JP5245437B2 - Cosmetic sheet and cosmetic material - Google Patents

Description

  The present invention relates to a decorative sheet and a decorative material for use in interior and exterior materials of buildings such as houses, building materials such as construction materials and fittings, surface makeup such as residential equipment and home appliances, More specifically, the present invention relates to a cosmetic sheet and a cosmetic material that are made of a plant-derived plastic polylactic acid resin as a base sheet material, do not generate toxic gas even when incinerated, and are friendly to the global environment and the human body.

  As such a resin-based decorative sheet, a decorative sheet having a single-layer configuration in which a pattern is printed on the front surface side or the back surface side of the thermoplastic resin sheet substrate, and a thermoplastic resin sheet substrate on the back surface side of the pattern layer. There is a decorative sheet having a multilayer structure sandwiched between the transparent resin layer on the surface side. The former has the advantage that it can be manufactured easily and inexpensively because of its simple structure, while the latter is somewhat disadvantageous in terms of manufacturing and price, but the pattern is protected from both the front and back sides, so the wear resistance of the pattern and Combines surface properties such as solvent resistance and weather resistance, and resistance to the adhesive used when bonding to the substrate to be adhered, and also from the design side, high concealment by coloring the base sheet and transparent resin There are many advantages in terms of performance, such as achieving high design by embossing the layer. Due to this relationship, both are properly used according to the performance and price required by the application.

  Conventionally, as a thermoplastic resin used for this type of decorative sheet, vinyl chloride resin, polyolefin resin, acrylic copolymer resin, etc. are used as a base sheet of the decorative sheet or a transparent resin layer on the surface of the base sheet. Has been. In particular, decorative sheets using vinyl chloride resin have been widely used because of their excellent printability, high design, and adhesion to the base material, but due to environmental problems such as gas generated during incineration. A decorative sheet made of polyolefin resin has been developed and proposed (see Patent Document 1).

Polylactic acid is attracting attention as a biomass material that can be mass-produced from corn and other biomass raw materials. Due to the recent increase in interest in environmental issues, the production plant has been upgraded to reduce costs to conventional petroleum-derived plastics. Is expected as an alternative. Polylactic acid has a relatively high melting point of about 170 ° C, and has advantages such as transparency and high elastic modulus, but heat resistance and hydrolysis due to softening in environments above the glass transition temperature. It is a material that has both disadvantages such as deterioration of physical properties and solvent resistance.

In order to reduce the environmental load, polylactic acid has been studied as a decorative sheet material, but due to the above problems, it is difficult to examine polylactic acid alone. For example, Patent Document 2 discloses a decorative sheet obtained by applying a decoration treatment to a resin base sheet made of a polylactic acid-based resin. When these prescriptions are used, the decorative sheet is in close contact with ink for pattern printing. Satisfying various weather resistance such as moisture resistance, heat resistance, etc. required for decorative sheets, impact resistance due to brittle properties, adhesion with primer layer for improving adhesion to base materials such as woody materials, etc. I can't.

As a technique for modifying polymer materials, alloy modification with other polymer materials is widely used, and for polylactic acid, alloys with acrylic resins, polycarbonate resins, and polyester resins have been studied. Yes. In modification by polymer alloy, a combination with good compatibility is effective as much as possible, but from this point, polylactic acid and polyolefin resin are poorly compatible, so-called incompatible combination, simply polylactic acid and polyolefin It is not possible to expect a large reforming effect by blending. For example, Patent Document 3 discloses a study of blending an olefin with polylactic acid, but even if these formulations are used, performance as a decorative sheet cannot be obtained.

Regarding the use of biomass materials, the Japan Bioplastics Association (JBPA) contains more than a specified amount of organic resources (plants, etc.) derived from organic resources as a constituent component of plastics. Biomass plastic products are used to prevent global warming and reduce fossil resource consumption. In view of the importance of biomass, we established a biomass plastic identification and labeling system, and certified products that meet the standards established by this association as “biomass plastic” so that general consumers can easily identify biomass plastic products. The use of the mark is permitted. In order to identify and identify biomass plastics, it is necessary that the plastic level of the biomass plastic in the product is 25.0 wt% or more, and the biomass material ratio in the decorative sheet is as high as possible (at least 25.0 wt% or more). This is very important even considering the burden on the global environment. Considering that it will be recognized as an added value by consumers by obtaining the biomass plastic certification mark, is there.
JP 2001-353828 A JP-A-11-129426 JP 9-316310 A

  The present invention has been made to solve the above-described problems in the prior art, and the problem is to develop a decorative sheet using a polylactic acid-based resin in order to reduce the environmental load. It is an object of the present invention to provide a decorative sheet that increases the biomass ratio of the decorative sheet and provides the same level of performance as that of a conventional petroleum-based plastic decorative sheet.

The invention according to claim 1 is a decorative sheet in which at least a pattern ink layer, a transparent thermoplastic resin layer, and a surface protective layer are laminated in this order on a thermoplastic resin sheet substrate. Is a decorative sheet composed of at least a polylactic acid-based resin and a polyolefin-based resin, wherein the polylactic acid-based resin is a dispersed phase and the polyolefin-based resin is a continuous phase, and the polylactic acid-based resin is at a temperature of 190 ° C. relation between elongational viscosity eta ₄ and extensional viscosity eta ₃ at a temperature 190 ° C. of the polyolefin resin, the elongation strain rate 10 sec ^-1, and satisfies a relation of η ₃ / η ₄ = 2.56 It is a decorative sheet.

