JP4897383B2 - Decorative multi-layer coextrusion molding - Google Patents

Description

  The present invention relates to a synthetic resin bent plate having a decorative property that can be used for housing and the like.

  A variety of synthetic resin plate materials having decorative properties such as patterns and luster are used as interior and exterior materials for houses, indoor unit baths, and counter members for kitchens. As a synthetic resin plate material having a decorating property, for example, it is composed of at least three layers of a base material layer made of a thermoplastic synthetic resin, a decorative layer made of a thermoplastic synthetic resin, and a surface layer made of a transparent or translucent synthetic resin. Molded bodies are known. Such a synthetic resin sheet can generally be molded with excellent productivity in a uniform and constant form by a coextrusion molding method. In addition, a molded product having an L-shaped cross section or a rib structure can be continuously produced by profile extrusion. However, while it is easy to mold a product having a constant cross-sectional shape in the extrusion direction, it is extremely difficult to mold a product whose cross-sectional shape fluctuates, and even more difficult to manufacture a deformed product having a curved portion. Met.

As a method of manufacturing a three-dimensional structure product of a synthetic resin plate material, the bending means is one of them, and a three-dimensional structure can be formed from a flat synthetic resin plate material. In order to facilitate folding, cut processing is often performed on the folded portion. Patent Documents 1 to 4 describe the formation of cut grooves for bending.
Japanese Utility Model Publication No. 1-161145 Japanese Patent Laid-Open No. 6-246827 Japanese Utility Model Publication No. 9-32266 JP 2004-160737 A

  However, in the conventional technique, after a flat synthetic resin plate material is manufactured, a cut groove is formed for each bent portion, so that the operation is complicated.

  Therefore, the inventors of the present invention tried to heat-press mold the multilayer coextruded molded product, resulting in a new appearance defect such as unevenness in the pattern due to white turbidity or unevenness, or no depth in the pattern. There was a problem. Such a problem was conspicuous in the bent portion, particularly the bent portion as the apex portion having three surfaces.

  Even if the cross-sectional shape is different in a specific direction, has a curved portion, or is long, the present invention can be easily manufactured at low cost, has a deep pattern uniformly, and is decorated It aims at providing the synthetic resin bending processing board provided with property.

  The present invention includes a base material layer (a) made of a thermoplastic synthetic resin, a patterned decorative layer (b) made of a thermoplastic synthetic resin, and a surface layer (c) having a thickness of 250 to 900 μm made of a transparent or translucent synthetic resin. And a synthetic resin bending plate characterized in that a multilayer coextruded molded body composed of at least three layers is heated and pressed with a mold.

The synthetic resin bending plate of the present invention has a deep pattern without unevenness and has a decorative property.
The synthetic resin bending plate of the present invention is provided with a bent portion by heat-press molding a multilayer coextruded molded body with a mold, so that the cross-sectional shape is different in the extrusion direction, or has a curved portion, Even if it is long, it can be easily manufactured at low cost.

  As shown in FIG. 1, a multilayer coextrusion molded body for forming the synthetic resin bending plate of the present invention (hereinafter sometimes simply referred to as “bending plate”) comprises a base material layer 3 (a), a decorative layer, 2 (b) and the surface layer 1 (c) are at least three layers. Hereinafter, the multilayer coextruded molded body may be simply referred to as a multilayer molded body.

  The base material layer (a) gives a thickness to the bent plate to give a high-class feeling and a heavy feeling when used as an interior / exterior material, to give the bent plate a strength, and to the base structure. Has the role of facilitating installation. In order to maintain workability and light weight even when a considerable thickness is provided, and to prevent warping and deformation in the cooling process during multi-layer molding and heat-press molding, A low-foamed or non-foamed thermoplastic synthetic resin is used for the material layer. The thickness of the multilayer coextruded product is largely determined by the thickness of the base material layer, but the thickness of the base material layer can be varied in a wide range depending on the application, and it is usually designed freely within a range of 3 to 18 mm. Can do.

