 5- (Oct Oxy) phenol and the like, and mixtures thereof, modified products, polymers, derivatives. One or more of these may be selected and used.

The amount of the triazine-based ultraviolet absorber added in the thermoplastic resin layer 2 is preferably 0.1 parts by weight or more with respect to 100 parts by weight of the thermoplastic resin. When the addition amount is less than 0.1 parts by weight, there may be a case where sufficient ultraviolet absorbing ability cannot be exhibited in the thermoplastic resin layer. The upper limit of the addition amount of the triazine-based ultraviolet absorber is preferably 1 part by weight or less.

On the other hand, as the benzotriazole-based ultraviolet absorber, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl) -1-phenylethyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H-benzotriazol-yl)- 4,6-di-tert-pentylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, mixtures thereof, modified products, polymerization Products and derivatives. One or more of these may be selected and used.

The addition amount of these benzotriazole-based ultraviolet absorbers in the thermoplastic resin layer 2 is preferably 0.1 to 1.0 part by weight with respect to 100 parts by weight of the thermoplastic resin. When the addition amount is less than 0.1 parts by weight, there may be a case where sufficient ultraviolet absorbing ability cannot be exhibited in the thermoplastic resin layer. Moreover, when exceeding 1.0 weight part, the adhesive strength with the other layer adjacent to a thermoplastic resin layer, for example, the protective layer 1 to show in figure, may fall.

Examples of inorganic ultraviolet absorbers made of metal oxides include anatase-type titanium oxide ultrafine particles, rutile-type titanium oxide ultrafine particles, zinc oxide ultrafine particles, cerium oxide ultrafine particles, and mixtures thereof. A material having an energy difference in the band gap of the conduction band equivalent to that in the ultraviolet region of radiation can be used.

Inorganic ultraviolet absorbers made of these metal oxides are suitable because the smaller the primary particle diameter, the less the scattering and the more transparent the light in the visible light region. Conversely, when the primary particle size is increased, it becomes opaque to light in the visible light region, but when the particle size approaches the wavelength in the ultraviolet light region, a scattering effect works and the ultraviolet shielding effect is improved. Therefore, the primary particle size of the inorganic ultraviolet absorbent made of the metal oxide to be added is preferably in the range of 10 nm to 400 nm in consideration of transparency, weather resistance, ultraviolet absorption ability and the like required for the decorative sheet. . The addition amount of the inorganic ultraviolet absorber in the thermoplastic resin layer 2 is preferably 0.1 to 1 part by weight with respect to 100 parts by weight of the thermoplastic resin.
In addition, the total amount of the ultraviolet absorber in the thermoplastic resin layer 2 is preferably 1 part by weight or less with respect to 100 parts by weight of the thermoplastic resin.

In the thermoplastic resin layer 2, as described above, at least one of a triazine-based or benzotriazole-based ultraviolet absorber and an inorganic ultraviolet absorber made of a metal oxide is used alone or in combination as an ultraviolet absorber. While being added, a hindered amine light stabilizer is added.

Examples of hindered amine light stabilizers include dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, poly [{6- (1,1,3,3 -Tetramethylbutyl) amino-1,3,5-triazine-2,4diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6 -Tetramethyl-4-piperidyl) imino}], N, N′-bis (3-aminopropyl) ethylenediamine · 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl) -4 piperidyl) amino] -6-chloro-1,3,5-triazine, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di-t-butyl -4-hydroxybenzyl) 2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3 , 4-butanetetracarboxylate and the like. One or several of these are selected and used together with the above-described ultraviolet absorber. The addition amount of the hindered amine light stabilizer in the thermoplastic resin layer 2 is preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

Further, in the thermoplastic resin layer 2, in addition to the ultraviolet absorber and the light stabilizer described above, an antioxidant, a heat stabilizer, a flame retardant, an anti-blocking agent, a catalyst accelerator, a colorant, A light scattering agent, a gloss adjusting agent, and the like for translucency can be appropriately added within a range that maintains transparency or translucency.

