JP2000071391A - Decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide excellent surface physical properties withstanding a severe use, for example, in a doorsill, a top plate, a floor panel or a footboard of stairs while providing flexibility generally reguired in a decorative sheet. SOLUTION: A decorative sheet is constituted by providing a surface protective layer 3 comprising an ionizing radiation curable resin on a thermoplastic resin layer 1 provided with a pattern layer 4 if necessary through an intermediate layer 2 pref. formed from a resin compsn. containing a polymerizable double bond, an active hydrogen group and an isocyanate group. Especially, a polyolefinic resin is pref. used in the thermoplastic resin layer 1 in this decorative sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sheet used for the purpose of surface decoration of building materials such as interior and exterior of buildings, fittings, construction materials, etc., furniture and fixtures, housing equipment and home appliances. In more detail, of course, for general use,
In particular, the present invention relates to a decorative sheet having excellent surface physical properties, which can be used for applications such as shoe sliding, top boards, floor boards, and stair steps requiring abrasion resistance.

[0002]

2. Description of the Related Art Conventionally, as a decorative sheet according to the related art, for example, various types of decorative processing such as printing of a pattern and embossing of a surface on a film or sheet made of a thermoplastic resin such as a polyvinyl chloride resin are performed. Decorative sheets are widely used. Such a decorative sheet has, for example, appropriate flexibility and adhesiveness for secondary processing such as lamination processing and V-cut processing on a base material, workability such as cutting property, break resistance,
Various excellent properties such as weather resistance, light resistance, heat resistance, water resistance, solvent resistance, surface hardness, abrasion resistance, and abrasion resistance in use conditions vary depending on the application.

In order to satisfy such various required characteristics, conventionally, as a thermoplastic resin constituting such a decorative sheet,
Polyvinyl chloride resins having a good balance of various physical and chemical properties have been almost exclusively used. However, in recent years, problems have been pointed out that polyvinyl chloride resin may generate toxic gases such as chlorine gas and hydrogen chloride gas and highly toxic substances such as dioxin during combustion. It has been demanded to switch to a decorative sheet made of non-halogen resin containing no chlorine.

In order to meet such demands, in recent years, decorative sheets using non-halogen thermoplastic resins, such as polyolefin resins, polyester resins, and acrylic resins, in place of the polyvinyl chloride resins, have been developed. Various proposals have been made and put to practical use. Among them, those using a polyolefin-based resin which is closest to polyvinyl chloride resin in various physical properties and which is inexpensive are the most promising. As such a polyolefin resin, a general-purpose polyethylene resin or polypropylene resin may be insufficient in various physical properties, and in many cases, for example, by adding an amorphous soft component or an elastomer component such as a diene-based component. Efforts have been made to improve the properties of resins and to achieve properties closer to those of polyvinyl chloride resins.

[0005] However, even in the case of the above-mentioned various kinds of substitute resins, there is no fact that a resin satisfying the same characteristics as the conventional polyvinyl chloride resin has not been obtained. That is,
In the conventional polyvinyl chloride resin, a resin having any desired physical properties can be obtained relatively easily by changing the compounding of an additive such as a plasticizer. The range of adjustment of physical properties by changing the composition of the agent or modifying the resin is relatively narrow, for example, the flexibility required for the suitability for secondary processing and the scratch resistance and abrasion resistance required for use As described above, a resin that simultaneously satisfies a plurality of essentially contradictory properties has not yet been obtained.

[0006] Therefore, while the resin itself is required to sufficiently satisfy the flexibility required for processability, the abrasion resistance and abrasion resistance required for use are determined by the surface resistance of the resin layer. Attempts have been made to provide a surface protective layer made of a hard resin having excellent scratch resistance and abrasion resistance. More specifically, a method of applying a mixed composition of a polyol compound and an isocyanate group-containing compound and applying a two-component thermosetting urethane resin-based top coat layer obtained by crosslinking and curing is most commonly used. I have.

However, a so-called semi-rigid polyvinyl chloride resin to which a plasticizer such as a phthalate ester is added at about 20 PHR, which is the most typical constituent resin of a conventional polyvinyl chloride resin-based decorative sheet, has a pencil hardness. While having a surface hardness of about 2B to HB, for example, a polyolefin resin modified to obtain the same flexibility as a polyvinyl chloride resin generally has a surface hardness of about 6B to 4B with a pencil hardness of about 6B to 4B. Hardness can only be obtained, and no matter how hard a urethane-based topcoat agent is selected and a topcoat layer is applied, there is naturally a limit to the surface hardness that can be obtained. Realizing a decorative sheet that can be fully used for applications such as Kutsuzuri, top plate, floor plate, stair tread, etc., which was used by further applying a urethane top coat layer to the sheet It was of a very difficult situation.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art, and has the flexibility generally required for a decorative sheet, for example. It is an object of the present invention to provide a decorative sheet having excellent surface properties that can withstand severe uses such as a top plate, a floor plate, a step board and the like.