  The base material layer may be a single color uniform, but when the decorative layer is transparent or translucent, by applying a pattern to the base material layer, it overlaps with the pattern of the decorative layer and has an unprecedented stereoscopic effect. A pattern with deep and complex color composition can be displayed more effectively. The pattern of the base material layer may be a dispersed pattern obtained by mixing powder or a colorant, may be due to the density of the foamed state, or may be due to surface irregularities, or other The pattern by the method may be sufficient.

  The thermoplastic synthetic resin that forms the base layer is polyvinyl chloride resin (hereinafter referred to as PVC resin), acrylonitrile-butadiene-styrene copolymer resin (hereinafter referred to as ABS resin), polystyrene resin (hereinafter referred to as PS resin), High impact polystyrene resin (hereinafter referred to as HIPS resin), acrylonitrile-styrene copolymer resin (hereinafter referred to as AS resin), modified polyphenylene ether resin, polyethylene resin, polypropylene resin, or a mixed resin thereof can be used. Particularly preferred from the viewpoints of moldability, toughness and economy are PVC resin and ABS resin. These thermoplastic synthetic resins are added to fillers such as calcium carbonate, talc, mica and shirasu balloons, lightweight materials, reinforcing materials such as glass fibers and cellulose fibers, flame retardants, and other synthetic resin moldings. Various additives may be included. In particular, when using a resin that is subjected to heat stability such as PVC, it is generally essential to add a heat stabilizer and a lubricant.

  When the base material layer has low foamability, the foaming ratio of the base material layer is 1.1 to 5.0 times, preferably 1.5 to 3.0 times. The expansion ratio is calculated from the true specific gravity of the resin and the specific gravity of the molded product. That is, the value of true specific gravity / molded product specific gravity is taken as the expansion ratio. For example, if the true specific gravity of the ABS resin is 1.1 and the specific gravity of the molded product is 0.55, the expansion ratio is 2.0 times.

The decorative layer (b) is a non-foamed thermoplastic synthetic resin layer having a pattern, and is a layer that can visually arouse aesthetics.
The thermoplastic synthetic resin for forming the decorative layer is not particularly limited as long as it has extrusion moldability. PVC resin; ABS resin; PS resin; HIPS resin; AS resin ;; Acrylonitrile-acrylic rubber- Styrene copolymer resin (hereinafter referred to as “AAS resin”); acrylonitrile-ethylenepropylene rubber-styrene copolymer resin (hereinafter referred to as “AES resin”); polyethylene resin; polypropylene resin; PET resin; PMMA), acrylic resins such as methyl methacrylate-butyl acrylate copolymer and methyl methacrylate-styrene copolymer; nitrile resins or mixed resins thereof can be used.

  In order to achieve the effect of creating a deep pattern by overlapping the pattern of the decoration layer and the pattern of the base material layer through the decoration layer, decoration is performed using a transparent synthetic resin as the base resin of the decoration layer The layer may be transparent or translucent. As such a synthetic resin, a PVC resin, an acrylic resin, a transparent ABS resin, an AS resin, a PET resin, a nitrile resin, or a mixed resin thereof can be used. Particularly preferred resins are acrylic resins, especially PMMA resins.

The following various methods are possible to form a pattern on the decorative layer:
(A) One or more selected from mica powder in synthetic resin; vermiculite powder; metal powder; metal foil powder; organic fiber such as cellulose; wood powder; A method of dispersing the decorative particles of
(B) A method of unevenly dispersing one or more colorants in a synthetic resin,
(C) A method in which unevenness is imparted to the decorative layer with a mold, and the shade is drawn by the difference in resin density, and the like.
Although it does not specifically limit as a pattern formation method of a decoration layer in this invention, The method by which the decorating granular material of (a) is disperse | distributed is preferable. The above methods may be used in combination. In particular, when the method (a) is employed, a stone pattern and a spotted pattern are formed satisfactorily.

  The thickness of the decorative layer is not particularly limited as long as the object of the present invention is achieved, and is usually 0.1 to 2.5 mm. From the viewpoint of more effectively preventing pattern unevenness due to white turbidity or unevenness and obtaining a deeper pattern, the thickness is preferably 300 to 900 μm, more preferably 400 to 800 μm.