Examples of the antioxidant include various antioxidants such as phenol, sulfur and phosphorus. These antioxidants can be combined with other additives in any combination, but bleed out to the surface of the thermoplastic resin layer by adding a large amount, added colorant, ultraviolet absorber, light stabilizer, etc. It is necessary to pay close attention to synergy and antagonism.

Examples of the heat stabilizer include hindered phenols, sulfurs, and fertilizer resins, and examples of the flame retardant include aluminum hydroxide and magnesium hydroxide. An example of the quencher is a Ni chelate type. In addition to inorganic UV absorbers made of metal oxides, triazine UV absorbers, and benzotriazole UV absorbers, bezoate, benzophenone, salicylate, and cyanoacrylate UV absorbers should be added as appropriate. Is also possible.

Furthermore, in consideration of imparting machinability to the thermoplastic resin layer 2 and improving other physical properties, a filler component may be added in addition to the above-described resins and additives. As this filler, organic crosslinked fillers such as urethane crosslinked particles, acrylic crosslinked particles, melamine resin, natural collagen, and alumina, silica, silicon nitride, which are also used as component materials for general topcoat agents, Examples thereof include inorganic fillers such as silicon carbide, glass beads, aluminum hydroxide, and calcium carbonate.

A known forming method can be used for forming the thermoplastic resin layer 2. For example, an extrusion method or a multilayer coextrusion method performed simultaneously with the formation of an adhesive resin layer described later can be applied. As for the thickness of the thermoplastic resin layer 2, 30-200 micrometers is preferable.

The adhesive resin layer 3 is not necessary when the adhesive strength between the thermoplastic resin layer 2 and the adhesive layer 4 described later is sufficiently obtained. However, when a non-polar resin such as polypropylene is used as the resin constituting the thermoplastic resin layer 2, the adhesive strength between the thermoplastic resin 2 and the adhesive layer 4 cannot be sufficiently obtained. In such a case, it is recommended to provide the adhesive resin layer 3. The adhesive resin layer 3 is made of, for example, a resin such as polypropylene, polyethylene, or acrylic that has been subjected to acid modification. The thickness is preferably 2 μm or more from the viewpoint of improving adhesiveness, but if it is too thick, the flexibility of the adhesive resin layer itself affects the surface hardness, and conversely the adhesive strength is lowered from the viewpoint of cohesive strength and heat resistance. Therefore, the upper limit is preferably about 20 μm. In addition, as a method for forming the adhesive resin layer, in consideration of an improvement in adhesive strength, lamination by a coextrusion method with the thermoplastic resin layer 2 is preferable.

On the other hand, the adhesive layer 4 is a layer provided to improve the adhesive strength between adjacent layers, that is, the pattern layer 5 and the adhesive resin layer 3. As a constituent material of the adhesive layer 4, a known adhesive material can be used as long as sufficient adhesive strength can be obtained. For example, acrylic, polyester, polyurethane, and epoxy adhesive materials can be used. Among them, a two-component curing type polyurethane adhesive material having a high coating cohesive force can be preferably used. Further, the coating method can be appropriately selected depending on the coating liquid viscosity of the adhesive material and the like, but in general, the dry coating method using a gravure plate can be said to be a preferable method from the viewpoint of low coating amount management. The coating amount may be appropriately determined in consideration of adhesive strength, cost, etc., but a coating amount as low as possible is preferable.

The adhesive layer 4 is formed on the pattern layer 5 and is integrally formed with the thermoplastic resin layer 2 and the adhesive resin layer 3. Although the formation method depends on the adhesive resin layer 3 adjacent thereto, it may be formed by extrusion lamination, dry lamination or the like according to the characteristics of the material.

