JPH11217920A - Decorative sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet capable of maintaining global environment with weatherability and a moldability required as a decorative sheet and spontaneously extinguishing after disposal by applying decorative treatment on a plate material made of a polylactic acid-based resin. SOLUTION: This decorative sheet is a single layer structured plate material 1, made of polylactic acid-based resin produced from starch, and necessary decorative treatment (ink picture pattern layer 2) required as the decorative sheet is applied. It is favourable to have poly-L-lactic acid as a main component of the poly-lactic acid-bane resin. Poly-L-lactic acid-based resin is used as a hard segment and a substance of combination of it with a soft segment of caprolactone, etc., to play a role of a modifier to impart plasticity is used in case when maldability is to be imparted to polylactic acid resin. These resins are mixed with a colorant such as dye, pigment, etc., various additives such as an ultraviolet ray absorbent, a light stabilizer, a mildewproofing medium, a flame retardant, etc., and a biodegradable filler such as paper dust, wood dust, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative board used for various decorations including interior materials.

[0002]

2. Description of the Related Art Heretofore, as one of this type of decorative board, a board using a plate material made of a polyvinyl chloride resin has been used. This polyvinyl chloride board is suitable for printing,
Excellent embossing and excellent moldability.
There is an advantage that it is cheaper. However, this type of decorative board has a drawback that heat resistance is insufficient or that the surface has poor stain resistance due to bleeding of the plasticizer. Therefore, recently, as a substitute for polyvinyl chloride resin, styrene, olefin, urethane,
Polyamide-based, ester-based thermoplastic elastomers, EVA (ethylene vinyl alcohol copolymer), PET
(Polyethylene terephthalate) or various decorative boards made of acrylic resin have been proposed.

[0003]

However, there is a problem in that decorative panels made of any of the above-mentioned materials are permanently left as garbage when discarded, which is undesirable from the viewpoint of protecting the natural environment. .

[0004] The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a veneer plate having the necessary weather resistance and proper molding processing, and furthermore, dispose of it and leave it as it is. Another object of the present invention is to provide a new decorative board that disappears naturally.

[0005]

Means for Solving the Problems To achieve the above object, the decorative plate of the present invention is made of a plate made of polylactic acid resin, and is characterized by being subjected to a decorative treatment.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A decorative board according to the present invention is a board 1 having a single-layer structure as shown in FIG. 1, and this board 1 is made of a polylactic acid-based resin. (Ink pattern layer 2).

The polylactic acid-based resin is produced from starch, and the polylactic acid-based resin used in the present invention is preferably a resin mainly composed of poly-L-lactic acid. In addition, when it is necessary to further impart molding processability to the polylactic acid-based resin, a poly-L-lactic acid-based resin may be used as a hard segment, and a hard segment combined with a soft segment may be used. Those plasticized by combining soft segments are suitable for forming applications such as bending and drawing. The soft segment serves as a modifier for imparting plasticity, and the soft segment used in the present invention includes caprolactone, and among them, ε-caprolactone is preferable.

[0008] As a combination of these hard segments and soft segments, there are two forms of a mixture and a copolymer. That is, the mixture is a mixture of lactic acid (polylactic acid-based resin) that has become a homopolymer and caprolactone (polycaprolactone) that has become a homopolymer. Further, the copolymer is an unpolymerized lactic acid (hereinafter, also referred to as “lactic acid monomer”) or a prepolymer thereof, and an unpolymerized caprolactone, etc. (hereinafter, also referred to as “caprolactone monomer, etc.”). ) To) or those obtained by copolymerizing the prepolymer. The soft segment may be mixed or copolymerized with a pure polylactic acid-based resin to reduce its hardness (that is, lowering Young's modulus, elastic limit, softening temperature, etc., elongation at break, impact resistance) Can be increased), but any of those usually preferably used is a caprolactone monomer,
It is a prepolymer or a polymer (polycaprolactone). Hereinafter, these will be mainly described as examples.