[0009]

Means for Solving the Problems The present invention is a decorative sheet comprising a thermoplastic resin layer and a surface protective layer made of an ionizing radiation curable resin.

[0010] The present invention also relates to the above decorative sheet,
A decorative sheet comprising an intermediate layer made of an acrylic resin or a urethane resin between the thermoplastic resin layer and the surface protective layer.

Further, the present invention provides the above decorative sheet,
The decorative sheet is characterized in that the intermediate layer is formed from a resin composition containing an active hydrogen group and an isocyanate group.

Further, the present invention provides the above decorative sheet,
A decorative sheet, wherein the intermediate layer is further formed from a resin composition containing a polymerizable double bond.

[0013] The present invention also provides the above decorative sheet,
The decorative sheet is characterized in that the thermoplastic resin layer is made of a polyolefin-based resin.

[0014]

FIG. 1 shows an example of an embodiment of a decorative sheet according to the present invention. The decorative sheet 4 has a transparent or translucent thermoplastic resin layer 1 provided with an appropriate pattern layer 4. On the surface, a surface protective layer 3 made of an ionizing radiation-curable resin cured by irradiation with ultraviolet rays or electron beams or the like is provided.

As the thermoplastic resin constituting the thermoplastic resin layer 1, any known thermoplastic resin which has conventionally been generally used as a constituent material of a decorative sheet can be used. Specifically, for example, polyolefin resins such as polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene-1, ethylene-vinyl acetate copolymer or a saponified product thereof, and ethylene- (meth) acrylate (ester) copolymer Olefin copolymers such as polymers, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, and polycarbonate; acrylic resins such as polymethyl methacrylate; styrene such as polystyrene, AS resin, and ABS resin Resins, polyamide resins such as 6-nylon, 6,6-nylon and 6,10-nylon, cellulose derivatives such as acetate cellulose and nitrate cellulose, chlorine resins such as polyvinyl chloride and polyvinylidene chloride, Polyvinyl fluoride, polyvinyl fluoride Fluorinated resins such as lidene, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, and the like, or various mixtures, copolymers, composites, and laminates thereof Can be used.

However, as already mentioned in the section of the prior art, the use of the above-mentioned chlorine-based resin or fluorine-based resin is not so much considered in view of the response to the environmental problem that has been rapidly gaining public interest in recent years. It is not preferable to use a resin containing no halogen element such as chlorine or fluorine, that is, a non-halogen resin. Above all,
As seen from various aspects such as a balance of moderate flexibility and strength as a material for decorative sheets, workability such as bending, cutting and cutting, surface properties such as abrasion resistance and solvent resistance, weather resistance, etc. Olefin resins are the best.

As such an olefin resin, various homopolymers and copolymers including the above-mentioned ones are known. Among them, the most suitable as a material for a decorative sheet is a polypropylene resin, that is, a resin mainly composed of polypropylene. A homopolypropylene resin, a random polypropylene resin, a block polypropylene resin, and a polypropylene having a crystal part, and α- having 2 to 20 carbon atoms other than propylene.
Propylene-α- containing at least 15 mol% of a comonomer of an olefin, preferably ethylene, butene-1, 4-methylpentene-1, hexene-1 or octene-1.
Olefin copolymers and the like can be exemplified. It is also possible to add modifiers such as ethylene-α-olefin copolymer, ethylene-propylene copolymer rubber, ethylene-propylene-non-conjugated diene copolymer rubber which are usually used for softening a polypropylene resin. .

The thermoplastic resin constituting the thermoplastic resin layer 1 may include, for example, an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a plasticizer, One or more kinds of conventionally known various additives such as a lubricant, an antistatic agent, a flame retardant, and a filler may be added.

As the antioxidant, for example, a phenol type,
For example, benzophenone, benzotriazole, salicylate, etc.
Cyanoacrylates, formamidines, oxanilides, etc., as light stabilizers, for example, hindered amines,
For example, a hindered phenol type, a sulfur type, a hydrazine type, etc. as a heat stabilizer, a phthalate ester type, a phosphate ester type, a fatty acid ester type, a fat, etc. Group A dibasic acid ester type, oxybenzoic acid ester type, epoxy type, polyester type, etc. Examples of the lubricant include fatty acid ester type, fatty acid type, metal soap type, fatty acid amide type, higher alcohol type, paraffin type, etc. As, for example, cationic, anionic, nonionic, zwitterionic, etc.
Examples of the flame retardant include bromine, phosphorus, chlorine, nitrogen, aluminum, antimony, magnesium,
As a filler such as a boron-based or zirconium-based filler, for example, one or a mixture of two or more selected from calcium carbonate, talc, rubble, kaolin and the like is used.