In the invention according to claim ₂ , the relationship between the shear viscosity η ₁ of the polylactic acid resin at a temperature of 190 ° C. and the shear viscosity η ₂ of the polyolefin resin at a temperature of 190 ° C. is a shear strain rate of 10 to 1000 seconds. The decorative sheet according to claim 1, wherein a relationship of 100> η ₁ / η ₂ > 1 is satisfied in a range of ⁻¹ .

The invention of claim 3 is the decorative sheet according to claim 1 or 2, wherein the polyolefin resin comprises a polypropylene resin.

The invention according to claim 4, wherein the transparent thermoplastic resin layer, of claims 1 to 3, characterized in that it comprises a polyolefin resin of the thermoplastic resin sheet a polyolefin-based resin and the lines constituting the substrate The decorative sheet according to any one of the above.

The invention according to claim 5 is the decorative sheet according to any one of claims 1 to 4, wherein the surface protective layer contains an ultraviolet absorber and a light stabilizer.

The invention described in claim 6 is a decorative material characterized in that the decorative sheet according to any one of claims 1 to 5 is bonded to a wooden substrate.

The invention according to claim 1 is a decorative sheet in which at least a pattern ink layer, a transparent thermoplastic resin layer, and a surface protective layer are laminated in this order on a thermoplastic resin sheet substrate. Is a decorative sheet characterized in that it is composed of at least a polylactic acid resin and a polyolefin resin, and has a phase structure in which the polylactic acid resin is a dispersed phase and the polyolefin resin is a continuous phase. The thermoplastic resin sheet base material is composed of at least a polylactic acid resin and a polyolefin resin, and has a phase structure in which the polylactic acid resin is a dispersed phase and the polyolefin resin is a continuous phase. It is possible to obtain a decorative sheet with sufficient physical properties that does not cause problems such as heat resistance, solvent resistance, and moisture resistance, which are disadvantages of polylactic acid.

In the present invention, the thermoplastic resin sheet base material has a so-called sea-island structure in which the polylactic acid-based resin is a dispersed phase and the polyolefin-based resin is a continuous phase. When the thermoplastic resin sheet substrate is composed of a single polylactic acid resin, the necessary physical properties as a decorative sheet cannot be obtained due to the problems of polylactic acid described above. Also, when considering polymer alloy with polyolefin resin, for example, the phase structure of polylactic acid resin in continuous phase and polyolefin resin in dispersed phase improves problems such as adhesion to ink and moisture resistance. Can not do it.

In the invention according to claim ₂ , the relationship between the shear viscosity η ₁ of the polylactic acid resin at a temperature of 190 ° C. and the shear viscosity η ₂ of the polyolefin resin at a temperature of 190 ° C. is a shear strain rate of 10 to 1000 seconds. The decorative sheet according to claim 1, wherein a relationship of 100> η ₁ / η ₂ > 1 is satisfied in a range of ⁻¹ . When the shear viscosity ratio between the polylactic acid resin and the polyolefin resin at 190 ° C. is within this range, a phase structure in which the polylactic acid resin is a dispersed phase and the polyolefin resin is a continuous phase can be obtained. When η ₁ / η ₂ is 1 or less, the polyolefin resin has a phase structure of a dispersed phase and the polylactic acid resin has a continuous phase, and when η ₁ / η ₂ is 100 or more, the polylactic acid system The dispersibility of the resin is poor, the dispersed phase size of the polylactic acid resin is increased, the film forming property of the thermoplastic resin sheet is deteriorated, and it is difficult to obtain a uniform film.

Further, the relation between elongational viscosity eta ₃ at a temperature 190 ° C. of the polylactic acid-based resin and extensional viscosity eta ₄ at a temperature 190 ° C. of the polyolefin resin, the elongation strain rate 10 sec ^-1, η ₃ / η ₄ = It is a decorative sheet characterized by satisfying the relationship of 2.56 . When the elongational viscosity ratio between the polylactic acid resin and the polyolefin resin at 190 ° C. is outside this range, a uniform film applicable to a decorative sheet cannot be obtained.

The invention of claim 3 is the decorative sheet according to any one of claims 1 to 2, wherein the polyolefin resin comprises a polypropylene resin. When the polyolefin resin used for the thermoplastic resin sheet base material contains a polyolefin resin, appropriate flexibility, abrasion resistance, scratch resistance, heat resistance, chemical resistance, post-processability, etc. required for decorative sheets, etc. Can be granted.

The invention according to claim 4, wherein the transparent thermoplastic resin layer, of claims 1 to 3, characterized in that it comprises a polyolefin resin of the thermoplastic resin sheet a polyolefin-based resin and the lines constituting the substrate The decorative sheet according to any one of the above. When the transparent thermoplastic resin layer is made of a polyolefin resin, it is possible to obtain a decorative sheet having excellent adhesion to the thermoplastic resin sheet substrate and various weather resistances.

The invention according to claim 5 is the decorative sheet according to any one of claims 1 to 4, wherein the surface protective layer contains an ultraviolet absorber and a light stabilizer. Deterioration of the decorative sheet due to the influence of ultraviolet rays or the like over a long period of time under ultraviolet irradiation can be suppressed, and the change with time of the adhesion of the surface protective layer can be suppressed. This makes it possible to provide a decorative sheet having excellent weather resistance.