When poly-L-lactic acid and poly (ε-caprolactone) are used in producing a resin obtained by mixing a polylactic acid-based resin and a polymer to be a soft segment, the weight of poly-L-lactic acid is increased. Those having an average molecular weight of 100,000 or more, preferably 200,000 or more are used, and those of poly (ε-caprolactone) having a weight average molecular weight of 1 to 100,000 are used. The mixing ratio of the two is such that the polylactic acid-based resin / the polymer to be the soft segment = 1/9 to 9/1 (polymerization ratio).

In producing a copolymer of a lactic acid monomer or a prepolymer thereof and a monomer to be a soft segment or a prepolymer thereof, when L-lactic acid monomer and ε-caprolactone are used, A monomer or prepolymer is used as lactic acid, and ε-caprolactone also uses the monomer or prepolymer. The copolymerization ratio of both is lactic acid monomer or prepolymer / soft segment monomer or prepolymer = 1/9 to 9/1 (input polymerization ratio). The molecular weight of the copolymer is 100,000 or more, preferably 200,000 or more.

If necessary, various additives such as coloring agents such as dyes and pigments, ultraviolet absorbers, light stabilizers, fungicides, and flame retardants are added to these resins. Further, a biodegradable filler such as paper powder or wood powder may be mixed.

The ultraviolet absorber and the light stabilizer are both added to impart weather resistance (light) to the decorative plate, and either one of them may be used alone, but usually both are used in combination. As the ultraviolet absorber, an organic type such as benzotriazole type, benzophenone type or salicylate type, or an inorganic type such as fine particle titanium dioxide or cerium oxide is used. As the light stabilizer, a hindered amine radical scavenger or the like is used. Both the ultraviolet absorber and the light stabilizer are added in an amount of about 0.1 to 1% by weight.

As a method for forming the above resin into a plate material, an extrusion molding method, an injection molding method and the like can be mentioned. In this case, the plate material may be a cellular foam by adding a foaming agent to the resin and molding the resin. As the foaming agent, a pyrolytic foaming agent such as azodicarbonamide is used. The thickness of the plate to be manufactured is 1
It is about 20 mm. In addition, if necessary, a uniaxial or biaxial stretching of a stretching ratio of about 2 to 4 times may be applied to the resin plate.
The heat treatment may be performed at a temperature of about 80 to 120 ° C.

The board is subjected to a desired decorative treatment. Examples of the decoration processing include coloring by kneading a pigment or a dye, forming a decorative layer composed of a pattern of an ink picture layer and a metal layer, and forming an uneven pattern. The decorative layer or the concavo-convex pattern may be formed on the front surface, the back surface, or both the front and back surfaces when the plate material is transparent, but must be formed on the front surface side when the decorative plate is opaque. FIG. 1 illustrates a case where the ink picture layer 2 is applied to the back surface of a transparent polylactic acid-based resin as an example of the decoration process.

When the plate is colored by kneading a pigment or dye, it is transparently colored or opaque (concealing property) depending on the application.
Colored. Pigments include titanium white, zinc white, ultramarine,
Inorganic pigments such as cobalt blue, red iron oxide, vermilion, graphite, titanium yellow, carbon black, etc .; Metal pigments composed of dyes, foil powders of aluminum, brass and the like, pearlescent pigments composed of titanium dioxide-coated mica, foil powders of basic lead carbonate and the like are used. In addition, if necessary, calcium carbonate,
An extender pigment (filler) such as silica (silicon dioxide), alumina (aluminum oxide), and barium sulfate is added.

In order to form a pattern with the ink picture layer,
Normal printing methods such as gravure offset printing and silk screen printing can be used, but drawing may be used. The picture layer is formed by forming an ink composed of a resin binder and a pigment or a dye into an arbitrary pattern. Also,
An ink layer on a releasable support sheet, and a transfer sheet on which an adhesive layer is further formed as necessary are prepared in advance, and the ink layer formed on the transfer sheet is pressurized, or by pressurization and heating. It is also possible to use a so-called transfer printing method in which the pattern is transferred to a surface on which a pattern layer (ink pattern layer) is to be formed. Examples of patterns include wood grain, stone grain, cloth grain, leather crest, characters, figures, and solid solids. As a resin binder of the ink, a two-component curable urethane resin, an acrylic resin, a cellulose resin, a vinyl chloride-vinyl acetate copolymer, or the like is used. The same pigments or dyes as described above are used. Prior to the formation of the ink pattern layer, an easy adhesion treatment such as a corona discharge treatment may be applied to the surface of the plate material.