The thickness of the thermoplastic resin layer 1 is not particularly limited, and a thickness similar to that of a conventional general decorative sheet can be used. Specifically, although it depends on the use of the decorative sheet and the type of resin, it is usually 20 to 300 μm.
It is generally selected from a range of degrees.

The pattern layer 4 is provided for the purpose of imparting a desired design to the decorative sheet, and there are no particular restrictions on the type of the pattern, the constituent material of the pattern layer 1, the forming method, and the like. For example, it can be provided in exactly the same manner as a conventionally known decorative sheet. Specific examples of the type of picture include a wood grain pattern, a stone grain pattern, an abstract pattern, a geometric pattern, and a plain solid color. Of course, when there is no need for a picture, the picture layer 4 may not be provided.

In general, a printing ink or coating agent obtained by dissolving or dispersing a colorant such as a dye or a pigment in a suitable solvent together with a suitable binder resin is used as a constituent material of the picture layer 4. Is done. Examples of the coloring agent include inorganic pigments such as carbon black, titanium white, zinc white, red iron oxide, graphite, navy blue, and cadmium red, azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazines. Organic pigments such as pigments, or a mixture of two or more thereof can be used.

As the binder resin, for example, acrylic resin, styrene resin, polyester resin,
Urethane resin, polyvinyl resin, alkyd resin,
Petroleum resin, ketone resin, epoxy resin, melamine resin, fluorine resin, silicone resin, cellulose derivative,
Various synthetic resins such as synthetic rubbers, or mixtures and copolymers thereof can be used. In addition, as the solvent, for example, toluene, xylene, cyclohexane, ethyl acetate, butyl acetate, methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, or the like, or a mixture thereof, or the like may be used. Can be. In addition, various additives such as extenders, plasticizers, dispersants, surfactants, tackifiers, adhesion aids, curing agents, curing accelerators, or curing retarders can also be added as needed.

The method of forming the picture layer 4 is most commonly performed by various appropriate printing methods such as a gravure printing method, an offset printing method, a screen printing method, a flexographic printing method, an electrostatic printing method and an ink jet printing method. However, in the present invention is not necessarily limited to these,
For example, when the entire surface is solid, various coating methods such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating are applied. It is also possible. Further, in addition to the above-described printing method or coating method, for example, a hand-drawing method, a sinking method, a photographic method, a laser beam or electron beam drawing method, a partial vapor deposition method of metal or the like, an etching method, or a combination of a plurality of these methods. You can do it too.

When the pattern layer 4 and the like are applied to the thermoplastic resin layer 1, the surface of the thermoplastic resin layer 1 is subjected to, for example, corona treatment, ozone treatment, plasma treatment, ionizing radiation treatment, or the like.
By performing an appropriate surface treatment such as a dichromic acid treatment, an anchor or a primer treatment, the adhesiveness between the thermoplastic resin layer 1 and the picture layer 4 or the like can be improved.

In general, a decorative sheet as in the present invention is often required to have a predetermined concealing property in order to conceal undesired colors, scratches and other defects on the surface of various substrates to be affixed. For the purpose of imparting the required concealing property to such a decorative sheet, a concealing layer 5 can be provided separately from the above-described picture layer 4. The concealing layer 5 is provided by printing or coating a concealing printing ink or coating agent in a solid state, as is well known in the art.

The above-mentioned opaque printing ink or coating agent is a printing ink or coating agent in which a opaque pigment having a higher refractive index than a commonly used binder resin is dispersed at a high concentration. For example, it is desirable to use at least an inorganic pigment such as a titanium oxide-based or iron oxide-based pigment and / or a metal powder pigment such as a flaky aluminum powder. As the binder resin, the solvent, the additive, and the like, the same ones as in the case of the printing ink or the coating agent used in the picture layer 4 described above can be used. As the printing method or the coating method for providing the concealing layer 5, similarly to the pattern layer 4, any conventionally known printing method or coating method can be appropriately applied.

