JP2007190928A - Manufacturing method of embossed decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive embossed decorative sheet which is made of a material other than a vinyl chloride resin, has sufficient flexibility for excellent resin workability, shows excellent embossing reproducibility, does not cause a problem of separation of a base material even after a durability test, and can provide a product of excellent design. <P>SOLUTION: Disclosed is a manufacturing method of an olefin-based resin embossed decorative sheet which comprises a process of extruding at least a molten olefin-based resin through a T-die between an embossed cooling roll and a pressing roll to obtain the embossed sheet, a process of conducting a corona treatment on the surface of the embossed sheet to stencil color ink in an embossed recess, and a process of mounting a top coat layer, wherein the embossed sheet is a 70 to 120 μm thick mono-embossed layer and has a colored picture obtained by kneading wooden powder or one or more highly concentrated resin pellets for coloring. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an embossed decorative sheet, and more particularly to an embossed decorative sheet that is used as a decorative plate by being bonded to the surface of a wood board, inorganic board, metal plate or the like with an adhesive.

Conventionally, a vinyl chloride resin sheet has been used as a decorative sheet used in the above-mentioned applications, and a colored vinyl chloride sheet having a thickness of 70 to 120 μm and a transparent chloride having a thickness of 70 to 120 μm, which is provided with an arbitrary pattern. Lamination and embossing were performed simultaneously by passing the vinyl sheet between hot-pressed rolls with embossing. However, it is said that vinyl chloride resin generates hydrogen chloride gas during incineration, causing acid rain and dioxins. In recent years, decorative sheets that do not use vinyl chloride resin are being demanded from the viewpoint of environmental problems.
Furthermore, since the laminating method and the embossing method are performed by hot pressure, the applied embossing can reproduce only about 70% of the original embossed plate, and there is a problem in the design.

  Therefore, the inventors previously extrude an olefin-based transparent molten resin onto an embossed cooling roll as a method for producing a decorative sheet having excellent emboss reproducibility without using a vinyl chloride resin, and applying a pattern. A method of pasting with the colored substrate was proposed (see Patent Document 1).

However, in this method, whether the method of laminating the transparent resin layer and the colored substrate with a pattern is either dry lamination or extrusion lamination, it has a functional group that is essentially necessary to adhere to other materials on the structure. The initial adhesion strength can be obtained by providing a surface treatment, an anchor coat layer and an adhesive resin layer, but the adhesion strength after the durability test such as weather resistance and heat resistance test is reduced. There was a drawback that it was greatly reduced. Furthermore, since it is a bonded sheet of a transparent resin layer and a colored substrate with a pattern, the sheet thickness is about 140 to 240 μm, and V-cut processing after bonding with a wooden substrate, at the time of processing at a low temperature It also had the disadvantage that whitening was observed.
Japanese Patent Laid-Open No. 9-24585

The present invention has been made in order to solve the above-mentioned problems, and the problem is that the material has a property that exceeds the characteristics of a vinyl chloride resin sheet using a material other than the conventional vinyl chloride resin. An embossed decorative sheet manufacturing method is provided. Specifically, by making the base material of the decorative sheet into a single layer structure using an olefin resin, the decorative sheet has flexibility excellent in processability, excellent embossing reproducibility, and after the durability test. It is an object of the present invention to provide a method for producing an inexpensive embossed decorative sheet excellent in design without causing a problem of material peeling.

  In order to solve the above-mentioned problem, the invention according to claim 1 is the step of obtaining an embossed sheet by extruding at least a molten olefin resin from a T-die between an embossed cooling roll and a pressure roll, In the method for producing an olefin-based resin embossed decorative sheet, comprising a step of corona-treating the surface of the sheet and imprinting colored ink into the embossed recess, and further providing a topcoat layer, the embossed sheet is a single layer having a thickness of 70 to 120 μm Production of an olefin-based resin embossed decorative sheet characterized by being an embossed sheet and an embossed sheet having a colored pattern obtained by kneading wood powder or one or more high-density resin pellets for coloring Is the method.

  According to a second aspect of the present invention, the coloring pattern is pre-dispersed by melting and kneading wood powder or one or more high-concentration pigments into a resin that is not completely melt-mixed with the extruded resin. The olefin-based resin composition according to claim 1, wherein the high-concentration resin pellet for coloring is a colored pattern with a random pattern in a state where the high-concentration resin pellet for coloring is not completely mixed in the extruded resin. It is a manufacturing method of a resin embossed decorative sheet.