The invention described in claim 6 is a decorative material characterized in that the decorative sheet according to any one of claims 1 to 5 is bonded to a wooden substrate. By using the decorative sheet of the present invention, the biomass ratio as a decorative material is also high.

The present invention is described in detail below.
FIG. 1 is a schematic cross-sectional view showing an example of the laminated structure of the decorative sheet of the present invention. In the example shown in FIG. 1, the decorative sheet of the present invention has a sea-island structure in which the thermoplastic resin sheet substrate 1 is composed of a polylactic acid resin and a polyolefin resin, and the polylactic acid resin is a dispersed phase and the polyolefin resin is a continuous phase. have. The pattern ink layer 2, the transparent thermoplastic resin layer 5, and the surface protective layer 6 are sequentially laminated on the thermoplastic resin sheet substrate.

  The polylactic acid-based resin is a polymer containing L-lactic acid and / or D-lactic acid as a main constituent component, but may contain a copolymer component other than lactic acid. Other copolymer components include glycol compounds such as ethylene glycol and propylene glycol, dicarboxylic acids such as oxalic acid and terephthalic acid, hydroxycarboxylic acids such as glycolic acid and hydroxybenzoic acid, and lactones such as caprolactone and propiolactone. Can be mentioned.

  Examples of polyolefin resins include polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene. -Ethyl acrylate copolymer, those obtained by acid modification for the purpose of improving adhesiveness, or ionomer can be selected as appropriate, and may be a single type or a mixture of plural types. Among them, homopolypropylene, random polypropylene, and the like, which are provided with reasonable flexibility, abrasion resistance, scratch resistance, heat resistance, chemical resistance, post-processability, etc. required as a decorative sheet, and at low cost. Polypropylene resins such as block polypropylene and propylene-α-olefin copolymers are most suitable.

In the present invention, when a polypropylene resin is used for the thermoplastic resin sheet substrate, an unsaturated carboxylic acid such as maleic acid or its anhydride is graft-copolymerized or terminal-modified as a compatibilizing agent for improving dispersibility. It is desirable to add an acid-modified modified polyolefin resin such as a modified polyolefin resin.

  The blending ratio of the polylactic acid resin and the polyolefin resin (including the modified polyolefin resin component) constituting the thermoplastic resin sheet substrate is 150 parts by weight of the polyolefin resin with respect to 100 parts by weight of the polylactic acid resin. Hereinafter, the range is preferably 50 parts by weight. When the proportion of the polyolefin resin is small, the phase structure that is the feature of the present invention cannot be formed, so the effect of modifying the defects such as heat resistance and solvent resistance of the polylactic acid resin cannot be obtained. In addition, when the ratio of the polyolefin resin is large, the biomass ratio of the decorative sheet becomes low and the object of the present invention cannot be achieved.

In the present invention, it is necessary to have a sea-island structure in which a polylactic acid-based resin is a dispersed phase and a polyolefin-based resin is a continuous phase in a thermoplastic resin sheet substrate. For this purpose, the melt viscosity characteristics of the polylactic acid resin and the polyolefin resin are important. Specifically, the relationship between the shear viscosity η ₁ of the polylactic acid resin at the measurement temperature of 190 ° C. and the shear viscosity η ₂ of the polyolefin resin is 100> η in the range of the shear strain rate of 10 to 1000 seconds− ^1. It is necessary to satisfy the relationship ₁ / η ₂ > 1. When the biomass ratio of the decorative sheet is increased, that is, when the blending ratio of the polylactic acid resin is larger, the polylactic acid resin tends to be a continuous phase and the polyolefin resin tends to be a dispersed phase as the phase structure. By selecting a resin having such a viscosity characteristic, it becomes possible to use a polylactic acid resin as a dispersed phase. By using a polylactic acid resin as a dispersed phase, a thermoplastic resin sheet base material having improved solvent resistance, heat resistance, hydrolysis resistance, and the like, which are disadvantages of the polylactic acid resin, can be obtained.

In addition, regarding the elongational viscosity of the polylactic acid-based resin and the polyolefin-based resin, the following range is important from the viewpoint of take-up properties during film formation. Specifically, the relationship between the elongation viscosity η ₃ of the polylactic acid resin at 190 ° C. and the elongation viscosity η ₄ of the polyolefin resin is 100> η ₃ / η in the range of the elongation strain rate of 1 to 100 seconds− ^1. It is necessary to satisfy the relationship of ₄ > 1. Elongation viscosity greatly affects the film-forming property in the molding of thermoplastic resin sheet base material. If the elongation viscosity ratio of the polylactic acid resin and polyolefin resin is outside the range of the present invention, it is non-uniform during film formation. As a result, it is difficult to obtain a uniform sheet, and the film forming speed cannot be increased, resulting in poor productivity.