In the decorative sheet of the present invention, a surface protective layer 3 made of an ionizing radiation curable resin is provided on the surface of the thermoplastic resin layer 1 described above. The ionizing radiation-curable resin used for the surface protective layer 3 may be a prepolymer, an oligomer and / or a monomer having a polymerizable unsaturated bond which reacts by the action of ionizing radiation such as ultraviolet rays or electron beams in the resin molecules. The composition is composed mainly of the compounded composition and, if necessary, additives such as a photopolymerization initiator and a photosensitizer.

Here, examples of the prepolymer or oligomer include acrylates such as polyester acrylate, urethane acrylate and epoxy acrylate, and methacrylates such as polyester methacrylate, urethane methacrylate and epoxy methacrylate.

Further, as the monomer, for example, n-
Alkyl acrylate, isopropyl acrylate, isobutyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, β-hydroxyethyl acrylate, diethylene glycol acrylate,
Polyethylene glycol acrylate, β-hydroxypropyl acrylate, glycidyl acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dialkylaminoethyl acrylate, 2-cyanoethyl acrylate, β
-Ethoxyethyl acrylate, aryl acrylate, benzoyloxyethyl acrylate, benzyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl alcohol / ε-caprolactone adduct acrylate , Isobornyl acrylate, dicyclopentenyloxyethyl acrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9
-Nonanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate, acetal glycol diacrylate, neopentyl glycol hydroxypivalate-ε
-Caprolactone adduct acrylate, trimethylolpropane triacrylate, trimethylolpropane polyethoxylate triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, dipentaerythrylate-ε-caprolactone adduct hexaacrylate, acryloxyethyl phosphate Acrylate monomers such as fluoroalkyl acrylate and sulfopropyl acrylate,
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, sec
-Butyl methacrylate, tert-butyl methacrylate, hexyl methacrylate, octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, lauryl methacrylate, stearyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-dimethylaminoethyl Methacrylate, 2-diethylaminoethyl methacrylate, 2-t
tert-butylaminoethyl methacrylate, glycidyl methacrylate, allyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, nonylphenyl methacrylate, benzyl methacrylate, dicyclopentenyl methacrylate, bornyl methacrylate, 1,4-butanediol dimethacrylate, 1,
3-butanediol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate,
Tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, dipropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, glycerol methacrylate, methacryloxyethyl phosphate, bismethacryloxy Examples thereof include methacrylate monomers such as ethyl phosphate.

When the ionizing radiation-curable resin is cured by irradiation with ultraviolet rays, an appropriate photopolymerization initiator (radical polymerization initiator) is added. Specifically, for example, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether or alkyl ethers thereof, acetophenone, acetophenone such as 2,2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexylphenyl ketone , Thioxanthones such as thioxanthone, 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone, ketals such as acetophenone dimethyl ketal and benzylmethyl ketal, benzophenones such as benzophenone and 4,4-bismethylaminobenzophenone, azo One or more selected from compounds and the like are used. If necessary, tertiary amines such as triethanolamine and methyldiethanolamine, 2-dimethylaminoethylbenzoic acid,
-One or more photosensitizers selected from benzoic acid derivatives such as ethyl dimethylaminobenzoate are used in combination.

The surface protective layer 3 may be provided, if necessary, with, for example, a coloring agent, a filler, an extender, a lubricant, a gloss adjusting agent, a lubricant, an antistatic agent, a plasticizer, a stabilizer, a flame retardant, Additives such as an antifoaming agent, an antioxidant, an antibacterial agent, and a fragrance can be appropriately added. In addition, it is composed of two or more layers having different gloss states on the surface, and by forming at least one layer in any desired pattern, a visual three-dimensional feeling and a sense of design due to a change in the gloss state of the surface can be obtained. You can also get.

If the thickness of the surface protective layer 3 is too small, sufficient surface properties cannot be obtained. If the thickness is too large, the flexibility of the entire sheet deteriorates, and the balance of the hardness with the thermoplastic resin layer 1 deteriorates. Therefore, it is preferable that the thickness be in the range of 1 to 10 μm. The method for forming the surface protective layer 3 is not particularly limited, and includes, for example, gravure coating, die coating, lip coating, knife coating, air knife coating, spray coating, flow coating, roll coating, and dip coating. For example, any conventionally known coating method can be used. Prior to the application of the ionizing radiation-curable resin, the surface of the thermoplastic resin layer 1 may be subjected to an appropriate surface such as corona treatment, ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, anchor or primer treatment, etc. By performing the treatment, the adhesion between the thermoplastic resin layer 1 and the surface protective layer 3 can be improved.