From the viewpoint of weather resistance, moldability, and surface decorating properties, the resin for the decorating layer and the resin for the base material layer are preferably used in the following combinations.
(1) Decoration layer resin; PMMA resin-base layer resin; ABS resin;
(2) Decor layer resin; ABS resin-base layer resin; ABS resin;
(3) Decoration layer resin; AES resin-base layer resin; ABS resin;
(4) Decorating layer resin; PMMA resin-substrate layer resin; PVC resin;

In the case where a resin having poor adhesion to the base material layer is used as the decorative layer resin, an adhesive layer may be provided between the base material layer and the decorative layer.
For example, when the resin of the decoration layer is a PMMA resin and the resin of the base material layer is a PS resin, an adhesive layer made of methyl methacrylate-styrene copolymer resin or the like may be provided.

  The surface layer (c) is a transparent or translucent synthetic resin layer. As a result, a deep pattern can be obtained and weather resistance is improved.

As the transparent synthetic resin for forming the surface layer, the same resin as described in the decoration layer can be used, but acrylic resins, ABS, AS, AAS, AES, and PVC are preferable. A more preferable synthetic resin for the surface layer (c) is an acrylic resin, particularly PMMA.
In order to enhance various physical properties, various additives that are usually used in synthetic resins may be added to the surface layer resin.
Moreover, a colorant can also be mix | blended in the range which does not impair transparency.

  The thickness of the surface layer is 250 to 900 μm. If the thickness is too thin, the decorative layer oozes out on the surface of the bent portion at the time of heat and pressure molding, so that the pattern does not appear deep and the pattern is uneven. In particular, when a pattern is formed on the decorative layer by the above method (a), the decorative powder particles are likely to appear on the surface in the bent portion after molding, and therefore pattern unevenness occurs due to irregularities based on the particles. easy. If the thickness is too thick, it is economically disadvantageous for the effect to be unchanged, and the workability at the time of heat and pressure molding is also lowered. The preferred thickness of the surface layer is 300 to 800 μm, in particular 400 to 800 μm. This is because pattern unevenness due to unevenness of the decorative granular material can be more effectively prevented.

From the viewpoint of weather resistance, moldability and surface decorating properties, it is preferable that the resin of the surface layer and the resin of the decorating layer are used in the following combinations.
(1) Surface layer resin; PMMA resin-decorative layer resin; PMMA resin;
(2) Surface layer resin; PMMA resin-decorative layer resin; ABS resin;

  In the case where a resin having poor adhesion to the decorative layer is used as the resin for the surface layer, an adhesive layer may be provided between the decorative layer and the surface layer.

  The thickness of the multilayer molded body is preferably 4 to 20 mm, more preferably 5 to 15 mm. If the thickness of the multilayer molded body is too thin, unevenness in the thickness of each layer in the multilayer molding tends to occur. If it is too thick, it is economically disadvantageous for the effect to be unchanged, and the workability at the time of heat and pressure molding is also lowered.

  In FIG. 1, the decorative layer 2 and the surface layer 1 are sequentially laminated on one side of the base material layer 3, but may be formed on both sides.

  The multilayer molded body is molded by a coextrusion molding method. That is, all the layers are collectively formed by a coextrusion method. From the standpoints of productivity, long product molding, and constant product characteristics, it is most appropriate to perform coextrusion molding by laminating each resin in one die using a coextrusion molding machine as shown in FIG. is there. When the decorative layer or the surface layer is formed by a coating method or the like, peeling occurs at the time of heat and pressure molding between the base material layer and the decorative layer or between the decorative layer and the surface layer, resulting in poor molding. .

  Co-extrusion molding can be performed by a common co-extrusion molding method by appropriately using a co-extrusion molding machine that has been conventionally used for the production of a synthetic resin co-extrusion molding.