The shear viscosity and elongational viscosity in the present invention are measured by the following methods.
Measuring device: Twin capillary rheometer “RH-7D” manufactured by Rosand
Long die: φ1mm, capillary length 16mm
Orifice die: φ1mm, capillary length 0.25mm
The twin capillary rheometer has a pair of barrels and a piston. A general capillary die (long die) is attached to one barrel, and an orifice die having a capillary length of almost zero is attached to the other barrel. Resin for measurement is put into each barrel and capillary, resin melted at a predetermined temperature is extruded from the capillary die at a controlled piston speed, and the pressure at that time is measured.
Since the shear strain rate is calculated from the piston speed and the shear stress can be calculated from the measurement pressure, the shear stress and the shear viscosity for each shear strain rate can be obtained by measurement with the piston speed changed.
Further, by assuming that the capillary length of the orifice die is zero and measuring the pressure loss P ₀ at the orifice die, the elongation viscosity and the elongation strain rate can be calculated by the following equations.

The polylactic acid resin used in the present invention can be subjected to a hydrolysis resistance treatment by end-blocking the polylactic acid resin within a range that does not impair the object of the present invention. By performing the hydrolysis resistance treatment, it becomes possible to improve the moisture resistance as a decorative sheet. The end-capping agent is not particularly limited as long as it is a compound capable of capping the carboxyl end group of polylactic acid, and it is possible to use what is used as a carboxyl end-capping agent for general polymers. it can.

Examples of such a carboxyl group-reactive endblocker include glycidyl ether compounds, glycidyl ester compounds, glycidyl amine compounds, glycidyl imide compounds, alicyclic epoxy compounds, and other epoxy compounds, N, N′-di-2,6- Carbodiimide compounds such as diisopropylphenylcarbodiimide, 2,6,2 ′, 6′-tetraisopropyldiphenylcarbodiimide, polycarbodiimide, 2,2′-m-phenylenebis (2-oxazoline), 2,2′-p-phenylenebis At least one compound selected from oxazoline compounds such as (2-oxazoline) and oxazine compounds, or two or more compounds can be arbitrarily selected and used.

For the thermoplastic resin sheet base, depending on the intended use of the decorative sheet, for example, an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a plasticizer, a lubricant, an antistatic agent, a flame retardant, One or more conventionally known various additives such as fillers may be added. Specifically, the additives shown below can be used as these additives.

Examples of antioxidants include phenols, sulfurs, phosphoruss, etc., ultraviolet absorbers such as benzophenones, benzotriazoles, salicylates, cyanoacrylates, formamidines, oxanilides, etc. Hindered amines, nickel complexes, etc., heat stabilizers such as hindered phenols, sulfurs, hydrazines, etc., plasticizers depending on the type of resin, but phthalates, phosphates, fatty acids, etc. Type, aliphatic dibasic acid ester type, oxybenzoic acid ester type, epoxy type, polyester type, etc., as the lubricant, for example, fatty acid ester type, fatty acid type, metal soap type, fatty acid amide type, higher alcohol type, paraffin type, etc. Antistatic agents include, for example, cationic, anionic, and nonio Examples of flame retardants such as bromine, phosphorus, chlorine, nitrogen, aluminum, antimony, magnesium, boron, and zirconium, and fillers such as calcium carbonate, talc, It can be used in one or a mixture of two or more selected from wax, kaolin and the like.

In addition to the above, the thermoplastic resin sheet substrate 1 may be colored by appropriately adding a colorant such as an organic or inorganic dye or pigment to the thermoplastic resin constituting the thermoplastic resin sheet substrate 1. it can. In particular, when the decorative sheet needs to be concealed depending on the application, it is preferable to use the concealing pigment to make the thermoplastic resin sheet substrate 1 concealable. The concealable pigment is a pigment having a high refractive index as compared with the thermoplastic resin as a dispersion medium. From the aspect of high refractive index, weather resistance, chemical resistance, etc., for example, a titanium oxide pigment or an iron oxide pigment is used. It is preferable to use at least an inorganic pigment such as a pigment. Of course, instead of making the thermoplastic resin sheet substrate 1 itself concealable, a concealing solid layer made of a printing ink or a coating agent containing a concealing pigment or the like may be provided, or both may be used in combination. .

There is no restriction | limiting in particular in the manufacturing method of the thermoplastic resin sheet base material 1, It can form into a film by well-known methods, such as a T-die extrusion method, an inflation molding method, and a calendar molding method. Moreover, there is no restriction | limiting in particular in the thickness of the thermoplastic resin sheet base material 1, The thing of the same thickness as the base material sheet of the 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 generally selected from a range of about 50 to 200 μm.

Further, the thermoplastic resin sheet base material is provided with a primer layer 8 as necessary on the surface to be bonded to a base material such as a wood base material. As the primer layer 8, for example, a urethane resin, an acrylic resin, an ethylene-vinyl acetate resin, a polyester resin, or the like may be arbitrarily selected from conventionally known easy-adhesive primer agents. Moreover, adding an inorganic fine powder such as silica to the primer layer 8 to roughen it is effective for preventing blocking during winding and storing of the decorative sheet and improving adhesiveness due to the anchoring effect.

The pattern ink layer 2 is provided for the purpose of imparting the desired decorative design of the desired decorative sheet to the target decorative sheet, and the type of the pattern is not particularly limited. For example, the grain pattern or the stone pattern Various patterns similar to those in the case of a conventional decorative sheet, such as an abstract pattern and a plain solid color, can be employed. There are no particular limitations on the constituent material and the formation method of the pattern ink layer 2, and for example, a colorant such as an organic or inorganic dye or pigment is dissolved or dispersed in an appropriate solvent together with an appropriate binder resin. The printing ink or the coating agent can be provided by printing or coating by an appropriate printing method or coating method.