The ionizing radiation irradiating apparatus for curing the surface protective layer 3 is not particularly limited, and any one of conventionally known various ionizing radiation sources can be appropriately selected and used. Specifically, when ultraviolet rays are used, for example, various ultraviolet light sources such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, and a carbon arc lamp, and when an electron beam is used, for example, a Cockloft Walton type Various electron beam accelerators, such as, a handicap type, a resonance transformer type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used.

As described above, the decorative sheet of the present invention has a two-part thermosetting like a conventional decorative sheet by providing the surface protective layer 3 made of the ionizing radiation curable resin on the thermoplastic resin layer 1. By providing a top coat layer such as a urethane resin, it is possible to obtain surface properties such as extremely excellent surface hardness, abrasion resistance, abrasion resistance, and solvent resistance, which could not be achieved at all. I can do it.

By the way, depending on the selection of the type of the thermoplastic resin constituting the thermoplastic resin layer 1 and the ionizing radiation curable resin constituting the surface protective layer 3, it is not always possible to obtain satisfactory adhesion between them. There is also. In particular, when an olefin-based resin, a polyester-based resin, or the like is selected as the thermoplastic resin constituting the thermoplastic resin layer 1, a sufficient distance from the above-described general acrylic ionizing radiation-curable resin is sufficient. Ensuring good adhesion is generally somewhat difficult in many cases.

In order to cope with such a case, first, a compound having a functional group which adheres well to the thermoplastic resin forming the thermoplastic resin layer 1 is added to the ionizing radiation-curable resin forming the surface protective layer 3. There is a way to do that. In particular,
For example, in the case of a polyolefin-based resin, a resin containing a carboxyl group such as a maleic acid-modified resin, or a resin containing a carboxyl group, such as a maleic acid-modified resin, depends on the kind of the thermoplastic resin constituting the thermoplastic resin layer 1. When a compound having a group is added, the adhesiveness tends to be improved.

However, according to the above-mentioned method, although the adhesion to the thermoplastic resin layer 1 is improved, the above-mentioned various additives reduce the excellent internal cohesion due to the high crosslinking density of the ionizing radiation-curable resin. The surface physical properties of the surface protective layer 3, such as surface hardness, abrasion resistance, scratch resistance, and solvent resistance, tend to deteriorate. Therefore, as a method for improving the adhesion to the thermoplastic resin layer 1 without deteriorating the surface properties of the surface protective layer 3, the thermoplastic resin layer 1 and the surface protective layer 3 are used.
The intermediate layer 2 made of a composition exhibiting good adhesiveness to both the thermoplastic resin constituting the thermoplastic resin layer 1 and the ionizing radiation-curable resin constituting the surface protective layer 3 is provided between them. Methods can be mentioned.

As the intermediate layer 2, for example, an acrylic resin,
Adhesive resins such as urethane resins, polyester resins, ethylene-vinyl acetate copolymer resins, and vinyl chloride-vinyl acetate copolymer resins can also be used. Among them, various thermoplastic resins and ionizing radiation-curable resins can be used. It is preferable to use an acrylic resin or a urethane-based resin from the viewpoints of adhesiveness with the resin and weather resistance. More preferably, the intermediate layer 2 is preferably composed of a urethane-based resin composition containing an active hydrogen group and an isocyanate group, which is firmly formed inside the intermediate layer 2 by a reaction between the active hydrogen group and the isocyanate group. This is because strong cohesive force is formed, while strong adhesion is formed between the thermoplastic resin layer 1 and the isocyanate group. More preferably, in addition to the active hydrogen group and the isocyanate group, the intermediate layer 2 is preferably formed of a resin composition containing a polymerizable double bond. Since a cross-linking reaction is caused by the action of ionizing radiation and the polymerizable double bond contained in the ionizing radiation-curable resin constituting the layer 3, a strong adhesion is also formed between the resin and the surface protective layer 3. It is.

The active hydrogen group is a functional group containing a hydrogen atom capable of cross-linking with isocyanate, such as a hydroxyl group, a carboxyl group, or an amino group. Generally, a composition containing a hydroxyl group is used. Is done. Specifically, for example, compounds such as acrylic polyol, polyester polyol, and polyether polyol are used. As the compound containing an isocyanate group, for example, tolylene diisocyanate, mesitylene diisocyanate, hexamethylene diisocyanate and the like can be used, but in consideration of weather resistance, use of a non-aromatic isocyanate compound such as hexamethylene diisocyanate is preferable. Is preferred. In order to secure the adhesion to the thermoplastic resin layer 1, it is preferable that the isocyanate group is contained in excess of the amount theoretically required for the reaction with the active hydrogen group.