  The invention according to claim 1 is a step of obtaining an embossed sheet by extruding at least a molten olefin-based resin from a T-die between an embossed cooling roll and a pressure roll, and subjecting the surface of the embossed sheet to corona treatment. In the method for producing an olefin-based resin embossed decorative sheet having a step of printing colored ink on the embossed recess and a step of providing a topcoat layer, the embossed sheet is a single-layer embossed sheet having a thickness of 70 to 120 μm, and wood A method for producing an olefin-based resin embossed decorative sheet, which is an embossed sheet having a colored pattern obtained by kneading powder or one or more high-density resin pellets for coloring. The production method of the present invention makes it possible to obtain an embossed decorative sheet with excellent emboss reproducibility. Further, since the embossed sheet has a single-layer structure, there is no problem of peeling, and furthermore, since the sheet thickness is thin, whitening does not occur in V-cut processing at a low temperature.

  According to a second aspect of the present invention, the coloring pattern is pre-dispersed by melting and kneading wood powder or one or more high-concentration pigments into a resin that is not completely melt-mixed with the extruded resin. The olefin-based resin composition according to claim 1, wherein the high-concentration resin pellet for coloring is a colored pattern with a random pattern in a state where the high-concentration resin pellet for coloring is not completely mixed in the extruded resin. It is a manufacturing method of a resin embossed decorative sheet. Since the pattern is replaced with a random pattern in a state where wood powder in the resin or high-concentration resin pellets for coloring are not completely mixed, the manufacturing process is simplified and the manufacturing method of the embossed decorative sheet is inexpensive. It becomes possible to provide.

  The present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a cross-sectional view of a conventional embossed decorative sheet. For example, a transparent resin layer (3) formed by extrusion of an olefin resin and a colored sheet (1) with an arbitrary pattern formed in a separate process are bonded together by dry lamination or extrusion lamination at the same time as embossing. Yes, in order to improve the adhesion between the transparent resin layer (3) and the colored sheet (1), an anchor coat layer or an adhesive resin layer (2) is provided on the colored sheet surface, and the transparent resin layer (3) The embossed decorative sheet has a structure in which the embossed concave portion (4) is filled with colored ink (5) later and a topcoat protective layer (6) is provided on the outermost surface.

  On the other hand, as shown in FIG. 2, the embossed decorative sheet of the present invention extrude olefin resin kneaded with wood flour or one or more high-density resin pellets for coloring, and was cooled and solidified simultaneously with embossing. A colored substrate (1) with a single-layer embossed pattern is then surface-treated by corona treatment, etc., and then the colored ink (3) is imprinted in the embossed recess (4) to further protect the top coat. It is an embossed decorative sheet provided with a layer (6). The embossed decorative sheet of the present invention is a single-layered embossed decorative sheet, unlike the conventional embossed decorative sheet comprising a two-layer structure of a transparent resin layer and a colored sheet.

  As the olefin resin used in the present invention, in particular, a polypropylene homopolymer, a random polymerization polymer, a block polymerization polymer, or any one of a low density polyethylene, an α olefin, an ethylene-propylene copolymer rubber as a soft component, or a mixture of 5 to 5. Although 30% by weight of a resin simply mixed and added can be used, it is not necessarily limited.

  The polymer type of the polypropylene is a homopolymer when the obtained sheet requires heat resistance, hardness, etc., a block polymer when the impact resistance is required, and impact resistance, low temperature workability, and transparency. When required, a random polymer may be selected as appropriate. However, since the low-temperature processability is emphasized, it can be said that the random polymerization type polypropylene is optimal.

  If the amount of the soft component added is 5% by weight or less, there is no effect on low-temperature processability, and if it is 30% by weight or more, the elasticity of the obtained sheet is too large. The soft component to be added is simply mixed, but this not only simplifies the process, but when both are crosslinked, the transparency is impaired, or the interface of the soft component having a domain structure by crosslinking in polypropylene This is because there is an inconvenience such as causing a whitening phenomenon due to an impact received by the slab.

  Further, an antioxidant, a light stabilizer, and an ultraviolet absorber are appropriately added in order to prevent thermal oxidation deterioration of the obtained sheet, light, particularly ultraviolet light deterioration. The types and amounts of these additives are not particularly specified and may be those generally used for olefins, but due to their effects, phenols are used as antioxidants and hindered amines are used as light stabilizers. Benzotriazole type is desirable for the ultraviolet absorber.