  When the base material layer has low foamability, it is necessary to add a foaming agent to the thermoplastic synthetic resin of the base material layer in order to perform low foam extrusion of the base material layer. The foaming agent is preferably a solid foaming agent that decomposes at the extrusion temperature to generate gas, and sodium bicarbonate, ammonium carbonate, azodicarboxylic amide, benzenesulfonyl hydrazide, or the like can be used as such a foaming agent.

  The synthetic resin bending plate of the present invention is obtained by giving a three-dimensional shape by heat-pressing a multilayer coextrusion molded body as described above with a mold. In particular, since it is extremely effective in expressing unevenness of a three-dimensional shape, a vacuum forming method and a pressure forming method using air pressure are often used together with heating and pressurization. Peeling easily occurs. In the present invention, since the multilayer coextrusion molded body effectively prevents delamination, such a molding method is particularly effective.

  Further, the synthetic resin bending plate of the present invention has, for example, a bending portion (arrow) as shown in FIG. 4, and the bending portion is given by heat and pressure molding as shown in FIG. Even if the cross-sectional shape is different in the extrusion direction, has a curved portion, or is long, it can be easily manufactured at low cost. 3A and 3B are schematic views of an XY cross section when the synthetic resin bent plate 10 shown in FIG. 4 is formed. In FIG. 4, “D” indicates, for example, the extrusion direction during coextrusion molding.

  Specifically, as shown in FIG. 3A, the multilayer molded body 20 is first softened by being held between the heated upper and lower molds (21, 22). The multilayer molded body only needs to be softened to such an extent that it can be molded into a predetermined shape by pressing with upper and lower molds. Usually, the surface temperature of the upper and lower surfaces of the molded body is 100 to 150 ° C, preferably 110 to 150 ° C. More preferably, it is heated to 125 to 145 ° C. If the surface temperature of the molded body is too low, the molding is not sufficiently performed, and cracks are generated particularly in the bent portion. If the surface temperature of the molded product is too high, white turbidity occurs and the pattern does not appear deep. In addition, the pattern becomes uneven.

  The front and back (direction) of the multilayer molded body when held between the upper and lower molds is not particularly limited, and a predetermined shape may be imparted to a predetermined surface of the multilayer molded body. For example, when the multilayer molded body has a structure in which the decorative layer 2 and the surface layer 1 are sequentially laminated on one surface of the base material layer 3, the multilayer molded body is held so that the base material layer surface faces the upper mold. Or may be held so as to face the lower mold.

  The material of the upper and lower molds is not particularly limited as long as a predetermined shape can be imparted to the multilayer molded body, and may be, for example, silicon resin, aluminum or the like.

  After sufficiently softening the multilayer molded body, pressure is applied to the multilayer molded body by the upper and lower molds, and the shape of the upper and lower mold molding surfaces is transferred to the multilayer molded body. The pressure at the time of pressurization and the pressurization time are not particularly limited as long as a predetermined shape is imparted to the multilayer molded body.

  When the mold shape is sufficiently transferred to the multilayer molded body, the upper and lower molds are opened and cooled to obtain a synthetic resin bent plate as shown in FIG.

Since the bending plate of the present invention is given a three-dimensional shape by heat and pressure molding, the thicknesses of the base material layer, the decorative layer and the surface layer are generally almost the same as those of the multilayer molded body, or It is thinner than that. In particular, the thickness of the decorative layer and the surface layer of the bent plate is the smallest in the bending portion R (arrow R) as the apex portion having three surfaces as shown in FIG. For example, when the thickness of the layer is within the above range, the thickness of each layer of the bent portion R is usually within the following range.
Decorative layer; 0.08-2.0 mm, especially 0.1-0.6 mm;
Surface layer: 0.1 to 0.8 mm, especially 0.2 to 0.6 mm.

  The three-dimensional shape of the bent plate of the present invention is not particularly limited as long as the object of the present invention is achieved.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” shall mean “parts by weight”.