The isocyanate group has an action of forming good adhesion to various thermoplastic resins.
In particular, excellent adhesion can be obtained with respect to the polyolefin resin recommended as the thermoplastic resin layer 1 in the present invention. If the surface of the thermoplastic resin layer 1 made of a polyolefin resin or the like is previously subjected to a surface treatment such as a corona treatment, an ozone treatment, a plasma treatment, an ionizing radiation treatment, and a dichromic acid treatment, the adhesion is further improved. I do. This is because active hydrogen groups such as hydroxyl groups and carboxyl groups are formed on the surface of the thermoplastic resin layer 1 by the surface treatment, and a crosslinking reaction between these active hydrogen groups and the isocyanate groups contained in the intermediate layer 2. Is believed to be due to a strong chemical bond.

When the intermediate layer 2 made of the resin composition containing active hydrogen groups and isocyanate groups is provided as described above, before the reaction between the active hydrogen groups and the isocyanate groups is completed, It is preferable that the surface protective layer 3 made of an ionizing radiation curable resin is formed and cured by irradiation with ionizing radiation since the adhesion between the intermediate layer 2 and the surface protective layer 3 is further improved. Although the mechanism of this adhesion improvement is not necessarily clear, some of the radicals generated in the course of the radical polymerization reaction of the ionizing radiation-curable resin cause some form of crosslinking with isocyanate groups due to a chemical reaction. It is considered.

Examples of the compound containing a polymerizable double bond include acrylates such as polyester acrylate, urethane acrylate and epoxy acrylate, polyester methacrylate, urethane methacrylate, and the like.
Prepolymers or oligomers such as methacrylates such as epoxy methacrylate, and various acrylate or methacrylate monomers can be appropriately blended and used. When the surface protective layer 3 is cured by irradiation with ultraviolet light, the intermediate layer 2 may be
The same photopolymerization initiator and photosensitizer as those added to the surface protective layer 3 can be added.

When the intermediate layer 2 is composed of the resin composition containing a polymerizable double bond as described above, the polymerizable double bond contained in the intermediate layer 2 is not irradiated with ionizing radiation or the like. It is preferable to form the surface protective layer 3 made of an ionizing radiation-curable resin before being consumed by the crosslinking reaction by, and to cure by irradiation with ionizing radiation. Middle layer 2
After the polymerizable double bond contained therein is cross-linked and consumed, the cross-linking with the polymerizable double bond in the ionizing radiation-curable resin constituting the surface protective layer 3 is not performed, and This is because a good adhesion cannot be achieved.

The thickness of the intermediate layer 2 is not particularly limited, that is, the adhesiveness between the thermoplastic resin layer 1 and the surface protective layer 3 can be sufficiently ensured, and the flexibility and flexibility of the decorative sheet as a whole can be ensured. Any range that does not hinder the operation is acceptable. Generally, it is set in a range of about 1 to 10 μm.

The decorative sheet of the present invention may be provided with an emboss 6 on the surface of the thermoplastic resin layer 1 for the purpose of obtaining a change in surface gloss and a three-dimensional design. There is no particular limitation on the type of the pattern of the emboss 6, and for example, a wood grain shape, a wood grain conduit pattern shape, a stone grain shape, a cloth grain tone, a Japanese paper tone, an abstract pattern shape, a geometric pattern shape, a grain shape, a hairline shape, a parallel straight line The shape may be a group or a curve group, or a combination thereof. The emboss 6 may or may not be synchronized with the pattern of the pattern layer 4, and may be a combination of a pattern synchronized with the pattern of the pattern layer 4 and a pattern that is not synchronized. Further, the wiping 7 may be applied to the concave portion of the emboss 6.

In view of the fact that such decorative sheets are generally used by being attached to the surface of various base materials such as, for example, wood base materials, inorganic base materials, metal base materials, and synthetic resin base materials,
A primer layer 8 may be provided on the back surface of the decorative sheet for the purpose of improving the adhesiveness with an adhesive used for bonding to such a base material. There is no particular limitation on the type of the primer agent constituting the primer layer 8, and for example, an acrylic resin,
From various types of conventionally known primers mainly containing synthetic resins such as urethane resins, polyester resins, ethylene-vinyl acetate copolymer resins, and vinyl chloride-vinyl acetate copolymer resins as appropriate, depending on the application. Can be selected and used.

In the above description, the configuration in which the picture layer 4 is provided on the back surface of the thermoplastic resin layer 1 and the surface protection layer 3 made of ionizing radiation curable resin is provided on the front surface is considered. The decorative sheet is not limited to this. For example, as shown in FIG. 2, a pattern layer 4 and the like are provided on the surface of a thermoplastic resin layer 1 and a surface protective layer made of an ionizing radiation-curable resin is further provided thereon via an intermediate layer 2 if necessary. 3 may be provided.