  Olefin resins are colored because they need to be concealed. As a coloring method, a dry color method using a fine powdery colorant obtained by treating a pigment with a dispersion aid or a surfactant, and preparing a master batch pellet in which a resin and a high concentration pigment are melt-kneaded and predispersed. However, there is a masterbatch method in which dry blending is performed with a normal resin that is not colored in the extrusion hopper, but it is not particularly limited. The pigments may be those usually used for polyolefins, but inorganic pigments such as titanium oxide, ultramarine blue, cadmium pigment, iron oxide and the like are particularly desirable in consideration of heat resistance and weather resistance. Also, organic pigments such as phthalocyanine pigments and quinacridone pigments can be used. The ratio and color of the pigment are appropriately determined in consideration of the degree of concealment and design, and are not particularly limited. However, as a method of applying a pattern to the resin, in the present invention, high-density resin pellets for coloring in the extruded resin Can be substituted with a random pattern in a state where the high-density resin pellets for coloring in the extruded resin are not completely mixed, the process is simplified and the cost is extremely low An inexpensive embossed decorative sheet is obtained.

  Next, an example of the manufacturing method of the embossed decorative sheet of this invention is demonstrated with the schematic diagram shown in FIG. An embossed cooling roll (embossing roll) (7) and a pressure roll (8) are extruded with a molten olefin resin kneaded with wood powder or one or more high-density resin pellets for coloring. The embossed base material moves along the outer periphery of the embossing roll and is subjected to surface treatment by a corona treatment machine (not shown) on the surface of the embossed sheet peeled off by the peeling roll (9). Do. Thereafter, the wiping coloring ink (5) is imprinted in the embossed recess (4) by a wiping and topcoat machine (not shown), and a topcoat protective layer (6) is further provided to obtain an embossed decorative sheet.

  Surface treatment by the above corona treatment machine is necessary to activate the surface because the olefin resin itself, which is the base material of the embossed sheet, does not have a functional group that contributes to adhesion. The treatment degree is sufficient if it is 38 dyn / cm or more.

  The ink and topcoat agent are not particularly defined as long as they are for olefinic sheets, but the inventors have found that urethane inks and topcoat agents are optimal. It is also possible to add a matting agent such as silica to the topcoat agent depending on the required luster and change the luster arbitrarily.

  By imprinting colored ink on the embossed recesses of the embossed sheet and further providing a topcoat layer, it is possible to improve the design and surface properties.

  As described above, by using an olefin resin as a resin to be melt-extruded as in the present invention, the generation of toxic gas that becomes a problem when using a vinyl chloride resin is solved. At the same time, the sheet is solidified by the embossed cooling roll, so that a sheet having excellent embossing reproducibility can be obtained. In addition, the embossed decorative sheet of the present invention is a thick sheet having a thickness of about 140 to 240 μm in a conventional two-layer configuration by bonding a colored base sheet with a pattern and a transparent resin layer. Due to the thickness of about 70 to 120 μm of the single layer configuration, it is not whitened even in the bending process in a low temperature environment, and because of the single layer configuration, heat, moisture, An embossed decorative sheet having no problem of peeling such as a decrease in adhesion strength between the colored base material sheet provided with a pattern by light or the like and the transparent resin layer was obtained. Furthermore, since the pattern is replaced with a random pattern in a state where the high-density resin pellets for coloring in the extruded resin are not completely mixed, an inexpensive embossed decorative sheet that simplifies the process and is very advantageous in terms of cost. can get.

  Below, the example of the manufacturing method of the embossing decorative sheet of this invention is demonstrated.

<Reference Example 1>
Random polymerization type polypropylene hydrogenated styrene and butadiene rubber as thermoplastic elastomer 15% by weight, phenolic antioxidant 0.2% by weight, hindered amine light stabilizer 0.3% by weight, benzotriazole A resin added with 0.5% by weight of an ultraviolet absorber was extruded from a T-die between a cooling roll and a pressure roll provided with conduit embossing to obtain an embossed sheet having a thickness of 100 μm. Thereafter, the sheet surface was subjected to corona treatment, and the surface was adjusted to 40 dyn / cm. An embossed decorative sheet was obtained by imprinting urethane-based wiping ink on the embossed recess of this embossed sheet, and further applying about 2 μm of urethane-based topcoat resin on the surface by the gravure method.

<Comparative Example 1>
As a base sheet, a colored sheet obtained by adding 6% by weight of an inorganic pigment to the resin composition of Reference Example 1 is prepared, and after corona treatment is performed on the surface, wood grain printing is performed using a urethane-based pattern ink by a gravure method. gave. After applying about 1 μm of urethane-based anchor coating agent on the printed sheet by the gravure method, the resin used in Reference Example 1 is extruded from a T-die onto the pattern-coated sheet coated with the anchor coating agent, Embossing was given by a cooling roll with embossing. An ink embossed decorative sheet having a thickness of 240 μm was obtained by imprinting ink into the embossed recess and applying a topcoat layer to the sheet thus obtained in the same manner as in Reference Example 1.