Next, the protective layer 1 provided on the decorative sheet surface will be described. The protective layer 1 is a layer provided for protecting the thermoplastic resin and the pattern layer from being deteriorated by ultraviolet rays, improving the stain resistance, and further adjusting the gloss of the surface, and is a crosslinked resin material. And a protective layer forming material containing an ultraviolet absorber, a light stabilizer and the like. Examples of main constituent materials include polyurethane, acrylic silicon, fluorine, epoxy, vinyl, polyester, melamine, aminoalkyd, and urea resin materials. The form of the material for forming the protective layer mainly composed of these resins may be any of water, emulsion, solvent, etc., and the curing type is a one-component type or a two-component type using a curing agent. But you can. Among these, a protective layer mainly composed of a urethane-based resin using isocyanate can be said to be desirable from the viewpoints of workability in formation, cost, cohesion of the resin itself, and the like.

Examples of the isocyanate described above include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), metadiisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), and methylhexane diisocyanate (HTDI). ), Methylcyclohexanone diisocyanate (HXDI), trimethylhexamethylene diisocyanate (TMDI), etc., and an appropriate one can be selected from these, but considering the weather resistance, it is more straightforward than the type having a double bond. A type having a chain structure, particularly hexamethylene diisocyanate (HMDI) is preferred. Further, in order to further improve the surface hardness, it is possible to use a resin that is cured by an active energy ray such as an ultraviolet ray or an electron beam. In addition to the single use, the combined use of the thermosetting type and the photocuring type hybrid curing type may be effective from the viewpoint of surface hardness, curing shrinkage, adhesion and the like.

In order to improve the weather resistance, ultraviolet absorbers such as triazine, benzophenone, and benzotriazole and hindered amine light stabilizers are added to the protective layer of the conventional decorative sheet. In particular, the hindered amine light stabilizer has an effect of preventing deterioration of the protective layer itself, and plays an important role of preventing deterioration of the protective layer that is most likely to be deteriorated because it is on the surface. However, since these protective layers are thin, ultraviolet absorbers and hindered amine light stabilizers are easily washed out of the layer by bleeding out due to exposure to heat, light, rain, etc. from the outside. The amount of addition decreased, and deterioration occurred in the protective layer and the thermoplastic resin layer and printed layer laminated under the protective layer.

On the other hand, in the present invention, the transparent or translucent resin used for the protective layer 1 is copolymerized with a hindered amine light stabilizer, so that the light stabilizer bleed added to the protective layer is bled. It has become possible to provide a decorative sheet excellent in weather resistance having a sufficient resin protective effect.

An example of obtaining a resin in which the hindered amine light stabilizer according to the present invention is copolymerized is a method of copolymerizing a monomeric hindered amine light stabilizer when synthesizing a resin used for the protective layer. is there.

As these hindered amine light stabilizers, N- (2,2,6,6-tetramethylpiperidinyl) N′-aminooxamide, (2,2,6,6-tetramethyl-4-piperidyl) Examples thereof include methacrylate, (1,2,2,6,6-pentamethyl-4-piperidyl) methacrylate, and mixtures, modified products, polymers, derivatives and the like containing the methacrylate. These can also be used alone or in combination. The amount of the hindered amine light stabilizer copolymerized with the resin of the protective layer 1 is preferably 0.1 to 20 parts by weight relative to the weight of the protective layer 1.

In addition to the hindered amine light stabilizer copolymerized with the resin, a hindered amine light stabilizer that is not crosslinked or copolymerized with the resin may be added to the protective layer 1.

These hindered amine light stabilizers include bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl. ] Butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis-decanoic acid bis [ 2,2,6,6-tetramethyl-1-octyloxy) -4-piperidinyl] ester and the like, mixtures, modified products, polymers, derivatives and the like thereof. These can also be used alone or in combination. The amount of the hindered amine light stabilizer added to the protective layer 1 is preferably 0.1 to 20 parts by weight with respect to the weight of the protective layer 1.