In the case of this constitution, the thermoplastic resin layer 1 is not necessarily required to be transparent or translucent, and a opaque colored thermoplastic resin film or sheet to which a concealable pigment is added may be used. In that case, even if the concealing layer 5 is omitted, a sufficient concealing property can be secured. Further, the intermediate layer 2 is provided by using the above-mentioned resin composition constituting the intermediate layer 2 as the binder resin of the printing ink or the coating agent constituting the picture layer 4 and the concealing layer 5. Instead, the function can be combined with the picture layer 4 and the concealing layer 5.

In addition to the above-described single-layer type decorative sheet, a transparent or translucent thermoplastic resin layer 1 is provided on a base sheet 9 via a picture layer 4 as shown in FIG. Alternatively, a multi-layer decorative sheet having a structure in which a surface protective layer 3 made of an ionizing radiation-curable resin is provided on the surface thereof via an intermediate layer 2 as necessary. In the decorative sheet having such a configuration, the total thickness is usually designed to be in the range of about 50 to 300 μm, and the thickness of the base sheet 9 and the thickness of the thermoplastic resin layer 1 may be the same or different. Good but
Both are generally designed in the range of about 20 to 150 μm.

In the above-mentioned multi-layer type decorative sheet, the substrate sheet 9 is a film of any material as long as the material has strength, flexibility and flexibility suitable for a substrate sheet for a decorative sheet. Or a sheet-like body can be used,
For example, various kinds of thermoplastic resins similar to those mentioned as the thermoplastic resins constituting the thermoplastic resin layer 1 and others, for example, papers, woven fabrics, nonwoven fabrics, metal foils, and the like, or a plurality of composites selected therefrom Bodies, laminates and the like can be used. In general, it is preferable to use a film or a sheet made of a thermoplastic resin, and in particular, to use a film or a sheet made of a polyolefin-based resin, as described above for the thermoplastic resin layer 1. Most preferred for similar reasons.

In such a multi-layer type decorative sheet, the method of laminating the base sheet 9 and the thermoplastic resin layer 1 is not particularly limited. For example, the base sheet 9 previously formed into a film or a sheet is used. A pattern layer 4 on one or both of the resin layer 1 and the thermoplastic resin layer 1 and then laminating them by means such as a dry laminating method or a heat laminating method. A method of extruding and laminating a thermoplastic resin layer heated and melted on the surface of the picture layer, followed by cooling and solidification can be adopted. In addition, at the time of the lamination, an adhesive, an anchoring agent, a primer agent and the like may be interposed between the two if necessary.

When embossing 6 is applied to the surface of the thermoplastic resin layer 1, the embossing 6 may be applied before or after lamination with the base sheet 9, It is also possible to apply the same or different embosses 6 a plurality of times at a plurality of times selected from these.

In addition to the above, for example, a sheet body having three or more layers
It may be a multi-layer decorative sheet having a configuration in which the picture layer 4 and the like are sandwiched and laminated as necessary at one or more places between the layers, and in other words, of the plurality of sheet bodies constituting the decorative sheet The technology of the present invention can be applied as long as at least the outermost sheet body is made of a thermoplastic resin. In particular, the technique of the present invention can be favorably applied to a decorative sheet in which at least the outermost sheet is made of a polyolefin resin.

[0055]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples and comparative examples of the present invention.

Example 1 A 90 μm-thick polyolefin resin film (OW manufactured by Riken Vinyl Industry Co., Ltd.) was used as a base sheet, corona treatment was applied to both surfaces, and the surface was patterned with urethane gravure printing ink. Print the picture of
A urethane primer (Lamister manufactured by Toyo Ink Mfg. Co., Ltd.) was applied on the back surface at a coating amount of 1 g / m ² after drying to form a primer layer. On the printed surface of the printed base sheet, a two-component urethane-based dry laminating adhesive (Seikabond manufactured by Dainichi Seika Kogyo Co., Ltd., coated amount after drying 3 g / m ² ) is used as a thermoplastic resin layer to form a thickness. A 90 μm transparent olefin-based resin film (OW manufactured by Riken Vinyl Industry Co., Ltd.) was pasted and embossed as a conduit pattern. After filling the concave portion of the emboss with a coloring agent by a wiping method, a two-liquid urethane-based primer agent containing a polyol compound and an isocyanate compound (primer X manufactured by Dainichi Seika Co., Ltd.)
Is applied to a film thickness of 1 μm after drying to form an intermediate layer, and after touch drying, an ultraviolet-curable resin paint (TI-X manufactured by Dainichi Seika)
Is applied to a thickness of 5 μm, and a high-pressure mercury lamp (120 W × 2 lamps,
(5 m / min) to cure by irradiating ultraviolet rays to form a surface protective layer, thereby producing a decorative sheet of the present invention. When the surface hardness of this decorative sheet was measured, it was pencil hardness HB. Further, it was confirmed that gloss change did not occur at a heat resistance test of 130 ° C.