Examples of the colorant include inorganic pigments such as carbon black, titanium white, zinc white, dial, bitumen, cadmium red, azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, dioxazine pigments, and the like. Metallic pigments such as organic pigments, gold powder, silver powder, copper powder, aluminum powder, bronze powder, pearl luster pigments such as fish scale powder, basic lead carbonate, bismuth oxide oxide, titanium oxide-coated mica, fluorescent pigments, nocturnal pigments, etc. Alternatively, a mixture of two or more selected from these can be used.

Examples of the binder resin include acrylic resins, styrene resins, polyester resins, urethane resins, polyvinyl resins, alkyd resins, petroleum resins, ketone resins, epoxy resins, and melamine resins. , Various synthetic resins such as fluorine-based resins, silicone-based resins, fiber derivatives, and rubber-based resins, or a mixture or copolymer of two or more thereof can be used.

Examples of the solvent include petroleum organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, methylcyclohexane, ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyacetate. Ester-based organic solvents such as ethyl, alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, propylene glycol, and ketone-based organics such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone Solvents, ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; salts such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene It can be used various organic solvents such systems an organic solvent, an inorganic solvent such as water, or two or more mixed solvents thereof.

There is no particular limitation on the method for forming the pattern ink layer 2, and various conventionally known printing methods such as gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing are used. can do. In addition, for example, in the case of a solid surface, in addition to the above-described various printing methods, for example, roll coating method, knife coating method, air knife coating method, die coating method, lip coating method, comma coating method, kiss coating method, flow coating method Various coating methods such as a dip coating method can also be used. In addition, for example, a hand-drawn method, ink-sink method, photographic method, laser beam or electron beam drawing method, partial vapor deposition method or etching method of metal or the like, or a combination of these methods can of course be performed.

“Transparent” of the transparent thermoplastic resin layer 5 laminated on the thermoplastic resin sheet substrate / pattern ink layer is not necessarily limited to transparency in the strict sense, but is translucent or colored. It may be transparent. As the resin material, known thermoplastic resins such as polyolefin resins such as polyethylene, polypropylene, polyolefin thermoplastic elastomer, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol can be used. A polyolefin resin can be suitably used.

Examples of polyolefin resins include polyethylene, polypropylene, polybutene, polyisoprene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene. -Ethyl acrylate copolymer, those obtained by acid modification for the purpose of improving adhesiveness, or ionomer can be selected as appropriate, and may be a single type or a mixture of plural types. Among them, homopolypropylene, random polypropylene, from the point of being provided with moderate flexibility, abrasion resistance, scratch resistance, heat resistance, chemical resistance, post-processability, etc. required as a decorative sheet, and at low cost. Polypropylene resins such as block polypropylene and propylene-α-olefin copolymers are most suitable. In addition, by using a resin of the same type as the polyolefin resin used for the thermoplastic resin sheet base material, the adhesion of the laminate and the sheet behavior under the weather resistance test environment are similar, which causes problems such as delamination of the decorative sheet. Can be prevented.

There is no restriction | limiting in particular in the thickness of the transparent thermoplastic resin layer 5, It can set equivalent to the case of the conventional common decorative sheet. Specifically, when it is used as a transparent resin layer of a decorative sheet having a multilayer structure as shown in FIG. 1, it is often in the range of about 20 to 150 μm.

In the decorative sheet having a multilayer structure as shown in FIG. 1, the pattern ink layer 2 is provided on the side of the transparent thermoplastic resin layer 5 before the thermoplastic resin sheet base material 1 and the transparent thermoplastic resin layer 5 are laminated. However, it may be provided on the thermoplastic resin sheet substrate 1 side. Further, prior to the formation of the pattern ink layer 2, for example, corona treatment, ozone treatment, plasma treatment, ionizing radiation treatment, heavy chromium is applied to the printing surface of the transparent thermoplastic resin layer 5 or the thermoplastic resin sheet substrate 1. By performing surface treatment such as acid treatment, anchor treatment or primer treatment, the adhesion between the transparent thermoplastic resin layer 5 or the thermoplastic resin sheet substrate 1 and the pattern ink layer 2 can be improved. In addition, the thermoplastic resin sheet base material in the present invention is characterized in that the polyolefin resin has a phase structure of a continuous phase, and this structure makes it difficult to use a polylactic acid resin alone. It is possible to obtain ink adhesion equivalent to that of a conventional decorative sheet.

In the present invention, the method for laminating the transparent thermoplastic resin layer 5 and the thermoplastic resin sheet substrate 1 is not particularly limited, and any conventionally known method can be appropriately applied. Specifically, for example, an appropriate adhesive 5 such as a dry laminate adhesive, a heat-sensitive adhesive, a pressure-sensitive adhesive, or an ionizing radiation curable adhesive is used for the transparent thermoplastic resin layer 5 previously formed into a film shape or a sheet shape. A method of adhering to the surface of the thermoplastic resin sheet substrate 1 via a film, a method of directly adhering by means of thermocompression bonding or ultrasonic welding without using an adhesive, or a film obtained by heating and melting a transparent thermoplastic resin From a variety of conventionally known methods, such as a method of extruding into a sheet and simultaneously laminating and adhering to the surface of the thermoplastic resin sheet substrate 1, a method that matches the characteristics of the resin is appropriately selected and used. be able to.