In addition to the hindered amine light stabilizer, an ultraviolet absorber is appropriately added to the protective layer 1 as a light stabilizer. As the ultraviolet absorber, at least one selected from a triazine ultraviolet absorber, a benzotriazole ultraviolet absorber, and an inorganic ultraviolet absorber made of a metal oxide can be preferably used.

Examples of the triazine-based ultraviolet absorber added to the protective layer 1 include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2 -[4-[(2-hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [ 4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2 Hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, 2,4-bis (2,4-dimethylphenyl) -6 − ( - hydroxy-4-iso - octyloxyphenyl) -s-triazine, and mixtures thereof, modified products, polymers, derivatives and the like. These can be used alone or in combination.

Moreover, as a benzotriazole type ultraviolet absorber added to the protective layer 1, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4- 6-bis (1-methyl-1-phenylethyl) phenol, 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2- (2H -Benzotriazol-yl) -4,6-di-tert-pentylphenol, 2- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol and the like A mixture, a modified product, a polymerized product, and a derivative thereof can be exemplified. These can also be used alone or in combination.

Examples of inorganic ultraviolet absorbers composed of metal oxides added to the protective layer 1 include anatase-type titanium oxide ultrafine particles, rutile-type titanium oxide ultrafine particles, zinc oxide ultrafine particles, cerium oxide ultrafine particles, and mixtures thereof. A semiconductor whose energy difference between the band gap of the valence band and the conduction band is equivalent to that in the ultraviolet region of radiation can be used.

The smaller the primary particle diameter of the inorganic ultraviolet absorber made of a metal oxide, the smaller the scattering, and the more transparent the light in the visible light region is. Conversely, when the primary particle size is increased, it becomes opaque to light in the visible light region, but when the particle size approaches the wavelength in the ultraviolet region, a scattering effect is activated and the ultraviolet shielding effect is improved. The primary particle diameter of the inorganic ultraviolet absorbent made of a metal oxide to be actually added may be appropriately set in consideration of transparency, weather resistance, ultraviolet absorbing ability and the like required for a decorative sheet.

The amount of the triazine-based ultraviolet absorber added to the protective layer 1 is preferably 0.1 to 10 parts by weight with respect to the weight of the protective layer 1. The amount of the benzotriazole-based ultraviolet absorber added to the protective layer 1 is preferably 0.1 to 10 parts by weight with respect to the weight of the protective layer 1. The amount of the inorganic ultraviolet absorber added to the protective layer 1 is preferably 0.1 to 10 parts by weight with respect to the weight of the protective layer 1.
The total amount of the ultraviolet absorber in the protective layer 1 is preferably 10 parts by weight or less with respect to the weight of the protective layer 1.

Moreover, in order to provide various functions, you may add functional additives, such as an antibacterial agent, a fungicide, and a flame retardance, in this protective layer. Furthermore, inorganic fillers such as alumina, silica, silicon nitride, silicon carbide, glass beads, etc. can be added for imparting design properties to the surface, adjusting gloss, and improving wear resistance.

As the flame retardant, aluminum hydroxide, magnesium hydroxide, Ni chelate as a quencher, or the like can be added in any combination. In addition to the triazine-based or benzotriazole-based UV absorber, a benzoate-based, benzophenone-based, salicylate-based, cyanoacrylate-based, or the like can be added in combination as the UV absorber. Specific examples include benzophenone-based octabenzone, modified products, polymers, and derivatives thereof.

Since especially the protective layer 1 is located in the outermost surface, it is a part which has a great influence on provision of the weather resistance of a decorative sheet. Therefore, it is necessary to fully consider weather resistance, and the amount of functional additive added depends on the solubility in the resin and solvent constituting the protective layer-forming material (coating solution), but it depends on the required physical properties and addition of a large amount. Considering the adverse effects, it is preferable to set the amount in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the solid content of the protective layer forming material.