<Comparative Example 1> In Example 1, two liquids were used instead of the intermediate layer composed of a two-part urethane primer containing a polyol compound and an isocyanate compound and the surface protective layer composed of a UV-curable resin paint. A decorative sheet having a surface protective layer formed by applying a urethane-based top coat agent (UR251 manufactured by Toyo Ink Mfg. Co., Ltd.) to a thickness of 6 μm after drying was prepared, and the surface hardness was measured. The pencil hardness was 2B. The limit temperature at which no gloss change occurred in the heat resistance test was 120 ° C.

<Example 2> In Example 1, an intermediate layer was formed from a resin composition obtained by further adding a urethane acrylate oligomer to a two-pack urethane-based primer containing a polyol compound and an isocyanate compound. A decorative sheet was produced under the same conditions as in Example 1.
This decorative sheet has the same surface hardness and heat resistance as those of the decorative sheet of Example 1, but the bending of the surface protective layer under more severe conditions as compared with the decorative sheet of Example 1 is performed. It was confirmed that peeling did not occur and that the adhesion between the thermoplastic resin layer and the surface protective layer was excellent.

[0059]

As described in detail above, the decorative sheet of the present invention has a structure in which a surface protective layer made of an ionizing radiation-curable resin is provided on a thermoplastic resin layer. Compared with a decorative sheet having a surface protection layer of a system, it is a decorative sheet having excellent surface physical properties such as surface hardness, abrasion resistance, scratch resistance, and solvent resistance, and also having high heat resistance.
When used in applications where conventional decorative sheets can be used, not only can durability be significantly improved, but also severe surface physical properties that cannot be applied with conventional decorative sheets are required. It has an excellent effect that it can sufficiently withstand applications such as boards, floorboards, and stair steps.

Particularly, a resin composition containing an acrylic resin or a urethane resin, more preferably an active hydrogen group and an isocyanate group, between the thermoplastic resin layer and the ionizing radiation curable resin layer, More preferably, by providing an intermediate layer comprising a resin composition containing a polymerizable double bond, the adhesion between the thermoplastic resin layer and the surface protective layer is increased, and the abrasion resistance and the resistance of the decorative sheet are improved. In addition to improving the abrasion resistance and durability, it also has an excellent effect of being able to withstand severe secondary processing and to obtain a decorative sheet that can be used for a wide range of applications.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a decorative sheet of the present invention.

FIG. 2 is a side sectional view showing an embodiment of the decorative sheet of the present invention.

FIG. 3 is a side sectional view showing an embodiment of the decorative sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermoplastic resin layer 2 Intermediate layer 3 Surface protective layer made of ionizing radiation curable resin 4 Picture layer 5 Concealment layer 6 Emboss 7 Wiping 8 Primer layer 9 Base sheet

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2E110 AB05 AB22 AB23 BA02 BA03 BA04 BA05 BA11 BB02 GA03X GA03Z GA05W GA32W GA32X GA32Z GB43X GB43Z GB44X GB44Z GB45X GB45Z GB46X GB46Z GB47X GB47Z GB52X GB52Z 4F100 AK01A02 AK01A02C BA03 BA04 BA05 BA07 BA10A BA10B CA13 GB08 GB81 HB00 HB01 HB21 HB31 JB14B JB16A JK13 JK14 JK17

Claims (5)

[Claims] 1. A decorative sheet comprising a thermoplastic resin layer and a surface protective layer made of an ionizing radiation-curable resin. 2. The decorative sheet according to claim 1, further comprising an intermediate layer made of an acrylic resin or a urethane resin between the thermoplastic resin layer and the surface protective layer. 3. The decorative sheet according to claim 2, wherein the intermediate layer is formed from a resin composition containing an active hydrogen group and an isocyanate group. 4. The decorative sheet according to claim 3, wherein the intermediate layer is further formed from a resin composition containing a polymerizable double bond. 5. The method according to claim 1, wherein said thermoplastic resin layer is composed of a polyolefin resin.
The decorative sheet according to any one of the above.