<Comparative example 2>
An embossed sheet obtained by laminating a colored vinyl chloride resin sheet printed with a wood grain pattern using a vinyl chloride-based ink by a gravure method and a transparent vinyl chloride sheet simultaneously with embossing by a doubling embossing method. Got. The embossed sheet thus obtained was imprinted with ink in the embossed concave portions in the same manner as in Reference Example 1 and Comparative Example 1, and further a topcoat layer was applied to obtain a decorative sheet having a thickness of 200 μm.

The emboss depth of the decorative sheet thus obtained was measured with a surface roughness meter, and the emboss reproducibility was evaluated by the ratio (%) between the depth of the emboss plate and the emboss depth of the decorative sheet. Moreover, regarding the comparative example, the initial peel strength, the weather resistance test according to JIS B7753, and the peel strength after 2000 h of sunshine weatherometer were evaluated by the peel strength by 180 degree T-type peel according to JIS Z1707.
Furthermore, the decorative sheet of Comparative Example 2 was used as it was, and the sheets of Reference Example 1 and Comparative Example 1 were coated with a wooden substrate by using a vinyl acetate aqueous emulsion adhesive after applying a urethane primer on the colored substrate side to about 1 μm. Bonding and V-cut processing were performed, bending was performed at 90 ° in an environment of 20 ° C. and 0 ° C., and the degree of whitening of the end portion was observed.

As is clear from Table 1, the embossed decorative sheet of the present invention is a dechlorinated vinyl decorative sheet, and the embossed decorative sheet of the present invention has good reproducibility and is a single-layered sheet having a thickness of about 100 μm. For this reason, there was no problem of peeling of the substrate after the weather resistance test and the heat resistance test, and no whitening occurred even when the V-cut was performed at a low temperature.

  On the other hand, in the conventional vinyl chloride resin decorative sheet as in Comparative Example 2, although a decrease in the adhesion strength after the weather resistance test is not recognized, the embossing reproducibility is inferior, and the V-cut at a low temperature is slightly Whitening was observed. Furthermore, the plasticizer bleeds out over time, so that there is a disadvantage that workability is remarkably lowered.

Moreover, since the method like Comparative Example 1 uses an olefin-based resin, it is a dechlorinated vinyl decorative sheet, and since the resin is melt-extruded, the reproducibility of embossing is excellent. Decrease in adhesion after heat resistance or heat resistance test. Further, since the sheet thickness is thick, whitening is caused by V-cut processing at a low temperature.

As described above in detail, the embossed decorative sheet of the present invention has no environmental problem because it does not use any vinyl chloride resin, and it has excellent emboss reproducibility because it is melt extruded to give emboss. In addition, since the sheet has a single layer configuration, there is no problem of peeling after various durability tests, and since the sheet is thin, whitening does not occur in V-cut processing at a low temperature. Furthermore, since the pattern is substituted with a random pattern in a state where the high-density resin pellets for coloring in the extruded resin are not completely mixed, the process is simplified, and an embossed decorative sheet that is inexpensive in cost can be obtained.

It is sectional drawing of the embossing decorative sheet of the conventional structure. It is sectional drawing of the embossing decorative sheet of the structure of this invention. It is a model diagram which shows an example of the manufacturing method of the embossing decorative sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Colored base material layer which gave pattern 2 Anchor coat layer or adhesive resin layer 3 Transparent resin layer 4 Embossed pattern 5 Colored ink 6 Topcoat protective layer 7 Cooling roll (emboss roll)
8 Pressure roll 9 Peeling roll 10 Extrusion T die

Claims (2)

  Extruding at least molten olefin-based resin between a cooling roll and a pressure roll embossed from a T die to obtain an embossed sheet, applying corona treatment to the surface of the embossed sheet, and imprinting colored ink in the embossed recess In the method for producing an olefin-based resin embossed decorative sheet, further comprising the step of providing a topcoat layer, the embossed sheet is a single-layer embossed sheet having a thickness of 70 to 120 μm, and wood powder, or one or more kinds of the embossed sheet A method for producing an olefin-based resin embossed decorative sheet, which is an embossed sheet having a colored pattern obtained by kneading high-density resin pellets for coloring.   Kneading high-density resin pellets for coloring, in which the colored pattern is wood powder or one or more high-concentration pigments are melt-kneaded and pre-dispersed in a resin that is not completely melt-mixed with the extruded resin. The method for producing an olefin-based resin embossed decorative sheet according to claim 1, wherein the colored high-concentration resin pellets are colored patterns having a random pattern in a state where they are not completely mixed in the extruded resin.

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