  Also, the method for forming the protective layer may be selected in accordance with the properties, viscosity, coating amount, etc. of the material for forming the protective layer, and it is not necessary to adopt a special coating method. Specifically, it may be provided by a general coating method such as gravure coating, micro gravure coating, comma coating, lip coating or the like. Further, an uneven embossed pattern may be applied to improve the design. Moreover, it is preferable that it is 1-20 micrometers as a film thickness of a protective layer.

  In the case of applying an embossed pattern, there are a method in which each layer is once laminated by various methods and then embossed by hot pressure, a method in which an uneven pattern is provided on a cooling roll and embossed simultaneously with extrusion lamination. In addition, there is a method in which a transparent resin layer and a base sheet that are simultaneously embossed at the time of extrusion are bonded together by heat or dry lamination. Further, ink or resin may be embedded in the embossed recesses, and the ink or resin in the recesses may be transferred to improve the design and weather resistance.

  The term “transparent or translucent” as used in the present invention means that the total light transmittance defined in JIS K7105 is 75% or more.

  EXAMPLES Hereinafter, although an Example and a comparative example further demonstrate this invention, this invention is not restrict | limited to the following example.

First, as a thermoplastic resin layer forming material, a benzotriazole-based ultraviolet absorber 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl is used with respect to 100 parts by weight of a homotype polypropylene resin for extrusion molding. 0.5 parts by weight of -6- (tert-butyl) phenol, hindered amine light stabilizer (poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5- Triazine-2,4diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}]). A resin to which 0.5 part by weight of phenol-based antioxidant (Irganox 1010: manufactured by Ciba Specialty Chemicals Co., Ltd.) was added was used.

Next, a pattern layer with a wood grain pattern is provided on the surface of a base material sheet (thickness 120 μm) made of polyethylene, and an adhesive layer having a thickness of about 2 μm made of a two-component curable urethane resin adhesive is provided thereon. A base sheet made of polyethylene was prepared.

Subsequently, a polypropylene acid-modified resin was used as the adhesive resin layer forming material, and the resin composition was used as the thermoplastic resin layer forming material, and melt extrusion was performed with an extruder. On the adhesive layer of the material sheet, an adhesive resin layer and a thermoplastic resin layer were formed by a multilayer extrusion lamination method. At this time, the thicknesses of the formed adhesive resin layer and thermoplastic resin layer were 10 μm and 80 μm, respectively.

The surface of the thermoplastic resin layer of the multilayer sheet obtained in the above step is subjected to corona discharge treatment, and a triazine ultraviolet absorber (2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2 -Hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine) and a hindered amine light stabilizer (2,2,6,6-tetramethyl-4- A topcoat agent obtained by copolymerizing piperidyl methacrylate with a resin was dry-coated to provide a protective layer, and a decorative sheet according to Example 1 of the present invention was produced. The triazine ultraviolet absorber and the hindered amine light stabilizer were added so as to be 5 parts by weight and 5 parts by weight, respectively, with respect to the weight of the protective layer.

  As the material for the protective layer, the same triazine ultraviolet absorber as in Example 1, a hindered amine light stabilizer (bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate) and a hindered amine light stabilizer (2,2,6,6-tetramethyl-4-piperidyl) methacrylate in the resin. A decorative sheet according to Comparative Example 1 for comparison was prepared by using the same topcoat agent obtained by copolymerizing a polymerized topcoat agent with a resin and using the same materials and production methods as in Example 1. The triazine UV absorber is 5 parts by weight based on the weight of the protective layer, the hindered amine light stabilizer that does not react with the resin is 2.5 parts by weight based on the weight of the protective layer, and the hindered amine light stabilizer copolymerized with the resin. The agent was added so as to be 2.5 parts by weight with respect to the weight of the protective layer.