(Examples 1-3 , Reference Examples 1-2, and Comparative Examples 1-3)
The base layer, the decorative layer, and the surface layer are respectively blended by a co-extrusion molding machine as shown in FIG. 2, the base layer extruder C, the decorative layer extruder B, and the surface layer extruder A. Were simultaneously extruded, laminated in a die, cooled and cut to a predetermined length to form a three-layer multilayer molded body shown in Table 1. The multilayer molded body had a flat plate shape and had dimensions of length 1200 mm × width 400 mm × predetermined thickness. Extrusion conditions are as follows:
Extruder for substrate: 45φ, twin screw extruder (extrusion temperature 180 ° C)
Decorating layer extruder: 40φ, single screw extruder (extrusion temperature 200 ° C)
Extruder for surface layer: 40φ, single screw extruder (extrusion temperature 200 ° C)
The compounds shown in the table were used for the base material layer, the decorative layer, and the surface layer, respectively.

The multilayer molded body was heat-pressed with vacuuming to obtain a synthetic resin bent plate 10 as shown in FIG. 4. Specifically, as shown in FIG. 3 (A), the multilayer molded body 20 was heated. The upper mold 21 (380 ° C.) and the lower mold 22 (380 ° C.) were held. The multilayer molded body 20 was held so that the base material layer faced the upper mold 21. The upper mold 21 was made of silicon resin, and the lower mold 22 was made of aluminum. When the upper surface temperature of the multilayer molded body 20 becomes 130 ° C. and the lower surface temperature becomes 140 ° C., as shown in FIG. 3 (B), the lower die 22 is moved upward and simultaneously the upper die 21 is moved downward, Pressurized for 2 seconds. Then, between the upper mold | type 21-lower mold | type 22 was open | released, it cooled and the synthetic resin bending process board 10 shown in FIG. 4 was obtained.

(Evaluation)
-Unevenness of pattern The surface of the synthetic resin bending board was observed visually.
○: There was no unevenness in the pattern;
Δ: There is no hindrance as a product, but there is some pattern unevenness;
X: Unevenness occurs in the pattern, which hinders the product.

-Depth of pattern The surface of the synthetic resin bending processing board was observed visually.
○: The pattern was deep;
X: The pattern was not deep.

-Thickness The thickness was measured by looking at the cross section of the molded body with a magnifier. In the table, the thickness of the bent plate is the thickness at the bent portion R (arrow R) shown in FIG.

  The synthetic resin bending plate of the present invention is useful as an interior / exterior material for a house, etc., an indoor unit bath, or a counter member for a kitchen.

It is a schematic diagram which shows an example of the cross-sectional structure of the multilayer molded object for manufacture of the synthetic resin bending process board of this invention. It is a schematic diagram which shows an example of the coextrusion molding machine for manufacture of the synthetic resin bending process board of this invention. (A) And (B) is a typical flowchart which shows an example of the heat press molding for manufacture of the synthetic resin bending process board of this invention. It is a typical sketch showing an example of a synthetic resin bending plate of the present invention.

Explanation of symbols

  1: surface layer, 2: decorative layer, 3: substrate layer, A: extruder for surface layer, B: extruder for decorative layer, C: main extruder for substrate layer, 10: synthetic resin bending Plate, 20: multilayer molded product, 21: upper mold, 22: lower mold.

Claims (3)

A base material layer (a) made of a thermoplastic synthetic resin, a patterned decorative layer (b) having a thickness of 300 to 900 μm made of a thermoplastic synthetic resin, and a surface layer having a thickness of 250 to 900 μm made of a transparent or translucent synthetic resin ( a synthetic resin bending plate ing flat multilayer coextrusion molding of 4~20mm thickness of at least three layers is heated pressure molding in a mold of c), the decorative layer in the bent top portion A synthetic resin bending plate in which a bending portion is provided so as to be thinner than the original thickness in the range of thickness of 100 to 600 μm and the thickness of the surface layer of 200 to 600 μm . The synthetic resin bending plate according to claim 1, wherein the decorative layer (b) has a thickness of 400 to 800 µm, and the surface layer (c) has a thickness of 400 to 800 µm. The synthetic resin bending plate according to claim 1 or 2 , wherein the surface layer (c) is made of an acrylic resin.

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