In addition, of course, the pattern ink layer 2 may be applied to the transparent thermoplastic resin layer 5 and / or the thermoplastic resin sheet base material 1 prior to the above-described lamination. As an example, an appropriate surface activation treatment such as corona treatment or ozone treatment or an anchor made of an appropriate adhesive resin composition is applied to the adhesive surface of the transparent thermoplastic resin layer 5 and / or the thermoplastic resin sheet substrate 1. You can also keep it. In the case of the extrusion laminating method, the adhesiveness can be improved by coextrusion lamination so that the adhesive resin 4 is sandwiched between the thermoplastic resin sheet substrate 1 and the transparent thermoplastic resin. .

The surface of the transparent thermoplastic resin layer 5 may be provided with an emboss 7 having an appropriate pattern as required as conventionally known. There is no particular limitation on the type of embossed 7 pattern, and it may be various patterns such as, for example, wood grain (especially a conduit pattern), stone texture, Japanese paper, fabric texture, geometric pattern, or the like. For example, it may be a simple matte shape, a grain shape, a hairline shape, a suede tone or the like. Further, the design can be further improved by synchronizing the pattern of the emboss 7 with the pattern of the pattern ink layer 2, but if it is not necessary, the pattern may be non-synchronized. It is also possible to provide an emboss 7 having a pattern including both a pattern synchronized with the two patterns and a pattern not synchronized.

A method for forming the embossing 7 is not particularly limited, but a mechanical embossing method using a metal embossing plate is the most common. Further, there is no particular limitation on the formation time of the emboss 7, and any time can be selected from before, simultaneously with, or after the lamination with the thermoplastic resin sheet base material 1. The emboss 7 having the same or different pattern can be applied a plurality of times at a plurality of times. In addition, the concave portion of the emboss 7 may be filled with a colorant by a method such as a wiping method as necessary, thereby creating a decorative sheet having a color design synchronized with the uneven pattern on the surface and having excellent design. Can be obtained.

Moreover, the surface protective layer 6 can also be provided on the surface of the transparent thermoplastic resin layer 5 for the purpose of imparting more excellent surface properties to the surface of the decorative sheet. The surface protective layer 6 first has a role of protecting the surface, and is a layer for improving surface hardness maintenance, improving stain resistance, and adjusting surface gloss. The material used can be appropriately selected from polyurethane, acrylic silicon, fluorine, epoxy, vinyl, polyester, melamine, aminoalkyd, urea, and the like. Any of aqueous, emulsion, and solvent systems can be used, and curing can be either a one-component type or a two-component type using a curing agent. Among these, a urethane-based protective layer using isocyanate is desirable from the viewpoints of workability, cost, cohesion of the resin itself, and the like.

  The isocyanates described above include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), metadiisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), methylhexane diisocyanate (HTDI). ), Methylcyclohexanone diisocyanate (HXDI), trimethylhexamethylene diisocyanate (TMDI), etc., but considering weather resistance, a type having a linear structure rather than a type having a double bond, particularly hexamethylene diisocyanate ( HMDI) is optimal.

Further, the surface protective layer 6 in the present invention has a role of improving the weather resistance, and it is necessary to appropriately add an ultraviolet absorber and a light stabilizer. A triazine-based ultraviolet absorber can be suitably used as the ultraviolet absorber, and a hindered amine-based light stabilizer can be suitably used as the light stabilizer.

Examples of the triazine-based ultraviolet absorber used for the protective layer 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, 2,4-bis ( 2,4-dimethylphenyl) -6- (2-hydroxy-4-iso-octyloxyphenyl) -s-triazine and the like, mixtures, modified products, polymers and derivatives thereof can be exemplified, and these can be used alone. It can be used as a mixture in a plurality.

The hindered amine light stabilizer used in the protective layer is bis (1,2,2,6,6-pentamethyl-4-piperidinyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxy. Phenyl] methyl] butyl malonate, bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, decane Examples thereof include acid bis [2,2,6,6-tetramethyl-1-octyloxy) -4-piperidinyl] ester, mixtures thereof, modified products, polymers, derivatives, etc., and these may be used alone or in combination. Can be used as a mixture.

Since the surface protective layer is present on the outermost surface, the portion contributing to the weather resistance of the sheet is large. Therefore, it is necessary to sufficiently consider the weather resistance, and the amount added depends on the solubility in the resin and the solvent, and also considers the required physical properties and harmful effects due to the addition of a large amount, respectively, 100 parts by weight of the solid content of the protective layer coating liquid. In contrast, about 0.1 to 10 parts by weight is added.

The coating liquid may be appropriately selected in consideration of solvent, solventless, water-based, emulsion-based, hot-melt, etc., drying properties and heat resistance of the sheet, blocking properties after drying, adhesion to the sheet, and the like. . Also, the coating method is, for example, gravure coating method, roll coating method, dip coating method, air knife coating method, knife coating method, comma coating method, die coating method, lip coating method, kiss coating method, rod coating method, spray coating method, Any conventionally known coating method such as a flow coating method can be appropriately applied. Moreover, it is preferable that it is 1-20 micrometers as a film thickness of a surface protective layer.