<Comparative Example 1>
As the material for the protective layer, the same triazine ultraviolet absorber as in Example 1, a hindered amine light stabilizer (bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl 1, 2, 2, 6, 6-pentamethyl-4-piperidinyl) sebacate-containing two-component curable urethane-based topcoat agent, and the other materials and production methods are the same as in Example 1. A decorative sheet according to Comparative Example 1 for comparison was prepared. The triazine ultraviolet absorber and the hindered amine light stabilizer were added so as to be 5 parts by weight and 5 parts by weight, respectively, with respect to the weight of the protective layer, as in Example 1.

(Performance evaluation)
For each decorative sheet of Example 1, Example 2 and Comparative Example 1 produced as described above, a weather resistance acceleration test (metal halide lamp type tester JTM G 01 2000 Japan Testing Machine Industry Association Standard) ) As a tester, a die plastic metal weather (KU-R5CI-A: manufactured by Daipura Wintes Co., Ltd.) was used.
The weathering acceleration test conditions were as follows.
[1] Light source lamp: MW-60W, filter: KF-1 (irradiation range 295 nm to 780 nm), illuminance 65 ± 3 mW / cm ² (measurement range 330 nm to 390 nm)
[2] Light (irradiation) (53 ° C, 50% RH) 20.00 hours [3] Dew (dark condensation) (30 ° C, 98% RH) 4.00 hours [4] Rest (rest) (30 ° C, 98% RH) 0.01 hour The weather resistance acceleration test was performed with the cycle of 24.01 hours shown above as one cycle. The shower was performed for 30 seconds before and after Dew.

  The time until the surface cracking of the protective layer occurred in the weather resistance acceleration test was measured. The results are shown in Table 1.

  Moreover, about the decorative sheet of Example 1, Example 2 and Comparative Example 1 in which the weather resistance acceleration test was conducted for 240 hours, the adhesiveness of the protective layer was improved by a method without cross-cut according to JISK5600-5-6. evaluated. The evaluation is shown in Table 1.

  From the above results, the decorative sheet according to the present invention is suppressed from deterioration of the protective layer after the weather resistance test, and the adhesive layer is prevented from lowering the adhesion strength, as compared with the decorative sheet prepared for comparison. I understood it.

  The decorative sheet of the present invention is a decorative sheet used as a construction material such as an interior / exterior member for construction, joinery, frame material, flooring, or a surface material for home appliances, in particular, a wooden board, an inorganic board, a metal plate. It is useful for a decorative sheet used when a decorative board is produced by laminating to a sheet, etc., and the weather resistance can sufficiently satisfy the weather resistance required for a surface material of a building material for exterior use. .

It is a schematic sectional drawing of an example of the decorative sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Protective layer 2 ... Thermoplastic resin layer 3 ... Adhesive resin layer 4 ... Adhesive layer 5 ... Picture layer 6 ... Base material sheet 7 ... Primer layer

Claims (5)

At least a protective layer made of a transparent or translucent resin copolymerized with a hindered amine light stabilizer is laminated on the base sheet, and the protective layer is composed of a triazine ultraviolet absorber, a benzotriazole ultraviolet absorber. A decorative sheet comprising an agent and at least one ultraviolet absorber selected from the group consisting of inorganic ultraviolet absorbers made of metal oxides.   The decorative sheet according to claim 1, wherein the protective layer contains a hindered amine light stabilizer that is not copolymerized with the resin.   At least a transparent or translucent thermoplastic resin layer is laminated between the base sheet and the protective layer, and the thermoplastic resin layer is composed of a triazine ultraviolet absorber, a benzotriazole ultraviolet absorber, and a metal oxide. The cosmetic sheet according to claim 1, comprising at least one ultraviolet absorber selected from a group consisting of inorganic ultraviolet absorbers and a hindered amine light stabilizer.   The decorative sheet according to claim 3, wherein the thermoplastic resin layer is composed of at least a polyolefin-based resin.   The decorative sheet according to any one of claims 1 to 4, wherein a pattern layer is provided on the base sheet.