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

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

The embossing is performed by pressing a heated and softened surface of a plate material with an embossing plate using a hot press type sheet-fed embossing machine, and shaping the unevenness on the surface of the embossed plate. This is a method of forming a pattern. Examples of the concavo-convex pattern formed by the embossing include those expressing wood grain conduit grooves, wood grain wood texture, stone surface unevenness, fabric surface texture, satin finish, grain, hairline, and the like, or a combination thereof.

If necessary, the concave portions of the concavo-convex pattern are filled with coloring ink by a known wiping process. As this coloring ink, a urethane resin, an acrylic resin, a polyester resin, and a pigment or dye added to a conventional vehicle are selectively used.
Those having good solvent resistance are preferred. Wiping may be performed by any of conventionally used wiping methods such as a doctor blade method and a roll coating method.
According to these methods, the colored ink is applied to the entire surface of the concave and convex pattern, and then the ink of the convex portion is scraped off to leave the colored ink in the concave portion.

Examples of uses of the decorative board of the present invention include:
Interior materials of buildings such as walls, floors, ceilings, window frames, door frames, doors, fittings such as handrails, furniture such as chests, cabinets for home appliances such as television receivers and OA equipment. it can.

[0022]

EXAMPLES Example 1 Poly-Polymer having a Weight Average Molecular Weight of 200,000
0.5 part by weight of a benzotriazole-based UV absorber is added to 100 parts by weight of a resin obtained by mixing 70% by weight of an L-lactic acid-based resin and 30% by weight of poly (ε-caprolactone) having a weight average molecular weight of 30,000. And 0.5 parts by weight of a hindered amine radical scavenger and a total of 5 parts by weight of a pigment consisting of titanium white, red stalks and graphite were prepared. 5mm in width, 100m in width
The m-baseboard-shaped plate material was manufactured.

Next, the transfer sheet was pressed against the surface of the plate material obtained above with a heating roller to transfer a wood grain pattern to perform a decoration treatment. The transfer sheet used was prepared by using an ink obtained by adding a mixture of vinyl chloride-vinyl acetate copolymer and an acrylic resin in a ratio of 2 to 8 by weight as a binder and a red stalk as a pigment on a biaxially stretched PET support sheet. The grain pattern is printed by gravure printing, and an adhesive layer of polyvinyl chloride is formed thereon.

Example 2 ε- during ring-opening polymerization of lactide
Caprolactone is copolymerized and the copolymerization ratio is L-lactic acid /
A copolymer having ε-caprolactone = 70/30 (input weight ratio) was produced. The weight average molecular weight of the copolymer was 200,000. A decorative board was produced in the same manner as in Example except that this resin was used instead of the mixed resin of poly-L-lactic acid-based resin and poly (ε-caprolactone).

(Evaluation) Weather resistance: 1 with a carbon arc lamp type sunshine weatherometer
An exposure test of irradiating for 000 hours was performed. The conditions were a black panel temperature of 63 ° C. and a rain cycle of 18 minutes / 120 minutes. When the decorative plates obtained in Examples 1 and 2 were visually observed for discoloration and discoloration after exposure, no remarkable change was observed in the appearance. Degradability Each decorative board obtained in Examples 1 and 2 was buried in the soil of Miyoshi-cho, Iruma-gun, Saitama, and excavated after leaving it for 6 months from April to September. Then, when the appearance was visually observed, decomposition was progressing, and the plate material was not in the original shape and was in a fragmented shape. In addition, the molecular weight retention of the recovered decorative plate fragment was measured for reference and was 40%.

[0026]

As described above, the decorative board of the present invention has the necessary weather resistance and suitability for forming as a decorative board, and is used in the interior of building materials. It is not biodegraded by water or bacteria and is completely decomposed into water and carbon dioxide by the action of microorganisms in the soil when it is disposed of and left in contact with the soil or left in the soil. It is preferable for

[Brief description of the drawings]

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

[Explanation of symbols]

 1 board material 2 ink picture layer

Claims (1)

[Claims] 1. A plate made of a polylactic acid-based resin,
A decorative plate, which has been subjected to a decoration process.