In addition, when the adhesiveness between the transparent thermoplastic resin layer 5 and the surface protective layer 6 is insufficient, for example, corona treatment is performed on the surface of the transparent thermoplastic resin layer 5 prior to the formation of the surface protective layer 6. By performing surface treatment such as ozone treatment, plasma treatment, ionizing radiation treatment, dichromic acid treatment, anchor or primer treatment, the adhesion between the transparent thermoplastic resin layer 5 and the surface protective layer 6 can be improved. it can.

Examples of the present invention will be specifically described below. The present invention is not limited to these examples.

As a thermoplastic resin sheet base material, a polylactic acid resin (manufactured by Unitika; TE4000), a polypropylene resin (manufactured by prime polymer; Y-2045GP), a mylein-modified polypropylene resin (manufactured by Sanyo Kasei; Umex 1001) is weight ratio 50: 47: 3. In the twin-screw extruder, 0.2% by weight of a phenolic antioxidant, 0.3% by weight of a hindered amine light stabilizer and 0.2% by weight of an antiblocking agent are added to the thermoplastic resin material blended in Was melt kneaded at a molding temperature of 190 ° C. and a screw speed of 200 rpm. A sheet was extruded from a T die attached to the tip of the extruder to form a base sheet having a width of 900 mm and a thickness of 60 μm. Shear viscosity ratio at a shear strain rate of 100 sec ^-1 of the obtained thermoplastic resin sheet base material 3.24, elongation viscosity ratio of elongation strain rate 10 sec ^-1 was 2.56.
The surface of the obtained base material sheet 1 is subjected to corona treatment, and then subjected to a wood grain pattern using a pattern ink (manufactured by Toyo Ink Manufacturing Co., Ltd .; Lamister) by a gravure printing method to form a pattern printing layer 2. . Further, a two-component curable urethane anchor coating agent [manufactured by Toyo Ink Mfg. Co., Ltd .; EL510 (polyester polyol) as a main agent; 50% by weight; manufactured by Mitsui Takeda Chemical Co., Ltd .; A520 ( Urethane modified polyester polyol) is used in a mixture of 50% by weight. In addition, a mixture of 5% by weight of 4,4-diphenylmethane diisocyanate, 50% by weight of isophorone diisocyanate and 45% by weight of hexamethylene diisocyanate is used as the isocyanate, and the above-mentioned main agent and isocyanate are mixed in a ratio of 5: 1 to give two liquids. A curable urethane anchor coating agent was used. ] Was applied by a gravure printing method to form an anchor coat layer 3.

Homopolypropylene resin with 0.2% by weight of phenolic antioxidant, 0.3% by weight of hindered amine light stabilizer, 0.5% by weight of benzotriazole UV absorber, 0.2% by weight of antiblocking agent The added transparent polypropylene resin layer 5 constituent resin and the modified random polypropylene resin graft-polymerized with maleic anhydride (the carbonyl group content in 1 g of the modified random polypropylene is 0.02 mmol equivalent) are co-extruded from the T-die. At the same time, by laminating and embossing at the same time by passing between a cooling roll and a pressure roll, which are integrated with the base sheet 1 and subjected to conduit embossing, the pattern printing layer 2 is applied. The surface of the anchor coat layer 3 on the base sheet 1 was embossed with a concave pattern on the surface via the adhesive resin layer 4. The Akiranetsu thermoplastic resin layer 5 was laminated. Immediately before the lamination with the base sheet 1, ozone gas was blown onto the adhesive resin layer 4, which functions as the adhesive resin layer, by an ozone treatment device to further improve the laminate strength.

Further, as a surface protective layer on the transparent thermoplastic resin side, a triazine-based 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 (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 topcoat by gravure coating so that the thickness after drying and curing is 9 μm. Created a sheet.

The obtained decorative sheet was bonded to an MDF plate having a thickness of 3 mm with an acrylic emulsion adhesive to make a state of a decorative board, and evaluation described later was performed.

As a thermoplastic resin sheet base material, a polylactic acid resin (manufactured by Unitika; TE4000), a polypropylene resin (manufactured by prime polymer; Y-2045GP), and a mylein-modified polypropylene resin (manufactured by Sanyo Kasei; Umex 1001) are in a weight ratio of 60: 38: 2. In the twin-screw extruder, 0.2% by weight of a phenolic antioxidant, 0.3% by weight of a hindered amine light stabilizer and 0.2% by weight of an antiblocking agent are added to the thermoplastic resin material blended in Was melt kneaded at a molding temperature of 190 ° C. and a screw speed of 200 rpm. A sheet was extruded from a T-die attached to the tip of the extruder, a base sheet having a width of 900 mm and a thickness of 60 μm was formed, and the same decorative sheet as in Example 1 was prepared for other materials and manufacturing methods. Shear viscosity ratio at a shear strain rate of 100 sec ^-1 of the obtained thermoplastic resin sheet base material 3.24, elongation viscosity ratio of elongation strain rate 10 sec ^-1 was 2.56.

<Comparative Example 1>
A biaxially stretched polylactic acid film (manufactured by Mitsubishi Chemical Corp .; Ecologue) was used as the thermoplastic resin sheet substrate, and the same decorative sheet as in Example 1 was prepared for other materials and production methods.

<Comparative example 2>
As a thermoplastic resin sheet base material, a polylactic acid resin (manufactured by Unitika; TE4000), a polypropylene resin (manufactured by prime polymer; E-200GV), and a mylein-modified polypropylene resin (manufactured by Sanyo Kasei; Umex 1001) are weight ratio of 50: 47: 3. In the twin-screw extruder, 0.2% by weight of a phenolic antioxidant, 0.3% by weight of a hindered amine light stabilizer and 0.2% by weight of an antiblocking agent are added to the thermoplastic resin material blended in Was melt kneaded at a molding temperature of 190 ° C. and a screw speed of 200 rpm. A sheet was extruded from a T-die attached to the tip of the extruder, a base sheet having a width of 900 mm and a thickness of 60 μm was formed, and the same decorative sheet as in Example 1 was prepared for other materials and manufacturing methods. Shear viscosity ratio at a shear strain rate of 100 sec ^-1 of the obtained thermoplastic resin sheet base material 0.61, elongation viscosity ratio of elongation strain rate 10 sec ^-1 was 0.75.

The evaluation results for the following items are shown in Table 1.

(Substrate sheet phase observation)
An ultrathin section was cut out using a microtome, and the state of the continuous phase and the dispersed phase in the cross section of the base material sheet was observed by TEM observation. The case where the phase constitution in which the polylactic acid resin is a dispersed phase and the polyolefin resin is a continuous phase, which is a feature of the present invention, can be confirmed; X.

(Weather resistance evaluation)
The resulting decorative sheet was subjected to a weathering acceleration test (metal halide lamp type testing machine JTM G 01 2000 Japan Testing Machine Industry Association Standard) in order to evaluate the weather resistance. As a tester, a die plastic metal weather (KU-R5CI-A: manufactured by Daipura Wintes Co., Ltd.) was used.

The weathering accelerated test conditions are
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) Light (irradiation) (53 ° C., 50% RH) 20.00 hours 2 . Dew (dark condensation) (30 ° C., 98% RH) 4.00 hours Rest (rest) (30 ° C, 98% RH) 0.01 hours
The above 24.01 hours was defined as one cycle, and the test was performed for 216 hours. The shower was performed for 30 seconds before and after Dew. The appearance and laminate strength of the decorative sheet after the test were measured and evaluated.

The obtained decorative sheet was held in a constant temperature and humidity layer at 60 ° C. and 90% RH for 500 hours, and then the appearance and laminate strength of the decorative sheet were measured and evaluated as a moisture resistance and heat resistance test.

  As can be seen from the results in Table 1, Examples 1 and 2 obtained by the present invention have a phase structure in which the polylactic acid resin, which is a feature of the present invention, is a dispersed phase and the polyolefin resin is a continuous phase. Accordingly, it was possible to obtain a decorative sheet excellent in weather resistance, heat resistance, and moisture resistance as compared with a decorative sheet composed of a film of a polylactic acid resin alone as shown in Comparative Example 1. In Comparative Example 2, since the viscosity ratio of the polylactic acid resin and the polyolefin resin is outside the scope of the claims of the present invention, the phase structure in which the polyolefin resin is a dispersed phase and the polylactic acid resin is a continuous phase. Accordingly, the necessary physical properties as a decorative sheet are not obtained. From the above results, in developing a decorative sheet using a polylactic acid-based resin for reducing the environmental load according to the present invention, the biomass ratio of the decorative sheet is increased and the same level as that of a conventional petroleum-based plastic decorative sheet. It was possible to provide a decorative sheet imparted with the above performance.

It is a schematic cross section of an example of the decorative sheet of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermoplastic resin sheet base material 2 Picture ink layer 3 Anchor coat layer 4 Adhesive resin layer 5 Transparent thermoplastic resin layer 6 Surface protective layer 7 Emboss 8 Primer layer

Claims (6)

In a decorative sheet in which at least a pattern ink layer, a transparent thermoplastic resin layer, and a surface protective layer are laminated in this order on a thermoplastic resin sheet substrate, the thermoplastic resin sheet substrate is at least a polylactic acid resin and a polyolefin resin. A decorative sheet comprising a resin and having a phase structure in which a polylactic acid-based resin is a dispersed phase and a polyolefin-based resin is a continuous phase, the elongation viscosity η _{3 of the} polylactic acid-based resin at a temperature of 190 ° C. and the polyolefin-based resin The decorative sheet is characterized in that the relationship with the elongation viscosity η _{4 at} a temperature of 190 ° C. satisfies the relationship η ₃ / η ₄ = 2.56 at an elongation strain rate of 10 seconds ⁻¹ . Wherein a shear viscosity eta ₁ at a temperature 190 ° C. of the polylactic acid-based resin, the relationship between the shear viscosity eta ₂ at a temperature 190 ° C. of the polyolefin resin, in the range of shear strain rate from 10 to 1000 sec ^-1, 100> eta The decorative sheet according to claim 1, wherein a relationship of ₁ / η ₂ > 1 is satisfied. Decorative sheet according to claim 1 or 2, wherein the polyolefin resin comprises a polypropylene resin. The decorative sheet according to any one of claims 1 to 3 , wherein the transparent thermoplastic resin layer includes a polyolefin resin of the same type as that of the polyolefin resin constituting the thermoplastic resin sheet base material. The decorative sheet according to any one of claims 1 to 4 , wherein the surface protective layer contains an ultraviolet absorber and a light stabilizer. A cosmetic material comprising at least the decorative sheet according to any one of claims 1 to 5 bonded to a wooden substrate.